JP6511225B2 - Copper foil for high frequency circuit, copper clad laminate for high frequency circuit, printed wiring board for high frequency circuit, copper foil with carrier for high frequency circuit, electronic device, and method of manufacturing printed wiring board - Google Patents

Description

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

  Printed wiring boards have made great strides over the past half century, and are now used in almost all electronic devices. With the recent miniaturization of electronic devices and an increase in needs for higher performance, high-density mounting of mounted components and high frequency of signals have progressed, and excellent high frequency response to printed wiring boards is required.

  In order to ensure the quality of the output signal, a reduction in transmission loss is required for the high frequency substrate. The transmission loss mainly consists of dielectric loss due to the resin (substrate side) and 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 high frequency signals, conductor loss is mainly caused by a reduction in the cross section through which current flows due to the skin effect that the current flows only at the surface of the conductor as the frequency increases, and the resistance increases.

  As a technique aiming at reducing the transmission loss of the copper foil for high frequency, for example, in patent document 1, one side or both sides of the metal foil surface is coated with silver or a silver mixed metal, and the silver or silver alloy coated A metal foil for a high frequency circuit is disclosed in which a coating layer other than silver or silver alloy is applied thinner than the thickness of the silver or silver alloy coating layer on the layer. And, according to this, it is described that it is possible to provide a metal foil in which the loss due to the skin effect is reduced even in the ultrahigh frequency region as used in sanitary communication.

  Further, in Patent Document 2, the integrated intensity (I (200)) of the (200) plane determined by X-ray diffraction on the rolled surface after recrystallization annealing of the rolled copper foil is X-ray diffraction of fine powder copper. It is I (200) / I0 (200)> 40 with respect to the integral strength (I0 (200)) of the (200) plane determined, and the roughening process after the roughening process is performed to the rolled surface by electrolytic plating Arithmetic mean roughness (hereinafter referred to as Ra) of the surface is 0.02 μm to 0.2 μm, and 10-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, according to this, it is stated that it can provide a printed circuit board which can be used under high frequency over 1 GHz.

  Further, Patent Document 3 discloses an electrodeposited 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, which is a bump-like protrusion. And according to this, it is described that the electrolytic copper foil excellent in the high frequency transmission characteristic can be provided.

Patent No. 4161304 Patent No. 4704025 Unexamined-Japanese-Patent No. 2004-244656

  Although the conductor loss caused by 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 an influence of the resistance of the surface treatment layer formed by the roughening treatment performed to secure the adhesion of the copper, specifically, the roughness of the copper foil surface is the main factor of the conductor loss, and the roughness It is known that the transmission loss decreases as

  The inventors conducted further studies on the relationship between the surface roughness of the copper foil surface and the transmission loss. As the surface roughness of the copper foil surface is smaller, the transmission loss is not necessarily reduced. When the surface roughness is reduced to a certain degree, the relationship between the reduction of the transmission loss and the roughness of the copper foil surface shows remarkable variation, and the control of the roughness of the copper foil surface alone can reduce the transmission loss well. I found it difficult.

  Moreover, although formation of a cobalt-nickel alloy plated layer is known as a roughening process of the copper foil surface, the copper foil in which the conventional cobalt-nickel alloy plated layer was formed is a copper-formed on the surface. Since the shape of the roughened particles made of the cobalt-nickel alloy plating is dendritic, it peels off from the top or the root of this dendrite, causing a problem generally referred to as a powdering phenomenon.

  The powdering phenomenon is a troublesome problem, and the roughened layer of the copper-cobalt-nickel alloy plating is characterized by excellent heat resistance, but the particles are easily detached by external force. During the treatment, there were problems such as peeling due to "scrub" during processing, soiling of the roll due to peeling powder, and etching residue due to peeling powder.

  Therefore, according to the present invention, even when used in a high frequency circuit board, the transmission loss is favorably suppressed, and the phenomenon that the roughening particles formed on the copper foil surface peel off from the surface, that is, the occurrence of so-called "powdering" is good. It is an object of the present invention to provide a copper foil for high frequency circuits, a copper-clad laminate for high frequency circuits, a printed wiring board for high frequency circuits, and a printed circuit board for high frequency circuits, which are suppressed to

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

The present invention has been completed based on the above findings, and in one aspect, after a primary particle layer containing copper is formed on the surface of a copper foil, copper, cobalt and nickel are formed on the primary particle layer. A copper foil on which a secondary particle layer containing a ternary alloy is formed, and the color difference Δa * value with white when the color difference on the roughened surface is measured in the color difference system according to JIS Z 8730 is 2.22 to 2. .73, color difference Δb * value is 1.52 to 3.39, color difference ΔL * value with white when color difference of roughened surface is measured in color difference system is -30 to -50, the first order The average particle diameter of the particle layer is 0.25 to 0.45 μm, the average particle diameter of the secondary particle layer is 0.35 μm or less, and the primary particle layer and the secondary particle layer are electroplated layers Copper foil for high frequency circuits exceeding 1 GHz .

In still another embodiment of the copper foil for high frequency circuits of the present invention, in a further embodiment, secondary particles are normally plated on one or more dendritic particles grown on the primary particles or the primary particles. It is a layer.

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

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

In still another embodiment, the copper foil for high frequency circuits of the present invention, on the secondary particle layer,
(A) 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;
(B) Either one or both of the chromate layers are formed.

In still another embodiment, the copper foil for high frequency circuits of the present invention, on the secondary particle layer,
(A) 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;
(B) either one or both of the chromate layers,
A silane coupling layer is formed in this order.

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

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

In still another embodiment of the copper foil for high frequency circuits of the present invention, a resin layer is provided on the surface of the secondary particle layer.

The copper foil for high frequency circuits according to the present invention, in still another embodiment, comprises 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 an 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 side or both sides of the carrier, wherein the ultrathin copper layer is the one according to the 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 carrier of the present invention has the intermediate layer and the ultrathin copper layer in this order on one side of the carrier, and has a roughened layer on the other side of the carrier.

The present invention, in still another aspect, is a copper-clad laminate for high frequency circuits using the copper foil of the present invention.

In still 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 high frequency circuits according to the present invention has the copper foil laminated with a polyimide, a liquid crystal polymer or a fluorine resin.

In one embodiment, the printed wiring board for high frequency circuits of the present invention uses any of polyimide, a liquid crystal polymer, and a fluorine resin.

  Another aspect of the present invention is an electronic device using the printed wiring board of the present invention.

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

In still another aspect of the present invention, the step of forming a circuit on the surface of the copper foil with a carrier of the present invention on the very thin copper layer side,
Forming a resin layer on the very thin copper layer side surface of the copper foil with carrier so that the circuit is buried;
Forming a circuit on the resin layer;
Separating the carrier after forming a circuit on the resin layer;
A process for producing a printed wiring board including the step of exposing a circuit embedded in the resin layer formed on the surface of the ultrathin copper layer by removing the ultrathin copper layer after peeling off the carrier. It is a method.

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

It is concept 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. A conceptual explanation of a powder-free copper foil-treated layer according to the present invention, wherein a primary particle layer is formed in advance on a copper foil, and a secondary particle layer consisting of copper-cobalt-nickel alloy plating is formed on the primary particle layer. 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. According to the present invention, a primary particle layer is formed in advance on a copper foil, and a secondary particle layer consisting of copper-cobalt-nickel alloy plating is formed on the primary particle layer, and the layer on the copper foil-treated surface without dusting It is a microscope picture. A to C are schematic views of a cross section of a wiring board in steps up to circuit plating and resist removal according to a specific example of the method for producing a printed wiring board using the copper foil with a carrier of the present invention. D to F are schematic views of a cross section of a wiring board in a process from resin and second layer copper foil lamination with carrier to laser drilling according to a specific example of the method for producing a printed wiring board using the copper foil with carrier of the present invention It is. G to I are schematic views of a cross section of a wiring board in steps from via fill formation to first layer carrier peeling 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. J to K are schematic views of a cross section of a wiring board in steps from flash etching to formation of bumps and copper pillars according to a specific example of the method for producing a printed wiring board using the copper foil with a carrier of the present invention.

There is no restriction | limiting in particular in the form of the copper foil base | substrate 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. Generally, an electrodeposited copper foil is manufactured by electrolytically depositing copper on a drum of titanium or stainless steel from a copper sulfate plating bath, and a rolled copper foil is manufactured by repeating plastic working and heat treatment by rolling rolls. Rolled copper foil is often applied to applications where flexibility is required.
In addition to copper of high purity such as tough pitch copper and oxygen-free copper which is usually used as a conductor pattern of a printed wiring board as a material of a copper foil base material, for example, copper containing Sn, copper containing Ag, Cr, Zr or Mg is added It is also possible to use a copper alloy such as a copper alloy, a Corson-based copper alloy to which Ni, Si or the like is added. In addition, when the term "copper foil" is used independently in this specification, copper alloy foil shall also be included.
The thickness of the copper foil substrate is not particularly limited, but may be, for example, 1 to 1000 μm, 1 to 500 μm, 1 to 300 μm, 3 to 100 μm, 5 to 70 μm, 6 to 35 μm, or 9 ~ 18 μm.
Further, according to another aspect of the present invention, there is provided a copper foil with a carrier comprising a carrier, an intermediate layer and an ultrathin copper layer in this order, wherein the ultrathin copper layer is the copper foil for high frequency circuits of the present invention. It is a foil. That is, the 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 can be used for this invention as a copper foil base material. In the case of using a copper foil with a carrier in the present invention, a surface treatment layer such as the following roughening treatment layer is provided on the surface of the ultrathin copper layer. Note that another embodiment of the copper foil with carrier will be described later.

