JPH02178042A - Thermosetting resin film - Google Patents

Abstract

PURPOSE:To obtain a thermosetting resin film capable of being utilized to form an insulated layer having thickness and an electromagnetic shielding layer on a base plate with good workability by laminating and supporting thermosetting epoxy resin composition on a supporting film. CONSTITUTION:As thermosetting epoxy resin composition applied to a supporting film, the composition which shows a liquid state at ordinary temp. or under heating (heating up to about 200 deg.C) so that it can be applied to the supporting film may be utilized. Generally thermosetting epoxy resin contg. a curing agent is utilized. For example, glycidyl ether type epoxy resin of bisphenol A is shown. As a curing agent for epoxy resin, for example, dicyandiamide, etc., are shown for a preferable nitrogen-contg. latent curing agent. As the supporting film for the resin film consisting of the thermosetting epoxy resin component, various synthetic resin films can be used. For example, the supporting film is formed of synthetic resin such as PE. In the case of applying the composition to the supporting film, a roll coating method, etc., are used as the applying method.

Description

Detailed Description of the Invention (Technical Field) The present invention relates to the formation of an insulating layer or an electromagnetic shielding layer on a conductive solid surface, particularly on the surface of a printed circuit board used in televisions, radios, computers, word processors, etc. The present invention relates to a thermosetting resin film made of a thermosetting epoxy resin composition used for forming, etc.

(Prior art and its problems) It is known to provide an insulating layer and an electromagnetic shielding layer on a board in order to obtain an electromagnetically shielded printed wiring board (Japanese Utility Model Publication No. 55-29276). Since the board itself is electromagnetically shielded,
It has the advantage that a large shielding effect can be obtained, and special shielding wires, shielding plates, shielding cases, etc. are not required.

By the way, when forming an insulating layer on a substrate, conventionally, a phenol resin or an epoxy resin has been applied by a printing method. Furthermore, when forming an electromagnetic shielding layer on an insulating layer, a conductive paint is similarly applied by a printing method. However, such a printing method has problems such as poor workability and difficulty in forming a thick coating m.

(Title A of the Invention) The present invention overcomes the above-mentioned drawbacks found in the prior art, and provides a thermosetting material that can be used to form a thick insulating layer or electromagnetic shielding layer on a substrate with good workability. The objective is to provide a resin film.

(Means for Solving the Problems) The present inventors have conducted extensive research to solve the above problems, and as a result, have completed the present invention.

That is, according to one aspect of the present invention, there is provided a thermosetting resin film comprising a thermosetting epoxy resin composition laminated and supported on a support film.

In order to obtain the thermosetting resin film of the present invention, a thermosetting epoxy resin composition (hereinafter also simply referred to as a composition) is applied in liquid form onto a support film at room temperature or under heating, and then solidified. When applied at room temperature, the applied composition is solidified after the applied material is heated to advance the curing reaction of the composition to some extent.

This can be done by cooling to room temperature.

In addition, in the case of coating under heating, the coated material may be cooled to room temperature, and if it contains an organic solvent, the organic solvent may be evaporated and dried after coating. The composition has thermosetting properties and is first softened and melted by heating, and then hardened by further heating.6 In the present invention, the softening temperature of the film (covered) of the composition formed on the support is is preferably defined at 0 to 200°C, preferably 20 to 150°C, and the thickness of the composition film is 10 to 500 ps, preferably 2
It is preferable to specify the range of G-200pm.

The thermosetting epoxy resin composition to be applied to the support film may be one that is liquid at room temperature or under heating (heating up to about 200°C) so that it can be applied to the support film. A thermosetting epoxy resin containing a curing agent is used.

Next, the epoxy resin composition for forming a resin film used in the present invention will be described in detail.

The epoxy resin used for forming the resin film in the present invention is not particularly limited as long as it is a polyepoxy compound that is liquid at room temperature or under heating and has two or more epoxy groups in one molecule. For example, glycidyl ether type epoxy resin of bisphenol^, glycidyl ether type epoxy resin of bisphenol F, glycidyl ether type epoxy resin of bisphenol AO, and glycidyl ether type epoxy resin of glycerin.

Glycidyl ether type epoxy resin of polyalkylene oxide, glycidyl ester type epoxy resin of dimer acid, glycidyl ester type epoxy resin of isophthalic acid, glycidyl ether type epoxy resin of brominated bisphenol A, epoxy resin made by epoxidizing polybutadiene with peracetic acid. In the present invention, from the viewpoint of properties as a resin film, it is preferable to use bisphenol A type epoxy resin. Mixtures of the above epoxy resins and mixtures with epoxy compounds for lowering the viscosity of the epoxy resin are also used. be able to.

