JP2014141607A - Silicone resin composition and light emission diode and semiconductor light emission device each using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain, by targeting a system using a silicone resin not adversely affecting merits of a silicone material having favorable transparency, heat resistance, and light resistance and silicone resin particulates whose refractive index matches that of the former, a technique yielding, in a case where a phosphor is included therein, a high precipitation inhibitory effect.SOLUTION: The provided silicone resin composition comprises: a silicone resin; and silicone particulates. The respective concentrations of acetate ions, chloride ions, ammonium ions, and alkali metal ions with respect to the solid content thereof are each 5 ppm or below.

Description

  The present invention relates to a silicone resin composition. Specifically, a semiconductor light emitting device configured to convert a light emitting diode chip emission color by mixing a fluorescent material into a sealing resin by utilizing the property of a fluorescent material that shifts the wavelength of light to a longer wavelength side. The present invention relates to a silicone resin composition to be used.

  Light-emitting diodes (LEDs) are characterized by their remarkable improvement in luminous efficiency, featuring low power consumption, long service life, and design, etc., for LCD backlights, in-vehicle use, and general lighting. The market is expanding rapidly. On the other hand, since the emission spectrum of an LED depends on the semiconductor material that composes the LED, in order to obtain white light for LCD backlights and general illumination, phosphors corresponding to the respective emission colors are installed on the LED chip. There is a need. Specifically, a method of installing a yellow phosphor on a blue LED chip, a method of installing red and green phosphors on a blue LED chip, and a red, green, and blue phosphor on an ultraviolet LED chip. Proposed methods such as installing phosphors, but from the viewpoint of the luminous efficiency and cost of LED chips, installing yellow phosphors on blue LED chips, installing red and green phosphors on blue LED chips The most widely adopted method is currently used.

  As one method of installing the phosphor on the LED chip, a method of sealing the LED chip with a resin composition in which the phosphor is dispersed is performed. As the resin composition, a silicone resin is often used because of its excellent transparency, heat resistance, and light resistance.

  As phosphors, inorganic phosphors that are excellent in luminous efficiency and durability and that use rare earth elements as the emission center are widely used. However, since such phosphors have high specific gravity, they are dispersed in silicone resin. In this case, since the liquid crystal is easily settled, the phosphor concentration of the semiconductor light emitting device sealed therewith is not stable, and there is a problem that the emission color varies.

  In order to prevent sedimentation of the phosphor, a method has been studied in which fine particles other than the phosphor are dispersed in the silicone resin and sedimentation is prevented by the interaction. A method for suppressing sedimentation of the phosphor by dispersing a finer powder than the phosphor, such as silica, in a silicone resin has been studied (for example, see Patent Document 1). However, when particles other than the phosphor are dispersed in the silicone resin, there is a drawback that the optical performance is lowered due to light scattering and reflection. As a method of solving the optical problem, a technique for suppressing phosphor sedimentation by using fine particles dispersed in a silicone resin as fine silicone resin particles having the same refractive index has been studied (for example, see Patent Documents 2 and 3). ).

JP 2005-64233 A JP 2006-339581 A International Publication No. 2011/102272

  However, when silicone fine particles are used, the degree of suppression of phosphor settling is slightly lower than that of inorganic fine particles, and the result may be unstable.

  The present invention pays attention to the above problems, and in a system using silicone resin fine particles having a refractive index matched with a silicone resin that does not impair the characteristics of a silicone material having good transparency, heat resistance, and light resistance, a phosphor is contained. It is to obtain a technique having a high sedimentation suppression effect.

  As a result of intensive studies on a method for suppressing sedimentation of the phosphor contained in the silicone resin composition, the inventors have highly removed acid / base components derived from the synthesis of the silicone fine particles contained therein, It has been found that by reducing the concentration of impurities therein, the effect of suppressing phosphor sedimentation when the phosphor particles are mixed is significantly increased.

  That is, the present invention comprises a silicone resin and silicone fine particles, and the concentration of acetate ions, chloride ions, ammonium ions and alkali metal ions in the solid content is all 5 ppm or less. It is.

  ADVANTAGE OF THE INVENTION According to this invention, the silicone resin composition excellent in the suppression of fluorescent substance sedimentation when a fluorescent substance is mixed, and its use, making use of the characteristic of the silicone material that transparency, heat resistance, and light resistance are good. The semiconductor light emitting device can be provided.

Sectional drawing which shows an example of embodiment of the semiconductor light-emitting device concerning this invention Sectional drawing which shows an example of another embodiment of the semiconductor light-emitting device concerning this invention

  The silicone resin used in the present invention can be used without particular limitation as long as it is liquid and has excellent transparency, heat resistance, and light resistance. In particular, curable silicone rubber is preferable. Either one liquid type or two liquid type (three liquid type) liquid structure may be used. Examples of the curable silicone rubber include a dealcohol-free type, a deoxime type, a deacetic acid type, and a dehydroxylamine type that cause a condensation reaction with moisture in the air or a catalyst. Moreover, there is an addition reaction type as a type that causes a hydrosilylation reaction with a catalyst. Any of these types of curable silicone rubber may be used. In particular, the addition reaction type silicone rubber is more preferable in that it has no by-product accompanying the curing reaction, has a small curing shrinkage, and can easily be cured by heating.

