A method of welding an aluminum nitride ceramic heating disc

Abstract

The application provides a welding method of an aluminum nitride ceramic heating disc, which comprises the following steps: firstly, performing fine grinding and cleaning on the welding surfaces of an aluminum nitride sleeve and an aluminum nitride disc body; then, printing and coating Y2O3-CaCO3-SiO2-MgO on the welding surfaces of the aluminum nitride sleeve and the aluminum nitride disc body; and finally, performing sintering treatment, so that the aluminum nitride ceramic heating disc with good sealing performance, high welding strength and high thermal conductivity can be obtained, and the aluminum nitride ceramic heating disc is suitable for large-scale popularization and application.

Description

Technical Field

[0001] This invention relates to the field of ceramic welding technology, and in particular to a welding method for an aluminum nitride ceramic heating plate. Background Technology

[0002] Aluminum nitride ceramics possess excellent heat dissipation, stability, and insulation properties, making them widely used in semiconductors, smart power modules, automotive electronics, and solar energy. In semiconductor manufacturing, aluminum nitride ceramic heaters are used to heat wafers, thereby improving CVD (Continuous Chemical Deposition) results and producing more uniform thin films. Aluminum nitride ceramics have high hardness and brittleness, so complex components are often fabricated individually and then joined by welding. Aluminum nitride ceramic heaters are primarily used in vacuum environments, requiring high sealing at the connection between the disk and the sleeve. During use, the sleeve provides stable support for the disk, so the connection needs good bonding strength to ensure stability and prevent breakage. Furthermore, the difference in thermal conductivity between the welded joint and the disk and sleeve materials must be considered to avoid affecting the temperature uniformity of the disk surface.

[0003] Currently, the welding of ceramic materials mainly adopts the following method: adding a metallization layer or solder layer between the components to be connected, melting the metallization layer or solder layer at high temperature, and then wetting the welding surface of the components with the molten solder layer. During the heat preservation process, material diffusion occurs between the components to achieve the connection. Because aluminum nitride ceramic heaters have specific requirements for the thermal conductivity and volume resistivity of the material, and the thermal conductivity and volume resistivity of the material are closely related to the grain size, if a high welding temperature is used between the components, it will cause changes in the grain size of the aluminum nitride ceramic material, and internal defects will easily occur inside the disc and sleeve, affecting thermal conductivity and volume resistivity. Therefore, it is necessary to develop low-melting-point solder to achieve the connection of ceramic components and ensure the bonding strength, sealing, and insulation of the connection position.

[0004] CN114012255A discloses a ceramic welding method to solve the technical problem of low connection force between ceramic workpieces. The method involves electroplating the joint end faces of two ceramic workpieces to be welded, filling the gap between the cross faces with solder, which includes ceramic powder; heating the solder to make the ceramic powder form a sintered body of the joint end faces to achieve a tight connection of the workpieces.

[0005] CN113173797A discloses an Al2O3-based ceramic welding sealing component and its preparation method. Tungsten powder, titanium powder, molybdenum oxide, boron oxide, yttrium oxide and organic binder are uniformly mixed to obtain a metallizing paste, which is then uniformly coated on both ends of a ceramic substrate by screen printing and sintered in a vacuum furnace to obtain a sealing component.

[0006] CN113185314A discloses a boron nitride-based ceramic welding sealing component and its preparation method. The boron nitride-based ceramic welding sealing component includes a ceramic matrix and a metallization layer. The ceramic matrix is ​​made from inorganic fiber-boron nitride three-dimensional network matrix, yttrium oxide, silicon oxide, titanium oxide, additives, binders, and dispersants, etc., through steps such as inorganic fiber-boron nitride three-dimensional network matrix preparation, mixing, granulation, primary sintering, and secondary sintering. The metallization layer raw materials include titanium powder, tungsten powder, molybdenum oxide, boron oxide, aluminum oxide, and organic binders.

[0007] In the above-mentioned ceramic welding method, metal powder and / or oxides are added to the welding layer material. During the welding process, the metal elements in the metal powder diffuse to both ends. When applied to aluminum nitride ceramic heaters, this can easily cause changes in the thermal conductivity and volume resistivity of the ceramic material. The welding layer formed by the oxides in the welding layer material requires a high welding temperature. When used in aluminum nitride heating plates, this can easily cause changes in the grain size of the aluminum nitride ceramic material, and internal defects can easily occur inside the plate and sleeve, affecting thermal conductivity and volume resistivity. Summary of the Invention

[0008] In view of the problems existing in the prior art, the present invention provides a welding method for aluminum nitride ceramic heating plates. By using Y2O3-CaCO3-SiO2-MgO as the welding layer material, the aluminum nitride sleeve and aluminum nitride plate body can be sintered to obtain an aluminum nitride ceramic heating plate with good sealing performance, high welding strength and high thermal conductivity, which is suitable for large-scale promotion and application.

