Copper member

Abstract

A copper member, comprising a copper material and a protrusion formed on the surface of the copper material. The protrusion contains copper and / or a copper oxide. When the copper member is measured using a nanoindenter under a prescribed measurement condition, the copper member satisfies at least one of (1) indentation creep (CIT) of 80% or greater, (2) indentation hardness (GPa) of 1 or less, and (3) an indentation elastic modulus (GPa) of 120 or less. The copper member is excellent in adhesion to a resin base material and heat-resistance reliability.

Description

Copper materials

[0001] The present invention relates to copper components.

[0002] Copper members used as materials for printed wiring boards and lithium-ion batteries are required to have high adhesion to the resin substrate as a support from the viewpoint of quality and reliability. Furthermore, because peeling can occur due to the difference in thermal shrinkage rate between the copper member and the resin substrate when heat is applied, the copper member is also required to be resistant to peeling from the resin substrate when heated (high heat resistance reliability).

[0003] For printed wiring boards, a curable composition having low thermal expansion, heat resistance (high glass transition temperature), and high peel strength (adhesion to copper members) has been disclosed for the purpose of suppressing peeling between copper members and resin substrates (Patent Document 1).For lithium-ion batteries, a copper member having mechanical strength (tensile strength) and surface hardness has been disclosed for the purpose of preventing wrinkles and deformation during press processing and charge / discharge, and maintaining adhesion between negative electrode active materials and copper members (Patent Document 2).

[0004] International Publication No. 2023 / 013712 International Publication No. 2014 / 112619

[0005] However, Patent Document 1 only examines the curable composition, and the disclosed curable composition does not provide an anchoring effect when the copper member has a small roughness, and the adhesion of these laminates is not high, probably because stress is concentrated near the interface between the copper member and the cured product of the composition. Moreover, the copper member of Patent Document 2 also cannot be said to be sufficient from the viewpoint of heat resistance reliability.

[0006] SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a copper member having excellent adhesion to a resin substrate and excellent heat resistance reliability.

[0007] As a result of extensive research into achieving the above object, the inventors have found that a copper member having a specific structure can solve the above problems. The present invention was completed based on these findings.

[0008] That is, the present invention provides a copper member comprising a copper material and protrusions formed on the surface of the copper material, wherein the protrusions contain copper and / or copper oxide, and satisfy at least one selected from the group consisting of the following (1) to (3): (1) Using a nanoindenter, an indenter is pressed into the surface of the copper member at a load of 0.1 mN / s in an atmosphere of 30°C. The load is released when the indentation depth reaches 10 nm. The distance the indenter has pressed 5 seconds after the load is released is defined as h (nm). The indentation creep (C) of the copper member is calculated by [(h-10) / 10] x 100. ＩＴ ) is 80% or more. The reference point for depth was the surface of the copper member. (2) Using a nanoindenter, the indenter is pressed into the surface of the copper member in an atmosphere of 30°C, applying a load at a pressing rate of 0.1 mN / s. The load is released when the indentation depth reaches 10 nm. The indentation hardness (GPa) of the copper member, calculated using an analytical method in accordance with ISO 14577-1 from the graph of applied load and indentation depth (displacement) obtained by the above operation, is 1 or less. The maximum indentation depth (hmax) used to calculate the indentation hardness (GPa) was obtained when fitting the unloading curve at F = 20% and 95%. The reference point for depth was the surface of the copper member. (3) Using a nanoindenter, the indenter is pressed into the surface of the copper member in an atmosphere of 30°C, applying a load at a pressing rate of 0.1 mN / s. The load is released when the indentation depth reaches 10 nm. From the graph of applied load and indentation depth (displacement) obtained by the above operation, the indentation modulus (GPa) of the copper member calculated by an analytical method in accordance with ISO 14577-1 was 120 or less. The maximum indentation depth (hmax) used to calculate the indentation modulus (GPa) was that obtained when fitting the unloading curve at F = 20% and 95%. The reference point for the depth was the surface of the copper member.

[0009] The copper member preferably has a copper oxide layer formed on the surface thereof.

[0010] The copper member preferably has a metal layer other than copper formed on a part or all of the surface of the copper oxide layer.

[0011] In the copper member, the metal layer preferably contains a magnetic metal and a non-magnetic metal other than copper.

[0012] The copper member of the present invention has excellent adhesion to resin substrates and heat resistance reliability.

[0013] 1 is a schematic cross-sectional view showing an embodiment of a copper member of the present invention, and FIG. 2 is a schematic cross-sectional view showing an embodiment of a laminate of a copper member and a resin base material of the present invention.

[0014] [Copper Member] The copper member of the present invention is a copper member comprising a copper material and protrusions formed on the surface of the copper material, wherein the protrusions contain copper and / or copper oxide, and is characterized in that at least one selected from the group consisting of the following (1) to (3) is satisfied: (1) Using a nanoindenter, an indenter is pressed into the surface of the copper member in an atmosphere of 30°C, applying a load at a pressing rate of 0.1 mN / s. The load is released when the pressing depth reaches 10 nm. The distance pressed by the indenter 5 seconds after the load is released is defined as h (nm). The indentation creep (C) of the copper member, calculated by [(h-10) / 10] x 100, is ＩＴ) is 80% or more. The reference point for depth was the surface of the copper member. (2) Using a nanoindenter, the indenter is pressed into the surface of the copper member in an atmosphere of 30°C, applying a load at a pressing rate of 0.1 mN / s. The load is released when the indentation depth reaches 10 nm. The indentation hardness (GPa) of the copper member, calculated using an analytical method in accordance with ISO 14577-1 from the graph of applied load and indentation depth (displacement) obtained by the above operation, is 1 or less. The maximum indentation depth (hmax) used to calculate the indentation hardness (GPa) was obtained when fitting the unloading curve at F = 20% and 95%. The reference point for depth was the surface of the copper member. (3) Using a nanoindenter, the indenter is pressed into the surface of the copper member in an atmosphere of 30°C, applying a load at a pressing rate of 0.1 mN / s. The load is released when the indentation depth reaches 10 nm. From the graph of applied load and indentation depth (displacement) obtained by the above operation, the indentation modulus (GPa) of the copper member calculated using an analytical method in accordance with ISO 14577-1 was 120 or less. The maximum indentation depth (hmax) used to calculate the indentation modulus (GPa) was that obtained when fitting the unloading curve at F = 20% and 95%. The reference point for the depth was the surface of the copper member. This allows the copper member of the present invention to exhibit high adhesion to resin substrates and heat resistance reliability.

[0015] The copper material may have a copper oxide layer formed on its surface. When a copper oxide layer is formed on the surface of the copper material, the protrusions are formed on the surface of the copper material as part of the copper oxide layer. That is, the protrusions contain copper oxide and are formed on the surface of the copper oxide layer.

[0016] The protrusions may be formed on a part or all of the surface of the copper material. Furthermore, when a copper oxide layer is formed on the surface of the copper material, the protrusions may be formed on a part or all of the surface of the copper oxide layer.

[0017] In the copper member of the present invention, a metal layer other than copper may be formed on part or all of the surface of the copper material so as to cover the protrusions. When a copper oxide layer is formed on the surface of the copper material, a metal layer other than copper may be formed so as to cover part or all of the surface of the copper oxide layer. Furthermore, a silicon compound layer may be formed on part or all of the surface of the copper material, the copper oxide layer, and the metal layer.

[0018] In the above copper member, the surface Ra (arithmetic mean roughness) is not particularly limited, but is, for example, 0.40 μm or less, 0.30 μm or less, 0.20 μm or less, or 0.10 μm or less. It is also, for example, 0.01 μm or more, 0.02 μm or more, or 0.03 μm or more. Ra represents the average of the absolute values ​​of the peak height Zp and valley depth Zv of the profile curve (y = Z(x)) over the reference length 1. Ra can be calculated, for example, by the method specified in JIS B 0601:2013. Specifically, Ra can be calculated by the method described in the examples below.

