JP2020188183A - Light-emitting device - Google Patents

Abstract

To provide a light-emitting device with high luminance including a wavelength converter that emits light having a difference in luminance from a light emitting surface.SOLUTION: A light-emitting device includes a board 11, a light emitting element that is formed on the board, and a wavelength converter 40 that is arranged on the light emitting element, performs wavelength conversion on light emitted from the light emitting element, and includes an inclined portion 42 including a bottom surface extending along the board 11, a first side surface 42A inclined outward from the bottom surface, and a second side surface 42B inclined inward from the bottom surface.SELECTED DRAWING: Figure 3

Description

The present invention relates to a light emitting device including a light emitting element such as a light emitting diode.

The light emitting device includes, for example, a substrate provided with terminals, wiring, and the like, and at least one light emitting element mounted on the substrate. For example, Patent Document 1 discloses a light emitting device having a light emitting element and a translucent member that transmits light emitted from the light emitting element and emits it to the outside.

Japanese Unexamined Patent Publication No. 2010-272847

The characteristics required for the light emitting device include, for example, high brightness, stable optical characteristics such as wavelength characteristics and light distribution characteristics, and high quality. The optical characteristics required for the light emitting device include, for example, that light of a desired wavelength (emission color) is extracted, that the wavelength of the extracted light is uniform, and that the extracted light has a desired intensity. It has characteristics (for example, having a desired intensity distribution in the light distribution region) and the like.

For example, a light emitting device that emits light having a predetermined wavelength and a wavelength converter that converts the wavelength of the light emitted from the light emitting element are combined to form a light emitting device, and light is emitted from the wavelength converter. Light of a desired wavelength can be extracted from the light emitting device. In this case, the wavelength converter is configured to emit light with desired luminance characteristics, so that light having various required optical characteristics can be extracted from the light emitting device.

Here, depending on the application, it may be required to intentionally have an intensity distribution in the light distribution region. In this case, it is preferable that the wavelength converter is configured so that, for example, a portion having high brightness and a portion having low brightness are formed in a region where light is emitted.

The present invention has been made in view of the above points, and an object of the present invention is to provide a high-luminance light emitting device having a wavelength converter that emits light having a difference in brightness from a light emitting surface.

The light emitting device according to the present invention is a substrate, a light emitting element formed on the substrate, and a wavelength converter arranged on the light emitting element and performing wavelength conversion on the light emitted from the light emitting element. It is characterized by having a bottom surface extending along it, a wavelength converter having an inclined portion having a first side surface inclined outward from the bottom surface and a second side surface inclined inward from the bottom surface.

Further, the light emitting device according to the present invention performs wavelength conversion on the substrate, the light emitting element formed on the upper surface of the substrate, and the light emitted from the light emitting element arranged on the light emitting element, and along the substrate. It has a light incident surface extending along the line and a light emitting surface facing the side opposite to the light incident surface, and a wavelength converter having the light incident surface, and the light emitting surface of the wavelength converter is viewed from a direction perpendicular to the light emitting surface. At that time, it is characterized by having a region extending outside the light incident surface.

It is a perspective view of the light emitting device which concerns on Example 1. FIG. It is a top view of the light emitting device which concerns on Example 1. FIG. It is sectional drawing of the light emitting device which concerns on Example 1. FIG. FIG. 3 is an enlarged cross-sectional view of a wavelength converter in the light emitting device according to the first embodiment. It is a figure which shows the luminance characteristic of the light emitted from the wavelength converter of the light emitting device which concerns on Example 1. FIG. It is sectional drawing of the light emitting device which concerns on Example 2. FIG. It is sectional drawing of the light emitting device which concerns on Example 3. FIG.

Hereinafter, examples of the present invention will be described in detail.

FIG. 1 is a schematic perspective view of the light emitting device 10 according to the first embodiment. A schematic configuration of the light emitting device 10 will be described with reference to FIG. In this embodiment, the light emitting device 10 includes a mounting substrate (first substrate, hereinafter simply referred to as a substrate) 11 and two light emitting elements 20 mounted on the substrate 11.

The substrate 11 has, for example, an insulating base material 11A and a wiring electrode 11B formed on the base material 11A. The substrate 11 has a mounting surface on which the light emitting element 20 is mounted. In this embodiment, the base material 11A has a flat plate shape, and has an upper surface, which is one of the main surfaces thereof, as the mounting surface. For example, the base material 11A is made of a material having high thermal conductivity, for example, AlN. The wiring electrode 11B is made of, for example, a copper film that is patterned and formed on the base material 11A.

