WO2013108601A1 - Light-emitting device - Google Patents

Light-emitting device Download PDF

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Publication number
WO2013108601A1
WO2013108601A1 PCT/JP2013/000086 JP2013000086W WO2013108601A1 WO 2013108601 A1 WO2013108601 A1 WO 2013108601A1 JP 2013000086 W JP2013000086 W JP 2013000086W WO 2013108601 A1 WO2013108601 A1 WO 2013108601A1
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WO
WIPO (PCT)
Prior art keywords
light
light emitting
wavelength conversion
conversion layer
emitting device
Prior art date
Application number
PCT/JP2013/000086
Other languages
French (fr)
Japanese (ja)
Inventor
正宣 水野
康章 堤
伊藤　和弘
孝 大西
Original Assignee
株式会社小糸製作所
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Application filed by 株式会社小糸製作所 filed Critical 株式会社小糸製作所
Publication of WO2013108601A1 publication Critical patent/WO2013108601A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/48—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor body packages
    • H01L33/58—Optical field-shaping elements
    • H01L33/60—Reflective elements
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/10—Bump connectors; Manufacturing methods related thereto
    • H01L2224/15—Structure, shape, material or disposition of the bump connectors after the connecting process
    • H01L2224/16—Structure, shape, material or disposition of the bump connectors after the connecting process of an individual bump connector
    • H01L2224/161—Disposition
    • H01L2224/16151—Disposition the bump connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive
    • H01L2224/16221—Disposition the bump connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked
    • H01L2224/16225—Disposition the bump connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being non-metallic, e.g. insulating substrate with or without metallisation
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/48—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor body packages
    • H01L33/50—Wavelength conversion elements
    • H01L33/501—Wavelength conversion elements characterised by the materials, e.g. binder
    • H01L33/502—Wavelength conversion materials

Definitions

  • the present invention relates to a light emitting device, and more particularly, to a light emitting device including a semiconductor light emitting element and a light wavelength conversion member disposed to face the light emitting surface of the semiconductor light emitting element.
  • a vehicular lamp in which a plurality of LEDs are controlled to be turned on and off to form an irradiation pattern selected from the plurality of irradiation patterns.
  • a planar integrated light source having planarly arranged LEDs on the surface, a mask having an opening for exposing the light emitting part, and an opening of the mask are filled.
  • a vehicular lamp including a phosphor has been proposed (see, for example, Patent Document 3).
  • an electrode may be formed on the light emitting surface.
  • LEDs have high directivity, and therefore, the electrode shape of the light emitting surface may also appear as luminance unevenness.
  • the present invention has been made to solve the above-described problems, and an object of the present invention is to reduce luminance unevenness due to a partition frame provided between a plurality of light emitting elements or electrodes provided on a light emitting surface. It is in.
  • a light-emitting device is provided to face a light-emitting surface of each of a plurality of semiconductor light-emitting elements and a partition frame that partitions the plurality of semiconductor light-emitting elements arranged in parallel.
  • the light wavelength conversion layer has a transmittance of the converted secondary light (for example, yellow light) of 60% or more, and is emitted at a predetermined angle or more with respect to the optical axis of the semiconductor light emitting element among the entire light emitted from the light wavelength conversion layer.
  • the diffusion rate which is the ratio of diffused light, is 80% or more.
  • the luminance reduction due to the partition frame can be appropriately suppressed by setting the transmittance to 60% or more and the diffusivity to 80% or more. Therefore, according to this aspect, it is possible to suppress luminance unevenness in a light emitting device in which a plurality of semiconductor light emitting elements are arranged in parallel.
  • the partition frame may be formed so that the thickness decreases as it approaches the end, and the light wavelength conversion layer may be disposed in contact with the surface of the partition frame in the vicinity of the end of the partition frame.
  • the light wavelength conversion layer can be extended so as to reach the range in which the partition frame is provided when viewed from above, and the luminance reduction of the partition frame portion can be suppressed.
  • light can be reflected toward the emission surface of the light wavelength conversion layer at the end of the partition frame, and the light extraction efficiency can be improved.
  • the partition frame may have a reflectance of 70% or more on at least a part of its surface.
  • the light wavelength conversion layer may have a thickness of 30 ⁇ m or more and 5000 ⁇ m or less. According to this aspect, luminance unevenness can be suppressed while avoiding cracking of the light wavelength conversion layer.
  • Another embodiment of the present invention is also a light emitting device.
  • This device includes a semiconductor light emitting element having an electrode formed on a light emitting surface, and an optical wavelength conversion layer disposed to face the light emitting surface.
  • the light wavelength conversion layer has a transmittance of the converted secondary light (for example, yellow light) of 60% or more, and is emitted at a predetermined angle or more with respect to the optical axis of the semiconductor light emitting element among the entire light emitted from the light wavelength conversion layer.
  • the diffusion rate which is the ratio of diffused light, is 80% or more.
  • the light wavelength conversion layer may have a thickness of 30 ⁇ m or more and 5000 ⁇ m or less.
  • the present invention it is possible to reduce luminance unevenness due to a partition frame provided between a plurality of light emitting elements or electrodes provided on a light emitting surface.
  • FIG. 2 is a sectional view taken along the line PP in FIG. 1.
  • (A) And (b) is a figure which shows the measurement system of a spreading
  • (A) is a figure which shows the relationship between the transmittance
  • (B) is a figure which shows the result in each test of the light-emitting device which concerns on the comparative example 1, the comparative example 2, and an Example.
  • (A) is a figure which shows a brightness nonuniformity when it measures only with a light emitting element.
  • (B) is a figure which shows the light emission surface of a light emitting element when the width
  • (A) is a figure which shows the brightness nonuniformity in a light emitting element when it measures using each of the light wavelength conversion layer which concerns on an Example, and the light wavelength conversion layer which concerns on the comparative example 1.
  • FIG. (B) is a figure which shows the light emission surface of a light emitting element when the width
  • FIG. (A) is a figure which shows the brightness nonuniformity between light emitting elements when it measures using each of the light wavelength conversion layer which concerns on an Example, and the light wavelength conversion layer which concerns on the comparative example 2.
  • FIG. (B) is a top view of the light emitting device when the width of the light emitting device is adjusted to the horizontal axis of (a) for easy understanding.
  • (A) is a figure which shows the relationship between the transmittance
  • (B) is a figure which shows the result in each test of the light-emitting device which concerns on the comparative example 3 and an Example.
  • (A) shows the transmittance, the diffusivity, and the reflectance of the frame surface of the light wavelength conversion layer according to Comparative Example 4-1, Comparative Example 4-2, Example 4-1, and Example 4-1. It is a figure which shows a relationship.
  • (B) is a figure which shows the result in each test of the light-emitting device which concerns on the comparative example 4-1, comparative example 4-2, Example 4-1, and Example 4-2.
  • FIG. 1 is a top view of the light emitting device 10 according to the present embodiment.
  • 2 is a cross-sectional view taken along the line PP in FIG.
  • the configuration of the light emitting device 10 will be described with reference to both FIG. 1 and FIG.
  • the light emitting device 10 includes a light emitting element 20, a light wavelength conversion layer 30, a mounting substrate 40, and a frame 50.
  • the light emitting element 20 has a rectangular light emitting surface 20a and four side surfaces 20b that are in contact with the light emitting surface 20a at right angles.
  • the light emitting surface 20a and the side surface 20b may contact each other at an angle other than a right angle.
  • the mounting substrate 40 is formed in a flat plate shape using a material having high thermal conductivity such as AlN.
  • a plurality of light emitting elements 20 are mounted on the upper surface 40a of the mounting substrate 40 such that each light emitting surface 20a is parallel to the upper surface 40a.
  • the mounting substrate 40 has an area where the plurality of light emitting elements 20 can be mounted.
  • the plurality of light emitting elements 20 are arranged in a row so as to be separated from each other.
  • a plurality of mounting boards 40 may be arranged side by side on a plane, such as a plurality of mounting boards 40 arranged side by side to form a plurality of rows.
  • the light emitting element 20 is constituted by an LED element which is a semiconductor light emitting element.
  • a blue LED that mainly emits light having a blue wavelength is employed as the light emitting element 20.
  • the light emitting element 20 is configured by an InGaN LED element formed by crystal growth of an InGaN semiconductor layer.
  • the material for forming the light emitting element 20 is not limited to this, and may be any one of InN, AlGaN, and AIN, for example.
  • the light emitting element 20 is a so-called flip chip type. For this reason, the light emitting element 20 has an electrode 20c formed on the light emitting surface 20a. Note that a so-called face-up type or vertical chip type light emitting element 20 may be employed.
  • An electrode (not shown) is provided on the upper surface 40a of the mounting substrate 40, and the back surfaces of the plurality of light emitting elements 20 are connected to the electrodes through Au bumps. This electrode connects each of the plurality of light emitting elements 20 and the power supply to each other via a switching circuit so that a current can be independently supplied to each of the plurality of light emitting elements 20. Thereby, it becomes possible to perform lighting control and light control of each of the plurality of light emitting elements 20 independently.
  • the electrodes provided on the upper surface 40a may be provided so as to electrically connect the plurality of light emitting elements 20 in series or in parallel so that power can be supplied to the plurality of light emitting elements 20 simultaneously.
  • the four light emitting elements 20 are arranged in a row adjacent to each other so that their edges are parallel to each other.
  • the number of the light emitting elements 20 is not limited to four. Further, the light emitting elements 20 may be arranged in a plurality of rows.
  • the light emitting device 10 is used as a light source for a vehicle headlamp.
  • the use of the light emitting device 10 is not limited to this.
  • the light emitting device 10 is arranged such that the light emitting surfaces of the four light emitting elements 20 are positioned on the rear focal plane of the projection lens.
  • the light emitting element 20 is formed as a 1 mm square chip, for example, and is provided so that the center wavelength of the emitted blue light is 470 nm.
  • the configuration of the light-emitting element 20 and the wavelength of emitted light are not limited to those described above, and the light-emitting element 20 may mainly emit light having a wavelength other than blue.
  • the light emitting device 10 is used as a light source for providing a non-irradiation region in a light distribution pattern by the light emitting device 10 by turning off any of the plurality of light emitting elements 20.
  • the light emitting element 20 including the object in the light distribution pattern is turned off.
  • the periphery of the object is set as a non-irradiated region, and the application of glare is suppressed.
  • the light emitting element 20 is turned off, it is desirable that the region of the light distribution pattern formed by the light emitting element 20 is a non-irradiated region.
  • the performance of the light emitting device 10 indicating how much the light emitting area of the adjacent light emitting element 20 is not affected is referred to as “individual dimming performance”.
  • the light emitting device 10 is provided with a frame 50.
  • the frame 50 includes an outer frame 50a and a partition frame 50b.
  • the outer frame 50a is formed in a rectangular frame shape, and the cross section is formed in a square shape.
  • the outer frame 50 a is placed on the upper surface 40 a of the mounting substrate 40 so as to surround all of the plurality of light emitting elements 20, and the lower surface is bonded to the upper surface 40 a and fixed to the mounting substrate 40.
  • the outer frame 50a has an inclined surface 50c on the inner surface of the frame.
  • the inclined surface 50c is adjacent to any side surface 20b of the plurality of light emitting elements 20 arranged in a line.
  • the partition frame 50b is formed in a pentagonal prism shape including a pair of inclined surfaces 50c and a pair of vertical surfaces 50d.
  • the partition frame 50 b is fixed to the mounting substrate 40 with the lower surface bonded to the upper surface 40 a.
  • the partition frame 50b is disposed so as to partition the plurality of light emitting elements 20 arranged in parallel.
  • the partition frame 50b By providing the partition frame 50b, the light emitting regions of the plurality of light emitting elements 20 can be partitioned. For this reason, when the adjacent one light emitting element 20 is caused to emit light, the light traveling to the light emitting region of the other light emitting element 20 that is turned off can be suppressed.
  • the inventor conducted experiments on individual dimming performance when the partition frame 50b was provided and when the partition frame 50b was deleted. As a result, when there is no partition frame 50b, when one of the adjacent light emitting elements 20 is caused to emit light, a large amount of light travels to the light emitting region of the other light emitting element 20 that is turned off, and the individual dimming performance is low. There was found. On the other hand, it was confirmed that the individual dimming performance is remarkably enhanced by providing the partition frame 50b.
  • the inclined surface 50c is inclined so as to expand as it proceeds in the light emitting direction of the light emitting element 20, that is, in the main optical axis direction of the light emitting element 20.
  • the inclined surface 50c is inclined so as to be separated from the plane including the adjacent side surface 20b as it approaches the upper surface of the outer frame 50a.
  • Each of the pair of vertical surfaces 50d is in contact with the adjacent inclined surface 50c and extends perpendicularly to the light emitting surface 20a and the upper surface 40a at a position farther from the light wavelength conversion layer 30 than the inclined surface 50c.
  • the partition frame 50b and the side surface 20b of the light emitting element 20 can be brought close to each other even between a pair of light emitting elements 20 adjacent to each other. Can be suppressed.
  • the vertical surface 50d has a slightly lower height than the light emitting surface 20a, that is, a height close to the upper surface 40a of the mounting substrate 40.
  • the vertical surface 50d may have the same height as the height from the upper surface 40a of the mounting substrate 40 to the light emitting surface 20a. Further, the vertical surface 50d may have a height higher than the height from the upper surface 40a of the mounting substrate 40 to the light emitting surface 20a.
  • the partition frame 50b includes a pair of light wavelength conversion layers that are opposed to the pair of light emitting elements 20 from between the pair of light emitting elements 20 so as to partition a pair of adjacent light emitting elements 20 among the plurality of light emitting elements 20. It extends between 30. Since the light emitting elements 20 are arranged in a line, the number of the partition frames 50 b is one less than the number of the light emitting elements 20. In this embodiment, since four light emitting elements 20 are provided, three partition frames 50b are provided. Even when the plurality of light emitting elements 20 are arranged side by side so as to form a plurality of rows, the partition frame 50b is disposed between the pair of light emitting elements 20 adjacent to each other.
  • the outer frame 50a and the partition frame 50b are integrally formed of silicon.
  • the upper surface of the outer frame 50a and the top of the partition frame 50b are at the same height.
  • the inclined surface 50c is inclined at an angle of 54.7 ° with respect to the upper surface of the outer frame 50a.
