Fluorescent glass and phase change VC integrated structure for laser illumination and preparation

Abstract

The invention discloses a fluorescent glass and phase change VC integrated structure for laser illumination and preparation. The structure comprises a vapor chamber, the vapor chamber is internally provided with a sealed cavity, and the sealed cavity is filled with a phase change heat transfer material; a cylinder array formed by a plurality of cylinders is distributed on the surface of the vapor chamber; fluorescent glass layers are arranged on the surface of each column body and in gaps between the column bodies; the fluorescent glass layer is connected with the column body in a sintering mode. The inorganic fluorescent layer and the ultra-thin phase change vapor chamber are integrally designed in a sintering manner, so that the thermal resistance from a laser incident surface to a heat dissipation surface can be reduced, and the heat accumulation of the fluorescent converter can be effectively avoided. On the whole, the key point of the design is to enhance the efficient heat dissipation and stability of the fluorescence converter, and the development of the laser illumination technology can be accelerated.

Description

Technical Field

[0001] The invention relates to laser lighting components and manufacturing processes thereof, and in particular to an integrated structure of fluorescent glass and phase-change VC for laser lighting and its preparation. Background Art

[0002] Laser lighting has attracted extensive attention due to its high power density, high electro-optical efficiency and long lifetime, and is considered a promising candidate for the next generation of high-power lighting.

[0003] Laser diodes (LD) can maintain high photoelectric efficiency under high power conditions, which is far superior to light-emitting diodes (LEDs). However, the laser energy density is extremely high, and traditional silicone-type fluorescent components (PIS) are prone to heat accumulation due to poor thermal conductivity. Under high-power blue laser irradiation, severe heat accumulation can easily lead to carbonization of silicone. Compared with traditional silicone resin materials, fluorescent components such as fluorescent glass and fluorescent ceramics have better thermal conductivity and high stability without carbonization at high temperatures, showing high application value in the field of high-power laser-driven white light illumination.

[0004] In laser lighting, due to the high energy density of LD, phosphor converters equipped with LD tend to reach high temperatures in local areas, resulting in local thermal quenching. Due to the poor heat transfer capacity of fluorescent glass, heat transfer from the top surface to the bottom substrate is challenging, which severely limits the lighting performance. The problem of heat accumulation under normal operation and the energy consumption problem during the production process are key issues that laser lighting urgently needs to solve.

[0005] In addition, the traditional sintering process currently used in the manufacture of fluorescent components has defects such as slow sintering speed, high energy consumption, long production cycle and limited microstructure fineness. In comparison, the rapid sintering process has significant advantages in sintering speed, energy efficiency, microstructure fineness and production flexibility. Its efficient sintering process not only saves energy and reduces manufacturing costs, but also shortens the production cycle and improves production efficiency. Summary of the invention

[0006] The purpose of the present invention is to overcome the above-mentioned shortcomings and deficiencies of the prior art and to provide an integrated structure and preparation of fluorescent glass and phase change VC for laser lighting.

[0007] The integrated structure of the fluorescent glass and the phase-change VC of the present invention has the characteristic of rapidly dispersing the heat generated by the fluorescent element to avoid heat accumulation, and improves the defect that the traditional silicon-based fluorescent converter will carbonize and fail at high temperature.

[0008] When a high-power laser irradiates the fluorescent glass and generates a large amount of heat, the integrated structure of the fluorescent glass and the phase-change VC of the present invention can realize the release of heat from the evaporation heat source to the condensation point through the circulating phase change process of the cooling liquid in the low-vacuum cavity of the heat spreader, and quickly transfer the heat from the fluorescent element to the heat dissipation substrate with the help of the large-area heat spreader.

[0009] The present invention is achieved through the following technical solutions: A fluorescent glass and phase-change VC integrated structure for laser lighting, comprising a heat spreader 3, wherein the heat spreader 3 has a sealed cavity 4, and the sealed cavity 4 is filled with a phase-change heat transfer material; The surface of the heat spreader 3 is covered with a column array consisting of a plurality of columns 2; a fluorescent glass layer 1 is provided on the surface of each column 2 and in the gaps between the columns 2; the fluorescent glass layer 1 and the columns 2 are connected by sintering.

[0010] A heat dissipation substrate 5 is disposed on the back of the heat spreader 3 .

[0011] The heat spreader 3 is in surface contact with the heat dissipation substrate 5 .

