JP7415950B2 - Encapsulation composition and semiconductor device - Google Patents

Description

TECHNICAL FIELD This disclosure relates to encapsulation compositions and semiconductor devices.

In recent years, with miniaturization and higher integration, there has been concern about heat generation inside semiconductor packages. Because heat generation may cause deterioration in the performance of electrical or electronic components including semiconductor packages, members used in semiconductor packages are required to have high thermal conductivity. Therefore, it is required that the sealing material for semiconductor packages has high thermal conductivity.
For example, high thermal conductivity of the sealing material can be achieved by highly filling the inorganic filler.

An example of a sealing material highly filled with an inorganic filler is a semiconductor sealant whose essential components include (A) an epoxy resin, (B) a curing agent, and (D) an inorganic filler containing spherical alumina and spherical silica. an epoxy resin composition for use in which the spherical alumina is (d1) a first spherical alumina having an average particle size of 40 μm or more and 70 μm or less; and (d2) a second spherical alumina having an average particle size of 10 μm or more and 15 μm or less. The spherical silica includes (d3) a first spherical silica having an average particle size of 4 μm or more and 8 μm or less, and (d4) a second spherical silica having an average particle size of 0.05 μm or more and 1.0 μm or less. The total amount of (d3)+(d4) is 17% or more and 23% or less of the total inorganic filler, and the ratio of (d3)/(d4) is (d3)/(d4)=1. An epoxy resin composition for semiconductor encapsulation is known, which is characterized in that the ratio is 1/8 or more and 5/4 or less, and the amount of inorganic filler is 85 to 95% by mass based on the total resin composition (for example, Patent Document (see 1)

Patent Document 1: Japanese Patent Application Publication No. 2006-273920

However, in the epoxy resin composition for semiconductor encapsulation described in Patent Document 1, although a cured product with high thermal conductivity can be obtained by highly filling alumina, which is a highly thermally conductive filler, the fluidity of the encapsulating material is low. It may decrease. Therefore, the development of highly fluid and highly thermally conductive encapsulants is a challenge.

According to one embodiment of the present invention, there is provided a sealing composition that can both obtain a cured product with high thermal conductivity and improve fluidity, and a semiconductor device using the sealing composition.

The present invention includes the following embodiments.
<1>
Epoxy resin and
a hardening agent;
An inorganic filler containing silica particles with a specific surface area of 100 m ² /g or more,
A silane compound having a structure in which a chain hydrocarbon group having 6 or more carbon atoms is bonded to a silicon atom,
A sealing composition containing.
<2>
The sealing composition according to <1>, wherein the cured product obtained when the sealing composition is heated and cured under conditions of a curing temperature of 175° C. and a curing time of 90 seconds has a hardness when heated as Shore D of 70 or more. thing.
<3>
The sealing composition according to <1> or <2>, wherein the content of the inorganic filler is 78% by volume or more based on the entire sealing composition.
<4>
The sealing composition according to any one of <1> to <3>, wherein the curing agent contains a polyfunctional phenolic resin curing agent.
<5>
The sealing composition according to any one of <1> to <4>, wherein the curing agent contains a triphenylmethane type phenolic resin.
<6>
The chain hydrocarbon group according to any one of <1> to <5>, wherein the chain hydrocarbon group has at least one functional group selected from the group consisting of a (meth)acryloyl group, an epoxy group, and an alkoxy group. Sealing composition.
<7>
The encapsulating composition according to any one of <1> to <6>, wherein the chain hydrocarbon group has a (meth)acryloyl group.
<8>
A semiconductor device comprising a semiconductor element and a cured product of the sealing composition according to any one of <1> to <7>, which is obtained by sealing the semiconductor element.

According to one embodiment of the present invention, there is provided a sealing composition that can both obtain a cured product with high thermal conductivity and improve fluidity, and a semiconductor device using the sealing composition.

Hereinafter, embodiments for implementing the encapsulating composition and semiconductor device of the present disclosure will be described in detail. However, the present invention is not limited to the following embodiments. In the following embodiments, the constituent elements (including, for example, elemental steps) are not essential unless otherwise specified. The same applies to numerical values and their ranges, and they do not limit the present invention.

In the present disclosure, numerical ranges indicated using "~" include the numerical values written before and after "~" as minimum and maximum values, respectively.
In the numerical ranges described step by step in this disclosure, the upper limit or lower limit described in one numerical range may be replaced with the upper limit or lower limit of another numerical range described step by step. . Furthermore, in the numerical ranges described in this disclosure, the upper limit or lower limit of the numerical range may be replaced with the values shown in the Examples.
In the present disclosure, each component may contain multiple types of corresponding substances. If 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.
In the present disclosure, each component may include a plurality of types of particles. When a plurality of types of particles corresponding to each component are present in the composition, the particle diameter of each component means a value for a mixture of the plurality of types of particles present in the composition, unless otherwise specified.
In the present disclosure, "(meth)acryloyl group" means at least one of acryloyl group and methacryloyl group, "(meth)acrylic" means at least one of acrylic and methacrylic, and "(meth)acrylate" means acrylic and methacrylate.

<Sealing composition>
The sealing composition of the present disclosure includes an epoxy resin, a curing agent, an inorganic filler containing silica particles having a specific surface area of 100 m ² /g or more, and a chain hydrocarbon group having 6 or more carbon atoms bonded to a silicon atom. A silane compound having the following structure.
Hereinafter, silica particles with a specific surface area of 100 m ² /g or more will be referred to as "specific silica particles", and a silane compound having a structure in which a chain hydrocarbon group having 6 or more carbon atoms is bonded to a silicon atom will be referred to as a "specific silane compound". There is.

