TWI768140B - Object having copper surface after roughening treatment, method for roughening treatment of copper surface, method for producing object, method for producing laminated board, and method for producing printed wiring board - Google Patents

Abstract

The object of the present invention is to provide an object with a roughened copper surface. One embodiment of the present invention is an object having a surface covered with copper having a thickness of 6 nm or more, wherein at least a part of the copper surface has a convex portion, the surface of the convex portion contains copper oxide, and the interior of the convex portion contains copper , there are on average ₅ or more protrusions with a height of 50 nm or more per 3.8 μm , and the average length of the protrusions is 500 nm or less.

Description

Objects with roughened copper surfaces, roughened copper surfaces Method, method for manufacturing object, method for manufacturing laminate, and method for manufacturing printed wiring board

The present invention relates to an object having a roughened copper surface.

Copper has a variety of uses, such as copper foil for printed wiring boards, copper wires for wiring on substrates, copper foil for LIB negative electrode current collectors, and the like.

For example, a copper foil used for a printed wiring board is required to have adhesion to resin. In order to improve this adhesiveness, the method of roughening the surface of copper foil by etching etc. conventionally, and improving the physical adhesive force has been known. However, with the increase in density of printed wiring boards, the surface of the copper foil is required to be flattened. In order to satisfy the above-mentioned opposite requirements, a copper surface treatment method for performing an oxidation step, a reduction step, and the like has been developed (WO2014/126193 Publication No.). According to this method, the copper foil is pretreated and dipped in a potion containing an oxidizing agent to oxidize the surface of the copper foil to form unevenness of copper oxide, and then immersed in a potion containing a reducing agent to reduce the copper oxide, thereby adjusting the unevenness of the surface to level the surface roughness. In addition, a method of adding interfacial active molecules in the oxidation step has been developed as a method for improving adhesion by copper foil treatment by redox (JP 2013-534054 A), and an aminothiazole-based compound is used after the reduction step. etc. A method of forming a protective film on the surface of a copper foil (Japanese Patent Laid-Open No. 8-97559).

In addition, in the LIB negative electrode current collector, if a large-capacity active material is used for high output and high energy density, the volume expansion rate of the active material during charging and discharging increases. Therefore, when charging and discharging are repeated, the binding material connecting the active material and the current collector is broken, or the binding material is decomposed from the active material. The material interface and the current collector interface are peeled off, and the cycle characteristics are deteriorated. In order to prevent the above situation, there is an invention that increases the amount of the binder in the copper foil to improve the adhesion between the copper foil and the negative electrode mixture layer (Japanese Patent Laid-Open No. 10-284059).

The object of the present invention is to provide an object with a roughened copper surface.

An embodiment of the present invention is an object having a roughened copper surface, having a surface covered with copper with a thickness of 6 nm or more, wherein at least a part of the copper surface has a convex portion, and the surface of the convex portion contains oxide Copper, the inside of the convex portion contains copper, and in the cross section, there are on average 5 or more convex portions with a height of 50 nm or more per 3.8 μm , and the average length of the convex portions is 500 nm or less, and the depth is 6 nm (in terms of SiO2) The Cu/O content ratio is 5 or less, and in the cross-sectional image of the scanning electron microscope, for the line connecting the minimum points of the concave parts on both sides of the convex part, the distance between the midpoint of the line and the maximum point of the convex part can be determined. It was measured as the height of this convex part. The object can be copper foil, copper particles, copper powder or copper-plated objects. The thickness of the layer including the copper oxide may be 8-50 nm.

Another embodiment of the present invention is a method for roughening a copper surface, comprising: a first step of oxidizing the copper surface; and a second step of dissolving the oxidized copper surface. Alkaline treatment using an aqueous alkaline solution may be performed prior to the first step. The copper surface can be oxidized by an oxidizing agent in the first step. The oxidized copper surface can be dissolved by a dissolving agent in the second step. The pH value of the dissolving agent can be pH9.0~14.0. The oxidized copper surface can be dissolved so that the dissolution rate of copper oxide produced by oxidation of the copper surface is 35-99%, and the thickness of the oxide film measured by SERA is 4-150 nm.

