Hauv cov txheej txheem pcb tsim thiab sib dhos, kev siv tshuab tu yog qhov txuas tseem ceeb los xyuas kom meej cov khoom ua tau zoo thiab kev ntseeg tau. Txawm hais tias nws yog qhov seem tu tom qab ua cov txheej txheem substrate thiab etching, los yog tshem tawm cov kua nplaum tom qab vuam, cov khoom seem uas tshuav los ntawm kev ntxuav tsis tiav yuav ua rau muaj teeb meem zoo thiab tseem cuam tshuam rau lub sijhawm ntev - lub sijhawm ua haujlwm ruaj khov ntawm cov khoom siv davhlau ya nyob twg. Yog li ntawd, kev tshawb nrhiav qhov seem tom qab pcb board tu tau dhau los ua ib qho tseem ceeb ntawm kev tswj cov khoom zoo thiab tsis txhob muaj kev pheej hmoo.
1, Kev phom sij ntawm pcb board residue: ib qho kev phom sij zoo uas tsis tuaj yeem tsis quav ntsej
Cov khoom seem tom qab ntxuav tej zaum yuav muaj kab mob, tab sis lawv tuaj yeem muaj ntau qhov cuam tshuam rau kev ua haujlwm hluav taws xob, kev ntseeg tau ntawm cov neeg kho tshuab, thiab kev hloov pauv ib puag ncig ntawm cov ntawv luam tawm. Cov kev phom sij tshwj xeeb yog tshwm sim hauv peb yam hauv qab no:
Ua ntej, muaj hluav taws xob ua haujlwm tsis ua haujlwm. Cov khoom seem ionic, xws li cov tshuaj chloride ions hauv etching kev daws teeb meem thiab cov organic acid ions hauv soldering flux, tuaj yeem tsim txoj hauv kev hauv qhov chaw ntub dej, ua rau txo qis hauv rwb thaiv tsev ntawm lub pcb nto, muaj zog xau tam sim no, teeb liab crosstalk, thiab txawm tias luv luv thiab Circuit Court tivthaiv burnout nyob rau hauv cov xwm txheej hnyav. Cov tsis muaj ionic residues (xws li roj thiab cov khib nyiab khib nyiab) tuaj yeem npog qhov chaw ntawm cov kab sib kis lossis cov ntaub qhwv, ua rau cov teeb liab tsis zoo, thiab cuam tshuam kev cuam tshuam kev cuam tshuam, tshwj xeeb tshaj yog nyob rau hauv siab - zaus thiab siab - ceev luam ntawv Circuit Court boards, qhov uas cov residues muaj qhov cuam tshuam loj dua ntawm cov teeb liab kev ncaj ncees.
Qhov thib ob, muaj qhov txo qis hauv kev ntseeg siab ntawm cov neeg kho tshuab. Cov khoom seem yuav ua rau kev sib txuas ntawm cov khoom sib txuas ntawm pcb thiab cov khoom. Piv txwv li, residual flux tuaj yeem corrode solder pob qij txha, ua rau txo qis hauv kev sib koom ua ke. Nyob rau hauv ib puag ncig kev ntxhov siab xws li kev vibration thiab kub caij tsheb kauj vab, cov pob qij txha tuaj yeem ua rau tawg, ua rau kev sib txuas tsis ua haujlwm. Tsis tas li ntawd, residual viscous tshuaj kuj tseem adsorb plua plav thiab impurities, uas tuaj yeem ua rau lub sijhawm ntev thiab cuam tshuam rau kev ua haujlwm ntawm cov khoom siv hluav taws xob ntawm cov khoom siv hluav taws xob, ua kom cov khoom lag luam nrawm nrawm.
Thaum kawg, ib puag ncig adaptability tau deteriorated. Nyob rau hauv ib puag ncig hnyav xws li kub siab, high humidity, thiab ntsev tsuag, residual corrosive tshuaj yuav leeb lub oxidation thiab corrosion ntawm pcb substrates thiab tooj liab foils, shortening cov khoom lub neej kev pab cuam. Piv txwv li, yog tias muaj cov chloride residual ions nyob rau hauv cov ntawv luam tawm Circuit Court boards nyob rau hauv marine ib puag ncig, nws tuaj yeem ua rau cov hluav taws xob hluav taws xob hnyav thiab ua rau cov hluav taws xob tawg, uas yuav ua rau muaj kev puas tsuaj rau cov ntawv luam tawm Circuit Court boards hauv aerospace, automotive electronics, thiab lwm yam.