Each of the light emitting elements 20 is a semiconductor light emitting element such as a light emitting diode. The light emitting element 20 includes, for example, a support substrate (second substrate, hereinafter simply referred to as a substrate) 21 and a semiconductor light emitting layer (hereinafter, simply referred to as a semiconductor layer) 22 supported by the substrate 21. For example, the substrate 21 has a flat plate shape and is made of Si. Further, the semiconductor layer 22 is made of, for example, a nitride semiconductor.

Further, the light emitting element 20 has a pad electrode 23 provided on the side of the semiconductor layer 22 on the substrate 21 and a back electrode provided on the surface of the substrate 21 opposite to the semiconductor layer 22 (on the substrate 11 side). 24 and. For example, the semiconductor layer 22 has an n-type semiconductor layer (not shown) and a p-type semiconductor layer (not shown). For example, the pad electrode 23 is connected to the p-type semiconductor layer of the semiconductor layer 22. Further, the back surface electrode 24 is connected to the n-type semiconductor layer of the semiconductor layer 22.

Further, in this embodiment, the pad electrode 23 is connected to the wiring electrode 11B of the substrate 11 via a bonding wire. Further, the base material 11A of the substrate 11 has vias (not shown) penetrating between the main surfaces thereof. The back surface electrode 24 is connected to a wiring electrode (not shown) provided on a surface of the base material 11A opposite to the wiring electrode 11B via the via.

In this embodiment, the light emitting element 20 has a rectangular upper surface shape. Specifically, in this embodiment, each of the substrate 21 and the semiconductor layer 22 has a rectangular upper surface shape. For example, the upper surface of the semiconductor layer 22 has a square shape with a side of about 1 mm. Further, each of the light emitting elements 20 is arranged so as to be aligned as a whole on the substrate 11 so that one side surface of each substrate 21 faces each other.

In this embodiment, the case where the light emitting device 10 has two light emitting elements 20 will be described, but the configuration of the light emitting element 20 is not limited to this. For example, the light emitting device 10 may have only one light emitting element 20, or may have three or more light emitting elements 20. Further, the upper surface shape of the light emitting element 20 is not limited to a rectangle, and may have, for example, a polygonal shape or a circular shape.

The light emitting device 10 has a wavelength converter 40 formed on the light emitting element 20 and adhered to the light emitting element 20 via an adhesive layer 30. The adhesive layer 30 is formed in a layered manner so as to embed the semiconductor layer 22 on the substrate 21 of the light emitting element 20, for example. Further, the adhesive layer 30 has translucency with respect to the light emitted from the light emitting layer 20 and the light emitted from the wavelength converter 40. For example, the adhesive layer 30 is made of a transparent resin layer.

In this embodiment, the wavelength converter 40 is formed so as to straddle between the two light emitting elements 20. For example, in this embodiment, the wavelength converter 40 covers the entire upper surface of the semiconductor layer 22 in each of the light emitting elements 20, and is integrally formed so as to straddle between the adjacent semiconductor layers 22 in the substrate 11. The wavelength converter 40 is composed of, for example, a phosphor plate formed by sintering a YAG phosphor and alumina.

The light emitting device 10 has a light reflector 50 formed on the substrate 11 and sealing the light emitting element 20 and covering a part of the wavelength converter 40. In FIG. 1, in order to illustrate the inner structure of the light reflector 50 of the light emitting device 10, only the outer edge of the light reflector 50 is shown by a broken line, and the illustration is omitted.

The light reflector 50 has reflectivity with respect to the light emitted from the light emitting element 20 and the light emitted from the wavelength converter 40. For example, the light reflector 50 is made of a resin body containing light-scattering particles (for example, titanium oxide particles).

FIG. 2 is a top view of the light emitting device 10. Further, FIG. 3 is a cross-sectional view of the light emitting device 10, and is a cross-sectional view taken along the line 3-3 in FIG. The detailed structure of the wavelength converter 40 and the light reflector 50 in the light emitting device 10 will be described with reference to FIGS. 2 and 3.

First, the light reflector 50 is formed on the substrate 11 so as to cover the wavelength converter 40 while exposing a part of the wavelength converter 40. In this embodiment, the light reflector 50 is formed on the substrate 11 so as to cover the side surface of the wavelength converter 40 while exposing the upper surface of the wavelength converter 40.