Since the sealing composition of the present disclosure contains the above-mentioned specific silane compound, it is possible to obtain a cured product with high thermal conductivity and to improve fluidity.
Generally, a cured product with high thermal conductivity can be obtained by highly filling the inorganic filler. However, as the amount of inorganic filler is increased, the fluidity tends to decrease, and even if the amount of inorganic filler is further increased, the thermal conductivity of the cured product becomes difficult to increase. may reach saturation. On the other hand, in the sealing composition of the present disclosure, by containing the above-mentioned specific silane compound, the fluidity is higher than when the specific silane compound is not contained, and by increasing the filling amount of the inorganic filler, The thermal conductivity of the cured product can be increased. The reason for this is not clear, but by containing a specific silane compound, the dispersibility of the inorganic filler in the sealing composition is improved, which improves the fluidity of the sealing composition, and also improves the dispersibility of the inorganic filler in the sealing composition. It is thought that the function of improving thermal conductivity will be more easily exerted. From the above, it is presumed that the sealing composition of the present disclosure is capable of both obtaining a cured product with high thermal conductivity and improving fluidity.

Each component constituting the sealing composition will be explained below. The sealing composition of the present disclosure contains an epoxy resin, a curing agent, and an inorganic filler, and may contain other components as necessary.

-Epoxy resin-
The sealing composition of the present disclosure contains an epoxy resin. The type of epoxy resin is not particularly limited, and any known epoxy resin can be used.
Specific examples of epoxy resins include phenolic compounds (phenol, cresol, xylenol, resorcinol, catechol, bisphenol A, bisphenol F, etc.) and naphthol compounds (α-naphthol, β-naphthol, dihydroxynaphthalene, etc.). and an aldehyde compound (formaldehyde, acetaldehyde, propionaldehyde, benzaldehyde, salicylaldehyde, etc.) under an acidic catalyst. , orthocresol novolak type epoxy resin, etc.); at least one diglycidyl selected from the group consisting of bisphenols (bisphenol A, bisphenol AD, bisphenol F, bisphenol S, etc.) and biphenols (alkyl-substituted or unsubstituted biphenol, etc.) Ether; epoxidized product of phenol/aralkyl resin; epoxidized product of adduct or polyadduct of phenol compound and at least one selected from the group consisting of dicyclopentadiene and terpene compound; polybasic acid (phthalic acid, dimer acid) etc.) and epichlorohydrin; Glycidylamine type epoxy resin obtained by reacting polyamines (diaminodiphenylmethane, isocyanuric acid, etc.) with epichlorohydrin; Olefin bonds are oxidized with peracid (peracetic acid, etc.) Linear aliphatic epoxy resins obtained by; alicyclic epoxy resins; and the like. Epoxy resins may be used singly or in combination of two or more.

From the viewpoint of preventing corrosion of aluminum wiring or copper wiring on elements such as integrated circuits (ICs), the purity of the epoxy resin is preferably high, and the amount of hydrolyzable chlorine is preferably low. 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 determined by potentiometric titration after dissolving 1 g of the sample epoxy resin in 30 mL of dioxane, adding 5 mL of 1N-KOH methanol solution, and refluxing for 30 minutes.

The melting point or softening point of the epoxy resin is preferably 50°C or higher from the viewpoint of moldability of the sealing composition, and from 50°C to 150°C from the viewpoint of achieving both moldability and kneadability of the sealing composition. The temperature is preferably 60°C to 130°C, even more preferably 70°C to 120°C.
Here, 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 epoxy group equivalent of the epoxy resin is not particularly limited, and is preferably less than 300 g/eq, more preferably from 120 g/eq to 270 g/eq, and from 150 g/eq to 240 g/eq from the viewpoint of moldability. /eq is more preferable.
The above "epoxy group equivalent" can be determined by weighing the epoxy resin to be measured, dissolving it in a solvent such as methyl ethyl ketone, adding acetic acid and tetraethylammonium bromide acetic acid solution, and then performing potentiometric titration using a perchloric acid acetic acid standard solution. It is measured by An indicator may be used for this titration.

Epoxy resin has at least two or more epoxy groups in its molecule. The number of epoxy groups that the epoxy resin has in one molecule is not particularly limited, and examples thereof include 2 to 8, preferably 2 to 6, more preferably 2 to 3, and particularly preferably 2.
Note that the above epoxy group is at least a part of at least one selected from the group consisting of glycidyl group, glycidyloxy group, glycidyloxycarbonyl group, and epoxycycloalkyl group (epoxycyclopentyl group, epoxycyclohexyl group, epoxycyclooctyl group, etc.). may be contained in the molecules of the first epoxy resin.

The epoxy resin preferably has a divalent linking group represented by the following general formula (1) in addition to two or more epoxy groups in the molecule.
In the following general formula (1), * indicates a bond, and R ¹ to R ⁸ each independently represent a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or an aromatic group having 4 to 18 carbon atoms. shows.

In the general formula (1), R ¹ to R ⁴ are each independently preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, more preferably a hydrogen atom or a methyl group, and even more preferably a methyl group.
Furthermore, in the general formula (1), R ⁵ to R ⁸ are each independently preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, more preferably a hydrogen atom or a methyl group, and even more preferably a hydrogen atom.

The content of the epoxy resin in the sealing composition is preferably 2.5% by mass to 6% by mass, more preferably 2.8% by mass to 5.5% by mass, and 3.0% by mass. % to 5.0% by mass is more preferable.
The content of the epoxy resin in the sealing composition excluding the inorganic filler is preferably 40% by mass to 70% by mass, more preferably 45% to 64% by mass, and 48% to 55% by mass. It is more preferable that it is mass %.

