深圳市福英達(dá)工業(yè)技術(shù)有限公司/一站式錫膏解決方案供應(yīng)商HowtoAvoidtheProblemofDroppingPartsoftheSecondReflowWhenDouble-SidedMounting?

Double-sidedmountingprocesscanimprovetheactualutilisationofPCB,reducemanufacturingcosts,andmeetthedemandforminiaturisationandhighintegrationofendproducts.However,theuseofdouble-sidedmounting,double-sidedreflowprocesswillbringthefollowingproblems.First,thesecondreflow,thebottomofthelargerorheaviercomponentsmayfallduetogravityorvibration,andthesecondisthebottomofthesolderjointswillaffectthereliabilityofthesolderjointsbecauseofthemeltingagain.Thefollowingmethodsaregenerallyusedtosolvetheproblemofcomponentdropouts:1.Chooseasolderpastewithhigherviscosity.Formostcomponents,thesecondreflow,thesurfacetensionofthesolderjointsmoltensolderpastecanmaintainthecomponentsonthebottomoftheviscousforce,sothatthecomponentsarefirmlyfixedonthesubstrate?Obviously,thereisacomponentqualityandpin(pad)tensionoftheproportionalityoftherelationship,someresearchconclusionsshowthatwhenthecomponentonthebottomoftheviscousforce≥4.65g/cm2willnotfall.2.Usinghigh-temperature+low-temperaturesolderpasteoverthereflowoven.Thatis,inthefirstreflowprintinghigh-temperaturesolderpaste,thesecondreflowwhentheuseoflow-temperaturesolderpaste,toavoidthefirstreflowsolderingpointsolderpastere-melting.Thismethodshouldpayattentiontothewarpingandpadoffsetproblemsbroughtaboutbyhigh-temperaturesoldering.3.Fortheheavierqualitycomponentsselectedinthesecondsolderingoverreflow.Fitech

SecondaryReflowSolutionsShenzhenFitechCo.,Ltd.developedFL170/180/200seriesofmicro-nanoparticle-enhancedlow-temperaturehigh-strengthsolder,theuseofmicro-nanoparticle-enhancedparticlesdispersedinthesolder,refiningtheorganisationalstructure,inhibittheenrichmentofBi,thereliabilityoftheproducthasbeensignificantlyimproved.TheproducthasbeenpatentedintheUnitedStatesandJapan.InthefirstreflowchooseSAC305,peaktemperature245℃,meltingpoint217~219℃;thesecondreflowpeaktemperatureoptionalFL170/180/200,