High-reflectivity ceramic substrate and optical device

Abstract

The invention relates to the technical field of optical products, in particular to a high-reflectivity ceramic substrate and an optical device. According to the high-reflectivity ceramic substrate provided by the invention, through internal pore forming and sintering temperature control, the surface of a device has relatively high reflectivity, and the reflectivity is improved from conventional 85% to 95% or more, so that the effect of improving the utilization rate of light is achieved, and meanwhile, the problem of heat dissipation is solved; the optical device provided by the invention is manufactured by using the high-reflectivity ceramic substrate, can be directly used as a heat dissipation substrate, has extremely high temperature resistance, can be normally used in an environment of 1200 DEG C, has good insulativity which can reach 15KV / mm, and can be used as a heat dissipation substrate. The application defects of temperature difference resistance, complicated use and operation, influence on heat dissipation of light source devices and the like of diffuse reflection coatings and diffuse reflection films in the market are overcome or optimized.

Description

Technical Field

[0001] The present invention relates to the technical field of optical products, and in particular to a high-reflectivity ceramic substrate and an optical device. Background Art

[0002] Highly reflective materials are widely used in the field of optical products. The high reflectivity of the material surface can reuse light multiple times to improve the utilization rate of light energy. However, currently common high-reflective optical devices use secondary surface treatment methods, such as high-reflective coatings and high-reflective film materials. For example, in LED products, high-reflective coatings need to be sprayed or printed on the radiator before curing, and high-reflective film materials need to be cut according to the shape of the product before being bonded to the radiator; in addition, these two materials will affect the heat transfer of the product in actual application; and according to the development trend of LED, the power of the product will become higher and higher, and the temperature will also become higher and higher. The temperature resistance of the two materials, coatings and film materials, can no longer meet the application requirements.

[0003] It is of great significance to develop a high-reflectivity ceramic substrate and optical device that does not require secondary processing and has high light utilization and good temperature resistance and thermal conductivity. Summary of the invention

[0004] In view of the shortcomings of the prior art mentioned above, the present invention uses ceramic materials to make an integrally formed optical device. By making internal holes and controlling the sintering temperature, the device surface has a higher reflectivity, which is increased from the conventional 85% reflectivity to 95% and above, thereby improving the utilization rate of light and solving the heat dissipation problem.

[0005] To achieve the above-mentioned purpose and other related purposes, the present invention adopts the following technical solutions:

[0006] The first aspect of the present invention provides a high-reflectivity ceramic matrix, which is prepared from ceramic raw materials including the following parts by weight: 75 to 95 parts of aluminum oxide, 3 to 15 parts of sintering aids, 1 to 10 parts of organic matter and 0.8 to 1.2 parts of dispersant; the sintering aid is selected from a mixture of any one or more of silicon micropowder, zinc oxide, titanium dioxide, zirconium oxide, magnesium oxide, yttrium oxide, sodium bicarbonate, sodium carbonate, magnesium carbonate, calcium carbonate, barium carbonate and calcined talc; the organic matter is selected from a mixture of any one or more of starch, polymethyl methacrylate, polyvinyl alcohol, polypropylene and polyethylene glycol.

[0007] In some embodiments of the present invention, the sintering aid includes silicon micropowder, titanium dioxide, calcium carbonate and calcined talc.

[0008] In some embodiments of the present invention, the dispersant is polyacrylamide.

[0009] The second aspect of the present invention provides a method for preparing the above-mentioned high reflectivity ceramic substrate, comprising the following steps:

[0010] (1) preparing an organic substance solution;

[0011] (2) adding water, dispersant, alumina and sintering aid into a ball mill and performing a ball milling operation;

[0012] (3) adding the organic substance solution into the ball mill and performing secondary ball milling to obtain a slurry;

[0013] (4) preparing the slurry into a ceramic body;

[0014] (5) The ceramic body is placed in a sintering furnace for sintering to obtain a high reflectivity ceramic matrix.

[0015] In some embodiments of the present invention, in step (5), the sintering temperature is 1400-1600° C., and the sintering time is 1-12 hours.

[0016] A third aspect of the present invention provides an optical device comprising the above-mentioned high-reflectivity ceramic substrate.

[0017] In some embodiments of the present invention, it further includes a metal conductive layer disposed on the surface of the high reflectivity ceramic substrate, and a light-emitting element fixed on the high reflectivity ceramic substrate and forming a conductive path with the metal layer.

[0018] A fourth aspect of the present invention provides a method for preparing the above optical device, comprising the following steps:

[0019] 1) Preparing a metal layer on the surface of a high-reflectivity ceramic substrate to obtain a conductive circuit;

[0020] 2) fixing the light emitting element on the high reflectivity ceramic substrate and forming a conductive path with the conductive circuit;

[0021] 3) Using packaging glue to package the light-emitting element, and curing it to obtain an optical device.

