Quartz base and method for manufacturing the same

Abstract

The application discloses a quartz base, which comprises a lower base for connecting a furnace bottom plate, an upper base arranged above the lower base in parallel with the lower base for connecting a quartz boat, an integrated groove rod connected perpendicularly with the lower base and the upper base for supporting and positioning a quartz sheet, an upper end of the integrated groove rod extending upward through the upper base into an integrated long positioning column, and a lower end of the integrated groove rod extending downward through the lower base into an integrated short positioning column; a plurality of groove teeth are uniformly distributed on the integrated groove rod arranged between the upper base and the lower base; independent long positioning columns and independent short positioning columns are fixed on the upper base and the lower base in a uniform manner and are arranged uniformly with the integrated short positioning column. The application further discloses a manufacturing method of the quartz base. The quartz base and the manufacturing method thereof do not need to repeatedly build a false joint fixture and repeatedly adjust and calibrate, avoid manual operation errors, reduce manufacturing difficulty, and can effectively improve the stability of product quality, production capacity and production efficiency.

Description

Technical Field

[0001] This invention relates to the field of semiconductor equipment technology, and more specifically to a quartz base and its manufacturing method. Background Technology

[0002] Currently, there is a shortage of chips, especially high-end chips, due to the low yield rate of silicon wafer manufacturing processes and the low production efficiency of high-end chips. This is mainly because the oxidation and diffusion processes of silicon wafers, as well as the equipment used, do not meet the required standards. The oxidation and diffusion processes of silicon wafers have very high environmental requirements, especially regarding the purity of the equipment and the air. Quartz substrates are such equipment; their material is quartz, which is difficult to process. The processing flow is long, and the processing mainly relies on grinding and heat treatment. If the air purification or cleaning is inadequate, or if the fixture design is improper, it can introduce metal cation contamination into the silicon wafers, significantly reducing the chip yield rate.

[0003] The existing quartz base mainly consists of a small flange, a large flange, a long positioning post on the small flange, a short positioning post below the large flange, and a grooved bar between the two flanges, all connected as one piece. Both the large and small flanges have a center hole, and there are three grooved bars with groove teeth. There are four long positioning posts and four short positioning posts.

[0004] The quartz base connects to the quartz boat above and the furnace bottom plate below, serving as a connector, support, and positioner. During operation, opaque quartz plates are inserted into the grooves for silicon wafer oxidation and diffusion, while also providing insulation and regulating furnace airflow. To improve the yield of silicon wafers during oxidation and diffusion and reduce contamination from the quartz base, high purity of the quartz base material and a suitable processing environment are required. Generally, high-purity quartz is used and processing takes place in a cleanroom to avoid dust and metal cation contamination.

[0005] To meet market demand and improve silicon wafer production efficiency, the number of silicon wafers inserted into the quartz boat has increased from one at a time to five at a time, and now to twenty-five at a time. This places higher demands on the shape and positional accuracy of the quartz base. The flatness of the bottom surface of the short positioning post must be less than 0.02 mm, the flatness of the top surface of the long positioning post must be less than 0.02 mm, the parallelism between the top surface of the long positioning post and the bottom surface of the short positioning post must be less than 0.05 mm, the positional accuracy of the flange relative to the short positioning post as a reference must be less than 1 mm in diameter, the positional accuracy of the short positioning post on the same plane must be less than 0.2 mm in diameter, the positional accuracy of the long positioning post relative to the short positioning post as a reference must be less than 0.8 mm in diameter, and the perpendicularity of the groove bar relative to the bottom surface of the short positioning post as a reference must be 0.5 mm.

[0006] Quartz bases are structural components that require ferruling and welding. Before ferruling, the components need to be disassembled and manufactured. The dimensional and positional accuracy of these components is crucial for accurate ferruling positioning. The best machining method to ensure dimensional and positional accuracy is a CNC machining center. However, quartz products are hard and brittle, making traditional cutting tools unsuitable. Only very small diamond grinding heads can be used, resulting in low efficiency and high cost. Furthermore, gaps are necessary between components during ferruling. Precise positioning of components with these gaps becomes a significant challenge. Unwelded ferruled products exhibit low tensile and bending strength, further complicating the process of ensuring consistent product quality.

[0007] The existing manufacturing method for quartz bases is as follows: 1. First, disassemble the components, then machine them. The positioning posts are machined using centerless grinding and grooving. To ensure the positional tolerance of the positioning posts relative to the flange, the diameter of the positioning posts needs to be increased by 4 mm to allow for subsequent machining. Both the lower and upper bases are machined using a machining center. The grooved bars are machined using centerless grinding and grooving. To avoid cracks during welding between the flange and the grooved bars, the ends of the grooved bars are chamfered. 2. The long and short positioning posts are temporarily connected to the upper and lower bases respectively, welded, and stress-relief annealed. Then, they are placed on a fixed plate by applying wax. The fixed plate is mounted on a machining center using a fixture and ground. Then, it undergoes fine sintering, stress-relief annealing, dewaxing and cleaning, boiling and cleaning, and pure water cleaning to manufacture the lower and upper base assemblies. 3. Install the lower base assembly on the manually constructed positioning base on the left, and place the groove bar on the horizontal groove bar positioning base on the right. Perform temporary connection and welding, and perform stress-relief annealing in time. Then remove the semi-finished product from the jig, turn it around, and temporarily connect it to the base assembly in the same way. Then weld, finely heat and stress-relief annealing. 4. Post-weld grinding, cleaning, inspection and packaging.

[0008] Although the above processing method ensures that the positioning columns within the same flange assembly are correctly positioned relative to the lower base and the long positioning columns relative to the upper base due to machining (machining center), the flange assembly and the groove bar positioning base are not on the same base. The manual assembly of the positioning bases introduces significant datum errors, and the two-stage fendering makes it difficult to guarantee the coaxiality of the groove bar and positioning columns, the coaxiality of the two flanges, and the positional accuracy of the short positioning column on the lower base relative to the long positioning column on the upper base. Therefore, the fendering quality is highly unstable, requiring repeated adjustments and verifications to produce qualified products, resulting in low production efficiency. Furthermore, the manufacturing of the upper and lower base assemblies before welding the groove bar, along with the fendering, welding, stress-relief annealing, machining center grinding, precision firing, stress-relief annealing, and cleaning processes, results in a long process flow and high manufacturing costs.

[0009] The problems with traditional quartz base manufacturing methods are: 1. The product disassembly is relatively complex, the production capacity is low, and the processing skills of the fire processing personnel are highly required; 2. After multiple mortise and tenon joints, welding and machining, it is impossible to meet the product's positional and perpendicularity requirements; 3. The process flow is long and the manufacturing cost is high. Summary of the Invention

[0010] The purpose of this invention is to solve the problems of existing quartz base manufacturing processes, which involve multiple temporary joints, welding, and machining, resulting in failure to meet product position and perpendicularity requirements, low production capacity, substandard product quality, long process flow, and high manufacturing costs. This invention provides a high-quality quartz base and a manufacturing method for it. This method eliminates the need for repeated temporary joint fixture construction and adjustments, avoids human error, reduces manufacturing difficulty, and effectively improves product quality stability, production capacity, and production efficiency.

[0011] The technical solution adopted by this invention to achieve its first inventive objective is: a quartz base, comprising:

[0012] The lower base is a component used to connect the furnace bottom plate.

[0013] The upper base, parallel to the lower base and positioned above it, is a component used to connect the quartz boat.

[0014] An integrated groove bar, vertically connected to the lower base and the upper base, is used for supporting and positioning the heat-insulating quartz sheet. The upper end of the integrated groove bar extends upward through the upper base to form an integrated long positioning post, and the lower end of the integrated groove bar extends downward through the lower base to form an integrated short positioning post. The integrated groove bar, which is located between the upper base and the lower base, has several groove teeth evenly distributed on it.

[0015] Independent long positioning columns are temporarily fixed to the upper base and are evenly distributed with the integrated long columns.

[0016] Independent short positioning columns are temporarily fixed to the lower base and are evenly distributed with the integrated short columns.

