Epoxy resin composition for sealing and semiconductor device

Abstract

To provide an epoxy resin composition for sealing which can enhance storage stability and curing speed during curing, and can reduce a generation amount of chlorine ions extracted from a cured product.SOLUTION: An epoxy resin composition for sealing contains an epoxy compound (A), a phenol compound (B), a curing accelerator (C), an inorganic filler (D), and a carboxylic acid compound (E). The curing accelerator (C) contains amidine silicate (C1) represented by the following formula (1).SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to an epoxy resin composition for encapsulation and a semiconductor device, and more particularly to an epoxy resin composition for encapsulation containing an epoxy compound and a semiconductor device including an encapsulation part including a cured product of the epoxy resin composition for encapsulation.

Background Art

[0002] Patent Document 1 discloses an epoxy resin composition for encapsulation containing (A) an epoxy resin, (B) a phenolic resin-based curing agent, (C) an inorganic filler, and (D) a curing accelerator, wherein the average particle size of (D) the curing accelerator is 10 μm or less, and (D) the curing accelerator may contain at least one compound selected from the group consisting of a phosphobetaine compound, an adduct of a phosphine compound and a quinone compound, and an adduct of a phosphonium compound and a silane compound.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present disclosure is to provide an epoxy resin composition for encapsulation capable of enhancing storage stability and curing rate during curing and reducing the amount of chloride ions extracted from the cured product, and a semiconductor device produced from the epoxy resin composition for encapsulation.

Means for Solving the Problems

[0005] The epoxy resin composition for sealing of the present disclosure contains an epoxy compound (A), a phenol compound (B), a curing accelerator (C), an inorganic filler (D), and a carboxylic acid compound (E). The curing accelerator (C) contains an amidine silicate (C1) represented by the following formula (1).

[0006] [Chemical formula]

[0007] In formula (1), R1 and R2 are each independently hydrogen or an aliphatic hydrocarbon group having 1 to 5 carbon atoms. R3 and R4 are each independently a phenylene group or a naphthylene group. R5 is a phenyl group or a group represented by the following formula (2).

[0008] [Chemical formula]

[0009] In formula (2), n is 3 or more and 8 or less. In formula (2), X is -SH, -NH2, -NH-Ph, -Ph-CH=CH2, -NH-C2H4-NH2, -N=C=O, a glycidyl ether group, or a group represented by the following formula (3).

[0010] [Chemical formula]

[0011] The semiconductor device of the present disclosure includes a semiconductor element and a sealing portion that seals the semiconductor element. The sealing portion includes a cured product of the epoxy resin composition for sealing described above. [Advantages of the Invention]

[0012] It is possible to provide an epoxy resin composition for sealing that can enhance storage stability and curing rate during curing, and can reduce the amount of chloride ions extracted from the cured product, and a semiconductor device produced from the epoxy resin composition for sealing. [Brief Description of the Drawings]

[0013]

Figure 1

DETAILED DESCRIPTION OF THE INVENTION

[0014] [Embodiment] Embodiments of the present disclosure will be described. Note that the following embodiments are only a part of various embodiments of the present disclosure. The following embodiments can be variously modified according to design and the like as long as the object of the present disclosure can be achieved. Also, the operation mechanisms shown below are speculative, and the present disclosure is not restricted by the description of the operation mechanisms below.

[0015] [Overview] The epoxy resin composition for sealing of the present disclosure (hereinafter also referred to as composition (X)) contains an epoxy compound (A), a phenol compound (B), a curing accelerator (C), an inorganic filler (D), and a carboxylic acid compound (E). The curing accelerator (C) contains an amidine silicate (C1) represented by the following formula (1).

[0016] [Chemical formula]

[0017] In formula (1), R1 and R2 are each independently hydrogen or an aliphatic hydrocarbon group having 1 to 5 carbon atoms. R3 and R4 are each independently a phenylene group or a naphthylene group. R5 is a phenyl group or a group represented by the following formula (2).

[0018] [Chemical formula]

[0019] In formula (2), n is 3 or more and 8 or less. In formula (2), X is -SH, -NH2, -NH-Ph, -Ph-CH=CH2, -NH-C2H4-NH2, -N=C=O, a glycidyl ether group, or a group represented by the following formula (3).

[0020]

Chemical formula

[0021] In the present disclosure, the chloride ions extracted from the cured product include, for example, chloride ions derived from impurities (e.g., by-products) having chlorine atoms contained in the epoxy compound (A). Further, "-Ph" in "-NH-Ph" means a phenyl group, and "-Ph-" in "-Ph-CH=CH2" means a phenylene group.

[0022] With the above configuration, the storage stability of the composition (X) and the curing rate during curing can be enhanced, and the amount of chloride ions extracted from the cured product can be reduced. To explain in more detail, since the curing accelerator (C) contains the above-mentioned amidine silicate (C1), the storage stability of the composition (X) can be enhanced without impairing the curability when the composition (X) is heated and cured. Also, due to its reactivity, the amidine silicate (C1) may cause an increase in the extraction amount of chloride ions extracted from the cured product. In contrast, since the composition (X) contains the carboxylic acid compound (E), the reactivity of the amidine silicate (C1) can be controlled. Thereby, the amount of chloride ions extracted from the cured product can be reduced. In other words, the extraction amount of chloride ions generated from the impurities having chlorine atoms contained in the epoxy compound (A) can be reduced. And since the amount of chloride ions extracted from the cured product can be reduced, migration caused by chloride ions in the semiconductor device manufactured using the composition (X) can be suppressed. Therefore, the composition (X) can be suitably used for manufacturing a semiconductor device. Note that "the amount of chloride ions extracted from the cured product can be reduced" more specifically means that the amount of free chloride ions that are a cause of migration in the semiconductor device is reduced.