  • the outer frame 50a and the partition frame 50b can be formed with an accurate inclination angle.
  • the surface can be easily smoothed, and high reflection efficiency can be realized.
  • the outer frame 50a and the partition frame 50b may be formed of a material other than silicon.
  • the inclination angle of the inclined surface 50c with respect to the upper surface of the outer frame 50a may be not less than 20 ° and not more than 70 °.
  • a reflective film whose reflectance is increased by depositing aluminum or silver is provided on the surfaces of the outer frame 50a and the partition frame 50b.
  • the inventor conducted experiments on individual light control performance and luminance unevenness between the light emitting elements 20 when the inclined surface 50c is provided and when the inclined frame 50c is not provided and the partition frame 50b reaches the upper end with the same width. .
  • both dimming performances met the standard.
  • the luminance unevenness between the light emitting elements 20 satisfied the standard when the inclined surface 50c was provided, but did not satisfy the standard when the inclined surface 50c was not provided. For this reason, it was confirmed that uneven luminance between the light emitting elements 20 can be suppressed by providing the inclined surface 50c.
  • a plurality of light wavelength conversion layers 30 are provided corresponding to each of the plurality of light emitting elements 20.
  • the light wavelength conversion layer 30 is provided to face the light emitting surface 20 a of the corresponding light emitting element 20.
  • the light wavelength conversion layer 30 is formed by filling the region after the light emitting element 20 is mounted in a region defined by the four inclined surfaces 50c and the four vertical surfaces 50d. For this reason, the partition frame 50b is formed so that the thickness decreases as it approaches the end.
  • the light wavelength conversion layer 30 is disposed in contact with the surface of the partition frame 50b in the vicinity of the end of the partition frame 50b. In this embodiment, the light wavelength conversion layer 30 is formed up to the upper end of the frame 50. For this reason, the distance between the adjacent optical wavelength conversion layers 30 can be suppressed.
  • the light wavelength conversion layer 30 converts the wavelength of the light emitted from the opposing light emitting elements 20 and emits the light.
  • the light wavelength conversion layer 30 is a so-called phosphor layer, and is formed by mixing a phosphor with a transparent resin binder.
  • the light wavelength conversion layer 30 converts the wavelength of the blue light emitted from the light emitting element 20 and emits yellow light. For this reason, the light emitting device 10 emits white light that is a combined light of the blue light that has passed through the light wavelength conversion layer 30 and the yellow light that has been wavelength-converted by the light wavelength conversion layer 30 and emitted.
  • the inclined surface 50 c By providing the inclined surface 50 c on the frame 50, the light emitted from the side surface 20 b of the light emitting element 20 or the light emitted from the light emitting surface 20 a at an angle close to horizontal is reflected toward the emission surface 30 a of the light wavelength conversion layer 30. can do. For this reason, the light emitted from the side surface 20b can also be used effectively, and the brightness and luminous intensity of the light emitted from the light emitting device 10 can be increased as compared with the case where the inclined surface 50c is not provided. Moreover, even when a plurality of light emitting elements 20 are mounted, it is possible to suppress the occurrence of a low luminance portion between a pair of adjacent light wavelength conversion layers 30.
  • the inventor conducted an experiment on individual dimming performance with and without the inclined surface 50c on the frame 50. As a result, it has been found that in the absence of the inclined surface 50c, the luminance in the region between the adjacent light emitting elements 20 is greatly reduced. On the other hand, when the inclined surface 50c was provided, it was confirmed that the brightness
  • the diffusivity can be adjusted. .
  • the diffusivity can be changed by adding a substance having a refractive index different from that of the matrix component constituting the light wavelength conversion layer 30.
  • the surface of the light wavelength conversion layer 30 may be processed to change its shape, or the light diffusion layer may be formed on the surface of the light wavelength conversion layer 30 to change the diffusivity.
  • the diffusivity may be changed by adding a particle component having a refractive index different from that of the main component forming the light wavelength conversion layer 30.
  • the phosphor particles are added to the transparent resin binder.
  • the refractive index of the transparent resin and the refractive index of the phosphor particles are different, the phosphor is refracted by adding the phosphor particles to the transparent resin.
  • the rate has also changed.
  • particles other than the phosphor particles may be added to the transparent resin. Examples of such particles include bubbles and voids due to gas components such as air and nitrogen in addition to silica and alumina.
  • the phase can be adjusted by the ratio as long as the refractive index is different.
  • the diffusivity can be adjusted by the ratio of the amorphous phase in the translucent resin such as polypropylene, the ratio of the rutile phase and the anatase phase in the case of inorganic titanium oxide, and the ratio of the garnet phase and the perovskite phase in the alumina-yttria eutectic system. .
  • the shape processing on the surface of the light wavelength conversion layer 30 may be controlled processing such as a microlens or a random method using a blast method or the like.
  • the processing method may be mechanical processing such as polishing and grinding, or chemical processing such as chemical etching, in addition to molding using a mold.
  • a method for forming a light diffusion layer on the surface of the phosphor layer for example, there is a method in which an acrylic transparent resin containing silica particles is applied to the phosphor surface layer. By increasing the thickness, a self-supporting diffusion plate may be installed.
  • FIG. 3 (a) and 3 (b) are diagrams showing the diffusivity measurement system 100.
  • the measurement system 100 includes a light emitting device 10, an integrating sphere light receiver 102, a photometer 104, and a white plate 106.
  • As the integrating sphere light receiver 102 a SolidSpec-3700 integrating sphere light receiver manufactured by Shimadzu Corporation was used.
  • the integrating sphere light receiver 102 has an entrance port 102a, an exit port 102b, and a measurement port 102c, and a reflective film is provided on the other inner surface. This reflective film not only has a high reflectance, but also has a high diffusibility.
  • the light emitted into the integrating sphere light receiver 102 is repeatedly reflected on the inner surface of the integrating sphere light receiver 102, thereby showing a uniform light intensity distribution on the entire inner surface. Since the structure of the integrating sphere light receiver 102 is known, further description is omitted.
  • the center of the entrance 102a and the exit 102b are located on the same straight line passing through the center of the integrating sphere light receiver 102 and are in a positional relationship facing each other.
  • the white plate 106 is attached to the emission port 102b with an inclination of 10 °. As a result, light incident from the opposite incident port 102a is prevented from being emitted from the integrating sphere light receiver 102 again.
  • the light wavelength conversion layer 30 is disposed at a position slightly away from the incident port 102a. Into the light wavelength conversion layer 30, the light split to the same wavelength as that of the converted secondary light is incident, and the transmitted light is measured by the integrating sphere light receiver 102. Thus, the influence of the light wavelength conversion layer 30 absorbing the primary light can be excluded by selecting the wavelength of the incident light.
  • total light the light transmitted through the light wavelength conversion layer 30 is referred to as “total light”.
  • the integrating sphere light receiver 102 can measure “total light”.
  • the entrance port 102a and the exit port 102b are required to have the same aperture diameter, and in this embodiment, each has an aperture diameter of ⁇ 20.
  • the white plate 106 disposed at the exit port 102b is removed, “straight light” exits the integrating sphere from the exit port 102b. The remaining “diffused light” is reflected in the integrating sphere and measured by the integrating sphere receiver 102.
  • the measurement port 102c is provided on the surface of the integrating sphere light receiver 102 which is separated from the entrance port 102a and the exit port 102b.
  • a photometer 104 is attached to the measurement port 102c. Since the luminous intensity distribution on the inner surface of the integrating sphere light receiver 102 is uniform, the photometer 104 detects the uniform average luminous intensity.
  • FIG. 3 (a) shows the measurement system 100 when measuring the average luminous intensity of the whole light.
  • the ratio and transmittance of light having a wavelength of 600 nm transmitted through the optical wavelength conversion layer 30 were measured with the photometer 104.
  • the emission port 102 b is shielded by the white plate 106.
  • the white plate 106 is made of barium sulfate.
  • the exit port 102b is shielded by the white plate 106, the luminous intensity of light having a wavelength of 600 nm is measured by the photometer 104, and the luminous intensity at this time is taken as 100.
  • the light wavelength conversion layer 30 is installed in front of the entrance 102 a in the middle of the optical path of the measurement system 100, and the light intensity is similarly measured by the photometer 104. The luminous intensity at this time was compared with the first measured luminous intensity as 100, and the relative value was defined as the transmittance of “total light”.
  • FIG. 3A the light wavelength conversion layer 30 is installed in front of the entrance 102 a in the middle of the optical path of the measurement system 100, and the light intensity is similarly measured by the photometer 104.
  • the luminous intensity at this time was compared with the first measured luminous intensity as 100, and the relative value was defined as the transmittance of “total light”.
  • the white plate 106 at the emission port 102b is removed, and the luminous intensity is measured by the photometer 104 in the same manner.
  • the light intensity at this time was compared with the light intensity measured first as 100, and the relative value was defined as the transmittance of “diffuse light”.
  • the luminance of the light emitting device 10 was measured using a luminance meter. A current of 850 mA was applied to the light emitting device 10 to light it for 10 minutes, and measurement was performed at a viewing angle of 0.2 ° using a luminance meter (SR-30 manufactured by Topcon Technohouse Co., Ltd.). And the brightness
  • FIG. 4A is a diagram showing the relationship between the transmittance and the diffusivity of the optical wavelength conversion layer 30 according to Comparative Example 1, Comparative Example 2, and Examples.
  • the above-described light emitting device 10 was used in common in Comparative Example 1, Comparative Example 2, and Examples, except that the transmittance or diffusivity of the light wavelength conversion layer 30 was different. Therefore, a partition frame 50b that partitions the plurality of light emitting elements 20 arranged side by side is provided, and a plurality of electrodes 20c are provided on the light emitting surface 20a of the light emitting element 20.
  • the transmittance of the light wavelength conversion layer 30 is 60% and the diffusivity is 70%.
  • the transmittance of the light wavelength conversion layer 30 is 50%, and the diffusivity is 80%.
  • the transmittance of the light wavelength conversion layer 30 is 60% and the diffusivity is 80%.
  • the optical wavelength conversion layer 30 according to Comparative Example 1 has a low diffusivity compared to the optical wavelength conversion layer 30 according to the example.
  • the light wavelength conversion layer 30 according to Comparative Example 2 has a lower transmittance than the light wavelength conversion layer 30 according to the example.
  • FIG. 4B is a diagram showing the results of each test of the light emitting device 10 according to Comparative Example 1, Comparative Example 2, and Example. Using the light emitting device 10 according to Comparative Example 1, Comparative Example 2, and Example, each of individual dimming performance, luminance unevenness between the light emitting elements 20, luminance unevenness in the light emitting elements 20, and high brightness The items were tested to see if they met the prescribed criteria.
  • the luminance unevenness between the light emitting elements 20 was determined whether or not the difference between the maximum luminance and the minimum luminance in the region between the light emitting surfaces 20a of the two adjacent light emitting elements 20 satisfies a predetermined criterion.
  • the luminance unevenness in the light emitting element 20 it was determined whether or not the difference between the maximum luminance and the minimum luminance in the projection area of the light emitting surface 20a of the light emitting element 20 satisfies a predetermined standard.
  • the height of the luminance it was determined whether or not the luminance measured when the light emitting device 10 emitted light was equal to or higher than a predetermined value.
  • FIG. 5A is a diagram showing luminance unevenness when measured with the light emitting element 20 alone.
  • FIG. 5B is a diagram illustrating the light emitting surface 20a of the light emitting element 20 when the width of the light emitting element 20 is aligned with the horizontal axis of FIG. 5A for easy understanding. As shown in FIG. 5A, it can be seen that the luminance is greatly reduced at the portion where the electrode 20c is provided.
  • FIG. 6A is a diagram showing luminance unevenness in the light emitting element 20 when measured using each of the light wavelength conversion layer 30 according to the example and the light wavelength conversion layer 30 according to Comparative Example 1.
  • FIG. A line L0 indicates luminance unevenness when the light wavelength conversion layer 30 according to the example is used
  • a line L1 indicates luminance unevenness when the light wavelength conversion layer 30 according to the comparative example 1 is used.
  • FIG. 6B is a diagram showing the light emitting surface 20a of the light emitting element 20 when the width of the light emitting element 20 is aligned with the horizontal axis of FIG. 6A for easy understanding.
  • FIG. 7A is a diagram showing luminance unevenness between the light emitting elements 20 when measured using each of the light wavelength conversion layer 30 according to the example and the light wavelength conversion layer 30 according to Comparative Example 2.
  • FIG. A line L0 indicates luminance unevenness when the light wavelength conversion layer 30 according to the example is used
  • a line L1 indicates luminance unevenness when the light wavelength conversion layer 30 according to comparative example 2 is used.
  • FIG. 7B is a top view of the light emitting device 10 when the width of the light emitting device 10 is aligned with the horizontal axis of FIG. 7A for easy understanding.
  • the luminance gradually decreases as it goes from the center of the light emitting surface 20 a of the light emitting element 20 to between the light emitting elements 20.
  • the luminance of the light emitting surface 20a is dispersed in the region between the light emitting surfaces 20a.
  • the range is very narrow, and it is difficult to discriminate luminance unevenness compared to the case where the light wavelength conversion layer 30 according to Comparative Example 2 is used.
  • the light-emitting devices 10 of Comparative Example 1, Comparative Example 2, and Example all satisfied the standards for individual dimming performance and luminance unevenness between the light-emitting elements 20.
  • the luminance unevenness in the light emitting device 10 and the luminance height of the light emitting device 10 also satisfied the standards.
  • Comparative Example 1 having the light wavelength conversion layer 30 with a low diffusivity the luminance unevenness in the light emitting element 20 did not satisfy the standard.
  • Comparative Example 2 having the light wavelength conversion layer 30 with low transmittance the luminance of the light emitting device 10 was less than a predetermined value.
  • the light wavelength conversion layer 30 emits light when the transmittance of the secondary light (for example, yellow light) converted from the light emitted from the light emitting element 20 is 60% or more and the diffusivity is 80% or more. It has been found that the device 10 can emit light appropriately.
  • the transmittance of the secondary light for example, yellow light
  • FIG. 8A is a diagram showing the relationship between the transmittance and diffusivity of the optical wavelength conversion layer 30 according to the comparative example 3 and the example, and the reflectance of the surface of the frame 50. Also in this case, except for the light wavelength conversion layer 30, the above-described light emitting device 10 was used in common in Comparative Example 3 and the example.
