JP7001866B1 - A method for manufacturing a photosensitive dry film and a printed wiring board using a photosensitive dry film. - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive dry film capable of obtaining a photocurable film having a matte appearance, which is excellent in insulation reliability and resolution. A support film having a first main surface and a second main surface facing the first main surface, and a photosensitive resin layer provided on the first main surface are provided. A photosensitive dry film, wherein the first main surface has an uneven surface formed by chemical etching. [Selection diagram] None

Description

INDUSTRIAL APPLICABILITY The present invention uses a coating material, particularly a photosensitive dry film and a photosensitive dry film capable of forming a coating material having a matte appearance and excellent resolution and insulation reliability, to form a coating material. It relates to a method of manufacturing a wiring board.

A circuit pattern of a conductor (for example, copper foil) is formed on a printed wiring board using a rigid board, a flexible printed wiring board using a flexible board, and the like. Electronic components are mounted on the soldered lands of this circuit pattern by soldering, and the circuit portion excluding the soldered lands is covered with an insulating film (for example, a solder resist film) as a protective film. As the insulating protective film, a photocurable film of a photosensitive resin composition containing a photosensitive resin and a photopolymerization initiator may be used.

Further, as a method of forming the insulating protective film on the substrate, a photosensitive dry film may be used. The photosensitive dry film is formed by applying a photosensitive resin composition to a resin support film such as polyethylene terephthalate to form a coating film, and drying the coating film to form a solder resist layer on the support film. Later, it can be manufactured by laminating a cover film on the formed solder resist layer. A solder resist layer is formed on the printed wiring board by bonding the solder resist layer and the printed wiring board while peeling off the cover film of the photosensitive dry film. After that, the solder resist layer is photo-cured by exposing it to ultraviolet rays from the support film, and then further heat-cured to form an insulating protective film on the printed wiring board.

On the other hand, the insulating protective film of the photosensitive resin composition may be required to have a matte appearance depending on the conditions of use as a protective film such as imparting a high-class feeling. In order to form an insulating protective film having a matte appearance using a photosensitive dry film, the support film of the photosensitive dry film is roughened, and the support film subjected to the roughening is photosensitive. By applying the leather resin composition, the surface roughness is transferred to the surface of the insulating protective film.

As a conventional technique for transferring surface roughness to the surface of an insulating protective film, a photosensitive dry film for forming a solder resist layer comprising a support film and a photosensitive resin layer provided on one surface of the support film. Therefore, a photosensitive dry film having an arithmetic average surface roughness Ra of 100 to 390 nm on the surface side of the support film on which the photosensitive resin layer is provided has been proposed (Patent Document 1). In Patent Document 1, a thermoplastic resin film (a kneaded matte film in which a filler is kneaded into a thermoplastic resin) obtained by forming a resin composition containing a thermoplastic resin and a filler as a support film is used. It is preferable to do so.

However, in the support film made of the resin composition containing the filler, the rough surface state of the surface of the support film may not be sufficiently uniform. When an insulating protective film having a matte appearance is formed by using a support film in which the rough surface condition of the surface is not sufficiently uniform, the rough surface condition of the insulating protective film surface is not sufficiently uniformed and is sufficiently matted. In some cases, an insulating protective film having an appearance could not be obtained. Further, if the rough surface condition of the surface of the support film is not sufficiently uniform, the uneven haze of the support film causes diffuse reflection of light during exposure, and the light halation causes the portion of the coating film to be removed by development. However, it may not be possible to improve the resolution of the pattern of the insulating protective film because it is photo-cured. In addition, the non-uniform surface of the insulating protective film may reduce the insulation reliability of the insulating protective film.

It has also been proposed to obtain a matte appearance of a photocurable film by using a support film in which a support film and an intermediate layer are integrated by coating one side of the film (Patent Document 2). In Patent Document 2, the intermediate layer formed by the coating treatment is a roughening agent, and the action of the intermediate layer gives the photocured film a matte appearance.

However, in Patent Document 2, since the intermediate layer is formed on the support film, the light irradiated at the time of exposure is diffusely reflected by the support film due to the haze caused by the intermediate layer, so that the pattern of the insulating protective film is used. In some cases, it was not possible to achieve high resolution.

It has also been proposed to form a rough surface on the surface of the support film by blasting the surface of the support film. However, when the blasted support film is used, the insulating protective film is contaminated by the blast material remaining on the surface of the support film during the blasting treatment, and the insulating protective film having high resolution cannot be obtained. Further, there is a problem that the insulation reliability may be reduced.

Japanese Unexamined Patent Publication No. 2016-27363 Japanese Unexamined Patent Publication No. 2018-116255

In view of the above circumstances, it is an object of the present invention to provide a photosensitive dry film capable of obtaining a photocurable film having a matte appearance, which is excellent in insulation reliability and resolution.

The gist of the structure of the present invention is as follows.
[1] Photosensitivity comprising a support film having a first main surface and a second main surface facing the first main surface, and a photosensitive resin layer provided on the first main surface. It is a sex dry film
A photosensitive dry film having an uneven surface formed by chemical etching on the first main surface.
[2] The photosensitive dry film according to [1], wherein the arithmetic average surface roughness Sa of the uneven surface of the first main surface is 0.10 μm or more and 1.00 μm or less.
[3] The photosensitive dry film according to [1] or [2], wherein the second main surface does not have an uneven surface formed by chemical etching.
[4] The photosensitive resin layer according to any one of [1] to [3], wherein the photosensitive resin layer is formed of a photosensitive resin composition, and the photosensitive resin composition contains an aliphatic urea compound. Sex dry film.
[5] The photosensitive resin composition comprises (A) a photosensitive resin, (B) an epoxy compound, (C) an aliphatic urea compound, (D) a reactive diluent, and (E) photopolymerization. The photosensitive dry film according to [4], which contains an initiator.
[6] The photosensitive dry film according to [5], wherein the (B) epoxy compound contains at least one selected from the group consisting of a bisphenol A type epoxy resin, a biphenyl type epoxy resin and an alicyclic epoxy resin.
[7] The photosensitive dry film according to any one of [1] to [6] for forming a solder resist film.
[8] The step of bonding the photosensitive resin layer of the photosensitive dry film according to any one of [1] to [7] to the printed wiring board.
A step of photocuring the photosensitive resin layer by irradiating ultraviolet rays from the support film of the photosensitive dry film.
A step of peeling the support film from the photosensitive dry film and developing the photocured photosensitive resin layer to form a photocurable film having a predetermined pattern.
It comprises a step of thermally curing the photocurable film having a predetermined pattern to form a cured film having an uneven surface portion.
A method for manufacturing a printed wiring board in which the arithmetic average surface roughness Sa of the uneven surface portion of the cured film is 0.10 μm or more and 1.00 μm or less.

