JP2003001754A - Method for manufacturing flexible laminated sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a flexible laminated sheet not having appearance defectiveness such as wrinkles or the like generated at the time of hot lamination. SOLUTION: In the method for manufacturing the flexible laminated sheet by continuously laminating an adhesive film containing 50 wt.% or more of a thermoplastic polyimide in its adhesive component and a metal material comprising a copper foil with a thickness of 50 μm or less using a hot roll laminator, the adhesive film is stretched in a width direction (TD direction) immediately before lamination in a stretching ratio of 100.05-100.50%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a laminated board manufactured by a pressure heating molding apparatus, and more particularly to a method for manufacturing a flexible laminated board used in electronic and electrical equipment.

[0002]

2. Description of the Related Art A laminated board used for a printed circuit board for electronic and electrical equipment is a laminated board to which a metal foil is attached by a thermosetting adhesive such as a thermosetting resin (hereinafter referred to as a thermosetting laminated board. And a laminated plate adhered by a heat-fusion adhesive such as a thermoplastic resin (hereinafter referred to as a heat-fusion type laminated plate). A thermosetting laminate is formed by forming a thermosetting adhesive such as epoxy resin or acrylic resin on both sides of a heat resistant film such as a polyimide film, bonding it with a metal foil, and then curing it for a long time to cure it. Completed and created.
In recent years, due to environmental issues, lead-free solder, which has a higher temperature than the conventional melting point, has been used as a solder material, and with it, the heat resistance required for flexible laminated boards has become more severe. However, it has become difficult to satisfy heat resistance with acrylic resins.

In order to meet the demand for heat resistance, a heat-fusion type laminated plate using a thermoplastic polyimide resin as an adhesive layer is used. To manufacture a heat-fusion type laminated plate, apply a polyimide resin on one side of a metal material and dry it, or apply a polyimide precursor solution, dry and cure it, and stick it with a laminating device with the adhesive surfaces facing each other. A method of manufacturing a flexible laminated plate on both sides together, or a polyimide resin is applied and dried on both sides of a heat-resistant film such as a polyimide film, or a polyimide precursor solution is applied, dried, and cured to prepare an adhesive film, copper There is a method of manufacturing a flexible laminated plate on both sides by laminating with a laminating device with a structure of foil / adhesive film / copper foil.

In the case of producing a heat fusion type laminate, heat fusion cannot be performed unless pressure and heating are performed at a temperature higher than the glass transition temperature (Tg) of the thermoplastic resin constituting the adhesive layer. On the other hand, since the laminated plate for electronic and electrical equipment is heated at a high temperature in the process of mounting components, the thermoplastic resin forming the adhesive layer is required to have Tg of 180 ° C. or higher. Further, a thermal laminating temperature of 200 ° C. or higher is required for the heat fusion. In such a high temperature lamination, there is a problem that a change in thermal expansion / contraction of the material to be laminated is large, and the laminated body is likely to have a defective appearance such as wrinkles.

Immediately before being laminated, the adhesive film is applied with a certain amount of tension so that the film fed from the feeding shaft does not meander, and therefore a force for stretching the film is applied in the laminating direction (MD direction) of the adhesive film. However, in the width direction (TD direction) of the adhesive film, a force to shrink in the TD direction acts according to the extension of the adhesive film pulled in the MD direction due to the free state without any force. Due to the force of shrinking in the TD direction, the dimensional change of the laminated flexible laminate after etching in the TD direction becomes large,
There was a problem that wrinkles occurred.

[0006]

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a method for producing a laminated board suitable as a flexible substrate material which does not have a defective appearance such as wrinkles that occur during thermal lamination.

