Simulation Study on Failure Factors of Pressure Sensor´s Bond Wire

With the development of automobile technology, more and more sensors are used for control of brakes, suspensions, engines, etc. To work well under harsh condition such as high temperature, power cycling, and rapid vibration, a sensor must have high reliability and durability, which is a great challenge to original equipment manufacturers (OEMs) and suppliers. It has been found that some bond aluminum-silicon wires in some pressure sensors were broken after vibration test with the 20g acceleration. Many factors have an effect on the sensor´s reliability, for example, solder-lead materials, sensor structure and so on, however, wire bonding process was a key issue in sensors´ IC package. In this paper, the authors take into account various parameters of bond wire such as the diameter and height of bond-wire, the span of the bond wire between two bond pads, and the thickness of squashed bond pad. A simplified model is established by reasonably simplifying some components´ geometry property and boundary conditions. The simulation results show that sensor´s reliability is high enough when suitable parameters of bond wire are selected, which provide a feasible method to improve the robustness of the process