JP7473205B2 - Resin composition - Google Patents

Description

The present invention relates to a resin composition that can be used in applications requiring relatively low-temperature heat curing, specifically at about 80°C.

When manufacturing image sensor modules used as camera modules in mobile phones and smartphones, adhesives that heat cure at relatively low temperatures, specifically at around 80°C, are used. When manufacturing electronic components such as semiconductor elements, integrated circuits, large-scale integrated circuits, transistors, thyristors, diodes, and capacitors, it is preferable to use adhesives that contain a resin composition that heat cures at around 80°C.

Furthermore, when two parts with different thermal expansion coefficients are joined with an adhesive, changes in the surrounding temperature can cause thermal stress at the joint, which can lead to cracks. The adhesive used to join these parts needs to be flexible enough to follow the thermal deformation of the parts, and the cured product needs to have excellent stress relaxation properties even after the adhesive has hardened.

For example, Patent Document 1 discloses a resin composition containing a thiol compound having two or more thiol groups in the molecule, which can be thermally cured at low temperatures and produces a cured product with a low elastic modulus.

International Publication No. 2012/093510

However, adhesives mainly made of polythiol compounds with three or more thiol groups in the molecule have many crosslinking points, and residual stress in the resulting cured product may not be able to follow thermal deformation of the adherend. In addition, when the polythiol compound having two thiol groups in the molecule is a bifunctional thiol compound having thiol groups at both ends of an alkyl group, such as 1,4-butanedithiol or 1,10-decanedithiol, as disclosed in Patent Document 1, the molecular weight is small, so that even when cured at a low temperature of around 80°C, voids may exist in the resulting cured product, and the physical properties of the resulting cured product may be reduced.

Therefore, the present invention aims to provide a resin composition that can be cured at low temperatures and produces a cured product with excellent stress relaxation without compromising physical properties.

The means for solving the above problems are as follows, and the present invention includes the following aspects.
[1] (A) an epoxy resin containing no aromatic ring;
(B) at least one bifunctional thiol compound selected from the group consisting of bifunctional thiol compounds having an aromatic ring structure or an alicyclic structure in the molecule, a heteroatom, no ester bond, and a molecular chain having a thiol group at an end, and having a molecular weight of 210 or more, and bifunctional thiol compounds having an aromatic ring structure or a heterocyclic structure in the molecule, a molecular chain which may contain a heteroatom, no ester bond, and has a thiol group at an end, and having a molecular weight of 210 or more;
(C) an amine compound.
[2] The resin composition according to [1] above, wherein the component (B) is a bifunctional thiol compound containing an alicyclic structure in the molecule and a molecular chain having a thiol group at an end, the molecular chain containing a thioether bond but not an ester bond.
[3] The resin composition according to [1] above, wherein the component (B) is a bifunctional thiol compound containing an aromatic ring structure in the molecule and a molecular chain having a thiol group at an end, the molecular chain containing an ether bond but not an ester bond.
[4] The resin composition according to [1] above, wherein the component (B) is a bifunctional thiol compound represented by the following general formula (B-1), (B-2) or (B-3):

(In general formula (B-1), n and m each independently represent an integer of 1 to 3.)

(In general formula (B-2), R ¹ , R ² , R ³ and R ⁴ are each independently a hydrogen atom or a group represented by the following general formula (b-1). However, one of R ¹ and R ² is a group represented by the following general formula (b-1), and one of R ³ and R ⁴ is a group represented by the following general formula (b-1).)

(In general formula (b-1), r is an integer of 1 to 3.)

(In formula (B-3), G ₁ and G ₂ each independently represent a divalent group bonded via —O— or —CH ₂ —, and p and q each independently represent an integer of 2 to 5.)
[5] The resin composition according to [1] above, wherein the component (B) is a bifunctional thiol compound represented by the following general formula (B-4) or (B-5):

(In general formula (B-4), s and t each independently represent an integer of 3 or 4.)

(In general formula (B-5), u and v each independently represent an integer of 3 or 4.)
[6] The resin composition according to any one of [1] to [5] above, wherein the molecular weight of the component (A) is 240 to 1,000.
[7] The resin composition according to any one of [1] to [6], wherein the component (A) is an epoxy resin represented by the following formula (A-1) or (A-2):

(In formula (A-1), ^R5 is a linear or branched alkylene group having 1 to 15 carbon atoms, and w is an integer of 1 to 20.)

(In formula (A-2), R ⁶ to R ⁹ each independently represent a linear or branched alkyl group having 1 to 3 carbon atoms.)
[8] The resin composition according to any one of [1] to [7] above, wherein the amine compound of the component (C) is at least one amine compound selected from an imidazole compound, a tertiary amine compound, and an amine adduct.
[9] The resin composition according to any one of [1] to [8] above, wherein the total number of thiol groups of the bifunctional thiol compound of component (B) is 20 to 100, where the total number of thiol groups in the resin composition is 100.
[10] The resin composition according to any one of [1] to [9] above, further comprising (D) a stabilizer.
[11] The resin composition according to [10], wherein the stabilizer of the component (D) is at least one selected from the group consisting of a liquid boric acid ester compound, an aluminum chelate, and a barbituric acid.
[12] An adhesive comprising the resin composition according to any one of [1] to [11] above.
[13] An encapsulant comprising the resin composition according to any one of [1] to [11] above.
[14] An image sensor module manufactured using the adhesive according to [12] or the sealing material according to [13].
[15] A semiconductor device manufactured using the adhesive according to the above item [12] or the sealing material according to the above item [13].

