JP2920083B2 - Copper foil for printed circuit and manufacturing method thereof - 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 manufacturing the same. the first group and the metal is one or two species selected from a first group consisting of, nickel, iron, one or two species selected from cobalt and <br/> second group including zinc or al A copper foil for a printed circuit on which a roughened layer composed of a large number of projecting (granular or knotted, hereinafter simply referred to as projecting) copper electrodeposits containing both of the above second group metals and It relates to the manufacturing method.

[0002]

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

The requirements for the roughened surface to which the present invention is concerned mainly include that the peel strength with the substrate is sufficient even after high-temperature heating, wet processing, soldering, chemical processing, etc. (peel strength). There is no oxidative discoloration during storage (rust prevention), no lamination with a substrate, no so-called lamination stains generated after etching (hydrochloric acid resistance), no powder fall during etching (dust fall prevention), and the like. Above all, having a sufficiently high peel strength is the most important basic matter of the surface to be bonded.

[0004] In order to increase the adhesive strength between the copper foil and the resin substrate, a roughening layer made of a large number of projecting copper electrodeposits is formed on the surface to be bonded of the copper foil. When the roughening treatment is performed on the electrolytic copper foil, the raw foil itself has a convex portion, and a large number of projecting copper electrodeposits are electrodeposited near the top of the convex portion to form the convex portion. It will further increase.

An effective roughening treatment is disclosed in Japanese Patent Publication No. 54-38.
No. 053, JP-B-53-39327 and the like describe electrolysis at around a critical current density in an acidic copper electrolytic bath containing arsenic, antimony, bismuth, selenium or tellurium. Practically, arsenic acid is often added to the electrolytic bath. As a result, a large number of protruding copper electrodeposits are formed on the protruding portions of the raw foil, thereby increasing the adhesive strength, and is effective as a roughening treatment method.

[0006]

However, when arsenic is involved, several hundreds of arsenic is contained in the copper electrodeposit during electrolysis.
Since the arsenic is taken in by pm, arsenic present at the time of copper foil regeneration or other processing and at the time of disposal of an etchant from which arsenic has been eluted during etching poses a serious environmental and health problem.
As a roughening treatment method that does not contain such toxic elements, a method using a bath to which a small amount of benzoquinolines are added (Japanese Patent Publication No.
No. 41196), treatment with a bath containing molybdenum, vanadium or both (Japanese Patent Publication No. Sho 62-56677 and Japanese Patent Publication No. 62-56678), or roughening treatment by pulse plating (Japanese Patent Application Laid-Open No. 63-17597, JP-A-58-16
No. 4797) has been proposed, but the peel strength, powder dropout and other aspects are not always sufficient.

An object of the present invention is to provide a roughened surface which does not present an environmental problem on the surface to be bonded of a copper foil for a printed circuit, exhibits sufficient adhesive strength with a resin substrate, and does not cause powder to fall off during etching. Establish processing technology.

[0008]

As a result of the study for solving the problems, the present inventors have found that (a) one or two of the first group selected from the first group consisting of chromium and tungsten.
Group metal and (b) nickel, iron, second is cobalt and zinc or we made one upcoming selected from the second group, or two or more
When a roughened layer composed of a large number of projecting copper electrodeposits is formed on the surface to be bonded of a copper foil using a copper electrolytic bath containing both the group metals, the generation of dendrites (dendritic crystals) is suppressed. Then, it has been found that the rounded protrusions are well electrodeposited, which is useful for improving the adhesive strength between the copper foil and the resin substrate and for avoiding powder falling. Based on this finding,
The present invention, in the bonding surface of the copper foil, (a) chromium and the first metal group and is one or two species selected from a first group consisting of tungsten (b) nickel, iron, cobalt and nitrous lead
Printed circuit, characterized in that it comprises a roughened layer consisting of a number of protruding copper electrodeposits containing both with one or the second metal group is two or more species selected from a second group consisting pressurized et al Provide copper foil for

