JP6827210B2 - Epoxy resin composition for encapsulation and method for manufacturing semiconductor devices - Google Patents

Description

The present invention relates to an epoxy resin composition for encapsulation and a method for manufacturing a semiconductor device. Specifically, the present invention relates to an epoxy resin composition for encapsulation that can be used for encapsulating a semiconductor element by a compression molding method, and for encapsulation thereof. The present invention relates to a method for manufacturing a semiconductor device using an epoxy resin composition.

Conventionally, semiconductor elements such as transistors, ICs, and LSIs are resin-sealed in order to improve productivity and reduce costs.

As a resin sealing method, a compression molding method capable of narrowing the pitch, thinning the wire, and lengthening the gold wire is attracting attention. In this compression molding method, the resin composition for sealing is placed on a mold and heated, and the molten resin composition is slowly pressed against a substrate to apply pressure to cure the resin composition for sealing. The material is molded (see, for example, Patent Document 1).

Examples of the resin composition used for this resin encapsulation include an epoxy resin composition containing an epoxy resin, a curing agent, a curing accelerator, and an inorganic filler. The epoxy resin composition used in the transfer molding method is generally in the form of tablets, while the epoxy resin composition used in the compression molding method is generally in the form of particles.

Japanese Unexamined Patent Publication No. 2013-203928

When a sealing material is produced by molding an epoxy resin composition by a compression molding method, the epoxy resin composition is required to have high fluidity during molding in order to suppress unfilling of the sealing material. In order to improve the fluidity during molding, the epoxy resin composition may contain an epoxy resin having a low melt viscosity and a curing agent. However, when the fluidity of the epoxy resin composition is improved, there is a problem that the particles of the epoxy resin composition are easily fixed (blocked) to form a lump. In the compression molding method, the epoxy resin composition is weighed before being placed on the mold, but when a lump is formed, the epoxy resin composition may not be accurately weighed due to the lump. In addition, the lumps arranged in the mold may hinder heat conduction to the epoxy resin composition, and a part of the epoxy resin composition may not be completely melted. The lumps may cause deformation of the wire. Unfilling of the sealing material may occur. As described above, in the particulate epoxy resin composition used in the compression molding method, there is a trade-off relationship between improvement of fluidity during molding and suppression of blocking, and it is difficult to achieve both of these. there were.

In order to solve this problem, the inventor compounded tetraphenylphosphonium / tetraphenylborate (hereinafter referred to as TPP-K) as a curing accelerator to form an epoxy resin composition without deteriorating blocking resistance. We considered improving the fluidity of time. However, as a result of the study of the inventor, when TPP-K is contained in the particulate epoxy resin composition used in the compression molding method, benzene is significantly released from the epoxy resin composition during molding of the epoxy resin composition. Therefore, it was found that it causes problems such as deterioration of the working environment. This is because TPP-K contains benzene due to its manufacturing method and the epoxy resin composition is granular, and its specific surface area is large, so that benzene is easily released when the epoxy resin composition is heated. It is believed that there is.

The present invention provides a sealing epoxy resin composition capable of both improving fluidity during molding and suppressing blocking, and suppressing the release of benzene during molding, and the sealing epoxy resin composition. An object of the present invention is to provide a method for manufacturing a semiconductor device to be used.

The sealing epoxy resin composition according to one aspect of the present invention is in the form of particles containing an epoxy resin (A), a curing agent (B), a phosphonium salt (C), and an inorganic filler (D). It is an epoxy resin composition for sealing. This phosphonium salt (C) has a structure represented by the following formula (1).

In the formula (1), R ^{1 to} R ³ are independently aryl groups having 6 to 12 carbon atoms. R ⁴ is an alkyl group having 1 to ⁴ carbon atoms. R ⁶ and R ⁸ are independently carboxyl groups or hydroxyl groups, respectively. R ⁵ and R ⁷ are H or alkyl groups having 1 to 4 carbon atoms, respectively. Each of R ⁹ and R ¹¹ is H. R ¹⁰ is a carboxyl group or a hydroxyl group. p, q and r are numbers that satisfy the relationship of p ≧ 1, q ≧ 1, r ≧ 1, and q ≧ r. The amount of the inorganic filler (D) with respect to the sealing epoxy resin composition is in the range of 70 to 95% by mass.

A method for manufacturing a 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 above sealing epoxy resin composition is molded by a compression molding method. The step of producing the sealing material is included.

According to the present invention, it is possible to provide an epoxy resin composition for sealing, which can achieve both improvement of fluidity during molding and suppression of blocking, and can suppress release of benzene during molding.

1A to 1E are schematic cross-sectional views showing each step of the method for manufacturing a semiconductor device according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view showing a semiconductor device manufactured by the method for manufacturing a semiconductor device according to an embodiment of the present invention.

Hereinafter, an embodiment of the present invention will be described.

The sealing epoxy resin composition (hereinafter, also referred to as composition (X)) according to the present embodiment is in the form of particles, and contains an epoxy resin (A), a curing agent (B), and a phosphonium salt (C). , Inorganic filler (D). This phosphonium salt (C) has a structure represented by the following formula (1).

In the formula (1), R ^{1 to} R ³ are independently aryl groups having 6 to 12 carbon atoms. R ⁴ is an alkyl group having 1 to ⁴ carbon atoms. R ⁶ and R ⁸ are independently carboxyl groups or hydroxyl groups, respectively. R ⁵ and R ⁷ are H or alkyl groups having 1 to 4 carbon atoms, respectively. Each of R ⁹ and R ¹¹ is H. R ¹⁰ is a carboxyl group or a hydroxyl group. p, q and r are numbers that satisfy the relationship of p ≧ 1, q ≧ 1, r ≧ 1, and q ≧ r.

Further, the amount of the inorganic filler (D) with respect to the composition (X) is in the range of 70 to 95% by mass.

In the present embodiment, the composition (X) contains the phosphonium salt (C) to improve the fluidity of the composition (X) during molding and suppress the blocking of particles of the composition (X). , Can be compatible. Further, when the composition (X) contains the phosphonium salt (C), the release of benzene during molding of the composition (X) can be suppressed, and the deterioration of the working environment due to benzene can be suppressed. Further, when the amount of the inorganic filler (D) with respect to the composition (X) is in the range of 70 to 95% by mass, the blocking of particles of the composition (X) can be further suppressed.

The composition of the composition (X) will be described in more detail.

