Pressure sensor

Abstract

The invention provides a pressure sensor which can realize a structure for reducing stress applied to a built-in circuit substrate and can be used with high reliability. 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) and is provided in a housing (20), the sensor chip is provided in a liquid-sealed chamber (LR) so as to receive the pressure of the object to be measured, and the circuit board is provided in an installation space (SR) formed so as to be liquid-tightly filled with a sealing material (26) in the housing. The installation space is formed such that the circuit board can be accommodated in a cylindrical member (24), and the cylindrical member cover (25) is covered on the opening side of the cylindrical member so as to be accommodated in the housing.

Description

Technical Field

[0001] The present invention relates to a fluid-tightly molded pressure sensor. 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, Figure 4 As shown, the circuit substrate 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 is generated. This stress sometimes becomes a load on the circuit substrate 1431 itself or a component mounted on the circuit substrate 1431. Summary of the invention

[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 can be used with high reliability.

[0009] One way of inventing a pressure sensor to solve the above-mentioned problem is a pressure sensor, wherein a sensor for detecting the pressure of a measuring object is connected to a circuit substrate, and the circuit substrate is arranged in 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 an installation space formed liquid-tightly by filling a sealing material in the housing, and the installation space is formed in a cylindrical part formed to be able to accommodate the circuit substrate, and a cover part is covered on the opening side of the cylindrical part to be accommodated in the housing.

[0010] The effects of the present invention are as follows.

[0011] Thus, according to one embodiment of the present invention, the circuit board itself and the components mounted on the circuit board are located in the installation space, which can avoid contact with the sealing material and prevent stress loads from being applied to the components mounted on the circuit board in advance. Therefore, a pressure sensor that can be used with high reliability can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 FIG. 1 is a diagram showing a pressure sensor according to an embodiment of the present invention, and is a longitudinal sectional view schematically showing its overall structure.

[0013] Figure 2 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.

[0014] Figure 3 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.

[0015] Figure 4 It is a figure which shows the prior art of this embodiment, and is a longitudinal sectional view which shows the schematic whole structure.

[0016] In the figure: 10—pressure sensor unit, 11—pressure sensor chip, 24—cylindrical part, 24s—side wall part, 26—sealing material, 26a—adhesive for terminal fixing, 30—connector part, 32—diaphragm, 36, 37—relay connection terminal, 36d, 36e, 37d—terminal piece, 36f—planar part, 37f—connecting surface, 38—lead, 40—pin, 50—circuit substrate, 50u—recessed electrode surface, 51, 53—terminal retaining part, 51p, 53p—recessed part, 100—pressure sensor, SR—setting space. DETAILED DESCRIPTION

[0017] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Figure 1 It is a diagram for explaining a pressure sensor according to an embodiment of the present invention.

[0018] exist Figure 1 In the embodiment, the pressure sensor 100 is manufactured as follows: the components are stacked and assembled as described later, and are installed in the 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 (sensor) 11 is output to a control device that controls the refrigeration cycle, that is, an external device A. The pressure sensor 100 of this embodiment is configured to be connectable by connecting the pressure sensor unit 10 housed in the resin waterproof housing 20 to a piping that guides a fluid such as a gas or liquid whose pressure is to be detected, by using a metal joint component 30.

[0019] The waterproof housing 20 is made into a cylindrical shape capable of accommodating the pressure sensor unit 10, and the peripheral edge of the cover 28 of the fixed joint component 30 is connected to the opening 20b on one end side. The joint component 30 is formed with an internal thread 30s in a manner that can 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 the pressure chamber PR, which is a space surrounded by the cover 28, the housing 12, and the diaphragm 32 described later, through a port 30a connected to the internal thread 30s. Here, the cylindrical shape is used as an example of a cylindrical shape to explain various components including the waterproof housing 20, the cylindrical component 24 described later, etc., but they do not need to be limited to the cylindrical shape, and, for example, a polygonal cylindrical shape can also be adopted.

[0020] The pressure sensor unit 10 comprises: a housing 12 which is made into a short cylindrical shape and whose axial lower end surface is joined and fixed to a cover 28; a pillar 13 which is provided with a pressure sensor chip 11 and is arranged in a manner to be located at the center of the inner cylinder of the housing 12; and a sealing glass 14 which fills and seals around the pillar 13 in the inner cylinder of the housing 12 and fixes the components that pass through the inner cylinder.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] The pressure sensor chip 11 is configured to be supplied with power by connecting a plurality of leads (external connection components) 38 from an external device A to pins (pin components) 40 connected via a circuit substrate 50 described later via bonding wires 11w, and output a 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 an 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.

