Wiring Board

Abstract

To provide other technologies for suppressing the generation or propagation of cracks in an oxide film layer on a wiring board having a base material made of a metallic material mainly composed of aluminum and an oxide film layer formed on the surface of the base material.SOLUTION: A wiring board has a base material made of a metal material mainly composed of aluminum (Al), an oxide film layer that is an anodic oxide film of the metal material and is formed on the surface of the base material, and a wiring portion having conductivity and formed on the oxide film layer, the oxide film layer has a first oxide film portion on which the wiring portion is formed and a second oxide film portion formed at a distance from the first oxide film portion and on which no wiring portion is formed, and the base material surface is exposed between the first oxide film portion and the second oxide film portion.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a wiring board. [Background technology]

[0002] Conventionally, wiring boards with high heat dissipation properties have been used as wiring boards on which elements that generate a lot of heat, such as LEDs (light emitting diodes) and power semiconductors, are mounted. As a wiring board with high heat dissipation properties, a technology has been proposed in which an aluminum substrate is coated with an alumite film to be used as an electronic substrate (hereinafter also referred to as an alumite substrate) (see, for example, Patent Documents 1 to 5). An alumite substrate can maintain the thermal conductivity and thermal diffusivity of an aluminum substrate while providing insulation, and therefore can achieve high heat dissipation. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-124324 A [Patent Document 2] JP 2012-201891 A [Patent Document 3] Patent No. 6190791 [Patent Document 4] Patent No. 6257944 [Patent Document 5] Japanese Patent Application Publication No. 59-224192 [Patent Document 6] International Publication No. 2013 / 018344 Summary of the Invention [Problem to be solved by the invention]

[0004] Next-generation automobiles will use high-brightness LEDs for many of their exterior displays (lights). The number of LEDs used in vehicles will increase dramatically, requiring higher density, and high output for daytime running lights. As the number of LEDs used increases and the output of LEDs increases, there is a demand for even higher heat dissipation from the wiring boards on which the LEDs are mounted.

[0005] Therefore, anodized aluminum substrates have been considered as wiring substrates with high heat dissipation. However, since anodized aluminum coatings have low heat resistance and cracks are likely to occur on the surface of the anodized aluminum when heated, there is a problem that it is difficult to guarantee insulation. Patent Document 1 proposes a technology to suppress the occurrence of cracks during the process of forming wiring electrodes by increasing the thickness of the aluminum substrate in the portion where the wiring electrodes are formed and thinning the anodized aluminum layer in that portion, thereby making it easier to dissipate heat generated during the process of forming wiring electrodes to the aluminum substrate. Patent Document 2 proposes a technology to realize high-temperature crack resistance by appropriately defining the chemical composition of the aluminum alloy used as the base material and the size and number of intermetallic compounds present in the anodized film, and by forming a composite film structure in which at least a part of the anodized film is coated or surface-modified with an insulator. Patent Document 4 proposes a technology to suppress cracks by providing an amorphous anodized aluminum layer and a crystallized anodized aluminum layer in this order on the surface of an aluminum alloy.

[0006] However, the anodized aluminum coating is susceptible to cracks even from minor defects, and there is a risk of cracks occurring even with the above-mentioned conventional technology.

[0007] The present invention has been made to solve the above-mentioned problems, and aims to provide another technology for suppressing the occurrence or progression of cracks in an oxide film layer in a wiring board having a base material made of a metal material mainly composed of aluminum and an oxide film layer formed on the surface of the base material. [Means for solving the problem]

[0008] The present invention has been made to solve the above-mentioned problems, and can be realized in the following forms.

[0009] (1) According to one aspect of the present invention, there is provided a wiring board comprising a substrate made of a metal material mainly composed of aluminum (Al), an oxide coating layer which is an anodized coating of the metal material and is formed on a surface of the substrate, and a conductive wiring portion formed on the oxide coating layer, the oxide coating layer having a first oxide coating portion where the wiring portion is formed and a second oxide coating portion formed apart from the first oxide coating portion and where the wiring portion is not formed, and the substrate surface is exposed between the first oxide coating portion and the second oxide coating portion.