  The addition reaction type silicone rubber is formed, for example, by subjecting a compound containing an alkenyl group bonded to a silicon atom and a compound having a hydrogen atom bonded to a silicon atom to a hydrosilylation reaction using a catalyst. Such materials contain alkenyl groups bonded to silicon atoms such as vinyltrimethoxysilane, vinyltriethoxysilane, allyltrimethoxysilane, propenyltrimethoxysilane, norbornenyltrimethoxysilane, octenyltrimethoxysilane, etc. And hydrogen atoms bonded to silicon atoms such as methylhydrogenpolysiloxane, dimethylpolysiloxane-CO-methylhydrogenpolysiloxane, ethylhydrogenpolysiloxane, methylhydrogenpolysiloxane-CO-methylphenylpolysiloxane, etc. Examples thereof include those formed by hydrosilylation reaction of the compounds having them. In addition, for example, known ones as described in JP 2010-159411 A can be used.

  Additives such as a silane coupling agent as a sheet surface modifier when a dispersing agent or leveling agent for stabilizing a coating film is added as an additive, or a silicone resin composition is formed into a sheet shape Etc. can also be added.

  The silicone fine particles used in the present invention are preferably fine particles comprising a silicone resin and / or silicone rubber. In particular, silicone fine particles obtained by a method of hydrolyzing organosilane such as organotrialkoxysilane, organodialkoxysilane, organotriacetoxysilane, organodiacetoxysilane, organotrioxime silane, organodioxime silane, and then condensing them. preferable.

  Examples of the organotrialkoxysilane include methyltrimethoxysilane, methyltriethoxysilane, methyltri-n-proxysilane, methyltri-i-proxysilane, methyltri-n-butoxysilane, methyltri-i-butoxysilane, methyltri-s-butoxy Silane, methyltri-t-butoxysilane, ethyltrimethoxysilane, n-propyltrimethoxysilane, i-propyltrimethoxysilane, n-butyltributoxysilane, i-butyltributoxysilane, s-butyltrimethoxysilane, t Examples include -butyltributoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, vinyltrimethoxysilane, and phenyltrimethoxysilane.

  Examples of the organodialkoxysilane include dimethyldimethoxysilane, dimethyldiethoxysilane, methylethyldimethoxysilane, methylethyldiethoxysilane, diethyldiethoxysilane, diethyldimethoxysilane, 3-aminopropylmethyldiethoxysilane, N- (2- Aminoethyl) -3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl) -3-aminoisobutylmethyldimethoxysilane, N-ethylaminoisobutylmethyldiethoxysilane, (phenylaminomethyl) methyldimethoxysilane, vinylmethyl Examples include diethoxysilane.

  Examples of organotriacetoxysilane include methyltriacetoxysilane, ethyltriacetoxysilane, and vinyltriacetoxysilane.

  Examples of the organodiacetoxysilane include dimethyldiacetoxysilane, methylethyldiacetoxysilane, vinylmethyldiacetoxysilane, vinylethyldiacetoxysilane, and the like.

  Examples of the organotrioxime silane include methyl trismethyl ethyl ketoxime silane, vinyl trismethyl ethyl ketoxime silane, and examples of the organodioxime silane include methyl ethyl bismethyl ethyl ketoxime silane.

  Specifically, such particles are reported in Japanese Unexamined Patent Publication No. 63-77940, Japanese Unexamined Patent Publication No. 6-248081, Japanese Unexamined Patent Publication No. 2003-342370. Or a method reported in JP-A-4-88022. In addition, organosilane such as organotrialkoxysilane, organodialkoxysilane, organotriacetoxysilane, organodiacetoxysilane, organotrioxime silane, organodioxime silane and / or a partial hydrolyzate thereof are added to an alkaline aqueous solution, Hydrolysis / condensation to obtain particles, or addition of organosilane and / or partial hydrolyzate thereof to water or acidic solution to obtain hydrolyzed partial condensate of organosilane and / or partial hydrolyzate thereof Thereafter, a method in which an alkali is added to proceed with a condensation reaction to obtain particles, an organosilane and / or a hydrolyzate thereof is used as an upper layer, an alkali or a mixed solution of an alkali and an organic solvent is used as a lower layer, and the organosilane at these interfaces. And / or hydrolyzate thereof · Polycondensation engaged with is also known a method of obtaining a particle, In any of these methods, it is possible to obtain the particles used in the present invention.

  Among these, the reaction as reported in Japanese Patent Application Laid-Open No. 2003-342370 in producing spherical organopolysilsesquioxane fine particles by hydrolyzing and condensing organosilane and / or a partial hydrolyzate thereof. It is preferable to use silicone fine particles obtained by a method of adding a polymer dispersant in the solution.

  In the production of particles, organosilane and / or a partial hydrolyzate thereof are hydrolyzed / condensed in the presence of a polymer dispersant and a salt that act as a protective colloid in a solvent in an acidic aqueous solution. Silicone fine particles produced by adding a silane and / or a hydrolyzate thereof to obtain a hydrolyzate and then adding an alkali to advance the condensation reaction can also be used.

