Pressure Sensor

Abstract

To provide a pressure sensor that prevents a heat radiation adhesive from contacting a conversion substrate.SOLUTION: A pressure sensor comprises: a pressure detection unit; and a signal transmission unit that is adjacent to the pressure detection unit, and that has: a connector housing defining a substrate housing part, a connector connection part, and a partition wall part between the substrate housing part and the connector connection part; a connection terminal; a conversion substrate housed in the substrate housing part; and a heat generating component mounted on the conversion substrate and fixed to the connector housing with a heat radiation adhesive. The heat radiation adhesive is arranged extending to an adhesive retention area that is expanded in a direction orthogonal to a direction in which the signal transmission unit is adjacent to the pressure detection unit. The expanded adhesive retention area has an area of the heat generating component that corresponds to the entirety of a joint range to the heat radiation adhesive extending in a direction in which the pressure detection unit and the signal transmission unit are adjacent to each other, and is expanded in a direction orthogonal to the adjacent direction through the corresponding area. The connector housing and the conversion substrate are provided separated from each other.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a pressure sensor having a conversion substrate provided therein. [Background technology]

[0002] Conventionally, there are pressure sensors in which a conversion board equipped with a conversion circuit that converts both the drive voltage and the pressure detection signal is externally connected between the control circuit and the pressure sensor in order to accommodate various drive voltages and signal formats of the pressure detection signal.

[0003] To solve the problem of poor connection caused by external shocks or vibrations, some pressure sensors omit the cable and place the conversion board inside the pressure sensor. However, the conversion board generates heat due to the transformation of the drive voltage. Therefore, when the conversion board is placed inside the pressure sensor, it is desirable to efficiently dissipate the heat generated in the conversion board and to suppress the heat transfer to the conversion board. If these measures are not implemented effectively, problems such as damage to the electronic components on the conversion board may occur due to temperatures exceeding their heat resistance temperature.

[0004] As a configuration for suppressing heat transfer to the conversion board, Figure 10 of Patent Document 1 describes that heat-generating components such as transistors placed near the conversion board are surrounded by a thermally conductive adhesive, which efficiently dissipates heat from the heat-generating components to the outside and suppresses the thermal impact on the conversion board. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. WO2022 / 097437 Summary of the Invention [Problem to be solved by the invention]

[0006] However, with the configuration described in Patent Document 1, during the manufacturing process of the pressure sensor, a heat-generating component such as a transistor may be inserted into the pre-filled adhesive, which may cause the adhesive to overflow and come into contact with the conversion board. If the adhesive gets onto the conversion board, especially the land portion where soldering is performed, it may cause defects in the soldered portion on the top surface of the board. Furthermore, if the adhesive bridges the conversion board and the heat-generating component, the heat transfer between the heat-generating component and the board makes it impossible to suppress the effects of heat.

[0007] An object of the present invention is to provide a pressure sensor that can prevent a heat dissipating adhesive from coming into contact with a conversion substrate. [Means for solving the problem]

[0008] In order to solve the above problems, the pressure sensor comprises a pressure detection unit that detects the pressure of the fluid and sends it to the outside, a connector housing adjacent to the pressure detection unit, a board accommodating unit, a connector connection unit, and a partition wall between the board accommodating unit and the connector connection unit, connection terminals for connecting signals to the outside, a conversion board that is accommodated in the board accommodating unit and adjusts signals to and from the pressure detection unit via lead pins and to and from the outside via the connection terminals, and a converter board that is mounted on the conversion board and fixed to the connector housing with a heat dissipating adhesive. a heat-generating component; and a signal sending section having the heat-dissipating adhesive, wherein the heat-dissipating adhesive is arranged over an adhesive reservoir area that extends in a direction perpendicular to the direction in which the signal sending section is adjacent to the pressure detection section, and the extended adhesive reservoir area has an area corresponding to the entire bonding range of the heat-generating component with the heat-dissipating adhesive that extends in the direction in which the pressure detection section and the signal sending section are adjacent, and extends in a direction perpendicular to the adjoining direction through the corresponding area, and the connector housing and the conversion board are arranged at a distance from each other.

[0009] In the above pressure sensor, the conversion board may have a chamfered portion on the outer periphery of the conversion board, and the connector housing may have a board anti-rotation member that corresponds to the chamfered portion.

[0010] In the pressure sensor, the conversion substrate may have a notch that extends to the vicinity of a land portion on the conversion substrate. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a pressure sensor that can prevent the heat dissipation adhesive from coming into contact with the conversion substrate. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a cross-sectional view showing a pressure sensor according to an embodiment of the present invention. [Figure 2] 2A and 2B are schematic diagrams showing a pressure sensor body according to an embodiment of the present invention, in which FIG. 2A is a perspective view showing the pressure sensor body before being placed on a substrate, and FIG. 2B is a plan view showing the pressure sensor body after being coated with adhesive before being placed on a substrate. [Figure 3] Figure 3 is a partially enlarged cross-sectional view showing the adhesive reservoir area of ​​the pressure sensor body according to an embodiment of the present invention, where Figure 3(a) is an enlarged top view of the adhesive reservoir area before the heat-generating component is inserted, showing part IIIa in Figure 2(b), Figure 3(b) is a cross-sectional view of the adhesive reservoir area before the heat-generating component is inserted, and Figure 3(c) is a cross-sectional view of the adhesive reservoir area after the heat-generating component is inserted. [Figure 4] 4A and 4B are schematic diagrams showing a pressure sensor body according to an embodiment of the present invention, in which FIG. 4A is a perspective view showing the pressure sensor body after being placed on a substrate, and FIG. 4B is a plan view showing the pressure sensor body after being placed on a substrate. [Figure 5] FIG. 5(a) is a cross-sectional view showing a pressure sensor according to another embodiment of the present invention, and FIG. 5(b) is a cross-sectional view showing a pressure sensor according to yet another embodiment of the present invention. [Figure 6]FIG. 6 is a cross-sectional view showing a pressure sensor according to still another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] An embodiment of the present invention will be described in detail with reference to Figures 1 to 6. However, the present invention is not limited to this embodiment.

