Photosensitive thermosetting developable resin composition, dry film and cured product thereof, and printed circuit board formed using the same

Abstract

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

Description

Technical Field

[0001] The present invention relates to a photosensitive thermosetting developable resin composition suitable for forming a solder resist or the like for printed circuit boards, a dry film thereof, and a cured product thereof, and particularly relates to a photosensitive thermosetting developable resin composition having excellent printability and capable of forming a solder resist layer having excellent hardness and thermal shock resistance, a dry film thereof, a cured product thereof, and a printed circuit board. Background Art

[0002] Currently, alkaline-developable solder resists are used for some consumer printed circuit boards and almost all industrial printed circuit boards. These are developed after UV exposure to form an image, and then fully cured (primary cure) by heat and / or light irradiation. Furthermore, there is a trend toward using solder resists designed for high-reliability electronic materials as solder resists for printed circuit boards in semiconductor devices used in transportation vehicles such as automobiles, trains, ships, and aircraft.

[0003] However, conventional alkali-developable solder resist inks typically exhibit poor resistance to thermal shock cracking due to thermal expansion and contraction, and are less reliable with temperature fluctuations. While using talc as a filler can improve cracking, printability and hardness are poor. Alternatively, using talc and barium sulfate as fillers can meet the thermal shock resistance requirements for automotive solder resist inks, but this compromises printability and hardness.

[0004] For example, the fillers in the photocurable solder resist ink of Patent Document 1 include silica, barium sulfate and talc. The curable resin composition for 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 permanent mask of printed circuit boards, which contains: a resin containing ethylenically unsaturated groups and carboxyl groups 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. The UV-curable liquid photosensitive solder resist ink of Patent Document 4 records that the filler is barium sulfate, talc or silica.

[0005] Patent Document 1: CN114716868A

[0006] Patent Document 2: CN108137791A

[0007] Patent Document 3: CN101798432A

[0008] Patent Document 4: CN106380929A Summary of the Invention

[0009] Problems to be solved by the invention

[0010] The present invention aims to improve the printability of solder resist ink and the hardness of the dry film and cured product formed therefrom, while further improving the long-term reliability.

[0011] More specifically, the present invention aims to provide a photosensitive thermosetting developable resin composition having excellent printability and capable of forming a solder resist layer having excellent hardness and thermal shock resistance, a dry film thereof, a cured product thereof, and a printed wiring board.

[0012] Solutions for solving problems

[0013] The present inventors conducted extensive research to address the aforementioned issues and discovered that the types of fillers and additives significantly affect thermal shock resistance. The present invention was completed by developing a photosensitive thermosetting resin composition as described below, which addresses the aforementioned issues. The composition comprises (A) a vinyl ester resin, (B) a photopolymerization initiator, (C) a phosphate dispersant, (D) a compound having two or more ethylenically unsaturated groups in one molecule, and (E) an inorganic filler. The phosphate dispersant (C) comprises (C-1) a polymer having a phosphate structure in its main chain, and the inorganic filler (E) comprises talc and silica. The total amount of the talc and silica is 50 to 180 parts by weight relative to 100 parts by weight of the vinyl ester resin (A) on a solids basis, and the talc content is 20 to 80% by weight based on 100% by weight of the total weight of the talc and silica.

[0014] That is, the photosensitive thermosetting developable 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 (C-1) a polymer having a phosphate ester structure in its main chain, 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 solid content, and the ratio of talc is 20 to 80% by weight based on 100% by weight of the total weight of talc and silica.

[0015] Furthermore, it is preferred to contain (F) other additives in addition to the (B) photopolymerization initiator and the (C) phosphate ester dispersant.

[0016] Furthermore, it is preferred to contain (G) an epoxy resin.

[0017] Furthermore, it is preferred to contain (H) an organic solvent.

[0018] Furthermore, it is preferred that the (C) phosphate ester-based dispersant further contains (C-2) a polymer having a phosphate ester structure in a side chain.

[0019] Furthermore, the dry film of the present invention is characterized by being obtained by coating the photosensitive thermosetting developable resin composition on a carrier film and drying the coating.

[0020] Furthermore, the cured product of the present invention is characterized in that it is obtained by photocuring a coating film obtained by applying the photosensitive thermosetting developable resin composition on copper and drying it; or a coating film obtained by applying the photosensitive thermosetting developable resin composition on a carrier film and drying it, and laminating the resulting photocurable dry film on copper.

[0021] Furthermore, the printed wiring board of the present invention is characterized in that it is obtained by photocuring and then thermally curing a coating film obtained by coating the photosensitive thermosetting developable resin composition on a substrate and drying it; or by coating the photosensitive thermosetting developable resin composition on a carrier film and drying it, and laminating the resulting photocurable dry film on a substrate.

[0022] The greatest technical feature of the photosensitive thermosetting developable 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 (C-1) a polymer having a phosphate ester structure in its main chain, and the (E) inorganic filler comprises talc and silica.

[0023] Based on the characteristic composition of the present invention, by using a polymer with a phosphate structure in the main chain, and combining talc and silica, and optimizing the ratio of the two to replace the traditional filler barium sulfate, it is possible to improve printability and pencil hardness while effectively enhancing the resistance to cold and hot shock.