-Hardening agent-
The sealing composition of the present disclosure contains a curing agent. The type of curing agent is not particularly limited, and any known curing agent can be used.
Examples of the curing agent include a phenol curing agent, an amine curing agent, an acid anhydride curing agent, a polymercaptan curing agent, a polyaminoamide curing agent, an isocyanate curing agent, a blocked isocyanate curing agent, and the like. From the viewpoint of obtaining a sealing composition with excellent reflow resistance while maintaining fluidity, the curing agent is preferably a phenol curing agent, an amine curing agent, or an acid anhydride curing agent, and more preferably a phenol curing agent. One type of curing agent may be used alone, or two or more types may be used in combination.

Examples of the phenol curing agent include phenol resins and polyhydric phenol compounds having two or more phenolic hydroxyl groups in one molecule. Specifically, the phenol curing agent includes polyhydric phenol compounds such as resorcinol, catechol, bisphenol A, bisphenol F, substituted or unsubstituted biphenol; phenol, cresol, xylenol, resorcinol, catechol, bisphenol A, bisphenol F, At least one phenolic compound selected from the group consisting of phenolic compounds such as phenylphenol and aminophenol and naphthol compounds such as α-naphthol, β-naphthol, and dihydroxynaphthalene; and an aldehyde compound such as formaldehyde, acetaldehyde, and propionaldehyde; Novolac-type phenolic resin obtained by condensing or co-condensing under acidic catalyst; aralkyl-type phenolic resin (phenol aralkyl resin, paraxylylene modified phenolic resin; metaxylylene modified phenolic resin; melamine modified phenolic resin; terpene modified phenolic resin; dicyclopentadiene type phenolic resin synthesized by copolymerization of the above phenolic compound and dicyclopentadiene; Cyclopentadiene-type naphthol resin; cyclopentadiene-modified phenol resin; polycyclic aromatic ring-modified phenol resin; biphenyl-type phenol resin; condensation or Triphenylmethane type phenol resins obtained by co-condensation; phenol resins obtained by copolymerizing two or more of these; and the like. These phenol resins and polyhydric phenol compounds may be used alone or in combination of two or more.

Among these, the phenol curing agent is preferably a polyfunctional phenol resin curing agent, and among these, a novolac type phenol resin, an aralkyl type phenol resin, and a triphenylmethane type phenol resin are preferable, and a triphenylmethane type phenol resin is more preferable.
Here, the "polyfunctional phenolic resin curing agent" is a curing agent that is a phenolic resin having three or more functional groups (ie, hydroxyl groups) in one molecule.

Examples of the triphenylmethane type phenol resin include phenol resins represented by the following general formula (2).

In the general formula (2), R ¹¹ to R ¹⁵ each independently represent a monovalent organic group having 1 to 18 carbon atoms, b1 to b2 each independently represent an integer of 0 to 4, b3 represents an integer of 0 to 3, b4 to b5 each independently represents an integer of 0 to 4, and n represents an integer of 0 to 10.

The monovalent organic group having 1 to 18 carbon atoms represented by R ¹¹ to R ¹⁵ in general formula (2) includes a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, and a substituted or unsubstituted alkoxy group. Examples include aryl groups, substituted or unsubstituted aralkyl groups, and the like.
b1 to b5 in general formula (2) are preferably integers of 0 to 1, more preferably 0, n in general formula (2) is preferably 1 to 7, and 2 -5 is more preferable.

The functional group equivalent of the curing agent is not particularly limited, and from the viewpoint of moldability, it is preferably 70 g / eq to 500 g / eq, more preferably 70 g / eq to 300 g / eq, and 80 g / eq to 250 g /eq is more preferable. Note that the functional group equivalent refers to a value measured in accordance with JIS K 0070:1992.

When the curing agent is solid, its softening point or melting point is not particularly limited. The softening point or melting point of the curing agent is preferably 40°C to 180°C from the viewpoint of moldability and reflow resistance, and the softening point or melting point is more preferably 50°C to 130°C, even more preferably 55°C to 100°C.
The melting point or softening point of the curing agent is a value measured in the same manner as the melting point or softening point of the epoxy resin.

The mixing ratio of the epoxy resin and the curing agent is determined from the viewpoint of keeping the amount of unreacted components to a minimum, so that the equivalent of the functional group of the curing agent (for example, the phenolic hydroxyl group in the case of phenolic resin) is equal to 1 equivalent of the epoxy group of the epoxy resin. The curing agent is preferably blended in an amount of 0.5 to 1.5 equivalents, particularly preferably 0.7 to 1.2 equivalents. .

-Inorganic filler-
The sealing composition of the present disclosure includes at least specific silica particles (i.e., silica particles having a specific surface area of 100 m ² /g or more) as an inorganic filler, and optionally includes fillers other than specific silica particles (hereinafter referred to as " may also contain other fillers (also referred to as "other fillers").
When the sealing composition contains the specific silica particles, the generation of burrs is suppressed when a semiconductor element is sealed by a transfer molding method, for example.
The sealing composition preferably contains specific silica particles and other fillers as inorganic fillers.