[0023] (Component) <Epoxy compound> The composition (X) contains an epoxy compound (A). The epoxy compound (A) is a component that can impart heat resistance to the cured product. When the composition (X) is heated, the epoxy compound (A) can react with the phenol compound (B) and cure.

[0024] The molecular form of the epoxy compound (A) is not particularly limited, and the epoxy compound (A) may take any molecular form such as a monomer, oligomer, prepolymer, or polymer.

[0025] The epoxy compound (A) contains at least one selected from the group consisting of alkylphenol novolak type epoxy compounds such as phenol novolak type epoxy compounds and cresol novolak type epoxy compounds; naphthol novolak type epoxy compounds; phenol aralkyl type epoxy compounds having a phenylene skeleton, a biphenylene skeleton, etc.; biphenyl aralkyl type epoxy compounds; naphthol aralkyl type epoxy compounds; polyfunctional epoxy compounds such as triphenol methane type epoxy compounds and alkyl-modified triphenol methane type epoxy compounds; triphenyl methane type epoxy compounds; tetrakisphenol ethane type epoxy compounds; dicyclopentadiene type epoxy compounds; stilbene type epoxy compounds; bisphenol type epoxy compounds such as bisphenol A type epoxy compounds and bisphenol F type epoxy compounds; biphenyl type epoxy compounds; naphthalene type epoxy compounds; alicyclic epoxy compounds; bromine-containing epoxy compounds such as bisphenol A type bromine-containing epoxy compounds; glycidylamine type epoxy compounds obtained by the reaction of polyamines such as diaminodiphenylmethane and isocyanuric acid with epichlorohydrin; and glycidyl ester type epoxy compounds obtained by the reaction of polybasic acids such as phthalic acid and dimer acid with epichlorohydrin.

[0026] <Phenol compound> The composition (X) contains a phenol compound (B). The phenol compound (B) is a component that can react with the epoxy compound (A) as described above.

[0027] The phenolic compound (B) contains at least one selected from the group consisting of novolak-type compounds such as phenol novolak compounds, cresol novolak compounds, and naphthol novolak compounds; phenol aralkyl compounds having a phenylene skeleton or a biphenylene skeleton; aralkyl-type compounds such as naphthol aralkyl compounds having a phenylene skeleton or a biphenylene skeleton; polyfunctional phenolic compounds such as triphenol methane-type resin compounds; dicyclopentadiene-type phenolic compounds such as dicyclopentadiene-type phenol novolak compounds and dicyclopentadiene-type naphthol novolak compounds; terpene-modified phenolic compounds; bisphenol-type compounds such as bisphenol A or bisphenol F; and triazine-modified novolak compounds.

[0028] The equivalent ratio of the epoxy compound (A) to 1 equivalent of the phenolic compound (B) is preferably 0.6 or more and 10 or less. If this equivalent ratio is 0.6 or more, high moisture resistance of the cured product can be achieved. More preferably, this equivalent ratio is 0.8 or more. If this equivalent ratio is 10 or less, good curability of the composition (X) and good heat resistance and strength of the cured product can be achieved. More preferably, this equivalent ratio is 5 or less.

[0029] <Curing accelerator> The composition (X) contains a curing accelerator (C). The curing accelerator (C) can accelerate the progress of the curing reaction between the epoxy compound (A) and the phenolic compound (B).

[0030] (Amidine silicate) The curing accelerator (C) contains an amidine silicate (C1) represented by the following formula (1).

[0031]

Chemical formula

[0032] In formula (1), R1 and R2 are each independently hydrogen or an aliphatic hydrocarbon group having 1 to 5 carbon atoms. R3 and R4 are each independently a phenylene group or a naphthylene group. R5 is a phenyl group or a group represented by the following formula (2).

[0033] [Chemical formula]

[0034] In formula (2), n is 3 or more and 8 or less. In formula (2), X is -SH, -NH2, -NH-Ph, -Ph-CH=CH2, -NH-C2H4-NH2, -N=C=O, a glycidyl ether group, or a group represented by the following formula (3).

[0035] [Chemical formula]

[0036] Since the curing accelerator (C) contains the amidine silicate (C1) as described above, it is possible to enhance the storage stability and the curing rate during curing. Although the exact reason for this is not clearly stated, it is presumed to be due to the following reasons. That is, the amidine silicate (C1) contained in the curing accelerator (C) is composed of a cationic part having an amidine skeleton and an anionic part having a silicate skeleton. The cationic part having an amidine skeleton is relatively highly basic and thus can have high activity. On the other hand, the anionic part having a silicate skeleton can have a high melting point because it has a skeleton derived from dihydroxynaphthalene or catechol. Therefore, the amidine silicate (C1) tends to keep its activity low under temperature conditions such as room temperature. On the other hand, the amidine silicate (C1) tends to have high activity under high temperature conditions, and its activity can be enhanced by heating up to a temperature near the melting point. Since the composition (X) contains such an amidine silicate (C1), it is presumed that the storage stability at room temperature can be enhanced, and the activity can be enhanced by heating, and the curing rate during curing can be enhanced. In the above formula (1), R1 and R2 are each independently preferably a hydrocarbon group having 1 or 2 carbon atoms. In this case, the storage stability and the curing rate during curing can be further enhanced. Also, R5 is preferably a phenyl group or -C3H6SH. In this case too, the storage stability and the curing rate during curing can be further enhanced.

