Welding method of aluminum nitride ceramic heating plate

Abstract

The invention provides a welding method of an aluminum nitride ceramic heating plate, which comprises the following steps of: firstly, accurately grinding and cleaning a welding surface of an aluminum nitride sleeve and a welding surface of an aluminum nitride plate body, and then printing and coating a welding layer material Y2O3-CaCO3-SiO2-MgO on the welding surface of the aluminum nitride sleeve and the welding surface of the aluminum nitride plate body; and finally sintering to obtain the aluminum nitride ceramic heating plate with good sealing performance, high welding strength and high heat conductivity, and the aluminum nitride ceramic heating plate is suitable for large-scale popularization and application.

Description

Technical Field

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

[0002] Aluminum nitride ceramics have excellent heat dissipation, stability, and insulation, and are widely used in semiconductors, intelligent power components, automotive electronics, solar energy and other fields. In the semiconductor manufacturing process, aluminum nitride ceramic heaters are needed to heat the wafers so that CVD has a better effect and a more uniform film is obtained. Aluminum nitride ceramics have high hardness and are relatively brittle, so complex parts are mostly made separately and connected by welding. Aluminum nitride ceramic heaters are mostly used in vacuum environments, and have high requirements for the sealing of the connection between the disk and the sleeve; during use, the sleeve plays a stable supporting role for the disk, so the connection part needs to have good bonding strength to ensure stability during use and avoid breakage; it is also necessary to consider the difference between the thermal conductivity of the welding part and the thermal conductivity of the disk and sleeve materials, so as not to affect the temperature uniformity of the disk surface.

[0003] At present, the welding of ceramic materials mainly adopts the following methods: adding a metallization layer or a solder layer between the required connecting parts, melting the metallization layer or the solder layer at high temperature, and the melted solder layer infiltrates the welding surface of the parts. During the insulation process, the material diffuses between the parts to achieve the connection of the parts. Since aluminum nitride ceramic heaters have clear requirements for the thermal conductivity and volume resistivity of materials, the thermal conductivity and volume resistivity of materials are closely related to the grain size. If a higher welding temperature is used between parts, the grain size of the aluminum nitride ceramic material will change, and internal defects are prone to occur inside the disc and sleeve. Therefore, it is necessary to develop low melting point solders to achieve the connection of ceramic parts and ensure the bonding strength, sealing and insulation of the connection position.

[0004] CN114012255A discloses a ceramic welding method for solving the technical problem of low connection force between ceramic workpieces. The joining end faces of two ceramic workpieces to be welded are electroplated, and solder is filled between the cross-sections. The solder includes ceramic powder. The solder is heated so that the ceramic powder forms a sintered body connecting the end faces to achieve a tight connection of the workpieces.

[0005] CN113173797A discloses an Al2O3-based ceramic welding sealing component and a preparation method thereof, wherein tungsten powder, titanium powder, molybdenum oxide, boron oxide, yttrium oxide and an organic binder are uniformly mixed to obtain a metallization paste, which is uniformly coated on both ends of a ceramic substrate by screen printing, and a sealing member is obtained after sintering in a vacuum furnace.

[0006] CN113185314A discloses a boron nitride-based ceramic welding sealing component and a preparation method thereof. The boron nitride-based ceramic welding sealing component comprises a ceramic substrate and a metallization layer, wherein the ceramic substrate is made of inorganic fiber-boron nitride three-dimensional network substrate, yttrium oxide, silicon oxide, titanium oxide, additives, binders and dispersants, and is prepared through the steps of inorganic fiber-boron nitride three-dimensional network substrate preparation, mixing, granulation, primary sintering and secondary sintering; the raw materials of the metallization layer include titanium powder, tungsten powder, molybdenum oxide, boron oxide, aluminum oxide and an organic binder.

