JP2864842B2 - Epoxy resin composition for optical semiconductor encapsulation - Google Patents

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 an optical semiconductor which has high transparency, excellent heat resistance and can be molded in a short time.

[0002]

2. Description of the Related Art Generally, an acid anhydride-curable epoxy resin composition having excellent transparency is used for sealing a light emitting element and a light receiving element. For example, in an epoxy resin composition for transfer molding, as disclosed in JP-A-1-167359 and JP-A-2-222165, a curing agent such as tetrahydrophthalic anhydride or hexahydrophthalic anhydride is used as a curing agent. Basic anhydrides have been used.

[0003] However, although the general epoxy resin composition is at a usable level in terms of transparency, it takes 3 to 5 minutes (150 ° C) for transfer molding time, and there is a problem in molding cycle. Was. In addition, the heat resistance was not always satisfactory.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an epoxy resin composition mainly composed of an epoxy resin, a curing agent and a curing accelerator, comprising a curing agent containing a tetrabasic anhydride. It is characterized by its use. Further, the invention is characterized in that the tetrabasic acid anhydride is an alicyclic tetrabasic acid anhydride, and a mixed curing agent of the alicyclic dibasic acid anhydride is used.

[0005] The epoxy resin used in the present invention is not particularly limited as long as it is a conventionally known epoxy resin having little coloring. For example, bisphenol A type epoxy resin, hydrogenated bisphenol type epoxy resin, bisphenol F type epoxy resin, alicyclic epoxy resin, phenol novolak type epoxy resin, heterocyclic epoxy resin such as triglycidyl isocyanurate and the like, and the like. Alternatively, they are used together.

The curing agent used in the present invention includes, as an alicyclic dibasic anhydride, hexahydrophthalic anhydride or methylhexahydrophthalic anhydride, and as an alicyclic tetrabasic anhydride. Is, for example, 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride. The mixing ratio of the mixed curing agent composed of dibasic acid anhydride and tetrabasic acid anhydride is preferably such that the amount of tetrabasic acid anhydride is 50 wt% or less of the entire curing agent. If the amount of the tetrabasic acid anhydride exceeds 50% by weight of the entire curing agent, the rapid curing property and heat resistance hardly improve, but rather the transparency, pot life and economy become disadvantageous.

[0007] The equivalent ratio of the epoxy resin to the acid anhydride curing agent is preferably 0.8 to 1.1. If the equivalent ratio is less than 0.8, heat resistance and transparency are reduced. In addition, the equivalent ratio is 1.1
When the ratio exceeds the above range, the water absorption rate increases and the moisture resistance decreases.
Further, the curing accelerator used in the present invention is not particularly limited and may be a known one, and may include imidazoles, DBU and salts thereof,
Tertiary amines, ammonium salts, phosphonium salts and the like are exemplified, and the amount of addition may be 0.1 to 5 wt% based on the total amount of the epoxy resin and the curing agent.

Further, the epoxy resin composition of the present invention comprises:
In addition to the above components, conventionally known additives such as a release agent, an antioxidant, a coloring agent, an ultraviolet absorber, a visible light absorber, and a filler are used as necessary. Examples of the antioxidant include conventionally known compounds such as a phenol compound, a phosphite compound, and an organic sulfur compound.

[0009]

EXAMPLES The present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto. (1) Light transmittance Using a spectrophotometer (Hitachi U-2000 type), thickness 2
The light transmittance at 570 nm was measured for a sample of mm. (2) Glass transition temperature TMA (PTC-10A, manufactured by Rigaku Corp.) was used for a sample having a diameter of 4 mm and a length of 20 mm. (3) Fast Curability The transfer molding was performed under the following conditions, and the curability (mold release property) of the molded product and the cull (thickness: 5 mm) was evaluated as follows. << Transfer conditions >> Molding temperature --- 150 ° C. Molding time ---- 1 minute, 3 minutes Molding pressure --- 70 kgf / cm ² << Molded product and curable property >> A--Releasability from both molded product and cull Good B ---- Releasability of molded product, uncured

