Ua kev daws teeb meem thiab kho rauPej xeemtuaj yeem txuas ntxiv lub neej ntawm cov voj voog. Yog hais tias ib tug faulty pcb tau ntsib thaum lub sij hawmPCB los ua keTxheej txheem, PCB pawg thawj coj tuaj yeem kho raws li qhov ntawm cov malfunction. Hauv qab no yog qee txoj hauv kev daws teeb meem thiab kho cov PCBs.
1. Yuav ua li cas ua kom tswj tau zoo ntawm PCB thaum lubCov txheej txheem tsim khoom?
Feem ntau, PCB me me muaj cov cuab yeej tshwj xeeb thiab cov txheej txheem tseem ceeb uas ua tau kev tswj hwm zoo ntawm kev tsim khoom lag luam.
1.1.AOI Soj Ntsuam
AOI tshuaj xyuas kom cov scans rau cov khoom siv uas tsis muaj lawm, tivthaiv mis nyuj sib xyaw, thiab lwm yam tsis xws luag ntawm PCB. AOI cov cuab yeej siv cov koob yees duab los ntes ntau cov duab ntawm PCB thiab muab piv nrog cov laug cam. Thaum lub suab tsis tau kuaj pom, nws tuaj yeem qhia tau qhov yuam kev.
1.2. Flying sojntsuam kuaj
Flying kev sim tshuaj ntsuam yog siv los txheeb xyuas luv luv thiab qhib cov kab sib chaws, cov khoom siv tsis yog (diodes thiab cov tsis muaj kev tiv thaiv. Ntau hom PCB tuaj yeem siv los kho cov luv luv thiab sib xyaw ua ke.
1.3.FCT sim
FCT (Kev Ntsuas Ntsuas) feem ntau yog tsom rau kev sim ua haujlwm ntawm PCBs. Cov ntsuas ntsuas ntsuas feem ntau yog muab los ntawm cov kws ua engineers thiab yuav suav nrog kev ntsuam xyuas kev hloov kho yooj yim. Hauv qee kis, cov software tshwj xeeb thiab muaj txiaj ntsig zoo. Ua haujlwm ntsuas ncaj qha tshuaj xyuas cov haujlwm ntawm PCB nyob rau hauv ib puag ncig ntiaj teb tiag tiag.
2. Raug ua rau PCB kev puas tsuaj
Nkag siab txog cov laj thawj ntawm PCB tsis tuaj yeem pab koj nrawm txheeb xyuas PCB ua txhaum. Ntawm no yog qee qhov yuam kev:
Txheej Txheem Tsis Txaus: Hloov kho cov khoom siv tsis tuaj yeem tso cai rau Circuit Court ua haujlwm kom zoo.
Overheating: Tsis muaj kev tswj kom sov, qee cov khoom siv yuav raug hlawv tawm.
Kev puas tsuaj lub cev: Qhov no feem ntau yog tshwm sim los ntawm kev tuav tuav,
Ua rau cov kab nrib pleb hauv Cheebtsam, cov pob qij txha sib dhos, cov npog ntsej muag, cov kab, thiab cov ntaub qhwv.
Tsis huv: Yog tias tus PCB raug cov mob hnyav, cov kab mob thiab lwm yam corroper tuaj yeem yog corroded.
3. Yuav ua li cas rau kev daws teeb meem PCb ua txhaum?
Cov npe hauv qab no yog 8 txoj hauv kev:
3-1. Nkag siab txog cov schematic
Muaj ntau ntau cov cheebtsam ntawm PCB, sib txuas los ntawm cov xov tooj tooj liab. Nws suav nrog hluav taws xob muab, hauv av, thiab ntau lub cim. Ib qho ntxiv, muaj ntau lub voj voog, xws li cov ntxaij lim dej, cov ntxaij hluav taws xob, cov khoom siv hluav taws xob tsis huv, thiab inductors. Nkag siab cov no yog qhov tseem ceeb rau kev kho PCB.
Paub txog yuav ua li cas lw txoj kev tam sim no thiab cais tawm cov neeg ua txhaum cai seem ntawm kev nkag siab txog lubPhab ntsa schematicCov. Yog tias tus schematic tsis muaj, nws yuav tsim nyog los thim rov qab tus encematic raws li PCB teeb.
