Hauv kev tsim, layout yog ib feem tseem ceeb.Qhov tshwm sim ntawm qhov kev teeb tsa yuav cuam tshuam ncaj qha rau cov txiaj ntsig ntawm kev xaim, yog li koj tuaj yeem xav txog qhov no, qhov tsim nyog tsim nyog yog thawj kauj ruam hauv kev ua tiav ntawm PCB tsim.
Tshwj xeeb, pre-layout yog cov txheej txheem ntawm kev xav txog tag nrho lub rooj tsavxwm, teeb liab ntws, cua sov dissipation, qauv thiab lwm yam architecture.Yog tias qhov kev teeb tsa ua ntej yog qhov ua tsis tiav, tom qab kev siv zog ntau dua kuj yog qhov tsis muaj txiaj ntsig.
1. Xav txog tag nrho
Kev vam meej ntawm cov khoom lag luam lossis tsis yog, ib qho yog tsom mus rau sab hauv zoo, qhov thib ob yog coj mus rau hauv tus account tag nrho kev zoo nkauj, ob qho tib si zoo tshaj plaws los xav txog cov khoom lag luam zoo.
Ntawm lub rooj tsavxwm PCB, qhov kev teeb tsa ntawm cov khoom yuav tsum sib npaug, sib cais thiab ua kom zoo, tsis yog qhov hnyav lossis lub taub hau hnyav.
PCB puas yuav deformed?
Puas yog txheej txheem ntug tshwj tseg?
Puas yog MARK cov ntsiab lus tshwj tseg?
Puas tsim nyog muab lub rooj tsavxwm ua ke?
Muaj pes tsawg txheej ntawm lub rooj tsavxwm, tuaj yeem ua kom muaj kev tswj xyuas impedance, teeb liab thaiv, teeb liab kev ncaj ncees, kev lag luam, kev ua tiav?
2. Tshem tawm qhov yuam kev qis
Puas yog lub rooj tsavxwm luam ntawv loj npaum li cas nrog rau kev ua daim duab loj?Nws puas tuaj yeem ua tau raws li cov txheej txheem tsim khoom PCB?Puas muaj lub cim qhia?
Cheebtsam nyob rau hauv ob-dimensional, peb-dimensional qhov chaw tsis muaj teeb meem?
Puas yog qhov layout ntawm cov khoom nyob rau hauv kev txiav txim thiab zoo zoo?Puas yog tag nrho daim ntaub tiav lawm?
Cov khoom siv uas yuav tsum tau hloov ntau zaus tuaj yeem hloov tau yooj yim?Puas yog nws yooj yim rau ntxig lub ntxig rau hauv cov khoom siv?
Puas muaj qhov kev ncua deb ntawm cov thermal thiab cov khoom cua sov?
Puas yog nws yooj yim los kho cov khoom kho tau?
Puas yog lub dab dej kub nruab rau qhov uas yuav tsum tau ua kom sov dissipation?Puas yog huab cua ntws zoo?
Puas yog lub teeb liab ntws du thiab luv tshaj kev sib txuas?
Puas yog plugs, qhov (sockets, thiab lwm yam) contradictory rau cov neeg kho tshuab tsim?
Puas yog qhov teeb meem cuam tshuam ntawm txoj kab raug txiav txim siab?
3. Bypass lossis decoupling capacitor
Hauv kev xaim, cov khoom siv analog thiab cov khoom siv digital xav tau cov hom capacitors, yuav tsum nyob ze rau lawv lub hwj chim pins txuas nrog lub bypass capacitor, tus nqi capacitance feem ntau yog 0.1.μF. pins luv li sai tau los txo qhov inductive tsis kam ntawm kev sib tw, thiab ze li sai tau rau lub cuab yeej.
Ntxiv bypass lossis decoupling capacitors rau lub rooj tsavxwm, thiab qhov chaw ntawm cov capacitors ntawm lub rooj tsavxwm, yog cov kev paub yooj yim rau ob qho tib si digital thiab analog designs, tab sis lawv cov dej num txawv.Bypass capacitors feem ntau siv nyob rau hauv cov qauv kev sib txuas sib txuas los hla cov teeb liab ntau zaus los ntawm lub zog hluav taws xob uas yuav txwv tsis pub nkag mus rau cov khoom siv hluav taws xob analog los ntawm lub hwj huam mov pins.Feem ntau, qhov zaus ntawm cov teeb liab siab zaus tshaj qhov analog ntaus ntawv lub peev xwm los txwv lawv.Yog hais tias bypass capacitors tsis siv nyob rau hauv analog circuits, suab nrov thiab, nyob rau hauv cov ntaub ntawv hnyav dua, kev co tuaj yeem qhia tau rau hauv txoj kev teeb liab.Rau cov khoom siv digital xws li controllers thiab processors, decoupling capacitors kuj xav tau, tab sis vim txawv.Ib txoj haujlwm ntawm cov capacitors no yog ua raws li "cov khoom me me" them nyiaj hauv tuam txhab, vim hais tias nyob rau hauv digital circuits, ua lub rooj vag xeev hloov (xws li, hloov pauv) feem ntau yuav tsum muaj ntau qhov tam sim no, thiab thaum hloov pauv hloov pauv tau tsim tawm ntawm cov nti thiab ntws. los ntawm lub rooj tsavxwm, nws yog qhov zoo kom muaj qhov "sparre" ntxiv."tus nqi yog qhov zoo.Yog tias tsis muaj nqi txaus los ua qhov kev hloov pauv, nws tuaj yeem ua rau muaj kev hloov pauv loj hauv cov khoom siv hluav taws xob.Kev hloov pauv loj dhau tuaj yeem ua rau theem teeb liab digital nkag mus rau hauv lub xeev tsis meej thiab yuav ua rau lub xeev lub tshuab hauv cov cuab yeej digital ua haujlwm tsis raug.Qhov hloov pauv tam sim no ntws los ntawm kev sib dhos ntawm lub rooj tsavxwm yuav ua rau lub zog hloov pauv, vim yog cov kab mob parasitic inductance ntawm lub rooj tsavxwm sib dhos, qhov kev hloov hluav taws xob tuaj yeem suav nrog cov qauv hauv qab no: V = Ldl / dt qhov twg V = hloov voltage L = board alignment inductance dI = hloov tam sim no ntws los ntawm kev sib tw dt = lub sij hawm ntawm kev hloov tam sim no Yog li ntawd, rau ntau yam, lub hwj chim mov ntawm lub hwj chim mov los yog active li ntawm lub hwj chim pins thov Bypass (los yog decoupling) capacitors yog zoo heev xyaum. .