[0037] The amidine silicate (C1) has, for example, a relatively high melting point. For this reason, under normal temperature (for example, room temperature, about 25°C) conditions, the amidine silicate (C1) can be contained in a solid form in the composition (X). Therefore, at normal temperature, the amidine silicate (C1) can hardly enhance the activity of the epoxy compound (A) and the phenol compound (B). Thereby, the storage stability of the composition (X) can be further enhanced. The melting point of the amidine silicate (C1) is preferably 160°C or higher, more preferably 180°C or higher, and still more preferably 200°C or higher. The upper limit of the melting point of the amidine silicate (C1) is not particularly limited, but is, for example, 300°C or lower.

[0038] The amidine silicate (C1) preferably contains at least one selected from the group consisting of the compounds represented by the following formula (11), the following formula (12), and the following formula (13). In this case, the storage stability of the composition (X) and the curing rate during curing can be further enhanced.

[0039]

Chemical formula

[0040]

Chemical formula

[0041]

Chemical formula

[0042] The compounds represented by the above formula (11) to the above formula (13) can be synthesized by the method described in Patent No. 6917707.

[0043] In the composition (X), the content of the curing accelerator (C) relative to the total of the epoxy compound (A) and the phenol compound (B) is preferably 1% by mass or more and 35% by mass or less. If this content is 1% by mass or more, the curing rate during curing can be further increased. More preferably, this content is 3% by mass or more. If this content is 35% by mass or less, the enhanced storage stability of the composition (X) can be maintained. More preferably, this content is 25% by mass or less, and even more preferably 20% by mass or less.

[0044] Further, the content rate of the amidine silicate (C1) with respect to the total of the epoxy compound (A) and the phenol compound (B) is preferably 1% by mass or more and 35% by mass or less. If this content rate is 1% by mass or more, the curing rate during curing can be further increased. More preferably, this content rate is 3% by mass or more. If this content rate is 35% by mass or less, the enhanced storage stability of the composition (X) can be maintained. More preferably, this content rate is 25% by mass or less, and even more preferably 20% by mass or less.

[0045] <Inorganic filler> The composition (X) contains an inorganic filler (D). The inorganic filler (D) can lower the linear expansion coefficient of the cured product. Further, the inorganic filler (D) can enhance the heat resistance and thermal conductivity of the cured product.

[0046] The average particle diameter of the inorganic filler (D) is, for example, 0.5 μm or more and 15 μm or less. In this case, the fluidity of the composition (X) can be maintained well. Note that the average particle diameter of the inorganic filler (D) in the present disclosure is the median diameter (D 50 ) on a volume basis. The median diameter (D 50 ) is calculated from the particle size distribution obtained by measurement by the laser diffraction / scattering method. The particle size distribution can be measured, for example, by a laser diffraction type particle size distribution measuring device, and examples of the laser diffraction type particle size distribution measuring device include MT3300EXII manufactured by Microtrac Bell Corporation.

[0047] The inorganic filler (D) contains inorganic particles (D1) having a particle diameter of 0.1 μm or less, and preferably, the content rate of the inorganic particles (D1) with respect to the inorganic filler (D) is 0.1% by mass or more and 30% by mass or less. In this case, the fluidity during melting of the composition (X) can be maintained better. The lower limit of the average particle diameter of the inorganic particles (D1) is not particularly limited. In the present disclosure, the content rate of the inorganic particles (D1) can be confirmed by measuring the frequency distribution of particle diameters of 0.1 μm or less by a laser diffraction type particle size distribution measuring device. The measuring device may be the same as the above device.

[0048] The inorganic filler (D) can contain at least one selected from the group consisting of, for example, fused silica such as fused spherical silica, crystalline silica, alumina, aluminum nitride, silicon nitride, and the like.

[0049] In the composition (X), the content of the inorganic filler (D) relative to the total of the epoxy compound (A), the phenol compound (B), the curing accelerator (C), and the inorganic filler (D) is preferably 60% by mass or more and 93% by mass or less. If this content is 60% by mass or more, the fluidity when the composition (X) is heated and melted can be increased. More preferably, this content is 65% by mass or more. If this content is 93% by mass or less, the filling property of the composition (X) can be ensured. More preferably, this content is 90% by mass or less.

[0050] <Carboxylic acid compound> The composition (X) contains a carboxylic acid compound (E). The carboxylic acid compound (E) can reduce the amount of chloride ions extracted from the cured product.

[0051] The reason why the above effects can be exerted by the carboxylic acid compound (E) is not exactly clear, but it is presumed to be due to the following reasons.

