Encapsulating resin composition and electronic device

Abstract

To provide a sealing resin composition that has high flowability and excellent moldability when molded and shows high thermal conductivity and excellent heat dissipation when cured, and an electronic apparatus that is produced therewith and has excellent reliability.SOLUTION: A sealing resin composition contains epoxy resin, phenolic resin curing agent, curing accelerator, and inorganic filler including first inorganic filler and second inorganic filler. The first inorganic filler comprises alumina particles. The second inorganic filler comprises complex particles containing aluminum oxide and aluminum borate.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an encapsulating resin composition and an electronic device manufactured using the encapsulating resin composition as an encapsulant. [Background technology]

[0002] In recent years, with the advancement of high performance and high speed in heat-generating electronic components such as ICs, the amount of heat generated by electronic devices equipped with these components has increased, and high heat dissipation properties are also required in semiconductor encapsulation materials. To improve the thermal conductivity of resin compositions, inorganic fillers such as aluminum nitride, boron nitride, alumina, and crystalline silica are commonly used. Among these, alumina, which offers an excellent balance of thermal conductivity, chemical stability, and cost, is the most commonly used heat dissipation filler.

[0003] However, increasing the amount of alumina powder added to a resin increases the viscosity of the resin composition, worsening moldability and resulting in reduced productivity. Furthermore, because alumina has a high Mohs hardness, contact with the metal parts of a mold at high viscosity can easily cause wear on the equipment. To solve these problems, it is necessary to reduce the viscosity of a resin composition filled with alumina powder. Proposed methods for adjusting the viscosity of a resin composition include using alumina that is nearly spherical rather than irregularly shaped, such as crushed or without cutting edges, and incorporating alumina particles with several different average particle sizes into a resin (e.g., Reference 1).

[0004] Cited Document 1 discloses a highly thermally conductive inorganic powder obtained by mixing a spherical inorganic powder having a particle size range of 3 to 40 μm and a circularity of 0.80 or more with a spherical or non-spherical inorganic powder having a particle size range of 0.1 to 1.5 μm and a circularity of 0.30 or more but less than 0.80. The examples also disclose an alumina mixed powder containing a non-spherical aluminum oxide powder having an average particle size of 0.5 μm or 0.3 μm and a spherical aluminum oxide powder having an average particle size of 15 μm or 8 μm. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-137627 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the technology described in Patent Document 1, when the alumina powder is highly loaded, the resin composition experiences a significant increase in viscosity, leaving room for improvement in the moldability of the resin composition and the reliability of the resulting electronic device.

[0007] The present invention has been made in consideration of the above-mentioned problems, and aims to provide an encapsulating resin composition that has high fluidity and excellent moldability during molding, and has high thermal conductivity and excellent heat dissipation properties when cured, and an electronic device that is manufactured using the same and has excellent reliability. [Means for solving the problem]

[0008] The present inventors have found that by using a combination of alumina particles and aluminum oxide / aluminum borate composite particles as an inorganic filler, an encapsulating resin composition having high fluidity during molding and high thermal conductivity during curing can be obtained, and have completed the present invention.

[0009] According to the present invention, Epoxy resin, a phenolic resin hardener; A curing accelerator; an inorganic filler including a first inorganic filler and a second inorganic filler; An encapsulating resin composition comprising: the inorganic filler is contained in an amount of 80% by mass or more and 95% by mass or less with respect to the entire encapsulating resin composition, The first inorganic filler is The composite material comprises first spherical alumina particles having a 50% volume cumulative particle size D50 of 10 μm or more and 50 μm or less, and second spherical alumina particles having a 50% volume cumulative particle size D50 of 0.1 μm or more and less than 10 μm. , The second inorganic filler is a composite particle containing aluminum oxide and aluminum borate. the law of nature , the composite particles are composed of small-sized composite particles having a 50% volume cumulative particle size D50 of 0.5 μm or more and 5 μm or less, and large-sized composite particles having a 50% volume cumulative particle size D50 of 5 μm or more and 20 μm or less, the first spherical alumina particles are contained in an amount of 60% by volume or more and 80% by volume or less relative to the total volume of the inorganic filler; the second spherical alumina particles are contained in an amount of 5% by volume or more and 20% by volume or less relative to the total volume of the inorganic filler; the small particle size composite particles are contained in an amount of 5% by volume or more and 15% by volume or less based on the total volume of the inorganic filler; The large particle size composite particles are contained in an amount of 5% by volume or more and 15% by volume or less based on the total volume of the inorganic filler. An encapsulating resin composition is provided.

[0010] Further, according to the present invention, A semiconductor element; an encapsulant that encapsulates the semiconductor element, The electronic device is provided, wherein the encapsulant is made of a cured product of the encapsulating resin composition. [Effects of the Invention]

[0011] According to the present invention, there are provided an encapsulating resin composition which has high fluidity and excellent moldability during molding, and which has high thermal conductivity and excellent heat dissipation properties when cured, and an electronic device which is manufactured using the same and has excellent reliability. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram showing a cross-sectional structure of an example of a double-sided sealed electronic device manufactured using the resin composition of the present embodiment. [Figure 2] FIG. 1 is a diagram showing a cross-sectional structure of an example of a single-sided sealed electronic device manufactured using the resin composition of the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all drawings, similar components are designated by similar reference numerals, and their description will be omitted where appropriate. Furthermore, all drawings are for illustrative purposes only. The shapes and dimensional ratios of each component in the drawings do not necessarily correspond to actual products. In this specification, the notation "a to b" in the description of a numerical range means "a or more and b or less" unless otherwise specified. For example, "5 to 90% by mass" means "5% by mass or more and 90% by mass or less."