[0019] In the above copper member, the surface Rz (maximum height roughness) is not particularly limited, but is, for example, 1.50 μm or less, 1.20 μm or less, 1.00 μm or less, 0.90 μm or less, 0.80 μm or less, 0.60 μm or less, 0.50 μm or less, 0.45 μm or less, or 0.40 μm or less. It is also, for example, 0.10 μm or more, 0.15 μm or more, 0.20 μm or more, 0.30 μm or more, 0.33 μm or more, or 0.34 μm or more. Rz represents the sum of the maximum peak height Zp and the maximum valley depth Zv of the profile curve (y = Z(x)) over the reference length 1. Rz can be calculated, for example, by the method specified in JIS B 0601:2013. Specifically, Rz can be calculated by the method described in the examples below.

[0020] In the copper member, the indentation creep (C ＩＴ) is, for example, 80% or more, 90% or more, 100% or more, 105% or more, 110% or more, 120% or more, or 130% or more. Also, for example, it is 300% or less, 280% or less, 250% or less, 230% or less, 220% or less, 210% or less, 200% or less, 195% or less, 190% or less, 180% or less, or 175% or less. ＩＴ When the indentation creep (C) is within the above range, the adhesiveness to the resin substrate and the heat resistance reliability tend to be excellent. ＩＴ ) can be specifically measured by the method described in the Examples below.

[0021] The copper member has a maximum indentation depth of, for example, 18 nm or more, 19 nm or more, or 20 nm or more in an atmosphere of 30° C. and a preset indentation depth of 10 nm. The maximum indentation depth is, for example, 40 nm or less, 36 nm or less, 34 nm or less, 32 nm or less, or 30 nm or less. Having the maximum indentation depth within the above ranges tends to result in excellent adhesion to resin substrates and excellent heat resistance reliability.

[0022] In the above copper member, the indentation hardness (GPa) at a temperature of 30°C and a set indentation depth of 10 nm as described in (2) is, for example, 1 or less, 0.98 or less, 0.96 or less, 0.95 or less, 0.94 or less, 0.93 or less, 0.92 or less, 0.8 or less, 0.6 or less, 0.5 or less, 0.4 or less, 0.3 or less, or 0.25 or less. Also, for example, it is preferably 0.01 or more, 0.03 or more, 0.05 or more, 0.08 or more, 0.1 or more, 0.12 or more, 0.15 or more, or 0.18 or more. Also, the indentation hardness (GPa) at a temperature of 30°C and a set indentation depth of 100 nm is, for example, preferably 1.28 or less, 1.25 or less, 1.22 or less, 1.2 or less, 1.1 or less, 1.0 or less, or 0.9 or less. Preferably, the hardness is, for example, 0.01 or more, 0.1 or more, 0.15 or more, 0.2 or more, 0.25 or more, 0.3 or more, 0.4 or more, 0.5 or more, 0.6 or more, or 0.7 or more. The indentation hardness (GPa) in an atmosphere of 30°C and at a set indentation depth of 200 nm is, for example, 1.48 or less, 1.46 or less, 1.44 or less, 1.42 or less, 1.4 or less, 1.3 or less, 1.2 or less, or 1.15 or less. Preferably, the hardness is, for example, 0.1 or more, 0.15 or more, 0.2 or more, 0.25 or more, 0.3 or more, 0.35 or more, 0.4 or more, 0.6 or more, 0.8 or more, 0.9 or more, or 1.0 or more. Furthermore, the indentation hardness (GPa) in an atmosphere of 30 ° C. and a set indentation depth of 500 nm is preferably, for example, 1.42 or less, 1.4 or less, 1.3 or less, 1.2 or less, or 1.15 or less. Furthermore, for example, it is preferably 0.1 or more, 0.2 or more, 0.3 or more, 0.4 or more, 0.5 or more, 0.6 or more, 0.8 or more, 0.9 or more, 1.0 or more, or 1.08 or more. When the indentation hardness is within the above range, adhesion to the resin substrate and heat resistance reliability tend to be excellent. The indentation hardness can be specifically measured by the method described in the examples below.

[0023] In the copper member, the indentation modulus (GPa) at a temperature of 30°C and a set indentation depth of 10 nm, as described in (3), is preferably, for example, 120 or less, 115 or less, 110 or less, 108 or less, 106 or less, 100 or less, 80 or less, 60 or less, 50 or less, or 45 or less. It is also preferably, for example, 3 or more, 6 or more, 9 or more, 12 or more, 14 or more, 15 or more, 20 or more, 25 or more, 30 or more, or 35 or more. It is also preferably, for example, 145 or less, 140 or less, 135 or less, 130 or less, 125 or less, 120 or less, 115 or less, 110 or less, 100 or less, 90 or less, 80 or less, or 70 or less. Preferably, the indentation modulus is, for example, 3 or more, 6 or more, 9 or more, 10 or more, 12 or more, 15 or more, 20 or more, 30 or more, 40 or more, 50 or more, or 60 or more. The indentation modulus (GPa) in an atmosphere at 30°C and at a set indentation depth of 200 nm is, for example, 150 or less, 145 or less, 140 or less, 135 or less, 130 or less, 125 or less, 120 or less, 110 or less, or 100 or less. The indentation modulus is, for example, 6 or more, 9 or more, 10 or more, 12 or more, 15 or more, 20 or more, 30 or more, 50 or more, 60 or more, 70 or more, 80 or more, or 90 or more. The indentation modulus (GPa) in an atmosphere at 30°C and at a set indentation depth of 500 nm is, for example, 113 or less, 110 or less, 10 or less, 10 or less, or 100 or less. Further, for example, it is preferably 20 or more, 30 or more, 40 or more, 45 or more, 50 or more, 60 or more, 70 or more, 80 or more, or 85 or more. When the indentation modulus is within the above range, adhesion to the resin substrate and heat resistance reliability tend to be excellent. Specifically, the indentation modulus can be measured by the method described in the examples below.

[0024] (Copper Material) A copper material refers to a material whose surface is partially or entirely made of copper. The material inside the copper material (inside the copper present on the surface) may be copper or a material other than copper (for example, a metal other than copper, a resin substrate, etc.), but is preferably copper. In other words, the copper material is preferably a material whose entirety is made of copper.

[0025] When the interior of the copper material is made of a substance other than copper, the thickness of the copper on the surface is not particularly limited, but is preferably 1 nm or more, more preferably 10 nm or more, and even more preferably 100 nm or more, for example. In this case, the copper on the surface of the copper material may be formed by plating using a copper plating solution.

[0026] The purity of the copper on the surface of the copper material is preferably, for example, 95% by mass or more, 99% by mass or more, or 99.9% by mass or more of pure copper. Even when the copper material is made entirely of copper, the purity of the copper is preferably within the above range. Examples of such copper include tough pitch copper, deoxidized copper, and oxygen-free copper. Among these, oxygen-free copper having an oxygen content of 0.001 to 0.0005% by mass is preferred.

[0027] Examples of the copper material include copper foils and copper plates, such as electrolytic copper foil, rolled copper foil, and carrier-attached copper foil. Here, copper foil refers to a material having a thickness of 100 μm or less, and copper plate refers to a material having a thickness of more than 100 μm. The thickness of the copper foil is preferably, for example, 0.1 μm or more, more preferably 0.5 μm or more, and even more preferably 1 μm or more. It is also preferably 80 μm or less, more preferably 50 μm or less. The thickness of the copper plate is, for example, preferably 0.3 mm or more, more preferably 0.5 mm or more, even more preferably 1 mm or more, and particularly preferably 5 mm or more. It is also preferably 5 cm or less, more preferably 3 cm or less, and even more preferably 1 cm or less.