[0017] This quartz base uses an integrated groove bar, which is manufactured as a single piece with the long and short positioning posts. The integrated groove bar can be directly connected to the upper and lower bases, avoiding the operational errors caused by multiple processing, adjustment, and temporary connection of the long positioning posts, groove bar, and short positioning posts. Because of the integrated groove bar, coaxiality errors between the long and short positioning posts are avoided, and parallelism and coaxiality errors between the upper and lower bases are reduced, greatly improving the quality and stability of the quartz base. For the independent long and short positioning posts, since the integrated groove bar ensures the parallelism and coaxiality requirements between the upper and lower bases, the independent long and short positioning posts can be directly connected by temporary connection, provided that the position is reliable. This makes operation more convenient, reduces operational errors, and ensures the overall quality and stability of the quartz base.

[0018] Preferably, the upper and lower bases are manufactured using laser processing. A central hole is provided at the center of each base, and a temporary connection hole is formed on the outer circumference of both bases. The integrated grooved bar is integrally and temporarily connected to the upper and lower bases. Since there is no need to manufacture flange assemblies, the upper and lower bases can be laser-processed, ensuring processing quality and overcoming the problem of insufficient processing capacity of CNC machining centers, thus greatly improving production efficiency. The direct temporary connection between the integrated grooved bar and the upper and lower bases overcomes the limitations of existing technologies, such as the need for chamfering the grooved bar, allowing machining allowances for long and short positioning posts, and increasing the outer diameter of the upper and lower bases. This saves material costs and improves both production efficiency and quality.

[0019] The technical solution adopted by the present invention to achieve its second objective is: a method for manufacturing a quartz base, which includes the following steps:

[0020] Step 1: Component manufacturing, including manufacturing the upper base, lower base, integrated groove bar, independent long positioning post, and independent short positioning post;

[0021] Step 2: Component fine sintering and annealing. The upper base, lower base, integrated groove bar, independent long positioning post and independent short positioning post are finely sintered and then annealed.

[0022] Step 3: Cleaning. After fine sintering and annealing, the upper base, lower base, integrated groove bar, independent long positioning column and independent short positioning column are cleaned by degreasing, nitric acid, hydrofluoric acid and pure water in sequence.

[0023] Step 4: Use a temporary joint fixture to temporarily join and demold the integrated groove bar, upper base, and lower base onto the temporary joint fixture for temporary joining. Temporarily join the independent short positioning post to the lower base and the independent long positioning post to the upper base to form a quartz base semi-finished product.

[0024] Step 5: Welding and annealing. Weld the dummy joints on the quartz base semi-finished product, and then perform annealing treatment.

[0025] Step 6: Fine firing. The welded quartz base semi-finished product is finely fired until it becomes transparent, and then annealed to relieve stress.

[0026] Step 7: Grinding: Grind the end faces of the upper and lower bases to achieve a flatness of 0.02 mm and a parallelism of 0.05 mm;

[0027] Step 8: Cleaning and inspection, then fabricating the quartz base.

[0028] This quartz base manufacturing method integrates all components of the quartz base using a single temporary-joining fixture for positioning and connection, followed by demolding. This eliminates the need for repeated fixture construction and adjustments, avoiding human error, reducing manufacturing difficulty, and improving product quality stability. Furthermore, the method eliminates the need to manufacture flange assemblies before temporary joining, saving time-consuming processes such as temporary joining, welding, CNC machining, precision firing, annealing, and cleaning. This reduces labor and equipment usage, significantly increasing production capacity. The method also integrates the groove bar with coaxial long and short positioning posts, eliminating the need for chamfering the groove bar, machining allowances for the long and short positioning posts, and increasing the outer diameter of the upper and lower bases, thus saving material costs. This not only improves product quality stability and increases production capacity but also significantly enhances production efficiency and greatly reduces manufacturing costs.

[0029] Preferably, in step 1, the upper and lower bases are laser-cut, followed by stress-relief annealing. The false joint angles and welding chamfers are ground on both sides of the false joint holes on the upper and lower bases, and a notch is created in the false joint holes. The integrated grooved bar, independent long positioning post, and independent short positioning post are manufactured using centerless grinding and grooving. Laser cutting of the upper and lower bases replaces CNC machining, not only solving the severe shortage of CNC machining center capacity but also increasing production efficiency tenfold. The integrated grooved bar, independent long positioning post, and independent short positioning post are manufactured using centerless grinding and grooving, ensuring dimensional requirements and improving product quality.

[0030] Preferably, the dummy connection in step 4 is performed using a dummy connection fixture, which includes a cylindrical dummy connection positioning fixture, a long positioning post demolding fixture, and a short positioning post demolding fixture. The cylindrical dummy connection fixture not only fully utilizes the structural characteristics of the quartz base to achieve precise positioning, but also uses the weight of the component itself instead of a clamping mechanism for pressing. It has fewer parts, a simpler structure, and is easier to process and assemble, thus reducing manufacturing costs. Using long positioning post demolding fixtures and short positioning post demolding fixtures for demolding can improve the stability of product quality and production efficiency after dummy connection.

[0031] Preferably, the cylindrical dummy-joining positioning fixture includes a fixture body, an upper cover, a core rod, and positioning components. The fixture body has a cylindrical frame structure with an upper mold and a lower mold. An inner cavity is provided inside the fixture body, and dummy-joining windows are provided around the perimeter of the fixture body. The lower mold has a lower mold center hole, an inner hole for supporting the upper base and for coarse positioning, a lower through hole for positioning the upper part of the independent long positioning post or groove rod, and a guide hole for guiding the long positioning post after dummy-joining and demolding. The upper mold has... The base has stepped holes for support and coarse positioning, and the top cover has stepped holes for positioning. The base stepped holes and the top cover stepped holes are coaxially arranged, with the top cover stepped holes located above the base stepped holes. The top cover is placed inside the top cover stepped holes. The top cover has a central hole and an upper through hole for positioning the lower part of the independent short positioning post and the groove bar. A semi-circular top cover directional hole is provided on the outer circumference of the top cover. The core rod passes through the central hole of the top cover and the central hole of the lower mold.

[0032] The aforementioned structure of the cylindrical dummy-joint positioning fixture facilitates high-quality dummy-joint of the quartz base, greatly improving the quality and stability of the quartz base. In use, the fixture is placed on a worktable, with the upper cover and fixture body forming a shaft-hole fit, creating a coarse positioning with a slight gap. A positioning component is inserted into the directional hole formed by the upper cover and fixture body to prevent rotation of the upper cover and ensure its orientation. All components of the quartz base are housed within the fixture body and the upper cover. The upper base is placed within the inner hole of the lower mold, using the inner hole as a coarse positioning hole and the bottom surface of the fixture body as a positioning surface. The lower base is placed within the stepped base hole of the upper mold, using the stepped base hole as a positioning hole and the bottom surface of the stepped base hole as a positioning surface. A mandrel passing through the center holes of the upper cover, lower base, upper base, and lower mold forms the fine positioning of the base, and is further oriented by positioning components and the upper and lower through holes. The integrated groove bar is positioned by the upper through hole on the upper cover, the lower through hole on the lower mold, and the worktable surface. The integrated groove bar is positioned by positioning components and limited by the mandrel. Independent long positioning pins are positioned by the lower through hole on the lower mold, and independent short positioning pins are positioned by the upper through hole on the upper cover. All these positioning surfaces and holes are located on the fixture body and the upper cover, and can be machined by CNC machine tools to achieve high positional and dimensional accuracy. Therefore, all components are positioned sufficiently and with high positioning accuracy.

[0033] Preferably, the diameter of the upper through hole is smaller than that of the lower through hole. Since the integrated groove bar is inserted through the upper through hole, passes through the lower base and the upper base, and finally enters the lower through hole, the upper through hole is a visible hole and also a guide hole. The smaller the upper through hole, the smaller the gap with the integrated groove bar, resulting in more precise guidance and a longer service life. The lower through hole is an invisible hole. The larger the lower through hole, the larger the gap with the integrated groove bar, making it easier to insert the groove bar.

