Epoxy resin composition for optical semiconductor element sealing and optical semiconductor apparatus using the same

The present invention relates to an epoxy resin composition for encapsulating an optical semiconductor device, which is excellent in both light transmittance and low stress property, and an optical semiconductor device resin-sealed using the epoxy resin composition.

As a sealing resin composition used for sealing an optical semiconductor element such as a light emitting diode (LED), the cured product is required to have transparency, and therefore, a bisphenol A type epoxy resin is generally used. An epoxy resin composition obtained by using an epoxy resin such as an alicyclic epoxy resin or an acid anhydride as a curing agent is widely used.

However, when the epoxy resin composition is used as a sealing resin, internal stress is generated due to curing shrinkage during curing of the epoxy resin composition or strain caused by a difference in linear expansion coefficient between the epoxy resin and the optical semiconductor element. As a result, the optical semiconductor element deteriorates, and for example, when the optical semiconductor element is a light emitting element, there arises a problem that the brightness thereof decreases. Therefore, conventionally, as a method of reducing the internal stress, a method of adding an inorganic powder having a small coefficient of linear expansion such as silica powder to reduce the coefficient of linear expansion of the epoxy resin composition and making it similar to that of an optical semiconductor device has been used. It has been proposed and implemented in some cases (see Patent Document 1).

However, the method of approximating the linear expansion coefficient of the optical semiconductor element has a fatal drawback as the epoxy resin composition for encapsulating the optical semiconductor element, that is, the light transmittance of the cured epoxy resin composition is remarkably lowered. are doing. Therefore, in order to solve the above drawbacks, for example, a method of reducing the difference in refractive index between the cured product composed of a resin component and the glass powder which is an inorganic powder has been proposed (see Patent Document 2). ..<patcit num="1"><text>Japanese Unexamined Patent Publication No. 11-74424</text></patcit><patcit num="2"><text>Japanese Patent Application Laid-Open No. 2001-261933</text></patcit>

<p> However, in general, even if the refractive index of the resin component is adjusted to the average refractive index of the transparent inorganic particles obtained by the liquid immersion method or the like, the light transmittance of the cured molded product is determined by the transparent inorganic particles in the above method. It has a distribution in particle size, and the refractive index distribution between different particles cannot be ignored. From a microscopic point of view, the difference in refractive index between the resin and the transparent inorganic particles remains, so the light transmittance can be sufficiently increased. There is a problem that it cannot be done. Furthermore, even if an attempt is made to improve the transmittance by the average particle size, the specific surface area increases by reducing the average particle size, the reflection of light on the surface increases, and conversely, if the average particle size is large, the particle itself There is a high possibility that defects such as voids will occur inside the sealed cured product and the internal refractive index distribution, and it cannot be ignored, resulting in a decrease in light transmittance.</p><p> As described above, as a resin composition for encapsulating a high-performance optical semiconductor element such as a high-brightness LED, the conventional one cannot be said to be sufficient, and has higher light transmittance and excellent low stress property. An epoxy resin composition for encapsulating an optical semiconductor device is eagerly desired.</p><p> Further, the epoxy resin cured product obtained by dispersing silicon dioxide particles having a nano-order particle size in an epoxy resin reduces its coefficient of linear expansion while maintaining a high transmittance, and is used with an optical semiconductor element or a lead frame. Although it is possible to reduce the internal stress by reducing the difference in the coefficient of linear expansion, the viscosity of the sealing resin composition increases, so that the effects of high permeability and low coefficient of linear expansion can be obtained. There is a drawback that a sufficient amount of silicon dioxide particles cannot be blended.</p><p> The present invention has been made in view of such circumstances, and uses an epoxy resin composition for encapsulating an optical semiconductor device, which has a small internal stress and can obtain a good light transmittance in a wide temperature range, and an epoxy resin composition thereof. The purpose is to provide an optical semiconductor device.</p>

