WO2002100136A1

WO2002100136A1 - Composite copper foil with copper or copper alloy support body, and printed circuit board using the composite copper foil

Info

Publication number: WO2002100136A1
Application number: PCT/JP2002/005179
Authority: WO
Inventors: Naonori Michishita; Mikio Hanafusa
Original assignee: Nikko Materials Company, Limited
Priority date: 2001-06-04
Filing date: 2002-05-29
Publication date: 2002-12-12
Also published as: TW573079B; JP2002368365A; JP4672907B2

Abstract

A composite copper foil having a copper or copper alloy support body, characterized by comprising a nickel layer covered with oxide film between the copper or copper alloy support body and a very thin copper foil on the support body side, and a printed circuit board using the composite copper foil, whereby the easiness of handling of the very thin copper foil can be improved, contaminants such as resin powder of a prepreg sheet can be prevented from adhering to the surface of the copper foil, damage and dents by foreign matter can be effectively prevented from occurring, and damage, entry of foreign matter, wrinkles, and bending during normal cutting, packaging, and transportation can be prevented from occurring.

Description

Description: Composite copper foil provided with copper or copper alloy support and printed circuit board using the composite copper foil

The present invention improves the handleability of an ultra-thin copper foil, prevents contaminants such as resin powder of a pre-prepared sheet from adhering to the surface of the copper foil, and furthermore, copper or a copper alloy which is effective in preventing scratches and dents due to foreign matter. And a printed circuit board using the composite copper foil. Background art

The copper-clad laminate used in Agata and printed corridors is made of copper-foil paper-phenol machine! ^ It is formed by laminating on a glass-epoxy shelf and heating it with a press. Pressing it, or by continuously laminating and heating a copper foil roll and resin. In addition, a circuit network is formed on the copper-clad laminate through processes such as etching, and a semi-difficult element is mounted to produce a port for electrons β.

In general, when pressing a copper foil using a press or a laminating device, foreign matter such as copper chips generated when cutting the copper foil or the appearance of a pre-preda is attached to the glossy surface (S side) of the copper foil. In addition, there is a problem that the glossy surface may be damaged or foreign matter may adhere to the glossy surface. It was sometimes small.

In recent years, the circuit width has become significantly smaller due to the demand for smaller electronic devices, and the thickness of copper foil used for copper-clad laminates has been reduced to 12 or less. Demand is growing.

However, when the thickness of the copper foil is reduced to 12 m or less, handling becomes extremely poor. Not only in the press and lamination processes described above, but also during normal cutting, packing and transporting, scratches, foreign substances are mixed, wrinkles, breaks, etc. often occur, especially the gloss of copper foil On the other hand, there is a problem that the system is easily affected by the influence. Such scratches, wrinkles, and breaks, especially when they occur on the glossy side, can cause circuit breaks and short circuits, which can lead to defects in printed circuit boards and electronic equipment, which is a major problem. ing.

Several proposals have been made to prevent the above-mentioned scratches, wrinkles, and breaks on the copper foil surface and to improve the handleability. For example, there is a proposal to bond a resin film made of polyamide or the like that can withstand the heating temperature (about 170 ° C.) during press molding to a copper foil using an adhesive.

However, with such a resin film, wrinkles and folds cannot be effectively prevented because a strength sufficient to improve the handleability of the copper foil cannot be obtained unless a considerably thick film is used.ゃ The adhesive may be deformed due to expansion and contraction due to heat, and the adhesive used for bonding the film may remain on the copper foil and cause contamination, which is not necessarily a good improvement measure. Did not.

It has also been proposed to use an aluminum foil instead of a resin film and bond it to a copper foil using an adhesive.

However, the aluminum foil used is usually manufactured by rolling, and the rolling oil used at that time remains and is transferred to the copper foil at the time of bonding, and this causes the resist adhesion during the production of the printed circuit board. The problem of deterioration occurred.