  • the light wavelength conversion layer 30 of Comparative Example 3 and Examples has a transmittance of 50% and a diffusivity of 80%.
  • the reflectance of the frame 50 was measured when the light of 600 nm was irradiated. In the light emitting device 10 according to Comparative Example 3, no reflective film was provided on the surface of the frame 50, and in the light emitting device 10 according to the example, a reflective film made of barium oxide or the like was provided on the surface of the frame 50. For this reason, the reflectance of the frame 50 in the comparative example 3 was 35%, and the reflectance of the frame 50 in the example was 50%.
  • FIG. 8B is a diagram showing the results of each test of the light emitting device 10 according to the comparative example 3 and the example.
  • the test items are the same as those shown in FIG.
  • the light emitting device 10 according to the example has all the individual dimming performance, the luminance unevenness between the light emitting elements 20, the luminance unevenness in the light emitting element 20, and the brightness of the light emitting device 10. Met the criteria.
  • Comparative Example 3 satisfied the standards in the individual dimming performance, the luminance unevenness between the light emitting elements 20, and the luminance unevenness in the light emitting element 20, but the high luminance of the light emitting device 10 did not consider the reference. For this reason, it can be seen that providing a reflective film on the frame 50 to increase the reflectance has an effect of improving the luminance of the light emitting device 10.
  • FIG. 9A shows the transmittance, diffusivity, and surface of the frame 50 of the optical wavelength conversion layer 30 according to Comparative Example 4-1, Comparative Example 4-2, Example 4-1, and Example 4-2. It is a figure which shows the relationship with a reflectance. Also in this case, except for the light wavelength conversion layer 30, the above-described light emitting device 10 was used in common in the comparative example and the example.
  • the light wavelength conversion layers 30 of Comparative Example 4-1, Comparative Example 4-2, Example 4-1, and Example 4-2 have a transmittance of 80% and a diffusivity of 99.7%.
  • a light wavelength conversion layer 30 having a thickness of 20 ⁇ m was used.
  • a light wavelength conversion layer 30 having a thickness of 6000 ⁇ m was used.
  • a light wavelength conversion layer 30 having a thickness of 30 ⁇ m was used.
  • the light wavelength conversion layer 30 having a thickness of 5000 ⁇ m was used.
  • FIG. 9B is a diagram showing the results of each test of the light emitting device 10 according to Comparative Example 4-1, Comparative Example 4-2, Example 4-1, and Example 4-2.
  • the test items are the same as those shown in FIG.
  • the light-emitting device 10 according to Example 4-1 and Example 4-2 includes individual dimming performance, luminance unevenness between the light-emitting elements 20, luminance unevenness within the light-emitting element 20, and The standard was satisfied in all the brightness heights of the light emitting device 10.
  • the light wavelength conversion layer 30 according to Comparative Example 4-1 was too thin, cracks occurred, and each test could not be performed.
  • the individual dimming performance, the luminance unevenness between the light emitting elements 20 and the luminance unevenness in the light emitting element 20 met the standard, but the brightness of the light emitting device 10 was high.
  • the standard was not met.
  • the light wavelength conversion layer 30 preferably has a thickness of 30 ⁇ m or more and 5000 ⁇ m or less.
  • the light emitting element 20 is formed by growing a semiconductor layer on a crystal growth substrate such as sapphire, for example.
  • a crystal growth substrate such as sapphire
  • the one that is left without removing the crystal growth substrate is used. For this reason, the light guided through the crystal growth substrate is emitted also from the side surface of the light emitting element. Light is also emitted from the semiconductor layer portion of the side surface 20b. Therefore, the side surface 20b also functions as a light emitting surface.
  • the vertical surface 50d has a height lower than the height from the upper surface 40a of the mounting substrate 40 to the light emitting surface 20a.
  • the vertical surface 50d may be deleted.
  • the mounting substrate 40 is formed in a shape having a triangular cross section with a pair of inclined surfaces 50c and a bottom surface. Thereby, the light emitted from the side surface 20b can also be reflected toward the emission surface 30a, and the light extraction efficiency can be further increased.
  • a plate-shaped light wavelength conversion member is provided in place of the light wavelength conversion layer 30.
  • This light wavelength conversion member is also arranged opposite to the light emitting surface 20a of the light emitting element 20 and parallel to the light emitting surface 20a. Therefore, the same number of light wavelength conversion members as the light emitting elements 20 are used.
  • the light wavelength conversion member is a so-called luminescent ceramic or fluorescent ceramic, and is obtained by sintering a ceramic substrate made of YAG (Yttrium Aluminum Garnet) powder, which is a phosphor excited by blue light. Obtainable. Since the manufacturing method of such a light wavelength conversion ceramic is well-known, detailed description is abbreviate
  • the light wavelength conversion member is not limited to a sintered ceramic, and includes, for example, amorphous, polycrystalline, and single crystal, and is not limited by the crystal structure. Moreover, the transparent thing is employ
  • “transparent” means that the total light transmittance of light in the conversion wavelength region is 40% or more. Thereby, the light which the light emitting element 20 emits can be converted more efficiently.
  • the light wavelength conversion layer member is provided such that the transmittance of secondary light (for example, yellow light) obtained by converting the light emitted from the light emitting element 20 is 60% or more and the diffusivity is 80% or more. Thereby, generation
  • secondary light for example, yellow light
  • Each of the plurality of light wavelength conversion members is placed on the four inclined surfaces 50c. At this time, the light wavelength conversion member is bonded and fixed to the four inclined surfaces 50c.
  • the side surface of the light wavelength conversion member is inclined so that the distance from the center of the light wavelength conversion member increases as it approaches the emission surface.
  • the light wavelength conversion member is formed so that the inclination angle of each of the four side surfaces with respect to the incident surface is the same as the inclination angle of the inclined surface 50c with respect to the light emitting surface 20a and the inclination angle of the inclined surface 50c with respect to the light emitting surface 20a.
  • the four side surfaces of the light wavelength conversion member are the inclined surface 50c of the outer frame 50a and the partition frame 50b, respectively. In contact with the inclined surface 50c. Thereby, the light emitted from the light emitting element 20 can be used more effectively.
  • the present invention can be used for a light emitting device.

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Abstract

In this light-emitting device (10), a partition frame (50b) partitions a plurality of light-emitting elements (20) provided in parallel. In the light-emitting elements (20), an electrode is formed at the light-emitting surface (20a). An optical wavelength conversion layer (30) is provided facing the light-emitting surface (20a) of each of the plurality of light-emitting elements (20). The optical wavelength conversion layer (30) is provided in a manner so that the transmittance of converted secondary light is at least 60% and the diffusivity, which is the fraction of diffused light exiting by at least a predetermined angle with respect to the optical axis of the light-emitting elements (20) as a share of all the light emitted from the optical wavelength conversion layer (30), is at least 80%. In the partition frame (50b), a reflective film is provided in a manner so that the surface reflectivity is at least 70%.

Description

発光装置Light emitting device
　本発明は、発光装置に関し、特に、半導体発光素子と、半導体発光素子の発光面に対向して配置された光波長変換部材と、を備えた発光装置に関する。 The present invention relates to a light emitting device, and more particularly, to a light emitting device including a semiconductor light emitting element and a light wavelength conversion member disposed to face the light emitting surface of the semiconductor light emitting element.
　従来から、蛍光体などを用いてＬＥＤ（Light Emitting Diode）などの発光素子が発する光を波長変換することにより、発光素子が発する光の色とは異なる色の光を出射する発光モジュールを得る技術が知られている。これに対し、光の波長を変換するときの変換効率を増大させるべく、例えば波長変換材料を含むセラミック層を発光層によって放出された光の経路内に配置する技術が提案されている（例えば、特許文献１参照）。一方、前走車にグレアを与えることなく視認性を向上させるべく、例えば複数のＬＥＤを点消灯制御して複数の照射パターンのうち選択された照射パターンを形成させる車両用灯具が提案されている（例えば、特許文献２参照）。また、例えば、小型軽量で所要の配光特性を得るべく、平面配列されたＬＥＤを表面に有する面状集積光源と、発光部を露呈させる開口部を有するマスクと、マスクの開口部内に充填された蛍光体と、を備える車両用灯具が提案されている（例えば、特許文献３参照）。 Conventionally, a technology for obtaining a light emitting module that emits light of a color different from the color of light emitted from the light emitting element by converting the wavelength of light emitted from the light emitting element such as an LED (Light Emitting Diode) using a phosphor or the like. It has been known. On the other hand, in order to increase the conversion efficiency when converting the wavelength of light, for example, a technique has been proposed in which a ceramic layer including a wavelength conversion material is disposed in a path of light emitted by a light emitting layer (for example, Patent Document 1). On the other hand, in order to improve the visibility without giving glare to the preceding vehicle, for example, a vehicular lamp has been proposed in which a plurality of LEDs are controlled to be turned on and off to form an irradiation pattern selected from the plurality of irradiation patterns. (For example, refer to Patent Document 2). Further, for example, in order to obtain a required light distribution characteristic with a small size and light weight, a planar integrated light source having planarly arranged LEDs on the surface, a mask having an opening for exposing the light emitting part, and an opening of the mask are filled. In addition, a vehicular lamp including a phosphor has been proposed (see, for example, Patent Document 3).
特開２００６－５３６７号公報JP 2006-5367 A 特開２００７－１７９９６９号公報JP 2007-179969 A 特開２００８－１０２２８号公報JP 2008-10228 A
　例えば、上述の特許文献２に記載される技術のように、投影レンズの後方焦点面に複数の発光素子を並べて各々を独立して点灯可能とした場合、例えば一つの発光素子を消灯させて非照射領域を設けようとしても、隣接する他の発光素子の光が非照射領域に入り込むおそれがある。このため、例えば複数の発光素子の間に仕切り部材を設ける対策も考えられるが、この対策では、今度はすべての発光素子を点灯させたときに、隣接する発光素子の間に輝度が低い部分が生じる輝度ムラが生じる可能性がある。 For example, as in the technique described in Patent Document 2 described above, when a plurality of light emitting elements are arranged on the rear focal plane of the projection lens so that each can be turned on independently, for example, one light emitting element is turned off and non-lighted. Even if an irradiation region is provided, light from another adjacent light emitting element may enter the non-irradiation region. For this reason, for example, a measure of providing a partition member between a plurality of light emitting elements is conceivable. However, in this measure, when all the light emitting elements are turned on, there is a portion with low luminance between adjacent light emitting elements. The resulting brightness unevenness may occur.
　一方、例えば、いわゆるフェイスアップ型または垂直チップ型の発光素子の場合、発光面に電極が形成される場合がある。一般にＬＥＤは指向性が高く、このため、発光面の電極形状もまた輝度ムラとして表れるおそれがある。 On the other hand, for example, in the case of a so-called face-up type or vertical chip type light emitting element, an electrode may be formed on the light emitting surface. In general, LEDs have high directivity, and therefore, the electrode shape of the light emitting surface may also appear as luminance unevenness.
　そこで、本発明は上述した課題を解決するためになされたものであり、その目的は、複数の発光素子の間に設けられた仕切り枠または発光面に設けられた電極による輝度ムラを低減させることにある。 Accordingly, the present invention has been made to solve the above-described problems, and an object of the present invention is to reduce luminance unevenness due to a partition frame provided between a plurality of light emitting elements or electrodes provided on a light emitting surface. It is in.
　上記課題を解決するために、本発明のある態様の発光装置は、並設された複数の半導体発光素子を仕切る仕切り枠と、複数の半導体発光素子の各々の発光面に対向して設けられた光波長変換層と、を備える。光波長変換層は、変換した２次光（例えば黄色光）の透過率が６０％以上、且つ光波長変換層から出射する全体光のうち半導体発光素子の光軸に対し所定角度以上で出射する拡散光の割合である拡散率が８０％以上である。 In order to solve the above problems, a light-emitting device according to an aspect of the present invention is provided to face a light-emitting surface of each of a plurality of semiconductor light-emitting elements and a partition frame that partitions the plurality of semiconductor light-emitting elements arranged in parallel. An optical wavelength conversion layer. The light wavelength conversion layer has a transmittance of the converted secondary light (for example, yellow light) of 60% or more, and is emitted at a predetermined angle or more with respect to the optical axis of the semiconductor light emitting element among the entire light emitted from the light wavelength conversion layer. The diffusion rate, which is the ratio of diffused light, is 80% or more.
　発明者による研究開発の結果、上記透過率を６０％以上、上記拡散率を８０％以上とすることで、仕切り枠による輝度低下を適切に抑制できることが判明した。したがってこの態様によれば、複数の半導体発光素子を並設した発光装置における輝度ムラを抑制することができる。 As a result of the inventor's research and development, it was found that the luminance reduction due to the partition frame can be appropriately suppressed by setting the transmittance to 60% or more and the diffusivity to 80% or more. Therefore, according to this aspect, it is possible to suppress luminance unevenness in a light emitting device in which a plurality of semiconductor light emitting elements are arranged in parallel.
　仕切り枠は、端部に近づくほど厚みが減少するよう形成され、光波長変換層は、仕切り枠の端部近傍において仕切り枠の表面に接して配置されてもよい。この態様によれば、上方から見て仕切り枠が設けられた範囲にさしかかるように光波長変換層を延在させることができ、仕切り枠部分の輝度低下を抑制できる。また、仕切り枠の端部において光波長変換層の出射面に向けて光を反射することができ、光の取り出し効率を向上させることができる。 The partition frame may be formed so that the thickness decreases as it approaches the end, and the light wavelength conversion layer may be disposed in contact with the surface of the partition frame in the vicinity of the end of the partition frame. According to this aspect, the light wavelength conversion layer can be extended so as to reach the range in which the partition frame is provided when viewed from above, and the luminance reduction of the partition frame portion can be suppressed. Moreover, light can be reflected toward the emission surface of the light wavelength conversion layer at the end of the partition frame, and the light extraction efficiency can be improved.
　仕切り枠は、少なくとも一部の表面の反射率が７０％以上であってもよい。発明者による研究開発の結果、仕切り枠の反射率を７０％以上にすることにより、反射率が７０％未満の場合に比べ、発光装置の輝度の高さが向上することが判明した。このためこの態様によれば、仕切り枠を設けることによる輝度低下を抑制することができる。 The partition frame may have a reflectance of 70% or more on at least a part of its surface. As a result of the inventor's research and development, it has been found that when the reflectance of the partition frame is set to 70% or more, the luminance of the light emitting device is improved as compared with the case where the reflectance is less than 70%. For this reason, according to this aspect, the brightness | luminance fall by providing a partition frame can be suppressed.
