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Engineering Specification &

Design Portfolio

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Engineering Design

System Design

Detail Design

Start Here!

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Design Process• Define Functional Needs• Functional Specification (Continuous updating)• Engineering Specification (Continuous updating)• Detail Design

– Design for Manufacturing– Design for Assembly and Disassembly– Life Cycle Design

• Prototyping• Production• Product Launch • Maintenance and Support• Product Recycling

Concurrent and Iterative Activities

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Design Procedure

Functional NeedsFunctional Specification

Design Analysis

Engineering Specification

Detail DesignLife Cycle Design

Design for Assembly and DisassemblyDesign for Manufacturing

Subsystem Decomposition

ManufacturingProcess

Plan

Maintenance

Recycling

Product

Marketing

Matl. Selection

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Design Specification• Functional Specification

– Overall requirements– Key functionalities– Overall dimensions– Key performance characteristics– Layout drawing

• Engineering Specification– Detail performance requirements– Subsystems and subsystems detail requirements– All relevant dimensions – Engineering drawings

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Design Portfolio• Design specification - Contract• Design Schedule• Functional design

– Design alternatives– Design evaluation

• Final design solution– Design model and analysis– Engineering drawings– Process Plan

• References• Meeting notes

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System Design

• Define Functional Needs

• Functional Specification (Continuous updating)– Review existing information

• Existing designs, patents, codes, legislation, literature search

– Decomposition into subsystems• Overall layout

• Subsystem relationship

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Flip Chip Bonder

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Functional Specification Development

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Process Flow IStep 1a - Pattern developed on bare silicon

template

1. Clean silicon substrate by sulfuric acid & hydrogen peroxide at 120°C for 10mins

2. Rinse with deionized water and dry clean

3. Spin coat standard photoresist

4. Conduct photolithography by UV exposure

5. Wet etch the pattern by KOH (anisotropic etching)

6. Photoresist stripping

7. Rinse with deionized water and dry clean

8. Dicing

Silicon Template

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Process Flow II

Step 1b - Soft mould Preparation

1. Apply mould release (silicone) on silicon template

2. Clean another silicon substrate by sulfuric acid & hydrogen peroxide at 120°C for 10mins

3. Rinse with deionized water and dry clean

4. Spin coat polymer (PMMA / PDMS)

Silicon Template

Silicon TemplatePolymer

Pressure

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Process Flow IIIStep 1c - Pattern transfer to the

soft mould– Apply silicon template onto

polymer with pressure (<5bars)

– Curing polymer with suitable conditions

– Release of silicon template

• Step 1d - Soft mould fabricated

Heat

Heat

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Process Flow IV

Step 2 - Dipping of soft mould on conductive polymer

1. Apply a layer of conductive polymer into the paste pot

2. Turning the pot and set the height of the paste by height adjustable blade

3. Dipping of soft mould on the conductive polymer

Silicon substrate

Conductive Polymer

PDMS / PMMA Mould

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Process Flow V

Step 3 - Die preparation

1. Dicing

2. Load into magazine

Wafer Magazine

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Process Flow VI

Step 4 - Formation of interconnect

1. Alignment is conducted between soft mould and IC die

2. Apply soft mould onto the die (displacement control)

3. Lifting of the soft mould for next cycle

4. Soft mould will undergo Step 2 for next die

IC die

Pressure

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Process Flow VII

Step 5 - Assembly process

1. Bumped chip is flipped

2. Alignment is conducted between bumped IC die and substrate

3. Apply bumped IC die onto the substrate (displacement control)

Sub-mount / substrate

Bumped Chip

IC die

Pressure

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Process Flow VIII

Step 6 – Curing

1. Batch if assembled package is collected

2. Batch curing of conductive polymer in conventional oven

3. Underfilling is optional

Underfill IC die

Heat

Heat

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Functional Specification I

• Target Package

• Base Table

Pad size 20μm - 100μm

Pitch (Min) 20μm

Chip size 0.4mm x 0.4mm – 10mm x 10mm

Size 40mm x 40mm x 0.5mm

Material handling Class epoxy, ceramic, glass, flim

Alignment accuracy X±2μm, 3σY±2μm, 3σθ±0.01˚ 3σ

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Functional Specification II• Bonding Head

• Camera Table

Bonding pressure <5barHead bonding temperature (max) 400˚C, +30˚C

Temperature accuracy ±1deg

Cooling system Air coolingLoading time Max. 200sec, resolution 0.1sec

Stage Movement 0.5μm per stepLeveling resolution -

Image processing device Gray scale pattern matchingFocusing system

Table movement (x-y motion) 1μm per step2 camera Two side camera

Chip: 0.4-0.6mmSubstrate:1-2mm

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Engineering Specification Development

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Polymer Flip Chip Bonder - Schematic