[0009] A treat layer and a rust-preventive layer can be further formed on the roughened layer in the conventional manner.
The present invention further relates to the bonding surface of the copper foil, (a) chromium and the first metal group and is one or two species selected from a first group consisting of tungsten (b) nickel, iron, cobalt, and a roughened layer consisting of a number of protruding copper electrodeposits containing both a second metal group <br/> is zinc or we made one upcoming selected from the second group, or two or more, the A treat layer comprising one or more metals or alloys selected from the group consisting of copper, chromium, nickel, iron, cobalt and zinc, which covers the roughening treatment layer, and rust prevention covering the treat layer A copper foil for a printed circuit, comprising: It is advantageous to form a thin copper plating layer between the roughened layer and the treat layer to prevent the protruding copper electrodeposit from falling off.

Further, as a method of manufacturing a copper foil for a printed circuit, the present invention relates to a method for producing a copper foil in an acidic copper electrolytic bath using a copper foil as a cathode near the critical current density to form a large number of projecting copper on the surface to be bonded of the copper foil. A copper foil for a printed circuit forming a roughened layer made of an electrodeposit and a method of manufacturing the same, wherein (a) a first or two kinds selected from the first group consisting of chromium and tungsten in an electrolytic bath. Group metal: 0.0001 to 5 g / l
If, (b) nickel, iron, cobalt and zinc or we made one upcoming selected from the second group or at two or more Group 2 metal: it made present both 0.001 to 50 g / l The present invention provides a method for producing a copper foil for a printed circuit characterized by the following. Further, on the roughened layer, preferably after forming a thin copper plating layer on the formed roughened layer by electrolysis to prevent the protruding copper electrodeposits from falling off, copper, chromium, nickel, iron, cobalt And a method of producing a copper foil for a printed circuit as described above, wherein a treat layer made of one or more 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, (a) one or two selected from the first group consisting of chromium and tungsten are contained in the electrolytic bath.
A first group metal as a seed: 0.0001 to 5 g / l;
(B) nickel, iron, cobalt and zinc or we made a second one upcoming selected from the group or at two or more second metal group:
By forming the roughened layer by allowing both of 0.001 to 50 g / l to be present, a small amount of the first electrodeposited copper is deposited.
It has both the group metal and the second group metal. The presence of the first group metal component of chromium and / or tungsten suppresses nucleation during copper electrodeposition and suppresses the formation of dendrites, and also improves the adhesion strength by rolling the electrodeposited projection particles. It is useful and prevents powder from falling off during etching. If chromium or tungsten ions are not present in the electrolytic bath, electrolysis near the limiting current will cause the copper electrodeposit to become dendritic and impair rather than improve the bond strength. If powder fall occurs, there is a risk that electrical characteristics may be impaired since fine copper powder remains after the etching treatment. Also, two Tsu Ke <br/> Le, iron, the presence of one or more of the second group metal component selected from cobalt and zinc or we made the second group, anisotropic growth of the roughening particles And contribute to the improvement of the adhesive strength.

[0012]

DETAILED DESCRIPTION OF THE INVENTION The present invention can be applied to both rolled copper foil and electrolytic copper foil, and particularly to electrolytic copper foil. It is useful to further enhance individual multiple bumps inherent in the electrolytic copper foil. Such a roughened layer is effectively formed by electrolysis before and after the limit current using a copper electrolytic bath containing a toxic element represented by arsenic as in the conventional case. They were exposed to environmental and health problems.

