TWI829898B - Method for manufacturing metal components with metal layers - Google Patents

Abstract

The object of the present invention is to provide a novel method for manufacturing metal components with metal layers. The manufacturing method of a metal component with a metal layer in this case includes a first step and a second step. The first step is to form an oxidation layer with an average thickness of 400 nm or less and a fine uneven shape on at least part of the surface of the metal component through an oxidation treatment. The second step is to form the metal layer on the oxide layer by electroplating.

Description

Method for manufacturing metal components with metal layers

The present invention relates to a method of manufacturing a metal member having a metal layer.

Copper foil used for printed wiring boards requires good adhesion to resin. In order to improve this adhesion, the surface of the copper foil has been roughened by etching, which is a method of improving mechanical adhesion through the so-called anchor effect. However, from the viewpoint of high density of printed wiring boards or transmission loss in high frequency bands, the copper foil surface also needs to be planarized. In order to satisfy the above-mentioned contradictory requirements, a copper surface treatment method that performs an oxidation step, a reduction step, and the like has been developed (see Patent Document 1). According to this method, the copper foil is pre-treated and immersed in a solution containing an oxidizing agent to oxidize the surface of the copper foil to form irregularities of copper oxide (CuO), and then immersed in a solution containing a reducing agent to reduce the copper oxide and partially form Cuprous oxide (Cu ₂ O), thereby adjusting the unevenness of the surface. In addition, a method of adding interface active molecules in the oxidation step has been developed as a method for improving the adhesion of copper foil treatment by oxidation and/or reduction (see Patent Document 2), and the use of aminothiazole-based compounds after the reduction step, etc. A method of forming a protective film on the surface of copper foil (see Patent Document 3).

Generally speaking, metal oxides have a greater resistance than unoxidized metals. For example, the resistivity of pure copper is 1.7×10 ^-8 (Ωm). Compared with this, the resistivity of copper oxide is 1~10(Ωm), and the resistivity of cuprous oxide is 1×10 ⁶ ~1×10 ⁷ (Ωm), the conductivity of copper oxide and cuprous oxide is worse than that of pure copper. Therefore, when oxidation treatment is used to roughen the surface of copper foil, the plating method does not use electroplating, but uses electroless plating (also called electroless plating) that can handle even when the conductivity is poor (refer to patent documents 4). On the other hand, when copper particles are adhered to copper foil by electroplating to roughen the surface of the copper foil, since there are no oxides on the surface of the copper foil, the roughening treatment of the copper foil can be completed by performing electroplating again. The surface is plated with other metals (Patent Documents 5 and 6).

The plating film is required to be able to withstand use and the environment, and to have adhesion to a level that does not hinder practical use. As a means, known methods include removing the oxide layer on the metal surface to strengthen the metal bond and roughening the surface to disperse stress and ensure adhesion (Non-Patent Document 1).

Patent document 1 is International Publication No. WO2014/126193; Patent document 2 is Japanese Patent Application Publication No. 2013-534054; Patent document 3 is Japanese Patent Application Publication No. 8-97559; Patent document 4 is Japanese Patent Application Publication No. 2000-151096 ; Patent document 5 is Japanese Patent No. 5764700; Patent document 6 is Japanese Patent No. 4948579.

Non-patent document 1 is "Adhesion of plating film and its improvement method" written by Morikawa Mu, Nakade Takuo, and Yokoi Masayuki.

The object of the present invention is to provide a novel method for manufacturing metal components with metal layers.