[0007] In the above-mentioned ceramic welding method, metal powder and / or oxide are added to the welding layer material. The metal elements in the metal powder in the welding layer material diffuse to both ends during the welding process. When used in aluminum nitride ceramic heaters, it is easy to cause changes in the thermal conductivity and volume resistivity of the ceramic material. The welding layer formed by the oxide in the welding layer material requires a higher welding temperature. When used in an aluminum nitride heating plate, it is easy to cause changes in the grain size of the aluminum nitride ceramic material, and internal defects are easy to occur inside the plate body and sleeve, and the thermal conductivity and volume resistivity are reduced. Summary of the invention

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

[0009] To achieve this object, the present invention adopts the following technical solutions:

[0010] The present 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 in sequence to obtain an 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 in sequence to obtain an aluminum nitride disc to be welded;

[0012] (2) printing and coating a welding layer material on the welding surface of the aluminum nitride sleeve to be welded and the welding surface of the aluminum nitride disc 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 of the aluminum nitride ceramic heating plate of the present invention firstly grinds and cleans the welding surface of the aluminum nitride sleeve and the welding surface of the aluminum nitride disc body. The function of the grinding process is to reduce the surface roughness, improve the adhesion of the welding layer material, reduce the unevenness of the welding area, reduce the stress concentration of the welding process, and ensure the uniform load transmission after welding. The function of the cleaning process is to remove the dirt and oil stains on the surface, prevent defects such as pore inclusions in welding, prevent cracks due to inclusions in the weld, and ensure the welding quality; then, Y2O3-CaCO3-SiO2-MgO is used as the welding layer material, and the melting point of the welding layer material is reduced by adding SiO2, so as to avoid the performance loss of the aluminum nitride ceramic material during high-temperature welding, so that the welding layer material is easy to form a liquid phase between the welding surfaces, wet the welding surface, and then facilitate the aluminum nitride sleeve and the aluminum nitride disc body to form a tighter connection after sintering, and have a higher welding strength. In addition, the welding layer material avoids the uneven temperature of the aluminum nitride ceramic heating plate product, and prevents the aluminum nitride ceramic heating plate from cracking due to repeated heating and cooling in subsequent use.

[0016] Preferably, the first fine grinding in step (1) is performed using 100-300 mesh sandpaper, for example, 100 mesh, 110 mesh, 150 mesh, 180 mesh, 200 mesh, 250 mesh or 300 mesh, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

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

[0018] Preferably, the second fine grinding process uses 800-1000 mesh sandpaper for grinding, for example, it can be 800 mesh, 810 mesh, 850 mesh, 880 mesh, 900 mesh, 950 mesh or 1000 mesh, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

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

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

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

[0022] 1-2wt% CaCO3 powder can be, for example, 1wt%, 1.1wt%, 1.3wt%, 1.5wt%, 1.6wt%, 1.8wt% or 2wt%, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0023] 3-5wt% SiO2 powder can be, for example, 3wt%, 3.1wt%, 3.3wt%, 3.5wt%, 4wt%, 4.5wt% or 5wt%, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0024] The present invention preferably includes 3-5wt% SiO2 powder in the Y2O3-CaCO3-SiO2-MgO welding layer material. When less than 3wt% SiO2 powder is added, the SiO2 powder has a lower influence on the melting point of the welding layer material, the densification degree after sintering is poor, the sealing of the welding position is poor, and the leakage rate is greater than 1.0×10 -7 mmbar / s; when adding more than 5wt% SiO2 powder, the welding layer material will be over-melted, the fluidity of the welding layer material will improve, and it will overflow from the welding position, which will lead to a lower welding strength of the aluminum nitride ceramic heating plate, and the welding strength is ≤50MPa.

[0025] 1-3wt% MgO powder, for example, can be 1wt%, 1.5wt%, 1.8wt%, 2wt%, 2.5wt%, 2.8wt% or 3wt%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable; the rest is AlN powder.

[0026] Preferably, the particle size of the Y2O3 powder is 50 to 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 is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0027] Preferably, the particle size of the CaCO3 powder is 50 to 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 is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0028] Preferably, the particle size of the SiO2 powder is 0.8-1.2 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, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

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

[0030] Preferably, the particle size of the AlN powder is 1-1.2 μm, for example, 1 μm, 1.05 μm, 1.07 μm, 1.09 μm, 1.1 μm, 1.13 μm, 1.15 μm or 1.2 μm, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

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

[0032] After ball milling, each prepared raw material is dried and sieved in sequence to obtain a mixed material; the mixed material is 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%, etc., but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0034] The present invention preferably adds anhydrous ethanol with a purity of 98% to 99.7% during the ball milling process. Compared with dry ball milling, it 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 the particles, so that powder particles of different particle sizes and densities can be fully mixed and dispersed. At the same time, the agglomeration phenomenon of dry powder caused by electrostatic effect during the mixing process can be avoided, and a more fine and uniform particle mixture can be obtained.

