KR101574475B1 - Surface-treated copper foil, and copper-clad laminate obtained using surface-treated copper foil - Google Patents

Abstract

The object of the present invention is to provide a copper foil having good adhesion with an insulating resin base material and having a good etching performance equivalent to that of a non-roughened copper foil, as compared with a non-roughened copper foil. In order to achieve this object, in a surface-treated copper foil obtained by roughening the surface of a copper foil, the surface of the copper foil is roughened with needle-like or plate-like fine irregularities containing a copper composite compound having a maximum length of 500 nm or less And a surface-treated copper foil or the like having a roughened surface. It is preferable that the copper complex compound has a composition of 50 to 99% of copper oxide and a remaining amount of copper oxide and an impurity.

Description

TECHNICAL FIELD [0001] The present invention relates to a copper-clad laminate obtained by using a surface-treated copper foil and a surface-treated copper foil, and a copper clad laminate comprising the copper clad laminate,

The present application relates to a copper clad laminate obtained by using a surface treated copper foil and a surface treated copper foil. In particular, the present invention relates to a surface treated copper foil wherein the surface of the copper foil is roughened with needle-like or plate-like fine irregularities containing a copper complex compound.

In general, the copper foil that circulates in the market is often used in circuit-forming applications of printed wiring boards. In order to improve the adhesion to the insulating resin base material, copper foils serving as bonding surfaces Have formed a cotton shape. As the roughening effect that exhibits the anchor effect, "adhesion of fine copper particles" as disclosed in Patent Document 1 and "formation of concave and convex portions by etching" as disclosed in Patent Document 2 have been performed.

In recent years, there has been a great demand for formation of a fine pitch circuit. As a result of the remarkable advances in the production technology of printed wiring boards, the use of non-roughened copper foil as disclosed in Patent Documents 3 and 4 It was.

In order to provide a copper clad laminate for a printed circuit in which a copper foil and a laminate substrate are firmly adhered to each other by a strong and highly reactive adhesive agent, Patent Document 3 discloses a copper clad laminate having a copper foil laminated on one side or both sides of a laminate substrate 1. A laminate comprising: a. On the above copper foil, the general formula QRSiXYZ ... (1) wherein Q represents a functional group which reacts with the following resin composition, R represents a bonding group connecting Q and Si atoms, and X, Y and Z represent a hydrolyzable group or a hydroxyl group bonded to the Si atom ) Or a silane coupling agent represented by the general formula T (SH) n (2) (wherein T is an aromatic ring, an aliphatic ring, a heterocyclic ring, an aliphatic chain, and n is an integer of 2 or more) b. (2) a peroxide-curable resin composition of diallyl phthalate, epoxy acrylate or epoxy methacrylate and oligomers thereof, (3) a copolymer of ethylene butyl (meth) acrylate, (4) a resin composition of an olefin copolymer containing a glycidyl group, (5) a resin composition comprising a polyvinyl butyral having a side chain containing an unsaturated group (6) a resin composition comprising a polyvinyl butyral resin and an amino resin having a spiroacetic acid ring and an epoxy resin, wherein the resin composition is bonded to the laminated substrate, Laminated board for a printed circuit characterized in that it is directly bonded to the laminated substrate. And the like are adopted.

Patent Document 4 discloses a surface treated copper foil which does not contain chromium in the surface treatment layer and is processed into a printed wiring board to provide a surface treated copper foil excellent in the peel strength of subsequent circuits and the chemical resistance deterioration rate of the peel strength, "A surface treated copper foil having a surface treatment layer formed on an abutting surface of a copper foil to be used for producing a copper clad laminate opposite to an insulating resin base, wherein the surface treatment layer is formed by adhering a zinc component to the abutting surface of a copper foil , A surface-treated copper foil obtained by attaching a high-melting-point metal component having a melting point of 1400 占 폚 or more and adhering a carbon component. "Among these, the" It is preferable to use a material having a surface roughness Rzjis of not more than 2.0 탆 without performing a roughening treatment.

Such a non-roughened copper foil has no unevenness used for roughening on the bonding surface with the insulating resin base material. Therefore, there is no need to provide an overetching time for removing an anchor shape (concavity and convexity) in a state of being buried in the insulating resin base material when the copper foil is etched to form a circuit. Therefore, it is very useful in forming a fine pitch circuit having a good etch factor.

