Crucible mold and crucible melting process

Abstract

The invention discloses a crucible mold and a crucible melting process, and relates to the technical field of crucible preparation. The mold body comprises a mold opening part, a straight wall section and a mold bottom which are connected in sequence, a plurality of vacuum air holes used for exhausting air are distributed in the straight wall section, and the hole diameters of the vacuum air holes are gradually increased from the side, close to the mold bottom, of the straight wall section to the side, close to the mold opening part, of the straight wall section; the intervals of the vacuum air holes in the circumferential direction of the mold body are distributed in a gradually increasing mode from the side, close to the mold bottom, of the straight wall section to the side, close to the mold opening, of the straight wall section. According to the crucible mold, the vacuum air holes far away from the straight wall section are arranged to be sparse and large according to the distance between the vacuum air holes and the air exhaust pipeline at the bottom of the crucible mold, so that the pipeline resistance can be reduced, the situation of insufficient long-distance air exhaust pressure can be relieved, the problem of bubble increase at the opening part of the quartz crucible can be effectively improved, and the quality of the quartz crucible can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of crucible preparation, and more specifically, to a crucible mold and a crucible melting process. Background Art

[0002] The quartz crucible is divided into a transparent layer without bubbles and a bubble layer full of bubbles from the inside to the outside. The quartz crucible is generally prepared by the arc melting method, that is, adding specific quartz sand to the cast iron mold, using a scraper of a specific size to scrape the sand into shape, and then extending a high-voltage arc into the center of the mold to heat and melt. During this process, the mold needs to rotate at a certain speed, and the gas that may generate bubbles is extracted from the transparent layer on the outside of the mold. In this process, a bubble layer is formed on the outer wall of the crucible, and a transparent layer is formed on the inner wall of the crucible.

[0003] Traditional crucible molds often use one-piece cast iron molds, and the crucible mold is evenly distributed with vacuum holes. These holes are conical in shape, with the smaller diameter side closer to the outer surface. The crucible mold also sits on a water-cooling jacket, secured by bolts at the crucible mold mouth. The interior of the crucible mold and the water-cooling jacket form a cavity for vacuuming. A vacuum line is located in the center of the water-cooling jacket, directly below the crucible mold. Because the vacuum holes are evenly distributed in the crucible mold, bubbles at the crucible mouth are far from the vacuum line, making them difficult to extract. This results in a high number of bubbles at the crucible mouth and poor quality quartz crucibles.

[0004] Therefore, how to improve the bubble problem at the mouth of the quartz crucible and improve the quality of the quartz crucible has become a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0005] In view of this, the purpose of the present application is to provide a crucible mold to improve the bubble problem at the mouth of the quartz crucible and improve the quality of the quartz crucible.

[0006] Another object of the present application is to provide a crucible melting process using the above-mentioned crucible mold.

[0007] To achieve the above objectives, this application provides the following technical solutions:

[0008] A crucible mold, comprising:

[0009] A mold body, the mold body includes a mold mouth, a straight wall section and a mold bottom connected in sequence, the straight wall section is distributed with a plurality of vacuum air holes for exhausting air, the aperture of each vacuum air hole is distributed in an increasing manner from the side of the straight wall section close to the mold bottom toward the side of the straight wall section close to the mold mouth, and the spacing of each vacuum air hole along the circumferential direction of the mold body is distributed in an increasing manner from the side of the straight wall section close to the mold bottom toward the side of the straight wall section close to the mold mouth.

[0010] Optionally, in the above crucible mold, one of the mold mouth, the straight wall section and the mold bottom is provided with a first protrusion, and the other is provided with a first groove matching the first protrusion.

[0011] Optionally, in the above crucible mold, the straight wall section includes an upper straight wall section, a middle straight wall section and a lower straight wall section connected in sequence, the upper straight wall section is connected to the mold mouth, and the lower straight wall section is connected to the mold bottom.

[0012] Optionally, in the above crucible mold, one of two adjacent ones of the upper straight wall segment, the middle straight wall segment and the lower straight wall segment is provided with a second protrusion, and the other one is provided with a second groove matching the second protrusion.

[0013] Optionally, in the above crucible mold, the aperture of each vacuum pore of the upper straight wall segment is larger than the aperture of each vacuum pore of the middle straight wall segment; and / or,

[0014] The aperture of each of the vacuum air holes in the middle straight wall section is larger than the aperture of each of the vacuum air holes in the lower straight wall section.

