Curable resin composition and electronic component device

Abstract

This curable resin composition contains an epoxy resin. A cured product of the curable resin composition exhibits an adhesive strength of 0.40 MPa or more with respect to AgCu at 260°C after being heated and humidified for 168 hours at 85°C and 85% RH.

Description

Curable resin composition and electronic component device

[0001] The present disclosure relates to a curable resin composition and an electronic component device.

[0002] In recent years, semiconductor elements have become increasingly densely packed. Accordingly, surface-mounted packages have become the mainstream for resin-sealed semiconductor devices, replacing conventional pin-insertion packages. Surface-mounted ICs (Integrated Circuits), LSIs (Large Scale Integration), and the like are being packaged in thin, compact packages to increase packaging density and reduce packaging height. As a result, the area occupied by the elements in the package has increased, and the thickness of the package has become extremely thin.

[0003] Furthermore, these packages differ in their mounting method from pin-insertion packages. Pin-insertion packages are soldered from the backside of the wiring board after pins are inserted into the board, preventing direct exposure to high temperatures. However, surface-mount ICs are temporarily attached to the surface of the wiring board and then processed using a solder bath or reflow device, exposing the package directly to soldering temperatures (reflow temperatures). As a result, if the package absorbs moisture, the absorbed moisture vaporizes during reflow, and the resulting vapor pressure acts as peel stress, causing peeling between the encapsulant and supporting members such as the chip or lead frame, resulting in package cracks and poor electrical characteristics. Therefore, there is a need for an encapsulating material that has excellent adhesion to supporting members and, ultimately, excellent solder heat resistance (reflow resistance).

[0004] As an encapsulating material having excellent reflow resistance, a curable resin composition containing an epoxy resin, a curing agent, a curing accelerator, an inorganic filler, and an alkoxysilane polymer having a specific structure has been proposed in Patent Document 1. In addition, in order to improve reflow resistance, for example, the surface of a lead frame has been roughened before plating treatment to improve adhesion to the encapsulating material.

[0005] Japanese Patent Application Laid-Open No. 2008-111101

[0006] There is a need for the development of an encapsulating material that is inhibited from peeling off from a lead frame even under more severe moisture absorption conditions (for example, moisture absorption conditions of 85°C and 85% RH). The present disclosure has been made in view of the above circumstances, and aims to provide a curable resin composition that is inhibited from peeling off from a lead frame even when a cured product is subjected to moisture absorption under conditions of 85°C and 85% RH, and an electronic component device including an element encapsulated with this curable resin composition.

[0007] <1> A curable resin composition comprising an epoxy resin, wherein the cured product has an adhesive strength of 0.40 MPa or more at 260°C to AgCu after heating and humidifying for 168 hours at 85°C and 85% RH. <2> The curable resin composition according to <1>, further comprising a curing agent, wherein the equivalent ratio of the curing agent to the epoxy resin, curing agent / epoxy resin, is 0.8 or less. <3> The curable resin composition according to <1> or <2>, wherein the cured product has a glass transition temperature of greater than 110°C. <4> The curable resin composition according to any one of <1> to <3>, wherein the cured product has a thermal expansion coefficient α2 measured at 180°C to 200°C of 32.0 ppm / °C or more. <5> The curable resin composition according to any one of <1> to <4>, wherein the epoxy resin comprises at least one selected from the group consisting of a triphenylmethane-type epoxy resin containing a t-Bu group and a biphenyl-type epoxy resin. <6> The curable resin composition according to any one of <1> to <5>, further comprising an inorganic filler. <7> An electronic component device comprising: an element; and a cured product of the curable resin composition according to any one of <1> to <6>, encapsulating the element. <8> The electronic component device according to <7>, further comprising a lead frame on one surface of which the element is mounted. <9> The electronic component device according to <8>, wherein the lead frame contains Ag.

[0008] According to the present disclosure, it is possible to provide a curable resin composition that suppresses peeling from a lead frame even when the cured product is subjected to moisture absorption under conditions of 85°C and 85% RH, and an electronic component device including an element encapsulated with this curable resin composition.

[0009] Hereinafter, embodiments for carrying out the present disclosure will be described in detail. However, the present disclosure is not limited to the following embodiments. In the following embodiments, components (including element steps, etc.) are not essential unless otherwise specified. The same applies to numerical values ​​and their ranges, and do not limit the present disclosure.

[0010] In the present disclosure, numerical ranges indicated using "to" include the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In numerical ranges described in stages in the present disclosure, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another staged numerical range. Furthermore, in numerical ranges described in the present disclosure, the upper or lower limit value of that numerical range may be replaced with a value shown in a synthesis example. In the present disclosure, each component may contain multiple corresponding compounds. When multiple substances corresponding to each component are present in the composition, the content or amount of each component means the total content or amount of the multiple substances present in the composition, unless otherwise specified. In the present disclosure, each component may contain multiple types of particles. When multiple types of particles corresponding to each component are present in the composition, the particle size of each component means the value for a mixture of the multiple types of particles present in the composition, unless otherwise specified. In the present disclosure, the term "laminated" refers to stacking layers, and two or more layers may be bonded or detachable. In the notation of groups (atomic groups) in the present disclosure, notations that do not specify whether they are substituted or unsubstituted include those that have a substituent as well as those that do not have a substituent. In the present disclosure, the number of structural units represents an integer value for a single molecule, but represents a rational number that is an average value for an aggregate of multiple types of molecules. In the present disclosure, the number of carbon atoms means the total number of carbon atoms contained in an entire group, and when the group does not have a substituent, it represents the number of carbon atoms that form the skeleton of the group, and when the group has a substituent, it represents the total number obtained by adding the number of carbon atoms that form the skeleton of the group to the number of carbon atoms in the substituent.

[0011] In the present disclosure, the weight average molecular weight (Mw) is a value measured using the following GPC measurement apparatus under the following measurement conditions and converted using a calibration curve of standard polystyrene. However, for compounds whose Mw cannot be accurately measured by GPC due to their small molecular weight, the molecular weight determined from the chemical structure of the compound is used as the Mw, Mn, or degree of polymerization of the compound. Examples of measurement apparatus include the following, and a five-sample set ("PStQuick MP-H" and "PStQuick B", manufactured by Tosoh Corporation) may be used as standard polystyrene to create the calibration curve.

[0012] (GPC measurement device) GPC device: High-speed GPC device "HCL-8320GPC", detector is differential refractometer or UV, manufactured by Tosoh Corporation Column: Column TSKgel SuperMultipore HZ-H (column length: 15 cm, column inner diameter: 4.6 mm), manufactured by Tosoh Corporation (Measurement conditions) Solvent: tetrahydrofuran (THF) Measurement temperature: 40°C Flow rate: 0.35 mL / min Sample concentration: 10 mg / 5 mL THF Injection amount: 20 μL

[0013] <Curable Resin Composition> The curable resin composition of the present disclosure contains an epoxy resin, and the adhesive strength of the cured product to AgCu at 260°C after heating and humidifying at 85°C and 85% RH for 168 hours is 0.40 MPa or more.

[0014] The curable resin composition of the present disclosure has the aforementioned adhesive strength of 0.40 MPa or more, and therefore peeling from the lead frame is suppressed even when the cured product is subjected to moisture absorption for 168 hours under conditions of 85°C and 85% RH, making it possible to significantly reduce the rate at which the cured product peels from the lead frame relative to the number of packages.

[0015] (Epoxy Resin) The curable resin composition of the present disclosure contains an epoxy resin. The epoxy resin may be used alone or in combination of two or more types.

