Metal-clad laminate, wiring board, and method for producing them

Abstract

To provide a metal-clad laminate having excellent adhesion between a resin film and a metal layer, a circuit board and a method for producing them.SOLUTION: A metal-clad laminate has a resin film, and a metal layer laminated on at least one surface of the resin film, which is termed the metal layer laminate face, without an adhesive interposed therebetween. The 180° peeling strength of the metal layer and the resin film is 0.6 N / mm or more.SELECTED DRAWING: Figure 1A

Description

Technical Field

[0001] The present disclosure relates to a metal-clad laminate, a wiring board, a method for manufacturing a metal-clad laminate, and a method for manufacturing a wiring board.

Background Art

[0002] In recent years, with the increasing functionality of electronic devices and the high-frequencyization of signals processed by electronic devices and the like, there has been a demand for flexible wiring boards capable of exhibiting excellent high-frequency characteristics, and metal-clad substrates capable of manufacturing such flexible wiring boards and the like. In such flexible wiring boards and the like, from the viewpoint of excellent high-frequency characteristics, flexible wiring boards using a cycloolefin polymer film as a base material, metal-clad laminates using a cycloolefin polymer film, and the like have been proposed.

[0003] Conventionally, as such a metal-clad laminate, one having an under-metal layer containing nickel, chromium, or the like formed on the surface of a cycloolefin polymer film and a copper layer formed on the surface of the under-metal layer is known (see Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the metal-clad laminate described in Patent Document 1, a metal layer (underlying metal layer and copper layer) is formed on the surface of a cycloolefin polymer film without using an adhesive. In a metal-clad laminate, the adhesion between the polymer film (resin film) and the metal layer is one of the important factors for the reliability of a flexible printed circuit board manufactured from the metal-clad laminate. On the other hand, when they are adhered with an adhesive for the purpose of improving the adhesion between the polymer film and the metal layer, the high-frequency characteristics deteriorate due to the presence of the adhesive layer composed of the adhesive. In the metal-clad laminate described in Patent Document 1, since the metal layer is formed on the surface of the cycloolefin polymer film without using an adhesive, it is possible to suppress the deterioration of the high-frequency characteristics due to the presence of the adhesive layer composed of the adhesive. However, there is a problem that the adhesion between the cycloolefin polymer film and the metal layer is insufficient.

[0006] In view of the above problems, an object of the present disclosure is to provide a metal-clad laminate, a wiring board, and a method for manufacturing them, which have excellent adhesion between a resin film and a metal layer.

Means for Solving the Problems

[0007] In order to solve the above problems, as one embodiment of the present disclosure, there is provided a metal-clad laminate including a resin film and a metal layer laminated on at least one surface of the resin film, which is the metal layer lamination surface, without using an adhesive, wherein the 180° peel strength between the metal layer and the resin film is 0.6 N / mm or more.

[0008] After removing the metal layer, it is sufficient that both the root mean square roughness (Rms) and the arithmetic mean roughness (Ra) of the metal layer stacking surface that is exposed are 50 nm or less, and it is sufficient that the haze of the resin film after removing the metal layer is 1.0 or less. A base layer formed between the metal layer and the metal layer stacking surface may be further provided, and the base layer may be an indium zinc oxide (IZO) thin film. A bonding layer composed of a molecular bonding agent formed between the metal layer and the metal layer stacking surface may be further provided. The resin film may be a cycloolefin polymer film, both surfaces of the resin film are the metal layer stacking surfaces, and the metal layer may be laminated on each of the two metal layer stacking surfaces without an adhesive.

[0009] A pattern having recesses and protrusions is formed on the metal layer stacking surface of the resin film, and the metal layer may be laminated so as to fill the recesses and cover the metal layer stacking surface.

[0010] As one embodiment of the present disclosure, a wiring board including a wiring layer formed by etching the metal layer of the above metal-clad laminate is provided.

[0011] As one embodiment of the present disclosure, a wiring board including a wiring layer formed as a portion embedded in the recess is provided by removing the metal layer so as to expose the top of the protrusion of the pattern of the above metal-clad laminate.

[0012] As one embodiment of the present disclosure, a wiring board manufactured from the above metal-clad laminate and having a wiring layer, wherein the wiring layer has a laminated structure of at least two layers, and one of the two layers constituting the wiring layer is a layer formed by etching the metal layer of the above metal-clad laminate, and the other of the two layers constituting the wiring layer is a layer laminated on the layer formed by etching the metal layer of the above metal-clad laminate is provided.

[0013] As one embodiment of the present disclosure, there is provided a method for manufacturing a metal-clad laminate in which a metal layer is formed without an adhesive on at least one surface of a resin film, i.e., on the metal layer laminated surface. The method includes a step of forming the metal layer without an adhesive on the metal layer laminated surface of the resin film. The root mean square roughness (RMS) and the arithmetic mean roughness (Ra) of the metal layer laminated surface of the resin film are both 50 nm or less, and the 180° peel strength between the metal layer and the resin film is 0.6 N / mm or more.

[0014] It is sufficient that both the root mean square roughness (Rms) and the arithmetic mean roughness (Ra) of the metal layer laminated surface of the resin film after removing the metal layer from the metal-clad laminate are 50 nm or less, and it is sufficient that the haze of the resin film after removing the metal layer from the metal-clad laminate is 1.0 or less. The method may further include a step of forming an underlayer on the metal layer laminated surface. The step of forming the metal layer may be a step of forming the metal layer on the underlayer formed on the metal layer laminated surface. As the underlayer, a zinc indium oxide (IZO) thin film may be formed on the metal layer laminated surface. The method may further include a step of forming a bonding layer on the metal layer laminated surface. The step of forming the metal layer may be a step of bonding the resin film and the metal layer through the bonding layer formed on the metal layer laminated surface. The resin film may be a cycloolefin polymer film. Both surfaces of the resin film are the metal layer laminated surfaces, and in the step of forming the metal layer, the metal layer may be formed on each of the two metal layer laminated surfaces without an adhesive.

[0015] A pattern having recesses and protrusions is formed on the metal layer laminated surface of the resin film, and in the step of forming the metal layer, the metal layer may be formed so as to fill the recesses and cover the protrusions of the pattern.

[0016] As one embodiment of the present disclosure, there is provided a method for manufacturing a wiring substrate including a step of forming a wiring layer by etching the metal layer of the metal-clad laminate manufactured by the method for manufacturing the metal-clad laminate. The root mean square roughness (RMS) and the arithmetic mean roughness (Ra) of the resin film exposed after etching the metal layer may both be 50 nm or less, and the haze of the resin film exposed after etching the metal layer may be 1.0 or less.

[0017] As one embodiment of the present disclosure, there is provided a method for manufacturing a wiring substrate including a step of forming a wiring layer by chemically mechanically polishing the metal layer so as to expose the top of the convex portion of the pattern of the metal-clad laminate manufactured by the method for manufacturing the metal-clad laminate.

[0018] As one embodiment of the present disclosure, there is provided a method for manufacturing a wiring substrate including a step of forming a resist pattern having an opening on the metal layer of the metal-clad laminate manufactured by the method for manufacturing the metal-clad laminate, a step of forming a metal wiring layer in the opening of the resist pattern, a step of removing the resist pattern, and a step of etching the metal layer exposed by the removal of the resist pattern.

Advantages of the Invention

[0019] According to the present disclosure, it is possible to provide a metal-clad laminate, a wiring substrate, and methods for manufacturing them, which have excellent adhesion between a resin film and a metal layer.

Brief Description of the Drawings

[0020]

Figure 1A

Figure 1B

Figure 2A

Figure 2B

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Figure 3B

Figure 3C

Figure 3D

Figure 3E

Figure 3F

Figure 3G

Figure 3H

Figure 4A

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Figure 5A

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Figure 6A

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Figure 8A

Figure 8B

DETAILED DESCRIPTION OF THE INVENTION

[0021] Embodiments of the present disclosure will be described with reference to the drawings. In the drawings, for ease of understanding, the shape, scale, aspect ratio of length and width, etc. of each part may be changed or exaggerated from the actual object. The numerical range represented by "~" in this specification, etc. means a range including each of the numerical values described before and after "~" as the lower limit value and the upper limit value. In this specification, etc., terms such as "film", "sheet", "plate", etc. are not mutually distinguished based on the difference in name. For example, "plate" is a concept including members that can generally be called "sheet" and "film".

