JP2631061B2 - Copper foil for printed circuit and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copper foil for a printed circuit and a method for producing the same, and more particularly, to a method for producing a copper-clad laminate, which maintains a high adhesive strength between the copper foil and the substrate. In particular, the present invention relates to a copper foil for a printed circuit capable of providing a copper-clad laminate excellent in migration resistance and a method for producing the same.

[0002]

2. Description of the Related Art As electronic components mounted on printed wiring boards have become smaller, higher in density and higher in performance, requirements for the quality of copper foil as a conductive circuit material have become more stringent, resulting in higher reliability. Characteristics are required.

[0003] The most basic required characteristic is that the adhesive strength between the copper foil and the resin substrate is excellent. In this regard, the copper foil is heated and pressurized with the resin base material, and not only the adhesive strength immediately after lamination, but also under severe environmental conditions such as being immersed in chemicals such as acids and alkalis or being heated Even after being placed, it is still an extremely important issue to maintain high bonding strength in order to obtain high quality reliability.

[0004] Therefore, as a general means for solving the above-mentioned problems, a roughening treatment of a surface to be bonded of a copper foil to be laminated on a resin substrate, for example, a method of coating a copper foil in advance by cathodic electrolysis using a copper plating solution. A process of electrodepositing copper particles on the bonding surface has been performed. As a result, the bonding strength is remarkably improved due to the increase in the surface area of the copper foil surface and the anchoring effect provided by the granular material.

[0005] However, the formation of the rough surface alone does not improve the adhesive strength characteristics such as chemical resistance and heat resistance, and increases the so-called adhesive strength deterioration rate, and does not satisfy a practical level.

For this reason, after the above-mentioned surface roughening treatment, various kinds of surface treatment layers are formed to reduce the rate of deterioration of adhesive strength. Regarding the formation of the surface treatment layer on the copper foil surface, many proposals have been made conventionally.
For example, a copper foil having a chromate layer formed on a roughened surface (Japanese Patent Publication No. 61-33908), and a copper foil having a zinc layer formed on a roughened surface and further forming a chromate layer (see JP-A-61-33906) has been proposed. However, while these copper foils according to the prior art are effective in improving some of the above-mentioned required characteristics, they may sometimes worsen.

Specifically, a copper foil having a chromate layer is insufficient in the effect of improving the adhesive strength, particularly after long-time heating. Further, although the adhesive strength after the above-mentioned heating is improved to some extent, the adhesive strength after immersion in hydrochloric acid, which is regarded as an important chemical resistance, is significantly reduced, and the copper foil having a chromate layer formed thereon after the formation of the zinc layer is significantly deteriorated. The rate may be lower than the practical level, and does not sufficiently correspond to high quality and high reliability.

On the other hand, a copper foil obtained by forming a cobalt layer containing either molybdenum or tungsten or both on the surface of the copper foil (Japanese Patent Publication No. 2-24037)
And a copper foil obtained by forming a nickel layer containing molybdenum (Japanese Patent Publication No. 62-142389) are also known.

The adhesive strength characteristics obtained from these copper foils are as follows:
The characteristic characteristic of the metal component in each layer is exhibited, and after the heat treatment for a long time, the effect of suppressing the deterioration after immersion in hydrochloric acid is effective, but the disadvantage that the deterioration after immersion in an alkali solution such as an aqueous solution of potassium cyanide tends to increase is disadvantageous. is there.

[0010] It is strongly desired that copper foils for printed circuits have excellent electrical characteristics in addition to adhesive strength characteristics. This is one of the electrical characteristics because the circuit width of copper foil, which is the conductor of the printed wiring board, and the spacing between them are becoming smaller and finer, and the thickness of the resin insulation layer is also becoming increasingly thinner. It is an important requirement to have excellent migration resistance.

For example, in a metal-based printed wiring board using a metal base such as an aluminum plate or an iron plate as a substrate, a thin insulating layer such as a resin insulating layer is provided between the metal base and the copper foil. When such a wiring board is made of a copper foil having a formation layer according to the prior art, the interlayer insulating property between the metal base and the copper foil is not sufficient because the thickness of the insulating layer is small, and migration of the copper foil is difficult. There is a disadvantage that the degree of progress is fast. In particular, in a wiring board using a copper foil proposed in Japanese Patent Publication No. 2-24037, the insulation performance is significantly reduced due to migration, and the reliability of the insulation characteristics is significantly reduced. Further, the copper foil having a nickel and molybdenum layer disclosed in Japanese Patent Publication No. 62-142389 still has room for improvement.

The term "migration" means that when a potential difference is generated between circuits or between layers of a printed wiring board, when moisture or moisture is present, the copper foil serving as a circuit is ionized and eluted. It is reduced over time to become a metal or a compound and grows in a dendritic manner. If this reaches and adheres to the other metal body, it causes an extremely fatal defect in quality, that is, a short-circuit defect. This is the occurrence of a short circuit accident due to so-called copper ion migration.

Originally, in order to prevent such a situation from occurring, it is necessary to prevent a polymer insulating resin or a base material which is laminated and adhered to the copper foil from absorbing moisture at all, or to prevent the mixing of moisture. It is desirable to keep
At present it is very difficult.

On the other hand, a copper foil having a copper alloy layer showing a relatively good tendency in migration resistance is also disclosed. For example, a copper foil having a brass layer (copper-zinc alloy layer) on the copper foil surface (Japanese Patent Publication No. 51-35711) is also known. In the case of this copper foil, although various characteristics required for the adhesive strength are almost satisfied, there is still room for improvement. Regarding migration resistance, this brass layer is an alloy of copper and zinc with copper as one of the main components, and there is no preventive measure against migration of copper ions.
It is expected that no improvement in insulation performance can be expected. in addition,
This brass layer is formed by electrodeposition using a plating bath containing a cyanide compound, and in terms of safety and health, there is a high risk of occurrence of pollution, and the obstacles in copper foil characteristics and production have not been overcome. .

