CN106200266B

CN106200266B - Curable resin composition, dry film, cured product, and printed wiring board

Info

Publication number: CN106200266B
Application number: CN201610576040.XA
Authority: CN
Inventors: 福田晋一朗
Original assignee: Taiyo Ink Mfg Co Ltd
Current assignee: Taiyo Holdings Co Ltd
Priority date: 2015-07-21
Filing date: 2016-07-21
Publication date: 2020-01-24
Anticipated expiration: 2036-07-21
Also published as: CN106200266A

Abstract

[ problem ] to provide a curable resin composition having a cured product that has excellent heat resistance and elongation, a dry film having a resin layer obtained from the composition, a cured product of the composition or the resin layer of the dry film, and a printed wiring board having the cured product. [ solution ] A curable resin composition and the like, characterized by comprising (A) a carboxyl group-containing resin, (B) a thermosetting component, and (C) a borate ester compound.

Description

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

Technical Field

The invention relates to a curable resin composition, a dry film, a cured product and a printed circuit board.

Background

In a printed wiring board, a solder resist is formed on a base material having a conductor layer of a circuit pattern. In addition to such solder resists, various curable resin compositions have been proposed as materials for interlayer insulating materials for printed wiring boards, permanent protective films for coverlays for flexible printed wiring boards, and the like.

For example, patent document 1 discloses a photosensitive curable resin composition for a permanent resist, which contains a polymer having a carboxyl group, a photopolymerizable compound having an ethylenically unsaturated bond, and a photopolymerization initiator. Further, as a material of the permanent protective film, a thermosetting resin composition is also known (for example, patent document 2).

Such a permanent protective film is required to have resistance to deterioration such as peeling and cracking, i.e., reliability, even under severe environments. As one of the characteristics for realizing high reliability, heat resistance is given. For example, solder resists require solder heat resistance. In addition, printed circuit boards that can be used in high-temperature environments, for example, printed circuit boards for vehicles, are also required to have a permanent protective film with high heat resistance. In addition, in the case of performing patterning of a permanent protective film by cutting a cured product by laser processing, it is necessary to impart heat resistance so as not to be deteriorated by laser heat.

As another characteristic for achieving high reliability, elongation may be mentioned. If the elongation is low, cracks are likely to occur due to impact. Further, in the case of pattern formation by laser processing, there is a risk of cracks being generated due to openings resulting from laser processing.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2005-99647 (claims)

Patent document 2: japanese patent laid-open publication No. 2011-63653 (claims).

Disclosure of Invention

Problems to be solved by the invention

Accordingly, an object of the present invention is to provide a curable resin composition having a cured product excellent in heat resistance and elongation, a dry film having a resin layer obtained from the composition, a cured product of the composition or the resin layer of the dry film, and a printed wiring board having the cured product.

Means for solving the problems

The present inventors have conducted extensive studies in view of the above circumstances, and as a result, have found that the above problems can be solved by blending a borate ester compound, and have completed the present invention.

That is, the curable resin composition of the present invention is characterized by containing (a) a carboxyl group-containing resin, (B) a thermosetting component, and (C) a borate ester compound.

The curable resin composition of the present invention preferably contains a liquid epoxy resin as the (B) thermosetting component.

The curable resin composition of the present invention preferably further contains a photopolymerization initiator.

The curable resin composition of the present invention is preferably used for forming a solder resist, a cover lay or an interlayer insulating material.

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

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

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

Effects of the invention

According to the present invention, a curable resin composition having a cured product excellent in heat resistance and elongation, a dry film having a resin layer obtained from the composition, a cured product of the composition or the resin layer of the dry film, and a printed wiring board having the cured product can be provided.

Drawings

FIG. 1: a schematic side view of 2 tubes for liquid state determination of a thermocurable component is shown.

Detailed Description

The curable resin composition of the present invention is characterized by containing (A) a carboxyl group-containing resin, (B) a thermosetting component, and (C) a borate ester compound.

The curable resin composition of the present invention is improved in heat resistance and elongation by blending (C) the borate ester compound, and also improved in drying control width in the case of an alkali development type photocurable resin composition.

The drying control range (also referred to as development life) is a range of drying conditions under which development failure does not occur in a drying step performed after the alkali-developable photocurable resin composition is applied to a substrate and before development. If the drying management range is short, drying must be performed at a defined drying temperature and drying time. In an actual manufacturing process, it is not easy to control the drying time to a short time, and as a result, it becomes difficult to form a pattern with good developability. Conventionally, an alkali-developable photocurable resin composition for forming a solder resist or the like having high heat resistance has a problem of short drying control margin. The reason why the drying control width of such an alkali-developable photocurable resin composition is short is considered to be due to a thermosetting component added to impart high heat resistance. For example, if a liquid epoxy resin is used as the thermosetting component, the reactivity is improved and the high heat resistance can be remarkably improved, compared with the case of using a solid or powder epoxy resin, but the drying control width is shortened because the hot fogging is easily generated. In addition, in the case where melamine or the like is contained in order to improve high heat resistance, it also becomes easy to generate hot fogging. However, as described above, according to the present invention, an alkali-developable photocurable resin composition having excellent drying control width can be obtained.

When the curable resin composition of the present invention is an alkali-developable photocurable resin composition, the drying control margin is excellent even when a liquid thermosetting component, particularly a liquid epoxy resin, which has a problem of being likely to generate hot fogging, is blended.

Further, by blending (C) the boric acid ester compound, the adhesion of the cured product to the copper circuit of the printed wiring board can be improved.

The components contained in the curable resin composition of the present invention will be described in detail below.

[ (A) carboxyl group-containing resin ]

The carboxyl group of the carboxyl group-containing resin enables a thermosetting reaction with the thermosetting component (B). In addition, alkaline development is also possible by the carboxyl group. From the viewpoint of photocurability and development resistance, it is preferable that the resin has an ethylenically unsaturated bond in the molecule in addition to the carboxyl group, but only a carboxyl group-containing resin having no ethylenically unsaturated double bond may be used. As the ethylenically unsaturated double bond, ethylenically unsaturated double bonds derived from acrylic acid or methacrylic acid or their derivatives are preferred.

In the curable resin composition of the present invention, the carboxyl group-containing resin (a) preferably has at least one of a phenol novolac (novolac) type, a bisphenol novolac type, and a cresol novolac type structure from the viewpoint of heat resistance. In addition, the carboxyl group-containing resin (a) preferably has a phenol novolac type structure from the viewpoint of adhesion of the underfill material in addition to solder heat resistance, and can be suitably used for a printed wiring board for mounting using an underfill material, such as wire bonding mounting and flip chip mounting.

Specific examples of the carboxyl group-containing resin include the compounds (both oligomers and polymers) listed below.

(1) A carboxyl group-containing photosensitive resin obtained by reacting a 2-or more-functional polyfunctional epoxy resin with (meth) acrylic acid and adding a hydroxyl group present in a side chain to a dibasic acid anhydride such as phthalic anhydride, tetrahydrophthalic anhydride or hexahydrophthalic anhydride. Here, it is preferable that the 2-functional or higher multifunctional epoxy resin is in a solid state.

(2) A carboxyl group-containing photosensitive resin is obtained by reacting a polyfunctional epoxy resin obtained by further epoxidizing the hydroxyl group of a 2-functional epoxy resin with epichlorohydrin with (meth) acrylic acid and adding the resulting hydroxyl group to a dibasic acid anhydride. Here, it is preferable that the 2-functional epoxy resin is in a solid state.

