KR102490491B1 - Roughened copper foil, copper-clad laminate, and printed wiring board - Google Patents

Abstract

Although it is a low-intensity fine irregularity suitable for fine pitch circuit formation and high-frequency applications, it is excellent not only in adhesion to resin but also in friction resistance, so even after being rubbed against an object in the processing of a copper-clad laminate or the production of a printed wiring board, resin A roughened copper foil capable of stably exhibiting excellent adhesion to is provided. The roughened copper foil of the present invention has, on at least one side, a roughened surface provided with fine concavities and convexities composed of acicular crystals and/or plate-like crystals. As for the roughening process surface, maximum height Sz measured based on ISO25178 is 1.5 micrometers or less, and arithmetic mean curve Spc of the peak measured based on ISO25178 is 1300 mm< ^-1 > or less.

Description

Roughened copper foil, copper-clad laminate, and printed wiring board

This invention relates to a roughening process copper foil, a copper clad laminated board, and a printed wiring board.

As a printed wiring board copper foil suitable for formation of a fine pitch circuit, a roughened copper foil provided with fine irregularities formed through oxidation treatment and reduction treatment (hereinafter sometimes referred to collectively as oxidation reduction treatment) as a roughening treatment surface is proposed. has been

For example, in Patent Document 1 (International Publication No. 2014/126193), surface-treated copper provided with a surface-treated layer formed of needle-like or plate-like fine irregularities made of a copper complex compound having a maximum length of 500 nm or less on the surface. Park is initiated. Further, in Patent Document 2 (International Publication No. 2015/040998), a roughening treatment layer having fine concavities and convexities formed of acicular or plate-shaped convex-shaped portions having a size of 500 nm or less in maximum length made of a copper composite compound, and the roughening Disclosed is a copper foil provided with a silane coupling agent treated layer on at least one surface of the treated layer. According to the roughened copper foil of these literatures, while being able to obtain good adhesion to the insulating resin substrate by the anchor effect due to the fine irregularities of the roughened layer, a fine pitch circuit provided with a good etching factor. It is said that formation is possible. All of the roughening treatment layers having fine concavities and convexities disclosed in Patent Literatures 1 and 2 are formed through oxidation-reduction treatment after performing preliminary treatment such as alkali degreasing. The fine concavities and convexities formed in this way have a unique shape composed of acicular crystals and/or plate-like crystals of the copper composite compound, and the roughened surface provided with these fine concavities and convexities is a roughening surface formed by adhesion of fine copper particles. It is generally finer than a cotton-processed surface or a roughened-processed surface to which irregularities are provided by etching.

On the other hand, with the recent high performance of portable electronic devices and the like, high-frequency signals are progressing in order to process a large amount of information at high speed, and printed wiring boards suitable for high-frequency applications are required. In such a printed wiring board for high frequencies, reduction in transmission loss is desired in order to enable transmission of high frequency signals without deterioration in quality. A printed wiring board includes a copper foil processed into a wiring pattern and an insulating resin substrate, but transmission loss mainly consists of conductor loss due to the copper foil and dielectric loss caused by the insulating resin substrate. In addition, the conductor loss can be further increased due to the skin effect of the copper foil, which appears remarkably as the frequency increases. For this reason, in order to aim at the reduction of the transmission loss in a high frequency use, a copper foil of low illumination is calculated|required as a copper foil which can reduce conductor loss. From this point, it is said that the copper foil provided with the roughening process layer mentioned above by patent document 2 is suitable as a high frequency circuit formation material.

International Publication No. 2014/126193 International Publication No. 2015/040998

However, the fine irregularities formed through the redox treatment are friction between copper foils (eg, which may occur when copper foil is pulled out from a roll state) or friction with other members (eg, conveying rollers). are prone to shape deterioration. This is because the above microreliefs are composed of needle-like crystals and/or plate-like crystals of the copper composite compound, so that the needle-like crystals and/or plate-like crystals may break or, in some cases, fall over. In this way, the shape-degraded fine irregularities not only impair the appearance of the roughened copper foil, but also reduce the anchor effect to the insulating resin substrate due to the fine irregularities. For this reason, there is a concern of causing a decrease in yield due to poor appearance or deterioration of performance (in particular, decrease in adhesion to resin).