[0015]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned drawbacks of the prior art, maintain a high adhesive strength between a copper foil and a resin substrate, and provide a copper foil for a printed circuit excellent in migration resistance. Is to provide. Another object of the present invention is to provide a method for producing the copper foil for printed circuits.

[0016]

The present inventors have conducted various studies in order to solve the above-mentioned drawbacks of the prior art, and have completed the present invention.

That is, the present invention provides a copper foil for a printed circuit characterized by having a ternary alloy coating layer composed of nickel, molybdenum and cobalt on the surface of the copper foil.

The present invention also provides a copper foil for a printed circuit having a chromate treatment layer on the ternary alloy coating layer, and a chromate treatment layer and a silane coupling agent treatment layer on the ternary alloy coating layer in this order. A copper foil for a printed circuit is provided.

Hereinafter, the copper foil for a printed circuit of the present invention will be described in detail.

The copper foil applied to the present invention is mainly an electrolytic copper foil,
Rolled copper foil. Also, the surface of the substrate is made of aluminum or plastic film by means of electroplating, electroless plating, vacuum evaporation, sputtering, or the like.
It may be a composite foil provided with an extremely thin copper layer of about 0 μm.

It is desirable to use a copper foil having a rough surface formed on at least one surface of the copper foil in advance using electrochemical or mechanical means. The copper foil for a printed circuit is molded into a copper-clad laminate by applying heat and pressure to a resin substrate or the like described later. By using a copper foil having a roughened surface, the adhesive strength between the copper foil and the resin substrate is improved.

On the other hand, the thickness of the copper foil is not particularly limited, but is usually 3 to 70 μm. Depending on the application, it can be used up to a foil thickness exceeding 70 μm,
It can be selected as appropriate.

The copper foil for a printed circuit of the present invention has a ternary alloy coating layer (hereinafter abbreviated as Ni-Mo-Co layer) composed of nickel, molybdenum and cobalt on at least one of the surfaces of the copper foil. . This Ni-Mo-Co layer does not impair the state in which the copper foil surface is roughened in advance, in other words, it can sufficiently exhibit the adhesive strength with the resin base material resulting from the anchoring effect brought about by the rough surface formation. It is preferable to use a thin layer having a possible thickness. The preferred thickness is
0.001 to 0.03 μm. The Ni-Mo-Co layer has excellent chemical resistance, and can reduce the adhesive strength, that is, the deterioration rate, even when immersed in, for example, hydrochloric acid or an aqueous solution of potassium cyanide. It is also a component that has excellent heat resistance and can prevent deterioration of its adhesive strength even when it is held at a high temperature for a long time, for example. In particular, nickel is a component that exhibits an excellent effect of improving migration resistance.

[0024] shows a preferred range of the metal content of the Ni-Mo-Co layer, composed of nickel 30~1200μg / dm ² molybdenum 30~1000μg / dm ² and a cobalt 30~1000μg / dm ^2.

Here, the function of each metal component will be described. Since the Ni-Mo-Co layer is a ternary alloy layer,
It is clear that the effect provided by this layer is a synergistic effect of each metal component, and the amount of each metal component and its influence cannot be explained unconditionally. It can be considered as follows.

When nickel has a metal content of less than 30 μg / dm ² in the Ni—Mo—Co layer, the effect of mainly preventing migration is attenuated and the insulation performance may be reduced. On the other hand, when it exceeds 1200 μg / dm ² , although it depends on the amount of components other than nickel, there may be a disadvantage that it does not dissolve in a general-purpose etching solution within a predetermined time during etching.

Molybdenum has a metal content of 30 μg /
If it is less than dm ^{2, the} rate of deterioration of the adhesive strength after long-time heating may increase. If it exceeds 1000 μg / dm ² , the rate of deterioration of the alkali resistance, for example, the strength of the adhesive strength after immersion in an aqueous potassium cyanide solution may increase. However, this may hinder practical use.

Cobalt has a metal content of 30 μg / d
If it is less than m ^{2, the} rate of deterioration of the adhesive strength after heat treatment for a long time may be particularly large, and if it exceeds 1000 μg / dm ² , the deterioration of the adhesive strength after heat treatment or chemical treatment for a long time may occur. In some cases, and, from an economic standpoint, the cost of production.

By keeping the metal content of the three components in the above range, Ni-Mo-Co is particularly excellent in effects such as improvement of adhesive strength and prevention of migration, which cannot be achieved by the conventional binary alloy layer. A layer is obtained. Particularly preferred Ni-Mo-
The range of the metal content of the Co layer is as follows: nickel 60 to 1000 μg / dm ² molybdenum 60 to 600 μg / dm ² and cobalt 60 to 600 μg / dm ² .

The Ni-Mo-Co layer containing these three metals in the above-mentioned preferred range or particularly preferred range is analyzed by an ESCA analyzer. However, it has been confirmed that most of the lower layer has an alloy structure composed of nickel, molybdenum and cobalt. It has been found that the thickness is approximately 0.001 to 0.03 μm. In addition, the appearance hue of this layer varies depending on the metal content that varies depending on the selection of the bath composition and the electrolytic conditions of the copper foil of the present invention, which will be described later, in the rough surface forming state of the copper foil and the method for obtaining the copper foil of the present invention. ~ Brown to grayish brown.

