Insulating resin composition, cured product thereof, and electronic component

Abstract

The present invention addresses the problem of providing an insulating resin composition suitable for an aerosol jet printing technique. Provided is an insulating resin composition containing (A) inorganic particles having an average particle diameter (D50) of 0.02-0.5 [mu] m, (B) a polyfunctional thermosetting compound, and (C) a curing agent, the insulating resin composition having a viscosity of 400 mPa.s or less as measured using an E-type viscometer at 25 DEG C and 50 rpm.

Description

Technical Field

[0001] The present invention relates to an insulating resin composition, a cured product thereof, and an electronic component including the cured product. Background Art

[0002] Printed electronics, which directly prints a conductive resin composition and an insulating resin composition onto an object based on digital data to form a circuit, a battery, various sensors, or an insulating pattern, is one of the fields attracting much attention in recent years. One of the printing techniques that has been used for a long time as a representative printing technique of printed electronics is an inkjet printing technique. The piezoelectric inkjet printing technique is a technique in which pressure is applied to ink in a nozzle by a minute nozzle having a diameter of about 20 to 50 μm to eject droplets.

[0003] The size of droplets ejected from an inkjet head is droplets having a diameter of 10 to 100 μm. Therefore, the minimum line width that can be achieved is 30 μm or more, and there is a limit to the line width. In addition, since the printing gap between the nozzle surface and the printing object is narrow, it is suitable for printing on a two-dimensional plane, but there are problems in the case of being used for printing on a three-dimensional curved surface.

[0004] In recent years, as a technique for overcoming the problems of the inkjet printing technique, an aerosol jet printing technique has attracted attention. The aerosol jet printing technique is a technique in which an aerosol generated is ejected in a mist form from a minute nozzle using a gas (for example, refer to Patent Document 1). In the aerosol jet printing technique, minute droplets having a diameter of 10 μm or less are produced, transported to a spray part (nozzle) using a gas, and the opening and closing (On-Off) of ejection from the nozzle to a substrate is digitally controlled, whereby a fine pattern having a minimum line width of 10 μm, for example, can be formed. In addition, in this aerosol jet printing technique, the distance between the substrate and the nozzle during printing is wide, and printing can be performed even with a printing gap of about 5 mm. Therefore, printing can also be performed on a substrate having irregularities of about several mm or a three-dimensional curved surface.

[0005] In Patent Document 2, as an inkjet insulating resin composition that can be coated by an inkjet method, can maintain the shape after coating, and can reduce the generation of voids after curing, the following inkjet resin composition is disclosed, which contains a monoacrylate having a viscosity of less than 3 mPa·s at room temperature and a filler having a maximum particle size of less than 3 μm.

[0006] Prior Art Documents

[0007] Patent Documents

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 2011-502741

[0009] Patent Document 2: Japanese Patent Application Laid-Open No. 2018-117002 Summary of the Invention

[0010] Problems to be Solved by the Invention

[0011] In aerosol jet printing technology, since the material to be ejected needs to be aerosolized, it is required to form fine droplets with a diameter of 10 μm or less. However, when attempting to apply a conventional curable resin composition such as the inkjet insulating resin composition described in Patent Document 2 to aerosol jet printing technology, it has been found that fine droplets cannot be formed or the ejection property is poor, making it unsuitable for aerosol jet printing technology.

[0012] An object of the present invention is to provide an insulating resin composition suitable for aerosol jet printing technology.

[0013] The specific means for solving the above problems are as described below.

[0014] The first embodiment of the present invention is the following insulating resin composition.

[0015] (1) An insulating resin composition comprising (A) inorganic particles having an average particle diameter (D50) of 0.02 to 0.5 μm;

[0016] (B) a polyfunctional thermosetting compound; and

[0017] (C) a curing agent,

[0018] The viscosity of the above insulating resin composition measured using an E-type viscometer under the conditions of 25°C and 50 rpm is 400 mPa·s or less.

[0019] (2) The insulating resin composition according to (1) above, wherein the above (A) inorganic particles have been surface-treated with a (meth)acrylic acid-based surface treatment agent.

[0020] (3) The insulating resin composition according to (1) or (2) above, wherein (B) the polyfunctional thermosetting compound contains a bifunctional thermosetting compound.

[0021] (4) The insulating resin composition according to any one of (1) to (3) above, which further comprises (D) a monofunctional reactive diluent.

[0022] (5) The insulating resin composition according to (4) above, wherein the content of (D) the monofunctional reactive diluent is 40 to 80 parts by mass relative to a total of 100 parts by mass of (B) the polyfunctional thermosetting compound, (C) the curing agent, and (D) the monofunctional reactive diluent.

[0023] (6) The insulating resin composition according to any one of (1) to (5) above, wherein the content of the above-mentioned (A) inorganic particles is 15 to 50 parts by mass with respect to 100 parts by mass of the resin composition.

[0024] (7) The insulating resin composition according to any one of (1) to (6) above, which substantially does not contain particles having a particle size greater than 1.0 μm.

[0025] (8) The insulating resin composition according to any one of (1) to (7) above, which is used for aerosol jet printing.

[0026] (9) The insulating resin composition according to any one of (1) to (7) above, which is used for inkjet printing.

[0027] The second embodiment of the present invention is (10) a cured product obtained by curing the insulating resin composition according to any one of (1) to (9) above.

[0028] The third embodiment of the present invention is (11) an electronic component containing the cured product described in (10) above.

[0029] The embodiments of the present invention also include printing methods and uses in the following aspects.

[0030] (12) An aerosol jet printing method, which includes a step of aerosol jet printing the insulating resin composition according to any one of (1) to (9) above on an object to be printed.

[0031] (13) An inkjet printing method, which includes a step of inkjet printing the insulating resin composition according to any one of (1) to (9) above on an object to be printed.

[0032] (14) Use of the insulating resin composition according to any one of (1) to (9) above in aerosol jet printing.

[0033] (15) Use of the insulating resin composition according to any one of (1) to (9) above in inkjet printing.

[0034] Effects of the Invention

[0035] According to the first embodiment of the present invention, an insulating resin composition suitable for aerosol jet printing technology can be obtained. The insulating resin composition of this first embodiment is also suitable for inkjet printing technology. In addition, according to the second embodiment of the present invention, a cured product of the insulating resin composition coated by aerosol jet printing or inkjet printing can be obtained. Furthermore, according to the third embodiment of the present invention, an electronic component containing such a cured product can be obtained. Detailed Embodiments

[0036] In this specification, in accordance with the convention in the field of synthetic resins, for the components constituting the curable resin composition before curing, even if the component is not a polymer, for example, in the case of a prepolymer compound before curing, the name of the term "resin" that usually means a polymer (especially a synthetic polymer) is sometimes used.

