基于電磁攪拌的無鉛互連新方法的初步研究.pdf

1、華中科技大學碩士學位論文基于電磁攪拌的無鉛互連新方法的初步研究姓名：胡炎祥申請學位級別：碩士專業(yè)：材料加工工程指導教師：吳豐順20060429華中科技大學碩士學位論文IIAbstractTheelectronicpackagingassemblyindustryisnowleadingtotheprocessofleadfreeminiature.Howevermanyreliabilityproblemsoccurredinthisp

2、rocesssuchasthemicrostructureofsolderalloysdistributeddisproptionatelyairholesvoidsfmedinthesolderjointsexcessiveintermetalliccompound(IMC)fmationinsolderpadinterface.Thetraditionalwaytosolvethisproblemisaddingalloyeleme

3、ntsteducecrystalgrainsizeprolongingthetimespentaboveliquidlinedevelopingnewfluxsoastoeliminatevoidsfmedinthesolderjoints.Anewelectronicpackagingassemblyleadfreeinterconnectmethodbasedonelectromagicstirringhasbeenproposed

4、inthisthesis.Electromagicstirringcanimprovethereliabilityofleadfreesolderjointsbyoptimizingtheleadfreesolder’ssolidificationcrystallizationbehavi.Althoughelectromagicstirringisatraditionaltechniquehasbeenwidelyusedinthef

5、ieldsofelectromagiccastingmagiccontrolledweldingfmanyyearsnumerousspecificproblemswillbearousedaslongastheelectromagicstirringtechnologyisbroughtintothefieldofelectronicmanufacturing.Thewkingprinciplebasictheiesofelectro

6、magicstirringhavebeenintroducedbrieflythenthefeasibilityofapplyingtheelectromagicstirringmethodinthefieldsofelectronicpackagingassemblyleadfreeinterconnectfieldhasbeenprofoundlydiscussed.Ni(nickel)isoneofaferromag.Basedo

7、ncomputernumericalsimulationtheinfluenceofNilocatedintheunderbumpmetallization(UBM)layerpadplatedlayeronthedistributionofmagicfcelinehasbeenstudied.Ithasbeenfiguredouthowtodepositthecoilsinthepracticalelectromagicstirrin

8、gprocess.WhentheCuwaschoseassolderwettinglayerfUBMpadplatedlayerinsteadofNiCuisnotamagicmaterialithasnoinfluenceonthedistributionofmagicfcelineinthesolderbulkthesimulationresultshasbeendemonstratedit.Leadfreesolderisoflo

9、welectricalresistivitythusthecurrent’sskineffectsmayeasilyoccur.InthisthesistherespectiveinterconnectionsofthedistributionoftheinducedcurrentdensitytheinfluencedrangeofLentzfcewiththefrequencyofcoilcurrentwerealsosimulat