Device for growing large-size sapphire plate by edge-defined film-fed growth method

Abstract

The invention discloses a device for growing a large-size sapphire plate through an edge-defined film-fed growth method. The device comprises a growth furnace, a heating and heat preservation system, a crucible system, a lifting mechanism, a rotating mechanism and a lifting mechanism. The growth furnace is divided into an upper furnace chamber and a lower furnace chamber which are independently heated in a partitioned mode, a heat shield is arranged between the upper furnace chamber, the crucible body is arranged on the crucible tray and arranged in the lower furnace chamber, a lifting mechanism and a rotating mechanism are arranged on the lower side of the crucible tray, a mold is arranged in the crucible body, and the mold is connected with a lifting mechanism through a lifting rod. The upper furnace chamber and the lower furnace chamber are designed, the temperature gradient is independently controlled in a partitioned mode, and high-speed growth of plates is achieved. Meanwhile, effective release of thermal stress in the plate is ensured, wafer fragmentation is prevented, the growth efficiency of crystals is improved, high-quality growth of the large-size sapphire plate is achieved, and the problems that in the prior art, thermal stress in the plate is difficult to effectively release, and the growth quality of the crystals is not high are solved; and a new possibility is provided for the application of the sapphire single crystal in the military and civil fields.

Description

Technical Field

[0001] This invention relates to the field of sapphire growth technology, and more specifically, to an apparatus for growing large-size sapphire sheets using a guided mold method. Background Technology

[0002] With the rapid development of dual-use optoelectronic / infrared systems for both military and civilian applications, the demand for large-area optoelectronic window materials is becoming increasingly urgent, especially regarding the performance of these materials, where the requirements for high hardness, high strength, wide wavelength range, and high transmittance are becoming increasingly stringent. Sapphire single crystal, as an excellent wide-wavelength transparent material, exhibits good transmittance in the ultraviolet, visible, infrared, and microwave bands, meeting the requirements of multi-mode composite guidance. Simultaneously, sapphire single crystal possesses excellent mechanical properties, chemical stability, and high-temperature resistance; it has high strength and hardness, and can operate in harsh environments approaching 2000°C. Therefore, sapphire single crystal is the optimal optoelectronic window material.

[0003] However, China currently lacks domestic technology for growing large-size, high-quality sapphire sheets using the guided-mold method, which cannot meet the needs of large-scale production. Existing crystal growth methods are either unable to produce large-size sapphire sheets in terms of size or quality, and are also costly. During cutting, it is difficult to find plate-shaped regions that meet the requirements for strength and transmittance. Furthermore, traditional equipment cannot simultaneously produce large-size sheets with a width greater than 500mm and a thickness exceeding 30mm, limiting the further application of sapphire single crystals.

[0004] To address these issues, a new guided-mold method is needed to grow large-size sapphire substrates, enabling the growth of large-size substrate crystals. Summary of the Invention

[0005] The technical problem this invention aims to solve is to provide an apparatus for growing large-size sapphire substrates using a guided-mode method. By independently controlling the temperature gradient in different zones, it ensures a wider and thicker solid-liquid interface for wafer growth, as well as high-quality and high-speed crystal growth at different stages. This effectively prevents wafer breakage, improves crystal growth quality, and simultaneously ensures effective release of internal thermal stress, further preventing wafer breakage and increasing crystal growth efficiency. This apparatus facilitates the fabrication of large-size substrates with widths greater than 500 mm and thicknesses exceeding 30 mm, meeting the application requirements of large-size special optical windows and providing new possibilities for the application of sapphire single crystals in military and civilian fields.