Cov khoom siv hluav taws xob input, yog tias qhov tam sim no loj heev, nws raug nquahu kom txo qhov ntev thiab thaj tsam ntawm kev sib dhos, tsis txhob khiav thoob plaws hauv lub tshav pob.
Lub suab hloov ntawm lub tswv yim txuas mus rau lub dav hlau ntawm lub zog tso zis.Kev hloov suab nrov ntawm MOS raj ntawm cov khoom siv hluav taws xob tso tawm cuam tshuam rau cov khoom siv hluav taws xob nkag ntawm theem pem hauv ntej.
Yog hais tias muaj ntau lub siab DCDC tam sim no nyob rau ntawm lub rooj tsavxwm, muaj ntau zaus sib txawv, tam sim no thiab high voltage dhia cuam tshuam.
Yog li peb yuav tsum tau txo qhov cheeb tsam ntawm lub input fais fab mov kom ua tau raws li qhov dhau-tam sim no ntawm nws.Yog li ntawd, thaum lub hwj huam mov layout, xav txog tsis txhob input fais fab mov puv board khiav.
4. Cov kab hluav taws xob thiab hauv av
Cov kab hluav taws xob thiab cov kab hauv av yog qhov zoo sib xws, tuaj yeem txo qhov cuam tshuam ntawm electromagnetic cuam tshuam (EMl).Yog tias cov kab hluav taws xob thiab hauv av tsis haum zoo, lub voj voog yuav raug tsim, thiab yuav ua rau muaj suab nrov.Ib qho piv txwv ntawm lub zog tsis raug cai thiab hauv av PCB tsim yog qhia hauv daim duab.Nyob rau hauv lub rooj tsavxwm no, siv cov kev sib txawv ntawm cov ntaub ntawv fais fab thiab hauv av, vim qhov tsis zoo no, lub rooj tsavxwm cov khoom siv hluav taws xob thiab cov kab los ntawm electromagnetic cuam tshuam (EMI) yuav muaj ntau dua.
5. Digital-analog sib cais
Hauv txhua qhov PCB tsim, lub suab nrov ntawm Circuit Court thiab qhov "tsim" (tsis muaj suab nrov) yuav tsum tau sib cais.Feem ntau, lub digital Circuit Court tuaj yeem zam lub suab nrov cuam tshuam, thiab tsis hnov mob rau lub suab nrov (vim hais tias lub digital Circuit Court muaj lub suab nrov nrov);Ntawm qhov tsis sib xws, analog Circuit Court voltage suab kam rau siab yog tsawg dua.Ntawm ob, analog circuits yog qhov nkag siab tshaj plaws rau kev hloov suab nrov.Hauv kev sib xyaw ua ke-sib nqus tshuab, ob hom circuits yuav tsum tau sib cais.
Lub hauv paus ntawm circuit board thaiv siv rau ob qho tib si analog thiab digital circuits.Ib txoj cai tseem ceeb ntawm tus ntiv tes xoo yog siv lub dav hlau hauv av tsis cuam tshuam.Txoj cai yooj yim no txo cov dI / dt (tam sim no piv rau lub sijhawm) cov txiaj ntsig hauv digital circuits vim tias cov nyhuv dI / dt ua rau hauv av muaj peev xwm thiab tso cai rau lub suab nrov nkag mus rau hauv analog circuits.Cov txheej txheem xaim rau digital thiab analog circuits yog qhov pib zoo ib yam, tsuas yog rau ib yam.Lwm yam uas yuav tsum nco ntsoov rau analog circuits yog khaws cov kab teeb liab digital thiab cov voj voog hauv av kom deb li deb ntawm analog circuit li sai tau.Qhov no tuaj yeem ua tiav los ntawm kev txuas lub dav hlau analog hauv av cais mus rau qhov system hauv av kev sib txuas, lossis los ntawm kev tso cov analog circuitry ntawm qhov kawg ntawm lub rooj tsavxwm, ntawm qhov kawg ntawm kab.Qhov no yog ua kom muaj kev cuam tshuam sab nraud rau txoj kev teeb liab mus rau qhov tsawg kawg nkaus.Qhov no tsis yog qhov tsim nyog rau digital circuits, uas tuaj yeem zam lub suab nrov ntawm lub dav hlau hauv av yam tsis muaj teeb meem.
6. Kev xav txog cua sov
Nyob rau hauv cov txheej txheem layout, yuav tsum tau xav txog thaum tshav kub dissipation cua ducts, tshav kub dissipation tuag xaus.
Thaum tshav kub kub-sensitive pab kiag li lawm yuav tsum tsis txhob muab tso rau tom qab lub tshav kub qhov cua.Muab qhov tseem ceeb rau qhov chaw teeb tsa ntawm cov tsev neeg uas muaj cua sov nyuaj xws li DDR.Tsis txhob rov kho dua vim thermal simulation tsis dhau.
Post lub sij hawm: Aug-30-2022