[0014] The pressure sensor 100 according to the embodiment of the present invention includes a heat dissipation means from the conversion board 133 and a heat transfer suppression means to the conversion board 133, thereby effectively dissipating heat generated in the conversion board 133 to the external environment and suppressing heat transfer from the fluid whose pressure is to be detected to the conversion board 133. Here, the heat dissipation means of the conversion board brings the conversion board 133 (including heat-generating components) into indirect thermal contact with the connector housing 131. Therefore, a case where the conversion board 133 is in indirect thermal contact with the connector housing 131 as the heat dissipation means of the conversion board 133 will be described.

[0015] <Terminology> In the description of this specification and the claims, "one end" and "the other end" refer to the "lower end" and "upper end" in the drawings.

[0016] <Pressure sensor configuration> A pressure sensor 100 according to an embodiment of the present invention will be described with reference to FIG.

[0017] The pressure sensor 100 is composed of a fluid introduction section 110, a pressure detection section 120, a signal transmission section (main body) 130, and a connecting member 140. Each component of the pressure sensor 100 will be described below in order. After the fluid introduction section 110 and the pressure detection section 120 are joined and fixed, and the pressure detection section 120 and the signal transmission section 130 are electrically connected, the fluid introduction section 110, the pressure detection section 120, and the signal transmission section 130 are integrally assembled using the connecting member 140.

[0018] <Fluid introduction section> The fluid introduction section 110 introduces the fluid whose pressure is to be detected into a pressure chamber 112A described later, and includes a metal joint member 111 and a metal base plate 112 connected to the other end of the joint member 111 by welding or the like.

[0019] The coupling member 111 has a female thread portion 111a that is connected to a pipe (not shown) that introduces a fluid whose pressure is to be detected, and a port 111b that guides the fluid introduced from the pipe to the pressure chamber 112A. The open end of the port 111b is connected by welding or the like to an opening provided in the center of the base plate 112. In this embodiment, the coupling member 111 has the female thread portion 111a, but is not limited to this. For example, the coupling member 111 may have a male thread portion, or a copper connecting pipe may be connected instead of the coupling member 111.

[0020] The base plate 112 has a bowl shape that expands in diameter from one end to the other end in the radial direction relative to the central axis C of the pressure sensor 100, and forms a pressure chamber 112A between itself and a diaphragm 122, which will be described later.

[0021] <Pressure detection section> The pressure detection unit 120 detects the pressure of the fluid in the pressure chamber 112A and includes a housing 121 with a through hole, a diaphragm 122 that separates the pressure chamber 112A from a liquid-sealed chamber 124A described below, and a protective cover 123 that is arranged on the pressure chamber 112A side of the diaphragm 122. The pressure detection unit 120 also includes hermetic glass 124 sealed inside the through hole of the housing 121, liquid-sealed chamber 124A that is filled with sealed oil between the diaphragm 122 and a recess on the pressure chamber 112A side of the hermetic glass 124, and a support post 125 that is arranged in the center of the hermetic glass 124. Furthermore, the pressure detection unit 120 includes a semiconductor sensor chip 126 supported by a support 125 and placed inside the liquid-sealed chamber 124A, a potential adjustment member 127 placed around the liquid-sealed chamber 124A, a plurality of lead pins 128 fixed to the hermetic glass 124, and an oil filling pipe 129 fixed to the hermetic glass 124.

[0022] The housing 121 is made of a metal material such as an Fe-Ni alloy or stainless steel to maintain the strength around the hermetic glass 124. The diaphragm 122 and the protective cover 123 are both made of a metal material and are welded to each other at the outer periphery of the through hole on the pressure chamber 112A side of the housing 121. The protective cover 123 is provided inside the pressure chamber 112A to protect the diaphragm 122, and is provided with a plurality of communication holes 123a through which the fluid introduced from the fluid introduction portion 110 passes. After the pressure detection portion 120 is assembled, the housing 121 is welded from the outside at the outer periphery of the base plate 112 of the fluid introduction portion 110 by TIG welding, plasma welding, laser welding, or the like.

[0023] The hermetic glass 124 is provided to protect the liquid-sealed chamber 124A, in which the semiconductor sensor chip 126 is liquid-sealed, from ambient environmental conditions such as moisture, dust, and heat, to hold the multiple lead pins 128, and to insulate the multiple lead pins 128 from the housing 121. The semiconductor sensor chip 126 is supported by an adhesive or the like on the liquid-sealed chamber 124A side of the support 125, which is located in the center of the hermetic glass 124. Note that, although the support 125 is made of an Fe-Ni alloy in this embodiment, the material is not limited to this. For example, the support 125 may be made of another metal material such as stainless steel, or the support may be directly supported on the flat surface forming the recess of the hermetic glass 124 without the support 125.