[0016] Examples of epoxy resins include novolac epoxy resins (phenol novolac epoxy resins, orthocresol novolac epoxy resins, etc.) obtained by epoxidizing novolac resins obtained by condensing or co-condensing, under an acid catalyst, at least one phenolic compound selected from the group consisting of phenolic compounds such as phenol, cresol, xylenol, resorcinol, catechol, bisphenol A, bisphenol F, and naphthol compounds such as α-naphthol, β-naphthol, and dihydroxynaphthalene with an aliphatic aldehyde compound such as formaldehyde, acetaldehyde, and propionaldehyde; triphenylmethane epoxy resins obtained by epoxidizing triphenylmethane phenolic resins obtained by condensing or co-condensing, under an acid catalyst, the above-mentioned phenolic compounds with aromatic aldehyde compounds such as benzaldehyde and salicylaldehyde; and epoxidized novolac resins obtained by co-condensing, under an acid catalyst, the above-mentioned phenolic compounds and naphthol compounds with an aldehyde compound. diphenylmethane-type epoxy resins which are diglycidyl ethers of bisphenol A, bisphenol F, or the like; biphenyl-type epoxy resins which are diglycidyl ethers of alkyl-substituted or unsubstituted biphenols; stilbene-type epoxy resins which are diglycidyl ethers of stilbene-based phenolic compounds; sulfur-containing epoxy resins which are diglycidyl ethers of bisphenol S, or the like; epoxy resins which are glycidyl ethers of alcohols such as butanediol, polyethylene glycol, and polypropylene glycol; glycidyl ester-type epoxy resins which are glycidyl esters of polycarboxylic acids such as phthalic acid, isophthalic acid, and tetrahydrophthalic acid; glycidylamine-type epoxy resins in which active hydrogen atoms bonded to nitrogen atoms of aniline, diaminodiphenylmethane, isocyanuric acid, or the like are substituted with glycidyl groups; and dicyclopentadiene-type epoxy resins obtained by epoxidizing a co-condensation resin of dicyclopentadiene and a phenolic compound.Alicyclic epoxy resins such as vinylcyclohexene diepoxide, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, and 2-(3,4-epoxy)cyclohexyl-5,5-spiro(3,4-epoxy)cyclohexane-m-dioxane, which are produced by epoxidizing an intramolecular olefin bond; paraxylylene-modified epoxy resins, which are glycidyl ethers of paraxylylene-modified phenolic resins; metaxylylene-modified epoxy resins, which are glycidyl ethers of metaxylylene-modified phenolic resins; terpene-modified epoxy resins, which are glycidyl ethers of terpene-modified phenolic resins; and dicyclopentadiene-modified phenolic resins, which are glycidyl ethers of dicyclopentadiene-modified phenolic resins. Examples of the epoxy resin include pentadiene-modified epoxy resins, cyclopentadiene-modified epoxy resins which are glycidyl ethers of cyclopentadiene-modified phenolic resins, polycyclic aromatic ring-modified epoxy resins which are glycidyl ethers of polycyclic aromatic ring-modified phenolic resins, naphthalene-type epoxy resins which are glycidyl ethers of naphthalene ring-containing phenolic resins, halogenated phenol novolac-type epoxy resins, hydroquinone-type epoxy resins, trimethylolpropane-type epoxy resins, linear aliphatic epoxy resins obtained by oxidizing olefin bonds with peracids such as peracetic acid, and aralkyl-type epoxy resins obtained by epoxidizing aralkyl-type phenolic resins such as phenol aralkyl resins and naphthol aralkyl resins. Furthermore, aminophenol-type epoxy resins which are glycidyl ethers of aminophenols are also included as epoxy resins.

[0017] The epoxy resin preferably contains at least one selected from the group consisting of triphenylmethane-type epoxy resins and biphenyl-type epoxy resins, and more preferably contains at least one selected from the group consisting of triphenylmethane-type epoxy resins containing a t-Bu group (t-butyl group) and biphenyl-type epoxy resins.

[0018] The epoxy resin preferably contains a triphenylmethane type epoxy resin, from the viewpoint of preventing the cured product of the curable resin composition from peeling off from a support member (for example, a support member containing AgCu).

[0019] The triphenylmethane-type epoxy resin preferably contains an epoxy resin having at least one selected from the group consisting of an alkyl group and an alkoxy group (hereinafter also referred to as a specific triphenylmethane-type epoxy resin). When the triphenylmethane-type epoxy resin contains at least one selected from the group consisting of an alkyl group and an alkoxy group, the monomer becomes bulky and the molecular weight of the monomer increases, resulting in a polymer with increased intermolecular distance and low crosslink density after polymerization. This results in fewer molecules per unit volume, which makes the molecules more likely to dissolve when tensile stress is applied, which is expected to reduce the elastic modulus and increase the linear expansion coefficient of the cured product of the curable resin composition. As a result, the stress (a combination of strain, elastic modulus, linear expansion difference, and temperature difference) caused by the linear expansion difference between support members is reduced and can be reduced to below the adhesive strength of the resin, thereby preventing the cured product of the curable resin composition from peeling from the support member. This is also expected to further improve reflow resistance.

[0020] The alkyl group contained in the specific triphenylmethane epoxy resin preferably has a carbon number of 1 to 20, more preferably 1 to 16, and even more preferably 1 to 10. The alkyl group may be linear, branched, or cyclic, but at least one alkyl group is preferably branched and preferably contains a t-butyl group.

[0021] The alkoxy group contained in the specific triphenylmethane type epoxy resin preferably has 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and even more preferably 1 to 10 carbon atoms. The alkoxy group may be linear, branched, or cyclic.

[0022] The benzene ring contained in the specific triphenylmethane type epoxy resin preferably has two or more alkyl groups, and more preferably has two or more alkyl groups in the main chain. At least one of the two or more alkyl groups contained in the benzene ring is preferably a branched alkyl group, and the branched alkyl group is preferably located at the ortho position relative to the glycidyloxy group.

[0023] The specific triphenylmethane type epoxy resin may be an epoxy resin represented by the following formula (1):

[0024]

[0025] In formula (1), each R independently represents an alkyl group or an alkoxy group, each i independently represents an integer of 1 to 3, and each k independently represents an integer of 0 to 4. n is an average value and represents a number of 0 to 10.

[0026] Examples of the alkyl group and alkoxy group represented by R include those described above. i represents an integer of 1 to 3, preferably 2 or 3, and more preferably 2. When i is 2, at least one of the R groups represented by the subscript i is preferably a branched alkyl group, more preferably a combination of a branched alkyl group and a linear alkyl group, such as a combination of a t-butyl group and a methyl group. The t-butyl group and the methyl group may be located at any position on the benzene ring, but the t-butyl group is preferably located at the ortho position relative to the glycidyloxy group. Furthermore, the positional relationship between the t-butyl group and the methyl group may be any, and they may be located at any of the ortho, meta, and para positions. Each k independently represents an integer of 0 to 4, preferably 0.

[0027] A specific example of the specific triphenylmethane type epoxy resin is an epoxy resin represented by the following formula (2).

[0028] n is the average value and represents a number from 0 to 10.

[0029] The content of the specific triphenylmethane type epoxy resin is preferably 50% by mass to 100% by mass, more preferably 70% by mass to 100% by mass, and even more preferably 90% by mass to 100% by mass, based on the total amount of triphenylmethane type epoxy resins.

[0030] Among the above epoxy resins, it is preferable to contain a biphenyl-type epoxy resin from the viewpoint of the adhesiveness of the curable resin composition of the present disclosure to the lead frame and the balance between heat resistance and fluidity.

[0031] The biphenyl-type epoxy resin is not particularly limited as long as it is an epoxy resin having a biphenyl skeleton. For example, an epoxy resin represented by the following general formula (II) is preferred.

[0032]

[0033] In formula (II), R ８ represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or an aromatic group having 4 to 18 carbon atoms, and may be the same or different from each other. n is an average value and represents a number from 0 to 10.

[0034] The stilbene epoxy resin is not particularly limited as long as it is an epoxy resin having a stilbene skeleton. For example, an epoxy resin represented by the following general formula (III) is preferred.

[0035]

[0036] In formula (III), R ９ and R １０ represents a hydrogen atom or a monovalent organic group having 1 to 18 carbon atoms, and may be the same or different from each other. n is an average value and represents a number from 0 to 10.

[0037] The diphenylmethane type epoxy resin is not particularly limited as long as it is an epoxy resin having a diphenylmethane skeleton. For example, an epoxy resin represented by the following general formula (IV) is preferred.

[0038]

[0039] In formula (IV), R １１ and R １２ represents a hydrogen atom or a monovalent organic group having 1 to 18 carbon atoms, and may be the same or different from each other. n is an average value and represents a number from 0 to 10.

[0040] The sulfur atom-containing epoxy resin is not particularly limited as long as it is an epoxy resin containing a sulfur atom, and examples thereof include epoxy resins represented by the following general formula (V):

[0041]

[0042] In formula (V), R１３ represents a hydrogen atom or a monovalent organic group having 1 to 18 carbon atoms, and may be the same or different from each other. n is an average value and represents a number from 0 to 10.

[0043] The novolac epoxy resin is not particularly limited as long as it is an epoxy resin obtained by epoxidizing a novolac phenolic resin, and examples thereof include epoxy resins represented by the following general formula (VI):

[0044]

[0045] In formula (VI), R １４ represents a hydrogen atom or a monovalent organic group having 1 to 18 carbon atoms, and may be the same or different. １５ represents a monovalent organic group having 1 to 18 carbon atoms, and may be the same or different. Each i independently represents an integer of 0 to 3. n is an average value and represents a number of 0 to 10.

[0046] The dicyclopentadiene-type epoxy resin is not particularly limited as long as it is an epoxy resin obtained by epoxidizing a compound having a dicyclopentadiene skeleton as a raw material. For example, an epoxy resin represented by the following general formula (VII) can be mentioned.

[0047]

[0048] In formula (VII), R １６ represents a monovalent organic group having 1 to 18 carbon atoms, and may be the same or different. Each i independently represents an integer of 0 to 3. n is an average value and represents a number of 0 to 10.

