WO2019181771A1

WO2019181771A1 - Humidity detection device

Info

Publication number: WO2019181771A1
Application number: PCT/JP2019/010787
Authority: WO
Inventors: 沙紀子棚橋; 亨宮武; 俊宏小林; 浩小野寺; 佐藤　清; 尚信大川
Original assignee: アルプスアルパイン株式会社
Priority date: 2018-03-19
Filing date: 2019-03-15
Publication date: 2019-09-26
Also published as: JP2021089139A; TW201939031A

Abstract

A humidity detection device according to one aspect of the present invention is able to perform stable measurement by suppressing drift of a measurement value in humidity detection. The humidity detection device is provided with: an insulation layer provided on a main surface of a base material; a reference part provided on the insulation layer; a detection part provided on the insulation layer so as to be juxtaposed with the reference part; and common wiring provided between the reference part and the detection part. The reference part has: a reference first electrode provided on the main surface of the base material; a reference dielectric part provided so as to encircle the reference first electrode; and a reference second electrode provided so as to encircle the reference dielectric part. The detection part has: a detection first electrode provided on the main surface of the base material; a detection dielectric part provided so as to encircle the detection first electrode; and a detection second electrode which is provided so as to encircle the detection dielectric part and in which a through hole is provided. The common wiring is provided so as to be electrically conductive to the reference first electrode and the detection first electrode by passing through the insulation layer.

Description

Humidity detector

The present invention relates to a humidity detection device, and more particularly to a humidity detection device that detects humidity at a detection unit with reference to a reference unit.

As a humidity detection device, a configuration is known in which a dielectric part is provided between two electrodes, and humidity is detected based on changes in electrical characteristics (capacitance, electrical resistance) of the dielectric part. For example, in a device that detects humidity based on a change in capacitance (capacitive humidity detection device), a reference capacitor unit (reference unit) that is not affected by the humidity of the outside air, and a humidity whose capacitance changes depending on the humidity of the outside air And a detection capacitor (detector).

The reference part is structured so that moisture does not enter from outside air, and has a constant capacity regardless of humidity. On the other hand, the detection unit has a structure in which moisture can enter from outside air, and has a configuration in which the capacity changes according to humidity. In such a capacitive humidity detection device, the relative humidity is calculated based on the difference between the output voltage from the detection unit and the output voltage from the reference unit.

Patent Document 1 discloses a moisture-sensitive element that improves the connectivity between the upper electrode and the connection terminal of the upper electrode, and improves the quality and reliability. In this moisture sensitive element, an upper electrode connection terminal is provided on a substrate, and a single metal film is formed on the moisture sensitive film so as to cover the step portion of the moisture sensitive film from the upper electrode connection terminal.

In Patent Document 2, electrical connectivity between the upper electrode and the upper electrode electrode terminal and between the upper electrode electrode terminal and the lower electrode electrode terminal and the lead wire is improved, and quality and reliability are improved. A humidity detecting element that improves the above is disclosed. In this humidity detecting element, an extension portion composed of one end portion of the upper electrode is laminated on the electrode pad to constitute an upper electrode electrode terminal.

Patent Documents 3 and 4 disclose humidity sensors in which a lower electrode of a reference unit (standard unit) and a lower electrode of a detection unit (sensor unit) are made conductive on a substrate.

Japanese Patent Laid-Open No. 06-123725 Japanese Patent Laid-Open No. 06-094663 International Publication No. 2011/065507 International Publication No. 2010/113711

In a humidity detection device having a reference unit and a detection unit, when a common wiring is provided on the substrate to conduct the lower electrode of the reference unit and the lower electrode of the detection unit, the upper electrode is used to avoid contact between the upper electrode and the common wiring. It is necessary to provide a recess (opening). When the concave portion is provided in the upper electrode, a leakage electric field is generated between the end portion of the concave portion and the lower electrode, which causes a drift of the measurement value.

An object of the present invention is to provide a humidity detection apparatus capable of performing stable measurement while suppressing drift of measurement values of humidity detection.

