TW201531174A - Composite metal foil, composite metal foil containing carrier, and metal clad laminate and printed wiring board using the same - Google Patents

Abstract

The purpose of the present invention is to provide a composite metal foil for manufacturing printed wiring board. The composite metal foil has three properties of a low thermal expansion better than copper, excellent conductivity property, and good solubility for copper etching solution. To achieve the purpose, a composite metal foil is used, which is characterized in that the composite metal foil has more than one copper layer and more than one nickel alloy layer, wherein the nickel alloy layer is formed by nickel-molybdenum alloy. The total thickness of more than one copper layer is TCu, and the total thickness of more than one nickel-molybdenum alloy layer is TNi-Mo satisfies the relationship of 0.08 ≤ TNi-Mo/TCu ≤ 1.70.

Description

Composite metal foil, composite metal foil with carrier, and metal paste obtained using the same Laminated board and printed wiring board

The present invention relates to a composite metal foil, a composite metal foil having a carrier, and a metal-clad laminate and a printed wiring board obtained by using the same. In particular, it is a composite metal foil formed of one or more copper layers and one or more nickel alloy layers.

In recent years, with the miniaturization of electrical equipment, electronic equipment, and the like, a printed wiring board having a high-density wiring having a small thickness is required. 2. Such a printed wiring board is mainly a copper foil using a metal material and a prepreg using an organic material as a main component. An insulating layer constituent material such as a resin film is produced. Further, since the thermal expansion coefficient of the copper foil and the insulating layer constituent material is largely different, the difference in thermal expansion ratio between the copper foil having a high thermal expansion coefficient and the insulating layer having a low thermal expansion coefficient is caused during the cooling process after the high temperature load. This causes tensile stress or compressive stress to remain inside the printed wiring board, and causes warpage of the printed wiring board. Therefore, in order to reduce the thermal expansion coefficient of the wiring circuit, it has been reviewed to use a metal foil made of a copper alloy, an Fe-Ni alloy or the like as a material constituting the wiring circuit.

Invar is provided on the surface of the copper foil as disclosed in the patent document 1 (Japanese Patent Application Laid-Open No. Hei 03-229892) and the patent document 2 (Japanese Patent Application Laid-Open No. Hei No. 2009-246120). A composite metal foil of an alloy (hereinafter, simply referred to as "Invar foil"). The composition of the Invar alloy constituting the Invar alloy layer is generally known to be 36% by weight of Ni-Fe. The coefficient of thermal expansion of the Invar alloy (20 ° C ~ 90 ° C) is 1.2 × 10 ^-6 K ^-1 ~ 2.0 × 10 ^-6 K ^-1 , because the amount of expansion with temperature changes is small, the dimensional change is small, the resistance The value is 75μΩ. Cm~85μΩ. The range of cm. Therefore, when the Invar alloy foil having the Invar alloy composition disclosed in Patent Document 1 and Patent Document 2 is produced, it is known that an alloy foil having a low thermal expansion property and a controllable electric resistance can be provided. However, the Invar alloy layer has a brittleness due to lack of flexibility, and only slight bending causes fine cracking in the Invar layer, so care must be taken in handling.

In addition, Patent Document 3 (Japanese Patent Application No. 2004-31731) In the publication, a laminated resin wiring board using a metal plate made of a conductive metal material having a thermal expansion coefficient lower than that of copper is used. In order to provide a laminated resin wiring board having excellent dimensional stability or reliability, the patent document 3 has a feature of providing a laminated resin wiring substrate having excellent dimensional stability or reliability. a metal plate having a first main surface and a second main surface and having a conductive metal material having a thermal expansion coefficient lower than that of copper; and at least one of the first main surface and the second main surface A wiring layer made of a conductive metal material having a thermal expansion coefficient lower than that of copper; a resin insulating layer interposed between the metal plate and the wiring layer; and the like.

In paragraphs 0013 and 0014 of the specification of Patent Document 3, as heat A conductive metal material having a lower expansion coefficient than copper is exemplified by a 42 alloy of Fe-Ni alloy (Fe-42% Ni), 50 alloy (Fe-50% Ni), alumina (Fe-36% Ni), super Alumina (Fe-31% Ni-5% Co), iron-nickel-cobalt alloy (Fe-29% Ni-17% Co), and the like. When the conductive metal material of the Fe-Ni alloy disclosed in Patent Document 3 is used, it is understood that it has a lower thermal expansion property than copper. Further, in Patent Document 3, it is suggested that the Fe-Ni-based alloy may be dissolved by a ferric chloride-based copper etching solution used as a copper etching solution.

However, it is possible to use the Invar alloy foil disclosed in the above patent documents. In the case of a printed wiring board of a wiring circuit, in addition to the high resistance and the thickness of the wiring circuit, the amount of heat generated during energization becomes large, and the insulating alloy or the like is formed by the wiring of the wiring circuit. The occurrence of warpage caused by the difference in thermal expansion rate of the layer constituent material or the like causes the possibility of causing deformation of the substrate to become high. In addition, when a wiring circuit made of Invar foil or the like is used, it is used in the formation of a signal transmission circuit even when it is used in a power supply circuit having a large amount of heat generation, and the resistance becomes high when the signal is at the GHz level. The possibility of a delay in signal transmission and a knock on phenomenon is also high.

