JP6857836B2 - Epoxy resin composition for encapsulation, cured product, and semiconductor device - Google Patents

Description

The present invention relates to a sealing epoxy resin composition, a cured product of the sealing epoxy resin composition, and a semiconductor device sealed with a cured product of the sealing epoxy resin composition.

Conventionally, in order to protect semiconductor elements such as transistors, ICs, and LSIs from the external environment and improve the handleability of semiconductor elements, the semiconductor elements are packaged in plastic, for example, sealed with an epoxy resin composition. Therefore, a semiconductor device is being obtained.

Generally, the epoxy resin composition contains a curing accelerator in order to accelerate the curing reaction during molding. Examples of the curing accelerator include amines, imidazole compounds, nitrogen-containing heterocyclic compounds such as 1,8-diazabicyclo (5,4,0) undecene-7, phosphine compounds, quaternary ammonium compounds, and quaternary ammonium compounds. Examples thereof include a higher phosphonium compound and an arsonium compound.

In particular, an epoxy resin composition containing a quaternary phosphonium compound is used as a sealing material for thin packages that require high fluidity because it is excellent in moisture resistance reliability and storage stability. Among the quaternary phosphonium compounds, tetraphenylphosphonium / tetraphenylborate (hereinafter referred to as TPP-K) is generally used. Since TPP-K is very stable and has low catalytic activity as it is, a phenol resin salt obtained by heating TPP-K together with a phenol resin in advance is blended in the epoxy resin composition. However, a small amount of benzene is produced when the phenol resin salt of TPP-K is produced. This benzene is released from the epoxy resin composition to the environment, causing environmental deterioration.

As a curing accelerator that does not cause such a problem, a phenol resin salt of an alkyl quaternized phosphonium derived from triphenylphosphonium (hereinafter referred to as TPP) has been proposed (see Patent Documents 1 and 2).

However, since the epoxy resin composition containing the curing accelerator described in Patent Documents 1 and 2 is easily cured, it is difficult to store it for a long period of time. Further, when the epoxy resin composition is heated to melt it, the curing reaction proceeds rapidly. Therefore, when the epoxy resin composition is melted and then molded in the mold, the epoxy resin composition is sufficiently contained in the mold. The melt viscosity of the epoxy resin composition rapidly increases before it is filled. Since the epoxy resin composition for encapsulating a semiconductor contains an inorganic filler, an increase in melt viscosity due to the progress of the curing reaction has a significant effect on moldability. Therefore, the epoxy resin composition tends to wash away the wiring of the semiconductor element during molding, and so-called weld voids are likely to occur due to the unfilling of the epoxy resin composition in the mold.

In order to ensure the fluidity of the epoxy resin composition during melting, it has also been proposed to use finely pulverized phosphonium salt particles as a curing accelerator (see Patent Documents 3 and 4). However, the finely pulverized phosphonium salt particles disclosed in Patent Documents 3 and 4 are difficult to dissolve and disperse in the epoxy resin composition, and therefore, for example, when sealing a semiconductor element in a flip chip package, the particles are fine. Insulation failure may be caused by particles getting caught in the gaps between the bumps.

Japanese Unexamined Patent Publication No. 2004-256634 Japanese Unexamined Patent Publication No. 2005-162944 Japanese Unexamined Patent Publication No. 2006-124643 Japanese Unexamined Patent Publication No. 2007-119710

An object of the present invention is an epoxy resin composition for sealing, which contains a phosphonium salt as a curing accelerator, has excellent dispersibility of the curing accelerator, and has excellent fluidity, curability, and storage stability. It is an object of the present invention to provide a cured product of an epoxy resin composition for sealing, and a semiconductor device sealed with a cured product of the epoxy resin composition for sealing.

The epoxy resin composition for sealing according to one aspect of the present invention is
Epoxy resin (A),
Hardener (B),
Curing accelerator (C) and inorganic filler (D)
Contains,
The curing accelerator (C) is a phosphonium salt (C2) composed of a quaternary phosphonium (C1) represented by the following formula (1) and an anion (C2) of an organic phenol compound (c21) represented by the following formula (2). It has CA) and an organic phenol compound (CC) represented by the following formula (3).

In the above formula (1), R1 to R3 are independently aryl groups having 6 to 12 carbon atoms, and R4 is an alkyl group having 1 to 8 carbon atoms or an aryl group having 6 to 12 carbon atoms.

In the above formula (2), R5 to R8 are independently hydrogen, an alkyl group having 1 to 4 carbon atoms or a hydroxyl group, and R9 is an alkyl group having 1 to 18 carbon atoms, an aryl group having 6 to 18 carbon atoms, and benzyl. Group, hydroxyalkyl group or allyl group.

In the above formula (3), R10 is an alkyl group having 1 to 18 carbon atoms or an aryl group having 6 to 18 carbon atoms, and R11 has 6 to 6 carbon atoms having a group represented by the following formula (4) as at least a part thereof. There are 50 atomic groups.

The cured product according to one aspect of the present invention is a cured product of the sealing epoxy resin composition.

The semiconductor device according to one aspect of the present invention includes a semiconductor element and a sealing material for sealing the semiconductor element, and the sealing material contains the cured product.

According to one aspect of the present invention, a sealing epoxy resin composition having excellent fluidity, curability and storage stability, a cured product of the sealing epoxy resin composition, and the sealing epoxy resin composition. A semiconductor device sealed with the cured product of is obtained.

The sealing epoxy resin composition according to one embodiment of the present invention contains an epoxy resin (A), a curing agent (B), a curing accelerator (C), and an inorganic filler (D).

The curing accelerator (C) contains a phosphonium salt (CA) and an organic phenol compound (CC).

The phosphonium salt (CA) is composed of a quaternary phosphonium (C1) represented by the following formula (1) and an anion (C2) of the organic phenol compound (c21) represented by the following formula (2).

In the formula (1), R1 to R3 are independently aryl groups having 6 to 12 carbon atoms, and R4 is an alkyl group having 1 to 8 carbon atoms or an aryl group having 6 to 12 carbon atoms.

In the formula (2), R5 to R8 are independently hydrogen, an alkyl group having 1 to 4 carbon atoms or a hydroxyl group, and R9 is an alkyl group having 1 to 18 carbon atoms, an aryl group having 6 to 18 carbon atoms, and a benzyl group. , Hydrokylalkyl group or allyl group.

The organic phenol compound (CC) is represented by the following formula (3).

