Comb-shaped stereo silicon processing micro mechanical structure with fixed tooth offset

Abstract

The invention relates to design of miniature physical structure in processing spatial silicon. The invented structure consists of sensing unit, fixed teeth, and substrate. The sensing unit is composed of tooth-comb, multi group of motion teeth. The intervals from each tooth of comb in the sensing unit to adjacent two fixed teeth are not equal. The ratio of interval to two sides is 1:8-12. The invented structure provides important merits usch as less linkage blocks, large area, reducing the difficulty for block to key in, small contact resistance in place of key joint, uniformity, yield notably improved. It makes the design and process of miniature physical structure from two dimensions to three dimensions possible. Also, the invention increases resolution and precision greatly. Many lead wires and electrodes on glass plate electrode needed by the scheme of equally placed are reduced evidently. Thus one side, it prevents the interfere from distributed capacitance between lead wires and electric signal, on the other hand the amount of lead wires is decreased, work load for lead wires to key in is reduced.

Description

technical field [0001] The invention belongs to the field of micro-mechanical structure design for bulk silicon processing, in particular to the design of a comb-tooth micro-mechanical structure. Background technique [0002] The comb-tooth micro-mechanical structure is a typical structure of micro-mechanical sensors. The existing comb-tooth micro-mechanical structures are all surface-processed fixed teeth uniformly arranged structures. This structure has been successfully applied in micromachined accelerometers. Micromachined accelerometers have been newly developed internationally in the past decade. The ADXLXX series of American AD Company is the micromachined accelerometer with the highest market share. AD's micromachined accelerometer uses a comb-tooth capacitive accelerometer with uniform surface processing and fixed teeth. This force-balanced accelerometer is fabricated with a surface finish with the sensitive axis parallel to the substrate. The general structure ...

AI Technical Summary

Problems solved by technology

However, for the body-processed comb structure, due to the small bonding surface of the fixed teeth uniformly arranged structure, and the thicker and larger mass of the sensitive mass of the bulk silicon processing, the bonded fixed teeth will fall off seriously after the process flow down; in addition, through The resistance between the fixed teeth measured by the probe station is very large, which is mainly caused by insufficient bonding strength and excessive bonding contact resistance

In this way, a new problem arises, the yield rate is almost equal to zero

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