JPH059268A - Epoxy resin composition for sealing optical semiconductor - Google Patents

Abstract

PURPOSE:To obtain the title composition excellent in adhesiveness, transparency, and crack resistance by incorporating a mixture of an acid salt of 1, 8- diazabicyclo[5,4,0]undecene-7 with an organoaluminum compound at a specified ratio as a cure accelerator. CONSTITUTION:The title composition consists essentially of an epoxy resin (A), a phthalic anhydride (B), an acid salt (C) of 1, 8- diazabicyclo[5,4,0]undecene-7 and an organoaluminum compound (D), wherein the total amount of components C and D is 0.3-6 pts.wt. based on 100 pts.wt. component B and the weight ratio of component C to component D is (1:1) to (1:5).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an epoxy resin composition for encapsulating a light emitting element, a light receiving element or the like, which is excellent in crack resistance, adhesiveness and transparency and has good transparency.

[0002]

2. Description of the Related Art Conventionally, a light emitting device such as a light emitting diode is sealed with a transparent resin and used for various displays. A liquid transparent epoxy resin is used as the sealing resin. Most of this encapsulation resin consists of a resin prepared by adding an acid anhydride type curing agent, an amine type curing accelerator, etc. to a bisphenol type epoxy resin, and is cured on a schedule that does not impair the transparency of the cured resin. Molded with the resin strength for practical use.

In recent years, these light emitting devices have been widely used outdoors because of their low power consumption.
A particularly important property for outdoor use is excellent adhesion between the resin and the metal lead. At the same time, it is necessary that the resin does not crack even if the resin is a large molded product due to the increase in size of the light emitting device. There is still nothing satisfying these characteristics, and its development has been desired.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances and is excellent in crack resistance, adhesiveness and transparency, good adhesion between resin and metal lead, and generation of cracks. The present invention aims to provide a highly reliable epoxy resin composition for encapsulating an optical semiconductor.

[0005]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventors have found that 1,8-diazabicyclo [5,4,0] undecene-7-salt as a curing accelerator. When,
The inventors have found that the above object can be achieved by using the aluminum organic compound in combination, and completed the present invention.

That is, the present invention relates to (A) epoxy resin,
(B) Phthalic anhydride, (C) 1,8-diazabicyclo
[5,4,0] Undecene-7 acid salt and (D) an aluminum organic compound as essential components, and 100 parts by weight of the phthalic anhydride of (B) above, to 1,8-diazabicyclo of (C) above
The total amount of [5,4,0] undecene-7 acid salt and (D) aluminum organic compound is 0.3 to 6 parts by weight, and their weight ratio [(C) / (D)] is 1/1 to 1 It is an epoxy resin composition for optical semiconductor encapsulation, characterized in that it is blended so as to be / 5.

The present invention will be described in detail below.

Examples of the (A) epoxy resin used in the present invention include transparent ones such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin and alicyclic epoxy resin. Can be used alone or in combination of two or more. In addition to these, phenol novolac type epoxy resin, heterocyclic epoxy resin, hydrogenated bisphenol A type epoxy resin, aliphatic epoxy resin, aromatic or alicyclic carboxylic acid are used within a range not deviating from the object of the present invention. An epoxy resin obtained by a reaction with epichlorohydrin, a spiro ring-containing epoxy resin and the like can be appropriately used in combination.

The (B) phthalic anhydride used in the present invention is used as a curing agent for the epoxy resin, and examples thereof include hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methylhexahydrophthalic anhydride and methyl. Examples thereof include colorless or pale yellow anhydrides such as tetrahydrophthalic anhydride, which may be used alone or in combination of two or more. The compounding ratio of phthalic anhydride is 0.5 to 1.8 per 1 equivalent of epoxy group of the above epoxy resin.
It is desirable to mix the same amount. If the amount is out of this range, the preferable reaction is not carried out, and the cured product is adversely affected, which is not preferable.

(C) 1,8-diazabicyclo used in the present invention
[5,4,0] Undecene-7 acid salt includes 1,8-diazabicyclo [5,4,0] undecene-7 formate, 1,8-diazabicyclo
[5,4,0] Undecene-7 2-ethylhexane salt, 1,8-diazabicyclo [5,4,0] undecene-7 phenol salt, 1,8-diazabicyclo [5,4,0] undecene-7 Oleate, 1,
Examples thereof include paratoluene sulfonate of 8-diazabicyclo [5,4,0] undecene-7. These may be used alone or in combination of two or more kinds.

Examples of the (D) aluminum organic compound used in the present invention include ethyl acetoacetate aluminum diisopropylate, aluminum tris (ethyl acetoacetate), aluminum tris (acetylacetonate), aluminum monoacetylacetonate bis (ethyl). Aluminum chelates such as acetoacetate) can be used, and these can be used alone or in combination of two or more kinds.

