JP2002187235A - Method of manufacturing cupper foil with resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a cupper foil with a resin capable of uniformly forming a cupper foil having a thickness of 9 μm or below while suppressing a cost increase. SOLUTION: The cupper foil 8A with a resin is manufactured by overlapping two cupper foils 2A and 2B, applying a cold rolling so that at least one of the cupper foil 2A has a defined thickness or below, coating one surface of the cupper foil 2A having the defined thickness or below with a thermoset resin composition 5, heating the coated cupper foil, and pealing the two cupper foils 2A and 2B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the production of a resin-coated copper foil which is used alone as a printed wiring board or is generally used as a laminated material of a build-up multilayer printed wiring board (hereinafter, referred to as a multilayer wiring board). More particularly, the present invention relates to a method for producing a resin-attached copper foil capable of uniformly forming a copper foil having a thickness of 9 μm or less.

[0002]

2. Description of the Related Art Conventionally, the following method has been employed as one method of manufacturing a multilayer wiring board. First, for example, a copper foil with a resin is laminated on a wiring board that becomes a core by forming a circuit pattern by laminating a copper foil on a glass cloth base epoxy resin.
Next, after removing the copper foil layer at the place where the micro via of the resin-coated copper foil is to be formed by etching in advance, the micro via is formed by a carbon dioxide laser, and further, a predetermined thickness (15 to 20 μm) is obtained by panel plating. A desired wiring circuit is formed by performing copper plating, and finally, a treatment such as a solder resist is performed to obtain a product. In the case of further multi-layering, the lamination of the copper foil with resin and the formation of the wiring circuit are repeated.

The copper foil with resin used here has a thickness of 12 to 35 μm. This is because when the thickness is 12 μm or less, the handling property such as wrinkles and breakage is extremely deteriorated.

In recent years, the wiring technology of semiconductor devices has been miniaturized year by year, and the number of I / O pads of a package has been steadily increasing. Along with this, printed wiring boards on which these are mounted are also required to have higher density and fine patterns, and line and space dimensions are 15 to 4 mm.
A thickness of 0 μm is required.

However, according to the copper foil with resin described above,
Since the thickness of the copper foil is as large as 12 to 35 μm, when forming a wiring circuit, it takes a long time to perform etching, and the etching proceeds in the plane direction in addition to the thickness direction. There was a problem that the shape was disturbed. When the thickness of the copper foil layer is 12 μm or more, it is said that the limit of the line and space dimensions is 50 μm.

On the other hand, as a method for producing a resin-coated copper foil capable of solving this problem, for example, Japanese Patent Application Laid-Open No.
Is disclosed in Japanese Unexamined Patent Application Publication No. 2000-205,878. In this method of manufacturing a copper foil with resin, in consideration of handleability of a thin copper foil, copper, aluminum, iron, paper and resin are selected as carriers, and an ultra-thin copper foil of 9 μm or less is formed thereon by plating. In addition, we are also applying resin.

As another method of manufacturing a copper foil with a resin, for example, a copper foil with a resin composed of a copper foil of 12 μm or more is used, and is thinned by etching to about 5 μm in a manufacturing process of a multilayer wiring board. Has also been done.

[0008]

However, according to the conventional method for producing a resin-coated copper foil, Japanese Patent Application Laid-Open No. 10-146915
In the method disclosed in Japanese Patent Application Laid-Open Publication No. H11-207, since an extremely thin copper layer is formed by plating, there is a problem that thickness variations and minute pinholes cannot be avoided. In addition, since the plating technique is used, a large amount of chemicals is used, and it is necessary to invest a large amount of equipment for waste liquid treatment. Also 12
In the method of etching using copper foil of μm or more, uniform etching is not only technically difficult, but also
The number of extra steps increases, and the cost becomes extremely disadvantageous.

Accordingly, it is an object of the present invention to provide a method for producing a resin-coated copper foil capable of uniformly forming a copper foil having a thickness of 9 μm or less while suppressing an increase in cost.

[0010]

In order to achieve the above object, the present invention superimposes two copper foils and performs cold rolling so that at least one copper foil has a predetermined thickness or less,
A thermosetting resin composition is applied to one surface of the copper foil having a predetermined thickness or less, the thermosetting resin composition is heated to a semi-cured state, and the two copper foils are peeled off and a resin is attached. An object of the present invention is to provide a method for producing a copper foil with resin, which is used to produce a copper foil.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a method for producing a resin-coated copper foil of the present invention will be described in detail.