Further, the present invention further provides a printed circuit copper foil having a chromate treatment layer on the Ni-Mo-Co layer, and a printed circuit copper foil further having a silane coupling agent treatment layer on the chromate treatment layer. To provide.

The copper foil for a printed circuit according to the present invention will be described. In the case where a chromate-treated layer is provided on a Ni-Mo-Co layer, the effect of simultaneously improving rust prevention and adhesive strength, and the effect of an alkali solution or acid The effect of reducing the deterioration rate of the adhesive strength of the chemical resistance after immersion in the liquid is also obtained.
Further, when the silane coupling agent-treated layer is provided on the chromate-treated layer, the adhesive strength characteristics can be remarkably improved, and the effect of significantly improving the quality reliability of the copper foil for printed circuits can be obtained.

This chromate-treated layer is made of chromium oxide and chromium hydroxide, and the preferable range of the metal content measured using chromium as a metal is 10 to 90 μg / dm.
² , particularly preferably in the range of 30 to 60 μg / dm ² .

The silane-coupling-agent-treated layer is obtained by applying and drying an aqueous solution of the silane coupling agent described below diluted with a predetermined amount of water or the like, preferably 0.001 to 5% (by weight). Particularly preferred is a silane-coupling-agent-treated layer applied and dried from a 0.01 to 3% (by weight) aqueous solution in consideration of the improvement of the adhesive property and economic efficiency.

Next, the method for producing a copper foil for a printed circuit according to the present invention will be described. The feature of the method is that the copper foil is immersed in a plating bath in which nickel ions, molybdate ions and cobalt ions coexist, The object of the present invention is to form a ternary alloy coating layer composed of nickel, molybdenum, and cobalt on at least one copper foil surface by performing a treatment.

Further, the present invention provides a method for producing a copper foil for a printed circuit, comprising forming a chromate treatment layer by subjecting the coating layer to a cathode treatment in an aqueous solution containing hexavalent chromium ions, and further comprising the chromate treatment layer. Another object of the present invention is to provide a method for producing a copper foil for a printed circuit, on which a silane coupling agent treated layer is further formed.

Hereinafter, a method for producing a copper foil for a printed circuit according to the present invention will be described in detail. Using the copper foil material described above,
If necessary, a rough surface is formed in advance. For example, using an electrolytic copper foil, this is a copper sulfate plating bath, a copper pyrophosphate plating bath,
Immerse in a copper sulfamate plating bath, copper citrate plating bath, and perform a cathode treatment on at least one surface of the copper foil,
A so-called roughened copper foil obtained by electrodepositing dendritic to granular copper particles as needed on the copper foil surface is prepared. Then, a Ni-Mo-Co layer is formed on the rough surface of the copper foil.

In manufacturing the copper foil for a printed circuit of the present invention, an Ni-Mo-Co layer can be formed by an electroplating method, a chemical plating method, a vapor deposition method, a sputtering method, a metallikon method, or the like. However, among these, the method of the present invention, which is carried out by a cathodic electrolytic treatment by an electroplating method, is practically advantageous in terms of mass productivity and economy.

The manufacturing method of the present invention is carried out by forming an electrodeposition using this electroplating method. Therefore, a plating bath is first built.

Examples of the plating bath include an aliphatic oxyacid bath such as oxalic acid, glycolic acid, lactic acid, citric acid and malic acid, a gluconic acid bath, a sulfamic acid bath and a pyrophosphoric acid bath. Among them, it is desirable to use a citric acid bath in consideration of bath management, environmental problems, wastewater treatment, and the like.

The case where a citric acid bath is used will be described. Citric acid, sodium salt and potassium salt of citric acid,
Select at least one from ammonium salts and the like,
Dissolve in a predetermined amount of water for use. Usage is 10-100
g / l, preferably in the range of 10 to 50 g / l, from the viewpoints of electrodeposition formation and economy.

The metal ion sources coexisting therewith are, as described above, three types of nickel ions, molybdate ions and cobalt ions. Examples of the chemicals that can be used as the metal ion source are nickel sulphate. , Nickel chloride, nickel carbonate, nickel acetate, nickel formate and the like.

As the molybdate ion source, sodium molybdate, potassium molybdate, ammonium molybdate and the like can be used.

As a cobalt ion source, cobalt sulfate;
Cobalt acetate, cobalt sulfamate, cobalt chloride, diammonium cobalt sulfate, cobalt gluconate and the like can be used.

Each of these ion source chemicals is dissolved in a predetermined amount of water and used as a plating bath for electrodepositing a Ni—Mo—Co layer.

A Ni--Mo--Co layer is formed by immersing a copper foil in this plating bath and performing a cathodic electrolysis treatment. Preferable examples of the plating bath composition and electrolysis conditions are as follows. (
Parentheses indicate particularly preferred ranges.

Nickel sulfate hexahydrate 1-100 g / l (5-50 g / l) Sodium molybdate dihydrate 0.5-20 g / l (1-10 g / l) Cobalt sulfate heptahydrate 0.5 to 100 g / l (1 to 50 g / l) Trisodium citrate dihydrate 10 to 100 g / l (20 to 50 g / l) Bath temperature 10 to 80 ° C (20 to 40 ° C) pH 3 ７7 (4 to 6.5) Cathode current density 1 to 20 A / dm ² ( ^{2 to} 10 A / dm ² ) Electrolysis time 1 to 60 seconds (1 to 10 seconds) Anode Platinum-based insoluble anode Cathode Electrolytic copper foil or rolled copper Foil

The range of the content of each metal in the Ni—Mo—Co layer is as described above, and it is important to keep within this range. Therefore, adjustments to increase or decrease the metal content of the Ni-Mo-Co layer are usually made by adjusting the amount of each metal ion (concentration of each chemical) in the plating bath, cathode current density, voltage, electrolysis time, pH, bath temperature. , Stirring and the like are appropriately varied. Therefore, the content of each metal in the Ni-Mo-Co layer and the quantification of the metal components in the plating bath are periodically performed, and if necessary, replenishment of the metal components in the plating bath and appropriate selection of electrolysis conditions. It is desirable to mass-produce the copper foil of the present invention.

