KR20140124402A - Surface-treated electrolytic copper foil, laminate, and printed circuit board - Google Patents

Abstract

A surface treated electrolytic copper foil, a laminated board, and a printed wiring board which are capable of fine pitching and are excellent in adhesion reliability to a resin. A surface treated electrolytic copper foil having a roughened surface roughness (Rz) of a copper foil measured using a contact type roughness meter of not more than 2.0 mu m and a coefficient of condensation (Sku) of an roughness curve of the roughened surface of 2 to 4.

Description

[0001] DESCRIPTION [0002] SURFACE-TREATED ELECTROLYTIC COPPER FOIL, LAMINATE, AND PRINTED CIRCUIT BOARD [0003]

The present invention relates to a surface treated electrolytic copper foil, a laminated board, and a printed wiring board.

Printed circuit boards have made great strides over the past half century, and today they have come to be used in almost all electronic devices. In recent years, as electronic equipment has become more compact and higher in performance, there has been a demand for high-density packaging of mounted components and high frequency signal, and a printed circuit board is required to have finer conductor patterns (high pitch) and high frequency response.

The finer pitch of the conductor pattern with respect to the printed wiring board is better formed as the roughness of the copper foil roughened surface is lower. For this reason, the demand for lowering of the surface of the copper foil-roughened surface has been increased due to recent fine pitching of the conductor pattern.

On the other hand, the copper foil is bonded to the resin to form a laminated board. However, the adhesion reliability with the resin at that time is improved because the anchor effect generated on the roughened surface becomes higher the greater the roughness of the copper foil. This close reliability is considered to be one of important management items for forming a fine pitch, and it is considered that the 90 ° peel strength should be equal to or higher than a certain value (0.6 kg / cm). Another method for evaluating adhesion reliability is to immerse a laminated body with a resin substrate in a high temperature bath at 260 占 폚 to measure the number of swellings occurring on the surface. The swelling number of 0 to 1 / It is a standard of reliability.

Various techniques have been developed for a copper foil which can be made into a fine pitch and which has improved adhesion reliability to a resin. For example, Patent Document 1 discloses a surface area (A) of a two-dimensional region having a surface roughness (Rzjis) of 2.5 mu m or less and a surface area of 6550 mu m measured by a laser method and a surface area Wherein the value of the surface area ratio (B) calculated by the ratio of the area [(A) / (6550)] is 1.25 to 2.50, and the amount of chromium per unit area of the two-dimensional area is 2.0 mg / Wherein the surface-treated copper foil is a surface-treated copper foil.

Japanese Laid-Open Patent Publication No. 2009-105286

As disclosed in Patent Document 1, in the prior art, in order to improve the adhesion reliability with the resin, it has been a major object to pay particular attention to the Rz of the roughened surface of the copper foil and to control it. However, according to the examination by the inventors, it was found that the number of swellings occurred at the interface of adhesion with the above-described resin substrate was different even if the Rz of the roughened surface of the copper foil was controlled to be the same value and the other conditions were the same. For this reason, it has been found that the copper foil in which only the Rz of the roughened surface of the copper foil is controlled is not sufficient for obtaining good adhesion reliability.

The present invention provides a surface-treated electrolytic copper foil, a laminate, and a printed wiring board which can be made into a fine pitch and have excellent adhesion reliability to a resin.

When Rz of the roughened surface is lowered in order to make the conductor pattern of the copper foil finer, the air is gathered at the fine unevenness formed on the copper foil surface at the interface between the copper foil surface and the resin substrate. Since this air is difficult to escape, the air gathered in fine unevenness expands and swells when it is in a high temperature state. As a result of intensive studies, the inventors of the present invention have found that, by using a copper foil having a low coarseness for fine pitching, it is possible to suppress the occurrence of the swelling by imparting a structure to the copper foil surface such that air hardly collects on the surface of the copper foil, It is possible to obtain good adhesion reliability.

In one aspect of the present invention, which is completed on the basis of the above findings, it is preferable that the roughness Rz of the roughened surface Rz of the copper foil measured using a sensory roughness meter is 2.0 占 퐉 or less and the Coulossy number Sku of the roughness curve of the rough surface Is 2 to 4 surface treated electrolytic copper foil.

In one embodiment of the surface treated electrolytic copper foil according to the present invention, the roughness Rz is 0.8 to 1.8 占 퐉.