[0025] 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 accommodates the pressure transmission medium to flow freely between the pressure sensor chip 11 side and the diaphragm 32 side through the communication holes 17a formed in the shielding plate 17 and suppressing sudden pressure changes.

[0026] The pins 40 are arranged on the bottom portion 24b of the resin cylindrical member 24 formed into a short cylindrical shape with a bottom, and two power terminals, one output signal terminal, and five adjustment terminals used in assembly, and are electrically connected to the pressure sensor chip 11 via bonding wires 11w. These pins 40 are inserted into the insertion holes 24h formed in the bottom portion 24b of the cylindrical member 24, and are fixedly supported by the sealing glass 14. Among them, a part of the substantially cylindrical side wall portion 24s of the cylindrical member 24 is formed into a flat surface at a symmetrical position at the center of the cylinder, and the terminal holding portions 51 and 53 for mounting and holding a set of three relay connection terminals (contact members) 36 and 37 described later are arranged at the portion formed into a flat surface.

[0027] One end of the pin 40 passes through the liquid seal chamber side of the sealing glass 14 in the inner cylinder of the housing 12, and the pressure sensor chip 11 is conductively connected to the one end side of the liquid seal chamber LR side via the bonding wire 11w. In addition, on the other end side of the power supply terminal and the output signal terminal among the plurality of pins 40, the terminal piece (connection surface) 36e of the relay connection terminal 36 held on the side wall portion 24s of the cylindrical member 24 extends in the intersecting direction, and is conductively connected to the end surface by, for example, appropriately elastically deforming and high-quality spot welding (or molten metal bonding). In addition, on the opposite (opposite) side of the relay connection terminal 36 of the side wall portion 24s of the cylindrical member 24, a relay connection terminal 37 connected to a lead 38 from an external device A is held as described later. On the terminal pieces (connection surfaces) 36d and 37d of these relay connection terminals 36 and 37, a circuit substrate 50 in a flat plate shape extending in a parallel direction is placed in a loading manner, and is connected by soldering by applying molten solder (conductive connection material) S. In addition, as the conductive connection material, not only molten metal such as solder S can be applied, but also, of course, adhesives containing conductive materials can be applied. In addition, as described above, in addition to conductive connection using soldering and conductive adhesives, conductive connection can also be performed by welding (for example, spot welding using lasers, etc.), and there is no need to specifically limit the means of welding.

[0028] 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, an input-output voltage 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 and DC3.3V of the external device A become the operating voltage DC5V 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 and 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.

[0029] The cylindrical member 24 has a cylindrical member cover (cover member) 25 installed on the opening side of the cylindrical side wall portion 24s (the other opening end side of the cylindrical member 24), and forms a space SR for installing the pins 40, the terminal pieces 36d, 36e, 37d of the relay connection terminals 36 and 37, and the circuit substrate 50. The outer peripheral edge of the cover 28 connected to the connector member 30 is welded to the pressure sensor unit 10 from the outside by TIG welding, plasma welding, laser welding, etc., and is integrated with a desired bonding strength. The pressure sensor unit 10, the cylindrical member 24 forming the installation space SR, and the cylindrical member cover 25 are built into the waterproof housing 20, and are waterproofed and fixed by filling a sealing material 26 such as a polyurethane resin. Among them, by arranging the circuit substrate 50 in the installation space SR formed by the cylindrical member 24 and the cylindrical member cover 25, an air layer with low thermal conductivity can be formed around the circuit substrate 50, and the temperature change from 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, the mounted parts mounted on the circuit substrate 50, or the connection parts between the circuit substrate 50 and the relay connection terminals 36 and 37 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 connection parts, the mounted parts, and especially the soldered parts thereof.

