Copper member, laminate, copper-clad laminate, and wiring board

Abstract

To provide a copper member capable of reducing transmission loss.SOLUTION: In the copper member 1 having a rugged shape, the side 1b of the projecting part of the rugged shape has a shape nearly free from eaves.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a copper member, a laminate, a copper-clad laminate, and a wiring board. [Background technology]

[0002] Copper foil is preferably used as a wiring material in wiring boards. In wiring boards, it is desirable to improve the adhesion between the resin member and the copper foil in order to ensure reliability. Conventionally, it has been known to roughen copper foil to improve the adhesion to the resin member. Plating is the main roughening method used.

[0003] Currently, mobile communication systems, such as mobile phone terminals, are transitioning from the fourth generation (4G) to the fifth generation (5G). Fifth generation mobile communication systems use higher frequency bands than fourth generation mobile communication systems. As the frequency increases, transmission loss in high-frequency circuits also increases, so wiring boards for fifth generation mobile communication systems are required to have excellent electrical properties that can handle high-frequency bands. To suppress transmission loss, it is desirable for the copper foil surface to have a low roughness. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2003 / 102277 Summary of the Invention [Problem to be solved by the invention]

[0005] Generally, when an alternating current flows through a conductor, the higher the frequency, the more difficult it becomes for the current to flow through the center of the conductor, and the more the current flows on the surface of the conductor. This is called the skin effect.

[0006] As described above, conventionally, plating has been the main method used to roughen copper foils. For example, as described in Patent Document 1, plating involves depositing copper particles on the surface of the copper foil, forming nodular projections on the surface of the copper foil. In such cases, when a current flows on the surface of the copper foil, the skin effect lengthens the path along which the current flows. This tends to increase transmission loss.

[0007] The present disclosure has been made in view of the above-described circumstances, and has as its main object to provide a copper member capable of reducing transmission loss. [Means for solving the problem]

[0008] One embodiment of the present disclosure provides a copper member having an uneven surface, in which protrusions of the uneven surface have a shape that is substantially free of overhangs.

[0009] Another embodiment of the present disclosure provides a copper member having a concave-convex shape on its surface, wherein convex portions of the concave-convex shape have a generally tapered shape.

[0010] Another embodiment of the present disclosure provides a copper member having a textured surface, wherein the kurtosis Sku of the surface of the copper member is greater than 3.5.

[0011] Another embodiment of the present disclosure provides a laminate having a base layer and a copper foil disposed on one surface of the base layer, the copper foil being the copper member described above.

[0012] Another embodiment of the present disclosure provides a copper-clad laminate having a resin layer and copper foil disposed on one or both sides of the resin layer, wherein the copper foil is the copper member described above, and the copper foil is disposed so that the surface having the uneven shape faces the resin layer.

[0013] Another embodiment of the present disclosure provides a wiring board having a resin layer and a patterned copper foil disposed on one or both sides of the resin layer, wherein the copper foil is the copper member described above, and the copper foil is disposed so that the surface having the uneven shape faces the resin layer. [Effects of the Invention]

[0014] The present disclosure has the effect of reducing transmission loss. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a schematic cross-sectional view illustrating a copper member according to the present disclosure. [Figure 2] FIG. 1 is a schematic cross-sectional view illustrating a conventional copper foil. [Figure 3] 1 is a schematic cross-sectional view illustrating a laminate according to the present disclosure. [Figure 4] 1 is a schematic cross-sectional view illustrating a laminate according to the present disclosure. [Figure 5] 1A to 1C are process diagrams illustrating a method for transferring a laminate according to the present disclosure. [Figure 6] 1 is a schematic cross-sectional view illustrating a laminate according to the present disclosure. [Figure 7] 1 is a schematic cross-sectional view illustrating a copper-clad laminate according to the present disclosure. [Figure 8] 1 is a schematic cross-sectional view illustrating a wiring board according to the present disclosure. [Figure 9] 1 is an SEM photograph of Example 1. [Figure 10] 1 is an SEM photograph of Example 2. [Figure 11] 1 is an SEM photograph of Example 3. [Figure 12] 1 is an SEM photograph of Example 4. [Figure 13] 1 is an SEM photograph of Example 5. [Figure 14] 1 is an SEM photograph of Example 6. [Figure 15] 1 is an SEM photograph of Example 7. [Figure 16] 1 is an SEM photograph of Comparative Example 1. [Figure 17] 1 is an SEM photograph of Comparative Example 2. [Figure 18] 1 is an SEM photograph of Comparative Example 3. [Figure 19] 1 is an SEM photograph of Comparative Example 4. [Figure 20] 10 is an SEM photograph of Comparative Example 5. [Figure 21] 1 is an SEM photograph of Comparative Example 6. [Figure 22] 10 is an SEM photograph of Comparative Example 7. [Figure 23] 1 is a graph showing transmission losses in an example and a comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0016] Embodiments of the present disclosure will be described below with reference to the drawings and the like. However, the present disclosure can be implemented in many different forms and should not be construed as being limited to the description of the embodiments exemplified below. Furthermore, to clarify the explanation, the drawings may show the width, thickness, shape, etc. of each part schematically compared to the actual form, but these are merely examples and do not limit the interpretation of the present disclosure. Furthermore, in this specification and each drawing, elements similar to those described above with reference to the previous drawings may be designated by the same reference numerals, and detailed descriptions may be omitted as appropriate.

[0017] In this specification, when describing a mode in which another component is placed on a certain component, the term "above" or "below" is used, unless otherwise specified, to include both a case in which another component is placed directly above or below a certain component so as to be in contact with the component, and a case in which another component is placed above or below a certain component with another component interposed therebetween. Also, in this specification, when describing a mode in which another component is placed on the surface of a certain component, the term "on the surface side" or "on the surface" is used, unless otherwise specified, to include both a case in which another component is placed directly above or below a certain component so as to be in contact with the component, and a case in which another component is placed above or below a certain component with another component interposed therebetween.

[0018] The copper member, laminate, copper-clad laminate, and wiring board according to the present disclosure will be described in detail below.

[0019] A. Copper materials The copper member in the present disclosure has three embodiments, which will be described below separately.

[0020] A-1. First embodiment of copper member The copper member of this embodiment is a copper member having an uneven surface, and the protrusions of the uneven surface have a shape that is substantially free of overhangs.

[0021] 1(a) and 1(b) are schematic cross-sectional views illustrating a copper member according to this embodiment, and FIG. 1(b) is a partially enlarged view of FIG. 1(b). As shown in FIGS. 1(a) and 1(b), the copper member 1 has an uneven shape 1a on its surface S1. The protruding portions 1b of the uneven shape 1a have a shape with almost no eaves.

[0022] As described above, plating has been the main method used to roughen copper foils. In plating, copper particles are typically deposited on the surface of a copper foil, forming an uneven surface 100a with bump-like protrusions 100b on the surface of a copper foil 100, as shown in Figures 2(a) and 2(b). The bump-like protrusions 100b may have a constricted center, forming an eave shape at the center, or a constricted base, forming an eave shape.