In addition, the invar alloy foil disclosed in the above patent documents is used. In the case of a metal laminated board, a copper chloride-based copper etching solution other than a ferric chloride-based copper etching solution is used in the formation of the wiring circuit. In the sulfuric acid-hydrogen peroxide-based copper etching solution, the etching rate tends to decrease rapidly, and it tends to be difficult to form a wiring circuit in a short period of time.

As understood from the above, it is desirable to have a printed wiring board in recent years. The metal foil used is required to have "lower thermal expansion performance than copper", "good electrical conductivity", "bronze etching solution, ie, ferric chloride-based copper etching solution, copper chloride-based copper etching solution, sulfuric acid-over A metal foil for the manufacture of printed wiring boards having three characteristics of hydrogen peroxide-based copper etching solution.

Therefore, as a result of active research by the inventors of the present invention, it has been considered that the above problem can be solved by using a composite metal foil having the layer structure shown below.

Composite metal foil: The composite metal foil of the present application is characterized by a composite metal foil composed of one or more copper layers and one or more nickel alloy layers, and the nickel alloy layer is formed of a nickel-molybdenum alloy. When the total thickness of the one or more copper layers is T _Cu and the total thickness of the one or more nickel-molybdenum alloy layers is T _Ni-Mo , it satisfies 0.08 ≦T _Ni-Mo /T _Cu ≦ 1.70 relationship.

Composite metal foil having a carrier: The composite metal foil having a carrier of the present application is characterized in that a carrier is provided on the one-side side of the composite metal foil with a release layer interposed therebetween.

Metal-clad laminate: the characteristics of the metal-clad laminate of this application are It is obtained by using the above composite metal foil or a composite metal foil having a carrier.

Printed wiring board: The printed wiring board of this application is characterized by using the above-mentioned metal laminated board.

The composite metal foil of the present application includes one or more copper layers and a nickel alloy layer formed of one or more nickel-molybdenum alloy layers. In the layered structure of the composite metal foil of the present application, since the nickel-molybdenum alloy layer having a lower thermal expansion property than copper is contained, the composite metal foil as a whole has a lower thermal expansion property than copper. Accordingly, the printed wiring board obtained by using the composite metal foil of the present application can also impart low thermal expansion properties.

Further, the composite metal foil of the present application contains a copper layer having a low electric resistance in its layer constitution. Therefore, when a current is passed through the wiring circuit formed using the composite metal foil, current preferentially flows through the copper layer of the good conductor of electricity, so that a good signal transmission speed can be obtained.

Further, in the case of using the metal-clad laminate of the composite metal foil of the present application, when the composite metal foil is etched to form a wiring circuit, the ferric chloride obtained in the copper etching solution used in the manufacturing process of the printed wiring board is obtained. It is easy to dissolve due to copper etching solution, copper chloride copper etching solution, and sulfuric acid-hydrogen peroxide water copper etching solution.

Further, in the case where the thickness of the composite metal foil of the present application is required to be thin, it can be provided as a composite metal foil having a carrier.

1‧‧‧Composite metal foil

2‧‧‧ copper layer

3‧‧‧ nickel-molybdenum alloy layer

10‧‧‧Composite metal foil with carrier

11‧‧‧ peeling layer

12‧‧‧ Carrier

Fig. 1 is a schematic cross-sectional view for explaining a specific form relating to the layer constitution of the composite metal foil of the present application.

Fig. 2 is a schematic cross-sectional view for explaining a specific form relating to the layer constitution of the composite metal foil having the carrier of the present application.

Hereinafter, the form of the composite metal foil of the present application will be described in order, The form of the composite metal foil of the carrier and the form of the printed wiring board.

A. Form of composite metal foil

The composite metal foil of the present application is a composite metal foil composed of one or more copper layers and one or more nickel alloy layers. Further, the nickel alloy layer is characterized in that the nickel-molybdenum alloy is formed, and the total thickness of the one or more copper layers is T _Cu , and the total thickness of the one or more nickel-molybdenum alloy layers is used. When T _Ni-Mo is set, the relationship of 0.08 ≦T _Ni-Mo /T _Cu ≦ 1.70 is satisfied.

Nickel alloy layer

In the case of the composite metal foil of the present application, the thickness of the wiring circuit, the power supply circuit, or the signal circuit for forming the printed wiring board is considered to specify the overall thickness thereof, so the thickness thereof is not particularly limited. In general, the thickness of the composite metal foil of the present application is used in the range of 1 μm to 35 μm.

Therefore, the nickel alloy layer of the composite metal foil of the present application uses a nickel-molybdenum alloy. Nickel has excellent oxidation resistance in air, and has a low electrical resistance (69.3nΩ.m: 20°C), which is smaller than the thermal expansion coefficient of copper (16.5μm.m ^-1 .k ^-1 :25°C) (13.4). ^{μm.m -1 .k -1: 25 ℃)} , and is also excellent in flexibility of the metal component. On the other hand, molybdenum has a lower electrical resistance (53.4 nΩ.m: 20 ° C) than nickel, and has a very low thermal expansion rate (4.8 μm.m ^-1 .k ^-1 : 25 ° C) as a metal material, and is hard and brittle. The metal composition. Because of the nickel and molybdenum having a thermal expansion coefficient than copper: a small coefficient of thermal expansion ^{(16.5μm.m -1 .k -1 25 ℃)} , it can be readily understood by those of nickel alloy - molybdenum alloy, the thermal expansion coefficient of copper is also The thermal expansion rate is below. Further, by using molybdenum which is difficult to use alone in the state of a nickel-molybdenum alloy, it is possible to obtain a thermal expansion ratio smaller than that of nickel alone in a manner of moderate flexibility. Further, in the case where nickel alone is difficult to dissolve by the copper etching solution, in the case of the nickel-molybdenum alloy, it can be dissolved by the copper etching solution, and an etching rate which is practically problem-free can be obtained.

