JP7506295B2 - Wavelength conversion member and light emitting device - Google Patents

Description

This disclosure relates to a wavelength conversion member, a light emitting device, and a method for manufacturing a wavelength conversion member.

Light-emitting devices using semiconductor light-emitting elements have been known for some time. For such light-emitting devices, a structure has been proposed in which a heat dissipation member is thermally connected to a wavelength conversion member having a phosphor layer onto which light is irradiated (see, for example, Patent Documents 1 and 2).

JP 2011-028972 A JP 2016-058624 A

However, depending on the manner in which the heat dissipation member and the wavelength conversion member are fixed to each other, the two may become detached from each other.
The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a wavelength conversion member and a light emitting device, as well as a method for manufacturing a wavelength conversion member, that can reduce the possibility of peeling off of a wavelength conversion layer having a phosphor-containing portion from a heat dissipation component.

This application includes the following multiple inventions.
(1) a heat dissipation component having a screw hole;
a wavelength conversion layer disposed on the heat dissipation component, the wavelength conversion layer having a heat conductive portion and a phosphor-containing portion in contact with the heat conductive portion, the wavelength conversion layer having a through hole;
a screw;
The wavelength conversion layer is fixed to the heat dissipation component by the screw that is fitted into the through hole and the screw hole.
(2) A light emitting device comprising: the wavelength conversion member described above; and a light source that irradiates the phosphor-containing portion of the wavelength conversion member with light.
(3) forming a wavelength conversion layer by integrally sintering the thermally conductive portion and the phosphor-containing portion in contact with the thermally conductive portion;
forming a through hole in the wavelength conversion layer;
providing a heat dissipation component having a screw hole;
and fixing the wavelength conversion layer to the heat dissipation component by fitting screws into the through holes and the screw holes.

The above-described wavelength conversion member, light emitting device, and method for manufacturing a wavelength conversion member can reduce the possibility of the wavelength conversion layer peeling off from the heat dissipation component.

FIG. 1 is a schematic plan view illustrating a configuration of a wavelength conversion member according to a first embodiment of the present invention. FIG. 1B is a schematic cross-sectional view taken along line IB-IB in FIG. 1A. 4 is a schematic cross-sectional view showing a modified example of the wavelength conversion member of the first embodiment. FIG. FIG. 4 is a schematic cross-sectional view showing another modified example of the wavelength conversion member of the first embodiment. FIG. 5 is a schematic plan view showing the configuration of a wavelength conversion member according to a second embodiment of the present invention. FIG. 2B is a schematic cross-sectional view taken along line IIB-IIB in FIG. 2A. FIG. 11 is a schematic plan view showing the configuration of a wavelength conversion member according to a third embodiment of the present invention. FIG. 3B is a schematic cross-sectional view taken along line IIIB-IIIB in FIG. 3A. FIG. 11 is a schematic plan view showing the configuration of a wavelength conversion member according to a fourth embodiment of the present invention. 4B is a schematic cross-sectional view taken along line IVB-IVB in FIG. 4A. FIG. 11 is a schematic perspective view showing a configuration of a light emitting device according to a fifth embodiment of the present invention. 3B is a schematic perspective view showing a method for manufacturing the wavelength conversion member of FIG. 3A. 3B is a schematic plan view showing a method for manufacturing the wavelength conversion member of FIG. 3A. 7B is a schematic cross-sectional view taken along line VIIB-VIIB in FIG. 7A. 3B is a schematic plan view showing another method for manufacturing the wavelength conversion member of FIG. 3A according to the present invention. FIG. FIG. 6 is a schematic cross-sectional view taken along line VIID-VIID in FIG. 7C. 4B is a schematic plan view showing a method for manufacturing the wavelength conversion member of FIG. 4A. 8B is a schematic cross-sectional view taken along line VIIIB-VIIIB in FIG. 8A. 3B is a schematic plan view showing another method for manufacturing the wavelength conversion member of FIG. 3A. 9B is a schematic cross-sectional view taken along line IXB-IXB of FIG. 9A. 3B is a schematic plan view showing another method for manufacturing the wavelength conversion member of FIG. 3A. 10B is a schematic cross-sectional view taken along line XB-XB in FIG. 10A. 3B is a schematic cross-sectional view showing another method for manufacturing the wavelength conversion member of FIG. 3A. 3B is a schematic cross-sectional view showing another method for manufacturing the wavelength conversion member of FIG. 3A.

The following describes embodiments of the present invention with reference to the drawings as appropriate. However, the embodiments described below are intended to embody the technical ideas of the present invention, and unless otherwise specified, the present invention is not limited to the following. The sizes and positional relationships of the components shown in each drawing may be exaggerated to clarify the explanation. Furthermore, components in each embodiment that use the same names as those in other embodiments represent the same or corresponding components. Unless otherwise specified, such components may use the materials, sizes, etc. listed in the other embodiments.

