INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan...

70
INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 LEAD-FREE SOLDERS AND ELECTROLESS NICKEL/IMMERSION SILVER (ENImAg) SURFACE FINISH RABIATUL ADAWIYAH BINTI MOHAMED ANUAR UNIVERSITI TUN HUSSEIN ONN MALAYSIA

Transcript of INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan...

Page 1: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 LEAD-FREE

SOLDERS AND ELECTROLESS NICKEL/IMMERSION SILVER (ENImAg)

SURFACE FINISH

RABIATUL ADAWIYAH BINTI MOHAMED ANUAR

UNIVERSITI TUN HUSSEIN ONN MALAYSIA

Page 2: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 LEAD-FREE

SOLDERS AND ELECTROLESS NICKEL/IMMERSION SILVER (ENImAg)

SURFACE FINISH

RABIATUL ADAWIYAH BINTI MOHAMED ANUAR

A thesis submitted in

fulfilment of the requirement for the award of the

Degree of Master of Mechanical Engineering

Faculty of Mechanical and Manufacturing Engineering

Universiti Tun Hussein Onn Malaysia

MAY 2017

Page 3: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

ii

Dedicated to my beloved father and mother who taught me to trust in Allah, love,

encouragement and prays of day and night make me able to get such success.

Page 4: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

iii

ACKNOWLEDGEMENT

In the name of Allah, Most Gracious, Most Merciful Praise is to Allah, the Cherisher

and Sustainer of the World and Master of the day of Judgement. My prayers for my

beloved parents and family who gave countless sacrifice and did every effort in order

to nurture me and provided the highest moral values.

First and foremost I want to thank my advisor Dr. Saliza Azlina Binti Osman.

It has been an honour to be her first Master student. I would like to express my sincere

appreciation for her guidance, support, patience and encouragement throughout my

research. I also appreciate all her contributions of time, ideas, and funding to make my

Master experience more productive. Without her suggestions and criticisms, this thesis

would not be as presented now.

I am also highly appreciate the cooperation and guidance from technicians in

Material and Science Laboratory for providing the technical support needed to

complete this work. Lastly, I would like to thank my lab mates for supporting me to

complete this study and encouragement which have kept me confident and motivated.

Page 5: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

iv

ABSTRACT

The different surface finish and solder size on printed circuit board strongly affect the

formation of intermetallic compounds (IMCs) and solder joint reliability. Among of

various surface finish in the electronic industry, electroless nickel/immersion gold is

the most popular at the moment. However, because their black pad issues, electroless

nickel/immersion silver (ENImAg) was developed as an alternative surface finish.

Therefore, the effect on an interfacial reaction between lead-free solder and ENImAg

surface finish using different solder ball size (Ø300µm, Ø500µm and Ø700µm) was

investigated. All samples were subjected to an aging process with different aging

times. The characterizations of IMC formation were examined by image analyzer,

scanning electron microscopy and energy dispersive x-ray. The results showed that

ENImAg finish was free from the black pad nickel. Subsequently, the solder ball size

has a significant effect on the IMC formation and fracture surface of as-reflowed and

aged solder joint. The IMC thickness of larger solder balls was found to be thicker

(1.74 µm) than smaller solder balls (1.32 µm) during soldering. In contrast to aged

solder joints, the smaller solder ball produced thicker (3.51 µm) IMC compared to

bigger solder balls (2.47 µm). Furthermore, the fracture surface of smaller solder ball

size showed ductile mode for both reflowed and aged solder joints. In addition, the

solder joint on ENImAg surface finish displayed a thinner layer and smaller grain sizes

compared to solder joint on bare copper.

Page 6: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

v

ABSTRAK

Kemasan permukaan dan saiz bebola yang berbeza ke atas papan litar bercetak

memberi kesan terhadap pembentukan sebatian antara logam (IMC) dan

kebolehpercayaan penyambungan pateri. Antara pelbagai kemasan permukaan dalam

industri elektronik, nikel tanpa elektrik/rendaman emas adalah yang paling popular

pada masa ini. Bagaimanapun, disebabkan oleh isu pad hitam, nikel tanpa

elektrik/rendaman perak (ENImAg) dihasilkan sebagai alternatif kemasaan

permukaan. Oleh itu, kesan terhadap tindak balas antara muka di antara pateri bebas

plumbum dan kemasan permukaan ENImAg bersama-sama dengan saiz bebola pateri

yang berbeza iaitu Ø300µm, Ø500µm and Ø700µm telah dijalankan. Semua sampel

melalui proses penuaan dengan masa penuaan yang berbeza. Ciri-ciri pembentukan

IMC telah dianalisis dengan menggunakan penganalisis imej, mikroskop imbasan

electron (SEM) dan tenaga serakan x-ray. Hasil keputusan menunjukkan bahawa,

kemasan ENImAg didapati bebas daripada pad hitam nikel. Seterusnya, saiz bebola

pateri mempunyai kesan yang ketara terhadap pembentukan IMC dan kekuatan ricih

selepas proses pengaliran semula dan penuaan. Bola pateri yang bersaiz besar

mempunyai ketebalan (1.74 µm) IMC yang lebih tebal berbanding bebola pateri

bersaiz kecil (1.32 µm) ketika proses pengaliran semula. Berbeza daripada bebola

pateri yang terdedah pada suhu penuaan, bebola pateri yang lebih kecil menghasilkan

ketebalan (3.51 µm) IMC yang lebih tebal berbanding bebola pateri yg bersaiz besar

(2.47 µm). Tambahan pula, selepas proses pengaliran semula dan penuaan, permukaan

patah untuk bebola pateri yan bersaiz kecil menunjukkan mod mulur. Tambahan lagi,

penyambungan pateri ke atas kemasan permukaan ENImAg menghasilkan IMC yang

nipis, dan saiz bijian yang kecil berbanding penyambungan pateri ke atas tembaga.

Page 7: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

vi

CONTENTS

DECLARATION i

DEDICATION ii

ACKNOWLEDGEMENTS iii

ABSTRACT iv

ABSTRAK v

CONTENTS vi

LIST OF TABLES x

LIST OF FIGURES xii

LIST OF SYMBOLS AND ABBREVIATIONS xxiv

LIST OF APPENDICES xxvi

CHAPTER 1 INTRODUCTION 1

1.1 Introduction 1

1.2 Field of research 2

1.3 Problem statement 3

1.4 Objectives 3

1.5 Scopes of the research 4

1.6 Structure of the thesis 4

CHAPTER 2 LITERATURE REVIEW 5

2.1 Electronic packaging 5

2.1.1 Level of packaging 6

2.2 Interconnection in integrated circuit (IC) 7

2.2.1 Flip chip packaging 8

Page 8: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

vii

2.3 Surface finish metallurgy 10

2.3.1 Hot-air solder levelling (HASL) 12

2.3.2 Organic solderability preservatives (OSP) 13

2.3.3 Electroless nickel/immersion gold (ENIG) 15

2.3.4 Electroless nickel/electroless palladium/

immersion gold (ENEPIG) 20

2.3.5 Immersion silver (ImAg) 23

2.3.6 Immersion tin (ImSn) 26

2.4 Soldering 29

2.4.1 Soldering technique 29

2.4.1.1 Hand soldering 29

2.4.1.2 Wave soldering 30

2.4.1.3 Reflow soldering 32

2.4.2 Lead-free solders 33

2.4.2.1 Tin-silver-copper (SAC) lead-free

Solders 35

2.4.3 Solderability and wettability of solders 39

2.5 Intermetallic compound (IMC) 41

2.5.1 Effect of reflow temperature and time on

interfacial intermetallic compounds (IMCs) 44

2.5.2 Effect of solder size and volume on

intermetallic compounds (IMCs) 46

2.5.3 The kinetic and morphology of IMC growth 48

2.6 Fick’s law 50

2.7 Mechanical reliability testing 54

2.7.1 Effect of solder size on mechanical

properties of solder joint 59

2.8 Summary 61

Page 9: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

viii

CHAPTER 3 RESEARCH METHODOLOGY 62

3.1 Introduction 62

3.2 Sample preparation 64

3.3 Optimizing stable solution 64

3.3.1 Pre-treatment of substrate material 66

3.3.2 Plating equipment preparation 67

3.3.3 Electroless nickel plating 68

3.3.4 Immersion silver 68

3.4 Reflow soldering 69

3.4.1 Flux deposition 69

3.4.2 Solder ball preparation 70

3.4.3 Reflow soldering process 70

3.5 Isothermal aging 71

3.6 Characterization of the intermetallic compounds 72

3.6.1 Characterization of cross-sectional area 73

3.6.2 Characterization of top surface 74

3.7 Single-lap shear testing 75

3.8 Intermetallic compound (IMC) determination 76

3.9 Summary 78

CHAPTER 4 RESULTS AND DISCUSSION 79

4.1 Introduction 79

4.2 Optimization of electroless nickel/immersion

silver solution 80

4.3 Surface morphology of intermetallic compound

after reflow soldering 85

4.3.1 Effect of solder volume on bare copper 87

4.3.2 Effect of solder volume on ENImAg

surface finish 94

Page 10: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

ix

4.4 Surface morphology of intermetallic compound

after isothermal aging 103

4.4.1 Effect of solder volume of SAC305 and

SAC405 on bare copper 104

4.4.2 Effect of solder volume of SAC305 and

SAC405 on ENImAg surface finish 116

4.5 Mechanical testing (single-lap shear test) 130

4.5.1 Single-lap shear test of SAC305 and

SAC405 on bare copper 131

4.5.2 Single-lap shear test of SAC305 and

SAC405 on ENImAg surface finish 140

4.6 Summary 147

CHAPTER 5 CONCLUSION AND RECOMMENDATIONS 148

5.1 Conclusions 148

5.2 Future works and recommendations 149

REFERENCES 150

APPENDIX 170

Page 11: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

x

LIST OF TABLES

2.1 The advantages and disadvantages of flip chip 10

2.2 The example of tin-silver-copper and tin copper

alloys 32

2.3 Selected lead-free binary alloys 35

2.4 Liquidus and reflow temperatures SAC alloy 37

2.5 The range of contact angle (deg) with the

relative wettability 40

2.6 Intermetallic compounds formation (IMC) and

incompatibility between solder and common

substrates 41

3.1 Different types of pre-treatment process 65

3.2 Different types of silver solution with

immersion time 65

3.3 Nickel plating bath solution 68

3.4 Immersion silver plating bath solution 69

3.5 Example of weight percentages calculation 77

3.6 Atomic weight of elements 77

3.7 Weight percentage of predicted IMCs 77

3.7 Continued 78

4.1 EDX spectrum data of (Cu,Ni)6Sn5 98

Page 12: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

xii

LIST OF FIGURES

2.1 Schematic diagram of the electronic packaging

hierarchy 7

2.2 Schematic diagram of first level interconnect

(chip pad to package leads) and their

types of interconnection technologies 8

2.3 Typical flip chip Ball Grid Array (BGA)

package 10

2.4 Comparison market share of surface finishes

between 2003 and 2007 11

2.5 Printed circuit board with lead free HASL

surface finish 12

2.6 Process flow of the hot air solder levelling

(HASL) 13

2.7 Schematic diagram of the hot air solder

levelling (HASL) technique 13

2.8 Printed circuit board with organic solderability

preservatives (OSP) 14

2.9 Process flow of the organic solderablity

preservative (OSP) 15

2.10 Printed circuit board with electroless nickel/

immersion gold (ENIG) 16

Page 13: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

xiii

2.11 Illustration of ENIG formation 16

2.12 Process flow of Electroless Nickel/Immersion

Gold (ENIG) 18

2.13 Bad wetting of plated through hole (PTH) on

printed circuit boards 19

2.14 SEM image black line pad morphology with

mud crack appearance 19

2.15 Schematic diagram of the fracture 20

2.16 SEM image of N-P surface after removing gold

layer (a, b) showing the black pad (black line

nickel) with infirm solder joint performance

and (c, d) negligible corrosion attack in Ni layer

with good solder joint performance 20

2.17 Electroless nickel/electroless palladium/

immersion gold (ENEPIG) standard board 21

2.18 The schematic layer of ENEPIG surface finish 22

2.19 (a) The PdP deposition over nickel and (b)

pure Pd deposition over nickel 23

2.20 Printed circuit board with immersion silver

(ImAg) 24

2.21 Process flow of immersion silver (ImAg) 25

2.22 Cross section SEM images of the Sn-3.5Ag-

0.7Cu: (a) entire solder joint, (b) types

of IMC layer, (c) and (d) top view at the

interface. 26

2.23 Printed circuit board with immersion tin

(ImSn) 27

2.24 Process flow of immersion tin (ImSn) 28

Page 14: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

xiv

2.25 Immersion tin whisker 28

2.26 The wave soldering process 31

2.27 Typical of solder reflow profile 33

2.28 Sn-rich corner of SAC alloys ternary phase

diagram 37

2.29 Sn-Pb phase diagram 38

2.30 Sn-Ag-Cu ternary eutectic reaction 38

2.31 Schematic diagram of the solderable and

protective finishes during the wetting and

spreading of molten solder 40

2.32 Illustration of the interfacial reaction of SAC 305

/Cu. (a) dissolution of the copper substrate,

(b) supersaturation reaction, (c) the formation

of Cu6Sn5, and (d) the formation of Cu3Sn layer

between Cu6Sn5 and Cu substrate 42

2.33 SEM images of Sn-3.9Ag-0.6Cu joint from top

view 43

2.34 SEM image of SAC solder with the copper

substrate (a) cross sectional IMC layers (b) top

surface of IMC layers 44

2.35 The growth mechanism of IMC layer 45

2.36 The illustration of Cu-Sn IMC at several reflow

times: (a) formation of scallop Cu6Sn5, (b)