3-2. Kev Saib Xyuas Kev Pom
Raws li tau hais ua ntej, overheating yog ib qho ntawm lub ntsiab ua rau PCB ua txhaum. Tej yam hlawv hluav taws xob, kab, lossis cov pob qij txha sib xyaw tuaj yeem txheeb xyuas tau yooj yim thaum tsis muaj lub hwj chim. Qee cov piv txwv ntawm cov tsis xws luag muaj xws li:
- BULGID / OVLAPPING / INSET COUNTS
- Txawb cov kab laum
- Txias pob qij qij
- Ntau ham
- Daim tawv nqaij daim tawv
- Nqa / ploj pads
- cov kab nrib pleb ntawm tus PCB
Tag nrho cov no tuaj yeem raug pom los ntawm kev tshuaj xyuas pom.
3-3. Piv nrog tus qauv PCB zoo ib yam
Yog tias koj muaj lwm tus PCB zoo ib yam nrog ib qho ua tau zoo thiab lwm yam yuam kev, nws yooj yim dua. Koj tuaj yeem visually sib piv, misalignments, thiab tsis xws luag nyob rau hauv cov kab lossis vias. Ib qho ntxiv, koj tuaj yeem siv ntau qhov ntau kom tshawb xyuas cov lus qhia thiab tso zis nyeem ntawm ob lub rooj tsavxwm. Qhov zoo sib xws yuav tsum tau txij li ob lub pcbs zoo tib yam.
3-4. Artolate faulty
Thaum pom kev tshuaj xyuas tsis yog txaus, koj tuaj yeem cia siab rau cov cuab yeej xws li motimeter lossis ib qhoMicretterCov. Ntsuam xyuas ib tus zuj zus raws li Datasheets thiab cov qauv tsim nyog. Piv txwv li resistors, capacitors, inductors, diodes, transisors, thiab leds.
Piv txwv li, koj tuaj yeem siv cov teeb tsa Diode ntawm ib tug loj los xyuas cov diodes thiab transistors. Lub hauv paus-collector thiab puag-emitter junctions ua li dodes. Rau cov board yooj yim board tsim qauv, koj tuaj yeem tshawb xyuas qhib thiab luv luv ntawm txhua qhov sib txuas. Tsuas yog teeb tsa lub ntsuas ntsuas kom tsis kam lossis txuas ntxiv hom thiab txuas mus rau kev sim txhua qhov kev sib txuas.
Thaum ua cov tshev, yog tias kev nyeem ntawv nyob rau hauv cov lus qhia tshwj xeeb, cov khoom siv yog suav tias yog ua haujlwm zoo. Yog tias kev nyeem ntawv yog txawv txav lossis siab dua qhov xav tau, tej zaum yuav muaj teeb meem nrog cov sib xyaw ua ke lossis cov pob qij txha sib dhos. Nkag siab txog qhov xav tau ntawm kev ntsuas cov ntsiab lus tuaj yeem pab tau hauv kev txheeb xyuas hluav taws xob.
Lwm txoj hauv kev rau kev ntsuas cov cheebtsam yog los ntawm kev tsom xam noodal. Hom no cuam tshuam nrog kev siv voltage rau cov xaiv xaiv thaum tsis muaj feem cuam tshuam tag nrho cov Circuit Court thiab ntsuas qhov ntsuas hluav taws xob (v-teb). Txheeb xyuas txhua lub nodes thiab xaiv cov siv txuas nrog cov khoom tseem ceeb lossis cov khoom siv hluav taws xob. Siv Kirchhoff cov kev cai tam sim no (KCl) los suav cov tsis paub txog voltages (hloov pauv) thiab txheeb xyuas yog cov txiaj ntsig no sib xws. Yog tias muaj teeb meem uas pom ntawm ib qho ntawm, nws qhia tau qhov txhaum ntawm cov ntawm no.
Kuaj cov khoom sib xyaw ua ke tuaj yeem yog ib txoj haujlwm ntau vim lawv cov nyom. Nov yog qee qhov kev kuaj uas tuaj yeem ua:
- Txheeb xyuas tag nrho cov cim thiab sim cov IC siv cov ntawv sau yuam kev lossis ib qhooscilloscope.
- Kuaj xyuas yog tias tus IC yog taw qhia kom raug.
- Xyuas kom meej tias txhua cov pob qij txheem solder txuas nrog IC yog qhov mob zoo.
