Resin-coated substrate, resin-coated substrate manufacturing method, printed wiring board, and electronic component device

Abstract

A resin-coated substrate 100 comprising a substrate 20 having an opening 10 and a resin coating 30 covering the substrate 20, the resin coating 30 having a portion 30A that covers the region around the opening 10, and a hanging portion 30B that hangs toward the inside of the opening 10.

Description

Resin-coated substrate, method for manufacturing a resin-coated substrate, printed circuit board, and electronic component device

[0001] This disclosure relates to a resin-coated substrate, a method for manufacturing a resin-coated substrate, a printed circuit board, and an electronic component device.

[0002] The use of glass substrates (hereinafter also referred to as glass substrates) as substrates for printed circuit boards is being considered. When using glass substrates as substrates for printed circuit boards, a crucial issue is how to ensure adhesion between the glass substrate and the conductive circuits formed on its surface. As a measure to improve the adhesion between the glass substrate and the conductive circuits, Patent Document 1 proposes providing a resin layer on the surface of the glass substrate to assist in adhesion to the conductors.

[0003] International Publication No. 2013 / 150940

[0004] Printed circuit board substrates sometimes have openings, such as through-holes. When openings are formed in a glass substrate, it is desirable to coat the inside of the openings with resin. One possible method for efficiently coating the inside of openings with resin is to immerse the substrate with the openings in a resin solution. However, with this method, it is difficult to adhere a sufficient amount of resin solution to the periphery of the openings, making it difficult to form a resin coating with sufficient thickness on the periphery of the openings. In view of the above circumstances, the object of this disclosure is to provide a resin-coated substrate having a resin coating of sufficient thickness on the periphery of the openings, a method for manufacturing this resin-coated substrate, and a printed circuit board and an electronic component device including this resin-coated substrate.

[0005] The following embodiments are included as means for solving the above problems: <1> A resin-coated substrate comprising a substrate having an opening and a resin coating covering the substrate, wherein the resin coating has a portion that covers the area around the opening and a hanging portion that hangs down toward the inside of the opening. <2> The resin-coated substrate according to <1>, wherein the opening includes an opening where the volume V of the hanging portion, the area S of the opening, and the thickness T of the resin coating satisfy the formula: V = ST. <3> The resin-coated substrate according to <1> or <2>, wherein the resin coating is made of a cured product of a resin composition containing a curable resin. <4> A method for manufacturing a resin-coated substrate according to any one of <1> to <3>, comprising: bringing a film-like resin composition into contact with the substrate so as to cover the opening; and deforming the resin composition. <5> The method for manufacturing a resin-coated substrate according to <4>, wherein the deformation of the resin composition is carried out so as to cause the portion of the resin composition that covers the opening to hang down toward the inside of the opening. A printed circuit board including a resin-coated substrate as described in any one of items <6>, <1>, to <3>. An electronic component device including the printed circuit board described in <7>, <6> and an electronic component.

[0006] This disclosure provides a resin-coated substrate having a resin coating of sufficient thickness around the periphery of an opening, a method for manufacturing the resin-coated substrate, and a printed circuit board and an electronic component device including the resin-coated substrate.

[0007] This is a schematic cross-sectional view showing the structure of the resin-coated substrate of the present disclosure. This is a schematic plan view showing the structure of the resin-coated substrate of the present disclosure. These are electron microscope images of the peripheral edges of the apertures in the resin-coated substrates prepared in Example 1 and Comparative Example 1.

[0008] In this disclosure, numerical ranges indicated using "~" include the numbers before and after "~" as the minimum and maximum values, respectively. In numerical ranges described in stages in this disclosure, the upper or lower limit of one numerical range may be replaced by the upper or lower limit of another numerical range described in stages. Also, in numerical ranges described in this disclosure, the upper or lower limit of that range may be replaced by the values ​​shown in the examples. In this disclosure, each component may contain multiple types of the corresponding substance. If multiple types of the substance corresponding to each component are present in the composition, the content or amount of each component means the total content or amount of the multiple types of substances present in the composition, unless otherwise specified. In this disclosure, the term "layer" includes cases where the layer is formed over the entire region when the region in which the layer exists is observed, as well as cases where the layer is formed over only a part of the region.

[0009] In this disclosure, "solid component" means a component other than a volatile component such as a solvent. Components that do not volatilize even if they are in a liquid state and remain in the cured product are considered solid components.

[0010] In this disclosure, "semi-cured product" is synonymous with a resin composition in the B-stage state as defined in JIS K 6800 (2006), and "cured product" is synonymous with a resin composition in the C-stage state as defined in JIS K 6800 (2006).

[0011] The mechanisms of action described in this disclosure are speculative and do not limit the mechanisms by which the effects of this disclosure are achieved. Furthermore, embodiments of this disclosure include any combination of the matters described herein.

[0012] [Resin-coated substrate] The resin-coated substrate of the present disclosure comprises a substrate having an opening and a resin coating covering the substrate, wherein the resin coating has a portion that covers the area around the opening and a hanging portion that hangs down toward the inside of the opening.

[0013] The resin-coated substrate of this disclosure will be described with reference to the drawings. The configurations shown in the drawings are conceptual and do not limit the actual configuration of the resin-coated substrate. Figure 1 is a schematic cross-sectional view showing the configuration of the resin-coated substrate of this disclosure. Figure 2 is a schematic plan view showing the configuration of the resin-coated substrate of this disclosure. Specifically, in the resin-coated substrate shown in Figure 1, the side of the substrate that is covered with the resin coating is shown.

[0014] As shown in Figure 1, the resin-coated substrate 100 comprises a substrate 20 having an opening 10 and a resin coating 30 covering the substrate 20. The resin coating 30 has a portion 30A that covers the area 20A surrounding the opening 10 and a hanging portion 30B that hangs down toward the inside of the opening 10. The resin coating 30 is in a continuous state with the portion 30A that covers the area 20A surrounding the opening 10 and the hanging portion 30. Therefore, the peripheral edge of the opening 10 is covered with a resin coating 30 of sufficient thickness. When a resin coating 30 of sufficient thickness is formed on the peripheral edge of the opening 10, for example, sufficient adhesion of a conductor (not shown) on the peripheral edge of the opening 10 to the resin-coated substrate 100 is ensured. In this disclosure, "periphery of the opening 10" means the portion of the surface of the substrate 20 covered by the resin coating 30 shown in Figure 2 that corresponds to the area surrounding the opening 10 (the portion enclosed by the dotted line in Figure 2).