[0022] FIG. 1A and FIG. 1B are cross-sectional views showing the schematic configuration of the metal-clad laminate according to this embodiment, and FIGS. 2A to 2C are cross-sectional views showing the schematic configuration of other aspects of the metal-clad laminate according to this embodiment.

[0023] The metal-clad laminate 1 according to this embodiment includes a resin film 2 having a first surface 21 and a second surface 22 located on the opposite side of the first surface 21, and metal layers 3 laminated on the first surface 21 and the second surface 22 of the resin film 2 without an adhesive therebetween, with each of the first surface 21 and the second surface 22 as the metal layer lamination surface. That is, the metal-clad laminate 1 according to this embodiment does not include an adhesive layer composed of an adhesive between the resin film 2 and the metal layer 3. The metal-clad laminate 1 according to this embodiment has a 180° peel strength of 0.6 N / mm or more, preferably 0.7 N / mm to 3.0 N / mm, more preferably 1.0 N / mm to 2.5 N / mm. The 180° peel strength may be a value measured according to the 180° peel strength test specified in JIS-K-6854. In this embodiment, the adhesive means a resin-based primer capable of adhering the resin film 2 and the metal layer 3, and examples thereof include an acrylic resin-based primer, a polyester resin-based primer, and an epoxy resin-based primer.

[0024] The resin film 2 may be any film generally used as a wiring board. For example, it may be a polyester resin board such as a polyethylene terephthalate (PET) board, a polyimide resin board such as a polyimide board, an acrylic resin board such as a polymethyl methacrylate board, a polycarbonate resin board, a cycloolefin copolymer board, a polyolefin resin board such as a cycloolefin polymer board, a fluororesin board such as a perfluoroalkoxy alkane (PFA) board, or other flexible boards. In particular, it is preferable to use a polyolefin resin board such as a cycloolefin copolymer board or a cycloolefin polymer board, which has excellent high-frequency characteristics, or a fluororesin board such as a perfluoroalkoxy alkane (PFA) board as the resin film 2. Further, the resin film 2 may be a rigid-flexible board having a flexible portion made of a flexible material (e.g., the above resin material such as cycloolefin polymer) constituting the above flexible board and a rigid portion made of a rigid material (e.g., glass).

[0025] The planar shape of the resin film 2 when viewed from the first surface 21 side or the second surface 22 side is not particularly limited, and may be, for example, a substantially rectangular shape, an elongated sheet shape, or the like. Further, the size and thickness of the resin film 2 are not particularly limited. For example, when the metal-clad laminate 1 according to the present embodiment is used for manufacturing a wiring board, the size of the resin film 2 may be equal to or larger than the size required in an electronic device or the like in which the wiring board is used, and the thickness of the resin film 2 may be appropriately set according to the thickness required in an electronic device or the like in which the wiring board is used. Note that the size of the resin film 2 means the lengths in one direction (e.g., the longitudinal direction) and the direction orthogonal thereto (e.g., the lateral direction) when the planar shape of the resin film 2 is a substantially rectangular shape.

[0026] The root mean square roughness (Rms) and the arithmetic mean roughness (Ra) of the first surface 21 and the second surface 22 of the resin film 2 may both be 50 nm or less, preferably 0.5 nm to 10 nm. When the root mean square roughness (Rms) and the arithmetic mean roughness (Ra) of the first surface 21 and the second surface 22 of the resin film 2 are relatively small (for example, 50 nm or less), and the first surface 21 and the second surface 22 have high flatness, the flatness of the surface of the metal layer 3 facing the first surface 21 and the second surface 22 of the resin film 2 (the surface closest to the resin film 2) is improved. As a result, it is possible to reduce the transmission loss of the wiring board manufactured from the metal-clad laminate 1 according to the present embodiment and reduce the resistance of the wiring in the wiring board. On the other hand, when the root mean square roughness (Rms) and the arithmetic mean roughness (Ra) of the first surface 21 and the second surface 22 of the resin film 2 are relatively small (for example, 50 nm or less), the adhesion between the resin film 2 and the metal layer 3 tends to decrease. However, in the present embodiment, even if both the root mean square roughness (Rms) and the arithmetic mean roughness (Ra) are relatively small, the adhesion between the resin film 2 and the metal layer 3 can be improved. The root mean square roughness (Rms) and the arithmetic mean roughness (Ra) may be values obtained using a non-contact three-dimensional surface shape measuring device (for example, NV6300 MICROSCOPE manufactured by Zygo Corporation, etc.).

[0027] The haze (Hz) of the resin film 2 may be, for example, 1.0 or less, preferably 0.7 or less, and more preferably 0.1 to 0.5. When the haze (Hz) of the resin film 2 is 1.0 or less, when manufacturing a wiring board in which wiring is difficult to visually recognize from the metal-clad laminate 1 according to the present embodiment, the transparency of the wiring board (transparency in the visible light region (wavelength 380 nm to 780 nm)) can be ensured. Therefore, the metal-clad laminate 1 according to the present embodiment can be particularly preferably used for manufacturing wiring boards that require transparency, such as touch panels and planar heaters. The haze (Hz) may be a value obtained in accordance with JIS-K-7136 using a haze meter (for example, HM-150 manufactured by Murakami Color Technology Laboratory, etc.).

[0028] The metal layer 3 has a first metal layer 31 laminated on the first surface 21 of the resin film 2 and a second metal layer 32 laminated on the second surface 22. The metal material contained in the metal layer 3 (the first metal layer 31 and the second metal layer 32) may be appropriately set according to the use of the metal-clad laminate 1 according to this embodiment, etc., and examples thereof include one or more selected from copper, iron, nickel, cobalt, molybdenum, tungsten, titanium, and aluminum. For example, when the metal-clad laminate 1 according to this embodiment is used for manufacturing a wiring board, the metal layer 3 may be a copper layer or the like having excellent conductivity. Also, the thickness of the metal layer 3 (the first metal layer 31 and the second metal layer 32) may be appropriately set according to the use of the metal-clad laminate 1 according to this embodiment, etc. When the metal-clad laminate 1 according to this embodiment is used for manufacturing a wiring board, the thickness of the metal layer 3 may be appropriately set according to the characteristic impedance of the wiring board. For example, it may be about 1 μm to 50 μm, and preferably about 12 μm to 35 μm. In the wiring layer 6 (the first wiring layer 61 and the second wiring layer 62) in the wiring board 10 manufactured using the metal-clad laminate 1 according to this embodiment, when it includes a second layer 612, 622 formed from the metal layer 3 and a third layer 613, 623 formed on the second layer 612, 622 (see FIG. 4B), the thickness of the metal layer 3 in the metal-clad laminate 1 may be set according to the characteristic impedance of the wiring board 10 in consideration of the thickness of the third layer 613, 623. Note that the metal layer 3 (the first metal layer 31 and the second metal layer 32) may have a laminated structure of an electroless metal plating layer or a sputter metal layer located on the resin film 2 side and an electrolytic metal plating layer located on the electroless metal plating layer or the sputter metal layer. The electroless metal plating layer or the sputter metal layer functions as a seed layer when forming the electrolytic metal plating layer by electrolytic plating. In this case, the metal material contained in the electroless metal plating layer or the sputter metal layer and the metal material contained in the electrolytic metal plating layer may be the same metal material or different metal materials.

[0029] In the metal-clad laminate 1 according to this embodiment, an underlayer 4 may be provided between the resin film 2 and the metal layer 3 (see FIG. 1A). By providing the underlayer 4 between them, even if the first surface 21 and the second surface 22 of the resin film 2 have high flatness (for example, both the root mean square roughness (Rms) and the arithmetic mean roughness (Ra) are 50 nm or less), the adhesion between the resin film 2 and the metal layer 3 can be improved. Specifically, as shown in FIG. 1A, a first underlayer 41 is provided between the first surface 21 of the resin film 2 and the first metal layer 31, and a second underlayer 42 is provided between the second surface 22 of the resin film 2 and the second metal layer 32.

