TW201530256A - Photosensitive resin composition, dry film, cured product and printed wiring board - Google Patents

Abstract

The present invention is to provide a technology to suppress generation of development residue in cavity portions of through holes in a solder photoresist composition containing titanium oxide. The present invention relates to a photosensitive resin composition containing (A) a resin containing carboxyl, (B) an epoxy-based thermosetting composition, (C) an inorganic filler, and (D) an photo-polymerization initiator. In relative to one equivalent of carboxyl contained in (A) resin containing carboxyl, the equivalent of epoxy contained in (B) epoxy-based thermosetting composition is less than 1.0, and (C) inorganic filler contains titanium oxide. The present invention further relates to a dry film and a cured product using the same.

Description

Photosensitive resin composition, dry film, cured product, and printed wiring board

The present invention relates to a photosensitive resin composition (hereinafter, simply referred to as "composition"), a dry film, a cured product, and a printed wiring board, and is a composition of an alkali-developable photosensitive resin which is improved by a photopolymerization initiator. Dry film, hardened material and printed wiring board.

In general, a printed wiring board is a circuit wiring in which an unnecessary portion of a copper foil bonded to a laminate is removed by etching, and the electronic component is placed in a designated place by soldering. In such a printed wiring board, a protective film which is etched by oxidation or moisture to prevent solder from adhering to a necessary portion while preventing exposure of a conductor of the circuit is formed in a region outside the splicing hole on the substrate on which the circuit pattern is formed. Solder photoresist. Solder photoresist also functions as a permanent protective film for a circuit board. Therefore, solder photoresist is required to have various properties such as adhesion, electrical insulation, solder heat resistance, solvent resistance, and chemical resistance.

As one of the methods of forming a solder resist of a desired pattern on a substrate, a formation method using photolithography can be used. For example, a photosensitive solder resist composed of an alkali developing type photosensitive resin composition is transmitted through After exposure by the pattern mask, the pattern can be formed by alkali development using the difference in solubility to the alkali developer produced by the exposed portion and the non-exposed portion.

For example, Patent Document 1 discloses a solder resist composition which provides a solder resist layer containing a white pigment and which can suppress the amount of light required for exposure and has high light reflectivity, and is provided with a photosensitive resin, a white pigment, and a wavelength. A photopolymerization initiator which activates light of 400 nm or more and a solder resist composition of a fluorescent dye.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] JP-A-2011-227343 (Application for Patent, etc.)

[Summary of the Invention]

However, in the solder resist composition, in order to color the composition to white, a large amount of titanium oxide is contained. However, since the composition containing a large amount of titanium oxide has a low fluidity, it is difficult to remove and leave a development residue when it enters a hole portion such as a through hole.

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

As a result of reviewing the results, the inventors of the present invention found that the equivalent of the epoxy group contained in the composition is 1.0 or less, even when a large amount of titanium oxide is contained, with respect to 1 equivalent of the carboxyl group contained in the composition. The present invention has been completed by suppressing generation of development residue in a through hole or the like.

In other words, the photosensitive resin composition of the present invention is photosensitive containing (A) a carboxyl group-containing resin, (B) an epoxy thermosetting component, (C) an inorganic filler, and (D) a photopolymerization initiator. The resin composition is characterized by having 1 equivalent of the carboxyl group contained in the (A) carboxyl group-containing resin, and the equivalent of the epoxy group contained in the (B) epoxy group-based thermosetting component is 1.0 or less. (C) The inorganic filler contains titanium oxide.

In the composition of the present invention, the (B) epoxy group-based thermosetting component is preferably at least one selected from the group consisting of an epoxy resin which is liquid at 20 ° C and a solid epoxy resin which is solid at 40 ° C. Further, in the composition of the present invention, the ratio of the equivalent of the carboxyl group contained in the (A) carboxyl group-containing resin to the equivalent of the epoxy group contained in the (B) epoxy group-based thermosetting component is preferably 0.8. the following. Further, in the composition of the present invention, the (A) carboxyl group-containing resin is preferably derived from styrene or a styrene derivative.

Moreover, the dry film of the present invention is characterized in that it has a resin layer obtained by applying and drying the photosensitive resin composition of the present invention on a carrier film.

Further, the cured product of the present invention is characterized by the aforementioned tree of the photosensitive resin composition of the present invention or the dry film of the present invention described above. The lipid layer is obtained by hardening by light irradiation.

Moreover, the printed wiring board of the present invention is characterized by having the above-described cured product of the present invention.

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

30a‧‧‧Test tube for liquid determination

33a‧‧‧Rubber bolt

33b‧‧‧Rubber bolt

34‧‧‧ thermometer

31‧‧‧ marking

32‧‧‧ marking

30b‧‧‧Test tube for temperature measurement

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

[Best Mode for Carrying Out the Invention]

Embodiments of the present invention will be described in detail below.

First, each component of the photosensitive resin composition of the present invention will be described. Further, in the present specification, (meth) acrylate is a term generally referred to as acrylate, methacrylate, and a mixture thereof, and other similar expressions are also the same.

[(A) carboxyl group-containing resin]

The photosensitive resin composition of the present invention contains (A) a carboxyl group-containing tree fat. As the (A) carboxyl group-containing resin, a resin containing a conventional carboxyl group can be used. The composition can be made alkali-developable due to the presence of a carboxyl group. Further, from the viewpoint of the photocurability or the development resistance of the composition of the present invention, it is preferable to have an ethylenically unsaturated bond in the molecule in addition to the carboxyl group, but it is also possible to use only an ethylenically unsaturated double bond. A resin containing a carboxyl group. (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, it is preferable to suppress the effect of deterioration due to heat or light.

