SMT( Printed Circuit Board Assembly , PCBA ) tseem hu ua nto mount technology.Thaum lub sij hawm tsim cov txheej txheem, cov tshuaj nplaum yog rhuab thiab melted nyob rau hauv ib qho chaw cua sov, kom cov PCB pads muaj kev ntseeg siab ua ke nrog nto mount Cheebtsam los ntawm solder paste alloy.Peb hu cov txheej txheem no reflow soldering.Feem ntau ntawm cov rooj sib tham hauv Circuit Court yog nquag rau board dabtsi yog khoov thiab warping thaum ua Reflow (reflow soldering).Hauv qhov xwm txheej hnyav, nws tuaj yeem ua rau cov khoom xws li khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob Nyob rau hauv txoj kab kev sib txuas, yog tias lub PCB ntawm lub rooj tsav xwm Circuit Court tsis tiaj tus, nws yuav ua rau qhov chaw tsis raug, cov khoom tsis tuaj yeem muab tso rau hauv lub qhov thiab qhov chaw mount pads ntawm lub rooj tsavxwm, thiab txawm tias lub tshuab tsis siv neeg ntxig yuav puas.Lub rooj tsavxwm nrog cov khoom yog khoov tom qab vuam, thiab cov khoom taw qhia yog qhov nyuaj rau txiav kom zoo.Lub rooj tsavxwm tsis tuaj yeem ntsia tau rau ntawm lub chassis lossis lub qhov (socket) hauv lub tshuab, yog li nws tseem cuam tshuam rau lub rooj sib txoos cog kom ntsib lub rooj tsavxwm warping.Tam sim no, cov ntawv luam tawm tau nkag mus rau lub sijhawm ntawm qhov chaw mounting thiab nti mounting, thiab cov nroj tsuag sib dhos yuav tsum muaj cov kev cai nruj dua thiab nruj dua rau board warping.
Raws li US IPC-6012 (1996 Edition) "Specification thiab Performance Specification rau Rigid Printed Boards ", qhov siab tshaj plaws uas tso cai rau kev ua tsov rog thiab kev tsis sib haum xeeb rau saum npoo ntawm cov ntawv luam tawm yog 0.75%, thiab 1.5% rau lwm lub rooj tsavxwm. tam sim no, lub warpage tso cai los ntawm ntau yam khoom siv hluav taws xob sib dhos, tsis hais ob sab lossis ntau txheej, 1.6mm thickness, feem ntau yog 0.70 ~ 0.75%.
Rau ntau SMT thiab BGA boards, qhov yuav tsum tau yog 0.5%.Qee lub tuam txhab hluav taws xob tau hais kom nce tus qauv ntawm warpage rau 0.3%.Txoj kev kuaj warpage yog raws li GB4677.5-84 lossis IPC-TM-650.2.4.22B.Muab cov ntawv luam tawm rau ntawm lub platform uas tau lees paub, ntxig tus pin xeem mus rau qhov chaw uas qhov degree ntawm warpage yog qhov loj tshaj, thiab faib cov kab uas hla ntawm tus pin xeem los ntawm qhov ntev ntawm ntug nkhaus ntawm cov ntawv luam tawm los xam cov warpage ntawm lub luam ntawv board.Lub curvature ploj mus.
Yog li nyob rau hauv cov txheej txheem ntawm PCB manufacturing, Dab tsi yog vim li cas rau kev khoov thiab warping ntawm lub rooj tsavxwm?
Qhov ua rau ntawm txhua phaj dabtsi yog khoov thiab phaj warping tej zaum yuav txawv, tab sis nws yuav tsum tau muab tag nrho vim hais tias ntawm cov kev nyuaj siab thov rau lub phaj uas yog ntau tshaj qhov kev nyuab siab uas cov khoom phaj tuaj yeem tiv taus.Thaum lub phaj raug kev ntxhov siab tsis sib xws lossis Thaum lub peev xwm ntawm txhua qhov chaw ntawm lub rooj tsavxwm los tiv thaiv kev ntxhov siab tsis sib xws, qhov tshwm sim ntawm board dabtsi yog khoov thiab board warping yuav tshwm sim.Cov hauv qab no yog cov ntsiab lus ntawm plaub qhov laj thawj tseem ceeb ntawm phaj dabtsi yog khoov thiab phaj warping.