In another embodiment of the surface-treated electrolytic copper foil according to the present invention, the culosis number (Sku) is 2.5 to 3.5.

In another embodiment of the surface treated electrolytic copper foil according to the present invention, the ratio A / B of the surface area A of the rough surface to the area B obtained when the rough surface is viewed from the plane is 1.2 to 2.0.

In another embodiment of the surface treated electrolytic copper foil according to the present invention, the ratio A / B is 1.3 to 1.9.

In another embodiment of the surface treated electrolytic copper foil according to the present invention, the state fill strength is 0.8 kg / cm or more.

Another aspect of the present invention is a laminated board comprising the surface treated electrolytic copper foil of the present invention and a resin substrate laminated.

According to another aspect of the present invention, there is provided a printed wiring board comprising the laminate of the present invention as a material.

According to the present invention, it is possible to provide a surface-treated electrolytic copper foil, a laminated board, and a printed wiring board which can be formed into a fine pitch and have excellent adhesion reliability to a resin.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an SEM observation image of a roughened surface of a sample of Example 1. FIG.
Fig. 2 is an SEM photograph of the roughened surface of the sample of Comparative Example 1. Fig.

The electrolytic copper foil used in the present invention is useful for an electrolytic copper foil to be used by bonding a resin substrate to produce a laminate and removing the same by etching.

The electrolytic copper foil used in the present invention is a copper foil used for the purpose of improving the peel strength (adhesion reliability) of the copper foil after lamination on the surface of the copper foil to be bonded to the resin substrate, A harmonic treatment for electrodeposition on the bark is performed. Although the electrolytic copper foil has irregularities at the time of manufacture, the convex portions of the electrolytic copper foil are strengthened by roughening treatment to further increase the irregularities.

[Roughness (Rz)]

In the surface treated electrolytic copper foil of the present invention, the roughness Rz of the roughened surface of the copper foil measured using a contact-type roughness meter according to JIS B 0601-1994 is 2.0 占 퐉 or less. If the roughness Rz is more than 2.0 占 퐉, air tends to collect at fine irregularities formed on the surface of the copper foil at the interface between the copper foil surface and the resin substrate, and this air is difficult to escape. For this reason, in a high temperature state, air gathered in fine unevenness expands and swelling occurs. The roughness Rz of the roughened surface measured using a contact type illuminometer is preferably 0.8 to 1.8 占 퐉, more preferably 1.0 to 1.7 占 퐉. This roughness Rz can be controlled by optimizing the processing conditions of the shiny side (S side) of the copper foil and the use of double-side smooth blending.

[Coulosis water (Sku)]

The surface treated electrolytic copper foil of the present invention has a crothosis number (Sku) of the roughness curve of the rough surface in a range of from 2 to 4 (inclusive) from the viewpoint that the "kurtosis" Respectively. The culosis number Sku of the roughness curve indicates the degree of sharpness (roundness degree) of the unevenness in the rough surface of the copper foil. As the culosis number Sku becomes smaller, the unevenness becomes curved with roundness, (Sku) becomes larger, the irregularities become sharp curves. The culosis number Sku of the roughness curve is an index of the degree of sharpness of the unevenness in the measurement of the three-dimensional surface roughness by the non-contact type roughness meter based on the ISO 25178 draft, and is represented by the following formula, The height of the unevenness (mountain) is obtained by dividing the height of the mountain Z (x) at the reference length lr by the fourth power of the square root mean square roughness (Rq) shown below.

Fourth mean of the height of the mountain at the reference length lr:

{(1 / lr) × ∫Z 4 (x) dx ( stage 0 is integral to the integrated value of from lr)}

Square root mean square roughness (Rq):

Rq: √ {(1 / lr) × ∫Z ² (x) dx (Integral integral value from 0 to 1r)}

Coulosis number of illumination curve (Sku):

^{Sku = (1 / Rq 4)} × {(1 / lr) × ∫Z 4 (x) dx ( stage 0 is integral to the integrated value of from lr)}