[0023] As mentioned above, when an AC current is passed through a conductor, the higher the frequency, the more difficult it becomes for the current to flow through the center of the conductor, and the more the current flows on the surface of the conductor. This is called the skin effect.

[0024] 2(a) and 2(b), when the protrusions 100b have a shape with eaves, the skin effect causes the path along which the current flows to become longer when the current flows on the surface of the copper foil 100. This tends to increase transmission loss.

[0025] In contrast, in this embodiment, as shown in Figures 1(a) and 1(b), the protrusion 1b has a shape with almost no overhang. In this case, when a current flows on the surface of the copper member 1, the path through which the current flows can be shortened due to the skin effect. Therefore, transmission loss can be reduced.

[0026] Furthermore, in this embodiment, since the copper member 1 has an uneven surface 1a, when a resin member is placed on the surface of the copper member 1 having the uneven surface 1a, the adhesion between the copper member and the resin member can be improved.

[0027] The copper member of this embodiment will be described in detail below.

[0028] 1.Uneven shape The copper member has an uneven surface, and the protrusions of the uneven surface have a shape with almost no eaves.

[0029] In this specification, the term "shape with almost no overhang" means that in the concave-convex shape, there is no protruding structure with a space between the top of the convex portion and the bottom of the concave portion.

[0030] Furthermore, in this specification, the phrase "the convex portions of the uneven shape have a shape that is substantially free of overhangs" means that the proportion of convex portions of the uneven shape that have a shape that is free of overhangs is 80% or more. The proportion is preferably 80% or more, and more preferably 90% or more. In other words, the uneven shape may include convex portions that have a shape with overhangs. As will be described later, in this embodiment, convex portions that have a shape without overhangs can be formed by roughening the surface of the copper foil by etching. In the case of etching, convex portions that have a shape without overhangs are likely to be formed, but convex portions that have a shape with overhangs may also be formed.

[0031] The above ratio is determined by observing a cross section of the copper member in the thickness direction using a scanning electron microscope (SEM). The ratio is the ratio of convex portions having a shape without eaves to 10 convex portions randomly selected in an SEM image at 10,000x magnification. The SEM observation conditions are appropriately selected depending on the size of the uneven shape.

[0032] The tops of the convex portions may be sharp or rounded. In particular, as shown in FIG. 1(b), it is preferable that the tops of the convex portions 1b be sharp. When the tops of the convex portions are sharp, the path along which current flows tends to be shorter due to the skin effect when current flows on the surface of the copper member, compared to when the tops of the convex portions are rounded. Therefore, transmission loss can be further reduced. Furthermore, when a resin member is disposed on the uneven surface of a copper member, if the resin constituting the resin member has low fluidity, having sharp tops of the convex portions may further enhance adhesion between the copper member and the resin member.

[0033] The uneven shape may be formed on at least a part of the surface of the copper member. The uneven shape may be formed on the entire surface of the copper member or on a part of the surface. Furthermore, the uneven surface of the copper member may have a flat portion.

[0034] 2. Surface properties of copper components (1) Kurtosis Sku Sku is one of the three-dimensional surface texture parameters specified in ISO25178-2:2012, and is an index that indicates the degree of peakedness of the height distribution from the mean plane. When Sku=3, it indicates that the height distribution is normal. When Sku>3, it indicates that the height distribution is peaked, indicating that there is a tendency for sharp peaks or valleys to be present on the surface. When Sku<3, it indicates that the height distribution has a flat shape, indicating that there is a tendency for gentle peaks or valleys to be present on the surface, or that the surface tends to be flat.

[0035] In this embodiment, the Sku of the uneven surface of the copper member is preferably greater than 3.5, more preferably 3.7 or greater, and even more preferably 3.9 or greater. When the Sku is within the above range, sharp protrusions tend to be present on the surface of the copper member. In such cases, when current flows through the surface of the copper member, the path along which the current flows tends to be shorter due to the skin effect. This further reduces transmission loss. Meanwhile, the upper limit of the Sku is not particularly limited in terms of transmission loss. When a resin member is disposed on the uneven surface of the copper member, the preferred upper limit of the Sku varies depending on the physical properties or material of the resin member or the lamination method of the copper member and the resin member. For example, the Sku may be 4.9 or less, 4.6 or less, or 4.3 or less. Depending on the physical properties or material of the resin member or the lamination method of the copper member and the resin member, if the Sku is too large, the protrusions may become too sharp, reducing the anchoring effect of the uneven surface. Specifically, the Sku is preferably greater than 3.5 and equal to or less than 4.9, and may be equal to or greater than 3.7 and equal to or less than 4.6, or may be equal to or greater than 3.9 and equal to or less than 4.3.

[0036] The Sku can be adjusted by, for example, adjusting the method or conditions for roughening the copper member. Specifically, when the surface of a copper member is roughened by etching, the Sku tends to become relatively large.

[0037] Sku is measured using a laser microscope in accordance with ISO25178-2:2012. Sku is measured without using the S filter or L filter of the Gaussian filter. Sku is the average value of the measurements taken at any five points.

[0038] (2) Maximum height Sz In this embodiment, the maximum height Sz of the uneven surface of the copper member is preferably 2.0 μm or more, more preferably 3.5 μm or more, and even more preferably 4.0 μm or more. By having Sz in the above range, the adhesion between the copper member and the resin member can be improved. On the other hand, the upper limit of Sz is not particularly limited as long as it can be formed, but is preferably 5.0 μm or less, more preferably 4.8 μm or less, and even more preferably 4.6 μm or less. By having Sz in the above range, transmission loss due to the uneven shape can be suppressed. Specifically, Sz is preferably 2.0 μm or more and 5.0 μm or less, more preferably 3.5 μm or more and 4.8 μm or less, and even more preferably 4.0 μm or more and 4.6 μm or less.

[0039] The Sz can be adjusted by, for example, adjusting the method or conditions for roughening the copper member. Specifically, when the surface of a copper foil is roughened by etching, the Sz can be set to a predetermined value or more by adjusting the etching conditions.

[0040] Sz is measured using a laser microscope in accordance with ISO25178-2:2012. When measuring Sz, Sku is measured without using the S filter or L filter of the Gaussian filter. Sz is the average value of the measurements taken at any five points.

[0041] 3. Copper materials The copper member includes copper or a copper alloy. The copper alloy is not particularly limited as long as it can be used to produce the copper member.

[0042] The form of the copper member is not particularly limited and can be appropriately selected depending on the application and manufacturing method of the copper member. The copper member may be in a sheet form or other form. Examples of the copper member include copper foil and copper plate. Among these, the copper member is preferably copper foil.