The inventors of the present invention control the shape of fine irregularities formed through the oxidation-reduction treatment this time so that the maximum height Sz measured in accordance with ISO25178 is 1.5 μm or less, and the arithmetic mean curve Spc of the peaks measured in accordance with ISO25178 is obtained. By setting it to 1300 mm ^-1 or less, it is excellent in not only adhesion to resin but also friction resistance, even though it is a low-intensity fine irregularity suitable for fine pitch circuit formation and high-frequency applications, and therefore, something in the processing of copper-clad laminates and the production of printed wiring boards. It was found that excellent adhesion to resin can be stably exhibited even after being rubbed against an object.

Accordingly, an object of the present invention is to provide low-intensity fine concavities and convexities suitable for fine pitch circuit formation and high-frequency applications, but also have excellent adhesion to resin as well as friction resistance. It is to provide the roughening process copper foil which can exhibit excellent adhesiveness with resin stably even after rubbing against an object.

According to one aspect of the present invention, it is a roughened copper foil having at least one side a roughened treated surface with fine irregularities composed of acicular crystals and/or plate-like crystals, wherein the roughened treated surface complies with ISO25178 The maximum height Sz measured by doing is 1.5 micrometers or less, and the arithmetic mean curve Spc of the peak measured based on ISO25178 is 1300 mm ^-1 or less, and the roughening process copper foil is provided.

According to another aspect of this invention, the copper clad laminated board provided with the roughening process copper foil of the said aspect is provided.

According to another aspect of this invention, the printed wiring board provided with the roughening process copper foil of the said aspect is provided.

Justice

Definitions of terms and parameters used to specify the present invention are given below.

In this specification, "maximum height Sz" is a parameter that indicates the distance from the highest point to the lowest point on the surface measured based on ISO25178. Maximum height Sz is computable by measuring the surface profile of the predetermined|prescribed measurement area (for example, 22500 micrometer< ² > two-dimensional area|region) in a roughening process surface with a commercially available laser microscope.

In this specification, "arithmetic average curve Spc of mountain peaks" is a parameter representing the arithmetic average of the principal curvatures of mountain peaks in the positive region, measured in accordance with ISO25178. A small value indicates that the contact point with another object is round. On the other hand, when this value is large, it indicates that the contact point with another object is sharp. Simply put, it can be said that the arithmetic mean curve Spc of the mountain peak is a parameter indicating the degree of roundness of the lump that can be measured with a laser microscope. The arithmetic mean curve Spc of the peaks can be calculated by measuring the surface profile of a predetermined measurement area (for example, a two-dimensional area of 100 μm ² ) on the roughened surface with a commercially available laser microscope.

In this specification, the "electrode surface" of an electrolytic copper foil refers to the side surface which was in contact with the cathode at the time of electrolytic copper foil production.

In this specification, the "precipitation surface" of an electrolytic copper foil refers to the side surface on which electrolytic copper precipitates at the time of electrolytic copper foil production, ie, the side surface which is not in contact with the cathode.

Roughened Copper Foil

The copper foil of this invention is a roughening process copper foil. This roughening process copper foil has a roughening process surface on at least one side. The roughened surface has fine concavities and convexities composed of acicular crystals and/or plate-like crystals, and these fine concavities and convexities can be formed through oxidation-reduction treatment. Typically, the acicular crystals and/or plate-like crystals are It is observed in a lush shape (for example, a lawn shape) in a substantially perpendicular and/or inclined direction with respect to the copper foil surface. And the largest height Sz of this roughening process surface measured based on ISO25178 is 1.5 micrometers or less, and the arithmetic mean curve Spc of the peak measured based on ISO25178 is 1300 mm< ^-1 > or less. In this way, by controlling the shape of fine concavities and convexities formed through oxidation-reduction processing so that the maximum height Sz is 1.5 μm or less and the peak arithmetic mean curve Spc is 1300 mm ^-1 or less, fine pitch circuit formation and high frequency applications It has excellent adhesion to resin as well as friction resistance, and therefore, even after rubbing against an object in the processing of copper-clad laminates or the production of printed wiring boards, excellent adhesion to resin is stable. It becomes possible to exert In particular, as defined above, the arithmetic average curve Spc of the peak is a parameter representing the degree of roundness of the bump, and the smaller the value, the rounder the point in contact with another object. Therefore, it is considered that the above excellent friction resistance is because the needle-like crystals and/or the plate-like crystals are less likely to break or collapse by reducing this Spc to 1300 mm ^-1 or less. That is, as described above, the fine irregularities formed through the conventional redox treatment are easily degraded in shape due to friction between copper foils or friction with other members, resulting in poor appearance or deterioration of performance (in particular, adhesion to resin). Although there was a concern of causing a decrease in yield due to a decrease in ), according to the roughened copper foil of the present invention, such a technical subject can be solved.

