1. 不(bu)銹鋼化學鍍銅的應用


 不銹鋼(gang)化學(xue)鍍銅應用(yong)于電(dian)子工(gong)業、計算機工(gong)業及航空工(gong)業中(zhong)電(dian)子元件的(de)高效電(dian)磁干擾的(de)屏(ping)蔽(bi)。



2. 不銹鋼基體(ti)上化學(xue)鍍銅存(cun)在的問題(ti)


  香蕉視頻app下載蘋果版:不銹鋼基體上化學鍍銅易造成鍍層鼓泡,這不僅影響了鍍層與基體的結合力,而且直接影響到外觀質量。為此,將鍍前酸處理過的不銹鋼放在烘箱中加熱,以除去酸洗時滲入到基體的氫,采用此方法解決了鍍層起泡問題,得到所需要的化學鍍銅層。



3. 不(bu)銹鋼化(hua)學鍍銅工藝(yi)流程


  NiCr不銹鋼(經(jing)過(guo)600℃真空熱處理(li))→化(hua)學(xue)除(chu)油(you)[氫(qing)氧化(hua)鈉(NaOH)10%(質量(liang)分(fen)數)]→水(shui)(shui)洗(xi)→熱水(shui)(shui)洗(xi)→除(chu)銹(鹽酸1:1溶液,溫(wen)度80~100℃,時(shi)間(jian)5min)→水(shui)(shui)洗(xi)→干燥→除(chu)氫(qing)(在烘箱中溫(wen)度200℃,時(shi)間(jian)2h)→酸處理(li)[稀硫酸5%(質量(liang)分(fen)數),時(shi)間(jian)1~5min]→水(shui)(shui)洗(xi)→去離子水(shui)(shui)洗(xi)→化(hua)學(xue)鍍銅(tong)(tong)→水(shui)(shui)洗(xi)→抗銅(tong)(tong)變色處理(li)(苯并三氮(dan)唑1g/L,溫(wen)度65℃,時(shi)間(jian)2min)→純(chun)水(shui)(shui)洗(xi)→熱純(chun)水(shui)(shui)洗(xi)→干燥。



4. 化學鍍銅(tong)溶液成分及(ji)工(gong)藝(yi)條件見表4-39


表 39.jpg



5. 化學鍍銅溶液的配制(zhi)


 先將(jiang)(jiang)(jiang)硫(liu)酸銅(tong)和酒(jiu)石(shi)酸鉀(jia)鈉(na)分別(bie)用純水(shui)(shui)(shui)溶(rong)(rong)(rong)解(jie),然后(hou)(hou)(hou)(hou)將(jiang)(jiang)(jiang)硫(liu)酸銅(tong)溶(rong)(rong)(rong)液(ye)(ye)在(zai)攪(jiao)(jiao)(jiao)(jiao)拌下(xia)加(jia)(jia)入(ru)(ru)(ru)(ru)酒(jiu)石(shi)酸鉀(jia)鈉(na)溶(rong)(rong)(rong)液(ye)(ye)中(zhong),銅(tong)離(li)(li)子被酒(jiu)石(shi)酸離(li)(li)子絡(luo)(luo)合成(cheng)藍色絡(luo)(luo)合物。再(zai)將(jiang)(jiang)(jiang)氯化(hua)鎳用少量(liang)水(shui)(shui)(shui)溶(rong)(rong)(rong)解(jie)后(hou)(hou)(hou)(hou)攪(jiao)(jiao)(jiao)(jiao)拌加(jia)(jia)入(ru)(ru)(ru)(ru),再(zai)加(jia)(jia)入(ru)(ru)(ru)(ru)甲醛溶(rong)(rong)(rong)液(ye)(ye),攪(jiao)(jiao)(jiao)(jiao)拌均勻。將(jiang)(jiang)(jiang)氫氧化(hua)鈉(na)用純水(shui)(shui)(shui)溶(rong)(rong)(rong)解(jie)成(cheng)200g/L 的濃溶(rong)(rong)(rong)液(ye)(ye)待用。在(zai)開始(shi)化(hua)學(xue)鍍銅(tong)前,逐步在(zai)攪(jiao)(jiao)(jiao)(jiao)拌下(xia)加(jia)(jia)入(ru)(ru)(ru)(ru)藍色絡(luo)(luo)合液(ye)(ye)中(zhong),使溶(rong)(rong)(rong)液(ye)(ye)pH達(da)到12 左右(用9~13精密(mi)pH試紙測(ce)量(liang)),最(zui)后(hou)(hou)(hou)(hou)將(jiang)(jiang)(jiang)穩(wen)定(ding)(ding)劑(ji)亞鐵氯化(hua)鉀(jia)、聚乙二醇用少量(liang)水(shui)(shui)(shui)溶(rong)(rong)(rong)解(jie)后(hou)(hou)(hou)(hou)攪(jiao)(jiao)(jiao)(jiao)拌加(jia)(jia)入(ru)(ru)(ru)(ru),乙醇可直接(jie)加(jia)(jia)入(ru)(ru)(ru)(ru),最(zui)后(hou)(hou)(hou)(hou)用純水(shui)(shui)(shui)加(jia)(jia)入(ru)(ru)(ru)(ru)至溶(rong)(rong)(rong)液(ye)(ye)的規定(ding)(ding)體(ti)積(ji),攪(jiao)(jiao)(jiao)(jiao)拌均勻后(hou)(hou)(hou)(hou)放入(ru)(ru)(ru)(ru)不銹鋼件即可開始(shi)化(hua)學(xue)鍍銅(tong)。



