JP5290515B2 - Epoxy resin composition for sealing electronic parts and resin-sealed electronic parts using the same - Google Patents

Description

  The present invention relates to an epoxy resin composition for sealing an electronic component used for sealing an electronic component, and a resin-encapsulated electronic component using the same.

When a liquid epoxy resin composition is used as a semiconductor encapsulant, the liquid epoxy resin composition generally has fluidity, so that the shape is maintained so as not to diffuse from the region to be sealed at the time of curing. Is required. In order to meet this requirement, it has been proposed to increase thixotropy by adding inorganic particles as a thixotropic agent. However, in this method, it is necessary to mix a large amount of inorganic particles, which causes a problem that the viscosity is remarkably increased and workability is deteriorated. For this reason, a method of blending a fatty acid amide compound and polyethylene oxide as an organic thixotropic agent has been proposed (see, for example, Patent Document 1).
JP 2002-284846 A

  However, as electronic parts are being mounted at higher density, electronic parts are being made smaller and thinner, and in the epoxy resin composition for electronic parts sealing, only necessary parts are efficiently sealed with a sealing material. In reality, a sealing material with improved shape retention and workability that can be coated is desired. Although the method of the above-mentioned Patent Document 1 is excellent in workability, shape retention is not sufficient.

  This invention makes it a subject to provide the epoxy resin composition for electronic component sealing which improved both shape retainability and workability | operativity from the background as mentioned above.

  The present invention is characterized by the following in order to solve the above problems.

First, the epoxy resin composition for encapsulating electronic components of the present invention comprises an epoxy resin, a solid particulate amine adduct curing agent having an average particle size of 10 μm or less, an inorganic filler, an amide wax and an oxidized polyethylene wax. An epoxy resin composition for encapsulating electronic components that is liquid at room temperature and contained as an essential component, wherein the compounding amount of the amine adduct curing agent is in the range of 20 to 48 parts by mass with respect to 100 parts by mass of the epoxy resin. The total amount of the system wax and the oxidized polyethylene wax is 3 to 15% by mass with respect to the epoxy resin.

Second , in the first epoxy resin composition for sealing an electronic component, the gel time at 150 ° C. is 5 to 40 sec.

Thirdly, in the first or second epoxy resin composition for sealing an electronic component, a viscosity at 25 ° C. is in a range of 200 to 800 Pa · s .
Fourth, in the fourth one of the electronic components for encapsulating epoxy resin composition from the first, mixing ratio of the oxidized polyethylene wax and the amide wax has a weight ratio of 1: 6 to 6: 1 It is the range of these.

Fifth, the resin-encapsulated electronic component is characterized by being sealed with a cured body of any of the above-described epoxy resin compositions for encapsulating electronic components.

According to the first and fourth aspects of the invention, it is possible to obtain an epoxy resin composition for encapsulating electronic components that is suitable for high-density mounting of electronic components and has improved shape retention and workability.

According to the second and third aspects of the invention, the effects of the invention are realized as being even better.

The remarkable effects as described above are realized as the resin-encapsulated electronic component of the fifth invention.

  The present invention has the features as described above, and the best mode for carrying out the present invention will be described below.

  As described above, the epoxy resin composition for sealing an electronic component of the first invention comprises an epoxy resin, an average particle diameter of 10 μm or less, particularly a solid particulate curing agent having 1 to 10 μm, an inorganic filler, and an amide wax. It is an epoxy resin composition that contains an essential component and is liquid at normal temperature, that is, a paste-like or viscous fluid liquid in a normal room temperature range of 15 to 26 ° C.

  As the epoxy resin in the first invention, for example, representative one or two kinds of liquid epoxy resins such as bisphenol A type, bisphenol F type, hydrogenated bisphenol A type, bisphenol AF type, phenol novolac type, etc. It may be above and is not specifically limited. Alternatively, any one of those derivatives, a liquid epoxy resin derived from a polyhydric alcohol and epichlorohydrin, various glycidyl type epoxy resins, or a derivative thereof may be used. Especially, in the epoxy resin composition of this invention, a bisphenol A type epoxy resin is considered as a suitable thing.

