KR101623278B1 - Photosensitive resin composition, dry film, cured product and printed wiring board - Google Patents

Abstract

The present invention provides a technique capable of suppressing occurrence of development residue in a hole portion such as a through hole in a solder resist composition containing titanium oxide.
The present invention provides a photosensitive resin composition comprising (A) a carboxyl group-containing resin, (B) an epoxy thermosetting component, (C) an inorganic filler, and (D) a photopolymerization initiator, wherein (A) (B) the equivalent of epoxy groups contained in the epoxy-based thermosetting component is 1.0 or less, (C) the inorganic filler contains titanium oxide, a dry film using the same, and a cured product thereof.

Description

TECHNICAL FIELD [0001] The present invention relates to a photosensitive resin composition, a dry film, a cured product, and a printed wiring board,

The present invention relates to a photosensitive resin composition (hereinafter simply referred to as a "composition"), a dry film, a cured product and a printed wiring board, and more particularly to an alkali developing photosensitive resin composition, a dry film, And a printed wiring board.

Generally, a printed wiring board is formed by removing an unnecessary portion of a copper foil bonded to a laminate by etching to form a circuit wiring, and the electronic component is disposed at a predetermined place by soldering. In such a printed wiring board, a protective film for preventing adhesion of solder to a necessary portion and for preventing the conductor of the circuit from being exposed and being corroded by oxidation or moisture, A solder resist is formed in the region. Since the solder resist also functions as a permanent protective film of the circuit board, the solder resist is required to have various performances such as adhesiveness, electrical insulation, solder heat resistance, solvent resistance, and chemical resistance.

As a method of forming a solder resist of a desired pattern on a substrate, a forming method using a photolithography technique is used. For example, a photosensitive solder resist containing an alkali developing type photosensitive resin composition is exposed through a pattern mask and then subjected to alkali development to obtain a pattern using a difference in solubility in an alkali developing solution generated in the exposed portion and non- .

For example, Patent Document 1 discloses a solder resist composition containing a white pigment and capable of forming a solder resist layer having high light reflectivity while suppressing the amount of light necessary for exposure. In order to provide a solder resist composition containing a photosensitive resin, a white pigment , A photopolymerization initiator which is activated by light having a wavelength of 400 nm or more, and a fluorescent dye.

Japanese Patent Laid-Open Publication No. 2011-227343 (claims)

Incidentally, the solder resist composition may contain a large amount of titanium oxide in order to color the composition to white. However, since the composition containing a large amount of titanium oxide has low fluidity, it is difficult to remove it if it enters into the hole portion of the through hole or the like, and there is a problem that the development residue remains.

An object of the present invention is to provide a technique capable of suppressing occurrence of development residue in a hole portion such as a through hole in a solder resist composition containing titanium oxide.

As a result of intensive studies, the inventors of the present invention have found that, by setting the equivalent weight of the epoxy group contained in the composition to 1.0 or less based on 1 equivalent of the carboxyl groups contained in the composition, even when titanium oxide is contained in a large amount, Can be suppressed, and the present invention has been accomplished.

That is, the photosensitive resin composition of the present invention is a photosensitive resin composition containing (A) a carboxyl group-containing resin, (B) an epoxy thermosetting component, (C) an inorganic filler, and (D)

(B) the equivalent of the epoxy group contained in the epoxy-based thermosetting component is 1.0 or less, and the inorganic filler (C) contains titanium oxide with respect to 1 equivalent of the carboxyl group contained in the carboxyl group-containing resin (A) .

In the composition of the present invention, it is preferable that the epoxy thermosetting component (B) contains at least one or more of an epoxy resin which is liquid at 20 占 폚 and a solid epoxy resin which is solid at 40 占 폚. In the composition of the present invention, the ratio of the equivalence of the carboxyl group contained in the carboxyl group-containing resin (A) to the equivalence of the epoxy group contained in the epoxy-based thermosetting component (B) is preferably 0.8 or less. In the composition of the present invention, it is preferable that the carboxyl-containing resin (A) is derived from styrene or a styrene derivative.

The dry film of the present invention is characterized by having a resin layer obtained by applying and drying the photosensitive resin composition of the present invention on a carrier film.

The cured product of the present invention is obtained by curing the resin layer of the photosensitive resin composition of the present invention or the dry film of the present invention by light irradiation.

Further, the printed wiring board of the present invention is characterized by having the cured product of the present invention.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to realize a technique capable of suppressing occurrence of development residue in a hole portion such as a through hole in a solder resist composition containing titanium oxide.

1 is a schematic side view showing two test tubes used for liquid phase determination of an epoxy resin.

Hereinafter, embodiments of the present invention will be described in detail.

First, each component of the photosensitive resin composition of the present invention will be described. Further, in the present specification, (meth) acrylate is a generic term for acrylate, methacrylate, and mixtures thereof, and the same applies to other similar expressions.

[(A) Resin containing a carboxyl group]

The photosensitive resin composition of the present invention contains (A) a carboxyl group-containing resin. As the carboxyl group-containing resin (A), a resin containing a known carboxyl group can be used. The presence of a carboxyl group makes the composition alkaline developable. In addition, from the viewpoint of making the composition of the present invention photo-curable and having an excellent developing property, it is preferable to have an ethylenically unsaturated bond in the molecule other than the carboxyl group, but only a carboxyl group-containing water not having an ethylenically unsaturated double bond may be used. (A) the carboxyl group-containing resin may or may not have an aromatic ring. (A) when the carboxyl group-containing resin has an aromatic ring, an effect of suppressing deterioration due to heat or light is obtained.

Specific examples of the carboxyl group-containing resin that can be used in the composition of the present invention include the following compounds (any of oligomers and polymers) listed below.

