DEKProcessTheory培训.ppt

Guide Thetitleisaseriffontthatholdstheeyelonger thefontisGaramondBookCondensed60pt Thesizehasbeenchosensothattheeyewillgotothelogofirstandthendowntothemainheadingandthenthesubtitle Tokeepthebalanceoftheslidethisshouldalwaysbeasinglelinestatement Thesub title ifrequired isHelveticaMediumcondensed32pt asans seriftypefacethatiseasiertoreadinsmallersizes itisapproximatelyhalfthesizeofthemaintitlesowillnotfightforattentionbutwillbecomethenextelementthattheeyewillgoto ProcessTheory COPYRIGHT COPYRIGHTNOPARTOFTHISPRESENTATIONMAYBEREPRODUCED TRANSMITTEDINANYFORMORMEANS ELECTRONICALLYORMECHANICALLY INCLUDINGCOPYING PHOTOCOPYINGANDRECORDING FORANYPURPOSEWITHOUTTHEEXPRESSWRITTENPERMISSIONOFDEKPRINTINGMACHINESLTD PERSONALSAFETY BoardClampsareSHARPBrakesareHOTWearEyeProtectionandGloveswithSolventBasedProductsAlwaysfittheHEADPROPIfindoubtpresstheESTOPDoNotbypasstheCAMSAFES OBJECTIVE1 CourseGoal Understandthefundamentalsoftheprintingprocess includingknowledgeof SolderPaste Stencils Squeegees ToolingandBoard Attheendofthiscourseyouwillbeableto ENVIRONMENT ISTHEENVIRONMENTINCONTROL CONSTANTTEMPERATURE CONSTANTRELATIVEHUMIDITY HEARTBEATOFTHELINE ENSUREAREGULARFLOWOFPRODUCTSTHROUGHOUTTHELINE PRINTINGPROCESS PrintingProcess ThePurpose TheSurfaceMountAssemblyProcess ToprovideaconductingpathbetweentheboardandcomponentsthroughoutthedesignedlifeoftheproductThePrintingProcessToputtherightamountoftherightpasteintherightplaceattherighttime ThePerfectPrint CleanedgesFlatontopHeight StencilThicknessGoodAlignmentNoFluxBleed BasicStencilProcess PasteRolling Controlled PrintSpeed Even SqueegeePressure BasicStencilProcess BasicStencilProcess Boardisloweredundercontrolled SeparationSpeed Flood BasicScreenProcess Print BasicScreenProcess Finish BasicScreenProcess Hardware Software Environment Squeegees PrintSpeed Temperature Paste Humidity Stencil Pressure Tooling PrintGap Board FactorsAffectingthePrint SeparationSpeed MATERIALCHECKLIST STENCILSQUEEGEESPROFLOWPASTETOOLINGSOLVENT PAPERBOARDS STENCILS Stencils Withagoodstencil ExcellentresultsFewfailuresPredictableyields Withapoorstencil LotsofstencilwipingLotsofbridgesandO Cs Chemicaletching Chemicaletching Recessedetching Resultofamisalignedmillingset Lasercutting Trapezoidalaperture Step3 Step1 Step2 Step4 Difficulties HalfburntfiducialsRecess etching 1holeatatimeHence Hybridchemicaletch lasercutfinepitch Electroforming StencilSelection Chemical Etching Laser Cut Electro formed Hybrid Cost Costeffective Costeffective Expensive LessExpensive Accuracy OK Very Very Mixed Min Aperture size 0 2mm 0 4mmPitch NoLimit NoLimit NoLimit ApertureShape Material StainlessSteel Brass StainlessSteel NickelAlloy StainlessSteel Brass Fiducials Good Good Weak Good StencilDesign Pitch mm Thou mm Thou mm Thou 1 25 50 0 25 0 5 10 20 0 15 6 0 625 25 0 25 0 3 10 12 0 15 6 0 5 20 0 225 0 275 9 11 0 15 6 0 4 16 0 175 0 2 7 8 0 10 4 0 3 12 0 1 0 15 4 6 0 065 3 ApertureWidth StencilThickness StencilDesign Pitch Length Width DesignStencilAperturestoallowaclearanceofatleast50 mbetweenPasteandedgeofPad Paste Pad StencilDesign ReleaseEquation1ReleaseEquation2WTPasteReleaseEquationWAvg