First embodiment: Wavelength conversion member 10
1A and 1B, the wavelength conversion member 10 of the first embodiment includes a heat dissipation component 11, a wavelength conversion layer 14, and a screw 15. The heat dissipation component 11 has a screw hole 11a. The wavelength conversion layer 14 has a heat conductive portion 12 and a phosphor-containing portion 13. The heat conductive portion 12 is disposed on the heat dissipation component 11. The phosphor-containing portion 13 is disposed in contact with the heat conductive portion 12. The wavelength conversion layer 14 has a through hole 14a. The screw 15 is fitted into the through hole 14a and the screw hole 11a, and the wavelength conversion layer 14 is screwed and fixed to the heat dissipation component 11 by the screw 15.
In this way, the wavelength conversion member 10 has a configuration in which the heat conductive portion 12 and the phosphor-containing portion 13 are mechanically fixed to the heat dissipation component 11 by screws. This reduces the possibility that the thermal expansion of each of these members affects the fixing strength even if there is a difference in thermal expansion coefficient between the heat conductive portion 12, the phosphor-containing portion 13, and the heat dissipation component 11. If these members are fixed by an adhesive, a bonding layer, or the like, when the phosphor-containing portion 13 is repeatedly irradiated with light to generate heat and cooled by stopping the irradiation, the difference in thermal expansion coefficient between the members may cause cracks in the adhesive, the bonding layer, or the like. Since the members are fixed by screws rather than by an adhesive, a bonding layer, or the like, there is no decrease in the fixing strength due to such cracks, and the possibility that the phosphor-containing portion 13 will detach from the heat conductive portion 12 can be reduced. Furthermore, since there is no separate member such as an adhesive or a bonding layer between the phosphor-containing portion 13 and the heat conductive portion 12, the heat generated in the phosphor-containing portion 13 when light is irradiated to the phosphor-containing portion 13 can be dissipated directly to the heat conductive portion 12, and therefore efficient heat dissipation can be expected. As a result, it is possible to obtain a highly reliable wavelength conversion member 10.

[Wavelength conversion layer 14]
The wavelength conversion layer 14 is composed of a heat conductive portion 12 and a phosphor-containing portion 13. The wavelength conversion layer 14 may include other members. The wavelength conversion function of the wavelength conversion layer 14 is achieved with the phosphor-containing portion 13, so the heat conductive portion 12 may be omitted. From the viewpoint of improving heat dissipation, it is preferable that the wavelength conversion layer 14 has not only the phosphor-containing portion 13 but also the heat conductive portion 12 that does not contain phosphor. It is preferable that the heat conductive portion 12 and the phosphor-containing portion 13 are arranged in this order from the side of the heat dissipation component 11 described later, with the heat conductive portion 12 and the phosphor-containing portion 13 being in contact with each other partially or entirely. This can be expected to efficiently dissipate heat.
The wavelength conversion layer 14 is a direct bonding layer or an integrally sintered layer of the heat conductive portion 12 and the phosphor-containing portion 13. Here, the direct bonding layer refers to a layer bonded without using an adhesive, and is formed by various direct bonding methods. The integrally sintered layer refers to a layer in which sintered bodies (ceramics) are integrated together without using an adhesive, and is formed by integrally sintering them.

(Heat conductive portion 12)
The heat conductive portion 12 may be any member that constitutes a part of the wavelength conversion layer 14 and can hold the phosphor-containing portion 13. The heat conductive portion 12 is preferably formed of a heat-resistant material in consideration of the influence of heat generation from the phosphor-containing portion 13. The heat conductive portion 12 is preferably formed of a material that has a small difference in thermal expansion coefficient from the phosphor-containing portion 13. The heat conductive portion 12 is preferably a light-reflective member. This causes the light in the phosphor-containing portion 13 to be reflected by the heat conductive portion 12, and it is possible to prevent the main light from the phosphor-containing portion 13 from reaching the heat dissipation component 11. As a result, it is possible to suppress a decrease in luminous efficiency due to light absorption by the heat dissipation component 11.
The thermally conductive portion 12 can be formed of, for example, metal, ceramic, resin, glass, or a composite material containing one or more of these. In particular, the thermally conductive portion 12 is preferably formed of ceramics such as aluminum oxide, aluminum nitride, silicon nitride, silicon carbide, etc. This allows the use of a material that is easy to form integrally with the phosphor-containing portion 13 and has a relatively high thermal conductivity. The thermally conductive portion 12 may be made of a light-reflective material by, for example, adding a material having a higher refractive index than the ceramic material as an additive. Examples of high-refractive-index materials include those having a refractive index of, for example, 1.8 or more or 2.0 or more. Examples of materials having a refractive index difference with the ceramic material include those having a refractive index of, for example, 0.4 or more or 0.7 or more. Examples of additive materials include voids filled with a gas such as air, titanium oxide, aluminum oxide, zirconium oxide, yttrium oxide, zirconium oxide, boron nitride, lutetium oxide, lanthanum oxide, etc.
Furthermore, when the thermally conductive portion 12 is made of ceramics, the light reflectivity and thermal conductivity can be controlled by adjusting the density of the voids present therein. The density of the voids can be adjusted by changing the degree of compression of the ceramic material. For example, it is preferable that there are relatively few voids below the phosphor-containing portion 13 in order to ensure heat dissipation. The voids can be recognized, for example, by observing the cross section of the object under observation with a scanning electron microscope (SEM).

The thermally conductive portion 12 may have any shape that can hold the phosphor-containing portion 13. The shape of the thermally conductive portion 12 may be a plate-like member with a flat surface. For example, the thermally conductive portion 12 may have an upper surface, a lower surface, and a side surface, and these upper and lower surfaces are parallel to each other. By having the parallel upper and lower surfaces, it becomes easy to attach the wavelength conversion member 10 to other members that constitute the wavelength conversion member 10. As a result, it is easy to attach the wavelength conversion member 10 to a light emitting device, etc., and the accuracy of light extraction, etc. can be improved. The side surface of the thermally conductive portion 12 may be perpendicular to the upper surface, may be inclined so as to spread outward or inward, or may be a curved surface.
The planar shape of the thermally conductive portion 12 can be appropriately set depending on the shape of the light emitting device to which it is applied, and may be various shapes such as a circle, an ellipse, or a polygon such as a rectangle. The size of the thermally conductive portion 12 in the planar shape may be, for example, 1 mm to 50 mm on one side or in diameter.
Considering the strength, the thickness of the thermally conductive portion 12 is, for example, 0.2 mm or more. In order to suppress an increase in cost and thickness, the thickness of the thermally conductive portion 12 is preferably 2.0 mm or less.
As shown in FIG. 1B, the upper surface of the thermally conductive portion 12 may coincide with the lower surface of a phosphor-containing portion 13, which will be described later.

