Pressure sensor

Abstract

The utility model provides a pressure sensor, which can reduce stress applied to a built-in circuit substrate, ensure an insulating structure and perform pressure measurement with high quality. In a pressure sensor (100), 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), and 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 provided so as to be interposed between the sensor chip and the external device (A) in an installation space (SR) formed in a liquid-tight manner by filling a sealing material (26) in the housing, the spacer further constitutes a space-forming member and an insulation-improving member for improving the resistance to insulation with the circuit board, and a mounting component (50J) of the circuit board is located in 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 Document 1: Japanese Patent No. 6633597

[0006] However, in the pressure sensor described in Patent Document 1, Fig.11 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 .

[0007] 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 and the components mounted on the circuit substrate 1431. In addition, since various electrical and electronic components are mounted on the circuit substrate 1431 of such a pressure sensor, it is necessary to ensure insulation around the circuit substrate 1431. Utility Model Content

[0008] Therefore, an object of the present invention is to provide a pressure sensor which can realize a structure that reduces stress applied to a built-in circuit board and ensures insulation, and can measure pressure with high quality.

[0009] One method of the utility model of a pressure sensor that solves the above-mentioned problem is a pressure sensor, in which a sensor for detecting the pressure of a measuring object is connected to a circuit substrate built into a housing, 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 setting space formed liquid-tightly by filling a sealing material in the housing, and has a space forming component that forms the setting space and an insulation improving component that improves the insulation resistance of the space forming component and the circuit substrate, and the mounting parts of the circuit substrate are located in the setting space.

[0010] The insulation improving member is constituted by a part of the space forming member, and a desired separation distance is set between the space forming member and the circuit board to improve insulation resistance.

[0011] The insulation improving member is formed of at least one of a plate material, a sheet material, or a coating material made of an insulating material and arranged between the space forming member and the circuit board to improve insulation resistance.

[0012] The setting space is formed by being surrounded by the space forming component which is composed of a side wall portion forming a cylindrical shape capable of accommodating the circuit substrate and a pair of closing components located at both ends of the cylindrical shape and closing the opening. The side wall portion acts as a spacer that improves the insulation resistance by providing a desired separation interval between the pair of closing components and the circuit substrate. The side wall portion and the pair of closing components constitute the space forming component and the insulation improving component.

[0013] One of the closing members is integrally formed with the side wall portion into a bottomed cylindrical shape, and the other closing member functions as a cover member of the cylindrical shape, and the side wall portion supports at least a portion of a peripheral end portion of the circuit board.

[0014] The circuit substrate is arranged in a manner between the sensor and the external device, and the sensor is conductively connected to the circuit substrate via a sensor connecting pin component that passes through the space forming component, and an external connecting component that is led out to the outside and connected to the external device is conductively connected to the circuit substrate via an external connecting pin component that passes through the space forming component.

[0015] The effects of the utility model are as follows.

[0016] Thus, according to one embodiment of the present invention, the mounting parts of the circuit substrate are located in the installation space, which can avoid contact with the sealing material and prevent stress loads from being applied to the mounting parts of the circuit substrate in advance. In addition, the insulation resistance of the circuit substrate in the installation space is improved and the mounting parts are mounted. Therefore, a pressure sensor that can be used with high reliability can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] 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.

[0018] 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.

[0019] Figure 3 It is a diagram showing a pressure sensor according to a third embodiment of the present invention, and is a longitudinal sectional view schematically showing the overall structure thereof.

[0020] Figure 4 It is a diagram showing a pressure sensor according to a fourth embodiment of the present invention, and is a longitudinal sectional view schematically showing the overall structure thereof.

[0021] Figure 5 It is a diagram showing a pressure sensor according to a fifth embodiment of the present invention, and is a longitudinal sectional view showing a schematic overall structure thereof.

[0022] Figure 6 It is a diagram showing a pressure sensor according to a sixth embodiment of the present invention, and is a longitudinal sectional view schematically showing the overall structure thereof.

