A ceramic heater and its manufacturing method

Abstract

This invention discloses a ceramic heater, comprising a ceramic disc and a hollow ceramic shaft. The ceramic disc has a ceramic disc welding surface, and the hollow ceramic shaft has a hollow shaft welding surface corresponding to the ceramic disc welding surface. A pure aluminum metallization layer is formed on at least one of the welding surfaces of the ceramic disc and the hollow shaft. Welding hole protrusions are also formed on at least one of the welding surfaces of the ceramic disc and the hollow shaft. The ceramic disc and the hollow ceramic shaft are positioned relative to each other by a set of ceramic positioning elements. A vacuum-brazed pure aluminum weld layer is fused between the ceramic disc welding surface and the hollow shaft welding surface, forming a single integrated weld layer. The manufacturing method is also disclosed. This ceramic heater exhibits high cleanliness, is free of impurities, features a single integrated weld layer of the same material, good airtightness, and high connection strength. It is low-cost, requires no special pressurization structure, and has a short one-step process time; no post-weld processing is required.

Description

Technical Field

[0001] This invention relates to the field of ceramic heater technology, and more specifically to a ceramic heater and its manufacturing method. Background Technology

[0002] In semiconductor manufacturing equipment, ceramic heaters with heating functions are used to support wafers. Their function is to perform one or more of the following: heating the wafer, cooling the wafer, electrostatically adsorbing the wafer, vacuum adsorbing the wafer, and RF feed-in. Therefore, the requirements for ceramic heaters are particularly high. The ceramic heater structure consists of two parts: a ceramic disk with a wafer-supporting surface and a hollow shaft for connecting the ceramic disk and the semiconductor manufacturing equipment, both made of aluminum nitride. To ensure that no impurity elements are released from the solder layer under the process environment, the connection between the ceramic disk and the hollow shaft is generally achieved using thermostatic diffusion welding or ceramic solder brazing. The welded joint needs to guarantee airtightness and a certain connection strength.

[0003] The current welding methods for connecting ceramic discs and hollow shafts using thermostatic diffusion welding or ceramic solder brazing have the following problems:

[0004] 1. High cost: The temperature required for hot-press diffusion welding and ceramic solder brazing is generally above 1400℃, which usually requires a special pressure structure, resulting in high equipment cost.

[0005] 2. The process takes a long time; it usually takes more than 3 days to complete the entire welding process, which is time-consuming and results in low output.

[0006] 3. Post-processing is difficult. When performing hot-press diffusion welding or ceramic brazing, a margin needs to be left on the ceramic disc and hollow shaft. The margin is then removed after welding is completed, which makes the processing extremely difficult.

[0007] Therefore, to address the problems existing in the current technology, there is an urgent need to design a ceramic heater that can achieve good airtightness, high-strength connections, easy processing, high production volume, and low cost, while ensuring that no other impurity elements are introduced. This would meet the heating needs of semiconductor equipment. Summary of the Invention

[0008] The purpose of this invention is to address the problems of high cost, the need for special pressurization structures, high equipment costs, long processing time, low output, and the need for post-weld processing in existing ceramic heaters where the ceramic disc and hollow shaft are connected by welding. This invention provides a ceramic heater and its manufacturing method. This ceramic heater features high purity and is free of impurities, with an integral welded layer of the same material, good airtightness, and high connection strength. Its manufacturing method is low-cost, has a simple equipment structure, requires no special pressurization structures, operates at a process temperature below 1000℃, has high output, and a short complete process time. It eliminates the need for post-weld processing. More importantly, during the welding process, it uses aluminum, an element already present in the ceramic disc and hollow shaft, as the welding material, without introducing other metallic impurities. This meets the requirement of consistent, impurity-free ceramic heater material in semiconductor equipment, ensuring that the wafer quality is not contaminated during use.