[0037] [Insulating resin composition]

[0038] The insulating resin composition according to the first embodiment of the present invention contains:

[0039] (A)Inorganic particles having an average particle size (D50) of 0.02 to 0.5 μm;

[0040] (B)A polyfunctional thermosetting compound; and

[0041] (C)A curing agent,

[0042] The viscosity of the above insulating resin composition measured using an E-type viscometer under the conditions of 25 °C and 50 rpm is 400 mPa·s or less. According to this embodiment, an insulating resin composition suitable for aerosol jet printing technology can be obtained.

[0043] (A)Inorganic particles having an average particle size (D50) of 0.02 to 0.5 μm

[0044] The insulating composition of this embodiment contains (A) inorganic particles having an average particle size (D50) of 0.02 to 0.5 μm (hereinafter, also referred to as "(A) inorganic particles" or "component (A)"). Component (A) functions as a filler, can maintain an appropriate elastic modulus of the cured product obtained by curing the resin composition, and reduce the linear expansion coefficient of the cured product. Examples of the inorganic particles include insulating inorganic particles such as silica, alumina, and magnesia, but are not limited to these. In this embodiment, the inorganic particles are preferably silica particles.

[0045] In this specification, the average particle size (D50) refers to the particle size (D50) of 50% of the cumulative value of all inorganic particles, and the particle size distribution can be measured by the Microtrac method (laser diffraction scattering method) and calculated based on the results of the particle size distribution measurement.

[0046] In the present embodiment, (A) the inorganic particles are more preferably surface-treated with a (meth)acrylic acid-based surface treatment agent. In aerosol jet printing technology, since the mechanism is to generate fine droplets (aerosols) with a diameter of 1 to 5 μm and transfer them to the nozzle via a gas, the particle size of the inorganic particles is required to be smaller than that of the fine droplets. However, if the particle size of the inorganic particles is reduced, the viscosity of the resin composition increases, resulting in problems such as inability to aerosolize or inability to be ejected from the nozzle. By including inorganic particles that have been surface-treated with a (meth)acrylic acid-based surface treatment agent, even if the particle size of the inorganic particles is small, the viscosity of the resin composition measured using an E-type viscometer at 25°C and 50 rpm can be reduced to 400 mPa·s or less.

[0047] The surface treatment agent has two or more different functional groups in the molecule, one of which is a functional group that chemically bonds to the inorganic material, and the other is a functional group that chemically bonds to the organic material. As examples of the surface treatment agent, depending on the type of the functional group that chemically bonds to the inorganic material, silane-based surface treatment agents, aluminum-based surface treatment agents, titanium-based surface treatment agents, etc. can be cited, but are not limited to these. When the inorganic particles are silica, a silane-based surface treatment agent is preferably used.

[0048] The (meth)acrylic acid-based surface treatment agent has an acryloyl group or a methacryloyl group as a functional group that chemically bonds to the organic material.

[0049] As specific examples of the methacrylic acid-silane-based surface treatment agent, 3-methacryloyloxypropyltrimethoxysilane (for example, as a commercially available product, it is KBM503 manufactured by Shin-Etsu Chemical Co., Ltd.), 3-methacryloyloxypropylmethyldimethoxysilane (for example, as a commercially available product, it is KBM502 manufactured by Shin-Etsu Chemical Co., Ltd.), 3-methacryloyloxypropylmethyldiethoxysilane (for example, as a commercially available product, it is KBE502 manufactured by Shin-Etsu Chemical Co., Ltd.), 3-methacryloyloxypropyltriethoxysilane (for example, as a commercially available product, it is KBE503 manufactured by Shin-Etsu Chemical Co., Ltd.), etc. can be cited, but are not limited to these.

[0050] As specific examples of the acrylic acid-silane-based surface treatment agent, 3-acryloyloxypropyltrimethoxysilane (for example, as a commercially available product, it is KBM-5103 manufactured by Shin-Etsu Chemical Co., Ltd.), etc. can be cited, but are not limited to these.

[0051] Any one kind of the (meth)acrylic acid-based surface treatment agent can be used, or two or more kinds can be used in combination.

[0052] From the viewpoints of coatability and dispersibility of the resin, the average particle diameter (D50) of the inorganic particles (A) is 0.02 to 0.5 μm, preferably 0.03 to 0.4 μm, and more preferably 0.04 to 0.3 μm.

[0053] In the present embodiment, from the viewpoints of viscosity adjustment of the resin composition and suppression of curing shrinkage of the cured product, the content of the inorganic particles (A) is preferably 10 to 60 parts by mass, and more preferably 15 to 50 parts by mass with respect to 100 parts by mass of the resin composition.

[0054] The insulating resin composition of the present embodiment preferably substantially does not contain particles having a particle diameter greater than 1.0 μm. It should be noted that the particles having a particle diameter greater than 1.0 μm refer to inorganic particles such as silica, and organic particles containing resins such as fluororesin and acrylic resin, and the particle diameter is greater than 1.0 μm. Thus, in the case of coating the resin composition by aerosol jet printing, nozzle clogging can be prevented.

[0055] (B) Polyfunctional thermosetting compound

[0056] The insulating resin composition of the present embodiment contains a polyfunctional thermosetting compound (B) (hereinafter, also referred to as "component (B)"). The polyfunctional thermosetting compound (B) includes heat- and light-curable compounds. By having two or more functional groups, the polyfunctional thermosetting compound (B) can crosslink and network component (B) with a curing agent (C) described later by heat treatment, or can cause a radical polymerization reaction of component (B) by heat treatment and / or UV treatment, thereby curing the resin composition and imparting adhesive strength. Examples of the polyfunctional thermosetting compound include polyfunctional (meth)acrylate compounds having two or more (meth)acryloxy groups, polyfunctional epoxy compounds having two or more epoxy groups, polyfunctional maleimide compounds having two or more maleimide groups, polyfunctional allyl ester compounds having two or more allyl ester groups, etc., but are not limited to these. In one mode, the polyfunctional thermosetting compound (B) is preferably a polyfunctional (meth)acrylate compound, a polyfunctional epoxy compound, or a combination thereof.

[0057] The multifunctional (meth)acrylate compound can be cured by heat treatment and / or UV treatment. Examples of the multifunctional (meth)acrylate compound include trimethylolpropane tri(meth)acrylate, 3-methyl-1,5-pentanediol di(meth)acrylate, glycidyl (meth)acrylate, ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, tetramethylene glycol di(meth)acrylate, glycerol di(meth)acrylate, trimethylolpropane di(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, etc., but are not limited thereto.

