Sensor device

Abstract

To provide a sensor device that can reduce influences of noise.SOLUTION: A state monitoring sensor 1 includes a sensor part 10 and a cable part 40. The sensor part 10 includes: a thermoelectric element provided on substrates 11 and 12; a first wiring layer 21 provided on one surface of the substrates 11 and 12; and a second wiring layer 22 provided on the other surface of the substrates 11 and 12, and is sealed in an elastic part. The cable part 40 includes signal lines 41 and 42 and a shielding wire 45. At least one of the first wiring layer 21 and the second wiring layer 22 is provided with sensor terminals 211 and 221 connected to the signal line 41 and a ground terminal 213 connected to the shielding wire 45. The ground terminal 213 is connected via a connection part 214 to a cover part 215 that covers an element formation region in which the thermoelectric element is provided.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a sensor device. [Background technology]

[0002] Conventionally, there are known condition detection sensors that detect changes in the heat flow of a measurement object. For example, the condition detection sensor disclosed in Patent Document 1 is made up of a first insulating layer, a first substrate, an intermediate insulating layer, a second substrate, and a second insulating layer stacked together, and outputs a thermoelectromotive force corresponding to the direction and amount of heat flow passing through in the thickness direction as a sensor signal. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-23164 Summary of the Invention [Problem to be solved by the invention]

[0004] For example, in the status detection sensor described in Patent Document 1, noise is sometimes prevented by screwing the shielded wire to the metal body. However, depending on the installation location of the status detection sensor, it may be difficult to screw the shielded wire. In addition, the required length of the shielded wire varies depending on the object to be detected, making it difficult to determine the sensor specifications.

[0005] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a sensor device that can reduce the influence of noise. [Means for solving the problem]

[0006] The sensor device of the present invention includes a sensor unit (10) and a cable unit (40). The sensor unit has a sensor element (111, 112, 121, 122), a first wiring layer (21), and a second wiring layer (22), and is sealed in a sealing unit (50). The sensor element is provided on a substrate (11, 12). The first wiring layer is provided on one surface of the substrate. The second wiring layer is provided on the other surface of the substrate. The cable unit has signal lines (41, 42) and a shielded wire (45).

[0007] At least one of the first wiring layer and the second wiring layer is provided with a sensor terminal (211, 221) connected to a signal line and a ground terminal (213, 223) connected to a shield wire. The ground terminal is connected to a cover portion (215, 225) that covers an element formation region where a sensor element is formed via a connection portion (214, 224). This reduces the influence of noise. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a plan view of a condition monitoring sensor according to a first embodiment. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Figure 5] 1 is an explanatory diagram showing a state in which a condition monitoring sensor according to a first embodiment is arranged in equipment. FIG. [Figure 6] FIG. 10 is a plan view of a condition monitoring sensor according to a second embodiment. [Figure 7] FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. 6. [Figure 8] FIG. 10 is a plan view of a condition monitoring sensor according to a third embodiment. [Figure 9] FIG. 9 is a cross-sectional view taken along line IX-IX in FIG. 8. [Figure 10] 9 is a cross-sectional view taken along line XX in FIG. 8. [Figure 11]FIG. 1A is a plan view of a condition monitoring sensor according to a reference example, and FIG. 1B is an explanatory diagram showing a state in which the condition monitoring sensor according to the reference example is arranged in equipment. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A sensor device according to the present invention will be described below with reference to the accompanying drawings. In the following, substantially identical components in a plurality of embodiments will be designated by the same reference numerals, and the description thereof will be omitted.

[0010] (First embodiment) The first embodiment is shown in Figures 1 to 5. As shown in Figures 1 to 5, a condition monitoring sensor 1 serving as a sensor device includes a sensor section 10, a cable section 40, and an elastic section 50 (see Figure 5). The condition monitoring sensor 1 is a heat flow sensor that converts heat flow into a voltage signal and outputs it.

