1. 不銹(xiu)鋼(gang)化學(xue)鍍銅的應(ying)用(yong)


 不(bu)銹鋼化學鍍銅應(ying)用于電子工業(ye)、計算機(ji)工業(ye)及航空工業(ye)中電子元(yuan)件的高效電磁干(gan)擾的屏(ping)蔽。



2. 不銹(xiu)鋼基體上化學鍍銅存在的問題


  久久99國產精品久久99果凍傳媒: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. 不銹鋼(gang)化學(xue)鍍銅工藝流程


  NiCr不銹鋼(經過600℃真空(kong)熱(re)處理(li))→化(hua)學除(chu)油[氫(qing)氧(yang)化(hua)鈉(NaOH)10%(質量分(fen)數(shu))]→水(shui)(shui)(shui)洗→熱(re)水(shui)(shui)(shui)洗→除(chu)銹(鹽酸1:1溶液,溫度80~100℃,時(shi)間(jian)5min)→水(shui)(shui)(shui)洗→干燥→除(chu)氫(qing)(在烘(hong)箱中溫度200℃,時(shi)間(jian)2h)→酸處理(li)[稀(xi)硫酸5%(質量分(fen)數(shu)),時(shi)間(jian)1~5min]→水(shui)(shui)(shui)洗→去離子水(shui)(shui)(shui)洗→化(hua)學鍍銅(tong)→水(shui)(shui)(shui)洗→抗(kang)銅(tong)變色處理(li)(苯并三氮唑1g/L,溫度65℃,時(shi)間(jian)2min)→純水(shui)(shui)(shui)洗→熱(re)純水(shui)(shui)(shui)洗→干燥。



4. 化學(xue)鍍銅溶液(ye)成分及工藝(yi)條件見表4-39


表 39.jpg



5. 化(hua)學鍍銅溶液(ye)的配制


 先將(jiang)硫酸銅(tong)和酒石酸鉀(jia)鈉分別(bie)用(yong)(yong)純水溶解,然后(hou)將(jiang)硫酸銅(tong)溶液(ye)(ye)(ye)在攪拌下(xia)加(jia)入(ru)(ru)(ru)酒石酸鉀(jia)鈉溶液(ye)(ye)(ye)中(zhong),銅(tong)離子被酒石酸離子絡(luo)(luo)合(he)成藍(lan)色(se)絡(luo)(luo)合(he)物。再(zai)將(jiang)氯化鎳用(yong)(yong)少量(liang)水溶解后(hou)攪拌加(jia)入(ru)(ru)(ru),再(zai)加(jia)入(ru)(ru)(ru)甲醛(quan)溶液(ye)(ye)(ye),攪拌均(jun)勻(yun)。將(jiang)氫氧化鈉用(yong)(yong)純水溶解成200g/L 的濃溶液(ye)(ye)(ye)待(dai)用(yong)(yong)。在開始化學(xue)鍍銅(tong)前(qian),逐步在攪拌下(xia)加(jia)入(ru)(ru)(ru)藍(lan)色(se)絡(luo)(luo)合(he)液(ye)(ye)(ye)中(zhong),使溶液(ye)(ye)(ye)pH達(da)到12 左右(用(yong)(yong)9~13精密(mi)pH試紙測量(liang)),最后(hou)將(jiang)穩定劑亞(ya)鐵(tie)氯化鉀(jia)、聚乙二(er)醇用(yong)(yong)少量(liang)水溶解后(hou)攪拌加(jia)入(ru)(ru)(ru),乙醇可直接加(jia)入(ru)(ru)(ru),最后(hou)用(yong)(yong)純水加(jia)入(ru)(ru)(ru)至(zhi)溶液(ye)(ye)(ye)的規定體(ti)積,攪拌均(jun)勻(yun)后(hou)放入(ru)(ru)(ru)不銹鋼件即可開始化學(xue)鍍銅(tong)。



6. 操作要點


 ①. 裝(zhuang)載量


  按(an)照每升鍍液裝載2d㎡計算。


 ②. 除氫和攪拌(ban)