In the formula (3), R10 is an alkyl group having 1 to 18 carbon atoms or an aryl group having 6 to 18 carbon atoms, and R11 has 6 to 50 carbon atoms having a group represented by the following formula (4) as at least a part thereof. Atomic group of.

In the present embodiment, since the curing accelerator (C) has a quaternary phosphonium (C1), the curing accelerator (C) can effectively accelerate the reaction between the epoxy resin (A) and the curing agent (B). .. Further, since the anion (C2) has an electron-withdrawing ester group, the acid strength of the anion (C2) is apparently strong. Furthermore, since each of the anion (C2) and the organic phenol compound (CC) has a hydroxyl group capable of hydrogen bonding, a hydrogen bond is formed between the anion (C2) and the organic phenol compound (CC), and thus an anion. The interaction between (C2) and the organic phenolic compound (CC) is strong, and the distance between the anion (C2) and the organic phenolic compound (CC) is short. Therefore, the anion (C2) is surrounded by the organic phenol compound (CC). Therefore, the nucleophilicity of the anion (C2) is suppressed. As a result, the activity of the phosphonium salt (CA) decreases at the temperature at which the sealing epoxy resin composition is melted to fill the mold during molding, so that the curing reaction of the epoxy resin (A) is suppressed. Also, the ester structure is flexible. Therefore, the fluidity of the sealing epoxy resin composition when the sealing epoxy resin composition is filled in the mold at the time of molding is excellent.

On the other hand, at a temperature at which the sealing epoxy resin composition is cured in the mold during molding, the hydrogen bond between each of the anion (CA) and the organic phenol compound (CC) is weakened, and the phosphonium salt (CA) is activated. To become. Therefore, the sealing epoxy resin composition has excellent curability.

Therefore, at the time of molding the sealing epoxy resin composition, when the sealing epoxy resin composition is melted to fill the mold, the sealing epoxy resin composition has excellent fluidity, and the sealing epoxy resin composition has excellent fluidity. When the resin composition is cured in the mold, the sealing epoxy resin composition is excellent in curability. Therefore, the sealing epoxy resin composition is suitable for producing a sealing material for electronic parts such as semiconductors.

The curing accelerator (C) will be described in more detail.

First, the quaternary phosphonium (C1) represented by the formula (1) will be described.

As described above, R1 to R3 in the formula (1) are independently aryl groups having 6 to 12 carbon atoms. Examples of aryl groups include phenyl groups, naphthyl groups, biphenyl groups, methylphenyl groups, ethylphenyl groups, propylphenyl groups, butylphenyl groups, methylnaphthyl groups, and ethylnaphthyl groups.

Each of R1 to R3 is a phenyl group, a methylphenyl group, or a naphthyl group because the fluidity of the sealing epoxy resin composition at the time of molding can be further improved and the raw material can be easily obtained. A phenyl group is preferable, and a phenyl group is particularly preferable.

As described above, R4 in the formula (1) is an alkyl group having 1 to 8 carbon atoms or an aryl group having 6 to 12 carbon atoms. Examples of alkyl groups are methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, neopentyl group, t. -Pentyl group, n-hexyl group, 1-methylpentyl group, 4-methyl-2-pentyl group, 3,3-dimethylbutyl group, 2-ethylbutyl group, n-heptyl group, 1-methylhexyl group, n- It contains an octyl group, a tert-octyl group, a 1-methylheptyl group, a 2-ethylhexyl group, and a 2-propylpentyl group. Examples of aryl groups include phenyl groups, naphthyl groups, biphenyl groups, methylphenyl groups, ethylphenyl groups, propylphenyl groups, butylphenyl groups, methylnaphthyl groups, and ethylnaphthyl groups.

R4 has an alkyl group having 1 to 4 carbon atoms or an alkyl number of carbon atoms because it can improve the curability of the sealing epoxy resin composition during molding and the synthesis of quaternary phosphonium (C1) becomes easier. It is preferably an aryl group of 6 to 12, more preferably a methyl group, an ethyl group or a phenyl group, and even more preferably a methyl group or an ethyl group.

Next, the anion (C2) of the organic phenol compound (c21) represented by the formula (2) will be described.

The anion (C2) contributes to the improvement of fluidity and curability of the sealing epoxy resin composition during molding.

As described above, R5 to R8 in the formula (2) are independently hydrogen, an alkyl group having 1 to 4 carbon atoms or a hydroxyl group, and R9 is an alkyl group having 1 to 18 carbon atoms and an aryl group having 6 to 18 carbon atoms. , A benzyl group, a hydroxyalkyl group or an allyl group, examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, and a tert-butyl group. ..

As described above, R9 in the formula (2) is an alkyl group having 1 to 18 carbon atoms, an aryl group having 6 to 18 carbon atoms, a benzyl group, a hydroxyalkyl group, or an allyl group. Examples of alkyl groups include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, It contains a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group and a heptadecyl group. Examples of aryl groups include phenyl group, naphthyl group, biphenyl group, methylphenyl group, ethylphenyl group, propylphenyl group, butylphenyl group, methylnaphthyl group and ethylnaphthyl group. Examples of hydroxyalkyl groups include hydroxymethyl groups, hydroxyethyl groups, hydroxypropyl groups and hydroxybutyl groups.

The anion (C2) preferably has a hydrogen bond. That is, it is preferable that a hydrogen bond is formed in the anion (C2). An example of the structure of the anion (C2) having a hydrogen bond is shown in the following formula (21). In this case, the nucleophilicity of the anion (C2) in the curing accelerator (C) is further suppressed, and therefore the fluidity of the sealing epoxy resin composition at the time of molding is further improved. In order for the anion (C2) to have a hydrogen bond, it is preferable that at least one of R5 and R6 in the formula (2) is a hydroxyl group, and it is also preferable that R5 and R8 are hydroxyl groups. It is particularly preferable that all of R5 to R8 are hydroxyl groups.

Next, the organic phenol compound (CC) represented by the formula (3) will be described.

The organic phenol compound (CC) interacts with the anion (C2) in the phosphonium salt (CA) to improve the fluidity and curability of the sealing epoxy resin composition during molding.

As described above, in the formula (3), R10 is an alkyl group having 1 to 18 carbon atoms or an aryl group having 6 to 18 carbon atoms, and R11 has a carbon number having a group represented by the formula (4) as at least a part thereof. It is an atomic group of 6 to 50.

It is preferable that R11 has only the group represented by the formula (4), that is, R11 is the group represented by the formula (4).

It is also preferable that R11 is a group represented by the following formula (6).