[0058] The polyfunctional epoxy compound can be cured by heat treatment. Examples of the polyfunctional epoxy compound include bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, phenol novolac type epoxy compounds, alicyclic epoxy compounds, tetra(hydroxyphenyl)ethane type or tri(hydroxyphenyl)methane type epoxy compounds as polyfunctional epoxy compounds having multiple benzene rings, biphenyl type epoxy compounds, trisphenol methane type epoxy compounds, polybutadiene type epoxy compounds (epoxidized polybutadiene), naphthalene type epoxy compounds, dicyclopentadiene type epoxy compounds, aminophenol type epoxy compounds, silicone epoxy compounds, etc., but are not limited to these. Polyglycidyl esters such as diglycidyl ether of bisphenol A ethylene oxide adduct, diglycidyl ether of bisphenol A propylene oxide adduct, and reaction products of terephthalyl alcohol and 1-chloro-2,3-propylene oxide can also be used as polyfunctional epoxy compounds.

[0059] The polyfunctional maleimide compound can be cured by heat treatment and / or UV treatment. Examples of the polyfunctional maleimide compound include, but are not limited to, bismaleimide compounds such as N,N’-(4,4’-diphenylmethane) bismaleimide, bis(3-ethyl-5-methyl-4-maleimidephenyl) methane, 2,2-bis[4-(4-maleimidephenoxy)phenyl] propane. Another example of the polyfunctional maleimide compound includes a compound obtained by the reaction of a dimer acid diamine and maleic anhydride, and a compound obtained by the reaction of a maleimidated amino acid such as maleimide acetic acid or maleimide hexanoic acid and a polyol. The maleimidated amino acid is obtained by reacting maleic anhydride with glycine or aminohexanoic acid. As the polyol, polyether polyol, polyester polyol, polycarbonate polyol, poly(meth)acrylate polyol is preferred, and a polyol without an aromatic ring is particularly preferred. Since the maleimide group can react with an allyl group, the combination with a polyfunctional allyl ester compound is also preferred. As the polyfunctional allyl ester compound, an aliphatic polyfunctional allyl ester compound is preferred, and among them, a compound obtained by the transesterification of cyclohexane diallyl ester and an aliphatic polyol is more preferred.

[0060] In the present embodiment, from the viewpoint of the viscosity of the resin composition, the polyfunctional thermosetting compound (B) preferably contains a bifunctional thermosetting compound. In one aspect, from the viewpoint of increasing the elastic modulus of the cured product, the polyfunctional thermosetting compound (B) preferably contains a thermosetting compound having three or more functional groups. In one aspect, the polyfunctional thermosetting compound (B) preferably contains a bifunctional thermosetting compound and a thermosetting compound having three or more functional groups in combination.

[0061] The polyfunctional thermosetting compound (B) is preferably liquid at a temperature of 25°C.

[0062] In the present embodiment, from the viewpoint of moderately increasing the elastic modulus of the cured product, the content of the polyfunctional thermosetting compound (B) is preferably 20 to 80 parts by mass, more preferably 20 to 75 parts by mass, and preferably 30 to 70 parts by mass with respect to 100 parts by mass of the resin composition.

[0063] (C) Curing agent

[0064] The insulating resin composition of the present embodiment contains a curing agent (C) (hereinafter also referred to as "component (C)"). Therefore, by subjecting component (B) and component (C) to crosslinking and networking using heat treatment, or by subjecting the radical polymerization reaction of component (B) initiated by component (C) using heat treatment and / or UV treatment, the resin composition can be cured. In the present embodiment, the curing agent (C) includes a curing agent for crosslinking reaction (C1) and a curing agent for radical polymerization reaction (C2). As the curing agent (C1) for crosslinking reaction, a phenolic curing agent, an acid anhydride curing agent, an amine curing agent, a modified imidazole curing agent, a hydrazide compound, dicyandiamide, a thiol curing agent, etc. can be used, but are not limited to these. From the viewpoint of the adhesiveness of the resin composition, a phenolic curing agent is more preferred. It should be noted that in the present embodiment, the curing agent (C1) for crosslinking reaction also includes a substance called a so-called curing accelerator that plays a catalytic role to promote crosslinking. As the curing agent (C2) for radical polymerization reaction, a photo radical polymerization initiator and a thermal radical polymerization initiator can be cited. The curing agent (C) can be appropriately selected according to the type of component (B).

[0065] Curing agent (C1) for crosslinking reaction

[0066] When component (B) contains a polyfunctional thermosetting compound such as a polyfunctional epoxy compound, the resin composition of the present embodiment preferably contains a curing agent (C1) for crosslinking reaction.

[0067] As the phenolic curing agent, a phenolic resin known as a curing agent for epoxy resin can be used. Specific examples of the phenolic curing agent include novolac-type or linear phenolic-type phenolic resins, alkyl novolac-type phenolic resins, alkyl linear phenolic-type phenolic resins, aralkyl linear phenolic-type phenolic resins, xylene resins, allyl phenolic resins, etc., but are not limited to these. The OH equivalent of the phenolic curing agent is preferably 80 to 250 g / eq, more preferably 80 to 200 g / eq. In the case of an alkyl novolac-type or alkyl linear phenolic-type phenolic resin, as the alkyl, an alkyl having 1 to 18 carbon atoms can be used, preferably an alkyl having 2 to 10 carbon atoms such as ethyl, propyl, butyl, pentyl, hexyl, octyl, nonyl, decyl. Commercially available products of the phenolic curing agent include a phenolic resin-based curing agent (trade name: MEH8005) manufactured by Meiko Kasei Co., Ltd., etc., but are not limited thereto.

[0068] As the acid anhydride-based curing agent, acid anhydrides known as curing agents for epoxy resins can be used. Specific examples of the acid anhydride-based curing agent include, but are not limited to, phthalic anhydride, maleic anhydride, dodecenyl succinic anhydride, trimellitic anhydride, benzophenone tetracarboxylic dianhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, etc. Commercially available products of the acid anhydride-based curing agent include, but are not limited to, the acid anhydride-based curing agent manufactured by Mitsubishi Chemical Corporation (trade name: YH307).

[0069] Among amine-based curing agents, in addition to aliphatic amines and aromatic amines, imidazoles are also included. Among these, imidazoles can also be used as curing accelerators that promote the reaction between epoxy compounds and curing agents.

[0070] Examples of aliphatic amines include aliphatic polyamines such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine, trimethylhexamethylenediamine, m-xylenediamine, 2-methylpentamethylenediamine, etc.; alicyclic polyamines such as isophoronediamine, 1,3-bis(aminomethyl)cyclohexane, bis(4-aminocyclohexyl)methane, norbornenediamine, 1,2-diaminocyclohexane, etc.; piperazine-type polyamines such as N-aminoethylpiperazine, 1,4-bis(2-amino-2-methylpropyl)piperazine, etc., but are not limited to these.

[0071] Examples of aromatic amines include aromatic polyamines such as diaminodiphenylmethane, m-phenylenediamine, diaminodiphenyl sulfone, diethyltoluenediamine, trimethylenebis(4-aminobenzoate), polytetramethylene oxide-di-p-aminobenzoate, tris(dimethylaminomethyl)phenol, benzyldimethylamine, 1,8-diazabicyclo(5,4,0)undecene-7, etc., but are not limited to these.

