Mold for reducing the height of cut-off material of a quartz crucible and preparation device

Abstract

The application improves a mold for reducing the cutting edge height of a quartz crucible and a preparation device. The mold comprises an inner wall, the inner wall comprises a straight wall, a circular arc wall and a bottom wall, the circular arc wall connects the straight wall and the bottom wall, wherein the circular arc wall to the bottom wall is a circular arc part, the preset position of the port to the straight wall is a port part, the port part and the circular arc part are an intermediate part, and the inner diameter size of the circular arc part, the inner diameter size of the intermediate part and the inner diameter size of the port part increase in turn. By increasing the inner diameter size of the mold from the bottom to the port in turn, the thickness of the quartz sand distribution gradually increases from the bottom to the port during the melting process, so that the heat loss of the melting cavity near the port can be reduced, the port thickness of the quartz crucible can be increased, the straight wall thickness uniformity of the quartz crucible can be improved, and the cutting edge height of the quartz crucible can be reduced. On the basis of ensuring the product qualified rate, the utilization rate of quartz sand is improved, and the manufacturing cost of the quartz crucible is reduced.

Description

Technical Field

[0001] This invention relates to the field of quartz crucible manufacturing technology, specifically to a mold and preparation device for reducing the height of the cutting edge material of a quartz crucible. Background Technology

[0002] Quartz sand has special applications, primarily in high-tech fields such as optical glass, electronic materials, semiconductor materials, solar cells, and optical fibers. Its characteristics include a simple chemical composition, no pollution, high crystallinity, good heat resistance, and high mechanical strength, thus finding wide application in high-tech sectors. The market demand for high-purity quartz sand is showing a steady growth trend, and the market size is continuously expanding.

[0003] Quartz crucibles are essential materials for pulling large-diameter single-crystal silicon and developing large-scale integrated circuits. With the continuous increase in market demand for quartz sand, its price has risen steadily, leading to a corresponding increase in the manufacturing cost of quartz crucibles. Currently, quartz crucibles are primarily manufactured using the high-temperature electric arc melting method. Before melting, high-purity quartz sand is poured into the inner surface of a mold. Using centrifugal force and a forming rod, the crucible-shaped rotating device is rotated back to the electrode rod. The electrode is then arc-ignited and inserted into the formed powder cavity, rapidly melting it into the crucible-shaped quartz. After cooling, the crucible blank is removed, completing the production of a quartz crucible blank. However, during the quartz crucible melting process, heat dissipates faster closer to the mold end in the melting cavity, resulting in a thinner end and a lower end size. To improve the product yield, currently, the only option is to cut off more edge material, thus reducing the utilization rate of quartz sand and increasing the manufacturing cost of quartz crucibles.

[0004] In the prior art, for example, invention patent application number CN200910207795.2 discloses a mold for manufacturing quartz crucibles. This mold includes an annular heat-insulating barrier material with an inner diameter smaller than the mold's inner diameter but larger than the quartz crucible's inner diameter. This annular heat-insulating barrier material is disposed on the inner circumferential wall of the upper opening portion of the mold corresponding to the upper region of the quartz crucible, thereby pre-shaping the mold shape to correspond to the upper part of the crucible. However, even after adding the annular heat-insulating barrier material, the height of the quartz crucible cutting edge remains at 120mm, which is still too high and cannot meet the current requirements for the height of the quartz crucible cutting edge. Summary of the Invention

[0005] In view of this, the present invention provides a mold for reducing the height of the cutting edge material of a quartz crucible, so as to solve the technical problem that the cutting edge material height is too high after the existing quartz crucible is melted.

[0006] The technical solution adopted by this invention to solve its technical problem is:

[0007] A mold for reducing the height of the cutting edge material of a quartz crucible includes an inner wall, which comprises a straight wall, an arc wall, and a bottom wall. The arc wall connects the straight wall and the bottom wall. The area between the arc wall and the bottom wall is an arc portion. A predetermined position from the port to the straight wall is a port portion. The area between the port portion and the arc portion is an intermediate portion. The inner diameter of the arc portion, the inner diameter of the intermediate portion, and the inner diameter of the port portion increase sequentially.

[0008] Preferably, the port of the port portion is the first position, the upper end of the middle portion is the second position, and the position where the arc of the arc portion is tangent to the straight wall is the third position. The inner diameter of the third position, the inner diameter of the second position, and the inner diameter of the first position increase sequentially.

[0009] Preferably, the interval between the first position and the second position is 200-270 mm.

[0010] Preferably, the angle between the port portion and the middle portion is W1, and the angle between the middle portion and the arc portion is W2, wherein W1>W2.

[0011] Preferably, W1 is 0.4-1.9 degrees.

[0012] Preferably, W2 is 0-0.35 degrees.