2, Lub ntsiab hom thiab qhov chaw ntawm pcb board residues
Kev qhia meej txog hom thiab qhov chaw ntawm cov khoom seem yog qhov yuav tsum tau ua ua ntej rau kev xaiv cov txheej txheem tshawb nrhiav kom raug thiab nrhiav qhov teeb meem kom raug. Raws li cov khoom siv tshuaj thiab cov txheej txheem tsim khoom, cov khoom seem tom qab pcb tu tuaj yeem muab faib ua peb pawg hauv qab no:
(1) Ionic residue
Ionic residues feem ntau yog muab los ntawm kev siv tshuaj lom neeg thiab muaj zog solubility thiab conductivity, uas yog lub ntsiab ua rau hluav taws xob tsis ua hauj lwm. Cov hom muaj xws li: residual chlorides, fluorides, thiab sulfates (los ntawm etching tov) tom qab etching txheej txheem; Organic acid ions (xws li rosin acid thiab carboxylate) tsim los ntawm decomposition ntawm flux tom qab vuam txheej txheem; Residual hlau ions (xws li tooj liab ions, tin ions) tom qab electroplating txheej txheem. Hom residue no yooj yim adsorbed rau ntawm qhov chaw lossis qhov khoob ntawm pcb. Yog tias tsis tau muab tshem tawm kom zoo los ntawm kev tu cov pa, ions yuav raug tso tawm thaum lub sij hawm hloov cov av noo, uas tuaj yeem ua rau cov rwb thaiv tsev ua tau zoo.
(2) Tsis muaj ionic residue
Tsis yog ionic residues feem ntau yog tsim los ntawm cov organic thiab tsis muaj conductivity, tab sis lawv tuaj yeem cuam tshuam rau cov yam ntxwv saum npoo thiab kev sib koom ua ke ntawm cov ntawv luam tawm Circuit Board. Feem ntau suav nrog: cov residual tso cov neeg ua haujlwm thiab cov khib nyiab pov tseg thaum ua cov txheej txheem substrate; Cov kuab tshuaj residual siv los ntxuav cov txheej txheem (xws li cawv thiab ketone cov kuab tshuaj); Rosin resin, wax Cheebtsam, thiab lwm yam hauv flux. Cov uas tsis yog ionic residues feem ntau yog nkig heev thiab yooj yim ua raws li qhov chaw ntawm cov ntaub qhwv thiab cov kab sib kis. Tej zaum lawv yuav tsis tsuas yog cuam tshuam rau cov txheej txheem sib dhos tom ntej (xws li qhov tsis raug ntawm qhov chaw nyob hauv SMT), tab sis tseem cuam tshuam cov cua sov dissipation thiab ua kom kub hauv zos nce.
(3) Granular residue
Granular residues muaj rau lub cev impurities nrog ntau qhov chaw, suav nrog substrate plua plav thiab tooj liab foil khib nyiab tsim thaum lub sijhawm tsim khoom pcb; Plua plav thiab fibers hauv ib puag ncig; Fiber ntau los ntawm txhuam thiab lim paj rwb thaum lub sij hawm ntxuav. Yog hais tias cov residues adhere ntawm cov ntaub qhwv los yog cov pins, lawv yuav ua rau cov khoom siv virtual thiab kev sib cuag tsis zoo; Yog hais tias nws nkag mus rau sab hauv ntawm precision Cheebtsam xws li chips thiab capacitors, nws kuj yuav ua rau cov neeg kho tshuab tsis ua hauj lwm, tshwj xeeb tshaj yog rau cov me me thiab siab -cov ntawv luam tawm Circuit Court boards.
3, Cov thev naus laus zis thev naus laus zis thiab daim ntawv thov scenarios ntawm pcb residual nrhiav kom tau
Rau ntau hom residues, kev lag luam tau tsim ntau yam kev paub txog kev paub tab, txhua tus muaj nws tus kheej zoo hauv kev tshawb nrhiav qhov tseeb, kev ua tau zoo, thiab cov xwm txheej siv tau. Kev sib tw yuav tsum tau xaiv raws li qhov xav tau tiag tiag.