Specific examples of the carboxyl group-containing resin which can be used in the composition of the present invention include, for example, the following compounds (oligomers and polymers).

(1) A copolymer obtained by copolymerization of an unsaturated carboxylic acid such as (meth)acrylic acid with an unsaturated group-containing compound such as styrene, α-methylstyrene, lower alkyl (meth) acrylate or isobutylene Carboxyl resin. 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) a diisocyanate such as an aliphatic diisocyanate, a branched aliphatic diisocyanate, an alicyclic diisocyanate or an aromatic diisocyanate, and a carboxyl group-containing diol such as dimethylolpropionic acid or dimethylolbutanoic acid a compound, a polycarbonate-based polyol, a polyether-based polyol, a polyester-based polyol, a polyolefin-based polyol, an acrylic polyol, a bisphenol A-based alkylene oxide addition diol, and a phenolic hydroxyl group; A carboxyl group-containing urethane resin obtained by polyaddition reaction of a diol compound such as an alcoholic hydroxyl group compound. Where the carboxyl group-containing urethane resin has an aromatic ring, diisocyanate At least one of the ester, the carboxyl group-containing diol compound, and the diol compound may have an aromatic ring.

(3) a diisocyanate compound such as an aliphatic diisocyanate, a branched aliphatic diisocyanate, an alicyclic diisocyanate or an aromatic diisocyanate, and a polycarbonate polyol, a polyether polyol, a polyester polyol, A metal urethane having a polyaddition reaction of a diol compound such as a polyolefin-based polyol, an acrylic polyol, a bisphenol A-based alkylene oxide adduct diol, or a compound having a phenolic hydroxyl group or an alcoholic hydroxyl group A terminal carboxyl group-containing urethane resin obtained by reacting an acid anhydride with an acid anhydride. 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) Diisocyanate, bisphenol A epoxy resin, hydrogenated bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, bisphenol phenol epoxy resin, (meth)acrylate of a bifunctional epoxy resin such as a phenol type epoxy resin or a partial acid anhydride modified product thereof, a carboxyl group-containing diol compound, and a diol compound having a photosensitive carboxyl group-containing aminocarboxylic acid Ethyl resin. When the photosensitive carboxyl group-containing urethane resin has an aromatic ring, a diisocyanate, a bifunctional epoxy resin (meth) acrylate or a partial acid anhydride modified product thereof, a carboxyl group-containing diol compound, and a diol compound At least one of them has an aromatic ring.

(5) In the synthesis of the resin of the above (2) or (4), a compound having one hydroxyl group and one or more (meth)acryl fluorenyl groups in a molecule such as a hydroxyalkyl (meth) acrylate is added. A terminal (meth)acrylated carboxyl group-containing urethane resin. Photosensitive carboxyl group When the urethane resin has an aromatic ring, the compound having one hydroxyl group and one or more (meth) acryl fluorenyl groups in the molecule may have an aromatic ring.

(6) In the synthesis of the resin of the above (2) or (4), a molar reaction product such as isophorone diisocyanate and pentaerythritol triacrylate is added, and one isocyanate group and one or more molecules are contained in the molecule ( A methyl (meth) acrylate group-based compound, a terminal (meth) acrylated carboxyl group-containing urethane resin. When the photosensitive carboxyl group-containing urethane resin has an aromatic ring, the compound having one isocyanate group and one or more (meth) acrylonitrile groups in the molecule may have an aromatic ring.

(7) The addition of a polyfunctional epoxy resin to (meth)acrylic acid to form a hydroxyl group in the side chain, and the addition of a dibasic acid anhydride such as anhydrous phthalic acid, tetrahydroanhydrophthalic acid or hexahydroanhydrophthalic acid Photosensitive carboxyl resin. When the photosensitive carboxyl group-containing resin has an aromatic ring, at least one of the polyfunctional epoxy resin and the dibasic acid anhydride may have an aromatic ring.

(8) A photosensitive resin-containing resin obtained by reacting a hydroxyl group of a bifunctional epoxy resin with a polyfunctional epoxy resin epoxidized with epichlorohydrin and (meth)acrylic acid to form a dibasic acid anhydride in 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 polyfunctional oxetane resin is reacted with a dicarboxylic acid to form a carboxyl group-containing polyester resin of a dibasic acid anhydride in the resulting first-stage hydroxyl group. When the photosensitive carboxyl group-containing polyester resin has an aromatic ring, at least one of the polyfunctional oxetane resin, the dicarboxylic acid, and the dibasic acid anhydride has an aromatic group. Aroma ring can be.

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

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

(12) an epoxy compound having a plurality of epoxy groups in one molecule, and a compound having at least one alcoholic hydroxyl group and one phenolic hydroxyl group in one molecule such as p-hydroxyphenylethyl alcohol, and (meth) An unsaturated hydroxyl group-containing monocarboxylic acid such as acrylic acid is reacted to obtain an alcoholic hydroxyl group of the reaction product, and anhydrous maleic acid, tetrahydro anhydrous phthalic acid, anhydrous trimellitic acid, anhydrous pyromellitic acid, and A carboxyl group-containing photosensitive resin obtained by reacting a polybasic acid anhydride such as a diacid. When the photosensitive carboxyl group-containing polyester resin has an aromatic ring, the epoxy compound, at least one alcoholic hydroxyl group and one phenolic hydroxyl group in one molecule, and at least one unsaturated group-containing monocarboxylic acid and polybasic acid anhydride One type has an aromatic ring.

(13) The resin of any one of the above (1) to (12) further has a ring of a molecule such as glycidyl (meth) acrylate or α-methyl glycidyl (meth) acrylate. Photosensitive carboxyl-containing tree composed of an oxy group and one or more (meth) acrylonitrile-based compounds fat. When the photosensitive carboxyl group-containing urethane resin has an aromatic ring, the compound having one epoxy group and one or more (meth) acryl fluorenyl groups in the molecule may have an aromatic ring.

