Wavelength conversion member and light source device

Abstract

This wavelength conversion member is characterized by being provided with: a phosphor that emits fluorescence from excitation light, and that has an incident surface on which the excitation light is incident, and a back surface positioned on the opposite side from the incident surface; and a reflective film that is disposed on the rear surface side of the phosphor and that is composed of a metal layer and particles contained in the interior of the metal layer, the particles having a higher melting point than the metal constituting the metal layer, the reflective film having a first surface that faces the rear surface of the phosphor, and a second surface that is located on the opposite side of the first surface, the second surface side contains more particles than the first surface side.

Description

Technical Field

[0001] The present invention relates to a wavelength conversion member and a light source device. Background Art

[0002] In the past, there is known a wavelength conversion component that converts the excitation light irradiated from the light source into fluorescence of other wavelengths. Generally, the wavelength conversion component includes: a phosphor for converting the wavelength of the excitation light; and a reflective film arranged on the side of the phosphor opposite to the side irradiated with the excitation light. For example, Patent Document 1 discloses a wavelength conversion component, which includes: a converter as a phosphor and a covering layer containing metal as a reflective film. In the wavelength conversion component, the covering layer containing metal includes glass in a metal such as silver, thereby improving the wettability of silver and the phosphor.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application No. 2016-534396 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] In Patent Document 1, when a metal-containing coating is baked on a converter, the glass contained in the coating is heated to a temperature at which the glass melts. The molten glass can flow, and therefore sometimes induces aggregation of the glass and unevenly exists at the phosphor interface, thereby reacting with the phosphor. As a result, sometimes the bonding strength between the phosphor and the reflective film is reduced, or the reflectivity of the reflective film is reduced.

[0008] The present invention has been made to solve at least a part of the above problems, and an object of the present invention is to provide a wavelength conversion member and a light source device that can improve the bonding strength between a phosphor and a reflective film and suppress a decrease in the reflectivity of the reflective film.

[0009] Solutions for solving problems

[0010] The present invention has been made to solve at least a part of the above-mentioned problems, and can be implemented in the following aspects.

[0011] (1) According to one aspect of the present invention, there is provided a wavelength conversion member. The wavelength conversion member is characterized in that it comprises: a phosphor that emits fluorescence when excited light is emitted, and has an incident surface on which the excitation light is incident and a back surface located on the opposite side of the incident surface; and a reflective film that is disposed on the back surface side of the phosphor and is composed of a metal layer and particles contained in the metal layer, wherein the melting point of the particles is higher than the melting point of the metal constituting the metal layer, and the reflective film has: a first surface that is opposite to the back surface of the phosphor, and a second surface that is located on the opposite side of the first surface, wherein the second surface contains more particles than the first surface.

[0012] According to this structure, the melting point of the particles is higher than the melting point of the metal constituting the metal layer, and such particles are contained more on the second side than on the first side. When manufacturing such a wavelength conversion member, in the process of forming a film as a reflective film on the back side of the phosphor, if the material (including the metal constituting the metal layer and the particles) that will become the basis of the reflective film is heated to a temperature above the melting point of the metal constituting the metal layer and below the melting point of the particles, the metal constituting the metal layer melts, and thus, in a state where the adhesion of the metal layer to the phosphor is improved, a reflective film can be formed on the back side of the phosphor. Thus, the bonding strength between the phosphor and the reflective film can be improved. In addition, when the reflective film is formed on the back side of the phosphor, the particles contained on the second side are not melted and become more than the first side. Therefore, the surface tension acting on each particle and the molten metal is contrary to the surface tension acting on the phosphor and the molten metal, so the force of the metal on the phosphor to aggregate is weakened, and the aggregation of the molten metal layer can be suppressed. That is, the reflective film can be easily extended along the phosphor, so from this aspect, the bonding strength between the phosphor and the reflective film can also be improved. Furthermore, when the reflective film is formed on the back side of the phosphor, the particles contained on the first side are not melted and become less than the particles contained on the second side. Therefore, it is possible to suppress the reduction in reflectivity of the reflective film caused by the reaction between the melted particles and the back side of the phosphor, the accumulation of a large number of particles on the first side, and the reduction in the area of ​​the metal layer exposed on the first side. Therefore, according to this configuration, a wavelength conversion member can be provided that improves the bonding strength between the phosphor and the reflective film and suppresses the reduction in reflectivity of the reflective film.

