Wavelength conversion component for brazing, wavelength conversion device and light source device

Abstract

The wavelength conversion component for brazing comprises: a ceramic phosphor that converts the wavelength of light incident from an incident surface; a reflective layer that is arranged on the back side of the ceramic phosphor on the side opposite to the incident surface and covers a part of or the entire back side; and a bonding layer that is composed of one or more films and covers the back side of the ceramic phosphor and at least the reflective layer of the reflective layer, and the bonding layer has a protrusion protruding relative to the outer periphery at the center of the surface on the side opposite to the surface covering the back side and at least the reflective layer of the reflective layer.

Description

Technical Field

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

[0002] In the past, a wavelength conversion device for converting the wavelength of light emitted by a light source is known. The wavelength conversion device is usually composed of a phosphor that converts the wavelength of incident light, a heat dissipation component, and a solder layer that joins the phosphor and the heat dissipation component, and the heat dissipation component is used to dissipate the heat of the phosphor. At this time, the voids contained in the solder will cause the thermal conductivity between the phosphor and the heat dissipation component to decrease. For example, Patent Document 1 discloses a technology for making the size of the voids contained in the solder layer less than a predetermined value.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent No. 6020631 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] However, even when the phosphor and the heat dissipation member are bonded together using the technique described in Patent Document 1, a gap remains between the phosphor and the heat dissipation member, and thus it is difficult to further improve the thermal conductivity of the solder layer.

[0008] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a technology for improving the thermal conductivity between a ceramic phosphor and a heat dissipation member in a wavelength conversion member for soldering.

[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 achieved by the following means.

[0011] (1) According to one technical solution of the present invention, there is provided a wavelength conversion component for brazing. The wavelength conversion component for brazing comprises: a ceramic phosphor that converts the wavelength of light incident from an incident surface; a reflective layer that is disposed on the back surface of the ceramic phosphor on the side opposite to the incident surface, covering a part of or the entire back surface; and a bonding layer that is composed of one or more films, covers the back surface of the ceramic phosphor and at least the reflective layer, wherein the bonding layer has a protrusion protruding relative to the outer periphery at the center of the surface on the side opposite to the surface covering the back surface and at least the reflective layer.

[0012] With this structure, the bonding layer has a protrusion protruding relative to the periphery at the center of the surface on the side opposite to the surface on the side covering the reflective layer. When the ceramic phosphor and the heat dissipation component are brazed with the aid of the bonding layer, the solder disposed between the bonding layer and the heat dissipation component and located between the protrusion and the heat dissipation component is squeezed out from the center toward the outside. At this time, the voids contained in the solder between the protrusion and the heat dissipation component move together with the solder from between the protrusion and the heat dissipation component to between the periphery and the heat dissipation component. As a result, the number of voids between the protrusion and the heat dissipation component decreases, and therefore, heat transfer between the ceramic phosphor and the heat dissipation component is not easily hindered by the voids. Therefore, the thermal conductivity between the ceramic phosphor and the heat dissipation component can be improved.

[0013] (2) In the wavelength conversion component for soldering of the above technical solution, the bonding layer may directly cover both the exposed surface of the back side of the ceramic phosphor and the reflective layer, and the protrusion in the bonding layer covers the reflective layer. With this structure, the reflective layer is formed to cover a portion of the back side of the ceramic phosphor. Therefore, when the bonding layer is formed on the exposed back side of the ceramic phosphor and on the reflective layer, the bonding layer formed on the reflective layer protrudes more than the bonding layer formed on the back side of the ceramic phosphor. That is, the protrusion of the bonding layer is formed on the reflective layer, and the peripheral portion of the bonding layer is formed on the exposed back side of the ceramic phosphor. Thus, the shape of the reflective layer can be used to form a bonding layer having a protrusion and a peripheral portion, so that the thermal conductivity between the ceramic phosphor and the heat dissipation component can be easily improved.

[0014] (3) In the wavelength conversion component for soldering of the above technical solution, the bonding layer may also include: a bonding film; and a sealing film, which is composed of chromium or titanium, and the sealing film is arranged between the ceramic phosphor and the bonding film to make the ceramic phosphor and the bonding film close to each other. With this structure, the bonding layer covering both the back side of the ceramic phosphor and the reflective layer has a bonding film for soldering the ceramic phosphor to a heat dissipation component, etc., and a sealing film arranged between the ceramic phosphor and the bonding film. The sealing film improves the adhesion between the ceramic phosphor and the bonding film, thereby improving the bonding strength between the ceramic phosphor and the heat dissipation component based on soldering. As a result, poor bonding between the ceramic phosphor and the heat dissipation component can be suppressed.

[0015] (4) In the above-mentioned wavelength conversion component for soldering of the technical solution, the film constituting the surface of the bonding layer on the side opposite to the surface covering the back surface and at least the side of the reflecting layer may be mainly composed of at least one of nickel, palladium, platinum, molybdenum, and tungsten. With this structure, the film constituting the surface of the bonding layer on the side opposite to the surface covering the reflecting layer is mainly composed of at least one of nickel, palladium, platinum, molybdenum, and tungsten, which has a relatively high melting point and is not easily oxidized and nitrided. As a result, the film constituting the surface of the bonding layer on the side opposite to the surface covering the reflecting layer is not easily diffused relative to gold, so the amount of the components of the bonding layer dissolved in the solder is suppressed, which can suppress the poor bonding between the ceramic phosphor and the heat dissipation component.

