JP6005958B2 - Light emitting device and manufacturing method thereof - Google Patents

Description

  The present invention relates to a light emitting device having a wavelength conversion layer containing a plurality of phosphor particles on a semiconductor layer forming a light emitting element, and a method for manufacturing the same.

  A wavelength conversion layer composed of a resin layer containing a plurality of phosphor particles is formed on a semiconductor layer that constitutes a light emitting element such as a light emitting diode, and a part of light from the semiconductor layer differs depending on the phosphor particles in the wavelength conversion layer. 2. Description of the Related Art A light emitting device that converts light into a wavelength and emits light after being converted by phosphor particles by mixing with light passing through a wavelength conversion layer from a semiconductor layer is known.

  In such a light emitting device, in general, in order to form a wavelength conversion layer, a solution containing phosphor particles is applied and cured on the main surface on the light emission side of the semiconductor layer by spraying, and the phosphor particles are further cured. In order to fill the gap, a glass binder solution is applied and cured by spraying (see Patent Document 1). It is desirable that the phosphor particles in the wavelength conversion layer are uniformly distributed over the entire upper surface of the semiconductor layer so that the amount of incident light from the semiconductor layer is not wavelength-converted and is emitted as it is. . Therefore, for example, Patent Document 1 shows that a coating liquid containing a phosphor is sprayed from above the light emitting element while rotating in a mist-like and spiral manner.

JP 2004-088013 A

  However, in such a conventional light emitting device, when the resin containing the phosphor particles is uniformly applied to the upper surface of the semiconductor layer by spraying, the phosphor particles are collected even if a device such as a spiral coating is applied. It is difficult to form a wavelength conversion layer in which the phosphor particles are uniformly distributed due to the occurrence of a gap and a portion having a gap between the phosphor particles. For this reason, the light emitted from the semiconductor layer is emitted through the gaps between the phosphor particles as they are. For example, when the emission color of the semiconductor layer is blue and the phosphor particles in the wavelength conversion layer convert blue light into yellow light, the blue light passes through the gaps between the phosphor particles and is emitted. Then, there is a problem that blue light is partially generated and color unevenness occurs in the light emitted from the light emitting device.

  Accordingly, an object of the present invention has been made in view of the above points, and provides a light emitting device capable of suppressing color unevenness even when there is a gap between phosphor particles in the wavelength conversion layer, and a method for manufacturing the same. It is to be.

The light-emitting device of the present invention is a light-emitting device including a light-emitting element and a wavelength conversion layer that is disposed on the light-emitting element and includes a plurality of phosphor particles, wherein some of the plurality of phosphor particles are located in the surface portion of the wavelength conversion layer, the wavelength conversion layer has a depression in the surface adjacent the phosphor particles of said portion, the light emitting device will have a light scattering layer formed in said recess, The wavelength conversion layer including the light scattering layer has a flat surface .
The light-emitting device of the present invention is a light-emitting device including a light-emitting element and a wavelength conversion layer that is disposed on the light-emitting element and includes a plurality of phosphor particles, wherein some of the plurality of phosphor particles are Located on the surface portion of the wavelength conversion layer, the wavelength conversion layer has a dent on the surface adjacent to the part of the phosphor particles, and the wavelength conversion layer fills between the plurality of phosphor particles. When the light emitting device is observed from above including a binder, the upper surface of the light emitting element has an upper surface exposed region where the phosphor particles are not present, and the light emitting device has the light transmitting property in the upper surface exposed region. The binder has a light scattering layer in the recess formed by having a thickness in the range of half the height of the wavelength conversion layer to 2/3, and the light transmissive binder contains light scattering particles. Not included and the light diffused on the top exposed area. Are arranged such layers overlap, the phosphor particles of the part is characterized by forming the protruding surface portion of the wavelength conversion layer.

