Encapsulating resin composition, method for producing encapsulating resin composition, semiconductor device, and method for producing semiconductor device

Abstract

A encapsulating resin composition that satisfies at least one of the following conditions (1) to (3). (1) Contains epoxy resin and an inorganic filler, wherein the specific surface area of ​​the inorganic filler is 3.28 m² 2 It is less than / g. (2) Contains epoxy resin, inorganic filler, and silane coupling agent having -NH2 or -SH. (3) Contains epoxy resin and inorganic filler, and has a crosslinking density of 0.9 mol / cm³ in the cured state. 3 The following or 1.0 mol / cm³ 3 That's all.

Description

[Technical field]

[0001] The present invention relates to an encapsulating resin composition, a method for producing the encapsulating resin composition, a semiconductor device, and a method for producing a semiconductor device. [Background technology]

[0002] Power semiconductor elements are a type of semiconductor element that are mainly used for controlling the voltage or frequency of electric power, converting DC to AC or AC to DC, etc., and are used in various fields that use electric power as a power source, such as electronic devices, motors, and power generation devices. For this reason, semiconductor devices (power semiconductor devices) equipped with power semiconductor elements are required to have electrical reliability that can withstand use under high voltage and large current conditions. For example, it is required that the leakage current generated in a high temperature reverse bias test (HTRB) is sufficiently small (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-45747 A Summary of the Invention [Problem to be solved by the invention]

[0004] Resin compositions containing epoxy resins such as epoxy resins are widely used as encapsulating resin compositions for encapsulating power semiconductor elements. In order to improve the electrical reliability of power semiconductor devices, studies on resin compositions suitable for encapsulating power semiconductor elements have been conducted from the viewpoints of glass transition temperature, impurity content, etc., but there are some aspects that cannot be explained by these properties. In view of the above circumstances, an object of the present invention is to provide an encapsulating resin composition capable of producing a semiconductor device having excellent electrical reliability, a method for producing an encapsulating resin composition, and a semiconductor device and a method for producing a semiconductor device using the same. [Means for solving the problem]

[0005] Means for solving the above problems include the following embodiments. <1> The epoxy resin and the inorganic filler are contained, and the specific surface area of ​​the inorganic filler is 3.28 m 2 / g or less. <2> The dielectric relaxation value measured at a frequency of 0.001 Hz in the cured state is 20 or less. <1> The encapsulating resin composition according to claim 1 . <3> Epoxy resin, inorganic filler, and -NH 2 or a silane coupling agent having -SH. <4> The dielectric relaxation value measured at a frequency of 0.001 Hz in the cured state is 13 or less. <3> The encapsulating resin composition according to claim 1 . <5> It contains epoxy resin and inorganic filler, and has a crosslink density of 0.9 mol / cm in the cured state. 3 or less, or 1.0 mol / cm 3 The above is the encapsulating resin composition. <6> The dielectric relaxation value measured at a frequency of 0.001 Hz in the cured state is 20 or less. <5> The encapsulating resin composition according to claim 1 . <7> Used to seal power semiconductor elements. <1> ~ <6> 13. The encapsulating resin composition according to claim 12. <8> The content of the inorganic filler is 70% by volume or more of the encapsulating resin composition. <1> ~ <7> 13. The encapsulating resin composition according to claim 12. <9> The crosslink density in the cured state is 0.9 mol / cm 3 or less, or 1.0 mol / cm 3 The control step includes the steps of: <1> ~ <8> 13. A method for producing the encapsulating resin composition according to claim 12. <10> A support, a semiconductor element disposed on the support, and a semiconductor element encapsulated therein. <1> ~ <8> 13. A semiconductor device comprising: a cured product of the encapsulating resin composition according to claim 12. <11> disposing a semiconductor element on a support; <1> ~ <8> and encapsulating the semiconductor device with the encapsulating resin composition according to any one of claims 1 to 5. Effect of the Invention

[0006] According to the present invention, there are provided an encapsulating resin composition capable of producing a semiconductor device having excellent electrical reliability, a method for producing an encapsulating resin composition, a semiconductor device using the same, and a method for producing a semiconductor device. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram showing an example of the configuration of a dielectric relaxation measuring device. [Diagram 2] FIG. 2 is a scatter diagram showing the correlation between the specific surface area and the dielectric relaxation value (frequency: 0.001 Hz) of an inorganic filler contained in an encapsulating resin composition produced in an example (first embodiment). [Diagram 3] FIG. 11 is a scatter diagram showing the correlation between the crosslink density and the dielectric relaxation value of the encapsulating resin composition produced in the example (third embodiment). [Figure 4] FIG. 1 is a scatter diagram showing the correlation between the dielectric relaxation value (frequency: 0.001 Hz) of the encapsulating resin composition prepared in the reference example and the high-temperature reverse bias test result. [Diagram 5] FIG. 1 is a scatter diagram showing the correlation between the dielectric relaxation value (at a frequency of 1 MHz) of the encapsulating resin composition prepared in the reference example and the result of a high-temperature reverse bias test. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, the embodiment for carrying out the present invention will be described in detail. However, the present invention is not limited to the following embodiment. In the following embodiment, the components (including element steps, etc.) are not essential unless specifically stated. The same applies to the numerical values ​​and their ranges, and they do not limit the present invention.

[0009] In the present disclosure, the term "step" includes not only a step that is independent of other steps, but also a step that cannot be clearly distinguished from other steps as long as the purpose of the step is achieved. In the present disclosure, a numerical range indicated using "~" includes the numerical values ​​before and after "~" as the minimum and maximum values, respectively. In the numerical ranges described in the present disclosure in stages, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. In addition, in the numerical ranges described in the present disclosure, the upper or lower limit value of the numerical range may be replaced with a value shown in the examples. In the present disclosure, each component may contain multiple types of the corresponding substance. When multiple substances corresponding to each component are present in the composition, the content or amount of each component means the total content or amount of the multiple substances present in the composition, unless otherwise specified. In the present disclosure, the particles corresponding to each component may include multiple types. When multiple types of particles corresponding to each component are present in the composition, the particle size of each component means the value for a mixture of the multiple types of particles present in the composition, unless otherwise specified.

[0010] <Encapsulating resin composition (first embodiment)> The encapsulating resin composition of the present embodiment contains an epoxy resin and an inorganic filler, and the inorganic filler has a specific surface area of ​​3.28 m 2 / g or less.

[0011] As a result of the study by the present inventors, it was found that there is a correlation between the specific surface area of ​​the inorganic filler contained in the encapsulating resin composition and the dielectric relaxation value measured at 0.001 Hz in the cured state of the encapsulating resin composition. Although the reason for this is not entirely clear, it is speculated that this is because the number of hydroxyl groups present on the surface of the inorganic filler changes depending on the specific surface area, and this is involved in the increase or decrease in the dielectric relaxation value measured at low frequencies.

