Abstract
Inrecentyears,chipscalepackage(CSP)technologyhasbroaddevelopmentprospectsin
thefieldofelectronicpackagingduetoitsadvantagesofminiaturization,high-density
integrationandhigh-performanceconnection.InCSPtechnology,solderballscanbeusednot
onlytoconnectchipsandsubstrates,butalsotointerconnectsignalswithinthechip.Whenthe
solderballisusedtoconnectthechipandthesubstrate,therequiredparticlesizerangeis
0.2~0.8mm,andwhenthesolderballisusedtointerconnectthechip,therequiredsolderball
particlesizeislessthan0.2mm.
Inthispaper,adeviceplatformfortheproductionofsolderballsabove0.2mmand
uniformdropletsbelow0.2mm,andavisualinspectionplatformforsolderballsweredesigned
andbuilt.Thesolderballanddropletproductionplatformincludesthedesignofthemaindevice
andtheconstructionofauxiliarysystems;Thesolderballinspectionplatformconsistsof
hardwaresystemssuchasindustrialcameras,lenses,lightsourcesandcomputers,aswellas
softwaresystems.
BasedontheelectromagneticforcetechnologybytheCIJ,threespecificationsofsolder
ballsof0.39mm,0.56mmand0.75mmwereproduced,andtheinfluencingfactorsofsolder
ballformingwereanalyzed,andthenozzleaperturewasthemainconditionaffectingthe
particlesizeofthesolderballs,theamplitudeandfrequencyoftheinputcurrentwerethe
decisiveconditionsaffectingwhetherthejetcouldbebrokenintouniformsolderballs,andthe
freeliquidsurfaceairpressureonlyaffectedthejetvelocity.Thekeytechnologyforthe
productionofuniformdropletsbelow0.2mmwasstudied,whichinvolvedthecombinationof
electromagneticforcet