JP2023085411A - Encapsulation composition and semiconductor device - Google Patents

Abstract

To provide an encapsulation composition that has excellent fluidity when alumina is used as an inorganic filler.SOLUTION: An encapsulation composition contains an epoxy resin, a curing agent, an inorganic filler containing alumina, and a tertiary phosphine oxide or alumina fluidizing agent.SELECTED DRAWING: None

Description

The present invention relates to encapsulation compositions and semiconductor devices.

2. Description of the Related Art In recent years, with the miniaturization and high integration of semiconductor packages, there is concern about heat generation inside the semiconductor packages. Heat generation may cause performance degradation of electrical or electronic components having a semiconductor package. Therefore, members used in semiconductor packages are required to have high thermal conductivity. For example, it is required to improve the thermal conductivity of sealing materials for semiconductor packages.
As one of the techniques for increasing the thermal conductivity of the encapsulant, there is a method of using silica and alumina, which is a highly thermally conductive inorganic filler, as the inorganic filler contained in the encapsulant (see, for example, Patent Document 1). ).

Japanese Patent No. 4188634

If alumina is used to increase the thermal conductivity of the sealing material, the fluidity may deteriorate. For example, in a semiconductor package employing a method called wire bonding structure in which a semiconductor element and a substrate are connected via wires, a semiconductor element, a substrate, and wires electrically connecting them are made of a resin composition. It is formed by sealing with a certain sealing material. At this time, pressure is applied to the wires due to the flow of the encapsulant, which may cause displacement of the wires (wire drift) and insufficient protection of the semiconductor element.

One aspect of the present invention has been made in view of the above-described conventional circumstances, and an object thereof is to provide a sealing composition having excellent fluidity when alumina is used as an inorganic filler, and a semiconductor device using the same. aim.

Specific means for achieving the above object are as follows.
<1> A sealing composition containing an epoxy resin, a curing agent, an inorganic filler containing alumina, and a tertiary phosphine oxide.
<2> The sealing composition according to <1>, wherein the tertiary phosphine oxide comprises a triarylphosphine oxide.
<3> The sealing composition according to <2>, wherein the triarylphosphine oxide comprises triphenylphosphine oxide.
<4> The sealing composition according to any one of <1> to <3>, wherein the content of the tertiary phosphine oxide is 25 parts by mass or less with respect to 100 parts by mass of the epoxy resin.
<5> The sealing composition according to any one of <1> to <4>, wherein the alumina content in the inorganic filler is 50% by volume or more.
<6> A sealing composition containing an epoxy resin, a curing agent, an inorganic filler containing alumina, and an alumina fluidizing agent.
<7> A semiconductor device comprising a semiconductor element and a cured product of the sealing composition according to any one of <1> to <6>, obtained by sealing the semiconductor element.

ADVANTAGE OF THE INVENTION According to one aspect of this invention, the sealing composition which is excellent in fluidity|liquidity at the time of using an alumina as an inorganic filler, and a semiconductor device using the same can be provided.

Modes for carrying out the encapsulating composition and semiconductor device of 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 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.

<Sealing composition>
A first encapsulating composition of the present disclosure contains an epoxy resin, a curing agent, an inorganic filler comprising alumina, and a tertiary phosphine oxide.
Also, the second encapsulating composition of the present disclosure contains an epoxy resin, a curing agent, an inorganic filler containing alumina, and an alumina fluidizing agent.
Hereinafter, the first sealing composition and the second sealing composition of the present disclosure may be collectively referred to as the sealing composition of the present disclosure.
The sealing composition of the present disclosure has excellent fluidity when alumina is used as the inorganic filler. Although the reason is not clear, it is presumed as follows.
Since the sealing composition of the present disclosure contains a tertiary phosphine oxide or alumina fluidizing agent, heating the sealing composition reduces the viscosity of the tertiary phosphine oxide or promotes fluidization of the alumina. , it is believed that the overall viscosity of the sealing composition is reduced. As a result, it is presumed that the fluidity of the sealing composition is improved even when alumina is used as the inorganic filler.
In conventional encapsulating compositions, if alumina is used as an inorganic filler to ensure high thermal conductivity, contradictory characteristics such as low fluidity of the encapsulating composition and high elastic modulus of the cured product occur. In some cases, it was difficult to achieve both properties of conductivity, low fluidity, and low elastic modulus of the cured product. According to the sealing composition of the present disclosure, the use of alumina as the inorganic filler ensures high thermal conductivity and enables low fluidity. Furthermore, even if alumina is used as the inorganic filler, the elastic modulus of the cured product can be lowered.

