PCB板(ban)有(you)單面、雙面和(he)多(duo)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de),其中多(duo)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)板(ban)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)數(shu)(shu)(shu)(shu)(shu)(shu)(shu)不(bu)(bu)限,目前已經有(you)超(chao)過100層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)PCB,而(er)常見的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)多(duo)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)PCB是(shi)(shi)(shi)四層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)和(he)六層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)板(ban)。那(nei)為何大(da)家會(hui)(hui)有(you)“PCB多(duo)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)板(ban),為什么都是(shi)(shi)(shi)偶(ou)數(shu)(shu)(shu)(shu)(shu)(shu)(shu)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)?”相(xiang)對來說,偶(ou)數(shu)(shu)(shu)(shu)(shu)(shu)(shu)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)PCB確實(shi)要(yao)多(duo)于(yu)奇(qi)(qi)(qi)(qi)(qi)數(shu)(shu)(shu)(shu)(shu)(shu)(shu)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)PCB,也(ye)更有(you)優勢。 01成(cheng)(cheng)(cheng)本(ben)(ben)(ben)(ben)較低(di) 因為少(shao)一(yi)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)介(jie)(jie)質(zhi)和(he)敷箔,奇(qi)(qi)(qi)(qi)(qi)數(shu)(shu)(shu)(shu)(shu)(shu)(shu)PCB板(ban)原材料的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)成(cheng)(cheng)(cheng)本(ben)(ben)(ben)(ben)略低(di)于(yu)偶(ou)數(shu)(shu)(shu)(shu)(shu)(shu)(shu)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)PCB。但(dan)是(shi)(shi)(shi)奇(qi)(qi)(qi)(qi)(qi)數(shu)(shu)(shu)(shu)(shu)(shu)(shu)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)PCB的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)加(jia)(jia)(jia)(jia)(jia)(jia)工(gong)(gong)成(cheng)(cheng)(cheng)本(ben)(ben)(ben)(ben)明顯高于(yu)偶(ou)數(shu)(shu)(shu)(shu)(shu)(shu)(shu)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)PCB。內層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)加(jia)(jia)(jia)(jia)(jia)(jia)工(gong)(gong)成(cheng)(cheng)(cheng)本(ben)(ben)(ben)(ben)相(xiang)同(tong),但(dan)敷箔/核(he)(he)結構(gou)(gou)明顯的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)增(zeng)(zeng)加(jia)(jia)(jia)(jia)(jia)(jia)外(wai)(wai)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)處理(li)(li)成(cheng)(cheng)(cheng)本(ben)(ben)(ben)(ben)。 奇(qi)(qi)(qi)(qi)(qi)數(shu)(shu)(shu)(shu)(shu)(shu)(shu)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)PCB需(xu)要(yao)在(zai)(zai)核(he)(he)結構(gou)(gou)工(gong)(gong)藝(yi)(yi)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)基(ji)礎(chu)上增(zeng)(zeng)加(jia)(jia)(jia)(jia)(jia)(jia)非標(biao)(biao)(biao)(biao)(biao)準(zhun)(zhun)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)疊(die)(die)核(he)(he)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)粘合(he)(he)工(gong)(gong)藝(yi)(yi)。與核(he)(he)結構(gou)(gou)相(xiang)比(bi),在(zai)(zai)核(he)(he)結構(gou)(gou)外(wai)(wai)添加(jia)(jia)(jia)(jia)(jia)(jia)敷箔的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)工(gong)(gong)廠(chang)生產效率將下(xia)(xia)降(jiang)。在(zai)(zai)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)壓(ya)粘合(he)(he)以(yi)(yi)(yi)前,外(wai)(wai)面的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)核(he)(he)需(xu)要(yao)附(fu)加(jia)(jia)(jia)(jia)(jia)(jia)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)工(gong)(gong)藝(yi)(yi)處理(li)(li),這增(zeng)(zeng)加(jia)(jia)(jia)(jia)(jia)(jia)了外(wai)(wai)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)被劃傷和(he)蝕刻(ke)錯誤的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)風險。 02平衡(heng)(heng)結構(gou)(gou)避(bi)免(mian)彎(wan)曲(qu)(qu) 不(bu)(bu)用(yong)(yong)(yong)奇(qi)(qi)(qi)(qi)(qi)數(shu)(shu)(shu)(shu)(shu)(shu)(shu)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)設(she)(she)(she)計(ji)(ji)(ji)PCB的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)最(zui)好(hao)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)理(li)(li)由是(shi)(shi)(shi):奇(qi)(qi)(qi)(qi)(qi)數(shu)(shu)(shu)(shu)(shu)(shu)(shu)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)電路(lu)板(ban)容(rong)(rong)易彎(wan)曲(qu)(qu)。