affection

13.09.05/Wi

Checklistfortheplatingofbondablesurfacesinreel-to-reelplants:

sultsin

allthe

requirementsthemostimportantfactsaresummaridinthefollowingchecklist:

vementofallthecontact-rollershastobecheckedinitiallybeforeeachnew

startingthemachine(everyday).

iccontactusingstainlesssteelbrusheswithfinewavyhairs.

3.O-ringsofallcontact-rollersmustnottouch/scratchthebondingarea.

alsovalidforallplastic-partswithinthereel-to-reelmachineespeciallyplating-

cellentriesand-exits.

berrollersintheareasofproductdivertersS-driveorwithintheMeco-Wheelbut

alsothewheelsofstoragetowershastobecheckedforabradedmaterials,andif

necessaryhastobecleanedorexchangedwithnewspareparts.

hangeofaprocessstephastobecheckedaccordinganyinfluenceon

bondabitityincludingartificialageingandbondabilitytests.

ntermediatedriveincluding„dryrun“MecoWheeloranycomparableunitwith

movingmasksshouldbecleanedbasicallybeforeeverystartingthemachine.

airdryermustbesuppliedwithexternalcleanedairtoavoidunknown

ghairpollutionanair-washeris

recommended.

commonlyudwiththeplatingofbondablesilver,alsowiththebondablegold

processitisrecommendabletoextendthereel-to-reelmachinewithatransparent

chamberfollowingthedryingpositionwhichisfedwithcleanedfreshairtoavoidany

badinfluenceoftheaerosol-contaminatedairoftheplatingshop’

alsoincludingthes-drive,theproductstroragetowerandthereeling.

latedreelsshouldnotbestoredinthesameroomwhereplatingtakesplace.

Shrink-wrappingintoplastic-foil.

„unuddistances“is

notpossibletheproductsurfacemustnotcomeintouchwithuncleanedpartsofthe

machine(t-rollerntriesorexitsofplatingcells)Furthermoretheproduct

surfaceshouldnotgetdry.→aftertherinsingsteptheair-knifemustbeswitchedoff

-outrinsing

rexperiencedryingeffectscan

beavoidedifthefirstdrag-outrinsingwater(priortotheunuddistance)isalcalined

alittle.

tdemineralizedwaterrinsingsteps(coldandhotwater)shouldbeexchanged

frequently.→.5µS,optimum<1–2µS;Filtrationof

thelastrinsingwithporewidth<0,5µmisstronglyrecommended.

obementionedthatcurrentdensityofthemultiplestagenickelplatinginreel-

allythefirstplatingcell

shouldberunatlowercurrentdensitytoenforceafinegrainedstructurewithlowest

numberofpores.→Influenceonthegrainstructureofthepuregoldprocess.→Pore

testwillbehelpfultooptimi.

ththenickelelectrolyteitisimportanttotakecareofthemetallicimpurities.→

attheexitofthelastnickelplatingcellthecurrentdensityforashortmomentisvery

lowandcanreachvaluesof„dummyplating“conditions(→codepositionofmetallic

impurities).Dummy-platingwithinthestoragetankisduty.

antyafine-grainedstructureofthegoldlayeralltheplating-andbath-

parametershastobeobrvedstrictly.

dcomplicationswithbadbondabilitycaudbyincreasingcontentsofmetallic

impurities,especiallycopperandnickelshouldbekeptonalowlevelbyusingthe„Ion

ExchangeResin1“,

eisvalidfororganicimpuritiesthathavetoberemovedperiodicallybyusing

eatmentdoesn’tremoveesntialcomponentsofthe

contextithastobepointedoutthatthethicknessofthegoldlayer

shouldnotunderrunbutalsonotexceedsignificantlythenominalvaluetoavoida

failureofanelectroniccomponentduetoadiffusionbadsocalledKirkendall-effect.

isurfacedefectsorevenhighroughnessqualitycontrolhastobechecked

frequentlyorbetterwitheverynewreel.

udanddecontrolledinterlayerpapermustbeud.

atureofthehotairdryershouldbecheckedandreducedtoalevelaslowas

aturesshouldnotexceed150°C.

etimeofpunchedem-productshouldbeavoidedbecauofunknown

stobecheckedinthe

laboratoryifthepre-treatmentissufficient→afterdegreasingandpicklingtheclod

waterfilmontheproductsurfaceafterrinsingmaynotbreakdowntosingledrops.

hangeoftheudpunchingoilqualitymustbereportedtotheelectroplating

departmenttochecktheefficiencyofthepre-treatmentprocessusingaccording

wetting-tests.