Usually, on the surface of the copper foil to be bonded to the resin substrate, that is, the roughened surface, the surface of the copper foil after degreasing is treated with the purpose of improving the peel strength of the copper foil after lamination A roughening process is performed to perform electrodeposition in the form of Although the electrodeposited copper foil has irregularities at the time of manufacture, the projections of the electrodeposited copper foil are strengthened by the roughening treatment to make the irregularities even larger. Conventional copper plating or the like may be performed as a pretreatment before roughening, and normal copper plating or the like may be performed as a finishing treatment after roughening to prevent detachment of the electrodeposit.
In the present invention, it is referred to as "roughening treatment" including known treatments related to copper foil roughening, as needed, including these pretreatment and finishing treatments.

  This roughening treatment is carried out by copper-cobalt-nickel alloy plating (in the following description, in order to clarify the difference between the roughening treatment of copper-cobalt-nickel alloy plating and the previous step) , “The secondary particle layer”), as described above, if the copper-cobalt-nickel alloy plated layer is simply formed on the copper foil, problems such as dusting occur as described above .

The micrograph of the surface of the copper foil in which the copper-cobalt-nickel alloy plated layer was formed on the copper foil is shown in FIG. As shown in FIG. 3, it is possible to see dendritic fine particles. Generally, the dendritically developed fine particles shown in FIG. 3 are produced at a high current density.
When treated at such a high current density, since nucleation of particles in initial electrodeposition is suppressed, new particle nuclei are formed at the tip of the particles. Will grow.
Therefore, in order to prevent this, when current density is lowered and electroplating is performed, sharp rise disappears, particles increase, and rounded shape particles grow. However, even under such circumstances, dusting is slightly improved, but sufficient peel strength can not be obtained, which is not sufficient to achieve the object of the present invention.

  The appearance of powder removal when a copper-cobalt-nickel alloy plated layer as shown in FIG. 3 is formed is shown in the conceptual explanatory view of FIG. The cause of the powdering is because fine particles in the form of dendritic particles are produced on the copper foil as described above, but the dendritic particles are apt to be broken in part of the dendrites by the external force and come off from the roots. The fine dendritic particles cause peeling due to "scrub" during processing, stain of the roll due to the peeling powder, and etching residue due to the peeling powder.

In the present invention, a primary particle layer of copper is previously formed on the surface of a copper foil, and then a secondary particle layer composed of a ternary alloy of copper, cobalt and nickel is formed on the primary particle layer. It is A photomicrograph of the surface on which the primary particles and secondary particles are formed on a copper foil is shown in FIG. 4 (details will be described later).
As a result, peeling due to "dust" during processing, soiling of the roll due to peeling powder, and etching residue due to peeling powder can be eliminated, that is, the phenomenon called powder falling can be suppressed, the peel strength is enhanced, 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 composed of a ternary alloy of copper, cobalt and nickel is 0.35 or less μm. As is apparent from the examples shown in Table 1, it is the optimum condition for preventing powdering. The lower limit of the average particle size 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, and 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 diameter 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. The lower limit of the average particle size of the secondary particle layer is not particularly limited, but, for example, 0.001 μm or more, 0.01 μm or more, 0.05 μm or more, 0.09 μm or more, 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 characteristics of the secondary particles are one or more dendritic particles grown on the primary particles. Or normal plating grown on the primary particles. That is, when the term "secondary particle layer" is used in the present specification, normal plating layers such as overlay plating are 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 the layer formed of roughened particles and normal It may be a layer having one or more plated layers.
The adhesive strength of 0.80 kg / cm or more, and further, the adhesive strength of 0.90 kg / cm or more of the primary particle layer and the secondary particle layer thus formed can be achieved.

  In the copper foil on which the primary particle layer and the secondary particle layer are formed, 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 according to JIS Z 8730 The color difference Δa * value with white at the time of measuring is 4.0 or less, and the color difference Δb * value is 3.5 or less. This color tone is the color difference based on JIS Z 8730. A LabiniScan XE Plus color difference meter made by HunterLab was used for color difference measurement. With this color difference meter, the color difference at the white board is made zero in the calibration work before measurement, and after performing other calibration work according to the instruction manual of the color difference meter, measure the color difference of the copper foil roughened surface The color differences Δa *, Δb * and ΔL * from the white color at the time of drying were determined. The same applies below.

In the copper foil on which the primary particle layer and the secondary particle layer are formed, the color tone is gray or black, and the color difference Δa * value with white when the color difference on the roughened surface is measured is 4.0 or less, the color difference Δb * The value is 3.5 or less. The upper limit of the color difference Δa * value with 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 does not need to be particularly limited, but for example 0 or more, 0.01 or more, or 0.05 or more, Or 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 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 white when measuring the color difference of the roughened surface of the copper foil does not have to be limited, for example, 0 or more, 0.01 or more, or 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 flexible printed circuit (FPC), semiconductor mounting technology by high definition and high density advances, and alignment accuracy by image recognition of copper foil circuit through resin substrate of FPC becomes important . A polyimide resin is mainly used as the FPC substrate resin, and the color of this polyimide resin is yellow. In the color difference system of JIS Z 8730, the color difference Δa * value with 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 appearance different from red or yellow, and the polyimide resin substrate You will be able to clarify the color distinction between Furthermore, such adjustment of the color difference has the effect of stably improving the peel strength and preventing the powder dropping phenomenon. If the formula color difference is such that the color difference Δa * value is larger than 4.0 or more, or the color difference Δb * value is larger than 3.5 or more, powder fallout is likely to occur. It can be said that it is desirable.

  Moreover, in the copper foil in which the primary particle layer and the secondary particle layer were formed, 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. If the value of the color difference ΔL * from white when measuring the color difference on the roughened surface of the copper foil is in the range of -30 to -50, powder falling tends to be difficult to occur. The lower limit of the color difference ΔL * to white when the color difference on the roughened surface of the copper foil is measured is preferably −49.5 or more, more preferably −49.0 or more. Further, the upper limit of the color difference ΔL * to white when the color difference on the roughened surface of the copper foil is measured is preferably -31 or less, more preferably -32 or less, and more preferably -33 or less. More preferably, it is -35 or less, more preferably -40 or less.

  The term "roughened surface" in "the color difference of the roughened surface of the copper foil" means the surface on the final product and means the outermost surface on which the primary particle layer and the secondary particle layer are formed. . Moreover, when surface treatment layers, such as a heat-resistant layer, an antirust layer, a silane coupling treatment 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 on the side which formed the primary particle layer of copper foil and the secondary particle layer except the said resin layer is meant.

On the secondary particle layer,
(A) 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; (B) Either one or both of the chromate layers may be formed.
In addition, one or more kinds selected from the group consisting of (A) Ni and Fe, Cr, Mo, Zn, Ta, Cu, Al, P, W, Mn, Sn, As and Ti on the secondary particle layer. An alloy layer composed of an element and / or (B) a chromate layer or both and a 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, on the secondary particle layer, one or both of the Ni—Zn alloy layer and the chromate layer, and the silane coupling layer may be formed in this order.
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, signal attenuation at the time of signal transmission at high frequency is suppressed, so that stable signal transmission can be performed in a circuit that performs signal transmission at high frequency. Therefore, it is preferable that the value of the transmission loss is small because it is suitable for use in a circuit application that performs signal transmission at 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 50 Ω, and a network made by HP Co. 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 obtained, the transmission loss at a frequency of 20 GHz is preferably less than 5.0 dB / 10 cm, more preferably less than 4.1 dB / 10 cm Preferably, less than 3.7 dB / 10 cm is even more preferred.

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 etc. For example, for rigid PWB, paper base phenol resin, paper base epoxy resin, synthetic fiber cloth base epoxy resin , Glass cloth / paper composite base epoxy resin, glass cloth / glass non-woven composite base epoxy resin, glass cloth base epoxy resin, etc., polyester film or polyimide film for FPC, liquid crystal polymer (LCP) film, fluorine Resin etc. can be used. When a liquid crystal polymer (LCP) film or a fluorine resin film is used, the peel strength of 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 fluorine resin film is used, after the copper circuit is formed, the film and the copper circuit are less likely to be peeled off by covering the copper circuit with a coverlay, and the peel strength is reduced. Peeling between the film and the copper circuit can be prevented.
In addition, since a liquid crystal polymer (LCP) film or a fluorine resin film has a small dielectric loss tangent, a copper-clad laminate using a liquid crystal polymer (LCP) film or a fluorine resin film and the surface-treated copper foil according to the present invention Boards and printed circuit boards are suitable for high frequency circuits (circuits that transmit signals at high frequencies). In addition, 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 is suitable for high frequency circuit applications.

  In the case of a rigid PWB, a method of bonding is to impregnate a base material such as a glass cloth with a resin and prepare a prepreg in which the resin is cured to a semi-cured state. It can carry out by putting a copper foil on a prepreg from the surface on the opposite side of a coating layer, heating and pressurizing. In the case of FPC, lamination adhesion is carried out to copper foil under high temperature and high pressure through a base material such as a polyimide film through an adhesive or without using an adhesive, or a polyimide precursor is applied / dried / cured etc. Can produce a laminate.

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

Furthermore, by mounting electronic components on the printed wiring board, the printed circuit board is completed. In the present invention, the term "printed wiring board" also includes a printed wiring board, a printed circuit board and a printed circuit board on which electronic components are thus mounted.
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 The substrate may be used to manufacture an electronic device.

