TW202426518A - Photosensitive thermosetting developing resin composition, its dry film and hardened product, and printed circuit board formed using the same - Google Patents

Abstract

The present invention provides a photosensitive thermosetting developing resin composition which has excellent printability and can form a solder resist layer having excellent hardness and resistance to cold and hot shocks, a dry film thereof, a cured product thereof, and a printed circuit board formed using the same. The photosensitive thermosetting developing resin composition is characterized in that it contains (A) a vinyl ester resin, (B) a photopolymerization initiator, (C) a phosphate ester dispersant, (D) a compound having two or more ethylenically unsaturated groups in one molecule, and (E) an inorganic filler, wherein the (C) phosphate ester dispersant comprises a polymer having a phosphate ester structure in the main chain (C-1), and the (E) inorganic filler comprises talc and silica, and the total amount of the talc and the silica is 50 to 180 parts by weight relative to 100 parts by weight of the vinyl ester resin (A) calculated as a solid component, and the ratio of the talc is 20 to 80% by weight based on the total weight of the talc and the silica being 100% by weight.

Description

Photosensitive thermosetting developing resin composition, its dry film and hardened product, and printed circuit board formed using the same

The present invention relates to a photosensitive thermosetting developing resin composition suitable for forming a solder resist or the like of a printed circuit board, a dry film thereof and a cured product thereof, and in particular to a photosensitive thermosetting developing resin composition which has excellent printability and can form a solder resist layer having excellent hardness and resistance to cold and hot shocks, a dry film thereof and a cured product thereof, and a printed circuit board.

Currently, alkaline developing type solder resists are used in some consumer printed circuit boards and almost all industrial printed circuit boards, which are exposed to ultraviolet light and then developed to form an image, and are completely cured (primary cure) by heat and/or light irradiation. In addition, in semiconductor devices used in vehicles such as automobiles, trains, ships, and airplanes, there is a tendency to use solder resists for high-reliability electronic materials as printed circuit board solder resists.

However, conventional alkali-developable solder resist inks usually have poor resistance to hot and cold shock cracking due to thermal expansion and contraction, and poor reliability for changes in ambient temperature. Although talc can be used as a filler to improve the cracking, the printability and hardness are poor. Alternatively, talc and barium sulfate are used as fillers to meet the requirements for hot and cold shock resistance of solder resist inks for automotive use, but the printability and hardness are deteriorated.

For example, the fillers in the photocurable solder resist ink of Patent Document 1 include silicon dioxide, barium sulfate and talc. The curable resin composition for the solder resist layer of Patent Document 2 contains a carboxyl resin, a thermosetting component, a flame retardant and an ion scavenger, wherein the ion scavenger is a mixture of a hydrotalcite-based ion scavenger and an ion scavenger other than the hydrotalcite-based ion scavenger, and the inorganic filler is aluminum hydroxide. The curable resin composition of Patent Document 3 is used for a permanent mask of a printed circuit board, and includes: a resin containing an olefinic unsaturated group and a carboxyl group in the molecule, a photopolymerization initiator, a photopolymerizable monomer, titanium oxide surface-treated with aluminum oxide, barium sulfate and/or talc, and an organic solvent. Patent document 4 states that the filler of the UV-curable liquid photosensitive solder resist soft board ink is barium sulfate, talcum powder or silicon dioxide. [Prior technical document]

[Patent document] [Patent document 1] CN114716868A [Patent document 2] CN108137791A [Patent document 3] CN101798432A [Patent document 4] CN106380929A

[The problem that the invention wants to solve]

The purpose of the present invention is to improve the printability of solder resist ink and the hardness of the dry film and cured product formed therefrom, and to further improve the long-term reliability. More specifically, the purpose of the present invention is to provide a photosensitive thermosetting developing resin composition having excellent printability and capable of forming a solder resist layer having excellent hardness and resistance to cold and hot shocks, its dry film and its cured product, and a printed circuit board. [Means for Solving the Problem]

The inventors of the present invention have conducted repeated and in-depth research to solve the above-mentioned problem and found that the types of fillers and additives have a great influence on the resistance to cold and hot shock. The photosensitive thermosetting developing resin composition described below can solve the above problems, thereby completing the present invention. The photosensitive thermosetting developing resin composition is characterized in that it contains (A) a vinyl ester resin, (B) a photopolymerization initiator, (C) a phosphate ester dispersant, (D) a compound having two or more ethylenically unsaturated groups in one molecule, and (E) an inorganic filler. The (C) phosphate ester dispersant contains (C-1) a polymer having a phosphate ester structure in the main chain, and the (E) inorganic filler contains talc and silica. The total amount of talc and silica is 50 to 180 parts by weight relative to 100 parts by weight of the vinyl ester resin (A) calculated as a solid component. The ratio of talc is 20 to 80% by weight based on the total weight of talc and silica being 100% by weight.

That is, the photosensitive thermosetting developing resin composition of the present invention is characterized in that it contains (A) a vinyl ester resin, (B) a photopolymerization initiator, (C) a phosphate ester dispersant, (D) a compound having two or more ethylenically unsaturated groups in one molecule, and (E) an inorganic filler, wherein the (C) phosphate ester dispersant comprises a polymer having a phosphate ester structure in the main chain (C-1), and the (E) inorganic filler comprises talc and silica, and the total amount of talc and silica is 50 to 180 parts by weight relative to 100 parts by weight of the vinyl ester resin (A) calculated as a solid component, and the ratio of talc is 20 to 80% by weight based on the total weight of talc and silica being 100% by weight.

Furthermore, it is preferred to contain (F) other additives in addition to (B) the photopolymerization initiator and (C) the phosphate ester dispersant.

Furthermore, it is preferred to contain (G) an epoxy resin.

Furthermore, it is preferred to contain (H) an organic solvent.

Furthermore, it is preferred that the (C) phosphate ester-based dispersant further comprises (C-2) a polymer having a phosphate ester structure in a side chain.

Furthermore, the dry film of the present invention is characterized in that it is obtained by coating the photosensitive thermosetting developing resin composition on a carrier film and drying it.

In addition, the cured product of the present invention is characterized in that it is obtained by photocuring the following coating, wherein the coating is: a coating obtained by applying the photosensitive thermosetting developing resin composition on copper and drying; or a coating obtained by applying the photosensitive thermosetting developing resin composition on a carrier film and drying, and pressing the obtained photocurable dry film layer on copper.