formation of Cu3Sn between Cu6Sn5 Cu

substrate, and (c) increasing IMC layers with

increasing reflow times 46

2.37 The interface of IMCs thickness with different

sizes of solder balls: (a) 400 µm, (b) 300 µm

Page 15: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

xv

and (c) 200 µm 48

2.38 The position of IMC layer for both (Cu,Ni)6Sn5

and (Ni,Cu)3Sn4 (a) schematic diagram and (b)

the SEM image of Sn-3.5Ag-0.7Cu/Ni interface 49

2.39 Cross section SEM images (a) Sn-3.5Ag and

(b) Sn-4.0Ag-0.5Cu solder joint interface 50

2.40 Illustrated of IMC thickness measurement 53

2.41 The relationship between IMC thickness and

aging time for total IMC 53

2.42 Schematic failure of BGA joint subjected to

shear impact loading 55

2.43 Single-lap joint shear test (a) geometry of the

single-lap solder joint, (b) optical microscope

cross section view and (d) illustration of the

fracture mode. 56

2.44 (a) The cross sectional view of solder joint and

(b) fracture surface after shear test. 57

2.45 Types of failure mode categories. 58

2.46 Loading curve of both Sn3.5Ag0.5Cu and

Sn3.5Ag solder balls after aging for 1, 16,

9 and 1 d with shear speed at 0.1mm/min 60

2.47 The shear strength of as-reflowed and aged

Solder joint with different solder size 60

3.1 Flow chart of research methodology 63

3.2 (a) Plan view and (b) side view of cooper

substrate with their dimension 64

3.3 The process of copper surface pre-treatment 66

3.4 Schematic of electroless plating process 67

Page 16: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

xvi

3.5 No-clean flux 69

3.6 The schematic diagram (a) top surface and (b)

cross section of solder ball formation 70

3.7 Side view of shear testing sample 70

3.8 Carbolite HTF 1800 Furnace model 71

3.9 The temperature profile of reflow soldering 71

3.10 Memmert UN30 32L natural Conventional

drying oven 72

3.11 Sample preparation of cross section

characterization, (a) cutting area of the

sample and, (b) side view of cross section 73

3.12 Image analyser, NIKON ECLIPSE

LV150NL model 74

3.13 Hitachi SEM SU1510 74

3.14 Schematic of top surface method (a) before

etching, and (b) after etching 75

3.15 Fison SEM sputter coater 75

3.16 (a) Universal material testing machine, LR30K

model, and (b) direction of shear testing 76

4.1 XRD result of as-coated Cu/Ni-P layer with

high phosphorous 80

4.2 Cross sectional view of Ni-P with Cu substrate 81

4.3 Top surface and cross sectional view SEM

images of ENImAg surface (a,b) 8 minutes

duration and (c,d) 12 minutes duration

depostions 83

4.4 EDX spectrum of ENImAg finish 8 minutes

deposition of ImAg 83

Page 17: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

xvii

4.5 XRD pattern of ENImAg surface finish for

ImAg deposition (a) 8 minutes (b) 12 minutes

and (c) combination of Cu/Ni-P (as-coated),

8 minutes, 12 minutes. 84

4.6 SEM images of top surface view (a) SAC/

ENImAg surface finish, (b) SAC/Cu and (c)

Schematic diagram for two different location at

the solder ball 86

4.7 (a) Illustration of Cu dissolved into the

molten solder and (b) IMC formation after

reflow at interface 87

4.8 EDX spectrum of Cu6Sn5 IMC formation 88

4.9 SEM images of top surface for SAC305/

Cu with solder size: (a, b) Ø300 µm, (c, d)

Ø500 µm and (e, f) Ø700 µm 89

4.10 SEM images of top surface for SAC405/

Cu with solder size: (a, b) Ø300 µm, (c, d)

Ø500 µm and (e, f) Ø700 µm 90

4.11 Intermetallic thickness of SAC305/Cu

and SAC405/Cu after reflow soldering 91

4.12 Cross-sectional view of SAC305/Cu

solder joint of different solder volume

with solder size: (a, b) Ø300 µm (c, d)

Ø500 µm and (e, f) Ø700 µm 92

4.13 Cross-sectional view of SAC405/Cu

solder joint of different solder volume with

solder size: (a, b) Ø300 µm (c, d) Ø500 µm

and (e, f) Ø700 µm 93

Page 18: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

xviii

4.14 SEM images of top surface for SAC305/

ENImAg with solder size: (a, b) Ø300 µm,

(c, d) Ø500 µm and (e, f) Ø700 µm 96

4.15 SEM images of top surface for SAC405/

ENImAg with solder size: (a, b) Ø300 µm,

(c, d) Ø500 µm and (e, f) Ø700 µm 97

4.16 EDX spectrum of (Cu,Ni)6Sn5 IMC formation 98

4.17 Cross-sectional view of SAC305/ENImAg

solder joint of different solder volume with

solder size: (a, b) Ø300 µm (c, d) Ø500 µm

and (e, f) Ø700 µm 99

4.18 Cross-sectional view of SAC305/ENImAg

solder joint of different solder volume with

solder size: (a, b) Ø300 µm (c, d) Ø500 µm

and (e, f) Ø700 µm 100

4.19 Intermetallic thickness of SAC305/ENImAg

and SAC405/ENImAg after reflow soldering 101

4.20 SEM images of top surface for SAC305/Cu

with solder size Ø300 µm: (a, b) 250 hours

(c, d) 500 hours (e, f) 1000 hours and (g, h)

2000 hours 106

4.21 SEM images of top surface for SAC305/Cu

with solder size Ø700 µm: (a, b) 250 hours

(c, d) 500 hours (e, f) 1000 hours and (g, h)

2000 hours 107

4.22 SEM images of top surface for SAC405/Cu

with solder size Ø300 µm: (a, b) 250 hours

(c, d) 500 hours (e, f) 1000 hours and (g, h)

Page 19: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

xix

2000 hours 108

4.23 SEM images of top surface for SAC405/Cu

with solder size Ø700 µm: (a, b) 250 hours

(c, d) 500 hours (e, f) 1000 hours and (g, h)

2000 hours 109

4.24 Intermetallic thickness versus solder sizes

(a) SAC305/Cu and (b) SAC405/Cu after

isothermal aging 111

4.25 Cross-sectional view for SAC305/Cu with

solder size Ø300 µm: (a, b) 250 hours (c, d)

500 hours (e, f) 1000 hours and (g, h) 2000

hours 112

4.26 Cross-sectional view for SAC305/Cu with

solder size Ø700 µm: (a, b) 250 hours (c, d)

500 hours (e, f) 1000 hours and (g, h) 2000

hours 113

4.27 Cross-sectional view for SAC405/Cu with

solder size Ø300 µm: (a, b) 250 hours (c, d)

500 hours (e, f) 1000 hours and (g, h) 2000

hours 114

4.28 Cross-sectional view for SAC405/Cu with

solder size Ø700 µm: (a, b) 250 hours (c, d)

500 hours (e, f) 1000 hours and (g, h) 2000

hours 115

4.29 Interfacial Cu-Sn IMC growth kinetics on

Cu substrates: (a) SAC305 solder (b) SAC405

solder 116

4.30 SEM images of top surface for SAC305/

Page 20: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

xx

ENImAg with solder size Ø300 µm: (a, b)

250 hours (c, d) 500 hours (e, f) 1000 hours

and (g, h) 2000 hours 119

4.31 SEM images of top surface for SAC305/

ENImAg with solder size Ø700 µm: (a, b)

250 hours (c, d) 500 hours (e, f) 1000 hours

and (g, h) 2000 hours 120

4.32 SEM images of top surface for SAC405/

ENImAg with solder size Ø300 µm: (a, b) 250

hours (c, d) 500 hours (e, f) 1000 hours

and (g, h) 2000 hours 121

4.33 SEM images of top surface for SAC305/

ENImAg with solder size Ø700 µm: (a, b)

250 hours (c, d) 500 hours (e, f) 1000 hours

and (g, h) 2000 hours 122

4.34 Cross-sectional images of SAC/ENImAg

surface finish (a) before etching by using

optical microscope and (b) after etching

by using SEM 123

4.35 Interfacial Cu-Sn-Ni IMC on Cu/ENImAg

substrates: (a) SAC305 and (b) SAC405 124

4.36 Cross-sectional view for SAC305/ENImAg

with solder size Ø300 µm: (a, b) 250 hours

(c, d) 500 hours (e, f) 1000 hours and (g, h)

2000 hours 125

4.37 Cross-sectional view for SAC305/ENImAg

with solder size Ø700 µm: (a, b) 250 hours

(c, d) 500 hours (e, f) 1000 hours and (g, h)

Page 21: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

xxi

2000 hours 126

4.38 Cross-sectional view for SAC405/ENImAg

with solder size Ø300 µm: (a, b) 250 hours

(c, d) 500 hours (e, f) 1000 hours and (g, h)

2000 hours 127

4.39 Cross-sectional view for SAC405/ENImAg

with solder size Ø700 µm: (a, b) 250 hours

(c, d) 500 hours (e, f) 1000 hours and (g, h)

2000 hours 128

4.40 Interfacial Cu-Sn IMC growth kinetics on

ENImAg substrates: (a) SAC305 solder (b)

SAC405 solder 130

4.41 Typical fracture surface after single-lap

shear test 132

4.42 SEM images of fractures surface for

SAC305/Cu after reflow with solder size:

(a, b) Ø300 µm, (c, d) Ø500 µm and (e, f)

Ø700 µm 133

4.43 SEM images of fractures surface for

SAC405/Cu after reflow with solder size:

(a, b) Ø300 µm, (c, d) Ø500 µm and (e, f)

Ø700 µm 134

4.44 SEM images of fractures surface for SAC305/

Cu with solder size Ø300 µm: (a, b) 250 hours

(c, d) 500 hours (e, f) 1000 hours and (g, h)

2000 hours 136

4.45 SEM images of fractures surface for SAC305/

Cu with solder size Ø700 µm: (a, b) 250 hours

Page 22: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

xxii

(c, d) 500 hours (e, f) 1000 hours and (g, h)

2000 hours 137

4.46 SEM images of fractures surface for SAC405/

Cu with solder size Ø300 µm: (a, b) 250 hours

(c, d) 500 hours (e, f) 1000 hours and (g, h)

2000 hours 138

4.47 SEM images of fractures surface for SAC405/

Cu with solder size Ø700 µm: (a, b) 250 hours

(c, d) 500 hours (e, f) 1000 hours and (g, h)

2000 hours 139

4.48 SEM images of fractures surface for

SAC305/ENImAg after reflow with solder

size: (a, b) Ø300 µm, (c, d) Ø500 µm and

(e, f) Ø700 µm 141

4.49 SEM images of fractures surface for

SAC405/ENImAg after reflow with solder

size: (a, b) Ø300 µm, (c, d) Ø500 µm and

(e, f) Ø700 µm 142

4.50 SEM images of fractures surface for

SAC305/ENImAg with solder size Ø300

µm: (a, b) 250 hours (c, d) 500 hours (e, f)

1000 hours and (g, h) 2000 hours 143

4.51 SEM images of fractures surface for SAC305/

ENImAg with solder size Ø700 µm: (a, b)

250 hours (c, d) 500 hours (e, f) 1000 hours

and (g, h) 2000 hours 144

4.52 SEM images of fractures surface for SAC405/

ENImAg with solder size Ø300 µm: (a, b)

Page 23: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

xxiii

250 hours (c, d) 500 hours (e, f) 1000 hours

and (g, h) 2000 hours 145

4.53 SEM images of fractures surface for SAC405/

ENImAg with solder size Ø700 µm: (a, b)

250 hours (c, d) 500 hours (e, f) 1000 hours

and (g, h) 2000 hours 146

Page 24: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

xxiv

LIST OF SYMBOLS AND ABBREVIATIONS

Ag - Silver

Au - Gold

Cu - Copper

In - Indium

Ni - Nickel

P - Phosphorous

Pb - Lead

Pd - Palladium

Sb - Antimony

Sn - Tin

Zn - Zinc

BGA - Ball Grid Array

CPU - Central Processing Unit

DCA - Direct Chip Attach

DIP - Dual in Line Package

ECA - Electrical Circuit Assembly

EDX - Energy Dispersive X-Ray

ENEPIG - Electroless Nickel/Electroless Palladium/Immersion Gold

ENIG - Electroless Nickel/Immersion Gold

ENiImAg - Electroless Nickel/Immersion Silver

FC - Flip Chip

FESEM - Field Emission Scanning Electron Microscope

Page 25: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

xxv

HASL - Hot-Air Solder Levelling

I/O - Input/Output

IC - Integrated Circuit

ImAg - Immersion Silver

IMC - Intermetallic Compound

ImSn - Immersion Tin

JEDEC - Joint Electron Device Engineering Council

JEIDA - Japan Electronic Industries Development Association

MCM - Multi Chip Module

NEMI - National Electronic Manufacturing Initiative

OM - Optical Microscope

OSP - Organic Solderability Preservative (OSP)