[0024] In contrast, the use of talc and barium sulfate as fillers can satisfy the thermal shock resistance requirements of solder resist inks, but the pencil hardness is poor (for example, Patent Document 1).

[0025] As described above, after repeated and in-depth research, the present inventors discovered that talc, as a filler, exhibits good flexibility and excellent crack resistance in the Temperature Cycle Test (hereinafter sometimes referred to as the "TCT test"). However, its surface hardness is significantly reduced. Furthermore, talc has a high oil absorption, which seriously deteriorates the printability of inks. Silicon dioxide, on the other hand, has a higher hardness and a lower oil absorption. By using both talc and silicon dioxide and optimizing their ratio, the aforementioned objectives of the present invention were achieved.

[0026] Effects of the Invention

[0027] As described above, the present invention can provide a photosensitive thermosetting developable resin composition having excellent printability and capable of forming a solder resist layer having excellent hardness and thermal shock resistance, a dry film thereof, a cured product thereof, and a printed wiring board. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a diagram showing a substrate used for evaluating printability in Examples.

[0029] FIG2 is a schematic diagram showing cracks generated when evaluating thermal shock resistance in an embodiment.

[0030] FIG3 is a schematic diagram showing that no cracks were generated when evaluating thermal shock resistance in an embodiment. DETAILED DESCRIPTION

[0031] Hereinafter, each constituent component in the photosensitive thermosetting developable resin composition of the present invention will be described.

[0032] The photosensitive thermosetting developable resin composition of the present invention is characterized by containing (E) an inorganic filler including talc and silica as essential components. Therefore, the (E) inorganic filler will be described first.

[0033] (E) Inorganic fillers

[0034] In the photosensitive thermosetting developable resin composition of the present invention, talc as the inorganic filler (E) is used to improve thermal shock resistance, and silica is used to improve printability.

[0035] The talc can be any parent rock selected from magnesium carbonate, serpentine, silica / silica-alumina, or magnesium precipitate, and can be any so-called silicate mineral. It can be in the form of blocks or fine powder. It may or may not be surface-treated. The talc preferably has an oil absorption of 20 to 100 ml / 100 g, preferably 30 to 90 ml / 100 g, and more preferably 40 to 80 ml / 100 g. The average particle size of the talc is preferably 1.0 to 20.0 μm, more preferably 2.0 to 10 μm, and even more preferably 3.0 to 8.0 μm.

[0036] Examples of commercially available products include HD25 manufactured by Shandong Pingdu Talc Mining Co., Ltd. and LMP-100 manufactured by Fuji Talc Industry Co., Ltd.

[0037] Silica may be amorphous or crystalline, or a mixture thereof. Amorphous (fused) silica is particularly preferred. Surface treatment may or may not be performed. The silica 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 silica is suitably 0.1 to 10.0 μm, more preferably 1.0 to 8.0 μm, and even more preferably 2.0 to 6.0 μm.

[0038] Examples of commercially available silica 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 Longsen, MLV-2114 manufactured by Longsen, SO-E5 manufactured by ADMATECHS, and SO-E2 manufactured by ADMATECHS.

[0039] 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 thermal shock resistance can be significantly improved. When it is less than 20 weight%, sufficient thermal shock resistance cannot be obtained. When it exceeds 80 weight%, although the thermal shock resistance is still excellent, the printability and the surface hardness of the solder mask tend to decrease. It is speculated that because talc has a large oil absorption, its excessive use will greatly affect the printability of the ink. Silica has a higher hardness and a lower oil absorption. By mixing the two in a suitable ratio, it is achieved that while taking into account printability and pencil hardness (at least 4H, preferably 6H or more), thermal shock resistance is improved (withstand at least 1000 cycles under -40℃ to 160℃ thermal cycling conditions).

[0040] 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 vinyl ester resin (A), calculated as a solid content. Within this range, excellent thermal shock resistance is achieved while ensuring both printability and hardness.

[0041] From the viewpoint of further satisfying thermal shock resistance, pencil hardness, and printability, the photosensitive thermosetting developable resin composition of the present invention preferably does not contain barium sulfate.

[0042] (A) Vinyl ester resin

[0043] The (A) vinyl ester resin in the photocurable thermosetting resin composition of the present invention can use a known resin that is used to impart alkali developability and contains an ethylenically unsaturated double bond in the molecule. From the aspects of photocurability and development resistance, carboxyl-containing resins having an ethylenically unsaturated double bond in the molecule are 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 carbamate skeleton, a copolymer resin having a copolymer structure of an unsaturated carboxylic acid, or a resin using a phenol compound as a starting material is preferred. Specific examples of the (A) vinyl ester resin are shown below.