In the present specification, "arithmetic mean surface roughness Sa" means a value measured according to ISO 25178.

According to the aspect of the photosensitive dry film of the present invention, the photosensitive resin layer is provided on the first main surface of the support film having the uneven surface formed by chemical etching, so that the insulation reliability and solution can be obtained. It is possible to obtain a photocurable film having an excellent image quality and a matte appearance.

According to the aspect of the photosensitive dry film of the present invention, the arithmetic average surface roughness Sa of the uneven surface is 0.10 μm or more and 1.00 μm or less, so that the insulation reliability and the resolution are further excellent, and the gloss is further improved. A photocurable film having an erasable appearance can be obtained.

According to the aspect of the photosensitive dry film of the present invention, the photosensitive resin layer is formed of the photosensitive resin composition containing an aliphatic urea compound, so that the photocurable film has a more reliable matte appearance. Can be obtained.

<Photosensitive dry film>
The details of the photosensitive dry film of the present invention will be described below. The photosensitive dry film of the present invention includes a support film having a first main surface and a second main surface facing the first main surface, and a photosensitive resin layer provided on the first main surface. A photosensitive dry film comprising the above, wherein the first main surface has an uneven surface formed by chemical etching. The first main surface of the support film has an uneven surface formed by chemical etching, and a photosensitive resin layer is coated on the first main surface having the uneven surface.

[Support film]
The support film has a role of supporting the photosensitive resin layer and imparting a predetermined surface morphology to the surface of the photosensitive resin layer in contact with the support film when the photosensitive resin layer is exposed.

The support film has a thin film shape. The support film has a first main surface (front side surface portion) that forms the plane direction of the support film and a second main surface (back side surface portion) that forms the plane direction of the support film and faces the first main surface. ), And a side surface portion that connects the first main surface and the second main surface and forms the thickness direction of the support film.

Of the first main surface and the second main surface forming the plane direction of the support film, only the first main surface is roughened to form an uneven surface. The first main surface is subjected to chemical etching (chemical polishing) as a roughening treatment. That is, an uneven surface is formed on the first main surface by chemical etching. In chemical etching, the object to be treated (support film in the present invention) is immersed in a polishing solution which is an acid solution or an alkaline solution for a predetermined time, and the surface of the object to be treated is roughened by the dissolving action of the polishing solution, and then the surface of the object to be treated is roughened. It is a process of forming a roughened object to be treated by washing with water and drying. The roughness of the surface of the object to be treated, that is, the degree of unevenness on the uneven surface can be adjusted by the immersion time in the polishing liquid or the like. Examples of the polishing liquid include an aqueous solution of potassium hydroxide, an aqueous solution of sodium hydroxide, an aqueous solution of potassium permanganate and the like. The uneven surface of the first main surface is an uneven surface formed by chemical etching or an uneven surface formed by another treatment (for example, a rough surface obtained by forming a film of a resin composition containing a filler into a film). Whether it is a surface, a blasted rough surface, etc.) can be determined by observing the processed state of the unevenness with a microscope or the like.

From the above, in the photosensitive dry film of the present invention, as a support film, a matted film (kneaded matte film) obtained by adding a filler to a resin composition for forming a film and kneading it into a matte film. No other roughened film such as a coated matte film or a film whose surface is blasted by sandblasting is not used.

Since the uneven surface formed by chemical etching has a smooth rough surface structure, diffused reflection of light can be prevented during exposure, and no processing residue is generated during the roughening treatment. Further, in the chemical etching, the light transmittance, solvent resistance and wettability of the support film are superior to those of the above-mentioned other roughening treatments, so that the photo-curing film (cured film) does not impair the insulation reliability. ) Can be formed. Further, as will be described later, the photosensitive resin layer is provided on the first main surface of the support film having the uneven surface formed by chemical etching, so that the shape of the uneven surface of the first main surface can be changed. Accordingly, a photocurable film (cured film) having an uneven surface portion is formed. Therefore, in the photosensitive dry film of the present invention, it is possible to obtain a photocurable film (cured film) having a matte appearance and excellent resolution and insulation reliability.

The arithmetic average surface roughness Sa of the uneven surface of the first main surface is not particularly limited, but the lower limit thereof is preferably 0.10 μm from the viewpoint of surely obtaining the matte appearance of the photocured film. 20 μm is more preferable, and 0.30 μm is particularly preferable from the viewpoint of improving the matte appearance, resolution and insulation reliability in a well-balanced manner. On the other hand, the upper limit of the arithmetic average surface roughness Sa of the uneven surface of the first main surface is preferably 1.00 μm from the viewpoint of more reliably imparting resolution and insulation reliability to the photocured film. 0.90 μm is more preferable, 0.80 μm is further preferable, and 0.70 μm is particularly preferable from the viewpoint of improving the matte appearance, resolution and insulation reliability in a well-balanced manner.

On the other hand, the second main surface of the support film has not been roughened. Therefore, the second main surface is not chemically etched and has no uneven surface. From the above, the second main surface of the support film has a smooth surface morphology with an arithmetic mean surface roughness Sa lower than that of the first main surface, and is a smooth surface.

When the support film is immersed in an etching solution that is an acid solution or an alkaline solution for a predetermined time, the second main surface is covered with a masking film, and the first main surface is exposed to the polishing solution without being covered with the masking film. The first main surface can be roughened while the second main surface is not chemically etched.

The thickness of the support film can be appropriately selected depending on the conditions of use of the photosensitive dry film and the like, and examples thereof include 10 μm and more and 100 μm or less. The material of the support film is not particularly limited as long as it can form the uneven surface as described above and can transmit light at the time of exposure, and is, for example, polyester such as polyethylene terephthalate and polyethylene naphthalate. Films; polyimide films; polyamideimide films; thermoplastic resins such as polypropylene films and polystyrene films can be mentioned.

[Photosensitive resin layer]
The photosensitive resin layer is a coating film formed by coating a photosensitive resin composition on the first main surface of the support film. The photosensitive resin layer may be formed in a state of being in direct contact with the first main surface, and an intermediate layer such as a surface treatment layer is interposed between the photosensitive resin layer and the first main surface. May be. The photosensitive resin composition includes, for example, (A) a photosensitive resin, (B) an epoxy compound, (C) an aliphatic urea compound, (D) a reactive diluent, and (E) a photopolymerization initiator. And contains.

