JPWO2019131669A1 - Encapsulation composition and semiconductor device - Google Patents

Abstract

The sealing composition contains an epoxy resin, a curing agent, and an inorganic filler, and the particle size distribution of the inorganic filler has at least three peaks, and the inorganic filler has a particle size of 1 μm or less. Contains alumina.

Description

The present invention relates to a sealing composition and a semiconductor device.

In recent years, there is a concern about heat generation inside a semiconductor package due to miniaturization and high integration. High thermal conductivity is required for the members used in the semiconductor package because the heat generation may cause the performance of the electric component or the electronic component having the semiconductor package to deteriorate. Therefore, it is required to make the encapsulant of the semiconductor package highly thermally conductive.
As one of the methods for increasing the thermal conductivity of the encapsulant, there is a method of using alumina which is a high thermal conductive filler for the inorganic filler contained in the encapsulant (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2006-273920

However, the method described in Patent Document 1 may deteriorate the fluidity of the encapsulant. For example, in a semiconductor package that employs a method called a wire bonding structure in which a semiconductor element and a substrate are connected via wires, the semiconductor element, the substrate, and the wire that electrically connects them are made of a resin composition. It is formed by sealing. At that time, pressure is applied to the wire due to the flow of the sealing material, which may cause the wire to be displaced (wire flow) or the semiconductor element may not be sufficiently protected.
As described above, it may be difficult to achieve both the fluidity of the encapsulant and the high thermal conductivity.

One embodiment of the present invention has been made in view of the above-mentioned conventional circumstances, and an object of the present invention is to provide a sealing composition having excellent fluidity and high thermal conductivity, and a semiconductor device using the same.

Specific means for achieving the above-mentioned problems are as follows.
<1> Contains an epoxy resin, a curing agent, and an inorganic filler.
The particle size distribution of the inorganic filler has at least three peaks.
A sealing composition in which the inorganic filler contains alumina having a particle size of 1 μm or less.
<2> The sealing composition according to <1>, wherein the particle size distribution of the inorganic filler has peaks in the range of 0.3 μm to 0.7 μm, the range of 7 μm to 20 μm, and the range of 30 μm to 70 μm.
<3> The sealing composition according to <1> or <2>, wherein the proportion of alumina in the inorganic particles having a particle diameter of 1 μm or less contained in the inorganic filler is 1% by volume to 40% by volume.
<4> The sealing composition according to any one of <1> to <3>, wherein the average circularity of the inorganic filler is 0.80 or more.
<5> A semiconductor device including a semiconductor element and a cured product of the sealing composition according to any one of <1> to <4>, which is obtained by sealing the semiconductor element.

According to one embodiment of the present invention, it is possible to provide a sealing composition having excellent fluidity and high thermal conductivity, and a semiconductor device using the same.

Hereinafter, a mode for carrying out the sealing composition and the semiconductor device of the present invention will be described in detail. However, the present invention is not limited to the following embodiments. In the following embodiments, the components (including element steps and the like) are not essential unless otherwise specified. The same applies to the numerical values and their ranges, and does not limit the present invention.
The numerical range indicated by using "~" in the present disclosure includes the numerical values before and after "~" as the minimum value and the maximum value, respectively.
In the numerical range described stepwise in the present disclosure, the upper limit value or the lower limit value described in one numerical range may be replaced with the upper limit value or the lower limit value of another numerical range described stepwise. .. Further, in the numerical range described in the present disclosure, the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the examples.
In the present disclosure, each component may contain a plurality of applicable substances. When a plurality of substances corresponding to each component are present in the composition, the content rate or content of each component is the total content rate or content of the plurality of substances present in the composition unless otherwise specified. Means quantity.
In the present disclosure, a plurality of types of particles corresponding to each component may be contained. When a plurality 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 plurality of particles present in the composition unless otherwise specified.

