TWI543862B - Surface-treated copper foil and copper clad laminate using the same - Google Patents

Description

Surface treated copper foil and copper clad laminate obtained by using surface treated copper foil

The present application relates to a surface-treated copper foil and a copper-clad laminate obtained by using a surface-treated copper foil. In particular, the surface-treated copper foil in which the surface of the copper foil is roughened by fine irregularities in the form of needles or plates made of a copper composite compound.

In general, many copper foils that are in circulation in the market are used in the formation of circuits for printed wiring boards, and in order to improve the adhesion to the insulating resin substrate, the anchoring effect is provided on the surface of the copper foil to be the surface. Thicken the shape. For example, the "attachment of fine copper particles" as disclosed in the patent document 1 (Japanese Patent Application Laid-Open No. Hei 05-029740), and the like. In the case of the "concave-convex formation by etching" disclosed in Japanese Laid-Open Patent Publication No. 2000-282265.

However, in recent years, the demand for the formation of the micro-pitch circuit is remarkable, and the manufacturing technology of the printed wiring board is also greatly improved, as in Patent Document 3 (Japanese Patent Application Laid-Open No. Hei 09-074273) and Patent Document 4 The use of the non-roughened copper foil disclosed in Japanese Laid-Open Patent Publication No. 2008-297569.

In order to provide a copper-clad laminate for a printed circuit in which a copper foil and a laminated substrate are firmly adhered to each other by using a strong and reactive adhesive, the following disclosure is disclosed: "A copper-clad laminate for a printed circuit. a board that is attached to a single side of a laminated substrate or A copper-clad laminate with copper foil laminated on both sides, characterized in that a. on the copper foil, the medium is separated by the formula QRSiXYZ...[1] (however, Q represents a composition with the following resin a functional group for the reaction, R represents a decane coupling agent which bonds a bond of Q and a Si atom, X, Y, Z represents a hydrolyzable group or a hydroxy group bonded to a Si atom, or has a general formula T (SH) n) [2] (but T is an aromatic ring, an aliphatic ring, a heterocyclic ring, an aliphatic chain, and n is an integer of 2 or more), and the thiol-based decane coupling agent is formed as an adhesion substrate. By b. an adhesive formed from the following (1) to (6) and a laminated material: (1) an acrylic monomer, a methacrylic monomer, a polymer of the same or a copolymer with an olefin, 2) a diallyl phthalate, an epoxy acrylate or an epoxy methacrylate, and a peroxide curable resin composition of the oligomer, (3) an ethylene butene in the molecule a peroxide cured resin composition of a thermoplastic elastomer of a copolymer and a styrene copolymer, (4) a resin composition of a glycidyl group-containing olefin copolymer, and (5) having an unsaturated group a resin composition of a polyvinyl butyral resin of a side chain, or a resin composition of (6) a polyvinyl butyral resin and an amine-based resin having an acetal ring and an epoxy resin, or a resin The laminated substrate of the adhesive of the composition is directly followed.

Moreover, Patent Document 4 provides a surface treatment layer which does not contain Chromium, a surface-treated copper foil excellent in tearing strength of a circuit after processing into a printed wiring board, and a chemical resistance deterioration rate such as the peeling strength, and reveals that "a surface-treated copper foil is characterized and insulated. a surface-treated copper foil provided with a surface-treated layer on a copper foil bonding surface used for bonding a resin substrate to a copper-clad laminate, wherein the surface-treated layer is adhered to a copper foil bonding surface, Further, a high-melting-point metal component having a melting point of 1400 ° C or higher is attached, and a carbon component is adhered thereto, and "the use of the copper foil is preferably used." The surface is not subjected to roughening treatment and the surface roughness (Rzjis) is 2.0 μm or less.

The above non-roughened copper foil is not on the surface of the insulating resin substrate There are irregularities used for roughening. Therefore, it is not necessary to provide an excessive etching time for removing the anchor shape (concavo-convex shape) in a state of being buried on the side of the insulating resin substrate when the copper foil is etched and formed. Therefore, it is very useful in forming a micro-pitch circuit having a good etching factor.

However, the non-roughened copper foil is buried in the side of the insulating resin substrate Since the anchored shape (concave-convex shape) of the state is high, the adhesion of the roughened copper foil to the insulating resin substrate tends to be lower than that of the roughened copper foil.

