Electrical equipment and methods for manufacturing electrical equipment

Abstract

The present invention provides electrical equipment and a method for manufacturing electrical equipment that suppresses the deterioration of insulation performance in insulating materials. [Solution] The electrical device comprises an insulator and a pair of electrodes. The insulator has a mixed region formed on at least a part of its upper surface, in which a plurality of first regions and a second region that is larger than or equal to the plurality of first regions and has properties that make it less likely for conductive foreign matter to adhere to it than the plurality of first regions are mixed. The pair of electrodes are fixed to the upper surface and are arranged in a first direction, facing each other across the mixed region.

Description

Technical Field

[0001] Embodiments of the present invention relate to an electric device and a method for manufacturing an electric device.

Background Art

[0002] In electric devices used for power generation, power transmission, power distribution, etc. in a power system, there are parts that become high voltage. In order to insulate this high voltage part from a grounding part or the like, an insulator is provided between them.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In an electric device that is operated for a long period of time, when the regions where contaminants accumulate on the insulator are continuous, a current path that bridges between a pair of electrodes is formed, leading to flashover and potentially reducing the insulation performance of the insulator. Therefore, it is preferable that the electric device has a configuration in which the continuity of the regions where contaminants accumulate on the insulator is suppressed.

[0005] The problem to be solved by the present invention is to provide an electric device and a method for manufacturing an electric device that suppress a decrease in insulation performance in an insulator.

Means for Solving the Problems

[0006] To achieve the above objective, an electrical device according to an embodiment of the present invention comprises an insulator and a pair of electrodes. The insulator has a mixed region formed on at least a part of its upper surface, in which a plurality of first regions and a second region that is larger than or equal to the plurality of first regions and has properties that make it less likely for conductive foreign matter to adhere to it than the plurality of first regions are mixed. The pair of electrodes are fixed to the upper surface and are arranged in a first direction, facing each other across the mixed region. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a perspective view showing a part of the configuration of the electrical equipment according to the first embodiment. [Figure 2] Figure 2 is a plan view showing a part of the configuration of the electrical equipment according to the first embodiment. [Figure 3] Figure 3 is a plan view showing a part of the configuration of the electrical equipment according to the first embodiment, and shows a state in which conductive foreign matter is uniformly attached to the upper surface of the insulator. [Figure 4] Figure 4 is a plan view showing a part of the configuration of the electrical equipment according to the first embodiment, and is a diagram showing the current density distribution in Figure 3. [Figure 5] Figure 5 is a plan view showing a part of the configuration of the electrical equipment according to the first embodiment, and is a diagram showing the potential distribution in Figure 3. [Figure 6] Figure 6 is a plan view showing a part of the configuration of an electrical device according to the first embodiment, and illustrates a state in which conductive foreign matter is unevenly attached to the upper surface of the insulator. [Figure 7] Figure 7 is a plan view showing a part of the configuration of the electrical equipment according to the first embodiment, and is a diagram showing the current density distribution in Figure 6. [Figure 8] Figure 8 is a plan view showing a part of the configuration of the electrical equipment according to the first embodiment, and is a diagram showing the potential distribution in Figure 6. [Figure 9] Figure 9 is a plan view showing a part of the configuration of an electrical device according to the first embodiment, and shows a state in which regions with different properties are mixed and arranged on the upper surface of the insulator. [Figure 10]Figure 10 is a side view showing a part of the configuration of an electrical device according to the first embodiment, and shows a state in which hydrophilic and hydrophobic regions are mixed and arranged on the upper surface of the insulator. [Figure 11] Figure 11 is a side view showing a part of the configuration of an electrical device according to the first embodiment, and shows a state in which dry conductive foreign matter has accumulated on the upper surface of an insulator in which hydrophilic and hydrophobic regions are arranged together. [Figure 12] Figure 12 is a side view showing a part of the configuration of an electrical device according to the first embodiment, and illustrates a state in which dry conductive foreign matter has accumulated and absorbed moisture on the upper surface of an insulator in which hydrophilic and hydrophobic regions are arranged together. [Figure 13] Figure 13 is a flowchart illustrating an example of the process by which an insulator is insulated by a mixed area of ​​electrical equipment according to the first embodiment. [Figure 14] Figure 14 is a perspective view showing a part of another configuration of the electrical equipment according to the first embodiment. [Figure 15] Figure 15 is a plan view showing a part of the configuration of an electrical device according to the first embodiment, and shows a state in which regions with different properties are mixed on the upper surface of the insulator and are spaced apart from each other. [Figure 16] Figure 16 is a plan view showing a part of the configuration of an electrical device according to the first embodiment, and shows a state in which different regions of different shapes with different properties are mixed on the upper surface of the insulator and are spaced apart from each other. [Figure 17] Figure 17 is a side view showing another part of the electrical equipment according to the first embodiment, and shows an insulator with a recess provided on its upper surface. [Figure 18] Figure 18 is a side view showing another part of the electrical equipment according to the first embodiment, and shows an insulator with a recess of a different shape provided on its upper surface. [Figure 19] Figure 19 is a plan view showing a part of the configuration of an electrical device according to the second embodiment, and shows a state in which regions with different properties are mixed and arranged on the upper surface of the insulator. [Figure 20]FIG. 20 is a side view showing a part of the configuration of the electrical device according to the second embodiment, and is a diagram showing a state in which regions with high water absorbency and regions with low water absorbency are arranged in a mixed manner on the upper surface of the insulator. [Figure 21] FIG. 21 is a side view showing a part of the configuration of the electrical device according to the second embodiment, and is a diagram showing a state in which dried conductive foreign matter has accumulated on the upper surface of the insulator in which regions with high water absorbency and regions with low water absorbency are arranged in a mixed manner. [Figure 22] FIG. 22 is a side view showing a part of the configuration of the electrical device according to the second embodiment, and is a diagram showing a state in which dried conductive foreign matter has accumulated and absorbed moisture on the upper surface of the insulator in which regions with high water absorbency and regions with low water absorbency are arranged in a mixed manner.

MODE FOR CARRYING OUT THE INVENTION

[0008] [First Embodiment] Hereinafter, embodiments of the electrical device 1 in the present invention will be described in detail with reference to the accompanying drawings. The configurations of the embodiments described below, as well as the actions and results (effects) brought about by such configurations, are merely examples and are not limited to the following description. In this specification, ordinal numbers are used only for distinguishing parts and members and do not indicate order or priority.