PBB - Poly-Brominated Biphenyls

PBDE - Poly-Brominated Diphenyl Ethers

PCB - Printed Circuit Board

PTH - Plated Through Hole

PWB - Printed Wire Bond

RoHS - Restriction of Hazardous Substance

SAC - Tin-Silver-Cooper

SEM - Scanning Electron Microscope

SMD - Surface Mount Device

SMT - Surface Mount Technology

TAB - Tape Automated Bonding

TCM - Thermal Conduction Module

WEEE - Waste from Electrical and Electronic Equipment

XRD - X-ray Diffraction

Page 26: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

xxvi

LIST OF APPENDICES

APPENDIX TITLE PAGE

A SEM Images of Top Surface for SAC/Cu 170

B Cross-Sectional View for SAC/Cu 172

C SEM Images of Top Surface for SAC/

ENImAg 174

D Cross-Sectional View for SAC/ENImAg 176

E SEM Images of Fracture Surface for SAC/Cu 178

F SEM Images of Fracture Surface for SAC/

ENImAg 180

G EDX Spectrum of IMC Formation 182

H Graph of Single – Lap Shear Test 183

I Proceeding and Journal Paper 185

Page 27: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

1

CHAPTER 1

INTRODUCTION

1.1 Introduction

In the current industrial world, electronic devices have connectivity with an electronic

system, which is electro-mechanical structure called packaging. The electronic

packaging concept has been used for more than one century in wide variety of

technologies. This package is very important because without it, there would be no

electronic devices produced these days. Electronic packaging technology is now

widely used in the semiconductor industry. There is a rapid increase in the number of

electronic packages using flip chip technology because their performance such as flip

chip packages does not need peripheral space for the wire bonding with high frequency

characteristics. It can also increase the number of input/output capacity and the power

of connections in a smaller area. Today, electronic engineers are using the package to

protect electronic devices and their interconnections.

The increasing miniaturization of electronic component has challenged the

researchers to investigate solder materials to meet the requirements of solder

interconnects and obtain good joints between component and substrates. Driven by

the current trend of smaller and thinner electronic products, the solder joint

interconnection should become smaller as well. The smaller of solder joint

interconnection may influences the interfacial reactions and mechanical properties

such as intermetallic (IMC) thickness layer, morphology and solder joint strength. The

presence of IMC layer is necessary for bonding between solder balls and substrates

however, the thickness of IMC layer can affect the solder joint strength at interface.

Page 28: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

2

1.2 Field of research

Nowadays, many users are using products based on electronic components. With the

continuous development of the mobile phones, radios, televisions, computers and

laptops, digital camcorders, digital cameras, and other electronic equipment based

product has caused the flip chip packaging to operate in full action. Flip chip bonding

technology was offers excellent performance with a shorter connection between the

chip and the printed circuit board. In addition, the rating of input and output data is at

the highest level and has smaller size than other methods.

Solder reflow flip chip uses the solder ball as to connect between the chip and

substrate. The printed circuit board will react with Sn in the solder ball to form

intermetallic compound (IMC) layer during soldering process. The formation of IMC

layer is desirable for necessary bonding because it is needed for the formation of solder

joint. Furthermore, the brittleness of IMC layer makes it susceptible to mechanical

failure even at low loads. Besides, the thickness of IMC layer can change the physical

properties of material across the joint. It is because, the thicker IMC layer can cause

the reliability problem of the solder joint. However, the selection of the substrate

surface finish plays an important role to determine the characteristic of IMC formation.

The substrate such as copper will oxidized and deteriorate if their surface unprotected.

Therefore, coating deposition can act as a barrier and provide a solderable surface in

the process of soldering the component to the printed circuit board (PCB).

Many studies have been conducted on the joint reliability and interfacial

reaction between Pb-free solders and various surface finish layers such as Cu,

Au/Ni/Cu and electroless nickel-immersion gold (ENIG), during reflow and aging

process. Generally, the most popular lead-free surface finishes used in electronic

industries are electroless nickel/immersion gold (ENIG) and ENEPIG (electroless Pd

added), immersion silver (ImAg), immersion tin (ImSn) and organic solderability

preservative (OSP). Therefore, the reliability of solder joint must have solderable

surface to form good solder connection between solder balls and substrates.

Page 29: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

3

1.3 Problem statement

Since July 2006, the legislative of Restriction of Hazardous Substance (RoHS) was

banned the use of tin-lead (Sn-Pb) and shift to lead-free solder due to human health

and environmental problem. Lead usage is dangerous since it can cause lead poisoning

when it enters the body through inhalation and feeding contact such as direct contact

to mouth and skin contact to nose, eyes and skin lesions. Sn-Ag-Cu (SAC) is one of

the lead-free solder family that can offer better alternative to the electronic industries

due to reliability, good solderability and mechanical properties.

The demands of surface finish have become essential for printed circuit board

when the industries were shifted to lead-free compliance. Electroless nickel/

immersion gold (ENIG) has been predominant in the industries since ENIG is designed

as an excellent solderable surface and highly corrosion resistant. However, ENIG

surface finish possess its own weakness such as high cost of gold metal and black pad

issues. The black pad can occur due to the immersion gold plating bath during

assembly process, can also lead to bad wetting area and even brittle solder joints. This

issue has been a concern in electronic industry as it affects the reputation of ENIG

which known excellent surface finish. Thus, it is proposed that electroless nickel-

immersion silver (ENImAg) will be its alternative that can replace ENIG to overcome

the stated problem. Therefore, interfacial reaction between SAC305 and SAC405 lead-

free solders and electroless nickel-immersion (ENImAg) surface finish need to be

investigated.

1.4 Objectives

The main objectives in this research are as follows:

i) To examine the effect of ENImAg surface finish on interfacial reaction

(intermetallics) formed at interface during soldering and isothermal aging.

ii) To evaluate the effects of solder ball volume (ball size) on interfacial

reactions in terms of thickness, type and morphology.

iii) To observed the solder joint reliability in term of fracture mode between

surface finish and lead-free solders.

Page 30: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

4

1.5 Scopes of the research

The scopes of this study consists of the following tasks:

i) Deposition of ENImAg surface finish on copper substrates using electroless

and immersion plating process. As comparison, bare copper will be used.

ii) Formation of solder joints between two lead-free solder alloys; Sn-3.0Ag-

0.5Cu (SAC305) and Sn-4.0Ag-0.5Cu (SAC405) in three different sizes of

solder ball which are Ø300, Ø500 and Ø700 µm.

iii) Conduct isothermal aging at 150C for different aging duration (250, 500, 1000

and 2000 hours).

iv) Conduct mechanical test through shear testing.

v) Characterization of IMC formed during reflow and isothermal aging using

Optical Microscope (OM), Scanning Electron Microscope (SEM) and/or Field

Emission Scanning Electron Microscope (FESEM), Energy Dispersive X-ray

EDX and X-ray Diffraction (XRD).

1.6 Structure of the Thesis

This thesis consists of five chapters. Chapter one is an introduction that contains field

of research, problem statement, objectives and scopes of the research. Chapter two

presents the basic of electronic packaging, interconnection in integrated circuit (IC),

surface finish, soldering techniques, intermetallic compound formation, Fick’s law and

mechanical reliability. Chapter three describes the experimental procedures and

soldering techniques as well as materials characterization preparation. Chapter four

contains the results and discussion obtained from experimental work. Lastly, in chapter

five, the conclusion and recommendation are presented based on the research work.

Page 31: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

5

CHAPTER 2

LITERATURE REVIEW

2.1 Electronic packaging

Generally, electronic devices have a connection to an electronic system with

electromechanical structure called ‘packaging’. The concept of electronic devices has

been used for more than a century and electronic component would not exist without

packaging. Packaging is a major area of interest within the field of electronic

packaging technology. Electronic packaging is a housing and interconnection of

integrated circuits (IC) to design electronic systems (Szendiuch, 2011). The function

of electronic packaging is to protect electronic devices from the environment. At the

same time, it also acts as powering, cooling and chip packaging (Rasmussen et al.,

2003 & Martens, 2013).

Integrated circuit has been an object of research since the 1950s (Pecht, 1991).

IC packaging is the central connection of the process that produces these systems. It

must be communicated with other IC chips in a circuit through an input/output (I/O)

system of interconnects (Lau et al., 1998 & Cheng et al., 2011). This package will

provide circuit support and protection, power distribution, heat dissipation, signal

distribution, manufacturability and serviceability (Wong & McBride, 1994 &

Tummala et al., 1997). Besides that, with the performance of electronic devices,

electronic components are now designed in smaller sizes (Shnawah et al., 2012) and

the number of inputs/outputs has been increasing with the advance made in chip

integration (Pecht, 1991; Cheng et al., 2011; Tong, 2011). The increasing numbers of

chip integration production also increase production of heat flux, where it is dissipated

from the chip surface area (Pecht, 1991). In the future, electronic packaging will force

the researchers to design most powerful and advanced technologies of electronics.

Page 32: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

6

2.1.1 Level of packaging

Electronic system can be divided into a simple hierarchy that consists of packaging,

printed circuit boards (PCBs) and systems. These systems have several levels starting

with nil until fourth level as shown in Figure 2.1. Level zero has a thin circular wafer

(chip) that consists of logic gates, transistors, and gate to gate interconnections. The

first packages level is a chip carrier protection, where it can range from single-chip

module to multi-chip module. Some examples can be seen in the chip barrier such as

dual in line package (DIP) and thermal conduction module (TCM) for both single-chip

and multi-chip, respectively. Electrical circuit assembly (ECA) can be referred as the

second level of packaging. Currently, this stage consists of printed wiring board

(PWB) or printed circuit board (PCB). For both first level and second level, solder is

usually used to joint packages to PCB (Xu et al., 2015). Whereas, third level packages

is the interconnection of circuit boards and power supplies to system or physical

interface. The protective structure such as cabinet is also related with this level. On the

other hand, ECA interconnection and large PCB are referred as backplane. When

backplane, and cable joined together, it is known as a as a single cabinet. Lastly, when

a few cabinets are merged together, fourth level will be created (Pecht, 1991; Lau et

al., 1998; Harper, 2005). Interconnection between cabling systems such as central

processing unit (CPU) is also called fourth level of packaging (Lau et al., 1998;

Harper, 2005; Tong, 2011). Nowadays, circuit and requirement system of high

performance, high reliability and low cost have caused greater demands for the

packaging engineer to have excellent understanding of the existing packaging

technologies.

Page 33: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

7

Figure 2.1: Schematic diagram of the electronic packaging hierarchy (Lau et al.,

1998).

2.2 Interconnection in integrated circuit (IC)

Electronic packaging is the method by which an integrated circuit is packaged in a

modular form so that it can be used in the end product such as a cell phone, a laptop

computer or even a smoke detector (Harper, 2005). Packaging technologies is now

being developed to another standard of chip performance. For example, the Multi Chip

Module (MCM) has substantial advantages over the old PWB interconnect approaches

(Neugebauer, 1990). The chip to package assembly has three different

interconnections such as wire bond (WB), tape automated bonding (TAB) and flip chip

(FC) (Tummala, 2001) as shown in Figure 2.2. Today, flip chip technology is widely

used in electronic packaging because it offers better performance of high speed system,

self-alignment during die joining, productivity enhancement over manual wire

bonding and low lead inductance (Ramesham, 2014).

Page 34: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

8

Figure 2.2: Schematic diagram of first level interconnect (chip pad to package leads)

and their types of interconnection technologies (Tummala, 2001).

2.2.1 Flip chip packaging

In electronic packaging, wafer scale integration, assembly of discrete packages on

printed wiring boards, multi-chip module, and higher packaging levels are the material

requirements for the next generation of electronic packaging strategies. It is also

related with the performance and cost of the future electronic system. Besides, this

type of future will be strongly depending on the right choice of the packaging approach

(Neugebauer, 1990). Now, electronic packaging is replacing the older technology,

from wire bonding to flip chip interconnection. Flip chip interconnect technology is

the direct electrical connection to approaches, where the silicon die or chip is

connected face down to the substrates, circuit boards or carriers, by means of

conductive bumps on the chip bond pads. According to Lau (1994) & Lau et al. (1998),

flip chip also known as Controlled Collapse Chip Connection or Direct Chip Attach

(DCA).

Flip chip packaging is considered as the first level interconnect technology

because the greatest input/output flexibility can be achieved by it. Besides that, it also

offers the best performance with shorter connections between chips and circuit boards

(Lau et al., 1998). Using the wire bonding connections is limited to the parameter of

Page 35: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

9

the die. Hence, the connection can be used the whole area of the die by using flip chip.

Additionally, these connections have advantages since they are using solder bump. In

connection to the drop of chip voltages and increasing current requirements, flip chip

has the ability to reduce voltage drop by distributing the power and grounding directly

to the device’s core with area array solder bumps (Elenius & Lee, 2000). Other

advantages of flip chip are better performance and reliability, cost over other

packaging methods as well as its widening availability of flip chip materials,

equipment and services (Riley, 1997 & Ramesham, 2014).

