ECU Kho

                               BGA rework tshuab rau ECU kho

Tshiab tsim BGA rework tshuab rau ntau yam ECU kho, nws yog ib qho yooj yim mus siv lub rework tshuab,

Tab sis koj puas paub yuav ua li cas txheeb xyuas koj lub motherboard ua ntej kho, ntawm no yog 4 txoj hauv kev rau koj raws li hauv qab no:

1. Txheeb xyuas cov txheej txheem ntawm lub rooj tsavxwm

2. Txoj kev daws teeb meem

3. Txoj kev disassembly

4. Cov laj thawj tseem ceeb ntawm kev ua tsis tiav

Tam sim no, cia peb ua lawv cov ncauj lus kom ntxaws raws li hauv qab no:

1. Txheeb xyuas cov txheej txheem ntawm lub rooj tsavxwmkho ECU

1) Kev soj ntsuam txoj kev: seb puas muaj qhov kub hnyiab, hlawv tawm, blistering, tawg hlau ntawm lub rooj tsavxwm nto, corrosion ntawm lub qhov (socket) thiab dej nkag, thiab lwm yam.

2).Meter ntsuas txoj kev: ntxiv 5V, GND tsis kam yog tsawg dhau (hauv qab 50 ohms)

3). Kev tshuaj xyuas lub hwj chim: Rau lub rooj tsavxwm uas tau tawg meej meej, qhov hluav taws xob tuaj yeem nce me ntsis los ntawm 0.5-1V, thiab IC ntawm lub rooj tsavxwm tuaj yeem rub los ntawm tes tom qab lub hwj chim qhib , kom lub faulty nti yog rhuab thiab sensed.

4).Logic cwj mem tshuaj xyuas: Tshawb xyuas qhov muaj thiab lub zog ntawm cov teeb liab ntawm lub tswv yim, tso zis, thiab tswj cov ncej ntawm tus yuam sij ICs.

5) Txheeb xyuas qhov chaw ua haujlwm loj: Feem ntau lub rooj tsavxwm muaj kev faib tawm kom meej, xws li: cheeb tsam tswj (CPU), thaj tsam moos (crystal oscillator) (frequency division), thaj chaw duab hauv qab, thaj chaw ua haujlwm (cov cim, dav hlau), suab tiam thiab synthesis District, thiab lwm yam. Qhov no yog ib qho tseem ceeb heev rau kev saib xyuas ntawm lub computer board.

2. Txoj kev daws teeb meem

1). Rau qhov xav tias nti, raws li cov lus qhia ntawm phau ntawv qhia, thawj zaug xyuas seb puas muaj lub teeb liab (yoj qauv) ntawm cov tswv yim thiab cov zis tawm. Muaj qhov ua tau zoo, tsis muaj teeb liab tswj, taug qab mus rau nws cov ncej dhau los kom txog rau thaum pom IC puas lawm.kho ECU

2). Yog tias koj pom nws, tsis txhob tshem tawm ntawm tus ncej rau lub sijhawm. Koj tuaj yeem siv tib tus qauv. Los yog IC nrog tib cov ntsiab lus ntawm qhov kev zov me nyuam yog nyob tom qab, tig nws thiab saib seb nws puas txhim kho kom paub meej tias IC puas lawm.

3) Siv tangent thiab jumper txoj kev los nrhiav cov kab luv luv: Yog tias koj pom tias qee cov kab teeb liab thiab kab hauv av, ntxiv rau 5V lossis lwm tus pins uas yuav tsum tsis txhob txuas nrog IC yog luv luv, koj tuaj yeem txiav cov kab thiab ntsuas. dua los txiav txim seb nws puas yog IC teeb meem lossis teeb meem ntawm pawg thawj coj saib, lossis qiv cov cim los ntawm lwm cov ICs rau IC nrog cov waveform tsis ncaj ncees lawm kom pom tias cov duab tshwm sim zoo dua, thiab txiav txim siab qhov zoo ntawm IC.

4). Txoj kev sib piv: Nrhiav lub rooj tsavxwm zoo nrog cov ntsiab lus tib yam thiab ntsuas tus pin waveform thiab tus naj npawb ntawm cov IC sib raug kom paub meej tias IC puas.