[0012] Further study based on the above findings revealed that the smaller the dielectric relaxation value of the encapsulating resin composition measured at 0.001 Hz in the cured state, the smaller the leakage current generated in a high-temperature reverse bias test of a semiconductor device using the composition, and the more excellent the electrical reliability.

[0013] In this embodiment, the specific surface area of ​​the inorganic filler is a value measured by the BET method.

[0014] In the present embodiment, the dielectric relaxation value measured in the cured state of the encapsulating resin composition is a value measured by low-frequency dielectric constant measurement. From the viewpoint of electrical reliability of the semiconductor device, the dielectric relaxation value measured at a frequency of 0.001 Hz is preferably 20 or less, more preferably 17 or less, even more preferably 15 or less, and particularly preferably 13 or less.

[0015] It is believed that the dielectric relaxation value measured in the cured state of the encapsulating resin composition decreases as the amount of inorganic filler increases (for example, 70 volume % or more of the entire encapsulating resin composition). On the other hand, increasing the amount of inorganic filler tends to cause problems such as difficulty in kneading and reduced dispersibility. According to this embodiment, the dielectric relaxation value measured at a frequency of 0.001 Hz can be controlled by adjusting the specific surface area of ​​the inorganic filler. Therefore, it can be expected that the effect of improving electrical reliability will be achieved regardless of the increase in the amount of inorganic filler.

[0016] The encapsulating resin composition of the present embodiment may contain the silane coupling agent defined in the second embodiment, and may satisfy the condition of the crosslink density defined in the third embodiment.

[0017] <Sealing resin composition (second embodiment)> The encapsulating resin composition of the present embodiment includes an epoxy resin, an inorganic filler, and a -NH 2 Or, it contains a silane coupling agent having -SH. -NH 2Examples of the silane coupling agent having the formula include N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, and 3-aminopropyltriethoxysilane. Examples of the silane coupling agent having --SH include 3-mercaptopropylmethyldimethoxysilane and 3-mercaptopropyltrimethoxysilane. The coupling agent is -NH 2 Alternatively, a coupling agent other than the silane coupling agent having --SH may be used in combination.

[0018] As a result of the investigations by the present inventors, -NH 2 It has been found that encapsulating resin compositions containing a silane coupling agent having -NH or -SH tend to have smaller dielectric relaxation values ​​measured at a frequency of 0.001 Hz than encapsulating resin compositions containing a silane coupling agent having other functional groups. 2 It is also speculated that -SH has a higher reactivity with the epoxy groups of the epoxy resin than other functional groups, and thus has a greater effect of suppressing the molecular motion of the epoxy resin.

[0019] Further study based on the above findings revealed that the smaller the dielectric relaxation value of an encapsulating resin composition measured at 0.001 Hz in a cured state, the smaller the leakage current generated in a high-temperature reverse bias test of a semiconductor device using the composition, and the more excellent the electrical reliability.

[0020] In this embodiment, the dielectric relaxation value measured when the encapsulating resin composition is in a cured state is a value measured by low frequency dielectric constant measurement. From the viewpoint of electrical reliability of the semiconductor device, the dielectric relaxation value of the encapsulating resin composition measured at a frequency of 0.001 Hz is preferably 20 or less, more preferably 15 or less, and even more preferably 13 or less. In addition, the maximum dielectric relaxation value obtained between frequencies of 0 Hz and 0.01 Hz is preferably 40 or less, more preferably 30 or less, and even more preferably 20 or less.

[0021] It is believed that the dielectric relaxation value of the encapsulating resin composition decreases as the amount of inorganic filler increases (for example, 70% by volume or more of the entire encapsulating resin composition). On the other hand, an increase in the amount of inorganic filler tends to cause problems such as difficulty in kneading and reduced dispersibility. According to this embodiment, the dielectric relaxation value measured at a frequency of 0.001 Hz can be controlled by using a silane coupling agent having a specific substituent. Therefore, it can be expected that the effect of improving electrical reliability can be achieved regardless of the increase in the amount of inorganic filler.

[0022] It is known that the dielectric tangent value of an encapsulating resin composition is reduced by surface treating an inorganic filler with a silane coupling agent having a glycidyl group (see, for example, JP-A-9-194690). However, there have been no reports so far about its contribution to the dielectric constant in the low frequency range.

[0023] The encapsulating resin composition of the present embodiment may satisfy the conditions for the inorganic filler specified in the first embodiment, and may satisfy the conditions for the crosslink density specified in the third embodiment.

[0024] <Sealing resin composition (third embodiment)> The encapsulating resin composition of the present embodiment contains an epoxy resin and an inorganic filler, and has a crosslink density of 0.9 mol / cm in a cured state. 3 or less, or 1.0 mol / cm 3 That's all.

[0025] The semiconductor device manufactured using the encapsulating resin composition of this embodiment has excellent electrical reliability. When the reason for this was investigated, a correlation was found between the crosslink density of the encapsulating resin composition in a cured state (hereinafter also simply referred to as "crosslink density". The unit of crosslink density may also be referred to as mol / cc) and the dielectric relaxation value measured at a frequency of 0.001 Hz. Specifically, when the crosslink density of the encapsulating resin composition is 0.9 mol / cm 3 In the following range, as the crosslink density increases, the dielectric relaxation value measured at a frequency of 0.001 Hz tends to increase, and 3 It was found that within the above range, the dielectric relaxation value measured at a frequency of 0.001 Hz tends to decrease as the crosslink density increases.

[0026] The reason for the above-mentioned correlation between the crosslink density of the encapsulating resin composition and the dielectric relaxation value measured at a frequency of 0.001 Hz is not entirely clear, but it is presumed that the higher the crosslink density, the more the dipole motion tends to be suppressed, while the higher the crosslink density, the more the dipole amount tends to increase.

[0027] Furthermore, the inventors' studies have revealed that a semiconductor device using an encapsulating resin composition having a sufficiently small dielectric relaxation value measured at a frequency of 0.001 Hz in a cured state generates sufficiently small leakage current in a high-temperature reverse bias test and has excellent electrical reliability.

[0028] From the above, it is believed that the encapsulating resin composition of the present disclosure has a crosslink density within a specific range, thereby keeping the dielectric relaxation value measured at a frequency of 0.001 Hz low, making it possible to produce a semiconductor device with excellent electrical reliability.

[0029] In the present disclosure, the crosslink density of the encapsulating resin composition is a value calculated in accordance with the following formula using the dynamic storage modulus of the rubber region determined by a dynamic viscoelasticity measuring device.