The maximum height Sz on the roughened surface is 1.5 µm or less, preferably 1.2 µm or less, and more preferably 1.0 µm or less. If Sz is within this range, it becomes more suitable for fine pitch circuit formation and high frequency applications. In particular, such a low illumination reduces the skin effect of the copper foil, which is a problem in high-frequency signal transmission, reduces the conductor loss caused by the copper foil, and thereby significantly reduces the transmission loss of the high-frequency signal. The lower limit of Sz is not particularly limited, but from the viewpoint of improving adhesion with the resin, Sz is preferably 0.1 μm or more, more preferably 0.2 μm or more, and still more preferably 0.3 μm or more.

The arithmetic mean curve Spc of the peak peaks in the roughened surface is 1300 mm ^-1 or less, preferably 1200 mm ^-1 or less, more preferably 1000 mm ^-1 or less. If it is Spc within these ranges, since it can be set as a rounded hump shape which is less likely to rub, friction resistance can be improved. The lower limit of Spc is not particularly limited, but is preferably 100 mm ^-1 or more, more preferably 200 mm ^-1 or more, and still more preferably 300 mm ^-1 or more.

As described above, the fine irregularities on the roughened surface are composed of acicular crystals and/or plate-like crystals. The height of the needle-like crystals and/or plate-like crystals (that is, the height measured in the vertical direction from the base of the needle-like crystals and/or plate-like crystals) is preferably 50 to 400 nm, more preferably 100 to 400 nm, still more Preferably it is 150-350 nm.

The thickness of the roughened copper foil of the present invention is not particularly limited, but is preferably 0.1 to 35 μm, more preferably 0.5 to 18 μm. Moreover, the roughening process copper foil of this invention is not limited to what performed the roughening process on the normal copper foil surface, What performed the roughening process on the copper foil surface of copper foil with a carrier may be sufficient.

manufacturing method

The roughening-treated copper foil according to the present invention may be manufactured by any method, but is preferably manufactured through oxidation-reduction treatment. Hereinafter, an example of the preferable manufacturing method of the roughening process copper foil by this invention is demonstrated. This preferred manufacturing method includes a step of preparing a copper foil having a surface with a maximum height Sz of 1.5 µm or less, and a roughening step (oxidation-reduction treatment) of sequentially performing a preliminary treatment, an oxidation treatment, and a reduction treatment on the surface, It is done.

(1) Preparation of copper foil

As copper foil used for manufacture of a roughening process copper foil, use of both an electrolytic copper foil and a rolled copper foil is possible, More preferably, it is an electrolytic copper foil. In addition, the copper foil may be non-roughened copper foil, or may have been subjected to preliminary roughening. The thickness of the copper foil is not particularly limited, but is preferably 0.1 to 35 μm, more preferably 0.5 to 18 μm. When the copper foil is prepared in the form of a copper foil with a carrier, the copper foil is formed by a wet film formation method such as an electroless copper plating method and an electrolytic copper plating method, a dry film formation method such as sputtering and chemical vapor deposition, or a combination thereof. It can be done.

It is preferable that the maximum height Sz of the surface of the copper foil to which a roughening process is performed is measured based on ISO25178 is 1.5 micrometer or less, More preferably, it is 1.2 micrometer or less, More preferably, it is 1.0 micrometer or less. If it is in the said range, it becomes easy to realize the surface profile requested|required of the roughening process copper foil of this invention, especially the maximum height Sz of 1.5 micrometers or less in a roughening process surface. The lower limit of Sz is not particularly limited, but Sz is preferably 0.1 μm or more, more preferably 0.2 μm or more, and still more preferably 0.3 μm or more.