(Phosphor-containing portion 13)
The phosphor-containing portion 13 contains a phosphor. The phosphor-containing portion 13 is preferably made of ceramics containing a phosphor or a single crystal of a phosphor. With such a configuration, the heat resistance is higher than that of a member using a resin containing a phosphor, and therefore the phosphor-containing portion 13 can be used for a relatively long period of time for laser light irradiation. For example, when ceramics is used as the phosphor-containing portion 13, the phosphor and a light-transmitting material such as aluminum oxide (Al ₂ O ₃ , melting point: about 1900° C. to 2100° C.) may be sintered. The content of the phosphor may be 0.05% by volume to 50% by volume with respect to the total volume of the ceramic. Alternatively, the ceramic may be sintered and substantially made of only the phosphor.
The phosphor contained in the phosphor-containing portion 13 may be any phosphor known in the art. Examples include cerium-activated yttrium aluminum garnet (YAG) phosphor, cerium-activated lutetium aluminum garnet (LAG) phosphor, europium-activated silicate phosphor, α-sialon phosphor, β-sialon phosphor, KSF phosphor, etc. Among them, it is preferable to use a YAG phosphor, which is a phosphor with good heat resistance.

The phosphor-containing portion 13 may have any shape as long as the whole or a part of it can be placed on the heat conducting portion 12. The shape of the phosphor-containing portion 13 may be a plate-like member with a flat surface. For example, the phosphor-containing portion 13 may have an upper surface, a lower surface, and a side surface, and the upper and lower surfaces are parallel to each other. By having parallel upper and lower surfaces, the distribution of the wavelength-converted light in the wavelength conversion member 10 can be made closer to uniform. It is preferable that the entire lower surface of the phosphor-containing portion 13 is disposed on the upper surface of the heat conducting portion 12. This allows the heat of the phosphor-containing portion 13 to be efficiently released to the heat conducting portion 12. The side surface of the phosphor-containing portion 13 may be perpendicular to the upper surface, or may be inclined so as to spread outward or inward.
The planar shape of the phosphor-containing portion 13 can be appropriately set depending on the shape of the light-emitting device to which it is applied, and various shapes such as a circle, an ellipse, or a polygon such as a rectangle can be mentioned. The phosphor-containing portion 13 can have a planar shape that is the same as, smaller or larger than, the heat-conducting portion 12. The size of the phosphor-containing portion 13, for example, in the planar shape, can be 0.4 mm to 55 mm on one side or in diameter. In particular, it is preferable that the phosphor-containing portion 13 has an outer edge that coincides with the outer edge of the heat-conducting portion 12 in a planar view, or is disposed inside the outer edge of the heat-conducting portion 12. This allows the entire lower surface of the phosphor-containing portion 13 to be disposed on the upper surface of the heat-conducting portion 12.
Considering the physical strength, the thickness of the phosphor-containing portion 13 is, for example, 0.2 mm or more. In order to suppress an increase in cost and height and to achieve an appropriate degree of wavelength conversion, the thickness of the phosphor-containing portion 13 is preferably 5.0 mm or less.

(Through hole 14a)
The wavelength conversion layer 14 has a through hole 14a. In FIGS. 1A and 1B, the through hole 14a is formed in both the heat conductive portion 12 and the phosphor-containing portion 13. The through hole 14a is formed from the upper surface to the lower surface of the wavelength conversion layer 14, that is, from the upper surface of the phosphor-containing portion 13 to the lower surface of the heat conductive portion 12, in the region where the phosphor-containing portion 13 and the heat conductive portion 12 are arranged. The through hole 14a may have the same cross-sectional shape from top to bottom, or may have a shape that expands or widens in its entire length or part toward the top, bottom, top and bottom, or center. The through hole 14a is preferably a shape ( FIG. 1B , etc.) that expands toward the upper surface near the upper surface of the wavelength conversion layer 14 so that, for example, the screw head of the screw 15 described later is accommodated and the upper surface of the wavelength conversion layer 14 and the screw head are flush with each other or the screw head is accommodated on the heat dissipation component 11 side rather than the upper surface of the wavelength conversion layer 14. This makes it possible to prevent the screw head from interfering with light extraction.
The number of through holes 14a can be set arbitrarily, and may be one, but is preferably two or more. The shape of through holes 14a may be various shapes such as a circle, an ellipse, a polygon such as a rectangle, or a shape combining these shapes in a plan view. The position of through holes 14a may be arranged at any position in a plan view. In particular, it is preferable to arrange them outside the region to be irradiated with light in wavelength conversion layer 14. The region to be irradiated with light is a region to be irradiated with excitation light that excites the phosphor in phosphor-containing portion 13. The region to be irradiated with light may be a size slightly larger than the size of the excitation light to be actually irradiated. The region to be irradiated with light may be appropriately set depending on the type of light source, and the planar shape may be various shapes such as a circle, an ellipse, or a polygon such as a rectangle. The region to be irradiated with light in wavelength conversion layer 14 may be, for example, a region of 0.4 mm to 2 mm x 0.4 mm to 2 mm, in other words, a region of 0.16 mm ² to 4 mm ² . Specifically, when the light to be wavelength converted is laser light, the size of one side or diameter can be 100 μm to 3000 μm. The through-holes 14a can be disposed, for example, on the outer periphery of the wavelength conversion layer 14. The outer periphery of the wavelength conversion layer 14 refers to a region that does not include the region to be irradiated with the above-mentioned light, and can be, for example, a region up to 20 mm from the outer edge of the wavelength conversion layer 14.