　光波長変換層は、３０μｍ以上５０００μｍ以下の厚みを有してもよい。この態様によれば、光波長変換層の割れを回避しつつ輝度ムラを抑制できる。 The light wavelength conversion layer may have a thickness of 30 μm or more and 5000 μm or less. According to this aspect, luminance unevenness can be suppressed while avoiding cracking of the light wavelength conversion layer.
　本発明の別の態様もまた、発光装置である。この装置は、発光面に電極が形成された半導体発光素子と、発光面に対向して配置された光波長変換層と、を備える。光波長変換層は、変換した２次光（例えば黄色光）の透過率が６０％以上、且つ光波長変換層から出射する全体光のうち半導体発光素子の光軸に対し所定角度以上で出射する拡散光の割合である拡散率が８０％以上である。 Another embodiment of the present invention is also a light emitting device. This device includes a semiconductor light emitting element having an electrode formed on a light emitting surface, and an optical wavelength conversion layer disposed to face the light emitting surface. The light wavelength conversion layer has a transmittance of the converted secondary light (for example, yellow light) of 60% or more, and is emitted at a predetermined angle or more with respect to the optical axis of the semiconductor light emitting element among the entire light emitted from the light wavelength conversion layer. The diffusion rate, which is the ratio of diffused light, is 80% or more.
　発明者の研究開発の結果、上記透過率を６０％以上、上記拡散率を８０％以上とすることで、発光面の電極よる輝度低下を適切に抑制できることが判明した。したがってこの態様によれば、半導体発光素子の発光面に設けられた電極による輝度ムラを抑制することができる。この態様においても、光波長変換層は、３０μｍ以上５０００μｍ以下の厚みを有してもよい。 As a result of the inventor's research and development, it has been found that, by setting the transmittance to 60% or more and the diffusivity to 80% or more, it is possible to appropriately suppress the luminance reduction due to the electrode on the light emitting surface. Therefore, according to this aspect, luminance unevenness due to the electrodes provided on the light emitting surface of the semiconductor light emitting element can be suppressed. Also in this aspect, the light wavelength conversion layer may have a thickness of 30 μm or more and 5000 μm or less.
　本発明によれば、複数の発光素子の間に設けられた仕切り枠または発光面に設けられた電極による輝度ムラを低減させることができる。 According to the present invention, it is possible to reduce luminance unevenness due to a partition frame provided between a plurality of light emitting elements or electrodes provided on a light emitting surface.
本実施形態に係る発光装置の上面図である。It is a top view of the light-emitting device concerning this embodiment. 図１のＰ－Ｐ断面図である。FIG. 2 is a sectional view taken along the line PP in FIG. 1. （ａ）および（ｂ）は、拡散率の測定システムを示す図である。(A) And (b) is a figure which shows the measurement system of a spreading | diffusion rate. （ａ）は、比較例１、比較例２、および実施例に係る光波長変換層の透過率と拡散率との関係を示す図である。（ｂ）は、比較例１、比較例２、および実施例に係る発光装置の各試験における結果を示す図である。(A) is a figure which shows the relationship between the transmittance | permeability and the diffusivity of the optical wavelength conversion layer which concerns on the comparative example 1, the comparative example 2, and an Example. (B) is a figure which shows the result in each test of the light-emitting device which concerns on the comparative example 1, the comparative example 2, and an Example. （ａ）は、発光素子のみで測定したときの輝度ムラを示す図である。（ｂ）は、理解を容易にすべく、（ａ）の横軸に発光素子の幅を合わせたときの発光素子の発光面を示す図である。(A) is a figure which shows a brightness nonuniformity when it measures only with a light emitting element. (B) is a figure which shows the light emission surface of a light emitting element when the width | variety of a light emitting element is united with the horizontal axis of (a) for easy understanding. （ａ）は、実施例に係る光波長変換層と比較例１に係る光波長変換層の各々を用いて測定したときの発光素子内の輝度ムラを示す図である。（ｂ）は、理解を容易にすべく、（ａ）の横軸に発光素子の幅を合わせたときの発光素子の発光面を示す図である。(A) is a figure which shows the brightness nonuniformity in a light emitting element when it measures using each of the light wavelength conversion layer which concerns on an Example, and the light wavelength conversion layer which concerns on the comparative example 1. FIG. (B) is a figure which shows the light emission surface of a light emitting element when the width | variety of a light emitting element is united with the horizontal axis of (a) for easy understanding. （ａ）は、実施例に係る光波長変換層と比較例２に係る光波長変換層の各々を用いて測定したときの発光素子間の輝度ムラを示す図である。（ｂ）は、理解を容易にすべく、（ａ）の横軸に発光装置の幅を合わせたときの発光装置の上面図である。(A) is a figure which shows the brightness nonuniformity between light emitting elements when it measures using each of the light wavelength conversion layer which concerns on an Example, and the light wavelength conversion layer which concerns on the comparative example 2. FIG. (B) is a top view of the light emitting device when the width of the light emitting device is adjusted to the horizontal axis of (a) for easy understanding. （ａ）は、比較例３および実施例に係る光波長変換層の透過率、拡散率、および枠表面の反射率との関係を示す図である。（ｂ）は、比較例３および実施例に係る発光装置の各試験における結果を示す図である。(A) is a figure which shows the relationship between the transmittance | permeability of the light wavelength conversion layer which concerns on the comparative example 3 and an Example, a diffusivity, and the reflectance of the frame surface. (B) is a figure which shows the result in each test of the light-emitting device which concerns on the comparative example 3 and an Example. （ａ）は、比較例４－１、比較例４－２、実施例４－１、および実施例４－１に係る光波長変換層の透過率、拡散率、および枠表面の反射率との関係を示す図である。（ｂ）は、比較例４－１、比較例４－２、実施例４－１、および実施例４－２に係る発光装置の各試験における結果を示す図である。(A) shows the transmittance, the diffusivity, and the reflectance of the frame surface of the light wavelength conversion layer according to Comparative Example 4-1, Comparative Example 4-2, Example 4-1, and Example 4-1. It is a figure which shows a relationship. (B) is a figure which shows the result in each test of the light-emitting device which concerns on the comparative example 4-1, comparative example 4-2, Example 4-1, and Example 4-2.
　以下、図面を参照して本発明の実施の形態（以下、実施形態という）について詳細に説明する。 Hereinafter, embodiments of the present invention (hereinafter referred to as embodiments) will be described in detail with reference to the drawings.
　図１は、本実施形態に係る発光装置１０の上面図である。図２は、図１のＰ－Ｐ断面図である。以下、図１および図２の双方に関連して発光装置１０の構成について説明する。 FIG. 1 is a top view of the light emitting device 10 according to the present embodiment. 2 is a cross-sectional view taken along the line PP in FIG. Hereinafter, the configuration of the light emitting device 10 will be described with reference to both FIG. 1 and FIG.
　発光装置１０は、発光素子２０、光波長変換層３０、実装基板４０、および枠５０を有する。発光素子２０は、四角形状の発光面２０ａと、発光面２０ａにそれぞれ直角に接する４つの側面２０ｂとを有する。なお、発光面２０ａと側面２０ｂとは直角以外の角度で互いに接してもよい。 The light emitting device 10 includes a light emitting element 20, a light wavelength conversion layer 30, a mounting substrate 40, and a frame 50. The light emitting element 20 has a rectangular light emitting surface 20a and four side surfaces 20b that are in contact with the light emitting surface 20a at right angles. The light emitting surface 20a and the side surface 20b may contact each other at an angle other than a right angle.
　実装基板４０は、ＡｌＮなど熱伝導性が高い材料によって平板状に形成される。この実装基板４０の上面４０ａに、各々の発光面２０ａが上面４０ａと平行となるよう複数の発光素子２０が実装される。実装基板４０は、これら複数の発光素子２０が実装可能な面積を有する。本実施形態では、複数の発光素子２０は、互いに離間するよう一列に並設される。しかし、複数の実装基板４０が複数列を構成するよう並設されるなど、平面上に複数の実装基板４０が並設されてもよい。 The mounting substrate 40 is formed in a flat plate shape using a material having high thermal conductivity such as AlN. A plurality of light emitting elements 20 are mounted on the upper surface 40a of the mounting substrate 40 such that each light emitting surface 20a is parallel to the upper surface 40a. The mounting substrate 40 has an area where the plurality of light emitting elements 20 can be mounted. In the present embodiment, the plurality of light emitting elements 20 are arranged in a row so as to be separated from each other. However, a plurality of mounting boards 40 may be arranged side by side on a plane, such as a plurality of mounting boards 40 arranged side by side to form a plurality of rows.
　発光素子２０は、半導体発光素子であるＬＥＤ素子によって構成される。本実施形態では、発光素子２０として、青色の波長の光を主として発する青色ＬＥＤが採用されている。具体的には、発光素子２０は、ＩｎＧａＮ系半導体層を結晶成長させることにより形成されるＩｎＧａＮ系ＬＥＤ素子によって構成されている。なお、発光素子２０を形成するための材料はこれに限られず、例えばＩｎＮ、ＡｌＧａＮ、ＡＩＮのいずれかであってもよい。 The light emitting element 20 is constituted by an LED element which is a semiconductor light emitting element. In the present embodiment, a blue LED that mainly emits light having a blue wavelength is employed as the light emitting element 20. Specifically, the light emitting element 20 is configured by an InGaN LED element formed by crystal growth of an InGaN semiconductor layer. The material for forming the light emitting element 20 is not limited to this, and may be any one of InN, AlGaN, and AIN, for example.
　発光素子２０は、いわゆるフリップチップ型のものが採用される。このため、発光素子２０は、発光面２０ａに電極２０ｃが形成されている。なお、いわゆるフェイスアップ型や垂直チップ型の発光素子２０が採用されてもよい。実装基板４０の上面４０ａには電極（図示せず）が設けられており、複数の発光素子２０の裏面がＡｕバンプを介してこの電極に接続される。この電極は、複数の発光素子２０の各々に独立して電流を供給できるよう複数の発光素子２０の各々と電源とをスイッチング回路を介して互いに接続する。これにより、複数の発光素子２０の各々を独立して点灯制御や調光制御をすることが可能となる。なお、上面４０ａに設けられた電極は、複数の発光素子２０に同時に電力を供給することができるよう、複数の発光素子２０を電気的に直列または並列に接続するよう設けられてもよい。 The light emitting element 20 is a so-called flip chip type. For this reason, the light emitting element 20 has an electrode 20c formed on the light emitting surface 20a. Note that a so-called face-up type or vertical chip type light emitting element 20 may be employed. An electrode (not shown) is provided on the upper surface 40a of the mounting substrate 40, and the back surfaces of the plurality of light emitting elements 20 are connected to the electrodes through Au bumps. This electrode connects each of the plurality of light emitting elements 20 and the power supply to each other via a switching circuit so that a current can be independently supplied to each of the plurality of light emitting elements 20. Thereby, it becomes possible to perform lighting control and light control of each of the plurality of light emitting elements 20 independently. The electrodes provided on the upper surface 40a may be provided so as to electrically connect the plurality of light emitting elements 20 in series or in parallel so that power can be supplied to the plurality of light emitting elements 20 simultaneously.
　本実施形態では、４つの発光素子２０が互いの縁部が平行になるよう隣接して一列に配置されている。なお、発光素子２０の数が４つに限定されないことは勿論である。また、発光素子２０は、複数列をなすよう配置されてもよい。 In the present embodiment, the four light emitting elements 20 are arranged in a row adjacent to each other so that their edges are parallel to each other. Of course, the number of the light emitting elements 20 is not limited to four. Further, the light emitting elements 20 may be arranged in a plurality of rows.
　本実施形態に係る発光装置１０は、車両用前照灯の光源として利用される。なお、発光装置１０の用途がこれに限定されないことは勿論である。発光装置１０は、投影レンズの後方焦点面に４つの発光素子２０の発光面が位置するよう配置される。 The light emitting device 10 according to the present embodiment is used as a light source for a vehicle headlamp. Of course, the use of the light emitting device 10 is not limited to this. The light emitting device 10 is arranged such that the light emitting surfaces of the four light emitting elements 20 are positioned on the rear focal plane of the projection lens.
　発光素子２０は、例えば１ｍｍ角のチップとして形成され、発する青色光の中心波長は４７０ｎｍとなるよう設けられている。なお、発光素子２０の構成や発する光の波長が上述したものに限られないことは勿論であり、発光素子２０は青以外の波長の光を主として発するものが採用されてもよい。 The light emitting element 20 is formed as a 1 mm square chip, for example, and is provided so that the center wavelength of the emitted blue light is 470 nm. Of course, the configuration of the light-emitting element 20 and the wavelength of emitted light are not limited to those described above, and the light-emitting element 20 may mainly emit light having a wavelength other than blue.
　発光装置１０は、複数の発光素子２０のいずれかを消灯させることで発光装置１０による配光パターンに非照射領域を設けるための光源として利用される。例えば、前方車などグレアの付与を回避すべき対象物の存在がカメラなどを通じて検出された場合、その対象物を配光パターンに含む発光素子２０を消灯させる。これにより、その対象物周辺を非照射領域として、グレアの付与を抑制する。このため、発光素子２０を消灯したとき、その発光素子２０が形成していた配光パターンの領域はすべて非照射領域となることが望ましい。しかし、隣接する一方の発光素子２０を発光させたときに、消灯されている他方の発光素子２０の発光領域に進む光を抑制することができないと、消灯させた発光素子２０の配光パターン領域にも光が照射され、対象物にグレアを与える可能性がある。以下、隣接する発光素子２０の発光領域へどれほど影響を与えないかを示す発光装置１０の性能を、「個別調光性能」という。 The light emitting device 10 is used as a light source for providing a non-irradiation region in a light distribution pattern by the light emitting device 10 by turning off any of the plurality of light emitting elements 20. For example, when the presence of an object such as a preceding vehicle that should avoid glare is detected through a camera or the like, the light emitting element 20 including the object in the light distribution pattern is turned off. Thereby, the periphery of the object is set as a non-irradiated region, and the application of glare is suppressed. For this reason, when the light emitting element 20 is turned off, it is desirable that the region of the light distribution pattern formed by the light emitting element 20 is a non-irradiated region. However, if one of the adjacent light emitting elements 20 is caused to emit light and the light traveling to the light emitting area of the other light emitting element 20 that has been extinguished cannot be suppressed, the light distribution pattern area of the light emitting element 20 that has been extinguished May also be irradiated with light, which may give glare to the object. Hereinafter, the performance of the light emitting device 10 indicating how much the light emitting area of the adjacent light emitting element 20 is not affected is referred to as “individual dimming performance”.
