Corrosion detection device and corrosion state determination system

Abstract

To provide a corrosion detection device capable of determining the corrosion resistance of a target metal, and a corrosion state determination system having the corrosion detection device.SOLUTION: According to an embodiment, a corrosion detection device 1 comprises: a substrate 3; a plurality of first metal wirings 4; a second metal electrode 5; a third metal electrode 6; and a moisture-proof cover portion 10. The plurality of first metal wirings 4 have the shape that extends in a first direction 200 and include the detection target metal. The second metal electrode is in contact with one end in the first direction 200 of each first metal wiring 4 and includes a metal more noble than the detection target metal. The third metal electrode is in contact with the other end in the first direction 200 of each first metal wiring 4. The moisture-proof cover portion 10 covers at least a portion of the first metal wirings 4, the second metal electrode 5, and the third metal electrode 6. The moisture-proof cover portion 10 includes an opening 10a at the contact portion between each first metal wiring 4 and the second metal electrode 5.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] Embodiments of the present invention relate to a corrosion detection device and a corrosion state determination system.

Background Art

[0002] In products made of metals such as aluminum, corrosion on the micron order may occur depending on the installation environment. There are three types of corrosion forms: uniform corrosion in which the metal corrodes uniformly over the entire surface, local corrosion in which corrosion occurs locally, and dissimilar metal corrosion in which corrosion occurs due to contact between dissimilar metals. Among these, local corrosion and dissimilar metal corrosion have a faster corrosion rate than uniform corrosion and may cause through-holes in the product. Aluminum is often used for heat transfer tubes, while it is difficult to use corrosion inhibitors. Therefore, there is a possibility that refrigerant gas leakage may occur in the aluminum heat transfer tubes due to these through-holes. For this reason, a technique for diagnosing the corrosion state of metals such as aluminum in the installation environment is required.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Summary of the Invention

Problems to be Solved by the Invention

[0004] Provided are a corrosion detection device capable of determining the corrosion resistance of a target metal, and a corrosion state determination system including this corrosion detection device.

Means for Solving the Problems

[0005] According to an embodiment, there is provided a corrosion detection device including a substrate, a plurality of wirings of a first metal, an electrode of a second metal, an electrode of a third metal, and a moisture-proof cover portion. The plurality of wirings of the first metal are provided on the substrate, have a shape extending along a first direction, and include a detection target metal. The electrode of the second metal is provided on the substrate, contacts one end portion of each wiring of the first metal in the first direction, and includes a metal nobler than the detection target metal. The electrode of the third metal is provided on the substrate and contacts the other end portion of each wiring of the first metal in the first direction. The moisture-proof cover portion covers at least a part of the wiring of the first metal, the electrode of the second metal, and the electrode of the third metal. Further, the moisture-proof cover portion has an opening at a contact portion between each wiring of the first metal and the electrode of the second metal.

[0006] Also, according to an embodiment, there is provided a corrosion state determination system including the corrosion detection device of the embodiment. The corrosion state determination system of the embodiment includes a power source that applies a voltage to the corrosion detection device, an ammeter that detects a current value generated by the voltage applied to the corrosion detection device, and a control device that determines the corrosion state in the corrosion detection device based on the current value measured by the ammeter.

Brief Description of the Drawings

[0007]

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Mode for Carrying Out the Invention

[0008] Hereinafter, embodiments will be described in detail with reference to the drawings. Note that components that exhibit the same or similar functions are given the same reference numeral throughout all the drawings, and redundant explanations are omitted. (First Embodiment) The first embodiment relates to a corrosion detection device. Embodiment modes 1 to 7 and Examples A to D, which are examples of the corrosion detection device of the embodiment, will be described with reference to the drawings.

[0009] (Embodiment Mode 1) The corrosion detection device of embodiment mode 1 will be described with reference to FIGS. 1 to 4. FIG. 1 is a plan view showing an overview of the corrosion detection device of embodiment mode 1. FIG. 2 is a cross-sectional view of the corrosion detection device shown in FIG. 1 cut along line II-II. FIG. 3 is a diagram showing changes in the circuit diagram and changes in current values before and after corrosion in the corrosion detection device shown in FIG. 1.

[0010] The corrosion detection device 1 shown in FIGS. 1 and 2 includes a first substrate 2, a second substrate 3, a plurality of wirings 4 of a first metal, a plurality of electrodes 5 of a second metal, an electrode 6 of a third metal, a plurality of resistors 7, and a moisture-proof cover portion 10. Further, a constant voltage power supply 8 as a power supply for current measurement and an ammeter 9 are connected to the corrosion detection device 1. In FIGS. 1 and 2, the direction parallel to the thickness direction of the first substrate 2 and the second substrate 3 is defined as the z-axis direction. Also, it is assumed that the plane intersecting the thickness direction of the first substrate 2 and the second substrate 3 is parallel to the xy plane. The first direction 200 is, for example, the direction from the electrode 5 of the second metal toward the electrode 6 of the third metal. It is assumed that the first direction 200 is parallel to the x-axis direction. The direction perpendicular to and intersecting the first direction 200 is parallel to the y-axis direction. The x-axis, y-axis, and z-axis intersect perpendicular to each other.

[0011] The first substrate 2 and the second substrate 3 each have a plane intersecting the thickness direction (z-axis direction) as the main plane (main surface). The area of the main surface 3a of the second substrate 3 is smaller than the area of the main surface 2a of the first substrate 2. The second substrate 3 is laminated on one of the main surfaces 2a of the first substrate 2. The first substrate 2 is, for example, a printed circuit board. On the other hand, the second substrate 3 is, for example, a Si substrate.

[0012] A plurality of wirings 4 of the first metal are provided on the front side (upper side) main surface 3a of the second substrate 3. Each of the plurality of wirings 4 of the first metal has a shape extending along the first direction 200 (in this case, parallel to the x-axis direction), and for example, has a strip or band shape. The plurality of wirings 4 of the first metal are arranged at intervals in the y-axis direction. Therefore, the plurality of wirings 4 of the first metal are not electrically connected to each other. The plurality of wirings 4 of the first metal have a length L in the x-axis direction x that are substantially equal, and lengths L in the y-axis direction y that are different from each other. Among the plurality of wirings 4 of the first metal, the wiring 4n with the largest length L y is located at one end in the y-axis direction. The other wirings 4 with lengths L smaller than this wiring 4n y are arranged in descending order of length L from one end to the other end in the y-axis direction. Therefore, the L of the wiring 4m located at the other end in the y-axis direction y is the smallest. y is the smallest.

[0013] The wiring 4 of the first metal is a wiring of the first metal including the metal to be detected for corrosion. Examples of the metal to be detected for corrosion include metals that can be used as a structural material or a binder (such as solder) for a connection part. As an example of the metal to be detected for corrosion, at least one metal selected from the group consisting of Fe, Al, Ti, Mg, Sn, and Pb can be mentioned. The metal to be detected for corrosion may be a group of metals (including alloys) mainly composed of at least one element selected from the group consisting of Fe, Al, Ti, Mg, Sn, and Pb. The first metal may be composed of the metal to be detected for corrosion or may contain the metal to be detected for corrosion as a main component (for example, an alloy). The main component is the component with the largest proportion in the first metal. For the wiring 4 of the first metal, only wirings of the same type of the first metal may be used, or wirings of different types of the first metal may be mixed and used.

