JP2017134014A - Pressure sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a pressure sensor whose pressure detecting element is fixed to a supporting member with adhesive to reduce distortion of its pressure detecting element by temperature valuations and enhance its accuracy and temperature-responsiveness.SOLUTION: A pressure sensor 100 is equipped with a pressure detecting element 126 that detects the pressure of fluid, a supporting member 325 that supports the pressure detecting element 126 and adhesive that causes the pressure detecting element 126 and the supporting member 325 to adhere and be fixed to each other. A thermal stress reducing structure 325Aa, which comprises multiple convex-concave parts engaging with part of the supporting member 325, is disposed over the face of an adhesive layer 325A consisting of the adhesive.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a pressure sensor, and more particularly to a pressure sensor in which a pressure detection element is fixed to a support member with an adhesive.

  Conventionally, as a pressure sensor for detecting the pressure of a fluid, for example, liquid-sealed pressure sensors as disclosed in Patent Document 1, Patent Document 2, and the like are known.

  As will be described later, the liquid ring type pressure sensor is detected by a fluid supply unit that supplies a pressure-detected fluid to the pressure chamber, a pressure detection unit that detects the pressure of the fluid in the pressure chamber, and the pressure detection unit. A signal transmission unit that transmits a pressure signal to the outside, a fluid supply unit, a pressure detection unit, and an outer surface member that covers the signal transmission unit.

  The pressure detection unit mainly includes a housing having a through-hole, a diaphragm welded at an outer peripheral edge of the through-hole at the lower end of the housing, and isolates the above-described pressure chamber from a liquid sealing chamber described later, and a pressure chamber of the diaphragm Is formed between the diaphragm protective cover that is placed on the side and welded together with the diaphragm, the hermetic glass sealed inside the through-hole of the housing, and the recess and the diaphragm on the lower end side of the hermetic glass, and transmits pressure such as silicone oil A liquid sealing chamber filled with a medium, a column disposed in the central through hole of the hermetic glass, a pressure fixed to the column and disposed in the liquid sealing chamber, and a pressure for detecting pressure fluctuation of the silicone oil through the diaphragm Detecting element, potential adjusting member arranged around the liquid sealing chamber, and penetrating through hermetic glass, pressure detection It is connected by a child and a bonding wire, and a plurality of lead pins for inputting and outputting with respect to the pressure sensing element.

JP 2014-98685 A JP 2012-68105 A JP-A-6-204313

  In the pressure sensors described in Patent Document 1 and Patent Document 2 described above, for example, a pressure detection element such as a piezoresistive type is a column or housing formed of a metal material such as an Fe / Ni alloy or stainless steel, for example. It is fixed to the supporting member such as by an adhesive. Here, when the ambient temperature changes, thermal stress is generated due to the difference in linear expansion coefficient between the pressure detection element and the adhesive. That is, for example, when the ambient temperature decreases, the adhesive contracts compared to the pressure detection element, and when the ambient temperature increases, the adhesive expands compared to the pressure detection element. When this thermal stress occurs, there is a problem that the pressure detection element is distorted, the output characteristics of the pressure detection element are changed, and the accuracy of the sensor output is lowered.

  Patent Document 3 describes a method for evaluating the strength of an adhesive interface between a die pad and a sealing resin in a semiconductor package. Regarding a pressure sensor fixed with a pressure detection element, a support member, and an adhesive There is no description about the change in the output characteristics due to the strain of the pressure detection element.

  Accordingly, an object of the present invention is to reduce distortion of the pressure detection element due to temperature change, improve accuracy, and improve temperature response in a pressure sensor in which the pressure detection element is fixed to the support member with an adhesive. An object of the present invention is to provide a pressure sensor that can be used.

  In order to solve the above problems, a pressure sensor of the present invention includes a pressure detection element that detects the pressure of a fluid, a support member that supports the pressure detection element, and the pressure detection element and the support member that are bonded together. In the pressure sensor including the adhesive, the at least one surface of the adhesive layer composed of the adhesive is a plurality of uneven portions that engage with the support member or a part of the pressure detection element. A thermal stress reduction structure for the adhesive layer is provided.

  The thermal stress reduction structure may be a structure in which the adhesive layer enters a plurality of concave portions provided on the support member or the adhesion end face of the pressure detection element.

