Wavelength conversion device, method for manufacturing wavelength conversion device, light source device, and projector

Abstract

The invention provides a wavelength conversion device, a manufacturing method thereof, a light source device, and a projector, which can improve the bonding strength and cooling efficiency of a wavelength conversion layer at the same time. This wavelength conversion device is provided with: a wavelength conversion layer which has a first surface on which light is incident and a second surface opposite the first surface, and which converts the incident light; a substrate disposed on the second surface side of the wavelength conversion layer; and a bonding layer that bonds the substrate and the wavelength conversion layer, the bonding layer having a first layer facing the substrate and a second layer disposed between the first layer and the wavelength conversion layer, and the porosity of the first layer being higher than the porosity of the second layer.

Description

Technical Field

[0001] The present invention relates to a wavelength conversion device, a method for manufacturing the wavelength conversion device, a light source device and a projector. Background Art

[0002] In recent years, there are lighting devices that use fluorescence as illumination light. For example, Patent Document 1 below discloses a lighting device that includes a light source that emits laser light and a wavelength conversion device that emits fluorescence when the laser light is incident. In this lighting device, the wavelength conversion device includes: a phosphor layer; a heat dissipation substrate that is provided on the side of the phosphor layer opposite to the side on which the excitation light is incident; and a bonding layer that bonds the phosphor layer to the heat dissipation substrate.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2011-129354

[0004] In the above-mentioned lighting device, the expansion coefficients of the phosphor layer and the heat dissipation substrate are different from each other. Therefore, when the phosphor layer generates heat, the phosphor layer may be peeled off or damaged due to the thermal stress caused by the difference in thermal expansion coefficients. In addition, it is also considered to improve the bonding strength of the phosphor layer by relieving the thermal stress by using a bonding layer with a gap inside, but there is a new problem that the thermal conductivity of the bonding layer is reduced due to the gap, and the cooling efficiency of the phosphor layer is reduced. Summary of the invention

[0005] In order to solve the above-mentioned problems, according to a first embodiment of the present invention, there is provided a wavelength conversion device, which comprises: a wavelength conversion layer, which has a first surface on which light is incident and a second surface opposite to the first surface, and converts the incident light; a substrate, which is arranged on the second surface side of the wavelength conversion layer; and a bonding layer, which bonds the substrate to the wavelength conversion layer, and the bonding layer comprises: a first metal layer, which is opposite to the substrate; and a second metal layer, which is arranged between the first metal layer and the wavelength conversion layer, and the porosity of the first metal layer is higher than the porosity of the second metal layer.

[0006] According to a second aspect of the present invention, there is provided a light source device including: the wavelength conversion device according to the first aspect; and a light emitting element that emits the light toward the wavelength conversion device.

[0007] According to a third aspect of the present invention, a projector is provided, comprising: a light source device according to the second aspect; a light modulation device that modulates light emitted from the light source device based on image information; and a projection optical device that projects the light emitted from the modulation device.

[0008] According to a fourth aspect of the present invention, a method for manufacturing a wavelength conversion device is provided, wherein the wavelength conversion device comprises a wavelength conversion layer, a substrate, and a bonding layer bonding the substrate to the wavelength conversion layer, wherein the bonding layer comprises a first metal layer opposite to the substrate, and a second metal layer having a higher porosity than the first metal layer and arranged between the first metal layer and the wavelength conversion layer, and the method for manufacturing the wavelength conversion device comprises the following steps: a first step of arranging a first metal material on the substrate; a second step of arranging a second metal material having a smaller particle size than the first metal material on the wavelength conversion layer; and a third step of forming the first metal layer by sintering the first metal material and forming the second metal layer by sintering the second metal material, thereby serving as the bonding layer.

[0009] According to a fifth aspect of the present invention, a method for manufacturing a wavelength conversion device is provided, wherein the wavelength conversion device comprises a wavelength conversion layer, a substrate, and a bonding layer bonding the substrate to the wavelength conversion layer, wherein the bonding layer comprises a first metal layer opposite to the substrate, and a second metal layer having a higher porosity than the first metal layer and arranged between the first metal layer and the wavelength conversion layer, and the method for manufacturing the wavelength conversion device comprises the following steps: a first step of arranging a first metal material on the substrate; a second step of arranging a second metal material on the wavelength conversion layer; and a third step of forming the first metal layer by sintering the first metal material, and forming the second metal layer by sintering the second metal material at a sintering temperature higher than the sintering temperature of the first metal material, thereby serving as the bonding layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is a diagram showing a schematic configuration of a projector according to the first embodiment.

[0011] Figure 2 It is a diagram showing a schematic structure of a lighting device.

[0012] Figure 3 It is a cross-sectional view showing the main structure of the wavelength conversion device.

[0013] Figure 4 It is an image showing the main structure of the bonding layer.

[0014] Figure 5A The figures respectively show a part of the manufacturing process of the wavelength conversion device.

[0015] Figure 5B The figures respectively show a part of the manufacturing process of the wavelength conversion device.

[0016] Figure 5CThe figures respectively show a part of the manufacturing process of the wavelength conversion device.

[0017] Figure 6 It is a cross-sectional view showing the main structure of the wavelength conversion device according to the second embodiment.

[0018] Figure 7 It is a cross-sectional view showing the main structure of the wavelength conversion device according to the third embodiment.

[0019] Description of symbols

[0020] 1: projector; 2A: light source device; 4B, 4G, 4R: light modulation device; 6: projection optical system; 40, 140, 240: wavelength conversion device; 40: phosphor layer (wavelength conversion layer); 41: substrate; 42a: first surface; 42b: second surface; 42c: third surface; 45: planarization film; 50, 55, 150, 250: bonding layer; 51, 151, 251: first metal layer; 51A: first metal material; 52, 152, 252: second metal layer; 52A: second metal material; 53: recess; 42b1: periphery; 251b: convex portion (opposing portion); A: first area; AR: incident area; D1, D2: thickness. DETAILED DESCRIPTION

[0021] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0022] In the drawings used in the following description, in order to facilitate understanding of features, characteristic portions may be enlarged for convenience, and the dimensional ratios of the components are not necessarily the same as the actual ones.

[0023] (First Embodiment)

[0024] First, an example of a projector according to this embodiment will be described.

[0025] Figure 1 This is a diagram showing a schematic configuration of a projector according to this embodiment.

[0026] like Figure 1 As shown, the projector 1 of this embodiment is a projection type image display device that displays a color image on a screen SCR. The projector 1 includes an illumination device 2, a color separation optical system 3, a light modulation device 4R, a light modulation device 4G, a light modulation device 4B, a synthesis optical system 5, and a projection optical system 6.

[0027] The color separation optical system 3 separates the illumination light WL into red light LR, green light LG and blue light LB. The color separation optical system 3 generally includes first and second dichroic mirrors 7a and 7b, first, second and third reflecting mirrors 8a, 8b and 8c, and first and second relay lenses 9a and 9b.

