WO2020066077A1

WO2020066077A1 - Phosphor element, method for producing same, and lighting device

Info

Publication number: WO2020066077A1
Application number: PCT/JP2019/013259
Authority: WO
Inventors: 近藤　順悟; 直剛岡田; 雄一岩田; 浅井　圭一郎; 雄大鵜野
Original assignee: 日本碍子株式会社
Priority date: 2018-09-28
Filing date: 2019-03-27
Publication date: 2020-04-02
Also published as: WO2020065927A1

Abstract

[Problem] To increase the fluorescence intensity of emitted light and minimize color irregularity in emitted white light when excitation light is made to enter a reflective phosphor element and fluorescence is generated. [Solution] A phosphor element 1 is provided with: a phosphor section 2 that is provided with an entry surface 2a for excitation light, a facing surface 2b facing the entry surface, and a side surface 2c, that converts at least some excitation light entering the entry surface into fluorescence, and that causes the fluorescence to be emitted from the entry surface; a single low refractive index layer 3 that is present on the side surface 2c and the facing surface 2b of the phosphor section 2, and that has a lower refractive index than the refractive index of the phosphor section 2; and a single reflective film 4 that covers the surface of the low refractive index layer 3. The area AI of the entry surface 2a of the phosphor section 2 is larger than the area AR of the facing surface 2b.

Description

Phosphor element, its manufacturing method and lighting device

The present invention relates to a phosphor element, a method of manufacturing the same, and a lighting device that emits fluorescent light.

Recently, research on automotive headlights using laser light sources has been actively conducted, and one of them is a white light source combining a blue laser or an ultraviolet laser with a phosphor. By condensing the laser light, the light density of the excitation light can be increased, and by concentrating a plurality of laser lights on the phosphor, the light intensity of the excitation light can be increased. As a result, the luminous flux and the luminance can be simultaneously increased without changing the light emitting area. For this reason, a white light source combining a semiconductor laser and a phosphor has been attracting attention as a light source replacing the LED. For example, the fluorescent glass used in automotive headlights is Nippon Electric Glass Co., Ltd.'s "Lumiface" fluorescent glass, the National Research and Development Agency of Materials and Materials, Tamura Corporation, and Lightwave's YAG single crystal fluorescent glass. The body is considered.

蛍光 In the phosphor element described in Patent Document 1 (Patent 5,679,435), the width of the phosphor increases from the incident surface to the emission surface. The angle of inclination of the side surface of the phosphor is 15 degrees or more and 35 degrees or less. Then, a metal film is formed to accommodate the phosphor in a resin case and allow the inner surface of the case to function as a reflector portion. The phosphor is fixed to the bottom surface of the case by a sealing resin, and the side surface of the phosphor is covered with air.

In the phosphor element described in Patent Document 2 (Japanese Patent Application Laid-Open No. 2017-85038), the width of the phosphor increases from the incident surface to the emission surface, and the phosphor is accommodated in the through hole of the heat radiation member. Are bonded to the surface of the through-hole with a glass paste.

In the phosphor elements described in Patent Documents 3 to 7, excitation light is incident on the phosphor, the fluorescence and the excitation light are reflected and changed in direction in the phosphor, and emitted as white light from the phosphor.

Patent 5679435 JP-A-2017-85038 JP 2013-187043 JP 2014-98556 A WO 2017/217486 A1 JP-A-2015-50124 JP 2016-58624

In the phosphor elements described in

Patent Literatures

1 and 2, excitation light is made incident from the entrance surface of the phosphor, and excitation light and fluorescence are emitted from the exit surface opposite to the entrance surface, so that the optical path cannot be changed. , There are design limitations.

On the other hand, while the present inventor has been studying a reflective phosphor element that reflects light in the phosphor, the following problem has become apparent. That is, in order to increase the fluorescence intensity, it is necessary to increase the intensity of the excitation light. However, in the reflection type phosphor element, although the excitation light and the fluorescence are reflected and propagated in the phosphor, the number of times of reflection is large, and photons disappear due to absorption or scattering by reflection. For this reason, when the excitation light intensity is increased, the temperature of the phosphor increases, and the light intensity obtained is limited. Further, color unevenness sometimes occurred in white light emitted from the element. For this reason, it is necessary to keep the fluorescence intensity of the emitted light high during continuous use and to suppress color unevenness.

The object of the present invention is to increase the fluorescence intensity of emitted light and suppress color unevenness of emitted white light when exciting light is incident on the reflective phosphor element to generate fluorescence.

Another object of the present invention is to provide a manufacturing method which facilitates heat radiation from a phosphor portion when manufacturing a reflective phosphor element.

The phosphor element according to the present invention is a phosphor section having an excitation light incident surface, a facing surface and a side surface facing the incident surface, and at least a part of the excitation light incident on the incident surface. A phosphor part that converts the light into fluorescent light and emits the fluorescent light from the incident surface;
An integrated low-refractive-index layer having a refractive index lower than the refractive index of the phosphor section, on the side surface and the opposing surface of the phosphor section; and an integral low-refractive-index layer covering the surface of the low-refractive-index layer. A reflecting film is provided, and the area of the incident surface of the phosphor section is larger than the area of the facing surface.

The present invention also relates to a lighting device, comprising: a light source that oscillates a laser beam; and the phosphor element.

Further, the present invention is a phosphor portion having an incident surface of the excitation light, an opposing surface and a side surface facing the incident surface, and converts at least a part of the excitation light incident on the incident surface into fluorescent light. A phosphor portion that emits the fluorescent light from the incident surface; and an integral reflecting film that covers the phosphor portion, wherein the area of the incident surface of the phosphor portion is greater than the area of the facing surface. A method of manufacturing a large phosphor element,
Joining the second main surface of the phosphor substrate having a first main surface and a second main surface to a handle substrate,
Forming the phosphor portion by processing the first main surface of the phosphor substrate to form the opposing surface and the side surface;
A step of forming the reflection film so as to cover the facing surface and the side surface; and a step of separating the phosphor section from the handle substrate.

ADVANTAGE OF THE INVENTION According to this invention, in the fluorescent element which injects excitation light with respect to the incident surface of a fluorescent substance part, and emits excitation light and fluorescence from an incident surface, the fluorescence intensity of emitted light is maintained high and color unevenness is suppressed. can do.

Further, according to the manufacturing method of the present invention, in the phosphor element which emits excitation light to the incident surface of the phosphor portion and emits the excitation light and the fluorescence from the incident surface, on the side surface and the opposing surface of the phosphor portion In this case, an integral reflection film can be simultaneously formed of the same material without discontinuity, whereby heat radiation from the reflection film can be promoted.

According to Patent Document 6, a total reflection film and a reflection layer are formed on the main surface of a flat phosphor layer, and the width of the phosphor layer is constant. According to Patent Document 7, a reflection film is provided on a side surface of a ceramic phosphor, and a taper is provided on a side surface of a phosphor layer. However, the reflecting portion is plate-shaped and does not have a laminated structure with a low refractive index layer. Therefore, assuming that Patent Documents 6 and 7 are combined, a taper is provided on the side surface of the phosphor layer, a reflection film is provided on the side surface, and a low refractive index layer and a reflection film are provided on the main surface of the phosphor layer. Will be provided. However, with this structure, the effect of the present invention cannot be obtained although the result is as shown in FIG. 4 described later.