The manufacturing method of the light-emitting device of the present invention includes a first step of applying a coating liquid having a plurality of phosphor particles on a light-emitting element and disposing the plurality of phosphor particles on the light-emitting element; After the step, the translucent binder is disposed on the light emitting element by applying a solution of the translucent binder on the light emitting element on which the plurality of phosphor particles are disposed. A second step of forming a wavelength conversion layer containing the plurality of phosphor particles, and a third step of forming a light scattering layer on the wavelength conversion layer after the second step. a method of manufacturing a non-emitting device, a part of the plurality of phosphor particles is located in the surface portion of the wavelength conversion layer, said wavelength conversion layer is the permeability to a surface adjacent the phosphor particles of said portion A light-sensitive binder indentation, and the light scattering in the indentation in the third step There is formed, the manufacturing method, after the third step, is characterized in that it comprises a fourth step of flattening the surface of the wavelength conversion layer including the light scattering layer.
The manufacturing method of the light-emitting device of the present invention includes a first step of applying a coating liquid having a plurality of phosphor particles on a light-emitting element and disposing the plurality of phosphor particles on the light-emitting element; After the step, the translucent binder is disposed on the light emitting element by applying a solution of the translucent binder on the light emitting element on which the plurality of phosphor particles are disposed. And a second step of forming a wavelength conversion layer containing the plurality of phosphor particles, and a third step of forming a light scattering layer on the wavelength conversion layer after the second step. The light-transmitting binder does not contain light scattering particles, a part of the plurality of phosphor particles is located on a surface portion of the wavelength conversion layer, and the wavelength conversion layer is the part of the wavelength conversion layer. Whether the translucent binder is half the height of the wavelength conversion layer on the surface adjacent to the phosphor particles. The phosphor particles have a depression formed by setting the thickness to a range of 2/3, and the part of the phosphor particles forms a protruding surface portion of the wavelength conversion layer. In the third step, the depression is formed in the depression. The light scattering layer is formed.

  According to the light emitting device and the method of manufacturing the same of the present invention, since the scattering layer is formed in the depression on the surface of the wavelength conversion layer, the gap portion between the phosphor particles on the surface portion of the wavelength conversion layer from the light emitting element. The light passing through the light scattering layer can be irregularly reflected by the light scattering layer, and part of the irregularly reflected light can be incident on the phosphor particles to emit the wavelength-converted light. For example, when the emission color of the light-emitting element is blue and the phosphor particles in the wavelength conversion layer convert blue light into yellow light, the light scattering layer in the gap between some phosphor particles diffuses blue light A part of the blue light irregularly reflected is incident on the phosphor particles and converted into yellow light. The yellow light is diffusely reflected and mixed with the blue light emitted as it is to become white light. Therefore, color unevenness caused by the blue light emitted from the light emitting element passing through the wavelength conversion layer as it is and emitted from the light emitting device can be suppressed.

It is sectional drawing which shows the light-emitting device of Example 1 of this invention. It is a figure which shows the spray injection in the manufacture process of the light-emitting device of Example 1. FIG. 6 is a cross-sectional view showing a method for manufacturing the light-emitting device of Example 1. FIG. 3 is a diagram illustrating an optical path in a wavelength conversion layer of the light emitting device of Example 1. FIG. It is a figure which shows the optical path in the wavelength conversion layer of the conventional light-emitting device. It is sectional drawing which shows the light-emitting device of Example 2 of this invention. 6 is a cross-sectional view showing a method for manufacturing the light emitting device of Example 2. FIG. 6 is a diagram illustrating an optical path in a wavelength conversion layer of a light emitting device according to Example 2. FIG. It is sectional drawing which shows the light-emitting device of Example 3 of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a cross-sectional view of a light emitting device of Example 1 of the present invention. In this light emitting device, a wavelength conversion layer 13 is formed on a light emitting element composed of a substrate 10 and a semiconductor layer 11. The substrate 10 is a silicon substrate, and a semiconductor layer 11 including a light emitting layer formed as a GaN-based epitaxial layer is disposed on the substrate 10. The light emitting element is a metal bonding type light emitting element (light emitting diode), and the semiconductor layer 11 is metal-bonded to the substrate 10. The semiconductor layer 11 emits blue light in this embodiment.

  A large number of phosphor particles 14 are dispersed in the wavelength conversion layer 13. The phosphor particles 14 are, for example, YAG phosphor particles that are excited by light emitted from the semiconductor layer 11 and emit fluorescence of a predetermined wavelength. In this embodiment, the phosphor particles 14 are excited by blue light emitted from the semiconductor layer 11 and emit yellow light. The average particle diameter of the phosphor particles 14 is 15 μm. The periphery of the phosphor particles 14 is covered with a transparent adhesive 15. Further, the gap between the phosphor particles 14 is filled with a binder 16. The transparent adhesive 15 and the binder 16 have translucency with respect to the fluorescence emitted from the phosphor particles 14 as well as the light emitted from the semiconductor layer 11. The binder 16 uses an inorganic glass-based compound (ethyl silicate), but can use a transparent resin such as dimethyl silicone and phenyl silicone adjusted to a low viscosity with an organic solvent, and further a mixture thereof. May be. The binder 16 does not contain a light scattering material. Although the phosphor particles 14 are dispersed in the wavelength conversion layer 13, there are portions where the phosphor particles 14 gather and exist, and some of the phosphor particles 14 are located near the surface of the wavelength conversion layer 13. A protruding surface portion of the wavelength conversion layer 13 is formed.

