JP2014224318A - Copper foil for high-frequency circuit, copper-clad laminate sheet for high-frequency circuit, printed wiring board for high-frequency circuit, carrier-provided copper foil for high-frequency circuit, electronic apparatus and method of producing printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide copper foil for high-frequency circuits which suppresses transmission loss well when used in high-frequency circuit boards and also suppresses occurrence of powder falling on the surface of the copper foil well.SOLUTION: In copper foil for high-frequency circuits, a primary particle layer containing copper is formed on the surface of the copper foil, and a secondary particle layer of a ternary-system alloy consisting of copper, cobalt and nickel is formed on the primary particle layer. The copper foil has a color difference Δa* of a roughened surface from white color of 4.0 or smaller and a color difference Δb* of the roughened surface from white color of 3.5 or smaller, measured in the color difference system described in JISZ8730.

Description

  The present invention relates to a copper foil for high-frequency circuits, a copper-clad laminate for high-frequency circuits, a printed wiring board for high-frequency circuits, a copper foil with a carrier for high-frequency circuits, an electronic device, and a method for manufacturing a printed wiring board.

  Printed wiring boards have made great progress over the last half century and are now used in almost all electronic devices. In recent years, with the increasing demand for miniaturization and high performance of electronic devices, high density mounting of mounted components and high frequency of signals have progressed, and excellent high frequency response is required for printed wiring boards.

  The high frequency board is required to reduce transmission loss in order to ensure the quality of the output signal. The transmission loss mainly consists of a dielectric loss due to the resin (substrate side) and a conductor loss due to the conductor (copper foil side). The dielectric loss decreases as the dielectric constant and dielectric loss tangent of the resin decrease. In a high-frequency signal, the conductor loss is mainly caused by a decrease in the cross-sectional area through which the current flows due to the skin effect that only the surface of the conductor flows as the frequency increases, and the resistance increases.

  As a technique aimed at reducing the transmission loss of the high-frequency copper foil, for example, Patent Document 1 covers one or both surfaces of a metal foil surface with silver or a silver alloy metal, and the silver or silver alloy coating. A metal foil for a high-frequency circuit is disclosed in which a coating layer other than silver or a silver alloy is applied on the layer thinner than the thickness of the silver or silver alloy coating layer. And according to this, it describes that the metal foil which made the loss by a skin effect small can be provided also in the superhigh frequency area | region used by sanitary communication.

  Patent Document 2 discloses that the integrated intensity (I (200)) of (200) plane obtained by X-ray diffraction on the rolled surface after recrystallization annealing of the rolled copper foil is the X-ray diffraction of fine powder copper. Roughening treatment after I (200) / I0 (200)> 40 with respect to the obtained integrated strength (I0 (200)) of (200) plane, and after performing roughening treatment by electrolytic plating on the rolled surface The arithmetic average roughness (hereinafter referred to as Ra) of the surface is 0.02 μm to 0.2 μm, the ten-point average roughness (hereinafter referred to as Rz) is 0.1 μm to 1.5 μm, and for printed circuit boards A roughened rolled copper foil for high-frequency circuits, characterized by being a material, is disclosed. And it is described that according to this, the printed circuit board which can be used under the high frequency exceeding 1 GHz can be provided.

  Further, Patent Document 3 discloses an electrolytic copper foil characterized in that a part of the surface of the copper foil is an uneven surface having a surface roughness of 2 μm to 4 μm made of bump-shaped protrusions. And according to this, it describes that the electrolytic copper foil excellent in the high frequency transmission characteristic can be provided.

Japanese Patent No. 4161304 Japanese Patent No. 4770425 JP 2004-244656 A

  The conductor loss due to the conductor (copper foil side) is caused by the increase in resistance due to the skin effect as described above. This resistance is not only the resistance of the copper foil itself but also the resin substrate on the copper foil surface. There is also the influence of the resistance of the surface treatment layer formed by the roughening process performed to ensure the adhesion of the copper, specifically, the roughness of the copper foil surface is the main factor of the conductor loss, the roughness It is known that the transmission loss decreases as the value decreases.

  The present inventors have conducted further studies on the relationship between the roughness of the copper foil surface and the transmission loss, and the transmission loss does not necessarily decrease as the roughness of the copper foil surface decreases. When the surface roughness is reduced to a certain extent, there is a marked variation in the relationship between the reduction in transmission loss and the copper foil surface roughness, and transmission loss can be satisfactorily reduced only by controlling the copper foil surface roughness. I found it difficult.

  Further, as the roughening treatment of the copper foil surface, the formation of a cobalt-nickel alloy plating layer is known, but the conventional copper foil having a cobalt-nickel alloy plating layer formed thereon is a copper- Since the shape of the roughened particles made of cobalt-nickel alloy plating is dendritic, it peels off from the upper part or the root of the dendron, causing a problem generally referred to as a powder-off phenomenon.

  This powder-off phenomenon is a troublesome problem. Despite the fact that the roughened layer of copper-cobalt-nickel alloy plating has excellent heat resistance, particles can easily fall off due to external force. The problem was that peeling due to “rubbing” during processing, contamination of the roll with peeling powder, and etching residue due to peeling powder were generated.

  Therefore, the present invention suppresses transmission loss satisfactorily even when used for a high-frequency circuit board, and causes a phenomenon in which roughened particles formed on the surface of the copper foil peel off from the surface, so-called “powder-off”. An object of the present invention is to provide a high-frequency circuit copper foil, a high-frequency circuit copper-clad laminate, a high-frequency circuit printed wiring board, and a high-frequency circuit printed circuit board.

  The present inventor uses a high-frequency circuit board to form a predetermined roughened particle layer on the surface of the ultrathin copper layer of the copper foil with carrier and to control a predetermined color difference on the surface of the roughened particle layer. It has been found that it is extremely effective for suppressing transmission loss when it is in contact with the copper foil and for suppressing powder falling on the surface of the copper foil.

  The present invention has been completed on the basis of the above knowledge, and in one aspect, after forming a primary particle layer containing copper on the surface of the copper foil, the primary particle layer is made of copper, cobalt and nickel. A copper foil in which a secondary particle layer containing a ternary alloy is formed, and a color difference Δa * value with respect to white when a color difference of a roughened surface is measured in a color difference system described in JISZ8730 is 4.0 or less, It is a copper foil for high frequency circuits having a color difference Δb * value of 3.5 or less.

  In one embodiment, the copper foil for a high-frequency circuit of the present invention has an average particle diameter of the copper primary particle layer of 0.25 to 0.45 μm, and a secondary alloy composed of a ternary alloy composed of copper, cobalt, and nickel. The average particle size of the particle layer is 0.35 μm or less.

  In another embodiment, the copper foil for a high-frequency circuit of the present invention has a color difference ΔL * value of −30 to −50 from white when the color difference of the roughened surface is measured in a color difference system.

  In yet another embodiment of the copper foil for a high-frequency circuit of the present invention, the primary particle layer and the secondary particle layer are electroplated layers.

  In yet another embodiment of the copper foil for a high-frequency circuit of the present invention, the secondary particles are one or more dendritic particles grown on the primary particles or normal plating grown on the primary particles. Is a layer.

  In yet another embodiment of the copper foil for a high-frequency circuit of the present invention, the adhesive strength between the primary particle layer and the secondary particle layer is 0.80 kg / cm or more.

  In yet another embodiment of the copper foil for a high-frequency circuit of the present invention, the adhesive strength between the primary particle layer and the secondary particle layer is 0.90 kg / cm or more.

In yet another embodiment, the copper foil for a high-frequency circuit of the present invention, on the secondary particle layer,
(A) an alloy layer composed of Ni and one or more elements selected from the group consisting of Fe, Cr, Mo, Zn, Ta, Cu, Al, P, W, Mn, Sn, As, and Ti, and
(B) Either one or both of the chromate layers are formed.

In yet another embodiment, the copper foil for a high-frequency circuit of the present invention, on the secondary particle layer,
(A) an alloy layer composed of Ni and one or more elements selected from the group consisting of Fe, Cr, Mo, Zn, Ta, Cu, Al, P, W, Mn, Sn, As, and Ti, and
(B) one or both of the chromate layers,
The silane coupling layer is formed in this order.

In yet another embodiment, the copper foil for a high-frequency circuit of the present invention, on the secondary particle layer,
Either one or both of the Ni—Zn alloy layer and the chromate layer are formed.

In yet another embodiment, the copper foil for a high-frequency circuit of the present invention, on the secondary particle layer,
Either one or both of the Ni-Zn alloy layer and the chromate layer,
The silane coupling layer is formed in this order.

  In yet another embodiment, the high-frequency circuit copper foil of the present invention comprises a resin layer on the surface of the secondary particle layer.

  In still another embodiment, the copper foil for a high-frequency circuit according to the present invention is from the group consisting of Ni, Fe, Cr, Mo, Zn, Ta, Cu, Al, P, W, Mn, Sn, As, and Ti. A resin layer is provided on the surface of the alloy layer composed of one or more selected elements, the chromate layer, the silane coupling layer, or the Ni—Zn alloy layer.

  Another aspect of the present invention is a copper foil with a carrier having an intermediate layer and an ultrathin copper layer in this order on one or both sides of the carrier, wherein the ultrathin copper layer is the present invention. It is a copper foil with a carrier which is a copper foil for high frequency circuits.

  In one embodiment, the copper foil with a carrier of the present invention has the intermediate layer and the ultrathin copper layer in this order on one surface of the carrier, and a roughening treatment layer on the other surface of the carrier.

  In yet another aspect, the present invention is a copper clad laminate for a high frequency circuit using the copper foil of the present invention.

  In yet another aspect, the present invention is a printed wiring board for a high-frequency circuit using the copper foil of the present invention.

  In one embodiment, the copper-clad laminate for a high-frequency circuit of the present invention is obtained by laminating the copper foil and polyimide, liquid crystal polymer, or fluororesin.

  In one embodiment, the printed wiring board for a high-frequency circuit of the present invention uses polyimide, liquid crystal polymer, or fluororesin.

  In still another aspect, the present invention is an electronic device using the printed wiring board of the present invention.

In another aspect of the present invention, a step of preparing the carrier-attached copper foil of the present invention and an insulating substrate
Laminating the copper foil with carrier and an insulating substrate;
After laminating the carrier-attached copper foil and the insulating substrate, a copper-clad laminate is formed through a step of peeling the carrier of the carrier-attached copper foil,
Thereafter, the printed wiring board manufacturing method includes a step of forming a circuit by any one of a semi-additive method, a subtractive method, a partly additive method, or a modified semi-additive method.

In yet another aspect of the present invention, a step of forming a circuit on the ultrathin copper layer side surface of the copper foil with a carrier of the present invention,
Forming a resin layer on the ultrathin copper layer side surface of the carrier-attached copper foil so that the circuit is buried;
Forming a circuit on the resin layer;
Forming the circuit on the resin layer, and then peeling the carrier; and
After the carrier is peeled off, the printed wiring board includes a step of exposing the circuit embedded in the resin layer formed on the surface of the ultrathin copper layer by removing the ultrathin copper layer Is the method.

  According to the present invention, transmission loss is satisfactorily suppressed even when used for a high-frequency circuit board, and the occurrence of so-called “powder-off” phenomenon in which roughened particles formed on the surface of the copper foil peel off from the surface is good. It is possible to provide a high-frequency circuit copper foil, a high-frequency circuit copper-clad laminate, a high-frequency circuit printed wiring board, and a high-frequency circuit printed circuit board.

It is a conceptual explanatory drawing which shows the mode of the powder fall at the time of performing the roughening process which consists of copper-cobalt-nickel alloy plating on the conventional copper foil. Conceptual explanation of a copper foil treatment layer without powder falling, wherein a primary particle layer is formed in advance on a copper foil and a secondary particle layer made of copper-cobalt-nickel alloy plating is formed on the primary particle layer of the present invention. FIG. It is a microscope picture of the surface at the time of performing the roughening process which consists of copper-cobalt-nickel alloy plating on the conventional copper foil. The primary particle layer is formed in advance on the copper foil of the present invention, and the secondary particle layer made of copper-cobalt-nickel alloy plating is formed on the primary particle layer. It is a micrograph. AC is a schematic diagram of the wiring board cross section in the process to circuit plating and the resist removal based on the specific example of the manufacturing method of the printed wiring board using the copper foil with a carrier of this invention. DF is a schematic diagram of a cross section of a wiring board in a process from lamination of a resin and copper foil with a second layer carrier to laser drilling according to a specific example of a method for producing a printed wiring board using a copper foil with a carrier of the present invention. It is. GI is a schematic diagram of the wiring board cross section in the process from the via fill formation to the first layer carrier peeling according to a specific example of the method for manufacturing a printed wiring board using the carrier-attached copper foil of the present invention. J to K are schematic views of a cross section of a wiring board in steps from flash etching to bump / copper pillar formation according to a specific example of a method of manufacturing a printed wiring board using the carrier-attached copper foil of the present invention.

