PCB行业HDI制程表面处理方式发展趋势.pdf

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1、HDIPCBHDIPCBSurfaceSurfaceFinishesFinishesandTechnologyTrendandTechnologyTrendJul,20101PCBFabricationProcessFlowPCBFabricationProcessFlowInnerlayerInnerlayerRemoveRemoveResistResistEtchEtchResistResistOxideOxideLaminateLaminateTinTinCopperCopperPlatingPlatingDesmear/Desmear/PlatePlatePlatePlateR

2、esistResistPTHPTHDrillDrillRemoveRemoveSolderSolderResistResistEtchEtchTinStripTinStripMaskMaskSurfaceSurfaceFinishFinish2SurfaceFinishWhyneedSurfaceWhyneedSurfaceFinish?Finish?3SurfaceFinishSolderingWirebondContact4SurfaceFinishFunctionforSurfaceFinish•PreventCopperCircuitsfromOxidizing•Platfor

3、mforMechanicalJointwithSolderandComponent•ProvideforElectricalPathbetweenCircuitryandComponents5SurfaceFinishTypesofSurfaceFinishTypeProcessCoatingmodeHotAirSolderLeveling(HASL)DipElectrolyticNi/AuElectroplatingImmersionSilver(ImAg)MetallicImmersionTin(ImSn)Chemicalreaction(Galvanicdisplacement&

4、ElectrolessNickel/ImmersionGold(ENIG)Reductionreaction)ElectrolessNickel/ElectrolessPalladium/ImmersionGold(ENEPIG)OrganicSolderabilityPreservative(OSP)DipOrganicCarboninkScreenprint6SurfaceFinishSurfaceFinishselectionProductrequirementSurfacefinishLegislationLeadfreerequirementComponentplacemen

5、tCo-planarity&costApplicationenvironmentChemicalresistanceContactapplicationContactresistance&wearresistanceWirebondAlorAuwirebondrequirementMultipleassemblyComplexfinish7SurfaceFinishSurfaceFinishFavorOSPImAgImSnSHIKOKU8HASLHASL9HASL
HASL-GeneralProcessFlowMicro-etchingFluxHASLPostcleanPCBImmer

6、sionWithdrawalAirknivesSolderPot10LF-HASLAdvantagesofHASLinassemblysoldering:1.SoldertosolderconnectionbetweenPCB&componentinreflowsoldering&wavesoldering2.Longershelflifethanothersurfacefinishes3.Cu-Snsolderjoint4.Goodsolderabilityafterseveralreflows5.Goodelectricaltestperformanceaftersoldering

7、11LF-HASLDisadvantagesofLead-freeHASL1.HighestworkingtemperatureofallLead-freesurfacefinishesSurfaceFinishHASLENIGOSPIm-AgIm-SnWorkingtemp.>260oC85oC40oC50oC70oC2.Themechanicalpropertiesoftheboardmaybedamagedbythermalimpacto