Hard shaft heavy-load silicon single crystal pulling device

Abstract

The present invention provides a hard-shaft heavy-load silicon single crystal pulling device, comprising a support structure, a single crystal load-bearing outer hard shaft with a single crystal claw mounted on its bottom, a seed crystal load-bearing inner hard shaft with a seed crystal chuck mounted on its bottom, a rotary drive device for driving the single crystal load-bearing outer hard shaft to rotate, an outer hard shaft lifting device for driving the single crystal load-bearing outer hard shaft to rise and fall, and an inner hard shaft lifting device for driving the seed crystal load-bearing inner hard shaft to rise and fall. The present invention achieves synchronous rotation of the inner and outer hard shafts, independent lifting and falling motion of the outer and inner hard shafts, has strong strength and rigidity, can carry single crystals weighing more than 500 kg, compensates for the insufficient load-bearing capacity of a soft-shaft pulling device, avoids soft-shaft swing and pendulum resonance in the soft-shaft pulling device, and can overcome crystal disturbances caused by thermal field symmetry deviations, airflow excitation force symmetry deviations, and other aspects.

Description

Technical Field

[0001] The present invention relates to a crystal pulling device for a large-size, heavy-weight photovoltaic-grade or electronic-grade silicon single crystal Czochralski growth furnace, specifically a hard-shaft heavy-load silicon single crystal pulling device with high pulling guide accuracy, small single crystal disturbance, high crystal intrinsic quality and crystal external shape quality, and large load-bearing capacity, especially a hard-shaft heavy-load silicon single crystal pulling device. Background Art

[0002] Silicon single crystals are the fundamental material for the photovoltaic cell and semiconductor industries. Over 90% of photovoltaic cells and over 95% of semiconductor devices utilize silicon-based substrates. Czochralski silicon single crystal technology is highly mature and dominates the market. To improve production efficiency and reduce costs for photovoltaic cells and semiconductor devices, silicon single crystals are trending toward larger diameters and heavier weights. When a silicon single crystal weighs 500 kg or more, a flexible-shaft winch is inadequate due to the limited load-bearing capacity of the tungsten wire rope, requiring a rigid-shaft heavy-load hoisting device.

[0003] As the photoelectric conversion efficiency, service life, attenuation rate of photovoltaic cells, and the characteristic line width and performance parameter requirements of semiconductor devices continue to increase, the quality requirements for silicon single crystals are also getting higher and higher.

[0004] During the growth of silicon single crystals using a tungsten wire rope as the pulling axis, crystal disturbance (or wobble) is a common phenomenon. When the crystal is disturbed, the ADC (Auto Diameter Control) system that monitors the growing crystal diameter will not accurately monitor the diameter, causing abnormal feedback signals and periodic fluctuations in the pulling speed. Disturbance can cause changes in the microscopic diffusion layer at the moment of growth, resulting in variations in the effective segregation coefficient and radial inhomogeneity in the microscopic dopant concentration distribution. Disturbance can also cause unstable melt convection, leading to changes in the solid-liquid interface supercooling during growth and facilitating dendrite growth. Furthermore, as the crystal is pulled upward and the length of the tungsten wire rope decreases, the system resonant frequency of the pulling mechanism continuously changes, easily causing resonance between the crystal and the pulling mechanism. Consequently, crystal disturbance can adversely affect the intrinsic crystal quality, such as resistivity and microdefects, as well as the external shape of the single crystal and the stability of crystal growth.

[0005] The causes of crystal disturbance are: first, the vibration of vacuum pump, circulating water, compressed air, foundation and environment; second, thermal field: if the thermal field is not symmetrical, the melt in the crucible is prone to generate eddy current, which becomes the periodic exciting force of crystal disturbance; third, airflow: after the crystal enters the auxiliary furnace chamber, the protective gas filled from the top of the auxiliary furnace chamber flows through the crystal surface, the flow area becomes smaller and the flow rate increases. If the thermal field is not symmetrical, or the vacuum exhaust holes on both sides of the furnace bottom plate are partially blocked, causing the exhaust force to fluctuate or produce a large difference, it is easy to cause disturbance due to the excitation of airflow. The fourth is the influence of the single crystal growth process parameter setting on the single crystal disturbance. The single crystal growth is a period of rotation and pulling motion immersed in the melt. At this time, the process growth parameters such as crystal rotation speed have a greater impact on the melt convection. At the same time, the process parameter setting should try to avoid the resonance range of crystal disturbance. Therefore, a good process setting is one of the effective ways to reduce the single crystal disturbance; the fifth is the disturbance caused by human factors, such as stepping on the base, leaning on the furnace body, running operation, etc.; the sixth is the poor centering of the crystal pulling axis and the crucible axis, which is also the excitation source of the disturbance. Summary of the Invention

[0006] In order to solve the above technical problems, a hard-shaft heavy-load silicon single crystal pulling device is provided.

