Sensor

Abstract

To provide a sensor capable of improving detection performance.SOLUTION: A sensor includes a first sensor portion. The first sensor portion includes an insulating member, a first element portion, and a second element portion. The first element portion includes: a first resistance element including a first resistance end portion and a first other resistance end portion, covered with the insulating member; a first electrode electrically connected to the first resistance end portion, and not covered with the insulating member; and a first other electrode electrically connected to the first other resistance end portion, and not covered with the insulating member. The second element portion includes: a second resistance element including a second resistance end portion and a second other resistance end portion, and covered with the insulating member; a second electrode electrically connected to the second resistance end portion, and not covered with the insulating member; and a second other electrode electrically connected to the second other resistance end portion, and not covered with the insulating member. A second distance between the second electrode and the second other electrode is shorter than a first distance between the first electrode and the first other electrode.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] Embodiments of the present invention relate to sensors.

Background Art

[0002] For example, in sensors, improvement in detection performance is desired.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Embodiments of the present invention provide a sensor capable of improving detection performance.

Means for Solving the Problems

[0005] According to an embodiment of the present invention, a sensor includes a first sensor unit. The first sensor unit includes an insulating member, a first element unit, and a second element unit. The first element unit includes a first resistance element covered with the insulating member and including a first resistance end portion and a first other resistance end portion, a first electrode electrically connected to the first resistance end portion and not covered with the insulating member, and a first other electrode electrically connected to the first other resistance end portion and not covered with the insulating member. The second element unit includes a second resistance element covered with the insulating member and including a second resistance end portion and a second other resistance end portion, a second electrode electrically connected to the second resistance end portion and not covered with the insulating member, and a second other electrode electrically connected to the second other resistance end portion and not covered with the insulating member. A second distance between the second electrode and the second other electrode is shorter than a first distance between the first electrode and the first other electrode.

Brief Description of the Drawings

[0006] [Figure 1]Figure 1 is a schematic plan view illustrating a sensor according to the first embodiment. [Figure 2] Figures 2(a) to 2(f) are schematic cross-sectional views illustrating the sensor according to the first embodiment. [Figure 3] Figures 3(a) and 3(b) are graphs illustrating the experimental results. [Figure 4] Figures 4(a) and 4(b) are schematic diagrams illustrating the simulation results. [Figure 5] Figures 5(a) and 5(b) are schematic plan views illustrating the sensor according to the first embodiment. [Figure 6] Figures 6(a) and 6(b) are schematic cross-sectional views illustrating a sensor according to the second embodiment. [Figure 7] Figure 7 is a schematic plan view illustrating a sensor according to the third embodiment. [Figure 8] Figure 8 is a schematic cross-sectional view illustrating a part of the sensor according to the third embodiment. [Figure 9] Figure 9 is a schematic plan view illustrating one of several operations in the sensor according to the third embodiment. [Figure 10] Figure 10 is a schematic plan view illustrating one of several operations in the sensor according to the third embodiment. [Figure 11] Figure 11 is a schematic plan view illustrating a sensor according to the third embodiment. [Figure 12] Figure 12 is a block diagram illustrating a sensor according to the third embodiment. [Figure 13] Figure 13 is a schematic cross-sectional view illustrating a sensor according to an embodiment. [Modes for carrying out the invention]

[0007] The embodiments of the present invention will be described below with reference to the drawings. Drawings are schematic or conceptual, and the relationships between the thickness and width of each part, as well as the ratios of the sizes of different parts, are not necessarily identical to those of reality. Even when representing the same part, the dimensions and ratios may be depicted differently in different drawings. In this specification and in each figure, elements similar to those described above are denoted by the same reference numerals with respect to previously shown figures, and detailed explanations are omitted as appropriate.

[0008] (First Embodiment) Figure 1 is a schematic plan view illustrating a sensor according to the first embodiment. Figures 2(a) to 2(f) are schematic cross-sectional views illustrating the sensor according to the first embodiment. Figure 2(a) is a cross-sectional view of Figure 1 taken along the line A1-A2. Figure 2(b) is a cross-sectional view of Figure 1 taken along the line A3-A4. Figure 2(c) is a cross-sectional view of Figure 1 taken along the line A5-A6. Figure 2(d) is a cross-sectional view of Figure 1 taken along the line B1-B2. Figure 2(e) is a cross-sectional view of Figure 1 taken along the line B3-B4. Figure 2(f) is a cross-sectional view of Figure 1 taken along the line B5-B6.

[0009] As shown in Figure 1, the sensor 110 according to this embodiment includes a first sensor section 10A. The first sensor section 10A includes an insulating member 41, a first element section 21D, and a second element section 22D.

[0010] As shown in Figures 2(a) to 2(f), the insulating member 41 may include, for example, a substrate 41s and an insulating layer 41L. A portion of the substrate 41s may include a semiconductor layer such as a silicon substrate. For example, an insulating layer may be provided on the surface of a silicon substrate, and various conductive layers may be provided thereon. The insulating layer 41L may be provided on these conductive layers. In Figure 1, the insulating layer 41L is omitted.

[0011] As shown in Figure 1, the first element portion 21D includes a first resistive element 21, a first electrode 21U, and a first other electrode 21V. The first resistive element 21 includes a first resistive end 21e and a first other resistive end 21f. As shown in Figure 2(c), the first resistive element 21 is covered by an insulating member 41.

[0012] As shown in FIG. 1, the first electrode 21U is electrically connected to the first resistance end portion 21e. As shown in FIG. 2(a), the first electrode 21U is not covered by the insulating member 41.

[0013] As shown in FIG. 1, the first other electrode 21V is electrically connected to the first other resistance end portion 21f. As shown in FIG. 2(b), the first other electrode 21V is not covered by the insulating member 41.