In addition, the printed circuit board of the present invention is characterized in that it is obtained by photocuring and then thermally curing the following coating, wherein the coating is: a coating obtained by applying the photosensitive thermosetting developing resin composition on a substrate and drying; or a coating obtained by applying the photosensitive thermosetting developing resin composition on a carrier film and drying, and pressing the obtained photocurable dry film layer on the substrate.

The greatest technical feature of the photosensitive thermosetting developing resin composition of the present invention is that it comprises (A) a vinyl ester resin, (B) a photopolymerization initiator, (C) a phosphate ester dispersant, (D) a compound having two or more ethylenically unsaturated groups in one molecule, and (E) an inorganic filler, wherein the (C) phosphate ester dispersant comprises a polymer having a phosphate ester structure in the main chain (C-1), and the (E) inorganic filler comprises talc and silica.

Based on the characteristic structure of the present invention, by using a polymer with a phosphate structure in the main chain, and combining talc and silicon dioxide, and optimizing the ratio of the two to replace the traditional filler barium sulfate, the printing property and pencil hardness can be improved on the basis of effectively improving the resistance to cold and hot shocks.

In contrast, using talc and barium sulfate as fillers at the same time can meet the requirements of the solder resist ink for resistance to cold and hot shocks, but the pencil hardness will be poor (for example, Patent Document 1, etc.).

As mentioned above, the inventors of the present invention have found through repeated and in-depth research that talc has better flexibility as a filler and has excellent crack resistance in the temperature cycle test (hereinafter sometimes referred to as the "TCT test"), but the surface hardness decreases significantly. In addition, talc has a large oil absorption, which seriously deteriorates the printing properties of ink. Silica has a higher hardness and a lower oil absorption. By using talc and silica at the same time and optimizing the ratio of the two, the above-mentioned purpose of the present invention is achieved. [Effect of the invention]

As described above, the present invention can provide a photosensitive thermosetting developing resin composition having excellent printability and capable of forming a solder resist layer having excellent hardness and resistance to cold and hot shocks, a dry film thereof, a cured product thereof, and a printed circuit board.

Hereinafter, each component of the photosensitive thermosetting developing resin composition of the present invention will be described.

The photosensitive thermosetting developing resin composition of the present invention is characterized by containing (E) an inorganic filler, wherein the (E) inorganic filler includes talc and silica as essential components, and therefore the (E) inorganic filler will be described first.

(E) Inorganic filler In the photosensitive thermosetting developing resin composition of the present invention, talc used as (E) inorganic filler is used to improve resistance to cold and hot shocks. Silica is used to improve printability.

As talc, the parent rock can be any one of magnesium carbonate, serpentine, silica/silica-alumina, and magnesium precipitate, and can be one of the so-called silicate minerals, and the shape can be blocky or fine powder. It may or may not be surface treated. The oil absorption of talc is suitable for 20~100ml/100g, preferably 30~90ml/100g, and more preferably 40~80ml/100g. The average particle size of talc is suitable for 1.0-20.0μm, more preferably 2.0~10μm, and further preferably 3.0~8.0μm.

As commercially available products, HD25 manufactured by Shandong Pingdu Talc Mining Co., Ltd. and LMP-100 manufactured by Fuji Talc Industry Co., Ltd. can be cited.

The silicon dioxide may be any of amorphous and crystalline, or a mixture thereof. Amorphous (fused) silicon dioxide is particularly preferred. Surface treatment may or may not be performed. The silicon dioxide oil absorption is suitably 15 to 60 ml/100 g, preferably 20 to 50 ml/100 g, and more preferably 27 to 45 ml/100 g. The average particle size of the silicon dioxide is suitably 0.1 to 10.0 μm, more preferably 1.0 to 8.0 μm, and further preferably 2.0 to 6.0 μm.

Commercially available products of silicon dioxide include CS1002 and CS1002A manufactured by Jiangsu Lianrui New Materials Co., Ltd., A-8 manufactured by Sibelco Co., Ltd. , SE-40 manufactured by Tokuyama Co., Ltd., MSV25G manufactured by Ronsen, MLV-2114 manufactured by Ronsen, SO-E5 manufactured by ADMATECHS, and SO-E2 manufactured by ADMATECHS.

Regarding the mixing ratio of talc and silica, based on the total weight of the two as 100 weight%, the lower limit of the talc ratio is preferably 20 weight% or more, preferably 25 weight% or more, and more preferably 30 weight% or more. The upper limit of the talc ratio is preferably 80 weight% or less, preferably 75 weight% or less, and more preferably 70 weight% or less. When the talc ratio is within the above range, the resistance to cold and hot shocks can be significantly improved. When it is less than 20 weight%, sufficient resistance to cold and hot shocks cannot be obtained. When it exceeds 80 weight%, although the resistance to cold and hot shocks is still excellent, the printability and the surface hardness of the solder mask tend to decrease. It is speculated that this is because the oil absorption of talc is large, and when its amount is too much, the printability of the ink is greatly affected. Silica has a higher hardness and a lower oil absorption. By mixing the two in a suitable ratio, it is possible to achieve both printability and pencil hardness (at least 4H, preferably 6H or above) while improving resistance to cold and hot shock (withstanding at least 1,000 cycles under cold and hot cycling conditions of -40°C to 160°C).

In addition, the total amount of talc and silica is preferably 50 to 180 parts by weight, preferably 60 to 160 parts by weight, and more preferably 80 to 150 parts by weight, relative to 100 parts by weight of the (A) vinyl ester resin in terms of solid content. Within the above range, excellent resistance to cold and hot shocks can be achieved while taking into account both printability and hardness.

In order to further satisfy the requirements of resistance to cold and hot impact, pencil hardness and printability, the photosensitive thermosetting developing resin composition of the present invention preferably does not contain barium sulfate.

(A) Vinyl ester resin The (A) vinyl ester resin in the photocurable thermosetting resin composition of the present invention can use a known resin containing an olefinic unsaturated double bond in the molecule for imparting alkaline development. From the aspects of photocurability and development resistance, a carboxyl-containing resin having an olefinic unsaturated double bond in the molecule is particularly preferred. In addition, it is more preferred that the unsaturated double bond is derived from acrylic acid or methacrylic acid or a derivative thereof. As the (A) vinyl ester resin, a resin using an epoxy resin as a starting material, a polyurethane resin having a urethane skeleton, a copolymer resin having a copolymer structure of an unsaturated carboxylic acid, and a resin using a phenol compound as a starting material are preferred. Specific examples of the (A) vinyl ester resin are shown below.