[0028] The protrusions formed on the surface of the copper material are not particularly limited as long as they contain copper and / or copper oxide, but preferably contain copper oxide. Examples of methods for forming copper-containing protrusions on the surface of a copper material include plating treatment using a copper plating solution. Examples of methods for forming copper oxide-containing protrusions on the surface of a copper material include oxidation treatment. When copper oxide-containing protrusions are formed by oxidation treatment, a copper oxide layer, which will be described later, is formed on the surface of the copper material.

[0029] The height (average height) of the protrusions is not particularly limited, but is preferably 100 nm or more, more preferably 120 nm or more, even more preferably 150 nm or more, and particularly preferably 158 nm or more. Also, it is preferably 600 nm or less, more preferably 500 nm or less, even more preferably 400 nm or less, particularly preferably 350 nm or less, and most preferably 301 nm or less. The height of the protrusions can be measured, for example, by taking a cross-sectional image of a scanning electron microscope (SEM) and calculating the average value of the distance between the midpoint of a line segment connecting the minimum points of adjacent recesses across a convex portion at a predetermined interval and the maximum point of the convex portion between the recesses. More specifically, it can be measured, for example, by the method used in the examples described below.

[0030] In a scanning electron microscope (SEM) image obtained by observing a cross section perpendicular to the surface of a copper member using a focused ion beam (FIB), the number of protrusions having a height of 50 nm or more per any 3.8 μm is not particularly limited, but is preferably 10 or more, more preferably 13 or more, even more preferably 16 or more, and particularly preferably 18 or more. Also, for example, it is preferably 60 or less, more preferably 50 or less, even more preferably 45 or less, and particularly preferably 40 or less. The number of protrusions can be measured, for example, by the method used in the examples described below.

[0031] (Copper Oxide Layer) The copper member of the present invention may have a copper oxide layer formed on the surface of the copper material. That is, the copper member may include a copper material and a copper oxide layer formed on the surface of the copper material. When the copper member of the present invention includes a copper oxide layer, the adhesion between the copper member and the resin substrate and the heat resistance reliability are further improved. Examples of copper oxides in the copper oxide layer include copper oxide (CuO), cuprous oxide (CuO), and the like. ２ O), either one or both of which may be contained in the copper oxide layer. The content of copper oxide in the copper oxide layer is not particularly limited, and may be, for example, 0.1 mass % or more, 0.3 mass % or more, 0.5 mass % or more, 1 mass % or more, 3 mass % or more, 5 mass % or more, or 10 mass % or more. The copper oxide layer may be formed of copper hydroxide (Cu(OH) ２ ), and the content thereof is, for example, 0.01% by mass or more, 0.03% by mass or more, 0.05% by mass or more, 0.1% by mass or more, 0.5% by mass or more, 1% by mass or more, 3% by mass or more, or 5% by mass or more.

[0032] The thickness of the copper oxide layer is preferably 500 nm or less, more preferably 300 nm, even more preferably 200 nm or less, particularly preferably 160 nm or less, and most preferably 90 nm or less. Furthermore, the thickness of the copper oxide layer is preferably 20 nm or more, more preferably 30 nm or more, and even more preferably 40 nm or more. The thickness of the copper oxide layer refers to the thickness measured, for example, by SERA measurement, converted into a uniform thickness. More specifically, it can be measured, for example, by the method used in the examples described below.

[0033] The method for forming the copper oxide layer is not particularly limited, but examples thereof include a method of subjecting a copper material to an oxidation treatment using an oxidizing agent, and a method of subjecting the copper material after the oxidation treatment to a reduction treatment using a reducing agent.

[0034] (Metal Layer Other Than Copper) In the copper member of the present invention, a metal layer other than copper may be formed on part or all of the surface of the copper material so as to cover the protrusions formed on the surface of the copper material. When a copper oxide layer is formed on the surface of the copper material, a metal layer other than copper may be formed so as to cover part or all of the surface of the copper oxide layer. The metal other than copper can be identified, for example, by energy dispersive X-ray analysis (EDX) using a transmission electron microscope (TEM) on the surface and / or cross section of the metal layer.

[0035] The term "metal layer other than copper" refers to a layer containing a metal other than copper. Examples of metals other than copper include magnetic metals and non-magnetic metals other than copper. Examples of magnetic metals include Ni, Co, Fe, and Gd. Examples of non-magnetic metals other than copper include Zn, Cr, Mo, Ti, Al, and Mn. When the metal layer simultaneously contains a magnetic metal and a non-magnetic metal other than copper, the transmission loss in the copper member tends to be low. When the metal layer simultaneously contains a magnetic metal and a non-magnetic metal other than copper, examples of such combinations include Ni-Cr, Ni-Zn, Ni-Mn, Co-Cr, Co-Zn, Co-Mn, and Al-Ni-Co. Among these, when the metal layer contains Ni, the copper member tends to have better adhesion to the resin substrate and better heat resistance reliability, possibly because the surface of the copper member becomes softer than when the metal layer contains other metals. Furthermore, when the metal layer is a layer containing Ni and Zn (Ni—Zn), the surface of the copper member tends to have a moderate softness while having a higher elastic modulus than a layer containing Ni. The elastic modulus of the surface of the copper member is due to the hardness of the protrusions, and this higher elastic modulus makes the protrusions less likely to break or collapse when the copper member is laminated to the resin substrate. Therefore, a layer containing Ni and Zn, which imparts a high elastic modulus to the surface of the copper member, tends to have better adhesion to the resin substrate and heat resistance reliability. Furthermore, if the metal layer is magnetic, it is significantly affected by the skin effect, which is undesirable from the perspective of transmission loss. When the metal layer is a layer containing Ni and Zn (Ni—Zn), although it contains ferromagnetic Ni, the presence of Zn causes magnetic transformation, changing it from a ferromagnetic to a paramagnetic material, thereby achieving excellent transmission loss without being affected by the skin effect due to magnetism. The magnetic transformation of Ni by Zn tends to occur when the ratio of the amount of Zn attached per unit area to the total amount of Ni and Zn attached per unit area is around 20% (e.g., 10% or more, 16% or more, 19% or more, or 25% or more).

[0036] In a layer containing a magnetic metal and a non-magnetic metal other than copper, the deposition ratio of the non-magnetic metal other than copper per unit area to the total deposition amount of the magnetic metal and the non-magnetic metal other than copper per unit area is not particularly limited, but is, for example, 10% or more, 16% or more, 19% or more, 25% or more, 30% or more, 40% or more, 50% or more, 60% or more, 70% or more, 73% or more, 75% or more, or 78% or more. Also, for example, it is less than 100%, 95% or less, 92% or less, 90% or less, or 87% or less. The deposition amount of the magnetic metal or non-magnetic metal other than copper per unit area can be calculated, for example, by dissolving the magnetic metal in an acidic solution, measuring the amount of metal by ICP analysis, and dividing the result by the planar field area of ​​the structure.

[0037] In the layer containing a magnetic metal and a non-magnetic metal other than copper, the deposition amount (total amount) of the magnetic metal and the non-magnetic metal other than copper per unit area is not particularly limited, but is, for example, 0.60 mg / dm ２ More preferably, 1.0 mg / dm ２ More preferably, 1.5 mg / dm ２ More preferably, 1.8 mg / dm ２ or more, most preferably 2.0 mg / dm ２ or more. Also, for example, 15.0 mg / dm ２ It is preferable that the concentration is 12.0 mg / dm or less, and more preferably 12.0 mg / dm ２ More preferably, 10.0 mg / dm ２ Below 9.0 mg / dm ２ When the deposition amount (total amount) per unit area of ​​the magnetic metal and the non-magnetic metal other than copper is within the above range, adhesion to the resin substrate and heat resistance reliability tend to be excellent.

