JP2023135939A - Method for manufacturing single-sided metal-clad laminate - Google Patents

Abstract

To provide a method for manufacturing a single-sided metal-clad laminate with small warpage using an adhesive sheet having thermoplastic resin layers on both sides.SOLUTION: A method includes: using an adhesive sheet having thermoplastic resin layers on both sides of a heat-resistant film; laminating a metal foil, the adhesive sheet and a protective material 1 in this order; selecting the adhesive sheet and the protective material 1 that have specific coefficients of linear expansion; and performing thermal lamination by pre-heating the adhesive sheet and adjusting a feeding tension as necessary, thereby controlling warpage to a minimum.SELECTED DRAWING: None

Description

The present invention relates to a method for manufacturing a single-sided metal-clad laminate suitable for use in flexible printed circuit boards (hereinafter also referred to as FPCs) and the like. More specifically, the present invention relates to a method for manufacturing a single-sided metal-clad laminate using a heat-resistant film having thermoplastic resin layers on both sides for producing a single-sided metal-clad laminate.

BACKGROUND OF THE INVENTION Electronic devices are rapidly becoming more sophisticated, functional, and smaller, and along with this, there is an increasing demand for electronic components used in electronic devices to be smaller and thinner. Furthermore, costs have been reduced, and the materials constituting FPCs have become more diverse in response to demands.

Conventionally, metal-clad laminates suitable as printed circuit boards for electronic and electrical equipment include single-sided metal-clad laminates in which metal foil is laminated only on one side of a polyimide film, or structures in which metal foil is laminated on both the front and back sides. Double-sided metal-clad laminates are known. As a manufacturing method for a double-sided metal-clad laminate having such a structure, a polyimide film and a metal foil are bonded together at high temperatures with a protective film interposed between a pair of metal rolls (hereinafter also referred to as heat lamination). It has been proposed (for example, Patent Document 1). Also, without using a protective film. There is also a method of thermally laminating a polyimide film and metal foil between a pair of metal rolls.

Japanese Patent Application Publication No. 2001-129918

A single-sided metal-clad laminate can also be manufactured in principle by the method disclosed in Patent Document 1. That is, by laminating metal foil on only one side, it can be manufactured by thermal lamination in the same way as double-sided metal-clad laminates. However, this manufacturing method has a problem in that depending on the type of polyimide film and protective film used, warpage becomes large.

The present invention has been made in view of the above-mentioned problems, and its purpose is to provide a method for manufacturing a single-sided metal-clad laminate with small warpage using an adhesive sheet having thermoplastic resin layers on both sides. be.

As a result of intensive studies to solve the above problems, the present inventors discovered that the desired metal-clad laminate could be obtained by the following method, and completed the present invention. That is, the present invention has the following configuration.

1). A method for producing a single-sided metal-clad laminate comprising a heat-resistant film having a thermoplastic resin layer on both sides, and a metal foil laminated on one side of the adhesive sheet, the method comprising:
The metal foil, the adhesive sheet, and the protective material 1 are laminated in the order of metal foil/adhesive sheet/protective material 1, heat laminated, and then the protective material 1 is peeled off to form a single-sided metal cladding made of metal foil/adhesive sheet. A method for producing a single-sided metal-clad laminate to obtain a laminate,
Using an adhesive sheet and protective material 1 in which the linear expansion coefficient X1 of the adhesive sheet and the linear expansion coefficient X2 of the protective material 1 satisfy the relationship |X2-X1││7ppm/°C, the adhesive sheet was heated to 130°C before thermal lamination. A method for producing a single-sided metal-clad laminate, characterized by preheating at a temperature of from 300°C to 300°C.

2). The single-sided metal-clad laminate according to item 1), characterized in that the protective material 2 is placed on the outer surface of the metal foil, the protective material 2/metal foil/adhesive sheet/protective material 1 are laminated in this order, and thermal lamination is performed. Production method.

3). The method for producing a single-sided metal-clad laminate according to item 1) or 2), wherein the adhesive sheet has a feeding tension of 2 to 10 kgf/m.

4). The method for producing a single-sided metal-clad laminate according to any one of 1) to 3), wherein the heat-resistant film is a non-thermoplastic polyimide film.

5). The method for producing a single-sided metal-clad laminate according to any one of 1) to 4), wherein the thermoplastic resin layer contains a thermoplastic polyimide resin.

According to the present invention, a single-sided metal-clad laminate with small warpage can be manufactured using a conventionally produced thermal laminating apparatus for double-sided metal laminates.

Embodiments of the present invention will be described in detail below. However, the present invention is not limited thereto, and can be implemented with various modifications within the described range.
In this specification, unless otherwise specified, the numerical range "A to B" means "A or more (including A and larger than A) and B or less (including B and smaller than B)".