[0013] (2) In the wavelength conversion member of the above aspect, the specific gravity of the particles may be smaller than the specific gravity of the metal layer.

[0014] According to this configuration, particles can be easily unevenly present on the upper side in the direction of gravity in the interior of the metal layer that has melted when manufacturing the wavelength conversion member. Therefore, when a reflective film is formed on the back side of the phosphor, the heated metal layer and particles are formed as a reflective film on the back side of the phosphor facing the upper side in the direction of gravity, thereby making it easy to make particles unevenly present on the second side. Therefore, a wavelength conversion member containing more particles on the second side than on the first side can be provided with good precision.

[0015] (3) In the wavelength conversion member of the above aspect, when the length between the first surface and the second surface is set to the thickness of the reflective film, the particle size of the particles may be less than or equal to half the thickness of the reflective film.

[0016] If the particle size of the particles increases, the ratio of the thickness of the metal layer to the thickness of the reflective film becomes relatively smaller, and the possibility of forming a through hole in the metal layer becomes higher. In other words, the possibility of forming a portion without a metal layer in the reflective film when viewed from above becomes higher. According to this configuration, the possibility of forming a through hole in the metal layer can be reduced, and the reduction in the reflective performance of the reflective film can be suppressed.

[0017] (4) In the wavelength conversion member of the above aspect, the material constituting the particles may include a material contained in the phosphor.

[0018] According to this structure, the difference between the thermal expansion coefficient of the particles and the thermal expansion coefficient of the phosphor can be reduced. Therefore, the temperature range in which the particles do not thermally expand excessively overlaps with the temperature range in which the phosphor does not thermally expand excessively. Therefore, in the heating when manufacturing the wavelength conversion component and the heating based on the thermal conversion of the incident excitation light, the allowable temperature range in which the particles and the phosphor do not thermally expand excessively can be widely set. That is, according to this structure, it is not easy to produce cracks, deformation, peeling of the phosphor and the reflective film, and other undesirable conditions caused by excessive thermal expansion of the phosphor and particles. In addition, it is also possible to suppress the composition changes caused by the reaction at the interface where the phosphor contacts the particles.

[0019] (5) The wavelength conversion member of the above aspect may further include a heat dissipation member that is disposed on the second surface side of the reflective film and dissipates heat generated by the fluorescent body to the outside.

[0020] According to this configuration, the heat generated by converting a portion of the excitation light incident on the phosphor can be dissipated to the outside of the wavelength conversion member by the heat dissipation member. Thus, thermal quenching caused by a decrease in the amount of fluorescence from the phosphor due to a temperature rise can be suppressed. Therefore, the decrease in the amount of fluorescence emitted by the phosphor can be suppressed.

[0021] (6) According to another aspect of the present invention, there is provided a light source device comprising: the wavelength conversion member according to the above aspect; and a light source for irradiating the incident surface with the excitation light.

[0022] According to this configuration, the excitation light irradiated from the light source to the phosphor is emitted from the phosphor as fluorescence. In addition, the reflective film contains more particles on the second side than on the first side, thereby suppressing the reduction in reflectivity. Therefore, it is possible to suppress the reduction in the intensity of the excitation light incident on the phosphor that passes through the phosphor and the fluorescence emitted from the phosphor toward the back side, and to reflect these excitation light and fluorescence to the phosphor side. In addition, by providing such a reflective film, the reduction in reflectivity of the reflective film is suppressed, and a light source device with improved bonding strength between the phosphor and the reflective film can be provided.