Another embodiment of the present invention is a method for producing any one of the objects described above, including the step of treating the copper on the surface of the object by the roughening treatment method described above.

Another embodiment of the present invention is a method of manufacturing a laminate, a method of manufacturing a laminate of copper foil and resin, wherein the copper foil is any one of the above-mentioned objects, and the manufacturing method includes the object The step of adhering the body and the resin into a layer. The resin may be polyphenylene ether.

Another embodiment of the present invention is a method for manufacturing a printed wiring board, which includes a laminate manufacturing step of any one of the above-described methods for manufacturing a laminate.

[FIGURE 1] In Example 1 of this invention, the ratio of each element in the depth from the copper foil surface after roughening process.

[FIG. 2] In Example 1 of this invention, the photograph of the surface and the cross section of the copper foil after roughening treatment was taken with a scanning electron microscope (SEM).

[FIG. 3] In Example 1 of the present invention, a calculation method for calculating the height and the number of convex portions in a photograph taken by an SEM.

[FIG. 4] In Example 2 of the present invention, the relationship between the pH value of the dissolving agent and the peel strength was tested.

[FIG. 5] In Example 2 of the present invention, the thickness and composition of the layer containing copper oxide in the copper foil after the roughening treatment were measured.

[FIG. 6] In Example 3 of the present invention, with respect to the copper foil subjected to the oxidation treatment, the influence of the time of the dissolution treatment was tested.

[FIG. 7] In Example 4 of the present invention, the influence of the time of oxidizing treatment was tested for copper foil.

Hereinafter, embodiments of the present invention will be described in detail while giving examples. In addition, from the description of this specification, those with ordinary knowledge in the technical field to which the invention pertains will understand the object of the present invention. The present invention can be easily reproduced by those with ordinary knowledge in the technical field to which the invention belongs, based on the description of the present specification. The embodiments and specific examples of the invention described below represent preferred embodiments of the present invention, are used for illustration and description, and are not intended to limit the present invention. It will be apparent to those skilled in the art to which the present invention pertains that various modifications can be made based on the description of the present specification within the intent and scope of the present invention disclosed in the present specification.

Object with a roughened copper surface: An object with a roughened copper surface according to an embodiment of the present invention is an object with a surface covered with copper, and has protrusions on at least a part of the copper surface, The surface of the convex portion contains copper oxide (Cu ₂ O+CuO), and the inside of the convex portion contains copper.

An object with a copper surface may also be an object formed of copper, or a surface of an object formed of something other than copper is provided with a copper layer, or coated with copper, the copper covering the surface and the copper oxide-containing object. The thinnest part of the layer is preferably 6 nm or more, more preferably 10 nm or more, and still more preferably 100 nm or more. The copper thickness can be determined by combining Ar ion sputtering etching of the sample surface with elemental analysis of the surface by X-ray photoelectron spectroscopy (XPS).

The shape of this object is not particularly limited, and may be, for example, foil, particle, or powder, or may be copper foil, copper particles, or copper particles containing copper as its main component.

On the surface of the object, the number of protrusions having a height of 50 nm or more per 3.8 μm is preferably 5 or more on average, more preferably 10 or more, and still more preferably 20 or more. This number is, for example, in the SEM image of the cross-section, for the line connecting the minimum points of the adjacent concave parts, the distance between the midpoint of the line and the maximum point of the convex part existing between the adjacent concave parts is used as the height of the protrusions. The number can be counted by calculating the number of protrusions with a height of 50 nm or more. Furthermore, the average of the heights of the convex portions is preferably 500 nm or less, and more preferably 350 nm or less. In addition, the average of the heights of the convex portions is preferably 20 nm or more, and more preferably 50 nm or more.