<Heat-resistant film>
In the present invention, "heat resistance" means being able to withstand use at heating temperatures during thermal lamination. Therefore, the heat-resistant film is not particularly limited as long as it satisfies the above properties, and various known films such as polyimide film and polyethylene naphthalate can be used, for example. Among these, a heat-resistant polyimide film is preferred because it is excellent not only in heat resistance but also in physical properties such as electrical properties.

The above-mentioned "heat-resistant polyimide film" contains 90% by weight or more of polyimide resin in the resin component, and when the film is heated at 380 ° C. for 2 minutes, it does not wrinkle or stretch and retains its shape. It means polyimide, and in the present invention, it is also referred to as non-thermoplastic polyimide.

Generally, polyimide films can be manufactured using polyamic acid as a precursor. Any known method can be used to produce polyamic acid, and usually, aromatic tetracarboxylic dianhydride and aromatic diamine are dissolved in substantially equimolar amounts in an organic solvent to produce a polyamic acid in a controlled manner. It can be produced by stirring under temperature conditions until the polymerization of the aromatic tetracarboxylic dianhydride and aromatic diamine is completed. These polyamic acid solutions are usually obtained at a concentration of 5 to 35% by weight, preferably 10 to 30% by weight. A suitable molecular weight and solution viscosity can be obtained at a concentration within this range.

As the polymerization method, any known method or a combination thereof can be used. A feature of the polymerization method for polyamic acid is the order in which the monomers are added, and by controlling the order in which the monomers are added, the various physical properties of the resulting polyimide can be controlled. Therefore, in the present invention, any monomer addition method may be used for the polymerization of polyamic acid. Typical polymerization methods include methods 1) to 5) below, and these methods may be used alone or in partial combination.

1) A method of dissolving an aromatic diamine in an organic polar solvent and reacting the same with substantially equimolar aromatic tetracarboxylic dianhydride for polymerization.
2) Aromatic tetracarboxylic dianhydride and an aromatic diamine compound in a smaller molar amount relative to the dianhydride are reacted in an organic polar solvent to obtain a prepolymer having acid anhydride groups at both ends. Subsequently, a method of polymerizing using an aromatic diamine compound such that the aromatic tetracarboxylic dianhydride and the aromatic diamine compound are substantially equimolar in all steps.
3) An aromatic tetracarboxylic dianhydride and an aromatic diamine compound in an excess molar amount relative to the dianhydride are reacted in an organic polar solvent to obtain a prepolymer having amino groups at both ends. Subsequently, a method of polymerizing using aromatic tetracarboxylic dianhydride such that the aromatic tetracarboxylic dianhydride and the aromatic diamine compound are substantially equimolar in all steps.
4) A method in which an aromatic tetracarboxylic dianhydride is dissolved and/or dispersed in an organic polar solvent and then polymerized using an aromatic diamine compound so that the moles thereof are substantially equimolar.
5) A method of polymerizing by reacting a mixture of substantially equimolar aromatic tetracarboxylic dianhydride and aromatic diamine in an organic polar solvent.

In the present invention, polyamic acid obtained using any of the above polymerization methods may be used, and the polymerization method is not particularly limited.

Examples of the aromatic diamine include, but are not limited to, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 2,2-bis{4 -(4-aminophenoxy)phenyl}propane, 2,2-bis{4-(4-aminophenoxy)phenyl}hexafluoropropane, bis{4-(3-aminophenoxy)phenyl}sulfone, bis{4-( 4-aminophenoxy)phenyl}sulfone, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 3, 3'-Diaminobenzophenone, 4,4'-diaminobenzophenone, 3,3'-dichlorobenzidine, 3,3'-dimethylbenzidine, 2,2'-dimethylbenzidine, 3,3'-dimethoxybenzidine, 2,2' -dimethoxybenzidine, 1,4-diaminobenzene (p-phenylenediamine), 1,3-diaminobenzene (m-phenylenediamine), 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, 9, 9-bis(4-aminophenyl)fluorene, 4,4'-(1,4-phenylenebis(1-methylethylidene))bisaniline, 4,4'-(1,3-phenylenebis(1-methylethylidene)) ) bisaniline, 4,4'-diaminobenzanilide, etc., or a combination of two or more thereof.