  As the curing agent in the present invention, a solid particulate curing agent having an average particle size of 10 μm or less is used. As a result, the curing agent particles can be uniformly dispersed, the composition tends to be uniform even if any part of the minimum is taken, and it is highly reactive and is most likely to solidify the earliest. When the average particle size exceeds 10 μm, even if the added weight is equal to or less than 10 μm, the bulk becomes small and the probability of the main ingredient component coming into contact with the curing agent decreases, and only the main ingredient component penetrates, thereby causing the present invention to penetrate. The expected effect is not obtained. In addition, there is a limit to increasing the reactivity and facilitating solidification. If it is a liquid such as an acid anhydride curing agent, it is excellent in compatibility with the main agent, but penetrates until solidification, and the desired effect of the present invention cannot be obtained. . In addition, the slow reactivity also affects the penetration until solidification.

  About the lower limit of the average particle diameter of the curing agent in the present invention, about 1 μm is considered. If the thickness is less than 1 μm, the bulk is so large that the liquid state of the epoxy resin composition may not be obtained. Moreover, a desired addition amount cannot be blended, and there is a possibility that a reaction may occur during blending / mixing, which is not preferable.

  As a kind of hardening | curing agent, although an amine adduct type | system | group hardening | curing agent can be mentioned as a suitable thing, for example, it is not specifically limited. About the compounding quantity, when the average particle diameter of a hardening | curing agent is considered, it is preferable to mix | blend in the ratio of 20-50 mass parts with respect to 100 mass parts of epoxy resins, for example.

  In the first invention, an inorganic filler is blended for the purpose of improving thixotropy and lowering the thermal expansion coefficient. Examples of such inorganic fillers include conventionally known materials such as fused silica, crystalline silica and other silica powders, alumina powder, silicon nitride powder, magnesia powder, aluminum hydroxide powder, and the like. One or more of these are used in combination. The average particle diameter of the inorganic filler is preferably 50 μm or less, particularly preferably in the range of 5 to 30 μm from the viewpoint of handleability and workability, and the blending amount thereof is the total amount of the epoxy resin composition for electronic component sealing. It is preferably 85% by mass or less.

  In the first invention, an amide wax is blended as a wax component in the range of 3 to 15% by mass with respect to the epoxy resin. If it is less than 3% by mass, the effect of improving thixotropy is small and the shape retention cannot be sufficiently improved. If it exceeds 15% by mass, the heat resistance of the cured product is lowered and workability is lowered. The desired effect of the present invention cannot be obtained. Such an amide wax is not particularly limited, and commercially available ones can be used. For example, Disparon 6700 manufactured by Enomoto Kasei Co., Ltd. used in the examples is suitable because it can be easily mixed into the main agent.

  In addition, as a second invention, in addition to an epoxy resin, a solid particulate curing agent having an average particle diameter of 1 to 10 μm, an inorganic filler, an amide wax, and an electronic component sealing containing polyethylene oxide wax as an essential component An epoxy resin composition is also provided. By using the oxidized polyethylene wax in combination as the wax component, the fluidity can be further suppressed with the same addition amount as the wax component of the first invention, and the shape retention and workability can be further improved. Here, since the epoxy resin, the curing agent, and the inorganic filler are the same as those of the first invention, description thereof is omitted.

  In the second invention in which the amide wax in the first invention plus an oxidized polyethylene wax is used as the wax component, the total amount of these blends is in the range of 3 to 15% by mass with respect to the epoxy resin. . If it is less than 3% by mass, the effect of improving thixotropy is small and the shape retention cannot be sufficiently improved. If it exceeds 15% by mass, the heat resistance of the cured product is lowered and workability is lowered. The desired effect of the present invention cannot be obtained. The blending ratio of the amide wax and the oxidized polyethylene wax is not particularly limited as long as the total blending amount is in the range of 3 to 15% by mass with respect to the epoxy resin. : 6-6: 1 range may be sufficient.