5). Test IC nrog Microcomputer Universal Programmer IC TEST Software

3. Txoj kev disassemblykho ECU

1). Foot clipping method: Nws tsis ua mob rau lub rooj tsavxwm thiab tsis tuaj yeem rov ua dua.

2). Dragging tin txoj kev: Solder tag nrho cov tin ntawm ob sab ntawm IC ko taw, rub nws rov qab thiab rov qab nrog cov hlau kub kub, thiab tshem tawm IC tib lub sijhawm (lub rooj tsavxwm yooj yim rau kev puas tsuaj, tab sis IC tuaj yeem ua tau. kuaj yam xyuam xim).

3). Barbecue method: Barbecue on cawv teeb, roj qhov cub, hluav taws xob qhov cub, thiab tos kom txog thaum lub tin ntawm lub rooj tsavxwm melts kom tso IC (tsis yooj yim rau tswv).

4). Tin lauj kaub txoj kev: Ua ib lub lauj kaub tshwj xeeb ntawm lub qhov cub hluav taws xob. Tom qab lub tin yog yaj, muab tso rau hauv IC kom tshem tawm ntawm lub rooj tsavxwm mus rau hauv lub lauj kaub tin, thiab IC tuaj yeem nqa tau yam tsis muaj kev puas tsuaj rau lub rooj tsavxwm, tab sis cov khoom siv tsis yooj yim los ua.

5). Rework txoj kev: siv BGA rework macine tshav kub ib nti kom txog rau thaum nws cov tin melting tuaj tos nws rau reballing dua, soldering rov qab mus rau ib tug tshiab motherboard, rau kho vajtse kho, BGA rework tshuab yog ib qho tseem ceeb cov cuab yeej,

uas tuaj yeem siv tau li ntawm 10 xyoo, yog tias koj xav paub seb nws ua haujlwm li cas, ntawm no yog ib qho video rau koj siv raws li hauv qab no:

4. Qhov laj thawj tseem ceeb ntawm kev ua tsis tiav

1). Tib neeg tsis ua hauj lwm: plugging thiab unplugging I/O phaib nrog lub hwj chim rau, thiab kev puas tsuaj rau interfaces, chips, thiab lwm yam tshwm sim los ntawm kev quab yuam tsis zoo thaum txhim kho boards thiab plugs.

2). Ib puag ncig tsis zoo: hluav taws xob zoo li qub feem ntau ua rau cov chips (tshwj xeeb yog CMOS chips) ntawm lub motherboard kom tawg. Tsis tas li ntawd, thaum lub rooj tsav xwm tseem ceeb ntsib lub hwj chim tsis ua hauj lwm los yog ib qho hluav taws xob tsim los ntawm daim phiaj hluav taws xob ib ntus, nws feem ntau ua rau cov nti nyob ze ntawm lub hwj chim ntsaws ntawm lub rooj tsavxwm. Yog tias lub motherboard npog nrog plua plav, nws tseem yuav ua rau lub teeb liab luv luv thiab lwm yam.

3. Cov Teeb Meem Zoo: Kev puas tsuaj vim tsis zoo ntawm cov chips thiab lwm yam khoom siv. Thawj qhov uas yuav tsum nco ntsoov yog tias plua plav yog ib qho ntawm koj lub motherboard cov yeeb ncuab loj tshaj plaws.

