JP2011162860A - Surface-roughened copper foil, method of producing the same and copper-clad laminate plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface-roughened copper foil excellent in etching workability, high heat-resistant adhesion property and high-frequency transmittance characteristic without migration failure, and to provide a circuit substrate which is obtained by laminating a heat-resistant copper foil excellent in the high-frequency transmittance characteristic onto a flexible resin substrate or a rigid resin substrate and is excellent in etching workability, high heat-resistant adhesion property and high-frequency transmittance characteristic without migration failure. <P>SOLUTION: The surface roughened copper foil is provided with a primary roughened surface formed by subjecting at least one side surface of an untreated copper foil to an electrolytic roughening treatment by a pulse cathode using metal copper, a secondary treatment surface formed by subjecting the primary roughened surface to a flat plating treatment using metal copper, a tertiary treatment surface formed by subjecting the secondary roughened surface to a treatment using metal nickel and a quaternary treatment surface formed by subjecting the tertiary treatment surface to a treatment using metal zinc, in this order. A rust-preventive layer and a protective layer are disposed on the quaternary treatment surface as necessary. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to a surface-treated copper foil excellent in high-frequency transmission characteristics and heat resistance indispensable for recent communication terminal functions, and a method for producing the same.
Furthermore, the present invention relates to a rigid and a copper-clad laminate for flexible electronic circuit boards, which are indispensable for a communication terminal function using the surface-treated copper foil and have excellent long-term reliability.

  As represented by mobile phones, in addition to miniaturization and thinning of communication terminal equipment, in addition to communication, video and video transmission and reception, as well as GPS (Global Positioning System) functions, one-segment reception, and other multi-functionality have advanced significantly. It is out. Such a technology is not limited to electronic devices, and has recently been installed in hybrid cars and electric cars to dramatically improve convenience. Therefore, attention is paid to the copper clad laminated board used for such a communication terminal device.

  Recently, as the communication terminal device, an inter-vehicle radar that detects a distance from an object by transmitting a high-frequency radio wave from a driving car and a night-vision radar that detects an object in the dark have been developed. Supports driving.

  A high-frequency-compatible PCB (Printed Circuit Board) capable of covering several giga bands to several tens of giga bands, package parts mounted, and the like play an important key in communication technologies such as radar. A combination of a high-frequency compatible copper foil that is a basis for circuit formation, a resin substrate that is excellent in dielectric characteristics, and a technique related to adhesion between the two has become indispensable for this high-frequency compatible control board.

For example, a fuel injection control component having an electronic control function mounted on a gasoline engine vehicle or a hybrid vehicle is used under severe conditions. In particular, an arithmetic circuit that controls the injection amount of a mixed gas in an internal combustion engine and a computer box that controls the number of revolutions of a motor require a quick arithmetic performance. The more the computation is performed, the more the circuit generates heat. Even if heat dissipation processing is performed, the inside of the box inevitably becomes a high temperature, and the circuit board thermally expands in a three-dimensional direction.
Conventionally, a copper-clad laminate is used for an arithmetic circuit in a computer box, and a heat dissipation method in which a heat-dissipating aluminum plate is bonded is generally adopted as a countermeasure against slow heat. However, due to the increase in the number of computations due to the recent increase in functionality, there is an urgent need to significantly improve the heat dissipation effect, and automobile manufacturers, electronic control mounting component manufacturers, and related PCB manufacturers, are concerned with the use of laminated circuit boards. There is an urgent need to review it.

However, when copper foil is used for the circuit board, the thermal expansion coefficient of the resin constituting the resin board and the thermal expansion coefficient of the copper foil need to be theoretically the same. The thermal expansion coefficient of the substrate is brought close to the thermal expansion coefficient of the copper foil. However, they cannot be made substantially the same.
Therefore, in these industries, copper foil has a heat-resistant follow-up property corresponding to the thermal expansion of the resin material, and even when this follow-up limit is exceeded, it has a stretch property that strongly adheres to the resin substrate and does not cause circuit peeling or disconnection. There is a growing demand for rigid or flexible copper foil laminates made of copper foil having such stretch characteristics.

  In recent years, the use of flexible printed wiring boards using copper foil has expanded, and as a resin substrate material, for example, PET (polyethylene terephthalate) film, PI (polyimide) film, and PC (polycarbonate) film, which are representative of industrial plastic films. Is adopted. And while the method of adhering these resin substrates and copper foils through a binder is used, the casting method technique of applying a thermosetting resin directly to one surface of the copper foil is also used. .

When the resin substrate and copper foil are bonded by a method using a binder, a copper foil having roughened particles is not required to use the binder for bonding, and a rolled copper foil having high gloss or extremely glossy A certain electrolytic copper foil can be mainly used. However, circuit boards laminated by this method are limited to mobile phones, portable electronic terminal devices, digital media recording media, etc. whose usage is limited to the category of daily life, A circuit that is energized from a low current to 40 to 50 A (amperes) cannot be used in terms of long-term quality reliability.
Therefore, for example, as represented by a control circuit board of an automobile, a laminated board of a device having an electronic control function adopted for communication and control operates a circuit soundly under temperature change conditions in a high temperature region. It is necessary to follow the thermal expansion of the resin substrate and the resin substrate that does not cause “warping” or “crack” in the copper-clad laminate, and does not cause circuit peeling between the resin substrate (adhesion) Yes) Copper foil is required.

JP 2008-127618 A Japanese Patent Laid-Open No. 10-168596

  Copper foils with added value such as high-frequency characteristics include etching process necessary for circuit formation, resin substrate with excellent heat resistance, heat resistance and adhesion during thermocompression lamination, and high transmission characteristics combined with resin substrate It is required to have both. However, in general, it is physically very difficult to achieve both improved adhesion strength and excellent transmission characteristics.

The adhesion between the copper foil and the resin substrate is largely due to the physical anchoring effect on the resin substrate due to the unevenness provided on the surface of the copper foil. (1) A roughening treatment with copper particles is performed, and the treatment surface is subjected to a metal plating treatment for improving heat resistance and a coupling agent treatment for improving the chemical binder effect and adhesion as necessary.
On the other hand, in order to improve the high-frequency transmission characteristics, generally, electrical transmission flows mainly through the surface layer of the conductor, so that the surface of the copper foil, which is a circuit material, needs to have smoothness similar to a mirror surface.

