JP2022057984A - Light-emitting member, manufacturing method therefor, optical member, and light-emitting device - Google Patents

Abstract

To reduce unevenness in color and/or brightness of light exiting from a light exit surface.SOLUTION: A light-emitting member comprises a light-emitting unit with a first surface configured to emit light, and a film formed on the first surface. The film has a refractive index that differs from that of the light-emitting unit by 0.3 or more, contains a particular substance, and has a thickness in a range of 10 to 70 nm, inclusive.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a light emitting member, a method for manufacturing the same, an optical member, and a light emitting device.

As disclosed in Patent Document 1, an optical member on which an optical thin film is formed is known. As the optical thin film, for example, a metal oxide film is used. By using a metal oxide film, an antireflection film, a reflection film, a filter film, a retardation film, a surface protection film and the like can be realized. In such an optical member, various optical characteristics are required depending on the usage state.

Japanese Unexamined Patent Publication No. 2013-140201

An object of the present disclosure is to reduce color unevenness and / or luminance unevenness of light emitted from a light emitting surface.

The light emitting member according to the embodiment of the present disclosure has a first surface, has a light emitting portion from which light is emitted, and a film formed on the first surface, and the film is the film. The difference in refractive index from the light emitting portion is 0.3 or more, the substance in the form of particles is contained, and the film thickness is 10 nm or more and 70 nm or less.

Further, the light emitting member according to the embodiment of the present disclosure has a first surface, has a light emitting portion from which light is emitted, and a film formed on the first surface, and the film is the said film. The difference in refractive index between the film and the light emitting portion is 0.3 or more, the particle-like substance is contained, and the particle-like substance occupies the area of the region in the region where the film is formed. The ratio is 30% or more and 80% or less.

Further, the optical member according to the embodiment of the present disclosure is a translucent member arranged on the second surface side opposite to the first surface of the light emitting portion with the light emitting member according to the embodiment of the present disclosure. It has a plate-shaped member and.

Further, the light emitting device according to the embodiment of the present disclosure includes a base having a bottom surface and a frame surrounding the bottom surface, a light emitting element arranged on the bottom surface, and a light emitting member according to the embodiment of the present disclosure. Alternatively, it has an optical member according to an embodiment of the present disclosure, and seals a space in which the light emitting element is arranged.

Further, the method for manufacturing a light emitting member according to an embodiment of the present disclosure includes a step of preparing a light emitting portion having a first surface and emitting light, a step of forming a film on the first surface, and the film. In the step of forming the film, a film containing a substance having a refractive index difference of 0.3 or more from the light emitting portion and having a film thickness of 10 nm or more and 70 nm or less is formed. In the step of heating the membrane, the substance is atomized.

Further, the method for manufacturing a light emitting member according to an embodiment of the present disclosure includes a step of preparing a light emitting portion having a first surface and emitting light, a step of forming a film on the first surface, and the film. In the step of forming the film, a film containing a substance having a refractive index difference of 0.3 or more from the light emitting portion is formed, and in the step of heating the film, the above-mentioned In the region where the substance is atomized and the film is formed, the ratio of the particulate substance to the area of the region is 30% or more and 80% or less.

According to one embodiment of the present disclosure, it is possible to reduce color unevenness and / or luminance unevenness of light emitted from a light emitting surface.

It is a perspective view which illustrates the light emitting member which concerns on 1st Embodiment. FIG. 5 is a cross-sectional view taken along the line II-II of FIG. 1 illustrating a light emitting member according to the first embodiment. It is a figure (the 1) which illustrates the manufacturing method of the light emitting member which concerns on 1st Embodiment. It is a figure (the 2) which illustrates the manufacturing method of the light emitting member which concerns on 1st Embodiment. It is an SEM photograph of the film of niobium oxide before heating. It is an SEM photograph of the film of niobium oxide after heating at 800 degreeC for 1h under atmospheric pressure. It is an SEM photograph of the film of niobium oxide after heating at 850 ° C. for 1 hour under atmospheric pressure. It is an SEM photograph of the film of niobium oxide after heating at 900 degreeC for 1h under atmospheric pressure. It is an SEM photograph of the film of niobium oxide after heating at 950 ° C. for 1 hour under atmospheric pressure. It is an SEM photograph of the film of niobium oxide after heating at 1000 degreeC for 1h under atmospheric pressure. 6 is an SEM photograph of a niobium oxide film having a film thickness of 5 [nm] after heating at 950 ° C. for 1 hour under atmospheric pressure. 6 is an SEM photograph of a niobium oxide film having a film thickness of 10 [nm] after heating at 950 ° C. for 1 hour under atmospheric pressure. 6 is an SEM photograph of a niobium oxide film having a film thickness of 30 [nm] after heating at 950 ° C. for 1 hour under atmospheric pressure. 6 is an SEM photograph of a niobium oxide film having a film thickness of 50 [nm] after heating at 950 ° C. for 1 hour under atmospheric pressure. 6 is an SEM photograph of a niobium oxide film having a film thickness of 70 [nm] after heating at 950 ° C. for 1 hour under atmospheric pressure. 6 is an SEM photograph of a niobium oxide film having a film thickness of 100 [nm] after heating at 950 ° C. for 1 hour under atmospheric pressure. It is a figure which illustrates the change of the linear transmittance before and after heating of the film of the niobium oxide of the film thickness 10 [nm]. It is a figure which illustrates the change of the linear transmittance before and after heating of the film of the niobium oxide of the film thickness 30 [nm]. It is a figure which illustrates the change of the linear transmittance before and after heating of the film of the niobium oxide of the film thickness 50 [nm]. It is a figure which illustrates the change of the linear transmittance before and after heating of the film of the niobium oxide of the film thickness 70 [nm]. It is a figure which illustrates the relationship between the output of a laser beam input to a light emitting member, and the luminous efficiency. It is a perspective view which illustrates the optical member which concerns on 2nd Embodiment. It is sectional drawing in XXIII-XXIII line of FIG. 22 exemplifying the optical member which concerns on 2nd Embodiment. It is a perspective view which illustrates the light emitting device which concerns on 3rd Embodiment. It is sectional drawing in the XXV-XXV line of FIG. 24 which illustrates the light emitting apparatus which concerns on 3rd Embodiment. It is a perspective view of the state which further removed the optical member from the light emitting device which concerns on 3rd Embodiment. It is a top view of the state which further removed the optical member from the light emitting device which concerns on 3rd Embodiment.

Hereinafter, embodiments for carrying out the invention will be described with reference to the drawings. In the following description, terms indicating a specific direction or position (for example, "upper", "lower", and other terms including those terms) are used as necessary, but the use of these terms is used. The purpose is to facilitate understanding of the invention with reference to the drawings, and the meaning of these terms does not limit the technical scope of the present invention. Further, the parts having the same reference numerals appearing in a plurality of drawings indicate the same or equivalent parts or members.

Further, in the present disclosure, a polygon such as a triangle or a quadrangle shall be referred to as a polygon including a shape in which the corners of the polygon are rounded, chamfered, chamfered, rounded, or the like. .. Further, not only the corner (edge of the side) but also the shape in which the middle part of the side is processed is also referred to as a polygon. That is, a shape that has been partially processed while leaving the polygon as a base is included in the interpretation of the "polygon" described in the present disclosure.