[0028] The first dichroic mirror 7a separates the illumination light WL from the illumination device 2 into red light LR and other light (green light LG and blue light LB). The first dichroic mirror 7a transmits the separated red light LR and reflects the other light (green light LG and blue light LB). On the other hand, the second dichroic mirror 7b reflects the green light LG and transmits the blue light LB, thereby separating the other light into the green light LG and the blue light LB.

[0029] The first reflector 8a is arranged in the optical path of the red light LR, and reflects the red light LR transmitted through the first dichroic mirror 7a toward the light modulator 4R. On the other hand, the second reflector 8b and the third reflector 8c are arranged in the optical path of the blue light LB, and guide the blue light LB transmitted through the second dichroic mirror 7b to the light modulator 4B. The green light LG is reflected from the second dichroic mirror 7b toward the light modulator 4G.

[0030] The first relay lens 9a and the second relay lens 9b are arranged in the optical path of the blue light LB after the second dichroic mirror 7b.

[0031] The light modulator 4R modulates the red light LR based on the image information to form image light corresponding to the red light LR. The light modulator 4G modulates the green light LG based on the image information to form image light corresponding to the green light LG. The light modulator 4B modulates the blue light LB based on the image information to form image light corresponding to the blue light LB.

[0032] The light modulators 4R, 4G, and 4B use, for example, projection-type liquid crystal panels, and polarizing plates (not shown) are disposed on the incident side and the emitting side of the liquid crystal panels.

[0033] In addition, field lenses 10R, 10G, and 10B are disposed on the incident sides of the light modulators 4R, 4G, and 4B, respectively. The field lenses 10R, 10G, and 10B collimate the red light LR, green light LG, and blue light LB incident on the light modulators 4R, 4G, and 4B, respectively.

[0034] The image lights from the light modulators 4R, 4G, and 4B are incident on the synthesis optical system 5. The synthesis optical system 5 synthesizes the image lights corresponding to the red light LR, the green light LG, and the blue light LB, respectively, and emits the synthesized image lights toward the projection optical system 6. The synthesis optical system 5 uses, for example, a cross dichroic prism.

[0035] The projection optical system 6 is composed of a projection lens group, and enlarges and projects the image light synthesized by the synthesis optical system 5 toward the screen SCR. Thus, an enlarged color image is displayed on the screen SCR.

[0036] (lighting device)

[0037] Next, the lighting device 2 according to the present embodiment will be described. Figure 2 2 is a diagram showing a schematic structure of the lighting device 2. Figure 2 As shown, the illumination device 2 includes a light source device 2A, an integrating optical system 31, a polarization conversion element 32, and a superimposing lens 33a. In this embodiment, the integrating optical system 31 and the superimposing lens 33a constitute the superimposing optical system 33.

[0038] The light source device 2A has an array light source 21A, a collimating optical system 22, an afocal optical system 23, a first phase difference plate 28a, a polarization separation element 25, a first focusing optical system 26, a wavelength conversion device 40, a second phase difference plate 28b, a second focusing optical system 29 and a diffuse reflection element 30.

[0039] The array light source 21A, the collimating optical system 22, the afocal optical system 23, the first phase difference plate 28a, the polarization separation element 25, the second phase difference plate 28b, the second focusing optical system 29 and the diffuse reflection element 30 are sequentially arranged on the optical axis ax1. On the other hand, the wavelength conversion device 40, the first focusing optical system 26, the polarization separation element 25, the integrator optical system 31, the polarization conversion element 32 and the overlapping lens 33a are sequentially arranged on the illumination optical axis ax2. The optical axis ax1 and the illumination optical axis ax2 are located in the same plane and are perpendicular to each other.

[0040] The array light source 21A has a plurality of semiconductor lasers 211 as solid light sources. The plurality of semiconductor lasers 211 are arranged in an array in a plane perpendicular to the optical axis ax1. The semiconductor laser 211 emits, for example, a blue light BL (for example, a laser with a peak wavelength of 460 nm). The array light source 21A emits a light beam consisting of a plurality of light beams BL. In this embodiment, the array light source 21A is equivalent to the "light source" in the claims.

[0041] The light BL emitted from the array light source 21A enters the collimating optical system 22. The collimating optical system 22 converts the light BL emitted from the array light source 21A into parallel light. The collimating optical system 22 is composed of, for example, a plurality of collimating lenses 22a arranged in an array. The plurality of collimating lenses 22a are arranged corresponding to the plurality of semiconductor lasers 211.

[0042] The light BL that has passed through the collimating optical system 22 enters the afocal optical system 23. The afocal optical system 23 adjusts the beam diameter of the light BL. The afocal optical system 23 is composed of, for example, a convex lens 23a and a concave lens 23b.

[0043] The light BL that has passed through the afocal optical system 23 is incident on the first phase difference plate 28a. The first phase difference plate 28a is, for example, a rotatable 1 / 2 wavelength plate. The light BL emitted from the semiconductor laser 211 is linearly polarized light. By appropriately setting the rotation angle of the first phase difference plate 28a, the light BL that passes through the first phase difference plate 28a can be made into a light that contains an S-polarized light component and a P-polarized light component relative to the polarization separation element 25 at a prescribed ratio. By rotating the first phase difference plate 28a, the ratio of the S-polarized light component to the P-polarized light component can be changed.

[0044] The light beam BL including the S polarized light component and the P polarized light component generated by the first phase difference plate 28a enters the polarization separation element 25. The polarization separation element 25 is constituted by, for example, a polarization beam splitter having wavelength selectivity and forms an angle of 45° with respect to both the optical axis ax1 and the illumination optical axis ax2.

[0045] The polarization separation element 25 has a polarization separation function of separating the light BL into the light BLs of the S polarization component and the light BLp of the P polarization component. Specifically, the polarization separation element 25 reflects the light BLs of the S polarization component and transmits the light BLp of the P polarization component.

[0046] The polarization separation element 25 has a color separation function of transmitting the fluorescence YL having a wavelength band different from that of the light beam BL regardless of its polarization state.

[0047] The S-polarized light beam BLs emitted from the polarization separation element 25 enters the first condensing optical system 26 . The first condensing optical system 26 condenses the light beam BLs toward the wavelength conversion device 40 .

[0048] In the present embodiment, the first condensing optical system 26 is composed of, for example, a first lens 26a and a second lens 26b. The light beam BLs emitted from the first condensing optical system 26 enters the wavelength converter 40 in a condensed state.

[0049] The fluorescence YL generated by the wavelength conversion device 40 is collimated by the first condensing optical system 26 and then enters the polarization separation element 25 . The fluorescence YL is transmitted through the polarization separation element 25 .

[0050] On the other hand, the P-polarized light BLp emitted from the polarization separation element 25 is incident on the second phase difference plate 28b. The second phase difference plate 28b is composed of a 1 / 4 wavelength plate arranged in the optical path between the polarization separation element 25 and the diffuse reflection element 30. Therefore, the P-polarized light BLp emitted from the polarization separation element 25 is converted into, for example, right-handed circularly polarized blue light BLc1 by the second phase difference plate 28b, and then enters the second focusing optical system 29.