[0024] The semiconductor sensor chip 126 contains a diaphragm made of a material having a piezo-resistance effect (for example, single crystal silicon), a bridge circuit in which a plurality of semiconductor strain gauges are formed on the diaphragm and bridge-connected, an amplifier circuit for processing the output from the bridge circuit, and an integrated circuit such as an arithmetic processing circuit. The semiconductor sensor chip 126 is connected to a plurality of lead pins 128 by bonding wires 126a made of, for example, gold or aluminum, and the plurality of lead pins 128 form external input / output terminals of the semiconductor sensor chip 126.

[0025] The potential adjusting member 127 is provided to place the semiconductor sensor chip 126 in an electric field-free environment (zero potential) and to prevent the circuits in the chip from being adversely affected by the potential generated between the frame earth and the secondary power supply. The potential adjusting member 127 is disposed between the semiconductor sensor chip 126 and the diaphragm 122 in the liquid-sealed chamber 124A, is made of a conductive material such as metal, and is connected to a terminal of the semiconductor sensor chip 126 that is connected to the zero potential.

[0026] A plurality of lead pins 128 and an oil filling pipe 129 are fixed to the hermetic glass 124 by hermetic processing in a penetrating state. In this embodiment, a total of eight lead pins 128 are provided. That is, three lead pins 128 are provided for external output (Vout), drive voltage supply (Vcc), and ground (GND), and five lead pins 128 are provided as terminals for adjusting the semiconductor sensor chip 126. Note that four of the eight lead pins 128 are shown in FIG. 1.

[0027] The oil filling pipe 129 is provided to fill the interior of the liquid-sealed chamber 124A with sealed oil (for example, silicone oil or a fluorine-based inert liquid, etc.). After filling with oil, the other end of the oil filling pipe 129 is crushed and closed as shown in FIG.

[0028] <Operation of the pressure detection unit> The operation of the pressure detection unit 120 will be described. First, the diaphragm 122 is pressed by the fluid introduced into the pressure chamber 112A from the joint member 111. The pressure of the pressure chamber 112A applied to this diaphragm 122 is transmitted to the semiconductor sensor chip 126 via the sealed oil in the liquid-sealed chamber 124A. This transmitted pressure deforms the silicon diaphragm of the semiconductor sensor chip 126, and the pressure is converted into an electrical signal by a bridge circuit using piezo-resistance elements, which is output from the integrated circuit of the semiconductor sensor chip 126 to the signal sending unit 130 via the bonding wires 126a and the multiple lead pins 128.

[0029] <Signal sending section> The signal sending unit (main body) 130 sends the pressure signal detected by the pressure detecting unit 120 to the outside, and includes a connector housing 131 for external connection arranged adjacent to the other end of the pressure detecting unit 120, and a flexible connecting wire 132 having one end connected to the plurality of lead pins 128. The signal sending unit 130 also includes a conversion board 133 fixed to the connector housing 131 via three connection terminals, and the above-mentioned connection terminals 134a to 134c having one end connected to the conversion board 133 by passing through them. An opening 133f is formed in the conversion board 133 to avoid interference with the oil filling pipe 129.

[0030] The connector housing 131 is formed from an insulating resin or the like having a relatively high thermal conductivity, and includes a substrate accommodating portion 131a having a recessed shape on one end, a connector connection portion 131b having a recessed shape on the other end and connected to an external connector (not shown), and a partition wall portion 131c disposed between the substrate accommodating portion 131a and the connector connection portion 131b. A plurality of lead pins 128 and an oil filling pipe 129 extending from the hermetic glass 124, a flexible connecting wire material 132, a conversion substrate 133, etc. are disposed in the internal space S defined by the substrate accommodating portion 131a.

[0031] The conversion board 133 includes a conversion circuit (not shown) that converts both the drive voltage and the pressure detection signal to accommodate the drive voltage and the signal format of the pressure detection signal. This conversion circuit includes a step-down circuit unit (not shown) that steps down the drive voltage (e.g., 8 V to 36 V) of a control circuit (not shown) connected to the outside of the pressure sensor 100 via connection terminals 134a to 134c to the drive voltage (e.g., 5.0 V) of the semiconductor sensor chip 126, and a voltage shift circuit unit (not shown) that boosts the pressure detection signal (e.g., 0.5 V to 4.5 V) of the pressure sensor 100 to the pressure detection signal (e.g., 1 V to 5 V) of the control circuit. In this way, by appropriately selecting the conversion board 133 to be provided within the pressure sensor 100 according to the drive voltage and the signal format of the pressure detection signal, it is possible to absorb differences in the drive voltage and the pressure detection signal without changing the design of the pressure detection unit 120, particularly the semiconductor sensor chip 126, or the peripheral structure of the liquid-sealed chamber 124A.

