TW202403117A - Surface treated copper foil, copper foil roll, copper clad laminate, and printed wiring board - Google Patents

Abstract

This surface-treated copper foil has one surface (A) and the other surface (B), wherein the surface (A) satisfies the following requirements (I) and (II). Requirement (I): on the surface of the surface-treated copper foil, the mirror surface glossiness ratio R(75 DEG) [GsMD (75 DEG)/GsTD (75 DEG)], as measured according to JIS Z 8741:1997, of the 75-degree mirror surface glossiness GsMD (75 DEG) of MD to the 75-degree mirror surface glossiness GsTD (75 DEG) of TD is 0.90-1.60 inclusive. Requirement (II): the developed area ratio (Sdr) as measured by a laser microscope on the surface of the surface-treated copper foil is 3.00% or less.

Description

Surface treated copper foil, copper foil rolls, copper sheet laminated boards, and printed circuit boards

The present invention relates to surface-treated copper foil, copper foil rolls made of the surface-treated copper foil, and copper sheet laminates and printed circuit boards containing the surface-treated copper foil.

Surface-treated copper foil can be used in various applications such as secondary batteries such as lithium-ion secondary batteries or printed circuit boards.

Generally, copper foil is easily oxidized, so antirust treatment generally involves applying antirust treatment (metal antirust treatment) using metals such as Zn (zinc) or Cr (chromium) on the surface, or using organic compounds containing Si (silicon), etc. Anti-rust treatment of organic materials (organic anti-rust treatment). For example, Patent Document 1 proposes that a surface-treated copper foil having rust resistance and discoloration resistance has an organic layer provided on the copper foil. [Prior technical literature] [Patent Document]

[Patent Document 1] Japanese Patent Application Publication No. 2021-028165

[Problem to be solved by the invention]

A certain anti-rust effect can be expected from the above-mentioned anti-rust treatment. However, there are cases where copper foil is stored for a long period of time, for example, from 3 months to 1 year after production. In this case, even if the surface-treated copper foil is subjected to the above-mentioned anti-rust treatment, the surface may still be discolored. This discoloration is more obvious when stored in a high-humidity environment.

Surface discoloration of surface-treated copper foil can be considered to be mainly caused by oxidation of the copper foil surface. It not only causes poor appearance of copper foil products, but also causes the hidden problem of deteriorating the performance of the product itself.

Therefore, an object of the present invention is to provide a method that can effectively suppress discoloration of the surface of a surface-treated copper foil even when the surface-treated copper foil is stored for a long time (for example, about 3 months to 1 year) regardless of the humidity of the storage environment. , surface-treated copper foil suitable for long-term storage, copper foil rolls made of the surface-treated copper foil, and copper laminates and printed circuit boards containing the surface-treated copper foil. [Methods to solve problems]

The main components of the present invention are as follows: [1] A surface-treated copper foil having one side (A) and the other side (B); the aforementioned side (A) satisfies the following requirements (I) and (II) ): ・Requirement (I): On the surface of the aforementioned surface-treated copper foil, the 75-degree specular gloss Gs _MD (75°) of MD measured in accordance with JIS Z 8741:1997 is compared to the 75-degree specular gloss Gs _TD of TD. The specular gloss ratio R (75°) [Gs _MD (75°)/Gs _TD (75°)] of (75°) is 0.90 or more and 1.60 or less.・Requirement (II): The developed area ratio (Sdr) measured by a laser microscope on the surface of the aforementioned surface-treated copper foil is 3.00% or less. [2] The surface-treated copper foil as described in the above [1], wherein the above-mentioned surface (B) further satisfies the following requirements (III) and (IV): ・Requirement (III): on the surface of the above-mentioned surface-treated copper foil , the specular gloss ratio R (75°) of MD's 75-degree specular gloss Gs _MD (75°) to TD's 75-degree specular gloss Gs _TD (75°) measured in accordance with JIS Z 8741:1997 _MD (75°)/Gs _TD (75°)] is 0.60 or more and 1.50 or less.・Requirement (IV): The developed area ratio (Sdr) measured by a laser microscope on the surface of the aforementioned surface-treated copper foil is 300% or less. [3] The surface-treated copper foil according to the above [1] or [2], wherein: in the aforementioned requirement (I), the aforementioned specular gloss ratio R (75°) [Gs _MD (75°)/Gs _TD (75°)] is 0.95 or more and 1.50 or less. [4] The surface-treated copper foil according to any one of [1] to [3] above, wherein the Zn adhesion amount on the surface (A) is 0.001 mg/dm ² or more and 0.800 mg/dm ² or less, or the Cr adhesion amount is 0.001 mg/dm ² or more and 0.500 mg/dm ² or less. [5] The surface-treated copper foil according to any one of claims 1 to 4, wherein the Si adhesion amount on the surface (A) is 0.001 mg/dm ² or more and 0.500 mg/dm ² or less. [6] The surface-treated copper foil according to any one of [2] to [5] above, wherein in the above requirement (IV), the developed area ratio (Sdr) is 120% or less. [7] The surface-treated copper foil according to the above [6], wherein in the above requirement (IV), the developed area ratio (Sdr) is 3.00% or less. [8] The surface-treated copper foil according to any one of [1] to [7] above, which is an electrolytic copper foil. [9] The surface-treated copper foil according to the above [8], wherein the surface (A) is a surface derived from the surface on which the rotating drum-shaped cathode is peeled off. [10] A copper foil roll made of the surface-treated copper foil according to any one of the above [1] to [9]; with the aforementioned surface (A) as the outer side, the aforementioned surface It is wound with the surface (A) in contact with the aforementioned surface (B). [11] A copper laminated board including the surface-treated copper foil according to any one of the above [1] to [9]. [12] The copper laminated board according to the above [11], wherein: the aforementioned surface (B) is the surface bonded to the resin base material. [13] A printed circuit board including the surface-treated copper foil according to any one of [1] to [9] above. [Effects of the invention]

The present invention can provide: regardless of the humidity of the storage environment, even if the surface-treated copper foil is stored for a long time, the discoloration of the surface of the copper foil can still be effectively suppressed, and the surface-treated copper foil is suitable for long-term storage. The surface-treated copper foil The produced copper foil roll, and the copper laminated board and printed circuit board containing the surface-treated copper foil.

Embodiments of the surface-treated copper foil, copper foil roll, copper sheet laminated board, and printed circuit board of the present invention will be described in detail below. It is worth noting that in this specification, regarding the description of numerical values, the term "A to B" means "above and below B" (when A<B) or "a below and above B" (A> B situation). Furthermore, in the present invention, a combination of preferred aspects is a more preferred aspect.

[Surface-treated copper foil] The surface-treated copper foil of the present invention (hereinafter may be simply referred to as "copper foil") is a surface-treated copper foil having one side (A) and the other side (B), and is characterized by: , the aforementioned surface (A) is characterized by satisfying the following requirements (I) and (II): ・Requirement (I): The surface of the aforementioned surface-treated copper foil has a 75-degree mirror surface with MD measured in accordance with JIS Z 8741:1997 The specular gloss ratio R (75°) _[ Gs _MD (75°)/Gs _{TD (75°)] of the 75-degree specular gloss Gs TD (} 75°) relative to TD is 0.90 Above and below 1.60; ・Requirement (II): The developed area ratio (Sdr) measured by a laser microscope on the surface of the aforementioned surface-treated copper foil is 3.00% or below. Here, MD (Machine Direction) is the direction in which the copper foil base flows (may also be called RD (Roll Direction)) when manufacturing the copper foil base (may also be called "original foil"), while TD (Transverse Direction) is the vertical direction. in the direction of MD.

The present invention can obtain: regardless of the humidity of the storage environment, even if the surface-treated copper foil is stored for a long time, the discoloration of the surface of the copper foil can still be effectively suppressed, and the surface-treated copper foil is suitable for long-term storage. The detailed reason for obtaining this effect is not clear, but one of the reasons is considered to be as follows.