The epoxy compound (A) will be described. The epoxy compound (A) can contain a known and commonly used epoxy resin used in the production of a sealing material. The epoxy compound (A) is an alkylphenol novolac type epoxy resin such as a phenol novolac type epoxy resin or a cresol novolac type epoxy resin; a naphthol novolac type epoxy resin; a phenol aralkyl type epoxy resin having a skeleton such as a phenylene skeleton or a biphenylene skeleton; a biphenyl aralkyl type. Epoxy resin; naphthol aralkyl type epoxy resin having a skeleton such as phenylene skeleton and biphenylene skeleton; polyfunctional epoxy resin such as triphenol methane type epoxy resin and alkyl modified triphenol methane type epoxy resin; triphenyl methane type epoxy resin; tetrakisphenol ethane Type epoxy resin; Dicyclopentadiene type epoxy resin; Stilben type epoxy resin; Bisphenol A type epoxy resin, Bisphenol F type epoxy resin and other bisphenol type epoxy resin; Biphenyl type epoxy resin; Naphthalene type epoxy resin; Alicyclic epoxy resin; Bisphenol Brom-containing epoxy resins such as A-type brom-containing epoxy resins; glycidylamine-type epoxy resins obtained by reacting polyamines such as diaminodiphenylmethane and isocyanuric acid with epichlorohydrin; and polybasic acids such as phthalic acid and dimer acid obtained by reacting with epichlorohydrin. It can contain one or more components selected from the group consisting of glycidyl ester type epoxy resins.

The epoxy compound (A) preferably contains one or more components selected from the group consisting of a biphenyl novolac type epoxy resin, a phenol novolac type epoxy resin, and a bisphenol A type epoxy resin. In this case, the fluidity of the composition (X) during molding can be particularly improved. Generally, when the composition (X) contains one or more components selected from the group consisting of a biphenyl novolac type epoxy resin, a phenol novolac type epoxy resin, and a bisphenol A type epoxy resin, the composition (X) The fluidity of the composition (X) during molding is high, and blocking of the particles of the composition (X) is likely to occur. However, in the present embodiment, the composition (X) contains the phosphonium salt (C), so that the composition (X) is contained. ) Particle blocking can be sufficiently suppressed.

The total amount of the biphenyl novolac type epoxy resin, the phenol novolac type epoxy resin, and the bisphenol A type epoxy resin with respect to the epoxy compound (A) is preferably in the range of 60 to 100% by mass. In this case, the fluidity of the composition (X) during molding is particularly improved. When the epoxy compound (A) contains a bisphenol A type epoxy resin, the amount of the bisphenol A type epoxy resin with respect to the epoxy compound (A) is preferably 25% or less. In this case, blocking of the composition (X) can be particularly suppressed.

The amount of the epoxy compound (A) with respect to the entire composition (X) is preferably in the range of 5 to 35% by mass. In this case, the fluidity of the composition (X) during molding and the physical characteristics of the sealing material can be improved.

The curing agent (B) will be described. The curing agent (B) can contain a known and commonly used curing agent used in the production of a sealing material. The curing agent (B) is a novolak type resin such as a phenol novolac resin, a cresol novolak resin, or a naphthol novolak resin; a phenol aralkyl resin having a phenylene skeleton or a biphenylene skeleton; an aralkyl type resin such as a naphthol aralkyl resin having a phenylene skeleton or a biphenylene skeleton; Polyfunctional phenolic resin such as triphenol methane type resin; Dicyclopentadiene type phenolic resin such as dicyclopentadiene type phenol novolac resin and dicyclopentadiene type naphthol novolac resin; Terpen modified phenol resin; Bisphenol type resin such as bisphenol A and bisphenol F; It can also contain at least one component selected from the group consisting of triazine-modified novolak resins.

The curing agent (B) preferably contains one or more components selected from the group consisting of phenol novolac resin, biphenyl aralkyl type phenol resin, and monomeric phenol. In this case, the fluidity of the composition (X) during molding can be improved. Generally, when the composition (X) contains one or more components selected from the group consisting of phenol novolac resin, biphenyl aralkyl type phenol resin, and monomeric phenol, the flow of the composition (X) during molding. The property is high and blocking of particles of the composition (X) is likely to occur. However, in the present embodiment, the composition (X) contains the phosphonium salt (C) to block the particles of the composition (X). Can be sufficiently suppressed.

The monomer phenol can contain, for example, at least one of a monomer represented by the following formula (2) and a monomer represented by the following formula (3).

The total amount of the phenol novolac resin, the biphenyl aralkyl type phenol resin, and the monomeric phenol with respect to the curing agent (B) is preferably in the range of 60 to 100% by mass. In this case, the fluidity of the composition during molding is particularly improved. When the curing agent (B) contains monomeric phenol, the amount of monomeric phenol with respect to the curing agent (B) is preferably 25% or less. In this case, blocking of the composition (X) is particularly easy to suppress.

The epoxy compound (A) is preferably in the range of 0.9 to 1.5 equivalents with respect to 1 equivalent of the phenol compound (B). In this case, the composition (X) may have good storage stability.

The phosphonium salt (C) will be described. The phosphonium salt (C) includes a quaternary phosphonium cation (C1) represented by the following formula (1.1), an organic carboxylate anion (C2) represented by the following formula (1.2), and the following formula (1.3). ) Is composed of the phenol compound (C3).

In the phosphonium salt (C), the quaternary phosphonium cation (C1) and the organic carboxylate anion (C2) are ionic bonded. Further, the organic carboxylate anion (C2) and the phenol compound (C3) are hydrogen-bonded. Therefore, the phosphonium salt (C) is a complex compound. An example of a conceptual model of the structure of the phosphonium salt (C) is shown in the following formula (4).

When the composition (X) contains the phosphonium salt (C), it is possible to impart high fluidity at the time of molding, high curability, and high storage stability to the composition (X). As a result, it is possible to achieve both high fluidity during molding of the composition (X) and suppression of blocking of particles of the composition (X). It is considered that this is due to the following interaction acting between the three elements of the quaternary phosphonium cation, the organic carboxylate anion and the phenol compound constituting the phosphonium salt (C).

As shown in the formula (4), each of the organic carboxylate anion (C2) and the phenol compound (C3) has a hydroxyl group or a carbonyl group which are hydrogen-bondable substituents at the 1st and 3rd positions. Therefore, the interaction between the organic carboxylate anion (C2) and the phenol compound (C3) by hydrogen bonds works strongly. As a result, the acid strength of the organic carboxylate anion (C2) is apparently increased, and the organic carboxylate anion (C2) and the quaternary phosphonium cation (C1) are less likely to dissociate. Therefore, at room temperature, the state in which the quaternary phosphonium cation (C1) and the organic carboxylate anion (C2) in the phosphonium salt (C) are not dissociated is maintained, so that the curing of the composition (X) is suppressed. Will be done. Therefore, it is considered that the composition (X) has excellent storage stability and blocking of the composition (X) at room temperature is suppressed. Further, at the initial heating of the composition (X), the strong interaction between the organic carboxylate anion (C2) and the phenol compound (C3) is maintained, so that the quaternary phosphonium cation (C1) and the organic carboxy are maintained. Dissociation with the rat anion (C2) is suppressed. Therefore, at the initial stage of heating the composition (X), the curing reaction does not proceed immediately, and an increase in the melt viscosity of the composition (X) is suppressed. Therefore, excellent fluidity is imparted to the composition (X). Shortly after the start of heating, the interaction between the organic carboxylate anion (C2) and the phenol compound (C3) gradually weakened, and the quaternary phosphonium cation (C1) and the organic carboxylate anion (C2) became Dissociate. As a result, curing of the composition (X) is promoted. Therefore, excellent curability is imparted to the composition (X).