[0014] The plurality of electrodes 5 of the second metal each have a shape extending along the first direction 200 (in this case, parallel to the x-axis direction), and for example, have a strip or band shape. For each of the plurality of electrodes 5 of the second metal, one end 5a in the x-axis direction is provided on the front (upper) main surface 3a of the second substrate 3, and the other end 5b in the x-axis direction is overlapped (in contact) with one end 4a in the x-axis direction of the wiring 4 of the first metal. Therefore, each of the wirings 4 of the first metal is electrically connected to the electrode 5 of the second metal. The plurality of electrodes 5 of the second metal are arranged at intervals from each other along the y-axis direction. Therefore, the plurality of electrodes 5 of the second metal are not electrically connected to each other.

[0015] The material of the electrode 5 of the second metal may be any material containing a metal nobler than the first metal. The second metal may be only a metal nobler than the first metal, or may be a material (for example, an alloy) mainly composed of a metal nobler than the first metal. The main component is the component with the largest proportion in the second metal. A metal nobler than the first metal may be, for example, a metal with a lower ionization tendency than the first metal. The electrode of the second metal mainly composed of a metal nobler than the first metal can cause dissimilar metal corrosion in the wiring of the first metal. For example, when the first metal contains any metal selected from the group consisting of Fe, Al, Ti, Mg, Sn, and Pb, it is desirable that the second metal contains a metal nobler than this metal. The metal can be selected from the group consisting of Au, Ag, Cu, Fe, Al, Ti, Mg, Sn, and Pb. Preferably, it is selected from the group consisting of Au, Ag, and Cu. The metal may be a metal group (including alloys) mainly composed of at least one element selected from the group consisting of Au, Ag, and Cu. The type of the metal nobler than the first metal may be one type, but can also be two or more types.

[0016] The electrode 6 of the third metal has, for example, a strip or band shape. The electrode 6 of the third metal is provided on the main surface 3a on the front side (upper side) of the second substrate 3. The other ends 4b in the x-axis direction of the plurality of wirings 4 of the first metal are each overlapped with the electrode 6 of the third metal and electrically connected.

[0017] As the material of the electrode 6 of the third metal, any type of metal can be used. The material of the electrode 6 of the third metal is preferably the same as the first metal or the second metal. Thereby, the manufacturability (manufacturing efficiency) of the corrosion detection device can be made good.

[0018] The plurality of resistors 7 are each electrically connected to one end 5a in the x-axis direction of the electrode 5 of the second metal. The plurality of resistors 7 are connected in parallel to the constant voltage power supply 8 by the wiring 11. The constant voltage power supply 8 is electrically connected to the electrode 6 of the third metal by the wiring 12. The ammeter 9 is interposed in the current path indicated by the wiring 12 between the constant voltage power supply 8 and the electrode 6 of the third metal.

[0019] The cover part 10 has a rectangular main surface along the xy plane. The main surface of the cover part 10 has an area smaller than the main surface 3a of the second substrate 3 and has a rectangular opening 10a near the center. The cover part 10 is provided on the main surface 3a of the second substrate 3. The opening 10a is located at the overlapping portion (connection portion) between one end 4a of the first metal wiring 4 in the x-axis direction and the other end 5b of the second metal electrode 5 in the x-axis direction. Therefore, only this connection portion and its vicinity will be in contact with the set environment through the opening 10a. Portions other than this connection portion, for example, the connection portion between the other end 4b of the first metal wiring 4 in the x-axis direction and the third metal electrode 6, one end 5a of the second metal electrode 5 in the x-axis direction, etc. are covered by the cover part 10. Therefore, the influence of these portions on corrosion detection can be eliminated or reduced. The material of the cover part 10 has moisture-proof properties. The moisture-proof cover part 10 suppresses the permeation of moisture. Preferably, the moisture-proof cover part 10 desirably has a barrier function against moisture and halogen. Examples of the moisture-proof material for forming the moisture-proof cover part include fluororesin, silicone resin, acrylic resin, polyolefin resin, etc. The cover part 10 can be formed, for example, by applying a coating liquid containing a moisture-proof material to the second substrate 3 provided with the first metal wiring 4, the second metal electrode 5, and the third metal electrode 6.

[0020] An example of the corrosion detection method by the corrosion detection device 1 will be described with reference to FIG. 3. FIG. 3 shows an example of the circuit diagram and current value before corrosion and the circuit diagram and current value after corrosion of the corrosion detection device 1. In the example shown in FIG. 3, the length of the first metal wiring 4 in the x-axis direction is constant, and the lengths in the y-axis direction are a (mm), b (mm), and c (mm). The lengths a, b, c satisfy the relationship a < b < c. The first metal wirings 4 are arranged in ascending order of the length in the y-axis direction along one direction of the y-axis. Let the resistance of the first metal wiring 4 with a length of a (mm) in the y-axis direction be r 1 Ω, and let the resistance of the resistor 7 connected to this wiring 4 via the second metal electrode 5 be R 1 Ω. Let the resistance of the first metal wiring 4 with a length of b (mm) in the y-axis direction be r 2Let it be Ω, and let the resistance of resistor 7 connected to this wiring 4 via the electrode 5 of the second metal be R 2 Let it be Ω. Also, let the resistance of the wiring 4 of the first metal with a length in the y-axis direction of c (mm) be r 3 Let it be Ω, and let the resistance of resistor 7 connected to this wiring 4 via the electrode 5 of the second metal be R 3 Let it be Ω. Let the current value of the circuit before corrosion be I ini (A), and let the voltage value be V (V). The current value I of the circuit before corrosion ini is, as shown in FIG. 3, r 1 Ω, r 2 Ω, r 3 Ω, R 1 Ω, R 2 Ω and R 3 Ω, and is represented by the product of the combined resistance calculated from and the voltage value V

[0021] Suppose that due to corrosion, for example, the wiring 4 of the first metal with a length in the y-axis direction of a (mm) is disconnected. As a result, the combined resistance of the wiring 4 of the first metal and the resistor 7 in the circuit after corrosion is r 2 Ω, r 3 Ω, R 2 Ω and R 3 Ω. Therefore, the current value I of the circuit after corrosion corr is, as shown in FIG. 3, r 2 Ω, r 3 Ω, R 2 Ω and R 3 Ω, and is represented by the product of the combined resistance calculated from and the voltage value V

[0022] Since the voltage of the circuit is set to a constant voltage V, by comparing the current value I of the circuit before corrosion ini and the current value I of the circuit after corrosion corr it is possible to detect the change in the combined resistance of the wiring 4 of the first metal and the resistor 7 due to corrosion. As a result, it is possible to identify which of the wirings 4 of the first metal has been disconnected. Thereby, it is possible to determine the corrosion resistance of the first metal in the set environment

[0023] Also, by varying the length of the wiring 4 of the first metal in the y-axis direction, the ease of corrosion of the wiring 4 of the first metal can be changed. For example, when the length of the wiring 4 of the first metal in the y-axis direction is shortened, the wiring 4 of the first metal is more likely to be corroded, and the time until disconnection can be shortened. Therefore, by varying the length of the wiring 4 of the first metal in the y-axis direction, it is possible to determine the ease of corrosion of the wiring 4 of the first metal in the set environment from the difference in the time until disconnection.

