JP2019040978A - Method for deciding physical quantity of metal oxide particles in light-emitting device - Google Patents

Abstract

To provide a method for deciding a physical quantity of metal oxide particles in a light-emitting device, by which a light extraction efficiency can be increased.SOLUTION: Provided is a method for deciding a physical quantity of metal oxide particles in a light-emitting device including a substrate having a concave portion, a light-emitting element disposed on a bottom face of the concave portion, and a transparent sealing member disposed over the concave portion and sealing the light-emitting element, wherein the transparent sealing member includes a resin and metal oxide particles dispersed in the resin and having a refraction index of 1.7 or more. The method comprises: a first step of supposing that the physical quantity of the metal oxide particles is changed, and estimating a radiant quantity or luminous quantity of light radiated from the light-emitting device in a range of the supposed physical quantity change of the metal oxide particles; and a second step of deciding the physical quantity of the metal oxide particles based on the estimated radiant quantity or luminous quantity.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for determining a physical quantity of metal oxide particles in a light emitting device.

  Light emitting diodes (LEDs) are widely used as light sources having advantages such as small size, long life, and low voltage driving. In general, an LED chip in an LED package is sealed with a sealing material including a resin in order to prevent contact with deterioration factors existing in an external environment such as oxygen and moisture. Therefore, the light emitted from the LED chip is emitted toward the outside through the sealing material. Therefore, in order to increase the luminous flux emitted from the LED package, it is important to efficiently extract the light emitted from the LED chip to the outside of the LED package.

  As a sealing material for improving the extraction efficiency of light emitted from the LED chip, inorganic oxide particles having a dispersed particle diameter of 1 nm or more and 20 nm or less and a refractive index of 1.8 or more, a silicone resin, The composition formed by containing is proposed (patent document 1).

  In this composition, a dispersion containing metal oxide particles having a small dispersed particle size and a high refractive index is mixed with a silicone resin. Therefore, the inorganic oxide particles in the composition can improve the refractive index of the sealing material, and when the light emitted from the LED chip enters the sealing material, at the interface between the LED chip and the sealing material. Total reflection of light can be suppressed. Moreover, since the dispersion | distribution particle size of an inorganic oxide particle is small, the fall of the transparency of sealing material is suppressed. As a result, the light extraction efficiency can be improved.

JP 2007-299981 A

  However, in order to further increase the luminous flux emitted from a light emitting device such as an LED package, further improvement in light extraction efficiency has been demanded.

  The present invention has been made to solve the above-described problems, and provides a method for determining a physical quantity of metal oxide particles in a light-emitting device, which can improve the light extraction efficiency of the light-emitting device. Objective.

In order to solve the above problems, according to an aspect of the present invention, a substrate having a recess, a light emitting element disposed on a bottom surface of the recess, a transparent seal disposed in the recess and sealing the light emitting element. A method of determining a physical quantity of the metal oxide particles in the light emitting device, the transparent sealing member including a resin and metal oxide particles having a refractive index of 1.7 or more dispersed in the resin. Because
Assuming that the physical quantity of the metal oxide particles is changed, a first estimation of the radiation amount or photometric quantity of the light emitted from the light emitting device within the assumed range of change of the physical quantity of the metal oxide particles is performed. And the process of
A second step of determining a physical quantity of the metal oxide particles based on the estimated radiation amount or the photometric quantity;
A method for determining a physical quantity of metal oxide particles in a light emitting device is provided.

The transparent sealing member further includes phosphor particles,
Assuming the case where the physical quantity of the metal oxide particles and the physical quantity of the phosphor particles are changed in the first step, the range of the assumed physical quantity of the metal oxide particles and the change in the physical quantity of the phosphor particles is assumed. The amount of radiation or the amount of light measured from the light emitting device may be estimated.

  As mentioned above, according to this invention, the determination method of the physical quantity of the metal oxide particle in the light-emitting device which can improve the light extraction efficiency of a light-emitting device can be provided.

It is typical sectional drawing of the light-emitting device which concerns on 1st Embodiment of this invention. It is typical sectional drawing which shows the modification of the light-emitting device which concerns on 1st Embodiment of this invention. It is a typical longitudinal cross-sectional view of the light-emitting device which concerns on 2nd Embodiment of this invention. It is typical width direction sectional drawing of the light-emitting device which concerns on 2nd Embodiment of this invention. It is a typical longitudinal direction sectional view showing the modification of the light emitting device concerning a 1st embodiment of the present invention. It is typical width direction sectional drawing which shows the modification of the light-emitting device which concerns on 1st Embodiment of this invention. These are the spectrum of the light emitting element, the absorption spectrum of the phosphor particles, the excitation spectrum of the phosphor, and the emission spectrum of the phosphor assumed in the ray tracing simulation. It is the particle size distribution of the phosphor particles assumed in the ray tracing simulation. It is a ray tracing result in case the content of zirconium oxide in simulation 1 is 0% by mass. It is a ray tracing result in case the content of zirconium oxide in simulation 1 is 0.6 mass%. It is a graph which shows the relationship between the zirconium oxide content in the simulation 1, and the estimated total luminous flux (lm) and radiant flux (W) of the light emitting device. It is a graph which shows the relationship between the zirconium oxide content in the simulation 2, and the total luminous flux (lm) of the estimated light-emitting device. It is a graph which shows the relationship between the zirconium oxide content in the simulation 2, and the radiant flux (W) of the estimated light-emitting device. It is a graph which shows the relationship between the increase rate of the total luminous flux (lm) of the light-emitting device estimated in the simulation 2 and the zirconium oxide content. It is a graph which shows the relationship between the zirconium oxide content in the simulation 2, and the raise rate of the radiant flux (W) of the estimated light-emitting device. It is a graph which shows the relationship between the volume concentration (volume%) of the fluorescent substance particle required in order to adjust the chromaticity of the light discharge | released from the light-emitting device in simulation 2 to a white point, and zirconium oxide content. It is a graph which shows the relationship between the zirconium oxide content in the simulation 3, and the total luminous flux (lm) of the estimated light-emitting device. It is a graph which shows the relationship between the zirconium oxide content in the simulation 3, and the radiant flux (W) of the estimated light-emitting device. It is a graph which shows the relationship between the volume density | concentration (volume%) of the phosphor particle required in order to adjust the chromaticity of the light discharge | released from the light-emitting device in the simulation 3 to a white point, and zirconium oxide content. It is a graph which shows the relationship between the zirconium oxide content in the simulation 4, and the total luminous flux (lm) of the estimated light-emitting device. It is a graph which shows the relationship between the zirconium oxide content in the simulation 4, and the radiant flux (W) of the estimated light-emitting device. It is a graph which shows the relationship between the volume concentration (volume%) of a fluorescent substance particle required in order to adjust the chromaticity of the light discharge | released from the light-emitting device in the simulation 4 to a white point, and zirconium oxide content.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

  In the present specification and drawings, similar constituent elements of different embodiments are distinguished by attaching different alphabets after the same reference numerals. However, when there is no need to particularly distinguish each of a plurality of constituent elements having substantially the same functional configuration, only the same reference numerals are given. In the drawing, members that do not need to be described are omitted for the sake of simplicity. In addition, the dimensions of the illustrated members are appropriately enlarged and reduced for ease of explanation, and do not indicate actual sizes of the respective members.