In addition, the aromatic tetracarboxylic dianhydride is not limited to, for example, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 2,2',3 , 3'-benzophenone tetracarboxylic dianhydride, 4,4'-oxydiphthalic dianhydride, 3,4'-oxyphthalic dianhydride, ethylene bis (trimellitic acid monoester acid anhydride), bisphenol A bis (trimellitic acid monoester acid anhydride), pyromellitic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, 3,3',4,4'-dimethyldiphenylsilane tetracarboxylic dianhydride, 3,3',4,4'-tetra Phenylsilane tetracarboxylic dianhydride, 1,2,3,4-furantetracarboxylic dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenylpropane dianhydride, 4,4' -Hexafluoroisopropylidene diphthalic anhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, p-phenylene Examples include aromatic tetracarboxylic dianhydrides such as bis(trimellitic acid monoester anhydride) and p-phenylene diphthalic anhydride, or a combination of two or more thereof.

The aromatic diamine and the aromatic tetracarboxylic dianhydride may be reacted in substantially equimolar amounts, and the order of addition, combination of monomers, and composition are not particularly limited. do not have.

The organic solvent used as a polymerization solvent for producing polyamic acid is not particularly limited as long as it dissolves the aromatic diamine, aromatic tetracarboxylic dianhydride, and the obtained polyamic acid. . As the polymerization solvent, for example, amide solvents such as N,N-dimethylformamide, N,N-diethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone are preferable. A resin solution can be prepared using an organic solvent solution of polyamic acid (polyamic acid solution) as it is.

The reaction temperature for producing polyamic acid is preferably -10°C to 50°C. By controlling the temperature within this range, the reaction proceeds at a good reaction rate and productivity is excellent, which is preferable. Further, the reaction time is not particularly limited, but is usually several minutes to several hours.

In the present invention, the curing agent includes at least one of a dehydrating agent and a catalyst.
Here, the dehydrating agent is not particularly limited as long as it can dehydrate polyamic acid by dehydration and ring closure, but examples include aliphatic acid anhydrides, aromatic acid anhydrides, N,N'-dialkylcarbodiimides, lower aliphatic Examples include halides, halogenated lower aliphatic acid anhydrides, arylsulfonic acid dihalides, and thionyl halides. These may be used alone or in an appropriate combination of two or more. Among these, aliphatic acid anhydrides and aromatic acid anhydrides can be particularly preferably used.

The catalyst is not particularly limited as long as it is a component that has the effect of promoting the dehydration ring-closing action of the dehydrating agent on polyamic acid, but specifically, for example, an aliphatic tertiary amine, an aromatic tertiary amine, etc. , heterocyclic tertiary amines, and the like.
Fillers can also be added to the heat-resistant film (A) for the purpose of improving various properties of the film such as sliding properties, thermal conductivity, electrical conductivity, corona resistance, and loop stiffness. Any filler may be used, but preferred examples include silica, titanium oxide, alumina, silicon nitride, boron nitride, calcium hydrogen phosphate, calcium phosphate, and mica.

<Thermoplastic resin layer>
In the present invention, examples of the thermoplastic resin layer disposed on both sides of the heat-resistant film and constituting the adhesive sheet include polycarbonate resin, acrylonitrile-styrene copolymer resin, thermoplastic polyimide resin, etc. From the viewpoint of heat resistance, thermoplastic polyimide resins are particularly preferably used. The content, molecular structure, and thickness of the thermoplastic polyimide resin contained in the layer can be adjusted as long as the thermoplastic polyimide resin exhibits desired properties such as significant adhesive strength with metal foil and a suitable coefficient of linear expansion. It is not particularly limited. However, in order to exhibit desired properties such as significant adhesive strength and a suitable linear expansion coefficient, it is preferable that the thermoplastic polyimide resin is substantially contained in the thermoplastic resin layer in an amount of 50% by weight or more. Furthermore, the thermoplastic polyimide resins contained in the thermoplastic resin layers facing each other with the heat-resistant film interposed therebetween must be of the same type from the viewpoint of balancing the coefficient of linear expansion of the entire adhesive sheet and simplifying the manufacturing process. is preferred.

As the thermoplastic polyimide resin contained in the thermoplastic resin layer, for example, thermoplastic polyamideimide, thermoplastic polyetherimide, thermoplastic polyesterimide, etc. can be suitably used.

The thermoplastic polyimide contained in the thermoplastic resin layer can be obtained by a conversion reaction from its precursor, polyamic acid. As a method for producing the polyamic acid, any known method can be used, as in the case of the precursor of the non-thermoplastic polyimide resin that can be used in the heat-resistant film.

Considering that the thermoplastic polyimide resin used in the present invention exhibits significant adhesive strength with the metal foil and does not impair the heat resistance of the obtained single-sided metal-clad laminate (E), the thermoplastic polyimide resin used in the present invention has a temperature of 150°C to 300°C. It is preferable that the glass transition temperature (Tg) is within the range of . Note that Tg can be determined from the value of the inflection point of the storage modulus measured by a dynamic viscoelasticity measuring device (DMA).

