JP2001207019A - Epoxy resin composition for optical semiconductor device and optical semiconductor device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an epoxy resin composition for semiconductor devices capable of producing moldings rigid under heat and low in stress generation while sustaining light transmittance, and to provide an optical semiconductor device using the same. SOLUTION: The epoxy resin composition for optical semiconductor devices comprises ingredients (A), (B), (C), (D), and (E) and is used to encapsulate optical semiconductor devices, where (A) is an epoxy resin, (B) is a curing agent, (C) is a curing accelerator, (D) is a mold releasing agent, and (E) is a silicone compound with a refractive index of 1.45-1.60. The composition encapsulates an optical semiconductor element for the construction of an optical semiconductor device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting element such as an LED, a phototransistor, a photodiode and a CC.
The present invention relates to an epoxy resin composition for an optical semiconductor used for sealing a light receiving element such as D, a semiconductor element (an optical semiconductor element) such as an EPROM, and an optical semiconductor device using the composition.

[0002]

2. Description of the Related Art As a sealing material for an optical semiconductor device such as a light emitting device or a light receiving device, a resin using an epoxy resin composition in terms of excellent transparency, moisture resistance, adhesion, electrical insulation, heat resistance, and the like. Sealing is the mainstream. Above all, the method of resin sealing using an epoxy resin composition by transfer molding is excellent in workability and mass productivity. The epoxy resin composition used in the optical semiconductor field is required to have transparency (high light transmittance) in a used wavelength region.

On the other hand, when sealing a light-emitting element such as an LED or the like which is weak against a stress received from a sealing resin composition, a junction coat resin (hereinafter referred to as J) is required before sealing.
CR) and the like.

[0004]

As the demand for improvement in productivity has increased in recent years, the pre-coating process such as JCR is omitted by making the sealing resin composition itself have low stress. That is being considered.

[0005] In order to impart the above-mentioned low stress property to the epoxy resin composition, an epoxy resin having a large equivalent weight is used, or the equivalent ratio between the epoxy resin and the curing agent is regulated. Attempts have been made to reduce the Tg (glass transition temperature) of the material. However, when the epoxy resin composition is made to have a low Tg, the moldability deteriorates due to a decrease in the thermal rigidity of the sealing resin composition at the time of molding, and the humidity resistance reliability is deteriorated under severe conditions such as a PCT test. In some cases, it decreased. In addition, when the amount of the acid anhydride as a curing agent is increased to adjust the equivalent ratio between the epoxy resin and the curing agent, the electric conductivity of the molded article increases, and the reliability of the electric characteristics may be reduced.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an epoxy resin composition for an optical semiconductor for encapsulating an optical semiconductor element, the molded product having the basic performance. An object of the present invention is to provide an epoxy resin composition for optical semiconductors that has good heat stiffness and low stress while maintaining light transmittance. Another object of the present invention is to provide an optical semiconductor device which has good rigidity when heated and low stress while maintaining light transmittance.

[0007]

The epoxy resin composition for an optical semiconductor according to the present invention comprises the following (A), (B),
A composition comprising (C), (D) and (E) components,
This seals the optical semiconductor element. (A) component: epoxy resin, (B) component: curing agent, (C) component: curing accelerator, (D) component: release agent, (E) component: refractive index of 1.45 to 1.60. Silicone compounds.

As a result of the inventor's intensive studies to achieve the above object, the molded article using an epoxy resin composition containing a commonly used silicone compound has a high Tg but a low light transmittance. Although a tendency of inferiority is observed, a molded article using an epoxy resin composition containing a silicone compound having a refractive index of 1.45 to 1.60 maintains light transmittance of 90% or more, and has a high Tg. The present inventors have found that they have good thermal rigidity and low stress, and have completed the present invention.

The refractive index in the present invention is measured at 25 ° C. by the Abbe method. In addition, the light transmittance referred to in the present invention is such that when a molded product having a thickness of 1 mm is manufactured and the transmittance of the molded product is measured, the transmittance of light having a wavelength of 600 to 900 nm of 80% or more is measured. Having,
In particular, those having the transmittance of 90% or more are regarded as good.

[0010] The epoxy resin composition for an optical semiconductor according to claim 2 is the epoxy resin composition for an optical semiconductor according to claim 1, wherein the component (E) is the following (1), (2),
It is a silicone compound having at least one of the substituents represented by the structural formula (3).