[0009] To achieve this objective, the present invention adopts the following technical solution:

[0010] This invention provides a welding method for an aluminum nitride ceramic heating plate, the welding method comprising the following steps:

[0011] (1) The welding surface of the aluminum nitride sleeve is subjected to a first fine grinding process and a first cleaning process to obtain the aluminum nitride sleeve to be welded; the welding surface of the aluminum nitride disc is subjected to a second fine grinding process and a second cleaning process to obtain the aluminum nitride disc to be welded.

[0012] (2) A welding layer material is printed and coated on the welding surface of the aluminum nitride sleeve to be welded and the welding surface of the aluminum nitride disk to be welded to obtain a combined component;

[0013] The welding layer material is Y2O3-CaCO3-SiO2-MgO;

[0014] (3) The combined components are sintered to obtain the aluminum nitride ceramic heating plate.

[0015] The welding method for the aluminum nitride ceramic heating plate described in this invention first involves fine grinding and cleaning of the welding surfaces of the aluminum nitride sleeve and the aluminum nitride plate. Fine grinding reduces surface roughness, improves the adhesion of the welding layer material, reduces unevenness in the welding area, minimizes stress concentration during welding, and ensures uniform load transfer after welding. Cleaning removes surface dirt and oil stains, prevents defects such as porosity and inclusions during welding, and prevents cracks in the weld due to inclusions, ensuring welding quality. Then, Y2O3-CaCO3-SiO2-MgO is used as the welding layer material. The addition of SiO2 lowers the melting point of the welding layer material, avoiding performance loss of the aluminum nitride ceramic material during high-temperature welding. This allows the welding layer material to easily form a liquid phase between the welding surfaces, wetting them and facilitating a tighter connection between the aluminum nitride sleeve and the aluminum nitride plate after sintering, resulting in higher welding strength. Furthermore, the welding layer material prevents uneven temperature distribution in the aluminum nitride ceramic heating plate, preventing cracks caused by repeated heating and cooling during subsequent use.

[0016] Preferably, in step (1), the first fine grinding process is carried out with 100 to 300 grit sandpaper, such as 100 grit, 110 grit, 150 grit, 180 grit, 200 grit, 250 grit or 300 grit, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0017] Preferably, the cleaning solution for the first cleaning includes deionized water and 99.7% anhydrous ethanol.

[0018] Preferably, the second fine grinding process uses 800-1000 grit sandpaper, such as 800 grit, 810 grit, 850 grit, 880 grit, 900 grit, 950 grit or 1000 grit, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0019] Preferably, the cleaning solution for the second cleaning includes deionized water, acetone, and 99.7%.

[0020] Preferably, by mass percentage, the raw materials for preparing the Y2O3-CaCO3-SiO2-MgO welding layer material in step (2) include:

[0021] 1 to 2 wt% Y2O3 powder, for example, can be 1 wt%, 1.1 wt%, 1.3 wt%, 1.5 wt%, 1.6 wt%, 1.8 wt%, or 2 wt%, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0022] 1 to 2 wt% CaCO3 powder, for example, can be 1 wt%, 1.1 wt%, 1.3 wt%, 1.5 wt%, 1.6 wt%, 1.8 wt%, or 2 wt%, but is not limited to the listed values; other unlisted values ​​within this range also apply.

[0023] 3 to 5 wt% SiO2 powder, for example, 3 wt%, 3.1 wt%, 3.3 wt%, 3.5 wt%, 4 wt%, 4.5 wt%, or 5 wt%, but not limited to the listed values; other unlisted values ​​within this range also apply.

[0024] The preferred embodiment of the present invention, the Y2O3-CaCO3-SiO2-MgO welding layer material, includes 3-5 wt% SiO2 powder. When <3 wt% SiO2 powder is added, the SiO2 powder has a lower influence on the melting point of the welding layer material, resulting in poor densification after sintering, poor sealing at the welding position, and a leakage rate >1.0 × 10⁻⁶. -7 mmbar / s; When more than 5 wt% SiO2 powder is added, the welding layer material will melt too much, the welding layer material will become more fluid and overflow from the welding position, resulting in low welding strength of aluminum nitride ceramic heating plate, welding strength ≤50MPa.

