JP2006193566A - Method for producing epoxy resin composition for optical semi-conductor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing an epoxy resin composition which has both transparency and mold releasability, has excellent adhesiveness, and is used for optical semi-conductors, and to provide a semi-conductor using the same. <P>SOLUTION: This method for producing the epoxy resin composition which is used for optical semi-conductors and contains an epoxy resin (A), an acid anhydride curing agent (B), an alcohol (C) having two hydroxyl groups in the molecule, a mold release agent (D) having a specific structure, and a dispersing agent (E) as main components is characterized by having a process for preliminarily melt-mixing the components (A) to (E) and a process for mixing and kneading the melt-mixed main components with components except the main components. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for producing an epoxy resin composition for optical semiconductors.

As sealing materials for optical semiconductors such as light-emitting elements and light-receiving elements, resin sealing using an epoxy resin composition having excellent transparency, moisture resistance and heat resistance has become the mainstream, among which epoxy resin compositions are used. The method of resin sealing by transfer molding is excellent in terms of workability and mass productivity.
In general, when an epoxy resin composition is molded in transfer molding, a method of adding a release agent to the epoxy resin composition is taken in order to improve the mold release property of the molded product. In the case where the above optical semiconductor element is encapsulated by transfer molding, the addition of a release agent that improves the releasability without impairing the transparency of the epoxy resin composition has been proposed. A method of using a compound to achieve both transparency and releasability (see, for example, Patent Document 1 and Patent Document 2), using a compound having a specific structure, and releasing from an epoxy resin, a curing agent, and a curing accelerator As a compatibilizing agent for facilitating the compatibility of the agent, there is a method of blending a mercaptosilane coupling agent to achieve both transparency and releasability (for example, see Patent Document 3).
Furthermore, the demand for the package mounting system from the pin insertion type to the surface mounting type is rapidly increasing. The surface mount type does not heat only the lead part as in the pin insertion type, but rather heats the entire package to melt the solder applied in advance to the lead part and mount it, compared to the pin insertion type. Higher heat resistance is required. In order to cope with this, it is necessary to further improve the adhesion between the lead frame, the optical semiconductor element and other components inside the package and the epoxy resin composition, which is one of the factors that reduce the adhesion. It is necessary to suppress the addition amount of the agent and to impart good releasability. However, it is difficult to satisfy all of adhesion, releasability and transparency by the conventional method described above, and further technical improvements are required.
Japanese Patent No. 2781279 (pages 1 to 18) JP-A-11-343395 (pages 2-6) Japanese Patent No. 3392012 (pages 1-6)

  The present invention has been made to solve the above-mentioned problems, and the object of the present invention is to provide a method for producing an epoxy resin composition for optical semiconductors excellent in transparency and releasability. is there.

The present invention
[1] The main components are an epoxy resin (A), an acid anhydride curing agent (B), an alcohol (C) having two hydroxyl groups in one molecule, a release agent (D), and a dispersant (E). A method for producing an epoxy resin composition for an optical semiconductor, comprising the steps of previously melt-mixing the components (A) to (E) and mixing and kneading the melt-mixed main component and components other than the main component. A method for producing an epoxy resin composition for optical semiconductors, comprising:
[2] The method for producing an epoxy resin composition for optical semiconductors according to item [1], wherein the release agent (D) contains a compound represented by the general formula (1),

（但し、式中のＲ１は炭素数２５〜３５の直鎖アルキル基。ｎ１は２以上、１０以下。）

(However, R1 in the formula is a linear alkyl group having 25 to 35 carbon atoms. N1 is 2 or more and 10 or less.)

[3] The method for producing an epoxy resin composition for an optical semiconductor according to [1] or [2], wherein the dispersant contains a compound represented by the general formula (2),

（但し、式中のＲ２は炭素数１０〜１４の直鎖アルキル基。ｎ２は８以上、１２以下。）

(However, R2 in the formula is a linear alkyl group having 10 to 14 carbon atoms. N2 is 8 or more and 12 or less.)

[4] The content of the alcohol (C) having two hydroxyl groups in one molecule is 0.5% by weight or more and 1.5% by weight or less of the total amount of the components (A) to (E). A method for producing an epoxy resin composition for optical semiconductors according to items [1] to [3],
[5] First [1] to [4], wherein the content of the release agent (D) is 1.2 wt% or more and 2.0 wt% or less of the total amount of the components (A) to (E). The manufacturing method of the epoxy resin composition for optical semiconductors of claim | items,
[6] Items [1] to [5], wherein the content of the dispersant (E) is 0.1 wt% or more and 0.8 wt% or less of the total amount of the components (A) to (E). The manufacturing method of the epoxy resin composition for optical semiconductors of description,
[7] An optical semiconductor device encapsulated with the epoxy resin composition for optical semiconductors produced by the manufacturing method according to any one of items [1] to [6],
It is.