As described above, the roughness (Sku) of the roughness curve increases as the sharpness and sharpness of the unevenness of the rough surface of the copper foil become worse. Further, the steepness of the irregularities and the sharpness of the irregularities increases the variation in the size of the irregularities existing on the copper foil rough surface. Therefore, by controlling the Couloty number Sku of the roughness curve indicating the control of the shape of the irregularities, it is possible to further suppress the variation in the size of the irregularities existing on the copper foil rough surface. By suppressing the variation in the size of the irregularities present on the surface of the copper foil in this way, even if the pitch is made fine, the air hardly collects on the surface of the copper foil. Therefore, the occurrence of swelling caused by the expansion of air gathered in the unevenness at a high temperature state is suppressed, whereby good adhesion reliability with the resin substrate can be obtained. If the roughness coefficient Sku of the roughness curve of the rough surface is less than 2, a sufficient adhesion force with the resin can not be maintained, and if it is more than 4, there arises a problem that swelling occurs after heating as described above. The Coulthis number (Sku) of the roughness curve is preferably 2.5 to 3.7, more preferably 2.5 to 3.5, and still more preferably 2.4 to 3.4. The culosis number (Sku) can be controlled by optimizing the coarsening treatment conditions of the copper foil.

[Surface area ratio A / B]

In the surface treated electrolytic copper foil of the present invention, the ratio A / B of the surface area A of the roughened surface (roughened surface) to the area B obtained when the roughened surface is viewed in plan is preferably 1.2 to 2.0. Here, the surface area A is a surface area (three-dimensional area) when a two-dimensional area in a predetermined range is measured by a laser method, and an area B obtained when the rough surface is viewed in a plane indicates an area of the two- The surface area ratio A / B is a substitute for the contact area between the surface treated electrolytic copper foil and the resin substrate. If the ratio is less than 1.2, adhesion to the resin may not be secured sufficiently. If the ratio is more than 2.0, There is a possibility of causing a problem that swelling occurs later. The surface area ratio A / B is more preferably 1.3 to 1.9. The surface area ratio A / B can be controlled by optimizing the roughening treatment conditions of the copper foil. For example, when W is added to the copper plating solution, the surface area ratio A / B increases. Also, when the current density is increased in the copper roughening treatment, the surface area ratio A / B becomes larger. When the current density is lowered, the surface area ratio becomes smaller. Thus, the surface area ratio A / B can be controlled to 1.2 to 2.0.

[State Peel Strength]

The surface treated electrolytic copper foil of the present invention has a good state peel strength as described above. Specifically, the surface-treated electrolytic copper foil of the present invention preferably has a state fill strength measured according to JIS C 5016 of 0.8 kg / cm or more. The state fill strength is more preferably 0.9 kg / cm or more.

[Swelling of high temperature bath]

As described above, the surface-treated electrolytic copper foil of the present invention is satisfactorily suppressed from swelling in hot and hot baths. Specifically, the surface-treated electrolytic copper foil of the present invention has a fine pitch circuit as a conductor pattern, and when the resin substrate is adhered with a roughened surface, the amount of occurrence of swelling after immersing in a high temperature bath at 260 占 폚 for 1 minute, 1 / m < 2 >.

In the method for producing a surface-treated electrolytic copper foil of the present invention, first, an electrolytic copper foil is produced. The electrolytic copper foil to be used in the present invention is an electrolytic copper foil having high high temperature elongation with pinholes inhibited, which is a useful property as a green.

The electrolytic copper foil used in the present invention is produced by electrolysis using a sulfuric acid-containing copper sulfate electrolytic solution. By adjusting the concentration of the glue in the electrolytic solution to 0.5 ppm or less, preferably 0.01 to less than 0.2 ppm, and more preferably by adding the adjusted amount of chloride ion and adjusting other electrolytic conditions such as the electrolyte temperature and sulfuric acid concentration Whereby an electrolytic copper foil having no pinholes and high elongation at high temperature can be obtained. The amount of the incorporation of the glue into the electrolytic copper foil produced by using the electrolytic solution is reduced and the annealing (recrystallization) of the crystal is promoted at the high temperature treatment, and as a result, the elongation at high temperature is increased.

The composition and electrolysis conditions of the electrolytic solution used in the present invention in the case of adding chloride ion are as follows.

(A) Electrolyte composition:

Cu: 50 to 120 g / l

H ₂ SO ₄ : 20-200 g / l, preferably 40-120 g / l

Chloride ion (Cl ^- ): 20 to 100 ppm (mg / l)

Glue: not more than 0.5 ppm (mg / l), preferably not more than 0.01 to 0.2 ppm (mg / l)

(B) Electrolytic condition:

Electrolyte temperature: 20 to 70 캜, preferably 40 to 60 캜

Current density: 20 to 150 A / dm 2

Anode: Pb

If the glue concentration exceeds 0.5 ppm, the elongation at high temperature hardly increases. It is also necessary to add a minimum amount of glue to prevent pinholes and the like. Glue addition in an amount less than 0.01 to 0.2 ppm (mg / l) is preferred.

