Acceleration threshold switches from an additive electroplating MEMS process

An acceleration threshold sensor fabricated with an electroplating technolo gy on top of a CMOS signal processing circuit is presented in this paper. M anufacturing of the device is achieved using a standard low-cost CMOS produ ction line and employing a specialized back-end process tar adding the mech anical sensor-elements. This production technology makes the system especia lly interesting for automotive applications in airbag systems or transporta tion shock monitoring systems. These applications demand smaller size, impr oved functionality. high reliability and low costs. factors that can be sat isfied with this neu technology. The initial additive electroplating techno logy (AET) has been improved by coating the basis structures with an electr oplated alloy. Additionally, a specialized packaging procedure has been dev eloped to hermetically seal the sensor-structures following their release a fter the sacrificial layer removal. The devices are finally SMD-packaged to allow for easy handling. Samples of the device have been tested extensivel y and have successfully proven its functionality. (C) 2000 Elsevier Science S.A. All lights reserved.