Figure 2.3 displays the schematic of a flip chip component. Solder bump is

applied to the integrated circuit (IC) to provide interconnection for the flip chip and to

activate circuitry on the IC toward the substrate. For the first step processing, the flip

chip assembly forms all interconnections between IC and the substrate. Then underfill

or knowns as polymer material is applied between the IC and substrate to enhance

package reliability, integrity and reliability of the assembly when subjected to

mechanical shock or bending test (Nah et al., 2011). Solder interconnects can produce

the electrical and mechanical connection between chip bond and the carrier bond pad.

This technique is known as flip chip bonding technique. In the meantime, in order to

ensure a reliability interconnect structure, the bump must consist of solder with various

types of surface metallization. For reflow soldering, flip chip interconnects can be

made simultaneously for all components in a single high speed process (Chen et al.,

2010). Table 2.1 presents the summary of advantages and disadvantages of flip chip

package (Elenius & Levine, 2000 & Ramesham, 2014).

Page 36: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

10

Figure 2.3: Typical flip chip Ball Grid Array (BGA) package (Baldwin, 2005).

Table 2.1: The advantages and disadvantages of flip chip (Pascariu et al., 2003)

Advantages

Disadvantages

1. Reduces signal inductance

2. The contact pads are distributed over the

entire chip surface from confined to the

periphery.

3. Afford to connect all the input/output in one

single step.

4. Enhanced heat dissipated because of

possibility of attachment of heat sink to

backside of chip.

5. Higher signal density

1. Thermal expansion often does not match

between the semiconductor chips and the

substrate.

2. Possible to increase in thermal resistance.

3. Lower design change flexibility

4. Higher production process cost

2.3 Surface finish metallurgy

The consideration of surface finish on the PCB is perhaps the most essential selection

material decision made for the electronic assembly. Surface finish heavily influences

the cost, manufacturability, quality and reliability of the final product (Milad, 2008 &

Pun et al., 2014). The function of surface finish is to protect the exposed copper

circuitry and provide a solderable surface in assembling (soldering) the components to

Page 37: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

11

the PCB (Milad et al., 2007 & Pun et al., 2014). However, surface finish as the final

finish is designed to protect copper from oxidation and also acts as barrier layer to

minimize growth of the IMC layer. Moreover, there are great expectations for the

surface finish to meet the criteria such as solderability, contact performance, wire

bondability and corrosion resistance which have to be achieved at lower cost (Milad

et al., 2007).

Nowadays, many surface finishes are now sharing the market and each has a

characteristic that make it interesting for certain applications. The selection of a

surface finish will rely on balancing different factors including performance, reliability

and cost. Figure 2.4 shows the comparison market share of surface finish between 2003

and 2007 (Schueller, 2005). The vital aspect and characteristic of each surface finishes

will be discussed and the figure will resembled which product that suits the

characteristics of the finish and which of them not critical to the product application.

Figure 2.4: Comparison market share of surface finishes between 2003 and 2007

(Schueller, 2005).

OSP,

18%

Immersion

Tin, 2%

Immersion

Silver, 2%

HASL +

Electrolytic,

70%

ENIG,

8%

Surface Finishes Market (2003)

OSP,

34%

Immersion

Tin, 17%

Immersion

Silver, 17%

HASL + Electrolytic,

18%

ENIG,

14%

Surface Finishes Market (2007)

Page 38: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

12

2.3.1 Hot-air solder levelling (HASL)

Hot-Air Solder Levelling (HASL) is an under srutiny because of environmental and

safety issues such as hazardous waste or lead expose, technology limitation (fine-pitch

devices assembly), and equipment maintenance expenses to name a few (Parquet,

1995). HASL is widely used in North America, Europe and most of Asian countries

except Japan during tin lead era (Sweatman, 2009). Since the early 1980s, this method

was widely used for professional printed circuit board. Figure 2.5 shows the printed

circuit board with lead free HASL surface finish. According to Choon (2003), the PCB

is immersed from its edge, in a pot of molten solder, withdrawn, and then excess solder

is blown off using strong blast of hot air. This process is known as solder levelling.

Figure 2.5: Printed circuit board with lead free HASL surface finish (Wright, 2015).

The flow process of HASL consists of a pre-clean cycle, preheating, flux

coating, solder coating, levelling with hot air knives, cooling, and a post-clean section

as shown in Figure 2.6. Meanwhile, Figure 2.7 shows a schematic diagram of the

HASL process (Sweatman, 2009). Besides that, HASL gives the entire protection to

copper surface of a panel and products such as solder mask over bare copper

(SMOBC). It also has an excellent shelf life, shorter solder wetting times at assembly,

high mechanical durability, and formation of intermetallic bond before the printed

Page 39: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

13

wiring board assembly process. However, HASL is also popular to be known as roll

tinning where a very thin layer of solder will be transferred to the panel from hot tinned

rolls (Fellman, 2005).

Figure 2.6: Process flow of the hot air solder levelling (HASL) (Fellman, 2005).

Figure 2.7: Schematic diagram of the hot air solder levelling (HASL) technique

(Sweatman, 2009).

2.3.2 Organic solderability preservatives (OSP)

Organic Solderability Preservatives (OSP) are getting famous as an alternative to hot

air solder levelling (HASL) surface finish as shown in Figure 2.8. One of the

disadvantage of HASL process is, it allows the Cu-Sn intermetallic growth where this

process causes the thermal shock to degrade the printed circuit boards (PCBs)

completely. Besides that, HASL also causes brittle solder joints and poor solderability.

Page 40: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

14

Therefore, the use of OSP surface finish can helps to eliminates thermal shock and Cu-

Sn intermetallic compound, and increase the solder joint reliability. The other

advantages of OSP are low cost, excellent in surface co-planarity of the coated pad

and excellent for fine pitch surface mount technology due to their thin thickness and

even coating (Li, 1997).

OSPs are normally azola based organic films. Azola is necessary in order to

identify their volatility, decomposition temperature, existence of an organometallic

polymer between the azola and a metal other than copper (Paw et al., 2008). There are

several types of azola including benzotriazole, imidazoles, and benzimidazoles.

However, benzimidazole is a one base of OSP that can cut the cost to 70% compare

with HASL (Li, 1997). This type has a low temperature at 75˚C, the thickness of layer

less than 10nm, can prevent copper tarnish and to allow one or two thermal reflow

cycles (Tong et al., 2006).

Figure 2.8: Printed circuit board with Organic Solderability Preservatives (OSP)

(Wright, 2015).

The substrate of the OSP is copper-clad using the subtractive method where

the bare copper is coated with an organic sealant to prevent oxidation and exposure to

the air. The thin layer of surface finish enables tight control in the z-axis and prevents

opens due to co-planarity tolerances (Zarrow & Kopp, 1996). Generally, OSP surface

finish is considered as a low cost option due to its simpler flow process compared to

Page 41: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

15

HASL. It consists of four steps starting with cleaner, micro-etch, pre-dip and flood of

OSP as shown in Figure 2.9.

Figure 2.9: Process flow of the organic solderablity preservative (OSP) (Wright,

2015).

2.3.3 Electroless nickel/immersion gold (ENIG)

Electroless Nickel/Immersion Immersion Gold (ENIG) was introduced in the late

1990s as final surface finish in the electronic industry as shown in Figure 2.10. ENIG

is being recognised within the industry because it meets the needs for lead-free

assembly. Other than that, it also offers coplanar surface for both solderable, excellent

electrical contacting surface and aluminium wire bondable (Johal & Lamprecht, 2008

& Milad, 2008). ENIG is formed from the deposition of electroless - phosphorous on

a catalysed copper surface, followed by a thin layer of immersion gold as shown in

Figure 2.11 (Milad, 2008). Besides that, ENIG is designed to provide a highly

corrosion resistant and excellent solderable surface (Long & Toscano, 2013). The

other advantages of ENIG surface finish are longer shelf life, flat soldering surface for

Surface Mount Technology (SMT) (Li, 2015) and its suitability for hot bar soldering

and anisotropic conductive film (ACF) bonding (Johal & Lamprecht, 2008).

Page 42: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

16

Figure 2.10: Printed circuit board with electroless nickel/immersion gold (ENIG)

(Wright, 2015).

Figure 2.11: Illustration of ENIG formation (Slocum, 2006).

The ENIG deposition process is quite complex. A clean copper surface from

solder mask residual that is also copper/tin intermetallic free is needed. Next, nickel

layer is plated over copper, followed by gold plating over the nickel layer. Immersion

gold entails nickel element to supply electrons that will be deposited on it. They also

can lessen hydride generation and galvanic reactions (Milad, 2013). Electroless nickel

process is an autocatalytic reduction process, where the aqueous metal ions are coated

to a copper without path of external current (Sudagar et al., 2013 & Sapkal et al.,

2015). The surface remains in contact with the electroless nickel solution as long as

the reaction continued in this process.

Page 43: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

17

Basically, the apparent element of the bath solution is nickel sulphate as the

main source of nickel and sodium hypophosphite. While the source for both electrons

that works for the deposition of the nickel and phosphorus is the reducing agent

(Agarwala & Agarwala, 2003; Sudagar et al., 2013; Sapkal et al., 2015). Other

elements of common crucial solution include complexing agent, stabilizers, chelating

agents, and buffering agent (Schlesinger, 2011 & Milad, 2013). These solutions can

maintain the stability of nickel solution and are responsible for the consistency of

thickness layer. The important parameters during plating are the temperature and pH

value to maintain a rate of deposition in particular life of the bath (Malecki & Ilnicka,

2000 & Mallory, 2009).

Electroless has several advantages on the electroplating which include the

quality of deposit such as physical and mechanical properties. Some of the properties

are practicable on electroless such as solderability, high hardness, magnetic properties,

amorphous, microcrystalline deposit, resistivity and low coefficient of friction.

However, most applications of the auto-catalytic are depending on their wear and

corrosion resistance (Agarwala & Agarwala, 2003). The desired properties can be vary

by choosing the different temperature, pH value, and composition of the bath (Sudagar

et al., 2013).

Nickel layer is used to protect the copper from liquidation, perpetuate the

reliability of the finish process, and protect them from cracking during test (Milad,

2013). Currently, nickel is co-deposited with phosphorous. For the circuit application,

the common range of medium phosphorous used is 7 to 9 percent by weight. The

content of phosphorous in electroless nickel can influence the behavior of the physical,

mechanical and corrosion resistance properties of the coating. The amount of Ni-P can

determine the microstructure of the coating either crystalline, amorphous, or both

combination of the microstructure (Martyak, 1994). Currently, low and medium

phosphorus level in electroless nickel process has a mixture of amorphous and

microcrystalline nickel, while, the structure is fully amorphous when the phosphorus

content is high (Guo et al., 2003; Keong et al., 2003; Sudagar et al., 2013). Based on

Page 44: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

18

high Ni-P content, these coating have better corrosion resistant, very ductile, low

porosity, low internal intrinsic stress and non-magnetic is as plated state as mentioned

by Mallory (2009). Besides that, some fabricators concern about the low thickness of

nickel layer because it is important to prevent nickel cracking. However, it can be seen

that thin layer can cause black pad defect, whereas, thicker layer can prevent the black

pad problem (Johal & Lamprecht, 2008). There are six steps of ENIG process which

consist of clean/micro-etch, catalyst, electroless nickel, rinse, immersion gold and

rinse/clean as shown in Figure 2.12.

By comparing with other surface finish such as Organic Solderability

Preservative (OSP) and Hot Air Solderability Levelling (HASL), ENIG is more

expensive because the price of gold metal is higher compare to OSP and HASL.

Besides, another problem which is ‘black pad’ (Lin et al., 2007) may lead to bad

wetting including non-wetting and de-wetting also brittle solder joint as shown in

Figure 2.13 (Bin & Yabing, 2012). Black pad defect is caused by nickel layer oxidation

during immersion gold process, where it is formed between nickel and gold layer (Lin

et al., 2007) as shown in Figure 2.14. The researcher found typical black pad

morphology of nickel layer with ‘mud crack’ appearance on the surface solder joint

with the bad wetting area and the nickel layer of bare PCB path (Li, 2015).

Figure 2.12: Process flow of electroless nickel/immersion gold (ENIG) (Johal &

Lamprecht, 2008).

Page 45: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

19

Figure 2.13: Bad wetting of plated through hole (PTH) on printed circuit boards (Li,

2015).

Figure 2.14: SEM image black line pad morphology with mud crack appearance (Li,

2015).

During the assembly process, a thin intermetallic with Sn atom was formed

when Ni atom diffused into liquid Sn matrix. The phosphorous (P) did not take part in

this reaction. P has great element concentration known as P-rich layer. The symptoms

of black pad with solder joint often fractured at P-rich layer, which have brittleness

property and poor wetting issues. The fracture may appear at interface between P-rich

layer and Ni-Sn intermetallic layer (Yang et al., 2010). Many researchers had

investigated the brittle failure mode and found a formation of Ni/Sn intermetallic

compounds known as crystallographic species (Ni3Sn4). Besides, between Ni/Sn

intermetallic and Ni-P layer, there are thin P-rich layer and Kirkendall void (Lee &

Lee, 2006). Figure 2.15 shows the fracture location. Meanwhile, Figure 2.16 shows

the SEM image of Ni-P surface after gold layer was removed.

Page 46: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

20

Figure 2.15: Schematic diagram of the fracture (Yang et al., 2010).