[0023] It should be noted that the present invention can be implemented in various forms, for example, it can be implemented in the form of a wavelength conversion member, a light source device, a light emitting device, lighting, and devices including the same, and methods for manufacturing the same. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is an explanatory diagram schematically showing a cross-sectional structure of a wavelength conversion member.

[0025] Figure 2 The present invention is a flow chart of a method for manufacturing a wavelength conversion component.

[0026] Figure 3 It is an explanatory diagram showing the manufacturing process of the wavelength conversion member. DETAILED DESCRIPTION

[0027] Figure 1 This is an explanatory diagram schematically showing the cross-sectional structure of a wavelength conversion member 1 according to one embodiment of the present invention. The wavelength conversion member 1 is a member that converts the excitation light L1 irradiated by a light source 50 such as a light emitting diode (LED) or a semiconductor laser (LD) into a fluorescent light L2 having a wavelength different from the light L1 and emits the fluorescent light. The wavelength conversion member 1 is used in various optical instruments such as headlights, lighting, and slide projectors. Figure 1 The wavelength conversion member 1 shown is a part of the light source device 100. The light source device 100 includes a light source 50 for irradiating the excitation light L1 in addition to the wavelength conversion member 1. The wavelength conversion member 1 includes a phosphor 10, a reflective film 20, a bonding layer 30, and a heat dissipation member 40.

[0028] The phosphor 10 emits fluorescence L2 using the irradiated excitation light L1. The phosphor 10 has an incident surface 10f and a back surface 10b. The incident surface 10f is the surface on which the excitation light L1 is incident. The back surface 10b is the surface located on the opposite side of the incident surface 10f. The ceramic sintered body constituting the phosphor 10 includes: a fluorescent phase having fluorescent grains as the main body and a translucent phase having translucent grains as the main body. The grains of the translucent phase are Al2O3 (aluminum oxide). On the other hand, the grains of the fluorescent phase are preferably A3B5O 12 :Ce shown in the composition (so-called garnet structure). "A3B5O 12 :Ce" means Ce is solid dissolved in A3B5O 12 In this embodiment, a part of element A is replaced by Ce.

[0029] A3B5 12 : The element A and the element B in Ce are each composed of at least one element selected from the following element group.

[0030] Element A: Lanthanide elements other than Sc, Y, and Ce (optionally including Gd as element A)

[0031] Element B: Al (optionally, Gd is also contained as element B)

[0032] By using a ceramic sintered body as the phosphor 10, light is scattered at the interface between the fluorescent phase and the light-transmitting phase, and the angular dependence of the light color can be reduced. Thus, the color homogeneity can be improved. It should be noted that the material of the phosphor 10 is not limited to the above materials.

[0033] The reflective film 20 is arranged on the back surface 10b side of the phosphor 10, and reflects the excitation light L1 incident on the phosphor 10 that passes through the phosphor 10 and the fluorescence L2 emitted from the phosphor 10 that is directed toward the back surface 10b side toward the phosphor 10. The reflective film 20 has a first surface 20f and a second surface 20b. The first surface 20f is a surface of the phosphor 10 that is opposite to the back surface 10b. The second surface 20b is a surface located on the opposite side of the first surface 20f.