In carrying out the manufacturing method of the present invention for forming a Ni—Mo—Co layer, for example, a copper foil wound into a coil having a predetermined thickness and width is provided as necessary. Copper foil consisting of a finger removal tank, pickling tank, water washing tank, surface-treated copper plating tank, and a washing tank followed by a plating tank that forms a Ni-Mo-Co layer, a water washing tank, and a drying device. It is preferable that the processing apparatus is driven at a constant speed and is continuously wound into a coil shape to manufacture.

In the method of the present invention, the formation of the chromate-treated layer or the chromate-treated layer and the silane coupling agent-treated layer on the Ni-Mo-Co layer is performed in any case.
After forming the o-Co layer, it is performed through water washing.

More specifically, first, the chromate treatment layer is formed using an aqueous solution containing hexavalent chromium ions. Although the formation of the chromate treatment layer is possible only by immersion treatment,
It is preferably carried out according to the method of the invention by cathodic treatment. The plating bath composition and the electrolysis conditions at this time are as follows. () Shows a particularly preferred range.

Sodium dichromate 0.1 to 50 g / l (1 to 5 g / l) or chromic acid, potassium chromate pH (adjusted with sulfuric acid or caustic soda) 1 to 13 (3 to 12) Bath temperature 0 to 60 ° C (10 to 40 ° C) Cathode current density 0.1 to 50 A / dm ² (0.2 to 5 A / dm ² ) Electrolysis time 0.1 to 100 seconds (1 to 10 seconds)

By the above operation, a chromate-treated layer is formed on the Ni-Mo-Co layer, and this is dried to produce the copper foil of the present invention.

According to still another method of the present invention, a chromate-treated layer is formed, washed with water, and then a silane coupling agent-treated layer is formed on the chromate-treated layer. Examples of the silane coupling agent used for forming the silane coupling agent-treated layer include, for example, 3-aminopropyltriethoxysilane, 3-glycidoxy described in Japanese Patent Publication No. 60-15654 previously proposed by the present applicant. Examples thereof include propyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, and N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane. At least one of these silane coupling agents is selected and used as an aqueous solution. The concentration is usually 0.1.
It is used in a concentration of 001 to 5% by weight, preferably 0.01 to 3% by weight. This aqueous solution is applied to the chromate treatment layer by spraying, dipping or the like. After applying,
By drying, the copper foil of the present invention in which a chromate treatment layer and a silane coupling agent treatment layer are sequentially formed on the Ni-Mo-Co layer is manufactured.

The formation of the chromate-treated layer and the formation of the silane-coupling agent-treated layer can further improve the adhesive strength characteristics, which is the object of the present invention. If necessary for the plating bath for forming the chromate treatment layer, zinc ions, molybdate ions, etc. are added to the plating bath.
Cathode treatment may be performed under the above electrolytic conditions in the presence of 1 to 10 g / l to form a chromate treatment layer containing zinc or molybdenum.

The copper foil obtained by the method of the present invention is laminated with a resin base material as a copper foil for printed circuits in the production of various copper-clad laminates. Saturated polyester, thermosetting resin such as silicon, polyethylene, saturated polyester, thermoplastic resin such as polyether sulfone, as a substrate, paper, glass, glass cloth, glass woven cloth, polyimide polyester film and the like, or aluminum, Examples thereof include those based on a metal plate such as iron.

[0057]

The present invention will be described below in more detail with reference to examples.

Example 1 An electrolytic copper foil having a thickness of 35 μm was immersed in a copper sulfate plating bath, and granular copper was previously electrodeposited on one side of the copper foil by cathodic electrolysis to form a rough surface. Trisodium citrate in a plating bath having the following composition as is also shown in Table 1 by using this copper foil _{(Na 3 C 6 H 5 O} 7 · 2H 2 O) 30g / l nickel sulfate (NiSO ₄ · 6H ₂ O) 30 g / l Sodium molybdate (Na ₂ MoO ₄ .2H ₂ O) 3 g / l Cobalt sulfate (CoSO ₄ .7H ₂ O) 7 g / l A copper foil is immersed, pH 6.0 as the electrolysis conditions, bath temperature 30
C., a current density of 2 A / dm ² and an electrolysis time of 8 seconds were subjected to cathodic electrolysis to form a Ni—Mo—Co layer on the rough surface. After immediately washing with water, sodium dichromate _{(Na 2 Cr 2 O 7 ·} 2H 2 O) 3.5g /
The aqueous solution was adjusted to pH 5.7 and the temperature was set to 26 ° C., and the obtained copper foil was immersed in the solution, subjected to cathodic electrolysis with a current density of 0.5 A / dm ² and an electrolysis time of 5 seconds to form a Ni-Mo-Co layer To form a chromate treatment layer. After sufficiently washing this copper foil with water, a 0.15% (by weight) aqueous solution of 3-glycidoxypropyltrimethoxysilane (liquid temperature: 25 ° C.) is further applied on the chromate-treated layer by spraying, and the drying temperature is immediately set to 100 ° C. For 5 minutes to produce a copper foil of the present invention in which a Ni—Mo—Co layer, a chromate treatment layer, and a silane coupling agent treatment layer were sequentially formed on the rough side of the copper foil.