<Encapsulation composition>
The sealing composition of the present disclosure contains an epoxy resin, a curing agent, and an inorganic filler, and the particle size distribution of the inorganic filler has at least three peaks, and the inorganic filler has a particle diameter. Contains alumina of 1 μm or less.
The sealing composition of the present disclosure has excellent fluidity and high thermal conductivity. The reason is not clear, but it can be inferred as follows.
The inorganic filler contained in the encapsulation composition exhibits a particle size distribution having at least three peaks. That is, the inorganic filler is composed of at least inorganic particles having a large particle diameter, inorganic particles having a medium particle diameter, and inorganic particles having a small particle diameter. Since the inorganic filler contains inorganic particles having a large particle diameter, inorganic particles having a medium particle diameter, and inorganic particles having a small particle diameter, the sealing composition of the present disclosure is considered to have excellent fluidity.
Further, where the inorganic filler contains alumina having a particle size of 1 μm or less, the alumina exhibits high thermal conductivity as described above. Alumina having a particle size of 1 μm or less corresponds to inorganic particles having a small particle size as the inorganic filler contained in the sealing composition. By containing alumina as the inorganic particles having a small particle size, alumina, which is an inorganic particle having a small particle size, is likely to be interposed between the inorganic particles having a large particle size and the inorganic particles having a medium particle size. Alumina showing high thermal conductivity intervenes between large particle size inorganic particles and medium particle size inorganic particles to promote heat conduction between large particle size inorganic particles and medium particle size inorganic particles. be able to. As a result, it is presumed that the sealing composition of the present disclosure has high thermal conductivity.

Hereinafter, each component constituting the sealing composition will be described. The sealing composition of the present disclosure contains an epoxy resin, a curing agent, and an inorganic filler, and may contain other components if necessary.

-Epoxy resin-
The sealing composition contains an epoxy resin. The type of epoxy resin is not particularly limited, and known epoxy resins can be used.
Specifically, for example, it is selected from the group consisting of phenol compounds (eg, phenol, cresol, xylenol, resorcin, catechol, bisphenol A and bisphenol F) and naphthol compounds (eg, α-naphthol, β-naphthol and dihydroxynaphthalene). Epoxy of novolak resin obtained by condensing or co-condensing at least one of the above and an aldehyde compound (for example, formaldehyde, acetaldehyde, propionaldehyde, benzaldehyde and salicylaldehyde) under an acidic catalyst (for example, phenol). Novolak type epoxy resin and orthocresol novolak type epoxy resin); at least selected from the group consisting of bisphenol (eg, bisphenol A, bisphenol AD, bisphenol F and bisphenol S) and biphenol (eg, alkyl-substituted and unsubstituted biphenol). One diglycidyl ether; an epoxie of a phenol-aralkyl resin; an epoxidate of an adduct or a heavy adduct of a phenol compound and at least one selected from the group consisting of dicyclopentadiene and terpen compounds; polybasic acid ( For example, a glycidyl ester type epoxy resin obtained by the reaction of phthalic acid and dimer acid) and epichlorohydrin; a glycidylamine type epoxy resin obtained by the reaction of polyamine (for example, diaminodiphenylmethane and isocyanuric acid) and epichlorohydrin; Examples include linear aliphatic epoxy resins obtained by oxidation with (for example, peracetic acid); and alicyclic 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 an element such as an integrated circuit (IC), the purity of the epoxy resin is preferably high, and the amount of hydrolyzable chlorine is preferably small. 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 is a value obtained by dissolving 1 g of the epoxy resin of the sample in 30 mL of dioxane, adding 5 mL of a 1N-KOH methanol solution, refluxing for 30 minutes, and then performing potentiometric titration.

The content of the epoxy resin in the sealing composition is preferably 1.5% by mass to 20% by mass, more preferably 2.0% by mass to 15% by mass, and 3.0% by mass to 30% by mass. It is more preferably 10% by mass.
The content of the epoxy resin in the sealing composition excluding the inorganic filler is preferably 30% by mass to 65% by mass, more preferably 35% by mass to 60% by mass, and 40% by mass to 55% by mass. It is more preferably by mass%.

