JPH08236930A - Copper foil for printed circuit and its manufacture - Google Patents

Abstract

PURPOSE: To obtain a sufficiently high bonding strength between copper foil and resin substrate so as to prevent the scattering of powder at the time of etching by providing a roughened layer containing specific kinds of metals on the surface of the copper foil to be bonded. CONSTITUTION: In order to reinforce the projecting sections of raw foil 1, a roughened layer 3 composed of numerous electrodeposited copper projections containing both one or two kinds of first-group metals selected out of a first- group composed of chromium and tungsten and one or two or more kinds of second-group metals selected out of a second group composed of vanadium, nickel, iron, cobalt, zinc, germanium, and molybdenum is formed on the surface of the foil 1 through roughening treatment. Thereafter, a thin plated-copper layer 4 is formed for preventing the falling off of the copper projections and a treated plated layer 5 is formed so as to give a heat resistance and other characteristics to the layer 4. Finally, a corrosion preventing layer 6 is formed. The surface to be bonded of the copper foil thus treated is bonded to a resin substrate, etc.

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 manufacturing the same, and in particular, chromium and tungsten are provided on the adhered surface of the copper foil in order to enhance the adhesive strength between the copper foil and the resin substrate. Group 1 metal which is one or two selected from the first group consisting of vanadium, nickel, iron,
A large number of protrusions (granular or nodular, hereinafter simply referred to as protrusions) containing both of one or more second group metals selected from the second group consisting of cobalt, zinc, germanium and molybdenum. The present invention relates to a copper foil for a printed circuit on which a roughening treatment layer made of a copper electrodeposit is formed and a method for producing the same.

[0002]

2. Description of the Related Art Generally, a printed circuit copper foil is laminated and adhered to a base material such as a synthetic resin under high temperature and high pressure, and then a predetermined circuit pattern is screen-printed with a resist to form a target circuit. An etching process is performed using an etching solution such as a cupric chloride solution to remove unnecessary portions. Finally, the required elements are soldered to form various printed circuit boards for electronic devices. Quality requirements for copper foils for printed wiring boards differ between the adhered surface (roughened surface) to be adhered to the resin base material and the glossy surface.

The requirements for the roughened surface to which the present invention relates are mainly that the peeling strength from the base material is sufficient even after high temperature heating, wet treatment, soldering, chemical treatment, etc. (peeling strength), There is no oxidative discoloration during storage (anti-rust property), lamination with a base material, no so-called laminated stain that occurs after etching (hydrochloric acid resistance), and no powder drop during etching (prevention of powder drop). Above all, having a sufficiently high peeling strength is the most important basic matter of the surface to be adhered.

In order to increase the adhesive strength between the copper foil and the resin substrate, a roughening treatment layer composed of a large number of protruding copper electrodeposits is formed on the adhered surface of the copper foil. When the electrolytic copper foil is subjected to a roughening treatment, the green foil itself already has a convex portion, and a large number of protruding copper electrodeposits are electrodeposited near the top of the convex portion to form a convex portion. It will be further enhanced.

As an effective roughening treatment, Japanese Patent Publication No. 54-38
No. 053, Japanese Examined Patent Publication No. 53-39327 and the like describe electrolyzing in an acidic copper electrolytic bath containing arsenic, antimony, bismuth, selenium or tellurium around a limiting current density. Practically, arsenic acid is often added to the electrolytic bath. As a result, a large number of protruding copper electrodeposits are formed on the convex portions of the raw foil, which increases the adhesive strength and is effective as a roughening treatment method.

[0006]

However, when arsenic is involved, arsenic is contained in the copper electrodeposit at several hundreds of p during electrolysis.
Since pm is taken in, the arsenic present during the recycling of the copper foil or other processing and the disposal of the etching solution in which arsenic is eluted during etching becomes a serious environmental and health problem.
As a roughening treatment method that does not include such toxic elements, a method using a bath to which a small amount of benzoquinoline is added is used (Japanese Patent Publication Sho 56).
No. 41196), molybdenum, vanadium, or a bath containing both of them (Japanese Patent Publication No. 62-56677 and Japanese Patent Publication No. 62-56678), or roughening treatment by pulse plating (Japanese Patent Laid-Open No. 63-17597). JP-A-58-16
No. 4797) has been proposed, but it is not always sufficient in terms of peeling strength, powder falling and the like.