(3) A carboxyl group-containing photosensitive resin obtained by reacting an epoxy compound having 2 or more epoxy groups in 1 molecule with a compound having at least 1 alcoholic hydroxyl group and 1 phenolic hydroxyl group in 1 molecule and an unsaturated group-containing monocarboxylic acid such as (meth) acrylic acid, and reacting the alcoholic hydroxyl group of the reaction product obtained with a polybasic acid anhydride such as maleic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, adipic anhydride or the like.

(4) A carboxyl group-containing photosensitive resin obtained by reacting a compound having 2 or more phenolic hydroxyl groups in 1 molecule, such as bisphenol a, bisphenol F, bisphenol S, novolak-type phenol resins, polyparahydroxystyrene, condensates of naphthol and aldehydes, or condensates of dihydroxynaphthalene and aldehydes, with an alkylene oxide such as ethylene oxide or propylene oxide, reacting the reaction product obtained by the reaction with the alkylene oxide with an unsaturated group-containing monocarboxylic acid such as (meth) acrylic acid, and reacting the reaction product obtained by the reaction with the monocarboxylic acid with a polybasic acid anhydride.

(5) A carboxyl group-containing photosensitive resin obtained by reacting a compound having 2 or more phenolic hydroxyl groups in 1 molecule with a cyclic carbonate compound such as ethylene carbonate or propylene carbonate, reacting the reaction product obtained by the reaction with the cyclic carbonate compound with a monocarboxylic acid having an unsaturated group, and reacting the reaction product obtained by the reaction with the monocarboxylic acid with a polybasic acid anhydride.

(6) A terminal carboxyl group-containing urethane resin obtained by a polyaddition reaction of a diisocyanate compound such as an aliphatic diisocyanate, a branched aliphatic diisocyanate, an alicyclic diisocyanate, or an aromatic diisocyanate, and a diol compound such as a polycarbonate polyol, a polyether polyol, a polyester polyol, a polyolefin polyol, an acrylic polyol, a bisphenol a alkylene oxide adduct diol, or a compound having a phenolic hydroxyl group and an alcoholic hydroxyl group, wherein the terminal of the urethane resin is reacted with an acid anhydride.

(7) In the synthesis of a carboxyl group-containing urethane resin obtained by addition polymerization of a diisocyanate, a carboxyl group-containing diol compound such as dimethylolpropionic acid or dimethylolbutyric acid, and a diol compound, a carboxyl group-containing urethane resin obtained by adding a compound having 1 hydroxyl group and 1 or more (meth) acryloyl groups in the molecule, such as hydroxyalkyl (meth) acrylate, and acidifying the terminal (meth) acrylate.

(8) In the synthesis of a carboxyl group-containing urethane resin obtained by a polyaddition reaction of a diisocyanate, a carboxyl group-containing diol compound, and a diol compound, a compound having 1 isocyanate group and 1 or more (meth) acryloyl groups in the molecule, such as an equimolar reaction product of isophorone diisocyanate and pentaerythritol triacrylate, is added to acidify the terminal (meth) acrylic group-containing urethane resin.

(9) A carboxyl group-containing photosensitive resin obtained by copolymerizing an unsaturated carboxylic acid such as (meth) acrylic acid with an unsaturated group-containing compound such as styrene, α -methylstyrene, a lower alkyl (meth) acrylate, or isobutylene.

(10) A carboxyl group-containing polyester resin obtained by reacting a polyfunctional oxetane resin with a dicarboxylic acid such as adipic acid, phthalic acid or hexahydrophthalic acid to add the generated primary hydroxyl group to a dibasic acid anhydride.

(11) The carboxyl group-containing photosensitive resin is obtained by adding any of the carboxyl group-containing resins (1) ~ (10) described above to a compound having a cyclic ether group and a (meth) acryloyl group in 1 molecule.

It should be noted that, here, (meth) acrylate is a term generically referring to acrylate, methacrylate and a mixture thereof, which is also directed to the similar expressions hereinafter.

(A) Since the carboxyl group-containing resin has a plurality of carboxyl groups in the side chain of the main chain polymer, it becomes possible to develop by a dilute aqueous alkaline solution.

Further, (A) the acid value of the carboxyl group-containing resin is suitably in the range of 30 ~ 200mg KOH/g, more preferably in the range of 30 ~ 150mg KOH/g, and particularly preferably in the range of 45 ~ 120mg KOH/g. if the acid value of the carboxyl group-containing resin is 30mg KOH/g or more, the alkali development becomes good, and on the other hand, if it is 200mg KOH/g or less, the dissolution of the exposed portion by the developer can be suppressed, so that the line can be suppressed from becoming thinner than necessary, or in some cases, the exposed portion and the unexposed portion can be suppressed from being dissolved and peeled by the developer without distinction, and the resist of a pattern can be drawn well.

The weight average molecular weight Mw (weight average molecular weight in terms of polystyrene) of the carboxyl group-containing resin (a) varies depending on the resin skeleton, for example, when measured by Gel Permeation Chromatography (GPC), but is preferably more than 4,000 and not more than 150,000, and more preferably in the range of 5,000 ~ 100,000,000.

[ (B) Heat-curing component ]

The thermosetting component (B) may be reacted with the carboxyl group-containing resin (a), and examples thereof include epoxy compounds, amino resins, oxetane compounds, isocyanate compounds, and the like. Among them, epoxy compounds are preferable. Examples of the epoxy compound include a 2-functional epoxy resin having 2 epoxy groups in the molecule, a polyfunctional epoxy resin having a plurality of epoxy groups in the molecule, and the like. In addition, the thermosetting component is preferably in a liquid state from the viewpoint of heat resistance.

Examples of the epoxy compound include epoxidized vegetable oils; bisphenol a type epoxy resin; hydroquinone type epoxy resins, bisphenol type epoxy resins, thioether type epoxy resins; brominated epoxy resins; a novolac type epoxy resin; a diphenol novolak-type epoxy resin; bisphenol F type epoxy resins; hydrogenated bisphenol a type epoxy resin; glycidyl amine type epoxy resins; hydantoin type epoxy resins; an alicyclic epoxy resin; trihydroxyphenyl methane type epoxy resin; a bixylenol-type or biphenol-type epoxy resin or a mixture thereof; bisphenol S type epoxy resin; bisphenol a novolac type epoxy resin; tetraphenylethane type epoxy resins; a heterocyclic epoxy resin; diglycidyl phthalate resin; tetraglycidyl xylenol ethane resin; epoxy resins containing naphthyl groups; an epoxy resin having a dicyclopentadiene skeleton; glycidyl methacrylate copolymer epoxy resin; a copolymerized epoxy resin of cyclohexylmaleimide and glycidyl methacrylate; epoxy-modified polybutadiene rubber derivatives, CTBN-modified epoxy resins, and the like, but are not limited thereto. From the viewpoint of reactivity, an epoxy compound having 2 or more functions is preferable.

The epoxy compound may be any of a solid epoxy resin, a semi-solid epoxy resin, and a liquid epoxy resin, but a liquid epoxy resin is preferable. In the present specification, a solid epoxy resin means an epoxy resin that is solid at 40 ℃, a semi-solid epoxy resin means an epoxy resin that is solid at 20 ℃ and liquid at 40 ℃, and a liquid epoxy resin means an epoxy resin that is liquid at 20 ℃. In the present specification, the definition of solid, semi-solid, and liquid states, and the definition of other thermosetting components are also defined as above.

The determination of the liquid state is performed according to the "method for confirming the liquid state" on page 2 of japan province (No. 1) of the year-round of autonomy.

(1) Device for measuring the position of a moving object

A constant-temperature water tank:

a water tank having a depth of 150mm or more and equipped with a stirrer, a heater, a thermometer, and an automatic temperature controller (temperature control can be performed at. + -. 0.1 ℃ C.) was used.