The size of the through hole 14a can be appropriately set depending on the size of the screw used, the size and thickness of the wavelength conversion layer 14, etc. The size of the through hole 14a can be, for example, 0.1 mm to 16 mm on one side or diameter of the through hole 14a. The through hole 14a may have a side or diameter of 12 mm or less. As shown in FIG. 1C, the through hole 14a may have a size such that a gap is provided between the through hole 14a and the screw 15 described later so that the buffer material 16 can be embedded therein. By disposing the buffer material 16 in this manner, the wavelength conversion layer 14 can be more firmly fixed to the heat dissipation component 11 while reducing or avoiding damage to the wavelength conversion layer due to the stress of the screw fastening. The buffer material 16 may be made of a material softer than the screw 15 and the wavelength conversion layer 14, for example, a resin.
The through holes 14a can be formed by a method known in the art, such as sandblasting, etching, cutting, laser processing, etc. In addition, when the wavelength conversion layer 14 is made of ceramics, the through holes can be easily formed into a desired shape and size by forming a material before firing, such as a green sheet.

[Heat dissipation component 11]
The heat dissipation component 11 is disposed below the wavelength conversion layer 14, that is, on the lower surface side of the heat conduction section 12. Moreover, the heat dissipation component 11 is preferably disposed in contact with the lower surface of the heat conduction section 12. Such contact allows the heat of the phosphor-containing section 13 and the heat conduction section 12 to be dissipated directly and efficiently to the heat dissipation component 11.
The heat dissipation component 11 may be made of a material having a better thermal conductivity than the material constituting the heat conduction portion 12. The heat dissipation component 11 may be made of a light-transmitting material, a light-reflecting material, or the like. Here, the term "light-transmitting" refers to a material that can transmit the light irradiated to the wavelength conversion member 10, and examples of such materials include a material having a light transmittance of 70% or more, 80% or more, or 90% or more. When the heat conduction portion 12 and the heat dissipation component 11 are made of a light-transmitting material, it is possible to extract the excitation light from the heat dissipation component side. The heat dissipation component 11 may be made of, for example, a metal, a ceramic, or a single crystal. Considering the high thermal conductivity, examples of the metal include copper, aluminum, a copper alloy, and an aluminum alloy. When the heat dissipation component 11 is used as a light reflecting member, silver or the like may be used to increase the reflectance. A ceramic insulating material such as aluminum nitride, which has a small thermal expansion coefficient and a high thermal conductivity, may be used. In this case, the surface may be coated with a metal material such as silver to increase the reflectance. Examples of single crystals include sapphire. The heat dissipation component 11 may have a laminated structure of two or more layers, as shown in FIG. 1D. This allows light reflectivity, heat dissipation, and the like to be ensured by combining various materials. In FIG. 1D, a metal substrate 112 made mainly of a metal such as copper is arranged on the upper layer, that is, the side that contacts the lower surface of the heat conductive portion 12, and a heat sink 111 is arranged on the lower layer. Examples of heat sinks include those formed mainly of metals such as copper, aluminum, copper alloys, and aluminum alloys. A heat sink alone may be used as the heat dissipation component 11.

The heat dissipation component 11 may have the same shape and size as the wavelength conversion layer 14, in particular the outer edge of the lower surface of the heat conduction part 12, in plan view, or may be slightly larger or smaller. In particular, it is preferable that the entire outer edge of the heat dissipation component 11 is disposed outside the outer edge of the lower surface of the heat conduction part 12 in plan view.
The thickness of the heat dissipation component 11 is, for example, 0.1 mm to 5 mm, and preferably 0.3 mm to 3 mm. This ensures the strength of the heat dissipation component 11 and improves the heat dissipation performance. In addition, the volume of the heat dissipation component 11 is preferably larger than the volume of the wavelength conversion layer 14. This allows the heat of the wavelength conversion layer 14 to be efficiently dissipated to the heat dissipation component 11.
The heat dissipation component 11 has a screw hole 11a. The screw hole 11a is for fixing the wavelength conversion layer 14 with a screw, and the number, size, position, etc. of the screw hole 11a can be appropriately set depending on the number, size, position, etc. of the through holes 14a of the wavelength conversion layer 14. In other words, when the wavelength conversion layer 14 is arranged at an appropriate position on the heat dissipation component 11, the same size and number of the through holes 14a of the wavelength conversion layer 14 can be arranged at a position overlapping with the through holes 14a of the wavelength conversion layer 14. When a buffer material 16 is embedded between the through holes 14a and the screws 15, it is preferable that the size of the screw hole 11a is smaller than the size of the through holes 14a. This allows the screw hole 11a and the screw 15 to be more reliably engaged. For example, no buffer material is arranged between the screw hole 11a and the screw 15. The depth of the screw hole 11a may be set to a level that allows the screw to be inserted into the through holes 14a and the screw hole 11a and fixed, and can be appropriately set depending on the length of the screw, etc.
When the wavelength conversion layer 14 is screwed to the heat dissipation component 11, a soft material that transfers heat, such as thermal grease, may be provided between the wavelength conversion layer 14 and the heat dissipation component 11. Filling the gap with such a material can further improve heat dissipation. Furthermore, providing a soft material can reduce the possibility that the wavelength conversion layer 14 or the like will crack due to thermal shock.

