JP3098663B2 - Thermosetting resin composition and production method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermosetting resin composition containing ultrafine silica particles, the cured product of which is excellent in both light transmittance and low stress.

[0002]

2. Description of the Related Art Conventionally, in the field of optoelectronics, thermosetting resin compositions have been used, for example, for optical adhesives, optical fiber materials, and sealing materials for optical semiconductor elements. However, when the thermosetting resin composition is used, an internal stress occurs in the cured body, and as a result,
There is a tendency that the function of the opt device is reduced.
Therefore, there is a strong demand for reducing the internal stress while maintaining the high transparency of the cured thermosetting resin composition. In order to achieve the above demand, the present inventors have already reduced the linear expansion coefficient of the cured resin composition by filling transparent resin with silica particles sufficiently shorter than the wavelength of light. And found that a transparent and low internal stress sealing resin can be obtained.
No. 33418).

[0003] Further, ultrafine particles sufficiently smaller than the wavelength of light have an extremely large surface area, so that they are in an unstable state only by being mixed and kneaded with a transparent resin, and secondary coagulation occurs.
The entire cured resin composition becomes cloudy and the transparency is reduced. The present inventors have also solved this problem, by mixing an organic solvent sol capable of dissolving the resin with the resin, the ultrafine particles are highly dispersed as primary particles in the resin, a highly transparent particle-filled resin composition It has been found that a cured product can be obtained and a patent application has been filed (Japanese Patent Application No. 4-116822).

[0004]

However, since an organic solvent capable of dissolving the resin is required to have a relatively high lipophilicity, particularly in the case of a thermosetting resin, silica when such a solvent is used is required. The stability of ultrafine particles, such as ultrafine particles, is very poor, and the aggregation of the particles proceeds during storage, and the transparency also decreases when mixed with a resin.

The present invention has been made in view of such circumstances, and a thermosetting resin which is excellent in both light transmittance and low stress of a cured product thereof and has excellent thermal properties and mechanical properties. For the purpose of providing the composition.

[0006]

Means for Solving the Problems The thermosetting resin composition of the present invention has a constitution containing the following components (A) to (D). (A) Thermosetting resin. (B) a curing agent. (C) a non-alcohol-based organic solvent capable of dissolving a thermosetting resin and a curing agent. (D) an alcohol sol of ultrafine silica particles.

That is, the present inventors have conducted a series of studies to obtain a thermosetting resin composition which gives a cured product having a small internal stress, excellent light transmittance, and excellent thermal properties and mechanical strength. Stacked. As a result, a resin component (a thermosetting resin and a curing agent) and a solvent capable of dissolving the resin component are added to the alcohol sol of the ultrafine silica, and the ultrafine silica is dispersed in the resin component. To achieve the intended purpose,
The invention has been reached.

Next, the present invention will be described in detail.

As the thermosetting resin (A) component, bisphenol-type epoxy resins and alicyclic epoxy resins are preferably used in order to have transparency. The epoxy resin usually has an epoxy equivalent of 100 to 100.
A material having a softening point of 120 ° C. or less is used. In some cases, other epoxy resins, urea resins, melamine resins, phenol resins, polyesters, alkyd resins,
Urethane resins and imide resins may be used.

Examples of the curing agent (B) include amines, phenolic resins, acid anhydrides, polyamides, polymercaptans, aldehydes, polyhydric alcohols, polyamines and amides. Among them, for example, an acid anhydride-based curing agent is preferably used in order for the resin component to have transparency. As the acid anhydride-based curing agent, those having a molecular weight of about 140 to 200 are preferably used. Specifically, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methylhexahydrophthalic anhydride and methyltetrahydrophthalic anhydride such as Colorless to pale yellow acid anhydrides may be mentioned.

The mixing ratio of the thermosetting resin composition and the curing agent is set in the range of 50 to 200 parts of the curing agent with respect to 100 parts by weight of the thermosetting resin (hereinafter abbreviated as "part"). Is preferred.

The non-alcohol-based solvent (C) that can dissolve the thermosetting resin and the curing agent is a solvent that dissolves the thermosetting resin and the curing agent and is compatible with the alcohol. Although not particularly limited, for example, ketone solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone, and non-polar solvents such as aromatic solvents such as toluene, xylene and benzene are used.

