CN215573338U

CN215573338U - Sensor with PVDF membrane

Info

Publication number: CN215573338U
Application number: CN202122134144.4U
Authority: CN
Inventors: 庄展提
Original assignee: 庄展提
Current assignee: Guangdong Daxin Electronic Technology Co ltd
Priority date: 2021-09-06
Filing date: 2021-09-06
Publication date: 2022-01-18
Anticipated expiration: 2031-09-06

Abstract

The utility model relates to a sensor with a PVDF film, which comprises the PVDF film and an amplifier, wherein the upper surface and the lower surface of the PVDF film are respectively provided with an upper metal layer and a lower metal layer, the upper metal layer and the lower metal layer are respectively provided with a plurality of through holes, and the amplifier is respectively electrically connected with the upper metal layer and the lower metal layer; the sensor with the PVDF film has the beneficial effects that: the upper surface and the lower surface of the PVDF film are respectively provided with an ultrathin upper metal layer and an ultrathin lower metal layer, and the upper metal layer and the lower metal layer are respectively provided with through holes with preset quantity and size, so that the whole sensor with the PVDF film is lighter and thinner in volume, small in mass, obviously increased in sensitivity, higher in accuracy and suitable for scenes with higher requirements on the sensitivity of the sensor.

Description

Sensor with PVDF membrane

Technical Field

The utility model relates to the technical field of piezoelectric sensors, in particular to a sensor with a PVDF film.

Background

The PVDF membrane is a new material with piezoelectric property, its main characteristic is that when the membrane body is subjected to certain vibration (acoustic vibration, mechanical vibration, distortion deformation), it can convert these vibrations into corresponding electric signals, according to this principle, can design many piezoelectric sensors taking PVDF membrane as basic material, the sensor made can be bent and distorted at any angle, make these sensors can be applied to fields such as military affairs, industry, measurement, electroacoustic technology, etc. extensively.

However, some piezoelectric sensors manufactured at present have large mass and general sensitivity, and some scenes with high requirements on the sensitivity of the sensors cannot meet the requirements of users.

SUMMERY OF THE UTILITY MODEL

In view of this, it is necessary to provide a sensor having a PVDF film, in order to solve the problems of the PVDF film, such as large mass and general sensitivity.

A sensor with a PVDF film comprises the PVDF film and an amplifier, wherein an upper metal layer and a lower metal layer are respectively arranged on the upper surface and the lower surface of the PVDF film, a plurality of through holes are respectively formed in the upper metal layer and the lower metal layer, and the amplifier is respectively electrically connected with the upper metal layer and the lower metal layer.

In one embodiment, the upper metal layer and the lower metal layer are respectively hot-pressed on the upper surface and the lower surface of the PVDF film.

In one embodiment, the upper metal layer and the lower metal layer are vacuum-evaporated on the upper surface and the lower surface of the PVDF film.

In one embodiment, the upper and lower metal layers are made of a low resistivity metal material.

In one embodiment, the amplifier comprises a MOS tube, a capacitor C1, a capacitor C2 and a resistor R1, wherein one end of the capacitor C1 and one end of the resistor R1 are respectively connected with a D pole of the MOS tube, and the capacitor C2 is connected with a capacitor C1 in parallel.

In one embodiment, the through holes of the upper metal layer and the lower metal layer are formed by laser drilling.

The sensor with the PVDF film has the beneficial effects that: the upper surface and the lower surface of the PVDF film are respectively provided with an ultrathin upper metal layer and an ultrathin lower metal layer, and the upper metal layer and the lower metal layer are respectively provided with through holes with preset quantity and size, so that the whole sensor with the PVDF film is lighter and thinner in volume, small in mass, obviously increased in sensitivity, higher in accuracy and suitable for scenes with higher requirements on the sensitivity of the sensor.

Drawings

FIG. 1 is a schematic diagram of an exploded structure of a sensor having a PVDF membrane according to an embodiment of the present invention;

FIG. 2 is a schematic view of the assembled structure of the sensor of FIG. 1 having a PVDF membrane according to one embodiment of the utility model;

FIG. 3 is a circuit diagram of an amplifier of the sensor of FIG. 1 having a PVDF membrane in accordance with one embodiment of the utility model.

As shown in the drawing, PVDF film 100, amplifier 200, upper metal layer 300, lower metal layer 400, and via 310.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

It will be understood that when an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly connected" to another element, there are no intervening elements present.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the utility model is for the purpose of describing particular embodiments only and is not intended to be limiting of the utility model. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

As shown in fig. 1 and 2, a sensor with a PVDF film includes a PVDF film 100 and an amplifier 200, wherein an upper metal layer 300 and a lower metal layer 400 are respectively disposed on upper and lower surfaces of the PVDF film 100, a plurality of through holes 310 are respectively disposed on the upper metal layer 300 and the lower metal layer 400, and the amplifier 200 is electrically connected to the upper metal layer 300 and the lower metal layer 400 respectively.

In one embodiment, the upper metal layer 300 and the lower metal layer 400 are respectively hot-pressed on the upper and lower surfaces of the PVDF film 100.

In one embodiment, the upper metal layer 300 and the lower metal layer 400 are vacuum evaporated on both the upper and lower surfaces of the PVDF film 100.

In one embodiment, the upper and

lower metal layers

300 and 400 are made of a metal material having a low resistivity.