[0025] 1–3 wt% MgO powder, for example, can be 1 wt%, 1.5 wt%, 1.8 wt%, 2 wt%, 2.5 wt%, 2.8 wt%, or 3 wt%, but is not limited to the listed values; other unlisted values ​​within this range also apply; the remainder is AlN powder.

[0026] Preferably, the particle size of the Y2O3 powder is 50-500 nm, for example, it can be 50 nm, 80 nm, 100 nm, 150 nm, 200 nm, 300 nm, 400 nm or 500 nm, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0027] Preferably, the particle size of the CaCO3 powder is 50-500 nm, for example, it can be 50 nm, 80 nm, 100 nm, 150 nm, 200 nm, 300 nm, 400 nm or 500 nm, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0028] Preferably, the particle size of the SiO2 powder is 0.8 to 1.2 μm, for example, it can be 0.8 μm, 0.85 μm, 0.9 μm, 0.95 μm, 1 μm, 1.1 μm, 1.15 μm or 1.2 μm, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0029] Preferably, the particle size of the MgO powder is 50-500 nm, for example, it can be 50 nm, 80 nm, 100 nm, 150 nm, 200 nm, 300 nm, 400 nm or 500 nm, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0030] Preferably, the particle size of the AlN powder is 1 to 1.2 μm, for example, it can be 1 μm, 1.05 μm, 1.07 μm, 1.09 μm, 1.1 μm, 1.13 μm, 1.15 μm or 1.2 μm, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0031] Preferably, the preparation method of Y2O3-CaCO3-SiO2-MgO in step (2) includes:

[0032] Each raw material is ball-milled, then dried and sieved to obtain a mixture; the mixture is then mixed with polyvinyl butyral to obtain Y2O3-CaCO3-SiO2-MgO.

[0033] Preferably, anhydrous ethanol with a purity of 98% to 99.7% is added during the ball milling process. For example, it can be 98%, 98.3%, 98.5%, 99%, 99.2%, 99.5%, 99.6%, or 99.7%, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0034] In this invention, anhydrous ethanol with a purity of 98% to 99.7% is preferably added during the ball milling process. Compared with dry ball milling, this has the advantages of improving mixing uniformity and preventing powder agglomeration. The presence of the solvent can increase the lubricity of the powder and reduce the friction between particles, so that powder particles of different sizes and densities can be fully mixed and dispersed. At the same time, it can avoid the agglomeration of dry powder due to electrostatic effects during the mixing process, and can obtain a finer and more uniform particle mixture.

[0035] Preferably, the ball milling speed is 80 to 160 rpm, for example, it can be 80 rpm, 90 rpm, 100 rpm, 110 rpm, 120 rpm, 130 rpm, 150 rpm or 160 rpm, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0036] Preferably, the ball milling time is 16 to 24 hours, for example, 16 hours, 18 hours, 20 hours, 22 hours, 23 hours, 23.5 hours or 24 hours, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0037] Preferably, the drying temperature is 100-120°C, for example, it can be 100°C, 102°C, 104°C, 105°C, 108°C, 110°C, 115°C or 120°C, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0038] Preferably, the drying time is 18 to 24 hours, for example, it can be 18 hours, 20 hours, 22 hours, 23 hours, 23.5 hours or 24 hours, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0039] Preferably, the sieving process is carried out using a 150-250 mesh screen, such as 150 mesh, 160 mesh, 170 mesh, 200 mesh, 210 mesh, 230 mesh, 240 mesh or 250 mesh, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0040] Preferably, the amount of polyvinyl butyral added is 2 to 5 wt% of the mass of the mixture, for example, it can be 2 wt%, 2.2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%, 4.5 wt%, or 5 wt%, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0041] The preferred amount of polyvinyl butyral added in this invention is 2-5 wt% of the mixture, which has the advantages of good slurry bonding strength, uniform slurry, and easy coating. When the amount of polyvinyl butyral added is too small, the mixed slurry is difficult to coat, has poor adhesion, and the sample falls off, making it difficult to assemble and fix the sample in place. When the amount of polyvinyl butyral added is too large, the mixed slurry becomes hard and brittle, difficult to coat, and the internal pores of the slurry increase, which cannot be effectively expelled, affecting the welding quality.