As for the nickel-molybdenum alloy, it is preferred to have a molybdenum content of 10 atom% to 50 atom%, and the balance is nickel and an unavoidable impurity. In the composition of a nickel-molybdenum alloy, When the molybdenum content is less than 10 atom%, the nickel content is large, and the thermal expansion rate and the nickel alone are hardly changed. Further, the etching rate of the nickel-molybdenum alloy by the copper etching solution is lowered, and it is difficult to perform rapid etching processing. On the other hand, when the molybdenum content exceeds 50 atomic%, the thermal expansion coefficient is lowered, but the flexibility of the nickel-molybdenum alloy is lowered, and fine cracking is likely to occur when subjected to bending stress. The nickel-molybdenum alloy in the present application does not impair "lower thermal expansion performance than copper", "good electrical conductivity", "ferric chloride-based copper etching solution by copper etching solution, copper chloride copper" The etchant and the sulfuric acid-hydrogen peroxide water-based copper etching solution may contain other components such as Co, Fe, W, Si, and Mn.

2. The relationship between the thickness of the copper layer and the nickel alloy layer

The relationship between the thickness of the "copper layer" and the "nickel-molybdenum alloy layer" constituting the composite metal foil is very important, unlike the overall thickness of the composite metal foil of the above-mentioned application. In the present invention, when the total thickness of the copper layer of one or more layers is T _Cu and the total thickness of the nickel-molybdenum alloy layer of one or more layers is T _Ni-Mo , it is preferable to satisfy 0.08 ≦T _{Ni. -Mo} /T _Cu ≦1.70 relationship. Herein, when T _Ni-Mo /T _{Cu is} less than 0.08, even if there is a nickel-molybdenum alloy layer having a lower thermal expansion property than copper, the composite metal foil as a whole cannot obtain a better low thermal expansion property than copper. On the other hand, when T _Ni-Mo /T _Cu exceeds 1.70, the nickel-molybdenum alloy layer becomes thick, and it is not possible to form a desired circuit shape by etching, and it is disadvantageous in that a wiring circuit having a good etching factor cannot be obtained. In the case where the composite metal foil of the present application has "a copper layer of two or more layers", the total thickness of the two or more copper layers is "T _Cu " and the "two or more nickel-molybdenum alloy layers" are provided. The total thickness of the nickel-molybdenum alloy layers of two or more layers is set to "T _Ni-Mo ".

3. The specific form of composite metal foil

The specific form of the composite metal foil of the present application will be described using FIG. When the composite metal foil described below satisfies the above conditions, it will have "lower thermal expansion performance than copper", "good electrical conductivity", "ferric chloride-based copper etching solution by copper etching solution, and copper chloride. Copper etchant, sulfuric acid-hydrogen peroxide water copper etchant due to the solubility can. However, the form of the composite metal foil of the present application is not construed as being limited to the form described below, and a layer constitution comprising three or more nickel-molybdenum alloy layers may be suitably employed.

First aspect of the composite metal foil: the first aspect of the composite metal foil is as follows As understood from the schematic cross-sectional view shown in Fig. 1(A), the composite metal foil 1 having a layer of "copper layer 2 / nickel-molybdenum alloy layer 3" is provided. The composite metal foil 1 having such a layer can be bonded to the side of the copper layer 2 or the side of the nickel-molybdenum alloy layer 3 to the insulating layer constituent material to produce a metal laminated board for producing a printed wiring board.

In the former case, the side of the copper layer 2 of the composite metal foil 1 is attached to A metal laminated board is produced on the insulating layer constituent material. Further, when the etching process for forming a wiring circuit is performed using the metal-clad laminate, since the nickel-molybdenum alloy layer 3 having an etching rate slower than copper is located on the surface, the top side of the formed wiring circuit is not easily over-etched, and it is easy. A wiring circuit with a good etching factor is formed.

On the other hand, in the latter case, the nickel-molybdenum composite metal foil 1 is combined The side of the gold layer 3 is bonded to the insulating layer constituent material to produce a metal laminated board. Further, when the etching process for forming a wiring circuit is performed using the metal-clad laminate, since the nickel-molybdenum alloy layer 3 having a slower etching speed than copper is located on the side of the insulating layer at the end of the etching process, it is effective even if a wiring circuit is formed. The undercut phenomenon caused by the penetration of the etching solution into the interface between the wiring circuit and the insulating layer is prevented.