[0014] Hereinafter, an embodiment of the present invention will be described. The encapsulating resin composition of the present embodiment (hereinafter may be simply referred to as "resin composition") is a resin material used as an encapsulant for encapsulating a semiconductor element mounted on a substrate, and contains an epoxy resin, a phenolic resin curing agent, a curing accelerator, and an inorganic filler containing a first inorganic filler and a second inorganic filler, wherein the first inorganic filler is alumina particles, and the second inorganic filler is composite particles containing aluminum oxide and aluminum borate.

[0015] The resin composition of the present embodiment contains a combination of alumina particles and aluminum oxide / aluminum borate composite particles as an inorganic filler, thereby achieving both high fluidity during molding and high thermal conductivity of the cured product.

[0016] The components used in the resin composition of this embodiment will be described below.

[0017] (epoxy resin) Examples of epoxy resins used in the semiconductor encapsulation resin composition of this embodiment include crystalline epoxy resins such as bisphenol type epoxy resins, such as bisphenol A type epoxy resins, bisphenol F type epoxy resins, and tetramethylbisphenol F type epoxy resins; biphenyl type epoxy resins, stilbene type epoxy resins, and hydroquinone type epoxy resins; novolac type epoxy resins such as cresol novolac type epoxy resins, phenol novolac type epoxy resins, and naphthol novolac type epoxy resins; phenylene skeleton-containing phenol aralkyl type epoxy resins; biphenylene skeleton-containing phenol aralkyl type epoxy resins; Examples of suitable epoxy resins include phenol aralkyl epoxy resins such as alkyl-type epoxy resins, phenylene skeleton-containing naphthol aralkyl epoxy resins, and alkoxynaphthalene skeleton-containing phenol aralkyl epoxy resins; trifunctional epoxy resins such as triphenolmethane epoxy resins and alkyl-modified triphenolmethane epoxy resins; modified phenol epoxy resins such as dicyclopentadiene-modified phenol epoxy resins and terpene-modified phenol epoxy resins; and heterocycle-containing epoxy resins such as triazine nucleus-containing epoxy resins. These may be used alone or in combination of two or more. Among these, biphenyl-type epoxy resins are preferred because they can maintain the melt viscosity within an optimal range, have good moldability, and are low cost. The epoxy equivalent of the epoxy resin is preferably 90 to 300. If the epoxy equivalent is too low, the reactivity with the curing agent tends to decrease. If the epoxy equivalent is too high, the strength of the cured product of the resin composition tends to decrease.

[0018] The epoxy resin preferably includes at least one of a bisphenol epoxy resin, a biphenyl epoxy resin, a novolac epoxy resin (e.g., an o-cresol novolac epoxy resin), a phenol aralkyl epoxy resin, and a triphenol methane epoxy resin. In order to control the high-temperature elastic modulus, a phenol aralkyl epoxy resin having a biphenylene skeleton is particularly preferred.

[0019] The epoxy resin may contain at least one selected from the group consisting of epoxy resins represented by the following general formula (1), epoxy resins represented by the following general formula (2), epoxy resins represented by the following general formula (3), epoxy resins represented by the following general formula (4), and epoxy resins represented by the following general formula (5). Among these, a more preferred embodiment is one containing at least one selected from the epoxy resins represented by the following general formula (1) and the epoxy resins represented by the following general formula (4).

[0020] [ka]

[0021] In general formula (1), Ar 1 represents a phenylene group or a naphthylene group, and Ar 1 When is a naphthylene group, the glycidyl ether group may be bonded to either the α-position or the β-position. Ar 2 represents any one of a phenylene group, a biphenylene group, and a naphthylene group. R a and R b each independently represents a hydrocarbon group having 1 to 10 carbon atoms. g is an integer from 0 to 5, and h is an integer from 0 to 8. 3 represents the degree of polymerization, and its average value is 1 to 3.

[0022] [ka]

[0023] In general formula (2), A plurality of Rc's each independently represent a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms. n 5 represents the degree of polymerization, and its average value is 0 to 4.

[0024] [ka]

[0025] In general formula (3), Multiple Rs d and R e each independently represents a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms. n 6 represents the degree of polymerization, and its average value is 0 to 4.

[0026] [ka]

[0027] In general formula (4), Multiple Rs f each independently represents a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms. n 7 represents the degree of polymerization, and its average value is 0 to 4.

[0028] [ka]

[0029] In general formula (5), Multiple Rs g each independently represents a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms. n 8 represents the degree of polymerization, and its average value is 0 to 4.

[0030] The number molecular weight of the epoxy resin is not particularly limited and may be appropriately selected from the viewpoints of flowability, curability, etc. For example, the number molecular weight is about 100 to 700. From the viewpoint of flowability, etc., the ICI viscosity of the epoxy resin at 150°C is preferably 0.1 to 5.0 poise. The epoxy resins may be used alone or in combination of two or more.