The sulfuric acid concentration is preferably 20 to 200 g / l, preferably 40 to 120 g / l. If it is less than 20 g / l, the conductivity of the electrolytic solution decreases and the electrolytic cell voltage increases. If it exceeds 200 g / L, the production of a high-temperature-elongated copper foil becomes increasingly difficult, and corrosion of the equipment tends to occur.

Preferably, the chloride ion is added in an amount of 20 to 100 ppm (mg / l). Outside this range, the basic properties (electrostatic force, roughness, etc.) of the electrolytic copper foil are not fixed. Chloride ions are added in the form of hydrochloric acid, salt, potassium chloride and the like.

The temperature of the electrolytic solution is preferably 20 to 70 캜, preferably 40 to 60 캜. When the electrolytic solution temperature is lowered, a high-temperature-elongated copper foil can be produced even if the glue concentration is high. Below 20 캜, the conductivity of the electrolytic solution decreases, and the electrolytic cell voltage increases. When it exceeds 70 캜, the production of high-temperature-elongated copper foil becomes increasingly difficult, and the energy cost also increases.

The current density range is from 20 to 150 A / dm 2 in order to produce an electrolytic copper foil in a stable and practically acceptable time.

Hereinafter, an example of a method of controlling the number of culosis (Sku) in green bean leaves is shown:

≪

The amine compound [tertiary amine compound] is added in an amount of 1 to 10 ppm and the SPS [bis (3-sulfopropyl) disulfide disodium] is 1 to 50 ppm, 1 to 50 ppm, so that the rough surface is smoothened (the irregularities do not become sharp). Thereby, the shape of the coarsened particles on the surface after the subsequent coarsening treatment and coated copper plating is rounded. In this manner, the cul tosyl water (Sku) can be made smaller than a general electrolytic copper foil (for example, when the fresh foil is made of copper, sulfuric acid, Cl, or an electrolyte in which glue is added).

Further, the following compounds are used as tertiary amine compounds.

[Chemical Formula 1]

(Will be In the formula, R ₁ and R ₂ are selected from the group consisting of a hydroxyl group, an ether group, an aryl group, an aromatic-substituted alkyl group, unsaturated hydrocarbon group, an alkyl group. In the embodiment to be described later for example, R ₁ and R ₂ are All were methyl groups.)

The compound used in Examples described later can be obtained, for example, by mixing a predetermined amount of Deconar Ex-314 manufactured by Nagase ChemteX Corporation with dimethylamine and conducting a reaction at 60 ° C for 3 hours.

Next, the surface of the electrolytic copper foil is roughened. As the harmonization processing, for example, the following conditions may be employed. In the present invention, the roughened surface of the electrolytic copper foil is roughened.

· When the bark is a common electrolytic copper foil (eg when the bark is made of copper, sulfuric acid, Cl, glue-added electrolyte)

[Copper conditioning treatment conditions]

Cu: 5 to 50 g / l

H ₂ SO ₄ : 10 to 100 g / l

· Additional elements (any of conditions 1 to 4)

(Condition 1)

As: 0.01 to 20 mg / l (ppm)

W: 0.01 to 10 mg / l (ppm)

(Condition 2)

Mo: 0.01 to 5 mg / l (ppm)

(Condition 3)

Mo: 0.01 to 5 mg / l (ppm)

As: 0.01 to 5 mg / l (ppm) and / or W: 0.01 to 5 mg / l (ppm) and / or Co: 0.01 to 0.5 mg /

(Condition 4)

As: 0.01 to 20 mg / l (ppm)

W: 0.01 to 10 mg / l (ppm)

Co: 0.01 to 0.5 mg / l (ppm)

Liquid temperature: room temperature (20 ° C) to 50 ° C

Current density: 5 ~ 120 A / dm2

Time: 1 to 30 seconds

· When the fresh leaves are double-sided flat foil (eg, copper foil, sulfuric acid, Cl, glue, SPS, copper foil, etc.) When the electrolyte solution is prepared by adding an amine compound)

[Copper conditioning treatment conditions]