(1) Vinyl ester resins obtained by copolymerizing unsaturated carboxylic acids such as (meth)acrylic acid with one or more other compounds having unsaturated double bonds;

(2) Photosensitive vinyl ester resins obtained by adding an olefinic unsaturated group as a pendant to a copolymer of an unsaturated carboxylic acid such as (meth)acrylic acid and one or more other compounds having an unsaturated double bond, using compounds having an epoxy group and an unsaturated double bond such as glycidyl (meth)acrylate, 3,4-epoxyhexylmethyl (meth)acrylate, (meth)acrylic acid chloride, etc.;

(3) A photosensitive vinyl ester resin obtained by reacting a copolymer of a compound having an epoxy group and an unsaturated double bond such as glycidyl (meth)acrylate and 3,4-epoxyhexylmethyl (meth)acrylate, and another compound having an unsaturated double bond with an unsaturated carboxylic acid such as (meth)acrylic acid, and reacting a polyacid anhydride with the generated second hydroxyl group;

(4) Photosensitive vinyl ester resins obtained by reacting a copolymer of an acid anhydride having an unsaturated double bond such as maleic anhydride and another compound having an unsaturated double bond with a compound having a hydroxyl group and an unsaturated double bond such as 2-hydroxyethyl (meth)acrylate;

(5) Vinyl ester resins obtained by reacting a polyfunctional epoxy compound with an unsaturated monocarboxylic acid and reacting a saturated or unsaturated polyacid anhydride with the resulting hydroxyl group;

(6) A vinyl ester resin containing hydroxyl and carboxyl groups obtained by reacting a hydroxyl-containing polymer such as a polyvinyl alcohol derivative with a saturated or unsaturated polyacid anhydride and then reacting a compound having an epoxy group and an unsaturated double bond in one molecule with the resulting carboxylic acid;

(7) A vinyl ester resin obtained by reacting a reaction product of a polyfunctional epoxy compound and an unsaturated monocarboxylic acid with a compound having at least one alcoholic hydroxyl group and one reactive group other than the alcoholic hydroxyl group that reacts with the epoxy group in one molecule, with a saturated or unsaturated polybasic acid anhydride;

(8) a vinyl ester resin obtained by reacting an unsaturated monocarboxylic acid with a polyfunctional cyclohexane compound having at least two cyclohexane rings in one molecule, and reacting a saturated or unsaturated polyacid anhydride with a primary hydroxyl group in the obtained modified cyclohexane resin; and

(9) A vinyl ester resin obtained by reacting an unsaturated monocarboxylic acid with a polyfunctional epoxy resin and then reacting the resulting reaction with a polyacid anhydride, and further reacting the resulting reaction with a compound having one cyclohexane ring and one or more olefinic unsaturated groups in the molecule;

(10) A vinyl ester resin obtained by reacting a difunctional epoxy compound with an unsaturated monocarboxylic acid and reacting a saturated or unsaturated polyacid anhydride with the resulting hydroxyl group.

Particularly preferred among these examples are the vinyl ester resins (2), (5), (7) and (9).

It should be noted that, in this specification, (meth)acrylate is a term that collectively refers to acrylate, methacrylate and mixtures thereof, and the same applies to other similar expressions.

Since the above-mentioned (A) vinyl ester resin has a plurality of free carboxyl groups on the side chains of the main chain polymer, it can be developed using a dilute alkaline aqueous solution.

The acid value of the vinyl ester resin (A) is preferably in the range of 40 to 200 mgKOH/g, more preferably in the range of 45 to 120 mgKOH/g. If the acid value of the carboxyl-containing resin is less than 40 mgKOH/g, alkali development is difficult. On the other hand, if it exceeds 200 mgKOH/g, the developer dissolves the exposed part, so that the line becomes thinner than necessary, and sometimes the exposed part and the unexposed part are dissolved and peeled by the developer without distinction, making it difficult to draw a normal resist pattern, so it is not preferred.

The weight average molecular weight of the vinyl ester resin (A) varies depending on the resin skeleton, but is generally preferably in the range of 2,000 to 150,000, and more preferably in the range of 5,000 to 100,000. When the weight average molecular weight is less than 2,000, the coating on the substrate and the non-tackiness after drying may be poor, and the moisture resistance of the coating after exposure may deteriorate, and film reduction may occur during development, and the resolution may be greatly deteriorated. On the other hand, when the weight average molecular weight exceeds 150,000, the developability may be significantly deteriorated and the storage stability may be poor.

The blending amount of the vinyl ester resin (A) is preferably in the range of 20 to 60% by mass of the total composition based on the solid content, preferably 25 to 50% by mass. If the blending amount of the vinyl ester resin (A) is less than the above range, the coating film strength is reduced, which is not preferred. On the other hand, if the blending amount is more than the above range, the viscosity of the composition becomes high or the coating property is reduced, which is not preferred.

(B) Photopolymerization initiator The photopolymerization initiator used in the photosensitive thermosetting developing resin composition of the present invention is not particularly limited as long as it is a photopolymerization initiator commonly used in photosensitive thermosetting developing resin compositions.

As the photopolymerization initiator, known substances can be used, and examples thereof include: benzoin and its alkyl ethers such as benzoin, benzoin methyl ether, and benzoin ethyl ether; acetophenones such as acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, and 4-(1-tert-butyldioxy-1-methylethyl)acetophenone; 2-methylanthraquinone, 2-amylanthraquinone, 2-tert-butylanthraquinone, and 1-chloroanthraquinone. Anthraquinones; thiocontanes such as isopropylthiocontanone, 2,4-dimethylthiocontanone, 2,4-diisopropylthiocontanone, and 2-chlorothiocontanone; ketones such as acetophenone dimethyl ketal and benzyl dimethyl ketal; benzophenones such as benzophenone, 4-(1-tert-butyldioxy-1-methylethyl)benzophenone, and 3,3',4,4'-tetrakis(tert-butyldioxycarbonyl)benzophenone; and oxanthrone, etc.

In addition, as the photopolymerization initiator, an oxime ester-based photopolymerization initiator having an oxime ester group, an alkylphenone-based photopolymerization initiator, an α-aminoacetophenone-based photopolymerization initiator, an acylphosphine oxide-based photopolymerization initiator, a titanocene-based photopolymerization initiator, or the like can also be used.