[0031] The epoxy equivalent of the epoxy resin is preferably 100 to 400 g / eq, more preferably 150 to 350 g / eq. When the encapsulating resin composition contains multiple types of epoxy resins, it is preferable that the epoxy equivalent of the multiple types of epoxy resins as a whole falls within the above numerical range.

[0032] The content of the epoxy resin is not particularly limited, but is preferably 1% by mass or more, and more preferably 2% by mass or more, relative to the total amount of the resin composition. When the lower limit of the blending ratio is within the above range, there is little risk of a decrease in fluidity during the encapsulation process. Furthermore, the upper limit of the blending ratio of the entire resin composition is also not particularly limited, but is preferably 20% by mass or less, and more preferably 15% by mass or less, relative to the total amount of the resin composition. When the upper limit of the blending ratio is within the above range, there is little decrease in the glass transition temperature of the resin composition.

[0033] (Phenol resin hardener) Examples of phenolic resin curing agents used in the resin composition of this embodiment include novolac-type phenolic resins such as phenol novolac resin, cresol novolac resin, bisphenol novolac, and phenol-biphenyl novolac resin; polyvinylphenol; multifunctional phenolic resins such as triphenolmethane-type phenolic resin; modified phenolic resins such as terpene-modified phenolic resin and dicyclopentadiene-modified phenolic resin; phenol aralkyl-type phenolic resins such as phenylene and / or biphenylene skeleton-containing phenol aralkyl resin and phenylene and / or biphenylene skeleton-containing naphthol aralkyl resin; and bisphenol compounds such as bisphenol A and bisphenol F. As the phenolic resin curing agent, one or a combination of two or more of the above specific examples can be used. Of the above specific examples, the phenolic resin curing agent preferably contains a phenylene and / or biphenylene skeleton-containing phenol aralkyl resin. This allows for good curing of the epoxy resin in the resin composition.

[0034] The lower limit of the blending ratio of the phenolic resin curing agent is not particularly limited, but is preferably 0.5% by mass or more, and more preferably 1% by mass or more, based on the total resin composition. If the lower limit of the blending ratio is within the above range, sufficient fluidity can be obtained. The upper limit of the blending ratio of the curing agent is also not particularly limited, but is preferably 15% by mass or less, and more preferably 10% by mass or less, based on the total resin composition. If the upper limit of the blending ratio is within the above range, the fluidity and meltability of the resin composition can be within the desired range.

[0035] Furthermore, the compounding ratio of the epoxy resin to the phenolic resin-based curing agent is preferably such that the equivalent ratio (EP) / (OH) of the number of epoxy groups (EP) in the epoxy resin to the number of phenolic hydroxyl groups (OH) in the phenolic resin-based curing agent is 0.8 or more and 1.3 or less. When the equivalent ratio is within this range, sufficient curing properties can be obtained during molding of the resin composition. Furthermore, when the equivalent ratio is within this range, the fluidity and melting properties of the resin composition can be within desired ranges.

[0036] (curing accelerator) The curing accelerator used in the resin composition of this embodiment is not particularly limited as long as it can accelerate the curing reaction between the above-mentioned phenolic resin and the above-mentioned phenolic resin curing agent. Examples of the curing accelerator include onium salt compounds; organic phosphines such as triphenylphosphine, tributylphosphine, and trimethylphosphine; tetra-substituted phosphonium compounds; phosphobetaine compounds; adducts of phosphine compounds and quinone compounds; adducts of phosphonium compounds and silane compounds; imidazole compounds such as 2-methylimidazole, 2-ethyl-4-methylimidazole (EMI24), 2-phenyl-4-methylimidazole (2P4MZ), 2-phenylimidazole (2PZ), 2-phenyl-4-methyl-5-hydroxyimidazole (2P4MHZ), and 1-benzyl-2-phenylimidazole (1B2PZ); and tertiary amines such as 1,8-diaza-bicyclo[5.4.0]undecene-7 (DBU), triethanolamine, and benzyldimethylamine. These may be used alone or in combination of two or more.

[0037] The content of the curing accelerator is preferably 0.1% by mass or more and 2% by mass or less based on the total amount of the epoxy resin and the phenolic resin curing agent. If the content of the curing accelerator is less than the lower limit, the curing acceleration effect may not be enhanced. On the other hand, if the content is more than the upper limit, problems tend to occur in flowability and moldability, and may also lead to increased production costs.

[0038] (inorganic filler) The resin composition of the present embodiment contains a combination of alumina particles as a first inorganic filler and composite oxide particles as a second inorganic filler. Each inorganic filler will be described below.

[0039] (alumina particles) The alumina particles used in the resin composition of this embodiment have the effect of imparting thermal conductivity to the resin composition. Alumina particles have higher thermal conductivity than other inorganic fillers such as silica particles, facilitating thermal design when used as a sealant. Furthermore, alumina particles are less expensive than other inorganic fillers (e.g., magnesium oxide, boron nitride, aluminum nitride, diamond, etc.) that have higher thermal conductivity than silica particles, and are also easier to increase sphericity and have excellent heat resistance.