  In order to solve the above problems, a pressure sensor according to the present invention includes a pressure detection element that detects the pressure of a fluid, a support member that supports the pressure detection element, and the pressure detection element and the support member that are bonded and fixed. A pressure sensor including an adhesive is characterized in that a thermal stress reducing structure having a plurality of scattered adhesive portions is provided on at least one surface of an adhesive layer composed of the adhesive.

  The thermal stress reducing structure is applied to the support member or the support portion of the adhesive layer configured as a plurality of protrusions divided by grooves provided on the adhesion end surface of the pressure detection element. It may be a plurality of adhesive layer structures.

  The thermal stress reduction structure is a plurality of adhesive layer structures formed such that the adhesive layer is divided into the support member or the pressure detection element, and a space is provided between them. It may be a thing.

  Further, the thermal stress reducing structure has adhesiveness in which innumerable irregularities are formed, and is brought into contact with the pressure detecting element or the support member by being cured to be in a gel-like adhesive layer state. It is good also as what is made.

  In addition, the thermal stress reduction structure has adhesiveness, and is cured to form a gel-like adhesive layer, so that the pressure detection element or the surface roughness of the support member, or unevenness It may be a structure to be contacted.

  The pressure sensor may be a liquid ring type pressure sensor.

  The support member may be a support of Fe / Ni alloy.

  The pressure detection element may be a piezoresistive type.

  According to the pressure sensor of the present invention, in the pressure sensor in which the pressure detection element is fixed to the support member with an adhesive, distortion of the pressure detection element due to a temperature change is reduced, accuracy is improved, and temperature response is improved. Can be planned.

It is a longitudinal section showing a liquid seal type pressure sensor as an example of the pressure sensor of the present invention. It is a figure explaining generation | occurrence | production of the distortion of the pressure detection element of the conventional pressure sensor. It is a figure explaining an example of the thermal stress reduction structure of the pressure detection element of the pressure sensor of this invention. It is a figure explaining another example of the thermal stress reduction structure of the pressure detection element of the pressure sensor of this invention. It is a figure explaining another example of the thermal stress reduction structure of the pressure detection element of the pressure sensor of this invention. It is a figure explaining another example of the thermal stress reduction structure of the pressure detection element of the pressure sensor of this invention. It is a figure explaining the thermal stress reduction effect of the pressure sensor of this invention. It is a longitudinal cross-sectional view which shows another example of the pressure sensor of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a longitudinal sectional view showing a liquid ring type pressure sensor 100 as an example of the pressure sensor of the present invention.

  In FIG. 1, a liquid ring-type pressure sensor 100 includes a fluid introduction unit 110 that supplies a fluid whose pressure is detected to a pressure chamber 112A described later, a pressure detection unit 120 that detects the pressure of the fluid in the pressure chamber 112A, and a pressure A signal sending unit 130 that sends the pressure signal detected by the detecting unit 120 to the outside, a fluid introduction unit 110, a pressure detection unit 120, and an outer surface member 140 that covers the signal sending unit 130 are provided.

  The fluid introduction part 110 is connected by welding or the like to a metal joint member 111 connected to a pipe through which a fluid whose pressure is detected is guided, and an end part connected to the pipe of the joint member 111. And a metal base plate 112 having a bowl shape.

  The joint member 111 is formed with a female screw portion 111a that is screwed into the male screw portion of the pipe connecting portion described above, and a port 111b that guides the fluid introduced from the pipe to the pressure chamber 112A. The opening end of the port 111b is connected to an opening provided in the center of the base plate 112 by welding or the like. Here, the joint member 111 is provided with the female thread portion 111a. However, the joint member 111 may be provided with a male thread, or a copper connection pipe may be connected instead of the joint member 111. . The base plate 112 has a bowl shape that widens toward the side facing the joint member 111, and forms a pressure chamber 112A between the base plate 112 and a diaphragm 122 described later.

  The pressure detection unit 120 includes a housing 121 having a through hole, a diaphragm 122 that isolates the above-described pressure chamber 112A and a liquid sealing chamber 124A, which will be described later, and a diaphragm protective cover 123 disposed on the pressure chamber 112A side of the diaphragm 122. A hermetic glass 124 sealed in the through-hole of the housing 121, and a liquid sealing chamber 124A in which a pressure transmission medium such as silicone oil is filled between the diaphragm 122 and the concave portion of the hermetic glass 124 on the pressure chamber 112A side. The column 125 disposed in the central through hole of the hermetic glass 124, the pressure detecting element 126 fixed to the column 125 and disposed inside the liquid sealed chamber 124A, and the potential adjusting member disposed around the liquid sealed chamber 124A 127 and a plurality of lead pins 128 fixed to the hermetic glass 124. Includes an oil filler pipe 129 fixed to hermetic glass 124.