The content ratio of Cu/O at a depth of 6 nm (in terms of SiO ₂ ) is not particularly limited, but is preferably 5 or less, more preferably 4 or less, and still more preferably 3 or less. The content ratio of Cu/O at a depth of 12 nm (in terms of SiO ₂ ) is not particularly limited, but is preferably 8 or less, more preferably 6 or less, and still more preferably 4 or less. The content ratio of Cu/O at a depth of 18 nm (in terms of SiO ₂ ) is not particularly limited, but is preferably 5 or less, more preferably 4 or less, and still more preferably 3 or less. The content ratio of Cu/O at a depth of 40 nm (in terms of SiO ₂ ) is not particularly limited, but is preferably 20 or less, more preferably 16 or less, more preferably 12 or less, and preferably 2.0 or more, more preferably 2.5 or more, It is also preferable that it is 3.0 or more. This content ratio can be calculated by combining the etching of the sample surface by Ar ion sputtering and the measurement of the content of each substance on the sample surface by X-ray photoelectron spectroscopy (XPS). In addition, when Ar ion sputtering is performed, the plane position preliminarily assumed on the sample surface is used as the starting point of the depth.

The thickness of the layer containing copper oxide on the surface of the convex portion is not particularly limited. When measured by SERA and converted to a uniform thickness, the thickness of the layer containing copper oxide is preferably 1 nm or more from the convex portion surface, more preferably 4 nm or more. , and preferably 8 nm or more. Moreover, 150 nm or less is preferable, and 50 nm or less is more preferable. Thereby, the copper surface with high peeling strength with a prepreg can be formed.

Method for roughening copper surface: The method for roughening copper surface according to an embodiment of the present invention includes a first step and a second step. The first step oxidizes the copper surface, and the second step dissolves the oxidized copper surface.

First, in the first step, the surface of copper is oxidized with an oxidizing agent to form a layer containing copper oxide, and at the same time, protrusions are formed on the surface.

Prior to this oxidation step, degreasing can be carried out by alkaline treatment. The method of this alkali treatment is not particularly limited, preferably an alkaline aqueous solution of 30~50g/L, more preferably an alkaline aqueous solution of 40g/L, an alkaline aqueous solution such as an aqueous sodium hydroxide solution, treated at 30~50°C for 0.5~ After about 2 minutes, wash with water. After that, in order to remove the natural oxide film and reduce the unevenness of the treatment, it can be washed with an acid. This cleaning treatment can be performed, for example, by immersing the copper surface in a liquid temperature of 20 to 50° C. and 5 to 20% by weight of sulfuric acid for 1 to 5 minutes, followed by water washing. To reduce uneven treatment and prevent cleaning treatment The oxidizing agent of the acid to be used can be mixed in, and further weak base treatment can be performed. The alkali treatment method is not particularly limited, preferably 0.1~10g/L alkaline aqueous solution, more preferably 1~2g/L alkaline aqueous solution, alkaline aqueous solution such as sodium hydroxide aqueous solution, at 30~50 ℃ treatment After about 0.5 to 2 minutes, wash with water. Moreover, as a pre-processing, the process of physically roughening a copper surface, such as etching, may be performed. Furthermore, these steps are not essential components of the present invention.

An oxidizing agent can be used in the oxidation step. The oxidizing agent is not particularly limited, and for example, an aqueous solution of sodium chlorite, sodium hypochlorite, potassium chlorate, potassium perchlorate, or the like can be used. Various additives (such as phosphates such as trisodium phosphate dodecahydrate) or interfacial active molecules can be added to the oxidizing agent. The interface-active molecules include, for example, porphyrin, porphyrin macrocycle, expanded porphyrin, condensed porphyrin, porphyrin linear polymer, porphyrin sandwich coordination complex, porphyrin array, silane, tetraorgano-silane , aminoethyl-aminopropyl-trimethoxysilane, (3-aminopropyl)trimethoxysilane, (1-[3-(trimethoxysilyl)propyl]urea), (3 -Aminopropyl)triethoxysilane, (3-glycidoxypropyl)trimethoxysilane, (3-chloropropyl)trimethoxysilane, (3-glycidoxypropyl) ) trimethoxysilane, dimethyldichlorosilane, 3-(trimethoxysilyl)propyl methacrylate, ethyltriacetoxysilane, triethoxy(isobutyl)silane, trimethoxysilane Ethoxy(octyl)silane, gins(2-methoxyethoxy)(vinyl)silane, chlorotrimethylsilane, methyltrichlorosilane, silicon tetrachloride, tetraethoxysilane, benzene trimethoxysilane, chlorotriethoxysilane, vinyl-trimethoxysilane, amine, sugar, etc. In addition, the oxidizing agent may be used in combination with solvents such as alcohols, ketones, and carboxylic acids.

