JP2003311882A - Manufacturing method for heat-resistant flexible laminated sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for a heat-resistant flexible laminated sheet not generating a defective appearance such as warpage, a lateral step or the like when a protective material is peeled from a laminated sheet in the production of a hot-melt type laminated sheet. <P>SOLUTION: In the manufacturing method for the laminated sheet constituted by continuously laminating a metal foil to a heat-resistant film having thermal fusibility by a hot roll laminator, protective materials are arranged between the pressure surfaces of both surfaces of the laminator to be molded at 200°C or higher under pressure and heating. When the protective materials are peeled from the laminated sheet after cooling, they are successively peeled by single surface. <P>COPYRIGHT: (C)2004,JPO

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 laminated plate, which is obtained by continuously laminating a metal foil on a heat-resistant film having a heat-fusible property with a hot roll laminating device. In particular, the present invention relates to a method for manufacturing a heat-resistant flexible laminated board used for electronic and electric devices and the like.

[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).

Various methods for producing thermosetting laminates have been studied so far, and resin-impregnated paper, resin-impregnated glass cloth and metal foil are pressed using a multi-stage press or a vacuum press,
After that, a method for obtaining a rigid laminate by thermosetting at a high temperature for several hours, or a method in which a roll-shaped material is sandwiched between a pair of heating rolls and laminated, and then thermosetting at a high temperature for several hours to obtain a flexible laminate A method of thermally laminating using a double belt press instead of a heating roll has been implemented. At that time, for the purpose of solving the following problems, a method is known in which a protective material is sandwiched between a pressure surface of an apparatus and a material to be laminated, and pressure heating is performed. That is,
Generation of scratches and dents on the surface of the metal foil (Japanese Patent Laid-Open No. 60-10983)
5) or warpage of the laminated plate in the curing furnace after thermal lamination (Japanese Patent Laid-Open No. 4-89254), or resin impregnated paper or resin impregnated glass cloth with resin pool and poor smoothness hinders smooth laminating. A protective material is used when a problem such as rust occurs. Further, in the heat fusion type, in JP-A-11-298114, when a copper foil is laminated on one surface of a polyimide laminate with a silicon rubber roll,
An example is described in which a protective film (non-thermoplastic polyimide film) is placed on the surface on which the copper foil is not attached, and the laminate is performed. However, in this publication, this protective film is used for the purpose of preventing the adhesive film from sticking to the laminating roll.

In the case of producing the above-mentioned thermosetting type laminated plate, the pressure-heating molding temperature is almost 200 ° C. or less in most cases. At such a heating temperature, the thermal stress applied to the material to be laminated is small, and the appearance defects such as wrinkles during thermal lamination are less likely to occur.

[0005]

However, in the case of producing a heat fusion type laminated plate, pressure and heating must be performed at a temperature higher than the glass transition temperature (denoted by Tg) of the thermoplastic resin constituting the adhesive layer. If it cannot be heat fused. On the other hand, the laminated board for electronic and electrical equipment is heated at high temperature in the process of mounting components,
At least 180 ° C for the thermoplastic resin that constitutes the adhesive layer
The above Tg is required. Furthermore, 2 for heat fusion
A thermal laminating temperature of 00 ° C or higher is required. 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.

The cause of wrinkles will be described in more detail.
When laminating, for example, a copper foil and a thermoplastic polyimide with a hot roll laminating machine, the copper foil and the thermoplastic polyimide are bonded to each other by passing between the press rolls in a heated and pressurized state of the hot roll laminating machine. When laminating,
Although each laminated material is in a state of being expanded by heat, since the coefficient of linear expansion of thermoplastic polyimide is generally larger than that of copper foil, thermoplastic polyimide is not Thermally laminated with the foil, conversely, when cooled, the thermoplastic polyimide shrinks more in the surface direction than the copper foil. For this reason, the resulting laminated plate has wrinkles in the surface direction. This is just after laminating the pressure is released,
One reason is that the material retains heat and the temperature is higher than the Tg of the thermoplastic polyimide, so that the thermoplastic polyimide is in a fluid state and the generation of wrinkles cannot be suppressed.

