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    印制(zhi)(zhi)電(dian)(dian)(dian)(dian)路(lu)板(ban)(ban)(ban)的(de)(de)(de)(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)鍍(du)(du)(du)(du)工藝，隨(sui)著電(dian)(dian)(dian)(dian)子設備的(de)(de)(de)(de)(de)(de)(de)(de)高功能(neng)化(hua)(hua)和(he)小(xiao)型化(hua)(hua)的(de)(de)(de)(de)(de)(de)(de)(de)飛速發展(zhan)，電(dian)(dian)(dian)(dian)子設備的(de)(de)(de)(de)(de)(de)(de)(de)主要(yao)(yao)結構(gou)件印制(zhi)(zhi)電(dian)(dian)(dian)(dian)路(lu)板(ban)(ban)(ban)，為適應高密度(du)、高精度(du)、微型化(hua)(hua)的(de)(de)(de)(de)(de)(de)(de)(de)需要(yao)(yao)，印制(zhi)(zhi)電(dian)(dian)(dian)(dian)路(lu)板(ban)(ban)(ban)的(de)(de)(de)(de)(de)(de)(de)(de)制(zhi)(zhi)造技(ji)術(shu)與工藝有了很大(da)的(de)(de)(de)(de)(de)(de)(de)(de)變化(hua)(hua)，就其(qi)中涉及(ji)到的(de)(de)(de)(de)(de)(de)(de)(de)表(biao)面處理技(ji)術(shu)變化(hua)(hua)也(ye)是(shi)很大(da)的(de)(de)(de)(de)(de)(de)(de)(de)。眾所(suo)周知(zhi)，電(dian)(dian)(dian)(dian)鍍(du)(du)(du)(du)的(de)(de)(de)(de)(de)(de)(de)(de)目(mu)的(de)(de)(de)(de)(de)(de)(de)(de)在(zai)于為制(zhi)(zhi)造中的(de)(de)(de)(de)(de)(de)(de)(de)印制(zhi)(zhi)電(dian)(dian)(dian)(dian)路(lu)板(ban)(ban)(ban)提(ti)供(gong)其(qi)本(ben)身欠佳及(ji)并(bing)非固有的(de)(de)(de)(de)(de)(de)(de)(de)表(biao)面特性(xing)(xing)。從結構(gou)件到印制(zhi)(zhi)電(dian)(dian)(dian)(dian)路(lu)板(ban)(ban)(ban)的(de)(de)(de)(de)(de)(de)(de)(de)表(biao)面處理，盡管不僅相(xiang)同，但其(qi)電(dian)(dian)(dian)(dian)鍍(du)(du)(du)(du)本(ben)身其(qi)基(ji)本(ben)原理是(shi)相(xiang)同的(de)(de)(de)(de)(de)(de)(de)(de)。當然印制(zhi)(zhi)電(dian)(dian)(dian)(dian)路(lu)板(ban)(ban)(ban)的(de)(de)(de)(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)鍍(du)(du)(du)(du)相(xiang)對比(bi)較(jiao)簡單，鍍(du)(du)(du)(du)種也(ye)較(jiao)少。就印制(zhi)(zhi)電(dian)(dian)(dian)(dian)路(lu)板(ban)(ban)(ban)化(hua)(hua)學(xue)鍍(du)(du)(du)(du)和(he)電(dian)(dian)(dian)(dian)鍍(du)(du)(du)(du)的(de)(de)(de)(de)(de)(de)(de)(de)主要(yao)(yao)目(mu)的(de)(de)(de)(de)(de)(de)(de)(de)是(shi)確保印制(zhi)(zhi)電(dian)(dian)(dian)(dian)路(lu)板(ban)(ban)(ban)的(de)(de)(de)(de)(de)(de)(de)(de)可焊性(xing)(xing)、防護性(xing)(xing)、導電(dian)(dian)(dian)(dian)性(xing)(xing)和(he)耐磨(mo)性(xing)(xing)。