According to the present invention, it is possible to provide a resin composition that can be thermally cured at a low temperature of about 80°C, and that produces a cured product with excellent stress relaxation properties without compromising physical properties.

Hereinafter, the resin composition, adhesive, encapsulant, image sensor module, and semiconductor device according to the present disclosure will be described based on the embodiments. However, the embodiments shown below are merely examples for embodying the technical concept of the present invention, and the present invention is not limited to the following resin composition, adhesive, encapsulant, image sensor module, and semiconductor device.

The resin composition according to the first embodiment of the present invention is
(A) an epoxy resin not containing an aromatic ring;
(B) at least one bifunctional thiol compound selected from the group consisting of bifunctional thiol compounds having an aromatic ring structure or an alicyclic structure in the molecule, a heteroatom, no ester bond, and a molecular chain having a thiol group at an end, and having a molecular weight of 210 or more, and bifunctional thiol compounds having an aromatic ring structure or a heterocyclic structure in the molecule, a molecular chain which may contain a heteroatom, no ester bond, and has a thiol group at an end, and having a molecular weight of 210 or more;
(C) an amine compound.

Component (A): Epoxy resin not containing aromatic ring The resin composition contains an epoxy resin not containing aromatic ring as component (A). Since the epoxy resin does not contain aromatic ring, the glass transition temperature (Tg) after the resin composition is cured is low, and the elastic modulus is low. Therefore, when two parts with different thermal expansion coefficients are bonded with an adhesive containing the resin composition of the embodiment of the present invention, even if the two bonded parts expand and contract due to the different thermal expansion coefficients due to the change in the surrounding temperature, the adhesive has flexibility that can follow the changes in the parts and is excellent in stress relaxation.

An aromatic ring is a structure that satisfies Hückel's rule, such as a benzene ring.

The epoxy resin of component (A) preferably has a weight average molecular weight of 240 to 1,000. The epoxy resin of component (A) more preferably has a weight average molecular weight of 250 to 1,000, even more preferably 260 to 1,000, and even more preferably 270 to 1,000. In this specification, the weight average molecular weight refers to a value obtained by gel permeation chromatography (GPC) using a calibration curve with standard polystyrene.

It is preferable that the epoxy resin of component (A) is an epoxy resin that does not contain an ester bond in order to improve the moisture resistance of the cured product made from the resin composition.

The component (A) is preferably, for example, an epoxy resin represented by the following formula (A-1).

In formula (A-1), R ⁵ is a linear or branched alkylene group having 1 to 15 carbon atoms, and w is an integer of 1 to 20.

The epoxy resin represented by formula (A-1) is preferably an epoxy resin represented by the following formula (A-1-1) and/or (A-1-2).

In formula (A-1-1), x is an integer from 1 to 15.

In formula (A-1-2), y is an integer from 1 to 20.

It is preferable that the component (A) is, for example, an epoxy resin represented by the following formula (A-2).

In formula (A-2), R ⁶ to R ⁹ each independently represent a linear or branched alkyl group having 1 to 3 carbon atoms.

The (A) component may be a resin composition represented by the general formula (A-1) or (A-2), or may be a hydrogenated bisphenol type epoxy resin, an alicyclic epoxy resin, an alcohol ether type epoxy resin, an aliphatic epoxy resin, a cyclic aliphatic epoxy resin, a siloxane type epoxy resin, etc. Examples of such epoxy resins include hydrogenated bisphenol A type epoxy resin, hydrogenated bisphenol F type epoxy resin, epoxy modified polybutadiene, 1,4-cyclohexanedimethanol diglycidyl ether, etc.

The resin composition according to the present invention may further contain an epoxy resin (an epoxy resin containing an aromatic ring) other than the component (A). The total number of epoxy groups contained in the epoxy resin containing no aromatic ring of the component (A) is preferably 20 to 100, more preferably 40 to 100, and even more preferably 50 to 100, when the number of all epoxy groups in the resin composition is 100. The number of epoxy groups contained in the epoxy resin containing no aromatic ring of the component (A) can be calculated by dividing the mass of the epoxy resin containing no aromatic ring of the component (A) by the epoxy group equivalent of the epoxy resin containing no aromatic ring of the component (A). The ratio of epoxy groups between the component (A) and the epoxy resin other than the component (A) can also be calculated using NMR.
When the resin composition contains an epoxy resin that does not contain an aromatic ring, the number of all epoxy groups in the epoxy resin other than component (A) can be calculated by dividing the mass of the epoxy resin other than component (A) by the epoxy group equivalent of the epoxy resin other than component (A). The sum of the number of epoxy groups in the epoxy resin other than component (A) and the number of epoxy groups in component (A) that do not contain an aromatic ring can be regarded as the total number of epoxy groups in the resin composition.