For the purpose of suppressing this wrinkle, a protective material, such as a polyimide film, which can withstand the high temperature at the time of lamination is laminated between the pressure surface and the material to be laminated at the time of lamination, and after lamination, A method is known in which the protective material is not immediately peeled off from the laminated laminate, but is peeled off after the temperature of the laminate falls below the Tg of the adhesive film (JP 2001-129918 A). The thermoplastic polyimide after lamination tends to shrink, but by using the protective material by this method, the movement of the laminated laminate in the surface direction is suppressed, and further, the movement of the thermoplastic polyimide is restricted and wrinkles are generated. It utilizes that it does not occur. By this method, in the heat fusion type laminated plate, it is possible to suppress the generation of wrinkles, but in the actual manufacturing process, the step of peeling the protective material is not stable,
It wasn't always enough. That is, when the protective material is peeled off from the laminated plate, if the protective material on both sides is simultaneously peeled off from the laminated plate, the peeling timing of the protective material on both sides does not match, and one of the protective materials is peeled off. Since one of the protective materials is peeled off, the peeling becomes unstable, and there is a problem that the laminated plate has a horizontal step (a phenomenon in which a rattling occurs in a direction perpendicular to the flow direction of the laminated plate) or warpage.

[0008]

In order to solve the above problems, the inventors of the present invention have earnestly studied a method of peeling a protective film from a laminate, and as a result, have completed the present invention. That is, claim 1 of the present invention relates to a method for producing a laminated plate, which is obtained by continuously laminating a metal foil on a heat-resistant film having a heat-fusible property by a heat roll laminating apparatus, wherein pressure surfaces on both sides of the apparatus are applied. A protective material is placed between the laminated material and the material to be laminated, pressure-heat molding is performed at a temperature of 200 ° C. or higher, and when the protective material is peeled from the laminated plate after cooling, it is sequentially peeled one by one. The present invention relates to a method for manufacturing a laminated board. As used herein, 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.

According to a second aspect of the present invention, when the protective material is peeled from the laminated plate, the protective material is sandwiched between a pair of peeling rolls, and the protective material is peeled off while the laminated plate is held by the peeling roll on the laminated plate side. Then, the peeling angle between the laminate and the protective material at that time is 90 degrees or more in the traveling direction side, and the method for producing the laminate according to claim 1. Claim 3 is characterized in that the diameter of the peeling roll on the side of the laminate is 80 mm or more, and the diameter of the peeling roll on the protective material side is 60 mm or less. It is a manufacturing method of the laminated board of description. According to claim 4, the heat-sealing component of the heat-resistant film having the heat-sealing property is such that the thermoplastic polyimide is 50 wt% with respect to 100 wt% of the heat-sealing component.
The method for producing a laminated board according to any one of claims 1 to 3, characterized in that the above is contained. Claim 5
The heat-resistant film having the heat-sealing property is a non-thermoplastic polyimide film having a resin having a heat-sealing component disposed on the surface of the non-thermoplastic polyimide film. Is a method for manufacturing the laminated plate. Claim 6
Is a copper foil having a thickness of 50 μm or less. 6. The method for manufacturing a laminated board according to claim 1, wherein the metal foil is a copper foil having a thickness of 50 μm or less. According to claim 7, the protective material is
It is a non-thermoplastic polyimide film, It is a manufacturing method of the laminated board as described in any one of Claim 1 to 6.

[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 purposes.

