CN-116067533-B - Asymmetric thin film pressure sensor

Abstract

The invention discloses an asymmetric membrane pressure sensor, and relates to the technical field of sensors. The invention comprises a spacing layer provided with a through hole, a polyvinylidene fluoride piezoelectric film, a lower electrode plate, an upper electrode plate arranged on the wave-facing surface of the upper part of the polyvinylidene fluoride piezoelectric film, an outer insulating layer and a wiring terminal point, wherein a gap with a prismatic table annular shape is formed between the side surface of the polyvinylidene fluoride piezoelectric film higher than the spacing layer and the wave-facing inclined surface of the upper electrode plate as well as the upper surface of the spacing layer, and the spacing layer, the polyvinylidene fluoride piezoelectric film, the lower electrode plate, the upper electrode plate and the outer insulating layer are overlapped to form an asymmetric structure. The invention closely attaches the other side of the polyvinylidene fluoride piezoelectric film and the lower PI copper-clad film through the pre-pressing measure, and adopts the convex design of the polyvinylidene fluoride piezoelectric film, so that the asymmetric film pressure sensor can obtain the signal capturing rate under the loading working condition with a larger incidence angle, reduce the influence of the movement of the packaging layer and reduce the measurement error of the influence of the surface folds caused by larger wave-facing surface packaging.

Inventors

• ZHANG YONGLIANG
• ZHAO HONGYU
• ZHENG HANG
• MA HONGHAO
• HAI DECHEN
• YANG KE

Assignees

• 合肥知路科技有限公司
• 中国科学技术大学

Dates

Publication Date

20260508

Application Date

20221124

Claims (7)

1. 1. An asymmetric film pressure sensor is characterized by comprising a spacer layer (5) which is arranged in the middle and provided with a through hole (501) in the middle, a polyvinylidene fluoride piezoelectric film (4) which is arranged in the through hole (501) and matched with the through hole, a lower electrode plate (1) which is arranged on the bottom surface of the polyvinylidene fluoride piezoelectric film (4), an upper electrode plate (2) which is arranged on the wave-facing surface of the upper part of the polyvinylidene fluoride piezoelectric film (4), an outer insulating layer (3) which is arranged on the outer surfaces of the lower electrode plate (1) and the upper electrode plate (2), and a wiring terminal point (6) which is arranged on the upper electrode plate (2) and the lower electrode plate (1); The bottom surface of the polyvinylidene fluoride piezoelectric film (4) is flush with the surface of the lower electrode plate (1), a wave-facing inclined surface is formed on two sides of the bottom of the upper electrode plate (2) which are jointed with the surface of the polyvinylidene fluoride piezoelectric film (4) and are extended to be jointed with the upper surface of the spacing layer (5), the lower surface of the spacing layer (5) is jointed with the outer insulating layer (3), a gap (502) with a prismatic table ring shape is formed between the side surface of the polyvinylidene fluoride piezoelectric film (4) higher than the spacing layer (5) and the upper surface of the upper electrode plate (2) and the spacing layer (5), and the polyvinylidene fluoride piezoelectric film (4) is positioned in the center of the gap (502); the spacer layer (5), the polyvinylidene fluoride piezoelectric film (4), the lower electrode plate (1), the upper electrode plate (2) and the outer insulating layer (3) are overlapped to form an asymmetric structure.
2. 2. The asymmetric membrane pressure sensor as claimed in claim 1, wherein the upper electrode plate (2) is a flexible and bondable fiber woven substrate layer with conductive adhesive on both sides, and the fiber woven substrate layer is specifically an aluminized film woven fabric with a thickness of 0.0125mm-0.2mm.
3. 3. An asymmetric membrane pressure sensor as claimed in claim 1, characterized in that the polyvinylidene fluoride piezoelectric film (4) is circular and has a diameter of 5±0.1mm and a thickness of 0.053mm-0.06mm.
4. 4. An asymmetric membrane pressure sensor as claimed in claim 1, characterized in that the upper electrode plate (2) is a double-sided PI copper-clad film with a thickness of 0.02mm-0.2mm.
5. 5. An asymmetric membrane pressure sensor as claimed in claim 1, characterized in that the spacer layer (5) is a PET film with a thickness of 0.012mm-0.05 mm.
6. 6. An asymmetric membrane pressure sensor as claimed in claim 1, characterized in that the outer insulating layer (3) is a PI film with a thickness of 0.002mm-0.25mm.
7. 7. An asymmetric membrane pressure sensor as claimed in claim 1, characterized in that the terminal points (6) are tin solder joints.