[0052] The composition (X) contains amidine silicate (C1), and as described above, the cationic moiety having an amidine skeleton constituting the amidine silicate (C1) is relatively highly basic and can have high activity. Therefore, in the cured product, the cationic moiety can extract a proton from the phenolic hydroxyl group derived from the phenolic compound (B), thereby generating a phenoxide ion. The phenoxide ion can have high nucleophilicity. Therefore, the phenoxide ion can perform a nucleophilic attack on atoms contained in the cured product. The cured product contains carbon atoms bonded to chlorine atoms derived from impurities having chlorine atoms, and these carbon atoms are susceptible to nucleophilic attack. Therefore, the carbon atoms bonded to chlorine atoms contained in the cured product are easily attacked by nucleophilic attacks by phenoxide ions, resulting in the elimination of chloride ions. By such a mechanism, chloride ions can be generated from the cured product.

[0053] In contrast, the composition (X) contains a carboxylic acid compound (E). Therefore, even if phenoxide ions are generated in the cured product, the carboxylic acid compound (E) can supply protons to the phenoxide ions and return them to their original phenolic hydroxyl groups. This can suppress the detachment of chloride ions due to the nucleophilic attack of the phenoxide ions. In addition, the carboxylic acid compound (E) can generate carboxylate anions by supplying protons to the phenoxide ions, but these carboxylate anions are not more nucleophilic than the phenoxide ions. Therefore, the carboxylate anions are less likely to nucleophilically attack the carbon atoms to which chlorine atoms are bonded, which are contained in the cured product. Therefore, the detachment of chloride ions due to the nucleophilic attack of the carboxylate anions is less likely to occur. It is presumed that, due to such a mechanism, the carboxylic acid compound (E) makes it difficult for chloride ions to be generated in the cured product, and as a result, the amount of chloride ions extracted from the cured product can be reduced.

[0054] It is preferable that the number of carboxyl groups contained in one molecule of the carboxylic acid compound (E) is 2 or more. In other words, the carboxylic acid compound (E) preferably contains a polyfunctional carboxylic acid compound (E1). In this case, the amount of chloride ions extracted from the cured product can be further reduced. The polyfunctional carboxylic acid compound (E1) preferably contains at least one selected from phthalic acid compounds, aliphatic dicarboxylic acid compounds, and carboxylic acid compounds having an isocyanuric acid ring. In this case, the amount of chloride ions extracted from the cured product can be further reduced.

[0055] In the phthalic acid compound, for example, in addition to the carboxyl group, another functional group may be bonded to the aromatic ring. Examples of the functional group include a hydroxyl group, an alkyl group, an alkoxy group, an acetyl group, a nitro group, an amino group, and the like. Specific examples of the phthalic acid compound include at least one selected from the group consisting of phthalic acid, isophthalic acid, terephthalic acid, 5-hydroxyisophthalic acid, and the like. Among these, the phthalic acid compound preferably contains at least one of phthalic acid and 5-hydroxyisophthalic acid. In this case, the amount of chloride ions extracted from the cured product can be particularly reduced.

[0056] The molecular structure of the aliphatic dicarboxylic acid compound is not particularly limited and may be linear or branched. However, it is preferably linear. Specific examples of the aliphatic dicarboxylic acid compound include at least one selected from the group consisting of malonic acid, succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid, and the like. Among these, the aliphatic dicarboxylic acid compound preferably contains at least one of glutaric acid and adipic acid. Also in this case, the amount of chloride ions extracted from the cured product can be particularly reduced.

[0057] The carboxylic acid compound having an isocyanuric acid ring contains, for example, a compound having two or more carboxylic acids in one molecule. The carboxylic acid compound having an isocyanuric acid ring preferably contains a trifunctional carboxylic acid compound having three carboxylic acids in one molecule. In this case, the amount of chloride ions extracted from the cured product can be particularly reduced. Specific examples of such trifunctional carboxylic acid compounds include tris(3-carboxypropyl)isocyanurate, tris(2-carboxyethyl)isocyanurate, or tris(1-carboxymethyl)isocyanurate, etc.

[0058] The ratio of the number of moles of carboxyl groups of the carboxylic acid compound (E) to the number of moles of cations of the amidine silicate (C1) is preferably 0.5 or more and 1.5 or less. If this ratio is 0.5 or more, the amount of chloride ions generated in the cured product can be further reduced. If this ratio is 1.5 or less, the curability of the composition (X) can be maintained. This ratio is more preferably 0.7 or more. This ratio is more preferably 1.2 or less.

[0059] <Other components> In addition to the epoxy compound (A), phenol compound (B), curing accelerator (C), inorganic filler (D), and carboxylic acid compound (E) mentioned above, the composition (X) may contain an additive (F). The additive (F) contains at least one selected from the group consisting of, for example, defoamers, surface conditioners, coupling agents, waxes, fluxes, viscosity modifiers, leveling agents, low stress agents, and pigments.

[0060] Also, the composition (X) may contain an organic solvent (G). However, it is preferable that the composition (X) does not contain the organic solvent (G), or the content rate of the organic solvent (G) with respect to the solid content of the composition (X) is 0.5 mass% or less. Note that the solid content of the composition (X) means the total of the components excluding the organic solvent (G) in the composition (X).