The polyamic acid as a precursor of the thermoplastic polyimide that can be used in the present invention is not particularly limited, and any known polyamic acid can be used. Regarding the production of the polyamic acid solution, the raw materials and production conditions exemplified above can be appropriately selected and used in the same manner.

Various properties of thermoplastic polyimide can be adjusted by combining various raw materials such as aromatic tetracarboxylic dianhydride and aromatic diamine, but in general, aromatic diamine with a rigid structure is used in a large proportion. In this case, the glass transition temperature may become high, the storage modulus upon heating may become large, and the adhesiveness and processability may become low. For example, the usage ratio of the aromatic diamine having a rigid structure is preferably 40 mol% or less, more preferably 30 mol% or less, particularly preferably 20 mol% or less, based on the total amount of aromatic diamine.

Specific examples of preferred thermoplastic polyimide resins include aromatic diamines and aromatic tetracarboxylic dianhydrides that can be used in the heat-resistant polyimide film described above. More preferably, an acid dianhydride such as benzophenonetetracarboxylic dianhydride, biphenyltetracarboxylic dianhydride, oxydiphthalic dianhydride, biphenylsulfonetetracarboxylic dianhydride, and an aromatic diamine having an aminophenoxy group. Examples include those subjected to a polymerization reaction.

Furthermore, for the purpose of controlling the slipperiness of the adhesive sheet according to the present invention, inorganic or organic fillers or other resins may be added as necessary.

<Method for manufacturing adhesive sheet>
The method of manufacturing the adhesive sheet having thermoplastic resin layers on both sides of the heat-resistant film according to the present invention is not particularly limited, but in the case of a three-layer adhesive sheet, the heat-resistant film serving as the core layer is heated. Examples include a method of forming a plastic resin layer on one side or both sides simultaneously, a method of forming a thermoplastic resin layer into a sheet shape, and a method of bonding this to the surface of the heat-resistant film that will become the core layer. Alternatively, a method of producing an adhesive sheet in which a laminate is substantially formed in one step by co-extruding a heat-resistant film serving as a core layer and a thermoplastic resin layer may be used.

For example, when using a thermoplastic polyimide resin for the thermoplastic resin layer, a resin solution obtained by dissolving or dispersing the thermoplastic polyimide resin or a resin composition containing the thermoplastic polyimide resin in an organic solvent is applied to the surface of the heat-resistant film. Alternatively, a solution of polyamic acid, which is a precursor of thermoplastic polyimide, may be prepared, applied to the surface of the heat-resistant film, and then imidized. The conditions for synthesizing polyamic acid and imidizing polyamic acid at this time are not particularly limited, but conventionally known raw materials and conditions can be used. When polyamic acid is fired, excessive heating can lower the tackiness, but may cause problems such as increased moisture absorption and film deterioration. Further, the polyamic acid solution may contain, for example, a coupling agent, depending on the purpose.

In addition, the thickness structure of each layer related to the adhesive sheet in the present invention may be adjusted as appropriate so as to have a total thickness depending on the application, but the linear expansion coefficient of each layer is It is preferable to adjust the thickness balance of each thermoplastic resin layer while taking this into account. When the difference in the linear expansion coefficients of the thermoplastic resin layers facing each other via the heat-resistant film is small, it becomes easy to balance the thickness. Further, the total thickness of the adhesive sheet is preferably 5 μm to 50 μm. Within this range, it can be suitably used as a base material for FPC. As the adhesive sheet in the present invention, it is also possible to use Pixio (registered trademark) manufactured by Kaneka Corporation.

<Metal foil>
In the present invention, the metal foil is not particularly limited, but when using the single-sided metal-clad laminate of the present invention for electronic equipment/electrical equipment, for example, copper or copper alloy, stainless steel or alloy thereof, , nickel or nickel alloy (including 42 alloy), aluminum or aluminum alloy. In general flexible laminates, copper foils such as rolled copper foils and electrolytic copper foils are often used, but they can also be preferably used in the present invention. Note that the surface of these metal foils may be coated with a rust-proofing layer, a heat-resistant layer, or an adhesive layer. Further, the thickness of the metal foil is not particularly limited, and may be any thickness that can exhibit sufficient functionality depending on the intended use. The thickness of the metal foil is, for example, preferably 3 μm to 30 μm, more preferably 5 μm to 20 μm. The surface roughness (Rz) of the metal foil is preferably 0.01 μm to 1 μm. If the surface roughness (Rz) of the metal foil is outside this range, the adhesiveness with the thermoplastic resin layer may be poor.