　この個別調光性能を高めるため、発光装置１０には枠５０が設けられている。枠５０は、外枠５０ａおよび仕切り枠５０ｂを有する。外枠５０ａは、矩形の枠状に形成され、断面は四角形状に形成される。外枠５０ａは、複数の発光素子２０のすべてを囲うように実装基板４０の上面４０ａに載置され、下面が上面４０ａに接着され実装基板４０に固定される。外枠５０ａは、枠の内面に傾斜面５０ｃを有する。傾斜面５０ｃは、一列に並ぶ複数の発光素子２０のいずれかの側面２０ｂに隣接する。 In order to improve the individual light control performance, the light emitting device 10 is provided with a frame 50. The frame 50 includes an outer frame 50a and a partition frame 50b. The outer frame 50a is formed in a rectangular frame shape, and the cross section is formed in a square shape. The outer frame 50 a is placed on the upper surface 40 a of the mounting substrate 40 so as to surround all of the plurality of light emitting elements 20, and the lower surface is bonded to the upper surface 40 a and fixed to the mounting substrate 40. The outer frame 50a has an inclined surface 50c on the inner surface of the frame. The inclined surface 50c is adjacent to any side surface 20b of the plurality of light emitting elements 20 arranged in a line.
　仕切り枠５０ｂは、一対の傾斜面５０ｃ、および一対の垂直面５０ｄを含む五角柱状に形成される。仕切り枠５０ｂは、下面が上面４０ａに接着され実装基板４０に固定される。仕切り枠５０ｂは、並設された複数の発光素子２０を仕切るよう配置される。仕切り枠５０ｂを設けることにより、複数の発光素子２０の発光領域を仕切ることができる。このため、隣接する一方の発光素子２０を発光させたときに、消灯されている他方の発光素子２０の発光領域に進む光を抑制することができる。 The partition frame 50b is formed in a pentagonal prism shape including a pair of inclined surfaces 50c and a pair of vertical surfaces 50d. The partition frame 50 b is fixed to the mounting substrate 40 with the lower surface bonded to the upper surface 40 a. The partition frame 50b is disposed so as to partition the plurality of light emitting elements 20 arranged in parallel. By providing the partition frame 50b, the light emitting regions of the plurality of light emitting elements 20 can be partitioned. For this reason, when the adjacent one light emitting element 20 is caused to emit light, the light traveling to the light emitting region of the other light emitting element 20 that is turned off can be suppressed.
　発明者は、仕切り枠５０ｂを設けた場合と仕切り枠５０ｂを削除した場合とで個別調光性能の実験を行った。その結果、仕切り枠５０ｂがない場合は隣接する一方の発光素子２０を発光させたときに、消灯されている他方の発光素子２０の発光領域に多くの光が進み、個別調光性能が低いことが判明した。これに対し、仕切り枠５０ｂを設けることで、個別調光性能が格段に高まることが確認された。 The inventor conducted experiments on individual dimming performance when the partition frame 50b was provided and when the partition frame 50b was deleted. As a result, when there is no partition frame 50b, when one of the adjacent light emitting elements 20 is caused to emit light, a large amount of light travels to the light emitting region of the other light emitting element 20 that is turned off, and the individual dimming performance is low. There was found. On the other hand, it was confirmed that the individual dimming performance is remarkably enhanced by providing the partition frame 50b.
　傾斜面５０ｃは、発光素子２０の発光方向、すなわち発光素子２０の主光軸方向に進むほど拡開するよう傾斜する。言い換えると、傾斜面５０ｃは、外枠５０ａの上面に近づくにしたがって、隣接する側面２０ｂを含む平面から離間するよう傾斜する。 The inclined surface 50c is inclined so as to expand as it proceeds in the light emitting direction of the light emitting element 20, that is, in the main optical axis direction of the light emitting element 20. In other words, the inclined surface 50c is inclined so as to be separated from the plane including the adjacent side surface 20b as it approaches the upper surface of the outer frame 50a.
　一対の垂直面５０ｄの各々は、隣接する傾斜面５０ｃに接すると共に、傾斜面５０ｃよりも光波長変換層３０から離間した位置において発光面２０ａおよび上面４０ａと垂直に延在する。このような垂直面５０ｄを設けることにより、互いに隣接する一対の発光素子２０の間においても、仕切り枠５０ｂと発光素子２０の側面２０ｂに近づけることができ、両者の間における低輝度部分の発生を抑制することができる。本実施形態では、垂直面５０ｄは発光面２０ａよりも僅かに低い高さ、すなわち実装基板４０の上面４０ａに近い高さを有する。なお、垂直面５０ｄは、実装基板４０の上面４０ａから発光面２０ａまでの高さと同一の高さを有していてもよい。また、垂直面５０ｄは、実装基板４０の上面４０ａから発光面２０ａまでの高さより高い高さを有していてもよい。 Each of the pair of vertical surfaces 50d is in contact with the adjacent inclined surface 50c and extends perpendicularly to the light emitting surface 20a and the upper surface 40a at a position farther from the light wavelength conversion layer 30 than the inclined surface 50c. By providing such a vertical surface 50d, the partition frame 50b and the side surface 20b of the light emitting element 20 can be brought close to each other even between a pair of light emitting elements 20 adjacent to each other. Can be suppressed. In the present embodiment, the vertical surface 50d has a slightly lower height than the light emitting surface 20a, that is, a height close to the upper surface 40a of the mounting substrate 40. The vertical surface 50d may have the same height as the height from the upper surface 40a of the mounting substrate 40 to the light emitting surface 20a. Further, the vertical surface 50d may have a height higher than the height from the upper surface 40a of the mounting substrate 40 to the light emitting surface 20a.
　仕切り枠５０ｂは、複数の発光素子２０のうち互いに隣り合う一対の発光素子２０を区分けるよう、一対の発光素子２０の間から、その一対の発光素子２０にそれぞれ対向する一対の光波長変換層３０の間にわたって延在する。発光素子２０は一列に配設されるため、仕切り枠５０ｂは、発光素子２０の個数より１つ少ない個数設けられる。本実施形態では発光素子２０は４つ設けられているため、仕切り枠５０ｂは３つ設けられている。なお、複数の発光素子２０が複数列を構成するよう平面上に並設された場合も、仕切り枠５０ｂは、互いに隣り合う一対の発光素子２０を区分けるよう両者の間に配置される。 The partition frame 50b includes a pair of light wavelength conversion layers that are opposed to the pair of light emitting elements 20 from between the pair of light emitting elements 20 so as to partition a pair of adjacent light emitting elements 20 among the plurality of light emitting elements 20. It extends between 30. Since the light emitting elements 20 are arranged in a line, the number of the partition frames 50 b is one less than the number of the light emitting elements 20. In this embodiment, since four light emitting elements 20 are provided, three partition frames 50b are provided. Even when the plurality of light emitting elements 20 are arranged side by side so as to form a plurality of rows, the partition frame 50b is disposed between the pair of light emitting elements 20 adjacent to each other.
　外枠５０ａと仕切り枠５０ｂとは、シリコンによって一体的に形成される。外枠５０ａの上面と、仕切り枠５０ｂの頂部とは同じ高さとなる。本実施形態では、傾斜面５０ｃは、外枠５０ａの上面に対して５４．７°の角度で傾斜している。外枠５０ａおよび仕切り枠５０ｂをシリコンによって形成することにより、正確な傾斜角度で形成することができる。また、外枠５０ａおよび仕切り枠５０ｂをシリコンによって形成することにより、表面を容易に滑らかにすることができ、高い反射効率を実現することができる。なお、外枠５０ａおよび仕切り枠５０ｂがシリコン以外の材料によって形成されてもよいことは勿論である。また、外枠５０ａの上面に対する傾斜面５０ｃの傾斜角度は、２０°以上７０°以下であってもよい。外枠５０ａおよび仕切り枠５０ｂの表面には、例えばアルミニウムまたは銀を蒸着させることによって反射率を高めた反射膜が設けられる。 The outer frame 50a and the partition frame 50b are integrally formed of silicon. The upper surface of the outer frame 50a and the top of the partition frame 50b are at the same height. In the present embodiment, the inclined surface 50c is inclined at an angle of 54.7 ° with respect to the upper surface of the outer frame 50a. By forming the outer frame 50a and the partition frame 50b with silicon, the outer frame 50a and the partition frame 50b can be formed with an accurate inclination angle. Further, by forming the outer frame 50a and the partition frame 50b with silicon, the surface can be easily smoothed, and high reflection efficiency can be realized. Of course, the outer frame 50a and the partition frame 50b may be formed of a material other than silicon. Further, the inclination angle of the inclined surface 50c with respect to the upper surface of the outer frame 50a may be not less than 20 ° and not more than 70 °. On the surfaces of the outer frame 50a and the partition frame 50b, for example, a reflective film whose reflectance is increased by depositing aluminum or silver is provided.
　なお、発明者は、傾斜面５０ｃを設けた場合と、傾斜面５０ｃがなく仕切り枠５０ｂが同一幅で上端に達する場合とで個別調光性能および発光素子２０間の輝度ムラの実験を行った。その結果、どちらも個別調光性能は基準を満たした。発光素子２０間の輝度ムラは、傾斜面５０ｃを設けた場合は基準を満たしたが、傾斜面５０ｃがない場合は基準を満たさなかった。このため、傾斜面５０ｃを設けることで、発光素子２０間の輝度ムラが抑制できることが確認された。 The inventor conducted experiments on individual light control performance and luminance unevenness between the light emitting elements 20 when the inclined surface 50c is provided and when the inclined frame 50c is not provided and the partition frame 50b reaches the upper end with the same width. . As a result, both dimming performances met the standard. The luminance unevenness between the light emitting elements 20 satisfied the standard when the inclined surface 50c was provided, but did not satisfy the standard when the inclined surface 50c was not provided. For this reason, it was confirmed that uneven luminance between the light emitting elements 20 can be suppressed by providing the inclined surface 50c.
　光波長変換層３０は、複数の発光素子２０の各々に対応して複数設けられている。光波長変換層３０は、対応する発光素子２０の発光面２０ａに対向して設けられている。光波長変換層３０は、４つの傾斜面５０ｃおよび４つの垂直面５０ｄによって画定される領域に発光素子２０が実装された後、この領域に充填され形成される。このため、仕切り枠５０ｂは、端部に近づくほど厚みが減少するよう形成される。光波長変換層３０は、仕切り枠５０ｂの端部近傍において仕切り枠５０ｂの表面に接して配置される。本実施例では、光波長変換層３０は、枠５０の上端まで形成される。このため、隣接する光波長変換層３０同士の距離を抑制することができる。 A plurality of light wavelength conversion layers 30 are provided corresponding to each of the plurality of light emitting elements 20. The light wavelength conversion layer 30 is provided to face the light emitting surface 20 a of the corresponding light emitting element 20. The light wavelength conversion layer 30 is formed by filling the region after the light emitting element 20 is mounted in a region defined by the four inclined surfaces 50c and the four vertical surfaces 50d. For this reason, the partition frame 50b is formed so that the thickness decreases as it approaches the end. The light wavelength conversion layer 30 is disposed in contact with the surface of the partition frame 50b in the vicinity of the end of the partition frame 50b. In this embodiment, the light wavelength conversion layer 30 is formed up to the upper end of the frame 50. For this reason, the distance between the adjacent optical wavelength conversion layers 30 can be suppressed.
　こうして光波長変換層３０は、対向する発光素子２０が発する光をそれぞれが波長変換して出射する。光波長変換層３０はいわゆる蛍光体層であり、透明な樹脂のバインダに蛍光体を混合させて形成されている。 In this way, the light wavelength conversion layer 30 converts the wavelength of the light emitted from the opposing light emitting elements 20 and emits the light. The light wavelength conversion layer 30 is a so-called phosphor layer, and is formed by mixing a phosphor with a transparent resin binder.
　光波長変換層３０は、発光素子２０が発する青色光の波長を変換して黄色光を出射する。このため、発光装置１０からは、光波長変換層３０をそのまま透過した青色光と、光波長変換層３０によって波長変換され出射された黄色光との合成光である白色光が出射する。 The light wavelength conversion layer 30 converts the wavelength of the blue light emitted from the light emitting element 20 and emits yellow light. For this reason, the light emitting device 10 emits white light that is a combined light of the blue light that has passed through the light wavelength conversion layer 30 and the yellow light that has been wavelength-converted by the light wavelength conversion layer 30 and emitted.
　枠５０に傾斜面５０ｃを設けることにより、発光素子２０の側面２０ｂから発せられた光や発光面２０ａから水平に近い角度で発せられた光を光波長変換層３０の出射面３０ａに向けて反射することができる。このため、側面２０ｂから発せられた光も有効利用することが可能となり、傾斜面５０ｃを設けない場合に比べ発光装置１０が発する光の輝度や光度を高めることができる。また、複数の発光素子２０が実装される場合においても、隣り合う一対の光波長変換層３０の間における低輝度部分の発生を抑制することができる。 By providing the inclined surface 50 c on the frame 50, the light emitted from the side surface 20 b of the light emitting element 20 or the light emitted from the light emitting surface 20 a at an angle close to horizontal is reflected toward the emission surface 30 a of the light wavelength conversion layer 30. can do. For this reason, the light emitted from the side surface 20b can also be used effectively, and the brightness and luminous intensity of the light emitted from the light emitting device 10 can be increased as compared with the case where the inclined surface 50c is not provided. Moreover, even when a plurality of light emitting elements 20 are mounted, it is possible to suppress the occurrence of a low luminance portion between a pair of adjacent light wavelength conversion layers 30.