[0006] This invention provides an apparatus for growing large-size sapphire plates using a guided mold method, comprising a growth furnace, a heating and insulation system, a crucible system, a lifting mechanism, a rotating mechanism, and a pulling mechanism, wherein: The growth furnace includes a frame base, a lower furnace chamber on the upper side of the frame base, an upper furnace chamber on the upper side of the lower furnace chamber, a partition plate at the connection between the upper furnace chamber and the lower furnace chamber, a frame base opening at the center of the frame base, and a partition plate opening at the center of the partition plate. The heating and insulation system includes an upper insulation layer in the upper furnace chamber and a lower insulation layer in the lower furnace chamber. The upper insulation layer is equipped with an upper furnace chamber heater, and the lower insulation layer is equipped with a lower furnace chamber heater. A heat shield is installed in the opening of the partition plate, and a heat conduction hole is provided at the bottom of the heat shield. The upper furnace chamber heater and the lower furnace chamber heater are both installed on the side wall of the growth furnace by fixing bolts. The crucible system includes a crucible body, which is placed on a crucible tray, which is located in the lower furnace chamber and below the heat shield. The lifting mechanism includes a motor support installed on the lower side of the opening in the frame base. A lifting ball screw and a lifting guide rod are vertically arranged inside the motor support. A lifting servo motor is installed on the lower side of the motor support. The power output end of the lifting servo motor is connected to the lifting ball screw. A lifting nut connecting plate is movably mounted on the lifting guide rod. A lifting nut is provided on the lifting nut connecting plate. The upper thread of the lifting ball screw is fitted into the lifting nut. The rotating mechanism includes a rotating mechanism mounting plate located on the upper side of the frame base. The rotating mechanism mounting plate is fixedly connected to the lifting screw nut connecting plate. A rotating servo motor and a worm gear support are mounted on the upper side of the rotating mechanism mounting plate. The rotating servo motor and the worm gear support are located on both sides of the opening in the frame base. The power output end of the rotating servo motor is connected to the rotating worm. The other end of the rotating worm is rotatably mounted on the worm gear support. The middle part of the rotating worm meshes with a rotating turbine. The rotating turbine is fixedly mounted on the support rod. The crucible tray is installed on the upper end of the support rod. The lifting mechanism includes a lifting support frame, a lifting servo motor mounted on the top of the lifting support frame, a lifting ball screw and a lifting guide rail inside the support frame, a lifting nut mounting plate movably mounted on the lifting guide rail, a lifting rod mounting seat and a lifting ball screw nut mounted on the lifting nut mounting plate, a lifting rod mounted on the lifting rod mounting seat, and a lifting ball screw nut threaded onto the lifting ball screw. The upper end of the lifting ball screw is connected to the power output end of the lifting servo motor, and the lower end of the lifting rod is connected to the mold, which is located inside the crucible body.

[0007] Preferably, the lower part of the lifting support frame is provided with a guide sleeve, and the lifting rod is movably fitted inside the guide sleeve.

[0008] Preferably, it also includes a feeding mechanism, which includes a feeding pipe, a hopper, an air pump, and a temperature sensor. The feeding pipe is located above the material dropping buffer mechanism and includes an inner pipe and an outer insulation material. The inner pipe is made of tungsten, molybdenum, or graphite material, and the outer insulation material is made of graphite soft felt or graphite hard felt. The hopper is located at one end of the feeding pipe, the air pump is located on the feeding pipe, and the temperature sensor is located inside the feeding pipe.

[0009] Preferably, the material feeding buffer mechanism is located at the center of the crucible body and includes a kinetic energy absorbing material and a buffer container. The kinetic energy absorbing material is made of molybdenum wire and tungsten wire through three-dimensional weaving, and the diameter of the molybdenum wire and tungsten wire is 0.2-2mm.

[0010] Preferably, the system further includes a control system, which includes a temperature controller, a gas flow controller, and a growth controller. The temperature controller is electrically connected to the upper furnace chamber heater and the lower furnace chamber heater. The gas flow controller is electrically connected to the air pump. The growth controller is electrically connected to the lifting servo motor, the rotating servo motor, and the pulling servo motor.

[0011] Preferably, both the upper furnace chamber heater and the lower furnace chamber heater are composed of plate-shaped graphite resistance heaters, which are made of high-purity graphite material and coated with a high-temperature ceramic coating.

[0012] Preferably, both the upper and lower insulation layers are made of high-purity graphite soft felt or graphite hard felt, with a thickness of 50-100mm.

[0013] Preferably, the crucible body is made of high-purity molybdenum material.