[0009] First, referring to FIGS. 1 and 2, the configuration of the electrical device 1 according to the embodiment of the present invention will be described. FIG. 1 is a perspective view showing a part of the configuration of the electrical device 1 according to the first embodiment. FIG. 2 is a plan view showing a part of the configuration of the electrical device 1 according to the first embodiment.

[0010] The electrical device 1 includes an insulating system in which an insulator 10 having a creepage surface is provided between a pair of electrodes. A DC voltage is applied to the pair of electrodes. The pair of electrodes are provided isolated from each other for electrical insulation. Note that the structure of the electrical device 1 of the first embodiment is not limited to the example shown in FIG. 1.

[0011] In the following description, an X-axis, Y-axis, and Z-axis orthogonal coordinate system is defined. The direction in which a pair of electrodes are separated is defined as the X-axis direction, and the direction in which each electrode of the pair extends is defined as the Y-axis direction. Furthermore, the direction perpendicular to the X-axis and Y-axis directions is defined as the Z-axis direction. The X-axis direction may also be referred to as the width direction. The Y-axis direction may also be referred to as the depth direction. The Z-axis direction may also be referred to as the height direction. Note that the X-axis, Y-axis, and Z-axis orthogonal coordinate system is a coordinate system used for convenience, and embodiments of the present invention can also be applied to electrical equipment 1 to which this coordinate system is not applicable. The X-axis direction is an example of a first direction. The Z-direction is an example of a second direction.

[0012] As shown in Figures 1 and 2, the electrical device 1 comprises an insulator 10, a high-voltage electrode 11a, and a ground electrode 11b. The insulator 10 is a part of the electrical device 1 that has a creepage surface with insulating properties. The insulator 10 is provided in a part of the electrical device 1 where high voltage is generated. The insulator 10 is formed in a substantially rectangular parallelepiped shape and extends in the X-axis direction. The high-voltage electrode 11a and the ground electrode 11b are fixed to the upper surface 101 of the insulator 10 and are spaced apart from each other in the X-axis direction. The high-voltage electrode 11a and the ground electrode 11b are an example of a pair of electrodes. In the following description, the high-voltage electrode 11a and the ground electrode 11b may be collectively referred to as a pair of electrodes.

[0013] A conductive foreign substance 13 is attached to the upper surface 101. The conductive foreign substance 13 is, for example, contaminants originating from the installation environment of the electrical equipment 1.

[0014] In this embodiment, the electrical equipment 1 is installed in an indoor environment such as an electrical room. Generally, in the case of electrical equipment installed in an indoor environment, contaminants originating from the installation environment gradually accumulate on the insulator over a long period of time. For this reason, it is assumed that the contaminants accumulate almost uniformly on the insulator.

[0015] Furthermore, generally, when power grids and other power equipment are installed in coastal areas, conductive foreign matter originating from seawater may adhere to the surface of the insulators within the equipment. In this case, the conductive foreign matter originating from seawater is a conductive foreign matter containing sodium chloride, which is a deliquescent substance. In high-humidity environments, this conductive foreign matter containing sodium chloride absorbs moisture through deliquescence and becomes saturated with water. In electrical equipment that is operated for a long period of time, if areas where conductive foreign matter originating from seawater adheres to and accumulates on the surface of the insulator are continuous, a water film forms on the deliquescent conductive foreign matter, and the surface resistance of that area decreases significantly.

[0016] When such low surface resistance regions increase, a current path bridging between the high-voltage electrode and the ground electrode may form, increasing the current flowing through that region. In areas where the current value increases, Joule heating causes the water film to dry, leading to the formation of high-electric-field areas and resulting in local discharge. This causes low-resistance carbides to adhere to the insulator, forming conductive paths on the surface and causing tracking. If tracking occurs repeatedly, the area where carbides adhere expands, shortening the insulation distance between the high-voltage electrode and the ground electrode, which can lead to flashover and potentially degrade the insulation performance of the insulator.

[0017] Therefore, in order to suppress the deterioration of the insulating performance of the insulator 10 in the electrical equipment 1, it is preferable to prevent the formation of a bridging current path between the high-voltage electrode 11a and the ground electrode 11b by ensuring that the area on the upper surface 101 where conductive foreign matter 13 is attached is not continuous.

[0018] A mixed region 1011 is formed on the upper surface 101. The mixed region 1011 is formed on at least a part of the upper surface 101. More specifically, the mixed region 1011 is formed over the entire upper surface 101, excluding a pair of electrodes (high-voltage electrode 11a and ground electrode 11b). The pair of electrodes are positioned opposite each other in the X-axis direction, with the mixed region 1011 in between. The mixed region 1011 contains a plurality of first regions 1011a and a second region 1011b that is larger than or equal to the plurality of first regions 1011a and has properties that make it less likely for conductive foreign matter 13 to adhere to it than the plurality of first regions 1011a. Note that the first region 1011a and the second region 1011b are omitted in Figures 1 and 2. Details of the first region 1011a and the second region 1011b will be described later.

[0019] [Current distribution between a pair of electrodes] Next, the distribution of current flowing between a pair of electrodes when conductive foreign matter 13 is uniformly attached to the upper surface 101 will be explained using Figures 3 to 5. Figure 3 is a plan view showing a part of the configuration of the electrical device 1 according to the first embodiment, and is a diagram showing the state in which conductive foreign matter 13 is uniformly attached to the upper surface 101 of the insulator 10.

[0020] In Figure 3, the black areas represent conductive foreign matter 13 that has absorbed moisture and contains water, and the white areas represent the substrate (top surface 101) of the insulator 10. Although Figure 3 shows only a portion of the top surface 101 of the insulator 10, the distribution of conductive foreign matter 13 in areas not shown in Figure 3 is approximately the same as that in Figure 3. In the following explanation, unless otherwise specified, the conductive foreign matter 13 is assumed to have absorbed moisture and contains water.

[0021] As shown in Figure 3, the conductive foreign matter 13 is distributed almost uniformly across the entire upper surface 101 (mixed region 1011) of the insulator 10. In other words, in the region of the upper surface 101 shown in Figure 3, the multiple conductive foreign matter 13 adhering to the upper surface 101 are spaced apart from each other.

[0022] Figure 4 is a plan view showing a part of the configuration of the electrical equipment 1 according to the first embodiment, and is a diagram showing the current density distribution in Figure 3. As shown in Figure 4, the current density is locally high in areas where multiple conductive foreign objects 13 are in close proximity to each other, but this area is sufficiently small relative to the upper surface 101. On the other hand, in areas where the other multiple conductive foreign objects 13 are not in close proximity to each other, the current density distribution is substantially homogeneous.