[0043] The thickness of the copper member is not particularly limited and is appropriately selected depending on the application and manufacturing method of the copper member. When the copper member is a copper foil and, as described below, the copper member is obtained from a laminate having a carrier substrate and a copper foil, the thickness of the copper foil is, for example, 0.4 μm to 35 μm, 0.6 μm to 18 μm, 0.8 μm to 12 μm, or 1 μm to 5 μm. When the copper foil has a thin thickness within the above range, it is suitable for forming fine wiring. On the other hand, when the copper member is a copper foil and has self-supporting properties, the thickness of the copper foil is, for example, 5 μm to 35 μm, 6 μm to 18 μm, or 8 μm to 12 μm.

[0044] As the copper foil, for example, rolled copper foil or electrolytic copper foil can be used.

[0045] 4.Surface The uneven surface of the copper member may have a surface portion containing selenium. The inventors of the present application have found that surface treatment of copper members using selenium results in better adhesion to a resin layer than surface treatments using other metals such as zirconium, nickel, and silver. Furthermore, surface treatment using selenium is an inorganic surface treatment, which can improve heat resistance and maintain adhesion to a resin layer even in high-temperature, high-humidity environments. While surface treatment using tin is also considered as a surface treatment using other metals, selenium has a lower environmental impact than tin. Furthermore, selenium has the advantage of being able to form a film on copper surfaces at low temperatures of around 40°C in a short time. Selenium is also a sulfur homologous element and can assume oxidation states from -2 to +6, resulting in high chemical surface reactivity.

[0046] The presence of selenium in the surface portion is determined by analysis using X-ray photoelectron spectroscopy (XPS).

[0047] The surface portions are preferably arranged partially on the uneven surface of the copper member, more specifically, the surface portions are preferably scattered on the uneven surface of the copper member.

[0048] The surface portion preferably has a plurality of particles containing selenium.

[0049] In addition, when a surface portion containing selenium is arranged on a surface of a copper member having an uneven shape, the size of the selenium-containing particles is very small compared to the size of the convex parts of the uneven shape, so it is thought that the surface portion has almost no effect on the shape of the convex parts.

[0050] The surface portion can be formed by subjecting the copper member to a surface treatment, such as plating, such as electrolytic plating or electroless plating, chemical conversion treatment, or PVD, such as vacuum deposition or sputtering.

[0051] Among these, chemical conversion treatment is preferred, and in the case of chemical conversion treatment, room temperature blackening treatment is desirable. Room temperature blackening treatment can form a surface portion in a short time by applying a blackening agent to the copper member, immersing the copper member in the blackening agent, or spray coating.

[0052] For chemical conversion treatment at room temperature, it is preferable to use a room-temperature blackening agent containing a selenium compound. A surface containing selenium can be easily formed by immersion or spray application of the room-temperature blackening agent containing a selenium compound. An example of a selenium compound is selenious acid (H2SeO3).

[0053] Furthermore, the surface portion containing selenium is preferably located on the outermost surface of the copper member.

[0054] 5.Applications Examples of applications of the copper member of this embodiment include carrier-attached copper foil, resin-coated copper foil (RCC), copper-clad laminate (CCL), wiring board, and antenna-in-package (AiP).

[0055] A-2. Second embodiment of copper member The copper member of this embodiment is a copper member having an uneven surface, and the protrusions of the uneven surface have a generally tapered shape.

[0056] 1(a) and 1(b) are schematic cross-sectional views illustrating a copper member of this embodiment, and FIG. 1(b) is a partially enlarged view of FIG. 1(b). As shown in FIGS. 1(a) and 1(b), the copper member 1 has an uneven shape 1a on its surface S1. The protruding portions 1b of the uneven shape 1a have a generally tapered shape.

[0057] As described above, plating has been the main method used to roughen copper foils. In plating, copper particles are typically deposited on the surface of a copper foil, forming an uneven surface 100a with bump-like protrusions 100b on the surface of a copper foil 100, as shown in Figures 2(a) and 2(b). The bump-like protrusions 100b may have a constricted center, forming an eave shape at the center, or a constricted base, forming an eave shape.

[0058] 2(a) and 2(b), when the protrusions 100b have a shape with eaves, the skin effect causes the path along which the current flows to become longer when the current flows on the surface of the copper foil 100. This tends to increase transmission loss.

[0059] In contrast, in this embodiment, as shown in Figures 1(a) and 1(b), the protrusion 1b has a generally tapered shape. In this case, when a current flows on the surface of the copper member 1 due to the skin effect, the path through which the current flows can be shortened. Therefore, the transmission loss can be reduced.

[0060] Furthermore, in this embodiment, since the copper member 1 has an uneven surface 1a, when a resin member is placed on the surface of the copper member 1 having the uneven surface 1a, the adhesion between the copper member and the resin member can be improved.

[0061] The copper member has an uneven surface, and the protrusions of the uneven surface have a generally tapered shape.

[0062] In this specification, the term "substantially tapered shape" refers to a shape in which the cross section of the convex portion gradually becomes thinner from the bottom to the top of the convex portion.

[0063] Furthermore, in this specification, the phrase "the convex portions of the uneven shape have a substantially tapered shape" means that the proportion of the convex portions of the uneven shape that have a tapered shape is 80% or more. This proportion is preferably 80% or more, and more preferably 90% or more. That is, the uneven shape may include convex portions with an eaves shape or convex portions that gradually become thicker from the bottom to the top of the convex portions. As will be described later, in this embodiment, convex portions with a tapered shape can be formed by roughening the surface of the copper foil by etching. While etching tends to form convex portions with a tapered shape, it is also possible that convex portions with an eaves shape or convex portions with a tapered shape may be formed.

[0064] The above ratio is determined by observing a cross section of the copper member in the thickness direction using a scanning electron microscope (SEM). The ratio is the ratio of tapered convex portions to 10 randomly selected convex portions in an SEM image at 10,000x magnification. The SEM observation conditions are appropriately selected depending on the size of the concave-convex portions.

[0065] The tops of the convex portions may be sharp or rounded. In particular, as shown in FIG. 1(b), it is preferable that the tops of the convex portions 1b be sharp. When the tops of the convex portions are sharp, the path along which current flows tends to be shorter due to the skin effect when current flows on the surface of the copper member, compared to when the tops of the convex portions are rounded. Therefore, transmission loss can be further reduced. Furthermore, when a resin member is disposed on the uneven surface of a copper member, if the resin constituting the resin member has low fluidity, having sharp tops of the convex portions may further enhance adhesion between the copper member and the resin member.

[0066] Other aspects of the copper member are the same as those described in the above section "A-1. First embodiment of copper member."

[0067] A-3. Third embodiment of copper member The copper member of this embodiment is a copper member having an uneven surface, and the kurtosis Sku of the surface of the copper member is greater than 3.5.

[0068] 1(a) and 1(b) are schematic cross-sectional views illustrating a copper member according to this embodiment, and FIG. 1(b) is a partially enlarged view of FIG. 1(b). As shown in FIGS. 1(a) and 1(b), the copper member 1 has an uneven shape 1a on its surface S1. The Sku of the surface S1 of the copper member 1 is within a predetermined range.

