New Technologies for Silicon Accelerometers Enable Automotive Applications

This paper describes how new enabling technologies in silicon-based sensors, including silicon fusion bonding, SenStable® piezoresistor processing, and computer-aided design and manufacturing, have made it possible to develop a complete family of acceleration sensors, uniquely suited to the automotive marketplace. The targeted applications for these devices are suspension and crash-sensing. Design considerations for these accelerometers are discussed including design trade-offs and unique operating principles. The 50G self-test accelerometer described here for the first time uses new micro-actuation principles to simulate a crash at the chip level. From a production view-point, it is equally significant that both 2G and 50G self-test chips are manufactured with exactly the same wafer processing and assembly techniques on the same manufacturing equipment. The performance of these components has been shown to be superior to other silicon accelerometer technologies in the rigorous environment.