JPH0575252A - Manufacture of film with metallic layers on both sides - Google Patents

Abstract

PURPOSE:To prevent the mutual bonding of metallic layers without using a spacer when a film with metallic layers on both sides is manufactured through a winding system. CONSTITUTION:Metallic layers are formed on both surfaces of a film through an evaporation method (resistance heating evaporation, EB evaporation, sputtering, etc.) (evaporation may be conducted for every surface, or may be performed simultaneously on both surface) while winding an insulating film. An oxide film layer is formed on the surface of at least one metallic layer before the film under the state in which the metallic layers are formed on both surfaces is wound at that time. The oxide film is shaped easily by passing a metal-sputtered film in the open air or in an oxygen-rich atmosphere.

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 double-sided metal-layered film used for a flexible printed wiring board or a carrier tape for TAB (Tape automated bonding).

[0002]

2. Description of the Related Art There are roughly two methods for producing a raw material of a film with a metal layer used for a flexible printed wiring board or a TAB tape. one,
A method is to bond an insulating film made of polyimide or the like and a copper foil (metal layer) with an adhesive, and another method is to provide a metal layer on the insulating film without using an adhesive.
Generally, the three-layer stock produced by the former method,
The one produced by the latter method is called a two-layer original fabric.

The method for producing a two-layer original fabric further includes a method in which a thin metal layer is formed on the insulating film by a method such as vapor deposition or electroless plating, and then a thick film is formed by electrolytic plating. And a method of forming an insulating film by applying polyimide varnish or the like on the metal layer.

By the way, in recent years, among TAB tapes,
A TAB tape having a structure having metal layers on both sides of an insulating film, such as a GTAB (TAB with ground) and a 2CTAB (2 conductor TAB), has high-speed response,
Attention has been paid to noise resistance and other aspects. As a film with a metal layer used for such an application, a two-layer web without an adhesive layer is superior to a three-layer web in terms of electrical characteristics.
It is required to establish a method for efficiently producing a two-layer original fabric in which metal layers are directly formed on both sides of an insulating film.

As described above, there are various methods for producing a two-layer original fabric, but a dry method such as vapor deposition is used rather than a method of forming a metal layer by a wet method such as electroless plating. When the metal layer is formed, the adhesion between the metal layer and the insulating film is better. Specific methods of vapor deposition (generally referred to as vapor deposition in the present specification are methods of physically scattering substances to be deposited to form a thin film) are resistance heating vapor deposition, EB (electron beam) vapor deposition, Although there are various methods such as sputtering, the method by sputtering is particularly excellent in adhesion.

In order to continuously produce the above-mentioned two-layer original fabric, it is usual to carry out by a winding method. When depositing the metal layers on both sides of the roll film, it is conceivable to deposit on both sides at the same time, or to deposit on both sides separately in two times. Often done.

[0007]

However, the above-mentioned conventional method for producing a film with a double-sided metal layer has the following problems. When forming a metal layer on each side of the insulating film, the metal layer is formed on the other side after the completion of one side.In the winding method, the newly formed metal layer is formed first. The insulating film is wound up in contact with the metal layers one after another. At this time,
Since the surface of the metal layer formed by a dry method such as vapor deposition is clean and active, the metal layers (deposition surfaces) adhere to each other frequently. In the case of a very large amount, if the film is rewound and peeled off, the insulating film itself is destroyed, and even if it is not reached to that extent, the surface of the metal layer is damaged to cause a defect in the metal layer, which causes a defect. Such a phenomenon is more remarkable when the metal layers are simultaneously formed on both surfaces and wound.

In order to prevent the metal layers from adhering to each other as described above, it is necessary to wind the insulating film such as PET (polyethylene terephthalate) or the like while sandwiching it as a spacer. For that purpose, the spacer is unwound and wound up. Must be provided in the vapor deposition device. as a result,
There is a problem that the device becomes large and that the wound web also becomes large and heavy by the amount of the spacer. Further, even at the stage of processing the obtained original fabric, an extra mechanism for winding the spacer is required, and the production efficiency of the TAB tape or the like is reduced.

The present invention has been made in view of the above points, and is a method of preventing the adhesion of metal layers to each other without using a spacer when a double-sided metal layer-attached insulating film is manufactured by a continuous winding method. It is intended to provide.

[0010]

According to the present invention, a method for producing a film with a double-sided metal layer by forming metal layers on both sides of an insulating film by a winding method, a state in which metal layers are formed on both sides The problem described above is achieved by performing a process of providing an oxide film layer on the surface of at least one of the metal layers before winding the insulating film.