[0049] The copolymerized epoxy resin obtained by epoxidizing a novolak resin obtained from a naphthol compound, a phenol compound, and an aldehyde compound is not particularly limited as long as it is an epoxy resin made from a compound having a naphthol skeleton and a compound having a phenol skeleton as raw materials. For example, an epoxy resin represented by the following general formula (IX) can be mentioned.

[0050]

[0051] In formula (IX), R １９ ~R ２１represents a monovalent organic group having 1 to 18 carbon atoms, and may all be the same or different. Each i independently represents an integer of 0 to 3, each j independently represents an integer of 0 to 2, and each k independently represents an integer of 0 to 4. Each l and m represents an average value and is a number of 0 to 10, and (l + m) is a number of 0 to 10. The terminal of the epoxy resin represented by formula (IX) is either formula (IX-1) or (IX-2) below. In formulas (IX-1) and (IX-2), R １９ ~R ２１ , i, j and k are defined as R １９ ~R ２１ , i, j and k are defined the same way. n is 1 (when bonding via a methylene group) or 0 (when bonding not via a methylene group).

[0052]

[0053] Examples of the epoxy resin represented by the general formula (IX) include random copolymers containing l structural units and m structural units randomly, alternating copolymers containing them alternately, copolymers containing them regularly, block copolymers containing them in block form, etc. Any of these may be used alone or in combination of two or more.

[0054] Another preferred copolymerized epoxy resin is Epiclon HP-5000 (trade name, DIC Corporation), a methoxynaphthalene-cresol-formaldehyde co-condensed epoxy resin containing the following two structural units in a random, alternating, or block order. For example, an epoxy resin represented by the following general formula is included: In the following general formula, n and m each represent an average value and are numbers from 0 to 10, and (n+m) represents a number from 0 to 10, preferably n and m each represent an average value and are numbers from 1 to 9, and (n+m) represents a number from 2 to 10.

[0055]

[0056] The aralkyl epoxy resin is not particularly limited as long as it is an epoxy resin made from a phenolic resin synthesized from at least one selected from the group consisting of phenolic compounds such as phenol and cresol and naphthol compounds such as naphthol and dimethylnaphthol, and dimethoxyparaxylene, bis(methoxymethyl)biphenyl or a derivative thereof. For example, an epoxy resin obtained by glycidyl etherifying a phenolic resin synthesized from at least one selected from the group consisting of phenolic compounds such as phenol and cresol and naphthol compounds such as naphthol and dimethylnaphthol, and dimethoxyparaxylene, bis(methoxymethyl)biphenyl or a derivative thereof is preferred, and epoxy resins represented by the following general formulas (X) and (XI) are more preferred.

[0057]

[0058] In formulas (X) and (XI), R ３８ represents a hydrogen atom or a monovalent organic group having 1 to 18 carbon atoms, and may be the same or different. ３７ , R ３９ ~R ４１ represents a monovalent organic group having 1 to 18 carbon atoms, and may be the same or different. Each i is independently an integer of 0 to 3, each j is independently an integer of 0 to 2, each k is independently an integer of 0 to 4, and each 1 is independently an integer of 0 to 4. Each n is an average value and is independently a number of 0 to 10.

[0059] R in the above general formulas (II) to (VII), (IX) to (XI) ８ ~R ２１ and R ３７ ~R ４１ With regard to the formula (II), "all of them may be the same or different" means, for example, that 8 to 88 R ８ It means that all of the R may be the same or different. ９ ~R ２１ and R ３７ ~R ４１ In addition, the numbers of R may all be the same or different.８ ~R ２１ and R ３７ ~R ４１ may be the same or different. For example, R ９ and R １０ may be the same or different. In addition, the monovalent organic group having 1 to 18 carbon atoms in the general formulae (III) to (VII) and (IX) to (XI) is preferably an alkyl group or an aryl group.

[0060] In the general formulas (II) to (VII) and (IX) to (XI), n is an average value, and each independently is preferably in the range of 0 to 10. When n is 10 or less, the melt viscosity of the resin component does not become too high, and the viscosity of the curable resin composition during melt molding tends to decrease, and the occurrence of filling defects, deformation of bonding wires (gold wires connecting elements to leads), etc. tends to be suppressed. It is more preferable that n is set in the range of 0 to 4.

[0061] The epoxy equivalent of the epoxy resin is not particularly limited. From the viewpoint of a balance of various properties such as moldability, heat resistance, and electrical reliability, the epoxy equivalent of the epoxy resin is preferably 40 g / eq to 1000 g / eq, more preferably 45 g / eq to 500 g / eq, and even more preferably 50 g / eq to 350 g / eq. The epoxy equivalent of the epoxy resin is a value measured by a method in accordance with JIS K 7236:2009.

[0062] The epoxy resin may be solid or liquid at 25°C. When the epoxy resin is solid at 25°C, the softening point or melting point of the epoxy resin is not particularly limited. From the viewpoint of the balance between moldability and heat resistance, the softening point or melting point of the epoxy resin is preferably 40°C to 180°C. Furthermore, from the viewpoint of handleability during the production of the curable resin composition, the softening point or melting point of the epoxy resin is preferably 50°C to 130°C. In the present disclosure, the softening point refers to a value measured by the ring and ball method of JIS K 7234:1986. In the present disclosure, the melting point refers to a value measured in accordance with the visual method of JIS K 0064:1992.

[0063] From the viewpoint of a balance between moldability and heat resistance, the Mw of the epoxy resin is preferably 550 to 1,050, and more preferably 650 to 950.

[0064] The proportion of the triphenylmethane epoxy resin in the curable resin composition relative to 100 parts by mass of the total amount of epoxy resins is preferably 15 parts by mass or more, more preferably 20 parts by mass or more, and even more preferably 25 parts by mass or more. The upper limit of this proportion is not particularly limited, and may be 95 parts by mass or less, 90 parts by mass or less, 85 parts by mass or less, or 50 parts by mass or less.

[0065] The proportion of the biphenyl epoxy resin relative to 100 parts by mass of the total amount of epoxy resins in the curable resin composition is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and even more preferably 15 parts by mass or more. The upper limit of this proportion is not particularly limited, and may be 50 parts by mass or less, 40 parts by mass or less, or 30 parts by mass or less.

[0066] The total content of the epoxy resin in the curable resin composition is preferably 0.5% by mass to 60% by mass, more preferably 2% by mass to 50% by mass, and even more preferably 3% by mass to 45% by mass, from the viewpoints of strength, fluidity, heat resistance, moldability, and the like.

[0067] (Curing Agent) The curable resin composition of the present disclosure preferably contains a curing agent. The type of curing agent is not particularly limited and can be selected from those commonly used as components of curable resin compositions. The curing agent may be used alone or in combination of two or more types. In the present disclosure, the curing agent may be any agent that has a structure that can react with the epoxy resin contained in the curable resin composition and cure the curable resin composition, and even compounds that are contained in small amounts and contribute little to the curing reaction of the curable resin composition are considered to be included in the curing agent.

[0068] Examples of the curing agent include a phenol-based curing agent, an amine-based curing agent, an acid anhydride-based curing agent, a polymercaptan-based curing agent, a polyaminoamide-based curing agent, an isocyanate-based curing agent, and a blocked isocyanate-based curing agent. Among these, from the viewpoint of heat resistance, a phenol-based curing agent or an amine-based curing agent is preferred. Furthermore, from the viewpoint of adhesion of the curable resin composition of the present disclosure to a lead frame and heat resistance, a phenol-based curing agent is preferred.

[0069] Examples of phenolic curing agents include phenolic resins and polyhydric phenolic compounds having two or more phenolic hydroxyl groups per molecule. Specific examples include polyhydric phenolic compounds such as resorcinol, catechol, bisphenol A, bisphenol F, and substituted or unsubstituted biphenols; novolac phenolic resins obtained by condensing or co-condensing at least one phenolic compound selected from the group consisting of phenolic compounds such as phenol, cresol, xylenol, resorcinol, catechol, bisphenol A, bisphenol F, phenylphenol, and aminophenol, and naphthol compounds such as α-naphthol, β-naphthol, and dihydroxynaphthalene, with an aldehyde compound such as formaldehyde, acetaldehyde, or propionaldehyde, under an acidic catalyst; and phenolic resins synthesized from the above phenolic compounds and dimethoxyparaxylene, bis(methoxymethyl)biphenyl, or the like. Examples of the phenolic curing agent include aralkyl-type phenolic resins such as nol aralkyl resins and naphthol aralkyl resins; paraxylylene and / or metaxylylene-modified phenolic resins; melamine-modified phenolic resins; terpene-modified phenolic resins; dicyclopentadiene-type phenolic resins and dicyclopentadiene-type naphthol resins synthesized by copolymerization of the above-mentioned phenolic compounds with dicyclopentadiene; cyclopentadiene-modified phenolic resins; polycyclic aromatic ring-modified phenolic resins; biphenyl-type phenolic resins; triphenylmethane-type phenolic resins obtained by condensing or co-condensing the above-mentioned phenolic compounds with aromatic aldehyde compounds such as benzaldehyde and salicylaldehyde under an acidic catalyst; and phenolic resins obtained by copolymerizing two or more of these. These phenolic curing agents may be used alone or in combination of two or more.