Figure 2.16: SEM images of N-P surface after removing gold layer (a, b) showing

the black pad (black line nickel) with infirm solder joint performance and (c, d)

negligible corrosion attack in Ni layer with good solder joint performance (Lee &

Lee, 2006).

2.3.4 Electroless nickel/electroless palladium/immersion gold (ENEPIG)

Electroless Nickel/Immersion Gold (ENIG) is popular in electronic industry.

Nonetheless, due to its of disadvantages such as weak wire bonding performance and

solder joint problems from black pack issues, ENEPIG is offered as an alternative to

ENIG surface finish as shown in Figure 2.17. ENEPIG with high solder joint quality,

Page 47: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

21

better performance and wire bondability was introduced in electronic industry (Ramos

et al., 2011). It is expected to be inexpensive as the gold layer of lower thickness can

be used (Pun et al., 2014). Using palladium (Pd) in ENEPIG surface finish, it can be

developed to overcome weak wire bonding and solder joint problems (Fu et al., 2008).

Pd layer between Ni and Au was introduced to be a barrier layer to prevent Ni atom

liquidation during Au layer deposition (Hsiao, 2007).

Figure 2.17: Electroless nickel/electroless palladium/immersion gold (ENEPIG)

standard board (Chaillot et al., 2013).

In addition, Pd layer was found to limit the corrosion of the nickel due to

aggressive immersion gold process. It also allows both aluminium wire bonding and

gold operation (Kao & Roberts, 2010; Ramos et al., 2011). In this surface finish, the

function of Pd layer acts as a protection layer, where it can prevent from black pad

problems, improve wire bonding ability and enlarge process window of bonding wire.

Besides that, nickel performs as diffusion barrier layer to prevents inter-diffusion

between copper and solder ball (Yoon, 2009). This way, it can prevent the gold layer

from underneath layer oxidation and wetting ability when soldering (Fu et al., 2008).

The thickness requirements of Ni/Pd/Au layer are Ni layer (3-6 µm), Pd layer (0.05-

0.30 µm) and Au layer (>0.030 µm), respectively. These thickness requirements do

not accord to the assembly process of either tin lead or SAC. However, some of the

reseachers suggested to reduce the thickness of Pd layer to 0.05 µm even if it is for

Page 48: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

22

SnPb assembly process, with gold layer that also needs to be increased up to 0.15 µm

(Chaillot et al., 2013). Figure 2.18 shows the metallic layers of ENEPIG surface finish.

According to Pun et al. (2014), they was mentioned that the increasing of both

Au layer and Pd layer does not improve solder joint reliability and wire bondability.

Therefore, it is important to balance the Au and Pd thickness to optimize the reliability

of both wire bonding and soldering. Besides the increasing Pd thickness (above 0.3

µm), this part will also result in significant reduction of shear strength with fracture

mainly occurring at the Pd-Ni-Sn, and Cu-Ni-Sn intermetallic interface. ENEPIG

surface finish has two types of Pd layer either using palladium phosphorous alloy

(PdP), or as pure palladium. These types of layers are related to the hardness of PdP

and pure Pd deposits, because the increasing of phosphorous content will increase the

hardness of Pd deposits. Based on Figure 2.19, it can be seen that there is a smooth

topography of electroless palladium in the individual grains, while pure Pd is showing

a form of nano-roughness. Thus, the larger grains describe the known structure of the

underlying nickel layer (Kao & Roberts, 2010).

Figure 2.18: The schematic layer of ENEPIG surface finish (Slocum, 2006).

Page 49: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

23

Figure 2.19: (a) The PdP deposition over nickel and (b) pure Pd deposition over

nickel (Kao & Roberts, 2010).

2.3.5 Immersion silver (ImAg)

Immersion silver (ImAg) (Figure 2.20) has emerged as an alternative to HASL and

ENIG because of its good solderability and aluminium wire bonding performance

(Arra et al., 2004). It also has excellent silver solderability which maintained through

the multiple reflow cycle and suitable for fine pitch electronic component (Barbetta,

2004 & Wang et al., 2009). ImAg finish can prevent the black pad problem, whisker

formation, tin copper shell-life reduction and sensitivity to weak fluxes. The other

benefits of the ImAg include inspectability at assembly, flatness, surface contact

functionality and solder mask attack reduction (Cullen & O’Brien, 2004). Besides,

immersion silver is lower in cost because of the simpler operation and it eliminates the

possibility of producing the embrittling Au-Sn intermetallic compound (Yoon & Jung,

2008).

The immersion plating is a process where the chemical displacement reaction

will be deposited into the bare copper. During the reaction, the base metal donates the

electrons that can reduce the positive charge metal ions present in the solution. During

the reaction, once the metal is plated, there is no source of electrons and the reaction

will automatically stop. Therefore, this reaction is considered as a self-timing process

(Schlesinger, 2010). As an immersion process, it has a simple process and better result

in stress testing and thermal shock (Fang & Chan, 2007). Besides, immersion process

(a) (b)

Page 50: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

24

needs shorter time compared with electroless plating. Choosing immersion silver as a

layer, plays a role as protective finish that ensures the solderability of the underlying

copper. The molten solder needs to be moistened and disseminated over the silver

surface finish, then the ImAg layer will dissolve into the molten solder. This situation

is similar with HASL and OSP, where it allows the formation of copper-tin

intermetallic solder joint (Wang et al., 2009).

Figure 2.20: Printed circuit board with immersion silver (ImAg) (Wright, 2015).

Immersion silver deposits layer is 100 times thinner than traditional

electroplated silver deposits. The range of ImAg thickness is 0.15 – 0.55 µm, which is

coated with nearly pure silver. Usually, in this process a slight amount of organic

material will be used to prevent tarnish, electro-migration and allow for extended shelf

life (Cullen & O’Brien, 2004). These organic materials can co-deposit with silver

solution and known as ‘organo - silver’ deposits. The purity of silver takes only 70 to

80 percent, and the rest 20 to 30 percent is organic addition agent or organic carbon

(Fang & Chan, 2007). Wang et al. (2009) found that in order to get the 0.5 µm Ag

layer in range (Zheng, et al., 2002), the duration of plating time has to be around 1

minute to 4 minutes. The researcher reported that the thickness of immersion silver

must not be too thick due to brittle solder joint in lead-free soldering, and not too thin

to ensure a shelf life of this surface finish during storage (Yoon & Jung, 2008).

Like an OSP finish process, ImAg has a short and simple process. The process

consists of cleaning the exposed copper, micro-etching, pre-dipping, immersion silver

Page 51: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

150

REFERENCES

Agarwala, R. C., & Agarwala, V. (2003). Electroless alloy/composite coatings : A

review. Sadhana, 28(3-4), 475–493.

Aisha, S. R., Ourdjini, A., Wah, N.M., How, H.C., & Chin, Y. T. (2010). Interfacial

Reactions of SAC305 and SAC405 Solders on Electroless Ni(P)/ Immersion Au

and Electroless Ni(B)/Immersion Au Finishes. Proc. of the 34th Int. Conf. on

Electronic Manufacturing Technology. Melaka, Malaysia: IEEE. pp. 2–7.

Akhtar, A. M. Z., Wirda, K. H., Rabiatull, I. S., & Mahadzir, I. (2014). Microstructure

Evolution at the Solder Joint during Isothermal Aging. In Proc. of the 36th Int.

Conf. on Electronic Manufacturing Technology.Johor, Malaysia: IEEE. pp. 1–5.

Aleksinas, M. J. (1990). Chapter 3 Troubleshooting Electroless Nickel Plating

Solutions. Mallory, G.O & Hajdu, J.B. Electroless Plating - Fundmentals and

Applications. United State of America: William Adrew. pp. 101–109.

Anderson, I. E., Cook, B. a, Harringa, J., Terpstra, R. L., Foley, J. C., & Unal, O.

(2002). Effects of Alloying in Near-Eutectic Tin – Silver – Copper Solder Joints.

Material Transaction, 43(8), 1827–1832.

Arra, M., Shangguan, D., Xie, D., Sundelin, J., Lepistö, T., & Ristolainen, E. (2004).

Study of Immersion Silver and Tin Printed-Circuit-Board Surface Finishes in

Lead-Free Solder Applications. Journal of Electronic Materials, 33(9), 977–990.

Aziz, M. S. A., Abdullah, M. Z., Khor, C. Y., & Ani, F. C. (2013). Influence of pin

offset in PCB through-hole during wave soldering process : CFD modeling

approach. International Communications in Heat and Mass Transfer, 48, 116–

123.

Azlina, O. S., Ourdjini, A., & Aisha, I. S. R. (2012). Effect of Nickel Doping on

Interfacial Reaction between Lead-Free Solder and Ni-P Substrate. Advanced

Materials Research, 488–489, 1375–1379.

Azmah Hanim, M. A., Ourdjini, A., Saliza Azlina, O., & Aisha, S. R. (2013).

Intermetallic Evolution for Isothermal Aging Up To 2000 Hours On Sn-4Ag-

Page 52: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

151

0.5Cu and Sn-37Pb Solders With Ni/U Layers. International Journal of

Automotive and Mechanical Engineering (IJAME), 8(0), 1348–1356.

Azmah Hanim, M. A., Ourdjini, A., Siti Rabiatul Aisha, I., & Saliza Azlina, O. (2013).

Effect of Isothermal Aging 2000 Hours on Intermetallics Formed between Ni-Pd-

Au with Sn-4Ag-0.5Cu Solders. Advanced Materials Research, 650, 194–199.

Baheti, V. A., Islam, S., Kumar, P., Ravi, R., Hongqun, D., Vuorinen, V., Laurila, T.

& Paul, A. (2015). Effect of Ni content on the diffusion-controlled growth of the

product phases in the Cu(Ni) – Sn system. Philisophical magazine, 96(1), 15-30.

Baldwin, D.F. (2005). Chip Scale, Flip Chip, and Advanced Chip Packaging

Technologies. Electronic Packaging and Interconnection Handbook, Fourth

Edition. New York: McGraw-Hill.

Bang, W. H., Kim, C. U., Kang, S. H., & Oh, K. H. (2009). Fracture mechanics of

solder bumps during ball shear testing: Effect of bump size. Journal of Electronic

Materials, 38(1), 1896–1905.

Barbetta, M. (2004). The search for the universal surface finish. Printed Circuit Design

and Manufacture, 21(2), 34–43.

Baskaran, I., Narayanan, T. S. N. S., & Stephen, A. (2006). Effect of accelerators and

stabilizers on the formation and characteristics of electroless Ni–P deposits.

Materials Chemistry and Physics, 99(1), 117–126.

Bernasko, P. K., Mallik, S., & Takyi, G. (2015). Effect of intermetallic compound

layer thickness on the shear strength of 1206 chip resistor solder joint. Soldering

& Surface Mount Technology, 27(1), 52–58.

Bin, Y., & Yabing, Z. (2012). Key Failure Modes of Solder Joints on ENIG PCBs and

Root Cause Analysis. Proc. of the 13th Int. Conf. on Electronic Packaging

Technology & High Density Packaging (ICEPT-HDP).Guangxi, China: IEEE.

pp. 1205–1208.

Callister, W.D. (2003). Materials Science and Engineering an Introduction. 6th

Edition. New York: John Wiley & Sons.

Page 53: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

152

Cannon, M., Klenke, B., & Zarrow, P. (2006). Improving Hand Soldering Operational

Costs and Process Control. Circuits Assembly, 17(7), 1–4.

Chaillot, A., Venet, N., Hokka, J., Defense, A., Space, T. A., & Defense, A. (2013).

Enepig Finish : An Alternative Solution for Space Printed Circuit. Proc. of the

Conf. Microelectronics Packaging (EMPC). Eurpoean: IEEE. pp. 1–6.

Chan, Y. C., So, A. C. K., & Lai, J. K. L. (1998). Growth kinetic studies of Cu–Sn

intermetallic compound and its effect on shear strength of LCCC SMT solder

joints. Materials Science and Engineering: B, 55(1–2), 5–13.

Chan, Y. C., & Yang, D. (2010). Failure mechanisms of solder interconnects under

current stressing in advanced electronic packages. Progress in Materials Science,

55(5), 428–475.

Chang, K. C., & Chiang, K. N. (2004). Aging study on interfacial microstructure and

solder-ball shear strength of a wafer-level chip-size package with Au/Ni

metallization on a Cu pad. Journal of Electronic Materials, 33(11), 1373–1380.

Chen, C., Tong, H. M., & Tu, K. N. (2010). Electromigration and Thermomigration in

Pb-Free Flip-Chip Solder Joints. Annual Review of Materials Research, 40(1),

531–555.

Chen, Y. H., Wang, Y. Y., & Wan, C. C. (2007). Microstructural characteristics of

immersion tin coatings on copper circuitries in circuit boards. Surface and

Coatings Technology, 202(3), 417–424.

Cheng, R., Jiang, K., & Li, X. (2011). Enhanced solder joint bonding strength of

electronic packaging with electrowetting effect. Microelectronic Engineering,

88(11), 3244–3248.

Choi, W. K., Kang, S. K., & Shih, D. Y. (2002). A study of the effects of solder volume

on the interfacial reactions in solder joints using the differential scanning

calorimetry technique. Journal of Electronic Materials, 31(11), 1283–1291.

Chung, C. K., & Tai, S. F. (2004). Evolution of Ag3Sn During Reflow Soldering.