[0010] According to this configuration, the first oxide film portion on which the wiring portion is formed and the second oxide film portion on which the wiring portion is not formed are formed at a distance from each other, and the substrate surface is exposed between the first oxide film portion and the second oxide film portion. That is, the first oxide film portion and the second oxide film portion are not connected. Therefore, even if a crack occurs in the second oxide film portion and progresses, the progress of the crack is stopped at the portion where the oxide film layer is not formed and the substrate surface is exposed, and the crack does not progress to the first oxide film portion. Therefore, it is possible to suppress cracks in the first oxide film portion, which is the product area on which the wiring portion is formed and on which electronic components are mounted, and it is possible to improve the reliability of the wiring board.

[0011] (2) According to another aspect of the present invention, there is provided a wiring board comprising a substrate made of a metal material mainly composed of aluminum (Al), an oxide coating layer which is an anodized coating of the metal material and is formed on a surface of the substrate, and a conductive wiring portion formed on the oxide coating layer, the oxide coating layer comprising a first oxide coating portion on which the wiring portion is formed, and a second oxide coating portion formed apart from the first oxide coating portion and having a power supply portion on which the substrate surface is exposed, the substrate surface being exposed between the first oxide coating portion and the second oxide coating portion.

[0012] According to this configuration, the first oxide film portion on which the wiring portion is formed and the second oxide film portion having the power supply portion with the substrate surface exposed are formed at a distance from each other, and the substrate surface is exposed between the first oxide film portion and the second oxide film portion. That is, the first oxide film portion and the second oxide film portion are not connected. Therefore, even if a crack occurs in the second oxide film portion starting from the power supply portion and progresses, the progress of the crack is stopped at the portion where the oxide film layer is not formed and the substrate surface is exposed, and the crack does not progress to the first oxide film portion. Therefore, it is possible to suppress cracks in the first oxide film portion, which is the product area where the wiring portion is formed and where electronic components are mounted, and to improve the reliability of the wiring board.

[0013] (3) In the wiring board of the above embodiment, the base material includes a first main surface on which the oxide layer is formed, a second main surface that is the reverse side of the first main surface, and a side surface that connects the first main surface and the second main surface and on which the oxide layer is not formed, and the wiring board may be such that the oxide layer is not formed on at least a portion of the periphery of the first main surface of the base material, and the base material is exposed. If an oxide layer is formed on edges, corners, etc. of the base material, the thickness of the oxide layer becomes non-uniform, and cracks are likely to occur. According to the wiring board of this embodiment, since an oxide layer is not formed on at least a portion of the periphery of the first main surface, the occurrence of cracks can be suppressed.

[0014] (4) In the wiring board of the above embodiment, the base material may have a first main surface on which the first oxide film portion is formed, a second main surface that is the opposite side of the first main surface, and a side surface connecting the first main surface and the second main surface, and the second oxide film portion may be formed on at least one of the second main surface and the side surface. In this way, the first oxide film portion on which the wiring portion is formed is formed on a different surface from the second oxide film portion, thereby making it possible to increase the area on which electronic components can be mounted.

[0015] The present invention can be realized in various forms, for example, in the form of a product including a wiring board, a method for manufacturing a wiring board, and a method for manufacturing a product including a wiring board. [Brief description of the drawings]