[0016] (5) According to another technical solution of the present invention, a wavelength conversion device is provided. The wavelength conversion device comprises: the above-mentioned wavelength conversion member for brazing; a heat dissipation member that releases the heat of the ceramic phosphor to the outside; and a solder layer that is arranged between the bonding layer and the heat dissipation member to bond the wavelength conversion member for brazing and the heat dissipation member, and the solder layer has a recessed portion surrounding the protruding portion of the bonding layer. With this structure, when the ceramic phosphor and the heat dissipation member are brazed, the solder that is squeezed out from the center toward the outside and located between the protruding portion and the heat dissipation member moves toward the outer peripheral portion of the bonding layer and the heat dissipation member, and forms a recessed portion around the protruding portion. At this time, the voids contained in the solder between the protruding portion and the heat dissipation member also move from between the protruding portion and the heat dissipation member to the recessed portion, so that the number of voids between the protruding portion and the heat dissipation member decreases. As a result, the heat transfer between the ceramic phosphor and the heat dissipation member is not easily hindered by the voids, so the thermal conductivity between the ceramic phosphor and the heat dissipation member can be improved.

[0017] (6) According to another technical solution of the present invention, a light source device is provided. The light source device comprises: the above-mentioned wavelength conversion device; and a light source that irradiates light to the ceramic phosphor. With this structure, the light source device releases light having a wavelength different from the wavelength of the light irradiated by the light source to the ceramic phosphor to the outside. In a wavelength conversion device having a ceramic phosphor that converts the wavelength of light, the heat generated when the wavelength of light is converted by the ceramic phosphor is released to the outside from the heat dissipation component through solder. In the wavelength conversion device, the number of gaps between the protrusion and the heat dissipation component is reduced by the protrusion of the bonding layer, so that the heat of the ceramic phosphor is easily transferred to the heat dissipation component. As a result, the reduction in the luminous intensity of the light source device caused by temperature quenching can be suppressed.

[0018] In addition, the present invention can be implemented in various schemes, for example, it can be implemented in the form of a light emitting system using a wavelength conversion component or a wavelength conversion device for brazing, a manufacturing method of a wavelength conversion component, a wavelength conversion device or a light source device for brazing, a computer program that enables a computer to execute these manufacturing methods, a server device for distributing computer programs, a non-temporary storage medium for storing computer programs, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a cross-sectional view of a light source device including the wavelength conversion device according to the first embodiment.

[0020] Figure 2 It is a cross-sectional view of the wavelength conversion member for soldering according to the first embodiment.

[0021] Figure 3 This is a diagram for explaining the method for manufacturing the wavelength conversion device according to the first embodiment.

[0022] Figure 4 It is a cross-sectional view of a light source device including a wavelength conversion device according to a second embodiment.

[0023] Figure 5 It is a cross-sectional view of a wavelength conversion member for soldering according to a second embodiment.

[0024] Figure 6 It is a cross-sectional view of a light source device including a wavelength conversion device according to a third embodiment.

[0025] Figure 7 It is a cross-sectional view of a wavelength conversion member for soldering according to a third embodiment.

[0026] Figure 8 It is a cross-sectional view of a light source device including a wavelength conversion device according to a fourth embodiment.

[0027] Fig. 9 It is a cross-sectional view of a wavelength conversion member for soldering according to a fourth embodiment. DETAILED DESCRIPTION

[0028] <First embodiment>

[0029] Figure 1This is a cross-sectional view of a light source device 5a having a wavelength conversion device 6a of the first embodiment. The light source device 5a of this embodiment includes a light source 7 and a wavelength conversion device 6a. When the wavelength conversion device 6a is irradiated with light L1 emitted by an external light source 7 such as a light emitting diode (LED: Light Emitting Diode) or a semiconductor laser (LD: Laser Diode), the wavelength conversion device 6a generates light L2 having a wavelength different from that of the light L1. The wavelength conversion device 6a is used in various optical devices such as headlights, lighting, and projectors. The wavelength conversion device 6a includes a wavelength conversion component 1a for soldering, a heat dissipation component 40, and a solder layer 50. In addition, in Figure 1 In the figure, for convenience of explanation, the thickness relationship among the wavelength conversion member 1 a for soldering, the heat dissipation member 40 , and the solder layer 50 is shown in the figure in a manner different from the actual thickness relationship.

[0030] Figure 2 1 is a cross-sectional view of a wavelength conversion component 1a for soldering according to the first embodiment. The wavelength conversion component 1a for soldering includes a ceramic phosphor 10, a reflective layer 20, and a bonding layer 30. The ceramic phosphor 10 is composed of a ceramic sintered body, and converts the wavelength of light incident from an incident surface 11. The ceramic sintered body has: a fluorescent phase, which is composed mainly of crystal particles having fluorescence; and a light-transmitting phase, which is composed mainly of crystal particles having light-transmitting properties. Preferably, the crystal particles of the light-transmitting phase have a chemical formula of Al 2 O 3 The composition of the fluorescent phase crystal particles has a chemical formula A 3 B 5 O 12 : The composition represented by Ce (the so-called garnet structure). 3 B 5 O 12 :Ce" means in A 3 B 5 O 12 Ce is solid-dissolved in the SiO2O3 and part of the element A is replaced by Ce.