<Protective material 1 and protective material 2>
In the present invention, a protective material may be used to ensure a good appearance and peel strength of the single-sided metal-clad laminate. Specifically, a protective material is laminated between the pressure surface (for example, a metal roll) and the metal foil. The protective material 1 is a protective material placed in contact with the adhesive sheet, and the protective material 2 is a protective material placed in contact with the outer surface of the metal foil.

The protective material is not particularly limited as long as it can withstand the heating temperature of the thermocompression bonding process, and suitable materials include heat-resistant plastics such as non-thermoplastic polyimide films, metal foils such as copper foil, aluminum foil, and SUS foil. Can be used. Among these, non-thermoplastic polyimide films are more preferably used because of their excellent balance of heat resistance, recyclability, etc. Various known films can be used as the non-thermoplastic polyimide film, including Apical (registered trademark) manufactured by Kaneka Corporation, Upilex (registered trademark) manufactured by Ube Industries, Ltd., and Kapton (trademark manufactured by DuPont-Toray Co., Ltd.). (registered trademark), etc.

The protective material 2 may be appropriately selected and used as necessary, taking into consideration availability and the like.

On the other hand, regarding the protective material 1, if the protective material 1 and the thermoplastic resin layer are difficult to peel off, stress will be applied to peel them off, and the adhesive sheet will be stretched and warped. I realized that it had to be easy to peel.

As a result of intensive studies based on the above knowledge, the present inventors found that if the difference between the coefficient of linear expansion of the adhesive sheet and the coefficient of linear expansion of the protective material 1 is large, the expansion due to heating and cooling before and after thermal lamination. It has been found that the protective material 1 and the thermoplastic resin layer easily peel off due to the difference in shrinkage stress. That is, the adhesive sheet and protective material 1 are characterized in that the linear expansion coefficient X1 of the adhesive sheet and the linear expansion coefficient X2 of the protective material 1 are |X2-X1|≧7 ppm/°C.
If |X2−X1|<7 ppm/°C, the protective material 1 and the thermoplastic resin layer cannot be easily separated. The upper limit of |X2-X1| is preferably 35 │ More preferably, it is X2−X1|.

Here, the linear expansion coefficient can be measured and calculated, for example, as follows. That is, using TMA120C manufactured by Seiko Electronics Co., Ltd. (sample size: width 3 mm, length 10 mm), the temperature was once raised from 10 °C to 400 °C at 10 °C/min with a load of 3 g, and then cooled to 10 °C. The temperature is further increased at a rate of 10° C./min, and the average value is calculated from the coefficient of thermal expansion from 100° C. to 200° C. during the second temperature increase.

<Method for manufacturing single-sided metal-clad laminate>
The method for producing a single-sided metal-clad laminate of the present invention includes: a heat-resistant film; an adhesive sheet having thermoplastic resin layers on both sides; and a metal foil on one side of the adhesive sheet. Then, the metal foil, the adhesive sheet, and the protective material 1 are laminated in the order of metal foil/adhesive sheet/protective material 1, heat laminated, and then the protective material 1 is peeled off. This is a method for manufacturing a single-sided metal-clad laminate to obtain a single-sided metal-clad laminate, in which the linear expansion coefficient X1 of the adhesive sheet and the linear expansion coefficient X2 of the protective material 1 are |X2-X1|≧7ppm/°C. The protective material 1 is used and the adhesive sheet is preheated at a temperature of 130° C. to 300° C. before thermal lamination.

As mentioned above, in order to improve the appearance of the metal foil side of a single-sided metal-clad laminate, protective material 2 is used as necessary, and the order of protective material 2/metal foil/adhesive sheet/protective material 1 is In addition, heat lamination may be performed. The protective material 2 is also peeled off after thermal lamination, thereby obtaining a single-sided metal-clad laminate made of metal foil/adhesive sheet.

By controlling the linear expansion coefficient X1 of the adhesive sheet and the linear expansion coefficient X2 of the protective material 1, the protective material 1 and the thermoplastic resin layer can be easily separated to reduce warping, and the adhesive sheet can be removed before thermal lamination. By heating the material in advance at a heating temperature of 130° C. to 300° C., it is possible to effectively apply tension in the longitudinal direction and laminate, thereby further reducing warping. If the pre-heating temperature is less than 130°C, it will not be possible to efficiently apply tension in the longitudinal direction to laminate, and if the pre-heating temperature exceeds 300°C, the adhesive sheet will wrinkle and the appearance will deteriorate. It is not possible to obtain a good single-sided metal-clad laminate. The preheating temperature is preferably from 130°C to less than 250°C, more preferably from 130°C to 220°C, and even more preferably from 130°C to 200°C.

