中文摘要：

研究了150℃等温时效过程中无Pb焊料Sn3．0Ag0．5Cu与Cu基体间金属间化合物（intermetallic compound，IMC）的生长速率及形貌演化，以及IMC的生长演化对焊锡接点力学性能的影响．结果表明，IMC厚度与等温时效时间的平方根呈线性增长关系，随着等温时效时间的增加，IMC与焊料界面由初始的凹凸不平的扇贝状形貌逐渐变得平坦．IMC厚度和界面粗糙度共同影响焊锡接点的拉伸强度和断裂模式，随着时效时间的增加，IMC变厚，同时焊料与IMC界面变平坦，断裂模式由焊料内部的韧性断裂逐渐转变为IMC层内部的脆性断裂．

英文摘要：

Thickness and roughness evolution of the intermetallic compounds （IMC） layer between Sn3.0Ag0.5Cu and Cu substrate are examined under various isothermal aging times at 150℃. The effect of the microstructure evolution of the IMC on the mechanical behavior of solder joints is experimentally investigated. The results show that the growth of the IMC follows the Fick＇s law that predicts the total mean thickness increases linearly with the square root of the aging time. With the increase of the isothermal aging time, the initial scallop morphology of the solder/IMC interface changes to a more planar type. Both the thickness and roughness of the IMC layer affect the tensile strength and fracture mode of the solder joints. The tensile strength decreases with the increase of either the IMC thickness or the solder/IMC interfacial roughness. With the increase of the isothermal aging time, the IMC thickness increases and the solder/IMC interfacial roughness decreases, and the fracture mode migrates from ductile fracture in bulk solder to brittle fracture in the IMC layer.