[0023] Figure 5 is a plan view showing a part of the configuration of the electrical equipment 1 according to the first embodiment, and is a diagram showing the potential distribution in Figure 3. As shown in Figure 5, the potential distribution on the upper surface 101 shows that the potential gradually decreases in the X-axis direction as you approach the ground electrode 11b from the high-voltage electrode 11a. In the Y-axis direction, the potential distribution is substantially homogeneous. That is, the potential distribution between the pair of electrodes of the insulator 10 is substantially homogeneous.

[0024] Next, the distribution of current flowing between a pair of electrodes when conductive foreign matter 13 is unevenly attached to the upper surface 101 will be explained with reference to Figures 6 to 8. Figure 6 is a plan view showing a part of the configuration of the electrical equipment 1 according to the first embodiment, and is a diagram showing the state in which conductive foreign matter 13 is unevenly attached to the upper surface 101 of the insulator 10.

[0025] In Figure 6, the black areas represent conductive foreign matter 13 that has absorbed moisture and contains water, while the white areas represent the substrate (top surface 101) of the insulator 10. Although Figure 6 shows only a portion of the top surface 101 of the insulator 10, the distribution (variation) of conductive foreign matter 13 in areas not shown in Figure 6 is approximately the same as that shown in Figure 6.

[0026] As shown in Figure 6, the conductive foreign matter 13 is distributed almost non-uniformly across the entire upper surface 101 of the insulator 10. Furthermore, there are multiple connecting points of the conductive foreign matter 13 on the upper surface 101. Here, a connecting point of the conductive foreign matter 13 refers to a state where multiple conductive foreign matter 13 attached to the upper surface 101 in close proximity to each other are in contact and continuous. The same applies to the following explanation.

[0027] Figure 7 is a plan view showing a part of the configuration of the electrical equipment 1 according to the first embodiment, and is a diagram showing the current density distribution in Figure 6. As shown in Figure 7, a long connecting portion of conductive foreign matter 13 exists between the high-voltage electrode 11a and the ground electrode 11b. At this location, a current path is formed bridging the high-voltage electrode 11a and the ground electrode 11b, and the current density is relatively high at the break C1 in the connection of the conductive foreign matter 13 on the current path.

[0028] Figure 8 is a plan view showing a part of the configuration of the electrical equipment 1 according to the first embodiment, and is a diagram showing the potential distribution in Figure 6. As shown in Figure 8, in the long connecting portion of the conductive foreign material 13 present between the high-voltage electrode 11a and the ground electrode 11b, the potential gradient changes abruptly at the break in the connection C2 where the long connecting portion on the high-voltage electrode 11a side and the long connecting portion on the ground electrode 11b side are close together. At this location C2, the electric field strength increases significantly due to the abrupt change in the potential gradient.

[0029] Therefore, it is thought that if conductive foreign matter 13 containing moisture adheres to the entire upper surface 101 of the insulator 10 in a substantially non-uniform manner, the formation of current paths, tracking due to the generation of high-electric-field areas, and the adhesion of corrosion products are promoted, thereby reducing the insulating performance of the insulator 10. For this reason, by making the adhesion of conductive foreign matter 13 to the upper surface 101 of the insulator 10 substantially uniform, the reduction in the insulating performance of the insulator 10 can be suppressed.

[0030] Next, the details of the mixed region 1011 formed on the upper surface 101 of the insulator 10 will be described with reference to Figure 9. Figure 9 is a plan view showing a part of the configuration of the electrical equipment 1 according to the first embodiment, and shows a state in which regions with different properties are mixed and arranged on the upper surface 101 of the insulator 10.

[0031] In this embodiment, the regions with different properties refer to the multiple first regions 1011a and second regions 1011b formed within the mixed region 1011. Furthermore, in the example shown in Figure 9, the second region 1011b is divided into multiple regions by multiple first regions 1011a.

[0032] In this embodiment, the multiple first regions 1011a are hydrophilic regions and are more prone to the adhesion of moisture-containing conductive foreign matter 13 than the second region 1011b. The second region 1011b is a hydrophobic region and is less prone to the adhesion of moisture-containing conductive foreign matter 13 than the multiple first regions 1011a. Therefore, when moisture-containing conductive foreign matter 13 adheres to the mixed region 1011 formed on the upper surface 101, the conductive foreign matter 13 adheres unevenly to the first region 1011a.

[0033] The multiple first regions 1011a and second regions 1011b are, for example, regions that have undergone a roughening treatment. Furthermore, the hydrophilicity in the multiple first regions 1011a and the hydrophobicity in the second regions 1011b are brought about by the roughening treatment. The roughening treatment is a process that applies minute irregularities to the upper surface 101 of the insulator 10.

[0034] Generally, when the surface of an insulator is roughened, its hydrophilic properties become stronger if the contact angle of the insulator with the liquid does not exceed 90 degrees, and its hydrophobic properties become stronger if the contact angle exceeds 90 degrees.

[0035] Therefore, by applying a roughening treatment to the first region 1011a and the second region 1011b, the hydrophilic or hydrophobic properties in the mixed region 1011 can be controlled.

[0036] Another method for providing hydrophilic or hydrophobic properties to the first region 1011a and the second region 1011b is to arrange multiple materials with different surface free energies on the upper surface 101 of the insulator 10. In this case, the multiple first regions 1011a are regions with higher surface free energies than the multiple second regions 1011b, and the hydrophilicity in the multiple first regions 1011a and the hydrophobicity in the second regions 1011b are brought about by the difference in the surface free energies of the insulator 10.

[0037] Generally, liquids tend to adhere to the surface of solids made of materials with high surface free energy, while liquids do not adhere to the surface of solids made of materials with low surface free energy.

[0038] Therefore, for example, on the upper surface 101 of the insulator 10, by placing a material with high surface free energy in the location where the first region 1011a is located, and a material with low surface free energy in the location where the second region 1011b is located, the hydrophilic or hydrophobic properties in the mixed region 1011 can be controlled.

[0039] The multiple first regions 1011a are positioned so as not to be adjacent to each other. More specifically, each of the multiple first regions 1011a and the multiple second regions 1011b are formed in an alternating grid pattern. Here, each of the multiple first regions 1011a is adjacent to a second region 1011b, but not adjacent to any other first region 1011a.

