TWI394870B - A polyimide-based flexible copper foil laminated sheet copper foil, a polyimide-based flexible copper foil laminated sheet, and a polyimide-based flexible printed wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyimide flexible copper clad laminate which has a high adhesive strength between a copper foil and a polyimide resin layer and has a superior insulation reliability, etching characteristics at the time of forming a wiring pattern, and bending property; and alto to provide the copper foil for the polyimide flexible copper clad laminate and a polyimide flexible printed wiring board made by processing the copper clad laminate. <P>SOLUTION: At least the surface of the copper foil consisting of a granular crystalline structure which is in contact with the polyimide resin layer is formed with a surface treatment layer. The surface treatment layer is an Ni layer and/or an Ni alloy layer which has the Ni content of 0.03-3.0 mg/dm<SP>2</SP>. The copper clad laminate is provided with the surface-treated copper foil which is bonded to the polyimide resin layer to constitute the flexible copper clad laminate, the flexible copper clad laminate using the copper foil, and the polyimide flexible printed wiring board made by processing the copper clad laminate. <P>COPYRIGHT: (C)2006,JPO&amp;NCIPI

Description

Polyimide-based flexible copper foil laminated plate copper foil, polyamidene-based flexible copper foil laminated board, and polyimide-based flexible printed wiring board

The present invention relates to a flexible printed wiring board having a polyimide film on a copper foil, which is excellent in adhesion between a copper foil and a polyimide resin layer, insulation reliability, and formation of a wiring pattern. A copper foil for a flexible copper foil laminated plate, a polyimide-based flexible copper foil laminated plate, and a polyimide-based flexible printed wiring board, which are excellent in etching properties and bending properties.

A flexible copper foil laminate in which an insulating polyimide-based resin layer is directly provided on a copper foil without an adhesive layer is called a two-layer flexible copper foil laminate, and is roughly 2 Manufacturing method. One of the methods is called casting, and is a polylysine obtained by addition polymerization of an aromatic acid dianhydride and an aromatic diamine in a solvent such as dimethylacetamide. The varnish is coated on a copper foil which has been subjected to surface roughening treatment in order to obtain high adhesion strength, and is dried to form a polyamic acid layer, which is further imidized by heating to form a polyimide resin on the copper foil. Layers are manufactured.

Another method, called laminating, is to apply a thermoplastic polyimide to a polyimide film, and to superimpose the surface roughened copper foil thereon, followed by heating and pressing to manufacture. .

In recent years, with the increase in the memory capacity of electronic devices, in electronic devices, narrow spacing of circuits and high-density packaging have progressed. Along with this, the level of mechanical properties required for a flexible copper foil laminate used as a flexible printed wiring board has also become higher. Further, with the recent high-density packaging, the flexible printed wiring board housed in the casing of the electronic device has not only an increased bending portion but also an angle at which the two surfaces forming the curved surface are formed.

Copper foil mainly has rolled copper foil and electrolytic copper foil. Conventionally, as a flexible printed wiring board, since the rolled copper foil has excellent bending characteristics, the ratio of use is high. However, recently, an electrolytic copper foil having excellent bending properties has been developed, and the ratio of use of the rolled copper foil to the electrolytic copper foil is gradually equal.

In order to improve the adhesion between the electrodeposited copper foil and the polyimide resin, the surface of the electrodeposited copper foil (untreated copper foil) of the foil produced by the electrolytic foil-making apparatus is usually subjected to metal plating to precipitate Roughening of steel particles of μ m size. Further, usually, on the surface of the electrolytic copper foil, metal plating treatment or rust prevention treatment is further applied after the roughening treatment.

Further, in the rolled copper foil, a plating layer made of copper, cobalt or nickel is known as described in Japanese Patent Publication No. Hei 6-050794.

However, a flexible printed wiring board obtained by processing the above-mentioned flexible copper foil laminate is accompanied by a small stacking technique of a semiconductor device mounted on the flexible printed wiring board or a load member such as various electronic plastic members. The development requires that the line spacing and the like be more finely patterned. However, in the conventional roughening treatment, since granular copper having a size of several μm is formed on the surface, when the fine pattern is formed by etching, the "residual root" phenomenon in which the granular copper remains on the substrate surface may occur. The etching property is impaired, and a perfect fine pattern cannot be obtained.

Further, in the case of rolling a copper foil, although the surface is relatively smooth, since a plating layer made of copper, cobalt or nickel as described above is formed, the adhesion to the polyimide layer is poor.