An object of the present invention is to roughen the adhered surface of a copper foil for a printed circuit without causing environmental problems, yet exhibiting sufficient adhesive strength with a resin substrate and causing no powder drop during etching. It is to establish processing technology.

[0008]

Means for Solving the Problems As a result of studies aimed at solving the problems, the present inventors have found that (a) one or two selected from the first group consisting of chromium and tungsten.
Group metals and (b) vanadium, nickel, iron, cobalt,
Using a copper electrolytic bath containing both one or more second group metals selected from the second group consisting of zinc, germanium and molybdenum, a large number of projecting copper particles are formed on the adhered surface of the copper foil. When a roughening treatment layer made of an electrodeposit is formed, the generation of dendrites (dendritic crystals) is suppressed and the rounded projections are well electrodeposited, and the adhesive strength between the copper foil and the resin substrate is improved, and It came to be found to be useful in avoiding powder drop. Based on this finding, the present invention provides that, on the adhered surface of a copper foil, (a) one or two first group metals selected from the first group consisting of chromium and tungsten, and (b) vanadium, Nickel, iron, cobalt, zinc,
It is characterized by having a roughening treatment layer composed of a large number of protruding copper electrodeposits containing both one type or two or more types of second group metals selected from the second group consisting of germanium and molybdenum. Provided is a copper foil for a printed circuit.

A treat layer and a rust preventive layer can be further formed on the roughening treatment layer in the conventional manner. From this viewpoint,
The present invention further includes (a) a first group metal which is one or two selected from the first group consisting of chromium and tungsten, and (b) vanadium, nickel, iron, and
A roughening treatment layer comprising a large number of protruding copper electrodeposits containing both one or two or more second group metals selected from the second group consisting of cobalt, zinc, germanium and molybdenum; Treat layer for coating the roughening layer, which is made of one or more metals or alloys selected from the group consisting of copper, chromium, nickel, iron, cobalt and zinc, and rust preventive for coating the treat layer There is provided a copper foil for a printed circuit, which has a layer. It is beneficial to form a thin copper plating layer between the roughened layer and the treat layer to prevent the protruding copper electrodeposits from falling off.

Further, as a method for producing a copper foil for a printed circuit, the present invention uses a copper foil as a cathode in an acidic copper electrolytic bath to electrolyze in the vicinity of a limiting current density to produce a large number of protruding copper on the adhered surface of the copper foil. A copper foil for a printed circuit for forming a roughening treatment layer composed of an electrodeposit and a method for producing the same, wherein the electrolytic bath contains (a) one or two selected from the first group consisting of chromium and tungsten. Group metal: 0.0001 to 5 g / l
And (b) one or more second group metals selected from the second group consisting of vanadium, nickel, iron, cobalt, zinc, germanium, and molybdenum: 0.0
Provided is a method for producing a copper foil for a printed circuit, characterized in that both 01 to 50 g / l are present. Furthermore, on the roughening treatment layer, preferably, after forming a thin copper plating layer by electrolysis to prevent the dropout of the protruding copper electrodeposit on the roughening treatment layer formed, copper, chromium, nickel, iron, cobalt A method for producing a copper foil for a printed circuit as described above, characterized in that a treat layer made of one or more kinds of metals or alloys selected from the group consisting of zinc and zinc is formed by electrolysis and further subjected to rust prevention treatment. Provided.

[0011]

According to the present invention, in the electrolytic bath, (a) one or two selected from the first group consisting of chromium and tungsten.
Group 1 metal as a seed: 0.0001 to 5 g / l,
(B) One or two or more second group metals selected from the second group consisting of vanadium, nickel, iron, cobalt, zinc, germanium and molybdenum: 0.001 to 1
By forming the roughening treatment layer in the presence of both of 50 g / l, the protruding copper electrodeposit has a very small amount of the first group metal and the second group metal.
It will have a group metal together. The presence of the first group metal component of chromium and / or tungsten suppresses the generation of nuclei during electrodeposition of copper, suppresses the formation of dendrites, and rounds the electrodeposited projection particles to improve the adhesive strength. It is useful and prevents powder from falling off during etching. In the absence of chromium or tungsten ions in the electrolytic bath, electrolysis near the limiting current causes the copper electrodeposits to become dendritic and impair rather than improve the bond strength. When powder is removed, fine copper powder remains after the etching process, which may impair the electrical characteristics. Also, vanadium, nickel,
The presence of one or more second group metal components selected from iron, cobalt, zinc, germanium, and molybdenum promotes anisotropic growth of roughened particles and contributes to improvement of adhesive strength.