  Conventionally, from such a technical background, copper roughened particles are applied to the laminated surface side of the copper foil resin by electroplating so as to reduce the roughness, and heat resistance (adhesion) is provided. In order to maintain this, smooth metal plating is applied to heavy metals other than copper, and the lack of adhesion due to the anchoring effect is cleared by the combined use of a silane coupling agent. However, such a technique cannot provide a copper foil excellent in etching processability, high heat-resistant adhesion, and transmission characteristics free from migration defects.

  An object of the present invention is to provide a copper foil that satisfies such requirements and has excellent etching processability, high heat-resistant adhesion, and high frequency transmission characteristics free from migration defects, and has smoothness (high frequency characteristics) and anchoring effect (resin). As a result of intensive studies to satisfy the contradictory properties of the adhesion to the substrate), one of the copper foils is preferably one of the copper foils made of OFC (oxygen-free copper) if it is a rolled copper foil. If it is an electrolytic copper foil, surface treatment is preferably performed on the electrolyte surface (mat surface) side to provide a copper foil excellent in etching processability, high heat-resistant adhesion, and transmission characteristics free from migration defects.

  The surface-roughened copper foil of the present invention has a primary roughened surface that has been subjected to pulse cathodic electrolysis roughening treatment with metallic copper and at least one surface of the untreated copper foil, and has been subjected to smooth plating treatment with metallic copper. A secondary treatment surface, a tertiary treatment surface treated with metallic nickel, and a quaternary treatment surface treated with metallic zinc are provided in this order.

  The surface-roughened copper foil of the present invention is provided with a rust preventive layer made of a rust preventive agent on the quaternary treated surface of the metal zinc.

  The surface-roughened copper foil of the present invention is provided with a rust-preventing layer with a rust-preventing agent on the quaternary treatment surface with the metallic zinc, and a protective layer with a coupling agent is provided on the rust-preventing layer. .

The untreated copper foil is an electrolytic copper foil or a rolled copper foil, and the substrate on the side of the copper foil subjected to the primary roughening treatment has an Rz value specified in JIS-B-0601 of 0.8 to The thickness is preferably 2.5 μm.
Moreover, it is desirable that the elongation percentage of the untreated copper foil at room temperature is 3.5% or more.

  Furthermore, it is preferable that the roughness after the secondary treatment is 3.0 μm or less in terms of the Rz value defined in JIS-B-0601.

  In the method for producing a surface-roughened copper foil of the present invention, at least one surface of an untreated copper foil is subjected to primary roughening made of metallic copper by pulse cathodic electrolysis roughening, and the surface is subjected to the primary roughening treatment. A secondary treatment made of metallic copper is performed by a smooth plating treatment, a tertiary treatment is carried out by treatment of metallic nickel on the secondary roughened surface, and a quaternary treatment surface by treatment of metallic zinc is applied on the tertiary treatment surface. It is a manufacturing method characterized by giving.

  In the method for producing a surface roughened copper foil of the present invention, the surface on the side subjected to the roughening treatment is subjected to pulse cathodic electrolysis on a copper foil surface having an Rz value specified by JIS-B-0601 of 0.8 to 2.5 μm. The surface is roughened according to JIS-B-0601 by subjecting it to primary roughening made of metallic copper by roughening treatment, and applying secondary treatment made of metallic copper by smooth plating treatment on the surface subjected to the primary roughening treatment. The Rz value is 3.0 μm or less, and the secondary roughened surface is subjected to a tertiary treatment by treatment with metallic nickel, and the tertiary treatment surface is subjected to a fourth treatment surface by treatment with metallic zinc. It is a manufacturing method characterized by this.

  In the method for producing a surface-roughened copper foil of the present invention, at least one surface of an untreated copper foil is subjected to primary roughening made of metallic copper by pulse cathodic electrolysis roughening, and the surface is subjected to the primary roughening treatment. A secondary treatment made of metallic copper is performed by a smooth plating treatment, a tertiary treatment is carried out by treatment of metallic nickel on the secondary roughened surface, and a quaternary treatment surface by treatment of metallic zinc is applied on the tertiary treatment surface. Followed by heat treatment to alloy the metallic copper, the metallic nickel, and the metallic zinc.

  In the method for producing a surface-roughened copper foil of the present invention, at least one surface of an untreated copper foil is subjected to primary roughening made of metallic copper by pulse cathodic electrolysis roughening, and the surface is subjected to the primary roughening treatment. A secondary treatment made of metallic copper is performed by a smooth plating treatment, a tertiary treatment is carried out by treatment of metallic nickel on the secondary roughened surface, and a quaternary treatment surface by treatment of metallic zinc is applied on the tertiary treatment surface. And applying a rust preventive layer with a rust inhibitor on the quaternary treatment surface, and then heat treating to alloy the metal copper, the metal nickel, and the metal zinc. .

  In the method for producing a surface-roughened copper foil of the present invention, at least one surface of an untreated copper foil is subjected to primary roughening made of metallic copper by pulse cathodic electrolysis roughening, and the surface is subjected to the primary roughening treatment. A secondary treatment made of metallic copper is performed by a smooth plating treatment, a tertiary treatment is carried out by treatment of metallic nickel on the secondary roughened surface, and a quaternary treatment surface by treatment of metallic zinc is applied on the tertiary treatment surface. And a protective layer composed of a rust preventive agent and a coupling agent is provided on the quaternary treatment surface.

  In the method for producing a surface-roughened copper foil of the present invention, at least one surface of an untreated copper foil is subjected to primary roughening made of metallic copper by pulse cathodic electrolysis roughening, and the surface is subjected to the primary roughening treatment. A secondary treatment made of metallic copper is performed by a smooth plating treatment, a tertiary treatment is carried out by treatment of metallic nickel on the secondary roughened surface, and a quaternary treatment surface by treatment of metallic zinc is applied on the tertiary treatment surface. A rust preventive layer with a rust preventive agent and a protective layer made of a coupling agent are applied on the quaternary treatment surface, followed by heat treatment to alloy the metal copper, the metal nickel, and the metal zinc. The manufacturing method characterized by this.

  It is preferable that the untreated copper foil used in the method for producing the surface-roughened copper foil has an elongation percentage of 3.5% or more in a normal temperature state of the copper foil.

  The copper clad laminate of the present invention is obtained by laminating the surface roughened copper foil or the surface roughened copper foil produced by the production method on a resin substrate.