[0023] Figure 7 It is a diagram showing a pressure sensor according to a seventh embodiment of the present invention, and is a longitudinal sectional view schematically showing its overall structure.

[0024] Figure 8 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.

[0025] Fig. 9 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.

[0026] Fig.10 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.

[0027] Fig.11 It is a figure which shows the prior art of this embodiment, and is a longitudinal sectional view which shows the schematic whole structure.

[0028] In the figure: 10—pressure sensor unit, 11—pressure sensor chip, 12, 712—housing, 20, 620, 720—waterproof housing, 24, 124, 324, 524, 624, 724—spacer, 25, 325, 625, 725—cover part, 26, 226, 626, 726—sealing material, 30—connector part, 38—lead, 40—pin, 50—circuit substrate, 50J—mounting part, 100—pressure sensor, 126—contact pin, 224—plate, 424, 426, 524—insulating coating material, 620t—locking part, A—external device, C—core wire, SR—setting space. DETAILED DESCRIPTION

[0029] 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.

[0030] <First Embodiment>

[0031] 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 connectable by connecting the pressure sensor unit 10 having a resin waterproof housing 20 formed in a cylindrical shape to a piping for guiding a fluid such as a gas or liquid to be measured, for example, by using a metal joint member 30.

[0032] 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 other end face side of the housing 12 by welding, etc., with the peripheral edge of a disc-shaped metal cover 28 to which a joint component 30 is fixed. The joint component 30 is formed with an internal thread 30s in a manner that allows it to be threadedly fixed to a pipe or the like of 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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 component 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 component 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.

[0037] Here, the pressure sensor chip 11 is configured to supply power to each of the plurality of leads (external connection components) 38 from the external device A by conducting connection with the pins (sensor connection pin components) 40 connected via the circuit substrate 50 described later via the bonding wires 11w, and output the detection signal as pressure information. In addition, the pressure transmission medium is filled in the liquid seal chamber LR between the sealing glass 14 and the diaphragm 32 in the inner cylinder of the housing 12 via 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 via an insulating material such as the sealing glass 14. In addition, the oil filling tube 44 is closed at one end after the pressure transmission medium is filled.

[0038] 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 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.

[0039] 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. The pins 40 are fixedly supported on the sealing glass 14 in a manner protruding from one end surface of the housing 12 .

[0040] On one end face side of the housing 12, a resin spacer 24 formed into a short-sized roughly cylindrical shape is embedded in the waterproof housing 20 from the opening side of one end side and abuts against the side wall portion of the space forming component, and at the same time, a cover component (a closing component of the space forming component) 25 is fixed in a closed manner on the opening side of the other end side, and the one end face side of the housing 12 also functions as a closing component of the space forming component. 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 leads 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 soldered to the core wire C of the pins 40 and the leads 38 to be positioned and supported.

[0041] In this structure, the circuit substrate 50 is supported in the vertical direction by the soldered leads 38 and pins 40 and is held in the interrupted hollow of the setting space SR. Therefore, when stress is generated, it is possible to avoid the stress itself being applied by slight deformation of these leads 38 and pins 40. In addition, a part of the outer peripheral end of the circuit substrate 50 may be fixed to the inner surface of the spacer 24 in an auxiliary manner by an adhesive or the like.

[0042] 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 parts 50J 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 ambient temperature change from acting on the connecting parts, the mounting parts 50J, and especially the soldered parts thereof.

[0043] Moreover, both ends of the pin 40 penetrate both sides of the sealing glass 14 in the inner tube of the outer shell 12, and are conductively connected to the pressure sensor chip 11 via the 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 part 25 and is conductively connected by soldering or the like.

