Pressure sensor

Abstract

The utility model provides a pressure sensor, which can reduce stress applied to a built-in circuit substrate, realizes a structure capable of ensuring liquid tightness with high precision, and is used with high reliability. A pressure sensor (100) in which a sensor chip (11) for detecting the pressure of an object to be measured is connected to a circuit board (50) built in a housing (20), the pressure sensor being characterized in that: the sensor chip is provided in a liquid-sealed chamber (LR) so as to receive the pressure of the object to be measured; the circuit board is disposed between the sensor chip and an external device (A) in an installation space (SR) formed in a liquid-tight manner by filling a sealing material (26) in the housing, the circuit board is conductively connected to a core wire (C) of a lead wire (38) led out to the outside and connected to the external device, and the core wire is covered by a covering portion (38c) to the front of the installation space.

Description

Technical Field

[0001] The utility model relates to a pressure sensor which is molded in a liquid-tight manner by resin. Background Art

[0002] Various sensors for detecting pressure, temperature, etc. are fixed near a measurement object and are used in a manner of sending a detection signal to a measurement device or the like, and are widely used in a manner of being built in or external to the measurement device.

[0003] Such various sensors can be installed in a sensor unit and used in a location exposed to the same environment as the object to be measured. For example, when it is necessary to change the electrical characteristics of the input and output to the sensor chip, a circuit board is sometimes built in (see Patent Document 1).

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent No. 6633597 Utility Model Content

[0007] Issues to be Solved by Utility Models

[0008] However, in the pressure sensor described in Patent Document 1, Figure 8 As shown, the circuit board 1431 connected to the sensor chip 1121 in the housing 1124 is accommodated in a case 1135 , and the case 1135 is sealed liquid-tightly by filling a sealing material 1136 such as a resin material in the case 1135 .

[0009] In such a structure, there are differences in the linear expansion coefficients of constituent materials such as the circuit substrate 1431, the housing 1135, and the sealing material 1136. Therefore, when a temperature difference occurs between the inside and outside of the measurement object, stress corresponding to the temperature difference may be generated. This stress may become a load on the circuit substrate 1431 itself or a component mounted on the circuit substrate 1431.

[0010] In addition, such a pressure sensor is often used to connect a lead wire that can be electrically connected to an external device to a circuit substrate, for example, Figure 8 In the pressure sensor shown, a lead wire 1433 conductively connecting the core wire C to the circuit substrate 1431 is led out so as to be connectable to an external device.

[0011] In such a structure, the sealing material 1136 is filled to seal the housing 1135 in a liquid-tight manner. However, when the sealing material 1136 is filled in a state where the sheath 1433c of the lead 1433 is in close contact with one side of the circuit substrate 1431, it is difficult to bury the boundary end of the core wire C exposed from the lead 1433, that is, the sheath end, in the sealing material 1136 to seal it in a liquid-tight manner. In addition, since the lead wire has a structure in which thin-diameter wires are twisted, there is a tiny space inside the core wire, and the external air on the external device side is connected to the circuit substrate part of the pressure sensor through the tiny space. For example, in a pressure sensor installed in a refrigerant piping in a refrigeration cycle, the temperature change of the refrigerant in the piping accompanying the start and stop of the unit repeatedly acts. In such a case, due to the temperature difference, pressure difference, temperature expansion and contraction between the pressure sensor body and the external device side, it is possible that the so-called breathing effect occurs in which moisture in the air penetrates into the pressure sensor through the core wire. In such a case, moisture in the atmosphere penetrates into the other end surface side of the circuit substrate 1431, and there is a possibility that a short circuit or migration of the circuit substrate may occur due to condensation.

[0012] Therefore, an object of the present invention is to provide a pressure sensor which can reduce stress applied to a built-in circuit board, realize a structure that ensures liquid-tightness with high accuracy, and can be used with high reliability.

[0013] Solutions to Solve Problems

[0014] Solution 1 of the utility model of a pressure sensor for solving the above-mentioned problems is a pressure sensor, which is a sensor for detecting the pressure of a measuring object and is connected to a circuit substrate built in a shell, and is characterized in that the sensor is arranged in a pressure chamber in a manner to withstand the pressure of the measuring object, and the circuit substrate is arranged in a manner between the sensor and an external device in a setting space formed liquid-tightly by filling a sealing material in the shell, and the circuit substrate is conductively connected to a core wire of a sheathed connecting component that is led out to the outside and connected to the external device, and the core wire of the sheathed connecting component is sheathed by a sheathing portion to near the setting space.