Furthermore, the above epoxy resins and mixtures include epoxy resins that are crystallized at room temperature, such as glycidyl-type epoxy resins such as resorcinol and hydroquinone, and epoxy resins that are solid at room temperature, as long as they are liquid at room temperature or under heating. Can be dissolved.

As the curing agent for the epoxy compound, a latent curing agent that causes a curing reaction when heated is preferably used, and a curing agent that causes a curing reaction at low temperature can also be used. As latent curing agents, nitrogen-containing submersible substances, phenolic compounds,
Specific examples of preferable nitrogen-containing latent curing agents used in the present invention include novolak type phenolic resins, etc.
For example, in addition to dicyandiamide, guanamines such as acetoguanamine and benzoguanamine, hydrazides such as adipic acid dihydrazide, stearic acid dihydrazide, isophthalic acid dihydrazide, and sepatic acid dihydrazide, 2,4-dihydrazide-6-methylamino-8-
Examples include triazine compounds such as triazine, imidazole and imidazole derivatives, or modified products thereof.

The latent curing agent is preferably used together with a curing accelerator.As such curing accelerator, it is preferable to use the following.

(1) Amine adduct curing accelerator Examples of the curing accelerator include (i) 2,3-bis(4-(2,3-epoxypropoxy)phenyl)propane or 1,3-bis(4-( 4-(2,3-epoxypropoxy)-α,α-dimethylbenzyl]phenoxy)-2-propatol, (ii) condensate of phenol, formaldehyde, and dimethylamine, (i) 2-alkyl (1 carbon number ~3) Imidazole or 2-alkyl (
(1-3 carbon atoms)-4-methylimidazole and 2,3-epoxypropyl-phenyl ether adduct and (i
v) Preference is given to using polyadducts of piperazine.

(2) Solid solution of 1,8-diaza-bicyclo(5,4,0) undecene and phenol novolac This solution is 1,8-diaza-bicyclo(5,4,0)
It can be obtained by mixing, heating and reacting undecene-7 and phenol novolac, cooling the mixture, solidifying it, and pulverizing it. Phenol novolac means a condensate of phenols and aldehydes. As phenols,
Included are monohydric phenols such as phenol, alkyl or alkoxyphenols, halogenated phenols, and polyhydric phenols such as resorcinol or bisphenol A.

Preferred phenols are phenol, p-tert-butylphenol and bisphenol A. Examples of aldehydes include furfuraldehyde, chloral, acetaldehyde, and preferably formaldehyde. ■,
The solid solution of 8-diazo-bicyclo(5,4,0)undecene-7 and phenol novolak may include not only a complete salt form but also a simple solid solution. The content of diazo-bicyclo(5,4,0)undecene-7 in the solid solution is preferably 10 to 50% by weight, and does not necessarily have to be a stoichiometric amount.

(3) Other urea derivatives such as 3-(3,4-dichlorophenyl)-1,1-dimethylurea, imidazole and its derivatives.

Or modified products thereof can also be used. These curing accelerators are appropriately selected in relation to the latent curing agent.

The amount of the nitrogen-containing latent curing agent used is preferably 0.03 to 0.25 mol per equivalent of the epoxy resin. If it is too small, the glass transition point of the cured product will be low and the moisture resistance will be reduced. Moreover, the curing speed during curing is slow. On the other hand, if the amount is too large, the storage stability of the composition will be poor, the glass transition point of the cured product will not be particularly high, and the moisture resistance will be poor. In addition, the usage ratio of the curing accelerator is 10 parts of epoxy resin.
A ratio of 1 to 30 parts by weight relative to 0 parts by weight is preferable; if the ratio is too small, the curing speed will be slow. If the amount is too large, the cost will be high and no particular advantage will be obtained, and on the contrary, the storage stability will deteriorate.

Furthermore, various types of curing agents that cause curing reactions at relatively low temperatures are known, but aromatic polyamines are particularly preferably used. Examples of such compounds include metaphenylene diamine, diaminodiphenylsulfone, and the like. The amount of aromatic polyamine used is such that the ratio of active hydrogen equivalent to epoxy equivalent of the epoxy resin is 0.
．． 7 to 1.3, preferably 0.85 to 1.15.