[0072] Examples of imidazoles include imidazole compounds such as 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-methylimidazole, 2-phenyl-4-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, etc., but are not limited to these.

[0073] Examples of the modified imidazole-based curing agent include epoxy-imidazole adduct compounds and acrylate-imidazole adduct compounds. Examples of commercially available epoxy-imidazole adduct compounds include curing agents manufactured by Ajinomoto Fine-Techno Co., Ltd. (trade names: Ajicure PN-23, Ajicure PN-40), curing agents manufactured by Asahi Kasei E-Materials Co., Ltd. (trade name: NOVACURE HX-3721), curing agents manufactured by T&K TOKA Co., Ltd. (trade name: FUJICURE FX-1000), etc., but are not limited to these. Examples of commercially available acrylate-imidazole adduct compounds include, for example, a curing agent manufactured by ADEKA Corporation (trade name: EH2021), etc., but are not limited thereto.

[0074] Examples of the thiol-based curing agent include 2-ethylhexyl 3-mercaptopropionate, n-octyl 3-mercaptopropionate, tetraethylene glycol bis(3-mercaptopropionate), trimethylolpropane tris(3-mercaptopropionate), tris[(3-mercaptopropionyloxy)ethyl] isocyanurate, polysulfide polymer, 1,4-bis(3-mercaptobutyryloxy)butane, 1,3,5-tris(3-mercaptobutyryloxyethyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, trimethylolpropane tris(3-mercaptobutyrate), trimethylolethane tris(3-mercaptobutyrate), etc., but are not limited to these. The thiol-based curing agent can also react with polyfunctional (meth)acrylate compounds and polyfunctional maleimide compounds.

[0075] (C1)Any one kind of curing agent can be used, or two or more kinds can be used in combination.

[0076] From the viewpoints of storage stability and curability, the (C1) curing agent is preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the resin composition (excluding the solvent).

[0077] (C2)Curing agent for radical polymerization reaction

[0078] When the component (B) contains polyfunctional thermosetting compounds such as polyfunctional (meth)acrylate compounds and polyfunctional maleimide compounds, the resin composition of the present embodiment preferably contains a (C2) curing agent for radical polymerization reaction.

[0079] When component (B) contains a polyfunctional (meth)acrylate compound and a polyfunctional maleimide compound, the resin composition of the present embodiment may contain a photoinitiator for free radical polymerization. By including a photoinitiator for free radical polymerization, the UV curing is promoted. Thus, for example, the resin composition can also be temporarily fixed by UV curing. Examples of the photoinitiator for free radical polymerization include alkylbenzophenone compounds, acylphosphine oxide compounds, and the like.

[0080] Examples of the alkylbenzophenone compound include benzoin dimethyl ketal such as 2,2-dimethoxy-1,2-diphenylethane-1-one (for example, as a commercial product, Omnirad 651 manufactured by IGM Resins B.V.); α-aminoalkylbenzophenone such as 2-methyl-2-morpholino(4-methylthiophenyl)propan-1-one (for example, as a commercial product, Omnirad 907 manufactured by IGM Resins B.V.); α-hydroxyalkylbenzophenone such as 1-hydroxy-cyclohexyl-phenyl-ketone (for example, as a commercial product, Omnirad 184 manufactured by IGM Resins B.V.); 2-dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one (for example, as a commercial product, Omnirad 379EG manufactured by IGM Resins B.V.), 2-benzyl-2-(dimethylamino)-4'-morpholinobenzophenone (for example, as a commercial product, Omnirad 369 manufactured by IGM Resins B.V.), etc., but are not limited to these.

[0081] Examples of the acylphosphine oxide compound include 2,4,6-trimethylbenzoyl-diphenyl-oxide phosphine (for example, as a commercial product, Omnirad TPO H manufactured by IGM Resins B.V.), bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (for example, as a commercial product, Omnirad 819 manufactured by IGM Resins B.V.), etc., but are not limited to these.

[0082] Regarding the photoinitiator for free radical polymerization, any one kind can be used, or two or more kinds can be used in combination.

[0083] When the resin composition contains a photoinitiator for free radical polymerization, from the viewpoints of the curing rate and pot life of the resin composition, the content of the photoinitiator for free radical polymerization is preferably 0.01 to 5% by mass, more preferably 0.1 to 3% by mass, based on the total mass of the resin composition.

[0084] When component (B) contains a polyfunctional (meth)acrylate compound and a polyfunctional maleimide compound, the resin composition of the present embodiment may contain a thermal free radical polymerization initiator. By making the resin composition contain a thermal free radical polymerization initiator, the resin composition can be cured by heating for a short time. The thermal free radical polymerization initiator that can be used is not particularly limited, and known materials can be used. Specific examples of the thermal free radical polymerization initiator include dialkyl peroxides such as dicumyl peroxide, tert-butyl cumyl peroxide, 1,3-bis(2-tert-butylperoxyisopropyl)benzene, or 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane; peroxyketals such as 1,1-bis(tert-butylperoxy)cyclohexane, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(tert-amylperoxy)cyclohexane, 2,2-bis(tert-butylperoxy)butane, n-butyl 4,4-bis(tert-butylperoxy)valerate, or ethyl 3,3-(tert-butylperoxy)butyrate; and alkyl peroxy esters such as tert-butyl 2-ethylhexanoate, 1,1,3,3-tetramethylbutyl 2-ethylhexanoate, tert-butyl isobutyrate, tert-butyl maleate, or tert-butyl benzoate, but are not limited to these. Regarding the thermal free radical polymerization initiator, any one kind can be used, or two or more kinds can be used in combination.

[0085] When the resin composition contains a thermal free radical polymerization initiator, the content of the thermal free radical polymerization initiator is preferably 0.01 to 5% by mass, more preferably 0.1 to 3% by mass, based on the total mass of the resin composition.

[0086] For (C) the curing agent, any one kind can be used, or two or more kinds can be used in combination.

[0087] (D) Monofunctional reactive diluent

[0088] The resin composition of the present embodiment preferably contains (D) a monofunctional reactive diluent (hereinafter, also referred to as "component (D)"). By containing the (D) monofunctional reactive diluent, the viscosity of the resin composition can be reduced. In addition, since it is monofunctional, crosslinking is not formed, the increase in the internal stress of the cured product due to the excessive crosslinking density can be suppressed, the curing shrinkage of the cured product can be suppressed, and flexibility can be imparted. Examples of the (D) monofunctional reactive diluent include monofunctional (meth)acrylate compounds, monofunctional maleimide compounds, monofunctional epoxy compounds, and the like. In the present embodiment, the (D) monofunctional reactive diluent is preferably a monofunctional (meth)acrylate compound. In a certain mode, the (D) monofunctional reactive diluent preferably contains a monofunctional reactive diluent having a rigid structure such as an isobornyl structure or a dicyclopentadienyl structure. By containing the monofunctional reactive diluent having a rigid structure, the resin composition can have a low viscosity, the glass transition temperature (Tg) of the cured product can be increased, and the shrinkage rate of the cured product can be reduced.

