JP2020090634A - Resin composition for sealing and power module - Google Patents

Abstract

To provide a resin composition for sealing for obtaining a power semiconductor device excellent in insulating characteristics.SOLUTION: A resin composition for sealing is used for sealing a power semiconductor element that contains the following components (A) to (C): (A) an epoxy resin, (B) an inorganic filler and (C) acetylene black and satisfies any one of the following conditions (i) to (iv). (i) a semiconductor element having power consumption of 2.0 W or more. (ii) a semiconductor element composed of one or more semiconductors selected from SiC, GaN, GaOand diamond. (iii) a semiconductor element having a voltage of 1.0 V or more. (iv) a semiconductor element having power density of 10 W/cmor more.SELECTED DRAWING: Figure 1

Description

The present invention relates to a sealing resin composition and a power module.

As a technique for improving the electrical characteristics of a semiconductor package, there is one described in Patent Document 1 (Japanese Patent Laid-Open No. 2007-161990). The same document describes an epoxy resin molding material for encapsulation containing an epoxy resin, a curing agent, and a colorant resin mixture in which a resin and a colorant having an electric resistivity in a specific range are mixed in advance. According to the document, the epoxy resin molding material for sealing has good fluidity, curability, and colorability, and even when used as a sealing material in an electronic component device having a narrow pad-to-pad or wire-to-wire distance. It is said that an electronic component device having excellent electrical characteristics can be obtained.

JP, 2007-161990, A

Here, the sealing material of the power semiconductor element is required to ensure high reliability, and specifically, excellent insulating characteristics are required.
In this regard, as a result of the present inventor's examination of the technique described in Patent Document 1 described above, there is room for improvement in obtaining a power semiconductor device having excellent insulating characteristics.
Therefore, the present invention provides a sealing technique for obtaining a power semiconductor device having excellent insulation characteristics.

The following components (A) to (C):
(A) Epoxy resin,
Provided is a resin composition for encapsulation, which comprises (B) an inorganic filler and (C) acetylene black and is used for encapsulating a power semiconductor element satisfying any of the following conditions (i) to (iv). It
(I) Semiconductor element with power consumption of 2.0 W or more (ii) Semiconductor element made of one or more semiconductors selected from the group consisting of SiC, GaN, Ga ₂ O ₃ and diamond (iii) Voltage is 1.0 V or more Semiconductor device (iv) Semiconductor device with power density of 10 W/cm ³ or more

Further, according to the present invention,
A power module in which a power semiconductor element satisfying any of the above conditions (i) to (iv) is sealed with the cured product of the sealing resin composition in the present invention is provided.

According to the present invention, it is possible to provide a sealing technique for obtaining a power semiconductor device having excellent insulating characteristics.

It is sectional drawing which shows the structure of the semiconductor device in this embodiment. It is sectional drawing which shows the structure of the semiconductor device in this embodiment.

Hereinafter, embodiments will be described with reference to the drawings. In all the drawings, the same reference numerals are given to the same components, and the description will be appropriately omitted. Moreover, the figures are schematic and do not necessarily match the actual dimensional ratios.

In this embodiment, the sealing resin composition contains the following components (A) to (C).
(A) Epoxy resin (B) Inorganic filler (C) Acetylene black The encapsulating resin composition is used for encapsulating a power semiconductor element satisfying any of the following conditions (i) to (iv). It is a thing.
(I) Semiconductor device with power consumption of 2.0 W or more (ii) Semiconductor device made of one or more semiconductors selected from the group consisting of SiC, GaN, Ga ₂ O ₃ and diamond (iii) Voltage is 1.0 V or more Semiconductor element (iv) having a power density of 10 W/cm ³ or more First, each component contained in the encapsulating resin composition will be described.

