KR102429729B1 - Dry film, cured product and printed wiring board - Google Patents

Abstract

(Project) It is excellent in peelability with a carrier film, The printed wiring board provided with the dry film which has a resin layer which suppresses cracks and powder fall-off, and the hardened|cured material obtained by hardening|curing this dry film.
(Solution) A dry film having a resin layer containing a semi-solid or solid epoxy resin, a curing agent or a curing accelerator, a filler, and at least two solvents, wherein all of the at least two solvents have a boiling point of 100°C or higher It is a dry film characterized in that the boiling point differs by 5°C or more.

Description

Dry film, cured product and printed wiring board {DRY FILM, CURED PRODUCT AND PRINTED WIRING BOARD}

The present invention relates to a dry film and a printed wiring board, and more particularly, to a dry film excellent in releasability with a carrier film and having a resin layer that suppresses cracking and powder drop-off, and a cured product obtained by curing the dry film; It is related with the printed wiring board provided with the hardened|cured material.

In recent years, as a manufacturing method of a multilayer printed wiring board, the manufacturing technique of the build-up system which stacks up the resin insulating layer and the conductor layer alternately on the conductor layer of an inner-layer circuit board is attracting attention. For example, an epoxy resin composition is applied to an inner-layer circuit board on which a circuit is formed, and after heat curing, an uneven roughened surface is formed on the surface with a roughening agent, and the conductor layer is applied to plating. The manufacturing method of the multilayer printed wiring board formed by this is proposed (refer patent document 1 and patent document 2). In addition, the manufacturing method of a multilayer printed wiring board in which an adhesive sheet of an epoxy resin composition is laminated on a circuit-formed inner-layer circuit board, heat-cured, an uneven roughened surface is formed on the surface with a roughening agent, and a conductor layer is formed by plating. It has been proposed (refer to Patent Document 3).

An example of a method for forming a layer structure of a multilayer printed wiring board by a conventional build-up method will be described with reference to FIG. An outer conductor pattern 8 is formed on both surfaces of the formed laminated substrate X, and an insulating resin composition such as an epoxy resin composition is applied thereon by coating or the like, followed by heat curing to form a resin insulating layer 9 do. Subsequently, after the through-hole holes 21 and the like are appropriately formed, a conductor layer is formed on the surface of the resin insulating layer 9 by electroless plating or the like, and then a predetermined circuit pattern is applied to the conductor layer according to a conventional method. By forming the outermost layer conductor pattern 10 can be formed.

As one of the methods of forming a resin insulating layer (hereinafter, interlayer insulating layer) formed between layers in a multilayer printed wiring board, as described in Patent Document 3, a thermosetting resin composition such as an epoxy resin composition is applied onto a film. The method of forming by thermosetting the dry film which has a resin layer obtained by coating-drying after lamination is used is used.

Japanese Patent Laid-Open No. 7-304931 (claimed scope) Japanese Unexamined Patent Publication (Kokai) No. 7-304933 (claims) Japanese Patent Laid-Open No. 2010-1403 (claims)

As one of the thermosetting components mix|blended with a dry film, a liquid epoxy resin is used (for example, patent document 3). When a liquid epoxy resin is contained, the adhesiveness of a dry film is excellent, and it does not crack or a powder falls off. However, when a liquid epoxy resin was contained, when peeling a carrier film from a resin layer, there existed a problem that a resin layer adhered to a carrier film and some or all will peel.

Accordingly, an object of the present invention is to provide a dry film excellent in peelability of a carrier film and having a resin layer that suppresses cracking and powder drop-off, a cured product obtained by curing the dry film, and a printed wiring board comprising the cured product is to provide

As a result of earnest examination in view of the above, the present inventors found that the above problem could be solved by using a semi-solid or solid epoxy resin and blending two solvents having a boiling point of 100° C. or higher and different boiling points. Thus, the present invention was completed.

That is, the dry film of the present invention is a dry film having a resin layer containing a semi-solid or solid epoxy resin, a curing agent or a curing accelerator, a filler, and at least two solvents, wherein the at least two solvents are All are characterized by a boiling point of 100°C or higher and a different boiling point of 5°C or higher. Here, the at least two solvents are preferably at least two selected from the group consisting of methyl isobutyl ketone, propylene glycol monomethyl ether acetate, 3-methoxy-3-methyl butyl acetate and diethylene glycol monoethyl ether acetate. do.

It is preferable that the resin layer of the dry film of this invention further contains the epoxy resin whose epoxy equivalent is 160 or less. Moreover, it is preferable to contain an active ester resin as said hardening|curing agent.

Moreover, it is preferable to contain titanium oxide as said filler. Moreover, it is preferable that the said hardening|curing agent or the said hardening accelerator does not contain a hydroxyl group.

It is preferable that the dry film of this invention is for printed wiring board manufacture.

The hardened|cured material of this invention is obtained by hardening|curing the resin layer of the said dry film, It is characterized by the above-mentioned.

The printed wiring board of this invention is provided with the said hardened|cured material, It is characterized by the above-mentioned.

ADVANTAGE OF THE INVENTION According to this invention, it is excellent in releasability with a carrier film, and provides the dry film which has a resin layer which suppresses cracking and powder fall-off, the hardened|cured material obtained by hardening the said dry film, and the printed wiring board provided with the said hardened|cured material. can do.

BRIEF DESCRIPTION OF THE DRAWINGS It is a partial sectional drawing which shows schematic structure of the multilayer printed wiring board produced by the conventional build-up method.
Fig. 2 is a schematic side view showing two test tubes used for determining the liquid phase of an epoxy resin.

The dry film of this invention is a dry film which has a resin layer containing a semi-solid or solid epoxy resin, a hardening|curing agent or hardening accelerator, a filler, and at least 2 types of solvent, The said at least 2 types of solvents all have boiling points. It is 100 degreeC or more, and a boiling point differs 5 degreeC or more.

When the dry film of this invention contains a semi-solid or solid epoxy resin, peelability with a carrier film improves.

Moreover, when only the solvent whose boiling point is less than 100 degreeC is used, the resin layer of a dry film will dry too much, and a softness|flexibility will worsen, and it will crack or powder fall off.

On the other hand, when only one solvent having a boiling point of 100 ° C. or higher is used, or when two solvents having a boiling point difference of less than 5 ° C are used, the solvent remains excessively even when dried, so when peeling the carrier film, the resin layer is also peeled off Since it is discarded, peelability is inferior. Moreover, it is easy to generate|occur|produce a bubble, and it becomes difficult to form a flat resin layer. Moreover, when it is made to dry at high temperature in order to reduce a residual solvent, in spite of being a drying process, thermosetting will advance too much.

However, by blending a semi-solid or solid epoxy resin and blending two solvents having a boiling point of 100°C or more and a boiling point of 5°C or more different, the peelability with the carrier film is excellent, and cracks and powder drop-off are suppressed. A dry film having a resin layer to be used can be obtained. Moreover, when the dry film of this invention is used, generation|occurrence|production of a bubble is suppressed and it becomes easy to form a flat insulating layer on a circuit board. Hereinafter, each component of the resin layer of the dry film of this invention is demonstrated.

[Epoxy Resin]

The resin layer of the dry film of this invention contains a semi-solid or solid epoxy resin. In addition, the case where the resin layer of this invention contains only any 1 type of a semi-solid or solid epoxy resin may be sufficient, and the case where it contains 2 types of semi-solid and solid epoxy resins may be sufficient as it. In addition, the resin layer may further include a liquid epoxy resin.

An epoxy resin is a compound which has an epoxy group, and can use all conventionally well-known things. The bifunctional epoxy compound which has two epoxy groups in a molecule|numerator, the polyfunctional epoxy compound which has many epoxy groups in a molecule|numerator, etc. are mentioned. Moreover, the hydrogenated bifunctional epoxy compound may be sufficient.

Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, hydrogenated bisphenol A type epoxy resin, brominated bisphenol A type epoxy resin, bisphenol S type epoxy resin, phenol novolak type epoxy resin, cresol novolac Epoxy resin, bisphenol A novolak epoxy resin, biphenyl type epoxy resin, naphthol type epoxy resin, naphthalene type epoxy resin, dicyclopentadiene type epoxy resin, triphenylmethane type epoxy resin, alicyclic epoxy resin, aliphatic Chain epoxy resin, phosphorus-containing epoxy resin, anthracene-type epoxy resin, norbornene-type epoxy resin, adamantane-type epoxy resin, fluorene-type epoxy resin, aminophenol-type epoxy resin, aminocresol-type epoxy resin, alkylphenol-type epoxy resin, etc. this is used These epoxy resins can be used individually by 1 type or in combination of 2 or more types.

In this specification, a solid epoxy resin means an epoxy resin that is solid at 40 ° C., a semi-solid epoxy resin means an epoxy resin that is solid at 20 ° C. and liquid at 40 ° C., and a liquid epoxy resin is 20 ° C. means a liquid epoxy resin.

Judgment of the liquid phase is carried out in accordance with the "Method for Confirmation of Liquid Level" in Attachment 2 of the Ministry of Home Affairs Ordinance No.

(1) device

constant temperature bath:

It is equipped with a stirrer, heater, thermometer, and automatic temperature controller (one that can control the temperature at ±0.1°C), and use one with a depth of 150 mm or more.

In addition, in the judgment of the epoxy resin used in the Examples to be described later, a combination of a low-temperature constant temperature water tank (model BU300) manufactured by Yamato Chemical Co., Ltd. and an input type thermostat (model BF500) was used, and approximately 22 liters of tap water was cooled to a low temperature. Put it in a constant temperature water bath (model BU300), turn on the power of the thermomate (model BF500) attached to it, set it to the set temperature (20°C or 40°C), and set the water temperature to the set temperature ±0.1°C (model BF500). is fine-tuned, but any device that can be adjusted in the same way can be used.

examiner:

As a test tube, as shown in Fig. 2, a flat-bottomed cylindrical transparent glass having an inner diameter of 30 mm and a height of 120 mm, marked lines 31 and 32, respectively, are provided at points of height of 55 mm and 85 mm from the tube bottom, and the test tube The inlet of the test tube with a rubber stopper (33b) having the same size as the test tube for liquid determination (30a) sealed with a rubber stopper (33a) and marked with a mark in the center for inserting and supporting the thermometer in the center is sealed, and a test tube 30b for temperature measurement in which the thermometer 34 is inserted into the rubber stopper 33b is used. Hereinafter, the marked line 55 mm high from the official base is referred to as "Line A", and the marked line 85 mm high from the official base is referred to as "B line".

As the thermometer 34, the one for measuring the freezing point prescribed in JIS B7410 (1982) "Glass thermometer for testing petroleum products" (SOP-58 scale range 20 to 50 ° C) is used, but the temperature range of 0 to 50 ° C can be measured. it should be possible

(2) Procedure of the test

A sample left at a temperature of 20±5°C under atmospheric pressure for 24 hours or more was placed in a test tube 30a for liquid determination shown in FIG. 2A and a test tube 30b for temperature measurement shown in FIG. Insert each up to line A. The two test tubes (30a, 30b) are placed upright in a low-temperature constant temperature water bath so that the B line is below the water surface and left still. The thermometer is made so that the lower end is 30 mm below the A line.

After the sample temperature reaches the set temperature ±0.1°C, it is maintained as it is for 10 minutes. After 10 minutes, the liquid test tube 30a is taken out from the low-temperature constant-temperature water bath, and immediately placed horizontally on a horizontal test bench. record A sample is a set temperature. WHEREIN: The thing whose measured time is less than 90 seconds determines that it is liquid, and what exceeds 90 second determines that it is solid.

As a solid epoxy resin, DIC Corporation HP-4700 (naphthalene type epoxy resin), DIC Corporation EXA4700 (tetrafunctional naphthalene type epoxy resin), Nippon Kayaku Corporation NC-7000 (naphthalene skeleton containing polyfunctional solid epoxy resin), such as naphthalene types epoxy resin; an epoxidized product (trisphenol-type epoxy resin) of a condensate of a phenol and an aromatic aldehyde having a phenolic hydroxyl group, such as EPPN-502H (trisphenol epoxy resin) manufactured by Nippon Kayaku Corporation; Dicyclopentadiene aralkyl type epoxy resins, such as Epiclon HP-7200H (dicyclopentadiene skeleton containing polyfunctional solid epoxy resin) by DIC; Biphenyl aralkyl type epoxy resins, such as Nippon Kayaku Co., Ltd. NC-3000H (biphenyl skeleton containing polyfunctional solid epoxy resin); Biphenyl/phenol novolak-type epoxy resins, such as NC-3000L by Nippon Kayaku Corporation; Novolac-type epoxy resins, such as DIC Corporation Epiclone N660, Epiclone N690, and Nippon Kayaku Corporation EOCN-104S; Biphenyl type epoxy resins, such as YX-4000 by Mitsubishi Chemical Corporation; Phosphorus containing epoxy resins, such as TX0712 by the Shin-Nitetsu Sumikin Chemical company; Tris(2,3-epoxypropyl) isocyanurate, such as TEPIC by Nissan Chemical Industry Co., Ltd., etc. are mentioned.

As semi-solid epoxy resin, DIC Corporation Epiclone 860, Epiclone 900-IM, Epiclone EXA-4816, Epiclone EXA-4822, Asahi Shiba Corporation Araldite AER280, Toto Kasei Corporation Epottoto YD-134, Japan Bisphenol-A epoxy resins, such as jER834 and jER872 by an epoxy resin company, and ELA-134 by Sumitomo Chemical Co., Ltd.; Naphthalene-type epoxy resins, such as Epiclon HP-4032 by DIC; Phenol novolak-type epoxy resins, such as DIC Corporation Epiclon N-740, etc. are mentioned.

Examples of the liquid epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, phenol novolak type epoxy resin, tert-butyl-catechol type epoxy resin, glycidylamine type epoxy resin, aminophenol type epoxy resin An epoxy resin, an alicyclic epoxy resin, etc. are mentioned.

By including a solid epoxy resin or a semi-solid epoxy resin, the glass transition temperature (Tg) is high and the hardened|cured material excellent in crack resistance can be obtained. As an epoxy resin, an aromatic epoxy resin is preferable from a viewpoint, such as preferable physical properties of hardened|cured material. Especially, a naphthalene type epoxy compound and a biphenyl type epoxy compound are more preferable. In addition, in this specification, an aromatic epoxy resin means the epoxy resin which has aromatic ring skeleton in the molecule|numerator.

Moreover, it is preferable that the resin layer of the dry film of this invention contains the epoxy resin whose epoxy equivalent is 160 or less. In particular, by including only an epoxy resin having an epoxy equivalent of 160 or less as the epoxy resin, the glass transition temperature of the cured product is improved, and the cold-heat cycle resistance is improved. As an epoxy resin having an epoxy equivalent of 160 or less, for example, a naphthalene type epoxy resin (manufactured by DIC; epoxy equivalent of 145 to 157 g/eq; semi-solid epoxy resin), a glycidylamine type epoxy resin manufactured by Mitsubishi Chemical Corporation (jER604 (110) to 130 g/eq)), aromatic aminoepoxy resin jER630 (90 to 105 g/eq), aminophenol type epoxy resin jER630LSD (90 to 100 g/eq), triglycidyl isocyanurate TEPIC-G manufactured by Nissan Chemical Industry Co., Ltd. (110 g / eq), TEPIC-S (105 g / eq), TEPIC-SP (105 g / eq), TEPIC-SS (102 g / eq), TEPIC-PASB26 (130 to 145 g / eq), TEPIC-VL (125 to 145 g/eq).