[0069] As mentioned above, Sku is one of the three-dimensional surface texture parameters defined in ISO25178-2:2012, and is an index that indicates the degree of peakedness of the height distribution from the mean plane. When Sku=3, it indicates that the height distribution is normal. When Sku>3, it indicates that the height distribution is peaked, indicating that there is a tendency for sharp peaks or valleys to be present on the surface. When Sku<3, it indicates that the height distribution has a flat shape, indicating that there is a tendency for gentle peaks or valleys to be present on the surface, or that the surface is flat.

[0070] In this embodiment, the Sku of the uneven surface of the copper member is greater than 3.5. Therefore, it can be said that there is a tendency for sharp protrusions to exist on the surface of the copper member. In such a case, when a current flows on the surface of the copper member, the path along which the current flows tends to become shorter due to the skin effect. This reduces transmission loss.

[0071] As described above, plating has been the main method used to roughen copper foils. In plating, copper particles are typically deposited on the surface of the copper foil, forming an uneven surface 100a with bump-like projections 100b on the surface of the copper foil 100, as shown in Figures 2(a) and 2(b). Because the bump-like projections 100b are rounded, the surface of the copper foil 100 with the bump-like projections 100b tends to have a relatively small Sku.

[0072] Furthermore, in this embodiment, since the copper member 1 has an uneven surface 1a, when a resin member is placed on the surface of the copper member 1 having the uneven surface 1a, the adhesion between the copper member and the resin member can be improved.

[0073] In this embodiment, the Sku of the uneven surface of the copper member is greater than 3.5, preferably 3.7 or greater, and more preferably 3.9 or greater. When the Sku is within the above range, sharp protrusions tend to be present on the surface of the copper member. In such cases, when current flows through the surface of the copper member, the path along which the current flows tends to be shortened due to the skin effect. This reduces transmission loss. On the other hand, the upper limit of the Sku is not particularly limited in terms of transmission loss. When a resin member is disposed on the uneven surface of the copper member, the preferred upper limit of the Sku varies depending on the physical properties or material of the resin member or the lamination method of the copper member and the resin member. For example, the Sku may be 4.9 or less, 4.6 or less, or 4.3 or less. Depending on the physical properties or material of the resin member or the lamination method of the copper member and the resin member, if the Sku is too large, the protrusions may become too sharp, reducing the anchoring effect of the uneven surface. Specifically, the Sku is preferably greater than 3.5 and equal to or less than 4.9, and may be equal to or greater than 3.7 and equal to or less than 4.6, or may be equal to or greater than 3.9 and equal to or less than 4.3.

[0074] The Sku can be adjusted by, for example, adjusting the method or conditions for roughening the copper member. Specifically, when the surface of a copper member is roughened by etching, the Sku tends to become relatively large.

[0075] The method for measuring Sku is the same as the method described in the above section "A-1. First embodiment of copper member."

[0076] The maximum height Sz of the surface of the copper member having the irregular shape is the same as that described in the above section "A-1. First embodiment of copper member."

[0077] The copper member has an uneven surface. The uneven surface is not particularly limited as long as it satisfies the above Sku, and it is particularly preferable that it satisfies the above Sz.

[0078] The tops of the convex portions of the uneven shape may be sharp or rounded. In particular, as shown in FIG. 1(b), it is preferable that the tops of the convex portions 1b are sharp. When the tops of the convex portions are sharp, the path along which current flows tends to be shorter due to the skin effect when current flows on the surface of the copper member, compared to when the tops of the convex portions are rounded. Therefore, transmission loss can be further reduced. Furthermore, when a resin member is disposed on the uneven surface of a copper member, if the resin constituting the resin member has low fluidity, having sharp tops of the convex portions can sometimes further improve adhesion between the copper member and the resin member.

[0079] Other aspects of the copper member are the same as those described in the above section "A-1. First embodiment of copper member."

[0080] B. Laminate The laminate in the present disclosure has a base layer and copper foil disposed on one surface of the base layer, and the copper foil is the copper member described above.

[0081] The laminate in the present disclosure has two embodiments, each of which will be described below.

[0082] B-1. First embodiment of laminate The laminate of this embodiment has a base layer and copper foil arranged on one side of the base layer, the copper foil being the copper member described above, the base layer being a carrier base, and the copper foil being arranged so that the side opposite to the surface having the surface shape faces the base layer.

[0083] 3 and 4 are schematic cross-sectional views illustrating an example of a laminate of this embodiment. As shown in Fig. 3 and Fig. 4, a laminate 10A has a base layer 12 and a copper foil 11 disposed on one surface of the base layer 12. The copper foil 11 is the above-mentioned copper member, and the base layer 12 is a carrier base 12A. The copper foil 11 is disposed so that a surface S2 opposite to the surface S1 having the uneven shape 1a faces the base layer 12.

[0084] The laminate of this embodiment is used for transferring copper foil. For example, after laminating the laminate and a resin layer, the carrier substrate is peeled off from the laminate, and the copper foil is transferred to one side of the resin layer. The laminate of this embodiment has the above-mentioned copper member as the copper foil, so that the transmission loss can be reduced.

[0085] Hereinafter, each component of the laminate of this embodiment will be described.

[0086] 1.Copper foil The copper foil is the copper member described above. The copper member is the same as that described above in "A. Copper member." The copper foil is arranged so that the surface opposite to the surface having the textured shape faces the base layer.

[0087] 2.Base material layer The substrate layer is a carrier substrate. The carrier substrate is a member that supports the copper foil. The carrier substrate is not particularly limited as long as it can support the copper foil, and has at least a support layer. Examples of the support layer that can be used include a metal substrate, a resin substrate, a glass substrate, a ceramic substrate, and a silicon wafer. The support layer may be rigid or flexible.

[0088] The layer structure of the carrier substrate is not particularly limited. For example, the carrier substrate may have, in order from the copper foil side, an adhesive layer and a support layer, or may have a release layer and a support layer. Below, as specific examples, a case where the carrier substrate has, in order from the copper foil side, an adhesive layer and a support layer, and the support layer is a resin substrate (first example), and a case where the carrier substrate has, in order from the copper foil side, a release layer and a support layer, and the support layer is a metal substrate, and the metal substrate is a carrier copper foil (second example) will be described.

[0089] (1) First Example The carrier substrate of this embodiment has, in this order from the copper foil side, an adhesive layer and a resin substrate.

[0090] Fig. 3 is a schematic cross-sectional view illustrating a laminate of this embodiment. The laminate 10A in Fig. 3 includes a resin base material 2, a carrier base material 12A having an adhesive layer 3 arranged on one surface of the resin base material 2, and a copper foil 11 arranged on the surface of the carrier base material 12A facing the adhesive layer 3. The copper foil 11 is the above-mentioned copper member 1. The copper foil 11 is arranged so that the surface S2 opposite to the surface S1 having the uneven shape 1a faces the carrier base material 12A.

