TW201822606A - Composite metal foil, copper clad laminate using the composite metal foil and method for manufacturing the copper clad laminate using a composite metal foil to produce a copper clad laminate laminated with an ultra-thin copper layer that is very thin, dense and uneasy to produce pores - Google Patents

Abstract

The present invention aims to provide a composite metal foil which can be used to manufacture, through a simple method, a copper clad laminate laminated with an ultra-thin copper layer that is very thin, dense and uneasy to produce pores. When the ultra-thin copper layer is used as a seed layer to form a circuit through an additive process, the seed layer can be removed by etching in a short time, so that the circuit can be prevented from being etched. In addition, when the copper clad laminate is used to manufacture a multi-layer substrate, the increase in entire thickness of the multi-layer substrate can be suppressed, so as to form a high-density multi-layer substrate. The composite metal foil of the present invention is sequentially laminated with a metal foil carrier, a first Ni or Ni alloy layer on at least one surface of the metal foil carrier, a stripping layer on at least one surface of the first Ni or Ni alloy layer, a second Ni layer and an ultra-thin copper layer. The primary particle diameter of a copper particle of the ultra-thin copper layer is 10 to 200 nm, and its attachment amount is 300 to 6000 mg/m2. The thickness of the second Ni layer is 0.3 to 5 mm.

Description

Composite metal foil, copper-clad laminated board using the same, and method for manufacturing the copper-clad laminated board

FIELD OF THE INVENTION The present invention relates to a composite metal foil, a copper-clad laminate using the same, and a method for manufacturing the copper-clad laminate. Specifically, the present invention relates to a composite metal foil, a copper-clad laminate using the composite metal foil, and a method for manufacturing the copper-clad laminate, wherein the composite metal foil can be used to produce extremely thin laminates by a simple method. A copper-clad laminate with a copper layer, and the extremely thin copper layer is extremely thin and dense, so pinholes are not easily generated. Therefore, by using the extremely thin copper layer as a seed layer for the addition method, the The seed layer is etched away to suppress the etching of the circuit itself to form a fine-patterned circuit. Furthermore, by using a copper-clad laminate made of the composite metal foil to manufacture a multilayer substrate, the vias and non-vias are made for interlayer connection. Electroless plating and / or electroplating, because the copper layer itself is extremely thin, can also suppress the overall thickness of the multilayer substrate, and therefore, a high-density multilayer substrate can be manufactured.

BACKGROUND OF THE INVENTION In an electronic device that requires miniaturization or an increase in processing speed, a package substrate is mounted, and the package substrate is printed using a printed circuit board or a multilayer structure in which a circuit having a fine pattern (hereinafter referred to as a "fine pattern") is formed. The circuit board is densely packed with semiconductor elements.

In addition, for a packaged component, a multilayer substrate is used for rewiring. For this multilayer substrate, a circuit with a fine pattern is also required as the component is miniaturized.

In the past, the line width and line pitch (that is, the interval) of a circuit called a fine pattern (hereinafter referred to as "L / S") was L / S = 30mm / 30mm. In recent years, L / S = 15mm / 15mm, L / S = 10mm / 10mm and other ultra-fine pattern circuit requirements.

Generally, as a copper-clad laminated board for forming a fine pattern circuit, a copper-clad laminated board in which an ultra-thin copper foil is laminated to an insulating resin substrate (hereinafter referred to as a "substrate") is used. In the case of a copper foil having a thickness of less than 9 mm, problems such as wrinkles or cracks are likely to occur when bonding a copper-clad laminate.

Therefore, a method is currently being developed for roughening the ultra-thin copper foil surface of a composite metal foil obtained by laminating an ultra-thin copper foil on a support (hereinafter referred to as a "carrier"), and then bonding the surface. The carrier was peeled from the substrate, and a copper-clad laminated board on which an extremely thin copper foil was laminated was produced.

As a method for laminating a copper-clad laminate with an ultra-thin copper foil layer, in addition to a method using an ultra-thin copper foil with a carrier, a method has been developed in which a copper foil having a thickness of 12 mm or less is bonded and a half-etching technique is used The copper foil is thinned to form an extremely thin copper foil layer.

As a method for forming a circuit with a fine pattern using a copper-clad laminate having an extremely thin copper foil layer, a subtractive method and an additive method are known.

However, in the subtractive method, the thickness of the conductor (a very thin copper foil layer) is too thin to be directly used as a circuit. In addition, there is a problem that, when a plating process is performed for thickening, a space portion becomes narrow due to copper plating grown from a lead portion, and as a result, it is difficult to form a fine-patterned circuit.

In the additive method, although the thickness of the conductor can be controlled by electroplating, there is a problem that the seed layer cannot be etched because the seed layer is composed of a layer consisting of an ultra-thin copper foil and a roughened surface of the ultra-thin copper foil. The seed layer is removed in a short time, and the circuit is also etched during etching, so it is difficult to form a fine-patterned circuit.