(2) Roughening treatment (oxidation-reduction treatment)

In this way, it is preferable to perform a wet roughening step of sequentially performing a preliminary treatment, an oxidation treatment, and a reduction treatment with respect to the surface of the copper foil to which the above-mentioned low Sz is provided. In particular, a copper compound containing copper oxide (cupric oxide) is formed on the surface of the copper foil by subjecting the surface of the copper foil to oxidation treatment by a wet method using a solution. Thereafter, the copper compound is subjected to a reduction treatment to convert a part of the copper oxide to cuprous oxide (cuprous oxide), thereby forming a microstructure composed of needle-like crystals and/or plate-like crystals composed of copper oxide and a copper complex compound containing cuprous oxide. Concavo-convex can be formed on the surface of the copper foil. Here, the fine irregularities are formed by a copper compound containing copper oxide as a main component in the step of oxidizing the surface of the copper foil by a wet method. Then, when the copper compound is subjected to a reduction treatment, a part of the copper oxide is converted to cuprous oxide while maintaining the shape of the fine concavo-convex formed by the copper compound to form a copper complex compound containing copper oxide and cuprous oxide. It becomes a fine irregularity formed. In this way, formation of fine concavities and convexities on the order of nm becomes possible by performing a reduction treatment after performing an appropriate oxidation treatment on the surface of the copper foil by a wet method.

(2a) Preliminary treatment

Prior to the oxidation treatment, it is preferable to perform a preliminary treatment such as degreasing on the copper foil. In this preliminary treatment, it is preferable to wash with water after immersing the copper foil in an aqueous sodium hydroxide solution and performing an alkali degreasing treatment. Preferable sodium hydroxide aqueous solution has a NaOH concentration of 20 to 60 g/L, a solution temperature of 30 to 60°C, and a preferred immersion time is 2 seconds to 5 minutes. Further, it is preferable to wash with water after immersing the copper foil subjected to the alkali degreasing treatment in a sulfuric acid-based aqueous solution. A preferable sulfuric acid-based aqueous solution has a sulfuric acid concentration of 1 to 20% by mass, a liquid temperature of 20 to 50°C, and a preferable immersion time is 2 seconds to 5 minutes.

(2b) oxidation treatment

An oxidation treatment is performed using an alkali solution such as a sodium hydroxide solution with respect to the copper foil subjected to the above-described preliminary treatment. By oxidizing the surface of the copper foil with an alkaline solution, fine concavities and convexities composed of needle-like crystals and/or plate-like crystals made of a copper complex compound containing copper oxide as a main component can be formed on the surface of the copper foil. At this time, the temperature of the alkaline solution is preferably 60 to 85 ° C, and the pH of the alkaline solution is preferably 10 to 14. In view of oxidation, the alkali solution preferably contains chlorates, chlorites, hypochlorites, and perchlorates, and the concentration thereof is preferably 100 to 500 g/L. The oxidation treatment is preferably performed by immersing the electrolytic copper foil in an alkaline solution, and the immersion time (ie, oxidation time) is preferably 10 seconds to 20 minutes, more preferably 30 seconds to 10 minutes.

It is preferable that the alkaline solution used for oxidation treatment further contains an oxidation inhibitor. That is, when oxidation treatment is performed on the surface of the copper foil with an alkali solution, the convex portion may grow excessively and exceed a desired length, making it difficult to form desired fine irregularities. Then, in order to form the said microrelief, it is preferable to use the alkaline solution containing the oxidation inhibitor which can suppress oxidation in the copper foil surface. An amino-type silane coupling agent is mentioned as an example of a preferable oxidation inhibitor. By subjecting the copper foil surface to oxidation treatment using an alkaline solution containing an amino-based silane coupling agent, the amino-based silane coupling agent in the alkaline solution is adsorbed on the surface of the copper foil, and oxidation of the copper foil surface by the alkaline solution can suppress As a result, the growth of acicular crystals and/or plate-like crystals of copper oxide can be suppressed, and a preferable roughened surface with extremely fine irregularities can be formed. Specific examples of the amino silane coupling agent include N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, and 3-aminopropyltri. Methoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, etc. and N-2-(aminoethyl)-3-aminopropyltrimethoxysilane is particularly preferred. All of these are dissolved in the alkaline solution, and while being stably maintained in the alkaline solution, they exert the effect of suppressing the above-mentioned oxidation of the copper foil surface. The preferred concentration of the amino-based silane coupling agent (for example, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane) in the alkaline solution is 0.01 to 20 g/L, more preferably 0.02 to 20 g/L. 20 g/L.