[0015] A second aspect of the utility model is characterized in that the conductive core wire of the covered connection member passes through a space forming member forming the installation space and is conductively connected to the circuit board.

[0016] A third aspect of the utility model is characterized in that the conductive core wire of the covered connection member is conductively connected to the circuit board via an external connection member penetrating through a space forming member forming the installation space.

[0017] A fourth aspect of the utility model is characterized in that the covered connecting member is formed of an electric wire covered with a core wire composed of a stranded wire.

[0018] A fifth aspect of the utility model is characterized in that the external connection member is a component of the connector that penetrates a space forming member that forms the installation space and is connectable to the covering connection member.

[0019] Utility Model Effect

[0020] Thus, according to one embodiment of the present invention, the mounting components of the circuit substrate are located in the installation space, which can avoid contact with the sealing material, and can prevent stress loads from being applied to the mounting components of the circuit substrate in advance. In addition, the connected covered connecting component is covered by the covering portion to the vicinity of the installation space where the circuit substrate is installed, and the core wire is introduced into the installation space from the sealing material, that is, the covered end of the lead wire is present in the sealing material, so it is possible to prevent moisture from penetrating into the installation space from between the covering portion and the core wire, etc., and liquid tightness can be ensured with high precision. Therefore, it is possible to provide a pressure sensor that can be used with high reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a figure which shows the pressure sensor of 1st Embodiment of this invention, and is a longitudinal cross-sectional view which shows the schematic whole structure.

[0022] Figure 2 It is a figure which shows the pressure sensor of 2nd Embodiment of this invention, and is a longitudinal cross-sectional view which shows the schematic whole structure.

[0023] Figure 3 It is a diagram showing a first other mode of the present embodiment and is a longitudinal sectional view showing a schematic overall structure thereof.

[0024] Figure 4 It is a diagram showing a second alternative form of the present embodiment and is a longitudinal sectional view schematically showing the overall structure thereof.

[0025] Figure 5 It is a diagram showing a third other form of the present embodiment and is a longitudinal sectional view schematically showing the overall structure thereof.

[0026] Figure 6 It is a diagram showing a fourth other form of the present embodiment and is a longitudinal sectional view schematically showing the overall structure thereof.

[0027] Figure 7 It is a diagram showing a fifth other form of the present embodiment and is a longitudinal sectional view schematically showing the overall structure thereof.

[0028] Figure 8 It is a figure which shows the prior art of this embodiment, and is a longitudinal sectional view which shows the schematic whole structure.

[0029] In the figure:

[0030] 10—pressure sensor unit; 11—pressure sensor chip; 20, 220, 320, 420A, 420B, 520—waterproof housing; 24, 124, 324, 624—spacer; 25, 325—cover component; 26, 226, 626—sealing material; 30—connector component; 38—lead; 38c—covering portion; 40—pin; 44—oil filling tube; 50—circuit board; 100—pressure sensor; 126—contact pin; 524—spacer; 530—connector; 531—contact component; 625—space cover; 636—double contact component; 637—single contact component; A—external device; C—core wire; SR—setting space. DETAILED DESCRIPTION

[0031] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Figure 1 It is a figure explaining the pressure sensor which concerns on 1st Embodiment of this invention.

[0032] <First Embodiment>

[0033] exist Figure 1 In the embodiment, the pressure sensor 100 is manufactured as follows: a pressure sensor unit 10 provided with a pressure sensor chip (sensor) 11 is installed in a refrigerant piping in the unit to measure the pressure of the refrigerant in, for example, a refrigeration cycle, and the pressure information detected by the pressure sensor chip 11 is output to an external device A which is a control device for controlling the refrigeration cycle. The pressure sensor 100 of this embodiment is configured to be able to connect the pressure sensor unit 10 having a metal waterproof housing 20 formed in a cylindrical shape to a piping that guides a fluid such as a gas or liquid to be measured by, for example, using a metal joint member 30.