[0015] Optionally, in the above crucible mold, the spacing between the vacuum air holes of the upper straight wall section along the circumferential direction of the mold body is greater than the spacing between the vacuum air holes of the middle straight wall section along the circumferential direction of the mold body; and / or,

[0016] The intervals between the vacuum air holes of the middle straight wall section along the circumferential direction of the mold body are greater than the intervals between the vacuum air holes of the lower straight wall section along the circumferential direction of the mold body.

[0017] Optionally, in the above crucible mold, the heights of the upper straight wall section, the middle straight wall section and the lower straight wall section are all 100 mm to 200 mm; and / or,

[0018] The diameter of the vacuum vents in the upper straight wall section is 6 mm to 10 mm; and / or,

[0019] The vacuum vents of the upper straight wall section are spaced 7° to 10° along the circumferential direction of the mold body; and / or,

[0020] The diameter of the vacuum vents in the middle straight wall section is 4 mm to 7 mm; and / or,

[0021] The vacuum vents of the middle straight wall section are spaced 3° to 5° apart along the circumferential direction of the mold body; and / or,

[0022] The diameter of the vacuum vents of the lower straight wall section is 3 mm to 6 mm; and / or,

[0023] The vacuum air holes of the lower straight wall section are spaced apart by 2° to 4° along the circumferential direction of the mold body.

[0024] Optionally, in the above crucible mold, the height of the mold mouth is 120 mm to 150 mm; and / or,

[0025] The height of the straight wall section is 60% to 80% of the height of the mold body; and / or,

[0026] The height of the bottom of the mold is 120 mm to 155 mm; and / or,

[0027] The aperture of the vacuum pores is 3 mm to 10 mm.

[0028] Optionally, in the above crucible mold, the mold mouth, the straight wall section and the mold bottom each include a plurality of spliced connections along the circumferential direction of the mold body.

[0029] A crucible melting process, using the crucible mold as described in any one of the above items, comprises the steps of:

[0030] Melt the inner layer of quartz sand, set the arc power to 2000KW~5000KW and turn on the vacuum pump, and melt for 1min~3min;

[0031] To initially form a transparent layer, reduce the arc power by 15% to 50%, and melt for 3 minutes to 15 minutes to initially form the transparent layer;

[0032] Turn off the vacuum pump and melt for 7 to 10 minutes;

[0033] Solidification molding: reduce the arc power by 15% to 30% and melt for 15 minutes to 25 minutes to allow the quartz crucible to solidify and form.

[0034] The crucible mold provided by the present application comprises a mold body composed of a mold mouth, a straight wall section, and a mold bottom connected in sequence, and a plurality of vacuum vents are distributed in the straight wall section. At the same time, according to the distance from the exhaust pipe at the bottom of the crucible mold, the aperture of each vacuum vent increases from the side of the straight wall section near the mold bottom to the side of the straight wall section near the mold mouth, and the spacing of each vacuum vent along the circumferential direction of the mold body increases from the side of the straight wall section near the mold bottom to the side of the straight wall section near the mold mouth, thereby reducing pipeline resistance, improving the situation of insufficient long-distance exhaust pressure at the mold mouth, and further effectively improving the problem of increased bubbles at the quartz crucible mouth, thereby improving the quality of the quartz crucible. As can be seen from the above example, the crucible mold provided by the present application, by arranging the vacuum vents farther away from the straight wall section in a sparse and large manner according to the distance from the exhaust pipe at the bottom of the crucible mold, can reduce pipeline resistance, alleviate the situation of insufficient long-distance exhaust pressure, effectively improve the problem of increased bubbles at the quartz crucible mouth, and improve the quality of the quartz crucible.

[0035] The technical features mentioned above, the technical features described below, and the technical features shown individually in the accompanying drawings may be combined arbitrarily, as long as the combined technical features do not conflict with each other. All possible feature combinations are technical contents explicitly described in this document. Any of the multiple sub-features included in the same statement can be applied independently and does not necessarily have to be applied in conjunction with the other sub-features. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without any creative work.