[0061] (Method for producing an epoxy resin composition for encapsulation) The composition (X) is obtained by blending, simultaneously or sequentially, the components that can be contained in the composition (X) described above, and adding appropriate additives as necessary and mixing them. For example, the constituent components are mixed with a mixer, blender, etc. until they are sufficiently uniform, and then kneaded while heating with a kneader such as a hot roll or a kneader, and then cooled to room temperature. More specifically, a premix obtained by kneading an epoxy compound (A) and a curing accelerator (C) may be prepared, and a phenol compound (B) and an inorganic filler (D) may be mixed with this premix to obtain a mixture. When the inorganic filler (D) contains a plurality of types of raw materials having different average particle diameters, before mixing the inorganic filler (D) into the kneaded product, a mixture of a plurality of types of inorganic fillers (D) having different average particle diameters is prepared in advance, and then the average particle diameter is measured and incorporated into the above-mentioned kneaded product to prepare the composition (X).

[0062] The heating temperature and heating time in the case of heat treatment can be adjusted as appropriate. The heating temperature at this time is preferably, for example, equal to or higher than the flow start temperature of the composition (X) and lower than the reaction start temperature between the epoxy compound (A) and the phenol compound (B). Specifically, the heating temperature is preferably 90°C or higher and 140°C or lower. Also, the cooling method is not particularly limited and can be set as appropriate. In this embodiment, a solid composition (X) is obtained at 25°C.

[0063] The powdery composition (X) may be produced by pulverizing the composition (X) prepared by the above method. Also, the tablet-shaped composition (X) may be produced by tableting the powdery composition (X). In addition to these, the composition (X) may have an appropriate shape.

[0064] The composition (X) can be cured, for example, by heating it to the temperature at which curing starts, whereby a cured product of the composition (X) is obtained. The composition (X) has a high curing rate and is particularly excellent in curability. Therefore, the heating conditions for curing, such as heating temperature, heating time, and maximum heating temperature, etc., may be appropriately adjusted according to the types of the epoxy compound (A), the phenol compound (B), the curing accelerator (C), the carboxylic acid compound (E), and the characteristics of various components.

[0065] (Physical properties of the epoxy resin composition for sealing) The physical properties of the composition (X) according to this embodiment will be described.

[0066] <Properties> For example, the composition (X) is in a solid state at 25°C. When producing a cured product from the composition (X), it can be produced by heating and melting the prepared and stored composition (X).

[0067] <Curability> Composition (X) exhibits good fluidity when heated and melted. For example, as specific physical property values, the time required for the torque value measured under the condition of a temperature of 170°C to reach 0.1 kgf·cm (0.0098 N·m) for 1.67 mL of composition (X) is 30 seconds or more and 100 seconds or less. Specifically, the torque value is measured by using a tester of Curemeter 7P manufactured by JSR Corporation, setting the upper and lower surface temperatures of the mold of the tester to 170°C, and injecting 1.67 mL of the sample. In the present disclosure, the "time required for the torque value measured under the condition of a temperature of 175°C to reach 0.1 kgf·cm for 1.67 mL of the sample" is also referred to as the gel time. In addition, although 1.67 ml of composition (X) is used as the sample for measurement of the above torque value and gel time, the amount of composition (X) in the case of producing a cured product in the present disclosure is not limited. When the gel time is 30 seconds or more, it is easy to maintain good fluidity when producing a sealing portion from composition (X). When the gel time is 100 seconds or less, the curability of composition (X) can be maintained well. In addition, by appropriately adjusting the above components, the gel time can be set to 40 seconds or more, and the gel time can also be set to 80 seconds or less.

[0068] <Fillability> Composition (X) has enhanced fillability. For example, as specific physical property values, composition (X) has a flow distance measured under the conditions of a mold temperature of 175°C, an injection pressure of 70 kgf / cm 2 (6.86 MPa), and a molding time of 180 seconds, in accordance with the spiral flow test method conforming to ASTM D3123, of 50 cm or more. By appropriately adjusting the above components, the above flow distance can also be 100 cm or more, or 150 cm or more. The upper limit of the above flow distance is not particularly limited and can be adjusted as appropriate.

[0069] <Chloride ion extraction amount> The cured product made from the composition (X) has a reduced amount of chloride ion generation. For example, the chloride ion concentration extracted from the cured product is 50 ppm or less. Examples of methods for confirming the chloride ion concentration include the following. First, the cured product is heated in a solvent to extract the chloride ions generated from the cured product. The solvent is not particularly limited, and for example, water, DMF (dimethylformamide), etc. can be used. Subsequently, the solvent used for extraction (hereinafter, the extraction solvent) is recovered, and the content of chloride ions contained in the solvent is measured. The content of chloride ions in the extraction solvent can be measured by ion chromatography. Note that by changing the composition of the composition (X) described above, the chloride ion concentration extracted from the cured product can also be made 30 ppm or less.

[0070] <Potential> The composition (X) has high potential. In the present disclosure, "potential" means that a decrease in fluidity at a relatively low temperature, for example, normal temperature (25°C), hardly occurs, and it has fluidity even at the temperature until it reaches the molding temperature. That is, the composition (X) has high potential due to its high storage stability. And it has the characteristic that it can be cured promptly after reaching the molding temperature.

[0071] (Application Example) An application example of the composition (X) will be described.

