Tool for centering crucible and upper screen of single-crystal resistance furnace

Abstract

The utility model discloses a tool for centering a crucible and an upper screen of a single-crystal resistance furnace, and relates to the technical field of charging devices of single-crystal resistance furnaces, the crucible is placed in a heater, a heat preservation cylinder is arranged outside the heater, the upper screen is arranged at the top of the heat preservation cylinder, and a through hole is formed in the middle of the upper screen; a clamping mechanism is arranged at the top of the resistance furnace and is connected with a seed crystal; the tool comprises a first centering piece and a second centering piece, and the first centering piece is used for centering the crucible, so that the central axis of the crucible and the central axis of the heater are collinear; and the second centering piece is matched with the seed crystal for use and is used for centering the upper screen. Two limiting tools are adopted, a first centering piece is manufactured according to an ideal gap during design, and a seed crystal and a second centering piece are used in cooperation to center the heat preservation upper screen. According to the scheme, the use cost is low, the risk caused by misalignment of the crucible position to seeding is avoided, and the temperature uniformity of the melt is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of furnace loading devices for single crystal resistance furnaces, in particular to a tooling for centering a crucible and an upper screen of a single crystal resistance furnace. Background Art

[0002] In the existing resistance single crystal furnace, the traditional furnace loading method requires the crucible with raw materials to be placed on the pot holder by hand, and the distance between the outer edge of the crucible and the graphite heater is observed with the naked eye. The position of the crucible is adjusted before seeding so that the crucible is located in the middle of the graphite heater. Finally, an annular insulation upper screen is placed on the crucible, and the hole in the middle of the annular insulation upper screen for blank pulling is ensured to be coaxial with the crucible. After the positions of the crucible and the annular insulation upper screen are adjusted, the seed crystal is sunk so that the growth end of the seed crystal is aligned with the center of the crucible, and the seed crystal does not contact the raw materials in the crucible. Then the crucible is heated by the graphite heater to liquefy the material in the crucible. Both the graphite heater and the crucible are cylindrical structures, and the graphite heater heats the crucible in an annular manner. There is a radial problem gradient in the crucible, and the melt in the crucible has natural convection that is deposited from the periphery to the center. At this time, the seed crystal is in the center of the melt, and with the assistance of appropriate pulling, rotation speed, and cooling rate, a crystal can be grown on the seed crystal.

[0003] However, it is impossible to accurately determine whether the crucible is placed in the center of the graphite heater by naked eye observation. When the crucible is heated unevenly, the position of the lowest temperature point in the center will shift, and the seeding point (the growth end of the seed crystal) during seeding should be aligned with the lowest temperature point in the center of the crucible. In this case, if the crucible is not in the center of the graphite heater, the growth end of the seed crystal will be misaligned with the lowest temperature point in the center of the crucible, which will affect the seeding and cause the seeded crystal to be skewed or even unable to be seeded. In more serious cases, the pot support supporting the crucible below is a movable structure, which needs to be leveled before use. The shift of the center of gravity of the crucible under high temperature deformation may even cause the crucible to contact the heater, which in turn causes ignition and damage to the temperature field or even the furnace body. Since the temperature field side screens for insulating the crucible will deform with use, and the upper screen is designed with a margin, it is impossible to accurately adjust the position of the upper screen by naked eye during installation so that the central axis of the circular hole in the middle of the upper screen is colinear (coaxial) with the central axis of the crucible. The uneven placement of the upper insulation material will also affect the temperature uniformity of the melt, thereby affecting the quality of the grown crystals.

[0004] Therefore, a tool for centering a crucible and an upper screen of a single crystal resistance furnace is proposed. Utility Model Content

[0005] The utility model aims to overcome the shortcomings of the prior art and provide a tool for centering a crucible and an upper screen of a single crystal resistance furnace.

[0006] The purpose of this utility model is achieved through the following technical solutions:

[0007] A tool for centering a crucible and an upper screen of a single crystal resistance furnace, wherein the crucible with a cylindrical structure is placed in a heater with a cylindrical structure.

[0008] An insulation cylinder is arranged on the outside of the heater, an upper screen for insulation is arranged on the top of the insulation cylinder, and a through hole is opened in the middle of the upper screen; a clamping mechanism is arranged on the top of the resistance furnace, and a seed crystal is connected to the clamping mechanism; the tooling comprises a first centering piece and a second centering piece, the first centering piece is used for centering the crucible, so that the central axis of the crucible is collinear with the central axis of the heater; the second centering piece is used in conjunction with the seed crystal, and is used for centering the upper screen, so that the central axis of the through hole is collinear with the central axis of the crucible.

[0009] Furthermore, in the utility model, the first centering piece is a circular ring structure, and a circular groove is provided at one end of the first centering piece. The inner diameter of the circular groove is the same as the outer diameter of the crucible and is larger than the inner diameter of the first centering piece; the outer diameter of the first centering piece is the same as the inner diameter of the heater.