[0042] Preferably, the total thickness of the welding layer material printed and coated in step (2) is 50 to 300 μm, for example, it can be 50 rpm, 80 rpm, 100 rpm, 120 rpm, 150 rpm, 200 rpm, 250 rpm or 300 rpm, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0043] The preferred total thickness of the printed coating welding layer material is 50–300 μm, where the thickness refers to the thickness between the sleeve welding surface and the disc welding surface. This specific thickness range offers advantages in ensuring welding strength, welding sealing, and avoiding welding defects. When the total thickness of the printed coating welding layer material is too thin, insufficient solder to fill the gaps results in lower welding strength, poor sealing of the welded area, and difficulty in wetting the two welding surfaces, leading to poor welding quality. Conversely, when the total thickness of the printed coating welding layer material is too thick, the welding area strength is lower than that of the welding material, resulting in poor weld strength. Furthermore, a thick solder layer can cause significant thermal stress differences during post-weld cooling, easily leading to weld cracking, and the welding layer is prone to defects such as porosity, becoming a source of cracking.

[0044] Preferably, the sintering process in step (3) is carried out in a nitrogen atmosphere.

[0045] Preferably, the sintering temperature in step (3) is 1500 to 1600°C, for example, it can be 1500°C, 1510°C, 1530°C, 1550°C, 1570°C, 1590°C or 1600°C, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0046] The preferred sintering temperature of this invention is 1500–1600℃. This prevents the high-temperature welding process from affecting the material properties of the aluminum nitride ceramic heating plate, while simultaneously forming a tighter connection, ensuring that the sealing performance, welding strength, and thermal conductivity of the aluminum nitride ceramic heating plate meet product requirements. At lower sintering temperatures, the welding layer material may not completely melt, resulting in poor wettability between the two welding surfaces. The solder cannot effectively fill the weld gap, and the lower temperature makes it difficult to remove gas from the weld, leading to residual gas forming pores and poor bonding between the two welding surfaces. Ultimately, this results in poor joint sealing and low weld strength. At higher sintering temperatures, grain growth occurs in the two base materials, reducing the thermal conductivity of the matrix. Overheating can also occur in the weld area, increasing hardness and brittleness, and lowering strength. Higher temperatures may also cause excessive evaporation or loss of the solder, preventing the formation of a high-quality weld area.

[0047] Preferably, the sintering time is 1.5 to 4.5 hours, for example, it can be 1.5 hours, 1.8 hours, 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours or 4.5 hours, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0048] As a preferred embodiment of the present invention, the welding method includes the following steps:

[0049] (1) The welding surface of the aluminum nitride sleeve is subjected to a first fine grinding process and a first cleaning process to obtain the aluminum nitride sleeve to be welded; the welding surface of the aluminum nitride disc is subjected to a second fine grinding process and a second cleaning process to obtain the aluminum nitride disc to be welded.

[0050] The first fine grinding process uses 100-300 grit sandpaper; the first cleaning solution includes deionized water or 99.7% anhydrous ethanol; the second fine grinding process uses 800-1000 grit sandpaper; the second cleaning solution includes any one of deionized water, acetone, or 99.7% isopropanol.

[0051] (2) A Y2O3-CaCO3-SiO2-MgO coating with a total thickness of 50-300 μm is printed and coated on the welding surface of the aluminum nitride sleeve to be welded and the welding surface of the aluminum nitride disk to be welded to obtain the combined component;

[0052] The raw materials for preparing the Y2O3-CaCO3-SiO2-MgO, by mass percentage, include: 1-2 wt% Y2O3 powder, 1-2 wt% CaCO3 powder, 3-5 wt% SiO2 powder, 1-3 wt% MgO powder, and the remainder being AlN powder; the particle size of the Y2O3 powder is 50-500 nm; the particle size of the CaCO3 powder is 50-500 nm; the particle size of the SiO2 powder is 0.8-1.2 μm; the particle size of the MgO powder is 50-500 nm; and the particle size of the AlN powder is 1-1.2 μm.

[0053] The preparation method of Y2O3-CaCO3-SiO2-MgO includes: ball milling each raw material at a speed of 80-160 rpm for 16-24 hours, drying it at a temperature of 100-120℃ for 18-24 hours, and then sieving it using a 150-250 mesh sieve to obtain a mixture; the mixture is then mixed with polyvinyl butyral to obtain Y2O3-CaCO3-SiO2-MgO.

[0054] Anhydrous ethanol with a purity of 98% to 99.7% is added during the ball milling process;

[0055] The amount of polyvinyl butyral added is 2-5 wt% of the mass of the mixture;

[0056] (3) The combined components are sintered in a nitrogen atmosphere at a temperature of 1500-1600℃ for 1.5-4.5 hours to obtain the aluminum nitride ceramic heating plate.