1A is a perspective view illustrating a phosphor element 1 according to an embodiment of the present invention, and FIG. 2B is a cross-sectional view of the phosphor element 1. (A) is a schematic diagram illustrating a light propagation path in the phosphor element 1, and (b) is a schematic diagram illustrating a light propagation path in the phosphor element 11 of the comparative example. (A) is a schematic diagram showing a light propagation path in the phosphor element 1, and (b) is a schematic diagram showing a light propagation path in the phosphor element 21 of the comparative example. It is a schematic diagram which shows the propagation path of the light in the fluorescent element 26 of a control example. FIG. 9 is a cross-sectional view illustrating a phosphor element 31 according to another embodiment of the present invention. It is a perspective view showing phosphor element 41 concerning other embodiments of the present invention. FIG. 4 is a cross-sectional view of a phosphor element 41. (A) shows a state in which a phosphor substrate 51 made of a phosphor is joined to a handle substrate 53, and (b) shows a state in which a plurality of phosphor portions 2 are formed by processing the phosphor substrate. . FIG. 4 is a perspective view showing a state in which a low refractive index layer 54 is provided on a bonding layer 52 and a phosphor section 2. FIG. 3 is a perspective view showing a state in which a reflection film 55 is provided on a low refractive index layer 54. It is sectional drawing which shows the phosphor element 61 which concerns on further another embodiment typically. It is sectional drawing which shows typically the fluorescent element 61A which concerns on another embodiment. It is sectional drawing which shows the phosphor element 61B which concerns on still another embodiment typically. 5 is a graph showing the relationship between the power efficiency of each phosphor element and the taper angle.

Hereinafter, the present invention will be described in more detail with reference to the drawings as appropriate.
In the phosphor element 1 shown in FIG. 1, the phosphor section 2 includes an incident surface 2a, an exit surface 2b, and four side surfaces 2c. As shown in FIG. 2B, in the cross section of the phosphor portion, the phosphor portion has a substantially trapezoidal shape, and the angle θ of the side surface 2c with respect to the incident surface 2a is an acute angle smaller than 90 °. The area AI of the incident surface 2a is larger than the area AR of the opposing surface 2b.

A low-refractive-index layer 3b is provided on the side surface 2c of the phosphor section 2, and a low-refractive-index layer 3a is provided on the opposing surface 2b. The low-refractive-

index layers

3a and 3b form an integrated low-refractive-index layer. The refractive index layer 3 is formed. In this example, the low refractive index layer 3 covers the entire surface of the side surface 2c and the opposing surface 2b of the phosphor section 2 with the same material. Further, in this example, a reflective film 4a is provided on the low refractive index layer 3a, and a reflective film 4b is provided on the low refractive index layer 3b, and the

reflective films

4a and 4b are integrally formed of the same material. 4 are formed. In this example, the reflection film 4 covers the low refractive index layer 3 over the entire surface.

Here, the reason why a high fluorescent intensity is obtained by the phosphor element of the present invention and color unevenness is suppressed will be further described.
As shown in FIG. 2A, in the phosphor element 1 of the present invention, excitation light incident as shown by an arrow A impinges on a large number of phosphor particles 5 dispersed in the phosphor part 2. . Then, fluorescence is emitted from each phosphor particle 5 as shown by arrows C and D. At this time, the fluorescent particles tend to emit fluorescence uniformly in all directions.

蛍光 Here, the fluorescent light emitted from the phosphor particles in the direction of the incident surface 2a is emitted from the incident surface 2a as it is. The fluorescent light emitted from the phosphor particles toward the opposing surface 2b is reflected by the opposing surface and exits from the incident surface 2a as it is. However, the fluorescent light emitted obliquely as shown by arrows C and D is reflected by the reflection film 4b and emitted from the incident surface 2a as shown by arrows E and B. At this time, if the area AI of the incident surface of the phosphor section 2 is larger than the area AR of the opposing surface, and the side surface 2c is inclined, the direction of the reflected light E is reduced by the inclination angle θ. 2a. As a result, the number of reflections until the fluorescent light exits from the incident surface 2a can be reduced.

On the other hand, according to the phosphor element 11 of the comparative example shown in FIG. 2B, the width of the phosphor section 12 is constant. The low refractive index layers 13a and 13b are provided on the side surface 12c and the opposing surface 12b of the phosphor element 12, and the low refractive index layers 13a and 13b form the integral low refractive index layer 13 with the same material. doing. A reflection film 14b is provided on the low-refractive-index layer 13b, and a reflection film 14a is provided on the low-refractive-index layer 13a. The

reflection films

14a and 14b are integrally formed of the same material. Has formed.

In this case, the fluorescent light F emitted from the phosphor particles 5 toward, for example, the side surface 12c is reflected as it is as G and returns to the particles 5, so that it is not reflected from the incident surface 12a. That is, since the side surface 12c and the incident surface 12a are perpendicular to each other, the function of directing the direction of the fluorescent light toward the incident surface 12a when reflecting the fluorescent light does not work. As a result, the number of fluorescence reflections increases. The reflectance at the reflective film is not 100%, and a part of the fluorescent light is absorbed by the reflective film. Therefore, if the number of reflections is large, the fluorescent light is attenuated, and the temperature rise of the reflective film deteriorates the exhaust heat from the phosphor part. As a result, the temperature of the phosphor increases, and the fluorescence intensity decreases.

Further, as shown in FIG. 3A, in the phosphor element of the present invention, of the fluorescence oscillated from the phosphor particles 5, the fluorescence H1 is not totally reflected by the low refractive index layer, Is refracted at the interface between the low refractive index layer 3 and the low refractive index layer 3a, is reflected by the reflection film 4a like H2, is refracted again at the interface between the fluorescent part 2 and the low refractive index layer 3a, and propagates through the fluorescent part 2. Then, the light exits from the incident surface 2a.

On the other hand, in the control example of FIG. 3B, the shape of the phosphor part 2 is the same as that of the phosphor part 2 of FIG. The low refractive index layer 23 is provided on the side surface 2c of the phosphor element 2. However, the low refractive index layer is not provided on the opposing surface 2b of the phosphor section 2. In addition, a reflective film 24b is provided on the low refractive index layer 23, and a reflective film 24a is provided on the facing surface 2b of the phosphor section 2, and the

reflective films

24a and 24b are integrated. The reflection film 24 is formed.

Also in this case, the fluorescent light reflected from the phosphor particles 5 toward the facing surface as shown by the arrow H1 is reflected by the reflection film 24a, propagates through the phosphor portion 2 as shown by the arrow H2, and is incident. The light exits from the surface 2a.

On the other hand, as shown in FIG. 3A, the fluorescent light emitted obliquely from the phosphor particles 5 toward the opposing surface as shown by the arrow J satisfies the total reflection condition in the low refractive index layer 3a. The light is totally reflected as indicated by an arrow J1 and further reflected at the interface between the low refractive index layer 3b and the phosphor portion 2 as indicated by an arrow J2, and exits from the incident surface 2a.