The epoxy resin composition may contain inorganic fillers and
An inorganic thixotropic agent can be blended. These things are
Although it can be blended into the epoxy resin as it is without surface treatment, considering the physical properties of the cured product, it is preferable to perform surface treatment with a silane coupling agent.As the silane coupling agent, epoxysilane, aminosilane, etc. etc. are preferably used. Furthermore, considering the storage stability of a composition, it is preferable to use it after surface treatment with a siloxane compound.In this case, a siloxane compound is a compound having a siloxane bond (Si-0 bond) in one molecule. For example, the following compounds can be used.

Hydrocarbon group n2 represents a divalent hydrocarbon group, and align, which includes aliphatic and aromatic groups, represents a positive integer.

In the formula, RlY and n have the same meanings as above.

In the formula, R is a monovalent hydrocarbon group such as methyl.

Examples include ethyl, propyl, vinyl, phenyl, etc.a
m is a positive integer.

In the formula, R has the same meaning as above. ■ is one ■, -OH
, -OR", -R"-CH-Cl,, -R"-N)1.
, -R"-COOH1ゝ0'-R"-OH, etc. In this case, R'" is 1
In the value formula, R, Y and n have the same meanings as above.

In addition, the above-mentioned substituent Y may be bonded either in the molecular chain or at the end of the molecular chain.

The viscosity (25°C) of the siloxane compound used in the present invention depends on its type, but it is generally preferable that it is 10,000 centistokes or less. The proportion is 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the thixotropic agent.

Specific examples of the inorganic filler include crystalline silica, fused silica, alumina, aluminum hydroxide, calcium carbonate, talc, clay, calcium silicate, mica, white titanium, glass fiber, glass powder, glass flakes, and spherical. Ga, Ras.

Examples include various whiskers. - The proportion of the inorganic filler used is 5 to 80% by weight per composition, preferably 20 to 75% by weight.
It is a percentage by weight.

Examples of inorganic thixotropes include ultrafine silica and alumina with an average particle size of 1100 nm or less, aluminum hydroxide, fibrous magnesium oxysulfate, powdered asbestos, fibrous silica, and silica with an average particle size of 31 m or less. Examples include fibrous potassium titanate, scaly mica, and a montmorillonite-organic base complex called bentonite. The proportion of the thixotropic agent used is 0.001 to 30 parts by weight, preferably 0.5 to 15 parts by weight, based on 100 parts by weight of the epoxy resin.

Furthermore, a reactive diluent having an epoxy group can also be added to the epoxy resin composition for the purpose of adjusting its tackiness. Examples of the reactive diluent having an epoxy group include butyl glycidyl ether, phenyl glycidyl ether, trimethylolpropane triglycidyl ether, and the like. In addition, brominated phenyl glycidyl ether with a bromine content of 40 to 50% (BR manufactured by Nippon Kayaku Co., Ltd.
OC, etc.) can also be used. Furthermore, an organic solvent can also be added for the purpose of adjusting the coating properties of the composition. Examples of such organic solvents include ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, alcohols such as methyl alcohol, ethyl alcohol, and isopropyl alcohol, cellosolves such as methyl cellosolve and ethyl cellosolve, benzene, toluene, and xylene. Examples include aromatic hydrocarbons, halogenated hydrocarbons such as methylene chloride, and ethane dichloride.

The epoxy resin composition includes the epoxy resin described above, a latent curing agent, a reaction accelerator, a filler, and a thixotropic agent.

In addition to reaction diluents, organic solvents, etc., flame retardants,
Flame retardant aids, dyes, pigments, dispersants, anti-settling agents, etc. can be used.

Various synthetic resin films can be used as the support film for the resin film made of the thermosetting epoxy resin composition. Examples of such materials include films formed from synthetic resins such as polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyamide, polyester, polyimide, polysulfone, polyacrylate, polyetheramide, and polycarbonate. The thickness of the synthetic resin film that can be made is 5 to 250. , preferably l
O~125. Furthermore, in the present invention, a metal film or a metal-deposited film can be used as the support film. For example, as a metal film,
Copper foil, aluminum foil, tin foil, etc. can be used. As the metallized film, metals such as silver, aluminum, and tin can be used, and polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyamide, polyester, polyimide, and polysulfone can be used.

A vapor-deposited film formed by vapor-depositing a synthetic resin film such as polyacrylate, polyetheramide, or polycarbonate can be used. The thickness of the metal layer of the metal film or metallized film is 0.1-100 IJs.

