Compression molding sealing material and electronic component device

Abstract

To provide a compression molding sealing material in which wire sweep due to compression molding is suppressed.SOLUTION: A compression molding sealing material includes an epoxy resin, a curing agent, and an inorganic filler, and in an image obtained by observing, with an ultrasonic flaw detector, a compression molded body obtained by compression molding the compression molding sealing material on a substrate via a silicon chip, the area of a region corresponding to the compression molded body on the chip other than black dots is 86% or more of the area of the entire region corresponding to the compression molded body on the chip.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present disclosure relates to a compression molding encapsulant and an electronic component device. [Background technology]

[0002] In the field of element encapsulation of electronic component devices such as transistors and ICs (Integrated Circuits), resin encapsulation has been the mainstream from the viewpoints of productivity, cost, etc. In recent years, electronic components have been increasingly mounted on printed wiring boards at high density. Accordingly, semiconductor devices are now mainly mounted in surface-mounted packages rather than conventional pin-insertion packages. Surface-mounted ICs, LSIs (Large-Scale Integration), etc. are packaged in thin and small packages to increase the mounting density and reduce the mounting height, so that the volume occupied by the element in the package is large and the thickness of the package is very thin.

[0003] Furthermore, the chip area and pin count are increasing due to the multi-function and large capacity of elements, and the pad pitch and pad size are decreasing due to the increase in the number of pads (electrodes). In order to further reduce size and weight, the package form is also shifting from QFP (Quad Flat Package) and SOP (Small Outline Package) to CSP (Chip Size Package) and BGA (Ball Grid Array), which can easily accommodate more pins and enable higher density mounting.

[0004] Methods for resin encapsulation of electronic component devices include the commonly used transfer molding method, as well as compression molding (see, for example, Patent Document 1). Compression molding is a method for resin encapsulation in which an encapsulant, which is a powdered resin composition, is supplied to face an object to be encapsulated (such as a substrate on which electronic elements such as semiconductor chips are provided) held in a mold, and the object to be encapsulated and the encapsulant are compressed to perform resin encapsulation. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2008-279599 A Summary of the Invention [Problem to be solved by the invention]

[0006] As packages become more multifunctional, the built-in wires are becoming thinner, making it a challenge to prevent wire sweep not only in transfer molding but also in compression molding.

[0007] In view of the above circumstances, an objective of a first embodiment of the present disclosure is to provide a compression molding encapsulant in which wire sweep due to compression molding is suppressed, and an electronic component device including an element encapsulated by the compression molding encapsulant. [Means for solving the problem]

[0008] The embodiments of the present disclosure include the following aspects. <1> A compression molding sealing material containing an epoxy resin, a curing agent, and an inorganic filler, A sealing material for compression molding, in which in an image obtained by observing a compression molded body obtained by compression molding the sealing material onto a substrate via a silicon chip using an ultrasonic flaw detection device, the area of ​​the region corresponding to the compression molded body on the chip other than black dots is 86% or more of the total area of ​​the region corresponding to the compression molded body on the chip. <2> The inorganic filler is treated with a coupling agent. <1> The compression molding sealing material according to claim 1. <3> The coupling agent is a silane coupling agent. <2> The compression molding sealing material according to claim 1. <4> The coupling agent has at least one functional group selected from a (meth)acryloyl group, an epoxy group, and a phenyl group. <2> or <3> The compression molding sealing material according to claim 1. <5> The coupling agent has a secondary amino group. <2> ~ <4> 13. The encapsulating material for compression molding according to claim 12 . <6> The inorganic filler has a maximum value in the range of 0.1 μm to 2 μm in the volume-based particle size distribution. <1> ~ <5> 13. The encapsulating material for compression molding according to claim 12 . <7> An element and a device for sealing the element <1> ~ <6> and a cured product of the compression molding sealing material according to any one of the above items. Effect of the Invention

[0009] According to a first embodiment of the present disclosure, there are provided a compression-molding encapsulant in which wire sweep due to compression molding is suppressed, and an electronic component device including an element encapsulated with the compression-molding encapsulant. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] 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. 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 corresponding substances. When multiple types of 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 contain multiple types of particles. 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. In the present disclosure, a "(meth)acryloyl group" means at least one of an acryloyl group and a methacryloyl group, and a "(meth)acryloyloxy group" means at least one of an acryloyloxy group and a methacryloyloxy group.

[0011] <Sealing material for compression molding> The sealing material of the present disclosure is a compression molding sealing material containing an epoxy resin, a curing agent, and an inorganic filler, and in an image obtained by observing a compression molded body obtained by compression molding the compression molding sealing material onto a substrate via a silicon chip using an ultrasonic flaw detection device, the area other than black dots in the region corresponding to the compression molded body on the chip is 86% or more of the total area of ​​the region corresponding to the compression molded body on the chip. Hereinafter, the sealing material for compression molding is also simply referred to as "sealing material". In addition, among images obtained by observing a compression molded body obtained by compression molding the sealing material for compression molding on a substrate via a silicon chip using an ultrasonic flaw detector, the region corresponding to the image of the compression molded body on the silicon chip is also referred to as the "SAT image". In addition, the ratio of the area other than black spots to the entire area of ​​the SAT image is also referred to as the "non-black spot ratio".