Second aspect of the composite metal foil: the second form of the composite metal foil is as follows As understood from the schematic cross-sectional view shown in Fig. 1(B), the composite metal foil 1 having a layer of "nickel-molybdenum alloy layer 3/copper layer 2/nickel-molybdenum alloy layer 3" is provided. In the case of the composite metal foil 1 composed of the layer, the surface of the nickel-molybdenum alloy layer 3 is bonded to the insulating layer constituent material to produce a metal laminated board for producing a printed wiring board. Therefore, when the etching process for forming a wiring circuit is performed using the metal-clad laminate, the nickel-molybdenum alloy layer 3 having an etching rate slower than copper exists on the surface of the etching start and the insulating layer side where the etching process is completed. Therefore, the nickel-molybdenum alloy layer 3 located on the surface is not easily over-etched on the top side of the formed distribution circuit. therefore, The nickel-molybdenum alloy layer 3 located on the insulating layer side at the end of the etching process can effectively prevent the undercut phenomenon caused by the penetration of the etching liquid into the interface between the wiring circuit and the insulating layer even if the wiring circuit is formed in the same manner as described above. As a result, it is easy to form a wiring circuit having a good etching factor.

The third aspect of the composite metal foil: the third form of the composite metal foil can be as As understood from the schematic cross-sectional view shown in Fig. 1(C), the composite metal foil 1 having a layer of "copper layer 2 / nickel-molybdenum alloy layer 3 / copper layer 2" is provided. The composite metal foil 1 of this layer is formed by bonding the surface of one of the copper layers 2 to the insulating layer constituent material, and manufacturing a metal-clad laminate for producing a printed wiring board. Therefore, when the etching process for forming a wiring circuit is performed using the metal-clad laminate, the wiring circuit obtained also has a layer structure of "copper layer 2 / nickel-molybdenum alloy layer 3 / copper layer 2", and electrical properties are obtained. The copper layer 2 of a good conductor exists on the surface of the wiring circuit. Accordingly, the wiring circuit having the layer configuration is suitable for the case where the signal current flows through the surface layer of the wiring circuit due to the skin effect generated when the high frequency signal flows.

Surface treatment of composite metal foil: the composite metal foil described above is Improve with prepreg. The resin film or the like is a sealing property of the insulating layer constituent material, and the surface of the copper layer 2 or the nickel-molybdenum alloy layer 3 bonded to the insulating layer constituent material can be roughened. There is no particular limitation on the roughening treatment method at this time. However, when the surface of the copper layer 2 is subjected to a roughening treatment, it is preferable to apply a conventional roughening treatment such as a roughening treatment for depositing and adhering fine particles to the surface of the copper layer 2. For example, fine copper particles may be deposited on the surface of the copper layer 2 of the composite metal foil 1 by using copper plating conditions.

Moreover, the copper layer 2 or the roughened surface exposed by the above roughening treatment is exposed When it is on the surface, it is preferred to apply a rust-proof treatment to at least the surface of the copper layer which is rapidly oxidized or the roughened surface to ensure long-term storage performance. The rustproof treatment at this time is not particularly limited. For example, organic rust prevention such as benzotriazole or imidazole or inorganic rust prevention such as zinc, chromate or zinc alloy may be used. Further, in the case of the composite metal foil of the present application, depending on the use, it is also preferred to apply a decane coupling agent to the copper layer 2 or the roughened surface to improve the adhesion to the insulating layer constituent material.

Method for producing composite metal foil: manufacturing composite metal foil of the present application In the case of the copper foil 2, the copper foil constituting the copper layer 2 is preferably prepared, and the nickel-molybdenum alloy layer 3 is formed by electrolytic precipitation on the surface of the copper foil. The nickel-molybdenum alloy plating solution and plating conditions used at this time are preferably the following conditions. The reason for this is that the molybdenum content of the nickel-molybdenum alloy layer 3 can be increased, and the thickness control of the nickel-molybdenum alloy layer 3 can be easily performed.

(Nickel-molybdenum alloy plating solution and plating conditions)

Nickel sulfate. 6 hydrate: 30g / L ~ 50g / L

2 sodium molybdate. 2 hydrate: 5g / L ~ 60g / L

Misagent: 10g/L~150g/L

Solution pH: 8~12

Current density: 5A/dm ² ~ 30A/dm ²

As the distorting agent referred to herein, a compound having a carboxyl group and/or an amine group is preferably used. Specifically, it is exemplified by gluconic acid, sodium potassium tartrate, citric acid, acetic acid, malic acid, glycine acid, aspartic acid, ethylenediaminetetraacetic acid, and the like.

Further, when a relatively thin copper layer 2 having a thickness of 5 μm or less is required, it is difficult to prepare a copper foil having such a thickness and depositing a nickel-molybdenum alloy layer 3 on the surface thereof by an electrolytic method. In this case, a form and a production method of a composite metal foil having a carrier described later are preferably used.

4. The specific form of composite metal foil with carrier

A specific form of the composite metal foil with a carrier according to the present application will be described with reference to Fig. 2 . The composite metal foil with a carrier is characterized in that the release layer 11 is provided with a carrier 12 on one side of the composite metal foil 1 . The composite metal foil with the carrier is thinner for the above-mentioned composite metal foil, and is difficult to operate, and the pollution prevention of the surface of the composite metal foil is considered. It is a useful form when the foreign matter is adhered or the like. The composite metal foil constituting the composite metal foil having the carrier described below can have a low thermal expansion performance called "better than copper", "good electrical conductivity", and "chlorinated copper etching liquid" as long as the above conditions are satisfied. Iron-based copper etching solution, copper chloride-based copper etching solution, sulfuric acid-hydrogen peroxide water-based copper etching The performance of the solubility due to engraving. However, the form of the composite metal foil of the present application is not construed as being limited to the form described below, and a layer constitution comprising three or more layers of a nickel-molybdenum alloy layer can be suitably employed.