Therefore, in order to cope with the demand for fine patterning, attempts have been made to ensure the insulation between the patterns in order to ensure the insulation between the patterns and to prevent the occurrence of residual roots during etching, and to use electrolytic copper foil and to treat the copper foil for the printed wiring board. The surface roughness of the foil is reduced (roughness reduction). For example, Japanese Laid-Open Patent Publication No. 2004-263300 provides an excellent electrolytic copper foil as a printed wiring board by making a 10-point average surface roughness Rz of an untreated copper foil (Rz is JIS B0601). -1994 "Rz) specified in "Definition and Expression of Surface Roughness" is set to 2.5 μm or less, and the electrolytic copper foil having a minimum pitch of bare bumps of 5 μm is used to reduce the roughness.

On the other hand, the flexible printed wiring board can obtain excellent bending characteristics by reducing the thickness of the polyimide film. However, if the roughened copper foil is pressed against the surface of the polyimide film (insulating layer), the unevenness of the surface of the copper foil is inserted into the thin insulating layer, so that the insulating distance of the insulating layer becomes insufficient because of the resin. The thickness should consider the size of the surface of the copper foil. If it is too thin, it will damage the reliability of the insulation.

In order to achieve fine patterning and to obtain excellent bending properties, the roughness of the untreated copper foil is reduced, and the polyimine-based resin layer is thinned, thereby forming a flexible printed wiring board having excellent flexibility and fine patterning. It does have an effect. Further, it is effective not only to lower the roughness of the untreated copper foil, but also to reduce the particle size of the copper particles to which the surface is roughened as much as possible. However, the untreated copper foil is smoothed and the copper particles of the roughening treatment are reduced in diameter, and on the other hand, there is a problem that the adhesion strength between the copper foil and the polyimide film is lowered. In other words, if the requirements for fine patterning and high flexibility in a higher level in recent years are satisfied, the adhesion strength between the copper foil and the polyimide film layer cannot be maintained, and the adhesion between the two is insufficient. The occurrence of a problem that the copper foil (line) is peeled off from the polyimide film at the processing stage is extremely difficult, and thus it is extremely difficult to provide a satisfactory flexible printed wiring board.

The present invention solves the above problems in the prior art, and provides wood with excellent adhesion between a copper foil and a polyimide film, insulation reliability, etching characteristics when forming a wiring pattern, and bending characteristics. A copper foil for a flexible polyimide-based flexible copper foil laminate, and a polyimide-based flexible copper foil laminate having excellent flexibility for laminating the copper foil to the polyimide layer a plate; and a polyimide-based flexible printed wiring board processed with the copper foil laminate.

In order to solve the above problems, the inventors of the present invention have succeeded in developing an excellent adhesion between a copper foil and a polyimide resin layer, and excellent in insulation reliability, etching characteristics and bending characteristics when forming a wiring pattern. Polyimide-based flexible copper foil laminated plate copper foil, polyimide-based flexible copper foil laminated board, and polyimide-based flexible printed wiring board processed by the copper foil laminated board .

The surface-treated copper foil according to the first aspect of the present invention is a copper foil for a polyimide-based flexible copper foil laminate, and the surface-treated copper foil is a copper foil composed of a granular crystal structure and at least polyimine. A surface-treated layer is formed on the surface in contact with the resin layer, and the surface treatment layer is a Ni layer or/and a Ni alloy layer containing 0.03 to 3.0 mg/dm ² in terms of the amount of Ni, and is laminated on the polyimide layer. A surface-treated copper foil of a flexible printed wiring board is formed of a resin layer.

The surface-treated copper foil according to the second aspect of the present invention is a copper foil for a polyimide-based flexible copper foil laminate, and the surface-treated copper foil is a copper foil composed of a granular crystal structure and at least polyimine. A surface-treated layer is formed on the surface in contact with the resin layer, and the surface treatment layer contains a chromate layer of 0.03 to 1.0 mg/dm ² in terms of the amount of Cr, and is laminated on the polyimide layer. Surface treated copper foil for flexible printed wiring boards.

The surface-treated copper foil according to the third aspect of the present invention is a copper foil for a polyimide-based flexible copper foil laminated board, the surface-treated copper foil being at least a copper foil composed of a granular crystal structure and at least polyimine. A surface-treated layer is formed on the surface in contact with the resin layer, and the surface treatment layer contains a Cr or Cr alloy layer of 0.03 to 1.0 mg/dm ² in terms of the amount of Cr, and is laminated on the polyimide layer. A surface-treated copper foil constituting a flexible printed wiring board.

