《電子信息專業(yè)英語》課件 Lesson 6 The Package Technology of IC

Lesson6ThePackageTechnologyofICKeywords

■Assembly[?’sembli]

裝配

■DieSeparation分片■Leadframe

引線框架■Eutecticattach[ju:

’tektik]

共晶焊粘貼■

Ultrasonicbonding超聲鍵合■Backgrind背面減薄■WireBonding引線鍵合■Epoxyattach[e’p’ksi]

環(huán)氧樹脂粘貼■Glassfritattach

玻璃焊料粘貼■Ceramicpacking[si’r?mik]陶瓷封裝■Plasticpacking塑料封裝■Thermocompressionbonding[’θ?:m?u’k?m’pre’?n]熱壓引線鍵合■Thermosonicballbonding熱超聲球鍵合■工作任務(wù)：芯片是怎樣被封裝的？

■學(xué)習(xí)目標(biāo)：掌握裝配與封裝的基礎(chǔ)知識(shí)，包括集成電路封裝的功能、傳統(tǒng)的裝配與封裝的步驟、封裝的種類等，并掌握基本術(shù)語。

■重點(diǎn)難點(diǎn)：集成電路的封裝設(shè)計(jì)

■推薦學(xué)時(shí)：6學(xué)時(shí)工作任務(wù)：

HowtheIntegratedCircuitsarepackaged?

IntroductionTraditionalAssembly

ICfinalassemblyconsistsoffoursteps:backgrind,dieseparation,dieattachandwirebonding.Backgrindreducesthewaferthicknesstotheappropriatedimension.Dieseparationcutseachdiefromthewafer,asshowninFig6-2.Dieattachisthephysicalattachmentofthedietotheleadframeorsubstrate.Wirebondingattachesfine-diameterwiresbetweendiebondingpadsandtheterminalsoftheleadframetoformelectricalconnections.Dieattachisdonebyepoxyattach,eutecticattachandglassfritattach.Thecommonepoxyattachmethodbondsthechiptotheleadframeusingepoxy,asshowninFig6-3Eutecticattach,commonforbipolarICs,usesathinfilmofgoldonthebacksideofthewaferthatisalloyedwiththemetalizedsurfaceoftheleadframe,asshowninFig6-5Glassfritattachusesamixtureofsilverandglassinanorganicmediumtoattachchipsinaceramicpackage.Thethreebasictypesofwirebondingare:thermocompressionbonding,ultrasonicbondingandthermosonicballbonding,asshowninFig6-6、Fig6-7、Fig6-8.Thermalenergyandpressureareusedinthermocompressionbonding.Ultrasonicbondingisbasedonultrasonicenergyandpressuretoformawedgebondbetweenthewireandpad.Thermosonicballbondingcombinesultrasonicenergy,heatandpressuretoformaballbond.TraditionalICpackagingmaterialsareplasticpackingandceramicpackaging.Plasticpackingusesanepoxypolymertoencapsulatethewirebondeddieandleadframe.Thistechnologyhasmanydifferenttypesofplasticpackages.Ceramicpackingisusedforstate-of-theartICpackagesthatrequireeithermaximumreliabilityorhigh-power.Thetwomaintypesofceramicpackagingareeitherarefractory(hightemperature)ceramic,asshowninFig6-10,orceramicDIP(CERDIP)technology.Bothhaveahermeticseal(sealedagainstmoisture).AllassembledandpackagedchipsundergoafinalelectricaltestforICreliability.AdvancedAssemblyandPackagingNewpackagingdesignsarebeingintroducedtoprovideformorereliable,fasterandhigher-densitycircuitsatlowercost.Advancedpackagingdesignsinclude:FlipchipBallgridarray(BGA)Chiponboard(COB)Tapeautomatedbonding(TAB)Multichipmodules(MCM)Chipscalepackaging(CSP)Wafer-levelpackagingFlipchippackagingmountstheactivesideofachiptowardthesubstrate,Itusesbumptechnology(typicallysolderbumps)toformtheinterconnectionbetweenthechipandsubstrate.Anepoxyunderfillisusedaroundthearea-arrayofbumpstoimprovereliability,asshowninFig6-11.Ballgridarray(BGA)usesaceramicorplasticsubstratewithanareaarrayofsolderballstoconnectthesubstratetothecircuitboard.，asshowninFig6-12.Tolowercosts,thistechnologyisreadilyintegratedintostandardsurfacemountassembly.Chiponboard(COB)mountsICchipsdirectlytothesubstrate,alongsideothersurfacemount(SMT)orpin-in-hole(PIH)components,asshowninFig6-13.Tapeautomatedbonding(TAB)usesaplastictapeasachipcarrier.Thetapehasathincopperfoilthatisetchedtoformtheleads.Thechipandleadsareremovedfromthecarrierpriortoassemblyontothecircuitboard,asshowninFig6-12.Multichipmodule(MCM)hasseveraldieassembledontoonesubstrate.Thispermitsahigherdensityofchips,asshowninFig6-15.Chipscalepackaging(CSP)hasanICpackagethatisaboutthesamesizeasthesiliconchip(＜1.2timesthefootprintofthedie).Thisisafastgrowingmethodofadvancedpackaging,andprovidesforlowercost,lowerweightandlowerthickness.Wafer-levelpackagingplacesthe1stlevelinterconnectionsandpackageinput/outputterminalsonthewaferbeforeitisdiced.Itistypicallydonewitha