JP5723971B2 - Composite copper foil and method for producing the same - Google Patents

Description

  The present invention relates to a composite copper foil suitable for forming an electronic circuit by etching and a method for producing the same.

  Copper foil for printed circuits is widely used in electronic and electrical equipment, but this copper foil for printed circuits is generally used with a base material such as a synthetic resin board or film with or without an adhesive. Bonding under high temperature and high pressure to produce a copper clad laminate, then printing the circuit by resist coating and exposure process to form the desired circuit, and further through an etching process to remove unnecessary portions of the copper foil Further, various elements are soldered to form a printed circuit for an electro device.

 In recent years, a printed wiring board has a high wiring density and a small interval between connection terminals of electronic components. Inevitably, it is required to reduce the thickness of the copper foil of the copper-clad laminate. In addition, as multilayered structures of laminated plates are developed, composite copper foils such as thick copper foils / barrier layers / thin copper foils have been required for copper foils. It goes without saying that the copper foil as a starting material in manufacturing a copper-clad laminate having such a structure must have an important function.

   As a copper foil having a three-layer structure of thick copper foil / nickel layer / thin copper foil, a thick rolled copper foil or electrolytic copper foil is used as a base (support) material, and a thin nickel film is formed thereon. Form a thin copper layer on top of it. As the composite copper foil having such a configuration, a copper foil with a carrier is known (see Patent Document 1, Patent Document 2, Patent Document 3, and Patent Document 5).

 Since the copper foil with a carrier is a basic material in which a thin copper layer forms a circuit by etching, the copper layer that becomes the base of the rolled copper foil or electrolytic copper foil is finally removed by etching, and the nickel layer is also formed. Removed. An electronic circuit is formed on the thin copper layer side. In this case, the copper layer serving as the base of the rolled copper foil or the electrolytic copper foil serves to assist the handling of the thin copper foil for the circuit configuration, and the nickel layer serves as an intermediate layer, so that the circuit is formed. Sometimes removed.

Therefore, in the composite copper foil having a three-layer structure of thick copper foil / nickel layer / thin copper foil having these purposes, the adhesion between the nickel layer and the thin copper foil is peeled off during handling. If not, it's fine and isn't important.
On the other hand, there is also a document that focuses on the adhesion between the copper layer and the nickel layer. For this reason, in Patent Document 6, a proposal has been made to improve the peel resistance, with the surface roughness of the copper layer in contact with the nickel layer as a specific condition.

Since even a slight oxide film is formed on the nickel layer, the adhesion between the nickel layer and the copper layer formed on the nickel layer is rough even when the surface is roughened. The oxide film does not greatly improve the ease of peeling.
Further, a proposal has been made to form, for example, a copper layer as a thin adhesion improving layer on the nickel layer and press-contact the copper layer with a thick copper foil (see Patent Document 4).

  In addition, a clad material obtained by rolling copper with nickel sandwiched between them (see Patent Document 7 and Patent Document 8) has been proposed. However, when the different processes of the plating process and the rolling process are combined, the manufacturing cost increases, and with such a mechanical method, it is possible to obtain a copper laminated structure with a uniform thickness and as thin as possible. There is a problem that it is difficult.

Moreover, since the copper foil surface which touches a rolling roll becomes smooth by rolling, when close_contact | adherence with resin is required, it is necessary to perform a roughening process.
In any case, today, the printed wiring board has a high wiring density, and it is required to reduce the interval between the connection terminals of the electronic components. It was thought that there was no place.

JP 58-108785 A Japanese Patent No. 3680321 Japanese Patent No. 3543348 JP-A-2005-72425 Japanese Patent No. 4191977 JP-A-8-181432 International Publication WO 00-05934 Japanese Patent No. 4195162

  The present invention improves the bonding strength between nickel and copper or between copper and copper when manufacturing a copper / nickel / copper composite copper foil, and further improves the thickness accuracy of the copper layer by etching. It is an object to obtain a composite copper foil suitable for forming a circuit and a method for producing the same.

  The present inventors have found that the conventional problems can be solved by improving the nickel and copper bonding strength, which is a weak point of the conventional composite copper foil, by devising the copper and nickel plating process. Obtained. Furthermore, the knowledge that a copper layer with excellent plate thickness accuracy can be formed was obtained.