(A) Photosensitive Resin Examples of the photosensitive resin include a carboxyl group-containing photosensitive resin having a free carboxyl group in the side chain. The chemical structure of the carboxyl group-containing photosensitive resin is not particularly limited, and examples thereof include a carboxyl group-containing resin having one or more, preferably two or more photosensitive unsaturated double bonds in one molecule. As the carboxyl group-containing photosensitive resin, for example, acrylic acid or methacrylic acid (hereinafter referred to as "(meth) acrylic acid") is added to at least a part of the epoxy group of the polyfunctional epoxy resin having two or more epoxy groups in one molecule. A radically polymerizable unsaturated monocarboxylic oxide such as epoxy (meth) acrylate is reacted with a radically polymerizable unsaturated monocarboxylic acid such as), and a polybase is added to the hydroxyl group generated in the resin. Examples thereof include a polybasic acid-modified radically polymerizable unsaturated monocarboxylic oxide epoxy resin such as a polybasic acid-modified epoxy (meth) acrylate obtained by reacting an acid and / or a polybasic acid anhydride.

The resin type of the polyfunctional epoxy resin is not particularly limited as long as it is a bifunctional or higher functional epoxy resin. The epoxy equivalent of the polyfunctional epoxy resin is not particularly limited, but for example, the upper limit thereof is preferably 3000 g / eq, more preferably 2000 g / eq, and particularly preferably 1500 g / eq. On the other hand, the lower limit of the epoxy equivalent of the polyfunctional epoxy resin is, for example, preferably 100 g / eq, and particularly preferably 200 g / eq.

Examples of the polyfunctional epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, biphenyl aralkyl type epoxy resin, phenyl aralkyl type epoxy resin, biphenyl type epoxy resin, naphthalene type epoxy resin, and dicyclopentadiene type epoxy resin. ε-caprolactone-modified epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol modified novolak type epoxy resin, cyclic aliphatic epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, heterocyclic epoxy resin, etc. Can be mentioned. These polyfunctional epoxy resins may be used alone or in combination of two or more.

The radically polymerizable unsaturated monocarboxylic acid is not particularly limited, and examples thereof include (meth) acrylic acid, crotonic acid, cinnamic acid, tiglic acid, and angelic acid. Of these, (meth) acrylic acid is preferable from the viewpoint of easy availability. These radically polymerizable unsaturated monocarboxylic acids may be used alone or in combination of two or more. When the radically polymerizable unsaturated monocarboxylic acid reacts with the epoxy group of the polyfunctional epoxy resin, a photosensitive unsaturated double bond is introduced into the side chain of the resin, and the resin is imparted with photosensitivity.

The reaction method between the polyfunctional epoxy resin and the radically polymerizable unsaturated monocarboxylic acid is not particularly limited, and for example, the polyfunctional epoxy resin and the radically polymerizable unsaturated monocarboxylic acid are used as an appropriate non-reactive diluent ( For example, heating in an organic solvent) can be mentioned.

A polybasic acid and / or a polybasic acid anhydride reacts with a hydroxyl group generated by opening a ring of an epoxy group by a reaction between a polyfunctional epoxy resin and a radically polymerizable unsaturated monocarboxylic acid, resulting in non-photosensitivity. A free carboxyl group is further introduced into the resin into which the saturated double bond has been introduced. Alkaline developability is imparted to the resin by introducing a free carboxyl group into the resin into which the photosensitive unsaturated double bond is introduced. The polybasic acid and the polybasic acid anhydride are not particularly limited, and either saturated or unsaturated can be used. Examples of the polybasic acid include succinic acid, maleic acid, adipic acid, citric acid, phthalic acid, and phthalic acid derivatives (for example, tetrahydrophthalic acid, 3-methyltetrahydrophthalic acid, 4-methyltetrahydrophthalic acid, 3-ethyl). Tetrahydrophthalic acid, 4-ethyltetrahydrophthalic acid, hexahydrophthalic acid, 3-methylhexahydrophthalic acid, 4-methylhexahydrophthalic acid, 3-ethylhexahydrophthalic acid, 4-ethylhexahydrophthalic acid, methyltetrahydro Phthalic acid, methylhexahydrophthalic acid, endomethylenetetrahydrophthalic acid, methylendomethylenetetrahydrophthalic acid), trimellitic acid, pyromellitic acid, diglycolic acid and the like can be mentioned. Further, examples of the polybasic acid anhydride include the above-mentioned polybasic acid anhydride. These compounds may be used alone or in combination of two or more.

The reaction method between the radically polymerizable unsaturated monocarboxylic oxide epoxy resin and the polybasic acid and / or the polybasic acid anhydride is not particularly limited, and for example, the radically polymerizable unsaturated monocarboxylic oxide epoxy resin and the polybasic acid and / Or heating the polybasic acid anhydride in a suitable non-reactive diluent (eg, an organic solvent) can be mentioned.

The above-mentioned polybasic acid-modified radically polymerizable unsaturated monocarboxylic oxide epoxy resin can also be used as a photosensitive resin, but if necessary, one of the carboxyl groups of the above-mentioned polybasic acid-modified radically polymerizable unsaturated monocarboxylic oxide epoxy resin. Further, a compound having one or more radically polymerizable unsaturated groups and an epoxy group (for example, a glycidyl compound) is reacted with the moiety to further introduce a radically polymerizable unsaturated group into the side chain of the resin. , A carboxyl group-containing photosensitive resin having further improved photosensitivity may be used.

In the carboxyl group-containing photosensitive resin having further improved photosensitivity, a radically polymerizable unsaturated group is modified by a polybasic acid modification radically polymerizable unsaturated monocarboxylic oxide epoxy resin skeleton by adding a glycidyl compound to a free carboxyl group. Since it is bonded to the side chain of the radical polymer, the photopolymerization reactivity, that is, the photocurability is further improved, and more excellent photosensitivity is exhibited. Examples of the glycidyl compound include glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, pentaerythritol triacrylate monoglycidyl ether, pentaerythritol trimethacrylate monoglycidyl ether and the like. The above-mentioned compound having one or more radically polymerizable unsaturated groups and an epoxy group may be used alone or in combination of two or more.

The acid value of the carboxyl group-containing photosensitive resin is not particularly limited, but the lower limit thereof is preferably 30 mgKOH / g and particularly preferably 40 mgKOH / g from the viewpoint of obtaining reliable alkali developability. On the other hand, the upper limit of the acid value of the carboxyl group-containing photosensitive resin is preferably 200 mgKOH / g from the viewpoint of surely preventing the dissolution of the exposed portion (photocured portion) by the alkaline developer, and the moisture resistance of the photocured product. 150 mgKOH / g is particularly preferable from the viewpoint of preventing the above.

The mass average molecular weight (Mw) of the photosensitive resin is not particularly limited, but the lower limit thereof is preferably 6000, more preferably 7000, and particularly preferably 8000 from the viewpoint of the toughness of the photocured product and the dryness to the touch. .. On the other hand, the upper limit of the mass average molecular weight (Mw) of the photosensitive resin is preferably 200,000, more preferably 100,000, and particularly preferably 50,000, from the viewpoint of surely preventing a decrease in alkali developability.