[0034] The waterproof housing 20 is fixed by covering one end face side of a thick cylindrical metal housing 12 that houses the pressure sensor chip 11 of the pressure sensor unit 10 and welding, etc., and is connected to the peripheral edge of a disc-shaped metal cover 28 to which a joint component 30 is fixed by welding, etc., on the other end face side of the housing 12. The joint component 30 is formed with an internal thread 30s so that it can be threadedly fixed to a pipe or the like to be a pressure measurement object, and a fluid supplied from the pipe in the direction of arrow P is introduced into a pressure chamber PR, which is a space surrounded by the cover 28, the housing 12, and a diaphragm 32 described later, through a port 30a connected to the internal thread 30s. The outer peripheral edges of the waterproof housing 20, the housing 12, and the cover 28 are welded from the outside by TIG welding, plasma welding, laser welding, etc., and are integrated with a desired bonding strength.

[0035] The housing 12 is arranged so that the pillar 13 having the pressure sensor chip 11 at one end is located at the center of the inner tube, and a sealing glass 14 is formed to fill between the inner surface of the housing 12 and the outer surface of the pillar 13 to ensure a closed state and to fix the components penetrating the interior in a liquid-tight manner.

[0036] In the pressure sensor unit 10, a metal diaphragm 32 is fixedly bonded to the lower end surface of the housing 12. The diaphragm 32 forms an airtight pressure chamber PR on the cover 28 side and isolates the installation space of the pressure sensor chip 11 on the support 13 side in the housing 12 from the pressure chamber PR.

[0037] Furthermore, in the pressure sensor unit 10, the installation space of the pressure sensor chip 11 formed by the sealing glass 14 and the diaphragm 32 in the inner cylinder of the housing 12 is filled with a predetermined amount of silicone oil (or fluorine-based inert liquid, etc.) as a pressure transmission medium to act as a liquid seal chamber LR.

[0038] Thus, the pressure sensor chip 11 functions as a pressure sensor that detects the pressure of the fluid of the detection object introduced into the pressure chamber PR from the piping connected to the joint member 30 via the diaphragm 32 as the pressure change of the pressure transmission medium in the liquid seal chamber LR. That is, the pressure chamber PR of the present embodiment is constructed as a structure having the liquid seal chamber LR, and is made into a structure capable of detecting the pressure of the fluid of the measurement object introduced from the joint member 30 by the pressure sensor chip 11. In addition, as the pressure chamber, it is also possible to not have a liquid seal chamber, and directly load the pressure of the fluid of the measurement object on the sensor chip for measurement. In addition, the measurement object is not limited to liquids, and of course it can also be a gas such as various gases, or a mist gas containing tiny fluid particles.

[0039] The pressure sensor chip 11 is configured to supply power by connecting a plurality of leads (covered connection components) 38 from an external device A to pins (pin components) 40 connected via a circuit substrate 50 described later through bonding wires 11w, and output a detection signal as pressure information. In addition, the pressure transmission medium is filled into the liquid seal chamber LR between the sealing glass 14 and the diaphragm 32 in the inner cylinder of the housing 12 through the oil filling tube 44. These pins 40 and the oil filling tube 44 are arranged in the same circle at equal intervals with the support 13 as the center, and are supported to be insulated from the housing 12 through an insulating material such as the sealing glass 14. In addition, the oil filling tube 44 closes one end after the pressure transmission medium is filled.

[0040] The diaphragm 32 is prevented from being damaged by external force or sudden pressure in the pressure chamber PR by joining and fixing a diaphragm protection cover 34 having a plurality of communication holes 34a to the lower end surface of the housing 12. In addition, a concave frame 16 is fixed to one end of the sealing glass 14 and a cover-shaped shielding plate 17 is installed. The frame 16 receives the pressure transmission medium so that it flows freely between the pressure sensor chip 11 side and the diaphragm 32 side through the communication holes 17a formed in the shielding plate 17 to suppress sudden pressure changes.

[0041] The pins 40 are arranged with two power terminals, one output signal terminal, and five adjustment terminals used during assembly, and are electrically connected to the pressure sensor chip 11 via bonding wires 11 w. These pins 40 are fixedly supported on the sealing glass 14 in a manner protruding from one end surface of the housing 12 .