A semi-solid or solid epoxy resin can be used individually by 1 type or in combination of 2 or more types. The blending amount of the semi-solid and solid epoxy resin is preferably 5 to 50% by weight, more preferably 10 to 40% by weight, more preferably 10 to 35% by weight, based on the total amount of the resin layer of the dry film from which the solvent is removed. more preferably.

In addition, when a liquid epoxy resin is blended, the glass transition temperature (Tg) of the cured product is lowered and crack resistance may deteriorate. Therefore, the blending amount of the liquid epoxy resin is 0 to 45% by weight based on the total weight of the epoxy resin. It is preferable, and it is more preferable that it is 0 to 30 weight%, and it is especially preferable that it is 0 to 5 weight%.

Further, when an epoxy resin having an epoxy equivalent weight of 160 or less is included, the blending amount thereof is preferably 1 to 50% by weight, more preferably 5 to 35% by weight, based on the total amount of the resin layer of the dry film from which the solvent is removed.

[hardener]

The resin layer of the dry film of this invention may contain a hardening|curing agent. Examples of the curing agent include phenol resins, polycarboxylic acids and acid anhydrides thereof, cyanate ester resins, active ester resins, and triazine-containing resins. A hardening|curing agent can be used individually by 1 type or in combination of 2 or more type.

Examples of the phenol resin include phenol novolac resin, alkylphenol novolak resin, bisphenol A novolak resin, dicyclopentadiene type phenol resin, Xylok type phenol resin, terpene-modified phenol resin, cresol/naphthol resin, polyvinyl phenol, phenol / Conventionally well-known things, such as a naphthol resin, (alpha)-naphthol skeleton containing phenol resin, and triazine containing cresol novolak resin, can be used individually by 1 type or in combination of 2 or more types.

The polycarboxylic acid and its acid anhydride are a compound having two or more carboxyl groups in one molecule and an acid anhydride thereof, for example, a copolymer of (meth)acrylic acid, a copolymer of maleic anhydride, and a condensate of a dibasic acid In addition to these, resins having a carboxylic acid terminal, such as a carboxylic acid terminal imide resin, may be mentioned.

The said cyanate ester resin is a compound which has two or more cyanate ester groups (-OCN) in 1 molecule. Any conventionally well-known thing can be used for cyanate ester resin. As cyanate ester resin, for example, phenol novolac type cyanate ester resin, alkylphenol novolak type cyanate ester resin, dicyclopentadiene type cyanate ester resin, bisphenol A type cyanate ester resin, bisphenol F type cyanide Nate ester resin and bisphenol S type|mold cyanate ester resin are mentioned. It may also be a prepolymer in which some have been triazinated.

The active ester resin is a resin having two or more active ester groups in one molecule. The active ester resin can generally be obtained by a condensation reaction between a carboxylic acid compound and a hydroxy compound. Especially, the active ester compound obtained using a phenol compound or a naphthol compound as a hydroxy compound is preferable. Examples of the phenolic compound or naphthol compound include hydroquinone, resorcin, bisphenol A, bisphenol F, bisphenol S, phenolphthalline, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m-cresol, and p-cresol. , catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone , tetrahydroxybenzophenone, phloroglucin, benzenetriol, dicyclopentadienyldiphenol, and phenol novolac. In addition, as an active ester resin, a naphthalenediol alkyl/benzoic acid type may be sufficient.

Moreover, as a hardening|curing agent, an alicyclic olefin polymer can also be used. As a specific example of the method for producing an alicyclic olefin polymer, (1) a method of polymerizing an alicyclic olefin having a carboxyl group and/or a carboxylic acid anhydride group (hereinafter referred to as "carboxyl group etc.") together with other monomers as needed , (2) a method of hydrogenating the aromatic ring moiety of a (co)polymer obtained by polymerizing an aromatic olefin having a carboxyl group or the like with other monomers if necessary, (3) an alicyclic olefin having no carboxyl group, and a carboxyl group, etc. A method of copolymerizing a monomer having (4) a method of hydrogenating the aromatic ring moiety of a copolymer obtained by copolymerizing an aromatic olefin having no carboxyl group and the like with a monomer having a carboxyl group, etc., (5) an alicyclic having no carboxyl group, etc. A method of introducing a compound having a carboxyl group or the like into the olefin polymer by a modification reaction, or (6) a carboxylic acid ester group of an alicyclic olefin polymer having a carboxylate ester group obtained as described in (1) to (5) above; For example, the method of converting into a carboxyl group by hydrolysis etc. is mentioned.

Among the curing agents, phenol resins, cyanate ester resins, active ester resins, and alicyclic olefin polymers are preferable.

A hardening|curing agent may combine 2 or more types. For example, cyanate ester resin and active ester resin may be combined, and cyanate ester resin, active ester resin, and phenol resin may be combined. By combining a phenol resin, adhesiveness with a circuit can be improved.

Moreover, it is preferable that a hardening|curing agent does not contain a hydroxyl group. By not including a hydroxyl group, yellowing of white hardened|cured material can be suppressed.

The curing agent includes an epoxy group of a semi-solid or solid epoxy resin (in the case of including both a semi-solid epoxy resin and a solid epoxy resin, the total epoxy groups), and the ratio of functional groups in the curing agent that reacts with the epoxy group , It is preferable to mix|blend in the ratio which becomes functional group/epoxy group (equivalent ratio) =0.2-2 of a hardening|curing agent. By making the functional group/epoxy group (equivalent ratio) of the curing agent within the above range, roughening of the film surface in the desmear process can be prevented. More preferably, the functional group/epoxy group (equivalent ratio) of the curing agent is 0.2 to 1.5, and more preferably, the functional group/epoxy group (equivalent ratio) of the curing agent is 0.3 to 1.0.

[curing accelerator]

The resin layer of the dry film of this invention may contain a hardening accelerator. A hardening accelerator accelerates|stimulates a thermosetting reaction, and it is used in order to improve characteristics, such as adhesiveness, chemical-resistance, and heat resistance further. Specific examples of such a curing accelerator include imidazole and derivatives thereof; guanamines such as acetoguanamine and benzoguanamine; polyamines such as diaminodiphenylmethane, m-phenylenediamine, m-xylenediamine, diaminodiphenylsulfone, dicyandiamide, urea, urea derivatives, melamine, and polybasic hydrazide; these organic acid salts and/or epoxy adducts; amine complexes of boron trifluoride; triazine derivatives such as ethyldiamino-S-triazine, 2,4-diamino-S-triazine, and 2,4-diamino-6-xylyl-S-triazine; Trimethylamine, triethanolamine, N,N-dimethyloctylamine, N-benzyldimethylamine, pyridine, N-methylmorpholine, hexa(N-methyl)melamine, 2,4,6-tris(dimethylaminophenol), tetra amines such as methylguanidine and m-aminophenol; polyphenols such as polyvinylphenol, polyvinylphenol bromide, phenol novolac, and alkylphenol novolac; organic phosphines such as tributylphosphine, triphenylphosphine, and tris-2-cyanoethylphosphine; phosphonium salts such as tri-n-butyl (2,5-dihydroxyphenyl) phosphonium bromide and hexadecyl tributyl phosphonium chloride; quaternary ammonium salts such as benzyltrimethylammonium chloride and phenyltributylammonium chloride; the polybasic acid anhydride; photocationic polymerization catalysts such as diphenyliodonium tetrafluoroboroate, triphenylsulfonium hexafluoroantimonate, and 2,4,6-triphenylthiopyrylium hexafluorophosphate; styrene-maleic anhydride resin; A conventionally well-known hardening accelerator, such as an equimolar reaction product of phenyl isocyanate and dimethylamine, an equimolar reaction product of organic polyisocyanate, such as tolylene diisocyanate and isophorone diisocyanate, and dimethylamine, a metal catalyst, is mentioned. Among the curing accelerators, phosphonium salts are preferred from the viewpoint of obtaining BHAST tolerance.

Moreover, it is preferable that a hardening accelerator does not contain a hydroxyl group. By not including a hydroxyl group, yellowing of white hardened|cured material can be prevented.