As the photosensitive resin, the photosensitive resin may be synthesized by the above reaction using each of the above starting materials, or a commercially available photosensitive resin may be used. Examples of the photosensitive resin on the market include "SP-4621" (Showa Denko KK), "KAYARAD ZAR-2000", "KAYARAD ZFR-1122", "KAYARAD FLX-2089", and "KAYARAD ZCR-1569H". "(Nippon Kayaku Co., Ltd.)," Cyclomer P (ACA) Z-250 "(Dycel Co., Ltd.) and other carboxyl group-containing photosensitive resins can be mentioned. Further, these photosensitive resins may be used alone or in combination of two or more.

(B) Epoxy compound The epoxy compound is for increasing the crosslink density of the photo-cured product to obtain a photo-cured product having sufficient strength. Examples of the epoxy compound include epoxy resins. The chemical structure of the epoxy resin is not particularly limited, and for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, biphenyl aralkyl type epoxy resin, phenyl aralkyl type epoxy resin, biphenyl type epoxy resin, naphthalene type epoxy resin, and di. Cyclopentadiene type epoxy resin, ε-caprolactone modified epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol modified novolak type epoxy resin, cyclic aliphatic epoxy resin (lipid ring type epoxy resin), glycidyl ester type epoxy resin , Glycidylamine type epoxy resin, heterocyclic epoxy resin, triazine type epoxy resin, hydroquinone type epoxy resin, tetrakisphenol ethane type epoxy resin and the like can be mentioned. These epoxy compounds may be used alone or in combination of two or more. Among these epoxy compounds, bisphenol A type epoxy resin, biphenyl type epoxy resin, and fat can contribute to more reliably obtaining a photocurable film having a matte appearance with excellent insulation reliability and resolution. Cyclic epoxy resin is preferred.

The content of the epoxy compound is not particularly limited, but is preferably 10 parts by mass or more and 100 parts by mass or less, and particularly preferably 20 parts by mass or more and 70 parts by mass or less with respect to 100 parts by mass of the photosensitive resin.

(C) Aliphatic urea compound The aliphatic urea compound can contribute to the formation of a matte appearance of the photo-cured product while contributing to the improvement of the resolution and insulation reliability of the photo-cured product. Aliphatic urea compounds are aliphatic urea compounds that do not have an aromatic ring in their chemical structure.

The melting point of the aliphatic urea compound is not particularly limited, but is preferably 100 ° C. or higher and 250 ° C. or lower, and 120 ° C. or higher and 230 ° C. or lower, from the viewpoint of surely contributing to the matte appearance, insulation reliability and resolution. , 140 ° C. or higher and 210 ° C. or lower are particularly preferable.

（式中、Ｒ^１、Ｒ^２、Ｒ^３、Ｒ^４、Ｒ^５、Ｒ^６、Ｒ^７は、それぞれ、独立して、炭素数１～２０個の飽和脂肪族炭化水素基、または少なくとも１つのエチレン性不飽和基を有する炭素数２～２０個の不飽和脂肪族炭化水素基を表す。）で表される化合物を挙げることができる。 Examples of the aliphatic urea compound include an aliphatic urea compound having a cyclic aliphatic structure. The aliphatic urea compound having a cyclic aliphatic structure includes the following general formula (1).

(In the formula, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ , respectively, are independently saturated aliphatic hydrocarbon groups having 1 to 20 carbon atoms, or at least one. Examples thereof include compounds represented by (representing an unsaturated aliphatic hydrocarbon group having 2 to 20 carbon atoms) having an ethylenically unsaturated group.

Of these, ^R1 , ^R2 , R3 ^{, R4} , ^R5 , ^R6 , and ^R7 are, respectively, from the viewpoint of reducing the gloss value of the photocured compound and surely contributing to the formation of a matte appearance. Independently, the aliphatic urea compound of the general formula (1), which is a saturated aliphatic hydrocarbon group having 1 to ⁵ carbon atoms, is more preferable, and ^R1 , ^R2 , R3 ^{, R4} , R5, The aliphatic urea compound of the general formula (1) in which R ⁶ and R ⁷ are independently saturated aliphatic hydrocarbon groups having 1 to 3 carbon atoms is more preferable, and R ¹ , R ² , and R are more preferable. Aliphatic urea compounds of the general formula (1) in which ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ are all methyl groups are particularly preferable. The aliphatic urea compound of the general formula (1) in which R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , and R ⁷ are all methyl groups is N'-[3-[[[. (Dimethylamino) carbonyl] amino] methyl] -3,5,5-trimethylcyclohexyl] -N, N-dimethylurea. The melting point of N'-[3-[[[(dimethylamino) carbonyl] amino] methyl] -3,5,5-trimethylcyclohexyl] -N, N-dimethylurea is about 150 ° C.

The content of the aliphatic urea compound is not particularly limited, but the lower limit is preferably 1.0 part by mass with respect to 100 parts by mass of the photosensitive resin from the viewpoint of surely contributing to the formation of a matte appearance. 2.0 parts by mass is more preferable, and 3.0 parts by mass is particularly preferable. On the other hand, the upper limit of the content of the aliphatic urea compound is preferably 20 parts by mass, more preferably 15 parts by mass, and particularly preferably 10 parts by mass with respect to 100 parts by mass of the photosensitive resin from the viewpoint of insulation reliability. preferable.

(D) Reactive Diluent The reactive diluent is, for example, a photopolymerizable monomer and is a compound having at least one polymerizable double bond per molecule, preferably two or more polymerizable double bonds per molecule. The reactive diluent sufficiently photocures the photosensitive resin composition and contributes to acid resistance, heat resistance, alkali resistance and the like of the photocured product. Examples of the reactive diluent include (meth) acrylate monomers, and specifically, monofunctional (meth) acrylate monomers, bifunctional (meth) acrylate monomers, and trifunctional or higher (meth). Examples thereof include acrylate monomers. Specific examples include 2-hydroxyethyl (meth) acrylate, phenoxyethyl (meth) acrylate, diethylene glucol mono (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylic rate, and caprolactone-modified (meth). Monofunctional (meth) acrylates such as acrylates, 1,4-butanediol di (meth) acrylates, 1,6-hexanediol di (meth) acrylates, neopentyl glycol di (meth) acrylates, diethylene glycol di (meth) acrylates. , Neopentyl glycol adipate di (meth) acrylate, hydroxypivalate neopentyl glycol di (meth) acrylate, dicyclopentanyl di (meth) acrylate, ethylene oxide-modified di (meth) acrylate, allylated cyclohexyl di (meth) Bifunctional (meth) acrylates such as acrylates and isocyanurate di (meth) acrylates, trimethylol propanetri (meth) acrylates, ditrimethylol propanetetra (meth) acrylates, dipentaerythritol tri (meth) acrylates, pentaerythritoltri (pentaerythritoltri (meth) acrylates. Three or more functionalities such as meth) acrylate, propylene oxide-modified trimethylol propantri (meth) acrylate, tris (acryloxyethyl) isocyanurate, propionic acid-modified dipentaerythritol penta (meth) acrylate, and dipentaerythritol hexa (meth) acrylate. (Meta) acrylate, urethane (meth) acrylate and the like can be mentioned. By blending urethane (meth) acrylate, flexibility can be imparted to the photo-cured product. These may be used alone or in combination of two or more.