[0015] In the resin-coated substrate 100, the diameter of the opening 10 is not particularly limited and can be selected according to the application of the resin-coated substrate 100. For example, the diameter of the opening 10 may be in the range of 10 μm to 1000 μm. In this disclosure, the diameter of the opening 10 is defined as the diameter measured on the surface of the substrate 20 that is covered with the resin coating 30.

[0016] In the resin-coated substrate 100, the thickness of the resin coating 30 is not particularly limited and can be selected according to the application of the resin-coated substrate 100. For example, the thickness of the resin coating 30 may be in the range of 0.1 μm to 50 μm. In this disclosure, the thickness of the resin coating 30 is defined as the thickness of the portion 30A that covers the area around the opening 10 (if the thickness is not constant, the maximum value of the thickness).

[0017] The hanging portion 30B of the resin coating 30 covers the side wall 10A of the opening 10. The hanging portion 30B may directly or indirectly cover the side wall 10A of the opening 10. An example of the case where the hanging portion 30B of the resin coating 30 indirectly covers the side wall 10A of the opening 10 is when the side wall 10A of the opening 10 is covered with a second resin coating (not shown). When the side wall 10A of the opening 10 is covered with the second resin coating, adhesion to the conductor inside the opening 10 can be more reliably ensured.

[0018] The opening 10 may include an opening 10 where the volume V of the hanging portion 30B, the area S of the opening 10, and the thickness T of the resin coating 30 satisfy the formula: V = ST. In the above formula, the volume V of the hanging portion 30B is defined as the volume of the portion on the opening 10 side of the boundary between the surface of the substrate 20 and the opening 10 (the portion shown by the shaded area in Figures 1 and 2). In the above formula, the area S of the opening 10 is defined as the area of ​​the opening 10 measured on the side of the substrate 20 that is covered by the resin coating 30. In the above formula, the thickness T of the resin coating 30 is defined as the thickness of the portion 30A that covers the area around the opening 10.

[0019] A resin-coated substrate 100 having an opening 10 that satisfies the above formula can be obtained, for example, by a resin-coated substrate manufacturing method described later. That is, it can be obtained by bringing a film-like resin composition into contact with the substrate 20 so as to cover the opening 10 formed in the substrate 20, and then deforming the portion of the film-like resin composition covering the opening 10 to form a hanging portion 30B.

[0020] When there are multiple openings 10 in the resin-coated substrate 100, all of the multiple openings 10 may satisfy the formula V = ST, or some of the multiple openings 10 may satisfy the formula V = ST, and the other openings 10 may not satisfy the formula V = ST (they satisfy formula V > ST or formula V < ST). For example, the proportion of the multiple openings 10 that satisfy the formula V = ST may be 50% or more, 70% or more, 80% or more, or 100% based on the number. An example of an opening 10 that satisfies the formula V > ST is an opening in which a part of the portion 30A covering the area around the opening 10 is deformed and forms a drooping portion 30B. From the viewpoint of ensuring sufficient thickness of the resin coating at the periphery of the opening, it is preferable that V satisfying the formula V > ST is 1.5 times or less of ST, and more preferably 1.2 times or less. An example of an opening 10 that satisfies the formula: V < ST is an opening in which a hanging portion 30B is formed from a film-like resin composition that has holes (for example, tears when peeling from the support) in the portion covering the opening 10. From the viewpoint of ensuring sufficient volume of the hanging portion, it is preferable that V satisfying V < ST is 0.5 times or more ST, and more preferably 0.7 times or more.

[0021] In the resin-coated substrate 100 shown in Figures 1 and 2, the opening 10 penetrates the substrate 20, but the disclosure is not limited thereto. That is, the opening provided in the substrate may penetrate the substrate or not. In the resin-coated substrate 100 shown in Figures 1 and 2, the shape of the opening 10 is circular, but the disclosure is not limited thereto. That is, the shape of the opening provided in the substrate may be circular or not. In the resin-coated substrate 100 shown in Figures 1 and 2, the diameter of the opening 10 in the depth direction is constant (i.e., the opening is cylindrical), but the disclosure is not limited thereto. That is, the diameter of the opening provided in the substrate in the depth direction may be constant or not.

[0022] In the resin-coated substrate of this disclosure, the type of substrate is not particularly limited and includes glass substrates, glass epoxy substrates, metal substrates, silicon substrates, ceramic substrates, silicon carbide substrates, polyester substrates, polyimide substrates, BT resin (bismaleimide-triazine resin) substrates, thermosetting polyphenylene ether substrates, etc. From the viewpoint of exhibiting the effect of improving the adhesion between the substrate and the conductor by resin coating, a glass substrate is preferred as the substrate.

[0023] In this disclosure, "glass substrate" means a substrate made solely of glass. Therefore, a substrate made of glass and a dissimilar material, such as a prepreg made by impregnating glass cloth with resin, does not qualify as a "glass substrate." Examples of materials for glass substrates include alkali-free glass, soda glass, borosilicate glass, aluminosilicate glass, and quartz glass. A glass substrate may have parts made of materials other than glass, such as wiring and through electrodes. In this case, the resin coating may be in contact with the parts made of materials other than glass.

[0024] The thickness of the substrate may be 30 μm to 2 mm, 50 μm to 1.5 mm, or 100 μm to 1 mm, from the viewpoint of mechanical strength and thinning of the printed circuit board.

[0025] The material of the resin coating is not particularly limited and can be selected according to the application of the resin-coated substrate. The components contained in the first coating and the second coating may be the same or different. From the viewpoint of heat resistance, mechanical strength, etc., the resin coating is preferably made of a cured product of a resin composition containing a curable resin, more preferably made of a cured product of a resin composition containing a thermosetting resin or a photocurable resin, and even more preferably made of a cured product of a resin composition containing a thermosetting resin. In this disclosure, "curable resin" means a compound that forms a crosslinked structure by stimuli such as heating or light irradiation, "thermosetting resin" means a compound that forms a crosslinked structure by heating, and "photocurable resin" means a compound that forms a crosslinked structure by light irradiation. The curable resin may be cured by self-polymerization or by reaction with a curing agent, crosslinking agent, etc. The resin composition may contain only one type of resin or two or more types.

[0026] Examples of thermosetting resins include epoxy resins, cyanate resins, maleimide compounds, bismaleimides, addition polymers of bismaleimides and diamines, phenolic resins, polyphenylene ether resins, bismaleimide resins, resol resins, benzoxazine resins, oxetane resins, isocyanate resins, amino resins, unsaturated polyester resins, allyl resins, dicyclopentadiene resins, silicone resins, triazine resins, and melamine resins.

