Micromechanical accelerometer with plate-like semiconductor wafers

A micromechanical accelerometer in which a movably suspended mass forms the central electrode of a differential capacitor comprising, in combination:

• a) a coverplate including an upper, frame-like insulating plate disposed therebelow;
• b) a baseplate having a lower frame-like insulating plate disposed thereabove;
• c) each of said coverplate and said baseplate comprising a semiconductor wafer bonded to said associated insulating plate;
• d) an interior counterelectrode associated with each of said coverplate and said baseplate, each counterelectrode having opposed surfaces and being surrounded on all sides at the margin by the frame of the associated insulating plate acting as screening and each counterelectrode being insulated from the associated coverplate and baseplate by an oxide layer lying therebetween;
• e) a frame-like central plate disposed between said coverplate and said baseplate with said associated frame-like insulating plates;
• f) said central plate including a plate-like mass for functioning as a pendulum, said plate-like mass being articulated to a frame spar on one side and integrally connected to said frame, said plate-like mass being deflectable perpendicular to the plane of said plate and at the same time forming the movable central electrode of said differential capacitor in opposition to and alignment with said counterelectrodes whereby said accelerometer is characterized by a multilayer, plate-like layered structure of differently etched semiconductors insulated from one another by oxide layers and externally hermetically sealed by wafer bonding.