[0089] Examples of the monofunctional (meth)acrylate compound include ethyl (meth)acrylate, trifluoroethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, glycidyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, isopentyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isodecyl (meth)acrylate, isobornyl (meth)acrylate, stearyl (meth)acrylate, lauryl (meth)acrylate, phenoxyethyl (meth)acrylate, benzyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, ethoxydiethylene glycol (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, butoxydiethylene glycol (meth)acrylate, methoxydipropylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, methoxytriethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, 2-ethylhexyldiethylene glycol (meth)acrylate, 4-tert-butylcyclohexyl (meth)acrylate, 3-phenoxybenzyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, octyl acrylate, nonyl acrylate, isononyl acrylate, 3,3,5-trimethylcyclohexyl acrylate, cyclic trimethylolpropane formal acrylate, 1-naphthylmethyl (meth)acrylate, 1-ethylcyclohexyl (meth)acrylate, 1-methylcyclohexyl (meth)acrylate, 1-ethylcyclopentyl (meth)acrylate, 1-methylcyclopentyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyl oxyethyl (meth)acrylate, dicyclopentyl (meth)acrylate, nonylphenoxypolyethylene glycol (meth)acrylate, tetrahydrodicyclopentadienyl (meth)acrylate, 2-(o-phenylphenoxy)ethyl (meth)acrylate, isobornylcyclohexyl (meth)acrylate, (2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, 1-adamantyl (meth)acrylate, 3-hydroxy-1-adamantyl (meth)acrylate, (2-methyl-2-adamantyl) (meth)acrylate, (2-ethyl-2-adamantyl) (meth)acrylate, (2-isopropyladamantan-2-yl) (meth)acrylate, 3-hydroxy-1-adamantyl (meth)acrylate, (adamantan-1-yloxy)methyl (meth)acrylate, 2-isopropyl-2-adamantyl (meth)acrylate, 1-methyl-1-ethyl-1-adamantylmethanol (meth)acrylate, 1,1-Diethyl-1-adamantylmethyl (meth)acrylate, (2-cyclohexylpropan-2-yl) (meth)acrylate, 1-isopropylcyclohexyl (meth)acrylate, 1-methylcyclohexyl (meth)acrylate, 1-ethylcyclopentyl (meth)acrylate, 1-methylcyclohexyl (meth)acrylate, tetrahydropyranyl (meth)acrylate, tetrahydro-2-furanyl (meth)acrylate, (2-oxatetrahydrofuran-3-yl) (meth)acrylate, (5-oxatetrahydrofuran-2-yl)methyl (meth)acrylate, (2-oxa-1,3-dioxolan-4-yl)methyl (meth)acrylate, 1-ethoxyethyl (meth)acrylate, etc., but not limited to these. They can be used alone or in combination of two or more. Among these, monofunctional reactive diluents having an isobornyl structure such as isobornyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, dicyclopentyl (meth)acrylate, and dicyclopentenyl (meth)acrylate, which have a dicyclopentadienyl structure, are preferred. They can be used alone or in combination of two or more.,

[0090] Examples of the monofunctional maleimide compound include maleimide; maleimides having an aliphatic hydrocarbon group such as methylmaleimide, ethylmaleimide, propylmaleimide, butylmaleimide, hexylmaleimide, octylmaleimide, dodecylmaleimide, stearylmaleimide, and cyclohexylmaleimide; maleimides having an aromatic ring such as phenylmaleimide, etc., but not limited to these. They can be used alone or in combination of two or more.,

[0091] Examples of the monofunctional epoxy compound include aromatic monofunctional epoxy compounds such as phenyl glycidyl ether, tolyl glycidyl ether, p-sec-butylphenyl glycidyl ether, styrene oxide, p-tert-butylphenyl glycidyl ether, o-phenylphenol glycidyl ether, p-phenylphenol glycidyl ether, and N-glycidyl phthalimide; aliphatic monofunctional epoxy compounds such as n-butyl glycidyl ether, 2-ethylhexyl glycidyl ether, α-epoxypinene, allyl glycidyl ether, 1-vinyl-3,4-epoxycyclohexane, 1,2-epoxy-4-(2-methyloxiranyl)-1-methylcyclohexane, 1,3-bis(3-glycidyloxypropyl)-1,1,3,3-tetramethyldisiloxane, and glycidyl neodecanoate, etc., but not limited to these. They can be used alone or in combination of two or more.,

[0092] As the monofunctional reactive diluent, any one kind can be used, or two or more kinds can be used in combination.,

[0093] When the resin composition of the present embodiment contains (D) a monofunctional reactive diluent, the content of the (D) monofunctional reactive diluent is preferably 40 to 80 parts by mass, more preferably 45 to 70 parts by mass, based on 100 parts by mass of the total amount of (B) a polyfunctional thermosetting compound, (C) a curing agent, and (D) a monofunctional reactive diluent. By setting the proportion of the (D) monofunctional reactive diluent within the above range, the viscosity of the resin composition can be reduced, and the coating property can be further improved in the aerosol jetting method.

[0094] (E) Other additives

[0095] The resin composition of the present embodiment can contain other additives, such as carbon black, titanium black, silane coupling agent, ion trap, leveling agent, antioxidant, defoaming agent, viscosity modifier, flame retardant, or solvent, etc., within the range that does not impair the characteristics of the resin composition of the present embodiment as desired and as needed. The type and addition amount of each additive are as shown in the conventional method.

[0096] The method for producing the resin composition of the present embodiment is not particularly limited. For the resin composition, for example, the components (A) to (C), the component (D) as needed, and (E) other additives are simultaneously or separately introduced into an appropriate mixer, and if necessary, they are stirred and mixed while being melted by heating to form a uniform composition, whereby the resin composition of the present embodiment can be obtained. The mixer is not particularly limited, and a kneader, Henschel mixer, three-roll mill, ball mill, planetary mixer, bead mill, etc. equipped with a stirring device and a heating device can be used. In addition, these devices can also be used in appropriate combination.

[0097] The resin composition thus obtained is thermosetting and can be cured, for example, by heat treatment at 130 to 200 °C for 30 to 180 minutes.

[0098] In addition, when the component (B) contains a polyfunctional (meth)acrylate compound and a polyfunctional maleimide compound, the resin composition is photocurable and thermosetting. In this case, after applying the resin composition, light of a specified wavelength can be irradiated for temporary fixation, and then it can be formally cured by heating to form a cured product. The specific methods of temporary fixation and formal curing are not particularly limited. When the resin composition is photocured, the irradiated light is, for example, ultraviolet light (UV). In a certain mode, the resin composition can also be only photocured.

