WO2019003600A1 - Sealing resin composition, electronic component, and electronic component manufacturing method - Google Patents

Abstract

Provided are: a resin composition that has a good external appearance without the occurrence of voids, that exhibits low moisture permeability as a cured product, that exhibits a low rate of change of capacitance, and that is suitable for manufacturing an electronic component that has superior reliability; and an electronic component employing said resin composition. A film capacitor 11 includes: a sealing resin composition that contains, as essential components, (A) a liquid epoxy resin, (B) a curing agent, (C) a curing accelerator, (D) a porous filler, and (E) an inorganic filler other than the porous filler (D); a film capacitor element 3; and a cured product 12 of the sealing resin composition which seals the film capacitor element 3.

Description

Resin composition for sealing, electronic component and method for manufacturing electronic component

The present invention relates to a resin composition for sealing, an electronic component and a method for manufacturing the electronic component, and in particular, a resin composition for sealing suitable for manufacturing a film capacitor excellent in low moisture permeability etc., a film capacitor and a method for manufacturing the same About.

In the conventional film capacitor manufacturing method, for both the foil type and the metallized type, first, the film is wound up to form a film capacitor element, and then the film capacitor element is subjected to heat pressing to narrow the distance between the films to reduce capacitance. To increase Furthermore, a method of impregnating a resin between films while replacing air inside the film capacitor element with a resin-dip epoxy resin by vacuum drawing was general (see, for example, Patent Document 1).

In addition, the film capacitor element is housed in an injection mold having a cavity recess capable of housing a film capacitor element, and the injection molding die is clamped to inject a polyphenylene sulfide resin into the cavity. There is also proposed a method of resin-sealing a film capacitor element housed inside to form an outer cover of the film capacitor element, and impregnating a resin between wound films of the film capacitor element (for example, a patent) Reference 2).

In addition, an epoxy resin composition in which an inorganic water-absorbing material is added to a composition having a predetermined range of a moisture diffusion coefficient of a cured product using an epoxy resin which has low moisture permeability of the cured product and is suitable as a pre-mold type hollow package material. Are known (see, for example, Patent Document 3).

Further, as a measure against moisture absorption, a hygroscopic layer is formed on part of the conductive layer in an electronic component such as a solid electrolytic capacitor (see, for example, Patent Document 4), and silica gel or the like is contained in solid epoxy resin (for example, Patent Document 5), etc. have been proposed.

Japanese Examined Patent Publication 5-77324 Japanese Patent Application Laid-Open No. 7-161578 Japanese Patent Laid-Open No. 7-216196 JP, 2017-59652, A Unexamined-Japanese-Patent No. 9-286845 gazette

However, in the method of Patent Document 1, although heat pressing is performed to increase the capacity, thermal stress and pressure stress are applied to the film forming the film capacitor element by this process, and the film is degraded to cause electrostatic There is a problem that the stability of the capacity and the impact resistance decrease.

In the method of Patent Document 2, since the pressure at the time of injection molding of PPS (polyphenylene sulfide) is a high pressure of 100 to 250 kgf / cm ² and a high temperature condition of 300 ° C. is required, damage to the film capacitor element is required. In order to prevent this, a process such as pre-sealing is required before the main sealing.

Although the epoxy resin which improved moisture permeability is proposed by patent document 3, this epoxy resin is not described about the application to a film capacitor, Moreover, since molding conditions are high temperature, 150-180 degreeC, When the film capacitor element is applied, the film capacitor element is deteriorated, so that it can not be diverted as it is.

In patent document 4, although a moisture absorption layer is formed in an outer layer, it is only and it is not described at all about the application to a film capacitor and the concrete composition of a resin composition, and sufficient moisture-proof hardening is not obtained.

In Patent Document 5, the type of the electronic component that can be sealed with a high resin viscosity is only applicable to a limited type, and application to a film capacitor element or the like is difficult.

The present invention has been made in view of such circumstances, and is a film capacitor excellent in reliability with no occurrence of voids, a good appearance, a low moisture permeability of a cured product, and a low rate of change in capacitance. It is an object of the present invention to provide a resin composition suitable for the production of the present invention, and a film capacitor using the resin composition.