The surface-treated copper foil according to the fourth aspect of the present invention is a copper foil for a polyimide-based flexible copper foil laminated board, the surface-treated copper foil being at least a copper foil composed of a granular crystal structure and at least polyimine. A surface-treated layer is formed on the surface in contact with the resin layer, and the surface treatment layer is a Ni layer or/and a Ni alloy layer containing 0.03 to 3.0 mg/dm ² in terms of the amount of Ni, and is formed on the Ni layer and/or The upper layer of the Ni alloy layer contains a chromate layer having a Cr content of 0.03 to 1.0 mg/dm ² and a layered copper foil which is laminated on the polyimide layer to form a flexible printed wiring board.

The surface-treated copper foil according to the fifth aspect of the present invention is a copper foil for a polyimide-based flexible copper foil laminate, the surface-treated copper foil being at least a copper foil composed of a granular crystal structure and at least polyimine. A surface-treated layer is formed on the surface in contact with the resin layer, and the surface treatment layer is a Ni layer or/and a Ni alloy layer containing 0.03 to 3.0 mg/dm ² in terms of the amount of Ni, and is formed on the Ni layer and/or Or the upper layer of the Ni alloy layer contains a Cr layer and/or a Cr alloy layer of 0.03 to 1.0 mg/dm ² in terms of the amount of Cr, and is laminated on the polyimide layer to form a flexible printed wiring board. Surface treated copper foil.

Preferably, the copper foil composed of the granular crystal structure is subjected to a roughening treatment on at least one side surface of the copper iodide-based resin layer to form a copper particle layer having an average particle diameter of 1 μm or less. The aforementioned surface treatment layer is formed on the surface of the copper grain layer.

Further, it is preferable that the copper foil for a polyimine-based flexible copper foil laminate is treated with a decane coupling agent on at least the surface of the surface treatment layer.

Preferably, the copper foil composed of the granular crystal structure is an electrolytic copper foil or a rolled copper foil having a thickness of 0.5 to 70 μm, and the copper foil composed of the granular crystal structure is an electrolytic copper foil. In other cases, the surface roughness is preferably 10 points, the average roughness Rz is 2.5 μm or less, and is composed of a granular crystal structure having a minimum pitch of bare protrusions of 5 μm or more. On the other hand, in the case where the copper foil composed of the granular crystal structure is a rolled copper foil, it is preferably composed of a granular crystal structure having a surface roughness of 10 points and an average roughness Rz of 1.0 μm or less.

The sixth aspect of the present invention is a polyimide-based flexible copper foil laminate produced by using the surface-treated copper foil, and is a polyimide-based flexible printed wiring board processed by the copper foil laminate. .

The copper foil and the polyimide film of the present invention have high peel strength, and can provide insulation reliability, etching characteristics when forming a wiring pattern, and excellent bending properties. Polyimide-based flexible copper foil laminate A copper foil is used, and an excellent polyimide-based flexible copper foil laminate using the copper foil and a flexible printed wiring board obtained by processing the copper laminate are provided.

As a result of intensive studies, the present inventors have found that a copper foil composed of a granular crystal structure has better bending characteristics than a copper foil composed of a columnar crystal structure, and the present invention has been completed.

Usually, the electrolytic copper foil is a columnar crystal structure, and an electrolytic copper foil composed of a granular crystal structure can be produced by using a predetermined electrolytic solution. For example, an electrodeposited copper foil formed by a copper plating solution in which a compound having a mercapto group, a chloride ion, and a low molecular weight gel having a molecular weight of 10,000 or less and/or a polymer polysaccharide is added is formed into a granular crystal structure.

Further, the surface of the copper foil is inferior in smoothness to the copper foil composed of the columnar crystal structure, and the copper foil composed of the granular crystal structure has good smoothness and low roughness, so that the copper foil is excellent in etching property. Suitable for the use of fine patterns. Further, since the roughness is low, even if the polyimide layer is thinned, the insulation reliability is not impaired due to the unevenness of the surface of the copper foil, and the polyimide layer can be made thinner. Higher bending characteristics are obtained.

The thickness of the copper foil varies depending on the purpose of use of the flexible printed wiring board, and from the viewpoint of fine patterning of the wiring, it is preferably as thin as possible, usually 0.5 to 70 μm, preferably 3 to 18 μm. More preferably, it is 3 to 12 μm.

As described above, the low-roughness copper foil composed of a granular crystal structure is excellent in insulation reliability and high flexibility, and is suitable for use in a fine pattern. However, it cannot be obtained from a polyimide-based resin layer. Full adhesion strength. The inventors of the present invention have diligently studied in order to improve the adhesion between the copper foil and the polyimide resin layer, and as a result, by applying an appropriate surface treatment to the surface of the copper foil adhered to the polyimide layer. The adhesion of the copper foil to the polyimide film layer was successfully satisfied.