[0016] [Figure 1] FIG. 2 is an explanatory diagram illustrating a schematic planar configuration of the wiring board according to the first embodiment. [Diagram 2] FIG. 2 is an explanatory diagram illustrating a schematic cross-sectional configuration of the wiring board according to the first embodiment. [Diagram 3] FIG. 11 is an explanatory diagram illustrating a planar configuration of a wiring board according to a second embodiment. [Figure 4] FIG. 13 is an explanatory diagram illustrating a schematic configuration of a wiring board according to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] First Embodiment FIG. 1 is an explanatory diagram that shows a schematic planar configuration of a wiring board 100 according to a first embodiment of the present invention, and FIG. 2 is an explanatory diagram that shows a schematic cross-sectional configuration of the wiring board 100. FIG. 2 shows a cross section taken along the line AA in FIG. 1. The wiring board 100 includes a flat substrate 10 having a substantially square planar shape, an oxide coating layer 20 formed on the surface of the substrate 10, and a wiring portion 30 formed on the oxide coating layer 20. The oxide coating layer 20 includes a first oxide coating portion 21 on which the wiring portion 30 is formed, and a second oxide coating portion 22 on which the wiring portion 30 is not formed. The second oxide coating portion 22 includes a power supply portion 23 on which the surface of the substrate 10 is exposed.

[0018] The substrate 10 is made of a metal material mainly composed of aluminum (Al). Since the substrate 10 is made of a metal material mainly composed of aluminum, it has high thermal conductivity and thermal diffusivity. In this embodiment, the main component is the component with the highest mass percentage.

[0019] 2, the substrate 10 is in the form of a flat plate having a first main surface 11, a second main surface 12 which is the opposite surface to the first main surface 11, and a side surface 13 connecting the first main surface 11 and the second main surface 12. In this embodiment, a first oxide coating portion 21 and a second oxide coating portion 22 are formed on the first main surface 11 of the substrate 10, and an oxide coating layer 20 is not formed on the second main surface 12 and the side surface 13.

[0020] The oxide coating layer 20 is an oxide coating (anodized aluminum) formed by anodizing a flat plate (hereinafter also referred to as "original plate") made of a metal material mainly composed of aluminum to modify the surface. That is, in this embodiment, the oxide coating portion formed by anodizing the original plate is the oxide coating layer 20, and the unmodified base portion is the substrate 10. The oxide coating layer 20 has insulating properties.

[0021] As described above, the oxide layer 20 has one first oxide layer portion 21 on which the wiring portion 30 is formed, and two second oxide layer portions 22 on which no wiring portion 30 is formed. As shown in Fig. 1, the first oxide layer portion 21 has a planar shape of a rectangle with rounded corners, in other words, a rectangle with rounded corners. The wiring portion 30 is formed on the first oxide layer portion 21, and the first oxide layer portion 21 is an area on which electronic components are mounted (hereinafter also referred to as a product area).

[0022] The wiring section 30 is configured by laminating three kinds of metal thin films whose main components are different from each other. Specifically, a metal thin film whose main component is titanium (Ti), a metal thin film whose main component is platinum (Pt), and a metal thin film whose main component is gold (Au) are laminated in this order from the oxide film layer 20 side. Titanium has good adhesion to the oxide film layer 20, platinum has better adhesion to gold than titanium, and gold has high conductivity, anticorrosion properties, and good bondability. Therefore, according to this configuration, peeling of the wiring section 30 is suppressed, and a wiring layer that is highly conductive, anticorrosive, and has good bondability can be realized. Note that in FIG. 2, each thin film is not shown separately. The wiring section 30 can be formed by a known method such as vapor deposition or sputtering.

[0023] The two second oxide film portions 22 are formed in substantially the same shape, and as shown in FIG. 1, each has a planar shape of a rectangle with rounded corners. The wiring portion 30 is not formed on the second oxide film portion 22, and this is not an area on which electronic components are mounted. The second oxide film portion 22 has a power supply portion 23 where the surface of the base material 10 is exposed. The power supply portion 23 is a contact point with a current-carrying jig when performing the above-mentioned anodizing process, and the surface of the base material 10 is exposed even after the anodizing process is performed. The power supply portion 23 is a through hole (FIG. 2) with a planar shape of a perfect circle (FIG. 1). The planar shape of the power supply portion 23 does not have to be a perfect circle, and may be various shapes such as a substantially elliptical shape or a substantially polygonal shape. The power supply portion is also called an electrode mark, a current-carrying mark, or a jig mark for carrying electricity.