[0013] The present invention also provides a preparation apparatus for reducing the height of the cutting edge material of a quartz crucible.

[0014] A preparation apparatus for reducing the height of the cutting edge material of a quartz crucible includes a mold as described above and a forming fixture. The forming fixture includes a straight arm, a bottom wall, an arc wall, and an ejector pin. The arc wall connects the straight arm and the bottom wall. The ejector pin is installed at the end of the bottom wall. The forming fixture is connected to the mold through the ejector pin.

[0015] Preferably, the forming fixture is inserted vertically into the mold at a preset angle to the straight wall of the mold.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] This invention designs the mold so that the inner diameter of the arc portion, the middle portion, and the port portion increases sequentially, meaning the inner diameter of the mold increases from the bottom to the port. This results in a gradual increase in the thickness of the quartz sand distribution from the bottom to the port during the melting process. This reduces heat loss from the melting chamber near the port, increases the port thickness of the quartz crucible, improves the uniformity of the straight wall thickness of the quartz crucible, and consequently reduces the height of the quartz crucible cutting edge. While ensuring the product qualification rate, this invention improves the utilization rate of quartz sand and reduces the manufacturing cost of the quartz crucible. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the mold for reducing the height of the cutting edge material of the quartz crucible according to the present invention.

[0019] Figure 2 This is a schematic diagram of the molding fixture of the present invention.

[0020] Figure 3 This is a schematic diagram of the preparation device for reducing the height of the quartz crucible cutting edge material according to the present invention.

[0021] In the figure: preparation device 1, mold 10, inner wall 100, port part 110, middle part 120, arc part 130, forming jig 20, jig straight wall 210, jig bottom wall 220, jig arc wall 230, ejector pin 240, quartz sand 300. Detailed Implementation

[0022] The technical solutions and effects of the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0023] Please refer to Figure 1 A mold 10 for reducing the height of the cutting edge material in a quartz crucible includes an inner wall 100, which comprises a straight wall, an arc-shaped wall, and a bottom wall. The arc-shaped wall connects the straight wall and the bottom wall. An arc-shaped portion 130 is formed between the arc-shaped wall and the bottom wall. A predetermined position from the end to the straight wall is a port portion 110. A middle portion 120 is formed between the port portion 110 and the arc-shaped portion 130. The inner diameter of the arc-shaped portion 130, the middle portion 120, and the port portion 110 increases sequentially. The predetermined position can be set according to the size of the mold; the smaller the mold size, the closer the predetermined position is to the port.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] Because the mold is in direct contact with the water cooling device during the quartz crucible melting process, the quartz sand in direct contact with the mold loses heat quickly, especially near the end. This results in a thinner end for the quartz crucible. Currently, to improve the yield rate, the only solution is to cut off a larger portion of the edge material. This invention addresses this by designing the inner diameter of the mold's arc section, then the middle section, and finally the end section, increasing sequentially from the bottom to the end. This design allows the quartz sand thickness to gradually increase from the bottom to the end during melting, reducing heat loss near the end of the melting chamber, increasing the end thickness of the quartz crucible, improving the uniformity of the crucible's straight wall thickness, and consequently reducing the height of the edge material cut. This minimizes quartz sand loss due to excessive edge material, effectively improving quartz sand utilization and reducing manufacturing costs while maintaining a high yield rate. Meanwhile, the reduced height of the quartz crucible cutting edge material allows for one-time cutting, effectively improving cutting efficiency and achieving cost reduction and efficiency improvement.

[0026] In some embodiments, the inner diameter of the arc portion 130, the middle portion 120, and the port portion 110 can increase in a non-uniform manner. That is, the increase in the inner diameter of the port portion 110 relative to the inner diameter of the middle portion 120 can be greater than the increase in the inner diameter of the middle portion 120 relative to the inner diameter of the arc portion 130. This results in a difference between the slope of the straight wall at the port portion 110 and the slope of the straight wall at the middle portion 120 (e.g., ...). Figure 1 (As shown). This is because during the melting process of the quartz crucible, heat dissipates faster closer to the port in the melting cavity. By using uneven thickening, the inner diameter of the port can be made thicker, while the inner diameter of the middle part does not change much. This reduces heat loss at the port, resulting in a thicker port for the quartz crucible and less change in the size of the middle part. This more accurately solves the problem of the thin port of existing quartz crucibles, thereby reducing the height of the quartz crucible cutting edge, improving the utilization rate of the quartz crucible, and reducing the manufacturing cost of the quartz crucible. In other embodiments, the inner diameter of the arc portion 130, the inner diameter of the middle portion 120, and the inner diameter of the port portion 110 increase sequentially or uniformly. That is, the inner diameter of the bottom of the arc portion 130 increases uniformly to the inner diameter of the port portion 110, with the same increase at each point. This makes the slope of the straight wall at the port portion 110 the same as the slope of the straight wall at the middle portion 120, thereby reducing the height of the quartz crucible cutting edge and facilitating mold making.