Using this copper foil as a test piece, the metal content of the adhered component formed on the copper foil surface was quantitatively analyzed by an ICP analyzer, and as shown in Table 1, nickel 500 μg / dm ² molybdenum 260 μg / dm ² cobalt was 290 μg / dm ² .

The chromium metal content is 40 μg / dm.
^{Was 2} . Next, this copper foil was treated with a FR-4 grade epoxy resin-impregnated glass substrate at a temperature of 168 ° C. and a pressure of 38 kg /.
The copper-clad laminate was produced by laminating at ² cm ² .

The copper-clad laminate was subjected to the following tests, and the results are shown in Table 1 collectively. 1. Adhesive strength test (peel width 1mm, JIS C
6481) Normal --- --- Adhesive strength after lamination [a (kgf / c
m)] Deterioration rate after immersion in hydrochloric acid ---- 6 N hydrochloric acid aqueous solution (temperature 2
5 [deg.] C.) for 1 hour.
gf / cm)], and the deterioration rate (%) = ｛(ab)
/ A｝ × 100. Deterioration rate after immersion in potassium cyanide --- Adhesive strength [c (kgf / cm)] after immersion for 0.5 hour in a 10% aqueous solution of potassium cyanide (temperature 70 ° C.) was measured, and the degradation rate (%) = {(Ac) / a} × 100. Deterioration rate after heat treatment Adhesive strength [d (kgf / cm)] after holding for 240 hours in a temperature chamber at a temperature of 177 ° C. was measured, and degradation rate (%) =
{(Ad) / a} × 100. Deterioration rate after boiling treatment Adhesive strength after holding in boiling water for 2 hours [e (kgf /
cm)], and the deterioration rate (%) = {(ae) / a}
× 100.

[0062] 2. Heat discoloration test on copper foil-removed surface Copper-clad laminate is immersed in an etching solution (cupric chloride), copper foil is removed, washed with water, and kept in a constant temperature bath at a temperature of 160 ° C. for 2 hours. The discoloration of the foil-removed surface was observed.
○ good × discolored Migration resistance test Using the apparatus shown in FIG. 1, the copper foil test piece 1 folded in half so that each treatment layer formed on the rough surface is on the outside is used as an anode, the iron plate 2 is used as a cathode, and the anode and the cathode are used. After adjusting the gap to 2 mm, sandwich the glass plate 3 from both sides, and add distilled water 4 to the gap.
Was satisfied, a constant voltage (20 V) was applied between both electrodes, and the time (second) until the current increased was measured. The earlier the time during which the current rises, the faster the migration progresses, indicating that the insulation performance is significantly reduced.

Example 2 Using the same copper foil as in Example 1, the surface was roughened in the same manner as in Example 1, and the plating bath composition and electrolysis conditions shown in Table 1 were used.
After forming the Ni-Mo-Co layer, washing and drying were performed in the same manner as in Example 1. Using the obtained copper foil as a test piece, a metal content measurement and a property test were carried out in the same manner as in Example 1, and the results are shown in Table 1.

Example 3 Using the same copper foil as in Example 1, the surface was roughened in the same manner as in Example 1, and the plating bath composition and electrolysis conditions shown in Table 1 were used.
After forming a Ni-Mo-Co layer and washing with water, a chromate-treated layer similar to that of Example 1 was formed, washed with water and dried. Using the obtained copper foil as a test piece, a metal content measurement and a property test were carried out in the same manner as in Example 1, and the results are shown in Table 1.

Example 4 Using the same copper foil as in Example 1, the surface was roughened in the same manner as in Example 1, and the plating bath composition and electrolysis conditions shown in Table 1 were used.
After forming the Ni-Mo-Co layer, washing and drying were performed in the same manner as in Example 1. Using the obtained copper foil as a test piece, a metal content measurement and a property test were performed in the same manner as in Example 1, and the results are shown in Table 1.

Example 5 Using the same copper foil as in Example 1, the surface was roughened in the same manner as in Example 1, and the plating bath composition and electrolysis conditions shown in Table 1 were used.
After forming a Ni-Mo-Co layer and washing with water, a chromate treated layer was formed and washed with water in the same manner as in Example 1. Thereafter, the same operation as in Example 1 was performed, except that a 0.08% (by weight) aqueous solution of 3-mercaptopropyltrimethoxysilane was used to form a silane coupling agent-treated layer. Using the obtained copper foil as a test piece, a metal content measurement and a property test were performed in the same manner as in Example 1, and the results are shown in Table 1.

Example 6 Using the same copper foil as in Example 1, the surface was roughened in the same manner as in Example 1, and the plating bath composition and the electrolysis conditions shown in Table 1 were used.
After forming a Ni-Mo-Co layer and washing with water, a chromate-treated layer was formed and washed with water in the same manner as in Example 1. Thereafter, the same operation as in Example 1 was performed except that 0.3% (by weight) of N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane was used to form a silane coupling agent-treated layer. Was done. Example 1 Using the obtained copper foil as a test piece,
The metal content measurement and the property test were performed in the same manner as in Example 1 and the results are shown in Table 1.

Example 7 Using the same copper foil as in Example 1, the surface was roughened in the same manner as in Example 1, and the plating bath composition and electrolysis conditions shown in Table 1 were used.
After forming a Ni-Mo-Co layer and washing with water, a chromate-treated layer was formed and washed with water in the same manner as in Example 1. Thereafter, the same as in Example 1 except that a 0.5% (by weight) aqueous solution of N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane was used to form a silane coupling agent treated layer. The operation was performed. Using the obtained copper foil as a test piece, a metal content measurement and a property test were performed in the same manner as in Example 1,
The results are shown in Table 1.