The present invention is based on this finding,
(1) A composite copper foil comprising a nickel layer having a thickness of 0.5 to 3 μm and a copper layer having a thickness of 5.1 μm or more on both sides or one side of a rolled copper foil or an electrolytic copper foil having a thickness of 10 to 150 μm. Provided is a composite copper foil characterized in that the thickness accuracy of the copper layer is less than ± 5% and the peel strength is 0.5 kg / cm or more.

The present invention also provides:
(2) Provided is the composite copper foil as described in (1) above, wherein the copper layer comprises two layers of a thin copper layer (C) and a thick copper layer (D).

The present invention also provides:
(3) The above-mentioned copper / nickel / thin copper / thick copper, wherein the thickness of the thin copper layer (C) is 0.1 to 5 μm, and the thickness of the thick copper layer (D) is 5 μm or more. The composite copper foil of 2 is provided.

The present invention also provides:
(4) The above 2 or 3, wherein a rust preventive layer having a Cr content of 10 to 50 μg / dm ² is provided on the thin copper layer (C) and / or the thick copper layer (D). Of composite copper foil.

The present invention also provides:
(5) A nickel layer (B) having a thickness of 0.5 to 3 μm is formed on both surfaces or one surface of a rolled copper foil or electrolytic copper foil (A) having a thickness of 10 to 150 μm by electroplating, and the nickel layer ( Immediately after plating in B), a thin copper layer (C) is continuously formed by electroplating, and a thick copper layer (D) is formed on this thin copper layer (C) by electroplating in a discontinuous process. A method for producing a composite copper foil is provided.

The present invention also provides:
(6) A nickel layer (B) having a thickness of 0.5 to 3 μm is formed on both surfaces or one surface of a rolled copper foil or electrolytic copper foil (A) having a thickness of 10 to 150 μm by electroplating, and the nickel layer ( Immediately after the plating of B), a thin copper layer (C) having a thickness of 0.1 to 5 μm is continuously formed by electroplating. Further, on the thin copper layer (C), a thickness of 5 μm or more is formed in a discontinuous process. Provided is a method for producing a composite copper foil, wherein a thick copper layer (D) is formed by electroplating.

The present invention also provides:
(7) The above-mentioned (5), wherein a rust preventive layer having a Cr content of 10 to 50 μg / dm ² is formed on the thin copper layer (C) and / or the thick copper layer (D). Or the manufacturing method of the composite copper foil of (6) description is provided.

The present invention also provides:
(8) A rust preventive layer having a Cr content of 10 to 50 μg / dm ² is previously formed on the thin copper layer (C), and then a thick copper layer (D) is formed. The manufacturing method of the composite copper foil as described in any one of (5)-(7) is provided.

The present invention also provides:
(9) The rust preventive layer having a Cr content of 10 to 50 μg / dm ² is formed on the thick copper layer (D) layer, any one of (5) to (7) above The manufacturing method of the composite copper foil as described in an item.

The present invention also provides:
(10) The method for producing a composite copper foil according to any one of (5) to (9) above, wherein the thin copper layer (D) is formed by electroplating using a drum-type electrode, I will provide a.
The present invention is characterized in that a slightly thicker copper layer is formed on the thin copper layer than the thin copper layer. In order to distinguish these two layers, the thin copper layer is referred to as “thin copper layer”. (C) ”, a copper layer slightly thicker than the thin copper layer (C) is expressed as“ thick copper layer (D) ”.

 The present invention can improve the bonding strength between nickel and copper when producing a copper / nickel / copper composite copper foil, and obtain a composite copper foil suitable for forming an electronic circuit by etching and a method for producing the same. It has a remarkable effect that it can be.

It is a figure which shows the example of the electroplating apparatus of a ninety nine fold (Tsurazuori) type used when manufacturing the composite copper foil which consists of copper / nickel / copper. It is a figure which shows the example of the apparatus using the drum-type electrode used when forming a slightly thicker copper layer (D) compared with a thin copper layer (C).