The content of the reactive diluent is not particularly limited, but is preferably 5.0 parts by mass or more and 50 parts by mass or less, and particularly preferably 10 parts by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the photosensitive resin.

(E) Photopolymerization initiator The photopolymerization initiator is not particularly limited, and is, for example, 1,2-octanedione, 1- [4- (phenylthio) -2- (O-benzoyloxime)], etanone 1- [. 9-Ethyl-6- (2-methylbenzoyl) -9H-carbazole-3-yl] -1- (0-acetyloxime), 2- (acetyloxyiminomethyl) thioxanthene-9-one, 1,8- Octanedione, 1,8-bis [9-ethyl-6-nitro-9H-carbazole-3-yl]-, 1,8-bis (O-acetyloxime), 1,8-octanedione, 1,8- Bis [9- (2-ethylhexyl) -6-nitro-9H-carbazole-3-yl]-, 1,8-bis (O-acetyloxime), (Z)-(9-ethyl-6-nitro-9H) -Carbazole-3-yl) (4-((1-methoxypropan-2-yl) oxy) -2-methylphenyl) Oxime ester-based photopolymerization initiator such as methanone O-acetyloxime, 2-benzyl-2- Dimethylamino-1-morpholinofenone) -butanone-1,2- (dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone, 2 -Methyl-1- [4- (Methylthio) phenyl] -2-morpholino-propanone-1, 1-benzyl-1- (dimethylamino) propyl-4-morpholinophenyl-ketone and other α-aminoalkylphenone-based photopolymerization Initiators include.

Further, as the photopolymerization initiator, other photopolymerization initiators other than the oxime ester-based photopolymerization initiator and the α-aminoalkylphenone-based photopolymerization initiator may be used. Examples of other photopolymerization initiators include benzoin-based photopolymerization initiators such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether and benzoin isobutyl ether; acetophenone, dimethylaminoacetophenone, 2 , 2-Dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone and other acetophenone-based photopolymerization initiators; benzophenone, p-phenylbenzophenone, 4,4'-diethylaminobenzophenone, dichlorobenzophenone and other benzophenones. Anthraquinone-based photopolymerization initiators such as 2-methylanthraquinone, 2-ethylanthraquinone, 2-tertiary butyl anthraquinone, 2-aminoanthraquinone; 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorthioxanthone. , 2,4-Dimethylthioxanthone, 2,4-diethylthioxanthone and other thioxanthone-based photopolymerization initiators; ethyl-4- (dimethylamino) benzoate, 2-n-butoxyethyl-4- (dimethylamino) benzoate, methyl- Bentoate-based photopolymerization initiators such as 4- (dimethylamino) benzoate, isoamyl-4- (dimethylamino) benzoate, 2- (dimethylamino) ethyl benzoate, 2-ethylhexyl-4- (dimethylamino) benzoate, etc. Can be mentioned. These photopolymerization initiators may be used alone or in combination of two or more. Among the above photopolymerization initiators, an oxime ester-based photopolymerization initiator and an α-aminoalkylphenone-based photopolymerization initiator are preferable from the viewpoint of excellent photosensitivity.

The content of the photopolymerization initiator is not particularly limited, but is preferably 1.0 part by mass or more and 10 parts by mass or less, and 2.0 parts by mass or more and 8.0 parts by mass or less with respect to 100 parts by mass of the photosensitive resin. Especially preferable.

In addition to the above-mentioned components (A) to (E), the photosensitive resin composition may further contain other components, such as extender pigments, flame retardants, curing accelerators, additives, and colorants, if necessary. , Non-reactive diluent and the like can be appropriately blended.

Examples of the extender pigment include aluminum hydroxide, aluminum oxide, barium sulfate and the like. Examples of the curing accelerator include mercaptobenzoxalal and its derivatives, dicyandiamide (DICY) and its derivatives, melamine and its derivatives, boron trifluoride-amine complex, organic acid hydrazide, diaminomaleonitrile (DAMN) and Examples thereof include guanamine and its derivatives, amineimide (AI) and polyamine. Examples of the additive include defoaming agents such as silicone-based, hydrocarbon-based and acrylic-based, dispersants such as (meth) acrylic-based polymers, thixotropic agents, antioxidants, fillers and the like.

The colorant is not particularly limited to pigments, pigments and the like, and white colorant, blue colorant, green colorant, yellow colorant, purple colorant, black colorant, orange colorant, red colorant and the like, etc. Any colorant can be used, depending on the desired color. Examples of the colorant include inorganic colorants such as titanium dioxide (rutyl-type titanium oxide and anatase-type titanium oxide) which are white colorants, acetylene black and carbon black which are black colorants, and green colorants. Examples thereof include phthalocyanine-based colorants such as phthalocyanine green and phthalocyanine blue and lionol blue, which are blue colorants, and diketopyrrolopyrrole-based organic colorants such as chromophthalo orange, which is an orange colorant.

The flame retardant is for imparting flame retardancy to the photocurable product of the photosensitive resin layer. Examples of the flame retardant include phosphorus-based flame retardants. Examples of the phosphorus-based flame retardant include tris (chloroethyl) phosphate, tris (2,3-dichloropropyl) phosphate, tris (2-chloropropyl) phosphate, tris (2,3-bromopropyl) phosphate, and tris (bromo). Halogen-containing phosphoric acid such as chloropropyl) phosphate, 2,3-dibromopropyl-2,3-chloropropyl phosphate, tris (tribromophenyl) phosphate, tris (dibromophenyl) phosphate, tris (tribromoneopentyl) phosphate. Esters; Non-halogen aliphatic phosphate esters such as trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, tributoxyethyl phosphate; triphenyl phosphate, cresyl diphenyl phosphate, dicresyl phenyl phosphate, tricresyl phosphate, trixylate. Nylphosphate, xylenyldiphenyl phosphate, tris (isopropylphenyl) phosphate, isopropylphenyldiphenyl phosphate, diisopropylphenylphenyl phosphate, tris (trimethylphenyl) phosphate, tris (t-butylphenyl) phosphate, hydroxyphenyldiphenyl phosphate, octyldiphenyl phosphate. Non-halogen aromatic phosphate esters such as: Aluminum Trisdiethylphosphine, Aluminum Trismethylethylphosphine, Aluminum Trisdiphenylphosphine, Zinc bisdiphenylphosphine, Zinc bismethylethylphosphine, Zinc bisdiphenylphosphine, Bisdiethyl Metallic salts of phosphinic acid such as titanyl phosphine, titanium tetrakisdiethylphosphine, titanyl bismethylethylphosphine, titanium tetrakismethylethylphosphine, titanyl bisdiphenylphosphine, titanium tetrakisdiphenylphosphine, 9,10-dihydro-9. Examples thereof include phosphine oxide compounds such as -oxa-10-phosphaphenanthrene-10-oxide, diphenylvinylphosphine oxide, triphenylphosphine oxide, trialkylphosphine oxide, and tris (hydroxyalkyl) phosphine oxide. Of these, organic phosphate-based flame retardants are preferable. These may be used alone or in combination of two or more.