  According to the present invention, both transparency and releasability can be achieved, and adhesion can be imparted, making it suitable for responding to rapidly mounting surface mount package mounting methods. It is.

  The present invention includes a step of melt-mixing a main component in advance with an epoxy resin, an acid anhydride curing agent, an alcohol having two hydroxyl groups in a molecule, a release agent having a specific structure, and a dispersant as main components. The process of mixing and kneading the main component and the component other than the main component can achieve both transparency and releasability, and good mold release with a smaller amount of release agent. With a production method that can produce an epoxy resin composition for optical semiconductors that provides excellent adhesion to members inside the package such as lead frames and optical semiconductor elements required for surface mounting methods. is there.

Hereinafter, the present invention will be described in detail.
The epoxy resin (A) used in the present invention is a monomer, oligomer or polymer in general, and its molecular weight and molecular structure are not particularly limited as long as it has two or more epoxy groups in one molecule. Bisphenol type epoxy resin such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, biphenyl type epoxy resin, hydrogenated bisphenol A type epoxy resin, phenol novolak type epoxy resin, orthocresol novolak type epoxy Examples thereof include resins and triglycidyl isocyanurate. These may be used alone or in combination. From the viewpoint of transparency, it is preferable to use a bisphenol type epoxy resin or triglycidyl isocyanurate with little coloring.

Examples of the acid anhydride curing agent (B) used in the present invention include monomers, oligomers and polymers in general, and the molecular weight and molecular structure thereof are not particularly limited. For example, phthalic anhydride, maleic anhydride, trimellitic anhydride Acid, pyromellitic anhydride, hexahydrophthalic anhydride, 3-methyl-hexahydrophthalic anhydride, 4-methyl-hexahydrophthalic anhydride, or 3-methyl-hexahydrophthalic anhydride and 4-methyl-hexahydrophthalic anhydride Examples thereof include a mixture, tetrahydrophthalic anhydride, nadic anhydride, and methyl nadic anhydride. These may be used alone or in combination.
It is preferable to set the epoxy equivalent of all epoxy resins to 0.5 to 1.5 with respect to the acid anhydride equivalent of the acid anhydride curing agent used in the present invention, and more preferably 0.8 to 1.2. If it is out of the above range, the moisture resistance, curability and the like may be lowered, which is not preferable.

  In the present invention, an alcohol (C) having two hydroxyl groups in one molecule is used for the purpose of causing a slow reaction between the epoxy resin (A) and the acid anhydride curing agent (B), and B having a stable molecular weight distribution. It becomes possible to obtain the resin composition in a stage state in a short time. For example, ethylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol and the like can be mentioned. These may be used alone or in combination. From the viewpoint of workability, 1,5-pentanediol is preferred.

  In the present invention, for the purpose of imparting transparency and releasability, a compound represented by the general formula (1) is used as a release agent, and a compound represented by the general formula (2) is used as a dispersant. These compounds are ethoxylated linear alcohols, and the balance between the number of carbon atoms in the alkyl moiety and the weight ratio of ethyl ether in the entire compound is very important for transparency and releasability. Transparency is excellent when the weight ratio of the ethyl ether portion is large, but sufficient releasability cannot be obtained. Conversely, when the weight ratio of the alkyl portion is large, the releasability is excellent, but sufficient transparency is obtained. I can't. For example, when R1 has 30 carbon atoms in the compound represented by the general formula (1), this compound is used alone (meaning that the dispersant represented by the general formula (2) is not blended). It is essential that n1 is 2 or more and 10 or less. When n1 is less than the lower limit, transparency is easily impaired, and when n1 exceeds the upper limit, release properties are hardly exhibited. However, in order to obtain sufficient releasability with the compound represented by the general formula (1) alone, it is necessary to increase the amount of blending, and not only the transparency but also the members inside the package such as lead frames and optical semiconductor elements The adhesiveness of the surface is lowered, and it becomes difficult to cope with the surface mounting type. However, when a compound represented by the general formula (2) in which the weight ratio of the ethyl ether portion is larger than that of the general formula (1) is used as a dispersant, the release property can be expressed with a smaller blending amount. A decrease in adhesion can be suppressed. This is presumed that the compound of the compound represented by the general formula (1) dispersed in the matrix resin is further refined by blending the compound represented by the general formula (2). Yes. For example, when R2 has 12 carbon atoms in the compound represented by the general formula (2), it is essential that n2 is 8 or more and 12 or less. When n2 is less than the lower limit value or exceeds the upper limit value, the effect as a dispersant is small, and in terms of releasability, transparency and adhesion compared to the case where the compound represented by the general formula (1) is used alone. The effect is almost unchanged.