[0032] At least three connection terminals 134a-c are provided: one for external output (Vout), one for supplying drive voltage (Vcc), and one for ground (GND). To improve assembly, for example, in the case of connection terminal 134a, one end 134d of connection terminal 134a is inserted into a through-hole provided in conversion board 133, and this through-hole is soldered to connect connection terminal 134a to conversion board 133. A land portion 133n is formed at the connection portion of conversion board 133, and is electrically connected to electrode 135 via a conductive pattern. Meanwhile, the other end of connection terminal 134a penetrates partition wall portion 131c and extends to connector connection portion 131b. The through-holes of partition wall portion 131c through which connection terminals 134a-c penetrate are sealed with connection terminal fixing adhesive 134g.

[0033] <Connection parts> The connecting member 140 includes a crimping plate 141 that connects and fixes the fluid introduction section 110, the pressure detection section 120, and the signal sending section 130 by crimping, and an adhesive sheet 142 that is placed between the pressure detection section 120 and the signal sending section 130.

[0034] The crimping plate 141 is formed into a cylindrical shape from a metal such as copper. The crimping plate 141 is disposed around the fluid introduction portion 110, the pressure detection portion 120, and the signal sending portion 130, and is fixed to the fluid introduction portion 110 and the signal sending portion 130 by crimping. By this crimping, the adhesive sheet 142 is sandwiched between the pressure detection portion 120 and the signal sending portion 130 to achieve waterproof and dustproof functions. Note that a non-metallic resin sheet 151 having thermal emissivity and an adhesive 152 having thermal emissivity may be sandwiched between the adhesive sheet 142 and the housing 121 as means for suppressing heat transfer to the conversion board 133.

[0035] <Heat dissipation means for conversion board> The conversion board 133 has an end surface 133b, on which various electronic components are mounted and which is spaced from the connector housing 131, and an end surface 133a, to which the connection terminals 134a-c, etc. are soldered. In this embodiment, the heat-generating component 133h (e.g., a transistor, a regulator, etc.) is a lead type and is mounted on the end surface 133b. The conversion board 133 generates heat due to the transformation of the drive voltage, etc. If no countermeasures are taken, the electronic components on the conversion board may exceed their heat resistance temperature and be damaged. Therefore, in this embodiment, various heat dissipation means for the conversion board 133 are employed to prevent the electronic components of the conversion board 133 from exceeding their heat resistance temperature. This allows heat generated in the conversion board 133 to be efficiently dissipated to the external environment, thereby improving the tolerance for the heat resistance temperature of the conversion board 133. The heat dissipation means for the conversion board 133 in this embodiment will be specifically described below.

[0036] <Heat dissipation means for conversion boards (lead-type heat-generating components)> A lead-type heat-generating component 133h is used as a heat dissipation means for the conversion board 133, forming a heat dissipation path indicated by the dashed line (1) in FIG. 1 . The lead-type heat-generating component 133h is provided on the board-facing surface 131a1 side. A heat-dissipating adhesive 133g having thermal conductivity is filled around the heat-generating component 133h. To prevent the heat-dissipating adhesive 133g from spreading onto the conversion board, an adhesive reservoir wall 131w is provided between the heat-generating component 133h and the outer periphery of the connector housing 131, defining an adhesive reservoir region 131e. That is, in this embodiment, the adhesive reservoir region 131e is defined by the adhesive reservoir wall 131w, the board accommodating portion 131a of the main body 130, and the partition wall 131c. The adhesive reservoir region 131e accommodates a lead-type heat-generating component 133h, and a heat-dissipating adhesive 133g having thermal conductivity is filled only between the adhesive reservoir region 131e and the lead-type heat-generating component 133h. As a result, in this embodiment, heat generated in the heat-generating component 133h is actively transferred to the heat-dissipating adhesive 133g having thermal conductivity that surrounds the heat-generating component 133h, thereby enabling more efficient heat dissipation to the external environment via the connector housing 131. In this regard, it is desirable that the adhesive reservoir region 131e, which is surrounded by the adhesive reservoir wall surface 131w and the inner wall of the connector housing 131 in a plan view, be formed in a direction perpendicular to the insertion direction of the lead-type heat-generating component 133h (forward, backward, leftward, or rightward in a plan view of FIG. 2(b)), as shown in FIG. This is because the surface area of ​​the adhesive reservoir region 131e can be increased by forming the adhesive reservoir wall surface 131w in a rectangular shape in plan view as in this embodiment, rather than by forming a shape that connects the intersection of the adhesive reservoir wall surface 131w and the inner wall portion of the connector housing 131 in the shortest distance or by forming a shape that connects both ends of the adhesive reservoir wall surface 131w with a gentle curve (e.g., an arc). This allows a larger amount of heat generated in the heat-generating component 133h to move to the heat-dissipating adhesive 133g that has thermal conductivity and surrounds the heat-generating component 133h. Furthermore, by forming the adhesive reservoir wall surface 131w in a rectangular shape in plan view so as to avoid the connection terminals 134b and 134c as shown in FIG. 2(b), space can be used more efficiently.Furthermore, since the lead-type heat-generating component 133h is mounted on the conversion board 133 via the lead 133l, the heat-generating portion of the heat-generating component 133h is physically separated from the conversion board 133, thereby preventing the electronic components of the conversion board 133 from exceeding their heat resistance temperature.

[0037] Here, the lead-type heat generating component 133h is provided on the outer diameter side of the connector housing 131 so as to be close to the outside air. This makes it easier for the heat dissipating adhesive 133g filled around the lead-type heat generating component 133h to dissipate heat to the outside of the connector housing 131.