[Screw 15]
The screws 15 are used to fix the wavelength conversion layer 14 to the heat dissipation component 11 and may be any type that can fix the wavelength conversion layer 14 to the heat dissipation component 11 .
The length of the screw 15 can be appropriately set within a range longer than the total length of the through hole 14 a in the wavelength conversion layer 14 and shorter than the sum of this total length and the depth of the screw hole 11 a in the heat dissipation component 11 .
The thickness of the screw 15 can be set according to the size of the through hole 14a in the wavelength conversion layer 14 in a plan view and the size of the screw hole 11a in a plan view.
By fitting such a screw 15 into the through hole 14a and the screw hole 11a, the wavelength conversion layer 14 can be screwed and fixed to the heat dissipation component 11. It is considered that such fixing can reduce the possibility of the wavelength conversion layer 14 peeling off from the heat dissipation component 11 compared to a method of fixing the wavelength conversion layer and the heat dissipation component using a bonding layer such as eutectic bonding, in which a eutectic metal is melted and bonded. Even if there is a difference in thermal expansion coefficient between the wavelength conversion layer 14 and the heat dissipation component 11, and even if the wavelength conversion layer 14 is subjected to a thermal cycle by irradiating light to the wavelength conversion layer 14 and stopping the irradiation of light, the possibility of the wavelength conversion layer 14 detaching from the heat dissipation component 11 can be reduced. As a result, the heat generated in the wavelength conversion layer can be directly dissipated to the heat dissipation component, and therefore a wavelength conversion member 10 with efficient heat dissipation and high reliability can be provided.
The screw 15 can be made of a metal such as SUS, a ceramic such as aluminum nitride, etc. When there is a possibility that the screw 15 is irradiated with light, the screw 15 may be made of a material that does not easily absorb the light irradiated to the wavelength conversion layer 14, for example.

Second embodiment: Wavelength conversion member 20
The wavelength conversion member 20 of the second embodiment includes, for example, a heat dissipation component 11, a wavelength conversion layer 24, and a screw 15, as shown in FIGS. 2A and 2B.
The wavelength conversion layer 24 has a heat conductive section 12 and a phosphor-containing section 23. The phosphor-containing section 23 is arranged such that the entire lower surface thereof is in contact with the heat conductive section 12, and the entire outer edge of the phosphor-containing section 23 is arranged inside the outer edge of the heat conductive section 12 in a plan view. The phosphor-containing section 23 can be arranged with a planar area that is 50% to 90% of the planar area of the heat conductive section 12. In this case, a part of the upper surface of the wavelength conversion layer 24 coincides with the entire lower surface of the phosphor-containing section 23.
The wavelength conversion layer 24 has through holes 24a, but the through holes 24a are arranged only in those parts of the heat conduction section 12 where the phosphor-containing sections 23 are not arranged.
Other than the above-mentioned configuration, the wavelength conversion member may have the same configuration as the wavelength conversion member of the above-mentioned embodiment 1. Therefore, it has the same effects as the wavelength conversion member of the above-mentioned embodiment 1.
Furthermore, since no through-holes for screwing are provided in the phosphor-containing portion 23, no load is applied to the phosphor-containing portion 23 due to screwing. This reduces the possibility of damaging the phosphor-containing portion 23. Furthermore, since no through-holes are provided in the phosphor-containing portion 23, the uniformity of the light extracted from the phosphor-containing portion 23 can be improved.
Note that a plurality of phosphor-containing portions 23 may be arranged in one wavelength conversion member 20 .

Third embodiment: Wavelength conversion member 30
A wavelength conversion member 30 of the third embodiment includes a heat dissipation component 11, a wavelength conversion layer 34, and a screw 15, as shown in, for example, FIGS. 3A and 3B.
The wavelength conversion layer 34 has a heat conductive portion 32 and a phosphor-containing portion 33. As shown in FIG. 3A, in a plan view, the entire outer edge of the phosphor-containing portion 33 is disposed inside the outer edge of the heat conductive portion 32. As shown in FIG. 3B, in a cross-sectional view, the phosphor-containing portion 33 is disposed so that the entire lower surface thereof is in contact with the heat conductive portion 32, and the lower surface and side surface of the phosphor-containing portion 33 are surrounded by the heat conductive portion 32 so as to be in contact with each other. In a plan view, the phosphor-containing portion 33 can be disposed with a planar area of 50% to 90% of the planar area of the heat conductive portion 32. The upper surface of the phosphor-containing portion 33 may be disposed below or above the upper surface of the heat conductive portion 32, but here, the upper surface of the phosphor-containing portion 33 and the upper surface of the heat conductive portion 32 are coincident. That is, the upper surface of the phosphor-containing portion 33 is flush with the upper surface of the heat conductive portion 32. The wavelength conversion layer 34 having such a shape can be obtained by integrally forming the phosphor-containing portion 33 and the heat conductive portion 32. In this case, for example, the maximum thickness of the heat conductive portion 32 can be 10 mm or less, and the minimum thickness can be 0.1 mm or more. In addition to the case where the upper surfaces are positioned strictly on the same plane, the fact that the upper surfaces are flush or coincident with each other also includes a state in which the upper surfaces are shifted within a range of 10% or less of the thickness of the phosphor-containing portion 33. The same applies to other embodiments.
The wavelength conversion layer 34 has through holes 34a, but the through holes 34a are disposed only in the heat conductive portion 32 where the phosphor-containing portion 33 is not disposed.
As described above, when the thermally conductive portion 32 is made of ceramics, the light reflectivity and heat conductivity can be controlled by adjusting the density of the voids present therein. The density of the voids present in the thermally conductive portion 32 may be made different depending on the location. For example, the porosity (density of the voids) of the portion below the phosphor-containing portion 33 can be made lower than the porosity of the portions to the sides of the phosphor-containing portion 33. This improves the heat dissipation below the phosphor-containing portion 33 and improves the light reflectivity to the sides of the phosphor-containing portion 33.
Other than the above-mentioned configuration, the wavelength conversion member may have the same configuration as the wavelength conversion member of the above-mentioned embodiment 2. Therefore, the wavelength conversion member has the same effects as the wavelength conversion member of the above-mentioned embodiment 2.
Furthermore, if the heat conductive section 32 has light reflectivity, the emission of light in the lateral direction from the phosphor-containing section 33 can be reduced or prevented, thereby improving the efficiency of light extraction from the top surface of the phosphor-containing section 33.

