Wavelength conversion device and light-emitting device

Abstract

The embodiment of the utility model provides a wavelength conversion device, which comprises a metal substrate, a first bonding layer, a ceramic heat dissipation substrate, a metallization layer, a second bonding layer, a reflecting layer and a fluorescent ceramic layer, and is characterized in that the first bonding layer is arranged on the surface of the metal substrate; the ceramic heat dissipation substrate is arranged on the surface of the first bonding layer; the metalized layer is arranged on the surface of the ceramic heat dissipation substrate, the second bonding layer is arranged on the surface of the metalized layer, the reflecting layer is arranged on the surface of the second bonding layer, the fluorescent ceramic layer is arranged on the surface of the reflecting layer, and the percentage of the difference value between the thermal expansion coefficient of the fluorescent ceramic layer and the thermal expansion coefficient of the ceramic heat dissipation substrate is 0-60%. The ceramic heat dissipation substrate can achieve a high heat conduction effect and also can solve the problem of device failure caused by large thermal expansion coefficient difference between the fluorescent ceramic layer and the metal substrate, the device structure and the preparation process are simple, and the long-term reliability and the service life of the wavelength conversion device can be effectively improved. In addition, the embodiment of the utility model further provides light-emitting equipment.

Description

Technical Field

[0001] This application relates to the field of light source technology, specifically to a wavelength conversion device and a light-emitting device. Background Technology

[0002] Currently, laser-fluorescent conversion light sources are widely used in LED lighting, stage lighting, vehicle lighting, searchlights, and other equipment, offering advantages such as high brightness and high-temperature stability. Among these, the wavelength conversion device is the core component of the laser-fluorescent conversion light source, and its performance plays a decisive role in the quality of the light source.

[0003] Currently, wavelength conversion devices typically consist of a metal substrate layer, an adhesive layer, a reflective layer, and a light-emitting layer stacked sequentially. When a high-power laser irradiates the wavelength conversion device, the phosphor layer generates a significant amount of heat. If this heat cannot be dissipated in time, the phosphor layer temperature will rise. Furthermore, if there is a large mismatch in the thermal expansion coefficients between the layers of the wavelength conversion device, the parts with larger thermal expansion coefficients are prone to expansion and contraction under thermal cycling conditions, which can easily lead to stress and cracking at the interfaces. Therefore, poor heat dissipation and large differences in thermal expansion coefficients directly affect fluorescence efficiency and device lifespan.

[0004] Currently, the commonly used light-emitting layer in wavelength conversion devices is a fluorescent ceramic layer. Among fluorescent ceramics, the coefficient of thermal expansion of the multiphase fluorescent ceramic Al2O3-YAG:Ce is 4.6*10-6 / ℃, while the coefficient of thermal expansion of the single-phase fluorescent ceramic YAG:Ce is 8.0*10-6 / ℃. However, the coefficient of thermal expansion of the metal material in the metal substrate layer is larger. For example, the coefficient of thermal expansion of the copper metal substrate is about 16.5*10-6 / ℃. The difference in the coefficient of thermal expansion between the fluorescent ceramic and the metal heat dissipation substrate is very large. When the operating temperature rises or falls, the metal layer will expand or contract more easily than the fluorescent ceramic layer, which will lead to the generation of adhesive layer stress and cracks, affect the heat dissipation channel, generate heat accumulation, and reduce the reliability and service life of the device. Utility Model Content

[0005] The purpose of this application is to provide a wavelength conversion device and a light emission device to improve the above-mentioned problems.

[0006] In a first aspect, embodiments of this application provide a wavelength conversion device, including a metal substrate, a first adhesive layer, a ceramic heat dissipation substrate, a metallization layer, a second adhesive layer, a reflective layer, and a fluorescent ceramic layer. The first adhesive layer is disposed on the surface of the metal substrate; the ceramic heat dissipation substrate is disposed on the surface of the first adhesive layer away from the metal substrate; the metallization layer is disposed at least on the surface of the ceramic heat dissipation substrate away from the first adhesive layer; the second adhesive layer is disposed on the surface of the metallization layer away from the ceramic heat dissipation substrate; the reflective layer is disposed on the surface of the second adhesive layer away from the ceramic heat dissipation substrate; and the fluorescent ceramic layer is disposed on the surface of the reflective layer away from the second adhesive layer. The percentage difference between the coefficient of thermal expansion of the fluorescent ceramic layer and the coefficient of thermal expansion of the ceramic heat dissipation substrate is 0-60%.