[0011]

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[0012]

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[0013]

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(Wherein R ¹ R ² R ³ has 1 to 10 carbon atoms)
And m and n each represent an integer. The epoxy resin composition for an optical semiconductor according to claim 3 is the epoxy resin composition for an optical semiconductor according to claim 1 or 2, wherein the blending amount of the component (E) is 0.1% with respect to the total amount of the composition. It is characterized in that the content is from 0.01 to 5% by weight. By the above, it is possible to make the molded article have better low stress, moisture resistance and rigidity under heat.

According to a fourth aspect of the present invention, there is provided the epoxy resin composition for an optical semiconductor according to any one of the first to third aspects, wherein the component (D) is represented by the following general formula (4). It is characterized by being represented.

[0016]

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(In the formula, R ⁴ represents an unsaturated hydrocarbon group having 1 to 100 carbon atoms, and x and y represent integers.) The release agent has excellent releasability from a molding die. Because
When the encapsulation molding is performed using the epoxy resin composition for optical semiconductors, the molding operation is facilitated.

According to a fifth aspect of the present invention, there is provided the epoxy resin composition for an optical semiconductor according to any one of the first to fourth aspects, wherein the amount of the component (D) is less than the total amount of the composition. On the other hand, the content is 0.01 to 3% by weight. According to the above, the adhesion to the optical semiconductor element or the lead frame and the strength of the molded product can be improved.

According to a sixth aspect of the present invention, there is provided the epoxy resin composition for an optical semiconductor according to any one of the first to fifth aspects, wherein the component (B) is an acid anhydride. It is characterized by. Because of the above, it is suitable for an epoxy resin composition for optical semiconductors because it is less colored and has good electrical insulation.

The optical semiconductor device according to the seventh aspect is the first aspect of the invention.
An optical semiconductor element is encapsulated using the epoxy resin composition for an optical semiconductor according to any one of claims 6 to 6. The optical semiconductor device can maintain light transmittance, have good rigidity at the time of heat, and have low stress.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION The epoxy resin composition for an optical semiconductor of the present invention will be described. The above-mentioned epoxy resin composition for optical semiconductors comprises: an epoxy resin as a component (A);
A curing agent as a component, a curing accelerator as a component (C),
A composition comprising a release agent as a component (D) and a silicone compound as a component (E), which is used as a sealing material for sealing an optical semiconductor element. Examples of the optical semiconductor element include a light emitting element such as an LED, a phototransistor, a photodiode, and a CCD.
And a semiconductor device (optical semiconductor device) such as an EPROM.

The epoxy resin, which is the component (A) of the epoxy resin composition for optical semiconductors, contains 2 per molecule.
There is no particular limitation as long as it has at least two epoxy groups,
Those having relatively little coloring are preferred for use. Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, orthocresol novolak type epoxy resin, alicyclic epoxy resin, triglycidyl isocyanurate, aliphatic epoxy resin and the like. Is mentioned. Moreover, the thing which hydrogenated the aromatic part of the said epoxy resin can be illustrated. These epoxy resins are
Each can be used alone or in combination.

The curing agent as the component (B) of the epoxy resin composition for optical semiconductors is not particularly limited as long as it undergoes a curing reaction with the epoxy resin. preferable. As the above curing agent,
For example, novolak-type resin obtained by subjecting formaldehyde to a condensation reaction with acid anhydrides such as hexahydrophthalic anhydride, methylhexahydrophthalic anhydride or tetrahydrophthalic anhydride, or phenol, cresol, xylenol, resorcinol, etc. Examples include a mercaptan-based curing agent such as a mercaptan or a polysulfide resin. In addition, as the above-mentioned curing agent, an amine-based curing agent can also be used. However, since discoloration at the time of curing may become large, attention must be paid to a relatively small amount of addition. These curing agents can be used alone or in combination. Above all, acid anhydrides are preferred because they are less colored and have good electric insulation. The compounding amount of the above curing agent is an equivalent ratio to the epoxy resin, and the curing agent / epoxy resin = 0.5
It is preferably set to 1.5, more preferably 0.8 to 1.2 curing agent / epoxy resin.

The curing accelerator, which is the component (C) of the epoxy resin composition for optical semiconductors, is not particularly limited as long as it has an action of accelerating the reaction between the epoxy resin and the curing agent. Are preferred for use. Examples of the curing accelerator include organic phosphines such as triphenylphosphine and diphenylphosphine; cyclic amines such as 1,8-diazabicyclo (5,4,0) undecene-7 (DBU); triethanolamine And tertiary amines such as benzyldimethylamine; organic salts such as tetraphenylphosphonium / tetraphenylborate and tetraphenylphosphonium / bromide;
Imidazoles such as 1-benzyl-2-phenylimidazole; These curing accelerators can be used alone or in combination. Also,
The amount of the curing accelerator is 0.0% based on the total amount of the composition.
It is preferably 5 to 5% by weight. If the amount of the curing accelerator is less than 0.05% by weight, the effect of accelerating the reaction between the epoxy resin and the curing agent is not easily obtained, and if it exceeds 5% by weight, the gel time of the composition becomes too short. In addition, at the time of encapsulation molding, the molded product is liable to cause a decrease in moldability, such as generation of voids or unfilling.