[0024] (Corrosion detection device 1 of Example A in Embodiment 1) As a specific example of the detection method described with reference to FIG. 3, the corrosion detection device 1 of Example A will be described with reference to FIGS. 4 and 5. FIG. 4 is a schematic circuit diagram of the corrosion detection device 1 of Example A. FIG. 5 is a graph showing changes in current values before and after corrosion of the corrosion detection device 1 of Example A. The plurality of first metal wirings 4 are, for example, Al wirings. The material of the second metal electrode 5 is, for example, Cu. The material of the third metal electrode 6 is, for example, Cu. Each of the first metal wirings 4 has a length of 5 mm in the first direction 200 (parallel to the x-axis direction) and a length of 5 nm in the z-axis direction. Also, the lengths of the first metal wirings 4 in the y-axis direction are 1 (mm), 4 (mm), and 8 (mm), respectively. The first metal wirings 4 are arranged in ascending order of the length in the y-axis direction along one direction of the y-axis. The resistance of the first metal wiring 4 with a length of 1 (mm) in the y-axis direction is 0.28 Ω, and the resistance of the resistor 7 connected to this wiring 4 via the second metal electrode 5 is 1000 Ω. The resistance of the first metal wiring 4 with a length of 4 (mm) in the y-axis direction is 0.07 Ω, and the resistance of the resistor 7 connected to this wiring 4 via the second metal electrode 5 is 4000 Ω. Also, the resistance of the first metal wiring 4 with a length of 8 (mm) in the y-axis direction is 0.04 Ω, and the resistance of the resistor 7 connected to this wiring 4 via the second metal electrode 5 is 8000 Ω. Also, the constant voltage power supply 8 applies a constant voltage of 5V. Changes in the current values before and after corrosion in the corrosion detection device 1 of Example A are shown in the graph of FIG. 5. The current value before corrosion is shown without a broken line and is about 7 mA. The current value when the first metal wiring 4 with a length of 1 (mm) in the y-axis direction is broken is shown with only 1 mm broken line and is about 2 mA. The current value when the first metal wirings 4 with lengths of 1 mm and 4 mm in the y-axis direction are broken is shown with 1, 4 mm broken line and is less than 1 mA. The current value when the first metal wirings 4 with lengths of 1 mm and 8 mm in the y-axis direction are broken is shown with 1, 8 mm broken line and is about 1.2 mA. The current value when the first metal wirings 4 with lengths of 4 mm and 8 mm in the y-axis direction are broken is shown with 4, 8 mm broken line and is about 5 mA. The current value when all the first metal wirings 4 are broken is shown with all broken lines and is 0 mA. Thus, the current value changes corresponding to which wiring is broken. The change in the combined resistance value due to the broken line can be calculated from the change in the current value. Thereby, the broken wiring can be specified.The corrosion resistance in the set environment of the first metal (in this case, Al) can be determined from the length of the disconnected wiring in the y-axis direction.

[0025] In FIGS. 3 to 5, an example of changing the length of the wiring 4 of the first metal in the y-axis direction was described, but the embodiment is not limited to this example. For example, the type of material of the wiring of the first metal may be changed to a plurality of types instead of one type. Also, the number of wirings of the first metal in contact with the electrode of the second metal is not limited to one, and for example, it can be made plural. It is not necessary to make the sizes of the electrodes of the second metal uniform, and they may be of a plurality of types. Instead of connecting all the wirings of the first metal to the electrode of the third metal, the electrode of the third metal may be divided into a plurality of parts, and one or a plurality of wirings of the first metal may be electrically connected to each electrode of the third metal. Also, it is not necessary to make the sizes of the cover parts uniform, and they may be of a plurality of types. Taking the type of material of the wiring of the first metal as one type, examples combining these are shown in Table 1 below as Embodiments 1 to 5. The corrosion detection device of Embodiment 1 in Table 1 corresponds to the example described with reference to FIGS. 3 to 5.

[0026] [Table 1]

[0027] (Embodiment 2) The corrosion detection device of Embodiment 2 has the same configuration as Embodiment 1 except that the number of wirings 4 of the first metal in contact with the electrode 5 of the second metal is made plural. The corrosion detection device of Embodiment 2 will be described with reference to FIG. 6. The corrosion detection device 1 of Embodiment 2 includes the wirings 4 of the first metal 1 , 4 2 , 4 3 consisting of the wirings 4 of the first metal, and the electrodes 5 of the second metal 1 , 5 2 , 5 3 consisting of the electrodes 5 of the second metal. The resistor 7 connected to one end in the x-axis direction of the electrodes 5 1 , 5 2 , 5 3 is not shown in the figure. The wirings 4 of the first metal 1 , 4 2 , 43 has the same length in the x-axis direction and the z-axis direction, while the length L y in the y-axis direction is different. Also, there are a plurality of wirings 4 1 of the first metal, 4 2 of the first metal, 4 3 of the first metal. The wirings 4 1 of the first metal, 4 2 of the first metal, 4 3 of the first metal have a length L y and are arranged at intervals from each other along one direction along the y-axis direction in descending order of the length L. The electrodes 5 1 of the second metal, 5 2 of the second metal, 5 3 of the second metal have the same length in the x-axis direction and the y-axis direction respectively. The electrodes 5 1 of the second metal, 5 2 of the second metal, 5 3 of the second metal are arranged at intervals from each other along the above-mentioned one direction. The plurality of wirings 4 1 of the first metal have the other ends in the x-axis direction of the electrodes 5 1 of the second metal overlapped with one ends in the x-axis direction of each of them. As a result, the plurality of wirings 4 1 of the first metal are connected in parallel to the electrodes 5 1 of the second metal. The plurality of wirings 4 2 of the first metal have the other ends in the x-axis direction of the electrodes 5 2 of the second metal overlapped with one ends in the x-axis direction of each of them. As a result, the plurality of wirings 4 2 of the first metal are connected in parallel to the electrodes 5 2 of the second metal. Also, the plurality of wirings 4 3 of the first metal have the other ends in the x-axis direction of the electrodes 5 3 of the second metal overlapped with one ends in the x-axis direction of each of them. As a result, the plurality of wirings 4 3 of the first metal are connected in parallel to the electrodes 5 3 of the second metal.

[0028] In the opening 10a of the cover portion 10, there are the wirings 4 1 of the first metal, 4 2 of the first metal, 4 3 of the first metal and the electrodes 5 1 of the second metal, 5 2 of the second metal, 5 3The connection part and its vicinity are located there. Therefore, the connection part and its vicinity will be exposed to the set environment through the opening 10a. Also, parts other than the above connection part, for example, the wiring 4 of the first metal 1 , 4 2 , 4 3 , the connection part between the other end in the x-axis direction of 4 and the electrode 6 of the third metal, the electrode 5 of the second metal 1 , 5 2 , 5 3 , the one end in the x-axis direction of 5, etc. are covered by the cover part 10. Therefore, these parts can be prevented from being exposed to the set environment.

[0029] FIG. 7 shows a schematic diagram of the circuit diagram of the corrosion detection device 1 of Embodiment 2. In FIG. 7, the illustration of the electrode 5 of the second metal 1 , 5 2 , 5 3 is omitted. Let the lengths in the y-axis direction of the wirings 4 of the first metal 1 , 4 2 , 4 3 be a (mm), b (mm), c (mm), respectively. Also, let the resistances of the wirings 4 of the first metal 1 , 4 2 , 4 3 be r 1 Ω, r 2 Ω, r 3 Ω, respectively. Let the resistances of the resistors 7 electrically connected to the electrodes 5 of the second metal 1 , 5 2 , 5 3 be R 1 Ω, R 2 Ω, R 3 Ω, respectively. Let the current value of the circuit shown in FIG. 7 be I ini1 (A), and the voltage value be V (V). The current value I ini1 is represented by the product of the combined resistance calculated from r 1 Ω, r 2 Ω, r 3 Ω, R 1 Ω, R 2 Ω, and R 3 Ω, and the voltage value V.