A hardening accelerator can be used individually by 1 type or in mixture of 2 or more types. Although the use of a curing accelerator is not essential, 100 parts by weight of a semi-solid or solid epoxy resin (in the case of including both a semi-solid epoxy resin and a solid epoxy resin, a total of them) when specifically to accelerate curing Preferably, it can be used in the range of 0.01 to 10 parts by weight.

In the case of a metal catalyst, 10 to 550 ppm in terms of metal is preferable with respect to 100 parts by weight of a semi-solid or solid epoxy resin (in the case of including both a semi-solid epoxy resin and a solid epoxy resin, the total), 25 to 200 ppm are more preferable.

[Fillers]

The resin layer of the dry film of this invention contains a filler. By containing a filler, the thermal characteristic of a dry film can be improved by matching thermal intensity with conductor layers, such as copper in the periphery of an insulating layer. All conventionally known inorganic fillers and organic fillers can be used as the filler, and although it is not limited to a specific one, an inorganic filler which suppresses cure shrinkage of a coating film and contributes to improvement of characteristics, such as adhesiveness and hardness, is preferable. Examples of the inorganic filler include barium sulfate, barium titanate, amorphous silica, crystalline silica, fused silica, spherical silica, talc, clay, magnesium carbonate, calcium carbonate, aluminum oxide, aluminum hydroxide, silicon nitride, aluminum nitride, titanium oxide, and the like. and metal powders such as extender pigments of copper, tin, zinc, nickel, silver, palladium, aluminum, iron, cobalt, gold, and platinum. Among these inorganic fillers, silica and barium sulfate, which are difficult to be immersed in the roughening solution, are preferable, and spherical silica is preferable from the viewpoint of particularly having a small specific gravity and being able to be blended in a high proportion in the composition and excellent in low thermal expansibility. It is preferable that the average particle diameter of a filler is 3 micrometers or less, More preferably, 1 micrometer or less is preferable. In addition, an average particle diameter can be calculated|required with a laser diffraction type particle diameter distribution measuring apparatus.

Moreover, when titanium oxide is included as a filler, the cured film excellent in reflectance can be formed. In the case of a general dry film, cracks tend to occur when the resin layer contains titanium oxide, and it is considered that the flexibility of the dry film decreases. However, in the dry film of the present invention, since the resin layer contains a specific solvent, the dry film Flexibility is improved, and the occurrence of cracks can be suppressed.

As titanium oxide, the titanium oxide of any one structure of a rutile type, an anatase type, and a Ramsdelite type may be sufficient, and it may be used individually by 1 type, or may be used in combination of 2 or more type. Among these, Ramsdelite-type titanium oxide is Ramsdelite-type Li _{0 .} It is obtained by performing _the lithium desorption process by chemical oxidation to ₅ TiO2.

Among the above, use of rutile-type titanium oxide is preferable because heat resistance can be further improved, discoloration due to light irradiation becomes difficult to occur, and quality can be difficult to deteriorate even in a severe use environment. In particular, heat resistance can be further improved by using a rutile-type titanium oxide surface-treated with aluminum oxide such as alumina. It is also preferable to use a rutile-type titanium oxide surface-treated with silicon oxide, and also in this case, heat resistance can be further improved.

As a filler, the filler whose average coefficient of linear thermal expansion between 30 degreeC and 150 degreeC is 300 ppb/degreeC or less may be sufficient. Specific examples of such fillers include glass fillers such as titanium-doped type fillers, zirconium phosphate-based fillers, cordierite-based fillers, silicon oxide-based fillers, and zirconium tungstates having an average coefficient of linear thermal expansion of 300 ppb/°C or less between 30° C. and 150° C. fillers and manganese nitride-based fillers; and the like. As a commercial item of a titanium-doped glass filler, "AZ Filler" manufactured by Asahi Glass Co., Ltd. As a commercial item of a zirconium phosphate filler, "ZWP" manufactured by Public Materials Co., Ltd. As a commercial item of crushed glass filler, "DL7400" manufactured by Nippon Denki Glass Co., Ltd., etc. are mentioned.

Further, as the filler, a filler having a negative coefficient of thermal expansion may be used. Examples of such fillers include zirconium phosphate (Ultea series manufactured by Toagosei Co., Ltd.), zirconium tungsten phosphate (Zr ₂ (WO ₄ )(PO ₄ ) ₂ , ZWP), LaCu ₃ Fe ₄ O ₁₂ (A Site-Ordered Perovskite Structure Oxide, see Publication No. 2010/101153 in Table), Bi _{1 - x} Ln _x NiO ₃ (Ln=La, Nd, Eu, Dy, perovskite structure oxide), Al ₂ O ₃ ·TiO ₂ (Rotech manufactured by AGC Ceramics Co., Ltd.), Li ₂ O·Al ₂ O ₃ ·nSiO ₂ β spodumene solid solution (Nippon Denki Glass Co., Ltd. Neo Serum), faujasite; Na , Ca _0.5 , Mg _0.5 , K) _x [Al _x Si _{12 - x} O ₂₄ ] 16H ₂ O), LiAlSiO ₄ , PbTiO ₃ , Sc ₂ W ₃ O ₁₂ , Lu ₂ W ₃ O ₁₂ , ZrW ₂ O ₈ , Mn ₃ XN (X=Cu-Sn, Zn-Sn, etc.).

It is preferable that the compounding quantity of a filler is 1-90 weight% based on the resin layer whole quantity from which the solvent was removed of a dry film, It is more preferable that it is 10-90 weight%, It is more preferable that it is 30-80 weight%. When the compounding quantity of a filler is 1 weight% or more, thermal expansion can be suppressed and heat resistance can be improved, On the other hand, when it is 90 weight% or less, the hardness of hardened|cured material improves and generation|occurrence|production of a crack can be suppressed.

[solvent]

The resin layer of the dry film of this invention is 100 degreeC or more in a boiling point, and contains 2 types of solvent from which a boiling point differs 5 degreeC or more. The said solvent is not specifically limited, A conventionally well-known solvent with a boiling point of 100 degreeC or more can be used. In this invention, when the boiling point of a solvent has a width|variety, let the boiling point be the initial flow point - the end point at the time of distillation.

As a solvent with a boiling point of 100 degreeC or more, a ketone type and an ester type are preferable. Specific examples of the solvent include methyl isobutyl ketone, propylene glycol monomethyl ether acetate, 3-methoxy-3-methyl butyl acetate, diethylene glycol monoethyl ether acetate, isobutyl alcohol, toluene, methyl isobutyl ketone, n- Butanol, butyl acetate, 2-methoxypropanol, isobutyl acetate, tetrachloroethylene, ethylene glycol monomethyl ether, methyl butyl ketone, isopentyl alcohol, ethylene glycol monoethyl ether, N,N-dimethylformamide (DMF), Turpentine, cyclohexanone, ethylene glycol monobutyl ether, gamma -butyrolactone, etc. are mentioned.

Further, as a solvent having a boiling point of 100° C. or higher, xylene, petroleum naphtha, Maruzen Sekiyu Chemical Swasol 1000 (C8 to 10: high boiling point aromatic hydrocarbon), Swasol 1500 (high boiling point aromatic hydrocarbon), Standard Seki Solvesso 100 (C 9-10: high boiling point aromatic hydrocarbon) manufactured by Yu Osaka Hatsubisho, Solvesso 150 (C 10-11 high boiling point aromatic hydrocarbon), Solvesso #100 manufactured by Sankyo Chemical, Solvent #150, Shell Chemicals Shellsol A100, Shellsol A150, manufactured by Idemitsu Kosan Corporation, Idemitsu Kosan Corporation, Ipsol No. 100 (a C9 aromatic hydrocarbon is a main component), Ipsol No. 150 (a C10 aromatic hydrocarbon is a main component), etc. are mentioned. It is preferable that a high boiling point aromatic hydrocarbon contains 99 volume% or more of aromatic components. Moreover, it is preferable that benzene, toluene, and xylene each contain less than 0.01 volume% of a high boiling point aromatic hydrocarbon.