  The housing 121 is made of a metal material such as an Fe / Ni alloy or stainless steel. The diaphragm 122 and the diaphragm protective cover 123 are both formed of a metal material, and are both welded at the outer peripheral edge portion of the through hole on the pressure chamber 112A side of the housing 121. The diaphragm protection cover 123 is provided inside the pressure chamber 112A to protect the diaphragm 122, and a plurality of communication holes 123a through which the fluid introduced from the fluid introduction part 110 passes are provided. After the pressure detection unit 120 is assembled, the housing 121 is connected to the outer peripheral edge of the base plate 112 of the fluid introduction unit 110 by welding or the like.

  The pressure detection element 126 is bonded and fixed to the liquid seal chamber 124A side of the support 125 by an adhesive layer 125A made of an adhesive. In the present embodiment, the support column 125 is formed of an Fe / Ni alloy, but is not limited thereto, and may be formed of other metal materials such as stainless steel. The pressure detection element 126 detects the pressure of the fluid introduced from the fluid introduction unit 110 into the pressure chamber 112 </ b> A as the pressure fluctuation of the silicone oil in the liquid sealing chamber 124 </ b> A via the diaphragm 122.

  As described in Japanese Patent No. 3987386, the potential adjusting member 127 has the pressure detection element 126 placed in a no electric field (zero potential), and is affected by the potential generated between the frame ground and the secondary power source. It is provided to prevent the internal circuit from being adversely affected. The potential adjusting member 127 is disposed between the pressure detecting element 126 and the diaphragm 122 in the liquid sealing chamber 124A, is formed of a conductive material such as metal, and is connected to a terminal connected to the zero potential of the pressure detecting element 126. Connected.

  A plurality of lead pins 128 and an oil filling pipe 129 are fixed to the hermetic glass 124 by hermetic treatment in a penetrating state. In the present embodiment, a total of eight lead pins 128 are provided as the lead pins 128. That is, three lead pins 128 for external input / output (Vout), power supply (Vcc), and ground (GND) are provided, and five lead pins 128 are provided as terminals for adjusting the pressure detection element 126. . In FIG. 1, four of the eight lead pins 128 are shown. The plurality of lead pins 128 are connected to the pressure detection element 126 by, for example, a metal or aluminum bonding wire 126 a and constitute an external input / output terminal of the pressure detection element 126.

  The oil filling pipe 129 is provided to fill the inside of the liquid sealing chamber 124A with a pressure transmission medium such as silicone oil. One end of the oil filling pipe 129 is crushed and closed as shown by the dotted line in FIG. 1 after the oil filling.

  The signal sending unit 130 is provided on the side of the pressure detection unit 120 facing the pressure chamber 112A, and is fixed to the terminal block 131 with the plurality of lead pins 128 arranged thereon and the terminal block 131 with an adhesive 132a. A plurality of connection terminals 132 to be connected, a plurality of electric wires 133 electrically connected to the outer ends of the plurality of connection terminals 132 by soldering, etc., and a silicone system between the upper end of the housing 121 and the terminal block 131 And an electrostatic protection layer 134 formed of an adhesive.

  The terminal block 131 has a substantially cylindrical shape and is formed in a shape having a side wall for guiding the plurality of lead pins 128 in the vicinity of the middle stage of the cylinder, and is made of a resin material such as polybutylene terephthalate (PBT). It is formed. The terminal block 131 is fixed to the upper part of the housing 121 of the pressure detection unit 120 with an adhesive such as an epoxy resin, for example.

  The connection terminal 132 is formed of a metal material, and is fixed to the cylindrical side wall above the above-described fixing wall of the terminal block 131 by an adhesive 132a. In the present embodiment, three connection terminals 132 for external input / output (Vout), power supply (Vcc), and ground (GND) are provided. The inner end portions of the three connection terminals 132 are electrically connected to the corresponding lead pins 128 by welding or the like, but are not limited to this connection method, and may be connected by other methods.