The specific surface area of the specific silica particles is 100 m ² /g or more, and from the viewpoint of suppressing burrs, it is preferably 150 m ² /g to 300 m ² /g, and 170 m ² /g to 270 m ² /g. is more preferable, and even more preferably 190 m ² /g to 230 m ² /g.
The specific surface area (ie, BET specific surface area) of the inorganic filler can be measured from the nitrogen adsorption capacity according to JIS Z 8830:2013. As the evaluation device, AUTOSORB-1 (trade name) manufactured by QUANTACHROME can be used. When measuring the BET specific surface area, it is thought that moisture adsorbed on the sample surface and structure affects the gas adsorption ability, so it is preferable to first perform pretreatment to remove moisture by heating. .
In the pretreatment, the measurement cell containing 0.05 g of the measurement sample was depressurized to 10 Pa or less using a vacuum pump, heated to 110°C, held for more than 3 hours, and then heated to room temperature (while maintaining the depressurized state). Cool naturally to 25°C. After performing this pretreatment, the evaluation temperature is set to 77 K, and the evaluation pressure range is measured as relative pressure (equilibrium pressure with respect to saturated vapor pressure) less than 1.

From the viewpoint of burr suppression and moldability, the content of the specific silica particles is preferably 0.15% by mass to 1.0% by mass, and 0.3% by mass based on the entire inorganic filler contained in the sealing composition. % to 0.8% by mass is more preferred, and even more preferably 0.4% to 0.7% by mass.

One type of other fillers may be used alone, or two or more types may be used in combination.
Examples of cases in which two or more types of other fillers are used in combination include cases in which two or more types of inorganic fillers having different components, average particle diameters, shapes, etc. are used.
The shape of the other fillers is not particularly limited, and examples include powder, spherical, and fibrous shapes. From the viewpoint of fluidity and mold abrasion resistance during molding of the sealing composition, the shape of the other filler is preferably spherical.

The other fillers preferably include alumina from the viewpoint of high thermal conductivity. All of the other fillers may be alumina, or alumina and a filler other than alumina may be used together.
Other fillers other than alumina include silica (spherical silica, crystalline silica, etc.) with a specific surface area of less than 100 m ² /g, zircon, magnesium oxide, calcium silicate, calcium carbonate, potassium titanate, silicon carbide, silicon nitride, Examples include boron nitride, beryllia, and zirconia. Further, examples of inorganic fillers having a flame retardant effect include aluminum hydroxide, zinc borate, and the like.

The content of the inorganic filler (for example, if the inorganic filler contains specific silica particles and other fillers, the content of the entire inorganic filler including the specific silica particles and other fillers) is determined by the hygroscopicity, linear From the viewpoint of reducing the coefficient of expansion, improving strength and soldering heat resistance, it is preferably 60 volume % or more, more preferably 70 volume % or more, and 75 volume % or more based on the entire sealing composition. It is even more preferable that there be.
Further, from the viewpoint of high thermal conductivity, the content of the inorganic filler is preferably 78% by volume or more, more preferably 80% by volume or more, based on the entire sealing composition. From the viewpoint of moldability of the sealing composition, the content of the inorganic filler is preferably 95% by volume or less, more preferably 90% by volume or less, and 85% by volume or less based on the entire sealing composition. More preferably, it is less than or equal to % by volume. The content of the inorganic filler is preferably 78% to 90% by volume, more preferably 78% to 85% by volume, and 80% by volume from the viewpoint of achieving both high thermal conductivity and moldability of the sealing composition. More preferably 85% by volume.

The average particle diameter of the inorganic filler (for example, if the inorganic filler contains specific silica particles and other fillers, the average particle diameter of the entire inorganic filler including the specific silica particles and other fillers) is 4 μm to It is preferably 100 μm, more preferably 7 μm to 70 μm, even more preferably 7 μm to 40 μm.
The thermal conductivity of the cured product of the sealing composition tends to increase as the average particle size of the inorganic filler increases.
The average particle diameter of the inorganic filler can be measured by the following method.

Add the inorganic filler to be measured to a solvent (pure water) in a range of 1% to 5% by mass together with 1% to 8% by mass of a surfactant, and wash in a 110W ultrasonic cleaner for 30 seconds to 5%. Vibrate for a minute to disperse the inorganic filler. About 3 mL of the dispersion liquid is injected into a measurement cell and measured at 25°C. The measuring device measures the volume-based particle size distribution using a laser diffraction particle size distribution meter (Horiba, Ltd., LA920). The average particle diameter is determined 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 is used as the refractive index.

The specific surface area of the inorganic filler (for example, if the inorganic filler contains specific silica particles and other fillers, the specific surface area of the entire inorganic filler including the specific silica particles and other fillers) depends on fluidity and moldability. From the viewpoint of performance, it is preferably 0.7 m ² /g to 4.0 m ² /g, more preferably 0.9 m ² /g to 3.0 m ² /g, and 1.0 m ² /g More preferably, it is 2.5 m ² /g.
The fluidity of the sealing composition tends to increase as the specific surface area of the inorganic filler decreases.

-Specific silane compounds-
The sealing composition of the present disclosure contains a specific silane compound (that is, a silane compound having a structure in which a chain hydrocarbon group having 6 or more carbon atoms is bonded to a silicon atom).
The specific silane compound has a structure in which a chain hydrocarbon group having 6 or more carbon atoms (hereinafter, a chain hydrocarbon group having 6 or more carbon atoms is also simply referred to as a chain hydrocarbon group) is bonded to a silicon atom. The chain hydrocarbon group may be branched and may have a substituent. In addition, in this disclosure, the number of carbon atoms in a chain hydrocarbon group means the number of carbon atoms not including branched or substituent carbons. The chain hydrocarbon group may or may not contain an unsaturated bond, and preferably does not contain an unsaturated bond.
It is believed that the specific silane compound functions as a coupling agent for the inorganic filler in the sealing composition.

The number of chain hydrocarbon groups bonded to silicon atoms in the specific silane compound may be 1 to 4, preferably 1 to 3, more preferably 1 or 2, and 1. is even more preferable.

