JPS63182149A - Manufacture of foil-clad metallic plate - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to an advantageous method for manufacturing foil laminated metal sheets.

[Prior art]

Conventionally, this type of foil-laminated metal plate is produced by, for example, applying an adhesive to a copper foil, or in the case of an insulating film, applying an adhesive to an insulating film, then laminating the copper foil, and then applying a film. After applying an adhesive to the opposite side of the metal plate, the metal plate is placed on the metal plate via the adhesive, and the adhesive is heated and pressed using a press to harden and bond the metal plate. However, this method had the following drawbacks.

■ Since the adhesive is degassed by flowing, it is difficult to control the adhesive thickness, and it is also difficult to apply uniform pressure to the entire surface, which may impair the uniformity of the thickness.

■ When there is a large difference in the coefficient of thermal expansion between foil and metal plate, for example, in the case of copper foil and aluminum plate, the aluminum plate has a larger coefficient of thermal expansion than copper, so when heating the foil-bonded metal plate, the aluminum plate There is a large elongation, and it warps toward the copper foil side. However, when manufacturing with a press, it is flat because it is pressed by the smooth surfaces of the upper and lower plates during heating. For this reason, when the aluminum plate is removed from the press and cooled, the aluminum plate shrinks significantly, causing it to warp toward the aluminum plate side.

■ In the case of pressing, multiple sheets can be made at once using a multistage press, but even then, productivity is low because heating and pressure must be applied within the curing time of the adhesive.

(2) When inserting an insulating film into the insulating layer, the adhesive layer sandwiching the insulating film flows when heated and pressurized, which tends to cause wrinkles in the film.

[Purpose of the invention]

The present invention has been made in order to eliminate such drawbacks, and an object of the present invention is to provide an advantageous manufacturing method for a foil-bonded metal plate. [Structure of the Invention] Therefore, the present invention Abstract: A method for producing a foil laminated metal plate, which is characterized by hot roll laminating a foil or synthetic resin film-foil laminate onto a metal plate via an adhesive layer, and then pressurizing and heating in an autoclave. That is.

Hereinafter, the configuration of the present invention will be explained in detail.

The foil used in the present invention is a conductive foil that is ultimately etched to form a circuit, and is generally copper foil, aluminum foil, or the like.

A synthetic resin film-foil laminate is obtained by laminating a synthetic resin film on the above-mentioned foil via an adhesive or by heat setting. As the synthetic resin film, highly insulating films such as polyimide film, polyester film, polyether sulfone film, polyether ketone film, and polyparabanic acid film are generally used.

As the metal plate, aluminum plate, iron plate, silicon steel plate, etc. are generally used.

As the adhesive, epoxy, acrylic, and other heat-curable adhesives are generally used. Adhesives can be applied as solvent-based or solvent-free adhesives, but in many cases a thin coating thickness of a few microns to several hundred microns is required to be uniform.
It is desirable that the viscosity at the time of application is low. In addition to coating, a film adhesive can also be used.

(1) In the present invention, first, a foil or a synthetic resin film-foil laminate is hot roll laminated to a metal plate via an adhesive layer.

When bonding a laminated foil having an adhesive/foil or adhesive/film/adhesive/foil structure to a metal plate via an adhesive layer, it is first necessary to prevent air bubbles from entering. In the case of a press, the press surface is flat, so if the adhesive is sticky and the surrounding area becomes sticky before applying pressure, the adhesive will flow during pressurization and heating and will not accumulate inside. However, using methods other than pressing, it is difficult to bond without bubbles. As a result of various studies, the present inventors found that hot roll lamination allows degassing, bonding, and temporary attachment.

Here, hot roll lamination refers to bringing the foil side of a laminated foil having a structure of adhesive/foil or adhesive/film/adhesive/foil into contact with a heated roll.

This reduces the viscosity of the adhesive, increases its adhesive strength, and improves its wettability to the metal plate. Desirably, the preheated metal plate and the heated laminated foil are bonded together while being pressed with an adhesive using a roll.

The roll can be a rubber roll or a metal roll.

The heating conditions for the roll depend on the viscosity and tackiness of the adhesive, but the surface temperature is 50°C or higher, preferably 70°C or higher. In the case of so-called hot-melt adhesives that are not sticky at room temperature but become sticky at high temperatures, the temperature should be further increased to 90°C.
The above is desirable. Since the adhesive is heat-curable, it will cause a slight reaction just by passing it through a heated roll, but while it may be sufficient for temporary adhesion, it is completely insufficient for adhesion.
It needs to be heated and hardened.

