1 lus nug

Nrog rau qhov loj-scale nce nyob rau hauv kev tsim complexity thiab kev koom ua ke ntawm hluav taws xob systems, moos speeds thiab ntaus ntawv nce lub sij hawm tau txais sai thiab sai, thiab kev kub ceev PCB tsim tau dhau los ua ib feem tseem ceeb ntawm cov txheej txheem tsim. Hauv kev tsim hluav taws xob high-speed, qhov inductance thiab capacitance ntawm cov kab hluav taws xob Circuit Court ua rau cov hlau sib npaug rau cov kab sib kis. Kev teeb tsa tsis raug ntawm qhov kev txiav tawm tsis raug lossis kev xaim tsis raug ntawm cov teeb liab siab ceev tuaj yeem ua rau muaj teeb meem kev sib txuas lus, ua rau cov ntaub ntawv tsis raug los ntawm lub cev, kev ua haujlwm tsis zoo lossis tsis ua haujlwm txhua. Raws li cov qauv kev sib txuas lus, kom ua tiav, cov kab sib txuas yuav ua rau muaj kev cuam tshuam tsis zoo xws li teeb liab kev xav, crosstalk, electromagnetic cuam tshuam, kev siv hluav taws xob thiab cov suab nrov hauv av rau kev tsim hluav taws xob.

Txhawm rau tsim kom muaj kev kub ceev PCB Circuit Court board uas tuaj yeem ua haujlwm tau zoo, tus tsim yuav tsum tau ua kom tiav thiab ua tib zoo txiav txim siab los daws qee qhov teeb meem tsis txaus ntseeg uas yuav tshwm sim thaum lub sij hawm teeb tsa thiab kev teeb tsa, ua kom lub voj voog tsim khoom, thiab txhim kho kev lag luam kev sib tw.

Yuav ua li cas siv PROTEL tsim cov cuab yeej rau kev kub ceev PCB tsim

2 Layout tsim ntawm high zaus system

Hauv kev tsim PCB ntawm lub voj voog, qhov kev teeb tsa yog qhov txuas tseem ceeb. Qhov tshwm sim ntawm qhov kev teeb tsa yuav cuam tshuam ncaj qha rau cov kab hluav taws xob thiab kev ntseeg siab ntawm lub kaw lus, uas yog lub sijhawm siv ntau tshaj plaws thiab nyuaj rau tag nrho cov ntawv luam tawm Circuit Board tsim. Lub complex ib puag ncig ntawm high-frequency PCB ua rau lub layout tsim ntawm high-frequency system nyuaj rau siv cov kev kawm theoretical paub. Nws xav kom tus neeg uas lays tawm yuav tsum muaj kev nplua nuj nyob rau hauv high-ceev PCB manufacturing, thiaj li tsis txhob detours nyob rau hauv tus txheej txheem tsim. Txhim kho qhov kev ntseeg siab thiab kev ua tau zoo ntawm kev ua haujlwm hauv Circuit Court. Nyob rau hauv tus txheej txheem ntawm layout, kev xav txog yuav tsum tau muab rau cov neeg kho tshuab qauv, tshav kub dissipation, electromagnetic cuam tshuam, yooj yim rau yav tom ntej thaiv, thiab zoo nkauj.

Ua ntej ntawm tag nrho cov, ua ntej layout, tag nrho cov Circuit Court muab faib ua functions. Lub high-frequency Circuit Court yog sib cais los ntawm qhov tsawg-frequency Circuit Court, thiab cov analog circuits thiab cov digital circuits yog sib cais. Txhua qhov chaw ua haujlwm tau muab tso rau ze li sai tau rau qhov chaw ntawm lub nti. Tsis txhob ncua kev sib kis los ntawm cov xov hlau ntev ntev, thiab txhim kho cov nyhuv decoupling ntawm capacitors. Tsis tas li ntawd, xyuam xim rau cov txheeb ze txoj haujlwm thiab cov lus qhia ntawm cov pins thiab cov khoom siv hluav taws xob thiab lwm cov raj kom txo tau lawv cov kev cuam tshuam. Tag nrho cov khoom siv ntau zaus yuav tsum nyob deb ntawm lub chassis thiab lwm cov hlau phaj kom txo tau cov kab mob sib kis.