In the first surface-treated copper foil of the present embodiment, a Ni layer and/or a Ni alloy layer are provided on at least a surface of the copper foil which is in contact with the polyimide layer. By providing the Ni layer and/or the Ni alloy layer, the adhesion strength between the polyimide film and the copper foil can be improved. The Ni layer and/or the Ni alloy layer can be formed by an electroplating method, an electroless plating method, a vapor deposition method, a sputtering method, or the like, and is preferably an electroplating method from the viewpoint of easily controlling the thickness of the layer. Examples of the plating bath include a chromium sulfate plating bath, a nickel sulfate plating bath, and the like. Among them, from the viewpoint of formation cost, it is preferred to use an inexpensive nickel sulfate bath.

When the amount of coating of the Ni layer and/or the Ni alloy layer provided on the surface of the copper foil is too small, the adhesion strength to the polyimide layer is decreased, and if too much, the pattern is formed by etching. Since the fine pattern is difficult, it is at least 0.03 to 3.0 mg/dm ² in terms of metal Ni, preferably 0.05 to 1.0 mg/dm ² .

In the second surface-treated copper foil of the present embodiment, a chromate layer is provided on at least the surface of the copper foil which is in contact with the polyimide layer. By providing a chromate layer, the adhesion strength between the polyimide film and the copper foil can be improved. The chromate layer can be formed using a general chromate treatment.

When the amount of the chromate coating is too small, the adhesion strength to the polyimine-based resin layer is lowered, and if the pattern is formed too much, it becomes difficult to form a fine pattern, so that it is converted into metal Cr. 0.03 to 1.0 mg/dm ² , preferably 0.05 to 0.5 mg/dm ² .

In the third surface-treated copper foil of the present embodiment, a Cr layer or a Cr alloy layer is provided on at least the surface of the copper foil which is in contact with the polyimide layer. By providing a Cr layer or a Cr alloy layer, the adhesion strength between the polyimide film and the copper foil can be improved. The chrome layer can be formed using a general chromium treatment. When the amount of coating of the chrome layer is too small, the adhesion strength to the polyimide-based resin layer is lowered. If the pattern is etched too much, it becomes difficult to form a fine pattern. Therefore, the amount of Cr is converted to 0.03. 1.0 mg/dm ² , preferably 0.05 to 0.5 mg/dm ² .

In the fourth surface-treated copper foil of the present embodiment, a Ni layer and/or a Ni alloy layer and a chromate layer are provided on at least a surface of the copper foil which is in contact with the polyimide layer. The Ni layer and/or the Ni alloy layer and the chromate layer provided on the surface of the copper foil are preferably 0.03 to 3.0 mg/dm ² in terms of the amount of Ni, and are provided thereon in terms of the amount of Cr. 0.03~1.0mg/dm ² chromate layer. By providing a chromate layer on the nickel layer, the adhesion strength to the polyimide layer can be appropriately increased.

In the fifth surface-treated copper foil of the present embodiment, a Ni layer and/or a Ni alloy layer and a Cr and/or Cr alloy layer are provided on the copper foil at least on the surface in contact with the polyimide layer. The Ni layer and/or the Ni alloy layer provided on the surface of the copper foil is preferably 0.03 to 3.0 mg/dm ² in terms of the amount of Ni, and is contained in the amount of Cr, and contains 0.03 to 1.0 mg/ Dm ² of Cr and / or Cr alloy layer. By providing the Cr layer and/or the Cr alloy layer on the Ni layer and/or the Ni alloy layer, the adhesion strength to the polyimide layer can be appropriately increased.

Preferably, the above-mentioned surface-treated copper foil of the present invention is coated with a decane coupling agent. For the treatment of the decane coupling agent, vinyl decane, epoxy decane, styrene decane, methacryloxy decane, propylene sulfoxide, amino decane, urea decane, chloropropyl decane, decyl decane, A commercially available decane coupling agent such as a sulfide-based decane or an isocyanate-based decane. In particular, epoxy decane or amino decane is preferred for improving the adhesion to the polyimide film.

Further, a general anti-rust treatment may be applied to the surface-treated copper foil of the present invention. Examples of the general rust-preventing treatment include Zn treatment, /Zn-chromate treatment, and benzyltriazole treatment.

By using a low-roughness copper foil composed of the above-mentioned granular crystal structure and applying an optimum surface treatment, it is possible to produce an excellent polyimide-based flexibility which is excellent in adhesion strength, insulation reliability, bending property, and suitable for fine pattern use. A surface-treated copper foil for a copper-clad laminate, a polyimide-based flexible copper foil laminate using the copper foil, and a polyimide-based flexible printed wiring board in which the copper foil laminate is processed.

