Sensor Device

Abstract

To supply potential of a mount object to a connector while a board case is made of a synthetic resin.SOLUTION: In a sensor device 10, a board case 56 is formed from a synthetic resin. A sensor case has a metal outer case 53 that is electrically connected to a circuit board 40 and abuts on a casing 21A of a sensor. The circuit board 40 is wired so as to supply potential supplied from the casing 21A of the sensor via the outer case 53 to a connector 41 by a wire L11. Accordingly, while the board case 56 is made of a synthetic resin, potential of a mount object of a sensor device 10 can be supplied to the connector 41. Although the outer case 53 and the circuit board 40 may be connected directly by welding or the like, connection becomes easier by electrically connecting both of them by a connection member 90.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to sensor devices such as diaphragm gauges. [Background technology]

[0002] Patent document 1 discloses a sensor device comprising a sensor section (sensor 2 and heater H) having a metal housing and including a sensor heated by a heater, a sensor case (the lower part of the inner case 42 and the outer case 41) that houses the sensor section, a circuit board (boards 31a to 31c) on which a connector (connector 4p) to which a cable is connected is mounted, and a board case (the upper part of the inner case 42 and the outer case 41) that houses the circuit board. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2007-155500 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the sensor device described in Patent Document 1, if it is necessary to supply the potential (e.g., reference potential) of the mounting target (such as the piping of a semiconductor manufacturing device) to the connector, it is necessary to form the board case and the sensor case from metal and electrically connect the connector to the mounting target via these cases. However, in this case, the entire case is made of metal, which increases the manufacturing cost.

[0005] An object of the present invention is to supply a potential of an attachment object to a connector while making a board case from a synthetic resin. [Means for solving the problem]

[0006] In order to solve the above problems, the sensor device of the present invention is a sensor device that is attached to an attachment target and used, and comprises a sensor section that has a metal casing that is attached to the attachment target and includes a sensor that is heated by a heater, a sensor case that houses the sensor section, a circuit board on which a connector to which a cable is connected is mounted, and a board case that houses the circuit board, wherein the board case is made of synthetic resin, the sensor case has a metal case that is electrically connected to the circuit board and in contact with the casing, and the circuit board is wired to supply a potential supplied from the sensor casing via the metal case to the connector.

[0007] The metal case may be configured to have a shape having a first conduction path that conducts the heat in a first direction, and a second conduction path that conducts the heat in a second direction different from the first direction, so that a heat conduction path from the housing to the electrical connection part with the circuit board is long.

[0008] The metal case may be formed in a mesh shape.

[0009] The electronic device may further include a connection member that electrically connects the metal case and the circuit board, the connection member being connected to the board case. Effect of the Invention

[0010] According to the present invention, the board case is made of synthetic resin, and the potential of the attachment object is supplied to the connector. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a cross-sectional view of a main part of a sensor device according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a perspective view and a partially enlarged view of the sensor device with a part of the board case removed. [Diagram 3] FIG. 3 is an enlarged cross-sectional view of a connection member and the like. [Figure 4] FIG. 4 is a perspective view showing a supply path of the reference potential. [Diagram 5] FIG. 5 is a perspective view of the outer case. [Figure 6] 6(A) to 6(C) are diagrams showing examples of shape patterns of outer cases according to modified examples. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, a sensor device according to an embodiment of the present invention will be described with reference to the drawings. In this embodiment, up, down, left and right directions are set, but the up and down directions do not have to coincide with the top and bottom directions depending on the installation direction of the sensor device.

[0013] As shown in FIG. 1, the sensor device 10 of this embodiment is connected to a pipe H (mounting object) connected to a vacuum chamber T in a semiconductor control device or the like via a joint (not shown), and is configured as a diaphragm vacuum gauge that measures the air pressure of the process gas introduced from the vacuum chamber T to the pipe H.

[0014] The sensor device 10 includes a sensor unit 20, a heat insulating unit 30, a circuit board 40, and a case 50. The sensor device 10 also includes wirings L1 to L3 that electrically connect the sensor unit 20 and the circuit board 40. Note that in Fig. 1, the wirings L1 to L3 are illustrated as an elevational view rather than a cross-sectional view.

[0015] The sensor unit 20 includes a pressure sensor 21, a terminal board 22, a heater 25, a heater support member 26, and a temperature sensor 27.