(1) A carboxyl group-containing resin obtained by copolymerizing an unsaturated carboxylic acid such as (meth) acrylic acid with an unsaturated group-containing compound such as styrene,? -Methylstyrene, lower alkyl (meth) acrylate or isobutylene. When the carboxyl group-containing resin has an aromatic ring, at least one of the unsaturated carboxylic acid and the unsaturated group-containing compound may have an aromatic ring.

(2) Diisocyanates such as aliphatic diisocyanates, branched aliphatic diisocyanates, alicyclic diisocyanates and aromatic diisocyanates, carboxyl-containing dialcohol compounds such as dimethylolpropionic acid and dimethylolbutanoic acid, and polycarbonate-based polyols, polyether Containing carboxyl groups in a diol compound such as polyol, polyol, polyester polyol, polyolefin polyol, acrylic polyol, bisphenol A alkylene oxide adduct diol, phenolic hydroxyl group and alcoholic hydroxyl group. Urethane resin. When the carboxyl group-containing urethane resin has an aromatic ring, at least one of the diisocyanate, the carboxyl group-containing dialcohol compound and the diol compound may have an aromatic ring.

(3) A process for producing a polyisocyanate compound, which comprises reacting a diisocyanate compound such as an aliphatic diisocyanate, a branched aliphatic diisocyanate, an alicyclic diisocyanate or an aromatic diisocyanate with a polycarbonate-based polyol, a polyether- , A terminal carboxyl group-containing urethane resin obtained by reacting an acid anhydride at the terminal of a urethane resin by a heavy-chain reaction of a diol compound such as a bisphenol A-based alkylene oxide adduct diol, a phenolic hydroxyl group and a compound having an alcoholic hydroxyl group . When the carboxyl group-containing urethane resin has an aromatic ring, at least one of the diisocyanate compound, the diol compound and the acid anhydride may have an aromatic ring.

(4) a bifunctional epoxy resin such as a bisphenol A type epoxy resin, a hydrogenated bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a bisphenol S type epoxy resin, a beacilene type epoxy resin and a biphenol type epoxy resin (Meth) acrylate or a partial acid anhydride thereof, a carboxyl group-containing dialcohol compound and a diol compound. When the photosensitive carboxyl group-containing urethane resin has an aromatic ring, at least one of the diisocyanate, the (meth) acrylate of the bifunctional epoxy resin or the partial acid anhydride modification thereof, the carboxyl group-containing dialcohol compound and the diol compound has an aromatic ring do.

(5) During the synthesis of the resin of the above (2) or (4), a compound having one hydroxyl group and at least one (meth) acryloyl group in the molecule such as hydroxyalkyl (meth) (Meth) acrylated carboxyl group-containing urethane resin. When the photosensitive carboxyl group-containing urethane resin has an aromatic ring, a compound having one hydroxyl group and at least one (meth) acryloyl group in the molecule may have an aromatic ring.

(6) In the synthesis of the resin of the above (2) or (4), it is preferable to use a mixture of isophorone diisocyanate and pentaerythritol triacrylate, such as equimolar reactants, having one isocyanate group and at least one (meth) acryloyl group in the molecule (Meth) acrylated carboxyl group-containing urethane resin by adding a compound. When the photosensitive carboxyl group-containing urethane resin has an aromatic ring, a compound having one isocyanate group and at least one (meth) acryloyl group in the molecule may have an aromatic ring.

(7) A photosensitive carboxyl group-containing resin obtained by reacting a polyfunctional epoxy resin with (meth) acrylic acid and adding a dibasic acid anhydride such as phthalic anhydride, tetrahydrophthalic anhydride, or hexahydrophthalic anhydride to a hydroxyl group present in the side chain. When the photosensitive carboxyl-containing resin has an aromatic ring, at least one of the polyfunctional epoxy resin and the dibasic acid anhydride may contain an aromatic ring.

(8) A photosensitive carboxyl group-containing resin obtained by reacting a (meth) acrylic acid with a polyfunctional epoxy resin obtained by epoxidizing a hydroxyl group of a bifunctional epoxy resin with epichlorohydrin and adding a dibasic acid anhydride to the resulting hydroxyl group. When the photosensitive carboxyl group-containing resin has an aromatic ring, at least one of the bifunctional epoxy resin and the dibasic acid anhydride may have an aromatic ring.

(9) A carboxyl group-containing polyester resin in which a dibasic acid anhydride is added to a primary hydroxyl group generated by reacting a polycarboxylic acid with a polyfunctional oxetane resin. When the photosensitive carboxyl group-containing polyester resin has an aromatic ring, at least one of the polyfunctional oxetane resin, dicarboxylic acid and dibasic acid anhydride may contain an aromatic ring.

(10) A reaction product obtained by reacting a reaction product obtained by reacting a compound having a plurality of phenolic hydroxyl groups in a molecule with an alkylene oxide such as ethylene oxide or propylene oxide, with a monocarboxylic acid containing an unsaturated group is reacted with a polybasic acid anhydride To obtain a carboxyl group-containing photosensitive resin.

(11) A reaction obtained by reacting a compound having a plurality of phenolic hydroxyl groups in a molecule with a cyclic carbonate compound such as ethylene carbonate or propylene carbonate to react with a monocarboxylic acid containing an unsaturated group A photosensitive resin containing a carboxyl group obtained by reacting a product with a polybasic acid anhydride.