The alcohol sol (D) component of the ultrafine silica particles is synthesized, for example, by polymerizing silicic acid obtained by removing sodium ions from sodium silicate in water. The ultrafine silica thus synthesized is dispersed in water, and this may be replaced with alcohol. The concentration of the alcohol sol (D) component of the ultrafine silica particles is generally not more than 60% by weight, and usually 10 to 50%. The average particle diameter of the ultrafine silica constituting the alcohol sol (D) component of the ultrafine silica is 0.1
It is preferable to use ultrafine silica having a particle size of μm or less. Particularly preferably, the average particle size is 0.02 μm or less.

An alcohol capable of dispersing the above ultrafine silica particles
Alcohol solvent is a mono- to tri-valent alcohol, and
Its molecular weight is about 150 or less. For example,
Examples of the monovalent alcohol include methanol, ethanol, propanol and butanol, and the like.
Examples of ethylene glycol include ethylene glycol and butylene glycol. In addition, as a trivalent alcohol,
Glycerin and the like. These are used alone or in combination.

The mixing amount of the alcohol sol with respect to the resin component of the thermosetting resin as the component (A) and the curing agent as the component (B) is based on 100 parts of the resin component. The amount of ultrafine silica is preferably 1 to 400 parts. More preferably, the amount is 20 parts to 200 parts. That is, if it is 1 part or less, it is difficult to reduce the stress, and if it is 400 parts or more, the fluidity of the resin composition tends to decrease.

In order to improve the dispersibility of the ultrafine silica particles, a surfactant can be used. The surfactant is appropriately selected depending on the type of the alcohol. In consideration of the moisture resistance reliability of the optical semiconductor device, it is preferable to use a nonionic one. For example, a coupling agent is used. The coupling agent includes a silane coupling agent and a titanium coupling agent, and may be directly added to the ultrafine silica alcohol sol, or may be added to the ultrafine silica alcohol sol and the resin component and the resin. You may add after adding the solvent which can dissolve | dissolve a system component.

The amount of the alcohol in the alcohol sol (D) component of the solvent (C) component and the ultrafine particle silica is such that the solvent (C) component is added to 100 parts of the alcohol.
It is preferably set to 0 to 500 parts. That is, if the amount of the solvent (C) component is 10 parts or less, the solubility of the resin component tends to deteriorate, and it is difficult to uniformly mix the resin component and the ultrafine particles, and the amount of the solvent (C) component is 500 parts or more. In this case, the stability of the ultrafine silica particles in the solvent is reduced, and secondary aggregation is liable to be caused. Therefore, the silica particles tend not to be uniformly dispersed in the resin component. That is, in any case, there is a problem that the transparency tends to decrease when applied to an optical semiconductor device. In addition, the transparency of the cured product of the thermosetting resin composition includes the case of colored and transparent, and the light transmittance at a wavelength of 600 nm of the cured product at a sample thickness of 1 mm is 20 to
100%, preferably 80 to 100% (measured at 25 ° C. with a spectrophotometer).

If necessary, the curing catalyst used together with the thermosetting resin and the curing agent may include tertiary amines, imidazoles, imidazolines, diazabicycloalkenes, aliphatic amines and aromatic amines. Nitrogen atom-containing compounds such as amines, phosphonium salts such as triarylphosphine, monoalkyldiarylphosphine, tetraarylphosphoniumtetraallylborate, and phosphorus such as triarylphosphinetriarylborone complex Compound, aluminum triacetylacetona
And metal complexes such as When the thermosetting resin and the resin component of the curing agent include a curing catalyst, they are also regarded as resin components.

The compounding amount of the curing catalyst is as follows.
It is preferable to set the range of 0.001 to 5.0 parts with respect to 00 parts.

Further, conventionally known additives such as a dye, a denaturing agent, an anti-tarnishing agent, an antioxidant, a release agent and a reactive or non-reactive diluent can be added to the resin component.

The thermosetting resin composition according to the present invention comprises:
It is manufactured as follows, for example, using each of the above components. That is, first, the above (A) to (D)
The components and, if necessary, the curing catalyst and other additives are appropriately blended and uniformly mixed. In addition, you may heat and melt | dissolve a resin component in some cases. Thus, a thermosetting resin composition containing ultrafine silica particles is produced. The resin composition of the present invention is also prepared by removing the solvent from the resin composition in which the ultrafine silica particles are dispersed. The desolvation is performed by reducing the pressure at room temperature or the pressure under heating.