Fourth embodiment: Wavelength conversion member 40
The wavelength conversion member 40 of the fourth embodiment includes, for example, a heat dissipation component 11, a wavelength conversion layer 44, and a screw 15, as shown in FIGS. 4A and 4B.
The wavelength conversion layer 44 has a heat conductive portion 42 and a phosphor-containing portion 43. A plurality of phosphor-containing portions 43 are arranged in one wavelength conversion member 40. Each phosphor-containing portion 43 may have the same area as the area of the region irradiated with light, or may have an area larger or smaller than the area. In addition, the planar shape of each phosphor-containing portion 43 can be various shapes as described above. The heat conductive portion 42 is arranged to surround each phosphor-containing portion 43. Therefore, in a plan view, the entire outer edge of each phosphor-containing portion 43 is arranged inside the outer edge of the heat conductive portion 42. As shown in FIG. 4B, in a cross-sectional view, the heat conductive portion 42 is arranged to surround the side surface of each phosphor-containing portion 43.
The upper surface of the phosphor-containing portion 43 may be disposed above or below the upper surface of the heat conductive portion 42, but in this embodiment, the upper surface of the phosphor-containing portion 43 is flush with the upper surface of the heat conductive portion 42. In this case, the maximum thickness of the heat conductive portion 42 can be 10 mm or less, and the minimum thickness can be 0.2 mm or more.
The wavelength conversion layer 44 has through holes 44a, but the through holes 44a are disposed only in the heat conductive portion 42 where the phosphor-containing portion 43 is not disposed.
Other than the above-mentioned configuration, the wavelength conversion member 40 of the fourth embodiment can have the same configuration as the wavelength conversion member of the above-mentioned embodiment 3. Therefore, it has the same effect as the wavelength conversion member of the above-mentioned embodiment 3. In addition, since the wavelength conversion member 40 of the fourth embodiment has a plurality of phosphor-containing portions 43 arranged in one wavelength conversion member 40, it is possible to cause one or more of these phosphor-containing portions 43 to emit light independently.

Embodiment 5: Light-emitting device 50
A light emitting device 50 of the fifth embodiment includes, for example, a wavelength conversion member 10 and a light source 60 that irradiates the phosphor-containing portion of the wavelength conversion member 10 with light.
In such a light emitting device 50, the light emitted from the light source 60 and passing through the wavelength conversion member 10 can be emitted to the outside through an optical member 52 that can change the light to a desired light distribution, etc. Also, a spatial light modulator 53 may be disposed between the light source 60 and the wavelength conversion member 10 in order to make the light emitted from the light source 60, for example, laser light, incident at a specific angle.
With this configuration, the light from the light source 60 is incident on the wavelength conversion member 10 in almost all of its major portions as designed. Then, a part of the light is wavelength-converted by the phosphor in the phosphor-containing portion of the wavelength conversion member 10, and another part is reflected, and these lights are directed to the outside. This wavelength-converted light and non-wavelength-converted light are mixed together, and can be emitted to the outside as, for example, white light. Then, the heat dissipation component arranged below the wavelength conversion layer effectively dissipates heat caused by light irradiation, and the function as a light-emitting device can be maintained for a long period of time.

The light source 60 may be a light emitting diode (LED) or a semiconductor laser element, or one in which these are enclosed in a package or the like, and is preferably a semiconductor laser device. By using a semiconductor laser device, the area of the light incident surface of the phosphor-containing portion can be made smaller than when an LED is used, and the size of the light emitting device 50 can be reduced. In addition, the heat dissipation effect can be efficiently ensured by the heat conductive portion and the heat dissipation component.
As the spatial light modulator 53, a device known in the art, such as a micro electro mechanical system (MEMS), can be used.

Sixth embodiment: Method for manufacturing a wavelength conversion member A method for manufacturing a wavelength conversion member of the sixth embodiment includes the steps of forming a wavelength conversion layer by integrally sintering a heat conductive portion and a phosphor-containing portion in contact with the heat conductive portion, forming a through hole in the wavelength conversion layer, preparing a heat dissipation component having a screw hole, and fitting screws into the through hole and the screw hole to screw the wavelength conversion layer to the heat dissipation component.
By using this manufacturing method, it is possible to easily manufacture a wavelength conversion member that reduces the possibility of the wavelength conversion member peeling off from the heat dissipation component and can efficiently dissipate heat from the wavelength conversion member to the heat dissipation component, while reducing manufacturing costs.