FIG. 1 schematically shows an example of a treatment layer on the surface to be bonded of an electrolytic copper foil. Since the surface to be bonded of the raw foil 1 is an electrolytic copper foil, the protrusions 2 are distributed over the entire surface. A roughening treatment is performed on the raw foil. The roughening treatment according to the present invention, the vicinity of the top portion of the convex portion 2 mainly (a) the first group metal and which is one or more of the compounds selected from the first group consisting of chromium and tungsten (b) two Tsu Ke <br/> Le, iron, is composed of a large number of protruding copper electrodeposits containing cobalt and one upcoming selected from zinc or we made the second group, or two or more at which the second metal group simultaneously Roughening layer 3
Are formed, and the convex portions are strengthened. When a roughening treatment is performed on a smooth copper foil such as a rolled copper foil, the electrodeposit itself forms a projection. After this, there are a number of treatment modes, for example, a thin copper plating layer 4 is formed to prevent the protruding copper electrodeposit from falling off, and chromium, nickel, iron is added to impart post heat resistance and other properties. Then, a treat plating layer 5 of a metal or an alloy such as cobalt and zinc, for example, brass or the like is formed, and finally a rust prevention layer 6 represented by chromate treatment or the like 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 copper electrolytic bath for roughening treatment according to the present invention are as follows: (Plating conditions for copper electrolytic bath for roughening treatment) Cu ions: 5 to 50 g / l H ₂ SO ₄ : 10 to 100 g / L First group metal (one or two of Cr and W) ions: 0.0
001~5g / l second metal group (N i, Fe, Co, 1 kind or two or more of Z n) ions: 0.001 to 50 g / l Temperature: room temperature ~50 ℃ D _k: 5~80A / dm ² hours: 1 to 30 seconds

The concentration of chromium or tungsten, or a combination of both, in the copper electrolytic bath is 0.0001.
To 5 g / l, preferably 0.0002 to 1 g / l.
g / l. If the added amount is less than 0.0001 g / l, there is no sufficient effect to increase the adhesive strength, while if it exceeds 5 g / l, the effect is not remarkably improved and the economic burden increases. As a source of chromium or tungsten, a sodium salt, a potassium salt, an oxide or the like can be used. For example, chromic anhydride (VI), sodium tungstate (dihydrate) and the like are used. Further, Runi be present in the electrolytic copper bath nickel, iron, cobalt, the concentration of one or more combinations selected zinc or colleagues, 0.001
５０50 g / l is suitable, preferably 0.01-20.
g / l. If the amount is less than 0.001 g / l, there is no sufficient effect to promote the anisotropic growth of the roughened particles to increase the adhesive strength, and if it exceeds 50 g / l, the effect is not significantly improved. Rather, the processing unevenness on the surface becomes conspicuous. As a source of nickel, iron, cobalt, and zinc, sulfates, oxides, hydroxides, and the like thereof can be used .

After the above-described roughening treatment, it is preferable that a known treatment is performed as necessary, for example, a thin copper plating layer is formed 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

After the roughened surface is preferably subjected to the above-described thin copper plating, 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 typified by copper-nickel, copper-cobalt, copper-nickel-cobalt, copper-zinc, etc. can be formed (for example, Kosho 56-902
8, JP-A-54-13971, JP-A-2-2928
No. 94, JP-A-2-292895, JP-B-51-35
711, JP-B-54-6701). Such a treated layer plays a role in determining the final properties of the copper foil and also as a barrier layer.

Taking a zinc coating as an example, both zinc electroplating and electroless plating can be performed. However, in order to form a coating on only one surface of the roughened surface, it is more convenient to use a zinc electrolytic operation. The electrolytic operation is also preferable from the viewpoint of precise control of the thickness, uniformity of the thickness, and densification of the adhesion layer. For the zinc electrolysis operation, an acidic zinc plating bath represented 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 can be used. A commonly used zinc sulfate bath is sufficient. Preferred 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
It is. The amount of zinc coating varies depending on the type of resin substrate at the time of lamination. For example, for a phenolic resin substrate, 15 to 60
μg / dm ² and 60 for glass epoxy resin substrates
１1500 μg / dm ² , particularly preferably 60-400
μg / dm ² .

As an example of the alloy layer, the composition and conditions of the electrolytic solution for Cu-Zn treatment are as follows: (Cu-Zn treatment electrolytic 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 rust prevention treatment can be applied. As the chromate treatment liquid, any of various treatment liquids currently used can be used. Preferred examples of the chromate treatment conditions are as follows: (Chromate treatment conditions and electrolytic conditions) 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 The amount of chromium oxide attached is 50 μg / dm ² as the amount of chromium.
The following is sufficient, and preferably 15 to 30 μg / dm ^2.
It is said. If the amount of chromium exceeds 30 μg / dm ² , the rust-preventing power is improved, but the etching property is lowered.