The resin layer of the dry film of this invention may contain 3 or more types of solvents whose boiling point is 100 degreeC or more, In that case, what is necessary is just to differ in the boiling points of any 2 types of solvents. Among the solvents with a boiling point of 100 degreeC or more, the solvent whose boiling point is 100-230 degreeC is preferable, and the solvent whose boiling point is 100-220 degreeC is more preferable. When a boiling point is 230 degrees C or less, it is hard to remain|survive a solvent in the resin layer of a dry film after thermosetting or an annealing process. It is more preferable that the solvent of this invention contains any 1 type of methyl isobutyl ketone, propylene glycol monomethyl ether acetate, 3-methoxy-3- methyl butyl acetate, and diethylene glycol monoethyl ether acetate. In particular, at least two solvents of the present invention are at least two selected from the group consisting of methyl isobutyl ketone, propylene glycol monomethyl ether acetate, 3-methoxy-3-methyl butyl acetate and diethylene glycol monoethyl ether acetate. It is preferably a species.

It is preferable that it is 10-150 weight part with respect to 100 weight part of resin layers of the dry film from which the solvent was removed, and, as for the compounding quantity of the solvent before drying, it is more preferable that it is 25-100 weight part. When the compounding quantity of a solvent is 10 weight part or more, solubility improves and adjustment of the amount of residual solvent becomes easy, On the other hand, when it is 150 weight part or less, control of the thickness of a resin layer becomes easy.

It is preferable that the ratio of the solvent compounding quantity after drying, ie, the residual content of a solvent, is 0.1 to 4 weight% based on the resin layer whole quantity of the dry film containing a solvent, and it is more preferable that it is 0.3 to 3 weight%.

The resin layer of the dry film of this invention may contain the solvent whose boiling point is less than 100 degreeC. Examples of the solvent having a boiling point of less than 100°C include diethyl ether, carbon disulfide, acetone, chloroform, methanol, n-hexane, ethyl acetate, 1,1,1-trichloroethane, carbon tetrachloride, methyl ethyl ketone, isopropyl alcohol, trichloro Ethylene, isopropyl acetate, etc. are mentioned.

(thermoplastic resin)

The resin layer of the dry film of this invention may further contain a thermoplastic resin in order to improve the mechanical strength and softness|flexibility of the cured film obtained. It is preferable that a thermoplastic resin is soluble in a solvent. When it is soluble in a solvent, the softness|flexibility of a dry film improves, and generation|occurrence|production of a crack and powder drop-off can be suppressed.

As the thermoplastic resin, various types of acid anhydrides or acid chlorides are used for the thermoplastic polyhydroxypolyether resin, phenoxy resin which is a condensate of epichlorohydrin and various difunctional phenol compounds, or the hydroxyl group of the hydroxyether moiety present in its skeleton. and esterified phenoxy resins, polyvinyl acetal resins, polyamide resins, polyamideimide resins, block copolymers, and the like. A thermoplastic resin can be used individually by 1 type or in combination of 2 or more type.

Polyvinyl acetal resin is obtained by acetalizing polyvinyl alcohol resin with an aldehyde, for example. It does not specifically limit as said aldehyde, For example, formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde etc. are mentioned.

Specific examples of the phenoxy resin include FX280 and FX293 manufactured by Toto Chemical Industries, Ltd., YX8100, YL6954, and YL6974 manufactured by Mitsubishi Chemical.

Specific examples of the polyvinyl acetal resin include S-Rec KS series manufactured by Sekisui Chemical Co., Ltd., KS5000 series manufactured by Hitachi Kasei Kogyo Co., Ltd. as polyamide resins, BP series manufactured by Nippon Kayaku Corporation as polyamide resins, and KS9000 series manufactured by Hitachi Chemical Industries Ltd. as polyamide imide resins. can be heard

When the thermoplastic polyhydroxypolyether resin has a fluorene skeleton, it has a high glass transition point and excellent heat resistance. , the resulting cured film has both a low coefficient of thermal expansion and a high glass transition point in a good balance.

Further, since the thermoplastic polyhydroxypolyether resin has a hydroxyl group, it exhibits good adhesion to the substrate and conductor, and the resulting cured film is difficult to be immersed with the roughening agent. Since it is easy to permeate into an interface, it becomes easy to peel off the filler on the surface of a hardened-film by a roughening process, and it becomes easy to form a favorable roughened surface.

As the thermoplastic resin, a block copolymer may also be used. The block copolymer means a copolymer of a molecular structure in which two or more types of polymers having different properties are linked by a covalent bond to form a long chain.

As the block copolymer, A-B-A type or A-B-A' type block copolymer is preferable. Among the A-B-A type and A-B-A' type block copolymers, B at the center is a soft block and has a low glass transition temperature (Tg), preferably less than 0° C., and both outer sides A or A′ thereof are hard blocks and have a glass transition The temperature (Tg) is high, and it is preferable that it is comprised with the polymer unit, Preferably it is 0 degreeC or more. The glass transition temperature (Tg) is measured by differential scanning calorimetry (DSC).

In addition, among the A-B-A type and A-B-A' type block copolymers, A or A' contains a polymer unit having a Tg of 50°C or higher, and B is a block containing a polymer unit having a glass transition temperature (Tg) of -20°C or lower A copolymer is more preferred.

In addition, among A-B-A type and A-B-A' type block copolymers, it is preferable that A or A' has high compatibility with a semi-solid or solid epoxy resin, and B has high compatibility with a semi-solid or solid epoxy resin. Low is preferable. As described above, it is thought that a specific structure in the matrix is easily exhibited by using a block copolymer in which the blocks at both ends are compatible with the matrix and the central block is incompatible with the matrix.

Among the thermoplastic resins, a phenoxy resin, a polyvinyl acetal resin, a thermoplastic polyhydroxy polyether resin having a fluorene skeleton, and a block copolymer are preferable.

The blending amount of the thermoplastic resin is 1 to 30 parts by weight, preferably 1 to 30 parts by weight, based on 100 parts by weight of a semi-solid or solid epoxy resin (when both a semi-solid epoxy resin and a solid epoxy resin are included, their total) A proportion of 25 parts by weight is preferred. A uniform roughened surface state can be obtained easily that the compounding quantity of a thermoplastic resin is in the said range.

(rubber-like particles)

The resin layer of the dry film of this invention can contain rubber-like particle|grains further as needed. Examples of such rubbery particles include polybutadiene rubber, polyisopropylene rubber, urethane-modified polybutadiene rubber, epoxy-modified polybutadiene rubber, acrylonitrile-modified polybutadiene rubber, carboxyl group-modified polybutadiene rubber, acrylonitrile modified with carboxyl group or hydroxyl group. butadiene rubber, cross-linked rubber particles thereof, core-shell rubber particles, and the like, may be used alone or in combination of two or more thereof. These rubber-like particles are added to improve the flexibility of the resulting cured film, to improve crack resistance, or to enable surface roughening treatment with an oxidizing agent to improve adhesion strength with copper foil or the like.

The range of 0.005-1 micrometer is preferable and, as for the average particle diameter of rubber-like particle|grains, the range of 0.2-1 micrometer is more preferable. The average particle diameter of the rubber-like particle|grains in this invention can be measured using a dynamic light scattering method. For example, the rubber particles are uniformly dispersed in a suitable organic solvent by ultrasonic waves or the like, and the particle size distribution of the rubber particles is prepared by weight using FPRA-1000 (manufactured by Otsuka Electronics Co., Ltd.), and the median diameter thereof is calculated It can measure by setting it as an average particle diameter.