Although it is possible to remove rolling oil by degreasing aluminum foil or annealing at high temperatures, there is a problem that costs increase. Also, annealing at high temperatures softens the aluminum foil and lowers its strength, so it must be considerably thicker in order to be used as a carrier, resulting in increased costs and increased weight. In addition to such a problem of rolling oil residue, aluminum foil had another problem that aluminum powder on the surface was transferred to the copper foil during pressing, causing disconnection and short circuit of the circuit.

Furthermore, there is a proposal of a composite copper foil using an organic and nickel as a release layer. However, in this case, there is a disadvantage that the peeling layer diffuses into the copper or copper alloy support and the ultra-thin copper foil during lamination pressing with the resin, and there is a problem in peeling from the copper or copper alloy support. Was. Disclosure of the invention

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to improve the handleability of ultra-thin copper foil and to prevent contamination of the copper foil surface such as resin powder of a pre-preda sheet on the copper foil surface. Equipped with a copper or copper alloy support (carrier) that can prevent foreign matter from being attached and prevent scratches and dents due to foreign matter, and can also effectively prevent scratches, wrinkles, and breaks during cutting, packing, and transportation. It is an object to obtain a composite copper foil and a printed circuit board using the composite copper foil.

From the above, the present invention

1. Composite copper provided with a copper or copper alloy support, which has a nickel layer covered with an oxide film on the support side between the copper or copper alloy support and the ultra-thin copper foil And a printed circuit board using the composite copper foil.

2. A composite copper foil provided with a copper or copper alloy support as described in 1 above, having a nickel layer of 0.05 to 5.0 m, and a printed circuit board using the composite copper foil.

3. The composite copper foil provided with the copper or copper alloy support according to 1 or 2 above, wherein the thickness of the oxide film of the nickel layer is 25 to 50 OA, and the composite copper foil is used. Printed circuit board.

4. The composite copper foil provided with the copper or copper alloy support according to any one of the above 1 to 3, wherein the thickness of the copper or copper alloy support is 15 to 70 m, Printed circuit board using composite copper foil.

5. The composite copper foil provided with the copper or copper alloy support according to any one of the above 1 to 4, wherein the copper or copper alloy support is an electrolytic copper foil or a rolled copper foil. Printed circuit board using foil.

6. The copper or copper alloy according to any one of the above items 1 to 5, wherein the thickness of the ultrathin copper foil supported on the copper or copper alloy support is 0.5 to 12 ^ m. And a printed circuit board using the composite copper foil.

7. The copper or copper alloy support according to any one of 1 to 6 above, wherein the peel strength between the ultra-thin copper foil and the nickel layer is 0.02 to 0.5 kg Z cm. The composite copper foil provided and a printed circuit board using the composite copper foil.

I will provide a. Embodiment of the Invention

The composite copper foil provided with the copper or copper alloy support of the present invention and the printed substrate using the composite copper foil are first provided with a surface of the copper or copper alloy having a thickness of 0.05 to 5.0 m. A nickel plating layer is formed. Preferred examples of conditions for forming the nickel plating layer are shown below.

Nickel plating

Nickel concentration: 10 to 80 gZL

Electrolyte temperature: 20-80 ° C

0. SOAZdm ²

pH 1.0-5.0

An oxidation film is further formed on the surface of the nickel layer. The thickness of this oxide film is desirably 25 to 50 OA. The oxide film can significantly improve the peelability of the ultra-thin copper foil. Anodization is a means for forming an oxide film on this nickel layer. A preferred example of the conditions for forming the oxide film is shown below.

Oxide film formation

NaOH concentration: 0.5-20 g / L

Electrolyte temperature: 20-50 ° C

Current density: l ~ 10AZdm ²

Then, an ultra-thin copper foil is formed on the oxide film. The thickness of the ultra-thin copper foil is desirably 0.5 to 12 / m. The ultra-thin copper foil is formed by electroplating. One example of preferable conditions for the copper plating is shown below.