- Ntsuas qhov mob ntawm txhua lub rhaub dej sov los yog thermal ncoo txuas nrog IC kom ntseeg tau cov cua sov.
3-6. Kev Kuaj Lub Hwj chim
Txhawm rau daws teeb meem hluav taws xob, nws yog qhov tsim nyog los ntsuas cov tsheb ciav hlau voltages. Kev nyeem ntawm voltmeter tuaj yeem cuam tshuam cov tswv yim thiab cov zis muaj nuj nqis ntawm cov khoom siv. Hloov pauv ntawm voltage tuaj yeem qhia cov teeb meem candcuit Court. Piv txwv li, nyeem ntawm 0V ntawm kev tsheb ciav hlau yuav qhia tau luv luv ntawm Circi hauv lub zog hluav taws xob, ua rau tiv thaiv overheating. Los ntawm kev sim ua kom muaj zog kev xeem thiab muab piv rau cov kev ntsuas ntsuas tiag tiag, cov teeb meem hluav taws xob tuaj yeem raug rho tawm.
3-7. Txheeb xyuas Raccuit Raccuit Rotspots
Thaum pom qhov tsis xws luag tsis pom, kev tshuaj xyuas lub cev los ntawm kev txhaj tshuaj tiv thaiv fais fab tuaj yeem siv los ntsuas qhov Circuit Court. Cov kev sib txuas tsis raug tuaj yeem tsim cov cua sov, uas tuaj yeem muaj kev cuam tshuam los ntawm kev tso ib sab tes ntawm Circuit Court board. Lwm txoj kev xaiv yog siv lub koob yees duab thermal ua ntej, uas feem ntau nyiam rau cov hluav taws xob tsawg. Tsim nyog kev nyab xeeb yuav tsum tau coj mus rau kev nruj hluav taws xob.
Ib txoj kev yog kom ntseeg tau tias koj siv ib txhais tes tsuas yog kuaj. Yog tias qhov chaw kub tau kuaj pom, nws yuav tsum tau txias, thiab tom qab ntawd tag nrho cov ntsiab lus sib txuas yuav tsum tau kuaj xyuas qhov teeb meem no.
3-8. Kev daws teeb meem nrog cov teeb liab cov txheej txheem
Txhawm rau siv cov txheej txheem no, nws yog qhov tseem ceeb heev kom muaj kev nkag siab txog cov kev cia siab thiab cov khoom siv waveforms ntawm cov ntsiab lus xeem. Kev kuaj hluav taws xob tuaj yeem ua tau ntawm ntau cov ntsiab lus siv tshuaj multimeter, oscilloscope, lossis ib qho khoom siv khiav ceev. Kev tshuaj xyuas cov txiaj ntsig tau tuaj yeem pab tau raws li kev raug.
4. Cov cuab yeej xav tau rauKev Kho Pcb
Ua ntej kev kho vaj tse, nws yog qhov tseem ceeb uas yuav sau cov cuab yeej tsim nyog rau txoj haujlwm, raws li cov lus hais mus, 'blunt riam yuav tsis txiav ntoo.'
● Cov ua haujlwm tau nruab nrog ESD av, cov khoom siv hluav taws xob, thiab teeb pom kev zoo yog qhov tseem ceeb.
● Los txwv cov cua sov, infrared cua sov lossis preheaters tej zaum yuav tsum tau ua kom preheat rau Circuit Court Board.
● Ib qhov drilling precision drilling system yog xav tau rau slotting thiab qhov qhib thaum lub sijhawm kho. Cov kab ke no tso cai tswj txoj kab uas hla thiab qhov tob ntawm cov pob.
● Cov hlau zoo soldering yog qhov tsim nyog rau soldering los xyuas kom meej cov pob qij txha tsim nyog.
● Ntxiv rau, hluav taws xob kuj tseem yuav tsum tau ua.
● Yog tias siv lub ntsej muag tawv me me yog puas, nws yuav tsum tau kho. Hauv cov xwm txheej zoo li no, ib txheej resin yog qhov zoo dua.
5. Kev ceev faj kev nyab xeeb thaum lub sijhawm kho PCB
Nws yog ib qho tseem ceeb kom siv kev tiv thaiv kev tiv thaiv kom tsis txhob muaj kev nyab xeeb thaum kho txheej txheem.