When the number of chain hydrocarbon groups bonded to silicon atoms in a specific silane compound is 1 to 3, atoms or atomic groups other than the chain hydrocarbon groups bonded to silicon atoms are not particularly limited, and each independently Additionally, it may be a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group, an aryl group, an aryloxy group, etc. Among them, it is preferable that one or more alkoxy groups are bonded to the silicon atom in the specific silane compound in addition to the chain hydrocarbon group, and one chain hydrocarbon group and three alkoxy groups are bonded to the silicon atom in the specific silane compound. is more preferably bonded to a silicon atom.

The number of carbon atoms in the chain hydrocarbon group of the specific silane compound is 6 or more, preferably 7 or more, and more preferably 8 or more from the viewpoint of suppressing viscosity. There is no particular restriction on the upper limit of the number of carbon atoms in the chain hydrocarbon group of the specific silane compound, and from the viewpoint of dispersibility in the resin, balance of physical properties of the cured product, etc., it is preferably 12 or less, and preferably 11 or less. More preferably, it is 10 or less.

When the chain hydrocarbon group has a substituent, the substituent is not particularly limited. The substituent may be present at the end of the chain hydrocarbon group or at the side chain of the chain hydrocarbon group.

The chain hydrocarbon group preferably has at least one functional group (hereinafter also referred to as "specific functional group") selected from the group consisting of a (meth)acryloyl group, an epoxy group, and an alkoxy group; ) It is more preferable to have at least one functional group selected from the group consisting of an acryloyl group and an epoxy group, and it is even more preferable to have a (meth)acryloyl group. The specific functional group may be present at the end of the chain hydrocarbon group or at the side chain of the chain hydrocarbon group. From the viewpoint of suppressing viscosity, it is preferable that the specific functional group exists at the end of the chain hydrocarbon group.

When the chain hydrocarbon group has a (meth)acryloyl group, the (meth)acryloyl group may be bonded directly to the chain hydrocarbon group or may be bonded via another atom or atomic group. . For example, the chain hydrocarbon group may have a (meth)acryloyloxy group. Among these, it is preferable that the chain hydrocarbon group has a methacryloyloxy group.

When the chain hydrocarbon group has an epoxy group, the epoxy group may be bonded directly to the chain hydrocarbon group or may be bonded via another atom or atomic group. For example, the chain hydrocarbon group may have a glycidyloxy group, an alicyclic epoxy group, or the like. Among these, it is preferable that the chain hydrocarbon group has a glycidyloxy group.

When the chain hydrocarbon group has an alkoxy group, the alkoxy group may be bonded directly to the chain hydrocarbon group or may be bonded through another atom or atomic group, and the chain hydrocarbon group Preferably, it is directly bonded to. The alkoxy group is not particularly limited, and may be a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, or the like. Among these, from the viewpoint of easy availability, it is preferable that the chain hydrocarbon group has a methoxy group.

The equivalent weight (molecular weight/number of functional groups) of at least one functional group selected from the group consisting of (meth)acryloyl group, epoxy group, and alkoxy group in the specific silane compound is not particularly limited. From the viewpoint of reducing the viscosity of the sealing composition, it is preferably 200 g/eq to 420 g/eq, more preferably 210 g/eq to 405 g/eq, and preferably 230 g/eq to 390 g/eq. More preferred.

Specific silane compounds include hexyltrimethoxysilane, heptyltrimethoxysilane, octyltrimethoxysilane, hexyltriethoxysilane, heptyltriethoxysilane, octyltriethoxysilane, 6-glycidoxyhexyltrimethoxysilane, and 7-glycid. xyheptyltrimethoxysilane, 8-glycidoxyoctyltrimethoxysilane, 6-(meth)acryloxyhexyltrimethoxysilane, 7-(meth)acryloxyheptyltrimethoxysilane, 8-(meth)acryloxyoctyltrimethoxy Examples include silane and decyltrimethoxysilane. Among these, from the viewpoint of reducing the viscosity of the sealing composition, the specific silane compounds are preferably 8-glycidoxyoctyltrimethoxysilane and 8-methacryloxyoctyltrimethoxysilane. One type of specific silane compound may be used alone, or two or more types may be used in combination.

The specific silane compound may be synthesized or a commercially available one may be used. Commercially available specific silane compounds include KBM-3063 (hexyltrimethoxysilane), KBE-3063 (hexyltriethoxysilane), KBE-3083 (octyltriethoxysilane), and KBM-4803 (manufactured by Shin-Etsu Chemical Co., Ltd.). Examples include 8-glycidoxyoctyltrimethoxysilane), KBM-5803 (8-methacryloxyoctyltrimethoxysilane), and KBM-3103C (decyltrimethoxysilane).

The content of the specific silane compound in the sealing composition is not particularly limited. The content of the specific silane compound may be 0.01 parts by mass or more, or 0.02 parts by mass or more with respect to 100 parts by mass of the inorganic filler. Further, the content of the specific silane compound is preferably 5 parts by mass or less, more preferably 2.5 parts by mass or less, based on 100 parts by mass of the inorganic filler. When the content of the specific silane compound is 0.01 part by mass or more based on 100 parts by mass of the inorganic filler, a composition with high fluidity tends to be obtained. When the content of the specific silane compound is 5 parts by mass or less based on 100 parts by mass of the inorganic filler, the moldability of the package tends to be further improved. From the viewpoint of achieving both fluidity and moldability of the package, the content of the specific silane compound is preferably 0.05 parts by mass to 2.0 parts by mass, and 0.1 parts by mass based on 100 parts by mass of the inorganic filler. The amount is more preferably 1.5 parts by weight, and even more preferably 0.2 parts by weight to 1.0 parts by weight.
Further, the content of the specific silane compound is preferably 3% by mass or less, more preferably 2% by mass or less, and even more preferably 1% by mass or less, based on the entire sealing composition, so that the effect can be exhibited. From the viewpoint, it is preferably 0.1% by mass or more, more preferably 0.15% by mass or more, and even more preferably 0.2% by mass or more.