Each component constituting the sealing composition will be described below. The first encapsulating composition of the present disclosure contains an epoxy resin, a curing agent, an inorganic filler containing alumina, a tertiary phosphine oxide, and optionally other components. good. In addition, the second sealing composition of the present disclosure contains an epoxy resin, a curing agent, an inorganic filler containing alumina, an alumina fluidizing agent, and optionally other components. may

-Epoxy resin-
The encapsulating composition contains an epoxy resin. The type of epoxy resin is not particularly limited, and known epoxy resins can be used.
Specifically, for example, selected from the group consisting of phenolic compounds (e.g., phenol, cresol, xylenol, resorcinol, catechol, bisphenol A and bisphenol F) and naphthol compounds (e.g., α-naphthol, β-naphthol and dihydroxynaphthalene) and an aldehyde compound (e.g., formaldehyde, acetaldehyde, propionaldehyde, benzaldehyde and salicylaldehyde) under an acidic catalyst, and an epoxidized novolak resin obtained by condensation or co-condensation (e.g., phenol novolak-type epoxy resins and ortho-cresol novolak-type epoxy resins); one diglycidyl ether; epoxidized phenol-aralkyl resin; epoxidized adduct or polyadduct of a phenol compound and at least one selected from the group consisting of dicyclopentadiene and terpene compounds; polybasic acid ( Glycidyl ester type epoxy resin obtained by reaction of epichlorohydrin with epichlorohydrin; glycidylamine type epoxy resin obtained by reaction of polyamine (e.g. diaminodiphenylmethane and isocyanuric acid) with epichlorohydrin; linear aliphatic epoxy resins obtained by oxidation with (eg, peracetic acid); and cycloaliphatic epoxy resins. One type of epoxy resin may be used alone, or two or more types may be used in combination.

From the viewpoint of preventing corrosion of aluminum wiring or copper wiring on elements such as integrated circuits (ICs), the epoxy resin preferably has a high purity and a low hydrolyzable chlorine content. From the viewpoint of improving the moisture resistance of the sealing composition, the amount of hydrolyzable chlorine is preferably 500 ppm or less on a mass basis.

Here, the amount of hydrolyzable chlorine was obtained by dissolving 1 g of a sample epoxy resin in 30 mL of dioxane, adding 5 mL of a 1 mol/L (1N)-KOH methanol solution, refluxing for 30 minutes, and performing potentiometric titration. value.

The content of the epoxy resin in the sealing composition is preferably 2% to 10% by mass, more preferably 3% to 8% by mass, and 4% to 6% by mass. is more preferred.
The content of the epoxy resin in the sealing composition excluding the inorganic filler is preferably 30% by mass to 60% by mass, more preferably 35% by mass to 55% by mass, and 40% by mass to 50% by mass. % by mass is more preferred.

-Curing agent-
The sealing composition contains a curing agent. The type of curing agent is not particularly limited, and known curing agents can be used.
Specifically, for example, selected from the group consisting of phenolic compounds (e.g., phenol, cresol, resorcinol, catechol, bisphenol A and bisphenol F) and naphthol compounds (e.g., α-naphthol, β-naphthol and dihydroxynaphthalene) Novolac resins obtained by condensation or co-condensation of at least one kind of aldehyde compound (e.g., formaldehyde, acetaldehyde, propionaldehyde, benzaldehyde and salicylaldehyde) under an acidic catalyst; phenol-aralkyl resins; and naphthol-aralkyl resins ; One type of curing agent may be used alone, or two or more types may be used in combination.

The curing agent is blended so that the equivalent of the functional group (for example, phenolic hydroxyl group in the case of novolak resin) of the curing agent is 0.5 to 1.5 equivalents with respect to 1 equivalent of the epoxy group of the epoxy resin. It is particularly preferred that the curing agent is blended in an amount of 0.7 to 1.2 equivalents.