[0044] (1) Vinyl ester resins obtained by copolymerizing an unsaturated carboxylic acid such as (meth)acrylic acid with one or more other compounds having an unsaturated double bond;

[0045] (2) Photosensitive vinyl ester resins obtained by adding an ethylenically unsaturated group as a pendant group 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 a compound having an epoxy group and an unsaturated double bond, such as glycidyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, or (meth)acryloyl chloride;

[0046] (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-epoxycyclohexylmethyl (meth)acrylate, and another compound having an unsaturated double bond, with an unsaturated carboxylic acid, such as (meth)acrylic acid, and reacting a polybasic acid anhydride with the resulting secondary hydroxyl group;

[0047] (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;

[0048] (5) vinyl ester resins obtained by reacting a polyfunctional epoxy compound with an unsaturated monocarboxylic acid and reacting a saturated or unsaturated polybasic acid anhydride with the resulting hydroxyl group;

[0049] (6) A vinyl ester resin containing hydroxyl groups and carboxyl groups obtained by reacting a hydroxyl-containing polymer such as a polyvinyl alcohol derivative with a saturated or unsaturated polybasic acid anhydride, and then reacting a compound having an epoxy group and an unsaturated double bond in one molecule with the resulting carboxylic acid;

[0050] (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 an epoxy group in one molecule, with a saturated or unsaturated polybasic acid anhydride;

[0051] (8) a vinyl ester resin obtained by reacting an unsaturated monocarboxylic acid with a polyfunctional oxetane compound having at least two oxetane rings in one molecule, and reacting a saturated or unsaturated polybasic acid anhydride with the primary hydroxyl group in the resulting modified oxetane resin; and

[0052] (9) A vinyl ester resin obtained by reacting a carboxyl group-containing resin obtained by reacting an unsaturated monocarboxylic acid with a polyfunctional epoxy resin and then with a polyacid anhydride, and further reacting the carboxyl group-containing resin with a compound having one oxirane ring and one or more ethylenically unsaturated groups in the molecule;

[0053] (10) Vinyl ester resins obtained by reacting a bifunctional epoxy compound with an unsaturated monocarboxylic acid and reacting a saturated or unsaturated polybasic acid anhydride with the generated hydroxyl group.

[0054] Among these examples, particularly preferred are the vinyl ester resins (2), (5), (7), and (9).

[0055] It should be noted that, in this specification, (meth)acrylate is a term that collectively refers to acrylate, methacrylate, and a mixture thereof, and the same applies to other similar expressions.

[0056] Since the vinyl ester resin (A) described above has a plurality of free carboxyl groups on the side chains of the main polymer, it can be developed with a dilute aqueous alkaline solution.

[0057] 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 group-containing resin is less than 40 mgKOH / g, alkali development becomes difficult. On the other hand, if it exceeds 200 mgKOH / g, dissolution of the exposed portion by the developer is promoted, resulting in thinner lines than desired. In some cases, the exposed and unexposed portions may be dissolved and peeled off indiscriminately by the developer, making it difficult to form a normal resist pattern. This is not preferred.

[0058] The weight-average molecular weight of the vinyl ester resin (A) varies depending on the resin backbone, but is generally preferably in the range of 2,000 to 150,000, more preferably 5,000 to 100,000. A weight-average molecular weight of less than 2,000 may result in poor application to a substrate and tack-free performance after drying. Furthermore, the moisture resistance of the coating film after exposure may deteriorate, film loss may occur during development, and resolution may be significantly reduced. On the other hand, a weight-average molecular weight exceeding 150,000 may result in significantly poor developability and reduced storage stability.

[0059] The blending amount of the vinyl ester resin (A) is preferably in the range of 20 to 60% by mass, and preferably 25 to 50% by mass, based on the total solid content of the composition. 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 greater than the above range, the viscosity of the composition increases, or the coating properties are reduced, which is not preferred.

[0060] (B) Photopolymerization initiator

[0061] The photopolymerization initiator used in the photosensitive thermosetting developable resin composition of the present invention is not particularly limited as long as it is a photopolymerization initiator generally used in photosensitive thermosetting developable resin compositions.

[0062] As the photopolymerization initiator, a known substance 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; thioxanthones such as isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diisopropylthioxanthone, and 2-chlorothioxanthone; ketals such as acetophenone dimethyl ketal and benzil dimethyl ketal; benzophenones such as benzophenone, 4-(1-tert-butyldioxy-1-methylethyl)benzophenone, and 3,3',4,4'-tetrakis(tert-butyldioxycarbonyl)benzophenone; and xanthones, etc.

[0063] As the photopolymerization initiator, oxime ester-based photopolymerization initiators having an oxime ester group, alkylphenone-based photopolymerization initiators, α-aminoacetophenone-based photopolymerization initiators, acylphosphine oxide-based photopolymerization initiators, titanocene-based photopolymerization initiators, and the like can also be used.

[0064] 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. Photopolymerization initiators having two oxime ester groups in the molecule are preferably used, and specifically, oxime ester compounds having a carbazole ring structure are exemplified.

[0065] Examples of commercially available alkylphenone-based photopolymerization initiators include α-hydroxyalkylphenone-based products such as Omnirad 184, Omnirad 1173, Omnirad 2959, and Omnirad 127 manufactured by IGM Resins BV.

[0066] Specific examples of α-aminoacetophenone-based photopolymerization initiators 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. Commercially available products include Omnirad 907, Omnirad 369, and Omnirad 379 manufactured by IGM Resins BV.

[0067] Specific examples of the acylphosphine oxide-based photopolymerization initiator include 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide, and trifunctional or higher-functional acylphosphine-based photopolymerization initiators. The trifunctional or higher-functional 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).

[0068]

[0069] Wherein.