There is no restriction | limiting in particular in the form of the copper foil base material which can be used for this invention, Typically, the copper foil used in this invention may be either an electrolytic copper foil or a rolled copper foil. In general, the electrolytic copper foil is produced by electrolytic deposition of copper from a copper sulfate plating bath onto a drum of titanium or stainless steel, and the rolled copper foil is produced by repeating plastic working and heat treatment with a rolling roll. Rolled copper foil is often used for applications that require flexibility.
In addition to high-purity copper such as tough pitch copper and oxygen-free copper, which are usually used as conductor patterns for printed wiring boards, for example, Sn-containing copper, Ag-containing copper, Cr, Zr or Mg are added as the copper foil base material. It is also possible to use a copper alloy such as a copper alloy, a Corson copper alloy to which Ni, Si and the like are added. In addition, when the term “copper foil” is used alone in this specification, a copper alloy foil is also included.
The thickness of the copper foil substrate need not be particularly limited, but for example, 1 to 1000 μm, alternatively 1 to 500 μm, alternatively 1 to 300 μm, alternatively 3 to 100 μm, alternatively 5 to 70 μm, alternatively 6 to 35 μm, or 9 ˜18 μm.
Moreover, this invention is a copper foil with a carrier which has a carrier, an intermediate | middle layer, and an ultra-thin copper layer in this order in another side surface, Comprising: The copper with a carrier whose said ultra-thin copper layer is a copper foil for high frequency circuits of this invention It is a foil. That is, in another aspect of the present invention, a copper foil with a carrier having a carrier, an intermediate layer, and an ultrathin copper layer in this order can be used as a copper foil base material. When using copper foil with a carrier in this invention, surface treatment layers, such as the following roughening process layers, are provided in the ultra-thin copper layer surface. In addition, another embodiment of the copper foil with a carrier will be described later.

Usually, the surface of the copper foil to be bonded to the resin base material, that is, the roughened surface, is formed on the surface of the copper foil after degreasing for the purpose of improving the peel strength of the copper foil after lamination. A roughening process is performed for electrodeposition. Although the electrolytic copper foil has irregularities at the time of manufacture, the irregularities are further increased by enhancing the convex portions of the electrolytic copper foil by roughening treatment. Ordinary copper plating or the like may be performed as a pretreatment before roughening, and ordinary copper plating or the like may be performed as a finishing treatment after roughening in order to prevent electrodeposits from dropping off.
In the present invention, including such pretreatment and finishing treatment, a known treatment related to copper foil roughening is included as necessary, and is referred to as “roughening treatment”.

  This roughening treatment is performed by copper-cobalt-nickel alloy plating (in the following description, the roughening treatment of copper-cobalt-nickel alloy plating is performed to clarify the difference from the previous step. , Referred to as “secondary particle layer”), as described above, simply forming a copper-cobalt-nickel alloy plating layer on the copper foil causes problems such as powder falling as described above. .

The microscope picture of the surface of the copper foil which formed the copper-cobalt-nickel alloy plating layer on copper foil is shown in FIG. As shown in FIG. 3, fine particles developed in a dendritic shape can be seen. In general, the fine particles developed in a dendritic shape shown in FIG. 3 are produced at a high current density.
When processed at such a high current density, particle nucleation during initial electrodeposition is suppressed, and new particle nuclei are formed at the tip of the particle. Will grow.
Therefore, to prevent this, when electroplating is performed at a reduced current density, there is no sharp rise, the number of particles increases, and rounded particles grow. However, even in such a situation, powder falling is slightly improved, but sufficient peel strength is not obtained, which is not sufficient to achieve the object of the present invention.

  The state of powder falling when the copper-cobalt-nickel alloy plating layer as shown in FIG. 3 is formed is shown in the conceptual explanatory diagram of FIG. The cause of this powder fall is that fine particles are formed in a dendritic shape on the copper foil as described above. However, the dendritic particles are easily broken by an external force and fall off from the root. The fine dendritic particles cause peeling due to “rubbing” during the process, contamination of the roll with peeling powder, and etching residue due to peeling powder.

In the present invention, a primary particle layer of copper is formed in advance on the surface of the copper foil, and then a secondary particle layer composed of a ternary alloy composed of copper, cobalt and nickel is formed on the primary particle layer. To do. FIG. 4 shows a micrograph of the surface on which the primary particles and secondary particles are formed on the copper foil (details will be described later).
This eliminates peeling due to “rubbing” during processing, dirt on the roll due to peeling powder, and etching residue due to peeling powder, that is, a phenomenon called powder falling can be suppressed, peel strength is increased, and high-frequency characteristics are improved. The copper foil for high frequency circuits which can be improved can be obtained.

  The average particle diameter of the primary particle layer is 0.25 to 0.45 μm, and the average particle diameter of the secondary particle layer made of a ternary alloy made of copper, cobalt and nickel is 0.35 μm or less. As is apparent from the examples shown in (1), this is the optimum condition for preventing powder falling off. The lower limit of the average particle diameter of the primary particle layer is preferably 0.27 μm or more, preferably 0.29 μm or more, more preferably 0.30 μm or more, more preferably 0.33 μm or more. The upper limit of the average particle diameter of the primary particle layer is preferably 0.44 μm or less, preferably 0.43 μm or less, preferably 0.40 μm or less, preferably 0.39 μm or less. The upper limit of the average particle size of the secondary particle layer is preferably 0.34 μm or less, preferably 0.33 μm or less, preferably 0.32 μm or less, preferably 0.31 μm or less, preferably 0.30 μm or less, preferably Is 0.28 μm or less, preferably 0.27 μm or less. Further, the lower limit of the average particle diameter of the secondary particle layer is not particularly limited. For example, 0.001 μm or more, or 0.01 μm or more, or 0.05 μm or more, or 0.09 μm or more, or 0.10 μm or more. Or 0.12 μm or more, or 0.15 μm or more.

The primary particle layer and the secondary particle layer are formed by an electroplating layer. The secondary particles are characterized by one or more dendritic particles grown on the primary particles. Or normal plating grown on the primary particles. That is, in the present specification, when the term “secondary particle layer” is used, a normal plating layer such as overlay plating is also included. Further, the secondary particle layer may be a layer having one or more layers formed of roughened particles, or may be a layer having one or more normal plating layers, and is normal with a layer formed of roughened particles. It may be a layer having one or more plating layers.
The primary particle layer and the secondary particle layer thus formed can achieve an adhesive strength of 0.80 kg / cm or more, and further an adhesive strength of 0.90 kg / cm or more.

  In the copper foil formed with the primary particle layer and the secondary particle layer, more importantly, the color tone of the roughened surface of the copper foil is gray or black, and the color difference of the roughened surface in the color difference system described in JISZ8730. The color difference Δa * value with respect to white when measured is 4.0 or less, and the color difference Δb * value is 3.5 or less. This color tone is obtained by examining a color difference based on JIS Z 8730. A МiniScan XE Plus color difference meter manufactured by HunterLab was used for color difference measurement. With this color difference meter, the color difference on the white plate is set to zero in the calibration work before measurement, and after performing other calibration work according to the instruction manual of the color difference meter, the color difference of the copper foil roughened surface is measured. The color differences Δa *, Δb *, and ΔL * from the white color were determined. The same applies hereinafter.

In the copper foil in which the primary particle layer and the secondary particle layer are formed, the color tone is gray or black, the color difference Δa * value with respect to white when the color difference of the roughened surface is measured is 4.0 or less, and the color difference Δb * The value is 3.5 or less. The upper limit of the color difference Δa * value with respect to white when the color difference of the roughened surface of the copper foil is measured is preferably 3.5 or less. Further, the lower limit of the color difference Δa * value with white when measuring the color difference of the roughened surface of the copper foil is not particularly limited, but is, for example, 0 or more, 0.01 or more, 0.05 or more, Or it is 0.1 or more, or 0.3 or more, or 0.5 or more, or 1.0 or more, or 1.3 or more, or 1.5 or more.
Further, the upper limit of the color difference Δb * value with respect to white when the color difference of the roughened surface of the copper foil is measured is preferably 3.3 or less. Further, the lower limit of the color difference Δb * value with respect to white when the color difference of the roughened surface of the copper foil is measured is not necessarily limited, but is, for example, 0 or more, 0.01 or more, 0.05 or more, or It is 0.1 or more, or 0.3 or more, or 0.5 or more, or 0.8 or more, or 1.0 or more, or 1.1 or more, or 1.3 or more.

  In the flexible printed wiring board (FPC), semiconductor mounting technology has been advanced by high definition and high density, and the alignment accuracy by image recognition of the copper foil circuit through the resin substrate of the FPC is also important. . As the FPC substrate resin, a polyimide resin is mainly used, and the color of the polyimide resin is yellow. In the color difference system of JISZ8730, the color difference Δa * value from white approaches red as the value increases, and the color difference Δb * value approaches yellow as the value increases. Therefore, the color tone of the roughened surface of the copper foil used for FPC is gray or black, that is, the smaller the color difference Δa * value and Δb * value, the different the appearance from red or yellow, and the polyimide resin substrate It becomes possible to clarify the distinction between colors. Furthermore, such adjustment of the color difference has an effect of stably improving the peel strength and preventing the powder falling phenomenon. If the color difference Δa * value is greater than 4.0 or greater, or if the color difference Δb * value is greater than 3.5 or greater, powder fall is likely to occur. This is desirable.

  Moreover, in the copper foil which formed the primary particle layer and the secondary particle layer, it is preferable that color difference (DELTA) L * with white at the time of measuring the color difference of the roughening process surface of copper foil is -30--50. This is because when the color difference ΔL * from the white when the color difference of the roughened surface of the copper foil is measured is in the range of −30 to −50, powder falling tends to hardly occur. The lower limit of the color difference ΔL * from white when the color difference of the roughened surface of the copper foil is measured is preferably −49.5 or more, more preferably −49.0 or more. Moreover, the upper limit of the color difference ΔL * from white when the color difference of the roughened surface of the copper foil is measured is preferably −31 or less, more preferably −32 or less, more preferably −33 or less. Yes, more preferably -35 or less, more preferably -40 or less.

  The “roughening surface” in the “color difference of the roughening surface of the copper foil” means the surface on the final product, and means the outermost surface on the side where the primary particle layer and the secondary particle layer are formed. . Moreover, when surface treatment layers, such as a heat-resistant layer, a rust prevention layer, a silane coupling process layer, are formed on a secondary particle layer, the outermost surface of the said surface treatment layer is meant. In addition, when the below-mentioned "resin layer" is formed, the outermost surface of the side in which the primary particle layer and secondary particle layer of the copper foil except the said resin layer were formed is meant.

On the secondary particle layer,
(A) an alloy layer composed of Ni and one or more elements selected from the group consisting of Fe, Cr, Mo, Zn, Ta, Cu, Al, P, W, Mn, Sn, As, and Ti, and (B) Either one or both of the chromate layers may be formed.
Further, on the secondary particle layer, (A) one or more selected from the group consisting of Ni, Fe, Cr, Mo, Zn, Ta, Cu, Al, P, W, Mn, Sn, As, and Ti One or both of the alloy layer made of the element and the (B) chromate layer, and the silane coupling layer may be formed in this order.
Furthermore, either or both of the Ni—Zn alloy layer and the chromate layer may be formed on the secondary particle layer.
Furthermore, a Ni—Zn alloy layer and / or a chromate layer, or both, and a silane coupling layer may be formed in this order on the secondary particle layer.
According to such a configuration, it is possible to improve the high-frequency transmission characteristics while maintaining the peel strength.

[Transmission loss]
When the transmission loss is small, attenuation of the signal when performing signal transmission at a high frequency is suppressed, so that a stable signal transmission can be performed in a circuit that transmits the signal at a high frequency. Therefore, a smaller transmission loss value is preferable because it is suitable for use in a circuit for transmitting a signal at a high frequency. After bonding the surface-treated copper foil to a commercially available liquid crystal polymer resin (Vecstar CTZ-50 μm manufactured by Kuraray Co., Ltd.), a microstrip line is formed by etching so that the characteristic impedance is 50Ω, and a network manufactured by HP When the transmission coefficient is measured using the analyzer HP8720C and the transmission loss at a frequency of 20 GHz and a frequency of 40 GHz is determined, the transmission loss at a frequency of 20 GHz is preferably less than 5.0 dB / 10 cm, and more preferably less than 4.1 dB / 10 cm. Preferably, less than 3.7 dB / 10 cm is even more preferable.

The surface-treated copper foil of the present invention can be bonded to a resin substrate from the roughened surface side to produce a laminate. The resin substrate is not particularly limited as long as it has characteristics applicable to a printed wiring board or the like. For example, a paper base phenol resin, a paper base epoxy resin, a synthetic fiber cloth base epoxy resin for rigid PWB Glass cloth / paper composite base material epoxy resin, glass cloth / glass nonwoven fabric composite base material epoxy resin and glass cloth base material epoxy resin, etc. are used, polyester film, polyimide film, liquid crystal polymer (LCP) film, fluorine for FPC Resin etc. can be used. In addition, when a liquid crystal polymer (LCP) film or a fluororesin film is used, the peel strength between the film and the surface-treated copper foil tends to be smaller than when a polyimide film is used. Therefore, when a liquid crystal polymer (LCP) film or a fluororesin film is used, the copper circuit is covered with a coverlay after the copper circuit is formed, so that the film and the copper circuit are not easily peeled off, and the peel strength is reduced. The film can be prevented from peeling off from the copper circuit.
In addition, since a liquid crystal polymer (LCP) film and a fluororesin film have a small dielectric loss tangent, the copper clad laminated board using a liquid crystal polymer (LCP) film or a fluororesin film and the surface-treated copper foil which concerns on this invention, printed wiring Boards and printed circuit boards are suitable for high-frequency circuits (circuits that transmit signals at high frequencies). Further, the surface-treated copper foil according to the present invention has a small surface roughness Rz and a high glossiness, so that the surface is smooth and suitable for high-frequency circuit applications.