Next, the wavelength converter 40 faces the light emitting element 20 (semiconductor layer 22) via the adhesive layer 30, and the light incident surface 40P on which the light emitted from the light emitting element 20 is incident on the surface extending along the substrate 11. The wavelength is converted with respect to the light incident from the light incident surface 40P.

Further, the wavelength converter 40 has a surface not covered by the light reflector 50, and in this embodiment, an upper surface as a light emitting surface 40Q from which the light in the wavelength converter 40 is emitted. In this embodiment, the light emitting surface 40Q is a light extracting surface in the light emitting device 10. Further, in this embodiment, the light emitting surface 40Q of the wavelength converter 40 has a plane size smaller than that of the light incident surface 40P.

In this embodiment, the wavelength converter 40 has side surfaces 41A and 41B extending vertically from the substrate 11 and a bottom surface 41C functioning as a light incident surface 40P, and has a columnar portion (first columnar portion) having a columnar shape. Part) 41.

In this embodiment, the bottom surface 41C of the columnar portion 41 is entirely in contact with the adhesive layer 30 and extends along the semiconductor layer 22 (board 11). Further, in this embodiment, each of the bottom surface 41C of the columnar portion 41 and the top surface of the columnar portion 41 opposite to the bottom surface 41C has a rectangular planar shape. That is, in this embodiment, the columnar portion 41 has the shape of a quadrangular prism.

Further, the bottom surface 41C of the columnar portion 41, that is, the light incident surface 40P of the wavelength converter 40 in this embodiment has a plane size larger than that of the semiconductor layer 22. Further, in this embodiment, the adhesive layer 30 is formed on the substrate 21 so as to cover the side surface of the semiconductor layer 22.

Further, the wavelength converter 40 is formed integrally with the columnar portion 41 on the columnar portion 41 so that the upper surface of the columnar portion 41 is the bottom surface, and has the inclined portions 42A and 42B inclined with respect to the bottom surface. Has. In this embodiment, the inclined portion 42 includes a side surface (first side surface) 42A that inclines outward from the bottom surface toward the upper surface and a side surface (second side surface) 42B that inclines inward from the bottom surface toward the upper surface. Have.

In this embodiment, the side surfaces 42A and 42B of the inclined portion 42 are one and the other side surfaces facing each other among the four side surfaces formed between the rectangular bottom surface and the upper surface surface, respectively. That is, the inclined portion 42 has a side surface 42A that is inclined at an obtuse angle with respect to the bottom surface and a side surface 42B that is inclined at an acute angle with respect to the bottom surface and is opposite to the side surface 42A.

Further, in the present embodiment, the side surfaces 42A and 42B of the inclined portion 42 are surface portions extending inclined with respect to the bottom surface from two sides parallel to each other on the rectangular bottom surface of the inclined portion 42. The side surfaces 42A and 42B of the inclined portion 42 are side surface portions of the wavelength converter 40 extending from the ends of the side surfaces 41A and 41B of the columnar portion 41, respectively.

In this embodiment, each of the other two side surfaces of the inclined portion 42 extends perpendicularly to the bottom surface (not inclined). However, the configuration of the side surface of the inclined portion 42 is not limited to this. For example, all sides of the inclined portion 42 may be inclined.

Further, in this embodiment, the upper surface of the inclined portion 42 extends parallel to the bottom surface of the inclined portion 42. The upper and lower surfaces of the inclined portion 42 extend along the light incident surface 40P of the wavelength converter 40, which is the bottom surface 41C of the columnar portion 41.

Further, the wavelength converter 40 has a columnar portion (second columnar portion) 43 that is integrally formed with the inclined portion 42 on the inclined portion 42 so that the upper surface of the inclined portion 42 is the bottom surface and has a pillar shape. Have. The columnar portion 43 has side surfaces 43A and 42B extending perpendicular to the bottom surface. In this embodiment, the side surfaces 43A and 43B of the columnar portion 43 are side surface portions of the wavelength converter 40 extending from the ends of the side surfaces 42A and 42B of the inclined portion 42, respectively.

Further, in this embodiment, the upper surface 43C of the columnar portion 43 is exposed from the light reflector 50. In this embodiment, the upper surface 43C of the columnar portion 43 functions as the light emitting surface 40Q of the wavelength converter 40. Further, in this embodiment, the upper surface 43C of the columnar portion 43 is smaller than the bottom surface 41C of the columnar portion 41. That is, the wavelength converter 40 has a light emitting surface 40Q smaller than the light incident surface 40P.