[0030] Examples of the material constituting the underlayer 4 (the first underlayer 41 and the second underlayer 42) include metal oxides such as indium zinc oxide (IZO), indium tin oxide (ITO), and zinc oxide (ZnO), oxide semiconductor materials such as tin oxide-based (SnO2-based), titanium oxide-based (TiO2-based), and IGZO. The film thickness of the underlayer 4 is not particularly limited, but it may be 4 nm or more, and may be about 8 nm to 20 nm. If the film thickness of the underlayer 4 is less than 4 nm, island-shaped portions not covered by the constituent material of the underlayer 4 will exist on the first surface 21 and the second surface 22 of the resin film 2, and the adhesion strength (180° peel strength) between the metal layer 3 and the resin film 2 may be extremely reduced.

[0031] In the metal-clad laminate 1 according to the present embodiment, instead of the base layer 4, a bonding layer 5 (first bonding layer 51 and second bonding layer 52) for bonding the resin film 2 and the metal layer 3 may be provided (see FIG. 1B). The bonding layer 5 is formed by chemically bonding a molecular bonding agent to the first surface 21 and the second surface 22 which are the metal layer laminated surfaces of the resin film 2. By chemically bonding the metal layer 3 to the molecular bonding agent constituting the bonding layer 5, the metal-clad laminate 1 can be manufactured. Examples of the above molecular bonding agent include triazine thiol-based compounds. In addition, after performing pretreatment such as corona discharge treatment, atmospheric pressure plasma treatment, UV irradiation treatment, etc. on the first surface 21 and the second surface 22 which are the metal layer laminated surfaces of the resin film 2, a solution containing a molecular bonding agent (for example, an aqueous solution of a molecular bonding agent, etc.) is brought into contact with the first surface 21 and the second surface 22 of the resin film 2 after the pretreatment to form the bonding layer 5, and the metal layer 3 may be bonded to the bonding layer 5 by a plating method or the like.

[0032] As described above, the metal-clad laminate 1 according to the present embodiment has a structure in which the metal layer 3 (first metal layer 31 and second metal layer 32) is laminated on both surfaces (first surface 21 and second surface 22) of the resin film 2 via the base layer 4 (first base layer 41 and second base layer 42) or the bonding layer 5 (first bonding layer 51 and second bonding layer 52). Thus, the adhesion of the metal layer 3 to the resin film 2 can be improved, and a 180° peel strength of 0.6 N / mm or more can be exhibited. Further, since the metal layer 3 is laminated on both surfaces of the resin film 2 without using an adhesive, excellent high-frequency characteristics can be exhibited in the wiring board 10 (see FIGS. 4A to 4C) manufactured from the metal-clad laminate 1.

[0033] The metal-clad laminate 1 according to this embodiment is not limited to the above-described aspect. For example, the metal-clad laminate 1 may have a configuration in which a metal layer 3 (e.g., a first metal layer 31) is laminated on one surface (e.g., the first surface 21) of the resin film 2 via an underlayer 4 (e.g., a first underlayer 41) or a bonding layer 5 (e.g., a first bonding layer 51) (see FIG. 2A). Note that the metal-clad laminate 1 according to this embodiment may have a configuration in which the metal layer 3 is provided on one surface (e.g., the first surface 21) or both surfaces (the first surface 21 and the second surface 22) of the resin film 2 without any of the underlayer 4 and the bonding layer 5. In this case, a metal foil such as a copper foil may be used as the metal layer 3. However, when the metal foil is bonded to one surface or both surfaces of the resin film 2, the surface roughness (root mean square roughness Rms and arithmetic mean roughness Ra) of the first surface 21 and / or the second surface 22 of the resin film 2 is affected by the surface roughness of the metal foil in contact with the first surface 21 and / or the second surface 22, and the surface roughness (root mean square roughness Rms and arithmetic mean roughness Ra) of the first surface 21 and / or the second surface 22 of the resin film 2 after removing the metal foil as the metal layer 3 from the metal-clad laminate 1 becomes relatively large (e.g., both the root mean square roughness Rms and the arithmetic mean roughness Ra exceed 50 nm). Therefore, in this embodiment, as the metal foil, one having both the root mean square roughness Rms and the arithmetic mean roughness Ra of 50 nm or less can be used.

[0034] Further, as shown in FIG. 2B, the metal-clad laminate 1 according to the present embodiment may include a pattern 9 (e.g., a resist pattern) having recesses 91 and protrusions 92 (see FIG. 3D) on the first surface 21 and the second surface 22 of the resin film 2, and a metal layer 3 (a first metal layer 31 and a second metal layer 32) laminated so as to fill the recesses 91 of the pattern 9 and cover the entire pattern 9. In the case of the metal-clad laminate 1 of this aspect, by removing the metal layer 3 so as to expose the tops of the protrusions 92 of the pattern 9 and patterning the base layers 41, 42 (or the bonding layers 51, 52), a wiring substrate 10 (see FIG. 4A) in which a wiring layer 6 (a first wiring layer 61 and a second wiring layer 62) formed of the metal layer 3 (the first metal layer 31 and the second metal layer 32) that fills the recesses 91 of the pattern 9 is formed can be manufactured. In the metal-clad laminate 1 of this aspect (see FIG. 2B), the width W of the recesses 91 of the pattern 9 provided on the first surface 21 and the second surface 22 of the resin film 2 91 and the pitch P9 of the pattern 9 (see FIG. 3D) determine the width W 61 ,W 62 and the pitch P 61 ,P 62 of the wiring layer 6 (the first wiring layer 61 and the second wiring layer 62) in the wiring substrate 10 manufactured from the metal-clad laminate 1. Therefore, the width W 91 and the pitch P9 of the recesses 91 may be appropriately set according to the width W 61 ,W 62 and the pitch P 61 ,P 62 required for the wiring layer 6 (the first wiring layer 61 and the second wiring layer 62) in the wiring substrate 10 manufactured from the metal-clad laminate 1.

[0035] Furthermore, as shown in FIG. 2C, the metal-clad laminate 1 according to the present embodiment may include a pattern 9 (e.g., a resist pattern) having recesses 91 and protrusions 92 (see FIG. 3F) formed on each of the first surface 21 and the second surface 22 of the resin film 2, a first underlayer 41 and a second underlayer 42 (a first bonding layer 51 and a second bonding layer 52) formed at least on the first surface 21 and the second surface 22 (the bottom surface of the recess 91 of the pattern 9) of the resin film 2 exposed from the recess 91 of the pattern 9, and a metal layer 3 (a first metal layer 31 and a second metal layer 32) laminated so as to fill the recess 91 of the pattern 9 and cover the entire pattern 9. In the case of the metal-clad laminate 1 of this aspect, by removing the metal layer 3 so as to expose the top of the protrusion 92 of the pattern 9, a wiring substrate 10 (see FIG. 4C) in which a wiring layer 6 (a first wiring layer 61 and a second wiring layer 62) constituted by the metal layer 3 (the first metal layer 31 and the second metal layer 32) filling the recess 91 of the pattern 9 is formed can be manufactured. In the metal-clad laminate 1 of this aspect (see FIG. 2C), the width W of the recess 91 of the pattern 9 provided on the first surface 21 and the second surface 22 of the resin film 2 91 and the pitch P9 of the pattern 9 (see FIG. 3F) determine the width W of the wiring layer 6 (the first wiring layer 61 and the second wiring layer 62) in the wiring substrate 10 manufactured from the metal-clad laminate 1 61 ,W 62 and the pitch P 61 ,P 62 . Therefore, the width W of the recess 91 91 and the pitch P9 may be appropriately set according to the width W of the wiring layer 6 (the first wiring layer 61 and the second wiring layer 62) required in the wiring substrate 10 manufactured from the metal-clad laminate 1 61 ,W 62 and the pitch P 61 ,P 62 . Note that the material constituting the pattern 9 is not particularly limited, and for example, a known resist material or the like may be used, and preferably, a resist material having transparency (a transmittance of visible light (light having a wavelength of 380 nm to 780 nm) of 90% or more) and a haze (Hz) of 1.0 or less may be used.