-Other ingredients-
(Other coupling agents)
In addition to the specific silane compound, the sealing composition may further contain other coupling agents. Other coupling agents are not particularly limited as long as they are commonly used in sealing compositions using epoxy resins. Other coupling agents include silane compounds (excluding specific silane compounds) such as epoxysilane, mercaptosilane, aminosilane, alkylsilane, ureidosilane, and vinylsilane, titanium compounds, aluminum chelate compounds, aluminum/zirconium compounds, etc. Examples of known coupling agents include: The other coupling agents may be used alone or in combination of two or more.

When the sealing composition contains a coupling agent other than the specific silane compound, the total content of the specific silane compound and the other coupling agent is 0.01 parts by mass or more based on 100 parts by mass of the inorganic filler. The amount may be 0.02 parts by mass or more. Further, the total content of the specific silane compound and other coupling agents is preferably 5 parts by mass or less, more preferably 2.5 parts by mass or less, based on 100 parts by mass of the inorganic filler. When the total content of the specific silane compound and other coupling agent is 0.01 parts by mass or more based on 100 parts by mass of the inorganic filler, a composition with high fluidity tends to be obtained. When the total content of the specific silane compound and other coupling agents is 5 parts by mass or less based on 100 parts by mass of the inorganic filler, the moldability of the package tends to be further improved. The total content of the specific silane compound and other coupling agents is 0.05 parts by mass to 2.0 parts by mass based on 100 parts by mass of the inorganic filler, from the viewpoint of achieving both fluidity and moldability of the package. is preferable, 0.1 parts by weight to 1.5 parts by weight is more preferable, and even more preferably 0.2 parts by weight to 1.0 parts by weight.
Further, the total content of the specific silane compound and other coupling agents is preferably 3% by mass or less, more preferably 2% by mass or less, and further preferably 1% by mass or less based on the entire sealing composition. Preferably, from the viewpoint of exhibiting the effect, the content is preferably 0.1% by mass or more, more preferably 0.15% by mass or more, and even more preferably 0.2% by mass or more.

When the sealing composition contains a coupling agent other than the specific silane compound, from the viewpoint of favorably exhibiting the action of the specific silane compound, other coupling agents should be added to the total amount of the specific silane compound and other coupling agent. The content of the agent is preferably 90% by mass or less, more preferably 70% by mass or less, even more preferably 50% by mass or less, particularly preferably 40% by mass or less, and 20% by mass or less. % or less is extremely preferred, and 10% by mass or less is most preferred.

(hardening accelerator)
The sealing composition may further contain a curing accelerator. The type of curing accelerator is not particularly limited, and any known curing accelerator can be used.
Specific examples of the curing accelerator include 1,8-diaza-bicyclo[5.4.0]undecene-7, 1,5-diaza-bicyclo[4.3.0]nonene, and 5,6-dibutyl. Cyclamidine compounds such as amino-1,8-diaza-bicyclo[5.4.0]undecene-7; maleic anhydride, 1,4-benzoquinone, 2,5-torquinone, 1,4-naphthoquinone in the cycloamidine compound , 2,3-dimethylbenzoquinone, 2,6-dimethylbenzoquinone, 2,3-dimethoxy-5-methyl-1,4-benzoquinone, 2,3-dimethoxy-1,4-benzoquinone, phenyl-1,4-benzoquinone Compounds with intramolecular polarization obtained by adding compounds with π bonds such as quinone compounds, diazophenylmethane, and phenol resin; benzyldimethylamine, triethanolamine, dimethylaminoethanol, tris(dimethylaminomethyl)phenol, etc. Tertiary amine compounds; derivatives of tertiary amine compounds; imidazole compounds such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole; derivatives of imidazole compounds; tributylphosphine, methyldiphenylphosphine, triphenyl Organic phosphine compounds such as phosphine, tris(4-methylphenyl)phosphine, diphenylphosphine, and phenylphosphine; Compounds with π bonds such as maleic anhydride, the above quinone compounds, diazophenylmethane, and phenol resins are added to organic phosphine compounds. Phosphorus compounds having intramolecular polarization; tetraphenylboron salts such as tetraphenylphosphonium tetraphenylborate, triphenylphosphine tetraphenylborate, 2-ethyl-4-methylimidazole tetraphenylborate, N-methylmorpholine tetraphenylborate; Derivatives of tetraphenylboron salts; adducts of tetraphenylboron salts with phosphine compounds such as triphenylphosphonium-triphenylborane and N-methylmorpholinetetraphenylphosphonium-tetraphenylborate; and the like. One type of curing accelerator may be used alone or two or more types may be used in combination.

Among these, the curing accelerator is preferably a phosphorus-based curing accelerator, and among these, an organic phosphine compound, an adduct of an organic phosphine compound, and an adduct of a phosphine compound and a tetraphenyl boron salt are more preferable, and organic phosphine compounds and Adducts of organic phosphine compounds are more preferred, and compounds obtained by adding a quinone compound to an organic phosphine compound are particularly preferred.
Note that the "phosphorus-based curing accelerator" is a curing accelerator having a phosphorus atom.

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

(ion trap agent)
The encapsulation 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 a commonly used ion trapping agent in sealing materials used for manufacturing semiconductor devices. Examples of the ion trapping agent include compounds represented by the following general formula (3) or the following general formula (4).