(Component (A))
Examples of the epoxy resin as the component (A) include biphenyl type epoxy resin; bisphenol A type epoxy resin, bisphenol F type epoxy resin, tetramethylbisphenol F type epoxy resin and other bisphenol type epoxy resin; stilbene type epoxy resin; phenol novolac. Type epoxy resin, novolac type epoxy resin such as cresol novolak type epoxy resin; polyfunctional epoxy resin such as triphenolmethane type epoxy resin, alkyl modified triphenolmethane type epoxy resin; selected from the group consisting of phenylene skeleton and biphenylene skeleton Phenol aralkyl type epoxy resin such as naphthol aralkyl type epoxy resin having 1 or 2 skeleton selected from the group consisting of phenol aralkyl type epoxy resin having 1 or 2 skeleton, phenylene skeleton and biphenylene skeleton; dihydroxynaphthalene type epoxy resin , Naphthol type epoxy resins such as epoxy resins obtained by glycidyl etherification of dihydroxynaphthalene dimers; triazine nucleus-containing epoxy resins such as triglycidyl isocyanurate and monoallyl diglycidyl isocyanurate; dicyclopentadiene modified phenolic epoxy resins Examples of the bridged cyclic hydrocarbon compound-modified phenol type epoxy resin include one type, and these may be used alone or in combination of two or more types.
From the viewpoint of improving the insulating properties of the power module obtained using the sealing resin composition, the epoxy resin is preferably an o-cresol novolac type epoxy resin, a triphenolmethane type epoxy resin, a phenol aralkyl type epoxy resin, or bisphenol. It is one or more selected from the group consisting of A-type epoxy resins and biphenyl-type epoxy resins.

The content of the component (A) in the encapsulating resin composition is 100% by mass of the entire encapsulating resin composition from the viewpoint of obtaining suitable fluidity at the time of molding to improve filling properties and moldability. When it does, it is preferably 2% by mass or more, more preferably 3% by mass or more, and further preferably 4% by mass or more.
From the viewpoint of improving the insulating properties of the power module obtained using the encapsulating resin composition, the content of the component (A) in the encapsulating resin composition is 100% by mass based on the entire encapsulating resin composition. Is 40% by mass or less, more preferably 30% by mass or less, still more preferably 15% by mass or less, still more preferably 10% by mass or less.

(Component (B))
As the inorganic filler of the component (B), those generally used in semiconductor encapsulating resin compositions can be used. Specific examples of the inorganic filler include silica such as fused silica and crystalline silica; alumina; talc; titanium oxide; silicon nitride; aluminum nitride. These inorganic fillers may be used alone or in combination of two or more.

The component (B) preferably contains silica from the viewpoint of excellent versatility. Specific examples of silica include spherical silica such as fused silica and crushed silica. From the viewpoint of improving the mechanical strength of the encapsulating resin composition, the component (B) more preferably contains crushed silica.

The content of the component (B) in the encapsulating resin composition improves the low hygroscopicity and low thermal expansion of the encapsulant formed using the encapsulating resin composition, and the moisture resistance of the obtained semiconductor device is improved. From the viewpoint of more effectively improving reliability and reflow resistance, when the total amount of the encapsulating resin composition is 100% by mass, it is preferably 50% by mass or more, more preferably 60% by mass or more, and further preferably Is 65% by mass or more.
Further, the content of the component (B) in the encapsulating resin composition is the encapsulating resin composition from the viewpoint of more effectively improving the fluidity and filling property during molding of the encapsulating resin composition. When the whole is 100 mass %, it is preferably 95 mass% or less, more preferably 90 mass% or less.

When the component (B) contains crushed silica, the content of the crushed silica in the encapsulating resin composition is the whole encapsulating resin composition from the viewpoint of improving the mechanical strength of the encapsulating resin composition. When it is 100% by mass, it is preferably 1% by mass or more, more preferably 3% by mass or more, further preferably 5% by mass or more.
Further, from the viewpoint of more effectively improving the fluidity and filling property during molding, the content of crushed silica in the encapsulating resin composition is 100% by mass of the encapsulating resin composition as a whole, It is preferably 90% by mass or less, more preferably 85% by mass or less, and even more preferably 10% by mass or less.

(Component (C))
Ingredient (C) is acetylene black.
The content of the component (C) in the encapsulating resin composition is preferably 0.10% by mass or more, and more preferably from the viewpoint of obtaining excellent laser imprintability. Is 0.20 mass% or more. Further, from the viewpoint of improving the insulation characteristics of the power module obtained using the encapsulating resin composition, the content of the component (C) in the encapsulating resin composition is based on the entire encapsulating resin composition. It is preferably 1.0% by mass or less, more preferably 0.8% by mass or less, still more preferably 0.6% by mass or less, still more preferably 0.5% by mass or less.