[0042] One end of a resin spacer 24 formed into a short-sized roughly cylindrical shape is embedded in one end surface side of the housing 12 from the opening side of one end side of the waterproof housing 20, and one end of the spacer 24 is in contact with one end surface of the housing 12, and a cover member (space forming member) 25 is fixed in a closed manner on the other end side opening side of the spacer 24. Through this structure, a pressure sensor unit 10 is constructed with a setting space SR of a circuit substrate 50 for connecting the pins 40 and the lead wires 38. In addition, in the waterproof housing 20 of the pressure sensor unit 10, the setting space SR of the circuit substrate 50 is waterproofed and fixed by filling a sealing material 26 such as a polyurethane resin, and the circuit substrate 50 is welded to the core wire C of the pins 40 and the lead wires 38 to be positioned and supported. In addition, a part of the outer peripheral end of the circuit substrate 50 can also be fixed to the inner surface of the spacer 24 in an auxiliary manner by an adhesive or the like.

[0043] Among them, by arranging the circuit substrate 50 in the installation space SR formed by the housing 12, the spacer 24 and the cover member 25 in the waterproof housing 20, an air layer with low thermal conductivity can be formed around the circuit substrate 50, and the temperature change from the surroundings of the pressure sensor and the piping can be prevented from being rapidly transmitted to the circuit substrate 50. In addition, the circuit substrate 50 itself and the mounting components mounted on the circuit substrate 50 are arranged so as not to contact the sealing material 26, thereby preventing the mechanical stress caused by the contraction and expansion of the sealing material 26 accompanying the change in ambient temperature from acting on the connecting components, the mounting components, and especially their welding parts.

[0044] Moreover, both ends of the pin 40 penetrate both sides of the sealing glass 14 in the inner tube of the housing 12, and are conductively connected to the pressure sensor chip 11 via a bonding wire 11w at one end side serving as the liquid seal chamber LR side, and the other end side of the pin 40 corresponding to the power supply terminal and the output signal terminal penetrates through holes (not shown) at multiple locations of the circuit substrate 50 in the direction toward the cover member 25 and is conductively connected by welding or the like.

[0045] In addition, the lead wire 38 that can be connected to the external device A is further penetrated in a through hole (not shown) that penetrates at one point of the circuit substrate 50 in the direction toward the housing 12 after the core wire C penetrates the through hole 25h that penetrates the cover member 25, and is connected by welding or the like. The lead wire 38 connected to the circuit substrate 50 is embedded (molded) in the sealing material 26 in a state where the coating 38c around the core wire C is stripped off to the near side of the cover member 25 that forms the setting space SR, and the sealing material 26 is made to exist between the core wire C and the coating 38c, that is, the coating end portion that serves as the boundary area, and is reliably sealed in a liquid-tight manner. Among them, through holes are appropriately opened on the circuit substrate 50 in a manner that allows assembly operations, for example, a through hole (not shown) for the oil filling tube 44 is also opened. In addition, of course, the connection between the pin 40 and the lead wire 38 can be carried out not only by applying molten metal such as solder, but also by applying an adhesive containing a conductive material, for example. Furthermore, as described above, in addition to the conductive connection using welding or a conductive adhesive, the conductive connection may be performed by welding (for example, spot welding using a laser or the like), and the welding method does not need to be particularly limited.

[0046] Among them, the circuit substrate 50 is connected in series between the pressure sensor chip 11 and the external device A and functions as a part of the circuit structure. In this embodiment, a conversion adjustment circuit is mounted to adjust the different input and output voltages of the pressure sensor chip 11 and the external device A, for example, to make the input voltage DC12V, DC3.3V of the external device A become the input and output voltage DC5V of the operating voltage of the pressure sensor chip 11. This conversion adjustment circuit is not limited to this embodiment, and is an arbitrary conversion adjustment circuit for responding to various drive voltages and pressure detection signal signal forms such as voltage output forms of drive / output voltages different from this embodiment, or current output forms such as 2-wire / 3-wire, or digital output forms. In addition, these conversion adjustment circuits are composed of a plurality of electronic components not shown in the figure.