[0034] The reflective film 20 is composed of a metal layer 21 and particles 22. Examples of the metal constituting the metal layer 21 include silver (Ag), platinum (Pt), aluminum (Al), and silver alloys. In the present embodiment, the metal constituting the metal layer 21 is silver (Ag). The particles 22 are contained in the metal layer 21. Examples of the particles 22 include ceramic particles such as Al2O3, YAG, TiO2, Y2O3, SiO2, Cr2O3, Nb2O5, and Ta2O5, and metal particles such as Ni, W, Mo, Cr, and Nb. In the present embodiment, the particles 22 are Al2O3. That is, the material constituting the particles 22 is Al2O3, which is the same as the crystal grains of the light-transmitting phase of the phosphor 10. Therefore, the material constituting the particles 22 includes the material contained in the phosphor 10. The ratio of the volume occupied by the particles 22 in the reflective film 20 to the volume occupied by the metal layer 21 is preferably 0.1 to 20.0%. In addition, when the length between the first surface 20f and the second surface 20b is set as the thickness of the reflective film 20, the thickness is preferably 1 to 100 μm, and the particle size of the particles 22 is preferably 0.5 to 50 μm. In the present embodiment, the particle size of the particles 22 is less than half the thickness of the reflective film 20. It should be noted that the value of the particle size is the average value of the particle sizes of any 100 particles 22 observed in the cross-sectional image of the particles 22 based on a scanning electron microscope (SEM).

[0035] In the reflective film 20, the melting point of the particles 22 is higher than the melting point of the metal constituting the metal layer 21. It should be noted that the melting point of Al2O3 constituting the particles 22 of the present embodiment is 2072° C., and the melting point of silver (Ag) constituting the metal layer 21 is 961.8° C. In addition, the specific gravity of the particles 22 is smaller than the specific gravity of the metal layer 21.

[0036] like Figure 1 As shown in FIG. 1 , the second surface 20b contains more particles 22 than the first surface 20f. The distribution of the particles 22 is confirmed by analyzing the cross-sectional image based on a scanning electron microscope (SEM). Specifically, the distribution of the particles 22 is confirmed by analyzing the cross-sectional image of the phosphor 10 orthogonal to the incident surface 10f (e.g. Figure 1In the cross-sectional image shown in FIG. 2 , the distribution of the particles 22 near the first surface 20f is compared with the distribution of the particles 22 near the second surface 20b to confirm. The distribution of the particles 22 near the first surface 20f is represented by a value obtained by dividing the cross-sectional area of ​​the particles 22 existing in the range of depth from the first surface 20f to 10% of the thickness of the reflective film 20 (the length between the first surface 20f and the second surface 20b) by the cross-sectional area of ​​the metal layer 21 existing in the same range. On the other hand, the distribution of the particles 22 near the second surface 20b is similarly represented by a value obtained by dividing the cross-sectional area of ​​the particles 22 existing in the range of depth from the second surface 20b to 10% of the thickness of the reflective film 20 by the cross-sectional area of ​​the metal layer 21 existing in the same range. It should be noted that Figure 1 In order to schematically show the distribution of the particles 22 in the reflective film 20, the particles 22 contained in the first surface 20f and the particles 22 contained in the second surface 20b may be distributed at unequal intervals, and the portion near the center between the first surface 20f and the second surface 20b in the reflective film 20 may also contain particles 22. Of course, the ratio of the particles 22 contained in the first surface 20f to the particles 22 contained in the second surface 20b may not be 1 / 2. Figure 1 ratio shown.

[0037] The bonding layer 30 is disposed between the reflective film 20 and the heat dissipation member 40 described later, and is used to bond the reflective film 20 and the heat dissipation member 40. The bonding layer 30 is formed of AuSn solder containing gold (Au) and tin (Sn). It should be noted that the bonding layer 30 is not limited to AuSn solder, and may also be solder such as Sn-Pb solder, Sn-Ag-Cu solder, Sn-Zn-Bi solder, Sn-Cu solder, Sn-Ag-In-Bi solder, etc. In addition, for example, fine powders such as silver (Ag) and copper (Cu) may be sintered to form the bonding layer 30.

[0038] The heat dissipation member 40 is disposed on the second surface 20b side of the reflective film 20, and dissipates the heat generated in the phosphor 10 to the outside of the wavelength conversion member 1. In the present embodiment, the heat dissipation member 40 is disposed on the surface of the bonding layer 30 that is located on the opposite side of the surface bonded to the reflective film 20. As a material constituting the heat dissipation member 40, copper, copper-molybdenum alloy, copper-tungsten alloy, aluminum, and other materials having a higher thermal conductivity than the phosphor 10 are exemplified. In the present embodiment, the material constituting the heat dissipation member 40 is copper.