1. Qhov tsis sib xws ntawm qhov chaw tooj liab ntawm lub rooj tsav xwm hauv Circuit Court yuav ua rau kev khoov thiab sib tsoo ntawm lub rooj tsavxwm.
Feem ntau, thaj tsam loj ntawm cov ntawv ci tooj liab yog tsim los ntawm lub rooj tsav xwm hauv Circuit Court rau hauv av.Qee zaum thaj tsam loj ntawm cov ntawv ci tooj liab kuj tsim los ntawm Vcc txheej.Thaum cov ntaub ntawv loj ntawm cov tooj liab no tsis tuaj yeem muab sib npaug ntawm tib lub rooj tsav xwm Circuit Court Lub sijhawm no, nws yuav ua rau muaj teeb meem ntawm qhov tsis sib xws ntawm kev nqus cua sov thiab cua sov dissipation.Tau kawg, lub rooj tsav xwm hauv Circuit Court kuj yuav nthuav dav thiab cog lus nrog cua sov.Yog tias qhov nthuav dav thiab kev cog lus tsis tuaj yeem ua tiav tib lub sijhawm, nws yuav ua rau muaj kev ntxhov siab thiab deformation sib txawv.Lub sijhawm no, yog tias qhov ntsuas kub ntawm lub rooj tsavxwm tau mus txog Tg Lub siab txwv ntawm tus nqi, lub rooj tsavxwm yuav pib muag, ua rau lub cev tsis muaj zog.
2. Qhov hnyav ntawm lub rooj tsav xwm hauv Circuit Court nws tus kheej yuav ua rau lub rooj tsavxwm dents thiab deform
Feem ntau, lub tshuab hluav taws xob reflow siv cov saw hlau los tsav lub rooj tsav xwm hauv Circuit Court rau hauv lub qhov cub reflow, uas yog, ob sab ntawm lub rooj tsavxwm yog siv los ua fulcrums los txhawb tag nrho lub rooj tsavxwm.Yog tias muaj qhov hnyav ntawm lub rooj tsavxwm, lossis qhov loj ntawm lub rooj tsavxwm loj heev, Nws yuav ua rau muaj kev nyuaj siab nyob rau hauv nruab nrab vim muaj cov noob, ua rau lub phaj khoov.
3. Qhov tob ntawm V-Cut thiab cov hlua txuas txuas yuav cuam tshuam rau qhov deformation ntawm jigsaw
Yeej, V-Cut yog tus neeg ua txhaum uas rhuav tshem cov qauv ntawm lub rooj tsavxwm, vim tias V-Cut txiav V-shaped grooves ntawm daim ntawv loj, yog li V-Cut yog qhov ua rau deformation.
4. Cov ntsiab lus txuas (vias) ntawm txhua txheej ntawm lub rooj tsav xwm Circuit Court yuav txwv qhov nthuav dav thiab kev cog lus ntawm lub rooj tsavxwm
Niaj hnub no Circuit Court boards feem ntau yog ntau txheej boards, thiab yuav muaj rivet zoo li cov ntsiab lus txuas (ntawm) ntawm cov txheej.Cov ntsiab lus sib txuas tau muab faib ua los ntawm qhov, qhov qhov muag tsis pom thiab qhov faus.Qhov twg muaj cov ntsiab lus txuas, lub rooj tsavxwm yuav raug txwv.Cov txiaj ntsig ntawm kev nthuav dav thiab kev cog lus kuj tseem yuav ua rau lub phaj dabtsi yog khoov thiab phaj warping.
Yog li cas peb tuaj yeem tiv thaiv qhov teeb meem ntawm board warping thaum lub sijhawm tsim khoom? Nov yog ob peb txoj hauv kev uas kuv vam tias yuav pab tau koj.
1. Txo qhov cuam tshuam ntawm qhov kub thiab txias ntawm lub rooj tsavxwm
Txij li thaum "kub" yog lub hauv paus ntsiab lus ntawm lub rooj tsavxwm kev ntxhov siab, tsuav yog qhov kub ntawm lub qhov cub reflow txo qis los yog tus nqi ntawm cov cua sov thiab cua txias ntawm lub rooj tsavxwm hauv lub qhov cub reflow yog qeeb, qhov tshwm sim ntawm phaj dabtsi yog khoov thiab warpage tuaj yeem ua tau zoo heev. txo.Txawm li cas los xij, lwm yam kev mob tshwm sim tuaj yeem tshwm sim, xws li solder luv Circuit Court.