[0031] Chemical formula A 3 B 5 O 12 : The element A and the element B in Ce are each composed of at least one element selected from the following element group.

[0032] Element A: Lanthanide elements other than Sc, Y, and Ce (wherein element A may also include Gd)

[0033] Element B: Al (wherein, element B may further contain Ga)

[0034] By using a ceramic sintered body as the ceramic phosphor 10, light is scattered at the interface between the fluorescent phase and the light-transmitting phase, and the angular dependence of the color of the light can be reduced. Thus, the color homogeneity can be improved. In addition, the material of the ceramic phosphor 10 is not limited to the above-mentioned materials.

[0035] The reflective layer 20 is disposed on the back surface 12 of the ceramic phosphor 10 opposite to the incident surface 11, and is formed to cover the entire back surface 12. The reflective layer 20 includes a high reflective film 21 and a reflective film 22. In the reflective layer 20, the high reflective film 21 and the reflective film 22 are sequentially disposed from the ceramic phosphor 10 side.

[0036] The high reflection film 21 has a titanium oxide (TiO 2 ) and the first layer 21a made of silicon oxide (SiO 2 ) is formed of a second layer 21b. The high reflection film 21 reflects the light inside the ceramic phosphor 10 due to the difference in refractive index between the first layer 21a and the second layer 21b. The reflection film 22 is formed of silver (Ag) or aluminum (Al), and reflects the light inside the ceramic phosphor 10 after passing through the high reflection film 21. In addition, the structure of the above-mentioned reflection layer 20 is an example, for example, it can be a single-layer film formed of aluminum, niobium oxide, titanium oxide, lanthanum oxide, tantalum oxide, yttrium oxide, gadolinium oxide, tungsten oxide, hafnium oxide, aluminum oxide, and silicon oxide, or it can be a multilayer film formed of materials different from the above-mentioned materials.

[0037] The bonding layer 30 is arranged on the lower surface 23 of the reflective layer 20 on the side opposite to the ceramic phosphor 10 side, and the bonding layer 30 is composed of one or more films covering the reflective layer 20. In the present embodiment, the bonding layer 30 has a protective film 31, a sealing film 32, and a bonding film 33. In the bonding layer 30, the protective film 31, the sealing film 32, and the bonding film 33 are arranged in order from the ceramic phosphor 10 side.

[0038] The protective film 31 is made of aluminum oxide (Al 2 O 3 ) is formed to suppress oxidation of the reflective film 22. The adhesion film 32 is formed of chromium (Cr) or titanium (Ti) to improve the adhesion between the protective film 31 and the bonding film 33. In addition, the materials forming the protective film 31 and the adhesion film 32 are not limited thereto.

[0039] The bonding film 33 is a film constituting the surface 35 on the side opposite to the surface 34 on the side covering the reflective layer 20 in the bonding layer 30. The bonding film 33 is formed of a material having at least one of nickel (Ni), palladium (Pd), platinum (Pt), molybdenum (Mo), and tungsten (W) as a main component. In this embodiment, the bonding film 33 has nickel (Ni) as a main component. Here, the "main component" refers to a component detected to contain 50 at% or more by EDS analysis. Figure 2 As shown, the bonding film 33 has a protrusion 37 protruding relative to the outer peripheral portion 36 at the center of the surface 35 of the bonding layer 30 opposite to the surface 34 covering the reflective layer 20. Figure 2 As shown, the bonding film 33 has a convex shape. Here, the convex shape means that the bonding film 33 has a portion with different film thicknesses and is formed in a step-like shape. The bonding film 33 reacts with the solder to bond the ceramic phosphor 10 and the solder.

[0040] The heat dissipation member 40 is formed of a material having a higher thermal conductivity than the ceramic phosphor 10, such as copper, copper-molybdenum alloy, copper-tungsten alloy, aluminum, aluminum nitride, etc. A metal film (not shown) is arranged on the main surface 41 of the heat dissipation member 40 on the side of the ceramic phosphor 10. The metal film improves the wettability of the heat dissipation member 40 with respect to the solder. The heat dissipation member 40 releases the heat of the ceramic phosphor 10 transmitted via the solder layer 50 and the like to the outside. In addition, the heat dissipation member 40 may be a member of a single-layer structure formed of the above-mentioned materials, or a member of a multi-layer structure formed of the same material or different materials.

[0041] The solder layer 50 is provided between the bonding layer 30 and the heat dissipation member 40 and is formed of gold and tin. Figure 1 As shown, the solder layer 50 has a central portion 51 located between the protruding portion 37 of the bonding film 33 and the heat dissipation member 40, and a recessed portion 52 disposed outside the central portion 51 and surrounding the protruding portion 37 of the bonding film 33. Figure 1 As shown, the height H2 of the recessed portion 52 from the main surface 41 of the heat dissipating member 40 is higher than the height H1 of the central portion 51 from the main surface 41. The solder layer 50 joins the wavelength conversion member 1a for soldering and the heat dissipating member 40 together.