[0040] In one embodiment, the alumina particles include first alumina particles having a 50% volume cumulative particle size D50 of 10 to 50 μm as measured by a laser diffraction scattering method.

[0041] In a preferred embodiment, the alumina particles include, in addition to the first alumina particles, second alumina particles having a 50% volume cumulative particle size D50 of 0.1 μm or more and 10 μm or less.

[0042] If the 50% volume cumulative particle diameter D50 of the alumina particles is less than 0.1 μm, the viscosity of the resin composition becomes very high, resulting in poor filling properties and poor workability in the encapsulation process. Furthermore, if the 50% volume cumulative particle diameter D50 of the alumina particles is less than 0.1 μm, the elastic modulus of the cured resin composition decreases, resulting in warping of the resulting package. On the other hand, if the 50% volume cumulative particle diameter D50 of the alumina particles exceeds 50 μm, there is a risk of poor filling. Even if filling is possible, voids will be generated during filling, making this inappropriate. By including a combination of the first and second alumina particles, the encapsulating resin composition of the present invention can achieve both good filling properties and good workability in the encapsulation process.

[0043] When first alumina particles having a 50% volume cumulative particle size D50 of 10 to 50 μm are used in combination with second alumina particles having a 50% volume cumulative particle size D50 of 0.1 μm or more and 10 μm or less, the ratio of the first alumina particles to the total alumina particles is 60 to 100% by volume, and preferably 80 to 100% by volume.

[0044] By using alumina particles having the above particle size distribution, the flowability is improved, and therefore a resin composition suitable as a sealing material can be obtained, which has good workability in the sealing process and reduced filling defects.

[0045] The shape of the alumina particles is not particularly limited, and may be any of spherical, flaky, granular, and powdery.

[0046] In a preferred embodiment, the alumina particles preferably include spherical alumina particles having a sphericity of 0.8 or more, preferably 0.9 or more. Such spherical alumina particles exist in a state close to the closest packing state in the encapsulant, thereby improving the thermal conductivity of the resulting encapsulant. Furthermore, a resin composition containing such spherical alumina has improved fluidity and is easy to handle in the encapsulation process.

[0047] In this specification, "sphericity" is defined as "the ratio of the minimum diameter to the maximum diameter of a particle" in a two-dimensional image observed with a scanning electron microscope (SEM). That is, in this embodiment, this refers to a ratio of the minimum diameter to the maximum diameter of an alumina particle in a two-dimensional image observed with a scanning electron microscope (SEM) of 0.8 or more.

[0048] (composite particle) The encapsulating resin composition of this embodiment contains composite particles containing aluminum oxide and aluminum borate as the second inorganic filler. Examples of the composite particles include composite particles composed of aluminum oxide, aluminum borate, and titanium dioxide, composite particles composed of aluminum oxide, aluminum borate, and tungsten trioxide, or combinations thereof. Commercially available examples of such composite particles include Dipyroxide #7321, #7323, and #7330 manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.

[0049] The 50% volume cumulative particle size D50 of the composite particles that are the second inorganic filler is, for example, 0.5 μm or more and 20 μm or less, and preferably 0.5 μm or more and 15 μm or less.

[0050] In one embodiment, the particle size distribution curve representing the volume-based frequency distribution of the composite particles that are the second inorganic filler has two peaks between 0.5 and 20 μm, and preferably has two peaks between 0.5 and 15 μm.

[0051] The composite particles as the second inorganic filler are not particularly limited and may be spherical, scaly, granular, or powdery, but preferably have a rounded shape without corners, and the closer to a spherical shape the more preferable, which improves the flowability and allows the resin composition to be easily handled in the encapsulation step.

[0052] The amount of the composite particles to be blended is, for example, 1 to 30% by volume, and preferably 5 to 20% by volume, based on the total amount of the inorganic filler (the total of the first and second inorganic fillers). By using an inorganic filler having such a particle size distribution, the flowability is improved, and therefore, a resin composition suitable for use as an encapsulant can be obtained, which has good workability in the encapsulation step and reduced filling defects.

[0053] The inorganic filler in the resin composition in one embodiment can be, for example, as in the following formulation examples: The blending amount in the following formulation examples is the ratio (volume %) to the total amount of inorganic filler used. (Combination example 1) First alumina particles with a 50% volume cumulative particle size D50 of 10 to 50 μm: 70 to 90% by volume Composite particles with a 50% volume cumulative particle size D50 of 0.5 μm to 20 μm: 10 to 30% by volume (Combination example 2) First alumina particles having a 50% volume cumulative particle size D50 of 10 to 50 μm: 70 to 85% by volume Secondary alumina particles with a 50% volume cumulative particle size D50 of 0.1 μm or more and 10 μm or less: 5 to 15% by volume Composite particles with a 50% volume cumulative particle size D50 of 0.5 μm or more and 20 μm or less: 5 to 15% by volume (Combination example 3) Primary alumina particles with a 50% volume cumulative particle size D50 of 10-50 μm: 70-85 Small particle size composite particles with a 50% volume cumulative particle size D50 of 0.5 μm to 20 μm: 5 to 15% by volume (Combination example 4) First alumina particles with a 50% volume cumulative particle size D50 of 10 to 50 μm: 60 to 80% by volume Secondary alumina particles with a 50% volume cumulative particle size D50 of 0.1 μm or more and 10 μm or less: 5 to 20% by volume Small particle size composite particles with a 50% volume cumulative particle size D50 of 0.5 μm to 5 μm: 5 to 15% by volume Large particle size composite particles with a 50% volume cumulative particle size D50 of 5 μm or more and 20 μm or less: 5 to 15% by volume