[0036] The metal-clad laminate 1 according to this embodiment can be manufactured, for example, as follows. FIGS. 3A and 3B are cross-sectional views showing each step of the manufacturing method of the metal-clad laminate according to this embodiment.

[0037] First, a resin film 2 having a first surface 21 and a second surface 22 located on the opposite side of the first surface 21 is prepared, and an underlayer 4 (a first underlayer 41 and a second underlayer 42) or a bonding layer 5 (a first bonding layer 51 and a second bonding layer 52) is formed on each of the first surface 21 and the second surface 22 of the resin film 2 (see FIG. 3A). As a method for forming the underlayer 4 (the first underlayer 41 and the second underlayer 42), for example, a sputtering method using a metal oxide, which is a constituent material of the underlayer 4, as a target substance may be used. Further, as a method for forming the bonding layer 5 (the first bonding layer 51 and the second bonding layer 52), a method such as bringing an aqueous solution containing a molecular bonding agent (for example, a triazine thiol-based compound) constituting the bonding layer 5 into contact with the first surface 21 and the second surface 22 of the resin film 2 may be used.

[0038] Next, a sputtered metal layer or an electroless plating layer is formed on the underlayer 4 (the first underlayer 41 and the second underlayer 42) or the bonding layer 5 (the first bonding layer 51 and the second bonding layer 52) formed on the first surface 21 and the second surface 22 of the resin film 2 by a sputtering method using the constituent material of the metal layer 3 as a target substance or an electroless plating treatment. When forming a sputtered metal layer or an electroless plating layer on the bonding layer 5, a catalyzing treatment for depositing a Pd catalyst or the like on the bonding layer 5 may be performed before forming the sputtered metal layer or the electroless plating layer. Then, an electrolytic plating layer is formed by an electrolytic metal plating treatment using the sputtered metal layer or the electroless plating layer and the underlayer 4 (the first underlayer 41 and the second underlayer 42) or the bonding layer 5 (the first bonding layer 51 and the second bonding layer 52) as a seed layer, whereby a first metal layer 31 composed of a sputtered metal layer or an electroless plating layer and an electrolytic plating layer is formed on the first underlayer 41 or the first bonding layer 51, and a second metal layer 32 composed of a sputtered metal layer or an electroless plating layer and an electrolytic plating layer is formed on the second underlayer 42 or the second bonding layer 52 (see FIG. 3B). In this way, the metal-clad laminate 1 according to this embodiment (see FIGS. 1A and 1B) is manufactured.

[0039] Another aspect of the metal-clad laminate 1 according to this embodiment (see FIG. 2B) can be manufactured, for example, as follows. FIGS. 3C to 3E are cross-sectional views showing each step of the manufacturing method of another aspect of the metal-clad laminate according to this embodiment.

[0040] First, a resin film 2 having a first surface 21 and a second surface 22 located on the opposite side of the first surface 21 is prepared, and an underlayer 4 (a first underlayer 41 and a second underlayer 42) or a bonding layer 5 (a first bonding layer 51 and a second bonding layer 52) is formed on each of the first surface 21 and the second surface 22 of the resin film 2 (see FIG. 3C). As a method for forming the underlayer 4 (the first underlayer 41 and the second underlayer 42), for example, a sputtering method using a metal oxide, which is a constituent material of the underlayer 4, as a target material may be used. Further, as a method for forming the bonding layer 5 (the first bonding layer 51 and the second bonding layer 52), a method in which an aqueous solution containing a molecular bonding agent (for example, a triazine thiol-based compound) constituting the bonding layer 5 is brought into contact with the first surface 21 and the second surface 22 of the resin film 2 may be used.

[0041] Next, a pattern 9 (for example, a resist pattern) having concave portions 91 and convex portions 92 is formed on the underlayer 4 or the bonding layer 5 formed on each of the first surface 21 and the second surface 22 of the resin film 2 (see FIG. 3D). The method for forming the pattern 9 is not particularly limited. For example, when the pattern 9 is a resist pattern, a resist layer is formed on the underlayer 4 or the bonding layer 5 by a conventionally known coating film forming method (die coating, spin coating, etc. of a resist material, lamination of a dry film resist, etc.), and the resist layer is patterned (photolithography method, imprint lithography method, etc.), or the pattern 9 may be formed by printing of a resist material or the like.

[0042] Then, on the resin film 2 having the pattern 9 formed on the first surface 21 and the second surface 22, a sputtered metal layer or an electroless plating layer is formed by a sputtering method using the constituent material of the metal layer 3 as a target substance or an electroless plating process. Thereafter, a metal plating layer (electrolytic plating layer or electroless plating layer) is formed so as to fill the recess 91 of the pattern 9 and cover the entire pattern 9, thereby forming a metal layer 3 (first metal layer 31 and second metal layer 32) composed of a sputtered metal layer and a metal plating layer on the base layer 4 or the bonding layer 5 (see FIG. 3E). In this way, the metal-clad laminate 1 according to the present embodiment (see FIG. 2B) is manufactured. In the aspect shown in FIG. 3E, a metal plating layer is formed so as to cover the entire pattern 9, but the present invention is not limited to this aspect. For example, a metal plating layer may be formed so as to fill the recess 91 of the pattern 9 but not cover the entire pattern 9 and expose the top of the convex portion 92 of the pattern 9. In this case, the film thickness of the metal plating layer may be the same as the height of the convex portion 92 of the pattern 9 or smaller than the height of the convex portion 92 of the pattern 9.

[0043] Another aspect of the metal-clad laminate 1 according to the present embodiment (see FIG. 2C) can be manufactured, for example, as follows. FIGS. 3F to 3H are cross-sectional views showing each step of a manufacturing method of another aspect of the metal-clad laminate according to the present embodiment.

[0044] First, a resin film 2 having a first surface 21 and a second surface 22 located on the opposite side of the first surface 21 is prepared, and a pattern 9 (for example, a resist pattern) having a recess 91 and a convex portion 92 is formed on each of the first surface 21 and the second surface 22 of the resin film 2 (see FIG. 3F). The method of forming the pattern 9 is not particularly limited. For example, when the pattern 9 is a resist pattern, a resist layer may be formed on the first surface 21 and the second surface 22 by a conventionally known coating film forming method (die coating, spin coating, etc. of a resist material, lamination of a dry film resist, etc.), and the resist layer may be patterned (photolithography method, imprint lithography method, etc.), or the pattern 9 may be formed by printing of a resist material or the like.

[0045] Next, a base layer 4 (a first base layer 41 and a second base layer 42) or a bonding layer 5 (a first bonding layer 51 and a second bonding layer 52) is formed on the first surface 21 and the second surface 22 (the bottom surface of the recess 91 of the pattern 9) of the resin film 2 exposed from the recess 91 of the pattern 9 (see FIG. 3G). As a method for forming the base layer 4 (the first base layer 41 and the second base layer 42), for example, a sputtering method using a metal oxide, which is a constituent material of the base layer 4, as a target material may be used. Further, as a method for forming the bonding layer 5 (the first bonding layer 51 and the second bonding layer 52), a method in which an aqueous solution containing a molecular bonding agent (for example, a triazine thiol-based compound) constituting the bonding layer 5 is brought into contact with the first surface 21 and the second surface 22 of the resin film 2 may be used. Note that the base layer 4 or the bonding layer 5 may be formed at least on the bottom surface of the recess 91 of the pattern 9, but may also be formed on the side surface and the top of the convex portion 92 of the pattern 9.

[0046] Then, a sputtered metal layer or an electroless plating layer is formed on the resin film 2 having the pattern 9 and the base layer 4 (or the bonding layer 5) formed on the first surface 21 and the second surface 22 by a sputtering method using a constituent material of the metal layer 3 as a target material or an electroless plating treatment. Thereafter, a metal plating layer (an electroplating layer or an electroless plating layer) is formed so as to fill the recess 91 of the pattern 9 and cover the entire pattern 9, thereby forming a metal layer 3 (a first metal layer 31 and a second metal layer 32) composed of a sputtered metal layer and a metal plating layer on the base layer 4 or the bonding layer 5 (see FIG. 3H). In this way, the metal-clad laminate 1 according to the present embodiment (see FIG. 2C) is manufactured. Note that, in the aspect shown in FIG. 3H, a metal plating layer is formed so as to cover the entire pattern 9, but the present invention is not limited to this aspect. For example, a metal plating layer may be formed so as to fill the recess 91 of the pattern 9 but not cover the entire pattern 9 and expose the top of the convex portion 92 of the pattern 9. In this case, the film thickness of the metal plating layer may be the same as the height of the convex portion 92 of the pattern 9 or may be smaller than the height of the convex portion 92 of the pattern 9.

