To provide a semiconductor acceleration sensor in which an insulating film for inhibiting contact of a movable electrode with a fixed electrode is kept from dielectric breakdown due to discharge caused in anode joining.
A silicon substrate 2 having an overlap part 6 displaced by acceleration is anode joined to the upper surface of a glass substrate 1 having a fixed electrode 8 to be integrated. The overlap part and the fixed electrode are opposite to each other, and the opposite surface of the overlap part is taken as a movable electrode 7. On the surface of the glass substrate, an insulating layer 11 is provided through an electrode material 10 in a fixed electrode unformed area 8a in a position opposite to the movable electrode 7. Thus, when the overlap part is largely displaced, the movable electrode 7 and the insulating layer 11 first come into contact with each other so that both electrodes are kept from electric contact. Further, since the fixed electrode 8 and the insulating layer 11 are out of contact, in anode joining, discharge is caused between both electrodes, and at that time, high voltage is applied to the insulating layer 11 not to cause dielectric breakdown.
HARUYAMA TAKAYUKI
OBA MASATOSHI
