JP7276151B2 - EPOXY RESIN COMPOSITION FOR BALL GRID ARRAY PACKAGE SEALING, EPOXY RESIN CURED MATERIAL, AND ELECTRONIC PARTS DEVICE - Google Patents

Description

TECHNICAL FIELD The present disclosure relates to an epoxy resin composition for encapsulating a ball grid array package, an epoxy resin cured product, and an electronic component device.

In recent years, the demand for high-density mounting has increased rapidly due to the miniaturization and thinning of electronic equipment. For this reason, in place of the conventional pin-insertion type semiconductor package, the surface-mount type suitable for high-density mounting has become mainstream. A surface mount type semiconductor package is mounted by directly soldering onto a printed circuit board or the like. As a general mounting method, there is a method of mounting by heating the entire semiconductor package by an infrared reflow method, a vapor phase reflow method, a solder dipping method, or the like.

In recent years, among surface-mounted semiconductor packages, area-mounted packages such as ball grid arrays (hereinafter also referred to as BGAs) have been widely used in order to further increase the mounting density. The BGA package is a single-sided resin-sealed package in which the surface of the substrate on which the semiconductor element is mounted is sealed with a resin composition. Epoxy resin compositions are widely used as resin compositions for encapsulation from the viewpoint of the balance of properties such as moldability, electrical properties, moisture resistance, heat resistance, mechanical properties, and adhesiveness to insert products. there is

On the other hand, in recent years, in the field of electronic components, speeding up and densification have progressed, and along with this, the amount of heat generated by electronic components has increased remarkably. There is also an increasing demand for electronic components that operate at high temperatures. Therefore, plastics used for electronic parts, particularly hardened epoxy resins, are required to have improved thermal conductivity. Particularly in BGA packages, high thermal conductivity is required for sealing resin compositions due to demands for miniaturization and high density. In BGA packages, etc., as a method of improving the thermal conductivity of the cured product of epoxy resin, a method using a high thermal conductive inorganic filler such as alumina, a low viscosity resin and a small amount of fine silica particles are used in combination with the inorganic filler. A method of increasing the filling amount of the material has been reported (see, for example, Patent Document 1).

Japanese Patent No. 4188634

However, if the filling amount of alumina in the epoxy resin composition is increased for the purpose of increasing the thermal conductivity, the fluidity may decrease and the moldability may be impaired. In Patent Document 1, a small amount of finely divided silica is mixed with an alumina filler, and a specific biphenyl-type epoxy resin having a relatively low viscosity is used to achieve high filling of the filler. However, the method of Patent Literature 1 has a problem in achieving both thermal conductivity and fluidity.

Accordingly, the present disclosure provides an epoxy resin composition for encapsulating a BGA package that has excellent fluidity and excellent thermal conductivity when cured, an epoxy resin cured product obtained by curing the epoxy resin composition, and the cured epoxy resin. An object of the present invention is to provide an electronic component device including an element sealed with an object.

Means for solving the above problems include the following embodiments.
<1> An epoxy resin containing a bisphenol F type epoxy resin, a curing agent, and alumina particles and not containing silica particles, or containing alumina particles and silica particles, with respect to the total amount of alumina particles and silica particles, 0 mass An epoxy resin composition for encapsulating a ball grid array package, containing an inorganic filler containing more than 15% by mass of % and a plasticizer, wherein the content of the inorganic filler is 75% by volume to 84% by volume.
<2> The epoxy resin composition for encapsulating a ball grid array package according to <1>, wherein the epoxy resin further contains a biphenyl type epoxy resin.
<3> The inorganic filler contains alumina particles and does not contain silica particles, or contains alumina particles and contains silica particles more than 0% by mass and 10% by mass or less with respect to the total amount of alumina particles and silica particles, < The epoxy resin composition for encapsulating a ball grid array package according to 1> or <2>.
<4> The epoxy resin composition for encapsulating a ball grid array package according to any one of <1> to <3>, wherein the curing agent contains a phenolic curing agent having a hydroxyl equivalent of 150 g/eq or less.
<5> The epoxy resin for encapsulating a ball grid array package according to any one of <1> to <4>, wherein the curing agent contains a phenolic resin having 3 or more phenolic hydroxyl groups in one molecule. Composition.
<6> The epoxy resin composition for encapsulating a ball grid array package according to any one of <1> to <5>, wherein the curing agent contains a triphenylmethane-type phenolic resin.
<7> The epoxy resin composition for encapsulating a ball grid array package according to any one of <1> to <6>, wherein the inorganic filler has a porosity of 18% by volume or less.
<8> In the volume-based particle size distribution of the inorganic filler, the proportion of particles having a particle diameter of 1 µm or less is 9 vol% or more, and the proportion of particles having a particle diameter of more than 1 µm and 10 µm or less is 45 vol% or less. Any one of <1> to <7>, wherein the proportion of particles having a particle diameter of more than 10 μm and 30 μm or less is 20% by volume or more, and the proportion of particles having a particle diameter of more than 30 μm is 18% by volume or more. The epoxy resin composition for encapsulating a ball grid array package according to the above item.
<9> In the volume-based particle size distribution of the inorganic filler, the proportion of particles having a particle diameter of 1 µm or less is 11 vol% or more, and the proportion of particles having a particle diameter of more than 1 µm and 10 µm or less is 40 vol% or less. The ball grid array package sealing according to <8>, wherein the proportion of particles having a particle diameter of more than 10 μm and 30 μm or less is 22% by volume or more, and the proportion of particles having a particle diameter of more than 30 μm is 20% by volume or more. epoxy resin composition for
<10> A cured epoxy resin obtained by curing the epoxy resin composition for encapsulating a ball grid array package according to any one of <1> to <9>.
<11> An electronic component device, comprising an element and the epoxy resin cured product according to <10> sealing the element, and having a form of a ball grid array package.

According to the present disclosure, an epoxy resin composition for encapsulating a BGA package that has excellent fluidity and excellent thermal conductivity when cured, an epoxy resin cured product obtained by curing the epoxy resin composition, and the cured epoxy resin An electronic component device is provided that includes an element encapsulated by an object.

DETAILED DESCRIPTION OF THE INVENTION Embodiments for carrying out the present invention will be described in detail below. However, the present invention is not limited to the following embodiments. In the following embodiments, the constituent elements (including element steps and the like) are not essential unless otherwise specified. The same applies to numerical values and their ranges, which do not limit the present invention.

In the present disclosure, the term "process" includes a process that is independent of other processes, and even if the purpose of the process is achieved even if it cannot be clearly distinguished from other processes. .
In the present disclosure, the numerical range indicated using "-" includes the numerical values before and after "-" as the minimum and maximum values, respectively.
In the numerical ranges described step by step in the present disclosure, the upper limit or lower limit of one numerical range may be replaced with the upper or lower limit of another numerical range described step by step. . Moreover, in the numerical ranges described in the present disclosure, the upper or lower limits of the numerical ranges may be replaced with the values shown in the examples.
In the present disclosure, each component may contain multiple types of applicable substances. When there are multiple types of substances corresponding to each component in the composition, the content rate or content of each component is the total content rate or content of the multiple types of substances present in the composition unless otherwise specified. means quantity.
Particles corresponding to each component in the present disclosure may include a plurality of types. When multiple types of particles corresponding to each component are present in the composition, the particle size of each component means a value for a mixture of the multiple types of particles present in the composition, unless otherwise specified.