In formula (6), R12 and R13 are independently hydrogen, an alkyl group having 1 to 36 carbon atoms, or an aryl group having 6 to 36 carbon atoms, respectively.

In order to produce a good interaction between the organic phenol compound (CC) and the anion (C2), the molar ratio of the phosphonium salt (CA) to the organic phenol compound (CC) is 10: 90-99.9: It is preferably in the range of 0.1, more preferably in the range of 20:80 to 80:20, and even more preferably in the range of 30:70 to 70:30.

The curing accelerator (C) preferably further contains an organic phenol compound (CB) represented by the following formula (5).

In formula (5), R5 to R8 are independently hydrogen, an alkyl group having 1 to 4 carbon atoms or a hydroxyl group, and R9 is an alkyl group having 1 to 18 carbon atoms, an aryl group having 6 to 18 carbon atoms, and a benzyl group. , Hydrokylalkyl group or allyl group.

The organic phenol compound (CB) may have the same structure as the organic phenol compound (c21).

When the curing accelerator (C) has an organic phenol compound (CB), the organic phenol compound (CB) has a hydrogen-bondable hydroxyl group like the organic phenol compound (CC), so that the anion (C2) and the organic phenol compound A hydrogen bond is formed with (CB). Therefore, the interaction between the anion (C2) and the organic phenol compound (CB) is strong, and the distance between the anion (C2) and the organic phenol compound (CB) is short. Therefore, the anion (C2) is surrounded by the organic phenol compound (CC) and the organic phenol compound (CB). Therefore, the nucleophilicity of the anion (C2) is suppressed. Therefore, at the time of molding the sealing epoxy resin composition, when the sealing epoxy resin composition is melted to fill the mold, the sealing epoxy resin composition has excellent fluidity and is cured in the mold. The sealing epoxy resin composition is excellent in curability.

In order for the interaction between the organic phenol compound (CB) and the anion (C2) to occur well, the molar ratio of the phosphonium salt (CA) to the organic phenol compound (CB) is 10: 90-99.9: It is preferably in the range of 0.1, more preferably in the range of 20:80 to 80:20, and even more preferably in the range of 30:70 to 70:30.

A method for synthesizing the curing accelerator (C) will be described.

First, a phosphonium salt (CA) is synthesized. The phosphonium salt (CA) is synthesized, for example, by a salt exchange reaction between an alkyl carbonate (c11) or a hydroxide (c12) of a quaternary phosphonium (C1) and an organic phenol compound (c21).

The alkyl carbonate (c11) is synthesized, for example, by reacting the tertiary phosphine corresponding to the alkyl carbonate (c11) with carbonic acid diesters. Examples of tertiary phosphines include triphenylphosphine, tris (4-methylphenyl) phosphine, and 2- (diphenylphosphine) biphenyl. Examples of carbonate diesters include diethyl carbonate, dimethyl carbonate, dibutyl carbonate, and diphenyl carbonate. The reaction is carried out, for example, in an autoclave, and the reaction conditions are, for example, in the temperature range of 50 to 150 ° C. and in the time range of 10 to 200 hours. In order to complete the reaction quickly and in good yield, it is preferable to proceed the reaction in a solvent. Examples of solvents include methanol and ethanol.

The hydroxide (c12) is obtained by reacting, for example, a tertiary phosphine corresponding to the hydroxide (c12) with a halogenated (bromide or chloride) alkyl or a halogenated (bromide or chloride) aryl. The resulting product is obtained by salt exchange with an inorganic alkali. Examples of tertiary phosphines include triphenylphosphine, tris (4-methylphenyl) phosphine, and 2- (diphenylphosphine) biphenyl. Examples of alkyl halides include ethyl bromide, butyl chloride, 2-ethylhexyl bromide, 2-butylethanol, and 2-chloropropanol. Examples of aryl halides include bromobenzene, bromonaphthalene, and bromobiphenyl. Examples of inorganic alkalis include sodium hydroxide, potassium hydroxide, calcium hydroxide, barium hydroxide, and aluminum hydroxide. The reaction conditions are, for example, a temperature in the range of 20 to 150 ° C. and a time in the range of 1 to 20 hours. It is preferable to use a solvent in order to complete the reaction quickly and in good yield. Examples of solvents include methanol and ethanol.

In order to further improve the fluidity and curability of the sealing epoxy resin composition during molding, the molar ratio of the alkyl carbonate (c11) or hydroxide (c12) to the organic phenol compound (c21). Is preferably in the range of 10:90 to 90:10, and more preferably in the range of 20:80 to 80:20.

The salt exchange reaction between the alkyl carbonate (c11) or hydroxide (c12) and the organic phenol compound (c21) is carried out under the conditions of, for example, a temperature in the range of 30 to 170 ° C. and a time in the range of 1 to 20 hours. Will be done. During the salt exchange reaction, the by-products alcohol, water, carbon dioxide and, if necessary, the solvent are removed from the reaction system.

In particular, it is preferable to synthesize the phosphonium salt (CA) by a salt exchange reaction between the alkyl carbonate (c11) and the organic phenol compound (c21). In this case, it is possible to suppress the mixing of ionic impurities into the phosphonium salt (CA), which is a cause of deterioration of electrical reliability.

Next, the curing accelerator (C) is obtained by mixing and heating the phosphonium salt (CA), the organic phenol compound (CC), and if necessary, the organic phenol compound (CB).

When mixing the phosphonium salt (CA), the organic phenol compound (CB), and the organic phenol compound (CC), these components may be mixed at once, for example, the phosphonium salt (CA) and the organic phenol compound. (CB) may be mixed to prepare a mixture, and this mixture may be mixed with the organic phenol compound (CC). Further, when the organic phenol compound (c21) is blended for the salt exchange reaction between the alkyl carbonate (c11) or the hydroxide (c12) and the organic phenol compound (c21), the organic phenol compound (c21) is partially used. A mixture of a phosphonium salt (CA) and an organic phenol compound (CB) may be obtained by using an organic phenol compound containing an organic phenol compound (CB) as a balance. In other words, by using an amount of the organic phenol compound in excess of the required amount of the organic phenol compound (c21), a part of the organic phenol compound can be used as the organic phenol compound (c21) and the rest can be used as the organic phenol compound (CB). Good.