[0012]

DETAILED DESCRIPTION OF THE INVENTION The present invention can be applied to both rolled copper foil and electrolytic copper foil, but in particular to electrolytic copper foil. It is useful for further strengthening individually the large number of protrusions inherent in the electrolytic copper foil. Such a roughening treatment layer is effectively formed by electrolysis before and after the limiting current using a copper electrolytic bath containing a toxic element typified by arsenic as in the past. It presents environmental and health problems due to its inclusion.

FIG. 1 schematically shows an example of a treatment layer on the surface to be adhered of an electrolytic copper foil. Since the surface of the raw foil 1 to be adhered is an electrolytic copper foil, the convex portions 2 are distributed over the entire surface thereof. A roughening process is performed on this raw foil. By the roughening treatment according to the present invention, the first group metal which is one or two kinds selected from the first group consisting of (a) chromium and tungsten, and (b) vanadium, mainly in the vicinity of the top of the convex portion 2, One or two selected from the second group consisting of nickel, iron, cobalt, zinc, germanium and molybdenum
The roughening treatment layer 3 composed of a large number of protruding copper electrodeposits simultaneously containing the second group metal of at least one kind is formed, and the convex portions are strengthened. When a smooth copper foil such as a rolled copper foil is subjected to a roughening treatment, the electrodeposit itself constitutes a protrusion. After this, although there are many treatment modes, for example, a thin copper plating layer 4 is formed to prevent the protruding copper electrodeposits from falling off,
And chromium to give post heat resistance and other properties,
A metal or alloy such as nickel, iron, cobalt, and zinc, for example, a treat plating layer 5 such as brass is formed, and finally, a rust preventive layer 6 typified by chromate treatment is formed. The copper foil adhered surface thus treated is adhered to a resin substrate or the like. Hereinafter, each step will be described in detail.

The plating conditions of the roughening treatment copper electrolytic bath according to the present invention are as follows: (Roughening treatment copper electrolytic bath plating condition) Cu ion: 5 to 50 g / l H ₂ SO ₄ : 10 to 100 g / L Group 1 metal (one or two of Cr and W) ions: 0.0
001 to 5 g / l Group 2 metals (V, Ni, Fe, Co, Zn, Ge, Mo
Ion: 0.001 to 50 g / l Temperature: Room temperature to 50 ° C. D _k : 5 to 80 A / dm ² hours: 1 to 30 seconds

The concentration of chromium or tungsten or the combination of both present in the copper electrolytic bath is 0.0001.
~ 5 g / l is suitable, preferably 0.0002 to 1
g / l. If the amount added is less than 0.0001 g / l, the effect is not sufficient to increase the adhesive strength, while if it exceeds 5 g / l, the effect is not significantly improved and the economic burden increases. As a source of chromium or tungsten, it is possible to use sodium salts, potassium salts, oxides and the like. For example, chromic anhydride (VI), sodium tungstate (dihydrate) or the like is used. Further, the concentration of one kind or a combination of two or more kinds selected from vanadium, nickel, iron, cobalt, zinc, germanium and molybdenum to be present in the copper electrolytic bath is 0.001 to 50 g /
1 is suitable, and preferably 0.01 to 20 g / l. If the amount added is less than 0.001 g / l, there is no sufficient effect to promote anisotropic growth of roughened particles in order to increase the adhesive strength, while if it exceeds 50 g / l, there is no significant improvement in that effect. Rather, uneven treatment on the surface becomes noticeable. As a supply source of nickel, iron, cobalt, and zinc, their sulfates, oxides, hydroxides, etc. can be used. Also,
Sources of vanadium include oxides, vanadyl sulfate,
Oxygen acid salts such as sodium salt, potassium salt and ammonium salt can be used. As the source of germanium and molybdenum, sodium salts, potassium salts, ammonium salts of oxides or oxygenates can be used.