Cu: 5 to 50 g / l

H ₂ SO ₄ : 10 to 100 g / l

· Additional elements (any of conditions 1 to 4)

(Condition 1)

As: 0.01 to 5 mg / l (ppm)

W: 0.01 to 5 mg / l (ppm)

(Condition 2)

Mo: 0.01 to 3 mg / l (ppm)

(Condition 3)

Mo: 0.01 to 3 mg / l (ppm)

As: 0.01 to 5 mg / l (ppm) and / or W: 0.01 to 5 mg / l (ppm) and / or Co: 0.01 to 1 mg /

(Condition 4)

W: 0.01 to 5 mg / l (ppm) and / or Co: 0.01 to 1 mg / l (ppm)

Liquid temperature: room temperature (20 ° C) to 50 ° C

Current density: 5 ~ 130 A / dm2

Time: 1 to 30 seconds

Hereinafter, an example of a control method of the Coulos number (Sku) in the copper roughening treatment is shown:

≪ Copper conditioning treatment condition >

In the copper-coining solution, both the As and the W are added, or Mo is added to round the shape of the coarsely grained particles. In this way, the culosis number Sku can be reduced.

In addition, in the copper roughening treatment liquid, the shape of the coarsened particles can be sharpened (the ends of the particles are sharp) by adding Co or by adding W alone (without As). In this way, the culosis number Sku can be increased.

Further, by lowering the liquid temperature (for example, lower than 20 ° C and lower than 25 ° C), the shape of the coarsened particles can be sharpened (the ends of the particles are sharp). In this way, the culosis number Sku can be increased.

After the roughening treatment, thin copper plating is performed as a coating layer for preventing the particles from falling off. For example, the following conditions can be adopted.

[Coating condition of coated copper foil layer]

Cu: 30 to 100 g / l

H ₂ SO ₄ : 10-200 g / l

Temperature: Room temperature ~ 75 ℃

Current density: 5 to 65 A / dm 2

Time: 1 to 30 seconds

Hereinafter, an example of a method of controlling the culosis number (Sku) in the coated copper plating process is shown:

≪ Coated copper plating conditions >

By making the current density higher (for example, larger than 60 A / dm 2), the shape of the coarsened particles can be sharpened (the ends of the particles are sharp). In this way, the culosis number Sku can be increased.

It is preferable to carry out a treat treatment in which at least one single metal layer or alloy layer selected from Cu, Cr, Ni, Fe, Co and Zn is formed on the roughened surface. Examples of the alloy plating include Cu-Ni, Cu-Co, Cu-Ni-Co, Cu-Zn and others. This treat treatment determines the final property of the copper foil and also acts as a barrier.

Further, the heat-resistant layer or rust-preventive layer may be formed on the roughened surface by a single body of nickel, cobalt, copper, zinc, or an alloy, or the surface may further be subjected to chromate treatment, silane coupling treatment or the like. A heat resistant layer or a rust preventive layer may be formed of a single body of nickel, cobalt, copper, zinc or an alloy, and the surface thereof may be subjected to a treatment such as a chromate treatment or a silane coupling treatment. That is, at least one layer selected from the group consisting of a heat resistant layer, a rust prevention layer, a chromate treatment layer and a silane coupling treatment layer may be formed on the surface (roughened surface) of the roughened treatment layer, , A rust-preventive layer, a chromate treatment layer, and a silane coupling treatment layer may be formed. The heat resistant layer, rust preventive layer, chromate treatment layer and silane coupling treatment layer described above may be formed of a plurality of layers (for example, two or more layers, three or more layers, etc.).

The surface treated electrolytic copper foil of the present invention can be bonded to the resin substrate from the roughened surface side to produce a laminate. The resin substrate is not particularly limited as long as it has properties that can be applied to a printed wiring board and the like. For example, for a rigid PWB, a paper base phenol resin, a paper base epoxy resin, a synthetic fiber base epoxy resin, An epoxy resin, a glass / glass nonwoven fabric composite base material epoxy resin, a glass cloth base epoxy resin and the like can be used, and a polyester film, a polyimide film, a liquid crystal polymer (LCP) film and the like can be used for FPC.