As a result of repeated researches on film capacitors, the present inventors have found that the above problems can be solved by using a specific resin composition, and completed the present invention.

That is, the sealing resin composition of the present invention comprises (A) a liquid epoxy resin, (B) a curing agent, (C) a curing accelerator, (D) a porous filler, and (E) the above (D) ) An inorganic filler other than a porous filler is contained as an essential component.

The electronic component of the present invention is characterized in that the electronic element is sealed with the cured product of the sealing resin composition of the present invention.

Further, in the method of manufacturing an electronic component of the present invention, after the electronic element is placed in a mold and the mold is closed, the sealing resin composition of the present invention is injected into the mold; It is characterized in that it is cured and molded while applying pressure.

According to the sealing resin composition of the present invention, a material suitable for sealing an electronic element can be provided because the moldability is excellent, the cured product has low moisture permeability, and the change rate of capacitance is small.

According to the electronic component and the method of manufacturing the electronic component of the present invention, since the electronic element is sealed with the sealing resin composition, it has low moisture permeability, a small change rate of capacitance, and reliability. Can provide excellent electronic components. Thereby, the capacitor characteristic of the electronic component can also be improved.

It is a figure explaining the manufacturing method of the film capacitor of this embodiment. It is a figure explaining the manufacturing method of the film capacitor of this embodiment. It is a sectional view of a film capacitor of this embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The present invention is not limited at all by these embodiments.

[Resin composition for sealing]
First, the sealing resin composition of the present embodiment will be described. As described above, the sealing resin composition of the present embodiment includes (A) liquid epoxy resin, (B) curing agent, (C) curing accelerator, and (D) porous filler (E). The inorganic filler other than the (D) porous filler is contained as an essential component, and each of these components will be described below.

The liquid epoxy resin (A) used in the present embodiment is a liquid epoxy resin having one or more epoxy groups per molecule at room temperature, and preferably two or more epoxy groups per molecule. . Examples of such an epoxy resin include bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol AD epoxy resin, novolac epoxy resin, glycidyl ester epoxy resin, alicyclic epoxy resin, glycidyl ether and the like. Be These can be used alone or in combination of two or more.

As the curing agent (B) used in the present embodiment, any curing agent for the liquid epoxy resin (A) may be used without particular limitation as long as it is conventionally used as a curing agent for epoxy resin. be able to. Examples of the (B) curing agent include an acid anhydride curing agent, an amine curing agent, a phenol resin curing agent and the like. These can be used singly or in combination of two or more.

Among them, specific examples of the acid anhydride curing agent include tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyl hexahydrophthalic anhydride, etc. Specific examples of the amine curing agent Examples include isophorone diamine, 1,3-bis (aminomethyl) cyclohexane, bis (4-aminocyclohexyl) methane, norbornene diamine, 1,2-diaminocyclohexane, laromine and the like. Commercially available products include HN2000, HN5500 (manufactured by Hitachi Chemical), ancamine 1618, ancamine 2074, ancamine 2228 (manufactured by Air Products Japan), Daitoclar F-5194, Daitoclar B-1616 (made by Daito Sangyo), Fujicure FXD -821, Fujicure 4233 (manufactured by Fuji Kasei Kogyo Co., Ltd.), JER cure 113 (manufactured by Mitsubishi Chemical Corporation), Lamillon C-260 (manufactured by BASF Corporation), and the like. These can be used singly or in combination of two or more.

The amount of the curing agent (B) is preferably in the range of 0.7 to 1.3 equivalents of the curable functional group of the cured product (B) per equivalent of the epoxy group of the liquid epoxy resin (A). The range of 9 to 1.1 equivalents is more preferable. If the above range is exceeded, properties such as heat resistance, mechanical properties and moisture resistance of the cured product may be reduced.