When the component (C) is in the form of particles, the average particle size d ₅₀ of the secondary particles is preferably 0.1 μm or more, more preferably 0.15 μm, from the viewpoint of improving workability. That is all.
Further, from the viewpoint of enhancing the filling property in the isthmus during molding, the average particle diameter d ₅₀ of the secondary particles of the component (C) is preferably 20 μm or less, more preferably 10 μm or less.
Here, the average particle diameter d ₅₀ of the secondary particles of acetylene black is measured by the laser diffraction method.

The content of the metal in the component (C) is preferably 10 ppm or less, more preferably 5 ppm or less, and further preferably from the viewpoint of improving the insulating properties of the power module obtained by using the sealing resin composition. It is 3 ppm or less, and more preferably 0 ppm. From the same viewpoint, the content of the metal in the component (C) is preferably below the detection limit in the following measuring method.
When the component (C) contains a metal, its content may be, for example, 0.01 ppm or more.
Here, the content of the metal in the component (C) is measured by the following method.
(Measuring method)
1. A sample of the component (C) is passed through a sieve having openings of 75 μm to obtain a fraction under the sieve.
2. Above 1. The content of metal in the under-sieved fraction obtained in 1. is measured by the following method and conditions to be the content of metal in the component (C).
Measurement method: Inductively Coupled Plasma-Atomic Emission Spectro-metry (IPC) method

The content of SO ₄ ^2- ions in the component (C) is preferably 2 ppm or less, and more preferably 1 ppm or less from the viewpoint of improving the insulating properties of the power module obtained by using the encapsulating resin composition. , More preferably 0.5 ppm or less, still more preferably 0 ppm. From the same viewpoint, the content of SO ₄ ²⁻ ion in the component (C) is preferably below the detection limit in the following measuring method.
When the component (C) contains SO ₄ ²⁻ ions, its content may be, for example, 0.01 ppm or more.
Here, the content of SO ₄ ²⁻ ions in the component (C) is measured by the following method.
(Measuring method)
1. A sample of the component (C) is set in a combustion decomposition unit, burned in a combustion gas stream containing oxygen, and the generated gas is collected in an absorbing liquid (hydrogen peroxide aqueous solution).
2. The SO ₄ ²⁻ ion collected in the absorption liquid is separated and quantified by ion chromatography.

The nitrogen adsorption specific surface area of the component (C) is preferably 30 m ² /g or more, more preferably 32 m ² /g or more, and further preferably 34 m ² /g or more, from the viewpoint of improving the insulating property.
Further, from the viewpoint of improving the dispersibility in the resin, the nitrogen adsorption specific surface area of the component (C) is preferably 150 m ² /g or less, more preferably 130 m ² /g or less, and further preferably 100 m ² /g. It is below.
Here, the nitrogen adsorption specific surface area in the component (C) is measured by the following method.
(Measuring method)
1. Degas the sample of component (C).
2. The degassed sample is immersed in liquid nitrogen, the amount of nitrogen adsorbed on the carbon surface at equilibrium is measured by the BET method, and the specific surface area (m ² /g) is calculated from the obtained measured value.

In the present embodiment, the encapsulating resin composition may include components other than the components (A) to (C).
For example, the sealing resin composition may further contain a curing agent.

(Curing agent)
The curing agent can be roughly classified into three types, for example, a polyaddition type curing agent, a catalyst type curing agent, and a condensation type curing agent, and one type or two or more types thereof can be used.

Examples of polyaddition type curing agents include aliphatic polyamines such as diethylenetriamine (DETA), triethylenetetramine (TETA) and metaxylylenediamine (MXDA), diaminodiphenylmethane (DDM), m-phenylenediamine (MPDA), In addition to aromatic polyamines such as diaminodiphenyl sulfone (DDS), polyamine compounds containing dicyandiamide (DICY), organic acid dihydralazide and the like; alicyclic acids such as hexahydrophthalic anhydride (HHPA) and methyltetrahydrophthalic anhydride (MTHPA) Acid anhydrides including aromatic acid anhydrides such as anhydrides, trimellitic anhydride (TMA), pyromellitic anhydride (PMDA), benzophenone tetracarboxylic acid (BTDA); phenols such as novolac type phenolic resins and polyvinylphenol Resin curing agents; polymercaptan compounds such as polysulfides, thioesters and thioethers; isocyanate compounds such as isocyanate prepolymers and blocked isocyanates; organic acids such as carboxylic acid-containing polyester resins.