[0030] Calculation formula: n=E' / 3RT n: Crosslink density [mol / cm3 ] E': Dynamic storage modulus [Pa] R: Gas constant 8.31 [J / mol K] T: Absolute temperature [K]

[0031] The lower limit of the crosslink density of the encapsulating resin composition is not particularly limited, but from the viewpoint of curability, it is preferably 0.3 mol / cm 3 More preferably, it is equal to or greater than this. The upper limit of the crosslink density of the encapsulating resin composition is not particularly limited, but from the viewpoint of temperature cycles, it is preferably 3.0 mol / cm 3 It is preferable that:

[0032] In this embodiment, the dielectric relaxation value measured when the encapsulating resin composition is in a cured state is a value measured by the low frequency dielectric constant. From the viewpoint of electrical reliability of the semiconductor device, the dielectric relaxation value measured when the encapsulating resin composition is in a cured state at a frequency of 0.001 Hz is preferably 20 or less, more preferably 16 or less. In addition, the maximum dielectric relaxation value measured between frequencies of 0 Hz and 0.01 Hz is preferably 40 or less, more preferably 16 or less.

[0033] It is believed that the dielectric relaxation value of the encapsulating resin composition decreases as the amount of inorganic filler increases (for example, 70 volume % or more of the entire encapsulating resin composition). On the other hand, an increase in the amount of inorganic filler tends to cause problems such as difficulty in kneading and reduced dispersibility. According to the present disclosure, the dielectric relaxation value can be controlled by adjusting the crosslink density of the encapsulating resin composition. Therefore, an effect of improving electrical reliability can be expected regardless of an increase in the amount of inorganic filler.

[0034] The encapsulating resin composition of the present embodiment may satisfy the conditions of the inorganic filler defined in the first embodiment, and may contain the coupling agent defined in the second embodiment.

[0035] (Epoxy resin) The type of epoxy resin contained in the encapsulating resin composition is not particularly limited, and can be selected from those generally used in encapsulating resin compositions. Specifically, the novolac type epoxy resins include novolac resins (phenol novolac type epoxy resins, orthocresol novolac type epoxy resins, etc.) obtained by epoxidizing novolac resins obtained by condensing or co-condensing at least one phenolic compound selected from the group consisting of phenolic compounds such as phenol, cresol, xylenol, resorcin, catechol, bisphenol A, bisphenol F, etc., and naphthol compounds such as α-naphthol, β-naphthol, dihydroxynaphthalene, etc., with an aliphatic aldehyde compound such as formaldehyde, acetaldehyde, propionaldehyde, etc., under an acid catalyst; triphenylmethane type epoxy resins obtained by epoxidizing triphenylmethane type phenolic resins obtained by condensing or co-condensing the above phenolic compound with an aromatic aldehyde compound such as benzaldehyde, salicylaldehyde, etc., under an acid catalyst; and novolac resins obtained by co-condensing the above phenolic compound and naphthol compound with an aldehyde compound under an acid catalyst, which are epoxy resins. diphenylmethane type epoxy resins which are diglycidyl ethers of bisphenol A, bisphenol F, etc.; biphenyl type epoxy resins which are diglycidyl ethers of alkyl-substituted or unsubstituted biphenols; stilbene type epoxy resins which are diglycidyl ethers of stilbene-based phenolic compounds; sulfur-containing epoxy resins which are diglycidyl ethers of bisphenol S, etc.; epoxy resins which are glycidyl ethers of alcohols such as butanediol, polyethylene glycol, and polypropylene glycol; glycidyl ester type epoxy resins which are glycidyl esters of polyvalent carboxylic acids such as phthalic acid, isophthalic acid, and tetrahydrophthalic acid; glycidylamine type epoxy resins in which active hydrogen bonded to nitrogen atoms of aniline, diaminodiphenylmethane, isocyanuric acid, etc. is replaced with a glycidyl group; dicyclopentadiene type epoxy resins which are epoxidized co-condensation resins of dicyclopentadiene and phenolic compounds;Alicyclic epoxy resins such as vinylcyclohexene diepoxide, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, and 2-(3,4-epoxy)cyclohexyl-5,5-spiro(3,4-epoxy)cyclohexane-m-dioxane, which are epoxy-modified epoxy resins in which the olefin bonds in the molecule have been epoxidized; paraxylylene-modified epoxy resins, which are glycidyl ethers of paraxylylene-modified phenolic resins; metaxylylene-modified epoxy resins, which are glycidyl ethers of metaxylylene-modified phenolic resins; terpene-modified epoxy resins, which are glycidyl ethers of terpene-modified phenolic resins; and dicyclopentadiene-modified phenolic resins, which are glycidyl ethers of dicyclopentadiene-modified phenolic resins. Examples of the epoxy resin include pentadiene-modified epoxy resins; cyclopentadiene-modified epoxy resins which are glycidyl ethers of cyclopentadiene-modified phenolic resins; polycyclic aromatic ring-modified epoxy resins which are glycidyl ethers of polycyclic aromatic ring-modified phenolic resins; naphthalene-type epoxy resins which are glycidyl ethers of naphthalene ring-containing phenolic resins; halogenated phenol novolac-type epoxy resins; hydroquinone-type epoxy resins; trimethylolpropane-type epoxy resins; linear aliphatic epoxy resins obtained by oxidizing olefin bonds with peracids such as peracetic acid; aralkyl-type epoxy resins obtained by epoxidizing aralkyl-type phenolic resins such as phenol aralkyl resins and naphthol aralkyl resins; and the like. Furthermore, examples of the epoxy resin include epoxidized silicone resins and epoxidized acrylic resins. These epoxy resins may be used alone or in combination of two or more.;

[0036] The epoxy equivalent (molecular weight / number of epoxy groups) of the epoxy resin is not particularly limited, but from the viewpoint of the balance of various properties such as moldability, reflow resistance, and electrical reliability, it is preferably 100 g / eq to 1000 g / eq, and more preferably 150 g / eq to 500 g / eq.

[0037] The epoxy equivalent of the epoxy resin is a value measured by a method conforming to JIS K 7236:2009.

[0038] When the epoxy resin is solid, its softening point or melting point is not particularly limited, but is preferably 40°C to 180°C from the viewpoints of moldability and reflow resistance, and more preferably 50°C to 130°C from the viewpoint of handleability during preparation of the encapsulating resin composition.

[0039] The melting point of the epoxy resin is a value measured by differential scanning calorimetry (DSC), and the softening point of the epoxy resin is a value measured by a method conforming to JIS K 7234:1986 (ring and ball method).

[0040] The content of the epoxy resin in the encapsulating resin composition is preferably 0.5% by mass to 50% by mass, and more preferably 2% by mass to 30% by mass, from the viewpoints of strength, flowability, heat resistance, moldability, and the like.

[0041] (hardening agent) The encapsulating resin composition may contain a curing agent. The type of the curing agent is not particularly limited, and examples thereof include phenol curing agents, amine curing agents, acid anhydride curing agents, polymercaptan curing agents, polyaminoamide curing agents, isocyanate curing agents, and blocked isocyanate curing agents. From the viewpoint of improving heat resistance, those having two or more phenolic hydroxyl groups in one molecule (phenol curing agents) are preferred.