[0014] In this example, the first sensor unit 10A includes the first electrode wiring 21La and the first other electrode wiring 21Lb. The first electrode wiring 21La electrically connects the first resistance end portion 21e to the first electrode 21U. In this example, the first electrode wiring 21La is electrically connected to the first resistance end portion 21e via the via 21va. The first other electrode wiring 21Lb electrically connects the first other resistance end portion 21f to the first other electrode 21V. In this example, the first other electrode wiring 21Lb is electrically connected to the first other resistance end portion 21f via the via 21vb.

[0015] As shown in FIG. 1, the second element unit 22D includes the second resistance element 22, the second electrode 22U, and the second other electrode 22V. The second resistance element 22 includes the second resistance end portion 22e and the second other resistance end portion 22f. As shown in FIG. 2(f), the second resistance element 22 is covered by the insulating member 41. <000009​​​​​​​​​In this example, the first sensor unit 10A includes a second electrode wiring 22La and a second other electrode wiring 22Lb. The second electrode wiring 22La electrically connects the second resistor end 22e to the second electrode 22U. In this example, the second electrode wiring 22La is electrically connected to the second resistor end 22e via a via 22va. The second other electrode wiring 22Lb electrically connects the second other resistor end 22f to the second other electrode 22V. In this example, the second other electrode wiring 22Lb is electrically connected to the second other resistor end 22f via a via 22vb.

[0019] At least one of the first electrode wiring 21La, the first other electrode wiring 21Lb, the second electrode wiring 22La, and the second other electrode wiring 22Lb is a low-resistance wiring. For example, at least one of the first electrode wiring 21La, the first other electrode wiring 21Lb, the second electrode wiring 22La, and the second other electrode wiring 22Lb contains Al.

[0020] As shown in Figure 1, in this embodiment, the distance between the first electrode 21U and the first other electrode 21V is defined as the first distance L1. The distance between the second electrode 22U and the second other electrode 22V is defined as the second distance L2. The second distance L2 is shorter than the first distance L1.

[0021] As shown in Figure 1, for example, the parasitic resistance between the first electrode 21U and the first other electrode 21V is denoted as the first parasitic resistance H1. The first electrical resistance Rp1 between the first electrode 21U and the first other electrode 21V corresponds to the resistance of the parallel circuit including the first parasitic resistance H1 and the electrical resistance R1 of the first resistive element 21.

[0022] The parasitic resistance between the second electrode 22U and the second other electrode 22V is denoted as the second parasitic resistance H2. The second electrical resistance Rp2 between the second electrode 22U and the second other electrode 21V corresponds to the resistance of the parallel circuit including the second parasitic resistance H2 and the electrical resistance R2 of the second resistive element 22.

[0023] The second parasitic resistance H2 is affected, for example, by water adhering to the surface in the region between the second electrode 22U and the second other electrode 22V. For example, the second parasitic resistance H2 changes in accordance with changes in humidity in the space around the first sensor unit 10A. When humidity is high, the parasitic resistance is low. When humidity is low, the parasitic resistance is high. Therefore, the second electrical resistance Rp2 (parallel resistance) between the second electrode 22U and the second other electrode 22V changes in accordance with changes in humidity in the space around the first sensor unit 10A.

[0024] On the other hand, the first electrical resistance Rp1 (parallel resistance) between the first electrode 21U and the first other electrode 21V does not substantially change in response to changes in humidity. Or, the first rate of change of the first electrical resistance Rp1 with respect to changes in humidity is lower than the second rate of change of the second electrical resistance Rp2 with respect to changes in humidity. The first electrical resistance Rp1 (parallel resistance) is substantially the same as, for example, the electrical resistance R2 of the second resistive element 22.

[0025] For example, humidity can be detected with high accuracy by detecting the difference between a first electrical resistance Rp1 and a second electrical resistance Rp2. According to the embodiment, a sensor capable of improving detection performance can be provided. For example, differential detection cancels out the temperature dependence of electrical resistances R1 and R2. For example, a sensor whose characteristics change depending on changes in humidity can be provided.

[0026] As shown in Figures 2(a) to 2(f), the substrate 41s extends along the XY plane. The direction from the substrate 41s to the first electrode 21U is along the Z-axis direction. The Z-axis direction is perpendicular to the X-axis and Y-axis directions. The Y-axis direction is perpendicular to the X-axis direction.

[0027] As shown in Figure 1, the sensor 110 may include a control unit 70. The control unit 70 includes, for example, a first supply circuit 78a, a second supply circuit 78b, and a differential circuit 71. The first supply circuit 78a supplies a first current to the first resistive element 21 via a first electrode 21U and a first other electrode 21V. The second supply circuit 78b supplies a second current to the second resistive element 22 via a second electrode 22U and a second other electrode 22V. The first supply circuit 78a and the second supply circuit 78b are, for example, constant current sources.

[0028] The differential circuit 71 includes a first input section 71a, a second input section 71b, and an output section 71o. The first input section 71a receives a first voltage v1 between the first electrode 21U and the first other electrode 21V. The second input section 71b receives a second voltage v2 between the second electrode 22U and the second other electrode 22V. The output section 71o outputs a first signal Sg1 corresponding to the difference between the first voltage v1 and the second voltage v2.

[0029] The first signal Sg1 contains information about humidity. For example, when the absolute value of the first signal Sg1 is large, the humidity is higher than when the absolute value of the first signal Sg1 is small.

[0030] For example, the electrical resistance R1 of the first resistive element 21 can be substantially the same as the electrical resistance R2 of the second resistive element 22. For instance, the electrical resistance R1 of the first resistive element 21 is between 0.9 and 1.1 times the electrical resistance R2 of the second resistive element 22. Because these electrical resistances are substantially the same, the component corresponding to humidity in the first signal Sg1 becomes larger, allowing for higher accuracy in humidity detection.

[0031] As shown in Figures 2(a), 2(b), 2(d), and 2(e), the first electrode wiring 21La, the first other electrode wiring 21Lb, the second electrode wiring 22La, and the second other electrode wiring 22Lb may be covered with an insulating member 41.