Examples of the catalyst type curing agent include tertiary amine compounds such as benzyldimethylamine (BDMA) and 2,4,6-trisdimethylaminomethylphenol (DMP-30); 2-methylimidazole, 2-ethyl-4- Examples thereof include imidazole compounds such as methylimidazole (EMI24); Lewis acids such as BF3 complex.

Examples of the condensation type curing agent include a phenol resin; a urea resin such as a methylol group-containing urea resin; and a melamine resin such as a methylol group-containing melamine resin.

Among these, a phenol resin curing agent is preferable from the viewpoint of improving the balance of flame resistance, moisture resistance, electrical characteristics, curability, storage stability and the like. As the phenol resin curing agent, any of monomers, oligomers and polymers having two or more phenolic hydroxyl groups in one molecule can be used, and the molecular weight and the molecular structure thereof are not limited.

Examples of the phenol resin curing agent used as the curing agent include novolac type phenol resins such as phenol novolac resin, cresol novolac resin, and bisphenol novolac resin; polyvinyl phenol; polyfunctional type such as phenol/hydroxybenzaldehyde resin and triphenolmethane type phenol resin. Phenolic resin; Modified phenolic resin such as terpene modified phenolic resin and dicyclopentadiene modified phenolic resin; Phenol aralkyl resin having phenylene skeleton and/or biphenylene skeleton, aralkyl type phenolic resin such as naphthol aralkyl resin having phenylene and/or biphenylene skeleton Examples thereof include bisphenol compounds such as bisphenol A and bisphenol F, and these may be used alone or in combination of two or more. Among these, from the viewpoint of improving the insulating properties of the power module obtained by using the resin composition for sealing, it is selected from the group consisting of a biphenylaralkyl-type phenol resin, a novolac-type phenol resin, and a phenylene skeleton-containing phenol aralkyl resin. It is more preferable to use one kind or two or more kinds.

In the present embodiment, the combination of the component (A) and the phenol resin curing agent is preferably a combination of biphenylaralkyl-type epoxy resin/biphenylaralkyl-type phenol resin, orthocresol novolac-type epoxy resin/novolac-type phenol resin. And combinations of biphenyl type epoxy resin/phenol aralkyl resin.

In the present embodiment, the content of the curing agent in the encapsulating resin composition is a resin composition for encapsulation from the viewpoint of achieving excellent fluidity during molding and improving the filling property and moldability. It is preferably 1% by mass or more, more preferably 2% by mass or more, and further preferably 3% by mass or more based on the whole.
Further, regarding the semiconductor device obtained by using the encapsulating resin composition, the content of the curing agent in the encapsulating resin composition is the encapsulating resin composition from the viewpoint of improving moisture resistance reliability and reflow resistance. It is preferably 25% by mass or less, more preferably 15% by mass or less, still more preferably 10% by mass or less, based on the whole product.

Moreover, the resin composition for sealing may further contain a low stress agent.

Specific examples of the low stress agent include silicone oil, silicone rubber, and carboxyl group-terminated butadiene acrylonitrile rubber. From the viewpoint of improving resin fluidity, the low stress agent preferably contains at least one selected from the group consisting of silicone oil and carboxyl group-terminated butadiene acrylonitrile rubber.

The content of the low stress agent in the encapsulating resin composition is preferably 0.01% by mass or more with respect to the entire encapsulating resin composition from the viewpoint of improving the connection reliability of the power module. It is more preferably 0.02 mass% or more, preferably 2.0 mass% or less, and more preferably 1.0 mass% or less.

The encapsulating resin composition may contain components other than the above-mentioned components, and various additives such as a curing accelerator, a coupling agent, a release agent, an ion scavenger, a flame retardant, and an antioxidant. One or more of them can be appropriately mixed.