2. Siv daim ntawv Tg siab
Tg yog lub iav hloov pauv kub, uas yog, qhov kub thiab txias ntawm cov khoom hloov ntawm lub khob iav mus rau lub xeev roj hmab.Qhov qis dua Tg tus nqi ntawm cov khoom siv, lub rooj tsavxwm nrawm nrawm dua tom qab nkag mus rau hauv qhov cub reflow, thiab lub sijhawm nws yuav siv los ua cov roj hmab muag muag Nws tseem yuav ntev dua, thiab qhov deformation ntawm lub rooj tsavxwm yuav yog qhov hnyav dua. .Kev siv cov ntawv Tg siab dua tuaj yeem ua rau nws muaj peev xwm tiv taus kev ntxhov siab thiab deformation, tab sis tus nqi ntawm cov khoom txheeb ze kuj tseem siab dua.
3. Ua kom lub thickness ntawm lub rooj tsavxwm Circuit Court Yuav kom ua tiav lub hom phiaj ntawm kev sib zog thiab thinner rau ntau yam khoom siv hluav taws xob, lub thickness ntawm lub rooj tsavxwm tau tso tseg 1.0mm, 0.8mm, lossis txawm tias 0.6mm.Xws li ib tug tuab yuav tsum ua kom lub rooj tsavxwm los ntawm deforming tom qab lub reflow rauv, uas yog heev nyuaj.Nws raug pom zoo tias yog tias tsis muaj qhov yuav tsum tau ua kom lub teeb thiab nyias, lub thickness ntawm lub rooj tsavxwm yuav tsum yog 1.6 hli, uas tuaj yeem txo qhov kev pheej hmoo ntawm kev khoov thiab deformation ntawm lub rooj tsavxwm. 4. Txo qhov loj ntawm lub rooj tsav xwm hauv Circuit Court thiab txo cov kev sib tw Txij li feem ntau ntawm cov reflow furnaces siv chains los tsav lub Circuit Court board rau pem hauv ntej, qhov loj ntawm lub Circuit Court board yuav yog vim nws tus kheej hnyav, dent thiab deformation nyob rau hauv lub reflow furnace, yog li sim muab lub ntev sab ntawm lub Circuit Court board. raws li tus ntug ntawm lub rooj tsavxwm.Ntawm cov saw hlau ntawm reflow rauv, qhov kev nyuaj siab thiab deformation tshwm sim los ntawm qhov hnyav ntawm lub rooj tsav xwm Circuit Court tuaj yeem txo.Kev txo qis ntawm cov panels kuj yog raws li qhov laj thawj no.Uas yog hais tias, thaum dhau lub cub tawg, sim siv lub ntug nqaim kom dhau lub qhov cub kom deb li deb tau.Tus nqi ntawm kev nyuaj siab deformation. 5. Siv lub tshuab hluav taws xob siv hluav taws xob Yog tias cov txheej txheem saum toj no nyuaj rau ua tiav, qhov kawg yog siv cov cab kuj / cov qauv los txo qhov deformation.Yog vim li cas vim li cas lub reflow carrier / template tuaj yeem txo qhov khoov ntawm lub phaj yog vim nws vam tias nws yog thermal expansion lossis txias contraction.Lub tais tuaj yeem tuav lub rooj tsav xwm hauv Circuit Court thiab tos kom txog thaum qhov kub ntawm lub rooj tsavxwm Circuit Court qis dua tus nqi Tg thiab pib rov ua kom tawv dua, thiab nws tuaj yeem tswj tau qhov qub. Yog hais tias ib txheej txheej pallet tsis tuaj yeem txo qhov deformation ntawm lub rooj tsavxwm Circuit Court, yuav tsum tau ntxiv ib lub hau rau clamp lub rooj tsavxwm nrog rau sab sauv thiab sab pallets.Qhov no tuaj yeem txo qhov teeb meem ntawm Circuit Court board deformation los ntawm reflow rauv.Txawm li cas los xij, lub tshuab hluav taws xob no yog qhov kim heev, thiab kev siv tes ua haujlwm yuav tsum tau muab thiab rov ua dua cov tais. 6. Siv Router es tsis txhob V-Cut siv sub-board Txij li thaum V-Cut yuav rhuav tshem cov txheej txheem ntawm lub zog ntawm lub rooj tsavxwm ntawm lub rooj tsavxwm, sim tsis txhob siv V-Cut sub-board lossis txo qhov tob ntawm V-Cut.