Nws yog qhov zoo tshaj los tsom rau kev tiv thaiv plua plav. Plua plav ntawm lub motherboard tuaj yeem ua tib zoo txhuam los ntawm kev siv txhuam. Tsis tas li ntawd, qee daim npav motherboard thiab cov chips siv cov pins es tsis txhob ntawm cov slots, uas feem ntau ua rau kev sib cuag tsis zoo vim yog tus pin oxidation. Nrog rau kev siv cov kua nplaum, cov txheej oxide saum npoo tuaj yeem raug tshem tawm thiab rov kho dua. Qhov zoo tshaj plaws volatilization kev ua tau zoo yog ib qho kev daws teeb meem rau kev tu lub motherboard, yog li peb tuaj yeem siv trichloroethane. Nyob rau hauv cov kev tshwm sim ntawm ib qho kev npaj txhij txog fais fab tuag, lub computer yuav tsum tau kaw sai sai los tiv thaiv kev puas tsuaj rau lub motherboard thiab lub hwj chim mov. Yog tias overclocked vim yog qhov teeb tsa BIOS tsis raug, koj tuaj yeem pib dua thiab tshem lub jumper. Thaum lub BIOS tsis ua haujlwm, BIOS tuaj yeem hloov pauv los ntawm yam xws li kev cuam tshuam tus kab mob. Lub BIOS tsuas muaj nyob hauv software vim nws tsis tuaj yeem kuaj los ntawm lub ntsuas. Nws yog qhov zoo tshaj plaws los nyem lub motherboard BIOS txhawm rau txiav txim siab txhua qhov laj thawj ntawm qhov teeb meem motherboard. Tus tswv tsev tsis ua haujlwm tuaj yeem raug ntaus nqi rau ntau yam. Lub rooj tsav xwm tseem ceeb nws tus kheej ua tsis tau lossis ntau daim npav ntawm I / O lub npav tsis ua haujlwm, piv txwv li, tuaj yeem ua rau lub cev ua haujlwm tsis raug. Nws yog qhov yooj yim los txiav txim siab seb qhov teeb meem puas yog nrog I / O ntaus ntawv lossis motherboard los ntawm kev siv cov txheej txheem kho plug-in. Cov txheej txheem suav nrog kev xa tawm thiab tshem tawm txhua lub rooj tsav xwm plug-in ib tus zuj zus, tig lub tshuab thaum txhua lub rooj tsavxwm tau raug tshem tawm los xyuas nws txoj haujlwm. Qhov ua rau ntawm qhov tsis ua haujlwm yog qhov tsis ua haujlwm ntawm lub rooj tsavxwm plug-in lossis qhov cuam tshuam ntawm I / O lub npav thiab thauj khoom tsis ua haujlwm. Thaum ib lub rooj tsav xwm tshwj xeeb raug tshem tawm, lub rooj tsav xwm tseem ceeb ua haujlwm ib txwm. Tom qab tshem tawm tag nrho cov plug-in boards, yog tias lub kaw lus tseem tsis pib ib txwm, lub motherboard feem ntau yuav ua txhaum. Kev sib pauv txoj hauv kev yog qhov sib txawv ntawm qhov sib txawv plug-in boards, hom tsheb npav, plug-in boards nrog tib lub zog, lossis chips, thiab tom qab ntawd txheeb xyuas qhov teeb meem raws li kev hloov pauv hauv qhov tshwm sim txhaum.

Muaj feem xyuam kev paub txog reflowing:

Nyob rau hauv thaj chaw ntawm cov khoom siv hluav taws xob, cov txheej txheem soldering xws li reflow soldering thiab yoj soldering feem ntau yog siv.

Yog li dab tsi raws nraim yog reflow soldering?

Reflow soldering yog kev sib txuas ntawm cov khoom siv hluav taws xob thiab hluav taws xob sib txuas ntawm qhov chaw mount tiv thaiv kev txiav tawm lossis cov pins thiab cov ntaub ntawv luam tawm los ntawm remelting cov muab tshuaj txhuam zoo li cov nplaum ua ntej faib rau cov ntawv luam tawm.

Reflow soldering yog kev sib txuas ntawm cov khoom siv rau lub rooj tsav xwm PCB, uas yog rau cov khoom siv saum npoo av.

Los ntawm kev tso siab rau qhov kev txiav txim ntawm cov cua kub ntws ntawm cov pob qij txha, cov kua nplaum zoo li cov kua nplaum ua rau lub cev tawm tsam nyob rau hauv ib qho kev kub ntxhov cua kom ua tiav SMD (surface-mount device) vuam.

Yog vim li cas vim li cas nws thiaj li hu ua "reflow soldering" yog vim hais tias cov pa roj (nitrogen) circulates nyob rau hauv lub welding tshuab ua kom kub kub kom ua tiav lub hom phiaj ntawm vuam.

Txoj cai ntawm reflow soldering

Reflow soldering feem ntau muab faib ua plaub qhov chaw ua haujlwm: thaj chaw cua sov, thaj chaw khaws cua sov, thaj chaw vuam, thiab qhov chaw txias.

(1) Thaum lub PCB nkag mus rau hauv qhov cua sov, cov kuab tshuaj thiab cov roj hauv cov tshuaj txhuam cov tshuaj evaporate, thiab tib lub sijhawm, cov flux nyob rau hauv cov tshuaj txhuam tau ntub cov ntaub qhwv, cov terminals thiab cov pins, thiab cov tshuaj txhuam hniav softens, slumps, thiab npog Pad, uas cais lub ncoo, tivthaiv pins thiab oxygen.