[0038] In the layer containing a magnetic metal and a non-magnetic metal other than copper, the amount of the non-magnetic metal other than copper deposited per unit area is not particularly limited, but is, for example, 0.25 mg / dm ２ It is preferable that the concentration is equal to or higher than 0.40 mg / dm ２ More preferably, 0.60 mg / dm ２ More preferably, 1.0 mg / dm ２ More preferably, 1.3 mg / dm２ or more, most preferably 1.6 mg / dm ２ or more. Also, for example, 15.0 mg / dm ２ It is preferable that the concentration is 12.0 mg / dm or less, and more preferably 12.0 mg / dm ２ More preferably, 9.0 mg / dm ２ Below 7.5 mg / dm ２ By keeping the deposition amount per unit area of ​​the non-copper non-magnetic metal within the above range, adhesion to the resin substrate and heat resistance reliability tend to be excellent. In addition, the transmission loss of the metal member tends to be further reduced.

[0039] In the layer containing a magnetic metal and a non-magnetic metal other than copper, the amount of magnetic metal deposited per unit area is not particularly limited, but is, for example, 0.01 mg / dm ２ It is preferable that the concentration is 0.05 mg / dm or more, and more preferably 0.05 mg / dm ２ More preferably, 0.1 mg / dm ２ More preferably, 0.15 mg / dm ２ or more, most preferably 0.2 mg / dm ２ or more. Also, for example, 5.0 mg / dm ２ It is preferably 2.5 mg / dm or less, more preferably 2.5 mg / dm ２ More preferably, 1.2 mg / dm ２ Below 1.0 mg / dm ２ When the amount of magnetic metal attached per unit area is within the above range, adhesion to the resin substrate and heat resistance reliability tend to be excellent. In addition, since the amount of magnetic metal attached per unit area is relatively low, the transmission loss of the metal member tends to be further reduced.

[0040] In a layer containing a magnetic metal and a non-magnetic metal other than copper, the ratio of the amount of Mo deposited per unit area to the total amount of the magnetic metal and the non-magnetic metal deposited per unit area is not particularly limited, but is preferably 1% or less, more preferably 0.7% or less, even more preferably 0.4% or less, and even more preferably 0.0%.

[0041] The metal layer other than copper is formed, for example, by plating the surface of the copper material or copper oxide layer using a plating solution. The plating solution is not particularly limited as long as it contains a metal other than copper. The plating method is not particularly limited, and plating can be performed by electroplating, electroless plating, vacuum deposition, chemical conversion treatment, etc., but electroplating is preferred because it is preferable to form a uniform plating layer.

[0042] The thickness (equivalent to a planar surface) of the metal layer other than copper is not particularly limited, but is preferably 1 to 190 nm, more preferably 5 to 160 nm, even more preferably 10 to 120 nm, particularly preferably 20 to 100 nm, and most preferably 30 to 80 nm. When the thickness of the metal layer is within the above range, the metal layer tends to be uniformly distributed, resulting in better adhesion to the resin substrate and better heat resistance reliability. When the metal layer is thin, the metal layer is not uniformly distributed but exists discretely, resulting in poorer adhesion and heat resistance reliability. The thickness (equivalent to a planar surface) of the metal layer other than copper can be calculated using the method described in the "Plating Thickness (equivalent to a planar surface)" section of the Examples below.

[0043] The thickness (converted surface area) of the metal layer other than copper is not particularly limited, but is preferably 0.1 to 100 nm, more preferably 0.4 to 50 nm, even more preferably 0.8 to 30 nm, particularly preferably 1 to 20 nm, and most preferably 2 to 10 nm. When the thickness of the metal layer is within the above range, the metal layer tends to be uniformly distributed, resulting in better adhesion to the resin substrate and better heat resistance reliability. When the metal layer is thin, the metal layer is not uniformly distributed but exists discretely, resulting in poorer adhesion and heat resistance reliability. The thickness (converted surface area) of the metal layer other than copper can be calculated using the method described in the "Plating Thickness (Converted Surface Area)" section of the Examples below.

[0044] (Silicon Compound Layer) In the copper member of the present invention, a silicon compound layer may be formed on a part or all of the surface of the copper material, the copper oxide layer, and the metal layer other than copper. In particular, it is preferable that a silicon compound layer is formed on a part or all of the surface of the metal layer. By including a silicon compound layer, the copper member of the present invention tends to have further improved heat resistance reliability.

[0045] The silicon compound layer is a layer containing a silicon compound. In the silicon compound layer, "containing a silicon compound" includes not only an embodiment containing the silicon compound itself, but also an embodiment in which a portion of the silicon compound is chemically bonded to a material in contact with the silicon compound layer. Examples of such materials include copper materials, copper oxide contained in a copper oxide layer, and metals contained in a metal layer other than copper. Specific examples include an embodiment in which a portion of a silane coupling agent is chemically bonded to the above material by a silane coupling treatment described below. That is, the silicon compound layer may be formed by a coupling treatment such as silane coupling.

[0046] Examples of the silicon compounds include SiO, SiO ２ , SiO ４ Si etc. x O y Silicon oxide represented by the formula: SiO ４ H ４ , Si ２ O ７ H ６ , SiO ３ H ２ , Si ２ O ５ H ２ Si etc. x O ｙ H ｚ Silicon hydroxide represented by the formula: ２ SiO ３) and other inorganic silicon compounds; alkoxysilanes, silane coupling agents, polyether-modified silicones, silicon carbides, silicon sulfides, silicon nitrides and other organic silicon compounds; and silicon halides. Examples of the silane coupling agent include those having two or three hydrolyzable groups, and those in which the hydrolyzable group is a methoxy group or an ethoxy group. Examples of the silane coupling agent include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidyloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, vinyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-isocyanatepropyltriethoxysilane, 3-ureidopropyltrialkoxysilane, and 3-acryloxypropyltrimethoxysilane. An example of the embodiment in which a part of the silicon compound is chemically bonded to the above-mentioned material is, for example, an embodiment in which the SiO group derived from a silane coupling agent is chemically bonded to the above-mentioned material. In the silicon compound layer, the above-mentioned silicon compounds can be used alone or in combination of two or more.

[0047] Methods for confirming the silicon compound layer, that is, methods for confirming whether or not the silicon compound is contained in the silicon compound layer, include, for example, elemental analysis by time-of-flight secondary ion mass spectrometry (TOF-SIMS) or X-ray photoelectron spectroscopy (XPS).

[0048] The copper member according to the present invention can be suitably used in applications requiring high adhesion to resin substrates and heat resistance reliability. For example, in the form of a laminate in which a copper member and a resin substrate are laminated, it can be suitably used as a material for printed circuit boards such as printed wiring boards and semiconductor package substrates, or for lithium-ion batteries. Examples of printed wiring boards include flexible copper clad laminates (FCCL) for flexible printed circuits (FPCs), copper clad laminates (CCL) for rigid substrates, and build-up materials. It can also be used as a peelable copper foil.

[0049] Examples of the resin substrate include at least one insulating resin selected from the group consisting of polyphenylene ether (PPE), epoxy, polyphenylene oxide (PPO), polybenzoxazole (PBO), polytetrafluoroethylene (PTFE), liquid crystal polymer (LCP), thermoplastic polyimide (TPI), fluororesin, polyetherimide, polyether ether ketone, polycycloolefin, bismaleimide resin, low dielectric constant polyimide, and cyanate resin.

[0050] Figure 1 is a schematic cross-sectional view showing one embodiment of the copper member of the present invention. 1 is a copper member, 2 is a copper material, 3 is a copper oxide layer, 4 is a protrusion, and 5 is a metal layer other than copper. A silicon compound layer is not shown, but may be formed on the surface of metal layer 5. Protrusion 4 is part of copper oxide layer 3 and contains copper oxide. Metal layer 5 is formed on the surface of copper oxide layer 3. Figure 2 is a schematic cross-sectional view showing one embodiment of a laminate of a copper member and a resin substrate of the present invention. 10 is a laminate, 11 is a copper member, and 12 is a resin substrate.