[0027] As a photocurable resin, any compound having a functional group that undergoes a polymerization reaction upon light irradiation (photopolymerizable functional group) can be used without particular limitation. Examples of photopolymerizable functional groups include radical polymerizable functional groups and polymerizable functional groups other than radical polymerizable functional groups. Examples of radical polymerizable functional groups include (meth)acryloyl groups, vinyl groups, allyl groups, styryl groups, alkenyl groups, alkenylene groups, maleimide groups, etc. Examples of photopolymerizable functional groups other than radical polymerizable functional groups include epoxy groups such as glycidyl groups, alicyclic epoxy groups such as epoxycyclohexylmethyl groups, and oxetanyl groups such as ethyloxetanylmethyl groups. The photocurable resin may be used in combination with a photopolymerization initiator. Examples of photopolymerization initiators include initiators that generate radicals upon light irradiation, initiators that generate cations (acids) upon light irradiation, and initiators that generate anions (bases) upon light irradiation. The photocurable resin may be curable with visible light or with ultraviolet light.

[0028] From the viewpoint of heat resistance, mechanical strength, adhesive strength, etc., the resin coating is preferably made of a cured product of a resin composition containing a thermosetting resin, and more preferably made of a cured product of a resin composition containing an epoxy resin.

[0029] The type of epoxy resin is not particularly limited and can be selected according to the use of the resin composition and the like. It can be classified into glycidyl ether type epoxy resin, glycidyl amine type epoxy resin, glycidyl ester type epoxy resin, etc. Among these, glycidyl ether type epoxy resin is preferred. From the perspective of molecular structure, as the epoxy resin, bisphenol type epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin; alicyclic epoxy resins such as dicyclopentadiene type epoxy resin; aliphatic chain epoxy resins; novolac type epoxy resins such as phenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol A novolac type epoxy resin, bisphenol F novolac type epoxy resin, phenol aralkyl novolac type epoxy resin, biphenyl aralkyl novolac type epoxy resin; stilbene type epoxy resin; naphthalene skeleton-containing type epoxy resins such as naphthol novolac type epoxy resin, naphthol aralkyl type epoxy resin; biphenyl aralkyl type epoxy resin; xylylene type epoxy resin; dihydroanthracene type epoxy resin and the like can be mentioned.

[0030] From the perspectives of the heat resistance, mechanical strength, etc. of the cured product, it is preferable that the resin composition contains an epoxy resin having a biphenyl-diyl group. In the present disclosure, the "biphenyl-diyl group" means a divalent group obtained by removing two hydrogen atoms out of the hydrogen atoms directly bonded to the two aromatic rings constituting biphenyl. The two aromatic rings constituting biphenyl may have substituents or may not have substituents. Specifically, as the biphenyl-diyl group, biphenyl-2,3'-diyl group, biphenyl-2,4'-diyl group, biphenyl-3,4'-diyl group, biphenyl-4,4'-diyl group and the like can be mentioned. Among these, biphenyl-4,4'-diyl group is preferred. The epoxy resin having a biphenyl-diyl group may be a compound having one or more biphenyl-diyl groups in the molecule and having two or more epoxy groups.

[0031] Examples of the epoxy resin having a biphenyl-diyl group include a biphenyl aralkyl type epoxy resin, and biphenyl type epoxy resins such as biphenol diglycidyl ether and tetramethylbiphenol diglycidyl ether. Among these, from the viewpoint of adhesiveness to a conductor, a biphenyl aralkyl type epoxy resin is preferable.

[0032] The biphenyl aralkyl type epoxy resin may be a compound containing a structure represented by the following general formula (A-1).

[0033]

[0034] (In the formula, R Ａ１ is an aliphatic hydrocarbon group having 1 to 5 carbon atoms or a halogen atom, and n Ａ１ is an integer of 0 to 3.)

[0035] Examples of the aliphatic hydrocarbon group having 1 to 5 carbon atoms represented by R Ａ１ in the general formula (A-1) include alkyl groups having 1 to 5 carbon atoms such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, and an n-pentyl group; alkenyl groups having 2 to 5 carbon atoms; alkynyl groups having 2 to 5 carbon atoms and the like. The aliphatic hydrocarbon group having 1 to 5 carbon atoms may be either linear or branched. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like. N Ａ１ in the general formula (A-1) may be an integer of 0 to 2, or may be 0. When n Ａ１ is an integer of 2 or more, a plurality of R Ａ１ may be the same as or different from each other.

[0036] The epoxy resin containing the structure represented by the general formula (A-1) may be an epoxy resin represented by the following general formula (A-2).

[0037]

[0038] (In the formula, R Ａ１ and n Ａ１ are the same as those in the general formula (A-1), and n Ａ２ is an integer of 1 to 10.)

[0039] In the above general formula (A-2), multiple R Ａ１ n, either one or multiple n Ａ１ These terms may be the same or different. n in the general formula (A-2) above Ａ２ This can be an integer from 1 to 10, an integer from 1 to 7, or an integer from 1 to 5.

[0040] From the viewpoint of imparting appropriate flexibility to the cured product, the resin composition may include an epoxy resin having alkylene groups with 3 or more carbon atoms as the epoxy resin.

[0041] An epoxy resin having an alkylene group with three or more carbon atoms may also be an epoxy resin having an alkylene group with three or more carbon atoms and two or more epoxy groups. The number of carbon atoms in the alkylene group having three or more carbon atoms in an epoxy resin having an alkylene group with three or more carbon atoms may be 3 to 10, 4 to 9, or 5 to 8, from the viewpoint of adhesion to conductors and heat resistance.

[0042] The alkylene group having three or more carbon atoms in the epoxy resin may be derived from an alkylene glycol having three or more carbon atoms. Examples of alkylene glycols having three or more carbon atoms include 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, and 1,8-octanediol. The epoxy resin having three or more carbon atoms may be an aliphatic epoxy resin in which two glycidyl ether groups are bonded to the alkylene group having three or more carbon atoms, or an aromatic epoxy resin in which two glycidyl ether groups are bonded to an aromatic ring.

[0043] Examples of epoxy resins having alkylene groups with three or more carbon atoms include compounds represented by the following general formula (C-1) and compounds represented by the following general formula (C-2).

[0044]

[0045] (In the formula, X ＣEach of these is a residue obtained by independently removing two phenolic hydroxyl groups from a polyfunctional phenol compound, Y Ｃ This is a residue obtained by removing two hydroxyl groups from an alkylene glycol having 3 or more carbon atoms, n Ｃ１ n is an integer from 1 to 5. Ｃ２ (This is an integer between 1 and 5.)