<p> In order to achieve the above object, the present invention is an epoxy resin composition for encapsulating an optical semiconductor device containing the following components (A) to (C), and the epoxy resin composition for encapsulating an optical semiconductor element. The relationship between the refractive index (n1) of the cured product obtained by curing a component other than the following glass powder [(C) component] and the refractive index (n2) of the above (C) component is the following formula (1). The first gist is an epoxy resin composition for encapsulating an optical semiconductor device that satisfies the above. (A) An epoxy resin composite in which an epoxy resin is used as a matrix component and the following (a) is dispersed therein. (a) Silicon dioxide particles with an average particle size of 5-40 nm, measured by small-angle neutron scattering (SANS). (B) Hardener. (C) Glass powder.<maths num="1"><img file="JP2005298701A_D0001.tif" /></maths></p><p> The second gist of the present invention is an optical semiconductor device in which an optical semiconductor element is resin-sealed using the epoxy resin composition for encapsulating an optical semiconductor element.</p><p> That is, the present inventors have made extensive studies to obtain a material for encapsulating an optical semiconductor device, which has a high light transmittance and an excellent effect of reducing internal stress. As a result, an epoxy resin composite in which very fine silicon dioxide particles having an average particle size of 5 to 40 nm, which is measured by neutron small angle scattering (SANS), is dispersed in the epoxy resin as a matrix component is used and filled. As a material, glass powder whose refractive index can be arbitrarily adjusted is used, and the difference between the refractive index of the cured product of the components other than the glass powder and the refractive index of the glass powder is set within a specific range, which is good. We have found that the light transmittance can be obtained and the linear expansion coefficient can be made to be close to that of the optical semiconductor element, and the internal stress can be reduced, and the present invention has been reached.</p>

<p> As described above, in the present invention, the epoxy resin composite [(A) component] and the curing agent [(B) component) are formed by using the epoxy resin as a matrix component and dispersing specific silicon dioxide particles (a) in the matrix component. ], And a glass powder [(C) component], and the refractive index (n1) of the cured product obtained by curing a component other than the above (C) component and the refractive index (n2) of the (C) component. ) Is an epoxy resin composition for encapsulating an optical semiconductor element that satisfies the above formula (1). Therefore, by blending the glass powder [(C) component], the coefficient of linear expansion of the cured product can be reduced, the internal stress can be reduced, and the deterioration of the optical semiconductor element can be effectively prevented. Moreover, since the epoxy resin composite [(A component) component] in which the specific silicon dioxide particles (a) are dispersed is used and the difference between the refractive indexes has a specific range, excellent light transmittance is obtained. be able to. Therefore, the optical semiconductor device in which the optical semiconductor element is sealed by the epoxy resin composition for encapsulating the optical semiconductor element of the present invention is excellent in reliability and transparency, and can fully exhibit its function.</p>

The epoxy resin composition for encapsulating an optical semiconductor device of the present invention is obtained by using a specific epoxy resin composite (component A), a curing agent (component B), and glass powder (component C). ..

The specific epoxy resin composite (component A) uses an epoxy resin as a matrix component, and specific silicon dioxide particles (a) having an average particle size of 5 to 40 nm measured by small-angle neutron scattering (SANS). Is dispersed.

Such an epoxy resin composite (component A) is produced, for example, as follows. First, the water content is 47% and Na₂SiO for O₂A commercially available aqueous alkali silicate solution having a ratio of 2.4 is diluted with desalted water until the desired water content is reached. This diluted solution is used to polycondensate the silicate to an average particle size range of 5-40 nm. That is, 100 parts by weight of the diluted solution (hereinafter abbreviated as "part") is applied to a commercially available acidic ion exchanger (alkali ion H) at a rate of 15 to 43 parts per hour.⁺Conducts to a column packed with (which has the effect of exchanging for ions and thereby initiating polycondensation) and then directing to a distillation apparatus where the deionized silicate solution supplied there is maintained at boiling temperature. Then, the distilled water is removed from the solution. After the end of supply, the resulting silicate sol is concentrated by further heating to adjust the pH value to 10.5 to 11.0 alkaline. By adjusting to alkaline, the formed silicon dioxide particles are stabilized against further polycondensation or aggregation.