[0034] Preferably, a cylindrical positioning sleeve is provided at the center hole of the lower mold, with the inner hole of the cylindrical positioning sleeve serving as the center hole of the lower mold. A bushing is provided at the lower through hole of the lower mold, with the inner hole of the bushing serving as the lower through hole of the lower body. A guide sleeve is provided at the guide hole of the lower mold, with the inner hole of the guide sleeve serving as the guide hole of the lower mold. An upper cover bushing is provided at the upper through hole of the upper cover, with the inner hole of the upper cover bushing serving as the upper through hole. The cylindrical positioning sleeve, bushing, and guide sleeve are all screwed to the fixture body, allowing for quick replacement. This improves the service life of the fixture, reduces its operating costs, and consequently reduces the manufacturing cost of the quartz base. The directional hole is a circular hole, facilitating observation and operation. The circular holes on the fixture body or upper cover can be directly machined in one operation on a machining center along with other features, reducing manufacturing difficulty.

[0035] Preferably, the quartz base is installed as follows: the upper base is inserted into the inner hole of the lower mold, and the positioning component is inserted into the lower through hole for positioning; the lower base is inserted into the base stepped hole of the upper mold; the upper cover is placed in the upper cover stepped hole to press the lower base tightly, and the positioning component is inserted into the upper through hole for positioning; a core rod is inserted downward from the center hole of the upper cover; multiple integrated grooved rods are inserted downward from the upper through hole into the lower through hole, ensuring that the upper and lower ends of the integrated grooved rods are respectively aligned with the upper... The end faces of the cover and the lower base are flush. A positioning insert from the positioning assembly is horizontally inserted into the inner cavity of the fixture to position the groove bar. The upper base on the lower mold is then temporarily connected to the integrated groove bar. The positioning assembly on the lower base is removed, and an independent long positioning post is inserted, temporarily connecting the independent long positioning post to the upper base. The fixture is then flipped and inverted, temporarily connecting the integrated groove bar to the lower base. The positioning assembly on the upper cover is then removed, and an independent short positioning post is inserted, temporarily connecting the independent short positioning post to the lower base, completing the temporary connection of the quartz base. This temporary connection method is simple to operate, has high manufacturing precision, produces good product quality, and ensures strong product stability.

[0036] Preferably, the long positioning post demolding fixture includes an upper template and a lower template. A long push rod and a guide post are provided between the upper and lower templates, and the long push rod and guide post are slidably connected to the upper template. A compression spring is sleeved on the long push rod and guide post, and the guide post extends upward to the upper part of the upper template. With this structure, the pre-attached quartz base, along with the cylindrical pre-attached fixture, can be placed on the demolding fixture through a guide hole. By pressing the body of the pre-attached fixture, the long positioning post, along with the pre-attached quartz base and the upper cover, can be ejected from the fixture body. This demolding fixture, with its compression spring mechanism, provides simple, quick, and stable demolding, and the guide rod provides precise guidance, effectively preventing human error.

[0037] Preferably, the dummy joint fixture with the quartz base after dummy joint is placed on the upper template of the long positioning post demolding fixture, and the guide post on the upper template is inserted into the guide hole of the lower mold of the dummy joint fixture. The fixture body is pressed down, the compression spring in the long positioning post demolding fixture is compressed, the fixture body moves downward, the long push rod pushes against the long positioning post, and pushes the quartz base upward to separate it from the fixture body. The upper cover and the quartz base are then removed to complete the demolding of the long positioning post.

[0038] Preferably, the short positioning post demolding fixture includes a part-removing sleeve, a top plate, a short ejector rod, and a long pin. The bottom of the part-removing sleeve is provided with a part-removing hole for placing the lower base. The diameter of the part-removing hole is larger than the diameter of the lower base and smaller than the diameter of the upper cover. The upper part of the part-removing sleeve is provided with a sleeve countersunk hole and a sleeve directional hole. The side of the part-removing sleeve is provided with a sleeve notch smaller than the sleeve radius. The top plate is provided with a top plate directional hole. The short ejector rod is set on the lower plate surface of the top plate. The demolding process is as follows: the quartz base and the upper cover after the long positioning post is demolded are placed into the part-removing hole and the countersunk hole. The long pin is inserted into the guide hole of the sleeve and the guide hole of the upper cover for orientation, so that the short ejector rod is aligned with the short positioning post. The top plate is pressed down, the quartz base moves downward, and the short positioning post and the lower base are demolded. The upper cover is suspended in mid-air using the part-removing hole on the part-removing sleeve. When force is applied to the top plate, the top plate presses down the short locating pin with the help of the ejector rod. The short locating pin disengages from the hole on the upper cover, completing the demolding process. The temporarily assembled quartz base can then be removed from the part-removing sleeve. This design is simple in structure, easy to operate, and provides stable quality.

[0039] Preferably, the component is subjected to fine annealing in step 2, which can reduce the roughness of the integral groove bar to less than 0.04 micrometers and the roughness of other components to less than 0.08 micrometers. Fine annealing can reduce the roughness of machined parts, round off sharp corners, eliminate burrs, reduce wear on the upper and lower through holes during dummy joints, and improve the service life of the dummy joint fixture.

[0040] Preferably, the welding in step 5 is performed independently of the temporary joint fixture. The welded part is removed using a long positioning post demolding fixture and a short positioning post demolding fixture, and then placed vertically on the work platform for welding. One side is welded first, followed by the other side, but the welded side always faces upwards. The joint is then smoothed with accumulated material. This design ensures unobstructed welding visibility, allows the molten welding rod to flow naturally into the chamfered surface and weld seam, resulting in high welding quality and high production efficiency.

[0041] Preferably, the grinding process in step 7 is applied to the upper and lower surfaces of the quartz base, namely the top surface of the long positioning post and the bottom surface of the short positioning post. The flatness and parallelism of the two surfaces can be controlled through the grinding process, which is conducive to the stable installation and correct placement of the quartz boat and facilitates the precise insertion of the silicon wafer into the quartz boat.

[0042] The beneficial effects of this invention are: 1. All components are positioned, connected and demolded by a temporary connection fixture, eliminating the need for repeated fixture construction and adjustment, thus avoiding human error, reducing manufacturing difficulty and improving product quality stability;

[0043] 2. The upper base and lower base are directly connected to the integrated groove bar, independent long positioning column and independent short positioning column, eliminating the need for flange assembly connection, welding, CNC machining, precision firing, annealing and cleaning processes, reducing labor hours and equipment occupation, and significantly improving production capacity;

[0044] 3. The upper and lower bases are processed by laser instead of CNC machining centers, which greatly improves production efficiency;

[0045] 4. The upper and lower bases are directly welded to the integrated groove bar, which saves the material consumption of welding rods required for the positioning post, the upper and lower bases, and the chamfering notch of the groove bar, thus reducing the material cost of the quartz base.

[0046] 5. The dummy joint fixture is manufactured in separate parts, and the vulnerable parts are made of easily replaceable bushings, directional sleeves, and guide sleeves, which improves the service life of the fixture and reduces the material cost, manufacturing cost and usage cost of the fixture.

[0047] This invention not only improves production capacity and efficiency, but also enhances product quality stability and significantly reduces manufacturing costs. Attached Figure Description

[0048] Figure 1 This is a schematic diagram of a quartz base according to the present invention;

[0049] Figure 2 This is a schematic diagram of a structure before the quartz base of the present invention is falsely connected;

[0050] Figure 3 This is a half-sectional view of the quartz base false connection process of the present invention;

[0051] Figure 4 This is a schematic diagram of the structure of the fixture body in the false connection fixture of the present invention;

[0052] Figure 5 This is a schematic diagram of a long positioning column demolding fixture in this invention;

[0053] Figure 6 This is a schematic diagram of a structure for the demolding process of the long positioning column in this invention;

[0054] Figure 7 This is a schematic diagram of a structure for the demolding process of long and short positioning columns in this invention;

[0055] Figure 8 This is a half-section view of the quartz base false connection process in Embodiment 2 of the present invention;

[0056] Figure 9 This is a schematic diagram of a semi-structure of the fixture body in an embodiment of the invention;

[0057] Figure 10 This is a schematic diagram of a half-section structure of the upper cover in Embodiment 2 of the present invention;

[0058] In the diagram: 100, upper base; 101, false connection hole; 102, break; 200, lower base; 300, integrated long positioning post; 400, integrated short positioning post; 500, integrated groove bar; 600, center hole; 700, groove tooth; 800, independent long positioning post; 900, independent short positioning post.

