(1. 河南科技大學(xué) 材料科學(xué)與工程學(xué)院，洛陽 471023；
2. 河南科技大學(xué) 有色金屬共性技術(shù)河南省協(xié)同創(chuàng)新中心，洛陽 471023)
摘 要: 采用SEM、EDS、XRD等對苛刻熱循環(huán)下Sn2.5Ag0.7Cu0.1RExNi/Cu釬焊界面IMC及接頭性能進行研究。結(jié)果表明：苛刻熱循環(huán)下Sn2.5Ag0.7Cu0.1RExNi/Cu釬焊界面IMC由(Cu,Ni)6Sn5和Cu3Sn相組成；隨熱循環(huán)周期的增加，釬焊接頭的界面IMC (Cu,Ni)6Sn5形態(tài)由波浪狀轉(zhuǎn)變?yōu)榫植枯^大尺寸的“筍狀”，IMC平均厚度和粗糙度增大，相應(yīng)接頭剪切強度降低。添加適量Ni 0.05%(質(zhì)量分?jǐn)?shù))的釬焊接頭界面IMC平均厚度和粗糙度最低，接頭剪切強度最高。在100熱循環(huán)周期內(nèi)，隨熱循環(huán)周期增加，Sn2.5Ag0.7Cu0.1RE0.05Ni/Cu釬焊接頭剪切斷口由呈現(xiàn)釬縫處的韌性斷裂向由釬縫和IMC層組成以韌性為主的韌-脆混合斷裂轉(zhuǎn)變。
關(guān)鍵字: 無鉛釬料；苛刻熱循環(huán)；接頭；金屬間化合物；性能
（1. College of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471023, China;
2. Collaborative Innovation Center of Nonferrous Metals, Henan University of Science and Technology, Luoyang 471023, China）
Abstract:The effect of severe thermal cycling on the IMC and mechanical property of Sn2.5Ag0.7Cu0.1RExNi/Cu solder joint was analyzed by SEM, XRD and EDS. The results show that the Sn2.5Ag0.7Cu0.1RExNi/Cu solder joints under severe thermal cycling exhibit duplex intermetallic compounds (IMCs) structure; i.e., a layer of (Cu, Ni)6Sn5 close to the solder and a layer of Cu3Sn adjacent to the Cu substrate. The morphology of the IMC in soldered joints transfers from wavy-shape into larger bamboo shoots with the increasing of thermal cycling, which causes increase of roughness and thickness, as well as decrease of the shear strength. When the Ni adding content of solder alloy is 0.05% (mass fraction), the roughness and average thickness of IMC are the lowest, the shear strength is the highest. Within 100 thermal cycling, the fracture mechanism of the joints exhibits from plastic fracture occured in the solder seam of Sn2.5Ag0.7Cu0.1RE0.05Ni/Cu to ductile-brittle mixed fracture of plastic fracture oriented in the interfacial of IMC and solder seam.
Key words: lead-free solder alloy; severe thermal cycling; solder joints; intermetallic compound(IMC); property