[0030] In the corrosion detection device 1 of Embodiment 2, schematic diagrams of circuit diagrams and current values when a disconnection occurs in the wiring 4 of the first metal are shown in FIGS. 9 to 12. In FIGS. 9 to 12, members similar to those in FIG. 7 are denoted by the same reference numerals, and the description thereof is omitted.

[0031] In the corrosion detection device 1 of Embodiment 2, for example, as shown in FIG. 9, assume that one of the three wirings 4 of the first metal 1 is disconnected. The combined resistance of the wiring 4 of the first metal 1 is the sum of the combined resistances of the remaining two wirings 4 1 and 1 / r 1 and 1 / r 1 . The current value I ini2 in this case is expressed by an equation similar to the equation shown in FIG. 8, except that the combined resistance of the wiring 4 of the first metal 1 is different.

[0032] Also, in the corrosion detection device 1 of Embodiment 2, for example, as shown in FIG. 11, assume that all of the wirings 4 of the first metal 1 are disconnected. In this case, the combined resistance of the wiring 4 of the first metal and the resistor 7 is the combined resistance of the remaining wiring 4 2 , 4 3 and the resistor 7 electrically connected to each wiring 4 2 , 4 3 . The current value I ini3 is expressed by the equation shown in FIG. 12 as the product of the combined resistance calculated from r 2 Ω, r 3 Ω, R 2 Ω, and R 3 Ω and the voltage value V.

[0033] As is clear from the comparison of the current values I ini1、 I ini2 and I ini3 calculated from the equations shown in FIGS. 8, 10, and 12 respectively, when the current value I ini1 before corrosion is used as a reference, the change amount of the current value I 1 when all of the wirings 4 of the first metal are disconnected is the current value I ini3 when one of the wirings 4 of the first metal is disconnected 1 and the current value I ini2is larger than the amount of change. Therefore, it becomes easier to detect the amount of current change due to corrosion, and measurement variations can be suppressed. As a specific example of Embodiment 2, the corrosion detection device 1 of Example B will be described with reference to FIGS. 13 to 14.

[0034] (Corrosion Detection Device 1 of Example B) As shown in the schematic circuit diagram shown in FIG. 13, the wiring 4 of the first metal 1 , 4 2 , 4 3 is an Al wiring, respectively. The material of the electrode 5 of the second metal is, for example, Cu. The material of the electrode 6 of the third metal is, for example, Cu. The wiring 4 of the first metal 1 , 4 2 , 4 3 has a constant length of 5 mm in the x-axis direction and a constant length of 5 nm in the z-axis direction, respectively. The length L 1 , 4 2 , 4 3 of the wiring 4 of the first metal in the y-axis direction y is 1 (mm), 4 (mm), and 8 (mm), respectively. Also, the resistance of the wiring 4 of the first metal 1 , 4 2 , 4 3 is 0.28 Ω, 0.07 Ω, and 0.04 Ω, respectively. The resistance of the resistor 7 electrically connected to each of the electrodes 5 1 , 5 2 , 5 3 is 8000 Ω, 4000 Ω, and 1000 Ω, respectively. The current value I ini1 (A) of the circuit shown in FIG. 13 is calculated from the formula shown in FIG. 8.

[0035] In the environment where the corrosion detection device is installed, there may appear points where the amount of chlorine or moisture locally increases due to repeated drying and wetting or dew condensation. The fluctuations in the amount of chlorine or moisture may affect the corrosion of the wiring of the first metal. For example, in the corrosion detection device 1 described with reference to FIG. 13, when there is almost no influence due to environmental changes, it is expected that the wiring 4 of the first metal with a length L y of 1 mm will corrode first. Points where the amount of chlorine or moisture locally increases 1 where the length Ly When it occurs on the side of the wiring 4 of the first metal with a length of 4 mm 2 of the wiring 4 of the first metal 2 the wiring 4 1 may corrode earlier than the wiring 4. By increasing the number of wirings of the first metal, even if one wiring is disconnected due to a problem such as environmental fluctuations, the measurement can be continued with the remaining wirings, so it is possible to reduce the measurement variation.

[0036] The wiring 4 of the first metal 1 4 2 4 3 shows the location of the disconnection due to corrosion and the change in the current value in FIG. 14. In FIG. 14, the horizontal axis indicates the location of the disconnection, and the vertical axis indicates the current value (mA). The wiring 4 of the first metal 1 4 2 4 3 where none of them are disconnected is indicated as "no disconnection", and the current value without disconnection is about 7 mA. The length L y When one of the wirings 4 of the first metal with a length of 1 mm 1 is disconnected, it is indicated as "1 mm 1 disconnection", and when two are disconnected, it is indicated as "1 mm 2 disconnections". In either case, the current value is almost the same as that without disconnection, about 7 mA. The wiring 4 of the first metal 1 when all are disconnected is indicated as "1 mm all disconnections", and the current value when all are disconnected is about 6 mA. As indicated by the arrow 21 in FIG. 14, the change amount (decrease amount) of the current value when all are disconnected is larger than when 1 mm is disconnected by 1 or 2.

[0037] The length L y When one of the wirings 4 of the first metal with a length of 4 mm 2 is disconnected, it is indicated as "4 mm 1 disconnection", and when two are disconnected, it is indicated as "4 mm 2 disconnections". In either case, the current value is almost the same as that without disconnection, about 7 mA. The wiring 4 of the first metal 2 when all are disconnected is indicated as "4 mm all disconnections", and the current value when all are disconnected is about 5.5 mA. As indicated by the arrow 22 in FIG. 14, the change in the current value is larger than when all are disconnected by 1 mm. Also, the length L y8mm of the first metal wiring 4 3 When one of the wires is broken, it is indicated as "8mm 1 wire broken" and when two wires are broken, it is indicated as "8mm 2 wire broken". In either case, the current value is about 7mA, which is almost the same as when there is no break. 3 When the entire 8 mm length is broken, the current value is about 2 mA, which is a larger change in current value than when the entire 4 mm length is broken, as shown by arrow 23 in FIG.

[0038] In addition, the first metal wiring 4 1 , 4 2 When all of the wires are broken, this is indicated as "1.4 mm all broken." When all of the wires are broken, the current is about 5 mA. 1 , 4 3 When all of the wires are broken, the current is about 1.2 mA. 2 , 4 3 When all of the wires are broken, the current is about 0.7 mA. 1 , 4 2 , 4 3 When all of the terminals are broken, this is indicated as "all broken", and the current value when all of them are broken is 0 mA.

[0039] As explained above, the length L y 4 different first metal wiring 1 , 4 2 , 4 3 By having multiple y-axis lengths, the length L y This reduces the fluctuation in current value when one of the first metal wirings with equal y-axis length is disconnected due to some kind of defect, and allows measurement to continue using the remaining wiring. As a result, the effects of the length of the first metal wiring in the y-axis direction and the type of metal material on the corrosion reaction can be properly evaluated, and measurement variability can be suppressed.