The same applies not only to polygons but also to words expressing specific shapes such as trapezoids, circles, and irregularities. The same applies when dealing with each side forming the shape. In other words, even if a corner or an intermediate part is processed on a certain side, the interpretation of "side" includes the processed part. In addition, when distinguishing a "polygon" or "side" without partial processing from a processed shape, "strict" shall be added and described as, for example, "strict quadrangle". ..

Furthermore, the embodiments shown below exemplify light emitting members and the like for embodying the technical idea of the present invention, and do not limit the present invention to the following. In addition, the dimensions, materials, shapes, relative arrangements, etc. of the components described below are not intended to limit the scope of the present invention to the specific description, but are exemplified. It was intended. Further, the contents described in one embodiment can be applied to other embodiments and modifications. In addition, the size and positional relationship of the members shown in the drawings may be exaggerated in order to clarify the explanation. Further, in order to avoid the drawing from becoming excessively complicated, a schematic view in which some elements are not shown may be used, or an end view showing only the cut surface may be used as the cross-sectional view.

<First Embodiment>
FIG. 1 is a perspective view illustrating the light emitting member according to the first embodiment. FIG. 2 is a cross-sectional view taken along the line II-II of FIG. 1, illustrating a light emitting member according to the first embodiment.

As shown in FIGS. 1 and 2, the light emitting member 10 has a composite member 13 and a film 15.

Each component of the light emitting member 10 will be described.

(Composite member 13)
The composite member 13 has a light emitting unit 11 and a light reflecting unit 12. However, the light reflecting unit 12 is not an essential component and is provided as needed.

The light emitting unit 11 has an upper surface 11a, a lower surface 11b opposite to the upper surface 11a, and a side surface 11c intersecting the upper surface 11a and the lower surface 11b. The upper surface of the light emitting unit 11 may be referred to as a first surface, and the lower surface may be referred to as a second surface. The side surface 11c connects the outer edge of the upper surface 11a and the outer edge of the lower surface 11b. The light emitting unit 11 is, for example, a rectangular parallelepiped or a cube. In this case, the upper surface 11a and the lower surface 11b of the light emitting unit 11 are both rectangular, and the light emitting unit 11 has four rectangular side surfaces 11c. The rectangle referred to here is a rectangle or a square.

However, the light emitting unit 11 is not limited to a rectangular parallelepiped or a cube. That is, the planar shape of the light emitting unit 11 is not limited to a rectangle, and can be any shape such as a circle, an ellipse, or a polygon. The view of the object from the normal direction of the upper surface 11a of the light emitting unit 11 may be referred to as a plan view, and the shape of the object viewed from the normal direction of the upper surface 11a of the light emitting unit 11 may be referred to as a planar shape. There is.

The light emitting unit 11 can emit light incident from the lower surface 11b from the upper surface 11a, for example. That is, the upper surface 11a is a light emitting surface from which light is emitted. The light emitting unit 11 may have a translucency that allows light to pass through. In the present application, the translucency means that the transmittance with respect to light is 80% or more.

Since the light emitting unit 11 is irradiated with light, it is preferable that the base material of the light emitting unit 11 is formed by using an inorganic material that is not easily decomposed by light irradiation as the main material. The main material is, for example, ceramics. Examples of the ceramics used as the main material include aluminum oxide, aluminum nitride, silicon oxide, yttrium oxide, zirconium oxide, and magnesium oxide. As the main material of the ceramics, it is preferable to select a material having a melting point of 1300 ° C. to 2500 ° C. so that the light emitting portion 11 is not deformed or discolored due to heat. The light emitting unit 11 is, for example, a sintered body formed of ceramics as a main material.

The light emitting unit 11 may be a wavelength conversion unit having a phosphor. When the light emitting unit 11 is a wavelength conversion unit, the light emitting unit 11 can, for example, convert the light incident from the lower surface 11b into light having a different wavelength, and emit the converted light from the upper surface 11a. The light emitting unit 11 may emit a part of the incident light. The light emitting unit 11 may convert all the incident light into light having a different wavelength. In this case, the light incident on the light emitting unit 11 is not emitted from the light emitting unit 11.

When the light emitting unit 11 is a wavelength conversion unit, the light emitting unit 11 can be formed by sintering, for example, a phosphor and a translucent material such as aluminum oxide. The content of the phosphor can be 0.05% by volume to 50% by volume with respect to the total volume of the ceramics. Further, for example, ceramics obtained by sintering a powder of a fluorescent substance, which is substantially composed of only the fluorescent substance, may be used. Further, the light emitting unit 11 may be formed of a single crystal of a phosphor.

Examples of the fluorescent substance include yttrium aluminum garnet (YAG) activated with cerium, lutetium aluminum garnet (LAG) activated with cerium, and silicate activated with europium ((Sr, Ba) ₂ SiO ₄ ). Examples thereof include α-sialon fluorescent material and β-sialon fluorescent material. Among them, garnet-based fluorescent materials such as YAG fluorescent material and LAG fluorescent material have good heat resistance.

For example, when the light emitting unit 11 has a YAG phosphor, when blue excitation light is incident from the lower surface 11b, white light can be emitted from the upper surface 11a by combining the blue excitation light and fluorescence.

The light reflecting portion 12 is, for example, a frame-shaped member having a rectangular opening. The light reflecting portion 12 has an upper surface 12a, a lower surface 12b opposite to the upper surface 12a, an inner side surface 12c connecting the inner edge of the upper surface 12a and the inner edge of the lower surface 12b, and an outer edge of the upper surface 12a and an outer edge of the lower surface 12b. It has an outer surface 12d to be connected. The outer and inner edges of the upper surface 12a and the outer and inner edges of the lower surface 12b are, for example, rectangular. In this case, the light reflecting portion 12 has an inner side surface 12c of four rectangles and an outer surface 12d of the four rectangles. However, the outer and inner edges of the upper surface 12a and the outer and inner edges of the lower surface 12b are not limited to rectangles, and can be any shape such as a circle, an ellipse, and a polygon.

The light reflecting portion 12 is, for example, a sintered body formed of ceramics as a main material. Examples of the ceramics used as the main material include aluminum oxide, aluminum nitride, silicon oxide, yttrium oxide, zirconium oxide, magnesium oxide and the like. Among these, aluminum oxide is preferable in that it has a high reflectance. The light reflecting unit 12 does not have to use ceramics as the main material. The light reflecting portion 12 may be formed by using, for example, a metal, a composite of ceramics and a metal, or the like.

In the composite member 13, the inner side surface 12c of the light reflecting portion 12 is connected to the side surface 11c of the light emitting portion 11. The composite member 13 has a flat plate shape, for example, a rectangular parallelepiped.

The upper surface 11a of the light emitting portion 11 and the upper surface 12a of the light reflecting portion 12 may form, for example, one continuous plane. Further, the lower surface 11b of the light emitting portion 11 and the lower surface 12b of the light reflecting portion 12 may form, for example, one continuous plane. The composite member 13 may have a shape in which the upper surface 11a and / or the lower surface 11b of the light emitting portion 11 protrudes from the upper surface 12a and / or the lower surface 12b of the light reflecting portion 12. In this case, a part of the side surface 11c of the light emitting unit 11 is connected to the inner surface surface 12c of the light reflecting unit 12.

The light emitting portion 11 and the light reflecting portion 12 may be formed by joining separate bodies or may be integrally formed. The light emitting portion 11 and the light reflecting portion 12 may be integrally formed by, for example, a sintered body. It is also possible to adjust the porosity in the light emitting unit 11 and the light reflecting unit 12. The porosity can be adjusted by the sintering conditions (sintering temperature, sintering time, heating rate), particle size of the material, concentration of the sintering aid, and the like.