Copper plating

Copper concentration: 30-120 g / L

H ₂ S0 ₄ concentration: 20~: L 20 g / L

20-80 ° C

10 ~: L 00 AZdm ² As a result, a composite copper foil provided with a copper or copper alloy support is obtained. Further, the laminated composite copper foil and the resin base material are laminated by pressing or laminating to form a copper-clad laminate. The composite copper foil provided with the copper or copper alloy support is handled. Due to its extremely good properties, it is possible to effectively prevent the occurrence of wrinkles, breaks, and the like, and it is possible to prevent foreign substances from directly adhering to the copper foil surface by covering with a copper or copper alloy support.

Further, after lamination, the copper or copper alloy support is peeled off from the nickel layer portion having an oxide film, and a circuit network is formed by a process such as etching. Protected by a copper or copper alloy support, which is effective in preventing scratches and dents due to foreign matter on copper-clad laminates, and is also effective in cutting, packing, transporting scratches, wrinkles, breaks, etc. Can be prevented.

As the copper or copper alloy support used in the copper foil of the present invention, an electrolytic copper foil or a rolled copper foil can be used. Its preferred thickness is between 15 and 70 / m. It is desirable to use thinner electrolytic copper foil or rolled copper foil in terms of cost, but if it is too thin, it cannot be used as a support (carrier) due to its strength, so a certain thickness or more is necessary.

The peel strength between the ultra-thin copper foil and the nickel layer having an oxide film layer formed on the surface is 0.002 to 0.5 kg Z cm ² , and it can be easily peeled. The peel strength in this case indicates a value when the composite copper foil is laminated on a substrate at 150 ° C. or more on the ultra-thin copper foil side. The copper foil surface on which the nickel layer is formed is preferably applied to the glossy surface (S), but may be applied to another surface, that is, the roughened surface (M surface). Also, it may be applied to the copper foil surface which has been subjected to another surface treatment such as plating.

For example, copper foil for printed wiring boards is generally subjected to formation of roughened particles, formation of an oxide film, formation of a heat-resistant film, anti-reflection treatment, etc., and these treatments can be applied to the present invention. It encompasses all of these.

By way of example of the copper foil laminating step, for example 1 0~3 0 kg / cm ² about the pressing pressure, pressing temperature 1 7 0 ° C before and after 6 0-1 8 0 min, laminated added heat and pressure I do. Thereby, the joining between the copper foil and the pre-preda sheet can be sufficiently performed. In addition, the composite copper foil provided with a copper or copper alloy support has extremely good nodling properties, so that wrinkles, breaks, and the like do not occur. In particular, when the thickness of the ultra-thin copper foil is 12 or less, the handling property is remarkably improved. Further, the present invention is not limited to the above-described pressing step, and has an effect that scratches, foreign substances, wrinkles, breaks, and the like do not occur during normal cutting and packing, and during transportation.

This has the effect of reducing cuts and short circuits in the circuit of the printed circuit board, suppressing defects in electronic equipment, and improving product yield.

After the lamination, the copper or copper alloy support having the nickel layer provided with the oxide film can be easily removed and removed from the ultra-thin copper foil. The foil or sheet as support for copper or copper alloy for the carrier can be recycled.

This improves the handling of ultra-thin copper foil, prevents contaminants such as resin powder of pre-preducted resin from adhering to the copper foil surface, prevents scratches and dents due to foreign matter, and further cuts, packs, and transports A printed circuit board can be easily obtained without causing scratches, wrinkles, or breaks in the inside. Examples and comparative examples

Next, examples of the present invention and comparative examples will be described. Note that the present embodiment is merely an example, and the present invention is not limited to this example. That is, all aspects or modifications other than the present embodiment are included within the technical idea of the present invention.