As described above, since the composition (X) contains the phosphonium salt (C), curing of the composition (X) at room temperature and at the initial stage of heating is suppressed. As a result, blocking of the composition (X) at the time of weighing and at the beginning of heating can be suppressed, and the fluidity of the composition (X) at the time of molding can be improved. By suppressing the blocking of the composition (X), the weighing accuracy of the composition (X) can be improved. Further, the sprinkability of the composition (X) can be improved, and the composition (X) can be uniformly sprinkled in the mold.

In the present embodiment, in the formula (1), R ^{1 to} R ³ are independently aryl groups having 6 to 12 carbon atoms, and R ⁴ is an alkyl group having 1 to ⁴ carbon atoms. There is little steric hindrance between the quaternary phosphonium cation (C1) and the organic carboxylate anion (C2) in C), and therefore the stability of the phosphonium salt (C) is high. Further, since R ⁶ and R ⁸ are independently carboxyl groups or hydroxyl groups, and R ¹⁰ is a carboxyl group or hydroxyl group, the organic carboxylate anion (C2) and the phenol compound (C3) are separated from each other. The interaction works strongly, and the above-mentioned composition (X) has excellent storage stability, excellent fluidity during molding, and excellent curability. Further, since R ⁵ and R ⁷ are independently H or alkyl groups having 1 to 4 carbon atoms, the functional groups that react with the epoxy resin on the aromatic ring are not adjacent to each other, and the functional groups that react with the epoxy resin are not adjacent to each other. Steric hindrance around the group is suppressed. Therefore, when the composition (X) is cured, the probability that the functional group that reacts with the epoxy compound (A) remains unreacted is low, and the composition (X) is imparted with high cured product properties.

In formula (1), it is preferable that at least one of R ⁶ and R ⁸ is a carboxyl group. In this case, the storage stability of the composition (X), the fluidity during molding, and the curability are further improved, and the adhesion between the sealing material containing the cured product and the lead frame is further improved. The reason is presumed to be as follows. Since the carboxyl group and the carboxylate anion group have lower nucleophilicity than the hydroxyl group, if at least one of R ⁶ and R ⁸ is a carboxyl group, the phosphonium salt (C) reacts with the epoxy compound (A). Initially, there is no sudden reaction. Even if the reaction proceeds, the carboxylate anion group reacts first, and the carboxyl group tends to remain without reacting. Therefore, the storage stability of the composition (X) and the fluidity during molding are good. When the reaction proceeds to some extent, the phenol compound (C3) is dissociated from the organic carboxylate anion (C2), and a high nucleophilic reactivity of the hydroxyl group in the phenol compound (C3) is exhibited, so that the composition (X) ) Is promoted to cure. As a result, the composition (X) has high curability. The carboxyl group in the organic carboxylate anion (C2) tends to remain in the cured product even after the composition (X) is cured. Therefore, when the cured product comes into contact with the metal surface, the carboxyl group in the composition (X) easily combines with the metal element to form a carboxylate, and if a hydroxyl group or an oxide film is present on the metal surface, the carboxyl group is used. The group easily hydrogen-bonds to the metal surface. Therefore, the cured product can have high adhesion to the metal surface, whereby the encapsulant can have high adhesion to the lead frame.

It is also preferable that R ¹⁰ is a hydroxyl group in the formula (1). In this case, the composition (X) can have higher storage stability, higher fluidity during molding and higher curability. It is considered that this is because the interaction between the organic carboxylate anion (C2) and the phenol compound (C3) due to the hydrogen bond is more likely to occur in the phosphonium salt (C). In particular, when at least one of R ⁶ and R ⁸ is a carboxyl group and R ¹⁰ is a hydroxyl group, a high effect can be obtained. This is because the phenol compound (C3) is in the organic carboxylate anion (C2) in the phosphonium salt (C), the carboxylate anion group in the organic carboxylate anion (C2), and the carboxyl group and the phenol compound (C3). This is thought to be because the two hydroxyl groups are likely to be arranged close to each other, so that the interaction due to hydrogen bonding is more likely to occur.

Further, the phosphonium salt (C) does not contain benzene, and benzene is not generated during the synthesis of the phosphonium salt (C) and is not mixed with the phosphonium salt (C). Therefore, the release of benzene derived from the curing accelerator from the composition (X) is suppressed.

Further, when the composition (X) is prepared by heat-kneading the raw materials, the phosphonium salt (C) is easily dispersed and melted in the composition (X). Therefore, when the semiconductor element is sealed with the composition (X), it is possible to prevent the particles of the phosphonium salt (C) from being caught between the wires and between the bumps and causing insulation failure.

Even if the melting point or softening point of the phosphonium salt (C) is as high as 200 ° C. or higher, the phosphonium salt (C) is easily dispersed and melted in the composition (X). It is considered that this is because the dispersibility of the phosphonium salt (C) in the composition (X) is enhanced by some intermolecular interaction.

In order for the phosphonium salt (C) to be particularly easily dispersed and melted in the composition (X), the melting point or softening point of the phosphonium salt (C) is preferably 200 ° C. or lower, and is in the range of 70 to 140 ° C. It is more preferable if it is inside. When the melting point or the softening point is 140 ° C. or lower, the phosphonium salt (C) is particularly easily dispersed and melted in the composition (X). Further, when the melting point or the softening point is 70 ° C. or higher, fusion when the phosphonium salt (C) is pulverized into a powder is particularly suppressed, and the powdered phosphonium salt (C) is formed during storage. It becomes difficult 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 phosphonium salt (C), the DSC curve is measured by performing differential scanning calorimetry of the phosphonium salt (C) under the condition of a heating rate of 20 ° C./min in an air atmosphere. To get. The temperature at which the endothermic peak appears in this DSC curve is defined as the melting point or softening point.

As a method for lowering the melting point or softening point of the phosphonium salt (C), masterbatch of the phosphonium salt (C) with a phenol resin can be mentioned. The phenol resin preferably has a low viscosity. Examples of the phenol resin 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 phosphonium salt (C) is in the form of powder. Again, the phosphonium salt (C) is particularly susceptible to dispersion and melting in the composition (X). Examples of the method for powdering the phosphonium salt (C) include pulverizing the phosphonium salt (C) with an impact crusher or the like. The powdery phosphonium salt (C) is preferably 100 mesh pass 95% or more. That is, it is preferable that 95% by mass or more of the powdered phosphonium salt (C) passes through 100 mesh (opening 212 μm). This 100 mesh pass is measured by the air jet sheave method. In this case, the phosphonium salt (C) becomes very easy to disperse and melt in the composition (X).