[0042] Next, a method for manufacturing the wavelength conversion device 6a is described. First, the reflective layer 20 and the bonding layer 30 are sequentially formed on the ceramic phosphor 10 by vacuum evaporation or sputtering. In the process of forming the bonding film 33, after forming a film of an amount corresponding to the thickness of the protrusion 37, patterning is performed by photolithography to form a film on the peripheral portion 36 and the protrusion 37. In addition, a metal film is plated on the heat dissipation component 40. Next, in a state where a foil of gold-tin solder is sandwiched between the bonding film 33 of the ceramic phosphor 10 and the metal film of the heat dissipation component 40, the ceramic phosphor 10 and the heat dissipation component 40 are heated in a reflow furnace in a nitrogen atmosphere or a hydrogen atmosphere to bond them together. In addition, in the case where a metal film is formed on the surface of the heat dissipation component 40, the film formation can also be performed by plating. In addition, instead of using a foil of gold-tin solder, a gold-tin alloy paste can be used.

[0043] Figure 31 is a diagram for explaining a method for manufacturing the wavelength conversion device 6a. When the ceramic phosphor 10 and the heat dissipation member 40 are joined by heating in a reflow furnace, in the gold-tin paste that becomes the solder layer 50, as shown in FIG. Figure 3 As shown in (a), a gap V1 is generated due to the gap between the components. When the ceramic phosphor 10 and the heat dissipation component 40 are pressed and joined together (refer to Figure 3 The solder in the solder layer 50 between the protrusion 37 and the heat dissipation member 40 is squeezed out from between the protrusion 37 and the heat dissipation member 40 and overflows to the outside of the protrusion 37. At this time, the gap V1 between the protrusion 37 and the heat dissipation member 40 is squeezed out from between the protrusion 37 and the heat dissipation member 40 together with the solder ( Figure 3 The solder that overflows to the outside of the protrusion 37 bulges between the outer peripheral portion 36 and the heat dissipation member 40, forming a concave portion 52 surrounding the protrusion 37. At this time, the gap V1 moves together with the solder that bulges between the outer peripheral portion 36 and the heat dissipation member 40 ( Figure 3 As shown in the dashed arrow D2 of (a), the gap V1 between the protrusion 37 and the heat dissipation member 40 moves toward the recess 52. Figure 3 As shown in (b), the voids V1 of the solder layer 50 are concentrated in the recess 52, and the number of voids V1 in the central portion 51 decreases. When the number of voids V1 in the central portion 51 decreases, heat conduction between the ceramic phosphor 10 and the heat dissipation member 40 in the central portion 51 is less likely to be hindered by the voids V1.

[0044] According to the above-described wavelength conversion member 1a for soldering of the present embodiment, the bonding layer 30 has a protrusion 37 protruding relative to the peripheral portion 36 at the center of the surface 35 on the side opposite to the surface 34 on the side covering the reflective layer 20. When the ceramic phosphor 10 and the heat dissipation member 40 are soldered by means of the bonding layer 30, the solder located between the protrusion 37 and the heat dissipation member 40 among the solder arranged between the bonding layer 30 and the heat dissipation member 40 is squeezed out from the center toward the outside. At this time, the voids V1 contained in the solder between the protrusion 37 and the heat dissipation member 40 move from between the protrusion 37 and the heat dissipation member 40 to between the peripheral portion 36 and the heat dissipation member 40 together with the solder. As a result, the number of voids V1 between the protrusion 37 and the heat dissipation member 40 is reduced, and therefore, the heat transfer between the ceramic phosphor 10 and the heat dissipation member 40 is not easily hindered by the voids V1. Therefore, the thermal conductivity between the ceramic phosphor 10 and the heat dissipation member 40 can be improved.

[0045] In addition, according to the wavelength conversion member 1a for soldering of the present embodiment, the bonding film 33 constituting the surface 35 on the side opposite to the surface 34 on the side covering the reflective layer 20 in the bonding layer 30 is formed of a material having nickel (Ni) as a main component. As a result, it is possible to suppress the diffusion of the components of the bonding layer 30 from the bonding layer 30 to the solder when the wavelength conversion member 1a for soldering and the heat dissipation member 40 are bonded by solder. Therefore, the amount of the components of the bonding layer 30 dissolved in the solder is suppressed, so that poor bonding between the ceramic phosphor 10 and the heat dissipation member 40 can be suppressed.

[0046] In addition, according to the wavelength conversion device 6a of the present embodiment, the solder layer 50 has a recess 52 surrounding the protrusion 37 of the bonding layer 30. When the ceramic phosphor 10 and the heat dissipation member 40 are brazed, the solder between the protrusion 37 and the heat dissipation member 40, which is squeezed out from the center toward the outside, moves between the outer peripheral portion 36 of the bonding layer 30 and the heat dissipation member 40, and the recess 52 is formed around the protrusion 37. At this time, the voids V1 contained in the solder between the protrusion 37 and the heat dissipation member 40 also move from between the protrusion 37 and the heat dissipation member 40 to the recess 52, so that the number of voids V1 between the protrusion 37 and the heat dissipation member 40 decreases. As a result, the heat transfer between the ceramic phosphor 10 and the heat dissipation member 40 is not easily hindered by the voids V1, so that the thermal conductivity between the ceramic phosphor 10 and the heat dissipation member 40 can be improved.

