JP5814168B2 - Copper foil with carrier - Google Patents

Description

  The present invention relates to a copper foil with a carrier. In more detail, this invention relates to the copper foil with a carrier used as a material of the printed wiring board for a fine pattern use.

  Printed wiring boards have made great progress over the last half century and are now used in almost all electronic devices. In recent years, with the increasing demand for miniaturization and high performance of electronic devices, higher density mounting of components and higher frequency of signals have progressed, and conductor patterns have become finer (fine pitch) and printed circuit boards. There is a demand for high frequency response, and in particular, when an IC chip is mounted on a printed wiring board, a fine pitch of L / S = 20/20 or less is required.

  A printed wiring board is first manufactured as a copper clad laminate in which an insulating substrate mainly composed of a copper foil and a glass epoxy substrate, a BT resin, a polyimide film, or the like is bonded. Bonding is performed by laminating an insulating substrate and a copper foil and applying heat and pressure (laminating method), or by applying a varnish that is a precursor of an insulating substrate material to a surface having a coating layer of copper foil, A heating / curing method (casting method) is used.

  Along with the fine pitch, the thickness of the copper foil used for the copper clad laminate is also 9 μm, and further, 5 μm or less. However, when the foil thickness is 9 μm or less, the handleability when forming a copper clad laminate by the above-described lamination method or casting method is extremely deteriorated. Therefore, a copper foil with a carrier has appeared, in which a thick metal foil is used as a carrier, and an ultrathin copper layer is formed on the metal foil via a release layer. A general method of using a copper foil with a carrier is to peel the carrier through a release layer after the surface of the ultrathin copper layer is bonded to an insulating substrate and thermocompression bonded.

  As a technique related to a copper foil with a carrier, for example, in Patent Document 1, a diffusion prevention layer, a release layer, and an electrolytic copper plating are formed in this order on the surface of a carrier, and a Cr or Cr hydrated oxide layer is formed as a release layer. A method for maintaining good peelability after hot pressing by using a simple substance or an alloy of Ni, Co, Fe, Cr, Mo, Ta, Cu, Al, P as a diffusion preventing layer is disclosed.

  Further, it is known that the release layer is formed of Cr, Ni, Co, Fe, Mo, Ti, W, P, alloys thereof, or hydrates thereof. Furthermore, Patent Documents 2 and 3 describe that it is effective to provide Ni, Fe or an alloy layer thereof as a base of the release layer in order to stabilize the peelability in a high temperature use environment such as a hot press. Has been.

JP 2006-022406 A JP 2010-006071 A JP 2007-007937 A

  In copper foil with carrier, the ultra-thin copper layer must not be easily peeled off from the carrier before the lamination process on the insulating substrate, while the carrier is easily removed from the ultra-thin copper layer after the lamination process on the insulating substrate. It is necessary to peel off. In addition, after peeling the carrier from the ultrathin copper layer after the lamination process to the insulating substrate, the surface of the ultrathin copper layer is exposed to the atmosphere for a while, so it is necessary to ensure sufficient corrosion resistance of the surface of the ultrathin copper layer. .

  On the other hand, Patent Document 1 shows good peelability after hot pressing, but does not mention the state of the ultrathin copper layer surface. In addition, in Patent Documents 2 and 3, there is no description that can be considered that characteristics such as peel strength between the carrier / ultra-thin copper layer have been sufficiently examined, and there is still room for improvement.

  Therefore, in the present invention, the adhesion between the carrier and the ultrathin copper layer is high before the lamination process to the insulating substrate, while the adhesion between the carrier and the ultrathin copper layer is lowered after the lamination process to the insulation substrate. An object of the present invention is to provide a copper foil with a carrier that can be easily peeled off at the carrier / ultra-thin copper layer interface and has excellent corrosion resistance on the surface of the ultra-thin copper layer after peeling off the carrier.

  In order to achieve the above object, the present inventor conducted extensive research and used copper foil as a carrier, formed an intermediate layer between the ultrathin copper layer and the carrier, and formed an insulating substrate on the ultrathin copper layer. It is extremely effective to control the ratio of the atomic concentration of chromium or nickel to the concentration of specified atoms present on the surface of the ultrathin copper layer when the carrier is peeled off from the ultrathin copper layer. I found.