The release agent as the component (D) of the epoxy resin composition for optical semiconductors is not particularly limited as long as it is compatible with other components. preferable. Examples of the release agent include saturated fatty acid monoamides such as lauric acid amide, unsaturated fatty acid monoamides such as oleic acid amide, substituted amides such as N-stearic acid amide, and n-methylol amides such as methylol stearic acid amide. , Unsaturated fatty acid bisamides such as methylene bisstearic acid amide, ethylene bisoleic acid amide,
Aromatic bisamides such as m-xylene bisstearic acid amide are exemplified. Further, as the above-mentioned releasing agent, those having excellent releasability from a molding die include those represented by the general formula (4). These release agents can be used alone or in combination. The amount of the release agent is preferably 0.01 to 3% by weight based on the total amount of the composition. If the amount of the release agent is less than 0.01% by weight, it is difficult to obtain the effect of mold release during molding, and if it exceeds 3% by weight, adhesion to an optical semiconductor element or a lead frame. This may lead to cracks in the molded product due to reduced properties and reduced strength of the molded product.

The silicone compound (E) of the epoxy resin composition for an optical semiconductor has a refractive index of 1.4.
5 to 1.60. The silicone compound,
It is compatible with the components (A), (B), (C), and (D) and expresses light transmittance to the molded article. When the above-mentioned silicone compound is contained, Tg is not reduced and low stress property can be imparted. If the refractive index is out of this range, the light transmittance of the molded article is reduced. It is.

Examples of the silicone compound include those having at least one of the substituents represented by the structural formulas (1), (2) and (3).

The amount of the silicone compound is as follows:
It is set based on the level of the low stress property and the rigidity when heated. For example, it is preferably 0.01 to 5% by weight based on the total amount of the composition. If the amount of the silicone compound is less than 0.01, the effect of low stress tends to be hardly obtained, and if it exceeds 5% by weight, the moisture resistance and the rigidity under heat of the molded article tend to be reduced. .

The epoxy resin composition for optical semiconductors may contain, as necessary, components other than the components (A), (B), (C), (D) and (E), a discoloration inhibitor and an antioxidant. , Dyes, inorganic fillers such as silica, silane coupling agents,
Modifiers, plasticizers, diluents and the like can be blended.

The epoxy resin composition for optical semiconductors is prepared by uniformly mixing the above-mentioned components using a mixer, a blender or the like, followed by heating and kneading using a kneader or a roll. The epoxy resin composition for an optical semiconductor is kneaded, if necessary, cooled and solidified, pulverized to a powdery form, or further tableted to be used.

The semiconductor device of the present invention is obtained by encapsulating an optical semiconductor element using the above-mentioned epoxy resin composition for an optical semiconductor. In manufacturing the semiconductor device, the semiconductor element is encapsulated by transfer molding with a solid (tablet-like) epoxy resin composition for optical semiconductors, and then the epoxy resin composition for optical semiconductors is cured. To form a sealing material. In addition, when the properties of the epoxy resin composition for optical semiconductors are liquid at room temperature, casting, potting, printing, and other methods can be employed to cast and cure.

[0032]

EXAMPLES In order to confirm the effects of the present invention, epoxy resin compositions for optical semiconductors were prepared, molded articles for evaluation were prepared using them, and evaluations were made. The following materials were used in Examples and Comparative Examples.

(Constituent Material) As the epoxy resin as the component (A), the epoxy resin (I) has an epoxy equivalent of 925.
Bisphenol A type epoxy resin (manufactured by Yuka Shell Epoxy Co., Ltd., Epicoat 1004), epoxy resin (II) having an epoxy equivalent of 4000 bisphenol A type epoxy resin (manufactured by Yuka Shell Epoxy Co., Ltd.,
(Epicoat 1100, trade name) was used.

An acid anhydride (THPA, equivalent: 152, manufactured by Shin Nippon Rika Co., Ltd.) was used as a curing agent as the component (B), and 1-benzyl-2-phenyl was used as a curing accelerator as the component (C). Imidazole was used.

The release agent as the component (D) comprises the release agent (I)
Using erucic acid amide (manufactured by NOF Corporation, E-10)
The release agent (II) is represented by the above general formula (4), and R ⁴ = 5
Those having 0, x = 3, and y = 25 were used.