[0057] Compared with the prior art, the present invention has at least the following beneficial effects:

[0058] The welding method for the aluminum nitride ceramic heating plate provided by this invention is simple to operate. By using Y2O3-CaCO3-SiO2-MgO with a specific SiO2 content as the welding layer material, and combining it with a specific sintering temperature, efficient welding of the aluminum nitride sleeve and the aluminum nitride plate body is achieved. The resulting aluminum nitride ceramic heating plate has a leakage rate of ≤2.0×10⁻⁶. -9 mmbar / s, welding strength ≥120MPa, thermal conductivity ≥70W / mK, meeting the usage requirements. Attached Figure Description

[0059] Figure 1 This is a schematic diagram of the structure of the combined component obtained by the welding method of the aluminum nitride ceramic heating plate provided by the present invention.

[0060] In the figure: 1-Aluminum nitride sleeve to be welded; 2-Aluminum nitride disc to be welded; 3-Welding layer material. Detailed Implementation

[0061] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0062] This invention provides a welding method for an aluminum nitride ceramic heating plate, the welding method comprising the following steps:

[0063] (1) The welding surface of the aluminum nitride sleeve is subjected to a first fine grinding process and a first cleaning process to obtain the aluminum nitride sleeve to be welded; the welding surface of the aluminum nitride disc is subjected to a second fine grinding process and a second cleaning process to obtain the aluminum nitride disc to be welded.

[0064] (2) A welding layer material 3 is printed and coated on the welding surface of the aluminum nitride sleeve 1 to be welded and the welding surface of the aluminum nitride disk 2 to be welded, to obtain the assembled component, the structural schematic diagram of which is shown below. Figure 1 As shown;

[0065] The welding layer material is Y2O3-CaCO3-SiO2-MgO;

[0066] (3) The combined components are sintered to obtain the aluminum nitride ceramic heating plate.

[0067] The present invention will now be described in further detail. However, the examples described below are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims.

[0068] Example 1

[0069] This embodiment provides a welding method for an aluminum nitride ceramic heating plate, the welding method comprising the following steps:

[0070] (1) The welding surface of the aluminum nitride sleeve is subjected to a first fine grinding process and a first cleaning process to obtain the aluminum nitride sleeve to be welded; the welding surface of the aluminum nitride disc is subjected to a second fine grinding process and a second cleaning process to obtain the aluminum nitride disc to be welded.

[0071] The first fine grinding process uses 200-grit sandpaper; the first cleaning solution is deionized water; the second fine grinding process uses 900-grit sandpaper; the second cleaning solution is acetone.

[0072] (2) A total thickness of Y2O3-CaCO3-SiO2-MgO is printed and coated on the welding surface of the aluminum nitride sleeve to be welded and the welding surface of the aluminum nitride disk to be welded, to obtain the combined component;

[0073] The raw materials for preparing the Y2O3-CaCO3-SiO2-MgO, by mass percentage, include: 1.2 wt% Y2O3 powder, 1.5 wt% CaCO3 powder, 4 wt% SiO2 powder, 2.2 wt% MgO powder, with the remainder being AlN powder; the particle size of the Y2O3 powder is 100 nm; the particle size of the CaCO3 powder is 200 nm; the particle size of the SiO2 powder is 1 μm; the particle size of the MgO powder is 300 nm; and the particle size of the AlN powder is 1.1 μm.

[0074] The preparation method of Y2O3-CaCO3-SiO2-MgO includes: each raw material is ball-milled at 100 rpm for 20 h, then dried at 100℃ for 20 h, and then sieved using a 200-mesh sieve to obtain a mixture; the mixture is ball-milled with polyvinyl alcohol butyral to obtain Y2O3-CaCO3-SiO2-MgO;

[0075] Anhydrous ethanol with a purity of 99.7% is added during the ball milling process;

[0076] The amount of polyvinyl butyral added is 2.5 wt% of the mass of the mixture;

[0077] (3) The combined components are sintered at 1560°C for 3 hours in a nitrogen atmosphere to obtain the aluminum nitride ceramic heating plate.

[0078] Example 2

[0079] This embodiment provides a welding method for an aluminum nitride ceramic heating plate, the welding method comprising the following steps:

[0080] (1) The welding surface of the aluminum nitride sleeve is subjected to a first fine grinding process and a first cleaning process to obtain the aluminum nitride sleeve to be welded; the welding surface of the aluminum nitride disc is subjected to a second fine grinding process and a second cleaning process to obtain the aluminum nitride disc to be welded.