Therefore, there are on the market compared to the non-roughened copper foil for the insulating resin base. The adhesiveness of the material is required to have better adhesion to the insulating resin substrate, and it is required to have a copper foil having good etching performance equivalent to that of the roughened copper foil having no irregularities for roughening.

Therefore, as a result of the active research by the inventors of the present invention, it has been found that the copper foil described below can be provided with an insulating resin in an anchor shape (concavo-convex shape) in a state in which the insulating resin substrate is embedded. Good adhesion of the substrate. Hereinafter, the surface-treated copper foil of the present application will be described.

Surface-treated copper foil: The surface-treated copper foil of the present application is characterized in that the surface of the copper foil is roughened by surface-treated copper foil, and the surface of the copper foil is provided with a copper composite compound having a maximum length of 500 nm or less. A roughened layer formed by fine irregularities in the form of needles or plates. In the following, the "fine or irregular shape of the needle-like or plate-like shape formed by the copper composite compound" is simply referred to as "fine irregularities formed by the copper composite compound".

The copper composite compound of the roughened layer of the surface treated copper foil of the present application The maximum irregularity of the material was 150 nm or less when observed from the surface of the roughened layer by a scanning electron microscope at a magnification of 45° or more and a magnification of 50,000 times or more.

The surface-treated copper foil of the present application is made of a copper composite compound In the unevenness, when the total area of the respective wave front areas of Cu(I) and Cu(II) in the XPS analysis is 100%, the occupied area ratio of the Cu(I) peak is preferably 50% or more.

The surface-treated copper foil of the present application is made of a copper composite compound The bumps contain copper oxide and cuprous oxide.

In addition, the surface treated copper foil of the present application is formed of a copper composite compound. The fine unevenness and the specific surface area measured by krypton are preferably 0.035 m 2 /g or more.

Furthermore, the surface of the roughened layer of the surface-treated copper foil of the present application The surface preferably has a brightness L* of L*a*b* color system of 25 or less.

Copper-clad laminate: The characteristics of the copper-clad laminate of the present application are as follows The surface is treated with copper foil.

The surface treated copper foil of the present application is "having a maximum length of 500 nm" The fine unevenness formed by the underlying copper composite compound forms a roughened surface. Further, although the roughened surface is located on the outermost surface of the copper foil, the μm-scale micro-concave shape of the copper foil and the insulating resin substrate are directly maintained. As a result, it is possible to ensure better adhesion than the adhesion of the non-roughened copper foil to the insulating resin substrate.

Fig. 1 is a scanning electron microscope observation image (a sample in which the immersion time of the oxidation treatment in Example 1 was immersed for 2 minutes) for explaining the roughened form of the surface-treated copper foil of the present application.

2 is a scanning electron microscope observation image in which the roughened form is different depending on the roughened target portion of the electrode surface and the deposition surface of the electrolytic copper foil in the surface-treated copper foil of the present application (Example 1) The immersion time of the oxidation treatment was 2 minutes.

Fig. 3 is a scanning electron microscope observation image of the cross section of the roughened layer of the surface-treated copper foil of the present application (the sample of the immersion time of the oxidation treatment in Example 1 for 2 minutes).

Fig. 4 is a scanning electron microscope observation image of the roughened treatment form of the comparative sample in the comparative example from the surface.

Fig. 5 is a scanning electron microscope observation image of the roughened layer of the comparative sample in the comparative example.

Hereinafter, the "form of the surface-treated copper foil" and the "form of the copper-clad laminate" in the present application will be described.

The surface-treated copper foil is characterized in that the surface-treated copper foil of the present application is characterized in that the surface of the copper foil is roughened in a surface-treated copper foil, and a copper composite compound having a maximum length of 500 nm or less is provided on the surface of the copper foil. A roughened layer formed by fine concavities and convexities.

The copper foil used in the manufacture of the surface treated copper foil of the present application can be used. Any one of copper foil and rolled copper foil. Further, the thickness of the copper foil is not particularly limited, and it is generally sufficient to recognize a thickness of 200 μm or less. Further, the surface-treated copper foil of the present application is intended to be both roughened on one side and roughened on both sides.