Next, 5 to 7 parts of a silane coupling agent is added to 100 parts of the prepared silicate sol, and the mixture is stirred and mixed. Isopropanol is added to this mixture, and water is removed by atmospheric distillation to a content of less than 0.1% by weight as measured by the Karl Fischer method. To this is added an isopropanol solution of epoxy resin. Subsequently, by removing the volatile component by distillation, a transparent dispersion-type epoxy resin composite (component A) in which silicon dioxide particles having the above-mentioned average particle size in a specific range are dispersed can be obtained.

In the obtained epoxy resin composite (component A), silicon dioxide particles are dispersed in the epoxy resin which is a matrix component, and the average particle size of the silicon dioxide particles measured by small-angle neutron scattering (SANS) is measured. Is 5 to 40 nm. More preferably, the average particle size is in the range of 5 to 30 nm, and particularly preferably in the range of 10 to 25 nm. That is, if the average particle size exceeds 40 nm, the stability of the particle dispersion system (increased viscosity with time) becomes a problem, and if it is less than 5 nm, the dispersion resin system itself becomes highly viscous and a predetermined fluidity cannot be obtained. .. The small-angle neutron scattering (SANS) measurement method is a measurement method using a magnetic structure or a deuteration method for measuring nanoscale substances that are difficult to measure with an electron microscope or small-angle X-ray scattering.

Examples of the silane coupling agent to be added to the silicate sol include γ-aminopropyltrimethoxysilane, γ-aminopropylmethyldiethoxysilane, γ-aminopropyldimethylmethoxysilane, glycidyloxypropyltrimethoxysilane, and glycidyl. Oxypropyldimethylmethoxysilane, methacryloxypropyltrimethoxysilane, chloropropyltrimethoxysilane, vinylmethyldimethoxysilane, vinyltrispropeneoxysilane, vinyldimethylbutanoneoxymsilane, vinyltrisbutanoneoxymsilane, trimethylchlorosilane, vinyldimethylchlorosilane, dimethyl Examples thereof include chlorosilane and vinylmethylchlorosilane. These are used alone or in combination of two or more.

The epoxy resin is not particularly limited, and various conventionally known epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, novolak type epoxy resin, alicyclic epoxy resin, and water-added bisphenol A are used. Examples thereof include type epoxy resins, aliphatic epoxy resins, glycidyl ether type epoxy resins, and bisphenol S type epoxy resins. These can be used alone or in combination of two or more. Among these epoxy resins, bisphenol A type epoxy resin, bisphenol F type epoxy resin, novolac type epoxy resin, and alicyclic epoxy resin are preferably used from the viewpoint of excellent transparency and discoloration resistance.

The content of the silicon dioxide particles (a) dispersed in the epoxy resin composite (component A) thus obtained is preferably in the range of 5 to 50% by weight of the entire epoxy resin composition. More preferably, it is 10 to 40% by weight. That is, if it is less than 5% by weight, it is difficult to obtain the desired mechanical properties, and if it exceeds 50% by weight, the change in viscosity of the silicon dioxide particle dispersion resin with time tends to be significantly large. is there.

In the epoxy resin composition for encapsulating an optical semiconductor device of the present invention, an epoxy resin is used alone in combination with an epoxy resin composite (component A) in which the specific silicon dioxide particles (a) are dispersed. You may.

Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, novolac type epoxy resin such as phenol novolac type epoxy resin and cresol novolac type epoxy resin, alicyclic epoxy resin, triglycidyl isocyanurate, and hydantin. Nitrogen-containing ring epoxy resin such as epoxy resin, water-added bisphenol A type epoxy resin, aliphatic epoxy resin, glycidyl ether type epoxy resin, bisphenol S type epoxy resin, biphenyl type epoxy resin which is the mainstream of low water absorption cured product type , Dicyclocyclic epoxy resin, naphthalene type epoxy resin and the like. These can be used alone or in combination of two or more. Among these epoxy resins, it is preferable to use bisphenol A type epoxy resin, bisphenol F type epoxy resin, novolac type epoxy resin, alicyclic epoxy resin, and triglycidyl isocyanurate from the viewpoint of excellent transparency and discoloration resistance. ..