In order to solve the above-described problem, an embodiment of the present invention includes an insulating layer provided over a main surface of a base material, a detection unit provided over the insulating layer, and a detection unit provided over the insulating layer. And a reference line arranged in parallel, and a common wiring provided between the detection part and the reference part.
The detection part is provided so as to surround the first detection electrode provided on the insulating layer, the detection dielectric part provided so as to surround the first detection electrode, and the detection dielectric part. And a second electrode for detection provided with a through hole.
The reference portion is provided so as to surround the first reference electrode provided on the insulating layer, the reference dielectric portion provided so as to surround the first reference electrode, and the reference dielectric portion. And a second reference electrode.
The common wiring is provided so as to be electrically connected to the first electrode for detection and the first electrode for reference via the insulating layer.

According to such a configuration, since the common wiring passes through the insulating layer, the common wiring can be provided without providing a concave portion (opening) in the second electrode for detection and the second electrode for reference. Thus, the second detection electrode can surround the entire detection dielectric portion, and the second reference electrode can surround the entire reference dielectric portion, and the end of each second electrode can be surrounded by the second detection electrode. It is possible to suppress generation of an unnecessary leakage electric field at the portion. In one specific example, when the humidity detection device is viewed from the stacking direction, the entire detection dielectric part is covered with the second detection electrode except for the through holes, and the entire reference dielectric part is It is covered with a second reference electrode.

In the humidity detector, it is preferable that the second electrode for reference is not provided with a through hole. Thereby, an unnecessary leakage electric field does not occur between the first reference electrode and the second reference electrode due to the through hole.

The humidity detection apparatus further includes a reference lead-out wiring that is electrically connected to the reference second electrode, and a detection lead-out wiring that is conductive to the second detection electrode. The detection lead-out wiring and the reference lead-out wiring are further provided. However, it may be provided in the insulating layer.

In the humidity detection device, it is preferable that the reference lead-out wiring and the detection lead-out wiring are provided in the same layer as the common wiring. Thus, the detection lead-out wiring, the reference lead-out wiring, and the common wiring can be formed in the same process.

In the humidity detection device, a protective layer having higher humidity resistance than the insulating layer may be provided around the detection unit and the reference unit on the insulating layer. Thereby, the moisture which permeates into the dielectric part from the side surface of the second electrode for reference and the side surface of the second electrode for detection can be suppressed.

In the humidity detection device, it is preferable that a protective layer is not provided on the second detection electrode. Thereby, the influence of the leakage electric field in the vicinity of the through hole of the second electrode for detection does not reach the protective layer, and the accuracy of the measurement value is improved.

According to the present invention, it is possible to provide a humidity detection device capable of performing stable measurement while suppressing drift of measurement values of humidity detection.

(A) And (b) is a figure which illustrates the humidity detection apparatus which concerns on this embodiment. (A) And (b) is a figure which illustrates the humidity detection apparatus which concerns on a reference example. (A) And (b) is a figure which illustrates the simulation result of electric field distribution. (A) And (b) is a figure which illustrates the simulation result of electric field distribution. It is a figure which illustrates the comparison result of drift characteristics. It is sectional drawing which shows the example of application of a humidity detection apparatus. (A) And (b) is sectional drawing which shows the application example of a humidity detection apparatus. (A) And (b) is sectional drawing which shows the application example of a humidity detection apparatus.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same members are denoted by the same reference numerals, and the description of the members once described is omitted as appropriate.

(Configuration of humidity detector)
1A and 1B are diagrams illustrating a humidity detection device according to the present embodiment.
FIG. 1A shows a cross-sectional view of the humidity detection device 1, and FIG. 1B shows a plan view of the humidity detection device 1. The cross-sectional view shown in FIG. 1A is a cross-sectional view taken along line AA shown in FIG.

As shown in FIG. 1, the humidity detection device 1 according to the present embodiment is a device that detects the humidity of outside air as an electrical signal, and includes an insulating layer 30 provided on a base material 50, a detection unit 10, and a reference. Unit 20 and common wiring 70. The humidity detection device 1 detects humidity based on a capacity difference between the detection unit 10 and the reference unit 20.

As the base material 50, for example, silicon is used. An insulating layer 30 made of, for example, silicon oxide is formed on the main surface 50 a of the base material 50, and the detection unit 10 and the reference unit 20 are formed side by side on the insulating layer 30. A pad electrode 15 that is electrically connected to the detection unit 10 and the reference unit 20 is provided on the insulating layer 30.