Examples of the curing accelerator include phosphorus atom-containing compounds such as organic phosphines, tetra-substituted phosphonium compounds, phosphobetaine compounds, adducts of phosphine compounds with quinone compounds, adducts of phosphonium compounds with silane compounds; 1,8-diazabicyclo. [5.4.0] Undecene-7, benzyldimethylamine, one kind selected from nitrogen atom-containing compounds such as tertiary amines, quaternary salts of amines and amines such as 2-methylimidazole and the like. Alternatively, two or more types can be included. Among these, it is more preferable to include a phosphorus atom-containing compound from the viewpoint of improving curability. Further, from the viewpoint of improving the balance between moldability and curability, it has latent properties such as tetra-substituted phosphonium compounds, phosphobetaine compounds, adducts of phosphine compounds and quinone compounds, adducts of phosphonium compounds and silane compounds, and the like. It is more preferable to include those.
The content of the curing accelerator in the encapsulating resin composition is preferably 0.01% by mass or more based on the entire encapsulating resin composition from the viewpoint of enhancing the curing characteristics of the encapsulating resin composition. %, more preferably 0.05% by mass or more, preferably 2.0% by mass or less, and more preferably 1.0% by mass or less.

Examples of the coupling agent include various silane compounds such as aminosilanes such as epoxysilane, mercaptosilane, and phenylaminosilane, alkylsilanes, ureidosilanes, vinylsilanes, methacrylsilanes, titanium compounds, aluminum chelates, aluminum/zirconium compounds, and the like. One or two or more selected from known coupling agents of Among these, epoxy silane or amino silane is more preferable, and secondary amino silane is more preferable from the viewpoint of fluidity and the like, in order to more effectively exhibit the effects of the present invention. Examples of preferable coupling agents include phenylaminopropyltrimethoxysilane.
The content of the coupling agent in the encapsulating resin composition is preferably 0.01 mass with respect to the entire encapsulating resin composition from the viewpoint of obtaining preferable fluidity during molding of the encapsulating resin composition. % Or more, more preferably 0.05% by mass or more, preferably 2.0% by mass or less, and more preferably 1.0% by mass or less.

The releasing agent is, for example, one or more kinds selected from natural waxes such as carnauba wax; synthetic waxes such as oxidized polyethylene wax and montanic acid ester wax; higher fatty acids such as zinc stearate and metal salts thereof; and paraffin. Can be included.
The content of the release agent in the encapsulating resin composition is preferably 0.01% by mass or more with respect to the entire encapsulating resin composition from the viewpoint of obtaining preferable release characteristics of the cured product. It is more preferably 0.05% by mass or more, preferably 2.0% by mass or less, and more preferably 1.0% by mass or less.

The ion scavenger contains, for example, hydrotalcite.
The content of the ion scavenger in the encapsulating resin composition is preferably 0.03% by mass or more based on the whole encapsulating resin composition from the viewpoint of improving the reliability of the semiconductor device. It is preferably 0.05% by mass or more, preferably 2.0% by mass or less, and more preferably 1.0% by mass or less.

The flame retardant can include, for example, one or more selected from aluminum hydroxide, magnesium hydroxide, zinc borate, zinc molybdate, and phosphazene.

The antioxidant includes, for example, one or more selected from hindered phenol compounds, hindered amine compounds and thioether compounds.

Next, the shape of the sealing resin composition will be described.
In the present embodiment, the encapsulating resin composition is in the form of particles or sheet, for example.
Specific examples of the particulate encapsulating resin composition include tablets and powders. Of these, when the encapsulating resin composition is in the form of a tablet, the encapsulating resin composition can be molded using, for example, a transfer molding method. When the encapsulating resin composition is a powder or granular material, the encapsulating resin composition can be molded using, for example, a compression molding method. Here, the fact that the encapsulating resin composition is a powder or granule means that it is in the form of powder or granules.

(Method for producing encapsulating resin composition)
Next, a method for producing the encapsulating resin composition will be described.
In the present embodiment, the encapsulating resin composition is, for example, a method in which the above-mentioned components are mixed by a known means, further melt-kneaded by a kneader such as a roll, a kneader or an extruder, and cooled and then pulverized. Can be obtained by Further, if necessary, the resin composition for particulate encapsulation may be obtained by tableting into tablets after crushing in the above method. In addition, a sheet-shaped sealing resin composition may be obtained by, for example, vacuum lamination molding or compression molding after pulverization in the above method. The degree of dispersion, fluidity, etc. of the obtained sealing resin composition may be appropriately adjusted.