當PCB在(zai)(zai)多(duo)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)電路(lu)粘合(he)(he)工(gong)(gong)藝(yi)(yi)后(hou)冷(leng)卻時,核(he)(he)結構(gou)(gou)和(he)敷箔結構(gou)(gou)冷(leng)卻時不(bu)(bu)同(tong)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)壓(ya)張(zhang)力會(hui)(hui)引(yin)起PCB彎(wan)曲(qu)(qu)。隨著電路(lu)板(ban)厚度的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)增(zeng)(zeng)加(jia)(jia)(jia)(jia)(jia)(jia),具有(you)兩個(ge)不(bu)(bu)同(tong)結構(gou)(gou)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)復合(he)(he)PCB彎(wan)曲(qu)(qu)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)風險就越大(da)。消(xiao)除電路(lu)板(ban)彎(wan)曲(qu)(qu)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)關鍵是(shi)(shi)(shi)采(cai)(cai)用(yong)(yong)(yong)平衡(heng)(heng)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)疊(die)(die)。盡(jin)管一(yi)定程度彎(wan)曲(qu)(qu)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)PCB達到規范(fan)要(yao)求,但(dan)后(hou)續(xu)處理(li)(li)效率將降(jiang)低(di),導致成(cheng)(cheng)(cheng)本(ben)(ben)(ben)(ben)增(zeng)(zeng)加(jia)(jia)(jia)(jia)(jia)(jia)。因為裝配時需(xu)要(yao)特別(bie)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)設(she)(she)(she)備(bei)和(he)工(gong)(gong)藝(yi)(yi),元器件(jian)放置準(zhun)(zhun)確度降(jiang)低(di),故將損害質(zhi)量(liang)。 換個(ge)更容(rong)(rong)易理(li)(li)解的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)說法是(shi)(shi)(shi):在(zai)(zai)PCB流程工(gong)(gong)藝(yi)(yi)中,四層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)板(ban)比(bi)三層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)板(ban)好(hao)控制(zhi),主(zhu)要(yao)是(shi)(shi)(shi)在(zai)(zai)對稱方(fang)(fang)(fang)(fang)面,四層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)板(ban)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)翹(qiao)曲(qu)(qu)程度可以(yi)(yi)(yi)控制(zhi)在(zai)(zai)0.7%以(yi)(yi)(yi)下(xia)(xia)(IPC600的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)標(biao)(biao)(biao)(biao)(biao)準(zhun)(zhun)),但(dan)是(shi)(shi)(shi)三層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)板(ban)尺(chi)寸大(da)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)時候(hou),翹(qiao)曲(qu)(qu)度會(hui)(hui)超(chao)過這個(ge)標(biao)(biao)(biao)(biao)(biao)準(zhun)(zhun),這個(ge)會(hui)(hui)影響SMT貼片和(he)整(zheng)個(ge)產品的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)可靠性(xing),所以(yi)(yi)(yi)一(yi)般設(she)(she)(she)計(ji)(ji)(ji)者(zhe),都不(bu)(bu)設(she)(she)(she)計(ji)(ji)(ji)奇(qi)(qi)(qi)(qi)(qi)數(shu)(shu)(shu)(shu)(shu)(shu)(shu)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)板(ban),即便是(shi)(shi)(shi)奇(qi)(qi)(qi)(qi)(qi)數(shu)(shu)(shu)(shu)(shu)(shu)(shu)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)實(shi)現功(gong)能,也(ye)會(hui)(hui)設(she)(she)(she)計(ji)(ji)(ji)成(cheng)(cheng)(cheng)假偶(ou)數(shu)(shu)(shu)(shu)(shu)(shu)(shu)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng),即將5層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)設(she)(she)(she)計(ji)(ji)(ji)成(cheng)(cheng)(cheng)6層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng),7層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)設(she)(she)(she)計(ji)(ji)(ji)成(cheng)(cheng)(cheng)8層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)板(ban)。 基(ji)于(yu)以(yi)(yi)(yi)上原因,PCB多(duo)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)板(ban)大(da)多(duo)設(she)(she)(she)計(ji)(ji)(ji)成(cheng)(cheng)(cheng)偶(ou)數(shu)(shu)(shu)(shu)(shu)(shu)(shu)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng),奇(qi)(qi)(qi)(qi)(qi)數(shu)(shu)(shu)(shu)(shu)(shu)(shu)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)較少(shao)。 