-Hardener-
The sealing composition contains a curing agent. The type of curing agent is not particularly limited, and known curing agents can be used.
Specifically, it is selected from the group consisting of, for example, phenolic compounds (eg, phenol, cresol, resorcin, catechol, bisphenol A and bisphenol F) and naphthol compounds (eg, α-naphthol, β-naphthol and dihydroxynaphthalene). A novolak resin obtained by condensing or cocondensing at least one of an aldehyde compound (for example, formaldehyde, acetaldehyde, propionaldehyde, benzaldehyde and salicylaldehyde) under an acidic catalyst; phenol-aralkyl resin; biphenyl-aralkyl resin; In addition, naphthol-aralkyl resin; can be mentioned. One type of curing agent may be used alone, or two or more types may be used in combination. Among them, as the curing agent, a phenol / aralkyl resin is preferable from the viewpoint of improving reflow resistance. 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 of the curing agent (for example, phenolic hydroxyl group in the case of novolak resin) is 0.5 equivalent to 1.5 equivalent with respect to 1 equivalent of the epoxy group of the epoxy resin. It is preferable that the curing agent is blended so as to have an amount of 0.7 equivalent to 1.2 equivalent.

-Inorganic filler-
The sealing composition comprises an inorganic filler. By including the inorganic filler, the hygroscopicity of the sealing composition tends to be reduced, and the strength in the cured state tends to be improved.

As the inorganic filler, one type may be used alone, or two or more types may be used in combination.
Examples of the case where two or more kinds of inorganic fillers are used in combination include the case where two or more kinds of inorganic fillers having different components, average particle diameters, shapes and the like are used.
The shape of the inorganic filler is not particularly limited, and examples thereof include powder, spherical, and fibrous. From the viewpoint of fluidity during molding and mold wear resistance of the sealing composition, it is preferably spherical.

The average circularity of the inorganic filler is preferably 0.80 or more, more preferably 0.85 or more, further preferably 0.90 or more, and particularly preferably 0.93 or more. preferable. Further, the average circularity of the inorganic filler may be 1.0 or less.
The circularity of the inorganic filler is the circumference measured from the projected image of the inorganic filler as the circumference as a circle calculated from the diameter equivalent to a circle, which is the diameter of a circle having the same area as the projected area of the inorganic filler. It is a numerical value obtained by dividing by the length (length of the contour line), and is calculated by the following formula. The circularity is 1.00 in a perfect circle.
Circularity = (peripheral length of equivalent circle) / (peripheral length of particle cross-sectional image)
Specifically, for the average circularity, an image magnified at a magnification of 1000 times is observed with a scanning electron microscope, 10 inorganic fillers are arbitrarily selected, and the circularity of each inorganic filler is measured by the above method. However, it is a value calculated as the arithmetic mean value. The circularity, the peripheral length of the equivalent circle, and the peripheral length of the projected image of the particles can be obtained by commercially available image analysis software.
When two or more kinds of inorganic fillers are used in combination, the average circularity of the inorganic fillers means a value as a mixture of two or more kinds of inorganic fillers.

The inorganic filler is not particularly limited in terms of material, particle size and the like as long as the particle size distribution has at least three peaks and contains alumina having a particle size of 1 μm or less.
Examples of the inorganic filler include spherical silica, silica such as crystalline silica, alumina, zircon, magnesium oxide, calcium silicate, calcium carbonate, potassium titanate, silicon carbide, silicon nitride, boron nitride, aluminum nitride, beryllium, and zirconia. Be done. Further, examples of the inorganic filler having a flame-retardant effect include aluminum hydroxide and zinc borate. Among these, alumina is preferable from the viewpoint of high thermal conductivity.
The proportion of alumina in the inorganic filler is preferably 60% by mass to 95% by mass, more preferably 60% by mass to 92% by mass, and further preferably 60% by mass to 90% by mass. ..
As the inorganic filler, alumina and silica may be used in combination. When alumina and silica are used in combination as the inorganic filler, the proportion of alumina in the inorganic filler is preferably 80% by mass to 95% by mass, and the proportion of silica is preferably 5% by mass to 20% by mass, preferably alumina. Is more preferably 82% by mass to 92% by mass, silica is more preferably 8% by mass to 18% by mass, alumina is 85% by mass to 90% by mass, and silica is 10% by mass. It is more preferably mass% to 15% by mass.

The particle size distribution of the inorganic filler has at least three peaks, and preferably has three peaks. The position of the peak in the particle size distribution of the inorganic filler is not particularly limited, and for example, it is preferable to have a peak in the range of 0.3 μm to 0.7 μm, the range of 7 μm to 20 μm, and the range of 30 μm to 70 μm. It is more preferable to have peaks in the range of 0.3 μm to 0.6 μm, the range of 7 μm to 15 μm, and the range of 40 μm to 70 μm.