[0059] 19. Cylindrical dummy joint fixture, 1. Fixture body, 2. Top cover, 21. Top cover center hole, 22. Top through hole, 23. Top cover orientation hole, 24. Cover plate, 25. Cover plate bushing, 3. Core rod, 4. Groove rod positioning insert, 41. Insert center hole, 5. Upper mold, 51. Base stepped hole, 52. Top cover step, 53. Upper mold orientation hole, 6. Lower mold, 61. Lower mold center hole, 62. Inner hole, 63. Lower through hole, 64. Guide hole, 7. Inner cavity, 8. Dummy joint window, 9. Short pin, 10. Upper positioning pin, 11. Lower positioning pin, 12. C-shaped insert;

[0060] 13. Long positioning post demolding fixture; 131. Upper template; 132. Lower template; 133. Long ejector rod; 134. Guide post; 135. Compression spring.

[0061] 14. Short positioning pin demolding fixture; 141. Part removal sleeve; 142. Top plate; 143. Short ejector pin; 144. Long pin; 145. Notch.

[0062] 15. Support column, 16. Positioning sleeve, 17. Bushing, 18. Guide sleeve. Detailed Implementation

[0063] The present invention will now be described in detail with reference to specific embodiments and accompanying drawings.

[0064] Example 1:

[0065] exist Figure 1 , Figure 2 In the illustrated embodiment, a quartz base includes:

[0066] The lower base 200 is a component used to connect the furnace bottom plate.

[0067] The upper base 100, parallel to the lower base and positioned above the lower base, is a component used to connect the quartz boat.

[0068] An integrated groove bar 500 is vertically connected to the lower base 200 and the upper base 100, and is used for supporting and positioning the heat-insulating quartz sheet. The upper end of the integrated groove bar 500 passes through the upper base 100 and extends upward to form an integrated long positioning post 300, and the lower end of the integrated groove bar 500 passes through the lower base 200 and extends downward to form an integrated short positioning post 400. A plurality of groove teeth 700 are evenly distributed on the integrated groove bar between the upper base 100 and the lower base 200.

[0069] An independent long positioning column of 800mm is temporarily fixed to the upper base and is evenly distributed with the integrated long column.

[0070] Independent short positioning columns 900 are temporarily fixed to the lower base and are evenly distributed with the integrated short columns.

[0071] The upper base 100 and the lower base 200 are manufactured by laser processing. A central hole 600 is provided in the center of the lower base 200 and the upper base 100. A false connection hole 101 is provided on the outer circumference of the upper base 100 and the lower base 200. The integral groove bar 500 is integrally falsely connected to the upper base 100 and the lower base 200.

[0072] The quartz base in this embodiment is used for the oxidation and diffusion of 12-inch silicon wafers, connecting a quartz boat to the furnace bottom plate. The quartz base includes an upper base 100, a lower base 200, a long positioning post on the upper base, a short positioning post below the lower base, and groove bars between the upper and lower bases. The upper base 100 has a diameter of φ342.5±0.50 mm, and the lower base 200 has a diameter of φ357.5±0.50 mm. Both the upper and lower bases have a central hole 600 with a diameter of φ15±1.00 mm. The long positioning post has a length of 28±0.50 mm, the short positioning post has a length of 24±0.50 mm, and three groove bars are provided. Each groove bar has a length of 178±0.50 mm and a diameter of φ22±0.20 mm, the same as the long and short positioning posts. The groove bars 500 have groove teeth 700. There are four long positioning posts and four short positioning posts. Among them, there are three pairs of integrated long positioning posts 300 and integrated short positioning posts 400 that are coaxial with the groove bar and are manufactured as a single piece with the groove bar. There is one independent long positioning post 800 and one independent short positioning post 900.

[0073] The manufacturing method of this quartz base:

[0074] Step 1: Component manufacturing. As shown in the figure, manufacture the upper base, lower base, independent long positioning post, independent short positioning post, and integrated groove bar respectively.

[0075] 1. The upper and lower bases are first laser-cut. During cutting, the outer diameter of the upper base is controlled at φ342.5±0.20 mm, and the outer diameter of the lower base is controlled at φ357.5±0.20 mm. A false connection hole 101 is machined, with a diameter 4 mm larger than the locating post diameter φ22, and a dimensional tolerance controlled within ±0.10 mm. That is, the diameter of the false connection hole is controlled at φ26±0.10 mm, and the diameter and tolerance of the center hole are controlled at φ15 (+0.20 / 0) mm. After laser cutting, the upper and lower bases need to be stress-relieved annealed promptly. The false connection hole needs to be chamfered on both sides. The chamfered surfaces vary in size; the smaller chamfered surface (1x45°) is used for the false connection, and the larger chamfered surface (3x45°) is used for welding. To ensure the quality of the base false connection welding process, a break 102 is needed at any damaged chamfered area.

[0076] 2. Independent long positioning pins and independent short positioning pins are manufactured using centerless grinding and grooving. The diameter and tolerance of the positioning pins are controlled within φ22h7 (0 / -0.021) mm.

[0077] 3. The three integrated grooved bars are 242 mm long and are machined using a centerless grinder. The diameter and tolerance of the grooved bars are controlled within φ22f7 (0 / -0.021) mm. Then, the length and groove tooth size are controlled by groove cutting.

[0078] Step 2: Fine sintering and annealing of components. The upper base, lower base, integrated groove bar, independent long positioning post and independent short positioning post are finely sintered and then annealed. The roughness of the groove bar should be less than 0.04 micrometers, and the roughness of other components should be less than 0.08 micrometers.

[0079] Step 3: Cleaning. After fine sintering and annealing, the upper base, lower base, integrated groove bar, independent long positioning column and independent short positioning column are cleaned by degreasing, nitric acid cleaning, hydrofluoric acid cleaning and pure water cleaning in sequence.

[0080] Step 4: Use a temporary joint fixture to temporarily join and demold the integrated groove bar, upper base, and lower base onto the temporary joint fixture for temporary joining. Temporarily join the independent short positioning post to the lower base and the independent long positioning post to the upper base to form a quartz base semi-finished product.

[0081] A vertical temporary joint fixture is used for temporary jointing. The vertical temporary joint fixture includes a cylindrical temporary joint positioning fixture 19, a long positioning post demolding fixture 13, and a short positioning post demolding fixture 14.

[0082] like Figure 3 , Figure 4 As shown, the cylindrical dummy connection positioning fixture 19 includes a fixture body 1, an upper cover 2, a mandrel 3, and a positioning assembly. In this embodiment, the fixture body is an integral structure. The fixture body 1 has a cylindrical frame structure with an upper mold 5 and a lower mold 6. An inner cavity 7 is provided inside the fixture body 1, and dummy connection windows 8 are opened around the fixture body to facilitate the welding rod to extend into the cylinder for dummy connection. The thickness of the lower mold is equal to the height of the long positioning post, and the thickness of the upper cover is equal to the height of the short positioning post.

[0083] The lower mold 6 is provided with a lower mold center hole 61, an inner hole 62 for upper base support and coarse positioning, a lower through hole 63 for positioning the upper part of the independent long positioning post or groove bar, and a guide hole 64 for guiding the demolding after the long positioning post is temporarily connected; the upper mold 5 is provided with a base stepped hole 51 for lower base support and coarse positioning and an upper cover stepped hole 52 for upper cover positioning. The base stepped hole 51 and the upper cover stepped hole 52 are coaxially arranged and the upper cover stepped hole is located above the base stepped hole; the upper cover 2 is covered inside the upper cover stepped hole 52. The upper cover 2 is provided with an upper cover center hole 21 and an upper through hole 22 for positioning the lower part of the independent short positioning post and groove bar; a semi-circular upper cover directional hole 23 is provided on the outer circumference of the upper cover; the core rod 3 passes through the upper cover center hole 21 and the lower mold center hole 61.

[0084] The diameter of the lower mold center hole 61 on the fixture body is controlled at φ15H7 (+0.018 / 0) mm. Around the center hole are lower through holes 63 corresponding to the long positioning posts. The diameter of the lower through holes is slightly larger than the diameter of the long positioning posts, with dimensions and tolerances of φ22F8 (+0.053 / +0.02) mm. These are used for positioning the lower part of the independent long positioning posts or groove bars, with a fitting clearance of 0.02 (0.02+0) to 0.074 (0.053+0.021) mm. The lower mold is provided with guide holes 64, with a diameter and tolerance of φ20H8 (+0.033 / 0) mm, used for guiding the demolding after the long positioning posts are temporarily attached. An inner hole 62 is provided on the lower mold, which is coaxial with the center hole 61 of the lower mold. The diameter is slightly larger than the diameter of the upper base. The diameter and its tolerance are φ342.5 (+0.40 / +0.30) mm. It is used for the support and coarse positioning of the upper base 100, and forms a fitting clearance of 0.10 (0.30-0.20=0.10) to 0.60 (0.4+0.2) mm with the upper base.