[0014] Preferably, the heat shield is a groove with an inverted trapezoidal cross-section.

[0015] The beneficial effects of the present invention are as follows: 1. The apparatus for growing large-size sapphire plates using the guide mold method of the present invention is to set the growth furnace into upper and lower furnace chambers, and to set up a heat insulation layer and a heater in each chamber respectively. The temperature gradient is controlled independently in each zone to form different temperature zones. An inclined heat screen is set between the upper and lower temperature zones. The temperature gradient at the solid-liquid interface is adjusted by the heat screen, and finally three temperature zones are formed, namely, the low temperature zone in the upper furnace chamber, the medium temperature zone in the heat screen, and the high temperature zone in the lower furnace chamber. 1. By controlling the temperature gradient, a wider and thicker solid-liquid interface is ensured for the growth of wafers, as well as high-quality and high-speed crystal growth at different stages. This effectively prevents wafer breakage, improves crystal growth quality, and overcomes the limitation of traditional devices that cannot simultaneously grow large-size plates with a width greater than 500mm and a thickness greater than 30mm, thus expanding the application range of sapphire single crystals. 2. A lifting mechanism is installed at the bottom of the crucible body, which can drive the crucible body to rise and fall during crystal growth, ensuring continuous contact between the liquid material inside the crucible and the crystal. This avoids insufficient solution height inside the crucible in the later stages of crystal growth, resulting in insufficient capillary pressure, crystal failure, or waste due to excessive residual material, thereby improving crystal growth efficiency. 3. A rotating mechanism is installed at the bottom of the crucible body, which improves the flow of the solution inside the crucible, eliminates bubbles at the solid-liquid interface, ensures the production of high-quality crystals, and increases the capillary effect of a wider and thicker growth interface, improving the growth momentum in the later stages of crystal growth.

[0016] In summary, the technical solution of this invention, through the design of upper and lower insulation zones and heating zones, allows for independent control of the temperature gradient in each zone, enabling high-speed growth of the sapphire substrate. Simultaneously, it ensures the effective release of internal thermal stress within the substrate to prevent wafer breakage and improve crystal growth efficiency. This achieves high-quality growth of large-size sapphire substrates, solving problems such as the difficulty in effectively releasing internal thermal stress and low crystal growth quality in existing technologies. This provides new possibilities for the application of sapphire single crystals in both military and civilian fields. Attached Figure Description

[0017] Figure 1 This is a top view of the apparatus for growing large-size sapphire plates using the guided mold method of the present invention; Figure 2 for Figure 1 A sectional view along the center CC; Figure 3 for Figure 1 A sectional view along the middle edge BB; Figure 4 for Figure 3 Enlarged view of the lifting and rotating mechanisms; Figure 5 for Figure 3 A magnified view of a portion of the lifting mechanism.

[0018] In the diagram: Growth furnace 1, frame base 11, lower furnace chamber 12, upper furnace chamber 13, partition plate 14, frame base opening 15, partition plate opening 16; Heating and insulation system 2, upper insulation layer 21, lower insulation layer 22, upper furnace chamber heater 23, lower furnace chamber heater 24, heat shield 25, heat conduction hole 26, fixing bolt 27; Crucible system 3, crucible body 31, crucible tray 32; Lifting mechanism 4, motor support 41, lifting ball screw 42, lifting guide rod 43, lifting servo... Servo motor 44, lifting screw nut connecting plate 45, lifting screw nut 46; Rotating mechanism 5, rotating mechanism mounting plate 51, rotating servo motor 52, worm gear support seat 53, rotating worm gear 54, rotating worm 55, support rod 56; Lifting mechanism 6, lifting support frame 61, lifting servo motor 62, lifting ball screw 63, lifting guide rail 64, lifting screw nut mounting plate 65, lifting rod mounting seat 66, lifting ball screw nut 67, lifting rod 68, mold 69, guide sleeve 60. Detailed Implementation

[0019] To make the technical solution of the present invention easier to understand, the technical solution of the present invention will now be clearly and completely described in conjunction with the accompanying drawings and specific embodiments.