[0007]

The inventors of the present invention suppress the shrinkage in the TD direction and suppress the dimensional change after etching by forcibly stretching the adhesive film in the TD direction immediately before lamination in the same system as described above. The inventors of the present invention have found that the size is reduced and wrinkles that occur during lamination are reduced, and the present invention has been achieved. That is, the present invention is a method for producing a laminated plate in which an adhesive film and a metal material are continuously laminated by a hot roll laminating apparatus, wherein the adhesive film is stretched in the width direction immediately before lamination. It is a method of manufacturing a laminated board, and has a stretch ratio in the width direction of 1
It is preferably 00.05 to 100.50%.

The adhesive film is preferably an adhesive film containing 50% by weight or more of thermoplastic polyimide in the adhesive component, and the metal material is preferably a copper foil having a thickness of 50 μm or less.

[0009]

DETAILED DESCRIPTION OF THE INVENTION The details of the present invention will be described below. The use of the laminate obtained by the production method of the present invention is not particularly limited, but it is mainly used as a flexible laminate for electronic and electrical applications.

As the adhesive film, a single-layer film made of a resin having a heat-sealing property, or a multi-layer film formed by forming a resin layer having a heat-sealing property on both sides of a core layer having no heat-sealing property , A film made by impregnating a base material such as paper or glass cloth with a resin having a heat-sealing property is used, but when a rigid base material such as glass cloth is used, the flexibility is poor. As the adhesive film of
A single-layer film made of a resin having a heat-fusion property and a multi-layer film formed by forming a resin layer having a heat-fusion property on both sides of a core layer having no heat-fusion property are preferable. A single-layer film made of a resin having a heat-fusible property, a multi-layer film formed by forming a resin layer having a heat-fusible property on both sides of a core layer having no heat-fusible property has heat resistance. Preferably, an adhesive component composed of a thermoplastic polyimide-based component, for example, a thermoplastic polyamideimide, a thermoplastic polyetherimide, a thermoplastic polyesterimide or the like can be suitably used. An adhesive film containing 50% or more of these heat-resistant thermoplastic resins in the adhesive component is also preferably used in the present invention, and an adhesive film containing a thermosetting resin such as an epoxy resin or an acrylic resin may be used. preferable. Various additives may be added to the adhesive film in order to improve various properties.

The structure of the adhesive film may be a single layer composed of only a heat-fusible adhesive component as long as it has a heat-resistant adhesive layer on the outer side, but from the viewpoint of dimensional characteristics and the like, the heat-bonding is possible. A film having a three-layer structure having a heat-fusible adhesive layer on both sides of a core layer having no property is preferable. The core layer having no heat fusion property is not particularly limited as long as it has heat resistance, but it is preferable to use a non-thermoplastic polyimide film.

The method for producing the adhesive film is not particularly limited, but when the adhesive film is composed of a single layer, it can be formed by a belt casting method, an extrusion method or the like. In addition, when the structure of the adhesive film is composed of three layers of an adhesive layer / a core layer having no heat fusion property / an adhesive layer, it is formed on both surfaces of the core layer having no heat fusion property (for example, a heat resistant film). Glue
A method of preparing a three-layer adhesive film by applying each side or both sides simultaneously, or a method of preparing a three-layer adhesive film by arranging and bonding a single-layer adhesive film consisting of an adhesive component on both sides of a heat resistant film There is a way to do it. In a method of applying an adhesive to produce a three-layer adhesive film,
Especially when using a polyimide-based adhesive, there is a method of applying a heat-resistant film in the state of polyamic acid, then performing imidization while drying, and a method of applying a soluble polyimide resin as it is and drying it. The method for forming the layer is not particularly limited. In addition, there is also a method of co-extruding each resin of the adhesive layer / core layer not having heat-resistant fusion resistance / adhesive layer to form an adhesive film at one time.