[0085] A base stepped hole 51 is provided on the upper mold. The diameter of the base stepped hole 51 is slightly larger than the diameter of the lower base 200. The diameter and its tolerance are φ357.5 (+0.40 / +0.30) mm. It is used for the support and coarse positioning of the lower base and forms a fitting clearance of 0.10 (0.30-0.20=0.10) to 0.60 (0.40+0.20) mm with the lower base. A top cover stepped hole 52 is provided above the base stepped hole 51. Its diameter is φ370H7 (+0.057) mm. A semi-circular upper mold orientation hole 53 is provided on the circumference of the top cover stepped hole 52. Its diameter and tolerance are φ10H8 (+0.022 / 0) mm. The upper mold orientation hole 53 and the top cover orientation hole 53 cooperate to form a circular orientation hole. The base stepped hole and the top cover stepped hole are coaxial with the center hole of the top cover.

[0086] The upper cover 2 is a disc structure, located within the stepped hole 52 of the upper mold. Its outer diameter is slightly smaller than the diameter of the stepped hole, with a diameter and tolerance of φ370f6 (-0.062 / -0.098). It forms a fitting clearance of 0.062 to 0.155 mm with the stepped hole, allowing it to slide up and down. The upper cover has a center hole 21 coaxial with the outer circle. The diameter of the center hole 21 is equal to the diameter of the center hole 61 of the lower mold, φ15H7 (+0.018 / 0) mm. The surrounding area is provided with an upper through hole 22 corresponding to the short positioning post. The upper through hole 22 has a diameter of φ22H8 (+0.033 / 0) mm. The upper through hole 22 is used for positioning the independent short positioning post and the upper part of the groove bar (short positioning post). The maximum fitting clearance with the short positioning post is 0.054 (0.033+0.021) mm. The upper cover circumference is provided with an upper cover directional hole 23 with the same size and center point as the directional hole on the upper cover stepped hole circumference. Its diameter is φ10H8 (+0.022 / 0) mm.

[0087] The positioning assembly includes a grooved positioning insert 4, a core rod 3, a short pin 9, an upper positioning pin 10, a lower positioning pin 11, and a C-shaped insert 12.

[0088] The head of the groove bar positioning insert 4 is an isosceles trapezoid and the tail is rectangular. There is a center hole 41 in the middle. The diameter of the center hole 41 on the groove bar positioning insert is φ15F8 (+0.043 / +0.016) mm. There is a handle hole at the tail. The groove bar positioning insert 4 is inserted between the groove teeth in the middle of the integrated groove bar for groove bar orientation.

[0089] The mandrel 3 is a circular rod, which can be machined using a centerless grinder. The diameter of the mandrel 3 is slightly smaller than the diameter of the central hole 21 of the upper cover, and its diameter is 15h7 (0 / -0.011) mm. The head is tapered for guidance. The mandrel 3 passes sequentially through the upper cover 1, the lower base 200, the grooved rod positioning insert 4, the upper base 100, and the lower mold central hole 61. It forms a fitting clearance of 0 to 0.029 (0.018+0.011=0.029) mm with the central holes 21 of the upper cover and the lower mold central hole 61, and a clearance of 0.016 to 0.054 (0.043+0.011=0.029) mm with the central hole 41 of the insert on the grooved rod positioning insert. The small clearance of 0.054 mm can be used for positioning the grooved bar positioning insert. It forms a fitting clearance of 0 to 0.211 (0.20 + 0.011 = 0.211) mm with the center hole 600 on the upper base 6 and the lower base. It can be seen that the maximum fitting clearance of 0.211 mm between the mandrel 3 and the upper base 100 and the lower base 200 is significantly smaller than the maximum fitting clearance of 0.60 mm between the inner hole 62 of the lower mold and the upper base 100, and also smaller than the maximum fitting clearance of 0.60 mm between the stepped hole 51 of the base and the lower base 200. Using the mandrel 3 for positioning can improve the positioning accuracy of the upper base 100 and the lower base 200.

[0090] The short pin 9 is a cylindrical pin with a diameter of φ10h8 (0 / -0.022) mm. It is inserted into the circular directional hole formed by the upper mold directional hole 53 on the circumference of the upper cover stepped hole 52 and the upper cover directional hole 23 on the circumference of the upper cover. The maximum gap formed with the circular directional hole is 0.022+0.022=0.044 mm. It is used for the directional connection between the upper cover 2 and the upper mold 5, so that the upper through hole 22 on the upper cover is aligned with the lower through hole 63 on the lower mold.

[0091] The lower positioning pin 11 is used for the orientation of the upper base 100, and the upper positioning pin 10 is used for the orientation of the lower base 200. Both the upper and lower positioning pins are stepped pins. The lower positioning pin 11 passes through the dummy hole 101 on the upper base corresponding to the independent long positioning post and the lower through hole 63 on the lower mold. The upper positioning pin 10 passes through the dummy hole 101 on the lower base corresponding to the independent short positioning post and the upper through hole 22 on the upper cover. The small end diameter of the upper positioning pin 10 is φ22h7 (0 / -0.021), and the maximum gap between it and the upper through hole is 0.054 (0.033+0.021). The lower locating pin 11 has a small end diameter of φ22k7 (+0.023 / +0.002) mm, and a maximum clearance of 0.051 (0.053-0.002=0.051) mm when it mates with the lower through hole. Its large end diameter is φ26.2 (0 / -0.05) mm. The large end of the locating pin (near the small end) has a taper of 5-15° to eliminate the locating gap caused by manufacturing errors in the false connection hole. A C-shaped insert 12 is used to fix the upper locating pin 10 to prevent it from falling off due to its own weight.

[0092] Using this cylindrical dummy-fit positioning fixture for dummy-fitting, the maximum positional error of the short positioning post on the same side is: the maximum clearance between the short positioning post and the upper through hole + the maximum positional error between the upper through hole (CNC machine tool machining error) = (0.033 + 0.021) + 0.01 = 0.064 mm, which is significantly less than the product requirement of φ0.20 mm; the maximum positional error of the long positioning post on the same side is: the maximum clearance between the long positioning post and the lower through hole + the maximum positional error between the lower through hole = (0.053 + 0.021) + 0.01 = 0.084 mm, which is significantly less than the product requirement of φ0.20 mm; the maximum positional error of the long positioning post relative to the short positioning post is: the maximum clearance between the upper cover and the upper cover stepped hole + the maximum positional error between the upper cover stepped hole and the lower mold center hole (CNC machine tool machining error) = (0.033 + 0.021) + 0.01 = 0.084 mm. The maximum clearance between the short pin and the directional hole, the maximum clearance between the long positioning pin and the lower through hole, and the maximum clearance between the short positioning pin and the upper through hole are calculated as follows: 0.155 + 0.01 + 0.044 + 0.074 + 0.054 = 0.337 mm, which is significantly less than the product requirement of φ0.8 mm. The maximum perpendicularity error of the groove bar relative to the bottom surface of the short positioning pin is calculated as follows: the maximum clearance between the upper cover and the upper cover stepped hole, the maximum positional error of the upper cover stepped hole relative to the lower mold center hole (CNC machine tool machining error), the maximum clearance between the short pin and the directional hole, the maximum clearance between the groove bar and the lower through hole, and the maximum clearance between the groove bar and the upper through hole are calculated as follows: 0.155 + 0.01 + 0.044 + 0.074 + 0.054 = 0.337 mm, which is less than the product requirement of φ0.5 mm. The maximum positional error of the lower base relative to the short positioning post and its bottom surface: maximum clearance between the center hole of the upper cover and the mandrel + maximum clearance between the center hole of the upper base and the mandrel + maximum clearance between the upper through hole and the upper positioning pin = (0.018 + 0.011) + (0.20 + 0.011) + (0.033 + 0.021) = 0.294 mm, which is significantly less than the product requirement of φ1.0 mm. The maximum positional error of the upper base relative to the short positioning post and its bottom surface: maximum clearance between the center hole of the lower mold and the mandrel + maximum clearance between the center hole of the base and the mandrel + maximum clearance between the lower positioning pin and the lower through hole on the lower mold + maximum clearance between the upper cover and the upper cover stepped hole + maximum clearance between the short pin and the directional hole = (0.018 + 0.011) + (0.2 + 0.011) + (0.053 - 0.002) + 0.155 + 0.044 = 0.490 mm, which is significantly less than the product requirement of φ1.0 mm. The data above shows that the cylindrical dummy joint positioning fixture can ensure the positioning accuracy of all components, and the quartz base dummy joint can be completed in one go without adjustment.