The surface-treated copper foil of the present invention comprises a primary roughened surface obtained by subjecting the surface of an untreated copper foil to copper fine roughening by pulse cathodic electrolysis, and then roughened particles (copper ) Is treated with smooth copper plating so that it does not fall off, and a nickel / zinc heat-resistant treatment layer is provided on the secondary treatment surface with a tertiary treatment surface with metallic nickel and a fourth treatment surface with metallic zinc. Furthermore, by providing a rust-proofing layer and a protective layer by silane coupling treatment if necessary, a surface-roughened copper foil having excellent high-frequency transmission characteristics free from etching processability, high heat-resistant adhesion, and migration defects is provided. It has an excellent effect.
The roughened shape obtained by the present invention is suitable as a copper foil that can select any of the lamination conditions (pressing method, laminating method, casting method, etc.) when laminating with a resin material.

  The copper-clad laminate of the present invention obtained by laminating the heat-resistant copper foil having excellent high-frequency transmission characteristics with a flexible resin substrate or a rigid resin substrate is excellent in etching processability, high heat-resistant adhesion, and high-frequency transmission characteristics free from migration defects. The circuit board can be produced and has an excellent effect.

It is process explanatory drawing which shows an example of the surface roughening process of this invention.

Hereinafter, the surface-roughened copper foil excellent in the high-frequency transmission characteristics of the present invention and the manufacturing method thereof will be described in detail.
The surface-roughened copper foil having excellent high-frequency transmission characteristics according to the present invention has adhesion to a resin substrate on at least one surface (preferably a matte surface in an electrolytic copper foil) to be bonded to the resin substrate of the copper foil. Further, a primary roughening treatment with copper particles having a high anchoring effect is performed by pulse cathode electrolysis. Next, in order to keep the primary roughened surface healthy, a capsule copper layer made of smooth copper plating is deposited on the primary roughened surface by cathodic electroplating as a secondary roughening treatment. Next, a metallic nickel layer is applied to the secondary roughened surface by electrolytic plating (tertiary treatment), and a metallic zinc layer is provided on the tertiary treated surface by electrolytic plating (quaternary treatment). In addition, it is preferable to add an appropriate vanadium metal or antimony metal to the zinc plating bath in order to improve chemical resistance.

As the untreated copper foil, it is preferable to employ an electrolytic copper foil in which the surface of the mat surface is in the range of 0.8 to 2.5 μm as the Rz value specified in JIS-B-0601. The crystal grains are preferably very fine particles. The fine particles are a state in which the cross section of the electrolytic copper foil on the mat surface side has a fine non-columnar crystal structure with a crystal grain size of 1.0 μm or less.
If it is a rolled copper foil, the foil which rolled the OFC (oxygen-free copper) material of the value prescribed | regulated to IPC-TM-650 in the range of 35-45 kN / cm < ² > (50-65 MPa if Young's modulus) is preferable.

  Also, as a copper foil for use in high-temperature lamination, it is possible to adopt a copper foil having an elongation rate of 3.5% or more at room temperature considering the elongation rate of a heat-resistant resin to be bonded to the copper foil. preferable.

  For example, secondary smooth copper plating is applied to the surface of the copper fine roughening treatment (cog-like copper particles) applied to the one surface of the copper foil by primary roughening. As a result of the secondary smooth plating treatment, the bump-like fine particles maintain a healthy shape and the uniformity of the particles is maintained. The rough surface after the secondary smooth copper plating treatment is preferably in the range of 2.5 to 3.0 [mu] m in Rz value defined in JIS-B-0601.

In the copper foil used for heat resistance and high frequency transmission characteristics of the present invention, a metallic nickel layer and a metallic zinc layer having a heat resistance effect are provided as tertiary and quaternary treatments on the surface after the primary and secondary treatments.
The nickel adhesion amount of the nickel layer by the nickel plating is 0.8 to 1.5 mg / dm ² as metallic nickel, and the zinc adhesion amount of the zinc layer by the zinc plating is 2.5 to 4.5 mg / dm ² as metallic zinc. It is preferable that

Then, if necessary, a rust prevention layer is provided on the surface of the zinc layer. As the rust preventive layer, a chromate rust preventive layer made of chromate is preferable, and the chromium adhesion amount is preferably 0.005 to 0.020 mg / dm ² as metal chromium. This is because if it is within this range, the necessary and sufficient degree of rust prevention can be obtained as the copper foil for the laminated substrate.

It is preferable to provide a protective layer with a coupling agent on the surface of the antirust layer. The protective layer is preferably a chemical protective layer made of a silane coupling agent. The adhesion amount of the silane coupling agent is preferably 0.001 to 0.015 mg / dm ² as silicon. This is because within this range, the adhesiveness with a resin necessary and sufficient as a copper foil for a laminated substrate can be obtained.

  As described above, the surface roughened copper foil of the present invention is provided with a primary roughening treatment layer made of metallic copper as a primary roughening by pulse cathode electrolytic roughening treatment on at least one surface of the untreated copper foil. A secondary treatment layer made of metallic copper is provided as a secondary treatment by smooth plating treatment on the roughening treatment layer, and a tertiary treatment layer made of metallic nickel is provided as a tertiary treatment on the secondary treatment layer. A quaternary treatment layer made of metallic zinc is provided as a quaternary treatment on the treatment layer. The surface-treated copper foil of the present invention exhibits the intended effect sufficiently even with such a configuration, but the surface-treated copper foil produced as described above is then heat treated to produce the metal copper (secondary roughened layer, Alternatively, the primary roughening treatment layer), the metal nickel (tertiary treatment layer), and the metal zinc (quaternary treatment layer) are alloyed.

The metal copper, the metal nickel, and the metal zinc are alloyed by heat treatment and laminated with a flexible resin substrate, a rigid resin substrate or a resin substrate by a casting method, and as a copper-clad laminate substrate, heat-resistant copper foil particularly excellent in high-frequency transmission characteristics As described above, a circuit board free from etching processability, high heat-resistant adhesion, and migration failure can be produced.
The heat treatment may be a post-heat treatment after producing a surface-roughened copper foil, or it can be alloyed with heat at the time of press lamination at the time of heat treatment for laminating with a flexible resin substrate or a rigid resin substrate. The effect is comparable to either.

  The alloying by the heat treatment is performed by providing the quaternary treatment layer, applying a chromate rust prevention layer with a rust inhibitor, for example, chromate on the quaternary treatment layer, and then heat-treating the metal copper, the metal nickel, and the metal. It is also possible to alloy with zinc.

  Further, the alloying by the heat treatment is performed by providing the quaternary treatment layer, applying a rust preventive layer on the quaternary treatment layer, applying a protective layer made of a coupling agent on the rust preventive layer, and then performing a heat treatment. It is also possible to alloy the metal copper, the metal nickel, and the metal zinc.