The polymer dispersant is a water-soluble polymer, and any synthetic polymer or natural polymer can be used as long as it acts as a protective colloid in a solvent. Specifically, polyvinyl alcohol, polyvinyl pyrrolidone and the like can be used. It can be illustrated. As a method for adding the polymer dispersant, a method of adding in advance to the reaction initial solution, a method of adding organotrialkoxysilane and / or a partial hydrolyzate thereof simultaneously, an organotrialkoxysilane and / or a partial hydrolyzate thereof, The method of adding after hydrolyzing partial condensation can be illustrated, and any of these methods can be selected. Here, the addition amount of the polymer dispersant is preferably in the range of 5 × 10 ⁻⁷ to 10 ⁻² parts by weight with respect to 1 part by weight of the reaction liquid volume, and in this range, aggregation of particles hardly occurs.

  The organic substituent contained in the silicone fine particles is preferably a methyl group or a phenyl group, and the refractive index of the silicone fine particles can be adjusted by the content of these substituents. When it is desired to use the light passing through the silicone resin as the binder resin without scattering in order not to reduce the brightness of the LED, in the cured product of the silicone resin composition, the refractive index d1 of the silicone fine particles, the silicone fine particles, and the fluorescence It is preferable that the refractive index difference of the refractive index d2 due to components other than the body is small. The difference between the refractive index d1 of the silicone fine particles and the refractive index d2 of the components other than the silicone fine particles and the phosphor is preferably less than 0.10, and more preferably 0.03 or less. By controlling the refractive index within the range, reflection / scattering at the interface between the silicone fine particles and the silicone composition is reduced, high transparency and light transmittance are obtained, and the brightness of the LED is not lowered.

  For the measurement of the refractive index, Abbe refractometer, Pulfrich refractometer, immersion type refractometer, immersion method, minimum declination method, etc. are used as the total reflection method, but for the refractive index measurement of the silicone composition, The immersion method is useful for measuring the refractive index of Abbe refractometer and silicone fine particles.

  The means for controlling the refractive index difference can be adjusted by changing the amount ratio of the raw materials constituting the silicone fine particles. That is, for example, by adjusting the mixing ratio of methyltrialkoxysilane and phenyltrialkoxysilane, which are raw materials, and increasing the composition ratio of methyl groups, it is possible to achieve a refractive index close to 1.4. On the contrary, a relatively high refractive index can be achieved by increasing the constituent ratio of the phenyl group.

  In the present invention, the average particle diameter of the silicone fine particles is represented by a median diameter (D50). The average particle size of the silicone fine particles is not particularly limited in order to exert the effect of the present invention, but the average particle size is preferably 0.01 μm or more as a lower limit, and more preferably 0.05 μm or more. . The upper limit is preferably 2.0 μm or less, and more preferably 1.0 μm or less. When the average particle size is 0.01 μm or more, it is easy to produce particles with a controlled particle size, and when the average particle size is 2.0 μm or less, the optical properties of the phosphor sheet are improved. Moreover, when the average particle diameter is 0.01 μm or more and 2.0 μm or less, the excellent effect of suppressing the sedimentation of the phosphor, which is an object of the present invention, can be obtained. Moreover, it is preferable to use monodispersed true spherical particles. In the present invention, the average particle diameter, that is, the median diameter (D50) and the particle size distribution of the silicone fine particles contained in the resin composition can be measured by SEM observation of a cross section of the cured product of the resin composition. A particle size distribution is obtained by performing image processing on a measurement image obtained by SEM, and in the particle size distribution obtained therefrom, the particle diameter of 50% of the accumulated portion from the small particle diameter side is obtained as the median diameter D50. The average particle size of the silicone fine particles determined from the cross-sectional SEM image is theoretically 78.5% compared to the true average particle size, and is actually about 70% to 85%. The average particle diameter is defined as a value obtained by the above measurement method.

  The reason why the value of D50 is smaller than when the silicone fine particles are directly observed is that the diameter is correctly measured when the silicone fine particles are directly observed, but the silicone fine particles are measured when the cross section is measured. This is because is not always cut at the equator plane. Assuming that the silicone microparticles are spherical and are cut at any location, the apparent diameter is theoretically 78.5% of the true diameter (the area of a circle with a diameter of 1 and a square with a side of 1). Equivalent to the area ratio). Actually, since the silicone fine particles are not true spheres, it is empirically about 70% to 85%.

  Although there is no restriction | limiting in particular as content of a silicone fine particle when the effect of this invention is exhibited, It is preferable that it is 1 weight part or more as a minimum with respect to 100 weight part of silicone resins, 2 weight part or more More preferably. Further, the upper limit is preferably 20 parts by weight or less, and more preferably 10 parts by weight or less. By containing 1 part by weight or more of silicone fine particles, a particularly good phosphor dispersion stabilizing effect can be obtained. On the other hand, the content of 20 parts by weight or less does not excessively increase the viscosity of the silicone composition.