6. 操作要點


 ①. 裝載量


  按照(zhao)每(mei)升鍍液裝(zhuang)載2d㎡計(ji)算。


 ②. 除氫和攪(jiao)拌


  不(bu)銹鋼對氫(qing)(qing)(qing)(qing)(qing)滲(shen)很敏感,工件(jian)在(zai)(zai)(zai)(zai)酸(suan)洗(xi)過程中氫(qing)(qing)(qing)(qing)(qing)會滲(shen)人(ren)到基(ji)(ji)體(ti)中,如果不(bu)除氫(qing)(qing)(qing)(qing)(qing),化學(xue)鍍(du)(du)(du)(du)(du)(du)銅(tong)鍍(du)(du)(du)(du)(du)(du)層(ceng)致密小(xiao)(xiao)孔(kong)覆蓋在(zai)(zai)(zai)(zai)不(bu)銹鋼表(biao)面后,氫(qing)(qing)(qing)(qing)(qing)氣無(wu)法(fa)逸出,造成(cheng)很大的應力,使鍍(du)(du)(du)(du)(du)(du)層(ceng)起泡(pao),加上化學(xue)鍍(du)(du)(du)(du)(du)(du)銅(tong)本身伴隨著(zhu)析氫(qing)(qing)(qing)(qing)(qing)過程,氫(qing)(qing)(qing)(qing)(qing)氣會殘留在(zai)(zai)(zai)(zai)基(ji)(ji)體(ti)與鍍(du)(du)(du)(du)(du)(du)層(ceng)金屬的晶(jing)格(ge)中,增大內應力,嚴(yan)重地減弱基(ji)(ji)體(ti)與鍍(du)(du)(du)(du)(du)(du)層(ceng)的結(jie)合(he)強度(du)。為此(ci),從兩方面著(zhu)手解(jie)決鍍(du)(du)(du)(du)(du)(du)層(ceng)起泡(pao)問題。其一(yi)是把經(jing)過去油、酸(suan)洗(xi)后的工件(jian)在(zai)(zai)(zai)(zai)化學(xue)鍍(du)(du)(du)(du)(du)(du)銅(tong)前進行(xing)熱處(chu)理(li),除去滲(shen)入(ru)到基(ji)(ji)體(ti)中的氫(qing)(qing)(qing)(qing)(qing),熱處(chu)理(li)溫(wen)(wen)度(du)和(he)(he)時間(jian)(jian)(jian)條(tiao)件(jian)經(jing)實驗(yan)確定為180~200℃,2小(xiao)(xiao)時,鍍(du)(du)(du)(du)(du)(du)層(ceng)無(wu)鼓泡(pao),鍍(du)(du)(du)(du)(du)(du)層(ceng)結(jie)合(he)力合(he)格(ge)。溫(wen)(wen)度(du)過低或時間(jian)(jian)(jian)過短仍有(you)輕(qing)微鼓泡(pao),溫(wen)(wen)度(du)過高或時間(jian)(jian)(jian)過長都容(rong)易(yi)使表(biao)面再次(ci)生成(cheng)不(bu)易(yi)去除的氧化皮,又需(xu)要較長時間(jian)(jian)(jian)的強酸(suan)處(chu)理(li),酸(suan)洗(xi)時氫(qing)(qing)(qing)(qing)(qing)會再次(ci)滲(shen)入(ru)基(ji)(ji)體(ti)。在(zai)(zai)(zai)(zai)所選定的溫(wen)(wen)度(du)和(he)(he)時間(jian)(jian)(jian)下雖表(biao)面會有(you)新的氧化膜生成(cheng),但(dan)使用稀硫酸(suan)短時間(jian)(jian)(jian)酸(suan)洗(xi)即(ji)可,以免再次(ci)滲(shen)氫(qing)(qing)(qing)(qing)(qing)。其二是在(zai)(zai)(zai)(zai)化學(xue)鍍(du)(du)(du)(du)(du)(du)銅(tong)過程中,采用某種攪拌(ban)(空(kong)氣攪拌(ban)或機械攪拌(ban)),有(you)利于(yu)銅(tong)離子向工件(jian)表(biao)面擴散(san),防止和(he)(he)減少副反應產(chan)物銅(tong)粉(即(ji)Cu2O)的生成(cheng),而且有(you)利于(yu)反應產(chan)物氫(qing)(qing)(qing)(qing)(qing)氣脫離工件(jian)表(biao)面。通(tong)過上述兩種方法(fa)有(you)效(xiao)地解(jie)決了鍍(du)(du)(du)(du)(du)(du)層(ceng)鼓泡(pao)問題,提高了鍍(du)(du)(du)(du)(du)(du)層(ceng)與基(ji)(ji)體(ti)的結(jie)合(he)強度(du)。