On the other hand, in the phosphor element 21 of FIG. 3B, the fluorescent light emitted obliquely from the phosphor particles 5 toward the opposing surface as shown by the arrow J is reflected on the opposing surface 2b. The light is reflected by the film 24a as indicated by an arrow J3, is further totally reflected by the interface between the low refractive index layer 23 and the phosphor part 2 as indicated by an arrow J4, and is emitted from the incident surface 2a. In this case, the amount of light energy absorbed by the reflection film 24a is large, and the temperature of the reflection film 24a rises, so that the exhaust heat of the phosphor part 2 is deteriorated and the temperature rises. Therefore, the intensity of the fluorescent light emitted from the incident surface 2a decreases due to the temperature quenching of the phosphor.

On the other hand, in the phosphor element 26 of the comparative example shown in FIG. 4, the shape of the phosphor part 2 is the same as that of the phosphor part 2 in FIG. The low refractive index layer 27 is provided on the opposing surface 2b of the phosphor element 2, but the low refractive index layer is not provided on the side surface 2c. The

reflection films

4a and 4b form an integral reflection film 4.

Also in this case, the fluorescence reflected from the phosphor particles 5 toward the opposite surface side as shown by the arrow H1 is reflected by the reflection film 4a, propagates through the phosphor portion 2 as shown by the arrow H2, and is incident. The light exits from the surface 2a.

On the other hand, as shown in FIG. 3A, the fluorescent light emitted obliquely from the phosphor particles 5 toward the opposing surface as shown by the arrow J is totally reflected as shown by the arrow J1 and further has a low refractive index layer. The light is totally reflected at the interface between the fluorescent material portion 3b and the phosphor portion 2 as indicated by an arrow J2, and is emitted from the incident surface 2a.

On the other hand, in the phosphor element 26 of FIG. 4, the fluorescent light emitted obliquely from the phosphor particles 5 toward the side as indicated by the arrow J is totally reflected by the reflection film 4b on the side as indicated by the arrow J5. The light is reflected and exits from the incident surface 2a. In this case, since the light is totally reflected by the reflection film 4b, the amount of light energy absorbed is large, and the temperature of the reflection film 4b and the reflection film 4a connected to the reflection film 4b rises, so that the exhaust heat of the phosphor part 2 is deteriorated. Causes temperature rise. Therefore, the intensity of the fluorescence emitted from the incident surface 2a decreases with time due to the temperature quenching of the phosphor.

The phosphor element of the present invention is a phosphor portion having an incident surface of excitation light, a facing surface facing the incident surface, and a side surface, wherein at least a part of the excitation light incident on the incident surface is fluorescent. And a phosphor part for emitting the fluorescent light from the incident surface.
Here, when the entire excitation light is converted into fluorescent light, only the fluorescent light is emitted from the incident surface. Alternatively, by converting part of the excitation light into fluorescence, the fluorescence and the excitation light can be emitted from the incident surface.

The phosphor constituting the phosphor section is not limited as long as it can convert excitation light into fluorescence, but may be phosphor glass, phosphor single crystal, or phosphor polycrystal.
In addition, a scattering material may be added to the phosphor to scatter the excitation light and the fluorescence, or holes may be provided in the phosphor. In this case, since the light incident on the phosphor is scattered in the phosphor, the emitted light (excitation light and fluorescence) is scattered, and the scattering angle is increased.

The scattering angle of the phosphor can be measured by, for example, a scatterometer “Mini-Diff” manufactured by Cybernet Systems. The scattering angle is defined as the full width angle that is 1 / e ^{2 of the} peak value from the transmission spectrum of the emitted light.
At this time, the scattering angle is preferably 5 degrees or more, and more preferably 10 degrees or more. However, the upper limit of the scattering angle of the phosphor constituting the phosphor portion is not particularly limited, but may be equal to or less than the numerical aperture (NA) of the emitted light, and may be equal to or less than 80 degrees from a practical viewpoint.

Phosphor glass is obtained by dispersing rare earth element ions in a base glass.
The base glass includes silica, boron oxide, calcium oxide, lanthanum oxide, barium oxide, zinc oxide, phosphorus oxide, aluminum fluoride, magnesium fluoride, calcium fluoride, strontium fluoride, and oxide glass containing barium chloride. Can be illustrated.
As the rare earth element ions dispersed in the phosphor glass, Tb, Eu, Ce, and Nd are preferable, but La, Pr, Sc, Sm, Er, Tm, Dy, Gd, and Lu may be used.

The phosphor _{_{_{_{monocrystal, Y 3 Al 5 O 12,}}}} Ba 5 Si 11 A l7 N 25, Tb 3 Al 5 O 12 and YAG (yttrium aluminum garnet) can be exemplified. A part of Y (yttrium) of YAG may be substituted by Lu. As a doping component to be doped into the phosphor single crystal, rare earth ions are preferable, and Tb, Eu, Ce, and Nd are particularly preferable. However, La, Pr, Sc, Sm, Er, Tm, Dy, Gd, and Lu are preferable. There may be.

Examples of the polycrystalline phosphor include TAG (terbium aluminum garnet), sialon, nitride, BOS (barium orthosilicate), and YAG (yttrium aluminum garnet). A part of Y (yttrium) of YAG may be substituted by Lu.
As a doping component to be doped in the phosphor polycrystal, rare earth ions are preferable, and Tb, Eu, Ce, and Nd are particularly preferable. However, La, Pr, Sc, Sm, Er, Tm, Dy, Gd, and Lu are preferable. Is also good.

The phosphor element of the present invention may be a non-grating type phosphor element that does not include a grating (diffraction grating) in the phosphor section, and the grating may be provided in the phosphor section.

(4) The phosphor section has at least an excitation light incident surface, a facing surface, and a side surface. The side surface is a surface extending between the incident surface and the facing surface. Here, the shape of the phosphor is not particularly limited. For example, the shapes of the incident surface and the opposing surface of the phosphor portion may be, for example, a polygon such as a circle, an ellipse, a triangle, a square, and a hexagon.

According to the present invention, there is provided an integrated low-refractive-index layer on the side surface and the opposing surface of the phosphor section, and having a lower refractive index than the phosphor section.

Here, the low-refractive-index layer is provided on the side surface and the opposing surface of the phosphor portion, but the integral low-refractive-index layer means that the low-refractive-index layers are continuous with each other. I do. However, the low-refractive-index layer does not need to cover the entire side surface and the entirety of the opposing surface, and it is acceptable that a part of the side surface and a part of the opposing surface are exposed without being covered by the low-refractive index layer. Shall be. However, also in this case, it is preferable that 90% or more of the entire area of the side surface and 90% or more of the entire area of the opposing surface are covered with the low refractive index layer. More preferably, it is covered by a rate layer.