(12) A process for producing an epoxy compound having a plurality of epoxy groups in a molecule, a compound having at least one alcoholic hydroxyl group and one phenolic hydroxyl group in one molecule such as p-hydroxyphenethyl alcohol, and a compound having an unsaturated (meth) Containing monocarboxylic acid and reacting the alcoholic hydroxyl group of the obtained reaction product with a polybasic acid anhydride such as maleic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, or adipic acid anhydride A carboxyl group-containing photosensitive resin. When the photosensitive carboxyl group-containing polyester resin has an aromatic ring, at least one of the epoxy compound, the compound having at least one alcoholic hydroxyl group and one phenolic hydroxyl group in one molecule, the unsaturated group-containing monocarboxylic acid and the polybasic acid anhydride, You just need a ring.

(13) The resin composition according to any one of the above items (1) to (12), further comprising one or more epoxy groups in the molecule such as glycidyl (meth) acrylate and? -Methyl glycidyl (meth) Meth) acryloyl group is added to the photosensitive resin composition. When the photosensitive carboxyl group-containing urethane resin has an aromatic ring, a compound having one epoxy group and at least one (meth) acryloyl group in the molecule may have an aromatic ring.

Since the carboxyl group-containing resin has a large number of carboxyl groups in the side chain of the backbone polymer, development with a dilute aqueous alkali solution becomes possible.

Among the above-mentioned resins, it is preferable to use a resin containing a carboxyl group (A) derived from styrene or a styrene derivative because a composition having excellent solder heat resistance can be obtained.

The acid value of the carboxyl group-containing resin is preferably in the range of 20 to 200 mgKOH / g, more preferably 40 to 180 mgKOH / g. If it is in the range of 20 to 200 mgKOH / g, the adhesion of the coating film is obtained, the alkali development is facilitated, the dissolution of the exposed portion by the developer is suppressed, the line is not thinned more than necessary, Which is preferable.

The weight average molecular weight of the carboxyl group-containing resin used in the present invention varies depending on the resin skeleton, but is preferably in the range of 2,000 to 150,000. Within this range, the tack-free performance is good, the wettability of the coating film after exposure is good, and the film is hardly reduced at the time of development. When the weight average molecular weight is in the above range, the resolution is improved, the developing property is good, and the storage stability is improved. More preferably from 5,000 to 100,000. The weight average molecular weight can be measured by gel permeation chromatography.

[(B) Epoxy-based thermosetting component]

The photosensitive resin composition of the present invention contains (B) an epoxy thermosetting component in order to impart heat resistance. As the epoxy-based thermosetting component (B), those used as a thermosetting component in the thermosetting resin composition, specifically, a compound having a plurality of epoxy groups in the molecule, that is, a known polyfunctional epoxy compound can all be used.

Examples of the polyfunctional epoxy compound include bisphenol A type epoxy resins such as jER828 manufactured by Mitsubishi Chemical Corporation; Brominated epoxy resin; Novolak type epoxy resins; Bisphenol F type epoxy resin; Hydrogenated bisphenol A type epoxy resin; Glycidylamine type epoxy resins; Hidanto dolphin epoxy resin; Alicyclic epoxy resins; Trihydroxyphenylmethane type epoxy resin; Bixyl silane type or biphenol type epoxy resins such as YX-4000 manufactured by Mitsubishi Chemical Corporation or a mixture thereof; Bisphenol S type epoxy resin; Bisphenol A novolak type epoxy resin; Cresol novolak type epoxy resins such as RN-695 manufactured by DIC Corporation; Tetraphenylol ethane type epoxy resin; A heterocyclic epoxy resin such as TEPIC manufactured by Nissan Chemical Industries, Ltd.; Diglycidyl phthalate resin; Tetraglycidylsilanoy ethane resin; A naphthalene group-containing epoxy resin; An epoxy resin having a dicyclopentadiene skeleton; Flexible tough epoxy resin; Glycidyl methacrylate copolymer epoxy resin; And copolymerized epoxy resins of cyclohexylmaleimide and glycidyl methacrylate, but are not limited thereto. These epoxy resins may be used alone or in combination of two or more. Among these, a bifunctional epoxy resin is preferable from the viewpoint of flexibility. In particular, biphenyl novolak type epoxy resins, biquilene type epoxy resins or mixtures thereof are preferable from the viewpoint of flame retardancy.

In the present invention, the blending amount of the epoxy thermosetting component (B) is preferably such that the equivalent amount of the epoxy group contained in the epoxy-based thermosetting component (B) is 1.0 or less based on 1 equivalent of the carboxyl group contained in the (A) . Preferably, the ratio of the equivalence of the carboxyl group contained in the carboxyl group-containing resin (A) to the equivalent of the epoxy group contained in the epoxy-based thermosetting component (B) is in the range of 0.1 to 0.8, do. Here, in the present invention, the equivalents of the carboxyl group and the epoxy group mean chemical equivalents of a carboxyl group and an epoxy group as a reactor, respectively. That is, in the present invention, the number of epoxy groups in the epoxy-based thermosetting component (B) contained in the composition (dry film) is made smaller than the number of carboxyl groups in the carboxyl-containing resin (A).

Normally, the blending amount of the epoxy thermosetting component (B) is within a range that can prevent the carboxyl group from remaining in the cured coating. In the present invention, the blending amount of the epoxy-based thermosetting component (B) Within the above range, by decreasing the number of epoxy groups to be reacted with respect to the number of carboxyl groups, a large amount of carboxyl groups contributing to developability can be retained even after thermosetting. This makes it possible to increase the solubility in a developer even in a cured coating containing titanium oxide, and to suppress the occurrence of a development residue even in a hole portion such as a through hole. In the present invention, the hole portion of the through hole or the like is not limited to the through hole but includes another hole portion such as a via hole. The smaller the diameter of the hole, the more likely the residue is clogged. However, according to the present invention, it is possible to carry out the development without generating a residue even if the hole has a small inner diameter of 300 mm or less, specifically 200 mm or more and 300 mm or less, Do.