  In the resin composition of the present invention, the components (A) to (E) may be previously melt-mixed, and examples of the melt-mixing method include a reaction kettle and a heating kneader. In the resin composition of the present invention, components (A) to (E) are melted and mixed in a reaction kettle, etc., and after obtaining a B-stage resin composition, other components are added and mixed using a mixer or the like. , Kneading using a heating kneader, heating roll, extruder, etc., followed by cooling and pulverization. If the components (A) to (E) are not melted and mixed in advance, the transparency that satisfies the optical device function cannot be obtained, and the continuous moldability is deteriorated and the production of the optical semiconductor device is lowered.

As a component used in the production method of the present invention, an antioxidant such as a phenol compound, an amine compound, a phosphite compound, an organic sulfur compound, etc., if necessary, in addition to the components (A) to (E), Ultraviolet absorbers such as benzophenone compounds, benzotriazole compounds, benzoate compounds, and cyanoacrylate compounds, and inorganic fillers such as glass powder, silica powder, and alumina powder can be appropriately blended.
The semiconductor device of the present invention is formed by sealing an optical semiconductor element with an epoxy resin composition containing the one manufactured according to the present invention. When this epoxy resin composition is solid at room temperature, it is in the form of a tablet. The molded product can be cast and cured by transfer molding, or in the case of a liquid, using a casting method or the like.

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. The blending ratio is parts by weight.
Experimental example 1
Bisphenol type epoxy resin, triglycidyl isocyanurate, mold release agent 1 and dispersant 1 were charged into a 30 L reactor and heated until all were melted. Thereafter, the temperature of the inner wall of the reaction kettle was stabilized at 95 ° C., 4-methylhexahydrophthalic anhydride and 1,5-pentanediol were added, and the reaction was gently continued until an appropriate molecular weight distribution was obtained. When an appropriate molecular weight distribution was obtained, the resin was immediately removed from the reaction kettle, cooled and solidified, and then pulverized. 2-Methylimidazole, 2,6-ditertiarybutyl-4-methylphenol, 4-dodecyloxy-2-hydroxybenzophenone and glass powder are added to the pulverized product and mixed at room temperature using a mixer, and then the surface temperature is increased. Were kneaded using two rolls at 80 ° C. and 15 ° C., cooled and pulverized to obtain an epoxy resin composition.

Bisphenol-type epoxy resin (Mitsui Chemicals, R364PD, softening point 98 ° C., epoxy equivalent 980) 39.42 parts by weight triglycidyl isocyanurate (Nissan Chemical Co., Ltd., TEPIC-S, melting point 100 ° C., epoxy equivalent) 101) 16.90 parts by weight 4-methylhexahydrophthalic anhydride (manufactured by Shin Nippon Rika Co., Ltd., MH-700, acid anhydride equivalent 164) 34.03 parts by weight 1,5-pentanediol 0.85 parts by weight Release agent 1 1.40 parts by weight (In general formula (1), R1 is a linear alkyl group having 30 carbon atoms. N1 is 2.5.)
Dispersant 1 0.50 part by weight (In the general formula (2), R2 is a linear alkyl group having 12 carbon atoms. N2 is 10.)
2-methylimidazole 1.10 parts by weight 2,6-ditertiarybutyl-4-methylphenol 0.40 parts by weight 4-dodecyloxy-2-hydroxybenzophenone 0.40 parts by weight Glass powder (median diameter 25 μm, refractive index 1. 570) 5.00 parts by weight

