Dab tsi yog cov teeb meem tshwm sim ntawm tooj liab plating tshuab hauv txheej txheem PCB? Txoj kev daws yog ...

Electroplating tooj liab yog feem ntau siv pre-txheej txheej los txhim kho lub zog sib txuas ntawm txheej. Cov txheej tooj liab yog ib feem tseem ceeb ntawm tooj liab / npib tsib xee / chromium system ntawm kev tiv thaiv zoo nkauj txheej. Lub adhesion thiab corrosion kuj ntawm cov coatings ua lub luag haujlwm tseem ceeb. Copper plating kuj tseem siv rau hauv zos los tiv thaiv carburization, metallization ntawm cov ntawv luam tawm qhov, thiab ua ib txheej txheej rau luam ntawv yob. Cov xim tooj liab txheej tom qab kho tshuaj, coated nrog cov yeeb yaj kiab organic, kuj tuaj yeem siv rau kev kho kom zoo nkauj. Hauv tsab xov xwm no, peb yuav qhia txog cov teeb meem tshwm sim hauv PCB txheej txheem ntawm electroplating tooj liab tshuab thiab lawv cov kev daws teeb meem.

1. Cov teeb meem tshwm sim ntawm cov kua qaub tooj liab electroplating

Copper sulfate electroplating occupies ib qho tseem ceeb heev txoj hauj lwm nyob rau hauv PCB electroplating. Qhov zoo ntawm cov kua qaub tooj liab electroplating ncaj qha cuam tshuam rau qhov zoo thiab muaj feem xyuam rau cov khoom siv hluav taws xob ntawm electroplated tooj liab txheej, thiab muaj qee yam cuam tshuam rau kev ua haujlwm tom ntej. Yog li ntawd, yuav ua li cas tswj qhov zoo ntawm cov kua qaub tooj liab electroplating yog ib qho tseem ceeb ntawm PCB electroplating, nws kuj yog ib qho ntawm cov txheej txheem nyuaj rau ntau lub tuam txhab loj los tswj cov txheej txheem. Cov teeb meem tshwm sim ntawm cov kua qaub tooj liab electroplating feem ntau suav nrog cov hauv qab no: 1. Rough electroplating; 2. Electroplating (board nto) tooj liab hais; 3. Electroplating pits; 4. Lub rooj tsavxwm saum npoo yog xim dawb lossis xim tsis sib xws. Hauv kev teb rau cov teeb meem saum toj no, qee cov ntsiab lus tau ua, thiab qee qhov kev tshuaj xyuas luv luv thiab kev tiv thaiv kev tiv thaiv tau ua tiav.

(1) Rough plating

Feem ntau, cov ces kaum ntawm lub rooj tsavxwm yog ntxhib, feem ntau yog tshwm sim los ntawm qhov loj electroplating tam sim no. Koj tuaj yeem txo qhov tam sim no thiab siv daim npav ntsuas hluav taws xob los xyuas seb cov zaub tam sim no puas txawv txav; Nyob rau hauv Ming Dynasty, qhov kub thiab txias tsis tshua muaj nyob rau lub caij ntuj no, thiab cov ntsiab lus ntawm lub teeb tus neeg sawv cev tsis txaus; thiab qee zaum qee qhov reworked thiab delaminated boards tsis tau ntxuav kom zoo, thiab cov xwm txheej zoo sib xws yuav tshwm sim.

(2) Copper nplej rau ntawm lub rooj tsavxwm electroplated

Muaj ntau ntau yam uas ua rau tooj liab hais rau ntawm lub rooj tsavxwm, los ntawm tooj liab tog mus rau tag nrho cov txheej txheem ntawm cov qauv hloov, thiab electroplating tooj liab nws tus kheej yog ua tau. Tus kws sau ntawv tau ntsib cov khoom tooj liab nyob rau ntawm lub rooj tsavxwm uas tshwm sim los ntawm kev tso cov tooj liab hauv lub tuam txhab loj hauv lub xeev.