<1. Light emitting device>
(1.1) First Embodiment First, a light emitting device according to a first embodiment of the invention will be described. FIG. 1 is a schematic cross-sectional view of a light emitting device according to a first embodiment of the present invention. The light emitting device 1 shown in FIG. 1 is a so-called top-view surface mount type LED package. The light emitting device 1 mainly includes a substrate 10 having a recess 11, a light emitting element 20 disposed on the bottom surface 15 of the recess 11, and a transparent sealing member 30 disposed in the recess 11 and sealing the light emitting element 20. .

The substrate 10 is a casing of the light emitting device 1 and carries and stores each member of the light emitting device 1. The substrate 10 has a recess 11. Recess 11 is a cavity having a depth D _1, the cross-section as shown in FIG. 1 is formed by the wall surface 13 which intersects the bottom surface disposed on the periphery of the bottom surface 15 and bottom surface 15, in a plan view The bottom 15 is square (not shown). Note that the shape of the substrate is not limited to the above-described mode, and the bottom portion may be a shape in which each corner of the square is curved (having R) or a circle.

Moreover, the recessed part 11 is opened toward the opening part 17 from the bottom face 15 so that the wall surface 13 which opposes makes the predetermined angle (alpha). As a result, the width W _{B1 of the} bottom surface 15 is usually smaller than the width W _T1 of the opening 17. The angle α, the width W _B1 , the width W _T1 and the depth D ₁ are not particularly limited. For example, the angle α is appropriately selected within a range of 0 ° (vertical) to 165 °.

  The substrate 10 is made of a resin material such as polypropylene, polyamide, or glass epoxy. In addition, in order to make the wall surface 13 of the board | substrate 10 into the reflector which reflects the light ray from the light emitting element 20, a white pigment etc. can also be included in a resin material, for example. The material configuration of the substrate 10 is not limited to the above, and a known material can be appropriately selected and used.

  The light-emitting element 20 is a light-emitting diode (LED) that can emit light when voltage is applied, and is composed of a compound semiconductor such as GaAs, GaP, AlGaInP, or InGaN. The light emitting element 20 is disposed on the bottom surface 15 of the recess 11. More specifically, the light emitting element 20 is disposed on a lead frame 50 made of a metal such as silver plating embedded in the vicinity of the bottom surface 15 of the substrate 10. Two bonding wires 40 made of metal such as gold connect the light emitting element 20 and the lead frame 50. The light emitting element 20 emits light when a voltage is applied from the lead frame 50 through the bonding wire 40.

  In the present embodiment, the light emitting element 20 can emit blue light having a peak wavelength of, for example, 440 nm or more and 475 nm or less. In addition, the light emission wavelength of the light emitting element 20 is not limited to the above, and can be appropriately selected according to the application.

  The transparent sealing member 30 is disposed in the recess 11 and seals the light emitting element 20, thereby preventing contact between the light emitting element 20 and deterioration factors existing in the external environment such as oxygen and moisture. Further, the transparent sealing member 30 protects each component member on the substrate 10 such as the light emitting element 20, the bonding wire 40, and the lead frame 50 from an impact. Further, the transparent sealing member 30 can transmit the light emitted from the light emitting element 20 and can be emitted outside the light emitting device 1. The transparent sealing member 30 includes a resin and metal oxide particles having a refractive index of 1.7 or more.

The resin is not particularly limited as long as it can be used as a sealing material. For example, a resin such as a silicone resin or an epoxy resin can be used. In particular, a silicone resin is preferable.
The silicone resin is not particularly limited as long as it is used as a sealing material, and for example, dimethyl silicone resin, methylphenyl silicone resin, phenyl silicone resin, organically modified silicone resin and the like can be used.

  The structure of the resin is not particularly limited, and may be a two-dimensional chain structure, a three-dimensional network structure, or a cage structure.

The metal oxide particles have a refractive index of 1.7 or more, and improve the refractive index of the sealing member. The metal oxide particles are used for light scattering in the sealing member as will be described later.

  The metal oxide particles used in the present embodiment have a refractive index of 1.7 or more. The refractive index of such metal oxide particles is preferably 1.8 or more, more preferably 1.9 or more, and even more preferably 2 from the viewpoint of improving the refractive index of the sealing member and improving the light scattering effect. 0.0 or more.

  Examples of the metal oxide particles containing one metal element and having a refractive index of 1.7 or more include zirconium oxide particles, titanium oxide particles, zinc oxide particles, iron oxide particles, aluminum oxide particles, copper oxide particles, and tin oxide. Particles, yttrium oxide particles, cerium oxide particles, tantalum oxide particles, niobium oxide particles, molybdenum oxide particles, indium oxide particles, antimony oxide particles, germanium oxide particles, lead oxide particles, bismuth oxide particles, tungsten oxide particles, europium oxide particles, And one or more selected from the group consisting of hafnium oxide particles are preferably used.

  Examples of the metal oxide particles containing two kinds of metal elements and having a refractive index of 1.7 or more include potassium titanate particles, barium titanate particles, strontium titanate particles, potassium niobate particles, lithium niobate particles, tungsten One or more selected from the group consisting of calcium acid particles, yttria-stabilized zirconium oxide particles, antimony-added tin oxide particles, and indium-added tin oxide particles are preferably used. Note that metal oxide particles containing three or more metal elements can also be used as long as the refractive index is 1.7 or more. Moreover, you may use suitably combining the metal oxide particle containing 1 type, 2 types, and 3 or more types of metal elements mentioned above.

  Among these metal oxide particles, in terms of obtaining a transparent sealing member 30 having a high refractive index and high transparency, the metal oxide particles are preferably zirconium oxide particles and / or titanium oxide particles, and more Zirconium oxide particles are preferred.

  Moreover, in this embodiment, the average dispersion particle diameter of a metal oxide particle is 40 nm or more and 200 nm or less. In the present embodiment, the reason why the average dispersed particle size of the metal oxide particles is 40 nm or more and 200 nm or less is as follows.

  Conventionally, in order to improve the light extraction efficiency, it has been considered that the transparency (transmittance) of a composition used as a sealing material is preferably higher. For this reason, it has been considered that the average dispersed particle size of the metal oxide particles in the transparent sealing member 30 is preferably as small as possible.