First aspect of a composite metal foil having a carrier: a composite having the carrier The first aspect of the metal foil is understood to be a schematic cross-sectional view shown in Fig. 2(a), and is provided with a layer of "copper layer 2 / nickel-molybdenum alloy layer 3 / release layer 11 / carrier 12". Composite metal foil 10. In the composite metal foil 10 having a carrier, the side of the copper layer 2 is bonded to the insulating layer constituent material, and then the carrier 12 is peeled off from the peeling layer 11 to produce a metal clad laminate for producing a printed wiring board. The surface of the metal clad laminate is provided with a nickel-molybdenum alloy layer 3 having an etching rate slower than that of copper. In the same manner as in the case of "the first aspect of the composite metal foil", the case where the side of the copper layer 2 of the composite metal foil 1 is bonded to the insulating layer constituent material to form a metal laminated board is used, and the metal laminated board is used. When the etching process for forming the wiring circuit is performed, since the nickel-molybdenum alloy layer 3 having an etching rate slower than copper is located on the surface, the top side of the formed wiring circuit is less likely to be excessively etched, and a wiring circuit having a good etching factor can be easily formed.

Second aspect of composite metal foil with carrier: composite with carrier The second aspect of the metal foil is understood to be a schematic cross-sectional view shown in FIG. 2(b), and is provided with a layer of a layer of "nickel-molybdenum alloy layer 3/copper layer 2/release layer 11/carrier 12". Composite metal foil 10. In the composite metal foil 10 having a carrier, the side of the nickel-molybdenum alloy layer 3 is bonded to the insulating layer constituent material, and then the carrier 12 is peeled off from the peeling layer 11 to produce a metal for manufacturing a printed wiring board. Laminated board. The surface of the metal-clad laminate is provided with a copper layer 3 having a fast etching rate, and the nickel-molybdenum alloy layer 3 having a slower etching speed than copper is located on the side of the insulating layer at the end of the etching process. According to the above, "the first aspect of the composite metal foil" is the same as the case where the side of the nickel-molybdenum alloy layer 3 of the composite metal foil 1 is bonded to the insulating layer constituent material to form a metal laminated board. The wiring circuit can effectively prevent the undercut phenomenon caused by the etching liquid penetrating into the interface between the wiring circuit and the insulating layer.

The third aspect of the composite metal foil having a carrier: the composite having the carrier The third aspect of the metal foil is understood to be "a nickel-molybdenum alloy layer 3/copper layer 2/nickel-molybdenum alloy layer 3/release layer 11/carrier 12" as understood from the schematic cross-sectional view shown in Fig. 2(c). The composite metal foil 10 having a carrier formed of layers. The composite metal foil 10 having a carrier is bonded to the insulating layer material on the side of the nickel-molybdenum alloy layer 3 on the outermost surface, and then the carrier 12 is peeled off from the peeling layer 11 to produce a printed wiring. Plate metal laminated board. The layer structure of the metal-clad laminate is the same as the layer structure of the metal-clad laminate obtained in the "second aspect of the composite metal foil" described above, and the same effect as the "second aspect of the composite metal foil" can be obtained.

Fourth aspect of composite metal foil with carrier: composite with carrier As for the fourth aspect of the metal foil, as can be understood from the schematic cross-sectional view shown in FIG. 2(d), the layer structure of "copper layer 2 / nickel-molybdenum alloy layer 3 / copper layer 2 / peeling layer 11 / carrier 12" is provided. The composite metal foil 10 having a carrier. The composite metal foil 10 having a carrier is bonded to the insulating layer constituent material on the side of the copper layer 2 on the outermost surface, and then the carrier 12 is peeled off from the peeling layer 11 to produce a sticker for manufacturing a printed wiring board. Metal laminate. In this case, the layer structure of the metal-clad laminate is the same as the layer structure of the metal-clad laminate obtained in the above-described "third aspect of the composite metal foil", and the same effect as the "third aspect of the composite metal foil" can be obtained.

Carrier: used in the composite metal foil 10 having the carrier of the present application The carrier 12 is not particularly limited as long as it has conductivity. For example, an aluminum foil, a copper foil, a resin film coated with a metal surface, or the like can be used. Further, there is no limitation on the thickness of the carrier 12.

Peeling layer: peeling of composite metal foil 10 with carrier of the present application The layer 11 has an "organic release layer" formed using an organic component and an "inorganic release layer" formed using an inorganic component.