[0009] The technical solution adopted by the present invention to achieve its first inventive objective is as follows: a ceramic heater, comprising a ceramic disc and a ceramic hollow shaft, wherein the ceramic disc is provided with a ceramic disc welding surface, and the ceramic hollow shaft is provided with a hollow shaft welding surface corresponding to the ceramic disc welding surface; a pure aluminum metallization layer is provided on at least one of the welding surfaces of the ceramic disc welding surface and the hollow shaft welding surface; welding hole protrusions are provided on at least one of the welding surfaces of the ceramic disc welding surface and the hollow shaft welding surface; the ceramic disc and the ceramic hollow shaft are positioned to each other by a set of ceramic positioning elements; a vacuum brazed pure aluminum welding layer is fused between the ceramic disc welding surface and the hollow shaft welding surface; the vacuum brazed pure aluminum welding layer and the pure aluminum metallization layer are vacuum brazed and fused together to form an integral welding layer. This ceramic heater features pre-formed welding surfaces on the ceramic disc and hollow ceramic shaft, with a pure aluminum metallization layer applied to either the welding surface of the ceramic disc or the welding surface of the hollow ceramic shaft. Since the ceramic disc and hollow ceramic shaft are made of aluminum nitride, to prevent the introduction of impurities other than nitrogen and aluminum during the manufacturing process, the welding surfaces of the ceramic disc and / or the hollow ceramic shaft are vacuum-plated with aluminum to form a pure aluminum metallization layer. This pure aluminum metallization layer contains aluminum, the same element as the ceramic disc and hollow ceramic shaft, and is also made of the same material as the brazing material. This ensures good welding and fusion, while preventing the introduction of impurities of different materials, thus guaranteeing the high cleanliness requirements of the semiconductor industry during the use of the ceramic heater. Simultaneously, welding hole protrusions are provided on the welding surface of the ceramic disc and / or the welding surface of the ceramic hollow shaft. The purpose is to provide sufficient space for the solder to melt and fill during vacuum brazing. When brazing in a vacuum brazing furnace, due to the internal vacuum, the pure aluminum metallization layer and the solder melt and fuse together, filling the welding holes formed by the welding hole protrusions. This ensures the welding holes are completely filled with solder, connecting the ceramic disc and the ceramic hollow shaft welding surfaces into a single unit. An integral weld layer of the same material as the ceramic disc and the ceramic hollow shaft is formed between them, creating a unified structure that ensures both airtightness during welding and connection strength between the weld surfaces. During vacuum brazing (brazing temperature 760℃~860℃), the welding hole protrusions and ceramic positioning components are encased within the vacuum brazing pure aluminum weld layer, increasing the connection strength between the ceramic disc and the ceramic hollow shaft while ensuring the welding quality.This ceramic heater is manufactured in one piece through vacuum brazing, requiring no special pressurization structure. The process temperature is below 1000℃, resulting in high output and a short complete process time. It eliminates the need for post-welding processing, leading to low cost and high-quality ceramic heaters that meet the semiconductor industry's requirements for a highly pollution-free environment.

[0010] Preferably, the welded perforation protrusions and ceramic positioning components are encased within a vacuum-brazed pure aluminum weld layer, forming an integral structure with the ceramic disc and the ceramic hollow shaft. This structure increases the strength of the connection between the ceramic disc and the ceramic hollow shaft, ensures the positioning accuracy of the ceramic disc and the ceramic hollow shaft, and also increases the airtightness of the connection.

[0011] Preferably, the welding surface on the ceramic disc is arranged in a ring shape corresponding to the welding surface on the ceramic hollow shaft. The welding surface is arranged in a ring shape to match the end face structure of the ceramic hollow shaft, which facilitates welding connection and also saves materials.

[0012] Preferably, the pure aluminum metallization layer is formed by vacuum depositing pure aluminum using physical vapor deposition (PDV), and the thickness of the pure aluminum metallization layer is greater than 2 micrometers. The metallization layer formed by vacuum depositing pure aluminum using PDV ensures that it fuses with the solder to form an integrated structure during subsequent vacuum brazing, resulting in good airtightness and high connection strength.

[0013] Preferably, the welding hole protrusion is a plurality of independent protrusions, which are evenly distributed circumferentially along the welding surface, and the height of the welding hole protrusion is 0.03mm to 0.1mm and the diameter is less than 2mm.

[0014] Preferably, the welding aperture protrusion is an annular protrusion, integrally formed in a ring around the center of the welding surface. The welding aperture protrusion has several flow channels spaced apart on it. The height of the welding aperture protrusion is 0.03mm to 0.1mm, and the thickness of the annular surface is less than 2mm. Alternatively, the welding aperture protrusion can be an annular protrusion integrally formed with the welding surface, with several flow channels spaced apart on it. This allows the solder to fuse together as a whole through the flow channels during vacuum brazing, improving the connection strength and airtightness of the weld surface.