The oxidation reaction conditions are not particularly limited, and the liquid temperature of the oxidizing agent is preferably 40 to 95°C, more preferably 40 to 90°C. The reaction time is preferably 0.5 to 30 minutes, more preferably 1 to 10 minutes.

Next, the oxidized copper surface is dissolved with a dissolving agent, and the convex part of the oxidized copper surface is adjusted. The dissolving agent used in this step is not particularly limited, for example, a chelating agent, a biodegradable chelating agent, etc., for example, EDTA (ethylenediaminetetraacetic acid), DHEG (dihydroxyethylglycine), GLDA (tetrasodium L-glutamic acid diacetate), EDDS (ethylenediamine-N,N'-disuccinic acid), HIDS (sodium 3-hydroxy-2,2'-iminodisuccinic acid), MGDA (Trisodium Methylglycine Diacetate), ASDA (tetrasodium aspartate diacetate), HIDA (disodium N-2-hydroxyethyliminodiacetate), sodium gluconate, hydroxyethylidene diphosphonic acid, etc.

The dissolving agent used in this step can be used in combination with solvents such as alcohols, ketones, and carboxylic acids. The pH of the dissolving agent is not particularly limited, but since the amount of dissolving in the acid is large, the treatment control is difficult, the treatment unevenness is likely to occur, and the convex portion formed by the optimal Cu/O ratio will not be formed, so it is preferably an alkali. It is more preferably pH9.0~14.0, more preferably pH9.0~10.5, still more preferably pH9.8~10.2.

In this step, the dissolution rate of the treated copper surface to copper oxide is 35-99%, preferably 77-99%, and the thickness of CuO is 4-150 nm, preferably 8-50 nm. Under this condition, the peeling strength with the prepreg becomes high, so it is preferable to perform a pre-test in advance, and set conditions such as temperature and time to obtain such a copper oxide layer.

After the above steps, a coupling treatment using a silane coupling agent or the like or a rust preventive treatment using a benzotriazole or the like can be performed.

Method for producing an object with a roughened copper surface: A method for producing an object with a roughened copper surface according to an embodiment of the present invention, comprising using the above-mentioned method for roughening the copper surface, the object Has the copper surface oxidation steps. By using this manufacturing method, the object which has the copper surface after roughening process mentioned above can be manufactured.

Utilization method of objects with roughened copper surface: The above roughening method can be used for the roughening of copper foils used for printed wiring boards, copper wires wired to substrates, and copper foils for LIB negative electrode collectors. processing.

For example, it can be used to roughen the surface of the copper foil used for the printed wiring board, and to adhere to the resin in a layered form, thereby producing a laminate to manufacture a printed wiring board. In this case, the kind of resin is not particularly limited, and polyphenylene ether, epoxy resin, PPO, PBO, PTFE, LCP or TPPI is preferably used.

Example 1: [Surface Roughening Treatment of Copper Foil] Using DR-WS (Furukawa Electric Co., Ltd. Co., Ltd., thickness 18 μm) as the copper foil of the implementation sample and the comparative sample, the glossy surface (flat surface when compared with the opposite surface) was roughened.

(1) Pretreatment: First, all copper foils were subjected to alkaline degreasing treatment at 50° C. for 1 minute with a 40 g/L sodium hydroxide aqueous solution. After that, acid cleaning was performed by immersing in 10% by weight of sulfuric acid at room temperature for several minutes and then washing with water.

(2) Soft etching treatment: The copper foil of Comparative Sample 1 was subjected to a soft etching treatment at 35° C. for 2 minutes with a 100 g/L sodium persulfate aqueous solution. Soft etching is not performed on other copper foils.

(3) Alkali treatment: Next, in order to prevent the incorporation of acid used for acid cleaning, preconditioning was performed with a 1.2 g/L sodium hydroxide aqueous solution at 40° C. for 1 minute. Moreover, the comparative sample 1 was alkali-treated with the sodium hydroxide aqueous solution of 40 g/L at 50 degreeC for 1 minute.