Specifically, the formation of the metal layer in the present invention is not limited to a dry method (a method such as vacuum deposition or sputtering in which a substance is physically scattered to form a thin film).
It is performed by a method such as CVD in which a film is deposited by a chemical reaction, or a method by a combination of physical means and chemical means), and one side or both sides are formed simultaneously. The oxide film may be formed before winding the insulating film with the metal layers formed on both sides, at a stage where the metal layer is formed on only one side, or after forming the metal layers on both sides. May be.

[0012]

[Function] The metal layer is formed by the dry method, for example, in the vapor deposition method, the atoms of the substance to be deposited are scattered in a vacuum or an inert gas by heat or ion collision, and the scattered atoms are deposited on the surface of the insulating film. Since it is done by deposition, the surface of the metal layer immediately after formation is very clean and active.

On the other hand, it can be said that the metal oxide film is inactive. In the present invention, an oxide film is provided on at least one surface of the metal layer before winding the insulating film with the metal layers formed on both sides, so that adhesion of the metal layers during winding is prevented. It Adhesion during winding is
This occurs when both surfaces in contact with each other are clean and active. Therefore, if an oxide film is provided on one surface, the metal layers do not adhere to each other even if the other surface is a vapor deposition surface that is still active.

The oxide film provided to prevent adhesion in the present invention can be formed by simply exposing the metal surface to the atmosphere or the like, so that it is not necessary to install new equipment unlike the case of using a spacer. The inconvenience of increased weight and size does not occur. Further, the metal layer provided with the oxide film can be subjected to a treatment such as etching under the same conditions as the metal layer not provided with the oxide film, and does not become an obstacle at the time of pattern formation.

[0015]

The following is a description of the case where the present invention is applied to the production of a film with a double-sided metal layer for a TAB tape. Example 1 Polyimide film (manufactured by Toray DuPont, KAPTO
N 200H, 165 mm width, 50 m length) was wound on a core having a diameter of 8 inches (about 20 cm) and mounted on a winding type magnetron sputtering device (manufactured by East Japan ULVAC, Inc.). This film was also wound on a core having a diameter of 8 inches, and copper was sputtered on one surface of the film. The linear velocity of the film was 0.25 m / min, and the copper film thickness was 0.2 μm under these conditions.

Next, the vacuum in the sputtering tank was broken and the atmosphere was introduced. In this atmosphere, after the sputtering, the film wound on the core was rewound at a speed of 2.5 m / min to spontaneously oxidize the sputter surface to form an oxide film layer. After that, the core in which the film was rewound was replaced with a sputtering device, and copper was sputtered on the back surface while winding the film, but no adhesion was observed between the sputtered copper surfaces.

Example 2: 2 When copper was sputtered on one side of a film in the same manner as in Example 1, an oxygen-rich region was provided after the sputtering region in the apparatus, and the film immediately after copper was sputtered was oxygen-rich. It was wound on a core while being oxidized through the area. The oxygen flow rate in the oxygen rich region is 100 scc
m. Then, as in Example 1, the core wound with the film was replaced with a sputtering device and copper was sputtered on the other surface. Also in Example 2, no adhesion between the sputtered copper surfaces was observed.

Example 3: 3 In this example, the sputtering apparatus provided with the oxygen-rich region of Example 2 was used, but unlike Example 2, the oxygen-rich region was not taken up during the first copper sputtering. (At this time, it is the film surface that is in contact with the sputtered copper surface so that no adhesion occurs.) The film immediately after the second copper sputtering was passed through the oxygen rich region. Also in this case, no adhesion was observed between the sputtered copper surfaces.

Comparative Example 1 Copper was sputtered on both sides of a polyimide film in the same manner as in Example 1. However, in Example 1, the rewinding in the atmosphere after the first copper sputtering was not performed. When the film was rewound after the copper spattering on both the front and back sides was completed, part of the sputtered copper surface was peeled off due to adhesion,
The underlying polyimide film has been exposed. In particular, the film was torn at the part where the adhesion was severe.

[0020]

As described above, in the present invention, at the time of producing a film with a double-sided metal layer by a winding method, at least one metal layer is formed before winding the film having the metal layers formed on both sides. Since the oxide film layer is provided on the surface, it is possible to prevent the metal layers from adhering to each other without using a spacer. That is, extra equipment and processes for winding up and unwinding the spacers are not required, which makes it possible to reduce the cost and simplify the process, and also to increase the size and weight of the roll film. Will be resolved.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Eiichi Taguchi 2-6-1, Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd. (72) Kenichi Otani 2-6-1, Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd.

Claims (1)

[Claims] 1. A method for producing a film with a double-sided metal layer by forming metal layers on both sides of an insulating film by a winding method, wherein the insulating film having the metal layers formed on both sides is wound up. A method for producing a film with a double-sided metal layer, which comprises first performing a treatment of providing an oxide film layer on the surface of at least one of the metal layers.