The present invention has been completed on the basis of the above knowledge, and in one aspect, includes a copper foil carrier, an intermediate layer laminated on the copper foil carrier, and an ultrathin copper layer laminated on the intermediate layer. Copper foil with a carrier,
The intermediate layer is configured by laminating a chromium layer or a chromate layer, and a nickel layer or a nickel-phosphorus alloy layer in this order on the copper foil carrier,
The adhesion amount of nickel in the intermediate layer is 1000 to 40000 μg / dm ² , the adhesion amount of nickel-phosphorous alloy is 1000 to 40000 μg / dm ² , and the adhesion amount of chromium is 10 to 1000 μg / dm ² ,
When the copper foil carrier was peeled from the ultrathin copper layer, the atomic concentration (%) of chromium in the depth direction (x: unit nm) obtained from the depth direction analysis from the surface by XPS was expressed as f (x ), The atomic concentration (%) of nickel is g (x), the atomic concentration (%) of copper is h (x), the total atomic concentration (%) of phosphorus is i (x), and the atomic concentration of carbon (%) Is j (x), oxygen atomic concentration (%) is k (x), and other atomic concentration (%) is l (x).
In the section [0, 3.0] of the depth direction analysis from the surface of the ultrathin copper layer, ∫f (x) dx / (∫f (x) dx + ∫g (x) dx + ∫h (x) dx + ∫i (x) dx + ∫j (x) dx + ∫k (x) dx + ∫l (x) dx) is 3% or less, ∫g (x) dx / (∫f (x) dx +付 g (x) dx + ∫h (x) dx + ∫i (x) dx + ∫j (x) dx + ∫k (x) dx + ∫l (x) dx) with copper satisfying 40% or more It is a foil.

  In one embodiment of the carrier-attached copper foil according to the present invention, when the copper foil carrier is peeled from the ultrathin copper layer, the depth direction analysis section [0, 3.0 from the ultrathin layer surface is used. ] ∫h (x) dx / (∫f (x) dx + ∫g (x) dx + ∫h (x) dx + ∫i (x) dx + ∫j (x) dx + ∫k (x) dx + ∫l (x) dx) is 1 to 20%.

In another embodiment of the copper foil with a carrier according to the present invention, an insulating substrate is thermocompression bonded to the ultrathin copper layer under the conditions of 20 kgf / cm ² pressure and 195 ° C. × 2 hours in the atmosphere. When peeling the foil carrier from the ultra-thin copper layer,
The atomic concentration (%) of chromium in the depth direction (x: nm) obtained from XPS depth direction analysis is f (x), and the atomic concentration (%) of nickel is g (x). , The atomic concentration (%) of copper is h (x), the total atomic concentration (%) of phosphorus is i (x), the atomic concentration (%) of carbon is j (x), and the atomic concentration of oxygen (%) ) Is k (x) and other atomic concentrations (%) are l (x)
In the section [0, 3.0] of the depth direction analysis from the surface of the ultrathin copper layer, ∫f (x) dx / (∫f (x) dx + ∫g (x) dx + ∫h (x) dx + ∫i (x) dx + ∫j (x) dx + ∫k (x) dx + ∫l (x) dx) is 5% or less, ∫g (x) dx / (∫f (x) dx + ∫g (x) dx + ∫h (x) dx + ∫i (x) dx + ∫j (x) dx + ∫k (x) dx + ∫l (x) dx) satisfies 40% or more.

In yet another embodiment of the copper foil with a carrier according to the present invention, the insulating substrate is thermocompression bonded to the ultrathin copper layer under the conditions of pressure of 20 kgf / cm ² and 195 ° C. × 2 hours in the atmosphere, When peeling the copper foil carrier from the ultra-thin copper layer,
In the interval [0, 3.0] of the depth direction analysis from the surface of the ultrathin layer, ∫h (x) dx / (∫f (x) dx + ∫g (x) dx + ∫h (x) dx + ∫i (x) dx + ∫j (x) dx + ∫k (x) dx + ∫l (x) dx) is 1 to 30%.

  In still another embodiment of the carrier-attached copper foil according to the present invention, the concentration of phosphorus in the nickel-phosphorus alloy used for the intermediate layer is 0 to 20% by mass.

  In still another embodiment of the copper foil with a carrier according to the present invention, the carrier copper foil is an electrolytic foil or a rolled copper foil.

  In still another embodiment of the copper foil with a carrier according to the present invention, the surface of the ultrathin copper layer has a roughening treatment layer.

  In still another embodiment of the copper foil with a carrier according to the present invention, the roughening treatment layer is any one selected from the group consisting of copper, nickel, cobalt and zinc, or any one or more. It is a layer made of an alloy containing.

  In still another embodiment of the copper foil with a carrier according to the present invention, one or more types selected from the group consisting of a rust prevention layer, a chromate treatment layer and a silane coupling treatment layer on the surface of the roughening treatment layer. It has a layer of.

  In still another embodiment of the copper foil with a carrier according to the present invention, one or more selected from the group consisting of a rust prevention layer, a chromate treatment layer and a silane coupling treatment layer on the surface of the ultrathin copper layer. It has a layer of.

  In another aspect of the present invention, a chromium layer or a chromate layer is formed on a copper foil carrier by physical vapor deposition or electroplating, and a nickel layer or a nickel-phosphorus alloy layer is formed on the chromium layer or the chromate layer. It is a manufacturing method of copper foil with a carrier including the process of forming an intermediate | middle layer by forming, and the process of forming an ultra-thin copper layer on the said intermediate | middle layer by electrolytic plating.

  The manufacturing method of the copper foil with a carrier of this invention in one Embodiment further includes the process of forming a roughening process layer on the said ultra-thin copper layer.