(4) Oxidation treatment: For samples other than Comparative Sample 1, the copper foil subjected to alkali treatment was subjected to oxidation treatment with an aqueous solution for oxidation treatment (NaClO ₂ 63 g-NaOH 10.5 g/L) at 70° C. for 2 minutes. Moreover, with respect to the comparative sample 1, oxidation treatment was performed at 75 degreeC for ₃ minutes with the different aqueous solution (NaClO2 120g-NaOH 40g/L) for oxidation treatment. After the above treatment, the copper foil is washed with water.

(5) Dissolution treatment: The copper foil after the oxidation treatment was dissolved in the following 0.1 M aqueous solution at 55°C for the following time.

Implementation sample 1: trisodium methylglycine diacetate, 3 minutes

Implementation Sample 2: HIDS, 5 minutes

Implementation Sample 3: GLDA, 5 minutes

Implementation Sample 4: EDTA, 3 minutes

Comparative Sample 1: EDTA, 3 minutes

In addition, the comparative sample 2 was not melt|dissolved, and the comparative sample 3 was reduced with the aqueous solution for reduction (5 g of dimethylamine borane-5 g/L of sodium hydroxide) at 23 degreeC for 1 minute. After the above treatment, the copper foil is washed with water.

(6) Post-treatment: Only Comparative Sample 1 was subjected to post-treatment at 70° C. for 1 minute with a 3 g/L aqueous solution of benzotriazole. This is for rust prevention. This treatment is not carried out for other copper foils.

(7) Measurement of peel strength: The untreated copper foil without any of the above treatments was taken as the comparative sample 4, and the peel strength (Initials) after lamination was tested for each copper foil of the samples 1 to 4 and the comparative samples 1 to 4. and peel strength (Acid) after acid treatment. First, each copper foil laminate prepreg (R5670KJ manufactured by Panasonic Co., Ltd.) was held in a vacuum at 210° C. for 30 minutes using a vacuum high pressure press to obtain a measurement sample (Initial). In order to test the resistance to acid, the laminated copper foil was immersed in a HCl aqueous solution (4N) at 60° C. for 90 minutes to obtain a measurement sample (Acid). The peeling strength (kgf/cm) was calculated|required about the said measurement sample by the 90 degree peeling test (Japanese Industrial Standard (JIS) C5016). The larger the peel strength, the higher the adhesion between the prepreg and the copper foil. The results are shown in Table 1.

(8) Analysis by X-ray Photoelectron Spectroscopy (XPS): For each of the copper foils of the implementation samples 1 to 4 and the comparative samples 1 to 4, the ratio of Cu to O was determined according to the depth by XPS. Using Quantera SXM (manufactured by ULVAC-PHI) as the measuring device, and using monochromatic AlKα (1486.6 eV) as the excitation X-ray, Narrow Spectrum was obtained for the 4 elements (C1s, N1s, O1s, Cu2p3) detected by the Survey Spectrum . Ar sputtering was performed 12 times at intervals of 2.5 minutes in the depth direction, and the measurement and sputtering were repeated to obtain data. The results are shown in Fig. 1 (Comparative Examples 1, 2, and Examples 3 and 4 are shown as representative) and the first table. In addition, each measurement was performed under the following conditions.

<Survey spectrum>

X-ray beam diameter: 100μm (25w15kV)

Pass energy: 280eV, 1eV step

Line analysis: φ100μm*1200um

Accumulated times 6 times

<Narrow spectrum>

X-ray beam diameter: 100μm (25w15kV)

Pass energy: 112eV, 0.1eV step

Line analysis: φ100μm*1200um

<Ar sputtering conditions>

Accelerating voltage 1kV

Irradiation area 2x2mm

Sputtering speed 2.29nm/min (SiO ₂ conversion)