[0035] Preferably, the rotation speed of the ball milling treatment 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 is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

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

[0038] Preferably, the drying time is 18 to 24 hours, for example, 18 hours, 20 hours, 22 hours, 23 hours, 23.5 hours or 24 hours, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0039] Preferably, the screening process is carried out using a 150-250 mesh sieve, for example, it can be 150 mesh, 160 mesh, 170 mesh, 200 mesh, 210 mesh, 230 mesh, 240 mesh or 250 mesh, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

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

[0041] The present invention preferably adds 2-5wt% of the mass of the mixed material, which has the advantages of good slurry bonding strength, uniform slurry and easy coating. When the amount of polyvinyl butyral added is small, it will cause the slurry to be difficult to coat after mixing, and the sample will fall off due to poor bonding ability, and the sample will be difficult to assemble and fix in position; when the amount of polyvinyl butyral added is large, the slurry will be hard and brittle after mixing, difficult to coat, and the pores inside the slurry will increase and cannot be effectively discharged, affecting the welding quality.

[0042] Preferably, the total thickness of the printed and coated welding layer material 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, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0043] The present invention preferably has a total thickness of 50 to 300 μm for the printed and coated welding layer material, which refers to the thickness between the sleeve welding surface and the disc body welding surface; this specific thickness range has the advantages of ensuring welding strength, ensuring welding sealing and avoiding welding defects. When the total thickness of the printed and coated welding layer material is thin, it will lead to insufficient solder to fill the gap, low strength of the welding position, poor sealing of the welding part, and the solder layer is too thin to wet the two welding surfaces required for welding, resulting in poor welding quality; when the total thickness of the printed and coated welding layer material is thick, it will lead to the strength of the welding area being lower than the welding material, resulting in poor weld strength, and the solder layer is too thick. During the cooling process after welding, the thermal stress difference is obvious, which can easily cause weld cracking, and the welding layer is prone to defects such as pores, which become the source of cracking.

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

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

[0046] The preferred sintering temperature of the present invention is 1500-1600°C, which prevents the high-temperature welding process from affecting the material properties of the aluminum nitride ceramic heating plate, and forms a tighter connector to ensure that the sealing, welding strength and thermal conductivity of the aluminum nitride ceramic heating plate meet the product requirements. When the sintering temperature is low, the welding layer material will not be completely melted, the wettability of the two welding surfaces will be poor, the solder will not be able to fill the welding gap well, the gas in the weld will be difficult to drive out at a low temperature, and the residual gas will form pores, resulting in poor bonding between the two welding surfaces, and ultimately resulting in poor sealing of the joint after welding and low weld strength; when the sintering temperature is high, the grains in the two welding base materials will grow, the thermal conductivity of the matrix will decrease, and the weld area will be overburned, the hardness and brittleness of the weld area will increase, and the strength will be low. Higher temperatures may also cause excessive evaporation or loss of solder, and a high-quality weld area cannot be formed.

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

[0048] As a preferred technical solution of the present invention, the welding method comprises 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 in sequence to obtain an 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 in sequence to obtain an aluminum nitride disc to be welded;

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

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

[0052] In terms of mass percentage, the raw materials for preparing the Y2O3-CaCO3-SiO2-MgO include: 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;

[0053] The preparation method of Y2O3-CaCO3-SiO2-MgO comprises: each raw material is subjected to ball milling treatment at a rotation speed of 80 to 160 rpm for 16 to 24 hours, and then dried at a temperature of 100 to 120° C. for 18 to 24 hours, and then sieved using a 150 to 250 mesh screen to obtain a mixed material; the mixed material is mixed with polyvinyl butyral to obtain Y2O3-CaCO3-SiO2-MgO;

