Niaj hnub no, kev sib cog lus ntawm cov khoom siv hluav taws xob ntau zuj zus yuav tsum tau tsim peb-dimensional ntawm multilayer printed circuit boards. Txawm li cas los xij, txheej txheej txheej tsim teeb meem tshiab ntsig txog qhov kev xav tsim no. Ib qho ntawm cov teeb meem yog kom tau txais cov txheej txheem zoo tshaj plaws rau qhov project.
Raws li ntau thiab ntau txoj kev luam tawm circuits tsim los ntawm ntau cov khaubncaws sab nraud povtseg, stacking ntawm PCBs tau dhau los ua qhov tseem ceeb.
Ib tug zoo PCB pawg tsim yog qhov tseem ceeb los txo cov hluav taws xob ntawm PCB loops thiab lwm yam circuits. Ntawm qhov tsis sib xws, kev sib txuam tsis zoo yuav ua rau muaj hluav taws xob ntau ntxiv, uas ua rau muaj kev phom sij los ntawm qhov pom kev nyab xeeb.
PCB stackup yog dab tsi?
Ua ntej qhov kawg layout tsim tiav, PCB stackup txheej cov insulator thiab tooj liab ntawm PCB. Tsim kom muaj txiaj ntsig stacking yog txheej txheem nyuaj. PCB txuas lub zog thiab cov teeb liab ntawm cov khoom siv lub cev, thiab cov txheej txheem ntawm cov khoom siv hluav taws xob ncaj qha cuam tshuam rau nws txoj haujlwm.
Vim li cas peb thiaj li yuav tsum tau laminate PCB?
Kev txhim kho ntawm PCB stackup yog qhov tseem ceeb rau kev tsim cov khoom siv hluav taws xob zoo. PCB stackup muaj ntau yam txiaj ntsig, vim tias cov txheej txheem multilayer tuaj yeem txhim kho kev faib hluav taws xob, tiv thaiv hluav taws xob cuam tshuam, txwv kev cuam tshuam hla, thiab txhawb kev xa xov hluav taws xob ceev.
Txawm hais tias lub hom phiaj tseem ceeb ntawm stacking yog tso ntau lub tshuab hluav taws xob ntawm ib lub rooj tsavxwm los ntawm ntau txheej txheej, cov txheej txheem stacked ntawm PCBs kuj muab lwm yam tseem ceeb zoo. Cov kev ntsuas no suav nrog txo qis qhov tsis zoo ntawm cov rooj sib tham hauv Circuit Court rau cov suab nrov sab nraud thiab txo cov teeb meem kev sib tham thiab impedance hauv cov tshuab ceev.
Ib qho zoo PCB stackup kuj tseem tuaj yeem pab kom txo qis cov nqi tsim khoom kawg. Los ntawm kev ua kom zoo tshaj plaws thiab txhim kho cov khoom siv hluav taws xob sib raug zoo ntawm tag nrho cov phiaj xwm, PCB stacking tuaj yeem txuag sijhawm thiab nyiaj txiag zoo.
Kev ceev faj thiab cov cai rau PCB laminate tsim
● Tus naj npawb ntawm txheej
Yooj yim stacking yuav suav nrog plaub-txheej PCBs, thaum ntau cov laug cam xav tau kev lamination ua haujlwm. Txawm hais tias ntau qhov nyuaj, cov txheej txheem ntau dua tso cai rau cov neeg tsim qauv kom muaj ntau qhov chaw layout yam tsis muaj kev pheej hmoo ntawm ntsib cov kev daws teeb meem tsis yooj yim.
Feem ntau, yim lossis ntau txheej yuav tsum tau ua kom tau qhov zoo tshaj plaws txheej txheej thiab sib nrug kom ua tau zoo tshaj plaws. Kev siv cov dav hlau zoo thiab lub dav hlau fais fab ntawm cov boards multilayer tuaj yeem txo cov hluav taws xob.
● Txheej txheej
Kev npaj ntawm txheej tooj liab thiab txheej txheej insulating tsim lub voj voog ua haujlwm sib tshooj PCB. Txhawm rau tiv thaiv PCB warping, nws yog ib qho tsim nyog yuav tsum ua kom cov ntu ntu ntawm lub rooj tsav xwm sib luag thiab sib npaug thaum tso tawm cov txheej txheem. Piv txwv li, nyob rau hauv ib tug yim-txheej board, lub thickness ntawm lub thib ob thiab xya txheej yuav tsum zoo ib yam li mus cuag qhov zoo tshaj plaws tshuav nyiaj li cas.