[0093] The steps for simulating the quartz base are as follows: Insert the upper base into the inner hole of the lower mold, and insert the lower locating pin into the lower through hole for positioning. Insert the lower base into the stepped hole of the upper mold base. Place the upper cover in the stepped hole of the upper cover to press it against the lower base, and insert the upper locating pin into the upper through hole for positioning. Insert the mandrel downwards from the center hole of the upper cover. Insert multiple integrated grooved rods downwards from the upper through hole into the lower through hole, ensuring that the upper and lower ends of the integrated grooved rods extend respectively. On the outside of the upper and lower bases, insert the groove bar positioning piece horizontally into the inner cavity of the fixture to position the groove bar; temporarily connect the upper base on the lower mold with the integrated groove bar; pull out the lower positioning pin on the lower base, insert the independent long positioning post, and temporarily connect the independent long positioning post with the upper base; then flip the temporary fixture upside down, temporarily connect the integrated groove bar with the lower base, then pull out the upper positioning pin on the upper cover, insert the independent short positioning post, and temporarily connect the independent short positioning post with the lower base to complete the temporary connection of the quartz base.

[0094] After the initial connection, demolding is performed. A long positioning post demolding fixture is used to demold the long positioning post, and a short positioning post demolding fixture is used to demold the short positioning post.

[0095] like Figure 5 As shown, the long positioning post demolding fixture 13 includes an upper template 131, a lower template 132, a long push rod 133, a guide post 134, and a compression spring 135. The long push rod 133 and the guide post 134 are slidably connected to the upper template 131. The long push rod 133 and the guide post 134 are fitted with compression springs 135. The guide post 134 extends upward to the upper part of the upper template 131.

[0096] When demolding, the guide post 134 passes through the guide hole 64 on the lower mold of the cylindrical false connection fixture, the upper template 131 is fitted with or bolted to the lower mold 6 of the false connection fixture, the long push rod 133 is distributed corresponding to the long positioning post 300, and the diameter of the long push rod 133 is slightly smaller than the diameter of the long positioning post 300.

[0097] like Figure 6 As shown, the quartz base with the dummy connection is first placed on the long positioning post demolding fixture along with the cylindrical dummy connection positioning fixture. It is guided by the guide post 134 on the demolding fixture and the guide hole 64 (or guide sleeve hole) on the dummy connection fixture. Then, the fixture body is pressed down. The long push rod 133 and the quartz base remain stationary. The fixture body (including the upper template) and the quartz base (including the long push rod) move relative to each other. As the fixture body continues to move downward, the quartz base and the upper cover gradually separate from the lower through hole (insertion inner hole) on the lower mold and the base stepped hole and upper cover stepped hole on the upper mold. The quartz base and the upper cover are then removed and placed on the worktable to complete the demolding of the long positioning post of the quartz base. At the same time, the compression spring on the demolding fixture automatically resets to prepare for the demolding of the next product.

[0098] like Figure 7As shown, the short positioning post demolding fixture 14 includes a part-removing sleeve 141, a top plate 142, a short ejector rod 143, and a long pin 144. The part-removing sleeve has a notch 145 smaller than a semicircle. The part-removing sleeve has a part-removing hole 146, a countersunk hole 147, and a directional hole. The diameter of the part-removing hole is larger than the diameter of the lower base and smaller than the diameter of the upper cover. The diameter of the countersunk hole is slightly larger than the diameter of the upper cover, forming a small fitting clearance. The directional hole corresponds to the directional hole on the upper cover. The top plate has directional holes with the same position and diameter as the directional holes on the upper cover. The top plate has short ejector rods. The distribution of the short ejector rods corresponds to the guide holes of the upper cover. The diameter of the short ejector rods is slightly smaller than the diameter of the short positioning post. The short ejector rods are threadedly connected to the top plate. During operation, the quartz base and the top cover are placed on the part removal hole 146 and countersunk hole 147 of the part removal sleeve. The long pin is inserted into the directional hole for guiding the short ejector rod. The top plate assembly (top plate 142 and short ejector rod 143) is aligned with the countersunk hole 147 and directional hole of the cylinder and placed on the top cover 2. At this time, the short ejector rod is aligned with the short positioning post. Pressing down the top plate assembly will allow the short positioning post of the quartz base to fall out of the through hole (inner hole of the bushing) on ​​the top cover. The top plate assembly (top plate and short ejector rod), the top cover, and the quartz base are then removed from the part removal sleeve to complete the temporary demolding.

[0099] Step 5: Welding and annealing. Weld the temporary joints on the semi-finished quartz base and anneal them after welding. Take out the temporarily joined quartz base, place it upright on the work platform, and weld one side first, then turn it over and weld the other side. The broken parts can be smoothed by piling up material. Anneal promptly after welding.

[0100] Step 6: Fine firing. The welded quartz base semi-finished product is finely fired until it becomes transparent, and then annealed to relieve stress. All surfaces are finely fired until they are transparent and the roughness meets the product requirements. There should be no defects such as bubbles or air lines inside. Then anneal to relieve stress.

[0101] Step 7: Grinding: Grind the end faces of the upper and lower bases to achieve a flatness of 0.02 mm and a parallelism of 0.05 mm.

[0102] Step 8: Clean and inspect, make quartz base, package and store.

[0103] Example 2:

[0104] exist Figure 8 , Figure 9 In the embodiments shown, the technical solution is basically the same as that in Embodiment 1, except that the cylindrical dummy connection positioning fixture for dummy connection adopts a split assembly structure.

[0105] like Figure 8The quartz base cylindrical false connection positioning fixture shown includes a fixture body 1, an upper cover 2 and a positioning component. The positioning component includes a grooved positioning insert 4, a core rod 3, an upper positioning pin 10, a lower positioning pin 11 and a C-shaped insert 12.

[0106] like Figure 9 As shown, the fixture body 1 adopts an assembled cylindrical structure, which can be manufactured in parts and connected by cylindrical pins and screws. It includes an upper mold 5, a lower mold 6, a support column 15, screws and cylindrical pins. The upper mold 5 and the lower mold 6 are provided with screw through holes, countersunk holes and cylindrical pin holes. The upper mold 5 has an inner hole with a diameter larger than that of the lower base. The upper part of the inner hole has a base stepped hole 51 and an upper cover stepped hole 52. The upper cover stepped hole 52 is located above the base stepped hole 51. The diameter of the base stepped hole 51 is controlled at φ357.5 (+0.40 / +0.30), which is 0.10 to 0.60 mm larger than the diameter of the lower base 200, serving as support and coarse positioning for the lower base. The upper cover stepped hole 52 is used for upper cover support. A semi-circular upper mold orientation hole 53 is provided on the outer circumference of the upper cover stepped hole 52 for orientation, allowing the fixture body to align with the upper cover hole. The height of the base stepped hole 51 is 0.10 to 0.20 mm higher than the thickness of the lower base to prevent the upper cover from touching it and to eliminate rotational resistance when aligning the lower base hole. The lower mold 6 has a central hole with a diameter of φ15P7 (-0.011 / -0.029) mm. A positioning sleeve 16 is fitted into the central hole, with an outer diameter of φ15h6 (0 / -0.011) mm. The positioning sleeve 16 forms an interference fit (no clearance) with the central hole and a clearance fit with the lower mold 6, used for precise positioning of the upper base 100. The clearance is 0-0.211 mm. The inner hole of the positioning sleeve is the central hole 61 of the lower mold of the cylinder. The inner hole of the positioning sleeve has a diameter of φ10K7 (+0.005 / -0.010) mm and a height of 52 mm. Its perpendicularity tolerance can be controlled within φ0.03 mm, used for positioning the mandrel 3. The central positioning sleeve is far from the heat source; therefore, stainless steel is selected to improve its service life. The central positioning sleeve 16 is surrounded by a lower through hole 63, and a bushing 17 is provided at the lower through hole. The inner hole of the bushing is the lower through hole 63 on the lower mold. The diameter of the lower through hole is φ22F8 (+0.053 / +0.02). The bottom of the lower mold is provided with a guide hole 64, and a guide sleeve 18 is provided at the guide hole. The inner hole of the guide sleeve is the guide hole 64 of the lower mold. The support column 15 is provided with threaded holes and positioning pin holes at both ends. The threaded holes and positioning pin holes on both end faces should meet the principle of datum coincidence during machining to avoid positioning errors caused by datum non-coincidence. The relative positional error is less than φ0.05 mm. There are two or more support columns 15. The support columns 15 are of equal height, and a false connection window 8 is formed between adjacent support columns.