Commercially available oxime ester photopolymerization initiators include Irgacure OXE01 and Irgacure OXE02 manufactured by BASF Japan, and N-1919 and NCI-831 manufactured by ADEKA CORPORATION. A photopolymerization initiator having two oxime ester groups in the molecule can be preferably used, and specifically, an oxime ester compound having an oxazole ring structure can be exemplified.

Commercially available products of alkylphenone-based photopolymerization initiators include α-hydroxyalkylphenone-based products such as Omnirad 184, Omnirad 1173, Omnirad 2959, and Omnirad 127 manufactured by IGM Resins B.V.

Specific examples of the α-aminoacetophenone-based photopolymerization initiator include 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propanone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholino)phenyl]-1-butanone, and N,N-dimethylaminoacetophenone. As commercially available products, Omnirad 907, Omnirad 369, and Omnirad 379 manufactured by IGM Resins B.V. can be used.

As the acylphosphine oxide-based photopolymerization initiator, specifically, there can be mentioned 2,4,6-trimethylbenzyldiphenylphosphine oxide, bis(2,4,6-trimethylbenzyl)-phenylphosphine oxide, bis(2,6-dimethoxybenzyl)-2,4,4-trimethyl-pentylphosphine oxide, trifunctional or higher acylphosphine-based photopolymerization initiators, etc. The trifunctional or higher acylphosphine-based photopolymerization initiator may be a photopolymerization initiator having three or more acylphosphine oxide skeletons in one molecule, and may be represented by the following formula (I).

wherein A independently represents a single bond, O, S or NR ³ ; G is a residue of a multifunctional compound (core) G-(AH) _m+n , wherein AH independently represents an alcohol group, an amine group or a thiol group; m and n are both integers, and m+n is an integer between 3 and 10; m is an integer between 3 and 8; R ₁ and R ₂ independently represent a C ₁ -C 18 alkyl group, a C ₆ -C 12 aryl group and a C 5 -C 12 cycloalkyl group, each of which is continuous or interrupted by the following groups: one or more oxygen and/or sulfur atoms and/or one or more substituted or unsubstituted imino groups, or R 1 and R 2 are each independently a C 1 -C ₁₈ alkyl group, a C 6 -C ₁₂ aryl group and a C ₅ -C ₁₂ cycloalkyl group, each of which is continuous or interrupted by the following groups: one or more oxygen and/or sulfur atoms and/or one or more substituted or unsubstituted imino groups, or R ₁ and R ₂ are independently a five- to six-membered heterocyclic group containing oxygen and/or nitrogen and/or sulfur atoms, wherein the aforementioned groups are each optionally substituted by an aryl group, an alkyl group, an aryloxy group, an alkoxy group, a heteroatom and/or a heterocyclic group; R ₂ may be R ₁ -(C=O)-; Y is O or S; R ₃ is hydrogen or a C ₁ to C ₄ alkyl group;

The photopolymerization initiator of formula (I) does not contain a photocurable ethylenic unsaturated group.

Preferably, in formula (I), m+n is an integer between 3 and 8, more preferably an integer between 3 and 6. For example, in formula I, m is an integer between 3 and 6, more preferably an integer between 3 and 5.

In formula (I), when A is oxygen, G-(AH) _m+n is a polyhydroxyl (polyhydroxyl) compound selected from the group consisting of monomer polyols, oligomer polyols and polymer polyols and mixtures thereof. When A is sulfur, G-(AH) _m+n is a polythiol compound. In formula (I), when A is nitrogen, G-(AH) _m+n is a linear or branched polyamine. When A is a mixture of oxygen and/or nitrogen and/or sulfur, G-(AH) _m+n is a compound containing different functional groups, for example, a compound containing an amino group and a hydroxyl group. The residue G- suitable for the implementation of the present invention does not contain a photocurable ethylenic unsaturated group. When A is a single bond, G- is the residue after removing the hydroxyl and/or amino group and/or hydroxyl group from the above-mentioned G-(AH) _m+n .

It is preferred that G-(AH) _m+n has a number average molecular weight of 1500 or less, more preferably 800 or less, further preferably 500 or less.

When n is not 0, the compound of formula (I) has an alcoholic free group and/or an amino group and/or a hydroxyl group.

Representative trifunctional or higher acylphosphine photopolymerization initiators included in formula (I) are shown in Table 1. Among these, PI-3, PI-4, PI-10, PI-11, PI-12, PI-14, and PI-17 are particularly preferred. By including such trifunctional or higher acylphosphine photopolymerization initiators, outgassing is suppressed and a cured product with more excellent insulation reliability can be obtained.

Table 1

Such a trifunctional or higher acylphosphine-based photopolymerization initiator can be produced by the method described in Japanese Patent No. 6599446, for example.

As commercially available products of acylphosphine oxide-based photopolymerization initiators, Omnirad TPO manufactured by IGM Resins, Omnirad 819 and Omnipol TP manufactured by IGM Resins B.V., etc. can be used.

Specific examples of the titanocene-based photopolymerization initiator include bis(cyclopentadienyl)-diphenyl titanium, bis(cyclopentadienyl)-titanium dichloride, bis(cyclopentadienyl)-bis(2,3,4,5,6-pentafluorophenyl)titanium, and bis(cyclopentadienyl)-bis(2,6-difluoro-3-(pyrrol-1-yl)phenyl)titanium. Examples of commercially available products include Omnirad 784 manufactured by IGM Resins B.V.

The compounding ratio of the photopolymerization initiator (B) is preferably 0.01 to 30 parts by weight, preferably 5 to 25 parts by weight, and more preferably 10 to 20 parts by weight, relative to 100 parts by weight of the vinyl ester resin (A) in terms of solid content. If the amount of the photopolymerization initiator used is less than the above range, the photocurability of the composition deteriorates, while if it is too much, the properties as a solder resist are deteriorated, which is not preferred.

(C) Phosphate Ester Dispersant The (C) phosphate ester dispersant used in the photosensitive thermosetting developing resin composition of the present invention refers to a compound or polymer having a phosphate structure represented by the following formula (II) in the main chain or the side chain.

Among them, based on the perspective of having good affinity with pigments, being usable in solvent-free and solvent-based inks, and being suitable for stabilizing pigments in low-polarity systems (such as alkyd resins, acrylate resins, thermoplastic acrylic resins and epoxy resins), polymers having a phosphate structure as shown in formula (II) in the main chain or side chain are preferred.