[0039] Figure 2 Flow chart of a method for manufacturing the wavelength conversion member 1 . Figure 3 (A) to (D) are explanatory diagrams showing the manufacturing process of the wavelength conversion member 1. In the manufacturing of the wavelength conversion member 1, first, Figure 3As shown in (A), the phosphor 10 is prepared (step S10). Specifically, the phosphor 10 is prepared as follows: a slurry containing a material that is a base for the fluorescent phase and the light-transmitting phase and ethanol is ground and mixed, dried, and then granulated, a binder and water are further added and kneaded to form a molded product, and a molded product made of the molded product is fired to prepare the phosphor 10. Next, as Figure 3 As shown in (B), the first paste 21pf is applied to the back surface 10b of the phosphor 10 (step S20). Specifically, the first paste 21pf is applied to the back surface 10b of the phosphor 10 with the back surface 10b facing upward in the gravity direction. The first paste 21pf is prepared in advance by mixing an acrylic binder and a solvent with the metal powder and particles 22 constituting the metal layer 21.

[0040] Then, if Figure 3 As shown in (C), the second paste 21pb is applied to the surface of the first paste 21pf on the opposite side to the back side 10b (step S30). The second paste 21pb is the same as the first paste 21pf except that it contains more particles 22 than the first paste 21pf. The laminate LM represents a laminate in which the phosphor 10, the first paste 21pf and the second paste 21pb are laminated. Next, the laminate LM is heated at a temperature above the melting point of the metal contained in the first and second pastes 21pf and 21pb and below the melting point of the particles 22, and the first paste 21pf and the second paste 21pb are fused, thereby, as shown in FIG. Figure 3 As shown in (D), the reflective film 20 is formed on the back surface 10b of the phosphor 10 (step S40). It should be noted that when the first paste 21pf and the second paste 21pb are fused, the specific gravity of the particles 22 contained in each paste is smaller than the specific gravity of the metal contained in the same paste, so a part of the particles 22 contained in the first paste 21pf moves to the second paste 21pb side ( Figure 3 (D) is not shown). The movement amount of the particles 22 is adjusted by the heating temperature and the heating time. Then, the reflective film 20 and the heat dissipation member 40 are bonded via the bonding layer 30 (step S50), thereby completing the method for manufacturing the wavelength conversion member 1.

[0041] As described above, according to the wavelength conversion member 1 of the present embodiment, the melting point of the particles 22 is higher than the melting point of the metal constituting the metal layer 21, and such particles 22 are contained more on the second surface 20b side than on the first surface 20f side. When manufacturing such a wavelength conversion member 1, in the process of forming the reflective film 20 on the back surface 10b of the phosphor 10, the material that will form the basis of the reflective film 20 (including the metal constituting the metal layer 21 and the particles 22) is heated to a temperature that is higher than the melting point of the metal constituting the metal layer 21 and lower than the melting point of the particles 22 (equivalent to Figure 2In step S40), the metal constituting the metal layer 21 is melted, so that the reflective film 20 can be formed on the back surface 10b of the phosphor 10 while the adhesion of the metal layer 21 to the phosphor 10 is improved. Thus, the bonding strength between the phosphor 10 and the reflective film 20 can be improved. In addition, when the reflective film 20 is formed on the back surface 10b of the phosphor 10, the particles 22 contained in the second surface 20b side are not melted and become more than the first surface 20f-44 side. Therefore, the surface tension acting on each particle 22 and the molten metal is contrary to the surface tension acting on the phosphor 10 and the molten metal, so the force of the metal to aggregate the phosphor 10 is weakened, and the aggregation of the molten metal layer 21 can be suppressed. That is, the reflective film 20 can be extended along the phosphor 10, so from this aspect, the bonding strength between the phosphor 10 and the reflective film 20 can also be improved. Furthermore, when the reflective film 20 is formed on the back surface 10b of the phosphor 10, the particles 22 included on the first surface 20f side are not melted, and become less than the second surface 20b side, similarly to the particles 22 included on the second surface 20b side. Therefore, it is possible to suppress the decrease in reflectivity of the reflective film 20 caused by the reaction of the melted particles 22 with the back surface 10b of the phosphor 10, the accumulation of a large number of particles 22 on the first surface 20f side, and the reduction in the area of ​​the metal layer 21 exposed on the first surface 20f. Therefore, according to the wavelength conversion member 1 of the present embodiment, it is possible to provide a wavelength conversion member 1 in which the bonding strength between the phosphor 10 and the reflective film 20 is improved and the decrease in reflectivity of the reflective film 20 is suppressed.