  The copper foil with a carrier according to the present invention has high adhesion between the carrier and the ultrathin copper layer before the lamination process to the insulating substrate, while the carrier and the ultrathin copper layer after the lamination process to the insulation substrate. Adhesiveness is lowered and can be easily peeled off at the carrier / ultra thin copper layer interface. Moreover, the copper foil with a carrier which concerns on this invention has favorable corrosion resistance of the ultra-thin copper layer surface after peeling off a carrier.

It is the XPS depth profile of the depth direction of the ultra-thin copper layer surface before board | substrate bonding of Example 2. FIG. It is the SEM photograph which image | photographed the circuit which peeled the copper foil carrier after Example 2 was thermocompression bonded with the board | substrate, and etched the ultra-thin copper layer from the upper surface.

<1. Career>
A copper foil is used as a carrier that can be used in the present invention. The carrier is typically provided in the form of rolled copper foil or electrolytic copper foil. In general, the electrolytic copper foil is produced by electrolytic deposition of copper from a copper sulfate plating bath onto a drum of titanium or stainless steel, and the rolled copper foil is produced by repeating plastic working and heat treatment with a rolling roll. In addition to high-purity copper such as tough pitch copper and oxygen-free copper, the copper foil material is, for example, Sn-containing copper, Ag-containing copper, copper alloy added with Cr, Zr, Mg, etc., and Corson-based added with Ni, Si, etc. Copper alloys such as copper alloys can also be used. In addition, when the term “copper foil” is used alone in this specification, a copper alloy foil is also included.

  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, for example, 12 μm or more. However, if it is too thick, the production cost becomes high, so generally it is preferably 35 μm or less. Accordingly, the thickness of the carrier is typically 12-70 μm, more typically 18-35 μm.

<2. Intermediate layer>
An intermediate layer is provided on the copper foil carrier. The intermediate layer is preferably formed of nickel, and it is preferable that a chromate layer or a chromium layer is present between the copper foil carrier and the intermediate layer. Since Ni has a higher adhesion with Cu than Cr, it peels between the chromate layer or the chromium layer and the nickel layer. Moreover, since Cu is very easy to diffuse into Ni, an intermediate layer of Ni and a Ni—Cu alloy are formed on the surface of the ultrathin copper layer. The surface of the ultrathin copper layer on which the Ni—Cu alloy is formed has improved corrosion resistance compared to the case where Cu is present alone.
When using electrolytic copper foil as a carrier, it is preferable to provide an intermediate layer on the shiny surface from the viewpoint of reducing pinholes.

When the intermediate layer is made of nickel, it can be formed by wet plating such as electroplating, electroless plating and immersion plating, or dry plating such as sputtering, CVD and PDV. Electroplating is preferable from the viewpoint of cost.
Further, the chromate layer or the chromium layer can be formed by wet plating such as electrolytic chromate, immersion chromate, electroplating, electroless plating and immersion plating, or dry plating such as sputtering, CVD and PDV.

From the above viewpoint, in the intermediate layer, the adhesion amount of nickel is 1000 to 40000 μg / dm ² , the adhesion amount of nickel-phosphorus alloy is 1000 to 40000 μg / dm ² , and the adhesion amount of chromium is 10 to 1000 μg / dm ² . Is preferred. Although the amount of pinholes tends to increase as the amount of nickel increases, the number of pinholes is also suppressed within this range. Terms of peeling ultrathin copper layer without unevenness uniformly, and, from the viewpoint of suppressing a pinhole, nickel coating weight is preferably set to 1000~10000μg / dm ^2, be 2000~9000μg / dm ² more preferably, the chromium coating weight is preferably set to 10~500μg / dm ^2, and more preferably a 15~400μg / dm ^2.
When the nickel-phosphorus alloy is present on the surface of the ultrathin copper layer after peeling from the copper foil carrier, the corrosion resistance of the surface of the ultrathin copper layer is improved. Here, if the concentration of phosphorus exceeds 20% by mass, the corrosion resistance of the surface of the ultrathin copper layer becomes too high, and there is a risk of causing etching failure at the stage of etching to form a circuit. Therefore, it is preferable that the density | concentration of the phosphorus of the nickel- phosphorus alloy used for an intermediate | middle layer is 0-20 mass%.

<3. Ultra-thin copper layer>
An ultrathin copper layer is provided on the intermediate layer. The ultra-thin copper layer can be formed by electroplating using an electrolytic bath such as copper sulfate, copper pyrophosphate, copper sulfamate, copper cyanide, etc., and is used in general electrolytic copper foil with high current density. Since a copper foil can be formed, a copper sulfate bath is preferable. The thickness of the ultrathin copper layer is not particularly limited, but is generally thinner than the carrier, for example, 12 μm or less. It is typically 0.5-12 μm, more typically 2-5 μm.

