A single crystal furnace with a height-adjustable heating screen

Abstract

This utility model discloses a liftable heat shield for a single-crystal furnace, comprising a single-crystal furnace body. A guide cylinder is fixedly connected to the interior of the furnace body near the top. Support rods are fixedly connected to the four corners of the outer wall of the support base, with the other end of each support rod fixedly connected to the inner wall of the furnace body. An annular cavity is opened at the bottom of the furnace body, and a support base is fixedly connected to the bottom of this cavity. This allows the heat shield to be raised and lowered into and out of the furnace chamber through this opening. The heat shield is no longer fixed at a certain height on the inner wall of the furnace chamber, but is connected via hydraulic drive and a detachable structure. This connection method allows for the disassembly and fixing of the heat shield, facilitating quick replacement of different types or damaged heat shields during maintenance. Maintenance can be performed without opening the furnace door or disassembling complex internal structures; the heat shield can simply be moved out through the bottom opening and the lifting structure, improving safety and shortening heat shield replacement time.

Description

Technical Field

[0001] This utility model relates to the field of single crystal furnace technology, specifically to a single crystal furnace with a height-adjustable heating screen. Background Technology

[0002] A single-crystal furnace thermal shield, also called a thermal field shield, is typically a ring-shaped or cylindrical structure made of multiple layers of high-temperature resistant material, installed above the crucible and around the crystal growth area of ​​the single-crystal furnace. During single-crystal silicon growth, precise control of the temperature gradient and distribution within the crystal growth area is crucial. The thermal shield effectively prevents the molten silicon and the large amount of heat radiation generated by the heater from being directly transferred upwards to the growing crystal, reducing heat loss and concentrating more heat at the melt-crystal interface, thus providing a stable thermal environment for crystal growth.

[0003] Although the heating screen itself does not directly contact the molten silicon or the growing crystal, it is subjected to intense thermal cycling at temperatures typically exceeding 1000 degrees Celsius within a single-crystal furnace due to prolonged exposure to high temperatures. This repeated heating and cooling process subjects the heating screen to enormous thermal stress. Prolonged thermal expansion and contraction can easily lead to micro-cracks in the material, which may eventually develop into macro-cracks or deformation.

[0004] One of the main functions of a heating screen is to regulate thermal radiation and temperature gradient. If the heating screen is damaged, such as by cracks or deformation, its heat reflection or insulation capabilities will decrease, resulting in uneven temperature distribution at the crystal growth interface. Therefore, we propose a heating screen with adjustable height for a single crystal furnace. Utility Model Content

[0005] The purpose of this invention is to provide a height-adjustable heating screen for a single crystal furnace to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a liftable heating screen for a single crystal furnace, comprising a single crystal furnace body, a flow guide tube fixedly connected to the interior of the single crystal furnace body near the top, an arc-shaped extension at the bottom of the flow guide tube, a crucible positioned directly below the arc-shaped extension of the flow guide tube, and a gap between the outer wall of the flow guide tube and the inner wall of the crucible, a support being fitted onto the outer wall of the crucible, support rods being fixedly connected to the four corners of the outer wall of the support, and the other end of the support rods being fixedly connected to the inner wall of the single crystal furnace body, an annular cavity being opened at the bottom of the single crystal furnace body, and a support base being fixedly connected to the bottom of the annular cavity of the single crystal furnace body.

[0007] Preferably, the bottom of the support is fixedly connected to a pre-embedded base, and the pre-embedded base is a pre-embedded component. A lifting structure is provided at the center of the pre-embedded base. The center of the lifting structure penetrates through the support base, and the top of the lifting structure is sleeved on the outer wall of the support.

[0008] Preferably, the lifting structure includes a hydraulic cylinder, the bottom of which is fixedly connected to the center of the surface of the pre-embedded base. The center of the hydraulic cylinder penetrates the bottom of the pre-embedded base and is clearance-fitted. A threaded seat is fixedly connected to the upper end of the hydraulic cylinder. A threaded post is threadedly connected to the inner cavity of the threaded seat. A stop is fixedly connected to the side wall of the threaded post, and the lower surface of the stop is in contact with the upper surface of the threaded seat. A hot screen seat is fixedly connected to the upper end of the threaded post. The outer ring wall of the hot screen seat is in contact with the upper surface of the support base. A hot screen is fixedly connected to the center of the upper surface of the hot screen seat and extends into the inner cavity of the single crystal furnace body. The inner cavity of the hot screen is sleeved with the outer wall of the crucible.

[0009] Preferably, the lower surface of the threaded seat is symmetrically fixedly connected with guide rods, and the outer wall of the guide rods is sleeved with the surface of the support base near the bottom, and the fit is clearance fit.