Example 8 Using the same copper foil as in Example 1, the surface was roughened in the same manner as in Example 1, and the plating bath composition and electrolysis conditions shown in Table 1 were used.
After forming a Ni-Mo-Co layer and washing with water, a chromate-treated layer was formed in the same manner as in Example 1, washed with water and dried. Using the obtained copper foil as a test piece, a metal content measurement and a property test were performed in the same manner as in Example 1, and the results are shown in Table 1.

Example 9 Using the same copper foil as in Example 1, the surface was roughened in the same manner as in Example 1, and the plating bath composition and the electrolysis conditions shown in Table 1 were used.
After forming the Ni-Mo-Co layer, washing and drying were performed in the same manner as in Example 1. Using the obtained copper foil as a test piece, a metal content measurement and a property test were performed in the same manner as in Example 1, and the results are shown in Table 1.

Example 10 Using the same copper foil as in Example 1, the surface was roughened in the same manner as in Example 1, and the plating bath composition and the electrolysis conditions shown in Table 1 were used.
After forming a Ni-Mo-Co layer and washing with water, a chromate-treated layer was formed and washed with water in the same manner as in Example 1. Thereafter, the same operation as in Example 1 was performed except that a 0.15% (by weight) aqueous solution of 3-glycidoxypropyltrimethoxysilane was used to form a silane coupling agent-treated layer. Using the obtained copper foil as a test piece, a metal content measurement and a property test were performed in the same manner as in Example 1, and the results are shown in Table 1.

Example 11 Using the same copper foil as in Example 1, the surface was roughened in the same manner as in Example 1, and the plating bath composition and electrolysis conditions shown in Table 1 were used.
After forming a Ni-Mo-Co layer and washing with water, a chromate-treated layer was formed and washed with water in the same manner as in Example 1. Thereafter, the same operation as in Example 1 was performed except that a 0.1% (by weight) aqueous solution of 3-aminopropyltriethoxysilane was used to form a silane coupling agent-treated layer. Using the obtained copper foil as a test piece, a metal content measurement and a property test were performed in the same manner as in Example 1, and the results are shown in Table 1.

Example 12 Using the same copper foil as in Example 1, the surface was roughened in the same manner as in Example 1, and the plating bath composition and the electrolysis conditions shown in Table 1 were used.
After forming a Ni-Mo-Co layer and washing with water, a chromate-treated layer was formed and washed with water in the same manner as in Example 1. After that, the same operation as in Example 1 was performed except that a 0.3% (by weight) aqueous solution of 3-glycidoxypropyltrimethoxysilane was used to form a silane coupling agent-treated layer. Using the obtained copper foil as a test piece, a metal content measurement and a property test were performed in the same manner as in Example 1, and the results are shown in Table 1.

Comparative Example 1 Using the same copper foil as in Example 1, the surface was roughened in the same manner as in Example 1, and the copper foil rough surface was subjected to a plating bath composition sodium cyanide 50 g / l sodium hydroxide 60 g / l cyan Copper oxide 90 g / l Zinc cyanide 5 g / l Electrolysis conditions Current density 5 A / dm ² pH 12 Temperature 80 ° C. Electrolysis time 10 seconds Perform cathodic electrolysis with copper / zinc alloy layer (alloy ratio about 70
After forming zinc 30) and washing with water, a chromate-treated layer was formed in the same manner as in Example 1, washed with water, and dried. Using the obtained copper foil as a test piece, a metal content (only zinc) and property test were carried out in the same manner as in Example 1, and the results are shown in Table 2.

Comparative Example 2 Using the same copper foil as in Example 1, the surface was roughened in the same manner as in Example 1, and the copper foil rough surface was subjected to plating bath composition sodium cyanide 50 g / l sodium hydroxide 60 g / l cyan Copper oxide 90 g / l Zinc cyanide 5 g / l Electrolysis conditions Current density 5 A / dm ² pH 12 Temperature 80 ° C. Electrodeposition time 10 seconds Cathodic electrolysis is carried out to form a copper / zinc alloy layer, which is washed with water. Similarly, a chromate treatment layer and a silane coupling agent treatment layer were sequentially formed and dried. Using the obtained copper foil as a test piece, a metal content (only zinc) and property test were carried out in the same manner as in Example 1, and the results are shown in Table 2.

[0076] Comparative Example 3 Example 1 carried out in the same manner as in the surface roughened as in Example 1 using the same copper foil with the composition plating bath Dohakuara surface _{NiSO 4 · 6H 2 O 50g /} l Na 2 MoO 4 · 2H subjected to cathode electrolysis at _{2 O 5g / l Na 3 C} 6 H 5 O 7 · 2H 2 O 30g / l electrolysis conditions pH 5.0 temperature 30 ° C. current density 2.0A / dm ² electrolysis time of 4 seconds, nickel Forming a molybdenum layer,
After washing with water, a chromate-treated layer was formed in the same manner as in Example 1, washed with water and dried. Using the obtained copper foil as a test piece, a metal content and property test was performed in the same manner as in Example 1, and the results are shown in Table 2.

