Cov xwm txheej twg yuav tsum muaj peev xwm ua tau raws li PCB?

Hauv kev ua SMT, PCB substrates ua ntej pib ua, PCB yuav raug kuaj thiab kuaj, xaiv kom tau raws li SMT cov kev cai ntawm PCB, thiab cov khoom tsis tsim nyog xa rov qab mus rau PCB tus neeg muag khoom, cov kev cai tshwj xeeb ntawm PCB tuaj yeem raug xa mus rau IPc-a-610c International General Electronics Industry Assembly Standards, cov hauv qab no yog qee yam ntawm cov kev cai yooj yim ntawm SMT ua ntawm PCB.

1. Lub PCB yuav tsum tiaj tus thiab du

PCB feem ntau yuav tsum tau tiaj tus thiab du, tsis tuaj yeem warp, los yog nyob rau hauv lub solder paste luam ntawv thiab SMT tshuab tso rau yuav tsim kev puas tsuaj loj, xws li qhov tshwm sim ntawm cov kab nrib pleb.

2. Cov thermal conductivity

Nyob rau hauv lub reflow soldering tshuab thiab yoj soldering tshuab, yuav muaj ib tug preheat cheeb tsam, feem ntau yog ua kom sov lub PCB tusyees, thiab rau ib tug tej yam kub thiab txias, qhov zoo dua thermal conductivity ntawm PCB substrate, tsim tsawg phem.

3. Thaum tshav kub kub tsis kam

Nrog rau txoj kev loj hlob ntawm SMT txheej txheem thiab ib puag ncig yuav tsum tau, cov txheej txheem tsis muaj txhuas kuj tau dav siv, tab sis kuj tshwm sim los ntawm kev nce hauv vuam kub, qhov kub tsis kam ntawm PCB siab dua, cov txheej txheem tsis muaj txhuas nyob rau hauv reflow soldering, qhov kub thiab txias yuav tsum. ncav cuag 217 ~ 245 ℃, lub sij hawm kav 30 ~ 65s, yog li qhov dav PCB tshav kub tsis kam mus rau 260 degrees Celsius, thiab lub xeem 10s yuav tsum tau.

4. Lub adhesion ntawm tooj liab ntawv ci

Lub zog sib txuas ntawm cov ntawv ci tooj liab yuav tsum ncav cuag 1.5kg / cm² los tiv thaiv PCB los ntawm kev poob vim yog sab nraud.

5. Khoov qauv

PCB muaj cov qauv khoov, feem ntau ua tiav ntau dua 25kg / hli

6. Zoo hluav taws xob conductivity

PCB raws li tus neeg nqa khoom ntawm cov khoom siv hluav taws xob, kom ua tiav qhov kev sib txuas ntawm cov khoom sib txuas, tso siab rau cov kab PCB los ua, PCB yuav tsum tsis yog tsuas yog muaj cov khoom siv hluav taws xob zoo xwb, thiab cov kab PCB tawg tsis tuaj yeem ncaj qha patch, lossis kev ua haujlwm ntawm tag nrho cov khoom. yuav ua rau muaj kev cuam tshuam loj heev.

7. tuaj yeem tiv taus cov kuab tshuaj ntxuav

PCB nyob rau hauv ntau lawm, yooj yim kom tau qias neeg, feem ntau yuav tsum tau ntxuav lub board dej thiab lwm yam kuab tshuaj ntxuav, yog li PCB yuav tsum muaj peev xwm tiv taus cov kuab tshuaj ntxuav, tsis ua npuas thiab lwm yam kev phiv tshuaj.

Cov no yog qee yam ntawm cov kev cai yooj yim rau kev tsim nyog PCB hauv kev ua SMT.