  不(bu)銹(xiu)鋼對(dui)氫(qing)滲很敏感,工(gong)件在(zai)酸(suan)洗過(guo)(guo)程(cheng)中(zhong)(zhong)氫(qing)會(hui)(hui)滲人到(dao)基(ji)(ji)體(ti)中(zhong)(zhong),如果(guo)不(bu)除(chu)氫(qing),化(hua)學(xue)(xue)鍍(du)(du)(du)銅(tong)(tong)鍍(du)(du)(du)層(ceng)致密小孔覆蓋在(zai)不(bu)銹(xiu)鋼表(biao)面(mian)(mian)(mian)后(hou),氫(qing)氣(qi)無法(fa)(fa)逸出,造成(cheng)(cheng)很大(da)的(de)(de)(de)(de)應(ying)(ying)(ying)力(li),使鍍(du)(du)(du)層(ceng)起泡(pao),加上(shang)化(hua)學(xue)(xue)鍍(du)(du)(du)銅(tong)(tong)本身(shen)伴隨著(zhu)析氫(qing)過(guo)(guo)程(cheng),氫(qing)氣(qi)會(hui)(hui)殘(can)留在(zai)基(ji)(ji)體(ti)與鍍(du)(du)(du)層(ceng)金屬的(de)(de)(de)(de)晶格中(zhong)(zhong),增大(da)內應(ying)(ying)(ying)力(li),嚴重地(di)減(jian)弱基(ji)(ji)體(ti)與鍍(du)(du)(du)層(ceng)的(de)(de)(de)(de)結合(he)(he)強度(du)(du)(du)(du)。為此,從兩(liang)方面(mian)(mian)(mian)著(zhu)手(shou)解決鍍(du)(du)(du)層(ceng)起泡(pao)問題。其(qi)一是(shi)把經過(guo)(guo)去油、酸(suan)洗后(hou)的(de)(de)(de)(de)工(gong)件在(zai)化(hua)學(xue)(xue)鍍(du)(du)(du)銅(tong)(tong)前進行熱處(chu)理,除(chu)去滲入到(dao)基(ji)(ji)體(ti)中(zhong)(zhong)的(de)(de)(de)(de)氫(qing),熱處(chu)理溫(wen)度(du)(du)(du)(du)和時(shi)間條件經實驗確定為180~200℃,2小時(shi),鍍(du)(du)(du)層(ceng)無鼓(gu)泡(pao),鍍(du)(du)(du)層(ceng)結合(he)(he)力(li)合(he)(he)格。溫(wen)度(du)(du)(du)(du)過(guo)(guo)低或時(shi)間過(guo)(guo)短(duan)仍有(you)輕微鼓(gu)泡(pao),溫(wen)度(du)(du)(du)(du)過(guo)(guo)高(gao)或時(shi)間過(guo)(guo)長都容易使表(biao)面(mian)(mian)(mian)再(zai)次(ci)生(sheng)成(cheng)(cheng)不(bu)易去除(chu)的(de)(de)(de)(de)氧化(hua)皮(pi),又需(xu)要較長時(shi)間的(de)(de)(de)(de)強酸(suan)處(chu)理,酸(suan)洗時(shi)氫(qing)會(hui)(hui)再(zai)次(ci)滲入基(ji)(ji)體(ti)。在(zai)所選定的(de)(de)(de)(de)溫(wen)度(du)(du)(du)(du)和時(shi)間下雖(sui)表(biao)面(mian)(mian)(mian)會(hui)(hui)有(you)新(xin)的(de)(de)(de)(de)氧化(hua)膜生(sheng)成(cheng)(cheng),但使用稀硫酸(suan)短(duan)時(shi)間酸(suan)洗即可,以免再(zai)次(ci)滲氫(qing)。其(qi)二(er)是(shi)在(zai)化(hua)學(xue)(xue)鍍(du)(du)(du)銅(tong)(tong)過(guo)(guo)程(cheng)中(zhong)(zhong),采用某種攪拌(ban)(空氣(qi)攪拌(ban)或機械攪拌(ban)),有(you)利于(yu)銅(tong)(tong)離子向(xiang)工(gong)件表(biao)面(mian)(mian)(mian)擴散,防止和減(jian)少副反(fan)應(ying)(ying)(ying)產(chan)物(wu)銅(tong)(tong)粉(即Cu2O)的(de)(de)(de)(de)生(sheng)成(cheng)(cheng),而(er)且有(you)利于(yu)反(fan)應(ying)(ying)(ying)產(chan)物(wu)氫(qing)氣(qi)脫離工(gong)件表(biao)面(mian)(mian)(mian)。通過(guo)(guo)上(shang)述(shu)兩(liang)種方法(fa)(fa)有(you)效地(di)解決了鍍(du)(du)(du)層(ceng)鼓(gu)泡(pao)問題,提高(gao)了鍍(du)(du)(du)層(ceng)與基(ji)(ji)體(ti)的(de)(de)(de)(de)結合(he)(he)強度(du)(du)(du)(du)。