The roughened surface of the surface treated copper foil of the present application is preferably copper foil The surface is formed with "fine irregularities made of a copper compound" containing copper oxide, and a part of the copper oxide is converted into cuprous oxide by reduction treatment, whereby the maximum length is 500 nm by containing copper oxide and cuprous oxide. The fine concavities and convexities formed by the following copper composite compound are coarsened. Here, the "maximum length is 500 nm or less" is the maximum value of the "fine irregularities formed by the copper composite compound" when the surface of the surface-treated copper foil is observed by the electric field radiation type scanning electron microscope. The maximum value of the shape of the "fine concavities and convexities formed by the copper composite compound" is as shown in FIG. 3, which will be described later, and the roughened layer formed by the fine concavities and convexities formed by the copper composite compound on the surface of the copper foil. In the cross section, the length of the needle or plate extending from the surface of the copper foil. From the viewpoint of improving the adhesion between the surface-treated copper foil of the present application and the insulating layer constituent material, the maximum length is preferably 400 nm or less, more preferably 300 nm or less. Further, the maximum length is sometimes referred to as "maximum length 1".

Moreover, the roughened layer constituting the surface-treated copper foil of the present application is "The fine concavities and convexities formed by the copper composite compound" are shown in Fig. 1. Using a scanning electron microscope of an electric field radiation type, the plane is at a magnification of 50,000 times or more (the sample tilt angle is 45° when observed by a scanning electron microscope). When the surface of the roughened layer is observed, the "maximum length of the fine concavities and convexities formed by the copper composite compound" is preferably 150 nm or less. Figure 1 shows When the deposition surface (Fig. 1 (a)) of the double-sided smooth electrolytic copper foil is roughened by the "fine irregularities formed of the copper composite compound" of the present application, it is observed as shown in Fig. 1(b). Further, Fig. 1(c) shows an observation image in which the surface of Fig. 1(b) is further enlarged to 50,000 times. From the viewpoint of improving the adhesion between the surface-treated copper foil of the present application and the insulating layer constituent material, the maximum length is more preferably 100 nm or less. Further, the maximum length is sometimes referred to as "maximum length 2".

When listed, the non-contact three-dimensional element manufactured by Zygo Co., Ltd. Surface shape. Roughness measuring machine (Model: New-View 6000) When the precipitation surface of the electrolytic copper foil before roughening shown in Fig. 1 (a) was measured, Ra = 1.6 nm and Rz = 26 nm. The surface of the electrolytic copper foil is roughened by the "fine irregularities formed of the copper composite compound" in the present application, and the electrolytic copper foil after the roughening treatment shown in Fig. 1 (b) is used. When the surface was measured in the same manner, Ra = 2.3 nm and Rz = 39 nm, which is understood to be roughenable by the nm level. Further, in Fig. 2, the roughened form differs depending on the roughened portion of the electrode surface of the electrolytic copper foil and the deposited surface. This Figure 2 is detailed in the examples.

In addition, FIG. 3 shows the composite of copper formed by the coarsening at this time. A section of fine irregularities formed by the object. In this cross section, although the thickness of the roughened layer formed by the fine concavities and convexities of the copper composite compound is constant, the average thickness from the surface of the copper foil is still 400 nm or less. The average thickness of the roughened layer shown in Fig. 3 is 250 nm. As a result of performing most of the tests, the inventors of the present application judged that if the average thickness of the roughened layer is limited to the range of 100 nm to 350 nm, it can be provided to be "higher than the non-roughened copper foil for the insulating resin substrate. Good adhesion."

Next, the composition of the fine concavities and convexities formed by the copper composite compound Try to use X-ray photoelectron spectroscopy (X-ray Photoelectron) Spectroscopy: hereinafter referred to as "XPS" for status analysis. As a result, it was confirmed that "Cu(0)", "Cu(II)", "Cu(I)", and "-COO group" exist. Here, since it is confirmed that "-COO group" exists, it is considered that the possibility of containing "copper carbonate" is high.

Moreover, before using the above XPS to analyze the surface treated copper foil of the present application When the copper composite compound is described, each peak of Cu(I) and Cu(II) can be separated and detected. When the copper composite compound was analyzed by the XPS, since the Cu(0) peak was repeatedly observed in the shoulder portion of the large Cu(I) peak, it was regarded as the Cu(I) peak including the shoulder portion. . Therefore, in the present application, XPS is used to analyze the copper composite compound, and the photoelectron corresponding to Cu 2p 3/2 bonding energy appearing at 932.4 eV Cu(I) and 934.3 eV Cu(II) The detected peaks are separated by a waveform, and the area of the peak of the Cu(I) peak is specified by the peak area of each component. The Cu(I) peak at this time is considered to be derived from "monovalent copper constituting cuprous oxide". Further, the Cu(II) peak is considered to be derived from "two-valent copper constituting copper oxide". Furthermore, the Cu(0) peak is considered to be derived from "zero-valent copper constituting metallic copper." In the present application, Quantum 2000 (beam condition: 40 W, 200 μm diameter) manufactured by ULVAC-PHI Co., Ltd. is used as an XPS analysis device, and "MultiPack ver.6.1A" is used as an analytical software for the state. Semi-quantitative stenosis.