[0032] The first resistive element 21 may be formed from, for example, at least one of conductive layers 26a, 27a, 26b, and 27b (see Figures 2(a) and 2(b)). The second resistive element 22 may be formed from, for example, at least one of conductive layers 28a, 29a, 28b, and 29b (see Figures 2(d) and 2(e)). For example, at least one of the first resistive element 21 and the second resistive element 22 contains TiN. It is easy to obtain a resistance of an appropriate value.

[0033] In one example, at least one of the first electrode 21U, the first other electrode 21V, the second electrode 22U, and the second other electrode 22V includes at least one selected from the group consisting of Pd, Au, Pt, and Al. For example, at least one surface portion of the first electrode 21U, the first other electrode 21V, the second electrode 22U, and the second other electrode 22V includes at least one selected from the group consisting of Pd, Au, Pt, and Al. Corrosion and the like can be suppressed in these electrodes that are exposed to the outside. For example, stable characteristics can be easily obtained. These electrodes are, for example, electrode pads.

[0034] The insulating member 41 includes, for example, at least one selected from the group consisting of oxygen and nitrogen, and silicon. The insulating member 41 includes, for example, at least one of silicon nitride, silicon oxide, and silicon oxynitride.

[0035] The following describes examples of experimental results obtained by the inventor. In the experiment, a capacitive element consisting of two electrodes, two electrodes connected to those electrodes, and a substrate are placed on it. The impedance between the two electrodes is measured by changing the humidity of the surrounding environment.

[0036] Figures 3(a) and 3(b) are graphs illustrating the experimental results. In Figure 3(a), the horizontal axis represents the real component of impedance, "Real Z," and the vertical axis represents the imaginary component of impedance, "Imag Z." As shown in Figure 3(a), when the humidity is 30%RH, the real component "Real Z" is virtually zero. In this case, the impedance between the two electrodes consists only of the capacitive component. On the other hand, when the humidity is 90%RH, a real component "Real Z" is generated. In this case, the impedance between the two electrodes is the impedance of a parallel circuit of capacitive and resistive components.

[0037] In Figure 3(b), the horizontal axis represents the frequency fm1 in impedance measurement. The vertical axis represents the parallel resistance component Rpr. When the humidity is 30%RH, the parallel resistance component Rpr is high. On the other hand, when the humidity is 90%RH, the parallel resistance component Rpr decreases.

[0038] Thus, the resistance component between the two electrodes changes depending on the humidity. This characteristic can be used to detect humidity.

[0039] The following describes an example of simulation results regarding the electrical resistance R2 of the second resistive element 22 and the second parasitic resistance H2 between the second electrode 22U and the second other electrode 22V.

[0040] Figures 4(a) and 4(b) are schematic diagrams illustrating the simulation results. Figure 4(a) illustrates a simulation model. Figure 4(b) illustrates the simulation results. As shown in Figure 4(a), in the simulation model, the electrical resistance R2 of the second resistive element 22 and the second parasitic resistance H2 between the second electrode 22U and the second other electrode 22V are connected in parallel. The equivalent resistance of the parallel circuit is denoted as resistance Rx.

[0041] In Figure 4(b), the horizontal axis represents the second parasitic resistance H2 between the second electrode 22U and the second other electrode 22V. The vertical axis represents the resistance change ΔR. The resistance change ΔR is the difference between the electrical resistance R2 and the resistance Rx. As shown in Figure 4(b), when the electrical resistance R2 of the second resistive element 22 is low, at 100Ω, the resistance change ΔR is virtually zero even if the second parasitic resistance H2 changes. When the electrical resistance R2 of the second resistive element 22 becomes high, at 2kΩ or 4kΩ, the resistance change ΔR changes in accordance with the change in the second parasitic resistance H2. As already explained, the second parasitic resistance H2 changes depending on the humidity.

[0042] In this embodiment, the electrical resistance R2 of the second resistive element 22 is preferably, for example, 1 kΩ or more and 20 kΩ or less. This makes it easier to detect changes in humidity appropriately and with high accuracy. As already described, it is preferable that the electrical resistance R1 of the first resistive element 21 is substantially the same as the electrical resistance R2. Therefore, it is preferable that the electrical resistance R1 of the first resistive element 21 is 1 kΩ or more and 20 kΩ or less.

[0043] As explained below, the second electrode 22U and the second other electrode 22V may be comb-shaped electrodes.

[0044] Figures 5(a) and 5(b) are schematic plan views illustrating the sensor according to the first embodiment. As shown in Figures 5(a) and 5(b), the second electrode 22U includes a second electrode base 22Ap and a plurality of second electrode protrusions 22Aq. The plurality of second electrode protrusions 22Aq are electrically connected to the second electrode base 22Ap. At least a portion of the second other electrode 22V lies between one of the plurality of second electrode protrusions 22Aq and another of the plurality of second electrode protrusions 22Aq.

[0045] In these examples, the second other electrode 22V includes a second other electrode base 22Bp and a plurality of second other electrode protrusions 22Bq. The plurality of second other electrode protrusions 22Bq are electrically connected to the second other electrode base 22Bp. One of the plurality of second electrode protrusions 22Aq lies between one of the plurality of second other electrode protrusions 22Bq and another of the plurality of second other electrode protrusions 22Bq.

[0046] Due to the comb-shaped electrodes, the second parasitic resistance H2 between the second electrode 22U and the second other electrode 22V is more susceptible to changes in humidity. Due to the comb-shaped electrodes, the second electrical resistance Rp2 (parallel resistance) between the second electrode 22U and the second other electrode 22V is more susceptible to changes in humidity.