材質 Examples of the material of the low refractive index layer include aluminum oxide, magnesium oxide, aluminum nitride, tantalum oxide, silicon oxide, silicon nitride, aluminum nitride, and silicon carbide. From the viewpoint of heat dissipation, the material of the low refractive index layer is most preferably aluminum oxide or magnesium oxide.

Also, the refractive index of the low refractive index layer is lower than the refractive index of the phosphor, but in this case, the total reflection due to the refractive index difference between the phosphor and the low refractive index layer can be utilized, and The reflected light component can be reduced, and light can be prevented from being absorbed by reflection by the reflection film. The refractive index of the low refractive index layer is preferably 1.7 or less, and more preferably 1.6 or less. There is no particular lower limit for the refractive index of the low refractive index layer, and it is 1 or more, but it is practically 1.4 or more. Further, the difference between the refractive index of the phosphor part and the refractive index of the low refractive index layer is preferably 0.1 or more, and more preferably 0.2 or more.
Further, the refractive index of the phosphor part is preferably from 1.4 to 1.9, more preferably from 1.65 to 1.85.

厚み The thickness of the low refractive index layer is preferably 1 μm or less, which can reduce the influence on heat radiation. Further, from the viewpoint of suppressing the absorption by the reflective film, the thickness of the low refractive index layer is preferably 0.05 μm or more.

蛍光 The phosphor element of the present invention has an integral reflecting film covering the surface of the low refractive index layer. The fact that the reflection films are integral means that the reflection films are continuous with each other. However, it is not necessary that the reflection film covers the entire side surface and the entire opposing surface, and it is acceptable that the low refractive index layer is exposed without being covered by the reflection film on a part of the side surface and a part of the opposing surface. It shall be. However, also in this case, it is preferable that 90% or more of the total area of the side surfaces and 90% or more of the total area of the opposing surfaces are covered with the reflective film, and the entire side surfaces and the opposing surfaces are coated with the reflective film. More preferably, it is performed.

材質 The material of the reflection film is not particularly limited as long as it reflects the excitation light and the fluorescence that have passed through the phosphor layer. The reflection film does not need to totally reflect the excitation light, and may transmit some or all of the excitation light.

In a preferred embodiment, the reflection film is a metal film or a dielectric multilayer film, and may be a combination thereof.
When the reflective film is a metal film, the light can be reflected in a wide wavelength range, the incident angle dependence can be reduced, and the durability against temperature and weather resistance are excellent. On the other hand, when the reflective film is a dielectric multilayer film, since there is no absorption, light incident at a specific angle can be made 100% reflected light without loss, and can be composed of an oxide film. By increasing the adhesion to the bonding layer, peeling can be prevented.
In the case of a combination, a feature that complements both can be provided.

The reflectivity of the excitation light by the reflection film is set to 80% or more, preferably 95% or more.
The dielectric multilayer film is a film in which a high refractive material and a low refractive material are alternately laminated. Examples of the high refractive index include TiO ₂ , Ta ₂ O ₃ , Ta ₂ O ₃ , ZnO, Si ₃ N ₄ , and Nb ₂ O ₅ . Further, examples of the low refraction material include SiO ₂ , MgF ₂ , and CaF ₂ . The number of layers and the total thickness of the dielectric multilayer film are appropriately selected depending on the wavelength of the fluorescence to be reflected.

Further, the material of the metal film is preferably as follows.
(1) Single layer film of Al, Ag, Au, etc. (2) Multilayer film of Al, Ag, Au, etc. The thickness of the metal film is not particularly limited as long as it can reflect fluorescence, but is preferably 0.05 μm or more. 1 μm or more is more preferable. Further, in order to increase the adhesion between the metal film and the base material, it can be formed via a metal film of Ti, Cr, Ni, or the like.

において In the present invention, the area of the incident surface of the phosphor portion is larger than the area of the opposing surface. By combining the low-refractive-index layer and the reflective film with the form of the phosphor portion having a smaller area on the facing surface, the mechanism described above reduces the number of reflections of the excitation light and the fluorescence in the phosphor portion. As a result, it is possible to emit light from the incident surface, suppress heat generation due to absorption by the reflection film, and promote heat radiation of heat generated by propagation of light in the phosphor portion.

In the present invention, the area AI of the incident surface 2a is larger than the area AR of the opposing surface 2b, whereby the intensity of the fluorescent light emitted from the incident surface can be improved as described above. From such a viewpoint, the ratio of the area AI of the incident surface 2a / the area AR of the opposing surface 2b is preferably 1.2 or more, and more preferably 1.47 or more. In practice, the ratio of the area AI of the incident surface 2a / the area AR of the opposing surface 2b is preferably 27.2 or less, and more preferably 11 or less.

から From the same viewpoint, the inclination angle θ of the side surface with respect to the incident surface of the phosphor portion is preferably 50 ° or more and 85 ° or less, more preferably 60 ° or more and 80 ° or less. In this embodiment, the scattering material may be dispersed in the phosphor material, but particularly preferably, the scattering material is not dispersed in the phosphor material constituting the phosphor portion.

In addition, the thickness (the distance between the incident surface and the opposing surface) T (FIGS. 1 and 7) of the phosphor portion is preferably 290 μm or more, and more preferably 300 μm or more, in order to improve the efficiency of taking out the fluorescence on the emission side. , 450 μm or more. Further, the thickness may be 800 μm or more. However, the thickness is preferably 3.0 mm or less from the viewpoint of miniaturization, and 1.5 μm or less from the viewpoint of heat radiation.

In a preferred embodiment, a partially transparent film made of a transparent material that transmits excitation light and fluorescence can be provided on the incident surface of the phosphor section. The partially transmitting film is a film that reflects a part of the excitation light and transmits the rest. Specifically, the reflectance of the partially transmitting film with respect to the excitation light is 9% or more, and preferably 50% or less. Examples of the material of such a partial transmission film include a metal film for reflection and a dielectric multilayer film described above.

In the preferred embodiment, the incident surface side support substrate can be provided on the incident surface of the phosphor section, so that the heat radiation effect from the phosphor section can be further improved. Further, in another preferred embodiment, an opposing surface side support substrate can be provided on the main surface on the opposing surface side of the heat radiating substrate, whereby the heat radiating effect from the heat radiating substrate can be further improved.

Here, as a material of each support substrate, a material having a thermal conductivity (25 ° C.) of 200 W / mK or more is preferable, and a material of 300 W / m · K or more is particularly preferable. Although there is no particular upper limit on the thermal conductivity of this material, it can be set to 500 W / m · K or less from the viewpoint of practical availability.

Here, the material of each support substrate is preferably transparent or translucent to transmit light. However, the incident surface side support substrate can be provided with a window for irradiating the incident surface with the excitation light. In this case, the material of the incident surface side support substrate does not need to be transparent or translucent.

場合 When the material of each support substrate is transparent or translucent, the material of the support substrate is preferably alumina, aluminum nitride, silicon carbide, quartz, or glass.

When the material of each support substrate is not transparent or translucent, the material of the support substrate is alumina, aluminum nitride, silicon carbide, crystal, glass, copper, silver, gold, aluminum, or an alloy material containing the above metal Is preferred. The material of each support substrate may be the same or different.