[0011] The sensor unit 10 has a first substrate 11, a second substrate 12, a first insulating layer 13, a second insulating layer 14, an intermediate insulating layer 15, a first wiring layer 21, a second wiring layer 22, and intermediate wiring layers 251 to 254, and is formed in a generally rectangular shape in a plan view. If the first wiring layer 21 side is the upper side and the second wiring layer 22 side is the lower side, the first wiring layer 21, the intermediate wiring layer 251, the first substrate 11, the intermediate wiring layer 252, the intermediate insulating layer 15, the intermediate wiring layer 253, the second substrate 12, the intermediate wiring layer 254, the second insulating layer 14, and the second wiring layer 22 are stacked in this order from the top.

[0012] The base materials 11 and 12 are made of a thermoplastic resin such as polyimide and have insulating properties. A plurality of through holes 119 and 129 are formed in rows in the base materials 11 and 12. The through holes 119 and 129 are formed in the element formation region A1.

[0013] The through holes 119 of the first substrate 11 are alternately filled with first thermoelectric elements 111 or second thermoelectric elements 112. The through holes 129 of the second substrate 12 are alternately filled with first thermoelectric elements 121 or second thermoelectric elements 122 such that the second thermoelectric elements 122 are located directly below the first thermoelectric elements 111 of the first substrate 11, and the first thermoelectric elements 121 are located directly below the second thermoelectric elements 112 of the first substrate 11.

[0014] The first thermoelectric elements 111, 121 are made of, for example, a sintered alloy of Bi-Sb-Te, which is a P-type semiconductor material. The second thermoelectric elements 112, 122 are made of, for example, a sintered alloy of Bi-Te, which is an N-type semiconductor material. The thermoelectric elements 111, 121, 112, 122 are formed by filling the through holes 119, 129 with a paste of semiconductor material powder and sintering it in a heating and pressurizing process. Adjacent thermoelectric elements 111, 112, 121, 122 are electrically connected by intermediate wiring layers 251-254 provided on both sides of the substrates 11, 12.

[0015] The first wiring layer 21 is provided on the upper surface of the first substrate 11. A first insulating layer 13 is provided between the first wiring layer 21 and an intermediate wiring layer 251 provided on the upper side of the first substrate 11. The second wiring layer 22 is provided on the lower surface of the second substrate 12. A second insulating layer 14 is provided between the second wiring layer 22 and an intermediate wiring layer 254 provided on the lower side of the second substrate 12. The intermediate insulating layer 15 is provided between the intermediate wiring layer 252 formed on the lower side of the first substrate 11 and the intermediate wiring layer 253 formed on the upper side of the second substrate 12.

[0016] The first wiring layer 21 is formed of, for example, gold-plated copper foil, and has a sensor terminal 211, a ground terminal 213, a connection portion 214, and a cover portion 215. The sensor terminal 211 is separated from the ground terminal 213 and the cover portion 215 by etching, and is connected to the thermoelectric elements 111, 112, 121, and 122 via a through-hole 212 that penetrates the first insulating layer 13 and an intermediate wiring layer 251.

[0017] The second wiring layer 22 is formed of, for example, gold-plated copper foil, and has a sensor terminal 221 and a cover portion 225. The sensor terminal 221 is formed below the sensor terminal 211. The sensor terminal 221 is separated from the cover portion 225 by etching, and is connected to the thermoelectric elements 111, 112, 121, and 122 via a through hole 222 and an intermediate wiring layer 254. In this embodiment, the sensor terminal 211 of the first wiring layer 21 is a positive terminal, and the sensor terminal 221 of the second wiring layer 22 is a negative terminal.

[0018] The ground terminal 213 of the first wiring layer 21 is formed adjacent to the sensor terminal 211. The sensor terminal 211 and the ground terminal 213 are separated by etching. The ground terminal 213 is connected to the cover portion 215 via a narrow connection portion 214. In this embodiment, the region where the sensor terminals 211, 221 and the ground terminal 213 are formed is defined as the terminal formation region A2. The terminal formation region A2 is provided on one side of the element formation region A1. Furthermore, in the terminal formation region A2, the base materials 11, 12 are not provided with through holes 119, 129.

[0019] The cover portion 215 is formed so as to cover the entire element formation region A1 on the upper surface side. The cover portion 225 is formed so as to cover the entire element formation region A1 on the lower surface side. Covering the element formation region A1 with the cover portions 215 and 225 prevents oxidation of the thermoelectric elements 111, 112, 121, 122, etc.