When mixing the phosphonium salt (CA), the organic phenol compound (CB), and the organic phenol compound (CC), these components are mixed at a temperature in the range of 50 to 200 ° C. and within a range of 1 to 20 hours. It is preferable to mix uniformly by stirring for the above time. A solvent may be used to complete the mixing quickly, in which case it is preferred to remove the solvent after mixing, for example under reduced pressure or at room temperature, at a temperature in the range of 50-200 ° C. Examples of solvents include metanol and ethanol.

The mixing ratio of the phosphonium salt (CA) and the organic phenol compound (CB) in synthesizing the curing accelerator (C) is the molar amount of the phosphonium salt (CA) and the organic phenol compound (CB) in the curing accelerator (C). The ratio is determined to be the desired value. The blending ratio of the phosphonium salt (CA) and the organic phenol compound (CC) was also determined so that the molar ratio of the phosphonium salt (CA) and the organic phenol compound (CC) in the curing accelerator (C) became a desired value. To.

In order for the curing accelerator (C) to be particularly easily dispersed and melted in the sealing epoxy resin composition, the melting point or softening point of the curing accelerator (C) is preferably 200 ° C. or lower, and is 70 to 70 to. It is more preferable if it is within the range of 150 ° C. When the melting point or the softening point is 150 ° C. or lower, the curing accelerator (C) is particularly easily dispersed and melted in the sealing epoxy resin composition. Further, when the melting point or the softening point is 70 ° C. or higher, fusion when the curing accelerator (C) is crushed into a powder is particularly suppressed, and the powdered curing accelerator (C) is stored during storage. ) Is hard to block. The melting point or softening point is more preferably in the range of 80 to 120 ° C., and particularly preferably in the range of 90 to 100 ° C.

In order to measure the melting point or softening point of the curing accelerator (C), the differential scanning calorimetry of the curing accelerator (C) is performed under the condition of a heating rate of 20 ° C./min in an air atmosphere. Obtain a DSC curve. The temperature at which the endothermic peak appears in this DSC curve is the melting point or softening point.

As a method for lowering the melting point or softening point of the curing accelerator (C), masterbatch of the curing accelerator (C) with a phenol resin can be mentioned. The phenol resin preferably has a low viscosity. Examples of phenolic resins include bisphenol A, bisphenol F, phenol novolac resin, cresol novolac resin, and phenol aralkyl resin. Known methods are available for masterbatch.

It is also preferable that the curing accelerator (C) is in the form of powder. In this case as well, the curing accelerator (C) becomes particularly easy to disperse and melt in the sealing epoxy resin composition. An example of a method of powdering the curing accelerator (C) is to pulverize the curing accelerator (C) with an impact crusher or the like. The powdery curing accelerator (C) is preferably 100 mesh pass 95% or more. That is, it is preferable that 95% by mass or more of the powdered curing accelerator (C) passes through 100 mesh (opening 212 μm). This 100 mesh pass is measured by the air jet sheave method. In this case, the curing accelerator (C) becomes very easy to disperse and melt in the sealing epoxy resin composition.

The curing accelerator (C) according to the present embodiment does not contain benzene, and benzene is not generated during the synthesis of the curing accelerator (C) and is not mixed with the curing accelerator (C). Therefore, the release of benzene derived from the curing accelerator from the sealing epoxy resin composition is suppressed.

Further, when the sealing epoxy resin composition is prepared by heating and kneading the component containing the curing accelerator (C), the curing accelerator (C) is dispersed and melted in the sealing epoxy resin composition. Cheap. Therefore, when the semiconductor element is sealed with the sealing epoxy resin composition, it is possible to prevent the particles of the curing accelerator (C) from being caught between the wires or between the bumps and causing insulation failure.

The halogen ion content, which is an impurity in the curing accelerator (C), is preferably 5 ppm or less with respect to the curing accelerator (C). In this case, migration in the sealing material produced from the sealing epoxy resin composition is particularly suppressed, and therefore the semiconductor device provided with the sealing material has particularly high reliability. Such a low halogen ion content can be achieved by synthesizing the curing accelerator (C) by a method including a salt exchange reaction as described above.

The amount of the curing accelerator (C) with respect to 100 parts by mass of the epoxy resin (A) is preferably in the range of 1 to 20 parts by mass. When the curing accelerator (C) is 1 part by mass or more, particularly excellent curability is imparted to the sealing epoxy resin composition. When the curing accelerator (C) is 20 parts by mass or less, a particularly excellent molding fluidity is imparted to the sealing epoxy resin composition. It is particularly preferable that the curing accelerator (C) is in the range of 7.7 to 15.2 parts by mass.

The sealing epoxy resin composition is referred to as a curing accelerator other than the curing accelerator (C) (hereinafter referred to as a second curing accelerator) in addition to the curing accelerator (C) within a range not deviating from the object of the present embodiment. ) May be contained. For example, the epoxy resin composition for encapsulation contains triarylphosphines, tetraphenylphosphonium / tetraphenylborate, imidazoles such as 2-methylimidazole, and 1,8-diazabicyclo (5,4) as the second curing accelerator. 0) It can contain at least one component selected from the group consisting of Undecene-7. The amount of the second curing accelerator is preferably 50% by mass or less with respect to the total of the curing accelerator (C) and the second curing accelerator.

The components other than the curing accelerator (C) in the sealing epoxy resin composition will be described.

The epoxy resin (A) is a compound having two or more epoxy groups in one molecule. The epoxy resin (A) contains at least one component selected from the group consisting of, for example, bisphenol A type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, biphenyl type epoxy resin, and triphenylmethane type epoxy resin. Can contain. In particular, when the epoxy resin (A) contains at least one of a biphenyl type epoxy resin and a low moisture absorption type epoxy resin having a phenyl ring to which a lower alkyl group is added, the reliability of the semiconductor device is improved. It is preferable for this. The epoxy equivalent of the epoxy resin (A) is preferably in the range of 150 to 290. The softening point or melting point of the epoxy resin (A) is preferably in the range of 50 to 130 ° C.

The curing agent (B) is a curing agent for the epoxy resin (A). The curing agent (B) preferably contains at least one component selected from the group consisting of a phenol compound, an acid anhydride, and a functional compound that produces a phenolic hydroxyl group. In particular, when the curing agent (B) contains at least one of a phenol compound and a functional compound, a sealing material made from a sealing epoxy resin composition is imparted with extremely high moisture resistance reliability.