[0042] In the wavelength conversion member 1 of the present embodiment, the particles 22 are Al 2 O 3 . Al 2 O 3 has high light transmittance, so the particles 22 can be prevented from absorbing the excitation light and fluorescence reaching the reflective film 20 , thereby preventing the reflectivity of the reflective film 20 from decreasing.

[0043] In addition, in the wavelength conversion member 1 of the present embodiment, the specific gravity of the particles 22 is smaller than that of the metal layer 21. Therefore, when manufacturing the wavelength conversion member 1, the particles 22 can be unevenly distributed inside the molten metal layer 21 on the upper side in the gravity direction. Therefore, when the back surface 10b of the phosphor 10 is formed as the reflective film 20, the heated metal layer 21 and the particles 22 are formed as the reflective film 20 on the back surface 10b of the phosphor 10 facing the upper side in the gravity direction (see Figure 3 ), so that the particles 22 can be unevenly present on the second surface 20b side. As a result, the wavelength conversion member 1 containing more particles 22 on the second surface 20b side than on the first surface 20f side can be provided with good accuracy.

[0044] In addition, in the wavelength conversion member 1 of the present embodiment, the particle size of the particles 22 is less than half the thickness of the reflective film 20. If the particle size of the particles 22 increases, the ratio of the thickness of the reflective film 20 occupied by the metal layer 21 becomes relatively smaller, and the possibility of forming through holes in the metal layer 21 increases. In other words, the possibility of forming a portion without the metal layer 21 in the reflective film 20 in a plan view increases. Therefore, in the wavelength conversion member 1, the possibility of forming through holes in the metal layer 21 can be reduced, and the reduction in the reflective performance of the reflective film can be suppressed.

[0045] In addition, in the wavelength conversion member 1 of the present embodiment, the material constituting the particles 22 includes the material contained in the phosphor 10. Therefore, the difference between the thermal expansion coefficient of the particles 22 and the thermal expansion coefficient of the phosphor 10 can be reduced. Therefore, the temperature range in which the particles 22 do not thermally expand excessively overlaps with the temperature range in which the phosphor 10 does not thermally expand excessively, and therefore, in the heating during the manufacture of the wavelength conversion member 1 and the heating based on the thermal conversion of the incident excitation light L1, the allowable temperature range in which the particles 22 and the phosphor 10 do not thermally expand excessively can be widely set. That is, in the wavelength conversion member 1, it is not easy to produce undesirable conditions caused by excessive thermal expansion of the phosphor 10 and the particles 22, such as cracks, deformation, and peeling of the phosphor and the reflective film. In addition, it is also possible to suppress the composition change caused by the reaction at the interface where the phosphor 10 and the particles 22 contact.