The epoxy resin may be solid or liquid at room temperature, but generally, the epoxy resin used preferably has an average epoxy equivalent of 90 to 1000, and in the case of solid, the softening point is 160 ° C or less. Is preferable. That is, when the epoxy equivalent is less than 90, the cured product of the epoxy resin composition for encapsulating the optical semiconductor element may become brittle. Further, when the epoxy equivalent exceeds 1000, the glass transition temperature (Tg) of the cured product may be lowered. In the present invention, the above-mentioned normal temperature means a range of 5 to 35 ° C.

When the epoxy resin is used in combination with the epoxy resin composite (component A), the combined ratio is based on the mixing ratio of the epoxy resin composite (component A) and the curing agent (component B) described later, and the entire epoxy resin component is used. And the curing agent (B component) are preferably set so as to have a blending ratio described later.

Examples of the curing agent (B component) include acid anhydride-based curing agents and phenol-based curing agents. Examples of the acid anhydride-based curing agent include phthalic anhydride, maleic anhydride, trimellitic anhydride, pyromellitic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methylnadic anhydride, nadicic anhydride, and anhydrous. Examples thereof include glutaric acid, methylhexahydrophthalic anhydride, and methyltetrahydrophthalic anhydride. These can be used alone or in combination of two or more. Among these acid anhydride-based curing agents, it is preferable to use phthalic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, and methylhexahydrophthalic anhydride. The acid anhydride-based curing agent preferably has a molecular weight of about 140 to 200, and a colorless to pale yellow acid anhydride is preferable.

On the other hand, examples of the phenol-based curing agent include phenol novolac resin-based curing agents.

The mixing ratio of the epoxy resin composite (component A) and the curing agent (component B) is the epoxy group in the curing agent (component B) with respect to 1 equivalent of the epoxy group in the epoxy resin composite (component A). It is preferable to set the ratio so that the number of active groups (acid anhydride groups or hydroxyl groups) capable of reacting with the above is 0.5 to 1.5 equivalents, and more preferably 0.7 to 1.2 equivalents. That is, when the number of active groups is less than 0.5 equivalent, the curing rate of the epoxy resin composition for encapsulating an optical semiconductor device becomes slower, and the glass transition temperature of the cured product tends to decrease, which exceeds 1.5 equivalents. This is because the moisture resistance tends to decrease.

Further, as the curing agent (component B), in addition to the acid anhydride-based curing agent and the phenol-based curing agent, conventionally known curing agents for epoxy resins, for example, amine-based curing agents, may be used depending on the purpose and application thereof. , The above-mentioned acid anhydride-based curing agent partially esterified with alcohol, or a curing agent for polyvalent carboxylic acids such as hexahydrophthalic acid, tetrahydrophthalic acid, and methylhexahydrophthalic acid alone, or an acid anhydride-based curing agent. It may be used in combination with a curing agent and a phenolic curing agent. For example, when a polyvalent carboxylic acid curing agent is used in combination, the resin composition reacts rapidly with the epoxy resin to obtain a B-stage (semi-curing) resin composition having the required viscosity without gelation. It is possible to improve the productivity of goods. Even when these curing agents are used, the blending ratio may be the same as the blending ratio (equivalent ratio) when the acid anhydride-based curing agent and the phenol-based curing agent are used.

As the glass powder (C component) used together with the above A component and B component, SiO₂Alone or SiO₂And B₂O₃The main component is. The glass powder preferably contains at least one component selected from the group consisting of zinc, titanium, cerium, bismuth, lead, and selenium in addition to the main component. For example, when zinc is blended, it is usually blended as ZnO, and its content is preferably set to be 1 to 10% by weight of the entire glass powder. In addition, when titanium is blended, it is usually TiO.₂It is preferable that the content is set so as to be 1 to 10% by weight of the whole glass powder.