(2) Next, in the present invention, the thus hot roll laminated product is pressurized and heated in an autoclave.

As a result of various studies in order to obtain a uniform pressure distribution, the method of heating and curing to develop adhesive strength was determined by heating, pressing and curing with high-pressure heated gas in an autoclave.
I learned that it is possible to solve various problems that have arisen in presses. That is, since the high-pressure gas uniformly presses the foil surface against the metal plate, no flow of the adhesive occurs, and the coating thickness remains as the thickness of the adhesive layer. In terms of coating thickness, current coating technology allows for very uniform coating and easy control of the coating thickness. Therefore, the uniformity of the adhesive layer and the ease of adjusting the thickness are much better than in the case of pressing.

Recently, adhesives have also been cured in autoclaves, but in this case, a vacuum method is used for degassing, followed by pressure and heating. In this case, since a vacuum method is used, the surface of the object to be cured is restrained in some way. For example, it is sandwiched between a metal plate and a heat-resistant film (polyester film, nylon film, etc.), or it is sandwiched between a rubber sheet and evacuated.

If this method is used, the adhesive layer will not be subjected to uniform pressure on the surface of the object due to its restraint, and for example, the adhesive at the edges will flow and come out of the adherend. In some cases, the material is inconvenient enough to have to be brought into a semi-cured state before the curing process in order to prevent the flow. Therefore, these systems are essentially different from the present invention in that they are not subjected to uniform pressure.

Foil and metal plates are usually made of different materials, but different materials naturally have different coefficients of thermal expansion, and the laminated plates bonded together warp when heated. In the autoclave, the temporarily attached foil bonded plate is not restrained in any way, so it warps, but when it cools down and returns to room temperature, the warp disappears.

Furthermore, in the case of a laminate with a foil/adhesive/film/adhesive/metal plate structure, the film is pressed evenly with gas, so there is no flow of the adhesive, so the film may wrinkle. Never. In terms of productivity, there are also multi-stage presses, but they have limited production capacity. In the case of the present invention, in hot roll lamination where temporary bonding is performed, adhesive/foil or adhesive/film/adhesive/
The tubes can be produced in rolls and successively bonded to aluminum plates.

Even if the aluminum plate is cut into an appropriate size in advance, small pieces can be continuously flowed to attach a roll-shaped laminated foil to the aluminum plate.

The foil-bonded metal plates that have been continuously temporarily attached are cut into appropriate sizes. Alternatively, it is also possible to use a device that automatically cuts the laminated foil coated with adhesive to the same size as the pre-cut aluminum plate just before it is temporarily attached.

A large number of cut foil-bonded metal plates can be placed in the autoclave. For example, when loading the foil onto a rack and putting it into an autoclave, if you only pay attention to the loading so that the foil side does not come into contact with other foil laminated metal plates, it is possible to load the foil with a space, for example, in+. Since it is possible, let's say 50cm x 50cm x
50cm volume, area 50cmX50cm, 1.5
This is a set of 200 foil-bonded metal plates with a thickness of 11 mm, which can be cured all at once. No other method has been found that enables continuous bonding and curing of multiple areas at once.

An inert gas can be used as the gas pressurized within the autoclave. Surface oxidation of copper foil or aluminum foil heated to high temperatures is promoted by contact with air, but oxidation can be prevented by using an inert gas, such as inexpensive nitrogen gas.

The pressure when pressurizing and heating in the autoclave is 1 to 1.
0 kg/ad is suitable, and the heating temperature varies depending on the type of adhesive, but generally 50°C to 250°C is suitable.

Examples are shown below.

Example (a) Preparation of adhesive/foil.

Apply epoxy adhesive (solid content 50%) dissolved in methyl ethyl ketone to the surface treated surface of rolled copper foil (one side surface treated product, width 520 mm, thickness 35 μm).
Coat with a comma coater at m and dry in a hot air drying oven at 80℃ for 5
The copper foil with a 40 μm thick adhesive layer was continuously produced in roll form by passing for 1 minute and drying the solvent. In order to prevent the adhesive and the copper foil from coming into close contact, after the adhesive had dried, release paper was added to form a roll.

(bl　Preparation of adhesive/film/adhesive/foil.