In the determination of the epoxy resin used in the examples described below, a combination of a low-temperature thermostatic water tank (model BU300) manufactured by Yamato scientific co., ltd and an immersion type thermostatic apparatus thermo (model BF500) was used, and about 22 liters of tap water was added to the low-temperature thermostatic water tank (model BU300), and the power supply of the thermo (model BF500) incorporated therein was turned on to set the temperature to a set temperature (20 ℃ or 40 ℃), and the water temperature was finely adjusted to the set temperature ± 0.1 ℃ by the thermo (model BF500), but any apparatus may be used as long as the same adjustment can be performed.

Test tube:

as a test tube, as shown in fig. 1, a liquid state determination test tube 30a and a temperature measurement test tube 30b were used, the liquid state determination test tube 30a being a flat-bottomed cylindrical transparent glass test tube having an inner diameter of 30mm and a height of 120mm, marked with marked lines 31 and 32 at heights of 55mm and 85mm from the tube bottom, respectively, the mouth of the test tube being closed with a rubber stopper 33a, the temperature measurement test tube 30b being of the same size and marked with the same marked line, the mouth of the test tube being closed with a rubber stopper 33b having a hole for inserting and supporting a thermometer at the center, and a thermometer 34 being inserted into the rubber stopper 33 b. Hereinafter, a scale line of a height of 55mm from the bottom of the tube is referred to as "a line", and a scale line of a height of 85mm from the bottom of the tube is referred to as "B line".

As the thermometer 34, a thermometer for measuring the freezing point (SOP-58 scale range 20 ~ 50 ℃ C.) specified in JIS B7410(1982) "Petroleum test glass thermometer" was used, but any thermometer capable of measuring a temperature range of 0 ~ 50 ℃ C. was acceptable.

(2) Experimental procedure

Samples that were left at 20. + -. 5 ℃ under atmospheric pressure for 24 hours or longer were put into the liquid state determination test tube 30a shown in FIG. 1(a) and the temperature measurement test tube 30b shown in FIG. 1(b), respectively, up to line A. The 2 test tubes 30a and 30B were placed upright in a low-temperature constant-temperature water tank so that the line B was below the water surface. The lower end of the thermometer was brought to 30mm below the line A.

After the sample temperature reached the set temperature. + -. 0.1 ℃ this state was maintained for 10 minutes. After 10 minutes, the liquid determination test tube 30a was taken out from the low-temperature constant-temperature water tank, immediately placed horizontally on a horizontal test stand, and the time taken for the tip of the liquid surface in the test tube to move from line a to line B was measured and recorded by a stopwatch. The sample is determined to be liquid when the measurement time is within 90 seconds and is determined to be solid when the measurement time exceeds 90 seconds at the set temperature.

Examples of the solid epoxy resin include naphthalene type epoxy resins such as HP-4700 (naphthalene type epoxy resin) manufactured by DIC, EXA4700 (4-functional naphthalene type epoxy resin) manufactured by DIC, and NC-7000 (polyfunctional solid epoxy resin having a naphthalene skeleton) manufactured by Nippon Chemicals; an epoxide (triphenol epoxy resin) of a condensate of a phenol such as EPPN-502H (triphenol epoxy resin) produced by japan chemical corporation and an aromatic aldehyde having a phenolic hydroxyl group; dicyclopentadiene aralkyl type epoxy resins such as EPICLON HP-7200H (a multifunctional solid epoxy resin having a dicyclopentadiene skeleton) produced by DIC; biphenyl aralkyl type epoxy resins such as NC-3000H (multifunctional solid epoxy resin having a biphenyl skeleton) manufactured by japan chemical company; biphenyl/phenol novolac type epoxy resins such as NC-3000L manufactured by Nippon chemical company; novolac type epoxy resins such as EPICLONN660 and EPICLON 690 manufactured by DIC corporation and EOCN-104S manufactured by Nippon chemical company; biphenyl type epoxy resins such as YX-4000 manufactured by Mitsubishi chemical company; phosphorus-containing epoxy resins such as TX0712 manufactured by new-day iron-on-gold chemical company; tris (2, 3-epoxypropyl) isocyanurate such as TEPIC manufactured by Nissan chemical industries, Ltd.

Examples of the semi-solid epoxy resin include bisphenol A type epoxy resins such as EPICLON 860, EPICLON 900-IM, EPICLON EXA-4816, EPICLON EXA-4822, Araldite AER280 from Asahi チバ, エポトート YD-134 from Dongdu chemical Co., JER834 and JER872 from Mitsubishi chemical corporation, and ELA-134 from Sumitomo chemical industry Co., Ltd; naphthalene type epoxy resins such as EPICLON HP-4032 manufactured by DIC corporation; and phenol novolac type epoxy resins such as EPICLON-740 manufactured by DIC corporation.

Examples of the liquid epoxy resin include bisphenol a type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, phenol novolac type epoxy resin, tert-butyl-catechol type epoxy resin, glycidyl amine type epoxy resin, aminophenol type epoxy resin, and alicyclic epoxy resin.

When the curable resin composition of the present invention is an alkali-developable photocurable resin composition, the amount of the epoxy compound to be added is preferably 1 ~ 100 parts by mass per 100 parts by mass of the carboxyl group-containing resin (a), because if the amount is within the above range, curability is improved, and various general properties such as soldering heat resistance are more favorable, and further because sufficient toughness can be obtained and storage stability is not lowered, and more preferably 2 ~ 70 parts by mass.

When a liquid epoxy resin is used, the ratio of the liquid epoxy resin is preferably 5 ~ 50 parts by mass, and more preferably 5 ~ 40 parts by mass, per 100 parts by mass of the carboxyl group-containing resin (a). when the ratio of the liquid epoxy resin is 5 ~ 50 parts by mass, the heat resistance is more excellent, and when the resin composition is an alkali-developable photocurable resin composition, the developability is excellent.

Examples of the amino resin include melamine resin and benzoguanamine resin. Examples of the compound include methylol melamine compounds, methylolbenzoguanamine compounds, methylolglycoluril compounds, methylolurea compounds, and the like. Further, the alkoxymethylated melamine compound, alkoxymethylated benzoguanamine compound, alkoxymethylated glycoluril compound and alkoxymethylated urea compound can be obtained by converting the methylol group of the methylolmelamine compound, methylolbenzoguanamine compound, methylolglycoluril compound and methylolurea compound into an alkoxymethyl group, respectively. The kind of the alkoxymethyl group is not particularly limited, and examples thereof include a methoxymethyl group, an ethoxymethyl group, a propoxymethyl group, and a butoxymethyl group. Particularly, a melamine derivative having a formalin concentration of 0.2% or less which is friendly to the human body and environment is preferable.

Examples of the oxetane compound include bis [ (3-methyl-3-oxetanylmethoxy) methyl ] ether, bis [ (3-ethyl-3-oxetanylmethoxy) methyl ] ether, 1, 4-bis [ (3-methyl-3-oxetanylmethoxy) methyl ] benzene, 1, 4-bis [ (3-ethyl-3-oxetanylmethoxy) methyl ] benzene, (3-methyl-3-oxetanyl) methyl acrylate, (3-ethyl-3-oxetanyl) methyl acrylate, (3-methyl-3-oxetanyl) methyl methacrylate, (3-ethyl-3-oxetanyl) methyl methacrylate, and mixtures thereof, Examples of the polyfunctional oxetane compound such as an oligomer or a copolymer thereof include an etherate of an oxetanol and a resin having a hydroxyl group such as a novolak resin, poly (p-hydroxystyrene), Cardo-type bisphenol, calixarene, or silsesquioxane. Further, a copolymer of an unsaturated monomer having an oxetane ring and an alkyl (meth) acrylate, and the like can be mentioned.

