Glass solder for joining aluminum nitride ceramics and method of making and use thereof

Abstract

The present application relates to a kind of glass solder for connecting aluminum nitride ceramic and its preparation method and application.The chemical composition of the glass solder for connecting aluminum nitride ceramic includes: 60-65wt.% ZnO, 20-25wt.% B2O3, 10-13wt.% SiO2 and 2-5wt.% Al2O3, and the sum of the mass percentage of each component is 100wt.%.

Description

Technical Field

[0001] This invention relates to a glass solder for joining aluminum nitride ceramics, its preparation method and application, belonging to the field of ceramic material welding. Background Technology

[0002] Aluminum nitride (AlN) ceramics are currently the most ideal high-performance ceramic substrates and packaging materials due to their high thermal conductivity, high chemical stability, low dielectric constant and low dielectric loss, good insulation properties, and thermal expansion coefficient matching that of silicon wafers. Simultaneously, this material is also widely used in the semiconductor industry, especially in electrostatic chucks and ceramic heaters, and is replacing alumina ceramics as the mainstream material system. However, due to the inherent brittleness of ceramic materials and limitations in current manufacturing techniques, they are difficult to directly process into applicable complex components, which to some extent restricts their applications. Welding technology is an effective technical route to solve the engineering manufacturing challenges of complex configurations and large-size ceramic components.

[0003] Current ceramic joining technologies include active metal joining, glass joining, and diffusion joining. Among these, glass solder joining is a simple, feasible, and low-cost method. Glass solder has excellent chemical compatibility with the ceramic matrix, and the poor matching of thermal expansion coefficients with the ceramic matrix can be improved by adjusting the composition, thereby enhancing the joint strength and connection quality. Furthermore, since metal heating elements are typically arranged within aluminum nitride electrostatic chucks, the high insulation properties of glass solder are highly beneficial for electrode arrangement. However, there are few reports on the use of glass solder to join aluminum nitride ceramics in electrostatic chucks and ceramic heaters. Existing welding techniques also suffer from drawbacks such as thermal expansion coefficient mismatch, the metal weld interface affecting the insulation performance of the chuck heating components, low connection strength, and poor airtightness, severely restricting the manufacturing and industrial application of aluminum nitride electrostatic chucks. Summary of the Invention

[0004] To address the aforementioned problems, this invention proposes a method for joining aluminum nitride ceramics using glass solder. By adjusting the composition of the glass solder, a coefficient of thermal expansion that closely matches that of the aluminum nitride ceramic can be obtained. Simultaneously, the interface exhibits excellent insulation properties, avoiding the challenges of heater placement in electrostatic chucks. Furthermore, this joining technology can produce aluminum nitride ceramic joints with excellent strength at both room temperature and high temperature. The process is simple, has high engineering application requirements, and shows great promise for future applications.

[0005] In a first aspect, the present invention provides a glass solder for joining aluminum nitride ceramics, wherein the chemical composition of the glass solder for joining aluminum nitride ceramics comprises: 60-65 wt.% ZnO, 20-25 wt.% B2O3, 10-13 wt.% SiO2 and 2-5 wt.% Al2O3, and the sum of the mass percentages of each component is 100 wt%.

[0006] Preferably, the glass solder is in powder form with a particle size of 100 nm to 75 μm.

[0007] Preferably, the glass solder has a glass transition temperature of 560–570°C and a softening point of 610–620°C.

[0008] Preferably, the coefficient of thermal expansion of the glass solder between 20 and 400°C is (3.8 to 4.0) × 10⁻⁶. -6 K -1 It matches the coefficient of thermal expansion of aluminum nitride ceramics.

[0009] Secondly, the present invention provides a method for preparing a glass solder for joining aluminum nitride ceramics, comprising:

[0010] (1) Weigh ZnO powder, H3BO3 powder, SiO2 powder and Al2O3 powder and mix them to obtain a mixture;

[0011] (2) After placing the mixture in a crucible, put it into a muffle furnace, then heat it to the melting temperature and hold it thereto obtain a molten sample;

[0012] (3) After the molten sample is directly poured into deionized water and rapidly cooled to obtain a block glass sample, it is then crushed and powdered to obtain the glass solder.