[0037] Figure 1 A schematic structural diagram of a crucible mold provided in an embodiment of the present application;

[0038] Figure 2 Provided in the embodiments of this application Figure 1 Middle AA section;

[0039] Figure 3 A schematic structural diagram of a first protrusion provided in an embodiment of the present application;

[0040] Figure 4 A schematic structural diagram of the first groove provided in an embodiment of the present application;

[0041] Figure 5 A schematic structural diagram of the middle straight wall section provided in an embodiment of the present application;

[0042] Figure 6 Provided in the embodiments of this application Figure 5 Middle BB cross-section;

[0043] Figure 7 A schematic diagram of the assembly of a crucible mold provided in an embodiment of the present application;

[0044] Figure 8 Provided in the embodiments of this application Figure 7 mid-CC cross-section;

[0045] Figure 9 A flow chart of a crucible melting process provided in an embodiment of the present application;

[0046] Figure 10 A schematic diagram comparing the bubble results of the traditional crucible mold and the new crucible mold provided in the embodiments of the present application;

[0047] Figure 11 A schematic diagram comparing the bubble results at the R corner of the traditional smelting process and the new smelting process provided in the embodiment of the present application;

[0048] Figure 12 Schematic diagram comparing the bubble results at the crucible mouth of the traditional smelting process and the new smelting process provided in the embodiments of the present application.

[0049] Wherein, 100 is the mold body, 10 is the mold mouth, 20 is the straight wall section, 30 is the mold bottom, 40 is the first protrusion, and 50 is the first groove;

[0050] 21 is a vacuum air hole, 22 is an upper straight wall section, 23 is a middle straight wall section, 24 is a lower straight wall section, 25 is a second protrusion, and 26 is a second groove;

[0051] 200 is a water cooling jacket;

[0052] 300 is an exhaust pipe. DETAILED DESCRIPTION

[0053] The core of this application is to provide a crucible mold to improve the bubble problem at the mouth of the quartz crucible and improve the quality of the quartz crucible.

[0054] Another core of the present application is to provide a crucible melting process using the above-mentioned crucible mold.

[0055] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0056] Quartz crucibles are an important auxiliary material for single crystal silicon growth. With the advancement of single crystal silicon growth technology, there is a higher demand for quartz crucible quality. Quartz crucibles are made from high-purity quartz sand. The gaps between quartz sand particles and gas-liquid inclusions in the sand can introduce bubbles into the crucible, affecting its quality.

[0057] The quartz crucible is divided into a transparent layer without bubbles and a bubble layer full of bubbles from the inside to the outside. The quartz crucible is generally prepared by the arc melting method, that is, adding specific quartz sand to the cast iron mold, using a scraper of a specific size to scrape the sand into shape, and then extending a high-voltage arc into the center of the mold to heat and melt. During this process, the mold needs to rotate at a certain speed, and the gas that may generate bubbles is extracted from the transparent layer on the outside of the mold. In this process, a bubble layer is formed on the outer wall of the crucible, and a transparent layer is formed on the inner wall of the crucible.

[0058] Traditional crucible molds often use one-piece cast iron molds, and the crucible mold is evenly distributed with vacuum holes. These holes are conical in shape, with the smaller diameter side closer to the outer surface. The crucible mold also sits on a water-cooling jacket, secured by bolts at the crucible mold mouth. The interior of the crucible mold and the water-cooling jacket form a cavity for vacuuming. A vacuum line is located in the center of the water-cooling jacket, directly below the crucible mold. Because the vacuum holes are evenly distributed in the crucible mold, bubbles at the crucible mouth are far from the vacuum line, making them difficult to extract. This results in a high number of bubbles at the crucible mouth and poor quality quartz crucibles.

[0059] For this reason, Figure 1 As shown, the present invention discloses a crucible mold, including a mold body 100. By arranging the vacuum vents 21 farther away from the straight wall section 20 according to the distance from the exhaust pipe at the bottom 30 of the crucible mold, the vacuum vents 21 are arranged sparsely and large. This can reduce pipe resistance, alleviate the problem of insufficient exhaust pressure at long distances, effectively improve the problem of increased bubbles at the mouth of the quartz crucible, and enhance the quality of the quartz crucible.

[0060] The following will be combined Figures 1 to 8 The crucible mold disclosed in the embodiments of the present application is specifically explained and illustrated.

