SMT技术与无铅制程

ISO9001:2000CertifiedHANPAOCO.,LTD.ISO14000:1996CertifiedJianSheRoad,LongShengChunLonghuaTown,BaoanDistrictShenZhenCity,Guangdong,ChinaTel(0755)28126898Fax[phone]E-mail:[e-mail]技朮與Leadfree制程講師:工程部/王華清ISO9001:2000CertifiedHANPAOCO.,LTD.ISO14000:1996CertifiedJianSheRoad,LongShengChunLonghuaTown,BaoanDistrictShenZhenCity,Guangdong,ChinaTel(0755)28126898Fax[phone]E-mail:[e-mail]概念ISO9001:2000CertifiedHANPAOCO.,LTD.ISO14000:1996CertifiedJianSheRoad,LongShengChunLonghuaTown,BaoanDistrictShenZhenCity,Guangdong,ChinaTel(0755)28126898Fax[phone]E-mail:[e-mail]2.表面貼裝(簡稱SMT)SMT是在P.C.B上使用焊錫墊(SolderPad),使其高溫融化與連接器管腳焊在一起的技朮.它的優點是:可以雙面安裝,增加P.C.B使用面積層數,使其布線更合理,更緊湊.它的缺點是:安裝定位要求高,需要耐高溫材料,如(PA6T.PPS.LCP等),成本較高.ISO9001:2000CertifiedHANPAOCO.,LTD.ISO14000:1996CertifiedJianSheRoad,LongShengChunLonghuaTown,BaoanDistrictShenZhenCity,Guangdong,ChinaTel(0755)28126898Fax[phone]E-mail:[e-mail]组装密度高、电子产品体积小、重量轻，贴片元件的体积和重量只有传统插装元件的1/10左右，一般采用SMT之后，电子产品体积缩小40%~60%，重量减轻60%~80%。可靠性高、抗振能力强。焊点缺陷率低。高频特性好。减少了电磁和射频干扰。易于实现自动化，提高生产效率。降低成本达30%~50%。节省材料、能源、设备、人力、时间等。◆为什么要用表面贴装技术(SMT)？电子产品追求小型化，以前使用的穿孔插件元件已无法缩小电子产品功能更完整，所采用的集成电路(IC)已无穿孔元件，特别是大规模、高集成IC，不得不采用表面贴片元件产品批量化，生产自动化，厂方要以低成本高产量，出产优质产品以迎合顾客需求及加强市场竞争力电子元件的发展，集成电路(IC)的开发，半导体材料的多元应用电子科技革命势在必行，追逐国际潮流ISO9001:2000CertifiedHANPAOCO.,LTD.ISO14000:1996CertifiedJianSheRoad,LongShengChunLonghuaTown,BaoanDistrictShenZhenCity,Guangdong,ChinaTel(0755)28126898Fax[phone]E-mail:[e-mail]9001:2000CertifiedHANPAOCO.,LTD.ISO14000:1996CertifiedJianSheRoad,LongShengChunLonghuaTown,BaoanDistrictShenZhenCity,Guangdong,ChinaTel(0755)28126898Fax[phone]E-mail:[e-mail]之優點1,可使封裝密度提高50%-70%;2,可將多個零件合並於一個SMA相;3,可用更高腳數之各種零件;4,提高傳輸速率;5,組裝前無須任何準備工作;6,具有更多且快速之自動化生產能力;7,減少零件貯存空間;8,節省製造廠房,且總成本降低.ISO9001:2000CertifiedHANPAOCO.,LTD.ISO14000:1996CertifiedJianSheRoad,LongShengChunLonghuaTown,BaoanDistrictShenZhenCity,Guangdong,ChinaTel(0755)28126898Fax[phone]E-mail:[e-mail]焊點形成1.焊錫與焊點金屬表面中有氧化膜包覆著。2.焊錫經加熱後Sn與Pb原子便自由作動，同時Flux也將氧化膜除去。3.錫膏中Sn-Pb與焊點中金屬原子產生新的合金成長層。