(B) component: bifunctional thiol compound The (B) bifunctional thiol compound contained in the resin composition of one embodiment of the present invention is at least one bifunctional thiol compound selected from the group consisting of bifunctional thiol compounds having an aromatic ring structure or alicyclic structure in the molecule, a molecular chain having a thiol group at the end, containing a heteroatom, not containing an ester bond, and having a molecular weight of 210 or more, and bifunctional thiol compounds having an aromatic ring structure or heterocyclic structure in the molecule, a molecular chain having a thiol group at the end, containing a heteroatom, not containing an ester bond, and having a molecular weight of 210 or more. The (B) component bifunctional thiol compound can be obtained from Shikoku Chemical Industry Co., Ltd.

The bifunctional thiol compound of component (B) has a molecular weight of 210 or more and low volatility, so that when the resin composition is thermally cured at a low temperature, for example 80°C, the bifunctional thiol compound does not volatilize, the generation of voids is suppressed, and a cured product that maintains its physical properties can be obtained. It is more preferable that the molecular weight is 280 or more. In addition, from the viewpoint of curability, it is preferable that the bifunctional thiol compound of component (B) has a molecular weight of 1,000 or less, and more preferably 600 or less.

The bifunctional thiol compound of the (B) component has a heteroatom and has good compatibility with the epoxy resin of the (A) component that does not contain an aromatic ring, and a homogeneous cured product can be obtained by curing at a low temperature of, for example, 80 ° C. The aromatic ring structure of the (B) component is a monocyclic aromatic ring structure having 5 or more members, such as cyclopentadiene and benzene. The alicyclic structure is a monocyclic alicyclic structure having 5 or more members, such as cyclopentane and cyclohexene. The heterocyclic structure may be a monocyclic or polycyclic structure, an alicyclic structure, an aromatic ring structure, or a condensed polycyclic structure. The heteroatom contained in the molecular chain is, for example, a sulfur (S) or oxygen (O) atom, and it is preferable that the molecular chain contains a thioether bond or an ether bond. From the viewpoint of compatibility with epoxy resins and low volatility, it is preferable that the bifunctional thiol compound of the (B) component contains a heteroatom that is a sulfur atom, that is, a molecular chain that contains an alicyclic structure and a thioether bond in the molecule, does not contain an ester bond, and has a thiol group at the end. In addition, from the viewpoints of compatibility with epoxy resins and low volatility, the bifunctional thiol compound of component (B) preferably contains an oxygen atom as the heteroatom, i.e., a molecular chain containing an aromatic ring structure in the molecule, an ether bond, no ester bond, and a thiol group at the end. From the viewpoint of adhesive strength to metals, the bifunctional thiol compound of component (B) more preferably contains an alicyclic structure in the molecule, a thioether bond, a molecular chain containing a thiol group at the end, no ester bond.

In addition, since the bifunctional thiol compound of component (B) has two thiol groups, when the resin composition is cured, a cured product with excellent stress relaxation properties can be obtained that has smaller residual stress and can adapt to thermal deformation of the adherend, compared to a cured product mainly composed of a trifunctional or higher thiol compound.

Furthermore, since the bifunctional thiol compound of component (B) does not contain an ester bond in its molecule, it has high hydrolysis resistance even under high temperature and high humidity conditions, such as in a pressure cooker test (hereinafter also referred to as "PCT"), and is able to maintain the adhesive strength of the resulting cured product.

The component (B) is preferably, for example, a bifunctional thiol compound represented by the following general formula (B-1). The bifunctional thiol compound represented by (B-1) is available from Shikoku Chemical Industries Co., Ltd.

In general formula (B-1), n and m are each independently an integer from 1 to 3, and it is preferable that n and m are each 2.

The bifunctional thiol compound represented by the general formula (B-1) is preferably a bifunctional thiol compound represented by the following general formula (B-1-1):

The component (B) is preferably, for example, a bifunctional thiol compound represented by the following general formula (B-2). The bifunctional thiol compound represented by (B-2) is available from Shikoku Chemical Industries Co., Ltd.

In general formula (B-2), R ¹ , R ² , R ³ and R ⁴ are each independently a hydrogen atom or a group represented by the following general formula (b-1), provided that either one of R ¹ and R ² is a group represented by the following general formula (b-1), and either one of R ³ and R ⁴ is a group represented by the following general formula (b-1).

In general formula (b-1), r is an integer from 1 to 3, preferably 2.

The bifunctional thiol compound represented by the general formula (B-2) is preferably a bifunctional thiol compound represented by the following general formula (B-2-1):

The component (B) is preferably, for example, a bifunctional thiol compound represented by the following general formula (B-3). The bifunctional thiol compound represented by (B-3) is available from Shikoku Chemical Industries Co., Ltd.

In general formula (B-3), G ₁ and G ₂ are each independently a divalent group bonded via -O- or -CH ₂ -, and p and q are each independently an integer of 2 to 5. G ₁ and G ₂ are preferably a divalent group bonded via -O-, and p and q are preferably 3 or 4, and more preferably 4.

The bifunctional thiol compound represented by the general formula (B-3) is preferably a bifunctional thiol compound represented by the following general formula (B-3-1):

The component (B) is preferably, for example, a bifunctional thiol compound represented by the following general formula (B-4). The bifunctional thiol compound represented by (B-4) is available from Shikoku Chemical Industries Co., Ltd.

In general formula (B-4), s and t are each independently an integer of 3 or 4, preferably 4.