As the isocyanate compound, a polyisocyanate compound having a plurality of isocyanate groups in a molecule can be used. As the polyisocyanate compound, for example, an aromatic polyisocyanate, an aliphatic polyisocyanate, or an alicyclic polyisocyanate can be used. Specific examples of the aromatic polyisocyanate include 4,4' -diphenylmethane diisocyanate, 2, 4-tolylene diisocyanate, 2, 6-tolylene diisocyanate, naphthalene-1, 5-diisocyanate, o-xylylene diisocyanate, m-xylylene diisocyanate and 2, 4-tolylene diisocyanate dimer. Specific examples of the aliphatic polyisocyanate include tetramethylene diisocyanate, hexamethylene diisocyanate, methylene diisocyanate, trimethylhexamethylene diisocyanate, 4-methylenebis (cyclohexyl isocyanate), and isophorone diisocyanate. Specific examples of the alicyclic polyisocyanate include bicycloheptane triisocyanate. And, an adduct of the above-mentioned isocyanate compound, a biuret product and an isocyanurate product can be mentioned. The isocyanate compound may be a blocked isocyanate compound in which an isocyanate group is temporarily inactivated by being protected with a blocking agent.

As the thermosetting component (B), publicly known and commonly used thermosetting components other than those described above can be used, and maleimide compounds, benzoxazine resins, carbodiimide resins, cyclic carbonate compounds, episulfide resins, and the like can be used. As the thermosetting component (B), imidazole derivatives such as imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 1-cyanoethyl-2-phenylimidazole, and 1- (2-cyanoethyl) -2-ethyl-4-methylimidazole; amine compounds such as dicyanodiamine, benzyldimethylamine, 4- (dimethylamino) -N, N-dimethylbenzylamine, 4-methoxy-N, N-dimethylbenzylamine, and 4-methyl-N, N-dimethylbenzylamine, and hydrazine compounds such as adipic acid dihydrazide and sebacic acid dihydrazide; examples of commercially available products of phosphorus compounds such as triphenylphosphine include, for example, 2MZ-A, 2MZ-OK, 2PHZ, 2P4BHZ, 2P4MHZ (both trade names of imidazole compounds), U-CAT3503N manufactured by San-Apro Ltd, U-CAT3502T (both trade names of blocked isocyanate compounds of dimethylamine), DBU, DBN, U-CATA SA102, and U-CAT5002 (both bicyclic amidine compounds and salts thereof), which are manufactured by chemical industries of four countries. Further, as the (B) thermosetting component, a compound that functions as an adhesion imparting agent, such as an s-triazine derivative, for example, guanamine, acetoguanamine, benzoguanamine, melamine, 2, 4-diamino-6-methacryloyloxyethyl-s-triazine, 2-vinyl-4, 6-diamino-s-triazine, or a seed and isocyanuric acid adduct, may be used. (B) The thermosetting component may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

The thermosetting component (B) preferably contains melamine. Because the melamine is bonded to the (C) borate compound, the combination of the melamine with the (C) borate compound is more effective for extending the drying management breadth.

(B) The amount of the thermosetting component blended is preferably 5 ~ 250 parts by mass, more preferably 10 ~ 230 parts by mass, per 100 parts by mass of the (a) carboxyl group-containing resin, and if the amount of the thermosetting component blended is in the above range, the heat resistance is more excellent, and the strength of the cured coating film is also excellent.

[ (C) Borate Compound ]

As the (C) borate ester compound, a known borate ester compound can be used. For example, triphenyl borate and cyclic borate having low volatility can be given. Cyclic borate ester compounds are preferred. The cyclic borate compound means a compound containing boron in a cyclic structure, and 2,2 '-oxybis (5,5' -dimethyl-1, 3, 2-dioxaborolane) is particularly preferable. Examples of the borate ester compound include, in addition to triphenyl borate and a cyclic borate ester compound, trimethyl borate, triethyl borate, tripropyl borate, tributyl borate, and the like, but these borate ester compounds are highly volatile and therefore may not be sufficiently effective in the storage stability of the composition particularly at high temperatures. The borate ester compound may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

Commercially available products of the borate ester compound (C) include, for example, ハイボロン BC1, ハイボロン BC2, ハイボロン BC3 and ハイボロン BCN (all of which are produced by Boron International co., ltd.), currentl-07N (produced by four nations chemical industry co.).

(C) The amount of the boric acid ester compound is preferably 0.01 ~ 5 parts by mass, more preferably 0.05 ~ 3 parts by mass, per 100 parts by mass of the carboxyl group-containing resin (a).

(photopolymerization initiator)

The curable resin composition of the present invention may contain a photopolymerization initiator. The photopolymerization initiator is not particularly limited, and known and commonly used photopolymerization initiators can be used. Examples thereof include benzoins such as benzoin, benzoin acyl, benzoin methyl ether, benzoin ethyl ether, benzoin n-propyl ether, benzoin isopropyl ether, and benzoin n-butyl ether; benzoin alkyl ethers; benzophenones such as benzophenone, p-methylbenzophenone, Michler's ketone, methylbenzophenone, 4' -dichlorobenzophenone, and 4,4' -bisdiethylaminobenzophenone; acetophenones such as acetophenone, 2-dimethoxy-2-phenylacetophenone, 2-diethoxy-2-phenylacetophenone, 1-dichloroacetophenone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- [4- (methylthio) phenyl ] -2-morpholinyl-1-propanone, 2-benzyl-2-dimethylamino-1- (4-morpholinylphenyl) -butanone-1, and N, N-dimethylaminoacetophenone; thioxanthones such as thioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2, 4-dimethylthioxanthone, 2, 4-diethylthioxanthone, 2-chlorothioxanthone and 2, 4-diisopropylthioxanthone; anthraquinones such as anthraquinone, chloroanthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, 2-amylanthraquinone, and 2-aminoanthraquinone; ketals such as acetophenone dimethyl ketal and benzil dimethyl ketal; benzoic acid esters such as ethyl 4-dimethylaminobenzoate, 2- (dimethylamino) ethyl benzoate, and ethyl p-methylbenzoate; oxime esters such as 1- [4- (phenylthio) phenyl ] -1, 2-octanedione 2- (O-benzoyloxime) and 1- [ 9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl ] -ethanone 1- (O-acetyloxime); titanocenes such as bis (. eta.5-2, 4-cyclopentadien-1-yl) -bis (2, 6-difluoro-3- (1H-pyrrol-1-yl) phenyl) titanium, bis (cyclopentadienyl) -bis [2, 6-difluoro-3- (2- (1H-pyrrol-1-yl) ethyl) phenyl ] titanium, and the like; acylphosphine oxides such as 2,4, 6-trimethylbenzoyldiphenylphosphine oxide and bis (2,4, 6-trimethylbenzoyl) -phenylphosphine oxide; diphenyldisulfide, 2-nitrofluorene, butyroin, anisoin ethyl ether, azobisisobutyronitrile, tetramethylthiuram disulfide, and the like. Among them, acetophenones, thioxanthones, and oxime esters (hereinafter, also referred to as "oxime ester-based photopolymerization initiators") are preferable. The photopolymerization initiator may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

The photopolymerization initiator is preferably added in an amount of 0.01 ~ 20 parts by mass per 100 parts by mass of the carboxyl group-containing resin (a) because if the amount is in the above range, photocurability on copper is sufficient, curability of the coating film becomes good, coating film properties such as chemical resistance are improved, and further deep-part curability is improved, and more preferably 0.5 ~ 15 parts by mass per 100 parts by mass of the carboxyl group-containing resin (a).