[0007] In one embodiment, the metallization layer is a gold layer, a copper layer, or a nickel layer.

[0008] In one embodiment, the ceramic heat dissipation substrate is one of silicon carbide, aluminum nitride, and aluminum oxide.

[0009] In one embodiment, the first adhesive layer is one of a solder layer, a sintered silver layer, or a gold paste layer.

[0010] In one embodiment, the reflective layer is a sintered silver layer or a silver-plated layer.

[0011] In one embodiment, the thickness of the reflective layer is 10μm-30μm.

[0012] In one embodiment, the second adhesive layer is either a sintered silver layer or a gold adhesive layer.

[0013] In one embodiment, the thickness of the second adhesive layer is 10μm-20μm.

[0014] In one embodiment, the fluorescent ceramic layer is a Ce:YAG or Ce:LuAG single-phase ceramic, or the fluorescent ceramic layer is an Al2O3-Ce:YAG or Al2O3-Ce:LuAG multiphase ceramic.

[0015] Secondly, embodiments of this application also provide a light-emitting device, which includes a laser light source and the aforementioned wavelength conversion device. The laser light source emits excitation light to excite the wavelength conversion device to emit laser light.

[0016] The wavelength conversion device and light-emitting device provided in this application have a highly matched ceramic heat dissipation substrate disposed between the metal substrate and the fluorescent ceramic layer. This ensures that the difference in the thermal expansion coefficient between the fluorescent ceramic layer and the ceramic heat dissipation substrate is 0-60%. The ceramic heat dissipation substrate achieves high thermal conductivity and solves the problem of device failure caused by the large difference in thermal expansion coefficients between the fluorescent ceramic layer and the metal substrate. The device structure and fabrication process are simple, effectively improving the long-term reliability and service life of the wavelength conversion device. Simultaneously, by providing a metallization layer, the adhesion between the ceramic heat dissipation substrate and the reflective layer is increased, preventing the reflective layer and the fluorescent ceramic layer from detaching.

[0017] These or other aspects of this application will become more apparent in the following description of the embodiments. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of a wavelength conversion device in the prior art shown in this application.

[0020] Figure 2 This is a schematic diagram of the structure of a wavelength conversion device provided in an embodiment of this application.

[0021] Figure 3 This is a schematic diagram of the structure of a light-emitting device provided in Embodiment 3 of this application. Detailed Implementation

[0022] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0023] Figure 1 A prior art wavelength conversion device is shown, comprising a fluorescent layer 1, a metal reflective layer 2, an adhesive layer 3, and a heat dissipation substrate 4 stacked sequentially from top to bottom. In wavelength conversion devices fabricated in this manner, the adhesion between layers and the matching of linear thermal expansion coefficients are unstable. Under thermal cycling conditions, the parts with larger thermal expansion coefficients are prone to expansion and contraction, easily leading to stress and cracking problems at the interfaces.

[0024] Based on this, the inventors of this application have proposed a wavelength conversion device and a light-emitting device. The present invention will be described in detail below with reference to specific embodiments.

[0025] Example 1

[0026] See Figure 2 This embodiment provides a wavelength conversion device 10, including a metal substrate 100, a first adhesive layer 200, a ceramic heat dissipation substrate 300, a metallization layer (not shown), a second adhesive layer 400, a reflective layer 500, and a fluorescent ceramic layer 600. The first adhesive layer 200 is disposed on the surface of the metal substrate 100; the ceramic heat dissipation substrate 300 is disposed on the surface of the first adhesive layer 200 away from the metal substrate 100; the metallization layer may be disposed at least on the surface of the ceramic heat dissipation substrate 300 away from the first adhesive layer 200; the second adhesive layer 400 is disposed on the surface of the metallization layer away from the ceramic heat dissipation substrate 300; the reflective layer 500 is disposed on the surface of the second adhesive layer 400 away from the ceramic heat dissipation substrate 300; and the fluorescent ceramic layer 600 is disposed on the surface of the reflective layer 500 away from the second adhesive layer 400.