FIG. 1 shows an apparatus for manufacturing a copper foil with resin according to a first embodiment of the present invention. This manufacturing apparatus is used for the copper foil 2
The supply rolls 1A and 1B for supplying A and 2B and the copper foils 2A and 2B supplied from the supply rolls 1A and 1B are superimposed on each other so that the copper foil 2A has a predetermined thickness, for example, 9 μm or less. A roll 3 for rolling, a coating machine 4 for coating a thermosetting resin composition 5 on one side of a copper foil 2A having a predetermined thickness or less, and a thermosetting resin composition 4 applied to the copper foil 2A Oven 6 which is heated at a predetermined temperature to be in a semi-cured state, and two copper foils 2A and 2B discharged from the drying oven 6 are peeled off and separated into resin-attached copper foil 8A and scrap copper foil 8B. It is provided with a peeling machine 7, a winding roll 9A for winding a copper foil with resin 8A, and a winding roll 9B for winding a copper foil for scrap 8B.

The coating machine 4 includes a coating roll 4a for applying the thermosetting resin composition 5 to one surface of the copper foil 2A, and a supply section 4b for supplying the thermosetting resin composition 5 to the coating roll 4a. ing.

Next, a method for manufacturing a resin-coated copper foil according to the first embodiment of the present invention will be described. First, supply roll 1
A, 1B supplies copper foils 2A, 2B to rolling roll 3,
The copper foils 2A and 2B are overlapped and cold rolled so that the copper foil 2A has a predetermined thickness, for example, 9 μm or less.
Next, the cold-rolled copper foils 2A and 2B are supplied to a coating machine 4, and a varnish-like thermosetting resin composition 4 is coated on one surface of the copper foil 2A having a predetermined thickness or less. Further, the copper foils 2A and 2B coated with the thermosetting resin composition 4 are supplied to the drying furnace 6, and the thermosetting resin composition 4 applied to the copper foil 2A is heated at a predetermined temperature to be semi-cured. State. Thereafter, the thermosetting resin composition 4 peels off the semi-cured copper foils 2A and 2B.
The copper foils 2A and 2B are peeled off and separated into a copper foil with a resin 8A and a copper foil for scrap 8B. 8B is wound up. The copper foil for scrap 8B wound by the winding roll 9B is supplied to scrap for recycling.

In the above embodiment, the copper foil 2B used as a carrier was scrapped for recycling after being peeled off. Both may be a method of using a copper foil with resin. Obviously, this is superior in terms of manufacturing cost. Copper foils 2A and 2B to be stacked before rolling
Rolled copper foil or electrolytic copper foil may be used. In the case of electrolytic copper foil, the surface roughness R is intended to improve the adhesiveness with the resin.
Normally, z is roughened to about 6 μm. However, when this is applied as a material for rolling, an appropriate roughness of Rz of 3 μm or less remains depending on the degree of rolling work, and a good effect on adhesion is obtained. give. In the case of rolled copper foil, the surface is a smooth surface to which the surface of the roll is transferred. If the adhesion is insufficient in this state, use a conventional roughening method such as electrodeposition roughening or shot blasting before applying the resin, or make the surface of the rolling roll an appropriate roughened surface. The surface may be roughened by rolling.

Further, when a polyimide resin is directly applied on the copper foil, the bonding temperature is increased, so that the oxidation of the copper foil progresses and adversely affects the adhesiveness. Therefore, in such a case, the copper foil can be subjected to a single-layer or multi-layer plating of Ni, Zn, Sn or the like, or a chromate treatment in advance. The thermosetting resin composition 5 is not particularly limited, but a resin composition containing an epoxy resin, a polyimide resin, a polyfunctional cyanate compound, or the like is suitable. The coating method is not limited to the method described above, and it may be configured to apply a varnish-shaped resin composition using a curtain coater or the like, or a film-shaped resin composition Coating can be easily performed by laminating using a normal so-called laminator. The coated resin may be completely cured and used for a single-layer wiring board, or it may be used for a multilayer wiring board if it remains in a semi-cured B stage.

According to the method for producing a resin-coated copper foil according to the first embodiment, two copper foils are stacked and rolled to uniformly form a copper foil having a predetermined thickness, for example, 9 μm or less. Can be formed. In other words, copper foil of 9 μm or less is extremely difficult to handle alone because it generates wrinkles and breaks. However, since the copper foil on one side becomes a carrier by overlapping, it is taken directly to the resin coating process. be able to. In the case of rolling, uniformity can be easily maintained by using an X-ray or radiation thickness gauge.

Further, in the two-roll rolling, depending on the heat load conditions at the time of bonding to the two copper foils, the copper foils may adhere to each other to deteriorate the peeling property, or the thinner copper foil may not be peelable. is there. In such a case, a substance for preventing sticking can be interposed.