Since the sensitivity to light at the time of exposure can be improved, it is preferable to use a thioxanthone (hereinafter, also referred to as "thioxanthone-based photopolymerization initiator") in combination with another photopolymerization initiator, and among the above, it is more preferable to use 2, 4-diethylthioxanthone-based photopolymerization initiator in an amount of 0.05 ~ 2 parts by mass, and still more preferably 0.1 ~ 1 parts by mass, based on 100 parts by mass of the carboxyl group-containing resin (a), because the effect of improving the sensitivity is large if the amount is in the range of 0.05 ~ 2 parts by mass, and as a result, undercut (undercut) is easily suppressed, and further, outgassing is less likely to occur.

The oxime ester photopolymerization initiator is preferably used in an amount of 0.01, 0.01 ~ 5 parts by mass per 100 parts by mass of the carboxyl group-containing resin (a). the reason is that, if the amount is in the above range, photocurability on copper is sufficient, curability of a coating film becomes good, coating film properties such as chemical resistance and the like are improved, deep curability is also improved, furthermore, an oxime ester photopolymerization initiator generates an alkali by light irradiation, thermosetting is improved, and properties of a cured product after thermal curing such as gold plating resistance, solder heat resistance and the like can be further improved, and the amount of the oxime ester photopolymerization initiator is more preferably 0.5, 0.5 ~ 3 parts by mass per 100 parts by mass of the carboxyl group-containing resin (a).

(light-curing component)

The curable resin composition of the present invention may contain a photocurable component. As the photocurable component, a photoreactive monomer is preferably used. The photoreactive monomer is a compound having 1 or more ethylenically unsaturated groups in the molecule. The photoreactive monomer contributes to photocuring of the carboxyl group-containing resin by irradiation with active energy rays.

Examples of the compound that can be used as the photoreactive monomer include publicly known polyester (meth) acrylate, polyether (meth) acrylate, urethane (meth) acrylate, carbonate (meth) acrylate, epoxy (meth) acrylate, and the like. Specific examples thereof include hydroxyalkyl acrylates such as 2-hydroxyethyl acrylate and 2-hydroxypropyl acrylate; diacrylates of glycols such as ethylene glycol, methoxy tetraethylene glycol, polyethylene glycol, propylene glycol, etc.; acrylamides such as N, N-dimethylacrylamide, N-methylolacrylamide, and N, N-dimethylaminopropylacrylamide; aminoalkyl acrylates such as N, N-dimethylaminoethyl acrylate and N, N-dimethylaminopropyl acrylate; polyhydric acrylates such as polyhydric alcohols such as hexanediol, trimethylolpropane, pentaerythritol, dipentaerythritol, and tris-hydroxyethyl isocyanurate, and ethylene oxide adducts, propylene oxide adducts, and epsilon-caprolactone adducts thereof; polyacrylates such as phenoxy acrylate, bisphenol a diacrylate, and ethylene oxide adducts and propylene oxide adducts of these phenols; polyacrylates of glycidyl ethers such as glycerol diglycidyl ether, glycerol triglycidyl ether, trimethylolpropane triglycidyl ether, and triglycidyl isocyanurate; the acrylic ester and the melamine acrylate obtained by directly acrylating a polyol such as a polyether polyol, a polycarbonate diol, a hydroxyl-terminated polybutadiene, or a polyester polyol, or by urethane acrylating via a diisocyanate, and the methacrylic esters corresponding to the above acrylates are also included, without being limited to the above.

Further, as the photoreactive monomer, there may be used an epoxy acrylate resin obtained by reacting a polyfunctional epoxy resin such as a cresol novolak type epoxy resin with acrylic acid, an epoxy urethane acrylate compound obtained by further reacting a 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, and the like. Such an epoxy acrylate resin can improve photocurability without lowering finger-touch drying properties.

The photocurable component may be used alone in 1 kind, or 2 or more kinds in combination, and the amount of the photocurable component is preferably 1 ~ 15 parts by mass per 100 parts by mass of the carboxyl group-containing resin (a) because, if the amount is in the above range, the photocurability is improved, the pattern formation is facilitated by the alkali development after the irradiation with the active energy ray, and the coating film strength is improved, more preferably 1 ~ 10 parts by mass.

(inorganic Filler)

The curable resin composition of the present invention may contain an inorganic filler for the purpose of improving properties such as adhesion, hardness, and heat resistance. Examples of the inorganic filler include calcium carbonate, magnesium carbonate, fly ash (flash), dehydrated sludge, natural silica, synthetic silica, kaolin, clay, calcium oxide, magnesium oxide, titanium oxide, zinc oxide, barium sulfate, calcium hydroxide, aluminum oxide, magnesium hydroxide, talc, mica, hydrotalcite, aluminum silicate, magnesium silicate, calcium silicate, calcined talc, wollastonite, potassium titanate, magnesium sulfate, calcium sulfate, magnesium phosphate, sepiolite, vermiculite (Zonolite), boron nitride, aluminum borate, silica balloon, glass flake, glass balloon, silica, iron-making slag, copper, iron oxide, carbon black, iron-silicon-aluminum (Sendust), alnico, magnetic powder such as various ferrites, cement, glass powder, Nokurg silica, diatomaceous earth, antimony trioxide, magnesium hydroxide sulfate, aluminum hydrate, hydrated gypsum, and the like, A plain sail, etc. Examples of the inorganic filler include fiber-reinforced materials such as organic bentonite, montmorillonite, glass fiber, carbon fiber, and boron nitride fiber. The inorganic filler may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

The average particle diameter (D50) of the inorganic filler is preferably 25 μm or less, more preferably 10 μm or less, and still more preferably 3 μm or less. Here, D50 represents a particle diameter at 50% volume accumulation obtained by a laser diffraction scattering particle size distribution measurement method based on Mie scattering theory. More specifically, the measurement can be performed in the following manner: the particle size distribution of the fine particles was prepared on a volume basis by a laser diffraction scattering particle size distribution measuring apparatus, and the median particle size was defined as an average particle size. For the measurement sample, a sample obtained by dispersing microparticles in water by ultrasound can be preferably used. As the laser diffraction type particle size distribution measuring apparatus, LA-500 manufactured by horiba, Ltd.

From the viewpoint of forming a coating film of the curable resin composition, the amount of the inorganic filler blended is preferably 50 ~ 400 parts by mass, and more preferably 80 ~ 350 parts by mass, per 100 parts by mass of the carboxyl group-containing resin (a).

(organic solvent)

The curable resin composition of the present invention may contain a known and commonly used organic solvent for adjusting the viscosity of the composition and for adjusting the viscosity for the purpose of coating the composition on a substrate or a film. Examples thereof include toluene, xylene, ethyl acetate, butyl acetate, methanol, ethanol, isopropanol, isobutanol, 1-butanol, diacetone alcohol, ethylene glycol monobutyl ether, propylene glycol monoethyl ether, propylene glycol monomethyl ether acetate, terpineol, methyl ethyl ketone, carbitol acetate, butyl carbitol acetate and the like. The organic solvent may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

(other optional ingredients)

The curable resin composition of the present invention may contain known and commonly used additives in the field of electronic materials. Examples of the additives include thermal polymerization inhibitors, ultraviolet absorbers, silane coupling agents, plasticizers, flame retardants, antistatic agents, antiaging agents, antibacterial/seed/mildew-proofing agents, defoaming agents, leveling agents, organic fillers, thickeners, adhesion imparting agents, thixotropy imparting agents, colorants, photoinitiation auxiliaries, and sensitizers.

The curable resin composition of the present invention may be 1 liquid or 2 or more liquids. In the case of 2 or more liquids, for example, the boric acid ester compound (C) may be blended with either the main agent containing the carboxyl group-containing resin (a) or the curing agent containing the thermosetting component (B).