On the other hand, in order to adjust the refractive index of the glass powder (C component), Na₂O, Al₂O₃, CaO, BaO and the like are preferably blended as appropriate.

Then, the glass powder (C component) can be obtained, for example, by melting each of the above raw materials and quenching and pulverizing the glass frit produced by using a ball mill or the like. If bubbles are present in the glass frit, the light transmittance is lowered due to the reflection of light at the bubble interface. Therefore, it is necessary to raise the melting temperature so that the bubbles are sufficiently removed. At the time of the above crushing, the surface of the glass powder may be contaminated by metal parts such as a crusher. Therefore, it is preferable to use a metal having high wear resistance or a ceramic sprayed metal for the parts of the crusher. The obtained pulverized glass powder may be used as it is, but for example, it is preferable to use it as a spherical glass powder whose surface is framed (flame) treated to form a spheroid. Since the spherical glass powder has no surface bubbles or cracks, light scattering at the interface between the resin component and the glass powder is small, and the light transmittance of the obtained cured product can be improved. Then, during the frame treatment, incomplete combustion is avoided and carbides are prevented from adhering to the surface. Further, in order to prevent the particles of the glass powder from aggregating with each other to form a snowball, it is preferable to adjust so that the amount of the glass powder charged into the frame processing does not increase. Further, the particle size of the spherical glass powder obtained by adjusting the particle size of the glass powder before the frame treatment by using a sieve or the like can be easily adjusted, and a glass powder having a high degree of sphericity can be obtained.

The glass powder thus obtained is preferably obtained by, for example, a sieve or the like having a predetermined particle size, and the glass powder (C component) includes the viscosity and molding of the resin component when the glass powder is mixed. Considering the formability such as gate clogging at the time, the average particle size is preferably 5 to 100 μm.

The content of the glass powder (C component) is preferably set to 60% by weight or less of the entire epoxy resin composition, and particularly preferably 50% by weight or less. The lower limit of the content of the glass powder (C component) is usually 5% by weight. That is, when the content exceeds 60% by weight, the scattering ratio at the interface becomes high, and the transmittance tends to decrease.

The total content of the silicon dioxide particles (a) and the glass powder (C component) in the epoxy resin composite (component A) is in the range of 10 to 75% by weight of the entire epoxy resin composition. It is preferable to set it. Particularly preferably, it is 10 to 60% by weight. That is, if it is less than 10% by weight, it is difficult to expect a sufficient decrease in the coefficient of linear expansion, and if it exceeds 75% by weight, the melt viscosity of the resin composition becomes too high, and a good molded product can be obtained. This is because it tends to be difficult.

In the epoxy resin composition for encapsulating an optical semiconductor device of the present invention, the refractive index (n1) of the cured product obtained by curing a component other than the glass powder (C component) and the glass powder (C component) are The relationship with the refractive index (n2) must satisfy the following equation (1). That is, if the relationship between the refractive indexes of the two satisfies the above relationship, the light transmittance at each wavelength can be improved.

<maths num="2"><img file="JP2005298701A_D0002.tif" /></maths>

Further, the relationship between the refractive index (n1) of the cured product obtained by curing a component other than the glass powder (C component) and the refractive index (n2) of the glass powder (C component) is the following equation (2). Is particularly preferable.

<maths num="3"><img file="JP2005298701A_D0003.tif" /></maths>

Each of the above refractive indexes can be measured by, for example, an immersion method. That is, the particles are dispersed in various liquids having different refractive indexes, and the refractive index of the liquid with respect to the sodium D line is Abbe for the dispersion liquid having the highest transmittance for light having a wavelength of 589.3 nm at 25 ° C. It can be measured with a refractive index meter.

