IntroductionIndium8.9HF-1isanairreflow,no-cleansolderpaste.Indium8.9HF-1offersunprecedentedstencilprinttransferefficiencytoworkinthebroadestrangeofprocesses.Inaddition,thehighprobetestabilityofIndium8.9HF-1minimizesfalsefailuresinICT.AlloysIndiumCorporationmanufactureslow-oxidesphericalpowdercomposedofavarietyofPb-freealloysthatcoverabroadrangeofmeltingtemperatures.ThisdocumentcoversType4andType3powderasstandardofferingswithSACalloys.Themetalpercentistheweightpercentofthesolderpowderinthesolderpasteandisdependentuponthepowdertypeandapplication.Standardproductofferingsaredetailedinthefollowingtable.Features•HighoxidationbarriertoeliminategrapingandHIPdefects•Highlyprobetestablefluxresidue•Halogen-freeperEN14582testmethod•Excellentprinttransferefficiencyon0.4mmpitchCSPsCompatibleProducts•ReworkFlux:TACFlux®089HF,TACFlux®020B•CoredWire:CW-807•W***eFlux:WF-9945,WF-9958Note:Otherproductsmaybeapplicable.Pleasec***ultoneofIndiumCorporation’sTechnicalSupportEngineers.CleaningIndium8.9HF-1isdesignedforno-cleanapplicati***,howeverthefluxcanberemovedifnecessarybyusingacommercially***ailablefluxresidueremover.StencilCleaningisbestperformedusingisopropylalcohol(IPA)asasolvent.Mostcommercially***ailablenon-water-basedstencilcleanersworkwell.PrintingStencilDesign:Electroformedandlasercut/electropolishedstencilsproducethebestprintingcharacteristicsamongstenciltypes.Stencilaperturedesignisacrucialstepinoptimizingtheprintprocess.Thefollowingareafewgeneralrecommendati***:•Discretecomponents—A10-20%reductionofstencilaperturehassignificantlyreducedoreliminatedtheoccurrenceofmid-chipsolderbeads.The“homeplate”designisacommonmethodforachievingthisreduction.•Finepitchcomponents—Asurfaceareareductionisrecommendedforaperturesof20milpitchandfiner.Thisreductionwillhelpminimizesolderballingandbridgingthatcanleadtoelectricalshorts.Theamountofreductionnecessaryisprocessdependent(5-15%iscommon).•Foroptimumtransferefficiencyandreleaseofthesolderpastefromthestencilapertures,industrystandardapertureandaspectratiosshouldbeadheredto.)