 In order to produce the copper / nickel / copper composite copper foil of the present invention, a ninety-nine fold type electroplating apparatus as shown in FIG. 1 can be used. As a copper foil used as a starting material, a rolled copper foil or an electrolytic copper foil (A) having a thickness of 10 to 150 μm is used. Electro-nickel plating is performed on both sides or one side of the foil (A).

 In FIG. 1, a plating layer enters from the left side of FIG. 1 and moves to the right to form a nickel plating layer having a predetermined thickness, that is, a nickel layer (B) having a thickness of 0.5 to 3 μm. In this case, if it is less than 0.5 μm, which is the lower limit of the nickel layer, pinholes are likely to occur, and if it exceeds 3 μm, which is the upper limit, the burden when finally peeling or dissolving the nickel layer increases. This is because production efficiency deteriorates.

As shown in FIG. 1, immediately after plating of this nickel layer (B), a thin copper layer (C) having a thickness of 0.1 to 5 μm is continuously formed by electroplating. This thin copper layer is characterized in that it is formed first, but this thin copper layer has an important function.
This is because the thin copper layer (C) plays a major role in suppressing the oxidation of the nickel layer (B) and improving the adhesion. The copper layer itself is rich in oxidation resistance. The minimum thickness necessary for producing this effect is 0.1 μm. When the thickness of the thin copper layer (C) exceeds 5 μm, the surface irregularities become large and the uniformity of the film thickness is lowered.

A rust preventive layer having a Cr content of 10 to 50 μg / dm ² can be formed on the thin copper layer (C). This is generally called a chromium layer or a chromate layer.
In FIG. 1, the process of forming the rust prevention layer is also illustrated, but this process is not essential. However, it is effective in the sense of suppressing some oxidation of the copper plating layer or preventing the adhesion of corrosive substances. Therefore, this rust prevention process is a preferable form.
If the Cr content is less than 10 μg / dm ² , the control of the rust preventive layer becomes difficult, so the content is made more than this. Further, if the Cr content exceeds 50 μg / dm ² , the effect is saturated and the load due to the increase in the process becomes large, so it is desirable that the upper limit value is as described above.

The copper foil that has passed through these steps hardly undergoes surface oxidation. Thereafter, a thick copper layer (D) is formed. That is, on the (A), (B), and (C), a thick copper layer (D) of 5 μm or more is formed by electroplating in a discontinuous process. That is, although the thin copper layer (C) and the thick copper layer (D) are both copper layers, they are independent plated copper layers.
This is shown in FIG. The process shown in FIG. 2 uses a drum-type electrode and circulates a copper foil around the electrode to perform electroplating. The thickness accuracy is higher than that of the 99-fold type copper plating method. Is extremely expensive. Specifically, in FIG. 2, the plating is performed once, but is not limited to this step, and can be performed once or twice or more.

 Since the thick copper layer (D) is a copper portion that forms an electronic circuit by etching, control of the thickness is important. Specifically, it is desirable that the thickness accuracy is less than ± 5%. (Note that “plate thickness accuracy” in the present specification means “±” when specifically described.) Therefore, it is necessary to form 5 μm or more on the thin copper layer (C). The upper limit is not limited, but it is preferably 20 μm or less because it is a layer forming an electronic circuit.

 In the present invention, the thickness accuracy of the thick copper layer (D) is important, but since the nickel layer (B) and the thin copper layer (C) are thin, the influence on the variation is small, and the rolled copper foil or electrolytic copper The foil (A) has been commercialized as a rolled copper foil or electrolytic copper foil, and its thickness accuracy is less than 5%, so the rolled copper foil or electrolytic copper foil (A), nickel layer (B), If the total thickness of the thin copper layer (C) and the thick copper layer (D) is the composite copper foil, and the thickness accuracy of the composite copper foil is ensured to be less than 5%, the thickness of the thick copper layer (D) The accuracy was evaluated as being less than ± 5%.

 As described above, on the nickel layer (B), on the thin copper layer (C), unlike the thin copper layer (C), the thickness can be increased by using an electrolytic plating method with high plate thickness accuracy. A controlled thick copper layer (D) will be formed, and furthermore, there will be a composite copper foil in which no delamination is observed between the nickel layer (B), thin copper layer (C), and thick copper layer (D). . This is a major feature of the present invention.