The curable resin composition of the present invention may be in the form of a dry film comprising a film and a resin layer formed on the film and composed of the curable resin composition, and when the film is dried, the film can be obtained by diluting the curable resin composition of the present invention with the organic solvent, adjusting the viscosity to an appropriate level, coating the film on a carrier film (support) to a uniform thickness using a die coater, a blade coater, a lip coater, a bar coater, a squeeze coater, a reverse coater, a roll coater, a gravure coater, a spray coater, or the like, and drying the film at50 ~ 130 ℃ for 1 ~ 30 minutes, usually, the coating film thickness is not particularly limited, but is suitably selected from the range of 10 ~ 150 μm, preferably 20 ~ 60 μm, in terms of the film thickness after drying.

The carrier film may be a plastic film, and preferably a polyester film such as polyethylene terephthalate, a polyimide film, a polyamideimide film, a polypropylene film, a polystyrene film, or the like, and the thickness of the carrier film is not particularly limited, but is usually appropriately selected from the range of 10 ~ 150 μm.

After forming a resin layer on a carrier film using the curable resin composition of the present invention, a releasable cover film is preferably laminated on the surface of the film for the purpose of preventing adhesion of dust to the surface of the film. As the releasable cover film, for example, a polyethylene film, a polytetrafluoroethylene film, a polypropylene film, a surface-treated paper, or the like can be used as long as the adhesion between the film and the cover film is smaller than the adhesion between the film and the carrier film when the cover film is peeled.

The curable resin composition of the present invention can be formed into a non-tacky coating film by, for example, adjusting the viscosity to a viscosity suitable for a coating method with the organic solvent, applying the composition onto a substrate by a method such as dip coating, flow coating, roll coating, bar coating, screen printing, curtain coating, and the like, and volatilizing and drying (predrying) the organic solvent contained in the composition at a temperature of about 60 ~ 100 ℃ to form a dry film.

Examples of the base material include a printed circuit board and a flexible printed circuit board on which a circuit is formed in advance, and a copper clad laminate using all grades (FR-4 and the like) of the following materials: materials such as copper foil laminates for high-frequency circuits and the like using paper phenol resins, paper epoxy resins, glass cloth epoxy resins, glass polyimides, glass cloth/nonwoven fabric epoxy resins, glass cloth/paper epoxy resins, synthetic fiber epoxy resins, fluorine, seeds, and polyoxyphenylenes, seeds, and cyanate esters; further, polyimide films, PET films, glass substrates, ceramic substrates, wafer plates, and the like can be given.

The volatilization drying after the application of the curable resin composition of the present invention can be carried out using a hot air circulation type drying oven, an IR oven, a hot plate, a convection oven, or the like (a method of bringing hot air in a dryer into convection contact using a device equipped with a heat source of a steam-based air heating system, and a method of blowing the support through a nozzle).

The curable resin composition of the present invention is heated to a temperature of about 140 ~ 180 ℃ to be thermally cured, for example, whereby the (a) carboxyl group-containing resin reacts with the (B) thermosetting component, and a cured coating film having excellent properties such as heat resistance, chemical resistance, moisture absorption resistance, adhesion, and electrical properties can be formed.

When the curable resin composition of the present invention is of an alkali development type, a coating film obtained by applying the curable resin composition and volatilizing and drying the solvent is exposed (irradiated with an active energy ray), whereby exposed portions (portions irradiated with the active energy ray) are cured, and further, by a contact type (or non-contact type), the unexposed portions are developed with a dilute aqueous alkaline solution (for example, an aqueous sodium carbonate solution of 0.3 ~ 3 wt%) by selectively exposing with an active energy ray through a photomask having a pattern formed thereon or directly exposing with a laser direct exposure machine, thereby forming a resist pattern.

The exposure machine used for the irradiation with the active energy rays may be any device that is equipped with a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a metal halide lamp, a mercury short arc lamp, or the like and irradiates ultraviolet rays in the range of 350 ~ nm, and further, a direct drawing device (for example, a laser direct imaging device that directly draws an image with a laser beam using CAD data from a computer) may be used²Preferably at 20 ~ 600mJ/cm²Within the range of (1).

The developing method may be carried out by a dipping method, a spraying method, a brushing method, or the like, and an alkaline aqueous solution of potassium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate, ammonia, an amine, or the like may be used as the developer.

The curable resin composition of the present invention is suitable for forming a permanent insulation cured film such as a solder resist, a cover lay layer, and an interlayer insulation layer of a printed wiring board or a flexible printed wiring board.

Examples

The present invention will be described in further detail with reference to examples, but the present invention is not limited to the examples. In the following description, "part" and "%" are based on mass unless otherwise specified.

[ Synthesis and adjustment of carboxyl group-containing resin ]

(A-1: Synthesis of carboxyl group-containing resin having phenol novolak type Structure)

190 parts (1 equivalent) of phenol novolac type epoxy resin (P-201, epoxy equivalent 190g/eq, manufactured by Nippon Chemicals Co., Ltd.), 140.1 parts of carbitol acetate, and 60.3 parts of solvent naphtha were charged into a flask, heated to 90 ℃ and stirred to be dissolved. The resulting solution was cooled to 60 ℃ and 72 parts (1 mol) of acrylic acid, 0.5 part of methylhydroquinone and 2 parts of triphenylphosphine were added thereto, and the mixture was heated to 100 ℃ to react for about 12 hours, whereby a reaction product having an acid value of 0.2mg KOH/g was obtained. 80.6 parts (0.53 mol) of tetrahydrophthalic anhydride was added thereto, and the mixture was heated to 90 ℃ and reacted for about 6 hours to obtain a resin solution having a solid acid value of 60mg KOH/g and a solid concentration of 65.8%. Hereinafter referred to as varnish A-1.

(A-2: Synthesis of carboxyl group-containing resin having a structure of cresol novolak type)

220 parts (1 equivalent) of a cresol novolak type epoxy resin (EOCN-104S, epoxy equivalent 220g/eq, manufactured by Nippon chemical Co., Ltd.), 140.1 parts of carbitol acetate, and 60.3 parts of solvent naphtha were charged into a flask, heated to 90 ℃ and stirred to be dissolved. The resulting solution was cooled to 60 ℃ and 72 parts (1 mol) of acrylic acid, 0.5 part of methylhydroquinone and 2 parts of triphenylphosphine were added thereto, and the mixture was heated to 100 ℃ to react for about 12 hours, whereby a reaction product having an acid value of 0.2mg KOH/g was obtained. 80.6 parts (0.53 mol) of tetrahydrophthalic anhydride was added thereto, and the mixture was heated to 90 ℃ and reacted for about 6 hours to obtain a resin solution having a solid acid value of 85mg KOH/g and a solid concentration of 65.8%. Hereinafter referred to as varnish A-2.

(A-3: preparation of carboxyl group-containing copolymer resin)

As a sample, Cyclomer P (ACA) Z250 (acid value: 70.0mg KOH/g, solid content: 45%) manufactured by Daicel chemical industries, Inc. was used. Hereinafter referred to as varnish A-3.

Example 1 ~ 14 and comparative examples 1 and 2

The above resin solution (varnish) was blended with each component shown in table 1 at the ratio (parts by mass) shown in table 1, and the mixture was premixed by a mixer and kneaded by a three-roll mill to prepare a curable resin composition.

< development Life >

Each of the curable resin compositions of example 1 ~ 11 and comparative examples 1 and 2 was applied to the entire surface of a copper foil substrate formed by patterning by screen printing, and the resultant light meter produced by ORC manual co²The test piece was dried at 80 ℃ for 30 minutes in a manner of irradiating the test piece with 365nm ultraviolet rays, and the amount of the developer was 2kg/cm²The removal state of the unexposed portion after 60 seconds of the spray pressure development of (3) was visually judged.

○ complete development

X: failing to develop.