  However, the present inventors set the average dispersed particle size of the metal oxide particles in the transparent sealing member 30 to 40 nm or more and 200 nm or less, and scatter more light emitted from the light emitting element in the transparent sealing member 30 described later. As a result, it was found that the light extraction efficiency of the transparent sealing member 30 is improved even if the transparency of the transparent sealing member 30 itself is somewhat lowered.

  From the viewpoint of further improving the light extraction efficiency, the average dispersed particle size of the metal oxide particles is preferably 40 nm or more and 150 nm or less, and more preferably 45 nm or more and 130 nm or less.

When the average dispersed particle size is less than 40 nm, a sufficient light scattering effect cannot be obtained, and the light extraction efficiency is reduced, which is not preferable. On the other hand, when the average dispersed particle size exceeds 200 nm, the transmittance of the transparent sealing member 30 is too low, and the light extraction efficiency is reduced, which is not preferable.

  The average dispersed particle size of the metal oxide particles is the average particle size based on number distribution (median diameter, D50) measured by transmission electron microscope observation (TEM) of the transparent sealing member 30. Further, the average dispersed particle size of the metal oxide particles in the present embodiment is a value that is measured and calculated based on the dispersed particle size of the metal oxide particles in the transparent sealing member 30. The average dispersed particle diameter is measured and calculated based on the diameter of the metal oxide particles in a dispersed state regardless of whether the metal oxide particles are dispersed in a primary particle state or a secondary particle state. . Moreover, in this embodiment, D50 of a metal oxide particle may be measured as D50 of the metal oxide particle to which the surface modification material mentioned later adheres. In the transparent sealing member 30, metal oxide particles to which the surface modifying material is attached and metal oxide particles to which the surface modifying material is not attached may be present. It is measured as a value in these mixed states.

  The average primary particle diameter of the metal oxide particles is, for example, 3 nm to 20 nm, preferably 4 nm to 20 nm, more preferably 5 nm to 20 nm. When the average primary particle size is in the above range, the average dispersed particle size can be easily controlled to 40 nm or more and 200 nm or less.

As a method for measuring the average primary particle size, a predetermined number, for example, 100 metal oxide particles are selected. And the longest straight line part (maximum long diameter) of each of these metal oxide particles is measured, and these measured values are obtained by weighted averaging.
Here, when the metal oxide particles are aggregated, the aggregated particle diameter of the aggregate is not measured. A predetermined number of maximum long diameters of the metal oxide particle particles (primary particles) constituting the aggregate are measured to obtain an average primary particle diameter.

  The content of the metal oxide particles having a refractive index of 1.7 or more in the transparent sealing member 30 may be appropriately adjusted according to desired characteristics. The content of the metal oxide particles in the transparent sealing member 30 is preferably 0.2% by mass or more and 15.0% by mass or less, more preferably 1.0% by mass from the viewpoint of achieving both light scattering properties and transparency. % To 10.0% by mass, more preferably 3.0% to 7.0% by mass.

  In addition, the above description does not exclude that the transparent sealing member 30 contains metal oxide particles having a refractive index of less than 1.7. The transparent sealing member 30 may include metal oxide particles having a refractive index of less than 1.7 in addition to metal oxide particles having a refractive index of 1.7 or more depending on the purpose.

  Moreover, the transparent sealing member 30 may contain phosphor particles. The phosphor particles absorb light having a specific wavelength emitted from the light emitting element, and emit light having a predetermined wavelength. In other words, the phosphor particles can be used to convert the wavelength of light and thus adjust the color tone.

The phosphor particles are not particularly limited as long as they can be used in a general light emitting device, and can be appropriately selected and used so that the light emission color of the light emitting device 1 becomes a desired color. For example, when the light emitting element 20 emits blue light and the light emitting device 1 as a whole aims to extract white light, phosphor particles that absorb blue light and emit yellow fluorescence are transparently sealed. It can be included in the stop member 30.
The content of the phosphor particles in the transparent sealing member 30 can be appropriately adjusted and used so as to obtain a desired color tone and desired brightness.

  Moreover, the transparent sealing member 30 may include components other than those described above. Examples of such a component include a diffusing material such as silica particles.

  In FIG. 1, the transparent sealing member 30 is disposed so as to form a plane along the opening 17 of the substrate 10, but the shape of the transparent sealing member 30 is not limited to the illustrated mode. For example, the transparent sealing member 30 may have its upper surface disposed closer to the bottom surface 15 than the opening 17 of the substrate 10 or may protrude from the opening 17. Further, the upper surface of the transparent sealing member 30 may have a concave shape or a convex shape.

  According to the present embodiment described above, the metal oxide particles having an average dispersed particle diameter of 40 nm or more and 200 nm or less and a refractive index of 1.7 or more are dispersed in the transparent sealing member 30. The radiated light emitted from the light emitting element 20 is preferably scattered and the diffusion in the plane direction of the substrate 10 is suppressed. As a result, the light emitting device 1 is excellent in light extraction efficiency.

  Furthermore, when the transparent sealing member 30 includes phosphor particles, the probability that the emitted light is incident on the phosphor particles in the transparent sealing member 30 increases due to scattering of the emitted light by the metal oxide particles. For this reason, even when the amount of the phosphor particles is relatively small, it is possible to sufficiently extract light having a target color tone from the light emitting device 1. Moreover, the loss of energy at the time of wavelength conversion of the emitted light by the phosphor particles can be suppressed, and as a result, the light emission efficiency of the light emitting device 1 is improved. Furthermore, since the amount of phosphor particles can be reduced, the manufacturing cost of the light emitting device 1 can be relatively reduced.

  Note that the top-view light-emitting device 1 according to this embodiment described above can be variously modified. For example, the transparent sealing member may have a plurality of layers. An example of such a light emitting device is shown in FIG. FIG. 2 is a schematic cross-sectional view showing a modification of the light emitting device according to the first embodiment of the present invention. Hereinafter, differences between the light-emitting device 1 and the light-emitting device 1A illustrated in FIG. 2 will be described, and description of similar configurations will be omitted. Note that some members described in the light emitting device 1 are omitted in the following drawings for ease of description.

  In the light emitting device 1 </ b> A shown in FIG. 2, the configuration of the transparent sealing member 30 </ b> A is different from the configuration of the transparent sealing member 30 of the light emitting device 1. Specifically, the transparent sealing member 30A includes a first layer 31A containing phosphor particles and a second layer 33A disposed on the first layer 31A. Further, the metal oxide particles as described above are dispersed in both the first layer 31A and the second layer 33A. As described above, the light extraction efficiency of the light emitting device 1 </ b> A is improved by the same mechanism as that of the light emitting device 1.

  In addition, in this invention, the layer structure of a transparent sealing member is not limited to the aspect of illustration, For example, the transparent sealing member may have a 3 or more different layer. Moreover, the transparent sealing member does not need to contain a metal oxide particle in all the layers. For example, only a part of the transparent sealing member may contain metal oxide particles.