Although various known methods can be used for laminating, the thermocompression bonding method, which involves bonding by thermocompression bonding, is preferable because it can suppress the occurrence of wrinkles in the single-sided metal-clad laminate. Examples of methods for bonding the adhesive sheet and metal foil include thermocompression bonding using batch processing using a veneer press, thermocompression bonding using continuous processing using a hot roll laminating device (also referred to as a thermal laminating device), or a double belt press (DBP) device. From the viewpoint of productivity and equipment costs including maintenance costs, a thermocompression bonding method using a thermo-roll laminating device having one or more pairs of metal rolls is preferred. The term "thermal roll laminating device having one or more pairs of metal rolls" as used herein may be any device having metal rolls for heating and pressing materials, and the specific device configuration is not particularly limited. It's not a thing.

Further, various suitable configurations can be adopted for the way each film is passed through the thermocompression bonding device (also referred to as a pass line). For example, in the process of unrolling the adhesive sheet (C) from a roll, passing through one or more pairs of metal rolls, and then peeling off the protective material through a pair of peeling rolls to form a single-sided metal-clad laminate. The adhesive sheet may be in a straight line, or may meander through various rolls provided in a thermocompression bonding apparatus, including one or more pairs of metal rolls, a pair of peeling rolls, and the like.

The method of heating the materials to be laminated in the thermocompression bonding means is not particularly limited, and examples thereof include heating using conventionally known methods capable of heating at a predetermined temperature, such as a thermal circulation method, a hot air heating method, and an induction heating method. Means can be used. Similarly, the method of pressurizing the materials to be laminated in the thermocompression bonding means is not particularly limited, and conventionally known methods capable of applying a predetermined pressure may be used, such as a hydraulic method, a pneumatic method, a gap pressure method, etc. It is possible to use a pressurizing means that employs the following.

In addition to the above-mentioned difference in coefficient of linear expansion between the adhesive sheet and the protective material 1, it is preferable to apply tension in the longitudinal direction while applying sufficient heat because it is possible to further correct warpage and keep it small. That is, the adhesive sheet and the protective material 1 can be easily peeled off, and warping can be reduced by preheating the adhesive sheet before thermal lamination and applying tension efficiently in the longitudinal direction. In order to apply tension efficiently, the tension at which the adhesive sheet is fed out is preferably 2 to 10 kgf/m, more preferably 3 to 8 kgf/m, and particularly preferably 3 to 6 kgf/m. .

In the present invention, from the viewpoint of properties such as peel strength, dimensional stability, and warping control, the heating temperature of the first thermal laminate, that is, the thermocompression bonding temperature (laminate temperature) is set to the glass transition temperature (Tg) of the adhesive sheet used + 0. Preferably, the temperature is between 180°C and 180°C.
In addition, the lamination speed in the thermocompression bonding process, the pressure in the thermocompression bonding process (laminate pressure), metal foil tension, outfeed tension, winding tension for single-sided metal-clad laminates, etc. are adjusted as appropriate from the viewpoint of suppressing warping. be able to.

In order to obtain the single-sided metal-clad laminate according to the present invention, it is preferable to use a hot roll laminating device that presses the laminated materials while continuously heating them. A material to be laminated material feeding means for feeding out the material to be laminated may be provided, or a material to be laminated winding means for winding up the material to be laminated may be provided downstream of the thermal laminating means. By providing these means, the productivity of the hot roll laminating apparatus can be further improved. The specific configurations of the laminated material feeding means and laminated material winding means are not particularly limited, and for example, adhesive sheets, metal foils, or known materials capable of winding up the obtained single-sided metal-clad laminate are used. Examples include roll winders, etc.

Moreover, it is more preferable to provide a winding means and a feeding means for winding up and feeding out the protective material 1 and the protective material 2. If these winding means and feeding means are provided, the protective material that has been used once can be rolled up and reinstalled on the feeding side in the thermocompression bonding process, thereby making it possible to reuse the protective material. Moreover, in order to align both ends when winding up the protective material, an end position detection means and a winding position correction means may be provided. This allows the ends to be precisely aligned and wound up, thereby increasing the efficiency of reuse. Note that the specific configurations of the winding means, feeding means, end position detecting means, and winding position correcting means are not particularly limited, and various conventionally known devices can be used.

EXAMPLES Hereinafter, the method for manufacturing a single-sided metal-clad laminate according to the present invention will be explained in detail with reference to Examples, but the present invention is not limited to the Examples.

(Peel strength)
The obtained single-sided or double-sided metal-clad laminate was etched with an aqueous ferric chloride solution to form a 1 mm wide metal foil pattern, and the peel strength of the metal foil pattern was measured at an angle of 90° and a speed of 50 mm/min. ) was measured.