The encapsulating resin composition obtained in the present embodiment is suitable for encapsulating a power semiconductor element because it contains the components (A) to (C), and is used for encapsulating a power semiconductor element to provide insulating properties. An excellent power semiconductor device can be obtained.

(Semiconductor device)
The semiconductor device according to the present embodiment is a power semiconductor device in which a power semiconductor element is sealed with a cured product of the above-described sealing resin composition according to the present embodiment, and is preferably a power module. The power semiconductor element satisfies any of the following conditions (i) to (iv).
(I) Semiconductor device with power consumption of 2.0 W or more (ii) Semiconductor device made of one or more semiconductors selected from the group consisting of SiC, GaN, Ga ₂ O ₃ and diamond (iii) Voltage is 1.0 V or more Semiconductor device (iv) having a power density of 10 W/cm ³ or more

The base material of the semiconductor device is, for example, a wiring board such as an interposer or a lead frame. In addition, the semiconductor element is electrically connected to the base material by wire bonding, flip chip connection, or the like.
Examples of a semiconductor device obtained by encapsulating a semiconductor element by encapsulation molding using an encapsulating resin composition include, for example, QFP (Quad Flat Package), SOP (Small Outline Package), BGA (Ball Grid Array), CSP (Chip Size Package), QFN (Quad Flat Non-leaded Package), SON (Small Outline Non-leaded Package), LF-BGA (Lead Flame BGA), TO-220, TO-247 and the like.
In the present embodiment, the encapsulating resin composition can also be applied to a structure formed by MAP (Mold Array Package) molding, which is often applied to molding of these packages in recent years. In this case, a package is obtained by collectively encapsulating a plurality of semiconductor elements mounted on the base material with the encapsulating resin composition.
Hereinafter, a more specific description will be given with reference to the drawings.

1 and 2 are cross-sectional views showing the structure of a semiconductor device. In the present embodiment, the configuration of the semiconductor device is not limited to that shown in FIGS.
First, the semiconductor device 100 shown in FIG. 1 is specifically a power module and includes a semiconductor element 20 mounted on a substrate 30 and an encapsulant 50 encapsulating the semiconductor element 20. ing. The semiconductor element 20 is specifically a power semiconductor element.
The encapsulating material 50 is composed of a cured product obtained by curing the encapsulating resin composition according to the present embodiment described above.

Further, FIG. 1 illustrates the case where the substrate 30 is a circuit board. In this case, as shown in FIG. 1, a plurality of solder balls 60, for example, are formed on the other surface of the substrate 30 opposite to the one surface on which the semiconductor element 20 is mounted. The semiconductor element 20 is mounted on the substrate 30 and is electrically connected to the substrate 30 via the wires 40. On the other hand, the semiconductor element 20 may be flip-chip mounted on the substrate 30. Here, the wire 40 is not limited, but examples thereof include Au wire, Al wire, Cu wire, and Ag wire, and the wire 40 is preferably made of copper.

The sealing material 50 seals the semiconductor element 20 so as to cover, for example, the other surface of the semiconductor element 20 opposite to the one surface facing the substrate 30. In the example shown in FIG. 1, the sealing material 50 is formed so as to cover the other surface and the side surface of the semiconductor element 20.
In the present embodiment, the sealing material 50 is composed of a cured product of the above-mentioned sealing resin composition. Therefore, the semiconductor device 100 has excellent insulating characteristics. Further, in the semiconductor device 100, the dispersibility of the component (C) in the encapsulating material 50 is excellent, so that the bias of the material in the encapsulating material 50 is suppressed.
The encapsulating material 50 can be formed, for example, by encapsulating the encapsulating resin composition using a known method such as a transfer molding method or a compression molding method.

FIG. 2 is a cross-sectional view showing the configuration of the semiconductor device 100 according to the present embodiment, and shows an example different from FIG. The semiconductor device 100 shown in FIG. 2 is specifically a power module and uses a lead frame as the substrate 30. In this case, the semiconductor element 20 is mounted on the die pad 32 of the substrate 30, for example, and is electrically connected to the outer lead 34 via the wire 40. The semiconductor element 20 is specifically a power semiconductor element, similarly to the example shown in FIG. Moreover, the sealing material 50 is configured by a cured product of the sealing resin composition in the present embodiment, similarly to the example illustrated in FIG. 1.