In this embodiment, the wavelength converter 40 has a plate-like shape as a whole, with one main surface as the light incident surface 40P and the other main surface as the light emitting surface 40Q. Further, the side surfaces 41A and 41B of the columnar portion 41, the side surfaces 42A and 42B of the inclined portion 42, and the side surfaces 43A and 43B of the columnar portion 43 as a whole constitute the side surface of the wavelength converter 40. For example, the distance from the light incident surface 40P to the light emitting surface 40Q in the wavelength converter 40, that is, the thickness of the wavelength converter 40 is about 50 to 500 μm.

Further, in this embodiment, the side surface 41A of the columnar portion 41, the side surface 42A of the inclined portion 42, and the side surface 43A of the columnar portion 43 are continuously and integrally formed. Further, the side surface 41B of the columnar portion 41, the side surface 42B of the inclined portion 42, and the side surface 43B of the columnar portion 43 are continuously and integrally formed. That is, the side surface of each portion is in contact with the side surface of another adjacent portion at its end.

The wavelength converter 40 can be formed, for example, by cutting a phosphor plate having a main surface serving as a bottom surface 41C of the columnar portion 41 and an upper surface 43C of the columnar portion 43 in the following four steps.

For example, in the first step, a dicing blade (first blade) having a flat portion having the same shape as the side surface 41A of the columnar portion 41 and an inclined portion having the same shape as the side surface 42A of the inclined portion 42 is used. Then, the phosphor plate is cut to form a groove on one of the main surfaces of the phosphor plate (the main surface on the light incident surface 40P side). As a result, portions to be the side surfaces 41A and 42A are formed on the phosphor plate.

Next, in the second step, from the other main surface side (light emitting surface 40Q side) of the phosphor plate, the flat portion having the same shape as the side surface 43B of the columnar portion 43 and the same as the side surface 42B of the inclined portion 42. A dicing blade (second blade) on the blade surface having an inclined portion of the shape is used to cut the phosphor plate to form a groove on the other main surface of the phosphor plate. As a result, portions to be the side surfaces 43B and 42B are formed on the phosphor plate.

Next, in the third step, a blade having a blade surface perpendicular to the other main surface of the phosphor plate (third blade) was used to form the phosphor plate in the 23rd step. A recess or through hole is formed at the bottom of the groove. As a result, a portion to be the side surface 41B is formed on the phosphor plate.

Next, in the fourth step, a blade having a blade surface perpendicular to the main surface of the phosphor plate (third blade) is used to form a groove in the phosphor plate in the first step. A recess or through hole is formed at the bottom. As a result, a portion to be the side surface 43A is formed on the phosphor plate.

In addition, for example, by grinding the main surface of the other phosphor plate, the surface shape and surface quality of the bottom surface 41C of the columnar portion 41 and the upper surface 43C of the columnar portion 43 can be stabilized.

For example, the wavelength converter 40 can be manufactured in this way. The method for forming the wavelength converter 40 is not limited to this. For example, the wavelength converter 40 can also be formed by molding.

Next, the light reflector 50 seals the light emitting element 20 (the substrate 21, the semiconductor layer 22, the pad electrode 23 and the back surface electrode 24) and each wiring electrode on the substrate 11 on the substrate 11. As a result, the light emitting element 20 is electrically protected. Further, the light reflector 50 covers the side surface of the wavelength converter 40. This limits the direction of the light emitted from the wavelength converter 40.

In this embodiment, the wavelength converter 40 is adhered to the light emitting element 20 via the adhesive layer 30, and the columnar portion 41, the inclined portion 42, and the columnar portion 43 are laminated in order so as to share the upper surface and the bottom surface thereof. Has a structure. Further, the light incident surface 40P of the wavelength converter 40 has a plane size larger than that of the semiconductor layer 22. Further, the adhesive layer 30 is formed on the substrate 21 so as to cover the side surface of the semiconductor layer 22.

FIG. 4 is an enlarged cross-sectional view of the wavelength converter 40. FIG. 4 is an enlarged cross-sectional view showing a portion surrounded by the alternate long and short dash line in FIG. The configuration of the wavelength converter 40 in this embodiment will be described with reference to FIG.