[0047] Next, a wiring board 10 manufactured from the metal-clad laminate 1 according to the present embodiment will be described. FIGS. 4A to 4C are cross-sectional views showing a schematic configuration of the wiring board 10 in the present embodiment. In the present embodiment, the wiring board 10 manufactured from the metal-clad laminate 1 shown in FIGS. 1A, 2B, and 2C will be described as an example. However, in the wiring board manufactured from the metal-clad laminate 1 in which the metal layer 3 (metal foil) is provided on the first surface 21 and / or the second surface 22 of the metal-clad laminate 1 and the resin film 2 shown in FIGS. 1B and 2A without the underlayer 4 (or bonding layer 5), it goes without saying that it has the same configuration as the wiring board manufactured from the metal-clad laminate 1 shown in FIG. 1A. Further, in the wiring board 10, the same components as those of the metal-clad laminate 1 according to the present embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0048] The wiring board 10 in the present embodiment includes a resin film 2 having a first surface 21 and a second surface 22 located on the opposite side of the first surface 21, and a wiring layer 6 including a first wiring layer 61 formed on the first surface 21 of the resin film 2 and a second wiring layer 62 formed on the second surface 22. The first wiring layer 61 and the second wiring layer 62 may be formed on the substantially flat first surface 21 and second surface 22, respectively (see FIGS. 4A and 4B), or may be embedded in the recesses 91 of the patterns 9 formed on the first surface 21 and the second surface 22 (see FIG. 4C). The wiring layer 6 (the first wiring layer 61 and the second wiring layer 62) may have a laminated structure in which a first layer 611, 621 based on the base layer 4 (the first base layer 41 and the second base layer 42) or the bonding layer 5 (the first bonding layer 51 and the second bonding layer 52) and a second layer 612, 622 based on the metal layer 3 (the first metal layer 31 and the second metal layer 32) are laminated in this order from the resin film 2 side (see FIGS. 4A and 4C), or a first layer 611, 621 based on the base layer 4 (the first base layer 41 and the second base layer 42) or the bonding layer 5 (the first bonding layer 51 and the second bonding layer 52), a second layer 612, 622 based on the metal layer 3 (the first metal layer 31 and the second metal layer 32), and a third layer 613, 623 based on the metal wiring layer 8 (the first metal wiring layer 81 and the second metal wiring layer 82, see FIG. 6A) may have a laminated structure laminated in this order from the resin film 2 side (see FIG. 4B). In the aspect shown in FIG. 4B, the material constituting the third layer 613, 623 (the metal wiring layer 8 (the first metal wiring layer 81 and the second metal wiring layer 82), see FIG. 6A) may be, for example, one or more selected from copper, iron, nickel, cobalt, molybdenum, tungsten, titanium, aluminum, etc., and may be the same material as the material constituting the first layer 611, 621 (the metal layer 3 (the first metal layer 31 and the second metal layer 32)), or may be a different material. The wiring board 10 in the present embodiment may be one on which one or more electronic components corresponding to the type of electronic device in which the wiring board 10 is used are mounted, may be a wiring board for a touch panel, or may be used as a planar heater.

[0049] In the case where the bonding layer 5 on which the first layers 611 and 621 in the wiring layer 6 (the first wiring layer 61 and the second wiring layer 62) are made of a material having electrical insulation, the first layers 611 and 612 may be continuous on the first surface 21 and the second surface 22 of the resin film 2. That is, the wiring board 10 of this embodiment includes the resin film 2, the bonding layer 5 located on the first surface 21 and the second surface 22 of the resin film 2, and the wiring layer 6 (the first wiring layer 61 and the second wiring layer 62) composed of the second layers 612 and 622 located on each bonding layer 5. A pattern 9 (protrusion 92) may or may not be located between the second layers 612 and 622 in the wiring layer 6 (the first wiring layer 61 and the second wiring layer 62). Further, the tops of the second layers 612 and 622 of the wiring layer 6 may be located on the same plane as the tops of the protrusions 92 of the pattern 9, or may be located closer to the resin film 2 side than the tops of the protrusions 92 of the pattern 9.

[0050] The width W of each wiring in the first wiring layer 61 61 and the width W of each wiring in the second wiring layer 62 62 are not particularly limited, but for example, they may be in the range of 0.1 μm to 1000 μm, and preferably in the range of 1 μm to 300 μm. Further, the pitch P 61 (the interval between adjacent wirings) of each wiring in the first wiring layer 61 and the pitch P 62 (the interval between adjacent wirings) of each wiring in the second wiring layer 62 are not particularly limited, but for example, they may be in the range of 0.2 μm to 5000 μm, and preferably in the range of 2 μm to 600 μm. Incidentally, the width W 61 and the pitch P 61 of each wiring in the first wiring layer 61, and the width W 62 and the pitch P 62 of each wiring in the second wiring layer 62 do not have to be uniform or constant within the respective planes of the first surface 21 and the second surface 22 of the resin film 2. For example, one wiring in the first wiring layer 61 may include different portions of its width W 61 , or one wiring in the second wiring layer 62 may include different portions of its width W 62It may include different portions. Also, the width W of one wiring of the first wiring layer 61 61 and the width W of other wirings 61 may be different from each other, and the width W of one wiring of the second wiring layer 62 62 and the width W of other wirings 62 may be different from each other. Also, the width W of the wirings of the first wiring layer 61 61 and the pitch P 61 and the width W of the wirings of the second wiring layer 62 62 and the pitch P 62 may be different from each other.

[0051] In the wiring board 10 shown in FIGS. 4A and 4B, the root mean square roughness (Rms) and the arithmetic mean roughness (Ra) of the first surface 21 of the resin film 2 exposed between the wirings of the first wiring layer 61 and the second surface 22 of the resin film 2 exposed between the wirings of the second wiring layer 62 may both be 50 nm or less, and preferably 0.5 nm to 10 nm. In the wiring board 10 shown in FIG. 4C, the root mean square roughness (Rms) and the arithmetic mean roughness (Ra) of the first surface 21 of the resin film 2 located directly below the pattern 9 and the second surface are similarly both preferably 50 nm or less, and preferably 0.5 nm to 10 nm. When both the root mean square roughness (Rms) and the arithmetic mean roughness (Ra) are 50 nm or less, particularly in the embodiment shown in FIG. 4C, since the pattern 9 is made of a transparent material (for example, a material having a light transmittance of 90% or more for visible light (light with a wavelength of 380 nm to 780 nm) and a haze (Hz) of 1.0 or less), the transparency of the wiring board 10 (transparency in the visible light region (wavelength 380 nm to 780 nm)) can be ensured. As will be described later, the wiring board 10 in the present embodiment is manufactured through an etching process or a chemical mechanical polishing process (CMP) of the metal layer 3 of the metal-clad laminate 1. The root mean square roughness (Rms) and the arithmetic mean roughness (Ra) of the first surface 21 and the second surface 22 of the resin film 2 in the metal-clad laminate 1 are both 50 nm or less. That is, it can be said that the root mean square roughness (Rms) and the arithmetic mean roughness (Ra) of the first surface 21 and the second surface 22 of the resin film 2 before etching the metal layer 3 of the metal-clad laminate 1 are 50 nm or less. Since the wiring board 10 in the present embodiment is manufactured by etching the metal layer 3 of the metal-clad laminate 1 or performing a chemical mechanical polishing process (CMP), in the metal-clad laminate 1, it can be said that the root mean square roughness (Rms) and the arithmetic mean roughness (Ra) of the first surface 21 and the second surface 22 of the resin film 2 exposed after removing the metal layer 3 by etching or a chemical mechanical polishing process (CMP) are both 50 nm or less.