[0040] (Embodiment 3) The corrosion detection device 1 of Embodiment 3 has the same configuration as that of Embodiment 1, except that the length of the wiring 4 of the first metal in the y-axis direction is made uniform, the sizes of the electrodes 5 of the second metal that are in contact with the wiring 4 of the first metal are made different, and the shapes of the openings of the cover portion 10 are made different. The corrosion detection device 1 of Embodiment 3 will be described with reference to FIG. 15. The corrosion detection device 1 of Embodiment 3 includes the wiring 4 of the first metal 4 、4 5 、4 6 comprising the wiring 4 of the first metal, and a plurality of electrodes 5 of the second metal having different areas from each other 4 、5 5 、5 6 comprising the electrodes 5 of the second metal. The plurality of wirings 4 of the first metal 4 、4 5 、4 6 have the same dimensions. In other words, the plurality of wirings 4 of the first metal 4 、4 5 、4 6 have the same lengths in the x-axis direction, y-axis direction, and z-axis direction respectively between the wirings. The resistors 7 connected to one ends in the x-axis direction of the plurality of electrodes 5 of the second metal 4 、5 5 、5 6 are not shown in the figure. The wirings 4 of the first metal 4 、4 5 、4 6 are arranged at intervals along one direction 100 along the y-axis direction. The electrodes 5 of the second metal 4 、5 5 、5 6 have different areas from each other. Specifically, the electrodes 5 of the second metal 4 、5 5 、5 6 have the same length in the y-axis direction and different lengths in the x-axis direction. The electrodes 5 of the second metal 4 、5 5 、5 6 are arranged at intervals along the one direction 100 of the y-axis in order from the one with the shorter length in the x-axis direction. The other end in the x-axis direction of the electrode 5 of the second metal 4 is overlapped with one end in the x-axis direction of the wiring 4 of the first metal 4 . Thereby, the wiring 4 of the first metal4 is connected in series to the electrode 5 of the second metal. 4 The wiring 4 of the first metal 5 has one end in the x-axis direction overlapped with the other end in the x-axis direction of the electrode 5 of the second metal. 5 As a result, the wiring 4 of the first metal 5 is connected in series to the electrode 5 of the second metal. 5 Also, one end in the x-axis direction of the wiring 4 of the first metal 6 has the other end in the x-axis direction of the electrode 5 of the second metal overlapped therewith. 6 As a result, the wiring 4 of the first metal 5 is connected in series to the electrode 5 of the second metal. 6

[0041] The cover part 10 is provided with openings 10b to 10d. The openings 10b to 10d have the same length in the y-axis direction and also have the same length in the x-axis direction. In the opening 10b, the connection part between the wiring 4 of the first metal 4 and the electrode 5 of the second metal 4 is located. In the opening 10c, the connection part between the wiring 4 of the first metal 5 and the electrode 5 of the second metal 5 is located. In the opening 10d, the connection part between the wiring 4 of the first metal 6 and the electrode 5 of the second metal 6 is located. In the openings 10b to 10d, the surfaces along the xy plane of the electrodes 5 4 of the second metal, 5 5 of the second metal, 5 6 and a part of each of the wirings 4 4 of the first metal, 4 5 of the first metal, 4 6 are located. Here, since the areas of the wirings 4 4 of the first metal, 4 5 of the first metal, 4 6 exposed to the outside through the openings 10b to 10d are equal, the areas of the electrodes 5 4 of the second metal, 5 5 of the second metal, 5 6 exposed to the outside through the openings 10b to 10d determine the areas of the wirings 4 4 of the first metal, 4 5 of the first metal, 4 6The corrosion rates are different. The exposed area is the largest for the electrode 5 of the second metal 6 That is why the electrode 5 of the second metal 6 and the wiring 4 of the first metal in contact therewith 6 is more likely to corrode than the other wirings 4 4 、4 5 . By detecting the change in the current value caused by the disconnection due to corrosion, the change in the combined resistance before and after corrosion is obtained, and it is determined which of the wirings 4 of the first metal 4 、4 5 、4 6 has been disconnected. By comparing the time until the disconnection of the wirings 4 of the first metal 4 、4 5 、4 6 , the corrosion resistance of the wirings 4 of the first metal in the set environment 4 、4 5 、4 6 can be determined.

[0042] (Embodiment 4) The corrosion detection device 1 of Embodiment 4 has the same configuration as that of Embodiment 1 except that it includes electrodes 6 of a third metal as electrodes 6 of a third metal 1 ~6 7 . The corrosion detection device 1 of Embodiment 4 will be described with reference to FIG. 16. The electrodes 6 of the third metal 1 ~6 7 have a shape extending along the x-axis direction. The electrodes 6 of the third metal 1 ~6 7 have, for example, a strip shape or a rectangular strip shape. The electrodes 6 of the third metal 1 ~6 7 are each electrically connected to the other end of the wiring 4 of the first metal in the x-axis direction. The electrodes 6 of the third metal 1 ~6 7 are arranged at intervals from each other in one direction in the y-axis direction. The other configurations are the same as those of the corrosion detection device 1 of Embodiment 1 described with reference to FIGS. 1 to 3.

[0043] A plurality of electrodes 6 made of a third metal are prepared and each is electrically connected to the wiring 4 made of a first metal, so that the current can be measured for each wiring 4 made of the first metal. Therefore, even if a measurement error occurs due to some problem, the disconnected wiring can be surely identified. As a result, the measurement accuracy of the corrosion detection device 1 can be improved.

[0044] (Embodiment 5) The corrosion detection device 1 according to Embodiment 5 has the same configuration as that of Embodiment 1, except that the length of the wiring 4 made of the first metal in the y-axis direction is made uniform, and the cover portion 10 is provided with a plurality of openings 10e to 10g having different sizes. The corrosion detection device 1 according to Embodiment 5 will be described with reference to FIG. 17. The corrosion detection device 1 according to Embodiment 5 includes a plurality of wirings 4 made of a first metal having constant lengths in the x-axis, y-axis, and z-axis directions 4 、4 5 、4 6 and a plurality of electrodes 5 made of a second metal having the same area 7 、5 8 、5 9 . The resistor 7 connected to one end (the end located on the right side in FIG. 17) of the first direction 200 (parallel to the x-axis direction) of the electrode 5 made of the second metal 7 、5 8 、5 9 is not shown. The wirings 4 made of the first metal 4 、4 5 、4 6 are arranged at intervals along one direction 100 along the y-axis direction. The electrodes 5 made of the second metal 7 、5 8 、5 9 have the same length in the y-axis direction and the same length in the x-axis direction. The electrodes 5 made of the second metal 7 、5 8 、5 9 are arranged at intervals along the one direction 100 of the y-axis. One end (the end located on the right side in FIG. 17) of the first direction 200 (parallel to the x-axis direction) of the wiring 4 made of the first metal 4 is connected to the electrode 5 made of the second metal 7 ​​​​​​The other end of the first direction 200 (parallel to the x-axis direction) (the end located on the left side in FIG. 17) is overlapped. Thereby, the wiring 4 of the first metal 4 is connected in series to the electrode 5 of the second metal 7 . One end of the wiring 4 of the first metal in the first direction 200 (parallel to the x-axis direction) overlaps with the other end of the electrode 5 of the second metal 5 in the first direction 200 (parallel to the x-axis direction). Thereby, the wiring 4 of the first metal 8 is connected in series to the electrode 5 of the second metal 5 . Also, one end of the wiring 4 of the first metal in the first direction 200 (parallel to the x-axis direction) overlaps with the other end of the electrode 5 of the second metal 8 in the first direction 200 (parallel to the x-axis direction). Thereby, the wiring 4 of the first metal 6 is connected in series to the electrode 5 of the second metal 9 in the first direction 200 (parallel to the x-axis direction). Thereby, the wiring 4 of the first metal 6 is connected in series to the electrode 5 of the second metal 9 .