Generally speaking, it is known that the adhesion between metal and metal-plated layer is ensured by metal bonds. If there is an oxide layer at the interface of the metal, it will hinder the metal bond between the metal and the metal-plated layer, making it difficult to obtain tightness. Attachment. Therefore, usually when there is an oxide layer on the metal surface, due to reasons such as poor electrical conductivity and difficulty in obtaining adhesion between the metal foil and the metallized layer, electroplating is not performed directly, but is first removed by acid treatment, etc. After oxidation. In addition, if the metal is smooth, stress is transmitted to the interface between the metal and the metal plating and is concentrated, easily causing interface peeling. On the other hand, unlike a smooth surface, the uneven interface does not have a clear surface for transmitting stress. When energy is transferred, it is considered that part of it deforms the plated metal or the metal, thereby consuming energy and improving the adhesion. As a result of intensive research by the present inventors, it was found that by making the oxide layer have an average thickness of 400 nm or less, electrical conductivity will be poor and metal bonds will be hindered. The influence is kept to a minimum, and by having a fine concave and convex shape, the adhesion between the metal component and the plated metal can be improved by the anchoring effect, and the metal can be successfully electroplated on the surface of the oxide layer.

Therefore, the main aspects of the present invention are as follows:

[1] A method of manufacturing a metal member with a metal layer, including a first step and a second step. The first step is to form an average thickness of 400 nm or less and fine unevenness on at least part of the surface of the metal member through oxidation treatment. The second step is to form the metal layer on the oxide layer by electroplating.

[2] The method for manufacturing a metal member having a metal layer according to [1], wherein the current density of the electrolytic treatment in the second step is 5 A/dm ² or less.

[3] The method of manufacturing a metal member having a metal layer according to [1] or [2], wherein the metal member is a copper member and the metal layer is a layer of a metal other than copper.

[4] The method of manufacturing a metal member with a metal layer according to [3], wherein the metal other than copper is selected from tin, silver, zinc, aluminum, titanium, bismuth, chromium, iron, cobalt, nickel, palladium, At least one metal from the group consisting of gold and platinum.

[5] The method for manufacturing a metal member having a metal layer according to any one of [1] to [4], wherein the Ra of the surface on which the oxide layer is formed after the first step is 0.035 μm or more and 0.115 μm. the following.

[6] The method for manufacturing a metal member having a metal layer according to any one of [1] to [5], wherein the Rz of the surface on which the oxide layer is formed after the first step is 0.25 μm or more and 1.00 μm. the following.

[7] The method for manufacturing a metal member having a metal layer according to any one of [1] to [6], wherein the average thickness of the metal layer in the vertical direction is 20 nm or more and 80 nm or less.

[8] The method of manufacturing a metal member having a metal layer according to any one of [1] to [7], wherein Ra of the surface on which the metal layer is formed after the second step is 0.02 μm or more and 0.20 μm or less. Down.

[9] The method for manufacturing a metal member having a metal layer according to any one of [1] to [8], wherein Rz of the surface on which the metal layer is formed after the second step is 0.2 μm or more and 1.4 μm or less. .

[10] The method for manufacturing a metal member with a metal layer according to any one of [1] to [9], wherein the discoloration resistance ΔE*ab of the surface on which the metal layer is formed after the second step is 15 the following.

[Figure 1] Cross-sectional images of Example 1 and Comparative Example 1 after oxidation treatment observed with a scanning electron microscope (SEM) (magnification: 50,000 times).

[Figure 2] A graph showing the relationship between the thickness of the oxide layer and the peel strength in Example (○) and Comparative Example (◆).

[Figure 3] A graph showing the relationship between the thickness of the oxide layer and the heat resistance degradation rate in Example (○) and Comparative Example (◆).

[Figure 4] The relationship between the thickness of the oxide layer and the heat discoloration resistance ΔE*ab in Example (○) and Comparative Example (◆).

Preferred embodiments of the present invention will be described in detail below using additional drawings, but are not limited thereto. Furthermore, from the description of this specification, a person with ordinary knowledge in the technical field to which the invention belongs will understand the purpose, characteristics, advantages and concepts of the present invention, and a person with ordinary knowledge in the technical field to which the invention belongs can easily reproduce it based on the description of this specification. invention. The embodiments and specific examples of the invention described below represent preferred embodiments of the invention and are used for illustration and explanation and are not intended to limit the invention. It would be obvious to a person with ordinary knowledge in the technical field to which the invention belongs. Various modifications can be made based on the description of this specification within the intention and scope of the present invention.