(1.2) Second Embodiment Next, a light emitting device according to a second embodiment of the present invention will be described. FIG. 3 is a schematic longitudinal sectional view of a light emitting device according to a second embodiment of the present invention, and FIG. 4 is a schematic widthwise sectional view of the light emitting device shown in FIG.

3 and 4 is a so-called side-view type surface mount LED package. In the light emitting device 1B, the concave portion 11B has a rectangular shape when the substrate 10B is viewed in plan, and the substrate 10B has a rectangular shape corresponding to this. Therefore, the length L _B3 of the bottom portion 15B is larger than the width W _B3 . Further, the length L _T3 of the opening 17B is larger than the width W _T3 . Note that the wall surface 13B opens from the bottom surface 15B toward the opening 17B at a predetermined angle in both the longitudinal direction and the width direction of the substrate 10B. Therefore, the length L _B3 and the width W _B3 of the bottom surface 15B are usually smaller than the length L _T3 and the width W _{T3 of} the opening 17B, respectively.

The light emitting element 20B is disposed on the lead frame 50B on the bottom 15B.
In addition, the transparent sealing member 30B includes a first layer 31B containing phosphor particles and a second layer 33B disposed on the first layer 31B. And the metal oxide particle explained in full detail in description of the transparent sealing member 30 is disperse | distributing to both the 1st layer 31B and the 2nd layer 33B.

  In the light emitting device 1B having the above-described configuration, the light extraction efficiency is improved as in the light emitting device 1.

  The side-view type light emitting device 1B according to the present embodiment described above can be variously modified. For example, the transparent sealing member may have a plurality of layers or may be composed of only one layer. Further, the light emitting device may include a plurality of light emitting elements. Examples of such modifications include light emitting devices as shown in FIGS. FIG. 5 is a schematic longitudinal sectional view showing a modification of the light emitting device according to the first embodiment of the present invention. FIG. 6 is a schematic view showing a modification of the light emitting device according to the first embodiment of the present invention. FIG.

The light emitting device 1C shown in FIGS. 5 and 6 is different from the light emitting device 1B in that two light emitting elements 20C are arranged along the longitudinal direction on the lead frame 50C on the bottom surface 15B of the recess 11B. It has the same configuration as the device 1B.
In the light emitting device 1 </ b> C having the above-described configuration, the light extraction efficiency is improved as in the light emitting device 1.

The light emitting device according to the preferred embodiment of the present invention has been described above. In addition, this invention is not limited to said embodiment. For example, each component in the first embodiment and the second embodiment can be appropriately replaced as much as possible. In the above description, the light emitting element is described as a light emitting diode. However, the present invention is not limited to this, and the light emitting element may be, for example, an organic light emitting diode (OLED).
In addition, the light emitting device according to the present invention may be manufactured by any method. For example, the light emitting device can be manufactured by a method of manufacturing a light emitting device described later.

<2. Lighting fixture and display device>
Next, the lighting fixture and display device according to the present embodiment will be described. The lighting fixture and the display device according to the present embodiment include the light emitting device according to the embodiment of the present invention described above.

Examples of lighting fixtures include general lighting devices such as room lights and outdoor lights, and illumination of switch units of electronic devices such as mobile phones and OA devices.
Since the lighting fixture according to the present embodiment includes the light emitting device according to the embodiment of the present invention as described above, even when the same light emitting element is used, the emitted light flux is increased compared to the conventional case, and the ambient environment is increased. Can be made brighter.

Examples of the display device include a mobile phone, a portable information terminal, an electronic dictionary, a digital camera, a computer, a television, and peripheral devices thereof.
Since the display device according to the present embodiment includes the light emitting device according to the embodiment of the present invention as described above, even when the same light emitting element is used, the emitted light flux becomes larger compared to the conventional case. A clear and high brightness display can be performed.

<3. Method for manufacturing light emitting device and method for determining physical quantity of metal oxide particles in light emitting device>
Next, a method for manufacturing a light-emitting device according to an embodiment of the present invention and a method for determining a physical quantity of metal oxide particles in the light-emitting device will be described.

The method for determining the physical quantity of the metal oxide particles in the light emitting device according to this embodiment is a method for determining the physical quantity of the metal oxide particles in the light emitting device as described above, and changes the physical quantity of the metal oxide particles. A first step of estimating a radiation amount or a photometric quantity of light emitted from the light emitting device in a range of change in the assumed physical quantity of the metal oxide particles, and the estimated radiation amount Or a second step of determining a physical quantity of the metal oxide particles based on the photometric quantity.
In addition to the first step and the second step described above, the method for manufacturing the light emitting device according to the present embodiment includes a third step of manufacturing the light emitting device based on the determined physical quantity.

  Hereinafter, each step will be described in detail. In the description of each step, the description will be made based on the light emitting device 1 shown in FIG. 1 as necessary. Needless to say, each method according to the present embodiment is not limited to the method for the light emitting device 1.

  First, in the first step, assuming that the physical quantity of the metal oxide particles is changed, the radiation amount of light emitted from the light emitting device 1 in the range of change of the assumed physical quantity of the metal oxide particles or Estimate the photometric quantity.

  The physical amount of the metal oxide particles is not particularly limited. For example, the average dispersed particle size, the average primary particle size, the concentration, the refractive index, and the position in the transparent sealing member 30 are unevenly distributed or uniformly dispersed. Or existing in some layers). Among the above, the physical quantity of the metal oxide particles preferably includes the average dispersed particle size and / or the concentration in the transparent sealing member 30. These physical quantities can have a relatively large influence on the light extraction efficiency of the light emitting device 1.

For example, the concentration of the metal oxide particles in the transparent sealing member 30 is changed in the range of, for example, 0.1% by mass or more and 15.0% by mass or less, preferably 3.0% by mass or more and 7.0% by mass or less. be able to. Such a low concentration range is a range in which the light transmittance of the transparent sealing member 30 is easily maintained.
The average dispersed particle size of the metal oxide particles can be changed, for example, in the range of 40 nm to 200 nm, preferably 40 nm to 150 nm, more preferably 45 nm to 130 nm.

  Further, when the transparent sealing member 30 includes phosphor particles, it is emitted from the light emitting device 1 on the assumption that in this step, the physical quantity of the phosphor particles is changed in addition to the physical quantity of the metal oxide particles. It is preferable to estimate the light emission amount or the photometric amount.

The physical quantity of the phosphor particles is not particularly limited, but the average dispersed particle size, the concentration in the transparent sealing member 30, the excitation wavelength, the absorption wavelength, the emission wavelength, the position (locally distributed or uniformly dispersed, Or the like in some layers).
The density | concentration in the transparent sealing member 30 of a fluorescent substance particle can be changed in the range of 0.01 mass% or more and 5 mass% or less, for example.