[0013] Preferably, in step (1), the purity of the ZnO powder, SiO2 powder, and Al2O3 powder is ≥99.0%; the purity of the H3BO3 is ≥99.5%; and the average particle size of the ZnO powder, H3BO3 powder, SiO2 powder, and Al2O3 powder is 5-10 μm.

[0014] The mixing method is wet ball milling; the parameters of the wet ball milling include: the mixing medium is alcohol, the grinding ball material is alumina ceramic balls, the rotation speed is 300-600 rpm, and the time is 8-10 hours.

[0015] Preferably, after wet ball milling, the material is dried, ground, and sieved; the drying temperature is 60°C and the drying time is 2 hours; the sieving is done through an 80-mesh sieve.

[0016] Preferably, in step (2), the melting temperature is 1400-1500°C; more preferably, the heating rate is 5-10°C / min, and more preferably 10°C / min.

[0017] The heat preservation treatment lasts for 1 to 2 hours.

[0018] Preferably, in step (3), a planetary ball mill is used for crushing and grinding; the parameters of the planetary ball mill include: deionized water as the grinding medium, alumina balls as grinding balls, a rotation speed of 300 to 600 rpm, and a ball milling time of 6 to 8 hours, preferably 8 hours;

[0019] Preferably, after crushing and grinding, the material is dried and sieved. The drying temperature is 100°C and the time is 2 hours. The sieving is done through a 200-mesh sieve.

[0020] Thirdly, the present invention provides a method for producing aluminum nitride ceramics, comprising:

[0021] (1) A glass solder for connecting aluminum nitride ceramics is mixed with an organic solution to obtain a glass slurry;

[0022] (2) The obtained glass paste is uniformly coated on the surface of aluminum nitride ceramic by screen printing to obtain a glass paste layer and then dried to obtain aluminum nitride ceramic with a glass solder layer on the surface.

[0023] (3) Fix the aluminum nitride ceramic coated with glass solder layer and the uncoated aluminum nitride ceramic with a clamp, then perform welding treatment, and let it cool naturally to room temperature in the furnace to complete the connection of aluminum nitride ceramics and obtain aluminum nitride ceramic joint.

[0024] Preferably, the binder of the organic solution in step (1) is at least one of ethyl cellulose, methyl cellulose, polyvinyl alcohol and phenolic resin, and the solvent is selected from at least one of terpineol, triterpenol, ethyl acetate and butyl acetate; the content of the binder in the organic solution is 3 to 10 wt%, preferably 5 wt%.

[0025] The amount of the organic solution used is 20-25 wt.% of the glass solder mass.

[0026] Preferably, the drying temperature is 80-100°C and the time is 30-60 minutes; more preferably, it is dried in an oven at 100°C for 30 minutes.

[0027] The thickness of the glass slurry layer is 50–300 μm, preferably 100–200 μm.

[0028] Preferably, the welding process is performed at a temperature of 700–800°C for 30–60 minutes.

[0029] Among them, the glass solder layer formed by the glass solder layer after it is naturally cooled to room temperature in the furnace is in an amorphous state.

[0030] Fourthly, the present invention provides an aluminum nitride ceramic connector prepared according to the above method, wherein the aluminum nitride ceramic connector has a room temperature three-point bending strength ≥190MPa, a high temperature three-point bending strength ≥160MPa at 450℃, and a helium leakage rate <5×10⁻⁶. -11 Pa·m 3 / S, resistivity of weld interface >5×10 13 Ω·cm.

[0031] Fifthly, the present invention provides an application of a glass solder for connecting aluminum nitride ceramics in welding aluminum nitride ceramics, wherein the aluminum nitride ceramic is an aluminum nitride electrostatic chuck used in the semiconductor industry.

[0032] In a sixth aspect, the present invention provides a glass solder sheet comprising the above-described glass solder for joining aluminum nitride ceramics and an adhesive;

[0033] Preferably, the adhesive is selected from at least one of ethyl cellulose, methyl cellulose, polyvinyl alcohol, and phenolic resin;

[0034] Preferably, the mass ratio of the adhesive to the glass solder for connecting aluminum nitride ceramics is 1:(20-100);

[0035] The thickness of the glass sheet is 50–300 μm, preferably 100–200 μm.