[0012] The heat spreader 3 and the column 2 are integrally formed.

[0013] The heat spreader 3 and the column 2 are made of copper.

[0014] The phase change temperature of phase change heat transfer materials is between 20°C and 30°C, the latent heat value is between 50 J / g and 300 J / g, and the thermal conductivity is between 0.8 W / (m·K) and 1 W / (m·K).

[0015] The heat dissipation substrate is a fin structure, the heat dissipation fins and the heat spreader must be directly integrated and connected, and the area of ​​the heat dissipation substrate must be equal to the area of ​​the heat spreader.

[0016] The inner wall of the heat spreader sealed cavity 4 has a microstructure, and the whole is a two-phase fluid device formed by injecting phase change material into a container covered with microstructures. The thickness of the heat spreader is between 0.5mm and 1mm.

[0017] A method for sintering fluorescent glass on the surface of the column and the gap between the columns comprises the following steps: Step S1: adding fluorescent powder, glass powder and organic solvent into a container according to a mass ratio and preliminarily mixing them to obtain fluorescent glass slurry; Step S2: placing the fluorescent glass slurry and the container in a warm water environment (30-60° C.), and using a magnetic stirrer to stir the fluorescent glass slurry in a water bath environment until the fluorescent glass slurry becomes a paste without obvious granularity; Step S3: coating or filling the fully mixed fluorescent glass slurry on the column array on the surface of the vapor chamber 3, that is, coating on the surface of each column 2, and filling in the gaps between the columns 2; Step S4: Use a constant temperature heating table to heat and cure the fluorescent glass slurry to increase the bonding strength between the fluorescent glass slurry and the column 2. After the fluorescent glass slurry is heated and cured, it is placed in a Joule heating device together with the heat spreader 3 to heat the fluorescent glass so that it is quickly sintered on the surface of the column 2 and in the gaps between the columns 2.

[0018] In step S1, the phosphor and the glass powder are mixed in a mass ratio of 1:1; the organic solvent is composed of pine alcohol and ethyl cellulose in a mass ratio of 97:3.

[0019] In step S1, the phosphor comprises YAG, YAGG, GdYAG or LSN.

[0020] The water bath environment in step S2 refers to a temperature of 70-80° C. and a stirring time of 20-30 minutes.

[0021] Step S4: the Joule heating device comprises a carbon graphite felt 6; the carbon graphite felt 6 is suspended and attached to two base edges of the carbon graphite felt 6 through silver paste and a conductive copper tape 7; The silver paste is used as a conductive connection between the carbon graphite felt 6 and the conductive copper tape; the conductive copper tape on one side is used as the positive electrode 9, and the conductive copper on the other side is used as the negative electrode 8; the applied current is 10-30A, the temperature drop rate is about 6×10³ K / min, and the sintering time is less than 20s.

[0022] Compared with the prior art, the present invention has the following advantages and effects: The present invention can solve the problem of heat accumulation of fluorescent elements under high-power laser irradiation by an integrated design of an inorganic fluorescent layer prepared by a rapid sintering process based on Joule heat, a phase change heat spreader and an optimized heat dissipation structure.

[0023] The present invention adopts inorganic glass as the fluorescent packaging material, which can effectively avoid the high-temperature carbonization failure problem that may occur in traditional silica gel materials and improve the thermal conductivity of the fluorescent element.

[0024] The present invention adopts an ultrafast sintering process based on Joule heat to sinter the fluorescent material on a column array distributed on the surface of the heat spreader, which can not only improve the production efficiency of the components in the manufacturing process, but also reduce the production cost by saving energy expenses.

[0025] The present invention uses a sintering method to integrate the inorganic fluorescent layer with the ultra-thin phase change heat sink, which can reduce the thermal resistance from the laser incident surface to the heat dissipation surface and effectively avoid heat accumulation in the fluorescent converter. Overall, this design focuses on enhancing the efficient heat dissipation and stability of the fluorescent converter, which can accelerate the development of laser lighting technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic cross-sectional structure diagram of the integrated structure of fluorescent glass and phase-change VC for laser lighting of the present invention.

[0027] Figure 2 It is a manufacturing process flow chart of the integrated structure of fluorescent glass and phase-change VC for laser lighting of the present invention.

[0028] Figure 3 It is a schematic diagram of the carbon graphite felt in the Joule heating device of the present invention. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below in conjunction with specific embodiments.