[0020] The cable section 40 is, for example, a two-core shielded wire, and has signal wires 41 and 42 each covered with a coating, with one end taken out from the wiring outer coating 47. The coating of the + side signal wire 41 is stripped off at the tip on the sensor section 10 side, and it is connected to the sensor terminal 211 with solder H or the like. The coating of the - side signal wire 42 is stripped off at the tip on the sensor section 10 side, and it is connected to the sensor terminal 221 with solder H or the like.

[0021] The shield wire 45 is formed in a mesh shape inside the wiring outer sheath 47. The shield wire 45 is taken out from the wiring outer sheath 47 on the sensor unit 10 side, twisted into a wire shape, and connected to the earth terminal 213 with solder H or the like. The ends of the signal lines 41, 42 and the shield wire 45 opposite the sensor unit 10 are provided so as to be connectable to the measuring instrument 105.

[0022] 2 is a cross section taken along line II-II in Fig. 1, and strictly speaking, the solder H does not appear in the cross section, but the solder H and the signal line are shown to explain the connection between the signal line and the terminal. Similarly, in Fig. 3, Fig. 4, and cross sections according to embodiments described later, the connection between the terminal and the signal line or shielded line is shown for the sake of explanation.

[0023] As shown in Fig. 5, the condition monitoring sensor 1 has a sensor unit 10 molded into an elastic unit 50, and is installed in a gap between equipment or a jig with the elastic unit 50 slightly compressed in the thickness direction. The elastic unit 50 is made of a resin with a high thermoelastic coefficient, such as UPE (ultra-high molecular weight polyethylene), and generates or absorbs heat through elastic deformation. In the example of Fig. 5, the condition monitoring sensor 1 is installed in a gap 101 between equipment 100.

[0024] When distortion occurs in the structure of the equipment 100, the elastic part 50 of the condition monitoring sensor 1 compresses or expands, generating or absorbing heat due to the thermoelastic effect. The heat flow generated at this time is detected by the sensor part 10, which is a heat flow sensor, and converted into a voltage signal. The condition monitoring sensor 1 outputs a voltage signal of several μV in response to distortion of, for example, 0.1 μm or less. This makes it possible to detect abnormalities in the equipment condition or long-term changes such as the end of machine life by capturing the condition of the equipment 100 during operation from slight deformations in the structure.

[0025] Due to the characteristics of the heat flow sensor, the condition monitoring sensor 1 is susceptible to radio wave noise from the device it is attached to, so noise countermeasures are necessary. The noise that affects the condition monitoring sensor 1 includes radio waves such as Wi-Fi, electromagnetic noise generated by motors inside or nearby the equipment 100, power supply noise, etc., making it difficult to identify the source of the noise.

[0026] Fig. 11(a) shows a condition monitoring sensor 9 of a reference example, and as shown in Fig. 11(b), the shielded wire 49 is fixed to the metal housing of the equipment 100 with a metal screw 102. In the reference example, noise countermeasures are implemented by canceling out the potential difference between the metal housing of the equipment 100 and the measuring instrument 105 in a hardware manner.

[0027] Attaching the shielded wire 49 to a location close to the processing point is likely to produce a noise reduction effect. However, attaching the screw 102 near an important processing point in the equipment 100 may cause the equipment 100 to shift, potentially affecting the product. This makes it difficult to connect the shielded wire 49 to the equipment 100. Furthermore, the optimal length of the shielded wire 49 varies depending on the equipment in which the condition monitoring sensor 9 is installed, making it difficult to determine a single sensor specification.

[0028] Therefore, in this embodiment, it is assumed that the potential difference between the equipment 100 and the measuring instrument 105 is equal to the potential difference between the condition monitoring sensor 1 clamped to the equipment 100 and the measuring instrument 105, and noise countermeasures are implemented by connecting the shielded wire 45 to the metal body of the condition monitoring sensor 1.

[0029] Specifically, the cover 215 provided above the element formation region A1 is used for noise cancellation. The cover 215 and the ground terminal 213 are electrically connected by the connection 214, and radio noise passes through the cover 215, the connection 214, the ground terminal 213, and the shield wire 45 to the ground, thereby reducing the noise.