[0091] In this embodiment, by using a resin substrate as the carrier substrate, it is possible to reduce costs compared to when a carrier copper foil is used. In particular, by using an inexpensive resin substrate, costs can be significantly reduced.

[0092] In this embodiment, the carrier substrate can be made transparent by using a resin substrate as the carrier substrate. When the carrier substrate is transparent, defects on the surface of the copper foil facing the carrier substrate can be inspected by observing the laminate from the carrier substrate side. This can increase the yield.

[0093] When a carrier copper foil is used as the carrier substrate, it is difficult to check for defects on the surface of the copper foil facing the carrier substrate.

[0094] As described above, the laminate of this embodiment is used for transferring copper foil. For example, as shown in Figures 5(a) and 5(b), after laminating a laminate 10A and a resin layer 21, the carrier substrate 12A is peeled off from the laminate 10A, and the copper foil 11 is transferred to one surface of the resin layer 21. As described above, the laminate has the copper member as the copper foil, thereby reducing transmission loss.

[0095] (a) Resin substrate The resin substrate is a member that supports the adhesive layer and the copper foil. The resin constituting the resin substrate is not particularly limited, and examples thereof include polyester resin, polyimide resin, polyamide resin, polyamideimide resin, polybenzoxazole resin, aramid resin, polystyrene resin, polyether ether ketone resin, polyphenylene sulfide resin, polyether sulfone resin, and polyarylate resin. Examples of polyester resins include polyethylene terephthalate and polyethylene naphthalate.

[0096] In particular, the resin substrate preferably has heat resistance. When the copper foil is transferred to the resin layer using the laminate of this embodiment, the laminate and the resin layer may be heated. The resin substrate having heat resistance makes the heating step possible.

[0097] When the resin substrate has heat resistance, examples of the resin constituting the resin substrate include polyimide resin, polyamide resin, polyamideimide resin, polybenzoxazole resin, aramid resin, syndiotactic polystyrene resin, polyether ether ketone resin, polyphenylene sulfide resin, polyether sulfone resin, and polyarylate resin.

[0098] The resin substrate is preferably transparent. When the resin substrate is transparent, defects on the surface of the copper foil facing the resin substrate can be inspected by observing the laminate from the resin substrate side. This can increase the yield.

[0099] When the resin substrate is transparent, the total light transmittance of the resin substrate is, for example, preferably 80% or more, more preferably 85% or more, and even more preferably 90% or more. The total light transmittance of the resin substrate is measured in accordance with JIS K7361-1:1997.

[0100] The thickness of the resin substrate is, for example, preferably 12.5 μm or more and 250 μm or less, more preferably 12.5 μm or more and 100 μm or less, and even more preferably 12.5 μm or more and 50 μm or less. If the thickness of the resin substrate is a predetermined value or more, the handleability of the laminate is improved. Furthermore, if the thickness of the resin substrate is within the above range, the carrier substrate can be easily peeled from the laminate. Furthermore, if the thickness of the resin substrate is a predetermined value or less, sufficient transparency is obtained.

[0101] (b)Adhesive layer The adhesive layer is a member disposed between the resin substrate and the copper foil. When the copper foil is transferred to the resin layer using the laminate of this embodiment, the adhesive layer and the copper foil are peeled off at the interface between them.

[0102] The adhesive layer is not particularly limited as long as it can adhere the resin substrate and the copper foil and is removable. Examples of adhesives used in the adhesive layer include acrylic adhesives, urethane adhesives, and silicone adhesives.

[0103] In particular, the adhesive layer preferably has heat resistance. When the copper foil is transferred to the resin layer using the laminate of this embodiment, the laminate and the resin layer may be heated. The heat resistance of the adhesive layer makes the heating process possible.

[0104] As the adhesive used in the adhesive layer, an acrylic adhesive is preferably used from the viewpoints of removability, heat resistance, transparency, etc. The acrylic adhesive can be appropriately selected from known acrylic adhesives and used. For example, the adhesive layer may contain a crosslinked product of an adhesive composition containing an acrylic polymer as a main component and a crosslinking agent.

[0105] The thickness of the adhesive layer is, for example, preferably 3 μm to 20 μm, more preferably 4 μm to 15 μm, and even more preferably 5 μm to 10 μm. If the thickness of the adhesive layer is a predetermined value or more, adhesion between the resin substrate and the copper foil can be ensured. Furthermore, if the thickness of the adhesive layer is a predetermined value or less, sufficient removability can be obtained.

[0106] (c) Physical properties of the carrier substrate The carrier substrate of this embodiment is preferably transparent. When the carrier substrate is transparent, defects on the surface of the copper foil on the carrier substrate side can be inspected by observing the laminate from the carrier substrate side. This can increase the yield.

[0107] When the carrier substrate is transparent, the total light transmittance of the carrier substrate is, for example, preferably 80% or more, more preferably 85% or more, and even more preferably 90% or more. The total light transmittance of the carrier substrate is measured in accordance with JIS K7361-1:1997.

[0108] (d) Manufacturing method of laminate When the laminate of this embodiment has the carrier substrate of this aspect, the manufacturing method of the laminate can include, for example, a step of arranging a copper foil on the adhesive layer side of the carrier substrate, and an etching step of etching the copper foil to reduce the thickness of the copper foil. By reducing the thickness of the copper foil by etching, the thickness of the copper foil can be made to a thickness suitable for forming fine wiring. Furthermore, a concave-convex shape can be formed on the surface of the copper foil opposite to the carrier substrate.

[0109] In the placement step, the carrier substrate and the copper foil can be bonded together by the adhesive layer, and the copper foil can be a thick electrolytic copper foil or a rolled copper foil.

[0110] In the etching step, a general copper foil etching method can be used as the copper foil etching method.

[0111] Furthermore, after the etching step, it is preferable to further perform a roughening treatment step in which the copper foil is roughened by etching. This allows the uneven shape and surface properties of the copper foil surface to be further adjusted. In the roughening treatment step, a general copper foil etching method can be used as the copper foil etching method. For example, the uneven shape and surface properties can be controlled by adjusting the concentration and temperature of the etching solution.

[0112] After the etching step, a surface portion forming step may be performed in which a surface portion containing selenium is formed on the uneven surface of the copper foil. The method for forming the surface portion in the surface portion forming step is as described above.

[0113] (2) Second Example The carrier substrate of this embodiment has, in order from the copper foil side, a release layer and a carrier copper foil.

[0114] Fig. 4 is a schematic cross-sectional view illustrating a laminate of this embodiment. The laminate 10A in Fig. 4 includes a carrier copper foil 4, a carrier substrate 12A having a release layer 5 disposed on one surface of the carrier copper foil 4, and a copper foil 11 disposed on the surface of the carrier substrate 12A facing the release layer 5. The copper foil 11 is the above-described copper member 1. The copper foil 11 is disposed so that a surface S2 opposite to the surface S1 having the uneven shape 1a faces the carrier substrate 12A.