The non-reactive diluent is a component for adjusting the viscosity and dryness of the photosensitive resin layer, the viscosity of the photosensitive resin composition, and the coatability. Examples of the non-reactive diluent include organic solvents. Examples of the organic solvent include ketones such as methyl ethyl ketone, aromatic hydrocarbons such as benzene, toluene and xylene, alcohols such as methanol, ethanol, n-propanol, isopropanol and cyclohexanol, and fats such as cyclohexane and methylcyclohexane. Cyclic hydrocarbons, petroleum ethers, petroleum solvents such as petroleum naphtha, cellosolves such as cellosolve and butyl cellosolve, carbitols such as carbitol and butyl carbitol, ethyl acetate, butyl acetate, cellosolve acetate, butyl cellosolve acetate, carvi Examples thereof include esters such as tall acetate, butyl carbitol acetate, ethylene glycol acetate, and ethyl diglycol acetate. These may be used alone or in combination of two or more.

The method for producing the above-mentioned photosensitive resin composition is not limited to a specific method. For example, after blending each of the above components in a predetermined ratio, at room temperature (for example, 10 ° C to 30 ° C), a three-roll or ball mill is used. , Sand mill, bead mill, kneader or the like, or a super mixer, a planetary mixer, a trimix or the like for stirring and mixing means, can be kneaded or mixed and produced. Further, before the kneading or mixing, pre-kneading or pre-mixing may be carried out, if necessary.

The thickness of the photosensitive resin layer can be appropriately selected depending on the conditions of use of the photosensitive dry film and the like, and examples thereof include 10 μm and more and 100 μm or less.

<Manufacturing method of photosensitive dry film>
Next, an example of a method for producing the photosensitive dry film of the present invention will be described. The photosensitive dry film of the present invention is a support film, a photosensitive resin layer coated on the support film, and a cover film that protects the photosensitive resin layer (for example, a resin film such as a polyethylene film or a polypropylene film). It has a laminated structure with and. First, the above-mentioned photosensitive resin composition is applied onto the first main surface of the support film by a known method such as a roller coating method or a bar coater method to apply a photosensitive resin composition having a predetermined film thickness. Form a film. By drying the coating film of the formed photosensitive resin composition, a photosensitive resin layer is formed on the first main surface of the support film. Then, by laminating a cover film on the formed photosensitive resin layer, a photosensitive dry film having a photosensitive resin layer can be produced.

<How to use photosensitive dry film>
Next, an example of how to use the photosensitive dry film of the present invention will be described. Here, a method of forming a solder resist film, which is an insulating protective film, by using the photosensitive dry film of the present invention on a printed wiring board having a circuit pattern formed by etching a copper foil will be described as an example. That is, a method of manufacturing a printed wiring board having an insulating protective film by using the photosensitive dry film of the present invention for forming a solder resist film will be described.

The method for manufacturing a printed wiring board having an insulating protective film includes a step of adhering a photosensitive resin layer of a photosensitive dry film to the printed wiring board and irradiating ultraviolet rays from the support film of the photosensitive dry film to make the photosensitive dry film. A step of photo-curing the resin layer, a step of peeling the support film from the photosensitive dry film, and a step of developing the photo-cured photosensitive resin layer to form a photo-curing film having a predetermined pattern, and a predetermined step. The present invention comprises a step of thermally curing the photo-cured film having a pattern to form a cured film having an uneven surface portion.

Specifically, first, with respect to the photosensitive dry film produced as described above, the photosensitive resin layer (solder resist layer) and the printed wiring board are bonded to each other while the cover film is peeled off, so that the photosensitive dry film is photosensitive on the printed wiring board. A resin layer (solder resist layer) is formed. The laminating conditions for laminating the photosensitive resin layer (solder resist layer) of the photosensitive dry film and the printed wiring board are, for example, 10 to 60 under vacuum at a temperature of 40 to 60 ° C. and a pressure of 0.3 to 0.7 MPa. The condition of pressurizing for a second can be mentioned. At this stage, the support film is still laminated on the photosensitive resin layer (solder resist layer). Then, if necessary, in order to volatilize the non-reactive diluent in the photosensitive resin layer, pre-drying is performed by heating at a temperature of about 100 to 120 ° C. for about 1 to 10 minutes, and the photosensitive resin layer is non-reactive. The reactive diluent is volatilized to make the surface of the photosensitive resin layer (solder resist layer) tack-free. After that, a negative film having a pattern having a translucent pattern other than the land of the circuit pattern is placed on the support film, and ultraviolet rays (for example, a wavelength range of 300 to 400 nm) are irradiated from above the negative film to make the negative film photosensitive. The resin layer (solder resist layer) is photocured. Then, the support film is peeled off and the non-exposed region corresponding to the land is removed with a dilute alkaline aqueous solution to develop a photosensitive resin layer (solder resist layer) to form a photocurable film having a predetermined pattern. As a developing method, a spray method, a shower method or the like is used, and examples of the dilute alkaline aqueous solution used include a 0.5 to 5% by mass sodium carbonate aqueous solution. After alkaline development, the photosensitive resin layer (solder resist layer) is heat-cured for 20 to 80 minutes in a hot air circulation type dryer or the like at 130 to 170 ° C. to form an uneven surface on the printed wiring board. By having it, it is possible to form a solder resist film having a matte appearance.

In the photosensitive dry film of the present invention, since the photosensitive resin layer is provided on the first main surface of the support film having the uneven surface formed by chemical etching, the uneven surface of the first main surface is provided. A cured film having an uneven surface portion is formed according to the morphology. From the above, the cured film has a concavo-convex surface portion to which the morphology of the concavo-convex surface of the first main surface is transferred. Therefore, for example, when the arithmetic average surface roughness Sa of the uneven surface of the first main surface is in the range of 0.10 μm or more and 1.00 μm or less, the arithmetic average surface roughness Sa of the uneven surface portion of the cured film is set. When the range is 0.10 μm or more and 1.00 μm or less and the arithmetic average surface roughness Sa of the uneven surface of the first main surface is 0.50 μm, the arithmetic average surface roughness Sa of the uneven surface portion of the cured film Is 0.50 μm.