  In the case of the rigid PWB, a prepreg is prepared by impregnating a base material such as a glass cloth with a resin and curing the resin to a semi-cured state. It can be carried out by superposing a copper foil on the prepreg from the opposite surface of the coating layer and heating and pressing. In the case of FPC, it is laminated on a copper foil under high temperature and high pressure without using an adhesive on a substrate such as a polyimide film, or a polyimide precursor is applied, dried, cured, etc. A laminated board can be manufactured by performing.

  The laminate of the present invention can be used for various printed wiring boards (PWB) and is not particularly limited. For example, from the viewpoint of the number of layers of the conductor pattern, the single-sided PWB, the double-sided PWB, and the multilayer PWB (3 It is applicable to rigid PWB, flexible PWB (FPC), and rigid flex PWB from the viewpoint of the type of insulating substrate material.

Furthermore, a printed circuit board is completed by mounting electronic components on the printed wiring board. In the present invention, the “printed wiring board” includes a printed wiring board, a printed circuit board, and a printed board on which electronic parts are mounted as described above.
In addition, an electronic device may be manufactured using the printed wiring board, an electronic device may be manufactured using a printed circuit board on which the electronic components are mounted, and a print on which the electronic components are mounted. An electronic device may be manufactured using a substrate.

(Plating conditions for primary particles of copper)
An example of copper primary particle plating conditions is as follows.
In addition, this plating condition shows a suitable example to the last, and the average particle diameter formed on copper foil plays the role of powder fall-off prevention as the primary particle of copper. Therefore, as long as the average particle diameter is within the range of the present invention, the plating conditions other than those indicated below are not disturbed. The present invention includes these.
Liquid composition: Copper 10-20 g / L, sulfuric acid 50-100 g / L
Liquid temperature: 25-50 degreeC
Current density: 1 to 58 A / dm ²
Coulomb amount: 4 to 81 As / dm ²

(Plating conditions for secondary particles)
As described above, this plating condition is only a preferable example, the secondary particles are formed on the primary particles, and the average particle diameter plays a role of preventing powder falling. is there. Therefore, as long as the average particle diameter is within the range of the present invention, the plating conditions other than those indicated below are not disturbed. The present invention includes these.
Liquid composition: Copper 10-20 g / L, nickel 5-15 g / L, cobalt 5-15 g / L
pH: 2-3
Liquid temperature: 30-50 degreeC
Current density: 24 to 50 A / dm ²
Coulomb amount: 34 to 48 As / dm ²

(Plating conditions for forming the heat-resistant layer 1) (Co-Ni plating: cobalt nickel alloy plating)
In the present invention, a heat-resistant layer can be further formed on the secondary particle layer. The plating conditions are shown below.
Liquid composition: Nickel 5-20 g / L, cobalt 1-8 g / L
pH: 2-3
Liquid temperature: 40-60 degreeC
Current density: 5 to 20 A / dm ²
Coulomb amount: 10-20 As / dm ²

(Plating conditions for forming the heat-resistant layer 2) (Ni-Zn plating: nickel zinc alloy plating)
In the present invention, the following heat-resistant layer can be further formed on the secondary particle layer. The plating conditions are shown below.
Liquid composition: nickel 2-30 g / L, zinc 2-30 g / L
pH: 3-4
Liquid temperature: 30-50 degreeC
Current density: 1 to ^{2 A} / dm ²
Coulomb amount: 1-2 As / dm ²

(Plating conditions for forming the heat-resistant layer 3) (Ni-Cu plating: nickel copper alloy plating)
In the present invention, the following heat-resistant layer can be further formed on the secondary particle layer. The plating conditions are shown below.
Liquid composition: Nickel 2-30 g / L, Copper 2-30 g / L
pH: 3-4
Liquid temperature: 30-50 degreeC
Current density: 1 to ^{2 A} / dm ²
Coulomb amount: 1-2 As / dm ²

(Plating conditions for forming the heat-resistant layer 4) (Ni-Mo plating: nickel molybdenum alloy plating)
In the present invention, the following heat-resistant layer can be further formed on the secondary particle layer. The plating conditions are shown below.
Liquid composition: Ni sulfate hexahydrate: 45-55 g / dm ³ , Sodium molybdate dihydrate: 50-70 g / dm ³ , Sodium citrate: 80-100 g / dm ³
Liquid temperature: 20-40 degreeC
Current density: 1 to 4 A / dm ²
Coulomb amount: 1-2 As / dm ²

(Plating conditions for forming the heat-resistant layer 5) (Ni-Sn plating: nickel tin alloy plating)
In the present invention, the following heat-resistant layer can be further formed on the secondary particle layer. The plating conditions are shown below.
Liquid composition: Nickel 2-30 g / L, tin 2-30 g / L
pH: 1.5-4.5
Liquid temperature: 30-50 degreeC
Current density: 1 to ^{2 A} / dm ²
Coulomb amount: 1-2 As / dm ²

(Plating conditions for forming the heat-resistant layer 6) (Ni-P plating: nickel phosphorus alloy plating)
In the present invention, the following heat-resistant layer can be further formed on the secondary particle layer. The plating conditions are shown below.
Liquid composition: nickel 30-70 g / L, phosphorus 0.2-1.2 g / L
pH: 1.5-2.5
Liquid temperature: 30-40 degreeC
Current density: 1 to ^{2 A} / dm ²
Coulomb amount: 1-2 As / dm ²

(Plating conditions for forming the heat-resistant layer 7) (Ni-W plating: nickel tungsten alloy plating)
In the present invention, the following heat-resistant layer can be further formed on the secondary particle layer. The plating conditions are shown below.
Liquid composition: Nickel 2-30 g / L, W 0.01-5 g / L
pH: 3-4
Liquid temperature: 30-50 degreeC
Current density: 1 to ^{2 A} / dm ²
Coulomb amount: 1-2 As / dm ²

(Plating conditions for forming the heat-resistant layer 8) (Ni-Cr plating: nickel chromium alloy plating)
In the present invention, the following heat-resistant layer can be further formed on the secondary particle layer. The plating conditions are shown below.
A nickel chromium alloy plating layer was formed using a sputtering target having a composition of Ni: 65 to 85 mass% and Cr: 15 to 35 mass%.
Target: Ni: 65-85 mass%, Cr: 15-35 mass%
Equipment: Sputtering equipment manufactured by ULVAC, Inc. Output: DC50W
Argon pressure: 0.2 Pa

(Plating conditions for forming a rust prevention layer)
The present invention can further form the following antirust layer. The plating conditions are shown below. In the following, conditions for the immersion chromate treatment are shown, but electrolytic chromate treatment may be used.
Liquid composition: potassium dichromate 1-10 g / L, zinc 0-5 g / L
pH: 3-4
Liquid temperature: 50-60 degreeC
Current density: 0 to ^{2 A} / dm ² (0 A / dm ² is the case of immersion chromate treatment)
Coulomb amount: 0 to ^{2 As} / dm ² (0 As / dm ² is the case of immersion chromate treatment.)

(Type of weathering layer (silane coupling layer))
As an example, application of a diaminosilane aqueous solution can be mentioned.
In addition, when a metal layer such as a heat-resistant layer and a plating layer are provided by dry plating such as sputtering, and when a metal layer such as a heat-resistant layer and a plating layer are provided by wet plating, the heat-resistant layer When the metal layer and the plating layer are normal plating (smooth plating, that is, plating performed at a current density lower than the limit current density), the metal layer and the plating layer do not affect the shape of the surface of the copper foil.
The limit current density varies depending on the metal concentration, pH, liquid supply speed, distance between electrodes, and plating solution temperature. In the present invention, normal plating (a state where the plated metal is deposited in a layered manner) and rough plating ( The limiting current density is defined as the current density at the boundary between the burned plating and the plated metal being crystallized (spherical, needle-like or rime-like, etc.). The current density (visual judgment) at the limit for normal plating (immediately before the burn plating) is defined as the limit current density.
Specifically, the metal concentration, pH, and plating solution temperature are set as plating production conditions, and a hull cell test is performed. Then, the metal layer formation state at the plating solution composition and the plating solution temperature (whether the plated metal is deposited in a layer form or a crystal form) is investigated. Then, based on the current density quick reference table manufactured by Yamamoto Co., Ltd., the current density at the boundary position is determined from the position of the test piece where the normal plating / roughening plating boundary exists. The current density at the boundary position is defined as the limit current density. Thereby, the limiting current density at the plating solution composition and the plating solution temperature is known. Generally, when the distance between the electrodes is short, the limit current density tends to increase.
The method of the Hull cell test is described in, for example, “Plating Practice Reader”, Kiyoshi Maruyama, Nikkan Kogyo Shimbun, Ltd., pages 157 to 160 on June 30, 1983.
In addition, in order to perform the plating process below the limit current density, the current density during the plating process is preferably 20 A / dm ² or less, preferably 10 A / dm ² or less, and 8 A / dm ² or less. It is preferable to do.
Moreover, since the thickness of the chromate layer and the silane coupling layer is extremely thin, the color difference on the surface of the copper foil is not affected.

The copper-cobalt-nickel alloy plating as the secondary particles is a ternary alloy of 10-30 mg / dm ² copper-100-3000 μg / dm ² cobalt-50-500 μg / dm ² nickel by electrolytic plating. A layer can be formed.
When the amount of deposited Co is less than 100 μg / dm ² , the heat resistance is deteriorated and the etching property is also deteriorated. When the amount of Co deposition exceeds 3000 μg / dm ² , it is not preferable when the influence of magnetism must be taken into account, etching spots occur, and deterioration of acid resistance and chemical resistance can be considered.

When the Ni adhesion amount is less than 50 μg / dm ² , the heat resistance deteriorates. On the other hand, when the Ni adhesion amount exceeds 500 μg / dm ² , the etching property is lowered. That is, although it is not at a level where etching remains and etching cannot be performed, it becomes difficult to form a fine pattern. Preferred Co deposition amount is 500~2000μg / dm ^2, and preferably nickel coating weight is 50~300μg / dm ^2.
From the above, it can be said that the adhesion amount of the copper-cobalt-nickel alloy plating is desirably 10 to 30 mg / dm ² copper-100 to 3000 μg / dm ² cobalt-50 to 500 μg / dm ² nickel. Each adhesion amount of the ternary alloy layer is a desirable condition, and a range exceeding this amount is not denied.

Here, the etching stain means that Co remains without being dissolved when etched with copper chloride, and the etching residue means that Ni remains undissolved when alkaline etching is performed with ammonium chloride. It means to end.
In general, when a circuit is formed, an alkaline etching solution and a copper chloride based etching solution as described in the following examples are used. Although this etching solution and etching conditions are versatile, it should be understood that they are not limited to these conditions and can be arbitrarily selected.

In the present invention, as described above, after the secondary particles are formed (after the roughening treatment), a cobalt-nickel alloy plating layer can be formed on the roughened surface.
The cobalt-nickel alloy plating layer preferably has a cobalt adhesion amount of 200 to 3000 μg / dm ² and a cobalt ratio of 60 to 66 mass%. This treatment can be regarded as a kind of rust prevention treatment in a broad sense.
This cobalt-nickel alloy plating layer needs to be performed to such an extent that the adhesive strength between the copper foil and the substrate is not substantially lowered. A cobalt adhesion amount of less than 200 μg / dm ² is not preferable because the heat-resistant peel strength is lowered, the oxidation resistance and chemical resistance are deteriorated, and the treated surface becomes reddish.
On the other hand, when the cobalt adhesion amount exceeds 3000 μg / dm ² , it is not preferable when the influence of magnetism must be taken into consideration, etching spots occur, and deterioration of acid resistance and chemical resistance is considered. A preferable cobalt adhesion amount is 400 to 2500 μg / dm ² .

Moreover, when there is much cobalt adhesion amount, it may become a cause of generation | occurrence | production of a soft etching penetration. From this, it can be said that the ratio of cobalt is preferably 60 to 66 mass%.
As will be described later, the direct cause of soft etching soaking is a heat-resistant rust-proof layer composed of a zinc-nickel alloy plating layer, but cobalt may also cause stains during soft etching. The above adjustment is a more desirable condition.
On the other hand, when the nickel adhesion amount is small, the heat-resistant peel strength is lowered, and the oxidation resistance and chemical resistance are lowered. Further, when the nickel adhesion amount is too large, the alkali etching property is deteriorated, so it is desirable to determine the balance with the cobalt content.

In the present invention, a zinc-nickel alloy plating layer can be further formed on the cobalt-nickel alloy plating. The total amount of the zinc-nickel alloy plating layer is 150 to 500 μg / dm ² , and the nickel ratio is 16 to 40% by mass. This has a role of a heat-resistant rust-proof layer. This condition is also a preferable condition, and other known zinc-nickel alloy plating can be used. It will be understood that this zinc-nickel alloy plating is a preferred additional condition in the present invention.
The processing performed in the circuit manufacturing process becomes much hotter, and there is heat generation during use of the device after it has become a product. For example, in a so-called two-layer material in which a copper foil is bonded to a resin by thermocompression bonding, the resin receives heat of 300 ° C. or higher. Even in such a situation, it is necessary to prevent a decrease in bonding force between the copper foil and the resin base material, and this zinc-nickel alloy plating is effective.