[0036] In a seventh aspect, the present invention provides an application of a glass solder pad in welding aluminum nitride ceramics, characterized in that the aluminum nitride ceramic is an aluminum nitride electrostatic chuck for the semiconductor industry.

[0037] Beneficial effects:

[0038] The ZnO-B2O3-SiO2-Al2O3 glass solder used in this invention has excellent chemical compatibility with the aluminum nitride ceramic matrix, and its coefficient of thermal expansion at 20-400℃ is (3.8-4.0)×10⁻⁶. -6 K -1 It is compatible with the thermal expansion coefficient of the aluminum nitride substrate to be connected, which effectively improves the connection quality of aluminum nitride ceramics.

[0039] The ZnO-B2O3-SiO2-Al2O3 glass solder used in this invention enables the joining of aluminum nitride ceramics at 700-800℃, reducing the process difficulty of aluminum nitride ceramic joining. The aluminum nitride ceramic joint joined with this glass solder achieves a three-point bending strength of over 190MPa at room temperature and over 160MPa at 450℃. The helium leakage of the aluminum nitride ceramic joint is less than 5×10⁻⁶. -11 Pa·m 3 / S, resistivity of the weld interface is higher than 5×10 13 It has an insulation strength of Ω·cm and exhibits excellent insulation properties.

[0040] The glass welding process used in this invention is stable, reliable, and easy to operate, and has significant application value. It is suitable for industrial production, especially for welding electrostatic chucks used in the semiconductor industry. Attached Figure Description

[0041] Figure 1 Image of the glass powder prepared in Example 1;

[0042] Figure 2 Microscopic morphology of the aluminum nitride ceramic joint prepared in Example 1;

[0043] Figure 3 The bar chart shows the bending strength of the aluminum nitride ceramic joint prepared in Example 1. Detailed Implementation

[0044] The present invention will be further illustrated by the following embodiments. It should be understood that the following embodiments are for illustrative purposes only and are not intended to limit the present invention.

[0045] In this disclosure, the chemical composition of the glass solder includes: 60-65 wt.% ZnO, 20-25 wt.% B₂O₃, 10-13 wt.% SiO₂, and 2-5 wt.% Al₂O₃. The coefficient of thermal expansion of the glass solder between 20-400℃ is (3.8-4.0) × 10⁻⁶. -6 K -1 The thermal expansion coefficients of the glass solder are highly compatible with those of aluminum nitride ceramics, and the solder also exhibits good chemical compatibility. However, if the Al2O3 content is too low, the thermal expansion coefficient of the resulting glass solder will increase significantly, leading to a mismatch between the thermal expansion coefficients of the glass solder and the aluminum nitride ceramic, resulting in a decrease in joint strength. If the Al2O3 content is too high, it will affect the electrical properties of the glass powder, leading to an increase in conductivity and affecting the insulation performance of aluminum nitride devices. Excessive or insufficient content of ZnO, SiO2, and B2O3 will all cause changes in the softening point of the glass solder, altering the welding process. Furthermore, this will lead to a mismatch in the thermal expansion coefficients of the glass solder and the aluminum nitride substrate, resulting in stress concentration at the joint and significantly reducing the strength of the aluminum nitride joint.

[0046] In this invention, the glass solder process is simple and suitable for industrial production, especially for soldering electrostatic chucks used in the semiconductor industry. The preparation method of the glass solder is illustrated below.

[0047] ZnO powder, H3BO3 powder, SiO2 powder, and Al2O3 powder are weighed and mixed according to a specific mass ratio to obtain a mixture. The mixing method includes wet ball milling, using alcohol as the mixing medium and alumina ceramic balls as the milling balls. The purity of ZnO powder, SiO2 powder, and Al2O3 powder is ≥99.0%, and the purity of H3BO3 powder is ≥99.5%. The average particle size of ZnO powder, H3BO3 powder, SiO2 powder, and Al2O3 powder is 5-10 μm. Preferably, after wet ball milling, the powder is dried and sieved; preferably, it is dried at 60°C for 2 hours, ground, and then sieved through an 80-mesh sieve.