[0051] [Method for manufacturing a copper member] An example of a method for manufacturing a copper member of the present invention will be described below, but the manufacturing method is not limited to this. The method for manufacturing a copper member of the present invention includes, for example, the following steps: - A step of forming protrusions containing copper and / or copper oxide on the surface of a copper material (protrusion forming step) - A step of plating the surface of the obtained copper material after the protrusion forming step using a plating solution (plating step) - A step of treating the surface of the obtained copper material after the plating step with a coupling agent (coupling step)

[0052] Furthermore, when a laminate is produced using the copper member of the present invention and a resin substrate, the method for producing the laminate may further include the following steps: - a step of laminating the obtained copper material and the resin substrate after the coupling treatment step so that the protrusions formed on the surface of the copper material come into contact with the resin substrate to form a laminate (laminate formation step).

[0053] (Protrusion Forming Process) The protrusion forming process is a process of forming protrusions containing copper and / or copper oxide on the surface of a copper material. A method for forming copper-containing protrusions (particularly protrusions made of copper) on the surface of a copper material includes plating with a copper plating solution. That is, this process may be a process (copper plating process) in which protrusions containing copper are formed by plating the surface of a copper material with a copper plating solution. An example of a method for forming copper oxide-containing protrusions (particularly protrusions made of copper oxide) on the surface of a copper material includes oxidation treatment. When protrusions containing copper oxide are formed by oxidation treatment, a copper oxide layer is formed on the surface of the copper material. That is, this process may be a process (oxidation treatment process) in which protrusions containing copper oxide are formed by oxidation treatment on the surface of a copper material.

[0054] The oxidation treatment step is a step of forming protrusions containing copper oxide on the surface of a copper material by oxidation treatment. This step also forms a copper oxide layer on the surface of the copper material. The oxidation treatment in this step roughens the surface of the copper material, improving its adhesion to a resin substrate.

[0055] In the oxidation treatment step, before the oxidation treatment, a surface roughening treatment such as soft etching or etching, a degreasing treatment, an acid cleaning treatment for removing a natural oxide film from the copper material, an alkali treatment after the acid cleaning treatment, etc. The alkali treatment is not particularly limited, but an example is a method in which the copper is treated with a 0.1 to 10 g / L or 1 to 2 g / L aqueous alkali solution (e.g., an aqueous sodium hydroxide solution) at 30 to 50°C for about 0.5 to 2 minutes.

[0056] The method of oxidation treatment is not particularly limited, and examples thereof include a method using an oxidizing agent, a method using thermal oxidation, and a method using electrolytic oxidation. Among these, a method using an oxidizing agent is preferred from the viewpoint of improving adhesion to a resin substrate.

[0057] The oxidizing agent is not particularly limited, but for example, an aqueous solution of a chlorate such as sodium chlorite, sodium hypochlorite, potassium chlorate, or potassium perchlorate is preferably used. The oxidizing agent may contain additives such as a phosphate such as trisodium phosphate dodecahydrate, an alkali such as potassium hydroxide, or a surfactant molecule. One or more of the oxidizing agents may be used.

[0058] When oxidation treatment is performed using an oxidizing agent, the treatment temperature is not particularly limited, but is preferably, for example, 30 to 95°C, and more preferably 40 to 80°C. The treatment time is not particularly limited, but is preferably, for example, 0.2 to 30 minutes, and more preferably 0.4 to 10 minutes. The concentration of the oxidizing agent (e.g., the concentration of the chlorate) is not particularly limited, but is preferably, for example, 5 to 400 g / L, and more preferably 10 to 300 g / L.

[0059] After the oxidation treatment step, the surface of the copper material may be subjected to a reduction treatment using a reducing agent. By the reduction treatment, cuprous oxide (copper(I) oxide) may be formed on the surface of the copper material. The reducing agent is not particularly limited, but examples thereof include solutions of boron compounds such as dimethylamine borane (DMAB), diborane, sodium borohydride, and hydrazine.

[0060] Furthermore, the size, thickness, height, length, etc. of the copper oxide-containing protrusions may be adjusted by chelating the surface of the copper material using a chelating agent (particularly a biodegradable chelating agent). The chelating agent is not particularly limited, but examples include solutions of ethylenediaminetetraacetic acid, diethanolglycine, tetrasodium L-glutamate diacetate, ethylenediamine-N,N'-disuccinic acid, sodium 3-hydroxy-2,2'-iminodisuccinate, trisodium methylglycine diacetate, tetrasodium aspartate diacetate, disodium N-(2-hydroxyethyl)iminodiacetate, sodium gluconate, nickel chloride, etc. The pH of the chelating agent is not particularly limited, but is preferably alkaline, more preferably pH 8 to 10.5, even more preferably pH 9.0 to 10.5, and even more preferably pH 9.8 to 10.2. The chelating agents may be used singly or in combination.

[0061] (Plating step) The plating step is a step in which the surface of the copper material is plated using a plating solution after the protrusion forming step. The plating method is not particularly limited, and examples thereof include electroplating, electroless plating, vacuum deposition, and chemical conversion treatment. However, electroplating is preferred from the viewpoint of forming a uniform plated layer. This step allows the formation of a metal layer other than copper as described above.

[0062] When forming a layer containing a magnetic metal and a non-magnetic metal other than copper, plating may be performed using a plating solution containing either magnetic metal ions or non-magnetic metal ions other than copper, followed by plating using a plating solution containing the other ions, or plating may be performed using a plating solution containing both magnetic metal ions and non-magnetic metal ions other than copper. For example, if the magnetic metal and non-magnetic metal other than copper are Ni and Zn, the plating solution containing nickel ions may contain nickel sulfate, nickel pyrophosphate, nickel chloride, nickel oxide, nickel carbonate, nickel hydroxide, nickel nitrate, nickel sulfamate, etc., and the plating solution containing zinc ions may contain zinc sulfate, zinc pyrophosphate, zinc chloride, zinc oxide, zinc carbonate, zinc hydroxide, zinc nitrate, zinc sulfide, zinc sulfamate, etc. The plating solution may also contain additives such as a pH buffer and a brightener.

[0063] When electrolytic plating is applied to the surface of an oxidized copper material, the copper oxide on the surface is first reduced to cuprous oxide or pure copper using an electric charge. Then, the metal corresponding to the electrolytic plating used begins to deposit, forming a metal layer. The amount of electric charge required varies depending on the type of plating solution and the amount of copper oxide. For example, when Ni plating is applied to a copper material, the area dm of the copper material to be electrolytically plated is ２ It is preferable to apply a charge of 5 C or more and 90 C or less, and more preferable to apply a charge of 10 C or more and 65 C or less per unit area dm of the copper material to be electrolytically plated. ２ It is preferable to apply a charge of 5 C or more and 90 C or less per charge, and it is more preferable to apply a charge of 10 C or more and 65 C or less.

[0064] The current density in electroplating is not particularly limited, but is preferably 0.2 A / dm ２ ~10A / dm ２ It is preferable to use a current having a different current density for the time until the oxide contained in the protrusions on the surface of the copper material is partially reduced and for the time during which the plating is being coated.

[0065] (Coupling Treatment Step) The method for producing a copper member may include a step of performing a coupling treatment on the oxidized copper material.

[0066] The coupling agent for treating the copper material is not particularly limited, but a silane coupling agent is preferred. Examples of the silane coupling agent include those described in the section on the silicon compound layer above. When a silane coupling agent is used as the coupling agent for treating the copper material, the silicon compound layer described above can be formed.

[0067] The specific method of coupling treatment is not particularly limited, and examples include a method of applying the coupling agent solution to the surface of the copper material using a roller or bar coater, a method of spraying it, or a method of immersing the copper material in the coupling agent solution. After treating the copper material with the coupling agent solution, it is dried. The temperature and time for drying are not particularly limited as long as the solvent is completely evaporated, but drying at 70°C for 1 minute or more is preferred. Examples of solvents used in the coupling agent solution include water, organic solvents, and mixed solvents thereof. The concentration of the coupling agent is not particularly limited, but is preferably 0.5 to 20% by mass or less.