First, the present inventors studied the results of discoloration on the copper foil surface in detail, and speculated that the main reasons are as follows. Usually, anti-rust treatment is applied to the surface of copper foil. However, during long-term storage, due to mutual diffusion or alloying between the copper foil base and the anti-rust treatment layer, copper may be exposed on the surface, and the surface of the copper foil may be oxidized. In particular, the surface of the copper foil has stripe-like irregularities extending along the MD caused by the treatment performed during the manufacturing process. Depending on the slight uneven shape, the thickness of the anti-rust treatment will be different, so the anti-rust ability will vary depending on the thickness. As a result, it is considered that the thin portions present in the stripe-shaped anti-rust treatment are prone to copper oxidation during long-term storage. In addition, in particular, organic anti-rust treatment is difficult to achieve uniform treatment, and treatment unevenness is likely to occur along the MD. Therefore, there may be places along the MD that are not covered with rust-proof material or places where the coverage thickness is very thin. It can be considered that copper oxidation is prone to occur in this kind of place during long-term storage. As mentioned above, after long-term storage, stripe-like discoloration along the MD (hereinafter may be referred to as "MD stripe discoloration") may occur in the portions of the copper foil surface that are prone to copper oxidation. MD stripe discoloration is the main cause of discoloration on the surface of copper foil that occurs when copper foil is stored for a long time. Moreover, the smoother the copper foil surface is, the easier it is to visually confirm the above-mentioned MD stripe-like discoloration.

On the other hand, the discoloration of the copper foil surface is usually greatly affected by the humidity of the storage environment. For example, in a dehumidified environment such as a dryer, the rate of discoloration on the copper foil surface can be suppressed. It is believed that this is because in an environment with high humidity, local cells are formed on the surface of the copper foil, and oxidation of copper is prone to occur, but dehumidification can inhibit its occurrence. However, it is actually difficult to keep copper foil products in a dehumidified environment. Therefore, it is desired to suppress the discoloration of the copper foil surface even if it is not in a dehumidified environment.

Therefore, as a result of repeated diligent research, the present inventors found that by controlling the surface of one side (A) of the copper foil to have the above-specified surface shape, it is possible to effectively prevent defects that occur especially when the copper foil is stored for a long period of time. MD stripe-like discoloration on the surface of copper foil. The detailed mechanism is not yet clear, but by setting the surface (A) of the copper foil to a smooth surface with a developed area ratio (Sdr) of 3.00% or less (requirement (II)), and setting it to a specular gloss ratio R (75°) It is considered that it is an anisotropic surface (requirement (I)) between 0.90 and 1.60, which can effectively suppress the difference in treatment thickness or uneven treatment caused by the anti-rust treatment of surface (A). Suppresses copper oxidation during long-term storage.

In addition, the surface-treated copper foil of the present invention is suitable for use in printed circuit boards, for example. In the case of using the surface-treated copper foil of the present invention, excellent transfer characteristics can be achieved.

The surface-treated copper foil of the present invention will be described in detail below.

First, in the surface-treated copper foil of the present invention, one surface between the front and rear surfaces is defined as "surface (A)", and the other surface is defined as "surface (B)". That is, the surface-treated copper foil of the present invention has one side (A) and the other side (B) (hereinafter may be simply referred to as "side (A)" and "side (B)"). Furthermore, the surface-treated copper foil of the present invention has a surface-treated film including an anti-rust treatment layer on both sides (surface (A) and surface (B)) of the copper foil base. The anti-rust treatment layer may be a layer that has the effect of inhibiting the oxidation of copper. It may be a treatment layer resulting from metal anti-rust treatment or an organic anti-rust treatment, or they may be used in combination.

In addition, the above-mentioned surface treatment film may further include a roughening treatment layer. In particular, in the surface (B), it is preferable that the surface treatment film includes a roughening treatment layer. The roughening treatment layer is formed by forming roughened particles on the surface of the copper foil substrate. In addition, if necessary, the above-mentioned surface treatment film may also include other layers. It is worth noting that in faces (A) and (B), the layer composition of each surface treatment film may be the same or different. In addition, the surface of the surface-treated copper foil refers to the outermost surface (the surface and the back) of the surface-treated copper foil, that is, the surface of the surface-treated film.

In addition, the above-mentioned copper foil base may also be an electrolytic copper foil or a rolled copper foil, and is preferably an electrolytic copper foil. The thickness of the copper foil base is, for example, 5 to 210 μm, preferably 10 to 70 μm. In addition, when the copper foil base is an electrolytic copper foil, the surface-treated copper foil may be an electrolytic copper foil, and the surface (A) may be a rotating drum-shaped cathode (hereinafter referred to as "drum-shaped cathode") peeled from the electrolytic copper foil. The surface derived from the surface (hereinafter referred to as the "roller surface") may also be the surface on the opposite side of the roller surface (hereinafter referred to as the "non-roller surface"), but the roller surface is preferred. An example of the manufacturing method of electrolytic copper foil is shown and demonstrated below.

Figure 1 is a schematic diagram of an electrolytic copper foil manufacturing device. The electrode is composed of a rotating drum-shaped cathode 1 made of titanium or stainless steel and an insoluble anode 2 such as an electrode covered with a precious metal oxide or a lead electrode facing each other in a concentric circle. Between the two electrodes, the copper sulfate electrolyte 3 flows from the bottom of the device, and by applying electric current, copper plating is deposited on the surface of the drum-shaped cathode. The drum-shaped cathode 1 rotates at a specified speed, and the deposited copper plating is continuously peeled off from the surface of the drum-shaped cathode and wound into an electrolytic copper foil 6 . In the electrolytic copper foil 6 , the drum-shaped cathode surface side is called the drum surface 5 , but it may also be generally called the glossy surface (S surface). In addition, the surface opposite to the roller surface 5 is called the non-roller surface 4, but it may also be generally called a precipitation surface or a rough surface (M surface).

<Side (A)> The surface (A) of the surface-treated copper foil is the surface (surface) on one side of the surface-treated copper foil, that is, the surface of the copper foil base has a surface-treated film including an anti-rust treatment layer. noodle. The transmission surface (A) of the present invention satisfies the following requirements (I) and (II) and can prevent MD stripe-like discoloration on the copper foil surface.・Requirement (I): On the surface of the above-mentioned surface-treated copper foil, the 75-degree specular gloss Gs _MD (75°) of MD measured in accordance with JIS Z 8741:1997 relative to the 75-degree specular gloss Gs _TD (75) of TD °), the specular gloss ratio R (75°) [Gs _MD (75°)/Gs _TD (75°)] is 0.90 or more and 1.60 or less.・Requirement (II): The developed area ratio (Sdr) measured by a laser microscope on the surface of the aforementioned surface-treated copper foil is 3.00% or less.

(Element (I)) The present invention focuses on the stripe-like unevenness in the MD of the copper foil surface caused by the treatment performed in the manufacturing process. However, these stripe-like unevennesses are very fine, so it is difficult to evaluate them appropriately using conventional copper foil surface observation techniques alone. For example, since the copper foil surface is observed from the vertical direction using a laser microscope or a white interference microscope, it is difficult to accurately express the characteristics of a surface having very fine unevenness. In addition, it is difficult to accurately define the three-dimensional characteristics of a surface with fine unevenness through direct two-dimensional shape observation such as cross-sectional observation using a scanning electron microscope (SEM). Therefore, only conventional methods have limitations in strictly evaluating the copper foil surface from a technical perspective. Therefore, in the present invention, one method of evaluating the copper foil surface is to define the characteristics of the copper foil surface based on the specular glossiness measured in accordance with JIS Z 8741:1997. Specifically, it is carried out according to the following methods.

Usually, the measurement of specular gloss is generally measured and evaluated from one direction at a single light receiving angle. However, the surface of the surface-treated copper foil of the present invention is very smooth, so it is difficult to fully evaluate the surface shape when measured from one direction. Therefore, the present inventors focused on a method of measuring the specular glossiness from both the MD and TD directions using specified light receiving angles, calculating the ratio, and evaluating the anisotropy of the surface shape of the copper foil based on this. However, the light receiving angle when measuring specular gloss has hitherto been generally evaluated based on 60 degrees or 85 degrees. However, in this case, it is difficult to appropriately evaluate the anisotropy of the surface shape of the copper foil. For example, in the case where the light receiving angle is 60 degrees, the incident angle of light is small, so a very smooth surface such as the surface of the copper foil of the present invention cannot be appropriately evaluated. In addition, when the light receiving angle is 85 degrees, the sensitivity of the surface shape is too high, so the difference in specular gloss measured from two directions is small, and it is not appropriate to calculate and evaluate the specular gloss ratio from two directions. Therefore, the present inventors found that focusing on the light-receiving angle when measuring specular glossiness is 75 degrees, measuring the specular glossiness in both directions of MD and TD at this light-receiving angle, calculating and evaluating the ratios, and based on this, the present inventors have found that The anisotropy of the surface shape of a very smooth copper foil surface that has been difficult to appropriately evaluate until now can be appropriately evaluated.