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

(Plating conditions for secondary particles)
In the same manner as described above, this plating condition is merely a preferred example, and the secondary particles are formed on the primary particles, and the average particle diameter plays a role of preventing powder fall off. is there. Therefore, as long as the average particle size falls within the range of the present invention, plating conditions other than those indicated below do not hinder at all. The present invention includes these.
Liquid composition: Copper 10 to 20 g / L, nickel 5 to 15 g / L, cobalt 5 to 15 g / L
pH: 2 to 3
Liquid temperature: 30 to 50 ° C
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 to 20 g / L, cobalt 1 to 8 g / L
pH: 2 to 3
Liquid temperature: 40 to 60 ° C
Current density: 5 to 20 A / dm ²
Coulomb amount: 10 to 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 to 30 g / L, zinc 2 to 30 g / L
pH: 3 to 4
Liquid temperature: 30 to 50 ° C
Current density: 1 to ^{2 A} / dm ²
Coulomb amount: 1 to ^{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: 2 to 30 g / L of nickel, 2 to 30 g / L of copper
pH: 3 to 4
Liquid temperature: 30 to 50 ° C
Current density: 1 to ^{2 A} / dm ²
Coulomb amount: 1 to ^{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: Sulfuric acid Ni hexahydrate: 45 to 55 g / dm ³ , sodium molybdate dihydrate: 50 to 70 g / dm ³ , sodium citrate: 80 to 100 g / dm ³
Liquid temperature: 20 to 40 ° C
Current density: 1 to 4 A / dm ²
Coulomb amount: 1 to ^{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 to 30 g / L, tin 2 to 30 g / L
pH: 1.5 to 4.5
Liquid temperature: 30 to 50 ° C
Current density: 1 to ^{2 A} / dm ²
Coulomb amount: 1 to ^{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: 30 to 70 g / L of nickel, 0.2 to 1.2 g / L of phosphorus
pH: 1.5 to 2.5
Liquid temperature: 30 to 40 ° C
Current density: 1 to ^{2 A} / dm ²
Coulomb amount: 1 to ^{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 to 30 g / L, W 0.01 to 5 g / L
pH: 3 to 4
Liquid temperature: 30 to 50 ° C
Current density: 1 to ^{2 A} / dm ²
Coulomb amount: 1 to ^{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 plated 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 to 85 mass%, Cr: 15 to 35 mass%
Equipment: Sputtering equipment manufactured by ULVAC, Inc. Output: DC 50 W
Argon pressure: 0.2 Pa

(Plating conditions to form a rustproof layer)
The present invention can further form the following rustproof layer. The plating conditions are shown below. Although the conditions for immersion chromate treatment are described below, electrolytic chromate treatment may be used.
Liquid composition: Potassium dichromate 1 to 10 g / L, zinc 0 to 5 g / L
pH: 3 to 4
Liquid temperature: 50 to 60 ° C
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 weather resistant layer (silane coupling layer))
As an example, application of diaminosilane aqueous solution can be mentioned.
In the case where the metal layer such as the heat resistant layer or the like is provided by dry plating such as sputtering, or the metal layer such as the heat resistant layer or the like is provided by the wet plating, When the metal layer or the like and the plating layer are normal plating (smooth plating, that is, plating performed with a current density less than the limiting current density), the metal layer and the plating layer do not affect the shape of the surface of the copper foil.
The limiting current density changes depending on the metal concentration, pH, feed rate, distance between electrodes, and plating solution temperature, but in the present invention, normal plating (state where plated metal is deposited in layers) and roughening plating ( The current density at the boundary between burnt plating and plated metal in the form of crystals (spheroid, needle-like, ice-like, etc., precipitated or uneven) is defined as the limit current density, and it is The current density (visual judgment) at the limit (immediately before burn plating) at which normal plating is performed is defined as the limiting current density.
Specifically, the metal concentration, pH, and plating solution temperature are set to the manufacturing conditions of plating, and the Hull cell test is performed. Then, the composition of the plating solution and the state of forming a metal layer at the temperature of the plating solution (whether the plated metal is deposited in a layer or in a crystalline form) are examined. Then, based on the current density chart made by Yamamoto Gold Testing Co., Ltd., the current density at the position of the boundary of the test piece is determined from the position of the test piece in the portion where the boundary between normal plating and roughening plating exists. Then, the current density at the position of the boundary is defined as the limit current density. Thereby, the composition of the plating solution and the limit current density at the temperature of the plating solution can be known. In general, when the distance between the electrodes is short, the limit current density tends to be high.
The method of the Hull cell test is described, for example, in “Plating Practice Reader”, Kiyoshi Maruyama, Nikkan Kogyo Shimbun, Inc., pp. 157-160 on June 30, 1983.
In addition, in order to perform a plating process below a limit current density, it is preferable to make the current density at the time of a plating process into 20 A / dm < ² > or less, it is preferable to set it as 10 A / dm < ² > or less, and 8A / dm < ² > or less It is preferable to do.
In addition, the chromate layer and the silane coupling layer do not affect the color difference on the surface of the copper foil because the thickness thereof is extremely thin.

The copper-cobalt-nickel alloy plating as the secondary particles is a ternary alloy of 10 to 30 mg / dm ² copper-100 to 3000 μg / dm ² cobalt-50 to 500 μg / dm ² nickel by electrolytic plating. Layers can be formed.
If the amount of Co deposition is less than 100 μg / dm ² , the heat resistance will deteriorate and the etchability will also deteriorate. When the Co deposition amount exceeds 3000 μg / dm ² , it is not preferable when the influence of magnetism has to be taken into consideration, etching stains occur, and deterioration of acid resistance and chemical resistance can be taken into consideration.

If the amount of Ni attached is less than 50 μg / dm ² , the heat resistance will deteriorate. On the other hand, when the Ni deposition amount exceeds 500 μg / dm ² , the etchability is reduced. That is, although it is not a level which an etching residue can form and it can not etch, fine patterning becomes difficult. 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 this ternary alloy layer is a desirable condition to the last, and does not deny the range exceeding this amount.

Here, the etching stain means that Co does not dissolve when etched with copper chloride, and the etching residue means that Ni does not dissolve when Al is etched by ammonium chloride. It means to end up.
Generally, when forming a circuit, it is carried out using an alkaline etching solution and a copper chloride-based etching solution as described in the following examples. It is to be understood that the etchant and the etching conditions are versatile, but are not limited to these conditions and can be arbitrarily selected.

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

In addition, when the cobalt adhesion amount is large, it may cause the occurrence of soft etching soaking. From this, it can be said that the proportion of cobalt is preferably 60 to 66% by mass.
As described later, the direct cause of the occurrence of the soft etching penetration is the heat-resistant rustproof layer consisting of the zinc-nickel alloy plated layer, but cobalt may also be the cause of the stain generation during the soft etching. The above adjustment is a more desirable condition.
On the other hand, when the adhesion amount of nickel is small, the heat resistant peel strength is lowered, and the oxidation resistance and the chemical resistance are lowered. Further, when the nickel deposition amount is too large, the alkali etching property is deteriorated, and therefore, it is desirable to determine by the balance with the above-mentioned cobalt content.

The present invention can further form a zinc-nickel alloy plated layer on cobalt-nickel alloy plating. The total amount of the zinc-nickel alloy plated layer is 150 to 500 μg / dm ² , and the ratio of nickel is 16 to 40% by mass. This has a role of a heat resistant rustproof 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 carried out in the circuit manufacturing process becomes even higher temperature, and there is heat generation during use of the device after it becomes a product. For example, in a so-called two-layer material in which a copper foil is bonded to a resin by thermocompression bonding, heat is received at 300 ° C. or more at the time of bonding. Even in such a situation, it is necessary to prevent the decrease in the bonding strength between the copper foil and the resin base material, and this zinc-nickel alloy plating is effective.

Further, in the prior art, in a minute circuit provided with a zinc-nickel alloy plated layer in a two-layer material in which a copper foil is joined to a resin by thermocompression bonding, discoloration occurs due to soaking in the edge portion of the circuit during soft etching. Occur. Nickel has the effect of suppressing the infiltration of an etching agent (H ₂ SO ₄ : 10 wt%, H ₂ O ₂ : 2 wt% etching aqueous solution) used during soft etching.
As described above, the total amount of the zinc-nickel alloy plated layer is 150 to 500 μg / dm ^2, and the lower limit of the nickel ratio in the alloy layer is 16% by mass, and the upper limit is 40% by mass, and nickel The content of 50 μg / dm ² or more provides the role of a heat-resistant rustproof layer and suppresses the penetration of the etching agent used in the soft etching, and prevents the weakening of the joint strength of the circuit due to corrosion. It has the effect of being able to

If the total amount of the zinc-nickel alloy plated layer is less than 150 μg / dm ² , the heat and rustproofing ability decreases and it becomes difficult to play a role as a heat and rustproof layer, and if the total amount exceeds 500 μg / dm ² , Resistance to hydrochloric acid tends to be poor.
If the lower limit value 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 of 40% by mass of the nickel ratio is a technical limit value capable of forming a zinc-nickel alloy plated layer.

As described above, according to the present invention, the cobalt-nickel alloy plated layer, and further the zinc-nickel alloy plated layer may be sequentially formed on the copper-cobalt-nickel alloy plated layer as the secondary particle layer, if necessary. it can. The total amount of cobalt and nickel coverages 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 .
If the total adhesion amount of cobalt is less than 300 μg / dm ² , heat resistance and chemical resistance decrease, and if the total adhesion amount of cobalt exceeds 4000 μg / dm ² , etching spots may occur, and transmission loss is large. May be If the total adhesion amount of nickel is less than 100 μg / dm ² , the heat resistance and the chemical resistance may be lowered. If the total deposition amount of nickel exceeds 1500 μg / dm ² , etching residues 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, it is not necessary to be particularly limited to the conditions described in this paragraph.

After this, anticorrosion treatment is carried out as required. In the present invention, a preferable rustproofing treatment is a coating treatment of chromium oxide alone or a mixture coating treatment of chromium oxide and zinc / zinc oxide. A mixture film treatment of chromium oxide and zinc / zinc oxide is zinc consisting of zinc or zinc oxide and chromium oxide by electroplating using a plating bath containing zinc salt or zinc oxide and chromate. It is the process which coats the rustproof layer of the chromium base mixture.
As the plating bath, typically, at least one of a 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, ZnSO ₄ · 7H A mixed aqueous solution of at least one such as ₂ O and an alkali hydroxide is used. Typical plating bath compositions and examples of electrolysis conditions are as follows.