Usually, the resin composition after desolvation is liquid, but when the resin composition is solid, it is crushed by a known means and, if necessary, compressed by a series of steps. A resin composition can be manufactured.

The encapsulation of the optical semiconductor device using such a thermosetting resin composition is not particularly limited, and may be performed by a known molding method such as ordinary transfer molding and casting. Can be. As a result, an optical semiconductor device in which the optical semiconductor element is sealed with the sealing resin layer made of the cured thermosetting resin composition is obtained.

The optical semiconductor device thus obtained is
It has excellent transparency, extremely low internal stress, and excellent heat resistance and mechanical strength.

[0025]

As described above, according to the present invention, the alcohol sol of ultrafine silica is mixed with a resin component and a solvent capable of dissolving the resin component, and the ultrafine silica is dispersed in the resin component. Resin composition. Also, in actual use, usually, the solvent is removed, and a structure in which the ultrafine silica particles are uniformly dispersed in the resin-based component is obtained, so that the cured resin composition obtained therefrom has excellent light transmittance. Moreover, the internal stress is reduced. Therefore,
The deterioration of the optical semiconductor element is effectively suppressed, and the reliability is extremely increased. In addition, an optical semiconductor device having excellent heat resistance and mechanical strength can be obtained. In the above description, the case where the thermosetting resin composition of the present invention is applied to resin sealing of an optical semiconductor element has been mainly described. However, the present invention is not limited to this. It is also applied to a cured resin composition for sealing.

[0026]

The present invention will be described below with reference to examples. Example 1 An alcohol sol of silica in which 30 parts of silica particles having an average particle diameter of 0.015 μm were dispersed in 100 parts of methanol was added with
00 parts of methyl isobutyl ketone were added and then the silica dispersion was charged with a bispheno-epoxy equivalent of 180.
Then, 15 parts of A type epoxy resin, 15 parts of methylhexahydrophthalic anhydride and 0.5 part of antioxidant were added and dissolved, and the pressure was reduced to remove methanol and methyl isobutyl ketone. Next, 0.05 parts of 2-ethyl-4-methylimidazole was added and mixed as a curing catalyst to obtain an ultrafine silica-dispersed transparent resin composition (liquid). After casting the ultrafine particle silica-dispersed transparent resin composition thus obtained,
The composition was cured (cured) at 0 ° C. for 16 hours to prepare a cured product.

Examples 2 to 6 and Comparative Examples 2 to 4 Dissolve the particle diameter of ultrafine silica, the kind of solvent of ultrafine silica, and the resin component shown in Tables 1, 2 and 3 below. The intended ultrafine silica dispersed resin composition (liquid) was obtained in the same manner as in Example 1 except that the solvent and the amounts thereof were the same.

Example 7 An alcohol sol of silica in which 30 parts of silica particles having an average particle diameter of 0.015 μm were dispersed in 100 parts of methanol was added to
00 parts of methyl isobutyl ketone were added, and then the silica dispersion was charged with a bisphenol-epoxy equivalent of 640.
15 parts of epoxy resin A, 15 parts of tetrahydrophthalic anhydride and 0.5 part of an antioxidant were added and dissolved, and the pressure was reduced to remove methanol and methyl isobutyl ketone. Next, 0.05 parts of 2-ethyl-4-methylimidazole was added and mixed as a curing catalyst to obtain an ultrafine silica particle-dispersed transparent resin composition. The ultrafine particle silica-dispersed transparent resin composition (solid) thus obtained was pulverized, and the powder was tabletted into tablets, followed by transfer molding at 150 ° C. to produce a cured product.

Comparative Example 1 15 parts of a bisphenol A type epoxy resin having an epoxy equivalent of 180, 15 parts of methylhexahydrophthalic anhydride and 0.5 part of an antioxidant, and 2-ethyl-4- as a curing catalyst.
0.05 parts of methyl imidazole was added and mixed to obtain a transparent resin composition (liquid) containing no ultrafine silica particles. The resulting transparent resin composition containing no ultrafine silica particles was cast and cured at 120 ° C. for 16 hours to produce a cured product.

