Testing process quality of wire bonding with multiple gold wires from viewpoint of producers

Wire bonding involves welding multiple gold wires to connect integrated circuits (ICs) to external circuits for power and signal transmission. Poor-quality wire bonding can prevent the IC and the electronic product from functioning effectively. In view of this, we developed a model to assess and control the quality of wire bonding with multiple gold wires from the viewpoints of both process and producers. We first analysed the consistency of wire bonding process performance. The Six Sigma quality index was then used to directly assess the quality of the wire bonding process and thereby examine its relationship with process yield. Furthermore, we derived the upper confidence limit of index by statistical inference, and used it to develop a testing model to ensure rigorous quality assessment. A real-world application in an IC packaging factory located in the Taichung Science Park, Taiwan, demonstrates the effectiveness of the proposed method.