In addition, in the conventional technology, in a minute circuit provided with a zinc-nickel alloy plating layer in a two-layer material in which a copper foil is bonded to a resin by thermocompression bonding, discoloration due to penetration into the edge portion of the circuit is caused during soft etching. Occur. Nickel has an effect of suppressing penetration of an etching agent (etching aqueous solution of H ₂ SO ₄ : 10 wt%, H ₂ O ₂ : 2 wt%) used in soft etching.
As described above, the total amount of the zinc-nickel alloy plating layer is 150 to 500 μg / dm ² , the lower limit of the nickel ratio in the alloy layer is 16% by mass, the upper limit is 40% by mass, and nickel A content of 50 μg / dm ² or more serves as a heat-resistant rust-preventing layer and suppresses the penetration of the etchant used during soft etching to prevent weakening of the circuit joint strength due to corrosion. It has the effect that it can be done.

Incidentally, zinc - in the total amount is less than 150 [mu] g / dm ² of nickel alloy plating layer, it is difficult to play a role as a heat-resistant anticorrosive layer heat rust prevention is reduced and the total amount is more than 500 [mu] g / dm ² The hydrochloric acid resistance tends to deteriorate.
Moreover, if the lower limit of the nickel ratio in the alloy layer is less than 16% by mass, the amount of penetration at the time of soft etching exceeds 9 μm, which is not preferable. The upper limit value of 40% by mass of the nickel ratio is a technical limit value at which a zinc-nickel alloy plating layer can be formed.

As described above, the present invention can sequentially form a cobalt-nickel alloy plating layer and further a zinc-nickel alloy plating layer on the copper-cobalt-nickel alloy plating layer as the secondary particle layer as necessary. it can. The total amount of cobalt and nickel deposited in these layers can also be adjusted. It is desirable that the total adhesion amount of cobalt is 300 to 4000 μg / dm ² and the total adhesion amount of nickel is 100 to 1500 μg / dm ² .
When the total deposit amount of cobalt is less than 300 μg / dm ² , the heat resistance and chemical resistance are deteriorated. When the total deposit amount of cobalt exceeds 4000 μg / dm ² , etching spots may occur and transmission loss is large. There is a case. Moreover, if the total adhesion amount of nickel is less than 100 μg / dm ² , heat resistance and chemical resistance may be deteriorated. If the total adhesion amount of nickel exceeds 1500 μg / dm ² , etching residue may occur and transmission loss may increase.
Preferably, the total deposition amount of cobalt 300~3500μg / dm ^2, more preferably 300~3000μg / dm ^2, more preferably 300~2500μg / dm ^2, more preferably 300~2000μg / dm ^2, the nickel the total coating weight is preferably 100-1000 / dm ^2, more preferably a 100~900μg / dm ^2. If the above conditions are satisfied, the conditions described in this paragraph need not be particularly limited.

Thereafter, a rust prevention treatment is performed as necessary. In the present invention, a preferable antirust treatment is a coating treatment of chromium oxide alone or a mixture coating treatment of chromium oxide and zinc / zinc oxide. Chromium oxide and zinc / zinc oxide mixture coating treatment is zinc or zinc comprising zinc oxide and chromium oxide by electroplating using a plating bath containing zinc salt or zinc oxide and chromate. It is the process which coat | covers the antirust layer of a chromium group mixture.
As the plating bath, typically, at least one kind of dichromate such as K ₂ Cr ₂ O ₇ and Na ₂ Cr ₂ O ₇ and CrO ₃ and a water-soluble zinc salt such as ZnO 2, ZnSO ₄ · 7H are used. A mixed aqueous solution of at least one kind of ₂ O and an alkali hydroxide is used. Typical plating bath compositions and electrolysis conditions are as follows.

The copper foil thus obtained has excellent heat resistance peel strength, oxidation resistance and hydrochloric acid resistance. In addition, a circuit having a pitch of 150 μm or less can be etched with the CuCl ₂ etching solution, and alkali etching can be performed. In addition, penetration into the circuit edge portion during soft etching can be suppressed.
As the soft etching solution, an aqueous solution of H ₂ SO ₄ : 10 wt% and H ₂ O ₂ : 2 wt% can be used. Processing time and temperature can be adjusted arbitrarily.
As the alkaline etching solution, for example, NH ₄ OH: 6 mol / liter, NH ₄ Cl: 5 mol / liter, CuCl ₂ : 2 mol / liter (temperature: 50 ° C.) and the like are known.

The copper foil obtained in all the above steps has a black to gray color. Black to gray is significant in terms of alignment accuracy and high heat absorption rate. For example, circuit boards including rigid boards and flexible boards are mounted with components such as ICs, resistors and capacitors in an automatic process, and chip mounting is performed while reading circuits with sensors. At this time, alignment on the copper foil treated surface may be performed through a film such as Kapton. This also applies to positioning when forming a through hole.
The closer the processing surface is to black, the better the light absorption and the higher the positioning accuracy. Furthermore, when producing a substrate, the copper foil and the film are often cured and bonded together while applying heat. At this time, when heating is performed by using long waves such as far infrared rays and infrared rays, the heating efficiency is improved when the color tone of the treated surface is black.

Finally, if necessary, silane treatment for applying a silane coupling agent to at least the roughened surface on the rust preventive layer is performed mainly for the purpose of improving the adhesive force between the copper foil and the resin substrate. Examples of the silane coupling agent used for the silane treatment include olefin silane, epoxy silane, acrylic silane, amino silane, and mercapto silane, which can be appropriately selected and used. . In addition, when using a liquid crystal polymer as resin, it is preferable to use amino-type silane (silane which has an amino group) as a silane coupling agent. Moreover, it is more preferable to use diaminosilane as a silane coupling agent.
The application method may be any of spraying a silane coupling agent solution by spraying, coating with a coater, dipping, pouring and the like. For example, Japanese Examined Patent Publication No. 60-15654 describes that the adhesion between the copper foil and the resin substrate is improved by performing a chromate treatment on the rough side of the copper foil followed by a silane coupling agent treatment. . Refer to this for details. Thereafter, if necessary, an annealing treatment may be performed for the purpose of improving the ductility of the copper foil.

[Copper foil with carrier]
The copper foil with a carrier which is another embodiment of the present invention has an intermediate layer and an ultrathin copper layer in this order on one side or both sides of the carrier. And the said ultra-thin copper layer is the copper foil for high frequency circuits which is one embodiment of the above-mentioned this invention.

<Career>
Carriers that can be used in the present invention are typically metal foils or resin films, such as copper foil, copper alloy foil, nickel foil, nickel alloy foil, iron foil, iron alloy foil, stainless steel foil, aluminum foil, aluminum. It is provided in the form of alloy foil, insulating resin film (for example, polyimide film, liquid crystal polymer (LCP) film, polyethylene terephthalate (PET) film, polyamide film, polyester film, fluororesin film, etc.).
It is preferable to use a copper foil as a carrier that can be used in the present invention. This is because the copper foil has a high electrical conductivity, so that subsequent formation of an intermediate layer and an ultrathin copper layer becomes easy. The carrier is typically provided in the form of rolled copper foil or electrolytic copper foil. In general, the electrolytic copper foil is produced by electrolytic deposition of copper from a copper sulfate plating bath onto a drum of titanium or stainless steel, and the rolled copper foil is produced by repeating plastic working and heat treatment with a rolling roll. In addition to high-purity copper such as tough pitch copper and oxygen-free copper, the copper foil material is, for example, Sn-containing copper, Ag-containing copper, copper alloy added with Cr, Zr, Mg, etc., and Corson-based added with Ni, Si, etc. Copper alloys such as copper alloys can also be used.

The thickness of the carrier that can be used in the present invention is not particularly limited, but may be appropriately adjusted to a thickness suitable for serving as a carrier, and may be, for example, 5 μm or more. However, if it is too thick, the production cost becomes high, so generally it is preferably 35 μm or less. Accordingly, the thickness of the carrier is typically 12-70 μm, more typically 18-35 μm.
In addition, you may provide a roughening process layer in the surface on the opposite side to the surface in the side which provides the ultra-thin copper layer of a carrier. The said roughening process layer may be provided using a well-known method, and may be provided by the above-mentioned roughening process. Providing a roughened layer on the surface opposite to the surface on which the ultrathin copper layer of the carrier is provided, when laminating the carrier from the surface side having the roughened layer to a support such as a resin substrate, There is an advantage that the carrier and the resin substrate are hardly peeled off.

<Intermediate layer>
An intermediate layer is provided on the carrier. Another layer may be provided between the carrier and the intermediate layer. In the intermediate layer used in the present invention, the ultrathin copper layer is hardly peeled off from the carrier before the copper foil with the carrier is laminated on the insulating substrate, while the ultrathin copper layer is separated from the carrier after the lamination step on the insulating substrate. There is no particular limitation as long as it can be peeled off. For example, the intermediate layer of the copper foil with a carrier of the present invention is Cr, Ni, Co, Fe, Mo, Ti, W, P, Cu, Al, Zn, alloys thereof, hydrates thereof, oxides thereof, One or two or more selected from the group consisting of organic substances may be included. The intermediate layer may be a plurality of layers.
Further, for example, the intermediate layer is a single metal layer composed of one kind of element selected from the element group composed of Cr, Ni, Co, Fe, Mo, Ti, W, P, Cu, Al, Zn from the carrier side. Or forming an alloy layer composed of one or more elements selected from the group consisting of Cr, Ni, Co, Fe, Mo, Ti, W, P, Cu, Al, Zn, A hydrate or oxide of one or more elements selected from the group consisting of Cr, Ni, Co, Fe, Mo, Ti, W, P, Cu, Al, and Zn, or an organic substance Or a single metal layer made of one element selected from the group consisting of Cr, Ni, Co, Fe, Mo, Ti, W, P, Cu, Al, Zn, or Cr, Ni, Co, Fe, Mo, Ti, W, P, Cu, Al It can be constructed by forming an alloy layer made of a selected one or more elements from the configured group of elements in Zn.

When the intermediate layer is provided only on one side, it is preferable to provide a rust preventive layer such as a Ni plating layer on the opposite side of the carrier. When the intermediate layer is provided by chromate treatment, zinc chromate treatment, or plating treatment, it is considered that some of the attached metal such as chromium and zinc may be hydrates or oxides.
Further, for example, the intermediate layer can be configured by laminating nickel, a nickel-phosphorus alloy or a nickel-cobalt alloy, and chromium in this order on a carrier. Since the adhesive strength between nickel and copper is higher than the adhesive strength between chromium and copper, when the ultrathin copper layer is peeled off, it peels at the interface between the ultrathin copper layer and chromium. Further, the nickel of the intermediate layer is expected to have a barrier effect that prevents the copper component from diffusing from the carrier into the ultrathin copper layer. Adhesion amount of nickel in the intermediate layer is preferably 100 [mu] g / dm ² or more 40000μg / dm ² or less, more preferably 100 [mu] g / dm ² or more 4000μg / dm ² or less, more preferably 100 [mu] g / dm ² or more 2500 g / dm ² or less, more Preferably, it is 100 μg / dm ² or more and less than 1000 μg / dm ² , and the amount of chromium deposited on the intermediate layer is preferably 5 μg / dm ² or more and 100 μg / dm ² or less.

<Ultrathin copper layer>
An ultrathin copper layer is provided on the intermediate layer. Another layer may be provided between the intermediate layer and the ultrathin copper layer. The ultra-thin copper layer can be formed by electroplating using an electrolytic bath such as copper sulfate, copper pyrophosphate, copper sulfamate, copper cyanide, etc., and is used in general electrolytic copper foil with high current density. Since a copper foil can be formed, a copper sulfate bath is preferable. The thickness of the ultrathin copper layer is not particularly limited, but is generally thinner than the carrier, for example, 12 μm or less. It is typically 0.5 to 12 μm, more typically 1 to 5 μm, more typically 1.5 to 5 μm, and more typically 2 to 5 μm. In addition, you may provide an ultra-thin copper layer on both surfaces of a carrier.

  In this manner, a carrier-attached copper foil including a carrier, an intermediate layer laminated on the carrier, and an ultrathin copper layer laminated on the intermediate layer is manufactured. The method of using the copper foil with carrier itself is well known to those skilled in the art. For example, the surface of the ultra-thin copper layer is made of paper base phenol resin, paper base epoxy resin, synthetic fiber cloth base epoxy resin, glass cloth / paper composite. Base epoxy resin, glass cloth / glass nonwoven fabric composite base epoxy resin and glass cloth base epoxy resin, polyester film, polyimide film, etc. The printed wiring board can be finally manufactured by etching the ultrathin copper layer adhered to the substrate into a desired conductor pattern.

  Further, the carrier-attached copper foil comprising a carrier and an ultra-thin copper layer laminated on the intermediate layer on the carrier comprises a roughening treatment layer on the ultra-thin copper layer. On the roughening treatment layer, one or more layers selected from the group consisting of a heat-resistant layer, a rust prevention layer, a chromate (treatment) layer, and a silane coupling (treatment) layer may be provided.

[Resin layer]
You may form a resin layer in the surface of the secondary particle layer of the copper foil for high frequency circuits of this invention (The case where the copper foil for high frequency circuits is a very thin copper layer of copper foil with a carrier is included). In addition, the resin layer is formed on the secondary particle layer of the copper foil for high-frequency circuits, Ni, Fe, Cr, Mo, Zn, Ta, Cu, Al, P, W, Mn, Sn, As, and It may be formed on the surface of an alloy layer composed of one or more elements selected from the group consisting of Ti, may be formed on the surface of a chromate layer, may be formed on the surface of a silane coupling layer, You may form in the surface of a Ni-Zn alloy layer. The resin layer is more preferably formed on the outermost surface of the high-frequency circuit copper foil. The carrier-attached copper foil may include a resin layer on the roughening treatment layer, or on the heat-resistant layer, the rust prevention layer, the chromate (treatment) layer, or the silane coupling (treatment) layer. The resin layer may be an insulating resin layer.