　発明者は、枠５０に傾斜面５０ｃを設けた場合と設けない場合とで個別調光性能の実験を行った。その結果、傾斜面５０ｃがない場合は、隣接する発光素子２０の間の領域における輝度が大きく減少することが判明した。これに対し、傾斜面５０ｃを設けた場合、設けない場合に比べ隣接する発光素子２０の間の領域における輝度の低下が抑制されることが確認された。 The inventor conducted an experiment on individual dimming performance with and without the inclined surface 50c on the frame 50. As a result, it has been found that in the absence of the inclined surface 50c, the luminance in the region between the adjacent light emitting elements 20 is greatly reduced. On the other hand, when the inclined surface 50c was provided, it was confirmed that the brightness | luminance fall in the area | region between the adjacent light emitting elements 20 was suppressed compared with the case where it does not provide.
　しかしながら、枠５０に傾斜面５０ｃを設けた場合においても、発光装置１０全体で輝度ムラが生じることが判明した。この輝度ムラを低減させるため、発明者は、光波長変換層３０を出射する光の「拡散率」に着目した。 However, it was found that even when the inclined surface 50 c is provided on the frame 50, luminance unevenness occurs in the entire light emitting device 10. In order to reduce the luminance unevenness, the inventor has focused on the “diffusivity” of the light emitted from the light wavelength conversion layer 30.
　光波長変換層３０に用いられるバインダや蛍光体などと屈折率の異なる成分が、光波長変換層３０の内部、外部、表面のどこかに存在していれば、拡散率を調整することができる。例えば、光波長変換層３０を構成するマトリックス成分と屈折率の異なる物質を添加して拡散率を変化させることができる。また、光波長変換層３０の表面を加工してその形状に変化を与えてもよく、また、光波長変換層３０の表面へ光拡散層を成膜して拡散率を変化させてもよい。 If a component having a refractive index different from that of the binder or phosphor used in the light wavelength conversion layer 30 is present somewhere inside, outside, or on the surface of the light wavelength conversion layer 30, the diffusivity can be adjusted. . For example, the diffusivity can be changed by adding a substance having a refractive index different from that of the matrix component constituting the light wavelength conversion layer 30. Further, the surface of the light wavelength conversion layer 30 may be processed to change its shape, or the light diffusion layer may be formed on the surface of the light wavelength conversion layer 30 to change the diffusivity.
　また、光波長変換層３０を形成する主成分と異なる屈折率を持つ粒子成分を添加して拡散率を変化させてもよい。本実施形態では、透明な樹脂のバインダに蛍光体粒子を添加しているが、透明樹脂の屈折率と蛍光体粒子の屈折率が異なる場合は、透明樹脂に蛍光体粒子を添加することで屈折率も変化している。なお、透明樹脂に蛍光体粒子以外の粒子を添加してもよい。このような粒子の例として、シリカ、アルミナのほか、空気や窒素などの気体成分による泡やボイドなども該当する。 Further, the diffusivity may be changed by adding a particle component having a refractive index different from that of the main component forming the light wavelength conversion layer 30. In this embodiment, the phosphor particles are added to the transparent resin binder. However, when the refractive index of the transparent resin and the refractive index of the phosphor particles are different, the phosphor is refracted by adding the phosphor particles to the transparent resin. The rate has also changed. Note that particles other than the phosphor particles may be added to the transparent resin. Examples of such particles include bubbles and voids due to gas components such as air and nitrogen in addition to silica and alumina.
　主成分と添加成分が同じ物質であっても、屈折率が異なる相であれば、その割合で調整できる。例えば、ポリプロピレンなどの半透明樹脂中の非晶質相の割合、無機物質の酸化チタンではルチル相とアナターゼ相、アルミナ－イットリア共晶系ではガーネット相とペロプスカイト相の割合で拡散率を調整できる。 Even if the main component and the additive component are the same substance, the phase can be adjusted by the ratio as long as the refractive index is different. For example, the diffusivity can be adjusted by the ratio of the amorphous phase in the translucent resin such as polypropylene, the ratio of the rutile phase and the anatase phase in the case of inorganic titanium oxide, and the ratio of the garnet phase and the perovskite phase in the alumina-yttria eutectic system. .
　光波長変換層３０表面の形状加工には、マイクロレンズなどの制御された加工でも、ブラスト法などを用いたランダムな方法でもよい。加工方法は、型を用いた成形の他、研磨、研削などの機械加工や化学エッチングなどの化学的加工であってもよい。 The shape processing on the surface of the light wavelength conversion layer 30 may be controlled processing such as a microlens or a random method using a blast method or the like. The processing method may be mechanical processing such as polishing and grinding, or chemical processing such as chemical etching, in addition to molding using a mold.
　蛍光体層表面への光拡散層の成膜方法には、例えば、シリカ粒子を含んだアクリル透明樹脂を蛍光体表面層に塗布する方法がある。これを厚くすることで、自立した拡散板を設置してもよい。 As a method for forming a light diffusion layer on the surface of the phosphor layer, for example, there is a method in which an acrylic transparent resin containing silica particles is applied to the phosphor surface layer. By increasing the thickness, a self-supporting diffusion plate may be installed.
　図３（ａ）および図３（ｂ）は、拡散率の測定システム１００を示す図である。測定システム１００は、発光装置１０、積分球受光器１０２、光度計１０４、白色板１０６を有する。積分球受光器１０２には、島津製作所製ＳｏｌｉｄＳｐｅｃ－３７００積分球受光器を用いた。積分球受光器１０２は、入射口１０２ａ、出射口１０２ｂ、測定口１０２ｃを有し、これ以外の内面には反射膜が設けられている。この反射膜は、反射率が高いだけでなく、高い拡散性も有している。このため、積分球受光器１０２の内部に出射された光は、積分球受光器１０２の内面で反射を繰り返すことで、内面全体で均一な光度分布を示す。積分球受光器１０２の構造は公知であるため、これ以上の説明は省略する。 3 (a) and 3 (b) are diagrams showing the diffusivity measurement system 100. FIG. The measurement system 100 includes a light emitting device 10, an integrating sphere light receiver 102, a photometer 104, and a white plate 106. As the integrating sphere light receiver 102, a SolidSpec-3700 integrating sphere light receiver manufactured by Shimadzu Corporation was used. The integrating sphere light receiver 102 has an entrance port 102a, an exit port 102b, and a measurement port 102c, and a reflective film is provided on the other inner surface. This reflective film not only has a high reflectance, but also has a high diffusibility. For this reason, the light emitted into the integrating sphere light receiver 102 is repeatedly reflected on the inner surface of the integrating sphere light receiver 102, thereby showing a uniform light intensity distribution on the entire inner surface. Since the structure of the integrating sphere light receiver 102 is known, further description is omitted.
　入射口１０２ａと出射口１０２ｂは、積分球受光器１０２の中心を通過する同じ直線上に中心が位置し、互いに対向する位置関係にある。白色板１０６は、出射口１０２ｂに１０°傾けて取り付けられている。これにより、対向する入射口１０２ａより入射した光が、積分球受光器１０２から再び出射しないようになっている。 The center of the entrance 102a and the exit 102b are located on the same straight line passing through the center of the integrating sphere light receiver 102 and are in a positional relationship facing each other. The white plate 106 is attached to the emission port 102b with an inclination of 10 °. As a result, light incident from the opposite incident port 102a is prevented from being emitted from the integrating sphere light receiver 102 again.
　光波長変換層３０は、入射口１０２ａから少し離れた場所に配置される。光波長変換層３０には、変換した２次光の波長と同じ波長に分光した光を入射させ、透過した光を積分球受光器１０２で測定する。このように、入射させる光の波長を選択することにより光波長変換層３０が１次光を吸収する影響を除外することができる。 The light wavelength conversion layer 30 is disposed at a position slightly away from the incident port 102a. Into the light wavelength conversion layer 30, the light split to the same wavelength as that of the converted secondary light is incident, and the transmitted light is measured by the integrating sphere light receiver 102. Thus, the influence of the light wavelength conversion layer 30 absorbing the primary light can be excluded by selecting the wavelength of the incident light.
　以下、光波長変換層３０を透過する光を「全体光」という。出射口１０２ｂに白色板１０６がある場合には、積分球受光器１０２は「全体光」を測定できる。 Hereinafter, the light transmitted through the light wavelength conversion layer 30 is referred to as “total light”. When there is a white plate 106 at the exit port 102b, the integrating sphere light receiver 102 can measure “total light”.
　入射口１０２ａと出射口１０２ｂは、同じ開孔径であることが必要であり、本実施形態ではそれぞれφ２０の開孔径を有している。出射口１０２ｂに配置されている白色板１０６を取り除くと、「直進光」は出射口１０２ｂより積分球の外に出る。残った「拡散光」が積分球内で反射して積分球受光器１０２で測定される。 The entrance port 102a and the exit port 102b are required to have the same aperture diameter, and in this embodiment, each has an aperture diameter of φ20. When the white plate 106 disposed at the exit port 102b is removed, “straight light” exits the integrating sphere from the exit port 102b. The remaining “diffused light” is reflected in the integrating sphere and measured by the integrating sphere receiver 102.
　「拡散率」は、以下の式で算出される。
　「拡散率」＝「拡散光」透過率／「全体光」透過率 The “diffusion rate” is calculated by the following formula.
“Diffusion rate” = “diffuse light” transmittance / “total light” transmittance
　測定口１０２ｃは、入射口１０２ａおよび出射口１０２ｂと離間した積分球受光器１０２の表面に設けられる。測定口１０２ｃには、光度計１０４が取り付けられる。積分球受光器１０２の内面は光度分布が均一となるため、光度計１０４は、均一となった平均光度を検出する。 The measurement port 102c is provided on the surface of the integrating sphere light receiver 102 which is separated from the entrance port 102a and the exit port 102b. A photometer 104 is attached to the measurement port 102c. Since the luminous intensity distribution on the inner surface of the integrating sphere light receiver 102 is uniform, the photometer 104 detects the uniform average luminous intensity.
　図３（ａ）は、全体光の平均光度を測定するときの測定システム１００を示している。以下、測定システム１００では、波長が６００ｎｍの光が光波長変換層３０を透過する割合、透過率を光度計１０４で測定した。この場合、出射口１０２ｂは白色板１０６で遮蔽されている。白色板１０６は、硫酸バリウムで形成されており、この白色板１０６を出射口１０２ｂに取り付けることで、出射口１０２ｂに到達した光を再び積分球受光器１０２の内部に拡散反射する。したがって、積分球受光器１０２の内部は「全体光」が均一に拡散反射する。 FIG. 3 (a) shows the measurement system 100 when measuring the average luminous intensity of the whole light. Hereinafter, in the measurement system 100, the ratio and transmittance of light having a wavelength of 600 nm transmitted through the optical wavelength conversion layer 30 were measured with the photometer 104. In this case, the emission port 102 b is shielded by the white plate 106. The white plate 106 is made of barium sulfate. By attaching the white plate 106 to the exit port 102b, the light that has reached the exit port 102b is diffusely reflected again into the integrating sphere light receiver 102. Therefore, “total light” is diffusely reflected uniformly within the integrating sphere light receiver 102.
　最初に、測定システム１００では、出射口１０２ｂを白色板１０６で遮蔽し、波長が６００ｎｍの光の光度を光度計１０４で測定し、このときの光度を１００とした。次に、図３（ａ）に示すように、測定システム１００の光路の途中、入射口１０２ａの前方に光波長変換層３０を設置し、同様に光度計１０４で光度を測定する。このときの光度を、最初に測定した光度を１００として比較し、その相対値を「全体光」の透過率とした。次に、図６（ｂ）に示すように、出射口１０２ｂの白色板１０６を取り除き、同様に光度計１０４で光度を測定する。このときの光度を、最初に測定した光度を１００として比較し、その相対値を「拡散光」の透過率とした。 First, in the measurement system 100, the exit port 102b is shielded by the white plate 106, the luminous intensity of light having a wavelength of 600 nm is measured by the photometer 104, and the luminous intensity at this time is taken as 100. Next, as shown in FIG. 3A, the light wavelength conversion layer 30 is installed in front of the entrance 102 a in the middle of the optical path of the measurement system 100, and the light intensity is similarly measured by the photometer 104. The luminous intensity at this time was compared with the first measured luminous intensity as 100, and the relative value was defined as the transmittance of “total light”. Next, as shown in FIG. 6B, the white plate 106 at the emission port 102b is removed, and the luminous intensity is measured by the photometer 104 in the same manner. The light intensity at this time was compared with the light intensity measured first as 100, and the relative value was defined as the transmittance of “diffuse light”.
　拡散率は、測定した各透過率から以下の式で算出される。
　拡散率＝（「拡散光」透過率／「全体光」透過率）×１００ The diffusivity is calculated from the measured transmittances by the following formula.
Diffusivity = (“diffuse light” transmittance / “total light” transmittance) × 100
　発光装置１０を自動車用灯具に用いるためには、光学特性の中でも特に輝度を高くすることが重要である。発光装置１０の輝度は輝度計を用いて測定した。発光装置１０に８５０ｍＡの電流を印加して１０分間点灯し、輝度計（（株）トプコンテクノハウス製ＳＲ－３０）を用いて視野角０．２°で測定した。そして、輝度が４０ｃｄ／ｍｍ２以上を合格、４０ｃｄ／ｍｍ２未満を不合格とした。 In order to use the light-emitting device 10 for an automobile lamp, it is important to increase the luminance among optical characteristics. The luminance of the light emitting device 10 was measured using a luminance meter. A current of 850 mA was applied to the light emitting device 10 to light it for 10 minutes, and measurement was performed at a viewing angle of 0.2 ° using a luminance meter (SR-30 manufactured by Topcon Technohouse Co., Ltd.). And the brightness | luminance set 40 cd / mm < 2 > or more as pass, and made less than 40 cd / mm < 2 > fail.
　図４（ａ）は、比較例１、比較例２、および実施例に係る光波長変換層３０の透過率と拡散率との関係を示す図である。光波長変換層３０の透過率または拡散率が異なる以外は、比較例１、比較例２、および実施例で共通して上述の発光装置１０を用いた。したがって、並設された複数の発光素子２０を仕切る仕切り枠５０ｂが設けられており、また、発光素子２０の発光面２０ａには複数の電極２０ｃが設けられている。 FIG. 4A is a diagram showing the relationship between the transmittance and the diffusivity of the optical wavelength conversion layer 30 according to Comparative Example 1, Comparative Example 2, and Examples. The above-described light emitting device 10 was used in common in Comparative Example 1, Comparative Example 2, and Examples, except that the transmittance or diffusivity of the light wavelength conversion layer 30 was different. Therefore, a partition frame 50b that partitions the plurality of light emitting elements 20 arranged side by side is provided, and a plurality of electrodes 20c are provided on the light emitting surface 20a of the light emitting element 20.