[0012] The sealing material of the present disclosure has a non-black spot ratio in the above range when formed into a compression molded article, and therefore wire sweep due to compression molding is suppressed. The reason for this is unclear, but is presumed to be as follows. In the SAT image, for example, a region where resin is locally distributed unevenly (hereinafter also referred to as a "resin-rich region") appears as a black dot. It is considered that this resin-rich region is caused by, for example, bubbles being broken by gas dissolved in the encapsulant due to the reduced pressure during compression molding, and the amount of inorganic filler at the broken bubble location being locally reduced. For example, in an encapsulant with low fluidity, even if a region where the amount of inorganic filler is locally reduced occurs, the inorganic filler is unlikely to flow into that region due to flow. Therefore, it is considered that the region where the amount of inorganic filler is locally reduced hardens as it is, becoming a resin-rich region. And, it is considered that an encapsulant with many resin-rich regions like this is prone to wire positional deviation (i.e., wire flow) when pressure is applied to the wire during compression molding due to its low fluidity. In contrast, the sealing material of the present disclosure, which can obtain a compression molded body with a large non-black spot ratio, is thought to flow easily and cause the inorganic filler to flow in, suppressing the generation of resin-rich regions, even if localized areas with little inorganic filler are generated due to bubble breakage during decompression. And it is presumed that the sealing material in which the generation of resin-rich regions is suppressed in this way has high fluidity, and thus suppresses wire sweep due to compression molding.

[0013] In addition, since an encapsulating material in which a large number of resin-rich regions are generated has low fluidity, air bubbles generated during compression molding are likely to remain, and a compression molded body having voids may be obtained. These voids may appear as black spots in the SAT image. However, the encapsulant of the present disclosure, which can produce a compression molded body with a large non-black spot ratio, is thought to have high fluidity and therefore is unlikely to produce either resin-rich regions or voids. In this way, it is presumed that the encapsulant with high fluidity in which both the generation of resin-rich regions and the generation of voids are suppressed is unlikely to cause wire sweep during compression molding.

[0014] Here, the SAT image of the compression molded encapsulant is obtained as follows. Specifically, first, a compression molding substrate is prepared with chips arranged on one side of the substrate. An example of the substrate is one with dimensions of 240 mm wide x 74 mm long x 0.45 mm thick. An example of the silicon chip is one with dimensions of 10 mm wide x 8 mm long x 0.4 mm thick, made of silicon. The compression molding substrate is obtained by providing a total of 12 chips (3 wide x 4 long) at the center of one side of the substrate, spaced apart from each other by a distance of 8 mm. By using a compression molding base material with a silicon chip disposed on one side of the substrate and observing the compression molded body on the silicon chip with an ultrasonic flaw detector, not only voids but also resin-rich regions can be confirmed as black dots, as described above. The resin-rich regions also appear as black dots when a metal chip with a mirror surface is used instead of the silicon chip. On the other hand, when a compression molded body that is compression molded directly onto a substrate (such as a general resin substrate or a metal substrate) on which no chip is disposed is observed with an ultrasonic flaw detector, voids can be confirmed as black dots, but resin-rich regions are unlikely to appear as black dots.

[0015] Next, the sealing material to be measured is compression molded by a compression molding device onto the surface of the compression molding base material on which the chip is arranged. The molding conditions for compression molding were as follows: mold temperature: 175°C, molding pressure: approximately 10 MPa, curing time: 120 seconds, and vacuum retention time: 3 seconds. Furthermore, the thickness of the compression molded body obtained by the above compression molding (i.e., the compression molded body for measuring the non-black spot ratio) is, for example, 0.8 mm in areas where the chip is not placed (i.e., the areas where the compression molded body is directly provided on the substrate) and 0.4 mm on the chip.

[0016] Next, the obtained compression molded body is observed by an SAT (that is, an ultrasonic flaw detector, for example, Hitachi Power Solutions Co., Ltd., model number: FS200 III A) to obtain an image. The SAT observation conditions are a probe frequency of 50 MHz. Of the obtained images, the region corresponding to the image of the compression molded body molded on the chip of the compression molding substrate is designated as the "SAT image." In an SAT image, when the contrast range of the image is (0 to 255), the area from 0 to 99 is defined as "black spots" and the area from 100 to 255 is defined as "non-black spots." The non-sunspot ratio in the SAT image is calculated by analyzing a total of 12 chips, each measuring 10 mm x 8 mm, according to the above definition, and then calculating the total. Each component contained in the encapsulant according to the present disclosure will be described in detail below.

[0017] (Epoxy resin) The type of epoxy resin is not particularly limited as long as it has an epoxy group in the molecule. Specific examples of the epoxy resin include novolac-type epoxy resins (phenol novolac-type epoxy resins, orthocresol novolac-type epoxy resins, etc.) obtained by epoxidizing a novolac resin 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 acidic catalyst; triphenylmethane-type epoxy resins obtained by epoxidizing a triphenylmethane-type phenolic resin obtained by condensing or co-condensing the above-mentioned phenolic compound with an aromatic aldehyde compound such as benzaldehyde, salicylaldehyde, etc., under an acidic catalyst; and novolac resins obtained by co-condensing the above-mentioned phenolic compound and naphthol compound with an aldehyde compound under an acidic catalyst. copolymer epoxy resins in which epoxidized oils are used; 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 hydrogens bonded to nitrogen atoms of aniline, diaminodiphenylmethane, isocyanuric acid, etc. are replaced with glycidyl groups; dicyclopentadiene-type epoxy resins in which co-condensation resins of dicyclopentadiene and phenolic compounds are epoxidized;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.;

[0018] Among the above-mentioned epoxy resins, from the viewpoint of the balance between reflow resistance and fluidity, an epoxy resin selected from the group consisting of biphenyl-type epoxy resins, stilbene-type epoxy resins, diphenylmethane-type epoxy resins, sulfur-containing epoxy resins, novolac-type epoxy resins, dicyclopentadiene-type epoxy resins, triphenylmethane-type epoxy resins, copolymer-type epoxy resins, and aralkyl-type epoxy resins is preferred.

[0019] 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.

[0020] The epoxy equivalent of the epoxy resin is a value measured by a method conforming to JIS K 7236:2009.

[0021] 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 viewpoint of moldability and reflow resistance, and more preferably 50°C to 130°C from the viewpoint of handleability during preparation of the sealing material.

[0022] 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).

[0023] From the viewpoints of strength, fluidity, heat resistance, moldability, etc., the content of the epoxy resin in the sealing material is preferably 0.5% by mass to 50% by mass, more preferably 2% by mass to 30% by mass, and even more preferably 2% by mass to 20% by mass.