7. Peb lub ntsiab lus khiav hauv engineering tsim: A. Cov txheej txheem ntawm interlayer prepregs yuav tsum yog symmetrical, piv txwv li, rau 6-txheej boards, lub thickness ntawm 1 ~ 2 thiab 5 ~ 6 txheej thiab tus naj npawb ntawm prepregs yuav tsum zoo ib yam, txwv tsis pub nws yooj yim rau warp tom qab lamination. B. Multi-layer core board thiab prepreg yuav tsum siv tib lub chaw muag khoom cov khoom. C. Qhov chaw ntawm cov qauv Circuit Court ntawm sab A thiab sab B ntawm txheej txheej yuav tsum nyob ze li sai tau.Yog tias sab A yog tooj liab loj, thiab sab B tsuas muaj ob peb kab, cov ntawv luam tawm no yuav yooj yim warp tom qab etching.Yog tias thaj tsam ntawm cov kab ntawm ob sab sib txawv dhau lawm, koj tuaj yeem ntxiv qee qhov kev ywj pheej ntawm daim nyias nyias kom sib npaug. 8. Lub latitude thiab longitude ntawm lub prepreg: Tom qab lub prepreg yog laminated, lub warp thiab weft shrinkage tus nqi sib txawv, thiab warp thiab weft cov lus qhia yuav tsum txawv thaum lub sij hawm blanking thiab lamination.Txwv tsis pub, nws yog ib qho yooj yim los ua kom tiav lub rooj tsavxwm rau warp tom qab lamination, thiab nws yog ib qho nyuaj rau kho nws txawm hais tias lub siab yog siv rau lub ci board.Ntau qhov laj thawj rau kev ua tsov rog ntawm lub rooj tsavxwm multilayer yog tias cov prepregs tsis txawv ntawm qhov warp thiab weft cov lus qhia thaum lub sij hawm lamination, thiab lawv yog stacked random. Cov txheej txheem kom paub qhov txawv ntawm warp thiab weft cov lus qhia: lub dov kev taw qhia ntawm lub prepreg nyob rau hauv ib yob yog warp kev taw qhia, thaum lub dav kev taw qhia yog lub weft direction;rau lub rooj tsavxwm tooj liab, sab ntev yog cov kev taw qhia weft thiab sab luv yog cov kev taw qhia warp.Yog tias koj tsis paub meej, thov hu rau lub chaw tsim khoom lossis tus neeg muag khoom nug. 9. Baking board ua ntej txiav: Lub hom phiaj ntawm ci lub rooj tsavxwm ua ntej txiav cov tooj liab clad laminate (150 degrees Celsius, lub sij hawm 8 ± 2 teev) yog kom tshem tawm cov dej noo nyob rau hauv lub rooj tsavxwm, thiab tib lub sij hawm ua rau cov resin nyob rau hauv lub rooj tsavxwm kiag li solidify, thiab ntxiv tshem tawm cov khoom. tshuav kev ntxhov siab nyob rau hauv lub rooj tsavxwm, uas yog ib qho tseem ceeb rau kev tiv thaiv lub rooj tsavxwm los ntawm warping.Pab.Tam sim no, ntau ob sab thiab ntau txheej boards tseem ua raws li cov kauj ruam ntawm kev ci ua ntej lossis tom qab blanking.Txawm li cas los xij, muaj kev zam rau qee lub tsev lag luam phaj.Tam sim no PCB ziab lub sij hawm cov kev cai ntawm ntau yam PCB factories kuj tsis sib haum, xws li ntawm 4 mus rau 10 teev.Nws raug pom zoo kom txiav txim siab raws li qib ntawm cov ntawv luam tawm uas tsim thiab cov neeg siv khoom xav tau rau warpage.Ci tom qab txiav rau hauv ib lub jigsaw los yog blanking tom qab tag nrho cov block yog ci.Ob txoj kev yog ua tau.Nws raug nquahu kom ci lub rooj tsavxwm tom qab txiav.Sab hauv txheej board kuj yuav tsum tau ci ... 10. Ntxiv rau kev ntxhov siab tom qab lamination: Tom qab lub rooj tsavxwm ntau txheej yog kub-nias thiab txias-nias, nws raug tshem tawm, txiav los yog milled tawm lub burrs, thiab ces muab tso rau hauv lub qhov cub ntawm 150 degrees Celsius rau 4 teev, thiaj li hais tias cov kev ntxhov siab nyob rau hauv lub rooj tsavxwm yog. maj mam tso tawm thiab cov resin yog kho kom zoo.Cov kauj ruam no tsis tuaj yeem tshem tawm.