[0045] The cover part 10 is provided with openings 10e to 10g. The lengths of the openings 10e to 10g in the y-axis direction are constant. The lengths of the openings 10e to 10g in the x-axis direction are different from each other. The openings 10e to 10g are arranged along one direction 100 of the y-axis in order from the one with the shorter length in the x-axis direction. Therefore, the opening areas of the openings 10e to 10g increase in the order of the opening 10e, the opening 10f, and the opening 10g. In the opening 10e, the connection part between the wiring 4 of the first metal 4 and the electrode 5 of the second metal 7 is located. In the opening 10f, the connection part between the wiring 4 of the first metal 5 and the electrode 5 of the second metal 8 is located. In the opening 10g, the connection part between the wiring 4 of the first metal 6 and the electrode 5 of the second metal 9 is located. In the openings 10e to 10g, the surfaces along the xy planes of the electrodes 5 of the second metal 7 , 5 8 , 5 9 and parts of the wirings 4 of the first metal 4 , 4 5 , 4 6 are exposed respectively. The wiring 4 of the first metal4 , 4 5 , 4 6 The areas of 4 exposed to the outside through the openings 10e to 10g are equal. On the other hand, for the second metal electrodes 5 7 , 5 8 , 5 9 The areas of 5 exposed to the outside through the openings 10e to 10g are, in the order of the second metal electrodes 5 7 , 5 8 , 5 9 , 5 9 increasing. Therefore, the first metal wiring 4 in contact with the second metal electrode 5 6 is more likely to corrode than the other wirings 4 4 , 4 5 . By detecting the change in the current value caused by the disconnection due to corrosion, the first metal wirings 4 4 , 4 5 , 4 6 can be compared until they are disconnected. As a result, the corrosion resistance of the first metal wirings 4 4 , 4 5 , 4 6 in the set environment can be determined.

[0046] (Embodiment 6) In Embodiments 1 to 5, the materials of the first metal wirings 4 were made the same, but the materials of the first metal wirings 4 may be different. The corrosion detection device 1 of Embodiment 6 will be described with reference to FIGS. 18 to 20. In FIGS. 18 to 20, the same members as those described in FIGS. 1 to 17 are denoted by the same reference numerals and the description thereof is omitted. FIG. 18 shows an example of the circuit diagram and current value before corrosion and the circuit diagram and current value after corrosion of the corrosion detection device 1. In the example shown in FIG. 18, the first metal wirings 4 are different from each other in material. The first metal wirings 4 are composed of, for example, a wiring 4 of metal A, a wiring 4 of metal B, and a wiring 4 of metal C. The length of each wiring 4 in the x-axis direction is constant, and the length in the y-axis direction is also constant, for example, a (mm). Let the resistance of the wiring 4 of metal A be r 1 Ω, and let the resistance of the resistor 7 connected to this wiring 4 via the second metal electrode 5 be R 1 Ω. Let the resistance of the wiring 4 of metal B be r 2 Ω, and let the resistance of the resistor 7 connected to this wiring 4 via the second metal electrode 5 be R2 Let it be Ω. Also, let the resistance of the wiring 4 of metal C be r 3 Ω, and let the resistance of the resistor 7 connected to this wiring 4 via the electrode 5 of the second metal be R 3 Ω. Let the current value of the circuit before corrosion be I ini (A), and let the voltage value be V (V). The current value I of the circuit before corrosion ini is, as shown in Fig. 18, r 1 Ω, r 2 Ω, r 3 Ω, R 1 Ω, R 2 Ω and R 3 Ω, and is represented by the product of the combined resistance calculated from and the voltage value V

[0047] Suppose that, due to corrosion, for example, the wiring 4 of metal A is disconnected. As a result, the combined resistance of the wiring 4 of the first metal and the resistor 7 in the circuit after corrosion is r 2 Ω, r 3 Ω, R 2 Ω and R 3 Ω, and is calculated from. Therefore, the current value I of the circuit after corrosion corr is, as shown in Fig. 18, r 2 Ω, r 3 Ω, R 2 Ω and R 3 Ω, and is represented by the product of the combined resistance calculated from and the voltage value V

[0048] Since a constant voltage V is applied to the circuit, by comparing the current value I of the circuit before corrosion ini with the current value I of the circuit after corrosion corr , it is possible to detect the change in the combined resistance of the wiring 4 of the first metal and the resistor 7 due to corrosion. As a result, it is possible to identify which of the wirings 4 in the wiring 4 of the first metal has been disconnected. Therefore, it is possible to determine the type of the first metal that is likely to be corroded in the set environment

[0049] (Corrosion detection device 1 of Example C in Embodiment 6) The corrosion detection device 1 of Example C, which is a specific example of the detection method described with reference to FIG. 18, will be described with reference to FIGS. 19 and 20. FIG. 19 is a diagram showing an outline of the circuit diagram of the corrosion detection device 1 of Example C. FIG. 20 is a graph showing the change in the current value before and after corrosion of the corrosion detection device 1 of Example C. The wiring 4 of the first metal is composed of, for example, an Fe wiring as the A metal wiring, an Al wiring as the B metal wiring, and a Ti wiring as the C metal wiring. The material of the electrode 5 of the second metal is, for example, Cu. The material of the electrode 6 of the third metal is, for example, Cu. Each wiring 4 has a length of 5 mm in the x-axis direction, a length of 4 mm in the y-axis direction, and a length of 5 nm in the z-axis direction. The resistance of the Fe wiring 4 is 0.25 Ω, and the resistance of the resistor 7 connected to this wiring 4 via the electrode 5 of the second metal is 1000 Ω. The resistance of the Al wiring 4 is 0.07 Ω, and the resistance of the resistor 7 connected to this wiring 4 via the electrode 5 of the second metal is 4000 Ω. Also, the resistance of the Ti wiring 4 is 1.05 Ω, and the resistance of the resistor 7 connected to this wiring 4 via the electrode 5 of the second metal is 8000 Ω. Also, the constant voltage power supply 8 applies a constant voltage of 5V. The change in the current value before and after corrosion in the corrosion detection device 1 of Example C is shown in the graph of FIG. 20. The current value before corrosion is shown without a broken line and is about 7 mA. The current value when the Al wiring 4 is disconnected is shown as only Al disconnected and is about 5.5 mA. The current value when the Ti wiring 4 is disconnected is shown as only Ti disconnected and is about 2 mA. The current value when the Fe wiring 4 is disconnected is shown as only Fe disconnected and is about 6 mA. The current value when the Al wiring and the Ti wiring are disconnected is shown as Al and Ti disconnected and is about 5 mA. The current value when the Al wiring and the Fe wiring are disconnected is shown as Al and Fe disconnected and is less than 1 mA. The current value when the Ti wiring and the Fe wiring are disconnected is shown as Ti and Fe disconnected and is about 1.2 mA. Thus, since the combined resistance changes depending on which wiring is disconnected and the current value changes, the disconnected wiring can be specified. Therefore, it is possible to determine the type of the first metal that is likely to be corroded in the set environment.

[0050] (Embodiment 7) In Embodiments 1 to 6, an example in which a resistor 7 is connected to the electrode 5 of the second metal has been described, but the embodiment is not limited to this example. The corrosion detection device may not include a resistor. The corrosion detection device 1 of Embodiment 7 will be described with reference to FIGS. 21 to 23. FIG. 21 shows an example of the circuit diagram and current value before corrosion and the circuit diagram and current value after corrosion of the corrosion detection device 1. The wirings 4 of the plurality of first metals are formed of the same type of metal. The wiring 4 of the first metal has a constant length in the x-axis direction and a constant length in the z-axis direction respectively. The lengths in the y-axis direction are different from each other as a (mm), b (mm), and c (mm). Let the resistance of the wiring 4 of the first metal with a length of a (mm) in the y-axis direction be r 1 Ω. Let the resistance of the wiring 4 of the first metal with a length of b (mm) in the y-axis direction be r 2 Ω. Also, let the resistance of the wiring 4 of the first metal with a length of c (mm) in the y-axis direction be r 3 Ω. The electrodes 5 of the second metal in contact with each of these wirings 4 are connected in parallel to a constant voltage power supply 8 without passing through the resistor 7. Let the current value of the circuit before corrosion be I ini (A), and the voltage value be V (V). The current value I ini of the circuit before corrosion is, as shown in FIG. 21, the product of the combined resistance calculated from r 1 Ω, r 2 Ω, r 3 Ω and the voltage value V.