In order to form a fine pattern, specifically, a conventional copper foil has a line pitch of L/S=75/25 in a copper foil having a thickness of 12 μm, but can be finely used by using the copper foil of the present invention. The line spacing is L/S=25/25.

(Example)

Next, the present invention will be described in detail based on the embodiments.

This embodiment is intended to be illustrative of the invention and is not intended to limit the invention.

1. Electroplating and surface treatment conditions in the examples (1) Foil-forming conditions for forming copper foil from granular crystal structure Electroplating bath: Cu: 70-130 g/LH ₂ SO ₄ : 80-140 g/L 3-decyl- Sodium 1-propane sulfonate: 0.5~3ppm Hydroxyethyl cellulose: 1~10ppm low molecular weight glue (molecular weight 3000): 1~10ppm chloride ion: 10~50ppm Current density: 30~70A/dm ² Bath temperature: 30 ~60°C

(2) Roughening treatment conditions Electroplating bath Cu: 20~35g/LH ₂ SO ₄ : 110~160g/L Current density: 10~50A/dm ² Bath temperature: 5~35°C

(3) Nickel plating treatment conditions Electroplating bath NiSO ₄ . 7H ₂ O: 220~360g/LH ₃ BO ₃ : 20~50g/L Current density: 1~5A/dm ² Bath temperature: 15~35°C

(4) Plating treatment conditions Electroplating bath CrO ₃ : 10~300g/LH ₂ SO ₄ : 0.1~3g/L Current density: 1~10A/dm ² Bath temperature: 15~35°C

(5) Chromate treatment conditions Treatment bath: CrO ₃ : 0.5~3g/L Current density: 1~4A/dm ² Bath temperature: 15~30°C

(6) Treatment of 3-aminopropyltriethoxydecane by decane coupling agent: coating 0.1~0.5%

Example 1

Using a Ti drum as a cathode, a 12 μm copper foil composed of a granular crystal structure was prepared by the above-described foil-forming plating bath, and the rough surface of the copper foil (adhered to the opposite side of the surface of the Ti drum) was applied to Ni. The amount is 0.2 mg/dm ² of nickel plating treatment.

Example 2

Using a Ti drum as a cathode, a 12 μm copper foil composed of a granular crystal structure was prepared, and the rough surface of the copper foil (adhered to the opposite side of the surface of the Ti drum) was 1.0 mg in terms of the amount of Ni. /dm ² nickel plating treatment.

Example 3

Using a Ti drum as a cathode, a 12 μm copper foil composed of a granular crystal structure was prepared, and the rough surface of the copper foil (opposite to the surface of the Ti drum) was 0.1 in terms of the amount of metal Cr. Chromate treatment of mg/dm ² .

Example 4

Using a Ti drum as a cathode, a 12 μm copper foil composed of a granular crystal structure was prepared, and the rough surface of the copper foil (opposite to the surface of the Ti drum) was applied in an amount of 0.5 Cr. Chromate treatment of mg/dm ² .

Example 5

Using a Ti drum as a cathode, a 12 μm copper foil composed of a granular crystal structure was prepared, and the rough surface of the copper foil (opposite to the surface of the Ti drum) was applied in an amount of 0.5 Cr. Mg/dm ² is plated with Cr.

Example 6

A 12 μm copper foil composed of a granular crystal structure was prepared using a Ti drum as a cathode, and the roughness of the copper foil (opposite to the surface of the Ti drum) was 0.2 mg in terms of the amount of Ni. The Ni plating treatment of /dm ² was further carried out by a chromate treatment of 0.1 mg/dm ² in terms of the amount of metal Cr.

Example 7

A 12 μm copper foil composed of a granular crystal structure was prepared using a Ti drum as a cathode, and the roughness of the copper foil (opposite to the surface of the Ti drum) was 0.2 mg in terms of the amount of Ni. The Ni plating treatment of /dm ² was further applied to a Cr plating treatment in which the amount of metal Cr was 0.1 mg/dm ² .

Example 8

Using a Ti drum as a cathode, a 12 μm copper foil composed of a granular crystal structure was prepared, and the rough surface of the copper foil (opposite to the surface of the Ti drum) was applied in an amount of 0.4 mg in terms of the amount of Ni. The Ni plating treatment of /dm ² was further applied with a Cr plating treatment of 0.2 mg/dm ² in terms of the amount of metal Cr.

Example 9

Using a Ti drum as a cathode, a 12 μm copper foil composed of a granular crystal structure was prepared, and the rough surface of the copper foil (opposite to the surface of the Ti drum) was applied in an amount of 0.4 mg in terms of the amount of Ni. The /dm ² was subjected to Ni plating treatment, and treated with a chromate of 0.2 mg/dm ² in terms of the amount of metal Cr, and treated with a decane coupling agent.