In the present invention, it is preferable that (B) the epoxy-based thermosetting component contains at least one or more of epoxy resin which is liquid at 20 占 폚 and solid epoxy resin which is solid at 40 占 폚. Here, in the present invention, the solid phase is a concept including powder. When the epoxy resin (B) is an epoxy thermosetting component and contains a liquid epoxy resin at 20 占 폚, the viscosity tends to flow at a low rate, so that development residue in the through hole is less likely to occur. Further, when the epoxy-based thermosetting component (B) contains a solid epoxy resin as a powder at 40 占 폚, it is difficult to clog the through-hole, and thus development residue is hardly generated. Also, in the case of (B) a solid epoxy resin which is solid at 40 占 폚 as the epoxy-based thermosetting component (B), as in the case of powder, it is difficult to clog in the through hole, and development residue is hardly generated. Contrary to this, if the epoxy resin is semi-solid at the temperature at the time of development, it is in a state intermediate between the solid state and the liquid state and has a high viscosity, so that the development residue tends to enter the through hole easily, . In recent years, this phenomenon tends to occur particularly, because the size of the through hole is made smaller with the miniaturization of the substrate.

Here, the determination method of " liquid phase " in the present invention will be described.

The determination of the liquid phase shall be made in accordance with the Attachment 2 (Method for Confirmation of Liquid Phase) of the Ordinance on the Testing and Characterization of Dangerous Goods (1989 Self-Government Ordinance No. 1).

(1) Device

Constant temperature bath:

A stirrer, a heater, a thermometer, a thermostat (capable of temperature control at a temperature of 占 .0 占 폚), and a depth of 150 mm or more is used.

In the determination of the epoxy resin used in the later-described examples, all combinations of tap water with a tap water thermometer (type BU300) made by Yamato Kagaku Co., Ltd. and a thermo-mate type thermometer (type BF500) (Type BU300), turn on the thermometer (type BF500) attached to it, set it to the set temperature (20 ℃ or 40 ℃), set the water temperature to the set temperature ± 0.1 ℃ Type BF500), but any device that can perform the same adjustment can be used.

examiner:

As shown in Fig. 1, test tubes were made of plain cylindrical transparent glass with an inner diameter of 30 mm and a height of 120 mm, and mark lines 31 and 32 were respectively applied to the points of 55 mm and 85 mm from the base, And a rubber stopper 33b with a hole for inserting and supporting a thermometer in the center are provided at the entrance of the test tube 30a with the same size and in the same size as the test tube 30a for liquid phase determination sealed with the rubber stopper 33a, And a temperature measuring test tube 30b in which a thermometer 34 is inserted into the rubber stopper 33b is used. Hereinafter, a table line having a height of 55 mm from the site is referred to as " A line " and a table line having a height of 85 mm from the site is referred to as a " B line ".

As the thermometer 34, a temperature range of 0 to 50 占 폚 is to be measured, while a thermometer 34 (SOP-58 scale range: 20 to 50 占 폚) specified in JIS B7410 (1982) Anything that can be done.

(2) Procedure for conducting tests

A sample left to stand for 24 hours or more at atmospheric pressure at a temperature of 20 ± 5 ° C was placed in a test tube 30a for liquid determination and a test tube for temperature measurement 30b shown in Figure 1 (b) Put them up to line A, respectively. The two test tubes 30a and 30b are placed upright in the low-temperature and constant-temperature water bath so that the line B is below the water. The lower end of the thermometer should be 30 mm below the A line.

After the sample temperature reaches the set temperature ± 0.1 ℃, it is maintained for 10 minutes. After 10 minutes, the test tube 30a for judging the liquid phase was taken out from the low-temperature constant-temperature water bath, immediately dropped on the horizontal test bench horizontally, and the time when the tip of the liquid surface in the test tube moved from line A to line B was measured with a stopwatch Record. The sample is judged to be a liquid phase when the measured time is within 90 seconds at the set temperature, and a solid phase when it exceeds 90 seconds.

Examples of the epoxy resin which is liquid at 20 占 폚 include bisphenol A type epoxy resins such as jER828 manufactured by Mitsubishi Chemical Corporation, bisphenol F type epoxy resins, phenol novolak type epoxy resins, tert-butyl-catechol type epoxy resins, Aminophenol type epoxy resins, alicyclic epoxy resins, and the like. It goes without saying that the epoxy resin which is liquid at 20 占 폚 may be in a liquid state at less than 20 占 폚. As the epoxy resin, an aromatic epoxy resin is preferable from the viewpoints of favorable physical properties of the cured product. In this specification, the aromatic epoxy resin means an epoxy resin having an aromatic ring skeleton in its molecule. Therefore, as the epoxy resin which is liquid at 20 占 폚, an aromatic epoxy resin which is liquid at 20 占 폚 is more preferable. These epoxy resins may be used alone or in combination of two or more.

Examples of the solid epoxy resin which is solid at 40 占 폚 include naphthalene type epoxy resins such as tetrafunctional naphthalene type epoxy resin and naphthalene skeleton containing polyfunctional solid epoxy resin; Epoxides of phenols and condensates of aromatic aldehydes having a phenolic hydroxyl group (trisphenol type epoxy resin); A dicyclopentadiene aralkyl type epoxy resin such as a dicyclopentadiene skeleton-containing polyfunctional solid epoxy resin; Biphenylaralkyl type epoxy resins such as biphenyl skeleton-containing polyfunctional solid epoxy resin; Novolak type epoxy resins; Bixyl silane type or biphenol type epoxy resins such as YX-4000 manufactured by Mitsubishi Chemical Corporation or a mixture thereof; Cresol novolak type epoxy resins such as RN-695 manufactured by DIC Corporation; And heterocyclic epoxy resins such as TEPIC manufactured by Nissan Chemical Industries, Ltd., and the like. These epoxy resins may be used alone or in combination of two or more. In particular, in order to impart low thermal expansion properties, it is preferable to use an epoxy resin containing a naphthalene skeleton.

