Reflowqhov cubyog qhov muag muag ntawm cov khoom siv hluav taws xob thiab hluav taws xob sib txuas ntawm qhov kawg ntawm cov khoom siv los yog cov pins ntawm cov khoom sib dhos thiab cov PCB ncoo los ntawm remelting soft paste solder khoom preassigned rau PCB ncoo.
SMD vuam yog ua tiav los ntawm lub cev cov tshuaj tiv thaiv ntawm gelatinized flux nyob rau hauv ib tug tej yam kub kub airflow los ntawm kev cia siab rau qhov kev txiav txim ntawm cov cua kub ntawm lub solder sib koom.
Cua sov cheeb tsam, tshav kub preservation tsam, vuam cheeb tsam, txias cheeb tsam.
1.Thaum PCB nkag mus rau thaj tsam cua sov, cov kuab tshuaj thiab cov roj hauv cov tshuaj txhuam hniav evaporate. Nyob rau tib lub sij hawm, cov flux nyob rau hauv lub solder paste wets lub ncoo, qhov kawg thiab pins ntawm lub tivthaiv, thiab solder paste softens thiab collapses, npog lub ncoo, cais lub ncoo, pins ntawm cov tivthaiv thiab oxygen.
2.PCB nkag mus rau hauv tshav kub preservationzone, thiaj li hais tias PCB thiab Cheebtsam yog tag nrho preheated, nyob rau hauv cov ntaub ntawv PCB dheev nkag mus rau hauv lub vuam kub cheeb tsam thiab puas PCB thiab cov khoom.
3.Thaum PCB nkag mus rau hauv qhov chaw vuam, qhov kub thiab txias tau nce sai heev kom cov tshuaj txhuam hniav mus txog lub xeev yaj, thiab cov kua nplaum ua kua ntub rau PCB ncoo, cov khoom xaus thiab cov pins, thiab diffuses, diffuses los yog backflows los ua cov neeg sib cuag.
4.PCB nkag mus rau hauv qhov chaw txias kom khov kho qhov sib koom ua ke thiab ua tiav tag nrho cov txheej txheem reflow vuam.
Nyob rau hauv SMT reflow qhov cub soldering txheej txheem, muaj peb lub ntsiab yog vim li cas rau lub uneven cua sov ntawm reflow Cheebtsam: qhov sib txawv ntawm lub tshav kub muaj peev xwm los yog nqus ntawm reflow Cheebtsam, lub hwj chim ntawm conveyor siv los yog rhaub ntug, thiab lub load ntawm reflow khoom.
1. Feem ntau, PLCC thiab QFP muaj peev xwm ua kom muaj cua sov ntau dua li cov ntaub ntawv sib cais, yog li nws nyuaj rau vuam thaj tsam loj dua li cov khoom me me.
2. Nyob rau hauv lub reflow vuam rauv, lub conveyor siv nyob rau hauv lub reflow vuam ntawm cov khoom, tab sis kuj los ua ib tug kub dissipation system, ntxiv rau lub cua sov ib feem ntawm ntug thiab qhov chaw ntawm lub tshav kub dissipation tej yam kev mob yog txawv, ntug kub. feem ntau tsis tshua muaj, ntxiv rau qhov ntsuas kub ntawm txhua qhov chaw kub hauv lub cub tawg, qhov sib txawv ntawm qhov kub thiab txias kuj tseem sib txawv.
3. Qhov sib txawv ntawm cov khoom thauj khoom. Qhov kub nkhaus ntawm reflow vuam yuav tsum tau kho kom tau zoo rov ua dua nyob rau hauv tsis muaj load, load thiab txawv load yam. Load factor yog txhais li LF=L/(L+S); Qhov twg L=qhov ntev ntawm cov khoom sib dhos, S=lub caij nyoog ntawm cov khoom sib dhos.
Qhov siab dua qhov load yam, qhov nyuaj dua nws yog kom tau zoo rov ua dua. Feem ntau qhov siab tshaj plaws load ntawm reflow rauv yog 0.5 ~ 0.9. Qhov no yog nyob rau cov khoom teeb meem no (feem vuam ceev, txawv substrate) thiab qhov sib txawv hom ntawm reflow rauv. Kev ua tau zoo yog qhov tseem ceeb kom ua tiav cov txiaj ntsig zoo vuam thiab rov ua dua.