< gold plating resistance >

Each of the curable resin compositions of example 1 ~ 11 and comparative examples 1 and 2 was applied over the entire surface of a copper foil substrate formed by patterning by screen printing, dried at 80 ℃ for 30 minutes, left to cool to room temperature, and the substrate was exposed to a solder resist pattern at an optimum exposure amount using an exposure apparatus equipped with a high-pressure mercury lamp (short arc lamp), and then exposed to 1wt% Na at 30 ℃₂CO₃The spraying pressure of the aqueous solution was 2kg/cm²And then developed for 60 seconds under the conditions described above to obtain a resist pattern. The substrate was subjected to UV conveyor furnace so that the cumulative exposure amount was 1000mJ/cm²The curing was carried out by irradiating with ultraviolet rays and then heating at 150 ℃ for 60 minutes. To obtainThe printed board (evaluation board) of (1) was plated under conditions of 0.5 μm nickel and 0.03 μm gold using commercially available electroless nickel plating baths and electroless gold plating baths, and the presence or absence of peeling of the resist layer and the presence or absence of plating penetration was evaluated by tape stripping, and then the presence or absence of peeling of the resist layer was evaluated by tape stripping.

Each of the curable resin compositions of example 12 ~ 14 was applied to a copper foil substrate by screen printing over the entire surface thereof, and then cured by heating at 150 ℃ for 60 minutes, and the presence or absence of peeling of the resist layer was evaluated in the same manner as in example 1, except that the printed substrate (evaluation substrate) obtained as described above was used.

The criteria for determination are as follows.

◎ no flaking off

○ there is partial peeling, but within 3

△ existence of exfoliation centered on the edge portion

X: there is swelling, flaking.

< solder Heat resistance >

The curable resin compositions of example 1 ~ 11 and comparative examples 1 and 2 were applied over the entire surface of a substrate by screen printing so that the dried film thickness became 20 μm, dried in a hot air circulation type drying oven at 80 ℃ for 30 minutes, and then left to cool to room temperature, the substrate was exposed at an optimum exposure amount by an exposure apparatus equipped with a high-pressure mercury lamp (an exposure machine equipped with a mercury short arc lamp, ormrnamight co., ltd.) and developed at 30 ℃ and a spray pressure of 0.2MPa for 60 seconds in a developer of 1 mass% aqueous sodium carbonate solution to obtain a pattern, and the substrate was further exposed at a cumulative exposure amount of 1000mJ/cm in a UV transport oven²The curing was carried out by ultraviolet irradiation and then heating at 160 ℃ for 60 minutes. The optimum exposure amount is determined by performing exposure through a stepwise exposure table (steptablet) (T4105C manufactured by Stouffer corporation) at the time of exposure, and setting the number of steps of the stepwise exposure table remaining after development to 8 steps. The obtained printed circuit board (evaluation substrate) was coated with a rosin flux,the solder bath, which had been set to 260 c, was immersed for 30 seconds. The test substrate was cleaned with an organic solvent, and then a peel test with a transparent tape (cellophane adhesive tape) was performed, and the following criteria were used for evaluation.

Each of the curable resin compositions of example 12 ~ 14 was applied to a copper foil substrate by screen printing over the entire surface thereof, and then cured by heating at 150 ℃ for 60 minutes, and a peeling test was performed in the same manner as in example 1 except that the printed substrate (evaluation substrate) obtained as described above was used.

◎ no flaking off

○ partial peeling but 3 or less

△ existence of exfoliation centered on the edge portion

X: there is swelling, flaking.

< insulation resistance >

The curable resin compositions of example 1 ~ 14 and comparative examples 1 and 2 were applied in an IPC comb-type B pattern, cured in the same manner as in the gold plating resistance evaluation described above, humidified at 90% RH, 25 ~ 65 ℃, and DC100V for 7 days, and then observed for an insulation resistance value after 1 minute at DC 500V.

○：10¹²Omega or more

△：10¹¹Omega is more than or equal to 10¹²Ω

X: less than 10¹¹Ω。

< tensile Strength, elongation >

Each of the curable resin compositions of example 1 ~ 11 and comparative examples 1 and 2 was applied over the entire surface of a glossy surface of a copper foil, dried at 80 ℃ for 30 minutes, left to cool to room temperature, and subjected to entire surface exposure at an optimum exposure amount using an exposure apparatus equipped with a high-pressure mercury lamp (short arc lamp), and then the curable resin composition on the copper foil was subjected to cumulative exposure amount of 1000mJ/cm using a UV conveyor oven²The cured product was obtained by irradiating the cured product with ultraviolet rays and then heating the cured product at 150 ℃ for 60 minutes.

On the other hand, each of the curable resin compositions of example 12 ~ 14 was applied over the entire surface of a copper foil to the glossy surface thereof, and cured at 180 ℃ for 90 minutes to obtain a cured product.

The copper foil was removed from each cured product obtained as described above, and the resulting product was cut into test pieces having a width of about 5mm and a length of about 80mm, and the elongation at break was measured using a tensile tester (Autograph AGS-100N, manufactured by Shimadzu corporation).

The measurement conditions were: the sample width was about 10mm, the distance between the fulcrums was about 40mm, the drawing speed was 1.0 mm/min, and the elongation until break was taken as the elongation at the break point.

The tensile strength was evaluated by the following criteria.

◎ is more than 7%

○, more than 5% and less than 7%

△, more than 3% and less than 5%.

< peeling Strength >

Each of the curable resin compositions of example 1 ~ 11 and comparative examples 1 and 2 was applied over the entire surface of a glossy surface of a copper foil which had been subjected to a surface treatment in advance (CZ-8101, manufactured by MEC Co., Ltd., etching amount of about 1.0 μm), dried at 80 ℃ for 30 minutes, left to cool to room temperature, and subjected to full-surface exposure at an optimum exposure amount using an exposure apparatus equipped with a high-pressure mercury lamp (short arc lamp), and then the curable resin composition on the copper foil was subjected to cumulative exposure amount of 1000mJ/cm in a UV conveyor furnace²The cured product was obtained by irradiating the cured product with ultraviolet rays and then heating the cured product at 150 ℃ for 60 minutes.

On the other hand, each of the curable resin compositions of example 12 ~ 14 was applied over the entire surface of a copper foil which had been subjected to a surface treatment (MEC co., ltd., CZ-8101, etching amount of about 1.0 μm) in advance, and cured at 180 ℃ for 60 minutes to prepare a copper foil having a cured film.

After applying an adhesive (Araldite) to the cured film on each copper foil obtained as described above, a copper-clad evaluation substrate was produced by a press under pressure and temperature of 0.5MPa and 60 ℃.

The obtained copper-clad laminate was evaluated by cutting a cut with a size of about 10mm × about 80mm to a depth of the cured film, slightly peeling off the end to secure a nip, nipping the resultant laminate with a nip jig, and measuring the peel strength using a tensile tester (Autograph AGS-100N, manufactured by shimadzu corporation). The measurement conditions were: the tensile rate was set at50 mm/min at room temperature, and the average load at35 mm peeling was measured. The peel strength was evaluated by the following criteria.

◎ greater than 10N

○ is greater than 7N and less than 10N

△, more than 5N and less than 7N.

< tolerance to PCBT >

Each of the cured resin compositions of example 1 ~ 14 and comparative examples 1 and 2 was applied in a comb pattern of L/S100 μm/100 μm with a copper thickness of 18 μm, and the substrate obtained by curing in the same manner as in the evaluation of the plating resistance was placed in an atmosphere in which the temperature in the bath was maintained at 121 ℃ and the humidity was maintained at 97%, DC30V was applied to the substrate, and the resistance value was 10⁶Below Ω, the ligation time was measured as the end point of the measurement.