[0070] A independently represents a single bond, O, S or NR 3 ;

[0071] G is a multifunctional compound (core) G-(AH) m+n A residue wherein AH each represents an alcohol group, an amino group or a thiol group;

[0072] m and n are both integers, and m+n is an integer between 3 and 10;

[0073] m is an integer between 3 and 8;

[0074] R1 and R2 are independently C1-C 18 Alkyl, C6-C 12 Aryl and C5-C 12 wherein R1 and R2 are independently a five- to six-membered heterocyclic group containing oxygen and / or nitrogen and / or sulfur atoms, wherein each of the aforementioned groups is optionally substituted by an aryl group, an alkyl group, an aryloxy group, an alkoxy group, a heteroatom and / or a heterocyclic group;

[0075] R2 may be R1-(C=O)-;

[0076] Y is O or S;

[0077] R3 is hydrogen or a C1-C4 alkyl group;

[0078] The photopolymerization initiator of formula (I) does not contain a photocurable ethylenically unsaturated group.

[0079] 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.

[0080] In formula (I), when A is oxygen, G-(AH) m+n is a polyhydroxy compound selected from the group consisting of monomeric polyols, oligomeric polyols, polymeric 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 It 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 practicing the present invention does not contain a photocurable ethylenically unsaturated group. When A is a single bond, G- is G-(AH) listed above. m+n The residue after removing the hydroxyl group and / or amino group and / or thiol group.

[0081] G-(AH) is preferred m+n It has a number average molecular weight of 1500 or less, more preferably 800 or less, and further preferably 500 or less.

[0082] When n is not 0, the compound of formula (I) has an alcoholic free group and / or an amino group and / or a mercapto group.

[0083] Representative trifunctional or higher-functional 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. The inclusion of such trifunctional or higher-functional acylphosphine photopolymerization initiators can provide a cured product with suppressed outgassing and superior insulation reliability.

[0084] Table 1

[0085]

[0086]

[0087]

[0088]

[0089]

[0090]

[0091]

[0092] Such a trifunctional or higher-functional acylphosphine-based photopolymerization initiator can be produced by the method described in, for example, Japanese Patent No. 6599446.

[0093] As commercially available products of the acylphosphine oxide-based photopolymerization initiator, Omnirad TPO manufactured by IGM Resins, Omnirad 819 and Omnipol TP manufactured by IGM Resins BV, etc. can be used.

[0094] Specific examples of the titanocene-based photopolymerization initiator include bis(cyclopentadienyl)-diphenyltitanium, 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. Commercially available products include Omnirad 784 manufactured by IGM Resins BV.

[0095] 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) as a solid content. If the amount of the photopolymerization initiator used is less than the above range, the photocurability of the composition deteriorates. On the other hand, if the amount is too high, the properties as a solder resist are deteriorated, which is not preferred.

[0096] (C) Phosphate-based dispersants

[0097] The (C) phosphate dispersant used in the photosensitive thermosetting developable 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 side chain.

[0098]

[0099] 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.

[0100] Furthermore, the present inventors have discovered that, in order to achieve both ink printability and solder mask surface hardness while improving thermal shock resistance, it is more preferable to use a polymer having a phosphate ester structure in the main chain (i.e., a polyphosphate ester polymer) and a polymer having a phosphate ester structure in the side chain as the phosphate ester dispersant (C) in addition to talc as a filler. In this case, the mixing ratio of the two, i.e., (C-1) polymer having a phosphate ester structure in the main chain: (C-2) polymer having a phosphate ester structure in the side chain, by weight, is preferably 1:10 to 10:1, preferably 1:5 to 5:1, more preferably 1:3 to 3:1, and even more preferably 1:2 to 2:1. This allows for the production of a photosensitive thermosetting developable resin composition that exhibits excellent ink printability, solder mask surface hardness, and thermal shock resistance.

[0101] The blending ratio of the (C) phosphate ester dispersant is preferably 0.01 to 20 parts by weight, preferably 0.1 to 15 parts by weight, and more preferably 1 to 10 parts by weight, per 100 parts by weight of the (A) vinyl ester resin, calculated as solids. Within this range, the (C) phosphate ester dispersant ensures excellent thermal shock resistance while maintaining both printability and hardness. Exceeding this range is undesirable because solder resist properties are degraded.

[0102] Examples of commercially available 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, and BYK-145 (manufactured by BYK-Chemie GmbH).

[0103] It should be noted that, in this specification, the term "polymer" is a general term for homopolymers, copolymers and mixtures thereof, and the same applies to other similar expressions.

[0104] (D) Compounds having two or more ethylenically unsaturated groups in one molecule

[0105] The compound (D) having two or more ethylenically unsaturated groups in one molecule used in the photosensitive thermosetting developable resin composition of the present invention is a compound that renders the vinyl ester resin (A) insoluble in an alkaline aqueous solution, or contributes to the insolubility of the vinyl ester resin in an alkaline aqueous solution, by photocuring upon irradiation with active energy rays. Specific examples of such compounds include:

[0106] Hydroxyalkyl acrylates such as 2-hydroxyethyl acrylate and 2-hydroxypropyl acrylate;

[0107] Monoacrylates or diacrylates of glycols such as ethylene glycol, methoxytetraethylene glycol, polyethylene glycol, and propylene glycol;

[0108] Acrylamides such as N, N-dimethylacrylamide, N-hydroxymethylacrylamide, N, N-dimethylaminopropylacrylamide, etc.

