Directly attached airbag sensor packaging for automobiles

In this paper, performance of a directly attached airbag sensor for automobiles is analyzed for the signal characterization. The package was designed using the acceleration MEMS sensor on the flexible circuit board to attach directly on the frame surface using adhesive. For the signal characterization, impact tests were performed for the conventional sensor packaging and the directly attached sensor. During the impact, the signals were measured and compared. Numerical analyses were also employed to analyze the differences of the impact signals. It was found that the directly attached sensor provided stronger, faster and cleaner signals than those of the conventional sensor. The numerical analyses revealed that the interferences by the housing vibration of the conventional packaging had significant effect on the sensor signal. Also, the vibration mode of the frame also had great effect on the signal generation, indicating that the design of the MEMS sensor packaging requires careful consideration on the packaging structure.