[0024] (hardening agent) The type of curing agent is not particularly limited, and can be selected depending on the type of resin, the desired properties of the encapsulating material, and the like. Examples of the curing agent include a phenol curing agent, an amine curing agent, an acid anhydride curing agent, a polymercaptan curing agent, a polyaminoamide curing agent, an isocyanate curing agent, a blocked isocyanate curing agent, etc. From the viewpoint of improving heat resistance, the curing agent is preferably one having a phenolic hydroxyl group in the molecule (phenol curing agent).

[0025] 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, etc.; paraxylylene and / or metaxylylene modified phenolic resins; melamine modified phenolic resins; terpene modified phenolic resins; dicyclopentadiene-type phenolic resins and dicyclopentadiene-type naphthol resins synthesized by copolymerization of the above phenolic compounds with 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 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.

[0026] 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.

[0027] 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.

[0028] 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 encapsulant.

[0029] 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.

[0030] The equivalent ratio of the epoxy resin to the curing agent, that is, the ratio of the number of functional groups in the curing agent to the number of epoxy groups in the epoxy resin (number of functional groups in the curing agent / number of epoxy groups in the epoxy resin) is not particularly limited. In terms of keeping the amount of unreacted components low, it is preferably set in the range of 0.5 to 2.0, and more preferably set in the range of 0.6 to 1.3. In terms of moldability and reflow resistance, it is even more preferably set in the range of 0.8 to 1.2.

[0031] (Inorganic filler) The material of the inorganic filler is not particularly limited. Specific examples of the inorganic filler include inorganic materials such as spherical silica, crystalline silica, glass, alumina, calcium carbonate, zirconium silicate, calcium silicate, silicon nitride, aluminum nitride, boron nitride, magnesium oxide, silicon carbide, beryllia, zirconia, zircon, fosterite, steatite, spinel, mullite, titania, talc, clay, and mica. Inorganic fillers having a flame retardant effect may be used. Examples of inorganic fillers having a flame retardant effect include aluminum hydroxide, magnesium hydroxide, composite metal hydroxides such as composite hydroxides of magnesium and zinc, and zinc borate.

[0032] The shape of the inorganic filler is not particularly limited, but from the viewpoints of filling properties and die wear, a spherical shape is preferred.

[0033] The inorganic filler may be used alone or in combination of two or more. The term "use of two or more inorganic fillers" refers to, for example, use of two or more inorganic fillers having the same components but different average particle sizes, use of two or more inorganic fillers having the same average particle size but different components, and use of two or more inorganic fillers having different average particle sizes and types.

[0034] Of the above specific examples, preferred examples of the inorganic filler include spherical silica, crystalline silica, and alumina, and more preferred examples include spherical silica.

[0035] The content of the inorganic filler in the entire sealing material is not particularly limited. From the viewpoint of further improving the properties such as the thermal expansion coefficient, thermal conductivity, and elastic modulus in the compression molded body of the sealing material, the content of the inorganic filler is preferably 30 volume% or more of the entire sealing material, more preferably 35 volume% or more, even more preferably 40 volume% or more, particularly preferably 45 volume% or more, and extremely preferably 50 volume% or more. From the viewpoint of improving the fluidity, reducing the viscosity, etc., the content of the inorganic filler is preferably 99 volume% or less of the entire sealing material, preferably 98 volume% or less, and more preferably 97 volume% or less. The content of the inorganic filler in the entire sealing material of the present disclosure used for compression molding may be 60 volume% to 99 volume%, 70 volume% to 99 volume%, 73 volume% to 99 volume%, or 75 volume% to 99 volume%.

[0036] The content of the inorganic filler in the encapsulant is measured as follows. First, the total mass of the cured product (compression molded product) of the encapsulant is measured, and the cured product is baked at 400°C for 2 hours and then at 700°C for 3 hours to evaporate the resin component, and the mass of the remaining inorganic filler is measured. The volumes are calculated from the obtained masses and their respective specific gravities, and the ratio of the volume of the inorganic filler to the total volume of the encapsulant is obtained, which is the content of the inorganic filler.

[0037] When the inorganic filler is particulate, its average particle size is not particularly limited. For example, the volume average particle size of the whole inorganic filler is preferably 80 μm or less, may be 50 μm or less, may be 40 μm or less, may be 30 μm or less, may be 25 μm or less, may be 20 μm or less, may be 15 μm or less. In addition, the volume average particle size of the whole inorganic filler is preferably 0.1 μm or more, more preferably 0.2 μm or more, and even more preferably 0.3 μm or more. When the volume average particle size of the inorganic filler is 0.1 μm or more, the increase in viscosity of the sealing material tends to be more suppressed. When the volume average particle size is 80 μm or less, the filling property into a narrow gap tends to be more improved.

[0038] The average particle size of the inorganic filler can be measured by the following method. The inorganic filler to be measured is added to a solvent (pure water), and after ultrasonic treatment for 300 seconds, the particle size distribution is measured. A laser diffraction particle size distribution measuring device (HORIBA, Ltd., product name: LA-920) is used to measure the volumetric particle size distribution. The volume average particle size is then calculated as the particle size (D50%) when the cumulative amount from the small diameter side in the volumetric particle size distribution is 50%.

[0039] From the viewpoint of fluidity and moldability, the specific surface area of ​​the inorganic filler is set to 0.7 m 2 / g~4.0m 2 / g, and preferably 0.9m 2 / g~3.0m 2 / g, more preferably 1.0m 2 / g~2.5m 2 It is more preferable that the molecular weight is / g. The fluidity of the sealing material tends to increase as the specific surface area of ​​the inorganic filler decreases.