Mg _1-a Al _a (OH) ₂ (CO ₃ ) _a/2・uH ₂ O (3)
(In general formula (3), a is 0<a≦0.5, and u is a positive number.)
BiO _b (OH) _c (NO ₃ ) _d (4)
(In general formula (4), 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 the compound represented by the general formula (3), for example, "DHT-4A" (Kyowa Chemical Industry Co., Ltd., trade name) is available as a commercial product. Further, as a compound represented by the general formula (4), for example, "IXE500" (Toagosei Co., Ltd., trade name) is available as a commercial product.

In addition, examples of ion trapping agents other than those mentioned 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 preferably 1 part by mass or more per 100 parts by mass of the epoxy resin from the viewpoint of achieving sufficient moisture resistance reliability. . From the viewpoint of fully exhibiting the effects of other components, the content of the ion trapping agent is preferably 15 parts by mass or less based on 100 parts by mass of the epoxy resin.

Further, 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 diameter of the ion trapping agent can be measured in the same manner as in the case of the inorganic filler.

(Release agent)
The sealing composition may further contain a mold release agent. The type of mold release agent is not particularly limited, and any known mold release agent can be used. Specifically, examples of the mold release agent include higher fatty acids, carnauba wax, montan wax, polyethylene wax, and the like. One type of mold release agent may be used alone, or two or more types may be used in combination.
When the sealing composition contains a mold release agent, the content of the mold release agent is preferably 10% by mass or less based on 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.

(Colorants and modifiers)
The encapsulant composition may also contain a colorant (such as carbon black). Moreover, the sealing composition may contain a modifier (silicone, silicone rubber, etc.). The colorant and the modifier may be used alone or in combination of two or more.

When using conductive particles such as carbon black as a coloring agent, it is preferable that the content of conductive particles having a particle diameter of 10 μm or more is 1% by mass or less.
When the sealing composition contains conductive particles, the content of the conductive particles is preferably 3% by mass or less based on the total amount of the epoxy resin and the curing agent.

(Other additives)
The sealing composition may further contain other additives as necessary.
Other additives include flame retardants, anion exchangers, plasticizers, and the like. Moreover, various additives well known in the art may be added to the sealing composition as necessary.

<Method for producing sealing composition>
The method for producing the sealing composition is not particularly limited, and any known method can be used. For example, a sealing composition can be produced by sufficiently mixing a mixture of raw materials in a predetermined amount using a mixer or the like, then kneading using a hot roll, extruder, or the like, and performing processing such as cooling and pulverization. The state of the sealing composition is not particularly limited, and may be in a powder, solid, liquid, or the like.

<Characteristics of sealing composition>
When the sealing composition is heated and cured under the conditions of a curing temperature of 175° C. and a curing time of 90 seconds, the hardness at the time of heating indicated by Shore D of the cured product is preferably 70 or more, and preferably 74 or more. More preferably, it is 76 or more.
When the hot hardness is within the above range, continuous moldability when sealing a semiconductor element by a transfer molding method is improved.

<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, which seals the semiconductor element.

The method of sealing a semiconductor element using a sealing composition is not particularly limited, and any known method can be applied. Transfer molding is commonly used, but compression molding, injection molding, compression molding, and the like may also be used.

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

An embodiment of the present invention will be described below with reference to the following examples, but the present invention is not limited thereto. Moreover, the numerical values in the table mean "parts by mass" unless otherwise specified.

<Examples 1 to 5 and Comparative Examples 1 to 5>
The components shown below were premixed (dry blended) at the blending ratios (parts by mass) shown in Tables 1 and 2, then kneaded in a twin-screw kneader, cooled and pulverized to produce a powdery sealing composition.
The details of the components shown in Tables 1 and 2 are as follows.

(A) Epoxy resin Epoxy resin A1: Mitsubishi Chemical Corporation, product name "YX4000H", epoxy group equivalent "192 g/eq", softening point "107°C", biphenyl type epoxy resin, represented by the above general formula (1) Epoxy resin (B) curing agent having a divalent linking group Curing agent B1: Triphenylmethane type phenol resin, Air Water Co., Ltd., product name "HE910-09", hydroxyl group equivalent "104 g/eq", softening point "80"℃'', phenolic resin (C) curing accelerator represented by the general formula (2) Cure accelerator C1: Phosphorous curing accelerator (adduct of tributylphosphine and benzoquinone)
(D) Coupling agent Coupling agent D1: 3-methacryloxypropyltrimethoxysilane, Shin-Etsu Chemical Co., Ltd., product name "KBM-503" Silane compound having a hydrocarbon group with 3 carbon atoms Coupling agent D2: 8- Methacryloxyoctyltrimethoxysilane, Shin-Etsu Chemical Co., Ltd., product name "KBM-5803", silane compound having a chain hydrocarbon group with 8 carbon atoms

(E) Mold release agent Mold release agent E1: Montan wax, Clariant, product name "HW-E"
(F) Colorant Pigment F1: Carbon black, Mitsubishi Chemical Corporation, trade name "MA600"
(G) Additive Additive G1: Triphenylphosphine oxide (H) Modifier Modifier H1: Silicone, Dow Corning Toray Co., Ltd., product name "BY16-876"

(I) Inorganic filler Filler I1: Silica particles, spherical, specific surface area "190 to 210 m ² /g", specific silica particles Filler I2: Alumina particles, spherical, average particle diameter "0.7 μm"
Filler I3: Alumina particles, spherical, average particle diameter "10 μm"

-evaluation-
The properties of the sealing compositions produced in Examples and Comparative Examples were evaluated by the following property tests. The evaluation results are shown in Tables 1 and 2 below.