In the semiconductor device shown in FIGS. 1 and 2, the semiconductor element 20 is a power semiconductor element that satisfies any of the above conditions (i) to (iv). The material of the semiconductor device 20 is preferably one or more semiconductors selected from the group consisting of SiC, GaN, Ga ₂ O ₃ and diamond under the condition (ii) described above.
Further, the power consumption of the semiconductor element 20 is, for example, 2.0 W or more, preferably 3.0 W or more, which is the above-mentioned condition (i), and may be 4.0 W or less, for example.
The voltage of the semiconductor element 20 is, for example, 1.0 V or more, preferably 3.0 V or more, which is the above-mentioned condition (iii), and may be 5.0 V or more, for example, 20 V or more. Good. The voltage of the semiconductor element 20 may be, for example, 2000 V or less, or may be 100 V or less.
The power density of the semiconductor element 20 is, for example, 10 W/cm ³ or more under the above-mentioned condition (iv), preferably 20 W/cm ³ or more, and may be 30 W/cm ³ or more, for example. The power density of the semiconductor element 20 may be, for example, 200 W/cm ³ or less.
Further, the semiconductor device 20 can operate in a high temperature environment of, for example, 200° C. or higher, preferably 260° C. or higher.

Examples of the semiconductor element 20 include, but are not limited to, an integrated circuit, a large scale integrated circuit, a transistor, a thyristor, a diode, a solid-state image sensor, and the like. In the present embodiment, the semiconductor element to be sealed with the sealing resin composition is a so-called element that does not involve the entry and exit of light, except an optical semiconductor element such as a light receiving element and a light emitting element (light emitting diode, etc.). Say.
The semiconductor element 20 is preferably a power semiconductor element provided on the substrate 30, and includes a rectifying diode, a power transistor, a power MOSFET, an insulated gate bipolar transistor (IGBT), a thyristor, a gate turn-off thyristor (GTO) and a triac. It includes one or more electronic components selected from the group.

The embodiments of the present invention have been described above, but these are examples of the present invention, and various configurations other than the above can be adopted.

Hereinafter, the present embodiment will be described in detail with reference to examples and comparative examples. The present embodiment is not limited to the description of these examples.

(Examples 1 to 6, Comparative Examples 1 to 6)
(Preparation of sealing resin composition)
The encapsulating resin composition was prepared as follows for each of the examples and the comparative examples.
First, the components shown in Table 1 were mixed with a mixer. Next, the obtained mixture was kneaded with a roll, cooled, and pulverized to obtain a sealing resin composition which was a granular material.

Details of each component in Table 1 are as follows. Moreover, the compounding ratio of each component shown in Table 1 has shown the compounding ratio (mass part) with respect to the whole resin composition.
(material)
(Epoxy resin)
Epoxy resin 1: Phenol aralkyl type epoxy resin having a biphenylene skeleton (Nippon Kayaku Co., Ltd., NC3000L)
Epoxy resin 2: cresol novolac type epoxy resin (NDC, YDCN-800-70)
Epoxy resin 3: Bisphenol A type epoxy resin (YL6810 manufactured by Mitsubishi Chemical Corporation)
Epoxy resin 4: Biphenyl type epoxy resin (YX4000H manufactured by Japan Epoxy Resins Co., Ltd.)
(Curing agent)
Curing agent 1: Phenol aralkyl resin having a biphenylene skeleton (manufactured by Nippon Kayaku Co., Ltd., GPH-65)
Hardener 2: Phenol novolac resin (Sumitomo Bakelite Co., PR-HF-3)
(Inorganic filler)
Inorganic filler 1: fused spherical silica (manufactured by Denki Kagaku Kogyo Co., Ltd., FB-950FC, d ₅₀ : 22 μm)
Inorganic filler 2: synthetic spherical silica (manufactured by Admatechs, SO-E2, d ₅₀ : 0.5 μm, specific surface area 6.0 m ² /g)
Inorganic filler 3: crushed silica (Fumitec, F-115, d ₅₀ : 13 μm)
(Ion trap)
Ion scavenger 1: hydrotalcite (Kyowa Chemical Co., Ltd., DHT-4H)
(Colorant)
Colorant 1: acetylene black (manufactured by Denka, Li-400, average particle size d ₅₀ of secondary particles: 2 μm, metal content: 10 ppm or less, SO ₄ ^2- ion content: less than 1 ppm, nitrogen adsorption specific surface area) : 50m ² /g)
Colorant 2: Carbon black (Mitsubishi Chemical Co., carbon #5)
(Coupling agent)
Coupling agent 1: Phenylaminopropyltrimethoxysilane (Toray Dow Corning CF4083)
(Release agent)
Release agent 1: Carnauba wax (Nikko Fine Carnauba, manufactured by Nikko Fine Co., Ltd.)
(Low stress agent)
Low stress agent 1: acrylonitrile butadiene copolymer compound (PTBN Japan Co., CTBN1008SP)