Furthermore, the inventors have found that, from the perspective of improving the resistance to cold and hot shocks while taking into account both the ink printability and the surface hardness of the solder mask layer, it is more preferable to use a polymer having a phosphate structure in the main chain (i.e., a polyphosphate polymer) and a polymer having a phosphate structure in the side chain as the (C) phosphate ester dispersant while combining talc with silica as a filler. At this time, the mixing ratio of the two is based on a weight ratio, i.e., (C-1) a polymer having a phosphate structure in the main chain: (C-2) a polymer having a phosphate structure in the side chain of 1:10 to 10:1, preferably 1:5 to 5:1, more preferably 1:3 to 3:1, and further preferably 1:2 to 2:1. In this way, a photosensitive thermosetting developing resin composition having excellent ink printability, solder mask surface hardness, and resistance to cold and hot shock can be obtained.

The compounding ratio of (C) phosphate ester dispersant is suitably 0.01 to 20 parts by weight, preferably 0.1 to 15 parts by weight, and more preferably 1 to 10 parts by weight, relative to 100 parts by weight of the (A) vinyl ester resin in terms of solid content. The amount of (C) phosphate ester dispersant used within the above range can ensure excellent resistance to thermal shock while taking into account both printability and hardness. If the amount exceeds the above range, the properties as a solder resist are reduced, which is not preferred.

Commercially available products of phosphate ester dispersants include Tech-5011 (manufactured by Shanghai Tiger Polymer Technology Co., Ltd.), BYK-102, BYK-103, BYK-106, BYK-110, BYK-111, BYK-118, BYK-142, BYK-145 (manufactured by Beck Chemical Co., Ltd.), etc.

It should be noted that in this specification, polymer is a term generally referring to homopolymers, copolymers and mixtures thereof, and the same applies to other similar expressions.

(D) Compounds having two or more ethylenically unsaturated groups in one molecule The compound (D) having two or more ethylenically unsaturated groups in one molecule used in the photosensitive thermosetting developing resin composition of the present invention is a compound that makes the aforementioned (A) vinyl ester resin insoluble in an alkaline aqueous solution by photocuring with active energy rays, or helps the aforementioned vinyl ester resin to be insoluble in an alkaline aqueous solution. Specific examples of such compounds include: Hydroxyl alkyl acrylates such as 2-hydroxyethyl acrylate and 2-hydroxypropyl acrylate; Monoacrylates or diacrylates of glycols such as ethylene glycol, methoxytetraethylene glycol, polyethylene glycol, and propylene glycol; Acrylamides such as N,N-dimethylacrylamide, N-hydroxymethylacrylamide, and N,N-dimethylaminopropylacrylamide; Aminoalkyl acrylates such as N,N-dimethylaminoethyl acrylate and N,N-dimethylaminopropyl acrylate; Polyacrylates of polyols such as hexanediol, trihydroxymethylpropane, pentaerythritol, dipentaerythritol, and trihydroxyethyl isocyanurate, or their ethylene oxide adducts or propylene oxide adducts; Acrylates such as phenoxy acrylate, bisphenol A diacrylate, and ethylene oxide adducts or propylene oxide adducts of these phenols; Acrylates of glycidyl ethers such as glycerol diglycidyl ether, glycerol triglycidyl ether, trihydroxymethylpropane triglycidyl ether, and triglycidyl isocyanurate; and melamine acrylate, and at least one of the methacrylates corresponding to the above acrylates, etc. Furthermore, examples include: epoxy acrylate resins formed by reacting a multifunctional epoxy resin such as a cresol novolac epoxy resin with acrylic acid, and epoxy urethane acrylate compounds formed by reacting the hydroxyl group of the epoxy acrylate resin with a hydroxyl acrylate such as pentaerythritol triacrylate and a half urethane compound of a diisocyanate such as isophorone diisocyanate, etc.

The compound (D) having two or more ethylenically unsaturated groups in one molecule is preferably added in an amount of 5 to 100 parts by weight, more preferably 10 to 70 parts by weight, relative to 100 parts by weight of the aforementioned (A) vinyl ester resin in terms of solid content. If the amount is less than 5 parts by weight relative to 100 parts by weight of the aforementioned (A) vinyl ester resin, the photocurability of the resulting photosensitive thermosetting developing resin composition is reduced, and it is difficult to form a pattern by alkaline development after irradiation with active energy rays, which is not preferred. On the other hand, if the amount exceeds 100 parts by weight, the solubility in alkaline aqueous solutions is reduced, and the cured coating becomes brittle, which is not preferred.

(F) Other additives As mentioned above, the other additives in the present invention refer to additives other than (B) photopolymerization initiator and (C) phosphate dispersant.

Examples of such additives include: phthalocyanine blue, phthalocyanine green, iodine green, disazo yellow, crystal violet, titanium oxide, carbon black, naphthalene black and other commonly used coloring agents; hydroquinone, hydroquinone monomethyl ether, tert-butylcatechol, pyrogallol, phenothiazine and other commonly used thermal polymerization inhibitors; micronized silica, organic bentonite, montmorillonite and other commonly used Well-known and commonly used additives such as descaling thickeners, at least one of organic silicon-based, fluorine-based, polymer-based defoaming agents and leveling agents, imidazole-based, thiazole-based, triazole-based adhesion agents, silane coupling agents, phenol-based, phosphorus-based, sulfur-based antioxidants, hindered amine-based light stabilizers, etc.

The compounding ratio of such (F) other additives is preferably 0.01 wt % or more and 20 wt % or less of the total amount of the photosensitive thermosetting developing resin composition. If it is less than 0.01 wt %, the corresponding effect cannot be fully obtained, and if it exceeds 20 wt %, the printing property and hardness of the photosensitive thermosetting developing resin composition deteriorate, which is not preferred.

(G) Epoxy resin In order to impart heat resistance, the photosensitive thermosetting developing resin composition used in the present invention preferably contains an epoxy resin having at least two epoxy groups in the molecule, i.e., a multifunctional epoxy resin (G).