The copper foil thus obtained has excellent heat resistant peel strength, oxidation resistance and hydrochloric acid resistance. In addition, it is possible to etch a circuit having a circuit width of 150 μm or less with a CuCl ₂ etching solution, and also enable alkaline etching. In addition, it is possible to suppress the infiltration into the circuit edge portion at the time of soft etching.
As a soft etching solution, an aqueous solution of 10 wt% H ₂ SO _{4 and 2} wt% H ₂ O ₂ can be used. Processing time and temperature can be adjusted arbitrarily.
As an alkaline etching liquid, for example, a liquid such as NH ₄ OH: 6 mol / l, NH ₄ Cl: 5 mol / l, CuCl ₂ : 2 mol / l (temperature 50 ° C.) is known.

The copper foils obtained in all the above steps have black to gray. Black to gray are significant in terms of high alignment accuracy and high heat absorption rate. For example, in a circuit board including a rigid board and a flexible board, components such as an IC, a resistor, and a capacitor are mounted by an automatic process. At this time, alignment on a copper foil treated surface may be performed through a film such as Kapton. Also, the positioning at the time of forming the through holes is the same.
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 by bonding while being heated. At this time, when heating is performed by using long waves such as far infrared rays and infrared rays, the heating efficiency is improved as the color tone of the treated surface is black.

Finally, if necessary, at least the roughened surface on the anticorrosion layer is subjected to silane treatment in which a silane coupling agent is applied for the purpose of improving the adhesion between the copper foil and the resin substrate. As the silane coupling agent used for this silane treatment, olefin based silanes, epoxy based silanes, acrylic based silanes, amino based silanes and mercapto based silanes can be mentioned, but these can be appropriately selected and used. . In addition, when using a liquid crystal polymer as resin, it is preferable to use an 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 coating method may be spraying with a silane coupling agent solution, coating with a coater, dipping, pouring or the like. For example, Japanese Patent Publication No. 60-15654 describes that the adhesion between copper foil and resin substrate is improved by performing chromate treatment on the rough side of copper foil and then treating with silane coupling agent. . Please refer to this for details. After this, if necessary, an annealing treatment may be applied for the purpose of improving the ductility of the copper foil.

[Copper foil with carrier]
The copper foil with carrier according to another embodiment of the present invention has an intermediate layer and a very thin 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.

<Carrier>
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 an alloy foil, an insulating resin film (for example, a polyimide film, a liquid crystal polymer (LCP) film, a polyethylene terephthalate (PET) film, a polyamide film, a polyester film, a fluorine resin film, etc.).
It is preferable to use a copper foil as a carrier that can be used in the present invention. Since the copper foil has high electrical conductivity, the subsequent formation of the intermediate layer and the extremely thin copper layer is facilitated. The carrier is typically provided in the form of rolled copper foil or electrolytic copper foil. Generally, an electrodeposited copper foil is manufactured by electrolytically depositing copper on a drum of titanium or stainless steel from a copper sulfate plating bath, and a rolled copper foil is manufactured by repeating plastic working and heat treatment by rolling rolls. As a material of the copper foil, besides copper of high purity such as tough pitch copper and oxygen free copper, copper containing Sn, copper containing Ag, copper alloy to which Cr, Zr, Mg or the like is added, Corson type to which Ni, Si or the like is added 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 can be, for example, 5 μm or more. However, if it is too thick, the production cost will increase, so in general, the thickness is preferably 35 μm or less. Thus, the thickness of the carrier is typically 12 to 70 μm, more typically 18 to 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 roughening treatment layer on the surface of the carrier opposite to the surface on which the ultrathin copper layer is provided means that the carrier is laminated to a support such as a resin substrate from the surface side having the roughening treatment layer. It has the advantage that it becomes difficult to peel off the carrier and the resin substrate.

<Middle class>
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 difficult to peel from the carrier prior to the lamination step on the insulating substrate with the copper foil with carrier, while the ultrathin copper layer from the carrier is after the lamination step on the insulating substrate The configuration is not particularly limited as long as the configuration is such that it can be peeled off. For example, the intermediate layer of the copper foil with a carrier according to the present invention may be made of Cr, Ni, Co, Fe, Mo, Ti, W, P, Cu, Al, Zn, their alloys, their hydrates, their oxides, One or more selected from the group consisting of organic substances may be included. Also, the intermediate layer may be a plurality of layers.
Also, for example, the intermediate layer is a single metal layer consisting of a kind of element selected from the group of elements consisting of Cr, Ni, Co, Fe, Mo, Ti, W, P, Cu, Al, Zn from the carrier side Or form an alloy layer composed of one or more elements selected from the group of elements composed of Cr, Ni, Co, Fe, Mo, Ti, W, P, Cu, Al, Zn, Hydrates or oxides of one or more elements selected from the group of elements consisting of Cr, Ni, Co, Fe, Mo, Ti, W, P, Cu, Al, Zn, or organic substances Or a single metal layer consisting of one element selected from the group of elements 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 an anticorrosive 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 part of the deposited metal such as chromium or zinc may be a hydrate or an oxide.
Also, 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 the carrier. Since the adhesion between nickel and copper is higher than the adhesion between chromium and copper, when peeling off the very thin copper layer, it peels off at the interface between the very thin copper layer and the chromium. In addition, a barrier effect is expected in the nickel of the intermediate layer to prevent the diffusion of the copper component 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 adhesion amount of chromium in the intermediate layer is preferably 5 μg / dm ² or more and 100 μg / dm ² or less.

<Ultra-thin copper layer>
An ultra-thin copper layer is provided on the middle layer. Other layers may be provided between the intermediate layer and the very thin copper layer. The extremely thin copper layer can be formed by electroplating using an electrolytic bath of copper sulfate, copper pyrophosphate, copper sulfamate, copper cyanide, etc., and is used in a general electrolytic copper foil, with high current density A copper sulfate bath is preferred because copper foil formation is possible. 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, an ultrathin copper layer may be provided on both sides of the carrier.

  In this way, a copper foil with carrier comprising the carrier, the intermediate layer laminated on the carrier, and the 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 a very thin copper layer is a paper base phenolic resin, paper base epoxy resin, synthetic fiber cloth base epoxy resin, glass cloth / paper composite Base material epoxy resin, glass cloth · glass non-woven fabric composite base material epoxy resin and glass cloth base material Epoxy resin, polyester film, polyimide film, etc. The ultrathin copper layer adhered to the substrate can be etched into the desired conductor pattern to finally produce a printed wiring board.

  In addition, a copper foil with a carrier comprising a carrier, an intermediate layer laminated on the carrier, and an ultrathin copper layer laminated on the intermediate layer comprises a roughened layer on the ultrathin copper layer In addition, one or more layers selected from the group consisting of a heat-resistant layer, an anticorrosive layer, a chromate (treated) layer, and a silane coupling (treated) layer may be provided on the roughened layer.

[Resin layer]
A resin layer may be formed on the surface of the secondary particle layer of the copper foil for high frequency circuits of the present invention (including the case where the copper foil for high frequency circuits is an ultrathin copper layer of copper foil with carrier). 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 the alloy layer composed of one or more elements selected from the group consisting of Ti, may be formed on the surface of the chromate layer, or may be formed on the surface of the silane coupling layer. You may form on the surface of a Ni-Zn alloy layer. The resin layer is more preferably formed on the outermost surface of the copper foil for high frequency circuits. Further, the copper foil with carrier may be provided with a resin layer on the roughened layer, or on the heat resistant layer, the rustproof 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 may be an insulating resin layer in a semi-cured state (B-stage state) for bonding. In the semi-cured state (B-stage state), there is no sticky feeling even when the surface is touched with a finger, the insulating resin layer can be stacked and stored, and a curing reaction occurs when heat treatment is further performed. Including.

  The resin layer may contain a thermosetting resin or may be a thermoplastic resin. In addition, the resin layer may contain a thermoplastic resin. Although the type is not particularly limited, for example, a resin containing an epoxy resin, a polyimide resin, a polyfunctional cyanate ester compound, a maleimide compound, a polyvinyl acetal resin, a urethane resin, etc. can be mentioned as a suitable one. .

  The resin layer may be any known resin, resin curing agent, compound, curing accelerator, dielectric (a dielectric including an inorganic compound and / or an organic compound, a dielectric including a metal oxide, etc. ), Reaction catalysts, crosslinking agents, polymers, prepregs, frameworks and the like. In addition, the resin layer may have, for example, International Publication Number WO2008 / 004399, International Publication Number WO2008 / 053878, International Publication Number WO2009 / 084533, Japanese Patent Application Laid-Open No. 11-5828, Japanese Patent Application No. 11-140281, Patent No. 3184485, International Publication Number WO 97/02728, Patent No. 3676375, JP-A 2000-43188, Patent No. 3612594, JP-A 2002-179772, JP-A 2002-359444, JP-A 2003-304068, JP 3992225, JP-A 2003 No. 249739, Patent No. 4136509, Japanese Patent No. 2004-82687, Japanese Patent No. 4025177, Japanese Patent No. 2004-349654, Japanese Patent No. 4286060, Japanese Patent No. 2005-262506, Japanese Patent No. 4570070, Japanese Patent No. 20 Patent No. 5-53218, Patent No. 3949676, Patent No. 4178415, International Publication No. WO 2004/005588, Japanese Patent Publication No. 2006-257153, Japanese Patent Publication No. 2007-326923, Japanese Patent Publication No. 2008-111169, Patent No. 5024930, International Publication No. WO2006 / 028207, Patent No. 4828427, Japanese Patent Application Publication No. 2009-67029, International Publication No. WO2006 / 134868, Patent No. 5046927, Japanese Patent Application Publication No. 2009-1730017, International Publication No. WO2007 / 105635, Patent No. 5180815, International Publication No. WO2008 / 114858, International Publication No. WO2009 / 008471, Japanese Patent Application Publication No. 2011-14727, International Publication No. WO2009 / 001850, International Publication No. WO2009 / 145179, International Publication No. WO2011 / 068157, JP-A-2013-19056 (a resin, a resin curing agent, a compound, a curing accelerator, a dielectric, a reaction catalyst, a crosslinking agent, a polymer, a prepreg, a skeletal material, 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) or toluene to form a resin solution, which is used on the copper foil or the ultrathin copper layer, or the heat resistant layer, the rustproof layer, or the chromate film layer Alternatively, it is coated on the silane coupling agent layer, for example, by a roll coater method or the like, and then, it is dried by heating if necessary to remove the solvent and put in a B-stage state. For drying, for example, a hot air drying furnace may be used, and the drying temperature may be 100 to 250 ° C., preferably 130 to 200 ° C.