(Evaluation)
An evaluation sample was prepared by the following method using the resin composition obtained in each example, and the insulation resistance of the obtained sample was evaluated by a high temperature reverse bias (HTRB) test.

(HTRB test: evaluation of HTRB resistance)
First, an IGBT (insulated gate bipolar transistor) element having a rated voltage of 1200 V was die-bonded to a frame of package specification: TO-247 using solder, and then wire-bonded with an Al wire. This was sealed with the resin composition for encapsulation of Examples or Comparative Examples to prepare a package for HTRB evaluation. The molding condition of the encapsulating resin composition was 175° C. for 2 minutes, and the after-curing condition was 175° C. for 4 hours.
The evaluation sample of each example obtained by the above-mentioned method was processed by an HTRB tester at a temperature of 150° C. and a voltage of 1200 V for 1000 hours. The withstand voltage before and after the treatment was measured and evaluated according to the following criteria.
◯: Decrease rate of withstand voltage after treatment is less than 5% with respect to withstand voltage before treatment ×: Decrease rate of withstand voltage after treatment is 5% or more relative to withstand voltage before treatment

From Table 1, the cured product of the encapsulating resin composition obtained in each Example was superior in insulating property to that of each Comparative Example.

20 semiconductor element 30 substrate 32 die pad 34 outer lead 40 wire 50 encapsulant 60 solder ball 100 semiconductor device

Claims (7)

The following components (A) to (C):
(A) Epoxy resin,
A resin composition for encapsulation, which comprises (B) an inorganic filler and (C) acetylene black and is used for encapsulating a power semiconductor element satisfying any of the following conditions (i) to (iv).
(I) Semiconductor element with power consumption of 2.0 W or more (ii) Semiconductor element made of one or more semiconductors selected from the group consisting of SiC, GaN, Ga ₂ O ₃ and diamond (iii) Voltage is 1.0 V or more Semiconductor device (iv) Semiconductor device with power density of 10 W/cm ³ or more The encapsulating resin composition according to claim 1, wherein the component (B) contains crushed silica. The encapsulating resin composition according to claim 1, further comprising a low stress agent. The encapsulating resin composition according to any one of claims 1 to 3, wherein the content of the metal in the component (C) measured by the following method is 10 ppm or less.
(Measurement method) The sample of the component (C) is passed through a sieve having an opening of 75 μm to obtain a fraction under the sieve. The content of the metal in the fraction under the sieve is measured by the inductively coupled high frequency plasma emission spectroscopy, and the content of the metal is determined. The encapsulating resin composition according to any one of claims 1 to 4, wherein the content of SO ₄ ^2- ions in the component (C) measured by the following method by ion chromatography is 2 ppm or less. ..
(Measurement method) A sample of the component (C) is placed in a combustion decomposition unit, burned in a combustion gas stream containing oxygen, and the generated gas is collected in an absorbing liquid (hydrogen peroxide aqueous solution). The SO ₄ ²⁻ ions collected in the absorption liquid are separated and quantified by ion chromatography. The encapsulating resin composition according to claim 1, wherein the nitrogen adsorption specific surface area of the component (C) measured by the following method is 30 m ² /g or more and 150 m ² /g or less.
(Measurement method) After degassing the sample of the component (C), it was immersed in liquid nitrogen, the amount of nitrogen adsorbed on the carbon surface at equilibrium was measured by the BET method, and the specific surface area (m ² /g) is calculated. A power module in which a power semiconductor element satisfying any one of the conditions (i) to (iv) is encapsulated with the cured product of the encapsulating resin composition according to any one of claims 1 to 6.

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