[0040] In other words, the first region 1011a and the second region 1011b are arranged alternately. Also in other words, multiple first regions 1011a are discretely arranged with second regions 1011b interposed between them. Also in other words, on the upper surface 101, only the ends of multiple first regions 1011a are adjacent to each other, and the rest are spaced apart. Also in other words, on the upper surface 101, multiple first regions 1011a are arranged so that the islands of each region are not adjacent to each other. Also in other words, on the upper surface 101, multiple first regions 1011a are arranged so that multiple islands of regions that are not adjacent to each other are formed.

[0041] Here, the conductive foreign matter 13 adheres unevenly to each of the multiple first regions 1011a that are not adjacent to each other in the mixed region 1011. As a result, the continuity of regions on the upper surface 101 to which the conductive foreign matter 13 adheres is suppressed.

[0042] As shown in Figure 9, in directions other than the X-axis and Y-axis directions, there are small areas (for example, area S) on the mixed region 1011 where the hydrophilic first region 1011a is continuous. In these areas, there is a possibility that connecting parts of the conductive foreign matter 13 exist and current paths are formed.

[0043] Next, the process by which conductive foreign matter 13 accumulates and moves in the mixed region 1011 formed on the upper surface 101 of the insulator 10 will be described with reference to Figures 10 to 12. Figure 10 is a side view showing a part of the configuration of the electrical equipment 1 according to the first embodiment, and shows a state in which hydrophilic and hydrophobic regions are mixed and arranged on the upper surface 101 of the insulator 10. Figure 10 also shows a view of a part of the configuration of the electrical equipment 1 shown in Figure 9 from the Y-axis direction. Figure 11 is a side view showing a part of the configuration of the electrical equipment 1 according to the first embodiment, and shows a state in which dried conductive foreign matter 13a has accumulated on the upper surface 101 of the insulator 10 in which hydrophilic and hydrophobic regions are mixed and arranged. Figure 12 is a side view showing a part of the configuration of the electrical equipment 1 according to the first embodiment, and shows a state in which dried conductive foreign matter 13a has accumulated and absorbed moisture on the upper surface 101 of the insulator 10 in which hydrophilic and hydrophobic regions are mixed and arranged.

[0044] In the state shown in Figure 10, as also shown in Figure 9, multiple hydrophilic regions and multiple hydrophobic regions are alternately formed in the X-axis direction. Furthermore, each hydrophilic region and each hydrophobic region are approximately the same size.

[0045] As shown in Figure 10, when the dried conductive foreign matter 13a accumulates on the upper surface 101 of the insulator 10, it results in the state shown in Figure 11. As described above, the dried conductive foreign matter 13a accumulates almost uniformly on the upper surface 101 due to accumulation over a long period of time.

[0046] Then, in Figure 11, when the conductive foreign matter 13a, which has dried due to an increase in humidity, absorbs moisture, the moisture-absorbing conductive foreign matter 13b moves to the first region 1011a, which has hydrophilic properties, resulting in the state shown in Figure 12.

[0047] In this case, since each of the multiple hydrophilic regions (the first region 1011a) is spaced apart from each other in the X-axis direction, the moisture-absorbing conductive foreign matter 13b on the first region 1011a is similarly spaced apart from each other. That is, on the upper surface 101, the continuity of regions to which moisture-absorbing conductive foreign matter 13b is attached is suppressed, and the formation of a bridging current path between the high-voltage electrode 11a and the ground electrode 11b is suppressed.

[0048] Next, a process for suppressing the deterioration of the insulating performance in the insulator 10 will be described with reference to Figure 13. Figure 13 is a flowchart showing an example of the process by which the insulator 10 is insulated by the mixed region 1011 of the electrical equipment 1 according to the first embodiment. The flowchart shown in Figure 13 shows the process from when a DC voltage is applied between a pair of electrodes to when the insulator 10 is insulated, in an electrical equipment 1 having an insulator 10 on which conductive foreign matter 13 is attached to the upper surface 101 on which the mixed region 1011 is formed.

[0049] In step S101 in Figure 13, first, a DC voltage is applied to the high-voltage electrode 11a. Then, in step S102, when the environment in which the electrical equipment 1 is installed becomes a humid environment, the conductive foreign matter 13 absorbs moisture and spreads wet on the upper surface 101 of the insulator 10, forming a water film.

[0050] Then, in step S103, the surface resistance of the area where the water film is formed decreases significantly, making it easier for bridging to occur between the high-voltage electrode 11a and the ground electrode 11b. Here, since multiple hydrophilic regions and multiple hydrophobic regions are alternately formed on the upper surface 101 of the insulator 10, the formation of a current path by bridging between the pair of electrodes is suppressed (step S104).

[0051] Therefore, in step S105, drying of the water film due to Joule heating is suppressed on the upper surface 101 of the insulator 10, and local discharge associated with the formation of high-electric-field areas does not occur. Furthermore, in step S106, tracking occurs where low-resistance carbides adhere to the upper surface 101 of the insulator 10, forming conductive paths on the surface and leading to flashover is suppressed. Through this process, the electrical equipment 1 is insulated on the insulator 10.

[0052] In the above embodiment, the electrical device 1 comprises an insulator 10 and a pair of electrodes (a high-voltage electrode 11a and a ground electrode 11b). The insulator 10 has a mixed region 1011 formed on at least a part of its upper surface 101, which consists of a plurality of first regions 1011a and a second region 1011b that is larger than or equal to the plurality of first regions 1011a and has properties that make it less likely for conductive foreign matter 13 to adhere to it than the plurality of first regions 1011a. The pair of electrodes are fixed to the upper surface 101 and are arranged in positions facing each other in the X-axis direction, with the mixed region 1011 in between.

[0053] In the above configuration, a mixed region 1011 is formed on at least a part of the upper surface 101 of the insulator 10 between a pair of electrodes (high-voltage electrode 11a and ground electrode 11b), where a plurality of first regions 1011a and a plurality of second regions 1011b that are larger than or equal in size to the plurality of first regions 1011a and have properties that make it less likely for conductive foreign matter 13 to adhere to them. As a result, the conductive foreign matter 13 adheres unevenly to the first regions 1011a, thus suppressing the formation of continuous regions on the upper surface 101 where conductive foreign matter 13 adheres.

[0054] As a result, the electrical device 1 is prevented from forming a current path that bridges between the pair of electrodes, which can lead to a flashover, and consequently, a decrease in the insulating performance of the insulator 10 can be suppressed.

[0055] Furthermore, in the above-described embodiment, the multiple first regions 1011a are positioned so as not to be adjacent to one another.