As the silicone compound (E),
A silicone compound having a substituent represented by the structural formula (1) and having a refractive index of 1.45 (X-22-4741 manufactured by Shin-Etsu Chemical Co., Ltd.) represented by the structural formula (2). A silicone compound having a substituent having a refractive index of 1.46 (KF-354, manufactured by Shin-Etsu Chemical Co., Ltd.) having a refractive index of 1.46 having a substituent represented by the structural formula (3) above.
Silicone compound (I) (KF-54, manufactured by Shin-Etsu Chemical Co., Ltd.) and silicone compound (II) (1.5) having a substituent represented by the structural formula (3) and having a refractive index of 1.58. KF-5) manufactured by Shin-Etsu Chemical Co., Ltd. was used.

As a silicone compound for comparison,
Silicone compound (I) having a methyl group as a substituent and having a refractive index of 1.375 (manufactured by Shin-Etsu Chemical Co., Ltd., KF-9)
6L-0.65) and a silicone compound (II) having a substituent represented by the above structural formula (2) but having a refractive index of 1.42 (KF-601 manufactured by Shin-Etsu Chemical Co., Ltd.)
5) was used.

As other materials, an antioxidant (AO-50, manufactured by Asahi Denka) was used.

(Examples 1 to 6, Comparative Examples 1 to 3) The above materials were blended at the blending ratios (parts by weight) shown in Table 1 and uniformly mixed by a blender for 30 minutes. This mixture was kneaded and melted in a kneader heated to 80 ° C., extruded, cooled, and then pulverized with a pulverizer to obtain a tablet-like epoxy resin composition for sealing having a particle diameter of about 5 mm.

[0040]

[Table 1]

(Evaluation) A molded article for evaluation was prepared, and its light transmittance, Tg, rigidity at heat, low stress property, and moisture resistance reliability were evaluated.

The light transmittance was measured as follows.
First, transfer molding was performed using the epoxy resin compositions for optical semiconductors of Examples and Comparative Examples to a thickness of 1 mm.
A molded article for evaluation was prepared. The molded article for evaluation was formed by molding under the conditions of a mold temperature of 150 ° C., an injection time of 35 seconds, and a pressure holding time of 150 seconds, and further after-curing at 150 ° C. for 2 hours. The molded article for evaluation obtained in this manner was used with a spectrophotometer U-manufactured by Hitachi, Ltd.
The light transmittance was measured by changing the measurement wavelength from 900 nm to 600 nm using 3400. Table 2 shows the maximum value and the minimum value between the wavelengths.

As for Tg, transfer molding was carried out using the epoxy resin compositions for optical semiconductors of Examples and Comparative Examples to produce cylindrical evaluation molded articles having a thickness of 20 mm and a diameter of 5 mm. The molded article for evaluation was produced by molding under the conditions of a mold temperature of 150 ° C., an injection time of 35 seconds, and a pressurizing time of 150 seconds, and after-curing at 150 ° C. for 2 hours. With respect to the molded article for evaluation obtained in this way, T
The measurement was carried out using MA at a heating rate of 5 ° C./min.

The rigidity under heat was determined by transfer molding using the epoxy resin compositions for optical semiconductors of Examples and Comparative Examples to produce disk-shaped molded articles for evaluation having a thickness of 3 mm and a diameter of 50 mm. The molded product for evaluation has a mold temperature of 150 ° C.
After molding under the conditions of an injection time of 35 seconds and a pressurization time of 150 seconds, the surface hardness was measured using a Shore A hardness meter immediately after taking out. Table 2 shows the average values measured five times.

The low stress resistance and the moisture resistance reliability were measured as follows. First, using the epoxy resin compositions for optical semiconductors of Examples and Comparative Examples, a circuit width of 10 μm and a thickness of 1 were used.
A 16 DIP package (42 alloy / silver-plated lead frame) on which a TEG having a μm comb-shaped aluminum pattern formed was mounted. This 16DIP package was produced by transfer molding under the conditions of a mold temperature of 150 ° C., an injection time of 35 seconds, and a pressurizing time of 150 seconds, followed by after-curing at 150 ° C. for 2 hours.

Next, for the low stress property, ten samples were taken out of each of the prepared 16 DIP packages, and the initial resistance value was measured.
One cycle was performed at a temperature of 20 ° C. and a normal temperature of 5 minutes, and the treatment was performed for 200 cycles. Then, after this processing, the resistance value is measured,
Those whose resistance value changed by 10% or more were regarded as defective. Out of the ten pieces, 不良 indicates that there was no defect, and 発 生 indicates that one occurred, and × indicates that two or more pieces occurred.

