國際電子制造商聯盟（iNEMI）日前宣布，將組織新的無鉛相關合作研究項目，主要研究方向包括：無鉛合金選擇，無鉛早期缺陷分析，邊界掃描以及焊膏沉積等。iNEMIrsquo;sroadmappingandgapanalysisactivitieshelpusidentifythosetechnologyandinfrastructuregapswhereitmakessenseforindustrytocollaborativelydevelopcommonsolutions,saidJimMcElroy,CEOofiNEMI.Wefocusoureffortsonactivitiesthatwillleadtoaccelerateddeploymentofnewtechnologies,developmentofindustryinfrastructure,disseminationofefficientbusinesspracticesand/orstimulationofstandards.TheinitiativeswearecurrentlyorganizingaddressneedsidentifiedbyiNEMIroadmapsand,inallcases,representactivitiesthatwouldnothaveasmuchimpactonthesupplychainifundertakenbyasinglecompany.Pb-FreeAlloyAlternativesThisnewiNEMIprojectisbeingorganizedtoprovideindustryguidelinestohelpmakethegrowingproliferationofPb-freealloyseasiertomanage.ManyBGAsuppliersarechangingthealloysusedforPb-freesolderballstoimprovemechanicalshockperformance.Suppliersarealsopromotingavarietyofwavesolderalloystoaddressconcernsaboutcopperdissolution,barrelfill,commonwavedefects,andthehighcostofalloys.Asaresult,thevarietyofPb-freealloysisincreasing.Severalofthesealloyshavelowerlevelsofsilver(Ag)and,therefore,ahighermeltingpoint(upto10?Chigher),whichmayrequireachangeinprintedcircuitassembly(PCA)manufacturingprocesses.Thefirstphaseofthisprojectwillfocusontheanalysisofexistingknowledgeandassessmentofcriticalgaps,andondrivingstandardstohelpmanagesupplychaincomplexityandrisk.Pb-FreeEarlyFailureThisneweffortwilldeterminewhetheralargesamplesizecanrevealPb-freeearlyfailuresinacceleratedthermalfatiguetestingofPb-freesolderjoints.ThephysicalandmetallurgicaldifferencesbetweenSnPbandPb-freesoldershaveadirecteffectonthermalcycleperformance,andthepropertiesandfailurebehaviorofSACsoldersaremarkedlydifferent.IftheoutliersidentifiedinPb-freesolderingthermalfatiguestudiesareafunctionofthestructure/properties,theymaynotbevisibleintherelativelysmallsamplesizeusedinthermalcyclingtests.Ifso,thetraditionalSnPbsamplesize(32)isinadequatetocharacterizethereliabilityofPb-freesolders,andtestdatausingthesesamplesizescouldresultinover-estimationofreliability(i.e.,smallsamplesizecouldmaskearlyPb-freefailures).Theteamplanstodevelopauniquetestvehiclewithalargesamplesize(256eachofthreedifferentcomponenttypes)totestBGAsolderjoints.Testingwillincludetwocomponentsthattendtofailrelativelyquickly(toencourageearlyfailure)andathirdwithaslightlylongerlife,andwillcoverfourconditions:smallspherejoints,largespherejoints,lowstrainrateandhighstrainrate.BoundaryScanAdoptionThisprojectwillpromotewideradoptionofboundaryscan(IEEE1149.1,1149.6andP1581)throughouttheindustry,encouragesemiconductorvendorstoincludethetechnologyintheirproducts,andpromotethedevelopmentoftoolsbyATEvendorstosupportboundaryscanbasedboardtest.IncreasingcircuitdensitiesandspeedsarequicklyreducingelectricaltestpointaccessforPCAtest.BoundaryscanisatechnologythatallowscontinuedtestabilityofPCAs,butitsuserequiresthatitbedesignedintosemiconductordevicesandboardassemblies.Wideravailabilityofcomplyingdevicesisnecessarytoenablecost-efficientandeffectiveboardtestforfuturedesigns.Design-for-testiscurrentlynotacceptedinthegeneralareaofmemorydevices(SRAM,DRAM,flash,etc.).Inaddition,toolstosupportboundaryscanbasedtestneedtobedevelopedandintegratedintomanufacturingtestequipment.Thisprojectproposestobridgethegapbetweenboardtestandboardmanufacturingwherethislackofunderstandingarisesintheuseofdesign-for-test.SolderPasteDepositioniNEMIsfirstregionaldeploymentprojectiscurrentlybeingorganizedinChina.TheSolderPasteDepositionProjectwillinvestigatesolutionstodepositingdifferentvolumesofsolderpasteonthesameboard.Asboarddensityincreasesandcomponentsbecomesmaller,fine-pitchcomponents(whichrequiresmallervolumesofsolderpaste)oftenappearnexttolargercomponents(whichrequiremorepaste)andasingle-thicknessstencilcannotsatisfyallofthecomponentsinthesameprintingprocess.Inthesesituations,astepstencilistheleastexpensiveandmostpopularsolution.However,thechallengeisindeterminingtheproperdistancebetweenthevariouscomponentsbecausethestepstencilmayaffectthethicknessofthesolderpastedeposition,especiallyforminiatureandfine-pitchcomponentslocatedaroundthestep.Theprojectteamproposesto:(1)investigatethekeep-outdistancesofstepstencilsandoutputthedesignrules,(2)identifynewpastedepositiontechnologiesforhigh-densitylayouts,and(3)compareandevaluatethefeasibilityofidentifiedtechnologies,includingthedevelopmentofnewmanufacturingprocessesandequipment.AboutiNEMITheInternationalElectronicsManufacturingInitiativersquo;smissionistoidentifyandclosetechnologygaps,whichincludesthedevelopmentandintegrationoftheelectronicsindustrysupplyinfrastructure.Thisindustry-ledconsortiumismadeupofmorethan65manufacturers,suppliers,industryassociationsandconsortia,governmentagenciesanduniversities.iNEMIroadmapstheneedsoftheelectronicsindustry,identifiesgapsinthetechnologyinfrastructure,establishesimplementationprojectstoeliminatethesegaps(bothbusinessandtechnical),andstimulatesstandardsactivitiestospeedtheintroductionofnewtechnologies.Theconsortiumalsoworkswithgovernmentagencies,universitiesandotherfundingagenciestosetprioritiesforfutureindustryneedsandRDinitiatives.iNEMIisbasedinHerndon,Va.(nearWashington,D.C.),withregionalofficesinShanghai,ChinaandLimerick,Ireland.ForadditionalinformationaboutiNEMI,visithttp://www.inemi.org.