The phenolic compound may include monomers, oligomers and polymers having two or more phenolic hydroxyl groups in one molecule. For example, the curing agent (B) is at least one component selected from the group consisting of phenol novolac resin, cresol novolac resin, biphenyl type novolak resin, triphenylmethane type resin, naphthol novolac resin, phenol aralkyl resin, and biphenyl aralkyl resin. Can be contained. In particular, it is preferable that the curing agent (B) contains at least one of a low hygroscopic phenol aralkyl resin and a biphenyl aralkyl resin in order to improve the reliability of the semiconductor device. When the curing agent (B) is a phenol compound, the hydroxyl group equivalent of the phenol compound with respect to 1 equivalent of the epoxy group of the epoxy resin (A) is preferably in the range of 0.5 to 2.0, preferably 0.8. It is more preferable if it is within the range of ~ 1.4.

Acid anhydrides include, for example, phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride, benzophenone tetracarboxylic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, and methyltetrahydrophthalic anhydride. It can contain at least one component selected from the group consisting of phthalic anhydride and polyazelineic anhydride. When the curing agent (B) is an acid anhydride, the acid anhydride per epoxy group equivalent of the epoxy resin (A) is preferably in the range of 0.7 to 1.5 equivalents, preferably 0.8 to 1.5 equivalents. It is more preferable if it is within the range of 1.2 equivalents.

Examples of the functional compound that produces a phenolic hydroxyl group include a compound that produces a phenolic hydroxyl group when heated. More specifically, examples of the functional compound include benzoxazines that open the ring when heated to generate a phenolic hydroxyl group.

The inorganic filler (D) can generally contain a material to be blended in the epoxy resin composition without particular limitation. For example, the inorganic filler (D) is molten silica, spherical silica, spherical molten silica, crushed silica, crystalline silica, spherical alumina, magnesium oxide, boron nitride, aluminum hydroxide and the like; high dielectric constant fillers such as barium titanate and titanium oxide. Magnetic fillers such as hard ferrite; Inorganic flame retardants such as magnesium hydroxide, aluminum hydroxide, antimony trioxide, antimony pentoxide, guanidine salts, zinc borate, molybdenum compounds, zinc stannate; and talc, barium sulfate , Calcium carbonate, mica powder and the like, and can contain at least one component selected from the group. In particular, the inorganic filler (D) preferably contains spherical molten silica. The average particle size of the inorganic filler (D) is preferably in the range of 3 to 40 μm, and in this case, the fluidity of the sealing epoxy resin composition at the time of molding is particularly good. The average particle size is measured by a laser diffraction / scattering type particle size distribution measuring device.

The inorganic filler (D) is preferably in the range of 70 to 95% by mass with respect to the entire sealing epoxy resin composition. When the content of the inorganic filler (D) is 95% by mass or less, the fluidity of the sealing epoxy resin composition at the time of molding is particularly excellent, and defects such as wire flow and unfilling are suppressed. When the inorganic filler (D) is 70% by mass or more, the melt viscosity of the sealing epoxy resin composition during molding is suppressed from becoming excessively high, so that the sealing epoxy resin composition is formed from the sealing epoxy resin composition. Poor appearance due to voids in the sealing material to be formed is suppressed. It is particularly preferable that the inorganic filler (D) is in the range of 85 to 92% by mass with respect to the entire sealing epoxy resin composition.

In addition to the above components (A) to (D), the sealing epoxy resin composition contains a silane coupling agent, a flame retardant, a flame retardant aid, a mold release agent, an ion trap agent, a pigment such as carbon black, and coloring. Additives such as agents, low stress agents, tackifiers, silicone flexible agents and the like may be included.

The silane coupling agent preferably has two or more alkoxy groups. Examples of the silane coupling agent include β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-mercaptopropyltrimethoxy. At least one component selected from the group consisting of silane, γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-anilinopropyltrimethoxysilane, and hexamethyldisilazane. Can be contained.

The flame retardant can contain a novolak type brominated epoxy resin, a metal hydroxide and the like. In particular, the flame retardant preferably contains at least one of diantimony trioxide and diantimony pentoxide.

The release agent can contain higher fatty acid, higher fatty acid ester, higher fatty acid calcium and the like. For example, the release agent can contain at least one of carnauba wax and polyethylene wax.

The ion trapping agent can contain a known compound having an ion trapping ability. For example, the ion trap agent can contain hydrotalcites, bismuth hydroxide and the like.

Examples of the low stressing agent include butadiene rubbers such as methyl acrylate-butadiene-styrene copolymer, methyl methacrylate-butadiene-styrene copolymer, and silicone compounds.

A method for producing an epoxy resin composition for encapsulation will be described. Epoxy resin (A), curing agent (B), curing accelerator (C), inorganic filler (D), and if necessary, additives are mixed, and then heated using a kneader such as a hot roll or kneader. The epoxy resin composition for encapsulation in powder form can be obtained by melting and mixing with the above, then cooling to room temperature, and further pulverizing by a known means. By tableting this powdery sealing epoxy resin composition, a tablet-shaped sealing epoxy resin composition having dimensions and mass suitable for molding conditions may be obtained.

The cured product of the epoxy resin composition for encapsulation is suitable as a encapsulant for encapsulating a semiconductor chip in a semiconductor device. A semiconductor device including a sealing material will be described.

The semiconductor device includes a semiconductor chip such as an IC chip and a sealing material for sealing the semiconductor chip. The encapsulant is a cured product of the epoxy resin composition for encapsulation. The semiconductor device may further include a base material that supports the semiconductor chip. The base material is, for example, a lead frame, a wiring board, or the like. The encapsulant can be produced by a known molding method such as a transfer molding method, a compression molding method, or an injection molding method.

When manufacturing a semiconductor device, for example, a semiconductor chip is first mounted on a base material. The semiconductor chip is electrically connected to the base material by a method such as flip chip bonding or wire bonding. The base material on which this semiconductor chip is mounted is set in a mold for transfer molding. In this state, the sealing epoxy resin composition is heated and melted, then the sealing epoxy resin composition is injected into a mold, and the sealing epoxy resin composition is further heated in the mold. .. As a result, the sealing epoxy resin composition is thermoset to form a sealing material that covers the semiconductor chip.

When the encapsulant is produced by the transfer molding method, for example, the mold temperature is in the range of 160 to 185 ° C., and the molding time is in the range of 60 to 120 seconds. The molding conditions may be appropriately changed depending on the composition of the sealing epoxy resin composition and the like.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

[Preparation of epoxy resin composition for encapsulation]
In each Example and Comparative Example, the inorganic filler was surface-treated with a silane coupling agent. A mixture was obtained by sufficiently mixing the treated inorganic filler, curing accelerator, epoxy resin, phenol compound, mold release agent, and colorant with a mixer. This mixture is melt-kneaded with a twin-screw roll at a set temperature of 100 ° C. for 5 minutes, cooled, crushed with a crusher, and then locked to obtain a tablet-shaped epoxy resin composition for encapsulation. It was.