　　印制電(dian)(dian)路(lu)(lu)板(ban)(ban)實現電(dian)(dian)裝(zhuang)途徑，就是(shi)(shi)(shi)采用錫焊(han)(han)(han)(han)(han)和熔焊(han)(han)(han)(han)(han)。無論(lun)是(shi)(shi)(shi)接(jie)插(cha)件(jian)還是(shi)(shi)(shi)表(biao)面(mian)(mian)(mian)(mian)貼裝(zhuang)件(jian)，雖然(ran)電(dian)(dian)裝(zhuang)的(de)工藝(yi)方法不(bu)盡相同，但對(dui)電(dian)(dian)鍍層(ceng)的(de)技(ji)(ji)術要(yao)求是(shi)(shi)(shi)一樣的(de)。對(dui)于(yu)印制電(dian)(dian)路(lu)(lu)板(ban)(ban)表(biao)面(mian)(mian)(mian)(mian)鍍層(ceng)最(zui)(zui)重(zhong)要(yao)的(de)是(shi)(shi)(shi)其(qi)可焊(han)(han)(han)(han)(han)性能(neng)，它(ta)是(shi)(shi)(shi)保證接(jie)插(cha)件(jian)或(huo)表(biao)面(mian)(mian)(mian)(mian)貼裝(zhuang)件(jian)與電(dian)(dian)路(lu)(lu)所(suo)在(zai)位置應達到牢固的(de)結(jie)合。而可靠性最(zui)(zui)終是(shi)(shi)(shi)由焊(han)(han)(han)(han)(han)接(jie)情(qing)況決定。現代生產技(ji)(ji)術通常(chang)采用波峰焊(han)(han)(han)(han)(han)或(huo)浸(jin)焊(han)(han)(han)(han)(han)在(zai)印制電(dian)(dian)路(lu)(lu)板(ban)(ban)上(shang)同時(shi)對(dui)上(shang)千(qian)個焊(han)(han)(han)(han)(han)點進(jin)行(xing)焊(han)(han)(han)(han)(han)接(jie)，然(ran)而由于(yu)電(dian)(dian)連接(jie)點與熔融焊(han)(han)(han)(han)(han)料(liao)相接(jie)觸的(de)時(shi)間只有一、二秒鐘，因(yin)此元件(jian)的(de)表(biao)面(mian)(mian)(mian)(mian)快速而完(wan)全的(de)被焊(han)(han)(han)(han)(han)料(liao)所(suo)潤濕(shi)是(shi)(shi)(shi)很重(zhong)要(yao)的(de)。焊(han)(han)(han)(han)(han)料(liao)在(zai)被焊(han)(han)(han)(han)(han)表(biao)面(mian)(mian)(mian)(mian)上(shang)擴展使器件(jian)表(biao)面(mian)(mian)(mian)(mian)潤濕(shi)，同時(shi)由于(yu)毛(mao)細(xi)管作用使焊(han)(han)(han)(han)(han)料(liao)最(zui)(zui)后貫穿并(bing)充滿接(jie)點的(de)各個部位而完(wan)成焊(han)(han)(han)(han)(han)接(jie)過程。如果最(zui)(zui)初(chu)的(de)潤濕(shi)作用效果極差就會產生有缺陷的(de)焊(han)(han)(han)(han)(han)點或(huo)虛焊(han)(han)(han)(han)(han)。所(suo)以，選擇可焊(han)(han)(han)(han)(han)性能(neng)好的(de)電(dian)(dian)鍍或(huo)涂(tu)覆層(ceng)是(shi)(shi)(shi)非常(chang)重(zhong)要(yao)的(de)技(ji)(ji)術工作。

　　從長期的生(sheng)產實踐經驗證明新的沉(chen)積鉛錫(xi)(xi)合(he)金層（錫(xi)(xi)含量(liang)為60%）可(ke)(ke)焊(han)(han)(han)(han)性最佳，這是(shi)(shi)經過漂浮錫(xi)(xi)焊(han)(han)(han)(han)測(ce)到的結果。但是(shi)(shi)由(you)于(yu)鉛錫(xi)(xi)合(he)金存放階段(duan)過長，致使可(ke)(ke)焊(han)(han)(han)(han)性能(neng)下降，即是(shi)(shi)能(neng)焊(han)(han)(han)(han)接也很困難，特別是(shi)(shi)存放在(zai)濕(shi)熱(re)的工作環境條件下，表(biao)(biao)(biao)(biao)面(mian)(mian)(mian)變(bian)化(hua)更大(da)，焊(han)(han)(han)(han)接更加困難。現有很多(duo)廠商研(yan)制(zhi)(zhi)(zhi)(zhi)出(chu)防護工藝(yi)方(fang)(fang)法。