  In the present embodiment, three electric wires 133 are provided to connect to the three connection terminals 132. The electric wires 133 are pre-soldered on the core wires 133a of the electric wires 133 which are made of polyvinyl chloride (PVC) and the like, and the stranded wires are bundled to form the connection terminals 132 by soldering or welding. However, the present invention is not limited to this connection method and may be connected by other methods. In addition, the three electric wires 133 are pulled out from the outer surface member 140 that covers the periphery of the pressure sensor 100, and then bundled into three bundles (not shown) formed of polyvinyl chloride (PVC) or the like. ).

  The electrostatic protection layer 134 is applied to the upper end surface of the housing 121 so as to cover the upper end surface of the hermetic glass 124, and an annular adhesive layer having a predetermined thickness formed of a silicone-based adhesive, and a plurality of lead pins 128 are provided. It is applied to the entire upper end surface of the protruding hermetic glass 124 and is composed of a coating layer made of a silicone-based adhesive. The electrostatic protection layer 134 is provided to improve the electrostatic strength of the pressure detection unit 120 without being affected by the presence or absence of the ESD protection circuit.

  The outer surface member 140 has a substantially cylindrical shape that covers the periphery of the pressure detection unit 120 and the signal transmission unit 130, a terminal block cap 142 that covers the top of the terminal block 131, and an inner peripheral surface of the waterproof case 141 And a sealant 143 filling between the outer peripheral surface of the housing 121 and the outer peripheral surface of the terminal block 131.

  The terminal block cap 142 is made of, for example, a resin material. In this embodiment, the terminal block cap 142 is formed so as to close the upper portion of the cylindrical terminal block 131 described above, and is covered on the upper portion of the terminal block 131 before being filled with a sealing agent 143 such as urethane resin. Is done. However, the terminal block cap 142 is not limited to this shape. The terminal block cap 142 may be formed so as to integrally close the upper portion of the terminal block 131 and the upper portion of the waterproof case 141, and may be covered after the sealing agent 143 is filled. Alternatively, a new lid member may be provided separately from the terminal block cap 142, and after the terminal block cap 142 and the sealant 143 are disposed, the new lid member may be covered on the upper portion of the waterproof case 141. Good.

  The waterproof case 141 is formed in, for example, a resin material in a substantially cylindrical shape, and a flange portion directed inward is provided at a cylindrical lower end portion. The outer peripheral part of the base plate 112 of the fluid introduction part 110 to which the signal transmission part 130 and the pressure detection part 120 inserted from the opening part of the upper part of the waterproof case 141 are connected to this flange part. By filling the sealant 143 in this state, internal components such as the pressure detection unit 120 are fixed.

  FIG. 2 is a diagram for explaining the generation of strain in the pressure detection element 126 of the conventional pressure sensor.

  In FIG. 2, for example, a piezoresistive pressure detection element 126 is a support member such as a support 125 formed of a metal material such as an Fe / Ni alloy or stainless steel, or a housing 221 shown in FIG. 8 described later. Further, it is fixed by an adhesive layer 125A composed of an adhesive. Here, when the ambient temperature changes, the curing temperature of the adhesive is high, the guaranteed temperature is in a wide temperature range, and there is no problem in the adhesive performance itself, but the linear expansion coefficient of the pressure detection element 126 and the adhesive layer 125A is not affected. Thermal stress occurs due to the difference. That is, for example, when the ambient temperature decreases, the adhesive layer 125A contracts compared to the pressure detection element 126, and when the ambient temperature increases, the adhesive layer 125A expands compared to the pressure detection element 126. To do. FIG. 2 shows the occurrence of distortion when the temperature is lowered. When the thermal stress is generated and the pressure detection element 126 is distorted as described above, the output characteristics of the pressure detection element 126 change as shown in FIG. 7 to be described later, causing a problem that the accuracy of the sensor output decreases. An embodiment of the thermal stress reducing structure of the pressure detection element of the pressure sensor of the present invention for solving the above-described problems will be described below.

  FIG. 3 is a diagram illustrating an example of a thermal stress reduction structure of the pressure detection element 126 of the pressure sensor of the present invention.