The copper foil for high frequency circuits provided with the resin layer (copper foil for high frequency circuits with resin) is formed by laminating the resin layer on a substrate and then thermocompression bonding the whole to thermoset the resin layer, and then copper foil Are used in the form of forming a predetermined wiring pattern.
Further, the copper foil with carrier provided with the resin layer (copper foil with carrier provided with resin) is formed by laminating the resin layer on a substrate and then thermocompression bonding the whole to thermally cure the resin layer, and then the carrier It is used in an aspect in which peeling is performed to expose an extremely thin copper layer (it is the surface on the side of the middle layer of the very thin copper layer that is naturally revealed), and a predetermined wiring pattern is formed there.

  The use of the resin-coated copper foil for a high frequency circuit or the resin-coated carrier-coated copper foil can reduce the number of used prepreg materials at the time of producing a multilayer printed wiring board. In addition, it is possible to manufacture a copper-clad laminate even if the thickness of the resin layer is such that interlayer insulation can be secured or the prepreg material is not used at all. At this time, the surface of the substrate may be undercoated with an insulating resin to further improve the surface smoothness.

  In the case where a prepreg material is not used, the material cost of the prepreg material is saved, and the lamination process is simplified, which is economically advantageous. Furthermore, the multilayer printed wiring board manufactured by the thickness of the prepreg material 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 smaller than 0.1 μm, the adhesive force is reduced, and the circuit of the inner layer material when the copper foil with a carrier with a resin is laminated on the base material provided with the inner layer material without interposing the prepreg material. It may be difficult to secure interlayer insulation between them.

  On the other hand, when the thickness of the resin layer is greater than 80 μm, it becomes difficult to form the resin layer of the desired thickness in one application step, which is economically disadvantageous because extra material cost and man-hours are required. Furthermore, since the formed resin layer is poor in flexibility, cracks and the like 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 resin, it is a resin layer on the above-mentioned very thin copper layer, or the above-mentioned heat-resistant layer, antirust layer, or the above-mentioned chromate layer or above-mentioned silane coupling layer. After coating and semi-hardening, it is also possible to peel off the carrier and produce it in the form of a copper foil with resin (very thin copper layer) without the carrier.

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

  In one embodiment of the 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, with the carrier After laminating the copper foil and the insulating substrate so that the very thin copper layer side faces the insulating substrate, the carrier of the copper foil with carrier is removed to form a copper-clad laminate, and then the semi-additive method, modified semi Forming a circuit by any of an additive method, a partory additive method and a subtractive method. The insulating substrate may be one including an inner layer circuit.

  In the present invention, in the semi-additive method, a thin electroless plating is performed on an insulating substrate or a copper foil seed layer, and after forming a pattern of a plating resist, a conductor pattern is formed by performing electroplating and removing and etching the plating resist. Refers to a method that includes forming.

  In the present invention, in the modified semi-additive method, a metal foil is laminated on an insulating layer, a non-circuit forming portion is protected by a plating resist, copper plating of the circuit forming portion is performed by electrolytic plating, and then the resist is removed. And removing the metal foil other than the circuit formation portion by (flash) etching to form a circuit on the insulating layer.

  In the present invention, in the partly additive method, a catalyst core is provided on a substrate provided with a conductor layer, and a substrate provided with holes for through holes and via holes as necessary, and a conductor circuit is formed by etching. A method of manufacturing a printed wiring board by a method including providing a solder resist or a plating resist as required, and then performing thickness plating by electroless plating on the conductive circuit, through holes, via holes, etc. Point to

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

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

Here, a specific example of the method for producing a printed wiring board using the copper foil with carrier of the present invention will be described in detail with reference to the drawings.
First, as shown to FIG. 5-A, the copper foil with a carrier (1st layer) which has the ultra-thin copper layer by which the roughening process layer was formed in the surface is prepared.
Next, as shown in FIG. 5B, a resist is applied on the roughened layer of the extremely thin copper layer, exposed and developed, and the resist is etched into a predetermined shape.
Next, as shown in FIG. 5C, plating for a circuit is formed, and then the resist is removed to form a circuit plating having a predetermined shape.
Next, as shown in FIG. 6-D, a buried resin is provided on the ultrathin copper layer to cover the circuit plating (so that the circuit plating is buried), and the resin layer is laminated, and then another carrier is attached. Bond the copper foil (second layer) from the very thin copper layer side.
Next, as shown in FIG. 6E, the carrier is peeled off from the second layer of copper foil with carrier.
Next, as shown in FIG. 6-F, laser drilling is performed at a predetermined position of the resin layer to expose the circuit plating to form a blind via.
Next, as shown in FIG. 7G, copper is buried in the blind vias to form a via fill.
Next, as shown in FIG. 7-H, circuit plating is formed on the via fill as shown in FIGS. 5-B and 5-C.
Next, as shown in FIG. 7I, the carrier is peeled off from the first layer of copper foil with carrier.
Next, as shown in FIG. 8J, the ultrathin copper layer on both surfaces is 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, a printed wiring board using the copper foil with carrier of the present invention is produced.

  The other copper foil with carrier (second layer) may use the copper foil with carrier of the present invention, may use a conventional copper foil with carrier, and may further use a normal copper foil. Further, one or more layers of circuits may be further formed on the circuit of the second layer shown in FIG. 7-H, and these circuits may be formed by semi-additive method, subtractive method, party additive method or modified semi-conductor. It may be carried out by any of the additive methods.

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

  In addition, well-known resin and a prepreg can be used for embedding resin (resin). For example, a prepreg which is a glass cloth impregnated with BT (bismaleimide triazine) resin or BT resin, ABF film or ABF manufactured by Ajinomoto Fine Techno Co., Ltd. can be used. In addition, the resin layer and / or the resin and / or the prepreg described in the present specification can be used as the embedding resin (resin).

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

Hereinafter, it demonstrates based on an Example and a comparative example. The present embodiment is merely an example, and the present invention is not limited to this example. That is, it includes other aspects or modifications included in the present invention. The base foils of Examples 2 to 6 and 12 to 16 and Reference Examples 1 and 7 and Comparative Examples 1 to 6 are 18 μm of standard rolled copper foil TPC (tough pitch copper specified in JIS H3100 C1100). used.
Moreover, the copper foil with a carrier manufactured by the following method was used for Example 8-11 original foil.
In Examples 8 to 10, an 18 μm thick electrolytic copper foil (JX Nippon Steel Corp. JTC foil) is prepared as a carrier, and for Example 11, the above-described 18 μm thick standard rolled copper foil TPC is prepared as a carrier did. Then, an intermediate layer was formed on the surface of the carrier under the following conditions, and an extremely thin 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
<Middle class>
(1) Ni layer (Ni plating)
The carrier was electroplated on a continuous roll-to-roll plating line under the following conditions to form a 1000 μg / dm ² adhesion amount Ni layer. Specific plating conditions are described below.
Nickel sulfate: 270 to 280 g / L
Nickel chloride: 35 to 45 g / L
Nickel acetate: 10 to 20 g / L
Boric acid: 30 to 40 g / L
Brightener: Saccharin, butynediol, etc. Sodium dodecyl sulfate: 55 to 75 ppm
pH: 4 to 6
Bath temperature: 55 to 65 ° C
Current density: 10A / dm ²
(2) Cr layer (electrolytic chromate treatment)
Next, after washing the surface of the Ni layer formed in (1) with water and pickling, a Cr layer of 11 μg / dm ² deposited on the Ni layer on a continuous roll-to-roll plating line. It was made to adhere by carrying out an electrolytic chromate process on condition of the following.
Potassium dichromate 1 to 10 g / L, zinc 0 g / L
pH: 7 to 10
Liquid temperature: 40 to 60 ° C
Current density: 2A / dm ²
<Ultra-thin copper layer>
Next, after washing and pickling the surface of the Cr layer formed in (2), a 1.5 μm-thick ultra-thin copper layer is subsequently formed on the Cr layer on a roll-to-roll continuous plating line It formed by electroplating on condition of the following, and produced the copper foil with a carrier.
Copper concentration: 90 to 110 g / L
Sulfuric acid concentration: 90 to 110 g / L
Chloride ion concentration: 50 to 90 ppm
Leveling agent 1 (bis (3 sulfopropyl) disulfide): 10 to 30 ppm
Leveling agent 2 (amine compound): 10 to 30 ppm
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 hydroxyalkyl group, ether group, aryl group, aromatic substituted alkyl group, unsaturated hydrocarbon group, alkyl group.)
Electrolyte temperature: 50-80 ° C
Current density: 100A / dm ²
Electrolyte linear velocity: 1.5 to 5 m / sec

Example 9
<Middle class>
(1) Ni-Mo layer (nickel-molybdenum alloy plating)
The carrier was electroplated on a continuous roll-to-roll plating line under the following conditions to form a Ni-Mo layer with a loading of 3000 μg / dm ² . Specific plating conditions are described below.
(Liquid composition) Nitric acid 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 <very thin copper layer>
An ultra-thin copper layer was formed on the Ni-Mo layer formed in (1). The 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
<Middle class>
(1) Ni layer (Ni plating)
A Ni layer was formed under the same conditions as in Example 8.
(2) Organic matter layer (organic matter layer formation processing)
Next, the surface of the Ni layer formed in (1) is washed with water and acid, and subsequently, the solution temperature contains 1 to 30 g / L of carboxybenzotriazole (CBTA) to the surface of the Ni layer under the following conditions The organic layer was formed by showering and spraying an aqueous solution at 40 ° C. and pH 5 for 20 to 120 seconds.
<Ultra-thin copper layer>
An ultrathin copper layer was formed on the organic layer formed in (2). The 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
<Middle class>
(1) Co-Mo layer (cobalt molybdenum alloy plating)
The carrier was electroplated on a continuous roll-to-roll plating line under the following conditions to form a Co-Mo layer with a loading of 4000 μg / dm ² . Specific plating conditions are described below.
(Liquid composition) sulfuric acid Co: 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 <very thin copper layer>
An ultra-thin copper layer was formed on the Co-Mo layer formed in (1). The ultrathin copper layer was formed under the same conditions as in Example 8 except that the thickness of the ultrathin copper layer was 5 μm.