[0040] The specific surface area (BET specific surface area) of the inorganic filler can be measured from the nitrogen adsorption capacity in accordance with JIS Z 8830:2013. As an evaluation device, AUTOSORB-1 (product name) from QUANTACHROME can be used. When measuring the BET specific surface area, it is preferable to first perform a pretreatment to remove moisture by heating, since it is considered that moisture adsorbed on the sample surface and in the structure affects the gas adsorption capacity. In pretreatment, a measurement cell containing 0.05 g of a measurement sample is depressurized to 10 Pa or less using a vacuum pump, heated to 110°C, and held for 3 hours or more, after which it is naturally cooled to room temperature (25°C) while maintaining the reduced pressure. After this pretreatment, measurements are performed with an evaluation temperature of 77 K and an evaluation pressure range of less than 1 in terms of relative pressure (equilibrium pressure relative to saturated vapor pressure).

[0041] The inorganic filler may have a controlled maximum particle size (cut point) from the viewpoint of improving the filling property in narrow gaps. The maximum particle size of the inorganic filler may be appropriately adjusted, and from the viewpoint of filling property, it is preferably 105 μm or less, more preferably 75 μm or less, may be 60 μm or less, or may be 40 μm or less. The maximum particle size can be measured by a laser diffraction particle size distribution meter (HORIBA, Ltd., product name: LA-920).

[0042] In terms of achieving both improved thermal conductivity and improved fluidity, the inorganic filler preferably has a maximum value in the range of 0.1 μm to 2 μm in the volumetric particle size distribution. The inorganic filler may have a maximum value in the range of 0.1 μm to 2 μm and a maximum value in the range of more than 2 μm in the volumetric particle size distribution. An example of an inorganic filler having a maximum value at 0.1 μm to 2 μm in the volume-based particle size distribution is a mixture of a first inorganic filler having a volume average particle diameter of 0.1 μm to 2 μm and a second inorganic filler having a volume average particle diameter of more than 2 μm.

[0043] When the inorganic filler is a mixture of a first inorganic filler and a second inorganic filler, the proportion of the first inorganic filler in the entire composition is, for example, in the range of 2 mass% to 30 mass%, and from the viewpoint of fluidity and fillability into narrow passages, is preferably in the range of 2.5 mass% to 25 mass%, and more preferably in the range of 2.6 mass% to 20 mass%.

[0044] The volume average particle diameter of the first inorganic filler is, for example, 0.1 μm to 2.0 μm, preferably 0.2 μm to 1.5 μm, and more preferably 0.3 μm to 1.0 μm. The volume average particle diameter of the second inorganic filler is, for example, in the range of more than 2.0 μm to 75 μm or less, preferably 5.0 μm to 55 μm, and more preferably 8.0 μm to 20 μm. The BET specific surface area of ​​the first inorganic filler is, for example, 1.0 m 2 / g~20m 2 / g, and 2m 2 / g~17m 2 / g is preferred, 3m 2 / g~15m 2 / g is more preferable, and 3.5m 2 / g~10m 2 The BET specific surface area of ​​the second inorganic filler is preferably 0.5 m / g. 2 / g~10m 2 / g, and 0.7m 2 / g~7m 2 / g is preferred, and 0.9m 2 / g~5m 2 / g is more preferable, and 1.0m 2 / g~4.5m 2 / g is more preferred. Examples of the first inorganic filler include spherical silica, alumina, calcium silicate, calcium carbonate, magnesium oxide, potassium titanate, silicon nitride, aluminum nitride, boron nitride, beryllia, zirconia, zircon, and titania powders, as well as beads and glass fibers obtained by sphering these, among which spherical silica is preferred from the viewpoint of improving fluidity. Examples of the second inorganic filler include powders such as spherical silica, alumina, calcium silicate, calcium carbonate, magnesium oxide, potassium titanate, silicon nitride, aluminum nitride, boron nitride, beryllia, zirconia, zircon, and titania powders, as well as beads and glass fibers obtained by sphering these, among which spherical silica and alumina are preferred, and spherical silica is more preferred from the viewpoint of filling properties and reduction of linear expansion coefficient. The combination of the first inorganic filler and the second inorganic filler is preferably a combination of spherical silica and alumina, a combination of spherical silica and spherical silica, or a combination of alumina and alumina. Among them, from the viewpoint of improving both fluidity and thermal conductivity, a combination of spherical silica and alumina is preferable as the combination of the first inorganic filler and the second inorganic filler. Also, from the viewpoint of improving fluidity, a combination of spherical silica and spherical silica is preferable as the combination of the first inorganic filler and the second inorganic filler.

[0045] The inorganic filler may be treated with a coupling agent. In particular, when the inorganic filler is a mixture of the first inorganic filler and the second inorganic filler, it is preferable that at least the first inorganic filler is treated with a coupling agent. By using a mixture of the first inorganic filler treated with a coupling agent and the second inorganic filler as the inorganic filler, it becomes easier to control the non-black spot ratio when the compression molded body is formed within the above range. The second inorganic filler may be treated with a coupling agent or may not be treated.

[0046] When the first inorganic filler is treated with a coupling agent, the mass loss rate of the first inorganic filler treated with the coupling agent at 800°C is, for example, in the range of 0.27% to 1.0%, and from the viewpoint of controlling the non-black spot ratio within the above range, it is preferably in the range of 0.3% to 0.9%, and more preferably in the range of 0.35% to 0.8%. The mass reduction rate at 800°C is calculated by first measuring the mass W0 of the inorganic filler before heating without preheating, etc., then heating at a rate of 10°C / min, measuring the mass W1 of the inorganic filler when it reaches 800°C, and calculating the mass reduction rate (%) using the following formula. Formula: Mass reduction rate (%)=((W0-W1) / W0)×100

[0047] The type of coupling agent used to treat inorganic filler is not particularly limited, and known coupling agents can be used.Coupling agents include silane coupling agents, titanium coupling agents, zirconium coupling agents, aluminum coupling agents, etc., among which silane coupling agents or titanium coupling agents are preferred, and silane coupling agents are more preferred.Coupling agents used to treat inorganic filler may be used alone or in combination of two or more.