[0056] In the above configuration, the conductive foreign matter 13 adheres more easily to multiple first regions 1011a than to the second region 1011b, and these regions are positioned so that they are not adjacent to each other. As a result, the conductive foreign matter 13 adheres preferentially to the first regions 1011a that are not adjacent to each other, thus suppressing the formation of continuous areas on the upper surface 101 where the conductive foreign matter 13 is attached.

[0057] As a result, the electrical device 1 is prevented from forming a current path that bridges between the pair of electrodes (high-voltage electrode 11a and ground electrode 11b), which can lead to a flashover, and consequently, a decrease in the insulating performance of the insulator 10 can be suppressed.

[0058] Furthermore, in the above-described embodiment, the plurality of first regions 1011a are hydrophilic regions, and the plurality of second regions 1011b are hydrophobic regions.

[0059] In the above configuration, a hydrophilic first region 1011a to which moisture-containing conductive foreign matter 13b easily adheres, and a hydrophobic second region 1011b which is larger than the first region 1011a and to which moisture-containing conductive foreign matter 13b is less likely to adhere, are mixed in the mixed region 1011. As a result, when moisture-containing conductive foreign matter 13b adheres to the upper surface 101, the conductive foreign matter 13 tends to adhere to the hydrophilic first region 1011a, thus suppressing the continuity of regions on the upper surface 101 to which moisture-containing conductive foreign matter 13b adheres.

[0060] As a result, the electrical device 1 is prevented from forming a current path that bridges between the pair of electrodes (high-voltage electrode 11a and ground electrode 11b), which can lead to a flashover, and consequently, a decrease in the insulating performance of the insulator 10 can be suppressed.

[0061] Furthermore, in the above-described embodiment, the plurality of first regions 1011a and the plurality of second regions 1011b are roughened regions, and the hydrophilicity in the plurality of first regions 1011a and the hydrophobicity in the plurality of second regions 1011b are brought about by the roughening treatment.

[0062] In the above configuration, a first hydrophilic region 1011a that has been roughened and a second hydrophobic region 1011b that has been roughened more than the first region 1011a are mixed in the mixed region 1011. As a result, the conductive foreign matter 13 adheres unevenly to the hydrophilic first region 1011a, thus suppressing the formation of continuous areas on the upper surface 101 where conductive foreign matter 13b containing moisture is attached.

[0063] As a result, the electrical device 1 is prevented from forming a current path that bridges between the pair of electrodes (high-voltage electrode 11a and ground electrode 11b), which can lead to a flashover, and consequently, a decrease in the insulating performance of the insulator 10 can be suppressed.

[0064] Furthermore, in the above-described embodiment, the plurality of first regions 1011a are regions in which the surface free energy is higher than that of the plurality of second regions 1011b, and the hydrophilicity in the plurality of first regions 1011a and the hydrophobicity in the plurality of second regions 1011b are brought about by the difference in the surface free energy of the insulator 10.

[0065] In the above configuration, the mixed region 1011 contains a first hydrophilic region 1011a with a surface free energy higher than that of the second region 1011b, and a second hydrophobic region 1011b with a surface free energy lower than that of multiple first regions 1011a. As a result, the conductive foreign matter 13 adheres unevenly to the hydrophilic first region 1011a. Therefore, the continuous formation of regions on the upper surface 101 where conductive foreign matter 13b containing moisture adheres is suppressed.

[0066] As a result, the electrical device 1 is prevented from forming a current path that bridges between the pair of electrodes (high-voltage electrode 11a and ground electrode 11b), which can lead to a flashover, and consequently, a decrease in the insulating performance of the insulator 10 can be suppressed.

[0067] [Example 1] Next, a modification 1 of the first embodiment will be described with reference to Figure 14. Components similar to those in the electrical equipment 1 according to the first embodiment are denoted by the same reference numerals and their descriptions are omitted; different components will be described below.

[0068] Figure 14 is a perspective view showing a part of another configuration of the electrical device 1 according to the first embodiment. Figure 14 shows the electrical device 1 in which the size of the mixed region 1011s formed on the upper surface 101 is different from that in Figure 1.

[0069] As shown in Figure 14, the mixed region 1011s is smaller than the mixed region 1011 (see Figure 1) and is formed near the center of the electrical equipment 1 in the X-axis direction. The mixed region 1011s extends in the Y-axis direction and is spaced apart from the pair of electrodes (high-voltage electrode 11a and ground electrode 11b). The pair of electrodes are positioned opposite each other in the X-axis direction, with the mixed region 1011 in between, as in Figure 1.

[0070] The mixed region 1011s includes a first region 1011a having hydrophilic properties and a second region 1011b having hydrophobic properties. Therefore, when a conductive foreign substance 13b containing moisture adheres to the upper surface 101, the conductive foreign substance 13 adheres unevenly to the mixed region 1011s, which includes the first region 1011a.

[0071] In this case, when conductive foreign matter 13 is attached to the mixed region 1011s, the conductive foreign matter 13 is spaced apart from the pair of electrodes, thus suppressing the formation of a bridging current path between the high-voltage electrode 11a and the ground electrode 11b. In other words, in the electrical equipment 1 of the modified example 1, similar to the first embodiment, the formation of a bridging current path between the high-voltage electrode 11a and the ground electrode 11b is suppressed.

[0072] [Differentiation 2] Next, a modification 2 of the first embodiment will be described with reference to Figure 15. Figure 15 is a plan view showing a part of the configuration of the electrical equipment 1 according to the first embodiment, and shows a state in which regions with different properties are mixed on the upper surface 101 of the insulator 10 and are spaced apart from each other.

[0073] In the electrical device 1 in modified example 2, the multiple first regions 1011a are spaced apart from each other on the XY plane, unlike in Figure 9. The multiple first regions 1011a are formed in a roughly rectangular shape and are spaced apart from each other at roughly equal intervals. Here, each of the multiple first regions 1011a is adjacent to a second region 1011b, but is spaced apart from and not adjacent to any other first region 1011a.

[0074] In other words, each of the multiple first regions 1011a is formed discontinuously with respect to the upper surface 101. In other words, the multiple first regions 1011a are arranged such that the islands of each region are spaced apart from each other on the upper surface 101. In other words, the multiple first regions 1011a are arranged such that multiple islands of regions that are spaced apart from each other are formed on the upper surface 101.

[0075] Here, the conductive foreign matter 13 adheres unevenly to each of the multiple first regions 1011a that are spaced apart and not adjacent to one another. As a result, the continuity of regions on the upper surface 101 to which the conductive foreign matter 13 adheres is suppressed.