As the heat-resistant film having heat-fusible property in the present invention, a single-layer film made of resin having heat-fusible property, heat-bonded to both sides or one side of the core layer having no heat-fusible property Examples include a multi-layer film formed by forming a resin layer having heat resistance, a film such as paper or glass cloth impregnated with a resin having heat fusion property, and a rigid base material such as glass cloth. Since it is inferior in flexibility when used, as a film for heat-resistant flexible laminate,
A single-layer film made of a resin having a heat-fusible property and a multi-layer film formed by forming a resin layer having a heat-fusible property on both sides or one side of a core layer having no heat-fusible property are particularly preferable. The resin layer having a heat-fusible property is composed of a thermoplastic polyimide component, for example, a thermoplastic polyamideimide, a thermoplastic polyetherimide, a thermoplastic polyesterimide or the like is preferably used, the thermoplastic polyimide is a It is preferably contained in an amount of 50% by weight or more based on 100% by weight of the fusion-bonding component, and a thermosetting resin such as an epoxy resin or an acrylic resin may be added to the heat-fusion-bonding component in order to improve adhesiveness. Various additives may be added to the heat-sealing component in order to improve various properties.

The heat-resistant heat-resistant film of the present invention has a single-layer structure made of only the heat-fusible resin as long as it has a heat-resistant heat-fusible resin layer on the outside. However, from the viewpoint of dimensional characteristics and the like, a film having a three-layer structure in which a heat-fusible resin layer is disposed on both sides of a core layer having no heat-fusion property is preferable. Further, a two-layer structure in which a resin layer having a heat-fusible property is arranged on one surface of a core layer having no heat-fusible property can also be used. In the case of a two-layer structure, a backing layer may be provided on the surface on which the heat-sealing layer is not provided in order to prevent warping after laminating the metal foils. The core layer having no heat fusion property is not particularly limited as long as it has heat resistance, and for example, a non-thermoplastic polyimide film, an aramid film, a polyether ether ketone film, a polyether sulfone film, a polyarylate film, a polyethylene resin. Although a phthalate film and the like can be mentioned, a non-thermoplastic polyimide film is particularly preferable from the viewpoint of electrical characteristics. As a suitable configuration, for example, a film in which a thermoplastic polyimide is arranged on both sides or one side of a non-thermoplastic polyimide film can be mentioned.

The method for producing the heat-resistant film having heat-fusible property in the present invention is not particularly limited, but when it is composed of a single resin layer having heat-fusible property, it is formed by a belt casting method, an extrusion method or the like. be able to. Further, when the heat-resistant film having heat-fusible property is composed of three layers of heat-fusion layer / core layer having no heat-fusion property / heat-fusion layer, the core having no heat-fusion property is formed. A method of producing a three-layer film by applying a resin having heat fusion property to both surfaces of a layer (for example, a heat resistant film) one by one or simultaneously at the same time, or applying heat fusion property to both surfaces of the heat resistant film. There is a method of manufacturing a three-layer film by laminating a single-layer film made of only the resin contained therein. In the method for producing a three-layer film by applying a resin having a heat fusion property, particularly when a thermoplastic polyimide is used as a heat fusion component, it is applied to a heat resistant film in a polyamic acid state and then dried. While there is a method of performing imidization or a method of applying a soluble polyimide resin as it is and drying it, the method of forming the heat-sealing layer is not particularly limited. In addition, heat fusion layer /
There is also a method of co-extruding each resin of the core layer / thermal fusion layer having no thermal fusion property to form a heat resistant film having thermal fusion property at once.

The metal foil in the present invention is not particularly limited, but in the case of a laminated plate used for electronic and electrical equipment,
It is preferable to use a copper foil in terms of conductivity and cost. Regarding the thickness of the copper foil, the thinner the copper foil is, the thinner the line width of the circuit pattern can be made. Therefore, the copper foil having a thickness of 50 μm or less is preferable. In particular, since a copper foil having a thickness of 18 μm or less is less stiff than a copper foil having a thickness of more 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 18 μm or less. Moreover, rolled copper foil, electrolytic copper foil, etc. are mentioned as a kind of copper foil, and there is no particular limitation, and an adhesive such as a resin having a heat fusion property may be applied to the surface of these.