[0070] Examples of aralkyl phenolic resins include phenol aralkyl resins and naphthol aralkyl resins synthesized from a phenolic compound and dimethoxy-para-xylene, bis(methoxymethyl)biphenyl, etc. The aralkyl phenolic resin may be further copolymerized with other phenolic resins. Examples of copolymerized aralkyl phenolic resins include copolymerized phenolic resins of triphenylmethane phenolic resin and aralkyl phenolic resin, copolymerized phenolic resins of salicylaldehyde phenolic resin and aralkyl phenolic resin, and copolymerized phenolic resins of novolac phenolic resin and aralkyl phenolic resin.

[0071] The aralkyl phenolic resin is not particularly limited as long as it is a phenolic resin synthesized from at least one compound selected from the group consisting of phenol compounds and naphthol compounds, and dimethoxy-para-xylene, bis(methoxymethyl)biphenyl, or a derivative thereof. For example, phenolic resins represented by the following general formulas (XII) to (XIV) are preferred.

[0072]

[0073] In formulas (XII) to (XIV), R ２３ represents a hydrogen atom or a monovalent organic group having 1 to 18 carbon atoms, and may be the same or different. ２２ , R ２４ , R ２５ and R ２８ R represents a monovalent organic group having 1 to 18 carbon atoms, and may be the same or different. ２６ and R ２７ represents a hydroxyl group or a monovalent organic group having 1 to 18 carbon atoms, and may be the same or different. Each i is independently an integer of 0 to 3, each j is independently an integer of 0 to 2, each k is independently an integer of 0 to 4, and each p is independently an integer of 0 to 4. Each n is an average value and is independently a number of 0 to 10.

[0074] From the viewpoint of the adhesiveness of the curable resin composition of the present disclosure to a lead frame and from the viewpoint of heat resistance, the aralkyl phenolic resin is preferably a phenolic resin represented by general formula (XIII): In the viewpoint of the adhesiveness of the curable resin composition of the present disclosure to a lead frame and from the viewpoint of heat resistance, it is also preferable that i and k in general formula (XIII) are both 0.

[0075] The dicyclopentadiene-type phenolic resin is not particularly limited as long as it is a phenolic resin obtained from a compound having a dicyclopentadiene skeleton as a raw material. For example, a phenolic resin represented by the following general formula (XV) can be mentioned.

[0076]

[0077] In formula (XV), R ２９ represents a monovalent organic group having 1 to 18 carbon atoms, and may be the same or different. Each i independently represents an integer of 0 to 3. n is an average value and represents a number of 0 to 10.

[0078] The triphenylmethane type phenolic resin is not particularly limited as long as it is a phenolic resin obtained from an aromatic aldehyde compound as a raw material. For example, a phenolic resin represented by the following general formula (XVI) is preferred.

[0079]

[0080] In formula (XVI), R ３０ and R ３１ represents a monovalent organic group having 1 to 18 carbon atoms, and may be the same or different. Each i is independently an integer of 0 to 3, and each k is independently an integer of 0 to 4. n is an average value and is a number of 0 to 10.

[0081] The copolymerized phenolic resin of a triphenylmethane phenolic resin and an aralkyl phenolic resin is not particularly limited as long as it is a copolymerized phenolic resin of a phenolic resin obtained from a compound having a benzaldehyde skeleton as a raw material and an aralkyl phenolic resin. For example, a phenolic resin represented by the following general formula (XVII) is preferred.

[0082]

[0083] In formula (XVII), R ３２ ~R ３４ represents a monovalent organic group having 1 to 18 carbon atoms, and may be the same or different. Each i is independently an integer of 0 to 3, each k is independently an integer of 0 to 4, and each q is independently an integer of 0 to 5. Each l and m is an average value and independently a number of 1 to 11.

[0084] The novolac phenolic resin is not particularly limited as long as it is a phenolic resin obtained by condensing or co-condensing at least one phenolic compound selected from the group consisting of phenol compounds and naphthol compounds with an aldehyde compound in the presence of an acid catalyst. For example, a phenolic resin represented by the following general formula (XVIII) is preferred.

[0085]

[0086] In formula (XVIII), R ３５ represents a hydrogen atom or a monovalent organic group having 1 to 18 carbon atoms, and may be the same or different. ３６ represents a monovalent organic group having 1 to 18 carbon atoms, and may be the same or different. Each i independently represents an integer of 0 to 3. n is an average value and represents a number of 0 to 10.

[0087] R in the above general formulae (XII) to (XVIII) ２２ ~R ３６ The expression "may be the same or different" means, for example, that i R ２２ It means that all of the R may be the same or different from each other. ２３ ~R ３６ In addition, the numbers of R may all be the same or different from each other. ２２ ~R ３６ may be the same or different. For example, R ２２ and R ２３ may be the same or different, and R ３０ and R ３１may all be the same or different.

[0088] In the above general formulas (XII) to (XVIII), n is preferably in the range of 0 to 10. If it is 10 or less, the melt viscosity of the resin component will not be too high, and the viscosity of the curable resin composition during melt molding will also be low, making it less likely that filling defects, deformation of bonding wires (gold wires connecting elements to leads), etc. will occur. The average n in one molecule is preferably set in the range of 0 to 4.

[0089] Specific examples of the amine curing agent include aliphatic amine compounds such as diethylenetriamine, triethylenetetramine, n-propylamine, 2-hydroxyethylaminopropylamine, cyclohexylamine, and 4,4'-diamino-dicyclohexylmethane; aromatic amine compounds such as diethyltoluenediamine, 3,3'-diethyl-4,4'-diaminodiphenylmethane, dimethylthiotoluenediamine, and 2-methylaniline; imidazole compounds such as imidazole, 2-methylimidazole, 2-ethylimidazole, and 2-isopropylimidazole; and imidazoline compounds such as imidazoline, 2-methylimidazoline, and 2-ethylimidazoline.

[0090] The functional group equivalent of the curing agent (hydroxyl equivalent in the case of a phenolic curing agent, and active hydrogen equivalent in the case of an amine curing agent) is not particularly limited. From the viewpoint of the balance of various properties such as moldability, heat resistance, and electrical reliability, it is preferably 10 g / eq to 1000 g / eq, and more preferably 30 g / eq to 500 g / eq. In the case of a phenolic curing agent, the hydroxyl equivalent refers to a value calculated based on the hydroxyl value measured in accordance with JIS K 0070:1992. In the case of an amine curing agent, the active hydrogen equivalent refers to a value calculated based on the amine value measured in accordance with JIS K 7237:1995.

[0091] When the curing agent is solid at 25°C, its softening point or melting point is not particularly limited. From the viewpoint of moldability and heat resistance, the softening point or melting point of the curing agent is preferably 40°C to 180°C. Furthermore, from the viewpoint of handleability during production of the curable resin composition, the softening point or melting point of the curing agent is preferably 50°C to 130°C.

[0092] When the curing agent is a phenolic curing agent, the equivalent ratio of the phenolic hydroxyl groups (active hydrogens) of the phenolic curing agent to the epoxy groups of the epoxy resin in the curable resin composition (molar number of phenolic hydroxyl groups (active hydrogens) of the phenolic curing agent / mole number of epoxy groups of the epoxy resin) is not particularly limited and can be, for example, 0.5 to 1.2, 0.5 or more but less than 1.0, 0.55 to 0.9, or 0.6 to 0.8. When the equivalent ratio is 0.5 or more but less than 1.0, the adhesion between the cured product of the curable resin composition and the support member tends to be improved. Although the reason for this is not clear, the value of tan δ near the reflow temperature can be increased, and the internal stress of the cured resin during reflow tends to be alleviated. From the viewpoint of improving the adhesion between the cured product of the curable resin composition and the support member, the equivalent ratio is preferably 0.8 or less, and more preferably 0.75 or less.

[0093] When the curing agent includes a phenol-based curing agent, from the viewpoint of the adhesiveness of the curable resin composition of the present disclosure to a lead frame, the content of the phenol-based curing agent relative to the total mass of the curing agent is preferably 50% by mass to 100% by mass, more preferably 60% by mass to 100% by mass, and even more preferably 70% by mass to 100% by mass.

[0094] When the phenolic curing agent contains an aralkyl phenolic resin, from the viewpoint of the adhesiveness of the curable resin composition of the present disclosure to a lead frame, the content of the aralkyl phenolic resin relative to the total mass of the phenolic curing agent may be greater than 0 mass% and not more than 100 mass%, or may be 50 mass% to 70 mass%, or 80 mass% to 100 mass%. The phenolic curing agent may not contain an aralkyl phenolic resin.