Surface (A) On the surface of the surface-treated copper foil, the 75-degree specular gloss Gs _MD (75°) of MD measured in accordance with JIS Z 8741:1997 relative to the 75-degree specular gloss Gs _TD (75°) of TD The specular gloss ratio R (75°) [Gs _MD (75°)/Gs _TD (75°)] is 0.90 or more and 1.60 or less. It is considered that the specular gloss ratio R (75°) represents the anisotropy of the surface shape of the copper foil surface. If the specular gloss ratio R (75°) is outside the above range, MD stripe discoloration is likely to occur during long-term storage, especially in a high-humidity environment. The specular gloss ratio R (75°) is preferably 0.95 or more and 1.50 or less, more preferably 0.95 or more and 1.40 or less, still more preferably 0.95 or more and 1.30 or less. It is worth noting that the 75-degree specular gloss Gs _TD (75°) of TD is, for example, 30% or more and 250% or less, and preferably 80% or more and 220% or less. Moreover, the 75-degree specular gloss Gs _MD (75°) of MD is, for example, 80% or more and 300% or less, preferably 150% or more and 250% or less. It is worth noting that each of the above specular gloss Gs can be measured by the method described in the embodiment.

(Element (II)) As mentioned above, surface (A) is a very smooth surface. The developed area ratio (Sdr) of this surface (A) on the surface of the surface-treated copper foil measured by a laser microscope is 3.00% or less. If the developed area ratio (Sdr) is outside the above range, MD stripe discoloration is likely to occur during long-term storage, especially in a high-humidity environment. The development area ratio (Sdr) is preferably 1.50% or less, more preferably 1.00% or less. It is worth noting that the lower limit is, for example, 0.01% or more. It is worth noting that the developed area ratio (Sdr) can be measured by the method described in the embodiment.

The surface (A) that satisfies the above-mentioned surface shape is preferably a surface obtained by subjecting the surface of the copper foil base to a planarization process. By applying this kind of treatment, the surface shape of surface (A) can be easily controlled within a desired range.

In addition, the surface (A) is a surface having a surface treatment film including an anti-rust treatment layer. The anti-rust treatment layer can be formed by metal anti-rust treatment or organic anti-rust treatment using an organic compound containing Si or the like.

At least in the case where the above-mentioned anti-rust treatment layer is a treatment layer produced by metal anti-rust treatment, the anti-rust treatment layer preferably contains at least one of Zn and Cr. When the anti-rust treatment layer contains at least one of Zn and Cr, the adhesion amounts of Zn and Cr on the surface (A) can be set to 1.000 mg/dm ² or less, for example. Moreover, from the viewpoint of effectively suppressing discoloration of the copper foil surface, the Zn adhesion amount on the surface (A) is preferably 0.001 mg/dm ² or more and 0.800 mg/dm ² or less, or the Cr adhesion amount is preferably 0.001 mg. /dm ² or more and 0.500mg/dm ² or less. Here, from the viewpoint of more effectively suppressing discoloration of the copper foil surface, the Zn adhesion amount is more preferably 0.005 mg/dm ² or more and 0.800 mg/dm ² or less. Moreover, from the viewpoint of more effectively suppressing discoloration of the copper foil surface, the Cr adhesion amount is more preferably 0.005 mg/dm ² or more and 0.500 mg/dm ² or less. In addition, from the viewpoint of more effectively suppressing the discoloration of the copper foil surface, the anti-rust treatment layer preferably contains both Zn and Cr, and the adhesion amounts of Zn and Cr on the surface (A) are preferably within the above ranges. .

Furthermore, at least when the anti-rust treatment layer is a treatment layer produced by an organic anti-rust treatment, the anti-rust treatment layer preferably contains Si (silicon). When the anti-rust treatment layer contains Si, the Si adhesion amount on the surface (A) can be set to 1.000 mg/dm ² or less, for example. Moreover, from the viewpoint of effectively suppressing discoloration of the copper foil surface, the Si adhesion amount on the surface (A) is preferably 0.001 mg/dm ² or more and 0.500 mg/dm ² or less, more preferably 0.003 mg/dm ² or more And less than 0.500mg/ ^dm2 .

In addition, from the perspective of improving the anti-rust effect, the above-mentioned anti-rust treatment layer may also include both a treatment layer produced by metal anti-rust treatment and a treatment layer produced by organic anti-rust treatment. In this case, the surface treatment The film preferably contains at least one of Zn and Cr and Si. At this time, it is preferable that the adhesion amounts of Zn, Cr, and Si on the surface (A) are within the above ranges.

Furthermore, from the viewpoint of being free of Cr, it is preferable that the anti-rust treatment layer is mainly formed using an organic anti-rust agent. In this case, in face (A), the surface treatment film preferably contains Si, and more preferably It does not contain Cr substantially. Specifically, in the surface (A), the Si adhesion amount is preferably within the above range, and the Cr adhesion amount is more preferably less than 0.001 mg/dm ² .

It is worth noting that the adhesion amount of each component of surface (A) can be measured by the method described in the examples.

＜Side (B)＞ The surface (B) of the surface-treated copper foil is the other surface (back) to the above-mentioned surface (A) among the front and back surfaces of the surface-treated copper foil.

In the surface-treated copper foil of the present invention, the surface shape of the surface (B) can be adjusted appropriately. For example, the surface (B) is preferably on the surface of the surface-treated copper foil, and the MD measured according to JIS Z 8741:1997 is 75 Specular gloss ratio R (75°) of 75-degree specular gloss Gs _MD (75°) relative to TD Specular gloss Gs _TD (75°) [Gs _MD (75°)/Gs _TD (75°)] is 0.50 or more and 1.60 or less, and the developed area ratio (Sdr) measured by a laser microscope is 310% or less. Moreover, from the viewpoint of further suppressing discoloration of the copper foil surface, surface (B) more preferably satisfies the following requirements (III) and (IV).

Usually, copper foil products are generally manufactured and stored in roll form. In the state of being wound into a roll, the surface (A) and the surface (B) are arranged to face each other. When the copper foil is stored in this state, friction may occur with the surface (A) depending on the surface shape of the surface (B). As a result, even if metal anti-rust treatment or organic anti-rust treatment is applied to surface (A), due to contact with surface (B), the anti-rust treatment layer may still be partially scraped off, and the copper will be exposed (uneven friction). In the long term, Oxidation occurs during storage, causing discoloration on the surface of the copper foil.

As a result of diligent research on the discoloration on the surface of this type of copper foil, the inventors found that the transmission surface (B) satisfies the following requirements (III) and (IV) and can reduce the amount of discoloration from surface (B) to surface (A). The friction can prevent discoloration caused by uneven friction with surface (A).

That is, in the present invention, from the viewpoint of further suppressing discoloration of the copper foil surface, surface (B) preferably satisfies the following requirements (III) and (IV).・Requirement (III): On the surface of the above-mentioned surface-treated copper foil, the 75-degree specular gloss Gs _MD (75°) of MD measured in accordance with JIS Z 8741:1997 relative to the 75-degree specular gloss Gs _TD (75) of TD °), the specular gloss ratio R (75°) [Gs _MD (75°)/Gs _TD (75°)] is 0.60 or more and 1.50 or less.・Requirement (IV): The developed area ratio (Sdr) measured by a laser microscope on the surface of the aforementioned surface-treated copper foil is 300% or less.