The hot roll laminating apparatus according to the present invention is not particularly limited as long as it is an apparatus for heating the material to be laminated and applying pressure thereto for laminating. The heating method is not particularly limited as long as it can be heated at a predetermined temperature, and examples thereof include a heat medium circulation method, a hot air heating method, and a dielectric heating method. The heating temperature must be 200 ° C or higher, and the laminated plate must have an ambient temperature of 240 for mounting electronic components.
When it is used for the purpose of passing through a solder reflow furnace at a temperature of 240 ° C., heating at 240 ° C. or higher is preferable because a heat-resistant film containing a heat-sealing component having a Tg corresponding thereto is used. The material of the press roll is not particularly limited, such as rubber and metal. However, when the laminating temperature is a high temperature of 280 ° C. or higher, the rubber of the rubber roll deteriorates 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.

In the present invention, the protective material may be any as long as it meets the purpose of protecting the laminated product from appearance defects such as wrinkles, and examples thereof include paper, metal foil, and plastic film. A plastic film is preferable for reasons such as cost and must be one that can withstand the temperature during processing. Therefore, a non-thermoplastic polyimide film, aramid film, polyetheretherketone film, polyethersulfone film, polyarylate film, polyethylene A heat resistant film such as a phthalate film is preferable. 25 more
When processing at 0 ° C., it is necessary to use a heat resistant film having heat resistance higher than that, and a non-thermoplastic polyimide film 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. Further, the protective material is not particularly required to be subjected to surface treatment or the like as long as it adheres lightly to the material to be laminated, but may be subjected to surface treatment or the like as necessary to suppress the adhesiveness. Further, 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, it is acceptable as long as the protective material and the laminated material are in close contact with each other. .

In the present invention, the temperature of the laminated plate when the protective material is peeled off is preferably a temperature not higher than Tg of the heat-sealing component of the heat-resistant film having heat-sealing property, which is 50 ° C. higher than Tg.
The lower temperature is more preferable, and the temperature lower than Tg by 100 ° C. or more is the most preferable. Further, in practice, it is preferable to peel off the protective material from the laminate when cooled to room temperature.

When the protective materials on both sides are peeled off simultaneously from the laminated plate, the peeling becomes unstable, and the laminated plate is caused to have a horizontal step (a phenomenon in which a rattling occurs in the direction perpendicular to the flow direction of the laminated plate) or warp. In some cases, by peeling the protective material one by one on each side, it is possible to carry out stable peeling without lateral steps or warpage. Furthermore, when the protective material is peeled off, it is sandwiched between a pair of peeling rolls and peeled while holding the laminated plate on the laminated plate side roll, so that more stable peeling is performed, which is preferable. Further, peeling while the protective material is held in the roll on the protective material side is more preferable because the peeling is further stabilized. The peeling angle of the protective material is preferably 90 degrees or more with respect to the traveling direction of the laminate. If the peeling angle is less than 90 degrees, the protective material and the laminated plate are not well peeled off due to the close contact state of the protective material, and the laminated plate is peeled off while being pulled toward the protective material side,
May cause sideways or warpage. Further, the diameter of the peeling roll on the protective material side is preferably 60 mm or less, and the diameter of the peeling roll on the laminated plate side is preferably 80 mm or more. When the diameter of the peeling roll on the protective material side is larger than 60 mm, particularly when the peeling roll on the laminated plate side has a size equivalent to that of the peeling roll, the laminated plate is peeled off while being pulled by the protective material side during peeling. It may cause warpage. If the diameter of the peeling roll on the laminate side is smaller than 80 mm, extreme bending stress is applied to the laminate plate, which may cause warpage of the laminate plate.

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

[0021]

EXAMPLES The glass transition temperature (Tg) in the examples was measured by Shimadzu DSC CELL SCC-41 (differential scanning calorimeter) under a nitrogen stream at a heating rate of 10 ° C./min.
It measured in the temperature range from room temperature to 400 degreeC. The appearance was evaluated by a numerical value obtained by measuring the degree of warpage by the following method and the presence or absence of a horizontal step (a phenomenon in which a rattling occurs in the direction perpendicular to the flow direction of the laminated plate).

Measurement of warpage: A 200 mm × 200 mm sample was cut out from the prepared flexible laminated plate, suspended vertically at the center of one side in the flow direction during manufacturing, and a straight edge was applied parallel to that side. The straight edge is applied to the concave surface of the flexible laminated plate, and the maximum distance between the straight edge and the surface of the laminated plate is measured with a metal straight scale to a unit of 1 mm (JISC.
6481).