[0061] like Figure 1 As shown, the mold body 100 may include a mold mouth 10, a straight wall section 20 and a mold bottom 30 connected in sequence. The straight wall section 20 is provided with a plurality of vacuum vents 21 that can be evacuated through an evacuation pipe 300. Figure 8As shown, according to the distance from the exhaust pipe of the mold bottom 30, the aperture of each vacuum pore 21 increases from the side of the straight wall section 20 close to the mold bottom 30 to the side of the straight wall section 20 close to the mold mouth 10. At the same time, the spacing of each vacuum pore 21 along the circumferential direction of the mold body 100 increases from the side of the straight wall section 20 close to the mold bottom 30 to the side of the straight wall section 20 close to the mold mouth 10. This can reduce pipeline resistance and improve the problem of insufficient long-distance exhaust pressure at the mold mouth 10, thereby effectively improving the problem of increased bubbles at the mouth of the quartz crucible and improving the quality of the quartz crucible. It should be noted that the vacuum pore 21 adopts a conical structure, with the smaller diameter side close to the outer surface of the mold body 100 and the larger diameter side located on the inner surface of the mold body 100. Here, the aperture of the vacuum pore 21 refers to the large diameter end of the vacuum pore 21, and unless otherwise specified below, the aperture of the vacuum pore 21 refers to the large diameter end of the vacuum pore 21.

[0062] like Figure 2 As shown, the mold mouth 10, the straight wall section 20 and the mold bottom 30 can be connected in a detachable manner to facilitate disassembly and maintenance of the crucible mold.

[0063] In some embodiments, one of the adjacent two of the mold mouth 10, the straight wall section 20 and the mold bottom 30 is provided with a first protrusion 40, and the other is provided with a first groove 50 that cooperates with the first protrusion 40, that is, Figure 2 As shown, a first protrusion 40 can be provided at the top of the straight wall section 20, a first groove 50 can be provided at the bottom of the straight wall section 20, and a first groove 50 that cooperates with the first protrusion 40 at the top of the straight wall section 20 can be provided at the bottom of the mold mouth 10, and a first protrusion 40 that cooperates with the first groove 50 at the bottom of the straight wall section 20 can be provided on the top surface of the mold bottom 30. Of course, a first groove 50 can also be provided at the top of the straight wall section 20, a first protrusion 40 can be provided at the bottom of the straight wall section 20, and a first protrusion 40 that cooperates with the first groove 50 at the top of the straight wall section 20 can be provided at the bottom of the mold mouth 10, and a first groove 50 that cooperates with the first protrusion 40 at the bottom of the straight wall section 20 can be provided on the top surface of the mold bottom 30, so that the first protrusion 40 can be inserted into the first groove 50 to realize a detachable connection between the mold mouth 10, the straight wall section 20 and the mold bottom 30.

[0064] In some embodiments, as Figure 3 and Figure 4As shown, the first protrusion 40 can be arranged in an annular manner along the circumference of the crucible mold, and the first groove 50 is adapted to the first protrusion 40, that is, the first groove 50 is also arranged in an annular manner along the circumference of the crucible mold to ensure the reliability of the detachable connection between the mold mouth 10, the straight wall section 20, and the mold bottom 30. Optionally, the first protrusion 40 can adopt a T-shaped cross-section, and the first groove 50 can adopt a T-shaped groove adapted to the first protrusion 40, so that while achieving the installation and positioning between the adjacent two of the mold mouth 10, the straight wall section 20, and the mold bottom 30, the mold mouth 10, the straight wall section 20, and the mold bottom 30 can be axially limited. Of course, the first protrusion 40 can also adopt a C-shaped cross-section or an Ω-shaped cross-section, and the first groove 50 can adopt a C-shaped groove or an Ω-groove adapted to the first protrusion 40, which is not limited herein.

[0065] In some embodiments, in order to facilitate the installation between the mold mouth 10, the straight wall section 20 and the mold bottom 30, as shown in FIG. Figure 1 and Figure 3 As shown, the mold mouth 10, the straight wall section 20, and the mold bottom 30 can each include multiple spliced connections along the circumferential direction of the mold body 100, that is, the mold mouth 10, the straight wall section 20, and the mold bottom 30 can be composed of two, three, or more parts along the circumferential direction of the mold body 100, so that when the mold mouth 10, the straight wall section 20, and the mold bottom 30 are installed, the first protrusion 40 can be slid into the end opening of the first groove 50 until the first protrusion 40 is completely inserted into the first groove 50. Optionally, the mold mouth 10, the straight wall section 20, and the mold bottom 30 are all spliced in three pieces to facilitate the installation of the mold mouth 10, the straight wall section 20, and the mold bottom 30.