(2c) reduction treatment

The copper foil subjected to the oxidation treatment (hereinafter referred to as oxidation-treated copper foil) is subjected to reduction treatment using a reduction treatment liquid. By converting a part of copper oxide to cuprous oxide (cuprous oxide) by reduction treatment, fine irregularities composed of acicular crystals and/or plate-like crystals composed of a copper complex compound containing copper oxide and cuprous oxide are formed on the surface of the copper foil. can be formed in This reduction treatment may be performed by bringing the oxidation treatment copper foil into contact with the reduction treatment solution. At this time, increasing the amount of dissolved oxygen in the reduction treatment solution forms a roughened surface of the arithmetic mean curve Spc of peaks of 1300 mm ^-1 or less. It is desirable to do It is thought that by increasing the amount of dissolved oxygen, it is possible to balance the oxidizing effect by dissolved oxygen and the reducing power by the reducing agent, thereby realizing the above Spc. Examples of methods for increasing the amount of dissolved oxygen in the reduction treatment liquid include a method of immersing the oxidation treatment copper foil while stirring the reduction treatment liquid, and a method of spraying the reduction treatment liquid on the oxidation treatment copper foil with a shower. Particularly preferred is a method of spraying the reducing treatment liquid with a shower in that a desired Spc can be easily achieved. In this case, the time for spraying the reducing treatment liquid with the shower may be as short as 2 to 60 seconds. Preferably it is 5 to 30 seconds. In addition, a preferable reducing treatment liquid is an aqueous solution of dimethylamine borane, and it is preferable that this aqueous solution contains dimethylamine borane at a concentration of 10 to 40 g/L. Further, the aqueous solution of dimethylamine borane is preferably adjusted to pH 12 to 14 using sodium carbonate and sodium hydroxide. The temperature of the aqueous solution at this time is not particularly limited, and may be room temperature. In this way, it is preferable to wash and dry the copper foil which performed the reduction process with water.

(3) Anti-rust treatment

If desired, a rust-preventive process may be performed on the copper foil after the roughening treatment to form a rust-preventive layer. Examples of the anti-rust layer include an inorganic anti-rust layer using an inorganic component, an organic anti-rust layer using an organic component, and a combination thereof. A preferable inorganic antirust layer contains one or more elements, such as zinc, tin, nickel, cobalt, molybdenum, tungsten, titanium, and chromium. Preferred organic anti-corrosive layers are those containing a triazole compound, more preferably benzotriazole, carboxybenzotriazole, methylbenzotriazole, aminotriazole, nitrobenzotriazole, hydroxybenzotriazole, and chlorobenzotriazole. sol, ethylbenzotriazole, naphthotriazole, or any combination thereof.

(4) Silane coupling agent treatment

According to request, a silane coupling agent process may be performed on the copper foil after a roughening process, and a silane coupling agent layer may be formed. Thereby, moisture resistance, chemical resistance, adhesiveness with an adhesive etc. can be improved. The silane coupling agent layer can be formed by appropriately diluting and applying the silane coupling agent and drying it. Examples of the silane coupling agent include epoxy functional silane coupling agents such as 4-glycidylbutyltrimethoxysilane and 3-glycidoxypropyltrimethoxysilane, or 3-aminopropyltriethoxysilane, N-2( Aminoethyl) 3-aminopropyltrimethoxysilane, N-3-(4-(3-aminopropoxy)butoxy)propyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimeth An amino functional silane coupling agent such as toxysilane, or a mercapto functional silane coupling agent such as 3-mercaptopropyltrimethoxysilane, or an olefin functional silane such as vinyltrimethoxysilane or vinylphenyltrimethoxysilane. A coupling agent, or an acrylic functional silane coupling agent such as 3-methacryloxypropyltrimethoxysilane, or an imidazole functional silane coupling agent such as imidazole silane, or a triazine functional silane coupling agent such as triazinesilane, etc. can be heard

In addition, you may perform both the above-mentioned rust prevention process and the above-mentioned silane coupling agent process.