The component (B) is preferably, for example, a bifunctional thiol compound represented by the following general formula (B-5). The bifunctional thiol compound represented by (B-5) is available from Shikoku Chemical Industries Co., Ltd.

In general formula (B-5), u and v are each independently an integer of 3 or 4, preferably 4.

In the resin composition of one embodiment of the present invention, a thiol compound other than the component (B) (monofunctional thiol compound, bifunctional thiol compound, trifunctional or higher thiol compound) may be further contained. The total number of thiol groups contained in the bifunctional thiol compound of the component (B) is preferably 20 to 100, more preferably 40 to 100, and even more preferably 50 to 100, when the number of all thiol groups in the resin composition is 100. The number of thiol groups contained in the bifunctional thiol compound of the component (B) can be calculated by dividing the mass of the bifunctional thiol compound of the component (B) by the thiol group equivalent of the bifunctional thiol compound of the component (B). The ratio of thiol groups of the component (B) and thiol compounds other than the component (B) can also be calculated using NMR.
When the resin composition contains thiol compounds other than the bifunctional thiol compound of component (B), the number of all thiol groups of the thiol compounds other than component (B) can be calculated by dividing the mass of the thiol compounds other than component (B) by the thiol group equivalent of the thiol compounds other than component (B), and the sum of the number of thiol groups other than component (B) and the thiol groups of the bifunctional thiol compound of component (B) can be regarded as the total number of thiol groups in the resin composition.

The equivalent ratio (epoxy equivalent:thiol equivalent) of the thiol groups of all thiol compounds to the epoxy groups of the epoxy resin contained in the resin composition is preferably 1:0.5 to 1:1.5. In the resin composition, if the thiol equivalent is less than 0.5 equivalents or more than 1.5 equivalents relative to the epoxy equivalent of the epoxy resin contained in the resin composition, unreacted epoxy resin or thiol compound remains in the cured product, reducing the adhesive strength of the resin composition.

(C) Component: Amine Compound In the resin composition according to one embodiment of the present invention, the amine compound of the (C) component is preferably at least one amine compound selected from imidazole compounds, tertiary amine compounds, and amine adducts. The amine compound of the (C) component is preferably one that functions as a curing accelerator for epoxy resins. For example, the amine compound of the (C) component is preferably a compound that is an insoluble solid at room temperature and is solubilized by heating to function as a curing accelerator, and examples thereof include imidazole compounds that are solid at room temperature, tertiary amine compounds, and solid dispersion-type amine adduct-based latent curing accelerators, such as reaction products of amine compounds and epoxy compounds (amine-epoxy adduct-based latent curing accelerators), and reaction products of amine compounds and isocyanate compounds or urea compounds (urea-type adduct-based latent curing accelerators).

Examples of imidazole compounds include 2-heptadecylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-undecylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4-benzyl-5-hydroxymethylimidazole, 2,4-diamino-6-(2-methylimidazolyl-(1))-ethyl-S-triazine, and 2,4-diamino-6-(2'-methylimidazolyl-(1)')-ethyl-S-triazine isoform. Examples of the imidazole include, but are not limited to, cyanuric acid adduct, 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole-trimellitate, 1-cyanoethyl-2-phenylimidazole-trimellitate, N-(2-methylimidazolyl-1-ethyl)-urea, and N,N'-(2-methylimidazolyl-(1)-ethyl)-adiboyldiamide.

Tertiary amine compounds include, for example, amine compounds such as dimethylaminopropylamine, diethylaminopropylamine, di-n-propylaminopropylamine, dibutylaminopropylamine, dimethylaminoethylamine, diethylaminoethylamine, and N-methylpiperazine, and imidazole compounds such as 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, and 2-phenylimidazole. These compounds include primary or secondary amines having a tertiary amino group in the molecule; 2-dimethylaminoethanol, 1-methyl-2-dimethylaminoethanol, 1-phenoxymethyl-2-dimethylaminoethanol, 2-diethylaminoethanol, 1-butoxymethyl-2-dimethylaminoethanol, 1-(2-hydroxy-3-phenoxypropyl)-2-methylimidazole, 1-(2-hydroxy-3-phenoxypropyl)-2-ethyl-4-methylimidazole, and 1-(2-hydroxy-3-butoxypropyl)-2-methylimidazo 1-(2-hydroxy-3-butoxypropyl)-2-ethyl-4-methylimidazole, 1-(2-hydroxy-3-phenoxypropyl)-2-phenylimidazoline, 1-(2-hydroxy-3-butoxypropyl)-2-methylimidazoline, 2-(dimethylaminomethyl)phenol, 2,4,6-tris(dimethylaminomethyl)phenol, N-β-hydroxyethylmorpholine, 2-dimethylaminoethanethiol, 2-mercaptopyridine, 2-benzimidazole Examples of the tertiary amine compounds include alcohols, phenols, thiols, carboxylic acids, and hydrazides having a tertiary amino group in the molecule, such as 2-mercaptobenzimidazole, 2-mercaptobenzothiazole, 4-mercaptopyridine, N,N-dimethylaminobenzoic acid, N,N-dimethylglycine, nicotinic acid, isonicotinic acid, picolinic acid, N,N-dimethylglycine hydrazide, N,N-dimethylpropionic acid hydrazide, nicotinic acid hydrazide, and isonicotinic acid hydrazide. Examples of commercially available tertiary amine compounds include Fujicure FXR-1020 and Fujicure FXR-1020 (manufactured by T&K TOKA Corporation).

