Sn-30Bi-05Cu低温无铅钎料的微观组织及其力学-中国有色金属学报.PDF

19 10 2009 10 Vol.19 No.10 The Chinese Journal of Nonferrous Metals Oct. 2009 1004-0609(2009)10-1782-07 Sn-30Bi-0.5Cu ( 100088) Sn-Bi Cu Sn-30Bi-0.5Cu Cu Bi /Bi Cu-Sn (Intermetallic compounds, IMC) Cu 0.5%() IMC β-Sn Sn-Bi Sn-Bi-Ag Sn-30Bi-0.5Cu Sn-Bi-Cu TG 425 A Microstructures and mechanical properties of Sn-30Bi-0.5Cu low-temperature lead-free solder ZHANG Fu-wen, XU Jun, HU Qiang, HE Hui-jun, WANG Zhi-gang (Beijing COMPO Solder Co. Ltd., General Research Institute for Non-ferrous Metals, Beijing 100088, China) Abstract: A new type of low-temperature solder, Sn-30Bi-0.5Cu was fabricated by adding Cu elements into the tin-bismuth series solder. The microstructures and mechanical properties of the solder were studied. The results show that the addition of Cu elements can restrain the segregation of bismuth in the interface between solder and Cu pad, prevent the bismuth from forming into bulky crystal as strips, and in-situ form Cu-Sn intermetallic compounds(IMCs) in tin-bismuth solder. When the mass fraction of Cu is about 0.5%, both of the tensile strength and elongation reach to the best values, and the vibration reliability increases. The reason is that the addition of Cu element can improve the microstructures of the Sn-Bi-Cu solder by forming appropriate rod-like shape fine IMC crack pinning and strengthening β-Sn soft matrix, thus strengthening its soldering and vibration mechanical properties which are close to