盡管如(ru)此，為了(le)更加適應(ying)電(dian)子設備微型化(hua)、多(duo)功(gong)能(neng)化(hua)的需要(yao)，印制(zhi)(zhi)(zhi)(zhi)電(dian)路板(ban)(ban)制(zhi)(zhi)(zhi)(zhi)造技術(shu)不斷更新，目前(qian)普(pu)遍(bian)采(cai)用(yong)的SMOBC工藝(yi)，仍屬于(yu)熱(re)浸(jin)錫(xi)(xi)鉛合(he)金（含63%、37%）涂(tu)(tu)覆層其可(ke)(ke)焊(han)(han)(han)(han)性能(neng)最高，它的最重(zhong)要(yao)的優點(dian)是(shi)(shi)全部(bu)能(neng)潤濕(shi)基底金屬從而與(yu)基體有著更牢固、更穩(wen)定的冶(ye)金方(fang)(fang)面(mian)(mian)(mian)的連接，形(xing)成(cheng)光(guang)澤的涂(tu)(tu)覆層表(biao)(biao)(biao)(biao)面(mian)(mian)(mian)。由(you)于(yu)SMT用(yong)印制(zhi)(zhi)(zhi)(zhi)電(dian)路板(ban)(ban)的出(chu)現，為保證表(biao)(biao)(biao)(biao)面(mian)(mian)(mian)貼裝器件的貼焊(han)(han)(han)(han)質量(liang)，從工藝(yi)角度出(chu)發，開發和研(yan)制(zhi)(zhi)(zhi)(zhi)新型涂(tu)(tu)覆層-預涂(tu)(tu)抗熱(re)助焊(han)(han)(han)(han)劑、化(hua)學浸(jin)鎳(nie)/金等表(biao)(biao)(biao)(biao)面(mian)(mian)(mian)涂(tu)(tu)覆工藝(yi)已大(da)量(liang)應(ying)用(yong)在(zai)表(biao)(biao)(biao)(biao)面(mian)(mian)(mian)貼裝雙面(mian)(mian)(mian)、多(duo)層印制(zhi)(zhi)(zhi)(zhi)電(dian)路板(ban)(ban)上。

　　除了(le)電(dian)(dian)鍍(du)(du)或(huo)熱浸錫鉛合(he)金(jin)鍍(du)(du)涂(tu)覆(fu)層(ceng)及其(qi)它(ta)先進的(de)(de)(de)(de)(de)涂(tu)覆(fu)或(huo)電(dian)(dian)鍍(du)(du)技(ji)術(shu)(shu)外，為了(le)有良好的(de)(de)(de)(de)(de)電(dian)(dian)氣(qi)(qi)接觸(chu)性能，印制(zhi)電(dian)(dian)路(lu)板(ban)(ban)的(de)(de)(de)(de)(de)插頭(tou)(tou)部位需(xu)(xu)要(yao)進行表面處理。這是因為無論設(she)備(bei)或(huo)儀器多么復雜，總是存著(zhu)電(dian)(dian)氣(qi)(qi)連接問題(ti)。電(dian)(dian)源輸入需(xu)(xu)要(yao)連接、器件和設(she)備(bei)的(de)(de)(de)(de)(de)電(dian)(dian)路(lu)內部也需(xu)(xu)要(yao)更多的(de)(de)(de)(de)(de)連接，從大型電(dian)(dian)子設(she)備(bei)到微型化的(de)(de)(de)(de)(de)裝置，其(qi)效能都在(zai)不(bu)同程度上(shang)(shang)取決于連接的(de)(de)(de)(de)(de)材料和鍍(du)(du)涂(tu)覆(fu)層(ceng)的(de)(de)(de)(de)(de)正(zheng)確選擇(ze)，也就(jiu)說選擇(ze)接點表面鍍(du)(du)層(ceng)是十分重要(yao)的(de)(de)(de)(de)(de)，特別(bie)是要(yao)求(qiu)接觸(chu)力小而電(dian)(dian)壓(ya)又低(di)印制(zhi)電(dian)(dian)路(lu)板(ban)(ban)的(de)(de)(de)(de)(de)插頭(tou)(tou)部位其(qi)重要(yao)作用就(jiu)更為突出(chu)。在(zai)當前印制(zhi)電(dian)(dian)路(lu)板(ban)(ban)制(zhi)造工(gong)藝上(shang)(shang)采取鍍(du)(du)硬金(jin)方法或(huo)以鎳(nie)打底的(de)(de)(de)(de)(de)鍍(du)(du)金(jin)或(huo)浸金(jin)工(gong)藝技(ji)術(shu)(shu)。實用證明該鍍(du)(du)鎳(nie)金(jin)的(de)(de)(de)(de)(de)工(gong)藝方法適合(he)印制(zhi)電(dian)(dian)路(lu)板(ban)(ban)插頭(tou)(tou)對鍍(du)(du)層(ceng)電(dian)(dian)氣(qi)(qi)及耐磨性能的(de)(de)(de)(de)(de)技(ji)術(shu)(shu)要(yao)求(qiu)。

　　從(cong)表面處理技(ji)術的發展趨勢(shi)分析，隨著微電子技(ji)術的飛速發展，印制(zhi)電路板制(zhi)造(zao)技(ji)術與工藝(yi)，都會研制(zhi)出更為先進的表面加工方(fang)法，但總的發展趨勢(shi)是朝(chao)著少污染、易操作和工藝(yi)穩(wen)定的方(fang)向(xiang)進展。