In one embodiment, the amplifier 200 includes a MOS transistor, a capacitor C1, a capacitor C2, and a resistor R1, wherein one end of the capacitor C1 and one end of the resistor R1 are respectively connected to the D-pole of the MOS transistor, and the capacitor C2 is connected in parallel to the capacitor C1.

In one embodiment, the vias 310 of the upper metal layer 300 and the lower metal layer 400 are formed by laser drilling.

The upper and

lower metal layers

300 and 400 are made of a metal material having a low resistivity. Such as gold, silver, copper.

Example 1:

the PVDF film 100, the upper metal layer 300, and the lower metal layer 400 are disposed, the upper metal layer 300 and the lower metal layer 400 are ultra-thin copper foils, and the upper metal layer 300 and the lower metal layer 400 are respectively hot-pressed on the upper and lower surfaces of the PVDF film 100. The number and width of the through holes 310 are determined according to the requirements of the sensor, and the through holes 310 of the upper metal layer 300 and the lower metal layer 400 are symmetrically arranged. Leads are provided from the upper metal layer 300 and the lower metal layer 400, respectively, and the leads are connected to the amplifier 200.

Example 2: the PVDF film 100, the upper metal layer 300 and the lower metal layer 400 are arranged, the upper metal layer 300 and the lower metal layer 400 are evaporated on the upper surface and the lower surface of the PVDF film 100 by a vacuum evaporation method, the number and the width of the through holes 310 are determined according to the requirement of the sensor, and the through holes 310 of the upper metal layer 300 and the lower metal layer 400 are symmetrically arranged. Leads are provided from the upper metal layer 300 and the lower metal layer 400, respectively, and the leads are connected to the amplifier 200. The upper metal layer 300 and the lower metal layer 400 evaporated on the PVDF film 100 have a thickness of only several micrometers, so that the vibration mass is lighter, the sensitivity and frequency characteristics of the product are better, and the output amplitude of the electrical signal is larger.

Thus, a sensor with a PVDF film has the following beneficial effects: the upper and lower surfaces of the PVDF film 100 are respectively provided with the ultrathin upper metal layer 300 and the ultrathin lower metal layer 400, and the through holes 310 with the preset number and size are respectively arranged on the upper metal layer 300 and the lower metal layer 400, so that the whole sensor with the PVDF film is lighter and thinner in volume, small in mass, obviously increased in sensitivity, higher in accuracy and suitable for scenes with higher requirements on the sensitivity of the sensor.

Sensitivity: the sensitivity (the efficiency of electrokinetic conversion) of the traditional piezoelectric sheet vibration sensor is only-75 dB at most, but the sensitivity of the piezoelectric sheet vibration sensor can reach-55 dB, and is improved by nearly 20 dB. Frequency range: the frequency range of the traditional piezoelectric sheet vibration sensor is narrow, the traditional piezoelectric sheet vibration sensor is mainly focused on a high-frequency end, 1500 Hz-40 kHz is adopted, and the frequency band response width is increased to 0-500 MHz. Acoustic impedance is close to that of human tissue and water, so it can be used as a sensor for medical diagnostic tests.

As shown in fig. 3, further, since the output impedance of the PVDF film is very high, and the output impedance is a high-impedance signal, which is difficult to match with the existing sensing instrument, the JFET amplification and impedance conversion circuit is adopted in the present application, so as to amplify the weak uV level signal output by the PVDF sensor to mV level; the high impedance signal (greater than 100M omega) is converted into a low impedance (600-1200 omega) signal, so that the high impedance signal can be matched with almost all the sensing amplifiers and IC circuits. The vibration signal obtained by the PVDF sensor is transmitted to a grid G of the MOS tube, amplified by a JFET and subjected to impedance conversion, and then output from a drain D of the MOS tube, and the output signal passes through an n-shaped filter consisting of a capacitor C1, a resistor R1 and a capacitor C2 to filter an interference signal and is transmitted to the input end of the whole circuit through OUT. The source electrode of the MOS tube is a common loop end.

Furthermore, since the volume requirement of some vibration sensors is smaller and smaller (2 × 1 mm), the processing precision of the upper and lower electrodes is also very high, and the through holes 310 of the upper metal layer 300 and the lower metal layer 400 are formed by laser drilling, so as to reduce the vibration mass of the sensor and improve the vibration sensitivity thereof.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the utility model. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. The sensor with the PVDF film is characterized by comprising the PVDF film and an amplifier, wherein an upper metal layer and a lower metal layer are respectively arranged on the upper surface and the lower surface of the PVDF film, a plurality of through holes are respectively formed in the upper metal layer and the lower metal layer, and the amplifier is electrically connected with the upper metal layer and the lower metal layer respectively.

2. The sensor of claim 1, wherein the upper and lower metal layers are hot-pressed against the upper and lower surfaces of the PVDF film, respectively.

3. The sensor of claim 1, wherein the upper and lower metal layers are vacuum evaporated on both the upper and lower surfaces of the PVDF film.

4. The sensor with PVDF film of claim 1, wherein the upper and lower metal layers are made of a low resistivity metal material.

5. The sensor with the PVDF film as claimed in claim 1, wherein the amplifier comprises a MOS tube, a capacitor C1, a capacitor C2 and a resistor R1, one end of the capacitor C1 and one end of the resistor R1 are respectively connected with the D pole of the MOS tube, and the capacitor C2 is connected with the capacitor C1 in parallel.

6. The sensor with PVDF film of claim 1, wherein the vias of the upper and lower metal layers are formed by laser drilling.