Japanese Patent Application Laid-Open No. 05-029740 Japanese Patent Application Laid-Open No. 2000-282265 Japanese Patent Application Laid-Open No. 09-074273 Japanese Patent Application Laid-Open No. 2008-297569

However, since the non-roughened copper foil has no anchor shape (irregular shape) in a state of being embedded in the insulating resin base material side, the adhesion of the roughened copper foil to the insulating resin base material is Compared with the conventional method.

Therefore, in the market, it is possible to provide a copper foil having good adhesion to an insulating resin base material as compared with the adhesion of an uncured copper foil to an insulating resin base material, There has been a demand for a copper foil having good etching performance.

Therefore, the inventors of the present invention have conducted intensive studies, and as a result, by employing the copper foil shown below, an anchor shape (concave-convex shape) in a state of being embedded in the insulating resin base material side can be provided so that good adhesion with the insulating resin base material can be provided . Hereinafter, the surface treated copper foil according to the present application will be described.

Surface-treated copper foil: The surface-treated copper foil according to the present application is a surface-treated copper foil obtained by roughening the surface of a copper foil, characterized in that a surface of the copper foil is coated with a needle- And a roughed surface layer formed by plate-like fine irregularities. Hereinafter, the "needle-like or plate-like fine irregularities containing the copper complex compound" will be simply referred to as "fine irregularities containing the copper complex compound".

The fine irregularities including the copper complex compound of the roughed surface layer of the surface-treated copper foil according to the present application were measured from the surface of the roughened surface layer at a tilt angle of 45 占 and a tensile strength of 50,000 times or more of the sample using a scanning electron microscope The maximum length observed is 150 nm or less.

The fine irregularities including the copper composite compound of the surface treated copper foil according to the present application are characterized in that when the total area of each peak area of Cu (I) and Cu (II) when analyzed by XPS is 100%, Cu I) occupying area ratio of the peak is preferably 50% or more.

The fine irregularities including the copper composite compound of the surface treated copper foil of the present application application contain copper oxide and copper oxide.

In the fine unevenness containing the copper composite compound of the surface treated copper foil according to the present application, the specific surface area measured by adsorbing krypton is preferably 0.035 m ² / g or more.

It is preferable that the surface of the roughed surface layer of the surface treated copper foil according to the present application has a lightness whose brightness L ^* of the L ^* a ^* b ^* color system is 25 or less.

Copper-clad laminate: The copper clad laminate according to the present application is characterized by being obtained by using the above-mentioned surface-treated copper foil.

The surface-treated copper foil according to the present application forms a roughened surface with " fine irregularities containing a copper composite compound having a maximum length of 500 nm or less ". The roughened surface is on the outermost surface of the copper foil, and the macroscopic concavo-convex shape of the order of 탆 provided by the bonding surface of the copper foil with the insulating resin base remains unchanged. As a result, good adhesion can be secured as compared with the adhesion of the uncooked copper foil to the insulating resin base material.

Fig. 1 is a scanning electron microscopic observation (a sample with an immersion time of 2 minutes in the oxidation treatment in Example 1) for explaining the surface roughening shape of the surface treated copper foil according to the present application. Fig.
Fig. 2 is a scanning electron microscopic observation view for showing different roughening shapes depending on the roughening target portion between the electrode surface and the deposition surface of the electrolytic copper foil in the surface treatment copper foil according to the present application (Example 1 2 minutes of the immersion time of the oxidation treatment in the sample).
3 is a scanning electron microscopic observation of the cross-section of the roughened layer of the surface-treated copper foil according to the present application (a sample with an immersion time of 2 minutes in the oxidation treatment in Example 1).
Fig. 4 is a scanning electron microscopic observation view of the roughened treatment form of the comparative sample in the comparative example from the surface. Fig.
5 is a scanning electron microscopic observation view of the roughed surface of the comparative sample in the comparative example.

Hereinafter, the "shape of the surface treated copper foil" and the "shape of the copper clad laminate" relating to the present application will be described.

Surface treated copper foil: The surface treated copper foil according to the present application is a surface treated copper foil obtained by roughening the surface of a copper foil. The surface-treated copper foil is characterized in that fine copper foils having a maximum length of 500 nm or less And a roughened surface treatment layer formed of unevenness.