Method for manufacturing a metal component with a metal layer: One embodiment of the present invention is a method for manufacturing a metal component with a metal layer, including a first step and a second step. The first step is to oxidize the metal component on the metal component. An oxide layer with an average thickness of less than 400 nm and a fine uneven shape is formed on the surface. The second step is to form the metal layer on the oxide layer by electroplating. The metal member is a material containing metal as a part of the structure. The metal contained is not particularly limited, and examples thereof include titanium, niobium, stainless steel, tantalum, nickel, zinc, aluminum, copper, silver, gold, platinum, and the like. The metal member may be a member made of copper or a member made of a substance other than copper, or a member made of a substance other than copper may have a copper layer on its surface, or may be copper plated. The shape of this member is not particularly limited. For example, it can be in the form of foil, granular, or powder. The metal member also includes copper foil such as electrolytic copper foil, rolled copper foil, and copper foil with a carrier, copper particles, and copper as the main component. pellets, copper wires, copper plates, copper lead frames, etc., but are not limited to these. The thickness of the metal member is not particularly limited, but a thickness that can be electroplated is preferred. It is preferably 0.1 μm or more and 100 μm or less, and more preferably 0.5 μm or more and 50 μm or less.

First, in the first step, the metal component is oxidized to form an oxide layer on the surface of the metal component. The formation method is not particularly limited and may be formed using an oxidizing agent, heat treatment or anodizing. This oxidation step does not need to be preceded by a roughening step such as etching, but may be performed. It can be degreased and cleaned, or it can be treated with an alkali to prevent acids from being carried into the oxidation step. The method of alkali treatment is not particularly limited. It is better to use an alkaline aqueous solution of 0.1~10g/L, and more preferably an alkaline aqueous solution of 1~2g/L. The alkaline aqueous solution, such as sodium hydroxide aqueous solution, is treated at 30~50°C for 0.5 ~2 minutes is enough.

The oxidizing agent is not particularly limited, and for example, aqueous solutions such as sodium chlorite, sodium hypochlorite, potassium chlorate, potassium perchlorate, and potassium persulfate can be used. Various additives (for example, phosphates such as trisodium phosphate dodecahydrate) or surface-active molecules can be added to the oxidizing agent. Examples of surface-active molecules include rhodopsin, rhodopsin macrocycle, expanded rhodopsin, contracted cyclic rhodopsin, linear rhodopsin polymers, rhodopsin sandwich coordination complexes, rhodopsin Mass array, silane, tetraorgano-silane, aminoethyl-aminopropyl-trimethoxysilane, (3-aminopropyl)trimethoxysilane, (1-[3-(trimethoxysilane (1-[3-(Trimethoxysilyl)propyl]urea), (3-aminopropyl)triethoxysilane, (3-epoxypropyloxypropyl)trimethoxysilane , (3-chloropropyl)trimethoxysilane, (3-epoxypropyloxypropyl)trimethoxysilane, dimethyldichlorosilane, 3-(trimethoxysilyl)propylmethacrylic acid Ester, ethyltriethyloxysilane, triethoxy(isobutyl)silane, triethoxy(octyl)silane, ginseng(2-methoxyethoxy)(vinyl)silane, chlorine Trimethylsilane, methyltrichlorosilane, silicon tetrachloride, tetraethoxysilane, phenyltrimethoxysilane, chlorotriethoxysilane, vinyl-trimethoxysilane, amines, sugars, etc. For example, the oxidation treatment liquid may contain sodium chlorite of 30 g/L to 200 g/L, sodium hydroxide of 40 g/L or less, potassium hydroxide of 8 g/L to 40 g/L, and potassium hydroxide of 10 g/L or less. Aqueous solution of 3-epoxypropyloxypropyltrimethoxysilane.

The oxidation reaction conditions are not particularly limited. The liquid temperature of the oxidizing agent is preferably 40 to 95°C, more preferably 45 to 80°C. The reaction time is preferably 0.5 to 30 minutes, more preferably 1 to 10 minutes.