[0020] Example 1: like Figures 1 to 5 As shown, the apparatus for growing large-size sapphire plates using the guided mold method in this embodiment includes a growth furnace 1, a heating and insulation system 2, a crucible system 3, a lifting mechanism 4, a rotating mechanism 5, and a pulling mechanism 6, wherein: The growth furnace 1 includes a frame base 11, a lower furnace chamber 12 is provided on the upper side of the frame base 11, an upper furnace chamber 13 is provided on the upper side of the lower furnace chamber 12, a partition plate 14 is provided at the connection between the upper furnace chamber 13 and the lower furnace chamber 12, a frame base opening 15 is provided at the center of the frame base 11, and a partition plate opening 16 is provided at the center of the partition plate 14. The heating and insulation system 2 includes an upper insulation layer 21 located in the upper furnace chamber 13 and a lower insulation layer 22 located in the lower furnace chamber 12. An upper furnace chamber heater 23 is provided in the upper insulation layer 21, and a lower furnace chamber heater 24 is provided in the lower insulation layer 22. A heat shield 25 is provided in the opening 16 of the partition plate, and a heat conduction hole 26 is provided at the bottom of the heat shield 25. The upper furnace chamber heater 23 and the lower furnace chamber heater 24 are both installed on the side wall of the growth furnace 1 by fixing bolts 27. The crucible system 3 includes a crucible body 31, which is placed on a crucible tray 32. The crucible tray 32 is located in the lower furnace chamber 12 and below the heat shield 25. The lifting mechanism 4 includes a motor support 41 installed on the lower side of the opening 15 of the frame base. The motor support 41 has a vertically arranged lifting ball screw 42 and lifting guide rod 43 inside. A lifting servo motor 44 is installed on the lower side of the motor support 41. The power output end of the lifting servo motor 44 is connected to the lifting ball screw 42. A lifting nut connecting plate 45 is movably mounted on the lifting guide rod 43. A lifting nut 46 is provided on the lifting nut connecting plate 45. The upper thread of the lifting ball screw 42 is threaded into the lifting nut 46. The rotating mechanism 5 includes a rotating mechanism mounting plate 51 located on the upper side of the frame base 11. The rotating mechanism mounting plate 51 is fixedly connected to the lifting screw nut connecting plate 45. A rotating servo motor 52 and a worm gear support 53 are mounted on the upper side of the rotating mechanism mounting plate 51. The rotating servo motor 52 and the worm gear support 53 are located on both sides of the opening 15 of the frame base, respectively. The power output end of the rotating servo motor 52 is connected to the rotating worm 54. The other end of the rotating worm 54 is rotatably mounted on the worm gear support 53. The middle part of the rotating worm 54 is meshed with the rotating turbine 55. The rotating turbine 55 is fixedly mounted on the support rod 56. The crucible tray 32 is installed on the upper end of the support rod 56. The lifting mechanism 6 includes a lifting support frame 61, with a lifting servo motor 62 mounted on its top. Inside the lifting support frame 61 are a lifting ball screw 63 and a lifting guide rail 64. A lifting nut mounting plate 65 is movably mounted on the lifting guide rail 64. A lifting rod mounting seat 66 and a lifting ball screw nut 67 are mounted on the lifting nut mounting plate 65. A lifting rod 68 is mounted on the lifting rod mounting seat 66. The lifting ball screw nut 67 is threaded onto the lifting ball screw 63. The upper end of the lifting ball screw 63 is connected to the power output end of the lifting servo motor 62. The lower end of the lifting rod 68 is connected to a mold 69, which is located inside the crucible body 31. A guide sleeve 60 is provided at the lower part of the lifting support frame 61, and the lifting rod 68 is movably mounted within the guide sleeve 60.

[0021] Example 2: like Figures 1 to 5 As shown, the apparatus for growing large-size sapphire plates using the guided mold method in this embodiment, compared with Embodiment 1, further includes a feeding mechanism. The feeding mechanism includes a feeding pipe, a hopper, a vacuum pump, and a temperature sensor. The feeding pipe is located above the material dropping buffer mechanism and includes an inner pipe and an outer insulation material. The inner pipe is made of tungsten, molybdenum, or graphite material, and the outer insulation material is made of graphite soft felt or graphite hard felt. The hopper is located at one end of the feeding pipe, the vacuum pump is located on the feeding pipe, and the temperature sensor is located inside the feeding pipe.