  When the metal copper, metal nickel, and metal zinc are alloyed, after the quaternary treatment layer is provided, the rust preventive layer is provided, and then the protective layer made of the coupling agent is provided. However, since the effect is almost the same, it can be arbitrarily applied depending on the timing of adhesion to the resin substrate, the manufacturing method of the copper-clad laminate, and the like.

Next, one embodiment of the method for producing the roughened copper foil of the present invention will be described with reference to FIG.
In FIG. 1, an untreated copper foil wound on a reel (electrolytic copper foil or electrolytically degreased rolled copper foil, hereinafter simply referred to as copper foil) A is used to form a roughened copper particle surface by primary pulse cathode electrolysis. One treatment tank 1 is led. The first treatment tank 1 is provided with an iridium oxide anode 11 and is filled with a copper-sulfuric acid electrolyte solution 12, and in the primary treatment tank, from the bump-like fine roughened particles made of copper particles on one side or both sides of the copper foil A. A primary roughening treatment surface is formed. The copper foil B on which the primary roughening treatment surface is formed in the first treatment tank 1 is guided to the second treatment layer 2 after being washed in the water washing tank 15. In the figure, reference numeral 13 denotes a shielding plate.

The second treatment tank 2 is provided with an iridium oxide anode 21 and filled with a copper-sulfuric acid electrolyte solution 22 as in the first treatment tank, and is subjected to a smooth copper plating process. The copper foil C that has been subjected to the smooth plating process is guided to the third treatment layer 3 after being washed in the washing tank 25.
The third treatment tank 3 is provided with an iridium oxide anode 31 and filled with a nickel electrolyte solution 32. The copper foil D plated with nickel in the third treatment tank 3 is washed in the water washing tank 35 and then guided to the fourth treatment tank 4.
The fourth treatment tank 4 is provided with an iridium oxide anode 41 and filled with a zinc electrolyte 42. The copper foil E plated with zinc in the fourth treatment tank 4 is washed in the water washing tank 45 and then guided to the fifth treatment tank 5.

The fifth treatment tank 5 is provided with a SUS anode 51, filled with a chromate electrolyte solution 52, and provided with a chromate rust preventive layer. The copper foil F to which the chromate rust preventive layer has been applied in the fifth treatment tank 5 is washed in the water washing tank 55 and then guided to the sixth treatment tank 6. In the figure, 51 is a SUS anode.
The sixth treatment tank 6 is filled with a silane liquid 62 and a silane coupling agent is applied to the surface of the copper foil F. The copper foil G coated with the silane coupling agent in the sixth treatment tank 6 is wound around the winding roll 8 through the drying step 7.
In the figure, 9 is a power supply contact roll.
If necessary, the surface-treated copper foil wound on the winding roll is heat-treated by a heat treatment apparatus (not shown) to alloy the metallic copper, metallic nickel, and metallic zinc.

  In order to improve the adhesion with the target resin material (resin substrate) as the untreated copper foil A and further improve the transmission characteristics, the roughened surface is low-roughened and excellent in anchoring effect and rough. It is advantageous that the surface layer of the copper halide particles is smooth. For this purpose, it is preferable to use a double-sided glossy electrolytic copper foil having a smooth surface shape rather than an electrolytic copper foil having a crystal structure composed of columnar crystal grains. It is preferable to use an electrolytic copper foil having an Rz value specified in JIS-B-0601 in the range of 0.8 to 2.5 μm and a room temperature elongation at room temperature of 3.5% or more.

The surface-treated copper foil of the present invention is particularly excellent for high-frequency circuit board applications, and is considered to be used with specifications suitable for automotive control circuit boards. For this reason, importance is attached to heat resistance in addition to high-frequency transmission.
On the other hand, as the resin substrate itself to be laminated with the copper foil, a material that hardly expands and contracts with respect to the thermal history, for example, a Teflon (registered trademark) resin material is used. About 3.5% is sufficient for the elongation rate (elongation rate at normal temperature, hereinafter the same) of the copper foil laminated with such a resin substrate that is less elongated due to thermal history. By such a combination of the copper foil and the resin substrate, the substrate does not warp or bend due to the thermal history after the circuit is formed. However, for resin substrates with low elongation due to thermal history, the copper foil should have an elongation of about 3.5%, but when laminated with a resin substrate with a large elongation, it matches the elongation of the resin substrate. Needless to say, it is necessary to make a copper foil having an elongation ratio to be surface-treated or to select a surface treatment from the market.

The primary roughening treatment provided on the mat surface of the copper foil A is performed in the first treatment tank 1 by a pulse cathode electrolytic plating method using a copper sulfate bath to which an arsenic compound or metal molybdenum is added.
In the primary roughening treatment, copper bumpy rough particles are formed on the surface of the copper foil. Specifically, copper sulfate as copper is 20 to 30 g / L, sulfuric acid concentration is H ₂ SO ₄ as 90 to 110 g / L, sodium molybdate as Mo is 0.15 to 0.35 g / L, and chlorine is chloride ion An electrolyte mixed with 0.005 to 0.010 g / L in terms of conversion, the bath temperature is set to 18.5 to 28.5 ° C., and the on-time pulse cathode electroplating current density is set to 28 to 35 A / dm ² . Then, healthy copper bump roughened particles are formed on the surface of the copper foil at an appropriate flow rate and inter-electrode distance. In addition, it is also possible to perform electrolytic plating with smooth copper under the condition that the current density is set to about 15 to 20 A / dm ² as necessary so that the copper bump roughening particles do not fall out in the same bath.

Next, the purpose is to prevent the fine copper roughened particles adhering to the primary roughening treatment from dropping off from the surface of the copper foil, and to adjust the surface shape of each fine copper roughened particle to make the surface area small and uniform. A secondary roughening treatment is performed. The secondary roughening treatment enhances the laminate adhesion with the resin substrate, to avoid an electroless plating defects such as due to migration problems or the residual copper due to residual copper after circuit formation etching, primary roughened layer Is subjected to smooth copper plating by cathodic electroplating.
Specifically, the electrolytic solution in the second treatment tank 2 is set to 35 to 55 g / L using copper sulfate as copper, 90 to 110 g / L using sulfuric acid concentration as H ₂ SO ₄ , and a bath temperature of 35 to 55 ° C. The cathode electrolytic plating current density is set to 15 to 20 A / dm ² , and a smooth copper plating is formed on the surface of the primary fine copper roughened particles at an appropriate flow rate and inter-electrode distance. In this case, the smooth plating treatment thickness is preferably set to a range of 3.0 μm or less in terms of the Rz value defined in JIS-B-0601 with respect to the surface roughness before the treatment. .