When applying a composition to a support film, coating methods such as a roll coating method or a curtain coating method are used for a liquid composition or a solution composition dissolved in an organic solvent; The composition can be melted by heating to a temperature above the softening point and applied by a hot melt coating method or the like.

In the present invention, the adhesive strength a between the support film and the resin film made of a thermosetting epoxy resin composition is defined as the bond strength a between the substrate surface and the resin film when this resin film is adhesively fixed to the substrate surface. Make the adhesive strength weaker than that of

With this, after the resin film is thermocompression bonded to the substrate surface together with the support, only the support film can be easily peeled off without peeling the resin film from the substrate surface. The adhesive strength (a) between the support film and the resin film can be easily adjusted.

For example, by changing the type of support film,
Alternatively, this can be carried out by forming in advance on the surface of the support film, or by forming in advance on the surface of the support film a subbing layer that is easily peelable from the support film, or a release agent layer.

As the material for the undercoat layer, it is preferable to use materials with beer properties such as poval resin, polystyrene resin, acrylic resin, alcohol-soluble nylon, and cellulose resins such as acetyl cellulose and nitrocellulose.Thickness of the undercoat layer is 1-10. It is.

Examples of mold release agents include various waxes, higher fatty acids, metal salts and esters thereof, silicone oil, silane coupling agents, siloxane compounds represented by the above general formulas (1) to (IV), and fluorine-based polymers. Examples include surfactants, silicone-based surfactants, and fluorine-based surfactants.

In the present invention, a resin film made of a thermosetting epoxy resin composition laminated on a support film is used not only as a single flat film but also preferably as a rolled film.

When used as a roll film, in order to prevent adhesion between the resin film surface and the support film surface, a synthetic resin film, paper/synthetic resin film, paper/synthetic resin film/paper composite paper, etc. It is preferable to intervene as a protective film (protective layer). In this case, examples of the synthetic resin film include the various ones described above. The thickness of the protective film is 5 to 100 mm. , preferably 1
It is a 2-75 trend.

These protective films can be laminated on the resin film surface by inserting them between the resin film surface and the roll surface and rolling them together with the resin film when the resin film laminated on the support is rolled. can. Alternatively, after being pressure-bonded to the surface of the resin film obtained from the coating step, it can be heat-treated and rolled. moreover,#
It is also possible to thermally press the four sides of the I-glue fiber and roll it up. For resin films formed by coating a support film with a composition containing a coating solvent, it is preferable to use paper as the protective layer. For the formed resin film, synthetic resin film, especially polyolefin resin film such as polyethylene or polypropylene with weak adhesive strength,
Preference is given to using polyvinylidene chloride copolymer films.

FIG. 1 shows a perspective view of a rolled thermosetting resin film. In this drawing, 1 indicates a thermosetting resin film, 2
In this roll-wound resin film, numeral 3 indicates a support film and 3 indicates a protective film.

Adhesive strength between resin film 1 and protective film 3 (b
) is smaller than the adhesive strength (a) between the resin film 1 and the support film 2. Therefore, the protective film 3 is
The resin film can be peeled off from the resin film 1 without peeling from the support film 2.

In addition, when winding a resin film into a roll, adhesion between the resin film and the support film is achieved by forming a release agent layer on the back side of the support film (the side on which the resin film is not formed). It can also be prevented by As the mold release agent, a silicone-based or fluorine-based surfactant, a silane coupling agent, and the above-mentioned general formula (1) are used.
Examples include siloxanes and fluoropolymers as shown in (IV). In this case, examples of the silicone surfactant include dimethylpolysiloxane, methylethypolysiloxane, methylphenylpolysiloxane, methylvinylpolysiloxane, dimethylpolysiloxane/oxyalkylene copolymer, and long-chain alkyl group-modified polysiloxane. It will be done.

Next, a method for forming an insulating layer on the surface of a printed wiring board using the thermosetting resin film of the present invention will be described in detail.

(Thermocompression bonding process of resin film) In this process, the resin film laminated and supported on the support film is peeled off if a protective layer is formed on the surface of the resin film, and then the printed wiring board is bonded. This is a process of overlapping the resin films so that they are in contact with a predetermined conductive surface of the materials, and bonding them under heat. This thermocompression bonding can be performed by various methods, but preferably by vacuum lamination. In this thermocompression bonding process,
Since the resin film is heated to a temperature higher than its softening temperature and pressurized, a softened resin film is formed in which the resin is uniformly filled up to the minute recesses on the substrate surface. This softened resin coating is then cooled and solidified.