Example 10

Using a Ti drum as a cathode, a 12 μm copper foil composed of a granular crystal structure was prepared, and the rough surface of the copper foil (adhered to the opposite side of the surface of the Ti drum) was sequentially subjected to a roughened copper particle amount of 0.02. The roughening treatment of g/dm ² , the Ni plating treatment of 0.4 mg/dm ² for the amount of Ni, the chromate treatment of 0.2 mg/dm ² for the amount of metal Cr, and the treatment with a decane coupling agent.

In the present specification, the "roughened copper grain amount" means the weight per unit area of the copper particles formed on the surface of the copper foil by the roughening treatment of the surface of the copper foil.

Example 11

Using a Ti drum as a cathode, a 12 μm copper foil composed of a granular crystal structure was prepared, and the roughened surface of the copper foil (adhered to the opposite side of the surface of the Ti drum) was sequentially subjected to a roughened copper particle amount of 0.08. The roughening treatment of g/dm ² , the Ni plating treatment of 0.4 mg/dm ² for the amount of Ni, the chromate treatment of 0.2 mg/dm ² for the amount of metal Cr, and the treatment with a decane coupling agent.

Example 12

Using a Ti drum as a cathode, a 12 μm copper foil composed of a granular crystal structure was prepared, and the shiny side of the copper foil (adhesive to the surface of the Ti drum) was applied in an amount of 0.4 mg/dm ² in terms of the amount of Ni. The Ni plating treatment was further carried out by a chromate treatment of 0.2 mg/dm ² in terms of the amount of metal Cr.

Example 13

Using a Ti drum as a cathode, a 12 μm copper foil composed of a granular crystal structure was prepared, and the rough surface of the copper foil (adhered to the surface of the Ti drum) was sequentially applied with a roughened copper particle amount of 0.02 g/dm. ² of the roughening treatment, in terms of the amount of Ni to 0.4mg / dm ² of Ni plating treatment, in terms of the amount of metallic Cr to 0.2mg / dm ² of chromate treatment.

Example 14

On a rolled copper foil of 12 μm, a Ni plating treatment of 0.4 mg/dm ² in terms of the amount of Ni was applied, and a chromate treatment of 0.2 mg/dm ² in terms of the amount of metal Cr was further applied.

Example 15

On a rolled copper foil of 12 μm, a roughening treatment of a roughened copper particle amount of 0.02 g/dm ² was applied, and a Ni plating treatment of 0.4 mg/dm ² in terms of the amount of Ni was further applied, and the amount of metal Cr was applied. In the case of 0.2 mg/dm ² chromate treatment.

Comparative example 1

Using a Ti drum as a cathode, a 12 μm copper foil composed of a granular crystal structure was prepared, and the rough surface of the copper foil (adhesive surface opposite to the Ti drum) was applied in an amount of 0.02 in terms of the amount of metal Cr. Chromate treatment of mg/dm ² .

Comparative example 2

Using a Ti drum as a cathode, a 12 μm copper foil composed of a granular crystal structure was prepared, and the rough surface of the copper foil (adhesive surface opposite to the Ti drum) was applied in an amount of 0.01 mg in terms of the amount of Ni. /dm ² is plated with Ni.

Comparative example 3

Using a Ti drum as a cathode, a 12 μm copper foil composed of a granular crystal structure was prepared, and the rough surface of the copper foil (adhered to the surface opposite to the Ti drum) was 0.1 mg in terms of the amount of Zn. The Zn plating treatment of /dm ² was further applied to a chromate treatment of 0.02 mg/dm ² in terms of the amount of metal Cr.

Comparative example 4

Using a Ti drum as a cathode, a 12 μm copper foil composed of a granular crystal structure was prepared, and the shiny surface of the copper foil (adhesive to the surface of the Ti drum) was applied in an amount of 0.12 mg/dm in terms of the amount of Zn. The Zn plating treatment of ² was further applied to a chromate treatment of 0.02 mg/dm ² in terms of the amount of metal Cr.

Comparative Example 5

On a rolled copper foil of 12 μm, a Zn plating treatment of 0.1 mg/dm ² in terms of the amount of Zn was applied, and a chromate treatment of 0.02 mg/dm ^{2 in} terms of metal Cr was further applied.

The average particle diameter, Rz, metal adhesion amount, and peel strength of the roughened copper particles of Examples 1 to 15 and Comparative Examples 1 to 5 were measured, and the results are shown in Tables 1 and 2.