 A rust preventive layer can be further formed on the (D) layer. This is optional and is a preferred condition but not essential. In addition, the formation conditions of a rust prevention layer are the same as the above. In this case, there may be a difference in etching rate with respect to the pattern etching solution, but by appropriately selecting this amount, oxidation of the surface of the thick copper layer (D) can be further suppressed, so that a stable circuit width can be obtained. The pattern can be formed.

Examples of typical and preferable plating conditions are shown below.
(Copper plating (ninety-nine folding))
Copper: 10-50 g / l
Sulfuric acid: 50-100 g / l
Temperature: 40-60 ° C
Current density: 1-5A / dm2

(Copper plating (drum type))
Cu: 90 g / L
H ₂ SO ₄ : 80 g / L
Cl: 60ppm
Liquid temperature: 55-57 degreeC
Additive: Bis (3-sulfopropyl) disulfide disodium (CPS manufactured by RASCHIG) 50 ppm
Additive: Dibenzylamine modified 50ppm

(Nickel plating)
Nickel sulfate: 250-300 g / L
Nickel chloride: 35 to 45 g / L
Nickel acetate: 10-20g / L
Trisodium citrate: 15-30 g / L
Brightener: Saccharin, butynediol, etc. Sodium dodecyl sulfate: 30 to 100 ppm
pH: 4-6
Bath temperature: 50-70 ° C

(Conditions for chromate treatment)
Immersion chromate treatment K ₂ Cr ₂ O ₇ (Na ₂ Cr ₂ O ₇ or CrO ₃ ): 0.1 to 5 g / liter pH: 2 to 13
Temperature: normal temperature to 60 ° C
Time: 5-30 seconds

(Alkaline etching conditions)
NH ₄ OH: 6 mol / liter NH ₄ Cl: 5 mol / liter CuCl ₂ : 2 mol / liter Liquid temperature: 50 ° C.

(Nickel and chromium adhesion analysis method)
The sample is dissolved in nitric acid with a concentration of 30% until at least the nickel layer is dissolved, the solution in the beaker is diluted as appropriate, and quantitative analysis of nickel and chromium is performed by atomic absorption spectrometry.

 A copper-clad laminate is produced using the composite copper foil. When forming a circuit using this copper-clad laminate, a resist pattern for circuit formation is formed on the thick copper layer (D), and an etching solution is further added. The unnecessary portion of the laminated portion of the thick copper layer (D) and thin copper layer (C) other than the portion provided with the resist pattern is removed to the surface of the nickel layer (B). Alternatively, a multilayer circuit is formed by forming a via on the resin side.

 On the other hand, on the rolled copper foil or electrolytic copper foil (A) side, a resist pattern for bump formation is formed on (A), and unnecessary portions of (A) other than the resist pattern portion are etched to the surface of the nickel layer (B). Remove. Then, the unnecessary part of (B) is removed as needed. The removal of the unnecessary copper foil from the formation of the resist pattern is a commonly performed technique, and therefore, it is not necessary to explain much and is omitted.

 In the present invention, no peeling is observed between the rolled copper foil or electrolytic copper foil (A), nickel layer (B), thin copper layer (C), and thick copper layer (D). ) Is a bump forming layer, and (D) + (C) is characterized by the simultaneous use of a circuit forming layer. (D) After forming a resin layer on the surface, (A), in some cases May be used as a conventional application in which (B) is removed and (C) is included to form a circuit in (D).

 Moreover, since the press-contact process for improving adhesiveness like patent document 7 and 8 is not performed, the (D) surface can use the electrodeposition grain at the time of (D) formation as it is, and a roughening process is performed. And excellent adhesion to the resin. A roughening treatment may be performed.

When using copper foil, it can be applied to the roughened surface (M surface) or glossy surface (S surface) of electrolytic copper foil as well, but the surface to be etched is usually equal to or greater than the glossy surface side or glossy surface. Use smooth copper M-plane. When using a rolled copper foil, a high purity rolled copper foil or a rolled alloy copper foil with improved strength can also be used. The present invention includes all of these copper foils.
In carrying out the present invention, all of the known techniques described above can be used as long as they do not contradict the present invention.