[0081] The first fine grinding process uses 100-grit sandpaper; the first cleaning solution is 99.7% anhydrous ethanol; the second fine grinding process uses 1000-grit sandpaper; the second cleaning solution is deionized water.

[0082] (2) A total thickness of Y2O3-CaCO3-SiO2-MgO is printed and coated on the welding surface of the aluminum nitride sleeve to be welded and the welding surface of the aluminum nitride disk to be welded, to obtain the combined component;

[0083] The raw materials for preparing the Y2O3-CaCO3-SiO2-MgO, by mass percentage, include: 2 wt% Y2O3 powder, 1 wt% CaCO3 powder, 5 wt% SiO2 powder, 3 wt% MgO powder, and the remainder being AlN powder; the particle size of the Y2O3 powder is 500 nm; the particle size of the CaCO3 powder is 500 nm; the particle size of the SiO2 powder is 1.2 μm; the particle size of the MgO powder is 50 nm; and the particle size of the AlN powder is 1 μm.

[0084] The preparation method of Y2O3-CaCO3-SiO2-MgO includes: each raw material is ball-milled at 160 rpm for 16 h, then dried at 120 °C for 18 h, and then sieved using a 250 mesh sieve to obtain a mixture; the mixture is then mixed with polyvinyl butyral to obtain Y2O3-CaCO3-SiO2-MgO.

[0085] Anhydrous ethanol with a purity of 98% is added during the ball milling process;

[0086] The amount of polyvinyl butyral added is 2 wt% of the mass of the mixture;

[0087] (3) The combined components are sintered at 1500°C for 4.5 hours in a nitrogen atmosphere to obtain the aluminum nitride ceramic heating plate.

[0088] Example 3

[0089] This embodiment provides a welding method for an aluminum nitride ceramic heating plate, the welding method comprising the following steps:

[0090] (1) The welding surface of the aluminum nitride sleeve is subjected to a first fine grinding process and a first cleaning process to obtain the aluminum nitride sleeve to be welded; the welding surface of the aluminum nitride disc is subjected to a second fine grinding process and a second cleaning process to obtain the aluminum nitride disc to be welded.

[0091] The first fine grinding process uses 150-grit sandpaper; the first cleaning solution is deionized water; the second fine grinding process uses 920-grit sandpaper; the second cleaning solution is deionized water.

[0092] (2) A Y2O3-CaCO3-SiO2-MgO coating with a total thickness of 50-300 μm is printed and coated on the welding surface of the aluminum nitride sleeve to be welded and the welding surface of the aluminum nitride disk to be welded to obtain the combined component;

[0093] The raw materials for preparing the Y2O3-CaCO3-SiO2-MgO, by mass percentage, include: 1.7 wt% Y2O3 powder, 1.1 wt% CaCO3 powder, 3.6 wt% SiO2 powder, 1.2 wt% MgO powder, with the remainder being AlN powder; the particle size of the Y2O3 powder is 300 nm; the particle size of the CaCO3 powder is 100 nm; the particle size of the SiO2 powder is 0.9 μm; the particle size of the MgO powder is 100 nm; and the particle size of the AlN powder is 1.05 μm.

[0094] The preparation method of Y2O3-CaCO3-SiO2-MgO includes: each raw material is ball-milled at 90 rpm for 18 hours, then dried at 104℃ for 19 hours, and then sieved using a 190-mesh sieve to obtain a mixture; the mixture is then mixed with polyvinyl butyral to obtain Y2O3-CaCO3-SiO2-MgO.

[0095] Anhydrous ethanol with a purity of 98.5% is added during the ball milling process;

[0096] The amount of polyvinyl butyral added is 3.3 wt%.

[0097] (3) The combined components are sintered at 1520°C for 3.5 hours in a nitrogen atmosphere to obtain the aluminum nitride ceramic heating plate.

[0098] Example 4

[0099] This embodiment provides a welding method for an aluminum nitride ceramic heating plate, the welding method comprising the following steps:

[0100] (1) The welding surface of the aluminum nitride sleeve is subjected to a first fine grinding process and a first cleaning process to obtain the aluminum nitride sleeve to be welded; the welding surface of the aluminum nitride disc is subjected to a second fine grinding process and a second cleaning process to obtain the aluminum nitride disc to be welded.

[0101] The first fine grinding process uses 300-grit sandpaper; the first cleaning solution is 99.7% anhydrous ethanol; the second fine grinding process uses 800-grit sandpaper; the second cleaning solution is 99.7% isopropanol.

