Capacitive pressure sensor and manufacturing method thereof

Abstract

The invention discloses a high-linear MEMS (Micro-Electromechanical Systems) pressure sensor, comprising a bottom plate with a ball-coronary pit, and a flat-shaped top plate; the bottom plate comprises a silicon substrate, a first conductive layer and a first insulating layer from bottom to top; the top plate comprises a second insulating layer, a second conductive layer and a third insulating layer from bottom to top; and a sealed ball-coronary chamber is formed between the first insulating layer and the second insulating layer. The manufacturing method comprises a manufacturing process for the bottom plate, a manufacturing process for the top plate, and a bonding process for the top plate and the bottom plate. In the sensor, the new ball-coronary chamber is utilized as the bottom plate and three layers of composite films serve as the bendable and deformable top plate; under the action of the outside pressure, the top plate starts contacting with a ball crown from the edge of the ball crown, so that the sensor is capable of working in a linear zone at the initial stage. The linearity of the sensor can be improved greatly and a new pressure sensor solution can be provided to pressure detection of various industrial and consumer electronics fields such as tire pressure monitoring.

Description

technical field [0001] The invention relates to a capacitive pressure sensor and a preparation method thereof, in particular to a highly linear MEMS capacitive pressure sensor and a preparation method thereof. Background technique [0002] Micro-Electro-Mechanical Systems (MEMS) technology appeared in the late 1980s and was developed based on integrated circuit technology. Sensors, actuators, signal conversion and processing circuits and other devices and functional units are integrated on micron-scale chips, which contributes to the miniaturization and low-cost of the system. Power consumption, low cost, intelligence and high-precision batch integrated manufacturing provide a reliable way to realize it. MEMS pressure sensor is a kind of MEMS sensor developed earlier, and it is an outstanding representative of the commercialized sensor of MEMS. [0003] MEMS pressure sensors are divided by their structure and working principle, represented by piezoresistive and capacitive...

AI Technical Summary

Problems solved by technology

However, in the existing contact pressure sensor, in the process of contacting the upper and lower poles, there are still some non-contact areas, so the nonlinear capacitance still exists.

Images