[0107] The support column 15 is I-shaped, wider at both ends and narrower in the middle. The wider ends facilitate connection with the upper and lower dies, while the narrower middle minimizes the diameter of the dummy connection fixture without affecting the insertion of the positioning insert 4, thus facilitating the dummy connection. Otherwise, it would affect the insertion of the welding rod, making the dummy connection difficult; the larger the diameter, the farther the dummy connection point is from the outer circle, making it more difficult for the welding rod to penetrate and dummy connect. Secondly, the I-shaped design of the support column also facilitates clamping during the final machining process, "machining one end face and its positioning hole and threaded hole," playing a crucial role in ensuring the height of the support column and the relative positional accuracy of the positioning holes.

[0108] The outer surface of the support column 15 is an arc surface, the radius of which is equal to the radius of the upper ring and the lower disk. The side of the support column is perpendicular to the lower mold, and the inner side of the support column and its two adjacent sides are planes. The two adjacent sides are parallel to each other and perpendicular to the inner side. The inner side has two process holes. This design facilitates the finding of a unified positioning reference during the manufacturing of the support column, simplifies the positioning design and manufacturing of the fixture, and results in relatively small errors in the relative position of each surface.

[0109] like Figure 10 As shown, in this embodiment, the upper cover 2 includes a cover plate 24, a core rod 3, and a bushing. The cover plate 24 has a central hole 21 with a diameter of φ15P7 (-0.011 / -0.029). A stepped core rod 3 with a length of 238 mm is provided at the central hole 21. The tail of the core rod has a flange-shaped tailstock. The diameter of the rear section of the core rod is φ15h6 (0 / -0.011) mm, which forms an interference fit (no clearance) with the central hole 21 of the upper cover and is connected with screws. The diameter of the front section of the core rod is φ10h6 (0 / -0.009) mm, which forms a transition fit with the inner hole of the central positioning sleeve 16 on the lower mold. The maximum clearance is 0.014 (0.005+0.009) mm. The positional tolerance of the front end of the core rod relative to its own bottom center can be controlled within φ0.05 mm. The core rod is far from the fire source. In order to improve its service life, stainless steel is selected as the material. The core rod is surrounded by an upper through hole corresponding to the short positioning post. An upper cover bushing 25 is provided at the upper through hole. The inner hole of the upper cover bushing 25 is the upper through hole 22. The diameter of the upper through hole is φ22H8 (+0.033 / 0). It is used for positioning the integrated groove rod and the independent short positioning post, forming a fitting gap of 0 to 0.054 mm with the positioning post. The upper cover bushing is very close to the fire source. To avoid contamination, high-purity graphite is selected as the material. The upper cover is provided with a semi-circular upper cover orientation hole 23 for orientation, which is used to align with the hole position of the lower mold (cylinder).

[0110] The positioning assembly includes a grooved positioning insert 4, a short pin 9, an upper positioning pin 10, a lower positioning pin 11, and a C-shaped insert 12.

[0111] The short pin 9 is a cylindrical pin, forming a 0-0.044 mm fit clearance with the directional hole, used for the orientation of the upper cover; the groove bar positioning insert 4 is used for the orientation of the groove bar, and the center hole of the groove bar positioning insert 4 is controlled at φ15F8 (+0.043 / +0.016) mm; the lower positioning pin 11 is used for the orientation of the upper base, and the upper positioning pin 10 is used for the orientation of the lower base. The upper and lower positioning pins are stepped pins. The lower positioning pin 11 passes through the dummy hole on the upper base corresponding to the independent long positioning post and the lower through hole on the lower mold, and the upper positioning pin 10 passes through the dummy hole on the lower base corresponding to the independent short positioning post and the upper through hole on the upper cover. The lower locating pin 11 has a small end diameter of φ22k7 (+0.023 / +0.002) and a maximum clearance of 0.051 (0.053-0.002=0.051) mm when it fits with the lower through hole (inner hole of bushing 17). The upper locating pin 10 has a small end diameter of φ22h7 (0 / -0.021) and a maximum clearance of 0.054 (0.033+0.021=0.054) mm when it fits with the upper through hole (inner hole of upper cover bushing 25). The large end diameter is φ26.2 (0 / -0.05) mm, and a 2x5° chamfer is provided near the small end. The small end is inserted into the inner hole of the upper cover bushing, and the large end is inserted into the false connection hole to form a clearance-free fit. The upper positioning pin 10 has a threaded hole at the center of its small end face. When the lower base is in the upper position, a C-shaped insert is inserted, and a screw is passed through the C-shaped insert to connect with the threaded hole. The upper positioning pin is tightened, forming a gapless fit with the lower base. The C-shaped insert can prevent the upper positioning pin from falling off due to its own weight.

[0112] The maximum positional error of the short positioning post on the same side in the above technical solution is: the maximum clearance between the short positioning post and the upper through hole + the maximum positional error between the upper through hole (CNC machine tool machining error) = (0.033 + 0.021) + 0.01 = 0.064 mm, which is significantly less than the product requirement of φ0.20 mm; the maximum positional error of the long positioning post on the same side is: the maximum clearance between the long positioning post and the lower through hole + the maximum positional error between the lower through hole = (0.053 + 0.021) + 0.01 = 0.084 mm, which is significantly less than the product requirement of φ0.20 mm. The maximum positional error of the long positioning post relative to the short positioning post: Maximum positional error of the mandrel tip relative to its own bottom center + Maximum clearance between the mandrel and the positioning sleeve + Maximum perpendicularity error of the positioning sleeve inner hole + Maximum clearance between the short pin and the directional hole + Maximum clearance between the short positioning post and the lower through hole + Maximum clearance between the long positioning post and the upper through hole = 0.05 + (0.005 + 0.009) + 0.03 + 0.044 + 0.074 + 0.054 = 0.266 mm, which is less than 0.3 mm in the first technical solution. 37 mm; The maximum perpendicularity error of the grooved rod relative to the bottom surface of the short positioning post: the maximum positional error of the mandrel front end relative to its own bottom center + the gap between the mandrel and the positioning sleeve + the maximum perpendicularity error of the inner hole of the positioning sleeve + the maximum gap between the short pin and the directional hole + the gap between the grooved rod and the lower through hole + the gap between the grooved rod and the upper through hole = 0.05 + (0.005 + 0.009) + 0.03 + 0.044 + 0.074 + 0.054 = 0.266 mm, which is less than φ0.337 mm in the first technical solution. The maximum positional error of the lower base relative to the short positioning post and its bottom surface: the gap between the center hole of the cover plate and the mandrel + the gap between the center hole of the base and the mandrel + the gap between the upper through hole and the upper positioning pin = (0.018 + 0.011) + (0.20 + 0.011) + (0.033 + 0.021) = 0.308 mm, which is significantly less than the product requirement of φ1.0 mm. The maximum positional error of the upper base relative to the short positioning post and its bottom surface: perpendicularity error of the mandrel relative to the cover plate + gap between the mandrel and the positioning sleeve + perpendicularity error of the inner hole of the positioning sleeve + gap between the center hole of the upper base and the mandrel + gap between the lower positioning pin and the lower through hole of the cylinder + maximum gap between the short pin and the directional hole = 0.05 + (0.005 + 0.009) + 0.03 + (0.2 + 0.011) + (0.053 - 0.002) + 0.044 = 0.400 mm, which is less than the 0.493 mm of the first technical solution. From the above data, it can be seen that this dummy fixture not only has a long service life but also high positioning accuracy, making this cylindrical dummy positioning fixture suitable for mass production.