[0068] (Laminate Forming Process) The laminate forming process is a process of laminating a resin substrate and a copper material to form a laminate. More specifically, it is a process of laminating a resin substrate and a copper material so that the resin substrate and the protrusions formed on the surface of the copper material abut against each other to form a laminate. In this process, the laminate may be formed by applying pressure to the laminate while heating it as needed. That is, this process may be a process of laminating a resin substrate and a copper material so that the protrusions formed on the surface of the resin substrate and the copper material abut against each other, and then applying pressure while heating it as needed to form a laminate.

[0069] The resin substrate is not particularly limited, but preferably contains at least one insulating resin selected from the group consisting of polyphenylene ether (PPE), epoxy, polyphenylene oxide (PPO), polybenzoxazole (PBO), polytetrafluoroethylene (PTFE), liquid crystal polymer (LCP), thermoplastic polyimide (TPI), fluororesin, polyetherimide, polyetheretherketone, polycycloolefin, bismaleimide resin, low dielectric constant polyimide, and cyanate resin. That is, the resin substrate is preferably an insulating substrate.

[0070] The thickness of the resin substrate is not particularly limited, but is preferably 0.1 to 500 μm, more preferably 0.5 to 300 μm, and even more preferably 1 to 200 μm. The resin substrate may further contain an inorganic filler or glass fiber. The relative dielectric constant of the resin substrate is preferably 5.0 or less, more preferably 4.0 or less, and even more preferably 3.8 or less. The dielectric loss tangent is preferably 0.03 or less, more preferably 0.01 or less, and even more preferably 0.005 or less.

[0071] The present invention will be described in more detail below based on examples, but the present invention is not limited to these examples.

[0072] [Manufacturing of Copper Members] In Examples 1 to 10 and Comparative Examples 1 to 4, copper members were manufactured using copper foil (product name: DR-WS, thickness: 18 μm, manufactured by Furukawa Electric Co., Ltd.) as the copper material. Specifically, the shiny side of the copper foil was subjected to the following treatments in Examples 1 to 7, 9, and 10 and Comparative Examples 1 to 4, and the matte side of the copper foil was subjected to the following treatments in Example 8. Each treatment is described in detail below. Conditions for some of the treatments are also shown in Table 1. The shiny side is also called the glossy side, and refers to a side that is flatter than the other side. The other side is called the matte side (non-glossy side).

[0073] Alkaline degreasing treatment: The copper foil was degreased by immersing it in a 40 g / L aqueous sodium hydroxide solution at a liquid temperature of 50°C for 1 minute, and dirt on the copper surface was removed. The copper foil was then rinsed with water. Acid cleaning treatment: Next, the copper foil that had been subjected to the alkaline degreasing treatment was acid-cleaned by immersing it in a 10 mass% aqueous sulfuric acid solution at a liquid temperature of 25°C for 2 minutes. The oxide film on the copper surface was removed. The copper foil was then rinsed with water. Pre-dip treatment: The copper foil that had been subjected to the acid cleaning treatment was then immersed in a 1.2 g / L aqueous sodium hydroxide solution (pH 10.5) at 40°C for 1 minute to prevent acid contamination in the subsequent oxidation treatment.

[0074] Oxidation Treatment In Examples 1 to 10 and Comparative Examples 3 and 4, the copper foils that had been pre-dip treated were subjected to an oxidation treatment using the oxidizing agent and treatment conditions shown in Table 1, to form a copper oxide layer on the surface of the copper foil. For example, in Example 1, the shiny side of the copper foil was immersed in an oxidizing agent consisting of 46 g / L sodium chlorite, 12 g / L potassium hydroxide, and 1.5 g / L 3-glycidoxypropyltrimethoxysilane (product name: KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.) at 73°C for 120 seconds to undergo oxidation treatment. The copper foil was then rinsed with water at room temperature for 1 minute.

[0075] Plating Treatment In Examples 1 to 10 and Comparative Examples 3 and 4, the copper foils after oxidation treatment, and in Comparative Example 2, the copper foils that had not been subjected to oxidation treatment, were plated using the plating solution and treatment conditions of the formulations shown in Table 1 to form plating layers on the surfaces of the copper foils. For example, in Example 1, the copper foils after oxidation treatment were immersed in a Ni-Zn electroplating solution (a plating solution consisting of a Ni ion concentration of 0.3 g / L (nickel sulfate hexahydrate was used as the Ni source), a Zn ion concentration of 4 g / L (zinc diphosphate was used as the Zn source), and 80 g / L potassium diphosphate) at 40°C, and then immersed in a plating solution at a current density of 0.5 A / dm for 65 seconds. ２ For example, in Comparative Example 3, the copper foil was immersed in a Ni electroplating solution (containing a Ni ion concentration of 53.6 g / L (nickel sulfate hexahydrate was used as the Ni source) and 30 g / L of boric acid) at a solution temperature of 45°C, and then subjected to electroplating for 130 seconds at a current density of 0.5 A / dm ２ The electrolytic plating treatment was carried out under the conditions of: After that, the obtained copper foil was washed with water and dried.

[0076] Coupling Treatment The copper foils after plating in Examples 1 to 10 and Comparative Examples 2 to 4 were immersed for 60 seconds in a 1% by volume aqueous solution of 3-aminopropyltriethoxysilane (product name: KBE-903, manufactured by Shin-Etsu Chemical Co., Ltd.) at a liquid temperature of 25°C, followed by baking by drying at 110°C for 1 minute.

[0077] [Evaluation] The following evaluations were carried out on the copper members obtained in Examples 1 to 10 and Comparative Examples 1 to 4. For convenience, the copper foil of Comparative Example 1 will be referred to as the copper member hereinafter.

[0078] (Evaluation 1: Measurement of Copper Oxide Layer Thickness) For the treated surfaces of the copper members of Examples 1 to 10 and Comparative Examples 2 to 4, the thickness of the copper oxide layer before plating was measured by the SERA method. A Surface-Scan QC-100 (manufactured by ECI Corporation) was used as the measuring device. The measurement was performed using a boric acid aqueous solution (6.18 g / L boric acid, 9.55 g / L sodium tetraborate) at a constant current (90 μA / cm ２ The reduction reaction was carried out at the following voltage ranges, and the reduction time was measured: ２ The obtained reduction time and the current density were substituted into the following equation to convert the film thickness: ２ O film thickness (nm) = 0.0124 × current density (μA / cm ２ ) × reduction time (sec) × 0.1 CuO film thickness (nm) = 0.00639 × current density (μA / cm ２ )×reduction time (sec)×0.1 The calculated thickness of the copper oxide layer is shown in the section “Thickness (nm) of copper oxide layer” in Table 1.

[0079] (Evaluation 2-1: Measurement of Average Protrusion Height) The height of the protrusions was measured on the treated surfaces of the copper members of Examples 1 to 10 and Comparative Examples 1 to 4, and on one side of the copper member of Comparative Example 1. Specifically, a FIB-SEM (AURIGA, manufactured by Carl Zeiss K.K.) was used to expose a cross section perpendicular to the copper foil, and a cross-sectional image was taken at an acceleration voltage of 2 kV and a magnification of 30,000x. In the obtained cross-sectional image, the distance between the midpoint of the line segment connecting the minimum points of adjacent recesses across a convex portion and the maximum point of the convex portion between the recesses was measured as the height of the protrusion, and the length was measured. In the same manner, the heights of five protrusions were measured, and the average value was calculated. Note that the obtained cross-sectional image was divided into six equal parts at equal horizontal distances, and the protrusions closest to the dividing line were selected. The measurement results are shown in the "Average Height (nm)" section of "Protrusion" in Table 1.