<Epoxy resin composition for BGA package sealing>
The epoxy resin composition for BGA package sealing of the present disclosure (hereinafter also simply referred to as the epoxy resin composition) contains an epoxy resin containing a bisphenol F-type epoxy resin, a curing agent, alumina particles and does not contain silica particles. , an inorganic filler containing alumina particles and silica particles more than 0% by mass and 15% by mass or less with respect to the total amount of alumina particles and silica particles, and a plasticizer, and the content of the inorganic filler is 75% to 84% by volume.

The epoxy resin composition of the present disclosure has excellent fluidity and excellent thermal conductivity when cured. Although the reason is not clear, it can be considered as follows. In general, higher alumina particle loading in the epoxy resin composition results in higher thermal conductivity. However, as the alumina particles are highly packed, the fluidity of the composition is lowered, which causes wire flow and the like. On the other hand, since the epoxy resin composition of the present disclosure contains a bisphenol F-type epoxy resin and a plasticizer, it is considered that the fluidity can be easily secured even when the composition contains a high proportion of alumina particles. . Furthermore, it is considered that this makes it possible to increase the amount of the inorganic filler and further improve the thermal conductivity when cured.

The epoxy resin composition of the present disclosure is used for sealing BGA packages. A BGA package is a semiconductor package in which a plurality of metal bumps are arranged in a grid pattern on the substrate of the package. A BGA package is manufactured by mounting an element on the front surface of a substrate on which metal bumps are formed on the back surface, connecting the element and wiring formed on the substrate by bumps or wire bonding, and then sealing the element. A CSP (Chip Size Package), in which the outer diameter is reduced to the same extent as the device, is also a form of BGA package.

[Epoxy resin]
The epoxy resin composition of the present disclosure contains an epoxy resin including a bisphenol F type epoxy resin. The epoxy resin composition may contain an epoxy resin other than the bisphenol F type epoxy resin.

(Bisphenol F type epoxy resin)
In the present disclosure, a bisphenol F type epoxy resin refers to a substituted or unsubstituted diglycidyl ether of bisphenol F. The bisphenol F type epoxy resin may be used singly or in combination of two or more.

Examples of bisphenol F type epoxy resins include epoxy resins represented by the following general formula (I).

In general formula (I), R1 to R8 represent a hydrogen atom or a substituted or unsubstituted monovalent organic group having 1 to 18 carbon atoms, and all of them may be the same or different. n is the average value and represents a number from 0 to 10.

The bisphenol F type epoxy resin represented by the general formula (I) can be obtained by reacting a bisphenol F compound with epichlorohydrin by a known method.

In general formula (I), R1 to R8 are a hydrogen atom, an alkyl group having 1 to 18 carbon atoms such as a methyl group, an ethyl group, a propyl group, a butyl group, an isopropyl group, an isobutyl group, a t-butyl group, and a vinyl alkenyl groups having 1 to 18 carbon atoms such as groups, allyl groups and butenyl groups, and aryl groups, preferably hydrogen atoms or methyl groups.

In general formula (I), n is an average value and represents a number from 0 to 10, preferably a number from 0 to 4. When n is 10 or less, the melt viscosity of the resin component does not become too high, and the viscosity of the epoxy resin composition during melt molding decreases, resulting in poor filling, deformation of the bonding wire (gold wire that connects the element and the lead), and the like. tend to be suppressed.

Examples of bisphenol F type epoxy resins include epoxy resins mainly composed of diglycidyl ether of 4,4′-methylenebis(2,6-dimethylphenol), 4,4′-methylenebis(2,3,6-trimethyl Examples thereof include epoxy resins containing diglycidyl ether of phenol as a main component, and epoxy resins containing diglycidyl ether of 4,4'-methylenebisphenol as a main component. Among them, an epoxy resin containing diglycidyl ether of 4,4'-methylenebis(2,6-dimethylphenol) as a main component is preferable. As a bisphenol F type epoxy resin, YSLV-80XY (Nippon Steel & Sumikin Chemical Co., Ltd., trade name) and the like are commercially available.

The content of the bisphenol F type epoxy resin is not particularly limited, and is preferably 10% by mass or more, more preferably 20% by mass or more, and even more preferably 25% by mass or more based on the total amount of the epoxy resin. The content of the bisphenol F type epoxy resin may be 100% by mass or less, 75% by mass or less, or 50% by mass or less.

The epoxy equivalent of the bisphenol F type epoxy resin is not particularly limited. From the viewpoint of the balance of various properties such as moldability, reflow resistance and electrical reliability, the epoxy equivalent of the bisphenol F type epoxy resin is preferably 100 g/eq to 1000 g/eq, more preferably 150 g/eq to 500 g/eq. eq is more preferred. Let the epoxy equivalent of an epoxy resin be the value measured by the method according to JISK7236:2009. The same applies hereinafter.

When the bisphenol F type epoxy resin is solid, its softening point or melting point is not particularly limited. The softening point or melting point of the bisphenol F type epoxy resin is preferably 40° C. to 180° C. from the viewpoint of moldability and reflow resistance, and 50° C. from the viewpoint of handling during preparation of the epoxy resin composition. ~130°C is more preferred. The melting point of the epoxy resin is a value measured by differential scanning calorimetry (DSC), and the softening point of the epoxy resin is a value measured by a method (ring and ball method) according to JIS K 7234:1986. The same applies hereinafter.

(biphenyl type epoxy resin)
The epoxy resin composition may contain a biphenyl type epoxy resin in addition to the bisphenol F type epoxy resin. The biphenyl-type epoxy resin is not particularly limited as long as it is an epoxy resin having a biphenyl skeleton. Examples thereof include epoxy resins represented by the following general formula (II).

In general formula (II), R1 to R8 represent a hydrogen atom or a substituted or unsubstituted monovalent organic group having 1 to 18 carbon atoms, and all of them may be the same or different. n is the average value and represents a number from 0 to 10.

The biphenyl-type epoxy resin represented by the general formula (II) can be obtained by reacting a biphenol compound with epichlorohydrin by a known method.

In the general formula (II), R1 to R8 are a hydrogen atom, an alkyl group having 1 to 18 carbon atoms such as a methyl group, an ethyl group, a propyl group, a butyl group, an isopropyl group, an isobutyl group, a t-butyl group, and a vinyl alkenyl groups having 1 to 18 carbon atoms such as groups, allyl groups and butenyl groups, and aryl groups, preferably hydrogen atoms or methyl groups.

In general formula (II), n is an average value and represents a number from 0 to 10, preferably a number from 0 to 4.

Biphenyl-type epoxy resins include, for example, 4,4′-bis(2,3-epoxypropoxy)biphenyl or 4,4′-bis(2,3-epoxypropoxy)-3,3′,5,5′- Epoxy resin mainly composed of tetramethylbiphenyl, obtained by reacting epichlorohydrin with 4,4'-biphenol or 4,4'-(3,3',5,5'-tetramethyl)biphenol An epoxy resin etc. are mentioned. Among them, an epoxy resin containing 4,4'-bis(2,3-epoxypropoxy)-3,3',5,5'-tetramethylbiphenyl as a main component is preferable. YX-4000 (Mitsubishi Chemical Co., Ltd., trade name), YL-6121H (Mitsubishi Chemical Co., Ltd., trade name), etc. are commercially available as biphenyl-type epoxy resins.

When the epoxy resin contains a biphenyl-type epoxy resin, the content of the biphenyl-type epoxy resin is not particularly limited. % by mass or more is more preferable. The content of the biphenyl-type epoxy resin may be less than 100% by mass, may be 90% by mass or less, may be 80% by mass or less, or may be 10% by mass or less.

The epoxy equivalent of the biphenyl type epoxy resin is not particularly limited. From the viewpoint of the balance of various properties such as moldability, reflow resistance and electrical reliability, the epoxy equivalent of the biphenyl type epoxy resin is preferably 100 g/eq to 1000 g/eq, more preferably 150 g/eq to 500 g/eq. is more preferable.