In the phosphor element 31 shown in FIG. 5, a transparent or translucent support substrate 7 is formed on the incident surface 2a of the phosphor section 2. In this example, the support substrate 7 is wider than the phosphor part 2, and the low refractive index layer 3c and the reflection film 4c are extended thereon.

In a preferred embodiment, a heat dissipation substrate is provided in contact with the reflection film. The thermal conductivity (25 ° C.) of the material of the heat radiating substrate is preferably 200 W / mK or more. Although there is no particular upper limit on the thermal conductivity, it is preferably 500 W / m · K or less, more preferably 350 W / m · K or less, from the viewpoint of practical availability.
As a material of the heat dissipation substrate, gold, silver, copper, aluminum, or an alloy containing these metals is preferable.
Further, as a material of the heat dissipation substrate, ceramics such as silicon carbide and aluminum nitride are preferable. In the case of ceramics, the coefficient of thermal expansion with the phosphor can be adjusted to some extent. Therefore, it is advantageous in that reliability such as prevention of cracks and cracks due to thermal stress is improved.

When the heat radiation substrate is made of metal, it may be a metal plating film.
The type of the metal plating film may be an electrolytic plating film or an electroless plating film. The metal plating film is made of a metal having a thermal conductivity (25 ° C.) of 200 W / mK or more.

種類 As the kind of metal constituting the metal plating film of the phosphor part, gold, silver, copper, aluminum, or an alloy containing these metals is particularly preferable.

、 In the phosphor element 41 of FIGS. 6 and 7, the phosphor part 2, the low refractive index layer 3, and the reflection film 4 are the same as the phosphor element of FIG. However, in the present example, the phosphor portion 2, the low refractive index layer 3, and the reflection film 4 are fixed and integrated in the concave portion 8c of the heat dissipation substrate 8. However, 8a is a thin plate portion in contact with the

reflection film

4a, and 8b is a flange portion having a constant thickness, which is in contact with the reflection film 4b.

凹部 The concave portion of the heat dissipation board can be formed by machining or laser processing. Alternatively, the heat radiating substrate can be formed by a plating method or a thermal spraying method. When the heat radiating substrate is made of metal, the heat radiating substrate can be bonded to the phosphor element by a sintered bonding material. Further, when the heat radiating substrate is made of ceramics, the heat radiating substrate can be joined to the phosphor element by a sintered joining material.

The type of the metal plating film may be an electrolytic plating film or an electroless plating film. The metal plating film is made of a metal having a thermal conductivity (25 ° C.) of 200 W / mK or more.
As the kind of metal constituting the metal plating film of the phosphor part, gold, silver, copper, aluminum, or an alloy containing these metals is particularly preferable.

メッキ A base film for plating may be provided between the reflection film and the heat dissipation substrate. The base film may be Ni, Cr, Ti, or an alloy containing these metals.

The illumination device of the present invention includes a light source that oscillates a laser beam and the phosphor element.

(4) As the light source, a semiconductor laser made of a GaN material having high reliability for exciting the phosphor for illumination is suitable. Further, a light source such as a laser array arranged one-dimensionally can also be realized. It may be a super luminescence diode, a semiconductor optical amplifier (SOA) or an LED. Also, the excitation light from the light source can be made incident on the phosphor element through the optical fiber.

The method for generating white light from the semiconductor laser and the phosphor is not particularly limited, but the following method is conceivable.
A method of generating white light by generating yellow fluorescence with a blue laser and a phosphor A method of generating white light by generating red and green fluorescence with a blue laser and a phosphor A method of generating white light by generating green fluorescent light A method of generating white light by generating blue and yellow fluorescent light by a phosphor from a blue laser or an ultraviolet laser

The production method of the present invention
Joining the second main surface of the phosphor substrate having a first main surface and a second main surface to a handle substrate,
Forming a phosphor portion by processing the first main surface of the phosphor substrate to form an opposing surface and side surfaces,
A step of forming a reflective film so as to cover the opposing surface and the side surface; and a step of separating the phosphor section from the handle substrate. According to such a manufacturing method, a large number of specific phosphor elements can be simultaneously formed in one phosphor substrate, so that mass productivity can be improved.

In a preferred embodiment, a step of forming a low-refractive-index layer on the side surface and the opposing surface of the phosphor section is provided, and a reflective film is formed on the low-refractive-index layer. According to this manufacturing method, the phosphor element according to the present invention can be obtained with high productivity.

Hereinafter, the present production method will be exemplified with reference to the drawings.
As shown in FIGS. 8A and 8B, a bonding layer 52 is formed on a handle substrate 53 and is opposed to the phosphor plate 51. The surface 51b is joined.

Next, by processing the first main surface 51a of the phosphor plate 51 on the handle substrate 53, a phosphor portion having a required form can be formed. For example, in the example of FIG. 8B, the phosphor section 2 having a desired shape is formed on the bonding layer 52. Examples of such a processing method include dicing, slicing, micro grinder, laser processing, water jet, and micro blast.

Next, in a preferred embodiment, as shown in FIG. 9, a low refractive index layer 54 is formed on the phosphor section 2 and on the bonding layer 52. Next, as shown in FIG. 10, a reflection film 55 is formed on the low refractive index layer 54.

Next, by removing the handle substrate and the bonding layer, it is possible to obtain a substrate on which a large number of phosphor elements 1 shown in FIG. 1 are formed. Next, each phosphor element 1 can be cut into a predetermined size. Alternatively, a plurality of phosphor elements 1 can be used as a phosphor element array without being divided.

成膜 The method of forming the low refractive index layer and the reflective film is not particularly limited, but an evaporation method, a sputtering method, and a CVD method are preferable. In the case of a vapor deposition method, a film can be formed by adding ion assist.

According to the production method of the present invention, a reflective film (and a low-refractive-index layer if necessary) can be formed on the side surface and the opposing surface in one film-forming step. For example, when the side surface and the opposing surface are orthogonal as shown in FIG. 2B, it is not possible to simultaneously form the reflective film and the low refractive index layer on the side surface and the opposing surface by one film formation. When there are a plurality of film forming steps, there is a possibility that the refractive index may be distributed or the number of steps may increase the cost, but this manufacturing method can solve the problem.

Furthermore, in a preferred embodiment, a scattering material is dispersed in the phosphor portion, and the thickness of the phosphor portion (the distance between the incident surface and the opposing surface) is 290 μm or more and 1.0 mm or less, and the incident surface Is 25 ° or more and 49 ° or less. When the scattering material is dispersed in the phosphor portion and the phosphor portion is relatively thin, it has been found that high luminous efficiency and low color unevenness can be realized even when θ is small.

In the present embodiment, the thickness T (the distance between the incident surface and the facing surface) of the phosphor portion is more preferably 300 μm or more, and further preferably 650 μm or less. Further, the inclination angle θ of the side surface with respect to the incident surface is more preferably 30 ° or more, and further preferably 46 ° or less.

When a scattering material is dispersed in the phosphor portion, the scattering material preferably does not absorb the excitation light and the fluorescence and has a large difference in refractive index from the phosphor. Al ₂ O ₃ , SiO ₂ , TiO ₂ and ZrO ₂ can be exemplified.