[0022] The material feeding buffer mechanism is located at the center of the crucible body 31 and includes kinetic energy absorbing material and a buffer container. The kinetic energy absorbing material is made of molybdenum wire and tungsten wire through three-dimensional weaving, and the diameter of the molybdenum wire and tungsten wire is 0.2-2mm.

[0023] It also includes a control system, which includes a temperature controller, a gas flow controller and a growth controller. The temperature controller is electrically connected to the upper furnace chamber heater 23 and the lower furnace chamber heater 24. The gas flow controller is electrically connected to the air pump. The growth controller is electrically connected to the lifting servo motor 44, the rotation servo motor 52 and the pulling servo motor 62.

[0024] Example 3: like Figures 1 to 5 As shown, in this embodiment of the apparatus for growing large-size sapphire plates using the guided mold method, compared with Embodiment 1, both the upper furnace chamber heater 23 and the lower furnace chamber heater 24 are composed of plate-shaped graphite resistance heaters. The plate-shaped graphite resistance heaters are made of high-purity graphite material and coated with a high-temperature ceramic coating.

[0025] Both the upper insulation layer 21 and the lower insulation layer 22 are made of high-purity graphite soft felt or graphite hard felt, with a thickness of 50-100mm.

[0026] The crucible body 31 is made of high-purity molybdenum material.

[0027] The heat shield 25 is a groove with an inverted trapezoidal cross-section.

[0028] Working principle of the invention: 1. First, the material in the hopper is added to the crucible body through the feeding pipe. The hopper is located at one end of the feeding pipe and is used to store and quantitatively supply raw materials. An air pump is installed on the feeding pipe to draw in inert gas for heat exchange with the falling raw materials. A temperature sensor is installed inside the feeding pipe to detect the temperature and feed it back to the control system.

[0029] 2. By controlling the heating of the upper furnace chamber heater 23 and the lower furnace chamber heater 24 separately, the temperatures of the upper furnace chamber 13 and the lower furnace chamber 12 are controlled in zones, thereby controlling the melting and crystallization of the raw materials. The upper insulation layer 21 and the lower insulation layer 22 are respectively set outside the heaters to reduce heat loss. In use, the upper furnace chamber is a low-temperature zone with a temperature of about 1800℃, and the lower furnace chamber is a high-temperature zone with a temperature of about 2000℃. In addition, a screen is set between the upper furnace chamber 13 and the lower furnace chamber 12 to form a medium-temperature zone with a temperature between 1800 and 2000℃. The medium-temperature zone formed inside the screen lowers the temperature at the center of the crucible body 31, allowing crystallization to occur around the mold 69. The crystallization gradually diffuses from the center outwards, improving the crystal quality.

[0030] 3. A lifting mechanism 4 is provided at the bottom of the crucible body 31 to control the lifting and lowering of the crucible body 31. When the lifting servo motor 44 is started and rotated in both directions, it drives the lifting ball screw 42 to rotate. The lifting nut 46 moves up and down on the lifting ball screw 42, thereby driving the lifting nut connecting plate 45 to move up and down along the lifting guide rod 43. This, in turn, drives the entire lifting mechanism 6 to move up and down through the lifting support frame 61, meaning the support rod 56 also moves up and down simultaneously, ultimately causing the crucible body 31 to move up and down. During crystal growth, by controlling the up and down movement of the crucible body 31, it is possible to ensure that the solution height inside the crucible is insufficient in the later stages of crystal growth, preventing insufficient capillary pressure and hindering crystal growth, or resulting in excessive waste due to residual substrate, thus improving the efficiency of crystal growth.