Examples 1 to 4, Comparative Example 1 According to the following Table 1, each raw material was blended, kneaded with a hot roll at 90 ° C. for 10 minutes, and then cooled and pulverized to obtain a desired fine powdery epoxy resin. A composition was obtained. Next, these resin compositions were molded under the above-described transfer conditions, and those that could be released were subjected to after-cure at 150 ° C. for 3 hours, and the light transmittance and glass transition temperature were measured. Further, regarding the light transmittance, an IR reflow furnace was used.
After performing the treatment for 2 seconds, the light transmittance was obtained again. Table 1 also shows these measurement results.

[0011]

[Table 1] Table 1 (weight ratio) ┌──────────────┬───────────────┬───┐ │ │ Example │ Comparative Example │ │ ├───┬───┬───┬───┼───┤ │ │ │ 1 │ 2 │ 3 │ 4 │ 1 │ ├──────┬─── 366 │ │ R366 ※ 1│ 80 │ 80 │ 80 │ 80 │ 80 │ │Epoxy resin├───── ──┼───┼───┼───┼───┼───┤ │ │ TEPIC-S ※ 2│ 20 │ 20 │ 20 │ 20 │ 20 │ ├──────┼─ │ │ * │ HH-A * 3 │ 33 │ 29 │ 24 │ 19 │ 39 │ │ Hardening agent -4 │ │ B-4400 ※ 4│ 4.5 │ 7.8 │ 13 │ 17 │ − │ ├── ────┴─ │ │B-4400 mixing amount (wt%) │ 12 │ 21 │ 35 │ 47 │ 0 │ ├── │ │Curing accelerator ※ 5│ 1 │ 1 │ 1 │ 1 │ 1 │ ┝━━━━━━┯━━━━━━━┿━━━┿━━━┿━━━┿━━━┿━━━┥ │ │ 150 ℃ / 1 minute │ A │ A │ A │ A │ C │ │ Fast curing ├───────┼───┼───┼───┼───┼───┤ │ │ 150 ℃ / 3min │ − │ − │ − │ − │ B │ ├──────┼───────┼───┼───┼───┼───┼───┤ │ │ After After Cure │ 88 │ 87 │ 87 │ 86 │ 88 │ │ Light transmittance (%) ├───────┼───┼───┼───┼───┼───┤ │ │ After IR reflow │ 86 │ 86 │ 87 │ 86 │ 68 │ │ Glass transition temperature (℃) │ 138 │ 144 │ 145 │ 147 │ 118 │ └──────────────┴───┴───┴───┴───┴───┘ * Curing agent equivalent = 0.9 * 1 : Made by Mitsui Petrochemical Industries * 2: Made by Nissan Chemical. * 3: Alicyclic dibasic acid anhydride manufactured by Nippon Rika Co., Ltd. * 4: Alicyclic tetrabasic acid anhydride manufactured by Dainippon Ink and Chemicals, Inc. * 5: 2E4MZ Imidazole manufactured by Shikoku Chemicals.

[0012]

As is clear from the results shown in Table 1, according to the present invention, it is possible to provide an epoxy resin composition for encapsulating an optical semiconductor having excellent light transmittance and heat resistance and having fast curing properties. It is possible.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-3-247619 (JP, A) JP-A-3-200858 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01L 23/28-23/30 C08G 59/42 C08K 5/09 H01L 33/00

Claims (3)

(57) [Claims] 1. An epoxy resin composition for encapsulating an optical semiconductor, characterized in that a curing agent containing a tetrabasic acid anhydride is used in an epoxy resin composition mainly comprising an epoxy resin, a curing agent and a curing accelerator. . 2. The epoxy resin composition for optical semiconductor encapsulation according to claim 1, wherein the tetrabasic acid anhydride is an alicyclic tetrabasic anhydride. 3. The epoxy resin composition for optical semiconductor encapsulation according to claim 1, wherein the curing agent is a mixed curing agent comprising an alicyclic tetrabasic acid anhydride and an alicyclic dibasic acid anhydride.