WLCSP--Bumping-Process-Flow

BumpingProcessFlowIntroductionStandardCSPProcessFlowUBMWafersiliconPassivationFinalmetalSputtertwolayer(Ti/Cu)UBMPatterntheUBMpadsandCuplatingFluxprintingandballplacementBallreflowPI+CSPprocessflowFinalmetalPassivationPIWafersiliconCoatingPIandpatternSputtertwolayer(Ti/Cu)underbumpmetallizationPatternUBMandCuplatingPrintingfluxandballplacementBallreflowSputterlayerRDL+CSPProcessFlow1stPIandpatternSputtertwolayerUBM(Ti/Cu)PatternandCuplatingBallPlacementandreflow2ndPIandpattern2ndPISputtertwolayerUBM(Ti/Cu)PatternandCuplating1stPIUBM/CuIncomingwaferinspectionFinalmetalpassivationsilicon1654232LayerCuCoilStructure(3P3M)silicon1stPIpassivation1stRepassivationSputtertwolayerUBM(Ti/Cu)PatternandCuplating2ndRepassivationSputtertwolayerUBM(Ti/Cu)PatternandCuplating3rdRepassivationSputtertwolayerUBM(Ti/Cu)PatternandCuplatingPrintingfluxandballplacement.ballplacementGoldBumpProcessFlowAuplatingIncomingwaferFinalmetalPassivationWafersiliconSputtertwolayer(TiW/Au)underbumpmetallizationSputterlayerPI+PillarProcessFlowFinalmetalPassivationPIWafersiliconSputterlayerCoatPIandpatternSputterUBM(underbumpmetallization)PlateCu/SnReflow