The adhesiveness with the resin substrate can be secured by the steps so far. However, if this is the case, the secondary surface roughening with smooth copper plating will adjust the individual surface due to poor adhesion with the resin substrate at high temperatures (assumed temperature is 288 ° C. with lead-free solder reflow process as the maximum temperature). A treatment for improving heat resistance is applied to the treated surface.
In the present invention, a metal nickel layer and a metal zinc layer having appropriate thicknesses are applied to the secondary roughened surface by smooth electrolytic plating. In this process, it has a throwing effect with various resin substrates without impairing the shape of the copper roughened particles formed up to the previous step (secondary roughening treatment step), improving adhesion with the resin substrate and at high temperature A surface treatment is applied to maintain both heat resistance characteristics.

  The bath composition of the nickel electrolytic solution of the third treatment layer for performing electroplating of metallic nickel is not particularly limited as long as it is a soluble nickel compound, but it is preferably 15 to 20 g / L as nickel using nickel sulfate. It is preferable to have a bath composition in which 3.0 to 4.0 g / L of hypophosphorous acid is added as a phosphorus compound to be easily dissolved.

  The bath composition of the zinc bath of the fourth treatment tank for performing electroplating of metallic zinc is not particularly limited as long as it is a soluble zinc compound, but preferably zinc sulfate is used, and zinc is 3.5 to 6.0 g / L. 18 to 40 g / L of sodium hydroxide, 0.1 to 0.5 g / L of vanadium compound as an additive for imparting chemical resistance, or 0.3 to 1.0 g of antimony compound as antimony / L It is preferable to make the bath composition dissolved.

In the above process, the adhesion amount of metallic nickel is preferably 0.8 to 1.5 mg / dm ² as metallic nickel. The adhesion amount of metallic zinc is preferably ^2.5 to 4.5 mg / dm ² as metallic zinc. When a copper foil and a resin substrate are laminated to produce a copper-clad laminate with such an adhesion amount range, the roughened copper particles in the lower layer are sufficient under heating and pressing conditions of about 160 to 240 ° C. The alloy layer of copper, nickel, and zinc is thermally diffused, and this alloy layer does not deform the surface shape of the roughening treatment formed by the primary treatment and the secondary treatment.

  The surface layer that is an alloy layer does not significantly impair the high-frequency conduction characteristics. For example, the conductivity obtained by the method of measuring the electrical resistance value defined in JIS-C-3001 is 0.012 mm thick copper foil in terms of electrical conductivity, so-called surface treatment free (untreated copper foil) after electrolytic foil formation. The measured value in this state is 98.7%, whereas the conductivity in the copper foil obtained by alloying copper, nickel, and zinc, which is obtained by thermally diffusing the copper, nickel, and zinc at 180 ° C., is 97.8 to 98.4%, which hardly affects the high-frequency conduction characteristics.

Next, a chromate rust preventive agent is provided on the surface where nickel and zinc are sequentially treated, if necessary, by dipping treatment or, if necessary, cathodic electrolysis treatment (fifth treatment tank 5) to enhance rust prevention power.
The film thickness in the case of chromate treatment is preferably in the range of 0.005 to 0.025 mg / dm ² as the amount of metallic chromium. Within this adhesion amount range, the surface does not change to copper oxide for up to 24 hours under the condition of a salt spray test (salt water concentration: 5% -NaCl, temperature 35 ° C.) specified in JIS-Z-2371.

  For the formation of the rust preventive layer, organic rust preventives typified by benzotriazole, which are excellent in heat resistance, are commercially available as the derivative compounds, and can be appropriately used. Incidentally, if it is an organic rust preventive, for example, even if it is immersed and dried in a bath constructed at 35-40 ° C. at 5.0 Wt% (weight percent) of product number C-143 of Chiyoda Chemical Co., Ltd. Rust prevention effect comparable to processing is obtained. These rust preventive treatment effects are the same for both rolled copper foil base and electrolytic copper foil base. However, when importance is attached to heat resistance, it is preferable to perform a so-called chromate rust prevention treatment with a chromic acid solution. Also, chromate treatment is superior in cost performance.

Further, the surface subjected to the chromate treatment is appropriately coated with a silane coupling agent as necessary. Adhesion with a Teflon (registered trademark) -based resin substrate or a resin substrate containing a filler, which is often used as a substrate material for high frequency, can be enhanced by the silane coupling agent treatment.
The silane coupling agent is appropriately selected depending on the target resin substrate, and it is particularly preferable to select an epoxy-based, amino-based, or vinyl-based coupling agent that is excellent in compatibility with a high-frequency compatible substrate.
In the present invention, the kind of the product is not limited, but the adhesion amount of the silane coupling agent on the roughened surface side is 0.001 to 0.001 as silicon in order to improve the adhesion to the resin substrate at least chemically. A range of 015 mg / dm ² is preferred.

[Example 1]
An untreated electrolytic copper foil having a thickness of 18 μm, having a Rz value of 0.8 μm as defined in JIS-B-0601 and a normal temperature elongation of 6.2%. Using a copper foil (double-sided glossy electrolytic copper foil manufactured by Furukawa Electric Co., Ltd.), one-side surface roughening treatment was performed on the mat surface side under the following conditions.
In the examples and comparative examples, the cathode electrolysis conditions are described separately as “pulse cathode electrolysis” and “DC cathode electrolysis”.

Primary coarse particle formation bath composition and treatment conditions Copper sulfate ... 23.5 g / L as metallic copper
As sulfuric acid ... 100g / L
Sodium molybdate: 0.25 g / L as molybdenum
Hydrochloric acid: 0.002 g / L as chloride ion
Ferric sulfate: 0.20 g / L as metallic iron
Chromium sulfate: 0.20 g / L as trivalent chromium
Bath temperature: 25.5 ° C
On-time pulse cathode electrolysis on the tank inlet side ... 10ms
Pulse cathode electrolysis off time at tank inlet side ... 60ms
Pulse cathode electrolytic average plating current density: 22.5 A / dm ²

Secondary smooth plating treatment conditions Copper sulfate ... 45g / L as metallic copper
Sulfuric acid ... 110g / L
Bath temperature: 50.5 ° C
DC cathode electroplating current density: 18.5 A / dm ²

Metal nickel plating treatment conditions Nickel sulfate ... 5.0g / L as metal nickel
Persulfate ammonium ········· 40.0 g / L
Boric acid (H ₃ BO ₃ ) 25.0 g / L
Hypophosphorous acid (H ₃ PO ₂ ) ... 3.6 g / L
pH value 3.5
Bath temperature: 20.5 ° C
DC cathode electroplating current density: 12.5 A / dm ²

Metal galvanization treatment conditions Zinc sulfate ···················· 4.0 g / L as metal zinc
Sodium hydroxide ... 25.0g / L
pH: 12.5 to 13.5
Bath temperature: 18.5 ° C
DC cathode electroplating current density: 5.5 A / dm ²
As an anticorrosive treatment for the copper foil to which heat resistance is imparted by nickel plating and galvanizing as described above, an epoxy-based silane coupling agent immersed in a 3 g / L bath as CrO _{3 and} built to 0.5 wt% after drying. (Chiasso Co., Ltd. Sila Ace S-510) was thin-film coated only on the matte surface side of the copper foil.