If the ultra-thin copper foil layer is further thinned by a semi-etching technique or the like, the etching time can be shortened, and the circuit can be suppressed from being etched. However, it is necessary to control the etching amount of the ultra-thin copper foil layer very precisely, In addition, extremely high precision is required for the foil thickness distribution of extremely thin copper foil, which is very difficult.

In addition, if the ultra-thin copper foil itself is thinned, since the etching time is shortened, the circuit can be suppressed from being etched. However, pinholes are easily generated, and the circuit is defective in the pinhole portion. In a fine-patterned circuit, even if the circuit is slightly broken, the risk of disconnection increases, and therefore a problem occurs.

In addition, both the subtractive method and the additive method have a problem in that a process of applying electroless plating and / or electroplating to via holes and non-via holes is a constant process for achieving interlayer connection during multilayering. In a required process, the ultra-thin copper foil layer is also thickened by plating, and as a result, the entire substrate becomes thicker, which hinders the increase in density.

Therefore, the development of a composite metal foil capable of manufacturing a copper-clad laminate by a simple method is highly anticipated. The copper-clad laminate is a copper-clad laminate having an ultra-thin copper layer thinner than the ultra-thin copper foil layer. If the ultra-thin copper layer is used as the seed layer of the addition method, the circuit can be removed by etching in a very short period of time. Therefore, it can be preferably used to form a fine-patterned circuit. Further, it can be suppressed during multilayering. The increase in the overall thickness makes it possible to manufacture a high-density multilayer substrate. [Patent Literature]

[Patent Document 1] JP 2009-246120 [Patent Document 2] WO2002-024444 [Patent Document 3] JP 2013-204065

Patent Document 1 discloses a composite foil with a carrier in which a Fe-Ni alloy layer, copper, or a copper alloy layer is sequentially laminated on a carrier foil via a release layer.

However, the composite foil with a carrier disclosed in Patent Document 1 has a problem in that, since a release layer is laminated on the carrier foil, the heat resistance of the release function is low when the release foil is bonded to the substrate in a high temperature and high pressure environment. The carrier foil cannot be peeled clean at the interface.

In addition, when bonding to a substrate, a roughened layer is provided on the copper or copper alloy layer. Therefore, if used as a seed layer for the addition method, the seed layer cannot be etched away in a short time, and the circuit is also It may be etched, and a fine-patterned circuit may not be formed.

In addition, even if the Fe-Ni alloy layer is to be removed by selective etching of Ni, the Fe-Ni alloy layer cannot be removed cleanly because the Fe-Ni alloy layer is an alloy.

Patent Document 2 discloses an ultra-thin copper foil with a carrier in which a peeling layer, a diffusion prevention layer, and a copper plating layer are sequentially laminated on the surface of a carrier foil, and a Ni layer can be used as the diffusion prevention layer.

However, the ultra-thin copper foil with a carrier disclosed in Patent Document 2 has a problem that, similar to the composite foil with a carrier disclosed in Patent Document 1, because a release layer is laminated on the carrier foil, the heat resistance of the peeling function is high. Low performance, the carrier foil cannot be peeled clean at the interface.

In addition, there is a problem that, because the Ni layer on the ultra-thin copper foil layer is very thin, there is a high possibility of pinholes in the Ni layer, and if pinholes are generated in the Ni layer, copper plating will occur. Layers create pinholes and cause circuit defects.

Patent Document 3 discloses a copper foil with a carrier in which a copper foil carrier, an intermediate layer on the copper foil carrier, and an ultra-thin copper foil layer on the intermediate layer are sequentially stacked, the intermediate layer being laminated on the copper foil carrier. Chrome layer or chromate layer, and Ni layer or Ni-phosphorus alloy layer.

However, in the copper foil with a carrier disclosed in Patent Document 3, because a peeling method of cohesive failure in the Ni layer or the Ni-phosphorus alloy layer is used, there may be cases where an ultra-thin copper foil layer may be used. destroyed.

In addition, the composite foils with a carrier disclosed in Patent Documents 1 to 3 have a problem in that, because an extremely thin copper foil is formed on a Ni or Ni alloy layer, the surface of the extremely thin copper foil is roughened and the Since the substrate is bonded, even if the Ni or Ni alloy layer can be selectively removed after bonding to the substrate, extremely thin copper foil and roughened particles remain, and therefore the thickness of the entire substrate increases during multilayering.

SUMMARY OF THE INVENTION The present inventors have repeatedly tried and tested a large number of trials and experiments with the technical problems of solving the above-mentioned problems as a technical problem. As a result, they have obtained an important insight that, by using a composite metal foil, the composite metal foils are sequentially stacked. A metal foil carrier, a first Ni or Ni alloy layer on at least one side of the metal foil carrier, a peeling layer on at least one side of the first Ni or Ni alloy layer, a second Ni layer, and extremely thin copper The primary particle diameter of the copper particles of the ultra-thin copper layer is 10 to 200 nm, the adhesion amount is 300 to 6000 mg / m ² , and the thickness of the second Ni layer is 0.3 to 5 mm, even at high temperatures. Because the heat resistance of the release layer is extremely high, the metal foil carrier, the first Ni or Ni alloy layer, and the release layer can be peeled off at the interface of the release layer to produce a laminated ultra-thin copper layer. And the second Ni layer metal foil laminate, and because the second Ni layer can be easily removed by selective etching, it is possible to produce a clad with a very thin copper layer that is dense and is not prone to pinholes and the like by a very simple method. Copper laminate In order to solve the above problems.

