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   多層線路板PCB，也叫印(yin)制電路(lu)板(ban)(ban)、多(duo)層(ceng)印(yin)制板(ban)(ban)，就是指兩層(ceng)以上(shang)的(de)印(yin)制板(ban)(ban)，它是由幾層(ceng)絕緣基板(ban)(ban)上(shang)的(de)連接導線和(he)裝配(pei)焊(han)接電子(zi)元(yuan)件(jian)用的(de)焊(han)盤組成(cheng)，協(xie)誠達多(duo)層(ceng)PCB既具(ju)(ju)有導通(tong)各層(ceng)線路(lu)，又具(ju)(ju)有相互間絕緣的(de)作(zuo)用.

   多(duo)層(ceng)(ceng)線(xian)路(lu)板(ban)(ban)PCB與(yu)單面板(ban)(ban)、雙面板(ban)(ban)[敏感詞(ci)]的(de)不同就是增加(jia)了內(nei)(nei)部(bu)電(dian)(dian)源層(ceng)(ceng)（保持(chi)內(nei)(nei)電(dian)(dian)層(ceng)(ceng)）和接地層(ceng)(ceng)，電(dian)(dian)源和地線(xian)網絡主要在電(dian)(dian)源層(ceng)(ceng)上布(bu)線(xian)。但是，協誠達多(duo)層(ceng)(ceng)PCB布(bu)線(xian)主要還是以頂層(ceng)(ceng)和底層(ceng)(ceng)為(wei)主，以中間(jian)布(bu)線(xian)層(ceng)(ceng)為(wei)輔。因此(ci)，多(duo)層(ceng)(ceng)PCB的(de)設計與(yu)雙面板(ban)(ban)的(de)設計方法基本(ben)相同，其(qi)關鍵在于如(ru)何(he)優化內(nei)(nei)電(dian)(dian)層(ceng)(ceng)的(de)布(bu)線(xian)，使電(dian)(dian)路(lu)板(ban)(ban)的(de)布(bu)線(xian)更(geng)合理，電(dian)(dian)磁兼(jian)容性更(geng)好。

    多層PCB走(zou)線(xian)(xian) [7]  要把電(dian)源(yuan)(yuan)層、地(di)層和信(xin)(xin)(xin)號(hao)層分開，減(jian)(jian)少電(dian)源(yuan)(yuan)、地(di)、信(xin)(xin)(xin)號(hao)之(zhi)間的(de)(de)干(gan)擾。相(xiang)鄰兩(liang)層印(yin)制板(ban)的(de)(de)線(xian)(xian)條應(ying)(ying)(ying)盡量相(xiang)互垂直或走(zou)斜線(xian)(xian)、曲線(xian)(xian)，不能走(zou)平(ping)行線(xian)(xian)，以減(jian)(jian)少基板(ban)的(de)(de)層間耦合和干(gan)擾。且導(dao)(dao)線(xian)(xian)應(ying)(ying)(ying)盡量走(zou)短線(xian)(xian)，特別是對(dui)(dui)小(xiao)(xiao)信(xin)(xin)(xin)號(hao)電(dian)路來(lai)講，線(xian)(xian)越(yue)短，電(dian)阻越(yue)小(xiao)(xiao)，干(gan)擾越(yue)小(xiao)(xiao) [5]  。同一層上的(de)(de)信(xin)(xin)(xin)號(hao)線(xian)(xian)，改變方向時應(ying)(ying)(ying)避(bi)免銳角拐彎。導(dao)(dao)線(xian)(xian)的(de)(de)寬(kuan)窄，應(ying)(ying)(ying)根據該(gai)電(dian)路對(dui)(dui)電(dian)流及阻抗的(de)(de)要求(qiu)來(lai)確定(ding)，電(dian)源(yuan)(yuan)輸入線(xian)(xian)應(ying)(ying)(ying)大(da)些，信(xin)(xin)(xin)號(hao)線(xian)(xian)可相(xiang)對(dui)(dui)小(xiao)(xiao)一些。對(dui)(dui)一般(ban)數字板(ban)來(lai)說，電(dian)源(yuan)(yuan)輸入線(xian)(xian)線(xian)(xian)寬(kuan)可采用(yong)50～80mil，信(xin)(xin)(xin)號(hao)線(xian)(xian)線(xian)(xian)寬(kuan)可采用(yong)6～10mil。