[0048] The mixture was placed in a corundum crucible and then placed in a muffle furnace. The temperature was raised to the melting temperature at a certain rate and held at that temperature. The molten sample was then poured directly into deionized water for rapid cooling to obtain a block glass sample. The melting temperature was 1400-1500℃, the heating rate was 10℃ / min, and the holding time was 1-2h.

[0049] The block glass sample was crushed and pulverized using a planetary ball mill to obtain ZnO-B2O3-SiO2-Al2O3 glass solder powder. Specifically, the crushing and pulverizing parameters included: using deionized water as the grinding medium, alumina balls as the grinding balls, and mixing for 8 hours. Preferably, after crushing and pulverizing, the sample was dried and sieved. More preferably, it was dried at 100°C for 2 hours and sieved through a 200-mesh sieve.

[0050] The following exemplifies a method for joining silicon nitride ceramics.

[0051] Glass solder powder is mixed with a certain amount of binder to obtain glass slurry. Preferably, the organic carrier used in the glass slurry is a solution of ethyl cellulose in terpineol, wherein the mass ratio of ethyl cellulose to terpineol is 5:95. Moreover, the amount of organic carrier used is 20-25 wt.% of the mass of the glass solder.

[0052] A glass paste is uniformly coated onto the surface of an aluminum nitride ceramic at a certain thickness using screen printing, and then dried (preferably in an oven at 100°C for 30 minutes) to obtain a glass welding layer. Preferably, the surface of the silicon nitride ceramic is polished. The thickness of the glass paste coating on the aluminum nitride ceramic is in the range of 100-200 μm.

[0053] The aluminum nitride ceramics coated with a glass welding layer and the uncoated aluminum nitride ceramics are fixed by a fixture (such as an alumina fixture), and a certain counterweight pressure is applied. They are then placed in a muffle furnace for welding. After natural cooling in the furnace, the connection of the aluminum nitride ceramics is completed. The welding temperature is 700-800℃, and the holding time is 30-60 minutes.

[0054] In this invention, the prepared glass solder has a thermal expansion coefficient that is compatible with that of the aluminum nitride ceramic matrix and has good chemical compatibility, thereby realizing the connection of aluminum nitride ceramics. This effectively improves the connection strength and connection quality of aluminum nitride ceramics, and the process is stable and reliable, especially suitable for welding aluminum nitride electrostatic chucks used in the semiconductor industry.

[0055] In this invention, the aluminum nitride ceramic joint connected using this type of glass solder exhibits a three-point bending strength exceeding 190 MPa at room temperature and exceeding 160 MPa at a high temperature of 450°C. Furthermore, the helium leakage performance of the aluminum nitride ceramic joint is better than 5×10⁻⁶ MPa. -11 Pa·m 3 / S, resistivity of the weld interface is higher than 5×10 13 It has a strength of Ω·cm and exhibits good insulation properties.

[0056] The following examples further illustrate the present invention in detail. It should also be understood that the following examples are only for further explanation of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-essential improvements and adjustments made by those skilled in the art based on the above description of the present invention are within the scope of protection of the present invention. The specific process parameters, etc., in the following examples are merely examples within a suitable range; that is, those skilled in the art can make appropriate selections within the appropriate range based on the description herein, and are not intended to be limited to the specific values ​​in the examples below.

[0057] Example 1:

[0058] Step 1: Preparation of glass powder

[0059] a) Weigh and mix ZnO, H3BO3, SiO2, Al2O3, and other raw materials according to the mass ratios shown in the formula. The formula and proportions for the glass solder are shown in Table 1. The raw materials are mixed using a wet ball milling method. The solvent used for mixing is alcohol with a purity of 99.5%, added at 20-40% of the mixed powder. The milling media are alumina balls, with a raw material:milling ball ratio of 1:2. The above raw materials are sequentially added to a ball mill jar and milled at 300 r / min for 8 hours to obtain the mixed powder.

[0060] Table 1 lists the raw materials and proportions used in glass solder:

[0061]

[0062]

[0063] b) Dry the mixed powder in an oven at 60℃ for 2 hours, grind it, and then pass it through an 80-mesh sieve. Take a certain amount of glass raw material and place it in an alumina crucible and melt it at high temperature in a high-temperature lifting furnace. Heat the material to 1400℃ at a heating rate of 10℃ / min and hold it at that temperature for 2 hours. Then pour the molten sample directly into deionized water and cool it rapidly to obtain a block glass sample.