[0080] (Evaluation 2-2: Measurement of the number of protrusions) The number of protrusions was measured on the treated surfaces of the copper members of Examples 1 to 10 and Comparative Examples 1 to 4, and on one side of the copper member of Comparative Example 1. Specifically, a cross-sectional image was taken at 50,000 magnification using a scanning electron microscope (SEM) that observed a cross section perpendicular to the treated surface using a focused ion beam (FIB), and an arbitrary cross-sectional length of 3.8 μm was selected, and the number of protrusions with a height of 50 nm or more within that length was counted. The number (number) of protrusions is shown in the "Number" section of "Protrusions" in Table 1.

[0081] (Evaluation 3: Measurement of Surface Area Ratio) For the copper members of Examples 1 to 10 and Comparative Examples 1 to 4, the surface area ratio was calculated using the following formula, and the measurement results are shown in the "Surface Area Ratio" section of Table 1. Surface Area Ratio = (BET measured surface area (dm ２ ) - Plan view area of ​​copper member (dm ２ )) / planar view area of ​​copper member (dm ２ )

[0082] BET measured surface area (dm ２ ) was measured by the krypton gas adsorption BET multipoint method using a multi-sample high-performance specific surface area analyzer 3FLEX manufactured by Micromeritics Co., Ltd. Before the measurement, each copper member was pretreated by drying under reduced pressure at 100°C for 2 hours. The test pieces used for the measurement were cut into 110 pieces of 30 mm x 7 mm per 3.83 g of original copper foil.

[0083] In addition, since the surface area measurement by the BET method measures the surface area of ​​the entire surface of the test piece introduced into the device, it is not possible to measure the surface area of ​​only the treated surface of the copper member that has been treated on only one side. Therefore, the surface area ratio of the untreated side (the side opposite the treated side) is considered to be 1, that is, the same as the area of ​​the test piece (the "planar area of ​​the copper member" in the formula for the surface area ratio), and the surface area ratio is calculated. In addition, in the surface area measurement by the BET method, surfaces other than the treated surface and its opposite side (side surface) are also included in the measurement, but since their areas are negligible compared to the treated surface and its opposite side, they are not taken into account in the calculation formula for the surface area ratio.

[0084] (Evaluation 4: Measurement of Ni and Zn Adhesion Amounts per Unit Area) The Ni and Zn adhesion amounts per unit area were measured for the treated surfaces of the copper members of Examples 1 to 10 and Comparative Examples 1 to 4. First, the copper members were dissolved in 12% nitric acid, and the concentrations of each metal component in the resulting liquid were measured using an ICP optical emission spectrometer 5100 SVDV ICP-OES (manufactured by Agilent Technologies Inc.), and these were taken as the adhesion amounts per unit area of ​​the copper members used. In addition, the "Zn (mg / dm ２ " and "Ni (mg / dm ２ Furthermore, the ratio of the Zn deposition amount of the layer containing Ni and Zn per unit area was calculated using the following formula: "Ratio of the Zn deposition amount of the layer containing Ni and Zn" = Zn deposition amount (mg / dm ２ ) / [Ni deposition amount (mg / dm ２ ) + Zn deposition amount (mg / dm ２ ) × 100 (%)

[0085] The measurement results (calculated results) are shown in Table 1 under "Plating weight" as "Zn (mg / dm ２ )”, “Ni (mg / dm ２ )”, “Total (mg / dm ２ ) and "Zn deposition amount ratio (%)".

[0086] (Evaluation 5: Calculation of plating layer thickness) (1) Plating thickness (flat surface equivalent) The plating thickness in flat surface equivalent was calculated using the following formula: "Plating thickness (flat surface equivalent) (nm)" = (metal deposition amount per unit area (mg / dm ２ ) / metal density (g / cm ３ )) × 100 (2) Plating Thickness (Converted to Surface Area) The thickness of the metal layer in terms of surface area was calculated using the following formula: "Plating Thickness (Converted to Surface Area) (nm)" = [(Metal Deposition Amount per Unit Area (mg / dm ２ ) / metal density (g / cm ３ )) × 100] / surface area ratio The Zn density is 7.14 g / cm ３ , Ni density is 8.91 g / cm ３The plating thickness was calculated assuming that the contained metals were Zn and Ni. That is, the total plating thickness was calculated as the sum of the calculated value of the plating thickness when the metal was Zn and the calculated value of the plating thickness when the metal was Ni.

[0087] The "Thickness of plating layer (converted to flat surface)" and "Thickness of plating layer (converted to surface area)" sections of Table 1 show the thickness (nm) when the metal is Zn, the thickness (nm) when the metal is Ni, and the calculated value (nm) of the total thickness of the plating layer.

[0088] (Evaluation 6: Measurement of surface roughness (Ra and Rz)) The surface shape of the treated surfaces of the copper members of Examples 1 to 10 and Comparative Examples 1 to 4 was measured using a confocal scanning electron microscope OPTELICS H1200 (manufactured by Lasertec Corporation), and the surface roughness (Ra and Rz) was calculated according to the method specified in JIS B 0601:2013 (international standard ISO4287-1997). The measurement conditions were: scan width 100 μm, scan type area, light source Blue, and cutoff value 1 / 5. The object lens was set to ×100, the contact lens to ×14, the digital zoom to ×1, and the Z pitch to 10 nm. Data was obtained from three locations, and the average values ​​of the three locations for Ra and Rz were calculated. The measurement results are shown in the "Ra (μm)" and "Rz (μm)" sections of "Surface roughness" in Table 1.

[0089] (Evaluation 7: Measurement of indentation creep) For the treated surfaces of the copper members of Examples 1 to 10 and Comparative Examples 1 to 4, an ultra-microindentation hardness tester (nanoindenter, product name: ENT-NEXUS, manufactured by Elionix Co., Ltd.) was used to press an indenter into the surface of the copper member in an atmosphere of 30°C, applying a load at a pressing rate of 0.1 mN / s. The load was released when the indentation depth reached 10 nm. The indentation creep (C) was calculated by the following formula, taking the distance the indenter had pressed into 5 seconds after the load was released as h (nm). ＩＴ The calculated values ​​were recorded as "Indentation creep (C ＩＴ ")" section. ＩＴ )(%)=[(h-10) / 10]×100

[0090] The measurement procedure is described in detail below. (1) The copper member is set in the nanoindenter. (2) Measurement is started, and the diamond triangular pyramidal indenter (Berkovich indenter) is lowered onto the copper member. The position where a sudden change in displacement occurs when the tip of the indenter comes into contact with the surface of the copper member is regarded as the surface position of the copper member. In other words, this position is regarded as the surface of the copper member and is used as the reference point for depth. (3) The indenter continues to be lowered (pressed into the copper member), and when the depth of the indentation from the surface (= indentation depth) reaches 10 nm, the indentation is stopped while maintaining the load. Note that the load (stress) itself remains even after the indentation is stopped, so the indentation continues. (4) Five seconds after the indentation is stopped, the depth of the indentation pressed by the indenter (depth of the indentation from the reference point) is taken as h (nm). (5) From the value of h, the indentation creep (C ＩＴ ) (%) is calculated.

[0091] (Evaluation 8: Measurement of maximum indentation depth) The treated surfaces of the copper members of Examples 1 to 10 and Comparative Examples 1 to 4 were indented using a nanoindenter in an atmosphere of 30°C, with a load applied to the surface of the copper member at an indentation rate of 0.1 mN / s. The load was released when the indentation depth reached 10 nm. The deepest position of the indentation created by the indenter was then recorded in the "Maximum indentation depth (nm)" section of Table 1.

[0092] (Evaluation 9: Measurement of indentation hardness and indentation elastic modulus) The indentation hardness (GPa) and indentation elastic modulus (GPa) were measured for the treated surfaces of the copper members of Examples 1 to 10 and Comparative Examples 1 to 4. The measurement conditions are described below.