(Example 1)

Nickel plating with a thickness of 0.1 zm was performed on the surface of the electrolytic copper foil S having a thickness of 35 m as a support copper metal layer under the conditions of the nickel plating described above. Then, an oxide film of 45 A was formed on the surface of the nickel plating by anodic oxidation under the above conditions. The time of this anodic oxidation was 10 seconds. Measurement of oxide film thickness was measured with S i 0 ₂ conversion using Oje electron spectroscopy (hereinafter, the measurement of the oxide film thickness was the same). Further, on the nickel film having an oxide film formed on the support copper metal, copper having a thickness of 5 am was deposited under the conditions of the copper plating.

Next, this composite copper foil was laminated on a pre-predator FR-4 and pressed at 175 ° C. for 30 minutes under a condition of 35 kg / cm ² to obtain a copper-clad laminate. Table 1 shows the results of observing the occurrence of wrinkling and examining the peel strength of the composite copper foil provided with the copper or copper alloy support of Example 1 thus obtained. As shown in Table 1, the exfoliation property between the ultra-thin copper foil and the copper or copper alloy support having a nigger coating was good, wrinkles did not occur, and the handling property was good.

(Example 2)

In the same manner as in Example 1, nickel plating having a thickness of 0.5 μπι was performed on the surface of the electrolytic copper foil S having a thickness of 35 m as a support copper metal layer under the above-described nickel plating conditions. Then, an oxide film of 5OA was formed on the surface of the nickel plating by anodic oxidation under the above conditions. The time of this anodizing was 30 seconds. Further, on the nickel film having an oxide film formed on the support copper metal, copper having a thickness of 7 iim was deposited under the conditions of the copper plating.

Next, as in Example 1, the composite copper foil was laminated on a pre-predator FR-4, and pressed at 175 ° C. for 30 minutes under a condition of 35 kg / cm ² to obtain a copper-clad laminate. I got Table 1 also shows the results of observing the occurrence of wrinkling and examining the peel strength of the composite copper foil provided with the copper or copper alloy support of Example 2 thus obtained. As shown in Table 1, the peelability between the ultra-thin copper foil and the copper or copper alloy support having a nickel coating was good, no wrinkles were generated, and the eight-handling property was good. (Example 3)

In the same manner as in Example 1, a 0.1 m-thick nickel plating was performed on the 35 m-thick electrolytic copper foil S surface as a support copper metal layer under the above-described nickel plating conditions. Then, a 25 A oxide film was formed on the surface of the nickel plating by anodic oxidation under the above conditions. The time of this anodization was 1 second. Further, on the nickel film having an oxide film formed on the support copper metal, copper having a thickness of 5 m was deposited under the conditions of the copper plating.

Next, in the same manner as in Example 1, this composite copper foil was laminated on a pre-predator FR-4, and pressed at 175 ° C. for 30 minutes under a condition of 35 kg / cm ² to obtain a copper-clad laminate. Table 1 also shows the results of observing the occurrence of wrinkling and examining the peel strength of the composite copper foil provided with the copper or copper alloy support of Example 3 thus obtained. As shown in Table 1, the peelability between the ultra-thin copper foil and the copper or copper alloy support having a nickel coating was good, wrinkles did not occur, and the handling property was good.

(Example 4)

In the same manner as in Example 1, a 0.1 m-thick nickel plating was performed on the 35 / zm-thick electrolytic copper foil S surface as the support copper metal layer under the above-described nickel plating conditions. An oxide film of 46 OA was formed on the surface of the nickel plating by anodic oxidation under the above conditions. The time of this anodic oxidation was 60 seconds. Further, on the nickel film having an oxidation film formed on the support copper metal, copper having a thickness of 5 m was deposited under the conditions of the copper plating.