ISO9001:2000CertifiedHANPAOCO.,LTD.ISO14000:1996CertifiedJianSheRoad,LongShengChunLonghuaTown,BaoanDistrictShenZhenCity,Guangdong,ChinaTel(0755)28126898Fax[phone]E-mail:[e-mail]回焊爐及錫膏印刷機ISO9001:2000CertifiedHANPAOCO.,LTD.ISO14000:1996CertifiedJianSheRoad,LongShengChunLonghuaTown,BaoanDistrictShenZhenCity,Guangdong,ChinaTel(0755)28126898Fax[phone]E-mail:[e-mail]波峰焊机器ISO9001:2000CertifiedHANPAOCO.,LTD.ISO14000:1996CertifiedJianSheRoad,LongShengChunLonghuaTown,BaoanDistrictShenZhenCity,Guangdong,ChinaTel(0755)28126898Fax[phone]E-mail:[e-mail]印刷鋼网ISO9001:2000CertifiedHANPAOCO.,LTD.ISO14000:1996CertifiedJianSheRoad,LongShengChunLonghuaTown,BaoanDistrictShenZhenCity,Guangdong,ChinaTel(0755)28126898Fax[phone]E-mail:[e-mail]9001:2000CertifiedHANPAOCO.,LTD.ISO14000:1996CertifiedJianSheRoad,LongShengChunLonghuaTown,BaoanDistrictShenZhenCity,Guangdong,ChinaTel(0755)28126898Fax[phone]E-mail:[e-mail]印刷ISO9001:2000CertifiedHANPAOCO.,LTD.ISO14000:1996CertifiedJianSheRoad,LongShengChunLonghuaTown,BaoanDistrictShenZhenCity,Guangdong,ChinaTel(0755)28126898Fax[phone]E-mail:[e-mail]9001:2000CertifiedHANPAOCO.,LTD.ISO14000:1996CertifiedJianSheRoad,LongShengChunLonghuaTown,BaoanDistrictShenZhenCity,Guangdong,ChinaTel(0755)28126898Fax[phone]E-mail:[e-mail]關於印刷壓力印刷壓力過大時，鋼版前端會彎曲，易造成錫膏滲透，而產生小錫珠。相反如印刷壓力不足，也無法達到良好印刷效果，可能會造成漏印虛印等等現象。適當印刷壓力不但可保護鋼版、刮刀更可確保產品良率穩定。印壓過強造成滲漏易發生短路印壓不足鋼版上錫膏殘留易產生空焊ISO9001:2000CertifiedHANPAOCO.,LTD.ISO14000:1996CertifiedJianSheRoad,LongShengChunLonghuaTown,BaoanDistrictShenZhenCity,Guangdong,ChinaTel(0755)28126898Fax[phone]E-mail:[e-mail]關於基板與鋼版間隙所謂間隙是指基板與鋼版之間的間隔，如果間隙過大時很容易發生錫膏流進反面的鋼版，造成錫膏量過多，易產生短路。相反間隙過小容易發生印刷後錫膏量不足使印刷形狀崩潰，產生空焊現象。間隙過大導致錫膏滲漏間隙過小導致印刷量不足ISO9001:2000CertifiedHANPAOCO.,LTD.ISO14000:1996CertifiedJianSheRoad,LongShengChunLonghuaTown,BaoanDistrictShenZhenCity,Guangdong,ChinaTel(0755)28126898Fax[phone]E-mail:[e-mail]關於印刷速度印刷速度如太快，會發生虛印、漏印或錫膏量不足(錫膏印刷時下降未完全)。相反印刷速度太慢，錫膏雖有充分時間下降，但鋼版與基板接觸時間過長，而使錫膏流至反面，造成錫膏拉絲而出現小錫珠。當錫膏黏度太低，再連續印刷時易造成滲漏下塌而產生短路。良好印刷狀態錫膏量不足印刷速度太快錫膏量過多印刷速度太慢ISO9001:2000CertifiedHANPAOCO.,LTD.ISO14000:1996CertifiedJianSheRoad,LongShengChunLonghuaTown,BaoanDistrictShenZhenCity,Guangdong,ChinaTel(0755)28126898Fax[phone]E-mail:[e-mail]錫膏與印刷條件(參考值)QFP腳距0.65mm0.5mm0.3mm錫粉末形狀:不規則錫粉末形狀:規則○○╳○╳○焊錫粉末最大粒徑75μm50μm30μm錫膏黏度(Pa.s)200~250180~220160~200鋼版厚度(mm)0.20.18~0.150.08~0.10鋼版的開口幅(mm)0.30~0.350.22~0.250.12~0.15鋼版與基板間隙(mm)0.3~0.500刮刀速度(mm/sec)503020~10印壓(kg/cm2)2~1←←刮刀壓力(mm)0.20.2~0.150.1ISO9001:2000