[0027] In some embodiments, when the inner diameter of the port portion 110, the middle portion 120, and the arc portion 130 of the mold inner wall 10 increases sequentially, the corresponding outer wall size of the mold can be the same as the existing outer wall size of the mold. Only the thickness between the inner and outer walls changes with the inner diameter of the inner wall. At the port with the largest inner diameter, the thickness between the inner and outer walls at the port is also the thinnest, thereby saving material for mold manufacturing and reducing mold production costs. In other embodiments, when the inner diameter of the port portion 110, the middle portion 120, and the arc portion 130 of the mold inner wall 10 increases sequentially, the thickness between the inner and outer walls remains unchanged. This allows the outer wall size to change with the inner diameter of the inner wall, resulting in a more uniform temperature on the mold, which is more conducive to the melting of the quartz crucible.

[0028] Furthermore, such as Figure 1 As shown, the port of the port portion 110 is the first position D1, the upper end of the middle portion 120 is the second position D2, and the position where the arc of the arc portion 130 is tangent to the straight wall is the third position D3. The inner diameter of the third position is D3, the inner diameter of the second position is D2, and the inner diameter of the first position is D1, increasing sequentially. The inner diameter D3 can be based on the position where the arc of the arc portion 130 is tangent to the straight wall, and then the dimensions of D2 and D1 can be designed based on the reference inner diameter D3, the mold dimensions, and a pre-set correspondence table.

[0029] Furthermore, the interval between the first position D1 and the second position D2 is 200-270mm.

[0030] Furthermore, the angle between the port portion 110 and the middle portion 120 is W1, and the angle between the middle portion 120 and the arc portion 130 is W2, where W1 > W2. Since heat dissipates faster closer to the port in the melting cavity, W1 > W2 ensures that the difference between the inner diameter of the port portion and the inner diameter of the middle portion is greater than the difference between the inner diameter of the middle portion and the inner diameter of the arc portion. This results in a larger inner diameter at the port, better addressing the issue of the fastest heat dissipation at the port. Simultaneously, it allows for a thicker layer of quartz sand at the port, reducing the height of the quartz crucible cutting edge and minimizing quartz sand loss due to excessive edge material. W1 can be the angle between the first and second positions, and W2 can be the angle between the second and third positions. Further, W1 can be 0.4-1.9 degrees, and W2 can be 0-0.35 degrees.

[0031] The parameters in Table 1 can be seen below.

[0032] Table 1

[0033]

[0034] Table 1 provides the corresponding design parameters for the inner diameter of molds of different sizes. For example, when manufacturing a 24-inch mold, the inner diameter D3 can be based on the position where the arc wall and the straight wall are tangent (the third position). This inner diameter is consistent with the existing inner diameter of a 24-inch quartz crucible mold. Then, the position 200mm from the port is designated as the second position. The angle between the second and third positions is designed to be 0.09 degrees. Next, the angle between the first and second positions is designed to be 0.6 degrees. This results in the inner diameters of the third, second, and first positions increasing sequentially. A 24-inch mold manufactured in this manner, used to melt a quartz crucible, can ensure that the cut edge height of the melted quartz crucible is less than or equal to 90mm.

[0035] Please also refer to Figure 2 and Figure 3 A preparation apparatus 1 for reducing the height of the cutting edge material of a quartz crucible, as described above, includes a mold 10 and a forming fixture 20. The forming fixture 20 includes a fixture straight arm 210, a fixture bottom wall 220, a fixture arc wall 230, and an ejector pin 240. The fixture arc wall 230 connects the fixture straight arm 210 and the fixture bottom wall 220. The ejector pin 240 is installed at the end of the fixture bottom wall 220. The forming fixture 20 is connected to the mold 10 through the ejector pin 240.

[0036] Furthermore, the forming fixture 20 is vertically inserted into the mold 10, forming a preset angle with the straight wall of the mold 10.

[0037] The mold 10 has a positioning hole at the center of its bottom wall, which facilitates the insertion of an ejector pin. The molding fixture 20 can vertically insert the ejector pin 240 into the positioning hole to fix the molding fixture 20 to the mold 10. This creates a preset angle between the vertical wall of the mold 10 and the molding fixture 20. Since the molding fixture 20 is vertically inserted into the mold 10, the preset angles are W1 and W2, where W1 is the angle between the end portion 110 and the middle portion 120, and W2 is the angle between the middle portion 120 and the arc portion 130, with W1 > W2.