As described below, the present invention can solve the technical problems.

A first technical solution of the present invention is a metal foil carrier, a first Ni or Ni alloy layer on at least one side of the metal foil carrier, and at least one side of the first Ni or Ni alloy layer in this order. The composite metal foil of the peeling layer, the second Ni layer, and the ultra-thin copper layer, wherein the primary particle diameter of the copper particles of the ultra-thin copper layer is 10 to 200 nm, and the adhesion amount thereof is 300 to 6000 mg / m ² . The thickness of the second Ni layer is 0.3 to 5 mm.

In addition, a second technical solution of the present invention is a composite metal foil having a thickness of the first Ni or Ni alloy layer of 0.001 to 5 mm.

A third aspect of the present invention is a composite metal foil in which the release layer is a layer containing at least one of Cr and Zn.

In addition, a fourth technical solution of the present invention is a composite metal foil in which the purity of Ni in the second Ni layer is 99.6% or more.

A fifth aspect of the present invention is a composite metal foil in which a metal layer is formed between the second Ni layer and the ultra-thin copper layer.

In addition, a sixth aspect of the present invention is a method for manufacturing a metal-clad laminate, wherein the insulating resin base material is bonded to the ultra-thin copper layer of the composite metal foil by heating and compression, and then passed through The release layer peels off the release layer, the first Ni or Ni alloy layer, and the metal foil carrier to produce a metal-clad laminate.

In addition, a seventh aspect of the present invention is a method for manufacturing a copper-clad laminate, in which the second Ni layer of the metal-clad laminate is etched and removed using a Ni selective etching solution to produce a copper-clad laminate.

In addition, an eighth aspect of the present invention is a printed circuit board using the copper-clad laminated board to form a circuit.

In addition, a ninth technical solution of the present invention is a multilayer printed circuit board in which one or more circuits are further formed on a circuit of the printed circuit board.

The beneficial effect of the present invention is that because the peeling layer is sandwiched between the first Ni or Ni alloy layer and the second Ni layer, the heat resistance of the peeling layer is extremely high, so even when the glass transition temperature of the bonding is high, The metal foil carrier, the first Ni or Ni alloy layer, and the release layer can be easily peeled at the interface of the release layer without reducing the peeling function even under severe temperature conditions such as that of the substrate.

In addition, in the present invention, since the thickness of the second Ni layer is 0.3 to 5 mm, pinholes and the like are not easily generated in the second Ni layer, and pinholes can be suppressed from being generated in the extremely thin copper layer.

In addition, since the second Ni layer can be removed by using a Ni selective etching solution, a copper-clad laminated board in which an extremely thin copper layer is laminated can be manufactured by a simple method.

In addition, for the ultra-thin copper layer related to the present invention, since the primary particle diameter of the formed copper particles is as small as 10 to 200 nm, and its adhesion amount is 300 to 6000 mg / m ² , it is formed as a very dense ultra-thin copper layer. .

Note that the primary particle diameter in the present invention refers to the particle size of the smallest unit (primary particle) (31) of the precipitated copper particles that can be regarded as a particle, and the aggregate (32) of the primary particles is referred to as a secondary particle . The "dense ultra-thin copper layer" in this specification refers to a copper layer as shown in FIG. 12.

In the case of forming a circuit using the ultra-thin copper layer according to the present invention as a seed layer for the addition method, the seed layer is very thin and can be removed by etching in a very short time, so that the circuit can be suppressed from being etched and a fine pattern can be formed. Circuit.

In addition, since the ultra-thin copper layer according to the present invention is composed of dense and fine copper particles, it has excellent adhesion when bonded to a substrate.

Therefore, in the step of applying electroless plating and / or electroplating to the vias and non-vias, the multilayer is performed by using a copper-clad laminated board manufactured by bonding to the composite metal foil according to the present invention, and this step is performed between layers. The connection must be performed in a process, and even an extremely thin copper layer is thickened by plating. Since the original thickness is extremely thin, it is possible to suppress an increase in the thickness of the entire multilayer substrate, thereby achieving high density.

In addition, the ultra-thin copper layer according to the present invention may be subjected to the same surface treatment as the conventional copper foil for a printed circuit board, such as heat resistance / chemical resistance treatment, rust prevention treatment, chemical treatment, etc., and further Improve adhesion.

In addition, by setting the thickness of the first Ni or Ni alloy layer to 0.001 to 5 mm, the heat resistance of the release layer can be further improved.

In addition, when the release layer contains at least one of Cr or Zn, a composite metal foil having more excellent peeling function can be manufactured.

The copper-clad laminate according to the present invention can preferably form a circuit with a fine pattern by an addition method, and can also form a circuit by a subtractive method or other methods.