[0076] In the embodiments described above, the multiple first regions 1011a are spaced apart from each other.

[0077] In the above configuration, the first regions 1011a, which have properties that make it easier for conductive foreign matter 13 to adhere to them than the second region 1011b, are spaced apart from each other. As a result, the conductive foreign matter 13 adheres unevenly to the spaced-apart first regions 1011a, thus suppressing the continuity of regions on the upper surface 101 to which conductive foreign matter 13 adheres.

[0078] As a result, the electrical device 1 is prevented from forming a current path that bridges between the pair of electrodes (high-voltage electrode 11a and ground electrode 11b), which can lead to a flashover, and consequently, a decrease in the insulating performance of the insulator 10 can be suppressed.

[0079] [Difference 3] Next, a third modification of the first embodiment will be described using Figure 16. Figure 16 is a plan view showing a part of the configuration of the electrical equipment 1 according to the first embodiment, and shows a state in which different regions of different shapes with different properties are mixed on the upper surface 101 of the insulator 10 and are spaced apart from each other.

[0080] In the electrical device 1 in modified example 3, the multiple first regions 1011a are spaced apart from each other on the XY plane, similar to Figure 15 (modified example 2). Also, unlike Figure 15 (modified example 2), the multiple first regions 1011a are formed in a substantially circular shape.

[0081] In Modification 3, as in Modification 2, the conductive foreign matter 13 adheres unevenly to each of the multiple first regions 1011a that are spaced apart and not adjacent to each other. As a result, the continuity of regions on the upper surface 101 to which the conductive foreign matter 13 adheres is suppressed.

[0082] [Differentiation Example 4] Next, a fourth modification of the first embodiment will be described using Figure 17. Figure 17 is a side view showing a part of another configuration of the electrical equipment 1 according to the first embodiment, and shows an insulator 10 with a recess 102a provided on its upper surface 101.

[0083] In the electrical device 1 of modified example 4, the upper surface 101 of the insulator 10 has hydrophobic properties with a contact angle exceeding 90 degrees. Furthermore, recesses 102a that are concave in the -Z direction are provided in the portion of the insulator 10 where the multiple first regions 1011a are located. The hydrophilicity of the multiple first regions 1011a is provided by the recesses 102a.

[0084] The recesses 102a are arranged on the upper surface 101 of the insulator 10 at approximately equal intervals from each other in the X-axis direction. Although not shown in the figure, the recesses 102a are also arranged at approximately equal intervals from each other in the Y-axis direction of the upper surface 101. The recesses 102a are formed in a roughly triangular shape when viewed from the Y-axis direction. Furthermore, the recesses 102a are formed in a roughly circular conical shape in plan view, for example.

[0085] Generally, when a recess is provided on the surface of a solid having hydrophobic properties, liquids adhering to the solid surface are easily trapped in the recess by gravity. For this reason, in the electrical device 1 in Modification 4, similar to the electrical device 1 in the first embodiment, the plurality of first regions 1011a have hydrophilic properties.

[0086] In the modified example 4, as in the first embodiment, the conductive foreign matter 13 adheres unevenly to each of the multiple first regions 1011a that are spaced apart and not adjacent to one another. As a result, the continuity of regions on the upper surface 101 to which the conductive foreign matter 13 adheres is suppressed.

[0087] In the above embodiment, the portion of the insulator 10 where the plurality of first regions 1011a are located is provided with a recess 102 that is concave in the -Z direction, which is the direction opposite to the direction in which the upper surface 101 faces, and the hydrophilicity in the plurality of first regions 1011a is provided by the recess 102.

[0088] In the above configuration, the hydrophilic first region 1011a where the recess 102 is provided and the hydrophobic second region 1011b, which is larger than or equal to the first region 1011a, are mixed in the mixed region 1011, causing the conductive foreign matter 13 to adhere predominantly to the hydrophilic first region 1011a. As a result, the continuous formation of areas on the upper surface 101 where the conductive foreign matter 13b containing moisture is attached is suppressed.

[0089] As a result, the electrical device 1 is prevented from forming a current path that bridges between the pair of electrodes (high-voltage electrode 11a and ground electrode 11b), which can lead to a flashover, and consequently, a decrease in the insulating performance of the insulator 10 can be suppressed.

[0090] [Difference 5] Next, a fifth modification of the first embodiment will be described using Figure 18. Figure 18 is a side view showing a part of another configuration of the electrical equipment 1 according to the first embodiment, and shows an insulator 10 with a recess 102b of a different shape provided on its upper surface 101.

[0091] In the electrical device 1 in modified example 5, the upper surface 101 of the insulator 10 has hydrophobic properties with a contact angle exceeding 90 degrees. Furthermore, the recess 102b is formed in a substantially semi-elliptical shape when viewed from the Y-axis direction. Also, the recess 102b is formed in a substantially circular shape when viewed from above.

[0092] In Modification 5, as in Figure 17 (Modification 4), the liquid adhering to the upper surface 101 of the insulator 10 is trapped in the recess 102b by gravity. Therefore, in the electrical device 1 in Modification 5, as in the electrical device 1 in Modification 4, the multiple first regions 1011a have hydrophilic properties.

[0093] In Modification 5, as in Modification 4, the conductive foreign matter 13 adheres unevenly to each of the multiple first regions 1011a that are spaced apart and not adjacent to each other. As a result, the continuity of regions on the upper surface 101 to which the conductive foreign matter 13 adheres is suppressed.

[0094] The shape of the recesses 102a and 102b in plan view is not limited to those described above; for example, they may be formed in a roughly square or roughly triangular shape in plan view. Even when the recesses 102a and 102b formed in the portion where the first region 1011a is located are formed in a roughly square or roughly triangular shape in plan view, their concave shape in the -Z direction allows them to capture conductive foreign matter 13b containing moisture adhering to the upper surface 101 of the insulator 10, thereby giving the first region 1011a hydrophilic properties. As a result, the conductive foreign matter 13 adheres unevenly to each of the first regions 1011a. Consequently, the continuity of areas on the upper surface 101 where conductive foreign matter 13 adheres is suppressed.

[0095] [Second Embodiment] Next, the electrical equipment 1A according to the second embodiment will be described with reference to Figures 19 to 22. Figure 19 is a plan view showing a part of the configuration of the electrical equipment 1A according to the second embodiment, and shows a state in which regions with different properties are mixed and arranged on the upper surface 101A of the insulator 10A.