Evaluation method Spiral flow: Using a mold for spiral flow measurement according to EMMI-1-66, measurement was performed at a mold temperature of 175 ° C., an injection pressure of 6.9 MPa, and a curing time of 2 minutes. The unit is cm.
Transparency: Using a transfer molding machine, a test piece having a mold temperature of 160 ° C., an injection pressure of 9.8 MPa, a curing time of 2 minutes, 15 × 35 mm and a thickness of 1 mm was molded, and post-cured at 160 ° C. for 2 hours. The light transmittance at a wavelength of 500 nm was measured for the obtained test piece using a spectrophotometer U-330 type (60φ, equipped with an integrating sphere with an aperture ratio of 7.8%) manufactured by Hitachi. Units%.
Continuous moldability: Using a transfer molding machine, 10 shots of mold cleaning resin (Sumitomo Bakelite Co., Ltd., EMEC-3), 3 mold release recovery resins (Sumitomo Bakelite Co., Ltd., EMEC-100) After shot molding, SOT (3-pin, 2.9 x 2 mm, thickness 1.1 mm, copper lead frame, semiconductor element is not mounted under molding conditions of mold temperature 160 ° C, injection pressure 9.8 MPa, curing time 2 minutes ) Was continuously molded to evaluate whether the cured resin was released from the mold. Count the number of shots until the package, runner, and cal stick to the mold, ◎ if 400 shots or more, ◎ 200 shots or more, less than 400 shots ◯, 100 shots or more, less than 200 shots △, The case of less than 100 shots was rated as x.
Adhesion: Using a transfer molding machine, a mold temperature of 160 ° C., an injection pressure of 9.8 MPa, a curing time of 2 minutes is 9 × 9 mm, and a thickness of 0.3 mm is 2 × on a silver-plated copper frame and an unplated copper frame. A cured resin having a thickness of 2 mm and a height of 3 mm was molded and post-cured at 160 ° C. for 2 hours. The obtained 8 silver-plated copper frame test pieces and 8 non-plated copper frame test pieces were cooled to room temperature, and the shear adhesion strength was measured at a tool moving speed of 2 mm / sec using 2400A made by DAGE. It was measured. The unit is N.
Experimental Examples 2 to 17
In accordance with the formulations shown in Tables 1 and 2, Experimental Examples 2 to 16 obtained an epoxy resin composition in the same manner as Experimental Example 1, and Experimental Example 16 was an epoxy resin composition without melt-mixing a release agent and a dispersant in advance. I got a thing. In Experimental Example 17, the components (A) to (E) and other components were prepared only by melt mixing, and an epoxy resin composition was obtained without performing subsequent mixing and kneading. Each level was evaluated in the same manner as in Experimental Example 1. These evaluation results are shown in Tables 1 and 2.
The release agents and dispersants used in other than Experimental Example 1 are shown below.
Release agent 2 (In general formula (1), R1 is a linear alkyl group having 30 carbon atoms. N1 is 10.)
Release agent 3 (In general formula (1), R1 is a linear alkyl group having 30 carbon atoms. N1 is 40.)
Release agent 4 (In general formula (1), R1 is a linear alkyl group having 40 carbon atoms. N1 is 13.)
Dispersant 2 (In General Formula (2), R2 is a linear alkyl group having 12 carbon atoms. N2 is 16.)

The production method of the present invention can achieve both transparency and releasability, which could not be obtained by conventional techniques, and expresses good releasability with a smaller amount of release agent. Since excellent adhesion to members inside the package such as a lead frame and an optical semiconductor element can be imparted, it can be suitably used as a surface-mount type resin-encapsulated semiconductor device.

Claims (7)

  For optical semiconductors mainly composed of epoxy resin (A), acid anhydride curing agent (B), alcohol (C) having two hydroxyl groups in one molecule, mold release agent (D), and dispersant (E) A method for producing an epoxy resin composition, comprising: a step of melt-mixing the components (A) to (E) in advance, and a step of mixing and kneading the melt-mixed main component and components other than the main component. A method for producing an epoxy resin composition for optical semiconductors. The manufacturing method of the epoxy resin composition for optical semiconductors of Claim 1 in which the said mold release agent (D) contains the compound shown by General formula (1).

(However, R1 in the formula is a linear alkyl group having 25 to 35 carbon atoms. N1 is 2 or more and 10 or less.) The manufacturing method of the epoxy resin composition for optical semiconductors of Claim 1 or 2 in which the said dispersing agent contains the compound shown by General formula (2).

(However, R2 in the formula is a linear alkyl group having 10 to 14 carbon atoms. N2 is 8 or more and 12 or less.)   The content of the alcohol (C) having two hydroxyl groups in one molecule is 0.5 wt% or more and 1.5 wt% or less of the total amount of the components (A) to (E). The manufacturing method of the epoxy resin composition for optical semiconductors of ~ 3.   5. The epoxy for optical semiconductors according to claim 1, wherein the content of the release agent (D) is 1.2 wt% or more and 2.0 wt% or less of the total amount of the components (A) to (E). A method for producing a resin composition.   The content of the dispersant (E) is 0.1 wt% or more and 0.8 wt% or less of the total amount of the components (A) to (E). A method for producing the composition. The optical semiconductor device sealed using the epoxy resin composition for optical semiconductors produced with the manufacturing method of any one of Claims 1-6.