Either electrolytic copper foil or rolled copper foil can be used for the copper foil used in the production of the surface treated copper foil according to the present application. Further, the thickness of the copper foil is not particularly limited, and is generally regarded as a thickness of 200 mu m or less. Further, the surface treated copper foil according to the present application is applied to both cases of roughening one surface and roughening both surfaces.

The roughened surface of the surface-treated copper foil according to the present application is formed by forming a "fine unevenness containing copper compound" containing copper oxide on the surface of the copper foil and reducing the part of the copper oxide to copper oxide , And is preferably roughened with " fine irregularities containing a copper composite compound having a maximum length of 500 nm or less " including copper oxide and copper oxide. Here, the "maximum length of 500 nm or less" refers to the maximum value of the "fine irregularities including the copper composite compound" observed on the roughened surface of the surface treated copper foil by a scanning electron microscope of field emission type. The maximum value of the shape of the " fine unevenness including the copper complex compound " is the maximum value of the shape of the roughened surface of the copper foil, which is formed on the surface of the copper foil, Quot; refers to the length of the needle-like or plate-like shape extending from the surface of the copper foil. From the viewpoint of enhancing the adhesion between the surface treated copper foil and the insulating layer constituting material in relation to the present application, the maximum length is more preferably 400 nm or less, and still more preferably 300 nm or less. This maximum length may also be referred to as " maximum length 1 " hereinafter.

The "fine irregularities including the copper composite compound" constituting the roughened layer of the surface-treated copper foil according to the present application can be obtained by subjecting the surface of the roughened layer to an electric field radiation type Quot; maximum length of micro concavo-convex including copper composite compound " when observed with a scanning electron microscope of a scanning electron microscope at a magnification of 50000 times or more and in a planar state (inclination angle of the sample at the time of observation with a scanning electron microscope) And is preferably 150 nm or less. 1 (b) and 1 (b) show that when the roughened surface (Fig. 1 (a)) of the double-side smooth electrolytic copper foil is roughened with "fine irregularities containing a copper complex compound" . 1 (c) shows an observation image obtained by enlarging the surface of Fig. 1 (b) by 50000 times. From the viewpoint of enhancing the adhesion between the surface treated copper foil and the insulating layer constituting material relating to the present application, the maximum length is more preferably 100 nm or less. This maximum length may also be referred to as " maximum length 2 " hereinafter.

For example, when the precipitated surface of the electrolytic copper foil before roughening as shown in FIG. 1A is measured by a non-contact three-dimensional surface shape / roughness meter (model: New-View 6000) manufactured by Zygo Corporation, 1.6 nm, and Rz = 26 nm. The electrolytic copper foil after the surface roughening treatment shown in Fig. 1 (b) is roughened with the precipitated surface of the electrolytic copper foil with the " fine irregularities including the copper complex compound " When the surface is measured in the same manner, Ra = 2.3 nm and Rz = 39 nm, and it can be understood that roughening is carried out in the order of nm. In addition, Fig. 2 shows different roughening shapes depending on the electrode surface of the electrolytic copper foil and the roughening part of the deposition surface. 2 will be described in detail in an embodiment.

3 shows a cross-section of fine irregularities including the copper complex compound formed by roughening at this time. In this cross-sectional view, the average thickness from the surface of the copper foil is 400 nm or less although there is a certain variation in the thickness of the roughed surface layer formed by the dense unevenness including the copper complex compound. 3, the average thickness of the roughed surface layer is 250 nm. As a result of a number of tests conducted by the inventors of the present application, it was found that when the average thickness of the roughened surface layer is in the range of 100 nm to 350 nm, it is possible to provide "good adhesion to the insulating resin substrate or roughened copper foil or more" .

Subsequently, the components constituting the fine irregularities including the copper complex compound were subjected to state analysis using X-ray photoelectron spectroscopy (hereinafter referred to simply as "XPS"). As a result, the presence of "Cu (0)", "Cu (II)", "Cu (I)" and "-COO group" was confirmed. Since the presence of the "-COO group" is confirmed here, it is considered that there is a high possibility that "copper carbonate" is contained. Therefore, it is considered that the impurities contained in the copper complex compound described below include copper carbonate.