BEST MODE FOR CARRYING OUT THE INVENTION The metal foil carrier (2) of the present invention is not particularly limited, and a copper foil and a copper alloy foil formed by a rolling method and an electrolytic method can be preferably used.

The surface (hereinafter referred to as a "laminated surface") in which the various layers are laminated in the metal foil carrier may be appropriately selected as required, and may be double-sided as shown in FIG. 2.

The thickness of the metal foil carrier is not particularly limited, but is preferably 9 to 300 mm, and more preferably 12 to 70 mm.

This is because when the thickness of the metal foil carrier is less than 9 mm, wrinkles and cracks are liable to occur during lamination, and when the thickness exceeds 300 mm, the overall rigidity of the composite metal foil is too strong and difficult to use.

In addition, it is possible to apply the same surface treatment as the conventional copper foil for a printed circuit board to a surface on which a metal foil carrier is not laminated, such as roughening treatment, heat resistance / chemical resistance treatment, rust prevention treatment, and chemical treatment. Wait.

Note that when the surfaces of the second Ni layer (5) and the ultra-thin copper layer (6) are made to have a low roughness, the surface roughness Rzjis (as described in JIS-B0601 (2013) of the laminated surface is used as the metal foil carrier). Rolled copper foil and electrolytic copper foil having a ten-point average roughness) of 1.0 mm or less may suffice.

The thickness of the first Ni or Ni alloy layer (3) of the present invention is preferably 0.001 to 5 mm, and more preferably 0.005 to 3 mm.

This is because when the thickness of the first Ni or Ni alloy layer (3) is less than 0.001 mm, it is easily affected by the high temperature when bonding to the substrate, and it may be difficult to peel off from the interface of the release layer, and even if the thickness is less than 5 mm Thick, can not improve the function further.

In the heat-compressing step of bonding to the base material, as shown in FIG. 3, only the first Ni or Ni alloy layer (3) may be provided on the surface opposite to the surface on which the layers are stacked, and used as a prevention A rust-resistant (oxidized) heat-resistant layer of a metal foil carrier.

In the composite metal foil of the present invention, the metal foil carrier (2), the first Ni or Ni alloy layer (3), and the release layer (4) can be made at the interface between the release layer (4) and the second Ni layer (5). On peel.

The release layer (4) preferably contains at least one of Cr or Zn.

Examples of the layer containing Cr or Zn include a single metal layer, a hydrate layer, and an oxide layer composed of any one of Cr and Zn; and an alloy layer, a hydrate layer, and an oxide composed of these two elements Layer; or a layer of the above-mentioned single metal, hydrate, oxide, a composite of an alloy, hydrate, and oxide composed of the two elements described above.

The adhesion amount of the peeling layer is preferably 0.001 to 1000 mg / m ² , and more preferably 0.05 to 1000 mg / m ² .

This is because when the adhesion amount of the peeling layer is less than 0.001 mg / m ² , it may be difficult to peel, and even if the adhesion amount is more than 1000 mg / m ² , the function cannot be further improved.

By changing the thickness of the first Ni or Ni alloy layer (3) or the type and amount of metal of the release layer (4), the desired peel strength can be adjusted.

The peel strength after heating at 210 ° C. for 4 hours is preferably 0.1 kN / m or less, and more preferably 0.05 kN / m or less.

This is because when the peel strength is more than 0.1 kN / m, although unexpected peeling can be prevented, a large amount of force and a long time are required for peeling, resulting in a decrease in work efficiency. In addition, the substrate may be warped and strained due to the force applied during peeling.

In the second Ni layer (5), the purity of Ni is preferably 99.6% or more. This is because when the purity is low, the removal performance of selective etching may be reduced or cannot be removed.

When the second Ni layer is not removed cleanly, the risk of poor insulation (short circuit) caused by Ni remaining when the circuit is formed becomes high.

The thickness of the second Ni layer is 0.3 to 5 mm, and preferably 1 to 3 mm. This is because when the thickness is less than 0.3 mm, pinholes are likely to be generated in the second Ni layer, and when the second Ni layer has pinholes, an extremely thin copper layer is not formed where there are pinholes, which occurs. The risk of disconnection increases.

In addition, even if the thickness exceeds 5 mm, the function cannot be further improved, and the removal step by selective etching requires a long time, which is not preferable.

Among the copper particles forming the extremely thin copper layer, the primary particle diameter is preferably 10 to 200 nm, and more preferably 10 to 40 nm. Its adhesion amount is 300 to 6000 mg / m ² , and more preferably 1000 to 4000 mg / m ² .

This is because, when the primary particle diameter is less than 10 nm, since the surface energy of significant rises, and therefore can not maintain the shape as the particles, and when more than 200 nm, particles are too large, can not form a dense at 300 ~ 6000mg / m coating weight of ² Very thin copper layer.

In addition, when the adhesion amount is less than 300 mg / m ² , a dense and extremely thin copper layer cannot be formed, and when it is adhered with an adhesion amount exceeding 6000 mg / m ² , it takes a long time for removal, or due to copper particles Both of them are not preferred because conductive foreign matter occurs.