Qhov thib ob, kev saib xyuas yuav tsum tau them rau cov thermal thiab electromagnetic cuam tshuam ntawm cov khoom thaum lub sij hawm layout. Cov teebmeem no yog qhov tshwj xeeb tshaj yog rau cov tshuab siv ntau zaus, thiab kev ntsuas kom nyob deb lossis cais tawm, yuav tsum tau ua kom sov thiab tiv thaiv. Lub hwj chim rectifier raj thiab lub raj hloov kho yuav tsum tau nruab nrog lub tshuab hluav taws xob thiab khaws cia deb ntawm lub transformer. Thaum tshav kub kub-resistant Cheebtsam xws li electrolytic capacitors yuav tsum tau khaws cia kom deb ntawm cov cua sov Cheebtsam, txwv tsis pub cov electrolyte yuav qhuav, ua rau muaj zog tiv thaiv thiab tsis ua hauj lwm, uas yuav cuam tshuam rau stability ntawm lub Circuit Court. Qhov chaw txaus yuav tsum tau muab tso rau hauv qhov kev teeb tsa los npaj cov qauv kev tiv thaiv thiab tiv thaiv kev taw qhia ntawm ntau yam kab mob parasitic couplings. Txhawm rau tiv thaiv electromagnetic coupling ntawm cov coils ntawm lub rooj tsav xwm luam tawm, ob lub coils yuav tsum tau muab tso rau ntawm lub kaum sab xis kom txo tau qhov sib txuas coefficient. Txoj kev ntawm ntsug phaj cais kuj siv tau. Nws yog qhov zoo tshaj plaws los siv cov hlau lead ntawm cov khoom siv los ua cov khoom siv hluav taws xob. Qhov luv luv ntawm cov hlau lead, qhov zoo dua. Tsis txhob siv cov connectors thiab soldering tabs vim hais tias muaj kev faib capacitance thiab faib inductance ntawm cov nyob ib sab soldering tabs. Tsis txhob tso cov suab nrov nrov nyob ib puag ncig ntawm cov siv lead ua oscillator, RIN, analog voltage, thiab siv cov teeb liab hluav taws xob.

Thaum kawg, thaum ua kom ntseeg tau qhov zoo thiab kev ntseeg siab, thaum coj mus rau hauv tus account tag nrho cov kev zoo nkauj, tsim nyog Circuit Court board npaj yuav tsum tau ua. Lub Cheebtsam yuav tsum yog parallel los yog perpendicular mus rau lub board nto, thiab parallel los yog perpendicular mus rau lub ntsiab board ntug. Kev faib tawm ntawm cov khoom ntawm lub rooj tsavxwm saum npoo yuav tsum yog raws li qhov ua tau thiab qhov ceev yuav tsum zoo ib yam. Nyob rau hauv txoj kev no, nws tsis yog tsuas yog zoo nkauj, tab sis kuj yooj yim rau assemble thiab weld, thiab nws yog ib qho yooj yim rau loj tsim.

3 Kev xaim ntawm qhov system siab

Nyob rau hauv high-frequency circuits, qhov kev faib tsis ua hauj lwm, capacitance, inductance thiab kev sib nrig sib inductance ntawm cov xov hlau txuas tsis tuaj yeem raug ignored. Los ntawm qhov kev xav ntawm kev cuam tshuam los ntawm kev cuam tshuam, kev xaim tsim nyog yog los sim txo cov kab tsis kam, faib cov peev txheej, thiab tsis muaj zog inductance hauv Circuit Court. , Lub resulting stray magnetic teb yog txo mus rau ib tug tsawg kawg nkaus, thiaj li hais tias cov distribution capacitance, leakage magnetic flux, electromagnetic inductance thiab lwm yam cuam tshuam los ntawm lub suab yog suppressed.

Daim ntawv thov ntawm PROTEL tsim cov cuab yeej hauv Suav teb tau ntau heev. Txawm li cas los xij, ntau tus neeg tsim qauv tsuas yog tsom mus rau “tus nqi dav dav”, thiab kev txhim kho los ntawm PROTEL cov cuab yeej tsim los hloov kho cov kev hloov ntawm cov yam ntxwv ntawm cov cuab yeej siv tsis tau siv rau hauv kev tsim, uas tsis tsuas yog ua rau cov khoom siv pov tseg ntawm cov cuab yeej tsim khoom siv ntau dua. hnyav, uas ua rau nws nyuaj rau kev ua tau zoo ntawm ntau yam tshiab tuaj yeem coj los ua si.