(9) Analysis of surface protrusions by scanning electron microscope: For each copper foil of Samples 1 to 4 and Comparative Samples 1 to 4, take pictures with a Scanning Electron Microscope (SEM) (as shown in Figure 2), and calculate the cross section of each copper foil. The length and number of protrusions. Specifically, the length of the protrusions was obtained by taking SEM images of 5 positions (50,000 times of FIB-SEM) (as shown in Figures 2A and C), and 10 protrusions were randomly selected in each image. A line connecting the minimum points of the concave portion, the distance between the midpoint of the line and the maximum point of the convex portion of the protrusion is calculated as the height of the protrusion (Fig. 3A), and the overall average value is calculated. In addition, the number of protrusions is obtained from SEM images (30,000 times of FIB-SEM) at 5 positions (such as Figures 2B and D), and the line connecting the minimum points for the adjacent concave parts, the midpoint of this line and the The distance between the maximum points of the convex portions existing between adjacent concave portions was used as the height of the protrusions. At this time, the number of convex portions having a height of 50 nm or more was calculated (Fig. 3B), and the overall average value was calculated. The results are shown in Table 1.

(10) Results:

In Comparative Sample 1 and Comparative Sample 3, the ratio of Cu/O was high. This shows that the adhesion is low even if the surface roughness is large because the copper component is easily diffused in the base material after lamination. In addition, the comparative sample 2 showed that the peeling strength after the acid treatment was low, and the acid resistance was low, but this is presumably because the amount of copper oxide was large because there was only an oxidation step. None of the copper foils of the implementation samples had such a disadvantage.

Example 2: In this example, the effect of pH value during dissolution treatment on copper foil subjected to peroxide treatment was tested.

First, a dissolving treatment liquid was prepared, which was obtained by adding 4N H ₂ SO ₄ to a 0.1M EDTA·4Na·4H ₂ O solution and adjusting to several pH values between pH 3.5 and 11. The copper foil subjected to the oxidation treatment in the same manner as in Example 1 was dissolved in the above-mentioned dissolution treatment solution at 55° C. for 3 minutes, using EM355B(D) (manufactured by Taiguang Electronics Co., Ltd.) or R5670KJ as a prepreg, and the same Example 1 The peel strength was measured in the same manner.

As a result, as shown in Fig. 4, regardless of which prepreg was used, the peel strength reached a maximum in the vicinity of the pH value of 10.0, and the adhesion decreased when it was more acidic or alkaline. Thus, from the viewpoint of peeling strength, pH 9.0 to 10.5 is preferable for the dissolution treatment, and pH 9.8 to 10.2 is more preferable.

Next, the oxide film thickness of each copper foil obtained by dissolving was measured by SERA (Surface-Scan QC-100, ECI Technology Co., Ltd.). The aqueous solution of boric acid (6.18g/L boric acid, 9.55g/L sodium tetraborate) is used as the electrolyte to contact the metal surface, and is determined by -0.3V~-0.55V, -0.55V~-0.85V, -0.85V~-1.0V The reduction time is required, and the thicknesses of Cu ₂ O, CuO, and Cu ₂ S are calculated using the following formulas, respectively. (Also, current density=90 μA/cm ² )

Cu ₂ O(nm)=0.0124*current density(μA/cm ² )*reduction time(sec)*0.1

CuO(nm)=0.00639*current density(μA/cm ² )*reduction time(sec)*0.1

Cu ₂ S(nm)=0.0147*current density(μA/cm ² )*reduction time(sec)*0.1

As a result, as shown in Fig. 5, the thickness of the oxide film reaches the maximum at pH 10.41, and becomes thinner in acidity and alkalinity. The type of copper oxide constituting the oxide film is mainly CuO regardless of pH value. In this way, the dissolution treatment is preferably pH 9.0 to 10.5, more preferably pH 9.15 to 10.41, in terms of the state of formation of copper oxide.

Example 3: In this example, various changes were made to the treatment time of the oxidation treatment and the dissolution treatment, and their effects were tested.

First, oxidation treatment and dissolution treatment were performed in the same procedure as in Example 1, except that the treatment time was changed. In addition, the times of the oxidation treatment and the dissolution treatment were set to 1 minute, 2 minutes, 3 minutes, 5 minutes, 7 minutes, and 10 minutes, respectively. In each time, the amount of copper oxide dissolved by the dissolution treatment relative to the amount of copper oxide produced by the oxidation treatment was calculated as the dissolution rate (%), and the thickness of the layer containing copper oxide was measured by SERA in the same manner as in Example 2. The copper foil after the roughening treatment in which the combination of these factors is an influencing factor was used as a sample, and the peel strength was measured in the same manner as in Example 1. The results are shown in Figure 6.

