Reflow flow welding yog hais txog cov txheej txheem vuam uas paub txog kev sib txuas ntawm cov khoom siv thiab hluav taws xob ntawm cov khoom siv los yog cov pins ntawm cov khoom sib dhos thiab cov PCB solder pads los ntawm melting solder paste pre-printed on PCB solder pads.
1. txheej txheem ntws
Txheej txheem khiav ntawm reflow soldering: luam ntawv solder paste → mounter → reflow soldering.
2. Cov yam ntxwv txheej txheem
Lub solder sib koom loj yog tswj tau.Qhov xav tau qhov loj me lossis cov duab ntawm qhov sib koom ua ke tuaj yeem tau txais los ntawm qhov tsim ntawm lub ncoo thiab tus nqi ntawm cov ntawv luam tawm.
Vuam muab tshuaj txhuam feem ntau yog siv los ntawm steel screen printing.Txhawm rau kom yooj yim cov txheej txheem ntws thiab txo cov nqi tsim khoom, feem ntau tsuas yog ib qho vuam muab tshuaj yog luam tawm rau txhua qhov chaw vuam.Qhov tshwj xeeb no xav kom cov khoom ntawm txhua lub ntsej muag tuaj yeem faib cov tshuaj txhuam hniav siv ib qho mesh (suav nrog ib lub mesh ntawm tib lub thickness thiab ib kauj ruam mesh).
Lub reflow rauv yog qhov ua tau ntau qhov kub ntawm qhov cub uas nws lub luag haujlwm tseem ceeb yog kom sov PCBA.Cov khoom siv hauv qab (sab B) yuav tsum ua kom tau raws li qhov yuav tsum tau ua ntawm cov khoom siv kho tshuab, xws li BGA pob, cov khoom siv loj thiab tus pin kov thaj tsam piv ≤0.05mg / mm2, txhawm rau tiv thaiv cov khoom saum npoo saum npoo los ntawm kev poob thaum vuam.
Nyob rau hauv reflow soldering, cov tivthaiv yog kiag li ntab rau molten solder (solder joint).Yog hais tias lub ncoo loj dua tus pin loj, qhov kev tivthaiv layout hnyav dua, thiab tus pin layout yog me me, nws yog feem ntau yuav tsiv mus nyob rau asymmetric molten solder nto nro los yog yuam convective kub cua tshuab nyob rau hauv lub reflow furnace.
Feem ntau hais lus, rau cov khoom uas tuaj yeem kho lawv txoj haujlwm los ntawm lawv tus kheej, qhov loj dua qhov sib piv ntawm qhov loj ntawm lub ncoo mus rau qhov sib tshooj ntawm cov vuam kawg lossis tus pin, qhov muaj zog dua qhov kev ua haujlwm ntawm cov khoom.Nws yog qhov taw tes no uas peb siv rau kev tsim tshwj xeeb ntawm cov ntaub qhwv ntsej nrog qhov yuav tsum tau ua.
Qhov tsim ntawm weld (spot) morphology feem ntau yog nyob ntawm qhov kev txiav txim ntawm kev muaj peev xwm ntub dej thiab qhov nro ntawm cov molten solder, xws li 0.44mmqfp.Cov luam ntawv solder paste qauv yog niaj zaus cuboid.
Post lub sij hawm: Dec-30-2020