Examples of commercially available products include jER828, jER834, jER1001, and jER1004 manufactured by Mitsubishi Chemical Corporation, EPICLON 840, 850, 850S, 1050, and 2055 manufactured by DIC Corporation, EPOTOTE YD-011, YD-013, YD-127, and YD-128 manufactured by NIPPON STEEL Chemical & Material Co., Ltd., D.E.R.317, D.E.R.331, D.E.R.661, and D.E.R.664 manufactured by Dow Chemical Company, and Sumi-Epoxy manufactured by Sumitomo Chemical Industries, Ltd. ESA-011, ESA-014, ELA-115, ELA-128, etc. (all trade names) bisphenol A type epoxy resins; jERYL903 manufactured by Mitsubishi Chemical Corporation, EPICLON 152, EPICLON 165 manufactured by DIC Corporation, EPOTOTE YDB-400, YDB-500 manufactured by NIPPON STEEL Chemical & Material Co., Ltd., D.E.R.542 manufactured by Dow Chemical Company, Sumi-Epoxy ESB-400, ESB-700, etc. (all trade names) brominated epoxy resins; jER152, jER154 manufactured by Mitsubishi Chemical Corporation, D.E.N.431, D.E.N.438 manufactured by Dow Chemical Company, EPICLON N-730, EPICLON N-770, EPICLON N-865, EPOTOTE YDCN-701, YDCN-704 manufactured by NIPPON STEEL Chemical & Material Co., Ltd., EPPN-201, EOCN-1025, EOCN-1020, EOCN-104S, RE-306, NC-3000 manufactured by Nippon Kayaku Co., Ltd., Sumi-Epoxy ESCN-195X, ESCN-220 manufactured by Sumitomo Chemical Industries, Ltd., YDCN-700-2, YDCN-700-3, YDCN-700-5, YDCN-700-7, YDCN-700-10, YDCN-704, YDCN-704A manufactured by NIPPON STEEL Chemical & Material Co., Ltd., EPICLON Novolac epoxy resins such as N-680, N-690, and N-695 (all trade names); bisphenol F epoxy resins such as EPICLON 830 manufactured by DIC Corporation, jER807 manufactured by Mitsubishi Chemical Corporation, and EPOTOTE YDF-170, YDF-175, and YDF-2004 manufactured by NIPPON STEEL Chemical & Material Co., Ltd. (all trade names); hydrogenated bisphenol A epoxy resins such as EPOTOTE ST-2004, ST-2007, and ST-3000 (trade names) manufactured by NIPPON STEEL Chemical & Material Co., Ltd., and YX8034 manufactured by Mitsubishi Chemical Corporation; jER604 manufactured by Mitsubishi Chemical Corporation, and EPOTOTE YH-434, Sumi-Epoxy ELM-120, etc. (all trade names) manufactured by Sumitomo Chemical Industries, Ltd. Glycidylamine type epoxy resins; hydantoin type epoxy resins; CELLOXIDE 2021P, etc. (trade names) manufactured by Daicel Corporation; YL-933 manufactured by Mitsubishi Chemical Corporation, EPPN-501, EPPN-502, etc. (all trade names) manufactured by Nippon Kayaku Co., Ltd. Trihydroxyphenylmethane type epoxy resins; YL-6056, YX-4000, YL-6121 (all trade names) manufactured by Mitsubishi Chemical Corporation Bixylenol type or biphenol type epoxy resins or mixtures thereof; EBPS-200, ADEKA manufactured by Nippon Kayaku Co., Ltd. EPX-30 manufactured by KOMOBILE CORPORATION, EXA-1514 (trade name) manufactured by DIC Corporation, etc. bisphenol S type epoxy resins; jER157S (trade name) manufactured by Mitsubishi Chemical Corporation, etc. bisphenol A novolac type epoxy resins; jERYL-931 (trade name) manufactured by Mitsubishi Chemical Corporation, etc. tetrahydroxyphenylethane type epoxy resins; TEPIC (trade name) manufactured by Nissan Chemical Industries, Ltd., etc. hybrid epoxy resins; BRENMAR DGT (trade name) manufactured by NOF Corporation, etc. diglycidyl phthalate resins; ZX-1063 (trade name) manufactured by NIPPON STEEL Chemical & Material Co., Ltd., etc. tetraglycidyl dimethylbenzene ether resins; NIPPON STEEL Chemical & Material Co., Ltd., etc. Ltd., ESN-190, ESN-360, HP-4032, EXA-4750, EXA-4700, etc., made by DIC Corporation; methacrylate glycidyl copolymer epoxy resins such as CP-50S, CP-50M, etc. made by NOF Corporation; furthermore, copolymer epoxy resins of cyclohexylmaleimide and methacrylate glycidyl; CTBN modified epoxy resins (such as YR-102, YR-450, etc. made by NIPPON STEEL Chemical & Material Co., Ltd.), etc., but not limited to these. These epoxy resins can be used alone or in combination of two or more.

The content of the (G) epoxy resin is preferably 10 to 100 parts by weight, more preferably 20 to 90 parts by weight, and more preferably 30 to 80 parts by weight, based on 100 parts by weight of the (A) vinyl ester resin in terms of solid content.

(H) Organic solvent The organic solvent (H) that can be used in the photosensitive thermosetting developing resin composition of the present invention can be used to synthesize the aforementioned carboxyl-containing resin (A), prepare the composition, or adjust the viscosity for coating on a substrate or a carrier film.

Examples of such organic solvents include ketones, aromatic hydrocarbons, glycol ethers, glycol ether acetates, esters, alcohols, aliphatic hydrocarbons, and petroleum-based solvents. More specifically, ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; glycol ethers such as solvent, methyl solvent, butyl solvent, carbitol, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether, and triethylene glycol monoethyl ether; esters such as ethyl acetate, butyl acetate, dipropylene glycol methyl ether acetate, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, and propylene glycol butyl ether acetate; alcohols such as ethanol, propanol, ethylene glycol, and propylene glycol; aliphatic hydrocarbons such as octane and decane; petroleum solvents such as petroleum ether, naphtha, hydrogenated naphtha, and solvent naphtha, etc. The above organic solvents can be used alone or in the form of a mixture of two or more.