[0046]

[0047] (In the formula, Y Ｃ This is a residue obtained by removing two hydroxyl groups from an alkylene glycol having 3 or more carbon atoms, n Ｃ３ (This is an integer between 1 and 15.)

[0048] Examples of the above-mentioned polyfunctional phenol compounds include bisphenol resins such as bisphenol A, bisphenol F, and bisphenol S; novolac resins such as phenol novolac, cresol novolac, bisphenol novolac, and bisphenol F novolac; and catechol and dihydroxynaphthalene.

[0049] The functional group equivalent of a thermosetting resin (epoxy equivalent in the case of epoxy resin) may be 50 g / eq to 5,000 g / eq, 70 g / eq to 3,000 g / eq, 80 g / eq to 2,000 g / eq, 100 g / eq to 1,000 g / eq, 150 g / eq to 700 g / eq, or 200 g / eq to 600 g / eq, from the viewpoint of adhesion to conductors. The functional group equivalent of a thermosetting resin can be measured according to the method specified in JIS K 0070:1992.

[0050] The epoxy equivalent of the epoxy resin having a biphenyl-diyl group may be 150 g / eq to 400 g / eq, 200 g / eq to 350 g / eq, or 270 g / eq to 320 g / eq, from the viewpoint of adhesion to conductors.

[0051] The epoxy equivalent of the epoxy resin having an alkylene group with 3 or more carbon atoms may be 250 g / eq to 900 g / eq, 300 g / eq to 600 g / eq, or 350 g / eq to 550 g / eq, from the viewpoint of adhesion to conductors.

[0052] The epoxy resin content in the resin composition is preferably 10% to 80% by mass, more preferably 15% to 75% by mass, even more preferably 20% to 70% by mass, and particularly preferably 25% to 65% by mass, based on the total amount of resin components in the resin composition (100% by mass).

[0053] The resin composition may include a curing agent as a thermosetting resin. For example, the resin composition may include an epoxy resin as a thermosetting resin and a curing agent for the epoxy resin.

[0054] Examples of curing agents for epoxy resins include ester curing agents, phenol curing agents, amine curing agents, acid anhydride curing agents, polymer captan curing agents, polyaminoamide curing agents, isocyanate curing agents, blocked isocyanate curing agents, benzoxazine curing agents, and carbodiimide curing agents.

[0055] Ester curing agents are preferred as curing agents for epoxy resins. Ester curing agents refer to compounds having one or more ester groups that can react with epoxy groups, and are sometimes called active ester curing agents.

[0056] When a phenol curing agent or amine curing agent is used as a curing agent for epoxy resin, secondary hydroxyl groups are generated as the epoxy group opens. In contrast, when an ester curing agent is used as a curing agent for epoxy resin, secondary hydroxyl groups are not generated, and a cured product with a low dielectric constant can be obtained. Furthermore, when the surface of the cured product formed by the reaction of epoxy resin and ester curing agent is subjected to modification treatments such as ultraviolet irradiation, ozone treatment, or plasma treatment, oxygen-containing groups are generated on the surface of the cured product due to molecular cleavage. These oxygen-containing groups act to enhance the adhesion to conductors.

[0057] Examples of ester curing agents include phenol ester compounds, thiophenol ester compounds, N-hydroxyamine ester compounds, and ester compounds of heterocyclic hydroxy compounds. Among these, phenol ester compounds are preferred.

[0058] The ester curing agent is preferably a compound having two or more ester groups in one molecule, and more preferably a compound having two or more ester groups in one molecule, wherein the two or more ester groups are formed from a polycarboxylic acid compound and a compound having a phenolic hydroxyl group. The ester group formed from a polycarboxylic acid compound and a compound having a phenolic hydroxyl group is an ester group formed by an esterification reaction (condensation reaction) between the carboxyl group of the polycarboxylic acid compound and the phenolic hydroxyl group of the compound having a phenolic hydroxyl group.

[0059] Examples of polycarboxylic acid compounds include compounds having two or more aliphatic carboxyl groups and compounds having two or more aromatic carboxyl groups. Examples of compounds having two or more aliphatic carboxyl groups include succinic acid, maleic acid, and itaconic acid. Examples of compounds having two or more aromatic carboxyl groups include benzenedicarboxylic acids such as phthalic acid, isophthalic acid, and terephthalic acid; benzenetricarboxylic acids such as trimesic acid; and benzenetetracarboxylic acids such as pyromellitic acid. Among these, from the viewpoint of heat resistance and dielectric properties, compounds having two or more aromatic carboxyl groups may be used, or benzenedicarboxylic acids may be used. Polycarboxylic acid compounds may be used individually or in combination of two or more.

[0060] Compounds having phenolic hydroxyl groups include compounds having one phenolic hydroxyl group, compounds having two phenolic hydroxyl groups, and compounds having three or more phenolic hydroxyl groups. Compounds having one phenolic hydroxyl group include monophenol compounds such as phenol, o-cresol, m-cresol, and p-cresol; mononaphthol compounds such as α-naphthol and β-naphthol; and hydroxybenzophenone. Compounds having two phenolic hydroxyl groups include dihydroxybenzene compounds such as hydroquinone, resorcinol, and catechol; bisphenol compounds such as bisphenol A, bisphenol F, bisphenol S, methylated bisphenol A, methylated bisphenol F, and methylated bisphenol S; dihydroxynaphthalene compounds such as 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, and 2,6-dihydroxynaphthalene; and phenolphthalein and dicyclopentadiene-type phenolic resins having two phenolic hydroxyl groups. Compounds having three or more phenolic hydroxyl groups include trihydroxybenzophenone, benzenetriol, tetrahydroxybenzophenone, phenol novolac resin, and phenol aralkyl resin. A single compound with phenolic hydroxyl groups may be used, or two or more may be used in combination.

[0061] The ester curing agent having an ester group formed from a polycarboxylic acid compound and a compound having a phenolic hydroxyl group may be a compound represented by the following general formula (B-1).

[0062]

[0063] (In the formula, X Ｂ These are, independently, residues of a polycarboxylic acid compound with two carboxyl groups removed, Y Ｂ These are residues that, independently, remove two phenolic hydroxyl groups from a compound that has two phenolic hydroxyl groups. Ｂ Each of these is independently a residue from which one phenolic hydroxyl group has been removed from a compound having one or two phenolic hydroxyl groups. Ｂ１ (This is an integer between 0 and 10.)

[0064] n in the above general formula (B-1) Ｂ１ This can be an integer between 0 and 5, an integer between 0 and 4, or an integer between 0 and 3.