(Examples 2 to 6 , 8 to 16 , Reference Examples 1 and 7 )
Primary particle layer on rolled copper foil (Examples 2-6 , 12-16 , Reference Examples 1, 7 ) or ultrathin copper layer surface (Examples 8-11) of copper foil with carrier in the condition range shown below (Cu), secondary 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 15 g / L, sulfuric acid 75 g / L
Liquid temperature: 25-30 ° C
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: 15 g / L of copper, 8 g / L of nickel, 8 g / L of cobalt
pH: 2
Liquid temperature: 40 ° C
Current density: 10 to 50 A / dm ²
Coulomb amount: 10 to 80 As / dm ²

  The color tone is gray or black by adjusting 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), and the color difference system according to JIS Z8730 is rough. The color difference Δa * value with white when the color difference of the surface to be treated 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 aforementioned LabiniScan XE Plus color difference meter manufactured by HunterLab.

(Comparative Examples 1 to 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 15 g / L, sulfuric acid 75 g / L
Liquid temperature: 25 to 35 ° C
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: 15 g / L of copper, 8 g / L of nickel, 8 g / L of cobalt
pH: 2
Liquid temperature: 40 ° C
Current density: 20 to 50 A / dm ²
Coulomb amount: 30 to 80 As / dm ²

<Surface treatment layer other than primary particle layer and secondary particle layer>
After 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, Comparative Examples 1 to 5)
・ Co-Ni plating: cobalt nickel alloy plating solution composition: nickel 5 to 20 g / L, cobalt 1 to 8 g / L
pH: 2 to 3
Liquid temperature: 40 to 60 ° C
Current density: 5 to 20 A / dm ²
Coulomb amount: 10 to 20 As / dm ²

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

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

(Example 12)
・ Ni-Mo plating: Nickel-molybdenum alloy plating solution 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 to 40 ° C
Current density: 1 to 4 A / dm ²
Coulomb amount: 1 to ^{2 As} / dm ²
In Example 12, electrolytic chromate treatment was performed after Ni-Mo plating.

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

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

(Example 15)
・ Ni-W plating: Nickel tungsten alloy plating solution composition: Nickel 2 to 30 g / L, W 0.01 to 5 g / L
pH: 3 to 4
Liquid temperature: 30 to 50 ° C
Current density: 1 to ^{2 A} / dm ²
Coulomb amount: 1 to ^{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 80 mass% of Ni and 20 mass% of Cr.
Target: Ni: 80 mass%, Cr: 20 mass%
Equipment: Sputtering equipment manufactured by ULVAC, Inc. Output: DC 50 W
Argon pressure: 0.2 Pa

Average particle diameter of primary particles and 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 according to the above embodiment are formed Table 1 shows the results of measurement of color differences Δa *, Δb *, ΔL * from white when diameter, powder loss, peel strength, heat resistance, and color difference on the roughened surface were measured. Here, the “roughened surface” measured was taken as the outermost surface on which the primary particle layer and the secondary particle layer were formed. In addition, those in which surface treatment layers other than the primary particle layer and the secondary particle layer, such as Co-Ni plating, Ni-Zn plating, chromate layer, and silane coupling layer, are formed on the secondary particle layer, The surface of the outermost layer of these layers was measured as the roughened surface (that is, the surface on which the primary particle layer and the secondary particle layer were present after all surface treated layers of the copper foil were formed) It was measured).
The average particle diameter of the primary particles and secondary particles of the roughened surface was obtained by particle observation and photography at a magnification of 30,000 using S4700 (scanning electron microscope) manufactured by Hitachi High-Technologies Corporation. The particle size of each primary particle and secondary particle was measured based on the photograph. And the arithmetic mean 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. When a straight line was drawn on the particle of the scanning electron micrograph, the particle length of the portion where the length of the straight line across the particle was the longest was taken as the particle diameter of the particle. The size of the measurement field of view was 13.44 μm ² (= 4.2 μm × 3.2 μm) per one field of view, and measurement was performed for one field of view. In addition, when it observes with a scanning electron microscope picture, it is the particle which appears overlapping and exists on the copper foil side (downward), and the particle which does not overlap as primary particles, and it is the particle which appears overlapping and others The particles present on top of the particles were determined as secondary particles. The powder-falling property is based on the fact that the tape is discolored due to the falling-off roughening particles adhering to the adhesive surface of the tape when the transparent mending tape is stuck on the roughened surface of the copper foil and the tape is peeled off. Was evaluated. That is, no or slight discoloration of the tape was regarded as powdering OK, and powdering with a gray color was regarded as powdering NG. For normal peel strength, a copper-clad laminate is produced by bonding the copper foil roughened surface and the resin substrate described in Table 1 with a heat press, and a 10 mm circuit is produced using a common copper chloride circuit etching solution. Then, 10 mm circuit copper foil was peeled from the substrate, and the normal peel strength was measured while pulling in the direction of 90 °.

(Measurement of transmission loss)
Each sample of 18 μm thickness was bonded to the resin substrate described in Table 1 (LCP: liquid crystal polymer resin (Vecstar CTZ-50 μm manufactured by Kuraray Co., Ltd.), polyimide: 50 μm thick by Kaneka, 50 μm thick fluorocarbon resin: 50 μm thick) After that, a microstrip line was formed by etching so that the characteristic impedance was 50Ω, and the transmission coefficient was measured using a network analyzer HP8720C manufactured by HP, and the transmission loss at a frequency of 20 GHz and a frequency of 40 GHz was determined. In Examples 8 to 11, after the surface of the copper foil with a carrier on the very thin copper layer side is bonded to the resin substrate described in Table 1, the carrier is peeled off, and then copper plating is performed. After the total thickness of the copper layer and the copper plating was 18 μm, the same transmission loss measurement as described above was performed. As evaluation of the transmission loss at a frequency of 20 GHz, 、 for less than 3.7 dB / 10 cm, ○ for more than 3.7 dB / 10 cm and less than 4.1 dB / 10 cm, and Δ for less than 4.1 dB / 10 cm and less than 5.0 dB / 10 cm. 5.0 dB / 10 cm or more was considered as x.

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

As apparent from Table 1, the results of the examples of the present invention are as follows.
In Reference Example 1, when the current densities for forming the primary particles are 65 A / dm ² and 20 A / dm ² , and the coulomb amounts are 80 As / dm ² and 30 As / dm ² , the current density for forming the secondary particles is In this case, 28 A / dm ² and the coulomb amount are 20 As / dm ² .
In addition, although the current density and the amount of coulombs which form primary particle | grains become 2 steps, when forming a primary particle, two steps of electroplating are needed normally. That is, the plating conditions for the formation of core particles in the first stage and the electroplating for the growth of core particles in the second stage.
The first plating conditions are the electroplating conditions for the first stage nucleation particle formation, and the next plating conditions are the electroplating conditions for the second stage nucleation particle growth. The same applies to the following examples and comparative examples, so the description will be omitted.
As a result, the average particle size of the primary particles was 0.45 μm, the average particle size of the secondary particles was 0.30 μm, and the color of the surface after particle formation was gray. When the color difference on the roughened surface was measured, the color difference Δa * with white 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 loss, 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 normal peel measurement was measured and the difference was taken as the deterioration rate) Was as small as 30% or less.
In addition, the heat resistant deterioration rate was calculated | required by the following formula.
Thermal degradation rate (%) = (Peel strength in normal state (kg / cm)-Peel strength after heating at 180 ° C for 48 hours (kg / cm)) / Normal peel strength (kg / cm) × 100

In Example 2, when the current densities for forming the primary particles are 65 A / dm ² and 2 A / dm ² and the coulomb amounts are 80 As / dm ² and 4 As / dm ² , the current density for forming the secondary particles is In this case, 25 A / dm ² is used, and the coulomb amount is 15 As / dm ² .
As a result, the average particle size of the primary particles was 0.40 μm, the average particle size of the secondary particles was 0.15 μm, and the color of the surface after particle formation became gray. When the color difference on the roughened surface was measured, the color difference Δa * with white was 3.58, Δb * was 1.98, and ΔL * was −48.05, which satisfied the conditions of the present invention. As a result, no powder was removed, 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 normal peel measurement was measured and the difference was taken as the deterioration rate) Was as small as 30% or less.