When the photosensitive thermosetting developing resin composition of the present invention is used to form a solder resist for a printed circuit board, the composition is adjusted to a viscosity suitable for the coating method as needed, and then coated on, for example, a printed circuit board on which a circuit is pre-formed by a method such as screen printing, curtain printing, spray coating, or roller coating. If necessary, a non-sticky coating film can be formed by drying the composition at a temperature of about 60 to 100°C. Then, by selectively exposing with active light through a photomask having a prescribed exposure pattern, and developing the unexposed portion with an alkaline aqueous solution, an anti-corrosion pattern can be formed. Furthermore, by, for example, heating to a temperature of about 140 to 180° C. to thermally cure the film, the curing reaction of the epoxy resin and the polymerization of the vinyl ester resin can be promoted, thereby improving the hardness, thermal shock resistance, heat resistance, solvent resistance, acid resistance, moisture absorption resistance, PCT tolerance, adhesion, electrical properties, and other properties of the resulting anti-corrosion coating.

As the alkaline aqueous solution used in the above-mentioned development, there can be used alkaline aqueous solutions of potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate, ammonia, amines, etc. In addition, as the irradiation light source for photocuring, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a semiconductor laser, a solid laser, a xenon lamp, or a metal halide lamp is suitable.

In addition to the method of directly applying the photosensitive thermosetting developing resin composition of the present invention to a substrate in a liquid state, the photosensitive thermosetting developing resin composition can also be used in the form of a photocurable dry film obtained by applying the photosensitive thermosetting developing resin composition on a carrier film in advance and drying it. The following shows the case where the photosensitive thermosetting developing resin composition of the present invention is used in the form of a photocurable dry film.

The photocurable dry film has a structure in which a carrier film, a resin layer, and a peelable cover film used as needed are stacked in sequence. The resin layer is a layer obtained by applying the photosensitive thermosetting developing resin composition of the present invention on a carrier film or a cover film and drying it. After forming a resin layer on a carrier film, a cover film is stacked thereon, or a resin layer is formed on a cover film and the stacked body is stacked on a carrier film to obtain a dry film.

As the carrier film, a thermoplastic film such as a polyester film having a thickness of 2 to 150 μm can be used. The resin layer is formed by uniformly applying a photosensitive thermosetting developing resin composition to a carrier film or a covering film at a thickness of 10 to 150 μm using a doctor blade coater, a lip coater, a comma coater, a film coater, etc. and drying. As the covering film, a polyethylene film, a polypropylene film, etc. can be used. A covering film having a smaller adhesive force to the resin layer than the carrier film and the resin layer is preferred.

The cured product of the present application is obtained by photocuring the following coating, wherein the coating is: a coating obtained by applying a photosensitive thermosetting developing resin composition on copper and drying it; or a coating obtained by applying the photosensitive thermosetting developing resin composition on a carrier film and drying it, and pressing the obtained photocurable dry film layer on copper.

When a photocurable dry film is used to produce a cured product on a printed circuit board having a copper circuit, the cover film is peeled off, and the resin layer is overlapped with the substrate having the circuit formed thereon, and the resin layer is formed on the substrate having the circuit formed thereon by laminating them using a laminating press or the like. When the formed resin layer is exposed, developed, and heat-cured in the same manner as described above, a cured product can be formed. The carrier film can be peeled off before or after exposure.

The photosensitive thermosetting developing resin composition is suitable for forming a hardened film on a printed circuit board. As the hardened film, a permanent insulating film is preferred, and a solder resist layer is particularly preferred.

Examples The present invention is described in more detail based on the examples and comparative examples, but the scope of protection of the present invention and its implementation are not limited to these. "Parts" or "%" in the examples and comparative examples are based on weight unless otherwise specified. The property value test of the composition of this example was carried out by the method described below.

Synthesis Example 214 parts of cresol novolac epoxy resin EPICLON N-695 (manufactured by DIC, epoxide equivalent = 214) were added to a four-necked flask equipped with a stirrer and a reflux condenser, and 103 parts of carbitol acetate and 103 parts of petroleum-based hydrocarbon solvent (manufactured by Japan Energy Corporation, trade name: Cactus Fines SF-01) were added and heated to dissolve. Next, 0.1 parts of hydroquinone as a polymerization inhibitor and 2.0 parts of triphenylphosphine as a reaction catalyst were added. The mixture was heated to 95-105°C, 72 parts of acrylic acid were slowly added dropwise, and the mixture was reacted for 16 hours. The obtained reaction product was cooled to 80-90°C, 91.2 parts of tetrahydrophthalic anhydride were added, the mixture was reacted for 8 hours, and the mixture was taken out after cooling. The carboxyl vinyl ester resin obtained in this way has a non-volatile content of 65% and an acid value of 87.5 mgKOH/g in solid components.

The vinyl ester resin solution (varnish) of the above-mentioned synthesis example was mixed with the various components and proportions (weight parts) shown in Table 1, pre-mixed with a stirrer, and then kneaded with a 3-roll mill to prepare a photosensitive thermosetting developing resin composition. The printability, pencil hardness, and resistance to cold and hot shock were evaluated according to the following methods.

A    Cresol novolac type epoxy modified acrylic resin (solid content 65%) prepared in the following synthesis example F    Pigment: Phthalocyanine Green, Pigment A manufactured by DIC Corporation Defoamer: KS-66 manufactured by Shin-Etsu Chemical Co., Ltd. C-1 Phosphate ester dispersant: BYK-110, polyphosphate, polyphosphate polymer, manufactured by Beck Chemical Co., Ltd., solid content 52% by mass, oil absorption 63ml/100g C-2 Phosphate ester dispersant: BYK-142, a compound of the reaction product of 2-ethylhexyl acrylate and (polymer of ethylenediamine and ethyleneimine) and polyethylene polypropylene glycol monobutyl ether phosphate), manufactured by Beck Chemical Co., Ltd., solid content 60% by mass, oil absorption 29ml/100g B   Photopolymerization initiator: Omnirad 369 E, manufactured by IGM E    Talc: LMP-100, manufactured by FUJI TALC INDUSTRIAL Silica: A-8 manufactured by Sibelco Barium sulfate: B-30, manufactured by Sakai Chemical Industry Co., Ltd. H    Solvent: PGMEA, propylene glycol monomethyl ether acetate CC G    Epoxy resin: N-770-75EA, manufactured by DIC, a phenolic varnish type multifunctional epoxy resin, solid content 75 mass% D    Compounds having two or more ethylenically unsaturated groups in one molecule: MT-3501G, manufactured by Zhangjiagang Dongya Di Ai Biochemical Co., Ltd.