In the case of the rigid PWB, the prepreg is prepared by impregnating a base material such as a glass cloth with resin and curing the resin to a semi-hardened state. The copper foil may be superimposed on the prepreg from the opposite side of the coating layer and heated and pressed. In the case of FPC, a laminate can be manufactured by laminating the laminate to a copper foil under a high temperature and high pressure without using an adhesive on a base material such as a polyimide film or by applying a polyimide precursor, drying and curing have.

The laminate of the present invention can be used for various printed wiring boards (PWB), and is not particularly limited. For example, from the viewpoint of the number of layers of the conductor pattern, it is applied to one side PWB, double side PWB, And can be applied to the rigid PWB, the flexible PWB (FPC), and the rigid flex PWB from the viewpoint of the kind of the insulating substrate material.

Example

As examples 1 to 6 and comparative examples 1 to 5, green beans were produced according to the production conditions shown in Table 1, followed by roughening treatment according to the production conditions shown in Table 2, , Copper plating was performed on the roughened surface to form a roughened surface, respectively. In Tables 1 to 3, the treatment surface M represents a mat surface (precipitation surface of copper), and the treatment surface S represents a shiny surface.

Various evaluations were carried out for each of the samples prepared as described above and the comparative example as follows.

Stylus illumination;

The measurement was made using a Surfcorder SE-3C contact-type illuminometer manufactured by Kosaka Laboratory Co., Ltd.

Surface area ratio (A / B);

The surface area of the rough surface was measured by a laser microscope. Using the Olympus LEXT OLS 4000, the three-dimensional surface area A in the area B (equivalent to 66524 mu m in actual data) corresponding to 257.9x257.9 mu m of the harmoniously processed surface was measured to obtain the three-dimensional surface area A / the two- A / B). ≪ tb > < TABLE > The measurement environment temperature was 23 to 25 ° C.

Coulosis water (Sku);

Using a LEXT OLS 4000 three-dimensional surface profile measuring apparatus manufactured by Olympus, an area of 257.9x257.9 占 퐉 on the roughened surface of the test material was measured with a resolution of 0.12 占 퐉 in plane and 0.01 占 퐉 in height. The measurement environment temperature was 23 to 25 ° C.

State peel strength;

According to JIS C 5016 (8.1.6 Measurement (1) Method A (90 占 peeling method)), the state peel strength was measured with an Autograph 100 of a tensile tester.

High temperature bath swelling;

The copper foil was laminated and bonded to a glass cloth base epoxy resin plate, and a fine pitch circuit was formed on the copper foil by etching (ferric chloride aqueous solution) to produce a laminate. Subsequently, the laminate was immersed for 1 minute in a hot bath at 260 占 폚, and the number of swellings occurred on the surface was measured and converted into the number per 1 m2.

The evaluation results are shown in Table 4.

(Evaluation results)

Examples 1 to 6 all had good adhesion reliability, and no swelling occurred even when they were immersed in a high temperature bath.

In Comparative Examples 1 to 4, the roughness Rz was not more than 2.0 占 퐉. However, since the crothosis number Sku of the roughness curve of the roughened surface was outside the range of 2 to 4, the adhesion reliability was poor, There was a lot of swelling.

Fig. 1 shows SEM observation photographs of the roughened surface of the sample of Example 1. Fig. Fig. 2 shows SEM observation photographs of the roughened surface of the sample of Comparative Example 1. Fig.

Claims (8)

A surface treated electrolytic copper foil having a roughened surface roughness (Rz) of a copper foil measured using a contact type roughness meter of not more than 2.0 mu m and a coefficient of condensation (Sku) of an roughness curve of the roughened surface of 2 to 4. The method according to claim 1,
Wherein the roughness (Rz) is 0.8 to 1.8 占 퐉. 3. The method according to claim 1 or 2,
The surface-treated electrolytic copper foil according to any one of claims 1 to 3, wherein the cu ttoosyl water (Sku) is 2.5 to 3.5. 4. The method according to any one of claims 1 to 3,
A surface treated electrolytic copper foil having a ratio A / B of the surface area A of the rough surface to an area B obtained when the rough surface is viewed from a plane is 1.2 to 2.0. 5. The method of claim 4,
Wherein the ratio A / B is 1.3 to 1.9. 6. The method according to any one of claims 1 to 5,
A state - treated electrolytic copper foil having a state peel strength of 0.8 kg / cm or more. A laminated board comprising the surface treated electrolytic copper foil according to any one of claims 1 to 6 and a resin substrate laminated. A printed wiring board comprising the laminate according to claim 7 as a material.

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