[0064] c) The block glass sample was crushed and powdered using a planetary ball mill with deionized water as the grinding medium and alumina as the grinding ball material. The sample, grinding ball and deionized water were added to the ball mill jar at a mass ratio of 1:2:1 and ball milled at 300 r / min for 8 h. After that, it was dried in an oven at 100 ℃ for 2 h and passed through a 200 mesh sieve to obtain ZnO-B2O3-SiO2-Al2O3 glass powder.

[0065] Step 2: Connecting aluminum nitride ceramics

[0066] d) Weigh ethyl cellulose and terpineol at a mass ratio of 5:95, put them into a sealed beaker, and stir at 90°C in a constant temperature magnetic stirrer until the ethyl cellulose is completely dissolved. Then cool to room temperature to obtain an organic carrier. Take a certain amount of glass powder obtained in step one, mix it evenly with the organic carrier to obtain a glass slurry. The amount of organic carrier is 20 wt.% of the glass powder.

[0067] e) The aluminum nitride ceramic surface to be welded is polished step by step using 500, 800, 1200 and 1600 grit wet sandpaper, and then cleaned with anhydrous ethanol. Glass paste is evenly coated onto the polished aluminum nitride ceramic surface using screen printing, with a coating thickness of 200 μm, and then dried in an oven at 100℃ for 30 min.

[0068] f) Using an alumina clamp, fix the coated aluminum nitride ceramic to the uncoated aluminum nitride ceramic sheet and apply a longitudinal pressure of 5 kPa. Place the sheet in a muffle furnace for welding. Increase the temperature from room temperature to 250°C at a rate of 5°C / min, then continue to increase the temperature to 450°C at a rate of 2°C / min, hold for 30 min, then continue to increase the temperature to 700°C at a rate of 2°C / min, hold for 30 min, and then allow it to cool naturally in the furnace to complete the connection of the aluminum nitride ceramic.

[0069] The glass solder obtained in Example 1 has a glass transition temperature of 560℃, a softening point of 610℃, and a coefficient of thermal expansion of 3.9 × 10⁻⁶ between 20-400℃. -6 K -1The coefficient of thermal expansion is close to that of aluminum nitride ceramics. Furthermore, the interface bonding effect is excellent after joining with glass solder. The resulting aluminum nitride ceramic joint exhibits a room temperature three-point bending strength of 202 MPa and a high-temperature three-point bending strength of 169 MPa at 450℃. The helium leakage rate of the resulting ceramic joint is 2.6 × 10⁻⁶. -11 Pa·m 3 / S, the welding interface resistance is 7.6×10 13 Ω·cm.

[0070] Example 2:

[0071] The difference between this embodiment 2 and embodiment 1 is that the glass solder component ratio is different, as shown in Table 2.

[0072] Table 2 lists the raw materials and proportions used in glass solder:

[0073]

[0074] The glass solder obtained in Example 2 has a glass transition temperature of 566℃, a softening point of 617℃, and a coefficient of thermal expansion of 3.8×10⁻⁶ between 20-400℃. -6 K -1 The coefficient of thermal expansion is close to that of aluminum nitride ceramics. Furthermore, the interfacial bonding effect after joining with glass solder is excellent. The resulting aluminum nitride ceramic joint exhibits a room temperature three-point bending strength of 199 MPa and a high-temperature three-point bending strength of 166 MPa at 450℃. The helium leakage rate of the resulting ceramic joint is 3.1 × 10⁻⁶. -11 Pa·m 3 / S, the weld interface resistance is 6.4×10 13 Ω·cm.

[0075] Example 3:

[0076] The difference between Example 3 and Example 1 is the different glass solder component ratio, as shown in Table 3. Everything else is the same as in Example 1.