[0007] The technical means adopted in the present invention are as follows:

[0008] A hard-shaft heavy-load silicon single crystal pulling device, comprising:

[0009] The supporting structure is fixed vertically on the top of the vacuum furnace chamber;

[0010] A single crystal load-bearing external rigid shaft, which is a hollow structure and is vertically installed in the support structure, with its bottom penetrating into the vacuum furnace chamber, and the inner wall of the single crystal load-bearing external rigid shaft is processed with a vertically extending spline groove;

[0011] A seed crystal load-bearing inner hard shaft is vertically arranged in the single crystal load-bearing outer hard shaft, and the outer wall of the seed crystal load-bearing inner hard shaft has a spline that cooperates with the spline groove;

[0012] A single crystal clamping claw is fixedly connected to the bottom of the single crystal load-bearing outer hard shaft and is used to clamp the small shoulder of the single crystal;

[0013] A seed crystal chuck is fixedly connected to the bottom of the seed crystal load-bearing inner hard shaft and is used to fix the seed crystal on the top of the single crystal;

[0014] A rotation drive device is installed in the support structure and is located above the single crystal load-bearing external hard shaft, and is used to drive the single crystal load-bearing external hard shaft to rotate;

[0015] An external rigid shaft lifting device, installed on the top of the support structure, used to drive the single crystal load-bearing external rigid shaft to move up and down;

[0016] An inner hard shaft lifting device is installed in the supporting structure and is used to drive the seed crystal load-bearing inner hard shaft to rise and fall.

[0017] Furthermore, the outer hard shaft lifting device includes:

[0018] Four vertically arranged slide rails, the cross-section of the support structure is square, and the four slide rails are respectively installed at the four corners of the support structure;

[0019] A slide is mounted on the upper portion of the single crystal load-bearing external rigid shaft, and the single crystal load-bearing external rigid shaft axially passes through the slide. The slide is axially fixedly connected to the single crystal load-bearing external rigid shaft and is circumferentially connected to the single crystal load-bearing external rigid shaft via a magnetic fluid. The four corners of the slide are respectively slidably connected to the four slide rails.

[0020] Two external rigid shaft lifting drive devices are symmetrically mounted on both sides of the top of the support structure;

[0021] The outer hard shaft lifting drive device comprises:

[0022] A worm reducer is fixedly mounted on the outer wall of the support structure, and an external hard shaft driving pulley is mounted on the output end of the worm reducer;

[0023] a planetary reducer, the output end of which is connected to the input end of the worm reducer;

[0024] An external hard-shaft servo motor, the output end of which is connected to the input end of the planetary reducer;

[0025] An external rigid shaft lead screw is vertically mounted in the support structure, an external rigid shaft driven pulley is fixed to the top of the lead screw, the lead screw passes through the slide, and a lead screw nut is fixedly connected to the slide;

[0026] A synchronous toothed belt is used to connect the outer hard shaft driving pulley and the outer hard shaft driven pulley.

[0027] Furthermore, the rotation drive device includes:

[0028] A rotary reducer is fixedly mounted on the upper surface of the slide, and a rotary driving pulley is mounted on the output end thereof;

[0029] a rotating driven pulley fixed to the top of the single crystal load-bearing outer rigid shaft;

[0030] A rotating platform is arranged above the rotating driven pulley and is fixedly connected to the rotating driven pulley;

[0031] A belt is used to connect the rotating driving pulley and the rotating driven pulley.

[0032] Furthermore, the inner hard shaft lifting device includes:

[0033] An inner hard shaft screw is vertically arranged, and its screw rod penetrates into the seed crystal load-bearing inner hard shaft, and its screw nut is fixedly connected to the top inner wall of the seed crystal load-bearing inner hard shaft, and the top end of the seed crystal load-bearing inner hard shaft passes through the rotating platform;

[0034] An inner hard shaft servo motor is fixedly connected to the rotating platform via a bracket;

[0035] The input end of the inner hard shaft reducer is connected to the output end of the inner hard shaft servo motor through a coupling, and the output end is connected to the top of the screw of the inner hard shaft screw through a coupling.