Cov tooj liab hais rau ntawm lub rooj tsavxwm nto tshwm sim los ntawm cov txheej txheem tooj liab immersion yuav tshwm sim los ntawm ib qho ntawm cov txheej txheem tooj liab immersion. Alkaline degreasing yuav tsis tsuas yog ua rau roughness ntawm lub rooj tsavxwm, tab sis kuj roughness nyob rau hauv lub qhov thaum cov dej hardness siab thiab muaj ib tug ntau ntawm drilling plua plav (tshwj xeeb tshaj yog ob-sided vaj huam sib luag tsis muaj de-smear). Lub puab roughness thiab me ntsis taw tes-zoo li av ntawm lub rooj tsavxwm nto tuaj yeem raug tshem tawm los ntawm micro-etching; Feem ntau muaj ntau yam ntawm micro-etching: qhov zoo ntawm micro-etching tus neeg sawv cev hydrogen peroxide lossis sulfuric acid tsis zoo, lossis ammonium persulfate (sodium) muaj cov impurities siab dhau lawm, feem ntau nws tau pom tias yuav tsum yog tsawg kawg yog CP. qib, ntxiv rau qib kev lag luam, lwm yam kev ua tsis zoo yuav tshwm sim; tooj liab cov ntsiab lus ntawm micro-etching tank yog siab dhau los yog qhov kub thiab txias, ua rau qeeb los nag ntawm tooj liab sulfate crystals; lub tank kua yog turbid thiab polluted. Feem ntau ntawm kev ua kom muaj kuab paug yog tshwm sim los ntawm kev ua qias tuaj lossis kev saib xyuas tsis raug, xws li huab cua los ntawm lub twj tso kua mis lim, tsis tshua muaj lub ntiajteb txawj nqus ntawm lub tank kua, thiab cov ntsiab lus tooj liab siab (lub sij hawm ua kom lub tog raj kheej ua kom ntev dhau, ntau tshaj 3 xyoos. ), uas yuav tsim cov khoom uas raug tshem tawm hauv lub tank kua Los yog impurity colloids yog adsorbed rau ntawm lub phaj saum npoo los yog lub qhov phab ntsa, uas yuav tau nrog cov tiam ntawm roughness nyob rau hauv lub qhov. Degumming los yog acceleration: da dej tov yog pos huab tom qab siv ntev dhau lawm, vim hais tias feem ntau degumming daws yog tam sim no npaj nrog fluoroboric acid, thiaj li hais tias nws yuav tawm tsam cov iav fibers nyob rau hauv FR -4, ua rau kom cov silicate nce thiab calcium ntsev nyob rau hauv da dej. Tsis tas li ntawd, qhov nce ntawm tooj liab cov ntsiab lus thiab yaj tin nyob rau hauv da dej yuav ua rau tiam ntawm tooj liab hais nyob rau hauv lub board.

Cov tooj liab sinking tank nws tus kheej feem ntau yog tshwm sim los ntawm kev ua haujlwm ntau dhau ntawm cov kua tank, plua plav hauv huab cua nplawm, thiab ntau cov khoom me me raug tshem tawm hauv cov kua tank. kev daws teeb meem. Tom qab cov tooj liab tso tawm, lub dilute acid tank ntawm lub phaj tooj liab yuav tsum tau khaws cia ib ntus. Lub tank cov kua yuav tsum tau ceev kom huv si, thiab cov kua tank yuav tsum tau hloov nyob rau hauv lub sij hawm thaum nws yog huab. Lub sij hawm cia ntawm tooj liab immersion board yuav tsum tsis txhob ntev dhau lawm, txwv tsis pub lub board nto yuav yooj yim oxidized, txawm nyob rau hauv ib tug acidic tov, thiab cov oxide zaj duab xis yuav nyuaj dua rau tom qab oxidation, yog li ntawd tooj liab hais kuj yuav. generated ntawm lub rooj tsavxwm nto. Cov tooj liab nyob rau ntawm lub rooj tsavxwm nto tso los ntawm cov txheej txheem saum toj no-hais tooj liab sinking feem ntau faib sib npaug ntawm lub rooj tsavxwm tshwj tsis yog rau oxidation ntawm lub rooj tsavxwm, thiab qhov tsis tu ncua yog muaj zog, thiab cov pa phem tsim tawm ntawm no yuav ua rau tsis muaj teeb meem txawm tias nws. yog conductive los tsis. Rau tiam ntawm tooj liab hais nyob rau saum npoo ntawm electroplated tooj liab phaj, ib co me me kuaj boards yuav siv tau rau step-by-step tswj thiab kev txiav txim. Rau ntawm qhov chaw faulty board, nws yuav daws tau nrog ib tug mos txhuam. Nws tseem tuaj yeem raug plated thiab coated thaum lub sij hawm electroplating), los yog kev tu tom qab kev loj hlob tsis huv, los yog lub rooj tsavxwm tau muab tso rau ntev dhau lawm tom qab hloov cov qauv, uas ua rau txawv degrees ntawm oxidation ntawm lub rooj tsavxwm nto, tshwj xeeb tshaj yog yog hais tias lub rooj tsavxwm nto. ntxuav tsis zoo los yog khaws cia. Thaum huab cua paug hauv lub rooj cob qhia hnyav. Txoj kev daws teeb meem yog txhawm rau txhawm rau ntxuav, ntxiv dag zog rau kev npaj thiab sijhawm, thiab ntxiv dag zog rau lub zog ntawm acid degreasing.