<4. Roughening>
A roughening treatment layer may be provided on the surface of the ultrathin copper layer by performing a roughening treatment, for example, in order to improve the adhesion to the insulating substrate. The roughening treatment can be performed, for example, by forming roughened particles with copper or a copper alloy. The roughening process may be fine. The roughening treatment layer may be a single layer selected from the group consisting of copper, nickel, cobalt and zinc, or a layer made of an alloy containing one or more of them. In addition, after roughening treatment or without roughening treatment, secondary particles, tertiary particles and / or rust preventive layers are formed of nickel, cobalt, copper, zinc alone or an alloy, and further on the surface. Treatments such as chromate treatment and silane coupling treatment may be applied. That is, on the surface of the roughening treatment layer, one or more layers selected from the group consisting of a rust prevention layer, a chromate treatment layer and a silane coupling treatment layer may be formed, and on the surface of the ultrathin copper layer, You may form 1 or more types of layers selected from the group which consists of a rust prevention layer, a chromate treatment layer, and a silane coupling treatment layer.

<5. Copper foil with carrier>
Thus, the copper foil with a carrier provided with the copper foil carrier, the intermediate | middle layer formed on the copper foil carrier, and the ultra-thin copper layer laminated | stacked on the intermediate | middle layer is manufactured. The method of using the copper foil with carrier itself is well known to those skilled in the art. For example, the surface of the ultra-thin copper layer is made of paper base phenol resin, paper base epoxy resin, synthetic fiber cloth base epoxy resin, glass cloth / paper composite. Ultra-thin bonded to an insulating substrate, bonded to an insulating substrate such as a base epoxy resin, glass cloth / glass nonwoven fabric composite epoxy resin and glass cloth base epoxy resin, polyester film, polyimide film, etc. The copper layer can be etched into the intended conductor pattern to finally produce a printed wiring board. In the case of the copper foil with a carrier according to the present invention, the peeled portion is mainly the intermediate chromate layer or the interface between the chromium layer and the nickel layer.

When the copper foil with a carrier of the present invention is peeled from the ultrathin copper layer, the atomic concentration of chromium in the depth direction (x: unit nm) obtained from the depth direction analysis from the surface by XPS. (%) Is f (x), nickel atomic concentration (%) is g (x), copper atomic concentration (%) is h (x), and total atomic concentration (%) of phosphorus is i (x ), The atomic concentration (%) of carbon is j (x), the atomic concentration (%) of oxygen is k (x), and the other atomic concentration (%) is l (x). In the interval [0, 3.0] of the depth direction analysis from the surface, ∫f (x) dx / (∫f (x) dx + ∫g (x) dx + ∫h (x) dx + ∫i ( x) dx + ∫j (x) dx + ∫k (x) dx + ∫l (x) dx) is 3% or less, ∫g (x) dx / (∫f (x) dx + ∫g (x) dx + ∫h (x) dx + ∫i (x) dx + ∫j (x) dx + ∫k (x) dx + ∫l (x) dx) satisfies 40% or more.
Thus, the copper foil with a carrier of the present invention has a chromium atom concentration of 3% or less at the surface portion of the ultrathin copper layer when the copper foil carrier is peeled from the ultrathin copper layer. Etching is improved when a circuit is formed by etching. Further, since the nickel atom concentration is 40% or more, the corrosion resistance of the surface of the ultrathin copper layer after the carrier is peeled off becomes good.

  Moreover, the copper foil with a carrier of the present invention has a ∫h (x) in the interval [0, 3.0] of the depth direction analysis from the surface of the ultrathin layer when the copper foil carrier is peeled from the ultrathin copper layer. ) dx / (∫f (x) dx + ∫g (x) dx + ∫h (x) dx + ∫i (x) dx + ∫j (x) dx + ∫k (x) dx + ∫l (x) dx) is preferably 1 to 20%. According to such a structure, since the ultrathin copper foil surface after peeling a copper foil carrier becomes a nickel-copper alloy, the corrosion resistance of the ultrathin copper foil surface improves. Furthermore, since the nickel-copper alloy has better etching properties than nickel alone, the etching properties of the ultrathin copper layer are improved.

Moreover, the copper foil with a carrier of the present invention is obtained by thermocompression bonding an insulating substrate to an ultrathin copper layer under conditions of a pressure of 20 kgf / cm ² and a pressure of 195 ° C. for 2 hours. When exfoliated, the atomic concentration (%) of chromium in the depth direction (x: unit nm) obtained from XPS depth direction analysis is defined as f (x), and the atomic concentration (%) of nickel is g (x), copper atomic concentration (%) as h (x), phosphorus total atomic concentration (%) as i (x), carbon atomic concentration (%) as j (x), oxygen Assuming that the atomic concentration (%) is k (x) and the other atomic concentration (%) is l (x), in the interval [0, 3.0] of the depth direction analysis from the ultrathin copper layer surface, ∫f (x) dx / (∫f (x) dx + ∫g (x) dx + ∫h (x) dx + ∫i (x) dx + ∫j (x) dx + ∫k (x) dx + ∫ l (x) dx) is 5% or less, ∫g (x) dx / (∫f (x) dx + ∫g (x) dx + ∫h (x) dx + ∫i (x) dx + ∫j (x) dx + ∫k (x) dx + ∫l (x) dx) is 40 % Or more.
As described above, the copper foil with a carrier of the present invention is obtained by thermocompression bonding an insulating substrate to an ultrathin copper layer under the conditions of a pressure of 20 kgf / cm ² and a pressure of 195 ° C. for 2 hours. Since the chromium atom concentration in the surface portion of the ultrathin copper layer when peeled from the layer is 5% or less, the etching property when the ultrathin copper layer is etched to form a circuit is improved. Further, since the nickel atom concentration is 40% or more, the corrosion resistance of the surface of the ultrathin copper layer after the carrier is peeled off becomes good.