After the roughening treatment as described above, it is preferable that a known treatment, for example, a thin copper plating layer is formed as necessary to prevent the protruding electrodeposits from falling off. The most common copper electrolysis conditions when a copper sulfate bath is used as the coating of this thin copper layer are as follows. (Thin copper-plated layer electrolysis conditions) Cu _{ion: 5~50g / l H 2 SO 4} : 10~100g / l Temperature: room temperature _{~50 ℃ D k: 5~80A / dm} 2 Time: 1-30 seconds

The roughened surface is preferably subjected to the above thin copper plating, and then one or more metal layers or alloy layers selected from the group consisting of copper, chromium, nickel, iron, cobalt and zinc. Is preferably performed. For example, a metal layer of copper, chromium, nickel, iron, cobalt, or zinc, or an alloy layer represented by copper-nickel, copper-cobalt, copper-nickel-cobalt, copper-zinc, or the like can be formed (for example, a special Kosho 56-902
No. 8, JP-A-54-13971, JP-A-2-2928.
94, JP-A-2-292895, JP-B-51-35.
711, Japanese Patent Publication No. 54-6701). Such treated layers serve as determinants of the final properties of the copper foil and as barrier layers.

Taking the zinc coating as an example, either zinc electroplating or electroless plating can be performed, but zinc electrolytic operation is more convenient for forming the coating only on one surface of the roughened surface. Further, the electrolysis operation is preferable from the viewpoints of precise control of thickness, thickness uniformity, densification of the adhesion layer, and the like. The zinc electrolysis operation can be performed using an acidic zinc plating bath typified by a zinc sulfate plating bath or a zinc chloride plating bath, an alkaline zinc plating bath such as a zinc cyanide plating bath, or a zinc pyrophosphate plating bath. A commonly used zinc sulfate bath is sufficient. The preferable zinc electrolysis conditions when using a zinc sulfate bath are as follows. (Zinc Treat process electrolysis _{conditions) ZnSO 4 · 7H 2 O:} 50~350g / l pH ( sulfate): 2.5-4.5 bath temperature: 40 to 60 ° C. Cathode: copper anode: zinc or insoluble anode Cathode current density: 0.05~0.4A / dm ² Time: 10-30 seconds zinc coating amount is preferably set to 15~1500μg / dm ^2, particularly preferably 15~400μg / dm ²
Is. The amount of zinc coating varies depending on the type of resin substrate at the time of stacking. For example, for phenol resin substrates, 15 to 60
μg / dm ² and 60 for glass epoxy resin substrate
˜1500 μg / dm ² , particularly preferably 60 to 400
μg / dm ² .

As an example of the alloy layer, an electrolytic solution composition and conditions of Cu-Zn treat treatment will be described: (Cu-Zn treat treatment electrolysis conditions) NaCN: 10 to 30 g / l NaOH: 40 to 100 g / l CuCN: _{60~120g / l Zn (CN) 2} : 1~10g / l pH: 10~13 _{temperature: 60~80 ℃ D k: 1~10A /} dm 2

Further, preferably, a rust preventive layer is formed on the surface of the treated layer. Any known rustproofing treatment can be applied. As the chromate treatment liquid, any of various treatment liquids currently used can be used, but preferable chromate treatment condition examples are as follows: (Chromate treatment condition Electrolytic condition) K ₂ Cr ₂ O ₇ (or Na ₂ Cr ₂ O) ₇ , CrO ₃ ):
0.2 to 20 g / l Acid: phosphoric acid or sulfuric acid, organic acid pH: 1.0 to 3.5 Bath temperature: 20 to 40 ° C. Current density: 0.1 to 0.5 A / dm ² hours: 10 to 60 Second Anode: Lead plate, Pt-Ti plate, stainless steel plate Chromium oxide adhesion amount is 50 μg / dm ² as chromium amount
The following is sufficient and preferably 15 to 30 μg / dm ^2.
It is said. When the amount of chromium exceeds 30 μg / dm ² , the rust preventive power is improved but the etching property is deteriorated.

