Hais txog PCB layout thiab teeb meem thaiv, hnub no peb yuav tsis tham txog teeb meem kev ntseeg siab (SI), electromagnetic compatibility tsom xam (EMC), lub hwj chim integrity tsom xam (PI). Tsuas yog tham txog kev tsim khoom lag luam (DFM), cov qauv tsis tsim nyog ntawm cov tuam ntxhab tseem yuav ua rau tsis ua haujlwm ntawm cov khoom tsim.
Kev ua tiav DFM hauv PCB layout pib nrog kev teeb tsa cov cai tsim los suav rau cov kev txwv tseem ceeb DFM. DFM cov cai hauv qab no qhia txog qee qhov kev tsim qauv niaj hnub no uas feem ntau cov tuam ntxhab tuaj yeem pom. Xyuas kom meej tias cov kev txwv uas tau teev tseg hauv PCB cov kev cai tsim tsis ua txhaum lawv kom cov kev txwv tsim qauv feem ntau tuaj yeem ua kom ntseeg tau.
DFM qhov teeb meem ntawm PCB kev ib txwm nyob ntawm qhov kev coj ua zoo pcb, thiab cov kev coj ua, suav nrog cov kauj ruam, thiab lwm yam yog nqa tawm ua ntej kom txuas cov kab luv luv, thiab tom qab ntawd txoj kab hluav taws xob labyrinth yog nqa tawm. Cov kev taug kev hauv ntiaj teb yog nqa tawm ntawm cov xov hlau yuav tau tso ua ntej, thiab rov muab hlau ua ntej tau sim txhawm rau txhim kho cov nyhuv tag nrho thiab dfm chaw ua haujlwm.
1.SMT cov khoom siv
Qhov sib txawv ntawm cov cuab yeej ua tau raws li qhov yuav tsum tau ua los ua ke, thiab feem ntau ntau dua 20mil rau cov khoom siv saum npoo av, 80mil rau IC li, thiab 200mi rau BGA li. Txhawm rau txhim kho qhov zoo thiab cov txiaj ntsig ntawm cov txheej txheem ntau lawm, cov cuab yeej sib txuas tuaj yeem ua tau raws li qhov yuav tsum tau ua los ua ke.
Feem ntau, qhov kev ncua deb ntawm SMD ncoo ntawm lub cuab yeej pins yuav tsum muaj ntau dua 6mil, thiab lub peev xwm fab ntawm cov tub choj solder yog 4mil. Yog tias qhov kev ncua deb ntawm SMD Pads yog tsawg dua 6Mil thiab qhov kev ncua deb ntawm cov hlua khi tsawg dua 4mil, tshwj xeeb tshaj yog cov pins (tshwj xeeb ntawm cov pins) hauv cov txheej txheem sib dhos, uas yuav ua rau luv luv Circuit Court.
2.DIP ntaus ntawv
Tus pin spacing, kev taw qhia thiab qhov sib nrug ntawm cov khoom siv hauv cov txheej txheem dhau yoj soldering yuav tsum raug coj mus rau hauv tus account. Tsis txaus tus pin qhov sib nrug ntawm lub cuab yeej yuav ua rau cov hlau nplaum, uas yuav ua rau luv luv.
Ntau tus neeg tsim qauv txo qis kev siv cov khoom siv hauv kab (THTS) lossis muab tso rau tib sab ntawm lub rooj tsavxwm. Txawm li cas los xij, cov khoom siv hauv kab feem ntau tsis tuaj yeem zam tau. Nyob rau hauv cov ntaub ntawv ntawm kev sib xyaw ua ke, yog tias cov cuab yeej hauv-kab tau muab tso rau saum txheej txheej thiab cov khoom siv patch yog muab tso rau hauv qab txheej, qee zaum, nws yuav cuam tshuam rau ib sab yoj soldering. Hauv qhov no, cov txheej txheem vuam kim dua, xws li kev xaiv vuam, yog siv.