◎ at a time of over 200 hours

Good: over 150 hours and less than 200 hours

△, more than 100 hours and less than 150 hours

X: less than 100 hours.

< adhesion of underfill >

Using plasma (gas Ar/O)₂And outputting: 350W, vacuum degree: 300 mTorr), an evaluation substrate obtained by electroless gold plating in the above gold plating resistance evaluation was subjected to a 60-second treatment, an underfill material (DENA TITER3003iEX, manufactured by Nagase ChemteX corporation) was applied, curing was performed at 160 ℃ for 1 hour, reflow soldering was further performed 3 times at a peak temperature of 260 ℃, pressure cooking was further performed at 121 ℃ for 100 hours under 2 atmospheres and a humidity of 100%, and then adhesion between the underfill material and the resist layer was measured by a push gauge (push gauge) to evaluate the following criteria.

◎ at a ratio of 100N or more

Good: 80N or more and less than 100N

△ at 60N or more and less than 80N

X: below 60N.

[ Table 1]

*1: photosensitive carboxyl group-containing resin having phenol novolac type skeleton (PN (phenol novolac type epoxy resin)/AA (acrylic acid)/THPA (tetrahydrophthalic anhydride))

*2: photosensitive carboxyl group-containing resin having cresol novolak type skeleton (CN (cresol novolak type epoxy resin)/AA (acrylic acid)/THPA (tetrahydrophthalic anhydride))

*3: carboxyl group-containing copolymer resin (Cyclomer P (ACA) Z250 manufactured by Daicel chemical industries Co., Ltd.)

*4: irgacure 907 (2-methyl-1- [4- (methylthio) phenyl ] -2-morpholinopropan-1-one) manufactured by BASF Japan corporation

*5: DETX-S (2, 4-diethylthioxanthone) manufactured by Nippon Chemicals

*6: irgacure OXE02(1- [ 9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl ] -ethanone 1- (O-acetyloxime))

*7: made by Sakai chemical company as B-30

*8: SO-E2 manufactured by Admatechs

*9: 2,2 '-oxybis (5,5' -dimethyl-1, 3, 2-dioxaborolane)

*10: diethylene glycol monoethyl ether acetate

*11: aromatic hydrocarbon (Solvesso 150)

*12: N-730A (phenol novolac type epoxy resin, liquid epoxy resin) manufactured by DIC corporation

*13: JeR828 (bisphenol A epoxy resin, liquid epoxy resin) manufactured by Mitsubishi chemical company

*14: n-770 (phenol novolac type epoxy resin, solid epoxy resin) manufactured by DIC corporation

*15: 2PHZ (2-phenyl-4, 5-dihydroxymethylimidazole) manufactured by Siguo Kabushiki Kaisha

*16: dipentaerythritol hexaacrylate (Co., Ltd.; product of Kyoeisha chemical Co., Ltd.)

*17: trimethylolpropane triacrylate (manufactured by Nippon Kagaku Co., Ltd.).

From the results shown in table 1, it is understood that the cured product of the curable resin composition of example 1 ~ 14 is excellent in heat resistance and elongation, and that in the case of the composition of example 1 ~ 11, which is an alkali development type photocurable resin composition, good developability is obtained even when the development life is evaluated under the above-described drying conditions, and therefore the drying control margin is excellent, while the cured products of the curable resin compositions of comparative examples 1 and 2, which do not contain the (C) boric acid ester compound, are poor in heat resistance and elongation.

Claims

1. A curable resin composition characterized by comprising:

(A) a carboxyl group-containing resin;

(B) a heat-curable composition; and

(C) a borate ester compound, a salt of a carboxylic acid,

the carboxyl group-containing resin (A) has at least any one of the following:

(1) a carboxyl group-containing photosensitive resin obtained by reacting a 2-or more-functional polyfunctional epoxy resin with (meth) acrylic acid and adding a hydroxyl group present in a side chain to a dibasic acid anhydride,

(2) A carboxyl group-containing photosensitive resin obtained by reacting a polyfunctional epoxy resin obtained by further epoxidizing the hydroxyl group of a 2-functional epoxy resin with epichlorohydrin with (meth) acrylic acid and adding the resulting hydroxyl group to a dibasic acid anhydride,

(3) A carboxyl group-containing photosensitive resin obtained by reacting an epoxy compound having 2 or more epoxy groups in 1 molecule with a compound having at least 1 alcoholic hydroxyl group and 1 phenolic hydroxyl group in 1 molecule and an unsaturated group-containing monocarboxylic acid and reacting the alcoholic hydroxyl group of the reaction product obtained with a polybasic acid anhydride,

(4) A carboxyl group-containing photosensitive resin obtained by reacting a compound having 2 or more phenolic hydroxyl groups in 1 molecule with an alkylene oxide, reacting the reaction product obtained by the reaction with the alkylene oxide with an unsaturated group-containing monocarboxylic acid, and reacting the reaction product obtained by the reaction with the unsaturated group-containing monocarboxylic acid with a polybasic acid anhydride,

(5) A carboxyl group-containing photosensitive resin obtained by reacting a compound having 2 or more phenolic hydroxyl groups in 1 molecule with a cyclic carbonate compound, reacting the reaction product obtained by the reaction with the cyclic carbonate compound with an unsaturated group-containing monocarboxylic acid, and reacting the reaction product obtained by the reaction with the unsaturated group-containing monocarboxylic acid with a polybasic acid anhydride,

(6) A carboxyl-terminated urethane resin obtained by reacting the terminal of a urethane resin obtained by addition polymerization of a diisocyanate compound and a diol compound with an acid anhydride,

(7) In the synthesis of a carboxyl group-containing urethane resin obtained by addition polymerization of a diisocyanate, a carboxyl group-containing diol compound, and a diol compound, a compound having 1 hydroxyl group and 1 or more (meth) acryloyl groups in the molecule is added, and the carboxyl group-containing urethane resin obtained by (meth) acrylating the terminal thereof, a carboxyl group-containing urethane resin obtained by reacting a carboxyl group-containing diol compound with a diisocyanate,

(8) In the synthesis of a carboxyl group-containing urethane resin obtained by addition polymerization of a diisocyanate, a carboxyl group-containing diol compound, and a diol compound, a compound having 1 isocyanate group and 1 or more (meth) acryloyl groups in the molecule is added, and the carboxyl group-containing urethane resin obtained by (meth) acrylating the terminal thereof, a carboxyl group-containing urethane resin obtained by reacting a carboxyl group-containing diol compound with a diisocyanate,

(9) A carboxyl group-containing photosensitive resin obtained by copolymerization of an unsaturated carboxylic acid and an unsaturated group-containing compound,

(10) A carboxyl group-containing polyester resin obtained by reacting a polyfunctional oxetane resin with a dicarboxylic acid and adding the resulting primary hydroxyl group to a dibasic acid anhydride,

(11) A carboxyl group-containing photosensitive resin obtained by adding any one of the carboxyl group-containing resins (1) ~ (10) described above to a compound having a cyclic ether group and a (meth) acryloyl group in 1 molecule.

2. The curable resin composition according to claim 1, wherein a liquid epoxy resin is contained as the (B) thermosetting component.

3. The curable resin composition according to claim 1 or 2, further comprising a photopolymerization initiator.

4. The curable resin composition according to claim 3, wherein the composition is used for forming a solder resist, a cover lay or an interlayer insulating material.

5. A dry film characterized by comprising a resin layer obtained by applying and drying the curable resin composition according to claim 1 ~ 4 on a film.

6. A cured product obtained by curing the curable resin composition according to claim 1 ~ 4 or the resin layer of the dry film according to claim 5.

7. A printed wiring board comprising the cured product according to claim 6.