For example, when the light emitting unit 11 and the light reflecting unit 12 are formed using the same ceramics as the main material, the porosity of the light reflecting unit 12 is made larger than the porosity of the light emitting unit 11. That is, the composite member 13 is formed so that the light reflecting portion 12 includes more voids than the light emitting portion 11. In this case, it is preferable to adjust the sintering conditions so that the porosity of the light reflecting portion 12 is about 10%. As a result, a reflection region due to air is formed at the boundary between the side surface 11c of the light emitting unit 11 and the inner surface 12c of the light reflecting unit 12, and the light that hits the inner surface 12c of the light reflecting unit 12 from the light emitting unit 11 side is directed to the light emitting unit 11 side. Can be reflected in.

(Membrane 15)
The film 15 is a light-scattering film containing a particulate substance. The film 15 can mainly scatter light having a wavelength in the range of 320 nm or more and 530 nm or less, for example. Here, the particulate state means a state in which the film 15 does not have to be continuously formed and contains independent particles. However, some particles may be connected to each other. The shape of the particles may be any shape including a spherical shape, a flat shape, a star shape, an indefinite shape, and the like.

In the film 15, the ratio of the particulate matter to the area of the region in which the film 15 is formed is preferably 30% or more and 80% or less. By satisfying this ratio, the effect of scattering incident light can be sufficiently obtained. In the region where the film 15 is formed, the ratio of the particulate substance to the area of the region can be measured by image processing the SEM photograph (scanning electron micrograph) of the film 15.

The film thickness of the film 15 is preferably 10 nm or more and 70 nm or less, and more preferably 30 nm or more and 50 nm or less. If the film thickness becomes too thick, the luminous efficiency decreases, so that the film 15 is required to be formed with an appropriate thickness. Further, when the film thickness of the film 15 is 10 nm or more and 70 nm or less, the effect that the substance contained in the film 15 is sufficiently atomized and the incident light is scattered can be sufficiently obtained. When the film thickness of the film 15 is 30 nm or more and 50 nm or less, the number of independent particles of the substance contained in the film 15 increases, and the effect of scattering the incident light becomes even greater.

The particulate matter contained in the film 15 preferably has a large refractive index in order to obtain the effect of scattering. The refractive index of the particulate matter contained in the film 15 is, for example, 2 or more. The particulate matter contained in the film 15 is, for example, niobium oxide. Further, the material forming the film 15 does not include a material different from the particulate substance. The refractive index of niobium oxide is about 2.3 to 2.4. As the particulate matter contained in the film 15, it is preferable to use a material having a high refractive index. Specifically, as the niobium oxide, niobium oxide (Nb ₂ O ₅ ) can be mentioned as an example. Examples of the material having a high refractive index include tantalum oxide, zirconium oxide, titanium oxide and the like.

(Light emitting member 10)
The film 15 is formed on at least the upper surface 11a of the light emitting portion 11. The film 15 may be extended from the upper surface 11a of the light emitting portion 11 to the upper surface 12a of the light reflecting portion 12. The film 15 may be formed on the entire surface of the upper surface 11a of the light emitting portion 11 and the upper surface 12a of the light reflecting portion 12 (that is, the entire surface of the upper surface of the composite member 13).

The film 15 has a refractive index difference of 0.3 or more between the film 15 and the light emitting unit 11. When the difference in refractive index between the film 15 and the light emitting unit 11 is 0.3 or more, the effect of scattering the incident light can be sufficiently obtained. The larger the difference in refractive index between the film 15 and the light emitting unit 11, the greater the effect of scattering incident light, which is preferable.

When the main material of the light emitting unit 11 is aluminum oxide, the refractive index of the light emitting unit 11 is about 1.6 to 1.8. On the other hand, when the particulate matter contained in the film 15 is niobium oxide, the refractive index of the film 15 is about 2.3 to 2.4 as described above. That is, in this case, the difference in refractive index between the film 15 and the light emitting unit 11 is 0.3 or more. Further, a refractive index difference of 0.8 between the film 15 and the light emitting unit 11 can be realized. As an example, the difference in refractive index can be obtained from the refractive index of the main material in each of the film 15 and the light emitting unit 11. In this case, the main material occupies 50% or more in its constituents.

In the light emitting member 10, the upper surface 11a side of the light emitting unit 11 on which the film 15 is formed is the light emitting side, and the lower surface 11b side of the light emitting unit 11 is the light incident side. That is, the light incident on the light emitting unit 11 is emitted via the film 15. A part of the light may also be incident on the lower surface 12b of the light reflecting portion 12.

The light reflecting unit 12 reflects the light directed from the light emitting unit 11 toward the light reflecting unit 12 on the inner surface surface 12c. The light directed from the light emitting unit 11 to the light reflecting unit 12 is the light incident on the light emitting unit 11. When the light emitting unit 11 is a wavelength conversion unit having a phosphor, the light reflecting unit 12 reflects the light incident on the light emitting unit 11 or the light wavelength-converted by the light emitting unit 11 on the inner side surface 12c. The light reflecting unit 12 is preferably formed of a material having a high thermal conductivity that exhausts the heat generated by the light emitting unit 11. The light reflecting portion 12 can be formed of, for example, aluminum oxide (Al ₂ O ₃ ), which is a ceramic material having high thermal conductivity.

The light emitting member 10 may have a film other than the film 15. For example, a light-shielding film may be formed from a metal or the like on the film 15 formed on the upper surface 12a of the light reflecting portion 12. The light-shielding film can be formed, for example, with a film thickness in the range of 50 nm or more and 500 nm or less. By providing the light-shielding film, it is possible to suppress leakage of light from other than the film 15 formed on the upper surface 11a of the light emitting portion 11 which is the light emitting surface. Further, the film 15 may be provided on the light-shielding film.

(Manufacturing method of light emitting member 10)
FIG. 3 is a diagram illustrating a method for manufacturing a light emitting member according to the first embodiment. First, as shown in FIG. 3, the composite member 13 is prepared. The composite member 13 can be prepared, for example, by manufacturing from the light emitting unit 11 and the light reflecting unit 12. Alternatively, instead of manufacturing the composite member 13, it may be prepared by procuring the composite member 13.

When the composite member 13 is manufactured, the composite member 13 can be manufactured, for example, by joining the side surface 11c of the light emitting portion 11 and the inner side surface 12c of the light reflecting portion 12 with an adhesive. Alternatively, the composite member 13 can be formed, for example, by integrally sintering the light emitting portion 11 and the light reflecting portion 12. In this case, for example, the material of the powder particles forming the light emitting portion 11 and the light reflecting portion 12 of the sintered body can be integrally molded and sintered. For sintering, for example, a normal pressure sintering method, a discharge plasma sintering method (SPS method), a hot press sintering method (HP method) and the like can be used.