The metal material is not particularly limited, but in the case of a laminated plate used for electronic and electrical equipment, it is preferable to use copper foil from the viewpoint of conductivity and cost. Regarding the thickness of the metal foil, the thinner the copper foil, the finer the line width of the circuit pattern. Therefore, the copper foil is preferably 50 μm or less. In particular, since a copper foil having a thickness of 35 μm or less is less stiff than a copper foil having a thickness greater than that, and wrinkles are likely to occur during thermal lamination, the present invention exerts a remarkable effect on a copper foil having a thickness of 35 μm or less. The type of copper foil includes rolled copper foil, electrolytic copper foil, HTE copper foil and the like, and there is no particular limitation, and an adhesive may be applied to the surface of these.

The hot roll laminating apparatus is not particularly limited as long as it is an apparatus for heating the material to be laminated and applying pressure thereto. Regarding the heating method, as long as it can be heated at a predetermined temperature, it is not particularly limited,
A heating medium circulation system, a hot air heating system, a dielectric heating system, etc. are mentioned. The heating temperature is preferably 200 ° C. or higher, but when the laminated plate is used for the purpose of passing through a solder reflow furnace having an ambient temperature of 240 ° C. for mounting electronic parts, a heat-sealing sheet having a Tg corresponding to that is used. For use, heating at 240 ° C. or higher is preferable. The material of the press roll is not particularly limited, such as rubber and metal, but the rubber roll cannot be used at a high lamination temperature of 280 ° C. or higher and cannot be used, and a metal roll is preferable. The pressurizing method is not particularly limited as long as a predetermined pressure can be applied, and a hydraulic method, an air pressure method, a gap pressure method and the like can be mentioned, and the pressure is not particularly limited.

The mechanism for stretching the adhesive film in the TD direction is not particularly limited as long as it satisfies the requirement that the adhesive film is stretched in the TD direction. For example, a mechanism such as a pinch roller, an aspender roller, a banana roll, or a ribbon roll can be installed to stretch the adhesive film in the TD direction.

In the present invention, the object can be achieved by stretching the adhesive film in the TD direction immediately before laminating, but the stretching ratio in the TD direction is 10
It is preferably in the range of 0.05 to 100.50%.

The protective material may be any as long as it can protect the laminated product from appearance defects such as wrinkles. However, it must be able to withstand the temperature at the time of processing, and for example, when processing at 250 ° C., a polyimide film having heat resistance higher than that is effective. The thickness of the protective material is not particularly limited, but a thickness of 50 μm or more is preferable for the purpose of suppressing wrinkle formation of the laminated plate after lamination. If the thickness of the protective material is 75 μm or more, wrinkle formation can be suppressed almost completely, which is more preferable. In addition, the protective material does not need to be surface-treated as long as it is in close contact with the laminated material. On the contrary, if the protective material is one that does not adhere to the laminated material, surface treatment should be performed so that it adheres lightly to the protective material side, or similar surface treatment to the copper foil side. It may be surface-treated. In addition, even if the surface treatment is performed for other purposes, such as rust-prevention treatment for the purpose of preventing the oxidation of the copper foil surface, as long as the protective material and the laminated material are in close contact with each other, the surface It may be treated.

The temperature of the laminated plate when peeling off the protective material is
When a thermoplastic resin is used as the material to be laminated, a temperature below its Tg is preferable. More preferably, the temperature is 50 ° C. or more lower than Tg, and even more preferably 10 ° C. lower than Tg.
It is a temperature lower than 0 ° C. Most preferably, the protective material is peeled off from the laminate when cooled to room temperature. Hereinafter, the present invention will be described in more detail with reference to examples.

[0019]

EXAMPLES The present invention will be described in detail with reference to Examples and Comparative Examples of the present invention, but the present invention is not limited to these Examples. Hereinafter, in Examples and Comparative Examples, the physical properties of the adhesive layer and the physical properties of the flexible substrate were measured as follows.