  In this step, examples of the radiation amount include radiant flux, radiant energy, irradiance, radiant divergence, radiant intensity, and radiance. In addition, examples of the photometric quantity include a light flux, a light quantity, an illuminance, a luminous flux divergence, a luminous intensity, and a luminance. Among those described above, when the light-emitting device 1 is used for display or illumination, it is preferable to estimate the photometric amount in consideration of the relative visual sensitivity of the human eye.

  In addition, the estimation of the radiation amount or the photometric quantity of the light emitted from the light emitting device 1 is performed by the information processing device assuming the configuration of the light emitting device 1 and the physical quantities of the metal oxide particles and the phosphor particles. This can be done by executing a ray tracing simulation of the light emitted from the element 20.

  As the information processing apparatus, for example, a known computer having a processing device (processor), a main storage device (main memory), an auxiliary storage device (external storage device), an input / output unit, and the like can be used.

  Next, in the second step, the physical quantity of the metal oxide particles is determined based on the estimated radiation amount or photometric quantity. For example, in this step, a physical quantity corresponding to a range within 5.0%, preferably within 10.0% from the maximum value of the radiation amount or the photometric quantity in the range of the estimated radiation quantity or the photometric quantity is selected. Thus, the physical quantity of the metal oxide particles can be determined. In addition, although the physical quantity of the metal oxide particle determined may be a value, it may have a certain range.

  In this step, the physical quantity of the phosphor particles may be determined in addition to the physical quantity of the metal oxide particles.

  Also in this process, using an information processing device, the relationship between the estimated radiant quantity or photometric quantity, the physical quantity of the metal oxide particles and the physical quantity of the phosphor particles is specified, and the physical quantity of the metal oxide particles used for production May be determined.

  Next, in the third step, the light emitting device 1 is manufactured based on the determined physical quantity of the metal oxide particles. In this step, the light-emitting device 1 can be manufactured using a known physical quantity of metal oxide particles using a known method.

  For example, the light emitting device 1 can be manufactured by disposing the light emitting element 20 on the previously formed substrate 10, forming the bonding wire 40, and sealing the light emitting element 20 with the transparent sealing member 30.

Here, the resin composition for forming the transparent sealing member 30 will be described.
The resin composition includes the metal oxide particles described above and a resin component, that is, a resin and / or a precursor thereof.

  The metal oxide particles are blended in the resin composition based on the physical quantities determined in the first step and the second step.

  The resin component is a main component in the resin composition. Such a resin component is not particularly limited as long as it can be used as a general sealing member. For example, a resin such as a silicone resin or an epoxy resin can be used. In particular, a silicone resin is preferable.

  It does not specifically limit as a silicone resin, For example, a dimethyl silicone resin, a methylphenyl silicone resin, a phenyl silicone resin, an organic modified silicone resin etc. can be used.

  In particular, the resin composition includes a surface modifying material described later, the surface modifying material has at least one functional group selected from the group of alkenyl groups, H-Si groups, and alkoxy groups, and silicone as a resin component. When a resin is used, the silicone resin preferably has at least one functional group selected from the group consisting of an H—Si group, an alkenyl group, and an alkoxy group. The reason will be described below.

  The alkenyl group of the surface modifying material is crosslinked by reacting with the H—Si group in the silicone resin. The H—Si group of the surface modifying material is crosslinked by reacting with the alkenyl group in the silicone resin. The alkoxy group of the surface modifying material is condensed with the alkoxy group in the silicone resin through hydrolysis. By such bonding, the silicone resin and the surface modifying material are integrated, so that the strength and denseness of the obtained cured product can be improved.

  The structure of the resin component is not particularly limited, and may be a two-dimensional chain structure, a three-dimensional network structure, or a cage structure.

The resin component only needs to be a polymer that has been cured when used as the transparent sealing member 30, and may be in a state before curing of the resin, that is, a precursor in the resin composition. Therefore, the resin component present in the resin composition may be a monomer, an oligomer, a prepolymer, or a polymer.
As the resin component, an addition reaction type, a condensation reaction type, or a radical polymerization reaction type may be used.

  The viscosity of the resin component is, for example, from 10 mPa · s to 100,000 mPa · s, preferably from 100 mPa · s to 10,000 mPa · s, more preferably from 1,000 mPa · s to 7,000 mPa · s.

Moreover, although content of the resin component in the resin composition which concerns on this embodiment can be made into the remainder of another component, it is 10 mass% or more and 70 mass% or less, for example.
The mass ratio of the resin component to the metal oxide particles in the resin composition according to the present embodiment is preferably resin component: metal oxide particles and is in the range of 50:50 to 90:10, and 60:40 More preferably in the range of ˜80: 20.

  Moreover, the resin composition may include a surface modifying material. In the resin composition, at least a part of the surface modifying material adheres to the surface of the metal oxide particles and prevents aggregation of the metal oxide particles. Furthermore, the compatibility of the metal oxide particles with the above-described resin component is improved.

  Here, the phrase “the surface modifying material“ attaches ”to the metal oxide particles means that the surface modifying material contacts or bonds to the metal oxide particles by the interaction between them. Examples of the contact include physical adsorption. Examples of the bond include ionic bond, hydrogen bond, and covalent bond.

Such a surface-modifying material is not particularly limited as long as it can adhere to the metal oxide particles and has good compatibility with the resin component.
As such a surface modifying material, a surface modifying material having at least one functional group selected from the group consisting of reactive functional groups such as alkenyl groups, H-Si groups, and alkoxy groups is preferably used. The surface modifying material having such a functional group is excellent in affinity with the dispersion medium and the resin component, and can improve the dispersibility of the metal oxide particles in the resin composition.

As the alkenyl group, for example, a linear or branched alkenyl group having 2 to 5 carbon atoms can be used, and specific examples include a vinyl group, a 2-propenyl group, a prop-2-en-1-yl group, and the like. It is done.
As an alkoxy group, a C1-C5 linear or branched alkoxy group is mentioned, for example, Specifically, a methoxy group, an ethoxy group, n-propoxy group, an isopropoxy group, a butoxy group etc. are mentioned.

