Ntawv luam tawm hauv Circuit Court board tom qab reflow vuam yog nquag rau phaj khoov phaj warping, cov lus hnyav txawm yuav ua rau cov khoom seem vuam, cov duab thiab lwm yam, yuav ua li cas kov yeej nws?

1. Ua tsis zoo ntawm PCB Circuit Board deformation

Hauv qhov tsis siv neeg txheej txheem kab, yog tias lub rooj tsav xwm hauv Circuit Court tsis du, nws yuav ua rau qhov tsis raug qhov tseeb, cov khoom siv tsis tuaj yeem tso lossis teeb tsa rau lub qhov thiab qhov chaw teeb tsa ntawm lub rooj tsavxwm, thiab txawm ua rau lub tshuab tsis siv neeg tsis zoo. Lub rooj tsav xwm hauv vaj huam sib luag thauj khoom nrog cov khoom sib dhos tau khoov tom qab vuam, thiab cov ko taw tiv thaiv tsis yooj yim los txiav kom huv. Cov laug cam tsis tuaj yeem teeb tsa rau hauv lub chassis lossis lub tshuab ntsaws, yog li kev sib dhos cog tau ntsib lub rooj tsav tsheb qaij kuj tseem muaj teeb meem. Tam sim no, txheej txheem thev naus laus zis thev naus laus zis tab tom txhim kho rau qhov ua tau zoo, nrawm thiab nrawm qhia, uas tso rau pem hauv ntej kom siab dua qhov xav tau rau PCB pawg thawj coj ua lub tsev ntawm ntau yam khoom.

IPC tus qauv tshwj xeeb hais tias qhov siab tshaj plaws tuaj yeem hloov pauv tau yog 0.75% rau PCB pawg thawj coj saib nrog cov cuab yeej saum npoo thiab 1.5% rau PCB pawg thawj coj tsis muaj cov cuab yeej siv saum npoo. Qhov tseeb, txhawm rau ua kom tau raws li qhov xav tau ntawm qhov ua tau zoo thiab ua kom nrawm nrawm, qee cov tuam txhab tsim hluav taws xob tsim hluav taws xob muaj qhov xav tau nruj rau kev hloov pauv.

PCB pawg thawj coj yog tsim los ntawm cov ntawv ci tooj liab, cob, iav iav thiab lwm yam ntaub ntawv, txhua yam uas muaj lub cev thiab tshuaj sib txawv. Tom qab nias ua ke, cov cua sov uas seem yuav tsis tuaj yeem tshwm sim, ua rau deformation. Nyob rau tib lub sijhawm hauv txheej txheem txheej txheem PCB, los ntawm qhov kub thiab txias, kev txiav cov tshuab, txheej txheem ntub thiab lwm cov txheej txheem, yuav ua rau muaj kev cuam tshuam loj rau ntawm cov phaj deformation, luv luv tuaj yeem ua rau PCB deformation nyuaj, yuav ua li cas thiaj txo lossis tshem tawm qhov tshwm sim los ntawm cov khoom sib txawv thiab kev ua haujlwm, kev hloov pauv ntawm PCB cov tuam txhab yog ib qho teeb meem nyuaj tshaj plaws.

2. Ua rau kev tshuaj xyuas ntawm deformation

Kev hloov pauv ntawm PCB pawg thawj coj yuav tsum tau kawm los ntawm cov khoom siv, qauv, kev faib tawm duab, txheej txheem txheej txheem thiab lwm yam. Daim ntawv no yuav tshuaj xyuas thiab piav qhia ntau yam laj thawj rau kev hloov pauv thiab txhim kho txoj hauv kev.

Qhov tsis sib xws ntawm cov tooj liab saum npoo ntawm lub rooj tsav xwm hauv Circuit Court yuav ua rau qhov khoov thiab ua rau ntawm pawg thawj coj saib tsis zoo.