[0065] The functional group equivalent of the curing agent (ester equivalent in the case of an ester curing agent) may be 100 g / eq to 1000 g / eq, 100 g / eq to 300 g / eq, 150 g / eq to 270 g / eq, or 200 g / eq to 250 g / eq, from the viewpoint of adhesion to the conductor. The functional group equivalent of the curing agent can be measured according to the method specified in JIS K 0070:1992.

[0066] The content of the ester-based curing agent in the resin composition is preferably 5% to 80% by mass, more preferably 10% to 60% by mass, and even more preferably 15% to 50% by mass, based on the total amount of resin components (100% by mass) in the resin composition. When the content of the ester-based curing agent is within the above range, curability and adhesion to conductors tend to improve.

[0067] The content of thermosetting resin in the resin composition is not particularly limited. From the viewpoint of the curing reactivity of the resin composition, the content of thermosetting resin is preferably 30% by mass or more, more preferably 40% by mass or more, and even more preferably 45% by mass or more, based on the total solid content of the resin composition. From the viewpoint of the durability of adhesion to conductors, the content of thermosetting resin is preferably 90% by mass or less, more preferably 80% by mass or less, and even more preferably 75% by mass or less, based on the total solid content of the resin composition.

[0068] When the resin composition includes an epoxy resin as a thermosetting resin and a curing agent for the epoxy resin, the mass ratio of the epoxy resin to the curing agent is not particularly limited. For example, the mass ratio of the epoxy resin to the curing agent may be set so that the equivalent ratio [epoxy groups / functional groups] of epoxy groups derived from the epoxy resin and functional groups derived from the curing agent is a desired value. From the viewpoint of curing reactivity and adhesion to conductors, the above equivalent ratio is preferably 0.5 to 2.0, more preferably 0.75 to 1.75, and even more preferably 1.0 to 1.5.

[0069] (Acrylic Polymer) The resin composition may contain an acrylic polymer. When the resin composition contains an acrylic polymer, it tends to have superior durability in terms of adhesion to the substrate. The acrylic polymer contained in the resin composition may be one type or two or more types. In this disclosure, "acrylic polymer" means a polymer of monomers having an ethylenically unsaturated group, wherein 50% by mass or more of the total monomers are compounds having a (meth)acryloyl group. In this disclosure, "(meth)acryloyl group-containing compound" means a compound having an acryloyl group or a methacryloyl group. In addition to compounds having a (meth)acryloyl group, the acrylic polymer may also contain compounds that do not fall under the category of compounds having a (meth)acryloyl group, such as styrene and vinyl acetate, as polymerization components. The polymerization components of the acrylic polymer may be one type or two or more types.

[0070] From the viewpoint of improving adhesion to the substrate, the polymerization component of the acrylic polymer preferably contains a (meth)acrylic acid ester, and more preferably contains a (meth)acrylic acid ester represented by the following general formula (D-1).

[0071]

[0072] In the formula, R Ａ１ R represents a hydrogen atom or a methyl group. Ａ２ R represents a monovalent hydrocarbon group. Ａ２ The monovalent hydrocarbon group represented by may or may not have substituents.

[0073] R Ａ２ Examples of monovalent hydrocarbon groups represented by R include alkyl groups, aryl groups, and aralkyl groups. Ａ２ The number of carbon atoms in the alkyl group represented by is preferably 1 to 20, more preferably 1 to 15, and even more preferably 2 to 10. Examples of alkyl groups include methyl, ethyl, propyl, butyl, 2-ethylhexyl, cycloalkyl groups, and cycloalkyl-substituted alkyl groups. Examples of cycloalkyl groups include cyclohexyl, norbornyl, tricyclodecanyl, isobornyl, and adamantyl groups. Ａ２ The number of carbon atoms in the aryl group represented by is preferably 6 to 13, and more preferably 6 to 10. Examples of aryl groups include phenyl groups and nonylphenyl groups. Ａ２ The number of carbon atoms in the aralkyl group represented by is preferably 7 to 15, and more preferably 7 to 11. Examples of aralkyl groups include benzyl groups and 4-methylbenzyl groups. Ａ２ When the monovalent hydrocarbon group represented by has substituents, examples of substituents include hydroxyl groups, halogen atoms, oxygen-containing hydrocarbon groups, nitrogen-containing cyclic groups, and the like.

[0074] Specific examples of (meth)acrylic acid esters include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isobutyl (meth)acrylate, ethylene glycol methyl ether (meth)acrylate, cyclohexyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, isobornyl (meth)acrylate, tricyclo[5.2.1.0(2,6)]deca-8-yl (meth)acrylate, isodecyl (meth)acrylate, octadecyl (meth)acrylate, lauryl (meth)acrylate, allyl (meth)acrylate, norbornyl methyl (meth)acrylate, tricyclodecylethyl (meth)acrylate, phenyl (meth)acrylate, nonylphenyl (meth)acrylate, benzyl (meth)acrylate, 4-methylbenzyl (meth)acrylate, and the like.

[0075] The polymerization components of the acrylic polymer may include monomers having functional groups that can react with thermosetting resins (hereinafter also referred to as reactive functional groups). Examples of reactive functional groups include carboxyl groups, epoxy groups (glycidyl groups), hydroxyl groups, amino groups, amide groups, nitrile groups, acid anhydride groups, and vinyl groups. Among these, epoxy groups are preferred from the viewpoint of low hygroscopicity and solder heat resistance.

[0076] Examples of monomers having reactive functional groups include monomers having carboxyl groups such as acrylic acid and methacrylic acid; monomers having epoxy groups such as glycidyl acrylate and glycidyl methacrylate; monomers having hydroxyl groups such as hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, and hydroxypropyl methacrylate; monomers having amino groups such as dimethylaminoethyl acrylate and dimethylaminoethyl methacrylate; monomers having amide groups such as acrylamide, methacrylamide, dimethylacrylamide, and dimethylmethacrylamide; monomers having nitrile groups such as acrylonitrile; and monomers having substituents containing acid anhydride groups such as trimellitic anhydride (meth)acryloyloxyethyl ester and cyclohexanetricarboxylic acid anhydride (meth)acryloyloxyethyl ester.

[0077] The polymerization components of the acrylic polymer may include monomers other than those mentioned above. Examples of other monomers include (meth)acrylic acid N-vinylpyrrolidone, N-(meth)acryloylmorpholine, aromatic vinyl compounds such as styrene, vinyl acetate, and N-substituted maleimide compounds.

[0078] From the viewpoint of improving the durability of adhesion to the substrate, it is preferable that the proportion of (meth)acrylic acid ester in the polymerization component of the acrylic polymer be 70% by mass or more, 80% by mass or more, or 90% by mass or more. The proportion of (meth)acrylic acid ester in the polymerization component of the acrylic polymer may be 100% by mass or less, 99.5% by mass or less, or 97% by mass or less.