The peel strength in the table is applied to the surface treated copper foil, coated with polyamic acid varnish, and dried in stages without blistering, and then under a nitrogen atmosphere at 330 ° C (30 minutes). Amination to prepare a 25 μm thick polyimide-based flexible copper foil laminate, and patterning the copper foil to measure the adhesion strength (peel strength) (kN/m) at 23 ° C .

Each of the examples and comparative examples was compared in Tables 1 and 2.

Example 1 coated with Ni in an amount of 0.2 mg/dm ² , Example ² coated with a Ni amount of 1.0 mg/dm ² , Example 3 in which chromate was coated with a metal Cr amount of 0.1 mg/dm ² , and chromic acid The salt was coated with the metal Cr amount of 0.5 mg/dm ² , the chromium layer was coated with the metal Cr amount of 0.5 mg/dm ² , the Ni amount was 0.2 mg/dm ^{2 , and the} chromate was metal. Example 6, the amount of Ni to 0.2mg / dm ² and then the chromium layer covering the amount of Cr embodiment 0.1mg / dm ² coating of 0.1mg / ² dm of the metal coating amount of Cr 7 and Comparative Examples 1 to 3 and Comparative peeling The strength is increased.

In the example in which the amount of Ni is 0.4 mg/dm ² and the amount of Cr is 0.2 mg/dm ^{2 to} coat the chromic acid layer, the amount of Ni and the amount of Cr in the coating is higher than that of Example 6. .

EXAMPLES With respect to Example 8, the peel strength was higher by further applying a decane coupling agent.

In Example 10, with respect to Example 9, by applying a roughening treatment (roughened copper particles of 0.02 g/dm ² ), the peel strength was higher.

In Example 11, with respect to Example 10, the peeling strength was higher by applying a roughening treatment (roughening copper particles amount of 0.08 g/dm ² ).

In the case where the Ni amount is 0.4 mg/dm ² and the metal amount Cr is 0.2 mg/dm ^{2 , the} chromic acid layer is coated with the chromic acid layer. Compared with the comparative example 4, the amount of Ni and the amount of metal Cr are increased by a large amount, and the peel strength is further increased. high.

In Example 13, with respect to Example 12, the peeling strength was higher by applying a roughening treatment (roughened copper particles of 0.02 g/dm ² ).

In the case where the Ni amount is 0.4 mg/dm ² and the metal amount Cr is 0.2 mg/dm ^{2 , the} chromic acid layer is coated with the chromic acid layer. Compared with the comparative example 5, the amount of Ni and the amount of metal Cr are increased by a large amount, and the peel strength is further increased. high.

In Example 15, with respect to Example 14, by applying a roughening treatment (roughened copper particles of 0.02 g/dm ² ), the peel strength was higher.

On the surface-treated copper foil prepared in the examples and the comparative examples, a polyamic acid varnish was applied and dried in a non-foamed state, and then dried at 330 ° C (30 minutes) under a nitrogen atmosphere. The laminate was formed into a 25 μm thick polyimide-based flexible copper foil laminate, and the copper foil was patterned. As a result, the surface-treated copper foil was produced in the examples to maintain high peel strength, and a fine pattern having a line pitch L/S = 25/25 was formed, and insulation reliability was ensured.

Further, in the comparative example, the fine pattern of the line L/S = 25/25 was formed under the same conditions as in the examples, but the peel strength was insufficient, and a satisfactory polyimide-based flexible printed wiring board could not be produced.

The copper foil of the present invention can be obtained with a high peel strength by applying an appropriate surface treatment. In addition, it is possible to provide a copper foil for a polyimide-based flexible copper foil laminate which is excellent in insulation reliability, bending property, and fine pattern by using a low roughness, and a polyimide film using the copper foil. Flexible copper foil laminate and polyimide-based flexible printed wiring board.

Claims (11)