[0066] During installation, first install the mold mouth 10, straight wall section 20 and mold bottom 30 of each petal, then insert the assembled mold mouth 10, straight wall section 20 and mold bottom 30 of each petal into the cold water jacket 200 in sequence, and at the same time fix the mold mouth 10 of each petal to the open end wall of the cold water jacket 200 by fasteners such as bolts, thereby completing the assembly of the crucible mold. Figure 7 and Figure 8 shown.

[0067] In some embodiments, the height of the mold mouth 10 can be 120mm to 150mm, the height of the straight wall section 20 can be 60% to 80% of the height of the mold body 100, and the height of the mold bottom 30 can be 120mm to 155mm. At the same time, the aperture of the vacuum pores 21 can be 3mm to 10mm, and is distributed in an increasing manner from the mold bottom 30 toward the mold mouth 10.

[0068] In some embodiments, as Figures 1 to 3As shown, the straight wall section 20 may include an upper straight wall section 22 , a middle straight wall section 23 and a lower straight wall section 24 connected in sequence, the upper straight wall section 22 is connected to the mold mouth 10 , and the lower straight wall section 24 is connected to the mold bottom 30 . At the same time, the aperture of each vacuum air hole 21 of the upper straight wall section 22 can be larger than the aperture of each vacuum air hole 21 of the middle straight wall section 23, the aperture of each vacuum air hole 21 of the middle straight wall section 23 can be larger than the aperture of each vacuum air hole 21 of the lower straight wall section 24, the spacing of each vacuum air hole 21 of the upper straight wall section 22 along the circumferential direction of the mold body 100 can be larger than the spacing of each vacuum air hole 21 of the middle straight wall section 23 along the circumferential direction of the mold body 100, the spacing of each vacuum air hole 21 of the middle straight wall section 23 along the circumferential direction of the mold body 100 can be larger than the spacing of each vacuum air hole 21 of the lower straight wall section 24 along the circumferential direction of the mold body 100, so that the vacuum air holes 21 of the straight wall section 20 farther away from the exhaust pipe 300 are set to be sparse and large, which can reduce the pipeline resistance, alleviate the situation of insufficient exhaust pressure at a long distance, effectively improve the problem of increased bubbles at the mouth of the quartz crucible, and improve the quality of the quartz crucible.

[0069] like Figure 2 As shown, the upper straight wall section 22, the middle straight wall section 23 and the lower straight wall section 24 can be connected in a detachable manner, so that any one of the upper straight wall section 22, the middle straight wall section 23 and the lower straight wall section 24 can be replaced to meet the preparation requirements of quartz crucibles of different sizes and qualities.

[0070] In some embodiments, as Figure 2 As shown, one of the adjacent two of the upper straight wall section 22, the middle straight wall section 23 and the lower straight wall section 24 is provided with a second protrusion 25, and the other is provided with a second groove 26 that cooperates with the second protrusion 25, that is, the top surface of the middle straight wall section 23 can be provided with the second protrusion 25, and the bottom surface of the middle straight wall section 23 can be provided with the second groove 26, and at the same time, the bottom surface of the upper straight wall section 22 is provided with a second groove 26 that cooperates with the second protrusion 25 on the top surface of the middle straight wall section 23, and the top surface of the lower straight wall section 24 is provided with a second protrusion 25 that cooperates with the second groove 26 on the bottom surface of the middle straight wall section 23. 5. Of course, a second groove 26 may be provided on the top surface of the middle straight wall section 23, and a second protrusion 25 may be provided on the bottom surface of the middle straight wall section 23. At the same time, a second protrusion 25 that cooperates with the second groove 26 on the top surface of the middle straight wall section 23 is provided on the bottom surface of the upper straight wall section 22, and a second groove 26 that cooperates with the second protrusion 25 on the bottom surface of the middle straight wall section 23 is provided on the top surface of the lower straight wall section 24. The second protrusion 25 can be inserted into the second groove 26 to achieve a detachable connection between the upper straight wall section 22, the middle straight wall section 23 and the lower straight wall section 24.