Moreover, the copper foil with a carrier of the present invention is obtained by thermocompression bonding an insulating substrate to an ultrathin copper layer under conditions of a pressure of 20 kgf / cm ² and a pressure of 195 ° C. for 2 hours. When exfoliated, 区間 h (x) dx / (∫f (x) dx + ∫g (x) dx + ∫h in the depth direction analysis interval [0, 3.0] from the surface of the ultrathin layer (x) dx +) i (x) dx + ∫j (x) dx + ∫k (x) dx + ∫l (x) dx) is preferably 1 to 30%. According to such a configuration, when the copper foil carrier is peeled after the insulating substrate is thermocompression bonded, the surface of the ultrathin copper foil becomes a nickel-copper alloy, so that the corrosion resistance of the surface of the ultrathin copper foil is improved. Furthermore, since the nickel-copper alloy has better etching properties than nickel alone, the etching properties of the ultrathin copper layer are improved.

  When the current density at the time of forming the chromate layer or the chromium layer is increased and the conveying speed of the carrier copper foil is decreased, the chromium concentration is increased and the chromium concentration can be controlled. The higher the current density during the nickel layer formation and the higher the electrodeposition rate per unit time, and the higher the carrier copper foil transport rate, the lower the nickel layer density and the lower the nickel concentration. When the density of the nickel layer is reduced, the copper of the ultrathin copper layer is easily diffused into the nickel layer, and the concentration of copper in the nickel can be controlled. In addition, as the amount of nickel deposited decreases, copper in the ultrathin copper layer becomes easier to diffuse into nickel, and the concentration of copper in nickel can also be controlled by this.

  In the case where the intermediate layer is formed by dry plating, the chromium concentration increases and the chromium concentration can be controlled by increasing the sputtering output at the time of forming the chromium layer and decreasing the transport speed of the carrier copper foil. The density of the nickel layer decreases as the sputtering output of nickel is set higher to increase the film formation rate per unit time, and as the conveyance speed of the carrier copper foil is increased. As the density of the nickel layer decreases, the nickel concentration decreases. Moreover, when the density of a nickel layer falls, the copper of an ultra-thin copper layer will spread | diffuse easily to a nickel layer, and the density | concentration of the copper in nickel can be controlled. In addition, as the amount of nickel deposited decreases, copper in the ultrathin copper layer becomes easier to diffuse into nickel, and the concentration of copper in nickel can also be controlled by this.

  EXAMPLES The present invention will be described in more detail below with reference to examples of the present invention, but the present invention is not limited to these examples.

1. Production of Copper Foil with Carrier A long electrolytic copper foil (JTC made by JX Nippon Mining & Metals) and a rolled copper foil (C1100 made by JX Nippon Mining & Metals) were prepared as a copper foil carrier. With respect to the shiny surface of this copper foil, the intermediate layer forming process described in Tables 1 and 2 is performed in the following conditions in order on the carrier surface and the ultrathin copper layer side in a roll-to-roll type continuous line under the following conditions. went. Washing and pickling were performed between the processing steps on the carrier surface side and the ultrathin copper layer side.

・ Ni plating Nickel sulfate: 250-300 g / L
Nickel chloride: 35 to 45 g / L
Nickel acetate: 10-20g / L
Trisodium citrate: 15-30 g / L
Brightener: Saccharin, butynediol, etc. Sodium dodecyl sulfate: 30-100 ppm
pH: 4-6
Bath temperature: 50-70 ° C
Current density: 3-15 A / dm ²

-Cr plating solution composition: chromic anhydride 200-400 g / L, sulfuric acid 1.5-4 g / L
pH: 1-4
Liquid temperature: 45-60 degreeC
Current density: 10 to 40 A / dm ²

・ Ni-P plating Nickel sulfate: 200-300 g / L
Nickel chloride: 35-50 g / L
Boric acid: 30-50 g / L
Phosphorous acid: 1-30 g / L
pH: 1-3
Bath temperature: 40-70 ° C
Current density: 3-15 A / dm ²

・ Sputtering (Ni, Cr)
Equipment: Roll toe roll type sputtering equipment (Shinko Seiki Co., Ltd.)
Ultimate vacuum: 1.0 × 10 ⁻⁵ Pa
Sputtering pressure: 0.25 Pa
Conveying speed: 15m / min
Ion gun power: 225W
Sputtering power: 200-3000W
Target: Ni, Ni-10 wt% P, Ni-20 wt% P, Cr (3N)

・ Immersion chromate treatment liquid composition (1): potassium dichromate 1-10 g / L, zinc 0-5 g / L
Liquid composition (2): 1-10 g / L of chromic anhydride
pH: 3-4
Liquid temperature: 50-60 degreeC
Immersion time: 1 to 20 seconds