  In the epoxy resin composition for sealing an electronic component according to the first and second inventions described above, the gel time at 150 ° C. is 5 to 40 sec and the viscosity at 25 ° C. is in the range of 200 to 800 Pa · s. Is done. Thereby, shape retainability and workability | operativity can be implement | achieved as a still more favorable thing. When the gel time at 150 ° C. is less than 5 seconds or when the viscosity at 25 ° C. exceeds 800 Pa · s, workability is lowered, and the desired effect of the present invention cannot be obtained sufficiently. In addition, when the gel time at 150 ° C. exceeds 40 sec, or when the viscosity at 25 ° C. is less than 200 Pa · s, sufficient shape retention cannot be ensured, and the desired effect of the present invention can be sufficiently obtained. It is not preferable because it cannot be done.

  In the epoxy resin composition for sealing an electronic component according to the first and second inventions, for example, a curing accelerator, a flame retardant, a flame retardant aid, a colorant, etc. It is also possible to mix appropriately as long as the target characteristics are not impaired.

  To prepare the epoxy resin composition for encapsulating a liquid electronic component according to the present invention as described above, first, an amide wax or a wax component of an amide wax and oxidized polyethylene and an epoxy resin are used, for example, at 100 ° C to 120 ° C. And mixing with heat treatment for about 3 to 5 hours. After cooling to 30 ° C. or lower, other components are added and mixed and kneaded. Mixing and kneading can be performed by mixing and dispersing using a roll, a mixer, etc., and degassing under reduced pressure as necessary.

  In sealing an electronic component using the epoxy resin composition for sealing an electronic component of the present invention obtained as described above, the epoxy resin composition for sealing an electronic component is placed at a location to be sealed. After application, this is heat cured. As a target of sealing, a connection part such as a connection terminal of various electronic components of the surface mount product can be a suitable target. As a method for coating, various methods such as a dispenser coating method may be used. As the heating conditions for curing, the temperature and time can be set in consideration of the reaction start temperature of the epoxy resin. For example, it can be heated at 80 to 110 ° C. for several minutes.

  Hereinafter, examples will be shown and described in more detail. Of course, the present invention is not limited to the following examples.

<Examples 1-7 and Comparative Examples 1-6>
The following compounding components were mixed and dispersed by the above method to prepare epoxy resin compositions for sealing electronic components of Examples 1 to 7 and Comparative Examples 1 to 6 shown in Table 1. Table 1 shows the amount of each component (parts by mass).
Inorganic filler (silica): fused silica SE15 (average particle size 15 μm) manufactured by Tokuyama Corporation
Epoxy resin: Bisphenol A type epoxy resin Epicoat 828 manufactured by Japan Epoxy Resin Co., Ltd.
-Curing agent: A MH700 (liquid) manufactured by Shin Nippon Rika Co., Ltd.
B PN-H (average particle diameter 10 μm) manufactured by Ajinomoto Fine Techno Co., Ltd.
C PN-23J (average particle size 2 μm) manufactured by Ajinomoto Fine Techno Co., Ltd.
D PN-H (average particle diameter 12 μm) manufactured by Ajinomoto Fine Techno Co., Ltd.
Curing accelerator: Asahi Kasei Chemicals Corporation HX3742
-Amide wax: Disparon 6700 manufactured by Enomoto Kasei Co., Ltd.
・ Oxidized polyethylene wax Honeywell International Inc A-C629A
-Pigment: Carbon black Using the epoxy resin compositions prepared as described above, evaluation was performed by the following method.
<Viscosity (Pa · s)>
About each composition, it rotated at 5 rpm using the rotational viscometer (No. 7 rotor) at 25 degreeC, and measured the viscosity after 60-second rotation.
<Tixo index>
For each composition, the viscosity at a rotational speed of 5 rpm and the viscosity at a rotational speed of 0.5 rpm were measured using a B-type rotational viscometer (No. 7 rotor), and the viscosity ratio n (0.5) / n (5 ).
<Bleed amount>
As shown in FIG. 1, the prepared epoxy resin composition is dropped onto one end of two glass plates bonded together with an interval of 20 μm. After this is cured, the penetration distance (bleed amount) of the epoxy resin composition into the gap formed between the two glass plates is measured. If the penetration distance was within 1 mm, it was evaluated as shape retention OK.
<150 ° C gel time>
0.3 g of the prepared epoxy resin composition was cured at 150 ° C., and when the resin state was no longer tacky, the time measurement was terminated and the gel time was determined.
<Workability>
Those having a viscosity up to 800 (Pa · s) were judged as “◯”, and those exceeding the viscosity were judged as “×”.
<Judgment>
A workability of “◯” and a bleed amount of 1 mm or less were designated as “◯”, and other cases were designated as “X”.
The results are shown in Table 1.