The method for synthesizing the phosphonium salt (C) is not particularly limited. For example, first, an intermediate composed of a quaternary phosphonium cation (C1) and an organic carboxylate anion (C2) is synthesized, and this intermediate is mixed with a phenol compound (C3) to obtain a phosphonium salt (C). Is obtained.

The intermediate can be produced, for example, by the method disclosed in Japanese Patent No. 4492768. Specifically, for example, first, an intermediate is obtained by a salt exchange reaction between an alkyl carbonate of a quaternary phosphonium corresponding to a quaternary phosphonium cation (C1) and an organic carboxylic acid corresponding to an organic carboxylate anion (C2). Is synthesized.

The alkyl carbonate of the quaternary phosphonium can be obtained, for example, by reacting the tertiary phosphine corresponding to the quaternary phosphonium with carbonate diesters. Examples of the tertiary phosphine include triphenylphosphine, tris (4-methylphenyl) phosphine, and 2- (diphenylphosphine) biphenyl. Examples of the carbonic acid diester include diethyl carbonate, dimethyl carbonate, dibutyl carbonate, and diphenyl carbonate. In order to complete the reaction quickly and in good yield, it is preferable to carry out the reaction in a solvent. Examples of the solvent include methanol and ethanol. In order to synthesize an alkyl carbonate of quaternary phosphonium, for example, a reaction solution is prepared by adding tertiary phosphine and carbonate diesters to a solvent, and the reaction solution is placed in an autoclave in the range of 50 to 150 ° C. React at the temperature of 10 to 200 hours.

The intermediate may be synthesized by a salt exchange reaction between a hydroxide of a quaternary phosphonium corresponding to a quaternary phosphonium cation (C1) and an organic carboxylic acid corresponding to an organic carboxylate anion (C2).

The hydroxide of the quaternary phosphonium can be obtained, for example, by reacting a tertiary phosphine corresponding to the quaternary phosphonium with an alkyl halide or an aryl halide and then exchanging salts with an inorganic alkali. Examples of the tertiary phosphine include the same as in the case of obtaining an alkyl carbonate of a quaternary phosphonium. Alkyl halides include, for example, ethyl bromide, butyl chloride, 2-ethylhexyl bromide, 2-butylethanol, and 2-chloropropanol. Examples of aryl halides include bromobenzene, bromonaphthalene, and bromobiphenyl. Examples of the inorganic alkali include sodium hydroxide, potassium hydroxide, calcium hydroxide, barium hydroxide and aluminum hydroxide. In order to complete the reaction quickly and in good yield, it is preferable to carry out the reaction in a solvent. Examples of the solvent include methanol and ethanol. In order to synthesize a quaternary phosphonium hydroxide, for example, a tertiary phosphine and an alkyl halide or an aryl halide and an inorganic alkali are added to a solvent to prepare a reaction solution, and the reaction solution is placed in an autoclave. The reaction is carried out at a temperature in the range of 20 to 150 ° C. for 1 to 20 hours.

When reacting an alkyl carbonate or hydroxide of a quaternary phosphonium with an organic carboxylic acid, for example, a solution containing an alkyl carbonate or hydroxide of a quaternary phosphonium and an organic carboxylic acid is prepared, for example, 30 to 170. The by-produced alcohol, water, carbonate gas and, if necessary, the solvent are removed while reacting at a temperature within the range of ° C. for 1 to 20 hours. As a result, an intermediate is obtained by the salt exchange reaction.

The intermediate is particularly preferably synthesized by a salt exchange reaction between an alkyl carbonate of a quaternary phosphonium and an organic carboxylic acid. In this case, the mixing of ionic impurities such as halogen ions into the final product, the phosphonium salt (C), is suppressed. Therefore, the occurrence of migration in the encapsulant produced from the composition (X) containing the phosphonium salt (C) is suppressed, and therefore the semiconductor device provided with the encapsulant has high reliability.

As described above, the phosphonium salt (C) is obtained by mixing the intermediate with the phenol compound (C3). For that purpose, for example, the intermediate and the phenol compound (C3) are mixed in a solvent such as methanol or ethanol at 50 to 200 ° C. for 1 to 20 hours, and then the solvent is removed. To remove the solvent, for example, the solution is heated at 50-200 ° C. under reduced pressure or normal pressure. As a result, the phosphonium salt (C) is obtained.

The halogen ion content, which is an impurity in the phosphonium salt (C), is preferably 5 ppm or less with respect to the phosphonium salt (C). In this case, migration in the encapsulant produced from the composition (X) is particularly suppressed, and therefore, particularly high reliability can be imparted to the semiconductor device including the encapsulant. Such a low halogen ion content can be achieved by synthesizing the phosphonium salt (C) by a method including a salt exchange reaction between an alkyl carbonate of a quaternary phosphonium and an organic carboxylic acid as described above. ..

The phosphonium salt (C) is preferably in the range of 1 to 20 parts by mass with respect to 100 parts by mass of the epoxy compound (A). When the phosphonium salt (C) is 1 part by mass or more, particularly excellent curability is imparted to the composition (X). Further, when the phosphonium salt (C) is 20 parts by mass or less, the composition (X) is imparted with particularly excellent fluidity during molding. It is particularly preferable that the phosphonium salt (C) is in the range of 2 to 15 parts by mass.

The composition (X) may contain a curing accelerator other than the phosphonium salt (C) in addition to the phosphonium salt (C) as long as it does not deviate from the object of the present invention. For example, the composition (X) contains imidazoles such as triarylphosphines, tetraphenylphosphonium / tetraphenylborate, 2-methylimidazole, and 1,8-diazabicyclo (5) as curing accelerators other than the phosphonium salt (C). , 4,0) Can contain one or more components selected from the group consisting of undecene-7. The amount of the curing accelerator other than the phosphonium salt (C) is preferably 50% by mass or less with respect to the entire curing accelerator including the phosphonium salt (C).