[0051] The second condensing optical system 29 is composed of, for example, convex lenses 29 a and 29 b , and allows the blue light BLc1 to be incident on the diffuse reflection element 30 in a condensed state.

[0052] The diffuse reflection element 30 is disposed on the side of the polarization separation element 25 opposite to the fluorescent layer 42, and diffusely reflects the blue light BLc1 emitted from the second condensing optical system 29 toward the polarization separation element 25. As the diffuse reflection element 30, it is preferable to use a diffuse reflection element that performs Lambertian reflection on the blue light BLc1 and does not disturb the polarization state.

[0053] Hereinafter, the light diffusely reflected by the diffuse reflection element 30 is referred to as blue light BLc2. According to the present embodiment, the blue light BLc1 is diffusely reflected to obtain blue light BLc2 having a substantially uniform illuminance distribution. For example, right-handed circularly polarized blue light BLc1 is reflected as left-handed circularly polarized blue light BLc2.

[0054] The blue light BLc2 is converted into parallel light by the second condensing optical system 29 and then enters the second phase difference plate 28 b again.

[0055] The left-handed circularly polarized blue light BLc2 is converted into S-polarized blue light BLs1 by the second phase difference plate 28 b . The S-polarized blue light BLs1 is reflected by the polarization separation element 25 toward the integrator optical system 31 .

[0056] Thus, blue light BLs1 is used as illumination light WL together with fluorescence YL transmitted through polarization separation element 25. That is, blue light BLs1 and fluorescence YL are emitted from polarization separation element 25 in the same direction, generating white illumination light WL in which blue light BLs1 and fluorescence (yellow light) YL are mixed.

[0057] The illumination light WL is emitted toward the integrator optical system 31. The integrator optical system 31 is composed of, for example, a lens array 31a and a lens array 31b. The lens arrays 31a and 31b are formed by arranging a plurality of small lenses in an array.

[0058] The illumination light WL transmitted through the integrator optical system 31 enters the polarization conversion element 32. The polarization conversion element 32 is composed of a polarization separation film and a phase difference plate. The polarization conversion element 32 converts the illumination light WL including the non-polarized fluorescence YL into linearly polarized light.

[0059] The illumination light WL transmitted through the polarization conversion element 32 enters the superimposing lens 33a. The superimposing lens 33a makes the distribution of the illumination intensity of the illumination light WL in the illuminated area uniform in cooperation with the integrator optical system 31. In this way, the illumination device 2 generates the illumination light WL.

[0060] (Wavelength conversion device)

[0061] Figure 3 2 is a cross-sectional view showing a main part structure of the wavelength conversion device 40. Hereinafter, the light BLs emitted from the first condensing optical system 26 and incident on the fluorescent layer 42 is referred to as excitation light BLs.

[0062] like Figure 3 As shown, the wavelength conversion device 40 has a substrate 41, a phosphor layer 42 and a bonding layer 50. The wavelength conversion device 40 of this embodiment has a fixed structure in which the substrate 41 does not rotate. The substrate 41 has a front side 41a opposite to the first focusing optical system 26 and a back side 41b on the opposite side of the front side 41a. The bonding layer 50 bonds the substrate 41 and the phosphor layer 42. The wavelength conversion device 40 of this embodiment also has a reflecting part 43 arranged between the bonding layer 50 and the phosphor layer 42. In this embodiment, the phosphor layer 42 is equivalent to the "wavelength conversion layer" described in the claims.

[0063] In addition, hereinafter, the state of observing the wavelength conversion device 40 along the normal direction of the first surface 42a, which is the incident direction of the excitation light BLs with respect to the phosphor layer 42, that is, the direction in which the main light of the excitation light BLs is incident on the phosphor layer 42, is sometimes referred to as a "top view state".

[0064] As the material of the substrate 41, a material having high thermal conductivity and excellent heat dissipation is preferably used, and examples thereof include metals such as aluminum and copper, and ceramics such as aluminum nitride, aluminum oxide, sapphire, and diamond. In the present embodiment, the substrate 41 is formed of copper.

[0065] Furthermore, by providing a heat dissipation member such as a heat sink on the back surface 41 b of the substrate 41 , the heat dissipation of the substrate 41 can be further improved, thereby suppressing thermal degradation of the phosphor layer 42 .

[0066] In the present embodiment, the phosphor layer 42 is a ceramic phosphor formed by firing phosphor particles. As the phosphor particles constituting the phosphor layer 42, YAG (Yttrium Aluminum Garnet) phosphor containing Ce ions is used.

[0067] In addition, the material forming the phosphor particles may be one kind, or a material formed by mixing particles formed by two or more kinds of materials may be used. As the phosphor layer 42, it is preferable to use a phosphor layer in which phosphor particles are dispersed in an inorganic binder such as alumina, a phosphor layer formed by firing a glass binder as an inorganic material and phosphor particles, etc. In addition, the phosphor layer may be formed by firing phosphor particles without using a binder.

[0068] The phosphor layer 42 is held on the front surface 41a of the substrate 41 via the bonding layer 50 described later. The phosphor layer 42 has: a first surface 42a on which the excitation light BLs is incident and emits the fluorescence YL after the wavelength conversion of the excitation light BLs; and a surface on the side opposite to the first surface 42a, that is, a second surface 42b on which the reflective component 43 and the substrate 41 are provided. That is, in the present embodiment, the substrate 41 is arranged on the side of the phosphor layer 42 opposite to the first surface 42a on which the excitation light BLs is incident. The reflective component 43 reflects the light incident from the phosphor layer 42 toward the first focusing optical system 26.

[0069] The phosphor layer 42 has a light scattering property due to the plurality of pores provided therein. A portion of the plurality of pores is formed on the second surface 42b of the phosphor layer 42, so that the second surface 42b of the phosphor layer 42 has unevenness caused by the pores. The phosphor layer 42 of this embodiment includes a planarization film 45 for planarizing the second surface 42b. As a material of the planarization film 45, an inorganic material having light transmittance, such as SiO2, is used. The planarization film 45 planarizes the second surface 42b by penetrating into the unevenness of the second surface 42b.

[0070] The reflective member 43 of this embodiment is formed by stacking a total reflection layer composed of a multilayer film and a reflection layer composed of a metal material having a high reflectivity such as Ag. The reflective member 43 is formed by sequentially forming a multilayer film and a reflection layer on the planarization film 45 by evaporation or sputtering.

[0071] In this embodiment, the material of the planarization film 45 is the same material (SiO2) as the surface layer of the total reflection layer composed of a multilayer film on the phosphor layer 42 side of the reflector 43. This improves the adhesion between the planarization film 45 and the reflector 43.