Next, as shown in FIG. 4, a film 15 is formed at least on the upper surface 11a of the light emitting portion 11. The film 15 is, for example, a film containing a niobium oxide. The film 15 may be formed on the entire surface of the upper surface 11a of the light emitting portion 11 and the upper surface 12a of the light reflecting portion 12. The film 15 can be formed, for example, by a sputtering method. At this point, the film 15 is formed continuously rather than in the form of particles. After forming the film 15, the film 15 is heated. By the step of heating the membrane 15, the substance contained in the membrane 15 is atomized. That is, by the step of heating the film 15, the film 15 containing the particleized substance is formed. By the step of heating the membrane 15, the substance contained in the membrane 15 is atomized, and for example, in the region where the membrane 15 is formed, the ratio of the particulate matter to the area of the region is 30% or more and 80. % Or less. As a result, the light emitting member 10 is completed. In the step of forming the film 15, the film 15 may not contain niobium oxide, and may be niobium simple substance or niobium nitride. If the heating atmosphere in the step of heating the film 15 is an oxidizing atmosphere, even if a niobium or niobium nitride film is formed, it can be similarly atomized.

From the viewpoint of atomizing the substance contained in the film 15, the film thickness of the film 15 is preferably 10 nm or more and 70 nm or less, and more preferably 30 nm or more and 50 nm or less. Further, from the viewpoint of atomizing the substance contained in the membrane 15, it is preferable to heat the membrane 15 at a temperature of 850 ° C. or higher and 1000 ° C. or lower, and it is more preferable to heat the membrane 15 at a temperature of 900 ° C. or higher and 950 ° C. or lower. preferable. Further, the heat treatment is preferably performed in an atmospheric atmosphere for about 1 hour. Further, it is preferable that the heat treatment does not exceed 10 hours in the atmospheric atmosphere. This makes it possible to create a good state of particle formation. The heating temperature mentioned here is a temperature condition at atmospheric pressure.

It should be noted that the step may be a step of preparing only the light emitting portion 11 in the step of FIG. 3, forming the film 15 on the upper surface 11a of the light emitting portion 11 in the step of FIG. 4, and then heating the film 15. In this case, a light emitting member 10 having a light emitting portion 11 and a film 15 and not having a light reflecting portion 12 is manufactured.

(Light scattering property of film 15)
5 to 10 are SEM photographs relating to the particleization of niobium oxide. FIG. 5 is an SEM photograph of the film of niobium oxide before heating. FIG. 6 is an SEM photograph of a niobium oxide film after heating at 800 ° C. for 1 hour (1 hour) under atmospheric pressure. FIG. 7 is an SEM photograph of a film of niobium oxide after heating at 850 ° C. for 1 hour under atmospheric pressure. FIG. 8 is an SEM photograph of a film of niobium oxide after heating at 900 ° C. for 1 hour under atmospheric pressure. FIG. 9 is an SEM photograph of a film of niobium oxide after heating at 950 ° C. for 1 hour under atmospheric pressure. FIG. 10 is an SEM photograph of a film of niobium oxide after heating at 1000 ° C. for 1 h under atmospheric pressure.

From FIG. 5, it can be confirmed that the film of niobium oxide before heating is continuously formed rather than in the form of particles. Further, as shown in FIGS. 6 to 10, the degree of particleization of niobium oxide changes depending on the heating temperature, and although the degree of particle formation is at 800 ° C., the degree of particle formation is low and there are many continuous parts. The heating temperature for forming particles is preferably 850 ° C. or higher and 1000 ° C. or lower. Further, the heating temperature is more preferably 900 ° C. or higher and 950 ° C. or lower, which has a large proportion of particles.

11 to 16 are SEM photographs showing the difference in the mode of particle formation of niobium oxide depending on the film thickness of niobium oxide (heating condition: 950 ° C. 1h under atmospheric pressure). FIG. 11 is an SEM photograph of a film formed by heating a niobium oxide film having a film thickness of 5 [nm] at 950 ° C. for 1 hour under atmospheric pressure. FIG. 12 is an SEM photograph of a film formed by heating a niobium oxide film having a film thickness of 10 [nm] at 950 ° C. for 1 hour under atmospheric pressure. FIG. 13 is an SEM photograph of a film formed by heating a niobium oxide film having a film thickness of 30 [nm] at 950 ° C. for 1 hour under atmospheric pressure. FIG. 14 is an SEM photograph of a film formed by heating a niobium oxide film having a film thickness of 50 [nm] at 950 ° C. for 1 hour under atmospheric pressure. FIG. 15 is an SEM photograph of a film formed by heating a niobium oxide film having a film thickness of 70 [nm] at 950 ° C. for 1 hour under atmospheric pressure. FIG. 16 is an SEM photograph of a film formed by heating a niobium oxide film having a film thickness of 100 [nm] at 950 ° C. for 1 hour under atmospheric pressure.

From FIGS. 11 to 16, it can be seen that the film thickness may not be too thin or too thick in order to atomize the niobium oxide film, and there is a suitable film thickness range. Specifically, looking at the degree of particle formation, in order to atomize the niobium oxide film, the film thickness of niobium oxide is preferably 10 nm or more and 70 nm or less, and the number of independent particles increases. More preferably, it is 30 nm or more and 50 nm or less. The more independent particles there are, the higher the effect of scattering.

Considering the results of FIGS. 11 to 16 together with the results of FIGS. 5 to 10, in order to atomize the film of niobium oxide, the niobium oxide is formed into a film having a film thickness of 10 nm or more and 70 nm or less, and 850. It can be said that it is preferable to heat the particles at a temperature of ° C. or higher and 1000 ° C. or lower. Further, a more preferable condition for atomizing the niobium oxide film is to form a niobium oxide film with a film thickness of 30 nm or more and 50 nm or less, and heat the niobium oxide at a temperature of 900 ° C. or more and 950 ° C. or less. The heating temperature mentioned here is a temperature condition at atmospheric pressure.

17 to 20 are diagrams illustrating changes in the linear transmittance of niobium oxide films having different film thicknesses before and after heating. FIG. 17 is a diagram illustrating changes in linear transmittance before and after heating of a film of niobium oxide having a film thickness of 10 [nm]. FIG. 18 is a diagram illustrating a change in linear transmittance before and after heating a film of niobium oxide having a film thickness of 30 [nm]. FIG. 19 is a diagram illustrating a change in linear transmittance before and after heating a film of niobium oxide having a film thickness of 50 [nm]. FIG. 20 Oxidation with a film thickness of 70 [nm] is a diagram illustrating a change in linear transmittance before and after heating of a niobium film.

In FIGS. 17 to 20, in the measurement sample, a film of niobium oxide having a predetermined film thickness (10 nm, 30 nm, 50 nm, 70 nm) is formed on one surface of a plate-shaped sapphire having a thickness of about 400 μm whose both sides are mirror-finished. Is formed. Then, samples having different film thicknesses and heating temperatures were prepared, and the linear transmittances of each sample before and after heating the niobium oxide film were measured and shown in FIGS. 17 to 20.

Here, the linear transmittance is the ratio of the light emitted vertically from the niobium oxide film to the light vertically incident on the plane of the plate-shaped sapphire. In FIGS. 17 to 20, "sapphire" indicates the linear transmittance of sapphire in which niobium oxide is not formed, and "after film formation" indicates the linear transmittance before heating.

As shown in FIGS. 17 to 20, the film of niobium oxide after heating has a thickness of 400 nm to 800 nm as compared with the film of niobium oxide before heating at any of the film thicknesses of 10 nm, 30 nm, 50 nm, and 70 nm. The linear transmittance decreases in the wavelength range. Further, in the range of 800 ° C. to 950 ° C., the higher the heating temperature, the greater the decrease in the linear transmittance on the short wave side, and the difference from the long wave side tends to widen. On the other hand, at 1000 ° C., the linear transmittance on the short wave side tends to be higher than that at 950 ° C.