In a preferred embodiment, a scattering material is not contained in the phosphor part, the interval between the incident surface and the opposing surface is 290 μm or more and 1.0 mm or less, and the inclination angle of the side surface with respect to the incident surface is 25 ° or more and 70 ° or less. When the scattering material is dispersed in the phosphor part and the phosphor part is relatively thin, not only when θ is 50 ° or more but also when θ is small, high luminous efficiency and low color unevenness are obtained. Has been found to be possible.

In the present embodiment, the inclination angle of the side surface with respect to the incident surface is preferably 25 ° or more and 42 ° or less, and more preferably 49 ° or more and 65 ° or less. More preferably, the inclination angle of the side surface with respect to the incident surface is 40 ° or less.

Similarly, even when the phosphor portion is relatively thin, if the phosphor portion does not contain a scattering material, the behavior is different from the case where the phosphor portion and the scattering material are dispersed. .

FIG. 11 is a cross-sectional view schematically showing a phosphor element 61 according to the present embodiment.
In the phosphor element 61 shown in FIG. 11, the phosphor part 62 includes an incident surface 62a, an exit surface 62b, and four side surfaces 62c. In the cross section of the phosphor portion, the phosphor portion is substantially trapezoidal, and the angle θ of the side surface 62c with respect to the incident surface 62a is an acute angle smaller than 90 °, preferably 49 to 25 °. The area AI of the incident surface 2a is larger than the area AR of the opposing surface 2b. A large number of scattering materials 63 are dispersed in the phosphor part 62.

A low-refractive-index layer 3b is provided on a side surface 62c of the phosphor section 62, and a low-refractive-index layer 3a is provided on the opposing surface 62b. The low-refractive-

index layers

3a and 3b form an integrated low-refractive-index layer. The refractive index layer 3 is formed. In this example, the low refractive index layer 3 covers the entire side surface 62c and the opposing surface 62b of the phosphor portion 62. Further, in this example, the reflection film 4a is provided on the low-refractive-index layer 3a, and the reflection film 4b is provided on the low-refractive-index layer 3b. The

reflection films

4a and 4b form an integral reflection film 4. Have been. In this example, the reflection film 4 covers the low refractive index layer 3 over the entire surface.

As shown in FIG. 11, in the phosphor element 61 of the present invention, excitation light incident as shown by an arrow A impinges on many phosphor particles 5 dispersed in the phosphor part 62. Then, fluorescence is emitted from each phosphor particle 5 as indicated by arrows K1, K3, and K5. At this time, the fluorescent particles tend to emit fluorescence uniformly in all directions. In addition, the fluorescence emitted from the phosphor particles is further scattered in all directions by the scattering material, and the fluorescence tends to be more uniform.

Here, the fluorescent light emitted from the phosphor particles in the direction of the incident surface 62a is emitted from the incident surface 62a as it is. Further, the fluorescent light emitted from the phosphor particles toward the facing surface 62b as shown by an arrow K3 is refracted by the low refractive index layer 3a, reflected by the reflective film 4a, refracted by the low refractive index layer 3a again, and The light exits from the incident surface 2a as shown in FIG. Fluorescent light emitted obliquely as indicated by arrows K1 and K5 is totally reflected by the low refractive index layers 3a and 3b and exits from the incident surface 2a as indicated by arrows K2 and K6. At this time, if the area AI of the incident surface of the phosphor portion 62 is larger than the area AR of the opposing surface and the side surface 62c is inclined, the directions of the reflected lights K2 and K6 are changed by the inclination angle θ. It inclines toward the inclined surface 2a. As a result, the number of reflections until the excitation light exits from the incident surface 62a can be reduced. Further, due to the presence of the low refractive index layers 3a and 3b, light absorption due to reflection on the reflection film 4 and a rise in temperature of the reflection film can be suppressed.

In the phosphor element 61A shown in FIG. 12, the transparent or translucent support substrate 7 is formed on the incident surface 62a of the phosphor section 62.

において In the phosphor element 61B of FIG. 13, the phosphor part 62, the low refractive index layer 3, and the reflection film 4 are the same as the phosphor element 61 of FIG. However, in the present embodiment, the phosphor portion 62, the low refractive index layer 3, and the reflection film 4 are fixed and integrated in the concave portion 8c of the heat dissipation substrate 8. However, 8a is a thin plate portion in contact with the

reflection film

(Example 1)
The phosphor element 41 shown in FIGS. 6 and 7 was manufactured by the manufacturing method described with reference to FIGS.
Specifically, a phosphor plate 51 made of YAG (yttrium aluminum garnet) polycrystal having a thickness of 1 mm and a diameter of 4 inches doped with Ce and doped with a ceramic scattering material was prepared. A sapphire wafer having a thickness of 0.3 mm and a diameter of 4 inches was prepared as the handling substrate 53. The phosphor plate 51 was bonded to the handling substrate 53 using the thermoplastic resin 52 at 100 ° C., and then returned to room temperature and integrated (FIG. 8A).

Next, setback processing by dicing was performed using a blade having a width of 100 μm and # 800. Next, the phosphor plate was rotated 90 degrees, and setback processing was similarly performed by dicing to form the phosphor portion 2 (FIG. 8B). The width of the incident surface was 2 mm, the thickness was 1 mm, and the inclination θ of the side surface with respect to the incident surface was 63.5 °. The area AI of the incident surface is 4 mm ² , and the area of the facing surface is 1 mm ² . The side surface and the opposing surface of each phosphor part 2 were processed surfaces by dicing, and the arithmetic average roughness Ra of the side surface and the opposing surface was estimated to be 10 μm.

Next, a low-refractive-index layer 54 of Al ₂ O _{3 was formed} to a thickness of 0.5 μm on the facing surface 2b and the side surface 2c of the phosphor section by sputtering (see FIG. 9). Further, a reflective film 55 made of an Al alloy film was formed on the low refractive index layer 54 with a thickness of 0.5 μm (FIG. 10). After the film formation, the substrate was heated to 100 ° C. with a hot plate, the phosphor element 1 as shown in FIG. 1 was separated from the handling substrate 53, and the adhesive was washed with an organic solvent.
Next, a heat dissipation substrate 8 made of oxygen-free copper having a width of 20 mm × a length of 20 mm and a thickness of 2 mm was prepared. A groove was formed in the center of the heat dissipation substrate 8, and the phosphor element 1 was buried, thereby obtaining a phosphor element 41 shown in FIGS.

１０ 10 GaN blue lasers with an output of 3 W were arrayed to obtain a light source with an output of 30 W. The phosphor element was irradiated with laser light from this light source, and the illumination light was evaluated. Table 1 shows the evaluation results of the devices of each example.

(White light output)
The white light output (average output) represents the time average of the total luminous flux. The total luminous flux measurement is performed by using an integrating sphere (spherical luminometer) to turn on the light source to be measured and the standard light source for which the total luminous flux is priced at the same position, and to compare the light sources. Specifically, the measurement was performed using the method specified in JISC7801.