[0047] Thus, in the pressure sensor 100 of the present embodiment, the circuit substrate 50 connected in series and interposed between the pressure sensor chip 11 and the external device A is accommodated in the installation space SR in the waterproof housing 20 which is filled with the sealing material 26 and sealed liquid-tightly. Therefore, in the pressure sensor 100, the circuit substrate 50 located in the installation space SR formed on one end surface side of the housing 12 by the spacer 24 and the cover member 25 can prevent in advance the mechanical load caused by the sealing material 26 of the high-temperature resin melted during manufacturing and the thermal stress caused by the difference in expansion and contraction caused by the difference in the linear expansion coefficient of the constituent materials corresponding to the temperature change during use from being applied as stress load to the substrate itself and the mounting parts.

[0048] Furthermore, in the pressure sensor 100, the coating 38c of the lead wire 38 connected to the circuit substrate 50 is peeled off near the cover member 25 forming the setting space SR, and the core wire C of the lead wire 38 passes through the cover member 25 and is connected. Therefore, even if the core wire C of the lead wire 38 is a twisted wire, the end of the coating 38c can be buried in the sealing material 26 outside the setting space SR, and even if there is moisture transferred to the periphery of the core wire C, it can be prevented from entering the circuit substrate 50 side. In addition, in this embodiment, the core wire C is inserted into the through hole 25h of the cover member 25, but an adhesive can be further applied between the core wire C and the through hole 25h of the cover member 25. Since the core wire C is a twisted wire, a small gap is sometimes generated inside. Therefore, by applying an adhesive to the through hole 25h to seal and fix the small gap, a double sealing structure can be formed using the sealing material 26 and the adhesive. This can further prevent moisture in the atmosphere from being transferred through the minute space inside the core wire C of the lead wire 38 and from entering the installation space SR.

[0049] As a result, the pressure sensor 100 can ensure the liquid-tightness of the installation space SR where the circuit board 50, the pins 40, etc. exist with high accuracy, and can suppress the occurrence of short circuits and migration due to condensation and can be used with high reliability.

[0050] <Second Embodiment>

[0051] then, Figure 2 This is a diagram illustrating a pressure sensor according to a second embodiment of the present invention. Since this embodiment is substantially the same as the above-mentioned embodiment, the same reference numerals are used for the same structures and detailed description is omitted, and only the characteristic parts are described (the same also applies to other embodiments described below).

[0052] exist Figure 2In the pressure sensor 100, instead of the spacer 24 of the above-mentioned embodiment, a resin spacer 124 having a bottomed cylindrical shape is embedded from one end opening side of the waterproof shell 20, and the bottom 124b is fixed by abutting against one end surface side of the outer shell 12, and a cover part 25 is fixed to the other end opening side of the spacer 124, thereby constructing a pressure sensor unit 10 having a setting space SR of a circuit substrate 50 for connecting the pins 40 and the leads 38.

[0053] Among them, in the pressure sensor 100, a step 124a is formed on the inner surface of the middle section of the cylinder of the spacer 124. After the peripheral end of the circuit substrate 50 is placed on the step 124a of the spacer 124 for assembly, the opening on the opposite side of the housing 12 is covered with a cover part 25 and filled with sealing material 26, thereby making the installation space SR of the circuit substrate 50 a liquid-tight structure.

[0054] Moreover, in the pressure sensor 100, instead of the core wire C of the lead wire 38 of the above-mentioned embodiment, one end of a contact pin (external connection component) 126 which passes through the through hole 25h of the cover component 25 passes through the through hole of the circuit substrate 50 in the direction toward the housing 12 and is conductively connected by welding or the like, and the core wire C protruding from the covered end of the lead wire 38 is conductively connected to the other end of the contact pin 126 by welding or the like.

[0055] Therefore, the lead wire 38 that can be connected to the external device A is connected to the contact pin 126 and buried in the sealing material 26 in a state where the coating 38c around the core wire C is peeled off to the front of the cover member 25 forming the installation space SR. The core wire C and the end of the coating 38c are sealed by the sealing material 26 in a liquid-tight manner.