Cov hauv qab no qhia txog qee qhov haujlwm tshwj xeeb uas PROTEL99 SE cov cuab yeej tuaj yeem muab tau.

(1) Cov hlau lead ntawm cov pins ntawm cov khoom siv hluav taws xob ntau zaus yuav tsum tau khoov kom tsawg li sai tau. Nws yog qhov zoo tshaj los siv ib txoj kab ncaj nraim. Thaum yuav tsum tau khoov, 45 ° khoov lossis arcs tuaj yeem siv tau, uas tuaj yeem txo qis sab nraud emission ntawm high-frequency signals thiab sib cuam tshuam. Lub coupling ntawm. Thaum siv PROTEL rau routing, koj tuaj yeem xaiv 45-Degrees lossis Rounded hauv “Routing Corners” hauv “txoj cai” ntawv qhia zaub mov ntawm “Tsim” ntawv qhia. Koj tseem tuaj yeem siv qhov hloov pauv + qhov chaw yuam sij kom hloov pauv sai ntawm cov kab.

(2) Cov hlau lead luv luv ntawm cov pins ntawm cov khoom siv hluav taws xob ntau zaus, qhov zoo dua.

PROTEL 99 Txoj hauv kev ua tau zoo tshaj plaws kom tau raws li qhov luv luv tshaj plaws yog ua kom lub sij hawm xaim rau ib tus neeg tseem ceeb hauv kev sib txuas ceev ceev ua ntej xaim tsis siv neeg. “RoutTing Topology” hauv “cov cai” hauv “Tsim” ntawv qhia zaub mov

Xaiv luv tshaj plaws.

(3) Kev sib hloov ntawm cov hlau lead txheej ntawm cov pins ntawm cov khoom siv hluav taws xob ntau zaus tsawg li tsawg tau. Ntawd yog, tsawg dua vias siv hauv cov txheej txheem kev sib txuas, qhov zoo dua.

Ib qho ntawm tuaj yeem nqa txog 0.5pF ntawm kev faib tawm, thiab txo tus naj npawb ntawm vias tuaj yeem nce qhov nrawm.

(4) Rau kev xaim hluav taws xob ntau zaus, ua tib zoo saib rau “kev cuam tshuam hla” qhia los ntawm kev sib txuas ntawm cov kab teeb liab, uas yog, crosstalk. Yog tias tsis muaj kev faib tawm mus ib txhis, thaj tsam loj ntawm “hauv av” tuaj yeem teem caij rau sab nraud ntawm cov kab hluav taws xob sib txuas

Txhawm rau txo kev cuam tshuam zoo heev. Kev xaim hluav taws xob sib txuas hauv tib txheej yog yuav luag tsis tuaj yeem zam, tab sis nyob rau hauv ob txheej uas nyob ib sab, cov kev taw qhia ntawm cov xaim yuav tsum yog perpendicular rau ib leeg. Qhov no tsis yog qhov nyuaj ua hauv PROTEL tab sis nws yooj yim rau kev saib xyuas. Hauv “RouTIngLayers” hauv “Tsim” ntawv qhia zaub mov “txoj cai”, xaiv Kab rov tav rau Toplayer thiab VerTIcal rau BottomLayer. Tsis tas li ntawd, “Polygonplane” yog muab rau hauv “qhov chaw”

Kev ua haujlwm ntawm polygonal grid tooj liab ntawv ci nto, yog tias koj tso lub polygon ua ib qho chaw ntawm tag nrho cov ntawv luam tawm hauv Circuit Court, thiab txuas cov tooj liab no rau GND ntawm Circuit Court, nws tuaj yeem txhim kho qhov muaj peev xwm tiv thaiv kev cuam tshuam, nws kuj muaj. Cov txiaj ntsig zoo dua rau cov cua sov dissipation thiab luam ntawv board lub zog.

(5) Siv cov kev ntsuas hauv av rau cov kab teeb liab tshwj xeeb lossis cov chaw hauv zos. “Txoj kev xaiv cov khoom” yog muab rau hauv “Cov Cuab Yeej”, thiab cov haujlwm no tuaj yeem siv los ua “qhib hauv av” ntawm cov kab teeb liab tseem ceeb (xws li oscillation circuit LT thiab X1).