The inorganic filler (D) will be described. The inorganic filler (D) can contain a known and commonly used inorganic filler to be blended in the sealing material. The inorganic filler (D) is, for example, molten silica, spherical silica, spherical molten silica, crushed silica, crystalline silica, spherical alumina, magnesium oxide, boron nitride, aluminum nitride and the like; and has a high dielectric constant such as barium titanate and titanium oxide. Filler; Magnetic filler such as hard ferrite; Inorganic flame retardant such as magnesium hydroxide, aluminum hydroxide, antimony trioxide, antimony pentoxide, guanidine salt, zinc borate, molybdenum compound, zinc nitrate; and silicon nitride, It can contain one or more components selected from the group consisting of talc, barium sulfate, calcium carbonate, mica powder and the like. The inorganic filler (D) preferably contains at least one of silica and alumina. In particular, when the composition (X) contains alumina as the inorganic filler (D), the particles of the composition (X) are generally likely to be blocked, but in the present embodiment, the composition (X) is used. By containing the above-mentioned phosphonium salt (C), blocking of particles of the composition (X) can be suppressed.

The particle size distribution of the inorganic filler (D) is preferably in the range of 3 μm to 20 μm in average particle size. The particle size distribution may be measured by using a commercially available particle size distribution meter (electrical, optical, etc.) sold by Shimadzu Corporation or the like. In this case, the fluidity of the composition (X) during molding can be improved, and the coefficient of thermal expansion of the composition (X) can be adjusted within a suitable range. As a result, when the composition (X) is applied to the production of a thin package, the difference between the thickness of the semiconductor element and the thickness of the encapsulant (also referred to as clearance, see dimension C shown in FIG. 2) Even in the case of a small value in the range of 50 to 200 μm, unfilling of the sealing material can be suppressed and warpage of the package can be suppressed. In particular, when the maximum particle size of the inorganic filler (D) is 75 μm or less (that is, the top cut is 75 μm or less), the composition (X) can be applied to a thin package having a clearance of 100 μm or less. By setting the maximum particle size to 30 μm or less (top cut 30 μm or less), it is possible to apply the composition (X) to a thin package having a clearance of 50 μm.

In the present embodiment, the amount of the inorganic filler (D) with respect to the composition (X) is in the range of 70 to 95% by mass. When the amount of the inorganic filler (D) is less than 70% by mass, the ratio of the epoxy compound (A) to the composition (X) becomes large, the particles of the composition (X) are likely to be blocked, and the inorganic filler is filled. If the amount of the material (D) is larger than 95% by mass, the kneading performed when producing the composition (X) becomes difficult. Therefore, when the amount of the inorganic filler (D) is within the above range, blocking of particles of the composition (X) can be suppressed, and kneading performed when producing the composition (X) is easy. Therefore, the composition (X) can be easily produced. Further, when the amount of the inorganic filler (D) is 70% by mass or more, the flame retardancy of the sealing material which is a cured product of the composition (X) can be ensured. The amount of the inorganic filler (D) with respect to the composition (X) is more preferably 84% by mass or more. In this case, the increase in the coefficient of linear expansion of the composition (X) due to the increase in the coefficient of linear expansion of the composition (X) can be suppressed, and thus the warpage of the package can be suppressed.

The composition (X) may contain additives other than the above-mentioned components. Examples of other additives include silane coupling agents, flame retardants, flame retardant aids, mold release agents, ion trap agents, pigments such as carbon black, colorants, low stress agents, tackifiers, and silicones. Contains a flexing agent.

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. One or more components 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, for example, one or more components selected from the group consisting of carnauba wax, stearic acid, montanic acid, and carboxyl group-containing polyolefins.

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.

The method for producing the composition (X) will be described. First, the above epoxy compound (A), curing agent (B), phosphonium salt (C), inorganic filler (D), and if necessary, additives are blended and uniformly mixed with a mixer, blender, or the like. To make a mixture. Next, this mixture is melt-mixed in a heated state by a kneader such as a hot roll or a kneader. The mixture is then cooled to room temperature to solidify. The solidified mixture is then ground by a known method. As a result, the particulate composition (X) is obtained.

The composition (X) produced in this manner preferably has a particle size distribution in which the proportion of particles having a particle size of 5 mm or more is in the range of 0 to 1% by mass. That is, the proportion of particles having a particle size of 5 mm or more contained in the composition (X) is preferably 1% by mass or less, and it is also preferable that the composition (X) does not contain particles having a particle size of 5 mm or more. In this case, it is possible to improve the accuracy of weighing the composition (X) before placing the composition (X) on the mold. The particle size of the particles of the composition (X) is a so-called powder particle size, and may be measured with a sieve. To measure the particle size of powder, a commercially available automatic sieve (sieves with different diameters of about 30 cm are stacked one above the other and vibrated from a vibrator using a motor or the like for about 10 minutes to measure the particle size distribution. For example, a sieve shaker sold by Nikko Kagaku Co., Ltd., which gives a uniform irregular movement by an elliptical movement and a fixed spring and sorts in a short time) can be used. That is, after 10 minutes of vibration, the weight of the composition (X) remaining on each sieve having different openings may be measured, and the particle size distribution may be determined based on this.

A stereomicroscope or the like can also be used to measure the major axis of the particles of the composition (X). However, it is practical to use the evaluation result by an automatic sieve regardless of the major axis of the particles of the composition (X). For example, as the sieve used for the automatic sieve, a plurality of sieves having a mesh size of 0.3 mm, 0.5 mm, 1.0 mm, 1.5 mm, 2.0 mm and the like may be appropriately combined. As for the opening, a sieve having another opening may be used depending on the intended use of the product. It is useful to use the sieve described in JIS Z 8801 as the sieve, but it is not necessary to be concerned with this.

In the composition (X), the proportion of particles having a particle size of 0.20 mm or less is in the range of 0 to 5% by mass, and the proportion of particles having a particle size of 2.4 mm or more is in the range of 0 to 2% by mass. It is preferable to have a particle size distribution of. When the proportion of particles having a particle size of 0.20 mm or less is 5% by mass or less, blocking of particles of the composition (X) can be particularly suppressed. Further, when the proportion of particles having a particle size of 2.4 mm or more is 2% by mass or less, the sprinkability of the composition (X) becomes particularly good, so that the composition (X) can be uniformly sprinkled in the mold. Further, the measurement accuracy of the composition (X) is particularly improved.

The particle size distribution of the composition (X) described above can be measured using a sieve.

A method for manufacturing a semiconductor device using the composition (X) will be described with reference to FIGS. 1A to 1E. The method for manufacturing a semiconductor device of the present embodiment includes a step (compression molding step) of producing a sealing material by molding the composition (X) by a compression molding method. The method preferably includes a weighing step of weighing the composition (X). The method also preferably includes a step (arrangement step) of arranging the composition (X) in the mold 10. The method also preferably includes a step of preheating the composition (X) arranged in the mold 10 (preheating step). The method also preferably includes a step of heating the encapsulant produced by the compression molding method (post-curing step). These steps will be described.