[0022] In some embodiments of the present invention, the method for preparing the metal layer is selected from any one of printing, vacuum sputtering deposition, plasma spraying, and chemical plating processes.

[0023] In some embodiments of the present invention, the fixing method is selected from dip soldering, reflow soldering, wave soldering, eutectic soldering or gluing.

[0024] In some embodiments of the present invention, the curing temperature is 120-180° C., and the curing time is 0.5-4 hours.

[0025] As described above, the high reflectivity ceramic substrate and optical device of the present invention have the following beneficial effects:

[0026] 1. The high-reflectivity ceramic substrate provided by the present invention has a high reflectivity on the device surface by adding organic matter to the ceramic raw material to form internal pores and controlling the sintering temperature, which increases the conventional reflectivity of 85% to 95% or above, thereby improving the utilization rate of light and solving the heat dissipation problem.

[0027] 2. The optical device provided by the present invention is made of a high-reflectivity ceramic matrix, is integrally formed, and is simple to manufacture. It can be directly used as a heat dissipation substrate. It not only has extremely high temperature resistance and can be used normally in an environment of 1200°C, but also has good insulation properties of up to 15KV / mm, which solves or optimizes the application drawbacks of diffuse reflection coatings and diffuse reflection films on the market, such as temperature difference resistance, cumbersome operation, and impact on heat dissipation of light source devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the cross-sectional structure of an optical device according to an embodiment of the present invention.

[0029] Reference numerals:

[0030] 1-high reflectivity ceramic substrate; 2-light-emitting element; 3-conductive circuit; 4-lead; 5-packaging glue. DETAILED DESCRIPTION

[0031] The following is a detailed description of a high reflectivity ceramic substrate and an optical device of the present invention.

[0032] The inventor of the present invention started from the design concept of one-piece molding, and through internal pore creation and controlled sintering temperature, made the surface of the ceramic device have a higher reflectivity, from the conventional 85% reflectivity to 95% and above, thereby improving the utilization rate of light and solving the heat dissipation problem. On this basis, the present invention was completed.

[0033] The first aspect of the present invention provides a high-reflectivity ceramic substrate, which is prepared from ceramic raw materials including the following parts by weight: 75 to 95 parts of aluminum oxide, 5 to 25 parts of sintering aids, 1 to 10 parts of organic matter and 0.8 to 1.2 parts of dispersant; the sintering aid is selected from a mixture of any one or more of silicon micropowder, zinc oxide, titanium dioxide, zirconium oxide, magnesium oxide, yttrium oxide, sodium bicarbonate, sodium carbonate, magnesium carbonate, calcium carbonate, barium carbonate and calcined talc; the organic matter is selected from a mixture of any one or more of starch, polymethyl methacrylate, polyvinyl alcohol, polypropylene and polyethylene glycol.

[0034] In the present invention, alumina is an important component of ceramics, and the sintering aid plays a role in reducing the sintering temperature and promoting sintering densification; the organic matter acts as a porogen, which decomposes during the sintering process to form pores, and a ceramic material with excellent performance is obtained by controlling the porosity of the ceramic material; the dispersant can improve the dispersion state of the ceramic powder and the wettability between the powder and the liquid, thereby improving the processing performance and performance stability of the ceramic material.

[0035] For ease of description, the mixture of alumina and sintering aid is referred to as ceramic powder below, and the total mass of the ceramic powder is the total mass of alumina and sintering aid. In some preferred embodiments of the present invention, the relationship between the total mass of alumina, sintering aid, organic matter and dispersant and the total mass of ceramic powder is as follows:

[0036] The mass of the aluminum oxide accounts for 75% to 95% of the total mass of the ceramic powder, and can be 75% to 85%, 85% to 90%, or 90% to 95%.

[0037] The mass of the sintering aid accounts for 5% to 25% of the total mass of the ceramic powder, and can be 5% to 10%, 10% to 15%, 15% to 20%, or 20% to 25%.

[0038] The mass of the organic matter is 1% to 10% of the total mass of the ceramic powder, and can be 1% to 3%, 3% to 5%, 5% to 8%, or 8% to 10%.

[0039] The mass of the dispersant is 0.8% to 1.2% of the total mass of the ceramic powder, can be 0.8% to 1%, can also be 1% to 1.2%, and is preferably 1%.

[0040] In some embodiments of the present invention, the sintering aid includes silicon micropowder, calcium carbonate, calcined talc and titanium dioxide.

[0041] In some embodiments of the present invention, the dispersant is polyacrylamide.