The compounding amount of the rubber-like particles is preferably 0.5 to 20 parts by weight with respect to 100 parts by weight of a semi-solid or solid epoxy resin (in the case of including both a semi-solid epoxy resin and a solid epoxy resin, the total), 1 It is more preferable that it is -15 weight part. When it is 0.5 part by weight or more, crack resistance is obtained and adhesive strength with a conductor pattern etc. can be improved. When the amount is 20 parts by weight or less, the coefficient of thermal expansion (CTE) decreases, the glass transition temperature (Tg) increases, and the curing properties are improved.

(Other ingredients)

The resin layer of the dry film of the present invention, if necessary, a conventionally known colorant such as phthalocyanine blue, phthalocyanine green, iodine green, disazo yellow, crystal violet, carbon black, naphthalene black, asbestos, oro Conventionally known thickeners such as ben, bentone, and finely divided silica; antifoaming and/or leveling agents such as silicone, fluorine, and polymer; adhesion-imparting agents such as thiazole, triazole, and silane coupling agents; flame retardant; titanate; aluminum Conventionally known additives of the system can be further used.

The dry film of this invention can be manufactured by apply|coating, drying, and laminating a protective film as needed on a carrier film, the thermosetting resin composition for forming a resin layer.

As a material of a carrier film, polyethylene terephthalate (PET) can be used suitably, In addition, polyolefins, such as polyethylene, polypropylene (PP), polyvinyl chloride, polyesters, such as polyethylene terephthalate and polyethylenenaphthalate, poly Carbonate, polyimide, and also metal foil like a release paper, copper foil, aluminum foil, etc. are mentioned. In addition, the carrier film may be given a mold release treatment other than a mud treatment and a corona treatment. The thickness of the carrier film is suitably from 8 to 60 mu m.

As a material of a protective film, the thing similar to what is used for a carrier film can be used, It is PET or PP suitably. The thickness of a protective film is 5-50 micrometers suitably.

Here, as a coating method of a thermosetting resin composition, well-known methods, such as a screen printing method, can be used. In addition, as a volatilization drying method, the well-known method using a hot-air circulation type drying furnace etc. can be used.

Moreover, the printed wiring board of this invention is provided with the hardened|cured material obtained by hardening|curing the dry film of this invention. Although the manufacturing method is demonstrated below, it is not limited to this.

The dry film of this invention apply|coated the thermosetting resin composition on the carrier film, and dried the solvent. Here, a thermosetting resin composition contains a semi-solid or solid epoxy resin, a hardening|curing agent or hardening accelerator, a filler, and said at least 2 types of solvent.

After peeling a protective film from the dry film of this invention, the hardened|cured material of this invention heat-laminates the dry film of this invention on the inner-layer circuit board in which the circuit was formed, and is integrally molded. Then, the hardened|cured material of this invention is obtained by hardening in oven or hardening by a hot platen press.

The lamination or hot plate press method in the above process is preferable because the fine unevenness caused by the inner layer circuit is resolved when heated and melted and hardened as it is, so that a multilayer plate with a flat surface is finally obtained. Moreover, when laminating or hot-plate-pressing the base material with an inner-layer circuit and the dry film of this invention, copper foil or the base material with a circuit can also be laminated|stacked simultaneously.

After laminating|stacking a thermosetting resin composition on a circuit board, an insulating layer can be formed on a circuit board by thermosetting a resin layer. The thermosetting conditions may be appropriately selected depending on the type, content, etc. of the resin component in the resin layer, but preferably at 150° C. to 220° C. for 20 to 180 minutes, more preferably at 160° C. to 210° C. for 30 to 120 minutes. is selected from the range of Moreover, by thermosetting without peeling a carrier film, adhesion of foreign substances, such as dust and dirt, can be prevented.

A hole is punched in the substrate obtained in this way with a semiconductor laser such as a CO ₂ laser or UV-YAG laser, or a drill. The hole may be either a through hole (through hole) for the purpose of conducting the outside and the inside of the substrate, or a partial hole (conformal via) for the purpose of connecting the resin layer and the resin layer layer. have. The peeling of a carrier film may be either before and behind a laser processing. When the carrier film is peeled off before laser processing, the processing diameter according to the design value of the laser mask diameter (aperture diameter) is easily obtained, and since there is no carrier film, the resin layer can be processed with low power. On the other hand, when the carrier film is peeled off after laser processing, debris (resin fragments) generated during processing and damage to the surface of the resin layer due to laser light can be suppressed.

After drilling, removing the residue (smear) on the inner wall or bottom of the hole, and forming a roughened surface of fine concavo-convex shape on the surface in order to express the anchor effect of the conductor layer (metal plating layer to be formed thereafter) For this purpose, it is carried out simultaneously with a commercially available desmear solution (coargument agent) or a roughening solution containing an oxidizing agent such as permanganate, dichromate, ozone, hydrogen peroxide/sulfuric acid, or nitric acid. When smear removal is performed in the state to which the carrier film adhered, the damage on the surface of the resin layer by desmear can be suppressed.

Then, after forming the film surface of the hardened|cured material which produced the hole which removed the residue with the desmear liquid, and the fine grooving|roughness-like roughened surface, a circuit is formed by a subtractive method, a semi-additive method, etc. In either method, after electroless plating or electroplating, or after performing both plating, heat treatment called annealing at about 80 to 180°C for about 10 to 60 minutes is performed for the purpose of stress removal and strength improvement of the metal. can also be carried out.

There is no restriction|limiting in particular as metal plating used here, such as copper, tin, solder, nickel, A plurality of metal platings may be used in combination. In addition, it is also possible to substitute metal sputtering or the like in place of the plating used here.

The dry film of this invention can be used suitably for manufacture of a printed wiring board. In particular, it can use suitably for formation of permanent insulating layers of printed wiring boards, such as an interlayer insulating layer, a coverlay, and a soldering resist layer. A wiring board can also be formed by bonding wiring using the dry film of this invention. Moreover, it can use suitably also as sealing resin for semiconductor chips.

[Example]

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples of the present invention, but it goes without saying that the present invention is not limited to the following Examples. In addition, in the following, "part" and "%" are all based on weight, unless otherwise indicated.

(Examples 1 to 12 and Comparative Examples 1 to 3)

Each component was blended with the formulation shown in Tables 1 and 2 below, kneaded and dispersed, and the resin composition obtained by adjusting the viscosity to 0.5 to 20 dPa·s (rotational viscometer 5 rpm, 25° C.) was dried using a bar coater, respectively. It apply|coated to the carrier film (PET film; Lumirer 38R75 by Toray Corporation: 38 micrometers in thickness) so that the film thickness of a film might be set to 40 micrometers after drying. Then, it dried at the time and temperature shown in following Tables 3 and 4, the protective film was laminated|stacked, and the dry film was obtained.

*1: Biphenyl/phenol novolak type epoxy resin (manufactured by Nippon Kayaku Corporation; epoxy equivalent 272 g/eq; softening point 52° C.)

*2: tetramethylbiphenyl type epoxy resin (manufactured by Mitsubishi Chemical; epoxy equivalent 180 to 192 g/eq; softening point 105°C)

*3: Bisphenol A type epoxy resin (manufactured by Mitsubishi Chemical Corporation; epoxy equivalent 450 to 500 g/eq)

*4: Triglycidyl isocyanurate type epoxy resin (manufactured by Nissan Chemical Industries, Ltd.; epoxy equivalent 105 g/eq; softening point 95 to 125°C)

*5: naphthalene type epoxy resin (manufactured by DIC; epoxy equivalent 145 to 157 g/eq; semi-solid)

*6: Phenol novolak type epoxy resin (manufactured by Dow Chemical Corporation; epoxy equivalent of 176 to 181 g/eq)

*7: α-naphthol skeleton-containing phenol resin (manufactured by DIC; hydroxyl equivalent: 150 g/eq; softening point 110 to 140° C.)

