引线键合的界面特性

利用扫描电镜和EDS能谱分析研究了Al-Al,Au-Al和Au-Ag超声键合横界面和纵切面的微观结构特性及其变化,分析了键合界面结构随超声功率和作用时间变化的规律.研究结果表明:超声键合界面的形状特性像一个中央未结合的椭圆,皱脊周边产生键合,其键合强度取决于激烈起皱的周边和未结合的中央面;当作用力和功率固定时,随着时间的增加,键合区向中央延伸;当作用力和作用时间固定时,随功率的增加,焊接区里皱脊面扩大;Au-Ag扩散偶的Kirkendall扩散效应及Au-Al键合界面可能形成金属间化合物.

Characteristics of Wire Bonded Interface

Lift-off and longitudinal section characteristics on ultrasonic bonded micro-interface including AlAl, AuAl and AuAg were observed by means of scanning electron microscope and energy dispersive spectrum. Microstructures of the bond interface were evolved by the ultrasonic variables, i.e., power and time. The results show that the peeling underdeveloped bonds simulate a torus (or doughnut) with an unbonded central region and ridged peripheral region. Bond strength is located between the severely ridged periphery and the non-adhering central area of the bond. For constant force and time, the ridged area of the bond pattern is increased in size with increasing power. For constant force and power, the ridged location of the bonded region moves closer to the bond center with increasing time. Kirkendall effect in AuAg interface and intermetallic compounds in AuAl interface are confirmed.