[0046] In addition, the wavelength conversion member 1 of the present embodiment is provided with a heat dissipation member 40 for dissipating heat generated in the phosphor 10 to the outside. Therefore, the heat generated by converting a part of the excitation light L1 incident on the phosphor 10 can be dissipated to the outside of the wavelength conversion member 1 by the heat dissipation member 40. Thus, it is possible to suppress thermal quenching in which the amount of fluorescence from the phosphor 10 decreases due to a temperature rise. Therefore, it is possible to suppress a decrease in the amount of fluorescence emitted from the phosphor 10.

[0047] In addition, according to the light source device 100 of the present embodiment, the excitation light L1 irradiated from the light source 50 to the phosphor 10 is emitted as the fluorescence L2 by the phosphor 10. In addition, the reflective film 20 contains more particles on the second surface 20b side than on the first surface 20f side, thereby suppressing the reduction of reflectivity. Therefore, it is possible to suppress the reduction of the intensity of each of the excitation light L1 incident on the phosphor 10 that passes through the phosphor 10 and the fluorescence L2 emitted from the phosphor 10 toward the back side, and these excitation light and fluorescence can be reflected to the phosphor 10 side. In addition, by providing such a reflective film 20, in the light source device 100, in addition to suppressing the reduction of the reflectivity of the reflective film 20, the bonding strength between the phosphor 10 and the reflective film 20 is also improved.

[0048] <Modification of this embodiment>

[0049] The present invention is not limited to the above-described embodiment, and can be implemented in various forms without departing from the gist of the present invention. For example, the following modifications are also possible.

[0050] In the above embodiment, the reflective film 20 is as follows Figure 1 As shown in FIG. 1 , the reflective film 20 is arranged in direct contact with the back surface 10b of the phosphor 10, but the present invention is not limited thereto. For example, the reflective film 20 only needs to be arranged on the back surface 10b side of the phosphor 10, and other structures may be arranged between the reflective film 20 and the phosphor 10. As other structures, an adhesive film and a high reflective film are exemplified. When such a structure is arranged between the reflective film 20 and the phosphor 10, the reflective film 20 may be formed as a film with improved adhesion to the phosphor 10.

[0051] As described in the above embodiment, the particles 22 are not limited to Al2O3. For example, the particles 22 may be YAG. When the particles 22 made of YAG are included in the reflective film 20, they absorb the excitation light reaching the reflective film 20 side and the blue light included in the fluorescence and can emit yellow light.

[0052] In the above-mentioned embodiment, the material constituting the particles 22 is Al2O3 which is the same as the crystal grains of the light-transmitting phase of the phosphor 10, but the present invention is not limited thereto. The material constituting the particles 22 only needs to include at least a part of the material contained in the phosphor 10, and may further include a material different from the material contained in the phosphor 10. In addition, when the material contained in the phosphor 10 is not included in the material constituting the particles 22, the material constituting the particles 22 preferably includes a material having a thermal expansion coefficient equivalent to that of the material contained in the phosphor 10.

[0053] In the above embodiment, the particles 22 are composed of Al2O3 and the metal layer 21 is composed of silver (Ag), but the present invention is not limited thereto. For example, the particles 22 and the metal layer 21 may be composed of a plurality of materials, respectively. In addition, in such a case, the melting point of the particles 22 is higher than the melting point of the metal constituting the metal layer 21, which means that the melting point of the material with the lowest melting point among the materials constituting the particles 22 is higher than the melting point of the material with the highest melting point among the plurality of materials constituting the metal layer 21.

[0054] In the above embodiment, the reflective film 20 is formed by two pastes (first and second pastes 21pf and 21pb) having different particle contents, but the present invention is not limited thereto. For example, the reflective film 20 can be formed by only one paste or three or more pastes as long as it is a paste containing the metal constituting the metal layer 21 and the particles 22 having a smaller specific gravity than the metal.

[0055] The above is an explanation of the present invention based on the implementation modes and variations, but the implementation modes of the above-mentioned embodiments are used to facilitate the understanding of the present invention and do not limit the present invention. The present invention can be changed and improved without departing from its main purpose and claims, and the present invention includes its equivalents. In addition, its technical features can be appropriately deleted as long as they are not described as essential in this specification.