Examples of commercially available solid-dispersed amine adduct latent curing accelerators include Novacure HXA9322HP (manufactured by Asahi Kasei Corporation), Fujicure FXR-1121 (manufactured by T&K Toka Corporation), Amicure PN-23, and Amicure PN-F (manufactured by Ajinomoto Fine-Techno Co., Ltd.). For more detailed examples of solid-dispersed amine adduct latent curing agents or latent curing accelerators, the description in JP 2014-77024 A is incorporated by reference.

The content of the amine compound of component (C) contained in the resin composition varies depending on the type of amine compound. From the viewpoint of extending the pot life, the amount of the amine compound (C) contained in the resin composition is preferably 0.1 to 40 parts by mass, more preferably 0.5 to 35 parts by mass, and even more preferably 1.0 to 30 parts by mass, per 100 parts by mass of the epoxy resin contained in the resin composition. Note that some components (C) are provided in the form of a dispersion in which the component (C) is dispersed in an epoxy resin. When such a form of component (C) is used, the amount of the epoxy resin in which the component (C) is dispersed is also included in the amount of the epoxy resin (component (A) and epoxy resins other than component (A)) in the resin composition of the present invention.

(D) Component: Stabilizer The resin composition of one embodiment of the present invention may contain a stabilizer (D). By containing the stabilizer (D), the resin composition can improve the storage stability at room temperature (25°C) and extend the pot life. As the stabilizer (D), at least one selected from the group consisting of liquid boric acid ester compounds, aluminum chelates, and barbituric acids is preferred because it has a high effect of improving the storage stability at room temperature (25°C).

Examples of the liquid boric acid ester compound that can be used include 2,2'-oxybis(5,5'-dimethyl-1,3,2-oxaborinane), trimethyl borate, triethyl borate, tri-n-propyl borate, triisopropyl borate, tri-n-butyl borate, tripentyl borate, triallyl borate, trihexyl borate, tricyclohexyl borate, trioctyl borate, trinonyl borate, tridecyl borate, tridodecyl borate, trihexadecyl borate, trioctadecyl borate, tris(2-ethylhexyloxy)borane, bis(1,4,7,10-tetraoxaundecyl)(1,4,7,10,13-pentaoxatetradecyl)(1,4,7-trioxaundecyl)borane, tribenzyl borate, triphenyl borate, tri-o-tolyl borate, tri-m-tolyl borate, and triethanolamine borate.
The liquid borate ester compound contained as component (D) is preferred because it is liquid at room temperature (25° C.) and therefore the viscosity of the resin composition can be kept low.
When a liquid boric acid ester compound is contained in the resin composition as the component (D), the amount is preferably 0.01 to 5 parts by mass, more preferably 0.05 to 3 parts by mass, and even more preferably 0.1 to 1 part by mass, relative to 100 parts by mass of the resin composition.

As the aluminum chelate, for example, aluminum trisacetylacetonate (for example, ALA: Aluminum Chelate A, manufactured by Kawaken Fine Chemical Co., Ltd.) can be used.
When an aluminum chelate is contained as component (D), the amount is preferably 0.01 to 10 parts by mass, more preferably 0.05 to 5 parts by mass, and even more preferably 0.1 to 3 parts by mass, per 100 parts by mass of the resin composition.

When barbituric acid is included as component (D), it is preferable that the amount is 0.01 to 5 parts by mass, more preferably 0.05 to 3 parts by mass, and even more preferably 0.1 to 1 part by mass, per 100 parts by mass of the resin composition.

The resin composition of the present invention may further contain, as necessary, as other components (E), at least one additive selected from the group consisting of inorganic fillers such as silica, alumina, titania, magnesia, glass, talc, and calcium carbonate, organic fillers such as acrylic resin, silicone resin, polystyrene resin, and polydivinylbenzene, rubber fillers such as acrylonitrile-butadiene rubber (NBR) and styrene-butadiene rubber (SBR), flexibility agents such as carboxy-terminated butadiene nitrile rubber (CTBN) and polybutadiene, silane coupling agents, ion trapping agents, leveling agents, antioxidants, defoamers, and thixotropic agents. It may also contain a viscosity modifier, a flame retardant, or a solvent.

Manufacturing method of resin composition The resin composition of one embodiment of the present invention can be manufactured by adding and kneading the above-mentioned components (A) to (C) and, if necessary, the component (D). The manufacturing method of the resin composition is not particularly limited. For example, the resin composition according to this embodiment can be manufactured by mixing raw materials including the above-mentioned components (A) to (C) and, if necessary, the component (D) with a mixer such as a raikai machine, a pot mill, a three-roll mill, a hybrid mixer, a rotary mixer, or a twin-shaft mixer. These components may be mixed simultaneously, or some of them may be mixed first and the rest may be mixed later. In addition, the above-mentioned devices may be used in appropriate combination.