  Examples of the surface modifying material having at least one functional group selected from the group consisting of an alkenyl group, an H-Si group, and an alkoxy group include vinyltrimethoxysilane, isobutyltrimethoxysilane, phenyltrimethoxysilane, alkoxy one end Dimethylsilicone vinyl end terminal, methyl phenyl silicone end terminal vinyl phenyl terminal, phenyl phenyl end terminal alkoxy terminal vinyl, methacryloxypropyltrimethoxysilane, acryloxypropyltrimethoxysilane, methacrylic acid and other fatty acids containing carbon-carbon unsaturated bonds , Dimethyl hydrogen silicone, methyl phenyl hydrogen silicone, phenyl hydrogen silicone, dimethyl chlorosilane, methyl dichloro silane, diethyl chloro silane, ethyl dichloro Rosilane, methylphenylchlorosilane, diphenylchlorosilane, phenyldichlorosilane, trimethoxysilane, dimethoxysilane, monomethoxysilane, triethoxysilane, diethoxymonomethylsilane, monoethoxydimethylsilane, methylphenyldimethoxysilane, diphenylmonomethoxysilane, methylphenyl Diethoxysilane, diphenylmonoethoxysilane, alkoxy both-end phenyl silicone, alkoxy both-end methyl phenyl silicone, methyl phenyl silicone oligomer, alkoxy group-containing dimethyl silicone resin, alkoxy group-containing phenyl silicone resin, alkoxy group-containing methyl phenyl silicone resin, and Selected from the group of alkoxy one-end trimethyl one-end dimethyl silicone It is preferable to use more species or in combination.

  Among these surface modification materials, vinyltrimethoxysilane, isobutyltrimethoxysilane, phenyl, and the like in the resin composition, in which aggregation of metal oxide particles is suppressed and a highly transparent sealing member is easily obtained. It is preferable to use one or more selected from the group consisting of trimethoxysilane, alkoxy-terminated trimethyl-terminated dimethylsilicone, and methylphenylsilicone oligomer.

  The content of the surface modifying material in the resin composition is preferably 1% by mass to 80% by mass, and more preferably 5% by mass to 40% by mass with respect to the mass of the metal oxide particles.

  Examples of the method for attaching the surface modifying material to the metal oxide particles include a dry method in which the surface modifying material is directly mixed and sprayed on the metal oxide particles, or a metal in water or an organic solvent in which the surface modifying material is dissolved. There is a wet method in which oxide particles are introduced and the surface is modified in a solvent.

  Moreover, the resin composition may contain phosphor particles as appropriate. The phosphor particles are not particularly limited, and can be appropriately selected and used so that the emission color of the light-emitting device becomes a desired color. The content of the phosphor particles in the resin composition can be appropriately adjusted and used so that desired brightness can be obtained. In addition, when the physical quantity of the phosphor particles is also determined in the second step, the phosphor particles are blended into the resin composition based on the determined physical quantity.

  Further, the resin composition may contain a dispersion medium. The dispersion medium assists the dispersion of the metal oxide particles and also acts as a diluent for the resin composition. Examples of such a dispersion medium include organic solvents such as alcohols, ketones, aromatics, saturated hydrocarbons, and unsaturated hydrocarbons. These solvents may be used alone or in combination of two or more. From the viewpoint of compatibility with the silicone resin, an organic solvent having an aromatic ring is preferable, and toluene, xylene, benzene and the like are particularly preferably used.

  The dispersion medium may be contained in an amount of, for example, 1% by mass to 10% by mass, specifically 2% by mass to 5% by mass with respect to the mass of the resin composition.

  The resin composition may contain commonly used additives such as preservatives, polymerization initiators, polymerization inhibitors, and curing catalysts.

  The transparent sealing member 30 can be formed by applying the above resin composition into the concave portion 11 of the substrate 10 using, for example, a dispenser and irradiating or heating energy rays such as ultraviolet rays.

  As described above, according to the method according to the present embodiment as described above, the physical quantity of the metal oxide particles for improving the light extraction efficiency can be appropriately determined. For example, in manufacturing the light-emitting device 1 described above, it is possible to determine a more appropriate value for the average dispersed particle size and content of the metal oxide particles. Therefore, the light extraction efficiency of the light emitting device manufactured based on the method according to the present embodiment is improved.

  Hereinafter, the present invention will be described in more detail with reference to examples. In addition, the Example described below is an example of this invention to the last, Comprising: This invention is not limited.

<1. Ray tracing simulation>
First, by changing the physical quantity of the metal oxide particles and the physical quantity of the phosphor particles, a light tracing simulation was performed to estimate and evaluate the light extraction efficiency of the light emitting device.

  In addition, the structure of each structural member of the light-emitting device was assumed as follows.

  FIG. 7 shows the assumed light-emitting element spectrum, phosphor particle absorption spectrum, phosphor excitation spectrum, and phosphor emission spectrum. The assumed particle size distribution of the phosphor particles is shown in FIG.

[1.1 Simulation 1 Light emitting device model not including phosphor particles]
First, ray tracing simulation was performed assuming the light emitting device 1 shown in FIG. The transparent sealing member 30 is a resin in which phosphor particles are not included and metal oxide particles (zirconium oxide) having an average particle diameter of 100 nm are uniformly mixed. In this simulation, the width W _{T1 of the} opening is 2.40 mm, the width W _B1 of the bottom is 2.20 mm, the depth D1 of the recess is 0.35 mm, the width of the light emitting element is 0.55 mm, and the thickness is 0.15 mm. It set so that it might become. In such a setting model, a ray tracing simulation is performed when the content of zirconium oxide is changed between 0% by mass and 3.0% by mass, and the total luminous flux (lm) and radiation emitted from the light emitting device. The bundle (W) was estimated.

  FIG. 9 shows a ray tracing result when the zirconium oxide content is 0% by mass, and FIG. 10 shows a ray tracing result when the zirconium oxide content is 0.6% by mass. FIG. 11 shows the relationship between the zirconium oxide content, the estimated total luminous flux (lm) of the light emitting device, and the radiant flux (W).

  As shown in FIG. 9, when the transparent sealing member does not contain zirconium oxide, there is a high probability that light emitted from the light emitting element reaches not only the vicinity of the light emitting element but also the wall surface (reflector) of the substrate. Therefore, there are many light rays that are once reflected by the reflector and emitted to the outside. On the other hand, when the transparent sealing member contains zirconium oxide as shown in FIG. 10, as a result of scattering by the zirconium oxide in the vicinity of the light emitting element, the diffusion of light rays in the plane direction of the substrate is suppressed, and the reflector The amount of light emitted outside without being reflected increased. Furthermore, as shown in FIG. 11, it was estimated that as the content of zirconium oxide increases, the total luminous flux and the radiant flux are improved, that is, the light extraction efficiency of the light emitting device is improved.

  In the light emitting device, when the light beam is reflected by the reflector, the light energy of the light beam is lost. Therefore, it has been confirmed that the light extraction efficiency of the light emitting device can be improved by using the scattering effect of zirconium oxide to reduce the light that is reflected by the reflector and then emitted to the outside.

[1.2 Simulation 2 Light-emitting device model including phosphor particles]
A ray tracing simulation was performed assuming the light emitting device 1A shown in FIG. In this simulation, the transparent sealing member 30A shown in FIG. 2 includes phosphor particles, and is disposed on the first layer 31A and the first layer 31A disposed directly on the light emitting element and on the lead frame. And a second layer 33A that does not contain phosphor particles. In both the first layer 31A and the second layer 33A, metal oxide particles (zirconium oxide) having an average particle diameter of 100 nm are uniformly dispersed.