  In FIG. 3, the thermal stress reduction structure of this embodiment has a structure in which an adhesive layer 325 </ b> A composed of an adhesive enters a plurality of recesses 325 a provided on the adhesion end face of a support member such as a support 325. As a result, the shrinkage of the adhesive layer 325A that occurs when the temperature is lowered is caught by the plurality of recesses 325a, or the grooves of the adhesive layer 325A formed by the plurality of recesses 325a are separated, It is suppressed. Thereby, the distortion of the pressure detection element 126 is reduced. Here, the plurality of recesses 325 a are provided on the support member such as the support column 325, but may be provided on the pressure detection element 126.

  FIG. 4 is a diagram illustrating another example of the thermal stress reduction structure of the pressure detection element 126 of the pressure sensor of the present invention.

  In FIG. 4, the thermal stress reduction structure of this embodiment is applied to an adhesive layer support portion configured as a plurality of protrusions 425 b divided by groove portions 425 a provided on the bonding end surface of a support member such as a support column 425. A plurality of adhesive layers 425A composed of adhesives. As a result, the shrinkage of the adhesive layer 425A that occurs when the temperature decreases is directed to the center of each of the plurality of adhesive layers 425A without going to the center of the pressure detection element 126. Further, the total adhesive area is reduced by the structure of the plurality of adhesive layers 425A, and the tensile load is reduced. Thereby, the distortion of the pressure detection element 126 is reduced. Note that the number of the plurality of protrusions 425b and the shape of the groove 425a are not limited to the example of FIG. Here, the plurality of projections 425b divided by the groove 425a are provided on the support member such as the support column 425, but may be provided on the pressure detection element 126.

  FIG. 5 is a diagram for explaining another example of the thermal stress reducing structure of the pressure detecting element 126 of the pressure sensor of the present invention.

  In FIG. 5, the thermal stress reduction structure of the present embodiment has an adhesive layer composed of an adhesive, for example, masked 525 </ b> B, etc., on an adhesive end surface of a support member such as a column 525, and a space is formed between them. It has a structure of a plurality of adhesive layers 525A formed so as to be provided. As a result, the shrinkage of the adhesive layer 525A that occurs when the temperature decreases is directed to the center of each of the plurality of adhesive layers 525A without going to the center of the pressure detection element 126. Further, the total adhesive area is reduced by the structure of the plurality of adhesive layers 525A, and the tensile load is reduced. Thereby, the distortion of the pressure detection element 126 is reduced. Here, the plurality of adhesive layers 525A are formed by using the masking 525B, but the present invention is not limited to this, as long as it can be divided into a plurality of adhesive layers 525A having spaces between each other. Further, the number of the plurality of adhesive layers 525A is not limited to the example of FIG. Here, the masking 525B is attached to a support member such as the support column 525 to form the plurality of adhesive layers 525A. However, the masking 525B may be formed on the pressure detection element 126 side.

  FIG. 6 is a diagram for explaining another example of the thermal stress reducing structure of the pressure detecting element 126 of the pressure sensor of the present invention.

  In FIG. 6, the thermal stress reduction structure of this example has a sticky structure in which innumerable irregularities are formed on the bonding end surface of a support member such as a column 625, and is cured to form a gel-like adhesive layer 625 </ b> A. Thus, the pressure detection element 126 is brought into contact with the structure. The adhesive layer 625 </ b> A is configured to be a gel by curing an adhesive having tackiness. By using an adhesive that is tacky and hardens into a gel, there is no wettability, that is, there is a gap that is bonded by point contact, so that innumerable irregularities are formed on the bonding end surface of the support member. The Rukoto. In addition, the adhesive layer that has adhesiveness and is cured to be in a gel state may be bonded to the surface roughness of the support member or the unevenness of the support member with countless contacts. Moreover, you may use an adhesive sheet instead of using it, after hardening | curing the adhesive agent which does not have tackiness in a gel form. In this state, when the pressure detection element 126 is brought into contact, the pressure detection element 126 is bonded by innumerable contacts configured with innumerable irregularities. Accordingly, the shrinkage of the adhesive layer 625A that occurs when the temperature is lowered is directed to the countless contacts of the adhesive layer 625A without going to the center of the pressure detection element 126. In addition, the total adhesive area is reduced by the structure of the adhesive layer 625A having countless contacts, and the tensile load is reduced. Thereby, the distortion of the pressure detection element 126 is reduced. Here, the adhesive layer 625A is applied to a support member such as the support column 625 and then the pressure detection element 126 is contacted. However, after the adhesive layer 625A is applied to the pressure detection element 126, the support column 625 and the like are applied. It is good also as what contacts this support member.