[0030] The connection part 214 is formed to be narrower than the ground terminal 213. The connection part 214 only needs to have a width approximately equal to the diameter of the shielded wire 45, and in this embodiment, the width is approximately ⅕ of the ground terminal 213. By making the connection part 214 narrow, heat received by the ground terminal 213 is less likely to flow toward the cover part 215. Furthermore, by making the connection part 214 narrow, it is possible to prevent the tensile stress on the shielded wire 45 from being applied to the thermoelectric elements 111, 112, 121, and 122.

[0031] As described above, the condition monitoring sensor 1 includes the sensor unit 10 and the cable unit 40. The sensor unit 10 has thermoelectric elements 111, 112, 121, 122 provided in the through holes 119, 129 of the substrates 11, 12, a first wiring layer 21 provided on one surface of the laminated substrates 11, 12, and a second wiring layer 22 provided on the other surface of the laminated substrates 11, 12, and is sealed in the elastic unit 50. The cable unit 40 has signal lines 41, 42 and a shielded wire 45.

[0032] At least one of the first wiring layer 21 and the second wiring layer 22 has sensor terminals 211 and 221 connected to the signal lines 41 and 42, and a ground terminal 213 connected to the shielded wire 45. In this embodiment, the sensor terminals 211 and 221 are formed on the first wiring layer 21 and the second wiring layer 22, and the ground terminal 213 is formed on the first wiring layer 21.

[0033] The sensor terminals 211 and 221 are separated from the cover parts 215 and 225 that cover the element formation area A1 in which the thermoelectric elements 111, 112, 121, and 122 are formed, and are electrically connected to the thermoelectric elements 111, 112, 121, and 122. The ground terminal 213 is separated from the sensor terminal 211, and is connected via a connection part 214 to the cover part 215 that covers the element formation area A1.

[0034] In this embodiment, the cover portion 215 formed in the element formation area A1 is used as a radio wave absorbing portion, and radio wave noise is grounded via the earth terminal 213 and the shield wire 45, thereby reducing the effects of radio wave noise.

[0035] The connection part 214 is formed to be narrower than the ground terminal 213. This makes it possible to prevent the heat received by the ground terminal 213 from being transferred to the cover part 215. In addition, it is possible to prevent the stress applied to the shield wire 45 from being applied to the thermoelectric elements 111, 112, 121, and 122.

[0036] (Second embodiment) A second embodiment is shown in Figures 6 and 7. The second wiring layer 22 of the condition monitoring sensor 2 of this embodiment is formed in substantially the same manner as the first wiring layer 21, and includes a sensor terminal 221 (not shown in Figures 6 and 7), a ground terminal 223, a connection portion 224, and a cover portion 225. In this embodiment, the tip of the shielded wire 45 is branched into two, one of which is connected to the ground terminal 213 of the first wiring layer 21, and the other is connected to the ground terminal 223 of the second wiring layer 22. Connecting the shielded wire 45 to both the front and back surfaces of the sensor unit 10 can further reduce noise.

[0037] In this embodiment, the ground terminals 213, 223 are provided on the first wiring layer 21 and the second wiring layer 22. The tip of the shielded wire 45 is branched into two, one of which is connected to the ground terminal 213 on the first wiring layer 21 and the other of which is connected to the ground terminal 223 on the second wiring layer 22. This allows radio wave noise from both sides to be grounded, further improving noise reduction performance. In addition, the same effects as those of the above embodiment are achieved.

[0038] (Third embodiment) 8 to 10 show a third embodiment. In a condition monitoring sensor 3 of this embodiment, the first wiring layer 21 has a sensor terminal 211, a ground terminal 213, a connection portion 214, and a cover portion 215. The second wiring layer 22 has a sensor terminal 221 (not shown in FIGS. 8 to 10) and a cover portion 225.

[0039] In this embodiment, if the region where the ground terminal 213 is formed is defined as a ground terminal region A3, the ground pattern 255 provided in the ground terminal region A3 in the intermediate wiring layers 251 to 254 is separated from the element forming region A1 and the sensor terminals 211, 221.

[0040] The ground terminal 213 has a through hole 216 formed therein that penetrates the first insulating layer 13 and is connected to the ground pattern 255. Conductive elements 115 and 125 are provided on the substrates 11 and 12 directly below the ground terminal 213. The conductive elements 115 and 125 are electrically connected via the ground pattern 255 and the through hole 256. As a result, the cover portion 225 of the second wiring layer 22 is electrically connected to the ground terminal 213 via the conductive elements 115 and 125, etc.