When the copper complex compound of the surface-treated copper foil according to the present application is analyzed using the above-described XPS, peaks of Cu (I) and Cu (II) can be separated and detected. When the copper complex compound is analyzed with this XPS, Cu (0) peaks may be observed overlapping in the shoulder portion of the large Cu (I) peak, so that the Cu (I) peak including this shoulder portion is regarded as a Cu have. Therefore, in the present invention, the copper complex compound was analyzed using XPS to determine the Cu (I) at 932.4 eV corresponding to the binding energy of Cu 2p 3/2 and the Cu (II) photoelectron at 934.3 eV Each peak obtained by the detection is subjected to waveform separation, and the occupied area ratio of the peak of Cu (I) is specified from the peak area of each component. It is considered that the Cu (I) peak at this time is derived from " monovalent copper constituting copper oxide ". It is considered that the Cu (II) peak is derived from " bivalent copper constituting copper oxide ". It is also believed that the Cu (0) peak is derived from " zero-valent copper constituting metal copper ". In this application, Quantum 2000 (beam condition: 40 W, 200 um diameter) manufactured by Ullbach-Pigment Co., Ltd. was used as an XPS analysis apparatus, and "MultiPack ver.6.1A" And narrowing measurement was performed.

Therefore, in the case of the "fine irregularities containing the copper complex compound" of the surface treated copper foil according to the present application, the total area of each peak area of Cu (I) and Cu (II) , The occupied area ratio of the peak of Cu (I) is preferably 50% or more. When the occupied area ratio of the Cu (I) peak is less than 50%, the roughened surface of the surface-treated copper foil according to the present application is laminated on the insulating layer constituent material, It is not preferable. Herein, the occupied area ratio of the Cu (I) peak of the copper composite compound is more preferably 70% or more, further preferably 80% or more. Since copper oxide has a lower acid dissolution rate than copper oxide, the etching rate of the Cu (I) peak increases as the peak area of the Cu (I) peak increases, This is because it is possible to reduce the performance of the chemical agent. On the other hand, there is no particular limitation on the occupied area ratio of the peak of Cu (I), but it is set to 99% or less by an oxidation treatment and a reduction treatment to be described later. However, the lower the occupied area ratio of the peak of Cu (I), the more the adhesiveness with the insulating layer constituting material tends to be improved. In order to obtain good oxidation resistance, 98% or less is preferable, and 95% . The occupied area ratio of the peak of Cu (I) is calculated by a calculation formula of Cu (I) / {Cu (I) + Cu (II)} 100 (%).

The fine unevenness including the copper complex compound formed by roughening at this time satisfies the condition that the specific surface area (hereinafter simply referred to as " specific surface area ") measured by adsorbing krypton is 0.035 m ² / g or more . If the specific surface area is 0.035 m ² / g or more, the average thickness of the roughened layer becomes 200 nm in order to exceed the adhesion of the roughened copper foil to the insulating resin base. Here, although not to establish the upper limit of the specific surface area, to ensure a good etch performance equivalent to the non-roughened copper foil, the upper limit is about 0.3m ² / g, and more preferably 0.2m ² / g. The specific surface area at this time was measured by using a specific surface area and pore distribution measuring device 3Flex manufactured by Micromeritics, and heating the sample at 300 ° C for 2 hours as a pretreatment. The adsorption temperature was set at a liquid nitrogen temperature, (Kr).

Since the fine irregularities containing the copper complex compound described above are so fine as to absorb light, the surface of the roughened layer becomes darker due to blackening, brown coloring, or the like. That is, the surface of the roughened surface layer of the surface-treated copper foil according to the present application is characterized by its color tone, and the lightness L ^* of the L ^* a ^* b ^* color system is 25 or less, more preferably 20 or less. If the lightness L ^* exceeds 25 and the light color becomes bright, sufficient roughening can not be carried out, which is not preferable because "good adhesion to the insulating resin base with no wasteproof copper foil or better" can not be obtained. The lightness L ^* was measured using a spectral colorimeter SE2000 manufactured by Nippon Denshoku Kogyo Co., Ltd., and the white plate attached to the measuring apparatus was used for calibrating the lightness in accordance with JIS Z8722: 2000. And, it was made three measurements for the same parts, and the substrate 3 times the average value of the measurement data of the brightness L ^*, a brightness value L ^* of matter Application.