The process of forming the wavelength conversion layer preferably includes the steps of preparing the phosphor-containing portion having an upper surface, a lower surface and a side surface, forming a molded body containing a powder of an inorganic material on the sides and below the phosphor-containing portion so as to surround the phosphor-containing portion, and sintering the molded body integrally.
In this step, a through hole may be formed in the integrated body in contact with the thermally conductive portion before sintering, and then the integrated body may be sintered.
By this method for manufacturing a wavelength conversion member, the heat conductive portion and the phosphor-containing portion are integrally formed without using an adhesive or a bonding layer, and can be mechanically fixed to a heat dissipation component by screws. Therefore, even if there is a difference in the thermal expansion coefficient of each member, it is difficult to affect the fixing strength. In other words, it is possible to reduce the possibility that the phosphor-containing portion will detach from the heat conductive portion. In addition, since the heat generated by the phosphor-containing portion when light is irradiated to the phosphor-containing portion can be directly dissipated to the heat conductive portion, efficient heat dissipation can be expected. As a result, it is possible to obtain a wavelength conversion member with high reliability. Each process will be described in detail below.

[Preparation of Wavelength Conversion Layer]
First, a wavelength conversion layer is prepared.
The wavelength conversion layer can be formed by sintering a molded product of a phosphor-containing part made of a ceramic or other molded body and a powdered material for the thermal conductive part, or by sintering a molded product of a phosphor-containing part made of a powdered material and a thermal conductive part made of a molded body.
The molded body can be molded using a slip casting method, a doctor blade method (sheet molding method), a dry molding method, or the like. For sintering, a spark plasma sintering method (SPS method) or a hot pressing sintering method (HPS method) or the like can be used. As these methods, for example, the method described in JP 2017-149929 A or the like can be used. In addition, for manufacturing the phosphor-containing portion, CIP (Cold Isostatic Pressing), HIP (Hot Isostatic Pressing), or the like can be used.

For example, the wavelength conversion layer can be manufactured by the following method or a method according to the description of JP 2019-9406 A.
(1) A manufacturing method including the steps of preparing a fluorescent member containing a phosphor and having a plurality of convex portions on the front side, preparing a powdered light reflecting member, and arranging the powdered light reflecting member between the plurality of convex portions of the fluorescent member, sintering them to obtain a sintered body (ceramics) in which the fluorescent member and the light reflecting member are integrally formed, and removing a part of the sintered body from at least one of the front side and the back side of the fluorescent member. Note that a slurry containing a powdered light reflecting member may be used instead of the powdered light reflecting member.
(2) A manufacturing method comprising the steps of preparing a light-reflecting member having a plurality of recesses on its front surface, preparing a powdered fluorescent material containing a phosphor, arranging the powdered fluorescent material in the plurality of recesses in the light-reflecting member, sintering the resulting material to obtain a sintered body in which the light-reflecting member and the fluorescent material are integrally formed, and removing at least a portion of the sintered body from the back surface side of the light-reflecting member.
(3) A manufacturing method including the steps of preparing a light reflecting member having a plurality of through holes penetrating a first main surface and a second main surface opposite to each other, preparing a powdered fluorescent member containing a phosphor, and disposing the powdered fluorescent member in the plurality of through holes, sintering them to obtain a sintered body in which the light reflecting member and the fluorescent member are integrally formed, and removing a portion of the sintered body from at least one of the front side and the back side of the fluorescent member. The sintered body here means a body in which the fluorescent member and the support are integrally sintered. The sintering can be performed at a temperature range of 1100°C to 1800°C. After obtaining the sintered body, it may be heat-treated at a temperature range of 1000°C to 1500°C. Methods for removing a portion of the sintered body include, for example, grinding, polishing, chemical mechanical polishing, and the like.

The wavelength conversion layer may be manufactured by a method in which a plurality of phosphor-containing parts are first prepared, and then a heat-conducting part surrounding the phosphor-containing parts is formed by sintering. Specifically, when manufacturing the wavelength conversion layer 34 shown in FIG. 3A, a plurality of phosphor-containing parts 33 having an upper surface, a lower surface, and a side surface are first prepared as shown in FIG. 6. The phosphor-containing parts 33 may be formed from a material known in the art. By preparing a plurality of parts, a plurality of wavelength conversion layers can be manufactured by one sintering, thereby improving mass productivity.
Next, as shown in FIGS. 7A and 7B, a support 36 is prepared in which one recess 31 is provided and a plurality of protrusions 35 corresponding to through holes are arranged in a matrix within the recess 31.
Then, a phosphor-containing portion 33 is disposed in the recess 31, and powder 322 made of an inorganic material for forming a thermally conductive portion is disposed on the sides and above the phosphor-containing portion 33 so as to surround the phosphor-containing portion 33, thereby forming a molded body. The phosphor-containing portions 33 are disposed, for example, between a pair of protrusions 35. The powder 322 is disposed so as to surround the side surfaces of the protrusions 35 as well.
Thereafter, the compact is integrally sintered by the method described above.
7A and 7B , the heat conductive portion 32 is divided together with the support 36 along the dashed line X to obtain one wavelength conversion layer 34. In this way, as shown in FIG. 3A , the heat conductive portion 32 is arranged around the phosphor-containing portion 33, and the wavelength conversion layer 34 having a desired size and the through hole 34a can be obtained.
The division may be performed by using a method known in the art, such as scribing, dicing, etc. Furthermore, the division is performed, for example, after the obtained sintered body (ceramics) is removed from the support 36.

In addition, when obtaining one wavelength conversion layer, instead of the support 36 shown in Figures 7A and 7B, a support 36A similar to the support 36 shown in Figures 7A and 7B may be used, except that a pair of protrusions 35 is provided in one recess 31 of a size corresponding to one wavelength conversion layer, as shown in Figures 7C and 7D.
4A and 4B, a support 46 shown in Fig. 8A and 8B may be used instead of the support 36 shown in Fig. 7A and 7B. By using this support 46, a plurality of phosphor-containing portions 43 (e.g., eight of them) are arranged at equal intervals between a pair of protrusions 45 in one recess 41, and powder 422 made of an inorganic material for forming a heat conductive portion is arranged and sintered, and then divided, a wavelength conversion layer 44 of a desired size in which heat conductive portions 42 are arranged around each phosphor-containing portion 43 as shown in Fig. 4A and 4B can be obtained.