[0038] Furthermore, by providing a space between the heat-dissipating adhesive 133g filled around the lead-type heat-generating component 133h and the conversion board 133, heat transfer between the heat-generating component 133h and the conversion board 133 can be suppressed.

[0039] <Heat transfer suppression means> A fluid whose pressure is to be detected is introduced into the pressure chamber 112A. Depending on the conditions of use of the fluid, the introduced fluid may be extremely hot (e.g., approximately 130°C), and may become a heat source. In this case, heat from the pressure detection unit 120 (such as the heat of the high-temperature fluid introduced into the pressure chamber 112A) may transfer to the conversion substrate 133 (heat transfer from one end to the other end in FIG. 1, heat conduction, and heat radiation), potentially canceling out the heat dissipation effect of the heat dissipation means (lead-type heat-generating component). Therefore, in this embodiment, various heat transfer suppression means are employed to prevent the heat from the pressure detection unit 120 (such as the heat of the high-temperature fluid introduced into the pressure chamber 112A) from transferring to the conversion substrate 133. As a result, in this embodiment, the heat transfer from the pressure detection unit 120 to the conversion substrate 133 can be suppressed, thereby enabling the heat dissipation effect of the heat dissipation means (lead-type heat-generating component) to be fully achieved. The means for suppressing heat transfer to the conversion substrate 133 in this embodiment will be specifically described below.

[0040] <First Heat Transfer Suppression Means to the Conversion Board (Internal Space)> The internal space S is used as a first means for suppressing heat transfer to the conversion board 133. Specifically, by providing the conversion board 133 near the other end of the board accommodating portion 131a, the distance L in the internal space S in the direction of the central axis C between the conversion board 133 and the housing 121 on the pressure detection unit 120 side can be set as large as possible. As a result, in this embodiment, heat on the pressure detection unit 120 side can be suppressed from being transferred to the conversion board 133 via the internal space S, which has a long heat transfer path and low thermal conductivity and is made of air. However, the conversion board 133 and the other end of the board accommodating portion 131a are not in direct contact with each other, as will be described in the next section.

[0041] <Second Means for Suppressing Heat Transfer to the Conversion Board (Separation of the Conversion Board from the Main Body)> As shown in FIG. 1, the conversion board 133 is spaced apart from the other end and outer periphery of the board accommodating portion 131a so as not to come into direct contact with the connector housing 131. Instead of being directly supported by the connector housing 131, the conversion board 133 is supported at three points by three connection terminals 134a-c, as shown in FIGS. 4(a) and 4(b). These three connection terminals 134a-c are positioned toward the center of the conversion board 133, to which a particular load is applied when the connection terminals 134a-c are soldered to the conversion board 133. Also, as shown in FIG. 1, the three connection terminals 134a-c are not linear but have a stepped structure 134f, which allows the conversion board 133 to be supported at the stepped portion 134f. The position of this stepped portion 134f is set at a height such that the conversion board 133 does not come into contact with the connector housing 131 when the conversion board 133 is accommodated in the connector housing 131, so that the conversion board 133 is supported at three points as described above. With this structure, the converter board 133 can be positioned in a balanced manner without tilting relative to the connection terminals 134a-c even when a load is applied during soldering. The converter board 133 is also configured to be prevented from moving (upward) toward the connector housing 131 and firmly supported by the connection terminals 134a-c. Furthermore, as shown in FIG. 1 , the connection terminals 134a-c themselves are fixed to the connector housing 131 with a connection terminal fixing adhesive 134g, and the lead-type heat-generating component 133h mounted on the converter board 133 is fixed to the connector housing 131 with a heat-dissipating adhesive 133g, thereby indirectly fixing the converter board 133 to the connector housing 131. In this way, the converter board 133 is spaced apart from the other end of the board accommodating portion 131a so as not to come into direct contact with the connector housing 131. This prevents heat transferred from the lead-type heat-generating component 133h to the surrounding heat-dissipating adhesive 133g from being transferred to the converter board 133.

[0042] In addition to the above, the conversion board 133 is provided such that its side is spaced apart from the outer periphery of the board accommodating portion 131a, thereby preventing stress from being applied from the connector housing 131 to the conversion board 133 due to the difference in thermal linear expansion coefficients between the conversion board 133 and the connector housing 131. This makes it possible to prevent damage to the conversion board 133 due to stress applied from the connector housing 131 to the conversion board 133 due to the difference in linear expansion coefficients.

[0043] <Third means for suppressing heat transfer to the conversion board (flexible wiring material)> The flexible wire connection material 132 described above is used as a third means for suppressing heat transfer to the conversion board 133. Specifically, the flexible wire connection material 132 is formed, for example, from a flexible printed circuit board (FPC), a thin conductive member, a lead wire, or an assembly of lead wires, and connects the plurality of lead pins 128 and the electrodes 135 in a curved or bent state in the internal space S. This allows the connection distance between the plurality of lead pins 128 and the electrodes 135 to be set relatively large. Furthermore, the flexible wire connection material 132 is thinner and has a smaller cross-sectional area than ordinary wiring materials. As a result, in this embodiment, heat from the semiconductor sensor chip 126 side can be suppressed from being conducted to the conversion board 133 because the heat is transmitted via the flexible wire connection material 132, which has a long heat transfer path, and because the cross-sectional area is small.