Examples of the semi-solid epoxy resin (C) which is solid at 20 占 폚 and liquid at 40 占 폚 include bisphenol A type epoxy resin; Naphthalene type epoxy resin; Phenol novolak type epoxy resins, and the like. These epoxy resins may be used alone or in combination of two or more.

[(C) Inorganic filler]

The alkali-developable photosensitive resin composition of the present invention contains (C) an inorganic filler. Examples of the inorganic filler (C) include calcium carbonate, magnesium carbonate, fly ash, dehydrated sludge, natural silica, synthetic silica, kaolin, clay, calcium oxide, magnesium oxide, titanium oxide, zinc oxide, barium sulfate, alumina, talc, Magnesium silicate, magnesium phosphate, sepiolite, zonolite, boron nitride, aluminum borate, silica balloon, glass flake, calcium carbonate, calcium carbonate, calcium carbonate, A glass powder, a glass powder, a glass balloon, an amorphous silica, crystalline silica, fused silica, spherical silica, seasonal slag, copper, iron, iron oxide, carbon black, , Diatomaceous earth, antimony trioxide, magnesium oxysulfate, aluminum hydrate, hydrated gypsum, alum and the like. These inorganic fillers may be used singly or in combination of two or more kinds.

Among the above, in the present invention, (C) titanium oxide is contained as an inorganic filler. (C) By containing titanium oxide as an inorganic filler, the cured product of the composition can be made white, and high reflectance can be obtained. On the other hand, as described above, the composition containing titanium oxide has a problem in that development residue is likely to occur in through-holes and the like because the fluidity is lowered. In the present invention, however, the composition containing (A) By setting the equivalent ratio of the epoxy group contained in the carboxyl group and the epoxy-based thermosetting component (B) within the above-mentioned predetermined range, it becomes possible to obtain a cured film having a high reflectance without any problem of development residue.

The titanium oxide may be titanium oxide having either of a rutile type, an anatase type, and a rhamstellite type. Ram seudel light type titanium oxide, is obtained by a lithium desorption treatment by a chemical oxidation carried out on persons seudel light type Li _{0 .5} TiO _2. Rutile-type titanium oxide is preferable because it does not cause discoloration due to light irradiation.

The amount of the inorganic filler (C) containing such titanium oxide as an essential component is preferably 5 to 20 parts by weight, based on the solid content in the photosensitive resin composition (when the photosensitive resin composition contains an organic solvent, the component excluding the organic solvent) To 80% by mass, and more preferably from 10% to 70% by mass.

[(D) Photopolymerization initiator]

The alkali-developable photosensitive resin composition of the present invention contains (D) a photopolymerization initiator. As the photopolymerization initiator (D), any known photopolymerization initiator may be used as the photopolymerization initiator or photo radical generator.

(D) a photopolymerization initiator such as bis- (2,6-dichlorobenzoyl) phenylphosphine oxide, bis- (2,6-dichlorobenzoyl) -2,5-dimethylphenylphosphine oxide, bis- (2,6-dichlorobenzoyl) -1-naphthylphosphine oxide, bis- (2,6-dimethoxybenzoyl) phenylphosphine oxide, Bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, bis- (2,6-dimethoxybenzoyl) -2,5-dimethylphenylphosphine oxide, bis- , 4,6-trimethylbenzoyl) -phenylphosphine oxide (IRGACURE 819, manufactured by BASF Japan); 2,6-dimethoxybenzoyldiphenylphosphine oxide, 2,6-dichlorobenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylphosphinic acid methyl ester, 2-methylbenzoyldiphenylphosphine oxide, Monoacylphosphine oxides such as valylphenylphosphinic acid isopropyl ester and 2,4,6-trimethylbenzoyldiphenylphosphine oxide (DAROCUR TPO, manufactured by BASF Japan Co., Ltd.); 1-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy- 2-methyl-1-phenyl-propan-1-one, 2-hydroxy- Hydroxyacetophenones such as 1-one; Benzoin such as benzoin, benzyl, benzoin methyl ether, benzoin ethyl ether, benzoin n-propyl ether, benzoin isopropyl ether and benzoin n-butyl ether; Benzoin alkyl ethers; Benzophenones such as benzophenone, p-methylbenzophenone, Michler's ketone, methylbenzophenone, 4,4'-dichlorobenzophenone, and 4,4'-bisdiethylaminobenzophenone; Acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexyl phenyl ketone, N, N-dimethylaniline, N, N-diethylamino-1- (4- Acetophenones such as N-dimethylaminoacetophenone; Thioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-di Thioxanthones such as isopropylthioxanthone; Anthraquinones such as anthraquinone, chloroanthraquinone, 2-methyl anthraquinone, 2-ethyl anthraquinone, 2-tert-butyl anthraquinone, 1-chloro anthraquinone, 2-amylanthraquinone and 2-aminoanthraquinone; Ketal such as acetophenone dimethyl ketal and benzyl dimethyl ketal; Benzoic acid esters such as ethyl-4-dimethylaminobenzoate, 2- (dimethylamino) ethylbenzoate and p-dimethylbenzoic acid ethyl ester; (9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-2-yl) Oxime esters such as 3-yl] -, 1- (0-acetyl oxime); Bis (η ⁵ -2,4- cyclopentadiene-1-yl) -bis (2,6-difluoro -3- (1H- pyrrol-1-yl) phenyl) titanium, bis (cyclopentadienyl) Titanocenes such as bis [2,6-difluoro-3- (2- (1-pyrrol-1-yl) ethyl) phenyl] titanium; Phenyl disulfide 2-nitrofluorene, butyloline, anisoo ethyl ether, azobisisobutyronitrile, tetramethylthiuram disulfide, and the like. All the above photopolymerization initiators may be used alone or in combination of two or more.