  The resin layer may be an adhesive, or an insulating resin layer in a semi-cured state (B stage state) for bonding. The semi-cured state (B stage state) is a state in which there is no sticky feeling even if the surface is touched with a finger, the insulating resin layer can be stacked and stored, and a curing reaction occurs when subjected to heat treatment. Including that.

  The resin layer may contain a thermosetting resin or may be a thermoplastic resin. The resin layer may include a thermoplastic resin. Although the type is not particularly limited, for example, a resin including an epoxy resin, a polyimide resin, a polyfunctional cyanate ester compound, a maleimide compound, a polyvinyl acetal resin, a urethane resin, or the like can be given as a preferable one. .

  The resin layer may be made of any known dielectric such as a known resin, resin curing agent, compound, curing accelerator, dielectric (dielectric including an inorganic compound and / or organic compound, dielectric including a metal oxide). May be included), a reaction catalyst, a crosslinking agent, a polymer, a prepreg, a skeleton material, and the like. The resin layer may be, for example, International Publication No. WO2008 / 004399, International Publication No. WO2008 / 053878, International Publication No. WO2009 / 084533, JP-A-11-5828, JP-A-11-140281, Patent 3184485, International Publication No. WO 97/02728, Japanese Patent No. 3676375, Japanese Patent Laid-Open No. 2000-43188, Japanese Patent No. 3612594, Japanese Patent Laid-Open No. 2002-179772, Japanese Patent Laid-Open No. 2002-359444, Japanese Patent Laid-Open No. 2003-302068, Japanese Patent No. 3992225, Japanese Patent Laid-Open No. 2003 No. 249739, Japanese Patent No. 4136509, Japanese Patent Application Laid-Open No. 2004-82687, Japanese Patent No. 4025177, Japanese Patent Application Laid-Open No. 2004-349654, Japanese Patent No. 4286060, Japanese Patent Application Laid-Open No. 2005-262506, Japanese Patent No. 4570070, Japanese Patent Application Laid-Open No. No. 5-53218, Japanese Patent No. 3949676, Japanese Patent No. 4178415, International Publication No. WO2004 / 005588, Japanese Patent Application Laid-Open No. 2006-257153, Japanese Patent Application Laid-Open No. 2007-326923, Japanese Patent Application Laid-Open No. 2008-11169, and Japanese Patent No. 5024930. No. WO 2006/028207, Japanese Patent No. 4828427, JP 2009-67029, International Publication No. WO 2006/134868, Japanese Patent No. 5046927, JP 2009-173017, International Publication No. WO 2007/105635, Patent No. 5180815, International Publication Number WO2008 / 114858, International Publication Number WO2009 / 008471, Japanese Patent Application Laid-Open No. 2011-14727, International Publication Number WO2009 / 001850, International Publication Number WO2009 / 145179, International Publication Number Nos. WO2011 / 068157, JP-A-2013-19056 (resins, resin curing agents, compounds, curing accelerators, dielectrics, reaction catalysts, crosslinking agents, polymers, prepregs, skeletal materials, etc.) and / or You may form using the formation method and formation apparatus of a resin layer.

  For example, these resins are dissolved in a solvent such as methyl ethyl ketone (MEK) and toluene to form a resin solution, which is formed on the copper foil or ultrathin copper layer, or the heat-resistant layer, the rust-proof layer, or the chromate film layer, Or it apply | coats on the said silane coupling agent layer, for example by the roll coater method etc., Then, it heat-drys as needed, a solvent is removed, and it will be in a B stage state. For example, a hot air drying furnace may be used for drying, and the drying temperature may be 100 to 250 ° C, preferably 130 to 200 ° C.

The high-frequency circuit copper foil (resin-equipped high-frequency circuit copper foil) provided with the resin layer is obtained by superposing the resin layer on a base material and then thermocompressing the entire resin layer to thermally cure the resin layer. And a predetermined wiring pattern is used.
The carrier-attached copper foil with the resin layer (copper foil with resin carrier) is laminated with the resin layer on the base material, and the entire resin layer is thermocompression-bonded to thermally cure the resin layer. The ultrathin copper layer is peeled off to expose it (which is naturally the surface on the intermediate layer side of the ultrathin copper layer), and a predetermined wiring pattern is formed thereon.

  Use of this resin-coated high-frequency circuit copper foil or resin-coated copper foil with carrier can reduce the number of prepreg materials used in the production of a multilayer printed wiring board. In addition, the copper-clad laminate can be manufactured even if the resin layer is made thick enough to ensure interlayer insulation or no prepreg material is used. At this time, the surface smoothness can be further improved by undercoating the surface of the substrate with an insulating resin.

  In addition, when the prepreg material is not used, the material cost of the prepreg material is saved and the laminating process is simplified, which is economically advantageous. Moreover, the multilayer printed wiring board manufactured by the thickness of the prepreg material is used. The thickness is reduced, and there is an advantage that an extremely thin multilayer printed wiring board in which the thickness of one layer is 100 μm or less can be manufactured.

  The thickness of the resin layer is preferably 0.1 to 80 μm.

  When the thickness of the resin layer is less than 0.1 μm, the adhesive strength is reduced, and when the copper foil with a carrier with the resin is laminated on the base material provided with the inner layer material without interposing the prepreg material, the circuit of the inner layer material It may be difficult to ensure interlayer insulation between the two.

  On the other hand, if the thickness of the resin layer is greater than 80 μm, it is difficult to form a resin layer having a desired thickness in a single coating process, which is economically disadvantageous because of extra material costs and man-hours. Furthermore, since the formed resin layer is inferior in flexibility, cracks are likely to occur during handling, and excessive resin flow occurs during thermocompression bonding with the inner layer material, making smooth lamination difficult. There is.

  In addition, as another product form of the copper foil with a carrier with a resin, a resin layer is formed on the ultrathin copper layer, or on the heat-resistant layer, the rust-proof layer, the chromate layer, or the silane coupling layer. After coating and making it into a semi-cured state, the carrier can then be peeled off and manufactured in the form of a resin-coated copper foil (ultra-thin copper layer) in which no carrier is present.

  Here, some examples of the manufacturing process of the printed wiring board using the copper foil with a carrier which concerns on this invention are shown below.

  In one embodiment of a method for producing a printed wiring board according to the present invention, a step of preparing a copper foil with a carrier and an insulating substrate according to the present invention, a step of laminating the copper foil with a carrier and an insulating substrate, and with the carrier After laminating the copper foil and the insulating substrate so that the ultrathin copper layer side faces the insulating substrate, a copper-clad laminate is formed through a step of peeling the carrier of the copper foil with carrier, and then a semi-additive method, a modified semi-conductor A step of forming a circuit by any one of an additive method, a partial additive method, and a subtractive method. It is also possible for the insulating substrate to contain an inner layer circuit.

  In the present invention, the semi-additive method is a method in which a thin electroless plating is performed on an insulating substrate or a copper foil seed layer, a plating resist pattern is formed, and then a conductive pattern is formed by electroplating, removing the plating resist, and etching. Refers to a method comprising forming.

  In the present invention, the modified semi-additive method is a method in which a metal foil is laminated on an insulating layer, a non-circuit forming part is protected by a plating resist, and a copper is thickened in the circuit forming part by electrolytic plating, and then the resist is removed. The method further includes forming a circuit on the insulating layer by removing the metal foil other than the circuit forming portion by (flash) etching.

  In the present invention, the partial additive method means that a catalyst circuit is formed on a substrate provided with a conductor layer, and if necessary, a substrate provided with holes for through holes or via holes, and etched to form a conductor circuit. A method of manufacturing a printed wiring board by a method including, after providing a solder resist or a plating resist as necessary, thickening the through hole or via hole by electroless plating on the conductor circuit Point to.

  In the present invention, the subtractive method refers to a method including selectively removing unnecessary portions of a copper foil on a copper clad laminate by etching or the like to form a conductor pattern.

  In the present invention, known methods can be used as a semi-additive method, a modified semi-additive method, a partly additive method, and a subtractive method. In the present invention, through holes or / and blind vias may be provided in an insulating substrate or the like in the above-described semi-additive method, modified semi-additive method, partly additive method, and subtractive method.

Here, the specific example of the manufacturing method of the printed wiring board using the copper foil with a carrier of this invention is demonstrated in detail using drawing.
First, as shown to FIG. 5-A, the copper foil with a carrier (1st layer) which has the ultra-thin copper layer in which the roughening process layer was formed on the surface is prepared.
Next, as shown in FIG. 5B, a resist is applied on the roughened layer of the ultrathin copper layer, exposed and developed, and the resist is etched into a predetermined shape.
Next, as shown in FIG. 5C, after forming a plating for a circuit, the resist is removed to form a circuit plating having a predetermined shape.
Next, as shown in FIG. 6-D, an embedded resin is provided on the ultrathin copper layer so as to cover the circuit plating (so that the circuit plating is buried), and then the resin layer is laminated, followed by another carrier attachment. A copper foil (second layer) is bonded from the ultrathin copper layer side.
Next, as shown to FIG. 6-E, a carrier is peeled from the copper foil with a carrier of the 2nd layer.
Next, as shown in FIG. 6-F, laser drilling is performed at a predetermined position of the resin layer to expose the circuit plating and form a blind via.
Next, as shown in FIG. 7-G, copper is embedded in the blind via to form a via fill.
Next, as shown in FIG. 7H, circuit plating is formed on the via fill as shown in FIGS. 5-B and 5-C.
Next, as shown to FIG. 7-I, a carrier is peeled from the copper foil with a carrier of the 1st layer.
Next, as shown in FIG. 8J, the ultrathin copper layers on both surfaces are removed by flash etching to expose the surface of the circuit plating in the resin layer.
Next, as shown in FIG. 8K, bumps are formed on the circuit plating in the resin layer, and copper pillars are formed on the solder. Thus, the printed wiring board using the copper foil with a carrier of this invention is produced.

  As the another copper foil with a carrier (second layer), the copper foil with a carrier of the present invention may be used, a conventional copper foil with a carrier may be used, and a normal copper foil may be further used. Further, one or more circuits may be formed on the second-layer circuit shown in FIG. 7-H, and these circuits may be formed by a semi-additive method, a subtractive method, a partial additive method, or a modified semi-conductor method. You may carry out by any method of an additive method.

  According to the printed wiring board manufacturing method as described above, since the circuit plating is embedded in the resin layer, for example, when removing the ultrathin copper layer by flash etching as shown in FIG. In addition, the circuit plating is protected by the resin layer and the shape thereof is maintained, thereby facilitating the formation of a fine circuit. Further, since the circuit plating is protected by the resin layer, the migration resistance is improved, and the continuity of the circuit wiring is satisfactorily suppressed. For this reason, formation of a fine circuit becomes easy. Also, as shown in FIGS. 8J and 8K, when the ultrathin copper layer is removed by flash etching, the exposed surface of the circuit plating is recessed from the resin layer, so that bumps are formed on the circuit plating. In addition, copper pillars can be easily formed thereon, and the production efficiency is improved.

  A known resin or prepreg can be used as the embedding resin (resin). For example, a prepreg that is a glass cloth impregnated with BT (bismaleimide triazine) resin or BT resin, an ABF film or ABF manufactured by Ajinomoto Fine Techno Co., Ltd. can be used. Moreover, the resin layer and / or resin and / or prepreg as described in this specification can be used for the embedding resin (resin).

  Moreover, the copper foil with a carrier used for the first layer may have a substrate or a resin layer on the surface of the copper foil with a carrier. By having the said board | substrate or resin layer, the copper foil with a carrier used for the first layer is supported, and since it becomes difficult to wrinkle, there exists an advantage that productivity improves. As the substrate or resin layer, any substrate or resin layer can be used as long as it has an effect of supporting the copper foil with carrier used in the first layer. For example, as the substrate or resin layer, the carrier, prepreg, resin layer and known carrier, prepreg, resin layer, metal plate, metal foil, inorganic compound plate, inorganic compound foil, organic compound plate described in the present specification, Organic compound foils can be used.

Hereinafter, description will be made based on Examples and Comparative Examples. In addition, a present Example is an example to the last, and is not restrict | limited only to this example. That is, other aspects or modifications included in the present invention are included. In addition, 18 μm of standard rolled copper foil TPC (tough pitch copper standardized in JIS H3100 C1100) was used for the raw foils of Examples 1 to 7, 12 to 16, and Comparative Examples 1 to 6 below.
Moreover, the copper foil with a carrier manufactured with the following method was used for Examples 8-11 original foil.
In Examples 8 to 10, an electrolytic copper foil having a thickness of 18 μm (JTC foil made by JX Nippon Mining & Metals) was prepared as a carrier, and in Example 11, the above-described standard rolled copper foil TPC having a thickness of 18 μm was prepared as a carrier. did. Under the following conditions, an intermediate layer was formed on the surface of the carrier, and an ultrathin copper layer was formed on the surface of the intermediate layer. When the carrier was an electrolytic copper foil, an intermediate layer was formed on the glossy surface (S surface).