The surface roughness (matte surface side) of the obtained roughened copper foil subjected to surface treatment was measured by measuring the Rz value defined in JIS-B-0601 and listed in Table 1.
Further, the treated copper foil was cut into a 250 mm square, and the treated surface was superposed on a commercially available polyphenylene ether (PPE) resin-based substrate (Megtron-6 prepreg manufactured by Panasonic Electric Works Co., Ltd.) and heated press lamination (180 to 200 ° C. * 25 Kgf / cm ² * 60 to 120 min) to prepare a single-sided copper-clad laminate for measuring adhesion and evaluating residual copper.

For measurement and evaluation of heat resistance, a processed glass epoxy resin substrate (using LX67N prepreg made by Hitachi Chemical Co., Ltd.) is overlaid with the treated surface (mat surface side) and heated and pressed to laminate a single-sided copper-clad laminate. It produced and it was set as the test piece for heat resistance evaluation.
For the evaluation of the high frequency characteristics, the relative superiority or inferiority was evaluated based on the transmission loss measurement result. The target substrate is a commercially available liquid crystal polymer resin substrate (uses ULTRALAM3000 made by ROGERS CORPORATION) and the processing surface (mat surface side) is overlaid and laminated with a single plate heat press (180-200 ° C), one side A copper clad laminate was prepared and used as a test piece for measuring transmission loss.

The adhesion with the resin base material was measured by the measurement method defined in JIS-C-6481 and listed in Table 1 as the adhesion strength.
Residual copper that affects etching processability and migration failure is ◎ when there is no residual copper per unit area (0.5 mm x 0.5 mm) after etching the surface of the laminated substrate. The results are shown in Table 1, evaluated as ◯, when slightly seen as Δ, and marked as x.

  In addition, the heat quality determination was made by cutting the single-sided copper-clad plate into 50 mm squares, preparing five test pieces under each condition, and PCT (pressure cooker test) test conditions (relative humidity 100%, 2 atm, 121 ° C., 120 minutes), and then the test piece is immersed in a solder bath set at 288 ° C. for 30 seconds to check whether or not “blowing” occurs between the copper foil and the substrate. Was not generated in all of the test pieces, ◎, a case where a slight bulge of less than 5 mmΦ was observed in one piece of the test piece, ○, and 2-3 bulges of less than 5 mmΦ were observed. The case was evaluated as Δ and the case where a bulge of 5 mmΦ or more was seen regardless of the number was evaluated as × and listed in Table 1.

  The transmission measurement is evaluated by a known stripline resonator method (microstrip structure: dielectric thickness: 50 μm, conductor length: 1.0 m, conductor thickness: 12 μm, conductor circuit width: 120 μm, characteristics suitable for measurement in the 1 to 25 GHz range. 1 to 15 GHz using an impedance of 50Ω and no coverlay film (for example, using a coverlay with poor dielectric properties causes transmission loss to increase and the determination of the difference becomes inaccurate). Was continuously measured. Among these measured values, transmission loss (dB / 100 mm) corresponding to frequencies 5, 10, and 15 GHz is expressed as a relative value when the transmission loss value of Comparative Example 5 (GTS-MP-18 μm foil) below is set to 100. 1.

[Example 2]
Using an electrolytic copper foil with an Rz value of 2.5 μm in surface roughness of the untreated copper foil, the same roughness as in Example 1 so that the surface roughness after heat-resistant surface treatment is 3.0 μm or less in Rz value. The same evaluation measurement as in Example 1 was performed. The results are also shown in Table 1.

Example 3
OFC rolled copper foil having a nominal 18 μm, normal temperature elongation of 3.6% and surface roughness Rz value of 0.8 μm instead of the untreated electrolytic copper foil used in Example 1 (Furukawa Electric Co., Ltd.) Except for using (manufacturing), the same roughening and surface treatment as in Example 1 was performed, and the same evaluation measurement as in Example 1 was performed. The results are also shown in Table 1.

Example 4
The same roughening and surface treatment as in Example 1 was performed except that the untreated copper foil used in Example 1 was used and the off-time during pulse cathodic electrolysis under primary roughening conditions was 40 ms. The same evaluation measurement was performed. The results are listed in Table 1.

Example 5
A roughening treatment was performed on both the glossy surface side (drum peeling surface side) and the mat surface side (electrodeposition liquid surface side) of the untreated electrolytic copper foil used in Example 1 by pulse cathode electrolytic treatment. The same roughening treatment and surface treatment were performed, and the same evaluation measurement as in Example 1 was performed. The results are also shown in Table 1. In this case, the roughening treatment is performed separately on both sides by separating the roughening treatment from the tank inlet to the matte surface (electrodeposition liquid surface) on the bottom side and from the bottom to the glossy surface side (drum peeling surface side) from the tank outlet side. Then, at the time of smooth copper plating, DC electrolytic capsule plating was applied to the roughened surfaces on both sides simultaneously from the tank inlet to the bottom side. The reason why the pulse processing is divided into two times is to ensure the effect of setting the ON-OFF time, and the double-sided processing at a limited flow rate in the tank does not supply copper ions when the peak current is reached. This is for avoiding the occurrence of irregularities in the roughening treatment due to insufficient both sides.

[Comparative Example 1]
The mat surface side of the untreated copper foil used in Example 1 is subjected to direct current cathode electrolysis treatment with the same bath composition as in Example 1, and the resulting surface treatment side roughness is 3.0 μm or less in terms of Rz value. The same process as Example 1 was performed except having processed, and the same evaluation measurement as Example 1 was performed. The results are also shown in Table 1.