[0030] Furthermore, the pressure sensor 100 is easily and simply assembled with excellent workability by stacking (stacking) the cylindrical member 24, the circuit board 50, and the cylindrical member cover 25 in a sequence (manufacturing method) from the housing 12 fixed to the cover 28 connected to the joint member 30. After the cylindrical member 24 has the relay connection terminals 36 and 37 arranged on the terminal holding portions 51 and 53 of the side wall portion 24s, the end side of one side of the cylindrical member 24 is placed on the housing 12 forming the pressure sensor unit 10 and the end of the pin 40 is spot welded to the terminal piece 36e of the relay connection terminal 36, and then the circuit board 50 is placed on the terminal pieces 36d and 37d of the relay connection terminals 36 and 37 and soldered to conduct the connection. Of course, it is not limited to spot welding, and the terminal piece 36e of the relay connection terminal 36 and the end face of the pin 40 can also be connected by soldering, riveting, etc. In addition, insertion holes and the like are appropriately opened in the bottom portion 24b of the cylindrical member 24 so that the assembly operation can be performed, for example, an insertion hole (not shown) for the oil filling tube 44 is also opened. By providing the pin 40 and the insertion holes for the oil filling tube 44 in the cylindrical member 24, the power supply terminal and the output signal terminal to be connected can be determined in the connection between the terminal piece 36e and the pin 40, and the wrong connection with the pin 40 can be prevented. In addition, even if the bottom portion 24b is not provided in the cylindrical member 24, for example, a step, a concave-convex, etc. for engagement can be formed at the portion of the housing 12 where the cylindrical member 24 is placed, and the position of the cylindrical member 24 relative to the circumferential direction of the housing 12, that is, the arrangement direction of the pin 40 can be determined by engaging with these steps and concave-convex.

[0031] Specifically, the cylindrical member 24 has the relay connection terminals 36 and 37 mounted on and held by the terminal holding portions 51 and 53 formed on the side wall portion 24 s.

[0032] The relay connection terminal 36 is formed in a so-called U-shaped shape, in which the end pieces (terminal pieces) at one end and the other end are extended in a long strip shape and face each other, and the flat surface 36f between the terminal pieces 36d and 36e at the two end sides extending in parallel is formed along the outer surface of the terminal holding portion 51 of the cylindrical member 24, and the terminal pieces 36d and 36e are extended into the side wall portion 24s. The relay connection terminal 37 is similarly formed in a U-shaped shape with a bent piece 37e, which is formed by extending the terminal piece 37d into the side wall portion 24s of the cylindrical member 24 so that the flat connection surface 37f is along the outer surface of the terminal holding portion 53, and the opposite side of the terminal piece 37d is bent. The core wire C of the lead 38 from the external device A is soldered to the connection surface 37 f of the relay connection terminal 37 , thereby electrically connecting the pressure sensor chip 11 to the external device A via the pins 40 , the relay connection terminals 36 , 37 , and the circuit board 50 .

[0033] The terminal holding parts 51 and 53 are installed by inserting the terminal pieces 36d, 36e, and 37d of the relay connection terminals 36 and 37 into the slits formed in the side wall part 24s of the cylindrical member 24 and penetrating therethrough to ensure a large connection surface, and by fitting the bent piece 37e of the relay connection terminal 37 into the recessed part 53p formed on the outer surface of the side wall part 24s under the terminal holding part 53. In the side wall part 24s of the cylindrical member 24, a recessed part 51p is also formed under the terminal holding part 51, and the terminal piece 36e of the relay connection terminal 36 is inserted into the slit, and the sealing material 26 filled in the waterproof housing 20 enters these recessed parts 51p and 53p, thereby fixing the relay connection terminals 36 and 37 to the cylindrical member 24. Alternatively, after the relay connection terminals 36 and 37 are mounted on the cylindrical member 24, the terminal fixing adhesive 26a (shown as 26a in the figure) may be applied and filled in the recessed portions 51p and 53p to fix the terminals.