[0071] In some embodiments, as Figure 5 and Figure 6As shown, the second protrusion 25 can be arranged in an annular manner along the circumference of the crucible mold, and the second groove 26 is adapted to the second protrusion 25. That is, the second groove 26 is also arranged in an annular manner along the circumference of the crucible mold to ensure the reliability of the detachable connection between adjacent two of the upper straight wall section 22, the middle straight wall section 23, and the lower straight wall section 24. Optionally, the second protrusion 25 can have a T-shaped cross-section, and the second groove 26 can be a T-shaped groove adapted to the second protrusion 25. This can achieve installation and positioning between adjacent two of the upper straight wall section 22, the middle straight wall section 23, and the lower straight wall section 24 while also axially limiting the upper straight wall section 22, the middle straight wall section 23, and the lower straight wall section 24. Of course, the second protrusion 25 can also have a C-shaped cross-section or an Ω-shaped cross-section, and the second groove 26 can be a C-shaped groove or an Ω-groove adapted to the second protrusion 25, but this is not limited herein.

[0072] In some embodiments, the straight wall section 20 can be divided into an upper straight wall section 22, a middle straight wall section 23, and a lower straight wall section 24 at intervals of 100 mm to 200 mm. That is, the heights of the upper straight wall section 22, the middle straight wall section 23, and the lower straight wall section 24 can all be 100 mm to 200 mm. The diameter of the vacuum vents 21 in the upper straight wall section 22 can be 6 mm to 10 mm, and the spacing of the vacuum vents 21 in the upper straight wall section 22 along the circumferential direction of the mold body 100 can be 7° to 10°. The diameter of the vacuum vents 21 in the middle straight wall section 23 can be 4 mm to 7 mm, and the spacing of the vacuum vents 21 in the middle straight wall section 23 along the circumferential direction of the mold body 100 can be 3° to 5°. The aperture of the vacuum air holes 21 of the lower straight wall section 24 can be 3mm to 6mm, and the spacing of the vacuum air holes 21 of the lower straight wall section 24 along the circumferential direction of the mold body 100 can be 2° to 4°, so that the aperture of each vacuum air hole 21 is distributed in an increasing manner from the side of the straight wall section 20 close to the mold bottom 30 toward the side of the straight wall section 20 close to the mold mouth 10, and the spacing of each vacuum air hole 21 along the circumferential direction of the mold body 100 is distributed in an increasing manner from the side of the straight wall section 20 close to the mold bottom 30 toward the side of the straight wall section 20 close to the mold mouth 10, thereby reducing the pipeline resistance, improving the situation of insufficient long-distance exhaust pressure at the mold mouth 10, effectively improving the problem of increased bubbles at the mouth of the quartz crucible, and improving the quality of the quartz crucible.

[0073] The crucible mold disclosed in the embodiment of the present application is composed of a mold body 100 consisting of a mold mouth 10, a straight wall section 20 and a mold bottom 30 connected in sequence, and a plurality of vacuum air holes 21 are distributed in the straight wall section 20. At the same time, according to the distance from the exhaust pipe 300 of the crucible mold bottom 30, the aperture of each vacuum air hole 21 is distributed in an increasing manner from the side of the straight wall section 20 close to the mold bottom 30 toward the side of the straight wall section 20 close to the mold mouth 10, and the spacing of each vacuum air hole 21 along the circumferential direction of the mold body 100 is distributed in an increasing manner from the side of the straight wall section 20 close to the mold bottom 30 toward the side of the straight wall section 20 close to the mold mouth 10, thereby reducing the pipeline resistance, improving the situation of insufficient long-distance exhaust pressure of the mold mouth 10, and further effectively improving the problem of increased bubbles at the mouth of the quartz crucible, thereby improving the quality of the quartz crucible.

[0074] The crucible mold disclosed in the embodiment of the present application can reduce pipeline resistance and alleviate the problem of insufficient exhaust pressure at a long distance by arranging the vacuum air holes 21 farther away from the straight wall section 20 according to the distance from the exhaust pipe at the bottom 30 of the crucible mold. It can effectively improve the problem of increased bubbles at the mouth of the quartz crucible and improve the quality of the quartz crucible.