Cov kua qaub tooj liab electroplating tank nws tus kheej, thiab nws cov pretreatment nyob rau lub sij hawm no, feem ntau yuav tsis ua rau tooj liab hais nyob rau hauv lub board nto, vim hais tias cov uas tsis yog-conductive hais ua rau cov feem ntau leakage plating los yog pits ntawm lub board nto. Cov laj thawj yog vim li cas lub tog raj kheej tooj liab ua rau tooj liab nyob rau ntawm lub rooj tsavxwm tuaj yeem piav qhia txog ntau yam: kev saib xyuas ntawm cov dej da dej, kev ua haujlwm ntau lawm, cov khoom siv thiab cov txheej txheem tu. Kev saib xyuas ntawm da dej tsis suav nrog cov ntsiab lus sulfuric acid siab, cov ntsiab lus tooj liab tsawg dhau, thiab chav da dej kub tsawg lossis siab, tshwj xeeb tshaj yog nyob rau hauv cov chaw ua haujlwm uas tsis muaj qhov kub thiab txias. Lub sijhawm no, qhov tam sim no qhov ntom ntom ntawm chav da dej yuav txo qis. Raws li cov txheej txheem ntau lawm, cov hmoov tooj liab tuaj yeem tsim hauv da dej thiab sib xyaw rau hauv da dej;

Nyob rau hauv cov nqe lus ntawm kev lag luam ntau lawm, tam sim no loj heev, lub splint yog phem, lub npliag pinch point, ntog phaj nyob rau hauv lub tank yog yaj tawm tsam anode, thiab lwm yam, uas yuav ua rau tam sim no ntawm ib co boards loj heev. , ua rau tooj liab hmoov, poob rau hauv lub tank, thiab maj mam ua tooj liab hais tsis ua hauj lwm. Cov khoom siv feem ntau yog hais txog cov ntsiab lus phosphorus ntawm phosphor tooj liab fab thiab qhov sib xws ntawm phosphorus faib; ntau lawm thiab kev txij nkawm yog feem ntau hais txog kev ua haujlwm loj, thaum lub kaum sab xis tooj liab ntxiv rau hauv lub tank, feem ntau yog thaum ua haujlwm loj, anode tu thiab anode hnab tu, ntau lub Hoobkas Yog tias nws tsis ua haujlwm zoo, muaj qee qhov kev phom sij zais. Rau kev kho pob tooj liab loj, qhov chaw yuav tsum tau ntxuav, thiab cov tooj liab tshiab yuav tsum tau etched me ntsis nrog hydrogen peroxide. Lub hnab anode yuav tsum tau tsau nrog sulfuric acid hydrogen peroxide thiab lye, thiab ntxuav, tshwj xeeb tshaj yog lub hnab anode yuav tsum yog PP lim hnab nrog qhov sib txawv ntawm 5-10 microns. .

3. Electroplating qhov

Tseem muaj ntau cov txheej txheem tshwm sim los ntawm qhov tsis xws luag, los ntawm tooj liab sinking, qauv hloov mus rau pre-plating, tooj liab plating thiab tin plating. Qhov laj thawj tseem ceeb ntawm tooj liab dab dej yog kev tu tsis zoo ntawm lub dab dej tooj liab dai pob tawb rau lub sijhawm ntev. Thaum lub sij hawm micro-etching, cov tshuaj tiv thaiv kab mob uas muaj palladium thiab tooj liab yuav poob los ntawm lub pob tawb dai rau ntawm lub rooj tsavxwm, ua rau muaj kuab paug thiab ua rau qhov chaw tawm tom qab tooj liab lub tog raj kheej tau hluav taws xob. lub qhov. Cov txheej txheem kev hloov duab nraaj feem ntau yog tshwm sim los ntawm kev saib xyuas cov khoom siv thiab kev txhim kho tsis zoo thiab tu. Muaj ntau yam laj thawj: cov txhuam hniav ntawm lub tshuab txhuam hniav yog cov kab mob ntawm cov kua nplaum, cov cua riam ntxuam hauv cov tshuab ziab khaub ncaws yog qias neeg, thiab muaj cov plua plav roj, thiab lwm yam, thiab lub rooj tsavxwm yog them nrog zaj duab xis lossis plua plav ua ntej luam ntawv. Tsis tsim nyog, lub tshuab tsim tawm tsis huv, kev ntxuav tsis zoo tom qab kev loj hlob, thiab cov silicon-muaj defoamer paug rau lub rooj tsavxwm nto, thiab lwm yam. Kev kho ua ntej ntawm electroplating, vim tsis muaj teeb meem nws yog acid degreaser, micro-etching, pre- dipping, lub ntsiab tseem ceeb ntawm cov kua da dej yog sulfuric acid, yog li thaum cov dej hardness siab, nws yuav tshwm sim turbid thiab pollute lub board nto; Tsis tas li ntawd, qee lub tuam txhab muaj cov kua nplaum tsis zoo, rau lub sijhawm ntev, nws yuav pom tias cov encapsulation yuav yaj thiab diffuse nyob rau hauv lub tank hmo ntuj, paug cov kua tank; Cov khoom uas tsis yog-conductive no yog adsorbed rau saum npoo ntawm lub rooj tsavxwm, uas yuav ua rau muaj kev sib txawv ntawm electroplating pits rau tom ntej electroplating.