　比較例１に係る発光装置１０では、光波長変換層３０の透過率が６０％、拡散率が７０％となっている。比較例２に係る発光装置１０では、光波長変換層３０の透過率が５０％、拡散率が８０％となっている。実施例に係る発光装置１０では、光波長変換層３０の透過率が６０％、拡散率が８０％となっている。このため実施例に係る光波長変換層３０に対し、比較例１に係る光波長変換層３０は、低拡散率となっている。また実施例に係る光波長変換層３０に対し、比較例２に係る光波長変換層３０は、低透過率となっている。 In the light emitting device 10 according to Comparative Example 1, the transmittance of the light wavelength conversion layer 30 is 60% and the diffusivity is 70%. In the light emitting device 10 according to Comparative Example 2, the transmittance of the light wavelength conversion layer 30 is 50%, and the diffusivity is 80%. In the light emitting device 10 according to the example, the transmittance of the light wavelength conversion layer 30 is 60% and the diffusivity is 80%. For this reason, the optical wavelength conversion layer 30 according to Comparative Example 1 has a low diffusivity compared to the optical wavelength conversion layer 30 according to the example. Further, the light wavelength conversion layer 30 according to Comparative Example 2 has a lower transmittance than the light wavelength conversion layer 30 according to the example.
　図４（ｂ）は、比較例１、比較例２、および実施例に係る発光装置１０の各試験における結果を示す図である。比較例１、比較例２、および実施例に係る発光装置１０を用いて、個別調光性能、発光素子２０間の輝度ムラ、発光素子２０内の輝度ムラ、および輝度の高さ、の各々の項目について所定の基準を満たすか否かの試験を行った。 FIG. 4B is a diagram showing the results of each test of the light emitting device 10 according to Comparative Example 1, Comparative Example 2, and Example. Using the light emitting device 10 according to Comparative Example 1, Comparative Example 2, and Example, each of individual dimming performance, luminance unevenness between the light emitting elements 20, luminance unevenness in the light emitting elements 20, and high brightness The items were tested to see if they met the prescribed criteria.
　図４（ｂ）に示すように、個別調光性能については、いずれかの発光素子２０を消灯させたときに隣接する点灯中の発光素子２０からの光が消灯した発光素子２０の遮光領域にどれほど入り込んでいるかを目視によって確認し、許容範囲か否かを判定した。発光素子２０間の輝度ムラは、隣接する２つの発光素子２０の各々の発光面２０ａの間の領域での最大輝度と最低輝度の差が所定の基準を満たしているか否かを判定した。発光素子２０内の輝度ムラは、発光素子２０の発光面２０ａの投影領域での最大輝度と最低輝度の差が所定の基準を満たしているか否かを判定した。輝度の高さは、発光装置１０の発光時に測定された輝度が所定の値以上か否かを判定した。 As shown in FIG. 4B, regarding individual dimming performance, when any one of the light emitting elements 20 is turned off, the light from the adjacent light emitting element 20 is turned off in the light shielding area of the light emitting element 20. It was confirmed by visual observation how much it entered, and it was determined whether or not it was within an allowable range. The luminance unevenness between the light emitting elements 20 was determined whether or not the difference between the maximum luminance and the minimum luminance in the region between the light emitting surfaces 20a of the two adjacent light emitting elements 20 satisfies a predetermined criterion. As for the luminance unevenness in the light emitting element 20, it was determined whether or not the difference between the maximum luminance and the minimum luminance in the projection area of the light emitting surface 20a of the light emitting element 20 satisfies a predetermined standard. As for the height of the luminance, it was determined whether or not the luminance measured when the light emitting device 10 emitted light was equal to or higher than a predetermined value.
　図５（ａ）は、発光素子２０のみで測定したときの輝度ムラを示す図である。図５（ｂ）は、理解を容易にすべく、図５（ａ）の横軸に発光素子２０の幅を合わせたときの発光素子２０の発光面２０ａを示す図である。図５（ａ）に示すように、電極２０ｃが設けられた個所で、輝度が大きく低下していることが分かる。 FIG. 5A is a diagram showing luminance unevenness when measured with the light emitting element 20 alone. FIG. 5B is a diagram illustrating the light emitting surface 20a of the light emitting element 20 when the width of the light emitting element 20 is aligned with the horizontal axis of FIG. 5A for easy understanding. As shown in FIG. 5A, it can be seen that the luminance is greatly reduced at the portion where the electrode 20c is provided.
　図６（ａ）は、実施例に係る光波長変換層３０と比較例１に係る光波長変換層３０の各々を用いて測定したときの発光素子２０内の輝度ムラを示す図である。ラインＬ０は実施例に係る光波長変換層３０を用いたときの輝度ムラを示しており、ラインＬ１は比較例１に係る光波長変換層３０を用いたときの輝度ムラを示している。図６（ｂ）は、理解を容易にすべく、図６（ａ）の横軸に発光素子２０の幅を合わせたときの発光素子２０の発光面２０ａを示す図である。 FIG. 6A is a diagram showing luminance unevenness in the light emitting element 20 when measured using each of the light wavelength conversion layer 30 according to the example and the light wavelength conversion layer 30 according to Comparative Example 1. FIG. A line L0 indicates luminance unevenness when the light wavelength conversion layer 30 according to the example is used, and a line L1 indicates luminance unevenness when the light wavelength conversion layer 30 according to the comparative example 1 is used. FIG. 6B is a diagram showing the light emitting surface 20a of the light emitting element 20 when the width of the light emitting element 20 is aligned with the horizontal axis of FIG. 6A for easy understanding.
　図６（ａ）に示す通り、比較例１に係る低拡散率の光波長変換層３０を用いた場合、図５（ａ）に示す発光素子２０そのままの輝度ムラよりは改善しているものの、やはり電極２０ｃが設けられた個所で輝度が低下していることが分かる。これに対し、実施例に係る光波長変換層３０を用いた場合、電極２０ｃが設けられた個所での輝度の低下はほとんどみられなかった。このため、拡散率を高めることが、発光素子２０の発光面２０ａに設けられた電極２０ｃによる輝度低下の抑制に高い効果があることが分かる。 As shown in FIG. 6A, when the light wavelength conversion layer 30 having a low diffusivity according to the comparative example 1 is used, the luminance unevenness of the light emitting element 20 shown in FIG. It can also be seen that the luminance is lowered at the location where the electrode 20c is provided. On the other hand, when the light wavelength conversion layer 30 according to the example was used, the luminance was hardly reduced at the portion where the electrode 20c was provided. For this reason, it can be seen that increasing the diffusivity has a high effect in suppressing luminance reduction by the electrode 20c provided on the light emitting surface 20a of the light emitting element 20.
　図７（ａ）は、実施例に係る光波長変換層３０と比較例２に係る光波長変換層３０の各々を用いて測定したときの発光素子２０間の輝度ムラを示す図である。ラインＬ０は実施例に係る光波長変換層３０を用いたときの輝度ムラを示しており、ラインＬ１は比較例２に係る光波長変換層３０を用いたときの輝度ムラを示している。図７（ｂ）は、理解を容易にすべく、図７（ａ）の横軸に発光装置１０の幅を合わせたときの発光装置１０の上面図である。 FIG. 7A is a diagram showing luminance unevenness between the light emitting elements 20 when measured using each of the light wavelength conversion layer 30 according to the example and the light wavelength conversion layer 30 according to Comparative Example 2. FIG. A line L0 indicates luminance unevenness when the light wavelength conversion layer 30 according to the example is used, and a line L1 indicates luminance unevenness when the light wavelength conversion layer 30 according to comparative example 2 is used. FIG. 7B is a top view of the light emitting device 10 when the width of the light emitting device 10 is aligned with the horizontal axis of FIG. 7A for easy understanding.
　図７（ａ）に示すように、比較例２に係る光波長変換層３０を用いた場合、発光素子２０の発光面２０ａの中心から発光素子２０の間に進むにしたがって輝度が徐々に低下していくことが分かる。一方、実施例に係る光波長変換層３０を用いた場合、発光面２０ａの輝度が発光面２０ａの間の領域に分散しているのが分かる。発光面２０ａの間の領域で輝度が低下している個所があるが、その範囲は非常に狭く、比較例２に係る光波長変換層３０を用いた場合に比べて輝度ムラが判別しにくくなっていることが分かる。 As shown in FIG. 7A, when the light wavelength conversion layer 30 according to the comparative example 2 is used, the luminance gradually decreases as it goes from the center of the light emitting surface 20 a of the light emitting element 20 to between the light emitting elements 20. You can see that On the other hand, when the light wavelength conversion layer 30 according to the example is used, it can be seen that the luminance of the light emitting surface 20a is dispersed in the region between the light emitting surfaces 20a. Although there is a portion where the luminance is reduced in the region between the light emitting surfaces 20a, the range is very narrow, and it is difficult to discriminate luminance unevenness compared to the case where the light wavelength conversion layer 30 according to Comparative Example 2 is used. I understand that
　図４（ｂ）に戻る。図４（ｂ）に示すように、個別調光性能および発光素子２０間の輝度ムラについては、比較例１、比較例２、実施例いずれの発光装置１０も基準を満たしていた。実施例に係る発光装置１０は、発光装置１０内の輝度ムラおよび発光装置１０の輝度の高さも基準を満たしていた。しかし、低拡散率の光波長変換層３０を持つ比較例１は、発光素子２０内の輝度ムラが基準を満たさなかった。また、低透過率の光波長変換層３０を持つ比較例２は、発光装置１０の輝度の高さが所定の値未満であった。以上より、光波長変換層３０は、発光素子２０が発する光を変換した２次光（例えば黄色光）の透過率が６０％以上、且つ拡散率が８０％以上に設けられていると、発光装置１０において適切に発光できることが判明した。 Return to FIG. 4 (b). As shown in FIG. 4B, the light-emitting devices 10 of Comparative Example 1, Comparative Example 2, and Example all satisfied the standards for individual dimming performance and luminance unevenness between the light-emitting elements 20. In the light emitting device 10 according to the example, the luminance unevenness in the light emitting device 10 and the luminance height of the light emitting device 10 also satisfied the standards. However, in Comparative Example 1 having the light wavelength conversion layer 30 with a low diffusivity, the luminance unevenness in the light emitting element 20 did not satisfy the standard. In Comparative Example 2 having the light wavelength conversion layer 30 with low transmittance, the luminance of the light emitting device 10 was less than a predetermined value. As described above, the light wavelength conversion layer 30 emits light when the transmittance of the secondary light (for example, yellow light) converted from the light emitted from the light emitting element 20 is 60% or more and the diffusivity is 80% or more. It has been found that the device 10 can emit light appropriately.
　図８（ａ）は、比較例３および実施例に係る光波長変換層３０の透過率、拡散率、および枠５０表面の反射率との関係を示す図である。この場合においても、光波長変換層３０以外は、比較例３および実施例で共通して上述の発光装置１０を用いた。 FIG. 8A is a diagram showing the relationship between the transmittance and diffusivity of the optical wavelength conversion layer 30 according to the comparative example 3 and the example, and the reflectance of the surface of the frame 50. Also in this case, except for the light wavelength conversion layer 30, the above-described light emitting device 10 was used in common in Comparative Example 3 and the example.
　比較例３および実施例の光波長変換層３０は、透過率が５０％、拡散率が８０％となっている。枠５０の反射率は、６００ｎｍの光を照射したときの反射率を測定した。比較例３に係る発光装置１０では、枠５０の表面に反射膜を設けず、実施例に係る発光装置１０では、枠５０の表面に酸化バリウムなどによる反射膜を設けた。このため、比較例３での枠５０の反射率は３５％であり、実施例での枠５０の反射率は５０％であった。 The light wavelength conversion layer 30 of Comparative Example 3 and Examples has a transmittance of 50% and a diffusivity of 80%. The reflectance of the frame 50 was measured when the light of 600 nm was irradiated. In the light emitting device 10 according to Comparative Example 3, no reflective film was provided on the surface of the frame 50, and in the light emitting device 10 according to the example, a reflective film made of barium oxide or the like was provided on the surface of the frame 50. For this reason, the reflectance of the frame 50 in the comparative example 3 was 35%, and the reflectance of the frame 50 in the example was 50%.
　図８（ｂ）は、比較例３および実施例に係る発光装置１０の各試験における結果を示す図である。試験項目は図４（ｂ）に示すものと同じである。図８（ｂ）に示すように、実施例に係る発光装置１０は、個別調光性能、発光素子２０間の輝度ムラ、発光素子２０内の輝度ムラ、および発光装置１０の輝度の高さすべてにおいて基準を満たした。一方、比較例３は、個別調光性能、発光素子２０間の輝度ムラ、発光素子２０内の輝度ムラにおいて基準を満たしたが、発光装置１０の輝度の高さが基準を見なさなかった。このため、枠５０に反射膜を設けて反射率を高めることが、発光装置１０の輝度向上に効果があることが分かる。 FIG. 8B is a diagram showing the results of each test of the light emitting device 10 according to the comparative example 3 and the example. The test items are the same as those shown in FIG. As illustrated in FIG. 8B, the light emitting device 10 according to the example has all the individual dimming performance, the luminance unevenness between the light emitting elements 20, the luminance unevenness in the light emitting element 20, and the brightness of the light emitting device 10. Met the criteria. On the other hand, Comparative Example 3 satisfied the standards in the individual dimming performance, the luminance unevenness between the light emitting elements 20, and the luminance unevenness in the light emitting element 20, but the high luminance of the light emitting device 10 did not consider the reference. For this reason, it can be seen that providing a reflective film on the frame 50 to increase the reflectance has an effect of improving the luminance of the light emitting device 10.
　図９（ａ）は、比較例４－１、比較例４－２、実施例４－１、および実施例４－２に係る光波長変換層３０の透過率、拡散率、および枠５０表面の反射率との関係を示す図である。この場合においても、光波長変換層３０以外は、比較例および実施例で共通して上述の発光装置１０を用いた。 FIG. 9A shows the transmittance, diffusivity, and surface of the frame 50 of the optical wavelength conversion layer 30 according to Comparative Example 4-1, Comparative Example 4-2, Example 4-1, and Example 4-2. It is a figure which shows the relationship with a reflectance. Also in this case, except for the light wavelength conversion layer 30, the above-described light emitting device 10 was used in common in the comparative example and the example.