A description will now be given of a method of forming " fine irregularities including a copper composite compound " used for roughening a surface treated copper foil according to the present application. The copper complex compound contains copper oxide and copper oxide. This copper complex compound is formed as follows. First, the surface of the copper foil is subjected to oxidation treatment by a wet method using a solution to form " fine irregularities containing a copper compound " containing copper oxide on the surface of the copper foil. Thereafter, the copper compound is subjected to a reduction treatment to convert a part of the copper oxide into copper oxide, thereby obtaining a " fine unevenness containing a copper complex compound " containing copper oxide and copper oxide. The solution to be used for the oxidation treatment in the present application is preferably an alkaline solution which is difficult to corrode copper oxide, and an amino-based silane coupling agent which is soluble in the alkaline solution and relatively stable and can be coexisted is used . Therefore, the formation of the " fine irregularities containing copper compound " is facilitated by containing an amino-based silane coupling agent in the solution used in this oxidation treatment. Since the amino silane coupling agent is adsorbed on the surface of the copper foil, the oxidation of the surface of the copper foil is finely suppressed, so that the shape of the " fine irregularities containing the copper compound " Specific examples of the amino silane coupling agent include N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, 3- Aminopropyltrimethoxysilane, 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine, N-phenyl- Silane and the like can be used.

When the above-mentioned oxidation treatment is completed, the fine irregularities containing the copper compound are reduced. The "fine irregularities containing the copper compound" formed on the surface of the surface treated copper foil according to the present application by the oxidation treatment can be used as the fine irregularities containing the copper compound while maintaining the shape of the fine irregularities including the original copper compound, quot; fine irregularities containing a copper complex compound " containing copper oxide and copper oxide having a length in the order of nm. If the copper compound of the " micro-irregular surface containing copper compound " obtained by the oxidation treatment is left intact, erosion of the component by the etching solution or other acid solution is easy, This is because the solution erosion becomes remarkable and the performance of the chemical resistance of the formed circuit is deteriorated. Therefore, it is preferable to perform a reduction treatment to obtain a copper complex compound in which a part of the copper oxide of " fine irregularities containing copper compound " is converted to copper oxide. In this reduction treatment, by adjusting the reducing agent concentration, the solution pH, the solution temperature, and the like, the occupation area ratio of the Cu (I) peak of the "fine unevenness containing copper complex oxide" can be appropriately adjusted. Further, the copper complex compound containing copper oxide and copper oxide may contain a small amount of metallic copper.

As can be understood from the above description, the surface-treated copper foil according to the present application is immersed in the oxidation treatment solution to form "micro-irregularities containing a copper compound" containing copper oxide on the surface of the copper foil by a wet method, Thereafter, a reduction process is performed to form a " fine unevenness containing copper complex oxide " having an occupied area ratio of a peak of Cu (I) of 50% or more. Therefore, it is possible to perform simultaneous roughening simultaneously on both sides of the copper foil. Therefore, by using this wet method, it becomes possible to easily obtain a double-sided roughened copper foil suitable for forming an inner-layer circuit of a multilayer printed wiring board.

Form of copper clad laminate: The copper clad laminate according to the present application is characterized in that it is obtained by using a surface treated copper foil having the roughed surface treatment layer. The copper clad laminate at this time is not particularly limited as long as it is a copper clad laminate obtained by using the surface treated copper foil according to the present application. Further, among the concept of the copper clad laminate referred to here, the concept includes both the rigid type and the flexible type.

Example 1

Using an electrolytic copper foil (thickness 18 占 퐉) made by Mitsui Mining and Mining Co., Ltd. having a surface roughness (Rzjis) of 0.2 占 퐉 and a glossiness (Gs (60 占) of 600 as the electrolytic copper foil, The surface treatment was carried out.

Pretreatment: The electrolytic copper foil was immersed in an aqueous solution of sodium hydroxide, subjected to alkali degreasing treatment, and then washed with water. Then, the electrolytic copper foil after completion of the alkali degreasing treatment was dipped in a sulfuric acid-based solution having a hydrogen peroxide concentration of 1 mass% and a sulfuric acid concentration of 5 mass% for 5 minutes, followed by washing with water.

Oxidation treatment: The electrolytic copper foil after completion of the pretreatment was treated at a solution temperature of 70 占 폚, a pH of 12, a chloric acid concentration of 150 g / L, a concentration of N-2- (aminoethyl) -3-aminopropyltrimethoxysilane of 10 g / L was immersed in a sodium hydroxide solution for a predetermined oxidation treatment time (1 minute, 2 minutes, 4 minutes, 10 minutes) to form " fine irregularities containing a copper compound " on the surface of the electrolytic copper foil A kind of sample was obtained.