In this simulation, the width W _{T2 of the} opening is 2.40 mm, the width W _B2 of the bottom is 2.20 mm, the depth D2 of the recess is 0.35 mm, the width of the light emitting element is 0.55 mm, and the thickness is 0. It was set to be 15 mm. On the other hand, as shown in Table 2, for the first layer, models (packages 1 to 4) in which the thickness was changed outside the light emitting element and on the light emitting element were prepared.

  In the above model, a ray tracing simulation is performed when the zirconium oxide content is changed between 0 mass% and 3.0 mass%, and the total luminous flux (lm) and radiant flux ( W).

  FIG. 12 shows the relationship between the zirconium oxide content and the estimated total luminous flux (lm) of the light emitting device, and FIG. 13 shows the relationship between the zirconium oxide content and the estimated radiant flux (W) of the light emitting device. FIG. 14 shows the relationship between the zirconium oxide content and the rate of increase of the total luminous flux (lm) of the light emitting device. FIG. 15 shows the increase of the radiant flux (W) of the light emitting device estimated as the zirconium oxide content. The relationship with the rate is shown.

  As shown in FIGS. 12 and 13, it was confirmed that when the transparent sealing member contains zirconium oxide, the light extraction efficiency of the light emitting device can be improved even when the transparent sealing member contains phosphor particles. 14 and 15, when the package 1 and the package 2 are compared, and the package 3 and the package 4 are compared, the effect of improving the light extraction efficiency is obtained as the phosphor layer thickness on the light emitting element is smaller. It was confirmed that it was easy to be done. Further, in FIGS. 14 and 15, when the package 1 and the package 3 are compared and the package 2 and the package 4 are compared, the effect of improving the light extraction efficiency is increased as the thickness of the phosphor layer outside the light emitting element is increased. It was confirmed that is easily obtained.

  Further, in the model assuming the light emitting device 1A of FIG. 2, in order to adjust the chromaticity of the light emitted from the light emitting device to the white point (x = 0.33, y = 0.33 in the CIE chromaticity diagram). The required volume concentration (volume%) of the phosphor particles was simulated. The results are shown in FIG.

  As shown in FIG. 16, it was confirmed that the amount of phosphor particles necessary for obtaining white color can be reduced as the content of zirconium oxide particles increases. This is presumed to be due to an increase in the amount of light irradiated per phosphor particle due to the scattering effect of the zirconium oxide particles.

[1.3 Simulation 3 Side-view light-emitting device model]
A ray tracing simulation was performed assuming the side-view type light emitting device 1B shown in FIGS. In this simulation, the transparent sealing member 30B shown in FIG. 3 and FIG. 4 includes phosphor particles, and is disposed on the first layer 31B and the first layer 31B disposed immediately above the light emitting element and on the lead frame. And a second layer 33B that does not include phosphor particles. In both the first layer 31B and the second layer 33B, metal oxide particles (zirconium oxide) having an average particle diameter of 100 nm are uniformly dispersed.

  In this simulation, three models (packages 5 to 7) were prepared in which the dimensions of the recesses (cavities) of the light emitting device were changed as shown in Table 3. Note that the width of the light-emitting element was 0.70 mm in the longitudinal direction and 0.20 mm in the width direction, and the light-emitting element was disposed near the center of the recess. On the other hand, about the 1st layer, the thickness outside a light emitting element was 0.09 mm, and the thickness on a light emitting element was 0.1 mm.

  In the above model, a ray tracing simulation is performed when the zirconium oxide content is changed between 0 mass% and 3.0 mass%, and the total luminous flux (lm) and radiant flux ( W).

  FIG. 17 shows the relationship between the zirconium oxide content and the estimated total luminous flux (lm) of the light emitting device, and FIG. 18 shows the relationship between the zirconium oxide content and the estimated radiant flux (W) of the light emitting device.

  As shown in FIGS. 17 and 18, when the transparent sealing member contains zirconium oxide, it was confirmed that the light extraction efficiency can be improved even in a side-view type light emitting device.

  Further, in the model assuming the light emitting device 1B of FIGS. 3 and 4, the chromaticity of light emitted from the light emitting device is adjusted to the white point (x = 0.33, y = 0.33 in the CIE chromaticity diagram). The volume concentration (volume%) of the phosphor particles necessary for the simulation was simulated. The results are shown in FIG.

  As shown in FIG. 19, it was confirmed that even in a side-view type light emitting device, the amount of phosphor particles necessary for obtaining white color can be reduced as the content of zirconium oxide particles increases.

[1.4 Simulation 4 Side-view light-emitting device model with two light-emitting elements]
A ray tracing simulation was performed assuming the side view type light emitting device 1C shown in FIGS. In this simulation, the transparent sealing member 30B shown in FIGS. 5 and 6 includes a first layer 31B that includes phosphor particles and is disposed immediately above the light emitting element 20C and on the lead frame 50C. And a second layer 33B that does not include phosphor particles. In both the first layer 31B and the second layer 33B, metal oxide particles (zirconium oxide) having an average particle diameter of 100 nm are uniformly dispersed.

Further, in this simulation, the size of the recess (cavity) of the light emitting device is such that the opening length L _T4 is 3.6 mm, the width W _T4 is 0.63 mm, the bottom length L _B4 is 3.1 mm, and the width. the W _B4 was 0.59mm. The dimensions of the light emitting elements were 0.70 mm in length and 0.20 mm in width, and the light emitting elements were arranged in the vicinity of the center of the recess with a distance of 0.20 mm between the light emitting elements along the longitudinal direction of the substrate. On the other hand, about the 1st layer, the thickness outside a light emitting element was 0.09 mm, and the thickness on a light emitting element was 0.1 mm.

  FIG. 20 shows the relationship between the zirconium oxide content and the estimated total luminous flux (lm) of the light emitting device, and FIG. 21 shows the relationship between the zirconium oxide content and the estimated radiant flux (W) of the light emitting device.

  As shown in FIGS. 20 and 21, when the transparent sealing member contains zirconium oxide, the light extraction efficiency can be improved even in a side-view type light emitting device having two light emitting elements. confirmed.

  Further, in the model assuming the light emitting device 1C of FIGS. 5 and 6, the chromaticity of light emitted from the light emitting device is adjusted to the white point (x = 0.33, y = 0.33 in the CIE chromaticity diagram). The volume concentration (volume%) of the phosphor particles necessary for the simulation was simulated. The results are shown in FIG.

  As shown in FIG. 22, even in a side-view type light-emitting device equipped with two light-emitting elements, as the content of zirconium oxide particles increases, the amount of phosphor particles necessary to obtain white is reduced. It was confirmed that

  As a result of the above simulation, by including metal oxide particles having a refractive index of 1.7 or more and an average dispersed particle size of 40 nm or more and 200 nm or less in the transparent sealing member, It was confirmed that the take-out efficiency of can be improved.