First, as shown in FIG. 4, the side surface 42A of the inclined portion 42 is inclined with an inclination angle θ1 larger than 90 ° with respect to the bottom surface of the inclined portion 42. On the other hand, the side surface 42B of the inclined portion 42 is inclined with an inclination angle θ2 of less than 90 ° with respect to the bottom surface of the inclined portion 42. Further, in the present embodiment, the inclination angles θ1 and θ2 are configured to satisfy the relationship of (θ1 + θ2) <180 °.

Specifically, the angle formed by the side surface 42A and the bottom surface of the inclined portion 42 is defined as the inclination angle θ1, and the angle formed by the side surface 42B and the bottom surface is defined as the inside angle of the inclined portion 42. When the inclination angle θ2 is set, the inclination angles θ1 and θ2 satisfy the relations of θ1> 90 °, θ2 <90 °, and (θ1 + θ2) <180 °.

Further, in this embodiment, the side surface 43A of the columnar portion 43 extends vertically from the upper end portion of the side surface 42A of the inclined portion 42 to the upper surface of the columnar portion 43. Further, the side surface 43B of the columnar portion 43 extends vertically from the upper end portion of the side surface 43B of the inclined portion 42 to the upper surface of the columnar portion 43.

FIG. 5 is a diagram showing the intensity characteristics of light in the light emitting surface 40Q. The luminance characteristics of the light emitted from the wavelength converter 40 will be described with reference to FIGS. 4 and 5.

In the light emitting surface 40Q of the wavelength conversion unit 40 formed as shown in FIG. 4, the first end region P1 corresponding to the upper end portion of the side surface 43A of the columnar portion 43 is the region having the lowest brightness. On the other hand, the second end region P2 corresponding to the upper end of the side surface 43B of the columnar portion 43 on the light emitting surface 40Q is the region having the highest brightness. Further, the wavelength conversion unit 40 emits light having a characteristic that the brightness gradually increases from the first end region P1 to the second end region P2 in the light emitting surface 40Q.

More specifically, when viewed from a direction perpendicular to the light emitting surface 40Q, the first end region P1 is a region that does not overlap the light incident surface 40P. Therefore, the light incident from the light incident surface 40P is difficult to reach the first end region P1, or is reflected several times in the wavelength converter 40 and travels on a relatively long optical path before the first. Reach the end region P1 of 1. Therefore, the first end region P1 is a region having relatively low brightness in the light emitting surface 40Q.

Further, the region of the columnar portion 43 in the vicinity of the side surface 43A is provided so as to bite into the light reflector 50. Therefore, the light reflector 50 exists in the lower part of the region near the side surface 43A in the columnar portion 43.

As a result, the region near the side surface 43A of the columnar portion 43 becomes a region in the wavelength converter 40 having lower heat dissipation performance than the other regions. Therefore, when the light emitting element 20 is driven, the region near the side surface 43A of the columnar portion 43 becomes a region having a higher temperature than the other regions (a region where heat does not easily escape). Therefore, the wavelength conversion efficiency of the wavelength converter 40 in the first end region P1 becomes lower. As a result, the first end region P1 becomes a region having relatively low brightness in the light emitting surface 40Q.

On the other hand, the second end region P2 is a region that overlaps the light incident surface 40P when viewed from a direction perpendicular to the light emitting surface 40Q. Therefore, most of the light incident from the light incident surface 40P reaches the second end region P2. Further, by adjusting the inclination angle θ2 or the like, the second end region P2 can be arranged above the central region of the light incident surface 40P. As a result, the second end region P2 becomes the region having the highest brightness in the light incident surface 40Q.

Further, an inclined portion 42, which is another portion of the wavelength converter 40, is provided in the lower part of the region near the side surface 43B of the columnar portion 43. Therefore, the heat generated in the region near the side surface 43B of the columnar portion 43 easily propagates in the wavelength converter 40. Therefore, the region near the side surface 43B of the columnar portion 43 is a region having higher heat dissipation performance than other regions, and is a region having higher wavelength conversion efficiency than other regions. As a result, the second end region P2 becomes a region having a higher brightness than the other regions.

As described above, in this embodiment, the wavelength conversion valley 40 has an inclined portion 42 having a side surface 42A inclined outward from the bottom surface and a side surface 42B inclined inward. Therefore, the wavelength converter 40 is such that light having a large luminance gradient (luminance change) is emitted from the light emitting surface 40Q. Further, for example, by adjusting the inclination angles θ1 and θ2, it is possible to configure the wavelength converter 40 that emits light having stable luminance characteristics with a high degree of freedom.