[0047] In addition, according to the light source device 5a of the present embodiment, the light source device 5a releases the light L2 having a wavelength different from the wavelength of the light L1 irradiated from the light source 7 to the ceramic phosphor 10 to the outside. In the wavelength conversion device 6a having the ceramic phosphor 10 that converts the wavelength of the light L1, the heat generated when the wavelength of the light L1 is converted by the ceramic phosphor 10 is released to the outside from the heat dissipation member 40 through the solder. In the wavelength conversion device 6a, the number of gaps V1 between the protrusion 37 and the heat dissipation member 40 is reduced by the protrusion 37 of the bonding layer 30, so that the heat of the ceramic phosphor 10 is easily transferred to the heat dissipation member 40. As a result, the reduction in the luminous intensity of the light source device 5a due to temperature quenching can be suppressed.

[0048] <Second embodiment>

[0049] Figure 4 It is a cross-sectional view of a light source device 5b including a wavelength conversion device 6b in the second embodiment. Figure 5 1b is a cross-sectional view of a wavelength conversion member for soldering 1b of the present embodiment. The wavelength conversion member for soldering 1b of the wavelength conversion device 6b of the present embodiment is different from the wavelength conversion member for soldering 1a ( Figure 2 ) is different in that the bonding layer 60 has a solder wetting film 38.

[0050] The wavelength conversion member 1b for soldering of the present embodiment includes a ceramic phosphor 10, a reflective layer 20, and a bonding layer 60. The bonding layer 60 is disposed on the lower surface 23 of the reflective layer 20 on the side opposite to the ceramic phosphor 10 side, and is composed of one or more films covering the reflective layer 20. In the present embodiment, the bonding layer 60 includes a protective film 31, a sealing film 32, a bonding film 33, and a solder wetting film 38.

[0051] The solder wetting film 38 is arranged so as to cover the surface 35 of the bonding film 33 and is formed of gold. The solder wetting film 38 has a peripheral portion 38a and a protruding portion 38b. The peripheral portion 38a covers a surface 35a formed by the peripheral portion 36 of the surface 35 of the bonding film 33. The protruding portion 38b covers a surface 35b formed by the protruding portion 37 of the surface 35 of the bonding film 33. The film thickness of the peripheral portion 38a and the film thickness of the protruding portion 38b are substantially the same. The peripheral portion 38a and the protruding portion 38b improve the solder wettability of the ceramic phosphor 10.

[0052] Next, a method for manufacturing the wavelength conversion device 6b is described. In the wavelength conversion device 6b, first, the reflective layer 20 and the bonding layer 60 are formed on the ceramic phosphor 10 in sequence by vacuum evaporation or sputtering. At this time, after the bonding film 33 having the outer peripheral portion 36 and the protruding portion 37 is formed by photolithography in the same manner as in the first embodiment, the solder wetting film 38 is formed on the bonding film 33. Thereafter, in a state where a foil of gold-tin solder is sandwiched between the solder wetting film 38 of the ceramic phosphor 10 and the metal film of the heat dissipation member 40, the ceramic phosphor 10 and the heat dissipation member 40 are heated in a reflow furnace to bond the ceramic phosphor 10 and the heat dissipation member 40.

[0053] According to the above-described wavelength conversion member 1b for soldering of the present embodiment, when the ceramic phosphor 10 and the heat dissipation member 40 are soldered via the bonding layer 60, the voids contained in the solder between the protrusion 38b and the heat dissipation member 40 move together with the solder from between the protrusion 38b and the heat dissipation member 40 to between the outer peripheral portion 38a and the heat dissipation member 40. As a result, the number of voids between the protrusion 38b and the heat dissipation member 40 decreases, and thus the thermal conductivity between the ceramic phosphor 10 and the heat dissipation member 40 can be improved.

[0054] In addition, according to the soldering wavelength conversion member 1b of the present embodiment, the bonding layer 60 has the outer peripheral portion 38a and the protruding portion 38b with good solder wettability. As a result, the voids V1 contained in the solder between the protruding portion 38b and the heat dissipation member 40 are easily moved further between the outer peripheral portion 38a and the heat dissipation member 40, so the number of voids V1 between the protruding portion 38b and the heat dissipation member 40 is further reduced. Therefore, the thermal conductivity between the ceramic phosphor 10 and the heat dissipation member 40 can be further improved.

[0055] <Third embodiment>

[0056] Figure 6 It is a cross-sectional view of a light source device 5c including a wavelength conversion device 6c according to the third embodiment. Figure 7 1c is a cross-sectional view of a wavelength conversion member for soldering 1c of the present embodiment. The wavelength conversion member for soldering 1c of the wavelength conversion device 6c of the present embodiment is different from the wavelength conversion member for soldering 1b of the second embodiment ( Figure 5 ) compared to the embodiment shown in FIG. 1 , the width of the reflective layer 25 is different.

[0057] The wavelength conversion member 1c for soldering of this embodiment includes a ceramic phosphor 10, a reflective layer 25, and a bonding layer 70. Figure 7 As shown, the width of the reflective layer 25 having the high reflective film 21 and the reflective film 22 is smaller than the width of the back surface 12 of the ceramic phosphor 10. The bonding layer 70 is composed of one or more films that directly cover both the exposed back surface 12a of the back surface 12 of the ceramic phosphor 10 and the reflective layer 25. In the present embodiment, the bonding layer 70 includes a bonding film 71, a bonding film 72, and a solder wetting film 73.