When the "organic release layer" is used as the release layer 11, it is preferred to use At least one or more of the compounds selected from the group consisting of a nitrogen-containing organic compound, a sulfur-containing organic compound, and a carboxylic acid are used as the organic component. Included in the nitrogen-containing organic compounds referred to herein A nitrogen-containing organic compound having a substituent. Specifically, as the nitrogen-containing organic compound, 1,2,3-benzotriazole, carboxybenzotriazole, N', N'-bis(benzotriazole) having a substituted triazole compound is preferably used. Methyl)urea, 1H-1,2,4-triazole and 3-amino-1H-1,2,4-triazole and the like. Further, as the sulfur-containing organic compound, mercaptobenzotriazole, thiocyanuric acid, 2-benzimidazolethiol or the like is preferably used. Further, as the carboxylic acid, a monocarboxylic acid is preferably used, and among them, oleic acid, linoleic acid and linoleic acid are preferably used. Since these organic components are excellent in high-temperature heat resistance, it is easy to form a peeling layer having a thickness of 5 nm to 60 nm on the surface of the carrier.

Moreover, when using an "inorganic release layer", it is possible to use Ni, Mo, At least one or more selected from the group consisting of Co, Cr, Fe, Ti, W, P or an alloy or a compound having such a main component as an inorganic component. In the case of such an inorganic release layer, it can be formed by a conventional method such as an electroplating method, an electroless method, or a physical vapor deposition method.

Manufacturing method of composite metal foil with carrier: composite with carrier The metal foil is manufactured by the following method. The surface of the carrier 12 is cleaned by pickling treatment or the like, a release layer 11 is formed on the surface of the purified carrier 12, and the surface of the release layer 11 is formed according to a desired layer, and copper and nickel-molybdenum are deposited by electrolysis. The alloy forms a copper layer 2 constituting the composite metal foil 1 and a nickel-molybdenum alloy layer 3. Next, the surface of the composite metal foil 1 may be subjected to a roughening treatment, a rustproof treatment, a decane coupling agent treatment, or the like as needed, and may be produced by a drying treatment.

B. Metal laminated board

The metal-clad laminate of the present application is formed by laminating the composite metal foil of the present application or the composite metal foil and the insulating layer material having the carrier, and comprises a hard metal-clad laminate and a flexible metal-clad laminate. By. That is, there is no particular limitation on the type of the insulating layer constituent material referred to herein. When the composite metal foil of the present application or the composite metal foil having the carrier foil is used, even if the insulating layer constituent material is bonded, since the "low thermal expansion property better than copper" is provided, the metal laminated board can be reduced. Warping. distortion.

C. Form of printed wiring board

The printed wiring board of the present application is characterized by using the above composite metal foil or a composite metal foil provided with a carrier. Here, the printed wiring board is a concept including all of the printed wiring boards such as a rigid printed wiring board and a flexible printed wiring board. Further, the printed wiring board of the present application includes all printed wiring boards such as a single-sided printed wiring board, a double-sided printed wiring board, and a multilayer printed wiring board. Further, the printed wiring board of the present application forms a printed circuit using the composite metal foil of the present application or a composite metal foil having a carrier, and has "a low thermal expansion performance better than copper" and "good electrical conductivity" and "good conductivity". The copper chloride etching solution is a ferric chloride-based copper etching solution, a copper chloride-based copper etching solution, and a sulfuric acid-hydrogen peroxide aqueous copper etching solution.

[Example 1]

In the first embodiment, an untreated copper foil (electrolyzed copper foil having a thickness (T _Cu ) of 12 μm) was used, and nickel-molybdenum alloy plating having the thickness (the total thickness of both surfaces) shown in Table 1 was performed on both surfaces thereof, and was obtained. The composite metal foil 1 of the four types of nickel-molybdenum alloy layer 3/copper layer 2/nickel-molybdenum alloy layer 3 shown in Fig. 1(B) and having the same thickness of the nickel-molybdenum alloy layer on both sides (Implementation of sample 1 to sample 4). The nickel-molybdenum alloy plating solution and plating conditions at this time are as follows.

(Nickel-molybdenum alloy plating solution and plating conditions)

Nickel sulfate. 6 hydrate: 40g / L

2 sodium molybdate. 2 hydrate: 25g / L

Sodium citrate: 80g/L

Solution pH: 9

Current density: 16A/dm ²

Anode electrode: insoluble anode

Next, the thermal expansion coefficient and the electric resistance value of the composite metal foil 1 in the sample 1 to the sample 4 were measured. The coefficient of thermal expansion was measured twice in a nitrogen atmosphere at a temperature rising rate of 5 ° C / min under a tensile load method, and the average of the thermal expansion coefficients from 20 ° C to 320 ° C in the second measurement was calculated. value. The measurement of the resistance value is It is carried out by a resistance value measuring device which is performed by a four-terminal method. Further, the contents of nickel and molybdenum contained in the nickel-molybdenum alloy layer were measured using an energy dispersive characteristic X-ray analyzer. The measurement results are shown in Table 1.

[Comparative Example 1]

Comparative Example 1 described below is for comparison with Example 1 relating to the above composite metal foil. In Comparative Example 1, an untreated copper foil (electrolyzed copper foil having a thickness (T _Cu ) of 12 μm) similar to that of the sample 1 was used, and "nickel-molybdenum alloy plating" of the sample 1 was replaced with "nickel plating". And nickel plating was performed on both sides of the copper foil in the thickness shown in Table 1 (the total thickness of both surfaces) to obtain a layer having a "nickel layer/copper layer/nickel layer" and a thickness of the nickel plating layer on both sides. Equal composite metal foil (Comparative Sample 1). Next, the thermal expansion coefficient and the electric resistance value of the composite metal foil 1 of the comparative sample 1 were measured in the same manner as in the first embodiment. The measurement results are shown in Table 1. Moreover, the nickel plating solution and plating conditions at this time are as follows.