Particlesize 0 66 1 5 5 L W2 L W T StencilDesign ApertureDesign ForProFlow Largeapertures 5mm shouldbebarredAperturesshouldbemorethan5mmfromboardclampfoilsLargeaperturescanresultinpastebeingdraggedfromtheleadingedgeofthepastedeposit 739mm 29 739mm 29 622mm 265 EdgeJustified 265 CentreJustified 739mm 29 739mm 29 368 3mm 368 3mm CenterPoint StencilCleaning Manual UseaLintfreeClothWithasolventsoakedclothineachhandcleanbothsidessimultaneously WearGloves ScreenCleanMachineUnderScreencleaner Programtocleanasseldomaspossible UseVacuumtoclearblockedaperturesAlwaysfollowawetwipewithadrywipe Solvent Paper SOLVENT DISOLVESTHEPASTECANBEWIPEDOFFEVAPORATESQUICKLYLEAVESNORESIDUEDOESNOTHARMTHEUSCHOSESANDWIPERBLADESPAPER ABSORBENTLINTFREE StencilMaintenance Remember StencilsareFragile StoreandHandleWithCareKeepStencilsCleanInspectforDamageandStretchRepairFiducialswhenDamaged Stencil Boardalignment Cause PoorArtworkPoorQualityStencilManufacturePoorboardmanufacturingBoardStretchPoorFiducialAlignmentMachinenotcalibratedSolution PrintOffsetsBuyNewStencilImproveFiducialScoreBuybetterboardsCalibratemachine Conclusions Bettertohaveexcellentlow techstencilthanpoorhigh techstencil Experiment especiallywhenchangingtechnology Correctstencildimensionsarevitalinordertoachievegoodprints Agreatmachinecandolittletocorrectafundamentallyflawedstencil OBJECTIVE6 SOLDERPASTE SolderPaste WhatisSolderPaste Alloy solderpowder FluxGellingAgents 100 100 50 Solderbyvolume 90 SolderbyWeight 50 10 SolderPaste ReadtheLabel Harmful ProductCode SN63RP11AGS90 FASTPRINTROSINSOLDERCREAM Comp SN63Pb37 Flux NC SMQ51SC Batch 0270782 Contents 500g UseBy 21 05 99 SolderPaste ReadtheLabel ProductCode SN63RP11AGS90 FASTPRINTROSINSOLDERCREAM AlloyType63 Tin 37 Lead or35 lead 2 Silver FluxMediumType RosinProduct MetalContent90 byweight EutecticDiagram Puretinmeltsat450degreesPureLeadmeltsat620degrees SolderPowder Type2Powder Type3Powder Consistentalloy particlesizeandparticleshape Oxidefree IPCPowderSpecification Type3isthetypicalsizeforcurrentSMT Byweightofsample Type NoneLarger than Lessthan1 Largerthan 80 minimum between 10 maximum lessthan 2 80 m m 75 m m 75to45 m m 20 m m 3 50 m m 45 m m 45to25 m m 20 m m 4 40 m m 38 m m 38to20 m m 20 m m Thesmallertheparticlesizethebettertheprintdefinitionbutthemoreexpensivethepastewillbeandthegreaterchanceofreflowproblems Ruleofthumb keepaminimumof5particlesperaperturewidth Stencil Board ParticleSize WhatdoestheFluxdo FluxensuressuccessfulsolderjointisformedbetweencomponentandpadSuspendsthepowderProvidescorrectrheologyandtackinessCleanssurfaceRemovesoxidefromsolderpowderProtectssurfaceLeavessaferesidues Whataregellingagents Makesthefluxpseudoplastic S 1 Pasteviscositymovesupanddownthisplotdependingonwhereitisintheprintprocess newtonic Shearrate energy Viscosity Temperaturev viscosity Maybe forlessthan3months Definitelyfor3 6months hmmmm Never PasteStorage UsingthePaste ColdStorage WorkingPot Printer FreshPaste After8Hours EndofRun ExtendedDowntime EndofDay Disposal Returnonlyifpastequalityisgoodanditmakeseconomicsense TemporaryPot GoodWorkingPractices StirPasteGentlyBeforeUseRegulatePasteDiameterat15mmPerformSmallTop