11. Lub phaj nyias yuav tsum tau ncaj thaum lub sij hawm electroplating: Thaum lub 0.4 ~ 0.6mm ultra-thin multilayer board yog siv rau nto electroplating thiab qauv electroplating, tshwj xeeb clamping rollers yuav tsum tau ua.Tom qab lub phaj nyias yog clamped ntawm lub tsheb npav ya ntawm txoj kab tsis siv neeg electroplating, ib puag ncig stick yog siv los clamp tag nrho cov tsheb npav ya.Cov chais yog strung ua ke kom ncaj txhua daim hlau ntawm cov chais kom cov hlau tom qab plating yuav tsis deformed.Yog tias tsis muaj qhov ntsuas no, tom qab electroplating txheej tooj ntawm 20 mus rau 30 microns, daim ntawv yuav khoov thiab nws nyuaj rau kho nws. 12. Txias ntawm lub rooj tsavxwm tom qab cua kub leveling: Thaum cov ntawv luam tawm yog qib los ntawm huab cua kub, nws raug cuam tshuam los ntawm qhov kub thiab txias ntawm lub tshuab ntxhua khaub ncaws (txog 250 degrees Celsius).Tom qab muab tshem tawm, nws yuav tsum tau muab tso rau ntawm lub tiaj tiaj marble lossis steel phaj rau ntuj txias, thiab tom qab ntawd xa mus rau lub tshuab ua haujlwm tom qab ntxuav.Qhov no yog qhov zoo rau kev tiv thaiv warpage ntawm lub rooj tsavxwm.Hauv qee lub chaw tsim khoom, txhawm rau txhawm rau txhim kho qhov ci ntawm cov hlau lead-tin nto, cov laug cam tau muab tso rau hauv dej txias tam sim ntawd tom qab cua kub tau leveled, thiab muab tshem tawm tom qab ob peb feeb tom qab ua tiav.Qhov kev cuam tshuam kub thiab txias no tuaj yeem ua rau warping ntawm qee yam ntawm cov laug cam.Twisted, txheej los yog blistered.Tsis tas li ntawd, lub txaj huab cua flotation tuaj yeem ntsia tau rau ntawm cov khoom siv kom txias. 13. Kev kho mob ntawm warped board: Nyob rau hauv lub Hoobkas tswj tau zoo, cov ntawv luam tawm yuav raug kuaj xyuas 100% flatness thaum kuaj zaum kawg.Txhua lub rooj tsav xwm tsis tsim nyog yuav raug xaiv tawm, muab tso rau hauv qhov cub, ci ntawm 150 degrees Celsius hauv qab hnyav rau 3-6 teev, thiab txias ib txwm nyob rau hauv qhov hnyav.Tom qab ntawd tshem tawm lub siab kom tshem tawm lub rooj tsavxwm, thiab xyuas qhov flatness, yog li ntawd ib feem ntawm lub rooj tsavxwm yuav tau txais kev cawmdim, thiab qee lub rooj tsavxwm yuav tsum tau muab ci thiab nias ob lossis peb zaug ua ntej lawv tuaj yeem ua tau theem.Yog hais tias cov txheej txheem tiv thaiv kev tiv thaiv saum toj no tsis raug siv, qee qhov ntawm cov laug cam yuav tsis muaj txiaj ntsig thiab tsuas yog muab pov tseg.
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