Thermal and Thermomechanical Phenomena in Electronic Systems,2(0), 116–

120.

Page 54: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

153

Cioci, R., Pecht, M., & Ganesan, S. (2006). Lead-Free Electronics: Overview. Lead

Free Electronic. New Jersey: John Wiley & Sons, Inc.

Cullen, D. P., & O’Brien, G. (2004). Implementation of immersion silver PCB surface

finish in compliance with Underwriters Laboratories. Proc. of the IPC Printed

Circuits Expo. SMEMA Council APEX. pp. 1–10.

Dele-Afolabi, T. T., Azmah Hanim, M. a., Norkhairunnisa, M., Yusoff, H. M., &

Suraya, M. T. (2015). Investigating the effect of isothermal aging on the

morphology and shear strength of Sn-5Sb solder reinforced with carbon

nanotubes. Journal of Alloys and Compounds, 649, 368–374.

El-Daly, A. A., & Hammad, A. E. (2010). Elastic properties and thermal behavior of

Sn-Zn based lead-free solder alloys. Journal of Alloys and Compounds, 505(2),

793–800.

Elenius, P., & Levine, L. (2000). Comparing Flip-Chip and Wire-Bond

Interconnection Technologies. Chip Scale Review, 6(6), 81–87.

Ervina Efzan, M. N., & Marini Aisyah, A. (2012). A review of solder evolution in

electronic application. International Journal of Engineering, 1(1), 2305–8269.

Ervina Efzan, M. N., Nur Faziera, M. N., & Siti Rabiatull Aisha, I. (2016). Soldering

& Surface Mount Technology A Review : An Evolution of Lead-Free Solder and

Its Wettability Properties. Soldering & Surface Mount Technology, 28(3), 125–

132.

Fellman, J. (2005). A study of the lead‐free hot air solder levelling process. Circuit

World, 31(2), 3–9.

Frear, D. R. (2007). Issues related to the implementation of Pb-free electronic solders

in consumer electronics. Lead-Free Electronic Solders: Journal of Materials

Science: Materials in Electronics, 319–330.

Fu, C., Hung, L., Jiang, D., Chang, C., Wang, Y. P., & Hsiao, C. S. (2008). Evaluation

of New Substrate Surface Finish : Electroless Nickel / Electroless Palladium /

Immersion Gold (ENEPIG). Proc. of the 58th Conf. on Electronic Components

and Technology. Lake Buena Vista, Florida: IEEE. pp. 1931–1935.

Page 55: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

154

Fukuda, Y., Ganesan, S. & Pecht, M. (2006). Lead-Free Legislation, Exemptions, and

Compliance. Lead-Free Electronics. New Jersey: John Wiley & Sons, Inc.

Goosey, M. (2005). Soldering considerations for lead‐free printed circuit board

assembly – an Envirowise Guide. Circuit World, 31(3), 40–44.

Guo, B., Kunwar, A., Ma, H., Liu, J., Li, S., Sun, J., Zou, N. & Ma, H. (2015). Effects

of soldering temperature and cooling rate on the as-soldered microstructures of

intermetallic compounds in Sn-0.7Cu/Cu joint. Proc. of the 16th Int. Conf. on

Electronic Packaging Technology (ICEPT). Central South University, China:

IEEE. pp. 249–252.

Guo, Z., Keong, K. G., & Sha, W. (2003). Crystallisation and phase transformation

behaviour of electroless nickel phosphorus platings during continuous heating.

Journal of Alloys and Compounds, 358(1–2), 112–119.

Guofeng, X., Fei, Q., Tong, A., & Wei, L. (2011). Diffusion-induced stresses in the

intermetallic compound layer of solder joints. Proc. of the 12th Inter. Conf. on

Electronic Packaging Technology and High Density Packaging (ICEPT-HDP).

Shanghai, China: IEEE. pp. 1–5.

Ha, S.-S., Park, J., & Jung, S.-B. (2011). Effect of Pd Addition in ENIG Surface Finish

on Drop Reliability of Sn-Ag-Cu Solder Joint. Materials Transactions, 52(8),

1553–1559.

Hai, H. T., Ahn, J. G., Kim, D. J., Lee, J. R., Chung, H. S., & Kim, C. O. (2006).

Developing process for coating copper particles with silver by electroless plating

method. Surface & Coatings Technology, 201(6), 3788–3792.

Harper, C.A. (2005). Electronic Packaging and Interconnection Handbook, Fourth

Edition. New York: McGraw-Hill.

Ho, C. E., Lin, Y. W., Yang, S. C., Kao, C. R., & Jiang, D. S. (2006). Effects of limited

cu supply on soldering reactions between SnAgCu and Ni. Journal of Electronic

Materials, 35(5), 1017–1024.

Ho, C. E., Yang, S. C., & Kao, C. R. (2007). Interfacial reaction issues for lead-free

electronic solders. Journal of Materials Science: Materials in Electronics, 18(1-

Page 56: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

155

3), 155–174.

Hsiao, C. S. (2007). Investigation of IMC growth and solder joint reliability on new

surface finish-ENEPIG. 2007 International Microsystems, Packaging, Assembly

and Circuits Technology, (123), 331–334.

Hu, J., Hu, A., Li, M., & Mao, D. (2010). Depressing effect of 0.1 wt.% Cr addition

into Sn-9Zn solder alloy on the intermetallic growth with Cu substrate during

isothermal aging. Materials Characterization, 61(3), 355–361.

Hu, X., Xu, T., Jiang, X., Li, Y., Liu, Y., & Min, Z. (2016). Effects of post-reflow

cooling rate and thermal aging on growth behavior of interfacial intermetallic

compound between SAC305 solder and Cu substrate. Applied Physics A:

Materials Science and Processing, 122(4), 1–10.

Hua, X., Li, Y., & Min, Z. (2014). Interfacial reaction and IMC growth between Bi-

containing Sn0.7Cu solders and Cu substrate during soldering and aging. Journal

of Alloys and Compounds, 582, 341–347.

Huang, T. S., Tseng, H. W., Lu, C. T., Hsiao, Y. H., Chuang, Y. C., & Liu, C. Y.

(2010). Growth Mechanism of a Ternary (Cu,Ni)6Sn5 Compound at the

Sn(Cu)/Ni(P) Interface. Journal of Electronic Materials, 39(11), 2382–2386.

Huang, X., Lee, S.W. R., Yan, C. C., & Hui, S. (2001). Characterization and analysis

on the solder ball shear testing conditions. Proc. of the 51st Conf. on Electronic

Components and Technology. Orlando, Florida: IEEE. pp. 12–15.

Illes, B., & Horvath, B. (2013). Whiskering behaviour of immersion tin surface

coating. Microelectronics Reliability, 53, 755–760.

Johal, K., Roberts, H., Lamprecht, S., & Wunderlinch, C. (2005). Electroless Nickel /

Immersion Gold Process Technology for Improved Ductility of Flex and Rigid-

Flex Applications. Americas, 25(30), 1–7.

Kao, B., & Roberts, H. (2010). Pure Palladium in ENEPIG Surface Finishes – Physical

properties of the Pd deposition and their influence on soldering and wire bonding.

Proc. of the Conf. on Microsystems, Packaging, Assembly and Circuits

Technology (IMPACT). Nangang, China: IEEE. pp. 1–4.

Page 57: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

156

Kar, A., Ghosh, M., Ray, A. K., & Ghosh, R. N. (2007). Effect of copper addition on

the microstructure and mechanical properties of lead free solder alloy. Materials

Science and Engineering A, 459(1–2), 69–74.

Keller, J., Baither, D., Wilke, U., & Schmitz, G. (2011). Mechanical properties of Pb-

free SnAg solder joints. Acta Materialia, 59(7), 2731–2741.

Keong, K. G., Sha, W., & Malinov, S. (2003). Computer modelling of the non-

isothermal crystallization kinetics of electroless nickel-phosphorus deposits.

Journal of Non-Crystalline Solids, 324(3), 230–241.

Kiat Choon, T. (2003). The effect of the hot air levelling process on skip solder defects

in the wave soldering process. Soldering & Surface Mount Technology, 15(2),

28–34.

Kim, J. W., & Jung, S. B. (2004). Experimental and finite element analysis of the shear

speed effects on the Sn-Ag and Sn-Ag-Cu BGA solder joints. Materials Science

and Engineering A, 371(1–2), 267–276.

Kim, J. W., & Jung, S. B. (2006). Reexamination of the solder ball shear test for

evaluation of the mechanical joint strength. International Journal of Solids and

Structures, 43(7–8), 1928–1945.

Kim, K. S., Huh, S. H., & Suganuma, K. (2003). Effects of intermetallic compounds

on properties of Sn-Ag-Cu lead-free soldered joints. Journal of Alloys and

Compounds, 352(1–2), 226–236.

Kivilahti, J. K. (2002). The Chemical Modeling of Electronic Materials and

Interconnections. Jom, 54(12), 52–57.

Kotadia, H. R., Howes, P. D., & Mannan, S. H. (2014). A review: On the development

of low melting temperature Pb-free solders. Microelectronics Reliability, 54(6–

7), 1253–1273.

Lau, J. H. (1994). Chip on Board. Technology for Multichip Modules.New York:

Springer Science & Business Media.

Lau, R., Wong, C.P., Prince, J.L., & Nakayama, W. (1998). Electronic Packaging

Design, Materials, Process, and Reliability. New York: McGraw-Hill

Page 58: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

157

Laurila, T., & Vuorinen, V. (2009). Combined thermodynamic-kinetic analysis of the

interfacial reactions between Ni metallization and various lead-free solders.

Materials, 2(4), 1796–1834.

Laurila, T., Vuorinen, V., & Kivilahti, J. K. (2005). Interfacial reactions between lead-

free solders and common base materials. Materials Science and Engineering R:

Reports, 49(1–2), 1–60.

Lee, D. J., & Lee, H. S. (2006). Major factors to the solder joint strength of ENIG layer

in FC BGA package. Microelectronics Reliability, 46(7), 1119–1127.

Lee, H. T., Chen, M. H., Jao, H. M., & Liao, T. L. (2003). Influence of interfacial

intermetallic compound on fracture behavior of solder joints. Materials Science

and Engineering: A, 358(1–2), 134–141.

Lee, K. Y., Li, M., Olsen, D. R., Chen, W. T., Tan, B. T. C., & Mhaisalkar, S. (2001).

Microstructure, joint strength and failure mechanism of Sn-Ag, Sn-Ag-Cu versus

Sn-Pb-Ag solders in BGA packages. IEEE Transactions on Electronics

Packaging Manufacturing, 25(3), 185–192.

Lee, L. M., & Mohamad, A. A. (2013). Interfacial reaction of Sn-Ag-Cu lead-free

solder alloy on Cu: A review. Advances in Materials Science and Engineering,

2013, 1–11.

Lee, L. M., Nazeri, M. F. M., Haliman, H., & Mohamad, A. A. (2014). Corrosion of

Sn-3.0Ag-0.5Cu thin films on Cu substrates in alkaline solution. Soldering &

Surface Mount Technology, 26(2), 79–86.

Lee, N. (2006). Optimizing the reflow profile via defect mechanism analysis.

Soldering & Surface Mount Technology, 11(1), 13–20.

Lee, Y. H., & Lee, H. T. (2007). Shear strength and interfacial microstructure of Sn-

Ag-xNi/Cu single shear lap solder joints. Materials Science and Engineering A,

444(1–2), 75–83.

Li, G. Y., & Chen, B. L. (2003). Formation and Growth Kinetics of Interfacial

Intermetallics in Pb-Free Solder Joint. IEEE Transactions on Components and

Packaging Technologies, 26(3), 651–658.

Page 59: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

158

Li, M., Xu, H., Kim, J., & Kim, H. (2007). Failure modes of lead free solder bumps

formed by induction spontaneous heating reflow. Journal of Materials Science &

Technology, 23(1), 61–67.

Li, W. (2015). Failure Analysis on Bad Wetting of ENIG Surface Finish Pads. Proc.

of the 16th Int. Conf. on Electronic Packaging Technology (ICEPT). Changsa,

China: IEEE. pp. 538–541.

Li, Y., & Corporation, E. (1997). An experimental study on organic solderability

preservative. Proc. of the 21th Int. Conf. on Electronics Manufacturing

Technology (IEMT) Symposium. Austin, USA: IEEE. pp. 56–61.

Li Fang, J., & Chan, D. K. (2007). The advantages of mildly alkaline immersion silver

as a final finish for solderability. Circuit World, 33(2), 43–51.

Lim, H. P., Ourdjini, A., Bakar, T. A. A., & Tesfamichael, T. (2015). The Effects of

Humidity on Tin Whisker Growth by Immersion Tin Plating and Tin Solder

Dipping Surface Finishes. Procedia Manufacturing: Proc. of the 2nd Int. Conf. on

Materials, Industrial, and Manufacturing Engineering (MIME). Bali, Indonesia:

Elsevier. pp. 275–279.

Lin, K.L., & Shih, C.L. (2003). Wetting interaction between Sn-Zn-Ag solders and

Cu. Journal of Electronic Materials, 32(2), 95–100.

Lin, K., & Hsu, K. (2000). Manufacturing and Materials Properties of

Ti/Cu/Electroless Ni/Solder Bump on Si. IEEE Transactions on Components,

Packaging, and Manufacturing Technology, 23(4), 657–660.