[0042] Specific examples of the phenolic hardener include polyhydric phenolic compounds such as resorcin, catechol, bisphenol A, bisphenol F, and substituted or unsubstituted biphenol; novolak-type phenolic resins obtained by condensing or co-condensing at least one phenolic compound selected from the group consisting of phenolic compounds such as phenol, cresol, xylenol, resorcin, catechol, bisphenol A, bisphenol F, phenylphenol, and aminophenol, and naphthol compounds such as α-naphthol, β-naphthol, and dihydroxynaphthalene, with an aldehyde compound such as formaldehyde, acetaldehyde, propionaldehyde, benzaldehyde, and salicylaldehyde, under an acid catalyst; and polyphenolic compounds such as dimethoxyparaxylene, bis(methoxymethyl)biphenol, and the like. Examples of the phenol curing agent include aralkyl-type phenolic resins such as phenol aralkyl resins and naphthol aralkyl resins synthesized from phenyl and the like; phenolic resins modified with paraxylylene or metaxylylene; melamine-modified phenolic resins; terpene-modified phenolic resins; dicyclopentadiene-type phenolic resins and dicyclopentadiene-type naphthol resins synthesized by copolymerization of the above-mentioned phenolic compounds and dicyclopentadiene; cyclopentadiene-modified phenolic resins; polycyclic aromatic ring-modified phenolic resins; biphenyl-type phenolic resins; triphenylmethane-type phenolic resins obtained by condensing or co-condensing the above-mentioned phenolic compounds with aromatic aldehyde compounds such as benzaldehyde and salicylaldehyde under an acid catalyst; and phenolic resins obtained by copolymerizing two or more of these. These phenolic curing agents may be used alone or in combination of two or more.

[0043] The functional group equivalent of the curing agent (hydroxyl group equivalent in the case of a phenolic curing agent) is not particularly limited. From the viewpoint of the balance of various properties such as moldability, reflow resistance, and electrical reliability, it is preferably 70 g / eq to 1000 g / eq, and more preferably 80 g / eq to 500 g / eq.

[0044] The functional group equivalent of the curing agent (hydroxyl group equivalent in the case of a phenolic curing agent) is a value measured by a method in accordance with JIS K 0070:1992.

[0045] When the curing agent is a solid, its softening point or melting point is not particularly limited, but is preferably 40° C. to 180° C. from the viewpoints of moldability and reflow resistance, and more preferably 50° C. to 130° C. from the viewpoint of handleability during production of the encapsulating resin composition.

[0046] The melting point or softening point of the curing agent is a value measured in the same manner as the melting point or softening point of the epoxy resin.

[0047] The compounding ratio of the epoxy resin and the curing agent is not particularly limited. From the viewpoint of keeping the amount of each unreacted small, the ratio of the number of functional groups of the curing agent to the number of epoxy groups of the epoxy resin (number of epoxy groups of the epoxy resin / number of functional groups of the curing agent) is preferably set to be in the range of 0.5 to 2.0, more preferably set to be in the range of 0.6 to 1.3, and further preferably set to be in the range of 0.8 to 1.2.

[0048] (Cure accelerator) The encapsulating resin composition may contain a curing accelerator. The type of the curing accelerator is not particularly limited and can be selected depending on the type of epoxy resin, the desired properties of the encapsulating resin composition, and the like. Examples of the curing accelerator include diazabicycloalkenes such as 1,5-diazabicyclo[4.3.0]nonene-5 (DBN) and 1,8-diazabicyclo[5.4.0]undecene-7 (DBU), cyclic amidine compounds such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, and 2-heptadecylimidazole; derivatives of the cyclic amidine compounds; phenol novolac salts of the cyclic amidine compounds or their derivatives; and combinations of these compounds with maleic anhydride, 1,4-benzoquinone, 2,5-toluquinone, 1,4-naphthoquinone, and the like. quinone compounds such as quinone, 2,3-dimethylbenzoquinone, 2,6-dimethylbenzoquinone, 2,3-dimethoxy-5-methyl-1,4-benzoquinone, 2,3-dimethoxy-1,4-benzoquinone, and phenyl-1,4-benzoquinone; compounds with intramolecular polarization formed by adding compounds with π bonds such as diazophenylmethane; cyclic amidines such as tetraphenylborate salt of DBU, tetraphenylborate salt of DBN, tetraphenylborate salt of 2-ethyl-4-methylimidazole, and tetraphenylborate salt of N-methylmorpholine; ammonium compounds; tertiary amine compounds such as pyridine, triethylamine, triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris(dimethylaminomethyl)phenol; derivatives of the above tertiary amine compounds; ammonium salt compounds such as tetra-n-butylammonium acetate, tetra-n-butylammonium phosphate, tetraethylammonium acetate, tetra-n-hexylammonium benzoate, and tetrapropylammonium hydroxide; tertiary phosphines such as triphenylphosphine, diphenyl(p-tolyl)phosphine, tris(alkylphenyl)phosphine, tris(alkoxyphenyl)phosphine, tris(alkylalkoxyphenyl)phosphine, tris(dialkylphenyl)phosphine, tris(trialkylphenyl)phosphine, tris(tetraalkylphenyl)phosphine, tris(dialkoxyphenyl)phosphine, tris(trialkoxyphenyl)phosphine, tris(tetraalkoxyphenyl)phosphine, trialkylphosphine, dialkylarylphosphine, and alkyldiarylphosphine;Phosphine compounds such as complexes of the tertiary phosphines and organic borons; compounds having intramolecular polarization obtained by adding the tertiary phosphines or the phosphine compounds to maleic anhydride, quinone compounds such as 1,4-benzoquinone, 2,5-toluquinone, 1,4-naphthoquinone, 2,3-dimethylbenzoquinone, 2,6-dimethylbenzoquinone, 2,3-dimethoxy-5-methyl-1,4-benzoquinone, 2,3-dimethoxy-1,4-benzoquinone, and phenyl-1,4-benzoquinone, and compounds having a π bond such as diazophenylmethane; compounds having intramolecular polarization obtained by adding the tertiary phosphines or the phosphine compounds to 4-bromophenol, 3-bromophenol, 2-bromophenol, 4-chlorophenol, 3-chlorophenol, 2-chlorophenol, 4-iodophenol, and 3-iodophenol; Compounds having intramolecular polarization obtained by reacting halogenated phenol compounds such as phenol, 2-iodophenol, 4-bromo-2-methylphenol, 4-bromo-3-methylphenol, 4-bromo-2,6-dimethylphenol, 4-bromo-3,5-dimethylphenol, 4-bromo-2,6-di-tert-butylphenol, 4-chloro-1-naphthol, 1-bromo-2-naphthol, 6-bromo-2-naphthol, and 4-bromo-4'-hydroxybiphenyl, followed by a dehydrohalogenation step; tetra-substituted phosphonium compounds such as tetraphenylphosphonium, tetra-substituted phosphonium compounds and tetra-substituted borates having no phenyl group bonded to the boron atom such as tetra-p-tolylborate, and salts of tetraphenylphosphonium compounds with phenol compounds;

[0049] When the encapsulating resin composition contains a curing accelerator, the amount is preferably 0.1 to 30 parts by mass, more preferably 1 to 15 parts by mass, per 100 parts by mass of the resin component (total of the epoxy resin and the curing agent contained as necessary, the same applies below). When the amount of the curing accelerator is 0.1 parts by mass or more per 100 parts by mass of the resin component, the composition tends to cure well in a short time. When the amount of the curing accelerator is 30 parts by mass or less per 100 parts by mass of the resin component, the curing speed is not too fast and a good molded product tends to be obtained.