-Inorganic filler-
The encapsulating composition contains inorganic fillers including alumina. When the sealing composition contains an inorganic filler, the hygroscopicity of the sealing composition tends to be reduced and the strength in the cured state tends to be improved.

An inorganic filler may be used individually by 1 type, or may use 2 or more types together.
Examples of the combined use of two or more inorganic fillers include the use of two or more inorganic fillers having different components, average particle sizes, shapes, and the like.
The shape of the inorganic filler is not particularly limited, and examples thereof include powdery, spherical, fibrous and the like. A spherical shape is preferable from the viewpoints of fluidity during molding of the sealing composition and mold wear resistance.

The inorganic filler only needs to contain alumina, and even if all of the inorganic filler is alumina, alumina and other inorganic fillers may be used in combination. The inclusion of alumina in the inorganic filler tends to improve the thermal conductivity of the sealing composition.
Other inorganic fillers that can be used with alumina include silica such as spherical silica and crystalline silica, zircon, magnesium oxide, calcium silicate, calcium carbonate, potassium titanate, silicon carbide, silicon nitride, boron nitride, beryllia, and zirconia. is mentioned. Furthermore, examples of inorganic fillers having a flame retardant effect include aluminum hydroxide and zinc borate.

When alumina and another inorganic filler are used together as the inorganic filler, it is preferable to use silica as the other inorganic filler from the viewpoint of its spherical shape.
When alumina and silica are used together as inorganic fillers, the content of alumina in the inorganic filler is preferably 50% by volume or more, more preferably 60% by volume or more, and more preferably 70% by volume or more. is more preferable. Also, the content of alumina in the inorganic filler may be 100% by volume or less, preferably 99% by volume or less.

The content of the inorganic filler is preferably 70% by volume or more, preferably 73% by volume, based on the entire sealing composition, from the viewpoints of hygroscopicity, reduction in linear expansion coefficient, improvement in strength, and resistance to soldering heat. It is more preferably 76% by volume or more, and more preferably 76% by volume or more. The content of the inorganic filler may be 85% by volume or less.

The average particle size (volume average particle size) of the inorganic filler is preferably 1 μm to 30 μm, more preferably 3 μm to 20 μm, even more preferably 5 μm to 15 μm. In the present disclosure, the average particle size of the inorganic filler is the average particle size of alumina when alumina is used alone as the inorganic filler, and the average particle size of alumina is used as the inorganic filler in combination with other inorganic fillers. If it is used, it refers to the average particle size of the inorganic filler as a whole.
The average particle size of the inorganic filler can be measured by the following method.

Add the inorganic filler to be measured to the solvent (pure water) within the range of 0.02% by mass to 0.08% by mass, vibrate with a 110W bath-type ultrasonic cleaner for 1 minute to 10 minutes, Disperse the filler. About 40 mL of the dispersion liquid is injected into the measurement cell and measured at 25°C. A laser diffraction/scattering particle size distribution analyzer (for example, LA920 (trade name), manufactured by Horiba, Ltd.) is used as the measuring apparatus 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. Note that the refractive index of alumina is used as the refractive index. When the inorganic filler is a mixture of alumina and other inorganic fillers, the refractive index of alumina shall be used as the refractive index.

-Tertiary phosphine oxide-
A first sealing composition of the present disclosure contains a tertiary phosphine oxide.
The tertiary phosphine oxide is not particularly limited, and aliphatic tertiary phosphine oxides, aromatic tertiary phosphine oxides, and the like can be used. A tertiary phosphine oxide may be used individually by 1 type, or may use 2 or more types together.

Specific examples of tertiary phosphine oxides include triphenylphosphine oxide, diphenyl(p-tolyl)phosphine oxide, tris(alkylphenyl)phosphine oxide, tris(alkoxyphenyl)phosphine oxide, tris(alkylalkoxyphenyl)phosphine oxide, tris(alkylalkoxyphenyl)phosphine oxide, (dialkylphenyl)phosphine oxide, tris(trialkylphenyl)phosphine oxide, tris(tetraalkylphenyl)phosphine oxide, tris(dialkoxyphenyl)phosphine oxide, tris(trialkoxyphenyl)phosphine oxide, tris(tetraalkoxyphenyl)phosphine oxides such as triarylphosphine oxides, trialkylphosphine oxides, dialkylarylphosphine oxides, alkyldiarylphosphine oxides, and the like.