Further, the moisture resistance reliability was as high as that of the prepared 16DIP.
Each of 10 packages was extracted and the temperature was 121 ° C.
After processing with a PCT tester under the conditions of 100% RH, 2 atm and 50 hours, the PCT was taken out and the presence or absence of disconnection was measured. 1
Of the 0 pieces, 0 indicates no disconnection failure, 1 indicates the occurrence of disconnection, and 2 indicates two or more.

The results are as shown in Table 2.
(A), (B), (C), (D), those using the epoxy resin composition for optical semiconductors of Examples 1 to 6 in which the components (E) are blended, all have a rigidity of 80 when heated. Tg
Was not lowered to 118 ° C. or more, and the low stress property and the moisture resistance reliability were also good. On the other hand, Comparative Example 1 in which low Tg was improved by lowering the Tg to 74 ° C., which had been conventionally attempted, had poor rigidity at heat and poor moisture resistance reliability. Further, the refractive index of the silicone compound is 1.
In Comparative Examples 2 and 3 using less than 45, the light transmittance was also 60% or less.

[0049]

[Table 2]

[0050]

The epoxy resin composition for an optical semiconductor according to any one of the first to third aspects of the present invention has a molded article in which an optical semiconductor element is encapsulated using the epoxy resin composition, while maintaining light transmittance and having good rigidity when heated. And can have a low stress property.

Further, in the epoxy resin composition for an optical semiconductor according to the fourth aspect, since the mold release agent has excellent releasability from a molding die, the epoxy resin composition for an optical semiconductor is preferably used. When performing sealing molding, the molding operation is facilitated.

Furthermore, in the epoxy resin composition for an optical semiconductor according to the fifth aspect, the compounding amount of the component D) is 0.01 to 3% by weight based on the total amount of the composition. The adhesion to the frame and the strength of the molded product can be improved.

Furthermore, the epoxy resin composition for an optical semiconductor according to the present invention has a low coloration and good electric insulation since the component (B) is an acid anhydride. Suitable for epoxy resin compositions for optical semiconductors.

In the optical semiconductor device according to the present invention, the optical transparency is maintained, the rigidity at the time of heat is good, and the stress can be reduced.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 83/07 C08L 83/07 83/12 83/12 H01L 23/29 H01L 23/30 F 23 / 31F Terms (reference) 4J002 CC052 CD011 CD021 CD051 CD061 CD111 CD141 CN022 EL136 EN077 EN107 EP018 EP028 EU117 EU137 EW017 EW177 EX039 EX069 FD142 FD146 FD157 FD168 GQ05 4J036 AA01 AD08 AD20 AF06 DA01 DA02 DB17 DC41 DC12 FB02 DD07 EB02 EB04 EB06 EB08 EB09 EB13 EB18 EB19 EC04 EC07 EC09 EC11 EC20 GA01

Claims (7)

[Claims] 1. The following (A), (B), (C), (D),
An epoxy resin composition for an optical semiconductor, which encapsulates an optical semiconductor element, which is a composition containing the component (E). (A) component: epoxy resin, (B) component: curing agent, (C) component: curing accelerator, (D) component: release agent, (E) component: refractive index of 1.45 to 1.60. Silicone compounds. 2. The method according to claim 1, wherein the component (E) is as follows:
The epoxy resin composition for an optical semiconductor according to claim 1, wherein the epoxy resin composition is a silicone compound having at least one of the substituents represented by the structural formula (3). Embedded image Embedded image Embedded image (In the formula, R ¹ R ² R ³ represents an unsaturated hydrocarbon group having 1 to 10 carbon atoms, and m and n represent integers.) 3. The epoxy resin composition for an optical semiconductor according to claim 1, wherein the amount of the component (E) is 0.01 to 5% by weight based on the total amount of the composition. . 4. The epoxy resin composition for an optical semiconductor according to claim 1, wherein the component (D) is represented by the following general formula (4). Embedded image (In the formula, R ⁴ represents an unsaturated hydrocarbon group having 1 to 100 carbon atoms, and x and y represent integers.) 5. The epoxy resin for an optical semiconductor according to claim 1, wherein the amount of the component (D) is 0.01 to 3% by weight based on the total amount of the composition. Composition. 6. The epoxy resin composition for an optical semiconductor according to claim 1, wherein the component (B) is an acid anhydride. 7. An optical semiconductor device comprising an optical semiconductor element encapsulated with the epoxy resin composition for an optical semiconductor according to claim 1.