Beam film combined sensor structure

Abstract

The invention provides a beam film combined sensor structure which comprises a support beam at a bottom. An upper part of the support beam is a pressure-sensitive resistance layer. A surface layer of the pressure-sensitive resistance layer is a passive film. A cross section of the support beam is an upright right angle trapezoid. The upper part of the support beam is provided with a protection strip which has an equal height with the pressure-sensitive resistance layer and the passive film. The protection strip is used for restricting lateral movement of the pressure-sensitive resistance layer and the passive film at the surface of the pressure-sensitive resistance layer, and protecting a side surface of the pressure-sensitive resistance layer. The cross section of the support beam is an upright right angle trapezoid, i.e., a wide edge of the right angle trapezoid is at a lower part, a narrow edge of the right angle trapezoid is at an upper part, thus pressure received by the upper part narrow edge is dispersed in a sector form, and a stress requirement of supporting a shell by the bottom is reduced.

Description

technical field [0001] The invention relates to a pressure sensor structure, specifically a sensor structure in which a passivation film and a support beam are combined. Background technique [0002] The most important part of the MEMS pressure sensor is the piezoresistor that senses the pressure. The commonly used structural formula uses four piezoresistors to form a Wheatstone bridge. Therefore, the commonly used pressure sensor structure will involve a piezoresistive layer. In the process of use, due to the need to protect the varistor layer, and at the same time need to withstand the pressure after feeling the pressure, a support beam is required. The commonly used support beams are inverted trapezoidal structures, which are carried out by the narrow side of the trapezoid. Support the pressure felt, and the wide side does not need to bear the pressure. In order to ensure sufficient support strength, it is necessary to design the narrow side of the trapezoid to be wide e...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to provide a beam-membrane combined sensor structure to solve the problem that the integrated support beam adopted in the prior art is an inverted trapezoid, its stress bearing range is relatively small, the stress distribution is uneven, and the problem of stress concentration is easy to occur

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