[0010] Furthermore, in the utility model, the second centering member includes a base plate, a first cylinder and a second cylinder stacked in sequence from top to bottom, the base plate is a cylindrical structure, and a centering countersunk hole is provided in the middle of the side wall of the base plate away from the first cylinder; the central axis of the second cylinder is colinear with the central axis of the base plate, and the diameter of the second cylinder is the same as the diameter of the through hole.

[0011] Furthermore, in the present invention, the diameter of the first cylinder is smaller than the diameter of the bottom plate, and larger than the diameter of the second cylinder.

[0012] The beneficial effects of the utility model are:

[0013] The utility model provides a tooling for centering the crucible and the upper screen of a single crystal resistance furnace, which adopts two limiter tools, a crucible centering ring (i.e., the first centering piece) made according to the ideal gap during design, and the cooperation of the seed crystal and the second centering piece to center the heat-insulating upper screen. The solution has low cost, avoids the risk of seeding due to the misalignment of the crucible position, improves the temperature uniformity of the melt, avoids the error caused by human factors, and increases the stability and repeatability of the process. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of a resistance furnace according to an embodiment of the utility model;

[0015] Figure 2This is a schematic structural diagram of a first centering member according to an embodiment of the utility model;

[0016] Figure 3 This is a schematic structural diagram of a second centering member according to an embodiment of the utility model;

[0017] Figure 4 This is a schematic structural diagram of the crucible and the upper screen after alignment in an embodiment of the utility model;

[0018] Figure 5 This is a structural schematic diagram of the crucible centering of an embodiment of the utility model;

[0019] Figure 6 This is a schematic diagram of the structure of the upper screen centering of an embodiment of the utility model;

[0020] Figure 7 It is a structural schematic diagram of the upper screen centering of an embodiment of the utility model.

[0021] In the figure: 101-resistance furnace; 201-crucible; 301-heater; 401-insulation cylinder; 501-first centering piece; 502-circular groove; 601-bottom plate; 602-first cylinder; 603-second cylinder; 604-centering countersunk hole; 701-upper screen; 702-upper second screen; 703-upper third screen; 704-through hole; 801-seed crystal; 901-pot support. DETAILED DESCRIPTION

[0022] The following will be combined with the embodiments to clearly and completely describe the technical solution of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.

[0023] See also Figure 1-7 , the utility model provides a technical solution:

[0024] A tool for centering a crucible and an upper screen of a single crystal resistance furnace, wherein a crucible 201 of a cylindrical structure is placed in a heater 301 of a cylindrical structure. An insulation cylinder 401 is arranged outside the heater 301, wherein the insulation cylinder 401 includes a graphite side barrel and an insulation molybdenum side barrel, and the graphite side barrel is located inside the insulation molybdenum side barrel. An upper screen for heat preservation is arranged on the top of the insulation cylinder 401, and a through hole 704 is opened in the middle of the upper screen; a clamping mechanism is arranged on the top of the resistance furnace 101, and a seed crystal 801 is connected to the clamping mechanism; the tool comprises a first centering piece 501 and a second centering piece, wherein the first centering piece 501 is used for centering the crucible 201, so that the central axis of the crucible 201 is collinear with the central axis of the heater 301; and the second centering piece is used in conjunction with the seed crystal 801, and is used for centering the upper screen, so that the central axis of the through hole 704 is collinear with the central axis of the crucible 201.

[0025] Specifically, the first centering piece 501 is a circular ring structure, and a circular groove 502 is opened at one end of the first centering piece 501. The inner diameter of the circular groove 502 is the same as the outer diameter of the crucible 201 and is larger than the inner diameter of the first centering piece 501; the outer diameter of the first centering piece 501 is the same as the inner diameter of the heater 301.

[0026] Specifically, the second centering member includes a base plate 601, a first cylinder 602 and a second cylinder 603 stacked in sequence from top to bottom. The base plate 601 is a cylindrical structure, and a centering countersunk hole 604 is opened in the middle of the side wall of the base plate 601 away from the first cylinder 602; the central axis of the second cylinder 603 is colinear with the central axis of the base plate 601, and the diameter of the second cylinder 603 is the same as the diameter of the through hole 704.

[0027] In some implementations of this embodiment, the diameter of the first cylinder 602 is smaller than the diameter of the bottom plate 601 and larger than the diameter of the second cylinder 603 .

[0028] In this embodiment, the top of the heat preservation tube 401 is designed with a stepped step, and the upper screen is divided into an upper screen 701, an upper second screen 702, and an upper third screen 703. The three screens are sequentially placed from bottom to top on the corresponding steps on the top of the heat preservation tube 401. A through hole 704 is designed in the middle of the three screens.

