CN-116324364-B - Pressure sensor and method for manufacturing the same

Abstract

Provided is a pressure sensor wherein foreign matter is less likely to adhere to a gel material, thereby suppressing a change in the characteristics of the pressure sensor. The pressure sensor comprises housings (2, 3) having openings (31) formed therein, a pressure-sensitive element (4) provided in the housing, a gel material (5) having water repellency and sealing the pressure-sensitive element in the housing, and a plurality of coating members (6) laid on the surface of the gel material, wherein the plurality of coating members are non-adhesive and are not bonded to each other.

Inventors

• OHTA MARI

Assignees

• 株式会社村田制作所

Dates

Publication Date

20260505

Application Date

20210721

Priority Date

20200930

Claims (3)

1. 1. A pressure sensor, wherein, The pressure sensor includes: a housing having an opening formed therein; a pressure sensitive element disposed within the housing; A gel material having water repellency and sealing the pressure sensitive element in the housing, and A plurality of coating members laid on the surface of the gel material, The plurality of coating members are non-adhesive, not bonded to each other, The plurality of coating members are two or more kinds of particles having different spherical radii from each other, When the spherical radius of the nth largest particle of the plurality of coating members is Ra and the spherical radius of the (n+1) th largest particle of the plurality of coating members is Rb, the following formula is satisfied: 。
2. 2. The pressure sensor of claim 1, wherein, The plurality of coating members are particles having a spherical shape.
3. 3. The pressure sensor according to claim 1 or 2, wherein, The plurality of coating members are composed of at least one of silicone particles, silica particles, and acrylic particles.

Description

Pressure sensor and method for manufacturing the same Technical Field The present invention relates to a waterproof pressure sensor in which a pressure sensitive element is sealed, and a method for manufacturing the same. Background Conventionally, as such a pressure sensor, for example, a pressure sensor described in patent document 1 (japanese patent application laid-open No. 2017-181302) is known. The pressure sensor described in patent document 1 includes a case having an opening, a pressure detecting element provided in the case at a position facing the opening, and a gel material sealing the pressure detecting element in the case. And applying pressure to the pressure detection element by means of the gel material. The gel material has high adhesiveness so as to be closely adhered to the housing and the pressure detecting element to prevent moisture from entering the pressure detecting element. Prior art literature Patent literature Patent document 1 Japanese patent application laid-open No. 2017-181302 Disclosure of Invention Problems to be solved by the invention However, in the pressure sensor of patent document 1, since the gel material has high adhesiveness, foreign substances are easily attached to the surface thereof. The foreign matter attached to the gel material may cause a characteristic change of the pressure sensor. In addition, it is difficult to remove foreign matters adhering to the gel material. Accordingly, an object of the present invention is to provide a pressure sensor in which foreign matter is less likely to adhere to a gel material, thereby suppressing a change in characteristics of the pressure sensor. Solution for solving the problem In order to achieve the foregoing object, a pressure sensor of the present invention includes: a housing having an opening formed therein; a pressure sensitive element disposed within the housing; A gel material having water repellency and sealing the pressure sensitive element in the housing, and A plurality of coating members laid on the surface of the gel material, The plurality of coating members are non-adhesive and are not bonded to each other. ADVANTAGEOUS EFFECTS OF INVENTION According to the present invention, foreign matter is less likely to adhere to the gel material, thereby suppressing the characteristic change of the pressure sensor. Drawings Fig. 1 is a side view of a pressure sensor according to embodiment 1 of the present invention. Fig. 2 is a top view of the pressure sensor of fig. 1. Fig. 3 is a sectional view taken along line A1-A1 of fig. 2. Fig. 4 is a schematic view showing the arrangement of a plurality of cover members in relation to the pressure sensor according to embodiment 2 of the present invention. Fig. 5A is a cross-sectional view showing an example of a method of manufacturing the pressure sensor of fig. 1. Fig. 5B is a cross-sectional view showing an example of a method of manufacturing the pressure sensor of fig. 1. Fig. 5C is a cross-sectional view showing an example of a method of manufacturing the pressure sensor of fig. 1. Fig. 6 is a flowchart of a method of manufacturing the pressure sensor of embodiment 1 of the present invention. Fig. 7 is a flowchart of a1 st method of manufacturing a pressure sensor according to embodiment 2 of the present invention. Fig. 8 is a flowchart of a 2 nd method of manufacturing a pressure sensor according to embodiment 2 of the present invention. Fig. 9 is a schematic view showing the arrangement of a plurality of cover members with respect to the pressure sensor of the present invention. Detailed Description The pressure sensor according to an aspect of the present invention includes a case having an opening, a pressure-sensitive element provided in the case, a gel material having water repellency and sealing the pressure-sensitive element in the case, and a plurality of coating members laid on a surface of the gel material, wherein the plurality of coating members are non-adhesive and not bonded to each other. According to this structure, since the surface of the gel material is covered with the plurality of covering members, foreign substances are prevented from adhering to the gel material. Further, since the plurality of coating members are non-adhesive, foreign matter adhering to the coating members can be easily removed. Thus, the characteristic change of the pressure sensor can be suppressed. Further, since the plurality of coating members are not bonded to each other, a coating structure composed of the plurality of coating members and attached to the surface of the gel material at a plurality of locations is not formed. Thus, since no stress is generated with respect to deformation of the gel material, a change in the characteristics of the pressure sensor due to a change in the stress can be suppressed. Further, the foreign matter does not reach the surface of the gel material through the gap generated in the coating structure, and the change in the characterist