[0102] (2) A Y2O3-CaCO3-SiO2-MgO coating with a total thickness of 50-300 μm is printed and coated on the welding surface of the aluminum nitride sleeve to be welded and the welding surface of the aluminum nitride disk to be welded to obtain the combined component;

[0103] The raw materials for preparing the Y2O3-CaCO3-SiO2-MgO, by mass percentage, include: 1 wt% Y2O3 powder, 2 wt% CaCO3 powder, 3 wt% SiO2 powder, 1 wt% MgO powder, and the remainder being AlN powder; the particle size of the Y2O3 powder is 50 nm; the particle size of the CaCO3 powder is 50 nm; the particle size of the SiO2 powder is 0.8 μm; the particle size of the MgO powder is 50 nm; and the particle size of the AlN powder is 1.2 μm.

[0104] The preparation method of Y2O3-CaCO3-SiO2-MgO includes: each raw material is ball-milled at 80 rpm for 22 h, then dried at 100℃ for 24 h, and then sieved using a 150-mesh sieve to obtain a mixture; the mixture is then mixed with polyvinyl butyral to obtain Y2O3-CaCO3-SiO2-MgO.

[0105] Anhydrous ethanol with a purity of 99.3% is added during the ball milling process;

[0106] The amount of polyvinyl butyral added is 5 wt%.

[0107] (3) The combined components are sintered at 1600°C for 1.5 hours in a nitrogen atmosphere to obtain the aluminum nitride ceramic heating plate.

[0108] Example 5

[0109] This embodiment provides a welding method for an aluminum nitride ceramic heating plate. Except for the fact that the SiO2 powder in the raw material for preparing Y2O3-CaCO3-SiO2-MgO in step (2) is 2wt%, the welding method is the same as in Example 1.

[0110] Example 6

[0111] This embodiment provides a welding method for an aluminum nitride ceramic heating plate. Except for the fact that the SiO2 powder in the raw material for preparing Y2O3-CaCO3-SiO2-MgO in step (2) is 6wt%, the welding method is the same as in Example 1.

[0112] Example 7

[0113] This embodiment provides a welding method for an aluminum nitride ceramic heating plate. Except for the sintering temperature of 1400℃ in step (3), the welding method is the same as that in embodiment 1.

[0114] Example 8

[0115] This embodiment provides a welding method for an aluminum nitride ceramic heating plate. Except for the sintering temperature of 1700℃ in step (3), the welding method is the same as that in embodiment 1.

[0116] Comparative Example 1

[0117] This comparative example provides a welding method for an aluminum nitride ceramic heating plate. The welding method is the same as that in Example 1, except that the welding layer material in step (2) does not contain SiO2.

[0118] The welding positions of the aluminum nitride ceramic heating plates obtained in the above embodiments and comparative examples were tested for helium leakage, welding strength, and thermal conductivity. The results are shown in Table 1.

[0119] Table 1

[0120] Leakage rate (mmbar / s) Welding strength (MPa) Thermal conductivity (W / mK) Example 1 <![CDATA[4.5×10 -10 ]]> 146 92 Example 2 <![CDATA[3.8×10 -10 ]]> 128 88 Example 3 <![CDATA[1.5×10 -9 ]]> 132 87 Example 4 <![CDATA[1.2×10 -9 ]]> 137 91 Example 5 <![CDATA[5.3×10 -6 ]]> 60 75 Example 6 <![CDATA[8.4×10 -7 ]]> 46 81 Example 7 <![CDATA[6.8×10 -6 ]]> 41 77 Example 8 <![CDATA[5.9×10 -6 ]]> 55 60 Comparative Example 1 <![CDATA[4.7×10 -5 ]]> 37 72

[0121] As can be seen from Table 1:

[0122] (1) As can be seen from Examples 1-4, the welding method for the aluminum nitride ceramic heating plate provided by the present invention uses Y2O3-CaCO3-SiO2-MgO as the welding layer material, which can obtain an aluminum nitride ceramic heating plate with good sealing performance, high welding strength and high thermal conductivity. The helium leakage detection rate can reach 1.2×10⁻⁶. -9 With a strength of less than mmbars and s, the welding strength can reach more than 128MPa, and the thermal conductivity can reach more than 87W / mK.