*8: active ester compound (manufactured by DIC; active ester equivalent 145 g/eq)

*9: Bisphenol A dicyanate (manufactured by Lonza Japan; cyanate equivalent 232 g/eq)

*10: phenol novolak type polyfunctional cyanate ester (manufactured by Lonza Japan; cyanate equivalent 124 g/eq)

*11: 4-methylhexahydrophthalic anhydride / hexahydrophthalic anhydride = 70/30 (manufactured by New Nippon Rika Corporation)

*12: Fluorene + tetramethylbiphenyl skeleton-containing phenoxy resin (manufactured by Toto Kasei Kogyo Co., Ltd.; glass transition temperature 163°C)

*13: polyvinyl acetoacetal (manufactured by Sekisui Chemical Co., Ltd.; glass transition temperature 107°C)

*14: Core shell rubber particles (manufactured by Aika Kogyo Co., Ltd.)

*15: phosphorus compound having a phenolic hydroxyl group (manufactured by Sanko Corporation)

*16: spherical silica (manufactured by Admatex, average particle diameter 0.5 µm)

*17: Titanium oxide (manufactured by Ishihara Sangyo)

*18: 2-ethyl-4-methylimidazole (manufactured by Shikoku Kasei Kogyo Co., Ltd.)

*19: 4-aminopyridine (manufactured by Koe Chemical Co., Ltd.)

*20: Zinc (II) naphthenate mineral spirit (manufactured by Wako Junyaku Kogyo Co., Ltd.; zinc content 8%)

*21: 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine (manufactured by Shikoku Kasei Kogyo Co., Ltd.)

*22: Toluene (boiling point 110°C)

*23: methyl isobutyl ketone (boiling point 116° C.)

*24: propylene glycol monomethyl ether acetate (boiling point 145°C)

*25: cyclohexanone (boiling point 150°C)

*26: DMF (N,N-dimethylformamide; boiling point 153°C)

*27: ifsol 150 (boiling point 184 to 205 ° C.)

*28: 3-methoxy-3-methylbutyl acetate (manufactured by Kurare Corporation; boiling point 188° C.)

*29: diethylene glycol monoethyl ether acetate (boiling point 218°C)

*30: Hexane (boiling point 69°C)

The dry films of Examples 1-12 and Comparative Examples 1-3 were evaluated by the evaluation method shown below. The evaluation results are shown in Tables 3 and 4.

<Measurement of residual content (%) of organic solvent in dry film>

After peeling the carrier film and the protective film from the dry films of each Example and Comparative Example, about 1.2 g of the resin layer was collected, placed in a container with an airtight stopper, and the mass of the collected resin layer was accurately weighed (W). One drop of ethyl 3-ethoxypropionate was added as an internal standard substance to this container with a pipette, and the mass (We) was accurately weighed. Thereafter, 5 ml of acetone was added with a hole pipette, the stopper was closed, and the container was sufficiently shaken to dissolve the collected resin layer. Subsequently, this solution was filtered with a filter having a scale of 0.5 µm, the composition of the filtrate was analyzed by gas chromatography (TRACEGCULTRA manufactured by Thermo Fisher Scientific), and the mass of the organic solvent with respect to 1 g of the internal standard substance was determined from a separately created calibration curve. saved (Ws). From these, the residual content of the organic solvent was calculated according to the following formula.

Residual content of organic solvent (mass %) = (We × Ws/W) × 100

In addition, the measurement conditions in gas chromatography are as follows. Column: Capillary column DB-1MS (30 m x 0.25 mm) manufactured by Agilent Technologies, Detector: MS (ITQ900), Carrier gas: Helium, Injector temperature: 300 ° C., Detector temperature: 230 ° C., Column temperature conditions : Initial temperature of 50°C, after sample injection, hold at 50°C for 2 minutes, increase the temperature to 300°C at 10°C/min, and hold for 10 minutes after reaching 300°C.

<Flexibility of dry film (bending test)>

In accordance with JISK5600-5-1 (ISO1519), using a cylindrical mandrel bending tester manufactured by BYK-Gardner (Gardner), cracks in the dry films of Examples and Comparative Examples and the mandrel in which peeling from the carrier film begins to occur From the minimum diameter of , the hardness of the dry film was evaluated. The evaluation criteria are as follows. When the hardness of the dry film is good, the flexibility of the resin layer is high, and cracks and powder drop-off can be suppressed.

(circle): There was no generation|occurrence|production of the crack of a resin layer and peeling of a carrier film in the range of more than phi 2 mm and less than 5 mm. There was no powder fall-off of the resin layer. Moreover, even if it was a diameter of (phi) 2 mm or less, there was no crack of a resin layer, powder fall-off, and peeling generation|occurrence|production of a carrier film did not exist.

(triangle|delta): In the range of more than phi 2 mm and less than 5 mm, the crack of a resin layer, powder fall-off, and peeling of a carrier film generate|occur|produced.

x: In the diameter of phi 5 mm or more, the crack of a resin layer, powder fall-off, and peeling of a carrier film generate|occur|produced.

<Residual air bubbles>

After peeling the protective film for the dry film of each Example and the comparative example, using the batch type vacuum pressure laminator MVLP-500 (made by Meiki Corporation), 35 micrometers of copper conductor thickness, L (line: wiring width)/S It laminated on the comb-tooth pattern of (space: space|interval width) =100/100 micrometer. Heat lamination was carried out under the conditions of 5 kgf/cm 2 , 180° C., 1 minute, and 1 Torr, followed by leveling under the conditions of 10 kgf/cm 2 , 180° C., 1 minute with a hot plate press. After lamination, it was confirmed at 20 locations whether or not air was drawn into the boundary between the line and the space and a hole (void) was generated in the resin layer. The evaluation criteria are as follows. When a resin layer is sticky, ie, when the peelability of the following carrier film is bad, a bubble enters between a resin layer and a comb-tooth pattern, and a void increases. In that case, it becomes easy to generate|occur|produce a crack.

○: Void not confirmed

△: voids in 1 to 4 places were confirmed

×: Voids in 5 or more places were confirmed

<Peelability of carrier film>

After laminating the dry film of each Example and the comparative example under the same conditions as the said bubble retention test, the carrier film was peeled, and it was visually judged whether the resin composition derived from the resin layer adhered to the carrier film. The evaluation criteria are as follows.

○: The resin composition does not adhere to the carrier film

△: A little resin composition was adhered to the carrier film

×: Many resin compositions were adhered to the carrier film

<Glass transition temperature (Tg) and coefficient of thermal expansion (CTE(α1))>

For each of the resin compositions of Examples and Comparative Examples, a dry film was laminated on the glossy side (copper foil) of GTS-MP foil (manufactured by Furukawa Circuit Foil), and the resin layer was heated at 180° C. in a hot air circulation drying furnace for 60 minutes. hardened. Then, after peeling hardened|cured material from copper foil, the sample was cut out to the measurement size (size of 3 mm x 10 mm), and it used for TMA6100 by the Seiko Instruments company. The TMA measurement was performed by heating the sample from room temperature to 250°C at a temperature increase rate of 10°C/min, and measuring the glass transition temperature (Tg) and the coefficient of thermal expansion (CTE(α1)) in the region below Tg.

<Solder heat resistance>

Dry films of Examples and Comparative Examples were heated and laminated at 5 kgf/cm 2 , 180° C., 1 minute and 1 Torr on copper of a copper clad laminate using a batch vacuum pressurized laminator MVLP-500 (manufactured by Makey). , followed by leveling under the conditions of 10 kgf/cm 2 , 180° C., and 1 minute with a hot plate press machine. Then, the carrier film was peeled, it heated at 180 degreeC for 60 minute(s) in a hot-air circulation type drying furnace, the resin layer was hardened, and the board|substrate for the test which formed the cured film was obtained. The obtained test board|substrate was immersed 5 times for 10 second in a 260 degreeC solder bath so that a cured film might contact solder, Then, it stood to cool to room temperature. The obtained test board|substrate was observed with the naked eye and an optical microscope, and the degree of swelling and peeling of a cured film was confirmed. When the solubility of the thermoplastic resin to a solvent is poor, swelling and peeling of the cured film occur.