[0052] The haze (Hz) of the wiring board 10 in the present embodiment may be 1.0 or less, preferably 0.7 or less, and more preferably 0.1 to 0.5. By the haze (Hz) of the wiring board 10 being 1.0 or less, the transparency of the wiring board 10 (transparency in the visible light region (wavelength 380 nm to 780 nm)) can be ensured. Therefore, the wiring board 10 in the present embodiment is suitable as a device that requires transparency, such as a touch panel or a planar heater.

[0053] An example of the manufacturing method of the wiring board 10 in the present embodiment will be described. FIGS. 5A to 5C are cross-sectional views showing the respective steps of the manufacturing method of the wiring board in the present embodiment.

[0054] First, the metal-clad laminate 1 (see FIGS. 1A and 1B) according to the present embodiment is prepared, and a resist layer 70 that covers the metal layers 3 (the first metal layer 31 and the second metal layer 32) of the metal-clad laminate 1 is formed (see FIG. 5A).

[0055] The resist material constituting the resist layer 70 is not particularly limited, and for example, a negative-type or positive-type photosensitive material or the like can be used, but it is preferable to use a negative-type photosensitive material. The wiring layer is formed by etching the metal layers 3 (the first metal layer 31 and the second metal layer 32) through the mask pattern 71 formed by patterning the resist layer 70. Therefore, the film thickness of the resist layer 70 can be appropriately set according to the etching selectivity ratio or the like corresponding to the constituent materials of the metal layers 3 (the first metal layer 31 and the second metal layer 32).

[0056] The method for forming the resist layer 70 is not particularly limited, and a conventionally known coating film forming method may be adopted. For example, a method of applying the resist material constituting the resist layer 70 onto the metal layers 3 (the first metal layer 31 and the second metal layer 32) by a die coating method, a spin coating method, or the like can be mentioned. Further, a method of laminating and forming a dry film resist made of the above resist material onto the metal layers 3 (the first metal layer 31 and the second metal layer 32) using a laminator or the like may also be used.

[0057] Next, a mask pattern 71 corresponding to the first wiring layer 61 and the second wiring layer 62 is formed by patterning the resist layer 70 (see FIG. 5B). As a method for patterning the resist layer 70, for example, a photolithography method by exposure and development through a photomask corresponding to the mask pattern 71, an imprint lithography method using an imprint mold having an uneven structure corresponding to the mask pattern 71, or the like may be used. Instead of forming and patterning the resist layer 70, the mask pattern 71 corresponding to the first wiring layer 61 and the second wiring layer 62 may be formed on the metal layer 3 (the first metal layer 31 and the second metal layer 32) by printing the above resist material.

[0058] Then, the first wiring layer 61 is formed on the first surface 21 of the resin film 2 and the second wiring layer 62 is formed on the second surface 22 by etching (wet etching or dry etching) the metal layer 3 (the first metal layer 31 and the second metal layer 32) and the underlying layer 4 (the first underlying layer 41 and the second underlying layer 42) or the bonding layer 5 (the first bonding layer 51 and the second bonding layer 52) through the mask pattern 71 (see FIG. 5C). The etching solution for wet etching the metal layer 3 and the underlying layer 4 or the bonding layer 5 may be appropriately selected according to the constituent materials of the metal layer 3 and the underlying layer 4 or the bonding layer 5. In this way, the wiring board 10 (see FIG. 4A) in the present embodiment can be manufactured.

[0059] Another example of the manufacturing method of the wiring board 10 in the present embodiment will be described. FIGS. 6A to 6C are cross-sectional views showing the steps of another aspect of the manufacturing method of the wiring board 10 in the present embodiment.

[0060] First, prepare a metal-clad laminate 1 (see FIGS. 1A and 1B) according to this embodiment, and form a resist layer 70 that covers the metal layers 3 (the first metal layer 31 and the second metal layer 32) of the metal-clad laminate 1 (see FIG. 5A). Then, by patterning the resist layer 70, a resist pattern 71 is formed on the metal layers 3 (the first metal layer 31 and the second metal layer 32) (see FIG. 5B). As will be described later, since the third layers 613 and 623 formed in the recesses (openings) of the resist pattern 71 constitute part of the wiring layers 6 (the first wiring layer 61 and the second wiring layer 62), the dimensions (for example, the width in the short side direction of the recesses (openings), etc.) and the planar shape (for example, line-and-space shape, key shape, etc.) of the recesses (openings) of the resist pattern 71 may be appropriately set according to the wiring rules required for the wiring substrate 10 to be manufactured.

[0061] Next, a metal wiring layer 8 (the first metal wiring layer 81 and the second metal wiring layer 82) is formed so as to fill the recesses (openings) of the resist pattern 71 (see FIG. 6A). The metal wiring layer 8 (the first metal wiring layer 81 and the second metal wiring layer 82) can be formed, for example, by electroless plating treatment using the materials constituting them.

[0062] Subsequently, by removing the resist pattern 71, third layers 613 and 623 that constitute part of the wiring layers 6 (the first wiring layer 61 and the second wiring layer 62) are formed on the metal layers 3 (the first metal layer 31 and the second metal layer 32) (see FIG. 6B). Thereafter, by etching the metal layers 3 (the first metal layer 31 and the second metal layer 32) and the base layers 4 (the first base layer 41 and the second base layer 42) or the bonding layers 5 (the first bonding layer 51 and the second bonding layer 52), wiring layers 6 (the first wiring layer 61 and the second wiring layer 62) having a laminated structure in which the first layers 611 and 621, the second layers 612 and 622, and the third layers 613 and 623 are laminated in this order are formed from the resin film 2 side (see FIG. 6C). In this way, the wiring substrate 10 (see FIG. 4B) in this embodiment can be manufactured.

[0063] Another example of the manufacturing method of the wiring board 10 in the present embodiment will be described. FIGS. 7A to 7C are cross-sectional views showing the respective steps of another aspect of the manufacturing method of the wiring board 10 in the present embodiment.

[0064] Prepare the metal-clad laminate 1 (see FIG. 2B) according to the present embodiment (see FIG. 7A), and perform chemical mechanical polishing (CMP) on the metal layers 3 (the first metal layer 31 and the second metal layer 32) of the metal-clad laminate 1 to expose the top of the convex portion 92 of the pattern 9 (see FIG. 7B). As a result, the second layers 612 and 622 embedded in the concave portions 91 of the pattern 9 formed on the first surface 21 and the second surface 22 of the resin film 2 are formed.

[0065] Next, remove the pattern 9 (convex portion 92), and remove the underlying layer 4 (or bonding layer 5) exposed by the removal of the pattern 9 (convex portion 92) by etching (wet etching or dry etching) (see FIG. 7C). As a result, the first layers 611 and 621 are formed on the resin film 2 side of the second layers 612 and 622, and a wiring layer 6 (the first wiring layer 61 and the second wiring layer 62) in which the first layers 611 and 621 and the second layers 612 and 622 are laminated in order from the resin film 2 side is formed. In this way, the wiring board 10 (see FIG. 4A) in the present embodiment can be manufactured. Note that when the pattern 9 (convex portion 92) in the metal-clad laminate 1 is made of a transparent material, the haze is 1.0 or less, and the bonding layer 5 is made of a material having electrical insulation, after exposing the top of the convex portion 92 of the pattern 9 (see FIG. 7B), the wiring board 10 including the pattern 9 may be manufactured without removing the pattern 9.

[0066] Another example of the manufacturing method of the wiring board 10 in the present embodiment will be described. FIGS. 8A and 8B are cross-sectional views showing the respective steps of another aspect of the manufacturing method of the wiring board 10 in the present embodiment.

[0067] Prepare a metal-clad laminate 1 (see FIG. 2C) according to this embodiment (see FIG. 8A), and perform a chemical mechanical polishing process (CMP) on the metal layers 3 (the first metal layer 31 and the second metal layer 32) of the metal-clad laminate 1 so as to expose the tops of the convex portions 92 of the pattern 9 (see FIG. 8B). Thereby, wiring layers 6 (a first wiring layer 61 and a second wiring layer 62) embedded in the concave portions 91 of the pattern 9 formed on the first surface 21 and the second surface 22 of the resin film 2 are formed. In this way, a wiring board 10 (see FIG. 4C) in this embodiment can be manufactured. Note that, by removing the pattern 9 from the wiring board 10 (see FIG. 4C) manufactured in this way, a wiring board 10 having the configuration shown in FIG. 4A may be manufactured.