As a useful rust preventive method, the present applicant has proposed electrolytic zinc-chromium mixed film treatment of zinc and / or zinc oxide and chromium oxide (Japanese Patent Publication No. 58-7).
No. 077), many achievements have been made. Furthermore, JP-A-2
No. 294490, for the purpose of preventing the generation of black spots under high temperature and high humidity conditions for a long period of time, a chromium oxide film is formed by immersion chromate treatment, and then zinc and / or zinc oxide is formed by electrolytic zinc / chromium treatment. Forming a mixed film with chromium oxide is disclosed.

Finally, if necessary, a silane treatment for applying a silane coupling agent onto the anticorrosion layer is performed mainly for the purpose of improving the adhesive force between the copper foil and the resin substrate. The coating method may be spraying of a silane coupling agent solution, coating with a coater, dipping, pouring, or the like. For example, Japanese Examined Patent Publication No. 60-15654 describes that the adhesion between the copper foil and the resin substrate is improved by subjecting the rough surface side of the copper foil to a chromate treatment and then a silane coupling agent treatment. . For details, refer to this.

The copper foil having the roughened surface thus coated is
After processing the glossy surface as necessary, apply an adhesive to the roughened surface and heat press bond to the resin substrate to make a copper clad laminate for printed circuits, and after a predetermined processing operation, as a printed circuit board Be used. As a treatment method for glossy surface, various chemical conversion treatments including chromate treatment, organic agent treatment utilizing chelation reaction with copper, coating treatment of metals or alloys that are baser than copper, etc. Appropriate one is selected.

Thereafter, if necessary, an annealing treatment may be performed for the purpose of improving the ductility of the copper foil.

The first group metal according to the present invention contains chromium or tungsten ions or a combination thereof, and the second group metal contains one or more ions selected from vanadium, nickel, iron, cobalt, zinc, germanium and molybdenum. The copper foil roughened in the copper electrolytic bath was uniformly treated and showed excellent substrate characteristics without unevenness. That is, when a laminate is prepared from a copper foil and a glass cloth-based epoxy resin, it shows good adhesiveness and heat resistance, and a rounded copper electrodeposit with suppressed dendrite development is formed. It was high and showed good properties without problems such as electrical characteristics of the substrate after etching and powder falling off.

[0026]

EXAMPLES Examples and comparative examples will be described below.

(Example 1) 100 g of copper sulfate (pentahydrate) /
1, sulfuric acid 100 g / l, chromic anhydride (VI) 1 g /
1, an aqueous solution containing 13 g / l of nickel sulfate hexahydrate and 14 g / l of cobalt sulfate heptahydrate was used as an electrolytic bath at 30 ° C., and a current density of 20 A was applied to an adhered surface of an electrolytic copper foil having a thickness of 70 μm. / Dm ² for 10 seconds to form a protruding copper electrodeposit, and then copper ion 45 g / l and sulfuric acid 100 g
30 A / dm using a copper electrolyte solution (40 ° C.) containing 1 / l
Copper plated at ² for 4 seconds. When the copper foil thus obtained was analyzed, the contents of chromium, nickel and cobalt with respect to the entire foil were as follows: chromium: about 1 ppm, nickel: about 2 ppm and cobalt: 0.5 ppm (in the protruding copper electrodeposit) The contents of Cr, Ni and Co are as follows: Cr: about 0.01 wt%, Ni: about 0.02 wt% and Co:
It was about 0.005 wt%). The copper foil thus obtained was heated and pressed against a glass cloth-based epoxy resin to prepare a copper-clad laminate, and the peel strength and powder falling characteristics were measured. The results are shown in Table 1. Further, the copper foil having a zinc treated layer and a rust preventive layer formed on the roughened layer exhibited better heat resistance and oxidation resistance.

Example 2 Copper sulfate (pentahydrate) 100 g /
1, sulfuric acid 100 g / l, sodium tungstate (2
Water salt) 0.02 g / l, nickel sulfate hexahydrate 13 g /
1 and 3 g of an aqueous solution containing 14 g of cobalt sulfate heptahydrate / l.
It is used as an electrolytic bath at 0 ° C., and the surface to be adhered of an electrolytic copper foil having a thickness of 70 μm is plated at a current density of 10 A / dm ² for 20 seconds to form a protruding copper electrodeposit, and then copper ions are added at 45 g / l,
Using an electrolytic solution (40 ° C.) containing 100 g / l of sulfuric acid, 30
Plated at A / dm ² for 4 seconds. When the copper foil thus obtained was analyzed, the content of tungsten, nickel and cobalt in the entire foil was about 1 pp each.
m, about 2 ppm and about 0.6 ppm (the content of W, Ni and Co in the protruding copper electrodeposition is about 0.01 respectively)
wt%, about 0.02 wt% and about 0.006 wt%)
Met. The copper foil thus obtained was heated and pressed against a glass cloth-based epoxy resin to prepare a copper-clad laminate, and the peel strength and powder falling characteristics were measured. The results are shown in Table 1. Furthermore,
The copper foil having a zinc treated layer and a rust preventive layer formed on the roughened layer showed better heat resistance and oxidation resistance.