[0044] <Main body assembly process> Fig. 2(a) shows a perspective view of the main body 130 before the converter board 133 is installed on the main body 130, before the connection terminal fixing adhesive 134g is applied, and before the heat dissipation adhesive 133g is filled in the adhesive reservoir area 131e, and Fig. 2(b) shows a plan view of the main body 130 before the converter board 133 is installed on the main body 130, after the connection terminal fixing adhesive 134g is applied, and after the heat dissipation adhesive 133g is filled in the adhesive reservoir area 131e. Note that Fig. 2(a) shows a part of the connector housing 131 cut away so that the inside of the main body can be seen, and this is also the case with Fig. 4(a).

[0045] In the assembly process of the main body 130, first, as shown in FIG. 2(a), three connection terminals 134a-c are inserted into the main body 130. Then, as shown in FIGS. 1 and 2(b), a connection terminal fixing adhesive 134g is applied (filled) around the connection terminals 134a-c so that the inserted connection terminals 134a-c are fixed to the main body 130. However, the applied thickness is determined so that the connection terminal fixing adhesive 134g does not adhere to the conversion substrate 133. Next, as also shown in FIGS. 1 and 2(b), a heat dissipation adhesive 133g is filled into the adhesive reservoir region 131e of the main body 130. However, the heat dissipation adhesive 133g is filled to about half to 80% of the fillable space volume of the adhesive reservoir region 131e, and is not filled to the limit of the fillable volume. Then, the conversion substrate 133 is inserted into the main body 130. At this time, the lead-type heat-generating component 133h is previously attached to the conversion board 133 and protrudes toward the board-facing surface 131a1, so it is inserted into the heat-dissipating adhesive 133g filled in the adhesive reservoir area 131e of the main body 130. Next, the main body 130 with the conversion board 133 inserted is placed in an oven and heated to harden the heat-dissipating adhesive 133g and the connection terminal fixing adhesive 134g. This heating also serves the purpose of drying the conversion board 133 to prevent migration due to moisture absorption by the conversion board 133. Then, the connection terminals 134a-c and the lead-type heat-generating component 133h are soldered to the conversion board 133. Finally, a soldering inspection is performed to confirm that the soldering is performed properly.

[0046] <Insertion of lead-type heat-generating components into heat-dissipating adhesive> Figure 3(a) is an enlarged view of the area IIIa enclosed by a square in Figure 2(b), Figure 3(b) is a side cross-sectional view showing how a lead-type heat-generating component 133h is inserted into the insertion area 133i in Figure 3(a), and Figure 3(c) is a side cross-sectional view showing the rise of the heat-dissipating adhesive 133g after the lead-type heat-generating component 133h is inserted into the insertion area 133i.

[0047] 4(a) is a perspective view of the main body 130 after the conversion board 133 is installed on the main body 130, and FIG. 4(b) is a plan view of the main body of FIG. 4(a) seen from the conversion board 133 side.

[0048] In the assembly process of the main body described above, when a lead-type heat-generating component 133h is inserted into the insertion area 133i of the heat-dissipating adhesive 133g filled in the adhesive reservoir area 131e of the main body 130 as shown in FIG. 3(b), the heat-dissipating adhesive 133g bulges along each surface of the lead-type heat-generating component 133h as shown in FIG. 3(c). If no measures are taken to prevent this, the bulging heat-dissipating adhesive 133g may creep up along the adhesive reservoir wall surface 131w due to surface tension (in the direction of arrow A shown in FIG. 2(a)) and come into direct contact with the conversion board 133 or drip onto the conversion board 133. In particular, if the heat-dissipating adhesive 133g comes into contact with the soldered portion (land portion 133n) of the conversion board 133, this may cause poor soldering. The heat-dissipating adhesive 133g is disposed over an adhesive reservoir area 131e that expands in a direction perpendicular to the direction in which the signal sending unit 130 and the pressure detection unit 120 of the lead-type heat-generating component 133h are adjacent. This is to ensure that even when the lead-type heat-generating component 133h is inserted into the heat-dissipating adhesive 133g, the heat-dissipating adhesive 133g that bulges and spreads in the direction perpendicular to the direction in which the signal sending unit 130 and the pressure detection unit 120 are adjacent can be sufficiently contained and the heat-dissipating adhesive 133g can be prevented from adhering to the conversion board 133. In addition, a notch 133k is provided in a portion of the conversion board 133 where the heat-dissipating adhesive 133g may creep up due to surface tension along the adhesive reservoir wall surface 131w in the direction of arrow A shown in FIG. 2(a). This increases the gap between the conversion substrate 133 and the inner wall of the main body 130, preventing the heat-dissipating adhesive 133g, which bulges and spreads in a direction perpendicular to the direction in which the signal sending unit 130 and the pressure detection unit 120 are adjacent to each other, from creeping up due to surface tension along the adhesive reservoir wall surface 131w. Furthermore, by providing the cutout portion 133k up to the vicinity of the land portion 133n of the conversion substrate 133, even if the heat-dissipating adhesive 133g that has overflowed in the direction perpendicular to the direction in which the signal sending unit 130 and the pressure detection unit 120 are adjacent to each other drips onto the substrate, the heat-dissipating adhesive 133g can be prevented from adhering to the land portion 133n.In this embodiment, the direction in which the signal sending unit 130 and the pressure detecting unit 120 are adjacent to each other coincides with the direction in which the lead-type heat generating component 133h is mounted on the conversion board 133.