The curing accelerator (C) used in the present embodiment is a known curing accelerator used in an epoxy resin curing system. Examples of the curing accelerator (C) include aromatic dimethylurea, aliphatic dimethylurea, 3- (3,4-dichlorophenyl) -1,1-dimethylurea (DCMU), and 3- (3-chloro-4). -Methylphenyl) -1,1-dimethylurea, urea such as 2,4-bis (3,3-dimethylureido) toluene, benzyldimethylamine, 1,8-diazabicyclo (5.4.0) undecen-7 , Tertiary amine compounds such as triethylamine, 2-ethyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 2-methylimidazole, 2-ethylimidazole, 2-isopropylimidazole, 2-phenylimidazole, 2 Imidazole compounds such as -phenyl-4-methylimidazole, triphenylphosphine salts etc. Phosphine salt compounds, and the like. These curing accelerators may be used alone or in combination of two or more. Among these, an imidazole-based curing accelerator can be preferably used from the viewpoint of low moisture permeability and humidity resistance.

The compounding amount of the (C) curing accelerator is 100 parts by mass of the total amount of the (A) liquid epoxy resin and the (B) curing agent from the viewpoint of the balance between the curing accelerating property and the physical properties of the cured resin, etc. It is usually in the range of about 0.1 to 10 parts by mass, preferably 0.4 to 5 parts by mass.

The (D) porous filler used in the present embodiment is a substance that can be used as a filler having a large number of fine pores, and has a specific surface area of 50 to 20000 m ² / g and an average pore size of 0.1 nm to 1000 nm. Have the following characteristics: As the (D) porous filler, for example, silica gel, cellulose, zeolite, molecular sieve, diatomaceous earth, perlite, etc. can be used without particular limitation as long as it is a porous filler having the above characteristics, and silica gel is preferable.

The (D) porous filler preferably has a specific surface area of 100 to 10000 m ² / g and an average pore diameter of 1 to 50 nm, and a specific surface area of 400 to 1000 m ² / g and an average pore diameter of 1 to 20 nm More preferable.

(D) If the specific surface area of the porous filler is less than 100 m ² / g, the adsorption efficiency will be low, and if it is more than 10000 m ² / g, the flowability at the time of injection may be reduced and unfilled parts may be generated. . In addition, when the average pore diameter of the (D) porous filler is less than 1 nm, the adsorption efficiency is low, and when it is more than 50 nm, good mechanical properties may not be obtained.

The specific surface area was calculated by the BET method by measuring the amount of adsorption by the gas adsorption method.

In addition, the average pore diameter was also measured using the specific surface area and total pore volume calculated from the BET method by measuring the adsorption amount by the gas adsorption method.

The average particle diameter of the (D) porous filler is preferably 0.5 to 100 μm, and more preferably 1 to 50 μm. In the present specification, the average particle diameter is obtained by measuring a particle size distribution based on volume using a laser scattering particle size distribution analyzer (for example, LA-920 (trade name, manufactured by Horiba, Ltd.) etc.) Indicates the 50% integrated value (50% particle size).

The porous filler (D) is preferably contained in an amount of 1 to 10% by mass, preferably 2 to 5% by mass, based on the total amount of the resin composition. If the amount of the porous filler is less than 1% by mass, the moisture permeation resistance may be insufficient. On the other hand, when it is more than 10% by mass, the viscosity of the resin composition is increased, the fluidity at the time of injection is decreased, and there is a possibility that an unfilled portion may be generated.

The inorganic filler other than the (E) porous filler used in the present embodiment is a known inorganic filler to be blended in the resin composition, and it is other than the above (D) porous filler It is not particularly limited. Examples of the (E) inorganic filler include silica, alumina, silicon nitride, boron nitride, magnesia, boehmite, calcium carbonate, aluminum hydroxide, talc and the like. As the (E) inorganic filler, silica powder is preferably used, and in particular, use of spherical silica powder is preferable. The (E) inorganic filler may be used alone or in combination of two or more.

The compounding amount of the (E) inorganic filler is preferably 50 to 85% by mass, preferably 70 to 85% by mass, based on the total amount of the resin composition. If the compounding amount of the (E) inorganic filler is less than 50% by mass, distortion or breakage of a structure such as an electronic element or an electrode due to shrinkage of a cured product may easily occur, and moisture permeation resistance may be insufficient. On the other hand, when the compounding amount is more than 85% by mass, the flowability at the time of injection is lowered, and unfilled portions are generated, which is not preferable. The thermal shock resistance of hardened | cured material, mechanical strength, and a flame retardance become favorable for it to be in the said range.