<2. Production and evaluation of light emitting device>
Based on the simulation results described above, the concentration and average dispersed particle size of the metal oxide particles were determined, the light emitting device was manufactured as follows, and the light extraction efficiency of the light emitting device was evaluated.

[Example 1]
(Preparation of dispersion)
10 g of zirconium oxide particles (Sumitomo Osaka Cement Co., Ltd.) having an average primary particle size of 5 nm, 82 g of toluene, and 5 g of methoxy group-containing phenyl silicone resin (KR217, manufactured by Shin-Etsu Chemical Co., Ltd.) as a surface modifying material were added and mixed. This mixed solution was subjected to a dispersion treatment for 6 hours with a bead mill to obtain a dispersion according to Example 1.

(Evaluation of particle size)
A part of the obtained dispersion was collected and diluted with toluene so that the solid content was 5% by mass.
D50 of this diluted dispersion was measured using a particle size distribution meter (manufactured by HORIBA, model number: SZ-100SP). As a result, D50 was 32 nm. The results are shown in Table 1. In addition, since the particle | grains contained in a dispersion liquid are fundamentally only the zirconium oxide particle to which the surface modification material adhered, it was thought that D50 measured was an average dispersion | distribution particle diameter of a zirconium oxide particle.

(Preparation of resin composition)
10 g of the obtained dispersion liquid according to Example 1, methyl phenyl silicone resin as a silicone resin (OE-6520 manufactured by Toray Dow Corning Co., Ltd., refractive index 1.54, A liquid: B liquid mass mixing ratio = 1: 1 (resin 7.6 g) was mixed. Subsequently, toluene was removed from this mixed solution by drying under reduced pressure to obtain a resin composition according to Example 1 containing surface-modified zirconium oxide particles and a methylphenyl silicone resin (OE-6520). The contents of zirconium oxide particles and toluene in the composition were 11% by mass and 2% by mass, respectively.

(Evaluation of composition transmittance)
The transmittance of the obtained resin composition was measured with a spectrophotometer V-770 (manufactured by JASCO Corporation) using an integrating sphere. A measurement sample having a thickness (optical path length) of 1 mm with a silicone composition sandwiched between thin-layer quartz cells was used.
As a result, the transmittance of the resin composition at a wavelength of 460 nm was 84%, and the transmittance at a wavelength of 600 nm was 90%. The results are shown in Table 4.

(Production of cured body)
A cured product was prepared in order to measure the transmittance of the transparent sealing member and the particle size of the metal oxide particles. A SUS substrate was provided with a groove having a length of 20 mm, a width of 15 mm, and a depth of 5 mm, and the groove was coated with fluorine. The resin composition obtained so as to have a thickness of 0.5 mm after curing with respect to the groove of the mold was poured, cured by heating at 150 ° C. for 4 hours, and removed from the SUS substrate. Such a cured product was obtained.

(Evaluation of transmittance of cured product)
The transmittance of the obtained cured product was measured with a spectrophotometer V-770 (manufactured by JASCO Corporation) using an integrating sphere.
As a result, the transmittance of the cured product at a wavelength of 460 nm was 25%, and the transmittance at a wavelength of 600 nm was 70%. The results are shown in Table 4.

(Average dispersion particle size of metal oxide particles in the cured product)
The average dispersed particle size of the zirconium oxide particles in the cured product was measured with a field emission type transmission electron microscope (JEM-2100F, manufactured by JEOL Ltd.) using a sample obtained by slicing the cured product in the thickness direction. The results are shown in Table 4.

(Production of LED package and evaluation of total luminous flux)
The blue light emitting diode (LED chip) was sealed with the resin composition according to Example 1 using a capacity-calculating digital control dispenser (trade name: MEASURING MASTER MPP-1, manufactured by Musashi Engineering Co., Ltd.). The composition was heat-treated at 150 ° C. for 2 hours to be cured, thereby producing a 3030 series (3.0 mm × 3.0 mm) LED package (light emitting device) according to Example 1. The structure of the light emitting device is the same as that shown in FIG.

The total luminous flux of this LED package was measured using a total luminous flux measurement system HM series (Otsuka Electronics Co., Ltd., sphere size 3000 mm).
As a result, the total luminous flux of the LED package according to Example 1 was 61.2 lm.

[Examples 2 and 3]
A light emitting device was manufactured in the same manner as in Example 1 except that the primary particle diameter and the average dispersed particle diameter of zirconium oxide particles as metal oxide particles were as shown in Table 4.

[Example 4]
A light emitting device was manufactured in the same manner as in Example 1 except that the titanium oxide particles shown in Table 4 were used as the metal oxide particles.

[Comparative Examples 1-4]
A light emitting device was manufactured in the same manner as in Example 1 except that the primary particle diameter and the average dispersed particle diameter of zirconium oxide particles as metal oxide particles were as shown in Table 4.
The results are shown in Table 4.

  From the results of Examples 1 to 4 and Comparative Examples 1 to 4, by using metal oxide particles having a refractive index of 1.7 or more and an average dispersed particle size of 40 nm or more and 200 nm or less as a material for the transparent sealing member, It was confirmed that a light emitting device excellent in light extraction efficiency can be obtained.

  The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

1, 1A, 1B, 1C Light emitting device 10, 10B Substrate 11, 11B Recess 13, 13B Wall surface 15, 15B Bottom surface 17, 17B Opening portion 20, 20B, 20C Light emitting element 30, 30A, 30B Transparent sealing member 31A, 31B First First layer 33A, 33B Second layer 40 Bonding wire 50, 50B, 50C Lead frame

Claims (2)

A substrate having a recess, a light emitting element disposed on a bottom surface of the recess, and a transparent sealing member disposed in the recess and sealing the light emitting element, wherein the transparent sealing member and the resin A method of determining a physical quantity of the metal oxide particles in a light-emitting device, comprising metal oxide particles having a refractive index of 1.7 or more dispersed in a resin,
Assuming that the physical quantity of the metal oxide particles is changed, a first estimation of the radiation amount or photometric quantity of the light emitted from the light emitting device within the assumed range of change of the physical quantity of the metal oxide particles is performed. And the process of
A second step of determining a physical quantity of the metal oxide particles based on the estimated radiation amount or the photometric quantity;
A method for determining a physical quantity of metal oxide particles in a light emitting device. The transparent sealing member further includes phosphor particles,
In the first step, assuming that the physical quantity of the metal oxide particles and the physical quantity of the phosphor particles are changed, the assumed physical quantity of the metal oxide particles and the change of the physical quantity of the phosphor particles are changed. The method for determining a physical quantity of metal oxide particles in a light-emitting device according to claim 1, wherein a radiation amount or a photometric amount of light emitted from the light-emitting device in a range is estimated.

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