○: No swelling and peeling of the cured film

×: Swelling and peeling of the cured film occurred

<Cooling/heating cycle (crack suppression)>

The dry film thickness (resin thickness of 40 µm) of each Example and Comparative Example was measured using a batch vacuum pressure laminator MVLP-500 (manufactured by Meiki Corporation) on copper of a copper clad laminate at 5 kgf/cm 2 , 120° C., 1 minute, It was laminated under the condition of 1 Torr. Then, the carrier film was peeled, and it heated at 180 degreeC for 30 minute(s) in a hot-air circulation type drying furnace, the resin layer was hardened, and the cured film was obtained. Then, via formation was performed in the cured film so that it might become 65 micrometers in top diameter and 50 micrometers in bottom diameter using _the CO2 laser processing machine (made by Hitachi Via Mechanics).

Subsequently, the cured film on which the via was formed was treated in the order of commercially available wet permanganate desmear (manufactured by ATOTECH), electroless copper plating (through cup PEA, manufactured by Uemura Kogyo Co., Ltd.), and electrolytic copper plating treatment. , and a copper plating treatment was performed so as to fill a via portion with a copper thickness of 25 µm on the cured film. Then, it hardened|cured at 190 degreeC for 60 minute(s) in the hot-air circulation type drying furnace, and the test board|substrate which gave the copper plating process which was fully hardened was obtained.

The obtained test board|substrate was made into one cycle for 30 minutes at -65 degreeC and 30 minutes at 150 degreeC, and the heat history was applied. After 2000 and 3000 cycles, in order to observe the state of the bottom of the via or the wall surface with an optical microscope, the center of the via was cut and polished with a precision cutter, and the state of the cross section was observed. The evaluation criteria evaluated according to the following. The number of observation vias was set to 100 holes.

◎: No cracks for both 3000 and 2000 cycles

○: Crack occurrence rate less than 1 to 5% at 3000 cycles, no crack generation at 2000 cycles

Δ: Crack occurrence rate of 5 to less than 15% at 3000 cycles, and crack occurrence rate of 1 to less than 10% at 2000 cycles

×: Crack occurrence rate of 15% or more at 3000 cycles, crack occurrence rate of 10% or more at 2000 cycles

<BHAST resistance>

The dry film was laminated on the BT substrate on which the comb-shaped electrode (line/space = 20 micrometers/15 micrometers) was formed, and it heated at 180 degreeC for 60 minutes, the cured film of the resin layer was formed, and the evaluation board|substrate was produced. The evaluation board|substrate was put into the high-temperature, high-humidity tank in 130 degreeC and the atmosphere of 85% of humidity, the voltage 5.5V was charged, and the BHAST test in a tank was performed for various time. The insulation resistance value in the tank at the time of the lapse of various time of the cured film was evaluated according to the following judgment criteria.

◎: After 300 hours, 10 ⁸ Ω or more

○: After 240 hours, 10 ⁸ Ω or more

△: After 200 hours, 10 ⁸ Ω or more

×: Less than 10 ⁸ Ω after 200 hours

<Solubility of thermoplastic resin in solvent>

The solubility with respect to the solvent of the thermoplastic resin contained in the dry film of each Example and a comparative example was investigated as follows. The evaluation results are shown in Tables 3 and 4.

The solvents used by each Example and the comparative example were mixed in the ratio same as the ratio of Tables 1 and 2, and the mixed solvent was produced. Each of the thermoplastic resins used in Examples and Comparative Examples was dissolved in the above mixed solvent as follows.

1) FX-293:

60 parts of mixed solvents were mix|blended with respect to 40 parts of FX-293, and it heated and melt|dissolved at the temperature lower than the boiling point of each component, stirring.

2) KS-1:

60 parts of a mixed solvent was blended with respect to 30 parts of KS-1, and dissolved by heating at a temperature lower than the boiling point of each component while stirring.

After heating and dissolving the mixture of each thermoplastic resin and mixed solvent, it cooled to room temperature, and produced the film with a thickness of 1 mm. The produced film was observed at 25 times with an optical microscope, and it was confirmed whether a solid material precipitated in the range of 1 cm x 1 cm.

(circle): Coarse particle|grains of 20 micrometers or more were not seen at all.

x: One or more coarse particles of 20 µm or more were observed.

In Examples and Comparative Examples containing a plurality of thermoplastic resins, in the same manner as above, precipitation of solids was confirmed for each thermoplastic resin, and when no coarse particles of 20 μm or more were observed at all for all the thermoplastic resins contained, “○” , when one or more coarse particles of 20 µm or more were observed with respect to at least one type of thermoplastic resin containing it, it was evaluated as "x". In the case of "x", the softness|flexibility of a film worsens.

<Reflectance>

Each component is blended with the formulation shown in Examples 4 to 9 and 12, kneaded and dispersed, and the obtained resin composition is adjusted to a viscosity of 0.5 to 20 dPa·s (rotational viscometer 5 rpm, 25° C.), 150 mm × 75 mm It applied to a glass plate so that the film thickness might be set to 40 micrometers using the bar coater, respectively. Thereafter, this was dried at 90° C. for 10 minutes to form a coating film, and the reflectance of the coating film was measured at 420 nm using a duster (V-670 ILN-725 type manufactured by JASCO), and this measurement The value was taken as the initial value. And then, the said coating film was heated at 180 degreeC for 60 minute(s) in a hot-air circulation type drying furnace, and the hardened|cured material of each composition was formed. The reflectance of the hardened|cured material after the said heating was measured on the conditions similar to the measurement of an initial value.

(circle): The reflectance shows 87 or more of both an initial value and hardened|cured material.

(triangle|delta): The hardened|cured material shows 80 or more and less than 87 with respect to what an initial value shows 87 or more of reflectance.

*31: When the carrier film was peeled after lamination, since a large amount of resin derived from the resin layer adhered to the carrier film, the characteristic test could not be performed.

From the results shown in Tables 3 and 4, it can be seen that, in the case of the dry films of Examples 1 to 12, it is possible to obtain a resin layer having excellent peelability with a carrier film and suppressing cracking and powder drop-off. Moreover, in Examples 4-8 using the hardening|curing agent which does not have a hydroxyl group, it turns out that a reflectance is high. Moreover, in Examples 10-12 using the epoxy resin whose epoxy equivalent is 160 or less, it turns out that cold-heat cycle resistance improves.

1 Insulation substrate
3 Inner layer conductor pattern
3a connection part
4, 9 resin insulating layer
8 Outer layer conductor pattern
10 Outermost layer conductor pattern
20 through hole
21 through hole hole
22 connection part
30a liquid test tube
30b temperature test tube
31 Marked Line (A Line)
32 mark (line B)
33a, 33b rubber stopper
34 thermometer
X laminated board

Claims (8)

A dry film having a resin layer containing a semi-solid epoxy resin and a solid epoxy resin, a curing agent or a curing accelerator, a filler, and at least two solvents,
All of the at least two solvents have a boiling point of 100° C. or higher, and a boiling point different from each other by 5° C. or higher, and the solvent is methyl isobutyl ketone, propylene glycol monomethyl ether acetate, 3-methoxy-3-methylbutyl acetate, and A dry film comprising any one of diethylene glycol monoethyl ether acetate. The at least two solvents according to claim 1, wherein the at least two solvents are selected from the group consisting of methyl isobutyl ketone, propylene glycol monomethyl ether acetate, 3-methoxy-3-methylbutyl acetate and diethylene glycol monoethyl ether acetate. Two types of dry film. The dry film of claim 1, wherein the resin layer further comprises an epoxy resin having an epoxy equivalent of 160 or less. The dry film according to claim 1, comprising an active ester resin as the curing agent. The dry film according to claim 1, comprising titanium oxide as the filler. The dry film according to any one of claims 1 to 5, wherein the curing agent or the curing accelerator does not contain a hydroxyl group. Hardened|cured material obtained by hardening|curing the resin layer of the dry film in any one of Claims 1-5. A printed wiring board comprising the cured product according to claim 7.

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