As described above, in order to have the above-mentioned relationship between the refractive index of the cured product of the resin component and the glass powder (C component), for example, a method of adjusting the refractive index of the cured product of the resin component ( For example, selection of epoxy resin type, combination of two or more types of epoxy resin, selection of type of curing agent, combination of two or more types of curing agent, etc.), method of adjusting the refractive index of glass powder (C component) ( For example, selection of raw material composition, adjustment of blending ratio, etc.), and a method of using these two methods together can be mentioned. Normally, the refractive index of the glass powder (C component) is brought close to that of the cured resin component to some extent, and then the refractive index of the cured resin component is further adjusted to obtain the cured resin component and the glass powder. Adjust the difference in refractive index from (C component) to be even smaller.

More specifically, for example, in the above resin component, in the case of a combination in which the epoxy resin is triglycidyl isocyanurate and the curing agent is an acid anhydride-based curing agent, which is exemplified as a preferable combination of the epoxy resin and the curing agent. The composition of the glass powder, SiO₂-B₂O₃-ZnO-Al₂O₃-CaO-Sb₂O₃In its composition, each component is SiO₂Is 45 ~ 55% by weight, B₂O₃Is 10 to 25% by weight, ZnO is 1 to 6% by weight, Al₂O₃10-18% by weight, CaO 7-20% by weight, Sb₂O₃Is preferably adjusted so as to be blended in a proportion of 0.1 to 5% by weight.

When the epoxy resin is a bisphenol A type epoxy resin and a novolac type epoxy resin and the curing agent is a phenolic curing agent, the composition of the glass powder is changed to SiO.₂-B₂O₃-TiO₂-Al₂O₃-CaO-BaO or SiO₂-TiO₂-Al₂O₃-As CaO-BaO, in its composition, each component is SiO₂Is 40-55% by weight, B₂O₃Is 0 ~ 2% by weight, TiO₂Is 1 to 7% by weight, Al₂O₃Is preferably 12 to 17% by weight, CaO is 25 to 35% by weight, and BaO is 5 to 10% by weight.

Then, in order to minimize the decrease in light transmission rate, it is preferable that the specific silicon dioxide particles have a maximum filling amount, and the shortage is supplemented with the glass powder (C component) to fill the entire inorganic material. It is preferable to obtain the amount of the agent (silicon dioxide particles and glass powder). However, as long as the light transmittance is not impaired, even if the content of the inorganic filler is feasible by using only the silicon dioxide particles, the glass powder (C component) is used in combination to obtain a desired inorganic filler. This is possible to increase the degree of freedom in formulation design.

Further, in the epoxy resin composition for encapsulating an optical semiconductor element of the present invention, an epoxy resin composite (component A), a curing agent (component B) and a glass powder (component C) formed by dispersing the specific silicon dioxide particles. ), In some cases more epoxy resins, and if necessary, conventionally used, for example, curing accelerators, anti-deterioration agents, modifiers, silane coupling agents, defoaming agents, leveling agents, mold release agents. , Dyes, pigments and other known additives may be appropriately blended.

The curing accelerator is not particularly limited, and examples thereof include 1,8-diazabicyclo (5,4,0) undecene-7, triethylenediamine, tri-2,4,6-dimethylaminomethylphenol and the like. Tertiary amines, imidazoles such as 2-ethyl-4-methylimidazole, 2-methylimidazole, triphenylphosphine, tetraphenylphosphonium / tetraphenylborate, tetra-n-butylphosphonium-o, o-diethylphosphorodithio Examples thereof include phosphorus compounds such as ate, quaternary ammonium salts, organometal salts, and derivatives thereof. These may be used alone or in combination of two or more. Among these curing accelerators, it is preferable to use tertiary amines, imidazoles, and phosphorus compounds.

The content of the curing accelerator is preferably set to 0.01 to 8.0 parts, more preferably 0.1 to 3.0 parts, with respect to 100 parts of the epoxy resin composite (component A). That is, if it is less than 0.01 part, it is difficult to obtain a sufficient curing promoting effect, and if it exceeds 8.0 parts, discoloration may be observed in the obtained cured product.