The reason why the linear transmittance on the short wave side decreases in the heating temperature range of 800 ° C. to 950 ° C. is that the film of niobium oxide is atomized by heating and scatters incident light. This is considered to be a phenomenon similar to Rayleigh scattering. From the results of FIGS. 5 to 16 described above, in order to atomize the niobium oxide film, the niobium oxide is formed with a film thickness of 30 nm or more and 50 nm or less, and the temperature is 900 ° C. or more and 950 ° C. or less under atmospheric pressure. It is preferable to heat at a temperature. Also in FIGS. 17 to 20, the linear transmittance on the short wave side decreases in a wide wavelength range when heated at 950 ° C., and the niobium oxide film is appropriately atomized by heating at 950 ° C., which is ideal. It can be said that a typical scattering can be obtained.

In FIGS. 17 to 20, the linear transmittance on the short wave side is reduced to some extent even in the film before heating, but this is not because the scattering increases due to particle formation, but because of the influence of the refractive index of the film of nioboxide. This is because the light transmitted through the film has decreased.

In this way, by heating the niobium oxide film into particles, light scattering by the niobium oxide particles increases, the linear transmittance on the short wave side decreases, and the difference from the long wave side tends to widen. be. By utilizing this characteristic, as described below, it is possible to reduce color unevenness and / or luminance unevenness of the light emitted from the light emitting surface of the light emitting member 10.

For example, in the light emitting member 10 shown in FIG. 1 and the like, the film 15 is a film of niobium oxide after heating, and light in the wavelength range on the short wave side shown in FIGS. 17 to 20 is incident from the lower surface 11b side of the light emitting unit 11. In that case, the incident light can be scattered. For example, when laser light having a emission peak wavelength in the range of 320 nm or more and 530 nm or less is incident from the lower surface 11b side of the light emitting portion 11, the laser light is diffused and the intensity difference between the central portion and the outer peripheral portion of the light emitting surface becomes small. Therefore, it is possible to reduce color unevenness and / or luminance unevenness of the light emitted from the light emitting surface of the light emitting member 10.

Further, in the light emitting member 10 shown in FIG. 1 and the like, the light emitting unit 11 is a wavelength conversion unit having YAG as a phosphor, and the film 15 is a film of niobium oxide after heating. For example, from the lower surface 11b side of the light emitting unit 11. When a laser beam having a emission peak wavelength in the range of 420 nm or more and 480 nm or less is incident, white light is emitted from the light emitting surface of the light emitting member 10. In this case as well, the same effect as described above can be obtained. That is, since the laser beam is diffused and the intensity difference between the central portion and the outer peripheral portion of the light emitting surface of the light emitting member 10 becomes small, the color unevenness and / or the luminance unevenness of the white light emitted from the light emitting surface of the light emitting member 10 becomes uneven. Can be reduced.

Further, by diffusing the laser light, the laser light returned by scattering can be excited by the phosphor of the light emitting unit 11 and converted into fluorescence. As a result, the concentration of the phosphor (volume of the phosphor) can be reduced, and the temperature characteristics of the light emitting unit 11 (wavelength conversion unit) can be improved.

FIG. 21 is a diagram illustrating the relationship between the output of the laser beam input to the light emitting member and the luminous efficiency, and shows data when the film thickness of the film 15 is 30 nm as a representative. The sample is a light emitting member 10 in which the light emitting unit 11 has a wavelength conversion unit having YAG as a phosphor and the film 15 is a film of niobium oxide having a film thickness of 30 nm. An integrating sphere was used for the measurement. In addition, as a reference, measurements were also made on a sample in which a film of niobium oxide was not formed.

As shown in FIG. 21, it can be seen that the luminous efficiency is improved by having the light emitting portion 11 having the film 15 of the niobium oxide after heating. This is because a part of the laser light incident from the lower surface 11b side of the light emitting unit 11 is backward scattered by the film 15 to the lower surface 11b side, and the phosphor is reexcited by the back scattering and emitted from the light emitting surface of the light emitting member 10. It is probable that the amount of fluorescent light increased. Increasing the amount of phosphor light is also advantageous in reducing color unevenness and / or luminance unevenness.

<Second Embodiment>
The second embodiment shows an example of an optical member using the light emitting member according to the first embodiment. In the second embodiment, the description of the same component as that of the above-described embodiment may be omitted.

FIG. 22 is a perspective view illustrating the optical member according to the second embodiment. FIG. 23 is a cross-sectional view taken along the line XXIII-XXIII of FIG. 22, illustrating the optical member according to the second embodiment. As shown in FIGS. 22 and 23, the optical member 20 has a light emitting member 10 and a plate-shaped member 21.

Each component of the optical member 20 will be described.

(Plate-shaped member 21)
The plate-shaped member 21 is a translucent member. The plate-shaped member 21 has an upper surface 21a, a lower surface 21b opposite to the upper surface 21a, and a side surface 21c intersecting the upper surface 21a and the lower surface 21b. The side surface 21c connects the outer edge of the upper surface 21a and the outer edge of the lower surface 21b. The plate-shaped member 21 is, for example, a rectangular parallelepiped or a cube. In this case, the upper surface 21a and the lower surface 21b of the plate-shaped member 21 are both rectangular, and the plate-shaped member 21 has four rectangular side surfaces 21c.

However, the plate-shaped member 21 is not limited to a rectangular parallelepiped or a cube. That is, the planar shape of the plate-shaped member 21 is not limited to a rectangle, and can be any shape such as a circle, an ellipse, or a polygon.

The plate-shaped member 21 has a base material having a flat plate shape such as a rectangular parallelepiped. The base material of the plate-shaped member 21 can be formed, for example, by using sapphire as the main material. Sapphire is a material with relatively high transmittance and relatively high strength. In addition to sapphire, a translucent material containing, for example, quartz, silicon carbide, glass, or the like may be used as the main material.
Can be used.

(Optical member 20)
In the optical member 20, the surface of the light emitting member 10 on the side where the film 15 is not formed is joined to the upper surface 21a of the plate-shaped member 21. That is, the plate-shaped member 21 is arranged on the lower surface 11b side of the light emitting portion 11 and the lower surface 12b side of the light reflecting portion 12. The light emitting member 10 forms, for example, a metallized film on a part of the region where the light emitting member 10 is arranged on the upper surface 21a of the plate-shaped member 21 and a part of the lower surface 12b of the light reflecting portion 12, and the metallized films are formed with each other. By fixing with solder such as Au-Sn, it can be joined to the plate-shaped member 21. When the base material of the plate-shaped member 21 is sapphire, the sapphire is a material having a relatively high thermal conductivity, so that the heat generated by the light emitting member 10 can be dissipated.

Since the plate-shaped member 21 is translucent, the light incident from the lower surface 21b side of the plate-shaped member 21 reaches the film 15 via the light emitting unit 11 and is emitted from the film 15 side. Therefore, the same effect as that of the light emitting member 10 can be obtained by scattering due to the particle nature of the film 15.

A mechanism for detecting destruction may be provided between the light emitting member 10 and the plate-shaped member 21. The mechanism of fracture detection is, for example, to join a wiring pattern provided on the lower surface side of the light emitting member 10 and a wiring pattern provided on the upper surface 21a side of the plate-shaped member 21 by using solder such as Au-Sn. It can be realized by.