[0058] The bonding film 71 is formed of chromium (Cr) or titanium (Ti). The bonding film 71 has: a peripheral portion 71a, which is arranged on the exposed back surface 12a of the ceramic phosphor 10; and a protrusion 71b, which is arranged on the lower surface 23 of the reflective layer 25 on the side opposite to the ceramic phosphor 10. In the present embodiment, the peripheral portion 71a and the protrusion 71b are cut off. The film thickness of the peripheral portion 71a and the film thickness of the protrusion 71b are substantially the same, and the film thicknesses are both greater than 10nm and less than 500nm. The bonding film 71 improves the adhesion between the reflective layer 25 and the bonding film 72 and the adhesion between the ceramic phosphor 10 and the bonding film 72. In the present embodiment, by making the film thickness of the bonding film 71 greater than 10nm and less than 500nm, the adhesion between the ceramic phosphor 10 and the bonding film 72 can be further improved. In addition, in the present embodiment, the film thickness of the outer peripheral portion 71 a and the film thickness of the protruding portion 71 b are substantially the same, but they may be different.

[0059] The bonding film 72 is formed of a material containing nickel (Ni) as a main component. The bonding film 72 includes: an outer peripheral portion 72a covering the outer peripheral portion 71a of the bonding film 71; and a protruding portion 72b covering the protruding portion 71b of the bonding film 71. The outer peripheral portion 72a and the protruding portion 72b are cut off, and the film thickness of the outer peripheral portion 72a and the film thickness of the protruding portion 72b are substantially the same. The bonding film 72 reacts with the solder wetting film 73 to bond the ceramic phosphor 10 and the solder wetting film 73.

[0060] The solder wetting film 73 is formed of gold (Au) and has an outer peripheral portion 73a covering the outer peripheral portion 72a of the bonding film 72 and a protruding portion 73b covering the protruding portion 72b of the bonding film 72. The outer peripheral portion 73a and the protruding portion 73b are cut off, and the film thickness of the outer peripheral portion 73a and the film thickness of the protruding portion 73b are substantially the same. The solder wetting film 73 improves the solder wettability of the ceramic phosphor 10.

[0061] Thus, in the present embodiment, the bonding layer 70 has protrusions 71b, 72b, 73b protruding relative to the peripheral portions 71a, 72a, 73a at the center of the surface 75 on the side opposite to the surface 74 on the side directly covering both the back surface 12a of the ceramic phosphor 10 and the reflective layer 25. The protrusions 71b, 72b, 73b are formed to cover the reflective layer 25.

[0062] Next, a method for manufacturing the wavelength conversion device 6c is described. In the wavelength conversion device 6c, first, the reflective layer 25 and the bonding layer 70 are sequentially formed on the ceramic phosphor 10 by vacuum evaporation or sputtering. At this time, photolithography is used to form the reflective layer 25 in such a way that the width of the reflective layer 25 is smaller than the width of the back surface 12 of the ceramic phosphor 10. After the reflective layer 25 is formed, the bonding layer 70 is formed on the lower surface 23 of the reflective layer 25 on the side opposite to the ceramic phosphor 10 side and on the back surface 12a of the ceramic phosphor 10 exposed from the periphery of the reflective layer 25. Thereafter, the ceramic phosphor 10 and the heat dissipation member 40 are heated in a reflow furnace in a state where a foil of gold-tin solder is sandwiched between the solder wet film 73 of the ceramic phosphor 10 and the metal film of the heat dissipation member 40, so that the ceramic phosphor 10 and the heat dissipation member 40 are bonded.

[0063] According to the above-described soldering wavelength conversion member 1c of the present embodiment, when the ceramic phosphor 10 and the heat dissipation member 40 are soldered via the bonding layer 70, the voids contained in the solder between the protrusion 73b and the heat dissipation member 40 move together with the solder from between the protrusion 73b and the heat dissipation member 40 to between the outer peripheral portion 73a and the heat dissipation member 40. As a result, the number of voids between the protrusion 73b and the heat dissipation member 40 decreases, and thus the thermal conductivity between the ceramic phosphor 10 and the heat dissipation member 40 can be improved.

[0064] In addition, according to the wavelength conversion member 1c for soldering of the present embodiment, the reflective layer 25 is formed to cover a part of the back surface 12 of the ceramic phosphor 10, so when the bonding layer 70 is formed on the exposed back surface 12a of the ceramic phosphor 10 and on the reflective layer 25, the bonding layer 70 formed on the reflective layer 25 protrudes more than the bonding layer 70 formed on the back surface 12a of the ceramic phosphor 10. That is, the protruding portions 71b, 72b, 73b of the bonding layer 70 are formed on the reflective layer 25, and the peripheral portions 71a, 72a, 73a of the bonding layer 70 are formed on the exposed back surface 12a of the ceramic phosphor 10. Thus, the bonding layer 70 having the protruding portions 71b, 72b, 73b and the peripheral portions 71a, 72a, 73a can be formed by utilizing the shape of the reflective layer 25, so that the thermal conductivity between the ceramic phosphor 10 and the heat dissipation member 40 can be easily improved.