The particle size distribution of the inorganic filler can be obtained by the following method.
The inorganic filler to be measured is added to the solvent (pure water) in the range of 0.02% by mass to 0.08% by mass, and vibrated with a 110 W bath type ultrasonic cleaner for 1 to 10 minutes to be inorganic. Disperse the filler. About 40 mL of the dispersion is injected into the measuring cell and measured at 25 ° C. The measuring device measures the volume-based particle size distribution with a laser diffraction / scattering type particle size distribution measuring device (for example, Horiba Seisakusho Co., Ltd., LA920 (trade name)). The refractive index of alumina is used as the refractive index. Even when the inorganic filler is a mixture of alumina and an inorganic filler other than alumina, the refractive index of alumina shall be used as the refractive index.

The ratio of alumina to the inorganic particles having a particle diameter of 1 μm or less contained in the inorganic filler is preferably 1% by volume to 40% by volume, more preferably 10% by volume to 35% by volume, and 15 volumes. It is more preferably% to 30% by volume.
The ratio of alumina to the inorganic particles having a particle diameter of 1 μm or less contained in the inorganic filler can be measured by the following method.
For each inorganic particle whose particle size is confirmed to be 1 μm or less by a scanning electron microscope, constituent elements are identified by energy dispersive X-ray spectrum, and the material of the inorganic particle is determined. By determining the volume-based ratio of alumina to 50 inorganic particles of 1 μm or less, the ratio of alumina to the inorganic particles having a particle diameter of 1 μm or less contained in the inorganic filler can be determined. The particle diameter of each inorganic particle is a circle-equivalent diameter, which is the diameter of a circle having the same area as the projected area.

The proportion of alumina in the inorganic particles having a particle diameter of 10 μm or more contained in the inorganic filler is preferably 20% by volume to 60% by volume, more preferably 25% by volume to 55% by volume, and 30% by volume. It is more preferably% to 50% by volume.
The proportion of alumina in the inorganic particles having a particle diameter of 10 μm or more contained in the inorganic filler can be determined in the same manner as the proportion of alumina in the inorganic particles having a particle diameter of 1 μm or less contained in the inorganic filler.

The blending amount of the inorganic filler shall be in the range of 75% by mass to 97% by mass with respect to the entire sealing composition from the viewpoints of hygroscopicity, reduction of linear expansion coefficient, strength improvement and solder heat resistance. It is preferably in the range of 80% by mass to 95% by mass, more preferably.

In order to show a particle size distribution in which the inorganic filler has at least three peaks, for example, a method of blending three types of inorganic fillers having different average particle diameters can be mentioned, but the method is not limited thereto. For example, an inorganic filler having an average particle diameter of 0.3 μm to 0.7 μm, an inorganic filler having an average particle diameter of 7 μm to 20 μm, and an inorganic filler having an average particle diameter of 30 μm to 70 μm may be used in combination. ..
The average particle size of the inorganic filler as a whole is preferably 4 μm to 30 μm, more preferably 5 μm to 25 μm, and even more preferably 6 μm to 20 μm.
The average particle size of the inorganic filler is a laser diffraction / scattering type particle size distribution measuring device (for example, Horiba Co., Ltd.) using a dispersion of the inorganic filler prepared in the same manner as in the case of measuring the particle size distribution of the inorganic filler. In the volume-based particle size distribution measured by LA920 (trade name) manufactured by Mfg. Co., Ltd., it is determined as the particle size (D50%) when the accumulation from the small diameter side is 50%.

(Curing accelerator)
The sealing composition may further contain a curing accelerator. The type of the curing accelerator is not particularly limited, and a known curing accelerator 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; maleic anhydride, 1,4-benzoquinone, 2,5-turquinone, 1,4-naphthoquinone, 2,3-dimethyl as cycloamidine compounds Kinone 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, diazo Compounds with intramolecular polarization formed by adding compounds with π bonds such as phenylmethane and phenol 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- Methylphenyl) Organic phosphine compounds such as phosphine, diphenylphosphine, and phenylphosphine; Intramolecular polarization formed by adding a compound having a π bond such as maleic anhydride, the above quinone compound, diazophenylmethane, and phenol resin to the organic phosphin compound. Phosphorus compounds; tetraphenylborone salts such as tetraphenylphosphonium tetraphenylborate, triphenylphosphine tetraphenylborate, 2-ethyl-4-methylimidazole tetraphenylborate, N-methylmorpholin tetraphenylborate, and derivatives of tetraphenylborone salts. Examples thereof include additions of a phosphine compound such as triphenylphosphonium-triphenylboran and N-methylmorpholintetraphenylphosphonium-tetraphenylborate and a tetraphenylborone salt. As the curing accelerator, one type may be used alone, or two or more types may be used in combination.