[0050] (Inorganic filler) The type of inorganic filler contained in the encapsulating resin composition is not particularly limited.Specific examples of inorganic materials include fused silica, crystalline silica, glass, alumina, calcium carbonate, zirconium silicate, calcium silicate, silicon nitride, aluminum nitride, boron nitride, beryllia, zirconia, zircon, fosterite, steatite, spinel, mullite, titania, talc, clay, and mica.An inorganic filler having a flame retardant effect may be used.Examples of inorganic fillers having a flame retardant effect include aluminum hydroxide, magnesium hydroxide, composite metal hydroxide such as composite hydroxide of magnesium and zinc, and zinc borate.

[0051] Among the inorganic fillers, silica such as fused silica is preferred from the viewpoint of reducing the linear expansion coefficient, and alumina is preferred from the viewpoint of high thermal conductivity. The inorganic fillers may be used alone or in combination of two or more kinds.

[0052] The content of the inorganic filler in the encapsulating resin composition is not particularly limited. From the viewpoint of fluidity and strength, it is preferably 30% by volume to 90% by volume, more preferably 50% by volume to 85% by volume, of the entire encapsulating resin composition. When the content of the inorganic filler is 30% by volume or more of the entire encapsulating resin composition, the properties such as the thermal expansion coefficient, thermal conductivity, and elastic modulus of the cured product tend to be further improved. When the content of the inorganic filler is 90% by volume or less of the entire encapsulating resin composition, the increase in viscosity of the encapsulating resin composition is suppressed, and the fluidity is further improved, tending to improve moldability.

[0053] When the inorganic filler is particulate, its average particle diameter is not particularly limited. For example, the volume average particle diameter of the entire inorganic filler is preferably 0.2 μm to 10 μm, and more preferably 0.5 μm to 5 μm. When the volume average particle diameter is 0.2 μm or more, the increase in viscosity of the encapsulating resin composition tends to be more suppressed. When the volume average particle diameter is 10 μm or less, the filling ability into narrow gaps tends to be more improved. The volume average particle diameter of the inorganic filler can be measured as the volume average particle diameter (D50) by a laser scattering diffraction method particle size distribution measuring device.

[0054] (Coupling Agent) The encapsulating resin composition may contain a coupling agent, such as a known coupling agent including a silane-based compound, such as epoxysilane, mercaptosilane, aminosilane, alkylsilane, ureidosilane, or vinylsilane, a titanium-based compound, an aluminum chelate compound, or an aluminum / zirconium-based compound.

[0055] When the encapsulating resin composition contains a coupling agent, the amount of the coupling agent is preferably 0.05 parts by mass to 5 parts by mass, more preferably 0.1 parts by mass to 2.5 parts by mass, relative to 100 parts by mass of the inorganic filler. When the amount of the coupling agent is 0.05 parts by mass or more relative to 100 parts by mass of the inorganic filler, the adhesion to the frame tends to be improved. When the amount of the coupling agent is 5 parts by mass or less relative to 100 parts by mass of the inorganic filler, the moldability of the package tends to be improved.

[0056] (Ion exchanger) The resin composition for sealing may contain an ion exchanger. In particular, when the resin composition for sealing is used as a molding material for sealing, it is preferably contained an ion exchanger from the viewpoint of improving the moisture resistance and high-temperature storage characteristics of an electronic component device including an element to be sealed. The ion exchanger is not particularly limited, and those conventionally known can be used. Specifically, examples thereof include hydrotalcite compounds and hydrated oxides of at least one element selected from the group consisting of magnesium, aluminum, titanium, zirconium, and bismuth. The ion exchanger may be used alone or in combination of two or more. Among them, hydrotalcite represented by the following general formula (A) is preferable.

[0057] Mg (1-X) Al X (OH) 2 (CO 3 ) X / 2 ·mH 2 O ……(A) (0<X≦0.5, m is a positive number)

[0058] When the resin composition for sealing contains an ion exchanger, its content is not particularly limited as long as it is sufficient to capture ions such as halogen ions. For example, it is preferably 0.1 part by mass to 30 parts by mass, more preferably 1 part by mass to 5 parts by mass with respect to 100 parts by mass of the resin component.

[0059] (Release agent) The resin composition for sealing may contain a release agent from the viewpoint of obtaining good releasability from a mold during molding. The release agent is not particularly limited, and those conventionally known can be used. Specifically, examples thereof include higher fatty acids such as carnauba wax, montanic acid, and stearic acid, higher fatty acid metal salts, ester waxes such as montanic acid esters, and polyolefin waxes such as oxidized polyethylene and non-oxidized polyethylene. The release agent may be used alone or in combination of two or more.

[0060] When the encapsulating resin composition contains a release agent, the amount is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, based on 100 parts by mass of the resin component. When the amount of the release agent is 0.01 parts by mass or more based on 100 parts by mass of the resin component, sufficient releasability tends to be obtained. When the amount is 10 parts by mass or less, better adhesion tends to be obtained.

[0061] (Flame retardant) The encapsulating resin composition may contain a flame retardant. The flame retardant is not particularly limited, and a conventionally known one may be used. Specific examples include organic or inorganic compounds containing halogen atoms, antimony atoms, nitrogen atoms, or phosphorus atoms, metal hydroxides, etc. The flame retardant may be used alone or in combination of two or more.

[0062] When the encapsulating resin composition contains a flame retardant, the amount of the flame retardant is not particularly limited as long as it is an amount sufficient to obtain the desired flame retardant effect. For example, the amount is preferably 1 to 30 parts by mass, more preferably 2 to 15 parts by mass, per 100 parts by mass of the resin component.

[0063] (Coloring agent) The encapsulating resin composition may further contain a colorant. Examples of the colorant include known colorants such as carbon black, organic dyes, organic pigments, titanium oxide, red lead, and red iron oxide. The content of the colorant can be appropriately selected depending on the purpose. The colorant may be used alone or in combination of two or more.

