微观组织的影响
(哈尔滨工业大学 现代焊接生产技术国家重点实验室，
哈尔滨 150001)
摘 要: 研究了塑料球栅阵列(PBGA)钎料球激光重熔以及红外二次重熔过程中63Sn37Pb共晶钎料与Au/Ni/Cu焊盘之间界面反应。结果表明：钎料凸点/焊盘界面处金属间化合物的形貌和数量与激光输入能量密切相关。随着激光输入能量的增大，Au完全溶解到钎料中，界面处连续分布的Au-Sn化合物层全部转变为针状AuSn4相，部分针状AuSn4从界面处折断并落入钎料中，最后变为细小的颗粒状弥散分布在钎料内部。 红外二次重熔后焊点界面处的针状AuSn4溶解到钎料中，钎料组织由原来的粒状结晶结构变为层片状结晶结构，焊点界面处出现了不同形态的粗大富Pb相。
关键字: 钎料球；激光重熔；钎料凸点；红外重熔；焊点
secondary reflow on microstructure
of 63Sn37Pb/pad interface
（State Key Laboratory of Advanced Welding Production Technology,
Harbin Institute of Technology, Harbin 150001, China）
Abstract:Laser and infrared secondary reflow have obvious effects on the interfacial microstructure of 63Sn37Pb eutectic solder and Au/Ni/Cu pad. The results s how that the morphology of intermetallic compounds at interface is strongly influenced by laser input energy. With increase of laser input energy, Au dissolves in to the molten solder completely, and continuous Au-Sn intermetallics changes into needle-like AuSn4 phase. The needle-like AuSn4 is broken off from the interface and falls into the solder, and disappears from the interface finally. After secondary infrared reflow, needle-like AuSn4 dissolves into the solder as rod-shape. Microstructure of solder bulk changes from grain shape into lamella shape, and different shapes of Pb-rich islands appear at the interface.
Key words: solder ball; laser reflow; solder bump; infrared reflow; solder joint
