1. PCB zoo, cov khoom siv
PCB pads (PAD) tsim tsis tsim nyog, yog tias cov khoom siv ntawm lub cev muaj zog ntau dhau ntawm PAD kom nyem tawm ntau dhau ntawm cov nplaum nplaum, tuaj yeem tsim cov hlaws dai.
PCB tsim, peb yuav tsum xaiv cov pob khoom tsim nyog thiab PAD txoj cai.
PCB solder tiv thaiv zaj duab xis luam ntawv tsis zoo, ntxhib nto, ua rau reflow tin hlaws, yuav tsum nruj dua PCB cov khoom nkag mus rau hauv kev tshuaj xyuas, solder tiv thaiv zaj duab xis yog qhov phem heev, yuav tsum tau batch rov qab los yog cov khoom seem.
Solder pads nrog dej los yog av, uas ua rau tin hlaws, yuav tsum ua tib zoo tshem tawm cov dej los yog av ntawm PCB, thiab ces muab tso rau hauv ntau lawm.
Tsis tas li ntawd, feem ntau ntsib cov neeg siv khoom rau cov khoom siv rau cov khoom siv sib txawv ntawm cov khoom siv hloov pauv, ua rau cov khoom siv thiab PAD tsis sib xws, yooj yim los tsim cov hlaws dai, yog li yuav tsum sim zam kev hloov pauv.
2. PCB yog damp
PCB nyob rau hauv noo noo ntau dhau, tom qab mounting tshaj reflow rauv, vim ya raws sai expansion tsim roj, tsim tin hlaws dai. Yuav tsum tau PCB yuav tsum tau qhuav lub tshuab nqus tsev ntim ua ntej muab tso rau hauv SMT ntau lawm, xws li ya raws yuav tsum tau siv tom qab ci nrog qhov cub. Rau cov organic solder film (OSP) board, tsis pub ci. Raws li lub voj voog ntau lawm, OSP pawg thawj coj tsis yog ntau tshaj 3 lub hlis tuaj yeem ua rau ntawm kab ntau lawm, ntau tshaj 3 lub hlis yuav tsum tau hloov cov khoom siv.
3. Slaus paste xaiv
Solder paste ho cuam tshuam rau qhov zoo ntawm soldering, cov ntsiab lus hlau ntawm paste, oxide cov ntsiab lus, hlau hmoov particle loj, muab tshuaj txhuam kev ua si, thiab lwm yam. tag nrho cov cuam tshuam rau kev tsim cov tin hlaws mus rau ntau yam degrees.
Cov ntsiab lus hlau, viscosity. Raws li ib txwm muaj, qhov sib piv ntawm cov ntsiab lus hlau nyob rau hauv cov tshuaj txhuam yog li 5 0 feem pua, qhov loj piv yog li 89 feem pua rau 91 feem pua, thiab tus so yog flux (Flux), rheology regulator, viscosity tswj tus neeg saib xyuas , hnyav, thiab lwm yam .. Yog hais tias qhov kev faib ua feem ntawm flux yog ntau dhau, lub viscosity ntawm solder muab tshuaj yog txo, thiab nyob rau hauv lub preheating cheeb tsam, lub zog generated los ntawm flux vaporization yog loj heev los tsim tin hlaws dai. Solder paste viscosity yog ib qho tseem ceeb cuam tshuam rau kev luam ntawv, feem ntau ntawm 0.5 ~ 1.2 K Pa-s, stencil printing, qhov zoo tshaj plaws paste viscosity ntawm txog 0.8 KPa-s. Cov ntsiab lus hlau nce, qhov muab tshuaj viscosity nce, tuaj yeem tiv thaiv lub zog ntawm vaporization hauv thaj chaw preheat, kuj tuaj yeem txo cov paste tom qab luam ntawv sib tsoo, tuaj yeem txo cov hlaws dai.
Cov ntsiab lus oxide. Oxide cov ntsiab lus hauv cov tshuaj txhuam hniav kuj tseem cuam tshuam rau cov nyhuv soldering. Qhov siab dua cov ntsiab lus oxide, qhov ntau dua qhov tsis kam ntawm cov hmoov hlau melting ua ke nrog cov txheej txheem, reflow theem, cov hlau hmoov saum npoo oxide cov ntsiab lus tseem yuav nce ntxiv, tsis zoo rau cov ntaub qhwv "wetting" thiab tsim cov hlaws dai. Yog li ntawd, nyob rau hauv cov txheej txheem hlau hmoov (Powder) yuav tsum tau lub tshuab nqus tsev ua haujlwm los tiv thaiv Powder oxidation.
Lub particle loj ntawm hlau hmoov, uniformity. Hlau hmoov yog zoo heev spherical hais, nws cov duab, txoj kab uas hla loj thiab uniformity yog cuam tshuam rau nws printing kev kawm. Cov khoom me me hauv cov ntsiab lus oxide yog siab dua, yog tias qhov kev faib ua feem ntawm cov khoom zoo, yuav muaj kev luam ntawv zoo dua, tab sis nws yog ib qho yooj yim los tsim cov npoo tawg, kom qhov nce hauv tin hlaws; ib qho kev faib ua feem loj ntawm cov khoom loj, yog li ntawd txawm tias tin tau nce, nws qhov sib txawv ntawm qhov sib txawv loj, yuav ua rau muaj kev nce hauv tin hlaws.
Solder paste kev ua. Solder paste kev ua haujlwm tsis zoo, qhuav sai heev, yog tias koj ntxiv cov thinner ntau dhau, nyob rau hauv qhov chaw preheating, lub zog tsim los ntawm thinner vaporization yog loj heev yooj yim los tsim tin hlaws. Yog tias koj ntsib kev ua tsis zoo ntawm cov tshuaj txhuam hniav, nws yog qhov zoo tshaj kom tsis txhob siv cov kev hloov pauv ntawm qhov zoo.