[0030]

[Table 1]

[Table 2]

[Table 3]

Next, the light transmittance, low stress, heat resistance and mechanical strength of the cured products obtained in the above Examples and Comparative Examples were evaluated. These results are shown in Tables 4 and 5. In addition, the said evaluation was performed by the following method. [Light transmittance] The light transmittance at a wavelength of 600 nm at a sample thickness of the cured product of 1 mm, which was measured at 25 ° C. using a spectrophotometer. [Low stress property] The low stress property was determined based on the luminance degradation due to stress. The luminance degradation was determined as follows. The light emitting element was resin-sealed using the epoxy resin composition after solvent removal obtained in Examples 1 to 7 and Comparative Examples 1 to 4. This optical semiconductor device (LED device having the following structure) has -30
At 20 ° C., a constant current of 20 mA was passed, and the output current value of the light receiving element after 5 seconds from the application of the current was determined as the luminance, and was used as the initial value. next,
Under the following conditions, that is, a constant current (20 mA) is applied to the optical semiconductor device 1000 hours after passing 20 mA of electricity at −30 ° C.
And the output current value of the light receiving element 5 seconds after current application was obtained as the luminance, and the luminance deterioration rate was calculated from the initial value. Package: pilot lamp having a diameter of 5 mm Evaluation element: GaAs having a size of 0.5 × 0.5 mm Evaluation condition: The luminance deterioration rate after 1000 hours of applying 20 mA at -30 ° C. was measured. Note that the luminance deterioration rate 0 to 20% is ○, 20 to 40% is Δ,
And 40% or more was evaluated as x. [Glass transition temperature] The glass transition temperature (Tg) was 2 ° C / ° C in a compression mode using a thermomechanical analyzer (TMA).
The measurement was performed at a rate of temperature increase by min. [Bending strength] Bending strength is determined by bending test evaluation, JIS K
It was measured by a three-point bending test based on 7055.

[0032]

[Table 4]

[Table 5]

From the results in Tables 4 and 5, Comparative Example 1 shows that
Since no ultrafine silica particles are filled, the light transmittance is excellent, but the stress inside the cured product is very large.
In Comparative Example 2, since the silica had a large particle diameter, light scattering occurred inside the cured product, and the light transmittance was poor. In Comparative Example 3, since the solvent capable of dissolving the resin component was small, the mixing of the resin and the ultrafine silica did not occur uniformly, and the light transmittance of the cured product was extremely poor. In Comparative Example 4, since toluene was used as the solvent for the ultrafine silica, the particles were subjected to a surface treatment to disperse the ultrafine silica. This acts as a plasticizing action and reduces heat resistance and mechanical strength. In contrast, it can be seen that all of the examples have high light transmittance, are excellent in low stress, and are excellent in heat resistance and mechanical strength.

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁷ identification code FI H01L 23/31 H01L 23/30 R 33/00 (58) Field surveyed (Int.Cl. ⁷ , DB name) C08L 1/00 -101/16 C08K 3/00-13/08 H01L 23/30 H01L 33/00

Claims (6)

(57) [Claims] 1. A thermosetting resin composition comprising the following components (A) to (D). (A) Thermosetting resin. (B) a curing agent. (C) a non-alcohol-based organic solvent capable of dissolving a thermosetting resin and a curing agent. (D) an alcohol sol of ultrafine silica particles. 2. A thermosetting resin composition containing the following components (A) to (E). (A) Thermosetting resin. (B) a curing agent. (C) a non-alcohol-based organic solvent capable of dissolving a thermosetting resin and a curing agent. (D) An alcohol sol of ultrafine silica having a particle size of 0.1 μm or less. (E) a curing catalyst. 3. A resin component 10 comprising a thermosetting resin (A) and a curing agent (B).
Component (D) is 1 to 10 parts by weight, based on the amount of ultrafine silica particles.
2. The thermosetting resin composition according to claim 1, which is blended in an amount of 400 parts by weight. 4. The thermosetting resin composition according to claim 1, wherein the solvent as the component (C) is contained in an amount of 10 to 500 parts by weight based on 100 parts by weight of the alcohol in the component (D). 5. An optical semiconductor device in which an optical semiconductor element is sealed using a thermosetting resin composition containing the following components (A) to (D). (A) Thermosetting resin. (B) a curing agent. (C) a non-alcohol-based organic solvent capable of dissolving a thermosetting resin and a curing agent. (D) an alcohol sol of ultrafine silica particles. 6. A thermosetting resin as the component (A), (B)
A semiconductor encapsulant comprising mixing a curing agent as a component, a non-alcohol organic solvent as a component (C), and an alcohol sol of ultrafine silica as a component (D), and removing the solvent. A method for producing a thermosetting resin composition.