[0077] Table 3 lists the raw materials and proportions used in glass solder:

[0078]

[0079] The glass solder obtained in Example 3 has a glass transition temperature of 570℃, a softening point of 620℃, and a coefficient of thermal expansion of 4.0×10⁻⁶ between 20-400℃. -6 K -1The coefficient of thermal expansion is close to that of aluminum nitride ceramics. Furthermore, the interfacial bonding effect after joining with glass solder is excellent. The resulting aluminum nitride ceramic joint exhibits a room temperature three-point bending strength of 198 MPa and a high-temperature three-point bending strength of 164 MPa at 450℃. The helium leakage rate of the resulting ceramic joint is 3.4 × 10⁻⁶. -11 Pa·m 3 / S, the weld interface resistance is 6.1×10 13 Ω·cm.

[0080] Example 4:

[0081] The difference between this embodiment and Embodiment 1 is that in step b), the melting process is as follows: the temperature is increased from room temperature to 1500°C at a rate of 10°C / min, held for 2 hours, and then naturally cooled in the furnace. Everything else is the same as in Embodiment 1.

[0082] The glass solder obtained in Example 4 has a glass transition temperature of 561℃, a softening point of 613℃, and a coefficient of thermal expansion of 4.0×10⁻⁶ between 20-400℃. -6 K -1 The coefficient of thermal expansion is close to that of aluminum nitride ceramics. Furthermore, the interfacial bonding effect after joining with glass solder is excellent. The resulting aluminum nitride ceramic joint exhibits a room temperature three-point bending strength of 193 MPa and a high-temperature three-point bending strength of 161 MPa at 450℃. The helium leakage rate of the resulting ceramic joint is 4.9 × 10⁻⁶. -11 Pa·m 3 / S, the welding interface resistance is 5.0×10 13 Ω·cm.

[0083] Example 5:

[0084] The difference between Example 5 and Example 1 is that in step b), the melting process is as follows: the temperature is increased from room temperature to 1400°C at a rate of 10°C / min, held for 1 hour, and then naturally cooled in the furnace. Everything else is the same as in Example 1.

[0085] The glass solder obtained in Example 5 has a glass transition temperature of 562℃, a softening point of 611℃, and a coefficient of thermal expansion of 3.9×10⁻⁶ between 20-400℃. -6 K -1 The coefficient of thermal expansion is close to that of aluminum nitride ceramics. Furthermore, the interface bonding effect is excellent after joining with glass solder. The resulting aluminum nitride ceramic joint exhibits a room temperature three-point bending strength of 191 MPa and a high-temperature three-point bending strength of 160 MPa at 450℃. The helium leakage rate of the resulting ceramic joint is 5.0 × 10⁻⁶. -11 Pa·m 3 / S, the welding interface resistance is 5.2×10 13 Ω·cm.

[0086] Example 6:

[0087] The difference between Example 6 and Example 1 is that the thickness of the screen-printed glass paste in step d) is 100 μm. Everything else is the same as in Example 1.

[0088] In Example 6, the interface bonding effect after joining with glass solder was good. The resulting aluminum nitride ceramic joint achieved a room temperature three-point bending strength of 196 MPa and a high-temperature three-point bending strength of 163 MPa at 450℃. The helium leakage rate of the ceramic joint was 4.3 × 10⁻⁶. -11 Pa·m 3 / S, the weld interface resistance is 6.4×10 13 Ω·cm.

[0089] Example 7:

[0090] The difference between Example 7 and Example 1 is that in step f), the welding process is as follows: the welding temperature is 800℃ and the welding time is 30 minutes. Everything else is the same as in Example 1.

[0091] In Example 7, the interface bonding effect after joining with glass solder was good. The resulting aluminum nitride ceramic joint achieved a room temperature three-point bending strength of 195 MPa and a high-temperature three-point bending strength of 163 MPa at 450℃. The helium leakage rate of the ceramic joint was 4.1 × 10⁻⁶. -11 Pa·m 3 / S, the weld interface resistance is 6.3×10 13 Ω·cm.

[0092] Example 8:

[0093] The difference between this embodiment 8 and embodiment 1 is that in step f), the welding process is as follows: the welding temperature is 700℃ and the welding time is 60min. The rest is the same as in embodiment 1.

