元器件及焊盘镀层与Sn63Pb37焊料的匹配性分析  

Matching Analysis of Components and Pads Coating with Sn63Pb37 Solder

作　　者：李青 周强 张志杰[2] 洪元[1] 潘兴旺 刘大勇[1] LI Qing;ZHOU Qiang;ZHANG Zhijie;HONG Yuan;PAN Xingwang;LIU Dayong(Space Star Technology Co.,Ltd.,Beijing 100095,China;School of Materials Science and Engineering,Jiangsu University of Science and Technology,Zhenjiang 212003,China;The 6th Military Representative Room of the PLA Armament Department in Beijing,Beijing 100095,China)

机构地区：[1]航天恒星科技有限公司,北京100095 [2]江苏科技大学材料科学与工程学院,江苏镇江212003 [3]火箭军装备部驻北京地区第六军事代表室,北京100095

出　　处：《电子工艺技术》2020年第6期342-345,349,共5页Electronics Process Technology

摘　　要：航天、武器装备产品中PCB焊盘镀层与元器件镀层呈多样化趋势,带来了不同镀层与Sn63Pb37焊料匹配性问题。从微观组织角度分析了常用元器件镀层、PCB焊盘镀层与Sn63Pb37焊料的焊接匹配性。结果表明:Ag镀层器件在再流焊过程中,因界面IMC Ag_3Sn的生长和基体镀层消耗较快,需严格控制焊接温度及时间,且应使用Sn-Pb-Ag焊料焊接;薄Au镀层元器件在再流焊后,界面处未形成AuSn_4化合物,"金脆"现象应在焊点时效过程中体现;Ni/Sn-Pb、Cu/Sn镀层元器件在PCB的Cu镀Sn-Pb、Cu镀Ni/Au焊盘上与Sn63Pb37匹配性良好;Sn63Pb37焊膏与无铅BGA混装焊接时,两种焊料可充分混合,形成焊点具有良好的可靠性。In aerospace and weapon equipment products,PCB pads coating and components coating are diversifi ed,which brings about the matching problems between different coatings and Sn63Pb37 solder.From the point of view of microstructure,the soldering match between the coating of common components,PCB pads and Sn63Pb37 solder is analyzed.The results show that in the reflowing process of Ag coated devices,due to the rapid growth of interface IMC and the fast consumption of substrate coating,the refl ow temperature and time should be strictly controlled,and Sn-Pb-Ag solder should be used for soldering.After refl ow soldering,no AuSn4 is formed at the interface of thin Au coated devices,and the“gold embrittlement”should be occurred in the aging process.Ni/Sn-Pb and Cu/Sn coated component match well with Sn63Pb37 on Cu pads coated Sn-Pb or Ni/Au of PCB.When Sn63Pb37 solder paste is mixed with solder lead-free BGA devices,two kinds of solder can be fully mixed to form reliable solder joints.

关 键 词：匹配性 元器件镀层 PCB焊盘镀层 可靠性 

分 类 号：TN605[电子电信—电路与系统]