[0072] In addition, as described above, the surface of the phosphor layer 42 is made substantially flat by the planarization film 45, so that the multilayer film and the reflective layer constituting the reflective member 43 can be uniformly formed on the second surface 42b of the phosphor layer 42. In addition, the adhesion between the second surface 42b of the phosphor layer 42 and the bonding layer 50 is improved, so the bonding strength of the bonding layer 50 can be further improved.

[0073] In this way, the reflective member 43 reflects a part of the fluorescence YL generated by the fluorescent layer 42 and directed toward the substrate 41 toward the first surface 42 a , and thus the fluorescence YL can be efficiently led out of the fluorescent layer 42 .

[0074] The bonding layer 50 includes a first metal layer 51 and a second metal layer 52. The first metal layer 51 is a metal layer facing the substrate 41. The second metal layer 52 is a metal layer disposed between the first metal layer 51 and the phosphor layer 42.

[0075] The bonding layer 50 has a size covering the entire second surface 42b of the phosphor layer 42. In the present embodiment, the outer periphery of the bonding layer 50 coincides with the outer periphery of the phosphor layer 42 in a plan view. Therefore, the bonding layer 50 is bonded to the peripheral edge 42b1 of the second surface 42b of the phosphor layer 42.

[0076] Here, consider the case where the size of the bonding layer 50 is smaller than the second surface 42b of the phosphor layer 42, and the peripheral edge 42b1 of the second surface 42b is exposed from the bonding layer 50. When the peripheral edge 42b1 of the second surface 42b is exposed from the bonding layer 50, the bonding layer 50 is easily peeled off from the peripheral edge 42b1 of the second surface 42b. In addition, when external force is applied to the peripheral edge 42b1 of the second surface 42b for some reason, defects such as defects and cracks may also occur at the peripheral edge 42b1.

[0077] In contrast, the bonding layer 50 of the present embodiment is bonded to the periphery 42b1 of the second surface 42b of the phosphor layer 42 as described above, thereby suppressing the occurrence of undesirable conditions such as peeling of the bonding layer 50, defects of the periphery 42b1, and cracks. Therefore, the bonding layer 50 of the present embodiment can further improve the bonding reliability between the substrate 41 and the phosphor layer 42.

[0078] The first metal layer 51 is provided on the front surface 41a of the substrate 41. The second metal layer 52 is arranged in the recessed portion 53 provided in the first metal layer 51, and is in contact with the second surface 42b of the phosphor layer 42. The first metal layer 51 is in contact with the second surface 42b of the phosphor layer 42 at a portion other than the recessed portion 53. That is, the first metal layer 51 and the second metal layer 52 are in contact with the second surface 42b of the phosphor layer 42.

[0079] The first metal layer 51 is formed by sintering a first metal material containing at least one of Ag, Au, and Cu. The second metal layer 52 is formed by sintering a second metal material containing at least one of Ag, Au, and Cu. That is, the first metal layer 51 contains at least one of Ag, Au, and Cu, and the second metal layer 52 contains at least one of Ag, Au, and Cu.

[0080] Figure 4 : is an image showing the main structure of the bonding layer 50 .

[0081] like Figure 4 As shown, the first metal layer 51 contains a plurality of pores 51a, and the second metal layer 52 contains a plurality of pores 52a. Here, the ratio of the voids generated by the pores 51a to the entire volume of the first metal layer 51 is referred to as the "void ratio of the first metal layer 51", and the ratio of the voids generated by the pores 52a to the entire volume of the second metal layer 52 is referred to as the "void ratio of the second metal layer 52".

[0082] In the bonding layer 50 of this embodiment, the porosity of the first metal layer 51 is higher than that of the second metal layer 52. Preferably, the porosity of the first metal layer 51 is 30% or more and less than 40%, and the porosity of the second metal layer 52 is 10% or more and less than 30%.

[0083] The first metal layer 51 has a higher porosity than the second metal layer 52, so that the Young's modulus is relatively low and it is easy to deform. Therefore, in the bonding layer 50, the first metal layer 51 can function as a stress relief layer that relieves the thermal stress caused by the difference in thermal expansion coefficient between the substrate 41 and the phosphor layer 42. Therefore, the bonding layer 50 can suppress the occurrence of undesirable conditions such as peeling and damage of the phosphor layer 42 caused by thermal stress through the first metal layer 51.

[0084] In the case of the present embodiment, the second metal layer 52 is arranged in the recessed portion 53 of the first metal layer 51. Therefore, the first metal layer 51 is arranged so as to surround the second metal layer 52. In the case of the present embodiment, in a state of looking down on the bonding layer 50, the first metal layer 51 surrounds the entire periphery of the second metal layer 52. In addition, the shape of the first metal layer 51 in a plan view may be any of a rectangular, circular, or elliptical shape.

[0085] According to this structure, since the first metal layer 51 is arranged in a manner surrounding the second metal layer 52 in the bonding surface of the bonding layer 50, the stress relaxation function achieved by the first metal layer 51 can be evenly generated in the bonding surface. Therefore, the effect of suppressing the peeling and damage of the phosphor layer 42 can be further improved.

[0086] On the other hand, the second metal layer 52 has a lower porosity than the first metal layer 51 , and thus has a relatively higher thermal conductivity, thereby being able to improve the heat dissipation of the phosphor layer 42 .

[0087] In the case of the present embodiment, the second metal layer 52 is arranged corresponding to the incident area AR of the excitation light BLs in the phosphor layer 42. That is, when the first surface 42a of the phosphor layer 42 is observed from the normal direction, the second metal layer 52 is arranged in an area overlapping with at least a portion of the incident area AR. In the case of the present embodiment, the second metal layer 52 is arranged in an area overlapping with the entire incident area AR.

[0088] The phosphor layer 42 generates heat when generating the fluorescence YL, but the incident area AR usually becomes the highest temperature. According to the bonding layer 50 of this embodiment, by configuring the second metal layer 52 with high thermal conductivity in the area corresponding to the incident area AR with the highest temperature in the phosphor layer 42, the heat of the phosphor layer 42 can be efficiently released.

[0089] The second metal layer 52 has a higher Young's modulus than the first metal layer 51 and is less likely to deform. Therefore, the bonding layer 50 can improve the bonding strength by bonding the substrate 41 and the phosphor layer 42 together using the first metal layer 51 .

[0090] In addition, since the first metal layer 51 and the second metal layer 52 of the bonding layer 50 of this embodiment are in contact with the second surface 42b of the phosphor layer 42, the stress relaxation function of the first metal layer 51 and the cooling efficiency improvement function of the second metal layer 52 can be efficiently generated within the bonding surface.

[0091] Here, the region where the first metal layer 51 and the second metal layer 52 in the bonding layer 50 overlap in the incident direction of the excitation light BLs with respect to the phosphor layer 42 is set as the first region A. That is, the bonding layer 50 of the present embodiment includes the first region A where the first metal layer 51 and the second metal layer 52 overlap in the incident direction of the excitation light BLs with respect to the phosphor layer 42.