[0109] Aminoalkyl acrylates such as N,N-dimethylaminoethyl acrylate and N,N-dimethylaminopropyl acrylate;

[0110] Polyacrylates of polyols such as hexanediol, trimethylolpropane, pentaerythritol, dipentaerythritol, trishydroxyethyl isocyanurate, or their ethylene oxide adducts or propylene oxide adducts;

[0111] Acrylates such as phenoxy acrylate, bisphenol A diacrylate, and ethylene oxide adducts or propylene oxide adducts of these phenols;

[0112] Acrylates of glycidyl ethers such as glycerol diglycidyl ether, glycerol triglycidyl ether, trimethylolpropane triglycidyl ether, and triglycidyl isocyanurate;

[0113] and melamine acrylate, and at least any one of the methacrylates corresponding to the above-mentioned acrylates.

[0114] Furthermore, epoxy acrylate resins obtained by reacting a polyfunctional epoxy resin such as a cresol novolac epoxy resin with acrylic acid, and epoxy urethane acrylate compounds obtained by reacting a hydroxyl group of the epoxy acrylate resin with a half urethane compound of a hydroxy acrylate such as pentaerythritol triacrylate and a diisocyanate such as isophorone diisocyanate, etc. can also be mentioned.

[0115] The compound (D) having two or more ethylenically unsaturated groups in one molecule is preferably present 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 vinyl ester resin (A) as a solid component. If the amount is less than 5 parts by weight relative to 100 parts by weight of the vinyl ester resin (A), the resulting photocurable thermosetting resin composition exhibits reduced photocurability, making it 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 aqueous alkaline solutions decreases, and the cured coating film becomes brittle, which is not preferred.

[0116] (F) Other additives

[0117] As described above, the other additives in the present invention refer to additives other than the (B) photopolymerization initiator and the (C) phosphate-based dispersant.

[0118] Examples of such additives include known and commonly used colorants such as phthalocyanine blue, phthalocyanine green, iodine green, disazo yellow, crystal violet, titanium oxide, carbon black, and naphthalene black; known and commonly used thermal polymerization inhibitors such as hydroquinone, hydroquinone monomethyl ether, tert-butylcatechol, pyrogallol, and phenothiazine; known and commonly used thickeners such as fine powder silica, organic bentonite, and montmorillonite; at least one of silicone-based, fluorine-based, and polymer-based defoamers and leveling agents; adhesion-imparting agents such as imidazole-based, thiazole-based, and triazole-based; silane coupling agents; phenol-based, phosphorus-based, and sulfur-based antioxidants; and hindered amine-based light stabilizers.

[0119] The compounding ratio of such (F) other additives is preferably 0.01% by weight or more and 20% by weight or less of the total amount of the photosensitive thermosetting developable resin composition. If it is less than 0.01% by weight, the corresponding effect cannot be fully obtained, and if it exceeds 20% by weight, the printability and hardness of the photosensitive thermosetting developable resin composition deteriorate, which is not preferred.

[0120] (G) Epoxy resin

[0121] In order to impart heat resistance, the photosensitive thermosetting developable resin composition used in the present invention preferably contains an epoxy resin having at least two epoxy groups in its molecule, ie, a multifunctional epoxy resin (G).