The above-mentioned carboxyl-containing resin is due to the backbone. The side chain of the polymer has a plurality of carboxyl groups and can be developed with a dilute aqueous alkali solution.

Further, in the above, the use of the (A) carboxyl group-containing resin derived from styrene or a styrene derivative is preferable because a composition excellent in 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. In the range of 20 to 200 mgKOH/g, the adhesion of the coating film can be obtained, the alkali development becomes easy, the dissolution of the exposed portion due to the developer is suppressed, and the line is not required to be thinned, and it is easy to draw normal. The resist pattern is good.

Further, although the weight average molecular weight of the carboxyl group-containing resin used in the present invention varies depending on the resin skeleton, it is preferably in the range of 2,000 to 150,000. When it is in this range, the peeling performance is good, the moisture resistance of the coating film after exposure is good, and film thinning is hard to occur at the time of image development. Moreover, in the range of the weight average molecular weight, the resolution is improved, the developability is good, and the storage stability is improved. More preferably 5,000 to 100,000. The weight average molecular weight can be determined by colloidal permeation chromatography.

[(B) Epoxy-based thermosetting component]

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

Examples of the polyfunctional epoxy compound include a bisphenol A type epoxy resin such as jER828 manufactured by Mitsubishi Chemical Corporation; a brominated epoxy resin; a novolak type epoxy resin; and a bisphenol F type epoxy resin; Hydrogenated bisphenol A type epoxy resin; glycidyl amine type epoxy resin; ethyl uret urea type epoxy resin; alicyclic epoxy resin; trishydroxyphenylmethane type epoxy resin; Mitsubishi Chemical Corporation YX-4000 and other bisphenol type or biphenol type epoxy resin or a mixture thereof; bisphenol S type epoxy resin; bisphenol A novolac type epoxy resin; DIC (share) RN- a cresol novolak type epoxy resin such as 695; a phenylol ethane type epoxy resin; a heterocyclic epoxy resin such as TEPIC manufactured by Nissan Chemical Industries Co., Ltd.; diglycidyl phthalic acid Acid ester resin; tetraglycidyl xylene decyl ethane resin; naphthyl containing epoxy resin; epoxy resin having dicyclopentadiene skeleton; soft and strong epoxy resin; glycidyl methacrylate copolymerization Epoxy resin; copolymerization of cyclohexylmaleimide with glycidyl methacrylate Epoxy resin, etc., but is not limited thereto and other persons. These epoxy resins may be used singly or in combination of two or more kinds. Among these, a bifunctional epoxy resin is preferred from the viewpoint of flexibility. In particular, a biphenyl novolac type epoxy resin, a bisxylenol type epoxy resin or a mixture thereof is preferred from the viewpoint of flame retardancy.

In the present invention, the amount of the (B) epoxy group-based thermosetting component is 1 equivalent to the carboxyl group contained in the (A) carboxyl group-containing resin. (B) The equivalent of the epoxy group contained in the epoxy group thermosetting component needs to be in the range of 1.0 or less. The ratio of the equivalent of the carboxyl group contained in the (A) carboxyl group-containing resin to the equivalent of the epoxy group contained in the (B) epoxy-based thermosetting component is preferably 0.1 or more and 0.8 or less, particularly preferably 0.2 or more and 0.6 or less. The scope. Here, in the present invention, the equivalents of the carboxyl group and the epoxy group refer to the chemical equivalents of the carboxyl group and the epoxy group each as a reactive group. In the present invention, the number of epoxy groups of the (B) epoxy group-containing thermosetting component contained in the composition (dry coating film) is smaller than the number of carboxyl groups of the (A) carboxyl group-containing resin.

In general, the amount of the (B) epoxy group-based thermosetting component is a range in which the carboxyl group in the cured film can be prevented from remaining. However, in the present invention, (B) epoxy group thermosetting property in the composition is obtained. When the amount of the component is in the above range, the number of the epoxy groups to be reacted is small relative to the number of carboxyl groups, and the carboxyl group imparting developability can be left in a large amount after thermal curing. As a result, even if it is a hardened film containing titanium oxide, the solubility in a developing solution can be improved, and generation of development residue can be suppressed in a hole portion such as a through hole. Further, in the present invention, the hole portion such as the through hole or the like is not limited to the through hole, and is a hole portion which also includes a via hole or the like. The more the small-diameter residue is more likely to be clogged, the smaller the diameter portion of the inner diameter of 300 mm or less, specifically the inner diameter of 200 mm or more and 300 mm or less, can be developed without causing residue.

In the present invention, the (B) epoxy group-based thermosetting component is preferably at least one selected from the group consisting of an epoxy resin which is liquid at 20 ° C and a solid epoxy resin which is solid at 40 ° C. Here, the solid form in the present invention contains the concept of a powder. (B) epoxy-based thermosetting When the component contains an epoxy resin which is liquid at 20 ° C, the viscosity is low and it is easy to flow, so that the development residue in the through hole is less likely to occur. In addition, the (B) epoxy group-based thermosetting component contains a solid epoxy resin which is a powder at 40 ° C, and is in a granular form and is less likely to be clogged in the through-hole, and the development residue is less likely to occur. Further, when the (B) epoxy-based thermosetting component contains a solid epoxy resin which is solid at 40 ° C, it is granular like the powder and is not easily clogged in the through-hole, so development The residue becomes less likely to occur. On the other hand, in the case where the epoxy resin having a semi-solid shape in the temperature at the time of development is in a state of being between the solid state and the liquid state, and the viscosity is high, the development residue easily enters the through-hole and is considered to be in a state in which it is difficult to discharge. In recent years, with the miniaturization of the substrate, the size of the through hole has also become smaller, so that such a phenomenon is particularly likely to occur.