(Distribution in color unevenness plane)
The output light was evaluated by a chromaticity diagram using a luminance distribution measuring device. Then, in the chromaticity diagram, when the median value is within the range of x: 447 ± 0.005 and y: 0.3553 ± 0.005, “no color unevenness” is set. There is unevenness. "

(Comparative Example 1)
A phosphor element 21 having a cross section shown in FIG. The fabrication method was the same as in Example 1. However, the low-refractive-index layer 23 made of Al ₂ O ₃ was not formed on the opposing surface of the phosphor portion, but was formed only on the side surface by sputtering multiple times. Then, a reflective film 24 made of an Al alloy film was formed with a thickness of 0.5 μm on the low refractive index layer and the opposing surface. The obtained device was fixed to the heat dissipation board 8 in the same manner as in Example 1.

照明 The obtained phosphor element was evaluated for illumination light in the same manner as in Example 1. Table 2 shows the evaluation results of the devices of each example.

場合 In the case of the phosphor element of Example 1, the white light output was relatively high and no color unevenness was observed. In the phosphor element of Comparative Example 1, the white light output was low, and color unevenness was observed.

(Comparative Example 2)
The phosphor element 26 shown in FIG. 4 was manufactured by the manufacturing method described with reference to FIGS.
Specifically, a phosphor plate 51 made of YAG (yttrium aluminum garnet) polycrystal having a thickness of 1 mm and a diameter of 4 inches doped with Ce and doped with a ceramic scattering material was prepared. A sapphire wafer having a thickness of 0.3 mm and a diameter of 4 inches was prepared as the handling substrate 53. The phosphor plate 51 was bonded to the handling substrate 53 using the thermoplastic resin 52 at 100 ° C., and then returned to room temperature and integrated (FIG. 8A).

Next, setback processing by dicing was performed using a blade having a width of 100 μm and # 800. Next, the phosphor plate was rotated 90 degrees, and setback processing was similarly performed by dicing to form the phosphor portion 2 (FIG. 8B). The width of the incident surface was 2 mm, the thickness was 1 mm, and the inclination θ of the side surface with respect to the incident surface was 63.5 °. The area AI of the incident surface is 4 mm ² . The side surface and the opposing surface of each phosphor part 2 were processed surfaces by dicing, and the arithmetic average roughness Ra of the side surface and the opposing surface was estimated to be 10 μm.

Next, the low refractive index layer 27 made of Al ₂ O ₃ was formed by sputtering only on the opposing surface without being provided on the side surface of the phosphor portion. Then, a reflective film 4 made of an Al alloy film was formed with a thickness of 0.5 μm on the low refractive index layer and the side surfaces. After the film formation, the substrate was heated to 100 ° C. with a hot plate, the phosphor element 26 as shown in FIG. 4 was separated from the handling substrate 53, and the adhesive was washed with an organic solvent.
Next, a heat dissipation substrate 8 made of oxygen-free copper having a width of 20 mm × a length of 20 mm and a thickness of 2 mm was prepared. A groove was formed in the center of the heat radiating substrate 8, and the phosphor element was fixed in the concave portion of the heat radiating substrate 8, as shown in FIGS.

１０ 10 GaN blue lasers with an output of 3 W were arrayed to obtain a light source with an output of 30 W. The phosphor element was irradiated with laser light from this light source, and the illumination light was evaluated. Table 3 shows the evaluation results of the devices of each example.

場合 In the case of the phosphor element of Example 1, the white light output was relatively high and no color unevenness was observed. In the phosphor element of Comparative Example 2, the white light output was low, and color unevenness was observed.

(Examples 2 to 6)
The phosphor element 61B shown in FIG. 13 was manufactured by the manufacturing method described with reference to FIGS.
Specifically, a phosphor plate 51 made of YAG (yttrium aluminum garnet) polycrystal having a thickness of 1 mm and a diameter of 4 inches doped with Ce and doped with a ceramic scattering material was prepared. A sapphire wafer having a thickness of 0.3 mm and a diameter of 4 inches was prepared as the handling substrate 53. The phosphor plate 51 was bonded to the handling substrate 53 using the thermoplastic resin 52 at 100 ° C., and then returned to room temperature and integrated (FIG. 8A).

Next, setback processing by dicing was performed using a blade having a width of 100 μm and # 800. Next, the phosphor plate was rotated by 90 degrees and setback processing was similarly performed by dicing to form the phosphor portion 62 (FIG. 8B). The width of the incident surface was 2 mm, the thickness was 0.29 mm, and the inclination θ of the side surface with respect to the incident surface was 25 °, 45 °, 49 °, 50 °, and 63.5 °. The area AI of the incident surface is 4 mm ² . The side surface and the opposing surface of each phosphor portion 62 are surfaces processed by dicing, and the arithmetic average roughness Ra of the side surface and the opposing surface was estimated to be 10 μm.

Next, a low-refractive-index layer 54 of Al ₂ O _{3 was formed} to a thickness of 0.5 μm on the facing surface 62b and the side surface 62c of the phosphor section by sputtering (see FIG. 9). Further, a reflective film 55 made of an Al alloy film was formed on the low refractive index layer 54 with a thickness of 0.5 μm (FIG. 10). After the film formation, the substrate was heated to 100 ° C. with a hot plate, the phosphor element 61 as shown in FIG. 11 was separated from the handling substrate 53, and the adhesive was washed with an organic solvent.

Next, a heat dissipation board 8 made of oxygen-free copper having a width of 20 mm, a length of 20 mm, and a thickness of 2 mm was prepared. A groove was formed in the center of the heat dissipation substrate 8, and the phosphor element 61 was buried to obtain a phosphor element 61B shown in FIG.

１０ 10 GaN blue lasers with an output of 3 W were arrayed to obtain a light source with an output of 30 W. The phosphor element was irradiated with laser light from the light source (spot size diameter: 1.9 mm), and the illumination light was evaluated. Table 4 shows the evaluation results of the devices of each example.

As can be seen from the results in Table 4, it was found that the output of white light could be increased and color unevenness could be prevented. In particular, when the scattering material is dispersed in the phosphor part, even when the inclination angle θ of the side surface with respect to the incident surface is reduced to 49 ° to 25 °, the unexpected result that the white light output is rather improved. was gotten. Further, when the inclination angle is smaller than 20 °, color unevenness occurs due to the effect that the excitation light is directly reflected from the facing surface and output in the thin region of the outer peripheral portion. Even when the thickness of the phosphor is 400 μm, When the inclination angle θ was reduced to 49 ° to 25 °, the white light output was improved.

(Comparative Example 3)
A phosphor element 21 having a cross section shown in FIG. 3B was produced in the same manner as in Comparative Example 1. The manufacturing method was the same as in Comparative Example 1. However, the ceramic scattering material was dispersed in the phosphor portion, and the inclination θ of the side surface with respect to the incident surface was 45 °. The obtained phosphor element was fixed to the heat dissipation substrate 8 in the same manner as in Example 1.