[0056] Thus, in the pressure sensor 100 of the present embodiment, the lead wire 38 is connected to the circuit substrate 50 via the contact pin 126 penetrating the cover member 25, and the core wire C from which the covering portion 38c of the lead wire 38 is stripped is connected to the contact pin 126 in front of the cover member 25 where the setting space SR is formed. Therefore, the pressure sensor 100 can also obtain the same effects as those of the above-mentioned embodiment, and can be used with high reliability while ensuring the liquid tightness of the setting space SR with high precision. In addition, in the present embodiment, as in the above-mentioned first embodiment, an adhesive may be applied to the insertion portion of the through hole 25h of the cover member 25 of the contact pin 126. Sometimes, a small gap for inserting the contact pin 126 is generated in the through hole 25h. Therefore, the small gap can be sealed and fixed by applying the adhesive to the through hole 25h, so that a double sealing structure can be formed by the sealing material 26 and the adhesive. This can further prevent moisture in the atmosphere from being transferred through the tiny space between the contact pin 126 and the through hole 25 h and from entering the installation space SR.

[0057] <First other method>

[0058] As a first alternative embodiment of the pressure sensor 100, Figure 3 As shown, instead of the metal waterproof housing 20 in the above embodiment, a resin waterproof housing 220 is provided, which is formed into a roughly cylindrical shape that extends not only outside the setting space SR but also from the outer peripheral surface of the housing 12 toward the joint component 30 to a position beyond the cover 28.

[0059] In the pressure sensor 100, instead of welding the waterproof shell 20 and the cover 28 to the outer shell 12 to ensure liquid tightness, a resin waterproof shell 220 is used to cover the entirety to ensure liquid tightness of the pressure sensor unit 10. In addition to the sealing material 26 filled on the outside of the cover part 25 on one end side of the waterproof shell 220, the sealing material 226 is also filled on the outside of the cover 28 on the other end side of the waterproof shell 220 to make it liquid-tight with the outer shell 12.

[0060] <Second other method>

[0061] As a second alternative embodiment of the pressure sensor 100, Figure 4 As shown, instead of the waterproof shell 220 in the above-mentioned other method, a resin waterproof shell 320 with a roughly cylindrical shape is installed. Similar to the above-mentioned first other method, sealing materials 26 and 226 are filled on the outer side of the cover part 25 and the cover 28 at one end side and the other end side of the waterproof shell 320 to ensure liquid tightness.

[0062] In the pressure sensor 100, instead of the above-mentioned spacer 124, a resin spacer 324 with a bottom is formed in the shape of a cylinder with a bottom and the opening on one end side is omitted at the position (height) of the step 124a, so that the bottom 324b is abutted against and fixed to the one end surface side of the housing 12, and a circuit substrate 50 connecting the pins 40 and the leads 38 is fixed to the opening on the one end side of the spacer 324.

[0063] Furthermore, the waterproof case 320 is formed so that a cover member 325 having a substantially same outer shape as the housing 12 can be mounted thereon, and a small-diameter region 320r with a reduced diameter is formed between a portion covering the entire outer peripheral surface of the housing 12 and a portion covering the outer peripheral end of the cover member 325. According to this structure, the waterproof case 320 restricts the housing 12 and the cover member 325 from approaching each other at both ends of the small-diameter region 320r, thereby ensuring a separation interval between them and ensuring a setting space SR for setting the circuit substrate 50. In addition, the contact pin 126 also penetrates the through hole 325h of the cover member 325 and is conductively connected to the circuit substrate 50.

[0064] In summary, the waterproof shell 320 does not use spacers 24, 124, 224, and the outer peripheral end of the shell 12 abuts against the step 320a on one end side of the small diameter area 320r, and the outer peripheral end of the cover part 325 abuts against the step 320b on the other end side and is assembled to form a setting space SR in which the circuit substrate 50 can be set.

[0065] <Third other method>

[0066] As a third alternative embodiment of the pressure sensor 100, Figure 5 As shown, instead of the waterproof case 320 in the above-mentioned other embodiment, waterproof cases 420A and 420B made of resin and composed of two parts are installed.

[0067] The waterproof housing 420A is formed in a cover shape with a cover member 325 integrally formed at the position of the step 320a of the small diameter area 320r of the waterproof housing 320, and has corresponding steps 420a, small diameter area 420r and cover-shaped portion 420c. The waterproof housing 420B has an inner diameter that accommodates the small diameter area 420r of the waterproof housing 420A, and is extended to the lead 38 side to ensure a space for filling the sealing material 26.