[0015] Preferably, positioning holes are provided on the welding surfaces of the ceramic disc and the ceramic hollow shaft, respectively. The diameter of the positioning holes is less than 2 mm and the depth is greater than 2 mm. Ceramic positioning elements are inserted into the positioning holes and are designed to mate with them. The ceramic positioning elements are made of the same material as the ceramic disc. To ensure the accuracy of the connection position during the brazing process of the ceramic disc and the ceramic hollow shaft in the vacuum brazing furnace, positioning is achieved through the positioning holes and the ceramic positioning elements inserted inside them. The ceramic positioning pins, made of the same material as the ceramic disc and the ceramic hollow shaft, are chosen to ensure that all connecting parts are of the same material, thus meeting the requirement of not introducing other metallic impurities.

[0016] The technical solution adopted by this invention to achieve its second objective is: a method for manufacturing a ceramic heater, comprising the following steps:

[0017] Step 1: Machining welding hole protrusions on the welding surface of the ceramic disc and / or the welding surface of the ceramic hollow shaft;

[0018] Step 2: Perform precision machining on the ceramic disc and hollow ceramic shaft without leaving any allowance;

[0019] Step 3: Drill positioning holes on the welding surface of the ceramic disc and the welding surface of the ceramic hollow shaft respectively;

[0020] Step 4: Machin the ceramic positioning part according to the size of the positioning hole;

[0021] Step 5: Metallize the welding surface of the ceramic disc and / or the welding surface of the ceramic hollow shaft by vacuum depositing pure aluminum through physical vapor deposition to form a pure aluminum metallization layer. The aluminum thickness of the metallization layer is greater than 2 micrometers, and the shape of the pure aluminum metallization layer is the same as the shape of the welding surface.

[0022] Step 6: Prefabricate pure aluminum welding sheets: Fabricate pure aluminum welding sheets with the same shape as the welding surface, and the thickness of the pure aluminum welding sheets is greater than 0.01mm; and drill welding sheet positioning holes on the pure aluminum welding sheets to match the ceramic positioning parts;

[0023] Step 7: Assembly of the ceramic heater: Insert one end of the ceramic positioning component into the ceramic disk positioning hole on the ceramic disk welding surface, then fit the welding plate positioning hole on the pure aluminum welding plate onto the ceramic positioning component, and finally insert the ceramic hollow shaft positioning hole on the hollow shaft welding surface into the other end of the ceramic positioning component to complete the assembly of the ceramic heater.

[0024] Step 8: Place the assembled ceramic heater into a vacuum brazing furnace for brazing; brazing temperature 760℃~860℃, holding time 5min~10min; after brazing, the connected ceramic heater product is obtained. The manufacturing method of this ceramic heater allows for direct precision machining of the ceramic disc, hollow ceramic shaft, ceramic locating pin, and pure aluminum welding sheet, eliminating the need for machining allowances and post-welding processing. This results in a short and convenient manufacturing time. Because the ceramic disc and hollow ceramic shaft are machined separately, the processing equipment has a simple structure and high machining precision. Subsequent welding utilizes a vacuum furnace for vacuum brazing at temperatures of 760℃~860℃, with the process temperature below 1000℃. No special pressure structure is required, leading to low equipment costs. The entire process of manufacturing the ceramic heater takes no more than 12 hours, demonstrating high efficiency. More importantly, the use of pure aluminum for both the metallization layer and the welding sheet ensures that no other metallic impurities are introduced during the welding process, meeting the requirement of consistent, impurity-free materials in semiconductor equipment and preventing wafer contamination during use.

[0025] Preferably, in step 4, the ceramic positioning component is a ceramic positioning pin, and the length of the ceramic positioning component is twice the depth of the positioning hole in the ceramic disc; in step 6, the pre-forming processing of the pure aluminum welding sheet is carried out by punching or laser cutting. The ceramic positioning pin is used to connect the ceramic disc and the ceramic hollow shaft, therefore, its length must be at least equal to twice the depth of the positioning hole in the ceramic disc.

[0026] Preferably, in step 7, the pure aluminum welding sheet forms a gap filled by molten solder between itself and the welding hole protrusion during the assembly process.