[0024] As shown in the figure, the first oxide layer portion 21 and the second oxide layer portion 22 are formed apart from each other, and the surface of the substrate 10 is exposed between the first oxide layer portion 21 and the second oxide layer portion 22. In other words, the first oxide layer portion 21 and the second oxide layer portion 22 are not connected. In other words, the first oxide layer portion 21 and the second oxide layer portion 22 are separated from each other.

[0025] The oxide coating layer 20 is anodized aluminum, and is susceptible to cracks due to vibration, heating, and the like. In particular, since the second oxide coating portion 22 has the power supply portion 23, cracks are likely to occur starting from the power supply portion 23. In this embodiment, as described above, the first oxide coating portion 21 and the second oxide coating portion 22 are provided at a distance from each other, and the surface of the base material 10 is exposed between the first oxide coating portion 21 and the second oxide coating portion 22. Therefore, even if a crack occurs in the second oxide coating portion 22 and progresses, the progress of the crack is stopped in the portion where the oxide coating layer 20 is not formed and the surface of the base material 10 is exposed, and the crack does not progress to the first oxide coating portion. Therefore, it is possible to suppress cracks in the first oxide coating portion 21, which is the product area and where wiring is formed.

[0026] 1, the oxide coating layer 20 is not formed on the peripheral portion of the first main surface 11 of the substrate 10, and the substrate 10 is exposed. In other words, the oxide coating layer 20 is formed away from the edge of the substrate 10. That is, since the oxide coating layer 20 is formed away from the end portion (edge, corner) of the substrate 10 which is likely to become the starting point of cracks due to heating or impact, cracks in the oxide coating layer 20 can be suppressed.

[0027] In the wiring board 100 of this embodiment, the first oxide film portion 21 and the second oxide film portion 22 are formed apart from each other. As such, as a method for partially forming an oxide film on the surface of the base material 10, for example, a method (first method) can be used in which anodized aluminum is formed on the entire surface of the original sheet, and then unnecessary portions (portions that expose the surface of the base material 10) are removed by wet chemical processing, laser processing, or the like. Also, for example, a method (second method) can be used in which anodized aluminum is formed on the unnecessary portions (portions that expose the surface of the base material 10) on the surface of the original sheet after masking by photolithography.

[0028] When the first oxide coating layer 21 and the second oxide coating portion 22 are formed by the first method, the thickness of the substrate 10 is substantially uniform and is thinner than the thickness of the original sheet. On the other hand, when the first oxide coating layer 21 and the second oxide coating portion 22 are formed by the second method, the thickness of the substrate 10 at the portion where the first main surface 11 of the substrate 10 is exposed (the portion shown with diagonal hatching in FIG. 1) is substantially the same as the thickness of the original sheet, and the thickness of the substrate 10 at the portion where the first oxide coating layer 21 and the second oxide coating portion 22 are formed is thinner than the portion where the first main surface 11 of the substrate 10 is exposed. In other words, when the first oxide coating layer 21 and the second oxide coating portion 22 are formed by the second method, the thickness of the substrate 10 varies partially.

[0029] In general, when anodized aluminum has defects (microscopic scratches, dents) on the coating or is formed on a protruding portion such as a corner or edge of the substrate 10, it easily cracks due to vibration or heating. Once a crack occurs in anodized aluminum, it progresses vigorously and does not stop until it hits another defect, so there is a risk that the crack will cross the substrate. In the wiring board 100 of this embodiment, the oxide coating layer 20 is anodized aluminum, and the second oxide coating portion 22 has the power supply portion 23, so that cracks are likely to occur starting from the power supply portion 23. In contrast, according to the wiring board 100 of this embodiment, the first oxide coating portion 21 and the second oxide coating portion 22 are not connected, so even if a crack occurs in the second oxide coating portion 22 and progresses, the progress of the crack is stopped at the portion where the surface of the substrate 10 is exposed, and the crack does not progress to the first oxide coating portion 21. The wiring portion 30 is formed on the first oxide film portion 21, which is a region (product region) on which electronic components are mounted. That is, according to the wiring board 100 of the present embodiment, the occurrence of cracks can be suppressed in the product region and insulation can be ensured, thereby improving the reliability of the wiring board 100.