The average particle diameter of the (E) inorganic filler used here is preferably 0.5 to 100 μm, more preferably 10 to 30 μm.

Moreover, as the (E) inorganic filler in the present embodiment, it is preferable to use two or more types of fillers having the same material but different average particle sizes, because the flowability at the time of injection becomes good. For example, based on 100% by mass of the whole (E) inorganic filler, 70 to 90% by mass of spherical fused silica having an average particle size of more than 15 μm and 25 μm or less and 10 to 30 spherical fused silica having an average particle size of 1 to 5 μm It is more preferable to contain in the range of mass%. When spherical fused silica is used, it is particularly preferable to constitute the (E) inorganic filler only with the above-mentioned spherical fused silica.

In addition, when using together the spherical fused silica from which the above-mentioned average particle diameter differs, although it can also contain other inorganic fillers besides that, in that case, silica powder which consists of fusion crushing silica and crystalline silica for the remaining filler It is preferable from the viewpoint of low water absorption and low moisture permeability of the cured product. When it mix | blends out of this range, since the fluidity | liquidity at the time of injection | emission will fall and an unfilled part may generate | occur | produce, it is unpreferable.

Further, the total amount of the component (D) and the component (E) is preferably in the range of 51 to 95% by mass, preferably in the range of 77 to 90% by mass, based on the total weight of the resin composition. If the amount is less than 51% by mass, the low water absorption and low moisture permeability of the cured product may be insufficient. If the amount is more than 95% by mass, the flowability at the time of injection may be reduced and unfilled portions may be generated.

In the resin composition of the present embodiment, a coupling agent (for example, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, etc.) to the extent that the effects of the present invention are not inhibited. , Mold release agents (eg, synthetic waxes, natural waxes, linear aliphatic metal salts, acid amides, esters, etc.), colorants (eg, carbon black, cobalt blue, etc.), low stressing agents (eg, silicones) Oil, silicone rubber, etc.), an antifoamer, etc. may be further blended.

In the resin composition for sealing of the present embodiment, after thoroughly mixing the components (A) to (E) described above and the components to be blended according to need, roll kneading such as a three-roll kneader or the like, or It can be easily manufactured by a conventionally known method in which the kneading treatment is carried out by mixer kneading and the like and then the pressure is removed under reduced pressure.

At this time, the resin composition of the present embodiment preferably has a viscosity at 60 ° C. of less than 100 Pa · s. By setting it as such a viscosity, especially in the injection molding method using a liquid epoxy resin, sealing and molding can be performed favorably. On the other hand, if the viscosity is 100 Pa · s or more, the flowability at the time of injection in the molding operation may be reduced, and there may be an unfilled portion.

Further, in the resin composition of the present embodiment, the gel time at 100 ° C. is preferably 5 to 30 minutes. When the gel time is 5 minutes or less, voids are easily generated in the cured product, and when the gel time is 30 minutes or more, the shape retention of the cured product is deteriorated.

According to this embodiment, it is possible to provide an electronic component such as a film capacitor which exhibits stable capacitance, low moisture permeability and good appearance, and such an electronic component is excellent in reliability. is there.

[Electronic parts]
The electronic component of the present embodiment has an electronic element, and the electronic element is sealed with the cured product of the sealing resin composition of the present embodiment.

As an electronic element used here, a film capacitor element, an electrolytic capacitor element, a ceramic capacitor element, etc. are mentioned. A film capacitor element is preferable as the electronic element. Moreover, as a hardened | cured material used here, the hardening process of the resin composition for sealing demonstrated above is carried out, and the said electronic device is sealed.

Moreover, in manufacturing this electronic component, after installing an electronic element in a metal mold | die and closing a metal mold | die, the resin composition for sealing of this embodiment is inject | poured in a metal mold | die, An injection molding method may be used in which the resin composition for sealing injected into the above is molded while being cured under pressure. Except the sealing resin composition to be used, it can manufacture by a conventionally well-known method.