[0122] Examples of commercially available products include bisphenol A-type epoxy resins such as 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.; DER317, DER331, DER661, and DER664 manufactured by Dow Chemical Company; and Sumi-Epoxy ESA-011, ESA-014, ELA-115, and ELA-128 manufactured by Sumitomo Chemical Industries, Ltd. (all trade names); jERYL903 manufactured by Mitsubishi Chemical Corporation; and EPICLON 152 and EPICLON 153 manufactured by DIC Corporation. 165. EPOTOTE YDB-400 and YDB-500 manufactured by NIPPON STEEL Chemical & Material Co., Ltd., DER542 manufactured by Dow Chemical Company, Sumi-Epoxy ESB-400 and ESB-700 manufactured by Sumitomo Chemical Industries, Ltd. (all trade names) brominated epoxy resins; jER152 and jER154 manufactured by Mitsubishi Chemical Corporation, DEN431 and DEN438 manufactured by Dow Chemical Company, EPICLON N-730, EPICLON N-770 and EPICLON N-865 manufactured by DIC Corporation, EPOTOTE manufactured by NIPPON STEEL Chemical & Material Co., Ltd. YDCN-701, YDCN-704, 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., NIPPON STEEL Chemical & Material Co., Ltd.Novolac-type epoxy resins such as YDCN-700-2, YDCN-700-3, YDCN-700-5, YDCN-700-7, YDCN-700-10, YDCN-704, and YDCN-704A manufactured by DIC Corporation; EPICLON N-680, N-690, and N-695 manufactured by DIC Corporation (all trade names); EPICLON 830 manufactured by DIC Corporation; jER807 manufactured by Mitsubishi Chemical Corporation; EPOTOTE YDF-170, YDF-175, and YDF-2004 manufactured by NIPPON STEEL Chemical & Material Co., Ltd. (all trade names); and EPOTOTE manufactured by NIPPON STEEL Chemical & Material Co., Ltd. ST-2004, ST-2007, ST-3000 (trade names), hydrogenated bisphenol A type epoxy resins such as YX8034 manufactured by Mitsubishi Chemical Corporation; jER604 manufactured by Mitsubishi Chemical Corporation, EPOTOTE YH-434 manufactured by NIPPON STEEL Chemical & Material Co., Ltd., Sumi-EpoXy ELM-120 manufactured by Sumitomo Chemical Industries, Ltd. (all trade names) glycidylamine type epoxy resins; hydantoin type epoxy resins; CELLOXIDE manufactured by Daicel Corporation 2021P and other (trade names) alicyclic epoxy resins; YL-933 manufactured by Mitsubishi Chemical Corporation, EPPN-501, EPPN-502 and other (all trade names) trihydroxyphenylmethane type epoxy resins manufactured by Nippon Kayaku Co., Ltd.; YL-6056, YX-4000, YL-6121 (all trade names) and other bixylenol type or biphenol type epoxy resins or mixtures thereof manufactured by Mitsubishi Chemical Corporation; EBPS-200, ADE Bisphenol S-type epoxy resins such as EPX-30 manufactured by KA Corporation and EXA-1514 (trade name) manufactured by DIC Corporation; bisphenol A novolac-type epoxy resins such as jER157S (trade name) manufactured by Mitsubishi Chemical Corporation; tetrahydroxyphenylethane-type epoxy resins such as jERYL-931 (trade name) manufactured by Mitsubishi Chemical Corporation; heterocyclic epoxy resins such as TEPIC (trade name) manufactured by Nissan Chemical Industries, Ltd.; diglycidyl phthalate resins such as BRENMAR DGT manufactured by NOF Corporation; tetraglycidyl ditoluoylethane resins such as ZX-1063 manufactured by Nippon Steel Chemical & Material Co., Ltd.; and Nippon Steel Chemical & Material Co., Ltd.Examples include, but are not limited to, naphthalene skeleton-containing epoxy resins such as ESN-190 and ESN-360, DIC Corporation's HP-4032, EXA-4750, and EXA-4700, glycidyl methacrylate copolymer epoxy resins such as CP-50S and CP-50M manufactured by NOF Corporation, and copolymerized epoxy resins of cyclohexylmaleimide and glycidyl methacrylate, and CTBN-modified epoxy resins (e.g., YR-102 and YR-450 manufactured by NIPPON STEEL Chemical & Material Co., Ltd.). These epoxy resins may be used alone or in combination of two or more.

[0123] The content of the epoxy resin (G) 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, relative to 100 parts by weight of the vinyl ester resin (A) in terms of solid content.

[0124] (H) organic solvent

[0125] The organic solvent (H) that can be used in the photosensitive thermosetting developable resin composition of the present invention can be used to synthesize the carboxyl group-containing resin (A), prepare the composition, or adjust the viscosity for coating on a substrate or a carrier film.

[0126] Examples of such organic solvents include ketones, aromatic hydrocarbons, glycol ethers, glycol ether acetates, esters, alcohols, aliphatic hydrocarbons, and petroleum solvents. More specifically, they include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; glycol ethers such as cellosolve, methyl cellosolve, butyl cellosolve, 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; and petroleum solvents such as petroleum ether, naphtha, hydrogenated naphtha, and solvent naphtha. The above organic solvents may be used alone or in the form of a mixture of two or more.

[0127] When the photosensitive thermosetting developable resin composition of the present invention is used to form a solder resist for a printed circuit board, the composition can be applied to, for example, a pre-formed printed circuit board by screen printing, curtain printing, spraying, or roller coating, after adjusting the viscosity as needed. A tack-free coating film can be formed by drying the composition at, for example, approximately 60 to 100°C, as needed. The composition can then be selectively exposed to active light through a photomask having a predetermined exposure pattern, and the unexposed areas developed with an alkaline aqueous solution to form a resist pattern. Furthermore, the composition can be heat-cured by, for example, heating to approximately 140 to 180°C, thereby promoting the curing reaction of the epoxy resin and the polymerization of the vinyl ester resin, thereby improving various properties of the resulting resist film, including hardness, thermal shock resistance, heat resistance, solvent resistance, acid resistance, moisture absorption resistance, PCT resistance, adhesion, and electrical properties.

[0128] As the aqueous alkali solution used in the above-mentioned development, aqueous alkali solutions of potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate, ammonia, amines, etc. can be used. 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-state laser, a xenon lamp, or a metal halide lamp is suitable.

[0129] In addition to directly applying the liquid form of the photosensitive thermosetting developable resin composition of the present invention to a substrate, the photosensitive thermosetting developable resin composition can also be used in the form of a photocurable dry film obtained by pre-coating the photosensitive thermosetting developable resin composition on a carrier film and drying it. The following describes the use of the photosensitive thermosetting developable resin composition of the present invention in the form of a photocurable dry film.

[0130] A photocurable dry film has a structure composed of a carrier film, a resin layer, and, if necessary, a removable cover film laminated in sequence. The resin layer is obtained by coating the photosensitive thermosetting developable resin composition of the present invention onto a carrier film or a cover film and drying it. A dry film can be obtained by forming the resin layer on the carrier film and then laminating the cover film thereon, or by forming the resin layer on the cover film and then laminating this laminate onto the carrier film.