[0064] (Stress reliever) The encapsulating resin composition may contain a stress relaxation agent such as silicone oil and silicone rubber particles. By containing a stress relaxation agent, it is possible to further reduce the warpage deformation of the package and the occurrence of package cracks. Examples of the stress relaxation agent include known stress relaxation agents (flexible agents) that are generally used. Specific examples include thermoplastic elastomers such as silicone-based, styrene-based, olefin-based, urethane-based, polyester-based, polyether-based, polyamide-based, and polybutadiene-based elastomers, rubber particles such as NR (natural rubber), NBR (acrylonitrile-butadiene rubber), acrylic rubber, urethane rubber, and silicone powder, and rubber particles having a core-shell structure such as methyl methacrylate-styrene-butadiene copolymer (MBS), methyl methacrylate-silicone copolymer, and methyl methacrylate-butyl acrylate copolymer. The stress relaxation agent may be used alone or in combination of two or more types.

[0065] (Method for preparing encapsulating resin composition) The method for preparing the encapsulating resin composition is not particularly limited. A typical method is to thoroughly mix a predetermined amount of components with a mixer or the like, then melt-knead with a mixing roll, extruder, or the like, cool, and pulverize. More specifically, for example, a method is to uniformly stir and mix a predetermined amount of the above-mentioned components, knead with a kneader, roll, extruder, or the like that has been heated to 70°C to 140°C in advance, cool, and pulverize.

[0066] The encapsulating resin composition is preferably solid at room temperature and normal pressure (for example, 25° C. and atmospheric pressure). When the encapsulating resin composition is solid, its shape is not particularly limited, and examples thereof include powder, granules, tablets, and the like.

[0067] <Method of producing encapsulating resin composition> The method for producing an encapsulating resin composition according to the present disclosure provides a resin composition having a crosslink density of 0.9 mol / cm in a cured state. 3 or less, or 1.0 mol / cm 3 The control step includes the step of controlling so that the above occurs.

[0068] The crosslink density of the encapsulating resin composition is 0.9 mol / cm 3 Less than or equal to 1.0 mol / cm 3 The method for controlling the crosslink density to be within the above range is not particularly limited. For example, the crosslink density can be controlled to be within the above range by changing the type, content, etc. of each component contained in the encapsulating resin composition.

[0069] According to the above method, it is possible to produce an encapsulating resin composition that enables the production of a semiconductor device having excellent electrical reliability. The details and preferred embodiments of the encapsulating resin composition produced by the above method are as described above as the details and preferred embodiments of the encapsulating resin composition of the present disclosure.

[0070] (Uses of encapsulating resin composition) The application of the encapsulating resin composition is not particularly limited, and it can be used in various semiconductor devices. As described above, the encapsulating resin composition of the present disclosure has excellent electrical reliability when used under high voltage and large current conditions. Therefore, it is particularly suitable for encapsulating power semiconductor elements, but it may also be used for encapsulating semiconductor elements used for calculation, storage, etc.

[0071] <Semiconductor device> The semiconductor device of the present disclosure includes a support, a semiconductor element disposed on the support, and a cured product of the above-described encapsulating resin composition encapsulating the semiconductor element.

[0072] The type of the support and the semiconductor element used in the semiconductor device is not particularly limited, and those generally used in the manufacture of semiconductor devices can be used. The semiconductor device of the present disclosure has excellent electrical reliability when used under high voltage and large current conditions by using the above-mentioned encapsulating resin composition for encapsulating the semiconductor element. Therefore, it is particularly suitable for use as a power semiconductor device, but it may also be a semiconductor device used for calculation, storage, etc.

[0073] <Method of Manufacturing Semiconductor Device> The method for manufacturing a semiconductor device according to the present disclosure includes the steps of placing a semiconductor element on a support and encapsulating the semiconductor element with the encapsulating resin composition described above.

[0074] The method of carrying out each of the above steps is not particularly limited, and can be carried out by a general method. In addition, the type of the support and the semiconductor element used in the manufacture of the semiconductor device is not particularly limited, and those generally used in the manufacture of semiconductor devices can be used. The manufacturing method of the semiconductor device of the present disclosure uses the above-mentioned encapsulating resin composition for encapsulating the semiconductor element, thereby manufacturing a semiconductor device that has excellent electrical reliability when used under high voltage and large current conditions. For this reason, it is particularly suitable as a manufacturing method of a power semiconductor device, but it may also be a manufacturing method of a semiconductor device used for calculation, storage, etc. EXAMPLES

[0075] The above-mentioned embodiment will be specifically described below using examples, but the scope of the present disclosure is not limited to these examples. In addition, unless otherwise specified, "parts" and "%" are based on mass.

[0076] First Embodiment (Preparation of Encapsulating Resin Composition) The following components were mixed in the amounts (unit: parts by mass) shown in Table 1, and roll kneading was carried out under conditions of a kneading temperature of 100° C. and a kneading time of 10 minutes to prepare an encapsulating resin composition.

[0077] [Table 1]

[0078] Details of each material listed in the table are as follows. Epoxy resin: phenol aralkyl type epoxy resin containing a biphenylene skeleton with an epoxy equivalent of 241 and a softening point of 96°C (Nippon Kayaku Co., Ltd., product name CER-3000L) · Hardener: Xylylene-type phenolic resin with a hydroxyl equivalent of 175 and a softening point of 70°C (Meiwa Kasei Co., Ltd., product name MEHC-7800SS) Curing accelerator: betaine-type adduct of triphenylphosphine and 1,4-benzoquinone ·Inorganic filler 1…average particle size 24.3μm, specific surface area 2.86m 2 / g spherical fused silica ·Inorganic filler 2…average particle size 0.13μm, specific surface area 7.00m 2 / g spherical fused silica ·Silane coupling agent: γ-glycidoxypropyltrimethoxysilane

[0079] (Measurement of dielectric relaxation value) The prepared encapsulating resin composition was cured to prepare a test piece for evaluating the dielectric relaxation value. Specifically, the encapsulating resin composition was molded using a transfer molding machine under the conditions of a mold temperature of 180°C, a molding pressure of 6.9 MPa, and a curing time of 120 seconds, and then cured at 175°C for 5 hours. The size of the test piece was a disk with a diameter of 50 mm and a thickness of 1 mm.

[0080] The dielectric relaxation value of the prepared test piece was measured. The measurement was performed using a dielectric relaxation measurement device consisting of a combination of an impedance measurement device having a dielectric constant measurement interface and a dynamic viscoelasticity measurement device as shown in FIG. 1. In FIG. 1, 1a indicates the dielectric constant measurement interface, 1b indicates the impedance measurement device, 2 indicates the dynamic viscoelasticity measurement device, and 2a indicates the measurement electrodes. That is, in this dielectric relaxation measurement device, the dielectric constant measurement interface 1a connected and arranged on the impedance measurement device 1b is connected to the dynamic viscoelasticity measurement device 2, and the measurement electrodes 2a are attached to the dynamic viscoelasticity measurement device 2. Then, the sample to be measured is sandwiched between the measurement electrodes 2a to perform the measurement.