Lin, Y. C., Shih, T. Y., Tien, S. K., & Duh, J. G. (2007). Morphological and

microstructural evolution of phosphorous-rich layer in SnAgCu/Ni-P UBM

solder joint. Journal of Electronic Materials, 36(11), 1469–1475.

Liu, P., Yao, P., & Liu, J. (2009). Effects of multiple reflows on interfacial reaction

and shear strength of SnAgCu and SnPb solder joints with different PCB surface

finishes. Journal of Alloys and Compounds, 470(1–2), 188–194.

Liu, X., Huang, M., Zhao, Y., Wu, C. M. L., & Wang, L. (2010). The adsorption of

Ag3Sn nano-particles on Cu-Sn intermetallic compounds of Sn-3Ag-0.5Cu/Cu

Page 60: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

159

during soldering. Journal of Alloys and Compounds, 492(1–2), 433–438.

Liukkonen, M., Havia, E., Leinonen, H., & Hiltunen, Y. (2009). Application of self-

organizing maps in analysis of wave soldering process. Expert Systems with

Applications, 36(3), 4604–4609.

Long, E., & Toscano, L. (2013). Electroless Nickel/Immersion Silver- A New Surface

Finish PCB Applications. Metal Finishing, 111(1), 12–19.

Loomans, M. E., & Fine, M. E. (2000). Tin-silver-copper eutectic temperature and

composition. Metallurgical and Materials Transactions A, 31(4), 1155–1162.

Ma, H., & Suhling, J. C. (2009). A review of mechanical properties of lead-free solders

for electronic packaging. Journal of Materials Science, 44(5), 1141–1158.

Ma, H. T., Wang, J., Qu, L., Zhao, N., & Kunwar, A. (2013). A study on the physical

properties and interfacial reactions with Cu substrate of rapidly solidified Sn-

3.5Ag lead-free solder. Journal of Electronic Materials, 42(8), 2686–2695.

Małecki, A., & Micek-Ilnicka, A. (2000). Electroless nickel plating from acid bath.

Surface and Coatings Technology.123(1), 72-77

Mallory, G. O. (2009). The Electroless Nickel Plating Bath: Effect of Variables on the

Process. in Mallory, G. O., & Hajdu, J. B (1990). Electroless Plating,

Fundamentals & Applications, 69; 71; 72. Reprint Edition. United State of

America: William Adrew. 57-99.

Manish, R. (2013). Surface Engineering for Enhanced Performance against wear.

Heidelberg, germany: Springer. pp.79-110.

Marshall, J. H. (1983). The Nickel Metal Catalyzed Decomposition of Aqueous

Hypophosphite Solutions. Electrochemical Society, 130(2), 369–372.

Martyak, N. M. (1994). Characterization of Thin Electroless Nickel Coatings.

Chemistry of Materials, 6(11), 1667–1674.

Mayappan, R., Yahya, I., Ghani, N. A. A., & Hamid, H. A. (2014). The effect of adding

Zn into the Sn-Ag-Cu solder on the intermetallic growth rate. Journal of

Materials Science: Materials in Electronics, 25(7), 2913–2922.

Mhd Noor, E. E., Mhd Nasir, N. F., & Idris, S. R. A. (2016). A review: lead free solder

Page 61: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

160

and its wettability properties. Soldering & Surface Mount Technology, 28(3),

125–132.

Mieczkowski, D. (2009). Reflow Soldering Guidelines for Surface-Mount Hybrid

Microelectronic Devices and Lumped Element Filter Assemblies Introduction

Reflow Process Overview Selection of Solder Paste Selection of Solder Stencil

Development of Solder Reflow Profile Initial Pre-H. API Technologies

Philadelphia Operation, 1–4.

Milad, B. G., & Orduz, M. (2007). Surface Finishes in a Lead-Free World. Metal

Finishing, 105(1), 25–28.

Milad, G. (2008). Surface finishes in a lead-free world. Circuit World, 34(4), 4-7.

Milad, G., & Milad, G. (2013). Is “ black pad ” still an issue for ENIG ? Circuit World,

36(1), 10–23.

Mookam, N., & Kanlayasiri, K. (2011). Effect of soldering condition on formation of

intermetallic phases developed between Sn–0.3Ag–0.7Cu low-silver lead-free

solder and Cu substrate. Journal of Alloys and Compounds, 509(21), 6276–6279.

Moon, K.-W., & Boettinger, W. J. (2004). Accurately determining eutectic

compositions: The Si-Ag-Cu ternary eutectic. Jom, 56(4), 22–27.

Mukherjee, M., & Chakravorti, S. (2014). Assessment of Moisture Diffusion Distance

in Pressboard Insulation Within Transformer using Fick ’ s Law. Proc. of the 18th

Conf. on National Power System (NPSC). Institute of Technology Guwahati,

India: IEEE. pp. 4–7.

Nah, J. W., Gaynes, M. A., Feger, C., Katsurayama, S., & Suzuki, H. (2011).

Development of wafer level underfill materials and assembly processes for fine

pitch Pb-free solder flip chip packaging. Proc. of the 61st Conf. on Electronic

Components and Technology(ECTC). Florida, USA: IEEE. pp. 1015–1022.

Nai, S. M. L., Wei, J., & Gupta, M. (2009). Interfacial intermetallic growth and shear

strength of lead-free composite solder joints. Journal of Alloys and Compounds,

473(1–2), 100–106.

Neugebauer C.A. (1990). Electronic Packaging and Interconnection Technology :

Page 62: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

161

State of the art and future developments. IEEE Circuits and Systems, 3, 2081–

2084.

Noor, E. E. M., Sharif, N. M., Yew, C. K., Ariga, T., Ismail, A. B., & Hussain, Z.

(2010). Wettability and strength of In-Bi-Sn lead-free solder alloy on copper

substrate. Journal of Alloys and Compounds, 507(1), 290–296.

Ourdjini, A., Azmah Hanim, M. A., Siti Rabiatull Aisha, I., & Chin, Y. T. (2008).

Effect of surface finish metallurgy on intermetallic compounds during soldering

with tin-silver-copper solders. Proc. of the 33rd Int. Conf. Electronics

Manufacturing Technology (IEMT) Symposium. Penang: IEEE. pp. 2–5.

Ourdjini, A., Hanim, M. A. A., Koh, S. F. J., Aisha, I. S., Tan, K. S., & Chin, Y. T.

(2006). Effect of Solder Volume on Interfacial Reaction between Eutectic Sn-Pb

and Sn-Ag-Cu Solders and Ni(P)-Au Surface Finish. International Electronic

Manufacturing Technology, 437–442.

Park, Y. S., Kwon, Y. M., Moon, J. T., Lee, Y. W., Lee, J. H., & Paik, K. W. (2010).

Effects of fine size lead-free solder ball on the interfacial reactions and joint

reliability. Proc. of the 60th Conf. on Electronic Components and Technology

(ECTC)Nevada, USA: IEEE. 1436–1441.

Parquet, Dan T., & Boggs, D. W. (1995). Alternatives To HASL : Users Guide For

Surface Finishes By. Electronic Packaging and Production, 35(9), 38–42.

Pascariu, G., Cronin, P., & Crowley, D. (2003). Next-generation electronics packaging

using flip chip technology. Advanced Packaging, 12(11), 21-22.

Paw, W., Nable, J., & Swanson, J. (2008). “Behind the Scenes” of Effective OSP

Protection in Pb-free Processing. Proc. of the 3rd Int. Conf. Microsystems,

Packaging, Assembly & Circuits Technolog (IMPACT). Taiwan, China: IEEE.

pp. 411–413.

Pecht, M. (1991). Handbook of electronic package design (vol.76).CRC Press.

Phil Zarrow and Debra Kopp. (1996). Organic Solderability Preservatives. Circuits

Assembly, 32 – 35.

Pun, K., Islam, M. N., & Ng, T. W. (2014). ENEG and ENEPIG Surface Finish for

Page 63: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

162

Long Term Solderability. Proc. of the 15th Int. Conf. on Electronic Packaging

Tecnology (ICEPT). Chengdu, China: IEEE. pp. 1–5.

Ramesham, R. (2007). Reliability Assessment of Advanced Flip-Chip Interconnect

Electronic Package Assemblies Under Extreme Cold Temperatures Down to -190

°C and -120 °C. Journal of Microelectronics and Electronic Packaging, 4(4),

155–166.

Ramos, G., Gmbh, A. D., & Metzger, D. (2010). Benefits of Pure Palladium for ENEP

and ENEPIG Surface Finishes. Proc. of the 3rd Conf. on Electronic System-

Integration Technology (ESTC). Berlin, Germany: IEEE. pp. 1–6.

Rasmussen, F. E., Heschel, M., & Hansen, O. (2003). Batch Fabrication of Through-

Wafer Vias In CMOS Wafers for 3-D Packaging Applications. Proc.of the 53rd

Conf. on Electronic Components and Technology. Louisiana, USA: IEEE. 634–

639.

Reid, M., Pomeroy, M. J., & Robinson, J. S. (2004). Microstructural instability in

coated single crystal superalloys. Journal of Materials Processing Technology,

153–154, 660–665.

Reid, M., Punch, J., Collins, M., & Ryan, C. (2008). Effect of Ag content on the

microstructure of Sn-Ag-Cu based solder alloys. Soldering & Surface Mount

Technology, 20(4), 3–8.

Salam, B., Ekere, N. N., & Rajkumar, D. (2001). Study of the Interface Microstructure

of Sn-Ag-Cu Lead-Free Solders and the Effect of Solder Volume on Intermetallic

Layer Formation. Proc. of the 51st Conf. on Electronic Components and

Technology. Florida, USA: IEEE. pp. 471–477.

Salam, B., Virseda, C., Da, H., Ekere, N.N. & Durairaj (2004). Reflow profile study

of the Sn-Ag-Cu solder. Soldering & Surface Mount Technology 16(1), 27-34.

Saliza Azlina, O., Ourdjini, A., Amrin, A., & Siti Rabiatull Aisha, I. (2013). Effect of

Solder Volume on Interfacial Reaction between SAC405 Solders and

EN(B)EPIG Surface Finish. Advanced Materials Research, 845, 76–80.

Saliza Azlina, O., Ourdjini, A., & Ibrahim, M. H. I. (2015). Comparison between

Page 64: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

163

SAC405 Lead-Free Solders and EN(P)EPIG and EN(B)EPIG Surface Finishes.

Applied Mechanics and Materials, 773–774, 232–236.

Saliza Azlina, O., Ourdjini, A., Siti Rabiatull Aisha, I., & Azmah Hanim, M. A. (2011).

Effect of Different Aging Temperatures on Interfacial Reaction between SAC305

and ENEPIG Surface Finish. Advanced Materials Research, 415–417, 1181–

1185.

Sapkal, S., Bhagwat, A., Bendrikar-shinde, D., Vadhwania, Z., Gondil, R., & Waikar,

R. (2015). Parametric Analysis of Electroless Nickel Plating - A Review. Proc.

of the National Conf. on Modeling, Optimization and control

(NCMOC).Maharashtra, India: IEEE. pp. 1-5.

Schlesinger, M. (2010). Electroless and Electrodeposition of Silver. in Schlesinger, M.

& Paunovic, M. (2010). Modern Electroplating: Fifth Edition. Canada: John

Wiley & Sons. Inc. pp. 131-138.

Schueller, R. (2005). Considerations for Selecting a Printed Circuit Board Surface

Finish. DFR Solution. Mineapolis, USA. pp. 1–8.

Sharif, A., Chan, Y. C., Islam, M. N., & Rizvi, M. J. (2005). Dissolution of electroless

Ni metallization by lead-free solder alloys. Journal of Alloys and Compounds,

388(1), 75–82.

Sharif, A., Chan, Y. C., & Islam, R. A. (2004). Effect of volume in interfacial reaction

between eutectic Sn-Pb solder and Cu metallization in microelectronic

packaging. Materials Science and Engineering B: Solid-State Materials for

Advanced Technology, 106(2), 120–125.

Shnawah, D. A., Sabri, M. F. M., & Badruddin, I. A. (2012). A review on thermal

cycling and drop impact reliability of SAC solder joint in portable electronic

products. Microelectronics Reliability, 52(1), 90–99.

Siewert, T., Liu, S., Smith, D. R., & Madeni, J. C. (2002). Database for Solder

Properties with Emphasis on New Lead-Free Solders. NIST & olorado School of

Mines. Release, 4. pp. 1–77.

Siti Rabiatul Aisha, I., Ourdjini, A., Azmah Hanim, M. A., & Saliza Azlina, O.

Page 65: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

164

(2015a). Development of Diffusion Barrier Layer On Copper-Printed Circuit

Board Using Electroless Nickle Plating Method. International Journal of

Computational Methods and Experimental Measurements, 3(4), 329–339.

Siti Rabiatul Aisha, I., Ourdjini, A., Azmah Hanim, M. A., & Saliza Azlina, O.

(2015b). Effect of reflow soldering profile on intermetallic compound formation.

International Journal of Computer Applications in Technology, 52(4), 244.

Siti Rabiatul Aisha, I., Ourdjini, A., & Saliza Azlina, O. (2016). The Effectiness of

Bismuth Addition to Retard the Intermetallic Compound Formation.