Examples of the deterioration inhibitor include conventionally known deterioration inhibitors such as phenol-based compounds, amine-based compounds, organic sulfur-based compounds, and phosphine-based compounds. Examples of the denaturing agent include conventionally known denaturing agents such as glycols, silicones, and alcohols. Examples of the silane coupling agent include conventionally known silane coupling agents such as silane-based and titanate-based agents. In addition, examples of the defoaming agent include conventionally known defoaming agents such as silicone-based defoaming agents.

Then, the epoxy resin composition for encapsulating an optical semiconductor device of the present invention can be obtained in the form of a liquid, a powder, or a tablet in which the powder is tableted, for example, by producing the composition as follows. That is, in order to obtain a liquid epoxy resin composition for encapsulating an optical semiconductor device, for example, the above-mentioned components, that is, the above-mentioned components A to C, and other components to be blended as necessary may be appropriately blended. .. Further, in order to obtain a powder or a tablet obtained by tableting the powder, for example, the above-mentioned components are appropriately blended, premixed, kneaded using a kneader, melt-mixed, and then melt-mixed. It can be produced by cooling it to room temperature, pulverizing it by a known means, and locking it if necessary.

The epoxy resin composition for encapsulating an optical semiconductor device of the present invention thus obtained is used for encapsulating an optical semiconductor element such as an LED or a charge-coupled device (CCD). That is, the use of the epoxy resin composition for encapsulating an optical semiconductor element of the present invention is not particularly limited in encapsulating an optical semiconductor element, and is a known molding method such as ordinary transfer molding or casting. Can be done by. When the epoxy resin composition for encapsulating an optical semiconductor device of the present invention is in a liquid state, at least the epoxy resin component and the curing agent are stored separately and mixed immediately before use, so-called two liquids. It may be used as a type. Further, when the epoxy resin composition for encapsulating an optical semiconductor device of the present invention is in the form of powder or tablet, it is set in the B stage (semi-cured state) when the above-mentioned components are melt-mixed. May be heated and melted at the time of use.

If the optical semiconductor element is sealed with the epoxy resin composition for encapsulating the optical semiconductor element of the present invention, the internal stress is small, the deterioration of the optical semiconductor element can be effectively prevented, and it is good at all wavelengths. Light transmittance can be obtained. Therefore, the optical semiconductor device of the present invention in which the optical semiconductor element is sealed by the epoxy resin composition for encapsulating the optical semiconductor element of the present invention is excellent in reliability and transparency, and the light transmittance at each wavelength fluctuates. There are few, and the function can be fully exhibited.

Next, Examples will be described together with Comparative Examples.

Prior to the examples, each component shown below was prepared.

[Epoxy resin a] Bisphenol A type epoxy resin (epoxy equivalent 190)

[Epoxy resin b] Triglycidyl isocyanurate (epoxy equivalent 100)

[Silicon dioxide particle dispersed epoxy resin a] Hanze-Chemi, NANOPOX XP 22/0543 [Bisphenol A type epoxy resin (epoxy equivalent 190), solid content 50% by weight, average particle size of silicon dioxide particles 15 nm]

[Silicon dioxide particle dispersed epoxy resin b] Hanze-Chemi, NANOPOX XP 22/0316 [Alicyclic epoxy resin (epoxy equivalent 150), solid content 50% by weight, average particle size of silicon dioxide particles 15 nm]

[Acid anhydride-based curing agent] A mixture of 4-methylhexahydrophthalic anhydride (x) and hexahydrophthalic anhydride (y) (mixed weight ratio x: y = 7: 3) (acid anhydride equivalent 168)

[Glass powder a] Spherical glass powder (SiO) having a CaO composition and obtained by frame treatment.₂: 57.0% by weight, B₂O₃: 3.0% by weight, SrO: 6.5% by weight, Al₂O₃15.0% by weight, CaO: 18.0% by weight, average particle size 35 μm, maximum particle size 75 μm, refractive index: 1.56)

[Glass powder b] Spherical glass powder (SiO) having a CaO composition and obtained by frame treatment.₂: 51.0% by weight, B₂O₃: 20.5% by weight, ZnO: 2.9% by weight, Al₂O₃15.1% by weight, CaO: 9.9% by weight, Sb₂O₃: 0.5% by weight, average particle size 35 μm, maximum particle size 75 μm, refractive index: 1.53)