Example 8
<Intermediate layer>
(1) Ni layer (Ni plating)
An Ni layer having an adhesion amount of 1000 μg / dm ² was formed on the carrier by electroplating on a roll-to-roll type continuous plating line under the following conditions. Specific plating conditions are described below.
Nickel sulfate: 270-280 g / L
Nickel chloride: 35 to 45 g / L
Nickel acetate: 10-20g / L
Boric acid: 30-40 g / L
Brightener: Saccharin, butynediol, etc. Sodium dodecyl sulfate: 55-75 ppm
pH: 4-6
Bath temperature: 55-65 ° C
Current density: 10 A / dm ²
(2) Cr layer (electrolytic chromate treatment)
Next, after the surface of the Ni layer formed in (1) is washed with water and pickled, a Cr layer having an adhesion amount of 11 μg / dm ² is continuously formed on the Ni layer on a roll-to-roll-type continuous plating line. It was made to adhere by carrying out the electrolytic chromate process on the following conditions.
Potassium dichromate 1-10g / L, zinc 0g / L
pH: 7-10
Liquid temperature: 40-60 degreeC
Current density: 2 A / dm ²
<Ultrathin copper layer>
Next, after the surface of the Cr layer formed in (2) is washed with water and pickled, an ultrathin copper layer having a thickness of 1.5 μm is continuously formed on the Cr layer on a roll-to-roll-type continuous plating line. It formed by electroplating on condition of the following, and produced copper foil with a carrier.
Copper concentration: 90-110 g / L
Sulfuric acid concentration: 90-110 g / L
Chloride ion concentration: 50-90ppm
Leveling agent 1 (bis (3sulfopropyl) disulfide): 10 to 30 ppm
Leveling agent 2 (amine compound): 10 to 30 ppm
In addition, the following amine compound was used as the leveling agent 2.
(In the above chemical formula, R ₁ and R ₂ are selected from the group consisting of a hydroxyalkyl group, an ether group, an aryl group, an aromatic substituted alkyl group, an unsaturated hydrocarbon group, and an alkyl group.)
Electrolyte temperature: 50-80 ° C
Current density: 100 A / dm ²
Electrolyte linear velocity: 1.5-5 m / sec

Example 9
<Intermediate layer>
(1) Ni-Mo layer (nickel molybdenum alloy plating)
A Ni—Mo layer having an adhesion amount of 3000 μg / dm ² was formed on the carrier by electroplating on a roll-to-roll continuous plating line under the following conditions. Specific plating conditions are described below.
(Liquid composition) Ni sulfate hexahydrate: 50 g / dm ³ , sodium molybdate dihydrate: 60 g / dm ³ , sodium citrate: 90 g / dm ³
(Liquid temperature) 30 ° C
(Current density) 1 to 4 A / dm ²
(Energization time) 3 to 25 seconds <Ultra-thin copper layer>
An ultrathin copper layer was formed on the Ni—Mo layer formed in (1). An ultrathin copper layer was formed under the same conditions as in Example 8 except that the thickness of the ultrathin copper layer was 2 μm.

Example 10
<Intermediate layer>
(1) Ni layer (Ni plating)
A Ni layer was formed under the same conditions as in Example 8.
(2) Organic layer (Organic layer formation treatment)
Next, the surface of the Ni layer formed in (1) is washed with water and pickled, and subsequently contains carboxybenzotriazole (CBTA) at a concentration of 1 to 30 g / L with respect to the Ni layer surface under the following conditions. An organic layer was formed by spraying an aqueous solution of 40 ° C. and pH 5 after 20 to 120 seconds of showering.
<Ultrathin copper layer>
An ultrathin copper layer was formed on the organic layer formed in (2). An ultrathin copper layer was formed under the same conditions as in Example 8 except that the thickness of the ultrathin copper layer was 3 μm.

Example 11
<Intermediate layer>
(1) Co-Mo layer (cobalt molybdenum alloy plating)
A Co—Mo layer having an adhesion amount of 4000 μg / dm ² was formed on the carrier by electroplating on a roll-to-roll type continuous plating line under the following conditions. Specific plating conditions are described below.
(Liquid composition) Co sulfate 50 g / dm ³ , sodium molybdate dihydrate: 60 g / dm ³ , sodium citrate: 90 g / dm ³
(Liquid temperature) 30 ° C
(Current density) 1 to 4 A / dm ²
(Energization time) 3 to 25 seconds <Ultra-thin copper layer>
An ultrathin copper layer was formed on the Co—Mo layer formed in (1). An ultrathin copper layer was formed under the same conditions as in Example 8 except that the thickness of the ultrathin copper layer was changed to 5 μm.

(Examples 1 to 16)
A primary particle layer (Cu) and a secondary particle are formed on the surface of the ultrathin copper layer (Examples 8 to 11) of the rolled copper foil (Examples 1 to 7 and 12 to 16) or the copper foil with carrier in the conditions shown below. A particle layer (copper-cobalt-nickel alloy plating) was formed.
The bath composition and plating conditions used are as follows.

[Bath composition and plating conditions]
(A) Formation of primary particle layer (Cu plating)
Liquid composition: Copper 15g / L, sulfuric acid 75g / L
Liquid temperature: 25-30 degreeC
Current density: 1 to 70 A / dm ²
Coulomb amount: ^{2 to} 90 As / dm ²
(B) Formation of secondary particle layer (Cu—Co—Ni alloy plating)
Liquid composition: Copper 15g / L, nickel 8g / L, cobalt 8g / L
pH: 2
Liquid temperature: 40 ° C
Current density: 10 to 50 A / dm ²
Coulomb amount: 10-80 As / dm ²

  The conditions of the formation of the primary particle layer (Cu plating) and the formation of the secondary particle layer (Cu—Co—Ni alloy plating) are adjusted, and the color tone is gray or black, and the color difference system described in JISZ8730 is rough. The color difference Δa * value with respect to white when the color difference on the surface to be processed was measured was 4.0 or less, and the color difference Δb * value was 3.5 or less. The color difference was measured using the previously described HunterLab МiniScan XE Plus color difference meter.

(Comparative Examples 1-6)
In the comparative example, the bath composition and plating conditions used are as follows.
[Bath composition and plating conditions]
(A) Formation of primary particle layer (copper plating)
Liquid composition: Copper 15g / L, sulfuric acid 75g / L
Liquid temperature: 25-35 degreeC
Current density: 1 to 70 A / dm ²
Coulomb amount: ^{2 to} 90 As / dm ²
(B) Formation of secondary particle layer (Cu—Co—Ni alloy plating conditions)
Liquid composition: Copper 15g / L, nickel 8g / L, cobalt 8g / L
pH: 2
Liquid temperature: 40 ° C
Current density: 20 to 50 A / dm ²
Coulomb amount: 30-80 As / dm ²

<Surface treatment layer other than primary particle layer and secondary particle layer>
After the formation of the primary particle layer and the secondary particle layer, a surface treatment layer was performed under the following conditions for some examples and comparative examples.
(Examples 3, 4, 9, 10 and Comparative Examples 1 to 5)
Co-Ni plating: Cobalt-nickel alloy plating Liquid composition: Nickel 5-20 g / L, cobalt 1-8 g / L
pH: 2-3
Liquid temperature: 40-60 degreeC
Current density: 5 to 20 A / dm ²
Coulomb amount: 10-20 As / dm ²

(Examples 5 and 11)
Ni-Zn plating: Nickel zinc alloy plating Liquid composition: Nickel 2-30 g / L, zinc 2-30 g / L
pH: 3-4
Liquid temperature: 30-50 degreeC
Current density: 1 to ^{2 A} / dm ²
Coulomb amount: 1-2 As / dm ²
In Examples 5 and 11, after Ni-Zn plating, electrolytic chromate treatment and silane coupling treatment using diaminosilane were performed.

(Example 7)
Ni-Cu plating: Nickel copper alloy plating Liquid composition: Nickel 2-30 g / L, Copper 2-30 g / L
pH: 3-4
Liquid temperature: 30-50 degreeC
Current density: 1 to ^{2 A} / dm ²
Coulomb amount: 1-2 As / dm ²

(Example 12)
Ni-Mo plating: nickel molybdenum alloy plating Liquid composition: Ni sulfate sulfate hexahydrate: 45-55 g / dm ³ , sodium molybdate dihydrate: 50-70 g / dm ³ , sodium citrate: 80-100 g / dm ³
Liquid temperature: 20-40 degreeC
Current density: 1 to 4 A / dm ²
Coulomb amount: 1-2 As / dm ²
In addition, about Example 12, the electrolytic chromate process was performed after Ni-Mo plating.

(Example 13)
Ni-Sn plating: Nickel tin alloy plating Liquid composition: Nickel 2-30 g / L, tin 2-30 g / L
pH: 1.5-4.5
Liquid temperature: 30-50 degreeC
Current density: 1 to ^{2 A} / dm ²
Coulomb amount: 1-2 As / dm ²
In addition, about Example 13, the silane coupling process using diaminosilane was performed after Ni-Sn plating.

(Example 14)
Ni-P plating: Nickel phosphorus alloy plating Liquid composition: Nickel 30-70 g / L, Phosphorus 0.2-1.2 g / L
pH: 1.5-2.5
Liquid temperature: 30-40 degreeC
Current density: 1 to ^{2 A} / dm ²
Coulomb amount: 1-2 As / dm ²

(Example 15)
-Ni-W plating: Nickel tungsten alloy plating Liquid composition: Nickel 2-30 g / L, W 0.01-5 g / L
pH: 3-4
Liquid temperature: 30-50 degreeC
Current density: 1 to ^{2 A} / dm ²
Coulomb amount: 1-2 As / dm ²
In Example 15, after Ni-W plating, electrolytic chromate treatment and silane coupling treatment using diaminosilane were performed.

(Example 16)
Ni-Cr plating: nickel chromium alloy plating A nickel chromium alloy plating layer was formed using a sputtering target having a composition of Ni: 80 mass% and Cr: 20 mass%.
Target: Ni: 80 mass%, Cr: 20 mass%
Equipment: Sputtering equipment manufactured by ULVAC, Inc. Output: DC50W
Argon pressure: 0.2 Pa

Average particle size of primary particles, average particle size of secondary particles when primary particle layer (Cu plating) and secondary particle layer (Cu-Co-Ni alloy plating) on copper foil formed by the above example are formed. Table 1 shows the results of measuring the color differences Δa *, Δb *, and ΔL * from white when the diameter, powder fall, peel strength, heat resistance, and color difference of the roughened surface were measured. Here, the measured “roughening surface” was the outermost surface on the side where the primary particle layer and the secondary particle layer were formed. In addition, on the secondary particle layer, a surface treatment layer other than the primary particle layer and the secondary particle layer, such as Co-Ni plating, Ni-Zn plating, chromate layer, silane coupling layer, is formed. The surface of the outermost layer of these layers was measured as a roughened surface (that is, the surface on the side where the primary particle layer and the secondary particle layer existed after all the surface treatment layers of the copper foil were formed). It was measured).
The average particle size of the primary and secondary particles on the roughened surface was obtained by performing particle observation and photography at a magnification of 30000 times using S4700 (scanning electron microscope) manufactured by Hitachi High-Technologies Corporation. The particle diameter was measured for each primary particle and secondary particle based on the photograph. And the arithmetic average value of the particle diameter of each obtained primary particle and secondary particle was made into the value of the average particle diameter of a primary particle, and the average particle diameter of a secondary particle. In addition, when a straight line was drawn on the particle | grains of the scanning electron micrograph, the length of the particle | grain of the part with the longest length of the straight line crossing particle | grains was made into the particle size of the particle | grain. The size of the measurement visual field was 13.44 μm ² (= 4.2 μm × 3.2 μm) per visual field, and measurement was performed for one visual field. In addition, when observed with a scanning electron micrograph, particles that appear to overlap and exist on the copper foil side (lower side), and particles that do not overlap are primary particles, and other particles that appear to overlap. Particles existing on the particles were determined as secondary particles. The powder-off characteristics are based on the appearance of the tape discoloring due to the falling roughened particles adhering to the adhesive surface of the tape when a transparent mending tape is applied on the roughened surface of the copper foil. Evaluated. That is, when there was no or slight discoloration of the tape, the powder was OK, and when the tape was gray, the powder was NG. For normal peel strength, a copper foil roughened surface and the resin substrate shown in Table 1 are bonded together by hot pressing to produce a copper clad laminate, and a 10 mm circuit is produced using a general copper chloride circuit etchant. Then, the 10 mm circuit copper foil was peeled from the substrate, and the normal peel strength was measured while pulling in the 90 ° direction.

(Measurement of transmission loss)
About each sample of 18 micrometers thickness, it bonded together with the resin substrate (LCP: liquid crystal polymer resin (Vecstar CTZ-50micrometer made by Kuraray Co., Ltd.), polyimide: Kaneka thickness 50 micrometers, fluororesin thickness 50 micrometers: DuPont) about each sample of 18 micrometers. Thereafter, a microstrip line was formed by etching so that the characteristic impedance was 50Ω, and a transmission coefficient was measured using a network analyzer HP8720C manufactured by HP, and transmission loss at a frequency of 20 GHz and a frequency of 40 GHz was obtained. In addition, about Examples 8-11, after bonding the surface by the side of the ultra-thin copper layer of copper foil with a carrier with the resin substrate of Table 1, after peeling a carrier, copper plating was carried out, and ultra-thin After the total thickness of the copper layer and the copper plating was 18 μm, the transmission loss was measured as described above. As an evaluation of transmission loss at a frequency of 20 GHz, 未 満 less than 3.7 dB / 10 cm, ◎ 3.7 dB / 10 cm or more and less than 4.1 dB / 10 cm, 、 ４ 4.1 dB / 10 cm or more and less than 5.0 dB / 10 cm, △, 5.0 dB / 10 cm or more was defined as x.