[0115] (a) Carrier copper foil The carrier copper foil is a member that supports the release layer and the copper foil. From the viewpoint of good handleability, the thickness of the carrier copper foil is, for example, preferably 5 μm or more and 30 μm or less, more preferably 10 μm or more and 20 μm or less. Either electrolytic copper foil or rolled copper foil can be used as the carrier foil.

[0116] The carrier copper foil may be a foil made of a single metal, copper, or an alloy of copper with other metals, such as tin, chromium, silver, magnesium, nickel, zirconium, silicon, and titanium.

[0117] (b) Release layer The release layer is a member provided for the purpose of facilitating the separation of the copper foil from the carrier copper or for the purpose of providing weak adhesion. The release layer is not particularly limited, and any release layer generally used in laminates can be applied. The release layer may be a single layer or multiple layers.

[0118] B-2. Second embodiment of laminate The laminate of this embodiment has a base layer and copper foil arranged on one side of the base layer, wherein the copper foil is the copper member described above, the base layer is a resin layer, and the copper foil is arranged so that the surface having the surface shape faces the base layer.

[0119] Fig. 6 is a schematic cross-sectional view illustrating a laminate of this embodiment. As shown in Fig. 6, the laminate 10B has a base layer 12 and a copper foil 11 disposed on one surface of the base layer 12. The copper foil 11 is the above-mentioned copper member, and the base layer 12 is a resin layer 12B. The copper foil 11 is disposed so that the surface S1 having the uneven shape 1a faces the base layer 12.

[0120] The laminate of this embodiment can be obtained, for example, by applying a resin composition to the uneven surface of the copper member to form a resin layer (substrate layer). The laminate of this embodiment can also be obtained, for example, by using the first embodiment of the laminate, laminating the first embodiment of the laminate and a resin layer (substrate layer), and then peeling off the carrier substrate from the first embodiment of the laminate to transfer copper foil to one side of the resin layer (substrate layer). The laminate of this embodiment can reduce transmission loss by using the copper member described above as the copper foil.

[0121] Hereinafter, each component of the laminate of this embodiment will be described.

[0122] 1.Copper foil The copper foil is the copper member described above. The copper member is the same as that described in "A. Copper member" above. The copper foil is arranged so that the surface having the irregular shape faces the base layer. It is preferable that the copper foil is in contact with the base layer.

[0123] 2.Base material layer In this embodiment, the base layer is a resin layer. For example, a resin layer used in a wiring board can be used as the resin layer. The resin contained in the resin layer may be a thermosetting resin or a thermoplastic resin. An example of the resin is a liquid crystal polymer. One type of resin may be used alone, or two or more types may be used in combination. The resin layer may be a single layer or a multilayer.

[0124] 3. Other configurations The laminate of this embodiment only needs to have a copper foil and a resin layer, and may have any optional layer as required.

[0125] C.Copper clad laminate The copper-clad laminate of the present disclosure has a resin layer and copper foil arranged on one or both sides of the resin layer, the copper foil being the copper member described above, and the copper foil being arranged so that the surface having the uneven shape faces the resin layer.

[0126] 7(a) and 7(b) are schematic cross-sectional views illustrating copper-clad laminates according to the present disclosure. The copper-clad laminate 30 shown in FIG. 7(a) has a resin layer 31 and a copper foil 11 disposed on one side of the resin layer 31. The copper-clad laminate 30 shown in FIG. 7(b) has a resin layer 31 and a copper foil 11 disposed on both sides of the resin layer 31. The copper foil 11 is the copper member described above. The copper foil 11 is disposed so that the surface S1 having an irregular shape faces the resin layer 31.

[0127] The copper clad laminate of the present disclosure can reduce transmission loss by including the above-described copper member as the copper foil.

[0128] Hereinafter, each configuration of the copper-clad laminate according to the present disclosure will be described.

[0129] 1.Copper foil The copper foil is the copper member described above. The copper member is the same as that described in detail above in "A. Copper member." The copper foil may be disposed on one side of the resin layer or on both sides of the resin layer. It is preferable that the copper foil be in contact with the resin layer.

[0130] 2. Resin layer The resin layer includes a resin component and a fiber substrate. A laminate formed by laminating a plurality of prepregs can be used as the resin layer. The prepreg is a composite material in which a fiber substrate is impregnated with a resin component. The prepreg can be a prepreg generally used in copper-clad laminates.

[0131] 3. Copper-clad laminate The copper-clad laminate of the present disclosure may have a resin layer and copper foil disposed on one or both sides of the resin layer, and any known layer structure can be applied to the layer structure of the copper-clad laminate.

[0132] The copper clad laminate is appropriately selected depending on the layer structure of the copper clad laminate. For example, the above-mentioned laminate is placed on both sides or one side of a laminate in which a plurality of the above-mentioned prepregs are stacked, and heated and pressed as necessary, thereby transferring copper foil to one or both sides of the resin layer which is the prepreg laminate, thereby producing a copper clad laminate. The heating and pressing conditions can be appropriately set depending on the thickness of the copper clad laminate, the type of the resin layer, etc.

[0133] D. Wiring board The wiring board of the present disclosure has a resin layer and a patterned copper foil arranged on one or both sides of the resin layer, the copper foil being the copper member described above, and the copper foil being arranged so that the surface having the uneven shape faces the resin layer.

[0134] 8(a) and 8(b) are schematic cross-sectional views illustrating wiring boards according to the present disclosure. The wiring board 50 shown in FIG. 8(a) has a resin layer 51 and a patterned copper foil 11 disposed on one side of the resin layer 51. The wiring board 50 shown in FIG. 8(b) has a resin layer 51 and a patterned copper foil 11 disposed on both sides of the resin layer 51. The copper foil 11 is the copper member described above. The copper foil 11 is disposed so that the surface S1 having an uneven shape faces the resin layer 51.

[0135] The wiring board according to the present disclosure can reduce transmission loss by including the above-described copper member as the copper foil.

[0136] Hereinafter, each configuration of the wiring board in the present disclosure will be described.

[0137] 1.Copper foil The copper foil in the present disclosure is patterned. The copper foil is the copper member described above. The copper member is the same as that described above in "A. Copper member."

[0138] The copper foil may be disposed on one side of the resin layer or on both sides of the resin layer, and it is preferable that the copper foil is in contact with the resin layer.

[0139] 2. Resin layer The resin layer is the same as the resin layer in the copper-clad laminate.

[0140] 3. Wiring board The wiring board in the present disclosure may have a resin layer and a patterned copper foil disposed on one or both sides of the resin layer, and any known layer structure may be used as the layer structure of the wiring board.

[0141] Examples of the wiring board include a single-sided or double-sided wiring board, a multilayer wiring board, a flexible wiring board, a flexible wiring board, etc. The wiring board may also be a build-up wiring board.