Among these, the tertiary phosphine oxide preferably contains triarylphosphine oxide. Also, the triarylphosphine oxide more preferably includes triphenylphosphine oxide.
The proportion of the triarylphosphine oxide in the tertiary phosphine oxide is preferably 30% by mass to 100% by mass, more preferably 50% by mass to 100% by mass, and 70% by mass to 100% by mass. is more preferred.
The proportion of triphenylphosphine oxide in triarylphosphine oxide is preferably 30% by mass to 100% by mass, more preferably 50% by mass to 100% by mass, and 70% by mass to 100% by mass. is more preferable.

The content of the tertiary phosphine oxide is preferably 25 parts by mass or less, more preferably 20 parts by mass or less, and even more preferably 15 parts by mass or less with respect to 100 parts by mass of the epoxy resin. The content of the tertiary phosphine oxide may be 1 part by mass or more with respect to 100 parts by mass of the epoxy resin.

- Alumina Fluidizer -
A second sealing composition of the present disclosure contains an alumina fluidizer.
In the present disclosure, alumina fluidizing agent refers to a compound that satisfies the following properties.
An epoxy resin, a curing agent, and alumina were mixed so that the content of alumina was 75% by volume to prepare a first sealing composition. (Shimadzu Corporation, CFT-100D (trade name)). Next, 5 parts by mass of a predetermined compound is added to 100 parts by mass of the first sealing composition to prepare a second sealing composition, and the viscosity of the second sealing composition at 175° C. is measured by a flow property evaluation device. (Shimadzu Corporation, CFT-100D (trade name)). Reduction rate of the viscosity of the second sealing composition with respect to the viscosity of the first sealing composition (((viscosity of the first sealing composition - viscosity of the second sealing composition) / viscosity of the first sealing composition )×100(%)) is 10% or more, the given compound is regarded as an alumina fluidizing agent.

As a result of intensive studies, the present inventors have found a method for evaluating a compound capable of improving fluidity of a sealing composition using alumina as an inorganic filler. By the above method, it is possible to easily find a compound (alumina fluidizing agent) that improves the fluidity of the sealing composition when alumina is used as the inorganic filler.

The melting temperature of the alumina fluidizing agent is not particularly limited, and from the viewpoint of becoming liquid at the sealing temperature when sealing the semiconductor package using the sealing composition, the melting temperature is not higher than the sealing temperature. It is preferably 165° C. or lower, more preferably 160° C. or lower.
From the viewpoint of the storage stability of the sealing composition, the alumina fluidizing agent preferably does not contain a functional group that accelerates the curing reaction of the epoxy resin. A carboxy group, an amino group, a hydroxyl group, etc. are mentioned as a functional group which accelerates|stimulates the hardening reaction of an epoxy resin.

The content of the alumina fluidizing agent is preferably 25 parts by mass or less, more preferably 20 parts by mass or less, and even more preferably 15 parts by mass or less with respect to 100 parts by mass of the epoxy resin. The content of the alumina fluidizing agent may be 1 part by mass or more with respect to 100 parts by mass of the epoxy resin.