(1) Ionic chromatography: paub meej ntawm ionic residues
Ion chromatography yog "tus qauv kub" rau kev kuaj cov ionic residues. Cov ions seem yog sib cais los ntawm kab sib cais thiab tom qab ntawd txheeb xyuas qhov ntau ntawm ion concentration siv lub ntsuas ntsuas (xws li lub ntsuas hluav taws xob). Nws tuaj yeem txheeb xyuas ntau yam ions xws li chloride ions thiab cov organic acid radicals, nrog rau kev kuaj pom txog li ppm lossis txawm ppb.
Qhov zoo ntawm cov thev naus laus zis no yog nyob rau hauv nws cov kev sib xyaw ua ke ntawm cov txheej txheem zoo thiab ntau. Nws tuaj yeem tsis tsuas yog txiav txim siab txog hom ions seem, tab sis kuj suav cov nyiaj seem seem, ua kom nws tsim nyog rau kev tswj xyuas zoo hauv cov xwm txheej hnyav xws li aerospace thiab cov cuab yeej siv kho mob luam tawm Circuit Board. Thaum kuaj, nws yog ib qho tsim nyog yuav tsum xub muab cov ionic residues nyob rau saum npoo ntawm pcb siv cov tshuaj extraction (xws li dej deionized), thiab tom qab ntawd ua cov tshuaj chromatographic ntawm cov tshuaj extraction. Txawm li cas los xij, txoj kev no yog qhov nyuaj rau kev khiav lag luam thiab muaj lub voj voog tshawb nrhiav ntev (kwv yees li 1-2 teev rau ib qho kev sim), ua rau nws tsim nyog rau kev kuaj batch sampling ntau dua li kev sim online ntawm lub sijhawm.
(2) Fourier hloov pauv infrared spectroscopy: kev soj ntsuam zoo ntawm cov tsis yog -ionic residues
Fourier transform infrared spectroscopy txiav txim siab cov qauv tshuaj ntawm cov khoom seem los ntawm kev tshuaj xyuas lawv cov infrared absorption spectra, thiab tom qab ntawd txheeb xyuas cov hom tsis yog -ionic residues (xws li rosin resin thiab hnyav residues). Lub hauv paus ntsiab lus yog tias cov pab pawg ua haujlwm ntawm cov organic sib txawv, xws li hydroxyl, carbonyl, thiab benzene rings, nqus cov wavelengths ntawm lub teeb infrared. Los ntawm kev sib piv nrog lub tsev qiv ntawv spectral txheem, cov khoom seem yuav raug txheeb xyuas sai.
Qhov kom zoo dua ntawm FTIR yog nyob rau hauv nws txoj kev tshawb nrhiav ceev ceev (kwv yees li 5-10 feeb ib qho kev kuaj pom), tsis tas yuav rhuav tshem cov qauv, thiab tsim nyog rau kev soj ntsuam zoo ntawm cov tsis-ionic residues. Piv txwv li, yog tias rosin tus yam ntxwv nqus lub ncov pom nyob rau saum npoo ntawm pcb thaum kuaj, nws tuaj yeem txiav txim siab tias cov khoom siv hluav taws xob tsis tau raug tshem tawm tag nrho. Txawm li cas los xij, txoj kev no muaj qhov tseeb tsawg thiab tsis tuaj yeem suav cov nyiaj seem seem. Nws feem ntau yog siv los ua ib txoj kev tshawb nrhiav ua ntej thiab ua ke nrog lwm cov tswv yim (xws li txoj kev hnyav) kom ua tiav qhov kev soj ntsuam ntau.
(3) Optical microscope thiab scanning electron microscope: pom pom cov seem seem
Optical microscope and scanning electron microscope are the main tools for observing particulate residues. The former is suitable for rapid detection of larger particles (particle size>10 μ m), thaum tom kawg tuaj yeem soj ntsuam micrometer lossis txawm tias nanometer qhov loj me. Nws tseem tuaj yeem txheeb xyuas cov ntsiab lus ntawm cov khoom los ntawm lub zog spectrometer los txiav txim qhov chaw ntawm cov khoom seem (xws li cov khib nyiab tooj liab thiab fiber ntau).