  The above-mentioned silicone fine particles generally contain ionic impurities derived from the production process, but it is important to remove them by washing in order to exhibit an excellent phosphor sedimentation suppressing effect. These ionic impurities include sodium ions derived from alkali metal hydroxides such as sodium hydroxide and potassium hydroxide used as a polymerization catalyst during the production of silicone fine particles, alkali metal ions typified by potassium ions, and after polymerization. Examples include acetic acid ions derived from acetic acid, ammonium ions derived from ammonium chloride used for salting out and sedimentation of particles, and chloride ions. Silicone resins for LEDs with reduced ionic impurities are commercially available, but these ionic impurities are very likely to be mixed into the silicone fine particles in the manufacturing process as described above, and are difficult to remove. Due to the presence of these ionic impurities, the phosphor sedimentation suppressing effect is significantly reduced. In order to obtain an excellent effect of suppressing phosphor sedimentation, the concentration of alkali metal ions, ammonium ions, acetate ions and chloride ions in the solid content of the silicone resin composition in which silicone fine particles are dispersed is 5 ppm or less. is necessary. More desirably, it is 1 ppm or less. Here, the solid content refers to all components excluding the solvent.

  Methods for measuring the ionic impurity content (ion concentration) in the resin include ICP emission analysis, IPC-MS analysis combining ICP with mass spectrometry, and ion chromatography using ion exchange resin as a filler. Examples of the method for measuring the ion concentration in the solid content in the silicone fine particles and the silicone resin composition in the present invention include a method by ion chromatography using an ion exchange resin as a column filler. In the case of silicone fine particles, a sample obtained by extracting the fine particles themselves with ultrapure water is analyzed by ion chromatography. In the case of a silicone resin composition, in the case of a liquid, the cured product is pulverized, and in the case of containing a solvent, the cured product obtained by drying and removing the solvent is pulverized and extracted with ultrapure water. Analyze by chromatography. For extraction with ultrapure water, 0.2 g of the above-mentioned silicone fine particles and the above pulverized material were collected, added with 20 ml of ultrapure water, shaken with a shaker for 15 minutes, and then membrane filter (PVDF pore size 0.45 μm, manufactured by Merck) ) And a solid phase extraction cartridge (InertSep Slim-J PLS-3 manufactured by GL Sciences Inc.).

  As a method for removing ionic impurities, specifically, impurities derived from the polymerization step are removed by washing after polymerization. Fine particles separated from the polymerization solution by centrifugation or filtration are again washed with water, and again separated from the washing water by centrifugation and filtration. Further, washing with water and separation are repeated until the concentration becomes less than the desired ionic impurity concentration. The upper limit of the ionic impurities contained in the silicone fine particles themselves is determined in consideration of the concentration at which the silicone fine particles are dispersed in the silicone resin. However, considering the amount of ionic impurities originally contained in the silicone resin, the silicone resin The upper limit value of the ionic impurities in the composition is preferably about the same.

  The phosphor used by mixing with the resin composition of the present invention absorbs light emitted from the LED chip, converts the wavelength, and emits light having a wavelength different from that of the LED chip. Thereby, a part of the light emitted from the LED chip and a part of the light emitted from the phosphor are mixed to obtain a multicolor LED including white. Specifically, a white LED can be emitted using a single LED chip by optically combining a blue LED with a phosphor that emits a yellow emission color by light from the LED.

  The phosphors as described above include various phosphors such as a phosphor that emits green light, a phosphor that emits blue light, a phosphor that emits yellow light, and a phosphor that emits red light. Specific phosphors used in the present invention include known phosphors such as inorganic phosphors, organic phosphors, fluorescent pigments, and fluorescent dyes. Examples of organic phosphors include allylsulfoamide / melamine formaldehyde co-condensed dyes and perylene phosphors. Perylene phosphors are preferably used because they can be used for a long period of time. Examples of the fluorescent material that is particularly preferably used in the present invention include inorganic phosphors. The inorganic phosphor used in the present invention is described below.

Examples of phosphors that emit green light include SrAl ₂ O ₄ : Eu, Y ₂ SiO ₅ : Ce, Tb, MgAl ₁₁ O ₁₉ : Ce, Tb, Sr ₇ Al ₁₂ O ₂₅ : Eu, (Mg, Ca, Sr , At least one of Ba) and Ga ₂ S ₄ : Eu.

Examples of phosphors that emit blue light include Sr ₅ (PO ₄ ) ₃ Cl: Eu, (SrCaBa) ₅ (PO ₄ ) ₃ Cl: Eu, (BaCa) ₅ (PO ₄ ) ₃ Cl: Eu, (Mg, ₂ B ₅ O ₉ Cl: Eu, Mn, (Mg, Ca, Sr, Ba, at least one) (PO ₄ ) ₆ Cl ₂ : Eu, Mn, etc. .