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 the curing agent.

(Ion trap agent)
The sealing composition may further contain an ion trap agent.
The ion trapping agent that can be used in the present disclosure is not particularly limited as long as it is a generally used ion trapping agent in the encapsulant used for manufacturing semiconductor devices, and hydrotalcite and the like are used. Can be mentioned. As the ion trapping agent, a compound represented by the following general formula (II-1) or the following general formula (II-2) may be used.

Mg _1-a Al _a (OH) ₂ (CO ₃ ) _{a / 2} · uH ₂ O (II-1)
(In the 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 the 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.)

The ion trap agent is available as a commercial product. As the compound represented by the general formula (II-1), for example, "DHT-4A" (Kyowa Chemical Industry Co., Ltd., trade name) is available as a commercially available product. Further, as a compound represented by the general formula (II-2), for example, "IXE500" (Toagosei Co., Ltd., trade name) is available as a commercially available product.

Examples of ion trapping agents other than the above include hydrous oxides of elements selected from magnesium, aluminum, titanium, zirconium, antimony and the like.
One type of ion trapping agent may be used alone, or two or more types may be used in combination.

When the sealing composition contains an ion trapping agent, the content of the ion trapping agent is 1 part by mass with respect to 100 parts by mass of the epoxy resin in the sealing composition from the viewpoint of realizing sufficient moisture resistance and reliability. The above is preferable. From the viewpoint of fully exerting the effects of the other components, the content of the ion trap agent is preferably 15 parts by mass or less with respect to 100 parts by mass of the epoxy resin in the sealing composition.

The average particle size of the ion trap 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 trap agent can be measured in the same manner as in the case of 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. Examples of the coupling agent include a silane coupling agent and a titanium coupling agent. One type of coupling agent may be used alone, or two or more types may be used in combination.

Examples of the silane coupling agent include vinyltrichlorosilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, and β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane. , Γ-Glysidoxypropyltrimethoxysilane, 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-anilinopropyltrimethoxy Examples include silane, vinyltrimethoxysilane and γ-mercaptopropylmethyldimethoxysilane.

Examples of the titanium coupling agent include isopropyltriisostearoyl titanate, isopropyltris (dioctylpyrophosphate) titanate, isopropyltri (N-aminoethyl-aminoethyl) titanate, tetraoctylbis (ditridecylphosphite) titanate, and tetra (ditridecylphosphite) titanate. 2,2-Diallyloxymethyl-1-butyl) bis (ditridecylphosphite) titanate, bis (dioctylpyrophosphate) oxyacetate titanate, bis (dioctylpyrophosphate) ethylene titanate, isopropyltrioctanoyl titanate, isopropyldimethacrylic iso Examples thereof include stearoyl titanate, isopropyltridodecylbenzenesulfonyl titanate, isopropylisostearoyl diacrylic titanate, isopropyltri (dioctyl phosphate) titanate, isopropyltricylphenyl titanate and tetraisopropylbis (dioctyl phosphate) 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, and from the viewpoint of exerting the effect, it is 0. It is preferably 1% by mass or more.

(Release agent)
The sealing composition may further contain a release agent. The type of release agent is not particularly limited, and a known release agent can be used. Specific examples thereof include higher fatty acids, higher fatty acid esters, carnauba wax and polyethylene wax. As the release agent, one type may be used alone, or two or more types may be used in combination.
When the sealing 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, and from the viewpoint of exerting the effect. Is preferably 0.5% by mass or more.

(Colorants and modifiers)
The sealing composition may contain a colorant (eg, carbon black). In addition, the sealing composition may contain a modifier (for example, silicone and silicone rubber). As the colorant and the modifier, one type may be used alone, or two or more types may be used in combination.