[0142] The method for manufacturing the wiring board is appropriately selected depending on the layer structure of the wiring board.

[0143] For example, using the above-mentioned laminate, copper foil is transferred to one or both sides of a resin layer that is a prepreg to produce a copper-clad laminate, and then the copper foil is patterned to form a circuit, thereby producing a single-sided or double-sided wiring board.

[0144] Furthermore, by multiplying the single-sided or double-sided wiring board, a multilayer wiring board can be manufactured.

[0145] Furthermore, for example, a flexible wiring board can be produced by using the above-mentioned laminate, transferring copper foil onto one surface of a resin film, and then patterning the copper foil to form a circuit.

[0146] The manufacturing method of the build-up wiring board is not particularly limited, but the modified semi-additive process (MSAP) is preferred. The MSAP process is suitable for forming fine wiring.

[0147] The present disclosure is not limited to the above-described embodiments. The above-described embodiments are merely examples, and any configuration that is substantially identical to the technical idea described in the claims of the present disclosure and that provides similar effects is included within the technical scope of the present disclosure. [Example]

[0148] The present disclosure will be described in more detail below with reference to examples and comparative examples.

[0149] [Example 1] The carrier substrate was a 12.5 μm thick polyimide film (Kapton, manufactured by Toray DuPont Co., Ltd.), a 6 μm thick acrylic adhesive layer, and a release film (Somare's "Somatack EXP12.5PI1-200 (6 μm)"). An 8 μm thick copper foil (Furukawa Electric Co., Ltd.'s "NC-WS") was laminated onto the adhesive layer of the carrier substrate. The copper foil was then etched to a thickness of 3 μm using a ferric chloride-based etching solution. The copper foil was then roughened using a ferric chloride solution with a specific gravity of 4 Bh and a temperature of 40°C. This resulted in a carrier-attached copper foil.

[0150] [Example 2] A copper foil with a carrier was produced in the same manner as in Example 1, except that after etching the copper foil, the copper foil was roughened using a ferric chloride solution with a specific gravity of 8 Bh and a temperature of 40°C.

[0151] [Example 3] A copper foil with a carrier was produced in the same manner as in Example 1, except that after etching the copper foil, the copper foil was roughened using a ferric chloride solution with a specific gravity of 14 Bh and a temperature of 40°C.

[0152] [Example 4] A copper foil with a carrier was produced in the same manner as in Example 1, except that after etching the copper foil, the copper foil was roughened using a ferric chloride solution with a specific gravity of 15 Bh and a temperature of 40°C.

[0153] [Example 5] A copper foil with a carrier was produced in the same manner as in Example 1, except that after etching the copper foil, the copper foil was roughened using a ferric chloride solution with a specific gravity of 17 Bh and a temperature of 40°C.

[0154] [Example 6] A copper foil with a carrier was produced in the same manner as in Example 1, except that after etching the copper foil, the copper foil was roughened using a ferric chloride solution with a specific gravity of 20 Bh and a temperature of 40°C.

[0155] [Example 7] A copper foil with a carrier was produced in the same manner as in Example 1, except that the roughening treatment was not carried out after etching the copper foil.

[0156] [Comparative Example 1] The copper foil used was "Microthin-Ex" with a carrier manufactured by Mitsui Mining & Smelting Co., Ltd. The copper foil was roughened by plating.

[0157] Comparative Example 2 The copper foil used was "Microthin-FL" with a carrier manufactured by Mitsui Mining & Smelting Co., Ltd. The copper foil was roughened by plating.

[0158] Comparative Example 3 The rolled copper foil used was "JXHLP-II" manufactured by JX Nippon Mining & Metals Co., Ltd. The copper foil was roughened by plating.

[0159] Comparative Example 4 The copper foil used was "F2-WS" manufactured by Furukawa Electric Co., Ltd. The copper foil was roughened by plating.

[0160] Comparative Example 5 The copper foil used was "FV-WS" manufactured by Furukawa Electric Co., Ltd. The copper foil was roughened by plating.

[0161] Comparative Example 6 The copper foil used was "NC-WS" manufactured by Furukawa Electric Co., Ltd. The copper foil is smooth on both sides.

[0162] Comparative Example 7 The copper foil used was "LB9" manufactured by Fukuda Metal Foil & Powder Co., Ltd. The copper foil is smooth on both sides.

[0163] [evaluation] (1) Uneven shape The cross section of the copper foil was observed by SEM. SEM images of Examples 1 to 7 and Comparative Examples 1 to 7 are shown in Fig. 9 to Fig. 22, respectively. For the laminates of the Examples, the surface of the copper foil having an uneven shape was observed. For the copper foils of Comparative Examples 1 to 5, the roughened surface of the copper foil was observed.

[0164] (2) Sku and Sz For the copper foil surface, Sku and Sz were measured by confocal microscopy in accordance with ISO25178-2:2012 using Keyence Corporation's shape analysis laser microscopes "VK-X250 (controller)" and "VK-X260 (measuring unit)" under the following conditions. For the laminates of the examples, the measurements were carried out on the surface of the copper foil having an uneven shape. For the copper foils of Comparative Examples 1 to 5, the measurements were carried out on the roughened surface of the copper foil.

[0165] <Measurement conditions> ·Measurement area: 278μm×208μm Objective lens: 50x Laser wavelength: 661nm Measurement mode: Surface profile mode Measurement pitch: 0.13 μm Measurement quality: High accuracy mode

[0166] (3) Transmission loss Mitsubishi Gas Chemical Company, Inc.'s "GHPL-830 SH73 0.01 mmt" was used as the prepreg. For the copper foil with a carrier in the examples and comparative examples, the prepreg was sandwiched between two sheets of copper foil with a carrier and subjected to vacuum hot pressing at a vacuum of 60 Torr or less. The temperature was raised from room temperature to 110°C under a pressure of 0.5 MPa, held at 110°C for 30 minutes, and then raised to 220°C. After the temperature was raised to 220°C, the pressure was increased to 3.0 MPa, and the pressure and temperature were held for 105 minutes. After cooling while maintaining the pressure, a laminate of the copper foil with a carrier and the prepreg was produced. For the copper foil in the comparative examples, a copper foil and prepreg laminate was produced in the same manner as described above.

[0167] Next, the carrier substrate was peeled off from the laminate of the carrier-attached copper foil and the prepreg. Next, if the copper foil thickness was less than 12 μm, the copper foil was plated up to a thickness of 12 μm by electroplating.

[0168] Next, the copper foil in the laminate was patterned to fabricate a microstrip line with a wiring length of 100 mm and an impedance of 50 Ω. The measurement frequency was set to 1 GHz or more and 70 GHz or less, and the transmission loss S21 parameter was measured using a network analyzer (Keysight Technologies E8363B PNA series). The results are shown in Figure 23.