Moreover, the same result is shown in Table 1 as a comparative example.
In addition, in the example where the current condition and two coulomb amounts are described in the primary particle current condition column in Table 1, after performing plating under the conditions described on the left, further plating is performed under the conditions described on the right. Means that For example, in the primary particle current condition column of Example 1, “(65 A / dm ² , 80 As / dm ² ) + (20 A / dm ² , 30 As / dm ² )” is described. After plating with a current density of 65 A / dm ² and a coulomb amount of 80 As / dm ² , plating was further performed with a current density of forming primary particles of 20 A / dm ² and a coulomb amount of 30 As / dm ² . It shows that.

As is apparent from Table 1, the results of the examples of the present invention are as follows.
In Example 1, the current density for forming the primary particles is 65 A / dm ² and 20 A / dm ² , and the coulomb amounts are 80 As / dm ² and 30 As / dm ^2. This is a case where 28 A / dm ² is used and the coulomb amount is 20 As / dm ² .
In addition, although the current density and the amount of Coulomb which form primary particles are two steps, when forming primary particles normally, two steps of electroplating are required. That is, the plating conditions for the first stage nuclear particle formation and the electroplating for the growth of the second stage nuclear particles.
The first plating condition is an electroplating condition for forming the first stage nucleation particles, and the next plating condition is an electroplating condition for growing the second stage nucleation particles. The same applies to the following examples and comparative examples, and the description is omitted.
As a result, the average particle diameter of the primary particles was 0.45 μm, the average particle diameter of the secondary particles was 0.30 μm, and the surface color after the formation of the particles became gray. The color difference Δa * from the white when the color difference of the roughened surface was measured was 1.42, Δb * was 1.09, and ΔL * was −49.18, which satisfied the conditions of the present invention. As a result, there was little powder falling and the normal peel strength was as high as 1.16 kg / cm, and the heat resistance deterioration rate (the peel strength after heating at 180 ° C. for 48 hours after the normal peel measurement was measured and the difference was taken as the deterioration rate) Was less than 30%.
In addition, the heat-resistant deterioration rate was calculated | required with the following formula | equation.
Thermal degradation rate (%) = (Normal peel strength (kg / cm) −Peel strength after heating at 180 ° C. for 48 hours) / Normal peel strength (kg / cm) × 100

In Example 2, the current density for forming the primary particles is 65 A / dm ² and 2 A / dm ² , and the coulomb amounts are 80 As / dm ² and 4 As / dm ^2. This is a case where 25 A / dm ² is used and the coulomb amount is 15 As / dm ² .
As a result, the average particle diameter of the primary particles was 0.40 μm, the average particle diameter of the secondary particles was 0.15 μm, and the color of the surface after forming the particles became gray. When the color difference of the roughened surface was measured, the color difference Δa * from white was 3.58, Δb * was 1.98, and ΔL * was −48.05, which satisfied the conditions of the present invention. As a result, there was no powder falling and the normal peel strength was as high as 1.08 kg / cm, and the heat resistance deterioration rate (the peel strength after heating at 180 ° C. for 48 hours after the normal peel measurement was measured and the difference was taken as the deterioration rate) Was less than 30%.

Example 3 is a case where the current density for forming the primary particles is 60 A / dm ² and 10 A / dm ² , and the coulomb amounts are 80 As / dm ² and 20 As / dm ^2. This is a case where 25 A / dm ² and the coulomb amount are 30 As / dm ² .
As a result, the average particle diameter of the primary particles was 0.30 μm, the average particle diameter of the secondary particles was 0.25 μm, and the color of the surface after forming the particles became gray. When the color difference of the roughened surface was measured, the color difference Δa * from white was 2.73, Δb * was 1.97, and ΔL * was −40.63, which satisfied the conditions of the present invention. There was no powder fall. The normal peel strength is as high as 0.92 kg / cm, and the heat resistance deterioration rate (the peel strength after heating at 180 ° C. for 48 hours after the normal peel measurement is taken as the deterioration rate) is as small as 30% or less. It had the characteristics.

In Example 4, the current density for forming the primary particles is 55 A / dm ² and 1 A / dm ² , and the coulomb amounts are 75 As / dm ² and 5 As / dm ^2. This is a case where 25 A / dm ² and the coulomb amount are 30 As / dm ² .
As a result, the average particle diameter of the primary particles was 0.35 μm, the average particle diameter of the secondary particles was 0.25 μm, and the color of the surface after forming the particles became gray. The color difference Δa * from the white when the color difference of the roughened surface was measured was 2.22, Δb * was 1.53, and ΔL * was −48.98, which satisfied the conditions of the present invention. No powder fall off, normal peel strength is as high as 0.94 kg / cm, heat resistance deterioration rate (measured peel strength after heating at 180 ° C. for 48 hours after normal peel measurement, the difference was taken as the deterioration rate) 30% It had the following small features.

In Example 5, the current density for forming the primary particles is 50 A / dm ² and 5 A / dm ² , and the coulomb amounts are 70 As / dm ² and 10 As / dm ^2. This is a case where 25 A / dm ² and the coulomb amount are 30 As / dm ² . In addition, a Ni—Zn plating treatment layer was provided as a heat-resistant treatment layer on the secondary particle layer, and then an electrolytic chromate treatment and a silane coupling treatment were performed.
As a result, the average particle diameter of the primary particles was 0.30 μm, the average particle diameter of the secondary particles was 0.25 μm, and the color of the surface after forming the particles became gray. When the color difference of the roughened surface was measured, the color difference Δa * from white was 3.73, Δb * was 2.4, and ΔL * was −47.31, which satisfied the conditions of the present invention. No powder fall off, normal peel strength is as high as 0.94 kg / cm, heat resistance deterioration rate (measured peel strength after heating at 180 ° C. for 48 hours after normal peel measurement, the difference was taken as the deterioration rate) 30% It had the following small features.

Example 6 is a case where the current density for forming the primary particles is 50 A / dm ² and 2 A / dm ² and the coulomb amounts are 70 As / dm ² and 3 As / dm ^2. This is a case where 15 A / dm ² is set and the coulomb amount is 30 As / dm ² .
As a result, the average particle size of the primary particles was 0.25 μm, and the secondary particles were almost covered (normal) in a plated state (particle size is less than 0.1 μm), and the surface color after forming the particles was gray. The color difference Δa * from the white when the color difference of the roughened surface was measured was 2.75, Δb * was 3.38, and ΔL * was −33.48, which satisfied the conditions of the present invention. No peeling off, normal peel strength as high as 0.81 kg / cm, heat resistance deterioration rate (measured peel strength after heating at 180 ° C. for 48 hours after normal peel measurement, and the difference was taken as the deterioration rate) 30% It had the following small features.

Example 7 is a case where the current density for forming primary particles is 60 A / dm ² and 15 A / dm ² , and the coulomb amounts are 80 As / dm ² and 20 As / dm ^2. Secondary particles (secondary particle layer) After forming a current density of 20 A / dm ² and a coulomb amount of 60 As / dm ² and performing plating (normal plating), the current density is further set to 20 A / dm ² and the particles are formed with a coulomb amount of 20 As / dm ^2. This is the case.
As a result, the primary particles have an average particle size of 0.35 μm, the secondary particles are covered (normal) in a plated state (particle size is less than 0.1 μm), and the average particle size is 0.15 μm. The surface color of became gray. The color difference Δa * from white when the color difference of the roughened surface was measured was 2.09, Δb * was 2.05, and ΔL * was −38.54, which satisfied the conditions of the present invention. No powder fall off, normal peel strength is as high as 0.83 kg / cm, heat resistance deterioration rate (measured peel strength after heating at 180 ° C. for 48 hours after measurement of normal peel, and the difference was taken as the deterioration rate) 30% It had the following small features.

Example 8 is a case where the current density for forming the primary particles is 65 A / dm ² and 2 A / dm ² and the coulomb amounts are 80 As / dm ² and 4 As / dm ^2. This is a case where 25 A / dm ² is used and the coulomb amount is 15 As / dm ² .
As a result, the average particle diameter of the primary particles was 0.41 μm, the average particle diameter of the secondary particles was 0.16 μm, and the color of the surface after forming the particles became gray. The color difference Δa * from white when the color difference of the roughened surface was measured was 3.62, Δb * was 2.02, and ΔL * was −48.51, which satisfied the conditions of the present invention. No powder fall off, normal peel strength is as high as 1.09 kg / cm, heat resistance deterioration rate (measurement of peel strength after heating at 180 ° C. for 48 hours after measurement of normal peel and the difference was taken as the deterioration rate) is 30% It had the following small features.

In Example 9, the current density for forming the primary particles is 60 A / dm ² and 10 A / dm ² , and the coulomb amounts are 80 As / dm ² and 20 As / dm ^2. This is a case where 25 A / dm ² and the coulomb amount are 30 As / dm ² .
As a result, the average particle diameter of the primary particles was 0.31 μm, the average particle diameter of the secondary particles was 0.25 μm, and the color of the surface after forming the particles became gray. When the color difference of the roughened surface was measured, the color difference Δa * from white was 2.72, Δb * was 1.98, and ΔL * was −40.67, which satisfied the conditions of the present invention. No powder fall off, normal peel strength is as high as 0.93 kg / cm, heat resistance deterioration rate (measurement of peel strength after heating at 180 ° C. for 48 hours after measurement of normal peel and the difference was taken as the deterioration rate) is 30% It had the following small features.

In Example 10, the current density for forming the primary particles is 55 A / dm ² and 1 A / dm ² , and the coulomb amounts are 75 As / dm ² and 5 As / dm ^2. This is a case where 25 A / dm ² and the coulomb amount are 30 As / dm ² .
As a result, the average particle diameter of the primary particles was 0.35 μm, the average particle diameter of the secondary particles was 0.26 μm, and the color of the surface after forming the particles was gray. The color difference Δa * from the white when the color difference of the roughened surface was measured was 2.22, Δb * was 1.54, and ΔL * was −48.92, which satisfied the conditions of the present invention. No powder fall off, normal peel strength is as high as 0.95 kg / cm, heat resistance deterioration rate (measured peel strength after heating at 180 ° C. for 48 hours after normal peel measurement, and the difference was taken as the deterioration rate) 30% It had the following small features.

In Example 11, the current density for forming the primary particles is 50 A / dm ² and 5 A / dm ² , and the coulomb amounts are 70 As / dm ² and 10 As / dm ^2. This is a case where 25 A / dm ² and the coulomb amount are 30 As / dm ² .
As a result, the average particle diameter of the primary particles was 0.30 μm, the average particle diameter of the secondary particles was 0.25 μm, and the color of the surface after forming the particles became gray. The color difference Δa * from white when the color difference of the roughened surface was measured was 3.72, Δb * was 2.39, and ΔL * was −47.33, which satisfied the conditions of the present invention. No powder fall off, normal peel strength is as high as 0.94 kg / cm, heat resistance deterioration rate (measured peel strength after heating at 180 ° C. for 48 hours after normal peel measurement, the difference was taken as the deterioration rate) 30% It had the following small features.

In Example 12, the current density for forming the primary particles is 60 A / dm ² and 10 A / dm ² , and the coulomb amounts are 80 As / dm ² and 20 As / dm ^2. This is a case where 25 A / dm ² and the coulomb amount are 30 As / dm ² .
As a result, the average particle diameter of the primary particles was 0.30 μm, the average particle diameter of the secondary particles was 0.25 μm, and the color of the surface after forming the particles became gray. The color difference Δa * from the white when the color difference of the roughened surface was measured was 2.74, Δb * was 1.98, and ΔL * was −40.67, which satisfied the conditions of the present invention. No powder fall off, normal peel strength is as high as 0.93 kg / cm, heat resistance deterioration rate (measurement of peel strength after heating at 180 ° C. for 48 hours after measurement of normal peel and the difference was taken as the deterioration rate) is 30% It had the following small features.

Example 13 is a case where the current density for forming primary particles is 60 A / dm ² and 10 A / dm ² , and the coulomb amounts are 80 As / dm ² and 20 As / dm ^2. This is a case where 25 A / dm ² and the coulomb amount are 30 As / dm ² .
As a result, the average particle diameter of the primary particles was 0.30 μm, the average particle diameter of the secondary particles was 0.25 μm, and the color of the surface after forming the particles became gray. When the color difference of the roughened surface was measured, the color difference Δa * from white was 2.73, Δb * was 1.98 and ΔL * was −40.50, which satisfied the conditions of the present invention. No powder fall off, normal peel strength is as high as 0.92 kg / cm, heat resistance deterioration rate (measured peel strength after heating at 180 ° C. for 48 hours after measurement of normal peel, and the difference was taken as the deterioration rate) 30% It had the following small features.

In Example 14, the current density for forming the primary particles is 55 A / dm ² and 1 A / dm ² , and the coulomb amounts are 75 As / dm ² and 5 As / dm ^2. This is a case where 25 A / dm ² and the coulomb amount are 30 As / dm ² .
As a result, the average particle diameter of the primary particles was 0.35 μm, the average particle diameter of the secondary particles was 0.25 μm, and the color of the surface after forming the particles became gray. The color difference Δa * from white when the color difference of the roughened surface was measured was 2.23, Δb * was 1.52, and ΔL * was −48.95, which satisfied the conditions of the present invention. No powder fall off, normal peel strength is as high as 0.94 kg / cm, heat resistance deterioration rate (measured peel strength after heating at 180 ° C. for 48 hours after normal peel measurement, the difference was taken as the deterioration rate) 30% It had the following small features.