The detection unit 10 includes a first detection electrode 110 provided on the insulating layer 30, a detection dielectric unit 130 provided so as to surround the first detection electrode 110, and a detection dielectric unit 130. And a second electrode for detection 120 provided so as to surround the outer periphery. Thus, a capacitance in which the detection first electrode 110, the detection dielectric portion 130, and the detection second electrode 120 are stacked in this order in the first direction D1 orthogonal to the main surface 50a is configured.

For the first electrode 110 for detection and the second electrode 120 for detection, a refractory metal material such as ruthenium (Ru) or tantalum (Ta) is suitably used as a conductive material that is not easily oxidized. In addition, for example, polyimide resin is used for the detection dielectric portion 130.

The second electrode 120 for detection is provided with a plurality of through holes 120h at predetermined intervals. External moisture reaches the detection dielectric portion 130 through the through-hole 120h. The dielectric constant of the detection dielectric portion 130 changes according to the amount of moisture contained in the detection dielectric portion 130. Thereby, the electrostatic capacitance between the 1st electrode 110 for a detection and the 2nd electrode 120 for a detection changes, and humidity can be detected based on the changed electrostatic capacitance.

The reference unit 20 has a stacked structure similar to that of the detection unit 10. That is, the reference unit 20 includes a reference first electrode 210 provided on the insulating layer 30, a reference dielectric unit 230 provided so as to surround the reference first electrode 210, and a reference dielectric. A second reference electrode 220 provided so as to surround the portion 230.

Thereby, a capacitor in which the first reference electrode 210, the reference dielectric portion 230, and the second reference electrode 220 are stacked in this order in the first direction D1 is formed. The reference second electrode 220 is not provided with a through hole, and the reference dielectric portion 230 is surrounded by the reference second electrode 220, so that almost no moisture from the outside enters the reference portion 20. Absent. For this reason, the dielectric constant of the reference dielectric part 230 hardly changes. Therefore, the capacitance of the reference portion 20 constituted by the first reference electrode 210, the second reference electrode 220, and the reference dielectric portion 230 is substantially constant. The relative humidity can be detected from the difference between the output voltage based on the electrostatic capacity in the reference unit 20 and the output voltage based on the electrostatic capacity in the detection unit 10.

A protective layer 40 may be provided around the detection unit 10 and the reference unit 20 on the insulating layer 30. When providing the protective layer 40, it is preferable to use a material having higher moisture resistance than the insulating layer 30. For example, silicon nitride (SiN) is used for the protective layer 40. Accordingly, moisture that enters the detection dielectric portion 130 and the reference dielectric portion 230 from the side surface of the detection second electrode 120 and the side surface of the reference second electrode 220 can be suppressed.

The common wiring 70 is provided between the detection unit 10 and the reference unit 20. In the present embodiment, the common wiring 70 is provided so as to be electrically connected to the detection first electrode 110 and the reference first electrode 210 via the insulating layer 30. That is, the common wiring 70 is provided between the main surface 50 a of the base material 50 and the surface 30 a opposite to the main surface 50 a of the insulating layer 30.

The common wiring 70, the first electrode for detection 110, and the first electrode for reference 210 are located in different layers. Therefore, the first electrode for detection 110 provided on the insulating layer 30 and the first electrode for reference 210 are brought into conduction by the common wire 70 through the through hole provided at the end of the common wire 70. .

Further, a detection lead-out wiring 12 is provided between the detection second electrode 120 and the pad electrode 15, and a reference lead-out wiring 13 is provided between the reference second electrode 220 and the pad electrode 15. The detection lead-out wiring 12 and the reference lead-out wiring 13 are provided in the insulating layer 30. The detection lead-out wiring 12 and the reference lead-out wiring 13 are preferably provided in the same layer as the common wiring 70. Thereby, the detection lead-out wiring 12, the reference lead-out wiring 13, and the common wiring 70 can be formed in the same process.

As described above, in the humidity detection device 1 according to the present embodiment, since the common wiring 70 is provided through the insulating layer 30, the detection second electrode 120 and the reference second electrode 220 are recessed ( The common wiring 70 can be provided without providing an opening. Since it is not necessary to provide a recess (opening) for the common wiring 70 to pass through the second detection electrode 120 and the second reference electrode 220, the outer peripheral position of the second detection electrode 120 is detected over the entire outer periphery. It is outside the outer peripheral position of the dielectric part 130 for use. Further, the outer peripheral position of the reference second electrode 220 is outside the outer peripheral position of the reference dielectric portion 230 over the entire outer periphery.