　比較例４－１、比較例４－２、実施例４－１、および実施例４－２の光波長変換層３０は、透過率が８０％、拡散率が９９．７％となっている。比較例４－１では、光波長変換層３０の厚みが２０μｍのものを使用した。比較例４－２では光波長変換層３０の厚みが６０００μｍのものを使用した。実施例４－１では、光波長変換層３０の厚みが３０μｍのものを使用した。実施例４－２では、光波長変換層３０の厚みが５０００μｍのものを使用した。 The light wavelength conversion layers 30 of Comparative Example 4-1, Comparative Example 4-2, Example 4-1, and Example 4-2 have a transmittance of 80% and a diffusivity of 99.7%. In Comparative Example 4-1, a light wavelength conversion layer 30 having a thickness of 20 μm was used. In Comparative Example 4-2, a light wavelength conversion layer 30 having a thickness of 6000 μm was used. In Example 4-1, a light wavelength conversion layer 30 having a thickness of 30 μm was used. In Example 4-2, the light wavelength conversion layer 30 having a thickness of 5000 μm was used.
　図９（ｂ）は、比較例４－１、比較例４－２、実施例４－１、および実施例４－２に係る発光装置１０の各試験における結果を示す図である。試験項目は図４（ｂ）に示すものと同じである。図８（ｂ）に示すように、実施例４－１および実施例４－２に係る発光装置１０は、個別調光性能、発光素子２０間の輝度ムラ、発光素子２０内の輝度ムラ、および発光装置１０の輝度の高さすべてにおいて基準を満たした。一方、比較例４－１に係る光波長変換層３０は、薄すぎたため割れが発生し、各試験を行うことができなかった。また、比較例４－２に係る発光装置１０では、個別調光性能、発光素子２０間の輝度ムラ、発光素子２０内の輝度ムラでは基準を満たしたものの、発光装置１０の輝度の高さでは基準を満たさなかった。このため、光波長変換層３０は、３０μｍ以上５０００μｍ以下の厚みを有することが好ましいことが判明した。 FIG. 9B is a diagram showing the results of each test of the light emitting device 10 according to Comparative Example 4-1, Comparative Example 4-2, Example 4-1, and Example 4-2. The test items are the same as those shown in FIG. As shown in FIG. 8B, the light-emitting device 10 according to Example 4-1 and Example 4-2 includes individual dimming performance, luminance unevenness between the light-emitting elements 20, luminance unevenness within the light-emitting element 20, and The standard was satisfied in all the brightness heights of the light emitting device 10. On the other hand, since the light wavelength conversion layer 30 according to Comparative Example 4-1 was too thin, cracks occurred, and each test could not be performed. Further, in the light emitting device 10 according to Comparative Example 4-2, the individual dimming performance, the luminance unevenness between the light emitting elements 20 and the luminance unevenness in the light emitting element 20 met the standard, but the brightness of the light emitting device 10 was high. The standard was not met. For this reason, it was found that the light wavelength conversion layer 30 preferably has a thickness of 30 μm or more and 5000 μm or less.
　本発明は上述の各実施形態に限定されるものではなく、各実施形態の各要素を適宜組み合わせたものも、本発明の実施形態として有効である。また、当業者の知識に基づいて各種の設計変更等の変形を各実施形態に対して加えることも可能であり、そのような変形が加えられた実施形態も本発明の範囲に含まれうる。以下、そうした例をあげる。 The present invention is not limited to the above-described embodiments, and an appropriate combination of the elements of each embodiment is also effective as an embodiment of the present invention. Various modifications such as design changes can be added to each embodiment based on the knowledge of those skilled in the art, and embodiments to which such modifications are added can also be included in the scope of the present invention. Here are some examples.
　ある変形例では、発光素子２０は、例えばサファイアなどの結晶成長用基板上に半導体層を単結晶成長させることにより形成される。本変形例に係る発光素子２０は、この結晶成長用基板が除去されずに残されたものが使用されている。このため、この結晶成長用基板を導波した光が発光素子の側面からも出射する。また、側面２０ｂのうち半導体層の部分からも光は発せられる。したがって側面２０ｂは、発光面としても機能する。 In a modification, the light emitting element 20 is formed by growing a semiconductor layer on a crystal growth substrate such as sapphire, for example. As the light emitting element 20 according to this modification, the one that is left without removing the crystal growth substrate is used. For this reason, the light guided through the crystal growth substrate is emitted also from the side surface of the light emitting element. Light is also emitted from the semiconductor layer portion of the side surface 20b. Therefore, the side surface 20b also functions as a light emitting surface.
　この場合、垂直面５０ｄは、実装基板４０の上面４０ａから発光面２０ａまでの高さより低い高さを有する。なお、垂直面５０ｄが削除されてもよい。この場合、実装基板４０は、一対の傾斜面５０ｃと底面とによる三角形の断面を有する形状に形成される。これにより、側面２０ｂから出射される光も出射面３０ａに向けて反射することができ、光の取り出し効率をさらに高めることができる。 In this case, the vertical surface 50d has a height lower than the height from the upper surface 40a of the mounting substrate 40 to the light emitting surface 20a. Note that the vertical surface 50d may be deleted. In this case, the mounting substrate 40 is formed in a shape having a triangular cross section with a pair of inclined surfaces 50c and a bottom surface. Thereby, the light emitted from the side surface 20b can also be reflected toward the emission surface 30a, and the light extraction efficiency can be further increased.
　ある別の変形例では、光波長変換層３０に代えて、板状の光波長変換部材が設けられる。この光波長変換部材もまた、発光素子２０の発光面２０ａに対向し且つ発光面２０ａと平行に配置される。したがって、発光素子２０と同数の光波長変換部材が用いられる。 In another variation, a plate-shaped light wavelength conversion member is provided in place of the light wavelength conversion layer 30. This light wavelength conversion member is also arranged opposite to the light emitting surface 20a of the light emitting element 20 and parallel to the light emitting surface 20a. Therefore, the same number of light wavelength conversion members as the light emitting elements 20 are used.
　光波長変換部材は、いわゆる発光セラミック、または蛍光セラミックと呼ばれるものであり、青色光によって励起される蛍光体であるＹＡＧ（Yttrium Aluminum Garnet）粉末を用いて作成されたセラミック素地を焼結することにより得ることができる。このような光波長変換セラミックの製造方法は公知であることから詳細な説明は省略する。なお、光波長変換部材は、焼結セラミックに限定されず、例えばアモルファス、多結晶、単結晶のものを含み、結晶構造などによって限定されない。また、光波長変換部材には、透明なものが採用されている。本実施形態において「透明」とは、変換波長域の光の全光線透過率が４０％以上のことを意味するものとする。これにより、発光素子２０が発する光をより効率的に変換することができる。 The light wavelength conversion member is a so-called luminescent ceramic or fluorescent ceramic, and is obtained by sintering a ceramic substrate made of YAG (Yttrium Aluminum Garnet) powder, which is a phosphor excited by blue light. Obtainable. Since the manufacturing method of such a light wavelength conversion ceramic is well-known, detailed description is abbreviate | omitted. The light wavelength conversion member is not limited to a sintered ceramic, and includes, for example, amorphous, polycrystalline, and single crystal, and is not limited by the crystal structure. Moreover, the transparent thing is employ | adopted for the optical wavelength conversion member. In the present embodiment, “transparent” means that the total light transmittance of light in the conversion wavelength region is 40% or more. Thereby, the light which the light emitting element 20 emits can be converted more efficiently.
　この場合も、光波長変換層部材は、発光素子２０が発する光を変換した２次光（例えば黄色光）の透過率が６０％以上、且つ拡散率が８０％以上に設けられる。これにより、仕切り枠５０ｂまたは発光面２０ａの電極２０ｃによる輝度ムラの発生を抑制することができる。 Also in this case, the light wavelength conversion layer member is provided such that the transmittance of secondary light (for example, yellow light) obtained by converting the light emitted from the light emitting element 20 is 60% or more and the diffusivity is 80% or more. Thereby, generation | occurrence | production of the brightness nonuniformity by the electrode 20c of the partition frame 50b or the light emission surface 20a can be suppressed.
　複数の光波長変換部材の各々は、４つの傾斜面５０ｃに載置される。このとき光波長変換部材は、４つの傾斜面５０ｃに接着され固定される。光波長変換部材の側面は、出射面に近づくほど光波長変換部材の中心からの距離が広がるよう傾斜する。光波長変換部材は、入射面に対する４つの側面の各々の傾斜角度が、発光面２０ａに対する傾斜面５０ｃの傾斜角度、および発光面２０ａに対する傾斜面５０ｃの傾斜角度と同一となるよう形成されている。このため、光波長変換部材を外枠５０ａの傾斜面５０ｃおよび仕切り枠５０ｂの傾斜面５０ｃに載置すると、光波長変換部材の４つの側面は、それぞれ外枠５０ａの傾斜面５０ｃおよび仕切り枠５０ｂの傾斜面５０ｃに接する。これにより、発光素子２０が発する光をより有効に利用することが可能となる。 Each of the plurality of light wavelength conversion members is placed on the four inclined surfaces 50c. At this time, the light wavelength conversion member is bonded and fixed to the four inclined surfaces 50c. The side surface of the light wavelength conversion member is inclined so that the distance from the center of the light wavelength conversion member increases as it approaches the emission surface. The light wavelength conversion member is formed so that the inclination angle of each of the four side surfaces with respect to the incident surface is the same as the inclination angle of the inclined surface 50c with respect to the light emitting surface 20a and the inclination angle of the inclined surface 50c with respect to the light emitting surface 20a. . For this reason, when the light wavelength conversion member is placed on the inclined surface 50c of the outer frame 50a and the inclined surface 50c of the partition frame 50b, the four side surfaces of the light wavelength conversion member are the inclined surface 50c of the outer frame 50a and the partition frame 50b, respectively. In contact with the inclined surface 50c. Thereby, the light emitted from the light emitting element 20 can be used more effectively.
　１０　発光装置、　２０　発光素子、　２０ａ　発光面、　２０ｂ　側面、　２０ｃ　電極、　３０　光波長変換層、　３０ａ　出射面、　４０　実装基板、　４０ａ　上面、　５０　枠、　５０ａ　外枠、　５０ｂ　仕切り枠、　５０ｃ　傾斜面、　５０ｄ　垂直面、　１００　測定システム、　１０２　積分球受光器、　１０２ａ　入射口、　１０２ｂ　出射口、　１０２ｃ　測定口、　１０４　光度計、　１０６　白色板。 10 light emitting device, 20 light emitting element, 20a light emitting surface, 20b side surface, 20c electrode, 30 light wavelength conversion layer, 30a light emitting surface, 40 mounting substrate, 40a top surface, 50 frame, 50a outer frame, 50b partition frame, 50c inclined surface, 50d vertical plane, 100 measurement system, 102 integrating sphere receiver, 102a entrance, 102b exit, 102c measurement, 104 photometer, 106 white plate.
　本発明は、発光装置に利用できる。 The present invention can be used for a light emitting device.

Claims (6)

  1. 　並設された複数の半導体発光素子を仕切る仕切り枠と、
    　前記複数の半導体発光素子の各々の発光面に対向して設けられた光波長変換層と、
    を備え、
    　前記光波長変換層は、変換した２次光の透過率が６０％以上、且つ前記光波長変換層から出射する全体光のうち前記半導体発光素子の光軸に対し所定角度以上で出射する拡散光の割合である拡散率が８０％以上であることを特徴とする発光装置。     A partition frame for partitioning a plurality of semiconductor light emitting elements arranged in parallel;
    A light wavelength conversion layer provided to face each light emitting surface of the plurality of semiconductor light emitting elements;
    With
    The light wavelength conversion layer has a transmittance of the converted secondary light of 60% or more, and out of the whole light emitted from the light wavelength conversion layer, diffused light emitted at a predetermined angle or more with respect to the optical axis of the semiconductor light emitting element. A light emitting device having a diffusion rate of 80% or more.
  2. 　前記仕切り枠は、端部に近づくほど厚みが減少するよう形成され、
    　前記光波長変換層は、前記仕切り枠の端部近傍において前記仕切り枠の表面に接して配置されることを特徴とする請求項１に記載の発光装置。     The partition frame is formed so that the thickness decreases as it approaches the end,
    The light-emitting device according to claim 1, wherein the light wavelength conversion layer is disposed in contact with a surface of the partition frame in the vicinity of an end of the partition frame.
  3. 　前記仕切り枠は、少なくとも一部の表面の反射率が７０％以上であることを特徴とする請求項１または２に記載の発光装置。 The light emitting device according to claim 1 or 2, wherein the partition frame has a reflectance of 70% or more of at least a part of a surface thereof.
  4. 　前記光波長変換層は、３０μｍ以上５０００μｍ以下の厚みを有することを特徴とする請求項１から３のいずれかに記載の発光装置。 The light-emitting device according to claim 1, wherein the light wavelength conversion layer has a thickness of 30 μm to 5000 μm.
  5. 　発光面に電極が形成された半導体発光素子と、
    　前記発光面に対向して配置された光波長変換層と、
    を備え、
    　前記光波長変換層は、変換した２次光の透過率が６０％以上、且つ前記光波長変換層から出射する全体光のうち前記半導体発光素子の光軸に対し所定角度以上で出射する拡散光の割合である拡散率が８０％以上であることを特徴とする発光装置。     A semiconductor light emitting device having an electrode formed on the light emitting surface;
    A light wavelength conversion layer disposed to face the light emitting surface;
    With
    The light wavelength conversion layer has a transmittance of the converted secondary light of 60% or more, and out of the whole light emitted from the light wavelength conversion layer, diffused light emitted at a predetermined angle or more with respect to the optical axis of the semiconductor light emitting element. A light emitting device having a diffusion rate of 80% or more.
  6. 　前記光波長変換層は、３０μｍ以上５０００μｍ以下の厚みを有することを特徴とする請求項５に記載の発光装置。 The light-emitting device according to claim 5, wherein the light wavelength conversion layer has a thickness of 30 μm or more and 5000 μm or less.
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