In the photosensitive dry film of the present invention, as described above, it is possible to obtain a photocured product having a matte appearance, that is, a matted appearance. For example, after laminating the photosensitive resin layer of the photosensitive dry film of the present invention on a substrate, it is dried at 110 ° C. for 5 minutes, irradiated with ultraviolet rays of 150 mJ / cm ² , and at 150 ° C. for 60 minutes. The gloss value obtained by measuring the 60-degree mirror reflectance of the surface of the photo-cured product after thermosetting with a gloss meter is preferably 50% or less. By reducing the gloss value to 50% or less, it is possible to obtain a photocured product having a matte appearance and having a hiding power. The lower the gloss value, the more preferable, but for example, 40% or less is more preferable, and 30% or less is particularly preferable.

Next, examples of the present invention will be described, but the present invention is not limited to these examples as long as the gist of the present invention is not exceeded.

Examples 1 to 7, Comparative Examples 1 to 6
Each component shown in Tables 1 and 2 below was blended in the blending ratio shown in Tables 1 and 2 below, and the mixture was mixed and dispersed at room temperature (about 25 ° C.) using three rolls, and compared with Examples 1 to 7. Photosensitive resin compositions to be used as the photosensitive resin layers of the photosensitive dry films of Examples 1 to 6 were prepared. Unless otherwise specified, the blending amount of each component shown in Tables 1 and 2 below is shown in parts by mass. In addition, the blank part of the blending amount in the following Tables 1 and 2 means no blending.

The details of each component in Tables 1 and 2 below are as follows.
(A) Photosensitive resin-KAYARAD ZCR-1569H: Solid content (resin content) 65% by mass, Nippon Kayaku Co., Ltd. KAYARAD ZCR-1569H is a carboxyl group-containing photosensitive resin and is an epoxy resin (biphenyl aralkyl type epoxy resin). ) Is reacted with acrylic acid to obtain epoxy acrylate, and the hydroxyl group of the epoxy acrylate is reacted with polybasic acid to prepare a polybasic acid-modified epoxy acrylate resin. Is.

(B) Epoxy compound-EPICLON 850-S: Liquid epoxy compound, DIC-YX-4000: Crystalline epoxy compound with melting point less than 130 ° C, melting point about 105 ° C, Mitsubishi Chemical Corporation, Serokiside 2021P: Daicel Co., Ltd.

(C) Aliphatic urea compound-U-Cat3513N: Melting point about 150 ° C., N'-[3-[[[(dimethylamino) carbonyl] amino] methyl] -3,5,5-trimethylcyclohexyl] -N, N-Dimethylurea, Sun Appro Co., Ltd.

(D) Reactive Diluent-EBECRYL8405: Daicel Cytec Co., Ltd. (E) Photopolymerization Initiator-OXE02: Etanon 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazole-3-yl] -1- (0-Acetyloxime), BASF, Inc. Irgacure 369: 1-benzyl-1- (dimethylamino) propyl-4-morpholinophenyl-ketone, BASF, Inc.

Constituent pigment, Heidilite H42M: Showa Denko Co., Ltd. Flame retardant, Exolit OP-935: Clariant Japan Co., Ltd. Hardening accelerator, Melamine: Nissan Chemical Industry Co., Ltd., DICY-7: Mitsubishi Chemical Co., Ltd. Additive, AC-303: Dispersion Agent, Kyoeisha Chemical Co., Ltd. Colorant / Denka Black: Denka Denko Co., Ltd. Non-reactive diluent / EDGAC: Sanyo Kasei Co., Ltd.

Photosensitive dry film manufacturing process Support film for photosensitive dry film-Support film of Examples 1 to 7: Mitsubishi Resin Co., Ltd., 25 μm thick polyethylene terephthalate (PET) film “R310” (arithmetic average surface roughness Sa: 0) After a masking film made of polypropylene film is attached to one side (second main surface) of (.03 μm), it is immersed in a 38 mass% potassium hydroxide aqueous solution (95 ° C.) (chemical etching) and washed with water. The masking film was peeled off and dried to obtain a chemical etching film having a predetermined arithmetic average surface roughness Sa on the other side (first main surface). This chemical etching film was used as the support film of Examples 1-7. The arithmetic mean surface roughness Sa of the first main surface of the chemical etching film was adjusted by the immersion time in the potassium hydroxide aqueous solution.

-Supporting film of Comparative Example 1: Unitika Ltd., Emblet CM-25, 25 μm thick coated matte film (arithmetic mean surface roughness Sa: 0.6 μm)
-Supporting film of Comparative Example 2: Unitika Ltd., Emblet SM-25, Sandmatt film with a thickness of 25 μm in which the film surface was sandblasted (arithmetic mean surface roughness Sa: 0.6 μm)
-Supporting film of Comparative Example 3: Unitika Ltd., Emblet PTH-25, 25 μm-thick kneaded matte film (double-sided kneaded matte film, arithmetic mean surface of the first main surface and the second main surface. Roughness Sa: 0.3 μm)
-Supporting film of Comparative Example 4: Mitsubishi Resin Co., Ltd., R310, 25 μm thick polyethylene terephthalate (PET) film (without matte treatment, arithmetic average surface roughness Sa: 0.03 μm)
Support film of Comparative Example 5: Double-sided chemicals in the same manner as in Examples except that the first main surface and the second main surface were both chemically etched without attaching a masking film to the second main surface of R310. The etched chemical etching film was used as a support film (arithmetic average surface roughness Sa was 0.4 μm for both the first main surface and the second main surface).
-Supporting film of Comparative Example 6: Unitika Co., Ltd., 25 μm-thick kneaded single-sided matte film (Arithmetic mean surface roughness Sa of the first main surface: 0.3 μm, Arithmetic mean surface roughness of the second main surface) Sa: 0.03 μm).

Coating of the photosensitive resin composition on the support film: A photosensitive resin composition is applied to one side (first main surface) of the support film so that the thickness of the photosensitive resin layer after pre-drying is 30 μm. It was painted by the bar coater method.
Pre-drying: 110 ° C., 5 minutes A photosensitive dry film was prepared by the above steps.