Reduction treatment: Four types of samples after completion of the oxidation treatment were immersed in an aqueous solution (room temperature) having a concentration of dimethylamine borane of 20 g / L adjusted to pH = 12 using sodium carbonate and sodium hydroxide for 1 minute, Washed with water and dried to obtain four kinds of surface-treated copper foils having a roughened surface treatment layer formed with " fine irregularities containing copper complex compound ".

1 shows a scanning electron microscopic observation of the surface of the roughed surface of the surface-treated copper foil obtained in Example 1. Fig. When the surface of the roughening treatment layer was subjected to a state analysis using XPS, the presence of "Cu (I)", "Cu (II)" and "-COO group" was confirmed. The occupied area ratio, specific surface area, lightness L * and peel strength of the Cu (I) peak of the surface-treated copper foil obtained in this example are shown in Table 1 below.

The measurement of the peel strength in the present application was carried out as follows. A surface treated copper foil serving as a sample and a prepreg (R1551) manufactured by Panasonic Corporation were used and pressed against each other under the conditions of a press pressure of 2.9 MPa, a temperature of 190 DEG C, and a pressing time of 90 minutes by using a vacuum press machine To produce a copper clad laminate. Subsequently, using this copper-clad laminate, a linear circuit for measuring a peel strength of 3 mm in width was manufactured by an etching method, and the peel strength was measured in this 3 mm circuit. In the specification, "kgf / cm" is used as the unit of the peel strength, but it can be easily converted into "N / m" from the relationship of 1 kgf / cm = 980 N / m.

Example 2

Using the same electrolytic copper foil as used in Example 1, surface treatment was carried out in the following procedure. The preliminary treatment and the oxidation treatment (oxidation treatment time: 2 minutes) are the same as those in Example 1. In Example 2, the following reduction treatment is employed in order to examine the influence of the pH and the concentration of dimethylamine borane in the aqueous solution used for the reduction treatment.

Reduction treatment: Electrolytic copper foil after completion of the oxidation treatment was adjusted to three levels of pH = 11, 12 and 13 by using sodium carbonate and sodium hydroxide and the concentration of dimethylamine borane was adjusted to 5 g / L, 10 g / L and 20 g / L (Room temperature) for one minute to perform a reduction treatment, followed by washing with water and drying to obtain a surface-treated copper foil according to the present application. The surface-treated copper foil obtained when the aqueous solution used for the reduction treatment was pH = 11 was defined as "Practical Sample 11-a, Practical Sample 11-b, and Practical Sample 11-c". The surface-treated copper foil obtained when the aqueous solution used for the reduction treatment is pH = 12 is referred to as "Practical Sample 12-a, Practical Sample 12-b, and Practical Sample 12-c". The surface treated copper foil obtained when the aqueous solution used for the reduction treatment is pH = 13 is referred to as " Practical Sample 13-a, Practical Sample 13-b, and Practical Sample 13-c ". The symbol " -a " used when referring to each sample is a case where the concentration of dimethylamine borane in the aqueous solution used for the reduction treatment is 5 g / L. The symbol " -b " indicates the case where the concentration of dimethylamine borane in the aqueous solution used for the reduction treatment is 10 g / L. Quot; -c " indicates that the concentration of dimethylamine borane in the aqueous solution used for the reduction treatment is 20 g / L.

The scanning electron microscopic observation of the surface treated copper foil of all the samples obtained in Example 2 was the same as that shown in Fig. When the state of "micro-irregularities including the copper complex compound" on the surface of the roughened layer of each of the samples is analyzed using XPS, "Cu (I)", "Cu -COO group " was confirmed. The occupied area ratio, specific surface area, lightness L ^* and peel strength of the Cu (I) peak of the surface-treated copper foil obtained in this example are shown together in Table 2 below.

Comparative Example

In the comparative example, the same electrolytic copper foil as the example was used, and the same pretreatment as in the example was carried out, followed by blackening treatment and reduction treatment to obtain a comparative sample. Hereinafter, the blackening treatment and the reduction treatment will be described.

Blackening treatment: The electrolytic copper foil after completion of the preliminary treatment was treated with 10 vol% of "PRO BOND 80A OXIDE SOLUTION" which is an oxidation treatment liquid manufactured by Rohm and Haas Electric Material Company, and "PRO BOND 80B OXIDE SOLUTION" And 20 vol% of water at 85 DEG C for 5 minutes to form a general blackening treatment on the surface.