comrade Laminate

It is preferable that the roughening process copper foil of this invention is used for manufacture of the copper clad laminated board for printed wiring boards. That is, according to the preferable aspect of this invention, the copper clad laminated board provided with the said roughening process copper foil or the copper clad laminated board obtained using the said roughening process copper foil is provided. This copper clad laminated board comprises the roughening process copper foil of this invention, and the resin layer formed by adhering to the roughening process surface of this roughening process copper foil. The roughening-treated copper foil may be provided on one side of the resin layer, or may be provided on both sides. The resin layer contains a resin, preferably an insulating resin. The resin layer is preferably a prepreg and/or a resin sheet. Prepreg is a general term for composite materials in which a synthetic resin is impregnated into substrates such as synthetic resin plates, glass plates, glass woven fabrics, glass non-woven fabrics, and paper. Preferable examples of the insulating resin include epoxy resins, cyanate resins, bismaleimide triazine resins (BT resins), polyphenylene ether resins, and phenol resins. Moreover, as an example of the insulating resin which comprises a resin sheet, insulating resins, such as an epoxy resin, a polyimide resin, and a polyester resin, are mentioned. In addition, the resin layer may contain filler particles made of various inorganic particles such as silica and alumina from the viewpoint of improving insulation. Although the thickness of the resin layer is not particularly limited, it is preferably 1 to 1000 μm, more preferably 2 to 400 μm, still more preferably 3 to 200 μm. The resin layer may be composed of a plurality of layers. Resin layers, such as a prepreg and/or a resin sheet, may be provided in the roughening process copper foil through the primer resin layer previously apply|coated to the copper foil surface.

print wiring board

It is preferable that the roughening process copper foil of this invention is used for preparation of a printed wiring board. That is, according to the preferable aspect of this invention, the printed wiring board provided with the said roughening process copper foil or the printed wiring board obtained using the said roughening process copper foil is provided. The printed wiring board according to this aspect includes a layer configuration in which a resin layer and a copper layer are laminated in this order. In addition, about a resin layer, it is as having mentioned above about a copper clad laminated board. In any case, a known layer structure can be adopted for the printed wiring board. Specific examples of the printed wiring board include a single-sided or double-sided printed wiring board obtained by adhering the roughened copper foil of the present invention to one or both surfaces of a prepreg to form a cured laminate, and then forming a circuit, a multilayer printed wiring board obtained by multilayering these, etc. can be heard Moreover, as another specific example, the flexible printed wiring board which forms the roughening process copper foil of this invention on a resin film, and forms a circuit, COF, TAB tape, etc. are mentioned. As another specific example, after forming a copper foil (RCC) with a resin in which the above-described resin layer is applied to the roughened copper foil of the present invention, and laminating the resin layer on the above-described printed circuit board as an insulating adhesive layer, A build-up wiring board in which a circuit is formed by a method such as a modified semi-additive (MSAP) method or a subtractive method using the treated copper foil as all or part of the wiring layer, or a semi-additive (SAP) by removing the roughened copper foil. ) method, and direct build-up on wafers in which lamination of copper foil with resin and circuit formation are alternately repeated on semiconductor integrated circuits.

Example

The present invention is explained more specifically with the following examples.

Examples 1 to 10

Production of the roughening process copper foil of this invention was performed as follows.

(1) Production of electrolytic copper foil

As a copper electrolyte solution, a sulfuric acid acidic copper sulfate solution having the composition described below was used, a rotating electrode made of titanium was used as the cathode, and a DSA (dimensional stability anode) was used as the anode, solution temperature was 45°C, and current density was 55 A/dm. ² to obtain an electrolytic copper foil having a thickness of 12 µm. When the maximum height Sz of the deposition surface and electrode surface of this electrolytic copper foil was measured by the method mentioned later, Sz of the precipitation surface was 0.8 micrometer and Sz of the electrode surface was 1.2 micrometer.

<Composition of sulfuric acid copper sulfate solution>

- Copper concentration: 80g/L

- Sulfuric acid concentration: 260g/L

- Bis (3-sulfopropyl) disulfide concentration: 30 mg / L

- Diallyldimethylammonium chloride polymer concentration: 50 mg/L

- Chlorine concentration: 40mg/L

(2) Roughening treatment (oxidation-reduction treatment)

The electrode surface side (Examples 1 to 5) or the precipitation surface side (Examples 6 to 10) of the obtained electrolytic copper foil was subjected to a roughening treatment (oxidation-reduction treatment) by a three-step process described below. That is, the preliminary treatment, oxidation treatment, and reduction treatment shown below were performed in this order.