[0044] In addition, the lead wire 38 that can be connected to the external device A, after the core wire C passes through the through hole 25h that passes through the cover member 25, further passes through a through hole (not shown) that passes through a place on the circuit substrate 50 in the direction toward the housing 12 and is connected by soldering or the like. Among them, through holes and the like 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, for example, an adhesive containing a conductive material. In addition, as described above, in addition to the conductive connection using soldering or a conductive adhesive, the conductive connection can also be carried out by welding (for example, spot welding using a laser or the like), and the means of welding does not need to be particularly limited.

[0045] Among them, the circuit board 50 is arranged in the installation space SR in which the housing 12, the pillar 13, the sealing glass 14, the spacer 24 and the cover member 25 constitute a space forming member in the waterproof housing 20. The circuit board 50 is liquid-tightly accommodated in the installation space SR formed by the electrically conductive pins 40, the housing 12 and the spacer 24 of a desired size that fully ensures the separation distance from the waterproof housing 20 at the same potential as the housing 12. That is, since the installation space SR is an air atmosphere, it is difficult to maintain insulation with high reliability and low cost compared with the case of embedding (molding) using the sealing material 26, but the spacer 24 fully ensures the separation distance from the housing 12 and the waterproof housing 20 and functions as an insulation improving member that improves the insulation resistance of the circuit board 50.

[0046] In addition, 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, an input-output voltage conversion adjustment circuit is mounted to adjust the different input-output voltages of the pressure sensor chip 11 and the external device A, for example, to make the input voltage DC12V or DC3.3V of the external device A become the operating voltage DC5V of the pressure sensor chip 11. Such a 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, 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 by the spacer 24 and the cover member 25 on one end surface side of the housing 12 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 component 50J.

[0048] Furthermore, in the pressure sensor 100 , the spacer 24 can sufficiently ensure the separation distance from the outer case 12 and the waterproof housing 20 in the installation space SR where the circuit board 50 is installed, thereby improving the insulation resistance of the mounted component 50J of the circuit board 50 .

[0049] As a result, the pressure sensor 100 can ensure the insulation of the circuit board 50 and perform high-quality pressure measurement.

[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, in place of the spacer 24 of the above-described embodiment, a resin spacer 124 formed in a bottomed cylindrical shape is inserted from the one end side opening side of the waterproof housing 20, and the bottom 124b is fixed in contact with the one end side of the housing 12, and the cover member 25 is fixed to the other end side opening side of the spacer 124, thereby constructing a pressure sensor unit 10 having a placement space SR for the circuit substrate 50 for connecting the pins 40 and the lead wires 38. The spacer 124 has a bottom 124b of a plate material formed in a disk shape having an inner peripheral end face 124i so that the through-portion of the pins 40 of the sealing glass 14 is open and can be in contact with the one end side of the housing 12.

[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, inside the waterproof shell 20, the spacer 124, together with the outer shell 12, the pillar 13, the sealing glass 14 and the cover part 25, also constitute a space forming part and form a setting space SR, so as to configure the circuit substrate 50, and the side wall portion 124s and the step 124a of the spacer 124 also act as an insulation improving part that fully ensures the separation distance between the circuit substrate 50 and the outer shell 12 and the waterproof shell 20 to improve the insulation resistance of the circuit substrate 50.

[0055] In this way, in the pressure sensor 100 of this embodiment, the separation distance from the outer shell 12 and the waterproof shell 20 in the installation space SR where the circuit substrate 50 is installed can be fully ensured by the spacer 124 and the insulation resistance of the installed part 50J can be improved, thereby obtaining the same effect as the above-mentioned embodiment.

[0056] <Third Embodiment>

[0057] then, Figure 3 It is a figure explaining the pressure sensor which concerns on 3rd Embodiment of this invention.

[0058] exist Figure 3In the embodiment, the pressure sensor 100 is provided with a spacer 124 and is constructed in substantially the same manner as the above-mentioned second embodiment. In the pressure sensor 100, instead of the core wire C of the lead wire 38, one end of a contact pin (external connection pin component) 126 that 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 soldering, etc., and the core wire C of the lead wire 38 is conductively connected to the other end of the contact pin 126 by soldering, etc.