3.Qhov kev ncua deb ntawm cov khoom thiab cov phaj ntug
Yog tias nws yog tshuab vuam, qhov kev ncua deb ntawm cov khoom siv hluav taws xob thiab cov ntug ntawm lub rooj tsavxwm feem ntau yog 7 hli (cov tuam txhab vuam sib txawv muaj cov kev xav tau sib txawv), tab sis nws kuj tseem tuaj yeem muab ntxiv rau hauv cov txheej txheem ntawm PCB, kom cov khoom siv hluav taws xob tuaj yeem ua tau. muab tso rau ntawm PCB board ntug, tsuav yog nws yooj yim rau kev xaim.
Txawm li cas los xij, thaum ntug ntawm lub phaj yog welded, nws yuav ntsib cov kev taw qhia ntawm lub tshuab thiab ua rau cov khoom puas. Cov cuab yeej ncoo ntawm ntug ntawm lub phaj yuav raug tshem tawm hauv kev tsim khoom. Yog tias lub ncoo me me, qhov vuam zoo yuav raug cuam tshuam.
4.Qhov deb ntawm cov khoom siv siab / qis
Muaj ntau yam khoom siv hluav taws xob, cov duab sib txawv, thiab ntau yam ntawm cov kab hlau lead, yog li muaj qhov sib txawv ntawm kev sib dhos ntawm cov ntawv luam tawm. Kev teeb pom kev zoo tuaj yeem tsis tsuas yog ua rau lub tshuab ruaj khov, ua pov thawj poob siab, txo kev puas tsuaj, tab sis kuj tuaj yeem tau txais cov txiaj ntsig zoo thiab zoo nkauj hauv lub tshuab.
Cov khoom siv me me yuav tsum tau khaws cia ntawm qhov deb ntawm cov khoom siv siab. Cov cuab yeej nrug deb ntawm lub cuab yeej qhov siab piv yog me me, muaj qhov tsis sib xws ntawm thermal yoj, uas yuav ua rau muaj kev pheej hmoo ntawm kev vuam tsis zoo lossis kho tom qab vuam.
5.Ntaus rau ntaus ntawv sib nrug
Nyob rau hauv General SMT ua, nws yog ib qho tsim nyog yuav tsum tau coj mus rau hauv tus account qee qhov yuam kev hauv mounting ntawm lub tshuab, thiab coj mus rau hauv tus account yooj yim ntawm kev saib xyuas thiab pom kev. Ob qho khoom uas nyob ib sab yuav tsum tsis txhob nyob ze heev thiab ib qho kev nyab xeeb yuav tsum tau sab laug.
Qhov sib nrug ntawm flake Cheebtsam, SOT, SOIC thiab flake Cheebtsam yog 1.25mm. Qhov sib nrug ntawm flake Cheebtsam, SOT, SOIC thiab flake Cheebtsam yog 1.25mm. 2.5 hli ntawm PLCC thiab flake Cheebtsam, SOIC thiab QFP. 4mm ntawm PLCCS. Thaum tsim PLCC lub qhov (socket), yuav tsum tau saib xyuas kom tso cai rau qhov loj ntawm PLCC qhov (socket) PLCC nyob rau hauv qab ntawm lub qhov (socket).
6. Kab dav / kab nrug
Rau cov neeg tsim qauv, nyob rau hauv tus txheej txheem ntawm kev tsim, peb tuaj yeem tsis tsuas yog xav txog qhov tseeb thiab kev ua tiav ntawm cov qauv tsim, muaj kev txwv loj yog cov txheej txheem tsim khoom. Nws yog tsis yooj yim sua rau ib tug board Hoobkas los tsim ib tug tshiab ntau lawm kab rau yug ntawm ib tug zoo khoom.
Raws li ib txwm muaj, txoj kab dav ntawm txoj kab nqes mus rau 4/4mil, thiab lub qhov raug xaiv los ua 8mil (0.2mm). Yeej, ntau tshaj 80% ntawm PCB manufacturers tuaj yeem tsim, thiab cov nqi tsim khoom yog qhov qis tshaj. Qhov tsawg kawg nkaus txoj kab dav thiab kab nrug tuaj yeem tswj tau rau 3/3mil, thiab 6mil (0.15mm) tuaj yeem xaiv los ntawm lub qhov. Yeej, ntau tshaj li 70% PCB manufacturers tuaj yeem tsim tau, tab sis tus nqi yog me ntsis siab dua li thawj rooj plaub, tsis ntau dua.