(Requirement (III)) On the surface of the surface (B) of the surface-treated copper foil, the 75-degree specular gloss Gs of MD measured in accordance with JIS Z 8741:1997 MD (75°) The 75-degree specular gloss Gs of _MD (75°) relative to TD The specular gloss ratio R (75°) of _TD (75°) [Gs _MD (75°)/Gs _TD (75°)] is preferably 0.60 or more and 1.50 or less. If the specular gloss ratio R (75°) is within the above range, discoloration caused by uneven friction with surface (A) can be effectively suppressed. The specular gloss ratio R (75°) is preferably 0.70 or more and 1.40 or less, and still more preferably 0.80 or more and 1.30 or less. It is worth noting that the 75-degree specular gloss Gs _TD (75°) of TD is, for example, 0.5% or more and 250% or less, and preferably 10% or more and 220% or less. Moreover, the 75-degree specular gloss Gs _MD (75°) of MD is, for example, 0.5% or more and 300% or less, and preferably 10% or more and 250% or less. It is worth noting that each of the above specular gloss Gs can be measured by the method described in the embodiment.

(Element (IV)) Moreover, it is also preferable that surface (B) is a smooth surface. The developed area ratio (Sdr) of the surface (B) on the surface of the surface-treated copper foil measured by a laser microscope is preferably 300% or less. If the developed area ratio (Sdr) is 300% or less, discoloration caused by uneven friction with surface (A) can be effectively suppressed. Moreover, the development area ratio (Sdr) is preferably 120% or less, more preferably 10.0% or less, and still more preferably 3.00% or less. In particular, by setting the developed area ratio (Sdr) to preferably 120% or less, more preferably 3.00% or less, the transfer characteristics can be further improved when used for printed circuit boards. In addition, by setting the developed area ratio (Sdr) to 3.00% or less, both sides (A) and (B) can be made into very smooth surface-treated copper foil. Moreover, the lower limit is, for example, 0.01% or more. It is worth noting that the developed area ratio (Sdr) can be measured by the method described in the embodiment.

＜Manufacturing method of surface-treated copper foil＞ Next, one example of a preferable manufacturing method of the surface-treated copper foil of this invention is demonstrated.

It is preferable to apply planarization treatment on the surface of the copper foil base body corresponding to the side (A) as a post-processing for the copper foil base body (original foil). For example, by applying planarization treatment under the following conditions, the surface shape of surface (A) can be made to satisfy the above requirements (I) and (II).

(copper foil base) It is preferable to use an electrolytic copper foil or a rolled copper foil which has a smooth and glossy surface without coarse unevenness as a copper foil base. Among them, from the viewpoint of productivity or cost, it is preferable to use electrolytic copper foil. In particular, it is preferable to use the drum surface of electrolytic copper foil for the surface corresponding to the surface (A). From the viewpoint of obtaining a roll surface shape suitable for forming surface (A) that satisfies requirements (I) and (II), the roll-shaped cathode surface used for electrolytic copper foil production is preferably #1000 to #2500. Polishing paste for grinding.

[Processing for the face corresponding to face (A)] From the viewpoint of making the surface shape of the surface (A) satisfy the above-mentioned requirements (I) and (II), it is preferable to apply a planarization process to the surface of the copper foil base corresponding to the surface (A). Moreover, it is more preferable that the flattening process is performed before the rust-proofing process, and it is more preferable that it is performed in the order of [A1] flattening process and [A2] rust-proofing process.

[A1] Flattening treatment Planarization treatment includes DC anode dissolution using copper pyrophosphate solution. Taking DC anode dissolution using copper pyrophosphate liquid as an example, suitable treatment conditions are illustrated below. It is worth noting that the following conditions are a preferred example of the flattening process. Other processes can also be performed within the scope that does not hinder the effects of the present invention. If necessary, the type or amount of additives can be appropriately changed or adjusted. Electrolysis conditions, etc.

・For DC anode dissolution using a copper pyrophosphate solution, it is preferable to use a copper pyrophosphate aqueous solution having the following electrolyte composition and perform DC anode dissolution under the following conditions. By satisfying the following conditions, the surface shape of surface (A) can satisfy the above requirements (I) and (II). <Electrolyte composition (copper pyrophosphate aqueous solution)> Copper pyrophosphate trihydrate: 70～120g/L Potassium pyrophosphate: 300～400g/L Ammonia: 0.25～1.3g/L Potassium ethyl xanthate: 10～30mg/ L ＜Cathode and Anode＞ Cathode: Oxygen-free copper Anode: Copper foil base surface corresponding to surface (A) ＜Electrolysis conditions＞ Liquid temperature: 15～55℃ Current density: 5～65A/dm ² Dissolution time: 3～80 Second charge density: 30.0～1800.0C/dm ²

〔A2〕Anti-rust treatment The anti-rust treatment is preferably applied to the surface (A) after the above-mentioned flattening treatment. The anti-rust treatment may be either metal anti-rust treatment or organic anti-rust treatment. Examples of each suitable processing condition are shown below. It is worth noting that the following conditions are a preferred example, and the type or amount of additives and electrolysis conditions can be appropriately changed and adjusted if necessary within the scope that does not hinder the effects of the present invention.

・Metal anti-rust treatment Metal anti-rust treatment includes metal plating treatment produced by Ni, Zn, Cr, etc. Among them, Zn electroplating treatment and Cr electroplating treatment are suitable. This kind of metal anti-rust treatment can appropriately select the specified metal plating treatment according to the use or purpose of the surface-treated copper foil. If necessary, through combination, a metal anti-rust treatment layer with the required composition can be formed. The metal anti-rust treatment layer can also be a single layer, or it can also be multiple layers of two or more layers. Specific examples of the multilayer include a metal barrier having a two-layer structure of a layer containing Zn and a layer containing Cr, or a three-layer structure of a layer containing Ni, a layer containing Zn, and a layer containing Cr. Rust treatment layer.

The layer containing Zn is preferably formed when heat resistance must be further improved. The Zn-containing layer (heat-resistant layer) is preferably made of, for example, zinc or a zinc-containing alloy, that is, selected from zinc (Zn)-tin (Sn), zinc (Zn)-nickel (Ni), zinc (Zn)- It is formed of at least one alloy containing zinc among cobalt (Co), zinc (Zn)-copper (Cu), zinc (Zn)-chromium (Cr), and zinc (Zn)-vanadium (V).

The layer containing Cr is preferably formed when corrosion resistance must be further improved. The layer containing Cr (corrosion-resistant layer) includes, for example, a chromium layer formed by Cr plating and a chromate layer formed by chromate treatment.

For example, in the case where copper (Cu) in the copper foil base or roughened layer may diffuse to the resin base material side, causing copper damage and reducing adhesion, the layer containing Ni is preferably formed on the copper foil base or roughened layer. Between the roughening treatment layer and the silane coupling agent layer. The layer containing Ni (lower layer) is preferably formed of at least one selected from the group consisting of nickel (Ni), nickel (Ni)-phosphorus (P), and nickel (Ni)-zinc (Zn).

・Organic anti-rust treatment The organic anti-rust treatment includes anti-rust treatment using an organic anti-rust agent, but specifically, anti-rust treatment using an organic compound containing Si is suitable. The organic compound containing Si preferably contains styrylsilane, aminosilane, vinylsilane, methacrylic silane, acrylic silane, styrylsilane, ureidosilane, mercaptosilane, sulfide silane, imidazole silane, and isocyanate silane Any one or more silane coupling agents.

In addition, the method of forming an organic anti-rust treatment layer through organic anti-rust treatment includes, for example, applying an organic compound solution directly or through a metal anti-rust treatment layer on the surface (A) after the above-mentioned planarization treatment, and then air-drying (naturally) drying) or heat drying. The applied organic compound solution forms an organic anti-rust treatment layer through the evaporation of the solvent (such as water) in the solution. It is worth noting that when the organic compound containing Si is a silane coupling agent, heating and drying at 50 to 180°C is suitable because the reaction between the silane coupling agent and the copper foil can be accelerated.

It is worth noting that the thickness of the above-mentioned anti-rust treatment layer is very thin, so it does not affect the surface shape of the surface-treated copper foil. Therefore, the surface shape of the surface-treated copper foil is essentially determined by the shape before anti-rust treatment, for example, the shape of the surface (A) after the above-described planarization treatment.