  FIG. 7 is a diagram for explaining the thermal stress reduction effect of the pressure sensor of the present invention.

  The figure shown in FIG. 7 shows the characteristics of the overall accuracy (% FS) with respect to the temperature (° C.) on the basis of 25 ° C., comparing the non-measured product with the case of applying the thermal stress reduction structure of the present invention FIG. As shown in FIG. 7, when the thermal stress reduction structure of the present invention is applied, it is understood that the overall accuracy (% FS) with respect to the temperature (° C.) is improved as compared with the non-measured product. In the actual pressure sensor 100, the temperature characteristic adjustment is performed within a certain range, but the data of the unmeasured product shown in FIG. 7 shows the data before the temperature characteristic adjustment.

  FIG. 8 is a longitudinal sectional view showing another example 200 of the pressure sensor of the present invention.

  In FIG. 8, the pressure sensor 200 is a liquid ring type pressure sensor, like the pressure sensor 100 shown in FIG. The pressure sensor 200 shown in FIG. 8 is not provided with a through hole in the center of the housing 221 and the pressure sensor 100 shown in FIG. 1, and a recess provided on the pressure chamber 212A side of the housing 221 is made of silicone oil or the like. A liquid sealing chamber 223A filled with a pressure transmission medium is provided, and the point that the pressure detection element 224 is directly bonded and fixed to the housing 221 by an adhesive layer 221A made of an adhesive is greatly different in the liquid sealing chamber 223A.

  In FIG. 8, a liquid ring-type pressure sensor 200 includes a fluid introduction unit 210 that supplies a fluid whose pressure is detected to a pressure chamber 212A described later, a pressure detection unit 220 that detects the pressure of the fluid in the pressure chamber 212A, and a pressure A signal transmission unit 230 that transmits the pressure signal detected by the detection unit 220 to the outside, a fluid introduction unit 210, a pressure detection unit 220, and an outer surface member 240 that covers the signal transmission unit 230.

  The fluid introduction part 210 has a joint member 211 having a flow path through which a fluid whose pressure is detected is guided, and a bowl shape connected to one end of the joint member 211 by welding or the like. And a metal base plate 212 forming the chamber 212A.

  The pressure detection unit 220 is welded together with the above-described base plate 212 at the outer peripheral edge of the recess of the housing 221 and a metal housing 221 such as stainless steel having a recess on the fluid introduction unit 210 side. A diaphragm 222 that isolates the chamber 223 A, a liquid sealing chamber 223 A that is filled with a pressure transmission medium between the concave portion of the housing 221 and the diaphragm 222, and sealed by a hermetic seal 225, which will be described later, and a central portion of the housing 221 Adhesive and fixed by an adhesive layer 221A made of an adhesive, the pressure detecting element 224 that is disposed inside the liquid sealing chamber 223A and detects the pressure fluctuation of the pressure transmission medium via the diaphragm 222, and the liquid sealing chamber 223A are sealed. Hermetic seal 225 to be stopped and a part of the housing 221 are fixed and pressure An oil filling passage 226 that fills the liquid sealing chamber 223A, a ball 227 that seals one end after the pressure transmission medium is filled from the oil filling passage 226, and the above-mentioned hermetic in the housing 221. A plurality of lead pins 228 fixed by a seal 225 and connected to the pressure detection element 224 via wire bonding are provided.

  The signal transmission unit 230 is disposed on a pressure detection unit 220 inside a waterproof case 241 to be described later, and is connected to the substrate 231 to be connected to the plurality of lead pins 228 via the connector 232, and to be waterproof to be described later. And an electric wire 233 drawn from the center of the case 241.

  The outer surface member 240 is formed of a resin material in a substantially cylindrical shape, the upper end side covering the connector 232 is reduced in diameter, and the lower end side covering the pressure detection unit 220 is formed in a shape whose inner diameter is greatly enlarged. A case 241; a sealing agent 242 enclosed in a space inside the waterproof case 241 and made of an adhesive; and a sealing agent 243 enclosed in a space between the waterproof case 241 and the base plate 212 and made of an adhesive.