7.Lub kaum sab xis / sab xis
Ntse lub tswv yim qub yog feem ntau txwv nyob rau hauv cov xaim, txoj kev sib tw kaum, thiab yuav luag los ua ib qho ntawm cov qauv los ntsuas cov hluav taws xob zoo. Vim tias qhov kev ncaj ncees ntawm lub teeb liab raug cuam tshuam, txoj hlua txoj cai yuav tsim cov kab mob parasitic ntxiv thiab inductance.
Nyob rau hauv cov txheej txheem ntawm PCB phaj-ua, PCB xov hlau sib tshuam ntawm lub kaum sab xis, uas yuav ua rau muaj teeb meem hu ua acid Angle. Nyob rau hauv PCB Circuit etching txuas, ntau dhau corrosion ntawm PCB Circuit Court yuav tshwm sim ntawm "acids hauv pcb Circuit Court qhov teeb meem so. Yog li ntawd, PCB engineers yuav tsum zam kom tsis txhob muaj cov ntse ntse lossis txawv txawv hauv cov xov hlau, thiab tuav lub kaum sab xis ntawm 45 degree ntawm lub kaum sab xis.
8.Copper strip / kob
Yog tias nws yog cov kob tooj liab loj txaus, nws yuav dhau los ua tus kav hlau txais xov, uas tuaj yeem ua rau lub suab nrov thiab lwm yam cuam tshuam hauv lub rooj tsavxwm (vim nws cov tooj liab tsis yog hauv av - nws yuav dhau los ua lub teeb liab).
Copper strips thiab Islands tuaj yog ntau txheej txheej ntawm cov dawb-floating tooj liab, uas tuaj yeem ua rau qee qhov teeb meem loj hauv cov kua qaub. Cov me me tooj liab tau paub tias tawg tawm ntawm PCB vaj huam sib luag thiab taug kev mus rau lwm qhov chaw etched ntawm lub vaj huam sib luag, ua rau luv luv.
9.Lub nplhaib ntawm qhov drilling qhov
Lub nplhaib lub qhov hais txog ib lub nplhaib ntawm tooj liab nyob ib ncig ntawm lub qhov laum. Vim muaj kev thev naus laus zis hauv kev tsim khoom, tom qab kev txav, thiab tooj liab plating ib puag ncig lub ncoo zoo ib yam, uas yuav ua rau lub qhov taub hau tawg.
Ib sab ntawm lub nplhaib lub nplhaib yuav tsum ntau dua 3.5mil, thiab lub nplhaib ntsaws lub nplhaib yuav tsum ntau dua 6mil. Lub nplhaib lub qhov me me dhau. Nyob rau hauv cov txheej txheem ntawm kev tsim khoom thiab kev tsim khoom, lub qhov drilling muaj qhov kam rau ua thiab kev ua kom zoo ntawm cov kab kuj muaj qhov kam rau ua. Qhov sib txawv ntawm qhov kam rau ua yuav ua rau lub nplhaib lub nplhaib tawg qhov qhib Circuit Court.
10.Lub kua muag poob ntawm cov xov hlau
Ntxiv cov kua muag rau PCB thaiv tuaj yeem ua rau kev sib txuas hauv Circuit Court ntawm PCB pawg thawj coj saib kom ruaj khov, muaj kev ntseeg siab, kom lub kaw lus yuav ruaj khov dua, yog li nws yuav tsum tau ntxiv kua muag rau lub rooj tsav xwm hauv Circuit Court.
Qhov sib ntxiv ntawm cov kua muag poob tuaj yeem zam qhov kev cuam tshuam ntawm qhov kev sib cuag ntawm cov xaim thiab cov ntaub qhwv los yog cov hlau thiab lub qhov pilot thaum lub rooj tsav xwm Circuit Court raug cuam tshuam los ntawm lub zog loj sab nraud. Thaum ntxiv cov kua muag poob rau vuam, nws tuaj yeem tiv thaiv lub ncoo, zam ntau qhov vuam kom ua rau lub ncoo poob, thiab tsis txhob sib sib zog nqus etching thiab tawg los ntawm lub qhov deflection thaum lub sij hawm tsim khoom.
