An acceleration sensor includes a semiconductor substrate, a sensing element formed on the semiconductor substrate, a bonding frame made of polysilicon which is formed on the semiconductor substrate and surrounds the sensing element, and a glass cap which is bonded to a top surface of the bonding frame...http://www.google.com.au/patents/US6953993?utm_source=gb-gplus-sharePatent US6953993 - Acceleration sensor and method of manufacturing acceleration sensor
