Comparison of ultrasonic wire bonding process between gold and copper by nonlinear structure analysis

Wire bonding is one of the most important processes which connected the chip and lead frame in microelectronics packaging. Due to the expensive price of gold, copper wire and aluminum wire gradually become the substitutes of gold wire in the process of bonding. Meanwhile, changes in the materials result in a series of problems, such as violent wear of capillary and less reliable production on account of its higher Young modulus. However, the tiny range of parameter values for stable process makes it difficult to do experiment. In order to observe the process of thermalsonic bonding and find out the influence of new material in bonding stage, a transient nonlinear dynamic finite element framework is developed in this paper. A comprehensive parametric study which includes different thickness of bond pad and material of bond wire were conducted in this research to improve the reliability of wire bonding. The comparison between copper and gold wire bonding process on the third generation LEDs is introduced. As a result, this numerical simulation framework is of great importance to the development of LEDs packaging.