[0027] Preferably, in step 8, the pure aluminum metallization layer and the pure aluminum welding sheet are simultaneously melted in the vacuum brazing furnace and then fused together to fill the gaps in the solder molten filling process, thereby forming an integral weld layer between the ceramic disk welding surface and the ceramic hollow shaft welding surface. In step 7, by setting welding hole protrusions, the pure aluminum welding sheet forms a solder molten filling gap with it during the assembly process. In the vacuum brazing process in the vacuum brazing furnace, due to the internal vacuum, the inside of the solder molten filling gap is also in a vacuum state. During the melting of the pure aluminum metallization layer and the pure aluminum welding sheet, the solder flows into the solder molten filling gap and fills it, so that the ceramic disk welding surface and the ceramic hollow shaft welding surface are connected to each other as one, forming an integral welded connection layer with good airtightness and high connection strength.

[0028] The beneficial effects of this invention are: the ceramic heater has high purity and is free of impurity elements, has an integral welded layer of the same material, good airtightness, and high connection strength.

[0029] The manufacturing method of this ceramic heater allows for direct precision machining of components such as the ceramic disc and hollow ceramic shaft, eliminating the need for machining allowances and post-welding processing. This results in a short and convenient manufacturing time. Subsequent welding utilizes a vacuum furnace for vacuum brazing at temperatures of 760℃~860℃, with process temperatures below 1000℃. No special pressure structures are required, leading to low equipment costs. The entire process of manufacturing the ceramic heater takes no more than 12 hours, demonstrating high efficiency. The use of pure aluminum for both the metallization layer and the solder pads ensures that no additional metallic impurities are introduced during welding, meeting the requirement for consistent, impurity-free materials in semiconductor equipment and guaranteeing no contamination of wafer quality during use. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of a structure of the ceramic heater of the present invention;

[0031] Figure 2 yes Figure 1 Enlarged view of point A in the middle;

[0032] Figure 3 This is a schematic diagram of one structure of the ceramic disc in this invention;

[0033] Figure 4 This is a schematic diagram of a structure of the ceramic hollow shaft in this invention;

[0034] Figure 5 This is a schematic diagram of a structure of the pure aluminum welding sheet of the present invention;

[0035] Figure 6 This is a schematic diagram of an assembly structure of the ceramic heater of the present invention;

[0036] Figure 7 yes Figure 6 Enlarged view at point B in the middle;

[0037] Figure 8 yes Figure 6 A magnified view of section B, showing a schematic diagram of a structure after vacuum brazing.

[0038] Figure 9 This is a schematic diagram of a ceramic disc in Embodiment 2 of the present invention;

[0039] Figure 10 This is a partial structural schematic diagram of the ceramic heater assembly in Embodiment 2 of the present invention;

[0040] Figure 11 This is a partial structural diagram of the ceramic heater after vacuum brazing in Embodiment 2 of the present invention;

[0041] In the figure: 1. Ceramic disc, 11. Welding surface of ceramic disc, 12. Positioning hole of ceramic disc, 2. Hollow ceramic shaft, 21. Welding surface of hollow shaft, 22. Positioning hole of hollow ceramic shaft, 3. Pure aluminum metallization layer, 4. Welding hole protrusion, 5. Ceramic positioning component, 6. Vacuum brazed pure aluminum weld layer, 7. Pure aluminum weld sheet, 71. Positioning hole of weld sheet, 8. Filling gap with molten solder, 9. Integrated weld layer. Detailed Implementation

[0042] The present invention will now be described in detail with reference to specific embodiments and accompanying drawings.

[0043] Example 1:

[0044] exist Figure 1 , Figure 2 In the illustrated embodiment, a ceramic heater includes a ceramic disc 1 and a hollow ceramic shaft 2. The ceramic disc 1 has a ceramic disc welding surface 11, and the hollow ceramic shaft 2 has a hollow shaft welding surface 21 corresponding to the ceramic disc welding surface 11. A pure aluminum metallization layer 3 is disposed on at least one of the welding surfaces of the ceramic disc welding surface 11 and the hollow shaft welding surface 21. Welding hole protrusions 4 are disposed on at least one of the welding surfaces of the ceramic disc welding surface 11 and the hollow shaft welding surface 21. The ceramic disc 1 and the hollow ceramic shaft 2 are positioned to each other by a set of ceramic positioning elements 5. A vacuum brazed pure aluminum weld layer 6 is fused between the ceramic disc welding surface 11 and the hollow ceramic shaft welding surface. The vacuum brazed pure aluminum weld layer 6 and the pure aluminum metallization layer 3 are vacuum brazed and fused together to form an integral weld layer 9. The welding hole protrusions 4 and the ceramic positioning elements 5 are enclosed within the vacuum brazed pure aluminum weld layer 6 and form an integral structure with the ceramic disc 1 and the hollow ceramic shaft 2.