(Weighing process)
First, as shown in FIG. 1A, the composition (X) is weighed. Specifically, the particulate composition (X) is supplied into the container 20 and the amount of the composition (X) in the container 20 is measured by a known measuring means. When the composition (X) is directly supplied to the lower mold 11 included in the compression molding machine 1, the composition (X) may be weighed by the measuring unit included in the compression molding machine 1. In the present embodiment, since the blocking of particles of the composition (X) is suppressed, the composition (X) can be accurately weighed.

(Placement process)
Next, the mold 10 shown in FIG. 1B is prepared. The mold 10 is provided in the compression molding machine 1. The mold 10 includes a lower mold 11 and an upper mold 12. The lower mold 11 is configured to store the composition (X). The upper mold 12 is arranged so as to face the lower mold 11. The substrate 13 is attached to the surface of the upper die 12 facing the lower die 11. A plurality of semiconductor elements 14 are provided on the substrate 13. The substrate 13 is, for example, a lead frame, a wiring board, or the like, and the semiconductor element 14 is, for example, a semiconductor chip such as an IC chip. Then, in the arranging step, as shown in FIG. 1B, the composition (X) is arranged in the prepared mold 10. Specifically, the composition (X) is placed on the lower mold 11. In the present embodiment, since the blocking of the particles of the composition (X) is suppressed, the particles of the composition (X) can be uniformly scattered in the lower mold 11.

(Preheating process)
Next, as shown in FIG. 1C, the composition (X) arranged in the mold 10 is preheated by heating the lower mold 11. The temperature of the lower mold 11 during preheating is more preferably in the range of 130 to 200 ° C. The heating time is preferably in the range of 2 to 300 seconds, more preferably in the range of 30 to 40 seconds. In the present embodiment, since the composition (X) contains the phosphonium salt (C), the release of benzene from the composition (X) in the preheating step can be suppressed, and the deterioration of the working environment due to benzene can be suppressed. Can be suppressed.

(Compression molding process)
Next, as shown in FIG. 1D, a sealing material is produced by molding the composition (X) by a compression molding method. Specifically, the lower mold 11 is moved toward the upper mold 12 while heating the mold 10. At this time, the melted composition (X) flows so as to cover the semiconductor element 14. As a result, the semiconductor element 14 is sealed with the composition (X). In the present embodiment, since the composition (X) has excellent fluidity during molding, there is a clearance between the thickness of the semiconductor element 14 and the thickness of the sealing material 100 when manufacturing a thin semiconductor device 30 or. Even when is small, unfilling of the composition (X) can be suppressed. The temperature of the lower mold 11 in the compression molding step is preferably in the range of 130 to 200 ° C. The compression pressure is preferably in the range of 5 to 20 MPa. The compression time is preferably in the range of 10 to 100 seconds. Further, in the present embodiment, since the composition (X) contains the phosphonium salt (C), the release of benzene from the composition (X) in the compression molding step can be suppressed, and the working environment is deteriorated by benzene. Can be suppressed.

(Post-curing process)
Next, the composition (X) is cured as shown in FIG. 1E. Specifically, the composition (X) is cured by holding the composition (X) in a mold 10 for a predetermined time while heating it. As a result, a sealing material 100 which is a cured product of the composition (X) is formed, and the plurality of semiconductor elements 14 are sealed by the sealing material 100. The temperature of the mold in the post-curing step is preferably in the range of 130 to 200 ° C., and is preferably maintained in the range of 1 to 10 minutes at this temperature. After the composition (X) is cured, the semiconductor element 14 and the substrate 13 may be removed from the mold 10.

By the above steps, a semiconductor device 30 in which the semiconductor element 14 is sealed by the sealing material 100 which is a cured product of the composition (X) can be obtained, but the method for manufacturing the semiconductor device 30 is not limited to this. Other steps may be provided. Further, as shown in FIG. 2, the semiconductor device 30 manufactured by the above steps is sealed so as to cover the substrate 13, the plurality of semiconductor elements 14 provided on the substrate 13, and the plurality of semiconductor elements 14. The sealing material 100 is included. In the present embodiment, since the improvement of the fluidity of the composition (X) at the time of molding and the suppression of blocking are compatible, the semiconductor device 30 has defects such as deformation of the wire and unfilling of the sealing material 100. Is unlikely to occur.

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

(1) Preparation of composition The compositions of Examples 1 to 18 and Comparative Examples 1 to 6 were prepared by the following methods. The inorganic filler was surface treated with a coupling agent. The treated inorganic filler, curing accelerator, epoxy resin, curing agent, and mold release agent were mixed with a blender for 30 minutes to prepare a homogenized mixture. This mixture was melt-kneaded with two rolls heated to 80 ° C., cooled, and then pulverized with a pulverizer to obtain a particulate composition.

The components used to prepare the composition and their amounts are as shown in Tables 1 and 2 below.

Details of the components shown in Tables 1 and 2 are as shown below.
-Epoxy compound 1: Biphenyl type epoxy resin manufactured by Japan Epoxy Resin Co., Ltd., product number YX4000H, epoxy equivalent 195.
-Epoxy compound 2: Nippon Kayaku Co., Ltd., phenol novolac type epoxy resin, product number NC3000, epoxy equivalent 276.
-Epoxy compound 3: Manufactured by Japan Epoxy Resin Co., Ltd., bisphenol A type epoxy resin, product number YL6810, epoxy equivalent 173.
-Curing agent 1: Phenol novolac manufactured by Meiwa Kasei Co., Ltd., product number DL-92, hydroxyl group equivalent 105.
-Curing agent 2: Biphenyl aralkyl type phenol resin manufactured by Nippon Kayaku Co., Ltd., product number NC3000.
-Curing agent 3: Honshu Chemical Industry Co., Ltd., bisphenol F, product number BPF.
-Curing Accelerator 1: MeTPP-5HIPA-THB PN Resin MB, Part No. RP-701, manufactured by Sun Appro Co., Ltd.
-Curing accelerator 2: TPP-K manufactured by Hokuko Chemical Industry Co., Ltd.
-Inorganic filler 1: Made by Denka Co., Ltd., silica, product number FB875XFC.
-Inorganic filler 2: Made by Denka Co., Ltd., silica, product number FB5FDX.
-Inorganic filler 3: manufactured by Denka Co., Ltd., silica, product number SFP10X.
-Inorganic filler 4: Alumina manufactured by Micron Co., Ltd., product number DAW45.
-Coupling agent: manufactured by Shin-Etsu Chemical Co., Ltd., N-phenyl-γ-aminopropyltrimethoxysilane, product number KBM573.
-Carnauba wax: Manufactured by Dainichi Chemical Industry Co., Ltd., product number MB87.
-Carbon black: Manufactured by Meisei & Company, Inc., product number MA600MJ2.

The above-mentioned curing accelerators 1 and 2 will be described in more detail.