(Curing accelerator)
The sealing composition may further contain a curing accelerator. The type of curing accelerator is not particularly limited, and known curing accelerators can be used.
Specifically, 1,8-diaza-bicyclo[5.4.0]undecene-7, 1,5-diaza-bicyclo[4.3.0]nonene, 5,6-dibutylamino-1,8- Cycloamidine compounds such as diaza-bicyclo[5.4.0]undecene-7; cycloamidine compounds such as maleic anhydride, 1,4-benzoquinone, 2,5-toluquinone, 1,4-naphthoquinone, and 2,3-dimethyl quinone compounds such as benzoquinone, 2,6-dimethylbenzoquinone, 2,3-dimethoxy-5-methyl-1,4-benzoquinone, 2,3-dimethoxy-1,4-benzoquinone, phenyl-1,4-benzoquinone; Compounds having intramolecular polarization obtained by adding compounds having π bonds such as phenylmethane and phenolic resins; tertiary amine compounds such as benzyldimethylamine, triethanolamine, dimethylaminoethanol and tris(dimethylaminomethyl)phenol; Derivatives of tertiary amine compounds; imidazole compounds such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, derivatives of imidazole compounds; tributylphosphine, methyldiphenylphosphine, triphenylphosphine, tris(4- organic phosphine compounds such as methylphenyl)phosphine, diphenylphosphine, and phenylphosphine; intramolecular polarization obtained by adding a compound having a π bond such as maleic anhydride, the above quinone compound, diazophenylmethane, and phenolic resin to an organic phosphine compound; Phosphorus compounds having; Tetraphenylboron salts such as tetraphenylphosphonium tetraphenylborate, triphenylphosphine tetraphenylborate, 2-ethyl-4-methylimidazole tetraphenylborate, N-methylmorpholine tetraphenylborate, derivatives of tetraphenylboron salts adducts of phosphine compounds such as triphenylphosphonium-triphenylborane, N-methylmorpholine tetraphenylphosphonium-tetraphenylborate, and tetraphenylboron salts; A hardening accelerator may be used individually by 1 type, or may use 2 or more types together.

The content of the curing accelerator is preferably 0.1% by mass to 8% by mass with respect to the total amount of the epoxy resin and curing agent.

(Ion trap agent)
The sealing composition may further contain an ion trapping agent.
The ion trapping agent that can be used in the present disclosure is not particularly limited as long as it is an ion trapping agent that is commonly used in sealing materials used for manufacturing semiconductor devices. Examples of ion trapping agents include compounds represented by the following general formula (II-1) or the following general formula (II-2).

Mg _1-a Al _a (OH) ₂ (CO ₃ ) _a/2 ·uH ₂ O (II-1)
(In general formula (II-1), a is 0 < a ≤ 0.5, and u is a positive number.)
BiO _b (OH) _c (NO ₃ ) _d (II-2)
(In general formula (II-2), b is 0.9≦b≦1.1, c is 0.6≦c≦0.8, and d is 0.2≦d≦0.4.)

Ion trapping agents are commercially available. As a compound represented by general formula (II-1), for example, "DHT-4A" (Kyowa Chemical Industry Co., Ltd., trade name) is commercially available. As a compound represented by the general formula (II-2), for example, "IXE500" (trade name of Toagosei Co., Ltd.) is available as a commercial product.

In addition, ion trapping agents other than those described above include hydrated oxides of elements selected from magnesium, aluminum, titanium, zirconium, antimony, and the like.
An ion trap agent may be used individually by 1 type, or may use 2 or more types together.

When the encapsulating composition contains an ion trapping agent, the content of the ion trapping agent is preferably 1 part by mass or more with respect to 100 parts by mass of the epoxy resin from the viewpoint of achieving sufficient moisture resistance reliability. . From the viewpoint of sufficiently exhibiting the effects of other components, the content of the ion trapping agent is preferably 15 parts by mass or less with respect to 100 parts by mass of the epoxy resin.

The average particle size of the ion trapping agent is preferably 0.1 μm to 3.0 μm, and the maximum particle size is preferably 10 μm or less. The average particle size of the ion trapping agent can be measured in the same manner as the inorganic filler.

(coupling agent)
The sealing composition may further contain a coupling agent. The type of coupling agent is not particularly limited, and known coupling agents can be used. Coupling agents include, for example, silane coupling agents and titanium coupling agents. A coupling agent may be used individually by 1 type, or may use 2 or more types together.

Examples of silane coupling agents include vinyltrichlorosilane, vinyltriethoxysilane, vinyltris(β-methoxyethoxy)silane, γ-methacryloxypropyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane. , γ-glycidoxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-[bis(β-hydroxyethyl)]aminopropyltriethoxysilane, N -β-(aminoethyl)-γ-aminopropyltrimethoxysilane, γ-(β-aminoethyl)aminopropyldimethoxymethylsilane, N-(trimethoxysilylpropyl)ethylenediamine, N-(dimethoxymethylsilylisopropyl)ethylenediamine, methyltrimethoxysilane, methyltriethoxysilane, N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, hexamethyldisilane, γ-anilinopropyltrimethoxysilane Silanes (N-phenyl-3-aminopropyltrimethoxysilane), vinyltrimethoxysilane and γ-mercaptopropylmethyldimethoxysilane are included.