[Coupling agent] Silane coupling agent containing mercapto (manufactured by Shin-Etsu Chemical Co., Ltd., KBM-803)

[Curing accelerator] 2-Ethyl-4-methylimidazole

[Antioxidant] t-Butylhydroxytoluene

[Examples 1 to 6, Comparative Examples 1 to 6] Each component shown in Tables 1 to 2 below is blended in the ratio shown in the same table, melt-mixed at 80 to 110 ° C, cooled and solidified, and then pulverized. The desired epoxy resin composition was prepared by tableting in the form of a tablet.

<tables num="1"><img file="JP2005298701A_D0004.tif" /></tables>

<tables num="2"><img file="JP2005298701A_D0005.tif" /></tables>

Using each of the epoxy resin compositions thus obtained, the light transmittance and the coefficient of linear expansion of the cured product were measured and evaluated according to the following methods, respectively. Further, the difference (n2-n1) between the refractive index (n1) of the cured product obtained by curing the components of each epoxy resin composition excluding the spherical glass powder and the refractive index (n2) of the spherical glass powder is determined by the above-mentioned method. Measured and calculated according to. The molding conditions for the cured product were 150 ° C × 2 hours. On the other hand, using each of the obtained epoxy resin compositions, an optical semiconductor device was produced according to the following method, the wire breakage defect rate was measured, and the appearance was evaluated. These results are shown in Tables 3 to 4 below.

[Light Transmittance] Using each epoxy resin composition, a cured product having a thickness of 1 mm was prepared (curing conditions: 150 ° C × 2 hours). Then, using the above-mentioned cured product, the light transmittance at a wavelength of 589.3 nm at room temperature (25 ° C) was measured using a spectrophotometer UV3101 manufactured by Shimadzu Corporation.

[Coefficient of linear expansion] Using each epoxy resin composition, a cured product having a thickness of 1 mm was prepared (curing conditions: 150 ° C × 2 hours). Then, using the above-mentioned cured product, a thermal analyzer (TMA-50, manufactured by Shimadzu Corporation) was used to determine the coefficient of linear expansion (α1) at a temperature lower than the glass transition temperature at a heating rate of 2 ° C / min. It was measured.

[Wire breaking defect rate] Using each epoxy resin composition, a GaP LED is sealed as a bullet-shaped lamp with a diameter of 5 mm by potting (150 ° C x 2 hours), and further cured at 150 ° C for 3 hours. To produce an optical semiconductor device. Then, the wire breakage defect rate (%) after 200 cycles was measured under the thermal cycle condition of -25 ° C × 30 minutes 125 ° C × 30 minutes for one cycle. The number of samples (n number) of each optical semiconductor device was set to 24.

[Appearance] The appearance of the optical semiconductor device produced as described above was visually evaluated. Then, the one in which yellowing was confirmed was evaluated as x, and the one in which there was no problem in appearance was evaluated as .

<tables num="3"><img file="JP2005298701A_D0006.tif" /></tables>

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From the above results, it is clear that the example product has a small wire breakage defect rate and a small coefficient of linear expansion, so that the internal stress is reduced. Moreover, an optical semiconductor device having high light transmittance and excellent reliability was obtained.

On the other hand, the product of Comparative Example 1 has a high light transmittance because it does not contain silicon dioxide particles and glass powder, but has a remarkably high wire breakage defect rate and a high linear expansion coefficient, and is reliable. It is inferior in sex. In addition, the two products of Comparative Example used only glass powder without blending silicon dioxide particles, and the difference in refractive index (n2-n1) was 0.020, which was out of the predetermined range, and the light transmittance was extremely low. .. In Comparative Examples 3 and 6, since only silicon dioxide particles were used, the light transmittance was high, but the appearance turned yellow. In Comparative Examples 4 and 5, the light transmittance was low because only the glass powder was used without using the silicon dioxide particles.