  Even if the pressure sensor 200 has a structure in which the pressure detection element 224 is directly fixed to the housing 221 by an adhesive layer 221A made of an adhesive, as in the pressure sensor 200 shown in FIG. 8, the pressure detection element 224, the housing The same effect can be obtained by providing the above-described distortion countermeasure structure as shown in FIGS. 3 to 6 in the 221 and the adhesive layer 221A.

  In the present embodiment, the liquid-sealed pressure sensors 100 and 200 have been described as examples. However, the present invention is not limited to this, and the adhesive layers 125A and 221A are not limited to the support 125 such as the support 125 or the housing 221. For example, the present invention can be applied to all pressure sensors having a configuration in which the pressure detection elements 126 and 224 are bonded.

  As described above, according to the pressure sensor of the present invention, in the pressure sensor in which the pressure detection element is fixed to the support member with an adhesive, the distortion of the pressure detection element due to a temperature change is reduced, and the accuracy is improved. The temperature responsiveness can be improved.

100, 200 Pressure sensor 110, 210 Fluid introduction part 111, 211 Joint member 111a Female thread part 112, 212 Base plate 112A, 212A Pressure chamber 112b Port 120, 220 Pressure detection part 121, 221 Housing 122, 222 Diaphragm 123 Diaphragm protective cover 123a Communication Hole 124 Hermetic glass 124A, 223A Liquid sealed chamber 125, 325, 425, 525, 625 Post 125A, 225A, 325A, 425A, 525A, 625A Adhesive layer 126 Pressure detecting element 126a Bonding wire 127 Potential adjusting member 128, 228 Lead pin 129 Oil filling pipes 130, 230 Signal sending part 131 Terminal block 132 Connection terminal 132a Adhesive 133, 233 Electric wire 133a Core wire 1 4 Electrostatic protective layer 140, 240 Outer surface member 141, 241 Waterproof case 142 Terminal block cap 143, 242, 243 Sealant 225 Hermetic seal 226 Oil filling passage 227 Ball 231 Substrate 232 Connector 325a Multiple recesses 425a Groove 425b Multiple Protrusion 525B Masking 625a Countless irregularities

Claims (10)

A pressure detection element for detecting the pressure of the fluid;
A support member for supporting the pressure detection element;
In the pressure sensor comprising: the pressure detection element and an adhesive that bonds and fixes the support member.
A structure for reducing thermal stress of the adhesive layer, which is a plurality of concavo-convex portions engaged with a part of the support member or the pressure detection element, on at least one surface of the adhesive layer composed of the adhesive. A pressure sensor is provided.   2. The pressure sensor according to claim 1, wherein the thermal stress reducing structure is a structure in which the adhesive layer enters a plurality of concave portions provided on an adhesion end surface of the support member or the pressure detection element. . A pressure detection element for detecting the pressure of the fluid;
A support member for supporting the pressure detection element;
In the pressure sensor comprising: the pressure detection element and an adhesive that bonds and fixes the support member.
A pressure sensor comprising: a thermal stress reducing structure having a plurality of scattered adhesive portions on at least one surface of an adhesive layer composed of the adhesive.   The thermal stress reduction structure is applied to the support member or a plurality of support portions of the adhesive layer configured as a plurality of protrusions divided by grooves provided on an adhesion end surface of the pressure detection element. The pressure sensor according to claim 3, wherein the pressure sensor has an adhesive layer structure.   The thermal stress reduction structure is a plurality of adhesive layer structures formed such that the adhesive layer is divided into the support member or the pressure detection element, and a space is provided between them. The pressure sensor according to claim 3.   The thermal stress reduction structure has adhesiveness in which innumerable irregularities are formed, and is brought into contact with the pressure detection element or the support member by being cured to be a gel-like adhesive layer. The pressure sensor according to claim 3, wherein the pressure sensor is a structure.   The thermal stress reducing structure has adhesiveness and is brought into contact with the surface roughness or unevenness of the pressure detecting element or the support member by being cured to be a gel adhesive layer. The pressure sensor according to claim 3, wherein the pressure sensor has a structure.   The pressure sensor according to claim 1, wherein the pressure sensor is a liquid ring type pressure sensor.   The pressure sensor according to claim 1, wherein the support member is a support made of an Fe / Ni alloy.   The pressure sensor according to claim 1, wherein the pressure detection element is a piezoresistive method.