[0034] The outer peripheral end surface of the portion of the circuit substrate 50 corresponding to the terminal pieces 36d and 37d of the relay connection terminals 36 and 37 is recessed in a U-shaped direction parallel to the plane of the circuit substrate 50, i.e., inwardly, to form a concave wall electrode surface (concave wall surface) 50u of the connection area opened on both the front and back sides orthogonal to the plane of the circuit substrate 50. The concave wall electrode surface 50u allows the molten solder to easily penetrate from the outer peripheral end surface of the circuit substrate 50 to the semicircle of the whole (entire surface) and enter the inner side, thereby performing electroplating with excellent solder wettability on the inner surface, and the terminal pieces 36d and 37d of the relay connection terminals 36 and 37 are also electroplated in the same way to achieve high-quality conduction connection. That is, the concave wall electrode surface 50u is formed into an elliptical cutout shape from the outer peripheral end surface of the circuit substrate 50 toward the inner side of the substrate. By setting the shape recessed to the inner side of the concave wall surface in a semicircular shape, it is expected that the stress inside the concave wall surface 50u in the formation of the solder fillet will act evenly. In addition, in the manufacturing process of the circuit substrate 50, it is also possible to use the same processing tools as those used for processing the mounting holes for mounting parts and processing the outer shape of the circuit substrate 50. In the case of a rectangular shape, other processes and other tools such as processing using a disc-shaped cutter are required. By setting it to a semicircular shape, it is advantageous in terms of productivity and quality. Among them, the concave wall electrode surface 50u is not limited to the outer peripheral end surface on the opposite side of the circuit substrate 50, as long as it is a position separated in a manner that can be soldered without short circuit, and as long as it is formed in a position that is equally or unequally separated in a manner that can be connected at multiple locations according to the situation of the circuit to be formed. For example, the concave wall electrode surface 50u can also be formed on the outer peripheral end surface on the opposite side of the circuit substrate 50 in the radial direction at equal intervals located at the center of the pillar 13 in a manner corresponding to the pin 40. Therefore, in the circuit substrate 50, there will be no concave wall electrode surface 50u as in the example Figure 4 By reducing the circuit formation area as in the type of pin connection by forming a circular ring-shaped circuit for connection around the through-hole, it is possible to ensure a larger installation area for mounting parts. That is, it is possible to have freedom in the layout of the parts configuration and wiring pattern on the circuit substrate without being affected by the through-hole for inserting the pin. In addition, in the present embodiment, the relay connection terminals 36 and 37 are arranged in an opposing manner. By such an arrangement, the wiring pattern for power supply and signal transmission to the circuit substrate 50 becomes a roughly uniform length, which can simplify the wiring pattern of the circuit substrate 50. In addition, in the soldering operation of the concave wall electrode surface 50u and the terminal pieces 36d and 37d, by making the shape of the connection portion uniform, the heat capacity of the soldering is also roughly equal, so that uniform soldering can be performed or the workability is better than that of setting it to a separated position.

[0035] In contrast, the terminal pieces 36d and 37d of the relay connection terminals 36 and 37 are formed wider than the concave wall electrode surface 50u of the circuit substrate 50 and are formed longer than the depth from the outer peripheral end surface of the concave wall electrode surface 50u, so that the circuit substrate 50 can be placed in a stable posture. Furthermore, the cylindrical member 24 can be embedded in the pillar-shaped portion (not shown) at the four corners of the circuit substrate 50 to be positioned. That is, the terminal pieces 36d and 37d of the relay connection terminals 36 and 37 function as a support area near the concave wall electrode surface 50u of the circuit substrate 50. In addition, in the present embodiment, the concave wall electrode surface 50u is formed in the connection area of ​​the circuit substrate 50 of both sides connected to the terminal pieces 36d and 37d of the relay connection terminals 36 and 37, but it is not limited to this. The concave wall electrode surface 50u may be not formed and the connection may be made on the outer peripheral end surface of the circuit substrate 50, or the concave wall electrode surface 50u may be provided only on one side, but it is preferably formed on both sides from the perspective of connection workability and reliability.

[0036] Thus, the circuit substrate 50 is placed on the terminal pieces 36d and 37d of the relay connection terminals 36 and 37 in a stable posture and is held in a stable posture in a positioning shape (not shown) positioned on the cylindrical member 24, and the half elliptical concave wall electrode surface 50u is connected to the terminal pieces 36d and 37d with high reliability through the solder S of a stable shape with a larger capacity than the semicircular concave wall electrode surface and sufficient solder leg height. The soldering part, that is, the connection area, becomes the back side of the circuit substrate 50, so the connection area cannot be directly visually confirmed. However, as in the present embodiment, the state of the solder leg inside the concave wall portion 50u is managed by visual inspection or image recognition, etc., thereby making it possible to determine whether soldering is performed normally.