[0072] <Semiconductor Device> As described above, the composition (X) can be suitably used for manufacturing the semiconductor device 1. The semiconductor device 1 includes a semiconductor element 3 and a sealing portion 4 that seals the semiconductor element 3. The sealing portion 4 contains the cured product of the composition (X) described above (see FIG. 1). Hereinafter, an example of the semiconductor device 1 and its manufacturing method will be described.

[0073] The semiconductor device 1 includes a semiconductor device 1 in an insertion type package such as, for example, Mini, D - pack, D2 - pack, To22O, To3P, dual - in - line package (DIP), etc., or a surface - mount type package such as quad flat package (QFP), small outline package (SOP), small outline J - lead package (SOJ), plastic ball grid array (PBGA), fine pitch ball grid array (FBGA), wafer - level package (WLP), panel - level package (PLP), fan - out wafer - level package (FO - WLP), fan - out panel - level package (FO - PLP), flip - chip ball grid array (FC - BGA), antenna - in - package (AiP), or system - in - package (SiP).

[0074] FIG. 1 shows a cross - sectional view of the semiconductor device 1 in the present embodiment. This semiconductor device 1 includes a metal lead frame 2, a semiconductor element 3 mounted on the lead frame 2, a wire 5 that electrically connects the semiconductor element 3 and the lead frame 2, and a sealing portion 4 that seals the semiconductor element 3. The semiconductor element 3 is, for example, an integrated circuit, a large - scale integrated circuit, a transistor, a thyristor, a diode, or a solid - state imaging device. The semiconductor element 3 may be a novel power device such as SiC, GaN, etc. The wire 5 may be made of gold, or may contain at least one of silver and copper. That is, the wire 5 may be made of silver or copper. When the wire 5 contains at least one of silver and copper, the wire 5 may be coated with a thin film of a metal such as palladium. Also, the sealing portion 4 seals the wire 5. The sealing portion 4 also seals the die pad 6 and the inner lead 21, and thus the sealing portion 4 is in contact with the lead frame 2. Also, when the lead frame 2 has a plating layer 24, the lead frame 2 is in contact with the plating layer 24.

[0075] In this embodiment, the lead frame 2 includes a die pad 6, inner leads 21, and outer leads 22. The lead frame 2 is made of, for example, copper or a ferroalloy such as 42 alloy. For example, the lead frame 2 includes a main body 23 made of copper or a ferroalloy such as 42 alloy, and a plating layer 24 covering the main body 23. In this case, corrosion of the lead frame 2 can be suppressed. The plating layer 24 contains at least one component of, for example, silver, nickel, and palladium. The plating layer 24 may contain only one kind of metal among silver, nickel, and palladium, or may contain an alloy containing at least one kind of metal among silver, nickel, and palladium. The plating layer 24 may have a laminated structure, for example, a laminated structure composed of a palladium layer, a nickel layer, and a gold layer. The thickness of the plating layer 24 is, for example, in the range of 1 to 20 μm. However, the thickness of the plating layer 24 is not limited to the above value.

[0076] <Method of manufacturing a semiconductor device> A method of manufacturing the semiconductor device 1 will be described.

[0077] The semiconductor element 3 is fixed on the die pad 6 of the lead frame 2 with an appropriate die bonding material 7. Thereby, the semiconductor element 3 is mounted on the lead frame 2.

[0078] Subsequently, the semiconductor element 3 and the inner lead 21 in the lead frame 2 are connected with a wire 5.

[0079] Then, the composition (X) is applied to a part of the semiconductor element 3, the die pad 6, the die bonding material 7, and the lead frame 2. Then, by heating and curing the applied composition (X), a sealing portion 4 for sealing the semiconductor element 3 is formed. When producing the sealing portion 4 by molding the composition (X), it is preferable to apply a pressure molding method. The pressure molding method includes, for example, an injection molding method, a transfer molding method, or a compression molding method, etc. The conditions for molding the composition (X) by the pressure molding method are appropriately set according to the composition of the composition (X). For example, the molding pressure when molding the composition (X) by the pressure molding method is, for example, 3 MPa or more, and the molding temperature is 120 °C or more. In particular, in the case of the transfer molding method, the injection pressure of the composition (X) into the mold is, for example, 3 MPa or more, and preferably 4 MPa or more and 710 MPa or less. Also, the heating temperature (mold temperature) is preferably 120 °C or more, and more preferably 160 °C or more and 190 °C or less. Also, the heating time is, for example, 30 seconds or more and 300 seconds or less, and more preferably 60 seconds or more and 180 seconds or less. In the transfer molding method, after producing the sealing portion 4 in the mold, it is preferable to perform post-curing by heating the sealing portion 4 with the mold closed, and then open the mold to take out the semiconductor device 1. The heating conditions for post-curing are, for example, the heating temperature is 160 °C or more and 190 °C or less, and the heating time is 2 hours or more and 8 hours or less.

[0080] In this way, a semiconductor device 1 including the sealing portion 4 made from the composition (X) is obtained. Note that the manufacturing method of the semiconductor device 1 is not limited to the above method only. In the semiconductor device 1, it is sufficient if the composition (X) described above can be filled to seal electronic components such as the semiconductor element 3.

[0081] (Aspect) The present disclosure includes the following aspects.

[0082] The epoxy resin composition for sealing according to the first aspect of the present disclosure contains an epoxy compound (A), a phenol compound (B), a curing accelerator (C), an inorganic filler (D), and a carboxylic acid compound (E). The curing accelerator (C) contains an amidine silicate (C1) represented by the following formula (1).