Electrolytic chromate treatment liquid composition (1): potassium dichromate 1-10 g / L, zinc 0-5 g / L
Liquid composition (2): 1-10 g / L of chromic anhydride
pH: 3-4
Liquid temperature: 50-60 degreeC
Current density: 0.1-2.6 A / dm ²
Coulomb amount: 0.5-30 As / dm ²

Subsequently, an ultrathin copper layer having a thickness of 35 μm was formed on the intermediate layer on the roll-to-roll-type continuous plating line by electroplating under the following conditions to produce a copper foil with a carrier.
-Ultrathin copper layer Copper concentration: 30-120 g / L
H ₂ SO ₄ concentration: 20 to 120 g / L
Electrolyte temperature: 20-80 ° C
Current density: 10 to 100 A / dm ²

In Examples 1, 3, and 7, the surface of the ultrathin copper layer was subjected to the following roughening treatment, rust prevention treatment, chromate treatment, and silane coupling treatment in this order. Moreover, about Example 2, the roughening process was not performed to the surface of an ultra-thin copper layer, but the following rust prevention processes, the chromate process, and the silane coupling process were performed in this order.
・ Roughening treatment Cu: 10 to 20 g / L
Co: 1-10 g / L
Ni: 1-10g / L
pH: 1-4
Temperature: 40-50 ° C
Current density Dk: 20 to 30 A / dm ²
Time: 1 to 5 seconds Cu adhesion amount: 15 to 40 mg / dm ²
Co adhesion amount: 100 to 3000 μg / dm ²
Ni adhesion amount: 100 to 1000 μg / dm ²
・ Rust prevention treatment Zn: 0-20g / L
Ni: 0 to 5 g / L
pH: 3.5
Temperature: 40 ° C
Current density Dk: 0 to 1.7 A / dm ²
Time: 1 second Zn deposition amount: 5-250 μg / dm ²
Ni adhesion amount: 5 to 300 μg / dm ²
・ Chromate treatment K ₂ Cr ₂ O ₇
(Na ₂ Cr ₂ O ₇ or CrO ₃ ): 2 to 10 g / L
NaOH or KOH: 10-50 g / L
ZnO or ZnSO ₄ 7H ₂ O: 0.05 to 10 g / L
pH: 7-13
Bath temperature: 20-80 ° C
Current density: 0.05 to 5 A / dm ²
Time: 5 to 30 seconds Cr adhesion amount: 10 to 150 μg / dm ²
・ Silane coupling treatment Vinyltriethoxysilane aqueous solution (vinyltriethoxysilane concentration: 0.1 to 1.4 wt%)
pH: 4-5
Time: 5-30 seconds

2. Various evaluations of copper foil with carrier Various evaluations were carried out by the following methods for the copper foil with carrier obtained as described above. The results are shown in Tables 1 and 2.

<Measurement of adhesion amount>
The amount of nickel deposited is measured by ICP emission analysis after dissolving the sample in nitric acid with a concentration of 20% by mass. The amount of chromium deposited is quantitatively analyzed by atomic absorption spectrometry after dissolving the sample in 7% by mass of hydrochloric acid. Measured with

<Measurement by XPS>
After bonding the ultra-thin copper layer side of the copper foil with carrier on the insulating substrate and performing pressure bonding under the conditions of 20 kgf / cm ² and 195 ° C. × 2 hours, the copper foil carrier is peeled off from the ultra-thin copper layer. It was. Subsequently, the exposed ultrathin copper layer surface was subjected to XPS measurement to create a depth profile. XPS operating conditions are shown below.
・ Device: XPS measuring device (ULVAC-PHI, Model 5600MC)
・ Achieving vacuum: 3.8 × 10 ⁻⁷ Pa
X-ray: Monochromatic AlKα or non-monochromatic MgKα, X-ray output 300 W, detection area 800 μmφ, angle between sample and detector 45 °
Ion beam: ion species Ar ⁺ , acceleration voltage 3 kV, sweep area 3 mm × 3 mm, sputtering rate 2.8 nm / min (in terms of SiO ₂ )
Moreover, also about the copper foil with a carrier before the said thermocompression bonding, the copper foil carrier was peeled off from the ultra-thin copper layer, the XPS measurement was performed for the exposed ultra-thin copper layer surface, and the depth profile was created.

<Peel strength>
After bonding the ultra-thin copper layer side of the copper foil with carrier on the insulating substrate and performing pressure bonding under the conditions of 20 kgf / cm ² and 195 ° C. × 2 hours, the copper foil carrier side is peeled off with a load cell. The peel strength was measured. Further, the peel strength of the carrier-attached copper foil before being bonded onto the insulating substrate was also measured.

