JP2003001753A - Method for manufacturing heat-resistant flexible laminated sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance productivity at the time when a heat-resistant flexible laminated sheet is to be manufactured by laminating a heat resistant adhesive film and a metal material. SOLUTION: In the method for manufacturing the heat-resistant flexible laminated sheet by laminating a metal foil and the heat-resistant adhesive film using a hot roll laminator having one or more metal roll pairs, the diameter of each metal roll is not less than 200 mm and a plurality of the metal foils and a plurality of the heat-resistant adhesive films are laminated at the same time.

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 Recently, weight reduction of electronic products,
With the miniaturization and high density, the demand for printed circuit boards has increased, and in particular, the demand for flexible printed circuit boards formed by forming a copper foil circuit on an insulating film has increased. This flexible laminated board includes a laminated board in 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 heat fusion type such as a thermoplastic resin. There is a laminated plate adhered with an adhesive (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 come to be used as the solder material,
Along with that, the heat resistance required for flexible laminates has become even more stringent.
Acrylic resins are no longer able to satisfy heat resistance.

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 recent years, the solder reflow temperature has risen with the lead-free solder paste. for that reason,
The demand for heat resistance of the flexible laminated plate is also increasing, and the adhesive used for it is also required to have heat resistance. In order to increase the heat resistance of the adhesive, measures such as increasing the glass transition temperature (hereinafter referred to as Tg) of the thermoplastic adhesive and not significantly lowering the elastic modulus of the adhesive at a temperature of Tg or higher have been made. .

When the heat-resistant adhesive film having such an adhesive formed on both sides of the heat-resistant film and the metal foil are heat-laminated by a heat roll laminating apparatus, sufficient heating is required more than ever before. However, the pressurization of the hot roll laminating device is finished in a moment when it passes between the rolls, so the laminating speed must be slowed down in order to increase the laminating time, and the productivity of the heat resistant flexible laminated plate is reduced. there were.

Also, when a heat-resistant adhesive film using a conventional adhesive is heat-laminated by a heat-roll laminating device, the pressurization of the heat-roll laminating device ends in a moment when passing between the rolls, so that there is a laminating speed. There is a problem in that the speed cannot be increased beyond a certain level, and the productivity of the flexible laminate cannot be increased.

[0007]

In view of the above problems, an object of the present invention is to provide a method for improving productivity when a flexible laminate is produced by laminating a heat resistant adhesive film and a metal material. is there.

[0008]

DISCLOSURE OF THE INVENTION The present inventors have found that productivity can be increased several times by laminating a plurality of pairs of metal materials and heat resistant adhesive films and performing thermal lamination. Reached That is, the present invention is a method for producing a heat-resistant flexible laminated plate by bonding a metal foil and a heat-resistant adhesive film using a hot roll laminating apparatus having one or more pairs of metal rolls, and the diameter of the metal roll is 200 mm. The above is the method for producing a heat-resistant flexible laminated plate, which is characterized by simultaneously laminating a plurality of layers of metal foil and a heat-resistant adhesive film, wherein the heat-resistant adhesive film contains thermoplastic polyimide in an adhesive component of 50% or less.
It is preferably an adhesive sheet containing at least wt%.

The metal foil has a thickness of 50 μm.
It is preferably a copper foil of m or less.

[0010]

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 heat-resistant adhesive film, a single-layer film made of a resin having a heat-sealing property or a plurality of resin layers having a heat-sealing property formed on both sides of a core layer having no heat-sealing property Examples of the film include a film such as a layer film, paper, and a glass cloth impregnated with a resin having a heat-sealing property. However, when a rigid base material such as a glass cloth is used, the flexibility is poor. As the adhesive film for the plate, a single-layer film made of a resin having heat-sealing property, a multi-layer film formed by forming a resin layer having heat-sealing property on both sides of a core layer having no heat-sealing property Is preferred. 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 type of filler is not particularly limited as long as it is for improving the surface property of the film, but a filler such as calcium hydrogen phosphate can be used.

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, heat fusion 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 it is composed of a single adhesive 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 sheet 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 the method of applying an adhesive to produce a three-layer adhesive film, particularly when a polyimide-based adhesive is used, a method of applying it to a heat-resistant film in the state of polyamic acid and then performing imidization while drying There is a method in which a soluble polyimide resin is applied as it is and dried, and the method for forming the adhesive 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 a heat-resistant adhesive film at one time.

In the present invention, when the metal foil and the heat-resistant adhesive film are laminated using a hot roll laminating apparatus, the pressure surface of the apparatus and the outermost layer of the laminated material (metal foil and heat-resistant adhesive film) Place a protective material between
It is preferable that the protective material and the material to be laminated are brought into close contact with each other by heating under pressure at a temperature of not less than 0 ° C., and the protective material is peeled off from the laminated plate after cooling. Here, the protective material refers to a non-constituent material of the laminated plate. Further, the protective material and the laminated material are in a state of being lightly adhered by passing through the laminating roll. Here, the state of being lightly adhered means a state in which the protective film and the material to be laminated do not peel off when no force is applied thereto, and a state where they are easily peeled off by peeling by hand.

The metal foil 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 device is not particularly limited as long as it is a device for laminating the material to be laminated by applying pressure to the material to be laminated. 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 laminating roll is not particularly limited, such as rubber and metal, but when the laminating temperature is a high temperature of 280 ° C. or more, the rubber roll deteriorates and cannot be used, and a metallic 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 diameter of the laminating roll is not particularly limited. In order to increase the productivity of the laminate, it is preferable to install two or more pairs of laminating rolls continuously. The diameters of adjacent laminating rolls are not particularly limited, but different diameters are preferable because they can be installed closer to each other.