[0094] In Example 8, the interface bonding effect after joining with glass solder was good. The resulting aluminum nitride ceramic joint achieved a room temperature three-point bending strength of 190 MPa and a high-temperature three-point bending strength of 160 MPa at 450℃. The helium leakage rate of the ceramic joint was 3.1 × 10⁻⁶. -11 Pa·m 3 / S, the welding interface resistance is 7.5×10 13 Ω·cm.

[0095] Example 9

[0096] The difference between Example 9 and Example 1 is that in step e), the coating thickness of the glass slurry is 50 μm. Everything else is the same as in Example 1.

[0097] Example 10

[0098] The difference between this embodiment 10 and embodiment 1 is that: in step e), the coating thickness of the glass slurry is 50 μm; and in step f), the welding process is: the welding temperature is 800℃ and the welding time is 30 min.

[0099] Example 11

[0100] The difference between this embodiment 11 and embodiment 1 is that: in step e), the coating thickness of the glass slurry is 50 μm; in step f), the welding process is: the welding temperature is 700℃ and the welding time is 60 min.

[0101] Example 12

[0102] The difference between Example 12 and Example 1 is that in step e), the coating thickness of the glass slurry is 300 μm. Everything else is the same as in Example 1.

[0103] Example 13

[0104] The difference between this embodiment 13 and embodiment 1 is that in step e), the coating thickness of the glass slurry is 300 μm, and in step f), the welding process is as follows: the welding temperature is 800℃ and the welding time is 30 min.

[0105] Example 14

[0106] The difference between this embodiment 14 and embodiment 1 is that in step e), the coating thickness of the glass slurry is 300 μm, and in step f), the welding process is as follows: the welding temperature is 700℃ and the welding time is 60 min.

[0107] Comparative Example 1

[0108] The difference between Comparative Example 1 and Example 1 is that in step a), ZnO, H3BO3, SiO2, and Al2O3 raw materials are weighed and mixed according to the mass ratio in Table 4.

[0109] Comparative Example 2

[0110] The difference between Comparative Example 2 and Example 1 is that in step a), ZnO, H3BO3, SiO2, and Al2O3 raw materials are weighed and mixed according to the mass ratio in Table 4.

[0111] Comparative Example 3

[0112] The difference between Comparative Example 3 and Example 1 is that in step a), ZnO, H3BO3, SiO2, and Al2O3 raw materials are weighed and mixed according to the mass ratio in Table 4.

[0113] Comparative Example 4

[0114] The difference between Comparative Example 4 and Example 1 is that in step a), ZnO, H3BO3, SiO2, and Al2O3 raw materials are weighed and mixed according to the mass ratio in Table 4.

[0115] Table 4 shows the composition, preparation parameters, and properties of the obtained glass solder:

[0116]

[0117] Table 5 shows the welding parameters and performance of the obtained aluminum nitride ceramic joints:

[0118]

[0119]

[0120] The above embodiments are possible implementations of the present invention, but the implementation of the present invention is not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and are included within the protection scope of the present invention.

Claims

1. A method for connecting aluminum nitride ceramic electrostatic chucks used in the semiconductor industry, characterized in that, include: (1) The glass solder and the organic solution are mixed to obtain a glass slurry; (2) The obtained glass paste is uniformly coated on the surface of the aluminum nitride ceramic electrostatic chuck by screen printing to obtain a glass paste layer and then dried to obtain an aluminum nitride ceramic electrostatic chuck with a glass solder layer on the surface. (3) Fix the aluminum nitride ceramic electrostatic chuck coated with glass solder layer and the uncoated aluminum nitride ceramic electrostatic chuck by clamping, then perform welding treatment, and let it cool naturally to room temperature with the furnace to form an aluminum nitride ceramic electrostatic chuck joint, thus completing the connection of aluminum nitride ceramic electrostatic chucks for the semiconductor industry. In step (1), the chemical composition of the glass solder includes: 60-65 wt.% ZnO, 20-25 wt.% B2O3, 10-13 wt.% SiO2 and 2-5 wt.% Al2O3, with the sum of the mass percentages of each component being 100 wt%. In step (3), the welding process is performed at a temperature of 700-800°C for 30-60 minutes.

2. The method according to claim 1, characterized in that, In step (1), the glass solder is in powder form with a particle size of 100nm to 75μm.