Further, in the present embodiment, the inclined portion 42 is configured so that the inclination angles θ1 and θ2 satisfy the relationship of (θ1 + θ2) <180 °. As a result, the upper surface of the inclined portion 42 becomes smaller than the bottom surface of the inclined portion 42. Therefore, the wavelength converter 40 can be configured so that the light incident surface 40Q is smaller than the light incident surface 40P.

As a result, the light incident from the light incident surface 40P can be focused and emitted from the light emitting surface 40Q. Therefore, for example, after configuring the light emitting element 20 (semiconductor layer 22) having a size such that a sufficient amount of light is emitted, the light emitted from the light emitting element 20 can be collected in a region smaller than the light emitting region. it can. Thereby, for example, high-luminance light can be emitted from the light emitting surface 40Q of the wavelength converter 40.

Further, since the wavelength converter 40 has the columnar portion 41 closest to the light emitting element 20, the light emitted from the light emitting element 20 tends to stay in the wavelength converter 40. Therefore, high wavelength conversion efficiency for the light emitted from the light emitting element 20 can be maintained.

Further, when the light is incident on the columnar portion 41 having a uniform thickness, the in-plane wavelength conversion unevenness of the columnar portion 41 is suppressed. Therefore, it is possible to suppress in-plane intensity unevenness and color unevenness of the columnar portion 41 in the light directed from the columnar portion 41 to the inclined portion 42.

Further, since the wavelength converter 40 has the columnar portion 43 on the inclined portion 42, the amount of light whose wavelength is converted in the inclined portion 42 or the light propagating through the inclined portion 42 is stabilized in the plane of the columnar portion 43. Can be made to. Therefore, the luminance distribution formed in the inclined portion 42 can be maintained even on the light emitting surface 40Q.

In this embodiment, the wavelength converter 40 has a rectangular upper surface shape. As a result, it is possible to obtain light distribution characteristics having a shape that can be easily applied to various applications. For example, the light emitting device 10 can form a vehicle lamp. Specifically, the vehicle lamp is a lamp that is required to form a high brightness region and a low brightness region in the irradiation region. Therefore, by using the wavelength converter 40, such light distribution characteristics can be easily obtained. For example, when the wavelength converter 40 has a rectangular upper surface shape, the configuration is suitable for, for example, such an application, that is, a lighting application.

The configuration of the wavelength converter 40 described above is only an example. For example, in this embodiment, the case where the wavelength converter 40 has the columnar portion 41, the inclined portion 42, and the columnar portion 43 formed integrally has been described. Further, a case where the shapes of the upper surface and the lower surface of the vertically adjacent portions match has been described. However, the wavelength converter 40 may have, for example, a columnar portion 41, an inclined portion 42, and a columnar portion 43 formed so as to be separable from each other. Further, the upper surface and the lower surface of the vertically adjacent portions may be optically coupled to each other, and their shapes may not match or may be separated from each other.

Further, in this embodiment, a case where the inclined side surfaces 42A and 42B are arranged so as to face each other in the inclined portion 42 of the wavelength converter 40 has been described. However, the side surface shape of the inclined portion 40 is not limited to this. For example, the inclined portion 42 may have one of two rectangular side surfaces orthogonal to each other as the side surface 42A and the other side surface as the side surface 42B. That is, the inclined portion 42 may have side surfaces 42A and 42B which are inclined adjacent to each other.

Further, in this embodiment, the case where the light reflector 50 covering the side surface of the wavelength converter 40 is formed on the substrate 11 has been described. However, the light reflector 50 may not be provided.

For example, the side surface of the wavelength converter 40 has a certain degree of reflection function even when it is optically exposed. This is because, for example, the light incident on the side surface from the inside of the wavelength converter 40 stays in the wavelength converter 40 due to total reflection, for example. Further, by making the bottom surface or the upper surface relatively large with respect to the side surface of the wavelength converter 40, such as forming the wavelength converter 40 in a plate shape as in this embodiment, most of the light is emitted from the light emitting surface 40Q. Exit. Therefore, even if the light reflector 50 is not provided, the luminance characteristic and the light distribution characteristic of the light emitted from the wavelength converter 40 can be maintained.