When forming a copper foil with a peel strength of 0.15 or more, the copper surface is treated so that the dissolution rate of copper oxide is 35 to 99% and the thickness of CuO is 4 to 150 nm. In most cases, the dissolution rate of copper oxide is is 77~99% and the thickness of CuO is in the range of 8~50nm. The dissolution treatment is performed to reach this range, whereby the peel strength between the copper surface and the prepreg is high and treatment unevenness is reduced.

Example 4: In this example, the effect of the time of oxidizing copper foil was tested.

After the oxidation treatment of copper foil was carried out in the same manner as in Example 3, except that the oxidation time was set to 1 minute, 2 minutes, and 4 minutes, a dissolution treatment was performed, and EM355B(D) or R5670KJ was used as a prepreg, and the same as in Example 3 1 The peel strength was measured in the same manner. The sample which was subjected to reduction treatment after dissolution treatment was used as a comparative example, and its peel strength was measured.

As shown in Fig. 7, the peeling strength of almost all the samples was 0.15 or more regardless of the oxidation treatment time, and good adhesion to the prepreg could be obtained, but in the case of the reduction treatment, there were The sample could not obtain good adhesion to the prepreg.

In this way, according to the method of the present invention, good adhesion to the prepreg can be obtained regardless of the oxidation treatment time.

Industrial Applicability: According to the present invention, an object having a roughened copper surface can be provided.

Claims (15)

An object having a roughened copper surface, having a surface covered with copper with a thickness of 6 nm or more, wherein at least a part of the copper surface has a convex portion, the surface of the convex portion contains copper oxide, and the interior of the convex portion contains Copper has an average of 5 or more protrusions with a height of 50 nm or more per 3.8 μm in cross-section, and the average length of the protrusions is 500 nm or less, and the depth of 6 nm (in terms of SiO ₂ ) The content ratio of Cu/O is 5 or less, for the line connecting the minimum points of the concave portions on both sides of the convex portion in the cross-sectional image captured by the scanning electron microscope, the distance between the midpoint of the line and the maximum point of the convex portion is measured as the height of the convex portion . The object of claim 1, wherein the object is copper foil, copper particles, copper powder or copper-plated objects. The object of claim 1 or 2, wherein the layer containing the copper oxide has a thickness of 8 to 50 nm. 2. The object of claim 1 or 2, wherein the thickness of the layer comprising the copper oxide is measured by a continuous electrochemical reduction method (SERA). The object of claim 1 or 2, wherein the depth is determined by X-ray photoelectron spectroscopy. A method for roughening a copper surface, comprising: a first step of oxidizing the copper surface; and a second step of dissolving the oxidized copper surface. The method of claim 6, wherein the alkaline treatment is performed using an alkaline aqueous solution before the first step. The method of claim 6 or 7, wherein in the first step the copper surface is oxidized agent oxidation. The method of claim 6 or 7, wherein the oxidized copper surface is dissolved by a dissolving agent in the second step. The method of claim 9, wherein the pH of the dissolving agent is pH 9.0 to 14.0. The method of claim 6 or 7, wherein the oxidized copper surface is dissolved so that the dissolution rate of the copper oxide produced by the oxidation of the copper surface is 35-99%, and the thickness of the oxide film measured by SERA is 4-99% 150nm. A method for manufacturing an object, which is to manufacture the object according to any one of claims 1 to 5, comprising: the step of treating copper on the surface of the object with the method according to any one of claims 6 to 10. A method for manufacturing a laminate, which is a method for manufacturing a laminate of copper foil and resin, the copper foil being an object as claimed in any one of claims 1 to 5, the manufacturing method comprising adhering the object and the resin into a layered shape steps. The method for producing a laminate according to claim 13, wherein the resin is polyphenylene ether. A method for manufacturing a printed wiring board, comprising a laminate manufacturing step of the method for manufacturing a laminate according to any one of claims 12 to 14.

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