In the first step, the oxide layer formed by the oxidation treatment can be dissolved with a dissolving agent to adjust the uneven portions on the surface of the oxide layer.

The dissolving agent used in this step is not particularly limited. Preferably it is a chelating agent, especially a biodegradable chelating agent. Examples include ethylenediaminetetraacetic acid, dihydroxyethylglycine, and L-glutamic acid diacetic acid. Tetrasodium, ethylenediamine-N,N'-disuccinic acid, sodium 3-hydroxy-2,2'-iminodisuccinate, trisodium methylglycine diacetate, tetrasodium aspartic acid diacetate Sodium, disodium N-(2-hydroxyethyl)iminodiacetate, sodium gluconate, etc.

The pH value of the dissolving agent is not particularly limited, but it is preferably alkaline, more preferably pH 8.0~10.5, further preferably pH 9.0~10.5, further preferably pH 9.8~10.2.

In the first step, the thickness of the oxide layer is made to be 400 nm or less on average. The average thickness is preferably 200 nm or less, more preferably 160 nm or less, or 90 nm or less. And, oxidation The thickness of the physical layer is preferably an average of 20 nm or more, more preferably an average of 30 nm or more, and still more preferably an average of 40 nm or more. In addition, the proportion of the area where the thickness of the oxide layer is 400 nm or less is not particularly limited, but more preferably 50% or more of the area is 400 nm or less, more preferably 70% or more of the area is 400 nm or less, and more preferably 90% or more of the area is 400 nm. below, more preferably, more than 95% of the area is 400 nm or less, and still more preferably, almost 100% of the area is 400 nm or less. The thickness ratio of the oxide layer can be calculated from 10 measurement points in an area of 10×10 cm, for example, by the continuous electrochemical reduction method (SERA).

The arithmetic mean roughness (Ra) of copper oxide is preferably 0.01 μm or more, more preferably 0.04 μm or more, and preferably 0.20 μm or less, more preferably 0.060 μm or less. The maximum height roughness (Rz) of copper oxide is preferably 0.2 μm or more, more preferably 0.4 μm or more, and preferably 1.0 μm or less, more preferably 0.50 μm or less. Here, the maximum height roughness (Rz) represents the sum of the maximum value of the peak height Zp and the maximum value of the valley depth Zv of the contour curve (y=Z(x)) in the reference length l. The arithmetic mean roughness (Ra) represents the average value of the absolute values of Z(x) (that is, peak height and valley depth) in the profile curve (y=Z(x)) expressed by the following formula in the reference length l.

Surface roughness Ra and Rz are calculated according to the method specified in JIS B 0601:2000 (based on international standard ISO4287-1997).

Then, in the second step, the oxide layer formed in the first step is electroplated to form a metal layer. The metal used for electroplating is not particularly limited as long as it is different from the metal of the metal component, but is preferably selected from tin, silver, zinc, aluminum, titanium, bismuth, chromium, iron, cobalt, nickel, palladium, gold and platinum. At least one metal from the group or their alloys. Especially when the metal member is copper, in order to have heat resistance, it is preferable to use a metal with higher heat resistance than copper, such as nickel, palladium, gold, platinum or alloys thereof.

The average thickness of the metal layer formed by electroplating in the vertical direction is not particularly limited, but is preferably 10 nm or more, more preferably 15 nm or more, and still more preferably 20 nm or more. Furthermore, the thickness is preferably 100 nm or less, more preferably 70 nm or less, and still more preferably 50 nm or less. Alternatively, the metal amount of the metal layer formed by electroplating, expressed in terms of metal weight per unit area, is preferably 15 μg/cm ² or more, more preferably 18 μg/cm ² or more, and still more preferably 20 μg/cm ² or more. In addition, it is preferably 100 μg/cm ² or less, more preferably 80 μg/cm ² or less, and still more preferably 50 μg/cm ² or less. The average thickness of the metal layer in the vertical direction can be calculated by dissolving the metal forming the metal layer in an acidic solution, measuring the amount of metal by ICP analysis, and dividing the measured amount by the area of the metal member. Alternatively, it can also be calculated by dissolving the metal member having the metal layer itself and detecting and measuring only the amount of metal forming the metal layer.