[0054] (Other inorganic fillers) The resin composition of this embodiment may contain other inorganic fillers in addition to the alumina particles and composite oxide particles described above. Examples of other inorganic fillers include silica such as fused crushed silica, fused spherical silica, crystalline silica, and secondary agglomerated silica; calcium carbonate, magnesium oxide, silicon nitride, aluminum nitride, boron nitride, titanium oxide, silicon carbide, aluminum hydroxide, magnesium hydroxide, titanium white, talc, clay, mica, and glass fiber. The particle shape of these fillers is preferably as spherical as possible, and the loading amount can be increased by mixing fillers of different particle sizes. When other inorganic fillers are used, the amount of the fillers to be added is preferably 0.5 to 5% by volume based on the total volume of the inorganic fillers.

[0055] The content of the inorganic filler is, for example, 80 to 95 mass %, preferably 85 to 95 mass %, and more preferably 88 to 95 mass %, based on the total mass of the resin composition. The amount of inorganic filler refers to the total amount of the first inorganic filler, the second inorganic filler, and, if used, the other inorganic fillers. By using the inorganic filler in the above-mentioned amount, the resulting resin composition has high thermal conductivity and excellent workability.

[0056] (Other additives) The resin composition of this embodiment may further contain other additives in addition to the above-mentioned components, as needed. Examples of other additives include coupling agents, fluidity imparting agents, mold release agents, ion scavengers, stress reducing agents, colorants, and flame retardants. Representative components are described below.

[0057] (coupling agent) Specific examples of coupling agents include vinyl silanes such as vinyltrimethoxysilane and vinyltriethoxysilane; epoxy silanes such as 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 3-glycidoxypropyltriethoxysilane; styryl silanes such as p-styryltrimethoxysilane; methacryl silanes such as 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, and 3-methacryloxypropyltriethoxysilane; acryl silanes such as 3-acryloxypropyltrimethoxysilane; N-2-(aminoethyl)-3-amino Examples of suitable coupling agents include aminosilanes such as N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, and phenylaminopropyltrimethoxysilane; isocyanurate silanes; alkyl silanes; ureidosilanes such as 3-ureidopropyltrialkoxysilane; mercaptosilanes such as 3-mercaptopropylmethyldimethoxysilane and 3-mercaptopropyltrimethoxysilane; isocyanate silanes such as 3-isocyanatopropyltriethoxysilane; titanium compounds; aluminum chelates; and aluminum / zirconium compounds. The coupling agent may be one or more of the above specific examples.

[0058] (fluidity imparting agent) The fluidity imparting agent acts to suppress the reaction of non-latent curing accelerators, such as phosphorus-containing curing accelerators, during melt-kneading of the resin composition, thereby improving the productivity of the resin composition. Specific examples of the fluidity imparting agent include compounds in which hydroxyl groups are bonded to two or more adjacent carbon atoms constituting an aromatic ring, such as catechol, pyrogallol, gallic acid, gallic acid esters, 1,2-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, and derivatives thereof.

[0059] (mold release agent) Specific examples of the release agent include natural waxes such as carnauba wax, synthetic waxes such as Montan acid ester wax and oxidized polyethylene wax, higher fatty acids such as zinc stearate and metal salts thereof, paraffin, carboxylic acid amides such as erucic acid amide, etc. One or more of the above specific examples can be blended as the release agent.

[0060] (ion scavenger) Specific examples of the ion scavenger include hydrotalcites such as hydrotalcite and hydrotalcite-like substances, and hydrated oxides of elements selected from magnesium, aluminum, bismuth, titanium, and zirconium. One or more of the above specific examples can be blended as the ion scavenger.

[0061] (low stress agent) Specific examples of the low stress agent include silicone compounds such as silicone oil and silicone rubber, polybutadiene compounds, and acrylonitrile-butadiene copolymer compounds such as acrylonitrile-carboxyl group-terminated butadiene copolymer compounds. One or more of the above specific examples can be blended as the low stress agent.

[0062] (coloring agent) Specific examples of the colorant include carbon black, red iron oxide, titanium oxide, etc. One or more of the above specific examples of the colorant may be blended.

[0063] (Flame retardant) Specific examples of the flame retardant include aluminum hydroxide, magnesium hydroxide, zinc borate, zinc molybdate, phosphazene, carbon black, etc. One or more of the above specific examples can be blended as the flame retardant.

[0064] (Production of encapsulating resin composition) The resin composition of this embodiment can be produced by uniformly mixing the above components and optional additives to a predetermined content using a mixer or blender such as a tumbler mixer or Henschel mixer, and then kneading the mixture while heating using a kneader, roll, disperser, azimuth homomixer, planetary mixer, or the like. The kneading temperature must be within a range in which a curing reaction does not occur, and although this varies depending on the composition of the epoxy resin and phenolic resin curing agent, melt-kneading at approximately 70 to 150°C is preferred. After kneading, the mixture may be cooled and solidified, and processed into powder, granules, tablets, or sheets.