Accordingly, the surface treated copper foil of the present application is "made of a copper composite compound" In the case of the fine concavities and convexities, when the total area of the respective peak areas of Cu(I) and Cu(II) in the XPS analysis is 100%, the occupied area ratio of the Cu(I) peak is preferably 50%. the above. When the occupied area ratio of the Cu(I) peak is less than 50%, the roughened surface area of the surface-treated copper foil of the present application is layered on the insulating layer constituent material, and the chemical resistance of the circuit formed by the circuit is lowered. Not good. Here, the Cu(I) peak of the aforementioned copper composite compound accounts for The area ratio is better than 70%, and more preferably 80% or more. The reason is that the cuprous oxide phase is lower in acid solubility than the copper oxide, so when the occupied area ratio of the Cu(I) peak is increased, there is an etching liquid in the etching step when the circuit is formed. The plating solution or the like can improve the chemical resistance of the insulating portion to the intimate portion of the insulating material. On the other hand, the area ratio of the Cu(I) peak is not particularly limited, but is 99% or less by the oxidation treatment and the reduction treatment described later. However, the lower the occupied area ratio of the Cu(I) peak, the tendency to improve the adhesion to the insulating layer constituent material, and in order to obtain good oxidation resistance, it is preferably 98% or less, more preferably 95% or less. Further, the area ratio of the Cu(I) peak is calculated by the calculation formula of Cu(I) / {Cu(I) + Cu(II)} × 100 (%).

Moreover, the copper composite compound formed by the coarsening at this time The fine concavities and convexities preferably satisfy the condition that the specific surface area (hereinafter simply referred to as "specific surface area") measured by the adsorption enthalpy is 0.035 m 2 /g or more. When the specific surface area is 0.035 m 2 /g or more, the average thickness of the roughened layer is 200 nm, which is superior to the adhesion of the non-roughened copper foil to the insulating resin substrate. Here, the upper limit of the specific surface area is not fixed, but the upper limit is about 0.3 m 2 /g, more preferably 0.2 m 2 /g, in order to ensure good etching performance equivalent to that of the non-roughened copper foil. Moreover, the specific surface area at this time is the specific surface area manufactured by Micromeritics. The pore distribution measuring device 3Flex was subjected to heating at 300 ° C for 2 hours as a pretreatment, and the liquid nitrogen temperature was used at the adsorption temperature, and the adsorption gas was measured using hydrazine.

The "fine concavities and convexities formed by the copper composite compound" described above are finer in light absorption, so that the surface of the roughened layer is darkened to blackening or browning. That is, the surface of the roughened layer of the surface-treated copper foil of the present application also has a color tone. Features, and the brightness L* of the L*a*b* color system is 25 or less, more preferably 20 or less. When the brightness L* exceeds 25 and becomes a bright color tone, it is not sufficiently roughened, and it is not preferable because "the adhesiveness of the roughened copper foil is more excellent than the insulating resin substrate". Further, the measurement of the luminance L* was carried out by using a spectrophotometer SE2000 manufactured by Nippon Denshoku Industries Co., Ltd., and the calibration of the luminance was carried out in accordance with JIS Z8722:2000 using a white plate attached to the measuring device. Further, the measurement was performed three times for the same portion, and the average value of the measurement data of the brightness L* measured three times is described as the value of the brightness L* of the present application.

Next, a method of forming the "fine irregularities formed of the copper composite compound" used for the roughening of the surface-treated copper foil of the present application will be described. Further, the copper composite compound contains copper oxide and cuprous oxide. This copper composite compound is formed as follows. First, the surface of the copper foil is oxidized by a wet method using a solution, and "fine irregularities made of a copper compound" containing copper oxide are formed on the surface of the copper foil. Subsequently, the copper compound is subjected to a reduction treatment to convert a part of the copper oxide into cuprous oxide, and the "fine irregularities formed by the copper composite compound" containing copper oxide and cuprous oxide. The solution used for the oxidation treatment in the present application is preferably an alkaline solution which does not easily erode copper oxide, and an amine-based decane coupling agent which is soluble in an alkaline solution and which can coexist more stably. Here, since the solution used for the oxidation treatment contains an amine-based decane coupling agent, formation of "fine irregularities formed of a copper compound" is facilitated. By adsorbing the amine-based decane coupling agent on the surface of the copper foil, the oxidation of the surface of the copper foil is finely suppressed, so that it is in the shape of "fine irregularities made of a copper compound". When the amine decane coupling agent is specifically exemplified, N-2-(aminoethyl)-3-aminopropylmethyldimethoxydecane, N-2-(aminoethyl)-3 can be used. -Aminopropyltrimethoxydecane, 3-aminopropyltrimethoxydecane, 3-aminopropyltriethoxydecane, 3-triethoxydecyl-N-(1,3-dimethyl-butylene)propylamine, N-phenyl-3-aminopropyltrimethoxydecane, and the like.