[0051] Suppose that, due to corrosion, for example, the wiring 4 of the first metal with a length of a (mm) in the y-axis direction is disconnected. As a result, the combined resistance of the wiring 4 of the first metal in the circuit after corrosion is calculated from r 2 Ω, r 3 Ω. Therefore, the current value I corr of the circuit after corrosion is, as shown in FIG. 21, the product of the combined resistance calculated from r 2 Ω, r 3 Ω and the voltage value V.

[0052] Since a constant voltage V is applied to the circuit, the current value I ini of the circuit before corrosion and the current value I corrBy comparing them, it is possible to detect changes in the combined resistance of the wiring 4 of the first metal due to corrosion. As a result, it is possible to identify which of the wirings 4 of the first metal has broken. From the length of the broken wiring 4 of the first metal in the y-axis direction, the corrosion resistance of the wiring 4 of the first metal in the set environment can be determined.

[0053] (Corrosion detection device 1 of Example D in Embodiment 7) The corrosion detection device 1 of Example D, which is a specific example of the detection method described with reference to FIG. 21, will be described with reference to FIGS. 22 and 23. FIG. 22 is a circuit diagram of the corrosion detection device 1 of Example D. FIG. 23 is a graph showing changes in current values before and after corrosion of the corrosion detection device 1 of Example D. The materials of the plurality of wirings 4 of the first metal are, for example, made uniform in the same type. The length of each wiring 4 of the first metal in the x-axis direction is constant at 5 mm, and the length in the z-axis direction is constant at 5 nm. The lengths in the y-axis direction are 1 (mm), 4 (mm), and 8 (mm). The wirings 4 of the first metal are arranged in ascending order of the length in the y-axis direction along one direction of the y-axis. The resistance of the wiring 4 of the first metal with a length of 1 (mm) in the y-axis direction is r 1 Ω. The resistance of the wiring 4 of the first metal with a length of 4 (mm) in the y-axis direction is r 2 Ω. Also, the resistance of the wiring 4 of the first metal with a length of 8 (mm) in the y-axis direction is r 3It is as follows. The electrode 5 of the second metal is in contact with the wiring 4 of each first metal, and the electrode 5 of the second metal is connected in parallel to the constant voltage power supply 8. The constant voltage power supply 8 applies a constant voltage of 5V. The change in the current value before and after corrosion in the corrosion detection device 1 of Example D is shown in the graph of FIG. 23. The current value before corrosion is shown without a broken line and is about 230 mA. The current value when the wiring 4 of the first metal with a length of 1 (mm) in the y-axis direction is broken is shown with a broken line only for 1 mm and is about 210 mA. The current value when the wirings 4 of the first metal with lengths of 1 mm and 4 mm in the y-axis direction are broken is shown with broken lines for 1 and 4 mm and is about 140 mA. The current value when the wirings 4 of the first metal with lengths of 1 mm and 8 mm in the y-axis direction are broken is shown with broken lines for 1 and 8 mm and is about 70 mA. The current value when the wirings 4 of the first metal with lengths of 4 mm and 8 mm in the y-axis direction are broken is shown with broken lines for 4 and 8 mm and is about 20 mA. The current value when all the wirings 4 of the first metal are broken is shown with all broken lines and is 0 mA. Thus, since the combined resistance changes depending on which wiring is broken and the current value changes, the broken wiring can be specified. As a result, the corrosion resistance of the wiring 4 of the first metal in the set environment can be determined.

[0054] According to the corrosion detection device of the first embodiment described above, there are a plurality of wirings of a first metal having a shape extending along a first direction and including a metal to be detected, an electrode of a second metal that contacts one end portion of each wiring of the first metal in the first direction and includes a metal nobler than the metal to be detected, an electrode of a third metal that contacts the other end portion of each wiring of the first metal in the first direction, and a moisture-proof cover portion that covers at least a part of the wiring of the first metal, the electrode of the second metal, and the electrode of the third metal, and has an opening at the contact portion between the wiring of the first metal and the electrode of the second metal. According to the corrosion detection device of the embodiment, since the contact portion between the wiring of the first metal and the electrode of the second metal is exposed to the external measurement environment through the opening of the moisture-proof cover portion, corrosion (for example, dissimilar metal corrosion) can be caused at the contact portion. By detecting the resistance change associated with the disconnection caused thereby as a current value, the wiring of the first metal where the disconnection has occurred can be specified. As a result, since the corrosion resistance of the first metal in the installation environment can be surely determined, it becomes possible to utilize the determination result not only for the maintenance of the product using the first metal but also for the design of the product using the first metal. Further, since the change in the current value associated with the disconnection due to corrosion is detected instead of the amount of corrosion, even for a first metal having a tendency of a small amount of corrosion, for example, Al, the corrosion resistance in the installation environment can be determined. (Second Embodiment) The second embodiment relates to a corrosion state determination system. The corrosion state determination system includes the corrosion detection device of the first embodiment. An embodiment of the corrosion state determination system will be described with reference to FIGS. 24 and 25. FIG. 24 is a block diagram showing an outline of the corrosion state determination system of the embodiment. FIG. 25 is a flowchart showing the flow of a determination method using the corrosion state determination system shown in FIG. 24. As shown in FIG. 24, the corrosion state determination system 101 includes a corrosion detection device 1, a power supply (for example, a constant voltage power supply) 8, an ammeter 9, a control device 30, a storage medium 31, a communication device 32, and a display 33. Since the corrosion detection device 1, the constant voltage power supply 8, and the ammeter 9 have the same configuration as that of the first embodiment described with reference to FIGS. 1 and 2, the description thereof will be omitted. The control device 30 is connected to the constant voltage power supply 8 by a wiring 34. Further, the control device 30 is connected to the ammeter 9, the storage medium 31, the communication device 32, and the display 33 as a display device by wirings 35, 36, 37, and 38, respectively.

[0055] The control device 30 determines the corrosion state in the corrosion detection device 1 based on the current value measured by the ammeter 9. Specifically, the measured current value is compared with a reference current value calculated using the combined resistance value of the wiring 4 of the plurality of first metals and the voltage value of the constant voltage power supply 8. The reference current value is, for example, a value calculated using the combined resistance value of the wiring of the first metal and the voltage value of the constant voltage power supply for the current value in the circuit when a disconnection occurs. As an example of the reference current value, I described in FIG. 3 corr and I described in FIG. 10 ini2 and I described in FIG. 12 ini3、 and I described in FIG. 18 corr and 、 and I described in FIG. 21 corrExamples include the like. Also, as is clear from the graphs of FIGS. 5, 14, 20, and 23, the reference current value differs for each wiring 4 of the first metal where a disconnection has occurred. The reference current value for each wiring 4 of the first metal where a disconnection has occurred is stored in the storage medium 31 as a database. The control device 30 selects the reference current value closest to the measured current value and determines that the disconnection condition of the selected reference current value is a corrosion state. The control device 30 is composed of, for example, a CPU or the like. The data (signal) indicating the corrosion state determined by the control device 30 is transmitted to the storage medium 31 through the wiring 36.