[0042] In some preferred embodiments of the present invention, the ceramic raw materials include 92 parts of aluminum oxide, 4.9 parts of silicon powder, 3 parts of calcium carbonate, 0.1 parts of titanium dioxide, 10 parts of organic matter, and 1 part of dispersant.

[0043] The second aspect of the present invention provides a method for preparing the above-mentioned high reflectivity ceramic substrate, comprising the following steps:

[0044] (1) preparing an organic substance solution;

[0045] (2) adding water, dispersant, alumina and sintering aid into a ball mill and performing a ball milling operation;

[0046] (3) adding the organic substance solution into the ball mill and performing secondary ball milling to obtain a slurry;

[0047] (4) preparing the slurry into a ceramic body;

[0048] (5) The ceramic body is placed in a sintering furnace for sintering to obtain a high reflectivity ceramic matrix.

[0049] In some embodiments of the present invention, in step (1), the solvent of the organic substance solution is water. Specifically, warm water, such as warm water at 30-40° C., can be selected as the solvent according to the type and solubility of the organic substance.

[0050] In some embodiments of the present invention, in step (1), the mass fraction of the organic matter in the organic matter solution is 8-12%, which may be 8-9%, 9-10%, 10-11%, or 11-12%.

[0051] In some embodiments of the present invention, in step (2), the mass of the added water is 35-45% of the total mass of the ceramic raw material, and can be 35-40% or 40-45%.

[0052] In some embodiments of the present invention, in step (2), the rotation speed of the first ball mill is 20-60 Hz, can be 20-30 Hz, 30-40 Hz, 40-50 Hz, and can also be 50-60 Hz, and the ball milling time is 20-40 h, can be 20-25 h, 25-30 h, 30-35 h, and can also be 35-40 h. In some preferred embodiments of the present invention, the rotation speed of the first ball mill is 40 Hz, and the ball milling time is 30 h.

[0053] In some embodiments of the present invention, in step (3), the rotation speed of the secondary ball milling is 10-30 Hz, can be 10-15 Hz, 15-20 Hz, 20-25 Hz, and can also be 25-30 Hz, and the ball milling time is 1-3 h, can be 1-1.5 h, 1.5-2 h, 2-2.5 h, and can also be 2.5-3 h. In some preferred embodiments of the present invention, the rotation speed of the secondary ball milling is 20 Hz, and the ball milling time is 2 h.

[0054] In some embodiments of the present invention, in step (4), the method of preparing the slurry into a ceramic body is selected from grouting, dry pressing, gelling, and injection. In some preferred embodiments of the present invention, the method of preparing the slurry into a ceramic body is selected from dry pressing, and the dry pressing comprises the following steps: the slurry after ball milling is pumped into a granulation tower for spray granulation; after granulation, the ceramic body is dry pressed out using a mold.

[0055] In some embodiments of the present invention, in step (5), the sintering temperature is 1400-1600°C, which can be 1400-1410°C, 1410-1420°C, 1420-1430°C, 1430-1440°C, 1440-1450°C, 1450-1460°C, 1460-1470°C, 1470-1480°C, 1480-1490°C, 1490-1500°C, 1510-1520°C, 1520 ~1530℃, 1530~1540℃, 1540~1550℃, 1550~1560℃, 1560~1570℃, 1570~1580℃, 1580~1590℃, and can also be 1590~1600℃, and the sintering time is 1~12h, and can be 1~2h, 2~3h, 3~4h, 4~5h, 5~6h, 6~7h, 7~8h, 8~9h, 9~10h, 10~11h, and can also be 11~12h. In some preferred embodiments of the present invention, the sintering temperature is 1590℃ and the sintering time is 10h.

[0056] A third aspect of the present invention provides an optical device comprising the above-mentioned high-reflectivity ceramic substrate.

[0057] In some embodiments of the present invention, it further includes a metal layer disposed on the surface of the high reflectivity ceramic substrate, and a light-emitting element fixed on the high reflectivity ceramic substrate and forming a conductive path with the metal layer.

[0058] A fourth aspect of the present invention provides a method for preparing the above optical device, comprising the following steps:

[0059] 1) Preparing a metal layer on the surface of a high-reflectivity ceramic substrate to obtain a conductive circuit;

[0060] 2) Fixing the light-emitting element on a high-reflectivity ceramic substrate and forming a conductive path with the circuit;

[0061] 3) Using packaging glue to package the light-emitting element, and curing it to obtain an optical device.

[0062] In some embodiments of the present invention, the method for preparing the metal layer is selected from any one of printing, vacuum sputtering deposition, plasma spraying, and chemical plating processes.

[0063] In some embodiments of the present invention, the fixing method is selected from dip soldering, reflow soldering, wave soldering, eutectic soldering or gluing.