First, on one side of a film (polyimide film, 25 μm thick, 508 m wide), the adhesive was similarly applied to a width of 500 μm and a thickness of 20 μm, and dried in the same way to a thickness of 10 μm.
A sheet with an adhesive layer of μm was obtained. Immediately before winding the film into a roll, a release paper was laminated on the surface of the adhesive layer to prevent the film from coming into close contact with the adhesive layer, and the film was formed into a roll.

Next, adhesive was applied to the non-glossy surface of copper foil (electrolytic copper foil, width 520 mm, thickness 35 μ) with a width of 500 mm and thickness of 20 μ, and dried in the same manner to form an adhesive layer with a thickness of 10 μ. This copper foil was laminated continuously with the non-adhesive film surface of the previously produced sheet having an adhesive layer, and then wound into a roll.

For this laminate, a linear pressure of 2. Okg/c
Hot roll lamination was performed at a pressure of +n. In this way, a laminated foil having a structure of adhesive/foil or adhesive/film/adhesive/foil was obtained. There are many manufacturing methods for manufacturing such a structure in addition to the methods described above.

(C1 Next, the aluminum plate (thickness 1.0mm, 500u+
The laminated foil produced above was attached to one side of a 500 ml sample under the following conditions.

That is, the rolled laminated foil was rolled up, and while the release paper was rolled up and peeled off with a roll, the adhesive layer was placed on the aluminum plate side, and the copper foil side was placed on a heated metal roll (surface temperature: 100°C). , and a heated rubber roll (surface temperature 100°C).

The aluminum plates were inserted between the laminated foil and the heated rubber roll, and the aluminum plates were passed one after another with an interval of about several 1 ml, which allowed the insertion of a cutter knife. At this time, if the interval between the aluminum plates is too wide, the adhesive layer of the laminated foil will come into contact with the heated rubber roll, which is not preferable because the adhesive will adhere to the surface of the rubber roll. If you wish to widen the interval for any reason,
You can insert release paper, release film, etc. under the aluminum plate. Linear pressure between rolls is 3 kg/c
I went with m.

In this way, the copper clad plate that was continuously hot roll laminated was cut into laminated foil to match the size of the aluminum plate. The obtained copper clad board had a very smooth surface.

(d) When placing the adhesive in an autoclave with an inner diameter of 75 cm and a depth of 60 CI11 to cure the adhesive,
Create a rack with internal dimensions of 505 dragons x 505 cranes and a depth of 505 mm that can support only both ends of a 0 cm x 50 cm aluminum plate, and leave a 1.5 m space in the rack.
．． One copper clad plate was inserted for every 5**, making a total of 200 copper clad plates.

Place this rack in an autoclave, fill it with nitrogen, raise the pressure cuff to kg/cd in 10 minutes, then raise the temperature from room temperature to 200 °C in 20 minutes, and leave it for 1 hour.
It was held for 0 minutes and then cooled for 20 minutes.

Inside the autoclave, the entire copper clad plate is pressurized with uniform pressure, so unlike when the surface of the copper clad plate is in contact with some object and pressurized, the adhesive does not flow. A uniform thickness could be maintained due to continuous coating. Also, no warping of the copper clad plate was observed.

Even when a polyimide film is inserted, the thickness of the adhesive layer on both sides of the polyimide film is uniform.
Even if the combined thickness of the adhesive is the same, the adhesive on the copper foil side or the aluminum plate side may flow depending on the location, resulting in a difference of 1 part of the thickness.
No wrinkles were observed in the polyimide film, which occurs when one side becomes thicker or thinner.

Furthermore, since the copper foil was not brought into contact with air at the same temperature, no oxidation was observed on the surface, and the initial surface condition of the copper foil was maintained.

〔Effect of the invention〕

As explained above, according to the present invention, the following effects can be achieved because the method of hontrol lamination and subsequent pressurization and heating in an autoclave is used.

- Since the adhesive does not flow, a uniform adhesive layer can be obtained, and the thickness of the layer can be easily adjusted.

■ The sled does not start.

■ High productivity.

■ When the film is inserted into the adhesive layer, there will be no wrinkles in the film.

■ The surface of the foil is often oxidized.

Claims (1)

[Claims] A method for producing a foil laminated metal plate, which comprises hot roll laminating a foil or synthetic resin film-foil laminate onto a metal plate via an adhesive layer, and then applying pressure and heating in an autoclave.