<Etching evaluation>
After bonding the ultra-thin copper layer side of the copper foil with carrier on the insulating substrate and performing pressure bonding under the conditions of 20 kgf / cm ² and 195 ° C. × 2 hours, the copper foil carrier is peeled off from the ultra-thin copper layer. It was. Subsequently, etching was performed from the surface of the exposed ultrathin copper layer according to the following procedure.
The etched surface of the ultrathin copper layer was degreased with alkali and immersed in sulfuric acid (100 g / L) for 30 seconds to remove the surface contamination and the oxide layer. Next, a liquid resist (manufactured by Tokyo Ohka Kogyo Co., Ltd., OFPR-800LB) was dropped onto the etching surface using a spin coater and dried. The resist thickness after drying was adjusted to 1 μm. Thereafter, 10 circuits were printed by an exposure process, and an etching process for removing unnecessary portions of the copper foil was performed under the following conditions.
・ Ferric chloride aqueous solution (Baume degree: 40)
・ Liquid temperature: 50 ℃
(30 μm pitch circuit formation)
Resist L / S = 25 μm / 5 μm, 21 μm / 9 μm
-Finished circuit bottom (bottom) width: 15 μm
-Etching time: 3 to 15 seconds-Confirmation of etching end point: Etching was carried out at several levels by changing the time, and it was confirmed by an optical microscope that no copper remained between the circuits.
After the etching, the resist was peeled off by being immersed in an aqueous NaOH solution (100 g / L) at 50 ° C. for 1 minute. The circuit shape after the resist peeling was observed with a scanning electron microscope (SEM) (JEOL-5410), and the possibility of circuit formation was determined based on the following criteria.
○: Good etching property Δ: Circuit can be formed, but linearity is poor ×: Circuit cannot be formed

<Discoloration resistance evaluation>
After bonding the ultra-thin copper layer side of the copper foil with carrier on the insulating substrate and performing pressure bonding under the conditions of 20 kgf / cm ² and 195 ° C. × 2 hours, the copper foil carrier is peeled off from the ultra-thin copper layer. After being left in the atmosphere for 24 hours, the color tone of the ultrathin copper layer was measured using a color difference meter with L ^* (brightness), a ^* (red-green axis chromaticity), b ^* (yellow-blue axis) Was measured and evaluated based on (JIS Z 8729) by the color difference ΔE ^* ab shown in Formula (1).
E ^* ab = [(ΔL ^* ) ² + (Δa ^* ) ² + (Δb ^* ) ² ] ^1/2 (1)
The color difference was evaluated as follows based on the ΔE ^* ab value.
0 to less than 0.5: very slightly different 0.5 to less than 1.5: slightly different 1.5 to less than 3.0: appreciably different 3.0 to less than 6.0: significantly different 6 .0 to less than 12.0: very different 12.0 or more: different color system

(Evaluation results)
In each of Examples 1 to 10, the adhesion between the carrier and the ultrathin copper layer is high before the lamination process on the insulating substrate, while the carrier and the ultrathin copper layer are adhered after the lamination process on the insulation substrate. It was easy to peel off at the interface between the carrier and the ultrathin copper layer, the etching property was good, and the corrosion resistance of the surface of the ultrathin copper layer after the carrier was peeled off was good.
In Comparative Examples 11 and 12, the intermediate layer was not formed, and the adhesion amount of nickel and chromium was small, so that the carrier could not be peeled from the ultrathin copper layer even before thermocompression bonding.
In Comparative Example 13, since chromium was not attached, the peeled portion was changed between the intermediate layer and the ultrathin copper layer, and the carrier could not be peeled after bonding to the substrate.
In Comparative Example 14, since the amount of nickel deposited was small and chromium was not deposited, the carrier could not be peeled from the ultrathin copper layer even before thermocompression bonding.
In Comparative Example 15, since the amount of chromium attached was small, the carrier could not be peeled even before thermocompression bonding.
In Comparative Example 16, the concentration of chromium remaining on the surface of the ultrathin copper layer was too high, causing etching failure of the ultrathin copper layer.
In Comparative Examples 17 and 18, since the amount of nickel deposited was too large, the peel strength was too low.
In Comparative Examples 19, 22, and 23, since the nickel concentration on the surface of the ultrathin copper layer was too low, the surface of the ultrathin copper layer was significantly discolored.
In Comparative Examples 20 and 21, since the nickel concentration on the surface of the ultrathin copper layer was low and the chromium concentration was too high, the surface of the ultrathin copper layer was remarkably discolored and further caused etching failure.
In FIG. 1, the XPS depth profile of the depth direction of the ultra-thin copper layer surface before board | substrate bonding of Example 2 is shown. Further, FIG. 2 shows an SEM photograph in which a circuit in which the copper foil carrier was peeled off and the ultrathin copper layer was etched after thermocompression bonding of Example 2 to the substrate was photographed from the upper surface.