(6) Feem ntau, cov kab hluav taws xob thiab cov kab hauv av ntawm lub voj voog yog dav dua li cov kab teeb liab. Koj tuaj yeem siv “Chav” hauv “Tsim” ntawv qhia zaub mov los faib cov network, uas tau muab faib ua lub zog hluav taws xob thiab cov teeb liab network. Nws yog qhov yooj yim los teeb tsa cov kev cai ntawm kev xaim. Hloov cov kab dav ntawm cov kab hluav taws xob thiab cov teeb liab kab.

(7) Ntau hom kev xaim tsis tuaj yeem tsim lub voj, thiab cov xaim hauv av tsis tuaj yeem tsim lub voj voog tam sim no. Yog tias lub voj voj voog raug tsim tawm, nws yuav ua rau muaj kev cuam tshuam ntau hauv qhov system. Ib txoj kev daisy saw hlau yuav siv tau rau qhov no, uas tuaj yeem zam qhov tsim ntawm cov voj voog, ceg lossis cov pob zeb thaum lub sij hawm xaim, tab sis nws tseem yuav ua rau cov teeb meem tsis yooj yim txuas.

(8) Raws li cov ntaub ntawv thiab tsim ntawm ntau yam chips, kwv yees qhov tam sim no dhau los ntawm lub zog hluav taws xob hluav taws xob thiab txiav txim siab qhov dav hlau yuav tsum tau ua. Raws li cov qauv qhia pom: W (kab dav) ≥ L (mm / A) × I (A).

Raws li qhov tam sim no, sim ua kom qhov dav ntawm txoj kab hluav taws xob thiab txo lub voj tsis kam. Nyob rau tib lub sijhawm, ua kom cov kev taw qhia ntawm cov kab hluav taws xob thiab cov kab hauv av sib haum nrog cov kev taw qhia ntawm cov ntaub ntawv xa mus, uas yuav pab txhim kho lub peev xwm los tiv thaiv lub suab nrov. Thaum tsim nyog, cov cuab yeej siv hluav taws xob ntau zaus ua los ntawm tooj liab hlau qhov txhab ferrite tuaj yeem muab ntxiv rau cov kab hluav taws xob thiab hauv av kab los thaiv cov suab nrov nrov.

(9) Qhov dav dav ntawm tib lub network yuav tsum khaws cia tib yam. Kev hloov pauv hauv kab dav yuav ua rau cov kab tsis sib xws impedance. Thaum qhov kev sib kis ceev yog siab, kev xav yuav tshwm sim, uas yuav tsum tau zam kom ntau li ntau tau hauv kev tsim. Nyob rau tib lub sijhawm, nce kab dav ntawm cov kab sib txuas. Thaum txoj kab nruab nrab tsis tshaj 3 npaug ntawm kab dav, 70% ntawm cov hluav taws xob tuaj yeem tswj tau yam tsis muaj kev cuam tshuam, uas yog hu ua 3W txoj cai. Nyob rau hauv txoj kev no, kev cuam tshuam ntawm kev faib capacitance thiab faib inductance tshwm sim los ntawm cov kab sib txuas tuaj yeem kov yeej.

4 Tsim cov hlua hluav taws xob thiab hauv av xaim

Yuav kom daws tau qhov voltage poob los ntawm lub hwj chim mov suab nrov thiab kab impedance qhia los ntawm lub high-frequency Circuit Court, kev ntseeg siab ntawm lub hwj chim mov system nyob rau hauv lub high-frequency Circuit Court yuav tsum tau tag nrho xav txog. Feem ntau muaj ob txoj kev daws teeb meem: ib qho yog siv hluav taws xob tsheb npav tshuab rau kev xaim; lwm qhov yog siv cov txheej txheem hluav taws xob sib cais. Hauv kev sib piv, cov txheej txheem tsim khoom tom kawg yog qhov nyuaj thiab tus nqi kim dua. Yog li ntawd, lub network-hom fais fab tsheb npav tshuab tuaj yeem siv rau kev xaim, kom txhua yam khoom sib txawv ntawm lub voj voog sib txawv, thiab tam sim no ntawm txhua lub tsheb npav hauv lub network nyiam sib npaug, txo qhov voltage poob los ntawm kab impedance.