As described above, in this embodiment, the light emitting device 10 refers to the substrate 11, the light emitting element 20 formed on the substrate 11, and the light emitted from the light emitting element 20 arranged on the light emitting element 20. It has a wavelength converter 40 that performs wavelength conversion, and a light reflector 50 that covers the side surface of the wavelength converter 40.

Further, in the present embodiment, the wavelength converter 40 is formed and inclined on the columnar portion 41 having a bottom surface 41C forming a light incident surface 40P on which the light emitted from the light emitting element 20 is incident. It has an inclined portion 42 having a side surface 42A and a side surface 42B, and a columnar portion 43 having an upper surface 43C formed on the inclined portion 42 and forming a light emitting surface 40Q from which light is emitted to the outside. Therefore, it is possible to provide a high-luminance light emitting device 10 having a wavelength converter 40 that emits light having a difference in brightness from the light emitting surface 40Q.

FIG. 6 is a cross-sectional view of the light emitting device 10A according to the second embodiment. The light emitting device 10A has the same configuration as the light emitting device 10 except for the configuration of the wavelength converter 40A. The wavelength converter 40A has the same configuration as the wavelength converter 40 except that it is composed of only the inclined portion 42. In this embodiment, the wavelength converter 40A has a configuration corresponding to the case where the columnar portions 41 and 43 are removed from the wavelength converter 40.

In this embodiment, the bottom surface 42C of the inclined portion 42 is in contact with the adhesive layer 30. Further, the bottom surface 42C of the inclined portion 42 functions as a light incident surface 40P in the wavelength converter 40B. Further, the upper surface 42D of the inclined portion 42 is exposed from the light reflector 50. The upper surface 42D of the inclined portion 42 functions as a light emitting surface 40Q of the wavelength converter 40A.

As in this embodiment, the wavelength converter 40A may have at least an inclined portion 42. Since the wavelength converter 40A has the inclined portion 42, it is possible to form an inclined brightness in the plane of the light emitting surface 40Q.

In other words, in the present embodiment, the light emitting device 10A refers to the substrate 11, the light emitting element 20 formed on the substrate 11, and the light emitted from the light emitting element 20 arranged on the light emitting element 20. A wavelength converter 40 that performs wavelength conversion and has a bottom surface extending along the substrate 11, a side surface 42A that inclines at an obtuse angle with respect to the bottom surface, and a side surface 42B that inclines at an acute angle with respect to the bottom surface. It has a wavelength converter 40 having a part 42, and a wavelength converter 40. Therefore, it is possible to provide a high-luminance light emitting device 10A having a wavelength converter 40A that emits light having a difference in brightness from the light emitting surface 40Q.

FIG. 7 is a cross-sectional view of the light emitting device 10B according to the third embodiment. The light emitting device 10B has the same configuration as the light emitting device 10 except for the configuration of the wavelength converter 40B. The wavelength converter 40B has a wavelength converter 44, and a columnar portion 41T, an inclined portion 42T, and a columnar portion 43T provided on the wavelength converter plate 44 and having translucency.

In this embodiment, the wavelength converter 40B has side surfaces 44A and 44B extending perpendicular to the substrate 11 and a bottom surface 44C forming the light incident surface 40P, and wavelength-converts the light emitted from the light emitting element 20. It has a wavelength conversion unit 44 that performs the above. Further, the wavelength converter 40B has only a light transmitting function in other parts of the wavelength converter 44.

Specifically, in Example 1 described above, the case where the wavelength converter 40 is composed of an integrally formed phosphor plate and has a wavelength conversion function as a whole has been described. However, the configuration of the wavelength converter 40 is not limited to this.

For example, the wavelength converter 40 may include a phosphor plate and a translucent plate formed on the phosphor plate. That is, the wavelength converter 40 may have a structure in which a plurality of members are combined, or may have a member having a wavelength conversion function only in a part thereof.

In this embodiment, the wavelength converter 40B corresponds to a case where only the portion of the columnar portion 41 on the columnar portion 41 on the substrate 11 side of the wavelength converter 40 is configured as the wavelength converter and the other portions are configured as the translucent portion. Has a configuration.

As in this embodiment, the wavelength converter 40B may have a wavelength conversion function at least only a part thereof. Even in this case, it is possible to form the wavelength converter 40B capable of emitting light having a desired wavelength after providing a desired luminance distribution.