(linear expansion coefficient)
Using TMA120C manufactured by Seiko Electronics Co., Ltd. (sample size: width 3 mm, length 10 mm), the temperature was raised from 10 °C to 400 °C at 10 °C/min with a load of 3 g, then cooled to 10 °C, and then The temperature was raised at a rate of 10°C/min, and the average value was calculated from the coefficient of thermal expansion from 100°C to 200°C during the second temperature rise.
(Dimensional change rate)
The obtained single-sided or double-sided metal-clad laminate was cut to a size of 200 mm, and holes of 1 mm Φ were drilled in 150 mm squares, and the dimensions of the 1 mm Φ holes were measured (A) in this state. Furthermore, the metal foil was completely etched with a ferric chloride aqueous solution, dried at 50°C for 30 minutes, and left for 24 hours at a temperature of 25°C and humidity of 50%, and then the dimensions of the 1 mmΦ hole were measured (B). The dimensional change rate was calculated using the following formula. In addition, it was calculated as the average value of two sides in the longitudinal direction (MD) and the width direction (TD) of the metal-clad laminate.
100×(B-A)/A (%)

(warp)
The obtained single-sided metal-clad laminate was placed on a flat table, the height of the rectangular warpage was measured with a ruler, and the average value of the warp heights at four points was calculated as the warp.

(Example 1)
A heat-resistant double-sided adhesive sheet with a thickness of 25 μm (Pixio FRS manufactured by Kaneka Corporation; Tg 290 ° C.), a rolled copper foil with a thickness of 12 μm as a metal foil (GHY5-93F-HA-V2 manufactured by JX Nippon Mining & Metals Co., Ltd.), and Using protective material 1 (Apical (registered trademark) 50AH manufactured by Kaneka Corporation, thickness 50 μm), the composition of rolled copper foil/adhesive sheet/protective material 1 was laminated, and the adhesive sheet was fed out at a tension of 3 kgf/m and heated. After being heated to 130°C in a pre-heating device before the rolls, the material was passed between a pair of metal rolls in a hot roll laminating device under the conditions of a laminating temperature of 360°C, a laminating pressure of 244 N/cm, and a laminating speed of 1 m/min. Heat lamination was performed to obtain a single-sided metal-clad laminate. The linear expansion coefficients of the adhesive sheet and the protective material, the peel strength, dimensional stability, and warpage of the obtained single-sided metal clad plate were measured, and the results are listed in Table 1.

(Example 2)
In Example 1, the protective material 2 (Apical (registered trademark) 125NPI manufactured by Kaneka Corporation, thickness 125 μm) was placed on the outside of the rolled copper foil, and the composition was made of protective material 2/rolled copper foil/adhesive sheet/protective material 1. A single-sided metal-clad laminate was obtained in the same manner as in Example 1, except that the layers were laminated. The linear expansion coefficients of the adhesive sheet and the protective material, the peel strength, dimensional stability, and warpage of the obtained single-sided metal clad plate were measured, and the results are listed in Table 1.

(Example 3)
In Example 2, a single-sided metal-clad laminate was obtained in the same manner as in Example 2, except that the preheating temperature was 180°C. The linear expansion coefficients of the adhesive sheet and the protective material, the peel strength, dimensional stability, and warpage of the obtained single-sided metal clad plate were measured, and the results are listed in Table 1.

(Example 4)
In Example 2, a single-sided metal-clad laminate was obtained in the same manner as in Example 2, except that the tension for feeding out the adhesive sheet was 6 kgf/m. The linear expansion coefficients of the adhesive sheet and the protective material, the peel strength, dimensional stability, and warpage of the obtained single-sided metal clad plate were measured, and the results are listed in Table 1.

(Example 5)
A single-sided metal-clad laminate was obtained in the same manner as in Example 1 except that protective material 1 (Ube Industries, Ltd. (registered trademark) UPILEX S, thickness 25 μm) was used. The linear expansion coefficients of the adhesive sheet and the protective material, the peel strength, dimensional stability, and warpage of the obtained single-sided metal clad plate were measured, and the results are listed in Table 1.

(Example 6)
A single-sided metal-clad laminate according to the present invention was obtained in the same manner as in Example 2 except that a heat-resistant double-sided adhesive sheet having a thickness of 25 μm (Pixio SR manufactured by Kaneka Corporation; Tg 290° C.) was used. The linear expansion coefficients of the adhesive sheet and the protective material, the peel strength, dimensional stability, and warpage of the obtained single-sided metal clad plate were measured, and the results are listed in Table 1.