[0065] In addition, according to the soldering wavelength conversion member 1c of the present embodiment, the bonding layer 70 covering both the back surface 12 of the ceramic phosphor 10 and the reflective layer 25 includes a bonding film 72 for soldering the ceramic phosphor 10 to the heat dissipation member 40, and a bonding film 71 disposed between the ceramic phosphor 10 and the bonding film 72. The bonding film 71 improves the adhesion between the ceramic phosphor 10 and the bonding film 72, and thus can improve the bonding strength between the ceramic phosphor 10 and the heat dissipation member 40 by soldering. Thus, poor bonding between the ceramic phosphor 10 and the heat dissipation member 40 can be suppressed.

[0066] <Fourth embodiment>

[0067] Figure 8 It is a cross-sectional view of a light source device 5d including a wavelength conversion device 6d in the fourth embodiment. Fig. 9 1d is a cross-sectional view of a wavelength conversion member for soldering according to the present embodiment. The wavelength conversion member for soldering 1d provided in the wavelength conversion device 6d of the present embodiment is different from the wavelength conversion member for soldering 1c ( Figure 7 ) is different in that the protruding portion and the peripheral portion are connected in each of the adhesion film 81, the bonding film 82 and the solder wetting film 83.

[0068] The wavelength conversion member 1d for soldering of the present embodiment includes a ceramic phosphor 10, a reflective layer 25, and a bonding layer 80. The bonding layer 80 is composed of one or more films that directly cover both the exposed back surface 12a of the back surface 12 of the ceramic phosphor 10 and the reflective layer 25. In the present embodiment, the bonding layer 80 includes a bonding film 81, a bonding film 82, and a solder wetting film 83.

[0069] The bonding film 81 is formed of chromium (Cr) or titanium (Ti). In the present embodiment, the film thickness of the bonding film 81 is greater than or equal to 10 nm and less than or equal to 500 nm, and the bonding film 81 includes an outer peripheral portion 71a, a protruding portion 71b, and a connecting portion 81c connecting the outer peripheral portion 71a and the protruding portion 71b on the side of the reflective layer 25. The bonding film 81 improves the adhesion between the reflective layer 25 and the bonding film 82 and the adhesion between the ceramic phosphor 10 and the bonding film 82.

[0070] The bonding film 82 is formed of a material containing nickel (Ni) as a main component. The bonding film 82 includes an outer peripheral portion 72a, a protruding portion 72b, and a connecting portion 82c formed along the connecting portion 81c of the adhesion film 81 and connecting the outer peripheral portion 72a and the protruding portion 72b. The bonding film 82 reacts with the solder wet film 83 to bond the ceramic phosphor 10 and the solder wet film 83.

[0071] The solder wetting film 83 is formed of gold (Au) and includes a peripheral portion 73a, a protruding portion 73b, and a connecting portion 83c formed along the connecting portion 82c of the bonding film 82 and connecting the peripheral portion 73a and the protruding portion 73b. The solder wetting film 83 improves solder wettability of the ceramic phosphor 10.

[0072] Thus, in the present embodiment, the bonding layer 80 has the protrusions 71b, 72b, 73b protruding relative to the peripheral portions 71a, 72a, 73a at the center of the surface 85 on the side opposite to the surface 84 on the side directly covering both the back surface 12a of the ceramic phosphor 10 and the reflective layer 25. The protrusions 71b, 72b, 73b are formed to cover the reflective layer 25.

[0073] According to the above-described soldering wavelength conversion member 1d of the present embodiment, when the ceramic phosphor 10 and the heat dissipation member 40 are soldered via the bonding layer 80, the voids contained in the solder between the protrusion 73b and the heat dissipation member 40 move together with the solder from between the protrusion 73b and the heat dissipation member 40 to between the outer peripheral portion 73a and the heat dissipation member 40. As a result, the number of voids between the protrusion 73b and the heat dissipation member 40 decreases, and thus the thermal conductivity between the ceramic phosphor 10 and the heat dissipation member 40 can be improved.

[0074] <Modification of this embodiment>

[0075] The present invention is not limited to the above-described embodiment, and can be implemented in various forms within the scope not departing from the gist of the present invention. For example, the present invention can be modified as follows.

[0076] [Modification 1]

[0077] In the first, third and fourth embodiments, the bonding layer has three films. In the second embodiment, the bonding layer has four films. However, the number of films forming the bonding layer is not limited thereto, and it may have one film or two films, or may have five or more films. In these cases, the bonding layer only needs to have a protrusion protruding relative to the periphery at the center of the surface on the side opposite to the surface on the side of the back surface 12 of the ceramic phosphor 10 and at least the side of the reflective layer in the reflective layer. As a result, when the ceramic phosphor 10 and the heat dissipation component 40 are brazed, the number of gaps between the protrusion and the heat dissipation component 40 is reduced, thereby improving the thermal conductivity between the ceramic phosphor 10 and the heat dissipation component 40.