[Processing for the face corresponding to face (B)] It is preferable to apply anti-rust treatment to the surface of the copper foil base corresponding to surface (B). If necessary, roughening treatment or flattening treatment can also be applied before anti-rust treatment. The anti-rust treatment and the flattening treatment can be performed under the conditions illustrated in the treatment for the surface corresponding to surface (A). In addition, the suitable treatment conditions for the roughening treatment are exemplified as follows, but the following conditions are a preferred example, and the type or amount of additives and electrolysis conditions can be appropriately changed and adjusted if necessary within the scope that does not hinder the effects of the present invention. . Moreover, when performing a roughening process, it is preferable to perform it in the order of [B1] roughening process and [B2] rust-proofing process.

〔B1〕Roughening treatment The roughening treatment is preferably performed on the surface of the copper foil base corresponding to the surface (B) in a roll-to-roll manner, using a two-stage electroplating process of roughening electroplating treatment and fixed electroplating treatment to form a roughened treatment layer. Suitable conditions for roughening plating treatment and fixing plating treatment are as follows. It is worth noting that by satisfying the following conditions, the surface shape of surface (B) can be controlled to the above-mentioned appropriate shape.

・For roughening plating treatment, it is preferable to use the following copper sulfate aqueous solution and perform plating treatment under the following conditions. <Electrolyte composition (copper sulfate aqueous solution)> Copper sulfate pentahydrate: converted from copper (atom), 40 to 80g/L Sulfuric acid: 80 to 200g/L <Electrolysis conditions> Liquid temperature: 15 to 35°C Current density: 5 to 90A/dm ² processing time: 0.5～50 seconds Charge density: 10～500C/dm ² processing speed: 8～20m/min

・For fixed plating treatment, it is preferable to use the following copper sulfate aqueous solution and perform plating treatment under the following conditions. <Electrolyte composition (copper sulfate aqueous solution)> Copper sulfate pentahydrate: converted from copper (atom), 70~150g/L Sulfuric acid: 100~200g/L <Electrolysis conditions> Liquid temperature: 40~60℃ Current density: 1~ 10A/dm ² processing time: 2～20 seconds Charge density: 2～100C/dm ² processing speed: 8～20m/min

〔B2〕Anti-rust treatment The anti-rust treatment can be performed under the conditions illustrated in the treatment for the surface corresponding to surface (A). Specifically, on the surface (B) after the above-mentioned roughening treatment, metal plating is applied in the order of Ni, Zn, and Cr to form a metal anti-rust treatment layer, and then it is preferable to further form an organic anti-rust layer through an organic compound containing Si. Rust treatment layer.

[Copper Foil Roll] The surface-treated copper foil of the present invention is particularly suitable when it is produced in a roll shape, wound up, and stored. The copper foil roll made of the surface-treated copper foil of the present invention is wound with the above-mentioned surface (A) as the outer side and the above-mentioned surface (A) and the above-mentioned surface (B) in contact. The copper foil roll of the present invention can reduce the storage area by storing the surface-treated copper foil in a roll shape. At the same time, the influence of outside air on the surface of the copper foil can be minimized on the inside of the roll, so it is suitable for long-term storage of copper foil.

Furthermore, in conventional copper foil rolls, when the surface and the back of the copper foil are arranged to face each other, friction may occur with the surface depending on the state of the back. As a result, even if metal anti-rust treatment or organic anti-rust treatment is applied to the surface, the anti-rust treatment layer may still be scraped off due to contact with the inside, and the copper will be exposed, oxidized during storage, and discolored on the surface of the copper foil. However, the copper foil roll of the present invention satisfies the above-mentioned requirements (III) and (IV) especially through the above-mentioned surface (B), can reduce the friction from the above-mentioned surface (B) toward the above-mentioned surface (A), and can prevent the above-mentioned surface (A) from interfering with the above-mentioned surface (B). A) Discoloration caused by uneven friction.

[use] The surface-treated copper foil of the present invention is suitable for manufacturing copper laminated boards, and is more suitable for manufacturing printed circuit boards. Copper laminated boards containing the surface-treated copper foil of the present invention are particularly suitable for use in the manufacture of printed circuit boards with excellent transmission characteristics in high frequency bands to exhibit excellent effects. In addition, the printed circuit board containing the surface-treated copper foil of the present invention is suitable for use as a high-frequency band printed circuit board used in a high frequency band (especially a high frequency band of 1 to 100 GHz).

The copper laminated board containing the surface-treated copper foil of the present invention can be formed by conventional methods. Specifically, copper laminated boards are generally manufactured by laminating surface-treated copper foil and a resin base material (insulating substrate) so that the roughened surface (bonding surface) of the surface-treated copper foil faces the resin base material. In particular, when using the surface-treated copper foil of the present invention, in a copper laminated board, the above-mentioned surface (B) is preferably the surface to which the resin base material is adhered. Accordingly, the adhesion to the resin base material is relatively good. Also, in this case, the above-mentioned surface (A) is a resistance surface, so the transmission characteristics can be improved.

In recent years, with the arrival of 5G or beyond5G, copper foil has been required to have better transmission characteristics. Until now, the mainstream method for improving the transmission characteristics of copper foil has been to reduce the size of roughened particles formed on the surface of the copper foil that is adhered to the resin base material. However, in response to the requirements for further improvement of the above-mentioned transfer characteristics, only this solution has its limitations. To further improve the transfer characteristics, effective solutions are needed.

Therefore, as a result of repeated research, the inventors found that the transmission characteristics can be improved by designing not only the surface that adheres to the resin base material of the copper foil, but also the surface shape of the surface that resists it. Specifically, it was found that the transmission characteristics can be improved by using the surface-treated copper foil of the present invention. That is, it was found that the surface-treated copper foil of the present invention is characterized in that the transmission surface (A) satisfies the following requirements (I) and (II), and that the transmission characteristics can be improved by using this surface (A) as a resistance surface.・Requirement (I): On the surface of the above-mentioned surface-treated copper foil, the 75-degree specular gloss Gs _MD (75°) of MD measured in accordance with JIS Z 8741:1997 relative to the 75-degree specular gloss Gs _TD (75) of TD °), the specular gloss ratio R (75°) [Gs _MD (75°)/Gs _TD (75°)] is 0.90 or more and 1.60 or less.・Requirement (II): The developed area ratio (Sdr) measured by a laser microscope on the surface of the aforementioned surface-treated copper foil is 3.00% or less.

It is worth noting that the resin substrate includes, for example, a flexible resin substrate or a hard resin substrate, but the surface-treated copper foil of the present invention is particularly suitable for combination with a hard resin substrate that requires high-frequency transmission characteristics and high adhesion.

Moreover, when manufacturing a copper laminated board for a printed circuit board, the surface-treated copper foil which has a silane coupling agent layer, and a resin base material are bonded together through a hot press, and it may be manufactured accordingly. It is worth noting that a silane coupling agent is coated on the resin base material, and the resin base material coated with the silane coupling agent and the surface-treated copper foil with an anti-rust treatment layer on the outermost surface are bonded through a hot press. The produced copper laminated board for printed circuit boards also has the same effect as when the surface-treated copper foil having the above-mentioned silane coupling agent layer is used.

In addition, the printed circuit board containing the surface-treated copper foil of the present invention can be formed by a conventional method. Specifically, it may be formed using the above-mentioned copper laminated board for printed circuit boards. This type of printed circuit board preferably includes the above-mentioned copper laminated board for printed circuit boards.

In addition, the surface-treated copper foil of the present invention can also be suitably used as a negative electrode current collector for lithium ion secondary batteries and the like. The negative electrode current collector including the surface-treated copper foil of the present invention can be formed by conventional methods. Specifically, carbon particles or the like can be applied to the surface of a copper foil, dried, and further pressed to form a negative electrode active material layer.

The embodiments of the present invention have been described above, but the above-mentioned embodiments are only examples of the present invention. The present invention includes the concept of the present invention and various aspects included in the scope of the patent application, and various changes can be made within the scope of the present invention. [Example]

The present invention will be described in further detail below based on examples, but the following is only an example of the present invention.

