PCBA可制造性设计规范.ppt

SMTPCB Panellayout SMTTeam2015 03 22 PCBDesignGuideline Revisionrecord Purpose Basedontherequirementsofproductionprocess Inthelayoutandcircuitboarddesignprocess Thereisastandardtofollow Toachievehighefficiencyintheproductionofassembly Easyassembly lowcost andhighqualitytarget Thecontentisonlyapplicabletotherelateddatabase someareforreferenceonly content PCBlayoutrulesTextmarkingforsilkscreenlayerPCBFiducialMarkdesignPCBfixedpositionholeSMTcomponentPADdesignPTHcomponentPADdesignThrough hole Via designTracedesignotherlimitation PCBlayoutrules V Cutlayoutrule ChipstoV Cutlineshouldbemorethan1mm otherwisewilldamagechipsorwillchangetouseStampCutdesign willaddthePCBcostThedistancetoPCBedge0 5mm cannotlayoutthetrace ThedistancetoPCBedge1 0mm cannotlayouttheanycomponentThedistancetoPCBedge5mm cannotlayoutthecomponentsheightover25mm otherwisecuterwilldamagecomponents PCBlayoutrules V Cutlayoutrules PCBtracetoV CutshouldbemorethenS 0 5mmsafetybuffer otherwisewillhavetherisktodamagethetrace WhenweuseV CutPCBthickness1 0mmto3mm 1 0mmto0 5mm SMTpallet PCBoutlineissquaretypeorrectangletype irregularshapecannotusetheV Cut irregularshape PCBlayoutrules Stampdesign StampdesignonlyforirregularPCB PCBtoPCBlayoutdistanceis2mm V Cutonly0 3mmStampdesignparameters PCBlayoutrules V CutVSStamplayout PCStoPCSdistanceonly0 3mmforV Cut wecansavethePCBlayoutcostStampCutdesign PCBPCStoPCSdistanceis2mmBaseonsamePCSdesignwithdifferentCuttype stamp V Cut thePCBcostwillimpact10 25 V CutPCBwillbecutbymachine butStampCutwillbrokenbyOPandhavestressthendamagethecomponents V Cutmachine PCB panellayout Whydon tchoosesinglePCBforSMTprocess WeneedtoputtheeachsinglePCBoncarrierwhendoSMTprocessButcarriercaveandsinglePCBhavetolerance soalwayshappensolderpasteprintingmisalignmentthenwillgettheshift tombstoneprocessissueSometimeswillhappensinglePCBliftupfromSMTcarrierandwillhavethechipsmountingshift missingprocessissues PutthesinglePCBonthecarrier PCB panellayout FactorsofimpactPCBCostPCBlayoutFinepitchcomponentsPanelV Cut StampCut PCBconveyoredgesizePCBdrillholesize quantityPCBmaterialcostPCBprocesseasy complicated processspecPCBsurfacefinishedprocessalsoimpactcost OSP IMS EING IMTPCBoutline regularshapeischeaperthanirregularshape Textmarkingforsilklayer Thecurrentsituation WereceivedthegerberUKdesignteam nosilklayerbefoundWecannotdirectlyconfirmPolarityofcomponentonthePCB cannotconfirmthelocationofcomponent easilytoconfirmICshiftornot IntheproductionadjustmentX Ycoordinateandconfirmationthelocationcompletelyrelyonengineeringdrawings Bigwasteoftime Nosilklayersinthegerberfile Notextmarkonthepcb Textmarkingforsilklayer Astheicontextmarkingdesignwecanaccept Wecanquicklyinspectionlocationwherethereareproblems silkscreen Textmarking Textmarkingforsilklayer Componentoutline polaritymarkingdesigndefinition Textmarking keepawayfromViaHoleorThroughHoleasfaraspossibleTextmarking Silkscreenprintingcharacter polarityandpolaritysignscannotcomponentsbecoveredTextheight 25mil linewidth 5milBesidetheBGA CSP componentoutlineshouldnotsmallerthanactualcomponentsize