Reduction treatment: Electrolytic copper foil after completion of the oxidation treatment was treated with 6.7 vol% of "CIRCUPOSIT PB OXIDE CONVERTER 60C" which was a reduction treatment solution manufactured by Rohm and Haas Electric Material Industry Co., Ltd., 1.5 vol% of "CUPOSIT Z" , Washed with water and dried to obtain a comparative sample having a reduced blackened surface as shown in Fig. 4 (b).

When the surface of the roughened surface layer of the surface treated copper foil (comparative sample) obtained in this Comparative Example was subjected to state analysis using XPS, the presence of "Cu (0)" was clearly confirmed, The presence of "Cu (I)" was also confirmed, but the "-COO group" could not be confirmed. The occupied area ratio, specific surface area, lightness L ^* and peel strength of the Cu (I) peak of the surface-treated copper foil obtained in this Comparative Example are as shown in Table 2.

[Contrast of Examples and Comparative Examples]

Contrast of Example 1 and Comparative Example: With reference to the following Table 1, the contrast between Example 1 and Comparative Example is made.

As can be understood from this Table 1, even if the oxidation treatment time varies between 1 minute and 10 minutes, the maximum length of the " fine irregularities containing the copper complex compound " seen from the surface of the roughed surface layer is 100 nm, There is no change in the content detected in the state analysis of roughened surface. On the other hand, in the case of the comparative example, the maximum length of the concavities and convexities is 500 nm, which is about 5 times larger. That is, it can be seen that the "micro-irregularities containing the copper complex compound" of the surface treated copper foil according to the present application is much finer than the conventional blackening treatment.

Then, the specific surface area of the comparative example is larger than that of the first embodiment. However, when these surface-treated copper foils were measured against the insulating resin base material and the peel strength was measured, the peel strengths of the examples were 0.63 kgf / cm to 0.78 kgf / cm. Even at the shortest oxidation treatment time, a practically sufficient peel strength is obtained, and a peel strength proportional to the value of the specific surface area is obtained. On the other hand, the peel strength of Comparative Example having a specific surface area higher than that of Example 1 was lowered to 0.33 kgf / cm. Generally, the higher the value of the specific surface area is, the higher the peel strength is, but the opposite is made. This is considered to be because the unevenness of the blackening treatment in the comparative example is degraded in strength. This will be described in detail in " Contrast of Example 2 and Comparative Example " which will be described later. In addition, in Example 1 alone, the specific surface area increases in proportion to the increase of the oxidation treatment time. That is, the oxidation treatment time employed in the first embodiment can be judged to be appropriate. In addition, the value of brightness L ^* of the roughened surface of Example 1 also shows a very small deviation of 18 to 20.

Fig. 2 shows a scanning electron microscope observation image for observing the roughening pattern on the electrode surface side and the precipitation surface side of the surface-treated copper foil obtained under the conditions of the immersion time of 2 minutes for the oxidation treatment in Example 1. Fig. From Fig. 2, macroscopically, the electrode surface side and the precipitation surface side surface shape of the electrolytic copper foil before roughening are retained even after roughening, and the " fine unevenness including the copper complex compound " As shown in FIG. Therefore, in the case of the surface-treated copper foil according to the present application, roughening is carried out in a shape corresponding to the surface shape while maintaining the macroscopic surface shape of the copper foil before roughening with " fine unevenness containing copper complex compound & It is clear that it is losing.

Contrast of Example 2 and Comparative Example: The comparison between Example 2 and Comparative Example is made with reference to Table 2 below.

In Table 2, the surface treated copper foils obtained when the aqueous solution to be used for the reduction treatment was pH = 11, taking note of the occupied area ratio of the peak of Cu (I) (Practical Sample 11-a, Practical Sample 11-b, treated sample copper foil (sample 12-a, sample 12-b, sample 12-c) obtained when the aqueous solution used for the reduction treatment was pH = 12 and the aqueous solution used for the reduction treatment The occupied area ratio of the peak of Cu (I) was found to be in the range of 59% to 99% when the surface treated copper foil obtained in the pH = 13 (Examples 13-a, 13-b and 13- . On the contrary, the occupied area ratio of the peak of Cu (I) was 83% in the comparative sample. Therefore, it can be seen that there is no difference between the occupied area ratios of the Cu (I) peaks in the examples and the comparative examples. In the state analysis by the above-described XPS, the detected components are different.