[0092] Here, the second metal layer 52 has a dense structure with a lower porosity than the first metal layer 51, so the volume shrinkage rate is large when the material is sintered, and cracks may occur if the thickness is too large. On the other hand, the stress relaxation function of the first metal layer 51 increases in proportion to the thickness.

[0093] In the bonding layer 50 of this embodiment, Figure 3As shown, the thickness D1 of the first metal layer 51 along the incident direction in the first region A is greater than the thickness D2 of the second metal layer 52 along the incident direction in the first region A. According to this structure, the reliability of the bonding layer 50 can be further improved by improving the stress relaxation function of the first metal layer 51 and suppressing cracks during sintering of the second metal layer 52.

[0094] Next, a method for manufacturing the wavelength conversion device 40 according to the present embodiment will be described.

[0095] The manufacturing method of the wavelength conversion device 40 of the present embodiment includes: a first step of configuring a first metal material on a substrate 41; a second step of sintering a second metal material configured on a phosphor layer 42 and having a smaller particle size than the first metal material to form a second metal layer 52; and a third step of bonding the second metal layer 52 to the first metal layer 51 formed by sintering the first metal material to generate a bonding layer 50.

[0096] Each step is described below. FIG. 5A to FIG. 5C The diagrams each show a part of the manufacturing process of the wavelength conversion device 40 .

[0097] In the first step, the first metal layer 51 is disposed on the front surface 41a of the substrate 41. As the first metal material 51A, a paste-like material containing particles of at least one metal of Ag, Au, and Cu is used.

[0098] Then, in the second step, Figure 5A As shown, second metal material 52A is disposed on second surface 42b of phosphor layer 42. Second metal material 52A is a paste-like material containing at least one metal particle of Ag, Au, and Cu and having an average particle size smaller than that of first metal material 51A.

[0099] In the case of this embodiment, the phosphor layer 42 is formed by, for example, singulating the phosphor wafer using a dicing blade. In addition, a flattening film 45 and a reflective member 43 are formed in advance on the second surface 42b of the phosphor layer 42. Then, as shown in FIG. Figure 5A As shown, the second metal layer 52 is formed by applying heat H1 to the second metal material 52A to sinter the second metal material 52A. As described above, the second metal layer 52 is formed by sintering the second metal material 52A having a smaller particle size than the first metal material 51A, so the porosity can be smaller than that of the first metal layer 51.

[0100] Alternatively, after sintering the second metal material 52A disposed in a predetermined region on the phosphor wafer to form the second metal layer 52 , the phosphor wafer may be cut into pieces of a predetermined size to manufacture the phosphor layer 42 having the second metal layer 52 formed thereon.

[0101] Next, in the third step, the first metal material 51A is sintered to form the first metal layer 51, and the first metal layer 51 and the second metal layer 52 are bonded to form the bonding layer 50. In the case of this embodiment, in the third step, Figure 5B As shown, the first metal material 51A is sintered while the second metal layer 52 is pressed against the first metal material 51A. In this embodiment, the sintering temperature of the first metal material 51A and the sintering temperature of the second metal material 52A are preferably the same temperature.

[0102] like Figure 5C As shown, the second metal layer 52 is pressed to form a concave portion 53 in the first metal layer 51, and a structure in which the second metal layer 52 is arranged in the concave portion 53 can be formed. Figure 3 The wavelength conversion device 40 of this embodiment is shown.

[0103] In the manufacturing method of the wavelength conversion device 40 of the present embodiment, the porosity of the first metal layer 51 and the second metal layer 52 is adjusted according to the difference in particle size between the first metal material 51A and the second metal material 52A, but other manufacturing methods that adjust the porosity of the first metal layer 51 and the second metal layer 52 according to the difference in sintering temperature between the first metal material 51A and the second metal material 52A may also be used.

[0104] Another manufacturing method of such a wavelength conversion device 40 includes: a first step of configuring a first metal material on a substrate 41; a second step of sintering a second metal material configured on a phosphor layer 42 to form a second metal layer 52; and a third step of bonding the second metal layer 52 to the first metal layer 51 formed by sintering the first metal material at a sintering temperature lower than that of the second metal material to generate a bonding layer 50.

[0105] In the third step of the present manufacturing method, since the sintering temperature of the first metal material is lower than the sintering temperature of the second metal material, the melting degree of the surface of each particle of the first metal material is suppressed compared with the melting degree of the surface of each particle of the second metal material. Therefore, compared with the second metal layer, the gap between each particle of the first metal layer becomes larger, and as a result, the porosity of the first metal layer can be made higher than the porosity of the second metal layer. Therefore, in the present manufacturing method, by adjusting the sintering temperature of the first metal material and the second metal material, it is also possible to manufacture a wavelength conversion device 40 having a bonding layer 50 with a first metal layer 51 and a second metal layer 52 having different porosities from each other. It should be noted that in the present manufacturing method, the first metal material and the second metal material preferably use materials with the same particle size, but the particle sizes of the first metal material and the second metal material can also be made different by appropriately adjusting the sintering temperature.

[0106] Thus, the wavelength conversion device 40 of the present embodiment includes: a phosphor layer 42 having a first surface 42a on which the excitation light BLs is incident and a second surface 42b opposite to the first surface 42a, and converting the incident excitation light BLs; a substrate 41 disposed on the second surface 42b side of the phosphor layer 42; and a bonding layer 50 bonding the substrate 41 to the phosphor layer 42. The bonding layer 50 includes a first metal layer 51 opposed to the substrate 41, and a second metal layer 52 disposed between the first metal layer 51 and the phosphor layer 42, and the porosity of the first metal layer 51 is higher than the porosity of the second metal layer 52.

[0107] According to the wavelength conversion device 40 of the present embodiment, by having the bonding layer 50 including the first metal layer 51 functioning as a stress relief layer and the second metal layer 52 contributing to the improvement of the bonding strength, it is possible to suppress the peeling and damage of the phosphor layer 42 caused by thermal stress, and improve the bonding strength between the phosphor layer 42 and the substrate 41. In addition, the wavelength conversion device 40 of the present embodiment uses the bonding layer 50 including the second metal layer 52 having excellent thermal conductivity to bond the phosphor layer 42 and the substrate 41, so that the phosphor layer 42 can be efficiently cooled to improve the fluorescence conversion efficiency.

[0108] Therefore, the wavelength conversion device 40 of the present embodiment can achieve both improvement in the bonding strength of the phosphor layer 42 and improvement in cooling efficiency.

[0109] Furthermore, according to the method for manufacturing the wavelength conversion device 40 of the present embodiment, by adjusting the particle sizes of the first metal material 51A and the second metal material 52A, it is possible to manufacture a wavelength conversion device 40 having a bonding layer 50 including a first metal layer 51 and a second metal layer 52 having different porosities. Therefore, it is possible to manufacture a wavelength conversion device 40 that takes into account both the bonding strength of the phosphor layer 42 and the improvement of the cooling efficiency.