 ③. 催化(hua)活性劑-鎳(nie)離子


  在化(hua)學鍍銅(tong)溶液中(zhong)加入少量鎳離子(zi)后,鍍層性(xing)質得到改善,在鍍銅(tong)層中(zhong)含有(you)微量的(de)(de)鎳,形成Cu89Ni11金屬化(hua)合物(wu),它具有(you)最佳的(de)(de)催(cui)化(hua)活性(xing),提高鍍層的(de)(de)催(cui)化(hua)活性(xing)。


④. 穩定劑的(de)控制


  在化學(xue)鍍(du)(du)(du)銅(tong)過程中(zhong),甲醛能將二(er)價銅(tong)離子(zi)還(huan)原(yuan)為(wei)金屬銅(tong)鍍(du)(du)(du)層,還(huan)存在有副反應,即不完(wan)全(quan)反應生成暗紅色的氧化亞銅(tong)(Cu2O),它(ta)形成微粒懸浮在鍍(du)(du)(du)液(ye)中(zhong),呈膠體狀態,極(ji)難用過濾(lv)除去,若與銅(tong)共沉積,使(shi)(shi)銅(tong)鍍(du)(du)(du)層疏松粗(cu)糙,與基體結合(he)力極(ji)差。氧化亞銅(tong)被(bei)甲醛還(huan)原(yuan)成金屬微粒,又成為(wei)自催化中(zhong)心(xin),使(shi)(shi)鍍(du)(du)(du)液(ye)自發(fa)(fa)分(fen)解,消(xiao)耗了鍍(du)(du)(du)液(ye)中(zhong)的有效(xiao)成分(fen)。為(wei)了抑制副反應的發(fa)(fa)生,加入穩定劑(ji),以提高(gao)鍍(du)(du)(du)液(ye)的穩定性。但是(shi),過量(liang)的穩定劑(ji)的加人,又成了化學(xue)鍍(du)(du)(du)銅(tong)反應的催化毒性劑(ji),顯著(zhu)降低化學(xue)鍍(du)(du)(du)的速率,甚至停鍍(du)(du)(du),故(gu)選(xuan)用穩定劑(ji),并控制其(qi)很低的適宜(yi)含量(liang),對提高(gao)鍍(du)(du)(du)液(ye)穩定性有效(xiao)。


⑤. 防(fang)銅層變(bian)色(se)處理(li)


  對銅(tong)層(ceng)進行防(fang)變(bian)(bian)色(se)處(chu)理(li),在(zai)鍍銅(tong)層(ceng)表(biao)面(mian)形成一(yi)層(ceng)穩定(ding)的(de)絡合膜,隔絕外界浸蝕性物質對鍍銅(tong)層(ceng)的(de)作用,使鍍銅(tong)層(ceng)保持本色(se)一(yi)定(ding)的(de)時間(jian)。苯并(bing)三(san)氮唑要先用乙醇溶解(jie)好,然后加入熱蒸餾水中。防(fang)變(bian)(bian)色(se)處(chu)理(li)的(de)溫(wen)度(du)不(bu)低于65℃,時間(jian)不(bu)少(shao)于2min,否(fou)則防(fang)變(bian)(bian)色(se)達不(bu)到效果。



7. 鍍層結合強度檢測-劃痕實驗法(fa)


 在鍍層表(biao)面用(yong)刀片劃(hua)出1mm間距的直行(xing)線(xian)和(he)90°交錯的橫行(xing)線(xian)形成小方格。觀(guan)察(cha)劃(hua)痕(hen)交錯處鍍層有(you)無(wu)起層,進一(yi)步用(yong)黏(nian)性高的膠(jiao)帶貼于劃(hua)痕(hen)表(biao)面,再撕下(xia)膠(jiao)帶,以銅層不脫落為(wei)合格。



8. 不(bu)銹鋼(gang)化學(xue)鍍銅常見(jian)故障、可能原因及糾正方(fang)法見(jian)表4-40.


表 40.jpg