(Manufacture Example 1: Preparation of copper foil base) The following cathode and anode were used, and the copper sulfate electrolyte of the following composition was used, and according to the following electrolysis conditions, a roll-shaped electrolytic copper foil (double-sided glossy foil) with a thickness of 18 μm was produced. , as the copper foil base. ＜Cathode and Anode＞ Cathode: Titanium rotating drum whose surface roughness is adjusted by polishing with #1000~#2500 polishing paste. Anode: Dimensional stability anode DSA (registered trademark) ＜Electrolyte composition＞ Copper sulfate pentahydrate: made of Copper (atom) conversion, 80g/L Sulfuric acid: 70g/L Chlorine concentration: 25mg/L (Additive) ・Sodium 3-mercapto-1-propanesulfonate: 2mg/L ・Hydroxyethyl cellulose: 10mg/L ・Low Molecular weight glue (molecular weight 3000): 50mg/L <Electrolysis conditions> Liquid temperature: 55℃ Current density: 45A/dm ²

(Manufacturing Example 2: Preparation of copper foil base) An ingot in which various trace elements are added to oxygen-free copper is repeatedly rolled in a calender to produce a roll-shaped rolled copper foil (double-sided glossy foil) with a thickness of 18 μm as a copper foil base.

(Comparative Production Example 1: Preparation of copper foil base) The following cathode and anode were used, and the copper sulfate electrolyte of the following composition was used, and according to the following electrolysis conditions, a roll-shaped electrolytic copper foil (double-sided glossy foil) with a thickness of 70 μm was produced. ), as the copper foil base. ＜Cathode and Anode＞ Cathode: Titanium rotating drum whose surface roughness is adjusted by polishing with #2000 polishing paste. Anode: Dimensional stability anode DSA (registered trademark) ＜Electrolyte composition＞ Copper sulfate pentahydrate: composed of copper (atoms) ) conversion, 80g/L sulfuric acid: 140g/L chlorine concentration: 25mg/L (additive) ・Bis-3-sulfopropyl disulfide disodium disulfide (SPS): 5mg/L ・DDAC polymer (Senka Co., Ltd., UNISENCE FPA100L): 30mg/L <Electrolysis conditions> Liquid temperature: 50℃ Current density: 60A/dm ²

(Example 1) In Example 1, the electrolytic copper foil produced in Production Example 1 was used as a copper foil base body, and the following processing was performed on the copper foil base body to obtain a surface-treated copper foil. Details are as follows.

[Processing for the face corresponding to face (A)] First, the drum surface of the electrolytic copper foil manufactured in Manufacturing Example 1 of the copper foil base was used as the surface (A). The surface (A) was subjected to the planarization treatment [A1] and [A2] in sequence under the following conditions. Anti-rust treatment.

[A1] Flattening treatment For the surface (A) of the copper foil base, a copper pyrophosphate aqueous solution having the following electrolyte composition was used, and DC anode dissolution was performed under the following conditions as a planarization process. ＜Electrolyte composition (copper pyrophosphate aqueous solution)＞ Copper pyrophosphate trihydrate: 100g/L Potassium pyrophosphate: 350g/L Ammonia: 0.75g/L Potassium ethyl xanthate: 20mg/L ＜Cathode and Anode＞ Cathode: oxygen-free copper Anode: The drum surface of the electrolytic copper foil produced in Production Example 1 ＜Electrolysis conditions＞ The liquid temperature, anode current density, dissolution time, and charge density of the electrolyte are as shown in Table 1.

〔A2〕Anti-rust treatment As for the surface (A) after the above-mentioned [A1] planarization process, an organic anti-rust treatment was applied under the following conditions as anti-rust treatment. ・Organic anti-rust treatment On the surface (A) after the planarization treatment of the above [A1], apply an aqueous solution of N-2-(aminoethyl)-3-aminopropyltrimethoxysilane with a concentration of 2% by mass, and dry it at 100°C. Form an organic anti-rust treatment layer.

[Processing for the face corresponding to face (B)] Next, [B1] roughening treatment and [B2] anti-rust treatment were sequentially applied to the non-roller surface of the electrolytic copper foil produced in Production Example 1 under the following conditions, as the surface opposite to the above-mentioned surface (A) ( B).

[B1] Roughening treatment The roughening treatment is a two-stage plating treatment of roughening plating treatment and fixed plating treatment on the surface (B) of the copper foil base in a roll-to-roll manner to form a roughened treatment layer. The roughening plating treatment and the fixing plating treatment are performed under the following conditions.・Roughening plating treatment uses the following copper sulfate aqueous solution and performs plating treatment under the following conditions. ＜Electrolytic solution composition＞ Copper sulfate pentahydrate: converted to copper (atom), 60g/L Sulfuric acid: 100g/L ＜Electrolysis conditions＞ The current density, treatment time, and charge density are as shown in Table 1. Other conditions are as follows. Liquid temperature: 30°C Processing speed: 11m/min・For fixed plating treatment, use the following copper sulfate aqueous solution and perform plating treatment under the following conditions. ＜Electrolyte composition＞ Copper sulfate pentahydrate: converted from copper (atom), 100g/L Sulfuric acid: 150g/L ＜Electrolysis conditions＞ Liquid temperature: 50℃ Current density: 5A/dm ² Processing time: 10 seconds Charge density: 50C /dm ² processing speed: 11m/min

[B2] Anti-rust treatment: As for the surface (B) after the roughening treatment of the above [B1], metal anti-rust treatment and organic anti-rust treatment are sequentially applied under the following conditions as anti-rust treatment.・Metal anti-rust treatment: Apply metal plating in the order of Ni, Zn, and Cr under the following conditions to the surface (B) after the roughening process of [B1] above to form a metal anti-rust treatment layer. <Ni plating conditions> Ni: 40g/L H ₃ BO ₃ : 5g/L Liquid temperature: 20°C pH: 3.6 Current density: 0.2A/dm ² Processing time: 10 seconds <Zn plating conditions> Zn: 2.5g/L NaOH : 40g/L Liquid temperature: 20℃ Current density: 0.3A/dm ^2Processing time: 5 seconds <Cr plating conditions> Cr: 5g/L Liquid temperature: 30℃ pH: 2.2 Current density: 5A/dm ^2Processing time: 5 seconds・Organic anti-rust treatment On the metal anti-rust treatment layer (especially the surface Cr plating layer) formed above, apply an aqueous solution of 3-glycidoxypropyltrimethoxysilane with a concentration of 0.2% by mass, and Dry it at 100°C to form an organic anti-rust treatment layer.

(Example 2) In Example 2, surface-treated copper foil was obtained by the same method as Example 1 except that the [B1] roughening treatment was not performed on the surface (B). Under the conditions described in Table 1, a surface-treated copper foil was obtained.

(Example 3) In Example 3, the non-cylindrical surface of the electrolytic copper foil produced in Example 1 of Production of the Copper Foil Base was used as the surface (A) and the cylinder surface was used as the surface (B), under the conditions described in Table 1. , the surface-treated copper foil was obtained in the same method as Example 1.

(Example 4) Example 4 is for surface (A). Under the following conditions, metal anti-rust treatment and organic anti-rust treatment are sequentially performed as [A2] anti-rust treatment. For surface (B), [B1] roughening treatment is not performed. , Except for this, under the conditions described in Table 1, a surface-treated copper foil was obtained in the same manner as in Example 3. ・Metal anti-rust treatment On the surface (A) after the planarization process of the above [A1], metal plating is applied in the order of Zn and Cr under the following conditions to form a metal anti-rust treatment layer. ＜Zn plating conditions＞ Except for the current density, the Zn plating conditions are the same as the above [B2] anti-rust treatment. It is worth noting that the current density is the condition recorded in Table 1. ＜Cr plating conditions＞ Except for the current density, the Cr plating conditions are the same as those for the above [B2] anti-rust treatment. It is worth noting that the current density is the condition recorded in Table 1.

＜Organic anti-rust treatment＞ On the metal anti-rust treatment layer (especially the surface Cr plating layer) formed above, an N-2-(aminoethyl)-3-aminopropyltrimethoxysilane aqueous solution with a concentration of 2% by mass was applied. Dry it at 100°C to form an organic anti-rust treatment layer.