(Step of Peeling Support Film) This step is a step of peeling and removing the support film adhering to the surface of the solidified resin film (coating) formed on the substrate as described above. In the solidified resin film formed on the substrate, the adhesive strength (a) between the support film on the surface and the resin film is determined in advance by the adhesive strength (C) between the resin film and the substrate surface. is set weaker than Therefore, the support film can be peeled off from the resin coating without peeling the resin coating from the substrate surface.

(Thermosetting step of solidified resin coating) This step is a step of heating and curing the resin coating after the support film has been peeled off as described above to convert it into a heat-infusible cured resin coating. It is. The thermosetting temperature generally ranges from 50 to 200°C, although it depends on the type of resin.

As described above, a cured epoxy resin film (insulating layer) having excellent heat resistance, chemical resistance, and insulation properties is formed on the substrate.

On the insulating layer on the substrate formed in this way, other suitable layers can be further provided as necessary6. Next, the process of forming the electromagnetic shield layer will be described in detail.

(Electromagnetic Shield Layer Formation Step) This step is a step in which a conductive layer is provided as an electromagnetic shield layer on the insulating layer formed on the substrate as described above. This step can be performed by conventionally known conductive film forming methods, such as applying a conductive paint such as silver paint or copper paint, or laminating and bonding conductive metal foil such as copper foil. Can be mentioned. By extending a part of this conductive layer to the ground terminal part of the board and bringing it into contact with the terminal,
The conductive layer can be grounded.

In addition, when providing a conductive layer on a cured resin film, it is preferable to uniformly polish the surface of this cured resin film in advance. Further, after forming the conductive layer, necessary steps such as forming through holes at predetermined locations by drilling can be performed as necessary.

In the present invention, when an insulating layer and an electromagnetic shielding layer are formed on a substrate, it can be carried out very advantageously by using a conductive film as a support film for a resin film. That is, in this case, the thermosetting resin film laminated and supported by the conductive film only needs to be thermocompression bonded to the substrate surface and heat cured, so that the above-mentioned peeling process of the support film and formation of the electromagnetic shielding layer are unnecessary. The process can be omitted, making the process extremely simple.

Furthermore, by using the thermosetting resin film of the present invention, a multilayer wiring board can be advantageously manufactured. In manufacturing multilayer wiring boards, there is a method in which copper foil is laminated on both sides of an inner layer wiring board having circuit patterns on both sides with insulating layers interposed therebetween, and the laminated copper foil is etched into a pattern.

A method is known in which a pattern is formed directly on the insulating layer by electroless plating. In these conventional methods, the insulating layer is formed by applying a liquid thermosetting epoxy resin and curing it by heating, so it is not possible to apply and cure the resin on both sides of the board at the same time, and the resin is applied to one side at a time. It was necessary to apply resin and harden it. Therefore, with this conventional method, not only is the work efficiency low, but also the resin is applied to one side of the board.
There is a problem in that it is difficult to uniformly apply the resin to the opposite surface due to the warpage of the substrate that occurs when it is cured.

When using the thermosetting resin film of the present invention, such problems can be solved and multilayer wiring boards can be manufactured.

In order to make a multilayer wiring board using the thermosetting resin film of the present invention, thermosetting resin films laminated and supported by a support film are stacked on both sides of the inner layer board, and after thermocompression bonding, the support film is After removing and heat curing to form an insulating layer, an adhesive layer is applied.

After drying, a pattern is formed by electroless plating, or a thermosetting resin film laminated and supported by a support film is layered on both sides of the inner plate, and the support film is peeled off and removed after thermocompression bonding. Further, a copper foil is bonded by heat and pressure on the thermosetting resin film bonded to both sides of the inner layer plate, and after being heated and cured, it is etched into a pattern.More advantageous in using the thermosetting resin film of the present invention. According to a method for manufacturing a multilayer wiring board, a thermosetting resin film using copper foil is used as a support film, this is thermocompression bonded to both sides of an inner layer board, and after being heated and hardened, the copper foil is patterned. Etch in shape. This method does not require the step of peeling off the support film and the step of laminating the copper foil, so the process is very simple.

As described above, when making a multilayer wiring board using the thermosetting resin film of the present invention, the resin film can be laminated on both sides of the board at the same time, hot-pressed, and cured. There is no problem of warping of the board,
In addition, a laminator can be used for thermocompression bonding, which is very efficient.