[0131] The carrier film can be a thermoplastic film such as polyester film with a thickness of 2 to 150 μm. The resin layer is formed by uniformly coating the photosensitive thermosetting developable resin composition on the carrier film or cover film with a thickness of 10 to 150 μm using a knife coater, lip coater, comma coater, or film coater, followed by drying. Polyethylene film, polypropylene film, or the like can be used as the cover film, and preferably a cover film with a lower adhesion to the resin layer than to the carrier film is preferred.

[0132] The cured product of the present application is obtained by photocuring the following coating film, wherein the coating film is: a coating film obtained by applying a photosensitive thermosetting developable resin composition on copper and drying it; or a coating film obtained by applying the photosensitive thermosetting developable resin composition on a carrier film and drying it, and laminating the obtained photocurable dry film on copper.

[0133] When using a photocurable dry film to create a cured product on a printed circuit board with copper circuits, the cover film is removed, and the resin layer is superimposed on the substrate with the circuits formed thereon. Lamination is performed using a laminator or the like to form a resin layer on the substrate with the circuits formed thereon. The formed resin layer is then exposed, developed, and heat-cured in the same manner as described above to form a cured product. The carrier film can be removed either before or after exposure.

[0134] The photosensitive thermosetting developable resin composition is suitably used for forming a cured film on a printed circuit board. The cured film is preferably a permanent insulating film, and particularly preferably a solder resist layer.

[0135] Example

[0136] The present invention will be described in further detail based on Examples and Comparative Examples. However, the scope of the present invention and its embodiments are not limited thereto. "Parts" or "%" in the Examples and Comparative Examples are by weight unless otherwise specified. The properties of the compositions of these Examples were tested using the methods described below.

[0137] Synthesis example

[0138] In a four-necked flask equipped with a stirrer and a reflux condenser, 214 parts of cresol novolac-type epoxy resin EPICLON N-695 (manufactured by DIC, epoxy equivalent = 214) were added, followed by 103 parts of carbitol acetate and 103 parts of a petroleum hydrocarbon solvent (trade name: Cactus Fines SF-01, manufactured by Japan Energy Corporation) and dissolved by heating. Subsequently, 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 was slowly added dropwise, and the mixture was allowed to react for 16 hours. The resulting reaction product was cooled to 80-90°C, 91.2 parts of tetrahydrophthalic anhydride was added, the mixture was allowed to react for 8 hours, and then cooled and removed. The resulting carboxyl vinyl ester resin had a nonvolatile content of 65% and an acid value of 87.5 mgKOH / g on the solids.

[0139] The vinyl ester resin solution (varnish) from the synthesis example was blended with the various components and proportions (parts by weight) shown in Table 1. After premixing with a stirrer, the mixture was kneaded with a three-roll mill to prepare a photosensitive thermosetting developable resin composition. Printability, pencil hardness, and thermal shock resistance were evaluated according to the following methods.

[0140] Table 1

[0141]

[0142] “-” means not added

[0143] A cresol novolac type epoxy modified acrylic resin (solid content 65%) prepared as in the above synthesis example

[0144] Pigment F: Phthalocyanine Green, Pigment A manufactured by DIC Corporation

[0145] Defoaming agent: KS-66, manufactured by Shin-Etsu Chemical Co., Ltd.

[0146] C-1 Phosphate ester dispersant: BYK-110, polyphosphate, polyphosphate polymer, manufactured by BYK Chemie, solid content 52% by mass, oil absorption 63 ml / 100 g

[0147] C-2 Phosphate ester dispersant: BYK-142, a compound of the reaction product of 2-ethylhexyl acrylate and (ethylenediamine and ethyleneimine polymer) and polyethylene polypropylene glycol monobutyl ether phosphate, manufactured by BYK Chemie, solid content 60% by mass, oil absorption 29 ml / 100 g

[0148] B Photopolymerization initiator: Omnirad 369E, manufactured by IGM

[0149] E talc: LMP-100, manufactured by FUJI TALC INDUSTRIAL

[0150] Silica: A-8 manufactured by Sibelco

[0151] Barium sulfate: B-30, manufactured by Sakai Chemical Industry Co., Ltd.

[0152] H solvent: PGMEA, propylene glycol monomethyl ether acetate CC

[0153] G epoxy resin: N-770-75EA, manufactured by DIC Corporation, a novolac-type multifunctional epoxy resin, solid content 75% by mass

[0154] D Compounds with two or more ethylenically unsaturated groups in one molecule: MT-3501G, manufactured by Zhangjiagang Dongya DIC Chemical Co., Ltd.

[0155] Performance evaluation:

[0156] (1) Printability

[0157] The photosensitive thermosetting developable resin composition of the Examples and Comparative Examples was applied to the entire surface of a substrate having a 100 μm copper thickness and a 400 μm diameter opening pattern with a pitch of 600 μm by screen printing. After standing at room temperature for 30 minutes, it was dried in a hot air circulation drying oven at 80°C for 30 minutes to prepare a printability evaluation substrate. The printability evaluation substrate was observed using a 100x optical microscope to evaluate the bubble generation rate in the copper openings (see Figure 1 ). The evaluation criteria are as follows.