[0096] In the second embodiment, the plurality of first regions 1011a are regions with higher moisture adsorption capacity than the second region 1011b. Therefore, the first region 1011a is more likely to have moisture-containing conductive foreign matter 13b adhere to it than the second region 1011b. Also, the second region 1011b is a region with lower moisture adsorption capacity than the plurality of first regions 1011a. Therefore, the second region 1011b is less likely to have moisture-containing conductive foreign matter 13b adhere to it than the first region 1011a. That is, when moisture-containing conductive foreign matter 13b adheres to the upper surface 101A, the conductive foreign matter 13 adheres unevenly to the first region 1011a.

[0097] Multiple first regions 1011a have hydrophilic functional groups. Furthermore, the water adsorption properties in multiple first regions 1011a are provided by hydrophilic functional groups. Examples of hydrophilic functional groups include hydroxyl groups, amino groups, and carboxyl groups.

[0098] Multiple first regions 1011a can have their moisture adsorption properties enhanced by chemical methods such as plasma treatment or chemical reactions caused by immersion in a chemical solution.

[0099] Furthermore, multiple first regions 1011a may have a water-absorbing material. In this case, the moisture adsorption in the multiple first regions 1011a is provided by the water-absorbing material. More specifically, the moisture adsorption of the first regions 1011a may be enhanced by physical methods, such as placing a water-absorbing material such as silica gel or zeolite on the upper surface 101A.

[0100] Furthermore, porous materials may be placed in the multiple first regions 1011a. In this case, the moisture adsorption properties in the multiple first regions 1011a are brought about by the fine pores of the porous material trapping moisture. The moisture adsorption properties of the multiple first regions 1011a may be enhanced by physical methods, such as placing a porous material such as activated carbon on the upper surface 101A.

[0101] Figure 20 is a side view showing a part of the configuration of electrical equipment 1A according to the second embodiment, showing a state in which areas with high moisture adsorption and areas with low moisture adsorption are mixed together on the upper surface 101A of the insulator 10A. Also, Figure 20 shows a view of a part of the configuration of electrical equipment 1A shown in Figure 19 from the Y-axis direction. Figure 21 is a side view showing a part of the configuration of electrical equipment 1A according to the second embodiment, showing a state in which dried conductive foreign matter 13a has accumulated on the upper surface 101A of the insulator 10A, where areas with high moisture adsorption and areas with low moisture adsorption are mixed together. Figure 22 is a side view showing a part of the configuration of electrical equipment 1A according to the second embodiment, showing a state in which dried conductive foreign matter 13a has accumulated and absorbed moisture on the upper surface 101A of the insulator 10A, where areas with high moisture adsorption and areas with low moisture adsorption are mixed together.

[0102] As shown in Figure 20, in the second embodiment, similar to the first embodiment (Figure 10), multiple regions with high water adsorption (first region 1011a) and multiple regions with low water adsorption (second region 1011b) are alternately formed in the X-axis direction. Furthermore, each of the regions with high water adsorption and each of the regions with low water adsorption are approximately the same size.

[0103] In Figure 20, when the dried conductive foreign matter 13a accumulates on the upper surface 101A of the insulator 10A, the state shown in Figure 21 occurs.

[0104] Then, in Figure 21, when the conductive foreign matter 13a that has dried due to an increase in humidity absorbs moisture, the moisture-absorbing conductive foreign matter 13b moves only the moisture it contains to the first region 1011a, which has high moisture adsorption capacity, resulting in the state shown in Figure 22. In Figure 22, the conductive foreign matter 13b containing moisture is deposited in the first region 1011a, and the conductive foreign matter 13a that does not contain moisture (dry) is deposited in the second region 1011b.

[0105] In this case, since each of the multiple regions with high moisture adsorption (the first region 1011a) is spaced apart from each other in the X-axis direction, the conductive foreign matter 13b containing moisture on the first region 1011a is similarly spaced apart from each other. That is, on the upper surface 101A, the continuity of regions to which the conductive foreign matter 13b containing moisture is attached is suppressed, and the formation of a bridging current path between the high-voltage electrode 11a and the ground electrode 11b is suppressed.

[0106] In addition, the configurations of Modifications 1, 2, and 3 shown in the first embodiment may also be implemented in the second embodiment. That is, the mixed region 1011A may be smaller than the mixed region 1011 (see Figure 1) and may be formed near the center of the electrical equipment 1A in the X-axis direction. Also, the multiple first regions 1011a may be spaced apart from each other on the XY plane, as shown in Figure 15 (Modification 2). Also, the multiple first regions 1011a may be spaced apart from each other on the XY plane and formed in a substantially circular shape, as shown in Figure 16 (Modification 3).

[0107] In all of the above cases, the conductive foreign matter 13 adheres unevenly to each of the regions with high moisture adsorption (the first region 1011a). As a result, the continuity of regions on the upper surface 101A where the conductive foreign matter 13 is attached is suppressed.

[0108] In the embodiments described above, the plurality of first regions 1011a are regions with higher moisture adsorption properties than the second region 1011b.

[0109] In the above configuration, multiple first regions 1011a with higher moisture adsorption properties than the second region 1011b and second regions 1011b with lower moisture adsorption properties than the multiple first regions 1011a are mixed in the mixed region 1011A. As a result, the conductive foreign matter 13 adheres unevenly to the first regions 1011a with relatively high moisture adsorption properties, thus suppressing the formation of continuous areas on the upper surface 101A where conductive foreign matter 13b containing moisture is attached.

[0110] As a result, the formation of a current path bridging between the pair of electrodes (high-voltage electrode 11a and ground electrode 11b) in the electrical device 1A, which leads to a flashover, is suppressed, and consequently, a decrease in the insulation performance of the insulator 10A can be suppressed.

[0111] Furthermore, in the above-described embodiment, the plurality of first regions 1011a have hydrophilic functional groups, and the water adsorption properties in the plurality of first regions 1011a are provided by the hydrophilic functional groups.

[0112] In the above configuration, multiple first regions 1011a having hydrophilic functional groups and higher moisture adsorption than the second region 1011b, and second regions 1011b that are larger than or equal to the multiple first regions 1011a and have lower moisture adsorption than the multiple first regions 1011a, are mixed in the mixed region 1011A. As a result, the conductive foreign matter 13 adheres unevenly to the first regions 1011a with relatively high moisture adsorption, thus suppressing the formation of continuous regions on the upper surface 101A where conductive foreign matter 13b containing moisture is attached.

[0113] As a result, the formation of a current path bridging between the pair of electrodes (high-voltage electrode 11a and ground electrode 11b) in the electrical device 1A, which leads to a flashover, is suppressed, and consequently, a decrease in the insulation performance of the insulator 10A can be suppressed.