[0045] The ceramic disc welding surface 11 and the ceramic hollow shaft welding surface 21 are arranged in a ring shape.

[0046] The pure aluminum metallization layer 3 is a metallization layer formed by vacuum deposition of pure aluminum through physical vapor deposition, and the thickness of the pure aluminum metallization layer is greater than 2 micrometers. In this embodiment, the thickness of the pure aluminum metallization layer is 3 micrometers.

[0047] In this embodiment, the welding hole protrusion 4 consists of several independent protrusions, which are evenly distributed circumferentially along the welding surface. The height of the welding hole protrusion is 0.03mm to 0.1mm, and the diameter is less than 2mm.

[0048] The ceramic disc welding surface 11 and the ceramic hollow shaft welding surface 21 are respectively provided with positioning holes. The positioning holes include ceramic disc positioning holes 12 and ceramic hollow shaft positioning holes 22 provided on the ceramic disc welding surface. The diameter of the ceramic disc positioning holes 12 and the ceramic hollow shaft positioning holes 22 is less than 2 mm and the depth is greater than 2 mm. The ceramic positioning component 5 is inserted into the ceramic disc positioning holes 12 and the ceramic hollow shaft positioning holes 22. The ceramic positioning component 5 is configured to cooperate with the ceramic disc positioning holes 12 and the ceramic hollow shaft positioning holes 22. The ceramic positioning component 5 is a ceramic positioning pin made of the same material as the ceramic disc.

[0049] In this embodiment, the ceramic heater, ceramic disc 1, and ceramic hollow shaft 2 are all made of aluminum nitride ceramic material. The ceramic disc 1 has a diameter of 300 mm and a thickness of 20 mm. The ceramic hollow shaft has an outer diameter of 80 mm, an inner diameter of 60 mm, and a height of 200 mm.

[0050] The method for manufacturing this ceramic heater includes the following steps:

[0051] Step 1: As Figure 3 , Figure 4 As shown, the ceramic disc 1 and the hollow ceramic shaft 2 are rough machined, and the ceramic disc welding surface 11 and the hollow ceramic shaft welding surface 21 are machined on them respectively. Welding hole protrusions 4 are machined on the ceramic disc welding surface 11 by mechanical processing. The number of protrusions is equal to 6, and they are centrally symmetrically distributed. The height of the welding hole protrusions 4 is 0.05mm, and the diameter of the welding hole protrusions is 1.5mm.

[0052] Step 2: Precision machine the ceramic disc 1 to a diameter of 300mm and a thickness of 20mm. Precision machine the ceramic hollow shaft 2 to the required dimensions of an outer diameter of 80mm, an inner diameter of 60mm, and a height of 200mm. No allowance is left during the machining process.

[0053] Step 3: Drill ceramic disc positioning holes 12 on the ceramic disc welding surface 11. The ceramic disc positioning holes 12 have a diameter of 1.5mm and a depth of 3mm; drill ceramic hollow shaft positioning holes 22 on the ceramic hollow shaft welding surface 21. The ceramic hollow shaft positioning holes 22 have a diameter of 1.5mm and a depth of 3mm.

[0054] Step 4: Machining ceramic positioning pins according to the dimensions of the positioning holes in the ceramic disc. The diameter of the ceramic positioning pins is the same as that of the positioning holes 12 in the ceramic disc, and the length is twice the depth of the positioning holes 12 in the ceramic disc; that is, the diameter of the ceramic positioning pins is 1.5 mm and the length is 6 mm.

[0055] Step 5: Metallize the ceramic disk welding surface 11. Specifically, PVD plate pure aluminum on the ceramic disk welding surface to form a pure aluminum metallization layer 3. The aluminum thickness of the pure aluminum metallization layer 3 is 3 micrometers, and the shape of the pure aluminum metallization layer 3 is the same as that of the hollow shaft welding surface.

[0056] Step 6: As Figure 5 As shown, the prefabricated pure aluminum welding sheet 7 is made of pure aluminum and has a thickness of 0.02mm. The shape needs to be processed to be the same as the welding surface, and the welding sheet positioning hole 71 is punched out. The welding sheet pre-forming processing method can be punching or laser cutting.