[0079] The weight-average molecular weight (Mw) of the acrylic polymer contained in the resin composition is not particularly limited. From the viewpoint of durability of the adhesive strength to the substrate, it is preferable that the weight-average molecular weight of the acrylic polymer is 100,000 to 1,500,000.

[0080] In this disclosure, the weight-average molecular weight of the acrylic polymer is measured in polystyrene equivalent by gel permeation chromatography (GPC). The GPC measurement conditions are as follows. Instrument: High-speed GPC instrument HLC-8320GPC Detector: UV absorbance detector UV-8320 [Tosoh Corporation] Column: Guard column; TSK Guardcolumn SuperHZ-L + Column; TSKgel SuperHZM-N + TSKgel SuperHZM-M + TSKgel SuperH-RC (all manufactured by Tosoh Corporation, product names) Column size: 4.6 × 20 mm (guard column), 4.6 × 150 mm (column), 6.0 × 150 mm (reference column) Eluent: Tetrahydrofuran Sample concentration: 10 mg / 5 mL Injection volume: 25 μL Flow rate: 1.00 mL / min Measurement temperature: 40°C Calibration curve: Standard polystyrene: TSKstandard The equation is approximated using a cubic equation with POLYSTYRENE (Type; A-2500, A-5000, F-1, F-2, F-4, F-10, F-20, F-40) (manufactured by Tosoh Corporation, product name).

[0081] The glass transition temperature (Tg) of the acrylic polymer is not particularly limited. From the viewpoint of durability of adhesion to the substrate, the Tg of the acrylic polymer is preferably 30°C or lower, more preferably 20°C or lower, even more preferably 10°C or lower, and particularly preferably 5°C or lower. From the viewpoint of balancing the properties of the cured product, the Tg of the acrylic polymer is preferably -20°C or higher, more preferably -10°C or higher, and even more preferably -5°C or higher. In this disclosure, the Tg of the acrylic polymer is the value measured using a differential scanning calorimetry (DSC). Specifically, the inflection point of the DSC curve obtained under the following conditions is defined as the Tg of the acrylic polymer. Measurement atmosphere: Nitrogen Sample amount: 10 mg Heating rate: 10°C / min

[0082] The Tg of an acrylic polymer can be adjusted by the combination of monomers used as polymerization components. For example, the Tg of an acrylic polymer can be lowered by increasing the proportion of monomers with relatively low Tg (e.g., Tg of 30°C or less) in the polymerization components. In this disclosure, the Tg of a monomer refers to the Tg of a polymer obtained solely from that monomer. Specific examples of monomers with a Tg of 30°C or less include ethyl acrylate (-22°C), n-butyl acrylate (-54°C), n-butyl methacrylate (20°C), 2-ethylhexyl acrylate (-70°C), 2-ethylhexyl methacrylate (-10°C), n-octyl acrylate (-65°C), lauryl acrylate (-3°C), lauryl methacrylate (-65°C), benzyl acrylate (6°C), phenoxyethyl acrylate (-22°C), 2-methoxyethyl acrylate (-50°C), 2-hydroxyethyl acrylate (-15°C), 4-hydroxybutyl acrylate (-80°C), dimethylaminoethyl methacrylate (18°C), vinyl acetate (30°C), and the like.

[0083] The acrylic polymer may have functional groups (reactive functional groups) that can react with the curable resin. When the resin composition contains an acrylic polymer with reactive functional groups, the durability of the adhesive strength of the cured product to the substrate tends to be superior. The acrylic polymer may also have reactive functional groups in its side chains.

[0084] Acrylic polymers having reactive functional groups can be obtained, for example, by polymerizing a polymerization component containing a monomer having a reactive functional group. When the resin composition contains both an acrylic polymer and an epoxy resin, the reactive functional group is preferably selected from epoxy groups (glycidyl groups), amino groups, carboxyl groups, hydroxyl groups, acid anhydride groups, and amide groups, with epoxy groups being more preferred.

[0085] The functional group equivalent (epoxy equivalent in the case of epoxy groups) of an acrylic polymer having reactive functional groups is not particularly limited. For example, it may be selected from the range of 250 g / eq to 20,000 g / eq. In this disclosure, the functional group equivalent of the acrylic polymer can be measured according to the method specified in JIS K 0070:1992.

[0086] The content of acrylic polymer in the resin composition is not particularly limited. From the viewpoint of durability of adhesion to the substrate, the acrylic polymer content is preferably 10% by mass or more, more preferably 20% by mass or more, and even more preferably 25% by mass or more, based on the total solid content of the resin composition. From the viewpoint of curing reactivity of the resin composition, the acrylic polymer content is preferably 80% by mass or less, more preferably 60% by mass or less, and even more preferably 50% by mass or less, based on the total solid content of the resin composition.

[0087] (Curing accelerator) The resin composition may contain a curing accelerator. When the resin composition contains a curing accelerator, the curing reactivity is improved, and the dielectric properties, heat resistance, and adhesion to conductors of the cured product tend to be better. The resin composition may contain one type of curing accelerator or two or more types.

[0088] Examples of curing accelerators include acidic catalysts such as p-toluenesulfonic acid; amine compounds such as triethylamine, tributylamine, pyridine, and dicyandiamide; imidazole compounds such as methylimidazole, phenylimidazole, 2-undecylimidazole, 1-cyanoethyl-2-phenylimidazole, and 1-cyanoethyl-2-phenylimidazolium trimellitate; isocyanate-masquimidazole compounds such as the addition reaction product of hexamethylene diisocyanate resin and 2-ethyl-4-methylimidazole; quaternary ammonium compounds; phosphorus compounds such as triphenylphosphine and quaternary phosphonium compounds which are the addition reaction products of p-benzoquinone and tri-n-butylphosphine; Examples include organic peroxides such as dicumyl peroxide, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexyn-3, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane, t-butylperoxyisopropyl monocarbonate, and α,α'-bis(t-butylperoxy)diisopropylbenzene; inorganic peroxides such as potassium persulfate, sodium persulfate, and ammonium persulfate; azo compounds such as 2,2'-azobisisobutyronitrile, 2,2'-azobis(2,4-dimethylvaleronitrile), and 2,2'-azobis(4-methoxy-2'-dimethylvaleronitrile); carboxylates of manganese, cobalt, zinc, etc.; and acidic catalysts such as p-toluenesulfonic acid. Among these, imidazole compounds and phosphorus compounds are preferred.