  A light scattering layer 17 is formed on the wavelength conversion layer 13. The light scattering layer 17 is made of a glass binder (a silicone resin may be used) in which a light scattering material is dispersed. The light scattering material is, for example, alumina particles having a size of 1 μm or less, but may have light scattering particles having a particle size of 100 nm to 2 μm.

  The layer thickness of the light scattering layer 17 is smaller than the particle diameter of the phosphor particles 14 and is 5 μm or less, which is 1/3 of the average particle diameter of the phosphor particles 14. In the surface of the binder 16 adjacent to the phosphor particles 14 located in the vicinity of the surface of the wavelength conversion layer 13, particularly in the gap portion between the phosphor particles 14 forming the protruding surface portion of the wavelength conversion layer 13. There is a recess 20. The inside of the recess 20 is filled with the light scattering layer 17, and the layer thickness is thick. On the other hand, the thickness of the light scattering layer 17 above the phosphor particles 14 forming the protruding surface portion of the wavelength conversion layer 13 is thin, for example, 2 μm or less. The light scattering layer 17 is disposed on the upper surface of the light emitting element so as to overlap an area where the phosphor particles do not exist above.

As shown in FIG. 2, the adhesive 15, the binder 16, and the light scattering layer 17 containing the phosphor particles 14 are sprayed and applied in a liquid state with a spray 21, and then dried. It is formed. The spray 21 moves in the direction indicated by the arrow 22 in FIG. 2 (direction parallel to the upper surface of the semiconductor layer 11) during spraying, and reciprocates depending on the coating amount. The materials of the adhesive 15, the binder 16, and the light scattering layer 17, which are liquefied by a volatile organic solvent such as alcohol or xylene for injection by the spray 21 (phosphor particle-containing liquid 35, binder described later, binder) Liquid 36 and light scattering material-containing binder liquid 37) are used. Spray 21
FIGS. 3A to 3C show the coated portions of the materials for the adhesive 15, the binder 16, and the light scattering layer 17 in the method for manufacturing the light emitting device of Example 1 of FIG. The light emitting device is manufactured in the order of FIGS. That is, the phosphor particle-containing liquid application process (first process), the binder liquid application process (second process), and the light scattering material-containing binder liquid application process (third process) are performed in that order.

  Before these steps, there is a step in which the substrate material corresponding to the substrate 10 and the epitaxial layer corresponding to the semiconductor layer 11 are bonded by fusion bonding between the metal bonding layers, and the substrate material is divided into device units. Then, it is assumed that a light emitting element including the substrate 10 and the semiconductor layer 11 including the light emitting layer formed on the substrate 10 is obtained.

  In the phosphor particle-containing liquid application step, as shown in FIG. 3A, a phosphor particle-containing liquid 35 containing the phosphor particles 14 is applied on a device basis. The phosphor particle-containing liquid 35 is sprayed onto the upper surface of the semiconductor layer 11 by the spray 21 described above. The viscosity of the phosphor particle-containing liquid 35 is, for example, 100 mPa · s, but may be a value within the range of 20 to 500 mPa · s. The concentration of the phosphor particles 14 in the phosphor particle-containing liquid 35 is, for example, 50 wt%, but may be 10 to 80 wt%. After spraying, the phosphor particle-containing liquid 35 is dried for curing. In this phosphor particle-containing liquid coating step, a portion where the phosphor particles 14 are concentrated and a portion where the phosphor particles 14 overlap are generated.