(Example 7)
In Example 2, a single-sided metal-clad laminate according to the present invention was produced in the same manner as in Example 2, except that a heat-resistant double-sided adhesive sheet with a thickness of 25 μm (Pixio IB manufactured by Kaneka Corporation; Tg 210 ° C.) was used. I got it. The linear expansion coefficients of the adhesive sheet and the protective material, the peel strength, dimensional stability, and warpage of the obtained single-sided metal clad plate were measured, and the results are listed in Table 1.

(Example 8)
In Example 2, a single-sided metal-clad laminate was obtained in the same manner as in Example 2, except that the preheating temperature was 300°C. The linear expansion coefficients of the adhesive sheet and the protective material, the peel strength, dimensional stability, and warpage of the obtained single-sided metal clad plate were measured, and the results are listed in Table 1.

(Comparative example 1)
A single-sided metal-clad laminate according to the present invention was obtained in the same manner as in Example 1 except that protective material 1 (Apical (registered trademark) 125NPI manufactured by Kaneka Corporation, thickness 125 μm) was used. The linear expansion coefficients of the adhesive sheet and the protective material, the peel strength, dimensional stability, and warpage of the obtained single-sided metal clad plate were measured, and the results are listed in Table 1.

(Comparative example 2)
A single-sided metal-clad laminate according to the present invention was obtained in the same manner as in Example 1 except that protective material 1 (KAPTON EN, DuPont-Toray Co., Ltd. (registered trademark), thickness 25 μm) was used. The linear expansion coefficients of the adhesive sheet and the protective material, the peel strength, dimensional stability, and warpage of the obtained single-sided metal clad plate were measured, and the results are listed in Table 1.

(Comparative example 3)
A single-sided metal-clad laminate according to the present invention was obtained in the same manner as in Comparative Example 1 except that a heat-resistant double-sided adhesive sheet having a thickness of 25 μm (Pixio SR manufactured by Kaneka Corporation; Tg 290° C.) was used. The linear expansion coefficients of the adhesive sheet and the protective material, the peel strength, dimensional stability, and warpage of the obtained single-sided metal clad plate were measured, and the results are listed in Table 1.

(Comparative example 4)
A single-sided metal-clad laminate according to the present invention was obtained in the same manner as in Comparative Example 1 except that a heat-resistant double-sided adhesive sheet having a thickness of 25 μm (Pixio IB manufactured by Kaneka Corporation; Tg 210° C.) was used. The linear expansion coefficients of the adhesive sheet and the protective material, the peel strength, dimensional stability, and warpage of the obtained single-sided metal clad plate were measured, and the results are listed in Table 1.

(Comparative example 5)
In Example 2, a single-sided metal-clad laminate was obtained in the same manner as in Example 2, except that the preheating temperature was not performed (room temperature). The linear expansion coefficients of the adhesive sheet and the protective material, the peel strength, dimensional stability, and warpage of the obtained single-sided metal clad plate were measured, and the results are listed in Table 1.

(Comparative example 6)
In Example 2, a single-sided metal-clad laminate was obtained in the same manner as in Example 2, except that the preheating temperature was 305°C. The linear expansion coefficients of the adhesive sheet and the protective material, the peel strength, dimensional stability, and warpage of the obtained single-sided metal clad plate were measured, and the results are listed in Table 1.

Claims (5)

A method for producing a single-sided metal-clad laminate comprising a heat-resistant film having a thermoplastic resin layer on both sides, and a metal foil laminated on one side of the adhesive sheet, the method comprising:
Metal foil, adhesive sheet, and protective material 1 are laminated in the order of metal foil/adhesive sheet/protective material 1, heat laminated, and then protective material 1 is peeled off to form a single-sided metal sheet made of metal foil/adhesive sheet. A method for producing a single-sided metal-clad laminate to obtain a stretched laminate,
Using an adhesive sheet and protective material 1 in which the linear expansion coefficient X1 of the adhesive sheet and the linear expansion coefficient X2 of the protective material 1 have a relationship of |X2-X1|││7ppm/°C, the adhesive sheet was heated at 130°C before thermal lamination. A method for producing a single-sided metal-clad laminate, characterized by preheating at a temperature of from 300°C to 300°C. The single-sided metal-clad laminate according to claim 1, characterized in that the protective material 2 is disposed on the outer surface of the metal foil, and the protective material 2/metal foil/adhesive sheet/protective material 1 are laminated in this order and thermally laminated. manufacturing method. The method for producing a single-sided metal-clad laminate according to claim 1 or 2, wherein the adhesive sheet has a feeding tension of 2 to 10 kgf/m. The method for producing a single-sided metal-clad laminate according to any one of claims 1 to 3, wherein the heat-resistant film is a non-thermoplastic polyimide film. The method for producing a single-sided metal-clad laminate according to any one of claims 1 to 4, wherein the thermoplastic resin layer contains a thermoplastic polyimide resin.