  Next, examples and comparative examples of the present invention will be described. In addition, a present Example is an example for making an understanding easy, and is not restrict | limited to the following example. That is, the present invention encompasses all aspects or modifications other than the examples shown below within the scope of the technical idea described in the present specification.

Example 1
As the base foil, an electrolytic copper foil (A) having a thickness of 70 μm was used. This electrolytic copper foil was subjected to nickel plating (B) of 0.7 μm using the plating conditions shown in FIG. Next, an intermediate electrolytic copper plating layer (C) having a thickness of 0.2 μm was continuously formed on the nickel plating layer (B).
Furthermore, a 10 μm electrolytic copper plating layer was formed using the apparatus (drum-type electrode) shown in FIG. Thereby, the composite copper foil which consists of copper / nickel / thin copper / thick copper was manufactured.

The thickness of the copper layer made of thin copper / thick copper was measured as follows. The opposite surface (base foil side) of the copper layer made of thin copper / thick copper is pressed into FR-4 resin and masked. The sample is dissolved by alkali etching until the copper layer made of thin copper / thick copper is dissolved, and the weight thickness of copper per unit area is measured from the weight change before and after the dissolution. Furthermore, the thickness (μm) can be calculated by dividing by the specific gravity of copper of 8.93 g / (m ² · μm).

In order to obtain the thickness with high accuracy, it is desirable to measure over an area of 20 cm ² or more. The measurement is to obtain the plate thickness at 10 locations, calculate the average value, and the variation is (maximum value−average value) / average value × 100 or (average value−minimum value) / average value × 100, whichever is larger did. The evaluation was evaluated as “◯” when less than 5%, “Δ” when 5% or more but less than 10%, and “×” when 10% or more.

About adhesiveness, it laminated | stacked on the base material at 150 degreeC or more on the ultra-thin copper foil side, and measured peeling strength. When peeling was possible and the peeling strength was less than 0.5 kg / cm, “x” was given. When it did not peel or peel strength was 0.5 kg / cm or more, it was set as “◯”.
As a result, the plate thickness system was good at less than 5%, and the peel strength was 0.5 kg / cm or more, and the adhesion was good. The results are also shown in Table 1.

(Example 2)
A rolled copper foil (A) having a thickness of 12 μm was used as the base foil. This rolled copper foil was subjected to nickel plating (B) of 0.6 μm using the plating apparatus shown in FIG. Next, an intermediate electrolytic copper plating layer (C) having a thickness of 0.1 μm was continuously formed on the nickel plating layer (B).
Furthermore, a 5 μm electrolytic copper plating layer was formed using the apparatus (drum type electrode) shown in FIG. Thereby, the composite copper foil which consists of copper / nickel / thin copper / thick copper was manufactured. Other test conditions are the same as in Example 1.

  As a result, the plate thickness system was good at less than 5%, and the peel strength was 0.5 kg / cm or more, and the adhesion was good. The results are also shown in Table 1.

(Example 3)
As the base foil, a rolled copper foil (A) having a thickness of 18 μm was used. The rolled copper foil was subjected to 1 μm nickel plating (B) using the plating conditions shown in FIG. 1 and the above plating conditions. Next, an intermediate electrolytic copper plating layer (C) having a thickness of 2 μm was continuously formed on the nickel plating layer (B).
Furthermore, a 10 μm electrolytic copper plating layer was formed using the apparatus (drum-type electrode) shown in FIG. Thereby, the composite copper foil which consists of copper / nickel / thin copper / thick copper was manufactured. Other test conditions are the same as in Example 1.

  As a result, the plate thickness system was good at less than 5%, and the peel strength was 0.5 kg / cm or more, and the adhesion was good. The results are also shown in Table 1.

Example 4
As the base foil, a rolled copper foil (A) having a thickness of 35 μm was used. The rolled copper foil was subjected to nickel plating (B) of 3 μm using the plating apparatus shown in FIG. 1 and the above plating conditions. Next, an intermediate electrolytic copper plating layer (C) having a thickness of 4 μm was continuously formed on the nickel plating layer (B).
Furthermore, after chromating using the above immersion conditions, a 20 μm electrolytic copper plating layer was formed using the apparatus (drum type electrode) shown in FIG. The amount of Cr between the copper plating layer (C) and the electroplating layer (D) was 15 μg / dm ² . Thereby, the composite copper foil which consists of copper / nickel / thin copper / rust prevention layer / thick copper was manufactured. Other test conditions are the same as in Example 1.