[0099] In this embodiment, the viscosity of the resin composition measured using an E-type viscometer at 25°C and 50 rpm is 400 mPa·s or less, preferably 350 mPa·s or less, and more preferably 300 mPa·s or less. Although the resin composition of this embodiment contains inorganic particles with a small particle size, due to its low viscosity, it is suitable for aerosol jet printing. From the perspective of suppressing curing shrinkage, the lower limit of the viscosity of the resin composition measured using an E-type viscometer at 25°C and 50 rpm is, for example, 50 mPa·s or more, preferably 100 mPa·s or more, and more preferably 200 mPa·s or more. In a certain mode, the viscosity of the resin composition measured using an E-type viscometer at 25°C and 50 rpm is preferably 50 to 400 Pa·s, more preferably 100 to 350 Pa·s, and 200 to 300 Pa·s.

[0100] The application method of the resin composition of this embodiment is not particularly limited. For example, it can be supplied to a desired part such as a substrate by a known printing method, dispensing method, or coating method. Examples of the printing or dispensing method include, but are not limited to, aerosol jet printing, inkjet printing (jet dispensing printing), screen printing, lithographic printing, carton printing, metal printing, offset printing, intaglio printing, flexographic printing, air dispenser, etc. Examples of the coating method include, but are not limited to, dip coating, spraying, bar coater coating, gravure coating, reverse gravure coating, spin coater coating, etc.

[0101] The application method of the resin composition of this embodiment is preferably aerosol jet printing or inkjet printing, and more preferably aerosol jet printing. The use of the insulating resin composition of this embodiment in aerosol jet printing or inkjet printing is also an embodiment of the present invention.

[0102] [Cured product of resin composition]

[0103] The cured product of the second embodiment of the present invention is a cured product obtained by curing the insulating resin composition of the above first embodiment.

[0104] From the perspective of adhesiveness, the elastic modulus of the cured product of this embodiment is preferably 1.0 to 9.0 GPa, more preferably 3.5 to 8.0 GPa, and further preferably 4.0 to 7.0 GPa. The elastic modulus of the cured product can be adjusted by adjusting the type and amount of the components of the resin composition. For example, when rigid structures such as biphenyl, naphthalene, dicyclopentadiene, cresol novolac, isobornyl, and dicyclopentadienyl are included in each component, the elastic modulus tends to increase. In addition, for example, by including a polyfunctional thermosetting compound with 3 or more functional groups to increase the crosslinking density, the elastic modulus tends to increase.

[0105] From the viewpoint of reflow solderability, the cured product of the present embodiment preferably has a glass transition temperature (Tg) of 60°C or higher, more preferably 70°C or higher, and further preferably 80°C or higher. The Tg of the cured product can be adjusted by adjusting the types and amounts of the components of the resin composition. For example, when rigid structures such as biphenyl, naphthalene, dicyclopentadiene, cresol novolac, isobornyl, and dicyclopentadienyl are included in each component, there is a tendency for the Tg to increase. In addition, for example, by including a polyfunctional thermosetting compound having 3 or more functional groups to increase the crosslinking density, there is a tendency for the Tg to increase. Regarding the upper limit of the Tg of the cured product, there is no particular limitation, and it is preferably 260°C or lower.

[0106] [Electronic component]

[0107] The electronic component of the third embodiment of the present invention includes the cured product of the above second embodiment. As the electronic component, for example, it is a semiconductor package or the like manufactured by bonding a semiconductor chip (die) such as an IC or an LSI to a support member such as a substrate, performing wire bonding (Japanese: bonding) from the die to the support member, and then sealing with a molding agent. Such a semiconductor package can be mounted on a printed circuit board or a mother board.

[0108] [Printing method, manufacturing method of cured product]

[0109] Another embodiment of the present invention is the following aerosol jet printing method, which includes the step of aerosol jet printing the insulating resin composition of the above first embodiment on an object to be printed.

[0110] In aerosol jet printing technology, fine droplets with a diameter of 10 μm or less are produced, transported to the spray section (nozzle) by gas, and the On-Off of the jet from the nozzle to the substrate is digitally controlled, thereby enabling the formation of fine patterns with a minimum line width of 10 μm, for example. In addition, in this aerosol jet printing technology, the distance between the substrate and the nozzle during printing is wide, and printing can be performed even with a printing gap of about 5 mm. Therefore, printing can also be performed on a substrate with irregularities of about several mm or a three-dimensional curved surface.

[0111] The object to be printed is, for example, a component constituting an electronic component, such as a semiconductor element, a substrate, etc., but is not limited to these. The material of the component can be any one of engineering plastics (such as LCP (liquid crystal polymer), polyamide, polycarbonate, etc.), ceramics, or metals (such as copper, nickel).

[0112] Another embodiment of the present invention is the following manufacturing method of a cured product, which includes:

[0113] The step of aerosol jet printing the insulating resin composition of the above first embodiment on an object to be printed;

[0114] The step of curing the aerosol-jet-printed insulating resin composition.

[0115] Another embodiment of the present invention is the following inkjet printing method, which includes the step of inkjet printing the insulating resin composition of the above first embodiment on an object to be printed.

[0116] The object to be printed is, for example, a component constituting an electronic component, such as a semiconductor element, a substrate, etc., but is not limited to these. The material of the component can be any one of engineering plastics (such as LCP (liquid crystal polymer), polyamide, polycarbonate, etc.), ceramics, or metals (such as copper, nickel), etc.

[0117] Another embodiment of the present invention is the following method for manufacturing a cured product, which includes:

[0118] The step of inkjet printing the insulating resin composition of the above first embodiment on an object to be printed;

[0119] The step of curing the inkjet-printed insulating resin composition.

[0120] Examples

[0121] Hereinafter, the present invention will be further described in detail by way of examples and comparative examples, but the present invention is not limited to these examples. It should be noted that in the following examples, parts and % represent parts by mass and mass %, respectively, unless otherwise specified.

[0122] [Examples 1 to 12, Comparative Examples 1 to 4]

[0123] [Preparation of Resin Composition]

[0124] According to the formulation shown in Table 1, a specified amount of each component was mixed using a three-roll mill to prepare a resin composition. In Table 1, the amounts of the components are expressed in parts by mass (unit: g). The components used in the examples and comparative examples are as described below.