Titanium coupling agents include, for example, isopropyl triisostearoyl titanate, isopropyl tris(dioctylpyrophosphate) titanate, isopropyl tri(N-aminoethyl-aminoethyl) titanate, tetraoctylbis(ditridecylphosphite) titanate, tetra( 2,2-diallyloxymethyl-1-butyl)bis(ditridecylphosphite)titanate, bis(dioctylpyrophosphate)oxyacetate titanate, bis(dioctylpyrophosphate)ethylene titanate, isopropyltrioctanoyltitanate, isopropyldimethacryl iso Stearoyl titanate, isopropyl tridodecylbenzenesulfonyl titanate, isopropyl isostearoyl diacryl titanate, isopropyl tri(dioctylphosphate) titanate, isopropyltricumylphenyl titanate and tetraisopropyl bis(dioctylphosphite) titanate.

When the sealing composition contains a coupling agent, the content of the coupling agent is preferably 3% by mass or less with respect to the entire sealing composition. .1% by mass or more is preferable.

(Release agent)
The sealing composition may further contain a release agent. The type of release agent is not particularly limited, and known release agents can be used. Specific examples include higher fatty acids, higher fatty acid esters, carnauba wax, and polyethylene waxes. The release agent may be used alone or in combination of two or more.
When the encapsulating composition contains a release agent, the content of the release agent is preferably 10% by mass or less with respect to the total amount of the epoxy resin and the curing agent, from the viewpoint of exhibiting its effect. is preferably 0.5% by mass or more.

(Colorant and modifier)
The encapsulating composition may contain a colorant (eg, carbon black). The sealing composition may also contain modifiers such as silicones and silicone rubbers. The colorant and the modifier may be used singly or in combination of two or more.

When conductive particles such as carbon black are used as the colorant, the content of particles having a particle diameter of 10 μm or more is preferably 1 mass % or less.
When the encapsulating composition contains conductive particles, the content of the conductive particles is preferably 4% by mass or less with respect to the total amount of the epoxy resin and the curing agent.

<Method for preparing sealing composition>
A method for producing the sealing composition is not particularly limited, and a known method can be used. For example, it can be produced by sufficiently mixing a mixture of raw materials in a predetermined amount with a mixer or the like, kneading with a hot roll, an extruder or the like, and subjecting the mixture to cooling, pulverization, or the like. The state of the sealing composition is not particularly limited, and may be powder, solid, liquid, or the like.

<Semiconductor device>
A semiconductor device of the present disclosure includes a semiconductor element and a cured product of the sealing composition of the present disclosure obtained by sealing the semiconductor element.

A method for sealing a semiconductor element using a sealing composition is not particularly limited, and a known method can be applied. For example, a transfer molding method is generally used, but a compression molding method, an injection molding method, or the like may also be used.

The semiconductor device of the present disclosure is suitable as an IC, LSI (Large-Scale Integration), or the like.

Examples of the present invention will be described below, but the present invention is not limited thereto. Numerical values in the table mean "mass parts" unless otherwise specified.

(Examples 1 to 5 and Comparative Examples 1 to 3)
After pre-mixing (dry blending) the materials having the formulations shown in Tables 1 and 2, they were kneaded for about 15 minutes with a twin-screw roll (roll surface temperature: about 80°C), cooled and pulverized to obtain a powdery sealing composition. manufactured. In Tables 1 and 2, "-" indicates that the corresponding component is not included.