[0065] A method for obtaining a powdery resin composition includes, for example, pulverizing the kneaded material using a pulverizer. The kneaded material may be formed into a sheet and then pulverized. Examples of the pulverizer that can be used include a hammer mill, a stone mill, and a roll crusher.

[0066] As a method for obtaining a granular or powdery resin composition, for example, a granulation method represented by a hot-cut method can be used, in which a die having a small diameter is provided at the outlet of a kneading device and the molten kneaded material discharged from the die is cut to a predetermined length with a cutter, etc. In this case, after obtaining a granular or powdery resin composition by a granulation method such as the hot-cut method, it is preferable to degas the resin composition before the temperature of the resin composition drops significantly.

[0067] The resin composition of the present embodiment produced as described above has a thermal diffusivity of 2.52 mm when measured by the laser flash method in a cured product. 2 / sec or more, preferably 2.55 mm 2 / sec or more, and more preferably 2.57 mm 2 / sec or more.

[0068] Furthermore, the thermal conductivity of the cured product of the resin composition of this embodiment, as measured by a laser flash method, is 8.32 W / m·K or more, preferably 8.42 W / m·K or more, more preferably 8.48 W / m·K or more, and particularly preferably 8.58 W / m·K or more.

[0069] The melt viscosity of the resin composition of this embodiment is, for example, 1 to 150 Pa·s or more, and preferably 5 to 100 Pa·s. If the melt viscosity is less than the above value, the inorganic filler may settle, and a uniform molded product may not be obtained. If the melt viscosity exceeds the above value, the filling ability may decrease, and voids or unfilled portions may occur. Here, the melt viscosity is the melt viscosity of the resin composition when measured using a high-speed flow tester with a slit diameter of 0.5 mm, a measurement temperature of 175°C, and a load of 40 kgf.

[0070] (electronic equipment) An example of an electronic device manufactured using the encapsulating resin composition according to this embodiment as a encapsulant will be described. FIG. 1 is a cross-sectional view showing a double-sided sealed electronic device 100 according to this embodiment. The semiconductor device 100 of this embodiment comprises an electronic element 20, a bonding wire 40 connected to the electronic element 20, and an encapsulant 50, the encapsulant 50 being composed of a cured product of the resin composition described above.

[0071] More specifically, the electronic element 20 is fixed onto the substrate 30 via the die attach material 10, and the electronic device 100 has outer leads 34 connected via bonding wires 40 to electrode pads (not shown) provided on the electronic element 20. The bonding wires 40 can be set taking into consideration the electronic element 20 to be used, and for example, Cu wires can be used.

[0072] 2 is a diagram showing the cross-sectional structure of an example of a single-sided sealed electronic device obtained by sealing an electronic element mounted on a circuit board using the resin composition of this embodiment. An electronic element 401 is fixed to a circuit board 408 via a die attach material 402. Electrode pads 407 of the electronic element 401 and electrode pads 407 on the circuit board 408 are connected by bonding wires 404. The surface of the circuit board 408 on which the electronic element 401 is mounted is sealed with a sealing material 406 formed from a cured product of the resin composition of this embodiment. The electrode pads 407 on the circuit board 408 are internally joined to solder balls 409 on the non-sealed side of the circuit board 408.

[0073] A method for manufacturing a semiconductor device using the encapsulating resin composition according to this embodiment will be described below. The semiconductor device according to this embodiment is manufactured, for example, by the steps of obtaining an encapsulating resin composition by the above-described method for manufacturing an encapsulating resin composition, mounting an electronic element on a substrate, and encapsulating the electronic element using the encapsulating resin composition. Techniques that can be used to form the encapsulant include, for example, transfer molding, compression molding, and injection molding. The encapsulating step is performed by curing the resin composition at a temperature of about 80°C to 200°C for about 10 minutes to 10 hours.

[0074] The types of electronic elements to be encapsulated include, but are not limited to, semiconductor elements such as integrated circuits, large-scale integrated circuits, transistors, thyristors, diodes, and solid-state imaging devices. The resulting electronic device forms include, but are not limited to, dual in-line packages (DIPs), plastic leaded chip carriers (PLCCs), quad flat packages (QFPs), low-profile quad flat packages (LQFPs), small outline packages (SOPs), small outline J-lead packages (SOJs), thin small outline packages (TSOPs), thin quad flat packages (TQFPs), tape carrier packages (TCPs), ball grid arrays (BGAs), and chip-sized packages (CSPs).