[0047] (Second Embodiment) The sensor according to the second embodiment also includes a first sensor section 10A (see Figure 1). In the second embodiment as well, the first sensor section 10A includes an insulating member 41, a first element section 21D, and a second element section 22D (see Figure 1). In the second embodiment as well, the first element section 21D includes a first resistive element 21, a first electrode 21U, and a first other electrode 21V (see Figure 1). In the second embodiment as well, the second element section 22D includes a second resistive element 22, a second electrode 22U, and a second other electrode 22V (see Figure 1). In the second embodiment, the characteristics in the region between the second electrode 22U and the second other electrode 22V are different from the characteristics in the region between the first electrode 21U and the first other electrode 21V. Examples of the characteristics between these electrodes will be described below for the second embodiment.

[0048] Figures 6(a) and 6(b) are schematic cross-sectional views illustrating a sensor according to the second embodiment. As shown in Figure 6(a), in the sensor 120, the insulating member 41 includes a first insulating region 45a between the first electrode 21U and the first other electrode 21V. As shown in Figure 6(b), the insulating member 41 includes a second insulating region 45b between the second electrode 22U and the second other electrode 22V.

[0049] The insulating member 41 has a first insulating region 45a made of a first material and a first contact angle of the first insulating region 45a with respect to water. The insulating member 41 also has at least one of the following: a second insulating region 45b made of a second material and a second contact angle of the second insulating region 45b with respect to water. The second material is different from the first material. The second contact angle is smaller than the first contact angle. At least a part of the configuration of the sensor 120, excluding this, may be the same as the configuration of the sensor 110.

[0050] For example, the first insulating region 45a includes the first material. The second insulating region 45b includes the second material, which is different from the first material. For example, the contact angle of the second insulating region 45b with respect to water is smaller than the contact angle of the first insulating region 45a with respect to water.

[0051] Thus, the first insulating region 45a and the second insulating region 45b have different material and surface properties. As a result, the electrical resistance between these electrodes changes depending on the humidity. Humidity can be detected by detecting the change in the value (e.g., voltage) corresponding to the electrical resistance between these electrodes.

[0052] In the second embodiment, the first distance L1 between the first electrode 21U and the first other electrode 21V may be different from or the same as the second distance L2 (see Figure 1) between the second electrode 22U and the second other electrode 22V.

[0053] In the sensor 120, for example, the contact angle of the second material with respect to water is smaller than the contact angle of the first material with respect to water. The first material has, for example, high hydrophobicity (e.g., water repellency). The second material has, for example, high hydrophilicity. The first material may contain at least one of fluorine and an alkyl group. The alkyl group may, for example, include a methyl group. The first material may contain, for example, polydimethylsiloxane (PDMS).

[0054] The difference in characteristics between the first insulating region 45a and the second insulating region 45b may be provided by a difference in surface treatment. For example, hydrophilicity can be increased by irradiation with electromagnetic waves such as ultraviolet light. For example, hydrophilicity can be increased by treatment with particles. For example, the contact angle can be changed by treatment with a surface modifier (e.g., a silane coupling agent). This makes it possible to obtain a difference in the change of parasitic resistance in response to changes in humidity.

[0055] (Third embodiment) Figure 7 is a schematic plan view illustrating a sensor according to the third embodiment. Figure 8 is a schematic cross-sectional view illustrating a part of the sensor according to the third embodiment. As shown in Figure 7, the sensor 130 according to this embodiment further includes a second sensor section 10B in addition to the first sensor section 10A. In sensor 130, the configuration of the first sensor section 10A may be the same as the configuration of the first sensor section 10A in sensor 110 or sensor 120.

[0056] As shown in Figure 8, the second sensor unit 10B includes a base 41B, a fixed electrode 35, a support portion 33, and a movable electrode 31. The fixed electrode 35 is fixed to the base 41B. The support portion 33 is fixed to the base 41B. The movable electrode 31 is supported by the support portion 33. A first gap g1 is provided between the fixed electrode 35 and the movable electrode 31.

[0057] The base 41B may be continuous with the substrate 41s. The base 41B may also be provided separately from the substrate 41s.

[0058] In this example, the second sensor unit 10B further includes a connection unit 32. The connection unit 32 is supported by a support unit 33. The connection unit 32 supports the movable electrode 31.

[0059] The first value corresponding to the capacitance between the fixed electrode 35 and the movable electrode 31 changes depending on the substance to be detected contained in the space around the second sensor unit 10B. The substance to be detected is, for example, hydrogen.

[0060] For example, the connection portion 32 can be deformed according to the concentration of the substance to be detected contained in the space. For example, a substance adsorption layer 32L is provided on the connection portion 32. The substance adsorption layer 32L expands according to the degree of substance adsorption. The connection portion 32 deforms due to the deformation of the substance adsorption layer 32L. The distance between the movable electrode 31 and the fixed electrode 35 changes according to the deformation of the connection portion 32. The concentration of the substance to be detected can be detected by measuring the capacitance corresponding to the change in distance.

[0061] As shown in Figure 8, the connection portion 32 may include a heater 32H. The connection portion 32 is locally heated by the heater 32H. This allows moisture adsorbed on the material adsorption layer 32L (e.g., a gas-sensitive film) to be released. For example, oxygen adsorbed on the material adsorption layer 32L can be efficiently reduced in a reducing gas atmosphere such as hydrogen.

[0062] The movable electrode 31 illustrated in Figure 8 may be the same layer as any of the multiple conductive layers described in Figures 2(a) to 2(f) (e.g., conductive layer 26a, conductive layer 27a, conductive layer 26b, conductive layer 27b, conductive layer 28a, conductive layer 29a, conductive layer 28b, and conductive layer 29b). The heater 32H may be the same layer as any of the multiple conductive layers described in Figures 2(a) to 2(f).

[0063] In the sensor 130, the control unit 70 further includes a capacitance detection unit 72. The capacitance detection unit 72 is capable of detecting the capacitance between the fixed electrode 35 and the movable electrode 31. For example, the capacitance detection unit 72 can output a first value corresponding to the capacitance between the fixed electrode 35 and the movable electrode 31. The control unit 70 can output a second value obtained by correcting the first value using a first signal Sg1.