(2) Lub PCB nkag mus rau hauv qhov chaw txuag hluav taws xob, kom cov PCB thiab cov khoom sib xyaw ua ke tau ua kom sov siab kom tiv thaiv PCB los ntawm kev nkag mus rau qhov kub thiab txias thiab ua rau PCB thiab cov khoom puas.

(3) Thaum lub PCB nkag mus rau hauv qhov chaw vuam, qhov kub thiab txias tau nce sai heev kom cov tshuaj txhuam hniav mus txog lub xeev molten, thiab cov kua nplaum ntub dej, diffuses, diffuses, los yog reflows cov ntaub qhwv, cov khoom xaus thiab cov pins ntawm PCB los tsim cov solder. pob qij txha.

(4) Lub PCB nkag mus rau hauv qhov chaw txias kom khov kho cov pob qij txha thiab ua kom tiav tag nrho cov txheej txheem reflow soldering.

Qhov zoo ntawm reflow soldering

Qhov kom zoo dua ntawm cov txheej txheem no yog qhov kub thiab txias tuaj yeem tswj tau yooj yim, oxidation tuaj yeem zam tau thaum lub sij hawm soldering, thiab cov nqi tsim khoom tuaj yeem tswj tau yooj yim dua.

Muaj cov cua sov hauv nws, uas ua rau cov roj nitrogen ua kom sov txaus thiab tshuab nws mus rau lub rooj tsav xwm hauv Circuit Court uas tau txuas nrog cov khoom, kom lub solder ntawm ob sab ntawm cov khoom melts thiab bonds nrog lub motherboard.

Thaum soldering nrog reflow soldering thev naus laus zis, tsis tas yuav muab tso rau hauv lub rooj tsav xwm luam tawm hauv molten solder, tab sis cov cua sov hauv zos yog siv los ua kom tiav cov haujlwm. Yog li ntawd, cov khoom yuav tsum tau soldered tau txais me ntsis thermal shock thiab yuav tsis tshwm sim los ntawm overheating. kev puas tsuaj rau lub cuab yeej.

Nyob rau hauv lub vuam tshuab, tsuas yog lub solder yuav tsum tau siv nyob rau hauv vuam ib feem thiab lub zos cua sov yuav tsum tau ua kom tiav cov vuam, yog li tsis txhob welding tsis xws luag xws li bridging.

Nyob rau hauv lub reflow soldering tshuab, lub solder yog ib-lub sij hawm siv thiab tsis muaj rov qab siv, yog li ntawd lub solder yog heev ntshiab thiab tsis muaj impurities, uas yuav xyuas kom meej qhov zoo ntawm solder pob qij txha.

Disadvantages ntawm reflow soldering

Qhov kub gradient tsis yooj yim rau tuav (qhov tshwj xeeb kub ntawm plaub qhov chaw ua haujlwm).

Taw qhia rau Reflow Soldering txheej txheem

Cov txheej txheem ntawm reflow soldering rau saum npoo mount boards yog qhov nyuaj dua.

Txawm li cas los xij, cov ntsiab lus luv luv tuaj yeem muab faib ua ob hom: ib sab mounting thiab ob sab mounting.

A. Single-sided mounting: pre-applied paste --> patch (divided into manual mounting and machine automatic mounting) --> reflow soldering -->kev tshuaj xyuas thiab kuaj hluav taws xob.

B. Double-sided mounting: Pre-applied paste paste on A side --> SMD (divided into manual mounting and automatic machine mounting) --> Reflow soldering --> Pre-applied paste paste on B side --> SMD- -> Reflow soldering -->Kev tshuaj xyuas thiab kuaj hluav taws xob.

The simplest process of reflow soldering is "screen printing solder paste" --> "patch" -->"reflow soldering", lub hauv paus ntawm uas yog qhov tseeb ntawm silk screen printing, thiab tus nqi tawm los yog txiav txim los ntawm PPM ntawm lub tshuab.

Reflow soldering yuav tsum tswj qhov kub thiab txias qhov siab tshaj plaws thiab qhov kub thiab txias nkhaus.