[0027] In this embodiment, the metal substrate 100 can be a copper substrate, which has good thermal conductivity. Furthermore, the coefficient of thermal expansion of copper is approximately 16.5*10⁻⁶ / ℃, which is close to the coefficient of thermal expansion of the ceramic heat dissipation substrate 300, allowing for compatibility. In other embodiments, the metal substrate 100 can also be made of other metal materials, such as an Al substrate; this embodiment does not limit this choice.

[0028] The first adhesive layer 200 is used to bond the metal substrate 100 and the ceramic heat dissipation substrate 300 together, while simultaneously conducting heat between the ceramic heat dissipation substrate 300 and the metal substrate 100. In some embodiments, the first adhesive layer 200 may be one of a solder layer, a sintered silver layer, or a gold paste layer. A solder layer can be formed by soldering with solder paste. The solder layer is a high-performance heat-conducting channel that can promptly transfer heat to the metal substrate 100 for dissipation. A sintered silver layer can be formed by sintering silver paste, and a gold paste layer can be formed by coating, plating, or sintering. Both sintered silver layers and gold paste layers have good thermal conductivity.

[0029] The ceramic heat dissipation substrate 300 is made of ceramic material. The difference between the thermal expansion coefficient of the ceramic material and the thermal expansion coefficient of the fluorescent ceramic layer is not large. Therefore, the ceramic heat dissipation substrate 300 can achieve high thermal conductivity and solve the problem of device failure caused by the large difference in thermal expansion coefficients between the fluorescent ceramic layer and the metal substrate. In this embodiment, the ceramic heat dissipation substrate 300 is disposed on the surface of the first adhesive layer 200 away from the metal substrate 100, that is, the metal substrate 100 and the ceramic heat dissipation substrate 300 are bonded into an integral structure by the first adhesive layer 200.

[0030] In some embodiments, the ceramic heat dissipation substrate 300 can be an AlN substrate, i.e., an aluminum nitride substrate. An aluminum nitride substrate is a ceramic substrate material formed by bonding aluminum and nitrogen atoms, and its coefficient of thermal expansion is 4.4 × 10⁻⁶. -6 / ℃ to 5.8×10 -6 / ℃. Furthermore, aluminum nitride substrates possess extremely high thermal conductivity, with a theoretical thermal conductivity reaching up to 320 W / (m·K) at room temperature. Simultaneously, aluminum nitride has a relatively low coefficient of linear expansion, similar to that of copper substrates.

[0031] In some embodiments, the ceramic heat dissipation substrate 300 can also be a silicon carbide (SiC) substrate, with a coefficient of thermal expansion of 4.0 × 10⁻⁶. -6 / ℃ to 4.5×10 -6 / ℃, which is close to the coefficient of thermal expansion of the fluorescent ceramic layer 600.

[0032] In some embodiments, the ceramic heat dissipation substrate 300 can also be an alumina substrate (Al2O3), with a coefficient of thermal expansion of 6.5 × 10⁻⁶. -6 / ℃ to 8.5×10 -6 / ℃, which is close to the coefficient of thermal expansion of the fluorescent ceramic layer 600.

[0033] To ensure that the thickness of the wavelength conversion device 10 is not excessive, the thickness of the ceramic heat sink substrate 300 can be set to be relatively thin. For example, in some embodiments, the thickness of the ceramic heat sink substrate 300 can be 0.25mm-0.5mm. At this thickness, the ceramic heat sink substrate 300 can maintain good structural strength while not being excessively thick. Of course, it is understood that in other embodiments, the thickness of the ceramic heat sink substrate 300 can also be other values, and this embodiment does not limit this.

[0034] A metallization layer can be disposed on the surface of the ceramic heat dissipation substrate 300 away from the first adhesive layer 200. The metallization layer can improve the wettability of the ceramic heat dissipation substrate 300 and better bond with the second adhesive layer 400 and the reflective layer 500. The metallization layer can be achieved, for example, by ion plating, vacuum evaporation, sputtering, or other methods on the surface of the ceramic heat dissipation substrate 300. It can also be achieved by plating, screen printing, etc., which are not limited in this embodiment. The metallization layer can be a gold layer, a copper layer, or a nickel layer, which are not limited in this embodiment. Gold, copper, and nickel layers all have good thermal conductivity, which can quickly dissipate heat while also bonding well with the second adhesive layer 400 and the reflective layer 500. By providing a metallization layer, the adhesion between the ceramic heat dissipation substrate 300 and the reflective layer 500 can be increased, preventing the reflective layer 500 and the fluorescent ceramic layer 600 from detaching.