Lub teeb liab txheej yuav tsum nyob ib sab ntawm lub dav hlau, thaum lub dav hlau fais fab thiab lub dav hlau zoo yog nruj me ntsis ua ke ua ke. Nws yog qhov zoo tshaj plaws los siv ntau lub dav hlau hauv av, vim tias lawv feem ntau txo cov hluav taws xob thiab qis hauv av impedance.
● Txheej cov ntaub ntawv hom
Lub thermal, mechanical, thiab hluav taws xob cov khoom ntawm txhua lub substrate thiab lawv cuam tshuam li cas yog qhov tseem ceeb rau kev xaiv cov khoom siv PCB laminate.
Lub rooj tsav xwm Circuit Court feem ntau yog tsim los ntawm cov iav fiber ntau muaj zog, uas muab cov thickness thiab rigidity ntawm PCB. Qee qhov hloov tau yooj yim PCBs tuaj yeem ua los ntawm cov yas uas muaj qhov kub thiab txias.
Cov txheej txheej saum npoo yog ib daim ntawv nyias nyias ua los ntawm cov ntawv ci tooj liab txuas rau lub rooj tsavxwm. Tooj liab muaj nyob rau ntawm ob sab ntawm ob sab PCB, thiab lub thickness ntawm tooj liab txawv raws li tus naj npawb ntawm cov khaubncaws sab nraud povtseg ntawm PCB pawg.
Npog rau sab saum toj ntawm cov ntawv ci tooj liab nrog lub npog ntsej muag kom ua kom cov kab tooj liab tiv nrog lwm yam hlau. Cov khoom siv no yog qhov tseem ceeb los pab cov neeg siv kom tsis txhob muaj qhov tseeb qhov chaw ntawm cov xov hlau jumper.
Ib txheej txheej luam ntawv yog siv rau ntawm daim npog ntsej muag txhawm rau ntxiv cov cim, cov lej thiab cov ntawv kom yooj yim rau kev sib dhos thiab tso cai rau tib neeg kom nkag siab zoo txog lub rooj tsav xwm hauv Circuit Court.
● Txiav txim siab txoj hlua thiab los ntawm qhov
Cov neeg tsim qauv yuav tsum xa cov teeb liab siab ceev ntawm nruab nrab txheej ntawm cov khaubncaws sab nraud povtseg. Qhov no tso cai rau lub dav hlau hauv av los muab kev tiv thaiv uas muaj hluav taws xob tawm los ntawm kev khiav ntawm kev kub ceev.
Qhov kev tso kawm ntawm cov teeb liab theem ze rau lub dav hlau theem tso cai rau cov rov qab tam sim no ntws nyob rau hauv lub dav hlau nyob ib sab, yog li txo txoj kev rov qab inductance. Tsis muaj peev xwm txaus ntawm lub zog uas nyob ib sab thiab cov dav hlau hauv av los muab kev sib cais hauv qab 500 MHz siv cov txheej txheem tsim kho.
● Sib nrug ntawm cov khaubncaws sab nraud povtseg
Vim qhov txo qis capacitance, nruj coupling ntawm lub teeb liab thiab lub dav hlau rov qab tam sim no yog qhov tseem ceeb. Lub zog thiab cov dav hlau hauv av yuav tsum tau nruj ua ke ua ke.
Cov teeb liab txheej yuav tsum nyob ze rau ib leeg txawm tias lawv nyob hauv cov dav hlau uas nyob ib sab. Tight coupling thiab sib nrug ntawm cov khaubncaws sab nraud povtseg yog qhov tseem ceeb rau cov teeb liab tsis cuam tshuam thiab kev ua haujlwm tag nrho.
ua sum
Muaj ntau ntau yam sib txawv PCB board tsim hauv PCB stacking tshuab. Thaum muaj ntau cov khaubncaws sab nraud povtseg, ib txoj hauv kev peb-dimensional uas xav txog cov qauv sab hauv thiab cov txheej txheem saum npoo yuav tsum tau ua ke. Nrog rau kev khiav hauj lwm siab ceev ntawm niaj hnub circuits, ceev faj PCB stack-up tsim yuav tsum tau ua kom zoo dua kev faib tawm thiab txwv kev cuam tshuam. Lub PCB tsim tsis zoo tuaj yeem txo cov teeb liab kis tau tus mob, kev tsim khoom, kev xa hluav taws xob, thiab kev ntseeg tau ntev.