Here, a method of determining the "liquid state" in the present invention will be described.

The determination of the liquid state is carried out in accordance with the "Method for Confirming the Liquidity" in the second part of the annex to the "Procedures for the Test of the Hazardous Substances".

(1) device Constant temperature sink:

Use a mixer, heater, thermometer, automatic temperature regulator (can control temperature at ±0.1 °C) and a depth of 150mm or more.

Moreover, in the determination of the epoxy resin used in the examples described later, a low-temperature constant temperature water tank (type BU300) manufactured by Yamato Scientific Co., Ltd. was used. Put the combination of the input thermostat thermometer (type BF500), and put about 22 liters of tap water into the low temperature constant temperature water tank (type BU300), and turn on the power supply of the thermometer (type BF500) combined with it, and set it to the set temperature (20 °C or 40). °C), the water temperature is finely adjusted with a thermometer (type BF500) at a set temperature of ±0.1 °C, but it can be used if it can be adjusted similarly.

Test tube:

As for the test tube, as shown in Fig. 1, a flat-bottom cylindrical transparent glass having an inner diameter of 30 mm and a height of 120 mm is used, and the marking lines 31, 32 are respectively set at the heights of 55 mm and 85 mm from the bottom of the tube, and the test tube is placed. The test tube 30a for liquid determination which is sealed by the rubber plug 33a is provided with the same size and the same reticle, and the test tube is sealed by a rubber plug 33b for inserting and supporting the hole of the thermometer at the center. The rubber plug 33b is inserted into the temperature measuring test tube 30b of the thermometer 34. Hereinafter, the line from the height of 55 mm at the bottom of the tube is "A line", and the line at the height of 85 mm from the bottom of the tube is "B line".

In the case of the thermometer 34, the freeze point measurement target (SOP-58 scale range: 20 to 50 ° C) specified in JIS B7410 (1982) "Glass thermometer for petroleum test" is used, but the temperature range of 0 to 50 ° C can be measured. can.

(2) Means of implementation of the test

The sample which was allowed to stand at atmospheric pressure of 20 ± 5 ° C for 24 hours or more was placed in the test tube 30a for liquid determination shown in Fig. 1 (a) and Fig. 1 The temperature measuring test tubes 30b shown in (b) are each up to the A line. The two test tubes 30a and 30b were stood upright in a low-temperature constant temperature water tank so that the B line was below the water surface, and then allowed to stand. The thermometer has a lower end 30 mm lower than the A line.

After the sample temperature reached the set temperature ±0.1 ° C, it was maintained in this state for 10 minutes. After 10 minutes, the liquid test tube 30a was taken out from the low-temperature constant temperature water tank, and immediately fell horizontally on the horizontal test stand. The time at which the liquid level front end of the test tube was moved from the A line to the B line was measured and recorded by a horse watch. The sample was judged to be in a liquid state within 90 seconds after the measurement at the set temperature, and was judged to be solid when it was over 90 seconds.

Examples of the epoxy resin which is liquid at 20 ° C include bisphenol A type epoxy resin such as jER828 manufactured by Mitsubishi Chemical Corporation, bisphenol F type epoxy resin, phenol novolak type epoxy resin, tert a butyl-catechol type epoxy resin, a glycidyl amine type epoxy resin, an aminophenol type epoxy resin, an alicyclic epoxy resin, or the like. Further, the epoxy resin which is liquid at 20 ° C may of course be liquid at less than 20 ° C. Further, in terms of the epoxy resin, an aromatic epoxy resin is preferred from the viewpoint of preferable physical properties of the cured product and the like. In the present specification, the aromatic epoxy resin refers to an epoxy resin having an aromatic ring skeleton in its molecule. Therefore, in terms of a liquid epoxy resin at 20 ° C, an aromatic epoxy resin which is liquid at 20 ° C is more preferable. These epoxy resins may be used singly or in combination of two or more.

The solid epoxy resin which is solid at 40 ° C may, for example, be a tetrafunctional naphthalene type epoxy resin or a naphthalene type epoxy resin containing a naphthalene skeleton polyfunctional solid epoxy resin; a phenol and an aromatic having a phenolic hydroxyl group; Epoxide of a condensate of an aldehyde (trisphenol type epoxy resin); containing dicyclopentadiene bone a dicyclopentadiene aralkyl type epoxy resin such as a polyfunctional solid epoxy resin; a biphenyl aralkyl type epoxy resin containing a biphenyl skeleton polyfunctional solid epoxy resin; a novolac type ring Oxygen resin; a bisphenol type or a biphenol type epoxy resin such as YX-4000 manufactured by Mitsubishi Chemical Co., Ltd. or a mixture thereof; a cresol novolak type ring of RN-695 manufactured by DIC Co., Ltd. Oxygen resin; heterocyclic epoxy resin such as TEPIC manufactured by Nissan Chemical Industries Co., Ltd. These epoxy resins may be used singly or in combination of two or more kinds. In particular, in order to impart low thermal expansion properties, it is preferred to use an epoxy resin having a naphthalene skeleton.

The semi-solid epoxy resin (C) which is solid at 20 ° C and liquid at 40 ° C may, for example, be a bisphenol A epoxy resin; a naphthalene epoxy resin; a phenol novolak epoxy resin; . These epoxy resins may be used singly or in combination of two or more kinds.