In Example 3, the current density for forming the secondary particles is set to 60A / dm ² and 10A / dm ² , and the coulomb amount is set to 80As / dm ² and 20As / dm ² for forming the primary particles. In this case, 25 A / dm ² is used, and the coulomb amount is 30 As / dm ² .
As a result, the average particle size of the primary particles was 0.30 μm, the average particle size of the secondary particles was 0.25 μm, and the color of the surface after particle formation was gray. When the color difference on the roughened surface was measured, the color difference Δa * with white was 2.73, Δb * was 1.97, and ΔL * was −40.63, which satisfied the conditions of the present invention. There was no powdering. Normal peel strength is as high as 0.92 kg / cm, and heat resistance deterioration rate (The peel strength after heating at 180 ° C for 48 hours after normal peel measurement is taken as the deterioration rate is as low as 30% or less) It had the feature of.

In Example 4, the current density for forming the primary particles is 55 A / dm ² and 1 A / dm ² , and the Coulomb amount is 75 As / dm ² and 5 As / dm ^2, and the current density for forming the secondary particles is In this case, 25 A / dm ² is used, and the coulomb amount is 30 As / dm ² .
As a result, the average particle size of the primary particles was 0.35 μm, the average particle size of the secondary particles was 0.25 μm, and the color of the surface after particle formation was gray. When the color difference on the roughened surface was measured, the color difference Δa * with white was 2.22, Δb * was 1.53, and ΔL * was −48.98, which satisfied the conditions of the present invention. There is no powder removal, and the normal peel strength is as high as 0.94 kg / cm, and the heat resistance deterioration rate (the peel strength after heating at 180 ° C for 48 hours after normal peel measurement is taken as the deterioration rate) is 30% It had the feature of being small with the following.

In Example 5, the current density for forming the primary particles is 50 A / dm ² and 5 A / dm ² , and the Coulomb amount is 70 As / dm ² and 10 As / dm ^2, and the current density for forming the secondary particles is In this case, 25 A / dm ² is used, and the coulomb amount is 30 As / dm ² . Moreover, the Ni-Zn plating process layer was provided as a heat-resistant process layer on the secondary particle layer, and the electrolytic chromate process and the silane coupling process were performed after that.
As a result, the average particle size of the primary particles was 0.30 μm, the average particle size of the secondary particles was 0.25 μm, and the color of the surface after particle formation was gray. When the color difference on the roughened surface was measured, the color difference Δa * with white was 3.73 and Δb * was 2.4 and ΔL * was −47.31, which satisfied the conditions of the present invention. There is no powder removal, and the normal peel strength is as high as 0.94 kg / cm, and the heat resistance deterioration rate (the peel strength after heating at 180 ° C for 48 hours after normal peel measurement is taken as the deterioration rate) is 30% It had the feature of being small with the following.

In Example 6, the current density for forming the primary particles is 50 A / dm ² and 2 A / dm ² , and the Coulomb amount is 70 As / dm ² and 3 As / dm ^2, and the current density for forming the secondary particles is The case is 15 A / dm ² and the coulomb amount is 30 As / dm ² .
As a result, when the average particle size of the primary particles is 0.25 μm, the secondary particles are almost covered (normally) plated (particle size is less than 0.1 μm), and the color of the surface after particle formation is gray. When the color difference on the roughened surface was measured, the color difference Δa * with white was 2.75, Δb * was 3.38, and ΔL * was −33.48, which satisfied the conditions of the present invention. There is no powder removal, and the normal peel strength is as high as 0.81 kg / cm, and the heat resistance deterioration rate (the peel strength after heating at 180 ° C for 48 hours after normal peel measurement is taken as the deterioration rate) is 30% It had the feature of being small with the following.

Reference Example 7 is a secondary particle (secondary particle layer) when the current density for forming primary particles is 60 A / dm ² and 15 A / dm ² , and the coulomb amount is 80 As / dm ² and 20 As / dm ^2. and 20A / dm ² current density for forming a coulomb quantity after plating (normal plating) covering the 60As / dm ^2, further current density was 20A / dm ^2, forming a particle as coulombs 20AS / dm ² It is the case.
As a result, the primary particles have an average particle size of 0.35 μm, and the secondary particles are covered (normally) in a two-step configuration with a plated state (particle size less than 0.1 μm) and an average particle size of 0.15 μm. The color of the surface became gray. When the color difference on the roughened surface was measured, the color difference Δa * with white was 2.09, Δb * was 2.05, and ΔL * was −38.54, which satisfied the conditions of the present invention. There is no powder removal, and the normal peel strength is as high as 0.83 kg / cm, and the heat resistance deterioration rate (the peel strength after heating at 180 ° C for 48 hours after normal peel measurement is measured as the deterioration rate) is 30% It had the feature of being small with the following.

In Example 8, the current density for forming the primary particles is 65 A / dm ² and 2 A / dm ² , and the Coulomb amount is 80 As / dm ² and 4 As / dm ^2, and the current density for forming the secondary particles is In this case, 25 A / dm ² is used, and the coulomb amount is 15 As / dm ² .
As a result, the average particle size of the primary particles was 0.41 μm, the average particle size of the secondary particles was 0.16 μm, and the color of the surface after particle formation was gray. When the color difference on the roughened surface was measured, the color difference Δa * with white was 3.62, Δb * was 2.02, and ΔL * was −48.51, which satisfied the conditions of the present invention. There is no powder removal, and the normal peel strength is as high as 1.09 kg / cm, and the heat resistance deterioration rate (the peel strength after heating at 180 ° C for 48 hours after normal peel measurement is measured as the deterioration rate) is 30% It had the feature of being small with the following.

In Example 9, the current density for forming the primary particles is 60 A / dm ² and 10 A / dm ² , and the Coulomb amount is 80 As / dm ² and 20 As / dm ^2, and the current density for forming the secondary particles is In this case, 25 A / dm ² is used, and the coulomb amount is 30 As / dm ² .
As a result, the average particle size of the primary particles was 0.31 μm, the average particle size of the secondary particles was 0.25 μm, and the color of the surface after particle formation was gray. When the color difference on the roughened surface was measured, the color difference Δa * with white was 2.72, Δb * was 1.98, and ΔL * was −40.67, which satisfied the conditions of the present invention. There is no powder removal, and the normal peel strength is as high as 0.93 kg / cm, and the heat resistance deterioration rate (the peel strength after heating at 180 ° C for 48 hours after normal peel measurement is measured as the deterioration rate) is 30% It had the feature of being small with the following.

In Example 10, when the current densities for forming the primary particles are 55 A / dm ² and 1 A / dm ² , and the coulomb amounts are 75 As / dm ² and 5 As / dm ² , the current density for forming the secondary particles is In this case, 25 A / dm ² is used, and the coulomb amount is 30 As / dm ² .
As a result, the average particle size of the primary particles was 0.35 μm, the average particle size of the secondary particles was 0.26 μm, and the color of the surface after particle formation was gray. When the color difference on the roughened surface was measured, the color difference Δa * with white was 2.22, Δb * was 1.54, and ΔL * was −48.92, which satisfied the conditions of the present invention. There is no powder removal, and the normal peel strength is as high as 0.95 kg / cm, and the heat resistance deterioration rate (the peel strength after heating at 180 ° C for 48 hours after normal peel measurement is measured as the deterioration rate) is 30% It had the feature of being small with the following.

In Example 11, the current density for forming the primary particles is 50 A / dm ² and 5 A / dm ² , and the Coulomb amount is 70 As / dm ² and 10 As / dm ^2, and the current density for forming the secondary particles is In this case, 25 A / dm ² is used, and the coulomb amount is 30 As / dm ² .
As a result, the average particle size of the primary particles was 0.30 μm, the average particle size of the secondary particles was 0.25 μm, and the color of the surface after particle formation was gray. When the color difference on the roughened surface was measured, the color difference Δa * with white was 3.72, Δb * was 2.39, and ΔL * was −47.33, which satisfied the conditions of the present invention. There is no powder removal, and the normal peel strength is as high as 0.94 kg / cm, and the heat resistance deterioration rate (the peel strength after heating at 180 ° C for 48 hours after normal peel measurement is taken as the deterioration rate) is 30% It had the feature of being small with the following.

In Example 12, the current density for forming the primary particles is 60 A / dm ² and 10 A / dm ² , and the Coulomb amount is 80 As / dm ² and 20 As / dm ^2. In this case, 25 A / dm ² is used, and the coulomb amount is 30 As / dm ² .
As a result, the average particle size of the primary particles was 0.30 μm, the average particle size of the secondary particles was 0.25 μm, and the color of the surface after particle formation was gray. When the color difference on the roughened surface was measured, the color difference Δa * with white was 2.74, Δb * was 1.98, and ΔL * was −40.67, which satisfied the conditions of the present invention. There is no powder removal, and the normal peel strength is as high as 0.93 kg / cm, and the heat resistance deterioration rate (the peel strength after heating at 180 ° C for 48 hours after normal peel measurement is measured as the deterioration rate) is 30% It had the feature of being small with the following.

In Example 13, the current density for forming the primary particles is 60 A / dm ² and 10 A / dm ² , and the Coulomb amount is 80 As / dm ² and 20 As / dm ^2, and the current density for forming the secondary particles is In this case, 25 A / dm ² is used, and the coulomb amount is 30 As / dm ² .
As a result, the average particle size of the primary particles was 0.30 μm, the average particle size of the secondary particles was 0.25 μm, and the color of the surface after particle formation was gray. When the color difference on the roughened surface was measured, the color difference Δa * with white was 2.73, Δb * was 1.98, and ΔL * was −40.50, which satisfied the conditions of the present invention. There is no powder removal, and 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 normal peel measurement is taken as the deterioration rate) is 30% It had the feature of being small with the following.