[0049] 2(a) and 2(b) and 4(a) and 4(b), in this embodiment, the outer periphery of the conversion board 133, which is circular in plan view, is chamfered at two opposing locations to form chamfered portions 131m. Correspondingly, two board detents 136 are provided on the inner wall of the main body 130, which is circular in plan view. As a result, the circular inner wall of the main body 130 and the circular outer periphery of the conversion board 133 act as guides, and the centers of the conversion board 133 and the main body 130 are aligned in plan view. In this way, by aligning the centers of the outer periphery of the conversion board 133, which is circular in plan view, and the inner wall of the main body 130, in plan view, it is possible to reduce wobbling in the front-to-back and left-to-right directions in plan view. Furthermore, the chamfered portions 131m and the board detents 136 position and orient the conversion board 133. This is to prevent the heat-dissipating adhesive 133g from dripping onto the conversion board 133 and to prevent the conversion board 133 from rotating relative to the main body 130 when and after inserting the conversion board 133 into the main body 130. As shown in FIGS. 4(a) and 4(b), the chamfered portion 131m and the board rotation stopper 136 engage with each other to guide the conversion board 133 when inserting it into the connector housing 131. This eliminates the need to search for insertion positions by, for example, rotating the conversion board 133 to insert the three connection terminals 134a to 134c into the through-holes of the three land portions 133n. This eliminates fluctuations in the liquid surface of the heat-dissipating adhesive 133g that occur when the conversion board 133 rotates relative to the main body 130, thereby preventing the heat-dissipating adhesive 133g from dripping onto the conversion board 133 or spreading over the entire conversion board 133 along the inner periphery of the main body 130. In this embodiment, the chamfered portion 131m and the substrate rotation stopper 136 are configured in a linear shape, but this is not limited thereto, and they may be configured, for example, as a concave and a convex shape and engage with each other. Furthermore, one may have a notch and the other may have a shape corresponding to the notch, thereby achieving the same effect as the chamfered portion 131m and the substrate rotation stopper 136 described above. Also, although two chamfered portions 131m and two substrate rotation stoppers 136 are provided, one or three or more may be provided.When the outer periphery of the conversion board 133 in plan view and the inner wall of the main body 130 in plan view are rectangular, they may have shapes that allow them to fit or engage with each other.

[0050] In addition to the above preventive measures, as shown in Figure 2(b), the insertion area 133i of the lead-type heat-generating component 133h into the heat-dissipating adhesive 133g can also be positioned away from the outer wall surface of the main body 130 to prevent the raised heat-dissipating adhesive 133g from coming into contact with the conversion board 133.

[0051] <Pressure sensor assembly process> Next, the assembly process of the pressure sensor 100 will be described. First, the pressure detection unit 120 and the signal sending unit (main body) 130 are assembled as described above. Then, in the pressure detection unit 120, the liquid-sealed chamber 124A is filled with sealed oil via the oil filling pipe 129, and the oil filling pipe 129 is closed. Furthermore, the fluid introduction unit 110 is fixed to the pressure detection unit 120 by welding or the like. Thereafter, the multiple lead pins 128 of the pressure detection unit 120 and the conversion substrate 133 of the signal sending unit 130 are arranged in parallel so that they face upward, and one end of the flexible connecting wire 132 is fixed to the surfaces of the multiple lead pins 128 and the electrode 135 on the conversion substrate 133, respectively. Furthermore, the pressure detection unit 120 and the signal sending unit 130 are arranged opposite to each other on the same axis via a curved or bent flexible connecting wire 132, and an adhesive sheet 142 is sandwiched between the pressure detection unit 120 and the signal sending unit 130. Finally, one end side and the other end side of the caulking plate 141 are engaged with the base plate 112 of the fluid introduction unit 110 and the connector housing 131 of the signal sending unit 130, respectively, to integrally fix the fluid introduction unit 110, the pressure detection unit 120, and the signal sending unit 130.

[0052] If the pressure sensor 100 does not use the curved or bent flexible connecting wire 132, the assembly process of the pressure sensor 100 requires, for example, stacking from one end to the other end in the direction of the central axis C. This makes it difficult to shorten the assembly time because the degree of freedom in the assembly process is extremely low. However, in this embodiment, the pressure detection unit 120 and the signal transmission unit 130 are connected via the curved or bent flexible connecting wire 132, which increases the degree of freedom in the assembly process of the pressure sensor 100 and thereby shortens the assembly time.

[0053] <Other embodiments> Some other embodiments different from the above-described embodiments will be described with reference to Figures 5(a), (b) and 6. Note that the same reference numerals are used to designate the same components as those in the above-described embodiments, and descriptions thereof will be omitted.

[0054] FIG. 5(a) is a cross-sectional view showing a pressure sensor according to another embodiment of the present invention, and FIG. 5(b) is a cross-sectional view showing a pressure sensor according to yet another embodiment of the present invention. As shown in FIG. 5(a), in this embodiment, the converter substrate 233 is disposed parallel to the central axis C, i.e., parallel to the direction in which the signal sending unit 130 is adjacent to the pressure detection unit 120. The lead-type heat-generating component 233h has a lead 233l bent at a right angle, and its tip is inserted from the mounting surface 233b to the solder surface 233a through a through-hole provided in the converter substrate 233. The through-hole is soldered to connect the connection terminal 134a to the converter substrate 233. A land portion 233n is formed at the connection portion of the converter substrate 233, and is electrically connected to the electrode 135 via a conductive pattern.