  In the binder liquid coating step, as shown in FIG. 3B, the binder liquid 36 is sprayed so as to fill the voids between the cured phosphor particle-containing liquid 35, that is, the phosphor particles 14 surrounded by the adhesive 15. 21 is applied by spraying. After spraying, the binder liquid 36 is dried for curing. As a result, the wavelength conversion layer 13 that includes the phosphor particles 14 and is filled with the binder 16 between the phosphor particles 14 is formed on the semiconductor layer 11. At this time, a protruding surface portion of the wavelength conversion layer 13 is formed by a portion where the phosphor particles 14 overlap upward, and a depression 20 of the binder 16 is generated between the phosphor particles 14.

  In the light scattering material-containing binder liquid application step, as shown in FIG. 3C, the light scattering material-containing binder liquid 37 is applied by spraying the spray 21 onto the cured binder liquid 36, that is, the binder 16. The viscosity of the light scattering material-containing binder liquid 37 is, for example, 150 mPa · s, but may be a value of 400 mPa · s or less. After jetting, the light scattering material-containing binder liquid 37 is dried for curing. As a result, as shown in FIG. 1, the light scattering layer 17 is formed on the wavelength conversion layer 13. The light scattering layer 17 is formed thick in the recess 20, and the light scattering layer 17 is formed thin on the phosphor particles 14 forming the protruding surface portion of the wavelength conversion layer 13.

  As described above, the thickness of the light scattering layer 17 is smaller than the particle diameter of the phosphor particles 14 and is 5 μm or less, which is 1/3 of the average particle diameter of the phosphor particles 14. The formed phosphor particles 14 are thinner and 2 μm or less. This is because the viscosity of the light scattering material-containing binder liquid 37 is adjusted to be as low as 150 mPa · s, so that it easily accumulates in the gaps between the phosphor particles 14 on the protruding surface portion of the wavelength conversion layer 13. However, it is because the phosphor particles 14 on the protruding surface portion of the wavelength conversion layer 13 flow from there and hardly accumulate.

  Further, the binder 16 in the gap portion of the phosphor particles 14 is recessed like a recess 20 compared to the surface position of the binder 16 in the portion where the phosphor particles 14 are gathered. Therefore, when the light scattering material-containing binder liquid 37 is sprayed onto the wavelength conversion layer 13 by the spray 21 and applied, the light scattering material-containing binder liquid 37 fills the recess 20 and light is emitted on the phosphor particles 14 on the protruding surface portion. The scattering material-containing binder liquid 37 is thinned or absent. Therefore, the thickness of the light scattering layer 17 after the light scattering material-containing binder liquid 37 is cured is a position where the phosphor particles 14 do not exist, that is, a gap portion between the phosphor particles 14 on the protruding surface portion of the wavelength conversion layer 13. The thickness is increased in the recess 20, and the thickness of the light scattering layer 17 above the phosphor particles 14 on the protruding surface portion is decreased. The bottom position of the light scattering layer 17 in the recess 20 (interface position between the light scattering layer 17 and the binder 16) is lower than the outermost surface position of each of the phosphor particles 14.

  In the light emitting device of Example 1, since the light scattering layer 17 is formed on the wavelength conversion layer 13 in this way, a protruding surface portion of the wavelength conversion layer 13 is formed from the semiconductor layer 11 as shown in FIG. Blue light (arrows A and B) having a relatively small light exit angle (light exit angle 0 to about ± 30 degrees) that enters the scattering layer 17 through the gap portion of the phosphor particles 14 is scattered. Diffuse reflection occurs at the layer 17. Part of the irregularly reflected light enters the phosphor particles 14 and emits yellow light (arrow C). In FIG. 4, the light incident on the scattering layer 17 is irregularly reflected in all directions, but a light beam whose wavelength is converted is shown for easy explanation of the present invention. In addition, the emission angle of 0 degrees is an angle at which light is emitted from the surface of the semiconductor layer 11 in the vertical direction, and the emission angle increases as the emission direction falls toward the surface side of the semiconductor layer 11.

  As shown in FIG. 5, in the case of a light emitting device in which the light scattering layer 17 does not exist, it passes from the semiconductor layer 11 through the gap portion of the phosphor particles 14 forming the protruding surface portion of the wavelength conversion layer 13. Blue light (arrow D) having a relatively small light emission angle (light emission angle 0 to about ± 30 degrees) is emitted as it is. For this reason, the blue light that passes through the gap portion of the phosphor particles 14 and is emitted as it is from the light emitting device causes color unevenness in which strong blue light is partially emitted from the light emitting device, resulting in poor chromaticity uniformity. . Moreover, the whitening conversion rate by the wavelength conversion layer 13 falls, and the brightness of a light-emitting device falls.