In addition, since the thickness of the ultra-thin copper layer according to the present invention is extremely thin and cannot be easily measured directly, it is expressed by the amount of adhesion.

The ultra-thin copper layer is dense and is composed of fine copper particles, so it has excellent adhesion to the substrate. However, in order to further improve the adhesion, a well-known heat-resistant surface treatment of copper foil for printed circuit boards can be applied. / Chemical resistance treatment, rust prevention treatment, chemical treatment, etc.

In addition, when the voltage at the time of plating of the ultra-thin copper layer is high due to the large surface resistance of the second Ni layer, or it is difficult to obtain adhesion, it can also be formed by a physical film formation process such as sputtering or evaporation, or In a chemical film formation process such as electroplating and electroless plating, a metal layer is provided on the second Ni layer, and an extremely thin copper layer is provided on the metal layer.

The composite metal foil, copper-clad laminate, and printed circuit board according to the present invention can be produced by the following method.

(First Ni or Ni alloy layer) By immersing the surface of the metal foil carrier in a Watt bath (240 ~ 300g / L of nickel sulfate, 40 ~ 70g / L of nickel chloride, 30 ~ 45mL / L of boric acid, pH3.8 ~ 4.2 , Bath temperature 50 ~ 60 ℃, current density 0.5 ~ 8A / dm ² ) or sulfamic acid bath (nickel sulfamate 440 ~ 500g / L, boric acid 30 ~ 50mL / L, pH 3.8 ~ 4.4, bath temperature 50 ~ 60 ° C, current density 2 ~ 40A / dm ² ), or by dipping the surface of the metal foil carrier in a hydrazine bath (as representative examples, nickel acetate 60g / L, glycolic acid 60g / L, and ethylenediaminetetraacetic acid 25g / L, hydrazine 100mL / L, pH11, bath temperature 90 ° C), and the like, an Ni layer can be formed on a metal foil carrier.

If necessary, additives such as a brightener, sodium 1-naphthalene acetate, sodium lauryl sulfate, and saccharin may be added to the Watt bath and the sulfamic acid bath.

To form the Ni alloy layer, the surface of the metal foil carrier was immersed in a Ni-P bath (nickel sulfate 20 to 300 g / L, nickel chloride 35 to 50 g / L, boric acid 30 to 50 g / L, and phosphorous acid 1 to 30 g / L, sodium acetate 1 ~ 30g / L, pH 1 ~ 5, bath temperature 40 ~ 70 ° C, current density 1 ~ 15A / dm ² ), Ni-Co bath (nickel sulfate 50 ~ 200g / L, cobalt sulfate 50 ~ 200g / L, sodium citrate 15 ~ 30g / L, pH 3 ~ 6, bath temperature 25 ~ 60 ℃, current density 1 ~ 15A / dm ² ), Ni-Mo bath (nickel sulfate 30 ~ 70g / L, sodium molybdate 30 ~ 120g / L, sodium citrate 15 ~ 30g / L, pH 7 ~ 12, bath temperature 20 ~ 50 ℃, current density 1 ~ 15A / dm ² ), Ni-Zn bath (nickel sulfate 250 ~ 300g / L, zinc sulfate 50 ~ 400g / L, sodium citrate 15 ~ 30g / L, pH 3 ~ 6, bath temperature 50 ~ 70 ℃, current density 3 ~ 15A / dm ² ) or Ni-Co-Mo bath (nickel sulfate 50 ~ 200g / L , Cobalt sulfate 50 ~ 200g / L, Sodium molybdate 30 ~ 120g / L, Sodium citrate 15 ~ 30g / L, pH 7 ~ 12, bath temperature 20 ~ 50 ℃, current density 1 ~ 15A / dm ² ), etc. Or by immersing the surface of the metal foil carrier in a Ni-P bath (as a representative example, nickel chloride 16g / L, sodium hypophosphite 24g / L, sodium succinate 16g / L, sodium malate 18g / L, pH 5 .6, bath temperature 100 ℃), Ni-B bath (as a representative example, nickel chloride 30g / L, ethylene oxide 60g / L, sodium hydroxide 40g / L, sodium borohydride 0.6g / L, bath temperature 90 ℃) like plating, Ni alloy layer can be formed on a metal foil carrier.

If necessary, you can also add an appropriate amount of brightener, saccharin, sodium 1-naphthalene acetate, and dodecyl to the Ni-P bath, Ni-Co bath, Ni-Mo bath, Ni-Zn bath, and Ni-Co-Mo bath. Additives such as sodium sulfate.

(Peeling layer) The surface on which the first Ni or Ni alloy layer is formed is immersed in 200 to 400 g / L of anhydrous chromic acid, 1.5 to 4 g / L of sulfuric acid, pH 1 to 4, bath temperature 45 to 60 ° C, and current density 10 to 40A / dm ² plating bath; anhydrous chromic acid or potassium dichromate 1 ~ 30g / L, pH 2 ~ 6, bath temperature 20 ~ 60 ℃, current density 0.1 ~ 10A / dm ² ; or heavy chromium Potassium acid 1-30 g / L, zinc sulfate 0.1-20 g / L, pH 2-6, bath temperature 20-60 ° C, and current density 0.1-10 A / dm ² can be used to form a peeling layer by plating.