International Journal of Chemical, Molecular, Nuclear, Material and

Metallurgical Engineering, 10(1), 107–111.

Slocum, D. (2006). Surface Finishes Utilized in The PC Industry. MULTEK. pp. 1–26.

So, A. C. K., & Chan, Y. C. (1996). Reliability studies of surface mount solder joints

- effect of Cu-Sn intermetallic compounds. IEEE Transactions on Components,

Packaging, and Manufacturing Technology: Part B, 19(3), 661–668.

Song, F., Lee, S. W. R., Newman, K., Sykes, B., & Clark, S. (2007). Brittle Failure

Mechanism of SnAgCu and SnPb Solder Balls during High Speed Ball Shear and

Cold Ball Pull Test. Proc. of the 57th Conf. on Electronic Components and

Technology (ECTC). Reno, Nevada: IEEE. 364–372.

Sudagar, J., Lian, J., & Sha, W. (2013). Electroless Nickel, Alloy, Composite and Nano

Coatings-A Critical Review. Journal of Alloys and Compounds, 571, 183–204.

Sun, P., Andersson, C., Wei, X., Cheng, Z., Shangguan, D., & Liu, J. (2006). High

temperature aging study of intermetallic compound formation of Sn–3.5Ag and

Sn–4.0Ag–0.5Cu solders on electroless Ni(P) metallization. Journal of Alloys

and Compounds, 425(1–2), 191–199.

Sweatman, K. (2009). Hot Air Solder Leveling in the Lead-free Era. Global SMT &

Packaging. Las Vegas, Nevada. pp. 10–18.

Szendiuch, I. (2011). Development in electronic Packaging - Moving to 3D system

configuration. Radioengineering, 20(1), 214–220.

Tanaka, H., Tanimoto, M., Matsuda, A., Takeouno, Kurihara, M., & Shiga, S. (1999).

Page 66: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

165

Pb-Free Surface-Finishing on Electronic Components ’ Terminals for Pb-Free

Soldering Assembly. Electronic Materials, 28(11), 1216–1223.

Tian, Y., Hang, C., Wang, C., Yang, S., & Lin, P. (2011). Effects of bump size on

deformation and fracture behavior of Sn3.0Ag0.5Cu/Cu solder joints during shear

testing. Materials Science and Engineering: A, 529, 468–478.

Tong, K. H., Ku, M. T., Hsu, K. L., Tang, Q., Chan, C. Y., & Yee, K. W. (2006). The

Evolution of Organic Solderability Preservative ( OSP ) Process in PCB

Application. Proc. of the Int. Conf. on Microsystems, Packaging, Assembly &

Circuits Technology (IMPACT). Taipei, China: IEEE. pp. 43–46.

Tongxiang, L., Wenli, G., Yinghui, Y., & Chunhe, T. (2008). Electroless plating of

silver on graphite powders and the study of its conductive adhesive. International

Journal of Adhesion and Adhesives, 28(1–2), 55–58.

Tsai, T. N. (2012). Thermal parameters optimization of a reflow soldering profile in

printed circuit board assembly: A comparative study. Applied Soft Computing

Journal, 12(8), 2601–2613.

Tsao, L. C. (2011). Evolution of nano-Ag3Sn particle formation on Cu-Sn

intermetallic compounds of Sn3.5Ag0.5Cu composite solder/Cu during

soldering. Journal of Alloys and Compounds, 509(5), 2326–2333.

Tseng, C. F., Jill Lee, C., & Duh, J. G. (2013). Roles of Cu in Pb-free solders jointed

with electroless Ni(P) plating. Materials Science and Engineering A, 574, 60–67.

Tsukamoto, H., Nishimura, T., Suenaga, S., & Nogita, K. (2010). Shear and tensile

impact strength of lead-free solder ball grid arrays placed on Ni (P)/Au surface-

finished substrates. Materials Science and Engineering: B, 171(1–3), 162–171.

Tummala R. R. (2001). Fundamental of Microsystems Packaging. New York:

McGraw-Hill.

Tummala, R., Wong, C. P., & Drive, F. (1997). Materials in Next Generation of

Packaging Georgia Institute of Technology. Advanced Packaging, 1–3.

Tu, X. X., Yi, D., Wu, J. & Wang, B. (2017). Influence of Ce addition on Sn-3.0Ag-

0.5Cu solder joints: Thermal behaviour, microstructure and mechanical

Page 67: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

166

properties. Journal of Alloys and Compounds. 698(2017), 317-328

Vianco, P. T. (2008). Performance an overview of surface finishes and their role in

printed circuit board solderability and solder joint performance. Circuit World,

25(1), 6–24.

Vianco, P. T. (2015). Hand soldering basics. Welding Journal. 47-53.

Wang, S. J., Kao, H. J., & Liu, C. Y. (2004). Correlation between interfacial reactions

and mechanical strengths of Sn(Cu)/Ni(P) solder bumps. Journal of Electronic

Materials, 33(10), 1130.

Wang, S. J., & Liu, C. Y. (2003). Study of interaction between Cu-Sn and Ni-Sn

interfacial reactions by Ni-Sn3.5Ag-Cu sandwich structure. Journal of Electronic

Materials, 32(11), 1303–1309.

Wang, W., Choubey, A., Azarian, M. H., & Pecht, M. (2009). An assessment of

immersion silver surface finish for lead-free electronics. Journal of Electronic

Materials. 38, 815–827.

Wang, X. J., Zeng, Q. L., Zhu, Q. S., Wang, Z. G., & Shang, J. K. (2010). Effects of

Current Stressing on Shear Properties of Sn-3.8Ag-0.7Cu Solder Joints. Journal

of Materials Science & Technology, 26(8), 737–742.

Wei, T. C., & Daud, A. R. (2002). The effects of aged Cu-Al intermetallics to electrical

resistance in microelectronics packaging. Microelectronics International, 19(2),

38–43.

Wiese, S., Schubert, A., Walter, H., Dudek, R., & Feustel, F. (2001). Constitutive

Behaviour of Lead-free Solders vs . Lead-containing Solders - Experiments on

Bulk Specimens and Flip-Chip Joints. Proc. of the 51st Conf. on Electronic

Components Technology. Florida, USA: IEEE. pp. 890–902.

Wong, C. P., & McBride, R. (1994). Preencapsulation cleaning methods and control

for microelectronics packaging. IEEE Transactions on Components, Packaging,

and Manufacturing Technology: Part A, 17(4), 542–552.

Wright, A. (2015). Printed Circuit Board Surface Finishes-Advantages and

Disadvantages. Epec Engineered Tecnologies. Duchaine BLDVD, New Bedford.

Page 68: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

167

1–15.

Wu, A. T., Chen, M. H., & Huang, C. H. (2009). Formation of intermetallic

compounds in SnAgBiIn solder systems on Cu substrates. Journal of Alloys and

Compounds, 476(1–2), 436–440.

Wu, C. M. L., Yu, D. Q., Law, C. M. T., & Wang, L. (2004). Properties of lead-free

solder alloys with rare earth element additions. Materials Science and

Engineering R: Reports, 44(1), 1–44.

Xu, S., Habib, A. H., Pickel, A. D., & McHenry, M. E. (2015). Magnetic nanoparticle-

based solder composites for electronic packaging applications. Progress in

Materials Science, 67, 95–160.

Yang, J., Huang, J. C., Huang, M., Ku, J. L., Hsieh, A., & Li, K. C. (2010). Failure

analysis of ENIG surface finish pad. Proc. of the 5th Int. Conf. on Microsystems

Packaging Assembly and Circuits Technology. Taipei Hangang, China: IEEE. pp

1–4.

Yang, M., Li, M., Wang, L., Fu, Y., Kim, J., & Weng, L. (2011). Cu 6Sn 5 morphology

transition and its effect on mechanical properties of eutectic Sn-Ag solder joints.

Journal of Electronic Materials, 40(2), 176–188.

Yang, S. C., Chang, C. C., Tsai, M. H., & Kao, C. R. (2010). Effect of Cu

concentration, solder volume, and temperature on the reaction between SnAgCu

solders and Ni. Journal of Alloys and Compounds, 499(2), 149–153.

Yanhong, T., Shihua, Y., Chunqing, W., Xuelin, W., & Pengrong, L. (2010). Volume

Effect of Shear Fracture Behavior of Sn3. 0Ag0. 5Cu/Cu Lead-free Solder Joints.

Acta Metall Sin, 46(3), 366–371.

Yeh, C. L., & Lai, Y. S. (2006). Transient fracturing of solder joints subjected to

displacement-controlled impact loads. Microelectronics Reliability, 46(5–6),

885-895.

Yin, L., Li, W., Wei, S., & Xu, Z. (2011). Size and Volume Effects in Microscale

Solder Joint of Electronic Packaging. Proc. of the 12nd Int. Conf. on Electronic

Packaging Technology and High Density Packaging (ICEPT-HDP). Shanghai,

Page 69: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

168

China: IEEE. pp. 832–834.

Yoon, J., & Jung, S. (2005). Interfacial reactions between Sn – 0 . 4Cu solder and Cu

substrate with or without ENIG plating layer during reflow reaction. Alloys and

Compounds, 396, 122–127.

Yoon, J. W., & Jung, S. B. (2008). Effect of immersion Ag surface finish on interfacial

reaction and mechanical reliability of Sn-3.5Ag-0.7Cu solder joint. Journal of

Alloys and Compounds, 458(1–2), 200–207.

Yoon, J. W., Kim, S. W., & Jung, S. B. (2005a). IMC morphology, interfacial reaction

and joint reliability of Pb-free Sn-Ag-Cu solder on electrolytic Ni BGA substrate.

Journal of Alloys and Compounds, 392(1–2), 247–252.

Yoon, J. W., Kim, S. W., & Jung, S. B. (2005b). Interfacial reaction and mechanical

properties of eutectic Sn-0.7Cu/Ni BGA solder joints during isothermal long-

term aging. Journal of Alloys and Compounds, 391(1–2), 82–89.

Yoon, J. W., Noh, B. I., & Jung, S. B. (2011). Comparative study of ENIG and

ENEPIG as surface finishes for a Sn-Ag-Cu solder joint. Journal of Electronic

Materials, 40(9), 1950–1955.

Yoon, J. W., Noh, B. I., Kim, B. K., Shur, C. C., & Jung, S. B. (2009). Wettability and

interfacial reactions of Sn-Ag-Cu/Cu and Sn-Ag-Ni/Cu solder joints. Journal of

Alloys and Compounds, 486(1–2), 142–147.

Yu, D. Q., & Wang, L. (2008). The growth and roughness evolution of intermetallic

compounds of Sn-Ag-Cu/Cu interface during soldering reaction. Journal of

Alloys and Compounds, 458(1–2), 542–547.

Yu, D. Q., Wu, C. M. L., Law, C. M. T., Wang, L., & Lai, J. K. L. (2005). Intermetallic

compounds growth between Sn-3.5Ag lead-free solder and Cu substrate by

dipping method. Journal of Alloys and Compounds, 392(1–2), 192–199.

Zeng, G., Xue, S., Zhang, L., Gao, L., Dai, W., & Luo, J. (2010). A review on the

interfacial intermetallic compounds between Sn-Ag-Cu based solders and

substrates. Journal of Materials Science: Materials in Electronics, 21(5), 421–

440.

Page 70: INTERFACIAL REACTION BETWEEN SAC305 AND SAC405 … · melalui proses penuaan dengan masa penuaan yang berbeza. ... 2.3.1 Hot-air solder levelling (HASL) 12 2.3.2 Organic solderability

169

Zeng, K., & Tu, K. N. (2002). Six cases of reliability study of Pb-free solder joints in

electronic packaging technology. Materials Science and Engineering, 38, 55–

105.

Zeng, K., Vuorinen, V., & Kivilahti, J. K. (2002). Interfacial Reactions Between Lead-

Free SnAgCu Solder and Ni(P) Surface Finish on Printed Circuit Boards. IEEE

Transactions on Components and Packaging Manufacturing, 25(3), 162–167.

Zhang, L., He, C. W., Guo, Y. H., Han, J. G., Zhang, Y. W., & Wang, X. Y. (2012).

Development of SnAg-based lead free solders in electronics packaging.

Microelectronics Reliability, 52(3), 559–578.

Zhang, L., Xue, S. B., Zeng, G., Gao, L. L., & Ye, H. (2011). Interface reaction

between SnAgCu/SnAgCuCe solders and Cu substrate subjected to thermal

cycling and isothermal aging. Journal of Alloys and Compounds, 510(1), 38–45.

Zheng, Y., Hillman, C., McCluskey, P. (2002). Intermetallic Growth on PWBs

Soldered with Sn3.8Ag0.7Cu. Proc. of the 52nd Conf. Electronic Components and

Technology. San Diego, United State: IEEE. 1226–1231.

Zhou, Y., Yang, P., & Yuan, C. (2013). Electrochemical Migration Failure of the

Copper Trace on Printed Circuit Board Driven by Immersion Silver Finish.

Chemical Engineering Transactions, 33, 559–564.

Zimprich, P., Saeed, U., Betzwar-Kotas, A., Weiss, B., & Ipser, H. (2007). Mechanical

Size Effects in Miniaturized Lead-Free Solder Joints. Journal of Electronic

Materials, 37(1), 102–109.