As a useful rust prevention method, the present applicant has proposed a mixed film treatment of zinc and / or zinc oxide and chromium oxide by electrolytic zinc / chromium treatment (Japanese Patent Publication No. 58-7).
No. 077), and many achievements have been made. Further, Japanese Patent Application Laid-Open
No. 294490 discloses a method of forming a chromium oxide film by immersion chromate treatment for the purpose of preventing the generation of black spots under a high-temperature and high-humidity condition for a long time, followed by electrolytic zinc / chromium treatment to form zinc and / or zinc oxide. A method for forming a mixed film with chromium oxide is disclosed.

Finally, if necessary, a silane treatment for applying a silane coupling agent on the rust-preventing layer is performed mainly for the purpose of improving the adhesion between the copper foil and the resin substrate. The application method may be any of spraying of a silane coupling agent solution, application with a coater, immersion, and pouring. For example, Japanese Patent Publication No. 60-15654 describes that the adhesive strength between a copper foil and a resin substrate is improved by performing a silane coupling agent treatment after performing a chromate treatment on a rough surface side of the copper foil. . Please refer to this for details.

The copper foil whose surface has been roughened in this way is
After processing the glossy surface as necessary, apply an adhesive to the roughened surface and heat and press it on the resin substrate to make a copper-clad laminate for printed circuits, and after a predetermined processing operation, as a printed circuit board Served for use. Depending on the specific level required for the surface, such as various chemical conversion treatments including chromate treatment, organic agent treatment using chelation reaction with copper, and coating treatment of metals or alloys lower than copper, etc. And an appropriate one is selected.

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

[0025] 1 this chromium or tungsten ions or a combination thereof as a first group metal by the invention and the second metal group <br/> and to nickel, iron, selected cobalt and zinc or al
The copper foil roughened with a copper electrolytic bath containing one or more kinds of ions was treated uniformly, and showed excellent substrate characteristics without unevenness. That is, when a laminate is made of a copper foil and a glass cloth base 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 of electrical characteristics and powder drop of the substrate after etching.

[0026]

EXAMPLES Examples and comparative examples will be described below.

Example 1 Copper sulfate (pentahydrate) 100 g / l, sulfuric acid 100 g / l, chromic anhydride (VI) 1 g / l, nickel sulfate hexahydrate 1
An aqueous solution containing 3 g / l and 14 g / l of cobalt sulfate heptahydrate was used as an electrolytic bath at 30 ° C., and the surface to be bonded of a 70 μm-thick electrolytic copper foil was plated at a current density of 20 A / dm ² for 10 seconds. After the formation of the protruding copper electrodeposit, the copper ions 4
Copper electrolyte containing 5 g / l and 100 g / l sulfuric acid (40
C) at 30 A / dm 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 were: Cr: about 0.01 wt%, Ni: about 0.02 wt%, and Co: about 0.005 wt%). The obtained copper foil was heated and pressed on a glass cloth base epoxy resin to prepare a copper-clad laminate, and the peeling strength and the powder falling property were measured. Table 1 shows the results. Furthermore, the copper foil in which the zinc-treated layer and the rust-preventive layer were formed on the roughened layer exhibited better heat resistance and oxidation resistance.

Example 2 Copper sulfate (pentahydrate) 100 g / l, sulfuric acid 100 g / l, sodium tungstate (dihydrate) 0.02 g / l, nickel sulfate hexahydrate 13 g / l, cobalt sulfate An aqueous solution containing 14 g / l of heptahydrate was used as an electrolytic bath at 30 ° C., and a current density of 10 μm was applied to the surface to be adhered of a 70 μm-thick electrolytic copper foil.
After forming a protruding copper electrodeposit by plating with A / dm ² for 20 seconds, plating was performed at 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 contents of tungsten, nickel and cobalt relative to the entire foil were about 1 ppm, about 2 ppm and about 0.6 ppm, respectively (W, Ni and Co in the protruding copper electrodeposit). Are about 0.01 wt% and about 0.02 wt%, respectively.
% And about 0.006 wt%). The obtained copper foil was heated and pressed on a glass cloth base epoxy resin to prepare a copper-clad laminate, and the peeling strength and the powder falling property were measured. Table 1 shows the results. Furthermore, the copper foil in which the zinc-treated layer and the rust-preventive layer were formed on the roughened layer exhibited better heat resistance and oxidation resistance.