[0037] Thus, in the pressure sensor 100 of the present embodiment, the circuit substrate 50 connected in series and interposed between the sensor chip 11 and the external device A is accommodated in the installation space SR in the housing 20 which is sealed liquid-tightly by filling the sealing material 26. The installation space SR is formed by covering the cylindrical member cover 25 on the cylindrical member 24 which is positioned and fixed by inserting the terminal pieces 36d, 37d, 36e of the relay connection terminals 36, 37 which are conductively connected to the concave wall electrode surface 50u of the outer peripheral end surface of the circuit substrate 50, the pin 40, and the lead wire 38 into the inner part.

[0038] Therefore, in the pressure sensor 100, the circuit substrate 50 located in the installation space SR formed by the cylindrical member 24 and the cylindrical member cover 25 can prevent the mechanical load of the sealing material 26 of the high-temperature resin melted during manufacturing from directly contacting, 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, etc. from being applied as stress load to the substrate itself and the mounted parts. In addition, in the pressure sensor 100, the rapid temperature change corresponding to the installation environment is not blocked by the pins 40 and the like exposed in a small volume in the installation space SR, and the temperature change can be mitigated by heat transfer to the relay connection terminals 36 and 37, and condensation caused by the large temperature difference between the pins 40 with a small volume and the internal space can be avoided. That is, the pressure sensor of the present embodiment is mainly used for measuring the pressure of the refrigerant piping in the refrigeration cycle. As the temperature of the refrigerant drops sharply, a temperature difference is generated between the liquid contact part, that is, the joint component 30, which is in a low-temperature state, and the setting space SR. However, due to the small volume of the pin 40, the low temperature of the liquid contact part is difficult to be transmitted to the setting space SR, so that the generation of significant condensation can be suppressed. In addition, in the present embodiment, the relay connection terminal 36 is led out to the outside of the cylindrical component 24 forming the setting space SR, and together with the relay connection terminal 37, it contacts the sealing material 26 that is tightly attached to the housing 20 that is in contact with the external air and is connected to the circuit substrate 50. In this way, the low-temperature heat transfer transmitted along the pin is blocked by the terminal and the sealing material, and condensation around the circuit substrate can be suppressed, and the occurrence of short circuit and ion migration caused by condensation can be suppressed.

[0039] Thus, it is possible to provide the pressure sensor 100 which can suppress the occurrence of short circuits, migration, and the like due to condensation and can be used with high reliability.

[0040] As a first alternative embodiment of the pressure sensor 100 of this embodiment, Figure 2 As shown, the cylindrical member 24 in the above-described embodiment is not used, but the housing 12 is covered with a cylindrical member cover 125 which is integrated with a cover member to form an installation space SR for accommodating the circuit board 50 .

[0041] The pressure sensor 100 is configured to connect the pins 40 connected to the sensor chip 11 to the circuit board 50 in the installation space SR without using the relay connection terminals 36 and 37 , and to connect the leads 38 connected to the external device A to the circuit board 50 in the installation space SR.

[0042] Specifically, the pin 40 and the circuit substrate 50 are electrically connected to the two end sides of a flexible wiring component (for example, it can also be a flexible substrate or lead having a wiring circuit) 136, and the pin 40 is connected to one end of the wiring component 136 by spot welding, etc., and the other end of the wiring component 136 is conductively connected to a contact component 138 that passes through both sides of the circuit substrate 50 and is soldered.

[0043] In the lead 38 (core wire C) and the circuit substrate 50, the two end sides of the contact part 126 that passes through the cylindrical part cover 125 are respectively conductively connected and electrically connected, and the core wire C of the lead 38 is soldered and connected to one end side of the contact part 126 located outside the cylindrical part cover 125, and at the same time, the other end side of the contact part 126 located inside the cylindrical part cover 125 passes through and is soldered to the two sides of the circuit substrate 50 and is conductively connected.

[0044] The pressure sensor 100 of the first alternative embodiment is assembled by placing the peripheral edge of the circuit substrate 50 on the step 125a formed on the inner peripheral surface of the middle section with the opening side of the cylindrical component cover 125 facing upward, and then turning it upside down to be accommodated in the housing 20 and filled with the sealing material 26, so as to be made into a liquid-tight structure. In addition, the pressure sensor 100 is coated with an adhesive 126a in the through hole 125h of the cylindrical component cover 125 through which the contact member 126 passes, so as to restrict the intrusion of the sealing material 26 into the installation space SR. In addition, an adhesive 127 is coated on the installation space SR side of the support 13 and the housing 14 to ensure insulation around the pin 40.