[0057] Step 7: Assembly of the ceramic heater: as follows Figure 6 As shown, one end of the ceramic positioning piece 5 is inserted into the ceramic disc positioning hole 12 on the ceramic disc welding surface, then the welding plate positioning hole 71 on the pure aluminum welding plate 7 is fitted onto the ceramic positioning piece 5, and finally the ceramic hollow shaft positioning hole 22 on the hollow shaft welding surface is inserted into the other end of the ceramic positioning piece 5 to complete the assembly of the ceramic heater.

[0058] like Figure 7 As shown, during the assembly process, the pure aluminum welding sheet 7 forms a weld molten filling gap 8 between itself and the welding hole protrusion 4. Figure 8 As shown, the pure aluminum metallization layer 3 and the pure aluminum welding sheet 7 melt simultaneously in the vacuum brazing furnace and then fuse together to fill the gap 8 filled by the molten solder, thereby forming an integral welding layer 9 between the ceramic disk welding surface 11 and the ceramic hollow shaft welding surface 12.

[0059] Step 8: Place the assembled heater into a vacuum brazing furnace for vacuum brazing; brazing temperature 760℃, holding time 5min; after brazing, the connected ceramic heater product is obtained.

[0060] Example 2:

[0061] exist Figure 10 , Figure 11 The technical solution in the illustrated embodiment is basically the same as that in Embodiment 1, except that:

[0062] The ceramic heater, ceramic disc 1, and ceramic hollow shaft 2 are all made of aluminum nitride ceramic material. Ceramic disc 1 has a diameter of 400mm and a thickness of 30mm. Ceramic hollow shaft has an outer diameter of 100mm, an inner diameter of 80mm, and a height of 300mm.

[0063] like Figure 9As shown, the welding hole protrusion 4 is an annular protrusion. The welding hole protrusion 4 is integrally arranged in an annular shape with the center of the welding surface as the center. A plurality of flow channels 41 are provided on the welding hole protrusion 4 at intervals. The height of the welding hole protrusion 41 is 0.03mm to 0.1mm, and the thickness of the protrusion annular surface is less than 2mm.

[0064] The method for manufacturing this ceramic heater includes the following steps:

[0065] Step 1: Roughly machine the ceramic disc 1 and the hollow ceramic shaft 2, and machine the ceramic disc welding surface 11 and the hollow ceramic shaft welding surface 21 on them respectively. Welding hole protrusions 4 are machined on the ceramic disc welding surface 11 and the hollow ceramic shaft welding surface 21 respectively. The welding hole protrusions 4 are integrally arranged in a ring shape with the center of the welding surface as the center. Several flow channels 41 are spaced apart on the welding hole protrusions 4. The height of the welding hole protrusions 4 is 0.1mm, and the thickness of the ring surface of the welding hole protrusions is 1mm. The welding hole protrusions 4 on the ceramic disc and the welding hole protrusions 4 on the hollow ceramic shaft are machined at two different positions, forming an inner and outer ring misalignment structure during assembly.

[0066] Step 2: Precision machine the ceramic disc 1 to a diameter of 400mm and a thickness of 30mm. Precision machine the ceramic hollow shaft 2 to the required dimensions of an outer diameter of 100mm, an inner diameter of 80mm, and a height of 300mm. No allowance is left during the machining process.

[0067] Step 3: Drill ceramic disc positioning holes 12 on the ceramic disc welding surface 11. The ceramic disc positioning holes 12 have a diameter of 1.5mm and a depth of 3mm; drill ceramic hollow shaft positioning holes 22 on the ceramic hollow shaft welding surface 21. The ceramic hollow shaft positioning holes 22 have a diameter of 1.5mm and a depth of 3mm.

[0068] Step 4: Machining ceramic positioning pins according to the dimensions of the positioning holes in the ceramic disc. The diameter of the ceramic positioning pins is the same as that of the positioning holes 12 in the ceramic disc, and the length is twice the depth of the positioning holes 12 in the ceramic disc; that is, the diameter of the ceramic positioning pins is 1.5 mm and the length is 6 mm.

[0069] Step 5: Metallize the ceramic disk welding surface 11 and the ceramic hollow shaft welding surface respectively. Specifically, pure aluminum is PVD plated on the ceramic disk welding surface to form a pure aluminum metallization layer 3. The aluminum thickness of the pure aluminum metallization layer 3 is 2.5 micrometers, and the shape of the pure aluminum metallization layer 3 is the same as that of the hollow shaft welding surface.