As phosphors emitting green to yellow, at least cerium-activated yttrium / aluminum oxide phosphors, at least cerium-enriched yttrium / gadolinium / aluminum oxide phosphors, at least cerium-activated yttrium / aluminum There are garnet oxide phosphors and at least cerium activated yttrium gallium aluminum oxide phosphors (so-called YAG phosphors). Specifically, Ln ₃ M ₅ O ₁₂ : R (Ln is at least one selected from Y, Gd, and La. M includes at least one of Al and Ca. R is a lanthanoid series. in _{a), (Y 1-x Ga} x) 3 (Al 1-y Ga y) 5 O 12:. R (R is, Ce, Tb, Pr, Sm , Eu, Dy, at least 1 or more selected from Ho 0 <Rx <0.5, 0 <y <0.5) can be used.

Examples of phosphors that emit red light include Y ₂ O ₂ S: Eu, La ₂ O ₂ S: Eu, Y ₂ O ₃ : Eu, and Gd ₂ O ₂ S: Eu.

As the phosphor corresponding to the current mainstream of the blue LED _{emission, Y 3 (Al, Ga)} 5 O 12: Ce, (Y, Gd) 3 Al 5 O 12: Ce, Lu 3 Al 5 O 12: Ce, Y ₃ Al ₅ O ₁₂ : YAG phosphor such as Ce, TAG phosphor such as Tb ₃ Al ₅ O ₁₂ : Ce, (Ba, Sr) ₂ SiO ₄ : Eu phosphor and Ca ₃ Sc ₂ Si ₃ O ₁₂ : Ce phosphor, silicate phosphor such as (Sr, Ba, Mg) ₂ SiO ₄ : Eu, (Ca, Sr) ₂ Si ₅ N ₈ : Eu, (Ca, Sr) AlSiN ₃ : Eu, CaSiAlN ₃ : Nitride phosphor such as Eu, Cax (Si, Al) ₁₂ (O, N) ₁₆ : Oxynitride phosphor such as Eu, and (Ba, Sr, Ca) Si ₂ O ₂ N ₂ : E Examples include phosphors such as u-based phosphors, Ca ₈ MgSi ₄ O ₁₆ Cl ₂ : Eu-based phosphors, SrAl ₂ O ₄ : Eu, and Sr ₄ Al ₁₄ O ₂₅ : Eu.

  Among these, YAG-based phosphors, TAG-based phosphors, and silicate-based phosphors are preferably used in terms of light emission efficiency and luminance.

  In addition to the above, known phosphors can be used according to the intended use and the intended emission color.

  The average particle diameter of the phosphor is not particularly limited, but those having a D50 of 1 μm or more are preferable. Further, those having D50 of 20 μm or less are preferable. Here, D50 is synonymous with that in the silicone fine particles, and is determined by the same measurement method. When D50 is in the above range, the dispersibility of the phosphor in the resin composition is good, and stable light emission can be obtained.

  In this invention, it is preferable that content of fluorescent substance is 0.5-200 weight part with respect to 100 weight part of silicone resin compositions, and it is more preferable that it is 3-20 weight part. When the phosphor content is 0.5 parts by weight or more, the emission wavelength is sufficiently converted, and when it is 200 parts by weight or less, the light transmittance can be maintained.

  As other components, it is preferable to blend a hydrosilylation reaction retarder such as acetylene alcohol in order to suppress curing at room temperature and lengthen the pot life. In addition, as long as the effect of the present invention is not impaired, fine particles such as fumed silica, glass powder, quartz powder, etc., inorganic fillers and pigments such as titanium oxide, zirconia oxide, barium titanate, zinc oxide, You may mix | blend adhesiveness imparting agents, such as a flame retardant, a heat resistant agent, antioxidant, a dispersing agent, a solvent, a silane coupling agent, and a titanium coupling agent.

  In particular, from the viewpoint of the surface smoothness of the cured product, it is preferable to add a low molecular weight polydimethylsiloxane component, silicone oil, or the like. The amount of such components added is preferably 100 to 2000 ppm, more preferably 500 to 1000 ppm, based on the total composition.

  Below, the manufacturing method of the silicone composition of this invention and the manufacturing method of a light emitting diode using the same are demonstrated. In addition, the following manufacturing methods are illustrations and are not limited to these.

  The silicone resin composition of the present invention can be obtained by mixing the silicone resin and silicone fine particles. As a mixing method, it can be produced by homogeneously mixing and dispersing with a stirrer / kneader such as a homogenizer, a self-revolving stirrer, three rollers, a ball mill, a planetary ball mill, or a bead mill. Defoaming by vacuum or reduced pressure is also preferably performed after mixing / dispersing or in the course of mixing / dispersing.

  The viscosity of the composition is appropriately adjusted depending on the ratio of the constituent components, the addition of a solvent, and the like. The viscosity at 25 ° C. measured with a rotational viscometer is 100 to 10,000,000 mPa · s, particularly 300 to 500,000 mPa. -It is preferable that it is s.

  A phosphor-dispersed silicone resin composition is obtained by dispersing the phosphor in the silicone resin composition thus obtained. The phosphor may be dispersed simultaneously with the dispersion of the silicone fine particles, or only the phosphor may be dispersed later in the silicone fine particle-dispersed silicone resin composition. Regarding the dispersion stability of the phosphor in the silicone resin encapsulant, the method of measuring the state and speed of the phosphor in the phosphor-dispersed silicone composition by visual observation or using an analytical instrument, the difference in particle size distribution, A method for measuring change is used. Specifically, the dispersion stability analyzer “LUMiSizer” (manufactured by LUM, Germany) is evaluated by a method of optically directly measuring the dispersion phenomenon due to centrifugal separation, particle size measurement using a particle gauge, etc. it can.