[0075] Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various other configurations can also be adopted. Examples of embodiments are given below. 1. Epoxy resin; a phenolic resin hardener; A curing accelerator; an inorganic filler including a first inorganic filler and a second inorganic filler; An encapsulating resin composition comprising: the first inorganic filler is alumina particles, the second inorganic filler is a composite particle containing aluminum oxide and aluminum borate; Sealing resin composition. 2. The encapsulating resin composition according to 1., wherein the second inorganic filler includes composite particles composed of aluminum oxide, aluminum borate, and titanium dioxide, or composite particles composed of aluminum oxide, aluminum borate, and tungsten trioxide, or a combination thereof. 3. The encapsulating resin composition according to 1. or 2., wherein the second inorganic filler has a 50% volume cumulative particle size D50 of 0.5 μm or more and 20 μm or less. 4. The encapsulating resin composition according to any one of 1. to 3., wherein a particle size distribution curve representing a volume-based frequency distribution of the second inorganic filler has two peaks between 0.5 and 20 μm. 5. The encapsulating resin composition according to any one of 1. to 4., wherein the second inorganic filler has a rounded shape without any corners. 6. The encapsulating resin composition according to any one of 1. to 5., wherein the alumina particles include spherical alumina. 7. The encapsulating resin composition according to any one of 1. to 6., wherein the alumina particles include alumina particles having a 50% volume cumulative particle size D50 of 10 μm or more and 50 μm or less. 8. The encapsulating resin composition according to 7., wherein the alumina particles further include alumina particles having a 50% volume cumulative particle size D50 of 0.1 μm or more and less than 10 μm. 9. The encapsulating resin composition according to any one of 1 to 8, wherein the inorganic filler is contained in an amount of 80% by mass or more and 95% by mass or less based on the total mass of the encapsulating resin composition. 10. The encapsulating resin composition according to any one of 1 to 9, wherein the melt viscosity of the encapsulating resin composition is 1 Pa s or more and 150 Pa s or less, as measured using a Koka type flow tester with a slit diameter of φ0.5 mm, a measurement temperature of 175°C, and a load of 40 kgf. 11. The encapsulating resin composition according to any one of 1. to 10., wherein the inorganic filler further includes at least one selected from silica, calcium carbonate, aluminum hydroxide, magnesium oxide, boron nitride, aluminum nitride, talc, and mica. 12. The encapsulating resin composition according to any one of 1. to 11., further comprising a stress reducing agent. 13. A semiconductor element; an encapsulant that encapsulates the semiconductor element, 13. An electronic device, wherein the encapsulant is a cured product of the encapsulating resin composition according to any one of 1. to 12. [Example]

[0076] EXAMPLES The present invention will be described below with reference to examples and comparative examples, but the present invention is not limited to these.

[0077] The components used in the examples and comparative examples are shown below. (epoxy resin) Epoxy resin 1: Biphenyl-type epoxy resin having the following structural formula (Mitsubishi Chemical Corporation, YX4000HK) [ka]

[0078] (Phenol resin hardener) Hardener 1: Novolac phenolic resin (Sumitomo Bakelite Co., Ltd., PR-55617)

[0079] (alumina particles) Alumina particles 1: spherical alumina (average particle size (D50) 42 μm) Alumina particles 2: spherical alumina (average particle size (D50) 0.6 μm)

[0080] (composite particle) Composite particle 1: Dipyroxide #7321 (manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd., a composite having a composition of 90-99% aluminum oxide, 1-5% aluminum borate, and <1% titanium dioxide (rutile), average particle size (D50) 1 μm) Composite particle 2: Dipyroxide #7323 (manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd., a composite having a composition of 90-99% aluminum oxide, 1-5% aluminum borate, and <1% tungsten trioxide, average particle size (D50) 3 μm) Composite particle 3: Dipyroxide #7330 (manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd., a composite having a composition of 90-99% aluminum oxide, 1-5% aluminum borate, and <1% tungsten trioxide, average particle size (D50) 10 μm)

[0081] (coupling agent) Coupling agent 1: N-phenylaminopropyltrimethoxysilane (CF-4083, manufactured by Toray Dow Corning Co., Ltd.)

[0082] (curing accelerator) Curing accelerator 1: A curing accelerator represented by the following formula (P1) (tetraphenylphosphonium bis(naphthalene-2,3-dioxy)phenylsilicate) [ka]

[0083] (wax) Wax 1: Carnauba wax (TOWAX-132, manufactured by Toagosei Co., Ltd.) Wax 2: Erucic acid amide (NOF Corporation, Alflow P-10)

[0084] (coloring agent) Colorant 1: Carbon black (Tokai Carbon Co., Ltd., ERS-2001) (ion scavenger) Ion scavenger 1: Magnesium aluminum hydroxide carbonate hydrate (Kyowa Chemical Industry Co., Ltd., DHT-4H)

[0085] (low stress agent) Low-stress agent 1: Epoxy polyether modified silicone oil (Dow Corning Toray, FZ-3730)

[0086] ( Reference Examples 1 to 6, Examples 7 to 8 , Comparative Example 1) The raw materials shown in Table 1 were pulverized and mixed for 5 minutes in a supermixer. The mixed raw materials were then melt-kneaded in a co-rotating twin-screw extruder with a 65 mm inner diameter cylinder at a screw speed of 400 rpm and a resin temperature of 100°C. The melt-kneaded resin composition was then fed from above a 20 cm diameter rotor at a rate of 2 kg / hr. The rotor was rotated at 3000 rpm, and the centrifugal force generated forced the resin composition through multiple small holes (1.2 mm diameter) on the outer periphery of a cylinder heated to 115°C. The resin composition was then cooled to obtain a granular encapsulating resin composition. The resulting granular encapsulating resin composition was stirred for 3 hours in an air stream at 15°C and a relative humidity of 55% RH.