(Effects of the Invention) As shown above, the thermosetting resin film made of the thermosetting epoxy resin composition laminated and supported on the support film of the present invention forms an insulating layer and an electromagnetic shielding layer on the substrate. It can be advantageously used as a material or as an insulating material for the production of multilayer wiring boards. In this case, the thickness of the insulating layer is not particularly limited, and even a thick insulating layer can be formed with good workability by adjusting the thickness of the thermosetting resin film in advance.

Further, the use of the thermosetting resin film of the present invention is not limited to printed wiring boards, but can also be applied to various conductive solid surfaces, for example, various metal surfaces such as copper, iron, aluminum, etc. with good workability. , which can be used as a material for forming a thick insulating layer.

(Example) Next, the present invention will be explained in more detail with reference to Examples.

Example (1) Production of resin film @25Gmm, thickness 50. A thermosetting epoxy resin composition having the following component composition was applied onto the polyethylene terephthalate film using an applicator at a temperature of 20°C, and dried by heating at a temperature of 120°C.

Furthermore, a polypropylene film is layered on the coated surface.
wound on a rotating roll and having a roll-wound protective layer;
A resin film laminated and supported on a support film was obtained.

Table-1 01...Yuka shell epoxy ■, bisphenol A
Type epoxy resin, epoxy equivalent 450-5001...
Phenoxy resin (2) made by Toto Kasei ■ Heat-compression of resin film From the rolled resin film, peel off the polypropylene film (protective layer) while pulling out the resin film to a certain length, and then cut it to the required size. A resin film laminated and supported on a support film was obtained. This resin film was stacked on the printed circuit board so that it was in contact with the resin film, and after thermocompression bonding was carried out at a temperature of 80°C by vacuum lamination, the support sheet was then peeled off and an epoxy resin coating was applied to one surface. A substrate having the following properties was obtained.

(3) Thermosetting of epoxy resin coating The substrate having the epoxy resin coating obtained above was placed in a heating chamber at a temperature of 150° C. for 2 hours to heat cure the coating.

(4) Formation of shield layer Next, after smoothing and polishing the surface of the cured film formed on the substrate, a conductive paint (copper paste) is applied and dried, and an electromagnetic shield is formed on the surface via an insulating layer. A substrate with layers was obtained.

Example 2 In Example 1, the thickness of the support film was 187 m.
A resin film having a roll-wound protective layer was obtained in the same manner except that the copper foil was used.

Next, while peeling off the protective layer of the rolled resin film, the resin film was pulled out to a certain length and cut into required dimensions to obtain a resin film using copper foil as a support film.

This resin film was placed on the surface of the printed wiring board IiA substrate so that the resin film surface was in contact with the substrate surface, and the temperature was 80°C.
After thermocompression bonding at .degree. C., heat treatment was further performed at a temperature of 150.degree. C. for 2 hours.

In this way, the surface of the substrate was coated with copper foil via an insulating layer to obtain an electromagnetically shielded substrate.

Example 3 A resin film using copper foil as the support film shown in Example 2 was thermocompression bonded to both sides of an inner layer board with staff patterns formed on both sides, and then heat-cured.

Next, the copper foil surface of the laminate thus obtained is etched into a pattern by a conventional method to form a wiring pattern.
A 4WJ wiring board was obtained.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a wound resin film laminated and supported on a support film and having a protective layer on its surface. 1... Thermosetting resin film made of a thermosetting epoxy resin composition, 2... Support film, 3... Protective layer.

Claims (10)

[Claims] (1) A thermosetting resin film comprising a thermosetting epoxy resin composition laminated and supported on a support film. (2) The film according to claim 1, wherein the support is a non-conductive film. (3) The film according to claim 1, wherein the support is a conductive film. (4) The film according to any one of claims 1 to 3, wherein a release agent layer is interposed between the support film and the thermosetting resin film. (5) Claims 1 to 3, wherein a protective film is laminated on the surface.
Any film from item 4. (6) The film according to claim 5, wherein a release agent layer is interposed between the protective film and the thermosetting resin film. (7) The film according to claim 5 or 6, which is wound in a roll. (8) The film according to any one of claims 1 to 4, wherein a release agent layer is laminated on the side of the support film on which the thermosetting resin film is not laminated, and the film is wound in a roll. (9) The film according to any one of claims 1 to 8, wherein the thermosetting epoxy resin composition is a composition containing a latent curing agent and a bisphenol A epoxy resin. (10) The film according to any one of claims 1 to 9, which softens at a temperature of 20 to 150°C.