When the biphenyl type epoxy resin is solid, its softening point or melting point is not particularly limited. The softening point or melting point of the epoxy resin is preferably 40° C. to 180° C. from the viewpoint of moldability and reflow resistance, and 50° C. to 130° C. from the viewpoint of handleability during preparation of the epoxy resin composition. is more preferable.

(other epoxy resins)
The epoxy resin composition may contain epoxy resins other than the bisphenol F type epoxy resin and the biphenyl type epoxy resin (also referred to as "other epoxy resins"). "Other epoxy resins" are not particularly limited, and epoxy resins having two or more epoxy groups in one molecule are preferred. Epoxy resins having two or more epoxy groups in one molecule include stilbene type epoxy resins, sulfur atom-containing epoxy resins, dicyclopentadiene type epoxy resins, naphthalene type epoxy resins, salicylaldehyde type epoxy resins, naphthols and phenols. type epoxy resins, aralkyl type epoxy resins, diphenylmethane type epoxy resins (excluding bisphenol F type epoxy resins), and triphenylmethane type epoxy resins. "Other epoxy resins" may be used singly or in combination of two or more.

The content of the "other epoxy resin" is not particularly limited, and is preferably 30% by mass or less, more preferably 20% by mass or less, and preferably 10% by mass or less relative to the total amount of the epoxy resin. More preferably, it is particularly preferably 5% by mass or less.

The epoxy equivalent of "other epoxy resins" is not particularly limited. From the viewpoint of the balance of various properties such as moldability, reflow resistance and electrical reliability, the epoxy equivalent of "other epoxy resins" is preferably 100 g/eq to 1000 g/eq, more preferably 150 g/eq to 500 g. /eq is more preferred.

When the "other epoxy resin" is solid, its softening point or melting point is not particularly limited. From the standpoint of moldability and reflow resistance, the softening point or melting point of the "other epoxy resin" is preferably 40°C to 180°C, and from the standpoint of handleability during preparation of the epoxy resin composition, it is 50°C. °C to 130°C is more preferred.

The total content of the epoxy resin in the epoxy resin composition is preferably 0.5% by mass to 50% by mass, more preferably 2% by mass to 30% by mass, from the viewpoint of strength, fluidity, heat resistance, moldability, etc. is more preferable.

The epoxy resin preferably contains an epoxy resin having two or more epoxy groups in one molecule, and may contain an epoxy resin having three or more epoxy groups in one molecule (also referred to as a multifunctional epoxy resin). . As described below, when the epoxy resin composition contains an organic phosphorus compound as a curing accelerator, the content of the polyfunctional epoxy resin is 10 mass with respect to the total mass of the epoxy resin from the viewpoint of controlling package warpage during mounting. % or less, more preferably 5 mass % or less, even more preferably 1 mass % or less, and particularly preferably substantially 0 mass %. The content of "substantially 0% by mass" refers to the content of the polyfunctional epoxy resin to such an extent that no influence on the warpage of the package during mounting is observed.

[Curing agent]
The epoxy resin composition of the present disclosure contains a curing agent. The curing agent is not particularly limited as long as it can react with the epoxy resin. From the viewpoint of improving heat resistance, the curing agent is preferably a compound having two or more phenolic hydroxyl groups in one molecule (hereinafter also referred to as a phenolic curing agent). The phenolic curing agent may be a low-molecular-weight phenolic compound or a phenolic resin obtained by polymerizing a low-molecular-weight phenolic compound. From the viewpoint of thermal conductivity, the phenolic curing agent is preferably a phenolic resin. The curing agents may be used singly or in combination of two or more.

The phenolic curing agent preferably contains a phenolic resin having two or more phenolic hydroxyl groups in one molecule, and a phenolic resin having three or more phenolic hydroxyl groups in one molecule (also referred to as a polyfunctional phenolic resin). It is more preferable to include

The phenolic resin is not particularly limited, and includes biphenylene-type phenolic resin, aralkyl-type phenolic resin, dicyclopentadiene-type phenolic resin, copolymer resin of benzaldehyde-type phenolic resin and aralkyl-type phenolic resin, paraxylene-modified phenolic resin, triphenyl A methane type phenol resin etc. are mentioned. Among them, triphenylmethane type phenolic resin is preferable from the viewpoint of moldability. From the viewpoint of fluidity, paraxylene-modified phenolic resin is preferred.

The paraxylene-modified phenolic resin is not particularly limited as long as it is a phenolic resin obtained using a compound having a paraxylene skeleton as a raw material. For example, it is preferably a phenol resin represented by the following general formula (XV).

Among the phenolic resins represented by the following general formula (XV), XL-225 (Mitsui Chemicals, Inc., trade name), XLC (Mitsui Chemicals, Inc., trade name), MEH-7800 (Meiwa Kasei Co., Ltd., trade name) ) and the like are available as commercial products.

In formula (XV), R ³⁰ represents a monovalent organic group having 1 to 18 carbon atoms, and all of them may be the same or different. i each independently represents an integer of 0 to 3; n is the average value and is a number from 0 to 10. In formula (XV), hydrogen atoms present on the aromatic ring are not shown.

The triphenylmethane-type phenolic resin is not particularly limited as long as it is a phenolic resin obtained using a compound having a triphenylmethane skeleton as a raw material. For example, a phenol resin represented by the following general formula (XVI) is preferred.

Among the phenolic resins represented by the following general formula (XVI), MEH-7500 (Meiwa Kasei Co., Ltd., trade name) in which i is 0 and k is 0 is commercially available.

In formula (XVI), R ³⁰ and R ³¹ each represent 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 the average value and is a number from 0 to 10. In formula (XVI), hydrogen atoms present on the aromatic ring are not shown.

The hydroxyl equivalent weight of the curing agent is not particularly limited, and is preferably 500 g/eq or less, more preferably 400 g/eq or less, and even more preferably 300 g/eq or less. The lower limit of the hydroxyl equivalent weight of the curing agent is preferably 50 g/eq or more, more preferably 60 g/eq or more, and even more preferably 70 g/eq or more. The hydroxyl equivalent weight range of the curing agent is preferably 50 g/eq to 500 g/eq, more preferably 50 g/eq to 400 g/eq, even more preferably 50 g/eq to 300 g/eq.

Above all, the curing agent preferably contains a phenolic curing agent having a hydroxyl equivalent of 150 g/eq or less (hereinafter also referred to as “specific phenolic curing agent”). When the curing agent contains a specific phenolic curing agent, there is a tendency to suppress deterioration in moldability even when an inorganic filler containing alumina particles is contained. One of the reasons for this is thought to be that the cross-linking density increases during curing and the curability improves. Moreover, when the curing agent contains a specific phenolic curing agent, the thermal conductivity of the cured product tends to be further improved. Although the reason for this is not clear, it is presumed that the relatively small molecular weight between cross-linking points contributes to the thermal conductivity. The hydroxyl equivalent of the specific phenol curing agent is preferably 50 g/eq to 150 g/eq, more preferably 50 g/eq to 120 g/eq, even more preferably 60 g/eq to 110 eq, and 70 g/eq. eq to 110 g/eq is particularly preferred.

The hydroxyl equivalent of the phenol curing agent is a value measured by a method according to JIS K 0070:1992.

When the phenolic curing agent is solid, its melting point or softening point is not particularly limited. The melting point or softening point of the phenolic curing agent is preferably 50°C to 250°C, more preferably 65°C to 200°C, even more preferably 80°C to 170°C.