The components used in each Example and Comparative Example and their amounts are as shown in the table below. In the table, the amount of the component is shown by mass. Details of these components are as shown below.
-Curing accelerator 1: Panasonic Corporation, a reaction product of TPP-K and phenol novolac resin.
-Curing accelerator 2: TPP-K manufactured by Hokuko Chemical Industry Co., Ltd.
-Curing accelerator 3: MeTPP-Methyl Galate manufactured by Sun Appro Co., Ltd.
-Curing accelerator 4: MeTPP-Methyl Galate-VGTP manufactured by Sun Appro Co., Ltd.
-Curing accelerator 5: MeTPP-Ethyl Gallate-VGTP manufactured by Sun Appro Co., Ltd.
-Curing accelerator 6: MeTPP-Propyl Galate-VGTP manufactured by Sun Appro Co., Ltd.
-Curing accelerator 7: manufactured by Sun Appro Co., Ltd .: MeTPP-4,4'-Dihydroxybenzophenone-1,1,1-Tris (4-hydroxyphenyl) ethane.
-Curing accelerator 8: manufactured by Sun Appro Co., Ltd .: MeTPP-methyl salicylate-1,1,1-Tris (4-hydroxyphenyl) ethane.
-Curing accelerator 9: manufactured by Sun Appro Co., Ltd .: MeTPP-catechol-1,1,1-Tris (4-hydroxyphenyl) ethane.
Curing Accelerator 10: MeTPP-4-butylparaben-1,1,1-Tris (4-hydroxyphenyl) ethane, manufactured by Sun Appro Co., Ltd.
-Curing Accelerator 11: MeTPP-4-phenyl4-hyodoroxybenzoate-4,4', 4 "-trihydroxytriphenylmethane, manufactured by Sun Appro Co., Ltd.
Curing Accelerator 12: MeTPP-Methyl β-Resorcylate-VGTP manufactured by Sun Appro Co., Ltd.
-Epoxy resin: Tetramethylbiphenyl type epoxy resin manufactured by Mitsubishi Chemical Corporation, product number YX4000H.
-Phenolic compound: Biphenyl aralkyl type phenol resin manufactured by Meiwa Kasei Co., Ltd., product number MEH7851SS.
-Release agent: Carnauba wax manufactured by Dainichi Chemical Industry Co., Ltd., product number F1-100.
-Coupling agent: 3γ-mercaptopropyltrimethoxysilane manufactured by Shinetsu Silicone Co., Ltd., product number KBM-803.
-Colorant: Mitsubishi Chemical Corporation, carbon black, product number MA600.
-Inorganic filler: Denki Kagaku Kogyo Co., Ltd., spherical fused silica, product number FB5SDC.

Further details of the curing accelerators shown in the table will be described.

(Curing accelerator 1)
The curing accelerator 1 heats TPP-K and a low-viscosity phenol novolac resin (Meiwa Kasei Kogyo Co., Ltd., product number H-4) at 170 to 180 ° C. in a nitrogen atmosphere to cool the obtained product. It is a compound having a phosphonium cation concentration of 10% by mass, which is obtained by pulverizing the mixture.

(Curing accelerator 2)
The curing accelerator 2 is a commercially available tetraphenylphosphonium tetraphenylborate (TPP-K) manufactured by Hokuko Chemical Industry Co., Ltd.

(Curing accelerator 3)
The curing accelerator 3 is a phosphonium salt represented by the following formula (7), which is synthesized by a method including a salt exchange reaction between an alkyl carbonate of a quaternary phosphonium and phenols.

(Curing accelerator 4)
The curing accelerator 4 is a phosphonium salt represented by the following formula (8), which is synthesized by a method including a salt exchange reaction between an alkyl carbonate of a quaternary phosphonium and phenols.

(Curing accelerator 5)
The curing accelerator 5 is a phosphonium salt represented by the following formula (9), which is synthesized by a method including a salt exchange reaction between an alkyl carbonate of a quaternary phosphonium and phenols.

(Curing accelerator 6)
The curing accelerator 6 is a phosphonium salt represented by the following formula (10), which is synthesized by a method including a salt exchange reaction between an alkyl carbonate of a quaternary phosphonium and phenols.

(Curing accelerator 10)
The curing accelerator 10 was synthesized by the following method.

180 parts by mass of dimethyl carbonate (manufactured by Tokyo Chemical Industry Co., Ltd.) and 224 parts by mass of methanol as a solvent were placed in a stirring type autoclave. After further adding 262 parts by mass of triphenylphosphine (manufactured by Tokyo Chemical Industry Co., Ltd.) in the autoclave, the contents of the autoclave were heated at 125 ° C. for 80 hours to allow the reaction to proceed. Subsequently, 120 parts by mass of methanol was removed from the autoclave under reduced pressure, and then 1200 parts by mass of toluene was placed in the autoclave to precipitate crystals. By isolating the crystals and then dissolving them in methanol, a solution of triphenylmethylphosphonium monomethyl carbonate (solid content concentration: 50%) was obtained as a quaternary phosphonium base (A-Be1).

704 parts by mass of a quaternary phosphonium base (A-Be1) was placed in a glass round-bottomed three-necked flask equipped with a dropping funnel and a reflux tube. While maintaining the temperature of the quaternary phosphonium base (A-Be1) at 50 ° C., 400 parts by mass of butyl 4-hydroxybenzoate (manufactured by Tokyo Chemical Industry Co., Ltd.) was divided and charged into a round-bottomed three-necked flask. .. Subsequently, 305 parts by mass of 1,1,1-tris (4-hydroxyphenyl) ethane (manufactured by Tokyo Chemical Industry Co., Ltd.) was placed in a round-bottomed three-necked flask. Subsequently, the contents of the round-bottomed three-necked flask were heated to 175 ° C. while distilling off the solvent (methanol) from the round-bottomed three-necked flask, and then the solvent remaining in the round-bottomed three-necked flask was removed. The curing accelerator 10 was obtained by removing under reduced pressure.

The molar ratio of the phosphonium salt (CA), the organic phenol compound (CB) and the organic phenol compound (CC) in the curing accelerator 10 was 1.00: 1.06: 1.00.

(Curing Accelerator 11)
The curing accelerator 11 was synthesized by the following method.