[0031] 4. A rotating mechanism 5 is provided at the bottom of the crucible body 31 to control the rotation of the crucible body 31. The rotating servo motor 52 is started in both forward and reverse directions. The rotating servo motor 52 drives the rotating worm gear 54 to rotate, which in turn drives the rotating turbine 55 to rotate. This, in turn, drives the crucible tray 32 to rotate via the support rod 56, ultimately causing the crucible body 31 to rotate. During the crystallization process, the rotation of the crucible body 31 improves the flow of the solution inside the crucible, eliminates bubbles at the solid-liquid interface, ensures the production of high-quality crystals, and increases the capillary effect of a wider and thicker growth interface, thereby improving the growth momentum in the later stages of crystal growth.

[0032] 5. A lifting mechanism 6 is installed at the top for controlling the upward and downward lifting of the crystal. The lifting servo motor 62 is started to rotate in both directions, driving the lifting ball screw 63 to rotate. The lifting ball screw 67 moves up and down on the lifting ball screw 63, which in turn drives the lifting ball screw 65 to move up and down on the lifting guide rail 64. Finally, the crystal is lifted by the lifting rod 68 and the mold 69.

[0033] 6. In addition, a control system can be set up, which includes a temperature controller, a gas flow controller, and a growth controller. The temperature controller is used to control the temperature parameters of the heating and insulation system, the gas flow controller is used to control the operating parameters of the vacuum pump and the hopper, and the growth controller is used to control the lifting of the crystal and the raising and lowering of the crucible body 31 during the crystal growth process by controlling the lifting mechanism 4, the rotating mechanism 5, and the pulling mechanism 6. At the same time, the rotation of the crucible body removes air bubbles inside the crucible body 31 to ensure uniform crystal growth.

[0034] It should be noted that the embodiments described herein are only some embodiments of the present invention, and not all implementations of the present invention. These embodiments are merely illustrative and are intended only to provide a more intuitive and clear way to understand the content of the present invention, not to limit the technical solutions described herein. All other implementation methods that can be conceived by those skilled in the art without creative effort, as well as other simple substitutions and variations of the technical solutions of the present invention, without departing from the concept of the present invention, are within the protection scope of the present invention.

Claims

1. An apparatus for growing large-size sapphire plates using a guided mold method, characterized in that, It includes a growth furnace (1), a heating and insulation system (2), a crucible system (3), a lifting mechanism (4), a rotating mechanism (5), and a pulling mechanism (6), wherein: The growth furnace (1) includes a frame base (11), a lower furnace chamber (12) is provided on the upper side of the frame base (11), an upper furnace chamber (13) is provided on the upper side of the lower furnace chamber (12), a partition plate (14) is provided at the connection between the upper furnace chamber (13) and the lower furnace chamber (12), a frame base opening (15) is provided at the center of the frame base (11), and a partition plate opening (16) is provided at the center of the partition plate (14). The heating and insulation system (2) includes an upper insulation layer (21) in the upper furnace chamber (13) and a lower insulation layer (22) in the lower furnace chamber (12). The upper insulation layer (21) is equipped with an upper furnace chamber heater (23), and the lower insulation layer (22) is equipped with a lower furnace chamber heater (24). A heat shield (25) is provided in the opening (16) of the partition plate. A heat conduction hole (26) is provided at the bottom of the heat shield (25). The upper furnace chamber heater (23) and the lower furnace chamber heater (24) are both installed on the side wall of the growth furnace (1) by fixing bolts (27). The crucible system (3) includes a crucible body (31) which is placed on a crucible tray (32) which is located in the lower furnace chamber (12) and below the heat shield (25). The lifting mechanism (4) includes a motor support (41) installed on the lower side of the opening (15) of the frame base. The motor support (41) is vertically arranged with a lifting ball screw (42) and a lifting guide rod (43). A lifting servo motor (44) is installed on the lower side of the motor support (41). The power output end of the lifting servo motor (44) is connected to the lifting ball screw (42). A lifting nut connecting plate (45) is movably mounted on the lifting guide rod (43). A lifting nut (46) is provided on the lifting nut connecting plate (45). The upper thread of the lifting ball screw (42) is fitted into the lifting nut (46). The rotating mechanism (5) includes a rotating mechanism mounting plate (51) located on the upper side of the frame base (11). The rotating mechanism mounting plate (51) is fixedly connected to the lifting screw nut connecting plate (45). A rotating servo motor (52) and a worm support seat (53) are mounted on the upper side of the rotating mechanism mounting plate (51). The rotating servo motor (52) and the worm support seat (53) are located on both sides of the opening (15) of the frame base, respectively. The power output end of the rotating servo motor (52) is connected to the rotating worm (54). The other end of the rotating worm (54) is rotatably mounted on the worm support seat (53). The middle part of the rotating worm (54) is meshed with the rotating turbine (55). The rotating turbine (55) is fixedly mounted on the support rod (56). The crucible tray (32) is installed on the upper end of the support rod (56). The lifting mechanism (6) includes a lifting support frame (61), a lifting servo motor (62) is installed on the top of the lifting support frame (61), and a lifting ball screw (63) and a lifting guide rail (64) are provided inside the lifting support frame (61). A lifting nut mounting plate (65) is movably mounted on the lifting guide rail (64). A lifting rod mounting seat (66) and a lifting ball screw nut (67) are mounted on the lifting nut mounting plate (65). A lifting rod (68) is mounted on the lifting rod mounting seat (66). The lifting ball screw nut (67) is threaded onto the lifting ball screw (63). The upper end of the lifting ball screw (63) is connected to the power output end of the lifting servo motor (62). The lower end of the lifting rod (68) is connected to the mold (69). The mold is located inside the crucible body (31).