[0030] like Figure 1-3 As shown, the present invention discloses an integrated structure of fluorescent glass and phase-change VC for laser lighting, including a heat spreader 3, wherein the heat spreader 3 has a sealed cavity 4, and the sealed cavity 4 is filled with a phase-change heat transfer material; The surface of the heat spreader 3 is covered with a column array consisting of a plurality of columns 2; a fluorescent glass layer 1 is provided on the surface of each column 2 and in the gaps between the columns 2; the fluorescent glass layer 1 and the columns 2 are connected by sintering.

[0031] The back of the vapor chamber 3 is provided with a heat dissipation substrate 5. The heat dissipation substrate 5 is a copper rectangular heat dissipation fin, which is used to conduct, radiate and convect the heat transmitted by the vapor chamber 3 to the surrounding environment to achieve efficient heat dissipation. In order to ensure the heat dissipation effect and the integration effect of the fluorescent glass and the phase change VC, the heat dissipation substrate 5 is directly connected to the vapor chamber 3 and the area of ​​the heat dissipation substrate must be equal to the area of ​​the vapor chamber.

[0032] The heat spreader 3 is in surface contact with the heat dissipation substrate 5 .

[0033] The heat spreader 3 and the column 2 are integrally formed.

[0034] The heat spreader 3 and the column 2 are made of copper.

[0035] The phase change temperature of phase change heat transfer materials is between 20°C and 30°C, the latent heat value is between 50 J / g and 300 J / g, and the thermal conductivity is between 0.8 W / (m·K) and 1 W / (m·K).

[0036] The heat dissipation substrate is a fin structure, the heat dissipation fins and the heat spreader must be directly integrated and connected, and the area of ​​the heat dissipation substrate must be equal to the area of ​​the heat spreader.

[0037] The inner wall of the heat spreader sealed cavity 4 has a microstructure, and the whole is a two-phase fluid device formed by injecting phase change material into a container covered with microstructures. The thickness of the heat spreader is between 0.5mm and 1mm.

[0038] The present invention directly connects the heat dissipation substrate of the fluorescent element to a heat spreader with phase change material, which shortens the heat transfer channel on the one hand, and quickly disperses the heat generated by the fluorescent element through phase change heat dissipation on the other hand, which can greatly improve the heat dissipation capacity of the laser lighting element.

[0039] During the sintering process of the fluorescent glass, a rapid high-temperature sintering technology based on Joule heat was used to sinter the phosphor and glass powder directly to the microstructure (copper column array) on the surface of the heat sink shell in less than 20 seconds. Compared with the traditional sintering process, it greatly improves the sintering efficiency and reduces energy consumption.

[0040] The method of sintering the fluorescent glass on the surface of the column and the gap between the columns can be achieved by the following steps: The terpineol and ethyl cellulose were weighed in a mass ratio of 97:3 using a weighing table, and stirred continuously for 30 minutes in an 80° C. water bath using a magnetic stirrer until the ethyl cellulose was completely dissolved.

[0041] The phosphor and glass powder were weighed in a weight ratio of 4:6 using a weighing table, and were fully mixed with the prepared organic carrier at a ratio of solvent to solute of 3:7 at 80°C.

[0042] The mixed slurry is fully stirred on a magnetic stirrer until the slurry becomes a paste without obvious granularity. The fully mixed fluorescent glass slurry is applied to the column array of the heat spreader shell, and the fluorescent glass is prepared by blade coating method. The height of the scraper is set, and then the coating is completed by a scraper.

[0043] The fluorescent glass is heated and cured at 150°C for about 15 minutes using a constant temperature heating table. The pinolene evaporates quickly while the ethyl cellulose does not decompose, thereby maintaining the bonding effect, so that the fluorescent glass is firmly bonded to the copper pillars on the heat spreader column array. Then, it is placed in a Joule heating device. By adjusting the incident current (20-30A) supplemented by the power supply to control the heating rate and temperature of the Joule heating device, the fluorescent glass is directly sintered to the array copper pillars of the heat spreader, and the control time is less than 20 seconds. Finally, a heat dissipation substrate 5 containing heat dissipation fins is connected after the sintered fluorescent element to obtain the integrated structure design of fluorescent glass and phase change VC for laser lighting described in the present invention.

[0044] The present invention greatly improves the heat dissipation efficiency of the fluorescent element under high power use, and overcomes the defects of poor heat transfer capacity of the traditional fluorescent element and low heat transfer efficiency from the top surface to the bottom substrate.

