Stress Tabs Results Nov06,2013

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Ejemplo de Stress en Electrodepositación

Transcript of Stress Tabs Results Nov06,2013

  • Stress tabs Study06/11/2013

  • Dec-13 2

    Content

    1. Stress tabs study silver process with cumulative layers1. Stress sum up

    1. Stress sum up characterization2. Individual stress per each bath

    1. Stress sum up

    2. Stress tabs study copper process with cumulative layers1. Stress sum up

    1. Stress sum up characterization2. Individual stress per each bath

    1. Stress sum up

    3. Comparison of individual stress of each layer4. Final stress: Silver vs Copper5. Stress referential6. POP plating solution using additives7. Stress measurement

  • ContextHigh rate of blisters present in our actual plating process. Defectdetected mainly on silver QLF. hypothesis is that after plating the layers had a stress that could

    impact in a direct way the blistering on them. Stress study is developed to analyse the behavior of the deposit.

    Compresive stress Tensile stress

  • 1.- Stress tabs study silver process with cumulative layers

    Individual and accumulated coatings were check with the stress tabs to see how is the behavior of each deposit in our actual silver process.

  • Nickel electroless bath

    Compressive stress

    Silver bath

    Compressive stress

    Nickel electroless + Ag

    Compressive stress

    Compressive stress

    Compressive stress

    Line 1 + Oven

    Line 1 + Oven + Ni electro previous Line 1 + Oven + Line 2

    Compressive stress

    Line 1 + Oven + Line 2 + oven

    Compressive stress

    1.- Stress tabs study SILVER process with cumulative layers

  • SummaryCummulative

    ProcessCommulative

    Stress followingElectroless nickel (EN) Compressive

    Ag Compressive

    EN+Ag Compressive

    EN+Ag+8hr HT200C Compressive

    EN+Ag+8hr HT200C+Flash NiElectro Compressive

    EN+Ag+8hr HT200C+Flash NiElectro+2nd EN +NiElectro Compressive

    EN+Ag+8hr HT200C+Flash NiElectro+2nd EN +NiElectro+1hrHT200C Compressive

    Observation:Comulative stress on stress tabs has shown the same type of stess on silver process.

    Then is needed to evaluate the individual stress per each type of layer/process in order to have a better understanding of each coating.

    1.1.- Stress sum up.

  • In order to understand the impact of the stress on Blisterseach test was characterized to see its impact from: heat treatment Thermal shock Scrib test

    Type of characterization

    Silver Process

    NIX NIX+Ag NIX+AgPre+Ag NIX+AgPre+Ag+oven Line 1+NIPre Line 1+NIPre+NIX2 Line1+Line2 Line1+Line2+oven

    Compresive X X X X X X X X

    Tensile

    Scrib test result OK OK OK OK OK OK OK OK

    Thermal shock OK OK OK OK OK OK OK OK

    Characterization results

    1.1.1.- Stress sum up characterization.

  • Dec-13 8

    Nickel electroless bath

    Compressive stress

    Silver bath

    Compressive stress

    Electrolytic nickel FLASH

    Compressive stress

    2nd Nickel electroless bath on line 2

    Compressive stress

    Electrolytic nickel

    Compressive stress

    1.2.- Individual stress per each bath

  • SummaryCummulative

    ProcessCommulative

    Stress followingElectroless nickel (EN) Low-Compressive

    Ag Very low - Compressive

    Nickel electrolytic FLASH Compressive

    Electroless nickel Compressive

    Nickel electrolytic Very high - Compressive

    According to individual stress observation has been detected that the electrolytic nickel has a very high compressive stress compared with the others

    Hypothesis:This high compressive stress and good adherence could lead the coating to remove the underlayers between electroless nickel and silver due to very low compression of silver that seems to be very ductil.

    1.2.1.- Stress sum up.

  • 2.- Stress tabs study COPPER process with cumulative layers

    Individual and accumulated coatings were check with the stress tabs to see how is the behavior of each deposit in our actual copper process.