[0056] The present invention can also be implemented in the following manner.

[0057] [Application Example 1]

[0058] A wavelength conversion component, characterized by comprising:

[0059] A phosphor that emits fluorescence in response to excitation light and has an incident surface on which the excitation light is incident and a back surface located on the opposite side of the incident surface; and

[0060] a reflective film disposed on the back side of the phosphor and composed of a metal layer and particles contained in the metal layer,

[0061] The melting point of the particles is higher than the melting point of the metal constituting the metal layer.

[0062] The aforementioned reflective film has:

[0063] a first surface opposite to the back surface of the phosphor, and

[0064] a second surface located on the opposite side of the first surface,

[0065] The second surface contains more of the particles than the first surface.

[0066] [Application Example 2]

[0067] The wavelength conversion component according to Application Example 1 is characterized in that:

[0068] The specific gravity of the aforementioned particles is smaller than the specific gravity of the aforementioned metal layer.

[0069] [Application Example 3]

[0070] The wavelength conversion member according to Application Example 1 or Application Example 2 is characterized in that:

[0071] When the length between the first surface and the second surface is defined as the thickness of the reflective film, the particle diameter of the particles is less than or equal to half of the thickness of the reflective film.

[0072] [Application Example 4]

[0073] The wavelength conversion member according to any one of Application Examples 1 to 3 is characterized in that

[0074] The material constituting the aforementioned particles includes the material contained in the aforementioned phosphor.

[0075] [Application Example 5]

[0076] The wavelength conversion member according to any one of Application Examples 1 to 4 is characterized in that

[0077] A heat dissipation member is further provided, which is disposed on the second surface side of the reflective film and dissipates heat generated by the fluorescent body to the outside.

[0078] [Application Example 6]

[0079] A light source device, characterized by comprising:

[0080] The wavelength conversion member according to any one of Application Examples 1 to 5, and

[0081] A light source irradiates the incident surface with the excitation light.

[0082] Description of Reference Numerals

[0083] 1…Wavelength conversion component

[0084] 10…Phosphor

[0085] 10f…Incident surface

[0086] 10b…Back

[0087] 20…Reflective film

[0088] 20f…Page 1

[0089] 20b…Side 2

[0090] 21…Metal layer

[0091] 21pf…1st paste

[0092] 21pb…2nd paste

[0093] 22…granules

[0094] 30…Joint layer

[0095] 40…Heat dissipation component

[0096] 50…Light source

[0097] 100…Light source device.

Claims

1. A wavelength conversion component, characterized in that: have: a phosphor that emits fluorescence in response to excitation light and has an incident surface on which the excitation light is incident and a back surface located on the opposite side of the incident surface; and, a reflective film disposed on the back side of the phosphor and composed of a metal layer and particles contained in the metal layer, The melting point of the particles is higher than the melting point of the metal constituting the metal layer, The reflective film has: a first surface opposite to the back surface of the phosphor, and a second surface located on the opposite side of the first surface, The particles are contained in larger amounts on the second surface than on the first surface.

2. The wavelength conversion component according to claim 1, characterized in that: The specific gravity of the particles is smaller than that of the metal layer.

3. The wavelength conversion component according to claim 2, characterized in that: When the length between the first surface and the second surface is defined as the thickness of the reflective film, the particle size of the particles is less than or equal to half the thickness of the reflective film.

4. The wavelength conversion component according to claim 3, characterized in that: The material constituting the particles includes a material contained in the phosphor.

5. The wavelength conversion component according to claim 4, characterized in that: A heat dissipation member is further provided, which is disposed on the second surface side of the reflective film and dissipates heat generated by the fluorescent body to the outside.

6. A light source device, characterized in that: have: The wavelength conversion member according to any one of claims 1 to 5, and A light source irradiates the incident surface with the excitation light.

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