The melting point or softening point of the phenol curing agent is a value measured in the same manner as the melting point or softening point of the epoxy resin.

The content ratio of the epoxy resin and the curing agent in the epoxy resin composition is the ratio of the number of equivalents of the functional group of the curing agent to the number of equivalents of the epoxy group of the epoxy resin (number of equivalents of the functional group of the curing agent/equivalent weight of the epoxy group number) is preferably set to be in the range of 0.5 to 2.0, more preferably set to be 0.7 to 1.5, and 0.8 to 1.3. It is further preferable to set so that When the ratio is 0.5 or more, curing of the epoxy resin becomes sufficient, and the cured product tends to be excellent in heat resistance, moisture resistance, and electrical properties. Further, when the ratio is 2.0 or less, the amount of functional groups of the curing agent remaining in the cured resin is suppressed, and the electrical properties and moisture resistance tend to be excellent.

[Inorganic filler]
The epoxy resin composition of the present disclosure contains alumina particles and does not contain silica particles, or contains alumina particles and silica particles in an inorganic filler of more than 0% by mass and not more than 15% by mass with respect to the total amount of alumina particles and silica particles. Contains wood. The inorganic filler content is 75% to 84% by volume relative to the total volume of the composition. The inorganic filler may contain inorganic fillers other than alumina particles and silica particles, may contain only alumina particles and silica particles, or may contain only alumina particles. Examples of silica particles include spherical silica and crystalline silica.

The average particle size of the inorganic filler is not particularly limited. The average particle size of the inorganic filler is, for example, preferably 0.1 μm to 80 μm, more preferably 0.3 μm to 50 μm. In the present disclosure, the average particle size of the inorganic filler refers to the average particle size of the alumina particles when the alumina particles are used alone as the inorganic filler, and the inorganic fillers are alumina particles and other inorganic fillers. When used in combination with, it refers to the average particle size of the inorganic filler as a whole. When the average particle size of the inorganic filler is 0.1 μm or more, the increase in viscosity of the epoxy resin composition tends to be suppressed. When the average particle size of the inorganic filler is 80 μm or less, the mixing property between the epoxy resin composition and the inorganic filler is improved, and the state of the package obtained by curing becomes more uniform, which tends to suppress variations in properties. There is a tendency to improve filling properties in a narrower region. The particle size distribution of the inorganic filler preferably has a maximum value within the range of 0.1 μm to 80 μm.

Among them, the average particle size of the alumina particles is, for example, preferably 0.1 μm to 80 μm, more preferably 0.3 μm to 50 μm. When the average particle size of the alumina particles is 0.1 μm or more, the increase in viscosity of the epoxy resin composition tends to be suppressed. When the average particle diameter of the alumina particles is 80 μm or less, the mixability between the epoxy resin composition and the alumina particles is improved, and the state of the package obtained by curing tends to be more uniform and variations in properties are suppressed. Furthermore, there is a tendency for the filling property to be improved in a narrow region.

In particular, from the viewpoint of high thermal conductivity, the average particle size of alumina particles is preferably 1 μm to 50 μm, more preferably 2 μm to 30 μm. Above all, when the average particle size of the alumina particles is 10 μm or more, the thermal conductivity tends to be excellent. It is considered that this is because a heat conduction path is easily formed.

Further, when the inorganic filler contains silica particles, the average particle size of the silica particles is, for example, preferably 0.1 μm to 50 μm, more preferably 0.3 μm to 30 μm, more preferably 0.5 μm to 20 μm. is more preferable. In particular, when the average particle size of the silica particles is 10 μm or more, warping of the package when cured tends to be suppressed. When the average particle size of the silica particles is 50 µm or less, the fluidity tends to be improved.

In the present disclosure, the average particle size of the inorganic filler is measured using a dry particle size distribution meter, or using a wet particle size distribution measuring device in the state of a slurry in which the inorganic filler is dispersed in water or an organic solvent. can be measured. In particular, when particles of 1 μm or less are contained, it is preferable to measure using a wet particle size distribution meter. Specifically, a water slurry with an inorganic filler concentration adjusted to about 0.01% by mass was treated with a bath-type ultrasonic cleaner for 5 minutes, and a laser diffraction particle size analyzer (LA-960, HORIBA, Ltd.) ) can be obtained from the average value of all particles detected using In the present disclosure, the average particle size represents the particle size (D50) when the accumulation from the small size side is 50% in the volume-based particle size distribution.

In one embodiment, from the viewpoint of thermal conductivity, it is preferable to use a combination of alumina particles having an average particle size of 1 μm or more and alumina particles having an average particle size of less than 1 μm. For example, it is preferable to use a combination of alumina particles having an average particle size of 1 μm to 50 μm and alumina particles having an average particle size of 0.1 μm or more and less than 1 μm. It is more preferable to use alumina particles of 1 μm or more and less than 1 μm in combination, and it is further preferable to use alumina particles of 5 μm to 30 μm in average particle size and alumina particles of 0.3 μm to less than 1 μm in average particle size in combination. preferable.
Moreover, when the inorganic filler further contains silica particles, it is preferable to use silica particles having an average particle size of 1 μm or less in combination from the viewpoint of fluidity. For example, it is preferable to use a combination of silica particles having an average particle size of 0.1 μm to 1 μm, more preferably to use a combination of silica particles having an average particle size of 0.2 μm to 1 μm, and an average particle size of 0.3 μm. More preferably, silica particles of ~1 μm are used in combination.
Whether the epoxy resin composition contains the inorganic fillers combined as described above can be confirmed, for example, by determining the volume-based particle size distribution (frequency distribution) of the inorganic fillers.

When alumina particles having an average particle size of 1 μm or more and alumina particles having an average particle size of less than 1 μm are used in combination, the mixing ratio is not particularly limited. For example, the ratio of alumina particles having an average particle diameter of 1 μm or less is preferably blended so that it is 5% by mass to 20% by mass with respect to the total amount of alumina particles, and is blended so that it is 10% by mass to 15% by mass. is more preferable.

From the viewpoint of fluidity of the epoxy resin composition, the particle shape of the inorganic filler is preferably spherical, and the particle size distribution of the inorganic filler is preferably distributed over a wide range. For example, it is preferable that 70% by mass or more of the inorganic filler be spherical particles, and that the particle diameter of the spherical particles be distributed over a wide range of 0.1 μm to 80 μm. Such inorganic fillers tend to form a close-packed structure when particles of different sizes are mixed, so even if the content of the inorganic filler is increased, the increase in viscosity of the epoxy resin composition can be suppressed. There is a tendency to obtain an epoxy resin composition having excellent fluidity.

The content of the inorganic filler is 75% to 84% by volume with respect to the total volume of the composition, and from the viewpoint of the balance of properties such as thermal conductivity and fluidity, it should be 76% to 84% by volume. is preferred, and 77% by volume to 83% by volume is more preferred.
In addition, the content of the inorganic filler is preferably 90% by mass to 96% by mass, based on the total mass of the composition, from the viewpoint of the balance of properties such as thermal conductivity and fluidity, and 91% by mass to It is more preferably 95% by mass, and even more preferably 92% to 94% by mass.

The inorganic filler contains alumina particles and does not contain silica particles, or contains alumina particles and further contains silica particles in an amount of more than 0% by mass and 15% by mass or less with respect to the total amount of alumina particles and silica particles. From the viewpoint of thermal conductivity and fluidity, the inorganic filler contains alumina particles and does not contain silica particles, or contains alumina particles and silica particles, with respect to the total amount of alumina particles and silica particles. % or less is preferable. For example, the inorganic filler may contain alumina particles but not silica particles, or may contain alumina particles and silica particles in an amount of more than 0% by mass and not more than 5% by mass with respect to the total amount of alumina particles and silica particles. In addition, the inorganic filler may contain alumina particles and may further contain silica particles in an amount of 5% by mass to 10% by mass with respect to the total amount of alumina particles and silica particles. Fluidity tends to improve when silica particles are used in combination with alumina particles. Although the reason for this is not clear, it is presumed that the contact area between alumina particles is reduced and the friction between alumina particles is reduced.