[0064] In some embodiments of the present invention, the curing temperature is 120-180°C, which can be 120-130°C, 130-140°C, 140-150°C, 150-160°C, 160-170°C, and can also be 170-180°C; the curing time is 0.5-4h, which can be 0.5-1h, 1-1.5h, 1.5-2h, 2-2.5h, 2.5-3h, 3-3.5h, and can also be 3.5-4h. In some preferred embodiments of the present invention, the curing temperature is 150°C and the curing time is 4h.

[0065] The specific embodiments of the present invention are further described in detail below in conjunction with preferred embodiments. When the embodiments provide numerical ranges, it should be understood that, unless otherwise specified in the present invention, the two endpoints of each numerical range and any numerical value between the two endpoints can be selected. Unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as those generally understood by those skilled in the art. In addition to the specific methods, equipment, and materials used in the embodiments, as those skilled in the art grasp the prior art and record the present invention, any methods, equipment, and materials of the prior art similar or equivalent to the methods, equipment, and materials described in the embodiments of the present invention can also be used to realize the present invention.

[0066] Unless otherwise specified, the experimental methods, detection methods, and preparation methods disclosed in the present invention all adopt conventional techniques in the relevant technical fields. Unless otherwise specified, the materials and equipment used in the present invention are all commercially available.

[0067] Example 1

[0068] 1. Preparation of high reflectivity ceramic substrate

[0069] (1) taking various raw materials according to weight proportions; preparing 10 parts of polyvinyl alcohol (PVA) into a PVA aqueous solution with a mass fraction of 10%;

[0070] (2) adding 40% of the total weight of the ceramic powder to water and 1 part of the dispersant polyacrylamide powder to a ball mill, and then adding 92 parts of alumina, 4.4 parts of silica powder, 3.5 parts of calcium carbonate, and 0.1 part of titanium dioxide, and starting the ball mill at a speed of 40 Hz for 30 hours;

[0071] (3) Add PVA aqueous solution and continue ball milling at 20 Hz for 2 h;

[0072] (4) pumping the ball-milled slurry into a granulation tower for spray granulation;

[0073] (5) After the granulation is completed, a ceramic body is dry-pressed out using a mold, and the ceramic body is placed in a sintering furnace at 1400° C. and sintered for 10 hours to form a porous structured high-reflectivity ceramic substrate.

[0074] 2. Preparation of optical devices

[0075] S1, printing a metal layer on the surface of a high-reflectivity ceramic substrate 1 to obtain a conductive circuit 3;

[0076] S2, soldering the light emitting element 2 to the high reflectivity ceramic substrate 1, and connecting the light emitting element to the conductive circuit 3 with the lead wire 4 to form a conductive path;

[0077] S3. Use packaging glue 5 to package the light emitting element 2, and cure it at 150° C. for 4 hours to obtain an integrated ceramic high-reflection optical device.

[0078] Example 2

[0079] 1. Preparation of high reflectivity ceramic substrate

[0080] (1) taking various raw materials according to weight proportions; preparing 10 parts of polyvinyl alcohol (PVA) into a PVA aqueous solution with a mass fraction of 10%;

[0081] (2) adding 40% of the total weight of the ceramic powder to water and 1 part of the dispersant polyacrylamide powder to a ball mill, and then adding 92 parts of aluminum oxide, 4.9 parts of silicon micropowder, 3 parts of calcium carbonate, and 0.1 parts of titanium dioxide, and starting the ball mill at a speed of 40 Hz for 30 hours;

[0082] (3) Add PVA aqueous solution and continue ball milling at 20 Hz for 2 h;

[0083] (4) pumping the ball-milled slurry into a granulation tower for spray granulation;

[0084] (5) After the granulation is completed, a ceramic body is dry-pressed out using a mold, and the ceramic body is placed in a sintering furnace at 1590° C. and sintered for 10 hours to form a porous structured high-reflectivity ceramic substrate.

[0085] 2. Preparation of optical devices

[0086] The preparation method is the same as Example 1.

[0087] Example 3

[0088] 1. Preparation of high reflectivity ceramic substrate

[0089] (1) taking various raw materials according to weight proportions; preparing 10 parts of polyvinyl alcohol (PVA) into a PVA aqueous solution with a mass fraction of 10%;

[0090] (2) adding 40% of the total weight of the ceramic powder to water and 1 part of the dispersant polyacrylamide powder to a ball mill, and then adding 92 parts of alumina, 3 parts of silica powder, 3.4 parts of calcium carbonate, 1.5 parts of calcined talc, and 0.1 parts of titanium dioxide, and starting the ball mill at a speed of 40 Hz for 30 hours;

[0091] (3) Add PVA aqueous solution and continue ball milling at 20 Hz for 2 h;

[0092] (4) pumping the ball-milled slurry into a granulation tower for spray granulation;

[0093] (5) After the granulation is completed, a ceramic body is dry-pressed out using a mold, and the ceramic body is placed in a sintering furnace at 1590° C. and sintered for 2 h to form a porous structured high-reflectivity ceramic substrate.