[0054] During the ball milling process, anhydrous ethanol with a purity of 98% to 99.7% is added;

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

[0056] (3) The combined component is sintered in a nitrogen atmosphere at a temperature of 1500-1600° C. 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 of the aluminum nitride ceramic heating plate provided by the present invention is simple to operate. By adopting Y2O3-CaCO3-SiO2-MgO with a specific SiO2 content as the welding layer material and combining it with a specific sintering treatment temperature, efficient welding of the aluminum nitride sleeve and the aluminum nitride plate body is achieved. The leakage rate of the obtained aluminum nitride ceramic heating plate is ≤2.0×10 -9 mmbar / s, welding strength ≥120MPa, thermal conductivity ≥70W / mK, which meets the use requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 It is a structural schematic diagram of a 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 DESCRIPTION

[0061] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0062] The present 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 in sequence to obtain an 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 in sequence to obtain an aluminum nitride disc to be welded;

[0064] (2) Print and apply welding layer material 3 on the welding surface of the aluminum nitride sleeve 1 to be welded and the welding surface of the aluminum nitride disc 2 to be welded to obtain a combined component, the structural schematic diagram of which is shown in FIG. 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 is further described in detail below. However, the following examples are only 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 shall be subject to 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 in sequence to obtain an 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 in sequence to obtain an aluminum nitride disc to be welded;

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

[0072] (2) printing and coating Y2O3-CaCO3-SiO2-MgO with a total thickness of 50 μm on the welding surface of the aluminum nitride sleeve to be welded and the welding surface of the aluminum nitride disc to be welded to obtain a combined component;

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

[0074] The preparation method of Y2O3-CaCO3-SiO2-MgO comprises: each raw material is subjected to ball milling treatment at a rotation speed of 100 rpm for 20 hours, and then dried at a temperature of 100°C for 20 hours, and then sieved using a 200-mesh screen to obtain a mixed material; the mixed material is mixed with polyvinyl alcohol ball milled butyral to obtain Y2O3-CaCO3-SiO2-MgO;

[0075] During the ball milling process, anhydrous ethanol with a purity of 99.7% is added;

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

[0077] (3) The combined component is sintered at a temperature of 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 in sequence to obtain an 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 in sequence to obtain an aluminum nitride disc to be welded;

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

[0082] (2) printing and coating Y2O3-CaCO3-SiO2-MgO with a total thickness of 200 μm on the welding surface of the aluminum nitride sleeve to be welded and the welding surface of the aluminum nitride disc to be welded to obtain a combined component;

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

[0084] The preparation method of Y2O3-CaCO3-SiO2-MgO comprises: each raw material is subjected to ball milling treatment at a rotation speed of 160 rpm for 16 hours, and then dried at a temperature of 120° C. for 18 hours, and then sieved using a 250-mesh screen to obtain a mixed material; the mixed material is mixed with polyvinyl butyral to obtain Y2O3-CaCO3-SiO2-MgO;

[0085] During the ball milling process, anhydrous ethanol with a purity of 98% is added;

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

[0087] (3) The combined component is sintered in a nitrogen atmosphere at a temperature of 1500° C. for 4.5 hours 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 in sequence to obtain an 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 in sequence to obtain an aluminum nitride disc to be welded;

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

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

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

[0094] The preparation method of Y2O3-CaCO3-SiO2-MgO comprises: each raw material is subjected to ball milling treatment at a rotation speed of 90 rpm for 18 hours, and then dried at a temperature of 104° C. for 19 hours, and then sieved using a 190-mesh screen to obtain a mixed material; the mixed material is mixed with polyvinyl butyral to obtain Y2O3-CaCO3-SiO2-MgO;

[0095] During the ball milling process, anhydrous ethanol with a purity of 98.5% is added;

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

[0097] (3) The combined component is sintered at a temperature of 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 in sequence to obtain an 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 in sequence to obtain an aluminum nitride disc to be welded;