Next, in the same manner as in Example 1, this composite copper foil was laminated on a pre-predator FR-4, and pressed at 175 ° C. for 30 minutes under a condition of 35 kg / cm ² to obtain a copper-clad laminate. Table 1 also shows the results of observing the occurrence of wrinkling and examining the peel strength of the composite copper foil provided with the copper or copper alloy support of Example 4 obtained in this manner. As shown in Table 1, the releasability between the ultra-thin copper foil and the copper or copper alloy support having the nigger coating was good, wrinkles did not occur, and the handling property was good. (Comparative Example 1)

Nickel plating with a thickness of 0.1 m was performed on the surface of the electrolytic copper foil S having a thickness of 35 ^ m as a support copper metal layer under the conditions of the nickel plating. Then, a copper having a thickness of 5 m was deposited on the surface of the nickel plating without performing anodic oxidation under the conditions for the copper plating. The thickness of the nickel oxide film without anodic oxidation was 2 OA.

Next, the composite copper foil was laminated on the pre-predeer FR-4 in the same manner as in Example 1, and pressed at 175 ° C for 30 minutes at 35 kg / cm ² to obtain a copper-clad laminate. I got Table 1 also shows the results of observing the occurrence of wrinkling and examining the peel strength of the composite copper foil provided with the copper or copper alloy support of Comparative Example 1 thus obtained.

As is evident from Table 1, Comparative Example 1 had good handling properties and no wrinkles were observed. However, when a peeling test was performed by applying an adhesive tape and peeling it off, it was impossible to peel. Bad result.

In contrast to the results of the above comparative examples, in Examples 1 and 2, as described above, the handleability was good and no wrinkles occurred, and the peel strengths of Examples 1 and 2 were all 0. 0.25 kg g cm, showing good peelability.

Thus, a nickel plating layer is formed on the surface of the copper or copper alloy support of the present invention, and an oxidation film is further formed on the surface of the nickel layer. The copper-clad laminate (printed circuit board) is excellent in that a composite copper foil provided with a copper or copper alloy support formed with a foil, and the laminated composite copper foil and a resin base material are laminated by pressing or laminating. It can be seen that it has characteristics. The invention's effect

A composite copper foil of the present invention comprising a copper or copper alloy support, a nickel layer provided with an oxide film between the copper or copper alloy support and the ultra-thin copper foil, and the composite copper foil. The printed circuit board used improves the handling of ultra-thin copper foil, prevents contaminants such as resin powder of prepreg from adhering to the copper foil surface, and is effective in preventing scratches and dents due to foreign matter. In addition, it has an excellent effect of preventing the occurrence of scratches, foreign substances, wrinkles, breaks, and the like during normal cutting, packing, and transportation.

Claims

Scope of the claim 1. A copper or copper alloy support, characterized by having a nickel layer covered with an oxide film on the support side between the copper or copper alloy support and the ultra-thin copper foil And a printed circuit board using the composite copper foil.

2. A composite copper foil provided with a copper or copper alloy support according to claim 1 having a nickel layer of 0.05 to 5.0 m, and a preform using the composite copper foil. Board.

3. The composite copper foil provided with a copper or copper alloy support according to claim 1 or 2, wherein the thickness of the oxide film of the nickel layer is 25 to 50 OA. Printed circuit board using composite copper foil.

4. The copper or copper alloy support according to any one of claims 1 to 3, wherein the copper or copper alloy support has a thickness of 15 to 70 / m. A composite copper foil and a printed circuit board using the composite copper foil.

5. A composite comprising a copper or copper alloy support according to any one of claims 1 to 4, wherein the copper or copper alloy support is an electrolytic copper foil or a rolled copper foil. A copper foil and a printed circuit board using the composite copper foil.

6. The copper according to any one of claims 1 to 5, wherein the thickness of the ultra-thin copper foil supported on the copper or copper alloy support is 0.5 to 12 m. Or a composite copper foil provided with a copper alloy support and a printed circuit board using the composite copper foil.

7. The copper or copper alloy according to any one of claims 1 to 6, wherein the peel strength between the ultra-thin copper foil and the nickel layer is 0.002 to 0.5 kg / cm. And a printed circuit board using the composite copper foil.