[(C) Inorganic Filler]

The alkali-developable photosensitive resin composition of the present invention contains (C) an inorganic filler. (C) inorganic fillers, for example, calcium carbonate, magnesium carbonate, fly ash, dewatered sludge, natural cerium oxide, synthetic cerium oxide, kaolin, clay, calcium oxide, magnesium oxide, titanium oxide, zinc oxide, Barium sulfate, alumina, talc, mica, magnesite, aluminum citrate, magnesium citrate, calcium citrate, calcined talc, ash, potassium titanate, magnesium sulfate, calcium sulfate, magnesium phosphate, sea Asphalt, ettringite, boron nitride, aluminum borate, cerium oxide sphere, glass flake, glass sphere, amorphous cerium oxide, crystalline cerium oxide, molten cerium oxide, spherical cerium oxide, iron making Slag, copper, Iron, iron oxide, carbon black, aluminum strontium iron powder, AlNiCo magnet, magnetic powder of various ferrite grains, cement, glass powder, Neuburg alumina, diatomaceous earth, antimony trioxide, magnesium sulfate sulfate, hydration Aluminum, hydrated gypsum, alum, etc. These inorganic fillers may be used alone or in combination of two or more.

In the above, in the present invention, the inorganic filler (C) contains titanium oxide. By containing titanium oxide as the (C) 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 that development residue tends to occur in a through-hole or the like due to a decrease in fluidity, but in the present invention, a carboxyl group contained in (A) a carboxyl group-containing resin And the equivalent ratio of the epoxy group contained in the (B) epoxy-based thermosetting component is within the above-specified range, and a cured film having no problem of development residue and high reflectance can be obtained.

The titanium oxide may be titanium oxide of any of a rutile type, an anatase type, and a stellite type. The smectite-type titanium oxide can be obtained by subjecting the smectite-type Li _0.5 TiO ₂ to a chemical oxidative lithium detachment treatment. The rutile-type titanium oxide is excellent in discoloration caused by light irradiation.

The amount of the (C) inorganic filler containing the titanium oxide as an essential component is preferably a solid content in the photosensitive resin composition (a component other than the organic solvent when the photosensitive resin composition contains an organic solvent). It is in the range of 5 to 80% by mass, more preferably in the range of 10 to 70% by mass.

[(D) Photopolymerization initiator]

The alkali-developable photosensitive resin composition of the present invention contains (D) a photopolymerization initiator. (D) In terms of a photopolymerization initiator, a photopolymerization initiator or a photoradical generator can be used as a conventional photopolymerization initiator.

(D) Photopolymerization initiator, for example, bis-(2,6-dichlorobenzhydryl)phenylphosphine oxide, bis-(2,6-dichlorobenzhydryl)-2,5- Dimethylphenylphosphine oxide, bis-(2,6-dichlorobenzylidene)-4-propylphenylphosphine oxide, bis-(2,6-dichlorobenzhydryl)-1 -naphthylphosphine oxide, bis-(2,6-dimethoxybenzylidene)phenylphosphine oxide, bis-(2,6-dimethoxybenzylidene)-2,4, 4-trimethylpentylphosphine oxide, bis-(2,6-dimethoxybenzylidene)-2,5-dimethylphenylphosphine oxide, bis-(2,4,6- Trimethyl benzhydryl)-phenylphosphine oxide (bismuthylphosphine oxides such as BASF Japan, IRGACURE 819); 2,6-dimethoxybenzimidyl diphenylphosphine Oxide, 2,6-dichlorobenzhydryldiphenylphosphine oxide, 2,4,6-trimethylbenzimidylphosphonic acid methyl ester, 2-methylbenzhydryldiyl Phenylphosphine oxide, isopropyl trimethyl ethenylphenylphosphonate, 2,4,6-trimethylbenzimidyl diphenylphosphine oxide (manufactured by BASF Japan, DAROCUR TPO) And other monodecylphosphine oxides; 1-hydroxy-cyclohexyl phenyl ketone, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2- Base-1-propan-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propenyl)-benzyl]phenyl}-2-methyl-propane Hydroxyacetophenones such as 1-ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one; benzoin, benzyl ester, benzoin methyl ether, benzoin ethyl ether, benzoin n- Benzoin, benzoin isopropyl ether, benzoin n-butyl ether, etc.; benzoin alkyl ether; benzophenone, p-methylbenzophenone, Michler, methyl diphenyl a benzophenone such as a ketone, 4,4'-dichlorobenzophenone or 4,4'-bisdiethylaminobenzophenone; acetophenone, 2,2-dimethoxy- 2-Phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1 -[4-(Methylthio)phenyl]-2-morpholinyl-1-propanone, 2-benzyl-2-dimethylamino-1-(4-morpholinylphenyl)-butyl Acetophenones such as ketone-1, N,N-dimethylaminoacetophenone, thioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-diisopropylthioxanthene Sulphur-based xanthone ketones; hydrazine, chloranil, 2-methyl hydrazine, 2-ethyl hydrazine, 2-tert-butyl hydrazine, 1-chloroindole, 2-pentyl hydrazine Anthraquinones such as hydrazine, 2-aminoindole, etc.; ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; ethyl-4-dimethylamino benzoate , benzoic acid esters such as 2-(dimethylamino)ethyl benzoate, ethyl p-dimethylbenzoate; 1.2-octanedione, 1-[4-(phenyl sulfonate) Base, -, 2-(O-benzylidene hydrazide)], ethyl ketone, 1-[9-ethyl-6-(2-methylbenzhydryl)-9H-indazol-3-yl] - an oxime ester such as 1-(0-ethenylhydrazine); bis(η ⁵ -2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H) -pyrrol-1-yl)phenyl)titanium, bis(cyclopentadienyl)-bis[2,6-difluoro-3-(2-(1-pyrrol-1-yl)ethyl)phenyl] Titanium such as titanium; phenyl disulfide 2-nitroguanidine, butyl acetoin, fennel acetoyl ethyl ether, azobisisobutyronitrile, tetramethyl thiuram disulfide, and the like. The above photopolymerization initiators may be used alone or in combination of two or more.