[0094] 2. Preparation of optical devices

[0095] The preparation method is the same as Example 1.

[0096] Example 4

[0097] 1. Preparation of high reflectivity ceramic substrate

[0098] (1) taking various raw materials according to weight proportions; preparing 10 parts of polyvinyl alcohol (PVA) into a PVA aqueous solution with a mass fraction of 10%;

[0099] (2) 40% of the total weight of the ceramic powder was added to the water and 1 part of the dispersant polyacrylamide powder into the ball mill, and then 92 parts of alumina, 3 parts of silica powder, 1.2 parts of calcium carbonate, 3.7 parts of calcined talc, and 0.1 parts of titanium dioxide were added, and the ball mill was started at a speed of 40 Hz for 30 hours;

[0100] (3) Add PVA aqueous solution and continue ball milling at 20 Hz for 2 h;

[0101] (4) pumping the ball-milled slurry into a granulation tower for spray granulation;

[0102] (5) After the granulation is completed, a ceramic body is dry-pressed out using a mold, and the ceramic body is placed in a sintering furnace at 1400° C. and sintered for 10 hours to form a porous structured high-reflectivity ceramic substrate.

[0103] 2. Preparation of optical devices

[0104] The preparation method is the same as Example 1.

[0105] Example 5

[0106] 1. Preparation of high reflectivity ceramic substrate

[0107] (1) taking various raw materials according to weight proportions; preparing 5 parts of polyethylene glycol and 5 parts of polymethyl methacrylate into an aqueous solution with a solute mass fraction of 12%, i.e., an organic substance solution;

[0108] (2) Add 40% of the total weight of the ceramic powder into a ball mill along with 1 part of polyacrylamide powder as a dispersant, 92 parts of alumina, 0.5 parts of silica powder, 0.5 parts of calcium carbonate, 6.9 parts of calcined talc, and 0.1 parts of titanium dioxide, and start the ball mill at a speed of 40 Hz for 30 hours;

[0109] (3) Add the organic solution and continue ball milling at 20 Hz for 2 h;

[0110] (4) pumping the ball-milled slurry into a granulation tower for spray granulation;

[0111] (5) After the granulation is completed, a ceramic body is dry-pressed out using a mold, and the ceramic body is placed in a sintering furnace at 1590° C. and sintered for 10 hours to form a porous structured high-reflectivity ceramic substrate.

[0112] 2. Preparation of optical devices

[0113] The preparation method is the same as Example 1.

[0114] Example 6

[0115] 1. Preparation of high reflectivity ceramic substrate

[0116] (1) taking various raw materials according to weight proportions; preparing 10 parts of polyvinyl alcohol (PVA) into a PVA aqueous solution with a mass fraction of 10%;

[0117] (2) Add 40% of the total weight of the ceramic powder into a ball mill, along with 1 part of the dispersant polyacrylamide powder, 75 parts of alumina, 10 parts of silica powder, 8 parts of calcium carbonate, 6.9 parts of calcined talc, and 0.1 parts of titanium dioxide. Start the ball mill and mill at 40 Hz for 30 hours.

[0118] (3) Add PVA aqueous solution and continue ball milling at 20 Hz for 2 h;

[0119] (4) pumping the ball-milled slurry into a granulation tower for spray granulation;

[0120] (5) After the granulation is completed, a ceramic body is dry-pressed out using a mold, and the ceramic body is placed in a sintering furnace at 1590° C. and sintered for 10 hours to form a porous structured high-reflectivity ceramic substrate.

[0121] 2. Preparation of optical devices

[0122] The preparation method is the same as Example 1.

[0123] Example 7

[0124] 1. Preparation of high reflectivity ceramic substrate

[0125] (1) taking various raw materials according to weight proportions; preparing 10 parts of polyvinyl alcohol (PVA) into a PVA aqueous solution with a mass fraction of 10%;

[0126] (2) adding 40% of the total weight of the ceramic powder to water and 1 part of polyacrylamide powder into a ball mill, adding 80 parts of alumina, 4.9 parts of silica powder, 3 parts of calcium carbonate, 12 parts of calcined talc, and 0.1 parts of titanium dioxide, and starting the ball mill at a speed of 40 Hz for 30 hours;

[0127] (3) Add PVA aqueous solution and continue ball milling at 20 Hz for 2 h;

[0128] (4) pumping the ball-milled slurry into a granulation tower for spray granulation;

[0129] (5) After the granulation is completed, a ceramic body is dry-pressed out using a mold, and the ceramic body is placed in a sintering furnace at 1590° C. and sintered for 10 hours to form a porous structured high-reflectivity ceramic substrate.

