Wirebond Stability Resolution on Automotive MEMS Device Through Tape Adhesion Thickness and Plasma Characterization

There are many factors affecting the stability of the wire depending on the nature of the process and the current methodology. To achieve a good wirebond cycle, stability on the bond site is to be considered. This paper presents an integration of wirebond process with the optical device’s preparation which is currently used in the assembly operations, wherein stiffener tape lamination is part of the material preparation. The objective of stiffener lamination is to place a lamination tape on the stiffener. The exposed lamination tape will hold the material on the succeeding process as its base. During the introduction of microelectromechanical systems (MEMS) package which has a base chip carrier, only the bottom pads plated in gold with ~10 µm height are seated on the lamination tape as shown in Fig. 1. Primary process such as attach process did not encountered problem since the applied force is on the downward motion, however in the process of thermocompression bonding, the pulling force of die on the upward movement to form the loop causes bouncing effect and movement of ceramic. Since it was the first time that the current operations to run the MEMS technology, many observations were considered.The non-stick on pad (NSOP) that happened in this paper were a combination of material and process methodology used in developing the product to align with the current 4Ms applied on the line and the constraint of the time to launch the project on the operations.