In the method for synthesizing the curing accelerator 10, 400 parts by mass of butyl 4-hydroxybenzoate was changed to 400 parts by mass of phenyl 4-hydroxybenzoate (manufactured by Tokyo Kasei Kogyo Co., Ltd.), and 1,1,1-tris (4) 305 parts by mass of -hydroxyphenyl) ethane was changed to 305 parts by mass of 4,4', 4 "-trihydroxytriphenylmethane (manufactured by Tokyo Kasei Kogyo Co., Ltd.). Other than that, the method for synthesizing the curing accelerator 10 was changed. It was adopted to obtain a curing accelerator 11.

The molar ratio of the phosphonium salt (CA), the organic phenol compound (CB) and the organic phenol compound (CC) in the curing accelerator 11 was 1.00: 0.87: 1.05.

(Curing Accelerator 12)
The curing accelerator 12 was synthesized by the following method.

419 parts by mass of tetraphenylphosphonium bromide (manufactured by Tokyo Chemical Industry Co., Ltd.) and 1000 parts by mass of methanol are placed in a glass round-bottomed three-necked flask equipped with a dropping funnel and a reflux tube, and tetraphenylphosphonium bromide is placed. Was uniformly dissolved in methanol. Subsequently, 40 parts by mass of sodium hydroxide was slowly placed in the round-bottomed three-necked flask, and then the contents of the round-bottomed three-necked flask were allowed to stand at room temperature for 5 hours. By removing the precipitated salt from the round-bottomed three-necked flask, a tetraphenylphosphonium hydroxide solution (solid content concentration 25%) was obtained as a quaternary phosphonium base (A-Be3).

In the method for synthesizing the curing accelerator 10, 704 parts of the quaternary phosphonium base (A-Be1) was changed to 1200 parts by mass of the quaternary phosphonium base (A-Be3), and butyl 4-hydroxybenzoate was added to 2, Methyl 4-dihydroxybenzoate (manufactured by Tokyo Kasei Kogyo Co., Ltd.) was changed to 400 parts by mass, and 305 parts by mass of 1,1,1-tris (4-hydroxyphenyl) ethane was changed to α, α, α'-tris (4). -Hydroxyphenyl) -1-ethyl-4-isopropylbenzene (manufactured by Tokyo Kasei Kogyo Co., Ltd.) 305 parts by mass. Other than that, the method for synthesizing the curing accelerator 10 was adopted to obtain the curing accelerator 12.

The molar ratio of the phosphonium salt (CA), the organic phenol compound (CB) and the organic phenol compound (CC) in the curing accelerator 12 was 1.00: 1.38: 0.71.

(Curing accelerator 7)
In the method for synthesizing the curing accelerator 10, butyl 4-hydroxybenzoate was changed to 400 parts by mass of 4,4'-dihydroxybenzophenone (manufactured by Tokyo Chemical Industry Co., Ltd.). Other than that, the method for synthesizing the curing accelerator 10 was adopted to obtain the curing accelerator 7.

(Curing accelerator 8)
In the method for synthesizing the curing accelerator 10, butyl 4-hydroxybenzoate was changed to methyl salicylate (manufactured by Tokyo Chemical Industry Co., Ltd.). Other than that, the method for synthesizing the curing accelerator 10 was adopted to obtain the curing accelerator 8.

(Curing accelerator 9)
In the method for synthesizing the curing accelerator 10, butyl 4-hydroxybenzoate was changed to catechol (manufactured by Tokyo Chemical Industry Co., Ltd.). Other than that, the method for synthesizing the curing accelerator 10 was adopted to obtain the curing accelerator 9.

[Impurity ion analysis]
Extracted water was obtained by putting the curing accelerators 1, 3 to 13 in hot water at 95 ° C. and holding the mixture for 15 hours. Ion chromatographic analysis of this extracted water was performed. Based on the results, the content ratios of chloride ion, bromide ion, sulfate ion and sodium ion in each curing accelerator were calculated. The case where the ion could not be detected due to the detection limit was defined as ND.

[Spiral flow length]
Using a transfer press ETA-D type manufactured by Shinto Kinzoku Kogyo Co., Ltd. and a spiral flow measurement die according to ASTMD3123, the spiral flow length of the sealing epoxy resin composition immediately after production in each Example and Comparative Example. The measurement was carried out under the conditions of a mold temperature of 175 ° C., an injection pressure of 6.9 MPa, and a molding time of 120 seconds. It can be evaluated that the longer the spiral flow length, the better the fluidity.

[Gel time evaluation]
The gel time of the sealing epoxy resin composition obtained in each Example and Comparative Example at 170 ° C. was measured. The measurement was performed using a curast meter manufactured by JSR Corporation. The gel time in this evaluation test is the time required from the start of measurement until the torque reaches 9.81 mN · m (0.1 kgf · cm). It can be evaluated that the shorter the gel time, the better the curability.

[Torque evaluation after 90 seconds]
When measuring the gel time, the torque value 90 seconds after the start of the measurement was measured. It can be evaluated that the larger this value is, the better the curability of the sealing epoxy resin composition is.

[Dispersibility evaluation]
The epoxy resin composition for encapsulation obtained in each Example and Comparative Example was molded into a tablet having a size of 13 mm in diameter and 20 mm in thickness, and one surface of this tablet was polished 8 times by 2 mm. The polished surface was observed with a metallurgical microscope after each polishing. As a result, the case where the agglutination of the curing accelerator was never observed on the polished surface was evaluated as "good", and the case where the agglutination of the curing accelerator was observed even once on the polished surface was evaluated as "poor".

[Storage stability]
The sealing epoxy resin compositions in each Example and Comparative Example were left at a temperature of 25 ° C. for 96 hours, and then the spiral flow length of the sealing epoxy resin composition was measured. The percentage of the spiral flow length after being left to stand with respect to the spiral flow length immediately after production was used as an index of storage stability. It can be evaluated that the larger the percentage, the higher the storage stability.

[Evaluation of benzene generation before curing]
The epoxy resin composition for sealing in each Example and Comparative Example is heated at 90 ° C. for 30 minutes in a sealed container, then the gas in the sealed container is sampled, and the amount of benzene in this gas is measured by headspace GC / MS. Measured by method.

[Evaluation of benzene generation after curing]
The epoxy resin compositions for encapsulation in each Example and Comparative Example were thermoset by heating at 175 ° C. for 6 hours. The cured product thus obtained was heated at 90 ° C. for 30 minutes in a sealed container, and then the gas in the sealed container was sampled, and the amount of benzene in this gas was measured by the headspace GC / MS method.