(Comparative Example 4)
A phosphor element having a cross section shown in FIG. 4 was produced in the same manner as in Comparative Example 2. The manufacturing method was the same as Comparative Example 2. However, the ceramic scattering material was dispersed in the phosphor portion, and the inclination θ of the side surface with respect to the incident surface was 45 °. The obtained phosphor element was fixed to the heat dissipation substrate 8 in the same manner as in Example 1.

照明 Each of the phosphor elements of Example 3, Comparative Example 3, and Comparative Example 4 was evaluated for illumination light in the same manner as in Examples 2 to 6. Table 5 shows the evaluation results of the devices of each example.

場合 In the case of the phosphor element of Example 3, the white light output was relatively high and no color unevenness was observed. In the phosphor elements of Comparative Examples 3 and 4, the white light output was relatively low, and color unevenness was observed.

Hereinafter, in Example 1 and Example 2, the inclination angle θ of the side surface with respect to the incident surface was changed as shown in FIG. As described above, the first embodiment is a phosphor element having a configuration as shown in FIGS. 1, 6, and 7, in which the scattering material is not dispersed in the phosphor portion. On the other hand, Example 2 is a phosphor element having a form as shown in FIGS. 11 and 13, in which a scattering material is dispersed in the phosphor portion. The inclination angle θ was changed to 85 °, 63.5 °, 50 °, 49 °, 45 °, 39 °, 31 °, and 25 °. FIG. 14 shows the power efficiency of the obtained white light.

As a result, when the scattering material is dispersed in the phosphor portion, the power efficiency (fluorescent power / excitation light power) may be particularly high particularly when the inclination angle θ is 25 ° or more and 49 ° or less. all right.

On the other hand, it was found that when the scattering material was not contained in the phosphor portion, the power efficiency was particularly high when the inclination angle was in the range of 25 ° or more and 70 ° or less. Particularly preferably, the power efficiency is increased when the inclination angle θ of the side surface with respect to the incident surface is 25 ° or more, 42 ° or less, or 49 ° or more and 65 ° or less.

Claims

An incident surface of the excitation light, a phosphor portion having an opposing surface and a side surface facing the incident surface, wherein at least a part of the excitation light incident on the incident surface is converted into fluorescent light, and the fluorescent light is converted into the fluorescent light. A phosphor portion emitted from the incident surface,
An integrated low-refractive-index layer having a refractive index lower than the refractive index of the phosphor section, on the side surface and the opposing surface of the phosphor section; and an integral low-refractive-index layer covering the surface of the low-refractive-index layer. A phosphor element, comprising a reflective film, wherein the area of the incident surface of the phosphor section is larger than the area of the facing surface.
The phosphor element according to claim 1, wherein an inclination angle of the side surface with respect to the incident surface is not less than 50 ° and not more than 85 °.
A scattering material is dispersed in the phosphor part, a distance between the incident surface and the opposing surface is 290 μm or more and 1.0 mm or less, and an inclination angle of the side surface with respect to the incident surface is 25 ° or more and 49 ° or more. The phosphor element according to claim 1, wherein:
4. The phosphor element according to claim 3, wherein the scattering material is a ceramic scattering material.
A scattering material is not contained in the phosphor part, a distance between the incident surface and the facing surface is 290 μm or more and 1.0 mm or less, and an inclination angle of the side surface with respect to the incident surface is 25 ° or more and 70 ° or more. The phosphor element according to claim 1, wherein the angle is equal to or less than 0 °.
The phosphor element according to claim 5, wherein an inclination angle of the side surface with respect to the incident surface is 25 ° or more, 42 ° or less, or 49 ° or more and 65 ° or less.
(7) The phosphor element according to any one of (1) to (6), wherein a support substrate made of a transmissive material that transmits the excitation light and the fluorescence is provided on the incident surface.
(8) The phosphor element according to any one of (1) to (7), further comprising a heat dissipation substrate in contact with the reflection film.
The phosphor element according to claim 8, wherein the heat dissipation board is made of a material having a thermal conductivity of 200 W / mK or more.
10. The phosphor element according to claim 9, wherein the heat radiating substrate is made of a metal having a thermal conductivity of 200 W / mK or more and 500 W / mK or less, or a ceramic.
The phosphor element according to claim 10, wherein the metal is gold, silver, copper, aluminum, or an alloy containing these metals.
11. The phosphor element according to claim 10, wherein the ceramic is silicon carbide or aluminum nitride.
照明 An illuminating device comprising: a light source that oscillates a laser beam; and the phosphor element according to any one of claims 1 to 12.
An incident surface of the excitation light, a phosphor portion having an opposing surface and a side surface facing the incident surface, wherein at least a part of the excitation light incident on the incident surface is converted into fluorescent light, and the fluorescent light is converted into the fluorescent light. A phosphor element that emits light from an incident surface, and an integrated reflective film that covers the phosphor part, wherein a phosphor element in which the area of the incident surface of the phosphor part is larger than the area of the facing surface is manufactured. A way to
Joining the second main surface of the phosphor substrate having a first main surface and a second main surface to a handle substrate,
Forming the phosphor portion by processing the first main surface of the phosphor substrate to form the opposing surface and the side surface;
A method of manufacturing a phosphor element, comprising: a step of forming the reflection film so as to cover the facing surface and the side surface; and a step of separating the phosphor part from the handle substrate.
A step of forming the low-refractive-index layer on the side surface and the opposing surface of the phosphor section, wherein the reflective film is formed on the low-refractive-index layer. Item 15. The method according to Item 14.
16. The method according to claim 14, wherein an inclination angle of the side surface with respect to the incident surface is not less than 50 ° and not more than 85 °.
A scattering material is dispersed in the phosphor part, a distance between the incident surface and the opposing surface is 290 μm or more and 1.0 mm or less, and an inclination angle of the side surface with respect to the incident surface is 25 ° or more and 49 ° or more. The method according to claim 14, wherein:
The method of claim 17, wherein the scattering material is a ceramic scattering material.
A scattering material is not contained in the phosphor part, a distance between the incident surface and the facing surface is 290 μm or more and 1.0 mm or less, and an inclination angle of the side surface with respect to the incident surface is 25 ° or more and 70 ° or more. The method according to claim 14 or 15, characterized in that it is less than or equal to °.
20. The method according to claim 19, wherein an inclination angle of the side surface with respect to the incident surface is 25 ° or more and 42 ° or less or 49 ° or more and 65 ° or less.
The method according to any one of claims 14 to 20, wherein a support substrate made of a transparent material that transmits the excitation light and the fluorescence is provided on the incident surface.
The method according to any one of claims 14 to 21, further comprising: providing a heat dissipation substrate in contact with the reflection film.
23. The method according to claim 22, wherein the heat radiating substrate is made of a material having a thermal conductivity of 200 W / mK or more.
24. The method according to claim 23, wherein the heat radiating substrate is made of a metal or a ceramic having a thermal conductivity of 200 W / mK or more and 500 W / mK or less.
25. The method according to claim 24, wherein the ceramic is silicon carbide or aluminum nitride.
The method according to claim 24, wherein the metal is gold, silver, copper, aluminum, or an alloy containing these metals.