(Second Ni layer) The second Ni layer can be formed by immersing the surface on which the release layer is formed in a Watt bath or a sulfamic acid bath and plating.

When formed by the electrolytic method, Ni purity can be made to a high purity of 99.6% or more.

(Ultra-thin copper layer) The ultra-thin copper layer can be formed, for example, by the method disclosed in Japanese Patent Application Laid-Open No. 1-246393. Specifically, a mixed solution of pentasodium diethylenetriamine pentaacetate 10 to 300 g / L and copper sulfate pentahydrate 10 to 100 g / L is adjusted to pH 2.5 to 13.0 by using sulfuric acid, and the bath temperature is 30 to 60 ° C, Processing at a current density of 2 to 10 A / dm ² for 1 to 120 seconds can form an extremely thin copper layer.

(Base material) The composite metal foil according to the present invention does not easily drop due to high temperature due to its peeling function. Even if a resin with a high glass transition temperature is used, it can be easily peeled off after heating and compression bonding. The material is not particularly limited and can be appropriately selected.

(Metal-clad laminate) After the ultra-thin copper layer of the composite metal foil is bonded to the base material by heating and compression, the release layer, the first Ni or Ni alloy layer, and the metal foil carrier are peeled from the interface of the release layer to produce a laminate Metal laminate (Figure 5).

(Copper-clad laminate) The metal-clad laminate is subjected to Ni selective etching to remove the second Ni layer, so that a copper-clad laminate having an extremely thin copper layer laminated on a substrate can be produced (FIG. 6).

In addition, in the present invention, a double-sided metal-clad laminate and a double-sided copper-clad laminate can also be produced by laminating a composite metal foil on both sides of a substrate.

(Printed Circuit Board) If an ultra-thin copper layer on a copper-clad laminate is used as a seed layer, a circuit with a fine pattern can be formed by an addition method (FIG. 7).

In addition, a circuit may be formed on the ultra-thin copper layer of the copper-clad laminate by a subtractive method or other methods.

(Multilayer printed circuit board) In addition, the formed circuit may be roughened, and the second base material (7 (a)) and the composite metal foil according to the present invention may be laminated on the roughened circuit by heating and compression, and may be used. The composite metal foil according to the present invention forms a second ultra-thin copper layer (6 (a)) (FIG. 8), and forms a roughened circuit in the second ultra-thin copper layer and the second substrate (FIG. 9). The non-conducting hole (12) is connected to the inner wall of the non-conducting hole by electroless plating (13) and electroplating (20) (FIG. 10), and a circuit (10 (a)) is formed on the previously formed circuit.

A circuit (10 (b)) can also be formed on the second circuit (10 (a)) by the same method (FIG. 11).

By stacking and multilayering the copper-clad laminate according to the present invention, the thickness of the entire multilayer substrate can be suppressed, and the density of the multilayer substrate can be increased.

In order to manufacture a multilayer printed wiring board, a conventional copper foil for a printed wiring board may be laminated without being limited to the composite metal foil according to the present invention.

[Examples] Examples and comparative examples of the present invention are shown below, but the present invention is not limited thereto.

(Example 1) As a metal foil carrier, an electrolytic copper foil having a thickness of 18 mm was used.

The surface of the copper foil carrier was immersed in a Watt bath (bath composition: 250 g / L of nickel sulfate, 50 g / L of nickel chloride, 30 mL / L of boric acid, pH 4.0, and bath temperature of 50 ° C.) under the conditions of a current density of 5 A / dm ² Next, a process was performed for 30 seconds to form a first Ni layer.

The surface on which the first Ni layer was formed was immersed in a plating bath having 20 g / L of potassium dichromate, pH 4.5, and a bath temperature of 30 ° C., and treated at a current density of 1 A / dm ² for 2 seconds to form A hydrate hydrate composite was used as a release layer.

The surface on which the release layer was formed was immersed in the same Watt bath as the first Ni layer, and treated for 120 seconds at a current density of 5 A / dm ² to form a second Ni layer.

The surface on which the second Ni layer was formed was immersed in a plating bath of 20 g / L of diethylene triamine pentaacetate, 30 g / L of copper sulfate pentahydrate, pH 4.0, and a bath temperature of 40 ° C. at a current density of 2 A / dm ² for 30 seconds to form an extremely thin copper layer.

The primary particle diameter of the copper particles forming the extremely thin copper layer is 10 to 40 nm.