<Preliminary processing>

The electrolytic copper foil obtained in the above (1) was immersed in an aqueous sodium hydroxide solution having a NaOH concentration of 50 g/L at a liquid temperature of 40°C for 1 minute, subjected to an alkali degreasing treatment, and then washed with water. The electrolytic copper foil subjected to the alkali degreasing treatment was immersed in a sulfuric acid-based aqueous solution having a sulfuric acid concentration of 5% by mass for 1 minute, and then washed with water.

<Oxidation treatment>

Oxidation treatment was performed on the electrolytic copper foil subjected to the preliminary treatment. In this oxidation treatment, the electrolytic copper foil is subjected to hydroxylation at a solution temperature of 70°C, pH = 12, a chlorous acid concentration of 150 g/L, and an N-2-(aminoethyl)-3-aminopropyltrimethoxysilane concentration of 10 g/L. It carried out by making it immerse in sodium solution for the time described in Table 1. In this way, on both sides of the electrolytic copper foil, fine concavities and convexities composed of needle-like crystals and/or plate-like crystals made of a copper complex compound containing copper oxide as a main component were formed.

<Reduction treatment>

A reduction treatment was performed on the sample subjected to the above oxidation treatment. In this reduction treatment, an aqueous solution having a dimethylamine borane concentration of 20 g/L adjusted to pH = 12 using sodium carbonate and sodium hydroxide is applied to the electrode surface side or the precipitation surface side of the electrolytic copper foil on which fine concavities and convexities are formed by the above oxidation treatment, and is 10 g/L. It was carried out by spraying with a shower for seconds. The temperature of the aqueous solution at this time was room temperature. The sample subjected to the reduction treatment in this way was washed with water and dried. By these steps, a part of the copper oxide on one side of the electrolytic copper foil was reduced to form cuprous oxide, and a roughened surface having fine irregularities made of a copper complex compound containing copper oxide and cuprous oxide was obtained. In this way, a roughened copper foil having at least one side a roughened surface provided with fine concavities and convexities composed of acicular crystals and/or plate-like crystals was obtained.

Example 11 (comparison)

A roughening-treated copper foil was produced in the same manner as in Example 2, except that adhesion of the aqueous solution in the reduction treatment was performed by immersing the sample subjected to the oxidation treatment in the aqueous solution instead of using a shower.

Examples 12 and 13 (comparison)

After performing a preliminary treatment in the same manner as in Example 1 (2) on the deposition surface side (Example 12) or electrode surface side (Example 13) of the electrolytic copper foil obtained in the same manner as in Example 1 (1), the conventional The roughening process copper foil was produced by performing oxidation treatment and reduction treatment (oxidation reduction treatment).

<Oxidation treatment>

Oxidation treatment was performed on the electrolytic copper foil. In this oxidation treatment, the electrolytic copper foil is subjected to a liquid temperature of 85 ° C. containing 10 vol% of “PRO BOND 80A OXIDE SOLUTION” and 20 vol% of “PRO BOND 80B OXIDE SOLUTION”, which is an oxidation treatment liquid manufactured by Rohm and Haas Electronic Materials Co., Ltd. It was performed by immersing in an aqueous solution for 5 minutes.

<Reduction treatment>

A reduction treatment was performed on the electrolytic copper foil subjected to the oxidation treatment. In this reduction treatment, the electrolytic copper foil subjected to the above oxidation treatment was subjected to a liquid temperature of 35°C containing 6.7 vol% of "CIRCUPOSIT PB OXIDE CONVERTER 60C" and 1.5 vol% of "CUPOSITZ", which is a reduction treatment liquid manufactured by Rohm and Haas Electronic Materials Co., Ltd. It performed by spraying the aqueous solution at °C in a shower for 10 seconds. The sample subjected to the reduction treatment in this way was washed with water and dried.

Examples 14 and 15 (comparison)

The reduction treatment was performed in the same manner as in Example 12 (in the case of Example 14) or Example 13 (in the case of Example 15), except that the sample subjected to the oxidation treatment was immersed in an aqueous solution for 5 minutes instead of using a shower, Production of the cotton-treated copper foil was performed.

evaluation

About the roughening process copper foil produced in Examples 1-15, the various evaluation demonstrated below was performed.

