Integrated Circuit Wire Bond Process Window Research

Wire bonding technology as a key process in IC packaging has been widely used in modern semiconductor industry. The main purpose is to achieve electrical connections between the chip and external circuit or the chip and the chip. Traditional bonding process is used the golden wire for the electrical connection. Since 2000, due to the rising price of gold in the international market has become an important factor affecting the cost of the integrated circuit. With the advancement of technology, the development of integrated circuit bonding new materials has entered a new stage. The copper wire technology has been get a significant market share in a short time since 2004. With the FAB cost reduction requirements and the copper material limitations, the new silver alloy bonding wire began to evaluated and started new production by some major assembly manufactory houses. Base on the superior electrical performance and good reliability, copper and silver alloy bonding wire are constantly challenging the dominance of golden bonding wire. The paper is start with golden bonding wire process, and combining the copper and silver bonding wire, performed an amount of systematic experiment from bonding equipment hardware, key parameter and bonding tools, identified the process window of different bonding materials though the scientific analysis. Assembly level reliability test was performed for the different bonding wire materials with the identified process window to validate the result. It is noteworthy that since 2010, silver bonding wire as a new material start to evaluate, but the process and material still fully defined yet. The evaluation of silver wire bonding process window is a new development beside the golden and copper bonding wire process in this article. It provides a solution of the different metal bonding wire selection and utilization in future.