Lub zog xa hluav taws xob ntau zaus yog qhov loj, koj tuaj yeem siv thaj tsam loj ntawm tooj liab, thiab nrhiav tau lub dav hlau uas tsis tshua muaj nyob ze rau ntau qhov av. Vim tias qhov inductance ntawm cov hlau lead hauv av yog proportional rau qhov zaus thiab qhov ntev, qhov sib txawv hauv av impedance yuav nce ntxiv thaum lub sijhawm ua haujlwm siab, uas yuav ua rau muaj kev cuam tshuam ntawm electromagnetic cuam tshuam los ntawm qhov sib txawv hauv av impedance, yog li qhov ntev ntawm cov hlau hauv av. yuav tsum ua kom luv li sai tau. Sim txo qhov ntev ntawm cov teeb liab kab thiab ua rau thaj tsam ntawm lub voj voog hauv av.

Teem ib los yog ob peb lub high-frequency decoupling capacitors ntawm lub hwj chim thiab hauv av ntawm lub nti kom muab ib tug nyob ze high-frequency channel rau lub sij hawm tam sim no ntawm cov nti integrated, kom cov tam sim no tsis dhau los ntawm lub hwj chim mov kab nrog ib tug loj voj voog. cheeb tsam, yog li no zoo heev txo Lub suab nrov radiated mus rau sab nraud. Xaiv cov monolithic ceramic capacitors nrog cov cim zoo siab zoo li decoupling capacitors. Siv lub peev xwm loj tantalum capacitors lossis polyester capacitors es tsis txhob electrolytic capacitors ua lub zog cia capacitors rau kev them nqi hluav taws xob. Vim tias qhov sib faib inductance ntawm electrolytic capacitor loj, nws tsis siv tau rau qhov siab. Thaum siv electrolytic capacitor, siv lawv ua khub nrog decoupling capacitors nrog cov yam ntxwv zoo siab.

5 Lwm cov txheej txheem tsim hluav taws xob high-speed

impedance txuam yog hais txog lub xeev ua hauj lwm nyob rau hauv uas lub load impedance thiab lub internal impedance ntawm excitation qhov chaw yog yoog rau ib leeg kom tau txais lub siab tshaj plaws lub zog tso zis. Rau kev kub ceev PCB thaiv, txhawm rau tiv thaiv kev cuam tshuam cov teeb liab, qhov impedance ntawm Circuit Court yuav tsum yog 50 Ω. Nov yog daim duab kwv yees. Feem ntau, nws tau teev tseg tias lub hauv paus ntawm coaxial cable yog 50 Ω, zaus band yog 75 Ω, thiab cov xov hlau twisted yog 100 Ω. Nws tsuas yog tus lej xwb, rau qhov yooj yim ntawm kev sib piv. Raws li kev txheeb xyuas qhov tshwj xeeb hauv Circuit Court, qhov kev sib txuas AC txiav tawm tau txais, thiab cov resistor thiab capacitor network yog siv los ua qhov kev txiav tawm impedance. Qhov kev txiav tawm tsis kam R yuav tsum tsawg dua lossis sib npaug ntawm cov kab xaim impedance Z0, thiab qhov capacitance C yuav tsum siab dua 100 pF. Nws raug nquahu kom siv 0.1UF multilayer ceramic capacitors. Lub capacitor muaj lub luag haujlwm ntawm kev thaiv qhov tsawg zaus thiab dhau qhov zaus, yog li qhov tsis kam R tsis yog DC load ntawm qhov tsav tsheb, yog li txoj kev txiav tawm no tsis muaj DC lub zog siv.

Crosstalk yog hais txog qhov tsis xav tau lub suab nrov nrov cuam tshuam los ntawm electromagnetic coupling rau cov kab sib txuas uas nyob ib sab thaum lub teeb liab nthuav tawm ntawm kab sib kis. Coupling muab faib ua capacitive coupling thiab inductive coupling. Kev sib tham ntau dhau tuaj yeem ua rau muaj kev cuam tshuam tsis tseeb ntawm Circuit Court thiab ua rau lub cev tsis ua haujlwm ib txwm. Raws li qee tus yam ntxwv ntawm crosstalk, ntau txoj hauv kev los txo cov crosstalk tuaj yeem sau tseg:

(1) Ua kom txoj kab sib nrug, txo qhov sib npaug ntawm qhov ntev, thiab siv txoj kev khiav mus rau kev xaim yog tias tsim nyog.