[0077] Comparative Example 4 Example 1 carried out in the same manner as in the surface roughened as in Example 1 using the same copper foil as a plating bath composition Dohakuara surface _{NiSO 4 · 6H 2 O 50g /} l Na 2 MoO 4 · subjected to cathodic electrolysis in _{2H 2 O 7g / l Na 3} C 6 H 5 O 7 · 2H 2 O 30g / l electrolysis conditions pH 5.0 temperature 30 ° C. current density 2.0A / dm ² electrolysis time 4 seconds, After a nickel-molybdenum layer was formed and washed with water, a chromate treatment layer and a silane coupling agent treatment layer were sequentially formed and dried in the same manner as in Example 1. Using the obtained copper foil as a test piece, metal content and property tests were carried out in the same manner as in Example 1, and the results are shown in Table 2.

Comparative Example 5 Using the same copper foil as in Example 1, the surface was roughened in the same manner as in Example 1, and the copper foil rough surface was subjected to a plating bath composition of NiSO ₄ .6H ₂ O 60 g / l Na ₂ MoO _4. · 2H ₂ O 10g / l copper subjected to cathodic electrolysis in _{Na 3 C 6 H 5 O 7} · 2H 2 O 30g / l electrolysis conditions pH 5.0 temperature 30 ° C. current density 2.0A / dm ² electrolysis time 8 seconds -After forming a zinc alloy layer and washing with water, a chromate treatment layer and a silane coupling agent treatment layer were sequentially formed and dried in the same manner as in Example 1. Using the obtained copper foil as a test piece, metal content and property tests were carried out in the same manner as in Example 1, and the results are shown in Table 2.

[0079] carried out in the same manner as in the surface roughened as in Example 1 using the same copper foil as in Comparative Example 6 Example 1, the composition plating bath Dohakuara surface _{CoSO 4 · 7H 2 O 30g /} l Na 2 MoO 4 _{· 2H 2 O 1g / l Na} 3 C 6 H 5 O 7 · 2H 2 subjected to cathodic electrolysis in O 30 g / l electrolysis conditions pH 5 temperature 30 ° C. a current density of 2A / dm ² electrolysis time of 4 seconds, cobalt - molybdenum layer Forming
After washing with water, a chromate-treated layer was formed in the same manner as in Example 1, washed with water and dried. Using the obtained copper foil as a test piece, metal content and property tests were carried out in the same manner as in Example 1, and the results are shown in Table 2.

[0080] carried out in the same manner as in the surface roughened as in Example 1 using the same copper foil as in Comparative Example 7 Example 1, the composition plating bath Dohakuara surface _{CoSO 4 · 7H 2 O 40g /} l Na 2 MoO 4 _{· 2H 2 O 3g / l Na} 3 C 6 H 5 O 7 · 2H 2 subjected to cathodic electrolysis in O 30 g / l electrolysis conditions pH 5 temperature 30 ° C. a current density of 2A / dm ² electrolysis time 6 seconds, cobalt - molybdenum layer Forming
After washing with water, a chromate treatment layer and a silane coupling agent treatment layer were sequentially formed and dried in the same manner as in Example 1. Using the obtained copper foil as a test piece, metal content and property tests were carried out in the same manner as in Example 1, and the results are shown in Table 2.

[0081] carried out in the same manner as in the surface roughened as in Example 1 using the same copper foil as in Comparative Example 8 Example 1, the composition plating bath Dohakuara surface _{CoSO 4 · 7H 2 O 7g /} l Na 2 MoO 4 · 2H ₂ subjected to cathode electrolysis at _{O 10g / l Na 3 C 6} H 5 O 7 · 2H 2 O 30g / l electrolysis conditions pH 5 temperature 30 ° C. a current density of 2A / dm ² electrolysis time 8 seconds, cobalt - molybdenum layer Forming
After washing with water, a chromate treatment layer and a silane coupling agent treatment layer were sequentially formed and dried in the same manner as in Example 1. Using the obtained copper foil as a test piece, metal content and property tests were carried out in the same manner as in Example 1, and the results are shown in Table 2.

Comparative Example 9 Using the same copper foil as in Example 1, the same surface roughness as in Example 1 was used.
And then sodium bichromate (Na_TwoC r_TwoO₇・ 2H
_TwoO) 3.5 g / l aqueous solution was used as a plating bath, pH 5.7,
Liquid temperature 26 ° C, current density 0.5A / dm^Two, Electrolysis time 5 seconds
Cathodic electrolysis under the conditions described above, chromate treatment on the rough surface of copper foil
After forming a layer, washing and drying were performed. The obtained copper foil
Test for metal content and properties in the same manner as in Example 1 as a test piece
And the results are shown in Table 2.

Comparative Example 10 Using the same copper foil as in Example 1, the same surface roughness as in Example 1 was used.
The copper foil roughened surface was then subjected to sodium bichromate (Na_Two
C r_TwoO₇・ 2H_TwoO) 3.5 g / l aqueous solution is used as plating bath, pH
5.7, liquid temperature 26 ° C, current density 0.5A / dm^Two,electrolytic
Perform cathodic electrolysis under the condition of 5 seconds,
A heat treatment layer was formed. After washing with water,
Doxypropyltrimethoxysilane 0.15% (weight)
Apply the aqueous solution at a liquid temperature of 25 ° C with a shower and dry immediately.
Dry at 100 ° C for 5 minutes and chromate on the copper foil surface
Foil with a treated layer and a silane coupling agent treated layer
Was manufactured. This copper foil was used as a test piece in the same manner as in Example 1.
A metal content and property test was performed and the results are shown in Table 2.
did.