Description

Asymmetric thin film pressure sensor Technical Field The invention belongs to the technical field of sensors, and particularly relates to an asymmetric thin film pressure sensor. Background A pressure sensor is a device or apparatus that is capable of sensing a pressure signal and converting the pressure signal to a usable output electrical signal according to a certain law. The thin film pressure sensor is a thin-shaped pressure sensor, and according to the technical index of the thin film pressure sensor, the thin film is also called PVDF for polyvinylidene fluoride piezoelectric thin film, and has the advantages of (1) large piezoelectric constant, (2) high frequency response, large measuring range and (3) low acoustic impedance when the thin film is used as the pressure sensor. Compared with other sensitive elements such as tourmaline, piezoelectric quartz, piezoelectric ceramic, manganese copper and the like which can be used for measuring the pressure of the shock wave, the polyvinylidene fluoride piezoelectric film is more suitable for effectively measuring the pressure of the shock wave. The existing PVDF pressure sensor is wide in the shock wave measurement field, and adopts a copper-clad PVDF structure, and has the following problems that (1) because copper electrodes and a piezoelectric film are in free contact, the rigidity of an external insulating layer and a copper layer packaging layer of the sensor is large, the pressure amplitude of shock waves is small, the sensor needs to press a front electrode and a rear electrode with the piezoelectric film before generating stable output signals when receiving the pressure, when the sensor measures the pressure to be large or is positioned in a solid structure capable of being pre-stressed, the influence of the free contact is small, but when the measuring pressure is small, the rigidity and displacement of the packaging layer can cause larger measuring result deviation, and (2) the copper electrodes attached to the insulating film with larger thickness are coated with copper on the whole surface, the thickness and the rigidity are larger, and the surface of the packaging layer with larger rigidity is easy to cause measuring errors due to the fact that the surface of the packaging layer with the wave surface is wrinkled with larger rigidity. Therefore, aiming at the problems, the asymmetric film pressure sensor provided by the technical scheme has important significance for improving the signal capturing rate of the structural surface shock wave under the loading working conditions of different incident angles and reducing the influence of the movement of the packaging layer. Disclosure of Invention The invention provides an asymmetric membrane pressure sensor, which solves the problems. In order to solve the technical problems, the invention is realized by the following technical scheme: The invention relates to an asymmetric film pressure sensor, which comprises a spacer layer, a polyvinylidene fluoride piezoelectric film, a lower electrode plate, an upper electrode plate, an outer insulating layer and wiring terminals, wherein the spacer layer is arranged in the middle and provided with a through hole in the middle; The bottom of the upper electrode plate is flush with the surface of the polyvinylidene fluoride piezoelectric film, wave-facing inclined planes are formed on two sides of the upper electrode plate which are jointed with the surface of the polyvinylidene fluoride piezoelectric film and are jointed with the upper surface of the spacing layer after the upper electrode plate extends, the lower surface of the spacing layer is jointed with the outer insulating layer, a gap with a prismatic table ring shape is formed between the side surface of the polyvinylidene fluoride piezoelectric film higher than the spacing layer and the wave-facing inclined planes of the upper electrode plate and the upper surface of the spacing layer, and the polyvinylidene fluoride piezoelectric film is positioned in the center of the gap; The spacer layer, the polyvinylidene fluoride piezoelectric film, the lower electrode plate, the upper electrode plate and the outer insulating layer are overlapped to form an asymmetric structure. Further, the upper electrode plate adopts a flexible and bondable fiber woven substrate layer with conductive adhesive on both sides, and the fiber woven substrate layer specifically adopts aluminized film woven cloth with the thickness of 0.0125mm-0.2mm. Further, the polyvinylidene fluoride piezoelectric film is round, has a diameter of 5+/-0.1 mm and a thickness of 0.053mm-0.06mm. Further, the upper pole piece adopts a double-sided PI copper-clad film, and the thickness is 0.02mm-0.2mm. Further, the spacer layer is made of PET film, and the thickness of the spacer layer is 0.012mm-0.05 mm. Further, the outer insulating layer is a PI film, and the thickness of the outer insulating layer is 0.002mm-0.25mm. Further, the wiring terminal