[0130] 2. Preparation of optical devices

[0131] The preparation method is the same as Example 1.

[0132] Example 8

[0133] 1. Preparation of high reflectivity ceramic substrate

[0134] (1) taking various raw materials according to weight proportions; preparing 10 parts of polyvinyl alcohol (PVA) into a PVA aqueous solution with a mass fraction of 10%;

[0135] (2) Add 40% of the total weight of the ceramic powder to water and 1 part of the dispersant polyacrylamide powder into a ball mill, add 95 parts of aluminum oxide, 3.9 parts of silicon powder, 1 part of calcium carbonate, and 0.1 part of titanium dioxide, and start the ball mill at a speed of 40 Hz for 30 hours;

[0136] (3) Add PVA aqueous solution and continue ball milling at 20 Hz for 2 h;

[0137] (4) pumping the ball-milled slurry into a granulation tower for spray granulation;

[0138] (5) After the granulation is completed, a ceramic body is dry-pressed out using a mold, and the ceramic body is placed in a sintering furnace at 1590° C. and sintered for 10 hours to form a porous structured high-reflectivity ceramic substrate.

[0139] 2. Preparation of optical devices

[0140] The preparation method is the same as Example 1.

[0141] Example 9

[0142] 1. Preparation of high reflectivity ceramic substrate

[0143] (1) taking various raw materials according to weight proportions; preparing 10 parts of polyvinyl alcohol (PVA) into a PVA aqueous solution with a mass fraction of 10%;

[0144] (2) adding 40% of the total weight of the ceramic powder and 1 part of the dispersant polyacrylamide powder into a ball mill, adding 92 parts of aluminum oxide, 4.4 parts of silicon powder, 3.5 parts of calcium carbonate, and 0.1 parts of titanium dioxide, and starting the ball mill at a speed of 40 Hz for 30 hours;

[0145] (3) Add PVA aqueous solution and continue ball milling at 20 Hz for 2 h;

[0146] (4) pumping the ball-milled slurry into a granulation tower for spray granulation;

[0147] (5) After the granulation is completed, a ceramic body is dry-pressed out using a mold, and the ceramic body is placed in a sintering furnace at 1600° C. and sintered for 10 hours to form a porous structured high-reflectivity ceramic substrate.

[0148] 2. Preparation of optical devices

[0149] The preparation method is the same as Example 1.

[0150] Comparative Example 1

[0151] 1. Preparation of ceramic substrate

[0152] (1) taking various raw materials according to weight proportions; preparing 10 parts of polyvinyl alcohol (PVA) into a PVA aqueous solution with a mass fraction of 10%;

[0153] (2) adding 40% of the total weight of the ceramic powder and 1 part of the dispersant polyacrylamide powder into a ball mill, adding 92 parts of alumina, 4.5 parts of silica powder, and 3.5 parts of calcium carbonate, and starting the ball mill at a speed of 40 Hz for 30 hours;

[0154] (3) Add PVA aqueous solution and continue ball milling at 20 Hz for 2 h;

[0155] (4) pumping the ball-milled slurry into a granulation tower for spray granulation;

[0156] (5) After granulation is completed, a ceramic body is dry-pressed out using a mold, and the ceramic body is placed in a sintering furnace at 1590° C. and sintered for 10 hours to form a ceramic substrate.

[0157] 2. Preparation of optical devices

[0158] The preparation method is the same as Example 1.

[0159] Comparative Example 2

[0160] 1. Preparation of ceramic substrate

[0161] (1) taking various raw materials according to weight proportions; preparing 10 parts of polyvinyl alcohol (PVA) into a PVA aqueous solution with a mass fraction of 10%;

[0162] (2) Add 40% of the total weight of the ceramic powder into a ball mill along with 1 part of polyacrylamide powder as a dispersant, 70 parts of alumina, 7.9 parts of silica powder, 9.5 parts of calcium carbonate, and 0.1 parts of titanium dioxide, and start the ball mill at a speed of 40 Hz for 30 hours;

[0163] (3) Add PVA aqueous solution and continue ball milling at 20 Hz for 2 h;

[0164] (4) pumping the ball-milled slurry into a granulation tower for spray granulation;

[0165] (5) After granulation is completed, a ceramic body is dry-pressed out using a mold, and the ceramic body is placed in a sintering furnace at 1590° C. and sintered for 10 hours to form a ceramic substrate.

[0166] 2. Preparation of optical devices

[0167] The preparation method is the same as Example 1.