[0084]

[Table 1]

[0085]

[Table 2] A: Adhesive strength after lamination B: Degradation rate after immersion in hydrochloric acid C: Degradation rate after immersion in potassium cyanide D: Degradation rate after heat treatment E: Deterioration rate after boiling treatment F: Migration resistance G: Copper foil removed surface Example of copper foil having only a Ni-Mo-Co layer formed on a copper foil surface (Examples 2, 4, and 9), and examples of copper foil having a chromate-treated layer formed thereon (Examples 3 and 8) ) And examples of copper foils further formed with a silane coupling agent treatment layer on the chromate treatment layer (Examples 1, 5, 6, 7, 10, 11, and 12) are representative examples of the present invention. is there. Of these, Examples 2, 4, and 9
As compared with the other examples, although the adhesive strength in the normal state is slightly reduced, the practical level is maintained. Furthermore,
As in the other examples, the rate of deterioration of the adhesive strength after immersion in hydrochloric acid or an aqueous solution of potassium cyanide is suppressed to a small value. In addition, it is found that migration resistance, which is one of the electrical characteristics, is also excellent, and a decrease in insulating property caused by the migration phenomenon of copper ions can be prevented for a long time. Because of these excellent characteristics, the copper foil for printed circuits of the present invention can withstand use in a poor environment of high temperature and high humidity and maintain good quality reliability. It is considered that these metal properties of nickel, molybdenum and cobalt or alloy properties brought about by their synergistic action are involved in the improvement of these properties. It is considered that the effect is further enhanced.

On the other hand, in Comparative Examples 1 to 8 of the copper foil from the prior art for forming the binary alloy layer, it is shown that it is difficult to simultaneously satisfy the required characteristics of different qualities. . That is, Comparative Example 1 shows that the deterioration rate after boiling was large and hindered practical use.
Low migration resistance. In Comparative Examples 3, 4, and 5,
Deterioration rate after immersion in potassium cyanide aqueous solution is large, copper foil removal surface after etching has difficulty in heating discoloration,
There is also a need to improve the migration resistance depending on the amount of the components. Comparative Examples 6, 7, and 8 have a large deterioration rate after immersion in a potassium cyanide aqueous solution, and require much improvement in migration resistance. The ternary alloy coating layer composed of the Ni—Mo—Co layer of the present invention has a relatively small thickness (μg / dm ² ) (Example 11).
It can be seen that even in Comparative Examples 1 to 8, effects such as adhesive strength and migration resistance are enhanced. On the other hand, Comparative Examples 9 and 10 are examples in which neither the Ni-Mo-Co layer nor the conventional alloy layer was formed.
It can be seen that the migration resistance and the heat discoloration of the copper foil-removed surface are significantly inferior to those of the copper foil for printed circuits of the present invention.

[0087]

As described in detail above, the copper foil for printed circuits of the present invention has a ternary alloy coating layer composed of nickel, molybdenum and cobalt on the surface of the copper foil. When laminated with a resin base material to make a copper-clad laminate, it maintains good adhesion strength between the copper foil and the resin base material under severe conditions such as heat and chemicals as well as during lamination, and is practical Above is very useful. In addition, the copper foil for printed circuits of the present invention is excellent in migration resistance and greatly contributes to improvement of the insulation properties of printed circuits.

Further, by further forming a chromate-treated layer, or a chromate-treated layer and a silane coupling agent-treated layer on the ternary alloy coating layer, it is possible to obtain more excellent heat resistance and chemical resistance. Can be

Accordingly, in recent years, more and more layers,
For printed wiring boards with remarkable fineness, the copper foil of the present invention sufficiently satisfies the properties required for printed circuit copper foil such as heat resistance, chemical resistance, migration resistance, etc. It can be suitably used as a copper foil for an inner layer and an outer layer of a plate.

In the method for producing a copper foil of the present invention, the basic production conditions such as bath composition and electrolysis conditions can be selected from a wide range, and have an advantage that it is extremely easy to manage. It is excellent in mass productivity on an industrial scale and its value is great.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a test apparatus used for examining migration resistance.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Copper foil test piece 2 Iron plate 3 Glass plate 4 Distilled water

Claims (6)

(57) [Claims] 1. A printed circuit copper foil having a ternary alloy coating layer composed of nickel, molybdenum and cobalt on the surface of the copper foil. 2. A printed circuit copper foil having a ternary alloy coating layer composed of nickel, molybdenum and cobalt on the surface of the copper foil and a chromate treatment layer on the coating layer. 3. A printed circuit having a ternary alloy coating layer composed of nickel, molybdenum and cobalt on the surface of a copper foil, a chromate treatment layer on the coating layer, and a silane coupling agent treatment layer on the chromate treatment layer. Copper foil. 4. A ternary alloy coating layer comprising nickel, molybdenum and cobalt is formed by immersing a copper foil in a plating bath in which nickel ions, molybdate ions and cobalt ions coexist and subjecting the copper foil to a cathode treatment. Of producing printed circuit copper foil. 5. A ternary alloy coating layer composed of nickel, molybdenum and cobalt is formed by immersing a copper foil in a plating bath in which nickel ions, molybdate ions and cobalt ions coexist, and performing a cathode treatment on the copper foil surface. And then
A method for producing a copper foil for a printed circuit, wherein a cathode treatment is performed in an aqueous solution containing hexavalent chromium ions to form a chromate treatment layer on the coating layer. 6. A copper foil is immersed in a plating bath in which nickel ions, molybdate ions and cobalt ions coexist and subjected to a cathode treatment to form a ternary alloy coating layer composed of nickel, molybdenum and cobalt on the copper foil surface. And then
Cathode treatment is performed in an aqueous solution containing hexavalent chromium ions to form a chromate treatment layer on the coating layer, and then an aqueous solution of a silane coupling agent is further applied on the chromate treatment layer to form a silane coupling agent treatment layer. A method for producing a copper foil for a printed circuit, which forms