2. The apparatus for growing large-size sapphire plates using the guided mold method as described in claim 1, characterized in that, The lower part of the lifting support frame (61) is provided with a guide sleeve (60), and the lifting rod (68) is movably fitted inside the guide sleeve (60).

3. The apparatus for growing large-size sapphire plates using the guided mold method as described in claim 1, characterized in that, It also includes a feeding mechanism, which includes a feeding pipe, a hopper, an air pump, and a temperature sensor. The feeding pipe is located above the material dropping buffer mechanism and includes an inner pipe and an outer insulation material. The inner pipe is made of tungsten, molybdenum, or graphite, and the outer insulation material is made of graphite soft felt or graphite hard felt. The hopper is located at one end of the feeding pipe, the air pump is located on the feeding pipe, and the temperature sensor is located inside the feeding pipe.

4. The apparatus for growing large-size sapphire plates using the guided mold method as described in claim 3, characterized in that, The material feeding buffer mechanism is located at the center of the crucible body (31) and includes kinetic energy absorbing material and buffer container. The kinetic energy absorbing material is made of molybdenum wire and tungsten wire through three-dimensional weaving, and the diameter of the molybdenum wire and tungsten wire is 0.2-2mm.

5. The apparatus for growing large-size sapphire plates using the guided mold method as described in claim 3, characterized in that, It also includes a control system, which includes a temperature controller, a gas flow controller and a growth controller. The temperature controller is electrically connected to the upper furnace chamber heater (23) and the lower furnace chamber heater (24). The gas flow controller is electrically connected to the air pump. The growth controller is electrically connected to the lifting servo motor (44), the rotation servo motor (52) and the pulling servo motor (62).

6. The apparatus for growing large-size sapphire plates using the guided mold method as described in claim 1, characterized in that, The upper furnace chamber heater (23) and the lower furnace chamber heater (24) are both composed of plate-shaped graphite resistance heaters. The plate-shaped graphite resistance heaters are made of high-purity graphite material and coated with a high-temperature ceramic coating.

7. The apparatus for growing large-size sapphire plates using the guided mold method as described in claim 1, characterized in that, The upper insulation layer (21) and the lower insulation layer (22) are both made of high-purity graphite soft felt or graphite hard felt, with a thickness of 50-100mm.

8. The apparatus for growing large-size sapphire plates using the guided mold method as described in claim 1, characterized in that, The crucible body (31) is made of high-purity molybdenum material.

9. The apparatus for growing large-size sapphire plates using the guided mold method as described in claim 1, characterized in that, The heat shield (25) is a groove with an inverted trapezoidal cross-section.

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