[0030] Furthermore, as described above, when the oxide coating layer 20 is formed on the edges, corners, etc. of the base material 10, the thickness of the oxide coating layer 20 becomes non-uniform, making it prone to cracks. In contrast, according to the wiring board 100 of the present embodiment, the oxide coating layer 20 is not formed on the peripheral portion of the first main surface 11 of the base material 10 (in other words, the oxide coating layer 20 is formed away from the edges of the base material 10), so that the occurrence of cracks can be suppressed.

[0031] In addition, in the wiring board 100 of this embodiment, the oxide coating layer 20 is not formed on the peripheral portion of the first main surface 11 of the base material 10, the side surface 13, and the second main surface 12. Therefore, when the oxide coating layer 20 is formed by the above-mentioned second method, the portion where the oxide coating layer 20 is not formed is masked with a resist. When performing anodizing (anodic oxidation coating) after masking, if the end of the resist is placed on the edge or corner of the original plate, the resist may peel off. In contrast, in the wiring board 100 of this embodiment, the end of the resist is not placed on the edge or corner of the original plate, so that the peeling of the resist is more suppressed, and the unevenness of the thickness of the end of the oxide coating layer 20 can be suppressed, and defects can be suppressed. As a result, the occurrence of cracks in the oxide coating layer 20 can be suppressed.

[0032] Furthermore, the planar shape of the first oxide coating portion 21 is a rectangle with rounded corners, and no corners at which stress may concentrate are formed, making it possible to suppress the occurrence of cracks.

[0033] According to the wiring board 100 of this embodiment, cracks in the product area can be suppressed, and therefore, while the first oxide film portion 21 ensures insulation, high heat dissipation can be obtained from the base material 10, which is mainly composed of aluminum with high thermal conductivity. Therefore, for example, it can be used as a wiring board on which high-brightness LEDs that generate a large amount of heat are mounted in a high density. In addition, it can be applied to semiconductors such as CPUs (Central Processing Units), power devices, and solar cells, liquid crystals, etc.

[0034] <Second embodiment> 3 is an explanatory diagram illustrating a schematic planar configuration of a wiring board 100A of the second embodiment. The wiring board 100A of the present embodiment differs from the wiring board 100 of the first embodiment in the planar shape and arrangement of the second oxide coating portion 22A. In the embodiments described below, the same components as those in the wiring board 100 of the first embodiment are denoted by the same reference numerals, and the preceding description is to be referred to.

[0035] As shown in the figure, the second oxide film portion 22A of this embodiment has a rectangular planar shape, and is arranged so that one of the long sides of the second oxide film portion 22A coincides with one side of the first main surface 11 of the substrate 10 in the plan view shown in FIG. 3. That is, the oxide film layer 20 is not formed on a part of the peripheral portion of the first main surface 11 of the substrate 10, and the substrate 10 is exposed. Even in this case, since the first oxide film portion 21 is formed away from the edge of the substrate 10, it is possible to suppress the occurrence of cracks in the first oxide film portion 21. Furthermore, as with the wiring board 100 of the first embodiment, since the first oxide film portion 21 and the second oxide film portion 22A are not connected, even if a crack occurs in the second oxide film portion 22A, it is possible to suppress the crack from progressing to the first oxide film portion 21.

