Hom Sn96.5Ag3.0Cu0.5 alloy tsoos txhuas-dawb reflow soldering kub nkhaus.A yog thaj chaw cua sov, B yog qhov kub thiab txias (qhov chaw ntub dej), thiab C yog qhov chaw tin melting.Tom qab 260S yog qhov chaw txias.
Sn96.5Ag3.0Cu0.5 alloy tsoos txhuas-dawb reflow soldering kub nkhaus
Lub hom phiaj ntawm cua sov cheeb tsam A yog kom ceev ceev ntawm PCB pawg thawj coj saib mus rau lub flux activation kub.Qhov kub nce ntawm chav tsev kub txog li 150 ° C nyob rau hauv li 45-60 vib nas this, thiab txoj kab nqes yuav tsum nyob nruab nrab ntawm 1 thiab 3. Yog hais tias qhov kub thiab txias nce ceev heev, nws yuav vau thiab ua rau muaj teeb meem xws li cov hlaws hlaws thiab kev sib txuas.
Qhov ntsuas kub tsis tu ncua B, qhov kub nce maj mam ntawm 150 ° C txog 190 ° C.Lub sij hawm yog raws li cov khoom siv tshwj xeeb thiab tswj tau li ntawm 60 mus rau 120 vib nas this kom muab kev ua si tag nrho rau kev ua haujlwm ntawm cov kuab tshuaj flux thiab tshem tawm oxides ntawm qhov chaw vuam.Yog tias lub sijhawm ntev dhau lawm, kev ua haujlwm ntau dhau yuav tshwm sim, cuam tshuam rau qhov vuam zoo.Nyob rau theem no, tus neeg sawv cev nquag hauv cov kuab tshuaj flux pib ua haujlwm, thiab cov rosin resin pib muag thiab ntws.Tus neeg sawv cev nquag nthuav tawm thiab nkag mus nrog cov rosin resin ntawm PCB ncoo thiab qhov kawg ntawm qhov chaw, thiab cuam tshuam nrog cov oxide nto ntawm lub ncoo thiab ib feem ntawm qhov chaw.Cov tshuaj tiv thaiv, ntxuav qhov chaw kom welded thiab tshem tawm impurities.Nyob rau tib lub sijhawm, cov rosin resin nthuav dav sai los tsim cov yeeb yaj kiab tiv thaiv ntawm txheej txheej ntawm vuam nto thiab cais nws los ntawm kev sib cuag nrog cov pa sab nraud, tiv thaiv qhov vuam nto ntawm oxidation.Lub hom phiaj ntawm kev teeb tsa lub sijhawm ntsuas kub kom txaus yog tso cai rau PCB ncoo thiab cov khoom kom ncav cuag qhov kub thiab txias ua ntej reflow soldering thiab txo qhov kub ntawm qhov sib txawv, vim hais tias lub peev xwm nqus cua sov ntawm cov khoom sib txawv ntawm PCB sib txawv heev.Tiv thaiv kom tsis txhob muaj teeb meem zoo los ntawm qhov kub tsis txaus thaum lub sij hawm reflow, xws li tombstones, cuav soldering, thiab lwm yam. Yog hais tias qhov kub thiab txias cheeb tsam heats li sai heev, cov flux nyob rau hauv lub solder paste yuav sai sai nthuav thiab volatilize, ua rau ntau yam teeb meem zoo xws li pores, tshuab. tin, thiab tin hlaws.Yog hais tias lub sij hawm kub tsis tu ncua ntev dhau lawm, cov kuab tshuaj flux yuav evaporate ntau dhau thiab poob nws cov haujlwm thiab kev tiv thaiv kev ua haujlwm thaum lub sij hawm reflow soldering, uas ua rau muaj qhov tshwm sim tsis zoo xws li cov khoom siv hluav taws xob, cov khoom siv hluav taws xob dub, thiab cov pob qij txha dull.Hauv kev tsim khoom tiag tiag, lub sijhawm ntsuas kub tsis tu ncua yuav tsum tau teeb tsa raws li cov yam ntxwv ntawm cov khoom siv tiag tiag thiab cov khoom siv lead-free solder paste.