Hereinafter, the case of manufacturing a film capacitor will be described with an example of using a film capacitor element as an electronic element.

1A and 1B are diagrams for explaining a method of manufacturing a film capacitor of the present embodiment. Here, a mold used for manufacturing a film capacitor is composed of a lower mold 1 and an upper mold 2, and in this mold, a recess is formed in each of the lower mold 1 and the upper mold 2. The recess is a cavity. The resin composition melted in this cavity is used for injection molding to produce a film capacitor.

First, as shown in FIG. 1A, the film capacitor element 3 is disposed in the recess of the lower mold 1 having a recess of a predetermined shape and temperature controlled, and the injection nozzle of the liquid epoxy resin composition 4 thereon While covering the upper mold 2 having 5 and sealing the joint with the lower mold 1 in an airtight manner, the inside of the cavity formed by the lower mold 1 and the upper mold 2 is vacuum pump etc. (not shown) The pressure is reduced by vacuum to reach 10 Torr. Here, the injection nozzle 5 is connected to a sprue for introducing the resin provided in the upper mold 2 into the cavity at the tip end portion 5c, and the entire nozzle is configured to be vertically movable up and down. Further, the nozzle tip 5c can be opened and closed by raising and lowering a plunger 5b disposed concentrically in the nozzle main pipe 5a.

Then, as shown in FIG. 1B, when the inside of the cavity is maintained at a certain degree of pressure reduction, the tip 5c of the injection nozzle 5 is opened, and the liquid epoxy resin composition 4 is used as the lower mold 1 and the upper mold 2 Eject into the cavity between After filling the cavity with liquid epoxy resin composition 4 by injection, lower mold 1 and upper mold 2 are heated to a suitable temperature to be cured and electrode terminal 3a of film capacitor element 3 is the upper mold. Between the lower mold 1 and the lower mold 1 is held without gap.

When the curing is completed, the lower mold 1 and the upper mold 2 are opened to take out a film capacitor which is a molded product. The film capacitor 11 obtained here has, for example, as shown in FIG. 2, a configuration in which the film capacitor element 3 is covered and protected with a cured product 12 of a liquid epoxy resin composition, and the electrode 3a is The end of the end projects out of the cured product 12 so that it can be connected to other devices.

Here, the film capacitor element 3 is a capacitor formed by winding a film and an electrode foil, and the metal electrodes 3a are projected in parallel from the upper and lower surfaces thereof so as to extend in the reverse direction with respect to the capacitor body. There is. The illustrated film capacitor element 3 is an example, and as the film capacitor element 3 in the present embodiment, any known film capacitor element can be used without particular limitation.

As described above, in the manufacturing method of the present embodiment using injection molding, the supply of the liquid epoxy resin composition 4 to the film capacitor 3 and the sealing molding can be continued continuously and efficiently performed. A sealed molded article free of voids and having a good appearance can be obtained. Thus, when using a thermosetting resin, after setting injection temperature to low temperature, it is preferable to be filled with a high temperature metal mold and to harden it.

As a condition for injection filling, an injection temperature of 50 to 70 ° C. is preferable. If it is less than 50 ° C., the fluidity will be poor. On the other hand, if the temperature is higher than 70 ° C., it is not preferable because a curing reaction partially proceeds in the injection nozzle. The filling rate is preferably 0.2 to 5.0 L / min. It is unpreferable from the viewpoint of productivity as it is less than 0.2 L / min. On the other hand, if it is 5.0 L / min, there is a possibility that a resin winding void may occur in the sealing molded body, which is not preferable.

As the pressurizing condition, the pressure (holding pressure) is preferably 0.2 to 10 MPa. If it is less than 0.2 MPa, unfilled parts and voids occur. On the other hand, if the pressure is higher than 10 MPa, the film capacitor element is broken.

The injection nozzle or the like may be equipped with a heating means such as a heater capable of heating the resin to a desired temperature for maintaining the resin.

The heat curing of the resin composition is preferably carried out at 90 to 110 ° C. for about 5 to 25 minutes. Within this range, the curing reaction proceeds slowly, and the voids of the film capacitor element are uniformly impregnated and filled with the resin composition.