[0083] [Chemical formula]

[0084] In formula (1), R1 and R2 are each independently hydrogen or an aliphatic hydrocarbon group having 1 to 5 carbon atoms. R3 and R4 are each independently a phenylene group or a naphthylene group. R5 is a phenyl group or a group represented by the following formula (2).

[0085] [Chemical formula]

[0086] In formula (2), n is 3 or more and 8 or less. In formula (2), X is -SH, -NH2, -NH-Ph, -Ph-CH=CH2, -NH-C2H4-NH2, -N=C=O, a glycidyl ether group, or a group represented by the following formula (3).

[0087] [Chemical formula]

[0088] According to this aspect, it is possible to provide an epoxy resin composition for sealing that can enhance storage stability and the curing rate during curing, and can reduce the amount of chloride ions extracted from the cured product.

[0089] In the epoxy resin composition for sealing according to the second aspect of the present disclosure, in the first aspect, R1 and R2 are each independently a hydrocarbon group having 1 or 2 carbon atoms. R5 is a phenyl group or -C3H6SH.

[0090] According to this aspect, the storage stability and the curing rate during curing can be further enhanced.

[0091] In the encapsulating epoxy resin composition according to the third aspect of the present disclosure, in the first or second aspect, the amidine silicate (C1) includes at least one selected from the group consisting of a compound represented by the following formula (11), a compound represented by the following formula (12), and a compound represented by the following formula (13).

[0092]

Chemical formula

[0093]

Chemical formula

[0094]

Chemical formula

[0095] According to this aspect, the storage stability and the curing rate during curing can be further enhanced.

[0096] In the encapsulating epoxy resin composition according to the fourth aspect of the present disclosure, in any one of the first to third aspects, the carboxylic acid compound (E) contains a polyfunctional carboxylic acid compound (E1).

[0097] According to this aspect, the amount of chloride ions extracted from the cured product can be further reduced.

[0098] In the encapsulating epoxy resin composition according to the fifth aspect of the present disclosure, in the fourth aspect, the polyfunctional carboxylic acid compound (E1) contains at least one selected from the group consisting of a phthalic acid compound, an aliphatic dicarboxylic acid compound, and a carboxylic acid compound having an isocyanuric acid ring.

[0099] According to this aspect, the amount of chloride ions extracted from the cured product can be further reduced.

[0100] In the sealing epoxy resin composition according to the sixth aspect of the present disclosure, in any one of the first to fifth aspects, the ratio of the number of moles of carboxyl groups in the carboxylic acid compound (E) to the number of moles of cations in the amidine silicate (C1) is 0.5 or more and 1.5 or less.

[0101] According to this aspect, the generation amount of chloride ions in the cured product can be further reduced, and the enhanced storage stability of the sealing epoxy resin composition can be maintained.

[0102] The semiconductor device (1) according to the seventh aspect of the present disclosure includes a semiconductor element (3) and a sealing portion (4) that seals the semiconductor element (3). The sealing portion (4) includes a cured product of the sealing epoxy resin composition according to any one of the first to sixth aspects.

Examples

[0103] Hereinafter, more specific examples in the present embodiment will be presented. Note that the present embodiment is not limited only to the following examples.

[0104] 1. Preparation of the composition The composition was prepared by mixing the components shown in Table 1. The details of the components shown in Table 1 are as follows.

[0105] (1) Epoxy compound - Epoxy compound #1: Compound name biphenyl type epoxy compound. Manufactured by Mitsubishi Chemical Corporation. Product name YX4000H. Functional group equivalent (epoxy group equivalent) 187 - 197.

[0106] (2) Phenol compound - Phenol compound #1: Compound name phenol aralkyl compound. Manufactured by Meiwa Kasei Co., Ltd. Product name MEHC7851SS.

[0107] (3) Curing accelerator - Curing accelerator #1: The amidine silicate represented by the following formula (11).

[0108]

Chem.

[0109] - Curing Accelerator #2: Compound Name 2-Phenyl-4,5-dihydroxymethylimidazole. Manufactured by Shikoku Kasei Kogyo Co., Ltd. Product Name 2PHZ-PW.

[0110] (4) Inorganic Filler - Inorganic Filler #1: Compound Name Alumina. Manufactured by Sumitomo Chemical Co., Ltd. Product Name AA-05. Average Particle Size 0.58 μm.

[0111] - Inorganic Filler #2: Compound Name Alumina. Manufactured by Sumitomo Chemical Co., Ltd. Product Name AA-03NF. Average Particle Size 0.25 μm.

[0112] - Inorganic Filler #3: Compound Name Alumina. Manufactured by Nippon Aerosil Co., Ltd. Product Name AluC.

[0113] - Inorganic Filler #4: Compound Name Synthetic Hydrotalcite. Manufactured by Kyowa Chemical Industry Co., Ltd. Product Name DHT-4A. Average Particle Size 0.37 μm.

[0114] (5) Carboxylic Acid Compound - Carboxylic Acid Compound #1: 5-Hydroxyisophthalic Acid. Manufactured by Tokyo Chemical Industry Co., Ltd.

[0115] - Carboxylic Acid Compound #2: Phthalic Acid. Manufactured by Tokyo Chemical Industry Co., Ltd.