3. The method according to claim 1, characterized in that, In step (1), the glass transition temperature of the glass solder is 560-570℃ and the softening point is 610-620℃. The coefficient of thermal expansion of the glass solder between 20 and 400°C is (3.8–4.0) × 10⁻⁶. -6 K -1 Its thermal expansion coefficient matches that of the aluminum nitride ceramic electrostatic chuck.

4. The method according to claim 1, characterized in that, In step (1), the method for preparing the glass solder includes: (1) Weigh ZnO powder, H3BO3 powder, SiO2 powder and Al2O3 powder and mix them to obtain a mixture; (2) After placing the mixture in a crucible, put it into a muffle furnace, then heat it to the melting temperature and hold it thereto obtain a molten sample; (3) After the molten sample is directly poured into deionized water and rapidly cooled to obtain a block glass sample, it is then crushed and powdered to obtain the glass solder.

5. The method according to claim 4, characterized in that, The purity of the ZnO powder, SiO2 powder, and Al2O3 powder is ≥99.0%; the purity of the H3BO3 is ≥99.5%; and the average particle size of the ZnO powder, H3BO3 powder, SiO2 powder, and Al2O3 powder is 5-10 μm. The mixing method is wet ball milling; the parameters of the wet ball milling include: the mixing medium is alcohol, the grinding ball material is alumina ceramic balls, the rotation speed is 300-600 rpm, and the time is 8-10 hours. After wet ball milling, the material is dried, ground, and sieved; the drying temperature is 60°C and the drying time is 2 hours; the sieving is done through an 80-mesh sieve.

6. The method according to claim 4, characterized in that, The melting temperature is 1400–1500°C; the heating rate is 5–10°C / minute. The heat preservation treatment lasts for 1 to 2 hours.

7. The method according to claim 4, characterized in that, A planetary ball mill is used for crushing and grinding; the parameters of the planetary ball mill include: deionized water as the grinding medium, alumina balls as grinding balls, a rotation speed of 300-600 rpm, and a ball milling time of 6-10 h. After crushing and grinding, the powder is dried and sieved. The drying temperature is 100°C and the time is 2 hours. The sieving is done through a 200-mesh sieve.

8. The method according to claim 1, characterized in that, In step (1), the binder in the organic solution is at least one of ethyl cellulose, methyl cellulose, polyvinyl alcohol, and phenolic resin, and the solvent is selected from at least one of terpineol, triterpenol, ethyl acetate, and butyl acetate; the content of the binder in the organic solution is 5-10 wt%. The amount of the organic solution used is 20-25 wt. of the glass solder mass.

9. The method according to claim 1, characterized in that, In step (2), the drying temperature is 80-100°C and the time is 30-60 minutes; The thickness of the glass slurry layer is 50–300 μm.

10. The method according to claim 9, characterized in that, In step (2), the drying process involves placing the glass slurry layer in a 100°C oven for 30 minutes; the thickness of the glass slurry layer is 100–200 μm.

11. The method according to claim 1, characterized in that, In step (3), the glass solder layer formed by the glass solder layer after the furnace is naturally cooled to room temperature is in an amorphous state.

12. An aluminum nitride ceramic electrostatic chuck connector prepared according to claim 1, characterized in that, The aluminum nitride ceramic electrostatic chuck connector has a room temperature three-point bending strength ≥190MPa and a 450℃ high-temperature three-point bending strength ≥160MPa. The helium leakage rate of the aluminum nitride ceramic electrostatic chuck connector is <5×10⁻⁶. -11 Pa•m 3 / S、Weld interface resistivity >5×10 13 Ω•cm.

13. A glass welding sheet, characterized in that, Includes the glass solder and adhesive in step (1) of the method of claim 1; The adhesive is selected from at least one of ethyl cellulose, methyl cellulose, polyvinyl alcohol, and phenolic resin; The mass ratio of the adhesive to the glass solder is 1:(20-100). The thickness of the glass sheet is 50–300 μm.

14. The glass welding sheet according to claim 13, characterized in that, The thickness of the glass sheet is 100–200 μm.

15. The application of the glass welding sheet according to claim 13 in welding aluminum nitride ceramics, characterized in that, The aluminum nitride ceramic is an aluminum nitride electrostatic chuck used in the semiconductor industry.

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