[0068] According to the manufacturing method of the wiring board 10 in this embodiment, since the 180° peel strength between the resin film 2 and the metal layer 3 in the metal-clad laminate 1 is 0.6 N / mm or more, it can be said that sufficient adhesion required during the patterning of the metal layer 3 is obtained. Therefore, the wiring layers 6 (the first wiring layer 61 and the second wiring layer 62) can be formed with high accuracy. Further, both the root mean square roughness (Rms) and the arithmetic mean roughness (Ra) of the first surface 21 and the second surface 22 (metal layer laminated surfaces) of the resin film 2 exposed after etching the metal layer 3 and the underlying layer 4 or the bonding layer 5 are 50 nm or less, and the haze of the resin film 2 after etching the metal layer 3 and the underlying layer 4 or the bonding layer 5 is 1.0 or less. Thus, the transparency of the wiring board 10 (transparency in the visible light region (wavelength 380 nm to 780 nm)) can be ensured.

[0069] The embodiments described above are described to facilitate the understanding of the present invention, and are not described to limit the present invention. Therefore, each element disclosed in the above embodiments is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

Example

[0070] Hereinafter, the present invention will be described in more detail with reference to examples and the like, but the present invention is not limited to the following examples and the like.

[0071] [Test Example 1] As the resin film 2, a cycloolefin polymer film (manufactured by Nippon Zeon Co., Ltd., Zeonoar Film ZF16-100) was prepared. After both surfaces of the cycloolefin polymer film were plasma-cleaned (plasma-treated), an IZO thin film with a thickness of 15 nm was formed on both surfaces of the cycloolefin polymer film by sputtering. Next, a copper thin film with a thickness of 200 nm was formed on the IZO thin film by sputtering. Subsequently, an electrolytic plating treatment was performed to form an electrolytic copper plating layer with a thickness of 12 μm on the copper thin film, thereby producing a metal-clad laminate 1 (Sample 1) having a metal layer 3 composed of the copper thin film and the electrolytic copper plating layer.

[0072] Regarding the metal-clad laminate 1 produced as described above, the 180° peel strength was measured as follows. First, a test piece with a 10-mm-wide cut formed in the copper layer on one surface side of the resin film 2 of the metal-clad laminate 1 was prepared, and in accordance with JIS-K-6854, a 180° peel test was performed on the test piece using a load-displacement measurement unit (manufactured by IMADA Co., Ltd., FSA-1KE-50N) to measure the 180° peel strength. The results are shown in Table 1.

[0073] The electrolytic copper plating layer, the copper thin film, and the IZO thin film of the metal-clad laminate 1 produced as described above were etched using a copper etching solution (manufactured by Meltex Co., Ltd., Melstrip Cu-3931). The total light transmittance and haze (Hz) of the resin film 2 after the electrolytic copper plating layer, the copper thin film, and the IZO thin film were etched were measured using a haze meter (manufactured by Murakami Color Technology Research Institute, HM-150). The results are shown in Table 1.

[0074] In addition, the root mean square roughness (Rms) and arithmetic mean roughness (Ra) of the surface of the resin film 2 after the electrolytic copper plating layer, the copper thin film, and the IZO thin film were etched were measured using a non-contact three-dimensional surface shape measuring machine (manufactured by Zygo Corporation, NV6300 MICROSCOPE). The results are shown in Table 1.

[0075] [Test Example 2] As the resin film 2, a cycloolefin polymer film (manufactured by Nippon Zeon Co., Ltd., Zeonoa Film ZF16-100) was prepared, and the cycloolefin polymer film was immersed in an aqueous solution of a triazine thiol compound. Next, after performing a Pd catalyst addition treatment (catalyzing treatment) on the triazine thiol compound thin film formed on both surfaces of the cycloolefin polymer film by immersion in the aqueous solution of the triazine thiol compound, a copper thin film (film thickness: 200 nm) was formed on the triazine thiol compound thin film by electroless copper plating treatment. Subsequently, an electrolytic plating treatment was performed to form an electrolytic copper plating layer with a film thickness of 12 μm on the copper thin film, thereby producing a metal-clad laminate 1 (Sample 2). The 180° peel strength of the metal-clad laminate 1 thus produced was measured in the same manner as in Test Example 1, and after etching the electrolytic copper plating layer, copper thin film, and triazine thiol compound thin film of the metal-clad laminate 1, the total light transmittance and haze (Hz) of the resin film 2, as well as the root mean square roughness (Rms) and arithmetic mean roughness (Ra) of the surface of the resin film 2 were measured in the same manner as in Example 1. The results are shown in Table 1.

[0076] [Test Example 3] A metal-clad laminate (Sample 3) was produced in the same manner as in Test Example 1, except that a NiCr alloy thin film with a film thickness of 4 nm was formed by sputtering instead of the IZO thin film. The 180° peel strength of the metal-clad laminate, the total light transmittance and haze (Hz) of the resin film after etching the electrolytic copper plating layer, copper thin film, and NiCr alloy thin film of the metal-clad laminate, and the root mean square roughness (Rms) and arithmetic mean roughness (Ra) of the surface of the resin film were measured. The results are shown in Table 1.

[0077] [Test Example 4] A metal-clad laminate (Sample 4) was produced in the same manner as in Test Example 3, except that the film thickness of the NiCr alloy thin film was changed to 12 nm. The 180° peel strength of the metal-clad laminate, the total light transmittance and haze (Hz) of the resin film after etching the electrolytic copper plating layer, copper thin film, and NiCr alloy thin film of the metal-clad laminate, and the root mean square roughness (Rms) and arithmetic mean roughness (Ra) of the surface of the resin film were measured. The results are shown in Table 1.

[0078] [Test Example 5] A cycloolefin polymer film (manufactured by Nippon Zeon Co., Ltd., Zeonoa Film ZF16-100) was prepared as the resin film. After the surface of the resin film was plasma-cleaned, a copper foil (manufactured by Fukuda Metal Foil & Powder Co., Ltd., ultra-low roughness non-roughening treated electrolytic copper foil CF-T9DA-SV) was laminated onto the surface of the resin film by hot pressing at 220 °C to produce a metal-clad laminate (Sample 5). The 180° peel strength of the metal-clad laminate, the total light transmittance and haze (Hz) of the resin film after etching the copper foil, and the root mean square roughness (Rms) and arithmetic mean roughness (Ra) of the surface of the resin film were measured in the same manner as in Test Example 1. The results are shown in Table 1.

[0079] [Test Example 6] A cycloolefin polymer film (manufactured by Nippon Zeon Co., Ltd., Zeonoa Film ZF16-100) was prepared as the resin film, and a polyester-based primer was coated thereon with a film thickness of 100 nm by a wet coating method. After the drying of the primer layer, a copper vapor deposition film with a film thickness of 200 nm was formed on the primer layer. Subsequently, an electrolytic plating treatment was performed to form an electrolytic copper plating layer with a film thickness of 12 μm on the copper vapor deposition film, thereby producing a metal-clad laminate (Sample 6). The 180° peel strength of the metal-clad laminate, the total light transmittance and haze (Hz) of the resin film after etching the electrolytic copper plating layer and the copper vapor deposition film, and the root mean square roughness (Rms) and arithmetic mean roughness (Ra) of the surface of the resin film were measured in the same manner as in Test Example 1. The results are shown in Table 1.

[0080] [Test Example 7] As a resin film, a cycloolefin polymer film (manufactured by Nippon Zeon Co., Ltd., Zeonoa Film ZF16-100) was prepared. After the surface of the resin film was plasma-cleaned, a triazine thiol-based compound was coated and dried to a film thickness of 10 nm. Then, a copper foil (manufactured by Fukuda Metal Foil & Powder Co., Ltd., ultra-low roughness non-roughened electrolytic copper foil CF-T9DA-SV) was laminated onto the resin film at a temperature of 150 °C, a pressure of 4 MPa, and a time of 10 minutes by vacuum hot pressing to produce a metal-clad laminate (Sample 7). The 180° peel strength of the metal-clad laminate 1, the total light transmittance and haze (Hz) of the resin film after etching the copper foil, and the root mean square roughness (Rms) and arithmetic mean roughness (Ra) of the surface of the resin film were measured in the same manner as in Test Example 1. The results are shown in Table 1.