[0168] Comparative Example 3

[0169] 1. Preparation of ceramic substrate

[0170] (1) taking various raw materials according to weight proportions; preparing 10 parts of polyvinyl alcohol (PVA) into a PVA aqueous solution with a mass fraction of 10%;

[0171] (2) Add 40% of the total weight of the ceramic powder into a ball mill along with 1 part of polyacrylamide powder as a dispersant, 98 parts of alumina, 0.9 parts of silica powder, 1 part of calcium carbonate, and 0.1 parts of titanium dioxide, and start the ball mill at a speed of 40 Hz for 30 hours;

[0172] (3) Add PVA aqueous solution and continue ball milling at 20 Hz for 2 h;

[0173] (4) pumping the ball-milled slurry into a granulation tower for spray granulation;

[0174] (5) After granulation is completed, a ceramic body is dry-pressed out using a mold, and the ceramic body is placed in a sintering furnace at 1590° C. and sintered for 10 hours to form a ceramic substrate.

[0175] 2. Preparation of optical devices

[0176] The preparation method is the same as Example 1.

[0177] Comparative Example 4

[0178] 1. Preparation of ceramic substrate

[0179] (1) taking various raw materials according to weight proportions; preparing 10 parts of polyvinyl alcohol (PVA) into a PVA aqueous solution with a mass fraction of 10%;

[0180] (2) adding 40% of the total weight of the ceramic powder to water and 1 part of the dispersant polyacrylamide powder into a ball mill, adding 92 parts of aluminum oxide, 4.9 parts of silicon micropowder, 3 parts of calcium carbonate, and 0.1 parts of titanium dioxide, and starting the ball mill at a speed of 40 Hz for 30 hours;

[0181] (3) Add PVA aqueous solution and continue ball milling at 20 Hz for 2 h;

[0182] (4) pumping the ball-milled slurry into a granulation tower for spray granulation;

[0183] (5) After granulation is completed, a ceramic body is dry-pressed out using a mold, and the ceramic body is placed in a sintering furnace at 1350° C. and sintered for 10 hours to form a ceramic substrate.

[0184] (6) The ceramic substrate is too weak to be used as a heat sink.

[0185] Comparative Example 5

[0186] 1. Preparation of ceramic substrate

[0187] (1) taking various raw materials according to weight proportions; preparing 10 parts of polyvinyl alcohol (PVA) into a PVA aqueous solution with a mass fraction of 10%;

[0188] (2) adding 40% of the total weight of the ceramic powder to water and 1 part of the dispersant polyacrylamide powder into a ball mill, adding 92 parts of aluminum oxide, 4.5 parts of silicon micropowder, 3.5 parts of calcium carbonate, and 0.1 part of titanium dioxide, and starting the ball mill at a speed of 40 Hz for 30 hours;

[0189] (3) adding 1.2% of the total weight of the powder into a PVA aqueous solution (the weight of PVA in the PVA aqueous solution is 10 parts) and continuing to ball mill at a speed of 20 Hz for 2 hours;

[0190] (4) pumping the ball-milled slurry into a granulation tower for spray granulation;

[0191] (5) After the granulation is completed, a ceramic body is dry-pressed out using a mold, and the ceramic body is placed in a sintering furnace at 1700° C. and sintered for 10 hours to form a porous structured high-reflectivity ceramic substrate.

[0192] 2. Preparation of optical devices

[0193] The preparation method is the same as Example 1.

[0194] The optical devices prepared in Examples 1 to 9 and Comparative Examples 1 to 5 were tested for product performance, and the test results are shown in Table 1 below.

[0195] Table 1

[0196]

[0197]

[0198] As can be seen from Table 1, the reflectivity of the optical devices prepared in Examples 1 to 9 of the present invention is above 89.5%, and Examples 1, 2, 4 and 9 reach above 96%. Compared with Example 1, no titanium dioxide is added in Comparative Example 1. When the sintering temperature is 1590°C, the ceramic surface reflectivity is only 73.62%, which is much lower than the ceramic surface reflectivity of 96.06% in Example 1, indicating that titanium dioxide plays a key role in improving the ceramic surface reflectivity. Compared with Example 2, the mass proportion of alumina in the ceramic powder is 70%, and the ceramic surface reflectivity is only 70.12%, which is much lower than the ceramic surface reflectivity of 96.64% in Example 2, indicating that the mass proportion of alumina is too low, which will affect the ceramic surface reflectivity; Compared with Example 2, when the mass proportion of alumina in the ceramic powder is 98%, the ceramic surface reflectivity is only 77.33%, indicating that the mass proportion of alumina is too high, which affects the ceramic surface reflectivity. Therefore, the mass proportion of alumina needs to be within an appropriate range to ensure the high reflectivity of the ceramic surface. Comparative Example 4 is compared with Example 2. In Example 2, the sintering temperature is 1590°C, and the ceramic surface reflectivity can reach 96.64%; while in Comparative Example 4, the sintering temperature is 1350°C, and the strength of the ceramic body is too poor to be used as a heat sink. Comparative Example 5 is compared with Example 2. When the sintering temperature is 1700°C, the ceramic surface reflectivity is only 73.54%, indicating that the sintering temperature has an important influence on the strength and surface reflectivity of the ceramic. Only within the appropriate sintering temperature range can a ceramic substrate with the required strength and high reflectivity be obtained.