[0038] The preparation method of the quartz crucible includes the following steps: Starting the rotation of mold 10, tilting mold 10 at a 60-degree angle, pouring quartz sand 300 onto the straight wall of mold 10, and continuing to rotate mold 10; vertically inserting the ejector pin 240 of forming jig 20 into the positioning hole on the bottom wall of mold 10, and using the forming jig 20 to smooth the quartz sand 300 on the straight wall of mold 10, thus forming the quartz sand 300. The thickness of the quartz sand during forming is as follows: Figure 3As shown, the shaded area represents the distribution of quartz sand. Specifically, the thickness of quartz sand 300 at the port is T1, the thickness at the upper part of the middle section is T2, and the thickness at the point where the arc and the straight wall are tangent is T3, with T1 > T2 > T3. After the quartz sand is formed, the mold 10 is adjusted to 90 degrees (vertical position), and the forming fixture 20 is removed from the mold 10. Then, high temperature is generated by arc discharge to rapidly melt the quartz sand. Throughout this process, the mold 10 remains rotating. After the high-purity quartz sand has melted, the mold 10 continues to rotate, and after natural cooling, it is removed, thus obtaining the quartz crucible blank. After a preliminary inspection to ensure the quartz crucible blank is free of black spots, bubbles, and cracks, the dimensions of the quartz crucible blank are measured to ensure they meet the process requirements. If qualified, it proceeds to cold working. Next, the quartz crucible blank undergoes sandblasting, cutting, and chamfering. The total thickness and the thickness of the transparent layer of the quartz crucible blank are measured. If qualified, it undergoes ultrasonic cleaning and high-temperature drying. Finally, the inner and outer surfaces and protrusions of the quartz crucible are inspected for defects such as black spots, bubbles, scratches, indentations, and foreign objects. If they pass the inspection, they are vacuum-packed to obtain the finished quartz crucible.

[0039] During the quartz sand distribution process, the mold rotates at a given speed, while the forming fixture remains stationary at a certain distance from the inner wall of the mold. The quartz sand is evenly and smoothly distributed on the inner wall of the mold under the scraping action of the forming fixture. Since the inner diameter of the mold is D1>D2>D3, the quartz sand distribution is T1>T2>T3. Because heat dissipates faster closer to the port in the melting cavity, and the thickness of the quartz sand gradually increases from the bottom to the port, heat loss at the port is reduced. This results in the final straight wall thickness of the quartz crucible being T1≈T2≈T3, improving the uniformity of the straight wall thickness of the product. Simultaneously, it reduces the cutting edge height of the quartz crucible, ensuring it is ≤90mm, meeting the requirements for one-time cutting by an automatic cutting machine, significantly improving cutting efficiency, and thus increasing the utilization rate of quartz sand during production. This results in significant cost reduction and efficiency improvement, and a marked increase in operational efficiency. Furthermore, the increasing inner diameter of the mold from the bottom to the port further facilitates the demolding of the quartz crucible.

[0040] The above-disclosed embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of the invention. Those skilled in the art will understand that implementing all or part of the above-described embodiments and making equivalent changes in accordance with the claims of the present invention are still within the scope of the invention.

Claims

1. A mold for reducing the height of the cutting edge material of a quartz crucible, characterized in that, The device includes an inner wall, which comprises a straight wall, an arc-shaped wall, and a bottom wall. The arc-shaped wall connects the straight wall and the bottom wall. The area between the arc-shaped wall and the bottom wall is an arc-shaped portion. A predetermined position from the port to the straight wall is a port portion. The area between the port portion and the arc-shaped portion is a middle portion. The inner diameter of the arc-shaped portion, the middle portion, and the port portion increases sequentially. The port of the port portion is a first position. The upper end of the middle portion is a second position. The position where the arc of the arc-shaped portion is tangent to the straight wall is a third position. The inner diameter of the third position, the second position, and the first position increases sequentially. The interval between the first position and the second position is 200-270mm. The angle between the port portion and the middle portion is W1, and the angle between the middle portion and the arc-shaped portion is W2, where W1 > W2. W1 is 0.4-1.9 degrees, and W2 is 0-0.35 degrees.

2. A preparation apparatus for reducing the height of the cutting edge material of a quartz crucible, characterized in that, The mold and forming fixture as described in claim 1 are included. The forming fixture includes a straight arm, a bottom wall, an arc wall, and an ejector pin. The arc wall connects the straight arm and the bottom wall. The ejector pin is installed at the end of the bottom wall. The forming fixture is connected to the mold through the ejector pin.

3. The preparation apparatus for reducing the height of the quartz crucible cutting edge material according to claim 2, characterized in that, The forming fixture is inserted vertically into the mold, forming a preset angle with the straight wall of the mold.

Images