[0169] (4) Adhesion The peel strength between the copper foil and the prepreg was measured as an index of adhesion between the copper foil and the resin layer. The prepreg used was "GHPL-830 SH73 0.01 mmt" manufactured by Mitsubishi Gas Chemical Company, Inc.

[0170] The laminate of the example and the prepreg were overlapped and subjected to vacuum hot pressing. Then, the carrier substrate was peeled off to transfer the copper foil to one side of the prepreg. Next, a photosensitive resin (dry film) was attached, exposed to light, developed, and the copper foil was etched. The photosensitive resin was then peeled off to form a 1 cm wide pattern. Next, the copper foil was plated up to a thickness of 12 μm by electroplating. This resulted in a test piece.

[0171] A peel test was performed using a force gauge (Imada "ZTS-50N"), a motorized test stand (Imada "MX2-500N"), and a 90-degree peel test fixture (Imada "P900-200N") at a peel speed of 300 mm / sec, a peel angle of 90°, and a peel length of 80 mm. A time-load curve was obtained using Imada's "Force Recorder Standard" software, and the peel strength between the copper foil and the prepreg was measured from the average value of the stable portion of the time-load curve.

[0172] [Table 1]

[0173] 23, it was confirmed that when the convex portions of the uneven shape of the copper foil have a shape without an overhang and a tapered shape as in Examples 1 to 6, the transmission loss is reduced compared to when the convex portions of the uneven shape of the copper foil have an overhang shape as in Comparative Examples 1 to 5. It was also confirmed that when Sku is greater than 3.5 as in Examples 1 to 6, the transmission loss is reduced compared to when Sku is 3.5 or less as in Comparative Examples 1 to 5.

[0174] Furthermore, it was confirmed from Table 1 that in Examples 2 to 5, the adhesion between the copper foil and the resin layer was improved compared to Examples 1 and 6 because Sz was relatively large.

[0175] The present disclosure provides the following inventions. [1] A copper member having an uneven surface, The copper member, wherein the convex portions of the uneven shape have a shape with almost no overhang. [2] The copper member according to [1], wherein the proportion of the convex portions of the uneven shape that have no eaves is 80% or more. [3] A copper member having an uneven surface, The copper member has a convex portion of the concave-convex shape having a generally tapered shape. [4] The copper member according to [3], wherein the proportion of the convex portions having a tapered shape among the convex portions of the concave-convex shape is 80% or more. [5] The copper member according to any one of [1] to [4], wherein the top of the convex portion is sharp. [6] The copper member according to any one of [1] to [5], wherein the kurtosis Sku of the surface of the copper member is greater than 3.5. [7] The copper member according to any one of [1] to [6], wherein the maximum height Sz of the surface of the copper member is 2.0 μm or more. [8] A copper member having an uneven surface, A copper member having a surface kurtosis Sku of greater than 3.5. [9] The copper member according to [8], wherein the maximum height Sz of the surface of the copper member is 2.0 μm or more.

[10] The copper member according to any one of [1] to [9], wherein the copper member is a copper foil.

[11] A substrate layer and a copper foil disposed on one surface of the substrate layer, The copper foil is a copper member according to any one of [1] to [9].

[12] the substrate layer is a carrier substrate, The laminate according to

[11] , wherein the copper foil is arranged so that the surface opposite to the surface having the irregular shape faces the base layer.

[13] The laminate according to

[12] , wherein the carrier substrate has, in order from the copper foil side, an adhesive layer and a resin substrate.

[14] The laminate according to

[13] , wherein the carrier substrate has, in order from the copper member side, a release layer and a metal foil.

[15] the substrate layer is a resin layer, The laminate according to

[11] , wherein the copper foil is arranged so that the surface having the irregular shape faces the base layer.

[16] A resin layer and a copper foil disposed on one or both sides of the resin layer, The copper foil is a copper member according to any one of [1] to [9], The copper foil is arranged so that the surface having the irregular shape faces the resin layer.

[17] A resin layer and a patterned copper foil disposed on one or both sides of the resin layer, The copper foil is a copper member according to any one of [1] to [9], The wiring board is configured such that the surface having the irregularities faces the resin layer. [Explanation of symbols]

[0176] 1... Copper material 1a… Uneven shape 1b ... convex part 2...Resin substrate 3 … Adhesive layer 4... Carrier copper foil 5... Peel layer 10A, 10B ... laminate 11 … Copper foil 12...Base material layer 12A ... Carrier substrate 12B…Resin layer 21, 31, 51 ... resin layer 30... Copper-clad laminate 50... wiring board

Claims

1. A copper member having an uneven surface, A copper member, wherein the convex portions of the uneven shape have a shape with almost no overhang.

2. The copper member according to claim 1 , wherein the proportion of the projections of the uneven shape that have no eaves is 80% or more.

3. A copper member having an uneven surface, The copper member, wherein the convex portions of the concave-convex shape have a generally tapered shape.

4. The copper member according to claim 3 , wherein the ratio of the convex portions having a tapered shape to the convex portions of the uneven shape is 80% or more.

5. The copper member according to claim 1 , wherein the top of the protrusion is pointed.

6. The copper member according to any one of claims 1 to 4, wherein the kurtosis (Sku) of the surface of the copper member is greater than 3.

5.

7. The copper member according to claim 6 , wherein the maximum height Sz of the surface of the copper member is 2.0 μm or more.

8. A copper member having an uneven surface, A copper member, wherein the kurtosis Sku of the surface of the copper member is greater than 3.

5.

9. The copper member according to claim 8 , wherein the maximum height Sz of the surface of the copper member is 2.0 μm or more.

10. The copper member according to any one of claims 1 to 4, claim 8 or claim 9, wherein the copper member is a copper foil.

11. A substrate layer and a copper foil disposed on one surface of the substrate layer, A laminate, wherein the copper foil is the copper member according to any one of claims 1 to 4, claim 8, or claim 9.

12. the substrate layer is a carrier substrate, The laminate according to claim 11 , wherein the copper foil is arranged so that the surface opposite to the surface having the irregularities faces the base layer.

13. The laminate according to claim 12 , wherein the carrier substrate has, in this order from the copper foil side, an adhesive layer and a resin substrate.

14. The laminate according to claim 12 , wherein the carrier substrate has, in order from the copper member side, a release layer and a metal foil.

15. the substrate layer is a resin layer, The laminate according to claim 11 , wherein the copper foil is arranged so that the surface having the irregularities faces the base layer.

16. A resin layer and a copper foil disposed on one or both sides of the resin layer, The copper foil is a copper member according to any one of claims 1 to 4, claim 8 or claim 9, The copper foil is arranged so that the surface having the irregular shape faces the resin layer.

17. A resin layer and a patterned copper foil disposed on one or both sides of the resin layer, The copper foil is a copper member according to any one of claims 1 to 4, claim 8 or claim 9, The copper foil is arranged so that the surface having the irregularities faces the resin layer.

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