[0116] - Carboxylic Acid Compound #3: Adipic Acid. Manufactured by Tokyo Chemical Industry Co., Ltd.

[0117] - Carboxylic Acid Compound #4: Glutaric Acid. Manufactured by Tokyo Chemical Industry Co., Ltd.

[0118] - Carboxylic Acid Compound #5: Tris(3-carboxypropyl)isocyanurate. Manufactured by Shikoku Kasei Kogyo Co., Ltd. Product Name C3CIC Acid.

[0119] - Carboxylic acid compound #6: Tris(3-carboxyethyl)isocyanurate. Manufactured by Shikoku Kasei Kogyo Co., Ltd. Product name: CIC acid.

[0120] (6) Additives - Additive #1: N-Phenyl-3-aminopropyltrimethoxysilane. Manufactured by Shin-Etsu Chemical Co., Ltd. Product name: KBM573.

[0121] - Additive #2: 3-Mercaptopropyltrimethoxysilane. Manufactured by Shin-Etsu Chemical Co., Ltd. Product name: KBM803.

[0122] - Additive #3: Release agent. Manufactured by Dainichi Chemical Industry Co., Ltd. Product name: Carnauba F-100.

[0123] - Additive #4: Pigment. Manufactured by Mitsubishi Chemical Corporation. Product name: MA100 (carbon black).

[0124] 2. Evaluation tests (1) Spiral flow For the composition, in accordance with ASTM 3123, using a spiral flow mold, at a mold temperature of 170°C, an injection pressure of 70 kgf / cm 2 (6.86 MPa), and a molding time of 180 seconds, the resin composition was molded, and the distance (flow distance) it flowed in 180 seconds from the start of molding was measured. The values obtained by the measurement are shown in Table 1. If the flow distance is 100 cm or more, it can be judged that the fluidity during melting is excellent.

[0125] (2) Gel time Using a curastometer test apparatus (manufactured by JSR Corporation, model number curastometer 7P), with the upper and lower temperatures of the mold set at 170°C, when 1.67 ml of the composition sample was injected, the measurement of time was started, the torque value was measured, and the time (gel time) until the torque value reached 0.1 kgf·cm (0.0098 N·m) was measured. The values obtained by the measurement are shown in Table 1. If the gel time is 100 seconds or less, it can be judged that the fluidity during melting is high.

[0126] (3) Chloride ion extraction amount The composition was heated at 170 °C for 6 hours to obtain a cured product. The cured product was heated in water at 121 °C for 24 hours under 2 atmospheres to extract chloride ions from the cured product. After heating, the water used for the extraction of chloride ions was recovered, and the extraction amount of chloride ions contained in the water was measured by ion chromatography. The results are shown in Table 1. When the chloride ion extraction amount is 100 ppm or less, it can be judged that the numerical value of free chloride ions is low.

[0127]

Table 1

Explanation of Symbols

[0128] 1 Semiconductor device 3 Semiconductor element 4 Sealing part

Claims

1. It contains an epoxy compound (A), a phenol compound (B), a curing accelerator (C), an inorganic filler (D), and a carboxylic acid compound (E), wherein the curing accelerator (C) contains an amidine silicate (C1) represented by the following formula (1), 【Chemical 1】 In formula (1), R １ and R ２ are each independently hydrogen or an aliphatic hydrocarbon group having 1 to 5 carbon atoms, and R ３ and R ４ are each independently a phenylene group or a naphthylene group, and R ５ is a phenyl group or a group represented by the following formula (2). [Chemical 2] in formula (2), n is 3 or more and 8 or less, In formula (2), X is -SH, -NH ２ , -NH-Ph, -Ph-CH=CH ２ , -NH-C ２ H ４ -NH ２ , -N=C=O, a glycidyl ether group, or a group represented by the following formula (3). 【Chemical Formula 3】 An epoxy resin composition for encapsulation.

2. Said R １ and said R ２ are each independently a hydrocarbon group having 1 or 2 carbon atoms, and said R ５ is a phenyl group or -C ３ H ６ SH, The epoxy resin composition for encapsulation according to Claim 1.

3. The amidine silicate (C1) contains at least one selected from the group consisting of a compound represented by the following formula (11), a compound represented by the following formula (12), and a compound represented by the following formula (13), 【Chemical 4】 [Chemical Formula 5] ​ The epoxy resin composition for encapsulation according to Claim 1.

4. The carboxylic acid compound (E) contains a polyfunctional carboxylic acid compound (E1), The epoxy resin composition for encapsulation according to Claim 1.

5. The polyfunctional carboxylic acid compound (E1) contains at least one selected from the group consisting of a phthalic acid compound, an aliphatic dicarboxylic acid compound, and a carboxylic acid compound having an isocyanuric acid ring, The epoxy resin composition for encapsulation according to Claim 4.

6. The ratio of the number of moles of carboxyl groups of the carboxylic acid compound (E) to the number of moles of cations of the amidine silicate (C1) is 0.5 or more and 1.5 or less, The epoxy resin composition for encapsulation according to Claim 1.

7. It includes a semiconductor element and an encapsulation part for encapsulating the semiconductor element, wherein the encapsulation part contains a cured product of the epoxy resin composition for encapsulation according to any one of Claims 1 to 6, A semiconductor device.

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