无铅组装工艺实践指南(1)

1SMT2SMT23SMT--4BGA35SMT--6TimeTemp.200C250Ctc1–smallSMDtc1–mediumSMDtc3–largeSMD50C50CPeak:200–250C47TimeTemp.230C250Ctc1–smallSMDtc1–mediumSMDtc3–largeSMD20C20CTooHot!TooCold!Peak:230–250C859—(seconds)C3090230240250217260245245CBGASAC230CPCBÆÅ22810W/S—PCBSn63Pb37Sn3.0Ag0.5Cu24552605PCBENIGAgOSP611W/SzzzVoc-freez12W/SzSAC713W/S1.02.0Sn63Pb37Sn99.3Cu0.7SAC14W/Sz¾PCBENIGAg¾OSPSACVoc-free;¾815zMIL-STD/IPCz40C25z60/40228(188)zSn3.8Ag0.7Cu257(217)zSn0.7Cu267(227)160501001502002503003500123456JointFormationFluxActivationPhaseChange917050100150200250300350012345678TheoreticalActualMeltingPoint.217CThermalEnergy=AreaUnderCurveVs18101935S@37035S@34035S@340HAKKO9362035S@37035S@34035S@340ERSA20001121-z—z22BGAZoneTinLeadLeadFreeTempTimeTempTimePre-Heat100C-120C.60-90s130C-140C.100sSoak160C-170C.90s140C-170C.90sRampNONE170C-225C.100sReflowMax220C.60s225C-235C.15-30sCool60C.30-60s60C.30-60s1223BGA250C!!235CPCB190C24BGA¾¾10CTempDelta13255deg.∆5°cPCB10240250CBGA26∆∆∆∆∆∆10CBGA1427PrintingonPBGA&µBgaSolderpastedepositiononPBGASolderpastedepositiononIntelµBGABGA/CSP28BGASMT1529SOPSMT30SOP163132zIPCA610CzzOSP1733zFilletLengthQFPSPCPinLengthzQFPQFPHeel/Center/Toe/FilletzOpenOpenSignalzJAXIXrayAXISOPQFP34AOI--zAOIAOIAOI1835AOI--zSOPChipSMT36AOI--zAOIOMRONAOI“LANDTIP”“DOMETIP”AGILENTAOIzAGILENTAOIOMRONAOIzPCBOSPPCBAOIPCBOMRONAOI“DOMETIP”AGILENTAOI“JOINTINSPECTION”1937