UpsRegularlyRegulateTemperatureandHumidityDoNotLeavePastedryingonStencil OBJECTIVE7 SQUEEGEES Squeegees Squeegees Transfer Drivingforcesareinfluencedby SqueegeeanglePrintspeedPasterheologyPasterollvolume Drivingforce Transferforce SqueegeePrinciples Reactionforce Squeegeeforce SqueegeePrinciples Pasterolling Streamlines Shearratechangeswithpositionofpasteinroll Lowershearrates Highershearrates Angle 45 60 IntrusivereflowHighspeedprintingPrintingthickstencilsPrintingGluePrintingmeshscreens StandardSMTPrinting IncreasedForce ReduceForce AngleChanges Note Anaveragesqueegeemaytravel5 6milesinitslifetime Andthat sacrossaroughsurfaceandunderpressure EffectofSqueegeeWear PasteDeflectors Usedtopreventtramlines Helpsmaintainpasteingoodcondition Maintainsaconstanttransferintothroughholesforintrusivereflowinpasteapplications PasteDeflectors Squeegeematerialselection Hardpolyurethane 95Shore Excellentfine goodcoarsepitch robust butmustbestraightRigidpolyurethane 120Shore OnlyfortotallyflatboardsSoftpolyurethane 80Shore OnlyforscreenprintingMetalExcellentcoarseandfinepitch couldbedamaging Material Polyurethane Squeegeeforce polyurethaneSqueegee Stencil ScavengedPaste PCB Ridge CompressedBlade Polyurethane Shore65 85 DekGreen TooFlexibleforstencilprinting usedonlyinmeshapplicationsShore95 DekRed Willneedreplacingorregrindingafter25000prints Essentialtocontrolsqueegeepressuretoreducescooping Causeslittledamage CommonlyusedinSMT Clampedandbondedsqueegees HardpolyurethaneSqueegees Hardestpolyurethanesqueegees Material Metal Composite Squeegeeforce Metal CompositeSqueegee Stencil Paste PCB DamagedBlade Ridge Metal Shore 200EasytodamageExpensiveHighpressuremaycauseBridgingPasteheighthigherthanstencilthicknessBetterprintqualityWiderprocesswindowforpressureHighpressurewillnotcauseScooping Metalsqueegees Metalsqueegees Overhang 15mm widelyused reducedriskofstencil bladedamageduetoincreasedflexibility 6mm historicallyusedbutnolongerrecommendduetoincreasedriskofstencil bladedamage Composite Shore120 Composite VeryRigidUnevenboardscausedamagetoStencilandBladesUsedinapplicationswhereverylargeaperturesareused Widerprocesswindowforpressure Compositesqueegees Property Metal Polyurethane Finepitch Good Excellent Largeapertures Excellent Good Pressureeffect Doesnotcausescooping Needscontrol Damageresistance Poor Good Damagetostencil Poor Good Life Untilbroken 25 000 PasteHeight StencilThickness StencilThickness MetalVPolyurethane Length Choosetheclosestlengthtotheboardsize Board Squeegees Paste DryPaste Gap EffectofExcessPressure PrintDirection ApertureScooped Pads Board stencil Scooping Squeegees METALSQUEEGEESPOLYURETHANESQUEEGEESRIGHTLENGTHRIGHTHARDNESS OVERHANGformetal ANGLENOTDAMAGEDNOTWORN OBJECTIVE8 TOOLING Tooling Tooling MagneticPillarsDedicatedManuflexVacuflexF P AFormflexToolingproblems Solutions 19mmand4mmPinDiameterSimpleandRobustConstructionInexpensive Table Rail Rail MagneticTooling Canprovide100 supportCancontainmilledoutareasforundersidecomponentsCanbefittedwithvacuumcups DedicatedToolingPlatewithMilledoutareas DedicatedToolingPlateproviding100 support DedicatedToolingPlates Dedicatedtooling 