(nickel plating solution and plating conditions)

Nickel sulfate. 6 hydrate: 40g / L

Sodium citrate: 80g/L

Solution pH: 9

Current density: 16A/dm ²

Anode electrode: insoluble anode

[Comparative Example 2]

Comparative Example 2 is for comparison with Example 1 relating to the above-described composite metal foil with a carrier. In Comparative Example 2, an untreated copper foil (electrolyzed copper foil having a thickness (T _Cu ) of 12 μm) similar to that of the sample 1 was used, and "nickel-molybdenum alloy plating" of the sample 4 was replaced with "molybdenum plating". And molybdenum plating having the thickness (the total thickness of both surfaces) shown in Table 1 on both sides of the copper foil, and obtaining a layer having a "molybdenum layer/copper layer/molybdenum layer" and a thickness of the molybdenum plating layer on both sides Equal composite metal foil (Comparative Sample 2). However, the state in which the molybdenum layer becomes embrittled cannot be processed into a metal-clad laminate, and the thermal expansion coefficient of the composite metal foil cannot be determined. Determination of resistance value. Moreover, the molybdenum plating solution and plating conditions at this time are as follows.

(molybdenum plating solution and plating conditions)

2 sodium molybdate. 2 hydrate: 25g / L

Sodium citrate: 80g/L

Solution pH: 9

Current density: 16A/dm ²

Anode electrode: insoluble anode

<Comparison of Example 1 and Comparative Example>

In Comparative Example 2 (Comparative Sample 2), since the molybdenum layer was in an embrittled state as described above, it could not be processed into a metal-clad laminate, and therefore it could not be compared with the examples. Therefore, the comparison between Example 1 (Example 1 to Sample 4) and Comparative Example 1 (Comparative Sample 1) will be described below.

As can be seen from Table 1, all of the sample 1 to the sample 4 were subjected to the relationship of 0.08 ≦T _Ni-Mo /T _Cu ≦ 1.70. Further, the molybdenum content of the nickel-molybdenum alloy constituting the nickel-molybdenum alloy layer also falls within an appropriate range. Here, it can be understood that the thicker the thickness of the nickel-molybdenum alloy layer, the higher the resistance value and the smaller the coefficient of thermal expansion. Further, the resistance value of the sample 1 to the sample 4 was 5.44 × 10 ^-6 Ω. In the range of cm or less, it is considered that the composite metal foil for forming a wiring circuit of a printed wiring board is practically unimpeded. On the other hand, in the case where the alloy layer does not contain molybdenum and only the comparative sample 1 of nickel is used, the resistance value is high and is 6.20 × 10 ^-6 Ω. Cm. Further, when the thermal expansion coefficient of the comparative sample 1 having the nickel layer having the same thickness as the nickel-molybdenum alloy layer of the sample 1 was compared, the sample 1 was set to 11.0 ppm/°C, whereas the comparative sample 1 was significantly higher. It is 15.5 ppm/°C. Further, for the sake of caution, the comparative sample 1 described in the column of T _Ni-Mo /T _Cu values in Table 1 is the value of T _Ni /T _Cu , and the comparative sample 2 is the value of T _Mo /T _Cu .

Further, each of the sample 1 to the sample 4 and the sample 1 to be tested is attached. The metal laminate was fabricated on the prepreg and subjected to an etching test. In the etching liquid, a ferric chloride-based copper etching solution, a copper chloride-based copper etching solution, and a sulfuric acid-hydrogen peroxide-based copper etching solution were used. As a result, the sample 1 to the sample 4 to be subjected to the metal-clad laminate can be easily dissolved and removed. However, when the sample 1 is used, it is difficult to dissolve the nickel, and it takes a long time to form the circuit.

[Embodiment 2]

In the second embodiment, a composite metal having a carrier foil having a layer of "copper layer 2 / nickel-molybdenum alloy layer 3 / copper layer 2 / release layer 11 / carrier 12" shown in Fig. 2 (d) is produced (samples are carried out) 5) The sample 7) is provided with a carrier foil comprising a layer of "nickel-molybdenum alloy layer 3/copper layer 2/nickel-molybdenum alloy layer 3/release layer 11/carrier 12" shown in Fig. 2(c). Composite metal (sample 8 was carried out). The following describes the manufacturing method of the sample 5 to the sample 8 to be carried out.

<Formation of Sample 5 to Formation of Carrier Foil and Peeling Layer Used in Sample 8>

An electrolytic copper foil having a thickness of 18 μm was used as a carrier foil, and the carrier foil was immersed in a sulfuric acid aqueous solution containing 150 g/L of sulfuric acid, 10 g/L of copper, a concentration of carboxybenzotriazole of 800 mg/L, and a liquid temperature of 30 ° C containing an organic agent. After 30 seconds, the contaminating component attached to the carrier foil was removed, and the carboxybenzotriazole was adsorbed on the surface of the carrier foil to form a release layer on the surface of the carrier foil.