[0010] Compared with the prior art, the beneficial effects of this utility model are as follows: When using a single crystal furnace, the furnace body is modified to have an annular opening at the bottom. An annular, closable opening is made at the bottom of the furnace body. This opening is normally closed when the hot screen rises and only opens when a descent is required. The size and position of the opening are designed so that the hot screen can be raised and lowered into and out of the furnace chamber through this opening. The hot screen is no longer fixed at a certain height on the inner wall of the furnace chamber, but is connected by hydraulic drive and a detachable structure. This connection method allows the hot screen to be disassembled and fixed, facilitating the quick replacement of different types or damaged hot screens during maintenance. There is no need to open the furnace door or disassemble the complex structure inside the furnace. Maintenance can be carried out simply by moving the hot screen out through the bottom opening and the lifting structure, which improves safety and shortens the hot screen replacement time. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 for Figure 1 Detailed diagram of the lifting structure; Figure 3 for Figure 1 Detailed image of the single crystal furnace body; In the diagram: 1. Single crystal furnace body; 2. Flow guide tube; 3. Support rod; 4. Support base; 5. Crucible; 6. Lifting structure; 61. Hydraulic cylinder; 62. Threaded seat; 63. Threaded column; 64. Stop block; 65. Hot screen seat; 66. Hot screen; 67. Guide rod; 7. Support base; 8. Embedded base. Detailed Implementation

[0012] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0013] Please see Figure 1-3 This utility model provides a liftable heating screen for a single crystal furnace, including a single crystal furnace body 1. A guide cylinder 2 is fixedly connected to the inside of the single crystal furnace body 1 near the top. The bottom of the guide cylinder 2 is provided with an arc-shaped extension. A crucible 5 is provided directly below the arc-shaped extension of the guide cylinder 2. There is a gap between the outer wall of the guide cylinder 2 and the inner wall of the crucible 5. A support 4 is sleeved on the outer wall of the crucible 5. Support rods 3 are fixedly connected to the four corners of the outer wall of the support 4. The other end of the support rods 3 is fixedly connected to the inner wall of the single crystal furnace body 1. An annular cavity is opened at the bottom of the single crystal furnace body 1. A support base 7 is fixedly connected to the bottom of the annular cavity of the single crystal furnace body 1.

[0014] This device is used in the maintenance of single crystal furnaces. The replacement of the heat exchanger 66 is accomplished by setting up a lifting structure 6. A support 4 is set inside the single crystal furnace body 1. The four outer corners of the support 4 are fixed inside the single crystal furnace body 1 by support rods 3. The support 4 is used to support the crucible 5 and keep it in the center of the furnace body. The crucible 5 is the core container in the single crystal furnace used to hold and heat the polycrystalline silicon raw material, so that it melts and forms silicon melt. At the same time, the guide tube 2 ensures that the material accurately enters the interior of the crucible 5.

[0015] A pre-embedded base 8 is fixedly connected to the bottom of the support 7, and the pre-embedded base 8 is a pre-embedded part. A lifting structure 6 is set at the center of the pre-embedded base 8. The center of the lifting structure 6 penetrates the support base 7, and the top of the lifting structure 6 is sleeved on the outer wall of the support 4. The support base 7 is set at the bottom of the single crystal furnace body 1 for support. At the same time, a cement groove is opened at the bottom of the support base 7 so that the pre-embedded base 8 is placed in it. The lifting structure 6 is set on the surface of the pre-embedded base 8. The lifting structure 6 can control the heat screen 66 to be sleeved on the outside of the support 4 to reduce heat radiation loss. By reflecting or blocking the downward heat radiation of molten silicon and crystal growth area, it improves the heat energy utilization efficiency, controls the temperature distribution at the crystal growth interface, and helps to form more uniform single crystal silicon with fewer defects. It also has a lifting function and can replace the heat screen 66.

[0016] The lifting structure 6 includes a hydraulic cylinder 61. The bottom of the hydraulic cylinder 61 is fixedly connected to the center of the surface of the embedded base 8. The center of the hydraulic cylinder 61 penetrates the bottom of the embedded base 8 and is clearance-fitted. A threaded seat 62 is fixedly connected to the upper end of the hydraulic cylinder 61. A threaded post 63 is threadedly connected to the inner cavity of the threaded seat 62. A stop 64 is fixedly connected to the side wall of the threaded post 63, and the lower surface of the stop 64 is in contact with the upper surface of the threaded seat 62. A heated screen seat 65 is fixedly connected to the upper end of the threaded post 63. The outer ring wall of the heated screen seat 65 is in contact with the upper surface of the support base 7. A heated screen 66 is fixedly connected to the center of the upper surface of the heated screen seat 65 and extends to the single crystal furnace body 1. The inner cavity of the hot screen 66 is fitted with the outer wall of the crucible 5. The lifting structure 6 is used as follows: the lifting structure 6 is driven by a hydraulic cylinder 61. The hydraulic cylinder 61 pushes the threaded seat 62 to move up and down between the support base 7. At the same time, the threaded column 63 is threadedly connected inside. The hot screen seat 65 can fit with the threaded seat 62 through the threaded column 63. The two are threadedly connected by rotation, thereby realizing the installation and disassembly functions. Through the opening at the bottom of the single crystal furnace body 1, the hot screen 66 can be lifted and lowered into and out of the furnace chamber through this opening. The hot screen is no longer fixed at a certain height on the inner wall of the furnace chamber, which facilitates the quick replacement of different types or damaged hot screens during maintenance without opening the furnace door or disassembling the complex structure inside the furnace.