  • Nickel electroless

    Compressive stress

    Line 1 + Oven + Ni electro previous+ 2nd Electroless nickel

    Null tensile stressCompressive stress

    Copper

    High Tensile stress

    Nickel electroless + Copper

    Mid Tensile stress Low tensile stress

    Line 1 + Oven (copper)

    Low tensile stress

    Line 1 + Oven + Ni electro previousLine 1 + Oven + Ni electro previous+ 2nd Electroless nickel+ Ni Eletro

    Low compressive stress

    Line 1 + Oven + Ni electro previous+ 2nd Electroless nickel+ Ni Eletro+Oven

    Mid compressive stress

    2.- Stress tabs study copper process with cumulative layers

  • SummaryCummulative

    ProcessCommulative

    Stress followingElectroless nickel (EN) Compressive

    Cu High tensile

    EN+Cu Mid tensile

    EN+Cu+1hr HT200C Low tensile

    EN+Ag+8hr HT200C+Flash NiElectro Mid tensile

    EN+Ag+8hr HT200C+Flash NiElectro+2nd EN Null tensile

    EN+Ag+8hr HT200C+Flash NiElectro+2nd EN +NiElectro Null Compresive

    EN+Ag+8hr HT200C+Flash NiElectro+2nd EN +NiElectro+1hrHT200C Mid Compressive

    Commulative stress on stress tabs has shown the same type of stess on silver process.

    Then is needed to evaluate the individual stress per each type of layer/process.

    2.1.- Stress sum up

  • 2.1.1.- Stress sump up characterization

    Type of characterization

    Copper ProcessNIX NIX+Cu NIX+Cu+Oven Line 1+NIPre Line 1+NIPre+NIX2 Line1+Line2 Line1+Line2+oven

    Compresive X X X

    Tensile X X X X

    Scrib test result OK OK OK OK OK OK OKThermal shock OK OK OK OK OK OK OK

    In order to understand the impact of the stress on Blisterseach test was characterized to see its impact from: heat treatment Thermal shock Scrib test

    Characterization results

    First nickel layers is compresive, but immediatly after copper bath the deposit becomes tensile, and it stays in this way until electrolytic nickelwhere changes to compresive. This means that the sum of the stress of all the line 1 until electroless nickel of line 2 is not giving compresivestress, just after electrolytic nickel it has this effect.

    Scrib test and thermal shock are Ok for all the accumalated coatings.

  • Dec-13 14

    Nickel electroless bath

    Compressive stress

    Electrolytic nickel FLASH

    Compressive stress

    2nd Nickel electroless bath on line 2

    Compressive stress

    Electrolytic nickel

    Compressive stress

    2.2.- Individual stress per each bathCopper

    High Tensile stress

  • 2.2.1.- Stress sum up

    SummaryCummulative

    ProcessCommulative

    Stress followingElectroless nickel (EN) Low-Compressive

    Cu Very high tensile

    Nickel electrolytic FLASH Compressive

    Electroless nickel Compressive

    Nickel electrolytic Very high - Compressive

    According to individual stress observation has been detected that the electrolytic copper has a very high tensile stress compared with the others, in other side electrolytic copper has the opposite phenomena with very high compresive stress.

    Hypothesis:The different combination of stress of copper process could explain that plated parts with copper underlayer are less sensitive to stress and thus to blisters due to the opposite forces that copper process present vs the electrolytic nickel (Tensile vs compressive)

  • Type of characterization

    INDIVIDUAL TESTNIX Ag Cu NIPre NIX2 NIE

    Compresive X X X X X

    Tensile XScrib test result OK OK OK OK OK OK

    Thermal shock OK OK OK OK OK OK

    3. - Comparison of individual stress of each layer

    All individual stresses are compresive, only copper is tensile, this is why thehypothesis of blisters appear in silver process.

    Scrib test and thermal shock are Ok for all the accumalated coatings.

  • 4.- Final stress: Silver vs Copper

    Line 1 + Oven + Line 2 + oven

    Compressive stress

    Line 1 + Oven + Ni electro previous+ 2nd Electrolessnickel+ Ni Eletro+Oven

    Mid compressive stress

    Regarding the different stress behavior between Silver and Copper has been observed that Silver process has an important compressive stress at the end of the plating process which include EN, Silver, NiElectroFLASH+EN+Nielectro compared with the copper process.

    This phenomena can be an input to issue of lack of adhesion.

  • 5.- Stress referential

    Different type of stress on metals.

    Stress on plating process can be modified by the addition of organic agents on plating solutions known as carriers and brightneers, these agents have an important contribution to stress either compressive or tensile on each plating solution.

  • 6.- POP solutions using additives.

    Copper: CarrierD / Carrier / additive (Brightener)

    Silver: Brightener

    Electrolytic nickel Carrier, Brightener and wetting agent.

    There is no too much information available about stress influence from the different additives there are being usedinto the plating solutions like:

    Efect of min/max carrier on Tensile / Compressive stress ?Efect of min/max brightener on Tensile / Compressive stress ?Efect of min/max wetting agent on Tensile / Compressive stress ?

    In order to answer above questions is needed to have quantitative stress measurement

  • 7.- Stress measurement

    This instrument is to measure in a quantitave way the stress for the different plating solutions.

    The instrument is already in Obregon and in progress to start working with it, so far is not a priority