1,8-diazabicyclo [5,4,0] undecene-7
The compounding ratio of the curing accelerator composed of the acid salt and the aluminum organic compound is (C) 1,8-diazabicyclo [5,4,4,5] with respect to 100 parts by weight of the phthalic acid anhydride of the curing agent (B) described above.
0] It is desirable to add 0.3 to 6 parts by weight of the total amount of the undecene-7 acid salt and the (D) aluminum organic compound.
If the blending amount is less than 0.3 parts by weight, the initial curing rate of the resin is slow and not suitable for practical use, and if it exceeds 6 parts by weight, the cured resin is discolored, which is not preferable. The mixing ratio [(C) / (D)] of (C) 1,8-diazabicyclo [5,4,0] undecene-7 acid salt and (D) aluminum organic compound is a weight ratio.
It is desirable that it is 1/1 to 1/5. If the compounding ratio of the aluminum organic compound is less than 1/5, the initial curing speed of the resin will be slow, and if it exceeds 1/1, sufficient adhesiveness will not be obtained and transparency will deteriorate and cracks will easily occur. Not preferable.

In the epoxy resin composition for encapsulating an optical semiconductor of the present invention, the above-mentioned components are essential components, but other components may be added and blended as long as the object of the present invention is not impaired. Also, by mixing each of these components,
It can be easily manufactured by uniformly mixing.

[0014]

The epoxy resin composition for encapsulating an optical semiconductor of the present invention comprises an epoxy resin and a phthalic acid anhydride, and 1,8-diazabicyclo [5,4,0] undecene-7 acid salt and aluminum as a curing accelerator. By using an organic compound in combination and mixing them in a predetermined ratio, a composition having excellent adhesion, transparency and crack resistance was obtained.

[0015]

EXAMPLES The present invention will now be described with reference to examples, but the present invention is not limited to these examples. In the examples, "parts" means "parts by weight" unless otherwise specified.

Example 1 Liquid bisphenol A type epoxy resin Epicoat 828
(Okaka Shell Epoxy Co., Ltd., trade name) 100 parts of methylhexahydrophthalic anhydride 100 parts were added, and 1 part of 2-ethylhexane salt of 1,8-diazabicyclo [5,4,0] undecene-7 and Aluminum tris (acetylacetonate) 1
Parts were mixed and uniformly mixed to produce an epoxy resin composition for optical semiconductor encapsulation.

Examples 2 to 4 Epoxy resin compositions for optical semiconductor encapsulation were produced in the same manner as in Example 1 except that the proportion of the curing accelerator was changed.

Comparative Examples 1 to 5 An epoxy resin composition for encapsulating an optical semiconductor was produced in the same manner as in Example 1 except that the proportion of the curing accelerator was changed.

Using the epoxy resin compositions for optical semiconductor encapsulation obtained in Examples 1 to 4 and Comparative Examples 1 to 5, optical semiconductor elements were encapsulated to obtain molded products of 5φ and 10φ. Using this molded product, discoloration and adhesion to metal leads,
The presence or absence of cracking property was tested. The results are shown in Table 1, and the present invention was excellent in all cases, and the effects of the present invention could be confirmed.

[0020]

[Table 1]

[0021]

[Table 2] * 1: ◎ ... colorless and transparent, ○ ... slightly yellowing, △ ... slightly yellowing,
×: Yellowing, * 2: ○: Ink did not enter, Δ: Ink slightly entered, ×: Ink entered, * 3: ○: No cracks, Δ: Slightly cracked, ×
… Cracks, * 4: Characteristic test not possible due to insufficient curing.

[0022]

As is apparent from the above description and Table 2, the epoxy resin composition for encapsulating an optical semiconductor of the present invention is excellent in crack resistance, adhesiveness and transparency, and adheres between the resin and the metal lead. It has good properties and does not have cracks,
By using this composition, a highly reliable light emitting device can be manufactured.

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Claims (1)

Claims: (A) Epoxy resin, (B) phthalic anhydride, (C) 1,8-diazabicyclo [5,4,0] undecene-7 acid salt and (D) With an aluminum organic compound as an essential component, 1,8-diazabicyclo [5,4,0] of (C) above is added to 100 parts by weight of the phthalic anhydride of (B) above.
The total amount of the undecene-7 acid salt and the (D) aluminum organic compound is 0.3 to 6 parts by weight, and their weight ratio [(C)
/ (D)] in an amount of 1/1 to 1/5. An epoxy resin composition for optical semiconductor encapsulation.