Electroplating requires an electric charge to reduce a part of the oxide of the oxide layer. Therefore, for example, when plating copper foil with nickel, in order to keep the thickness within a preferred range, it is better to give the unit area of the metal member processed by electroplating Charge above 15C/dm ² ~ below 90C/dm ² . Moreover, the current density is preferably 5 A/dm ² or less. If the current density is too high, plating will be concentrated on the convex parts, making it difficult to achieve uniform plating. Furthermore, the current during plating can be varied until a portion of the oxide of the oxide layer is reduced. In addition, it is appropriately adjusted to the specified thickness by plating the metal. Examples of nickel plating and nickel alloy plating include pure nickel, nickel-copper alloy, nickel-chromium alloy, nickel-cobalt alloy, nickel-zinc alloy, nickel-manganese alloy, nickel-lead alloy, nickel-phosphorus alloy, and the like. Examples of the supplying agent for plating ions include nickel sulfate, nickel sulfamate, nickel chloride, nickel bromide, zinc oxide, zinc chloride, palladium diamine dichloride, ferric sulfate, ferric chloride, anhydrous chromic acid, Chromium chloride, sodium chromium sulfate, copper sulfate, copper pyrophosphate, cobalt sulfate, manganese sulfate, sodium hypophosphite, etc. Other additives including pH buffers or gloss agents may be used, such as boric acid, nickel acetate, citric acid, sodium citrate, ammonium citrate, potassium formate, malic acid, sodium malate, sodium hydroxide, potassium hydroxide, and sodium carbonate. , ammonium chloride, sodium cyanide, potassium sodium tartrate, potassium thiocyanate, sulfuric acid, hydrochloric acid, potassium chloride, ammonium sulfate, ammonium chloride, potassium sulfate, sodium sulfate, sodium thiocyanate, sodium thiosulfate, potassium bromate , potassium pyrophosphate, ethylenediamine, nickel ammonium sulfate, sodium thiosulfate, fluorosilicic acid, sodium fluorosilicate, strontium sulfate, cresolsulfonic acid, β-naphthol, saccharin, 1,3,6-naphthalene trisulfate Sulfonic acid, sodium naphthalene disulfonate, sodium naphthalene trisulfonate, sulfonamide, sulfinic acid, 1,4-butynediol, coumarin, sodium lauryl sulfate, etc. The preferred bath composition for nickel plating can include, for example, nickel sulfate (above 100g/L~350g/L), nickel sulfamate (above 100g/L~600g/L), nickel chloride (above 0g/L~ 300g/L or less) and mixtures thereof may also contain sodium citrate (0g/L or more to 100g/L or less) or boric acid (0g/L or more to 60g/L or less) as additives.

The arithmetic mean roughness (Ra) of the surface after electrolytic treatment is preferably 0.02 μm or more, more preferably 0.04 μm or more, and preferably 0.20 μm or less, more preferably 0.060 μm or less. The maximum height roughness (Rz) of the surface after electrolytic treatment is preferably 0.2 μm or more, more preferably 0.4 μm or more, and preferably 1.4 μm or less, more preferably 0.50 μm or less. In addition, the change in surface roughness expressed by the ratio of Ra after oxidation treatment to Ra after metal plating (Ra after oxidation treatment/Ra after metal plating treatment) is preferably 0.7 or more and 1.3 or less. The ratio of Rz to Rz after metal plating (Rz after oxidation treatment/Rz after metal plating and coupling treatment) is preferably from 0.8 to 1.2. The closer this ratio is to 1, the more uniform the thickness of the metal layer formed by electroplating is.