[0081] The dielectric constant measurement interface 1a used was a 1296 type dielectric constant measurement interface manufactured by Solartron Ltd., UK. The impedance measurement device 1b used was a 1255B type impedance analyzer manufactured by Solartron Ltd., UK. The dynamic viscoelasticity measurement device 2 used was an RSA manufactured by TA Instruments. The measurement was performed according to the time-temperature conversion law (WLF formula) up to the low dielectric constant side (frequency 0.0001 to 0.00001 Hz), and the final dielectric constant was measured.

[0082] The relationship between the specific surface area of ​​the inorganic filler and the dielectric relaxation value is shown in Figure 2. Figure 2 shows the specific surface area (surface area per g, m 2 ) as the X-coordinate and the dielectric relaxation value as the Y-coordinate. As shown in Figure 2, a positive correlation was observed between the specific surface area of ​​the inorganic filler and the dielectric relaxation value measured at a frequency of 0.001 Hz.

[0083] <Second embodiment> The following components were mixed in the amounts (unit: parts by mass) shown in Table 2, and roll kneading was carried out under conditions of a kneading temperature of 100° C. and a kneading time of 10 minutes to prepare an encapsulating resin composition.

[0084] [Table 2]

[0085] Details of each component shown in the table are as follows. Epoxy resin: phenol aralkyl type epoxy resin containing a biphenylene skeleton with an epoxy equivalent of 241 and a softening point of 96°C (Nippon Kayaku Co., Ltd., product name CER-3000L) · Hardener: Xylylene-type phenolic resin with a hydroxyl equivalent of 175 and a softening point of 70°C (Meiwa Kasei Co., Ltd., product name MEHC-7800SS) Curing accelerator: betaine-type adduct of triphenylphosphine and 1,4-benzoquinone ·Silane coupling agent 1…3-mercaptopropyltrimethoxysilane ·Silane coupling agent 2…3-aminopropyltriethoxysilane Silane coupling agent 3: Methyltrimethoxysilane Silane coupling agent 4: N-phenyl-3-aminopropyltrimethoxysilane ·Silane coupling agent 5…3-glycidoxypropyltrimethoxysilane Colorant: Carbon black ·Inorganic filler 1…average particle size 24.3μm, specific surface area 2.86m 2 / g spherical fused silica ·Inorganic filler 2…average particle size 0.13μm, specific surface area 7.00m 2 / g spherical fused silica

[0086] Using the prepared encapsulating resin composition, a test piece was produced in the same manner as in the first embodiment, and the dielectric relaxation value was measured. The results are shown in Table 2.

[0087] As shown in Table 2, -NH was used as a coupling agent. 2 The encapsulating resin compositions of the Examples in which a silane coupling agent having -SH or -SH-containing functional groups was used had smaller dielectric relaxation values ​​at 0.001 Hz than the encapsulating resin compositions of the Comparative Examples in which a silane coupling agent having another functional group was used.

[0088] <Third embodiment> The following components were mixed in the amounts (unit: parts by mass) shown in Table 3, and roll kneading was carried out under conditions of a kneading temperature of 100° C. and a kneading time of 10 minutes to prepare an encapsulating resin composition.

[0089] [Table 3]

[0090] Details of each component shown in the table are as follows. Epoxy resin A: Tetramethylbiphenol type solid epoxy resin (YX-4000H, Mitsubishi Chemical Corporation) Epoxy resin B: α-2,3-epoxypropylphenyl-ω-hydropoly(n=1-7) [2-(2,3-epoxypropoxy)benzylidene-2,3-epoxypropoxyphenylene (EPPN-501HY, Nippon Kayaku Co., Ltd.) Epoxy resin C: Biphenyl novolac epoxy resin (NC-3000, Nippon Kayaku Co., Ltd.) Epoxy resin D...O-cresol novolac glycidyl ether (N500P, DIC Corporation) Epoxy resin E: Naphthalene-modified novolac epoxy resin with a softening point of 58°C (HP-5000, DIC Corporation) Epoxy resin F: DCPD type epoxy resin (HP-7200, DIC Corporation) Epoxy resin G: Epoxy resin with a melting point of 107°C (EXA-5300, DIC Corporation) Epoxy resin H…Dicyclopentadiene-dimethylol diglycyl ether (EP-HA01, ADEKA Corporation) Hardener a: Phenolic resin (MEW-1800, Meiwa Kasei Co., Ltd.) Hardener b: Polycondensation product of phenol and p-xylene glycol dimethyl ether (MEH-7800, Meiwa Kasei Co., Ltd.) Curing accelerator: betaine-type adduct of triphenylphosphine and 1,4-benzoquinone Coupling agent: 3-(phenylamino)propyltrimethoxylane (KBM-573, Shin-Etsu Chemical Co., Ltd.) Carbon: Carbon black (MA-600, Mitsubishi Chemical Corporation) Inorganic filler: amorphous silicon dioxide (containing less than 5% crystalline matter) (FB-9454, Denka Co., Ltd.)

[0091] Using the prepared encapsulating resin composition, a test piece was prepared in the same manner as in the first embodiment, and the dielectric relaxation value was measured. Furthermore, using the dynamic storage modulus of the rubber region obtained by a dynamic viscoelasticity measuring device, the value calculated according to the following formula was taken as the crosslink density. In this example, the RSA3 manufactured by TA Instruments was used as the measuring device. Calculation formula: n=E' / 3RT n: Crosslink density [mol / cm 3 ] E': Dynamic storage modulus [Pa] R: Gas constant 8.31 [J / mol K] T: Absolute temperature [K]

[0092] The relationship between the crosslink density of the encapsulating resin composition and the dielectric relaxation value measured at a frequency of 0.001 Hz is shown in Figure 3. Figure 3 shows the crosslink density (mol / cm 3 ) is shown as the X-coordinate, and the dielectric relaxation value measured at a frequency of 0.001 Hz is shown as the Y-coordinate.

[0093] As shown in FIG. 3, the crosslink density of the encapsulating resin composition is 0.9 mol / cm 3 In the following range, a positive correlation was observed between the crosslink density and the dielectric relaxation value measured at a frequency of 0.001 Hz. In addition, when the crosslink density of the encapsulating resin composition was 1.0 mol / cm 3 In the above range, a negative correlation was observed between the crosslink density and the dielectric relaxation value measured at a frequency of 0.001 Hz. Furthermore, the crosslink density of the encapsulating resin composition is 0.9 mol / cm 3 Less than or equal to 1.0 mol / cm 3 When the dielectric relaxation value was measured at a frequency of 0.001 Hz, the dielectric relaxation value was 20 or less.

[0094] <Reference example> In order to examine the relationship between the dielectric relaxation value measured at a frequency of 0.001 Hz when the encapsulating resin composition was in a cured state and the electrical reliability of a semiconductor device produced using the encapsulating resin composition, the following test was carried out.