[0041] The conductive elements 115 and 125 are formed by filling through holes provided in the base materials 11 and 12 with a paste material such as stainless steel powder and sintering the material. The manufacturing process for the conductive elements 115 and 125 is the same as that for the thermoelectric elements, and in this embodiment, the conductive elements 115 and 125 are formed simultaneously with the first thermoelectric elements 111 and 121.

[0042] Note that conductive elements 115, 125 may be made of the same material as the thermoelectric elements as long as they are conductive. In this case, when filling the thermoelectric elements, the through-holes formed directly below ground terminal 213 may also be filled with the same material as the thermoelectric elements.

[0043] The shielded wire 45 is connected to the ground terminal 213. In this embodiment, similar to the above-described embodiment, the ground terminal 213 is electrically connected to the cover portion 215 via the connection portion 214. The ground terminal 213 is also electrically connected to the lower cover portion 225 via the conductive elements 115, 125, etc. This allows noise from both sides of the sensor portion 10 to be grounded using a single shielded wire 45.

[0044] In this embodiment, the ground terminal 213 is provided on the first wiring layer 21 and is electrically connected to the cover portion 225 of the second wiring layer 22 via the conductive elements 115, 125 and through holes 216, 226, 256 provided on the substrates 11, 12. This allows the sensor unit 10 and the shielded wire 45 to be connected at a single point, so that radio noise from both sides can be grounded. This also provides the same effects as the above embodiment.

[0045] In the embodiment, the condition monitoring sensors 1 to 3 correspond to the "sensor device", the first substrate 11 and the second substrate 12 correspond to the "substrate", the thermoelectric elements 111, 112, 121, and 122 correspond to the "sensor element", and the elastic portion 50 corresponds to the "sealing portion".

[0046] (Other embodiments) In the above embodiment, two base materials are stacked. In other embodiments, the number of base material layers may be one or three or more. In the above embodiment, a + terminal is provided on the first wiring layer and a - terminal is provided on the second wiring layer as the sensor terminal. In other embodiments, the sensor terminal may be provided on either the first wiring layer or the second wiring layer. In addition, the configuration of the condition monitoring sensor may differ from that of the above embodiment. As described above, the present invention is not limited to the above embodiment and can be embodied in various forms without departing from the spirit of the invention. [Explanation of symbols]

[0047] 1 to 3: Condition monitoring sensor (sensor device) 10. Sensor section 11...First base material (base material) 12...Second base material (base material) 111, 112, 121, 122... Thermoelectric element (sensor element) 21...1st wiring layer 22...2nd wiring layer 211, 221: Sensor terminals 213, 223: Ground terminals 214, 224...Connection part 215, 225...Cover part 40 Cable section 41, 42: Signal wire 45: Shield wire 50 Elastic part (sealing part)

Claims

1. a sensor section (10) having a sensor element (111, 112, 121, 122) provided on a substrate (11, 12), a first wiring layer (11) provided on one surface of the substrate, and a second wiring layer (12) provided on the other surface of the substrate, and sealed in a sealing section (50); a cable portion (40) having signal lines (41, 42) and a shielded line (45); Equipped with At least one of the first wiring layer and the second wiring layer is provided with a sensor terminal (211, 221) connected to the signal line and a ground terminal (213, 223) connected to the shield line, The ground terminal is connected to a cover portion (215, 225) that covers an element formation area where the sensor element is provided, via a connection portion (214, 224).

2. the ground terminal is provided in the first wiring layer and the second wiring layer, 2. The sensor device according to claim 1, wherein the shield wire has a tip that branches into two, one of which is connected to the ground terminal of the first wiring layer and the other of which is connected to the ground terminal of the second wiring layer.

3. The sensor device of claim 1, wherein the earth terminal is provided on the first wiring layer and is electrically connected to the cover portion of the second wiring layer via a conductive element (115, 125) and a through hole (216, 226) provided on the substrate.

4. 4. The sensor device according to claim 1, wherein the connection portion is formed to be narrower than the ground terminal.

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