基于超聲激勵的倒裝芯片缺陷檢測技術研究.pdf

1、華中科技大學碩士學位論文基于超聲激勵的倒裝芯片缺陷檢測技術研究姓名：張學坤申請學位級別：碩士專業(yè)：機械電子工程指導教師：廖廣蘭史鐵林20110117華中科技大學碩士學位論文華中科技大學碩士學位論文IIAbstractDefectofflipchip(FC)isalwayshiddenbetweendiesubstratewhichbringsdifficultytoinspectdefectofFC.Indertosolvethepro

2、blemthevibrationmodelisproposedfexplainingthetheyofdefectinspection.NaturalfrequencyofFCvibrationvelocityofsolderbumpsarealsoresearchedwithadefectinspectionmethodbasedonaircoupledultrasonicexcitation.Themaincontentisasfo

3、llowing:1.TensionspringswithmasswereusedtosimplifysolderbumpsofFCthennaturalfrequencyequationofvibrationmodelofFCwasderived.ThetheyshowsthatitsnaturalfrequencycanbedecreasedifthereweredefectivesolderbumpsfFCvibrationvelo

4、cityofdefectivesolderbumpscanbeincreased.2.Adefectinspectionmethodbasedonaircoupledultrasonicexcitationisproposed.InwhichFCisexcitedwithaircoupledultrasoundthenthevibrationsignalismeasuredbyusingalaservibrometertoinspect

5、defectofsolderbumps.3.NaturalfrequenciesofFCswerecalculatedsimulatedmeasured.Researchshowsthatthemethesolderbumpsmissingarethelowerthenaturalfrequenciesare.FFCwithperipheralsolderbumpsifchangingratesofthe3rd~5thnaturalfr

6、equencieswereallhigherthan9%therearesolderbumpsmissingfit.FFCwithareasolderbumpschangingratesofthefirst7naturalfrequenciesaresensitivetocnerperipheralsolderbumpsthusitcanbeusedtoapproximatelylocatesolderbumpmissing.4.Vib

7、rationvelocityofsolderbumpswasalsosimulatedmeasured.Researchshowsthatvibrationvelocityofadefectivesolderbumpitsdeviationfactarebothgreatercomparedwithagoodsolderbump.Faperipheralsolderbumpifitsdeviationfactwasgreaterthan

8、0.45ithasbeenmissing.Fanareasolderbumpifitsdeviationfactmeasuredwaslowerthan0.3itisgoodifthedeviationfacthigherthan0.35ithasbeenmissing.thisinspectionmethodcanalsolocatedefectivesolderbumps.Therefethedefectinspectionmeth

9、odbasedonaircoupledultrasonicexcitationiseffectivetomeasurenaturalfrequencyofFCvibrationvelocityofsolderbumpsfdefectinspection.Keywds:defectinspectionflipchipnaturalfrequencyvibrationvelocityaircoupledultrasonicexcitatio