Kev Tu Kom Muaj Teeb Meem ntawm PCB Luam Tawm Circuit Board
May 06, 2020
Nrog rau kev tsim kho ntawm cov khoom siv hluav taws xob, ntau lub chaw lag luam nyob hauv tsev thiab txawv teb chaws tau siv yoj soldering thiab reflow soldering thev naus laus zis thiab khoom siv, uas tsis tsuas yog txhim kho kev tsim khoom, tab sis tseem txhim kho vuam zoo. Txawm li cas los xij, vim muaj ntau qhov muaj kuab paug rau ntau yam, qhov kev hloov kho thiab luv ntawm qhov hluav taws xob luam tawm Circuit Court board thiab cov cheebtsam tau muaj kev cuam tshuam loj heev rau kev ntseeg tau ntawm cov ntawv luam tawm Circuit. Yog li, kev tu vaj tu tsev ntawm cov ntawv luam tawm Circuit thiab cov ntawv luam tawm hauv Circuit Court (PCA), tshwj xeeb tshaj yog cov khoom lag luam tsim nyog.
Cov pa phem PCB nyob rau hauv kev sib dhos thiab vuam txheej txheem feem ntau yog los ntawm kev tuav, siv flux, vuam cov txheej txheem thiab thaj chaw ua haujlwm, ua rau muaj kuab paug ib puag ncig txawv. Qhov kub thiab txias nyob ib puag ncig yuav ua rau muaj kuab paug paug ntau qhov. Qhov theem ntawm kev pheej hmoo yog nyob ntawm lub sijhawm khaws cia thiab qhov ntev ntawm cov chaw khaws khoom.
1 .Tus hmoov txhuas ua paug
Feem ntau cov pa phem ntawm cov tivthaiv cov txhuas yog cov hlau oxidation thiab cov pa luam yeeb, xws li oxide zaj duab xis ntawm cov xim txhuas nickel-plated lead, tooj liab plating lossis qee hom tin-plated oxide zaj duab xis ntawm cov txheej txheem txhuas. Thaum oxides tsim nyob rau saum npoo ntawm txheej, xim txheej xim tsaus, txo qhov solderability ntawm feem tivthaiv hmoov txhuas. Muaj ntau ntau yam ua rau oxides. Ntxiv nrog rau kev tsim cov txheej txheem ntawm cov seem lawv tus kheej, lub ntsiab tseem ceeb yog lub sijhawm khaws cia thiab ib puag ncig ntawm cov feem. Lub hauv paus tseem ceeb ntawm cov ntiv tes yog dej, daim tawv nqaij roj thiab sodium chloride, ntxiv rau cov khoom siv tes thiab tshuaj pleev ib ce, uas hnov mob rau qee yam nrog rau cov txheej hauv qab, yog li txo cov solderability ntawm cov hlau lead ntawm lub cuab yeej.
2 .Hauv paug los ntawm luam tawm Circuit board board cov haujlwm
Thaum lub sijhawm sib sau ua ke ntawm pawg thawj coj saib hauv Circuit Court, qee ntu yuav tsum muaj kev tiv thaiv nrog lub npog ntsej muag, thiab qee qhov yuav tsum tau kho los yog ntim nrog roj hmab silicone, epoxy resin, thiab lwm yam." khiav" los ntawm ham lossis yas tebchaw. ntub. Cov qhov ncauj qhov ntswg feem ntau siv rau hauv kev sib dhos yog cov kab xev, thermoplastic polymer, butyl ester lossis hloov butyl ester, ammonia latex, kua roj hmab silicone, thiab cov kua polymer yaj hauv siab vapor siab hnyav. Raws li qhov ua tiav ntawm qhov kub thiab txias vuam, lub nplaum ntawm cov kab xev yuav dhau los ua ib hom paug uas nyuaj tshem. Hauv cov kuab tshuaj kub thiab kuab tshuaj vapors uas tsis muaj qhov sib txuam los yog tsis sib luag hauv dej, colloids tsim tau. Thermoplastic impregnant yuav nyob twj ywm rau saum npoo ntawm cov khoom tivthaiv, thiab lwm yam, uas ua rau tsim kom muaj cov pa phem.
3. Flux paug
Tom qab cov Cheebtsam PCB tau soldered, muaj ob hom kab mob sib kis rau ntawm lub substrate: ib qho yog tias cov khoom tsis huv hauv lub flux yog diffused los ntawm cov cam rau ntawm PCB, thiab lwm qhov yog cov paug ua rau ntawm PCB los ntawm flux nws tus kheej. Nws muaj peb hom flux: inorganic flux (suav nrog cov kua qaub inorganic, ntsev thiab cov roj inorganic, thiab lwm yam), rosin lossis resin-based organic flux, tsis-rosin lossis non-resin hom organic flux.
Lub flux sib txawv los ntawm cov hlau saum npoo mus rau oxide los ntawm kev ua kom lub cev thiab tshuaj, thaum txhawb txoj kev ntub dej ntawm cov hlau los ntawm cov kua ua kua. Thaum lub sijhawm cov txheej txheem no, cov dej paug tau hloov pauv mus rau tshuaj thiab mus tau rau hauv cov seem flux. Lub luag haujlwm ntawm rosin lossis resin-type welding khub yuav ua rau cov hlau oxide rau hauv rosinate lossis cov tshuaj ntxuav tes hlau. Yog tias lub halide tau siv los ua kev ua haujlwm ntawm rosin flux, ua cov pa sib xyaw ua ke ntawm cov dej-soluble inorganic thiab organic flux formulations, nws tuaj yeem hloov cov hlau oxides rau hlau halides. Yog li, cov tshuaj fluoride, chloride lossis hydroxide siv rau hauv cov txheej txheem flux tuaj yeem hloov ua kom zoo li qub tin, txhuas thiab tooj liab oxide rau chlorides. Cov tshuaj txhuam no yog ib qho muaj kuab paug ntau yam nyob hauv. Thaum flux seem los ua kev koom nrog hauv cov cam, tshwj xeeb tshaj yog cov vapor siab lub tebchaw, degassing tshwm sim nyob rau hauv kev txo qis, ua rau muaj ntau ntawm cov npuas thiab pob zeb, ua li no txo qhov zoo ntawm cov pob qij txha.