(Examples 5 to 13) Examples 5 to 13 are for surface (A). Only metal anti-rust treatment is performed under the following conditions as [A2] anti-rust treatment. In addition, under the conditions described in Table 1, the same treatment as in Example 1 is performed. The same method is used to obtain surface treated copper foil. ・Metal anti-rust treatment On the surface (A) after the planarization treatment of the above [A1], Zn and/or Cr electroplating is applied under the following conditions to form a metal anti-rust treatment layer. ＜Zn plating conditions＞ Except for the current density, the Zn plating conditions are the same as the above [B2] anti-rust treatment. It is worth noting that the current density is the condition recorded in Table 1. ＜Cr plating conditions＞ Except for the current density, the Cr plating conditions are the same as those for the above [B2] anti-rust treatment. It is worth noting that the current density is the condition recorded in Table 1.

(Example 14) In Example 14, the rolled copper foil produced in Production Example 2 was used as the copper foil base, and one side of the rolled copper foil was designated as surface (A) and the other side was designated as surface (B). Except that, under the conditions described in Table 1, a surface-treated copper foil was obtained in the same method as Example 8.

(Comparative example 1) In Comparative Example 1, the electrolytic copper foil produced in Comparative Production Example 1 was used as a copper foil base, and the non-cylinder surface of the electrolytic copper foil was referred to as surface (A), and the cylinder surface was referred to as surface (B). Regarding surface (A), The surface treatment was obtained in the same manner as in Example 8 under the conditions described in Table 1 except that [A1] planarization was not performed and surface (B) was not subjected to [B1] roughening. copper foil.

(Comparative Example 2) In Comparative Example 2, the electrolytic copper foil produced in Production Example 1 was used as a copper foil base, and the non-cylindrical surface of the electrolytic copper foil was referred to as surface (A), and the cylinder surface was referred to as surface (B). (A), without [A1] planarization treatment, electrolytic polishing is performed under the following conditions. For surface (B), without [B1] roughening treatment, under the conditions described in Table 1, A surface-treated copper foil was obtained in the same manner as in Example 8.・Electrolytic polishing was performed on the surface (A) of the copper foil base using a phosphoric acid-sulfuric acid aqueous solution having the following electrolyte composition and under the following conditions. <Composition of phosphoric acid-sulfuric acid aqueous solution> Phosphoric acid: 67 mass% Sulfuric acid: 10 mass% Water: 23 mass% <Electrolytic polishing conditions> Constant voltage: 10V/cm ² Processing time: 60 seconds

(Comparative example 3) Comparative Example 3 is for surface (A). In the above-mentioned [A1] planarization treatment, a copper pyrophosphate aqueous solution having the following electrolyte composition is used. For surface (B), [B1] roughening treatment is not performed, except that Except for this, a surface-treated copper foil was obtained in the same manner as in Example 8 under the conditions described in Table 1. ＜Electrolyte composition (copper pyrophosphate aqueous solution)＞ Copper pyrophosphate trihydrate: 80g/L Potassium pyrophosphate: 300g/L Ammonia: 0.25g/L

(Comparative Examples 4 and 5) In Comparative Examples 4 and 5, under the conditions described in Table 1, surface-treated copper foils were obtained in the same method as Example 1.

(Comparative example 6) In Comparative Example 6, under the conditions described in Table 1, a surface-treated copper foil was obtained in the same method as Example 8.

[Table 1]

(evaluation) The following characteristic evaluation was performed on the surface-treated copper foils of the above-mentioned Examples and Comparative Examples. The evaluation conditions for each characteristic are as follows. Unless otherwise specified, each measurement is performed at room temperature (25°C ± 2°C). The results are shown in Table 2.

[Specular gloss] For the surface (A) and surface (B) of the surface-treated copper foil, use a gloss meter (VG7000 manufactured by Nippon Denshoku Industries Co., Ltd.) based on JIS Z 8741: 1997 to measure 75 of the TD. 75 degree mirror gloss Gs (75°) and MD 75 degree mirror gloss Gs (75°). It is worth noting that the measurement was performed five times each in the longitudinal direction (conveyance direction, MD) and the orthogonal direction (TD) to the longitudinal direction of the surface-treated copper foil at a light receiving angle of 75°. The measured values (N=5) were averaged for each direction, and each average value was used as each 75-degree specular gloss Gs (75°). In addition, from the 75-degree specular gloss Gs (75°), _{the specular} gloss ratio R ( 75°) [Gs _MD (75°)/Gs _TD (75°)]. In addition, in the same manner as in the case of the 75-degree specular gloss Gs (75°) described above, the 60-degree specular gloss Gs (60°) was measured in each direction on the surface (A) of the surface-treated copper foil, and the MD was calculated. The 60-degree specular gloss Gs _MD (60°) relative to the TD The 60-degree specular gloss Gs _TD (60°) specular gloss ratio R (60°) [Gs _MD (60°)/Gs _TD (60°) )].

[Developed area ratio (Sdr)] The developed area ratio (Sdr) of the surfaces (A) and (B) of the surface-treated copper foil was measured using a confocal laser microscope (VK-X1050 and VK-X1000 manufactured by Keynes Co., Ltd.) in accordance with ISO25178. The measurement is performed at any five points, the measured values (N=5) are averaged, and the average value is used as the developed area ratio (Sdr) of each surface. It is worth noting that the objective magnification of the confocal laser microscope is 100 times, the scanning mode is laser confocal, the measurement size is 2048×1536, the measurement quality is high precision, and the pitch is 0.08 μm. In addition, the calculation of Sdr is performed based on the filter processing and calculation conditions shown below. Image processing: smoothing (3×3, median) S filter: none F-operation: plane tilt correction L filter: 0.025μm (Gaussian) Calculation target area: 100μm×100μm

[Zn, Cr, and Si adhesion amount] For the surface (A) of the surface-treated copper foil, a scanning fluorescence X-ray analysis device (manufactured by Rigaku Co., Ltd., ZSX Primus IV) was used to analyze by fluorescence X-ray analysis, and Zn, Cr, and Si adhesion amount. It is worth noting that the number of each atom is quantified using a calibration curve obtained from a known standard sample.

[Evaluation of discoloration of surface (A)] The following discoloration experiment was performed and evaluated based on the following evaluation standards as an evaluation of discoloration of surface (A). (Discoloration Test) The discoloration test was performed under the following conditions using a copper foil roll wound with the surface (A) of the surface-treated copper foil as the outer side and with the surface (A) and the surface (B) in contact. (1) Normal storage: Store the above copper foil roll in a dryer maintained at a temperature of 20°C ± 2°C and a humidity below 3% RH. Cut the copper foil into 1m-sized pieces for 1 month, 3 months, and 12 months. 3 tablets of ² were obtained to obtain a sample for evaluation. (2) High-humidity storage: Store the above copper foil roll in a constant temperature and humidity chamber maintained at a temperature of 20°C ± 2°C and a humidity of 50% RH ± 5% RH. For 1 month, 3 months, and 12 months, The copper foil was cut into three pieces with a size of 1 ^m2 , and samples for evaluation were obtained.