[0016] The pressure sensor 21 includes a vacuum chamber R1 and an inflow chamber R2 into which the process gas in the pipe H flows in, inside the housing 21A. The housing 21A is made of metal, and its lower portion is configured to be connected to the pipe H via a joint. The pressure sensor 21 detects the air pressure of the process gas. Specifically, the pressure sensor 21 includes a sensor element 21B (schematically drawn as a block in FIG. 1 and the like) disposed at the boundary between the vacuum chamber R1 and the inflow chamber R2, and a conductive pin 21C connected to the sensor element 21B. The sensor element 21B has a diaphragm (diaphragm) that deforms according to the differential pressure between the air pressures of the vacuum chamber R1 and the inflow chamber R2. The sensor element 21B detects the air pressure of the process gas based on the air pressure of the vacuum chamber R1 by outputting an electrical signal indicating a resistance value or an electrostatic capacitance value according to the degree of deformation of the diaphragm. The conductive pin 21C penetrates the housing 21A and transmits the electrical signal output by the sensor element 21B to the outside of the housing 21A.

[0017] The conductive pin 21C is electrically connected to the wiring L1, which is a coaxial cable, via the conductive terminal plate 22. The connection between the terminal plate 22 and the conductive pin 21C and between the terminal plate 22 and the wiring L1 are performed by welding or the like. Note that a cylindrical shield may be provided to surround the conductive pin 21C and connected to the outer conductor of the coaxial cable, so that the signal potential of the conductive pin 21C and the like is not affected by the potential of the metal housing 21A of the pressure sensor 21. Although the number of the conductive pin 21C and the wiring L1 is one in FIG. 1, it may be two or more.

[0018] The heater 25 heats the pressure sensor 21 to prevent the process gas from precipitating within the pressure sensor 21. The heater 25 is a cylindrical band heater (the internal structure is omitted in FIG. 1) and is fastened to a cylindrical heater support member 26. This fastening allows the heater support member 26 to support the heater 25. Power is supplied to the heater 25 from the circuit board 40 via wiring L2. This power supply causes the heater 25 to generate heat. The heater support member 26 has an annular protrusion 26A that protrudes inward. The protrusion 26A engages with a step on the outer periphery of the pressure sensor 21. This engagement allows the heater support member 26, together with the heater 25, to be supported by the pressure sensor 21.

[0019] The temperature sensor 27 is in contact with the pressure sensor 21 and detects the temperature of the pressure sensor 21 heated by the heater 25. The internal structure of the temperature sensor 27 is omitted in Fig. 1. The temperature sensor 27 outputs the detected temperature to the circuit board 40 via the wiring L3.

[0020] The heat insulating section 30 includes a cylindrical heat insulating material 31 surrounding the sensor section 20, and a disk-shaped heat insulating material 32 disposed above the sensor section 20. The heat insulating section 30 as a whole covers the sensor section 20 from above, and insulates against heat from the pressure sensor 21 or the heater 25 so that the heat does not adversely affect the circuit board 40, etc. The heat insulating materials 31 and 32 are made of any material that has a heat insulating effect. The heat insulating material 32 suppresses the heat from the pressure sensor 21, etc. from moving upward.

[0021] The circuit board 40 is configured by assembling a plurality of boards. Circuits (including a microcomputer, etc.) that perform various processes are mounted on the circuit board 40. The circuit board 40 includes a connector 41 to which a cable (not shown) is connected that is used when the sensor device 10 communicates with an external device such as a higher-level device (e.g., a controller for a semiconductor manufacturing device, etc.). The circuit board 40 is configured to supply the potential of the pipe H, to which the sensor device 10 is attached, to the connector 41. Here, the potential of the pipe H will be described as a reference potential. The reference potential supplied to the connector 41 is conducted to a connector that supplies the reference potential to the connector 41, for example.

[0022] The wirings L1 to L3 are connected to the circuit board 40. For example, when the sensor element 21B is a capacitive type, the circuit board 40 applies an AC voltage to the sensor element 21B through one of the wirings L1. Furthermore, the circuit board 40 acquires a voltage signal that changes according to the capacitance value of the capacitor formed by the sensor element 21B through one of the wirings L1. As a result, an electric signal output by the sensor element 21B and taken out by the conductive pin 21C is transmitted through the wiring L1 and supplied to the circuit board 40. The circuit board 40 performs processing based on the acquired electric signal. For example, the circuit board 40 amplifies the electric signal, converts it from analog to digital, etc., and acquires data in a predetermined format that indicates the air pressure of the process gas indicated by the electric signal. The acquired data is output to an external device through a connector 41 and a cable. The circuit board 40 receives the temperature output from the temperature sensor 27 through the wiring L3, and controls the power supplied to the heater 25 through the wiring L2 using the temperature as a feedback value so that the pressure sensor 21 is at a desired temperature (for example, 200°C). As described above, the circuit board 40 controls the sensor section 20 via the wirings L1 to L3.