(Dimensional change rate) Based on JIS-C6481, the distance of each of the four holes formed on the double-sided board was measured, and then the copper foil was removed by etching, and then at 20 ° C.
The sample was allowed to stand in a thermostatic chamber at 60% RH for 24 hours, and the distances of the four holes were measured in the same manner as before etching to obtain the dimensional change rate after etching by the following formula. Dimensional change rate (%) = [(measured value of film after etching−measured value before etching) / (measured value before etching)] × 100 (Example 1) Heat-resistant adhesive film (manufactured by Kanegafuchi Chemical Industry) Two
A metal material (18 μm rolled copper foil BHY-22B-T made by Japan Energy) is placed on both sides of a 5 μm thick PIXEO BP HT-142),
Further, with a protective material (apical 125AH manufactured by Kanegafuchi Chemical Industry Co., Ltd.) disposed on both sides thereof, a pinch roller was installed as shown in FIG.
In a 10% stretched state, lamination was performed by a hot roll laminating apparatus under the conditions of a laminating temperature of 300 ° C., a laminating pressure of 50 N / mm and a laminating speed of 1.0 m / min to obtain a flexible laminated plate. As a result, a flexible laminate without wrinkles was obtained. The dimensional change rate after etching is MD-0.05,
It was TD + 0.02.

(Example 2) Immediately before laminating, an expander roller as shown in FIG.
Lamination was performed under the same conditions as in Example 1 except that the film was stretched by 100.20% in the D direction. As a result, a flexible laminate without wrinkles was obtained. The dimensional change rates after etching were MD-0.03 and TD + 0.03.

Example 3 Example 1 was repeated except that a banana roll was placed on the pass line as shown in FIG. 4 immediately before laminating to stretch the adhesive film 100.30% in the TD direction.
Lamination was performed under the same conditions as above. As a result, a flexible laminate without wrinkles was obtained. The dimensional change rate after etching was MD-0.02 and TD ± 0.00.

(Example 4) Lamination was carried out under the same conditions as in Example 1 except that a ribbon roll as shown in Fig. 5 was installed immediately before laminating and the adhesive film was stretched by 100.40% in the TD direction. As a result, a flexible laminate without wrinkles was obtained. The dimensional change rate after etching is M
It was D-0.01 and TD-0.03.

(Comparative Example 1) Immediately before lamination, nothing was done as shown in FIG. 6 and lamination was performed under the same conditions as in Example 1. As a result, thin wrinkles occurred on the surface of the flexible laminate. The dimensional change after etching is M
It was D-0.10 and TD + 0.07.

[0025]

By using the method for producing a laminated plate according to the present invention, it is possible to obtain a laminated plate having a good appearance even when a rolled copper foil which is easily wrinkled during lamination is used. Therefore, the present invention provides a material suitable as a flexible laminated board for electronic and electric devices.

[Brief description of drawings]

[Fig.1] Pass line of each material during lamination

[Figure 2] Top view of the laminate

[Fig. 3] Pass line for each material during lamination

[Fig. 4] Pass line for each material during lamination

FIG. 5: Pass line for each material during lamination

[Fig. 6] Pass line for each material during lamination

[Explanation of symbols]

1: Metal material 2: Adhesive film 3: Protective film 4: Thermal roll laminating device 5: Protective film winding device 6: Product winding device 7: Pinch roller 8: Expander roller 9: Freeroll 10: Banana roll 11: Herribbon roll

Claims (4)

[Claims] 1. A method for producing a laminated plate, which comprises continuously laminating an adhesive film and a metal material with a hot roll laminating apparatus, wherein the adhesive film is stretched in the width direction (TD direction) immediately before lamination. A method for manufacturing a flexible laminate characterized by the above. 2. The stretch ratio in the width direction (TD direction) is 100.0.
It is 5 to 100.50%, The manufacturing method of the flexible laminated board of Claim 1. 3. The method for producing a flexible laminate according to claim 1, wherein the adhesive film is an adhesive film containing 50% by weight or more of thermoplastic polyimide in an adhesive component. 4. The method for producing a flexible laminate according to claim 1, wherein the metal material is a copper foil having a thickness of 50 μm or less.