JPH05102630A - Manufacture of copper foil with carrier and copper laminated plate using same - Google Patents

Abstract

PURPOSE:To form an ultra-thin copper laminated plate which ensures clean copper surface after the peeling and uniform copper crystal by forming a thin metal film on a plastic film, then conducting the peeling process and then conducting the copper plating. CONSTITUTION:After forming an aluminium film in the thickness of 2000Angstrom by a vacuum deposition method on a polyester film having completed the plasma processing, a silicon dioxide film is formed on this surface. Moreover, a copper layer is formed in the thickness of about 5mum by electric plating. Thereafter electrolytic roughing is carried out to obtain a copper foil with carrier. This copper foil is laid on both sides of glass cloth epoxy prepreg and a pressure of 60kg/cm<2> is applied thereto for 50 minutes at 175 deg.C. Moreover, it is heated to obtain a copper laminated plate. The polyester film carrier is peeled at the interface between the silicon dioxide film and copper plating. Moreover, the plating is conducted for the thickness of 20mum. Thereby, ultra-thin copper laminated plate having clean copper surface after the peeling and uniform copper crystal can be produced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a copper foil for printed wiring boards and a copper clad laminate.

[0002]

2. Description of the Related Art As a printed wiring board, a copper clad laminate having laminated electrolytic copper foils is generally used. In order to achieve high density of a printed wiring board in recent years, it is required that the copper surface of the copper-clad laminate has no defects and the copper foil thickness is as thin and uniform as possible. In order to meet these requirements, a copper thin film is formed on a carrier that has been subjected to a peeling treatment by a method such as sputtering, and then copper foil is prepared by electroplating.The copper foil with the carrier is laminated with a thermosetting resin prepreg and heated by heating. A method of making a copper clad laminate by pressing has been proposed (Japanese Patent Laid-Open No. 57-72851). The copper foil formed by this method is different from copper formed by sputtering or the like and the crystal structure formed by electroplating.
Composed of seed copper. Further, when the carrier sheet is a plastic film, the copper surface from which the carrier sheet is peeled off may be contaminated by the gas generated from the plastic film in the heating and pressing step in making the copper clad laminate.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and comprises a uniform copper layer,
It is an object of the present invention to provide a copper foil with a carrier, which has a clean copper foil surface when a copper clad laminate is prepared, and has an anticorrosive effect, and a copper clad laminate using the same.

[0004]

According to the present invention, a step of forming a metal thin film on a carrier sheet, a step of subjecting the surface of the metal thin film to a release treatment, and an electrical and / or chemical copper plating on the release treated surface. The step and the step of improving the adhesion of the copper plating surface are sequentially performed. In the present invention, the carrier sheet is not particularly limited, aluminum,
Any metal foil such as copper and a plastic film such as polyester or polypropylene may be used as long as it can withstand the chemicals and temperature in the subsequent process.

The metal forming the thin film may be aluminum, copper or the like as long as it can withstand the copper plating in the subsequent step. or,
The thin film forming method includes vacuum vapor deposition, sputtering, ion plating and the like, and the vacuum vapor deposition method is preferable. Further, the thickness of the thin film metal is not particularly limited, but is preferably about 500Å to 10000Å. The stripping treatment may be performed so long as the diffusion of copper atoms can be substantially ignored, and metal plating of chromium, zinc or the like may be used together. The copper plating may be ordinary electric or chemical plating, and the thickness of the plated copper is preferably about 1 μm to 35 μm. Roughening plating in the usual copper foil manufacturing process is suitable for the adhesion improving treatment with the adherend, and a coupling agent treatment such as aminosilane or epoxysilane may be used together.

According to the above, the copper surface with the carrier prepared is peeled at the peeling interface of the thermosetting resin sheet or the copper clad laminate laminated with the prepreg and the copper surface is clean, and the copper foil is uniform. It is suitable for manufacturing high-density printed wiring boards. The thermosetting resin sheet used for the copper-clad laminate may be any of an epoxy resin type, a polyimide resin type, a polymer alloy type, etc., and a prepreg is a glass cloth, a glass non-woven fabric, an epoxy type on a substrate such as paper, a polyimide. It may be impregnated with a resin such as a resin, a polyester resin, or a phenol resin.

[0007]

Example 1 An aluminum film having a thickness of 2000Å was formed on a plasma-treated polyester film by a vacuum deposition method, and then a silicon dioxide film was formed on the surface of the aluminum film. Further, a copper layer having a thickness of about 5 μm was formed by electroplating and electrolytic roughening was performed to obtain a copper foil with a carrier. This copper foil was placed on both sides of a glass cloth epoxy (commonly known as FR-4) prepreg and heated at 175 ° C. for 50 minutes under a pressure of 60 kg / cm ² to obtain a copper clad laminate. The polyester film carrier was peeled off at the interface between the silicon dioxide film and the copper plating. The peeled copper surface was clean. Further, plating of 20 μm was performed, and the peeling strength of the copper foil was measured. As a result, it was 1.4 to 1.6 kg / cm 2.

Example 2 A copper clad laminate was obtained in the same manner as in Example 1 except that the electrolytic roughening was followed by treatment with aminosilane. The peeled copper surface is clean, and the copper foil peeling strength is 1.5 to 1.8 kg / c
It was m.

[0009]

As described above, by forming a thin film layer of a metal on a plastic film, then performing a peeling treatment and performing copper plating, the copper surface after peeling is clean and the copper crystals are uniform. An extremely thin copper foil-clad laminate can be obtained.

[Brief description of drawings]

FIG. 1 is a sectional view of a copper clad laminate according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Carrier sheet 2 Metal thin film layer 3 Peeling treatment layer 4 Copper plating layer 5 Adhesion treatment layer 6 Copper foil with carrier 7 Resin or prepreg

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location C23C 28/00 Z 7217-4K

Claims (4)

[Claims] 1. A step of forming a metal thin film on a carrier sheet, a step of subjecting the surface of the metal thin film to a peeling treatment, a step of electrically and / or chemically copper plating a peeling treated surface, and an adhesive property to a copper plated surface. A method of manufacturing a copper foil with a carrier, which comprises sequentially performing a step of improving treatment. 2. The method for producing a copper foil with a carrier according to claim 1, wherein the carrier sheet is a plastic film. 3. The method for producing a copper foil with a carrier according to claim 1, wherein the peeling treatment includes a release treatment alone or a dissimilar metal plating. 4. A copper clad laminate obtained by laminating the copper foil with a carrier according to claim 1 on one side or both sides of a thermosetting resin sheet or a thermosetting resin-impregnated base material).