Then, at the end of the oxidation treatment, the copper compound is formed. The fine unevenness is subjected to reduction treatment. In the surface of the surface-treated copper foil of the present application, the "fine concavities and convexities formed by the copper compound" formed by the oxidation treatment substantially maintain the shape of the fine concavities and convexities formed by the copper compound at the time of the reduction treatment. It is a "fine unevenness formed of a copper composite compound" containing copper oxide and cuprous oxide having a length of nm. The reason is that when the copper compound which is "fine irregularities made of a copper compound" obtained by the oxidation treatment is left as it is, the surface-treated copper foil and the insulating resin substrate are easily eroded by the etching liquid of the component and other acid solutions. The solution at the interface is significantly eroded, thereby deteriorating the chemical resistance of the formed circuit. Therefore, it is preferred to carry out a reduction treatment to convert a part of the copper oxide "fine irregularities formed by the copper compound" into cuprous oxide to form a copper composite compound. In the reduction treatment, by adjusting the concentration of the reducing agent, the pH of the solution, the temperature of the solution, and the like, the area ratio of the Cu(I) peak of the "fine irregularities formed by the copper composite oxide" can be appropriately adjusted. Further, the copper composite compound containing copper oxide and cuprous oxide may also contain a small amount of metallic copper.

Based on the above, it can be understood that the surface treated copper foil of the present application is immersed in In the oxidation treatment solution, a "fine irregularity formed of a copper compound" containing copper oxide is provided on the surface of the copper foil by a wet method, and then the area ratio of the Cu(I) peak formed by the reduction treatment is 50% or more. "Micro-concave irregularities made of copper composite oxide." According to this, both sides of the copper foil can be simultaneously roughened. Therefore, when the wet method is used, the double-faced roughened copper foil suitable for the formation of the inner layer circuit of the multilayer printed wiring board can be easily obtained.

The form of the copper-clad laminate: the characteristics of the copper-clad laminate in this application are It is obtained by the surface-treated copper foil which has the said roughening process layer. In the case where the copper-clad laminate in this case is obtained by using the surface-treated copper foil of the present application, the constituent components, the thickness, the bonding method, and the like of the insulating resin substrate to be used are not particularly limited. In addition, the concept of the copper-clad laminate as referred to herein includes the concept of both hard and flexible.

[Example 1]

The surface roughness (Rzjis) of the precipitated surface was 0.2 μm, and the gloss was used. [Gs (60°)] was an electrolytic copper foil (thickness: 18 μm) manufactured by Mitsui Metals Co., Ltd., 600, and was subjected to surface treatment in the following order.

Pretreatment: the electrolytic copper foil is immersed in an aqueous sodium hydroxide solution Alkali degreasing treatment, washing with water. Subsequently, the electrolytic copper foil which had been subjected to the alkali degreasing treatment was immersed in a sulfuric acid-based solution having a hydrogen peroxide concentration of 1% by mass and a sulfuric acid concentration of 5% by mass for 5 minutes, and then washed with water.

Oxidation treatment: immersing the above-mentioned pretreated electrolytic copper foil in liquid temperature 70 ° C, pH = 12, containing chlorous acid concentration of 150g / L, N-2-(aminoethyl)-3-aminopropyltrimethoxydecane concentration of 10g / L sodium hydroxide solution, Four kinds of samples having "fine irregularities made of a copper compound" formed on the surface of the electrodeposited copper foil were obtained by immersing the specific oxidation treatment time (1 minute, 2 minutes, 4 minutes, and 10 minutes).