[0087] (Evaluation of kneadability) When the mixed raw materials were melt-kneaded at a resin temperature of 100°C in a co-rotating twin-screw extruder with a cylinder inner diameter of 65 mm, those that could be kneaded at a screw rotation speed of 200 rpm were rated as "Good" for kneadability, and those that could not maintain a rotation speed of 200 rpm due to an increase in the rotation torque of the twin-screw extruder were rated as "Good." The results are shown in Table 1.

[0088] The encapsulating resin compositions obtained by the above method were evaluated for the following items by the methods described below. (fluidity (spiral flow)) Using a low-pressure transfer molding machine (KTS-15, manufactured by Kotaki Seiki Co., Ltd.), the resin composition was injected into a spiral flow measurement mold conforming to EMMI-1-66 under conditions of a mold temperature of 175°C, an injection pressure of 6.9 MPa, and a dwell time of 120 seconds, and the flow length was measured. Spiral flow is an index of fluidity, with a larger value indicating better fluidity. The unit is cm.

[0089] (High-grade viscosity) Using a high-performance flow tester (Shimadzu Corporation, CFT-500C), the temperature was 175°C and the load was 40 kgf (piston area 1 cm). 2 The viscosity was measured under the test conditions of a die hole diameter of 0.50 mm and a die length of 1.00 mm. The unit of viscosity is Pa·s.

[0090] (thermal diffusion) The obtained encapsulating resin composition was heat-treated at 180°C and 10 MPa for 40 minutes to obtain a cured product. The thermal diffusivity (m 2 / s) were measured, and the results are shown in Table 1.

[0091] [Table 1]

[0092] The encapsulating resin compositions of the examples had a good balance of thermal conductivity and fluidity, and could be suitably used as encapsulants. [Explanation of symbols]

[0093] 10 Die attach material 20 Electronic Elements 30 Base material 32 die pad 34 outer lead 40 Bonding Wire 50 Encapsulating material 100 Electronic equipment 401 Electronic Elements 402 Die attach material 404 Bonding Wire 406 Sealant 407 Electrode Pads 408 Circuit Board 409 Solder ball

Claims

1. Epoxy resin, a phenolic resin hardener; A curing accelerator; an inorganic filler including a first inorganic filler and a second inorganic filler; An encapsulating resin composition comprising: the inorganic filler is contained in an amount of 80% by mass or more and 95% by mass or less with respect to the entire encapsulating resin composition, the first inorganic filler comprises first spherical alumina particles having a 50% volume cumulative particle diameter D50 of 10 μm or more and 50 μm or less, and second spherical alumina particles having a 50% volume cumulative particle diameter D50 of 0.1 μm or more and less than 10 μm; the second inorganic filler is a composite particle containing aluminum oxide and aluminum borate, the composite particles are composed of small-sized composite particles having a 50% volume cumulative particle diameter D50 of 0.5 μm or more and 5 μm or less, and large-sized composite particles having a 50% volume cumulative particle diameter D50 of 5 μm or more and 20 μm or less, the first spherical alumina particles are contained in an amount of 60% by volume or more and 80% by volume or less based on the total volume of the inorganic filler; the second spherical alumina particles are contained in an amount of 5% by volume or more and 20% by volume or less based on the total volume of the inorganic filler; the small particle size composite particles are contained in an amount of 5% by volume or more and 15% by volume or less based on the total volume of the inorganic filler; The large particle size composite particles are contained in an amount of 5% by volume or more and 15% by volume or less based on the total volume of the inorganic filler. Sealing resin composition.

2. 2. The encapsulating resin composition according to claim 1, wherein the second inorganic filler comprises composite particles composed of aluminum oxide, aluminum borate, and titanium dioxide, composite particles composed of aluminum oxide, aluminum borate, and tungsten trioxide, or a combination thereof.

3. 3. The encapsulating resin composition according to claim 1, wherein the second inorganic filler has a 50% volume cumulative particle size D50 of 0.5 μm or more and 20 μm or less.

4. 4. The encapsulating resin composition according to claim 1, wherein a particle size distribution curve representing a volume-based frequency distribution of the second inorganic filler has two peaks between 0.5 and 20 μm.

5. The encapsulating resin composition according to claim 1 , wherein the second inorganic filler has a rounded shape without corners.

6. 6. The encapsulating resin composition according to claim 1, wherein the melt viscosity of the encapsulating resin composition is 1 Pa s or more and 150 Pa s or less, as measured using a high-speed flow tester with a slit diameter of 0.5 mm, a measurement temperature of 175°C, and a load of 40 kgf.

7. 7. The encapsulating resin composition according to claim 1, wherein the inorganic filler further comprises at least one selected from the group consisting of silica, calcium carbonate, aluminum hydroxide, magnesium oxide, boron nitride, aluminum nitride, talc, and mica.

8. The encapsulating resin composition according to claim 1 , further comprising a stress reducing agent.

9. A semiconductor element; an encapsulant that encapsulates the semiconductor element, An electronic device, wherein the encapsulant comprises a cured product of the encapsulating resin composition according to claim 1 .

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