  On the other hand, in the light emitting device of Example 1, the light emission angle passing through the gap portion of the phosphor particles 14 forming the protruding surface portion of the wavelength conversion layer 13 from the semiconductor layer 11 is relatively small ( Blue light having a light emission angle of 0 to about ± 30 degrees is diffusely reflected by the light scattering layer 17 and partially enters the phosphor particles 14 to be converted into yellow light. Therefore, the blue light that passes through the gap portion of the phosphor particles 14 and is emitted from the light emitting device as it is is suppressed and partially wavelength-converted to yellow light. Color unevenness can be suppressed. And the whitening conversion rate by the wavelength conversion layer 13 can be made high compared with the light-emitting device of FIG. 5 without a light-scattering layer. The whitening conversion rate is the white light beam lm / blue light output (mW).

  Further, in the light emitting device of Example 1, the light scattering material is not included in the binder 16 as described above. This is because the blue light from the surface of the semiconductor layer 11 directly hits the phosphor particles 14 without being disturbed by the light scattering material and excites the phosphor particles efficiently. If a light scattering material is included in the binder 16, the blue light from the surface of the semiconductor layer 11 is refracted by the light scattering material before hitting the phosphor particles 14, and the intensity of the blue light becomes weaker every time it hits the light scattering material. The excitation of the phosphor particles becomes weak, causing a decrease in luminous flux and a change in luminous intensity of the light emitting device.

  Further, since the phosphor particle 14 itself has a higher wavelength conversion efficiency as the particle size is larger, the phosphor particle 14 is a relatively large particle (10 μm or more) such as the average particle size of 15 μm shown in Example 1. It is desired to use it. On the other hand, in the case of phosphor particles having a relatively large particle size, the particle size distribution is generally large, and the number of reciprocations of the spray 21 in the phosphor particle-containing liquid coating process is reduced. A gap is likely to occur. This means that the excitation light from the semiconductor layer 11 does not enter the phosphor particles 14 and is emitted from the wavelength conversion layer 13 as it is, resulting in color unevenness and poor wavelength conversion efficiency. In order to cope with this, in the light emitting device of Example 1, since the light scattering layer 17 is formed on the wavelength conversion layer 13, the fluorescent light forming the protruding surface portion of the wavelength conversion layer 13 from the semiconductor layer 11. Blue light (arrows A and B in FIG. 4) passing through the gaps between the body particles 14 can be irregularly reflected by the light scattering layer 17. A part of the irregularly reflected light enters the phosphor particles 14 and emits yellow light (arrow C). Therefore, according to the light emitting device of this example, even if the wavelength conversion layer 13 contains the phosphor particles 14 having a relatively large particle diameter, even if a gap is generated between the phosphor particles 14 (light emission). Even if a region where the phosphor particles 14 do not exist is formed directly on the upper surface of the device), light emitted without entering the phosphor particles 14 from the gap is suppressed, color unevenness is suppressed, and wavelength A light-emitting device with high conversion efficiency can be provided.

  In addition, in the phosphor particle-containing liquid coating process, the binder liquid coating process, and the light scattering material-containing binder liquid coating process in Example 1, a spray system in which the coating liquid is sprayed and sprayed in a mist form is used. In addition, a jet dispenser method or an electrostatic coating method can also be used.

  FIG. 6 shows a cross-sectional view of the light emitting device of Example 2 of the present invention. In this light emitting device, the wavelength conversion layer 13 is formed on the light emitting element composed of the substrate 10 and the semiconductor layer 11, and the light scattering layer 17 is formed on the wavelength conversion layer 13. Is the same. In the light emitting device of Example 2, the surface of the wavelength conversion layer 13 including the light scattering layer 17 is flattened so as to be parallel to the main surface of the semiconductor layer 11.

  7A to 7D show phosphor particle-containing liquid application step (first step), binder liquid application step (second step), and light scattering in the method of manufacturing the light emitting device of Example 2 in FIG. The material-containing binder liquid application step (third step) and the planarization step (fourth step) are shown.

  The phosphor particle-containing liquid coating process, the binder liquid coating process, and the light scattering material-containing binder liquid coating process are the same as those in the first embodiment shown in FIGS. However, in the binder liquid application process of the second embodiment, less binder liquid 36 is applied by spraying with the spray 21 than in the first embodiment. As shown in FIG. 7B, the binder liquid 36 is applied to a position that is approximately 2/3 of the height of the wavelength conversion layer 13 (in the range from half to 2/3), and then cured.