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

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

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

[0104] The preparation method of Y2O3-CaCO3-SiO2-MgO comprises: each raw material is subjected to ball milling treatment at a rotation speed of 80 rpm for 22 hours, and then dried at a temperature of 100°C for 24 hours, and then sieved using a 150-mesh screen to obtain a mixed material; the mixed material is mixed with polyvinyl butyral to obtain Y2O3-CaCO3-SiO2-MgO;

[0105] During the ball milling process, anhydrous ethanol with a purity of 99.3% is added;

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

[0107] (3) The combined component is sintered in a nitrogen atmosphere at a temperature of 1600° C. for 1.5 hours 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. The welding method is the same as that of Embodiment 1 except that in step (2), the SiO2 powder in the preparation raw material of Y2O3-CaCO3-SiO2-MgO is 2 wt%.

[0110] Example 6

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

[0112] Example 7

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

[0114] Example 8

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

[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 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-mentioned embodiments and comparative examples were subjected to helium leakage detection, welding strength detection and thermal conductivity detection. The results are shown in Table 1.

[0119] Table 1

[0120] Leak 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] From Table 1 we can see that:

[0122] (1) It can be seen from Examples 1 to 4 that the welding method of the aluminum nitride ceramic heating plate provided by the present invention uses Y2O3-CaCO3-SiO2-MgO as the welding layer material to obtain an aluminum nitride ceramic heating plate with good sealing, high welding strength and high thermal conductivity, and the helium leakage detection rate can reach 1.2×10 -9 mmbar / s or less, the welding strength can reach more than 128MPa, and the thermal conductivity can reach more than 87W / mK;

[0123] (2) Combining Example 1 and Example 6, it can be seen that the SiO2 powder content in the raw material prepared in Example 6 is relatively high, which causes the welding layer material to be over-melted, and the fluidity of the welding layer material becomes better, and overflows from the welding position, which leads to a low welding strength of the aluminum nitride ceramic heating plate, which is only 46MPa, and a high helium leak detection rate of 8.4×10 - 7 mmbar / s;

[0124] (3) Combining Example 1 with Examples 7 to 8, it can be seen that the sintering temperature in Example 7 is 1400°C, which will result in the welding layer material not being completely melted, the wettability of the two welding surfaces is poor, the solder cannot fill the welding gap well, the gas in the weld is difficult to be driven out at a low temperature, and the residual gas forms pores, resulting in poor bonding between the two welding surfaces, and ultimately poor sealing of the joint after welding. The helium leak detection rate is high, which is 6.8×10 -6 mmbar / s, the welding strength is low, only 41MPa, and the thermal conductivity is also low; the sintering temperature in Example 8 is 1700°C, which will cause the grains in the two welding base materials to grow, the thermal conductivity of the matrix to decrease, and the weld area will be overburned, the hardness and brittleness of the weld area will increase, and the strength will be low. Higher temperatures may also cause excessive evaporation or loss of solder, and it is impossible to form a high-quality weld area;

[0125] (4) It can be seen from the combination of Example 1 and Comparative Example 1 that the welding layer material of Comparative Example 1 does not contain SiO2, resulting in a higher melting point of the welding layer material, which in turn causes the performance loss of the aluminum nitride ceramic material during the welding process, and the helium leak detection rate is relatively high, which is 4.7×10 -5 mmbar / s, the welding strength is greatly reduced to only 37MPa, and the thermal conductivity is also low.

[0126] The applicant declares that the above is only a specific implementation mode 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 thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A welding method for an aluminum nitride ceramic heating plate, characterized in that: The welding method comprises the following steps: (1) The welding surface of the aluminum nitride sleeve is subjected to a first fine grinding process and a first cleaning process in sequence to obtain an 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 in sequence to obtain an aluminum nitride disc to be welded; (2) printing and coating a welding layer material on the welding surface of the aluminum nitride sleeve to be welded and the welding surface of the aluminum nitride disc to be welded to obtain a combined component; The welding layer material is Y2O3-CaCO3-SiO2-MgO; (3) The combined components are sintered to obtain the aluminum nitride ceramic heating plate.