[0055] 5(b), in still another embodiment, the conversion board 333 is also arranged in a direction parallel to the direction in which the signal sending unit 130 is adjacent to the pressure detection unit 120. Furthermore, in the lead-type heat-generating component 333h, the lead 333l is bent at a right angle, and the tip thereof is further bent into an L-shape. The tip of this L-shaped lead 333l is soldered onto the mounting surface 333b of the conversion board 333, and a land portion 333n is formed.

[0056] Fig. 6 is a cross-sectional view showing a pressure sensor according to still another embodiment of the present invention. As shown in Fig. 6, in this embodiment, too, conversion substrate 433 is arranged in a direction parallel to the direction in which signal sending unit 130 is adjacent to pressure detection unit 120. Furthermore, lead-type heat-generating component 433h has leads 433l parallel to conversion substrate 433, and a portion of lead 433l is attached to a pattern on mounting surface 433b of conversion substrate 433 with, for example, a conductive adhesive.

[0057] As described above, in another embodiment of the present invention, the conversion substrates 233, 333, and 433 are disposed in the direction in which the signal sending unit 130 is adjacent to the pressure detection unit 120, and therefore the area of ​​the portion facing the adhesive reservoir area 131e is extremely small compared to the conversion substrate 133. As a result, even if the lead-type heat-generating components 233h, 333h, and 433h are inserted into the adhesive reservoir area 131e and the heat-dissipating adhesive 133g spreads while swelling in a direction perpendicular to the direction in which the signal sending unit 130 and the pressure detection unit 120 are adjacent to each other, the heat-dissipating adhesive 133g will not drip onto the conversion substrates 233, 333, and 433. Furthermore, even if the heat-dissipating adhesive 133g creeps up due to surface tension, the heat-dissipating adhesive 133g can be prevented from dripping onto the conversion substrates 233, 333, and 433. Furthermore, even if the heat dissipating adhesive 133g overflows in a direction perpendicular to the direction in which the signal sending section 130 and the pressure detection section 120 are adjacent to each other, the heat dissipating adhesive 133g can be prevented from adhering to the land section 233n or 333n.

[0058] According to the above-described configuration, it is possible to prevent soldering defects that occur when a heat-dissipating adhesive is used to effectively dissipate heat generated in the conversion board to the external environment. [Explanation of symbols]

[0059] 100 Pressure Sensor 110 Fluid introduction section 111 Joint members 112 base plate 120 Pressure detection unit 121 Housing 122 diaphragm 123 Protective Cover 124 Hermetic Glass 124A Liquid sealing chamber 125 Post 126 Semiconductor sensor chip 127 Potential adjustment material 128 lead pin 129 Oil filling pipe 130 Signal sending unit (main body) 131 Connector housing 131a Substrate storage section 131a1 Substrate facing surface 131b Connector connection part 131c Bulkhead 131e Adhesive pool area 131m chamfered section 131w Adhesive pool wall 132 Flexible Wire Connection Material 133 Conversion board 133a One end face 133b Other end face 133f opening 133g heat dissipating adhesive 133h Heat generating parts 133i Insertion Area 133k Notch 133l Lead 133n Land Department 134a connection terminal 134b connection terminal 134c connection terminal 134d One end 134e Other end 134th floor step 135 Electrode 136 Circuit board stopper 140 Connecting member 141 Caulking plate 142 adhesive sheet 151 Thermally radiating resin sheet 152 Thermally radiating adhesive 233 Conversion board 233a Solder surface 233b Mounting surface 233n Land Department 333 conversion board 333a Solder surface 333b Mounting surface 333n Land Department 433 conversion board 433a Solder surface 433b Mounting surface A. Direction of heat dissipation adhesive creeping up C center axis L: Distance between the converter board and the housing in the direction of the central axis S interior space

Claims

1. a pressure detection unit that detects the pressure of the fluid and sends it out; a signal sending unit having a connector housing adjacent to the pressure detection unit, the connector housing defining a board accommodating portion, a connector connection portion, and a partition portion between the board accommodating portion and the connector connection portion, connection terminals for connecting signals to the outside, a conversion board accommodated in the board accommodating portion and adjusting signals to the pressure detection unit via lead pins and to the outside via the connection terminals, and a heat-generating component mounted on the conversion board and fixed to the connector housing with a heat-dissipating adhesive; Equipped with The heat-dissipating adhesive is arranged over an adhesive reservoir area that extends in a direction perpendicular to the direction in which the signal sending section is adjacent to the pressure detection section, and the extended adhesive reservoir area has an area corresponding to the entire bonding range of the heat-generating component with the heat-dissipating adhesive that extends in the direction in which the pressure detection section and the signal sending section are adjacent, and extends in a direction perpendicular to the adjacent direction through the corresponding area, and the connector housing and the conversion board are arranged at a distance from each other.

2. 2. The pressure sensor according to claim 1, wherein the conversion board has a chamfered portion on an outer periphery of the conversion board, and the connector housing has a board anti-rotation member that corresponds to the chamfered portion.

3. 3. The pressure sensor according to claim 1, wherein the conversion substrate has a notch extending to the vicinity of a land portion on the conversion substrate.

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