[0089] If the resin composition contains a curing accelerator, the content of the curing accelerator is not particularly limited. From the viewpoint of the curing reactivity of the resin composition, the content of the curing accelerator may be 0.01 to 10 parts by mass, 0.1 to 7 parts by mass, or 0.5 to 5 parts by mass per 100 parts by mass of curable resin.

[0090] (Other Components) The resin composition may contain components other than the curable resin and curing accelerator (also referred to as other components) as needed. Specific examples of other components include elastomers, acrylic polymers, coupling agents, inorganic fillers, flame retardants, antioxidants, heat stabilizers, antistatic agents, ultraviolet absorbers, pigments, colorants, lubricants, ion trapping agents, leveling agents, polymer resin particles, organic solvents, etc.

[0091] Examples of inorganic fillers include silica, alumina, titanium oxide, mica, beryllium, barium titanate, potassium titanate, strontium titanate, calcium titanate, aluminum carbonate, magnesium hydroxide, aluminum silicate, calcium carbonate, calcium silicate, magnesium silicate, silicon nitride, boron nitride, clay, talc, aluminum borate, and silicon carbide.

[0092] (Organic solvents) Resin compositions may contain organic solvents for ease of handling. Examples of organic solvents include alcoholic solvents such as methanol, ethanol, propanol, butanol, methyl cellosolve, butyl cellosolve, and propylene glycol monomethyl ether; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ether solvents such as tetrahydrofuran; aromatic hydrocarbon solvents such as toluene, xylene, and mesitylene; nitrogen atom-containing solvents such as dimethylformamide, dimethylacetamide, and N-methylpyrrolidone; sulfur atom-containing solvents such as dimethyl sulfoxide; and ester solvents such as γ-butyrolactone.

[0093] When a resin composition contains an organic solvent, the amount of organic solvent is not particularly limited and can be set according to the form of use of the resin composition, the desired viscosity of the resin composition, etc.

[0094] Resin compositions can be manufactured by mixing each component in a known manner. In this process, each component may be dissolved or dispersed while being stirred. The mixing order, temperature, time, and other conditions are not particularly limited and can be arbitrarily set according to the type of raw materials, etc.

[0095] The resin composition may be in an uncured state (A-stage) or a semi-cured state (B-stage).

[0096] The melt viscosity of the resin composition is preferably 0.1 Pa·s to 10,000 Pa·s, more preferably 0.5 Pa·s to 5,000 Pa·s, and even more preferably 1 Pa·s to 3,000 Pa·s. In this disclosure, the melt viscosity of the resin composition is measured using a rheometer under the following conditions. Specifically, the rheometer is the "DHR-20" (manufactured by TA Instruments). Measurement range: 50°C to 200°C Heating rate: 3°C / min Test piece: A 20 mm diameter circular tablet made by compressing the resin composition Load: 0.5 N

[0097] [Method for manufacturing a resin-coated substrate] The method for manufacturing a resin-coated substrate according to the present disclosure is the method for manufacturing a resin-coated substrate according to the present disclosure as described above, and includes bringing a film-like resin composition into contact with the substrate so as to cover the openings of the substrate, and deforming the portion of the resin composition that covers the openings of the substrate.

[0098] According to the method of this disclosure, a resin coating having sufficient thickness can be formed on the periphery of the opening.

[0099] In the method of this disclosure, a method for deforming the portion of the resin composition that covers the opening of the substrate is to heat the resin composition to a temperature at which it melts or softens. The step of deforming the resin composition is preferably carried out so that the portion of the resin composition that covers the opening hangs down toward the inside of the opening.

[0100] A film-like resin composition can be produced, for example, by applying a varnish-like resin composition, whose viscosity has been adjusted by adding an organic solvent, to a support and then heating and drying it. Examples of support materials include plastic films such as polyethylene terephthalate (PET) film, metal foil, and release paper. The temperature and time for heating and drying after applying the resin composition to the support can be, for example, 50°C to 200°C and 1 minute to 30 minutes. The thickness of the film-like resin composition is not particularly limited and can be selected according to the desired thickness of the resin coating. The thickness of the film-like resin composition may be, for example, 0.1 μm to 50 μm, 0.5 μm to 30 μm, or 1 μm to 20 μm.

[0101] The method for bringing a film-like resin composition into contact with a substrate so as to cover the openings in the substrate is not particularly limited. For example, one method is to use a laminator or the like to attach the film-like resin composition to the surface of the substrate where the openings are formed.

[0102] When curing a film-like resin composition that has deformed to hang down toward the inside of an opening, the curing conditions are not particularly limited and can be set according to the components of the resin composition. The heating temperature when curing the resin composition may be, for example, 120°C to 250°C, 140°C to 220°C, or 160°C to 200°C. The heating time when curing the resin composition may be, for example, 5 minutes to 180 minutes, 10 minutes to 150 minutes, or 30 minutes to 120 minutes.

[0103] The film-like resin composition preferably contains a thermosetting resin. If the resin composition contains an epoxy resin and an ester curing agent as the thermosetting resin, at least one surface modification treatment selected from the group consisting of ultraviolet irradiation, ozone treatment, and plasma treatment may be applied to the surface of the cured product of the resin composition. By applying a surface modification treatment to the surface of the cured product, oxygen-containing groups can be generated on the surface of the cured product, thereby further enhancing the adhesion to the conductor.

[0104] The method of this disclosure may further include coating the inside of the opening with the resin composition before or after contacting the film-like resin composition with the substrate. By coating the inside of the opening with the resin composition, a resin coating can be formed even on portions not covered by the hanging portion of the resin coating formed from the film-like resin composition. The method of coating the inside of the opening with the resin composition is not particularly limited. From the viewpoint of workability, the method of coating the inside of the opening with the resin composition is preferably a method of immersing the substrate having the opening in a varnish-like resin composition. When coating the inside of the opening with the resin composition, the components contained in the resin composition are not particularly limited and may be the same as or different from the components contained in the film-like resin composition.

[0105] The method of this disclosure may further include arranging a conductor on the surface of the resin coating. The method of arranging the conductor on the surface of the resin coating is not particularly limited. Considering the heat resistance of the resin coating, it is preferable to arrange the conductor by a plating method. As the plating method, known wet plating methods such as electroless plating and electrolytic plating can be applied.

[0106] The material of the conductor is not particularly limited as long as it has the desired electrical conductivity, and can be selected from copper, gold, silver, nickel, platinum, molybdenum, ruthenium, aluminum, tungsten, iron, titanium, chromium, or alloys containing at least one of these metallic elements. The conductor may be formed in layers or may have a desired pattern such as a circuit. Patterned conductors can be formed by known methods such as subtractive, fully additive, semi-additive, and modified semi-additive methods.