 ③. 催化活(huo)性劑-鎳離(li)子


  在(zai)化學鍍銅溶液中加入(ru)少量鎳離子后,鍍層性質得到改(gai)善,在(zai)鍍銅層中含有微量的(de)鎳,形成(cheng)Cu89Ni11金屬化合物,它具有最佳(jia)的(de)催化活性,提(ti)高鍍層的(de)催化活性。


④. 穩定劑的控制


  在(zai)化(hua)(hua)學(xue)鍍(du)(du)銅(tong)(tong)(tong)(tong)過程中,甲(jia)醛(quan)能將二(er)價銅(tong)(tong)(tong)(tong)離子還原為金屬(shu)銅(tong)(tong)(tong)(tong)鍍(du)(du)層,還存(cun)在(zai)有(you)副(fu)反應,即不完全(quan)反應生成(cheng)暗(an)紅色的(de)(de)氧化(hua)(hua)亞(ya)銅(tong)(tong)(tong)(tong)(Cu2O),它形(xing)成(cheng)微粒懸浮(fu)在(zai)鍍(du)(du)液(ye)中,呈膠(jiao)體狀(zhuang)態,極難用(yong)過濾(lv)除(chu)去(qu),若與(yu)銅(tong)(tong)(tong)(tong)共沉積,使銅(tong)(tong)(tong)(tong)鍍(du)(du)層疏松粗糙,與(yu)基體結合力極差。氧化(hua)(hua)亞(ya)銅(tong)(tong)(tong)(tong)被甲(jia)醛(quan)還原成(cheng)金屬(shu)微粒,又成(cheng)為自(zi)催化(hua)(hua)中心(xin),使鍍(du)(du)液(ye)自(zi)發分解,消耗了鍍(du)(du)液(ye)中的(de)(de)有(you)效成(cheng)分。為了抑制(zhi)副(fu)反應的(de)(de)發生,加入穩(wen)定(ding)劑,以(yi)提(ti)高(gao)鍍(du)(du)液(ye)的(de)(de)穩(wen)定(ding)性。但是(shi),過量的(de)(de)穩(wen)定(ding)劑的(de)(de)加人(ren),又成(cheng)了化(hua)(hua)學(xue)鍍(du)(du)銅(tong)(tong)(tong)(tong)反應的(de)(de)催化(hua)(hua)毒性劑,顯著降低化(hua)(hua)學(xue)鍍(du)(du)的(de)(de)速率(lv),甚至停(ting)鍍(du)(du),故(gu)選用(yong)穩(wen)定(ding)劑,并控制(zhi)其很(hen)低的(de)(de)適宜含量,對提(ti)高(gao)鍍(du)(du)液(ye)穩(wen)定(ding)性有(you)效。


⑤. 防銅層變色處理


  對銅(tong)層(ceng)進行(xing)防變色(se)處理,在(zai)鍍(du)銅(tong)層(ceng)表面形成一(yi)層(ceng)穩定的絡(luo)合膜,隔絕外界浸(jin)蝕性(xing)物質對鍍(du)銅(tong)層(ceng)的作(zuo)用,使鍍(du)銅(tong)層(ceng)保(bao)持本色(se)一(yi)定的時(shi)間。苯并三氮唑要(yao)先(xian)用乙醇(chun)溶解好,然后加入熱蒸餾(liu)水(shui)中。防變色(se)處理的溫度不(bu)低于65℃,時(shi)間不(bu)少于2min,否則防變色(se)達(da)不(bu)到效果。



7. 鍍層(ceng)結合強度檢測(ce)-劃痕實驗法(fa)


 在(zai)鍍(du)層表面(mian)(mian)用(yong)刀片劃(hua)(hua)出1mm間距的(de)直(zhi)行線和90°交(jiao)錯(cuo)的(de)橫行線形成小(xiao)方格。觀察劃(hua)(hua)痕(hen)交(jiao)錯(cuo)處鍍(du)層有無起層,進(jin)一步用(yong)黏性高(gao)的(de)膠帶(dai)貼于(yu)劃(hua)(hua)痕(hen)表面(mian)(mian),再撕下(xia)膠帶(dai),以銅層不(bu)脫落(luo)為合格。



8. 不銹鋼化學鍍(du)銅常見故障、可(ke)能原因及糾正方法見表4-40.


表 40.jpg