[0093] Using an ultra-microindentation hardness tester (nanoindenter, product name: ENT-NEXUS, manufactured by Elionix Co., Ltd.), a load was applied to the surface of the copper member at a rate of 0.1 mN / s in an atmosphere of 30 ° C. The load was released when the indentation depth reached 10 nm. The position where a sudden change in displacement occurred when the tip of the indenter contacted the surface of the copper member was considered to be the surface position of the copper member. In other words, this position was considered to be the surface of the copper member and was used as the reference point for depth. From the graph of the applied load and indentation depth (displacement) at this time, the indentation hardness and indentation modulus were calculated using an analysis method in accordance with ISO 14577-1. Note that in the unloading fitting, since the initial part of the unloading curve was not linear, the maximum indentation depth (hmax) was determined using values ​​fitted at F = 20% and 95% (so-called power low fit).

[0094] The set indentation depths were 10 nm, 100 nm, 200 nm, and 500 nm. Measurements were performed at 20 points for each set indentation depth, and the test was repeated three times (n = 3). Taking measurement error into consideration, the average value of a total of 30 points was calculated for each set indentation depth, excluding the top 25% and bottom 25% for each set indentation depth (n). The "set indentation depth" refers to the indentation depth from the surface position of the copper member when a load is applied to the surface of the copper member, the indenter is pressed into the surface, and then the load is removed.

[0095] The indentation hardness (GPa) and indentation modulus (GPa) of the copper member measured by the above method at set indentation depths from the surface of the copper member of 10 nm, 100 nm, 200 nm, and 500 nm are shown in the "Indentation hardness (GPa)" and "Indentation modulus (GPa)" sections of Table 1, respectively.

[0096] (Evaluation 10: Measurement of Peel Strength) Each resin substrate listed in Table 1 was thermocompression bonded to the treated surface of the copper members of Examples 1 to 10 and Comparative Examples 1 to 4 under the following conditions using a vacuum press to prepare measurement samples. The resin substrates used were ADFLEMA (relative permittivity (Dk): 2.3, dielectric dissipation factor (Df): 0.0012, manufactured by Namics Corporation), R1551GG (manufactured by Panasonic Industries Co., Ltd.), and R5680 (manufactured by Panasonic Industries Co., Ltd.). The thermocompression bonding conditions for each are as follows: ADFLEMA: Thermocompression bonding was performed by holding at 1 MPa in an atmosphere of 200°C for 120 minutes. The degree of vacuum was 10 kPa or less. R1551: Pressure bonding was performed at 1 MPa while heating until the temperature reached 100°C, and after reaching 100°C, the temperature was held at the same temperature for 5 to 10 minutes. After that, the temperature reached 180°C under a pressure of 3.3 MPa, and the thermocompression bonding was performed by holding the same temperature for 50 minutes. The degree of vacuum was set to 13.3 kPa or less, and evacuation was stopped 60 minutes after the start of pressing. - R5680: The thermocompression bonding was performed at 0.49 MPa while heating to 110°C, and then at 210°C and 2.94 MPa for 120 minutes. The degree of vacuum was set to 13.3 kPa or less, and evacuation was stopped when the temperature reached 110°C.

[0097] The measurement samples obtained above were subjected to a 90° peel test (Japanese Industrial Standards (JIS) C5016) to measure the peel strength (kgf / cm) when the copper foil was peeled from the resin substrate in a 90° direction at a rate of 50 mm / min. The measurement width of the measurement sample was 10 mm. The measurement results are shown in the "Initial" section of "Peel strength (kgf / cm)" in Table 1.

[0098] The measurement samples obtained above were heated at 125°C for 1000 hours, and then the peel strength (kgf / cm) was measured in the same manner as above. The measurement results are shown in the "After heat treatment" section of "Peel strength (kgf / cm)" in Table 1.

[0099] Furthermore, the deterioration rate (%) was calculated using the following formula, and the results are shown in the "Deterioration rate (%)" column in Table 1. Deterioration rate (%) = [Peel strength after heat treatment (kgf / cm)] / [Initial peel strength (kgf / cm)] × 100

[0100] (Evaluation 11: Measurement of Transmission Loss) A 100 μm thick resin substrate (product name: ADFLEMA, Dk: 2.3, Df: 0.0012, manufactured by Namics Corporation) was thermocompression bonded to the treated surface of the copper members of Examples 1 to 10 and Comparative Examples 1 to 4 by holding it at 200°C and 1 MPa for 120 minutes using a vacuum press to prepare a measurement sample. To evaluate transmission loss, a known stripline resonator method suitable for measurement in the 10 MHz to 95 GHz band was used, and measurements were made from 10 MHz to 95 GHz in 10 MHz steps. Specifically, the S21 parameter was measured under the following conditions without a coverlay film.

[0101] Measurement conditions: Microstrip structure Resin substrate: ADFLEMA (Dk: 2.3, Df: 0.0012, manufactured by Namics Corporation) Circuit length: 100 mm Conductor width: 285 μm Conductor thickness: 28 μm Substrate thickness: 100 μm Characteristic impedance: 50 Ω

[0102] Based on the S21 transmission loss value at 95 GHz measured by the above method, the difference in transmission loss compared to the copper member of Comparative Example 1 (copper foil that was substantially not surface-treated) was evaluated as follows. The numerical ranges in the evaluation are absolute values. The results are shown in the "Difference from untreated foil" under "Transmission loss" in Table 1. 2% or less: ◎ More than 2% and 5% or less: ◯ More than 5% and 10% or less: △ More than 10%: X

[0103]

[0104] The copper member of the present invention has excellent adhesion to resin substrates and heat resistance reliability.

[0105] REFERENCE SIGNS LIST 1 Copper member 2 Copper material 3 Copper oxide layer 4 Protrusion 5 Metal layer other than copper 10 Laminate 11 Copper member 12 Resin substrate

Claims

1. A copper member comprising a copper material and protrusions formed on a surface of the copper material, the protrusions containing copper and / or copper oxide, and satisfying at least one selected from the group consisting of the following (1) to (3): (1) Using a nanoindenter, an indenter is pressed into the surface of the copper member at a load of 0.1 mN / s in an atmosphere of 30°C. The load is released when the indentation depth reaches 10 nm. The distance the indenter has been pressed 5 seconds after the load is released is defined as h (nm). The indentation creep (C) of the copper member calculated by [(h-10) / 10]×100 is calculated as follows: ＩＴ ) is 80% or more. The reference point for the depth is the surface of the copper member. (2) Using a nanoindenter, the indenter is pressed into the surface of the copper member at a pressing speed of 0.1 mN / s in an atmosphere of 30° C. The load is removed when the pressing depth reaches 10 nm. From the graph of the applied load and the indentation depth (displacement) obtained by the above operation, the indentation hardness (GPa) of the copper member calculated by an analysis method conforming to ISO 14577-1 is 1 or less. The maximum indentation depth (hmax) used to calculate the indentation hardness (GPa) was obtained when fitting the unloading curve at F = 20% and 95%. The reference point for the depth was the surface of the copper member. (3) Using a nanoindenter, the indenter is pressed into the surface of the copper member under an atmosphere of 30 ° C., with a load of 0.1 mN / s applied at an indentation speed. The load is removed when the indentation depth reaches 10 nm. From the graph of the applied load and the indentation depth (displacement) obtained by the above operation, the indentation elastic modulus (GPa) of the copper member calculated by an analysis method conforming to ISO 14577-1 is 120 or less. The maximum indentation depth (hmax) used to calculate the indentation elastic modulus (GPa) was that obtained when fitting the unloading curve at F = 20% and 95%. The reference point for the depth was the surface of the copper member.

2. The copper member according to claim 1, having a copper oxide layer formed on the surface.

3. The copper member according to claim 2, wherein a metal layer other than copper is formed on a part or all of the surface of the copper oxide layer.

4. The copper member according to claim 3, wherein the metal layer other than copper includes a magnetic metal and a non-magnetic metal other than copper.

Images