[0095] When the phenol-based curing agent contains a triphenylmethane-type phenolic resin, from the viewpoint of the adhesiveness of the curable resin composition of the present disclosure to a lead frame, the content of the triphenylmethane-type phenolic resin relative to the total mass of the phenol-based curing agent may be greater than 0 mass% and not more than 90 mass%, or may be 20 mass% to 50 mass%, or 70 mass% to 90 mass%.

[0096] (Inorganic filler) The curable resin composition of the present disclosure may contain an inorganic filler. When the curable resin composition contains an inorganic filler, the moisture absorption of the curable resin composition tends to be reduced and the strength in the cured state tends to be improved. When the curable resin composition is used as an encapsulant for a semiconductor package, it is preferable that the curable resin composition contains an inorganic filler.

[0097] The inorganic material constituting the inorganic filler is not particularly limited. Specific examples of inorganic materials include spherical silica, crystalline silica, glass, alumina, calcium carbonate, zirconium silicate, calcium silicate, silicon nitride, aluminum nitride, boron nitride, aluminum nitride, boehmite, beryllia, magnesium oxide, zirconia, zircon, fosterite, steatite, spinel, mullite, titania, talc, clay, mica, and titanates. Inorganic fillers composed of inorganic materials having flame retardant properties may also be used. Examples of inorganic materials having flame retardant properties include aluminum hydroxide, magnesium hydroxide, composite metal hydroxides such as composite hydroxides of magnesium and zinc, and zinc borate. One type of inorganic filler may be used alone, or two or more types may be used in combination.

[0098] The shape of the inorganic filler is not particularly limited, and examples thereof include powder, spheres, fibers, etc. From the viewpoints of flowability and mold wear during molding of the curable resin composition, a spherical shape is preferred.

[0099] The average particle diameter of the inorganic filler is not particularly limited. From the viewpoint of the balance between the viscosity, filling property, etc. of the curable resin composition, the volume average particle diameter of the inorganic filler is preferably 0.1 μm to 50 μm, more preferably 0.3 μm to 30 μm, and even more preferably 0.5 μm to 25 μm. The volume average particle diameter of the inorganic filler can be measured as the volume average particle diameter (D50) using a laser diffraction scattering particle size distribution measuring device.

[0100] The particle size of the inorganic filler may be top-cut, may be top-cut at 100 μm or less, or may be top-cut at 75 μm or less. The top-cut particle size can be determined from the particle size distribution when the volume average particle size (D50) is measured.

[0101] When the curable resin composition contains an inorganic filler, its content is not particularly limited. The content of the inorganic filler relative to the entire curable resin composition is preferably 30% by mass to 90% by mass, more preferably 35% by mass to 80% by mass, and even more preferably 40% by mass to 70% by mass. When the content of the inorganic filler is 30% by mass or more of the entire curable resin composition, the properties of the cured product, such as the coefficient of thermal expansion, thermal conductivity, and modulus of elasticity, tend to be further improved. When the content of the inorganic filler is 90% by mass or less of the entire curable resin composition, an increase in the viscosity of the curable resin composition is suppressed, and the flowability is further improved, tending to result in better moldability.

[0102] The content of the inorganic filler relative to the entire curable resin composition is preferably 68 to 86% by volume, more preferably 70 to 84% by volume, and even more preferably 72 to 82% by volume. When the content of the inorganic filler is 68% by volume or more of the entire curable resin composition, the properties of the cured product, such as the coefficient of thermal expansion, thermal conductivity, and modulus of elasticity, tend to be further improved. When the content of the inorganic filler is 86% by volume or less of the entire curable resin composition, an increase in the viscosity of the curable resin composition is suppressed, and the fluidity is further improved, tending to result in better moldability.

[0103] (Curing Accelerator) The curable resin composition of the present disclosure may contain a curing accelerator. The type of curing accelerator is not particularly limited and can be selected depending on the type of epoxy resin, the desired properties of the curable resin composition, etc. One type of curing accelerator may be used alone, or two or more types may be used in combination. Specific examples of curing accelerators are described below, but are not limited thereto. Examples of the curing accelerator include diazabicycloalkenes such as 1,5-diazabicyclo[4.3.0]nonene-5 (DBN) and 1,8-diazabicyclo[5.4.0]undecene-7 (DBU), cyclic amidine compounds such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, and 2-heptadecylimidazole; derivatives of the cyclic amidine compounds; phenol novolac salts of the cyclic amidine compounds or their derivatives; quinone compounds such as maleic anhydride, 1,4-benzoquinone, 2,5-toluquinone, 1,4-naphthoquinone, 2,3-dimethylbenzoquinone, 2,6-dimethylbenzoquinone, 2,3-dimethoxy-5-methyl-1,4-benzoquinone, 2,3-dimethoxy-1,4-benzoquinone, and phenyl-1,4-benzoquinone; compounds having intramolecular polarization obtained by adding a compound having a π bond, such as 2-isophenylmethane; cyclic amidinium compounds such as the tetraphenylborate salt of DBU, the tetraphenylborate salt of DBN, the tetraphenylborate salt of 2-ethyl-4-methylimidazole, and the tetraphenylborate salt of N-methylmorpholine; tertiary amine compounds such as pyridine, triethylamine, triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris(dimethylaminomethyl)phenol; derivatives of the above tertiary amine compounds; ammonium salt compounds such as tetra-n-butylammonium acetate, tetra-n-butylammonium phosphate, tetraethylammonium acetate, tetra-n-hexylammonium benzoate, and tetrapropylammonium hydroxide;organic phosphines such as primary phosphines such as ethylphosphine and phenylphosphine; secondary phosphines such as dimethylphosphine and diphenylphosphine; and tertiary phosphines such as triphenylphosphine, diphenyl(p-tolyl)phosphine, tris(alkylphenyl)phosphine, tris(alkoxyphenyl)phosphine, tris(alkylalkoxyphenyl)phosphine, tris(dialkylphenyl)phosphine, tris(trialkylphenyl)phosphine, tris(tetraalkylphenyl)phosphine, tris(dialkoxyphenyl)phosphine, tris(trialkoxyphenyl)phosphine, tris(tetraalkoxyphenyl)phosphine, trialkylphosphine, dialkylarylphosphine, alkyldiarylphosphine, trinaphthylphosphine, and tris(benzyl)phosphine; phosphine compounds such as complexes of the organic phosphines with organic borons; and complexes of the organic phosphines or the phosphine compounds with maleic anhydride, 1,4-benzoquinone, 2,5-toluquinone, 1,4-naphthoquinone, 2,3-dimethylbenzoquinone, compounds having intramolecular polarization obtained by adding a compound having a π bond, such as quinone compounds, such as 2,6-dimethylbenzoquinone, 2,3-dimethoxy-5-methyl-1,4-benzoquinone, 2,3-dimethoxy-1,4-benzoquinone, phenyl-1,4-benzoquinone, and anthraquinone, or diazophenylmethane; a compound having intramolecular polarization, which is obtained by reacting a halogenated phenol compound such as bromo-1-naphthol, 3-iodophenol, 2-iodophenol, 4-bromo-2-methylphenol, 4-bromo-3-methylphenol, 4-bromo-2,6-dimethylphenol, 4-bromo-3,5-dimethylphenol, 4-bromo-2,6-di-t-butylphenol, 4-chloro-1-naphthol, 1-bromo-2-naphthol, 6-bromo-2-naphthol, or 4-bromo-4'-hydroxybiphenyl, followed by a dehydrohalogenation step;Examples of suitable curing accelerators include tetra-substituted phosphonium compounds such as tetraphenylphosphonium, tetraphenylborate salts of tetra-substituted phosphonium such as tetraphenylphosphonium tetra-p-tolylborate, and salts of tetra-substituted phosphonium with phenolic compounds; phosphobetaine compounds; and adducts of phosphonium compounds with silane compounds. Suitable curing accelerators include triphenylphosphine and adducts of triphenylphosphine with quinone compounds.

[0104] When the curable resin composition contains a curing accelerator, the content of the curing accelerator is preferably 0.1% by mass to 8% by mass, more preferably 0.3% by mass to 7% by mass, and even more preferably 0.5% by mass to 6% by mass, relative to 100 parts by mass of the total amount of the epoxy resin and the curing agent. By setting the content of the curing accelerator within the above range, the curing rate of the curable resin composition of the present disclosure becomes an appropriate value, making it easy to produce molded articles.

[0105] (Various Additives) In addition to the above-described components, the curable resin composition of the present disclosure may contain various additives such as a coupling agent, a stress relaxation agent, a release agent, a colorant, a flame retardant, an ion exchanger, and an ultraviolet absorber. The curable resin composition of the present disclosure may also contain a siloxane compound having a structural unit having an epoxy group and an alkoxy group and having a degree of polymerization of 2. The curable resin composition may contain various additives known in the technical field as needed, in addition to the additives exemplified below.