For example, the wiring pattern provided between the light emitting member 10 and the plate-shaped member 21 is electrically connected to the detection circuit arranged outside the optical member 20. Then, the detection circuit monitors the change in the resistance value of the wiring pattern, and when the resistance value changes beyond a predetermined threshold value, the destruction of the light emitting member 10 and / or the plate-shaped member 21 can be detected.

Since the plate-shaped member 21 is translucent, the mechanism for detecting the destruction provided between the light emitting member 10 and the plate-shaped member 21 can be visually recognized from the lower surface 21b side of the plate-shaped member 21. Therefore, in the manufacturing process of the optical member 20, it is possible to confirm whether or not the mechanism for detecting fracture is properly joined, and the quality can be stabilized.

<Third Embodiment>
In the third embodiment, an example of a light emitting device using the optical member according to the second embodiment is shown. In the third embodiment, the description of the same component as that of the above-described embodiment may be omitted.

FIG. 24 is a perspective view illustrating the light emitting device according to the third embodiment. FIG. 25 is a cross-sectional view taken along the line XXV-XXV of FIG. 24, illustrating the light emitting device according to the third embodiment. FIG. 26 is a perspective view showing a state in which the optical member is further removed from the light emitting device according to the third embodiment. FIG. 27 is a plan view showing a state in which the optical member is further removed from the light emitting device according to the third embodiment.

As shown in FIGS. 24 to 27, the light emitting device 200 includes an optical member 20, a base 210, a light emitting element 220, a submount 230, a light reflecting member 240, a protective element 250, and a temperature measuring element 260. It has a wiring 270 and a light-shielding member 280. The light emitting device 200 may have at least an optical member 20, a base 210, and a light emitting element 220. Further, the light emitting device 200 may have a light emitting member 10 instead of the optical member 20.

Each component of the light emitting device 200 will be described.

(Base 210)
The base 210 has an upper surface 210a, a lower surface 210b, a plurality of inner side surfaces 210c, one or a plurality of outer surface surfaces 210d, and a bottom surface 210e. The base 210 has a concave shape recessed in the direction from the upper surface 210a to the lower surface 210b. Further, the base portion 210 has a rectangular outer shape in a plan view, and a recess is formed inside the outer outer shape.

Further, in a plan view, a frame is formed by one or a plurality of inner side surfaces 210c intersecting the upper surface 210a. That is, the base 210 includes a bottom surface 210e and a frame forming an inner side surface 210c extending above the bottom surface 210e. The recess including the bottom surface 210e of the base 210 is surrounded by this frame.

Further, the base portion 210 has one or a plurality of stepped portions 216 inside the frame. The step portion 216 is composed of only the upper surface and the side surface that intersects the upper surface and advances downward. The one or more inner side surfaces 210c include a side surface that intersects the upper surface 210a of the base portion 210 and a side surface of the step portion 216.

The base 210 can be formed, for example, using ceramics as a main material. For example, aluminum nitride, silicon nitride, aluminum oxide, or silicon carbide can be used as the ceramics. The base 210 is not limited to ceramics, and may be formed by using another material having an insulating property as a main material.

Further, one or more metal films are provided on the bottom surface 210e of the base 210. Further, one or more metal films are provided on the upper surface 210a of the base 210. Further, the one or more metal films provided on the bottom surface 210e include a metal film electrically connected to the metal film provided on the top surface 210a.

The frame of the base 210 may not be provided on the same plane as the bottom surface 210e. For example, the frame of the base 210 may be provided on a flat surface recessed from the bottom surface 210e. Further, the base 210 is not integrally formed, and may be, for example, a frame joined on a plate-shaped member.

(Light emitting element 220)
The light emitting element 220 is not particularly limited as long as it is an element that emits light, and for example, a semiconductor laser element, a light emitting diode (LED), or an organic light emitting diode (OLED) can be used. In this embodiment, as an example, an example in which a semiconductor laser element is used as the light emitting element 220 is shown. That is, the light emitting element 220 in the following description is a semiconductor laser element.

The light emitting element 220 has, for example, a rectangular outer shape in a plan view. Further, the side surface that intersects with one of the two short sides of the rectangle is the emission end surface of the light emitted from the light emitting element 220. Further, the upper surface and the lower surface of the light emitting element 220 have a larger area than the emission end surface.

The light (laser light) emitted from the light emitting element 220 has a spread and forms an elliptical furfield pattern (hereinafter referred to as "FFP") on a surface parallel to the emission end surface of the light. Here, FFP indicates the shape and light intensity distribution of the emitted light at a position away from the emission end face.

The light emitted from the light emitting element 220 is an elliptical FFP having a minor axis in the layer direction of a plurality of semiconductor layers including an active layer and a major axis in the stacking direction perpendicular to the layer direction of a plurality of semiconductor layers including the active layer in a plane parallel to the emission end surface of the light. Form. The layer direction corresponding to the minor axis is referred to as the horizontal direction of FFP, and the stacking direction corresponding to the major axis is referred to as the vertical direction of FFP.

Further, the light having an intensity of 1 / e ² or more with respect to the peak intensity value based on the light intensity distribution of the FFP of the light emitting element 220 is referred to as the light of the main portion. Further, the angle corresponding to the full width at half maximum of this light intensity distribution is referred to as an extended angle. The vertical spread angle of the FFP is referred to as the vertical spread angle, and the horizontal spread angle of the FFP is referred to as the horizontal spread angle.

As the light emitting element 220, one having an emission peak wavelength of light emitted from the light emitting element 220 in the range of 320 nm to 530 nm, typically in the range of 430 nm to 480 nm can be used. Examples of such a light emitting device 220 include a semiconductor laser device including a nitride semiconductor. As the nitride semiconductor, for example, GaN, InGaN, or AlGaN can be used. The wavelength of the light emitted from the light emitting element 220 is not limited to this.

(Sub mount 230)
The submount 230 is configured, for example, in the shape of a rectangular parallelepiped and has a lower surface, an upper surface, and side surfaces. Further, the submount 230 has the smallest width in the vertical direction. The shape is not limited to a rectangular parallelepiped. The submount 230 is formed using, for example, aluminum nitride or silicon carbide, but other materials may be used. Further, a metal film is provided on the upper surface of the submount 230.

(Light Reflecting Member 240)
The light reflecting member 240 has a light reflecting surface 241 that reflects light. The light reflecting surface is provided with, for example, a surface having a light reflectance of 90% or more with respect to the peak wavelength of the irradiated light. The light reflectance here may be 100% or less than 100%.

Further, the light reflecting member 240 has a plurality of light reflecting surfaces 241. Each of the plurality of light reflecting surfaces 241 has a planar shape and is inclined with respect to the lower surface, and includes two light reflecting surfaces 241 having different inclination angles with respect to the lower surface. Neither of these two light reflecting surfaces 241 has a vertical or parallel arrangement with respect to the lower surface. Further, the two light reflecting surfaces 241 are continuously connected to form one integrated reflecting region. The shape of the light reflecting surface 241 is not limited to a planar shape, and may be, for example, a curved surface shape.

For the light reflecting member 240, it is preferable to select a heat-resistant material as the main material, and for example, glass such as quartz or BK7 (borosilicate glass), metal such as aluminum, or Si can be used. Further, the light reflecting surface can be formed by using, for example, a metal such as Ag or Al or a dielectric multilayer film of Ta ₂ O ₅ / SiO ₂ , TIO ₂ / SiO ₂ , or Nb ₂ O ₅ / SiO ₂ . Note that A / B indicates a multilayer film in which the film A and the film B are laminated in order.