[0059] Therefore, the lead 38 led out in a manner capable of being connected to the external device A is connected to the contact pin 126 and buried in the sealing material 26 when the covering portion 38c around the core wire C is peeled off to near the cover part 25 that forms the setting space SR, and the boundary area between the core wire C and the covering portion 38c, that is, the end of the covering portion 38c of the lead 38 is liquid-tightly sealed by the sealing material 26.

[0060] In this way, in the pressure sensor 100 of the present embodiment, the covering portion 38c of the lead wire 38 connected to the circuit substrate 50 is peeled off just before the cover member 25 forming the installation 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, it can be buried in the sealing material 26 outside the installation space SR between the covering portion 38c, 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.

[0061] As a result, the pressure sensor 100 can also obtain the same operational effects as those of the above-described embodiment, and can perform high-quality pressure measurement while ensuring the insulation of the circuit board 50 .

[0062] <Fourth Embodiment>

[0063] then, Figure 4 It is a figure explaining the pressure sensor which concerns on 4th Embodiment of this invention.

[0064] exist Figure 4 In addition to the spacer 24 of the above-mentioned embodiment, the pressure sensor 100 further comprises: a closing member of a plate material, namely a plate 224 (not limited to a plate material, but may also be a flexible sheet), which is formed into a disc shape having an inner peripheral end face 224i in a manner that opens the through portion of the pin 40 of the sealing glass 14 and can abut against one end face side of the housing 12.

[0065] According to this structure, in the pressure sensor 100, the plate 224 constitutes a space forming component between the circuit substrate 50 on the side opposite to the housing 12 etc. in the setting space SR, and can also function as an insulation improving component for improving the insulation resistance between the housing 12 and the circuit substrate 50, thereby ensuring the insulation of the circuit substrate 50.

[0066] Thus, in the pressure sensor 100 of this embodiment, in addition to being able to obtain the same effects as those of the above-mentioned embodiment, the insulation resistance between the pressure sensor 100 and the housing 12 etc. in the setting space SR can be improved by the plate 224, and the insulation of the mounting parts 50J of the circuit substrate 50 can be ensured with higher reliability and high quality.

[0067] <Fifth Embodiment>

[0068] then, Figure 5 It is a diagram for explaining a pressure sensor according to a fifth embodiment of the present invention.

[0069] exist Figure 5 In the embodiment, instead of the spacer 24 and the cover member 25 of the above-mentioned embodiment, the pressure sensor 100 includes a resin spacer 324 formed into a cylindrical shape with a bottom by integrally molding the spacer 24 and the cover member 25. By inverting the spacer 324 upside down, the opening side abuts against and is fixed to the side of the housing 12, thereby constituting a space forming member that forms the installation space SR of the circuit substrate 50 together with the plate 224 of the above-mentioned embodiment.

[0070] Through this structure, in the pressure sensor 100, the plate 224 and the bottom 324r of the spacer 324 are opposite to the two sides of the circuit substrate 50, and the side wall portion 324s of the spacer 324 can serve as an insulation improving component to ensure the separation interval between the plate 224 and the bottom 324r of the spacer 324 and improve the insulation resistance of the circuit substrate 50.

[0071] Thus, in the pressure sensor 100 of this embodiment, in addition to being able to obtain the same effects as the above-mentioned embodiment, the use of a bottomed cylindrical spacer 324 in which the spacer 24 and the cover member 25 are integrally formed can reduce the number of parts and the number of working hours, thereby reducing costs.

[0072] <Sixth Implementation Method>

[0073] then, Figure 6 It is a diagram for explaining a pressure sensor according to a sixth embodiment of the present invention.

[0074] exist Figure 6In the embodiment, the pressure sensor 100 includes the spacer 324 and the contact pin 126 . The contact pin 126 passes through the through hole 324 h of the bottom 324 r of the spacer 324 and is conductively connected to the core wire C of the lead 38 together with the circuit substrate 50 .