[0035] In some embodiments, the metallization layer may also be disposed on the side surface of the ceramic heat dissipation substrate 300 near the first adhesive layer 200, and the disposal method may be the same as described above.

[0036] The reflective layer 500 is used to reflect the laser light converted by the fluorescent ceramic layer 600, and can also reflect the excitation light. Simultaneously, the reflective layer 500 also serves to tightly connect the ceramic heat sink substrate 300 and the fluorescent ceramic layer 600. Furthermore, the reflective layer 500 can quickly transfer some of the heat overflowing when the excitation light irradiates the fluorescent ceramic layer 600 to the ceramic heat sink substrate 300 and the metal substrate 100 for dissipation.

[0037] In this embodiment, the reflective layer 500 can be a sintered silver layer, formed by sintering a silver-containing paste. The thickness of the reflective layer 500 can be controlled by controlling the thickness of the silver-containing paste. The particle size of the silver particles in the silver-containing paste can be controlled between 1μm and 4μm. At this size, the silver particles result in a denser reflective layer 500 after sintering, reducing porosity and thus improving the reflective effect. The reflective layer 500 can also be a silver-plated layer, which can be formed on the surface of the fluorescent ceramic layer 600 by deposition.

[0038] In one embodiment, the thickness of the reflective layer 500 can be 10μm-30μm, for example, 15μm, 20μm, 25μm, etc. Of course, in other embodiments, the thickness of the reflective layer 500 can also be other values, and this embodiment does not limit this.

[0039] The second adhesive layer 400 is disposed between the ceramic heat dissipation substrate 300 and the reflective layer 500, and is used to connect the ceramic heat dissipation substrate 300 and the reflective layer 500. To improve the connection between the ceramic heat dissipation substrate 300 and the reflective layer 500, and to reduce the thermal resistance at the interlayer interface, in a more specific embodiment, the second adhesive layer 400 can also be a sintered silver layer, and is prepared in the same manner as the reflective layer 500. In other embodiments, the second adhesive layer can also be a gold paste layer, which can similarly improve the connection between the ceramic heat dissipation substrate 300 and the reflective layer 500, and reduce the thermal resistance at the interlayer interface; this embodiment does not limit this to a specific embodiment.

[0040] In one embodiment, the thickness of the second adhesive layer 400 can be 10μm-20μm, for example, 12μm, 15μm, 18μm, etc. Of course, in other embodiments, the thickness of the second adhesive layer 400 can also be other values, and this embodiment does not limit this. In other embodiments, the second adhesive layer 400 can also be formed by soldering, and this embodiment does not limit this.

[0041] The fluorescent ceramic layer 600 can be a Ce:YAG or Ce:LuAG single-phase ceramic, wherein the coefficient of thermal expansion of Ce:YAG single-phase ceramic is 7.8 × 10⁻⁶. -6 At ℃, the coefficient of thermal expansion of Ce:LuAG single-phase ceramic is 8.8×10⁻⁶. -6 / ℃. The fluorescent ceramic layer 600 can also be an Al2O3-Ce:YAG or Al2O3-Ce:LuAG multiphase ceramic. This embodiment does not specifically limit this. The thermal expansion coefficient of the Al2O3-Ce:YAG multiphase ceramic is affected by both alumina and Ce:YAG, and its thermal expansion coefficient is typically between that of single-phase alumina (6.5 × 10⁻⁶). -6 / ℃ to 8.5×10 -6 / ℃) and single-phase Ce:YAG (7.8×10 -6 The thermal expansion coefficient of Al2O3-Ce:LuAG multiphase ceramics is influenced by both alumina and Ce:LuAG, and its thermal expansion coefficient is typically between that of single-phase alumina (6.5 × 10⁻⁶ °C). -6 / ℃ to 8.5×10 -6 / ℃) and single-phase Ce:LuAG (8.8×10 -6 Between / ℃). The fluorescent ceramic layer 600 can convert the excitation light into a laser light under the excitation of the excitation light. In a more specific embodiment, the excitation light can be blue light, and the fluorescent ceramic layer 600 can convert the blue light into yellow fluorescence.