[0078] [Modification 2]

[0079] In the third and fourth embodiments, the protrusion in the bonding layer covers the reflective layer. However, the shape of the protrusion is not limited thereto. The protrusion and the peripheral portion may be formed in such a manner that the reflective layer is covered by the protrusion and the peripheral portion, or the peripheral portion may be formed on the outside of the protrusion formed in such a manner that the reflective layer and the exposed back surface of the ceramic phosphor are covered. In this case, when the ceramic phosphor 10 and the heat dissipation component 40 are brazed, the number of gaps between the protrusion and the heat dissipation component 40 is reduced, thereby also being able to improve the thermal conductivity between the ceramic phosphor 10 and the heat dissipation component 40.

[0080] [Variation 3]

[0081] In the first embodiment, the bonding film 33 is formed of a material having nickel (Ni) as a main component. However, the composition of the bonding film 33 in the first embodiment is not limited thereto. At least one of palladium, platinum, molybdenum, and tungsten may be used as a main component. In this case, the amount of components of the bonding layer 30 dissolved in the solder can be suppressed, thereby suppressing poor bonding between the ceramic phosphor 10 and the heat dissipation member 40.

[0082] [Variation 4]

[0083] In the above embodiment, the reflective layer has three films, but the reflective layer may have only one film or may have two or four or more films.

[0084] [Variation 5]

[0085] For the bonding layer, the protrusion and the peripheral portion may be connected as in the first and second embodiments, the protrusion and the peripheral portion may be cut off as in the third embodiment, or the protrusion and the peripheral portion may be connected via a connecting portion as in the fourth embodiment.

[0086] [Variation 6]

[0087] In the second embodiment, the third embodiment, and the fourth embodiment, the joining layer has a solder wet film, but it is not necessary to have a solder wet film.

[0088] The above is based on the implementation mode and the variation example to illustrate the present scheme, but the implementation mode of the above scheme is to facilitate the understanding of the present scheme, rather than to limit the present scheme. The present scheme can be changed and improved without departing from its purpose and claims, and the present scheme includes its equivalents. In addition, if its technical features are not described as essential features in this specification, they can be appropriately deleted.

[0089] Description of Reference Numerals

[0090] 1a, 1b, 1c, 1d, wavelength conversion member for soldering; 6a, 6b, 6c, 6d, wavelength conversion device; 5a, 5b, 5c, 5d, light source device; 7, light source; 10, ceramic phosphor; 11, incident surface; 12, 12a, back surface; 20, 25, reflection layer; 21, high reflection film; 22, reflection film; 23, lower surface; 30, 60, 70, 80, bonding layer; 31, protective film; 32, 71, 81, sealing film; 33, 72, 82, bonding film; 34, 74, 84, bonding layer The surface of the bonding layer on the side covering the reflective layer; 35, 35a, 35b, 75, 85, the surface of the bonding layer on the opposite side to the surface covering the reflective layer; 36, 38a, 71a, 72a, 73a, the peripheral portion; 37, 38b, 71b, 72b, 73b, the protrusion; 38, 73, 83, the solder wetting film; 40, the heat dissipation component; 41, the main surface; 50, the solder layer; 51, the central portion; 52, the recessed portion; 81c, 82c, 83c, the connecting portion; L1, L2, the light; V1, the gap.

Claims

1. A wavelength conversion member for brazing, wherein: The wavelength conversion component for soldering comprises: a ceramic phosphor that converts the wavelength of light incident from the incident surface; a reflective layer disposed on the back surface of the ceramic phosphor on the side opposite to the incident surface, covering a portion of the back surface; and a bonding layer covering the back surface of the ceramic phosphor and the reflecting layer, the bonding layer comprising: a bonding film; and a sealing film made of chromium or titanium, the sealing film being arranged between the ceramic phosphor and the bonding film so that the ceramic phosphor and the bonding film are tightly bonded, The bonding layer has a central portion and a peripheral portion on a surface opposite to the surface covering the back surface and the reflective layer, and the central portion has a protruding portion protruding relative to the peripheral portion. The bonding layer directly covers both the exposed surface of the back surface of the ceramic phosphor and the reflective layer, The protrusion in the bonding layer covers the reflective layer.

2. A wavelength conversion member for brazing, wherein: The wavelength conversion component for soldering comprises: a ceramic phosphor that converts the wavelength of light incident from the incident surface; A reflective layer, which is disposed on the back side of the ceramic phosphor opposite to the incident surface, and covers the entire back side; as well as a bonding layer, which is composed of one or more films and covers the reflective layer, The bonding layer has a central portion and a peripheral portion on a surface opposite to the surface covering the reflective layer, and the central portion has a protruding portion that protrudes relative to the peripheral portion.

3. The wavelength conversion member for soldering according to claim 1 or 2, wherein: The film constituting the surface of the bonding layer opposite to the surface covering at least the reflecting layer of the back surface and the reflecting layer contains at least one of nickel, palladium, platinum, molybdenum, and tungsten as a main component.

4. A wavelength conversion device, wherein: The wavelength conversion device has: The wavelength conversion member for brazing according to any one of claims 1 to 3; a heat dissipation member that releases heat of the ceramic phosphor to the outside; and a solder layer provided between the bonding layer and the heat dissipation member to bond the soldering wavelength conversion member and the heat dissipation member together; The solder layer has a recessed portion surrounding the protruding portion of the bonding layer.

5. A light source device, wherein: The light source device has: The wavelength conversion device according to claim 4; and A light source irradiates light toward the ceramic phosphor.

Images