[0068] In short, the waterproof housing 420A and 420B do not use the spacers 24, 124, 224, and the cover member 25, and only the outer peripheral end of the housing 12 is abutted against the step 420a on one end side of the small diameter region 420r to form a setting space SR in which the circuit substrate 50 can be set, and the waterproof housing 420B is installed in the small diameter region 420r of the waterproof housing 420A. The waterproof housing 420A and 420B are configured such that the sealing material 226 is filled on the opening side of the waterproof housing 420A to seal the housing 12 and the cover 28 liquid-tightly, and the sealing material 26 is filled on the opening side of the waterproof housing 420B to bury the covered end of the lead 38 in the sealing material 26, thereby ensuring liquid tightness.

[0069] Among them, in this pressure sensor 100, similarly to the above-mentioned cover part 25, a through hole 420h is formed in the cover-shaped portion 420c of the waterproof shell 420A, through which the contact pin 126 connected to the circuit substrate 50 and conductively connected to the core wire C of the lead 38 passes. By welding and conductively connecting both the pin 40 and the contact pin 126 in the setting space SR formed in the waterproof shell 420A, the circuit substrate 50 is positioned and supported to be suspended.

[0070] <Fourth other method>

[0071] As a fourth other embodiment of the pressure sensor 100 of the above-mentioned embodiment, Figure 6As shown, in place of the cover member 25 and the like in the above-mentioned embodiment, in addition to the cylindrical spacer 324, a bottomed cylindrical resin spacer 524 is inverted and embedded in the waterproof housing 20 in the form of a cover, and a setting space SR for setting the circuit substrate 50 is formed between the end surface side of the housing 12. That is, the spacer 524 is formed so that the outer peripheral wall portion 524s functions as the spacer 24 for preventing the intrusion of the sealing material 26, and the bottom portion 524b functions as the cover-shaped portion of the cover member 25, thereby forming and ensuring the setting space SR in which the circuit substrate 50 and the like can be set.

[0072] Furthermore, on the spacer 524, a connector housing 533 is formed integrally at the bottom 524b with a contact member 531 conductively connected to the circuit substrate 50 located inside, so that the contact member 531 and the connector housing 533 constitute a male connector 530. The contact member 531 passes through a through hole 524h of the bottom 524b of the spacer 524 integral with the connector housing 533 and is conductively connected to the circuit substrate 50. On the outside of the spacer 524, as in the above-mentioned embodiment, a sealing material 26 is filled at the opening side of one end side of the waterproof housing 20 to ensure liquid tightness.

[0073] According to this structure, the pressure sensor unit 10 includes a male connector 530 , and by inserting a female connector (not shown) connected to one end of the lead 38 into the connector housing 533 , the external device A can be connected to the circuit board 50 via the contact member 531 and the lead 38 .

[0074] That is, the pressure sensor unit 10 can be formed into a structure in which the core wire C of the lead wire 38 is not located in the setting space SR of the circuit substrate 50, etc., but the covering portion 38c of the lead wire 38 is stripped outside the setting space SR and connected to the female connector side of the male connector 530. Moisture does not penetrate into the setting space SR from the lead wire 38. In addition, in this embodiment, an adhesive can also be applied to the insertion portion of the contact component 531 and the through hole 524h. Sometimes a small gap for inserting the contact component 531 is left in the through hole 524h. Therefore, by applying an adhesive to the through hole 524h to seal and fix the small gap, a double sealing structure can be formed using the sealing material 26 and the adhesive. As a result, it is possible to further prevent moisture in the atmosphere transmitted along the core wire C of the lead wire 38 from penetrating into the setting space SR.

[0075] <Fifth other method>

[0076] As a fifth alternative embodiment of the pressure sensor 100 described above, Figure 7As shown in the figure, a pressure sensor unit 10 is provided with a resin spacer 624 having a smaller diameter than the bottomed cylindrical spacer 124 in the above-mentioned embodiment and fixed to one end surface side of the housing 12, and a space cover 625 is covered and closed on the opening side of the spacer 624 to provide a setting space SR for installing the circuit substrate 50. The pressure sensor unit 10 is formed to have a larger diameter than the outer peripheral surface of the housing 12, and a sealing material 626 is filled from the outer peripheral side of the housing 12 to the space cover 625 in a substantially cylindrical waterproof case 520 that is embedded in the cover 28 on the other end surface side and extends to the vicinity of the closed end of the space cover 625 on the opposite side, thereby ensuring liquid tightness around the setting space SR.