[0029] Alignment steps:

[0030] S1. First, install the heater 301 and the insulation tube 401 in the resistance furnace 101, and make the heater 301 located in the insulation tube 401. A pot support 901 is installed in the heater 301, and the pot support 901 is located in the middle of the heater 301. Then, place the crucible 201 on the pot support 901.

[0031] S2, such as Figure 5As shown, the first centering piece 501 is clamped on the top of the crucible 201, and the upper part of the crucible 201 is gradually clamped into the circular groove 502. In the process of the first centering piece 501 being clamped into the crucible 201, the radial displacement of the crucible 201 in the horizontal direction on the pot holder 901 is adjusted. When the top of the crucible 201 is completely clamped into the circular groove 502, the distance between the outer wall of the crucible 201 and the inner wall of the heater 301 is equal everywhere, and the crucible 201 is located in the center of the heater 301. After the centering adjustment of the crucible 201 is completed, the first centering piece 501 is taken out.

[0032] S3. The top of the resistance furnace 101 is designed with a seed crystal 801 clamping mechanism, which can adjust the spatial position of the seed crystal 801. Figure 6 As shown, when centering the upper screen 701, the position of the seed crystal 801 is first controlled by the clamping mechanism, and the upper screen 701 is first placed on the corresponding step at the top of the heat preservation cylinder 401, and then the second centering piece is placed in the middle through hole of the upper screen 701, and then the seed crystal 801 is sunk, so that the free end of the seed crystal 801 is inserted into the centering countersunk hole 604 of the second centering piece, and the position of the upper screen 701 is adjusted so that the seed crystal corresponds to the middle through hole of the upper screen 701. When the horizontal displacement of the upper screen 701 is adjusted, the central axis of the middle through hole 704 of the upper screen 701 is now collinear with the central axis of the seed crystal 801. Then the clamping mechanism is operated to raise the seed crystal 801, and the second centering piece is taken out.

[0033] S4, such as Figure 7 As shown, referring to step S3, the centering method for the upper second screen 702 and the upper third screen 703 is the same as the centering method for the upper screen 701.

[0034] S5, after the crucible 201, the upper screen 701, the upper second screen 702 and the upper third screen 703 are all aligned, operate the clamping mechanism to move the seed crystal 801 downward and extend it into the crucible 201 through the through hole 704, and then start the heater 301 to heat the crucible 201 to liquefy the raw material in the crucible 201, and the liquefied raw material can grow on the seed crystal 801.

[0035] The above is only a preferred embodiment of the utility model. It should be understood that the utility model is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art do not deviate from the spirit and scope of the utility model, and should be within the scope of protection of the claims attached to the utility model.

Claims

1. A tool for aligning a crucible and an upper screen of a single crystal resistance furnace, wherein a crucible (201) having a cylindrical structure is placed in a heater (301) having a cylindrical structure, a heat preservation cylinder (401) is arranged outside the heater (301), an upper screen for heat preservation is arranged on the top of the heat preservation cylinder (401), and a through hole (704) is opened in the middle of the upper screen; a clamping mechanism is arranged on the top of the resistance furnace (101), and a seed crystal (801) is connected to the clamping mechanism, characterized in that: The tooling comprises a first centering piece (501) and a second centering piece, wherein the first centering piece (501) is used for centering the crucible (201) so that the central axis of the crucible (201) is collinear with the central axis of the heater (301); and the second centering piece is used in conjunction with the seed crystal (801) and is used for centering the upper screen so that the central axis of the through hole (704) is collinear with the central axis of the crucible (201).

2. The tooling for centering the crucible and the upper screen of a single crystal resistance furnace according to claim 1, characterized in that: The first centering piece (501) is a circular ring structure, and a circular groove (502) is provided at one end of the first centering piece (501); the inner diameter of the circular groove (502) is the same as the outer diameter of the crucible (201) and is larger than the inner diameter of the first centering piece (501); the outer diameter of the first centering piece (501) is the same as the inner diameter of the heater (301).

3. The tooling for centering the crucible and the upper screen of a single crystal resistance furnace according to claim 1, characterized in that: The second centering member comprises a base plate (601), a first cylinder (602) and a second cylinder (603) which are stacked in sequence from top to bottom; the base plate (601) is a cylindrical structure; a centering countersunk hole (604) is provided in the middle of a side wall of the base plate (601) away from the first cylinder (602); the central axis of the second cylinder (603) is colinear with the central axis of the base plate (601); and the diameter of the second cylinder (603) is the same as the diameter of the through hole (704).

4. The tooling for centering the crucible and the upper screen of a single crystal resistance furnace according to claim 3, characterized in that: The diameter of the first cylinder (602) is smaller than the diameter of the bottom plate (601), and larger than the diameter of the second cylinder (603).

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