Any protective material may be used 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 laminate 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.

The metal foil and the heat resistant adhesive film are preferably laminated in a combination of two or more in order to improve the productivity of the heat resistant flexible laminate. The term "one set" as used herein means a metal foil / heat-resistant adhesive film for a single-sided plate, and a metal foil / heat-resistant adhesive film / metal foil for a double-sided plate. 1 set and 1 for laminating
There may be nothing between the sets, but there is no problem in laminating with a protective film as a partition. Hereinafter, the present invention will be described in more detail with reference to examples.

[0021]

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. The productivity ratio of the flexible laminated plate is a ratio when the productivity of one set of the materials of Comparative Example 1 is 1. The peel strength (adhesion peel strength) was measured as follows.

(Peel Strength) JIS C6471 "6.
5 peeling strength ". Specifically, using Autograph S-100-C manufactured by Shimadzu Corporation, a sample is taken out in a state where the protective material immediately after lamination and the flexible laminated plate are in close contact with each other, and cut out to a 1 cm width to make a hard substrate. Fix it with double-sided tape on the top and pull at a peeling angle of 180 degrees from the protective film side and pulling speed of 50 mm / min.
Peeled off and the load was measured.

(Example 1) A heat-resistant adhesive film (25 μm thick PIXEO BP HT-142 manufactured by Kanegafuchi Chemical Industry Co., Ltd.) was provided on both sides with a metal foil (18 μm rolled copper foil BHY-22B- manufactured by Japan Energy).
T) are arranged in two sets as shown in FIG. 1 and protective materials (apical 125AH manufactured by Kanegafuchi Chemical Industry Co., Ltd.) are further arranged on both sides thereof, and a hot roll laminating apparatus as shown in FIG. 1 (4 in FIG. 1: Diameter of heat roll = 300 mm), lamination temperature
350 ℃, Laminating pressure 50N / mm, Laminating speed 2.0m / mi
Lamination was performed under the condition of n to obtain a flexible laminate. As a result, the peel strength (adhesion peel strength) is 10 N /
cm, and the production rate for Comparative Example 1 was twice.

Example 2 A metal foil (18 μm rolled copper foil BHY-22B-made by Japan Energy) on both sides of a heat resistant adhesive film (25 μm thick PIXEO BP HT-142 made by Kanegafuchi Chemical Industry)
In a state where three sets of T) are arranged as shown in FIG. 2 and a protective material (Apical 125AH manufactured by Kanegafuchi Chemical Industry Co., Ltd.) is arranged on both sides thereof, a hot roll laminating apparatus as shown in FIG. 2 (4 in FIG. 2: Diameter of heat roll = 300 mm), lamination temperature
350 ℃, Laminating pressure 50N / mm, Laminating speed 2.0m / mi
Lamination was performed under the condition of n to obtain a flexible laminate. As a result, the peel strength (adhesion peel strength) is 10 N /
cm, and the production rate for Comparative Example 1 was 3 times.

Comparative Example 1 A metal foil (18 μm rolled copper foil BHY-22B manufactured by Japan Energy) on both sides of a heat resistant adhesive film (25 μm thick PIXEO BP HT-142 manufactured by Kanegafuchi Chemical Industry).
T) are arranged in two sets as shown in FIG. 1 and protective materials (apical 125AH manufactured by Kanegafuchi Chemical Industry Co., Ltd.) are further arranged on both sides thereof, and a hot roll laminating apparatus as shown in FIG. 1 (4 in FIG. 1: Diameter of heat roll = 150 mm), lamination temperature
350 ℃, Laminating pressure 50N / mm, Laminating speed 2.0m / mi
Lamination was performed under the condition of n. As a result, the peel strength (adhesion peel strength) was about 6 N / cm, which was a flexible laminate.

[0026]

According to the present invention, the productivity of a flexible laminated board in a hot roll laminating apparatus can be markedly improved. Therefore, the present invention provides a material suitable as a flexible laminated board for electronic and electric devices.

[Brief description of drawings]

FIG. 1 is a pass line for laminating two sets of laminated materials.

FIG. 2 is a pass line for laminating three sets of laminated materials.

FIG. 3 is a pass line for laminating a set of laminated materials.

[Explanation of symbols]

1: Metal foil 2: Adhesive film 3: Protective film 4: Thermal roll laminating device 5: Protective film winding device 6: Product winding device

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H05K 3/46 H05K 3/46 Y F term (reference) 4F100 AB01A AB17A AB33A AK49B BA02 BA08 EA021 EJ192 EJ422 EK09 GB43 JB16B JJ03B JK17 JL11B 5E346 AA05 AA12 AA15 AA22 AA32 AA51 BB15 CC02 CC08 CC10 CC32 DD02 DD12 EE07 EE08 EE09 EE12 EE13 EE14 GG28 HH31

Claims (3)

[Claims] 1. A method for producing a heat-resistant flexible laminate by laminating a metal foil and a heat-resistant adhesive film using a hot roll laminating apparatus having one or more pairs of metal rolls, wherein the diameter of the metal roll is 200 mm. The above is a method for producing a heat-resistant flexible laminate, which comprises simultaneously laminating a plurality of layers of metal foil and a heat-resistant adhesive film. 2. The method for producing a heat-resistant flexible laminate according to claim 1, wherein the heat-resistant adhesive film is an adhesive sheet containing 50% by weight or more of thermoplastic polyimide in an adhesive component. 3. The method for producing a heat-resistant flexible laminated plate according to claim 1, wherein the metal foil is a copper foil having a thickness of 50 μm or less.