[0110] Furthermore, the light source device 2A including the wavelength conversion device 40 can realize a highly reliable light source device that generates bright fluorescence YL by suppressing the peeling of the fluorescent layer 42 and improving the cooling efficiency of the fluorescent layer 42 .

[0111] Furthermore, according to the projector 1 of the present embodiment, since the light source device 2A is provided, the projector 1 can form an image with high brightness.

[0112] (Second Embodiment)

[0113] Next, a wavelength conversion device according to a second embodiment will be described. The same components as those in the above embodiment are denoted by the same reference numerals, and detailed descriptions thereof will be omitted.

[0114] Figure 6 1 is a cross-sectional view showing a main structure of the wavelength conversion device 140 according to the present embodiment.

[0115] like Figure 6 As shown, the wavelength conversion device 140 of the present embodiment includes a substrate 41 , a fluorescent layer 42 , a reflective member 43 , and a bonding layer 150 .

[0116] The bonding layer 150 of the present embodiment has a first metal layer 151 and a second metal layer 152. In the present embodiment, the second metal layer 152 is stacked on the front surface 151a of the first metal layer 151 formed by a plane. In a top view, the first metal layer 151 and the second metal layer 152 have the same shape as the phosphor layer 42. That is, in the bonding layer 150 of the present embodiment, the back surface 152b of the second metal layer 152 has the same shape as the front surface 151a of the first metal layer 151, and the front surface 152a of the second metal layer 152 has the same shape as the second surface 42b of the phosphor layer 42.

[0117] According to the wavelength conversion device 140 of the present embodiment, since it has a bonding layer 150 having a first metal layer 151 that functions as a stress relief layer and a second metal layer 152 that helps to improve the bonding strength, it is possible to take into account both the improvement of the bonding strength and the cooling efficiency of the phosphor layer 42. In addition, the wavelength conversion device 240 of the present embodiment has a bonding layer 150 having a structure in which the first metal layer 151 and the second metal layer 152 are stacked, and therefore, the manufacturing process of the bonding layer 150 can be simplified compared to the structure of the first embodiment.

[0118] (Third Embodiment)

[0119] Next, a wavelength conversion device according to a third embodiment will be described. The same components as those in the above embodiment are denoted by the same reference numerals, and detailed descriptions thereof will be omitted.

[0120] Figure 7 2 is a cross-sectional view showing a main structure of a wavelength conversion device 240 according to the present embodiment.

[0121] like Figure 7 As shown, the wavelength conversion device 240 of the present embodiment includes a substrate 41 , a fluorescent layer 42 , a reflective member 43 , and a bonding layer 250 .

[0122] The bonding layer 250 of this embodiment includes a first metal layer 251 and a second metal layer 252. The second metal layer 252 has the same size as the phosphor layer 42, similarly to the wavelength conversion device 140 of the second embodiment. On the other hand, the first metal layer 251 includes a base portion 251a and a convex portion 251b.

[0123] The base portion 251a is a portion that is opposed to the substrate 41 and sandwiched between the substrate 41 and the second metal layer 252. The base portion 251a protrudes outward from the second metal layer 252. The convex portion 251b is a portion that protrudes toward the phosphor layer 42 side from the portion of the base portion 251a that protrudes outward from the second metal layer 252 and is opposed to the third surface 42c of the phosphor layer 42. The third surface 42c of the phosphor layer 42 is a surface that intersects the first surface 42a and the second surface 42b, and is equivalent to the side surface of the phosphor layer 42. That is, the convex portion 251b of the present embodiment is equivalent to the "opposing portion" in the claims.

[0124] In the present embodiment, a part of the convex portion 251 b of the first metal layer 251 is in contact with the third surface 42 c which is the side surface of the phosphor layer 42 .

[0125] According to the wavelength conversion device 240 of the present embodiment, since the bonding layer 250 including the first metal layer 251 functioning as a stress relief layer and the second metal layer 252 contributing to improving the bonding strength is provided, it is possible to achieve both the improvement of the bonding strength of the phosphor layer 42 and the improvement of the cooling efficiency. In addition, since the third surface 42c as the side surface of the phosphor layer 42 is covered by the convex portion 251b of the first metal layer 251, even when an external force is applied for some reason, it is possible to suppress the defect and breakage of the third surface 42c as the side surface of the phosphor layer 42. Therefore, the durability of the phosphor layer 42 can be improved. In addition, since a part of the convex portion 251b is in contact with the third surface 42c of the phosphor layer 42, the heat of the phosphor layer 42 can be released to the first metal layer 251 side via the convex portion 251b. Thus, the cooling efficiency of the phosphor layer 42 can be further improved.

[0126] In addition, the technical scope of the present invention is not limited to the above-mentioned embodiment, and various changes can be added within the scope not departing from the gist of the present invention.

[0127] In the wavelength conversion device 40 of the first embodiment, the first metal layer 51 is arranged so as to surround the entire periphery of the second metal layer 52 in a plan view, but the positional relationship between the second metal layer 52 and the first metal layer 51 is not limited thereto. For example, in a plan view, a portion of the side surface of the second metal layer 52 may be exposed from the first metal layer 51. That is, in a plan view, a portion of the side surface of the first metal layer 51 may be coplanar with the side surface of the second metal layer 52, or a portion of the side surface of the first metal layer 51 may protrude from the side surface of the second metal layer 52.

[0128] In addition, in the wavelength conversion device 40 of the first embodiment, the case where the bonding layer 50 has a size covering the entire second surface 42b of the phosphor layer 42 and the bonding layer 50 is bonded to the peripheral edge 42b1 of the second surface 42b is cited as an example, but the bonding layer 50 may not cover a part of the second surface 42b of the phosphor layer 42. That is, the bonding layer 50 may not be bonded to a part of the peripheral edge 42b1 of the second surface 42b.

[0129] In addition, in the first and second embodiments, the outer periphery of the bonding layer 50, 150 is consistent with the outer periphery of the phosphor layer 42 when viewed from above, but it is also possible that at least a portion of the outer periphery of the bonding layer 50, 150 extends from the outer periphery of the phosphor layer 42.

[0130] Furthermore, the wavelength conversion device of the present invention is not limited to a fixed type, and can be applied to a rotating type wavelength conversion device in which a circular substrate rotates, for example.

[0131] In the first embodiment, the reflective member and the bonding layer are provided. However, if the bonding layer has sufficient reflective properties, the reflective member can be omitted.

[0132] In addition, in the first embodiment, the bonding layer has a first metal layer and a second metal layer, but the number of layers is not limited thereto. For example, it may be more than three layers. It should be noted that the "layer" is not limited to a layer having a clear boundary between substances, and in the case where the porosity gradually changes from the substrate to the phosphor layer, it may also be interpreted as having a plurality of metal layers with different porosities.

[0133] In the above-mentioned embodiment, an example in which the light source device of the present invention is mounted on a projector is shown, but the present invention is not limited thereto. The light source device of the present invention can also be applied to lighting equipment, automobile headlights, and the like.

[0134] The following is a summary of the present disclosure.