Lub sijhawm tsim nyog rau thaj tsam C yog 30 txog 60 vib nas this.Lub sij hawm luv luv ntawm tin melting yuav ua rau muaj qhov tsis zoo xws li tsis muaj zog soldering, thaum lub sij hawm ntev heev yuav ua rau cov hlau dielectric ntau dhau los yog ua rau cov pob qij txha ua kom tsaus.Thaum lub sij hawm no, cov hmoov hlau alloy nyob rau hauv cov tshuaj pleev ib ce melts thiab reacts nrog cov hlau ntawm qhov chaw soldered.Lub flux solvent boils nyob rau lub sij hawm no thiab accelerates volatilization thiab infiltration, thiab overcomes nto nro nyob rau hauv high kub, tso cai rau cov kua alloy solder ntws nrog flux, kis rau ntawm qhov chaw ntawm lub ncoo thiab qhwv lub soldering kawg nto ntawm ib feem rau daim ntawv. ib tug wetting nyhuv.Raws li txoj cai, qhov kub thiab txias, qhov zoo dua cov nyhuv ntub dej.Txawm li cas los xij, hauv kev siv tswv yim, qhov siab tshaj plaws ntawm kev ua siab ntev ntawm PCB pawg thawj coj saib thiab cov khoom yuav tsum raug txiav txim siab.Kev hloov pauv ntawm qhov kub thiab lub sijhawm ntawm thaj chaw reflow soldering yog txhawm rau nrhiav qhov sib npaug ntawm qhov kub thiab txias thiab cov nyhuv soldering, uas yog, kom ua tiav qhov zoo tshaj plaws soldering zoo nyob rau hauv lub siab kub thiab lub sijhawm.
Tom qab vuam cheeb tsam yog qhov chaw txias.Nyob rau hauv theem no, lub solder cools down los ntawm cov kua rau cov khoom los ua solder pob qij txha, thiab siv lead ua nplej yog tsim nyob rau hauv lub solder pob qij txha.Kev txias nrawm tuaj yeem tsim cov pob qij txha txhim khu kev qha nrog ci ci.Qhov no yog vim tias qhov txias txias tuaj yeem ua rau cov hlau sib koom ua ib qho hlau nrog cov qauv nruj, thaum lub caij txias qeeb yuav ua rau muaj ntau qhov sib txawv thiab tsim cov nplej loj rau ntawm qhov sib koom ua ke.Qhov kev ntseeg ntawm cov neeg kho tshuab lub zog ntawm xws li ib tug solder sib koom yog tsawg, thiab qhov saum npoo ntawm lub solder sib koom yuav tsaus nti thiab tsis tshua muaj gloss.
Teem cov hlau lead-dawb reflow soldering kub
Nyob rau hauv cov txheej txheem ntawm cov hlau lead-dawb reflow soldering, lub cub tawg yuav tsum tau ua tiav los ntawm tag nrho cov ntawv hlau.Yog tias lub qhov cub tawg yog ua los ntawm cov ntawv me me ntawm cov ntawv hlau, warping ntawm lub cub tawg yuav yooj yim tshwm sim nyob rau hauv qhov kub tsis muaj hlau lead.Nws yog ib qho tsim nyog los ntsuas qhov sib npaug ntawm qhov sib npaug ntawm qhov kub qis.Yog hais tias tus khiav yog deformed ntawm qhov kub thiab txias vim cov ntaub ntawv thiab tsim, jamming thiab ntog ntawm lub rooj tsavxwm yuav tsis raug zam.Yav dhau los, Sn63Pb37 leaded solder yog ib qho khoom siv.Crystalline alloys muaj qhov sib txawv ntawm qhov kub thiab txias, ob qho tib si 183 ° C.Cov hlau lead-dawb solder sib koom ntawm SnAgCu tsis yog eutectic alloy.Nws cov ntsiab lus melting yog 217 ° C-221 ° C.Qhov kub yog qhov ruaj khov thaum qhov kub qis dua 217 ° C, thiab qhov kub yog kua thaum kub siab tshaj 221 ° C.Thaum qhov kub thiab txias ntawm 217 ° C thiab 221 ° C Cov hlau ua rau lub xeev tsis ruaj khov.
Post lub sij hawm: Nov-27-2023