[0106] (Coupling Agent) The curable resin composition of the present disclosure may contain a coupling agent. The type of coupling agent is not particularly limited, and known coupling agents can be used. Examples of the coupling agent include silane coupling agents and titanium coupling agents. One type of coupling agent may be used alone, or two or more types may be used in combination.

[0107] The silane coupling agent is not particularly limited, and examples thereof include methyltrimethoxysilane, bis(3-(triethoxysilyl)propyl)tetrasulfide, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-(2-aminoethyl)aminopropyltrimethoxysilane, 3-(2-aminoethyl)aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-ureidopropyltriethoxysilane, octenyltrimethoxysilane, glycidoxyoctyltrimethoxysilane, and methacryloxyoctyltrimethoxysilane.

[0108] Examples of titanium coupling agents include isopropyl triisostearoyl titanate, isopropyl tris(dioctyl pyrophosphate) titanate, isopropyl tri(N-aminoethyl-aminoethyl) titanate, tetraoctyl bis(ditridecyl phosphite) titanate, tetra(2,2-diallyloxymethyl-1-butyl)bis(ditridecyl phosphite) titanate, bis(dioctyl pyrophosphate)oxyacetate titanate, bis(dioctyl pyrophosphate)ethylene titanate, isopropyl trioctanoyl titanate, isopropyl dimethacryl isostearoyl titanate, isopropyl tridodecylbenzenesulfonyl titanate, isopropyl isostearoyl diacryl titanate, isopropyl tri(dioctyl phosphate) titanate, isopropyl tricumylphenyl titanate, and tetraisopropyl bis(dioctyl phosphite) titanate.

[0109] When the curable resin composition contains a coupling agent, the content of the coupling agent is preferably 0.001 to 10 parts by mass, more preferably 0.01 to 8 parts by mass, and even more preferably 0.05 to 5 parts by mass, relative to 100 parts by mass of the inorganic filler contained in the curable resin composition, from the viewpoint of the adhesiveness at the interface between the epoxy resin and the inorganic filler.

[0110] (Stress Relaxant) The curable resin composition of the present disclosure may contain a stress relaxation agent such as silicone oil or silicone rubber particles. By including a stress relaxation agent in the curable resin composition, package warpage and package cracking can be further reduced. Examples of the stress relaxation agent include commonly used known stress relaxation agents (flexibilizers). Specific examples of the stress relaxation agent include thermoplastic elastomers such as silicone-based, styrene-based, olefin-based, urethane-based, polyester-based, polyether-based, polyamide-based, and polybutadiene-based elastomers; rubber particles such as natural rubber (NR), acrylonitrile-butadiene copolymer (NBR), acrylic rubber, urethane rubber, and silicone powder; and rubber particles having a core-shell structure such as methyl methacrylate-styrene-butadiene copolymer (MBS), methyl methacrylate-silicone copolymer, and methyl methacrylate-butyl acrylate copolymer. The stress relaxation agent may be used alone or in combination of two or more types. Among these, silicone-based stress relaxation agents are preferred. Examples of silicone-based stress relaxation agents include those having an epoxy group, those having an amino group, and those modified with polyether.

[0111] When the curable resin composition contains a stress relaxation agent, the content thereof is preferably 10 parts by mass to 60 parts by mass, and more preferably 20 parts by mass to 50 parts by mass, relative to 100 parts by mass of the epoxy resin contained in the curable resin composition.

[0112] (Mold Release Agent) When a mold is used during molding, the curable resin composition of the present disclosure may contain a mold release agent from the viewpoint of mold releasability. There are no particular limitations on the mold release agent, and conventionally known ones can be used. Examples of the mold release agent include carnauba wax, higher fatty acids such as montanic acid and stearic acid, higher fatty acid metal salts, ester waxes such as montanic acid esters, and polyolefin waxes such as oxidized polyethylene and non-oxidized polyethylene. One type of mold release agent may be used alone, or two or more types may be used in combination.

[0113] When the curable resin composition of the present disclosure contains a release agent, the content of the release agent is preferably 0.01 to 15 parts by mass, and more preferably 0.1 to 10 parts by mass, per 100 parts by mass of the epoxy resin contained in the curable resin composition. When the amount of the release agent is 0.01 parts by mass or more per 100 parts by mass of the resin component, sufficient release properties tend to be obtained. When the amount is 15 parts by mass or less, better release properties tend to be obtained.

[0114] (Colorant) The curable resin composition of the present disclosure may contain a colorant. Examples of the colorant include known colorants such as carbon black, organic dyes, organic pigments, titanium oxide, red lead, and red iron oxide. The content of the colorant can be appropriately selected depending on the purpose, etc. One type of colorant may be used alone, or two or more types may be used in combination.

[0115] When the curable resin composition contains a colorant, the content thereof is preferably 0.01% by mass to 5% by mass, and more preferably 0.05% by mass to 4% by mass.

[0116] (Flame Retardant) The curable resin composition of the present disclosure may contain a flame retardant. The flame retardant is not particularly limited, and conventionally known flame retardants can be used. Examples of the flame retardant include organic or inorganic compounds containing a halogen atom, an antimony atom, a nitrogen atom, or a phosphorus atom, and metal hydroxides. One type of flame retardant may be used alone, or two or more types may be used in combination.

[0117] When the curable resin composition of the present disclosure contains a flame retardant, the content thereof is not particularly limited as long as it is an amount sufficient to obtain the desired flame retardant effect. The content of the flame retardant is preferably 1 part by mass to 300 parts by mass, more preferably 2 parts by mass to 150 parts by mass, per 100 parts by mass of the epoxy resin contained in the curable resin composition.

[0118] (Ion Exchanger) The curable resin composition of the present disclosure may contain an ion exchanger. When the curable resin composition is used as an encapsulant for a semiconductor package, it is preferable to contain an inorganic ion exchanger from the viewpoint of improving the moisture resistance and high-temperature storage characteristics of an electronic component device including an encapsulated element. The ion exchanger is not particularly limited, and conventionally known ion exchangers can be used. Specific examples include hydrotalcite compounds and hydrous oxides of at least one element selected from the group consisting of magnesium, aluminum, titanium, zirconium, and bismuth. The ion exchanger may be used alone or in combination of two or more types. Specific examples of the ion exchanger include hydrotalcites represented by the following general formula (A):

[0119] Mg （１－Ｘ） Al Ｘ (OH) ２ (CO ３ ) Ｘ／２ ・mH ２ O...(A) (0<X≦0.5, m is a positive number)

[0120] When the curable resin composition of the present disclosure contains an ion exchanger, the content thereof is not particularly limited as long as it is an amount sufficient to capture ions such as halogen ions, etc. The content of the ion exchanger is preferably 0.1 to 30 parts by mass, and more preferably 1 to 6 parts by mass, per 100 parts by mass of the epoxy resin contained in the curable resin composition.

[0121] (Physical Properties of Curable Resin Composition) From the viewpoint of fluidity, the curable resin composition of the present disclosure preferably has a spiral flow of 90 cm or more, more preferably 120 cm or more, and even more preferably 140 cm or more, as determined by the following method. The upper limit of the spiral flow is not particularly limited, and may be, for example, 170 cm or less.

[0122] The spiral flow is measured by using a spiral flow measurement mold conforming to EMMI-1-66 to determine the flow distance when the curable resin composition is molded under the conditions of a mold temperature of 175°C, a molding pressure of 6.9 MPa, and a curing time of 90 seconds.

[0123] The gel time of the curable resin composition at 175°C is preferably 15 seconds or more, more preferably 18 seconds or more, and even more preferably 21 seconds or more, from the viewpoints of fluidity and curability.

[0124] The gel time is measured from the time when 0.5 g of the thermosetting resin composition is placed on a hot plate preheated to 175°C until the resin loses its viscosity. It is preferable to heat the resin while periodically stirring it with a spatula or similar. "Loss of viscosity" refers to the phenomenon in which the resin breaks or is destroyed when kneaded with a spatula or similar.

[0125] The linear expansion coefficient (α1) of the cured product of the curable resin composition at 10°C to 30°C may be 8.0 ppm / °C or more, or may be 9.0 ppm / °C to 12.0 ppm / °C.

[0126] From the viewpoint of suppressing warpage of the package of the cured product of the curable resin composition of the present disclosure, the linear expansion coefficient of the cured product of the curable resin composition at 180°C to 200°C is preferably 32.0 ppm / °C or higher, more preferably 33.0 ppm / °C or higher, and even more preferably 34.0 ppm / °C or higher. Previously, it was believed that the smaller the linear expansion coefficient, the more likely peeling from the lead frame was suppressed. However, it has been found that, in the curable resin composition of the present disclosure, a linear expansion coefficient of 32.0 ppm / °C or higher at 180°C to 200°C of the cured product is more effective in suppressing peeling from the lead frame. The reason for this is unclear, but it is presumed to be due to the thermal stress reduction effect caused by the suppression of warpage due to the difference in linear expansion coefficient between components. In particular, the curable resin composition of the present disclosure can lower the glass transition temperature (Tg), which can widen the allowable range of the linear expansion coefficient. The upper limit of the linear expansion coefficient is preferably 60 ppm / °C or less, more preferably 55 ppm / °C or less, and even more preferably 50 ppm / °C or less, from the viewpoint of suppressing the generation of thermal stress with the packaging members.