[0023] The case 50 houses the sensor unit 20, the heat insulating unit 30, the circuit board 40, and the wires L1 to L3. The case 50 includes a sensor case 51 that houses the sensor unit 20 and the heat insulating unit 30, and a board case 56 that houses the circuit board 40.

[0024] The sensor case 51 includes a cylindrical inner case 52 having a thickness in the radial direction as a whole, and a cup-shaped outer case 53 covering the inner case 52 from the outside. The inner case 52 includes an upper inner case 52A having an annular shape with an inverted U-shaped cross section, and a cup-shaped lower inner case 52B having a through hole in the center. The inner case 52 houses a cylindrical heat insulating material 31 inside. The disk-shaped heat insulating material 32 is housed in the upper inner case 52A. The heat insulating material 32 is flexible, and presses the wiring L1 to L3 passing through the upper inner case 52A against the inner peripheral surface 52AA of the upper inner case 52A. The inner case 52 is made of synthetic resin so as not to inhibit the heat insulating effect of the heat insulating material 31. The outer case 53 is made of metal, and the lower part is in contact with the housing 21A of the pressure sensor 21. The outer case 53 will be described in detail later. The sensor case 51 has an overall cup shape with a through hole in the center of the bottom, and the opening at the top is covered with the heat insulating material 32.

[0025] The board case 56 is made of synthetic resin (engineering plastic, super engineering plastic, etc.). The board case 56 covers the sensor case 51 so that the connector 41 can be exposed to the outside. The board case 56 may have a through hole for cooling the circuit board 40.

[0026] Here, the relationship between the circuit board 40, the outer case (metal case) 53, and the board case 56 will be described. As shown in FIG. 2, the sensor device 10 further includes a cylindrical connection member 90 that connects the circuit board 40 and the outer case 53. The connection member 90 includes a cylindrical portion 91 and screws 92 and 93. The fixing portion 56F of the board case 56 (not shown in the enlarged view surrounded by the broken line in FIG. 2) is fixed to the cylindrical portion 91 in a state in which the cylindrical portion 91 penetrates the fixing portion 56F. As a result, the outer case 53 is fixed to the board case 56 together with the inner case 52 and the sensor unit 20 housed in the outer case 53 via the connection member 90, and the circuit board 40 is also fixed. The connection members 90 are arranged at the four corners of the sensor device 10, one each, and the above-mentioned connection and fixing are performed at each of the four corners.

[0027] As shown in FIG. 3, the cylindrical portion 91 has an inner tube 91A made of metal and an outer tube 91B made of synthetic resin. The inner tube 91A and the outer tube 91B are integrally formed by insert molding or the like. The screws 92 and 93 are made of metal. The screw 92 passes through a hole formed in the circuit board 40 and is screwed into the inner tube 91A of the cylindrical portion 91, thereby tightening and fixing the circuit board 40 to the cylindrical portion 91. The screw 93 passes through a cutout formed in the outer case 53 (a portion protruding from the upper end of the cylindrical portion toward the outer periphery) and is screwed into the inner tube 91A of the cylindrical portion 91, thereby tightening and fixing the outer case 53 to the cylindrical portion 91. A wiring L11 (see also FIG. 2) connected to the connector 41 is routed around a portion of the circuit board 40 that contacts the screw 92. The wiring L11 is printed on the circuit board 40 or the like. As described above, the connector 41 is electrically connected to the outer case 53 via the circuit board 40 (the wiring L11) and the connection member 90 (the inner tube 91A, the screw 92, and the screw 93) (FIGS. 2 and 3). As shown in FIG. 1, the outer case 53 is in contact with the metal housing 21A of the pressure sensor 21. As described above, the housing 21A is connected to the pipe H. Therefore, as shown by the bold line in FIG. 4, the reference potential of the pipe H is supplied to the connector 41 via the route of the pipe H → housing 21A → outer case 53 → connection member 90 → circuit board 40 → connector 41.

[0028] As described above, according to this embodiment, the board case 56 is made of synthetic resin to reduce costs, but the sensor case 5 includes a metal outer case 53 electrically connected to the circuit board 40 and in contact with the housing 21A of the pressure sensor 21, and the circuit board 40 is wired by the wiring L11 so as to supply the potential supplied from the housing 21A of the pressure sensor 21 via the outer case 53 to the connector 41. Therefore, while the board case 56 is made of synthetic resin, the potential of the object to which the sensor device 10 is attached (here, the pipe H) can be supplied to the connector 41. Note that the outer case 53 and the circuit board 40 may be directly connected by welding, etc., but it is easier to electrically connect the two using a part such as the connection member 90.