[0036] <Third embodiment> FIG. 4 is an explanatory diagram that shows a schematic configuration of a wiring board 100B of the third embodiment. FIG. 4(B) shows the first main surface 11 of the base material 10, and FIG. 4(A) shows a side surface 13L on the left side of the plane of the paper in FIG. 4(B), and FIG. 4(C) shows a side surface 13R on the right side of the plane of the paper in FIG. 4(A) and (C), respectively. The first oxide film portion 21B and the wiring portion 30 are omitted from illustration. The wiring board 100B of this embodiment differs from the wiring board 100 of the first embodiment in the planar shape of the first oxide film portion 21B, the planar shape of the second oxide film portion 22B, and their arrangement.

[0037] 4(B), the first oxide layer portion 21B has a planar shape of a square with rounded corners and has a larger area than the first oxide layer portion 21 of the first embodiment. The first oxide layer portion 21B is formed away from the edge of the substrate 10, similar to the first embodiment.

[0038] 4(A) and 4(C), the second oxide film portion 22B has a rectangular planar shape, and is formed on a portion of the side surface 13 of the substrate 10. In other embodiments, the second oxide film portion may be formed on the entire surface of the side surface 13 of the substrate 10.

[0039] According to the wiring board 100B of this embodiment, the second oxide layer portion 22B is formed on the side surface 13, which is different from the first main surface 11 on which the first oxide layer portion 21B is formed, and therefore the area of ​​the first oxide layer portion 21B can be made larger than that of the first oxide layer portion 21 of the first embodiment. In other words, the product area can be made larger.

[0040] <Modifications of this embodiment> The present invention is not limited to the above-described embodiment, and can be embodied in various forms without departing from the spirit and scope of the invention. For example, the following modifications are also possible.

[0041] The main components and configuration of the wiring section 30 are not limited to those in the above embodiment. For example, it may be formed of a single layer or a multilayer structure of metals such as Al, Au, Pt, Ti, Cu, Pd, Rh, Ni, W, Mo, Cr, Ag, or alloys thereof. Also, a conductive material such as ITO (Indium Tin Oxide) may be used.

[0042] In the above embodiment, the wiring board 100 having one first oxide layer portion 21 formed thereon has been exemplified, but two or more first oxide layer portions 21 may be formed. The wiring board may be formed as a so-called multi-piece wiring board. Even when the wiring board has two or more first oxide layer portions 21, it is sufficient that the first oxide layer portion 21 and the second oxide layer portion 22 are formed at a distance from each other, and the surface of the base material 10 is exposed between the first oxide layer portion 21 and the second oxide layer portion 22. Similarly, the number of second oxide layer portions 22 may be one, or three or more second oxide layer portions 22 may be formed.

[0043] In the above embodiment, an example has been shown in which the first oxide layer portion 21 is formed away from the edge of the substrate 10, but the end (edge) of the first oxide layer portion 21 may be formed to coincide with the edge (periphery) of the substrate 10. Even in this case, the second oxide layer portion 22 is formed away from the first oxide layer portion 21, and the surface of the substrate 10 is exposed between the second oxide layer portion 22 and the first oxide layer portion 21. Therefore, if a crack occurs in the second oxide layer portion 22, the crack can be prevented from progressing to the first oxide layer portion 21.

[0044] In the above embodiment, an example was shown in which the oxide coating layer 20 was not formed on the second main surface 12 of the base material 10, but the oxide coating layer 20 may also be formed on the second main surface 12. In this way, electronic components can be mounted on the second main surface 12 side of the base material 10 as well.

[0045] In the above embodiment, an example was shown in which the second oxide film portion 22 includes one power supply portion 23, but the second oxide film portion 22 may not include a power supply portion 23, or may include two or more power supply portions 23.

[0046] In the above embodiment, an example was shown in which the wiring portion 30 was not formed on the second oxide layer portion 22, but the wiring portion 30 may be formed. Even in this case, if a crack occurs in the second oxide layer portion 22 having the power supply portion 23, the crack can be prevented from progressing to the first oxide layer portion 21 formed at a distance from the second oxide layer portion 22.

