Hauv kev tsim hluav taws xob, kev tsim cov ntaub qhwv ntsej yog ib qho tseem ceeb hauv kev tsim pcb, uas cuam tshuam ncaj qha rau kev teeb tsa zoo ntawm cov khoom siv thiab kev ua haujlwm ntawm cov khoom siv hluav taws xob.
1, Cov ntsiab lus tseem ceeb thiab lub hom phiaj ntawm cov ntaub qhwv ntsej muag
Lub taub hau solder yog thaj chaw hlau ntawm lub rooj tsav xwm luam tawm siv rau kev sib txuas cov pins, feem ntau yog ua los ntawm tooj liab. Nws lub hom phiaj tseem ceeb yog los xyuas kom ruaj khov kev sib txuas ntawm cov khoom siv hluav taws xob thiab hluav taws xob ntawm cov khoom siv thiab cov khoom siv hluav taws xob. Qhov zoo ntawm solder ncoo tsim ncaj qha cuam tshuam rau lub zog soldering, hluav taws xob kev ua tau zoo, thiab tag nrho kev ntseeg siab ntawm pcb. Yog li ntawd, kev tsim cov ntaub qhwv ntsej muag yog qhov tseem ceeb uas tsis tuaj yeem tsis quav ntsej hauv pcb layout thiab kev tsim khoom.
2, Txuj rau qhov loj thiab cov duab ntawm cov ntaub qhwv
Qhov loj thiab cov qauv tsim ntawm cov ntaub qhwv yuav tsum coj mus rau hauv tus account txheej txheem manufacturability, tivthaiv soldering yuav tsum, thiab hluav taws xob kev ua tau zoo. Cov hom ntawm solder pads yog raws li nram no:
Los ntawm - lub qhov rooj
Los ntawm lub qhov ncoo yog ib qho chaw siv rau kev ntxig cov khoom, feem ntau nrog cov qhov drilling, rau cov khoom siv pins kom dhau los ntawm pcb. Hom pad solder no yuav tsum tau tsim raws li txoj kab uas hla ntawm cov tivthaiv pins thiab thickness ntawm pcb txheej los xyuas kom meej txaus solder filling. Tus txheej txheem IPC-2221 pom zoo tias cov ntaub qhwv lub ntsej muag yuav tsum yog kwv yees li 0.2-0.3mm loj dua li tus pin txoj kab uas hla ntawm cov khoom kom ntseeg tau tias tus pin hla thiab tawm qhov chaw rau solder filling.
Nto mount solder pads
Surface mount pads yog siv rau soldering nto mount Cheebtsam yam tsis tas yuav tsum tau perforation. Nws qhov loj me thiab cov duab yuav tsum ua raws li qhov loj me thiab kev teeb tsa ntawm cov khoom siv pins. Tus txheej txheem IPC-7351A muab cov lus qhia ntxaws ntxaws rau kev tsim cov pob zeb saum npoo av, nrog cov duab zoo xws li cov duab plaub, elliptical, thiab ncig. Thaum tsim, qhov kev faib tawm ntawm solder yuav tsum tau xav txog. Cov ntaub qhwv uas me dhau tuaj yeem ua rau tsis zoo, thaum lub ncoo uas loj dhau yuav ua rau cov hlua khi.
Pad sib nrug
Qhov sib nrug ntawm cov ntaub qhwv lub ntsej muag txiav txim siab seb lub voj voog luv lossis cov teeb meem virtual yuav tshwm sim thaum lub sij hawm soldering. Raws li tus qauv IPC-2221, qhov tsawg kawg nkaus ntawm qhov sib txawv ntawm cov ntaub qhwv yuav tsum coj mus rau hauv tus account tsim cov txheej txheem muaj peev xwm thiab cov khoom sib txuas sib txuas, tshwj xeeb tshaj yog cov qauv tsim rau cov khoom zoo. Feem ntau hais lus, qhov tsawg kawg nkaus ntawm qhov sib txawv ntawm cov ntaub qhwv yuav tsum tsis pub tsawg tshaj 0.2 hli kom ntseeg tau tias qhov zoo ntawm cov khoom siv hluav taws xob thiab cov khoom siv hluav taws xob.
3, Tej teeb meem thiab kev daws teeb meem
Pad peeling
Pad peeling feem ntau yog tshwm sim los ntawm kev tsim tsis raug lossis kev ntxhov siab ntau dhau thaum ua haujlwm. Tus yuam sij rau kev daws qhov teeb meem no yog nyob rau hauv kev tswj kom raug qhov adhesion ntawm cov ntaub so ntswg thiab cov pcb substrate, thiab xyuas kom meej tias qhov loj ntawm cov ntaub so ntswg yog tsim nyog thaum lub sij hawm tsim, tshwj xeeb tshaj yog nyob rau hauv high tam sim no qhov chaw uas lub solder pad cheeb tsam yuav tsum tau kom tsim nyog nce.
solder txuas
Solder bridging yog hais txog kev sib txuas ntawm solder ntawm solder pads, ua rau luv luv Circuit Court. Qhov laj thawj yog vim li cas qhov sib txawv ntawm cov ntaub qhwv ntsej muag me me dhau los yog cov ntaub qhwv lub ntsej muag loj dhau. Cov kev daws teeb meem suav nrog nce qhov sib txawv ntawm lub ncoo, txo cov ncoo loj, lossis kho cov txheej txheem vuam tsis zoo.
Pad oxidation
Pad oxidation tuaj yeem ua rau tsis zoo soldering lossis virtual soldering. Txhawm rau zam qhov teeb meem no, nws raug nquahu kom xaiv cov ntaub ntawv ncoo nrog kev tiv thaiv oxidation thaum lub sijhawm tsim, xws li OSP, tin plating, lossis kub plating. Nyob rau tib lub sijhawm, xyuam xim rau qhov chaw cia khoom ntawm cov khoom thiab pcbs kom tsis txhob raug huab cua ntau dhau uas yuav ua rau cov ntaub qhwv oxidation.
4, Kev lag luam cov qauv thiab cov txheej txheem
Cov qauv kev lag luam thiab cov txheej txheem rau kev tsim cov ntaub qhwv ntsej muag muab lub hauv paus siv rau kev tsim. Cov hauv qab no yog cov qauv tsim qauv pad:
IPC-2221: Cov qauv dav dav rau cov khoom siv hluav taws xob sib txuas tsim, npog cov qauv tsim xws li cov ntaub qhwv, cov xov hlau, qhov sib nrug, thiab lwm yam.
IPC-7351A: Nto mount tsim tus qauv, muab cov ncauj lus qhia ntxaws ntxaws rau cov ntaub ntawv tsim ntawm cov khoom siv saum npoo av.