The temperature of the mold is preferably 90 to 120.degree. Below 90 ° C., insufficient curing occurs. On the other hand, if the temperature is higher than 120 ° C., the film capacitor element is damaged by heat. The lower mold 1 and the upper mold 2 are preferably made of a metal such as stainless steel having heat resistance and corrosion resistance.

Furthermore, it is preferable to take out from a shaping | molding die and to post-cure as needed, and this post-curing is performed on the conditions of 100 degreeC and 2 hours, for example.

In this way, it is possible to obtain a capacitor device having a good appearance without any unfilled portion or void. Furthermore, the capacitor device obtained in this manner is a device that is excellent in any of various characteristics such as moisture permeability, change in capacitance, and the like, and has high reliability.

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples.

(Examples 1 to 9)
Each raw material of the compounding composition (mass part) shown in Table 1 and Table 2 was stirred and mixed uniformly, and the liquid epoxy resin composition was prepared.

Next, 12 film capacitor elements (60 mm × 35 mm, thickness 60 mm) are accommodated and arranged at predetermined positions of the lower mold recess, and the upper mold is put in place and the mold is closed. The liquid epoxy resin composition prepared above was introduced into the main nozzle of the injection nozzle, and the inside of the cavity between the lower mold and the upper mold was allowed to reach 10 Torr by a vacuum pump. Next, the plunger is raised, and the resin composition is injected and filled into the cavity at a filling speed of 0.5 L / min and an injection temperature of 60 ° C. Then, the lower mold and the upper mold are heated under a predetermined pressure, 110 ° C. The resin composition was heated and cured under the conditions of 20 minutes, and the electrode terminal of the film capacitor element was sandwiched between the upper mold and the lower mold without a gap. Thereafter, the mold was opened, the cured product was taken out of the mold, and post curing was performed under conditions of 100 ° C. for 2 hours to produce a film capacitor (200 mm × 250 mm, thickness 70 mm) (E-LIM ( Epoxy-Liquid Injection Molding) method. The evaluation results of the various characteristics in each example are shown together in Table 1 and Table 2.

(Comparative Examples 1 to 3)
Each raw material of the composition (mass part) shown in Table 2 was uniformly stirred and mixed to prepare a liquid epoxy resin composition. Further, a film capacitor having the same configuration and size as those of the above-described example was manufactured by the same E-LIM method as in the example, potting in the comparative example 2, and transfer molding in the comparative example 3.

In addition, each raw material component used is as follows.
[(A) Epoxy resin]
Epoxy resin 1: R140P (Bisphenol A type epoxy resin manufactured by Mitsui Chemicals, Inc., trade name)
Epoxy resin 2: BREM-105 (Broked epoxy resin manufactured by Nippon Kayaku Co., Ltd., trade name)
Epoxy resin 3: EPOXAN (Shin-Etsu Chemical silicone modified epoxy resin, trade name)
[(B) curing agent]
Hardening agent 1: HN 2000 (Mityl tetrahydrophthalic anhydride manufactured by Hitachi Chemical Co., Ltd., trade name)
Curing agent 2: NH-7000 (phenol resin manufactured by Nippon Kayaku Co., Ltd., trade name)
Curing agent 3: XL225-3L (Phenolic resin manufactured by Mitsui Chemicals, Inc., trade name)
[(C) curing accelerator]
2E4MZ (Imidazole manufactured by Shikoku Kasei Co., Ltd., trade name)

[Additive]
Antifoaming agent: TSA720 (manufactured by Momentive Performance Materials Japan, product name)
Silane coupling agent: A-187 (3-glycidoxypropyltrimethoxysilane manufactured by Nippon Unicar, trade name)
Carbon black: MA600 (Mitsubishi Chemical Corporation, trade name)

[(E) Inorganic filler]
Inorganic filler 1: HS-106 (Spherical fused silica manufactured by Micron, trade name; spherical, average particle diameter 18.2 μm)
Inorganic filler 2: SO-C6 (Spherical fused silica manufactured by Adma Fine, trade name; spherical, average particle size 2.2 μm)