[0047] The first oxide coating portion 21 may be formed on the first main surface 11 of the substrate 10, and the second oxide coating portion 22 may be formed on the second main surface 12. Alternatively, the first oxide coating portion 21 may be formed on the first main surface 11 of the substrate 10, and the second oxide coating portion 22 may be formed on the second main surface 12 and the side surface 13.

[0048] The planar shape of the oxide coating layer 20 is not limited to the above embodiment. For example, the first oxide coating portion 21 may be a rectangle with unchamfered corners. The planar shape of the oxide coating layer 20 may be a polygon, such as a triangle, pentagon, or hexagon, or a shape other than a polygon, such as a circle or ellipse. In the case of a polygonal shape, the corners may or may not be chamfered.

[0049] In the above embodiment, an example has been shown in which the power supply portion 23 is formed in the center of the second oxide film portion 22. However, the arrangement of the power supply portion 23 is not limited to the above embodiment, and the power supply portion 23 may be arranged, for example, at the edge of the second oxide film portion 22 (including the edge of the substrate 10).

[0050] The present invention has been described above based on the embodiments and modifications, but the above-mentioned embodiments of the invention are intended to facilitate understanding of the present invention and are not intended to limit the present invention. The present invention may be modified or improved without departing from the spirit and scope of the claims, and the present invention includes equivalents thereof. Furthermore, if a technical feature is not described as essential in this specification, it may be deleted as appropriate. [Explanation of symbols]

[0051] 10...Base material 11...First main surface 12...Second main surface 13, 13L, 13R…side 20…Oxide film layer 21...First oxide film part 21, 21B...First oxide film part 22, 22A, 22B...Second oxide film part 23…Power supply section 30…Wiring section 100, 100A, 100B...wiring board

Claims

1. A wiring board, A substrate made of a metal material mainly composed of aluminum (Al), an oxide coating layer formed on the surface of the base material, the oxide coating layer being an anodized coating of the metal material; a wiring portion having electrical conductivity and formed on the oxide film layer; Equipped with The oxide coating layer is a first oxide film portion on which the wiring portion is formed; a second oxide layer portion formed apart from the first oxide layer portion and in which the wiring portion is not formed; having the substrate surface is exposed between the first oxide film portion and the second oxide film portion, the substrate includes a first main surface on which the oxide coating layer is formed, a second main surface that is a back side of the first main surface, and a side surface connecting the first main surface and the second main surface, and a surface of the substrate is exposed at a peripheral portion of the first main surface, The second oxide film portion is formed on the side surface. Wiring board.

2. A wiring board, A substrate made of a metal material mainly composed of aluminum (Al), an oxide coating layer formed on the surface of the base material, the oxide coating layer being an anodized coating of the metal material; a wiring portion having electrical conductivity and formed on the oxide film layer; Equipped with The oxide coating layer is a first oxide film portion on which the wiring portion is formed; a second oxide film portion formed apart from the first oxide film portion and having a power supply portion at which the surface of the substrate is exposed; having The surface of the substrate is exposed between the first oxide film portion and the second oxide film portion. Wiring board.

3. 3. The wiring board according to claim 2, The substrate is a first main surface on which the oxide coating layer is formed, a second main surface which is a back surface of the first main surface, and a side surface which connects the first main surface and the second main surface and on which the oxide coating layer is not formed, The wiring board includes: The oxide coating layer is not formed on at least a part of a peripheral portion of the first main surface of the base material, and the base material is exposed. Wiring board.

4. The wiring board according to claim 2, The substrate is a first main surface on which the first oxide coating portion is formed, a second main surface which is a back surface of the first main surface, and a side surface connecting the first main surface and the second main surface, The second oxide coating portion is formed on at least one of the second main surface and the side surface. Wiring board.

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