SYMMETRICAL MEMS ACCELEROMETER AND ITS FABRICATION PROCESS

摘要

A symmetrical MEMS accelerometer. The accelerometer includes a top half and a bottom half bonded together to form the frame and the mass located within the frame. The frame and the mass are connected through resilient beams. A plurality of hollowed parts and the first connecting parts are formed on the top and bottom side of the mass, respectively. The second connecting parts are formed on the top and bottom side of the frame, respectively. The resilient beams connect the first connecting part with the second connecting part. Several groups of comb structures are formed on top of the hollowed parts. Each comb structure includes a plurality of moveable teeth and fixed teeth. The moveable teeth extend from the first connecting part and the fixed teeth extend from the second connecting part. Capacitance is formed between the movable teeth and the fixed teeth. Since the accelerometer is symmetrical with a large mass, it has a large capacitance with a low damping force.

主权项

1. A symmetrical MEMS accelerometer, comprising:
a top half part; a bottom half part bonded to the top half part to form a frame and a mass disposed within the frame; a plurality of resilient beams connecting the frame and mass; a plurality of hollowed parts formed on a top side and a bottom side of the mass; first connecting parts formed on the top side and the bottom side of the mass; second connecting parts formed on a top side and a bottom side of the frame and connected to the first connecting parts by resilient beams; and a plurality of comb structures formed on top of the hollowed parts, each comb structure having a plurality of moveable teeth and a plurality of fixed teeth, the moveable teeth extending from the first connecting parts and the fixed teeth extending from the second connecting parts, wherein a capacitance is formed between the movable teeth and the fixed teeth.