(D) The amount of photopolymerization initiator is converted in solid form, It is 0.1 to 50 parts by mass based on 100 parts by mass of the (A) carboxyl group-containing resin. When the (D) photopolymerization initiator is blended in this range, the photocurability on copper is sufficient, the curability of the coating film is improved, the coating properties such as chemical resistance are improved, and deep hardening is performed. Sex 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 to adjust the viscosity of the composition to improve the workability, to increase the crosslinking density, to improve the adhesion, and the like, and to use a reactive diluent such as a photocurable monomer or a conventional one. Organic solvents.

Examples of the photocurable monomer include alkyl (meth) acrylates such as 2-ethylhexyl (meth) acrylate and cyclohexyl (meth) acrylate; and 2-hydroxyethyl (methyl) a hydroxyalkyl (meth) acrylate such as acrylate or 2-hydroxypropyl (meth) acrylate; or a single alkylene oxide derivative such as ethylene glycol, propylene glycol, diethylene glycol or dipropylene glycol; Or di(meth)acrylates; polyols such as hexanediol, trimethylolpropane, pentaerythritol, ditrimethylolpropane, dipentaerythritol, hydroxyethyl isocyanurate or the like Polyvalent (meth) acrylates of ethylene oxide or propylene oxide adducts; phenoxyethyl (meth) acrylate, bisphenol A polyethoxy di(meth) acrylate, etc. (meth)acrylates of phenolic oxirane or propylene oxide adducts; glycerol diglycidyl ether, trimethylolpropane triglycidyl ether, triglycidyl isocyanuric acid Epoxy propyl ether of ester or the like (methyl) Acrylates; and melamine (meth) acrylates, and the like.

The ratio of the photocurable monomer is preferably from 5 to 100 parts by mass, more preferably from 5 to 70 parts by mass, per 100 parts by mass of the carboxyl group-containing resin (A). In the range of the above matching ratio, the photocurability is improved, the pattern formation is easy, and the strength of the cured film can be improved.

As the organic solvent, a ketone such as methyl ethyl ketone or cyclohexanone; an aromatic hydrocarbon such as toluene, xylene or tetramethylbenzene; a cellosolve, a methyl cellosolve or a butyl cellosolve; Glycol ethers such as carbitol, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether, tripropylene glycol monomethyl ether; acetic acid Ethyl ester, butyl acetate, butyl lactate, cellulose acetate, cellulose butyl acetate, carbitol acetate, butyl carbitol acetate, propylene glycol monomethyl ether acetate, two An ester of propylene glycol monomethyl ether acetate or propylene carbonate; an aliphatic hydrocarbon such as octane or decane; a petroleum solvent such as petroleum ether, naphtha or petroleum scouring oil; Organic solvents. These organic solvents may be used singly or in combination of two or more kinds.

(other optional ingredients)

The composition of the present invention can be used with additives conventionally used in the field of electronic materials. Examples of the additive include a thermosetting catalyst, a thermal polymerization inhibitor, a UV absorber, a decane coupling agent, a plasticizer, a flame retardant, an antistatic agent, an aging preventive agent, and an antibacterial agent. A mold inhibitor, an antifoaming agent, a flat agent, a filler other than the above, a tackifier, an adhesion imparting agent, a shake imparting agent, a coloring agent, a photoinitiating aid, a sensitizer, and the like.

(flammable agent)

The photosensitive resin composition of the present invention may contain a flame retardant such as a phosphorus-containing compound. In the case where the photosensitive resin composition of the present invention contains a solid flame retardant, generation of development residue in the cavity portion can be suppressed. As the flame retardant, a conventional person such as a metal hydroxide or a phosphorus-containing compound can be used. As the metal hydroxide, for example, aluminum hydroxide, calcium hydroxide, magnesium hydroxide or the like. Examples of the phosphorus-containing compound include a phosphate ester, a condensed phosphate ester, a cyclic phosphazene compound, a phosphorus-containing compound having a phenolic hydroxyl group, a phosphorus-containing compound of an oligomer or a polymer, a phosphazene oligomer, and a phosphine. An acid metal salt, a compound represented by the following general formula, and the like.

In the above general formula, R ⁷ , R ⁸ and R ⁹ are each independently a substituent other than a halogen atom. In the general 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} a hydrogen atom, an alkyl group having 1 to 4 carbon atoms which may be substituted by a cyano group, 2,5- Dihydroxyphenyl or 3,5-di-t-butyl-4-phenylphenyl is preferred.

In the case of a phosphazene oligomer, a phenoxyphosphazene compound is effective, and a substituted or unsubstituted phenoxyphosphazene oligomer, or a ring of a 3mer, a 4mer, or a 5mer .

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

The dry film of the present invention has a resin layer obtained by coating and drying the composition of the present invention on a carrier film (support). The formation of the dry film is carried out by diluting the composition of the present invention with the above organic solvent to an appropriate viscosity, and using a notch wheel coater, a knife coater, a lip coater, a bar coater, and a squeeze. A press coater, a reverse coater, a transfer roll coater, a gravure coater, a spray coater or the like is applied to a carrier film to a uniform thickness. Thereafter, the applied composition is usually dried at a temperature of 50 to 130 ° C for 1 to 30 minutes to form a resin layer. The coating film thickness is not particularly limited, and the film thickness after drying is generally 10 to 150 μm, preferably 20 to 60 μm.

For the carrier film, a plastic film can be used, and a plastic film such as polyethylene terephthalate, a polyimide film, a polyimide film, a polypropylene film, a polystyrene film, or the like can be used. The film is preferred. The thickness of the carrier film is not particularly limited, and is generally selected in the range of 10 to 150 μm.