ThetextdoesnotoverlapSMD PTHcomponenttextmarkingincludebodyoutline pinassignment componentname polaritymarking asbelow Componentoutline polaritymarkingTantalumcapacitorordiode 3PIN b SOP SSOP c QFP Textmarkingforsilklayer Componentoutline polaritymarkingd QFNe BGA CSPmarking outlinesizemustthesameasactualcomponent Textmarkingforsilklayer PCBnumberandversion i PCBModel ii PCBPartnumberandversion iii textheight 80milPCB板號說明如下 西元年度後兩碼 06 07 全新PCB必需附予板號及 SA SampleA 版本 爾後修改版本依序為 SB SC 或 1A 1B 1C 等 量產時版本必需為 1 2 3等 Textmarkingforsilklayer PCBFiducialMarkdesign Thecurrentsituation Manyprojectsdidnotdesignfiducialmark in themachinecannotrecognizetoposition causenohighprecisionprint mounted PCBFiducialMarkdesign L Threefiducialmark outlocateddiagonallyonboard anddofollowrelateddimensionrequirement fiducialmarkdimensionis1mm d andsoldermaskis3mm D Thediagonalfiducialmarkshouldnotbesymmetrical itshouldbekeepawayat5mm FiducialPADedgekeep4mmdistancefromtheedgeofPCBSingleboardmusthavetwofiducialmark inlocateddiagonallyontheboard Markout Markin PCBfixedpositionhole Toolingholesonallboardsarecalledoutwithcorrectdimensions tolerances andarenon plated 3 55mm 0 075 0or2 18mm 0 05 0 05 Thereshouldbe3 81mmarclocatedat4cornersofPCBtoavoidstuckatconveyoranddamageofpackingmaterial Uniformfixedholesizeandconvenienttoolforpositioning Toolingholes 3 81mmarc NGsymptom 0402chiptombstoneForexample D500 FN700054chip0402chiptombstonedefectrate 1 0 NGpicture Analysis PADtoPADspaceistoobigcausedthetombstoneafterIR PADtoPAD 16mil PADtoPAD 22mil SMTcomponentPADdesign SMTcomponentPADdesign NonspecificationswithinRLCPaddesignaccordingtothefollowingprinciples i B maxofW1 topreventtheshift ii C 10 H electrodewidth 15mil iv restrictedareaL2 A 10mil W2 max W1 8 maxoftolerance B 10 1 Resistanceandinductancecomponentssizelist 0201PADdesign 0402PADdesign Note besidesthechip0201 0402 therestofdatabaseisforreferenceonly unit mil SMTcomponentPADdesign 2 capacitancecomponentsizelist Note besidesthechip0201 0402 therestisforreferenceonly unit mil SMTcomponentPADdesign SMTcomponentPADdesign 3 STC3216 7343 unit mil Note Nochipscomponentthatsizebelow0603locatedbeside7347and6032tantalumcapacitorwithin2 6mmpadtopaddistance Ifun avoidable thechipcomponentsshouldbeverticalwiththetantalumcapacitor unit mm 4 Electrolysiscapacitorpartssizelist SMTcomponentPADdesign 5 Diode 3PIN unit mil SMTcomponentPADdesign 6 ConnectorpinforSingleside unit mil SMTcomponentPADdesign 7 Connectorpinfortwoside unit mil SMTcomponentPADdesign 8 ICtypesa SSOP SOP unit mil SMTcomponentPADdesign 8 ICtypesb QFP unit mil SMTcomponentPADdesign ICtypes 9 QFN unit mil SMTcomponentPADdesign BGA CSP unit mil SMTcomponentPADdesign PTHcomponentPADdesign Inordertosimplifyandimprovetheprintingcircuitwelding soldering process Thespecialdevelopmentofthrough holereflowtechnology Pin in Paste Thethrough holetypeconnectorfromDippingprocess changetoSMTprintingsolderpasteandreflowreplaced Placeallthru holepartsontopsideoftheboard Avoidmanualsolderingprocess B aperturesize pindiametersize 0 25mm 10mil A Theouterlayeroftheminimumpadsize