[0064] As shown in Figures 7 and 8, the second sensor unit 10B is provided with a movable electrode terminal 38a and a fixed electrode terminal 38b. The movable electrode terminal 38a is electrically connected to the movable electrode 31. The fixed electrode terminal 38b is electrically connected to the fixed electrode 35. For example, the movable electrode terminal 38a is electrically connected to the second other electrode 22V via wiring 31La and via 25V. The fixed electrode terminal 38b is electrically connected to the second electrode 22U via wiring 31Lb.

[0065] The capacitance between the fixed electrode 35 and the movable electrode 31 is detected by the capacitance detection unit 72 via the second electrode 22U and the second other electrode 22V. In order to reduce the size of the sensor 130, the distance L2 between the second electrode 22U and the second other electrode 22V may be set to be short. In this case, the second parasitic resistance H2 between the second electrode 22U and the second other electrode 22V has an effect on the measurement of the capacitance between the fixed electrode 35 and the movable electrode 31. In this embodiment, the first value of the capacitance measurement is corrected using the first signal Sg1 corresponding to the change in the second parasitic resistance H2. High accuracy can be obtained in the corrected second value.

[0066] As shown in Figure 7, in this example, a first switch SW1 is provided in the current path (second other electrode wiring 22Lb) between the second other electrode 22V and the second resistive element 22. As shown in Figure 7, for example, the first other electrode 21V is set to a fixed potential GND. The fixed potential GND is, for example, the ground potential. In this example, a second switch SW2 is provided in the current path between the first other electrode 21V and the second other electrode 22V. Multiple operations may be performed in the sensor 130 by the operation of these switches.

[0067] Figure 9 is a schematic plan view illustrating one of several operations in the sensor according to the third embodiment. Figure 9 corresponds to the first operation OP1. The first operation OP1 corresponds to, for example, the resistance measurement mode. As shown in Figure 9, in the first operation OP1, the first switch SW1 and the second switch SW2 are in a conductive state. At this time, the second resistive element 22 is connected to the second other electrode 22V, and the second other electrode 22V is set to a fixed potential GND. In this first operation OP1, for example, the operation described with respect to the sensor 110 is performed. For example, the differential circuit 71 outputs a first signal Sg1 corresponding to the difference between the first voltage v1 related to the first resistive element 21 and the second voltage v2 related to the second resistive element 22. That is, humidity is detected.

[0068] Figure 10 is a schematic plan view illustrating one of several operations in the sensor according to the third embodiment. Figure 10 corresponds to the second operation mode OP2. The second operation mode OP2 corresponds to the capacitance measurement mode. As shown in Figure 10, in the second operation mode OP2, the first switch SW1 and the second switch SW2 are in a non-conductive state. At this time, the second resistive element 22 is isolated from the second other electrode 22V. The second other electrode 22V is isolated from the fixed potential GND. In the second operation mode OP2, a change in capacitance in the second sensor unit 10B is detected. For example, a change in capacitance is detected by the capacitance detection unit 72. The change in capacitance is the change in capacitance between the fixed electrode 35 and the movable electrode 31. The change in capacitance varies depending on the substance being detected (e.g., hydrogen). In the second operation mode OP2, a first value corresponding to the concentration of the substance being detected is derived, and the first value is corrected based on the first signal Sg1. The corrected second value is output from, for example, the control unit 70.

[0069] Figure 11 is a schematic plan view illustrating a sensor according to the third embodiment. As shown in Figure 11, in the sensor 130, the control unit 70 may include a control circuit 75. The control circuit 75 supplies a first control signal Sc1 to the first switch SW1. The opening and closing operation of the first switch SW1 is controlled by the first control signal Sc1. The control circuit 75 supplies a second control signal Sc2 to the second switch SW2. The opening and closing operation of the second switch SW2 is controlled by the second control signal Sc2. The control circuit 75 may also supply a third control signal Sc3 to the capacitance detection unit 72. The operation of the capacitance detection unit 72 is controlled by the third control signal Sc3.

[0070] As shown in Figure 11, the control unit 70 may include a differential circuit 71. A first voltage v1 and a second voltage v2 are input to the differential circuit 71. The output of the differential circuit 72 may be supplied to the control circuit 75. The differential circuit 71 may be included in, for example, an ADC (Analog-to-digital Converter). In this example, the control unit 70 includes a capacitance detection unit 72, a first switch SW1, and a second switch SW2.

[0071] In this embodiment, the first value before correction (the value corresponding to the capacitance between the fixed electrode 35 and the movable electrode 31) increases significantly as humidity rises. In contrast, the second value after correction remains substantially unchanged even when humidity changes. This correction allows for the detection of the target substance with high accuracy while suppressing the effects of humidity.

[0072] Figure 12 is a block diagram illustrating a sensor according to the third embodiment. As shown in Figure 12, in the sensor 131 according to this embodiment, the first sensor section 10A is provided with a first electrical resistance Rp1 and a second electrical resistance Rp2. The second sensor section 10B is provided with a first capacitance C1 between the fixed electrode 35 and the movable electrode 31. The second sensor section 10B is provided with a heater (heater 32H: see Figure 8).

[0073] As shown in Figure 12, for example, a control unit 70 is provided on the module board 77. As shown in Figure 12, the control unit 70 includes an ADC. The ADC includes, for example, a differential circuit 71. A first voltage v1 corresponding to a first electrical resistance Rp1 and a second voltage v2 corresponding to a second electrical resistance Rp2 are input to the ADC (differential circuit 71). For example, humidity is detected by detecting the difference between the first voltage v1 and the second voltage v2. For example, humidity is detected by detecting the difference between the first electrical resistance Rp1 and the second electrical resistance Rp2.