Depending on the configuration of the light emitting element 20 and the application of the light emitting device 10, the entire wavelength converter 40 may not have the wavelength conversion function. For example, when it is used for communication or analysis using only monochromatic (single wavelength) light, the light emitted from the light emitting element 20 may be taken out while maintaining its wavelength characteristics. In this case, the wavelength converter 40 does not need to have a wavelength conversion function, and may function as a simple translucent body, for example. Even in this case, if the translucent body has a configuration as described in various examples as described above, it is possible to emit light having a desired luminance difference.

As described above, in this embodiment, for example, the wavelength converter 40B has a pillar-shaped wavelength converter 44 having a bottom surface forming the light incident surface 40P. Further, the columnar portion 41T, the inclined portion 42T, and the columnar portion 43T of the wavelength converter 40B have translucency with respect to the light generated by the light emitting element 20 and the wavelength converter 44. Therefore, it is possible to provide a high-luminance light emitting device 10B having a wavelength converter 40B that emits light having a difference in brightness from the light emitting surface 40Q.

Considering that the light emitting surface 40Q of the wavelength converter 40B is provided with a brightness gradient, the wavelength converter 40B does not need to have the above-mentioned shape. For example, as shown in FIG. 2, the light emitting surface 40Q of the wavelength converter 40B may have a region extending outside the light incident surface 40P when viewed from a direction perpendicular to the light emitting surface 40Q. Just do it. As a result, the region of the light emitting surface 40Q displaced to the outside of the light incident surface 40P becomes a region having low brightness, and a brightness inclination can be provided as a whole.

In other words, for example, the light emitting device 10B has a wavelength with respect to the substrate 11, the light emitting element 20 formed on the upper surface of the substrate 11, and the light disposed on the light emitting element 20 and emitted from the light emitting element 20. The light of the wavelength converter 40, which has a wavelength converter 40B having a light incident surface 40P extending along the substrate 11 and a light emitting surface 40Q facing the side opposite to the light incident surface 40P after conversion. The exit surface 40Q may have a region extending outside the light incident surface 40P when viewed from a direction perpendicular to the light emission surface 40Q. Therefore, it is possible to provide a high-luminance light emitting device 10B having a wavelength converter 40B that emits light having a difference in brightness from the light emitting surface 40Q.

10, 10A, 10B light emitting device 20 light emitting element 40, 40A, 40B wavelength converter

Claims (6)

With the board
The light emitting element formed on the substrate and
A wavelength converter that is arranged on the light emitting element and performs wavelength conversion on the light emitted from the light emitting element, and has a bottom surface extending along the substrate, a first side surface inclined outward from the bottom surface, and the like. A light emitting device comprising a wavelength converter having an inclined portion having a second side surface inclined inward from the bottom surface. Of the angles formed by the first side surface and the bottom surface of the inclined portion, the angle inside the inclined portion is defined as the inclination angle θ1, and the inside of the inclined portion among the angles formed by the second side surface and the bottom surface. The light emitting device according to claim 1, wherein the inclination angles θ1 and θ2 satisfy the relationship of (θ1 + θ2) <180 °, where the angle of tilt is θ2. The wavelength converter has a bottom surface forming a light incident surface on which light emitted from the light emitting element is incident, a first columnar portion having a top surface corresponding to the bottom surface of the inclined portion and having a pillar shape, and the above-mentioned It is characterized by having a bottom surface corresponding to the upper surface of the inclined portion and a second columnar portion having a pillar shape and having an upper surface forming a light emitting surface from which light having the wavelength converted is emitted to the outside. The light emitting device according to claim 1 or 2. The wavelength converter has a bottom surface forming a light incident surface on which light emitted from the light emitting element is incident, has a pillar shape, and has a wavelength conversion unit that performs the wavelength conversion.
The light emitting device according to any one of claims 1 to 3, wherein the inclined portion has translucency with respect to the light generated by the light emitting element and the wavelength conversion unit. One of claims 1 to 4, wherein the light emitting element and a light reflector having a reflectivity to light generated by the wavelength converter are provided, which covers the side surface of the wavelength converter. The light emitting device described. With the board
A light emitting element formed on the upper surface of the substrate and
A light incident surface that is arranged on the light emitting element and undergoes wavelength conversion on the light emitted from the light emitting element, extends along the substrate, and a light emitting surface that faces the side opposite to the light incident surface. With a wavelength converter,
A light emitting device, characterized in that the light emitting surface of the wavelength converter has a region extending outside the light incident surface when viewed from a direction perpendicular to the light emitting surface.

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