[Evaluation of continuous moldability]
With the substrate having a size of 40 mm × 40 mm set in the mold of a molding machine (product name S. Pot) manufactured by Daiichi Seiko, the epoxy resin composition for sealing in each Example and Comparative Example was molded at a molding temperature of 175. A molded product was formed on the substrate by molding under the conditions of ° C. and a cure time of 100 seconds. Immediately after that, the molded product was removed from the mold by lifting the substrate from the mold. At this time, the force required to lift the substrate from the mold was measured with a digital force gauge (manufactured by IMADA). This operation was repeated 100 times, and the average value of the values measured by the digital force gauge was calculated for each of the 1st to 25th, 26th to 50th, 51st to 75th, and 76th to 100th moldings.

According to the above results, in Examples 1 to 9, impurities in the curing accelerator were small, the fluidity and curability of the sealing epoxy resin composition were excellent, the dispersibility of the curing accelerator was good, and storage was performed. The stability was also good.

On the other hand, in Comparative Example 1, a known TPPK-PN resin MB was used as a curing accelerator. As a result, benzene is not generated after curing, but benzene derived from the reaction is generated from the epoxy resin composition before curing when heated. Therefore, the working environment is deteriorated.

In Comparative Example 2, a known TPPK was used as a curing accelerator. As a result, the gel time exceeds 100 seconds, which leads to deterioration of productivity. Aggregation of the curing accelerator in the composition also occurs. Further, a considerable amount of benzene is generated both before and after curing, which causes deterioration of the working environment.

In Comparative Example 3, MeTPP-Methyl Galate was used as a curing accelerator. As a result, the fluidity is excellent, but the torque is low after 90 seconds, so that it is judged to be inferior in curability.

In Comparative Example 4, MeTPP-4,4'-Dihydroxybenzophenone-1,1,1-Tris (4-hydroxyphenyl) ethane was used as a curing accelerator. As a result, the curability is good, but the fluidity is poor.

In Comparative Example 5, MeTPP-methyl salicylate-1,1,1-Tris (4-hydroxyphenyl) ethane was used as a curing accelerator. As a result, both fluidity and curability were inferior.

In Comparative Example 6, MeTPP-catechol-1,1,1-Tris (4-hydroxyphenyl) ethane was used as a curing accelerator. As a result, both fluidity and curability were inferior.

Further, since Examples 1 to 9 have excellent curability, continuous moldability is good. On the other hand, since Comparative Examples 1 and 3 to 6 had poor curability, the continuous moldability deteriorated as the number of moldings increased.

Claims (14)

Epoxy resin (A),
Hardener (B),
Curing accelerator (C) and inorganic filler (D),
Contains,
The curing accelerator (C) is a phosphonium salt (C2) composed of a quaternary phosphonium (C1) represented by the following formula (1) and an anion (C2) of an organic phenol compound (c21) represented by the following formula (2). CA) and an organic phenol compound (CC) represented by the following formula (3).
Epoxy resin composition for sealing,

In the above formula (1), R1 to R3 are independently aryl groups having 6 to 12 carbon atoms, and R4 is an alkyl group having 1 to 8 carbon atoms or an aryl group having 6 to 12 carbon atoms.

In the above formula (2), R5 to R8 are independently hydrogen, an alkyl group having 1 to 4 carbon atoms or a hydroxyl group, and R9 is an alkyl group having 1 to 18 carbon atoms, an aryl group having 6 to 18 carbon atoms, and benzyl. Group, hydroxyalkyl group or allyl group,

In the above formula (3), R10 is an alkyl group having 1 to 18 carbon atoms or an aryl group having 6 to 18 carbon atoms, and R11 has 6 to 6 carbon atoms having a group represented by the following formula (4) as at least a part thereof. There are 50 atomic groups.

The curing accelerator (C) further has an organic phenol compound (CB) represented by the following formula (5).
The epoxy resin composition for sealing according to claim 1.

In the above formula (5), R5 to R8 are independently hydrogen, an alkyl group having 1 to 4 carbon atoms or a hydroxyl group, and R9 is an alkyl group having 1 to 18 carbon atoms, an aryl group having 6 to 18 carbon atoms, and benzyl. Group, hydroxyalkyl group or allyl group. The molar ratio of the phosphonium salt (CA) to the organic phenol compound (CB) is in the range of 99; 1 to 1:99.
The epoxy resin composition for sealing according to claim 2. The molar ratio of the phosphonium salt (CA) to the organic phenol compound (CC) is in the range of 99: 1 to 1:99.
The epoxy resin composition for sealing according to any one of claims 1 to 3. In the above formula (2), R5 is a hydroxyl group, and R6 to R8 are independently hydrogens or hydroxyl groups, respectively.
The epoxy resin composition for sealing according to any one of claims 1 to 4. In the above formula (2), R5 is a hydroxyl group, R6 and R7 are hydrogen, and R8 is a hydroxyl group.
The epoxy resin composition for sealing according to any one of claims 1 to 4. In the above formula (2), R6 is a hydroxyl group, and R5, R7 and R8 are independently hydrogens or hydroxyl groups, respectively.
The epoxy resin composition for sealing according to any one of claims 1 to 4. In the above formula (2), R6 is a hydroxyl group, and R5, R7 and R8 are hydrogen, respectively.
The epoxy resin composition for sealing according to any one of claims 1 to 4. In the above formula (2), R9 is a methyl group, an ethyl group, a propyl group or a butyl group.
The epoxy resin composition for sealing according to any one of claims 1 to 8. In the above formula ( 3 ), R11 is a group represented by the above formula ( 4).
The epoxy resin composition for sealing according to any one of claims 1 to 9. In the above formula (3), R11 is a group represented by the following formula (6).
The epoxy resin composition for sealing according to any one of claims 1 to 9.

In the above formula (6), R12 and R13 are independently hydrogen, an alkyl group having 1 to 36 carbon atoms, or an aryl group having 6 to 36 carbon atoms, respectively. The curing agent (B) contains at least one of a phenol compound and a functional compound that produces a phenolic hydroxyl group.
The epoxy resin composition for sealing according to any one of claims 1 to 11. The cured product of the epoxy resin composition for sealing according to any one of claims 1 to 12. A semiconductor element and a sealing material for sealing the semiconductor element are provided, and the sealing material contains the cured product according to claim 13.
Semiconductor device.