Curing accelerator 1:
The phosphonium salt represented by the following formula (5), which was synthesized by a method including a salt exchange reaction between an alkyl carbonate of a quaternary phosphonium and an organic carboxylic acid, was obtained by master batching with a phenol novolac resin added at the time of synthesis. It is a powdery curing accelerator obtained by passing a product having a phenol novolac resin ratio of 15% by mass through a mesh having a mesh size of 212 μm.

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

(2) Measurement and Evaluation of Physical Properties of Composition The following physical characteristics were measured for the compositions of Examples 1 to 18 and Comparative Examples 1 to 6.

(2-1) Particle size distribution The particle size distribution (also known as powder particle size) of the composition was measured using a sieve. As a result, the particle size distribution of the composition was evaluated according to the following criteria.
1: The particle size of 0.2 mm or less is 7% by mass or more, the particle size of 2.4 mm or more is 2% by mass or less, and the particle size of 5 mm or more is 1% by mass or less.
2: The particle size of 0.2 mm or less is 5% by mass or less, the particle size of 2.4 mm or more is 2% mass or less, and the particle size of 5 mm or more is 1% mass or less.
3: The particle size of 0.2 mm or less is 5% by mass or less, the particle size of 2.4 mm or more is 5% by mass or more, and the particle size of 5 mm or more is 1% by mass or less.
4: Particle size of 0.2 mm or less is 5% by mass or less, particle size of 2.4 mm or more and 5 mm or less is 5% by mass or less, and particle size of 5 mm or more is 2% by mass or more.

In the present invention, the powder particle size need not be limited to the above particle size distribution. The powder particle size may be optimized according to the application. The larger the powder particle size, the lower the weighing accuracy, and the smaller the powder particle size, the higher the weighing accuracy. Therefore, it is useful to select the powder particle size according to the required measurement accuracy.

The particle size of the powder made of the epoxy resin composition for encapsulation of the present application is preferably smaller than the clearance, but even if a powder having a particle size larger than the clearance is present, it does not pose a big problem. This is because even a powder made of a sealing epoxy resin composition having a particle size larger than the clearance is heated, melted, and liquefied during compression molding.

(2-2) Kneading property In the evaluation of kneading property, the material temperature (that is, the temperature of the kneaded product itself obtained by kneading in the kneader is the target temperature value (target within 80 to 130 ° C.). It was evaluated whether the production was stable at a certain temperature value (for example, 90 ° C ± 5 ° C, 100 ° C ± 5 ° C, etc.). When the difference from the target temperature value was large under certain determined kneading conditions. (5 ° C or higher) was set to Δ, and the case where the difference from the target temperature value was small (less than 5 ° C) was set to 〇. When the difference from the target temperature value was large under certain determined kneading conditions, it was obtained. It is conceivable that the kneaded product may vary.

(2-3) Fluidity The fluidity is formed by using a spiral flow measuring mold according to ASTM D3213 at a mold temperature of 175 ° C., an injection pressure of 6.9 MPa (70 kgf / cm ² ), and a molding time of 120 seconds. , The flow distance (unit: cm) was measured.

(2-4) The flame-retardant composition was compression-molded under the conditions of a mold temperature of 175 ° C., a compression pressure of 10 MPa, a compression time of 150 seconds, and a post-curing 175 ° C. / 6h to prepare a test piece. This test piece was subjected to a 20 mm vertical combustion test (UL94V) specified by the IEC60695-11-10B method. Then, those satisfying the V-0 determination standard were evaluated by the criteria of "V-0 pass", and those not satisfying the V-0 determination criterion were evaluated by the criteria of "V-0 not reached".

(2-5) Mold burrs For the evaluation of mold burrs, the width is 5 mm and only the depth is 5 mm from the central part, which is the inlet of the in-house mold for evaluating mold burrs (the epoxy resin composition for sealing for mold burr evaluation). The evaluation was made using a plurality of linear slits (or mold gaps) different from 10 μm, 20 μm, 30 μm, 50 μm, and 100 μm, which were formed radially. The evaluation was performed at a mold temperature of 170 ° C., an injection pressure of 8.6 KN, and a molding time of 120 seconds. A flow length of 5 mm or more in a linear slit (or mold gap) having a width of 5 mm and a depth of 20 μm was evaluated. The flow length of 3 mm or more and less than 5 mm was evaluated as Δ, and the flow length of less than 3 mm was evaluated as 〇.

(2-6) Presence / absence of blocking The composition weighed in 100 g was left in an environment of 25 ° C. and 50% humidity for 2 hours in a container, and then the presence / absence of blocking in the composition was confirmed. Then, the blocking property was evaluated based on the criteria of "x" when there was a lot of blocking, "Δ" when slightly blocking was confirmed, and "○" when almost no blocking was confirmed.

(2-7) Weighing Accuracy First, the weighing unit of the compression molding machine was set to weigh 5 g of the composition, and then the composition was weighed by this weighing unit. Next, the weight of the composition weighed by the measuring unit was measured using a measuring means (commercially available electronic balance) different from the measuring unit. These steps were repeated 30 times. Next, from the results of 30 measurements, the maximum value of the difference between the set value of the measuring unit and the measured value of the weight by a measuring means different from the measuring unit was obtained. The measurement accuracy was evaluated based on the criteria of "◯" when the maximum value was 0.1 g or less and "x" when the maximum value was larger than 0.1 g.

(2-8) Amount of Benzene Generated After heating the composition in a sealed container at 90 ° C. for 30 minutes, the gas in the sealed container is collected, and the amount of benzene in this gas (referred to as the amount of benzene before curing) is headspaced. It was measured by the GC / MS method. The composition was thermoset by heating the composition at 175 ° C. for 6 hours. The cured product thus obtained 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 (referred to as the amount of benzene after curing) is measured by headspace GC / MS. Measured by method. Then, the case where benzene was generated either before or after curing was evaluated as "yes", and the case where benzene was not generated either before or after curing was evaluated as "absent".

(2-9) Package (PKG) Warpage amount (normal temperature)
A PBGA package having a substrate thickness of 0.13 mm, a vertical and horizontal dimension of a region provided with a sealing material of 14 mm, a chip vertical and horizontal dimension of 8 mm, and a chip thickness of 0.15 mm was produced. The mold temperature for compression molding the composition was 175 ° C., and the molding time was 120 seconds. The warpage (coplanarity) of this package at room temperature was measured using a shadow moiré (PS200) manufactured by AKROMETRIX. The package warp (PBGA warp) is based on the criteria of "○" for PKG warpage of 100 μm to -40 μm, “△” for -40 to -80 μm, and “×” for less than -80 μm. ) Was evaluated.

(2-10) Molding Shrinkage To prepare a test sample, a test piece was prepared by transfer molding for convenience. The molding conditions for transfer molding were a mold diameter of 90 mm, a mold temperature of 175 ° C., an injection pressure of 6.9 MPa, and a molding time of 120 seconds. The diameter of the molded test piece was measured, and the shrinkage rate was calculated from the size of the test piece with respect to the diameter of the mold.

