Tom qab lub PCB tsim tiav, txhua yam yuav zoo? Qhov tseeb, qhov no tsis yog qhov xwm txheej. Nyob rau hauv cov txheej txheem ntawm PCB ua, ntau yam teeb meem feem ntau ntsib, xws li nruam tin tom qab yoj soldering. Tau kawg, tsis yog txhua qhov teeb meem yog “lub lauj kaub” ntawm PCB tsim, tab sis raws li cov neeg tsim qauv, peb yuav tsum xub xyuas kom meej tias peb cov qauv tsim dawb.

Glossary

Vuam soldering

Wave soldering yog ua kom lub ntsej muag ntawm lub rooj tsav xwm plug-in ncaj qha hu rau lub siab kub ua kua tin kom ua tiav lub hom phiaj ntawm kev sib txuas. Lub siab kub ua kua tin tuav txoj kab nqes, thiab cov cuab yeej tshwj xeeb ua rau cov kua tin tsim ib qho tshwm sim zoo li nthwv dej, yog li nws hu ua “wave soldering”. Cov khoom tseem ceeb yog solder tuav.

Vim li cas PCB board tshwm nrog tin tom qab yoj soldering? Yuav zam tau li cas?

Wave soldering txheej txheem

Ob lossis ntau dua cov pob qij txha txuas nrog cov khoom siv, ua rau cov tsos mob tsis zoo thiab kev ua haujlwm, uas tau teev tseg raws li qib tsis xws luag los ntawm IPC-A-610D.

Vim li cas PCB board tshwm nrog tin tom qab yoj soldering?

Ua ntej tshaj plaws, peb yuav tsum ua kom pom tseeb tias qhov muaj cov tin ntawm lub rooj tsavxwm PCB tsis tas yuav yog qhov teeb meem ntawm kev tsim PCB tsis zoo. Nws kuj tseem yuav yog vim cov dej ntws tsis zoo, tsis muaj dej tsis txaus, daim ntawv thov tsis sib xws, preheating thiab solder kub thaum lub sij hawm yoj soldering. Zoo tos rau qhov laj thawj.

Yog tias nws yog PCB tsim teeb meem, peb tuaj yeem txiav txim siab los ntawm cov hauv qab no:

1. Txawm hais tias qhov kev ncua deb ntawm cov pob qij txha ntawm cov khoom siv yoj soldering yog txaus;

2. Puas yog qhov kev taw qhia kev sib kis ntawm lub plug-in tsim nyog?

3. Nyob rau hauv rooj plaub uas lub suab tsis tau raws li cov txheej txheem yuav tsum tau, puas muaj ib tug tin stealing ncoo thiab silk screen number case ntxiv?

4. Seb qhov ntev ntawm lub plug-in pins ntev dhau lawm, thiab lwm yam.

Yuav ua li cas kom tsis txhob tin hauv PCB tsim?

1. Xaiv cov khoom tsim nyog. Yog hais tias lub rooj tsavxwm xav tau yoj soldering, qhov pom zoo cov cuab yeej sib nrug (nruab nrab qhov sib nrug ntawm PINs) yog ntau dua 2.54mm, thiab nws raug pom zoo kom siab dua 2.0mm, txwv tsis pub qhov kev pheej hmoo ntawm tin kev twb kev txuas kuj yog siab. Ntawm no koj tuaj yeem hloov kho qhov zoo ntawm lub ncoo kom ua tau raws li cov txheej txheem ua haujlwm thaum tsis txhob sib txuas tin.

2. Tsis txhob nkag mus rau hauv ko taw soldering tshaj 2 hli, txwv tsis pub nws yooj yim heev los txuas cov tin. Tus nqi empirical, thaum qhov ntev ntawm cov hlau lead tawm ntawm lub rooj tsavxwm yog ≤1mm, lub caij nyoog ntawm kev sib txuas ntawm cov tin ntawm lub qhov (socket) ntom ntom ntom ntom yuav raug txo kom tsawg.

3. Qhov kev ncua deb ntawm lub nplhaib tooj liab yuav tsum tsis pub tsawg tshaj 0.5 hli, thiab cov roj dawb yuav tsum tau ntxiv ntawm cov nplhaib tooj liab. Qhov no yog vim li cas peb feem ntau muab ib txheej ntawm silkscreen dawb roj rau ntawm qhov chaw vuam ntawm lub plug-in thaum tsim. Thaum lub sij hawm tsim cov txheej txheem, thaum lub ncoo qhib nyob rau hauv lub solder daim npog qhov ncauj, xyuam xim rau kom tsis txhob muaj cov roj dawb ntawm lub silk screen.

4. Tus choj ntsuab roj yuav tsum tsis pub tsawg tshaj 2mil (tshwj tsis yog rau saum npoo mount pin-intensive chips xws li QFP tej pob khoom), txwv tsis pub nws yog ib qho yooj yim uas yuav ua rau tin kev sib txuas ntawm cov ntaub so ntswg thaum ua.

5. Cov kev taw qhia ntev ntawm cov khoom sib txuas nrog cov kev taw qhia ntawm lub rooj tsavxwm hauv kev khiav, yog li tus naj npawb ntawm cov pins rau tuav cov tin txuas yuav raug txo kom tsawg. Hauv cov txheej txheem tsim PCB kev tshaj lij, tus qauv tsim txiav txim siab ntau lawm, yog li cov kev taw qhia kis tau tus mob thiab qhov chaw ntawm yoj soldering cov cuab yeej ua tau zoo heev.

6. Ntxiv tin stealing pads, ntxiv tin stealing pads ntawm qhov kawg ntawm cov kev taw qhia kis tau tus mob raws li qhov yuav tsum tau layout ntawm lub plug-in ntawm lub rooj tsavxwm. Qhov luaj li cas ntawm cov tin stealing ncoo tuaj yeem hloov kho kom haum raws li qhov ceev ntawm lub rooj tsavxwm.

7. Yog hais tias koj yuav tsum siv lub denser pitch plug-in, peb muaj peev xwm nruab ib tug solder drag piece nyob rau hauv lub Upper tin txoj hauj lwm ntawm lub fixture los tiv thaiv lub solder paste los ntawm kev tsim thiab ua rau cov tivthaiv taw mus rau lub tin.