[0113] 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 quartz base, characterized in that... include: The lower base (200) is a component used to connect the furnace bottom plate. The upper base (100), parallel to the lower base and positioned above the lower base, is a component used to connect the quartz boat. An integrated groove bar (500) is vertically connected to the lower base (200) and the upper base (100) for supporting and positioning the heat-insulating quartz sheet. The upper end of the integrated groove bar (500) extends upward through the upper base (100) to form an integrated long positioning post (300), and the lower end of the integrated groove bar (500) extends downward through the lower base (200) to form an integrated short positioning post (400). The integrated groove bar between the upper base (100) and the lower base (200) is provided with several groove teeth (700). Independent long positioning column (800) is temporarily fixed on the upper base and is evenly distributed with the integrated long column; Independent short positioning columns (900) are temporarily fixed to the lower base and are evenly distributed with the integrated short columns; After the spur joint is fixed, the spur joint is welded and then finely fired to make a quartz base.

2. The quartz base according to claim 1, characterized in that: The upper base (100) and lower base (200) are manufactured by laser processing. A central hole (600) is provided in the center of the lower base (200) and the upper base (100). A false connection hole (101) is provided on the outer circumference of the upper base and the lower base. The integral groove bar (500) is integrally falsely connected to the upper base (100) and the lower base (200). After welding and fine firing of the false connection part, an integral structure is formed.

3. A method for manufacturing a quartz base according to any one of claims 1 to 2, characterized in that... Includes the following steps: Step 1: Component manufacturing, manufacturing the upper base (100), lower base (200), integrated groove bar (500), independent long positioning post (800) and independent short positioning post (900) respectively. Step 2: Component fine sintering and annealing. The upper base, lower base, integrated groove bar, independent long positioning post and independent short positioning post are finely sintered and then annealed. Step 3: Cleaning. After fine sintering and annealing, the upper base, lower base, integrated groove bar, independent long positioning column and independent short positioning column are cleaned by degreasing, nitric acid, hydrofluoric acid and pure water in sequence. Step 4: Use a temporary joint fixture to temporarily join and demold the integrated groove bar (500), upper base (100), and lower base (200) on the temporary joint fixture for temporary joining. Temporarily join the independent short positioning post (900) to the lower base (200) and the independent long positioning post (800) to the upper base (100) to form a quartz base semi-finished product. Step 5: Welding and annealing. Weld the dummy joints on the quartz base semi-finished product, and then perform annealing treatment. Step 6: Fine firing. The welded quartz base semi-finished product is finely fired until it becomes transparent, and then annealed to relieve stress. Step 7: Grinding: Grinding the end faces of the upper and lower bases to achieve a flatness of 0.02 mm and a parallelism of 0.05 mm; Step 8: Cleaning and inspection, then fabricating the quartz base.

4. The method for manufacturing a quartz base according to claim 3, characterized in that: In step 1, the upper and lower bases are laser-cut and then stress-relieved annealed. The false joint angles and welding chamfers are ground on both sides of the false joint holes of the upper and lower bases, and a notch is opened in the false joint holes. The integrated groove bar, independent long positioning post and independent short positioning post are manufactured by centerless grinding and grooving.

5. The method for manufacturing a quartz base according to claim 3, characterized in that: The temporary joint fixtures mentioned in step 4 include a cylindrical temporary joint positioning fixture (19), a long positioning post demolding fixture (13), and a short positioning post demolding fixture (14).

6. The method for manufacturing a quartz base according to claim 5, characterized in that: The cylindrical dummy-joining positioning fixture (19) includes a fixture body (1), an upper cover (2), a core rod (3), and a positioning assembly. The fixture body (1) has a cylindrical frame structure with an upper mold (5) and a lower mold (6). An inner cavity (7) is provided inside the fixture body, and dummy-joining windows (8) are provided around the fixture body. The lower mold has a lower mold center hole (61), an inner hole (62) for supporting the upper base and coarse positioning, a lower through hole (63) for positioning the upper part of the independent long positioning post or groove rod, and a guide hole (64) for guiding the demolding after dummy-joining of the long positioning post. The upper mold has a lower base support and The base stepped hole (51) for coarse positioning and the upper cover stepped hole (52) for upper cover positioning are coaxially arranged, and the upper cover stepped hole (52) is located above the base stepped hole (51); the upper cover (2) is placed inside the upper cover stepped hole (52), and the upper cover is provided with an upper cover center hole (21) and an upper through hole (22) for positioning the independent short positioning post and the lower part of the groove bar; a semi-circular upper cover orientation hole (23) is provided on the outer circumference of the upper cover; the core rod (3) passes through the upper cover center hole (21) and the lower mold center hole (61).

7. The method for manufacturing a quartz base according to claim 6, characterized in that: The steps for simulating the quartz base are as follows: Insert the upper base (100) into the inner hole (62) of the lower mold, and insert the positioning component into the lower through hole (63) for positioning. Insert the lower base (200) into the base stepped hole (51) of the upper mold. Place the upper cover (2) in the upper cover stepped hole (52) to press it against the lower base (200), and insert the positioning component into the upper through hole (22) for positioning. Insert the mandrel (3) downwards from the center hole (21) of the upper cover. Insert multiple integrated grooved rods (500) downwards from the upper through hole (22) into the lower through hole (63), and make... The upper and lower ends of the integrated groove bar (500) are flush with the end faces of the upper cover (2) and the lower base (200), respectively. The positioning component is horizontally inserted into the inner cavity (7) of the fixture to position the integrated groove bar (500). The upper base and the integrated groove bar are temporarily connected on the lower mold. The positioning component on the lower base is pulled out, and an independent long positioning post (800) is inserted to temporarily connect the independent long positioning post and the upper base. Then the temporary fixture is flipped and inverted to temporarily connect the integrated groove bar and the lower base. The positioning component on the upper cover is pulled out, and an independent short positioning post (900) is inserted to temporarily connect the independent short positioning post and the lower base to complete the temporary connection of the quartz base.

8. The method for manufacturing a quartz base according to claim 7, characterized in that: The long positioning post demolding fixture (13) includes an upper template (131) and a lower template (132). A long push rod (133) and a guide post (134) are provided between the upper template and the lower template. The long push rod (133) and the guide post (134) are slidably connected to the upper template (131). A compression spring (135) is sleeved on the long push rod (133) and the guide post (134). The guide post extends upward to the upper part of the upper template.

9. The method for manufacturing a quartz base according to claim 8, characterized in that: Place the dummy-joint fixture with the quartz base after dummy-joint onto the upper template (131) of the long positioning post demolding fixture, and insert the guide post (134) on the upper template into the guide hole (64) of the lower mold (6) of the fixture body. Press down on the fixture body (1), the compression spring (135) in the long positioning post demolding fixture is compressed, the fixture body (1) moves downward, the long push rod (133) pushes against the long positioning post (300), and pushes the quartz base upward to separate it from the fixture body (1). Take out the upper cover (2) and the quartz base to complete the demolding of the long positioning post.

10. The method for manufacturing a quartz base according to claim 9, characterized in that: The short positioning post demolding fixture (14) includes a part-removing sleeve (141), a top plate (142), a short ejector rod (143), and a long pin (144). The part-removing sleeve has a part-removing hole (146), the diameter of which is larger than the diameter of the lower base (200) and smaller than the diameter of the upper cover (2). The upper part of the part-removing sleeve is provided with a countersunk hole (147) and a directional hole. The side of the part-removing sleeve has a sleeve notch (147) smaller than the sleeve radius. 45), the top plate is provided with a top plate orientation hole, and the short push rod (143) is set on the lower plate surface of the top plate; the demolding process is as follows: after the long positioning post is demolded, the quartz base and the top cover are placed into the take-up hole and the countersunk hole, and the long pin is inserted into the guide hole of the sleeve and the guide hole of the top cover for orientation, so that the short push rod (143) is aligned with the short positioning post (400), and the top plate (142) is pressed down, the quartz base moves downward, and the short positioning post and the lower base are demolded.

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