When conductive particles such as carbon black are used as the colorant, the content of the conductive particles is preferably 1% by mass or less of particles having a particle diameter of 10 μm or more.
When the sealing 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 producing sealing composition>
The 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 blending amount with a mixer or the like, kneading the mixture with a hot roll, an extruder or the like, cooling, pulverizing or the like. The state of the sealing composition is not particularly limited and may be powdery, solid, liquid or the like.

<Semiconductor device>
The 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.

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

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

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

(Examples 1 to 11 and Comparative Examples 1 and 2)
After premixing (dry blending) the materials having the formulations shown in Tables 1 to 3, they are kneaded with a biaxial roll (roll surface temperature: about 80 ° C.) for about 15 minutes, cooled and pulverized to form a powdery sealing composition. Manufactured.

The details of the materials in the table are as follows. Further, "-" in the table indicates that the corresponding component is not contained.

(Epoxy resin)
-Epoxy resin 1: Biphenyl type epoxy resin, epoxy equivalent: 186 g / eq
-Epoxy resin 2: Polyfunctional epoxy resin, epoxy equivalent: 167 g / eq
-Epoxy resin 3: Bisphenol type crystalline epoxy resin, epoxy equivalent: 192 g / eq
-Epoxy resin 4: Epoxy F type epoxy resin, epoxy equivalent: 159 g / eq

(Hardener)
-Curing agent 1: Polyfunctional phenol resin, triphenylmethane-type phenol resin having a hydroxyl group equivalent of 102 g / eq-Curing agent 2: Polyfunctional phenol resin, biphenyl-aralkyl resin having a hydroxyl equivalent of 205 g / eq-Curing agent 3: Phenol -Aralkyl resin, hydroxyl group equivalent: 170 g / eq

-Curing accelerator: Phosphorus-based curing accelerator-Coupling agent: Epoxysilane (γ-glycidoxypropyltrimethoxysilane)
-Release agent: Montanic acid ester-Colorant: Carbon black-Ion trap agent: Hydrotalcite-Modifier: Silicone

(Inorganic filler)
-Inorganic filler 1: Mixture of alumina and silica (average particle size: 8.6 μm)
-Inorganic filler 2: silica (average particle size: 9.5 μm)
-Inorganic filler 3: Alumina (average particle size: 0.4 μm)
-Inorganic filler 4: silica (average particle size: 0.8 μm)
-Inorganic filler 5: silica (average particle size: 0.1 μm)
-Inorganic filler 6: silica (average particle size: 13.0 μm)
-Inorganic filler 7: silica (average particle size: 2.2 μm)
-Inorganic filler 8: silica (average particle size: 0.8 μm)
-Inorganic filler 9: Mixture of alumina and silica (average particle size: 7.4 μm)
-Inorganic filler 10: silica (average particle size: 1.5 μm)
-Inorganic filler 11: silica (average particle size: 22.0 μm)
-Inorganic filler 12: Alumina (average particle size: 14.9 μm)
-Inorganic filler 13: Alumina (average particle size: 10.4 μm)
-Inorganic filler 14: Alumina (average particle size: 2.0 μm)
-Inorganic filler 15: Mixture of alumina and silica (average particle size: 43.9 μm)

The positions of the peaks in the particle size distribution of the inorganic fillers of Examples 1 to 11 are as follows.
It had three peaks. In addition, all the sealing compositions according to Examples 1 to 11 contained alumina having a particle size of 1 μm or less. In addition, the average particle size of the entire inorganic filler is shown below.
Example 1: 0.45 μm, 10 μm and 40 μm (average particle size: 8.1 μm)
Example 2: 0.5 μm, 10 μm and 50 μm (average particle size: 8.7 μm)
Example 3: 0.5 μm, 10 μm and 50 μm (average particle size: 7.6 μm)
Example 4: 0.5 μm, 10 μm and 50 μm (average particle size: 7.7 μm)
Example 5: 0.5 μm, 10 μm and 50 μm (average particle size: 6.6 μm)
Example 6: 0.5 μm, 10 μm and 51 μm (average particle size: 6.2 μm)
Example 7: 0.5 μm, 10 μm and 51 μm (average particle size: 7.7 μm)
Example 8: 0.5 μm, 10 μm and 51 μm (average particle size: 6.6 μm)
Example 9: 0.5 μm, 10 μm and 51 μm (average particle size: 10.8 μm)
Example 10: 0.45 μm, 10 μm and 51 μm (average particle size: 6.4 μm)
Example 11: 0.4 μm, 9 μm and 45 μm (average particle size: 7.8 μm)
On the other hand, the positions of the peaks in the particle size distribution of the inorganic filler of Comparative Example 1 were as follows, and had two peaks. Further, the sealing composition according to Comparative Example 1 contained alumina having a particle size of 1 μm or less. In addition, the average particle size of the entire inorganic filler is shown below.
Comparative Example 1: 1.5 μm and 10 μm (average particle size: 11.3 μm)
The positions of the peaks in the particle size distribution of the inorganic filler of Comparative Example 2 were as follows, and had three peaks. Further, the sealing composition according to Comparative Example 2 did not contain alumina having a particle size of 1 μm or less. In addition, the average particle size of the entire inorganic filler is shown below.
Comparative Example 2: 0.5 μm, 10 μm and 50 μm (average particle size: 6.5 μm)