  In the light scattering material-containing binder liquid application step, as shown in FIG. 7 (c), the cured binder liquid 36, that is, the light scattering material-containing binder liquid 37 is applied onto the binder 16 by spraying with a spray 21, and then cured. Is done. The coating amount of the light scattering material-containing binder liquid 37 is larger than that in the first embodiment, and the thickness of the light scattering layer 17 is increased by the amount that the thickness of the binder 16 is reduced.

  In the planarization step, the surface of the light scattering layer 17 is ground and planarized using a grinder. For example, the substrate 10 formed up to the light scattering layer 17 is rotated, the grindstone of the rotated grinder is lowered from above toward the surface of the light scattering layer 17, and grinding is performed until a desired thickness is achieved. . As shown in FIG. 7D, not only the light scattering layer 17 but also the phosphor particles 14 and the binder 16 forming the protruding surface portion of the wavelength conversion layer 13 are ground. The light scattering layer 17 is ground until the thickness of the light scattering layer 17 becomes half or less of the average particle diameter of the phosphor particles 14. Further, the light scattering layer 17 does not exist on the surface of the portion where the phosphor particles 14 are ground.

  In the light emitting device of the second embodiment, as in the first embodiment, the blue light E and F having a relatively small light emission angle passing through the gap portion of the phosphor particles 14 is irregularly reflected by the light scattering layer 17 and partially Is incident on the phosphor particles 14 and converted into yellow light, so that the blue light emitted from the light emitting device is suppressed as it is and partly converted into yellow light G, so that it is partially strong in the light emitting device. Color unevenness in which blue light is emitted can be suppressed. And the whitening conversion rate by the wavelength conversion layer 13 can be made high compared with the light-emitting device without a light-scattering layer.

  Furthermore, in the light emitting device of Example 2, since the scattering layer formed in the unnecessary region is removed by planarization, it is possible to prevent a reduction in output due to light scattering in the scattering layer formed in the unnecessary region. Can do. That is, the phosphor particles 14 are present directly below the region on the phosphor particles 14 on the surface side of the wavelength conversion layer 13 (the X region in FIG. 8) and the gap between the phosphor particles 14 on the surface side of the wavelength conversion layer 13. It is preferable not to dispose the scattering layer on a region such as a region (Y region in FIG. 8). Therefore, by adopting a configuration in which the scattering layer 17 is not disposed on these regions, a decrease in light output due to unnecessary light scattering is suppressed compared to the case where the scattering layer 17 is disposed on these regions, and the white color is reduced. It is possible to provide a high-power light-emitting device with an increased rate of change in chemical conversion.

  In the light emitting device of Example 2, the thickness of the wavelength conversion layer 13 and the thickness of the light scattering layer 17 can be changed in flattening, that is, color adjustment is performed by adjusting the balance between transmitted light and wavelength converted light. Therefore, a light-emitting device with desired chromaticity can be provided.

  FIG. 9 shows a cross-sectional view of the light emitting device of Example 3 of the present invention. In this light emitting device, the wavelength conversion layer 13 is formed on the light emitting element composed of the substrate 10 and the semiconductor layer 11, and the light scattering layer 17 is formed on the wavelength conversion layer 13. Is the same. In the light emitting device of Example 3, the binder 16 has a thickness that is approximately 2/3 of the height of the wavelength conversion layer 13 (in the range of half to 2/3), and protrudes from the surface of the wavelength conversion layer 13 by that amount. The thickness of the light scattering layer 17 is thick in the gaps between the phosphor particles 14 that are being made. The layer thickness of the light scattering layer 17 above the position where the phosphor particles 14 protrude from the surface is thin, for example, 2 μm or less. Other configurations of the light emitting device of the third embodiment are the same as those of the first embodiment. Accordingly, since the scattering layer 17 can be formed deeper than in the first embodiment, more light having a relatively small light emission angle passing through the gap portion of the phosphor particles 14 is more than in the scattering layer 17 in the first embodiment. Since the probability of being scattered and entering the phosphor particles 14 can be increased, the whitening change rate can be further increased as compared with the light emitting device of Example 1, and a high output light emitting device can be provided.