Optical microscope yog ib qho yooj yim rau kev khiav lag luam thiab tus nqi -zoo, haum rau kev tshuaj ntsuam online ceev ntawm cov kab ntau lawm. Nws tuaj yeem ua tiav batch pcb particle nrhiav tau los ntawm cov cuab yeej siv tshuab; SEM yog qhov tsim nyog rau qhov siab - qhov tseeb qhov xwm txheej, xws li kuaj pom cov khoom zoo ntawm qhov chaw ntawm cov ntawv luam tawm me me, lossis tshuaj xyuas qhov muaj pes tsawg leeg thiab qhov chaw ntawm cov khoom, muab lub hauv paus rau kev txhim kho cov txheej txheem tu. Txawm li cas los xij, cov cuab yeej SEM muaj cov nqi siab dua thiab qis dua kev tshawb nrhiav, ua rau nws tsim nyog rau kev daws teeb meem nyuaj thiab txhim kho cov txheej txheem.
(4) Surface Insulation Resistance Test: Indirect Evaluation of Residual Effects
Txawm hais tias qhov kev ntsuam xyuas qhov hluav taws xob tsis ncaj qha tsis tuaj yeem txheeb xyuas hom thiab cov ntsiab lus ntawm cov khoom seem, nws tuaj yeem ntsuas qhov cuam tshuam ntawm cov khoom seem ntawm hluav taws xob los ntawm kev ntsuas qhov rwb thaiv tsev ntawm ob lub ntsiab lus ntawm pcb nto. Txoj kev no simulates qhov siv tiag tiag ib puag ncig (xws li kub thiab av noo ib puag ncig), tso lub pcb nyob rau hauv tej yam kub thiab av noo tej yam kev mob, siv ib tug tej yam voltage, thiab saib xyuas cov kev hloov ntawm rwb thaiv tsev kuj: yog hais tias tus kuj tseem txo qis, nws qhia tau hais tias cov residual tshuaj tso tawm ions thiab muaj kev pheej hmoo ntawm rwb thaiv tsev tsis ua hauj lwm.
Qhov kom zoo dua ntawm SIR kuaj yog tias nws nyob ze rau qhov ua tau zoo ntawm daim ntawv thov scenarios thiab muaj peev xwm intuitively cuam tshuam qhov cuam tshuam ntawm residues ntawm cov khoom ntseeg tau, ua rau nws tsim nyog raws li ib tug zoo pov thawj txoj kev. Txawm li cas los xij, txoj kev no tsis tuaj yeem txiav txim siab txog yam tshwj xeeb ntawm qhov seem thiab yuav tsum tau ua ke nrog lwm cov kev tshawb nrhiav kom paub ntxiv txog qhov laj thawj ntawm qhov teeb meem.
Kev tshawb pom qhov seem tom qab pcb board tu yog "kab kawg ntawm kev tiv thaiv" kom ntseeg tau cov khoom lag luam, thiab nws cov txheej txheem ncaj qha cuam tshuam rau qhov zoo thiab daim ntawv thov kev nyab xeeb ntawm cov ntawv luam tawm Circuit Board. Nrog rau kev txhim kho ntawm pcb mus rau qhov siab ceev, miniaturization, thiab kev ntseeg siab, kev tshawb nrhiav seem yuav tsum sib npaug ntau dua qhov tseeb thiab ua haujlwm tau zoo. Nyob rau hauv lub neej yav tom ntej, yuav muaj ob lub ntsiab lus tseem ceeb: ntawm ib sab, kev tshawb nrhiav thev naus laus zis yuav raug hloov kho rau automation thiab kev txawj ntse (xws li cov cuab yeej tshawb nrhiav hauv online ion chromatography, uas tuaj yeem ua tiav tiag - lub sijhawm saib xyuas thiab lub tswb tsis siv neeg); Ntawm qhov tod tes, cov txheej txheem tshawb nrhiav thiab ntxuav yuav sib xyaw ua ke, nrog rau qhov tseeb - lub sijhawm tawm tswv yim ntawm cov ntaub ntawv tshawb pom thiab kev hloov pauv hloov pauv ntawm kev ntxuav tsis tu ncua, ua tiav qhov kaw - voj tswj ntawm "nrhiav optimization re detection".