2. The welding method according to claim 1, characterized in that: Step (1) The first fine grinding process is performed by using 100-300 mesh sandpaper; Preferably, the cleaning solution of the first cleaning comprises deionized water or 99.7% anhydrous ethanol; Preferably, the second fine grinding process is performed by grinding with 800-1000 grit sandpaper; Preferably, the cleaning solution for the second cleaning includes any one of deionized water, acetone or 99.7% isopropyl alcohol.

3. The welding method according to claim 1 or 2, characterized in that: In terms of mass percentage, the raw materials for preparing Y2O3-CaCO3-SiO2-MgO in step (2) include: 1-2wt% Y2O3 powder, 1-2wt% CaCO3 powder, 3-5wt% SiO2 powder, 1-3wt% MgO powder, and the rest is AlN powder; Preferably, the particle size of the Y2O3 powder is 50 to 500 nm; Preferably, the particle size of the CaCO3 powder is 50 to 500 nm; Preferably, the particle size of the SiO2 powder is 0.8 to 1.2 μm; Preferably, the particle size of the MgO powder is 50 to 500 nm; Preferably, the particle size of the AlN powder is 1 to 1.2 μm.

4. The welding method according to claim 3, characterized in that: The preparation method of Y2O3-CaCO3-SiO2-MgO in step (2) comprises: After ball milling, each prepared raw material is dried and sieved in sequence to obtain a mixed material; the mixed material is mixed with polyvinyl butyral to obtain Y2O3-CaCO3-SiO2-MgO.

5. The welding method according to claim 4, characterized in that: During the ball milling process, anhydrous ethanol with a purity of 98% to 99.7% is added; Preferably, the rotation speed of the ball milling treatment is 80 to 160 rpm; Preferably, the ball milling treatment time is 16 to 24 hours; Preferably, the drying temperature is 100-120°C; Preferably, the drying time is 18 to 24 hours; Preferably, the screening process is performed using a 150-250 mesh sieve.

6. The welding method according to claim 4 or 5, characterized in that: The added amount of the polyvinyl butyral is 2-5 wt % of the mass of the mixed material.

7. The welding method according to any one of claims 1 to 6, characterized in that: The total thickness of the printed and coated welding layer material in step (2) is 50 to 300 μm.

8. The welding method according to any one of claims 1 to 7, characterized in that: The sintering treatment in step (3) is carried out in a nitrogen atmosphere.

9. The welding method according to any one of claims 1 to 8, characterized in that: The sintering temperature in step (3) is 1500-1600° C. Preferably, the sintering treatment time is 1.5 to 4.5 hours.

10. The welding method according to any one of claims 1 to 9, characterized in that: The welding method comprises the following steps: (1) The welding surface of the aluminum nitride sleeve is subjected to a first fine grinding process and a first cleaning process in sequence to obtain an 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 in sequence to obtain an aluminum nitride disc to be welded; The first fine grinding process uses 100-300 mesh sandpaper for grinding; the first cleaning solution includes deionized water or 99.7% anhydrous ethanol; the second fine grinding process uses 800-1000 mesh sandpaper for grinding; the second cleaning solution includes any one of deionized water, acetone or 99.7% isopropyl alcohol; (2) printing and coating Y2O3-CaCO3-SiO2-MgO with a total thickness of 50 to 300 μm on the welding surface of the aluminum nitride sleeve to be welded and the welding surface of the aluminum nitride disc to be welded to obtain a combined component; In terms of mass percentage, the raw materials for preparing the Y2O3-CaCO3-SiO2-MgO include: 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 Y2O3-CaCO3-SiO2-MgO comprises: each raw material is subjected to ball milling treatment at a rotation speed of 80 to 160 rpm for 16 to 24 hours, and then dried at a temperature of 100 to 120° C. for 18 to 24 hours, and then sieved using a 150 to 250 mesh screen to obtain a mixed material; the mixed material is mixed with polyvinyl butyral to obtain Y2O3-CaCO3-SiO2-MgO; During the ball milling process, anhydrous ethanol with a purity of 98% to 99.7% is added; The amount of polyvinyl butyral added is 2-5wt% of the mass of the mixed material; (3) The combined component is sintered in a nitrogen atmosphere at a temperature of 1500-1600° C. for 1.5-4.5 hours to obtain the aluminum nitride ceramic heating plate.

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