Example 3 Copper sulfate (pentahydrate) 100 g /
1, sulfuric acid 100g / l, chromic anhydride (VI) 0.1g
/ L, sodium tungstate (dihydrate) 0.01g
/ L, 13 g / l of nickel sulfate hexahydrate, and 14 g / l of cobalt sulfate heptahydrate were used as an electrolytic bath at 30 ° C., and a current density was applied to the adhered surface of an electrolytic copper foil having a thickness of 70 μm. After plating with 20 A / dm ² for 10 seconds to form a protruding copper electrodeposit, copper ion 45 g / l, sulfuric acid 100 g
Using an electrolytic solution (40 ° C.) containing 1 / l, plating was performed at 30 A / dm ² for 4 seconds. When the copper foil thus obtained was analyzed, chromium and tungsten for the entire foil,
The content of nickel and cobalt is chromium: about 0.1p
pm, tungsten: about 0.7 ppm, nickel: about 2
ppm and cobalt: about 0.6 ppm (contents in the protruding copper electrodeposit are Cr: about 0.001 wt%, W: about 0.007 wt%, Ni: about 0.02 wt% and C
o: about 0.006 wt%). The copper foil thus obtained was heated and pressed against a glass cloth-based epoxy resin to prepare a copper-clad laminate, and the peel strength and powder falling characteristics were measured.
The results are shown in Table 1. Further, the copper foil having a zinc treated layer and a rust preventive layer formed on the roughened layer exhibited better heat resistance and oxidation resistance.

Example 4 Copper sulfate (pentahydrate) 100 g /
1, sulfuric acid 100 g / l, sodium tungstate (2
Water salt) 0.01 g / l, and cobalt sulfate heptahydrate 14
An aqueous solution containing g / l was used as an electrolytic bath at 30 ° C., and a current density of 20 A / d was applied to the adhered surface of an electrolytic copper foil having a thickness of 70 μm.
After plating with m ² for 10 seconds to form a protruding copper electrodeposit, it was plated with 30 A / dm ² for 4 seconds using an electrolytic solution (40 ° C.) containing 45 g / l of copper ions and 100 g / l of sulfuric acid. When the copper foil thus obtained was analyzed, the content of tungsten and cobalt in the entire foil was found to be about 0.7 ppm for tungsten and about 1 pp for cobalt.
m (content in the protruding copper electrodeposition is W: about 0.007w
t% and Co: about 0.01 wt%). The copper foil thus obtained was heated and pressed against a glass cloth-based epoxy resin to prepare a copper-clad laminate, and the peel strength and powder falling characteristics were measured. The results are shown in Table 1. Further, the copper foil having a zinc treated layer and a rust preventive layer formed on the roughened layer exhibited better heat resistance and oxidation resistance.

Comparative Example 1 As an example containing no additives,
An aqueous solution containing 100 g / l of copper sulfate (pentahydrate) and 100 g / l of sulfuric acid was used as an electrolytic bath at 30 ° C. and had a thickness of 70 μm.
1 with a current density of 20 A / dm ² on the surface to be adhered of electrolytic copper foil of m
After plating for 0 seconds, copper ion 45g / l, sulfuric acid 100
Using an electrolytic solution (40 ° C.) containing g / l, 30 A / dm ²
For 4 seconds. The copper foil thus obtained was heated and pressed against a glass cloth-based epoxy resin to prepare a copper-clad laminate, and the peel strength and powder falling characteristics were measured. The results are shown in Table 1.