[0123] (2) Combining Examples 1 and 6, it can be seen that the SiO2 powder content in the raw materials prepared in Example 6 is relatively high, which leads to excessive melting of the welding layer material, improved fluidity of the welding layer material, and overflow from the welding position. Consequently, the welding strength of the aluminum nitride ceramic heating plate is low, with a welding strength of only 46 MPa. Moreover, the helium leakage detection rate is high, at 8.4 × 10⁻⁶. - 7 mmbar / s;

[0124] (3) Combining Examples 1 and 7-8, it can be seen that the sintering temperature of 1400℃ in Example 7 leads to incomplete melting of the weld layer material, poor wettability of the two weld surfaces, and the inability of the solder to fill the weld gap well. The lower temperature makes it difficult to remove the gas from the weld, and the residual gas forms pores, resulting in poor bonding between the two weld surfaces. Ultimately, this results in poor sealing of the joint after welding and a high helium leakage detection rate of 6.8×10⁻⁶. -6 The weld strength is low, only 41 MPa, and the thermal conductivity is also low. In Example 8, the sintering temperature is 1700℃, which will cause grain growth in the two base materials and reduce the thermal conductivity of the matrix. At the same time, the weld area will be overburned, the hardness and brittleness of the weld area will increase, and the strength will be low. The higher temperature may also cause excessive evaporation or loss of the solder, making it impossible to form a high-quality weld area.

[0125] (4) Combining Example 1 and Comparative Example 1, it can be seen that the welding layer material in Comparative Example 1 does not contain SiO2, resulting in a higher melting point of the welding layer material. This leads to performance loss of the aluminum nitride ceramic material during the welding process, and a higher helium leakage detection rate of 4.7 × 10⁻⁶. -5 The weld strength is significantly reduced to only 37 MPa due to the low temperature and pressure (mmbar / s), and the thermal conductivity is also low.

[0126] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A welding method of an aluminum nitride ceramic heating disc, characterized by, The welding method comprises the following steps: (1) the welding surface of the aluminum nitride sleeve is sequentially subjected to first fine grinding and first cleaning to obtain an aluminum nitride sleeve to be welded; the welding surface of the aluminum nitride disc body is sequentially subjected to second fine grinding and second cleaning to obtain an aluminum nitride disc body to be welded; (2) a welding layer material is printed on the welding surface of the aluminum nitride sleeve to be welded and the welding surface of the aluminum nitride disc body to be welded to obtain a combined component; The welding layer material is Y2O3-CaCO3-SiO2-MgO; The preparation raw materials of the Y2O3-CaCO3-SiO2-MgO in step (2) comprise, in mass percentage: 1-2wt% Y2O3 powder, 1-2wt% CaCO3 powder, 3-5wt% SiO2 powder, 1-3wt% MgO powder, and the rest is AlN powder; The particle size of the Y2O3 powder is 50-500nm; The particle size of the CaCO3 powder is 50-500nm; The particle size of the SiO2 powder is 0.8-1.2μm; The particle size of the MgO powder is 50-500nm; The particle size of the AlN powder is 1-1.2μm; The preparation method of the Y2O3-CaCO3-SiO2-MgO in step (2) comprises: After each preparation raw material is subjected to ball milling treatment, it is sequentially subjected to drying and screening treatment to obtain a mixture; the mixture is mixed with polyvinyl butyl to obtain Y2O3-CaCO3-SiO2-MgO; The addition amount of the polyvinyl butyl is 2-5wt% of the mass of the mixture; The total thickness of the printed and coated welding layer material in step (2) is 50-300μm; (3) the combined component is subjected to sintering treatment to obtain the aluminum nitride ceramic heating disc; The sintering treatment in step (3) is carried out in a nitrogen atmosphere; The temperature of the sintering treatment in step (3) is 1500-1600℃; and the time of the sintering treatment is 1.5-4.5h.

2. The welding method according to claim 1, characterized in that, The first fine grinding in step (1) adopts 100-300 mesh sandpaper polishing.

3. The welding method of claim 1, wherein, The cleaning solution for the first cleaning comprises deionized water or 99.7% anhydrous ethanol.

4. The welding method of claim 1, wherein, The second fine grinding adopts 800-1000 mesh sandpaper polishing.

5. The welding method of claim 1, wherein, The cleaning solution for the second cleaning comprises any one of deionized water, acetone or 99.7% isopropanol.

6. The welding method of claim 1, wherein, Anhydrous ethanol with a purity of 98%-99.7% is added during the ball milling treatment.

7. The welding method of claim 1, wherein, The rotation speed of the ball milling treatment is 80-160rpm.

8. The welding method of claim 1, wherein, The time of the ball milling treatment is 16-24h.

9. The welding method of claim 1, wherein, The temperature of the drying is 100-120℃.

10. The welding method of claim 1, wherein, The time of the drying is 18-24h.

11. The welding method of claim 1, wherein, The screening treatment is performed using a 150-250 mesh screen.

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