[0075] In some embodiments, the vacuum air holes 21 of the upper straight wall section 22 are tapered holes with a large diameter of 10 mm and a small diameter of 6 mm, and the circumferential spacing is 8°. The vacuum air holes 21 of the middle straight wall section 23 are tapered holes with a large diameter of 8 mm and a small diameter of 6 mm, and the circumferential spacing is 5°. The vacuum air holes 21 of the lower straight wall section 24 are tapered holes with a large diameter of 6 mm and a small diameter of 3 mm, and the circumferential spacing is 3°. The crucible models are 33 mm to 650 mm, and 10 quartz crucibles of each type are melted. Figure 10 As shown, the bubble detection device detects the quartz crucible mouth and shows that the bubbles at the crucible mouth of the quartz crucible melted by the crucible mold of the present application can be reduced by about 50%. It should be noted that, Figure 10 The left side in the middle is a quartz crucible melted by a traditional crucible mold, and the right side is a quartz crucible melted by the crucible mold in this application.

[0076] In the above embodiment, since the crucible mold adopts a split structure, there are gaps. During loading and unloading, the remaining quartz sand in the gaps needs to be cleaned. At the same time, due to the gaps, the outer layer of quartz sand can be preferentially made of quartz sand with lower purity.

[0077] The traditional crucible melting process typically consists of a heating phase and a melting phase. During the heating phase, the arc power is rapidly increased to a specified power of 2000KW to 5000KW, and the melting process lasts for 2 minutes. The melting phase then continues for about 25 to 40 minutes at a specified arc power fluctuation until the melting is complete. Due to the long, high-power melting process, the quartz sand rapidly becomes molten from the inside out. The thicker the molten quartz, the higher the load on the vacuum system, resulting in more bubbles remaining in the final quartz crucible, which affects the quality of the quartz crucible.

[0078] For this reason, Figure 9 As shown, the present embodiment also discloses a crucible melting process, which uses the crucible mold disclosed in the above embodiment, and thus has all the technical effects of the above crucible mold. This article will not repeat them here. The crucible melting process includes step S100 melting the inner layer of quartz sand, step S101 initially forming a transparent layer, step S102 turning off the vacuum pump, and step S103 solidification and forming.

[0079] Step S100, melting the inner layer of quartz sand;

[0080] Rapidly increase the arc power to 2000KW~5000KW and start the vacuum pump, melting for 1min~3min to quickly melt the quartz sand located in the inner layer of the crucible mold.

[0081] Step S101, preliminarily forming a transparent layer;

[0082] Reduce the arc power by 15% to 50%, melt for 3 to 15 minutes, and at the same time, vacuum the inner layer of molten quartz sand to quickly complete the process of extracting bubbles, initially forming a transparent layer. The outer layer of quartz sand is affected by the power and the melting progress slows down.

[0083] Step S102, turning off the vacuum pump;

[0084] Turn off the vacuum pump and melt for 7 to 10 minutes.

[0085] Step S103, solidification molding;

[0086] The arc power is further reduced by 15% to 30%, and the melting is continued for 15 to 25 minutes. The quartz crucible is solidified from the outside to the inside, so that the bubbles are fixed in the bubble layer.

[0087] like Figure 11 As shown, the quartz crucible melted by the crucible melting process disclosed in the embodiment of the present application has significantly fewer bubbles at the R corner position compared with the traditional melting process, thereby having a certain control effect on the bubbles at the R corner. Figure 12 As shown in the figure, the bubbles at the crucible mouth of the quartz crucible also have a certain improvement effect. Figure 11 and Figure 12 The left side in the middle is a quartz crucible melted by a traditional melting process, and the right side is a quartz crucible melted by the melting process in this application.

[0088] The terms "first," "second," and so on in the specification, claims, and drawings of this application are used to distinguish between different items, not to describe a specific order. Furthermore, the terms "including," "having," and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or elements is not limited to the listed steps or elements and may include steps or elements that are not listed.