[0125] · (A) Inorganic particles having an average particle diameter (D50) of 0.02 to 0.5 μm

[0126] (A-1): (Meth)acrylic acid-based surface-treated silica filler 1 (trade name: YC100-SM1, manufactured by Admatechs Co., Ltd., average particle diameter (D50): 0.1 μm, surface treatment agent: 3-methacryloxypropyltrimethoxysilane)

[0127] (A-2): (Meth)acrylic acid-based surface-treated silica filler 2 (trade name: YA050C-SM1, manufactured by Admatechs Co., Ltd., average particle diameter (D50): 0.05 μm, surface treatment agent: 3-methacryloxypropyltrimethoxysilane)

[0128] · Inorganic particles other than component (A') (A)

[0129] (A'-1): (Meth)acrylic acid-based surface-treated silica filler 3 (trade name: SE2200-SME, manufactured by Admatechs Co., Ltd., average particle size (D50): over 1 μm, surface treatment agent: 3-glycidoxypropyltrimethoxysilane)

[0130] (A'-2): (Meth)acrylic acid-based surface-treated silica filler 4 (trade name: YA010C-SM1, manufactured by Admatechs Co., Ltd., average particle size (D50): 0.01 μm, surface treatment agent: 3-methacryloxypropyltrimethoxysilane)

[0131] (A'-3): Untreated silica filler (trade name: SEAHOSTAR KE-S30HG, manufactured by Nippon Shokubai Co., Ltd., average particle size (D50): 0.3 μm)

[0132] (A'-4): Trimethyl surface-treated silica filler (AEROSIL (registered trademark) RX50, manufactured by Nippon AEROSIL Co., Ltd., average particle size (D50): 0.02 - 0.10 μm)

[0133] · (B) Polyfunctional thermosetting compound

[0134] (B-1): 3-functional (meth)acrylate compound (chemical name: trimethylolpropane triacrylate, trade name: LIGHT ACRYLATE TMP-A, manufactured by Kyoeisha Chemical Co., Ltd., viscosity: 80 - 120 mPa·s, Cas.No: 15625-89-5)

[0135] (B-2): 2-functional (meth)acrylate compound 1 (chemical name: 3-methyl-1,5-pentanediol diacrylate, trade name: LIGHT ACRYLATE MPD-A, manufactured by Kyoeisha Chemical Co., Ltd., viscosity: 8 mPa·s, Cas.No: 64194-22-5)

[0136] (B-3): 2-functional (meth)acrylate compound 2 (chemical name: 1,9-nonanediol diacrylate, trade name: LIGHT ACRYLATE 1.9ND-A, manufactured by Kyoeisha Chemical Co., Ltd., viscosity: 10 mPa·s, Cas.No: 107481-28-7)

[0137] (B-4): trifunctional epoxy compound (chemical name: N,N-diglycidyl-4-(glycidyloxy)aniline, trade name: jER-630, manufactured by Mitsubishi Chemical Corporation, viscosity: 5000 - 10000 mPa·s, Cas.No: 5026-74-4)

[0138] (B-5): bifunctional epoxy compound 1 (polyoxyalkylene bisphenol A diglycidyl ether, trade name: EP4000S, manufactured by ADEKA Corporation, viscosity: 1800 mPa·s, Cas.No: 36484-54-5)

[0139] (B-6): bifunctional epoxy compound 2 (tetramethylbiphenyl epoxy compound, trade name: YX4000H, manufactured by Mitsubishi Chemical Corporation, solid (at room temperature), Cas.No: 85954-11-6)

[0140] (B-7): bifunctional epoxy compound 3 (polypropylene glycol type epoxy compound, trade name: PG207GS, manufactured by NIPPON STEEL Chemical & Material Co., Ltd., viscosity: 20 - 70 mPa·s, Cas.No: 9072-62-2)

[0141] · (C) Curing agent

[0142] (C-1): phenolic curing agent (trade name: MEH8005, manufactured by Meiwafosis Co., Ltd., viscosity: 4500 - 7500 mPa·s, Cas.No: 27924-97-6 or 9003-35-4)

[0143] (C-2): imidazole-based curing agent (chemical name: 4-methyl-2-phenylimidazole, trade name: 2P 4MZ, manufactured by Shikoku Kasei Kogyo Co., Ltd., Cas.No: 827-43-0)

[0144] (C-3): 1-hydroxy-cyclohexyl-phenyl-ketone (photoinitiator for free radical polymerization, trade name: Omnirad 184, manufactured by IGM Resins B.V., solid (at room temperature), Cas.No: 947-19-3)

[0145] (C-4): 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (photoinitiator for free radical polymerization, trade name: Omnirad TPO H, manufactured by IGM Resins B.V., solid (at room temperature), Cas.No: 75980-60-8)

[0146] (C-5): 1,1,3,3-Tetramethylbutyl 2-ethylhexanoate peroxide (thermal free radical polymerization initiator, trade name: PEROCTA O, manufactured by NOF Corporation, liquid (at room temperature), Cas.No: 22288-43-3)

[0147] · (D) Monofunctional reactive diluent

[0148] (D-1): Isobornyl acrylate (trade name: IBXA, manufactured by Kyoeisha Chemical Co., Ltd., viscosity: 5 - 10 mPa·s, Cas.No: 5888-33-5)

[0149] (D-2): Dicyclopentanyl acrylate (trade name: FA513AS, manufactured by Showa Denko Materials Co., Ltd., viscosity: 7 - 17 mPa·s, Cas.No: 79637-74-4)

[0150] In the examples and comparative examples, the properties of the resin composition and the cured product obtained by curing the resin composition were measured as follows.

[0151] [Viscosity measurement]

[0152] The viscosity of each resin composition was measured at 25°C, rotation speeds of 5 rpm and 50 rpm using a cone-plate viscometer TV-22 (cone plate: 1°34’×R24) manufactured by Toki Sangyo Co., Ltd. The viscosity at a rotation speed of 50 rpm was recorded as "viscosity" in Table 1. For cases marked "N.A" in the table, it was outside the measurement range of viscosity and could not be measured. The results are shown in Table 1.

[0153] [Aerosol jet printing evaluation test]

[0154] Each resin composition was evaluated using an aerosol jet dispenser (Aerosol Jet: AJHD2, manufactured by OPTOMEC). The evaluation conditions are as follows. Nozzle 300 (μm), sheath gas 80 sccm, atomizing gas 900 sccm, distance between the nozzle and the substrate 5 mm, printing speed 10 mm / sec. Each resin composition was sprayed onto a glass substrate. The case where there was no nozzle clogging and spraying was possible was marked as "○", and the case where spraying was not possible was marked as "×". The results are shown in Table 1.

[0155] [Inkjet printing evaluation test]

[0156] Each resin composition was evaluated using an ejection dispenser (AeroJet: MJET-A-2 manufactured by Musashi Engineering, Inc.). The evaluation conditions are as described below. Sheet: W type, spray bar: M spray bar, nozzle: 26G, stroke: 100 (μm), pressure: 125 (MPa), on-time: 3.5 (msec), off-time: 5 (msec). Each resin composition was ejected onto a glass substrate. The case where there was no nozzle blockage and ejection was possible was marked as "○", and the case where ejection was not possible was marked as "×". The results are shown in Table 1.