[0127] In the present disclosure, the linear expansion coefficients α1 and α2 are the slopes of the tangent line between 10°C and 30°C and the slope of the tangent line between 180°C and 200°C when the strain of a cured product is plotted against temperature by thermal mechanical analysis (TMA) based on JIS K 7197:2012. Measurements are performed using a test load of 98 mN and a heating rate of 5°C / min. The linear expansion coefficient can be measured using a thermomechanical analyzer (e.g., TMA / SS6100 manufactured by Seiko Instruments Inc.). The cured product is produced by molding the curable resin composition using a transfer molding machine under conditions of a mold temperature of 175°C, a molding pressure of 6.9 MPa, and a curing time of 90 seconds, followed by post-curing at 175°C for 5 hours. The cured product has a rectangular shape with short sides of 5.1 mm, long sides of 20 mm, and a thickness of 2 mm.

[0128] From the viewpoint of heat resistance and the like, the glass transition temperature (Tg) of the cured product of the curable resin composition is preferably higher than 110° C., more preferably 112° C. or higher, and even more preferably 115° C. or higher. There is no particular upper limit to the Tg, and it may be 200° C. or lower, or 180° C. or lower.

[0129] In the present disclosure, the glass transition temperature of the cured product is the temperature at the intersection of the tangent line between 10°C and 30°C and the tangent line between 200°C and 220°C, obtained by measuring the linear expansion coefficient.

[0130] From the viewpoint of the adhesiveness of the cured product of the curable resin composition of the present disclosure to a lead frame, the elastic modulus of the cured product of the curable resin composition at 260°C is preferably 1000 MPa or less, more preferably 900 MPa or less, and even more preferably 800 MPa or less, although this depends on the amount of filler.

[0131] The elastic modulus of the cured product of the curable resin composition is measured using a viscoelasticity measuring device (for example, RSAIII manufactured by TA Instruments) at a span distance of 40 mm and a frequency of 1 Hz by a three-point bending method, raising the temperature from 20°C to 300°C at a rate of 5°C / min, and determining the elastic modulus at 260°C. The cured product is produced by the method described for the linear expansion coefficient. The cured product used has a rectangular shape with short sides of 5.1 mm, long sides of 20 mm, and a thickness of 2 mm.

[0132] From the viewpoint of adhesiveness to a lead frame of a cured product of the curable resin composition of the present disclosure, the adhesive strength (also referred to as adhesive strength 1) of the cured product to AgCu at room temperature (e.g., 25°C) is preferably 7.0 MPa or more, more preferably 7.5 MPa or more. Furthermore, the upper limit of adhesive strength 1 is not particularly limited and may be, for example, 10 MPa or less.

[0133] From the viewpoint of the adhesiveness of the cured product of the curable resin composition of the present disclosure to a lead frame, the adhesive strength of the cured product to AgCu after heating and humidifying at 85°C and 85% RH for 168 hours (also referred to as adhesive strength 2) at 260°C is 0.40 MPa or more, preferably 0.42 MPa or more, and more preferably 0.45 MPa or more. The upper limit of adhesive strength 2 is not particularly limited and may be, for example, 1.00 MPa or less.

[0134] To measure Adhesion Strength 1, a sample is prepared by first transferring a curable resin composition onto an Ag-plated Cu substrate using a transfer mold, curing the composition at 175°C for 120 seconds, and then post-curing the composition at 175°C for 5 hours. The cured sample has a short side of 3.0 mm, a long side of 3.5 mm, and a thickness of 2.9 mm. The sample is subjected to a shear strength test using a bond tester (e.g., Nordson 4000 Optima) at room temperature (e.g., 25°C) in which a tool of the device is applied to the cured product.

[0135] For measuring adhesive strength 2, a sample is prepared in the same manner as for measuring adhesive strength 1. This sample is heated and humidified at 85°C and 85% RH for 168 hours, and then a shear strength test is performed using a bond tester (for example, Nordson Corporation, product name 4000 Optima) in which a tool of the device is brought into contact with the cured product at 260°C to measure the adhesive strength.

[0136] The curing shrinkage of a molded product of the curable resin composition of the present disclosure molded under conditions of a mold temperature of 175°C, a molding pressure of 6.9 MPa, and a curing time of 90 seconds (shrinkage 1 in the examples) may be 0.37% or more, 0.38% or more, or 0.40% or more. The upper limit of the cure shrinkage of the molded product is not particularly limited, and may be, for example, 0.50% or less.

[0137] (Method for producing curable resin composition) The method for producing the curable resin composition is not particularly limited. A common method includes thoroughly mixing predetermined amounts of components using a mixer or the like, melt-kneading the mixture using a mixing roll, extruder, or the like, cooling, and pulverizing the mixture. More specifically, for example, a method includes uniformly stirring and mixing predetermined amounts of the components described above, kneading the mixture using a kneader, roll, extruder, or the like that has been preheated to 70°C to 140°C, cooling, and pulverizing the mixture.

[0138] The curable resin composition is preferably a solid at 25° C. When the curable resin composition is a solid at 25° C., the shape of the curable resin composition is not particularly limited, and examples thereof include powder, granules, and tablets. When the curable resin composition is in tablet form, it is preferable that the dimensions and mass of the tablet-shaped curable resin composition be such that they are suitable for the molding conditions of the package, from the viewpoint of handleability.

[0139] (Applications of Curable Resin Composition) The application of the curable resin composition of the present disclosure is not particularly limited, and it can be used in various packaging techniques, for example, as a sealing material for electronic component devices. In addition, the curable resin composition of the present disclosure can be used in various applications in which it is desirable for the resin composition to have good fluidity and curability, such as resin molded articles for various modules, resin molded articles for motors, resin molded articles for in-vehicle use, and sealing materials for electronic circuit protection materials.

[0140] <Electronic Component Device> The electronic component device of the present disclosure includes an element and a cured product of the curable resin composition that encapsulates the element.

[0141] The electronic component device may include a support member on which elements are mounted. Examples of the support member include a lead frame, a pre-wired tape carrier, a wiring board, glass, a silicon wafer, and an organic substrate. Among the support members, a lead frame is preferred from the viewpoint of adhesion to the cured product of the curable resin composition.

[0142] The surface of the lead frame may or may not be roughened, but from the viewpoint of production costs, a lead frame is preferred, and from the viewpoint of adhesiveness, a roughened lead frame is preferred. The surface roughening method is not particularly limited, and examples thereof include alkali treatment, silane coupling treatment, sand matte treatment, plasma treatment, and corona discharge treatment.

[0143] The lead frame preferably contains Ag, and may further contain Cu or the like.

[0144] Examples of elements included in an electronic component device include active elements such as silicon chips, transistors, diodes, and thyristors, and passive elements such as capacitors, resistors, and coils.

[0145] Specific configurations of the electronic component device include, but are not limited to, the following: (1) General resin-sealed ICs such as DIP (Dual Inline Package), PLCC (Plastic Leaded Chip Carrier), QFP (Quad Flat Package), SOP (Small Outline Package), SOJ (Small Outline J-lead Package), TSOP (Thin Small Outline Package), and TQFP (Thin Quad Flat Package), which have a structure in which an element is fixed on a lead frame, and terminal portions of the element such as bonding pads and lead portions are connected using wire bonding, bumps, or the like, and then sealed using a curable resin composition; (2) TCP (Tape Carrier Package) having a structure in which elements connected to a tape carrier using bumps are sealed with a curable resin composition; (3) COB (Chip On Board) modules, hybrid ICs, multi-chip modules, etc. having a structure in which elements connected to wiring formed on a support member using wire bonding, flip chip bonding, solder, etc. are sealed with a curable resin composition; (4) BGA (Ball Grid Array), CSP (Chip Size Package), MCP (Multi Chip Package), SiP (System in a) having a structure in which elements are mounted on the surface of a support member having terminals for wiring board connection formed on the back side, the elements are connected to the wiring formed on the support member using bumps or wire bonding, and then the elements are sealed with a curable resin composition. Package) etc.

[0146] The method for encapsulating the element using the curable resin composition is not particularly limited, and known methods can be applied. For example, low-pressure transfer molding is a common encapsulation method, but injection molding, compression molding, casting, etc. may also be used.

[0147] The present disclosure will be specifically described below using examples, but the present disclosure is not limited to these examples. Furthermore, the numerical values ​​in the tables mean "parts by mass" unless otherwise specified.