[0077] The spacer 624 is inserted through the terminal pieces 636a and 636b of the double contact member 636 from the outer side of the side wall portion 624s between the pin 40 penetrating the bottom 624b and the circuit substrate 50 in the space SR, and the inserted portion is fixed by the terminal fixing adhesive. After that, the pressure sensor chip 11 can be connected to the circuit substrate 50 by conducting the pin 40 and the terminal piece 636a, and the circuit substrate 50 and the terminal piece 636b. In addition, similarly, the spacer 624 is inserted through the terminal piece 637a of the single contact member 637 from the outer side of the side wall portion 624s on the opposite side of the double contact member 636, and the inserted portion is fixed by the terminal fixing adhesive. Then, the circuit substrate 50 is connected to the terminal piece 637a, and the core wire C with the coating 38c peeled off is welded to the flat surface 637f located on the outer surface of the side wall 624s of the single contact part 637 so as to protrude from the coated end of the lead 38 to be connected. By fixing the double contact part 636 and the single contact part 637 to the spacer 624 with an adhesive in this way, the terminal pieces are prevented from falling off from the spacer and the insertion position is prevented from being offset. After the connection is connected, the sealing material 626 is filled inside the waterproof housing 20 to seal the connection part and the coated end of the lead 38. With this structure, in this other embodiment, the pin 40 of the pressure sensor chip 11 and the circuit substrate 50 are also connected to the lead 38 in series via the double contact part 636 and the single contact part 637.

[0078] That is, in this other embodiment, the lead wire 38 that can be connected to the external device A is connected to the single contact member 637 outside the installation space SR, and the core wire C whose covering portion 38c is stripped and the covering end portion of the lead wire 38 are buried in the sealing material 626 in a liquid-tight manner. In addition, the lead wire 38 is connected to the pin 40 in the installation space SR via the double contact member 636 that is configured to temporarily detour from the spacer 624 in the sealing material 626. As a result, the pressure sensor 100 can ensure the liquid-tightness of the installation space SR where the circuit substrate 50, the pin 40, etc. exist with high precision, and can suppress the occurrence of short circuits, migration, etc. caused by condensation and use with high reliability. In addition, sometimes, a small gap is formed in the insertion portion of the terminal pieces 636a, 636b, and 637a of the side wall portion 624s to the extent that the terminal pieces can be inserted. In this embodiment, the amount of adhesive applied to fix the double contact member 636 and the single contact member 637 may be enough to completely seal the gap of the insertion portion. Thus, the small gap can be sealed and fixed to the double contact member 636 and the single contact member 637 by applying the adhesive, so that a double sealing structure can be formed by the sealing material 626 and the adhesive. Thus, it is possible to further prevent moisture in the atmosphere from entering the interior of the installation space SR.

[0079] The scope of the present invention is not limited to the exemplary embodiments shown in the drawings, but includes all embodiments that bring about the same effects as the purpose of the present invention. Furthermore, the scope of the present invention is not limited to the combination of features of the present invention defined by each claim, but can be divided by all required combinations of all disclosed specific features.

Claims

1. A pressure sensor, wherein a sensor for detecting the pressure of a measurement object is connected to a circuit substrate built in a housing, wherein: The sensor is installed in the pressure chamber so as to withstand the pressure of the object to be measured, and the circuit board is installed in the installation space filled with a sealing material in the housing so as to be liquid-tight so as to be interposed between the sensor and the external device. The circuit board is conductively connected to a core wire of a covered connection component that is led out to the outside and connected to the external device, and the core wire of the covered connection component is covered by a covering portion to the front of the installation space.

2. The pressure sensor according to claim 1, characterized in that: The conductive core wire of the covered connection member passes through the space forming member forming the installation space and is conductively connected to the circuit board.

3. The pressure sensor according to claim 1, characterized in that: The conductive core wire of the covered connection member is conductively connected to the circuit board via an external connection member that passes through a space forming member that forms the installation space.

4. The pressure sensor according to claim 1, characterized in that: The covered connecting member is formed by covering an electric wire having a core wire composed of a stranded wire.

5. The pressure sensor according to claim 3, characterized in that: The external connection member is a component of the connector that penetrates the space forming member that forms the installation space and is connectable to the covering connection member.

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