(Protective element 250)
The protective element 250 is for preventing an excessive current from flowing to a specific element such as a light emitting element and destroying the element. As the protection element 250, for example, a Zener diode made of Si can be used.

(Temperature measuring element 260)
The temperature measuring element 260 is an element used as a temperature sensor for measuring the ambient temperature. As the temperature measuring element 260, for example, a thermistor can be used.

(Wiring 270)
Wiring 270 is used for the electrical connection between the two components. As the wiring 270, for example, a metal wire can be used.

(Shading member 280)
The light-shielding member 280 can be formed of, for example, a resin having a light-shielding property. Here, the light-shielding property indicates a property of not transmitting light, and the light-shielding property may be realized by utilizing the property of absorbing light, the property of reflecting light, and the like in addition to the property of blocking light. The light-shielding member 280 can be formed, for example, by including a filler such as a light diffusing material and / or a light absorbing material in a resin.

Examples of the resin forming the light-shielding member 280 include epoxy resin, silicone resin, acrylate resin, urethane resin, phenol resin, BT resin and the like. Examples of the light-absorbing filler contained in the light-shielding member 280 include dark-colored pigments such as carbon black.

(Light emitting device 200)
In the light emitting device 200, two light reflecting members 240 are arranged on the bottom surface 210e of the base 210. The two light reflecting members 240 are arranged on different metal films, and the lower surface thereof is joined to the bottom surface 210e of the base 210. Further, the two light reflecting members 240 are arranged point-symmetrically with respect to the point SP (see FIG. 27), for example. Further, in the two light reflecting members 240, the upper end of the light reflecting surface 241 is parallel or perpendicular to the inner surface 210c or the outer surface 210d of the base 210 in a plan view. In addition, parallel or vertical here allows a difference within ± 5 degrees.

A protective element 250 and a temperature measuring element 260 are arranged on the bottom surface 210e of the base 210. The protective element 250 is arranged and joined to a metal film in which one of the two light reflecting members 240 is arranged. The temperature measuring element 260 is arranged and joined on a metal film different from the metal film on which the two light reflecting members 240 are arranged.

Two submounts 230 are arranged on the bottom surface 210e of the base 210. The two submounts 230 are respectively arranged on different metal films, the lower surface of which is joined to the bottom surface 210e of the base 210. Further, each of the two submounts 230 is arranged on a metal film in which the light reflecting member 240 is arranged. The submount 230 and the light reflecting member 240 may be arranged on different metal films.

The light emitting element 220 is arranged on the bottom surface 210e of the base 210. Specifically, the light emitting element 220 is arranged on the submount 230. In the illustrated example of the light emitting device 200, two light emitting elements 220 are arranged on the upper surface of different submounts 230, and the lower surface of the submount 230 is joined to the bottom surface 210e of the base 210. Further, the two light emitting elements 220 are arranged point-symmetrically with respect to the point SP. That is, the point where the two light emitting elements 220 are symmetrical and the point where the two light reflecting members 240 are symmetrical are at the same position. In the following description, this point SP will be referred to as a point of symmetry.

In the plan view, the emission end faces of the two light emitting elements 220 are not parallel to or perpendicular to the inner side surface 210c or the outer side surface 210d of the base 210. Therefore, the emission end surface is not parallel or perpendicular to the upper end of the light reflection surface 241. That is, the light emitting element 220 is arranged so that the emission end surface is slanted with respect to the inner side surface 210c and the outer surface 210d of the base portion 210 or the upper end of the light reflection surface 241 in a plan view.

Instead of arranging the light emitting element 220 diagonally, the light reflecting member 240 may be arranged diagonally. That is, the light emitting element 220 may be arranged parallel or perpendicular to the inner side surface 210c or the outer side surface 210d of the base 210, and the light reflecting member 240 may be arranged so as not to be parallel and perpendicular to each other. In addition, parallel or vertical here allows a difference within ± 5 degrees.

The light emitted from the emission end face of each of the two light emitting elements 220 irradiates the corresponding light reflecting member 240. The corresponding light reflecting member 240 is a light reflecting member 240 arranged on the same metal film. The light emitting element 220 is arranged so that the light of at least the main portion is irradiated to the light reflecting surface 241.

Further, between the corresponding light emitting element 220 and the light reflecting member 240, the light emitting element 220 is located farther from the point of symmetry than the light reflecting member 240. Therefore, the light emitted from the light emitting element 220 travels in the direction approaching the point of symmetry. Further, at least one of the two light emitting elements 220 is arranged at a position close to the temperature measuring element 260. Thereby, the temperature of the light emitting element 220 can be measured satisfactorily.

The submount 230 in which the light emitting element 220 is arranged serves as a heat radiating member in the light emitting device 200 to release heat generated from the light emitting element 220. In order to make the submount 230 function as a heat radiating member, it may be formed of a material having a higher thermal conductivity than the light emitting element 220. Further, if the base 210 is made of a material having a higher thermal conductivity than the bottom surface 210e, a higher heat dissipation effect can be obtained.

Further, the submount 230 can play a role of adjusting the light emission position of the light emitting element 220 in the light emitting device 200. For example, the submount 230 can be used as an adjusting member when it is desired to make the light passing through the optical axis horizontal to the bottom surface 210e and to irradiate a predetermined position on the light reflecting surface 241.

The light emitting element 220, the protective element 250, and the temperature measuring element 260 are electrically connected to a metal film provided on the bottom surface 210e of the base 210 via the corresponding wiring 270. A metal film provided on the bottom surface 210e of the base 210 is used for electrical connection between these elements and an external power source. As a result, these elements and the external power supply can be electrically connected via the metal film on the upper surface 210a of the base 210.

The plate-shaped member 21 of the optical member 20 is arranged on the upper surface side of the base 210. Specifically, the outer peripheral portion of the lower surface 21b of the plate-shaped member 21 is joined to the upper surface of the stepped portion 216 of the base portion 210. By joining the plate-shaped member 21 to the base 210, a closed space in which the light emitting element 220 is arranged is formed. As described above, in the light emitting device 200, the plate-shaped member 21 can serve as a lid member. Further, this closed space is formed in an airtightly sealed state. By hermetically sealing, it is possible to suppress the collection of organic substances and the like on the light emitting end surface of the light emitting element 220.

When the light emitting member 10 is used instead of the optical member 20, for example, the light reflecting portion 12 of the light emitting member 10 is set to an appropriate size, and the outer peripheral portion of the lower surface 12b of the light reflecting portion 12 is the stepped portion 216 of the base 210. It may be joined to the upper surface of.

The main portion of the light emitted by the light emitting element 220 is reflected by the light reflecting surface 241 of the light reflecting member 240 and is incident on the plate-shaped member 21. The plate-shaped member 21 has translucency with respect to the light emitted by the light emitting element 220. Further, the main portion of the light passes through the plate-shaped member 21 and then enters the light emitting portion 11 of the light emitting member 10 constituting the optical member 20.

The light emitting member 10 has a light incident region in which the light of the main portion is incident and a peripheral region thereof on the lower surface thereof. Further, in the light emitting member 10, the light emitting unit 11 forms a light incident region. In the light emitting member 10, when the light emitting unit 11 is a wavelength conversion unit having a phosphor, the light emitting unit 11 emits a second light obtained by converting the first light emitted from the light emitting element 220 into light having a different wavelength. do.