[0048] The coupling agent used to treat the inorganic filler preferably has at least one functional group (hereinafter also referred to as the specific functional group) selected from a (meth)acryloyl group, an epoxy group, and a phenyl group, and more preferably has a phenyl group. The coupling agent may be a coupling agent having a functional group containing a specific functional group. Examples of the functional group containing a specific functional group include a (meth)acryloyloxy group, a glycidyloxy group, and a phenylamino group. The coupling agent is preferably a silane coupling agent having a functional group containing a specific functional group, and more preferably a silane coupling agent in which the functional group containing the specific functional group is bonded to a silicon atom directly or via a chain hydrocarbon group having 1 to 5 carbon atoms. The coupling agent may be a coupling agent having at least one selected from a primary amino group, a secondary amino group, and a tertiary amino group, and among them, may be a coupling agent having a secondary amino group.

[0049] The silane coupling agent may be a compound in which at least one of an alkoxy group and a halogen atom is directly bonded to a silicon atom. Specific examples of silane coupling agents include vinyltrichlorosilane, vinyltriethoxysilane, vinyltris(β-methoxyethoxy)silane, γ-methacryloxypropyltrimethoxysilane, 8-methacryloxyoctyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-[bis(β-hydroxyethyl)]aminopropyltriethoxysilane, and N-β-(aminoethyl) -γ-aminopropyltrimethoxysilane, γ-(β-aminoethyl)aminopropyldimethoxymethylsilane, N-(trimethoxysilylpropyl)ethylenediamine, N-(dimethoxymethylsilylisopropyl)ethylenediamine, methyltrimethoxysilane, methyltriethoxysilane, N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, hexamethyldisilane, γ-anilinopropyltrimethoxysilane, vinyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, and the like.

[0050] Examples of titanium coupling agents include isopropyl triisostearoyl titanate, isopropyl tris(dioctyl pyrophosphate) titanate, isopropyl tri(N-aminoethyl-aminoethyl) titanate, tetraoctyl bis(ditridecyl phosphite) titanate, tetra(2,2-diallyloxymethyl-1-butyl)bis(ditridecyl phosphite) titanate, bis(dioctyl pyrophosphate)oxyacetate titanate, bis(dioctyl pyrophosphate)ethylene titanate, isopropyl trioctanoyl titanate, isopropyl dimethacryl isostearoyl titanate, isopropyl tridodecyl benzenesulfonyl titanate, isopropyl isostearoyl diacryl titanate, isopropyl tri(dioctyl phosphate) titanate, isopropyl tricumyl phenyl titanate, and tetraisopropyl bis(dioctyl phosphite) titanate.

[0051] The amount of coupling agent used in treating the inorganic filler is not particularly limited, and is set in consideration of the specific surface area of ​​the inorganic filler, the minimum coverage area of ​​the coupling agent, and the like. The amount of coupling agent used to treat the inorganic filler may be in the range of 0.1 to 2.0 parts by mass, preferably 0.2 to 1.5 parts by mass, and more preferably 0.3 to 1.0 parts by mass, per 100 parts by mass of the inorganic filler to be treated.

[0052] The method for obtaining an inorganic filler treated with a coupling agent is not particularly limited, and examples thereof include a method in which the inorganic filler to be treated is added to a liquid containing a coupling agent and a solvent, and the solvent is removed by drying.

[0053] (Additives) The encapsulant of the present disclosure may contain other components as additives as necessary. Examples of additives include coupling agents, curing accelerators, ion exchangers, release agents, flame retardants, colorants, stress relaxation agents, etc. In addition to these additives, the encapsulant may contain various additives known in the art as necessary.

[0054] -Coupling agent- The encapsulant of the present disclosure may contain a coupling agent as an additive. The coupling agent used as an additive may be the same as the coupling agent used to treat the inorganic filler described above. The coupling agent used as an additive may be used alone or in combination of two or more kinds.

[0055] An example of a sealant using a coupling agent as an additive is a sealant containing a first coupling agent attached to the surface of an inorganic filler and a second coupling agent used as an additive. When the sealant contains both a first coupling agent and a second coupling agent, the second coupling agent may be the same as the first coupling agent or may be different from the first coupling agent. When the encapsulating material contains a first coupling agent and a second coupling agent, the mass ratio of the first coupling agent to the second coupling agent (first coupling agent / second coupling agent) can be in the range of more than 0 and not more than 0.2, preferably in the range of more than 0 and not more than 0.15, and more preferably in the range of more than 0 and not more than 0.1.

[0056] When the encapsulant contains a coupling agent, the content of the coupling agent in the entire encapsulant is preferably 3 mass% or less, more preferably 2 mass% or less, even more preferably 1 mass% or less, and particularly preferably 0.5 mass% or less. From the viewpoint of exerting its effect, the content is preferably 0.1 mass% or more, more preferably 0.15 mass% or more, and even more preferably 0.18 mass% or more. The content of the coupling agent may be 0.01 parts by mass or more, or 0.02 parts by mass or more, relative to 100 parts by mass of the inorganic filler. The content of the coupling agent is preferably 5 parts by mass or less, and more preferably 2.5 parts by mass or less, relative to 100 parts by mass of the inorganic filler. From the viewpoint of achieving both flowability and moldability of the package, the content of the coupling agent is preferably 0.05 parts by mass to 2.0 parts by mass, more preferably 0.1 parts by mass to 1.5 parts by mass, even more preferably 0.2 parts by mass to 1.0 parts by mass, and particularly preferably 0.2 parts by mass to 0.5 parts by mass, relative to 100 parts by mass of the inorganic filler. The coupling agent content and amount indicate the total content of the coupling agents contained in the encapsulant, i.e., when the encapsulant contains a first coupling agent and a second coupling agent, the coupling agent content and amount indicate the total content of the first coupling agent and the second coupling agent, respectively.