[0042] In this embodiment, the percentage difference between the thermal expansion coefficient of the fluorescent ceramic layer 600 and the thermal expansion coefficient of the ceramic heat dissipation substrate 300 is 0-60%. This percentage difference is the difference between the thermal expansion coefficients of the ceramic heat dissipation substrate 300 and the fluorescent ceramic layer 600, divided by the thermal expansion coefficient of the fluorescent ceramic layer 600. When the thermal expansion coefficients of the fluorescent ceramic layer 600 and the ceramic heat dissipation substrate 300 are within this range, the ceramic heat dissipation substrate 300 can form a transition between the fluorescent ceramic layer 600 and the metal substrate 100, avoiding excessive difference in thermal expansion coefficients between the fluorescent ceramic layer 600 and the metal substrate 100, which could lead to failure.

[0043] In some embodiments, the percentage difference between the coefficient of thermal expansion of the fluorescent ceramic layer 600 and the coefficient of thermal expansion of the ceramic heat dissipation substrate 300 can be 0-30%, 30%-60%, 20%-40%, etc.

[0044] In this embodiment, the wavelength conversion device 10 has a highly compatible ceramic heat dissipation substrate 300 disposed between the metal substrate 100 and the fluorescent ceramic layer 600. The ceramic heat dissipation substrate 300 not only achieves high thermal conductivity but also solves the problem of device failure caused by the large difference in thermal expansion coefficients between the fluorescent ceramic layer 600 and the metal substrate 100. The device structure and fabrication process are simple, which can effectively improve the long-term reliability and service life of the wavelength conversion device 10. At the same time, by providing a metallization layer, the adhesion between the ceramic heat dissipation substrate 300 and the reflective layer 500 can be increased, preventing the reflective layer 500 and the fluorescent ceramic layer 600 from falling off.

[0045] Specifically, the wavelength conversion device 10 described above can be manufactured in the following manner:

[0046] A fluorescent ceramic layer 600 is provided. One surface of the fluorescent ceramic layer 600 is polished to improve its adhesion to the reflective layer 500. A silver paste is prepared, comprising silver particles and an organic carrier. The silver particles can have a particle size of 1-4 μm, and the organic carrier can be selected from one or more of ethyl cellulose, terpineol, butylcarbohydrate, and butylcarbohydrate ester. The silver paste is brushed onto the polished surface of the fluorescent ceramic layer 600 to a thickness of 10-30 μm, for example, 20 μm. The brushed fluorescent ceramic layer 600 is then placed in a heating table or a forced-air drying oven at a temperature range of 70℃-100℃ for 10-20 minutes to allow excess organic carrier to evaporate.

[0047] An aluminum nitride substrate is provided as a ceramic heat dissipation substrate 300. One surface of the ceramic heat dissipation substrate 300 is polished, and then a metallization treatment is performed on the polished surface to form a metallization layer. The wettability of the metallization layer is higher than that of the ceramic heat dissipation substrate 300, making it easier to bond with the second adhesive layer 400. Silver paste with a thickness of 10-20 μm is brushed onto the surface of the metallization layer.

[0048] The surface of the fluorescent ceramic layer 600 coated with silver paste is stacked on the surface of the ceramic heat dissipation substrate 300 coated with silver paste. The entire device is then placed in a muffle furnace and sintered under pressure at a high temperature of 700℃-950℃ for 30 minutes to 3 hours, with a pressure of approximately 45 MPa. After sintering, the reflective layer 500 and the second adhesive layer 400 are formed. This results in the fluorescent ceramic layer 600 and the ceramic heat dissipation substrate 300 being interconnected.

[0049] Then, the ceramic heat dissipation substrate 300 and the metal substrate 100 are welded together with tin-based solder to form the first adhesive layer 200, thus obtaining the wavelength conversion device 10.

[0050] Example 2

[0051] Please continue reading. Figure 1 This embodiment provides a wavelength conversion device 10, which differs from the first embodiment in that the wavelength conversion device 10 is prepared in a different way. For the same parts, please refer to the content of the first embodiment, and this embodiment will not repeat them.