Camera 1 - WaferCamera 2 - FlipCamera 3 - Substrate

Dipping Bath

Epoxy Pot System Die Pick-up Arm

Wafer System

Substrate Work Holder

Vacuum

Optics 1

Optics 2

Optics 3

Ө X Y Z

Polymer Flip Chip Bonder Schematics

Flipping System

Stamping Arm System

Ejector System

DieOrient-Ө

Flip-ӨFlip-Ө

Flipping SystemSubstrate Work

Holder

Z

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Polymer Flip Chip Bonder

MECH152-06 -L2- 23Polymer Flip Chip Bonder Specification - I

Machine Structure ModuleEpoxy Pot Systemfor Conductive Polymer

Adjustable Epoxy Blade height by Micro-gauge-Feed at 0.5mm/rev.

Dipping for cleaning the Stamping Head

Stainless Steel Container with Ultrasonic cleaning-Frequency >40kHz

Vacuum Systemfor drying up the Stamping Head after cleaning

With filter

Substrate Work Holder - X-travel 100mm, resolution 2.5um/step

- Y-travel 200mm, resolution 2.5um/step

- Z-travel 5mmChassis & Frame Cast Iron & Marble Stone, Casters

with Adjustment Pad

MECH152-06 -L2- 24Polymer Flip Chip Bonder Specification - II

Machine Control ModuleController - Motion control: Pentium 4 grade controller system

- Vision PR: Pentium 4 grade controller systemVision Alignment System

3 set 256-grey scale 1/3” CCD (at Wafer/Flip/Substrate)Adjustable magnification (0.7X – 4.5X)640x480 pixels resolution (2-11 um/pixel)Coaxial and Ring light illuminationPCI Video Capture card (PAL, 30 frames/sec)Manual adjustment and focusing range-X-travel 10mm-Y-travel 10mm-Z-travel 10mm

Motion Control System Digital Signal Processing (DSP) control for-Ejector System (X, Y, EjectorCap-Z, EjectorPin-Z)-Wafer System (X, Y)-Substrate Work Holder (X, Y, Z)-Flipping System (X, Y, DieOrient-Ө, Flip-Ө)-Die Pick-up Arm (Z, Ө)-Stamping Arm System (X, Y, Z)

Air Source Vacuum 0.8mmHg / Compressed Air 0.1-0.2 barDAC Controller 8-bit resolutionADC Controller 0-5V DCTemperature Controller

400ºC (max) / +30ºC ramp /10ºC accuracy

MECH152-06 -L2- 25Polymer Flip Chip Bonder Specification - III

Wafer Handling ModuleTarget Packages LED, COG, COF

Wafer System - X-travel 150mm, resolution 5um/step- Y-travel 150mm, resolution 5um/step

Ejector System - X-travel ±10mm, resolution 1.5um/step- Y-travel ±10mm, resolution 1.5um/step- EjectorCapZ-travel 24mm, 4um/step- EjectorPinZ-travel 24mm, 4um/step

Wafer Handling - 6” Wafer with 8” Ring- Conversion Kit for 2” Waffle Pack

Missing die detector

Photo sensor

MECH152-06 -L2- 26Polymer Flip Chip Bonder Specification - IV

Pick, Dip, Flip ModuleVacuum holder 1.0 mmHg

Force Control Sensor 3 set (Pick/Stamp/Flip)Range 0-150gDAC control

Die Pick-up Arm - Z-travel 5mm- Ө -travel 180º, 0.45º/step

Stamping Arm System

- X-travel 200mm, resolution 5um/step- Y-travel 200mm, resolution 5um/step- Z-travel 100mm

Flipping System - X-travel 10mm, resolution 1.25um/step- Y-travel 10mm, resolution 1.25um/step- Flip-Ө -travel 180º, 0.45º/step- DieOrient-Ө-travel ±180º, 0.45º/step

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System Design

Sub-system I

Sub-system II

Sub-system III

Relationship A Relationship C

Relationship B

Relationship D

Overall

System

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System Design

• Internet

• Patent database – http://www.ttc.ust.hk http://www.ttc.ust.hk

• IP and Patent Search Links (WIPS)– e.g. printer head + Epson

• Research database– http://ustlib.ust.hk http://ustlib.ust.hk

• Database List – (SCOPUS)– Printer head (title) + Epson (Affiliation)

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Design Evaluation MatrixFunction

(Functions in the Functional Specification)

Weighting

(Weighting showing the importance of the

function)

Score

Alternative 1

Alternative 2

Alternative 3

Function 1 W1 R11 R12 R13

Function 2 W2 R21 R22 R23

Function 3 W3 R31 R32 R33

Function 4 W4 R41 R42 R43

Total score R11*W1+R21*W2+ R31*W3+ R41*W4

R12*W1+R22*W2+ R32*W3+ R42*W4

R13*W1+R23*W2+ R33*W3+ R43*W4