[0135] (Note 1)

[0136] A wavelength conversion device comprises: a wavelength conversion layer, which has a first surface on which light is incident and a second surface opposite to the first surface, and converts the incident light; a substrate, which is arranged on the second surface side of the wavelength conversion layer; and a bonding layer, which bonds the substrate to the wavelength conversion layer, the bonding layer comprising: a first metal layer, which is opposite to the substrate; and a second metal layer, which is arranged between the first metal layer and the wavelength conversion layer, the porosity of the first metal layer being higher than the porosity of the second metal layer.

[0137] According to the wavelength conversion device of this structure, by having a bonding layer including a first metal layer having a high porosity and functioning as a stress relief layer and a second metal layer having a low porosity and contributing to improved bonding strength, it is possible to suppress peeling or damage of the wavelength conversion layer caused by thermal stress and improve the bonding strength between the wavelength conversion layer and the substrate. Furthermore, since the wavelength conversion layer and the substrate are bonded by the second metal layer having excellent thermal conductivity, the wavelength conversion layer can be efficiently cooled to improve the wavelength conversion efficiency.

[0138] Therefore, according to this structure, it is possible to achieve both improvement in the bonding strength of the wavelength conversion layer and improvement in the cooling efficiency.

[0139] (Note 2)

[0140] The wavelength conversion device according to Supplementary Note 1, wherein the second metal layer is arranged corresponding to an incident region of the light in the wavelength conversion layer.

[0141] According to this configuration, by arranging the second metal layer having excellent thermal conductivity in the region corresponding to the incident region with the highest temperature in the wavelength conversion layer, the wavelength conversion layer can be efficiently cooled.

[0142] (Note 3)

[0143] The wavelength conversion device according to Supplementary Note 2, wherein the first metal layer is arranged so as to surround the second metal layer.

[0144] According to this structure, since the first metal layer is arranged in a manner surrounding the second metal layer in the bonding surface of the bonding layer, the stress relaxation function achieved by the first metal layer can be evenly exerted in the bonding surface, thereby further improving the effect of suppressing peeling and damage of the fluorescence wavelength conversion layer.

[0145] (Note 4)

[0146] The wavelength conversion device according to any one of Supplementary Notes 1 to 3, wherein the second metal layer is arranged in a recess provided in the first metal layer, and the first metal layer and the second metal layer are in contact with the wavelength conversion layer.

[0147] According to this structure, the first metal layer and the second metal layer are in contact with the wavelength conversion layer. Therefore, the stress relaxation function of the first metal layer and the cooling efficiency improvement function of the second metal layer can be efficiently produced in the bonding surface.

[0148] (Note 5)

[0149] The wavelength conversion device according to any one of Supplementary Notes 1 to 4, wherein the porosity of the first metal layer is greater than or equal to 30% and less than 40%, and the porosity of the second metal layer is greater than or equal to 10% and less than 30%.

[0150] According to this structure, it is possible to realize a bonding layer in which the porosity of the first metal layer is higher than the porosity of the second metal layer.

[0151] (Note 6)

[0152] The wavelength conversion device according to any one of Supplementary Notes 1 to 5, wherein the first metal layer contains at least one of Ag, Au, and Cu, and the second metal layer contains at least one of Ag, Au, and Cu.

[0153] According to this structure, a bonding layer of the first metal layer and the second metal layer having different porosities can be realized.

[0154] (Note 7)

[0155] The wavelength conversion device according to any one of Supplementary Notes 1 to 6, wherein the bonding layer is bonded to a periphery of the second surface of the wavelength conversion layer.

[0156] According to this structure, it is possible to suppress the occurrence of defects such as peeling of the bonding layer, defect of the peripheral edge, and cracks. Therefore, the bonding reliability between the substrate and the wavelength conversion layer can be further improved.

[0157] (Note 8)

[0158] A wavelength conversion device according to any one of Notes 1 to 7, wherein the bonding layer includes a first region where the first metal layer and the second metal layer overlap in an incident direction of the light relative to the wavelength conversion layer, and a thickness of the first metal layer in the first region along the incident direction is greater than a thickness of the second metal layer in the first region along the incident direction.

[0159] According to this structure, the stress relaxation function of the first metal layer is enhanced and cracks in the second metal layer during sintering are suppressed, thereby further improving the reliability of the bonding layer.

[0160] (Note 9)

[0161] A wavelength conversion device according to any one of Notes 1 to 8, wherein the first metal layer includes an opposing portion opposite to the third surface of the wavelength conversion layer, the third surface intersects the first surface and the second surface, and a portion of the opposing portion of the first metal layer is in contact with the third surface of the wavelength conversion layer.

[0162] According to this structure, the third surface of the wavelength conversion layer is covered by the opposing portion of the first metal layer, so even if an external force is applied for some reason, the third surface of the wavelength conversion layer can be prevented from being damaged or broken. Therefore, the durability of the wavelength conversion layer can be improved. In addition, a part of the opposing portion is in contact with the third surface of the wavelength conversion layer, so the heat of the wavelength conversion layer can be released to the first metal layer side via the opposing portion. Thus, the cooling efficiency of the wavelength conversion layer can be further improved.

[0163] (Note 10)

[0164] The wavelength conversion device according to any one of Supplementary Notes 1 to 3, wherein the wavelength conversion layer includes a planarization film that planarizes the second surface.

[0165] According to this structure, the planarization film can improve the flatness of the surface of the wavelength conversion layer. Therefore, the adhesion between the wavelength conversion layer and the bonding layer is improved, and thus the bonding strength of the bonding layer can be further improved.

[0166] (Note 11)

[0167] A light source device comprising: the wavelength conversion device according to any one of Supplementary Notes 1 to 10; and a light source that emits the light toward the wavelength conversion device.

[0168] According to the light source device having this structure, it is possible to provide a light source device with high reliability that generates bright light by suppressing the peeling of the wavelength conversion layer and improving the cooling efficiency of the wavelength conversion layer.

[0169] (Note 12)

[0170] A projector comprising: the light source device according to Supplementary Note 11; a light modulation device that modulates light emitted from the light source device based on image information; and a projection optical system that projects the light emitted from the light modulation device.

[0171] According to the projector having this configuration, since it includes the light source device, the projector can form an image with high brightness.

[0172] (Note 13)

[0173] A method for manufacturing a wavelength conversion device, the wavelength conversion device comprising a wavelength conversion layer, a substrate, and a bonding layer bonding the substrate to the wavelength conversion layer, the bonding layer comprising: a first metal layer, which is opposite to the substrate; and a second metal layer, which has a higher porosity than the first metal layer and is arranged between the first metal layer and the wavelength conversion layer, the method for manufacturing the wavelength conversion device comprising the following steps: a first step, arranging a first metal material on the substrate; a second step, sintering the second metal material arranged on the wavelength conversion layer to form the second metal layer, wherein the particle size of the second metal material is smaller than that of the first metal material; and a third step, bonding the second metal layer to the first metal layer formed by sintering the first metal material to generate the bonding layer.