Accordingly, the second detection electrode 120 can surround the entire detection dielectric portion 130 except for the through-hole 120h, and the second reference electrode 220 can surround the entire reference dielectric portion 230. Can do. Specifically, when viewed from the stacking direction (first direction D1), the entire detection dielectric portion 130 is covered by the detection second electrode 120 except for the through-hole 120h, and the reference dielectric portion 230 The whole is covered with the second reference electrode 220. Therefore, it is possible to suppress the occurrence of unnecessary leakage electric fields at the ends of the second detection electrode 120 and the second reference electrode 220.

2A and 2B are diagrams illustrating a humidity detection device according to a reference example.
2A shows a cross-sectional view of the humidity detection device 1, and FIG. 1B shows a plan view of the humidity detection device 2. As shown in FIG. The cross-sectional view shown in FIG. 2 (a) is a cross-sectional view taken along the line BB shown in FIG. 2 (b).

In the humidity detector 2 according to the reference example, the common wiring 75 is provided in the same layer as the first electrode 110 for detection and the first electrode 210 for reference. That is, the common wiring 75 is provided on the insulating layer 30 so as to connect between the first detection electrode 110 and the first reference electrode 210.

In such a wiring structure, the end of the second electrode for detection 120 and the end of the second electrode for reference 220 are prevented so that the common wiring 75, the second electrode for detection 120, and the second electrode for reference 220 are not short-circuited. The part is provided with a recess 90. The recess 90 is provided at a position overlapping the common wiring 75 in the first direction D1. By providing the common wiring 75 in accordance with the position of the recess 90, the distance between the common wiring 75, the second electrode for detection 120 and the second electrode for reference 220 is maintained, and a short circuit between them can be prevented. .

Further, in the humidity detection device 2 according to the reference example, the detection dielectric portion 130 and the reference dielectric portion 230 are exposed at the position of the recess 90, so that the portion other than the through hole 120h is covered with the protective layer 40. ing. In addition, since the protective layer 40 covers the edge of the through hole 120h, the capacitance adjusting hole 220h may be provided in the reference second electrode 220 in order to reflect the change in the dielectric constant at this portion in the reference unit 20.

In the humidity detection device 1 according to the present embodiment and the humidity detection device 2 according to the reference example, a difference occurs in the electric field distribution due to such a difference in structure.
FIG. 3A to FIG. 4B are diagrams illustrating simulation results of electric field distribution.
FIGS. 3A and 3B show the simulation results of the electric field distribution at the center portion of the reference portion 20, and FIGS. 4A and 4B show the electric field distribution at the end portion of the reference portion 20. Simulation results are shown. (A) is the simulation result of the humidity detection apparatus 1 which concerns on this embodiment, respectively, (b) is the simulation result of the humidity detection apparatus 2 which concerns on a reference example.

As shown in FIG. 3B, in the humidity detection device 2 according to the reference example, a capacity adjustment hole 220h is provided in the central portion of the reference second electrode 220. For this reason, the electric field distribution in the central portion of the reference second electrode 220 of the humidity detecting device 2 according to the reference example causes an electric field to leak at the end of the capacity adjustment hole 220h, and the protective layer 40 is also affected by the electric field. (See FIG. 3B). On the other hand, as shown in FIG. 3A, in the humidity detection device 1 according to the present embodiment, the capacitance adjusting hole 220h is not provided in the central portion of the second reference electrode 220, and is flat. For this reason, the electric field distribution in the central portion of the reference second electrode 220 of the humidity detection device 1 according to the present embodiment is uniform.

Further, as shown in FIG. 4B, in the humidity detection device 2 according to the reference example, a recess 90 for preventing a short circuit with the common wiring 70 is provided at the end of the reference second electrode 220. . For this reason, in the electric field distribution at the end of the reference second electrode 220 of the humidity detection device 2 according to the reference example, an electric field leaks in the vicinity of the recess 90, and the protective layer 40 is also affected by the electric field. On the other hand, as shown in FIG. 4A, in the humidity detection device 1 according to the present embodiment, no recess is provided at the end of the reference second electrode 220, and the end of the reference dielectric portion 230 is not provided. It is provided to cover up to. For this reason, there is little electric field leakage at the end of the first reference electrode 210 or the end of the second reference electrode 220. In particular, in the humidity detection device 1 according to the present embodiment, since the protective layer 40 is not provided on the reference second electrode 220, it is not necessary to consider the influence of the electric field on the protective layer 40.