[0057] -Curing accelerator- The encapsulant of the present disclosure may contain a curing accelerator as an additive. 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 encapsulant, 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, 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, diazabicycloalkenes such as 1,5-diazabicyclo[4.3.0]nonene-5 (DBN) and 1,8-diazabicyclo[5.4.0]undecene-7 (DBU), and the like. compounds having intramolecular polarization obtained by adding a compound having a π bond, such as 2-phenylphenylmethane; cyclic amidinium compounds, such as the tetraphenylborate salt of DBU, the tetraphenylborate salt of DBN, the tetraphenylborate salt of 2-ethyl-4-methylimidazole, and the tetraphenylborate salt of N-methylmorpholine; 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;organic phosphines such as primary phosphines, e.g., ethylphosphine, phenylphosphine, etc.; secondary phosphines, e.g., dimethylphosphine, diphenylphosphine, etc.; and tertiary phosphines, e.g., triphenylphosphine, diphenyl(p-tolyl)phosphine, tris(alkylphenyl)phosphine, tris(alkoxyphenyl)phosphine, tris(alkyl alkoxyphenyl)phosphine, tris(dialkylphenyl)phosphine, tris(trialkylphenyl)phosphine, tris(tetraalkylphenyl)phosphine, tris(dialkoxyphenyl)phosphine, tris(trialkoxyphenyl)phosphine, tris(tetraalkoxyphenyl)phosphine, trialkylphosphine, dialkylarylphosphine, alkyldiarylphosphine, trinaphthylphosphine, tris(benzyl)phosphine, etc.; phosphine compounds, e.g., complexes of the organic phosphines with organic borons; complexes of the organic phosphines or the phosphine compounds with maleic anhydride, 1,4-benzoquinone, 2,5-toluquinone, 1,4-naphthoquinone, 2,3-dimethylbenzoquinone, quinone compounds such as 1,4-benzoquinone, 2,6-dimethylbenzoquinone, 2,3-dimethoxy-5-methyl-1,4-benzoquinone, 2,3-dimethoxy-1,4-benzoquinone, phenyl-1,4-benzoquinone, anthraquinone, and compounds having intramolecular polarization, which are obtained by adding compounds having a π bond such as diazophenylmethane; a compound having intramolecular polarization, which is obtained by reacting a halogenated phenol compound such as phenol, 3-iodophenol, 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-t-butylphenol, 4-chloro-1-naphthol, 1-bromo-2-naphthol, 6-bromo-2-naphthol, or 4-bromo-4'-hydroxybiphenyl, followed by a dehydrohalogenation process;Examples of the curing accelerator include tetra-substituted phosphonium compounds such as tetraphenylphosphonium, tetraphenylborate salts of tetra-substituted phosphonium such as tetraphenylphosphonium tetra-p-tolylborate, and salts of tetra-substituted phosphonium with phenolic compounds; phosphobetaine compounds; and adducts of phosphonium compounds with silane compounds. The curing accelerator may be used alone or in combination of two or more. Among these, particularly suitable curing accelerators include triphenylphosphine, an adduct of triphenylphosphine and a quinone compound, an adduct of tributylphosphine and a quinone compound, and an adduct of tri-p-tolylphosphine and a quinone compound.

[0058] When the encapsulant 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 (i.e., the total of the epoxy resin and the curing agent). 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 curing tends to be good 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.

[0059] -Ion exchanger- The encapsulant of the present disclosure may contain an ion exchanger as an additive. The encapsulant preferably contains 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 encapsulated. The ion exchanger is not particularly limited, and a conventionally known ion exchanger can be used. Specific examples 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 preferred.

[0060] Mg (1-X) Al X(OH)2(CO3) X / 2 ·mH2O ……(A) (0 < X ≤ 0.5, m is a positive number)

[0061] When the sealing material 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 10 parts by mass, based on 100 parts by mass of the resin component.

[0062] - Release agent - From the viewpoint of obtaining good mold release property with the mold during molding, the sealing material of the present disclosure may contain a release agent as an additive. The release agent is not particularly limited, and conventionally known ones can be used. Specifically, higher fatty acids such as carnauba wax, montanic acid, and stearic acid, metal salts of higher fatty acids, ester waxes such as montanic acid esters, polyolefin waxes such as oxidized polyethylene and non-oxidized polyethylene, etc. can be mentioned. The release agent may be used alone or in combination of two or more kinds.

[0063] When the sealing material contains a release agent, its amount is preferably 0.01 part by mass to 10 parts by mass, more preferably 0.1 part by mass 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 part by mass or more based on 100 parts by mass of the resin component, mold release property tends to be sufficiently obtained. When it is 10 parts by mass or less, better adhesion and curability tend to be obtained. Note that the content of the release agent with respect to 100 parts by mass of the resin component may be less than 0.1 part by mass, or may be less than 0.01 part by mass.

[0064] - Flame retardant - The sealing material of the present disclosure may contain a flame retardant as an additive. The flame retardant is not particularly limited, and conventionally known ones can be used. Specifically, organic or inorganic compounds containing a halogen atom, an antimony atom, a nitrogen atom or a phosphorus atom, metal hydroxides, etc. can be mentioned. The flame retardant may be used alone or in combination of two or more kinds.

[0065] When the encapsulant contains a flame retardant, the amount 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 20 parts by mass, per 100 parts by mass of the resin component.

[0066] -Coloring agent- The encapsulant of the present disclosure may further contain a colorant as an additive. 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.

[0067] -Stress relief agent- The sealing material of the present disclosure may contain a stress relaxation agent such as silicone oil or silicone rubber particles as an additive. 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. Specifically, examples of the stress relaxation agent 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.

[0068] (Method of preparing the encapsulant) The method for preparing the encapsulating material is not particularly limited. A typical method includes thoroughly mixing each component with a mixer or the like, melt-kneading the components with a mixing roll, an extruder, or the like, cooling, and pulverizing the components. More specifically, the method includes stirring and mixing the components described above, kneading the components with a kneader, roll, extruder, or the like that has been heated to 70°C to 140°C in advance, cooling, and pulverizing the components.