[0074] For example, the voltage v0 across the reference resistor "R_ref" may be input to the ADC. The temperature coefficient of the reference resistor "R_ref" is low. For example, temperature can be detected by detecting the difference between voltage v0 and a first voltage v0. For example, temperature can be detected by detecting the difference between the reference resistor "R_ref" and a first electrical resistance Rp1. The reference resistor "R_ref" and the first electrical resistance Rp1 may correspond to temperature sensors, for example. The detection result may be corrected based on the temperature detected by the temperature sensor.

[0075] The control unit 70 includes, for example, an MCU (Microcomputer Unit). The first signal Sg1 output from the ADC is supplied to the MCU. The MCU may correspond to, for example, a control circuit 75.

[0076] The control unit 70 includes, for example, a CDC (Capacitance-to-digital Converter). The CDC converts changes in the first capacitance C1 into a digital signal. The CDC corresponds to a part of the capacitance detection unit 72.

[0077] The signal (first value) output from the CDC is supplied to the MCU. In the MCU, the first value is corrected based on the first signal Sg1, and a second value is output. The first signal Sg1 may include information about humidity and information about temperature. The first value may be corrected and a second value output based on at least one of temperature and humidity.

[0078] As shown in Figure 12, the control unit 70 may include a power supply circuit 76a. The control unit 70 may include a communication circuit 76b. The communication circuit 76b may include a wireless transceiver circuit. The control unit 70 may include a boost circuit 76c. Current may be supplied to the heater from the boost circuit 76c. In this embodiment, the boost circuit 76c may be omitted. For example, current may be supplied to the heater from the output section of the MCU.

[0079] The following sequence of operations may be performed in sensor 131.

[0080] For example, in the first step, temperature is detected by measuring the difference between the first voltage v1 and the voltage v0 of the reference resistor "R_ref". In the second step, parasitic resistance is detected based on the difference between the first voltage v1 and the second voltage v2. A first signal Sg1 is generated. In the third step, current is supplied to the heater 32H, and the temperature of the connection part 32 is raised. In the fourth step, the first capacitance C1 is measured. In the fifth step, the supply of current to the heater 32H is terminated. In the sixth step, the measured value of the first capacitance C1 is corrected based on the temperature detection result. This corrected result may be taken as the first value. In the seventh step, the value of the first capacitance C1 after temperature correction is corrected based on the first signal Sg1 to obtain the second value.

[0081] In this embodiment, for example, moisture does not substantially adhere to parts of the sensor other than its surface. For example, only fluctuations due to moisture adsorption between pads are detected. For example, analog wiring included in the sensor may be sandwiched between ground layers (metal layers). This suppresses moisture adsorption around the analog wiring.

[0082] Figure 13 is a schematic cross-sectional view illustrating a sensor according to an embodiment. As shown in Figure 13, the sensor 140 according to the embodiment includes a container 61 and a circuit board 62 in addition to the first sensor unit 10A. At least a portion of the control unit 70 is sealed by the container 61 and the circuit board 62. For example, at least one of the CDC and ADC included in the control unit 70 is sealed by the container 61 and the circuit board 62. In this case as well, the first electrode 21U, the first other electrode 21V, the second electrode 22U, and the second other electrode 22V are not covered by the container 61 and the circuit board 62.

[0083] The circuit board 62 may include, for example, a first ground layer 62a, an analog signal layer 62b, a second ground layer 62c, and a digital signal layer 62d. These layers may be provided within the insulating member 41. The analog signal layer 62b, the second ground layer 62c, and the digital signal layer 62d are provided between the first ground layer 62a and the container 61. Noise is further suppressed.

[0084] According to the embodiment, a sensor capable of improving detection performance can be provided.

[0085] (Composition 1) Insulating material, The first element section, wherein the first element section is A first resistive element, including a first resistive end and a first other resistive end, covered by the insulating member, A first electrode electrically connected to the first resistor terminal and not covered by the insulating member, The first other electrode, which is electrically connected to the first other resistance end and is not covered by the insulating member, The first element portion includes, The second element section, wherein the second element section is A second resistive element, including a second resistive end and a second other resistive end, covered by the insulating member, A second electrode electrically connected to the second resistor terminal and not covered by the insulating member, A second other electrode that is electrically connected to the second other resistance terminal and is not covered by the insulating member, The second element section includes, It includes a first sensor section, A sensor in which the second distance between the second electrode and the second other electrode is shorter than the first distance between the first electrode and the first other electrode.

[0086] (Configuration 2) Insulating material, The first element section, wherein the first element section is A first resistive element, including a first resistive end and a first other resistive end, covered by the insulating member, A first electrode electrically connected to the first resistor terminal and not covered by the insulating member, The first other electrode, which is electrically connected to the first other resistance end and is not covered by the insulating member, The first element portion includes, The second element section, wherein the second element section is A second resistive element, including a second resistive end and a second other resistive end, covered by the insulating member, A second electrode electrically connected to the second resistor terminal and not covered by the insulating member, A second other electrode that is electrically connected to the second other resistance terminal and is not covered by the insulating member, The second element section includes, It includes a first sensor section, The insulating member is A first insulating region between the first electrode and the first other electrode, A second insulating region between the aforementioned second electrode and the aforementioned second other electrode, Includes, The insulating member is The first material of the first insulating region, The first contact angle with respect to water in the first insulating region, It has, The insulating member is A second material in the second insulating region, which is different from the first material, A second contact angle with respect to water in the second insulating region, which is smaller than the first contact angle, A sensor having at least one of the following.

[0087] (Composition 3) The sensor according to configuration 1, wherein the contact angle of the second material with respect to water is smaller than the contact angle of the first material with respect to water.

[0088] (Composition 4) The sensor according to configuration 3, wherein the first material comprises at least one of fluorine and an alkyl group.