Reduction treatment: immersing four kinds of samples which have been subjected to oxidation treatment in the use of carbonic acid Sodium and sodium hydroxide were adjusted to a pH=12 dimethylamine borane concentration of 20 g/L in an aqueous solution (room temperature) for 1 minute, subjected to reduction treatment, washed with water, and dried to obtain "with copper composite compound". Four kinds of surface-treated copper foils of the roughened layer of the fine concavities and convexities.

The surface of the roughened layer of the surface-treated copper foil obtained in Example 1 The scanning electron microscope observation image system is as shown in FIG. Further, when the surface of the roughened layer was subjected to state analysis using XPS, it was confirmed that "Cu(I)", "Cu(II)", and "-COO group" were present. Further, the area ratio, specific surface area, brightness L*, and tear strength of the Cu(I) peak of the surface-treated copper foil obtained in this example are shown in Table 1 below.

Further, the measurement of the tear strength in the present application was carried out as follows. A surface-treated copper foil as a sample and a prepreg (R1551) manufactured by Panasonic Co., Ltd. were used, and a vacuum pump was used to bond the pressure to a pressure of 2.9 MPa, a temperature of 190 ° C, and a press time of 90 minutes. Paste copper laminate. Next, using this copper-clad laminate, a linear circuit for measuring the tear strength of 3 mm width was produced by an etching method, and the tear strength of the 3 mm circuit was measured. Further, in the specification, the unit of the tear strength is "kgf/cm", but the relationship of 1 kgf/cm = 980 N/m can be easily converted into "N/m" unit.

[Embodiment 2]

The same electrolytic copper foil as used in Example 1 was used, in the following order Perform surface treatment. The pretreatment and oxidation treatment (oxidation treatment time: 2 minutes) were the same as in Example 1. Further, in Example 2, in order to observe the influence of the pH of the aqueous solution used for the reduction treatment and the concentration of dimethylamine borane, the following reduction treatment was employed.

Reduction treatment: immersing the electrolytic copper foil which has been subjected to oxidation treatment in the carbon to be used 9 kinds of each aqueous solution (room temperature) which is combined with sodium hydroxide and sodium hydroxide to be three levels of pH=11, 12, and 13 and dimethylamine borane concentration of 5g/L, 10g/L, and 20g/L. 1 minute, subjected to reduction treatment, washed with water, dried to obtain surface treated copper of the present application Foil. The surface-treated copper foil obtained by the aqueous solution used for the reduction treatment at pH=11 is referred to as "the sample 11-a, the sample 11-b, and the sample 11-c". The surface-treated copper foil obtained when the pH of the aqueous solution used for the reduction treatment was 12 was referred to as "the sample 12-a, the sample 12-b, and the sample 12-c". In addition, the surface-treated copper foil obtained by the pH of the aqueous solution used for the reduction treatment is referred to as "the sample 13-a, the sample 13-b, and the sample 13-c". Further, "-a" at the time of carrying out each sample is shown to be a case where the concentration of dimethylamine borane in the aqueous solution used for the reduction treatment is 5 g/L. Further, "-b" indicates a case where the concentration of dimethylamine borane in the aqueous solution used for the reduction treatment is 10 g/L. "-c" indicates a case where the concentration of dimethylamine borane in the aqueous solution used for the reduction treatment is 20 g/L.

The surface-treated copper foil sweep of all the samples obtained in this Example 2 The image was observed in the same state as that shown in Fig. 1 by a scanning electron microscope. In addition, "the fine concavities and convexities formed by the copper composite compound" on the surface of the roughened layer of each of the samples were confirmed to have "Cu(I)" and "Cu(II) when analyzed by XPS. And "-COO base". The area ratio, specific surface area, brightness L*, and tear strength of the Cu(I) peaks of the surface-treated copper foil obtained in this example are shown in Table 2 below.

[Comparative example]

The comparative example uses the same electrolytic copper foil as the embodiment, and the embodiment and the embodiment are used. The same pretreatment, blackening treatment, and then reduction treatment to obtain comparative samples. Hereinafter, the blackening process and the reduction process will be described.

Blackening treatment: immersing the above-mentioned pretreated electrolytic copper foil in Rohmha The oxidation treatment liquid manufactured by Sis Electronic Materials Co., Ltd. contains 10 vol% of "PRO" BOND 80A OXIDE SOLUTION, 20 vol% of "PRO BOND 80B OXIDE SOLUTION" in an aqueous solution at 85 ° C for 5 minutes, forming a general blackening treatment on the surface.