Test sample preparation process Evaluation board: Double-layer copper-clad laminate (pitch between conductors 25 μm, conductor thickness 12.5 μm)
Surface treatment of evaluation substrate: Surface treatment using 5% by mass sulfuric acid Laminating conditions of photosensitive dry film on evaluation substrate: 50 ° C., pressurization 0.5 MPa, vacuum 30s / pressurization 30s
Exposure treatment (light curing treatment): Exposure development: Support film by irradiating the photosensitive resin layer with ultraviolet rays (wavelength 300 to 400 nm) at 150 mJ / cm ² with a projection exposure device (light source is high-pressure mercury lamp, USHIO Co., Ltd.). After peeling off, develop with 1 mass% sodium carbonate aqueous solution. Development conditions are temperature 30 ° C, spray pressure 0.2 MPa, development time 60 seconds thermosetting (post-cure): 150 ° C, 60 minutes.

Evaluation items (1) Gloss value (matte appearance)
A 60-degree mirror reflectance was measured on the surface of the photosensitive resin layer using a gloss meter VG-2000 (Nippon Denshoku Industries Co., Ltd.). It was evaluated that a matte appearance was obtained when the gloss value was 50% or less.

(2) Arithmetic mean surface roughness Sa
Arithmetic mean surface roughness Sa of the uneven surface of the support film and the uneven surface of the cured film is based on ISO 25178 using a surface roughness meter (Keyence Co., Ltd., model "Shape Analysis Laser Microscope VK-X1000"). Was measured.

(3) Photovia resolution The photosensitive resin layer was exposed through a predetermined photomask (via opening diameter φ200 μm), and then the photovia diameter opened by development was measured with a metallurgical microscope.

(4) Insulation reliability (insulation reliability in the thickness direction (Z-axis direction) of the cured coating film)
For the test sample prepared in the above test sample preparation step, the upper surface of the cured film in which silver was vapor-deposited on the cured film was connected to the anode, and copper, which is the conductor of the evaluation substrate, was connected to the cathode. Next, 50 V was applied in a constant temperature and humidity chamber at 60 ° C. and a humidity of 95%, and the resistance value was continuously measured using an ion migration tester (IMV, “MIG-8600B / 128”). The measurement start time is when 50V is applied, the time until the resistance value drops to less than 1.0E + ⁶ (1.0 × 106) Ω is measured, and this is the dielectric breakdown time. The insulation breakdown in the Z-axis direction) was evaluated.
⊚: Dielectric breakdown time 1500 hours or more.
◯: Dielectric breakdown time 1000 hours or more and less than 1500 hours.
X: Dielectric breakdown time is less than 1000 hours.

The evaluation results are shown in Tables 1 and 2 below.

As shown in Table 1 above, the photosensitive dry films of Examples 1 to 7 having an uneven surface formed by chemical etching on one side of the support film have excellent insulation reliability and resolution, and have a matte appearance. A cured film could be formed. In particular, in Examples 1 to 5 and 7 in which the arithmetic average surface roughness Sa of the uneven surface of the support film is 0.3 to 0.7 μm, the insulation reliability is excellent and the arithmetic average surface roughness of the uneven surface of the support film is excellent. In Examples 1 to 4 and 7 in which Sa was 0.3 to 0.6 μm, the resolution and insulation reliability were excellent. Further, in Examples 2 to 6 and 7 in which the arithmetic average surface roughness Sa of the uneven surface of the support film is 0.4 to 0.8 μm, the gloss value is 30% or less, and a more excellent matte appearance can be obtained. Was done. Further, from Example 3 and Example 7, no matter which of the bisphenol A type epoxy resin, the biphenyl type epoxy resin, and the alicyclic epoxy resin is blended as the epoxy compound, the insulation reliability and the resolution are excellent, and the matte It was possible to form a cured film having an appearance. Therefore, it was found that the chemical structure of the epoxy compound blended in the photosensitive resin composition is not particularly limited.

On the other hand, as shown in Table 2 above, in Comparative Example 1 using a coated matte film as a support film and Comparative Example 2 using a sand matte film, although a matte appearance could be obtained, insulation reliability was obtained. I couldn't. Further, in Comparative Example 3 in which a kneaded matte film was used as the support film, a matte appearance could be obtained, but resolution could not be obtained. Further, even in Comparative Example 6 in which a single-sided kneaded matte film was used as the support film, a matte appearance could be obtained, but resolution could not be obtained. Further, in Comparative Example 5 in which both sides of the support film had uneven surfaces formed by chemical etching, a matte appearance could be obtained, but resolution was not obtained. Further, in Comparative Example 4 using a support film having an arithmetic average surface roughness Sa of 0.03 μm, a matte appearance could not be obtained.

The photosensitive dry film of the present invention can obtain a photocured film having a matte appearance with excellent insulation reliability and resolution by having an uneven surface formed by chemical etching on one side of the support film. Therefore, for example, it has high utility value in the field of an insulating protective film (solder resist film) provided on a printed wiring board.

Claims (8)

A photosensitive dry film comprising a support film having a first main surface and a second main surface facing the first main surface, and a photosensitive resin layer provided on the first main surface. And
The first main surface has an uneven surface formed by chemical etching and has an uneven surface.
A photosensitive dry film having an arithmetic average surface roughness Sa of the uneven surface of the first main surface of 0.30 μm or more and 0.80 μm or less . The photosensitive dry film according to claim 1, wherein the arithmetic average surface roughness Sa of the uneven surface of the first main surface is 0.40 μm or more and 0.80 μm or less. The photosensitive dry film according to claim 1 or 2, wherein the second main surface does not have an uneven surface formed by chemical etching. The photosensitive dry film according to any one of claims 1 to 3, wherein the photosensitive resin layer is formed of a photosensitive resin composition, and the photosensitive resin composition contains an aliphatic urea compound. The photosensitive resin composition comprises (A) a photosensitive resin, (B) an epoxy compound, (C) an aliphatic urea compound, (D) a reactive diluent, and (E) a photopolymerization initiator. The photosensitive dry film according to claim 4, which comprises. The photosensitive dry film according to claim 5, wherein the epoxy compound (B) contains at least one selected from the group consisting of a bisphenol A type epoxy resin, a biphenyl type epoxy resin and an alicyclic epoxy resin. The photosensitive dry film according to any one of claims 1 to 6, which is used for forming a solder resist film. A step of bonding the photosensitive resin layer of the photosensitive dry film according to any one of claims 1 to 7 to a printed wiring board.
A step of photocuring the photosensitive resin layer by irradiating ultraviolet rays from the support film of the photosensitive dry film.
A step of peeling the support film from the photosensitive dry film and developing the photocured photosensitive resin layer to form a photocurable film having a predetermined pattern.
It comprises a step of thermally curing the photocurable film having a predetermined pattern to form a cured film having an uneven surface portion.
A method for manufacturing a printed wiring board in which the arithmetic average surface roughness Sa of the uneven surface portion of the cured film is 0.30 μm or more and 0.80 μm or less.