[Comparative Example 2]
The same evaluation measurement as in Example 1 was performed, except that the untreated copper foil used in Example 2 was treated in the same manner as in Comparative Example 1. The results are also shown in Table 1.

[Comparative Example 3]
The same evaluation measurement as in Example 1 was performed, except that the untreated copper foil used in Example 3 was subjected to the same treatment as in Comparative Example 1. The results are also shown in Table 1.

[Comparative Example 4]
The same evaluation measurement as in Example 1 was performed except that the untreated copper foil used in Example 5 was subjected to a double-sided roughening treatment by direct current electrolytic treatment. The results are also shown in Table 1.

[Comparative Example 5]
The following treatment was applied to the surface of a GTS-MP-18 μm foil (a copper foil having a middle profile-shaped mat surface side classified as an IPC standard by columnar crystals under known electrolytic foil production conditions).

Copper roughening treatment conditions Copper sulfate ... 23.5g / L as metallic copper
As sulfuric acid ... 100g / L
Arsenic compound: 0.150 g / L as arsenic
Hydrochloric acid: 0.002 g / L as chloride ion
Bath temperature: 25.5 ° C
Electrolytic plating current density: 28.5 A / dm ²

Smooth capsule plating conditions for copper Copper sulfate: 52.5 g / L as metallic copper
As sulfuric acid ... 100g / L
Hydrochloric acid ··················· 0.002 g / L
Bath temperature: 45.5 ° C
Electrolytic plating current density: 18.5 A / dm ²

Nickel plating conditions Nickel sulfate: 5.0 g / L as metallic nickel
As persulfate ammonium: 40.0 g / L
As boric acid 28.5g / L
pH: ... 3.5-4.2
Bath temperature: 28.5 ° C

Zinc plating condition Zinc sulfate ............ As metallic zinc 4.8g / L
As sodium hydroxide ... 35.0g / L
pH: 12.5 to 13.8
Bath temperature: 18.5 ° C
Electrolytic plating current density: 0.8 A / dm ²
As an anticorrosive treatment for the nickel and galvanized copper foil, an epoxy-based silane coupling agent (Chisso Corp.) was immersed in a 3 g / L bath as CrO ₃ and then dried to 0.5 wt%. ) Manufactured Sila Ace S-510) was applied as a thin film only to the mat surface side of the copper foil.
The same evaluation measurement as in Example 1 was performed on the surface-treated GTS-MP-18 μm copper foil. The results are also shown in Table 1.

As is clear from Table 1, the copper foils of Examples 1 to 5 have a small transmission loss, the adhesion strength with the resin substrate satisfies the required 0.6 kg / cm or more, and the transmission loss characteristics are rough. It was quite excellent as a modified copper foil.
The solder immersion heat resistance after moisture absorption was evaluated as ◯ because the adhesion strength between Examples 1 and 3 was low, but there was no hindrance to practicality, and the other examples were satisfactory.
Compared with the examples, the general-purpose type copper foil of Comparative Example 5 is satisfactory in adhesion strength and heat resistance, but is very impractical in transmission loss. Comparative Example 1, Comparative Example 2 and Comparative Example 4 are Since there is a high concern about residual copper and it is inferior to the examples from the viewpoint of high-density wiring (etching processability, migration failure) and transmission loss characteristics, it is superior in evaluation of required adhesion to the resin substrate and heat resistance Even if it was, the practicality was evaluated to be inferior to the examples.

  As described above, the copper foil roughened by pulse cathodic electrolysis that is particularly excellent in high-frequency transmission characteristics of the present invention is a combination of Teflon (registered trademark) resin and glass epoxy resin with a high filler content that are difficult to obtain adhesion strength. A control circuit that has excellent adhesion strength (JPCA standard), has appropriate stretch plasticity and heat resistance, has excellent high-frequency characteristics typified by transmission characteristics, and uses high-frequency transmissions for HEV and EV vehicles. Adhesiveness to the resin substrate can be maintained sufficiently, and even under severe natural climate conditions, it has appropriate heat resistance and moisture resistance even when the control circuit itself generates heat, etc. The surface-treated metal has an excellent effect of appropriately exhibiting the characteristics of the high-frequency compatible substrate without impairing the transmission characteristics (so-called transmission loss is small and excellent in transmission characteristics).

The surface roughened copper foil having heat resistance and excellent high-frequency transmission characteristics of the present invention has a very low risk of residual copper in etching, so there is no defect in etching processability, high heat adhesion and transmission characteristics without migration defects. It is possible to provide a circuit board suitable as, for example, an automobile control circuit board that is excellent as an excellent circuit material and requires heat resistance.
Moreover, although the surface treatment similar to an Example was performed and evaluated also about the double-side roughening copper foil of this invention, the result similar to the thing of a single-sided process is obtained.

  According to the method for producing a surface-roughened copper foil having excellent high-frequency transmission characteristics according to the present invention, adhesion strength with a Teflon (registered trademark) resin or a glass epoxy resin with a high filler content, which is difficult to obtain adhesion strength. (JPCA standard), special copper foil that forms a control circuit that has appropriate stretch plasticity and heat resistance, has excellent high-frequency characteristics such as transmission characteristics, and requires heat resistance including automotive applications Can be easily manufactured without the need for a simple device.

According to the method for producing a copper-clad laminate of the present invention, it adheres to a Teflon (registered trademark) resin or a glass epoxy resin with a high filler content, which is difficult to obtain adhesion strength, and has excellent high frequency characteristics typified by transmission characteristics. It is possible to provide a copper-clad laminate that exhibits excellent effects as a copper-clad laminate for forming a control circuit that frequently uses transmission for high-frequency applications for HEV and EV automobiles that require heat resistance.
In addition, according to the method for producing copper foil of the present invention, from the first roughening treatment to the quaternary treatment can be produced in a continuous and consistent process, the surface-treated copper foil can be produced at low cost, and the environment to come Even if the spread of EV cars is promoted from the viewpoint of response, it is possible to sufficiently respond in terms of supply and characteristics.