(2) Thaum cov kab teeb liab ceev tau ua tau raws li cov xwm txheej, ntxiv qhov kev txiav txim siab tuaj yeem txo lossis tshem tawm cov kev xav, yog li txo cov lus sib tham.

(3) Rau microstrip kis kab thiab kab sib kis kab, txwv txoj kab qhov siab mus rau hauv thaj tsam saum toj no lub dav hlau hauv av tuaj yeem txo qhov kev sib tw.

(4) Thaum qhov chaw xaim tso cai, ntxig rau hauv av hauv nruab nrab ntawm ob lub xov hlau nrog kev sib tham loj dua, uas tuaj yeem ua lub luag haujlwm hauv kev sib cais thiab txo kev sib tham.

Vim tsis muaj kev soj ntsuam kev kub ceev thiab simulation kev taw qhia hauv cov qauv PCB ib txwm muaj, lub teeb liab tsis tuaj yeem lav tau zoo, thiab feem ntau ntawm cov teeb meem tsis tuaj yeem tshawb pom kom txog thaum lub phaj ua tiav. Qhov no zoo heev txo tus tsim efficiency thiab nce tus nqi, uas yog pom tseeb tsis zoo nyob rau hauv kev sib tw ua lag luam hnyav. Yog li ntawd, rau kev tsim PCB high-ceev, cov neeg hauv kev lag luam tau tawm tswv yim tshiab tsim, uas tau dhau los ua “sab saum toj-down” qauv tsim. Tom qab ntau yam kev tshuaj ntsuam xyuas thiab kev ua kom zoo, feem ntau ntawm cov teeb meem tshwm sim tau raug zam thiab kev txuag nyiaj ntau. Lub sij hawm los xyuas kom meej tias cov phiaj xwm phiaj xwm tau ua tiav, cov ntawv luam tawm zoo tshaj plaws raug tsim, thiab zam tsis dhau qhov kev xeem tsis raug nqi.

Kev siv cov kab sib txawv los xa cov teeb liab digital yog qhov kev ntsuas zoo los tswj cov xwm txheej uas rhuav tshem cov teeb liab kev ncaj ncees hauv high-speed digital circuits. Cov kab sib txawv ntawm lub rooj tsav xwm luam tawm yog sib npaug rau qhov sib txawv microwave sib txuas sib txuas ua ke ua haujlwm hauv quasi-TEM hom. Ntawm lawv, cov kab sib txawv nyob rau sab saum toj lossis hauv qab ntawm PCB yog sib npaug rau cov kab sib txuas microstrip thiab nyob rau hauv txheej txheej txheej ntawm multilayer PCB Cov kab sib txawv yog sib npaug rau cov kab sib txuas dav dav. Cov teeb liab digital tau xa mus rau ntawm kab sib txawv hauv hom khib-hom kis tau tus mob, uas yog, theem sib txawv ntawm qhov zoo thiab qhov tsis zoo yog 180 °, thiab lub suab nrov yog ua ke ntawm ob kab sib txawv hauv hom sib txawv. Qhov voltage lossis tam sim no ntawm Circuit Court raug rho tawm, kom lub teeb liab tau txais los tshem tawm cov suab nrov nrov. Qhov tsawg-voltage amplitude los yog tam sim no tsav tso zis ntawm qhov sib txawv kab khub ua tiav cov kev xav tau ntawm kev sib koom ua haujlwm siab thiab kev siv hluav taws xob tsawg.

6 cov lus xaus

Nrog rau kev txhim kho txuas ntxiv ntawm kev siv tshuab hluav taws xob, nws yog ib qho tseem ceeb kom nkag siab txog qhov kev xav ntawm lub teeb liab kev ncaj ncees los qhia thiab txheeb xyuas qhov tsim ntawm high-speed PCBs. Qee qhov kev paub dhau los hauv tsab xov xwm no tuaj yeem pab cov neeg tsim hluav taws xob siab ceev PCB ua kom luv luv ntawm txoj kev loj hlob, zam kev tsis tsim nyog, thiab txuag cov neeg ua haujlwm thiab cov khoom siv. Cov neeg tsim qauv yuav tsum txuas ntxiv mus tshawb fawb thiab tshawb nrhiav hauv kev ua haujlwm tiag tiag, txuas ntxiv kev paub dhau los, thiab sib txuas cov thev naus laus zis tshiab los tsim kev kub ceev PCB Circuit Board nrog kev ua haujlwm zoo.