<Formation of composite metal foil>

[Formation of Sample 5 to Formation of Composite Metal Foil for Carrying Sample 7]

First, a composite metal foil having a composite foil of a carrier foil is provided with a sample having a layer structure of "copper layer 2 / nickel-molybdenum alloy layer 3 / copper layer 2". The sample 5 to the sample 7 was subjected to the conditions shown in Table 2, and the carrier foil having the release layer was subjected to cathode polarization in the plating solution, and a copper layer having a thickness of 1.5 μm was formed on the release layer, and the copper layer was formed on the release layer. The surface was subjected to nickel-molybdenum alloy plating to form a nickel-molybdenum alloy layer having a thickness of 4 μm, and a copper layer having a thickness of 1.5 μm was formed on the surface of the nickel-molybdenum alloy layer to form a composite metal foil having a thickness of 7 μm.

[Formation of composite metal foil of sample 8]

Next, a composite metal foil having a composite foil of a carrier foil is provided with a sample 8 having a layer structure of "nickel-molybdenum alloy layer 3/copper layer 2/nickel-molybdenum alloy layer 3". The sample 8 was subjected to cathode polarization in a plating solution under the conditions shown in Table 2, and nickel-molybdenum alloy plating was performed to form a nickel-molybdenum alloy layer having a thickness of 1.5 μm. A copper layer having a thickness of 4 μm was formed on the surface of the nickel-molybdenum alloy layer, and a nickel-molybdenum alloy layer having a thickness of 1.5 μm was formed on the surface of the copper layer to form a composite metal foil having a thickness of 7 μm.

<Surface Treatment of Composite Metal Foil>

The surface of the composite metal foil of the composite foil with a carrier foil obtained above is not subjected to a roughening treatment to form a zinc-nickel alloy antirust layer, and is subjected to an electrolytic chromate treatment or an amine-based decane coupling agent to obtain The surface-treated composite metal foil with a carrier foil (sample 5 to sample 8 was carried out).

<Discussion on Embodiment 2>

The discussion about Example 2 (Example 5 to Sample 8) will be described below. Table 3 shows the measurement results of the thermal expansion coefficient and electric resistance of the sample 5 to the sample 8 to be carried out.

As can be seen from Table 3, all of the sample 5 to the sample 8 were subjected to the relationship of 0.08 ≦T _Ni-Mo /T _Cu ≦ 1.70. Further, the molybdenum content of the nickel-molybdenum alloy constituting the nickel-molybdenum alloy layer also falls within an appropriate range. Here, it can be understood that the higher the nickel content contained in the nickel-molybdenum alloy layer, the higher the electric resistance value and the higher the thermal expansion coefficient. However, the resistance value of the sample 5 to the implementation sample 8 is 5.1×10 ^-6 Ω. In the range of cm or less, it is considered that the composite metal foil for forming a wiring circuit of a printed wiring board is practically unimpeded.

Further, each of the sample 5 to the sample 8 is applied to the prepreg. On the top, a metal laminated board was fabricated and an etching test was performed. In the case of the etching liquid at this time, the same composite material as in the first embodiment was used, and the composite metal layer of the sample 5 to the sample 8 was easily dissolved and removed.

[Industrial availability]

The composite metal foil of the present application comprises a nickel-molybdenum alloy layer having a lower thermal expansion property than copper. Therefore, the printed wiring board itself can be imparted with a good low thermal expansion property by using the composite metal foil of the present application to produce a metal-clad laminate. Further, when a wiring circuit is formed using the composite metal foil of the present application, the layer structure includes a copper layer having a low electrical resistance. As a result, since the current preferentially flows to the copper layer of the electrically good conductor, it has good electrical conductivity. Further, when the metal-clad laminate obtained by using the composite metal foil of the present application is subjected to etching processing to form a wiring circuit, since the composite metal foil is easily dissolved, no new equipment investment is required, and both of them can be effectively utilized. There is a printed wiring board manufacturing device.

1‧‧‧Composite metal foil

2‧‧‧ copper layer

3‧‧‧ nickel-molybdenum alloy layer

Claims (7)

A composite metal foil characterized by a composite metal foil composed of one or more copper layers and one or more nickel alloy layers, and the nickel alloy layer is formed of a nickel-molybdenum alloy, and the first layer is formed When the total thickness of the above copper layers is T _Cu and the total thickness of the one or more nickel-molybdenum alloy layers is T _Ni-Mo , the relationship of 0.08 ≦T _Ni-Mo /T _Cu ≦ 1.70 is satisfied. The composite metal foil according to claim 1 which is provided with a layer of a copper layer/nickel-molybdenum alloy layer/copper layer. The composite metal foil according to claim 1 which is provided with a layer of a nickel-molybdenum alloy layer/copper layer/nickel-molybdenum alloy layer. The composite metal foil according to claim 1, wherein the nickel-molybdenum alloy layer has a molybdenum content of 10 atom% to 50 atom%, and the balance is nickel and unavoidable impurities. A composite metal foil having a carrier characterized by being provided with a carrier on the one-side side of the composite metal foil of claim 1 and having a release layer. A metal-clad laminate characterized by using a composite metal foil as claimed in claim 1 or a composite metal foil having a carrier according to claim 5. A printed wiring board characterized by using a metal clad laminate as claimed in claim 6.