  The phosphor-dispersed silicone resin composition thus obtained is injection molded, compression molded, cast molded, transfer molded, extrusion molded, blow molded, calendar molded, vacuum molded, foam molded, coated, dispensed onto an LED chip. After printing, transferring, and curing, a phosphor dispersion having a desired shape can be placed on the LED chip. The curing conditions for heat curing are usually 40 to 250 ° C. for 1 minute to 5 hours, preferably 100 ° C. to 200 ° C. for 5 minutes to 2 hours. Thus, a light emitting diode (LED) provided with a cured product of the silicone resin composition is obtained. Although this hardened | cured material may be installed only on an LED chip, you may install also on a side surface. It is preferable to be provided in the light extraction part of the LED chip. Thereafter, the silicone resin composition of the present invention may be sealed with a transparent silicone resin that does not contain a phosphor, or by a method such as covering not only the LED chip but also the peripheral portion with a cured product of the silicone resin composition. The object itself may be used as a sealant.

  From the preparation of the phosphor-dispersed silicone resin composition to the curing, it is necessary to consider the residence time in the various processing processes described above, the heating time, etc. It is necessary to stabilize the dispersion for several hours to several tens of hours and to suppress the sedimentation of the phosphor.

  Since the cured silicone obtained as described above is used in optical applications such as sealing LED chips, it is preferable that the transmittance is higher. A preferred composition can be selected by comparing the transmittance of a silicone composition not containing a phosphor. Specifically, when a cured product (150 μm thickness) is obtained from a corn resin composition that does not contain the phosphor of the present invention and contains silicone fine particles, the transmittance at 400 nm of the cured product is 70% or more. Is more preferable and 80% or more is more preferable.

  FIG. 1 shows an example of an embodiment of a semiconductor light emitting device including a light emitting diode according to the present invention. The LED chip 1 is fixed to the concave portion of the package 4 with a die bonding material 2, and is joined to an electrode (not shown) on the package by a conductive wire 3. The concave portion of the package 4 is filled with a cured product obtained by mixing phosphor particles 6 with a silicone resin composition including the silicone resin 5 and the silicone fine particles 7 according to the present invention. The light emitted from the LED chip 1 is wavelength-converted by the phosphor particles 6 to obtain a light emitting device that emits a desired wavelength. According to the silicone resin composition of the present invention, dispersion in the silicone resin composition is improved, and a uniform phosphor content silicone resin composition can be supplied to each light emitting device. The variation in the color can be reduced.

  FIG. 2 shows another example of the embodiment of the semiconductor light emitting device including the light emitting diode according to the present invention. The LED chip 1 is fixed to the concave portion of the package 4 by a die bonding material 2 and is bonded to an electrode (not shown) on the package by a conductive wire 3. On the upper surface (light extraction surface) of the LED chip 1, a cured product obtained by mixing the phosphor particles 6 with the silicone resin composition containing the silicone resin 5 and the silicone fine particles 7 according to the present invention is laminated. Is filled with a transparent silicone sealing resin 8. This silicone sealing resin 8 may be the same as or different from the silicone resin 5 constituting the cured silicone product of the present invention. The light emitted from the LED chip 1 is wavelength-converted by the phosphor particles 6 as in the example of FIG. 1 to obtain a light emitting device that emits a desired wavelength. According to the silicone resin composition of the present invention, the phosphor dispersion uniformity in the silicone resin composition laminated on the upper surface of the LED chip is improved, and the amount of phosphor laminated on the LED chip in each light emitting device is made constant. Therefore, color variation among the light emitting devices can be reduced.

  Hereinafter, the present invention will be specifically described by way of examples. However, the present invention is not limited to these. The raw materials used in the silicone compositions in the examples and comparative examples, and the evaluation methods in the examples and comparative examples are as follows.

(A) Silicone resin Silicone resin 1: OE6630A / B (manufactured by Toray Dow Corning Co., Ltd.)
Addition-curing type phenyl silicone resin Refractive index 1.53.

(B) Fine particles (B-1) Silicone fine particles Silicone fine particles were produced by the method described in the following production examples.

(Production example)
Particles 1: 1 A four-necked round bottom flask equipped with a stirrer, thermometer, reflux tube and dropping funnel, and 600 g of caustic soda aqueous solution with pH 12.5 (25 ° C.) were placed in the flask and stirred at 300 rpm in an oil bath. The temperature rose. When the internal temperature reached 50 ° C., 60 g of a mixture of methyltrimethoxysilane and phenyltrimethoxysilane (23/77 mol%) was dropped from the dropping funnel over 20 minutes. Stirring was continued for 30 minutes at the same temperature, and then 16.5 g of 10% aqueous acetic acid solution was added as a neutralizing agent, mixed with stirring, and then filtered. 300 ml of water was added to the produced particles on the filter and mixed and stirred. After stirring for 10 minutes, the washing operation of filtering the mixed solution was repeated 10 times. Finally, 300 ml of methanol was mixed and stirred with the obtained particles, filtered in the same manner, and the filtrate was dried at 150 ° C. for 2 hours to obtain an average particle size (D50) of 1.0 μm and a refractive index of 1.54. 14 g of monodispersed spherical fine particles were obtained. Table 1 shows the results of measurement of residual ion components by analysis by ion chromatography.