[(D) porous filler]
Porous filler 1: Mizukasil P-73 (silica gel manufactured by Mizusawa Chemical Industry, trade name; average particle diameter 4 μm, specific surface area 330 m ² / g, average pore diameter 14 nm)
Porous filler 2: Mizukasil P-50 (silica gel manufactured by Mizusawa Chemical Industry, trade name; average particle diameter 10 μm, specific surface area 330 m ² / g, average pore diameter 13 nm)
Porous filler 3: Sycilia 730 (silica gel manufactured by Fuji Silysia Chemical Ltd., trade name; average particle diameter 4 μm, specific surface area 700 m ² / g, average pore diameter 2.5 nm)
Porous filler 4: Sycyria 350 (silica gel manufactured by Fuji Silysia Chemical Ltd., trade name; average particle diameter 4 μm, specific surface area 300 m ² / g, average pore diameter 21 nm)

[Characteristics test]
(1) Viscosity In accordance with the viscosity measurement method of JIS C 2105, rotor No. 1 was measured by a BROOK FIELD viscometer (part number: DV-II). The viscosity of the obtained resin composition was measured under the conditions of a temperature of 60 ° C. and a rotation speed of 10 rpm using 34 spindle.

(2) Moisture Permeability The disk-shaped sample (diameter 60 mm × thickness 2 mm) prepared by curing the obtained resin composition at 100 ° C. for 5 hours was subjected to the cup method (JIS L 1099) 85 ° C. / in 85% RH to calculate the mass change amount in the environment of 300 hours, based on the value, the weight increase of 1 m ² per 24 hours was calculated as the evaluation properties of moisture permeability of the cured product. As the value is smaller, the permeation of water can be suppressed, and it can be evaluated that it is suitable for sealing because it is 1.5 mg / cm ² · 24 hr or less.

(3) Molded Appearance The molded film capacitor was arbitrarily cut, and the presence or absence of voids on the cut surface was visually confirmed.

(4) Capacitance With the film capacitor after molding, the capacitance between the package (PKG) electrode after the treatment in an environment of 85 ° C./85% RH for 1000 hours was measured before and after the treatment. Furthermore, the rate of change was calculated from the capacitance before and after the treatment. The rate of change can be evaluated on the basis of the following criteria.
Good: Change rate less than 5% Allowed: Change rate 5% or more and less than 10% Not possible: Change rate 10% or more

As apparent from Tables 1 and 2, according to the present embodiment, the moisture permeability is small, the change rate of the capacitance after the moisture resistance test is small, and the appearance is further reduced by using the specific epoxy resin composition. It turned out that a favorable molded object is obtained.

DESCRIPTION OF SYMBOLS 1 ... Lower mold, 2 ... Upper mold, 3 ... Film capacitor element, 4 ... Liquid epoxy resin composition, 5 ... Injection | pouring nozzle, 11 ... Film capacitor, 12 ... Cured | curing material.

Claims (8)

(A) liquid epoxy resin,
(B) a curing agent,
(C) a curing accelerator,
(D) porous filler,
(E) an inorganic filler other than the (D) porous filler;
A sealing resin composition comprising as an essential component. The (B) curing agent is an acid anhydride, and the (D) porous filler is a silica gel,
The sealing resin composition according to claim 1, wherein the content of the (D) porous filler is 1 to 10% by mass with respect to the total amount of the resin composition. The sealing resin composition according to claim 1 or 2, wherein the specific surface area of the (D) porous filler is 100 to 1000 m ² / g and the average pore diameter is 1 to 50 nm. An electronic component characterized in that the electronic element is sealed with the cured product of the sealing resin composition according to any one of claims 1 to 3. The electronic device according to claim 4, wherein the electronic device is a film capacitor device. After installing the electronic element in the mold and closing the mold,
The sealing resin composition according to any one of claims 1 to 3 is injected into the mold, and is cured while being applied with pressure.
A method of manufacturing an electronic component characterized by The method of manufacturing an electronic component according to claim 6, wherein the electronic device is a film capacitor device. The method according to claim 6 or 7, wherein the pressure (holding pressure) is 0.2 MPa or more and 10 MPa or less.

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