[0017] Guide rods 67 are symmetrically fixedly connected to the lower surface of the threaded seat 62. The outer wall of the guide rod 67 is sleeved with the surface of the support base 7 near the bottom and is clearance fit. The guide rods 67 are symmetrically arranged at the bottom of the threaded seat 62. The guide rods 67 can slide on the surface of the support base 7 to provide guidance and assist sliding.

[0018] Working Principle: This device is used in the maintenance of single crystal furnaces. A lifting structure 6 is used to replace the heat exchanger 66. A support 4 is installed inside the single crystal furnace body 1, with its four outer corners fixed to the furnace body 1 by support rods 3. The support 4 supports the crucible 5 and keeps it in the center of the furnace body. The crucible 5 is the core container in the single crystal furnace used to hold and heat polycrystalline silicon raw materials, melting them to form molten silicon. A guide tube 2 ensures accurate material entry into the crucible 5. A support base 7 is installed at the bottom of the single crystal furnace body 1 for support. A cement trough is opened at the bottom of the support base 7 to house a pre-embedded base 8. A lifting structure 6 is installed on the surface of the pre-embedded base 8. The lifting structure 6 controls the heat exchanger 66 to fit over the support 4, reducing heat radiation loss. By reflecting or blocking the downward heat radiation from the molten silicon and crystal growth area, it improves thermal efficiency and controls crystal growth. The temperature distribution at the interface helps to form more uniform monocrystalline silicon with fewer defects. It also has a lifting function and can replace the heat screen 66. The lifting structure 6 is used as follows: the lifting structure 6 is driven by a hydraulic cylinder 61. The hydraulic cylinder 61 pushes the threaded seat 62 to rise and fall between the support base 7. Guide rods 67 are symmetrically arranged at the bottom of the threaded seat 62. The guide rods 67 can be placed on the surface of the support base 7 to provide guidance and assist sliding. At the same time, a threaded post 63 can be threadedly connected inside. The heat screen 65 can fit with the threaded seat 62 through the threaded post 63. The two are threadedly connected by rotation, thereby realizing the installation and disassembly function. Through the opening at the bottom of the monocrystalline furnace body 1, the heat screen 66 can be lifted and lowered into and out of the furnace chamber through this opening. The heat screen is no longer fixed at a certain height on the inner wall of the furnace chamber, which facilitates the quick replacement of different types or damaged heat screens during maintenance without opening the furnace door or disassembling the complex structure inside the furnace.

[0019] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A height-adjustable heating screen for a single crystal furnace, characterized in that: The single crystal furnace body (1) includes a flow guide tube (2) fixedly connected to the inside of the single crystal furnace body (1) near the top. The bottom of the flow guide tube (2) is provided with an arc-shaped extension. A crucible (5) is provided directly below the arc-shaped extension of the flow guide tube (2). The outer wall of the flow guide tube (2) and the inner wall of the crucible (5) have a gap. A support (4) is sleeved on the outer wall of the crucible (5). Support rods (3) are fixedly connected to the four corners of the outer wall of the support (4). The other end of the support rods (3) is fixedly connected to the inner wall of the single crystal furnace body (1). An annular cavity is opened at the bottom of the single crystal furnace body (1). A support base (7) is fixedly connected to the bottom of the annular cavity of the single crystal furnace body (1).

2. The single crystal furnace with a height-adjustable heating screen according to claim 1, characterized in that: The bottom of the support (7) is fixedly connected to a pre-embedded base (8), and the pre-embedded base (8) is a pre-embedded part. A lifting structure (6) is provided at the center of the pre-embedded base (8). The center of the lifting structure (6) penetrates the support base (7), and the top of the lifting structure (6) is sleeved on the outer wall of the support (4).

3. The single crystal furnace with a height-adjustable heating screen according to claim 1, characterized in that: The lifting structure (6) includes a hydraulic cylinder (61). The bottom of the hydraulic cylinder (61) is fixedly connected to the center of the surface of the embedded base (8). The center of the hydraulic cylinder (61) penetrates the bottom of the embedded base (8) and is clearance-fitted. A threaded seat (62) is fixedly connected to the upper end of the hydraulic cylinder (61). A threaded post (63) is threadedly connected to the inner cavity of the threaded seat (62). A stop block (64) is fixedly connected to the side wall of the threaded post (63). The lower surface of the stop block (64) is in contact with the upper surface of the threaded seat (62). The upper end of the threaded column (63) is fixedly connected to a hot screen seat (65). The outer ring wall of the hot screen seat (65) is in contact with the upper surface of the support base (7). A hot screen (66) is fixedly connected to the center of the upper surface of the hot screen seat (65). The hot screen (66) extends into the inner cavity of the single crystal furnace body (1). The inner cavity of the hot screen (66) is fitted with the outer wall of the crucible (5).

4. The single crystal furnace with a height-adjustable heating screen according to claim 1, characterized in that: The lower surface of the threaded seat (62) is symmetrically fixedly connected with a guide rod (67). The outer wall of the guide rod (67) is sleeved with the surface of the support base (7) near the bottom, and the fit is clearance fit.

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