  Particle 2: A stirrer, thermometer, reflux tube, and dropping funnel were attached to a 1 liter four-necked round bottom flask, and 600 g of caustic soda aqueous solution having a pH of 12.5 (25 ° C.) was added to the flask. The temperature rose. When the internal temperature reached 50 ° C., 60 g of a mixture of methyltrimethoxysilane and phenyltrimethoxysilane (23/77 mol%) was dropped from the dropping funnel over 20 minutes. Stirring was continued for 30 minutes at the same temperature, and then 16.5 g of 10% aqueous acetic acid solution was added as a neutralizing agent, mixed with stirring, and then filtered. 300 ml of water and 200 ml of methanol were added to the produced particles on the filter three times, followed by filtration and washing. The cake on the filter was taken out and dried at 150 ° C. for 2 hours to obtain 14 g of monodispersed spherical fine particles having an average particle diameter (D50) of 1.0 μm and a refractive index of 1.54. Table 1 shows the results of measurement of residual ion components by analysis by ion chromatography.

  Particle 3: A stirrer, thermometer, reflux tube, and dropping funnel were attached to a 1 liter four-necked round bottom flask, and 600 g of a caustic soda aqueous solution having a pH of 12.5 (25 ° C.) was placed in the flask. The temperature rose. When the internal temperature reached 50 ° C., 60 g of a mixture of methyltrimethoxysilane and phenyltrimethoxysilane (23/77 mol%) was dropped from the dropping funnel over 20 minutes. Stirring was continued for 30 minutes at the same temperature, and then 16.5 g of 10% aqueous acetic acid solution was added as a neutralizing agent, mixed with stirring, and then filtered. 300 ml of methanol was added to the produced particles on the filter once, followed by filtration and washing. The cake on the filter was taken out and dried at 150 ° C. for 2 hours to obtain 14 g of monodispersed spherical fine particles having an average particle diameter (D50) of 1.0 μm and a refractive index of 1.54. Table 1 shows the results of measurement of residual ion components by analysis by ion chromatography.

  Particle 4: A stirrer, thermometer, reflux tube, and dropping funnel are attached to a 1 l four-necked round bottom flask, and 600 g of a caustic soda aqueous solution having a pH of 12.5 (25 ° C.) is placed in the flask and stirred at 300 rpm in an oil bath. The temperature rose. When the internal temperature reached 50 ° C., 60 g of a mixture of methyltrimethoxysilane and phenyltrimethoxysilane (23/77 mol%) was dropped from the dropping funnel over 20 minutes. Stirring was continued for 30 minutes at the same temperature, and then a 10% ammonium chloride solution was added and mixed by stirring to precipitate the particles, followed by filtration. 300 ml of water was added to the produced particles on the filter and mixed and stirred. After stirring for 10 minutes, the washing operation of filtering the mixed solution was repeated 10 times. Finally, 300 ml of methanol was mixed and stirred with the obtained particles, filtered in the same manner, and the filtrate was dried at 150 ° C. for 2 hours to obtain an average particle size (D50) of 1.0 μm and a refractive index of 1.54. 14 g of monodispersed spherical fine particles were obtained. Table 1 shows the results of measurement of residual ion components by analysis by ion chromatography.

  Particle 5: A stirrer, thermometer, reflux tube and dropping funnel were attached to a 4-liter round-necked flask with 1 l, and 600 g of caustic soda aqueous solution with pH 12.5 (25 ° C.) was placed in the flask. The temperature rose. When the internal temperature reached 50 ° C., 60 g of a mixture of methyltrimethoxysilane and phenyltrimethoxysilane (23/77 mol%) was dropped from the dropping funnel over 20 minutes. Stirring was further continued for 30 minutes, and then a 10% ammonium chloride solution was added and mixed by stirring to precipitate the particles, followed by filtration. 300 ml of water and 200 ml of methanol were added to the produced particles on the filter three times, followed by filtration and washing. The cake on the filter was taken out and dried at 150 ° C. for 2 hours to obtain 14 g of monodispersed spherical fine particles having an average particle diameter (D50) of 1.0 μm and a refractive index of 1.54. Table 1 shows the results of measurement of residual ion components by analysis by ion chromatography.