[0095] (Preparation of Encapsulating Resin Composition) The components shown below were mixed in the mixing ratios (parts by mass) shown in Table 4, and roll kneading was carried out under conditions of a kneading temperature of 80° C. and a kneading time of 10 minutes to prepare an encapsulating resin composition.

[0096] [Table 4]

[0097] Details of each component shown in the table are as follows. Epoxy resin A: Polycondensation product of α-hydroxyphenyl-ω-hydropoly(n=1-7) (biphenyldimethylene-hydroxyphenylene) and 1-chloro-2,3-epoxypropane (CER-3000L, Nippon Kayaku Co., Ltd.) Epoxy resin B: reaction product of 2,2'-dimethyl-4,4'-dihydroxy-5,5'-di-tert-butyldiphenyl sulfide and chloromethyloxirane (YSLV-120TE, Nippon Steel & Sumikin Chemical Co., Ltd.) Epoxy resin C: Tetramethylbiphenol type solid epoxy resin (YX-4000, Mitsubishi Chemical Corporation) Epoxy resin D: A mixture of α solid epoxy resin and 4,4'-biphenol type epoxy resin (YX-7399, Mitsubishi Chemical Corporation) · Hardener: Polycondensation product of phenol and p-xylene glycol dimethyl ether (MEH-7800, Meiwa Kasei Co., Ltd.) · Curing agent accelerator a'... Tri-para-tolylphosphine and 1,4-benzoquinone adduct · Curing agent accelerator b'… Triphenylphosphine and 1,4-benzoquinone adduct Coupling agent a: 3-(phenylamino)propyltrimethoxysilane (KBM-573, Shin-Etsu Chemical Co., Ltd.) Coupling agent b: Methyltrimethoxysilane (KBM-13, Shin-Etsu Chemical Co., Ltd.) Coupling agent c...3-glycidyloxypropyltrimethoxysilane (KBM-403, Shin-Etsu Chemical Co., Ltd.) Coupling agent d...Diphenyldimethoxysilane (KBM-202SS, Shin-Etsu Chemical Co., Ltd.) Inorganic filler: amorphous silicon dioxide (containing less than 5% crystalline matter) (FB-9454, Denka Co., Ltd.)

[0098] (Measurement of dielectric relaxation value) The prepared encapsulating resin composition was used to measure the dielectric relaxation value in the same manner as in the first embodiment. The measurement was performed at a frequency of 0.001 Hz and a frequency of 1 MHz.

[0099] (High temperature reverse bias test) A diode was die-bonded to a discrete package (TO-247) using solder, and an Al wire was further bonded, followed by sealing with a sealing resin composition to prepare a package for evaluation. This package was placed in a high-temperature dryer, and a voltage was applied taking into account the package heat capacity obtained by a transient thermal analysis device (T3Ster). In this reference example, the temperature in the high-temperature dryer was set to 170°C, and the voltage was set to 1280V. The package was left in the high-temperature dryer for 1000 hours with the voltage applied, and then removed, and the leakage current was measured using a Curve Tracer (CS-3200) from Iwasaki Electric Co., Ltd.

[0100] The measured dielectric relaxation values ​​and the results of the high-temperature reverse bias test are shown in Table 4, and in FIGS. FIG. 4 is a scatter plot in which the measured values ​​of the dielectric relaxation values ​​(at a frequency of 0.001 Hz) of the samples prepared from the encapsulating resin compositions of Reference Examples 1 to 5 are plotted on the X-coordinate, and the leakage current (μA) in a high-temperature reverse bias test is plotted on the Y-coordinate. FIG. 5 is a scatter plot in which the measured dielectric relaxation values ​​(at a frequency of 1 MHz) of the samples prepared from the encapsulating resin compositions of Reference Examples 2 to 5 are plotted on the X-coordinate, and the leakage current (μA) in a high-temperature reverse bias test is plotted on the Y-coordinate.

[0101] As shown in FIG. 4, a positive correlation was observed between the dielectric relaxation value measured at a frequency of 0.001 Hz and the leakage current (μA) in the high-temperature reverse bias test. Furthermore, when the dielectric relaxation value measured at a frequency of 0.001 Hz was 20 or less, the results of the high temperature reverse bias test were good.

[0102] As shown in FIG. 5, no correlation was observed between the dielectric relaxation value measured at a frequency of 1 MHz and the leakage current (μA) in the high-temperature reverse bias test.

[0103] From the above, it was found that the encapsulating resin composition of the present disclosure makes it possible to manufacture a semiconductor device having excellent electrical reliability. [Explanation of symbols]

[0104] The disclosures of Japanese Patent Applications Nos. 2017-156441, 2017-156442, and 2017-156443 are incorporated herein by reference in their entireties. All publications, patent applications, and technical standards mentioned in this specification are incorporated by reference into this specification to the same extent as if each individual publication, patent application, and technical standard was specifically and individually indicated to be incorporated by reference.

Claims

1. It contains an epoxy resin (excluding triphenylmethane type epoxy resin), a curing agent, an inorganic filler, and a silane coupling agent having -SH, and has a crosslink density of 1.57 mol / cm in the cured state. ３ That's all. the epoxy resin comprises a biphenyl novolac epoxy resin or an o-cresol novolac glycidyl ether, the curing agent comprises a phenolic resin, and the inorganic filler comprises silicon dioxide; The crosslink density of the encapsulating resin composition is a value calculated according to the following formula using the dynamic storage modulus of the rubber region determined by a dynamic viscoelasticity measuring device. Calculation formula: n=E' / 3RT n: bridging density [mol / cm ３ ] E': Dynamic storage modulus [Pa] R: gas constant 8.31 [J / mol K] T: Absolute temperature [K]

2. 2. The encapsulating resin composition according to claim 1, which has a dielectric relaxation value of 17.7 or less when measured at a frequency of 0.001 Hz in a cured state.

3. The specific surface area of ​​the inorganic filler is 3.28 m ２ The encapsulating resin composition according to claim 1 or 2, wherein the viscosity is 100 / g or less.

4. The encapsulating resin composition according to any one of claims 1 to 3, which is used for encapsulating a power semiconductor element.

5. The encapsulating resin composition according to any one of claims 1 to 4, wherein the content of the inorganic filler is 70 volume % or more of the encapsulating resin composition.

6. The crosslink density in the cured state is 1.57 mol / cm ３ A method for producing the encapsulating resin composition according to any one of claims 1 to 5, comprising the step of controlling the temperature so as to be as described above.

7. A semiconductor device comprising: a support; a semiconductor element disposed on the support; and a cured product of the encapsulating resin composition according to any one of claims 1 to 5, encapsulating the semiconductor element.

8. A method for manufacturing a semiconductor device, comprising: a step of disposing a semiconductor element on a support; and a step of encapsulating the semiconductor element with the encapsulating resin composition according to any one of claims 1 to 5.

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