3 and 4 show electric field distribution simulation results at the reference unit 20, but the electric field distribution at the end of the second detection electrode 120 is the same as that of the reference unit 20. Further, the electric field distribution in the vicinity of the through hole 120h is the same as the electric field distribution in the vicinity of the capacity adjustment hole 220h shown in FIG. 3B, but in this embodiment, the protection is provided on the detection second electrode 120. Since the layer 40 is not provided, it is not necessary to consider the influence of the electric field on the protective layer 40 in the vicinity of the through hole 120h.

FIG. 5 is a diagram illustrating a comparison result of drift characteristics.
In FIG. 5, the horizontal axis represents time (hr), and the vertical axis represents the amount of change in capacity (% RH) from the initial measurement.
FIG. 5 shows a drift characteristic G1 of the humidity detection device 1 according to the present embodiment and a drift characteristic G2 of the humidity detection device 2 according to the reference example. Drift characteristics G1 and G2 indicate changes in measured values of the

humidity detection apparatuses

1 and 2 from the start of measurement until 1000 hours have passed. Due to the difference in structure as described above, the humidity detection drift amount in the humidity detection device 1 according to the present embodiment is suppressed by about 1% with respect to the humidity detection drift amount in the humidity detection device 2 according to the reference example. Is done.

(Application example)
6 to 8B are cross-sectional views showing application examples of the humidity detection device.
In the application example illustrated in FIG. 6, a frame portion 60 is provided around the detection unit 10. The frame portion 60 is formed, for example, by etching silicon into a frame shape, and is connected to the base material 50 via an adhesive 65. By using silicon as the frame portion 60, the frame portion 60 can be configured using the workability and hardness of silicon. By disposing the detection unit 10 in the opening 601 of the frame 60, external moisture is taken into the detection dielectric unit 130 from the opening 601 through the through hole 120 h of the detection second electrode 120. The dielectric constant of the detection dielectric portion 130 changes according to the moisture taken into the detection dielectric portion 130, and humidity can be detected based on this dielectric constant.

7A has a structure in which the adhesive 65 for attaching the frame part 60 on the reference part 20 is not provided. Since the adhesive 65 is not provided on the reference unit 20, the capacity variation of the reference unit 20 can be suppressed. That is, the electric field formed by applying a voltage to the first reference electrode 210 and the second reference electrode 220 extends not only on the reference dielectric portion 230 side but also above the reference second electrode 220. Since the adhesive 65 is not provided above the second reference electrode 220, it is not affected by the change in the dielectric constant of the adhesive 65 due to the expansion of the electric field. can do.

In the humidity detection device 1C shown in FIG. 7B, an opening 601 of the frame 60 is provided above the detection unit 10 and the reference unit 20. That is, the frame part 60 is not provided above the reference part 20 as well as above the detection part 10. As a result, the environment (structure) above the reference unit 20 matches the environment (structure) above the detection unit 10, and relative humidity can be calculated with high accuracy.

8A has a structure in which the adhesive 65 for attaching the frame portion 60 on the reference portion 20 is not provided, similarly to the humidity detection device 1B. The difference from the humidity detection device 1 </ b> B is that an adhesive 65 is provided between the reference unit 20 and the detection unit 10. With such a structure, similarly to the humidity detection device 1B, it is not necessary to be affected by the change in the dielectric constant of the adhesive 65 due to the expansion of the electric field above the reference portion 20. Furthermore, since the periphery of the reference portion 20 is surrounded by the adhesive 65, adhesion of particles to the reference portion 20 can be prevented. Thereby, the capacity | capacitance fluctuation | variation of the reference part 20 by the adhesive agent 65 and particle adhesion can be suppressed.

In the humidity detection device 1E shown in FIG. 8B, each of the detection unit 10 and the reference unit 20 has a structure separated from the adhesive 65 for attaching the frame unit 60. For example, the pillar 603 is provided on the frame 60, and when the frame 60 is attached, the detection unit 10 and the reference unit 20 are surrounded by the pillar 603. The adhesive 65 is attached to a portion without the pillar 603 except on the detection unit 10 and the reference unit 20. With such a structure, the detection unit 10 and the reference unit 20 and the adhesive 65 are not adjacent to each other.