In this way, by performing the first step and the second step on the metal member, a metal member having a metal layer can be produced. The metal member having a metal layer produced by this production method has excellent adhesion to resin and excellent heat resistance.

In one embodiment of the present invention, when the heat resistance of the metal member with the metal layer manufactured by this manufacturing method is evaluated by color change ΔE*ab, it is 15 or less, preferably 10 or less. The color change ΔE*ab can be measured by conventional methods. For example, after measuring the color difference (L*, a*, b*) of the metal member before heat treatment, place it in an oven at 225°C for 30 minutes, measure the color difference of the metal member after heat treatment, and calculate ΔE*ab.

In addition, the metal member having the metal layer produced by this manufacturing method can be subjected to coupling treatment using a silane coupling agent or the like or anti-rust treatment using benzotriazoles or the like.

Furthermore, the metal member having the metal layer manufactured by this manufacturing method can be laminated. Grease base material to make laminates. In one embodiment of the present invention, the deterioration rate of the produced laminate in the heat resistance test is 45% or less, preferably 30% or less, 20% or less, or 10% or less. The deterioration rate of the heat resistance test can be measured by conventional methods. For example, it can be expressed as a ratio obtained by measuring the peel strength before and after the heat resistance test and dividing the difference in peel strength by the peel strength before the heat resistance test.

Utilization method of metal member with metal layer: The metal member with metal layer produced by the manufacturing method of the present invention, when the metal member is copper, can be used as copper foil used in printed wiring boards and copper in substrate wiring. wire, copper foil for LIB negative electrode current collector, etc. For example, the surface of the copper foil used for printed wiring boards is roughened by the manufacturing method of the present invention, and is bonded with resin to form a layer, thereby producing a laminate for use in manufacturing printed wiring boards. The type of resin in this case is not particularly limited, but is preferably polyphenylene ether, epoxy resin, PPO, PBO, PTFE, LCP or TPPI. For another example, by roughening the copper foil used for the LIB negative electrode current collector by the manufacturing method of the present invention, the adhesion between the copper foil and the negative electrode material can be improved, and a good lithium ion battery with less capacity degradation can be obtained. The negative electrode current collector used in lithium ion batteries can be manufactured according to conventional methods. For example, a negative electrode material containing a carbon-based active material is prepared and dispersed in a solvent or water to form an active material slurry. This active material slurry is applied to the copper foil roughened by the manufacturing method of the present invention, and then the solvent or water is evaporated and dried. After that, it is pressed and dried again to form the negative electrode current collector into the desired shape. In addition, the negative electrode material may also include silicon or silicon compounds, germanium, tin or lead, etc., which have a larger theoretical capacity than the carbon-based active material. In addition, as the electrolyte, in addition to an organic electrolyte solution in which a lithium salt is dissolved in an organic solvent, a polymer made of polyethylene glycol, polyvinylidene fluoride, or the like can also be used. In addition to being used in lithium-ion batteries, the copper foil whose surface is roughened by the manufacturing method of the present invention can also be used in lithium-ion polymer batteries.

(Examples) <1. Manufacturing a metal member with a metal layer>: Examples 1 to 9 and Comparative Examples 1 to 4 used DR-WS (manufactured by Furukawa Electric Co., Ltd., thickness 18 μm) copper foil. In addition, in the examples and comparative examples, several test pieces were produced under the same conditions.

(1) Pretreatment: [Alkali degreasing treatment] Immerse the copper foil in a liquid temperature of 50°C and 40g/L After 1 minute in the sodium hydroxide aqueous solution, wash with water.

[Pickling treatment] The copper foil that has been subjected to alkali degreasing treatment is immersed in a 10% by weight sulfuric acid aqueous solution with a liquid temperature of 25°C for 2 minutes, and then washed with water.

[Pre-soaking treatment] Immerse the pickled copper foil in a pre-soaking solution with a liquid temperature of 40°C and sodium hydroxide (NaOH) 1.2g/L for 1 minute.