[0157] [Measurement of Elastic Modulus and Glass Transition Temperature (Tg) of Cured Product]

[0158] Two glass plates coated with a release agent and dried were prepared. A resin composition was coated on one of them, and after further setting a gap so that the film thickness became approximately 100 μm, it was clamped with the other glass plate. It was irradiated with UV light (wavelength 365 nm) of 500 mJ / cm 2 on one side using an LED type UV irradiation device (Omnicure: AC475 manufactured by Excelitas Technologies Corp.). Then, it was turned over and irradiated with UV light (wavelength 365 nm) of 500 mJ / cm 2 on the other side. Then, it was cured into a sheet under heating conditions of 175 °C for 60 minutes. It was processed into a size of 40 mm × 5 mm and used as a test piece for dynamic viscoelasticity measurement (DMA). Using a viscoelasticity measurement device (DMS6100 manufactured by Seiko Instruments Inc.), DMA measurement was performed under the conditions of measurement mode: tension, heating rate: 3 °C / minute, measurement frequency: 10 Hz, and the elastic modulus and Tg at room temperature were determined. For the cases marked as "N.A" in the table, they were outside the measurement range and could not be measured. The results are shown in Table 1. From the viewpoint of adhesiveness, the range of the elastic modulus of the cured product is preferably 1.0 to 9.0 GPa, more preferably 3.5 to 8.0 GPa, and further preferably 4.0 to 7.0 GPa. From the viewpoint of reflow solderability, the range of the Tg of the cured product is preferably 60 °C or higher, more preferably 70 °C or higher, and further preferably 80 °C or higher. There is no particular limitation on the upper limit, and it is preferably 260 °C or lower.

[0159] [Measurement of Shrinkage Rate of Cured Product]

[0160] Using a 10 cc specific gravity bottle made of polytetrafluoroethylene (PTFE), the specific gravity (liquid specific gravity) of the resin composition was measured at 25°C. Prepare 2 glass plates coated with a release agent and dried. Coating the resin composition on one of them, and after further setting a gap so that the film thickness becomes about 300 μm, it was clamped with the other glass plate. A single side was irradiated with UV light (wavelength 365 nm) of 500 mJ / cm 2 using an LED type UV irradiation device (manufactured by Excelitas Technologies Corp., Omnicure: AC475). Then turn it over and irradiate the other side with UV light (wavelength 365 nm) of 500 mJ / cm 2 . Then, it was cured under heating conditions of 175°C for 60 minutes. After measuring the weight (a, unit: g) of the cured film, the cured film was put into pure water and sufficiently degassed. The weight (b, unit: g) of the degassed cured film was measured, and the specific gravity (specific gravity of the cured product) was calculated by formula (1). The shrinkage rate of the cured product was calculated by formula (3). The results are shown in Table 1.

[0161] Specific gravity of cured product (g / cm 3 ) = weight of cured film (a) / volume (cm 3 ) ··· (1)

[0162] Volume (cm 3 ) = ((a) - (b)) / density of water at temperature c (g / cm 3 ) ··· (2)

[0163] Shrinkage rate (%) = {1 - (liquid specific gravity / specific gravity of cured product)} × 100 ··· (3)

[0164] From the viewpoint of suppressing peeling and cracking, the shrinkage rate of the cured product preferably ranges from 8.0% or less, more preferably 7.0% or less, still more preferably 6.0% or less, and particularly preferably 5.0% or less.

[0165] [Table 1]

[0166]

[0167] The resin compositions of Examples 1 to 12 were both ejected well in both aerosol jet printing and inkjet printing.

[0168] In Comparative Example 1 using inorganic particles with an average particle size (D50) larger than the average particle size (D50) of the (A) inorganic particles of the present invention, although the viscosity was low, the particle size of the inorganic particles was large, and the resin composition could not be aerosolized and could not be ejected by aerosol jet printing.

[0169] In Comparative Example 2 using inorganic particles having an average particle diameter (D50) smaller than the average particle diameter (D50) of the (A) inorganic particles of the present invention, the inorganic particles could not be uniformly dispersed in the resin composition, and viscosity measurement could not be performed. In addition, neither aerosol jet printing nor inkjet printing could be performed.

[0170] In Comparative Example 3 having a viscosity higher than the viscosity of the resin composition of the present invention, ejection could not be performed by aerosol jet printing.

[0171] In Comparative Example 4, the viscosity of the resin composition was too high to be measured under the conditions of 25 °C and 50 rpm using an E-type viscometer. In addition, neither aerosol jet printing nor inkjet printing could be performed.

[0172] The entire disclosure of Japanese Patent Application No. 2022-187282 (filing date: November 24, 2022) is incorporated herein by reference in its entirety.

[0173] All documents, patent applications, and technical standards described in this specification are incorporated herein by reference to the same extent as if each document, patent application, and technical standard was specifically and individually described as being incorporated by reference.

Claims

1. An insulating resin composition comprising: (A) inorganic particles having an average particle diameter D50 of 0.02 μm to 0.5 μm; (B) a polyfunctional thermosetting compound; and (C) a curing agent, wherein the viscosity of the insulating resin composition measured using an E-type viscometer at 25 °C and 50 rpm is 400 mPa·s or less.

2. The insulating resin composition according to claim 1, wherein the inorganic particles (A) have been surface-treated with a (meth)acrylic acid-based surface treatment agent.

3. The insulating resin composition according to claim 1 or 2, wherein (B) the polyfunctional thermosetting compound contains a bifunctional thermosetting compound.

4. The insulating resin composition according to any one of claims 1 to 3, further comprising (D) a monofunctional reactive diluent.

5. The insulating resin composition according to claim 4, wherein with respect to a total of 100 parts by mass of (B) the polyfunctional thermosetting compound, (C) the curing agent, and (D) the monofunctional reactive diluent, the content of (D) the monofunctional reactive diluent is 40 parts by mass to 80 parts by mass.

6. The insulating resin composition according to any one of claims 1 to 5, wherein with respect to 100 parts by mass of the resin composition, the content of the (A) inorganic particles is 15 parts by mass to 50 parts by mass.

7. The insulating resin composition according to any one of claims 1 to 6, substantially free of particles having a particle diameter greater than 1.0 μm.

8. The insulating resin composition according to any one of claims 1 to 7, for aerosol jet printing.

9. The insulating resin composition according to any one of claims 1 to 7, for inkjet printing.

10. A cured product obtained by curing the insulating resin composition according to any one of claims 1 to 9.

11. An electronic component comprising the cured product according to claim 10.

12. An aerosol jet printing method comprising the step of aerosol jet printing the insulating resin composition according to any one of claims 1 to 9 onto an object to be printed.

13. An inkjet printing method comprising the step of inkjet printing the insulating resin composition according to any one of claims 1 to 9 onto an object to be printed.

14. Use of the insulating resin composition according to any one of claims 1 to 9 in aerosol jet printing.

15. Use of the insulating resin composition according to any one of claims 1 to 9 in inkjet printing.

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