● Cov khoom tiv thaiv tiv thaiv: thaum nrog kev cuam tshuam nrog lub zog kub lossis muaj lub zog muaj zog, hnav cov khoom siv tiv thaiv yog qhov yuav tsum tau ua. Cov tsom iav kev nyab xeeb thiab hnab looj tes yuav tsum hnav thaum sib dhos thiab tho cov txheej txheem, kom tiv thaiv tawm tsam cov peev xwm kev phom sij.
Hnav cov hnab looj tes thaum kho cov PCBs.
● electrostatate tawm (ESD): Txhawm rau tiv thaiv kev ua kom hluav taws xob los ntawm ESD, nco ntsoov daws lub zog hluav taws xob thiab tso tawm cov hluav taws xob. Koj tuaj yeem tuaj yeem hnav cov pob zeb hauv av los yog siv cov mats qub qub kom txo qis kev pheej hmoo ntawm ESD.
6. Yuav kho tus PCB li cas?
Cov kev ua yuam kev hauv PCB feem ntau muaj kev tsis xws luag nyob rau hauv cov kab, Cheebtsam, thiab cov ntaub qhwv ntsej muag.
6-1. Kho cov kab mob uas puas
Txhawm rau kho cov tawg lossis cov kab mob puas ntawm tus PCB, siv lub ntsej muag ntse los ua rau thaj tsam ntawm cov thawj thiab tshem daim npog qhov ncauj. Ntxuav lub tooj liab saum npoo nrog cov kuab tshuaj kom tshem tawm cov khib nyiab, pab ua kom tiav kev txuas hluav taws xob ntxiv.
Xwb, koj tuaj yeem tuav jumper xaim los kho cov kab. Xyuas kom meej tias cov kab xoos voos yuam kev qhov trace dav rau kev ua haujlwm zoo.
Hloov cov khoom siv puas ntsoog
Txhawm rau tshem tawm cov khoom yuam kev lossis cov hlua khi ntau dua los ntawm cov yas pob qij txha, nws yog qhov tsim nyog los ua kom tsis txhob ua kom tsis txhob ua kom muaj kev ntxhov siab rau cov chaw ua hluav taws xob puag ncig. Tom qab cov kauj ruam hauv qab no los hloov cov khoom siv hauv Circuit Court:
● Ua kom cov pob qij txha sib tsoo sai sai uas siv cov hlau soldering lossis desoldering cuab yeej.
● Ib zaug solder tau melted, siv lub twj tso kua mis desodering kom tshem cov kua.
● Tom qab tshem tawm tag nrho cov sib txuas, cov tivthaiv yuav muaj kas cees.
● Tom ntej, sib sau ua ke rau cov tshiab tivthaiv thiab solder nws nyob rau hauv qhov chaw.
● Txiav qhov ntev tshaj ntawm cov txheej txheem ua siv hlau cutters.
● Xyuas kom paub meej tias cov lus txiav txuas txuas nrog raws li cov polarity xav tau.
6-3. Kho kho puas rab phom sib tsoo
Nrog rau lub sijhawm txav ntawm, cam cov ntaub qhwv ntawm tus PCB yuav nqa, corrode, lossis so. Ntawm no yog cov hau kev rau kev kho cov ntaub qhwv puas zoo:
Nqa cov phuam qhwv caj dab: Ntxuav thaj chaw nrog cov kuab tshuaj uas siv cov paj rwb paj rwb. Txhawm rau khi cov ncoo rov qab rau hauv qhov chaw, thov nrog cov ntaub qhwv thiab nias nws, tso cai rau cov txheej txheem Epoxy los kho ua ntej txuas ntxiv nrog cov txheej txheem soldering.
Puas los yog paug cov yeeb ncuab solder: Tshem tawm lossis txiav kom lub pob nyem puas, ua rau cov kab ke sib txuas los ntawm scraping tawm ntawm daim npog ntsej muag ib ncig ntawm pob. Ntxuav thaj chaw nrog cov kuab tshuaj siv cov paj rwb paj rwb. Ntawm tus tshiab solder ncoo (txuas nrog cov kab), thov ib txheej ntawm kev ua haujlwm epoxy cob thiab ruaj ntseg nws nyob rau hauv qhov chaw. Tom ntej no, ntxiv epoxy resin ntawm cov kab thiab cov cam ncoo. Kho nws ua ntej ua nrog cov txheej txheem soldering.
Shenzhen Anke PCB Co., Ltd
2023-7-20-20
Lub Sijhawm Post: Jul-21-2023