[0036] Furthermore, the single crystal clamping claw includes four clamping claws, and the four clamping claws are evenly distributed around the axis of the single crystal load-bearing external hard shaft, and the middle parts of the four clamping claws are hinged to the outer wall of the single crystal load-bearing external hard shaft, and the bottom of the single crystal load-bearing external hard shaft is processed with an opening at the upper part of the clamping claw, and the bottom of the clamping claw has a clamping part; the four clamping parts extend toward the axis of the single crystal load-bearing external hard shaft, and the top surface of the clamping part has a conical surface, and the conical surface matches the conical surface of the bottom of the small shoulder of the single crystal.

[0037] Furthermore, a claw driving device is fixed on the upper surface of the rotating platform, and the claw driving device is used to drive the single crystal claw to grasp or release the small shoulder of the single crystal, and the top end of the seed crystal load-bearing inner hard shaft passes through the claw driving device.

[0038] Furthermore, the clamping claw driving device includes a winding wheel housing fixedly connected to the top of the rotating platform, and the winding wheel housing is provided with four winding shafts rotatably connected to the winding wheel housing, the axes of the winding shafts are perpendicular to the axes of the single crystal load-bearing external hard shaft, and the winding wheels are fixed on the winding shafts; each of the winding wheels is connected to a winding shaft driving mechanism that drives the winding shaft to rotate, and the winding shaft driving mechanism is arranged outside the winding wheel housing, and the winding shaft driving mechanism includes a servo motor and a reducer connected to the output end of the servo motor, and the output end of the reducer is connected to the winding shaft through a coupling. The winding wheel is fixedly connected to one end of the tungsten wire rope, and the other end of the tungsten wire rope passes through a tungsten wire rope hole vertically machined in the single crystal load-bearing external hard shaft and is fixedly connected to the upper part of the clamping claw;

[0039] A spring accommodating cavity is processed at the bottom of the tungsten wire rope through-hole, and a pre-tightening spring is provided in the spring accommodating cavity and is sleeved outside the tungsten wire rope. The top of the pre-tightening spring is against the top of the spring accommodating cavity, and the bottom of the pre-tightening spring is against the top of the claw.

[0040] The winding wheel box and the weighing cover are both provided with tungsten wire rope limiting blocks for limiting the position of the tungsten wire rope.

[0041] Furthermore, a weighing cover is fixed to the upper surface of the claw drive device, and a silicon single crystal weighing device is installed in the weighing cover. The silicon single crystal weighing device is used to weigh the single crystal. The silicon single crystal weighing device includes a weighing sensor installed at the top inner surface of the weighing cover, and the bottom of the weighing sensor is connected to a weighing fixed pulley installed in the weighing cover. The weighing fixed pulley is arranged directly above one of the four winding wheels, and the tungsten wire rope connected to the winding wheel passes through the weighing fixed pulley and enters the tungsten wire rope through hole, and is then fixedly connected to the upper portion of the claw.

[0042] Furthermore, the top of the seed crystal load-bearing inner hard shaft is covered with an inner shaft bellows, the top end of which is fixedly connected to the top of the seed crystal load-bearing inner hard shaft and sealed by a sealing ring, and the bottom end of which is sealed and fixedly connected to the upper surface of the claw driving device.

[0043] Furthermore, the single crystal load-bearing outer hard shaft is covered with an outer shaft bellows, the top end of the outer shaft bellows is sealed and fixedly connected to the lower surface of the slide seat, and the bottom end of the outer shaft bellows is sealed and fixedly connected to the top of the vacuum furnace chamber.

[0044] Compared with the prior art, the present invention has the following advantages:

[0045] The growth of silicon single crystals needs to go through two processes of shoulder release, shoulder rotation, and equal diameter. The first process of shoulder release, shoulder rotation, and equal diameter is after the neck is completed. It is necessary to grow a small shoulder with an outer diameter of φ5 to 6 inches, an equal diameter length greater than 1 inch, and a tail diameter of φ2.5 to 3 inches after the end. The small shoulder is the working surface of the single crystal claw to grasp the single crystal. The second shoulder release is after the first end, when the equal diameter is φ2.5 to 3 inches and the length is greater than 2 inches. The remaining crystal growth process and shape and size characteristics are in accordance with the requirements of the single crystal product.