Ntawm cov phiaj xwm phiaj xwm dav dav muaj thaj tsam loj ntawm cov ntawv ci tooj liab rau hauv av, qee zaum Vcc txheej tau tsim thaj tsam loj ntawm cov ntawv ci tooj liab, thaum cov cheeb tsam loj ntawm cov ntawv ci tooj liab tsis tuaj yeem faib sib npaug hauv tib lub rooj sib tham hauv Circuit Court, yuav ua rau tsis sov thiab txias ceev, cov phiajcim hauv Circuit Court, tau kawg, tseem tuaj yeem ua kom sov cov cua txias txias, Yog tias kev nthuav dav thiab kev sib cog ua ke tsis tuaj yeem tshwm sim los ntawm kev sib txawv thiab kev hloov pauv, lub sijhawm no yog qhov ntsuas kub ntawm lub rooj tsavxwm tau mus txog qhov siab tshaj ntawm Tg tus nqi, lub rooj tsavxwm yuav pib muag, ua rau muaj kev hloov pauv mus tas li.

Cov ntsiab lus sib txuas (ViAs) ntawm cov khaubncaws sab nraud povtseg ntawm lub rooj tsavxwm txwv kev nthuav dav thiab txo qis ntawm pawg thawj coj

Tam sim no, lub rooj sib tham hauv Circuit Court feem ntau yog pawg thawj coj saib ntau tus neeg, thiab yuav muaj rivets zoo li qhov txuas (VIAS) nruab nrab ntawm txheej thiab txheej, qhov txuas txuas tau muab faib ua hauv qhov, qhov muag tsis pom thiab qhov faus qhov, qhov twg muaj qhov txuas sib txuas txwv qhov cuam tshuam ntawm phaj nthuav dav thiab txo qis, tseem yuav ua ncaj qha ua rau phaj khoov thiab phaj warping.

Qhov hnyav ntawm lub rooj tsav xwm hauv Circuit nws tus kheej tuaj yeem ua rau lub rooj tsavxwm sag thiab deform

Cov vuam siv hluav taws xob dav dav yuav siv cov saw hlau los tsav lub rooj tsav xwm hluav taws xob hauv lub tshuab ua kom sov txuas mus rau tom ntej, uas yog, thaum ob sab ntawm lub rooj tsavxwm thaum lub tshuab ua haujlwm puv ntoob los txhawb nqa tag nrho lub rooj tsavxwm, yog lub rooj tsavxwm siab dua qhov hnyav, lossis qhov loj ntawm pawg thawj coj loj dhau, vim hais tias tus nqi ntawm nws tus kheej thiab tshwm sim hauv nruab nrab ntawm qhov kev nyuaj siab tshwm sim, ua rau phaj khoov.

Qhov tob ntawm V-txiav thiab cov hlua txuas yuav cuam tshuam qhov deformation ntawm lub vaj huam sib luag

Yeej, V-txiav yog tus ua txhaum ntawm kev rhuav tshem cov txheej txheem ntawm pawg thawj coj, vim tias V-txiav yog los txiav qhov nqaj ntawm daim ntawv loj, yog li nws yooj yim deform qhov chaw ntawm V-txiav.

2.1 Txheeb xyuas qhov cuam tshuam ntawm cov ntaub ntawv nias, cov qauv thiab cov duab ntawm phaj deformation

PCB lub rooj tsavxwm yog tsim los ntawm nias lub rooj tsav xwm tseem ceeb, cov ntawv ib nrab ua kom khov thiab txheej txheej tooj liab. Lub rooj tsavxwm tseem ceeb thiab cov ntawv tooj liab tau ua kom sov thiab deformed thaum nias. Tus nqi ntawm kev hloov pauv nyob ntawm qhov sib npaug ntawm kev nthuav dav cua sov (CTE) ntawm ob yam khoom.

Cov coefficient ntawm thermal nthuav dav (CTE) ntawm cov ntawv ci tooj liab yog hais txog

Z-cTe ntawm qhov zoo tib yam FR-4 substrate ntawm Tg point yog.

Saum TG taw tes, nws yog (250-350) x10-6, thiab x-cTE feem ntau zoo ib yam li cov ntawv ci tooj liab vim muaj cov ntaub iav.