A copper foil for a flexible bismuth-based flexible copper foil laminate, which is a surface-treated copper foil which is adhered to a polyimide-based resin layer and constitutes a flexible copper foil laminate, characterized in that the surface treatment The copper foil is formed with a surface treatment layer on at least a surface of the copper foil composed of the granular crystal structure in contact with the polyimide layer, and the surface treatment layer is at least a Ni layer containing a Ni content of 0.03 to 3.0 mg/dm ² . Or a Ni alloy layer in which a copper foil composed of a granular crystal structure is subjected to at least a single-side surface in contact with the polyimide-based resin layer to be a copper grain layer having an average particle diameter of 1 μm or less, and The aforementioned surface treatment layer is formed on the surface of the copper grain layer. A copper foil for a flexible bismuth-based flexible copper foil laminate, which is a surface-treated copper foil which is adhered to a polyimide-based resin layer and constitutes a flexible copper foil laminate, characterized in that the surface treatment The copper foil has a surface treatment layer formed on the surface of the copper foil composed of the granular crystal structure at least in contact with the polyimide layer, and the surface treatment layer is a chromate containing a Cr content of 0.03 to 1.0 mg/dm ² . a layer in which a copper foil composed of a granular crystal structure is subjected to at least a single-side surface in contact with the polyimide-based resin layer to be a copper grain layer having an average particle diameter of 1 μm or less, and a copper grain layer is formed thereon. The aforementioned surface treatment layer is formed on the surface. A copper foil for a flexible bismuth-based flexible copper foil laminate, which is a surface-treated copper foil which is adhered to a polyimide-based resin layer and constitutes a flexible copper foil laminate, characterized in that the surface treatment The copper foil is formed with a surface treatment layer on a surface of the copper foil composed of the granular crystal structure at least in contact with the polyimide film, and the surface treatment layer is a Cr layer containing a Cr amount of 0.03 to 1.0 mg/dm ² or a Cr alloy layer in which a copper foil composed of a granular crystal structure is subjected to at least a single-side surface in contact with the polyimide-based resin layer to be a copper grain layer having an average particle diameter of 1 μm or less, and the copper alloy layer is formed thereon. The aforementioned surface treatment layer is formed on the surface of the granular layer. A copper foil for a flexible bismuth-based flexible copper foil laminate, which is a surface-treated copper foil which is adhered to a polyimide-based resin layer and constitutes a flexible copper foil laminate, characterized in that the surface treatment The copper foil is formed with a surface treatment layer on at least a surface of the copper foil composed of the granular crystal structure in contact with the polyimide layer, and the surface treatment layer is at least a Ni layer containing a Ni content of 0.03 to 3.0 mg/dm ² . Or a Ni alloy layer and a layer formed on the Ni layer or the Ni alloy layer containing a Cr salt layer having a Cr content of 0.03 to 1.0 mg/dm ² , wherein the copper foil composed of the granular crystal structure is at least a polyimine The one-side surface in contact with the resin layer is subjected to a roughening treatment to form a copper particle layer having an average particle diameter of 1 μm or less, and the surface treatment layer is formed on the surface of the copper particle layer. A copper foil for a flexible bismuth-based flexible copper foil laminate, which is a surface-treated copper foil which is adhered to a polyimide-based resin layer and constitutes a flexible copper foil laminate, characterized in that the surface treatment The copper foil is formed with a surface treatment layer on at least a surface of the copper foil composed of the granular crystal structure in contact with the polyimide layer, and the surface treatment layer is at least a Ni layer containing a Ni content of 0.03 to 3.0 mg/dm ² . Or a Ni alloy layer and a layer formed on the Ni layer or the Ni alloy layer containing a Cr layer or a Cr alloy layer having a Cr content of 0.03 to 1.0 mg/dm ² , wherein the copper foil composed of the granular crystal structure is at least mixed with the polyfluorene The one-side surface in contact with the imide-based resin layer is subjected to a roughening treatment to form a copper particle layer having an average particle diameter of 1 μm or less, and the surface-treated layer is formed on the surface of the copper particle layer. The copper foil for a polyethylenimine-based flexible copper foil laminate according to any one of claims 1 to 5, wherein at least the surface of the surface treatment layer is applied to the surface-treated copper foil. Treatment with decane coupling agent. The copper foil for a polyethylenimine-based flexible copper foil laminate according to any one of claims 1 to 5, wherein the copper foil composed of the granular crystal structure is an electrolytic copper foil or a rolled copper. The foil has a thickness of 0.5 to 70 μm. The copper foil for a polyethylenimine-based flexible copper foil laminate according to any one of claims 1 to 5, wherein the copper foil composed of the granular crystal structure is an electrolytic copper foil, the surface thereof The roughness is: 10 points, the average roughness Rz is 2.5 μm or less, and the minimum pitch of the bare protrusions is 5 μm or more. The composition of the granular crystal structure. The copper foil for a polyethylenimine-based flexible copper foil laminate according to any one of claims 1 to 5, wherein the copper foil composed of the granular crystal structure is a rolled copper foil, which is a surface The roughness is a granular crystal structure having a 10-point average roughness Rz of 1.0 μm or less. A polyimide-based flexible copper foil laminate, which is produced by using a copper foil for a polyethylenimine-based flexible copper foil laminate according to any one of claims 1 to 5. A polyamidene-based flexible printed wiring board produced by using a polyimide-based flexible copper foil laminated board of claim 10 of the patent application.