[0069] (Characteristics of sealing material) When the encapsulating material of the present disclosure is made into a compression molded body, the non-black spot ratio is 86% or more, and from the viewpoint of suppressing wire sweep due to compression molding, it is preferably 89% or more, and more preferably 91% or more. As described above, a method for obtaining an encapsulant having a non-black spot ratio of 86% or more when made into a compression molded body can be, for example, a method of using a mixture of a first inorganic filler treated with a coupling agent and a second inorganic filler as an inorganic filler. When the above mixture is used as the inorganic filler, the non-black spot ratio when made into a compression molded body can be controlled by, for example, adjusting the type and amount of the coupling agent that treats the first inorganic filler.

[0070] The encapsulant of the present disclosure may be solid or liquid at room temperature and normal pressure (e.g., 25°C, atmospheric pressure), and is preferably solid. When the encapsulant is solid, the shape is not particularly limited, and examples thereof include powder, granules, and tablets. When the encapsulant is in tablet form, the dimensions and mass are preferably set to be suitable for the molding conditions of the package from the viewpoint of handling.

[0071] <Electronic component equipment> An electronic component device according to one aspect of the present disclosure includes an element encapsulated with the above-described encapsulant, that is, the electronic component device includes an element and a cured product of the encapsulant that encapsulates the element. Examples of electronic component devices include devices in which elements (active elements such as semiconductor chips, transistors, diodes, and thyristors, and passive elements such as capacitors, resistors, and coils) are mounted on a support member such as a lead frame, a pre-wired tape carrier, a wiring board, glass, a silicon wafer, or an organic substrate, and the resulting element portion is sealed with a sealing material. More specifically, typical resin-sealed ICs, such as DIP (Dual Inline Package), PLCC (Plastic Leaded Chip Carrier), QFP (Quad Flat Package), SOP (Small Outline Package), SOJ (Small Outline J-lead package), TSOP (Thin Small Outline Package), and TQFP (Thin Quad Flat Package), have a structure in which an element is fixed on a lead frame, and the terminal portion of the element, such as a bonding pad, and the lead portion are connected by wire bonding, bumps, or the like, and then sealed by a sealing material using compression molding or the like; TCP (Tape Carrier Package) has a structure in which an element connected to a tape carrier by bumps is sealed with a sealing material; and COB (Chip On Board) has a structure in which an element is connected to wiring formed on a support member by wire bonding, flip chip bonding, solder, or the like, and sealed with a sealing material. Examples of such modules include BGA (Ball Grid Array), CSP (Chip Size Package), MCP (Multi Chip Package), etc., which have a structure in which elements are mounted on the surface of a support member having terminals for connecting a wiring board formed on the back side thereof, the elements are connected to wiring formed on the support member by bump or wire bonding, and then the elements are sealed with a sealing material. Also, sealing materials can be suitably used in printed wiring boards.

[0072] The method for sealing the electronic component device with the sealing material is not particularly limited, and examples thereof include a general compression molding method. EXAMPLES

[0073] The above embodiment will be specifically described below using examples, but the scope of the above embodiment is not limited to these examples.

[0074] <Preparation of sealing material> First, the following components were prepared.

[0075] (A) Epoxy resin [Epoxy resin A1] jER YX-4000 (product name) manufactured by Mitsubishi Chemical Corporation [Epoxy resin A2] Epototo YSLV-80XY (product name) manufactured by Nippon Steel Chemical & Material Co., Ltd. [Epoxy resin A3] Nippon Kayaku Co., Ltd. EPPN-501HY (product name)

[0076] (B) Hardener [Hardening agent B1] MEH-7851 (product name) manufactured by Meiwa Kasei Co., Ltd. [Hardening agent B2] MEH-7500 (product name) manufactured by Meiwa Kasei Co., Ltd.

[0077] (C) Inorganic filler [Inorganic filler C1] Silica particles (first inorganic filler, volume average particle diameter 0.5 μm, specific surface area 5.5 m 2 / g, spherical silica) treated with a coupling agent (N-phenyl-3-aminopropyltrimethoxysilane, also known as γ-anilinopropyltrimethoxysilane, product name "KBM-573", 0.6 parts by mass per 100 parts by mass of silica particles) (mass loss at 800°C: 0.38%) [Inorganic filler C2] Silica particles (first inorganic filler, volume average particle diameter 0.5 μm, specific surface area 5.5 m 2 / g, spherical silica) treated with a coupling agent (3-methacryloxypropyltrimethoxysilane, also known as γ-methacryloxypropyltrimethoxysilane, product name "KBM-503", 0.7 parts by mass per 100 parts by mass of silica particles) (mass loss at 800°C: 0.41%) [Inorganic filler C3] Silica particles (first inorganic filler, volume average particle diameter 0.5 μm, specific surface area 5.5 m 2 / g, spherical silica) treated with a coupling agent (3-glycidoxypropyltrimethoxysilane, also known as γ-glycidoxypropyltrimethoxysilane, product name "KBM-403", 0.6 parts by mass per 100 parts by mass of silica particles) (mass loss at 800°C: 0.38%) [Inorganic filler C4] Silica particles (first inorganic filler, volume average particle diameter 0.5 μm, specific surface area 5.5 m 2 / g, spherical silica not treated with a coupling agent)

[0078] [Inorganic filler C5] Silica particles (second inorganic filler, volume average particle diameter 15 μm, specific surface area 4.0 m 2 / g, spherical silica) treated with a coupling agent (N-phenyl-3-aminopropyltrimethoxysilane, product name "KBM-573", 0.6 parts by weight per 100 parts by weight of silica particles) [Inorganic filler C6] Silica particles (second inorganic filler, volume average particle diameter 15 μm, specific surface area 4.0 m 2 / g, spherical silica not treated with a coupling agent) [Inorganic filler C7] Silica particles (first inorganic filler, volume average particle diameter 0.5 μm, specific surface area 5.5 m 2 / g, spherical silica) treated with a coupling agent (N-phenyl-3-aminopropyltrimethoxysilane, also known as γ-anilinopropyltrimethoxysilane, product name "KBM-573", 0.9 parts by mass per 100 parts by mass of silica particles) (mass reduction rate at 800°C: 0.73%) [Inorganic filler C8] Silica particles (first inorganic filler, volume average particle diameter 0.5 μm, specific surface area 5.5 m 2 / g, spherical silica) treated with a coupling agent (N-phenyl-3-aminopropyltrimethoxysilane, also known as γ-anilinopropyltrimethoxysilane, product name "KBM-573", 1.0 part by mass per 100 parts by mass of silica particles)