The blending amount of the photopolymerization initiator (D) in terms of solid content is 0.1 to 50 parts by mass relative to 100 parts by mass of the (A) carboxyl group-containing resin. By blending the photopolymerization initiator (D) in this range, the photocurability on copper becomes satisfactory, the curability of the coating becomes good, the coating film properties such as chemical resistance are improved, and the deep curing property is also improved. More preferably, it is 5 to 40 parts by mass based on 100 parts by mass of the (A) carboxyl group-containing resin.

(diluent)

The photosensitive resin composition of the present invention may contain a diluent. The diluent used in the present invention is used for improving the workability by adjusting the viscosity of the composition and for increasing the cross-linking density or improving the adhesiveness. The diluent is preferably a reactive diluent such as a photocurable monomer, or an organic solvent Can be used.

Examples of the photocurable monomer include alkyl (meth) acrylates such as 2-ethylhexyl (meth) acrylate and cyclohexyl (meth) acrylate; Hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate; Mono or di (meth) acrylates of alkylene oxide derivatives such as ethylene glycol, propylene glycol, diethylene glycol and dipropylene glycol; Polyhydric alcohols such as hexanediol, trimethylol propane, pentaerythritol, ditrimethylol propane, dipentaerythritol, and trishydroxy ethylisocyanurate, or polyvalent (meth) acrylates of the ethylene oxide or propylene oxide adduct Ryu; (Meth) acrylates of ethylene oxide or propylene oxide adduct of phenols such as phenoxyethyl (meth) acrylate and polyethoxydi (meth) acrylate of bisphenol A; (Meth) acrylates of glycidyl ethers such as glycerin diglycidyl ether, trimethylol propane triglycidyl ether and triglycidyl isocyanurate; And melamine (meth) acrylate.

The blending ratio of the photocurable monomer is preferably 5 to 100 parts by mass, more preferably 5 to 70 parts by mass, based on 100 parts by mass of the carboxyl group-containing resin (A). In the range of the blending ratio, photo-curability is improved, pattern formation is facilitated, and the strength of the cured film can be improved.

Examples of the organic solvent include ketones such as methyl ethyl ketone and cyclohexanone; Aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; Methyl cellosolve, butyl cellosolve, carbitol, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether, tripropylene glycol monomethyl ether And the like; Esters such as ethyl acetate, butyl acetate, butyl lactate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, butyl carbitol acetate, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate and propylene carbonate; Aliphatic hydrocarbons such as octane and decane; And petroleum solvents such as petroleum ether, petroleum naphtha and solvent naphtha. These organic solvents may be used alone or in combination of two or more.

(Other optional components)

The composition of the present invention may contain known additives in the field of electronic materials. Examples of additives include thermosetting catalysts, thermal polymerization inhibitors, ultraviolet absorbers, silane coupling agents, plasticizers, flame retardants, antistatic agents, antioxidants, antibacterial and antifungal agents, antifoaming agents, leveling agents, fillers other than the above, thickeners, A thixotropic property-imparting agent, a colorant, a photoinitiator, and a sensitizer.

(Flame retardant)

The photosensitive resin composition of the present invention may contain a flame retardant such as a phosphorus-containing compound. In the photosensitive resin composition of the present invention, even when a solid flame retardant is contained, generation of development residue in the hole can be suppressed. As the flame retardant, publicly known ones such as metal hydroxides and phosphorus-containing compounds can be used. Examples of the metal hydroxide include aluminum hydroxide, calcium hydroxide, magnesium hydroxide and the like. Examples of phosphorus-containing compounds include phosphorus-containing compounds such as phosphoric acid esters, condensed phosphoric acid esters, cyclic phosphazene compounds, phosphorus-containing compounds having phenolic hydroxyl groups, oligomers or polymers, phosphazene oligomers, phosphinic acid metal salts, .

In the above formulas, R ⁷ , R ⁸ and R ⁹ each independently represent a substituent other than a halogen atom. In the formula, R ⁷ and R ⁸ are preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ⁹ is preferably a hydrogen atom, an alkyl group having 1 to 4 carbon atoms which may be substituted with a cyano group, -Dihydroxyphenyl group or a 3,5-di-t-butyl-4-hydroxyphenyl group.

As the phosphazene oligomer, a phenoxyphosphazene compound is effective, and a substituted or unsubstituted phenoxyphosphazene oligomer or a cyclic compound of a trimer, tetramer, and pentamer.

The blending amount of the flame retardant is preferably 5 to 50 parts by mass, more preferably 10 to 40 parts by mass, based on 100 parts by mass of the carboxyl group-containing resin (A) in terms of solid content.

The dry film of the present invention has a resin layer obtained by applying and drying the composition of the present invention on a carrier film (support). The dry film can be formed by diluting the composition of the present invention with the above organic solvent and adjusting the viscosity to an appropriate viscosity, and then coating the resulting film with a solvent such as a comma coater, blade coater, lip coater, rod coater, squeeze coater, reverse coater, transfer roll coater, Coater or the like is applied on the carrier film in a uniform thickness. Thereafter, the applied composition is dried at a temperature of usually 50 to 130 DEG C for 1 to 30 minutes to form a resin layer. The thickness of the coating film is not particularly limited, but is generally appropriately selected in the range of 10 to 150 占 퐉, preferably 20 to 60 占 퐉 in film thickness after drying.