In Example 15, the current density for forming the primary particles is 50 A / dm ² and 5 A / dm ² , and the coulomb amounts are 70 As / dm ² and 10 As / dm ^2. This is a case where 25 A / dm ² and the coulomb amount are 30 As / dm ² .
As a result, the average particle diameter of the primary particles was 0.30 μm, the average particle diameter of the secondary particles was 0.25 μm, and the color of the surface after forming the particles became gray. When the color difference of the roughened surface was measured, the color difference Δa * from white was 3.70, Δb * was 2.38, and ΔL * was −49.49, which satisfied the conditions of the present invention. No powder fall off, normal peel strength is as high as 0.94 kg / cm, heat resistance deterioration rate (measured peel strength after heating at 180 ° C. for 48 hours after normal peel measurement, the difference was taken as the deterioration rate) 30% It had the following small features.

In Example 16, the current density for forming the primary particles is 50 A / dm ² and 2 A / dm ² , and the coulomb amounts are 70 As / dm ² and 3 As / dm ^2. This is a case where 15 A / dm ² and the coulomb amount are 30 As / dm ² .
As a result, the average particle size of the primary particles was 0.25 μm, and the secondary particles were almost covered (normal) in a plated state (particle size is less than 0.1 μm), and the surface color after forming the particles was gray. When the color difference of the roughened surface was measured, the color difference Δa * from white was 2.76, Δb * was 3.39, and ΔL * was −33.60, which satisfied the conditions of the present invention. No peeling off, normal peel strength as high as 0.81 kg / cm, heat resistance deterioration rate (measured peel strength after heating at 180 ° C. for 48 hours after normal peel measurement, and the difference was taken as the deterioration rate) 30% It had the following small features.

On the other hand, the comparative example has the following results.
In Comparative Example 1, the current density for forming primary particles is 63 A / dm ² and 10 A / dm ² , and the coulomb amounts are 80 As / dm ² and 30 As / dm ^2, and the secondary particles are not formed. It is. As a result, the average particle diameter of the primary particles was 0.50 μm, and the color tone of the surface after the formation of the particles was red. The color difference Δa * from white when the color difference of the roughened surface was measured was 36.32, Δb * was 23.62, and ΔL * was −34.72, which did not satisfy the conditions of the present invention. There was no powder falling.
The normal peel strength was as high as 1.38 kg / cm, which was an example level, but the heat resistance deterioration rate (after measuring the normal peel, the peel strength after heating at 180 ° C. for 48 hours was measured and the difference was taken as the deterioration rate). It was extremely bad at 60%. The overall evaluation as a copper foil for high-frequency circuits was poor.

Comparative Example 2 shows a conventional example in which there is no primary particle size and only a secondary particle layer. That is, the current density for forming the secondary particles is 50 A / dm ² and the coulomb amount is 30 As / dm ² .
As a result, the average particle diameter of the secondary particles was 0.30 μm, and the color tone of the surface after forming the particles was black. When the color difference of the roughened surface was measured, the color difference Δa * from white was 2.85, Δb * was 1.24, and ΔL * was −61.66, which did not satisfy the conditions of the present invention. As a result, the height of the secondary particles was large, and a large amount of powder falling occurred.
When the normal peel strength is as high as 1.25 kg / cm and the heat resistance deterioration rate (the peel strength after heating at 180 ° C. for 48 hours after the normal peel measurement is taken as the deterioration rate) is less than 30% It was an example level. As described above, since there is a problem that a large amount of powder falls off, the overall evaluation as a copper foil for high-frequency circuits was poor.

In Comparative Example 3, the current density for forming the primary particles is 63 A / dm ² and 1 A / dm ² , and the coulomb amounts are 80 As / dm ² and ² As / dm ^2. This is a case where 28 A / dm ² and the coulomb amount are 73 As / dm ² .
As a result, the average particle diameter of the primary particles was 0.35 μm, the average particle diameter of the secondary particles was 0.60 μm, and the color tone of the surface after forming the particles became gray. When the color difference of the roughened surface was measured, the color difference Δa * from white was 4.88, Δb * was 2.34, and ΔL * was −56.08, which deviated from the scope of the present invention. A large amount of powder fall occurred. The normal peel strength is as high as 1.42 kg / cm, and the heat resistance deterioration rate (after measuring the normal peel, the peel strength after heating at 180 ° C. for 48 hours is used as the deterioration rate) is less than 30%. It was an example level. Due to the large amount of powder falling, the overall evaluation as a copper foil for high-frequency circuits was poor.

In Comparative Example 4, the current density for forming the primary particles is 63 A / dm ² and 1 A / dm ² , and the coulomb amounts are 80 As / dm ² and ² As / dm ^2. This is a case where 31 A / dm ² and the coulomb amount are 40 As / dm ² .
As a result, the average particle diameter of the primary particles was 0.35 μm, the average particle diameter of the secondary particles was 0.40 μm, and the color tone of the surface after the particle formation was gray. When the color difference of the roughened surface was measured, the color difference Δa * from white was 4.87, Δb * was 2.22, and ΔL * was −60.81, which deviated from the scope of the present invention. A large amount of powder fall occurred. When the normal peel strength is as high as 1.37 kg / cm and the heat resistance deterioration rate (the peel strength after heating at 180 ° C. for 48 hours after the normal peel measurement is taken as the deterioration rate) is as small as 30% or less. Although it was an example level, evaluation as a copper foil for high frequency circuits as a whole was poor.

In Comparative Example 5, the current density for forming the primary particles is 63 A / dm ² and 10 A / dm ² , and the coulomb amounts are 80 As / dm ² and 30 As / dm ^2. This is a case where 31 A / dm ² and the coulomb amount are 40 As / dm ² .
As a result, the average particle diameter of the primary particles was 0.50 μm, the average particle diameter of the secondary particles was 0.40 μm, and the color tone of the surface after forming the particles became gray. When the color difference of the roughened surface was measured, the color difference Δa * from white was 4.04, Δb * was 1.84, and ΔL * was −54.05, which deviated from the scope of the present invention. Powder fall occurred. The normal peel strength is as high as 1.35 kg / cm, and the heat resistance deterioration rate (the peel strength after heating at 180 ° C. for 48 hours after the normal peel measurement is taken as the deterioration rate) is as small as 30% or less. Although it was an example level, evaluation as a copper foil for high frequency circuits as a whole was poor.

Comparative Example 6 is a case where the current density for forming the primary particles is 40 A / dm ² and 1 A / dm ² and the coulomb amounts are 40 As / dm ² and ² As / dm ^2. This is a case where 20 A / dm ² is used and the coulomb amount is 20 As / dm ² .
As a result, the average particle diameter of the primary particles was 0.15 μm, the average particle diameter of the secondary particles was 0.15 μm, and the color tone of the surface after forming the particles became light gray. When the color difference of the roughened surface was measured, the color difference Δa * from white was 1.85, Δb * was 4.15, and ΔL * was −36.42, which deviated from the scope of the present invention. Since the primary particles are small, the secondary particles are the same size, so it is considered that the color difference is light gray and the color difference is small.
Powder fall did not occur. Further, the normal peel strength was 0.71 kg / cm, and the heat resistance deterioration rate (the peel strength after heating at 180 ° C. for 48 hours after the normal peel measurement was measured and the difference was taken as the deterioration rate) was 35%. .

As is clear from the comparison of the above Examples and Comparative Examples, after forming a primary particle layer of copper on the surface of the copper foil (raw foil), 3 consisting of copper, cobalt and nickel is formed on the primary particle layer. When the secondary particle layer made of the base alloy is formed, the color tone is gray or black, and the color difference Δa * value from white when the color difference of the roughened surface is measured in the color difference system described in JISZ8730 is 4 0.0 or less and a color difference Δb * value of 3.5 or less have an excellent effect of being able to stably suppress a phenomenon called powder falling, further increasing peel strength, and high frequency. Characteristics can be improved.
The average particle diameter of the primary particle layer is 0.25 to 0.45 μm, and the average particle diameter of the secondary particle layer made of a ternary alloy made of copper, cobalt and nickel is 0.35 μm or less. It is more effective in achieving the effect.
Further, it is more effective to set the value of the color difference ΔL to −30 to −50 in achieving the above effect.
When Co is contained in the heat resistant treatment layer, the transmission loss tends to increase.

Claims (22)

  A copper foil in which a primary particle layer containing copper is formed on the surface of the copper foil, and then a secondary particle layer containing a ternary alloy composed of copper, cobalt and nickel is formed on the primary particle layer. A copper foil for high-frequency circuits having a color difference Δa * value of 4.0 or less and a color difference Δb * value of 3.5 or less when measured for the color difference of the roughened surface in the color difference system described in JISZ8730.   The average particle size of the primary particle layer of copper is 0.25 to 0.45 μm, and the average particle size of the secondary particle layer made of a ternary alloy made of copper, cobalt and nickel is 0.35 μm or less. Item 4. A copper foil for a high-frequency circuit according to Item 1.   The copper foil for a high-frequency circuit according to claim 1 or 2, wherein a color difference ΔL * value with white when a color difference of a roughened surface is measured in a color difference system is -30 to -50.   The high-frequency circuit copper foil according to any one of claims 1 to 3, wherein the primary particle layer and the secondary particle layer are electroplated layers.   The high frequency according to any one of claims 1 to 4, wherein the secondary particles are one or a plurality of dendritic particles grown on the primary particles or a normal plating layer grown on the primary particles. Copper foil for circuits.   The copper foil for a high frequency circuit according to any one of claims 1 to 5, wherein an adhesive strength between the primary particle layer and the secondary particle layer is 0.80 kg / cm or more.   The copper foil for a high frequency circuit according to claim 6, wherein the adhesive strength between the primary particle layer and the secondary particle layer is 0.90 kg / cm or more. On the secondary particle layer,
(A) an alloy layer composed of Ni and one or more elements selected from the group consisting of Fe, Cr, Mo, Zn, Ta, Cu, Al, P, W, Mn, Sn, As, and Ti, and
(B) The copper foil for high frequency circuits as described in any one of Claims 1-7 in which any one or both of the chromate layers were formed. On the secondary particle layer,
(A) an alloy layer composed of Ni and one or more elements selected from the group consisting of Fe, Cr, Mo, Zn, Ta, Cu, Al, P, W, Mn, Sn, As, and Ti, and
(B) one or both of the chromate layers,
The copper foil for high frequency circuits according to any one of claims 1 to 8, wherein the silane coupling layer is formed in this order. On the secondary particle layer,
The copper foil for high frequency circuits as described in any one of Claims 1-9 in which any one or both of a Ni-Zn alloy layer and a chromate layer were formed. On the secondary particle layer,
Either one or both of the Ni-Zn alloy layer and the chromate layer,
The copper foil for high frequency circuits as described in any one of Claims 1-10 in which the silane coupling layer was formed in this order.   The copper foil for high frequency circuits as described in any one of Claims 1-7 which equips the surface of the said secondary particle layer with a resin layer.   An alloy layer comprising Ni and one or more elements selected from the group consisting of Fe, Cr, Mo, Zn, Ta, Cu, Al, P, W, Mn, Sn, As, and Ti, or the chromate The copper foil for high frequency circuits as described in any one of Claims 8-11 provided with the resin layer on the surface of a layer or the said silane coupling layer, or the said Ni-Zn alloy layer.   It is a copper foil with a carrier which has an intermediate | middle layer and an ultra-thin copper layer in this order on the one surface of a carrier, or both surfaces, Comprising: The said ultra-thin copper layer is any one of Claims 1-13. Copper foil with carrier, which is a copper foil for high-frequency circuits.   The copper foil with a carrier according to claim 14, wherein the intermediate layer and the ultrathin copper layer are provided in this order on one surface of the carrier, and a roughening treatment layer is provided on the other surface of the carrier.   The copper clad laminated board for high frequency circuits using the copper foil as described in any one of Claims 1-15.   The printed wiring board for high frequency circuits using the copper foil as described in any one of Claims 1-15.   The copper-clad laminate for a high frequency circuit according to claim 16, wherein the copper foil and polyimide, liquid crystal polymer, or fluororesin are laminated.   The printed wiring board for a high-frequency circuit according to claim 17, wherein any one of polyimide, liquid crystal polymer, and fluororesin is used.   An electronic device using the printed wiring board according to claim 17 or 19. A step of preparing the carrier-attached copper foil according to claim 14 or 15 and an insulating substrate,
Laminating the copper foil with carrier and an insulating substrate;
After laminating the carrier-attached copper foil and the insulating substrate, a copper-clad laminate is formed through a step of peeling the carrier of the carrier-attached copper foil,
Then, the manufacturing method of a printed wiring board including the process of forming a circuit by any method of a semi-additive method, a subtractive method, a partly additive method, or a modified semi-additive method. Forming a circuit on the ultrathin copper layer side surface of the copper foil with a carrier according to claim 14 or 15,
Forming a resin layer on the ultrathin copper layer side surface of the carrier-attached copper foil so that the circuit is buried;
Forming a circuit on the resin layer;
Forming the circuit on the resin layer, and then peeling the carrier; and
After the carrier is peeled off, the printed wiring board includes a step of exposing the circuit embedded in the resin layer formed on the surface of the ultrathin copper layer by removing the ultrathin copper layer Method.