After the resin layer composed of the composition of the present invention is formed on the carrier film, the dust is prevented from adhering to the surface of the film or the like, and further, a cover film which is peelable on the surface of the film is preferably laminated. As the peelable cover film, for example, a polyethylene film, a polytetrafluoroethylene film, a polypropylene film, a surface-treated paper, or the like can be used. In the case of covering the film, when the cover film is peeled off, the adhesion force between the resin layer and the carrier film is smaller. should.

Further, the composition of the present invention is adjusted to have a viscosity suitable for the coating method using, for example, the above-mentioned organic solvent, and is subjected to a dip coating method, a shower coating method, a roll coating method, a bar coating method, a screen printing method, or the like on a substrate. After coating by a method such as a curtain coating method, the organic solvent contained in the composition is volatilized and dried (temporarily dried) at a temperature of about 60 to 100 ° C to form a resin layer which does not peel off. Further, when the composition is applied onto a carrier film, dried, and wound into a dry film of a film, the layer of the composition of the present invention is brought into contact with the substrate by a laminator or the like to be bonded to the substrate. After the material is applied, the carrier film is peeled off to form a resin layer.

The substrate is a paper phenol, a paper epoxy ester, a glass epoxy ester, a glass polyimide, a glass cloth/non-woven fabric, in addition to a printed wiring board or a flexible printed wiring board in which a circuit is formed in advance. Epoxy esters, glass cloth / paper epoxy esters, synthetic fiber epoxy esters, using fluorine. Polyethylene. Polyphenylene ether, polyphenylene oxide. For the material such as a copper-clad laminate for a high-frequency circuit such as a cyanate ester, for example, a copper-clad laminate of all grades (such as FR-4), another polyimide film, a PET film, a glass substrate, or a ceramic substrate can be used. , wafer board, etc.

The volatilization drying after the application of the composition of the present invention can be carried out by using a hot air circulation type drying furnace, an IR furnace, a heating plate, a convection oven or the like (using a heat source having a vapor heating method to make the hot air in the dryer countercurrent contact) The method and the method of blowing the support by a nozzle are performed.

The composition of the present invention is heat-hardened by, for example, heating to a temperature of about 140 to 180 ° C to form heat resistance, chemical resistance, and moisture absorption resistance. A cured coating film excellent in properties such as properties, adhesion, and electrical properties.

Moreover, the resin layer obtained by applying the composition of the present invention and evaporating and drying the solvent is exposed (light irradiation), and the exposed portion (light-irradiated portion) is cured. Specifically, in a contact or non-contact manner, through the formation of a pattern mask, selective exposure with an active energy line, or direct pattern exposure by a laser direct exposure machine, the unexposed portion is a dilute aqueous solution (for example, 0.3 to 3 wt% aqueous sodium carbonate solution) is developed to form a resist pattern.

The exposure machine used for the active energy ray irradiation is a device that is equipped with a high-pressure mercury lamp, an ultra-high pressure mercury lamp, a metal halide lamp, a mercury short-arc lamp, and the like, and is irradiated with ultraviolet rays in the range of 350 to 450 nm. Further, it may be used directly. A rendering device (eg, a laser direct imaging device that draws images with direct lasers from CAD data from a computer). For the laser source of the direct-drawing machine, laser light with a maximum wavelength of 350-410 nm can be used for both gas laser and solid laser. The amount of exposure for image formation varies depending on the film thickness, etc., and is generally in the range of 20 to 800 mJ/cm ² , preferably 20 to 600 mJ/cm ² .

In the above development method, a dipping method, a rinsing method, a spraying method, a brush method, or the like can be used, and in terms of a developing solution, potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium citrate, ammonia can be used. An aqueous solution of an alkali such as an amine.

The composition of the present invention is suitable for formation of a hard coat film such as a solder resist or an interlayer insulating layer of a printed wiring board or a flexible printed wiring board. Moreover, the composition of the present invention is made into a white, in a lighting fixture or line A backlight of a liquid crystal display such as a mobile terminal, a computer, or a television is applied to a reflector that reflects light emitted from a light-emitting diode (LED) or an electroluminescence (EL) used as a light source.

[Examples]

Hereinafter, the present invention will be described in more detail using an embodiment.

According to the combination shown in the following table, each component was mixed and premixed with a stirrer, and then dispersed and kneaded in a 3-roll mill to prepare respective compositions. Also, the amount of matching in the table is parts by mass.

<Synthesis Example 1 (Preparation of a carboxyl group-containing resin)>

In a four-necked flask equipped with a reflux condenser, a thermometer, a glass tube for nitrogen substitution, and a stirrer, 42 parts by mass of methacrylic acid, 43 parts by mass of methyl methacrylate, 35 parts by mass of styrene, and benzyl acrylate 35 were added. Parts by mass, 100 parts by mass of carbitol acetate, 0.5 parts by mass of lauryl mercaptan, and 4 parts by mass of azobisisobutyronitrile, heated under nitrogen flow at 75 ° C for 5 hours to obtain a copolymer solution (solid form) The concentration is 50% by mass). To the mixture, 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 the addition reaction was carried out at 80 ° C for 24 hours, followed by the addition of carbitol acetic acid. 35 parts by mass of the ester gave a copolymerized resin solution having an aromatic ring (solid content concentration: 50% by mass).