Examples 1 to 10 Non-thermoplastic polyimide film A 25 μm thick film having a three-layer structure and a width of 260 mm having a thermoplastic polyimide resin component having Tg of 240 ° C. (PIXEO BP HC-manufactured by Kanegafuchi Chemical Industry Co., Ltd.) 142) and rolled copper foil of 18 μm on both sides (BH manufactured by Japan Energy
Y foil), and as a protective film on both sides 1
A 25 μm polyimide film (Apical 125 NPI manufactured by Kanegafuchi Chemical Industry Co., Ltd.) was placed, and the temperature was 380 with a pass line as shown in FIG.
℃, linear velocity 2.0m / min, laminating pressure 200N / c
After laminating under the condition of m, the protective film and the laminated flexible laminate were cooled to room temperature in a state of being lightly adhered, and after cooling, the protective film was peeled from the flexible laminate to prepare a flexible laminate (Table 1 The detailed conditions are shown in).

As a result, a flexible laminate having less warp in appearance and no defects such as horizontal steps was obtained.

Comparative Example 1 A flexible laminated plate was produced under the conditions of Table 1 in the same manner as in Example except that the pass line shown in FIG. 2 was used.

As a result, a horizontal step was generated in the appearance, warpage was severe, and the appearance was poor.

[0027]

[Table 1]

[0028]

By using the method for producing a laminated plate according to the present invention, a laminated plate having a good appearance can be obtained.
Therefore, the present invention provides a material suitable as a heat-resistant flexible laminate, particularly for electronic and electrical equipment.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of a thermal laminator and a pass line.

FIG. 2 is a conceptual diagram of a thermal laminator and a pass line.

[Explanation of symbols]

1 metal foil 2 Heat-resistant film with heat-sealing property 3 protective materials 4 heat roll laminating equipment 5 Protective material winding device 6 Product winding device

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4F100 AB17B AB17C AB33B AB33C                       AK01A AK49A BA03 BA06                       BA10B BA10C EJ192 EJ412                       EJ912 EJ933 EJ943 GB43                       JJ03A JL04 JL12A

Claims (7)

[Claims] 1. A method for producing a laminated plate, which comprises continuously laminating a metal foil onto a heat-resistant film having a heat-fusible property by means of a hot roll laminating apparatus, wherein a pressing surface on both sides of the apparatus and a material to be laminated. A protective plate is placed between the protective layer and the protective plate, pressure-heat molding is performed at a temperature of 200 ° C. or higher, and when the protective plate is peeled off from the laminated plate after cooling, the laminated plate is sequentially peeled off one by one. Method. 2. When the protective material is peeled from the laminated plate, the protective material is sandwiched between a pair of peeling rolls, and the protective material is peeled off while holding the laminated plate on the peeling roll on the laminated plate side. The method for producing a laminated plate according to claim 1, wherein the peeling angle of the protective material is 90 degrees or more in the traveling direction. 3. The diameter of the peeling roll on the laminate side is 80.
The diameter of the peeling roll on the side of the protective material is 60 mm or less, and the diameter of the peeling roll is 60 mm or less.
The method for manufacturing the laminated board according to any one of 1. 4. The heat-sealing component of the heat-resistant film having the heat-sealing property is thermoplastic polyimide polyimide heat-sealing component 100.
The method for producing a laminated board according to any one of claims 1 to 3, wherein the content is 50% by weight or more with respect to% by weight. 5. The heat-resistant film having the heat-sealing property,
A non-thermoplastic polyimide film having a resin having a heat-sealing component on the surface thereof.
5. The method for manufacturing a laminated plate according to any one of items 1 to 4. 6. The method for manufacturing a laminated board according to claim 1, wherein the metal foil is a copper foil having a thickness of 50 μm or less. 7. The method for manufacturing a laminated board according to claim 1, wherein the protective material is a non-thermoplastic polyimide film.