表面贴装片式元器件-仅有底部端子焊料空洞可接受标准?

IPC-A-610E
1.表面贴装片式元器件-仅有底部端子:未规范焊料空洞可接受标准
2.表面贴装数组:有规范焊料空洞可接受标准,在X射线的影像区内,任何焊料球的空洞等于或小于25%。

业界表面贴装片式元器件-仅有底部端子焊料空洞可接受标准,谁可分享?
Intel/Dell/IBM/Apple…国际大厂表面贴装片式元器件-仅有底部端子焊料空洞可接受标准,谁可分享?

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可靠性技术新手提问

接地试验

2012-8-8 20:32:12

可靠性技术可靠性设计

可靠性预计中IC类的门数与晶体管数各位有无估算的经验?谢谢

2012-8-9 12:02:09

3 条回复 A文章作者 M管理员
  1. yeh

    Forvoidpass/failcriteriaforSMDcomponents(exceptforareaarraydefinedinIPC610E8.3.12),youcanrefertotheinformationbelow:

    Phil
    WelcometoBoardTalk.WearetheAssemblyBrothers,PhilZarrowandJimHallofITMConsulting,we’reheretoansweryourquestionsonSMTprocesses,equipment,materials,andprocedures.Whatisinourmailbagtoday,Jim?

    Jim
    TodaywehearfromHM.”IknowaboutvoidsinBGAsolderjoints,butisthereaqualitycriteriaforthesoldervoidsinpassivecomponents,includingresistors,capacitors,etc.?”

    Whenitcomestospecifications,wealwaysrefertoIPC610.Andtheanswerisyes.InIPC610DinSection5.2.2calledSolderAnomaliesittalksaboutpinholesandblowholes,butalsoaddressesvoids.IfdefinesadefectforClassIIandClassIIIproductsaspinholes,blowholes,orvoidswhichreducetheconnectionbelowtheminimumrequirements.

    Therequirementsforchipcomponents,resistorsandcapacitorsisgiveninIPC610DinSection8.2.2.Therearemanydifferentcategories,buttheytalkbasicallyaboutcoverageonthepadsandontheterminationsandanumberofthemgivepercentages.Sotheoretically,accordingtoIPC,youcouldmeasurethevoid.Ifit’saninternalvoidyou’llneedtouseanx-raymachine.Ifit’sanexternalvoidsuchasablowhole,youcouldjustmeasureitwithamicroscope.Andthenyoucouldapplythattothejointcategorysuchas50percentcoverage,75percentcoverage,andsoforththatarelistedinthe8.2.2sections.Thesemeasurementsaretheoreticallypossible,buttheyaretypicallyjudgmentcalls.

    Phil
    Whenwelookatthesespecs,we’rebasicallycomparingcontractareavoidswiththingslikemisalignments,skewedcomponents,thingsalongthoselines.

    Jim
    Sayyouhadavoidnearthetoeofasolderfilletandthespecsaysthatyouneedtohavelessthan75percentcoverage.Soyoulookatthecoverageandifavoidwasbiggerthan25percent,thatwouldreduceyourtotaltolessthan75percent.

    That’seasytosayherequotingnumbersoffthetopofourheads,butIthinkinreallife,it’ssubjective.Buttoansweryourquestion,yes,therearecriteriaandtheyaredefinedintheIPC.

    Phil
    Thetrickistodetermineifvoidsareasymptomoradefect,particularlybeforeyougoaboutdoinganyactualreworkingandmanipulationwhereyoucoulddomoreharmthangood.

    Jim
    Thatinitialspec,5.2.2,definesallvoids,blowholes,andpinholesasaprocessindicator.Soifyou’reseeingthem,they’retellingyouthatmaybethere’ssomethingwrong.Whetheraspecificonecausesyoutorejectapartorreworkitisoftenajudgmentcallagainstthecriteriain8.2.2.

  2. victor-he

    仅有底部端子焊料空洞—-因为对焊料高度没有要求,空洞不会影响最小焊接宽度要求,应该是可以允收的。

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