[0046] The inner and outer hard shaft lifting devices are precision-grade linear friction pairs with high precision and stability. They can effectively reduce crystal disturbance, dislocations, and improve crystal quality. They are suitable for photovoltaic-grade or electronic-grade silicon single crystal growth systems with low crystal defect rates.

[0047] When the inner hard shaft bears the load, it can meet the needs of growing crystals weighing less than 500 kg. When the inner and outer hard shafts bear the load together, they can meet the needs of growing silicon single crystals weighing 500 kg or more. The present invention realizes the synchronous rotation of the inner and outer hard shafts, the independent lifting and lowering movement of the outer hard shaft, and the independent lifting and lowering movement of the inner hard shaft. It has strong strength and rigidity, can carry single crystals weighing more than 500 kg, compensates for the insufficient load-bearing capacity of the flexible shaft pulling device, avoids flexible shaft swing and low-speed resonance in the flexible shaft pulling device, and can overcome crystal disturbances caused by thermal field symmetry deviation and airflow excitation force symmetry deviation.

[0048] Replace the tungsten wire rope soft shaft winch and pulling device to make up for the shortcomings of small load-bearing capacity and large crystal disturbance, improve the intrinsic quality of the crystal such as lattice defects, resistivity and its uniformity, carbon and oxygen content, minority carrier lifetime and the qualified rate of single crystal external shape, and pull large-diameter electronic-grade single crystals such as Φ12 to 18 inches.

[0049] Based on the above reasons, the present invention can be widely promoted in the fields of large-size and heavy photovoltaic-grade or electronic-grade Czochralski (CZ) silicon single crystal production. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0051] Figure 1 This is a front view of a hard-shaft heavy-load silicon single crystal pulling device in a specific embodiment of the present invention.

[0052] Figure 2 for Figure 1 Center A view.

[0053] Figure 3 for Figure 1 Enlarged view of part B in the middle.

[0054] Figure 4 for Figure 1 Middle CC section view.

[0055] Figure 5 This is a front view of a single crystal clamp in a specific embodiment of the present invention.

[0056] Figure 6 for Figure 5 Middle DD cross-sectional view.

[0057] Figure 7 It is a structural schematic diagram of the claw driving device in a specific embodiment of the present invention.

[0058] In the picture:

[0059] 1. Support structure;

[0060] 2. Vacuum furnace chamber;

[0061] 3. Single crystal load-bearing external hard shaft; 301. Tungsten wire rope through hole; 302. External shaft bellows;

[0062] 4. Seed crystal bearing inner hard shaft; 401. Inner shaft bellows; 402. Sealing ring;

[0063] 5. Single crystal claw; 501. Claw; 502. Clamping portion;

[0064] 6. Single crystal; 601. Small shoulder; 602. Seed crystal;

[0065] 7. Seed crystal holder;

[0066] 8. Rotary drive device; 801. Rotary reducer; 802. Rotary driving pulley; 803. Rotary driven pulley; 804. Rotary platform; 805. Belt;

[0067] 9. External rigid shaft lifting device; 901. Slide rail; 902. Slide seat; 903. Worm reducer; 904. External rigid shaft driving pulley; 905. Planetary reducer; 906. External rigid shaft servo motor; 907. External rigid shaft lead screw; 908. External rigid shaft driven pulley; 909. Synchronous toothed belt;

[0068] 10. Internal hard shaft lifting device; 1001. Internal hard shaft lead screw; 1002. Internal hard shaft servo motor; 1003. Bracket; 1004. Internal hard shaft reducer;

[0069] 11. Claw drive device; 1101. Winding wheel housing; 1102. Winding shaft; 1103. Winding wheel; 1104. Tungsten wire rope; 1105. Preload spring; 1106. Weighing cover; 1107. Weighing sensor; 1108. Weighing fixed pulley; 1109. Tungsten wire rope limit block; DETAILED DESCRIPTION

[0070] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0071] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0072] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0073] Unless otherwise specifically stated, the relative arrangement of the parts and steps, numerical expressions and numerical values ​​described in these embodiments do not limit the scope of the present invention. At the same time, it should be clear that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The techniques, methods and equipment known to ordinary technicians in the relevant fields may not be discussed in detail, but where appropriate, the techniques, methods and equipment should be considered as part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following figures, so once an item is defined in one figure, it does not need to be further discussed in subsequent figures.