03奇(qi)(qi)(qi)(qi)(qi)數(shu)(shu)(shu)(shu)(shu)(shu)(shu)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)PCB如何平衡(heng)(heng)疊(die)(die)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)、降(jiang)低(di)成(cheng)(cheng)(cheng)本(ben)(ben)(ben)(ben)? 如果(guo)當設(she)(she)(she)計(ji)(ji)(ji)中出現奇(qi)(qi)(qi)(qi)(qi)數(shu)(shu)(shu)(shu)(shu)(shu)(shu)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)PCB時,該怎么辦(ban)呢?用(yong)(yong)(yong)以(yi)(yi)(yi)下(xia)(xia)幾(ji)種(zhong)(zhong)方(fang)(fang)(fang)(fang)法可以(yi)(yi)(yi)達到平衡(heng)(heng)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)疊(die)(die)、降(jiang)低(di)PCB制(zhi)作成(cheng)(cheng)(cheng)本(ben)(ben)(ben)(ben)、避(bi)免(mian)PCB彎(wan)曲(qu)(qu)。 1)一(yi)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)信號(hao)(hao)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)并(bing)利用(yong)(yong)(yong)。如果(guo)設(she)(she)(she)計(ji)(ji)(ji)PCB的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)電源層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)為偶(ou)數(shu)(shu)(shu)(shu)(shu)(shu)(shu)而(er)信號(hao)(hao)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)為奇(qi)(qi)(qi)(qi)(qi)數(shu)(shu)(shu)(shu)(shu)(shu)(shu)可采(cai)(cai)用(yong)(yong)(yong)這種(zhong)(zhong)方(fang)(fang)(fang)(fang)法。增(zeng)(zeng)加(jia)(jia)(jia)(jia)(jia)(jia)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)不(bu)(bu)增(zeng)(zeng)加(jia)(jia)(jia)(jia)(jia)(jia)成(cheng)(cheng)(cheng)本(ben)(ben)(ben)(ben),但(dan)卻可以(yi)(yi)(yi)縮(suo)短(duan)交(jiao)貨(huo)時間、改善PCB質(zhi)量(liang)。 2)增(zeng)(zeng)加(jia)(jia)(jia)(jia)(jia)(jia)一(yi)附(fu)加(jia)(jia)(jia)(jia)(jia)(jia)電源層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)。如果(guo)設(she)(she)(she)計(ji)(ji)(ji)PCB的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)電源層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)為奇(qi)(qi)(qi)(qi)(qi)數(shu)(shu)(shu)(shu)(shu)(shu)(shu)而(er)信號(hao)(hao)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)為偶(ou)數(shu)(shu)(shu)(shu)(shu)(shu)(shu)可采(cai)(cai)用(yong)(yong)(yong)這種(zhong)(zhong)方(fang)(fang)(fang)(fang)法。一(yi)個(ge)簡(jian)單的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)方(fang)(fang)(fang)(fang)法是(shi)(shi)(shi)在(zai)(zai)不(bu)(bu)改變其他設(she)(she)(she)置的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)情(qing)況下(xia)(xia)在(zai)(zai)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)疊(die)(die)中間加(jia)(jia)(jia)(jia)(jia)(jia)一(yi)地層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)。先(xian)按奇(qi)(qi)(qi)(qi)(qi)數(shu)(shu)(shu)(shu)(shu)(shu)(shu)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)PCB中布線,再在(zai)(zai)中間復制(zhi)地層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng),標(biao)(biao)(biao)(biao)(biao)記(ji)剩余的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)。這和(he)加(jia)(jia)(jia)(jia)(jia)(jia)厚地層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)敷箔的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)電氣特性(xing)一(yi)樣。 3)在(zai)(zai)接(jie)近PCB層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)疊(die)(die)中央添加(jia)(jia)(jia)(jia)(jia)(jia)一(yi)空(kong)白信號(hao)(hao)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)。這種(zhong)(zhong)方(fang)(fang)(fang)(fang)法最(zui)小化層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)疊(die)(die)不(bu)(bu)平衡(heng)(heng)性(xing),改善PCB的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)質(zhi)量(liang)。先(xian)按奇(qi)(qi)(qi)(qi)(qi)數(shu)(shu)(shu)(shu)(shu)(shu)(shu)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)布線,再添加(jia)(jia)(jia)(jia)(jia)(jia)一(yi)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)空(kong)白信號(hao)(hao)層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng),標(biao)(biao)(biao)(biao)(biao)記(ji)其余層(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)(ceng)。在(zai)(zai)微波電路(lu)和(he)混合(he)(he)介(jie)(jie)質(zhi)(介(jie)(jie)質(zhi)有(you)不(bu)(bu)同(tong)介(jie)(jie)電常數(shu)(shu)(shu)(shu)(shu)(shu)(shu))電路(lu)中采(cai)(cai)用(yong)(yong)(yong)。