<maximum height Sz>

The measurement of maximum height Sz in the roughening process surface of the roughening process copper foil was performed based on ISO25178 by the surface property analysis using a laser microscope (VK-X100 made by Keyence Corporation). Specifically, the surface profile of the two-dimensional area|region with an area of 22500 micrometer< ² > in the roughening process surface of the roughening process copper foil was measured by the laser method. The average value when measuring three locations for the same sample was adopted as the value of the maximum height Sz. The measurement of the maximum height Sz of the electrode surface or the deposition surface of the electrolytic copper foil before the roughening treatment in each of the examples described above was also performed in the same procedure as described above.

<The arithmetic mean of the peak of the mountain Spc>

Measurement of the arithmetic mean curve Spc of the peaks in the roughened surface of the roughened copper foil was performed based on ISO25178 by surface property analysis using a laser microscope (VK-X100, manufactured by Keyence Corporation). . Specifically, the surface profile of the two-dimensional region with an area of 100 µm ² on the roughened surface of the roughened copper foil was measured by a laser method. The average value when measuring 10 locations for the same sample was adopted as the arithmetic mean curve Spc of the mountain peak.

<Friction resistance-brightness difference ΔL before and after friction test>

In order to evaluate the friction resistance of the roughened copper foil, the change in brightness L* (in the L*a*b* color system) of the roughened surface of the roughened copper foil before and after the friction test (ΔL) was measured. The measurement of brightness L* was performed based on JIS Z8722:2000 using the spectroscopic color difference meter (SE2000 by Nippon Denshoku Kogyo Co., Ltd.). At this time, the white plate attached to the measuring device was used for the calibration of brightness. This measurement was performed 3 times with respect to the same site|part, and the average value of 3 times measurement value was employ|adopted as the value of lightness L* of the said roughening process copper foil. Next, as a friction test, a plurality of sheets of the produced roughened copper foil are laminated, and while applying a load of 5 kgf / cm 2 from the obtained laminate, one roughened copper foil positioned inside the laminate was pulled out. Lightness L* of the roughened treated surface of the roughened treated copper foil was measured in the same manner as above. The difference (ΔL) in lightness L* before and after the friction test obtained in this way was used as an evaluation index for friction resistance. Specifically, those with a brightness difference ΔL of 10 or less before and after the friction test were judged to be "good", and those exceeding 10 were judged to be "poor".

<Adhesion to resin-peel strength after friction test>

As an insulating resin base material, two sheets of prepreg (manufactured by Panasonic Corporation, MEGTRON4, thickness 100 µm) were prepared and laminated. On this laminated prepreg, the roughened copper foil (pulled out from the laminate while applying a load) subjected to the friction test is laminated so that the roughened surface is in contact with the prepreg, and using a vacuum press, It pressed on conditions of a press pressure of 2.9 MPa, a temperature of 200°C, and a press time of 90 minutes to produce a copper clad laminated board. Next, a test board provided with a linear circuit for peel strength measurement with a width of 3.0 mm was produced on this copper-clad laminate by an etching method. The linear circuit thus formed was peeled from the insulating resin substrate in accordance with JIS C6481-1996, and the peel strength (kgf/cm) was measured.

result

The evaluation results obtained in Examples 1 to 15 were as shown in Table 1. As shown in Table 1, the roughened copper foils produced in Examples 1 to 10 satisfying the conditions of the present invention were excellent in both friction resistance and adhesion to resin after a friction test.

Claims (7)

A roughened copper foil having on at least one side a roughened treated surface comprising fine concavities and convexities composed of acicular crystals and/or plate-like crystals, wherein the roughened treated surface has a maximum height Sz measured in accordance with ISO25178 of 1.5 It is micrometer or less, and the arithmetic mean curve Spc of the mountain peak measured based on ISO25178 is 1300 mm< ^-1 > or less, roughening process copper foil. According to claim 1,
The roughened copper foil whose height of the said needle-like crystal and/or plate-like crystal is 50-400 nm. According to claim 1 or 2,
The roughening process copper foil whose said maximum height Sz is 0.2-1.0 micrometer. According to claim 1 or 2,
The roughening process copper foil whose arithmetic average curve Spc of the said mountain peak is 200-1000 mm< ^-1 >. According to claim 1 or 2,
The roughening process copper foil which is what the said fine unevenness|corrugation was formed through oxidation-reduction treatment. The copper clad laminated board provided with the roughening process copper foil of Claim 1 or 2. The printed wiring board provided with the roughening process copper foil of Claim 1 or 2.