[0089] (Composition 5) The second electrode is The base of the second electrode and Multiple second electrode protrusions electrically connected to the second electrode base, Includes, The sensor according to any one of configurations 1 to 4, wherein at least a portion of the second other electrode is located between one of the plurality of second electrode protrusions and another of the plurality of second electrode protrusions.

[0090] (Composition 6) The second other electrode is, The base of the second other electrode, Multiple second electrode protrusions electrically connected to the second other electrode base, Includes, The sensor according to configuration 5, wherein one of the plurality of second electrode protrusions is located between one of the plurality of other second electrode protrusions and another of the plurality of other second electrode protrusions.

[0091] (Composition 7) The sensor according to any one of configurations 1 to 6, wherein the electrical resistance of the first resistive element is 0.9 times or more and 1.1 times or less the electrical resistance of the second resistive element.

[0092] (Composition 8) The sensor according to any one of configurations 1 to 6, wherein the electrical resistance of the second resistive element is 1 kΩ or more and 20 kΩ or less.

[0093] (Composition 9) The sensor according to any one of configurations 1 to 8, wherein at least one of the first electrode, the first other electrode, the second electrode, and the second other electrode includes at least one selected from the group consisting of Pd, Au, Pt, and Al.

[0094] (Composition 10) The sensor according to any one of configurations 1 to 9, wherein at least one of the first resistive element and the second resistive element includes TiN.

[0095] (Composition 11) The first sensor unit is, A first electrode wiring that electrically connects the first resistor terminal to the first electrode, A first other electrode wiring that electrically connects the first other resistor end to the first other electrode, A second electrode wiring that electrically connects the second resistor terminal to the second electrode, A second other electrode wiring that electrically connects the second other resistor terminal to the second other electrode, This further includes, The sensor according to any one of configurations 1 to 10, wherein at least one of the first electrode wiring, the first other electrode wiring, the second electrode wiring, and the second other electrode wiring contains Al.

[0096] (Composition 12) The sensor according to any one of configurations 1 to 11, wherein the insulating member comprises at least one selected from the group consisting of oxygen and nitrogen, and silicon.

[0097] (Composition 13) The second electrical resistance between the second electrode and the second other electrode changes in accordance with the change in humidity of the space around the first sensor unit. The sensor according to any one of configurations 1 to 12, wherein the first electrical resistance between the first electrode and the first other electrode does not change in response to the change in humidity, or the first rate of change of the first electrical resistance with respect to the change in humidity is lower than the second rate of change of the second electrical resistance with respect to the change in humidity.

[0098] (Composition 14) It further includes a control unit, The control unit, A first supply circuit that supplies a first current to the first resistive element via the first electrode and the first other electrode, A second supply circuit that supplies a second current to the second resistive element via the second electrode and the second other electrode, Differential circuits and, Includes, The differential circuit is A first input section to which a first voltage between the first electrode and the first other electrode is input, A second input section into which a second voltage is input between the second electrode and the second other electrode, An output unit that outputs a first signal corresponding to the difference between the first voltage and the second voltage, The sensor described in configuration 13, including the sensor.

[0099] (Composition 15) Further equipped with a second recovery unit, The second recovery unit is, Substrate and, A fixed electrode fixed to the substrate, A support portion fixed to the base, The movable electrode supported by the support portion, Includes, A first gap is provided between the fixed electrode and the movable electrode. The control unit further includes a capacity detection unit, The capacitance detection unit outputs a first value corresponding to the capacitance between the fixed electrode and the movable electrode. The control unit is capable of outputting a second value obtained by correcting the first value using the first signal, as described in configuration 14.

[0100] (Composition 16) The sensor according to configuration 15, wherein the first value changes depending on the substance to be detected contained in the space around the second sensor unit.

[0101] (Composition 17) The sensor according to configuration 16, wherein the first distance between the fixed electrode and the movable electrode changes according to the concentration of the substance in the space.

[0102] (Composition 18) The second sensor portion further includes a connecting portion that is supported by the support portion and supports the movable electrode, The sensor according to configuration 17, wherein the connecting portion is deformable according to the concentration of the substance.

[0103] (Composition 19) Container and Circuit board and Furthermore, At least a portion of the control unit is sealed by the container and the circuit board. The sensor according to any one of configurations 1 to 18, wherein the first electrode, the first other electrode, the second electrode, and the second other electrode are not covered by the container and the circuit board.

[0104] In this specification, "electrically connected" includes not only cases where a connection is made by direct contact, but also cases where a connection is made via other conductive members or the like.

[0105] In this specification, "perpendicular" and "parallel" do not mean strictly perpendicular and strictly parallel, but also include variations in the manufacturing process, for example, and it is sufficient if they are substantially perpendicular and substantially parallel.

[0106] The embodiments of the present invention have been described above with reference to specific examples. However, the present invention is not limited to these specific examples. For example, the specific configuration of each element included in the sensor, such as the sensor unit, resistive element, electrode, and control unit, is included within the scope of the present invention as long as those skilled in the art can appropriately select from the known range to implement the present invention and obtain similar effects.

[0107] Combinations of two or more elements from any of the specific examples, to the extent technically feasible, are also included within the scope of the present invention, insofar as they encompass the gist of the invention.

[0108] Furthermore, all sensors that a person skilled in the art can implement by appropriately modifying the design based on the sensors described above as embodiments of the present invention also fall within the scope of the present invention, insofar as they encompass the gist of the present invention.

[0109] Furthermore, within the scope of the concept of the present invention, a person skilled in the art could conceive of various modifications and alterations, and it is understood that such modifications and alterations also fall within the scope of the present invention.