[0070] Step 6: Prefabricate pure aluminum welding sheet 7: The pure aluminum welding sheet 7 is made of pure aluminum and has a thickness of 0.03mm; its shape needs to be processed to be the same as the welding surface, and welding sheet positioning holes 71 are punched out; the welding sheet pre-forming processing method can be punching or laser cutting.

[0071] Step 7: Assembly of the ceramic heater: as follows Figure 10 As shown, one end of the ceramic positioning piece 5 is inserted into the ceramic disc positioning hole 12 on the ceramic disc welding surface, then the welding plate positioning hole 71 on the pure aluminum welding plate 7 is fitted onto the ceramic positioning piece 5, and finally the ceramic hollow shaft positioning hole 22 on the hollow shaft welding surface is inserted into the other end of the ceramic positioning piece 5 to complete the assembly of the ceramic heater.

[0072] During assembly, the pure aluminum welding sheet 7 forms a weld filler gap 8 between itself and the welding hole protrusion 4. For example... Figure 11 As shown, the pure aluminum metallization layer 3 and the pure aluminum welding sheet 7 melt simultaneously in the vacuum brazing furnace and then fuse together to fill the gap 8 filled by the molten solder, thereby forming an integral welding layer 9 between the ceramic disk welding surface 11 and the ceramic hollow shaft welding surface 12.

[0073] Step 8: Place the assembled heater into a vacuum brazing furnace for vacuum brazing; brazing temperature 860℃, holding time 10min; after brazing, the connected ceramic heater product is obtained.

[0074] The technical solutions in the above embodiments effectively solve the problems of existing ceramic heaters, such as: "the welding method used for ceramic discs and hollow shafts is costly; the temperature required for hot-press diffusion welding and ceramic brazing is generally above 1400℃, which usually requires a special pressure structure, resulting in high equipment costs; the process time is long, usually more than 3 days, resulting in low output; and the post-processing is difficult, as hot-press diffusion welding or ceramic brazing requires leaving a margin on the ceramic disc and hollow shaft, which is then removed after welding, making this process extremely difficult." This ceramic heater and its manufacturing method allow for direct precision machining of components such as the ceramic disc and hollow ceramic shaft, eliminating the need for machining allowances and post-welding processing. The manufacturing process is quick and convenient, with subsequent welding performed in a vacuum furnace at temperatures ranging from 760℃ to 860℃. The process temperature remains below 1000℃, requiring no special pressure structures and resulting in low equipment costs. The entire manufacturing process for the ceramic heater takes no more than 12 hours, demonstrating high efficiency. The metallization layer and solder pads are made of pure aluminum, ensuring that no impurities other than nitrogen and aluminum are introduced during welding. This meets the requirement of consistent, impurity-free materials in semiconductor equipment, guaranteeing no contamination of wafer quality during use.

[0075] It should be noted that the embodiments described above are merely illustrative of the principles of the present invention. Various changes and modifications can be made to the present invention without departing from its scope, and all such changes and modifications fall within the scope of the claimed invention. Based on the embodiments described in this invention, all other embodiments obtained by those skilled in the art without inventive effort and based on the technical solutions of this application should fall within the scope of protection of this invention.

Claims

1. A method for manufacturing a ceramic heater, characterized in that... Includes the following steps: Step 1: Machining welding hole protrusions (4) on the ceramic disc welding surface (11) and / or the ceramic hollow shaft welding surface (21); Step 2: Perform precision machining on the ceramic disc (1) and the hollow ceramic shaft (2) without leaving any allowance; Step 3: Drill positioning holes on the ceramic disc welding surface (11) and the ceramic hollow shaft welding surface (2) respectively; Step 4: Machining the ceramic positioning part (5) according to the size of the positioning hole; Step 5: Metallize the ceramic disk welding surface (11) and / or the ceramic hollow shaft welding surface (21) by vacuum depositing pure aluminum to form a pure aluminum metallization layer (3) through physical vapor deposition. The aluminum thickness of the metallization layer is greater than 2 micrometers, and the shape of the pure aluminum metallization layer (3) is the same as the shape of the welding surface. Step 6: Prefabricate pure aluminum welding sheet: Prepare a pure aluminum welding sheet (7) with the same shape as the welding surface. The thickness of the pure aluminum welding sheet (7) is greater than 0.01 mm. Make welding sheet positioning holes (71) on the pure aluminum welding sheet (7) to match the ceramic positioning parts. Step 7: Assembly of ceramic heater: Insert one end of ceramic positioning part (5) into the ceramic disk positioning hole (12) on the ceramic disk welding surface, then put the welding plate positioning hole (71) on the pure aluminum welding plate (7) onto the ceramic positioning part (5), and finally insert the ceramic hollow shaft positioning hole (22) on the hollow shaft welding surface into the other end of the ceramic positioning part (5) to complete the assembly of ceramic heater; Step 8: Place the assembled ceramic heater into a vacuum brazing furnace for brazing; brazing temperature 760℃~860℃, holding time 5min~10min; after brazing, the connected ceramic heater product is obtained.