Inorganic fillers other than alumina particles and silica particles are not particularly limited, and include glass, calcium carbonate, zirconium silicate, magnesium oxide, calcium silicate, silicon nitride, aluminum nitride, boron nitride, silicon carbide, industrial diamond, Particles of inorganic substances such as beryllia, zirconia, zircon, forsterite, steatite, spinel, mullite, titania, talc, clay, mica, etc., and beads obtained by making these particles spherical. In addition, an inorganic filler having a flame retardant effect may be used. Inorganic fillers having a flame retardant effect include particles of aluminum hydroxide, magnesium hydroxide, composite metal hydroxides such as composite hydroxides of magnesium and zinc, and zinc borate. Inorganic fillers other than alumina particles and silica particles may be used singly or in combination of two or more.

The content of inorganic fillers other than alumina particles and silica particles with respect to the total volume of the inorganic filler is preferably 20% by volume or less, more preferably 10% by volume or less, and 5% by volume or less. is more preferable, and 2% by volume or less is particularly preferable.

The porosity of the inorganic filler is not particularly limited, and is preferably 18% by volume or less, more preferably 16% by volume or less, even more preferably 15% by volume or less, and 14% by volume or less. is particularly preferred. The porosity of the inorganic filler may be 7% by volume or more. When there is one type of inorganic filler, the porosity of the inorganic filler means the porosity of one type of inorganic filler, and when there are two or more types of inorganic filler, the porosity of the inorganic filler means the porosity for a mixture of two or more inorganic fillers.

The porosity of the inorganic filler is a value representing the ratio of voids to the bulk volume of the inorganic filler ((void/bulk volume of inorganic filler)×100(%)). If the weight of the inorganic filler is the same, the smaller the porosity, the smaller the bulk volume of the inorganic filler. When the bulk volume of the inorganic filler contained in the epoxy resin composition becomes small, even if the content of the inorganic filler contained in the epoxy resin composition is the same, the bulk volume of the inorganic filler is less than the volume of the epoxy resin composition. The value obtained by subtracting is larger. Hereinafter, this value may be referred to as "amount of surplus resin". When the porosity of the inorganic filler decreases (that is, the amount of excess resin increases), the curability, fluidity, and moldability of the epoxy resin composition and the thermal conductivity of the cured product tend to improve. be. Although the reason for this is not clear, it is believed that the increase in the amount of excess resin reduces the viscosity of the epoxy resin composition and improves the fluidity. In addition, it is presumed that the increase in the amount of the surplus resin improves the dispersibility of the epoxy resin composition during kneading, thereby improving the curability, the moldability, and the thermal conductivity of the cured product.

The porosity of the inorganic filler refers to the value measured by the following method.
The epoxy resin composition is placed in a crucible and left at 800° C. for 4 hours to be incinerated. The particle size distribution of the resulting ash is measured using a laser diffraction particle size distribution analyzer (eg, LA920, Horiba, Ltd.) applying the refractive index of alumina. The porosity ε is calculated from the particle size distribution using the following Ouchiyama formula. The Ouchiyama formula is detailed in the following document.
N. Ouchiyama and T. Tanaka, Ind. Eng. Chem. Fundament. , 19, 338 (1980)
N. Ouchiyama and T. Tanaka, Ind. Eng. Chem. Fundament. , 20, 66 (1981)
N. Ouchiyama and T. Tanaka, Ind. Eng. Chem. Fundament. , 23, 490 (1984)

The particle size distribution of the inorganic filler is not particularly limited. For example, in the volume-based particle size distribution of the inorganic filler, the proportion of particles with a particle diameter of 1 μm or less is 9 vol% or more, and the proportion of particles with a particle diameter of more than 1 μm and 10 μm or less is 45 vol% or less, It is preferable that the proportion of particles having a particle diameter of more than 10 μm and 30 μm or less is 20% by volume or more, and the proportion of particles having a diameter of more than 30 μm is 18% by volume or more. When the inorganic filler having such a specific particle size distribution is contained, curability, fluidity and moldability tend to be excellent, and thermal conductivity of the cured product tends to be excellent.
In the volume-based particle size distribution of the inorganic filler, the proportion of particles with a particle diameter of 1 μm or less is 11% by volume or more, and the proportion of particles with a particle diameter of more than 1 μm and 10 μm or less is 40% by volume or less, and the particle diameter More preferably, the proportion of particles with a diameter of more than 10 μm and 30 μm or less is 22% by volume or more, and the proportion of particles with a diameter of more than 30 μm is 20% by volume or more.
In the volume-based particle size distribution of the inorganic filler, the proportion of particles with a particle diameter of 1 μm or less is 12% by volume or more, and the proportion of particles with a particle diameter of more than 1 μm and 10 μm or less is 30% by volume or less, and the particle diameter More preferably, the proportion of particles having a diameter of more than 10 μm and less than or equal to 30 μm is 24% by volume or more, and the proportion of particles having a diameter of more than 30 μm is 30% by volume or more.
In the volume-based particle size distribution of the inorganic filler, the proportion of particles with a particle diameter of 1 μm or less is 20% by volume or less, and the proportion of particles with a particle diameter of more than 1 μm and 10 μm or less is 15% by volume or more, and the particle diameter The proportion of particles having a diameter of more than 10 μm and 30 μm or less may be 35% by volume or less, and the proportion of particles having a diameter of more than 30 μm may be 45% by volume or less.

The volume-based particle size distribution of the inorganic filler can be measured by the following method.
The inorganic filler to be measured is added to the solvent (pure water) in the range of 1% to 5% by mass together with a surfactant of 1% to 8% by mass. Vibrate for a minute to disperse the inorganic filler. About 3 mL of the dispersion liquid is injected into the measurement cell and measured at 25°C. A laser diffraction particle size distribution meter (for example, LA920, manufactured by Horiba, Ltd.) is used as a measurement device to measure the volume-based particle size distribution. The average particle diameter is obtained as the particle diameter (D50%) when the accumulation from the small diameter side is 50% in the volume-based particle size distribution. As the refractive index, the refractive index of alumina particles is used. When the inorganic filler is a mixture of alumina particles and other inorganic fillers, the refractive index of the alumina particles shall be used.

A method for adjusting the particle size distribution of the inorganic filler is not particularly limited. For example, a small particle size inorganic filler with an average particle size of about 0.5 μm, a medium particle size inorganic filler with an average particle size of about 2 μm, and a large particle size inorganic filler with an average particle size of about 45 μm. may be appropriately combined to prepare an inorganic filler exhibiting the volume-based particle size distribution exemplified above.

[Plasticizer]
The epoxy resin composition contains a plasticizer. When the epoxy resin composition contains a plasticizer, even if the inorganic filler containing alumina particles is highly filled, it tends to be possible to suppress the occurrence of wire sweep and the like. The reason for this is presumed to be a decrease in high-temperature elastic modulus and an improvement in fluidity. Examples of plasticizers include triphenylphosphine oxide, organic phosphorus compounds such as phosphoric acid esters, silicones, modified compounds thereof, and the like. An indene-styrene copolymer is also preferably used as a plasticizer. Among them, the plasticizer preferably contains an organic phosphorus compound, and more preferably contains triphenylphosphine oxide. The content of the plasticizer is preferably 0.001% by mass to 30% by mass, more preferably 5% by mass to 20% by mass, and 5% by mass to 15% by mass with respect to the epoxy resin. is more preferred. A plasticizer may be used individually by 1 type, or may be used in combination of 2 or more types.