Adhesive The adhesive of one embodiment of the present invention uses the above-mentioned resin composition. The adhesive of one embodiment of the present invention can be cured at low temperatures, and can obtain a cured product with excellent stress relaxation without impairing physical properties. For example, when two parts with different thermal expansion coefficients are joined using the adhesive of one embodiment of the present invention, even if the parts are thermally deformed due to changes in the surrounding temperature, the adhesive has flexibility that can follow the thermal deformation of the parts. Specific heat curing conditions are, for example, 60°C or higher and 120°C or lower.

Sealing material The sealing material of one embodiment of the present invention uses the above-mentioned resin composition. The sealing material of one embodiment of the present invention can be cured at low temperatures, and can obtain a cured product with excellent stress relaxation without impairing physical properties. For example, when the gap between two parts is sealed using the sealing material of one embodiment of the present invention, even if the parts are thermally deformed due to changes in the ambient temperature, the sealing material has flexibility that can follow the thermal deformation of the parts. Specific heat curing conditions are, for example, 60°C or higher and 120°C or lower.

Image Sensor Module An image sensor module according to one embodiment of the present invention is formed using an adhesive or a sealant containing the above-mentioned resin composition. The image sensor module also includes a camera module for a mobile phone or a smartphone. The resin composition according to one embodiment of the present invention can be cured at a low temperature and can provide a cured product with excellent stress relaxation without impairing physical properties, and therefore can be suitably used as a resin composition contained in an adhesive or a sealant used in the assembly of an image sensor module that requires curing at a low temperature of about 80°C.

Semiconductor Device A semiconductor device according to one embodiment of the present invention is formed using an adhesive or a sealant containing the resin composition described above. The semiconductor device refers to devices in general that can function by utilizing semiconductor properties, and includes electronic components, semiconductor circuits, modules incorporating these, and electronic devices. The resin composition according to one embodiment of the present invention can be cured at a low temperature of about 80° C., and can obtain a cured product with excellent stress relaxation without impairing physical properties, and can therefore be suitably used as a resin composition contained in an adhesive or sealant used in the assembly of an image sensor module that requires curing at a low temperature.

The present invention will be described in detail below with reference to examples. The present invention is not limited to these examples.

Examples and Comparative Examples Resin compositions were prepared by mixing the components according to the ratios shown in Tables 1 to 3 below. In the tables below, the figures showing the mixing ratios of components (A) to (E) all indicate parts by mass. The components in Tables 1 to 3 are as follows.

Epoxy Resin Component (A): Epoxy resin not containing an aromatic ring (A1) YX8000: hydrogenated bisphenol A type epoxy resin, manufactured by Mitsubishi Chemical Corporation, weight average molecular weight 410, epoxy equivalent: 205 g/eq.
(A2) YX7400: an epoxy resin represented by general formula (A-1-1), in which x in general formula (A-1-1) is 10.3, manufactured by Mitsubishi Chemical Corporation, weight average molecular weight: 870, epoxy equivalent: 435 g/eq.
(A3) CDMDG: 1,4-cyclohexanedimethanol diglycidyl ether, manufactured by Showa Denko K.K., weight average molecular weight: 264, epoxy equivalent: 132 g/eq.
(A4) ADEKALYZER (registered trademark) BF1000: epoxy-modified polybutadiene (1,2-polybutadiene whose side chains are epoxidized), manufactured by ADEKA Corporation, weight average molecular weight: 1,500, epoxy equivalent: 178 g/eq.
(A5) TSL9906: an epoxy resin represented by general formula (A-2), in which R ⁶ to R ⁹ are methyl groups, manufactured by Momentive Performance Materials, Inc., weight average molecular weight 296, epoxy equivalent 181 g/eq.
Component (A'): epoxy resin containing an aromatic ring. (A'6) EXA-850CRP (EPICLON): bisphenol A type epoxy resin, DIC Corporation, weight average molecular weight: 344, epoxy equivalent: 172 g/eq.

Thiol Compound Component (B): Bifunctional Thiol Compound (B1) Thiol Compound 1: Bifunctional thiol compound represented by general formula (B-1-1), manufactured by Shikoku Chemical Industry Co., Ltd., molecular weight 389, thiol equivalent: 211 g/eq.
(B2) Thiol compound 2: a bifunctional thiol compound represented by general formula (B-2-1), manufactured by Shikoku Chemical Industry Co., Ltd., molecular weight 445, thiol equivalent: 243 g/eq.
(B3) Thiol compound 3: a bifunctional thiol compound represented by general formula (B-3-1), manufactured by Shikoku Chemical Industry Co., Ltd., molecular weight: 286, thiol equivalent: 159 g/eq.
(B') Thiol compounds other than component (B) (B'4) 3,6-dioxa-1,8-octanedithiol (1,8-dimercapto-3,6-dioxaoctane): manufactured by Tokyo Chemical Industry Co., Ltd., molecular weight 182, thiol equivalent 91 g/eq.
(B'5) 1,10-decanedithiol: manufactured by Tokyo Chemical Industry Co., Ltd., molecular weight 206, thiol equivalent 103 g/eq.
(B'6) EPMG-4: tetraethylene glycol bis(3-mercaptopropionate), manufactured by SC Organic Chemical Co., Ltd., molecular weight 372, thiol equivalent 186 g/eq.
(B'7) PEMP: pentaerythritol tetrakis(3-mercaptopropionate) (PEMP), manufactured by SC Organic Chemicals Co., Ltd., molecular weight 489, thiol equivalent 122 g/eq.
(B'8) C3 TS-G: 1,3,4,6-tetrakis(3-mercaptopropyl)glycoluril, manufactured by Shikoku Chemical Industry Co., Ltd., molecular weight 432, thiol equivalent 114 g/eq.