-Epoxy resin-
・ Epoxy resin 1: biphenyl type epoxy resin, epoxy equivalent: 192 g / eq
・ Epoxy resin 2: bisphenol type crystalline epoxy resin, epoxy equivalent: 192 g / eq
・ Epoxy resin 3: bisphenol F type epoxy resin, epoxy equivalent: 158 g / eq
-Curing agent-
・ Curing agent 1: polyfunctional phenolic resin, triphenylmethane type phenolic resin with a hydroxyl equivalent of 104 g / eq -curing accelerator-
・Phosphorus curing accelerator - coupling agent -
・ Coupling agent: N-phenyl-3-aminopropyltrimethoxysilane (silane coupling agent)
-Release agent-
・Montan acid ester -coloring agent-
・Carbon black - ion trapping agent -
・Hydrotalcite-based ion trapping agents -modifying agents-
・ Modifier 1: silicone (epoxy-modified silicone resin)
-Tertiary phosphine oxide-
・ Tertiary phosphine oxide: triphenylphosphine oxide - inorganic filler -
・ Alumina 1: Volume average particle size is 11.7 μm
・ Alumina 2: Volume average particle size is 13.5 μm
・ Alumina 3: Volume average particle size is 0.6 μm
・Silica 1: Volume average particle size is 21.7 μm
・Silica 2: Volume average particle size is 0.1 μm
・ Silica 3: Volume average particle size is 14.5 μm
・ Silica 4: Volume average particle size is 0.6 μm

<Evaluation of thermal conductivity>
Using the encapsulating composition obtained above, a compression molding machine is used to encapsulate a semiconductor element under the conditions of a mold temperature of 175° C. to 180° C., a molding pressure of 7 MPa, and a curing time of 150 seconds. A test piece was prepared. The thermal conductivity of the specimen was then measured by the Xenon flash (Xe-flash) method. Table 3 shows the results.

<Liquidity>
(Evaluation of spiral flow (SF))
Using a spiral flow measurement mold according to EMMI-1-66, the prepared sealing composition is molded with a transfer molding machine under the conditions of a mold temperature of 180 ° C., a molding pressure of 22.5 MPa, and a curing time of 300 seconds. to find the flow distance. Table 3 shows the results.
(Evaluation of disk flow (DF))
Using a flat plate mold for disk flow measurement having an upper mold of 200 mm (W) × 200 mm (D) × 25 mm (H) and a lower mold of 200 mm (W) × 200 mm (D) × 15 mm (H), 5 g of the sealing composition weighed with a pan balance was placed on the center of the lower mold heated to 180 ° C. After 5 seconds, the upper mold heated to 180 ° C. was closed, and the load was 78 N and the curing time was 90 seconds. The length (mm) and breadth (mm) of the molded product were measured with vernier calipers, and the average value (mm) was taken as the disc flow. Table 3 shows the results.

<High temperature elastic modulus>
The sealing composition was heated at 175° C. for 10 minutes to obtain a cured product measuring 10 mm×50 mm×3 mm. The elastic modulus of the resulting cured product was measured using a dynamic viscoelasticity measuring device ("RSAIII" available from TA instruments). The measurement was carried out from 30°C to 300°C at a heating rate of 10°C/min. Table 3 shows the elastic modulus (MPa) measured at 260° C. as the high temperature elastic modulus.

As is clear from the evaluation results in Table 3, the sealing compositions of Examples 1 to 5 containing alumina as an inorganic filler and a tertiary phosphine oxide contained alumina as an inorganic filler and a tertiary phosphine oxide. It can be seen that the fluidity is excellent compared to the sealing composition of Comparative Example 1 which does not contain. Also, it can be seen that the sealing compositions of Examples 1 to 5 are superior in thermal conductivity to the sealing compositions of Comparative Examples 2 and 3, which do not contain alumina as an inorganic filler.

The disclosure of Japanese Patent Application No. 2017-254884 filed on December 28, 2017 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 (7)

A sealing composition comprising an epoxy resin, a curing agent, an inorganic filler containing alumina, and a tertiary phosphine oxide. 2. The sealing composition of claim 1, wherein said tertiary phosphine oxide comprises a triarylphosphine oxide. 3. The sealing composition of claim 2, wherein said triarylphosphine oxide comprises triphenylphosphine oxide. The sealing composition according to any one of claims 1 to 3, wherein the content of the tertiary phosphine oxide is 25 parts by mass or less with respect to 100 parts by mass of the epoxy resin. The sealing composition according to any one of claims 1 to 4, wherein the alumina content of the inorganic filler is 50% by volume or more. A sealing composition comprising an epoxy resin, a curing agent, an inorganic filler containing alumina, and an alumina fluidizing agent. A semiconductor device comprising a semiconductor element and a cured product of the sealing composition according to any one of claims 1 to 6, which is obtained by sealing the semiconductor element.