[Curing accelerator]
The epoxy resin composition of the present disclosure may optionally contain a curing accelerator. As the curing accelerator, those commonly used in epoxy resin compositions for sealing can be appropriately selected and used. Curing accelerators include, for example, organophosphorus compounds, imidazole compounds, tertiary amines, and quaternary ammonium salts. Among them, organic phosphorus compounds are preferred. A hardening accelerator may be used individually by 1 type, or may be used in combination of 2 or more type.

Examples of organic phosphorus compounds include organic phosphines such as tributylphosphine, phenylphosphine, diphenylphosphine, triphenylphosphine, methyldiphenylphosphine and triparatolylphosphine, and these phosphines with maleic anhydride, benzoquinone, diazophenylmethane and the like. Phosphorus compounds with intramolecular polarization (e.g. adducts of triphenylphosphine and benzoquinone and tri-para-tolylphosphine and benzoquinone); tetraphenylphosphonium tetraphenylborate, triphenylphosphine tetra phenylborate, 2-ethyl-4-methylimidazole tetraphenylborate, triphenylphosphonium-triphenylborane and the like. When an organophosphorus compound is used as a curing accelerator, there is a tendency to obtain high reliability in an electronic component device encapsulated with an epoxy resin composition. Although the reason for this is not clear, it can be considered as follows. In general, when an epoxy resin composition contains alumina particles, curability decreases, so there is a tendency to increase the amount of curing accelerator used. However, when the amount of the curing accelerator is increased, the amount of chloride ions generated by the reaction between the curing accelerator and chlorine derived from epichlorohydrin, which is the raw material of the epoxy resin, increases, which reduces the reliability of the electronic component device. Sometimes. On the other hand, organic phosphorus compounds are not too reactive, so using an organic phosphorus compound as a curing accelerator suppresses the reaction with chlorine, which suppresses the generation of chlorine ions and reduces reliability. It is considered possible.

When the epoxy resin composition contains a curing accelerator, the content of the curing accelerator is not particularly limited. It is preferably from 1.5% by mass to 7% by mass, and even more preferably from 1.8% by mass to 6% by mass.

[Organic solvent]
The epoxy resin composition of the present disclosure may contain an organic solvent. When the epoxy resin composition contains an organic solvent, the viscosity of the composition tends to decrease, and kneadability and fluidity tend to improve. The organic solvent is not particularly limited, and may contain, for example, an organic solvent having a boiling point of 50° C. to 100° C. (hereinafter also referred to as a specific organic solvent).

The specific organic solvent is not particularly limited, and for example, one having a boiling point of 50° C. to 100° C. and preferably non-reactive with the components in the epoxy resin composition can be appropriately selected and used. Specific organic solvents include alcohol-based solvents, ether-based solvents, ketone-based solvents, ester-based solvents, and the like. Among them, alcohol solvents are preferred, and methanol (boiling point 64.7°C), ethanol (boiling point 78.37°C), propanol (boiling point 97°C) and isopropanol (boiling point 82.6°C) are more preferred. A specific organic solvent may be used individually by 1 type, or may be used in combination of 2 or more types. The specific organic solvent may be added when preparing the epoxy resin composition, or may be generated by reaction during the kneading process when preparing the epoxy resin composition. In addition, in this disclosure, the boiling point of the specific organic solvent refers to the boiling point of the specific organic solvent measured at normal pressure.

The content of the specific organic solvent in the epoxy resin composition is not particularly limited. The content of the specific organic solvent is, for example, preferably 0.1% by mass to 10% by mass with respect to the total mass of the epoxy resin composition, and from the viewpoint of further improving thermal conductivity, it is 0.3% by mass. It is more preferably up to 4.0% by mass, still more preferably 0.3% by mass to 3.0% by mass, and particularly preferably 0.3% by mass to 2.5% by mass. When the content of the specific organic solvent is 0.3% by mass or more, the fluidity-improving effect tends to increase. When the content of the specific organic solvent is 3.0% by mass or less, the generation of voids is further suppressed when the epoxy resin in the epoxy resin composition is cured, and the deterioration of insulation reliability tends to be further suppressed. be.

The content of the alcohol solvent in the specific organic solvent is not particularly limited. The alcohol-based solvent content is, for example, preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more, relative to the total mass of the specific organic solvent. , 95% by mass or more. In addition, the epoxy resin composition may not substantially contain specific organic solvents other than alcohol-based solvents.

[Additive]
The epoxy resin composition may contain additives such as anion exchangers, mold release agents, flame retardants, coupling agents, stress relaxation agents, and colorants, if necessary.

(anion exchanger)
The epoxy resin composition may contain an anion exchanger if necessary. In particular, when the epoxy resin composition is used as the encapsulating material, it preferably contains an anion exchanger from the viewpoint of improving the moisture resistance and high-temperature storage characteristics of the electronic component device including the element to be encapsulated.

The anion exchanger is not particularly limited, and can be selected from those conventionally commonly used in the technical field. Examples include hydrotalcite compounds and hydrous oxides of elements selected from magnesium, aluminum, titanium, zirconium and bismuth.

The anion exchanger is not particularly limited, and can be selected from those conventionally commonly used in the technical field. Examples of anion exchangers include hydrotalcite compounds having compositions represented by the following formula (I), and hydrous oxides of elements selected from the group consisting of magnesium, aluminum, titanium, zirconium, bismuth and antimony. . The anion exchangers may be used singly or in combination of two or more.
Mg _1−x Al _x (OH) ₂ (CO ₃ ) _x/2 ·mH ₂ O (I)
(0<X≤0.5, m is a positive number)

Hydrotalcite compounds capture anions such as halogen ions by substituting CO ₃ in the structure, and the halogen ions incorporated in the crystal structure are desorbed at temperatures above about 350°C until the crystal structure is destroyed. It is a compound with no properties. Examples of hydrotalcite having such properties include Mg ₆ Al ₂ (OH) ₁₆ CO ₃ .4H ₂ O produced as a natural product, and Mg _4.3 Al ₂ (OH) _12.6 CO ₃ produced as a synthetic product. - _mH2O etc. are mentioned.

When the epoxy resin composition contains a phenolic curing agent as a curing agent, the epoxy resin composition exhibits acidity under the influence of the phenolic curing agent (for example, an extract of the cured product using pure water has a pH of 3 to 5). . In this case, for example, aluminum, which is an amphoteric metal, becomes an environment that is easily corroded by the epoxy resin composition. tend to be suppressed.

In addition, hydrous oxides of at least one element selected from the group consisting of magnesium, aluminum, titanium, zirconium, bismuth and antimony can also be captured by replacing anions such as halogen ions with hydroxide ions. can. Furthermore, these ion exchangers exhibit excellent ion exchange capacity on the acidic side. Therefore, when the epoxy resin composition contains these ion exchangers, corrosion of aluminum tends to be suppressed, as in the case of containing a hydrotalcite compound. Examples of hydrous oxides include MgO.nH ₂ O, Al ₂ O _{3.nH 2} O, ZrO _{2.H 2} O, Bi ₂ O _{3.H 2} O, Sb ₂ O _{5.nH 2} O and the like.