[0079] (D) Coupling agents as additives [Coupling agent D1] N-phenyl-3-aminopropyltrimethoxysilane (silane coupling agent, product name "KBM-573" manufactured by Shin-Etsu Chemical Co., Ltd. [Coupling agent D2] 3-methacryloxypropyltrimethoxysilane (silane coupling agent, product name "KBM-503", manufactured by Shin-Etsu Chemical Co., Ltd. [Coupling agent D3] 3-glycidoxypropyltrimethoxysilane (silane coupling agent, product name "KBM-403", manufactured by Shin-Etsu Chemical Co., Ltd. (E) Curing accelerator [Promoter E1] Adduct of tri-p-tolylphosphine and 1,4-benzoquinone

[0080] The components shown in Tables 1 and 2 were mixed in the amounts shown in the tables (units are parts by weight) and thoroughly mixed in a mixer, then melt-kneaded for 2 minutes at 100°C using a twin-screw kneader. Next, the melt was cooled, and the solid was pulverized into powder to prepare the desired powdered encapsulant. In the tables, blanks indicate that no components were mixed.

[0081] The content of the inorganic filler relative to the entire sealing material obtained is shown in Tables 1 and 2. Furthermore, for the resulting encapsulating material, the non-black spot ratio in the SAT image of the compression molded product obtained by the above-mentioned method is shown in Tables 1 and 2. In addition, when the volume-based particle size distribution of the inorganic filler contained in the obtained sealing material was determined by the above-mentioned method, it was found that the particle size distribution had maximum values ​​at 0.5 μm and 15 μm in all of the Examples and Comparative Examples. The resulting encapsulant was evaluated by the following tests. The evaluation results are shown in Tables 1 and 2.

[0082] <Evaluation of Spiral Flow Length> Using a spiral flow measurement mold conforming to the standard (EMMI-1-66), the obtained sealing material was subjected to a hydraulic pressure of 70 kgf / cm, which is the equivalent of the plunger bottom pressure. 2(6.86 MPa) and molded at 175°C for 120 seconds, the length of the molded product was recorded as the flow distance (spiral flow length). The flow distance in each Example and Comparative Example was calculated based on the flow distance in Comparative Example 1 being 100. The results are shown in Tables 1 and 2. Note that a larger converted value of the flow distance means a longer flow distance.

[0083] <Evaluation of wire sweep> The obtained sealing material was used in a compression molding machine (TOWA, PMC-1040) to seal a package under molding conditions of a molding temperature of 175°C and a molding time of 120 seconds, and then post-cured at 175°C for 5 hours to obtain a semiconductor device. This semiconductor device is a ball grid array (BGA) package (resin sealing part size: 228mm x 67mm x thickness 1mm), and the chip size is 7.5mm x 7.5mm. The gold wire has a diameter of 18μm and an average gold wire length of 5mm. The deformation state of the gold wire of the produced package was observed using a soft X-ray analyzer to check the presence or absence of deformation (deformation rate from the initial shape). Specifically, the maximum displacement of the wire was measured by X-ray, and the deformation rate was calculated by dividing the obtained maximum displacement value by the loop length and multiplying the value by 100, and this deformation rate was taken as the wire sweep rate.

[0084] The wire sweep ratio in each of the examples and comparative examples was calculated based on the wire sweep ratio in Comparative Example 1 being set at 100. The results are shown in Tables 1 and 2. Note that the smaller the converted value of the wire sweep ratio, the lower the wire sweep ratio.

[0085] [Table 1]

[0086] [Table 2]

[0087] The results in Tables 1 and 2 show that the sealing materials of the examples, in which the non-black spot ratio in the SAT image when formed into compression molded bodies was 86% or more, had a reduced incidence of wire sweep compared to the comparative examples.

[0088] The disclosure of International Patent Application No. PCT / JP2019 / 035934, filed September 12, 2019, is incorporated herein by reference in its entirety. 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. A compression molding encapsulant containing epoxy resin, a curing agent, and an inorganic filler, The inorganic filler is a mixture of a first inorganic filler having a volume-average particle diameter of 0.1 μm to 2 μm and treated with a coupling agent, and a second inorganic filler having a volume-average particle diameter greater than 2 μm. The mass loss rate of the first inorganic filler at 800°C is 0.27% to 0.73%. A compression molding encapsulant wherein, in an image obtained by observing a compression molded body obtained by compression molding the aforementioned compression molding encapsulant onto a substrate via a silicon chip using an ultrasonic flaw detection device, the area of ​​the region on the chip corresponding to the compression molded body, excluding black spots, is 86% or more of the total area of ​​the region on the chip corresponding to the compression molded body.

2. The compression molding encapsulant according to claim 1, wherein the content of the inorganic filler relative to the entire compression molding encapsulant is 75% by volume to 99% by volume.

3. The sealing material for compression molding according to claim 1, wherein the coupling agent is a silane coupling agent.

4. The compression molding encapsulant according to claim 1, wherein the coupling agent has at least one functional group selected from a (meth)acryloyl group, an epoxy group, and a phenyl group.

5. The coupling agent is a compression molding encapsulant according to claim 1, having a secondary amino group.

6. The inorganic filler has a maximum value in the volume-based particle size distribution between 0.1 μm and 2 μm, as described in claim 1.

7. An electronic component device comprising an element and a cured product of a compression molding encapsulant according to any one of claims 1 to 6 for sealing the element.