Reduction treatment: immersing the electrolytic copper foil which has been oxidized in Rohm and Haas The reduction treatment liquid manufactured by Electronic Materials Co., Ltd. contains 6.7 vol% of "CIRCUPOSIT PB OXIDE CONVERTER 60C" and 1.5 vol% of "CUPOSIT Z" in an aqueous solution at 35 ° C for 5 minutes, and is washed with water and dried to obtain A comparative sample having a reduced blackened surface shown in Fig. 4(b).

Surface-treated copper foil obtained by this comparative example using XPS (comparative sample) In the state analysis of the surface of the roughened layer, it was confirmed that "Cu(0)" was present, and "Cu(II)" and "Cu(I)" were confirmed, but "-COO" was not confirmed. base". The area ratio, specific surface area, brightness L*, and tear strength of the Cu(I) peak of the surface-treated copper foil obtained in this comparative example are shown in Table 2 below.

[Comparison of Examples and Comparative Examples]

Comparison of Example 1 and Comparative Example: A comparison of Example 1 with a comparative example was carried out with reference to Table 1 below.

It can be understood from Table 1 that the oxidation treatment is changed even between 1 minute and 10 minutes. The maximum length of the "fine concavities and convexities formed by the copper composite compound" as seen from the surface of the roughened layer was 100 nm, and the detection contents of the state analysis of the roughened surface did not change. On the other hand, in the case of the comparative example, the maximum length of the concavities and convexities was 500 nm, which was about 5 times larger than that of the examples. That is, it can be seen that the "fine irregularities formed of the copper composite compound" of the surface-treated copper foil of the present application is extremely finer than the conventional blackening treatment.

Next, when the specific surface area was observed, compared with Example 1, the comparative example showed Show a larger value. However, when the surface-treated copper foil was bonded to an insulating resin substrate, and the peel strength was measured, the tear strength of the example was 0.63 kgf/cm to 0.78 kgf/cm. Even with the shortest oxidation treatment time, a practically sufficient tear strength can be obtained to obtain a tear strength which is proportional to the value of the specific surface area. On the other hand, in the comparative example having the specific surface area higher than that of Example 1, the tear strength was lowered to 0.33 kgf/cm. Generally, the higher the value of the specific surface area, the higher the tear strength, but the opposite is true here. This is considered to be caused by deterioration of the unevenness of the blackening treatment in the comparative example. This will be described in detail in "Comparison of Example 2 and Comparative Example" which will be described later. Further, when only Example 1 was observed, the specific surface area also became proportionally larger as the oxidation treatment time was increased. That is, the oxidation treatment time employed in the embodiment 1 can be judged to be appropriate. Further, the value of the brightness L* of the roughened surface treatment of Example 1 also showed a value which was extremely small and was 18 to 20.

Further, Fig. 2 is for showing the impregnation observed by the oxidation treatment of Example 1. A scanning electron microscope observation image of the roughened form of the electrode surface side and the deposition surface side of the surface-treated copper foil obtained under the conditions of 2 minutes. 2, the surface shape of the electrode surface side and the deposition surface side of the electrodeposited copper foil before roughening is maintained after the roughening, and the surface shape before the roughening is formed by "copper" Fine concavities and convexities formed by the composite compound." According to this, it is understood that in the case of the surface-treated copper foil of the present application, the surface shape of the copper foil before the roughening of the "fine irregularities made of the copper composite compound" is maintained, and along the surface shape thereof The form is roughened.

Comparison of Example 2 with Comparative Example: Comparison of Example 2 with Comparative Example was carried out with reference to Table 2 below.

In Table 2, focusing on the area ratio of Cu(I) peaks, observation reduction treatment The surface-treated copper foil obtained by using the aqueous solution at pH=11 (sample 11-a, sample 11-b, sample 11-c), and the surface of the aqueous solution used for the reduction treatment at pH=12 The copper foil (the sample 12-a, the sample 12-b, the sample 12-c), and the surface-treated copper foil obtained by the aqueous solution used for the reduction treatment at pH=13 (sample 13-a, sample was carried out) 13-b. When the sample 13-c) was carried out, the occupied area ratio of the Cu(I) peak was in the range of 59% to 99%. On the other hand, the occupied area ratio of the Cu(I) peak of the comparative sample was also 85%. Therefore, regarding the occupied area ratio of the Cu(I) peak, it is understood that the examples and the comparative examples are not different, but when the state analysis by the above XPS is observed, the components detected are different.