[0056] The storage medium 31 stores data indicating the corrosion state determined by the control device 30. Also, in the storage medium 31, the above-mentioned database, the pre-corrosion current value of the corrosion detection device 1, information regarding the wiring 4 of the first metal of the corrosion detection device 1 (for example, dimensions, material, resistance value, etc.), the resistance value of the resistor 7, etc. are stored in advance. The storage medium 31 is, for example, a memory.

[0057] The communication device 32 transmits the corrosion state determined by the control device 30 to the outside. The transmission may be performed either by wire or wirelessly. The transmission destination is, for example, a device different from the corrosion detection device 1.

[0058] The display 33 is an example of a display device that displays the determination result by the control device 30.

[0059] An example of the corrosion state determination by the corrosion state determination system 101 will be described with reference to FIG. 25. As shown in FIG. 25, the method of the embodiment includes steps S1 to S11.

[0060] (Step S1) Turn on (operate) the control device 30.

[0061] (Step S2) In the control device 30, set the sampling conditions. The sampling conditions are the conditions for performing corrosion detection. Examples of the sampling conditions include the sampling interval (measurement interval), the output value (voltage) of the constant voltage power supply 8, etc.

[0062] (Step S3) Start sampling (corrosion detection).

[0063] (Step S4) Turn on the power supply for current measurement. The power supply for current measurement is, for example, a constant voltage power supply 8 or the like. The power supply for current measurement is turned on, for example, by receiving an output (signal) from the control device 30.

[0064] (Step S5) Measure the current value. The measurement of the current value is performed by the ammeter 9. The measured current value is stored in the storage medium 31.

[0065] (Step S6) Turn off the constant voltage power supply 8 which is the power supply for current measurement. The power supply for current measurement is turned off, for example, by receiving an output (signal) from the control device 30.

[0066] (Step S7) Determine the disconnection point. The determination is performed by the control device 30. The control device 30 compares the reference current value in the database read from the storage medium 31 with the current value measured in Step S5 (hereinafter referred to as the measured value) to determine the corrosion of the wiring 4 of the first metal. The reference current value and the measured value are read from the storage medium 31 by the output from the control device 30 and compared by the control device 30. The determination result (signal) is transmitted from the control device 30 to the display 33 through the wiring 38 and displayed on the display 33.

[0067] (Step S8) The determination result is stored. The determination result (signal) is transmitted from the control device 30 to the storage medium 31 through the wiring 36 and stored in the storage medium 31.

[0068] (Step S9) The stored determination result is transmitted externally. When the output from the control device 30 is transmitted to the communication device 32 through the wiring 37, the determination result (signal) is transmitted externally (for example, to an external device or the like) by the communication device 32.

[0069] (Step S10) Sampling is completed. The output from the control device 30 is transmitted to the power supply 8, the communication device 32, and the display 33, and the corrosion state determination system 101 shifts to the standby state.

[0070] (Step S11) The corrosion state determination system 101 enters the standby state. The standby period is a period determined by the sampling interval set in Step S2. The standby is released by the output from the control device 30. When the standby is released, it resumes from the start of sampling in Step S3. A series of steps from Step S3 to Step S11 are repeated until the sampling conditions set in Step S2 are reached.

[0071] According to the corrosion state determination system of the second embodiment described above, since it is provided with the corrosion detection device of the embodiment, the corrosion state of the wiring of the first metal under the set conditions can be determined from the current value. As a result, it becomes possible to determine the corrosion resistance of the first metal under the set conditions.

[0072] According to the corrosion detection device of at least one of these embodiments or examples, there are a plurality of wirings of a first metal having a shape extending along a first direction and including a metal to be detected, a second metal electrode that contacts one end portion of each wiring of the first metal in the first direction and includes a metal nobler than the metal to be detected, a third metal electrode that contacts the other end portion of each wiring of the first metal in the first direction, and a moisture-proof cover portion that covers at least a part of the wiring of the first metal, the second metal electrode, and the third metal electrode and has an opening at the contact portion between each wiring of the first metal and the second metal electrode. As a result, since the resistance change associated with disconnection due to corrosion (for example, dissimilar metal corrosion) of the contact portion can be detected by the current value, the wiring of the first metal where the disconnection has occurred can be specified. Therefore, since the corrosion resistance of the first metal in the installation environment can be surely determined, it becomes possible to utilize the determination result not only for the maintenance of products using the first metal but also for the design of products using the first metal.

[0073] Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalent scope thereof.

Explanation of Reference Numerals

[0074] 1…Corrosion detection device, 2…First substrate, 2a…Main surface of the first substrate, 3…Second substrate, 3a…Main surface of the second substrate, 4, 4n, 4m, 4 1 ~4 6 …Wiring of the first metal, 4a…One end of the wiring of the first metal, 4b…The other end of the wiring of the first metal, 5, 5 1 ~5 9 …Electrode of the second metal, 5a…One end of the electrode of the second metal, 5b…The other end of the electrode of the second metal, 6, 6 1 ~6 7 …Electrode of the third metal, 7…Resistor, 8…Power supply, 9…Ammeter, 10…Moisture-proof cover part, 10a~10g…Openings, 11, 12, 34, 35, 36, 37, 38…Wiring, 21, 22, 23…Arrows, 30…Control device, 31…Storage medium, 32…Communication device, 33…Display, 100…One direction of the y-axis, 101…Corrosion state determination system, 200…First direction.

Claims

1. a substrate; a plurality of wirings of a first metal provided on the substrate, having a shape extending along a first direction and containing a metal to be detected; a second-metal electrode provided on the substrate, contacting one end portion of each of the wirings of the first metal in the first direction and containing a metal nobler than the metal to be detected; a third-metal electrode provided on the substrate, contacting the other end portion of each of the wirings of the first metal in the first direction; a corrosion detection device including a moisture-proof cover portion covering at least a part of the wirings of the first metal, the second-metal electrode, and the third-metal electrode, and having an opening at a contact portion between each of the wirings of the first metal and the second-metal electrode.

2. The corrosion detection device according to claim 1, wherein there are a plurality of lengths in a direction intersecting the first direction in the plurality of wirings of the first metal.

3. The corrosion detection device according to claim 1, wherein there are a plurality of types of the metal to be detected in the plurality of wirings of the first metal.

4. The corrosion detection device according to claim 2 or claim 3, further including a plurality of the second-metal electrodes, each of the second-metal electrodes contacting one end portion of each of the wirings of the first metal in the first direction without being electrically connected to each other.

5. The metal to be detected in the plurality of wirings of the first metal is a metal group mainly composed of at least one element selected from the group consisting of Fe, Al, Ti, Mg, Sn, and Pb, and the metal nobler than the metal to be detected in the second-metal electrode is a metal group mainly composed of at least one element selected from the group consisting of Au, Ag, and Cu. The corrosion detection device according to claim 1.

6. The corrosion detection device according to claim 1, further including a resistor electrically connected to the second-metal electrode.

7. A corrosion state determination system including: the corrosion detection device according to any one of claims 1 to 3, 5, and 6; a power supply for applying a voltage to the corrosion detection device; an ammeter for detecting a current value generated by the voltage applied to the corrosion detection device; and a control device for determining a corrosion state in the corrosion detection device based on the current value measured by the ammeter.

8. The corrosion state determination system according to claim 7, wherein the control device determines a corrosion state of the plurality of wirings of the first metal by comparing a reference current value calculated using a combined resistance value of the plurality of wirings of the first metal and a voltage value of the power supply with the current value.

9. a storage medium for storing the corrosion state determined by the control device A communication device that transmits the corrosion state determined by the control device to the outside, The corrosion state determination system according to claim 7, further comprising a display device that displays the determination result of the control device.

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