

隨著片式元件0603、0302和fine-pitch、ultra-fine-pitch、BGA、PGA等元件使用的愈來愈廣泛,腐蝕作的印刷模板,焊膏難以釋放,位置度難以保證,然而激光切割模板為保證焊膏的印刷質量提供了堅強的保證。過去用腐蝕作的模板,在印刷過程中需每塊擦洗模板,回爐后,產品返修率高,產品質量難以保證;使用激光模板后,印刷數次才需擦洗一次,回流爐后,產品無錫珠、錫碎,無橋連、無少錫,基本上無返修品,質量明顯上升,節約了人力物力,提高了產品質量。
表面(mian)裝配經常出(chu)現的質(zhi)量缺陷(xian)(xian)有:少(shao)(shao)(shao)錫(xi)(xi)(xi)(xi)、多(duo)錫(xi)(xi)(xi)(xi)、無(wu)錫(xi)(xi)(xi)(xi)、橋(qiao)連(lian)、錫(xi)(xi)(xi)(xi)珠、錫(xi)(xi)(xi)(xi)碎、墓石(shi)、元(yuan)(yuan)件(jian)移(yi)位等(deng)等(deng)。這些缺陷(xian)(xian)的產(chan)生都與(yu)印(yin)刷(shua)(shua)模(mo)板有直接關(guan)系。模(mo)板的厚度(du)選擇不(bu)(bu)當或(huo)張(zhang)網張(zhang)的不(bu)(bu)緊(jin)不(bu)(bu)平(ping),就(jiu)會帶(dai)來(lai)焊膏的釋(shi)放,造成(cheng)(cheng)少(shao)(shao)(shao)錫(xi)(xi)(xi)(xi)、多(duo)錫(xi)(xi)(xi)(xi)等(deng)缺陷(xian)(xian);模(mo)板開(kai)口(kou)尺(chi)寸太(tai)小、開(kai)口(kou)形狀(zhuang)(zhuang)不(bu)(bu)好,就(jiu)會影響焊膏的釋(shi)放,造成(cheng)(cheng)少(shao)(shao)(shao)錫(xi)(xi)(xi)(xi)、無(wu)錫(xi)(xi)(xi)(xi)、錫(xi)(xi)(xi)(xi)珠、錫(xi)(xi)(xi)(xi)碎等(deng)缺陷(xian)(xian);模(mo)板開(kai)口(kou)位置誤差太(tai)大(da)(da),開(kai)口(kou)形狀(zhuang)(zhuang)不(bu)(bu)好,開(kai)口(kou)尺(chi)寸不(bu)(bu)當都可能引起橋(qiao)連(lian)、元(yuan)(yuan)件(jian)移(yi)位、電阻墓石(shi)等(deng)缺陷(xian)(xian)。總(zong)之(zhi),SMT印(yin)刷(shua)(shua)模(mo)板一點質(zhi)量問(wen)題(ti)(ti)都可能會給整個SMT工(gong)(gong)(gong)藝帶(dai)來(lai)質(zhi)量問(wen)題(ti)(ti),造成(cheng)(cheng)整個流水線不(bu)(bu)暢(chang),后(hou)處理(li)工(gong)(gong)(gong)作量加(jia)大(da)(da),質(zhi)量難以保證,物力(li)、人力(li)的大(da)(da)量投入,給SMT的正常生產(chan)帶(dai)來(lai)極(ji)其不(bu)(bu)利的影響,加(jia)大(da)(da)了管理(li)的難度(du),甚至引起整個工(gong)(gong)(gong)廠動作的混(hun)亂(luan),由此(ci)可以看出(chu)印(yin)刷(shua)(shua)模(mo)板對SMT工(gong)(gong)(gong)藝的重要性,采購(gou)部門在采購(gou)模(mo)板時(shi)應(ying)慎重從事,重視質(zhi)量,選擇好的供(gong)應(ying)商(shang),使得SMT的生產(chan)正常運作,減少(shao)(shao)(shao)后(hou)遺癥。