[0148] [Examples 1 to 3 and Comparative Examples 1 and 2] The materials shown in Table 1 were premixed (dry blended), then kneaded for about 15 minutes with a biaxial roll (roll surface temperature: about 80°C), cooled, and pulverized to produce a powdered curable resin composition. The equivalent ratio of the phenolic hydroxyl groups (active hydrogen) of the phenolic curing agent to the epoxy groups of the epoxy resin was 0.7.

[0149] The details of the materials in Table 1 are as follows:

[0150] Epoxy resin 1: triphenylmethane type epoxy resin represented by formula (2), epoxy equivalent 214 g / eq. Epoxy resin 2: sulfur atom-containing epoxy resin, epoxy equivalent 238 g / eq to 254 g / eq, melting point 116°C to 126°C. Epoxy resin 3: biphenyl type epoxy resin, epoxy equivalent 241 g / eq. Epoxy resin 4: methoxynaphthalene-cresol formaldehyde co-condensation type epoxy resin, epoxy equivalent 250 g / eq. Epoxy resin 5: biphenyl type epoxy resin, epoxy equivalent 192 g / eq. Epoxy resin 6: biphenyl type epoxy resin, epoxy equivalent 192 g / eq. Epoxy resin 7: biphenyl type epoxy resin, epoxy equivalent 192 g / eq.

[0151] Curing agent 1: aralkyl type phenol resin, hydroxyl group equivalent 175 g / eq. Curing agent 2: triphenylmethane type phenol resin, hydroxyl group equivalent 104 g / eq. Curing agent 3: alkyl-modified type phenol resin, hydroxyl group equivalent 224 g / eq. Curing agent 4: biphenylaralkyl type phenol resin, hydroxyl group equivalent 204 g / eq. Curing agent 5: aminotriazine-modified type phenol resin, amine equivalent 120 g / eq. Ultraviolet absorber 1: benzotriazole-based ultraviolet absorber. Ultraviolet absorber 2: triazine-based ultraviolet absorber. Curing accelerator 1: 1,4-benzoquinone adduct of triphenylphosphine. Curing accelerator 2: triphenylphosphine. Coupling agent 1: N-phenyl-3-aminopropyltrimethoxysilane. Coupling agent 2: 3-glycidoxypropyltrimethoxysilane. Coupling agent 3: bis(3-(triethoxysilyl)propyl)tetrasulfide. Coupling agent 4: 3-mercaptopropyltrimethoxysilane Coupling agent 5: methyltrimethoxysilane Mold release agent: ester wax such as montanic acid ester Colorant: carbon black Ion exchanger 1: uncalcined hydrotalcite compound (Mg / Al=3.0) Ion exchanger 2: uncalcined hydrotalcite compound (Mg / Al=2.25) Ion exchanger 3: uncalcined hydrotalcite compound (Mg / Al=3.0) Stress relaxation agent 1: silicone-based stress relaxation agent having epoxy groups Stress relaxation agent 2: triphenylphosphine oxide Stress relaxation agent 3: coumarone resin, softening point 100°C, Nippon Paint Chemical Co., Ltd. Stress relaxation agent 4: indene polymer Inorganic filler 1: spherical silica particles with a volume average particle diameter of 26.9 μm Inorganic filler 2: spherical silica particles with a volume average particle diameter of 0.5 μm Inorganic filler 3: spherical silica particles with a volume average particle size of 20 μm

[0152] <<Evaluation of Curable Resin Compositions>> The properties of the curable resin compositions prepared in the Examples and Comparative Examples were measured and evaluated by the following methods. The evaluation results are shown in Table 2.

[0153] <Measurement of Spiral Flow> The spiral flow of the curable resin composition was measured by the method described above.

[0154] <Measurement of Gel Time> The gel time of the curable resin composition was measured by the method described above.

[0155] <Measurement of Linear Expansion Coefficient> Using the method described above, the thermal expansion coefficient (α1) from 10° C. to 30° C. and the thermal expansion coefficient (α2) from 180° C. to 200° C. of the cured product of the curable resin composition were measured. The thermomechanical analyzer used was TMA / SS6100 manufactured by Seiko Instruments Inc.

[0156] <Glass Transition Temperature (Tg) of Cured Product> The temperature at the intersection of the tangent line at 10°C to 30°C and the tangent line at 200°C to 220°C, obtained by measuring the linear expansion coefficient, was taken as the glass transition temperature of the cured product.

[0157] <Measurement of Shrinkage Factor 1> Using a mold whose dimensions had been measured, a disc-shaped molded product (test piece) of the curable resin composition obtained in the above Examples and Comparative Examples was molded by transfer molding under conditions of a mold temperature of 175°C, a molding pressure of 6.9 MPa, and a curing time of 90 seconds, and then the test piece was allowed to cool to 25°C. After cooling, the average value of the diameters at two points on the front and back of the test piece was taken as Rm (mm), and the average value of the inner diameters at two points on the mold corresponding to the front of the test piece and the inner diameters at two points on the mold corresponding to the back of the test piece was taken as Rd (mm), and these were substituted into the following formula to determine the cure shrinkage factor of the curable resin composition (shrinkage factor 1). Shrinkage Factor 1 (%) = [(Rd - Rm) / Rd] × 100

[0158] <Measurement of Shrinkage Factor 2> Using a mold whose dimensions had been measured, a disc-shaped cured product (test piece) of the curable resin composition obtained in the above Examples and Comparative Examples was molded by transfer molding under conditions of a mold temperature of 175°C, a molding pressure of 6.9 MPa, and a curing time of 90 seconds, and then the test piece was allowed to cool to 25°C. After cooling to 25°C, the test piece was heated for 5 hours in an oven heated to 175°C and then allowed to cool to 25°C. After cooling, the average value of the diameters at two points on the front and back of the test piece was taken as Rm (mm), and the average value of the inner diameters at two points on the mold corresponding to the front of the test piece and the inner diameters at two points on the mold corresponding to the back of the test piece was taken as Rd (mm), and the cure shrinkage factor of the curable resin composition (shrinkage factor 2) was determined by substituting these values ​​into the following formula: Shrinkage Factor 2 (%) = [(Rd - Rm) / Rd] × 100

[0159] <Measurement of Adhesion Strength 1 to AgCu> The adhesive strength 1 to AgCu of the cured product of the curable resin composition was measured using the method described above. The measuring device used was a 4000 Optima product manufactured by Nordson Corporation.

[0160] <Measurement of Adhesion Strength 2 to AgCu> The adhesive strength 2 to AgCu of the cured product of the curable resin composition was measured by the method described above. The measuring device used was a 4000 Optima product manufactured by Nordson Corporation.

[0161] <Evaluation of Peelability During High-Temperature Moisture Absorption> An 80-pin flat package (lead frame material: AgCu) with external dimensions of 20 mm length, 14 mm width, and 2 mm thickness was fabricated, incorporating a silicon chip (8 mm length, 10 mm width, 0.4 mm thickness) encapsulated using a cured product of the curable resin composition formed under the above conditions. The package was heated at 85°C and 85% RH for 168 hours (MSL1). Thereafter, a reflow treatment was performed at 260°C for 10 seconds, and the presence or absence of peeling inside the package was observed using an ultrasonic flaw detector (HYE-FOCUS, manufactured by Hitachi Construction Machinery Co., Ltd.). Peelability was evaluated based on the number of packages that exhibited peeling (Fail) out of the total number of test packages (16).

[0162]

[0163]

[0164] As shown in Table 2, it can be seen that under the heating and humidifying conditions of 85° C. and 85% RH for 168 hours, peeling was significantly suppressed in the Examples compared to the Comparative Examples.

[0165] The disclosure of Japanese Patent Application No. 2023-219887, filed on December 26, 2023, is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards mentioned herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard was specifically and individually indicated to be incorporated by reference.

Claims

1. A curable resin composition containing an epoxy resin, wherein the adhesive strength at 260°C after heating and humidifying the cured product at 85°C and 85% RH for 168 hours against AgCu is 0.40 MPa or more.

2. The curable resin composition according to claim 1, further containing a curing agent, wherein the equivalent ratio of the curing agent / curing agent to the epoxy resin is 0.8 or less.

3. The curable resin composition according to claim 1, wherein the glass transition temperature of the cured product is higher than 110°C.

4. The curable resin composition according to claim 1, wherein the thermal expansion coefficient α2 measured at 180°C to 200°C is 32.0 ppm / °C or more.

5. The curable resin composition according to claim 1, wherein the epoxy resin contains at least one selected from the group consisting of a triphenylmethane type epoxy resin containing a t-Bu group and a biphenyl type epoxy resin.

6. The curable resin composition according to claim 1, further containing an inorganic filler.

7. An electronic component device including an element and a cured product of the curable resin composition according to any one of claims 1 to 6 for encapsulating the element.

8. The electronic component device according to claim 7, comprising a lead frame on which the element is mounted on one surface.

9. The electronic component device according to claim 8, wherein the lead frame contains Ag.

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