[0089] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present application. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A crucible mold, characterized in that: include: A mold body (100), wherein the mold body (100) comprises a mold mouth (10), a straight wall section (20) and a mold bottom (30) connected in sequence, wherein the straight wall section (20) is provided with a plurality of vacuum air holes (21) for exhausting air, wherein the aperture of each vacuum air hole (21) is distributed in an increasing manner from the side of the straight wall section (20) close to the mold bottom (30) toward the side of the straight wall section (20) close to the mold mouth (10), and the spacing of each vacuum air hole (21) along the circumferential direction of the mold body (100) is distributed in an increasing manner from the side of the straight wall section (20) close to the mold bottom (30) toward the side of the straight wall section (20) close to the mold mouth (10).

2. The crucible mold according to claim 1, characterized in that One of the adjacent two of the mold mouth (10), the straight wall section (20) and the mold bottom (30) is provided with a first protrusion (40), and the other is provided with a first groove (50) that cooperates with the first protrusion (40).

3. The crucible mold according to claim 1, characterized in that The straight wall section (20) comprises an upper straight wall section (22), a middle straight wall section (23) and a lower straight wall section (24) which are connected in sequence, the upper straight wall section (22) being connected to the mold mouth (10), and the lower straight wall section (24) being connected to the mold bottom (30).

4. The crucible mold according to claim 3, characterized in that One of the adjacent two of the upper straight wall section (22), the middle straight wall section (23) and the lower straight wall section (24) is provided with a second protrusion (25), and the other is provided with a second groove (26) that cooperates with the second protrusion (25).

5. The crucible mold according to claim 3, characterized in that The aperture of each of the vacuum air holes (21) of the upper straight wall section (22) is larger than the aperture of each of the vacuum air holes (21) of the middle straight wall section (23); and / or, The aperture of each of the vacuum air holes (21) of the middle straight wall section (23) is larger than the aperture of each of the vacuum air holes (21) of the lower straight wall section (24).

6. The crucible mold according to claim 3, characterized in that The spacing between the vacuum air holes (21) of the upper straight wall section (22) along the circumferential direction of the mold body (100) is greater than the spacing between the vacuum air holes (21) of the middle straight wall section (23) along the circumferential direction of the mold body (100); and / or, The spacing between the vacuum air holes (21) of the middle straight wall section (23) along the circumferential direction of the mold body (100) is greater than the spacing between the vacuum air holes (21) of the lower straight wall section (24) along the circumferential direction of the mold body (100).

7. The crucible mold according to claim 3, characterized in that The heights of the upper straight wall section (22), the middle straight wall section (23) and the lower straight wall section (24) are all 100 mm to 200 mm; and / or, The aperture of the vacuum air hole (21) of the upper straight wall section (22) is 6 mm to 10 mm; and / or, The intervals between the vacuum air holes (21) of the upper straight wall section (22) and the circumferential direction of the mold body (100) are 7° to 10°; and / or, The diameter of the vacuum air hole (21) of the middle straight wall section (23) is 4 mm to 7 mm; and / or, The intervals between the vacuum air holes (21) of the middle straight wall section (23) along the circumferential direction of the mold body (100) are 3° to 5°; and / or, The aperture of the vacuum air hole (21) of the lower straight wall section (24) is 3 mm to 6 mm; and / or, The vacuum air holes (21) of the lower straight wall section (24) are spaced 2° to 4° along the circumferential direction of the mold body (100).

8. The crucible mold according to claim 1, characterized in that The height of the mold mouth (10) is 120 mm to 150 mm; and / or, The height of the straight wall section (20) is 60% to 80% of the height of the mold body (100); and / or, The height of the mold bottom (30) is 120 mm to 155 mm; and / or, The aperture of the vacuum air hole (21) is 3 mm to 10 mm.

9. The crucible mold according to any one of claims 1 to 8, characterized in that: The mold mouth (10), the straight wall section (20) and the mold bottom (30) all include a plurality of spliced connections along the circumferential direction of the mold body (100).

10. A crucible melting process, using the crucible mold according to any one of claims 1 to 9, characterized in that: Including steps: Melt the inner layer of quartz sand, set the arc power to 2000KW~5000KW and turn on the vacuum pump, and melt for 1min~3min; To initially form a transparent layer, reduce the arc power by 15% to 50%, and melt for 3 minutes to 15 minutes to initially form the transparent layer; Turn off the vacuum pump and melt for 7 to 10 minutes; Solidification molding: reduce the arc power by 15% to 30% and melt for 15 minutes to 25 minutes to allow the quartz crucible to solidify and form.

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