X Epoxy resin composition for sealing (composition)
14 Semiconductor element 30 Semiconductor device 100 Encapsulant

Claims (11)

Epoxy resin (A) and
Hardener (B) and
Phosphonium salt (C) and
Inorganic filler (D) and
A particulate epoxy resin composition for encapsulation containing
The phosphonium salt (C) has a structure represented by the following formula (1) and has a structure represented by the following formula (1).

In equation (1)
R ^{1 to} R ³ are independently aryl groups having 6 to 12 carbon atoms, respectively.
R ⁴ is an alkyl group having 1 to ⁴ carbon atoms.
R ⁶ and R ⁸ are independently carboxyl groups or hydroxyl groups, respectively.
R ⁵ and R ⁷ are each independently H or an alkyl group having 1 to 4 carbon atoms.
Each of R ⁹ and R ¹¹ is H,
R ¹⁰ is a carboxyl group or a hydroxyl group,
p, q and r are numbers that satisfy the relationship of p ≧ 1, q ≧ 1, r ≧ 1, and q ≧ r.
The amount of the inorganic filler (D) with respect to the sealing epoxy resin composition is 70 to 95% by mass.
Is within the range of
The sealing epoxy resin composition has a particle size distribution in which the proportion of particles having a particle size of 5 mm or more is in the range of 0 to 1% by mass.
Epoxy resin composition for sealing. Epoxy resin (A) and
Hardener (B) and
Phosphonium salt (C) and
Inorganic filler (D) and
A particulate epoxy resin composition for encapsulation containing
The phosphonium salt (C) has a structure represented by the following formula (1) and has a structure represented by the following formula (1).
In equation (1)

R ^{1 to} R ³ are independently aryl groups having 6 to 12 carbon atoms, respectively.
R ⁴ is an alkyl group having 1 to ⁴ carbon atoms.
R ⁶ and R ⁸ are independently carboxyl groups or hydroxyl groups, respectively.
R ⁵ and R ⁷ are each independently H or an alkyl group having 1 to 4 carbon atoms.
Each of R ⁹ and R ¹¹ is H,
R ¹⁰ is a carboxyl group or a hydroxyl group,
p, q and r are numbers that satisfy the relationship of p ≧ 1, q ≧ 1, r ≧ 1, and q ≧ r.
The amount of the inorganic filler (D) with respect to the sealing epoxy resin composition is in the range of 70 to 95% by mass.
In the sealing epoxy resin composition, the proportion of particles having a particle size of 0.20 mm or less is in the range of 0 to 5% by mass, and the proportion of particles having a particle size of 2.4 mm or more is in the range of 0 to 2% by mass. Has a particle size distribution within
Epoxy resin composition for sealing. Epoxy resin (A) and
Hardener (B) and
Phosphonium salt (C) and
Inorganic filler (D) and
A particulate epoxy resin composition for encapsulation containing
The phosphonium salt (C) has a structure represented by the following formula (1) and has a structure represented by the following formula (1).
In equation (1)

R ^{1 to} R ³ are independently aryl groups having 6 to 12 carbon atoms, respectively.
R ⁴ is an alkyl group having 1 to ⁴ carbon atoms.
R ⁶ and R ⁸ are independently carboxyl groups or hydroxyl groups, respectively.
R ⁵ and R ⁷ are each independently H or an alkyl group having 1 to 4 carbon atoms.
Each of R ⁹ and R ¹¹ is H,
R ¹⁰ is a carboxyl group or a hydroxyl group,
p, q and r are numbers that satisfy the relationship of p ≧ 1, q ≧ 1, r ≧ 1, and q ≧ r.
The amount of the inorganic filler (D) with respect to the sealing epoxy resin composition is in the range of 70 to 95% by mass.
The epoxy resin (A) contains one or more components selected from the group consisting of a biphenyl type epoxy resin, a phenol novolac type epoxy resin, and a bisphenol A type epoxy resin .
The curing agent (B) contains one or more components selected from the group consisting of phenol novolac, biphenyl aralkyl type phenol resin, and monomeric phenol .
Epoxy resin composition for sealing. Epoxy resin (A) and
Hardener (B) and
Phosphonium salt (C) and
Inorganic filler (D) and
A particulate epoxy resin composition for encapsulation containing
The phosphonium salt (C) has a structure represented by the following formula (1) and has a structure represented by the following formula (1).
In the following formula (1)

R ^{1 to} R ³ are independently aryl groups having 6 to 12 carbon atoms, respectively.
R ⁴ is an alkyl group having 1 to ⁴ carbon atoms.
R ⁶ and R ⁸ are independently carboxyl groups or hydroxyl groups, respectively.
R ⁵ and R ⁷ are each independently H or an alkyl group having 1 to 4 carbon atoms.
Each of R ⁹ and R ¹¹ is H,
R ¹⁰ is a carboxyl group or a hydroxyl group,
p, q and r are numbers that satisfy the relationship of p ≧ 1, q ≧ 1, r ≧ 1, and q ≧ r.
The amount of the inorganic filler (D) with respect to the sealing epoxy resin composition is in the range of 70 to 95% by mass.
Molded by compression molding method,
Epoxy resin composition for sealing. The sealing epoxy resin composition has a particle size distribution in which the proportion of particles having a particle size of 5 mm or more is in the range of 0 to 1% by mass.
The epoxy resin composition for sealing according to any one of claims 2 to 4. In the sealing epoxy resin composition, the proportion of particles having a particle size of 0.20 mm or less is in the range of 0 to 5% by mass, and the proportion of particles having a particle size of 2.4 mm or more is in the range of 0 to 2% by mass. Has a particle size distribution within
The epoxy resin composition for sealing according to claim 3 or 4. The epoxy resin (A) contains one or more components selected from the group consisting of a biphenyl type epoxy resin, a phenol novolac type epoxy resin, and a bisphenol A type epoxy resin.
The epoxy resin composition for sealing according to claim 4. The curing agent (B) contains one or more components selected from the group consisting of phenol novolac, biphenyl aralkyl type phenol resin, and monomeric phenol.
The epoxy resin composition for sealing according to any one of claims 1 , 2, 4, and 7. The inorganic filler (D) contains at least one of silica and alumina.
The epoxy resin composition for sealing according to any one of claims 1 to 8. A method for manufacturing a semiconductor device including a semiconductor element and a sealing material for sealing the semiconductor element.
A step of producing the sealing material by molding the sealing epoxy resin composition according to any one of claims 1 to 9 by a compression molding method.
Manufacturing method of semiconductor devices. A step of preheating the sealing epoxy resin composition within a range of 2 to 300 seconds is further included.
The method for manufacturing a semiconductor device according to claim 10.

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