Comparative Example 2 As an example containing conventional arsenic, copper sulfate (pentahydrate) 100 g / l, sulfuric acid 100 g / l
Then, an aqueous solution containing 3 g / l of arsenic acid was used as an electrolytic bath at 30 ° C., and the adhered surface of an electrolytic copper foil having a thickness of 70 μm was plated at a current density of 20 A / dm ² for 10 seconds, and then copper ions 45
Using an electrolytic solution (40 ° C.) containing g / l and 100 g / l of sulfuric acid, plating was performed at 30 A / dm ² for 4 seconds. When the copper foil thus obtained was analyzed, the content of arsenic in the entire foil was about 200 ppm (the content of As in the protruding copper electrodeposit was about 1.2 wt%). The copper foil thus obtained was heated and pressed against a glass cloth-based epoxy resin to prepare a copper-clad laminate, and the peel strength and powder falling characteristics were measured. The results are shown in Table 1.

[0033]

[Table 1]

[0034]

The first group metal component of chromium or tungsten or both according to the present invention and the second group metal of one or more selected from vanadium, nickel, iron, cobalt, zinc, germanium and molybdenum. The copper foil roughened in the copper electrolytic bath containing the components is uniformly treated and shows excellent substrate characteristics without unevenness. When a laminated board is made of copper foil and glass cloth base epoxy resin,
Since a rounded electrodeposit having good adhesiveness and heat resistance and suppressing the development of dendrites is formed, the adhesive strength is improved, and there is no problem of electrical characteristics of the substrate after etching or powder falling off.

[Brief description of drawings]

FIG. 1 is a cross-sectional view schematically showing an example of a treatment layer on a surface to be adhered of an electrolytic copper foil.

[Explanation of symbols]

 1 Raw foil 2 Convex part 3 Roughening treatment layer 4 Copper plating layer 5 Treat treatment plating layer 6 Rust preventive layer

Claims (6)

[Claims] 1. A first group metal, which is one or two selected from the first group consisting of chromium and tungsten, and (b) vanadium, nickel, iron,
To have a roughening treatment layer composed of a large number of protruding copper electrodeposits containing both of one or more second group metals selected from the second group consisting of cobalt, zinc, germanium and molybdenum. Copper foil for printed circuits characterized by. 2. A first group metal, which is one or two selected from the first group consisting of chromium and tungsten, and (b) vanadium, nickel, iron, and
A roughening treatment layer comprising a large number of protruding copper electrodeposits containing both one or two or more second group metals selected from the second group consisting of cobalt, zinc, germanium and molybdenum; Copper, chromium, which coats the roughened layer,
A printed circuit having a treat layer composed of one or more kinds of metals or alloys selected from the group consisting of nickel, iron, cobalt and zinc, and a rust preventive layer covering the treat layer. Copper foil. 3. The copper foil for a printed circuit according to claim 2, wherein a thin copper plating layer that prevents the protruding copper electrodeposits from falling off is formed between the roughening treatment layer and the treat layer. 4. A copper for printed circuit, wherein a copper foil is used as a cathode in an acidic copper electrolytic bath to electrolyze in the vicinity of a limiting current density to form a roughening treatment layer composed of a large number of protruding copper electrodeposits on the adhered surface of the copper foil. In the method for producing a foil, in the electrolytic bath, (a) one or two selected from the first group consisting of chromium and tungsten.
Group 1 metal as a seed: 0.0001 to 5 g / l,
(B) One or two or more second group metals selected from the second group consisting of vanadium, nickel, iron, cobalt, zinc, germanium and molybdenum: 0.001 to 5
A method for producing a copper foil for a printed circuit, characterized in that both 0 g / l are present. 5. Copper, chromium, on the roughening layer thus formed
5. The printed circuit according to claim 4, wherein a treat layer made of one or more kinds of metals or alloys selected from the group consisting of nickel, iron, cobalt and zinc is formed by electrolysis, and further treated for rust prevention. Method for manufacturing copper foil. 6. A thin copper plating layer for preventing drop-out of protruding copper electrodeposits from being electrolytically formed on the roughening treatment layer formed, and copper, chromium, nickel, and the like on the formed copper plating layer.
The copper for printed circuit according to claim 4, wherein a treat layer made of one or more kinds of metals or alloys selected from the group consisting of iron, cobalt and zinc is formed by electrolysis, and further treated for rust prevention. Method of manufacturing foil.