<Evaluation of liquidity>
The fluidity of the sealing composition was evaluated by a spiral flow test.
Specifically, the sealing composition was molded using a spiral flow measuring mold according to EMMI-1-66, and the flow distance (cm) of the molded product of the sealing composition was measured. The sealing composition was molded using a transfer molding machine under the conditions of a mold temperature of 180 ° C., a molding pressure of 6.9 MPa, and a curing time of 120 seconds.
Further, the fluidity was defined as A for 160 cm or more, B for 150 cm or more and less than 160 cm, and C for less than 150 cm.

<Evaluation of thermal conductivity>
The thermal conductivity of the sealing composition was evaluated by the following method.
Specifically, using the prepared sealing composition, transfer molding was performed under the 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 having a mold shape. The cured product obtained was measured by the Archimedes method and the density was ^{2.8g / cm 3 ~3.0g / cm 3} . Further, the thermal diffusivity of the cured product was measured by a laser flash method using a thermal diffusivity measuring device (NETZSCH, LFA467). The thermal conductivity (W / (m · K)) was calculated from the product of the thermal diffusivity measured above, the density measured by the Archimedes method, and the specific heat measured by DSC (differential calorimetry).
Further, the thermal conductivity was defined as A for 2.5 W / (m · K) or more and B for less than 2.5 W / (m · K).

As shown in Tables 4 to 6, from the results of Examples 1 to 11 having three peaks and Comparative Example 1 having two peaks, the inorganic filler was prepared regardless of the ratio of alumina to the inorganic filler. By not having three peaks in the particle size distribution, the fluidity was extremely lowered and the thermal conductivity was lowered.
Further, in Comparative Example 2 in which the inorganic filler does not contain alumina having a particle diameter of 1 μm or less, Examples 1, 5, 6 and 8 which have a particularly large amount of alumina having a particle diameter of 1 μm or less in the inorganic filler, Compared with 10 and 11, the fluidity was equal to or lower, and the thermal conductivity was lower.

The disclosure of Japanese Patent Application No. 2017-254883, filed December 28, 2017, is incorporated herein by reference in its entirety.
All documents, patent applications, and technical standards described herein are to the same extent as if the individual documents, patent applications, and technical standards were specifically and individually stated to be incorporated by reference. Incorporated herein by reference.

Claims (5)

Contains an epoxy resin, a curing agent, and an inorganic filler,
The particle size distribution of the inorganic filler has at least three peaks.
A sealing composition in which the inorganic filler contains alumina having a particle size of 1 μm or less. The sealing composition according to claim 1, wherein the particle size distribution of the inorganic filler has peaks in the range of 0.3 μm to 0.7 μm, the range of 7 μm to 20 μm, and the range of 30 μm to 70 μm. The sealing composition according to claim 1 or 2, wherein the proportion of alumina in the inorganic particles having a particle diameter of 1 μm or less contained in the inorganic filler is 1% by volume to 40% by volume. The sealing composition according to any one of claims 1 to 3, wherein the average circularity of the inorganic filler is 0.80 or more. A semiconductor device comprising a semiconductor element and a cured product of the sealing composition according to any one of claims 1 to 4, wherein the semiconductor element is sealed.