Claims (14)

A copper foil with a carrier comprising a copper foil carrier, an intermediate layer laminated on the copper foil carrier, and an ultrathin copper layer laminated on the intermediate layer,
The intermediate layer is configured by laminating a chromium layer or a chromate layer, and a nickel layer or a nickel-phosphorus alloy layer in this order on the copper foil carrier,
The adhesion amount of nickel in the intermediate layer is 1000 to 40000 μg / dm ² , the adhesion amount of nickel-phosphorous alloy is 1000 to 40000 μg / dm ² , and the adhesion amount of chromium is 10 to 1000 μg / dm ² ,
When the copper foil carrier was peeled from the ultrathin copper layer, the atomic concentration (%) of chromium in the depth direction (x: unit nm) obtained from the depth direction analysis from the surface by XPS was expressed as f (x ), The atomic concentration (%) of nickel is g (x), the atomic concentration (%) of copper is h (x), the total atomic concentration (%) of phosphorus is i (x), and the atomic concentration of carbon (%) Is j (x), oxygen atomic concentration (%) is k (x), and other atomic concentration (%) is l (x).
In the section [0, 3.0] of the depth direction analysis from the surface of the ultrathin copper layer, ∫f (x) dx / (∫f (x) dx + ∫g (x) dx + ∫h (x) dx + ∫i (x) dx + ∫j (x) dx + ∫k (x) dx + ∫l (x) dx) is 3% or less, ∫g (x) dx / (∫f (x) dx +付 g (x) dx + ∫h (x) dx + ∫i (x) dx + ∫j (x) dx + ∫k (x) dx + ∫l (x) dx) with copper satisfying 40% or more Foil.   When the copper foil carrier is peeled from the ultrathin copper layer, in the section [0, 3.0] of the depth direction analysis from the ultrathin layer surface, ∫h (x) dx / (∫f (x ) dx + ∫g (x) dx + ∫h (x) dx + ∫i (x) dx + ∫j (x) dx + ∫k (x) dx + ∫l (x) dx) is 1-20% The copper foil with a carrier according to claim 1. When the insulating substrate is thermocompression bonded to the ultrathin copper layer under the conditions of pressure of 20 kgf / cm ² and 195 ° C. × 2 hours in the atmosphere, and the copper foil carrier is peeled from the ultrathin copper layer,
The atomic concentration (%) of chromium in the depth direction (x: nm) obtained from XPS depth direction analysis is f (x), and the atomic concentration (%) of nickel is g (x). , The atomic concentration (%) of copper is h (x), the total atomic concentration (%) of phosphorus is i (x), the atomic concentration (%) of carbon is j (x), and the atomic concentration of oxygen (%) ) Is k (x) and other atomic concentrations (%) are l (x)
In the section [0, 3.0] of the depth direction analysis from the surface of the ultrathin copper layer, ∫f (x) dx / (∫f (x) dx + ∫g (x) dx + ∫h (x) dx + ∫i (x) dx + ∫j (x) dx + ∫k (x) dx + ∫l (x) dx) is 5% or less, ∫g (x) dx / (∫f (x) dx + Claim 1 (g (x) dx + ∫h (x) dx + ∫i (x) dx + ∫j (x) dx + ∫k (x) dx + ∫l (x) dx) satisfies 40% or more Or the copper foil with a carrier of 2 description. When the insulating substrate is thermocompression bonded to the ultrathin copper layer under the conditions of pressure of 20 kgf / cm ² and 195 ° C. × 2 hours in the atmosphere, and the copper foil carrier is peeled from the ultrathin copper layer,
In the interval [0, 3.0] of the depth direction analysis from the surface of the ultrathin layer, ∫h (x) dx / (∫f (x) dx + ∫g (x) dx + ∫h (x) dx The copper foil with a carrier according to any one of claims 1 to 3, wherein + i (x) dx + j (x) dx + k (x) dx + l (x) dx) is 1 to 30%. .   The copper foil with a carrier according to any one of claims 1 to 4, wherein the nickel-phosphorus alloy used in the intermediate layer has a phosphorus concentration of 0 to 20 mass%. Copper foil with carrier according to claim 1 wherein the copper foil career is electrolytic foil or a rolled copper foil.   The copper foil with a carrier in any one of Claims 1-6 which have a roughening process layer in the said ultra-thin copper layer surface.   The copper foil with a carrier according to claim 7, wherein the roughening layer is a layer made of any single member selected from the group consisting of copper, nickel, cobalt, and zinc, or an alloy containing one or more of them.   The copper foil with a carrier of Claim 7 or 8 which has 1 or more types of layers selected from the group which consists of a rust prevention layer, a chromate processing layer, and a silane coupling processing layer on the surface of the said roughening process layer. The copper with a carrier according to any one of claims 1 to 6 , wherein the surface of the ultrathin copper layer has at least one layer selected from the group consisting of a rust prevention layer, a chromate treatment layer, and a silane coupling treatment layer. Foil. A chromium layer or a chromate layer is formed on the copper foil carrier by physical vapor deposition or electroplating, and an intermediate layer is formed by forming a nickel layer or a nickel-phosphorus alloy layer on the chromium layer or the chromate layer. The manufacturing method of the copper foil with a carrier in any one of Claims 1-10 including a process and the process of forming an ultra-thin copper layer by electrolytic plating on the said intermediate | middle layer.   The manufacturing method of the copper foil with a carrier of Claim 11 which further includes the process of forming a roughening process layer on the said ultra-thin copper layer. The laminated body which has the copper foil with a carrier and insulating substrate in any one of Claims 1-10. The manufacturing method of a printed wiring board which manufactures a printed wiring board using the laminated body of Claim 13.