(Hardness when heated)
The sealing composition obtained above was molded using a transfer molding machine under the conditions of a mold temperature of 175°C, a molding pressure of 6.9 MPa, and a curing time of 90 seconds to form a disc shape of 50 mm in diameter x 3 mm in thickness. A certain test piece was prepared. Immediately after molding, the hot hardness was measured using a Shore D type hardness meter (Kobunshi Keiki Co., Ltd., Asker, Type D durometer).

(gel time)
Curability was evaluated based on gel time measured as follows using a gelling tester.
Place 0.5 g of the sealing composition obtained above on a hot plate heated to 175°C, and use a jig to rotate the sample 2.0 cm to 2 cm at a rotation speed of 20 rpm to 25 rpm. It was spread evenly into a .5 cm circle. The time from when the sample was placed on the hot plate until the sample lost its viscosity, turned into a gel state, and peeled off from the hot plate was measured, and this time was measured as gel time (sec).
The results are shown in Tables 1 and 2. When the same amount of catalyst is used for 100 parts by mass of epoxy, the shorter the gel time, the better the curability.

(Disk flow (DF))
The sealing composition obtained above was passed through a two-stage sieve (upper stage: 2.38 mm, lower stage: 0.5 mm), and 7 g of the sample remaining in the lower stage was weighed. The sealing composition was placed on a smooth mold heated to 180°C, and an 8 kg smooth mold also heated to 180°C was placed on top of the sample and left for 60 seconds. Thereafter, the average value (mm) of the diameter (mm) and minor axis (mm) of the obtained disc-shaped molded product was determined, and the average value (mm) was defined as the disc flow (DF).
The results are shown in Tables 1 and 2. The longer the disc flow, the better the fluidity.

(Bari)
15 g of the sealing composition obtained above was placed on a mold at 180° C. on a press hot plate and molded for a curing time of 90 seconds. After molding, use calipers to measure the length of the longest part of the 50 μm, 30 μm, 20 μm, 10 μm, 5 μm, and 2 μm slits in which the sealing composition has flowed, and use this measurement value. It has a burr length.
As a result, it was found that in all of Examples 1 to 5, the burr length was 10 mm or less, and the occurrence of burrs was suppressed.

(Thermal conductivity)
Using the sealing composition obtained above, a test piece for thermal conductivity evaluation was produced using a transfer molding machine under conditions of a mold temperature of 175° C. to 180° C., a molding pressure of 7 MPa, and a curing time of 300 seconds. Next, the thermal diffusivity in the thickness direction of the molded test piece was measured. The thermal diffusivity was measured by a laser flash method (device: LFA467 nanoflash, NETZSCH). The pulsed light irradiation was performed under the conditions of a pulse width of 0.31 (ms) and an applied voltage of 247V. The measurement was performed at an ambient temperature of 25°C±1°C. Further, the density of the above test piece was measured using an electronic hydrometer (AUX220, Shimadzu Corporation). For the specific heat, the theoretical specific heat of the sealing composition calculated from the literature value of the specific heat of each material and the blending ratio was used.
Thermal conductivity values were then obtained by multiplying the thermal diffusivity by the specific heat and density using equation (5).
λ=α×Cp×ρ...Formula (5)
(In formula (5), λ is thermal conductivity (W/(m・K)), α is thermal diffusivity (m ² /s), Cp is specific heat (J/(kg・K)), and ρ is density (kg/m ³ ).)
The results are shown in Tables 1 and 2.

In Tables 1 and 2, "average particle diameter of filler" means the volume-based average particle diameter of the whole inorganic filler used, and "filler content" means the whole inorganic filler used with respect to the whole sealing composition. It means the content rate of
As is clear from the evaluation results in Tables 1 and 2, the sealing compositions of Examples 1 to 5 containing the specific silane compound were compared to the sealing compositions of Comparative Examples 1 to 5 that did not contain the specific silane compound. As a result, a cured product with high fluidity and high thermal conductivity is obtained. In addition, in the sealing compositions of Comparative Examples 1 to 5, the rate of increase in thermal conductivity with respect to increase in filler content was low, and the thermal conductivity was in a saturated state, whereas in the sealing compositions of Examples 1 to 3. It can be seen that the thermal conductivity of the sealing composition increases as the filler content increases.

The disclosure of Japanese Patent Application No. 2018-239254 filed on December 21, 2018 is incorporated herein by reference in its entirety.
All documents, patent applications, and technical standards mentioned herein are incorporated by reference to the same extent as if each individual document, patent application, and technical standard was specifically and individually indicated to be incorporated by reference. Incorporated herein.

Claims (7)

Epoxy resin and
a hardening agent;
An inorganic filler containing silica particles with a specific surface area of 100 m ² /g or more,
A silane compound having a structure in which a chain hydrocarbon group having 6 or more carbon atoms is bonded to a silicon atom,
A sealing composition containing
A sealing composition, wherein the cured product obtained when the sealing composition is heated and cured under conditions of a curing temperature of 175° C. and a curing time of 90 seconds has a hardness when heated as Shore D of 70 or more. The sealing composition according to claim 1, wherein the content of the inorganic filler is 78% by volume or more based on the entire sealing composition. The sealing composition according to claim 1 or 2 , wherein the curing agent contains a polyfunctional phenolic resin curing agent. The sealing composition according to any one of claims 1 to 3 , wherein the curing agent contains a triphenylmethane type phenolic resin. 5. The chain hydrocarbon group according to any one of claims 1 to 4 , wherein the chain hydrocarbon group has at least one functional group selected from the group consisting of a (meth)acryloyl group, an epoxy group, and an alkoxy group. Sealing composition. The sealing composition according to any one of claims 1 to 5 , wherein the chain hydrocarbon group has a (meth)acryloyl group. 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.