Performance evaluation: (1) Printability The photosensitive thermosetting developing resin composition of the embodiment and the comparative example was applied to the entire surface of a substrate with a φ400μm opening pattern with a copper thickness of 100μm and a pitch of 600μm by screen printing. After standing at room temperature for 30 minutes, it was dried in a hot air circulation drying furnace at 80°C for 30 minutes to prepare a printability evaluation substrate. The printability evaluation substrate was observed using a 100x optical microscope, and the bubble occurrence rate of the copper opening was evaluated (see Figure 1). The evaluation criteria are as follows. 0: Bubble occurrence rate less than 40% △: Bubble occurrence rate of more than 40% and less than 50% ×: Bubble occurrence rate of more than 50%

(2) Pencil hardness The photosensitive thermosetting developing resin composition of the above-mentioned embodiment and comparative example was applied to the entire surface of a copper foil laminate substrate that had been pre-treated by polishing and grinding by screen printing, dried at 80°C for 30 minutes, and cooled to room temperature to form a resin layer with a thickness of 40 μm. The resin layer was pattern-exposed at 400 mJ/ ^cm2 using an exposure device equipped with a high-pressure mercury lamp, and developed for 50 seconds using a 1 mass % sodium carbonate aqueous solution at 30°C and a spray pressure of 0.15 MPa. The pencil hardness of the resin surface of the obtained resin coating after thermal curing was measured in accordance with JIS K 5600-5-4. The evaluation criteria are as follows: ○: Pencil hardness 6H or higher △: Pencil hardness 4H or higher and lower than 6H ×: Pencil hardness lower than 4H

(3) Resistance to thermal shock The photosensitive thermosetting developing resin composition of the embodiment and the comparative example was applied to the entire surface of a substrate having a 2 mm copper wire pattern formed thereon by screen printing so as to have a thickness of 40 μm, and dried in a hot air circulation drying oven at 80°C for 30 minutes. After cooling to room temperature, the pattern was exposed at 400 mJ/ ^cm2 using an exposure device equipped with a high-pressure mercury lamp, and then developed in a 1 wt% sodium carbonate aqueous solution, a pressure of 0.2 MPa, and a liquid temperature of 30°C for 60 seconds, and then cured in a hot air circulation drying oven at 150°C for 60 minutes. By irradiating ultraviolet rays in a UV conveyor furnace with a cumulative exposure of 2000mJ/ ^cm2 , 17 hot and cold cycle crack resistance evaluation substrates with rectangular anti-etching patterns were produced. A number of evaluation substrates produced as above were placed in a hot and cold cycler that cycles the temperature between -40°C and 160°C and set different cycles to conduct a hot and cold shock cycle test (TCT test). Then, the appearance at each cycle number was observed, and the maximum cycle number without cracks was recorded. The evaluation criteria are as follows (see Figures 2 and 3 for schematic diagrams of cracks and non-cracks). ○: No cracks after 1000 cycles ×: Cracks occurred after less than 1000 cycles

As can be seen from the above, by adjusting the composition to Examples 1 to 6, a photosensitive thermosetting developing resin composition with excellent printability, pencil hardness, and resistance to cold and hot shocks can be obtained. In contrast, in Comparative Example 1, since only barium sulfate is used as a filler, although the printability and pencil hardness are excellent, the resistance to cold and hot shocks is very low. In Comparative Example 2, since only talc is used as a filler, although the resistance to cold and hot shocks is excellent, the printability and pencil hardness are greatly deteriorated. Comparative Example 3 uses a combination of talc and barium sulfate, and Comparative Example 4 uses a combination of silica and barium sulfate, but neither can achieve excellent resistance to cold and hot shocks while taking into account both printability and pencil hardness. Comparative Examples 5 to 8 use talc and silicon dioxide at the same time. The ratio of the two in Comparative Example 5 is outside the scope of this application. In Comparative Examples 6 to 8, the total amount of the two is increased to 200 parts by weight. The cold and hot impact resistance cannot meet the requirements. Comparative Examples 6 and 8 sometimes even affect the printability or pencil hardness. Comparative Example 9 uses an equal amount of a phosphate dispersant BYK-145 on the basis of Example 2, and the printability and pencil hardness are greatly deteriorated.

[Figure 1] is a diagram showing a substrate used for evaluating printability in an embodiment. [Figure 2] is a schematic diagram showing cracks generated when used for evaluating heat and cold shock resistance in an embodiment. [Figure 3] is a schematic diagram showing no cracks generated when used for evaluating heat and cold shock resistance in an embodiment.

Claims (8)

A photosensitive thermosetting developing resin composition, characterized in that it contains (A) a vinyl ester resin, (B) a photopolymerization initiator, (C) a phosphate ester dispersant, (D) a compound having two or more ethylenically unsaturated groups in one molecule, and (E) an inorganic filler, The (C) phosphate ester dispersant contains a polymer having a phosphate ester structure in the main chain (C-1), The (E) inorganic filler contains talc and silica, and the total amount of talc and silica is 50 to 180 parts by weight relative to 100 parts by weight of the (A) vinyl ester resin calculated as solid content, and the ratio of talc is 20 to 80% by weight based on the total weight of talc and silica being 100% by weight. The photosensitive thermosetting developing resin composition of claim 1 further contains (F) other additives in addition to (B) a photopolymerization initiator and (C) a phosphate-based dispersant. The photosensitive thermosetting developing resin composition of claim 1 further comprises (G) an epoxy resin. The photosensitive thermosetting developable resin composition of claim 1 further comprises (H) an organic solvent. A photosensitive thermosetting developing resin composition as claimed in any one of claims 1 to 4, wherein the (C) phosphate ester dispersant further comprises a polymer having a phosphate ester structure in the side chain (C-2). A photocurable dry film is characterized in that it is obtained by applying the photosensitive thermosetting developing resin composition as described in any one of claims 1 to 5 on a carrier film and drying it. A cured product, characterized in that it is obtained by photocuring the following coating, wherein the coating is: a coating obtained by applying the photosensitive thermosetting developing resin composition as described in any one of claims 1 to 5 on copper and drying it; or a coating obtained by applying the photosensitive thermosetting developing resin composition on a carrier film and drying it, and pressing the obtained photocurable dry film layer on copper. A printed circuit board, characterized in that it has a cured product obtained by photocuring and then thermally curing a coating, wherein the coating is: a coating obtained by coating a photosensitive thermosetting developing resin composition as described in any one of claims 1 to 5 on a substrate and drying it; or a coating obtained by coating the photosensitive thermosetting developing resin composition on a carrier film and drying it, and then pressing the obtained photocurable dry film layer on a substrate.