[0045] The present invention adopts inorganic glass as the packaging material, and can still maintain stable performance at high temperature.

[0046] The ultrafast sintering process adopted in the manufacturing process of the present invention improves the production efficiency of the components and saves energy.

[0047] The present invention needs to be used in combination with a light source, and the fluorescent converter is combined with a laser in the form of a coating or a package. The laser is one or more of a gas laser, a solid laser, a semiconductor laser, and a fiber laser.

[0048] As described above, the present invention can be better implemented.

[0049] The implementation methods of the present invention are not limited to the above-mentioned embodiments, and any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principles of the present invention shall be equivalent replacement methods and shall be included in the protection scope of the present invention.

Claims

1. An integrated structure of fluorescent glass and phase-change VC for laser lighting, characterized in that It comprises a vapor chamber (3), wherein the vapor chamber (3) has a sealed cavity (4), and the sealed cavity (4) is filled with a phase change heat transfer material; The surface of the heat spreader (3) is covered with a column array composed of a plurality of columns (2); a fluorescent glass layer 1 is provided on the surface of each column (2) and in the gaps between the columns (2); the fluorescent glass layer 1 and the columns (2) are connected by sintering.

2. The integrated structure of fluorescent glass and phase change VC for laser lighting according to claim 1, characterized in that: A heat dissipation substrate (5) is provided on the back side of the heat diffusion plate (3).

3. The integrated structure of fluorescent glass and phase change VC for laser lighting according to claim 2, characterized in that: The heat spreader (3) is in surface contact with the heat dissipation substrate (5).

4. The integrated structure of fluorescent glass and phase-change VC for laser lighting according to claim 2, characterized in that: The heat spreader (3) and the column (2) are integrally formed.

5. The integrated structure of fluorescent glass and phase-change VC for laser lighting according to claim 1, characterized in that: The heat spreader (3) and the column (2) are made of copper; the inner wall of the sealed cavity (4) is covered with protruding microstructures.

6. A method for sintering fluorescent glass on the surface of the column and the gap between the columns as claimed in claim 1, characterized in that The steps include: Step S1: adding fluorescent powder, glass powder and organic solvent into a container according to a mass ratio and preliminarily mixing them to obtain fluorescent glass slurry; Step S2: placing the fluorescent glass slurry and the container in a warm water environment, and using a magnetic stirrer to stir the fluorescent glass slurry in a water bath environment until the fluorescent glass slurry becomes a paste; Step S3: coating or filling the fully mixed fluorescent glass slurry on the column array on the surface of the heat spreader (3), that is, coating the surface of each column (2) and filling the gaps between the columns (2); Step S4: The fluorescent glass slurry is heated and solidified to increase the bonding strength between the fluorescent glass slurry and the column (2). After the fluorescent glass slurry is heated and solidified, it is placed in a Joule heating device together with the heat spreader (3) for heating, so that the fluorescent glass is quickly sintered on the surface of the column (2) and in the gaps between the columns (2).

7. The method of sintering fluorescent glass on the surface of the column and the gap between the columns in claim 1 according to claim 6, characterized in that: In step S1, the phosphor and the glass powder are mixed in a mass ratio of 1:1; the organic solvent is composed of pine alcohol and ethyl cellulose in a mass ratio of 97:

3.

8. The method of sintering fluorescent glass on the surface of the column and the gap between the columns in claim 1 according to claim 7, characterized in that: In step S1, the phosphor comprises YAG, YAGG, GdYAG or LSN.

9. The method of sintering fluorescent glass on the surface of the column and the gap between the columns in claim 1 according to claim 6, characterized in that: The water bath environment in step S2 refers to a temperature of 70-80° C. and a stirring time of 20-30 minutes.

10. The method of sintering fluorescent glass on the surface of the column and the gap between the columns in claim 1 according to claim 6, characterized in that: Step S4: the Joule heating device comprises a carbon graphite felt (6); the carbon graphite felt (6) is suspended and attached to two base edges of the carbon graphite felt (6) through silver paste and a conductive copper tape (7); The silver paste serves as a conductive connection between the carbon graphite felt (6) and the conductive copper tape; the conductive copper tape on one side serves as a positive electrode (9), and the conductive copper on the other side serves as a negative electrode (8); a current of 10-30A is applied, the temperature reduction rate is about 6×10³ K / min, and the sintering time is less than 20s.

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