[0052] In this embodiment, the wavelength conversion device 10 can be fabricated in the following manner:

[0053] A fluorescent ceramic layer 600 is provided, and one surface of the fluorescent ceramic layer 600 is polished to improve its adhesion to the reflective layer 500. The reflective layer 500 is formed on the polished surface of the fluorescent ceramic layer 600 by vapor deposition.

[0054] An aluminum nitride substrate is provided as a ceramic heat dissipation substrate 300. One surface of the ceramic heat dissipation substrate 300 is polished, and then a metallization treatment is performed on the polished surface to form a metallization layer. The wettability of the metallization layer is higher than that of the ceramic heat dissipation substrate 300, making it easier to bond with the second adhesive layer 400. Silver paste with a thickness of 10-20 μm is brushed onto the surface of the metallization layer.

[0055] The side of the fluorescent ceramic layer 600 with the reflective layer 500 is stacked on the silver-painted surface of the ceramic heat sink substrate 300. The entire device is then placed in a muffle furnace and sintered at 300°C for 30 minutes to 3 hours under normal pressure (approximately 45 MPa). After sintering, the reflective layer 500 and the second adhesive layer 400 are formed. This results in the fluorescent ceramic layer 600 and the ceramic heat sink substrate 300 being interconnected.

[0056] Then, the ceramic heat dissipation substrate 300 and the metal substrate 100 are welded together with tin-based solder to form the first adhesive layer 200, thus obtaining the wavelength conversion device 10.

[0057] Example 3

[0058] See Figure 3 This embodiment provides a light-emitting device 1, which includes a laser light source 20 and a wavelength conversion device 10. The laser light source 20 emits excitation light to excite the wavelength conversion device 10 to emit laser light. The wavelength conversion device 10 can be any of the aforementioned embodiments. For details, please refer to the relevant content of the aforementioned embodiments.

[0059] The laser light source 20 can be, for example, a blue light source. In other embodiments, the laser light source 20 can also be a light source of other colors. This embodiment does not limit this.

[0060] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A wavelength conversion device, characterized in that, include: metal substrate; A first adhesive layer is disposed on the surface of the metal substrate; A ceramic heat dissipation substrate, wherein the ceramic heat dissipation substrate is disposed on the surface of the first adhesive layer away from the metal substrate; A metallization layer is provided at least on the surface of the ceramic heat dissipation substrate away from the first adhesive layer; A second adhesive layer is disposed on the surface of the metallization layer away from the ceramic heat dissipation substrate; A reflective layer is disposed on the surface of the second adhesive layer away from the ceramic heat dissipation substrate; as well as A fluorescent ceramic layer is disposed on the surface of the reflective layer away from the second adhesive layer; The percentage difference between the coefficient of thermal expansion of the fluorescent ceramic layer and the coefficient of thermal expansion of the ceramic heat dissipation substrate is 0-60%.

2. The wavelength conversion device according to claim 1, characterized in that, The metallization layer is a gold layer, a copper layer, or a nickel layer.

3. The wavelength conversion device according to claim 1, characterized in that, The ceramic heat dissipation substrate is one of silicon carbide, aluminum nitride, and aluminum oxide.

4. The wavelength conversion device according to claim 1, characterized in that, The first adhesive layer is one of a solder layer, a sintered silver layer, or a gold adhesive layer.

5. The wavelength conversion device according to claim 1, characterized in that, The reflective layer is a sintered silver layer or a silver-plated layer.

6. The wavelength conversion device according to claim 5, characterized in that, The thickness of the reflective layer is 10μm-30μm.

7. The wavelength conversion device according to claim 5, characterized in that, The second adhesive layer is either a sintered silver layer or a gold adhesive layer.

8. The wavelength conversion device according to claim 7, characterized in that, The thickness of the second adhesive layer is 10μm-20μm.

9. The wavelength conversion device according to claim 1, characterized in that, The fluorescent ceramic layer is a Ce:YAG or Ce:LuAG single-phase ceramic, or the fluorescent ceramic layer is an Al2O3-Ce:YAG or Al2O3-Ce:LuAG multiphase ceramic.

10. A light-emitting device, characterized in that, The light-emitting device includes a laser source and a wavelength conversion device as described in any one of claims 1-9, wherein the laser source emits excitation light to excite the wavelength conversion device to emit laser light.

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