[0114] Furthermore, in the above-described embodiment, the plurality of first regions 1011a have a water-absorbing material, and the moisture adsorption in the plurality of first regions 1011a is provided by the water-absorbing material.

[0115] In the above configuration, multiple first regions 1011a having a water-absorbing material and higher moisture adsorption capacity than the second region 1011b, and second regions 1011b that are larger than or equal to the multiple first regions 1011a and have lower moisture adsorption capacity than the multiple first regions 1011a, are mixed in the mixed region 1011. As a result, the conductive foreign matter 13 adheres unevenly to the first regions 1011a with relatively high moisture adsorption capacity, thus suppressing the formation of continuous regions on the upper surface 101 to which the moisture-containing conductive foreign matter 13b adheres.

[0116] As a result, the formation of a current path bridging between the pair of electrodes (high-voltage electrode 11a and ground electrode 11b) in the electrical device 1A, which leads to a flashover, is suppressed, and consequently, a decrease in the insulation performance of the insulator 10A can be suppressed.

[0117] [Manufacturing methods for electrical equipment] Next, an example of a method for manufacturing electrical equipment according to each embodiment will be described. First, the high-voltage electrode 11a and the ground electrode 11b are fixed to the upper surface 101 of the insulator 10 in positions facing each other. Then, at least a part of the upper surface 101 of the insulator 10 is provided with a mixed region in which a plurality of first regions 1011a and second regions 1011b according to each embodiment are mixed, in a position sandwiched between the high-voltage electrode 11a and the ground electrode 11b.

[0118] For example, in the case of electrical equipment 1 according to the first embodiment, a mixed region 1011 in which multiple hydrophilic regions (first region 1011a) and hydrophobic regions (second region 1011b) are mixed is formed on at least a part of the upper surface 101. Also, for example, in the case of electrical equipment 1A according to the second embodiment, a mixed region 1011A in which a first region 1011a having higher moisture adsorption properties than the second region 1011b and a second region 1011b having lower moisture adsorption properties than the first region 1011a are mixed is formed on at least a part of the upper surface 101A by, for example, the physical or chemical method described above. Electrical equipment 1 and 1A are manufactured by the above steps.

[0119] Furthermore, the electrical equipment according to each embodiment can also be manufactured by providing a mixed region according to each embodiment on the upper surface of the insulator, and then fixing the high-voltage electrode 11a and the ground electrode 11b to the upper surface thereon, spaced apart from each other.

[0120] The method for manufacturing the electrical device 1 carried out in the above embodiment involves manufacturing an electrical device 1 comprising an insulator 10 and a pair of electrodes (high-voltage electrode 11a and ground electrode 11b) fixed to the upper surface 101 of the insulator 10 and arranged at positions facing each other in the X-axis direction, and forming a mixed region 1011 on at least a part of the upper surface 101 of the insulator 10 at a position sandwiched between the pair of electrodes on the upper surface 101 of the insulator 10, in which a plurality of first regions 1011a and a second region 1011b that is larger than or equal to the plurality of first regions 1011a and has properties that make it less likely for conductive foreign matter 13 to adhere than the plurality of first regions 1011a are mixed.

[0121] In the manufacturing method of the electrical device 1 described above, the conductive foreign matter 13 adheres unevenly to the first region 1011a. As a result, the electrical device 1 prevents the area on the upper surface 101 from being continuous, which prevents the formation of a current path bridging between the pair of electrodes (high-voltage electrode 11a and ground electrode 11b) and leading to a flashover, and consequently prevents a decrease in the insulating performance of the insulator 10.

[0122] Although several embodiments of the present invention have been described above, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. [Explanation of Symbols]

[0123] 1. 1A electrical equipment 10, 10A insulator 11a High-voltage electrode 11b Ground electrode 13, 13a, 13b Conductive foreign matter 101, 101A top surface 102, 102a, 102b recesses 1011, 1011A, 1011s mixed area 1011a First area 1011b Second area C1, C2: Break in the connection of conductive foreign matter. S area

Claims

1. An insulator having a mixed region formed on at least a part of its upper surface, in which a plurality of first regions and a second region that is larger than or equal to the plurality of first regions and has properties that make it less likely for conductive foreign matter to adhere to it than the plurality of first regions are mixed, A pair of electrodes fixed to the upper surface and arranged in a first direction at positions facing each other across the mixed region, Equipped with, Electrical equipment.

2. The plurality of first regions are positioned so as not to be adjacent to each other. The electrical equipment according to claim 1.

3. The aforementioned plurality of first regions are spaced apart from each other. The electrical equipment according to claim 1.

4. The aforementioned plurality of first regions are hydrophilic regions, The second region described above is a hydrophobic region. An electrical device according to any one of claims 1 to 3.

5. The plurality of first regions and the second region are regions that have undergone roughening treatment. The hydrophilicity in the plurality of first regions and the hydrophobicity in the second regions are brought about by the surface roughening treatment. The electrical equipment according to claim 4.

6. The aforementioned plurality of first regions are regions in which the surface free energy is higher than that of the second region. The hydrophilicity in the plurality of first regions and the hydrophobicity in the second regions are brought about by the difference in the surface free energy of the insulator. The electrical equipment according to claim 4.

7. The portion of the insulator in which the plurality of first regions are located is provided with a recess that is concave in a second direction, which is opposite to the direction in which the upper surface faces. The hydrophilicity in the plurality of first regions is provided by the recesses. The electrical equipment according to claim 4.

8. The plurality of first regions are regions with higher moisture adsorption properties than the second region. An electrical device according to any one of claims 1 to 3.

9. The plurality of first regions have hydrophilic functional groups, The water-adsorbing properties in the plurality of first regions are brought about by the hydrophilic functional groups. The electrical equipment according to claim 8.

10. The plurality of first regions have a water-absorbing material, The moisture adsorption properties in the plurality of first regions are provided by the water-absorbing material. The electrical equipment according to claim 8.

11. To manufacture an electrical device comprising an insulator and a pair of electrodes fixed to the upper surface of the insulator and arranged in positions facing each other in a first direction, In the upper surface of the insulator, at a position sandwiched between a pair of electrodes, a mixed region is formed on at least a part of the upper surface, in which a plurality of first regions and a second region that is larger than or equal to the plurality of first regions and has properties that make it less likely for conductive foreign matter to adhere to it than the plurality of first regions are mixed. Equipped with, Manufacturing methods for electrical equipment.

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