When the epoxy resin composition contains an anion exchanger, the content of the anion exchanger is not particularly limited as long as it is sufficient to capture anions such as halogen ions. When the epoxy resin composition contains an anion exchanger, the content of the anion exchanger is, for example, preferably 0.1% by mass to 30% by mass, and 1.0% by mass to 5% by mass. It is more preferable to have

(Release agent)
The epoxy resin composition may contain a mold release agent as necessary from the viewpoint of exhibiting good mold releasability in the molding process. The type of release agent is not particularly limited, and includes release agents known in the art. Specific examples of release agents 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. mentioned. Among them, carnauba wax and polyolefin wax are preferred. The release agent may be used alone or in combination of two or more.

As the polyolefin wax, a commercially available product may be used, and examples thereof include low molecular weight polyethylene having a number average molecular weight of about 500 to 10,000, such as H4, PE, and PED series manufactured by Hoechst.

When the epoxy resin composition contains a polyolefin wax, the content of the polyolefin wax is preferably 0.01% by mass to 10% by mass, more preferably 0.10% by mass to 5% by mass, relative to the epoxy resin. is more preferable. When the polyolefin wax content is 0.01% by mass or more, sufficient releasability tends to be obtained, and when it is 10% by mass or less, sufficient adhesiveness tends to be obtained.
In addition, when the epoxy resin composition contains a release agent other than polyolefin wax, or when the epoxy resin composition contains polyolefin wax and other release agent, release agent other than polyolefin wax may be used. The content of the mold agent is preferably 0.1% by mass to 10% by mass, more preferably 0.5% by mass to 3% by mass, relative to the epoxy resin.

(Flame retardants)
The epoxy resin composition may contain a flame retardant as necessary from the viewpoint of imparting flame retardancy. Flame retardants are not particularly limited, and include, for example, known organic and inorganic compounds containing halogen atoms, antimony atoms, nitrogen atoms or phosphorus atoms, metal hydroxides, and acenaphthylene. A flame retardant may be used individually by 1 type, or may be used in combination of 2 or more type.

When the epoxy resin composition contains a flame retardant, the content of the flame retardant is not particularly limited as long as the flame retardant effect is obtained. When the epoxy resin composition contains a flame retardant, the content of the flame retardant is preferably 1% by mass to 30% by mass, more preferably 2% by mass to 15% by mass, relative to the epoxy resin. preferable.

(coupling agent)
The epoxy resin composition may contain a coupling agent, if necessary, from the viewpoint of enhancing the adhesion between the resin component and the inorganic filler. The type of coupling agent is not particularly limited. Coupling agents include various silane compounds such as epoxysilane, mercaptosilane, aminosilane, alkylsilane, ureidosilane, methacrylsilane, acrylicsilane, and vinylsilane, titanium compounds, aluminum chelate compounds, aluminum and zirconium-containing compounds, and the like. A coupling agent may be used individually by 1 type, or may be used in combination of 2 or more type.

When the epoxy resin composition contains a coupling agent, the content of the coupling agent is preferably 0.05% by mass to 5.0% by mass, more preferably 0.10% by mass to 5.0% by mass, relative to the inorganic filler. More preferably, it is 2.5% by mass. When the content of the coupling agent is 0.05% by mass or more, the adhesion to the frame tends to be improved, and when it is 5.0% by mass or less, the moldability of the package tends to be excellent.

(Stress relaxation agent)
From the viewpoint of reducing the amount of package warpage deformation and package cracks, the epoxy resin composition may optionally contain a stress relaxation agent such as silicone oil or silicone rubber particles. As the stress relaxation agent that can be used, a flexible agent (stress relaxation agent) generally used in the art can be appropriately selected and used.

Specific examples of stress relaxation agents include thermoplastic elastomers such as silicone, polystyrene, polyolefin, polyurethane, polyester, polyether, polyamide, and polybutadiene; NR (natural rubber), NBR (acrylonitrile-butadiene rubber), acrylic rubber, urethane rubber , rubber particles such as silicone powder; rubbers having a core-shell structure such as methyl methacrylate-styrene-butadiene copolymer (MBS), methyl methacrylate-silicone copolymer, methyl methacrylate-butyl acrylate copolymer particles and the like. Among them, a silicone-based stress relaxation agent containing silicone is preferable. Examples of silicone-based stress relieving agents include those having epoxy groups, those having amino groups, and those modified with polyethers. A stress relaxation agent may be used individually by 1 type, or may be used in combination of 2 or more types.

(coloring agent)
The epoxy resin composition may contain coloring agents such as carbon black, fibrous carbon, organic dyes, organic coloring agents, titanium oxide, red lead, and red iron oxide. When the epoxy resin composition contains a coloring agent, the content of the coloring agent is preferably 0.05% by mass to 5.0% by mass, more preferably 0.10% by mass to 2.0% by mass, relative to the inorganic filler. More preferably, it is 5% by mass.

[Method for preparing epoxy resin composition]
Any method may be used for the preparation of the epoxy resin composition as long as the various components can be dispersed and mixed. As a general method, after thoroughly mixing various components with a mixer or the like, the mixture is melted and kneaded with a mixing roll, an extruder or the like, cooled and pulverized. More specifically, the epoxy resin composition is prepared by, for example, mixing and stirring the above components, kneading the mixture with a kneader, roll, extruder, or the like preheated to 70° C. to 140° C., and then cooling. It can be obtained by a method such as pulverization. The epoxy resin composition may be tableted to a size and mass to meet the molding requirements of the package. Tableting the epoxy resin composition facilitates handling.

[Fluidity of Epoxy Resin Composition]
The epoxy resin composition of the present disclosure preferably exhibits a flow distance of 100 cm or more when the fluidity is measured by the following method. An epoxy resin composition is molded using a mold for spiral flow measurement conforming to EMMI-1-66, and the flow distance (cm) of the molding of the epoxy resin composition is measured. Molding of the epoxy resin composition is performed using a transfer molding machine under conditions of a mold temperature of 180° C., a molding pressure of 6.9 MPa, and a curing time of 120 seconds.

<Epoxy resin cured product>
The epoxy resin cured product of the present disclosure is obtained by curing the epoxy resin composition described above. The epoxy resin cured product of the present disclosure is obtained by curing the epoxy resin composition described above, and thus tends to be excellent in thermal conductivity.

[Thermal conductivity of cured epoxy resin]
The thermal conductivity of the cured epoxy resin is not particularly limited, and is preferably 4 W/(m·K) or more. In the present disclosure, the thermal conductivity of the cured epoxy resin is a value measured as follows. Using the epoxy resin composition, transfer molding is performed under conditions of a mold temperature of 180° C., a molding pressure of 7 MPa, and a curing time of 300 seconds to obtain a mold-shaped epoxy resin cured product. The specific gravity of the cured epoxy resin obtained is measured by the Archimedes method, and the specific heat is measured by DSC (for example, Perkin Elmer, DSC Pyris1). Also, the thermal diffusivity of the obtained cured product is measured by a laser flash method using a thermal diffusivity measuring device (for example, NETZSCH LFA467). Using the obtained specific gravity, specific heat, and thermal diffusivity, the thermal conductivity of the cured epoxy resin is calculated.

<Electronic parts equipment>
An electronic component device of the present disclosure has an element and a cured product of the epoxy resin composition of the present disclosure sealing the element, and has the form of a BGA package. A BGA package is manufactured by mounting an element on the front surface of a substrate with metal bumps formed on the back surface, connecting the element and wiring formed on the substrate by bumps or wire bonding, and then sealing the element. . Examples of substrates include glass-epoxy substrates and printed wiring boards. An active element, a passive element, etc. are mentioned as an element. Active elements include semiconductor chips, transistors, diodes, thyristors, and the like. Passive elements include capacitors, resistors, coils, and the like.