[0019]

Example 1 Copper foils having a thickness of 100 μm and 15 μm were overlaid, and cold-rolled so that the thickness of the 15 μm copper foil became 5 μm. Next, after degreasing and cleaning the copper foil surface,
A thermosetting resin composition (for example, an interlayer insulating material TBR-27 manufactured by Tamura Seisakusho Co., Ltd.) is applied by a roll coater to a copper foil side having a thickness of 5 μm to a thickness of 70 μm in a wet state.
The solvent component was volatilized and dried in a heating and drying oven at 0 ° C. Finally, the superposed copper foil was peeled off to obtain a resin-coated copper foil on which a copper foil having a thickness of 5 μm was formed. On the other hand, the other stripped copper foil was used as scrap for recycling. The obtained resin-coated copper foil is an FR-4 substrate on which a predetermined circuit is formed on both sides,
The resin-coated copper foil was overlaid on both sides such that the resin surface was in contact with the substrate circuit surface, and hot-pressed at a pressure of 1 kg / cm ² and a temperature of 180 ° C. for 1 hour to obtain a multilayer wiring board.

[0020]

Example 2 Two copper foils each having a thickness of 15 μm were overlapped and cold-rolled so that each copper foil became 7 μm. After the surface was degreased and cleaned, a thermosetting resin composition (for example, an interlayer insulating material TBR-27 manufactured by Tamura Corporation) was applied to both surfaces by a roll coater. Each coating thickness is we
The solvent component was evaporated and dried in a drying oven at 120 ° C. to obtain a resin-coated copper foil having a 7 μm-thick copper foil. Next, after the laminated copper foil was peeled off, each of the resin-coated copper foils was laminated on an FR-4 substrate in the same manner as in Example 1 to obtain a multilayer wiring board.

[0021]

As described above, according to the method for producing a resin-attached copper foil of the present invention, two copper foils are overlapped and cold-rolled so that at least one side of the copper foil has a predetermined thickness or less. After applying, a thermosetting resin composition is applied to one surface of a copper foil having a predetermined thickness or less, and after heating, the two copper foils are peeled off to produce a resin-coated copper foil, thereby increasing cost. And a copper foil having a thickness of 9 μm or less can be uniformly formed.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an apparatus for producing a resin-attached copper foil according to a first embodiment of the present invention.

[Explanation of symbols]

 1A, 1B Supply roll 2A, 2B Copper foil 3 Rolling roll 4 Coating machine 4a Coating roll 4b Supply unit 5 Thermosetting resin composition 6 Drying furnace 7 Peeling machine 8A Copper foil with resin 8B Copper foil for scrap 9A, 9B Take-up roll

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Noboru Hagiwara 5-1-1, Hidaka-cho, Hitachi City, Ibaraki Prefecture F-term in Hitachi Cable, Ltd. General Research Laboratory 4F100 AB17A AK01B AK49B BA02 BA10A BA10B CC00B EH461 EJ421 EJ912 GB43 JB13B JL02 5E346 AA12 AA15 AA32 CC02 CC08 CC09 CC10 CC12 CC32 DD02 DD03 DD12 EE01 GG02 HH24 HH31

Claims (5)

[Claims] 1. A method of laminating two copper foils, performing cold rolling such that at least one of the copper foils has a predetermined thickness or less. Applying a resin composition, heating the thermosetting resin composition to a semi-cured state, and peeling off the two copper foils to produce a resin-coated copper foil, Production method 2. The step of performing the cold rolling comprises:
The step of cold rolling the one copper foil so that one copper foil of the one copper foil has a predetermined thickness or less, the step of applying the thermosetting resin composition, 1
A step of applying the thermosetting resin composition to one surface of one piece of copper foil, the step of producing the copper foil with a resin produces one copper foil with a resin, and the other copper foil The method for producing a copper foil with resin according to claim 1, comprising a step of scrapping. 3. The method for producing a resin-coated copper foil according to claim 2, wherein the step of performing the cold rolling is performed by setting the predetermined thickness to 9 μm. 4. The step of performing the cold rolling includes:
The step of cold rolling the copper foil so as to have a predetermined thickness or less; and the step of applying the thermosetting resin composition,
2. The step of applying the thermosetting resin composition to one surface of each of the copper foils, and the step of manufacturing the resin-coated copper foil includes the step of manufacturing two resin-coated copper foils. The method for producing a copper foil with resin according to the above. 5. The method for producing a resin-coated copper foil according to claim 4, wherein the step of performing the cold rolling is performed by setting the predetermined thickness to 9 μm.