(Example 2) It differs from Example 1 in that it was immersed in a plating bath having 15 g / L of potassium dichromate, 10 g / L of zinc sulfate, pH 4.9, and a bath temperature of 30 ° C at a current density of 0.5 A / dm ^The process was performed under the conditions of 2 for 2 seconds to form a peeling layer composed of a composite of Cr and Zn, except that it was the same as the production method of Example 1. (Example 3) The difference from Example 1 is that a plating bath immersed in nickel sulfate 30 g / L, phosphorous acid 2 g / L, sodium acetate 10 g / L, pH 4.5, and a bath temperature of 30 ° C was subjected to a current density The process was performed under the conditions of ² A / dm ² for 5 seconds to form an alloy layer composed of Ni and P. Other than that, the manufacturing method was the same as that of Example 1. (Example 4) The difference from Example 1 is that a plating bath immersed in nickel sulfate 50g / L, cobalt sulfate 50g / L, citric acid 30g / L, pH 4.0, and a bath temperature of 30 ° C was subjected to a current density The process was performed under the conditions of ² A / dm ² for 2 seconds to form an alloy layer composed of Ni and Co. Other than that, the manufacturing method was the same as that of Example 1. (Example 5) The difference from Example 1 is that it was immersed in a plating bath of 50g / L of nickel sulfate, 30g / L of sodium molybdate, 30g / L of citric acid, pH 9.0, and a bath temperature of 30 ° C. The process was carried out for 2 seconds under a condition of a density of 7 A / dm ² to form an alloy layer composed of Ni and Mo. The manufacturing method was the same as in Example 1 except that the layer was made of Ni and Mo. (Example 6) The difference from Example 1 is that a plating bath immersed in 250g / L of nickel sulfate, 50g / L of zinc sulfate, 30g / L of citric acid, pH 4.0, and a bath temperature of 50 ° C was subjected to a current density The process was performed under the conditions of 5 A / dm ² for 2 seconds to form an alloy layer composed of Ni and Zn. The manufacturing method was the same as that of Example 1 except that the alloy layer was formed of Ni and Zn. (Example 7) The difference from Example 1 was that it was immersed in 50g / L of nickel sulfate, 50g / L of cobalt sulfate, 30g / L of sodium molybdate, 30g / L of citric acid, pH 9.0, and bath temperature of 30 ° C. The plating bath was treated in the same manner as in Example 1 except that it was treated for 2 seconds at a current density of 7 A / dm ² to form an alloy layer composed of Ni, Co, and Mo. (Examples 8 to 15) The difference from Example 1 is that the thickness of the first Ni layer, the adhesion amount of the peeling layer, or the adhesion amount of the ultra-thin copper layer were changed according to the description in Table 1. The manufacturing method of Example 1 is the same. (Example 16) The difference from Example 1 is that a copper layer is provided between the second Ni layer and the ultra-thin copper layer by a Cu sputtering method, and the manufacturing method is the same as that of Example 1.

(Example 17) The difference from Example 1 is that a copper layer was provided between the second Ni layer and the ultra-thin copper layer by a Cu vapor deposition method, except that it was the same as the manufacturing method of Example 1.

(Comparative Example 1) The difference from Example 1 is that it is the same as the manufacturing method of Example 1 except that no peeling layer was formed. (Comparative Example 2) The difference from Example 1 is that the first Ni layer was not formed, and the manufacturing method was the same as that of Example 1 except that the first Ni layer was not formed. (Comparative Examples 3 to 8) The difference from Example 1 is that the thickness of the first Ni layer, the adhesion amount of the peeling layer, or the adhesion amount of the ultra-thin copper layer were changed according to the description in Table 1. The manufacturing method of Example 1 is the same.

(Peel strength) Each composite metal foil of Examples and Comparative Examples was heated in an air energy oven heated to 210 ° C for 2 hours and 4 hours.

Then, the heated composite metal foil was fixed to a flat support plate, and the peel strength was measured using PT50N manufactured by Minebea Corporation in accordance with the test method for peel strength of JIS-C6481 (1996). In addition, whether or not it can be peeled off is evaluated, and ○ indicates that it can be peeled off, and x indicates that it cannot be peeled off.

The metal-clad laminate from which the copper foil carrier was peeled was immersed in a Ni selective etching solution (MEC REMOVER NH-1866, manufactured by MEC Co., Ltd.), and shaken to determine the amount required for the removal of the second Ni layer. Time (seconds).

In addition, for a copper-clad laminated board from which the second Ni layer has been removed, an ultra-thin copper layer with an ultra-thin pattern as a seed layer is formed by an addition method to form a circuit with an ultra-fine pattern of L / S = 10mm / 10mm. ○ indicates that L / S = 10mm / 10mm can be achieved, and X indicates that L / S = 10mm / 10mm cannot be achieved.

Table 1 shows the composite metal foils of the respective examples and comparative examples. Table 2 shows the evaluations of the respective examples and comparative examples.