  The laser diffraction method was used as a method for measuring the particle diameters of the phosphor particles and the light scattering material particles described above.

  In each of the above embodiments, the semiconductor layer 11 is a metal bonding type light emitting element, but the present invention can also be applied to other face-up type light emitting elements. Further, the semiconductor layer 11 is not limited to the GaN-based light emitting diode shown in the embodiment, and other light emitting elements of AlGaAs or ZnO can be used.

DESCRIPTION OF SYMBOLS 10 Substrate 11 Semiconductor layer 13 Wavelength conversion layer 14 Phosphor particle 15 Adhesive 16 Binder 17 Light scattering layer 21 Spray 35 Phosphor particle containing liquid 36 Binder liquid 37 Light scattering material containing binder liquid

Claims (7)

A light emitting device comprising: a light emitting element; and a wavelength conversion layer disposed on the light emitting element and including a plurality of phosphor particles,
Some of the plurality of phosphor particles are located on the surface portion of the wavelength conversion layer, the wavelength conversion layer has a depression on the surface adjacent to the some phosphor particles,
The light emitting device will have a light scattering layer formed in said recess,
The light emitting device, wherein a surface of the wavelength conversion layer including the light scattering layer is formed flat . A light emitting device comprising: a light emitting element; and a wavelength conversion layer disposed on the light emitting element and including a plurality of phosphor particles,
  Some of the plurality of phosphor particles are located on the surface portion of the wavelength conversion layer, the wavelength conversion layer has a depression on the surface adjacent to the some phosphor particles,
  The wavelength conversion layer includes a translucent binder that fills between the plurality of phosphor particles,
  When the light emitting device is observed from above, the upper surface of the light emitting element has an upper surface exposed region where the phosphor particles do not exist,
  The light emitting device has a light scattering layer in the recess formed by the translucent binder having a thickness in the range of half to 2/3 of the height of the wavelength conversion layer in the upper surface exposed region. And
  The translucent binder does not contain light scattering particles,
  The light-emitting device, wherein the light scattering layer is disposed so as to overlap the upper surface exposed region, and the part of the phosphor particles forms a protruding surface portion of the wavelength conversion layer.   The light emitting device according to claim 2, wherein the depression is located between the phosphor particles forming the protruding surface portion. 4. The light emitting device according to claim 1, wherein the thickness of the light scattering layer is equal to or less than an average particle diameter of the phosphor particles. 5. The light emitting device as claimed in any one of claims 1 to 4, wherein the particle size of the phosphor particles is 10μm or more. A first step of applying a coating liquid having a plurality of phosphor particles on the light emitting element and disposing the plurality of phosphor particles on the light emitting element;
After the first step, a translucent binder solution is applied on the light emitting element on which the plurality of phosphor particles are arranged to fill the space between the plurality of phosphor particles on the light emitting element. A second step of forming a wavelength conversion layer containing a plurality of phosphor particles by arranging a binder;
After the second step, a third step of forming a light scattering layer to the wavelength conversion layer, the method for manufacturing a including the light emitting device,
A part of the plurality of phosphor particles is located on a surface portion of the wavelength conversion layer, the wavelength conversion layer has a depression of the translucent binder on a surface adjacent to the part of the phosphor particles,
In the third step, the light scattering layer is formed in the depression,
The manufacturing method includes a fourth step of flattening a surface of the wavelength conversion layer including the light scattering layer after the third step . A first step of applying a coating liquid having a plurality of phosphor particles on the light emitting element and disposing the plurality of phosphor particles on the light emitting element;
  After the first step, a translucent binder solution is applied on the light emitting element on which the plurality of phosphor particles are arranged to fill the space between the plurality of phosphor particles on the light emitting element. A second step of forming a wavelength conversion layer containing a plurality of phosphor particles by arranging a binder;
  After the second step, a third step of forming a light scattering layer on the wavelength conversion layer,
The translucent binder does not contain light scattering particles,
  A part of the plurality of phosphor particles is located on a surface portion of the wavelength conversion layer, and the wavelength conversion layer is formed on the surface adjacent to the part of the phosphor particles, and the translucent binder is higher than the wavelength conversion layer. Having a recess formed by making the thickness in the range of half to 2/3, the some phosphor particles form a protruding surface portion of the wavelength conversion layer,
In the third step, the light scattering layer is formed in the depression, and the method for manufacturing a light emitting device.

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