aperturesize 0 36mm 14mil Accordingtothemanualsolderingparts Padsize A Holesize B 40mil PTHdesignguidelinePartsofpindiameterandthroughtheapertureratio PH principle Pintoholerate P H shouldfallwithin0 6 0 8 shownasdiagram PH 0 6 0 8thebest PH 0 4 0 5Acceptable PH 0 3notacceptable PTHcomponentPADdesign IfanyannularringofPTHconnectwithconnectororPTHpad pleaseaddsoldermasktoisolateeachother width20milatleast AsPSUA000116Designissue betweenPADwithGroundnosoldermaskcoveredcausethesolderbridge emptysolder PTHcomponentPADdesign PTHrestrictedzone Forpininpasteprocess keepatleast3mmdistancebetweenedgeofholeringandpad ThedistancebetweenthePTHandchipstooisveryclosewhenmanualsolderhastheriskforbrokenandsoldershort besidesarrangeOpstomanualsolder nochoice Wastealotofmanpoweranddelayoutput PTHcomponentPADdesign Through hole Via design ViaholeunderthecomponentbodyViaholeunderthesmtcomponentbody needtoconfirmthisPCBwhetherthroughwavesolderingprocess ifso needtoblindandburiedviahole Otherwise therewillbetheriskofoverflowfromtheholeofViasolder 1 ThenormalPADlayout WithinthePADpins Innerbandarea 10mil ViaHolecannotbeplaced outlinebandarea 10mil ViaHolecannotbeplaced Viaholeunderthecomponentbody 2 Un normalPADlayout thepinofthecomponentoverthePAD innerbandarea A 10mil ViaHolecannotbeplaced outlinebandarea 10mil ViaHolecannotbeplaced Through hole Via design Tracedesign PowerTracetostrengthenPAD ViaholewithTracetojunctionneedtostrengthen thegeneralway PowerTrace therestoftyperefertoTeardropdesign Tracedesign AddteardropIntheoutertraceaddteardropasbelowicon 1 Whenthelinewidthislessthan8mil Inpadandtracejunctionwithwidthof8milandlengthof6miltrace 2 Whenthelinewidthismorethan8min donotaddTearDrop 3 IfthedistanceisnotenoughtoaddaTearDrop canbeignored Tracedesign Keepsymmetrictracedesign Traceleadtheway Tracefromthecenterofthepad trace PAD Tracedesign Tracelineandthehole berecommendedinthefollowing Otherlimitation ComponentplacementlimitationBoardedgepartsrestriction includingtheprocessedgesize i InSMTstage thereshouldbenoanycomponentbodyorpadwithin4mmalongpcbedgethatusedforconveyortransfer asbelowtheupperandthelowersides Within2mmfrompcbedgethatverticaltotheconveyor PIPorPTHcomponentbodyshouldnotoutofpcbedge ComponentplacementlimitationBoardedgepartsrestriction includingtheprocessedgesize ii InSMTstage thecomponentheightshouldlowerthan2mmwhenitawayfrompcbedge4 6mm indicatedinpinkcolorregion Otherlimitation DeformationlimitB A 7 5 1000 andthemaximumdeformationofBmustbelessthan1 2mmPCBthicknesslimit 1 1 6 0 127mmor10 PCBsubstanceselectionThepcbprepregshouldmeetcriteriaofTg 145 ThepcbprepregshouldmeetcriteriaofTd 320 Otherlimitation PIPpartslimitAllofthethroughholepartmustbedesignedinsecondtoavoidtheuseofhandsolderingprocessThefirstsurfaceisnecessarytousetheSMDTYPEpartorthroughholepartspinandpartsbodycannotoutstandPCBsecondsurfaceThespecofpinoutofpcbsurfaceinPIPprocess pinlength PCBthickness 0 3 0 6mmTheinsertpartsinPCBcannottilt dumpingoreasytoloosestate Otherlimitation Otherlimitation Choosethecomponent TheuseofchipcomponentsintheSMTstageasfaraspossible reduce