[0029] The outer case 53 contacts the housing 21A of the pressure sensor 21, and as described above, the pressure sensor 21 is heated by the heater 25 (for example, heated to 200° C.). This heating also heats the housing 21A, and the heat of the housing 21A is transferred to the outer case 53. The outer case 53 is made of metal in order to supply the above-mentioned potential to the connector 41, and therefore, depending on its shape, it may be easy to transfer the heat transferred from the housing 21A to the connection member 90, etc. In this embodiment, the outer case 53 is formed in a mesh shape as shown in FIG. 2, thereby lengthening the heat conduction path from the contact portion of the outer case 53 with the housing 21A to the connection member 90 (electrical connection portion with the circuit board 40). Specifically, in order to lengthen the heat conduction path, the outer case 53 is formed in a shape in which the heat conducting portion is bent and branched from a thin rod shape, and in particular, is formed in a shape having a first conduction path M1 that conducts heat in a first direction and a second conduction path M2 that conducts heat in a second direction different from the first direction, as shown in Fig. 5. By lengthening the heat conduction path in this way, the heat is gradually cooled in the process of being transmitted through the outer case 53, and adverse effects (such as deformation) on the connection member 90 and the circuit board 40 and board case 56 connected to the connection member 90 are suppressed.

[0030] The mesh shape may have one or more repetitions of the patterns in Figures 6(A) and (B), for example. This also makes it possible to lengthen the heat conduction path. The outer case 53 may have one or more repetitions of the pattern in Figure 6(C). In this pattern, heat can be conducted in a straight line from below diagonally upward, but depending on the arrangement of the start and end points of the heat conduction path, the heat conduction path can be made longer.

[0031] Furthermore, in the above embodiment, the supply of the reference potential to the connector 41 and the fixing of the outer case 53, the circuit board 40, and the board case 56 to each other are both performed by the connecting member 90, which results in effects such as a reduction in the number of parts of the sensor device 10 and a reduction in costs.

[0032] The above embodiment can be modified in various ways. For example, the shapes of the components described above are arbitrary. The above-described cylinders and disks can be changed to polygonal tubes, polygonal plates, etc. The heater 25 may be provided separately from the sensor device 10 and attached from the outside of the sensor device 10 to heat the pressure sensor 21. The connection destination of the wiring connecting the sensor unit 20 and the circuit board 40 on the sensor unit 20 side can be changed depending on what components the sensor unit 20 has, and is not limited to the above embodiment. The present invention can be applied to sensor devices other than diaphragm vacuum gauges. The sensor device to which the present invention is applied may be a device that measures physical quantities other than pressure.

[0033] Although the present invention has been described above with reference to the embodiment and the modified examples, the present invention is not limited to the above embodiment and the modified examples. For example, the present invention includes various modifications to the above embodiment and the modified examples that can be understood by a person skilled in the art within the scope of the technical idea of ​​the present invention. The configurations listed in the above embodiment and the modified examples can be appropriately combined within a range without contradiction. [Explanation of symbols]

[0034] 10...sensor device, 20...sensor portion, 21...pressure sensor, 21A...housing, 21B...sensor element, 21C...conductive pin, 22...terminal board, 25...heater, 27...temperature sensor, 30...insulating portion, 31...insulating material, 32...insulating material, 40...circuit board, 41...connector, 50...case, 51...sensor case, 52...inner case, 52A...upper inner case, 52B...lower inner case, 53...outer case, 56...board case, 56F...fixing portion, 90...connecting member, 91...cylindrical portion, 91A...inner tube, 91B...outer tube, 92, 93...screw, M1...first conductive path, M2...second conductive path, H...piping.

Claims

1. A sensor device that is attached to an object to be attached, a sensor unit including a sensor that is provided with a metal housing that is attached to the attachment target and is heated by a heater; A sensor case that houses the sensor unit; A circuit board on which a connector to which a cable is connected is mounted; a board case that houses the circuit board, the substrate case is made of synthetic resin, the sensor case includes a metal case electrically connected to the circuit board and in contact with the housing; The circuit board is wired to supply a potential supplied from the housing of the sensor through the metal case to the connector. Sensor device.

2. The metal case is configured to have a shape having a first conduction path that conducts the heat in a first direction and a second conduction path that conducts the heat in a second direction different from the first direction, so that a heat conduction path from the housing to an electrical connection part with the circuit board is long. The sensor device according to claim 1 .

3. The metal case is formed in a mesh shape. The sensor device according to claim 2 .

4. a connecting member electrically connecting the metal case and the circuit board; The connection member is fixed to the board case. The sensor device according to claim 1 .

Images