The first light emitted from the light emitting element 220 or the second light wavelength-converted by the light emitting unit 11 is emitted to the outside of the light emitting device 200 via the film 15 formed on the upper surface 11a of the light emitting unit 11. Ru. That is, the upper surface of the film 15 formed on the upper surface 11a of the light emitting unit 11 becomes the light emitting surface of the light emitting device 200. In the light emitting member 10, when the light emitting unit 11 is a wavelength conversion unit having a phosphor, the film 15 reduces the amount of light emitted from the first light and emits the second light as compared with the state in which the film 15 is not formed. Increase the amount.

If the heat generated by the wavelength conversion is concentrated in a specific place, the light conversion efficiency by the light emitting unit 11 tends to decrease. Therefore, it is preferable that the distribution of the light incident on the light emitting unit 11 is diffused. For example, it is preferable that the portions having strong light intensity of the laser light emitted from each of the two light emitting elements 220 do not overlap. For example, such control is possible by adjusting the light reflecting surface 241 of the light reflecting member 240.

The light-shielding member 280 is formed inside the frame formed by the upper surface 210a of the base 210. The light-shielding member 280 is formed so as to fill the gap between the base 210 and the light-emitting member 10. The light-shielding member 280 can be formed, for example, by pouring a thermosetting resin and curing it with heat. By providing the light-shielding member 280, light leakage is suppressed.

The light-shielding member 280 is in contact with the inner side surface 210c intersecting the upper surface 210a of the base portion 210, the upper surface of the step portion 216 of the base portion 210, the side surface of the plate-shaped member 21, the upper surface of the plate-shaped member 21, and the side surface of the light emitting member 10. Further, it does not reach the upper surface of the light emitting member 10. Alternatively, even if it reaches the upper surface of the light reflecting unit 12, it does not reach the upper surface of the light emitting unit 11. If it is difficult for the light-shielding member 280 to achieve high-precision light-shielding up to the boundary between the light-emitting unit 11 and the light-reflecting unit 12, as described above, the light-emitting member 10 is placed on the upper surface 12a of the light-reflecting unit 12. It is preferable to form a light-shielding film on the formed film 15. As a result, in the light emitting device 200, leakage of light from other than the light emitting surface can be suppressed with high accuracy.

Since the light emitting device 200 is equipped with a light emitting member 10 having a light scattering film 15 containing a particulate substance, the laser light from the light emitting element 220 reaches the film 15 and is diffused to the center of the light emitting surface. The difference in strength between the portion and the outer peripheral portion becomes small. Therefore, in the light emitting device 200, it is possible to reduce color unevenness and / or luminance unevenness of the light emitted from the light emitting surface. When the light emitting element 220 is a semiconductor laser element, light having a small spot diameter is emitted, so that a high effect can be expected by reducing color unevenness and / or luminance unevenness of the light due to scattering.

When the light emitting portion 11 of the light emitting member 10 has a YAG phosphor and the light emitting element 220 is a semiconductor laser element that emits blue light in the range of emission peak wavelength of 420 nm or more and 480 nm or less, it is assumed that the film 15 is not formed. In the emitted light, a portion having a high directional blue color and a portion having a strong phosphor color are likely to occur.

On the other hand, since the light emitting device 200 is equipped with a light emitting member 10 having a light scattering film 15 containing a particulate substance, blue with high directivity is scattered. As a result, in the emitted light, the portion having a strong blue color is weakened, and the color unevenness and / or the luminance unevenness of the light emitted from the light emitting surface is reduced. As a result, good white light can be obtained from the light emitting surface.

The light emitting device 200 can be used, for example, for an in-vehicle headlight. Further, the light emitting device 200 is not limited to this, and can be used as a light source for lighting, a projector, a head-mounted display, and other display backlights.

Although the preferred embodiments and the like have been described in detail above, they are not limited to the above-mentioned embodiments and the like, and various modifications and substitutions are made to the above-mentioned embodiments and the like without departing from the scope described in the claims. Can be added.

10 Light emitting member 11 Light emitting part 11a, 12a, 21a, 210a Top surface 11b, 12b, 21b, 210b Bottom surface 11c, 21c Side surface 12 Light reflecting part 12c, 210c Inner side surface 12d, 210d Outer side surface 13 Composite member 15 Film 20 Optical member 21 Plate Shape member 200 Light emitting device 210 Base 216 Stepped part 220 Light emitting element 230 Submount 240 Light reflecting member 241 Light reflecting surface 250 Protecting element 260 Temperature measuring element 270 Wiring 280 Light shielding member

Claims (14)

A light emitting part having a first surface and emitting light,
It has a film formed on the first surface and
The film is a light emitting member having a refractive index difference of 0.3 or more between the film and the light emitting portion, containing particulate matter, and having a film thickness of 10 nm or more and 70 nm or less. A light emitting part having a first surface and emitting light,
It has a film formed on the first surface and
The film has a refractive index difference of 0.3 or more between the film and the light emitting portion, contains particulate matter, and is the particles in the region where the film is formed with respect to the area of the region. A light-emitting member having a shape-like substance occupying 30% or more and 80% or less. The light emitting member according to claim 1 or 2, wherein the light emitting unit is a wavelength conversion unit having a phosphor. The light emitting member according to any one of claims 1 to 3, wherein the substance has a refractive index of 2 or more. The light emitting member according to any one of claims 1 to 4, wherein the substance is a niobium oxide. The light emitting member according to any one of claims 1 to 5, further comprising a light reflecting portion connected to a side surface of the light emitting portion that intersects with the first surface. The light emitting member according to any one of claims 1 to 6.
An optical member having a translucent plate-shaped member arranged on the second surface side, which is the opposite surface of the first surface of the light emitting portion. A base with a bottom surface and a frame surrounding the bottom surface,
The light emitting element arranged on the bottom surface and
It has the light emitting member according to any one of claims 1 to 6 or the optical member according to claim 7.
A light emitting device that seals the space in which the light emitting element is arranged. The light emitting device is a semiconductor laser device that emits first light, and is a semiconductor laser device.
The light emitting device according to claim 8, wherein the light emitting unit emits a second light obtained by converting light emitted from the semiconductor laser element into light having a different wavelength. The semiconductor laser device emits the first light having an emission peak wavelength in the range of 320 nm or more and 530 nm or less.
The light emitting device according to claim 9, wherein the film reduces the amount of light emitted from the first light and increases the amount of light emitted from the second light as compared with a state in which the film is not formed. A process of preparing a light emitting part having a first surface and emitting light, and
The step of forming a film on the first surface and
It has a step of heating the film and
In the step of forming the film, a film containing a substance having a refractive index difference of 0.3 or more from the light emitting portion and having a film thickness of 10 nm or more and 70 nm or less is formed.
A method for manufacturing a light emitting member, in which the film containing the substance is formed into particles by the step of heating the film. A process of preparing a light emitting part having a first surface and emitting light, and
The step of forming a film on the first surface and
It has a step of heating the film and
In the step of forming the film, a film containing a substance having a refractive index difference of 0.3 or more from the light emitting portion is formed.
In the step of heating the film, the substance is atomized, and the ratio of the particulate substance to the area of the region in the region where the film is formed is 30% or more and 80% or less. Manufacturing method of parts. The method for manufacturing a light emitting member according to claim 11 or 12, wherein in the step of heating the film, the film is heated at a temperature of 850 ° C. or higher and 1000 ° C. or lower. The method for producing a light emitting member according to any one of claims 11 to 13, wherein the substance is a niobium oxide.

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