<developability (through hole developability)>

On a 1.0mm thick copper clad laminate 300μm drill hole is opened, and the through hole is plated by a prescribed method, and the formed value is formed. A substrate of 100 holes through a hole of 260 μm. The composition of each of the examples and the comparative examples was printed twice by screen printing on the substrate, and dried in a hot air circulating drying oven at 80 ° C for 30 minutes, and allowed to cool to room temperature. This substrate was developed using a 1% by mass aqueous sodium carbonate solution at 30 ° C for 90 seconds under the conditions of a spray pressure of 0.2 MPa, and washed with water to obtain a substrate after development. The inside of the through-hole of the obtained substrate was visually observed and observed under a microscope, and the developability in the through-hole was evaluated. The case where there is no development residue is evaluated as ◎, the case where the development residue is slightly evaluated is ○, and the development residue is evaluated as △ when the through-hole is penetrated, and the development residue is not penetrated when the through-hole is not penetrated.

<reflectance>

The composition of each of the examples and the comparative examples was applied to a FR-4 copper-clad laminate having a thickness of 100 mm × 150 mm and a thickness of 1.6 mm by using a screen printing method to have a film thickness of 40 μm, and 100 mesh polyester was used. The version of the system is printed in Beta (full substrate). These were dried at 80 ° C for 30 minutes in a hot air circulating drying oven. Further, ultraviolet light exposure was performed at a cumulative light amount of 900 mJ/cm ^{2 in a} manner of leaving a 30 mm square negative pattern by using an exposure machine HMW-680GW (manufactured by ORC MANUFACTURING CO., LTD.). Thereafter, a 1% sodium carbonate aqueous solution was used as a developing solution at 30 ° C, and these were developed by a developing machine for 60 seconds in a printed wiring board, followed by thermal hardening in a hot air circulating drying oven at 150 ° C for 60 minutes. A test piece for the characteristic test was produced.

The obtained test piece was measured by a color difference meter CR-400 (KONICA MINOLTA SENSING, INC.), and when the value of the Y value was 85 or more, it was evaluated as ○, and when it was 80 or more, the evaluation was △. If the number is less than 80, it is evaluated as ×.

<Solder heat resistance>

The test piece coated with the rosin-based flux was immersed once in a solder bath set at 260 ° C for 30 seconds, and the flux was washed with a modified alcohol, and the peeling of the resist layer was visually evaluated. The case where no peeling occurred was evaluated as ○, the case where some peeling occurred was evaluated as Δ, and the case where peeling was remarkably marked was evaluated as ×.

The above evaluation results are shown in the following table.

*1) The carboxyl group-containing resin (carboxy equivalent = 960)*2) derived from the styrene obtained in Synthesis Example 1 was diluted with DPM (dipropylene glycol monomethyl ether) to 44% by mass (DICEL Chemical Industry Co., Ltd.) (Resin containing carboxyl group, carboxyl equivalent = 806) *3) Bisphenol A type epoxy resin, manufactured by Mitsubishi Chemical Corporation (liquid at 20 ° C, epoxy equivalent = 185) *4) Nissan Chemical Industry (stock) system (powder (solid) at 40 ° C, epoxy equivalent = 100) * 5) biphenyl type epoxy resin (manufactured by Mitsubishi Chemical Corporation) ( powder at 40 ° C (solid) (form)), epoxy equivalent = 182) * 6) cresol novolac type epoxy resin (made by DIC) (solid at 40 ° C, epoxy equivalent = 210) * 7) Ishihara Industry Co., Ltd. *8) Showa Denko Electric Co., Ltd. ※9) Aluminum phosphonate, manufactured by Clariant Japan Co., Ltd. *10) Monodecylphosphine oxide photopolymerization initiator, Lucirin TPO (2,4,6- Trimethyl benzhydryl-diphenyl-phosphine oxide), manufactured by BASF Japan Co., Ltd. *11) bis-decylphosphine oxide photopolymerization initiator, IRGACURE 819 (double (2, 4, 6-three) Methyl benzhydryl)-phenylphosphine oxide, manufactured by BASF Japan Co., Ltd. *12) Imidazole compound, Shikoku Chemical Industry Co., Ltd.*13) Ethylene glycol monomethyl ether acetate ※14) Aromatic hydrocarbons (SOLVESSO 150) ※15) Dipentaerythritol hexaacrylate, Kyoeisha Chemical Co., Ltd. *16) Composition in dry state (solid content conversion) The ratio of the equivalent (number) of the carboxyl group contained in the (A) carboxyl group-containing resin to the equivalent (number) of the epoxy group contained in the epoxy group thermosetting component (the number of epoxy groups / carboxyl group) number).

From the results of the above-mentioned table, it is understood that the composition of each of the examples does not cause development residue in the through-holes even when titanium oxide is contained, and the solder heat resistance is also good. As a result, according to the present invention, it was confirmed that a photosensitive resin composition having good through-hole developability and high reflectance can be obtained.

Claims (7)

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 And the equivalent of the epoxy group contained in the (B) epoxy group-containing thermosetting component is 1.0 or less, and the above (C) The inorganic filler contains titanium oxide. The photosensitive resin composition according to claim 1, wherein the (B) epoxy-based thermosetting component contains an epoxy resin which is liquid at 20 ° C and a solid epoxy resin which is solid at 40 ° C. At least one or more. The photosensitive resin composition according to claim 1 or 2, wherein the equivalent of the carboxyl group contained in the (A) carboxyl group-containing resin is equivalent to the epoxy group contained in the (B) epoxy-based thermosetting component. The ratio is 0.8 or less. The photosensitive resin composition according to any one of claims 1 to 3, wherein the (A) carboxyl group-containing resin is styrene or a styrene derivative. A dry film obtained by applying the photosensitive resin composition according to any one of claims 1 to 4 to a carrier film and drying the obtained resin layer. A cured product obtained by curing the photosensitive resin composition according to any one of claims 1 to 4 or the resin layer of the dry film described in claim 5 by light irradiation. A printed wiring board characterized by having the cured product described in claim 6.