DESCRIPTION OF SYMBOLS 1 1st roughening process (pulse cathode electrolytic roughening process) tank 2 2nd roughening process (smooth plating process) tank 3 3rd process (metallic nickel process) tank 4 4th process (metallic zinc process) tank A Untreated Copper foil B Primary treated copper foil C Secondary treated copper foil D Tertiary roughened next treated copper foil E Fourth treated copper foil G Surface roughened copper foil

Claims (17)

  At least one surface of the untreated copper foil is subjected to pulse cathodic electrolysis roughening treatment with metallic copper, secondary treatment surface subjected to smooth plating treatment with metallic copper, and treatment with metallic nickel. A surface-roughened copper foil in which a tertiary treatment surface and a quaternary treatment surface treated with metallic zinc are provided in this order.   At least one surface of the untreated copper foil is subjected to pulse cathodic electrolysis roughening treatment with metallic copper, secondary treatment surface subjected to smooth plating treatment with metallic copper, and treatment with metallic nickel. A surface-roughened copper foil in which a tertiary treatment surface, a quaternary treatment surface treated with metallic zinc, and a rust prevention layer with a rust inhibitor are provided in this order.   At least one surface of the untreated copper foil is subjected to pulse cathodic electrolysis roughening treatment with metallic copper, secondary treatment surface subjected to smooth plating treatment with metallic copper, and treatment with metallic nickel. A surface-roughened copper foil in which a tertiary treatment surface, a quaternary treatment surface treated with metallic zinc, a rust prevention layer with a rust inhibitor, and a protection layer with a coupling agent are provided in this order.   2. The untreated copper foil is an electrolytic copper foil or a rolled copper foil, and the substrate on the surface of the copper foil is in the range of 0.8 to 2.5 [mu] m in Rz value defined in JIS-B-0601. The surface-roughened copper foil in any one of -3.   The surface-roughened copper foil according to any one of claims 1 to 4, wherein an elongation rate of the untreated copper foil in a normal temperature state is 3.5% or more.   5. The surface-roughened copper foil according to claim 1, wherein the roughness after the secondary treatment after the roughening treatment is 3.0 μm or less in terms of an Rz value defined in JIS-B-0601. . The surface-roughened copper foil according to claim 2 or 3, wherein the rust-preventing layer is made of chromate, and the chromium adhesion amount is 0.005 to 0.025 mg / dm ² as metallic chromium. The surface-roughened copper foil according to claim 3, wherein the protective layer is made of a silane coupling agent, and the adhesion amount of the silane coupling agent is 0.001 to 0.015 mg / dm ² as silicon.   At least one surface of the untreated copper foil is subjected to primary roughening made of metallic copper by pulse cathodic electrolysis roughening treatment, and a secondary treatment made of metallic copper is applied to the surface subjected to the primary roughening treatment by smooth plating treatment. A method for producing a surface-roughened copper foil, wherein a tertiary treatment is performed on the secondary roughened surface by treatment with metallic nickel, and a fourth treatment surface is obtained on the tertiary treatment surface by treatment with metal zinc.   The primary surface of the matte surface (liquid surface side) is made of metallic copper by pulse cathodic electrolysis roughening on the matte surface of an electrolytic copper foil having an Rz value of 0.8 to 2.5 μm as defined in JIS-B-0601. The surface roughness of the surface is reduced to 3.0 μm or less by the Rz value defined in JIS-B-0601 by performing a secondary treatment made of metallic copper on the surface subjected to the primary roughening treatment by smooth plating treatment. A method for producing a surface-treated copper foil that is subjected to a tertiary treatment by treatment with metallic nickel on the second roughened surface and a fourth treatment surface by treatment with metallic zinc on the third treatment surface.   The method for producing a surface-roughened copper foil according to claim 9 or 10, wherein an elongation rate of the untreated copper foil in a normal temperature state is 3.5% or more.   At least one surface of the untreated copper foil is subjected to primary roughening made of metallic copper by pulse cathodic electrolysis roughening treatment, and a secondary treatment made of metallic copper is applied to the surface subjected to the primary roughening treatment by smooth plating treatment. The secondary roughened surface is subjected to a tertiary treatment by treatment with metallic nickel, the tertiary treatment surface is subjected to a quaternary treatment surface by treatment with metallic zinc, and then the heat treatment is performed to the metal copper, the metal A method for producing a surface-treated copper foil in which nickel and zinc metal are alloyed.   At least one surface of the untreated copper foil is subjected to primary roughening made of metallic copper by pulse cathodic electrolysis roughening treatment, and a secondary treatment made of metallic copper is applied to the surface subjected to the primary roughening treatment by smooth plating treatment. The secondary roughened surface is subjected to a tertiary treatment by treatment with metallic nickel, the tertiary treatment surface is subjected to a fourth treatment surface by treatment with metallic zinc, and the rust prevention is provided on the fourth treatment surface. A method for producing a surface-treated copper foil obtained by applying a rust preventive layer with an agent.   At least one surface of the untreated copper foil is subjected to primary roughening made of metallic copper by pulse cathodic electrolysis roughening treatment, and a secondary treatment made of metallic copper is applied to the surface subjected to the primary roughening treatment by smooth plating treatment. The secondary roughened surface is subjected to a tertiary treatment by treatment with metallic nickel, the tertiary treatment surface is subjected to a fourth treatment surface by treatment with metallic zinc, and the rust prevention is provided on the fourth treatment surface. A method for producing a surface-treated copper foil in which a rust preventive layer is applied with an agent, and then heat treated to alloy the metal copper, the metal nickel, and the metal zinc.   At least one surface of the untreated copper foil is subjected to primary roughening made of metallic copper by pulse cathodic electrolysis roughening treatment, and a secondary treatment made of metallic copper is applied to the surface subjected to the primary roughening treatment by smooth plating treatment. The secondary roughened surface is subjected to tertiary treatment by treatment with metallic nickel, the tertiary treatment surface is subjected to quaternary treatment by metal zinc treatment, and the rust preventive agent is provided on the fourth treatment surface. A method for producing a surface-treated copper foil provided with a rust-preventing layer and a protective layer with a coupling agent.   At least one surface of the untreated copper foil is subjected to primary roughening made of metallic copper by pulse cathodic electrolysis roughening treatment, and a secondary treatment made of metallic copper is applied to the surface subjected to the primary roughening treatment by smooth plating treatment. The secondary roughened surface is subjected to tertiary treatment by treatment with metallic nickel, the tertiary treatment surface is subjected to quaternary treatment by metal zinc treatment, and the rust preventive agent is provided on the fourth treatment surface. A method for producing a surface-treated copper foil obtained by applying a rust-preventive layer and a protective layer with a coupling agent, and then heat-treating and alloying the metal copper, the metal nickel, and the metal zinc.   The surface-roughened copper foil according to any one of claims 1 to 8, or the surface-roughened copper foil produced by the production method according to any one of claims 9 to 16 is laminated with a flexible resin substrate or a rigid resin substrate. A copper-clad laminate.

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