3mmPinDiameter11mmPinspacingMax BoardSize254x254mm Manuflex IdealSolutionforFlexiCircuitsIdealforCeramic SiliconSubstratesVacuumtoolingplatesQuickChangeover3 1mmDiameterPinsMaximumBoardSize254x368mm Multiflex FinePitchAutoflex 1800PinsIndividuallyPneumaticallycontrolled4mmPinDiameterwith2mmEnds11mmSpacingMax BoardSize508x508mm F P A Formflex Completesupportfor BoardStencilComponentProflowTM BoardLiftedByToolingcausing BoardDamageSqueegeePressureProblemsUnevenPasteHeightsDirtyStencil ToolingProblems Table Rail Rail Cleantabletopofsolderpaste debrisKeeptoolingpinscleanReplaceworntransportbeltsBecarefulnottomixdifferentletteredpins Autoflexonly Ensureundersideofboardisflatandclearoflabels soldermasketc Removeormovethepin Solutions excess insufficient insufficient 1worn printdirection printdirection support support support squeegee OtherToolingProblems Tooling TOOLINGTYPE MAGNETIC AUTOFLEX DEDICATEDTOOLING VACUFLEX MANUFLEXCLEANTOOLING TABLECORRECTPOSITIONOFTHETOOLINGPROFLOW STENCILSUPPORT OBJECTIVE10 BOARDS Boards UnevenPadsurfacecancauselossofgasketsealresultinginbridgingetc Iftheresistishigherthatthepadthegasketsealwillbelostresultinginbridgingetc Theboarddesigncanimpingeontheeffectivenessandqualityoftheprintprocess Herearesomethingstolookoutfor Padwithunevensurfacecoating Pad Resist BoardIssues Undersidecomponentscanrestricttheuseoftoolingpins usetoolingplateorFPALargeundersidecomponentsmayimpedeboardtransport increaseunderclearance Theboarddesigncanimpingeontheeffectivenessandqualityoftheprintprocess Herearesomethingstolookoutfor BoardIssues ViaholescancauseproblemswithvacuumtoolingLabels barcodestickersetc increaseboardthicknessleadingtotooling printandpressureproblems Theboarddesigncanimpingeontheeffectivenessandqualityoftheprintprocess Herearesomethingstolookoutfor Testedok BoardIssues Boardswithtaperedorchamferededgesaredifficulttoclampandmaybeliabletomovementduringprintleadingtorandomoffsets BoardIssues Boardconsiderations PadsurfaceHASLGoldonnickelOrganiccoatingResistThinnerthanpadsClearoffiducials Etc SizeUndersidecomponentsObstructions barcodesetcFiducialsandholes FibresthesecanblockstencilaperturesOldSolderthiscancausesolderballsFingerprintsthesecancorrodepads tracksetchandleboardbyedges wearglovesUseCM20 Ensurethatproductionboardsarefreeof BoardIssues In lineboardcleaner UNEVENPADSURFACESOLDERRESISTTOOHIGHUNDERSIDECOMPONENTSRESTRICTSTOOLINGVIAHOLESWITHVACUUMTOOLINGBARCODELABLES Boards Boards CHAMFEREDEDGESDIRTYBOARDS FIBRESFROMPRODUCTIONOLDSOLDERFINGERPRINTSBOARDACCURACYFIDUCIALQUALITYBOARDWARPANDSTRETCH OBJECTIVE11 TROUBLESHOOTING Troubleshooting Bridging BridgingCauses NoaperturereductionSolderresisthigherthanthepadsAreaclosetoobstruction boardclamp label etc Board stencilmisalignedUnevenhaslfinishStencildamagedSqueegeepressure ProflowpistonpressuretoohighSqueegeeworn Incompleteprint Incompleteprint PasteviscositytoohighDrieduppasteinProflowheadDirtystencil toomuchapertureblockageNotenoughpasteonthestencilPrintspeedtoohighProflowpistonpressuretoolowWetstencilaftercleaningWetordirtyboardsStencilaperturestoosmallinrelationtothestencilthicknessNostencilsupportwithProflowS