[0045] Thus, in the first other mode of the pressure sensor 100, similarly to the above-mentioned embodiment, the circuit substrate 50 between the sensor chip 11 and the external device A can be accommodated in the installation space SR in the liquid-tightly sealed housing 20, and the mechanical load applied during manufacturing, use, etc. and the stress load of thermal stress caused by temperature changes can be prevented in advance.

[0046] As a second other embodiment of the pressure sensor 100 of this embodiment, Figure 3 As shown, instead of using the cylindrical component cover 25 in the above-mentioned embodiment, a cylindrical component 124 with a cylindrical shape having openings at both ends is covered on the housing 12 and closes the opening at one end, while a cover component 151 is provided to cover the opening at the other end, thereby forming a setting space SR for accommodating the mounting parts of the circuit substrate 50.

[0047] The pressure sensor 100 is configured to connect both the pins 40 connected to the sensor chip 11 and the leads 38 (core wires C) connected to the external device A to the circuit board 50 (mounted component) in the installation space SR thereof without using the relay connection terminals 36 and 37 .

[0048] Specifically, the pin 40 is configured to pass through a through hole 50h1 formed on the circuit substrate 50 and be connected to the circuit by direct soldering, etc., and the lead 38 is configured to pass through a through hole 151h formed on the cover part 151, and then pass through a through hole 50h2 formed on the circuit substrate 50 and be connected to the circuit by direct soldering, etc.

[0049] The pressure sensor 100 of the second alternative embodiment is constructed such that a bottomed cylindrical spacer 126 is fixed to the housing 12 side in a cylindrical cylindrical member 124, so that a circuit substrate 50 can be placed and fixed on the opening side thereof, and the circuit substrate 50 can be positioned and fixed in the middle section of the installation space SR. In addition, the spacer 126 has an opening 126a formed at the bottom 126b so that the pin 40 can reach the circuit substrate 50.

[0050] In this way, also in the pressure sensor 100 of the second other embodiment, the same operational effects as those of the first other embodiment described above can be obtained.

[0051] In addition, these methods are all structures in which the circuit substrate is arranged as a whole in the setting space SR in order to reduce the stress applied to the circuit substrate. However, it is not limited to this structure, and other parts with strength in the substrate can also be led out of the setting space SR (wiring patterns, mounting parts, etc. exist in the setting space SR) so as to protect the parts of the circuit substrate that are weak to mechanical stress, that is, the wiring pattern of the circuit substrate, the mounting part of the mounting part installed on the circuit substrate, etc. Specifically, although the illustration is omitted, the following structure can also be adopted: other parts are extended from a part of the mounting part of the circuit substrate, the circuit wiring pattern, etc. and penetrate the cylindrical part or the cylindrical part cover, or slits are formed at their boundaries and penetrated, so as to form through holes for conducting connecting leads on the circuit substrate led out of the setting space SR. In the circuit substrate outside the setting space SR, a connection structure for leads that has sufficient strength even in the space filled with sealing material can be adopted.

[0052] 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 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, the circuit substrate being arranged in a housing, the pressure sensor being 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. The installation space is formed in a cylindrical member formed to accommodate the circuit board, and the opening side of the cylindrical member is covered with a cover member and accommodated in the housing.

2. The pressure sensor according to claim 1, characterized in that: The circuit substrate is arranged in a manner interposed between the sensor and the external device, is conductively connected to the sensor via a pin component passing through one open end side of the tubular component, and is conductively connected to the external device via an external connection component led out to the outside from the other open end side of the tubular component.

3. The pressure sensor according to claim 2, characterized in that: The circuit substrate is conductively connected to one or both of the pin member and the external connection member via a contact member.

4. The pressure sensor according to claim 3, characterized in that: The contact member has a connection surface extending in a direction intersecting a connection location of one or both of the pin member and the external connection member.

5. The pressure sensor according to claim 3, characterized in that: The contact member has a connection surface extending in a direction parallel to a connection portion formed along an extending direction of the flat plate shape of the circuit substrate.

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