(Example 3) Copper sulfate (pentahydrate) 100 g / l, sulfuric acid 100 g / l, chromic anhydride (VI) 0.1 g / l, sodium tungstate (dihydrate) 0.01 g / l, 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 had a thickness of 70 μm.
1 m at the current density of 20 A / dm ²
After plating for 0 second to form a protruding copper electrodeposit, an electrolytic solution (40 g / l containing 45 g / l of copper ions and 100 g / l of sulfuric acid) was used.
C.) and plated at 30 A / dm ² for 4 seconds. When the copper foil thus obtained was analyzed, the contents of chromium and tungsten, nickel and cobalt relative to the entire foil were as follows: chromium: about 0.1 ppm, tungsten: about 0.7 ppm, nickel: about 2 ppm, and cobalt:
About 0.6 ppm (the content in the protruding copper electrodeposit is Cr:
About 0.001 wt%, W: about 0.007 wt%, Ni:
About 0.02 wt% and Co: about 0.006 wt%). The obtained copper foil was heated and pressed on a glass cloth base epoxy resin to prepare a copper-clad laminate, and the peeling strength and the powder falling property were measured. Table 1 shows the results. Furthermore, the copper foil in which the zinc-treated layer and the rust-preventive layer were formed on the roughened layer exhibited better heat resistance and oxidation resistance.

Example 4 Contains 100 g / l of copper sulfate (pentahydrate), 100 g / l of sulfuric acid, 0.01 g / l of sodium tungstate (dihydrate), and 14 g / l of cobalt sulfate heptahydrate 30 aqueous solutions
The electrodeposited surface of a 70 μm-thick electrolytic copper foil was plated at a current density of 20 A / dm ² for 10 seconds to form a protruding copper electrodeposit at 45 ° C., and then 45 g / l of copper ions and 100 g of sulfuric acid. / L using an electrolyte solution (40 ° C) containing
/ Dm ² for 4 seconds. When the copper foil thus obtained was analyzed, the content of tungsten and cobalt with respect to the whole foil was about 0.7 ppm of tungsten.
Cobalt: about 1 ppm (the content in the protruding copper electrodeposit is W: about 0.007 wt% and Co: about 0.01
wt%). The obtained copper foil was heated and pressed on a glass cloth base epoxy resin to prepare a copper-clad laminate, and the peeling strength and the powder falling property were measured. Table 1 shows the results. Furthermore, the copper foil in which the zinc-treated layer and the rust-preventive layer were formed on the roughened layer exhibited better heat resistance and oxidation resistance.

Comparative Example 1 As an example containing no additive, 100 g of copper sulfate (pentahydrate)
/ L and an aqueous solution containing 100 g / l of sulfuric acid were used as an electrolytic bath at 30 ° C, and the surface to be bonded 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 of 45 g / l , An electrolyte containing sulfuric acid 100 g / l (40
C.) and plated at 30 A / dm ² for 4 seconds. The obtained copper foil was heated and pressed on a glass cloth base epoxy resin to prepare a copper-clad laminate, and the peeling strength and the powder falling property were measured. Table 1 shows the results.

Comparative Example 2 As a conventional example containing arsenic, copper sulfate (pentahydrate) 10
An aqueous solution containing 0 g / l, sulfuric acid 100 g / l and arsenic acid 3 g / l was used as an electrolytic bath at 30 ° C., and after plating on a surface to be bonded of a 70 μm-thick electrolytic copper foil at a current density of 20 A / dm ² for 10 seconds. , Copper ion 45g / l, sulfuric acid 100g / l
Was plated at 30 A / dm ² for 4 seconds using an electrolyte solution (40 ° C.) containing. 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 is about 1.2 wt.
%)Met. The obtained copper foil was heated and pressed on a glass cloth base epoxy resin to prepare a copper-clad laminate, and the peeling strength and the powder falling property were measured. Table 1 shows the results.