  Particle 6: A stirrer, thermometer, reflux tube and dropping funnel were attached to a 4-liter round-bottom flask, and 600 g of caustic soda aqueous solution having a pH of 12.5 (25 ° C.) was placed in the flask. The temperature rose. When the internal temperature reached 50 ° C., 60 g of a mixture of methyltrimethoxysilane and phenyltrimethoxysilane (23/77 mol%) was dropped from the dropping funnel over 20 minutes. Stirring was further continued for 30 minutes, and then a 10% ammonium chloride solution was added and mixed by stirring to precipitate the particles, followed by filtration. 300 ml of methanol was added to the produced particles on the filter once, followed by filtration and washing. The cake on the filter was taken out and dried at 150 ° C. for 2 hours to obtain 14 g of monodispersed spherical fine particles having an average particle diameter (D50) of 1.0 μm and a refractive index of 1.54. Table 1 shows the results of measurement of residual ion components by analysis by ion chromatography.

(B-2) Inorganic fine particles “Aerosil” 200 (manufactured by Nippon Aerosil Co., Ltd.) Specific surface area 200 m ² / g Silica fine particles Refractive index 1.41.

(C) Phosphor NYAG-02 (manufactured by Intematix) Ce-doped YAG phosphor. Specific gravity: 4.8 g / cm ³ , D50: 7 μm.

<Method for producing silicone composition and cured product>
The silicone composition and cured product of each Example and Comparative Example were prepared as follows. A predetermined amount of (A) silicone resin and (B) fine particles shown in Table 2 were weighed in a polyethylene container having a capacity of 300 ml, and stirred and mixed with a homogenizer. Table 2 shows ion concentrations in the silicone resin composition obtained by mixing.

  Next, 10 parts by weight of (C) phosphor is added to each silicone composition with respect to 100 parts by weight of the total amount of silicone resin and fine particles, and a planetary stirring and defoaming device “Mazerustar KK-400” (manufactured by Kurabo Industries) is installed. A phosphor-containing silicone resin composition was prepared by stirring and defoaming at 1000 rpm for 20 minutes.

<Ion concentration measurement method (ion chromatography)>
In the case of silicone fine particles or silicone resin composition, 0.2 g of pulverized cured product is collected, added with 20 ml of ultrapure water, shaken with a shaker for 15 minutes, and then membrane filter (PVDF pore size 0.45 μm Merck) And a solution treated with a cartridge for solid phase extraction (InertSep Slim-J PLS-3 manufactured by GL Sciences Inc.) was analyzed by ion chromatography.
Measurement conditions Anion device ICS-3000 made by Dionex
Sample injection volume 100μL
Eluent KOH Gradient Separation Column 2mmΦ × 250mm Ion Pac AS23
Detector Electrical conductivity meter Cation device Dionex DX-500
Sample injection volume 100μL
Eluent 10 mM methanesulfonic acid separation column 2 mmΦ × 250 mm Ion Pac CS14
Detector Electric conductivity meter.

<Transmittance measurement>
For the silicone resin composition shown in Table 2, film formation and heat curing were performed on a glass substrate so that the film thickness after curing was 150 μm, and “MultiSpec 1500” manufactured by Shimadzu Corporation was used as a reference for the glass substrate at 400 nm. The transmittance of the cured product was measured. The transmittance of each cured product is shown in Table 2.

<Light-emitting device evaluation>
A blue light emitting LED having an emission wavelength of 430 nm is used, and the inside of the package opening shown in FIG. 1 is sealed with a phosphor-containing silicone resin composition, which is then heated at 100 ° C. for 1 hour and further at 160 ° C. for 1 hour. A semiconductor light emitting device was obtained by heat treatment. In encapsulating the resin, 1000 packages were successively prepared for each silicone composition, and the initial 10 color variations and the 10 final color variations were compared and evaluated. In order to evaluate the color variation of the light emitting device, chromaticity was measured using LP3400 manufactured by Otsuka Electronics.

Examples 1-4, Comparative Examples 1-4
A silicone composition was prepared as described above, and the light emitting device was evaluated. The results are shown in Tables 3-4. From the comparison between Comparative Example 4 and other examples, when sealing with a silicone resin composition containing silicone fine particles, it is possible to suppress color variation more than when sealing with a silicone resin composition not containing silicone fine particles. I knew it was possible. In addition, in comparison with Examples 1 to 4 and Comparative Examples 1 and 2, with respect to acetate ions, chloride ions, ammonium ions and alkali metal ions, in a resin sealing process over a long period of time in which ion impurities are not reduced It was found that the variation gradually increased. Further, from Comparative Example 3, when inorganic fine particles are used instead of silicone fine particles, the ionic impurities are small and the variation is small over a long period of time. However, since the refractive index is not matched with the silicone resin, the transmittance is low, so the luminance is low. It turns out that it falls.

DESCRIPTION OF SYMBOLS 1 LED chip 2 Dun bonding material 3 Conductive wire 4 Package 5 Silicone resin 6 Phosphor particle 7 Silicone fine particle 8 Silicone sealing resin

Claims (5)

A silicone resin composition comprising a silicone resin and silicone fine particles, wherein the concentration of acetate ions, chloride ions, ammonium ions and alkali metal ions in the solid content is 5 ppm or less. Furthermore, the silicone resin composition of Claim 1 containing fluorescent substance. A cured silicone resin obtained by curing the silicone resin composition according to claim 1. The light emitting diode provided with the hardened | cured material of the silicone resin composition of Claim 1 or 2. A semiconductor light-emitting device comprising the light-emitting diode according to claim 4.

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