[0107] [Printed Wiring Boards and Electronic Component Devices] The printed wiring board of this disclosure includes the resin-coated substrate of this disclosure as described above. In the printed wiring board of this disclosure, a resin coating with excellent adhesion to conductors is placed between the substrate and the conductors. For this reason, the printed wiring board of this disclosure is highly reliable. The electronic component device of this disclosure includes the printed wiring board of this disclosure as described above and electronic components. The electronic component device of this disclosure can be manufactured, for example, by mounting electronic components such as semiconductor elements and memory on the printed wiring board of this disclosure by known methods.

[0108] Embodiments of this disclosure will be specifically described below with reference to examples. However, this disclosure is not limited to these embodiments.

[0109] (Example 1) The following components (parts by mass, equivalent to solid content) were mixed with cyclohexanone to prepare a varnish-like resin composition (solid content concentration: 65% by mass). The varnish-like resin composition was applied to the release layer of a PET film having a release layer to form a resin composition layer. The resin composition layer was heated (140°C, 3 minutes) and dried to produce a B-stage resin film on the PET film as a support. The thickness of the resin film was 3 μm.

[0110] Biphenyl aralkyl epoxy resin (100 parts by mass): Manufactured by Nippon Kayaku Co., Ltd., product name "NC-3000H", epoxy equivalent: 288 g / eq Ester-based curing agent (120 parts by mass): Active ester compound containing a dicyclopentadiene-type diphenol structure (Manufactured by DIC Corporation, product name "HPC-8000L-65MT", ester equivalent: 223 g / eq) Alkylene group-containing epoxy resin (140 parts by mass): Bifunctional aromatic epoxy resin having alkylene groups with 3 or more carbon atoms Curing accelerator (4 parts by mass): Imidazole-based curing accelerator (Manufactured by Shikoku Chemicals Co., Ltd., product name "Cureazole 2PZ")

[0111] A glass substrate with a cylindrical through-hole (diameter: 100 μm) formed as an opening was immersed in a varnish-like resin composition to adhere the resin composition to the surface of the glass substrate. The resin composition was then heated (180°C, 1 hour) to cure it. Next, a resin film was attached to one side of the glass substrate using a vacuum laminator (temperature: 120°C, vacuum time: 20 seconds, pressure: 0.1 MPa, pressurization time: 10 seconds). The PET film was then peeled off from the resin film, and the resin film was heated (180°C, 1 hour) to cure it. During heating, the portion of the resin film covering the opening deformed so that it sagged inward towards the opening. Through the above steps, the resin-coated substrate of Example 1 was manufactured.

[0112] (Example 2) The following components (parts by mass, equivalent to solid content) were mixed with cyclohexanone to prepare a varnish-like resin composition (solid content concentration: 65% by mass). The varnish-like resin composition was applied to the release layer of a PET film having a release layer to form a resin composition layer. The resin composition layer was heated (140°C, 3 minutes) and dried to produce a B-stage resin film on the PET film as a support. The thickness of the resin film was 3 μm.

[0113] Biphenyl aralkyl epoxy resin (100 parts by mass): Manufactured by Nippon Kayaku Co., Ltd., trade name "NC-3000H", epoxy equivalent: 288 g / eq Alkylene group-containing epoxy resin (145 parts by mass): Bifunctional aromatic epoxy resin having alkylene groups with 3 or more carbon atoms Ester-based curing agent (130 parts by mass): Active ester compound containing a dicyclopentadiene-type diphenol structure (Manufactured by DIC Corporation, trade name "HPC-8000L-65MT", ester equivalent: 223 g / eq) Acrylic polymer (380 parts by mass): Acrylic polymer containing epoxy groups in its side chains (Mw: 600,000 to 800,000, epoxy equivalent: approximately 3000 g / eq, Tg: -5°C) Curing accelerator (2.0 parts by mass): Phosphorus-based curing accelerator Coupling agent (0.5 parts by mass): 3-aminopropyltriethoxysilane

[0114] A glass substrate with a cylindrical through-hole (diameter: 100 μm) formed as an opening was immersed in a varnish-like resin composition to adhere the resin composition to the surface of the glass substrate. The resin composition was then heated (180°C, 1 hour) to cure it. Next, a resin film was attached to one side of the glass substrate using a vacuum laminator (temperature: 120°C, vacuum time: 20 seconds, pressure: 0.1 MPa, pressurization time: 10 seconds). The PET film was then peeled off from the resin film, and the resin film was heated (180°C, 1 hour) to cure it. During heating, the portion of the resin film covering the opening deformed so that it sagged inward towards the opening. Through the above steps, the resin-coated substrate of Example 2 was manufactured.

[0115] (Comparative Example 1) The glass substrate before the resin film was attached in Example 1 was used as the resin-coated substrate of Comparative Example 1.

[0116] (Observation of the Periphery of the Aperture) The periphery of the through-holes in the resin-coated substrates prepared in Example 1, Example 2, and Comparative Example 1 was observed using an electron microscope. In the resin-coated substrates of Example 1 and Example 2, the periphery of the through-holes was covered with a resin coating of sufficient thickness. In the resin-coated substrate of Comparative Example 1, the periphery of the through-holes was not covered with a resin coating of sufficient thickness. Figure 3 shows electron microscope images of the periphery of the through-holes in the resin-coated substrates prepared in Example 1 and Comparative Example 1.

[0117] The disclosure of international application PCT / JP2024 / 041350 is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards described herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard were specifically and individually noted to be incorporated by reference.

Claims

1. A resin-coated substrate comprising a substrate having an opening and a resin coating covering the substrate, wherein the resin coating has a portion that covers the area around the opening and a portion that hangs down toward the inside of the opening.

2. The resin-coated substrate according to claim 1, wherein the opening includes an opening where the volume V of the hanging portion, the area S of the opening, and the thickness T of the resin coating satisfy the formula: V = ST.

3. The resin-coated substrate according to claim 1, wherein the resin coating is made of a cured product of a resin composition containing a curable resin.

4. A method for manufacturing a resin-coated substrate according to any one of claims 1 to 3, comprising: bringing a film-like resin composition into contact with the substrate so as to cover the opening; and deforming the resin composition.

5. The method for manufacturing a resin-coated substrate according to claim 4, wherein the deformation of the resin composition is carried out such that the portion of the resin composition covering the opening hangs down toward the inside of the opening.

6. A printed circuit board comprising a resin-coated substrate according to any one of claims 1 to 3.

7. An electronic component device comprising a printed circuit board according to claim 6 and an electronic component.

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