As the carrier film, a plastic film is used, and it is preferable to use a plastic film such as a polyester film such as polyethylene terephthalate, a polyimide film, a polyamideimide film, a polypropylene film, and a polystyrene film. The thickness of the carrier film is not particularly limited, but is generally appropriately selected in the range of 10 to 150 mu m.

It is preferable to further laminate a peelable cover film on the surface of the film for the purpose of preventing the adhesion of dust to the surface of the film after the resin layer containing the composition of the present invention is formed on the carrier film. As the peelable cover film, for example, a polyethylene film, a polytetrafluoroethylene film, a polypropylene film, a surface-treated paper and the like can be used. The cover film may be one that is smaller than the adhesive force between the resin layer and the carrier film when the cover film is peeled off.

The composition of the present invention may be prepared by a method such as dip coating, flow coating, roll coating, bar coating, screen printing, A curtain coating method and the like. Thereafter, the organic solvent contained in the composition is volatilized and dried (dried) at a temperature of about 60 to 100 DEG C, whereby a tack free resin layer can be formed. Further, in the case of a dry film obtained by applying the above composition onto a carrier film and drying it and then winding it as a film, the composition layer of the present invention is bonded to a substrate so as to be in contact with the substrate by a laminator, A layer can be formed.

As the base material, there may be used a base material such as paper phenol, paper epoxy, glass cloth epoxy, glass polyimide, glass cloth / nonwoven epoxy, glass cloth / paper epoxy, synthetic fiber epoxy, fluorine / polyethylene / poly (FR-4 and the like), other polyimide films, PET films, glass substrates, glass substrates, and the like, which are made of materials such as copper clad laminate for high frequency circuit using phenylene ether, polyphenylene oxide, cyanate ester, A ceramic substrate, a wafer plate, and the like.

The volatile drying performed after application of the composition of the present invention can be carried out by a hot-air circulating drying furnace, a hot plate, a convection oven or the like (a hot air circulating type drying furnace equipped with a heat source of air heating by steam, And a method of spraying onto a support from a nozzle) can be used.

The composition of the present invention can form a cured coating film having excellent properties such as heat resistance, chemical resistance, hygroscopicity, adhesion, electrical properties and the like by heating at a temperature of, for example, about 140 to 180 캜.

Further, the exposed portion (light-irradiated portion) is cured by exposing (irradiating) the resin layer obtained by applying the composition of the present invention and volatilizing and drying the solvent. Concretely, the photoresist is selectively exposed to an active energy beam through a photomask having a pattern formed thereon by a contact or noncontact method, or directly pattern-exposed by a laser direct exposure machine, and the unexposed portion is exposed to a dilute alkali aqueous solution , 0.3 to 3 wt% aqueous sodium carbonate solution) to form a resist pattern.

As an exposure device used for irradiation with the active energy ray, any device that irradiates ultraviolet rays in a range of 350 to 450 nm with a high pressure mercury lamp, an ultra high pressure mercury lamp, a metal halide lamp, a mercury short arc lamp, Devices (e.g., laser direct imaging devices that draw images directly with a laser by CAD data from a computer) can also be used. As a laser light source of a direct shot, either a gas laser or a solid laser is used when laser light having a maximum wavelength in the range of 350 to 410 nm is used. The exposure dose for image formation varies depending on the film thickness and the like, but may be generally within the range of 20 to 800 mJ / cm 2, preferably 20 to 600 mJ / cm 2.

Examples of the developing method include a dipping method, a shower method, a spraying method and a brushing method. Examples of the developing solution include aqueous alkali solutions such as potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate, ammonia, Can be used.

The composition of the present invention is suitable for formation of a cured film such as a solder resist or an interlayer insulating layer of a printed wiring board or a flexible printed wiring board. Further, the composition of the present invention can be used as a light source such as a light emitting diode (LED) or an electroluminescence (EL) used as a light source in a backlight of a liquid crystal display such as a lighting device, a portable terminal, a personal computer, And is suitably used for a reflector reflecting reflected light.

Example

Hereinafter, the present invention will be described in more detail with reference to examples.

Each component was blended according to the formulation shown in the following table, premixed by a stirrer, dispersed by a three roll mill, and kneaded to prepare a composition. The amounts in the tables represent parts by mass.

≪ Synthesis Example 1 (Production of carboxyl group-containing resin) >

42 parts by mass of methacrylic acid, 43 parts by mass of methyl methacrylate, 35 parts by mass of styrene, 35 parts by mass of benzyl acrylate, and 100 parts by mass of carbitol acetate 100 were added to a four-necked flask equipped with a reflux condenser, a thermometer, , 0.5 part by mass of lauryl mercaptan and 4 parts by mass of azobisisobutyronitrile were added and heated at 75 DEG C for 5 hours under a nitrogen stream to proceed the polymerization reaction to obtain a copolymer solution (solid content concentration: 50% by mass) . Then, 0.05 parts by mass of hydroquinone, 23 parts by mass of glycidyl methacrylate and 2.0 parts by mass of dimethylbenzylamine were added, and an addition reaction was carried out at 80 ° C for 24 hours. Then, 35 parts by mass of carbitol acetate was added, (Solid content concentration: 50% by mass).