Here, the observation sample and the comparative sample are compared by an electron microscope observation image. Rough state. When FIG. 2 is observed, it can be understood that the roughened state of the sample is carried out. Further, when FIG. 3 is observed, the cross-sectional state of the roughened layer of the sample can be understood. On the other hand, in the comparative example, the electron microscope observation image of the roughened state shown in Fig. 4 (a) immediately after the blackening treatment showed a long, thick needle-like shape, and the end portion was sharp before the blackening treatment. Further, the thickness of the roughened layer formed in the needle shape is 500 nm to 700 nm. However, when the reduction blackening treatment is performed after the reduction treatment, the end portion before the unevenness is rounded as shown in FIG. 4(b), and it can be understood that the roughened shape is largely changed by the reduction treatment.

Furthermore, FIG. 5(a) shows the roughening after the blackening treatment in the comparative example. The profile of the layer. Further, Fig. 5(b) shows a cross section after the reduction blackening treatment after the reduction treatment. As is apparent from Fig. 5, the reduction treatment causes considerable damage to the uneven shape before reduction. That is, it can be seen that the needle shape formed by the oxidation treatment is changed by the reduction treatment. Fine and fine breakage. On the other hand, the roughened shape of the "fine concavities and convexities formed by the composite compound" in the examples can be understood from the cross section of Fig. 3, and even if the reduction treatment is carried out, no damage is caused. Accordingly, compared with the sample to be tested, the unevenness of the comparative sample after the reduction treatment is very brittle, and it is predicted that the problem of so-called falling powder may occur.

Therefore, the tearing of the surface-treated copper foil obtained in Example 2 and the comparative example Compare the intensity. As a result, the tear strength of the sample to be tested was 0.70 kgf/cm to 0.81 kgf/cm. On the other hand, the peeling strength of the comparative sample was 0.33 kgf/cm, which was lower than that of the sample.

[Industrial availability]

The surface treated copper foil of the present application shown above is "maximum length" When the fine concavities and convexities formed by the copper composite compound of 500 nm or less are coarsened, if the adhesion of the non-roughened copper foil to the insulating resin substrate is compared, the adhesion to the insulating resin substrate can be ensured. Sex. Further, in the surface-treated copper foil of the present application, "the fine concavities and convexities formed by the copper composite compound having a maximum length of 50 nm or less are extremely fine", so that it is considered that only an extremely long etching time can be provided in the etching process. This is accomplished, and it is expected to form a fine circuit having a good etching factor. Accordingly, it can be usefully used in all printed wiring board products. Further, as described above, the surface-treated copper foil of the present application may be in the form of being roughened on both sides of the copper foil, and may be a double-faced roughened copper foil suitable for forming an inner layer circuit of the multilayer printed wiring board.

Claims (7)

A surface-treated copper foil characterized by a surface-treated copper foil having a roughened surface on a surface of the copper foil, which is provided on the surface of the copper foil and extends from the surface of the copper foil in a cross section, and is made of copper containing copper oxide and cuprous oxide. a roughened layer formed by a composite compound and having a needle-like or plate-like fine unevenness having a maximum length of 350 nm or less, and a needle-like or plate-like fine layer formed of a copper composite compound containing copper oxide and cuprous oxide. In the unevenness system, when the total area of each of the peak areas of CU (I) and Cu (II) in the XPS analysis is 100%, the occupied area ratio of the Cu (I) peak is 50% or more and 99% or less. The surface-treated copper foil according to claim 1, wherein the acicular or plate-like fine concavities and convexities formed by the copper composite compound containing copper oxide and cuprous oxide are confirmed to have a -COO group by XPS analysis. The surface-treated copper foil according to claim 2, wherein the copper composite compound containing copper oxide and cuprous oxide contains copper carbonate. The surface-treated copper foil according to any one of claims 1 to 3, wherein the copper composite compound is observed from the surface of the roughened layer by a scanning electron microscope at a magnification of 45° or more of 50,000 times or more of the sample. The maximum length of the fine needle-like or plate-like fine irregularities is 150 nm or less. The surface-treated copper foil according to any one of claims 1 to 3, wherein the specific surface area measured by the krypton of the needle-like or plate-like fine irregularities formed by the copper composite compound is 0.035 m ² / g or more. The surface-treated copper foil according to any one of claims 1 to 3, wherein the roughened layer has a surface having a L*a*b* color system having a luminance L* of 25 or less. A copper-clad laminate, characterized by using a table as claimed in any one of claims 1 to 6. The surface of the copper foil is obtained.