As another method for manufacturing the wavelength conversion layer 34 shown in FIG. 3A, first, a plurality of phosphor-containing portions 33 having an upper surface, a lower surface, and a side surface are prepared as shown in FIG.
9A and 9B, the phosphor-containing portions 33 are arranged in a matrix on a flat support member 80 and temporarily fixed. In consideration of workability, it is preferable to use the support member 80, but it is not necessary to use the support member 80. In order to utilize the slip casting method (sludge casting method), for example, gypsum can be used as the support member 80.
10A and 10B, a molded body 38 containing a light reflecting powder made of an inorganic material is formed so that the phosphor-containing portion 33 surrounds the sides and the top of the phosphor-containing portion 33. The molded body 38 can be molded using a slip casting method, a doctor blade method (sheet molding method), a dry molding method, or the like. Before forming the molded body 38, a frame may be formed in an area that will be the outer periphery of the molded body 38, and the molded body 38 may be filled into this frame and molded.
Thereafter, the support member 80 is removed, and optionally, in order to remove organic matter and the like contained in the compact 38, the compact 38 is heated at a temperature lower than the sintering temperature and degreased.
Next, the molded body 38 is sintered, for example, in an air atmosphere, so that the phosphor-containing portion 33 and the heat conductive portion 32 are integrally sintered.
By arbitrarily polishing the heat conductive portion 32 from the heat conductive portion 32 side to make it thinner, dividing it at the heat conductive portion 32, and forming a through hole in the heat conductive portion 32 using, for example, a drill, etc., it is possible to obtain a wavelength conversion layer 34 of a desired size in which the heat conductive portion 32 is arranged around the phosphor-containing portion 33, as shown in Figures 3A and 3B.

[Preparation of heat dissipation component 11]
11A, a flat heat dissipation component having a screw hole 11a is prepared as the heat dissipation component 11. The screw hole 11a can be formed by a method known in the art depending on the material of the heat dissipation component. For example, a method using a drill or the like can be mentioned.

[Screw fastening]
As shown in FIG. 11B , the wavelength conversion layer 34 is placed on the heat dissipation component 11, the through holes 34a of the wavelength conversion layer 34 are aligned with the screw holes 11a of the heat dissipation component 11, screws 15 are inserted into the through holes 34a and the screw holes 11a, and the wavelength conversion layer 34 is screwed and fixed to the heat dissipation component 11.
When screwing, thermal grease or the like may be placed between the heat dissipation component 11 and the wavelength conversion layer 34 .
This allows the entire lower surface of the heat conductive portion 32 to be in contact with the heat dissipation component 11, making it possible to manufacture a wavelength conversion member 30 that can efficiently dissipate heat.
As shown in FIG. 1C , after the screw 15 is fitted into the screw hole 11 a, a buffer material 16 may be injected into the gap between the screw 15 and the wavelength conversion layer 14 .

10, 20, 30, 40 Wavelength conversion member 11 Heat dissipation component 11a Screw hole 12, 32, 42 Heat conduction portion 13, 23, 33, 43 Phosphor-containing portion 14, 24, 34, 44 Wavelength conversion layer 14a, 24a, 34a, 44a Through hole 15 Screw 16 Cushioning material 31 Recess 35, 45 Protrusion 36, 36A Support 38 Molded body 41 Recess 46 Support 50 Light-emitting device 52 Optical member 53 Spatial light modulator 60 Light source 80 Support member 111 Heat sink 112 Metal substrate 322, 422 Powder

Claims (8)

A heat dissipation component having a screw hole;
a wavelength conversion layer disposed on the heat dissipation component, the wavelength conversion layer having a heat conductive portion and a phosphor-containing portion in contact with the heat conductive portion, the wavelength conversion layer having a through hole;
a screw;
the screw has a screw head, the screw head being flush with an upper surface of the wavelength conversion layer or being located closer to the heat dissipation component than the upper surface;
the through hole has a shape that is expanded or widened toward an upper surface of the wavelength conversion layer over an entire length or a part of the length;
the wavelength conversion layer is fixed to the heat dissipation component by the screw fitted into the through hole and the screw hole,
The through hole has a gap between it and the screw, and a buffer material made of resin is filled in the gap . The wavelength conversion member according to claim 1, wherein the wavelength conversion layer is a direct bonded layer or an integrally sintered layer with the heat conductive portion and the phosphor-containing portion. The wavelength conversion member according to claim 1 or 2, wherein the heat conductive portion is made of ceramics. the wavelength conversion layer includes, in order from the heat dissipation component side, the heat conduction portion and the phosphor-containing portion,
The wavelength conversion member according to claim 1 , wherein the through-hole is disposed in the phosphor-containing portion and the heat conductive portion. The wavelength conversion member according to any one of claims 1 to 3, wherein, in a plan view, the outer edge of the phosphor-containing portion is disposed inside the outer edge of the heat conductive portion, and the through-hole is disposed only in the heat conductive portion. The wavelength conversion member according to claim 5, wherein the phosphor-containing portion and the heat-conducting portion each have an upper surface, a lower surface, and a side surface, and the upper surface of the phosphor-containing portion is flush with the upper surface of the heat-conducting portion. The wavelength conversion member according to any one of claims 1 to 6, wherein the heat conductive portion is a light reflective material. A wavelength conversion member according to any one of claims 1 to 7 ,
a light source that irradiates the phosphor-containing portion of the wavelength conversion member with light.