Component (C): Amine compound (C1) HXA9322HP: solid dispersion type amine adduct latent curing accelerator (microencapsulated imidazole adduct), manufactured by Asahi Kasei Corporation, 1/3 by weight is microencapsulated imidazole adduct, 2/3 is a mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin, epoxy equivalent 180 g/eq.
(C2) FXR1121 (Fujicure): solid dispersion type amine adduct, manufactured by T&K TOKA Corporation.
(C3) FXR1020 (Fujicure), a tertiary amine compound, manufactured by T&K TOKA Corporation.

(D) Component: Stabilizer (D1) TIPB: triisopropyl borate, manufactured by Tokyo Chemical Industry Co., Ltd.

(E) Other Components (E1) SOE5: Silica filler, manufactured by Admatechs Co., Ltd.
(E2) KBM403: 3-glycidoxypropyltrimethoxysilane (silane coupling agent), manufactured by Shin-Etsu Chemical Co., Ltd.

Evaluation method Volatility The weight of a metal container with a diameter of 5 cm and a depth of 0.5 cm was measured. Approximately 1.0 g of a thiol compound was added to the container, and the container was left in an oven at 80°C for 1 hour without covering it. After cooling, the weight of the metal container was measured to measure the amount of volatilization from the thiol resin. As a result, the volatilization amount of 1,10-decanedithiol was 11%, the volatilization amount of 3,6-dioxa-1,8-octanedithiol was 27%, while the volatilization amount of the other thiol resins, including thiol compounds 1, 2, and 3, was all less than 1%.

Adhesive Strength The adhesive strength (shear strength) of the prepared resin composition was measured by the following procedure. The results are shown in the table below.
(1) A sample is stencil-printed on a 3 cm x 4 cm SUS (Steel Special Use Stainless Steel) 304 plate with a diameter of 2 mm.
(2) Place an alumina chip of 1.5 mm x 3 mm on the printed sample, and heat cure it at 80°C for 180 minutes using a blower dryer.
(3) The shear strength is measured using a benchtop universal testing machine (1605HTP manufactured by Aiko Engineering Co., Ltd.). The resin compositions of the examples and comparative examples having an adhesive strength of 90 N or more and 180 N or less are listed in Table 1. The resin compositions of the examples and comparative examples having an adhesive strength of less than 90 N are listed in Table 2. The resin compositions of the examples and comparative examples having an adhesive strength of more than 180 N are listed in Table 3.

Warpage To each of the epoxy resins shown in Tables 1 to 3, 0.6 parts of thixotropic agent R805 manufactured by Nippon Aerosil Co., Ltd. was added to suppress sagging, and the other components were mixed as shown in Tables 1 to 3 to prepare a resin composition. In the following table, the numbers indicating the blending ratio of components (A) to (E) all indicate parts by mass. The prepared resin composition was printed on a polyimide film (Kapton film: thickness 5 μm) manufactured by Toray DuPont Co., Ltd. with a square 2 cm x 2 cm, 125 μm thick stencil (made with Ube Industries, Ltd.'s Upilex film). After thermal curing at 80 ° C for 180 minutes, it was left overnight in an environment of 25 ° C. The part where the cured product was printed was cut out to prepare a sample of 2 cm x 2 cm. The convex surface was placed up, and the distance from the horizontal plane to the maximum height was measured with a measuring microscope as the amount of warpage. From the viewpoint of stress relaxation, the amount of warpage is preferably 4.0 mm or less.

Hydrolysis resistance When the resin composition contained a compound containing an ester bond, hydrolysis was performed under high temperature and high humidity, and the cured resins (samples for measuring the amount of warping) of the compositions of Comparative Examples 3 and 4 were placed under PCT conditions (121°C, 2 atm) for 10 hours, and the cured resins liquefied and had poor hydrolysis resistance. On the other hand, no abnormalities were observed in the appearance of the cured resins of the compositions of Examples 16 and 17.

The cured products obtained from the resin compositions of Examples 1 to 20 had good hydrolysis resistance and low volatility, and no voids were present in the cured products after curing.

As shown in Table 1, the cured products obtained from the resin compositions of Examples 1 to 11, in which the adhesive strength of the resin composition was 90N to 180N, had a warp of 2.1 mm or less, and warp was suppressed compared to Comparative Example 1. From this result, it was confirmed that the resin compositions of Examples 1 to 11 have small residual stress, and have flexibility that can follow the changes in the two parts even when the two parts expand and contract due to changes in the surrounding temperature after bonding two parts with different thermal expansion coefficients, and have excellent stress relaxation. On the other hand, the cured product obtained from the resin composition of Comparative Example 1, in which the adhesive strength of the resin composition was 90N to 180N, had a warp of more than 2.1 mm. In addition, the thiol compound contained in the resin composition of Comparative Example 1 has a small molecular weight and is volatile, so that bubbles are generated in the resin composition during curing, and voids exist in the obtained cured product. It should be noted that Examples 5 and 11 are examples in which an epoxy resin containing an aromatic ring is used in combination, and both adhesive strength and warp suppression were good.