表１によれば、エポキシ樹脂、平均粒子径が１０μｍ以下の固体粒子状の硬化剤、無機充填材およびアマイド系ワックスを含有し、アマイド系ワックスがエポキシ樹脂に対して３〜１５質量％の範囲で配合されているエポキシ樹脂組成物（実施例１〜３、実施例６〜７）と、さらに酸化ポリエチレンが配合され、アマイド系ワックスと酸化ポリエチレンワックスの配合量の合計がエポキシ樹脂に対して３〜１５質量％の範囲であるエポキシ樹脂組成物（実施例４〜５）については、形状保持性と作業性がともに良好であることが確認された。

According to Table 1, it contains an epoxy resin, a solid particulate curing agent having an average particle size of 10 μm or less, an inorganic filler and an amide wax, and the amide wax is in the range of 3 to 15% by mass with respect to the epoxy resin. And the epoxy resin composition (Examples 1 to 3, Examples 6 to 7) blended with the above, and oxidized polyethylene are further blended, and the total blended amount of the amide wax and the oxidized polyethylene wax is 3 with respect to the epoxy resin. About the epoxy resin composition (Examples 4-5) which are the range of -15 mass%, it was confirmed that both shape retainability and workability | operativity are favorable.

  On the other hand, the epoxy resin, the epoxy resin composition (Comparative Examples 1 to 3) that does not contain the solid particulate curing agent having an average particle size of 10 μm or less, the inorganic filler, and the amide wax as essential components are retained in shape. It was confirmed that either or both of workability and workability were not sufficient. In addition, an epoxy resin composition (Comparative Examples 4 and 5) in which the amide wax is not blended in the range of 3 to 15% by mass with respect to the epoxy resin or a solid particulate curing agent having an average particle size exceeding 10 μm is used. As for the epoxy resin composition (Comparative Example 6), it was confirmed that either one or both of shape retention and workability were not sufficient.

It is a schematic diagram for demonstrating the measurement of the bleed amount in an Example.

Claims (5)

Epoxy resin, epoxy resin composition for encapsulating electronic components which is liquid at room temperature, containing an amine adduct curing agent in the form of solid particles having an average particle size of 10 μm or less, an inorganic filler, an amide wax and an oxidized polyethylene wax as essential components The compounding amount of the amine adduct curing agent is in the range of 20 to 48 parts by mass with respect to 100 parts by mass of the epoxy resin, and the total of the compounding amounts of the amide wax and the oxidized polyethylene wax is 3 with respect to the epoxy resin. An epoxy resin composition for sealing electronic parts, characterized by being in the range of ˜15% by mass.   The epoxy resin composition for electronic component sealing according to claim 1, wherein the gel time at 150 ° C. is 5 to 40 sec.   The epoxy resin composition for sealing electronic parts according to claim 1 or 2, wherein the viscosity at 25 ° C is in the range of 200 to 800 Pa · s. The electronic component seal according to any one of claims 1 to 3, wherein a mixing ratio of the amide wax and the oxidized polyethylene wax is in a range of 1: 6 to 6: 1 by weight. Stopping epoxy resin composition. A resin-encapsulated electronic component that is sealed with a cured body of the epoxy resin composition for encapsulating an electronic component according to any one of claims 1 to 4.

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