In Example 14, when the current densities for forming the primary particles are 55 A / dm ² and 1 A / dm ² , and the coulomb amounts are 75 As / dm ² and 5 As / dm ² , the current densities for forming the secondary particles are In this case, 25 A / dm ² is used, and the coulomb amount is 30 As / dm ² .
As a result, the average particle size of the primary particles was 0.35 μm, the average particle size of the secondary particles was 0.25 μm, and the color of the surface after particle formation was gray. When the color difference on the roughened surface was measured, the color difference Δa * with white was 2.23, Δb * was 1.52, and ΔL * was −48.95, which satisfied the conditions of the present invention. There is no powder removal, and the normal peel strength is as high as 0.94 kg / cm, and the heat resistance deterioration rate (the peel strength after heating at 180 ° C for 48 hours after normal peel measurement is taken as the deterioration rate) is 30% It had the feature of being small with the following.

In Example 15, the current density for forming the primary particles is 50 A / dm ² and 5 A / dm ² , and the Coulomb amount is 70 As / dm ² and 10 As / dm ^2. In this case, 25 A / dm ² is used, and the coulomb amount is 30 As / dm ² .
As a result, the average particle size of the primary particles was 0.30 μm, the average particle size of the secondary particles was 0.25 μm, and the color of the surface after particle formation was gray. When the color difference on the roughened surface was measured, the color difference Δa * with white was 3.70, Δb * was 2.38, and ΔL * was −49.49, which satisfied the conditions of the present invention. There is no powder removal, and the normal peel strength is as high as 0.94 kg / cm, and the heat resistance deterioration rate (the peel strength after heating at 180 ° C for 48 hours after normal peel measurement is taken as the deterioration rate) is 30% It had the feature of being small with the following.

In Example 16, the current density for forming the primary particles is 50 A / dm ² and 2 A / dm ² , and the Coulomb amount is 70 As / dm ² and 3 As / dm ^2, and the current density for forming the secondary particles is The case is 15 A / dm ² and the coulomb amount is 30 As / dm ² .
As a result, when the average particle size of the primary particles is 0.25 μm, the secondary particles are almost covered (normally) plated (particle size is less than 0.1 μm), and the color of the surface after particle formation is gray. When the color difference on the roughened surface was measured, the color difference Δa * with white was 2.76, Δb * was 3.39, and ΔL * was −33.60, which satisfied the conditions of the present invention. There is no powder removal, and the normal peel strength is as high as 0.81 kg / cm, and the heat resistance deterioration rate (the peel strength after heating at 180 ° C for 48 hours after normal peel measurement is taken as the deterioration rate) is 30% It had the feature of being small with the following.

On the other hand, the comparative example has the following results.
In Comparative Example 1, when the current densities for forming the primary particles are 63 A / dm ² and 10 A / dm ² and the coulomb amounts are 80 As / dm ² and 30 As / dm ² , no secondary particles are 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 particle formation was red. When the color difference on the roughened surface was measured, the color difference Δa * from white 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 loss.
The normal peel strength was as high as 1.38 kg / cm, which was an example level, but the heat resistance deterioration rate (the peel strength after heating at 180 ° C for 48 hours after normal peel measurement was measured, and the difference between them was taken as the deterioration rate) was It was extremely bad at 60%. Evaluation as the whole copper foil for high frequency circuits was unsatisfactory.

Comparative Example 2 shows a conventional example in which only the secondary particle layer does not have a primary particle diameter. 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 the particle formation was black. When the color difference on the roughened surface was measured, the color difference Δa * with 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 powdering occurred.
Implemented 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 is measured after normal state peel measurement and the difference is regarded as the deterioration rate) is 30% or less It was an example level. As described above, the overall evaluation as a copper foil for high frequency circuits is poor because of the problem that a large amount of powdering occurs.

In Comparative Example 3, when the current density for forming primary particles is 63 A / dm ² and 1 A / dm ² , and the coulomb amount is 80 As / dm ² and ² As / dm ² , the current density for forming secondary particles is In this case, 28 A / dm ² and the coulomb amount are 73 As / dm ² .
As a result, the average particle size of the primary particles was 0.35 μm, the average particle size of the secondary particles was 0.60 μm, and the color tone of the surface after particle formation was gray. When the color difference on the roughened surface was measured, the color difference Δa * with white was 4.88, Δb * was 2.34 and ΔL * was −56.08, which deviated from the scope of the present invention. A lot of powdering occurred. Normal peel strength is as high as 1.42 kg / cm, and heat resistance deterioration rate (when the peel strength after heating at 180 ° C for 48 hours is measured after normal state peel measurement and the difference is regarded as the deterioration rate) is 30% or less It was an example level. The evaluation as the entire copper foil for high frequency circuits was poor because a large amount of powdering occurred.

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

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

In Comparative Example 6, when the current density for forming primary particles is 40 A / dm ² and 1 A / dm ² , and the coulomb amount is 40 As / dm ² and ² As / dm ² , the current density for forming secondary particles is The case is 20 A / dm ² and the coulomb amount is 20 As / dm ² .
As a result, the average particle size of the primary particles was 0.15 μm, the average particle size of the secondary particles was 0.15 μm, and the color tone of the surface after particle formation was light gray. When the color difference on the roughened surface was measured, the color difference Δa * with white was 1.85, Δb * was 4.15, and ΔL * was −36.42, which deviated from the scope of the present invention. It is considered that the secondary particles are light gray and the color difference is small because the primary particles are small while the secondary particles are also the same size.
Powdering did not occur. In addition, 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 normal peel measurement was determined as the deterioration rate) was 35%. .

As apparent from the comparison between the above-mentioned Examples and Comparative Examples, after forming a primary particle layer of copper on the surface of a copper foil (original foil), 3 consisting of copper, cobalt and nickel on the primary particle layer 3 In the case of forming a secondary particle layer made of a source alloy, the color tone is gray or black, and the color difference Δa * value with the white when the color difference on the roughened surface is measured in the color difference system described in JIS Z8730 is 4 .0 or less, and the color difference .DELTA.b * value of 3.5 or less has an excellent effect of being able to stably suppress the phenomenon said to be powder falling, and further enhances the 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 of copper, cobalt and nickel is 0.35 μm or less. It is more effective in achieving the effect of
Further, setting the value of the color difference ΔL to -30 to -50 is more effective in achieving the above-mentioned effects.
In the case where the heat-resistant layer contains Co, the transmission loss tends to be large.

Claims (17)

A copper foil in which a primary particle layer containing copper is formed on the surface of a copper foil, and then a secondary particle layer containing a ternary alloy consisting of copper, cobalt and nickel is formed on the primary particle layer, The color difference Δa * value with white when the color difference of the roughened surface is measured in the color difference system according to JIS Z 8730 is 2.22 to 3.73, and the color difference Δb * value is 1.52 to 3.39,
The color difference ΔL * value with white when the color difference of the roughened surface is measured in the color difference system is -30 to -50,
The average particle size of the primary particle layer is 0.25 to 0.45 μm, and the average particle size of the secondary particle layer is 0.35 μm or less,
The copper foil for high frequency circuits over 1 GHz whose said primary particle layer and secondary particle layer are electroplating layers. The copper foil for high frequency circuits according to claim 1, wherein the secondary particles are one or more dendritic particles grown on the primary particles or a normal plating layer grown on the primary particles. On the secondary particle layer,
(A) 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;
The copper foil for high frequency circuits according to claim 1 or 2, wherein one or both of (B) chromate layers are formed. On the secondary particle layer,
(A) 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;
(B) either one or both of the chromate layers,
The copper foil for high frequency circuits as described in any one of Claims 1-3 with which the silane coupling layer was formed in this order. On the secondary particle layer,
The copper foil for high frequency circuits as described in any one of Claims 1-4 in which any one or both of a Ni-Zn alloy layer and a chromate layer were formed. On the secondary particle layer,
Either or both of a Ni-Zn alloy layer and a chromate layer;
The copper foil for high frequency circuits as described in any one of Claims 1-5 with which the silane coupling layer was formed in this order. The copper foil for high frequency circuits according to claim 1 or 2, wherein a resin layer is provided on the surface of the secondary particle layer. An alloy layer comprising the 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 3-6 provided with the resin layer on the surface of the layer, 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 one side or both sides of a carrier, Comprising: The said ultra-thin copper layer was described in any one of Claims 1-8. Copper foil with a carrier, which is a copper foil for high frequency circuits .   The copper foil with carrier according to claim 9, wherein the intermediate layer and the ultrathin copper layer are provided in this order on one side of the carrier, and a roughened layer is provided on the other side of the carrier. The copper clad laminated board for high frequency circuits using the copper foil as described in any one of Claims 1-10. The printed wiring board for high frequency circuits using the copper foil as described in any one of Claims 1-10. The copper-clad laminate for high frequency circuits according to claim 11, wherein the copper foil and a polyimide, a liquid crystal polymer or a fluorine resin are laminated. The printed wiring board for high frequency circuits according to claim 12, wherein any one of polyimide, a liquid crystal polymer and a fluorine resin is used.   An electronic device using the printed wiring board according to claim 12 or 14. A step of preparing the copper foil with carrier according to claim 9 and an insulating substrate,
Laminating the copper foil with carrier and the insulating substrate;
After laminating the copper foil with carrier and the insulating substrate, a copper-clad laminate is formed through a step of peeling the carrier of the copper foil with carrier.
And then forming a circuit by any of a semi-additive method, a subtractive method, a partial additive method or a modified semi-additive method. A process of forming a circuit on the ultrathin copper layer side surface of the copper foil with a carrier according to claim 9 or 10,
Forming a resin layer on the very thin copper layer side surface of the copper foil with carrier so that the circuit is buried;
Forming a circuit on the resin layer;
Separating the carrier after forming a circuit on the resin layer;
A process for producing a printed wiring board including the step of exposing a circuit embedded in the resin layer formed on the surface of the ultrathin copper layer by removing the ultrathin copper layer after peeling off the carrier. Method.