As shown in Table 2, the cured products obtained from the resin compositions of Examples 12 to 14, in which the adhesive strength of the resin composition was less than 90N, had a warp of 1.2 mm or less, and warp was suppressed compared to Comparative Examples 2 and 3. From this result, it was confirmed that the resin composition had a small residual stress, and even if two parts with different thermal expansion coefficients were bonded together and the two parts expanded and contracted due to changes in the surrounding temperature, it had flexibility that could follow the changes in the two parts, and had excellent stress relaxation. On the other hand, the cured products obtained from the resin compositions of Comparative Examples 2 and 3, in which the adhesive strength of the resin composition was less than 90N, had a warp of more than 1.2 mm. In addition, the thiol compound contained in the resin composition of Comparative Example 2 had a small molecular weight and was volatile, and bubbles were generated in the resin composition during curing, and voids were present in the obtained cured product. The thiol compound contained in the resin composition of Comparative Example 3 was likely to be hydrolyzed because it contained an ester bond, and it was predicted that the adhesive strength would decrease under high temperature and high humidity. In addition, Example 14 is an example in which two types of (A) components were used in combination, but both the adhesive strength and the suppression of warp were good.

As shown in Table 3, the cured products obtained from the resin compositions of Examples 15 to 20, in which the adhesive strength of the resin composition exceeds 180 N, had a warp of less than 4.0 mm, and the warp was suppressed compared to Comparative Examples 4 and 5. From this result, it was confirmed that the residual stress was small, and even if the two parts with different thermal expansion coefficients were bonded together and the two parts expanded or contracted due to a change in the surrounding temperature, the cured products had flexibility that could follow the changes in the two parts, and had excellent stress relaxation. On the other hand, the cured products obtained from the resin compositions of Comparative Examples 4 and 5, in which the adhesive strength of the resin composition exceeded 180 N, had a large warp of more than 4.0 mm. From this result, it was predicted that the cured products obtained from the resin compositions of Comparative Examples 4 and 5 had residual stress, and did not have flexibility that could follow the changes in the two parts due to the influence of temperature when the two parts were bonded together. In addition, since the thiol compound contained in the resin composition of Comparative Example 5 contains an ester bond, it was highly likely to be hydrolyzed, and it was predicted that the adhesive strength would decrease under high temperature and high humidity. In addition, Examples 16 to 19 are examples in which the component (B) and a thiol compound other than the component (B) were used in combination, and both the adhesive strength and the suppression of warping were good.

Claims (11)

(A) an epoxy resin not containing an aromatic ring;
(B) at least one bifunctional thiol compound selected from the group consisting of bifunctional thiol compounds represented by the following general formulas (B-1), (B-2), (B-3), (B-4), and (B-5) having a molecular weight of 210 or more and 1,000 or less;
(C) an amine compound (excluding selenium atoms and organic solvents).

(In general formula (B-1), n and m each independently represent an integer of 1 to 3.)

(In general formula (B-2), R ¹ , R ² , R ³ and R ⁴ are each independently a hydrogen atom or a group represented by the following general formula (b-1). However, one of R ¹ and R ² is a group represented by the following general formula (b-1), and one of R ³ and R ⁴ is a group represented by the following general formula (b-1).)

(In general formula (b-1), r is an integer of 1 to 3.)

(In general formula (B-3), G ₁ and G ₂ each independently represent -O- or -CH ₂ -, provided that at least one of G ₁ and G ₂ is -O-, and p and q each independently represent an integer of 2 to 5.)

(In general formula (B-4), s and t each independently represent an integer of 3 or 4.)

(In general formula (B-5), u and v each independently represent an integer of 3 or 4.) The resin composition according to claim 1 , wherein the weight average molecular weight of the component (A) is 240 to 1,000. The resin composition according to claim 1 or 2 , wherein the component (A) is an epoxy resin represented by the following formula (A-1) or (A-2):

(In formula (A-1), ^R5 is a linear or branched alkylene group having 1 to 15 carbon atoms, and w is an integer of 1 to 20.)

(In formula (A-2), R ⁶ to R ⁹ each independently represent a linear or branched alkyl group having 1 to 3 carbon atoms.) The resin composition according to any one of claims 1 to 3 , wherein the amine compound of the component (C) is at least one amine compound selected from the group consisting of imidazole compounds, tertiary amine compounds, and amine adducts. The resin composition according to any one of claims 1 to 4 , wherein the total number of thiol groups of the bifunctional thiol compound of the component (B) is 20 to 100 when the total number of thiol groups in the resin composition is 100. The resin composition according to claim 1 , further comprising (D) a stabilizer. 7. The resin composition according to claim 6 , wherein the stabilizer of component (D) is at least one selected from the group consisting of liquid boric acid ester compounds, aluminum chelates, and barbituric acids. An adhesive comprising the resin composition according to any one of claims 1 to 7 . An encapsulant comprising the resin composition according to any one of claims 1 to 7 . An image sensor module manufactured using the adhesive according to claim 8 or the sealing material according to claim 9 . A semiconductor device manufactured using the adhesive according to claim 8 or the sealing material according to claim 9 .