[0075] In the pressure sensor 100, the circuit substrate 50 is also soldered to the contact pin 126 and the pin 40 which are conductively connected to the core wire C of the lead 38 and is positioned and supported in the hollow portion within the setting space SR, but a portion of the outer peripheral end portion may also be fixed to the inner surface of the spacer 124 in an auxiliary manner by an adhesive or the like.

[0076] As described above, also in the pressure sensor 100 of the present embodiment, the same operational effects as those of the above-described embodiment can be obtained.

[0077] <Seventh Embodiment>

[0078] then, Figure 7 It is a figure explaining the pressure sensor which concerns on 7th Embodiment of this invention.

[0079] exist Figure 7 In the embodiment, the pressure sensor 100 does not include the plate 224 of the above embodiment, and the opening side of the side wall portion 324s of the spacer 324 is fixed to the side of the housing 12 to form a setting space SR for the circuit substrate 50, and the circuit substrate 50 is conductively connected to the core wire C of the lead 38 without using the contact pin 126 of the above embodiment.

[0080] In addition, in the pressure sensor 100, the resin material is coated in a manner to cover the pins 40 on both sides of the circuit substrate 50, the connection parts of the leads 38 with the core wire C, and the entirety including the mounting parts 50J, and the resin material is coated with an insulating coating material (insulation improvement component) 424. Furthermore, the resin material is coated in a manner to cover the entire one end surface of the housing 12 and the pillar 13 including the through-protruding parts of the pins 40 on the sealing glass 14 side, and the resin material is coated with an insulating coating material (insulation improvement component) 426.

[0081] With this structure, in the pressure sensor 100 , both sides of the circuit substrate 50 are covered with the insulating coating material 424 to ensure improved insulation, and the housing 12 side is also covered with the insulating coating material 426 to ensure improved insulation.

[0082] In this way, in the pressure sensor 100 of this embodiment, including the circuit substrate 50 itself and the housing 12 side, can be covered with insulating coating materials (coating materials) 424 and 426 to ensure the insulation of the connection parts between the pins 40 and the leads 38 and the core wire C, so that pressure measurement can be performed with high reliability and high quality.

[0083] <First other method>

[0084] As a first alternative embodiment of the pressure sensor 100, Figure 8 As shown, the exposed portion from the cylindrical shape to the gap between the bottom 124b and the sealing glass 14 in the inner peripheral end surface 124i of the bottom 124b of the spacer 124 in the second embodiment is coated with a resin material and coated with an insulating coating material (insulation improving member) 524. As a result, the insulation resistance of the penetrating protruding portion of the lead 40 on the sealing glass 14 side is improved, thereby ensuring the insulation between the lead 40 and the housing 12, and between the housing 12 and the circuit board 50.

[0085] <Second other method>

[0086] As a second alternative embodiment of the pressure sensor 100, Fig. 9 As shown, a substantially cylindrical metal waterproof case 620 is installed instead of the waterproof case 20 in the above embodiment, and a sealing material 26 is filled outside a cover member 625 described later on the opening end side of the waterproof case 620 to ensure liquid tightness.

[0087] In addition, in the pressure sensor 100, instead of the above-mentioned spacer 124, a resin spacer 624 with a bottom and a cylindrical shape having a short side wall is omitted at the position (height) of the step 124a, and is fixed in such a manner that the bottom 624b abuts against one end surface of the housing 12, and a circuit substrate 50 connecting the pin 40 and the lead 38 is fixed to the other end side opening end 624a of the spacer 624.

[0088] Furthermore, the waterproof housing 620 has a locking portion 620t formed as a recess or rib protruding inwardly so as to form a desired space above the circuit substrate 50, and is supported by engaging with the locking portion 620t through a cover member 625 having an outer shape slightly smaller than the outer shell 12. Therefore, the installation space SR for installing the circuit substrate 50 is ensured without relying on the spacer 124.