  As a result, the plate thickness system was good at less than 5%, and the peel strength was 0.5 kg / cm or more, and the adhesion was good. The results are also shown in Table 1.

(Example 5)
As the base foil, a rolled copper foil (A) having a thickness of 18 μm was used. The rolled copper foil was subjected to 1 μm nickel plating (B) using the plating conditions shown in FIG. 1 and the above plating conditions. Next, an intermediate electrolytic copper plating layer (C) having a thickness of 2 μm was continuously formed on the nickel plating layer (B).
Furthermore, after chromating using the above immersion conditions, a 10 μm electrolytic copper plating layer was formed using the apparatus (drum-type electrode) shown in FIG. The amount of Cr between the copper plating layer (C) and the electroplating layer (D) was 45 μg / dm ² . Thereby, the composite copper foil which consists of copper / nickel / thin copper / rust prevention layer / thick copper was manufactured. Other test conditions are the same as in Example 1.

  As a result, the plate thickness system was good at less than 5%, and the peel strength was 0.5 kg / cm or more, and the adhesion was good. The results are also shown in Table 1.

(Example 6)
As the base foil, an electrolytic copper foil (A) having a thickness of 18 μm was used. The rolled copper foil was subjected to 1 μm nickel plating (B) using the plating conditions shown in FIG. 1 and the above plating conditions. Next, an intermediate electrolytic copper plating layer (C) having a thickness of 2 μm was continuously formed on the nickel plating layer (B).
Furthermore, after forming a 10-micrometer electroplating layer (D) using the apparatus (drum-type electrode) shown in FIG. 2, it chromate-treated using the said immersion conditions. The amount of Cr on the electroplating layer (D) was 30 μg / dm ² . Thereby, the composite copper foil which consists of copper / nickel / thin copper / thick copper / rust prevention layer was manufactured. Other test conditions are the same as in Example 1.

 As a result, the plate thickness system was good at less than 5%, and the peel strength was 0.5 kg / cm or more, and the adhesion was good. The results are also shown in Table 1.

(Comparative Example 1)
As the base foil, an electrolytic copper foil (A) having a thickness of 70 μm was used. This electrolytic copper foil was subjected to 1 μm nickel plating (B) using the plating conditions shown in FIG. 1 and the above plating conditions. On this (B), the 10-micrometer electroplating layer was formed using the apparatus (drum-type electrode) shown in FIG. Thereby, the composite copper foil which consists of copper / nickel / thick copper was manufactured. Other test conditions are the same as in Example 1.

  As a result, the plate thickness system was good at less than 5%, but the peel strength was less than 0.5 kg / cm and the adhesion was insufficient. The results are also shown in Table 1.

(Comparative Example 2)
As the base foil, a rolled copper foil (A) having a thickness of 70 μm was used. The rolled copper foil was subjected to nickel plating (B) of 3 μm using the plating apparatus shown in FIG. 1 and the above plating conditions. Next, an intermediate electrolytic copper plating layer (C) having a thickness of 0.01 μm was continuously formed on the nickel plating layer (B).
Further, an electrolytic copper plating layer having a thickness of 10 μm was formed on this layer (C) using the apparatus (drum type electrode) shown in FIG. Thereby, the composite copper foil which consists of copper / nickel thin copper / thin copper / thick copper was manufactured. Other test conditions are the same as in Example 1.

  As a result, the plate thickness system was good at less than 5%, and the peel strength was less than 0.5 kg / cm and the adhesion was insufficient. This is considered to be because the thickness of the intermediate electrolytic copper plating layer (C) was insufficient. The results are also shown in Table 1.

(Comparative Example 3)
As the base foil, an electrolytic copper foil (A) having a thickness of 12 μm was used. This electrolytic copper foil was subjected to 1 μm nickel plating (B) using the plating conditions shown in FIG. 1 and the above plating conditions. Next, an electrolytic copper plating layer (C) having a thickness of 20 μm was continuously formed on the nickel plating layer (B). A 10 μm electrolytic copper plating layer was formed. Thereby, the composite copper foil which consists of copper / nickel / thick copper was manufactured. Other test conditions are the same as in Example 1.