≪ Developability (Through hole developing property) >

A 1.0 mm thick copper-plated laminated board was drilled with a 300 mm drill hole, and through-hole plating was carried out by a conventional method to prepare a substrate having 100 through-holes with a measured value of about 260 占 퐉. The composition of each of the examples and the comparative example was printed on the substrate twice by screen printing, dried for 30 minutes by a hot-air circulation type drying furnace at 80 캜, and cooled to room temperature. The substrate was developed and washed with a 1 mass% sodium carbonate aqueous solution at 30 占 폚 under a spray pressure of 0.2 MPa for 90 seconds to obtain a post-development substrate. The inside of the through-hole of the obtained substrate was observed with the naked eye and the scope, and the developability in the through hole was evaluated. A case in which there is no development residue, A in the case where development residue is a little, A in the case where development residue is present but a through hole is penetrated, and X is a case where development residue does not penetrate through hole.

≪ Reflectivity &

The composition of each of the examples and the comparative examples was applied to a FR-4 copper-clad laminate having a size of 100 mm x 150 mm and a thickness of 1.6 mm by a screen printing method using 100 mesh polyester (made of biaser) A pattern was printed on the front surface (entire surface of the substrate) using a plate. These were dried at 80 DEG C for 30 minutes by a hot air circulation type drying furnace. Further, using an exposure machine HMW-680GW (manufactured by Oak Seisakusho Co., Ltd.) for a printed circuit board, ultraviolet light exposure was performed at an integrated light quantity of 900 mJ / cm2 so as to leave a quadrangular negative pattern of 30 mm on one side. Thereafter, using a 1% aqueous solution of sodium carbonate at 30 DEG C as a developer, these were developed for 60 seconds by a developing device for a printed wiring board, and then thermally cured at 150 DEG C for 60 minutes by a hot air circulation type drying furnace, A test piece was prepared.

The obtained test piece was evaluated by a color chromaticity meter CR-400 (manufactured by Konica Minolta Sensing Co., Ltd.). The value of Y value was 85 or more, and the case of 80 or more and less than 85 was evaluated as?

≪ Soldering heat resistance &

A test piece coated with a rosin-based flux was immersed once in 30 seconds in a solder bath set at 260 占 폚 in advance and the flux was washed with denatured alcohol and evaluated for peeling of the resist layer by naked eyes. A case where peeling was not observed was indicated by?, A case where a slight peeling occurred, and a case where a significant peeling occurred was evaluated as?.

The above evaluation results are shown in the following table.

* 1) The carboxyl group-containing resin (carboxyl equivalent = 960) derived from styrene obtained in Synthesis Example 1

2) Diluted to 44% by mass with DPM (dipropylene glycol monomethyl ether) (manufactured by Daicel Chemical Industries, Ltd.) (carboxyl group-containing resin, carboxyl group equivalent = 806)

* 3) Bisphenol A type epoxy resin, a product of Mitsubishi Chemical Corporation (liquid at 20 ° C, epoxy equivalent = 185)

* 4) Powder (solid phase), epoxy equivalent weight = 100 at 40 ° C, manufactured by Nissan Chemical Industries, Ltd.

* 5) A biphenyl-type epoxy resin (manufactured by Mitsubishi Chemical Corporation) (powder (solid phase) at 40 ° C, epoxy equivalent = 182)

6) Cresol novolac epoxy resin (solid phase at 40 ° C, epoxy equivalent = 210) (manufactured by DIC Corporation)

※ 7) Ishihara Sangyo Co., Ltd.

※ 8) Made by Showa Denko Co., Ltd.

※ 9) Phosphinic acid aluminum salt, made by Clariant Japan Co., Ltd.

* 10) Monoacyl phosphine oxide photopolymerization initiator, lucylline TPO (2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide), BASF Japan Co.,

* 11) Bisacylphosphine oxide photopolymerization initiator, Irgacure 819 (bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide), BASF Japan Co.,

* 12) Imidazole compound, manufactured by Shikoku Kasei Kogyo Co., Ltd.

* 13) Diethylene glycol monomethyl ether acetate

※ 14) Aromatic hydrocarbons (Solvesso 150)

* 15) Dipentaerythritol hexaacrylate, manufactured by Kyoeisha Chemical Co., Ltd.

* 16) The ratio of the equivalent (number) of carboxyl groups contained in the carboxyl-containing resin (A) to the equivalent amount (number) of epoxy groups contained in the epoxy-based thermosetting component (B) in the dry state (Number of epoxy groups / number of carboxyl groups).

From the results in the above table, it can be seen that, in the compositions of the respective Examples, even when titanium oxide is contained, no development residue is generated in the through hole, and the solder heat resistance is also good. Thus, according to the present invention, it was confirmed that a photosensitive resin composition having a high reflectance can be obtained while ensuring good through-hole developability.

Claims (7)

(A) a resin containing a carboxyl group, (B) an epoxy thermosetting component, (C) an inorganic filler and (D) a photopolymerization initiator,
Wherein the ratio of the equivalent of the epoxy group contained in the epoxy-based thermosetting component (B) to the equivalent of the carboxyl group contained in the carboxyl group-containing resin (A) is 1.0 or less and the carboxyl group- , And the inorganic filler (C) contains titanium oxide. The photosensitive resin composition according to claim 1, wherein the epoxy thermosetting component (B) comprises at least one or more selected from an epoxy resin which is liquid at 20 占 폚 and a solid epoxy resin which is solid at 40 占 폚. A dry film comprising a resin film obtained by applying and drying the photosensitive resin composition according to claim 1 or 2 on a carrier film. A photosensitive resin composition according to any one of claims 1 to 3, which is obtained by applying the photosensitive resin composition on a carrier film and drying the cured resin layer of the dry film having a resin layer obtained by light irradiation Cured goods. A printed wiring board having the cured product according to claim 4. delete delete

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