【Table 1】 * 1 Cu sputtering method * 2 Cu evaporation method

【Table 2】

From the examples and comparative examples, it can be proved that the composite metal foil according to the present invention has a low peel strength even after heating at 210 ° C for 4 hours, can be easily peeled off, and is suitable for forming ultra-fine particles such as L / S = 10mm / 10mm. Patterned circuit. In addition, in Comparative Example 4 and Comparative Example 6, the thickness of the Ni layer was very thick, which resulted in an increase in cost, which was not preferable. Especially in Comparative Example 6, it takes a long time to remove the second Ni layer, which is not preferable. [Industrial availability]

The composite metal foil according to the present invention has a low peeling strength even when the peeling function of the peeling layer is not reduced even at a high temperature. Therefore, even if a substrate having a high glass transition temperature is bonded at a high temperature, its peeling strength is low and stable, and it can be easily removed. The interface of the release layer peels off the metal foil carrier, the first Ni or Ni alloy layer, and the release layer. In addition, since the second Ni layer is removed by selective etching, a copper-clad laminated board in which a dense ultra-thin copper layer is laminated can be manufactured by a simple method. In addition, since the copper layer of the copper-clad laminated board manufactured using the composite metal foil according to the present invention is extremely thin, when the ultra-thin copper layer is used as a seed layer to form a circuit by the addition method, the etching process can be performed in a short The seed layer is removed within a time and the circuit can be suppressed from being etched, so it is suitable to form a circuit with an ultra-fine pattern such as L / S = 10mm / 10mm; pinholes are not easy to occur, and a printed circuit board with a low risk of disconnection can be manufactured; and For multilayering, when electroless plating and / or electroplating is applied to vias and non-vias for interlayer connection, the effect of thickening the ultra-thin copper layer can also be minimized, thereby suppressing the manufacture of multilayer substrates. In this case, the thickness of the entire substrate is increased, so that a high-density multilayer substrate can be manufactured. Therefore, it can be said that the present invention is an industrially applicable invention.

1‧‧‧ composite metal foil

2‧‧‧ metal foil carrier

3‧‧‧ the first Ni or Ni alloy layer

4‧‧‧ peeling layer

5‧‧‧Second Ni layer

6‧‧‧ Very thin copper layer

6 (a) ‧‧‧The second extremely thin copper layer

7‧‧‧ substrate

7 (a) ‧‧‧Second substrate

8‧‧‧ metal-clad laminate

9‧‧‧ copper clad laminate

10‧‧‧Circuit

10 (a) ‧‧‧Second layer circuit

10 (b) ‧‧‧Third layer circuit

12‧‧‧ non-via

13‧‧‧electroless plating

16‧‧‧Multilayer Printed Circuit Board

20‧‧‧Plating

31‧‧‧ primary particles

32‧‧‧ secondary particles

Fig. 1 is a schematic diagram of a composite metal foil; Fig. 2 is a schematic diagram of a mode of the composite metal foil; Fig. 3 is a schematic diagram of a mode of the composite metal foil; 5 is a schematic diagram of a metal-clad laminated board; FIG. 6 is a schematic diagram of a copper-clad laminated board; FIG. 7 is a schematic diagram of a printed circuit board on which a circuit is formed; and FIG. 8 is a diagram of a second substrate and a second extremely thin copper layer 9 is a schematic diagram of non-conducting holes formed; FIG. 10 is a schematic diagram of applying electroless plating and electroplating to the inner wall of the non-conducting holes; FIG. 11 is a schematic diagram of a multilayer printed circuit board; FIG. 12 is an electrode of the present invention FE-SEM photograph (300,000 times) of a thin copper layer.

Claims (9)

A composite metal foil is sequentially laminated with a metal foil carrier, a first Ni or Ni alloy layer on at least one side of the metal foil carrier, and at least one side of the first Ni or Ni alloy layer. The peeling layer, the second Ni layer, and the ultra-thin copper layer, wherein the primary particle diameter of the copper particles of the ultra-thin copper layer is 10 to 200 nm, and the adhesion amount thereof is 300 to 6000 mg / m ² . The thickness of the two Ni layers is 0.3 to 5 mm. The composite metal foil according to claim 1, wherein a thickness of the first Ni or Ni alloy layer is 0.001 to 5 mm. The composite metal foil according to claim 1 or 2, wherein the release layer is a layer containing at least one of Cr and Zn. The composite metal foil according to any one of claims 1 to 3, wherein the purity of Ni of the second Ni layer is 99.6% or more. The composite metal foil according to any one of claims 1 to 4, wherein a metal layer is formed between the second Ni layer and the ultra-thin copper layer. A method for manufacturing a metal-clad laminated board, wherein the insulating resin base material is heated and compressed to be bonded to the ultra-thin copper layer of the composite metal foil according to any one of claims 1 to 5, and then passed through The release layer peels off the release layer, the first Ni or Ni alloy layer, and the metal foil carrier to produce a metal-clad laminate. A method for manufacturing a copper-clad laminated board, wherein the second Ni layer of the metal-clad laminated board manufactured by the method according to claim 6 is etched and removed using a Ni selective etching solution to manufacture a copper-clad laminated board. A printed circuit board using a copper-clad laminated board manufactured by the method described in claim 7 to form a circuit. A multilayer printed circuit board, wherein more than one circuit is formed on the circuit of the printed circuit board according to claim 8.