  As a result, no peeling between the nickel layer and the copper layer was observed during the process, but the plate thickness system was 10% or more. This is thought to be because thick plating was performed with the plating apparatus of FIG. The results are also shown in Table 1.

(Comparative Example 4)
A rolled copper foil (A) having a thickness of 12 μm was used as the base foil. This rolled copper foil was subjected to nickel plating (B) of 0.7 μm using the plating conditions shown in FIG. Next, an intermediate electrolytic copper plating layer (C) of 6 μm was continuously formed on the nickel plating layer (B). Furthermore, a 10 μm electrolytic copper plating layer was formed using the apparatus (drum-type electrode) shown in FIG. Thereby, the composite copper foil which consists of copper / nickel / thin copper / thick copper was manufactured. Other test conditions are the same as in Example 1.

  As a result, the peel strength was 0.5 kg / cm or more and the adhesion was good, but the plate thickness accuracy was 5% or more and less than 10%. This is thought to be due to the fact that the thickness accuracy of the thin copper layer with poor plate thickness accuracy is increased. The results are also shown in Table 1.

 The present invention can improve the bonding strength between nickel and copper when producing a copper / nickel / copper composite copper foil, and obtain a composite copper foil suitable for forming an electronic circuit by etching and a method for producing the same. It has a remarkable effect that it can be.

Claims (9)

A nickel layer having a thickness of 0.5 to 3 μm, a thin copper layer (C) having a thickness of 0.1 to 5 μm and a thick copper layer (on both sides or one side of a rolled copper foil or an electrolytic copper foil having a thickness of 10 to 150 μm ( D), the thickness accuracy of the thick copper layer (D) is less than ± 5%, and the peel strength between the nickel layer and the thin copper layer (C) is 0.5 kg / A composite copper foil characterized by being at least cm. Composite foil according to 請 Motomeko 1 you wherein the thickness of the thick copper layer (D) is 5μm or more. Wherein on the thin copper layer (C) and / or heavy copper layer (D), Cr content according to claim 1 or 2, characterized in that it comprises the anticorrosive layer is 10-50 / dm ² Composite copper foil. A nickel layer (B) having a thickness of 0.5 to 3 μm is formed on both sides or one side of a rolled copper foil or electrolytic copper foil (A) having a thickness of 10 to 150 μm by electroplating, and plating of the (B) layer is performed. Immediately after, a thin copper layer (C) is continuously formed by electroplating, and a thick copper layer (D) having a thickness accuracy of less than ± 5% in a non-continuous process is further formed on this (C) layer. A method for producing a composite copper foil, which is formed by plating. A nickel layer (B) having a thickness of 0.5 to 3 μm is formed on both sides or one side of a rolled copper foil or electrolytic copper foil (A) having a thickness of 10 to 150 μm by electroplating, and plating of the (B) layer is performed. Immediately thereafter, a thin copper layer (C) having a thickness of 0.1 to 5 μm is continuously formed by electroplating, and the thickness accuracy is more than 5 μm on the thin copper layer (C) in a discontinuous process. A method for producing a composite copper foil, comprising forming a thick copper layer (D) of less than ± 5% by electroplating. Wherein on the thin copper layer (C) and / or heavy copper layer (D), according to claim 4 or 5 Cr content and forming a rust-preventive layer is 10-50 / dm ² Manufacturing method of composite copper foil. Wherein on the thin copper layer (C), pre Cr content forming the anticorrosive layer is 10-50 / dm ^2, then according to claim 4, characterized in that to form a Atsudoso (D) The manufacturing method of the composite copper foil as described in any one of -6 . The composite copper foil according to any one of claims 4 to 6 , wherein a rust prevention layer having a Cr content of 10 to 50 µg / dm ² is formed on the thick copper layer (D). Manufacturing method. The thin copper layer (C), the method of producing composite copper foil as claimed in any one of claims 4-8, characterized in that formed by electroplating using a drum-type electrode.