Flexible pressure sensor and manufacturing method thereof

Abstract

The invention discloses a flexible pressure sensor and a manufacturing method thereof, and the sensor comprises an upper resistive film layer which is a first flexible insulating film layer; the lower electrode film layer comprises two groups of fork-shaped electrodes and is arranged on a second flexible insulating film layer; the upper surface of the middle spacing layer is connected with the upper resistive film layer, and the lower surface of the middle spacing layer is connected with the lower electrode film layer, so that the whole structure of the flexible pressure sensor forms a sandwich type structure. The flexible pressure sensor is thin in thickness, large in pressure range, good in linearity and suitable for round tube or curved surface flexible installation and the manufacturing method of the flexible pressure sensor.

Description

technical field [0001] The invention relates to the technical field of pressure sensors, in particular to a flexible pressure sensor with thin thickness, large pressure range, good linearity, and suitable for flexible installation on round pipes or curved surfaces and a manufacturing method thereof. Background technique [0002] Pressure sensors are widely used in home appliances, industry, auto parts, Internet of Things and other fields. The working principle of the pressure sensor is basically to convert the change of pressure into the change of resistance value, capacitance value or voltage value. And transmitted to the control unit through the lead terminal. Among the various types of pressure sensors at present, there are probably the following technical solutions: [0003] Technical solution 1: Piezoresistive ceramic pressure sensor [0004] The technical solution is to set four thick film resistors with high gauge factor (Gauge Factor) on the surface of the ceramic...

AI Technical Summary

Problems solved by technology

This structure will cause the pressure-sensitive ceramic sheet of the ceramic shell to be easily broken when it is subjected to overload pressure, resulting in the leakage of the measured liquid or gas; the pressure-capacitance ceramic pressure sensor uses glass beads as the upper and lower ceramics in structure The isolation layer of the electrode plate, but the processing accuracy of the glass beads, the size accuracy range of the glass beads is generally in the inch 17+ / -0.2um, and even individual accuracy errors will be larger, seriously affecting the consistency of the initial capacitance of the product

On the other hand, the processing technology of using glass beads as the isolation layer of the upper and lower ceramic electrode plates is complicated, resulting in low yield of this type of ceramic capacitive pressure sensor and high product cost; although the MEMS pressure sensor of the technical scheme three has The advantages of small product size, advanced preparation technology and high measurement accuracy

But the shortcomings are also quite obvious. Due to the limitation of thin film technology and MEMS micromachining technology, the pressure range of this type of pressure sensor is relatively small at present, and the product application range is narrow; The contact friction between the brush and the conductor, the conductor or the brush is easy to wear and tear, so the working life of this type of sensor is not long;

[0015] In addition, in the above four types of technical solutions, the substrates are rigid ceramic shells, silicon crystals or glass fiber PCB boards, and the thickness of the substrates is usually relatively large, which is not suitable for installation and use in applications such as pipelines or curved surfaces.

[0016] Aiming at the technical defects and application limitations of the pressure sensors of the four types of technical solutions currently on the market

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