(Observation) For each evaluation sample obtained above, the presence or absence of discoloration on the surface (A) was evaluated under the following conditions. <1> First, for all three evaluation samples obtained above, the surface (A) was observed in its original state to confirm whether or not the surface (A) was discolored. Here, if discoloration is confirmed in at least one of the three evaluation samples, the evaluation will be "C (impossible)". <2> In the above <1>, for the surface-treated copper foil in which discoloration was not confirmed in any of the three evaluation samples, the following experiment was further performed, and the surface characteristics of the surface (A) were further evaluated as (S to B). <2-1> First, the evaluation sample (1 m ² ) obtained above was cut into 0.3 m ² in size, and five test pieces were cut out. Next, the five test pieces were kept in a highly accelerated life test device (EHS-222 (M) manufactured by Espec Co., Ltd.) through moisture saturation control, and maintained for 24 hours in an environment with a temperature of 110°C ± 2°C and a humidity of 100% RH. hours. Thereafter, all five test pieces were observed and the surface (A) was observed to confirm whether there was any discoloration. Here, if discoloration is confirmed in at least one of the five test pieces, the evaluation is "B (acceptable)". If discoloration is not confirmed in any of the five test pieces, the following <2-2> evaluation will be performed. <2-2> Cut the evaluation sample (1m ² ) obtained above into 0.3m ² in size, and cut out 5 test pieces. Next, the five test pieces were kept in a highly accelerated life test device (same as above) for 96 hours under moisture saturation control at a temperature of 110°C ± 2°C and a humidity of 100% RH. Thereafter, all five test pieces were observed and the surface (A) was observed to confirm whether there was any discoloration. Here, those in which discoloration was confirmed in at least one of the five test pieces were evaluated as "A (good)", and those in which discoloration was not confirmed in any of the five test pieces were evaluated as "S (excellent)". (Evaluation criteria) S (Excellent): There is no discoloration in any of the above ＜1＞, ＜2-1＞, and ＜2-2＞ A (Good): There is no discoloration in any of the above ＜1＞ and ＜2-1＞, ＜2-2 ＞Discoloration B (possible): No discoloration in the above ＜1＞, discoloration in the above ＜2-1＞ C (not possible): discoloration in the above ＜1＞

(comprehensive evaluation) In addition, the above-mentioned evaluation results were compiled and the discoloration-inhibiting effect was comprehensively evaluated based on the following standards. ＜Qualified＞ S: All ratings are S A+: The evaluation of high-humidity storage for 12 months is A, and other evaluations are S. A: The evaluations for normal storage for 12 months and high humidity storage for 12 months are all A, and other evaluations are A or S. B++: Evaluation of high-humidity storage for 12 months is B, other evaluations are A or S (there is at least 1 S) B+: The evaluation of high-humidity storage for 12 months is B, and other evaluations are A. B: The evaluation of high-humidity storage for more than 3 months is B, and other evaluations are A or S. C+: Evaluations of normal storage for 12 months and high-humidity storage of more than 3 months are all B, other evaluations are A or S C: Evaluations of normal storage for more than 3 months and high-humidity storage of more than 3 months are all B, and other evaluations are A or S. ＜Unqualified＞ D: There is an evaluation of C

[Evaluation of transfer characteristics] The transmission loss in the high frequency band is measured as an evaluation of the transmission characteristics. Details are as follows. A polyphenylene ether-based low dielectric constant resin base material (MEGTRON 7, manufactured by Panasonic Co., Ltd., thickness 60 μm) was bonded to a surface-treated copper foil to produce a substrate for transmission characteristic measurement. The substrate is designed to be constructed in a stripline configuration with a conductor length of 400mm, a conductor thickness of 18μm, a conductor width of 0.14mm, an overall thickness of 0.39mm, and a characteristic impedance of 50Ω. In addition, the surface-treated copper foil and the resin base material are bonded by overlapping the copper foil so that the surface (B) of the surface-treated copper foil faces the resin base material, and pressing it for 2 hours under the conditions of surface pressure 3.5MPa and 200°C. , implemented accordingly. For the substrate used for measuring the above transfer characteristics, the transmission loss at 40 GHz was measured using a vector network analyzer E8364C (KEYSIGHT TECHNOLOGIES) and calculated in dB/m units from the conductor length. The smaller the absolute value of the measured value of the transmission loss is, the smaller the transmission loss is, which means that the transmission characteristics are good. Using the obtained measured values as indicators, the transfer characteristics were evaluated based on the following evaluation criteria. S: The absolute value of transmission loss at 40GHz does not reach 44.0dB A: The absolute value of transmission loss at 40GHz is 44.0dB or more and 50.0dB or less B: The absolute value of the transmission loss at 40GHz exceeds 50.0dB

[Table 2]

As shown in Table 2, it was confirmed that the surface (A) satisfies the specular gloss ratio R (75°) [Gs _MD (75°)/Gs _TD (75°)] of 0.90 or more and 1.60 or less (requirement (I) )) and the developed area ratio (Sdr) is 3.00% or less (requirement (II)), even if it is stored as a copper foil roll for a long time, surface discoloration can be effectively suppressed regardless of the humidity of the storage environment (Example 1～14).

On the other hand, it was confirmed that surface-treated copper foil that does not meet at least one of the above requirements (I) and (II) will discolor after 12 months of normal storage and 3 months of high-humidity storage. Discoloration (Comparative Examples 1 to 6).

Furthermore, it was confirmed that when the surface-treated copper foil of the present invention is used for printed circuit boards, a printed circuit board excellent in transmission characteristics can be obtained. In particular, it was confirmed that when a surface-treated copper foil with a development area ratio (Sdr) of surface (B) of 120% or less is used, the transmission characteristics can be further improved (Examples 1 to 4, 6, 9, and 12 ).

1:Cathode 2: Insoluble anode 3: Copper sulfate electrolyte 4: Non-roller surface (M surface) 5:Roller surface (S surface) 6:Electrolytic copper foil

Figure 1 is a schematic diagram of an electrolytic copper foil manufacturing device.

1:Cathode

2: Insoluble anode

3: Copper sulfate electrolyte

4: Non-roller surface (M surface)

5:Roller surface (S surface)

6:Electrolytic copper foil

Claims (13)

A surface-treated copper foil having one side (A) and the other side (B); the aforementioned side (A) satisfies the following requirements (I) and (II): ・Requirement (I): in the aforementioned The surface of the surface treated copper foil is the specular gloss ratio R of the 75-degree specular gloss Gs _MD (75°) of MD to the 75-degree specular gloss Gs _TD (75°) of TD measured in accordance with JIS Z 8741:1997 (75°) [Gs _MD (75°)/Gs _TD (75°)] is 0.90 or more and 1.60 or less; ・Requirement (II): The developed area of the surface of the aforementioned surface-treated copper foil measured by a laser microscope Ratio (Sdr) is 3.00% or less. Surface-treated copper foil as described in claim 1, wherein: the aforementioned surface (B) further satisfies the following requirements (III) and (IV): ・Requirement (III): On the surface of the aforementioned surface-treated copper foil, in accordance with JIS Z 8741: Specular gloss ratio R (75°) of the 75-degree specular gloss Gs _MD (75°) of MD measured in 1997 relative to the 75-degree specular gloss Gs _TD (75°) of TD [Gs _MD (75°) )/Gs _TD (75°)] is 0.60 or more and 1.50 or less; ・Requirement (IV): The developed area ratio (Sdr) measured by a laser microscope on the surface of the aforementioned surface-treated copper foil is 300% or less. The surface-treated copper foil as described in claim 1 or 2, wherein: in the aforementioned requirement (I), the aforementioned specular gloss ratio R (75°) [Gs _MD (75°)/Gs _TD (75°)] is Above 0.95 and below 1.50. The surface-treated copper foil according to any one of claims 1 to 3, wherein: on the surface (A), the Zn adhesion amount is 0.001 mg/dm ² or more and 0.800 mg/dm ² or less, or the Cr adhesion amount is It is 0.001 mg/dm ² or more and 0.500 mg/dm ² or less. The surface-treated copper foil according to any one of claims 1 to 4, wherein the Si adhesion amount on the surface (A) is 0.001 mg/dm ² or more and 0.500 mg/dm ² or less. The surface-treated copper foil according to any one of claims 2 to 5, wherein in the requirement (IV), the developed area ratio (Sdr) is 120% or less. The surface-treated copper foil according to Claim 6, wherein in the aforementioned requirement (IV), the aforementioned developed area ratio (Sdr) is 3.00% or less. The surface-treated copper foil according to any one of claims 1 to 7, which is an electrolytic copper foil. The surface-treated copper foil according to claim 8, wherein the surface (A) is a surface derived from the surface of the rotating drum-shaped cathode peeled off. A copper foil roll made of the surface-treated copper foil as described in any one of claims 1 to 9; The film is wound with the surface (A) as the outer side and the surface (A) and the surface (B) in contact with each other. A copper laminated board including the surface-treated copper foil according to any one of claims 1 to 9. The copper laminated board as described in claim 11, wherein: the aforementioned surface (B) is the surface bonded to the resin substrate. A printed circuit board including the surface-treated copper foil according to any one of claims 1 to 9.

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