[0089] <Third other method>

[0090] As a third other form of the pressure sensor 100 of the above embodiment, Fig.10As shown, the spacer 24 and the like in the above-mentioned embodiment are not used and the housing 12 is replaced by a housing 712 having a substantially bottomed cylindrical shape and a cylindrical side wall portion 712s formed integrally on the outer peripheral side of a cylindrical base portion 712b having the same wall thickness as the housing 12. The housing 712 has a sealing glass 14 and a support column 13 formed integrally in the base portion 712b, and a cover member 725 is covered and fixed in a sealed manner at the end portion of the side wall portion 712s on the opening side, thereby forming a setting space SR for accommodating the circuit board 50 on which the mounting component 50J is mounted.

[0091] In the pressure sensor 100, instead of the above-mentioned spacer 124, a resin spacer 724 with a bottom and a cylindrical shape having a short side wall is formed by omitting one end opening at the position (height) of the step 124a, so that the bottom 724b is abutted and fixed to one end surface side of the base 712b of the housing 712, and the circuit substrate 50 with the pins 40 and the leads 38 connected to the other end opening side of the spacer 724 is positioned and fixed in the middle section within the setting space SR.

[0092] In addition, the pressure sensor 100 has a waterproof shell 720 formed in a roughly cylindrical shape that surrounds the entire outer side of the cover part 725 together with the lateral outer side of the shell 712 in the pressure sensor unit 10. The waterproof shell 720 has an end side opening portion 720a fixed to the peripheral edge portion of the cover 28 to which the joint part 30 is fixed, and is filled with a sealing material 726 from the other end side opening side to be liquid-tightly sealed to the outer peripheral surface side of the shell 712.

[0093] The scope of the present invention is not limited to the exemplary embodiments shown in the drawings, but also includes all embodiments that bring about the same effect as the purpose of the present invention. In addition, the scope of the present invention is not limited to the combination of the features of the present invention determined by each technical solution, but can be divided by all desired combinations of all the 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 into a housing, characterized in that: The sensor is installed in the pressure chamber so as to bear the pressure of the object to be measured, and the circuit board is installed in the installation space formed by filling the sealing material in the housing to be liquid-tight. A space forming member for forming the installation space and an insulation improving member for improving the insulation resistance between the space forming member and the circuit substrate are provided. The mounting components of the circuit board are located in the installation space.

2. The pressure sensor according to claim 1, characterized in that: The insulation improving member is constituted by a part of the space forming member, and a desired separation distance is set between the space forming member and the circuit board to improve insulation resistance.

3. The pressure sensor according to claim 1, characterized in that: The insulation improving member is formed of at least one of a plate material, a sheet material, or a coating material made of an insulating material and arranged between the space forming member and the circuit board to improve insulation resistance.

4. The pressure sensor according to claim 1, characterized in that: The installation space is formed by being surrounded by the space forming member composed of a side wall portion forming a cylindrical shape capable of accommodating the circuit substrate and a pair of closing members located at both ends of the cylindrical shape and closing the opening. The side wall portion functions as a spacer that provides a desired separation distance between the pair of sealing members and the circuit board and improves insulation resistance. The side wall portion and the pair of closing members constitute the space forming member and the insulation improving member.

5. The pressure sensor according to claim 4, characterized in that: One of the sealing members is integrally formed with the side wall portion into a bottomed cylindrical shape, and the other sealing member is made to function as a cover member of the cylindrical shape. The side wall portion supports at least a portion of a peripheral end portion of the circuit substrate.

6. The pressure sensor according to claim 1, characterized in that: The circuit substrate is disposed between the sensor and the external device. The sensor is conductively connected to the circuit board via a sensor connection pin member penetrating the space forming member. The external connection member led out to the outside and connected to the external device is conductively connected to the circuit board via an external connection pin member penetrating the space forming member.

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