Dell大厂的PCB认证规程之染色

分享Dell大厂的PCB认证规程之染色标准！:victory:看看我们的NB的设计验证过程！！！

DyeandPryFailureAnalysisProcedure

Engineers/Owners:DellReliabilityOrganization&Component/MaterialsFailureAnalysisLab

DyeandPryProcedure
1.Purpose
ThepurposeofthisdocumentistodescribeindetailtheDyeandPryprocedurethatisrequiredtobeusedonproductsevaluatedforDell.ModificationstothisprocedureareacceptableifsuchmodificationsaresharedwithDellandapproved.
2.MinimumRequirements
1.Machinist’sdye(recommendationisRedSteelDykem).
2.Vacuumpumpandchamber(typicallyamechanicalpumpandbelljar).
3.Stereomicroscopewithdigitalcamera
4.Bakingovencapableof100C
5.Abilitytosectionoutdesiredcomponentsfromboardwithoutexertingexcessivestressonthesolderjoints.
6.Tooltoprythecomponentfromtheboard.
7.Fluxcleaningsolvent.
8.Trainedoperators.
3.Procedure
1.Identifycomponentstobe“DyeandPry”evaluated(consulttestplan).
2.Sectionoutthedesiredcomponentleavingabout1.5to2inchesofboardaroundthepart.
3.CleananyfluxresiduefromaroundtheBGAsolderbumpsusingasolvent(recommendusingaFluxRemoverspray-Isopropylalcoholaloneisnotacceptable).Removinganyfluxresiduesandotherparticles/oilsenablesthedyetomoreeasilypenetratethefractures.FailuretocompletelyremovefluxfromaroundtheBGAbumpsmaypreventinkpenetrationandgivefalseindicationsofagoodsolderjoint.
4.Rinsewellwithwater(followedbyisopropylalcoholifdesired).Allowtocompletelydry.
5.Immersethesectionedsampleinthedye(typicallyinasmalltray).
6.Placethetrayandsectionedsampleintoavacuumchamber.Drawavacuumfor3to4minutes.Partiallyventandreapplyvacuumtothechamberafewtimestoaidindyepenetration.
7.Turnoffvacuumpumpandleavethesampleinthedyeforseveralminutesundervacuum.
8.Ventanyremainingvacuumandremovesample.Allowtheexcessdyetodrainoffthesample.
9.Drythesampleinanovenbybakingat100°Cforupto30minutesdependingontheamountofdyeunderandaroundthedevice.Thedyemustbecompletelydried.Wetdyecansmearduringcomponentremovalresultinginfalseconclusions.