4. Lub rooj tsavxwm nto yog dawb los yog xim tsis sib xws

Cov kua qaub tooj liab electroplating tank nws tus kheej tej zaum yuav muaj cov nram qab no: cov cua tshuab raj deviates los ntawm tus thawj txoj hauj lwm, thiab cov huab cua tsis sib npaug zos stirred; lub twj tso kua mis lim dej los yog cov kua dej nkag yog ze rau cov cua tshuab raj kom nqus tau cov pa, ua rau cov cua npuas zoo, uas yog adsorbed rau ntawm lub rooj tsavxwm nto los yog ntug ntawm txoj kab. Tshwj xeeb tshaj yog nyob rau ntawm kab rov tav thiab kaum ntawm kab; tej zaum yuav muaj lwm cov ntsiab lus hais tias kev siv cov paj rwb tsis zoo, kev kho mob tsis zoo, cov tshuaj tiv thaiv zoo li qub uas siv rau hauv cov txheej txheem ntawm cov paj rwb core tsim cov kab mob paug cov kua dej da dej, ua rau cov dej xau, qhov teeb meem no tuaj yeem ua rau cua tshuab thiab ntxuav cov kua nplaum ua npuas ncauj hauv lub sijhawm. Tom qab cov paj rwb core yog ntub nrog cov kua qaub thiab alkali, cov xim ntawm lub board nto yog dawb los yog tsis sib xws: feem ntau yog vim muaj teeb meem ntawm polishing tus neeg saib xyuas lossis kev saib xyuas, thiab qee zaum nws yuav yog qhov teeb meem ntawm kev tu tom qab acid degreasing. Micro-etching teeb meem. Cov tooj liab lub tog raj kheej polishing tus neeg sawv cev yog tawm ntawm qhov sib npaug, cov organic muaj kuab paug hnyav, thiab da dej kub siab dhau. Acid degreasing feem ntau tsis ua rau muaj teeb meem kev tu, tab sis yog tias tus nqi pH ntawm cov dej yog acidic heev thiab muaj ntau cov organic tshuaj, tshwj xeeb tshaj yog rov ua dua thiab rov ua dej ntxuav, nws yuav ua rau kev tu tsis zoo thiab tsis sib xws micro-etching; micro-etching feem ntau txiav txim siab cov ntsiab lus ntau dhau ntawm micro-etching cov neeg ua haujlwm qis, cov ntsiab lus tooj liab hauv cov tshuaj micro-etching yog siab dhau, thiab qhov kub ntawm cov tshuaj da dej yog tsawg, thiab lwm yam, uas yuav ua rau tsis sib xws ntawm micro-etching. board nto; Tsis tas li ntawd, kev ntxuav cov dej tsis zoo, lub sij hawm ntxuav me ntsis ntev dua, los yog cov kua qaub ua ntej cov kua qaub yog cov kuab paug, thiab cov board nto yuav raug kho tom qab kev kho mob. Yuav muaj oxidation me ntsis. Thaum lub tank tooj liab yog electroplated, vim hais tias nws yog acid oxidation thiab lub rooj tsavxwm raug them rau hauv lub tank, cov oxide yog ib qho nyuaj rau tshem tawm, uas yuav ua rau cov xim tsis sib xws ntawm lub rooj tsavxwm; Tsis tas li ntawd, lub rooj tsavxwm nto hu rau lub hnab anode, thiab lub anode coj tsis ncaj. , anode passivation, thiab lwm yam kuj tuaj yeem ua rau muaj qhov tsis xws luag.