[0158] ○: Bubble generation rate is less than 40%

[0159] △: Bubble generation rate 40% or more and less than 50%

[0160] ×: Bubble generation rate 50% or more

[0161] (2) Pencil hardness

[0162] The photosensitive thermosetting developable resin composition of the above-mentioned examples and comparative examples was applied to the entire surface of a copper-clad laminate substrate that had been pre-treated by polishing 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 exposed to light at 400 mJ / cm using an exposure device equipped with a high-pressure mercury lamp. 2 Pattern exposure was performed, and development was performed for 50 seconds using a 1% by 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 film after thermal curing was measured according to JIS K 5600-5-4. The evaluation criteria are as follows.

[0163] ○: Pencil hardness 6H or above

[0164] △: Pencil hardness 4H or higher and lower than 6H

[0165] ×: Pencil hardness is less than 4H

[0166] (3) Resistance to cold and heat shock

[0167] The photosensitive thermosetting developable resin compositions of the examples and comparative examples were applied to the entire surface of a substrate having a 2 mm copper wire pattern by screen printing to 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 exposure apparatus equipped with a high-pressure mercury lamp was used to expose the substrate at 400 mJ / cm 2 The pattern was exposed, 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. 2 Seventeen substrates with rectangular resist patterns were fabricated for thermal cycle crack resistance evaluation by irradiating the substrates with ultraviolet light under conditions of 10°C. Several of the evaluation substrates fabricated as described above were placed in a thermal cycler that cycled between -40°C and 160°C, and subjected to thermal shock cycle tests (TCT tests) at various cycle times. The appearance of the substrates was then observed at each cycle, and the maximum number of cycles without cracking was recorded. The evaluation criteria are shown below (see Figures 2 and 3 for schematic diagrams of crack generation and non-crack generation).

[0168] ○: No cracks after 1000 cycles

[0169] ×: Cracks occurred at less than 1000 cycles

[0170] As can be seen from the above, by adjusting the composition to that of Examples 1 to 6, a photosensitive thermosetting developable resin composition having excellent printability, pencil hardness, and thermal shock resistance can be obtained. In contrast, in Comparative Example 1, since only barium sulfate was used as a filler, although the printability and pencil hardness were excellent, the thermal shock resistance was very low. In Comparative Example 2, since only talc was used as a filler, although the thermal shock resistance was excellent, the printability and pencil hardness were significantly deteriorated. Comparative Example 3 used a combination of talc and barium sulfate, and Comparative Example 4 used a combination of silica and barium sulfate, but neither was able to achieve excellent thermal shock resistance while taking into account both printability and pencil hardness. Comparative Examples 5 to 8 used both talc and silica, and the ratio of the two in Comparative Example 5 was outside the scope of this application. In Comparative Examples 6 to 8, the total amount of the two was increased to 200 parts by weight, but the thermal shock resistance did not meet the requirements. Comparative Examples 6 and 8 even sometimes affected the printability or pencil hardness. Comparative Example 9 uses the same amount of BYK-145, a phosphate ester dispersant, as in Example 2. However, the printability and pencil hardness are significantly deteriorated.

Claims

1. A photosensitive thermosetting developable resin composition, characterized in that: Containing (A) a vinyl ester resin, (B) a photopolymerization initiator, (C) a phosphate-based dispersant, (D) a compound having two or more ethylenically unsaturated groups in one molecule, and (E) an inorganic filler, The (C) phosphate ester dispersant comprises (C-1) a polymer having a phosphate ester structure in the main chain and (C-2) a polymer having a phosphate ester structure in the side chain. The (E) inorganic filler comprises talc and silica, wherein the total amount of the talc and silica is 50 to 180 parts by weight relative to 100 parts by weight of the (A) vinyl ester resin in terms of solid content, and the ratio of the talc is 20 to 80% by weight based on 100% by weight of the total weight of the talc and silica.

2. The photosensitive thermosetting developable resin composition according to claim 1, wherein It further contains (F) other additives in addition to (B) the photopolymerization initiator and (C) the phosphate ester dispersant.

3. The photosensitive thermosetting developable resin composition according to claim 1, wherein It further contains (G) an epoxy resin.

4. The photosensitive thermosetting developable resin composition according to claim 1, wherein It also contains (H) an organic solvent.

5. A photocurable dry film, characterized in that: The photosensitive thermosetting developable resin composition according to any one of claims 1 to 4 is applied on a carrier film and dried.

6. A cured product, characterized in that: The coating film is obtained by photocuring the following coating film: the coating film is obtained by coating the photosensitive thermosetting developable resin composition according to any one of claims 1 to 4 on copper and drying it; or the coating film is obtained by coating the photosensitive thermosetting developable resin composition on a carrier film and drying it, and laminating the obtained photocurable dry film on copper.

7. A printed circuit board, characterized in that: The invention provides a cured product obtained by photocuring and then thermally curing a coating film, wherein the coating film is obtained by coating the photosensitive thermosetting developable resin composition according to any one of claims 1 to 4 on a substrate and drying it; or a coating film obtained by coating the photosensitive thermosetting developable resin composition on a carrier film and drying it, and laminating the obtained photocurable dry film on a substrate.

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