(2) Oxidation treatment (first step): The alkali-treated copper foil is oxidized using an oxidation treatment aqueous solution according to the conditions described in Table 1. After these treatments, the copper foil is washed with water. The evaluation method is described later in <2. Evaluation of Samples After Oxidation Treatment>. As shown in Figure 1, the shape or size of the unevenness on the surface of the copper oxide layer greatly changes depending on the thickness of the copper oxide layer.

(3) Electroplating treatment: The oxidized copper foil is subjected to electroplating treatment according to the conditions described in Table 1. In Comparative Examples 2 and 3, no nickel was precipitated even after electroplating for 3 minutes.

(4) Coupling treatment: Coupling treatment is performed on the electroplated copper foil according to the conditions recorded in Table 1.

<2. Evaluation of samples after oxidation treatment>: (1) Measurement of copper oxide thickness: Use QC-100 (manufactured by ECI) and measure the thickness of the copper foil surface by the continuous electrochemical reduction method (SERA) using the following electrolyte solution The thickness of copper oxide.

Electrolyte (pH=8.4)

Boric acid 6.18g/L; sodium tetraborate 9.55g/L

Specifically, when using a gasket with a diameter of 0.32cm and using the above-mentioned electrolyte at a current density of 90μA/ ^cm2 , the potential was judged to be the peak of copper oxide (CuO) from more than -0.85V to -0.6V.

(2) Calculate Ra and Rz: Use a conjugate focal scanning electron microscope OPTELICS H1200 (manufactured by Lasertec Co., Ltd.) to measure the surface shape of the oxidized copper foil, and calculate Ra according to the method specified in JIS B 0601:2001. and Rz. Measurement conditions: scanning width is 100 μm, scanning type is Area, light source is blue light, and Cut-off value is 1/5. With objective lens x100, The eyepiece x14, the digital zoom x1, and the Z pitch were set to 10 nm. Data were obtained at three positions, and the average value was calculated as Ra and Rz for each example and each comparative example. Example 6 and Comparative Examples 1 to 3 cannot be calculated, so they are recorded as N.D. in the table.

<3. Evaluation of samples after electroplating and coupling treatment> (1) Calculate the amount of nickel: The method of measuring the average thickness of nickel in the vertical direction, for example, dissolve the copper component in 12% nitric acid, and use the resulting liquid with an ICP emission spectrometer. 5100 SVDV ICP-OES (manufactured by Agilent Technologies) measures the concentration of metal components and calculates the thickness of the layered metal layer by considering the metal density and the surface area of the metal layer.

(2) Calculate Ra and Rz: Use a conjugate focal scanning electron microscope OPTELICS H1200 (manufactured by Lasertec Co., Ltd.) to measure the surface shape of the copper foil after electroplating and coupling treatment, according to the method specified in JIS B 0601:2001 Calculate Ra and Rz. Measurement conditions: scanning width is 100 μm, scanning type is Area, light source is blue light, and Cut-off value is 1/5. Connect the objective lens x100, the eyepiece x14, the digital zoom x1, and set the Z spacing to 10nm, and obtain the data of three positions. Ra and Rz are the average values of the three positions.

(3) Measurement of the peel strength of the laminated body before and after heat treatment: For the copper foil after electroplating and coupling treatment, a laminated body was produced and the peel strength before and after heat treatment was measured. In addition, when measuring the peeling strength, the peeling surface was visually confirmed to confirm whether the plating layer was peeled off. First, for each copper foil, MEGTRON6 (manufactured by Panasonic Corporation) containing PPE as a resin was heat-pressed and laminated in a vacuum under the conditions of a pressurizing pressure of 2.9 MPa, a temperature of 210° C., and a pressurizing time of 120 minutes, and two sheets each were obtained. Measure the sample. Each measurement sample was subjected to heat-resistant treatment (177° C., 10 days) in order to determine its heat resistance. Thereafter, a 90° peel test (Japanese Industrial Standard (JIS) C5016) was performed on each of the heat-treated samples and the non-heat-treated samples to determine the peel strength (kgf/cm). The heat resistance deterioration rate is calculated as a ratio obtained by dividing the measured difference in peel strength before and after the heat resistance test by the peel strength before the heat resistance test. The above uses MEGTRON6 as the prepreg, However, when using other commercially available prepregs such as MEGTRON4, almost no deterioration caused by copper foil occurs, and the same adhesion before and after heat treatment can be obtained.