Since the adhesive 65 is made of a resin such as polyimide, it has a hygroscopic property. The dielectric constant of the adhesive 65 changes as the adhesive 65 absorbs moisture. When the adhesive 65, the detection unit 10, and the reference unit 20 are adjacent to each other, the detection unit 10 and the reference unit 20 are easily affected by the change in the dielectric constant of the adhesive 65. Like the humidity detection device 1E, the detection unit 10 and the reference unit 20 are separated from the adhesive 65 by the pillar 603, so that it is difficult to be affected by the dielectric constant of the adhesive 65, and the humidity detection is highly accurate. Can be performed.

As described above, according to the present embodiment, it is possible to provide the

humidity detectors

1, 1B, 1C, 1D, and 1E that can suppress the drift of the measurement value of the humidity detection and can perform stable measurement. It becomes possible.

Although the present embodiment has been described above, the present invention is not limited to these examples. For example, the detection method of the humidity in the detection unit 10 and the reference unit 20 may be a method of measuring and detecting the capacitance as described above, or a method of detecting the humidity by measuring a resistance value. Good. Moreover, although the example which uses ruthenium (Ru) etc. as an electrode material was shown, you may use other electrically-conductive materials, such as aluminum and copper, for example. As a measure against particles, a protective material such as a silicone gel material may be provided so as to cover the detection unit 10 and the reference unit 20.

Further, those in which the person skilled in the art appropriately added, deleted, or changed the design of the above-described embodiment, or the combination of the features of the configuration example of the embodiment as appropriate, also have the gist of the present invention. As long as it is included, it is included in the scope of the present invention.

DESCRIPTION OF

SYMBOLS

1,1B, 1C, 1D, 1E ... Humidity detection apparatus 2 ... Humidity detection apparatus 10 ... Detection part 12 ... Detection extraction wiring 13 ... Reference extraction wiring 15 ... Pad electrode 20 ... Reference part 30 ... Insulating layer 30a ... Surface 40 ... Protective layer 50 ... Base material 50a ... Main surface 60 ... Frame portion 65 ...

Adhesives

70, 75 ... Common wiring 90 ... Depression 110 ... Detection first electrode 120 ... Detection second electrode 120h ... Through hole 130 ... Detection Dielectric part 210 ... Reference first electrode 220 ... Reference second electrode 220h ... Capacity adjustment hole 230 ... Reference dielectric part 601 ... Opening 603 ... Pillar D1 ... First direction G1 ... Drift characteristic G2 ... Drift characteristic

Claims

An insulating layer provided on the main surface of the substrate;
A detector provided on the insulating layer;
A reference unit provided on the insulating layer and juxtaposed with the detection unit;
A humidity detection device comprising a common wiring provided between the detection unit and the reference unit,
The detector is
A first electrode for detection provided on the insulating layer;
A sensing dielectric portion provided to surround the first sensing electrode;
A second electrode for detection provided to surround the detection dielectric portion and provided with a through hole;
The reference section is
A first reference electrode provided on the insulating layer;
A reference dielectric portion provided so as to surround the first reference electrode;
A reference second electrode provided so as to surround the reference dielectric part,
The common wiring is
A humidity detecting device, wherein the humidity detecting device is provided so as to be electrically connected to the first electrode for detection and the first electrode for reference through the insulating layer.
When viewed from the stacking direction,
Except for the through hole, the entire detection dielectric part is covered with the second detection electrode,
The entire reference dielectric portion is covered with the second reference electrode.
The humidity detection apparatus according to claim 1.
The humidity detection device according to claim 1 or 2, wherein the second electrode for reference is not provided with a through hole.
A lead-out wiring for detection that conducts with the second electrode for detection;
A reference lead line that is electrically connected to the second reference electrode;
The humidity detection apparatus according to any one of claims 1 to 3, wherein the detection lead-out wiring and the reference lead-out wiring are provided in the insulating layer.
The humidity detection device according to claim 4, wherein the detection lead-out wiring and the reference lead-out wiring are provided in the same layer as the common wiring.
The humidity detection according to any one of claims 1 to 5, wherein a protective layer having higher moisture resistance than the insulating layer is provided around the detection unit and the reference unit on the insulating layer. apparatus.
The humidity detection device according to claim 6, wherein the protective layer is not provided on the second electrode for detection.