[0081]

Table 1

[0082] As is clear from the results shown in Table 1, in the metal-clad laminates 1 (Sample 1, Sample 2) of Test Example 1 and Test Example 2, the 180° peel strength was 0.6 N / mm or more, and the adhesion between the resin film 2 and the metal layer 3 was excellent. On the other hand, in Test Example 3 and Test Example 4 (Sample 3, Sample 4) using an NiCr thin film as the underlayer, although excellent results were obtained for the total light transmittance and haze, which are indices of transparency, and the root mean square roughness Rms and arithmetic mean roughness Ra, which are indices of surface roughness, the 180° peel strength was insufficient. Also, in Test Example 6 (Sample 6) in which the resin film and the metal layer were adhered using a polyester-based primer, although an excellent 180° peel strength was shown, the haze (Hz) was as high as 1.4, and it is considered that the high-frequency characteristics are inferior by providing an adhesive layer composed of an adhesive between the resin film and the metal layer. Furthermore tree in Test Example 7 (Sample 7) in which a metal layer was formed on the surface of the resin film, although a good 180° peel strength was shown, inferior results were obtained in terms of the root mean square roughness (Rms) and arithmetic mean roughness (Ra) of the resin film after removing the metal layer.

[0083] In addition, when a wiring substrate is manufactured from a metal-clad laminate using an NiCr thin film as the base layer and a copper layer as the metal layer as in Test Example 3 and Test Example 4 (Sample 3, Sample 4), when etching the NiCr thin film, the wiring layer formed by etching the copper layer may also be etched, and there is a risk that the accuracy of the dimensions (e.g., width) and shape (cross-sectional shape) of the wiring layer will deteriorate. Furthermore, the wiring layer will contain Ni, which is a magnetic material, and as a result, there is also a risk of an increase in transmission loss due to the skin effect. In this regard, by manufacturing a wiring substrate from a metal-clad laminate 1 having an IZO thin film as the base layer 4, a triazine thiol-based compound thin film as the bonding layer 5, and a copper layer as the metal layer 3 as in Test Example 1 and Test Example 2 (Sample 1, Sample 2), it is possible to suppress a decrease in the accuracy of the dimensions (e.g., width) and shape (cross-sectional shape) of the wiring layer and an increase in transmission loss.

Explanation of symbols

[0084] 1... Metal-clad laminate 2... Resin film 21... First surface 22... Second surface 3... Metal layer 31... First metal layer 32... Second metal layer 4... Base layer 41... First base layer 42... Second base layer 5... Bonding layer 51... First bonding layer 52... Second bonding layer 6... Wiring layer 61... First wiring layer 62... Second wiring layer 9... Pattern 91... Recessed portion 92... Protruding portion 10... Wiring substrate

Claims

1. A metal-clad laminate comprising a resin film and a metal layer laminated without an adhesive on at least one surface of the resin film, which is a metal layer lamination surface, wherein the adhesive is composed of a resin-based primer, and includes an underlayer composed of an indium zinc oxide (IZO) thin film or a bonding layer composed of a triazine thiol-based compound, formed between the metal layer and the metal layer lamination surface, wherein the 180° peel strength between the metal layer and the resin film is 1.0 N / mm or more, and the resin film is a cycloolefin polymer film or a cycloolefin copolymer substrate.

2. The metal-clad laminate according to claim 1, wherein both the root mean square roughness (Rms) and the arithmetic mean roughness (Ra) of the metal layer lamination surface exposed after removing the metal layer are 50 nm or less.

3. wherein both surfaces of the resin film are the metal layer lamination surfaces, and the metal layer is laminated on the underlayer or the bonding layer located on each of the two metal layer lamination surfaces.

4. wherein a pattern having recesses and protrusions is formed on the metal layer lamination surface of the resin film, and the metal layer is laminated so as to fill the recesses and cover the metal layer lamination surface.

5. A wiring board comprising a resin film and a wiring layer provided without an adhesive on at least one surface of the resin film, which is a metal layer lamination surface, wherein the adhesive is composed of a resin-based primer, and the wiring layer includes a first layer located on the metal layer lamination surface and a second layer located on the first layer. The first layer is composed of an indium zinc oxide (IZO) thin film or a triazine thiol-based compound. The second layer consists of an electroless metal plating layer or a sputtered metal layer located on the first layer, and an electrolytic metal plating layer located on the electroless metal plating layer or the sputtered metal layer. The 180° peel strength between the wiring layer and the resin film is 1.0 N / mm or more. The resin film is a cycloolefin polymer film or a cycloolefin copolymer substrate, and the wiring substrate.

6. The wiring substrate according to claim 5, wherein the wiring layer has a third layer made of an electroless metal plating layer located on the electrolytic metal plating layer of the second layer.

7. A method for manufacturing a metal-clad laminate in which a metal layer is formed on at least one surface of a resin film, which is a metal layer laminated surface, without an adhesive in between, The adhesive is composed of a resin-based primer. A step of forming an underlayer composed of an indium zinc oxide (IZO) thin film or a bonding layer composed of a triazine thiol-based compound on the metal layer laminated surface of the resin film; And a step of forming the metal layer on the underlayer or the bonding layer, The step of forming the metal layer includes a step of forming an electroless metal plating layer or a sputtered metal layer on the underlayer or the bonding layer, and a step of forming an electrolytic metal plating layer on the electroless metal plating layer or the sputtered metal layer. Both the root mean square roughness (Rms) and the arithmetic mean roughness (Ra) of the metal layer laminated surface of the resin film are 50 nm or less. The 180° peel strength between the metal layer and the resin film is 1.0 N / mm or more. A method for manufacturing a metal-clad laminate, wherein the resin film is a cycloolefin polymer film or a cycloolefin copolymer substrate.

8. The manufacturing method of the metal-clad laminate according to claim 7, wherein both the root mean square roughness (Rms) and the arithmetic mean roughness (Ra) of the metal layer laminated surface of the resin film after removing the metal layer from the metal-clad laminate are 50 nm or less.

9. Both surfaces of the resin film are the metal layer laminated surfaces, In the step of forming the metal layer, the metal layer is formed on each of the two metal layer laminated surfaces without using the adhesive, according to the manufacturing method of the metal-clad laminate described in claim 7 or 8.

10. A pattern having concave portions and convex portions is formed on the metal layer laminated surface of the resin film, In the step of forming the metal layer, the metal layer is formed so as to fill the concave portions and cover the convex portions of the pattern, according to the manufacturing method of the metal-clad laminate described in any one of claims 7 to 9.

11. A manufacturing method of a wiring board including a step of forming a wiring layer by etching the metal layer of the metal-clad laminate manufactured by the manufacturing method of the metal-clad laminate described in any one of claims 7 to 9.

12. The manufacturing method of the wiring board according to claim 11, wherein both the root mean square roughness (RMS) and the arithmetic mean roughness (Ra) of the resin film exposed after etching the metal layer are 50 nm or less.

13. The manufacturing method of the wiring board according to claim 11 or 12, wherein the haze of the resin film exposed after etching the metal layer is 0.1 to 0.

5.

14. A manufacturing method of a wiring board including a step of forming a wiring layer by chemically mechanically polishing the metal layer so as to expose the tops of the convex portions of the pattern of the metal-clad laminate manufactured by the manufacturing method of the metal-clad laminate described in claim 10.

15. A step of forming a resist pattern having an opening on the metal layer of the metal-clad laminate manufactured by the method for manufacturing a metal-clad laminate according to any one of claims 7 to 9; A step of forming a metal wiring layer in the opening of the resist pattern; A step of removing the resist pattern; A step of etching the metal layer exposed by the removal of the resist pattern; A method for manufacturing a wiring board, comprising:

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