Therefore, the roughened state of the test sample and the comparative sample is observed by electron microscope observation. Referring to Fig. 2, it is understood that the roughened state of the test sample can be understood. 3, the state of the cross-section of the roughened layer relating to the test sample can be understood. On the other hand, on the electron microscopic observation of the roughened state shown in Fig. 4 (a) immediately after the blackening treatment in the comparative example, a long, thick needle shape appears and the tip of the blackening treatment is sharp. The thickness of the roughed surface layer formed by the needles was 500 nm to 700 nm. However, as shown in Fig. 4 (b), when the reduction treatment is performed and the reduction blackening treatment is carried out, the tip portion of the unevenness is rounded, and it can be understood that the roughening shape is largely changed by the reduction treatment.

5 (a) shows a cross-section of the surface roughened layer immediately after the blackening treatment in the comparative example. FIG. 5 (b) shows a cross section after the reduction treatment and the reduction blackening treatment. It can be seen from Fig. 5 that the irregularities before the reduction by the reduction treatment suffered considerably large damage. That is, it can be seen that the needle shape formed by the oxidation treatment is thin and finely insulated by the reduction treatment. On the contrary, the roughened shape of the "fine irregularities including the copper composite compound" of the embodiment is not damaged at all, even if the reducing treatment is carried out, as can be understood from the cross section in FIG. Therefore, the unevenness of the comparative sample after the reduction treatment of the comparative sample is very brittle as compared with that of the practical sample, so that it is predicted that a problem of so-called powder falling occurs.

Therefore, the peeling strength of the surface-treated copper foil obtained in Example 2 and Comparative Example is prepared. As a result, the peel strength of the test sample was 0.70 kgf / cm to 0.81 kgf / cm. On the other hand, the peel strength of the comparative sample was 0.33 kgf / cm, which is lower than that of the test sample.

[Industrial applicability]

The surface-treated copper foil according to the present invention described above is roughened with " fine irregularities containing a copper complex compound having a maximum length of not more than 500 nm ", and compared with the adhesion to the insulating resin base of the roughened copper foil, Good adhesion with the resin base material can be ensured. In addition, since the micro-irregularities including the copper composite compound having the maximum length of not more than 500 nm of the surface treated copper foil according to the present application are very fine, it is sufficient to provide a very short overetching time at the time of etching And a fine pitch circuit with a good etch factor can be expected. Therefore, it can be usefully used in all printed wiring board products. As described above, the surface-treated copper foil according to the present application may be formed by roughening both surfaces of copper foil, and may be a double-sided roughened copper foil suitable for forming an inner layer circuit of a multilayer printed wiring board. have.

Claims (7)

A surface treated copper foil obtained by roughening the surface of a copper foil,
The surface of the copper foil is subjected to surface roughening treatment in which needle-shaped or plate-like fine irregularities having a maximum length of 350 nm or less including a copper complex compound containing copper oxide and copper oxide extending from the surface of the copper foil in cross- And,
The needle-like or plate-like fine irregularities including the copper complex compound containing copper oxide and copper oxide were determined to have a total area of each peak area of Cu (I) and Cu (II) when analyzed by XPS to 100% Wherein the occupied area ratio of the Cu (I) peak is 50% or more and 99% or less. The method according to claim 1,
Wherein presence of a -COO group is confirmed when XPS analysis of needle-shaped or plate-like fine irregularities containing the copper complex compound containing copper oxide and copper oxide is confirmed. 3. The method of claim 2,
Wherein the copper complex compound containing copper oxide and copper oxide contains copper carbonate. 4. The method according to any one of claims 1 to 3,
The needle-like or plate-like micro-irregularities containing the copper complex compound were observed with a scanning electron microscope at a maximum angle of 150 nm when observed from the surface of the roughed surface layer at a tilt angle of 45 DEG and a magnification of 50,000 times or more Or less. 4. The method according to any one of claims 1 to 3,
The needle-like or plate-like fine unevenness containing the copper complex compound has a specific surface area of 0.035 m ² / g or more as measured by adsorbing krypton. 4. The method according to any one of claims 1 to 3,
Wherein the surface of the roughed surface treatment layer has a lightness of L ^* a ^* b ^* lightness L ^* of 25 or less. A copper clad laminate obtained by using the surface treated copper foil according to any one of claims 1 to 3.

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