2. The method for manufacturing a ceramic heater according to claim 1, characterized in that: In step 4, the ceramic positioning part (5) is a ceramic positioning pin, and the length of the ceramic positioning part is twice the depth of the positioning hole of the ceramic disc; in step 6, the pure aluminum welding sheet (7) is pre-formed by punching or laser cutting.

3. The method for manufacturing a ceramic heater according to claim 1, characterized in that: In step 7, the pure aluminum welding sheet (7) forms a weld molten filling gap (8) between itself and the welding hole protrusion (4) during the assembly process.

4. The method for manufacturing a ceramic heater according to claim 3, characterized in that: In step 8, the pure aluminum metallization layer (3) and the pure aluminum welding sheet (7) are melted simultaneously in the vacuum brazing furnace and then fused together and filled into the gap (8) filled by the molten solder, thereby forming an integral welding layer (9) between the ceramic disk welding surface (11) and the ceramic hollow shaft welding surface (12).

5. The method for manufacturing a ceramic heater according to any one of claims 1 to 4, characterized in that: The ceramic heater includes a ceramic disc (1) and a hollow ceramic shaft (2). The ceramic disc (1) has a ceramic disc welding surface (11), and the hollow ceramic shaft (2) has a hollow shaft welding surface (21) corresponding to the ceramic disc welding surface (11). A pure aluminum metallization layer (3) is provided on at least one of the welding surfaces of the ceramic disc welding surface (11) and the hollow ceramic shaft welding surface (21). Welding hole protrusions (4) are provided on at least one of the welding surfaces of the ceramic disc welding surface (11) and the hollow ceramic shaft welding surface (21). (4) During assembly, an inner and outer ring misalignment structure is formed; the ceramic disk (1) and the ceramic hollow shaft (2) are positioned to each other by a set of ceramic positioning parts (5), and a vacuum brazed pure aluminum welding layer (6) is fused between the welding surface (11) of the ceramic disk and the welding surface (21) of the ceramic hollow shaft. The vacuum brazed pure aluminum welding layer (6) and the pure aluminum metallization layer (3) are vacuum brazed and fused together to form an integral welding layer (9); the welding hole protrusion (4) is an annular protrusion. The welding hole protrusion (4) is annularly and integrally set with the center of the welding surface as the center. Several flow channels (41) are spaced on the welding hole protrusion (4).

6. The method for manufacturing a ceramic heater according to claim 5, characterized in that: The welding hole protrusion (4) and ceramic positioning component (5) are encased in a vacuum brazed pure aluminum weld layer (6) to form an integral structure with the ceramic disk (1) and ceramic hollow shaft (2).

7. A method for manufacturing a ceramic heater according to claim 5, characterized in that: The pure aluminum metallization layer (3) is a metallization layer formed by vacuum deposition of pure aluminum through physical vapor deposition, and the thickness of the pure aluminum metallization layer (3) is greater than 2 micrometers.

8. A method for manufacturing a ceramic heater according to claim 5, characterized in that: The welding hole protrusion (4) consists of several independent protrusions. The welding hole protrusion (4) is evenly distributed along the circumference of the welding surface. The height of the welding hole protrusion (4) is 0.03mm to 0.1mm and the diameter is less than 2mm.

9. A method for manufacturing a ceramic heater according to claim 5, characterized in that: The height of the welding hole protrusion (4) is 0.03mm to 0.1mm, and the thickness of the protrusion ring surface is less than 2mm.

10. A method for manufacturing a ceramic heater according to claim 5, characterized in that: Positioning holes are provided on the ceramic disc welding surface (11) and the ceramic hollow shaft welding surface (21). The diameter of the positioning hole is less than 2 mm and the depth is greater than 2 mm. The ceramic positioning component is inserted into the positioning hole and is configured to cooperate with the positioning hole. The ceramic positioning component is made of ceramic positioning pin of the same material as the ceramic disc.

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