[0110] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. [Explanation of Symbols]

[0111] 10A, 10B...First and second sensor sections, 21, 22...First and second resistive elements, 21D, 22D...First and second element sections, 21La, 22La...First and second electrode wiring, 21Lb, 22Lb...First and second other electrode wiring, 21U, 22U...First and second electrodes, 21V, 22V...First and second other electrodes, 21e, 22e...First and second resistive ends, 21f, 22f...First and second other resistive ends, 21va, 21vb, 22va, 22vb...Via, 22Ap...Second electrode base, 22Aq...Second electrode protrusion, 22Bp...Second other electrode base, 22Bq...Second other electrode protrusion, 25v...Via 26a, 26b, 27a, 27b, 28a, 28b, 29a, 29b...conductive layer, 31...movable electrode, 31La, 31Lb...wiring, 32...connection part, 32H...heater, 32L...material adsorption layer, 33...support part, 35...fixed electrode, 38a...movable electrode terminal, 38b...fixed electrode terminal, 41...insulating member, 41B...substrate, 41L...insulating layer, 41s...substrate, 45a, 45b...first and second insulating regions, 61...container, 62...circuit board, 62a...first ground layer, 62b...analog signal layer, 62c...second ground layer, 62d...digital signal layer, 70...control unit, 71...differential circuit, 71a, 71b...first and second input sections, 71o…Output section, 72…Capacitance detection section, 75…Control circuit, 76a…Power supply circuit, 76b…Communication circuit, 76c…Boost circuit, 77…Module board, 78a, 78b…First and second supply circuits, ΔR…Resistance change, 110, 120, 130, 131, 140…Sensors, C0…Capacitance, C1…First capacitance, GND…Fixed potential, H1, H2…First and second parasitic resistances, L1, L2…First and second distances, OP1, OP2…First and second operations, R1, R2…Electrical resistance, Rp1, Rp2…First and second electrical resistances, Rpr…Parallel resistance component, Rx…Resistance, SW1, SW2…First and second switches, Sc1~Sc3…First to third control signals, Sg1…First signal, fm1…Frequency g1…First gap, v0…Voltage, v1, v2…First and second voltages

Claims

1. an insulating member; A first element portion, the first element portion comprising: a first resistor element including a first resistor end portion and a first other resistor end portion and covered with the insulating member; a first electrode electrically connected to the first resistor end and not covered with the insulating member; the first other electrode electrically connected to the first other resistor end portion and not covered with the insulating member; the first element portion, A second element portion, the second element portion comprising: a second resistor element including a second resistor end portion and a second other resistor end portion and covered with the insulating member; a second electrode electrically connected to the second resistor end and not covered with the insulating member; a second other electrode electrically connected to the second other resistor end portion and not covered with the insulating member; the second element portion, a first sensor unit including: A sensor, wherein a second distance between the second electrode and the second other electrode is shorter than a first distance between the first electrode and the first other electrode.

2. An insulating member; A first element portion, the first element portion comprising: a first resistor element including a first resistor end portion and a first other resistor end portion and covered with the insulating member; a first electrode electrically connected to the first resistor end and not covered with the insulating member; the first other electrode electrically connected to the first other resistor end portion and not covered with the insulating member; the first element portion, A second element portion, the second element portion comprising: a second resistor element including a second resistor end portion and a second other resistor end portion and covered with the insulating member; a second electrode electrically connected to the second resistor end and not covered with the insulating member; a second other electrode electrically connected to the second other resistor end portion and not covered with the insulating member; the second element portion, a first sensor unit including: The insulating member is a first insulating region between the first electrode and the first other electrode; a second insulating region between the second electrode and the second other electrode; Including, The insulating member is a first material of the first insulating region; a first contact angle of the first insulating region with water; and The insulating member is a second material of the second insulating region that is different from the first material; a second contact angle of the second insulating region with water that is smaller than the first contact angle; A sensor having at least one of the above.

3. The second electrode is a second electrode base; a plurality of second electrode protrusions electrically connected to the second electrode base; Including, The sensor according to claim 1 , wherein at least a portion of the second other electrode is located between one of the plurality of second electrode projections and another of the plurality of second electrode projections.

4. The first sensor unit a first electrode wiring that electrically connects the first resistor end to the first electrode; a first other electrode wiring that electrically connects the first other resistor end portion to the first other electrode; a second electrode wiring that electrically connects the second resistor end to the second electrode; a second other electrode wiring that electrically connects the second other resistor end to the second other electrode; and 4. The sensor according to claim 1, wherein at least one of the first electrode wiring, the first other electrode wiring, the second electrode wiring, and the second other electrode wiring contains Al.

5. a second electrical resistance between the second electrode and the second other electrode changes in response to a change in humidity in a space around the first sensor unit; A sensor described in any one of claims 1 to 4, wherein a first electrical resistance between the first electrode and the first other electrode does not change in response to changes in humidity, or a first rate of change of the first electrical resistance with respect to changes in humidity is lower than a second rate of change of the second electrical resistance with respect to changes in humidity.

6. Further comprising a control unit, The control unit a first supply circuit that supplies a first current to the first resistor element via the first electrode and the first other electrode; a second supply circuit that supplies a second current to the second resistor element via the second electrode and the second other electrode; A differential circuit; Including, The differential circuit comprises: a first input unit to which a first voltage between the first electrode and the first other electrode is input; a second input unit to which a second voltage between the second electrode and the second other electrode is input; an output section that outputs a first signal according to a difference between the first voltage and the second voltage; The sensor of claim 5 , comprising:

7. Further comprising a second sensor unit, The second sensor unit a substrate; a fixed electrode fixed to a substrate; a support fixed to the base; a movable electrode supported by the support portion; Including, a first gap is provided between the fixed electrode and the movable electrode; the control unit further includes a capacitance detection unit, the capacitance detection unit outputs a first value corresponding to the electrostatic capacitance between the fixed electrode and the movable electrode; The sensor according to claim 5 , wherein the control unit is capable of outputting a second value obtained by correcting the first value using the first signal.

8. The sensor according to claim 7 , wherein the first value changes depending on a substance to be detected that is contained in a space around the second sensor portion.

9. The sensor of claim 8 , wherein the first distance between the fixed electrode and the movable electrode varies depending on the concentration of the substance in the space.

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