[0199] In summary, the present invention optimizes the proportion of alumina and sintering aids in ceramic powder, adds organic matter to form internal pores and control the sintering temperature, and forms the device in one piece, so that the device surface has a higher reflectivity, from the conventional 85% reflectivity to 95% and above, thereby improving the utilization rate of light by optical devices and solving the heat dissipation problem. The present invention effectively overcomes various shortcomings in the prior art and has a high industrial utilization value.

[0200] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A high reflectivity ceramic substrate, characterized in that: The ceramic material is prepared from the following ceramic raw materials in parts by weight: 75-95 parts of aluminum oxide, 5-25 parts of sintering aids, 1-10 parts of organic matter and 0.8-1.2 parts of dispersant; the sintering aid is selected from a mixture of any one or more of silicon micropowder, zinc oxide, titanium dioxide, zirconium oxide, magnesium oxide, yttrium oxide, sodium bicarbonate, sodium carbonate, magnesium carbonate, calcium carbonate, barium carbonate and calcined talc; the organic matter is selected from a mixture of any one or more of starch, polymethyl methacrylate, polyvinyl alcohol, polypropylene and polyethylene glycol.

2. The high reflectivity ceramic substrate according to claim 1, characterized in that: Includes one or more of the following characteristics: (1) The mass of the alumina accounts for 75% to 95% of the total mass of the alumina and the sintering aid; (2) The mass of the organic substance is 1% to 10% of the total mass of the alumina and the sintering aid; (3) The mass of the dispersant is 0.8% to 1.2% of the total mass of alumina and sintering aid; (4) The sintering aid includes silicon micropowder, titanium dioxide, calcium carbonate and calcined talc; (5) The dispersant is polyacrylamide.

3. A method for preparing a high reflectivity ceramic substrate as claimed in claim 1 or 2, characterized in that: The steps include: (1) preparing an organic substance solution; (2) adding water, dispersant, alumina and sintering aid into a ball mill and performing a ball milling operation; (3) adding the organic substance solution into the ball mill and performing secondary ball milling to obtain a slurry; (4) preparing the slurry into a ceramic body; (5) The ceramic body is placed in a sintering furnace for sintering to obtain a high reflectivity ceramic matrix.

4. The preparation method according to claim 3, characterized in that: Includes one or more of the following characteristics: (a) In step (1), the solvent of the organic substance solution is water; (b) In step (1), the mass fraction of organic matter in the organic matter solution is 8 to 12%; (c) In step (2), the mass of the added water is 35-45% of the total mass of the ceramic raw material; (d) In step (2), the rotation speed of the first ball milling is 20 to 60 Hz, and the ball milling time is 20 to 40 hours; (e) In step (3), the rotation speed of the secondary ball milling is 10 to 30 Hz, and the ball milling time is 1 to 3 hours; (f) in step (4), the method of preparing the slurry into a ceramic body is selected from slip casting, dry pressing, gelling, and injection; (g) In step (5), the sintering temperature is 1400-1600° C. and the sintering time is 1-12 hours.

5. An optical device, characterized in that: It comprises the high reflectivity ceramic substrate as claimed in claim 1 or 2 or the high reflectivity ceramic substrate prepared by the preparation method as claimed in claim 3 or 4.

6. The optical device according to claim 5, characterized in that It also includes a metal conductive layer disposed on the surface of the high reflectivity ceramic substrate, and a light emitting element fixed on the high reflectivity ceramic substrate and forming a conductive path with the metal layer.

7. A method for preparing an optical device according to claim 5 or 6, characterized in that: The steps include: 1) Preparing a metal layer on the surface of a high-reflectivity ceramic substrate to obtain a conductive circuit; 2) fixing the light emitting element on the high reflectivity ceramic substrate and forming a conductive path with the conductive circuit; 3) Using packaging glue to package the light-emitting element, and curing it to obtain an optical device.

8. The method for preparing an optical device according to claim 7, characterized in that: The method for preparing the metal layer is selected from any one of printing, vacuum sputtering deposition, plasma spraying and chemical plating processes.

9. The method for preparing an optical device according to claim 7, characterized in that: The fixing method is selected from dip soldering, reflow soldering, wave soldering, eutectic soldering or gluing.

10. The method for preparing an optical device according to claim 7, characterized in that: The curing temperature is 120-180° C., and the curing time is 0.5-4 hours.

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