In the electronic component device of the present disclosure, the method of sealing the element with the cured epoxy resin is not particularly limited, and any method known in the art can be applied. For example, a low-pressure transfer molding method is generally used, but an injection molding method, a compression molding method, or the like may also be used.

An example of the above-described embodiment will be specifically described below with reference to examples, but the present invention is not limited to these examples.

(Preparation of epoxy resin composition)
The components shown below were mixed in the proportions shown in Table 1 to prepare epoxy resin compositions of Examples and Comparative Examples. In Table 1, unless otherwise specified, the amounts of the components are expressed in parts by mass, and "-" indicates that the component is not included.

・ Epoxy resin 1 ... biphenyl type epoxy resin (Mitsubishi Chemical Corporation, trade name "YX-4000")
・ Epoxy resin 2 ... bisphenol F type epoxy resin (Nippon Steel & Sumikin Chemical Co., Ltd., trade name "YSLV-80XY")
Curing agent: polyfunctional phenolic resin (Air Water Inc., trade name “HE910”, triphenylmethane type phenolic resin with a hydroxyl equivalent of 105 g/eq)
・Curing accelerator: Phosphorus-based curing accelerator (organic phosphorus compound)

The following was prepared as an inorganic filler.
・ Inorganic filler 1: alumina-silica mixed filler (silica content: 10% by mass), volume average particle size: 10 μm
・ Inorganic filler 2: alumina filler, volume average particle size: 10 μm
・ Inorganic filler 3: alumina filler, volume average particle size: 0.8 μm
・ Inorganic filler 4: silica filler, volume average particle size: 0.8 μm

The following was prepared as a plasticizer.
・Plasticizer 1: Organic phosphine oxide ・Plasticizer 2: Indene-styrene copolymer (Nikuri Chemical Co., Ltd., NH-100S)

In addition, the following were prepared as various additives.
Coupling agent: Anilinosilane (N-phenyl-3-aminopropyltrimethoxysilane, Shin-Etsu Chemical Co., Ltd., trade name: KBM-573)
・ Coloring agent: carbon black (Mitsubishi Chemical Co., Ltd., product name: MA-100)
・Releasing agent: Montan acid ester (Celarica NODA Co., Ltd.)

(Evaluation of liquidity)
Fluidity evaluation of the epoxy resin composition was performed by a spiral flow test.
Specifically, an epoxy resin composition was molded using a spiral flow measurement mold conforming to EMMI-1-66, and the flow distance (cm) of the molded epoxy resin composition was measured. Molding of the epoxy resin composition was performed using a transfer molding machine under conditions of a mold temperature of 180° C., a molding pressure of 6.9 MPa, and a curing time of 120 seconds. In addition, the fluidity was rated A when it was 100 cm or more, and B when it was less than 100 cm.

(Evaluation of thermal conductivity)
Evaluation of thermal conductivity when the epoxy resin composition was cured was performed as follows. Specifically, using the prepared epoxy resin composition, transfer molding was performed under conditions of a mold temperature of 180° C., a molding pressure of 7 MPa, and a curing time of 300 seconds to obtain a cured product in the shape of a mold. The specific gravity of the obtained cured product measured by the Archimedes method was 3.00 to 3.40. The specific heat of the obtained cured product was measured by DSC (Perkin Elmer, DSC Pyris1). The thermal diffusivity of the cured product was measured by the laser flash method using a thermal diffusivity measuring device (LFA467, NETZSCH). Using the obtained specific gravity, specific heat, and thermal diffusivity, the thermal conductivity of the cured epoxy resin was calculated. A thermal conductivity of 4 W/(m·K) or more was rated A, and a thermal conductivity of less than 4 W/(m·K) was rated B.

When the content of the inorganic filler in the composition in Example 6 was changed to 85% by mass and kneading was carried out, no kneaded product was obtained.

As can be seen from Table 2, it contains epoxy resin 2, a curing agent, an inorganic filler, and a plasticizer, the content of the inorganic filler is 75% by volume to 84% by volume, and the total amount of alumina particles and silica particles In Examples 1 to 8, in which the proportion of silica particles is in the range of 0% by mass to 15% by mass or less, both fluidity and thermal conductivity were evaluated as good.

The disclosure of Japanese Patent Application No. 2017-254882 is incorporated herein by reference in its entirety.
All publications, patent applications and technical standards mentioned herein are to the same extent as if each individual publication, patent application and technical standard were specifically and individually noted to be incorporated by reference. incorporated herein by reference.

Claims (12)

an epoxy resin containing a bisphenol F type epoxy resin and a biphenyl type epoxy resin;
a curing agent;
an inorganic filler that contains alumina particles and does not contain silica particles, or that contains alumina particles and further contains silica particles in excess of 0% by mass and 15% by mass or less with respect to the total amount of alumina particles and silica particles;
a plasticizer;
contains
The content of the inorganic filler is 75% by volume to 84% by volume,
The content of the epoxy resin other than the bisphenol F type epoxy resin and the biphenyl type epoxy resin is 10% by mass or less with respect to the total amount of the epoxy resin.
An epoxy resin composition for encapsulating a ball grid array package. In claim 1 , wherein the inorganic filler contains alumina particles and does not contain silica particles, or contains alumina particles and further contains silica particles more than 0% by mass and 10% by mass or less with respect to the total amount of alumina particles and silica particles. An epoxy resin composition for encapsulating a ball grid array package as described. 3. The epoxy resin composition for encapsulating a ball grid array package according to claim 1 , wherein the curing agent contains a phenolic curing agent having a hydroxyl equivalent of 150 g/eq or less. The epoxy resin composition for encapsulating a ball grid array package according to any one of claims 1 to 3 , wherein the curing agent contains a phenolic resin having 3 or more phenolic hydroxyl groups in one molecule. 5. The epoxy resin composition for encapsulating a ball grid array package according to claim 1 , wherein the curing agent contains a triphenylmethane type phenolic resin. 6. The epoxy resin composition for encapsulating a ball grid array package according to claim 1 , wherein the inorganic filler has a porosity of 18% by volume or less. In the volume-based particle size distribution of the inorganic filler, the proportion of particles having a particle diameter of 1 μm or less is 9 vol% or more, and the proportion of particles having a particle diameter of more than 1 μm and 10 μm or less is 45 vol% or less, and the particles The proportion of particles with a diameter of more than 10 μm and 30 μm or less is 20% by volume or more, and the proportion of particles with a diameter of more than 30 μm is 18% by volume or more, according to any one of claims 1 to 6 . epoxy resin composition for ball grid array package sealing. In the volume-based particle size distribution of the inorganic filler, the proportion of particles with a particle diameter of 1 μm or less is 11 vol% or more, and the proportion of particles with a particle diameter of more than 1 μm and 10 μm or less is 40 vol% or less, and the particles 8. The epoxy resin for encapsulating a ball grid array package according to claim 7 , wherein the proportion of particles having a diameter of more than 10 μm and 30 μm or less is 22% by volume or more, and the proportion of particles having a diameter of more than 30 μm is 20% by volume or more. Composition. The ball grid array package sealing according to any one of claims 1 to 8, wherein the content of the bisphenol F type epoxy resin is 10% by mass to 75% by mass with respect to the total amount of the epoxy resin. epoxy resin composition for The ball grid array package sealing according to any one of claims 1 to 9, wherein the content of the biphenyl type epoxy resin is 20% by mass to 90% by mass with respect to the total amount of the epoxy resin. Epoxy resin composition. A cured epoxy resin obtained by curing the epoxy resin composition for encapsulating a ball grid array package according to any one of claims 1 to 10 . An electronic component device having an element and the epoxy resin cured product according to claim 11 sealing the element, and having the form of a ball grid array package.