(4) Calculate the color change of copper foil before and after heat treatment: The heat resistance of copper foil after electroplating and coupling treatment is also evaluated by color change. Specifically, heat treatment was performed in an oven at 225° C. for 30 minutes, and the color change before and after was evaluated by ΔE*ab. After measuring the color difference (L*, a*, b*) of the copper foil before heat treatment, place it in an oven at 225°C for 30 minutes, measure the color difference of the copper foil after heat treatment, and calculate ΔE*ab according to the following formula.

△E*ab=[(△L ^* ) ² +(△a ^* ) ² +(△b ^* ) ² ] ^1/2

Table 1

In this way, when the thickness of copper oxide is 502 nm or more, electroplating cannot be performed (Comparative Example 2, Comparative Example 3). Furthermore, even if the thickness of copper oxide is electroplatable, when the thickness of copper oxide is thicker than 400 nm, adhesion between the plating layer and the metal member cannot be obtained and peeling occurs (Comparative Example 1). In comparison, in Examples 1 to 9 in which the thickness of the copper oxide was 400 nm or less, adhesion between the plating layer and the metal member was obtained, and adhesion to the resin and heat resistance were excellent. In addition, when the current density is greater than 5A/ ^dm2 , the heat resistance is low (Comparative Example 4). In contrast, in Examples 1 to 9 where the current density is less than 5A/ ^dm2 , the adhesion to the resin and the heat resistance are Excellent.

Industrial Applicability: According to the present invention, a novel method for manufacturing a metal member having a metal layer can be provided.

Claims (10)

A method of manufacturing a metal member with a metal layer, including a first step and a second step. The first step is to form an oxidation layer with an average thickness of 400 nm or less and a fine uneven shape on at least part of the surface of the metal member through an oxidation treatment. The second step is to form the metal layer on the oxide layer by electroplating. The method for manufacturing a metal component with a metal layer as claimed in claim 1, wherein the current density of the electrolytic treatment in the second step is 5 A/dm ² or less. The method for manufacturing a metal component with a metal layer as claimed in claim 1 or 2, wherein the metal component is a copper component and the metal layer is a layer of a metal other than copper. The method of manufacturing a metal component with a metal layer according to claim 3, wherein the metal other than copper is selected from the group consisting of tin, silver, zinc, aluminum, titanium, bismuth, chromium, iron, cobalt, nickel, palladium, gold and platinum. At least one metal in the group. The method of manufacturing a metal member with a metal layer as claimed in claim 1 or 2, wherein the Ra of the surface on which the oxide layer is formed after the first step is 0.035 μm or more and 0.115 μm or less. The method for manufacturing a metal member with a metal layer as claimed in claim 1 or 2, wherein the Rz of the surface on which the oxide layer is formed after the first step is 0.25 μm or more and 1.00 μm or less. The method for manufacturing a metal component with a metal layer as claimed in claim 1 or 2, wherein the average thickness of the metal layer in the vertical direction is 20 nm or more and 80 nm or less. The manufacturing method of a metal member with a metal layer as claimed in claim 1 or 2, wherein the Ra of the surface on which the metal layer is formed after the second step is 0.02 μm or more and 0.20 μm or less. The manufacturing method of a metal member with a metal layer as claimed in claim 1 or 2, wherein the Rz of the surface on which the metal layer is formed after the second step is 0.2 μm or more and 1.4 μm or less. The manufacturing method of a metal component with a metal layer as claimed in claim 1 or 2, wherein, The heat-resistant discoloration ΔE*ab of the surface on which the metal layer is formed after the second step is 15 or less.