[0174] According to the manufacturing method of the wavelength conversion device of this structure, by adjusting the particle sizes of the first metal material and the second metal material, a wavelength conversion device having a bonding layer such as the first metal layer and the second metal layer having different porosity can be manufactured. Therefore, a wavelength conversion device that takes into account both the bonding strength of the wavelength conversion layer and the improvement of the cooling efficiency can be provided.

[0175] (Note 14)

[0176] A method for manufacturing a wavelength conversion device, the wavelength conversion device comprising a wavelength conversion layer, a substrate, and a bonding layer bonding the substrate to the wavelength conversion layer, the bonding layer comprising: a first metal layer, which is opposite to the substrate; and a second metal layer, which has a higher porosity than the first metal layer and is arranged between the first metal layer and the wavelength conversion layer, the method for manufacturing the wavelength conversion device comprising the following steps: a first step of arranging a first metal material on the substrate; a second step of sintering the second metal material arranged on the wavelength conversion layer to form the second metal layer; and a third step of bonding the first metal layer to the second metal layer to generate the bonding layer, wherein the first metal layer is formed by sintering the first metal material at a sintering temperature lower than that of the second metal material.

[0177] According to the manufacturing method of the wavelength conversion device of this structure, by adjusting the sintering temperature of the first metal material and the second metal material, a wavelength conversion device having a bonding layer such as the first metal layer and the second metal layer having different porosities can be manufactured. Therefore, a wavelength conversion device that takes into account both the bonding strength of the wavelength conversion layer and the improvement of the cooling efficiency can be provided.

[0178] (Note 15)

[0179] A method for manufacturing a wavelength conversion device according to Note 13 or Note 14, wherein in the first process, metal particles containing at least one of Ag, Au, and Cu are used as the first metal material, and in the second process, metal particles containing at least one of Ag, Au, and Cu are used as the second metal material.

[0180] According to this structure, by sintering the first metal material and the second metal material, the above-mentioned bonding layer including the first metal layer and the second metal layer having different porosities can be manufactured.

[0181] (Note 16)

[0182] The method for manufacturing a wavelength conversion device according to any one of Supplementary Notes 13 to 15, wherein in the third step, the first metal material is sintered in a state where the second metal layer is pressed against the first metal material.

[0183] According to this configuration, it is possible to manufacture a structure in which the second metal layer is arranged in the recessed portion formed in the first metal layer.

Claims

1. A wavelength conversion device, comprising: A wavelength conversion layer having a first surface on which light is incident and a second surface opposite to the first surface, and converting the incident light; a substrate disposed on the second surface side of the wavelength conversion layer; as well as a bonding layer bonding the substrate and the wavelength conversion layer, The bonding layer has: A first metal layer, which is opposite to the substrate; as well as a second metal layer disposed between the first metal layer and the wavelength conversion layer, The porosity of the first metal layer is higher than that of the second metal layer.

2. The wavelength conversion device according to claim 1, wherein: The second metal layer is arranged corresponding to an incident region of the light in the wavelength conversion layer.

3. The wavelength conversion device according to claim 2, wherein: The first metal layer is arranged to surround the second metal layer.

4. The wavelength conversion device according to any one of claims 1 to 3, wherein: The second metal layer is arranged in a recessed portion provided in the first metal layer, The first metal layer and the second metal layer are in contact with the wavelength conversion layer.

5. The wavelength conversion device according to any one of claims 1 to 3, wherein: The porosity of the first metal layer is greater than 30% and less than 40%, The porosity of the second metal layer is greater than or equal to 10% and less than 30%.

6. The wavelength conversion device according to any one of claims 1 to 3, wherein: The first metal layer contains at least one of Ag, Au, and Cu. The second metal layer contains at least one of Ag, Au, and Cu.

7. The wavelength conversion device according to any one of claims 1 to 3, wherein: The bonding layer is bonded to a periphery of the second surface of the wavelength conversion layer.

8. The wavelength conversion device according to any one of claims 1 to 3, wherein: The bonding layer includes a first region where the first metal layer and the second metal layer overlap in the incident direction of light with respect to the wavelength conversion layer, A thickness of the first metal layer in the first region along the incident direction is greater than a thickness of the second metal layer in the first region along the incident direction.

9. The wavelength conversion device according to any one of claims 1 to 3, wherein: The first metal layer includes an opposing portion that is opposite to a third surface of the wavelength conversion layer, and the third surface intersects the first surface and the second surface. A portion of the opposed portion of the first metal layer is in contact with the third surface of the wavelength conversion layer.

10. The wavelength conversion device according to any one of claims 1 to 3, wherein: The wavelength conversion layer includes a planarization film that planarizes the second surface.

11. A light source device, comprising: The wavelength conversion device according to any one of claims 1 to 3; and A light source emits the light toward the wavelength conversion device.

12. A projector, comprising: The light source device according to claim 11; a light modulation device that modulates light emitted from the light source device based on image information; and A projection optical system projects the light emitted from the light modulation device.

13. A method for manufacturing a wavelength conversion device, The wavelength conversion device comprises a wavelength conversion layer, a substrate, and a bonding layer bonding the substrate and the wavelength conversion layer. The bonding layer has: A first metal layer, which is opposite to the substrate; as well as The second metal layer has a lower porosity than the first metal layer and is disposed between the first metal layer and the wavelength conversion layer. The method for manufacturing the wavelength conversion device comprises the following steps: The first step is to place a first metal material on the substrate; The second step is to sinter the second metal material disposed on the wavelength conversion layer to form the second metal layer, wherein: The particle size of the second metal material is smaller than the particle size of the first metal material; as well as In a third step, the second metal layer is bonded to the first metal layer formed by sintering the first metal material to generate the bonding layer.

14. A method for manufacturing a wavelength conversion device, The wavelength conversion device comprises a wavelength conversion layer, a substrate, and a bonding layer bonding the substrate and the wavelength conversion layer. The bonding layer has: A first metal layer, which is opposite to the substrate; as well as The second metal layer has a lower porosity than the first metal layer and is disposed between the first metal layer and the wavelength conversion layer. The method for manufacturing the wavelength conversion device comprises the following steps: The first step is to arrange a first metal material on the substrate; A second step of sintering a second metal material disposed on the wavelength conversion layer to form the second metal layer; as well as The third step is to bond the first metal layer and the second metal layer to generate the bonded layer, wherein the first metal layer is formed by sintering the first metal material at a lower sintering temperature than the second metal material.

15. The method for manufacturing a wavelength conversion device according to claim 13 or 14, wherein: In the first step, metal particles containing at least one of Ag, Au, and Cu are used as the first metal material. In the second step, metal particles containing at least one of Ag, Au, and Cu are used as the second metal material.

16. The method for manufacturing a wavelength conversion device according to claim 13 or 14, wherein: In the third step, the first metal material is sintered in a state where the second metal layer is pressed against the first metal material.

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