[0033]

[Table 1]

[0034]

Containing a first group metal component made of chromium or tungsten or both according to the present invention, nickel, iron, and one or of two or more second group metal component selected from cobalt and zinc The copper foil roughened by the copper electrolytic bath is uniformly treated, and exhibits excellent substrate characteristics without unevenness. When a laminate is made of a copper foil and a glass cloth base epoxy resin, a good adhesion and heat resistance are exhibited, and a rounded electrodeposit with suppressed dendrite development is formed. There is no problem of electrical characteristics and powder drop of the substrate after etching.

[Brief description of the drawings]

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Raw foil 2 Convex part 3 Roughening treatment layer 4 Copper plating layer 5 Treating plating layer 6 Rust prevention layer

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-6-169169 (JP, A) JP-A-4-96394 (JP, A) JP-A-4-96395 (JP, A) JP-A-6-169395 169170 (JP, A) JP-A-7-202367 (JP, A) JP-B 62-56677 (JP, B2) JP-B 62-56678 (JP, B2) JP-B 63-500250 (JP, A) (58) Field surveyed (Int.Cl. ⁶ , DB name) H05K 3/38 H05K 1/09

Claims (6)

(57) [Claims] To 1. A target bonding surface of the copper foil, (a) chromium and the first metal group and is one or two species selected from a first group consisting of tungsten (b) nickel, iron, cobalt, and to have a roughened layer consisting of a number of protruding copper electrodeposits containing both with one or the second metal group is 2 or more kinds <br/> selected from a second group consisting zinc or al A copper foil for printed circuits, characterized by the following. To 2. A target bonding surface of the copper foil, (a) chromium and the first metal group and is one or two species selected from a first group consisting of tungsten (b) nickel, iron, cobalt, and a roughened layer consisting of a number of protruding copper electrodeposits containing both with one or the second metal group is 2 or more kinds <br/> selected from a second group consisting zinc or et al., supra Coating the roughening layer,
It has a treat layer composed of one or more metals or alloys selected from the group consisting of copper, chromium, nickel, iron, cobalt and zinc, and a rust preventive layer covering the treat layer. Copper foil for printed circuits. 3. The copper foil for a printed circuit according to claim 2, wherein a thin copper plating layer for preventing the protruding copper electrodeposits from falling off is formed between the roughening layer and the treat layer. 4. A copper for a printed circuit, wherein a copper foil is used as a cathode in an acidic copper electrolytic bath and electrolysis is performed near a critical current density to form a roughened layer composed of a large number of projecting copper electrodeposits on the surface to be bonded of the copper foil. In the method for producing a foil, one or two selected from the first group consisting of (a) chromium and tungsten are contained in an electrolytic bath.
A first group metal as a seed: 0.0001 to 5 g / l;
(B) nickel, iron, cobalt, and one or two or more at a second group of metal selected from zinc or we made the second group:
A method for producing a copper foil for a printed circuit, characterized in that both of 0.001 to 50 g / l are present. 5. Copper, chromium,
5. The printed circuit according to claim 4, wherein a treat layer made of one or more metals or alloys selected from the group consisting of nickel, iron, cobalt and zinc is formed by electrolysis and further subjected to rust prevention treatment. Production method of copper foil for use. 6. A thin copper plating layer for preventing the protruding copper electrodeposit from falling off is formed on the formed roughened layer by electrolysis, and copper, chromium, nickel, and the like are formed on the formed copper plating layer.
5. The copper for a printed circuit according to claim 4, wherein a treat layer made of one or more metals or alloys selected from the group consisting of iron, cobalt and zinc is formed by electrolysis and further subjected to rust prevention treatment. Method of manufacturing foil.