[0074] In the description of the present invention, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, vertical, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention: the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0075] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figures. For example, if the device in the drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below their position devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0076] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0077] like Figures 1 to 7 As shown, the present invention discloses a hard shaft heavy-load silicon single crystal pulling device, comprising:

[0078] A support structure 1 is vertically fixed to the top of the vacuum furnace chamber 2, and the cross section of the support structure 1 is square;

[0079] The single crystal load-bearing external rigid shaft 3 is a hollow structure and is vertically installed in the support structure 1, with its bottom penetrating into the vacuum furnace chamber 2. The inner wall of the single crystal load-bearing external rigid shaft 3 is processed with a vertically extending spline groove;

[0080] The seed crystal load-bearing inner hard shaft 4 is vertically arranged in the single crystal load-bearing outer hard shaft, and the outer wall of the seed crystal load-bearing inner hard shaft 4 has a spline that cooperates with the spline groove; the single crystal load-bearing outer hard shaft 3 and the seed crystal load-bearing inner hard shaft 4 are connected by the spline and the spline groove to achieve vertical sliding connection and circumferential synchronous movement;

[0081] The single crystal clamping claw 5 is fixedly connected to the bottom of the single crystal load-bearing outer hard shaft 3 and is used to clamp the small shoulder 601 of the single crystal 6;

[0082] A seed crystal chuck 7 is fixedly connected to the bottom of the seed crystal load-bearing inner hard shaft 4 and is used to fix the seed crystal 602 on the top of the single crystal 6;

[0083] A rotation drive device 8 is installed in the support structure 1 and is located above the single crystal load-bearing outer hard shaft 3, and is used to drive the single crystal load-bearing outer hard shaft 3 to rotate;

[0084] An external rigid shaft lifting device 9 is installed on the top of the support structure 1 and is used to drive the single crystal load-bearing external rigid shaft 3 to move up and down;

[0085] The inner hard shaft lifting device 10 is installed in the support structure 1 and is used to drive the seed crystal load-bearing inner hard shaft 4 to move up and down.

[0086] Furthermore, the outer hard shaft lifting device 9 includes:

[0087] Four vertically arranged slide rails 901, the four slide rails 901 are respectively installed at the four corners of the support structure 1;

[0088] Slide 902 is mounted on the upper portion of the single crystal load-bearing outer rigid shaft 3, and the single crystal load-bearing outer rigid shaft 3 axially passes through the slide 902. The slide 902 is axially fixedly connected to the single crystal load-bearing outer rigid shaft 3 and is circumferentially connected to the single crystal load-bearing outer rigid shaft 3 via magnetic fluid. The four corners of the slide 902 are respectively slidably connected to the four slide rails 901.

[0089] Two external rigid shaft lifting drive devices are symmetrically installed on both sides of the top of the support structure 1;

[0090] The outer hard shaft lifting drive device comprises:

[0091] A worm reducer 903 is fixedly mounted on the outer wall of the support structure 1, and an external hard shaft driving pulley 904 is mounted on the output end of the worm reducer 903;

[0092] A planetary reducer 905, whose output end is connected to the input end of the worm reducer 903;

[0093] An external hard-shaft servo motor 906 , whose output end is connected to the input end of the planetary reducer 905 ;

[0094] An external rigid shaft lead screw 907 is vertically mounted in the support structure 1 , with an external rigid shaft driven pulley 908 fixed to the top of the lead screw, and the lead screw passes through the slide 902 , with the lead screw nut fixedly connected to the slide 902 ;

[0095] The synchronous toothed belt 909 is used to connect the outer hard shaft driving pulley 904 and the outer hard shaft driven pulley 908 .

[0096] Furthermore, the rotation drive device 8 includes:

[0097] The rotary reducer 801 is fixedly mounted on the upper surface of the slide 902, and a rotary driving pulley 802 is mounted on its output end;

[0098] A rotating driven pulley 803 is fixed on top of the single crystal load-bearing outer hard shaft 3;

[0099] A rotating platform 804 is provided above the rotating driven pulley 803 and is fixedly connected to the rotating driven pulley 803;

[0100] The belt 805 is used to connect the rotating driving pulley 802 and the rotating driven pulley 803 .

[0101] The inner hard shaft lifting device 10 includes:

[0102] The inner rigid shaft lead screw 1001 is vertically arranged, and its lead screw penetrates into the seed crystal load-bearing inner rigid shaft 4, and its lead screw nut is fixedly connected to the top inner wall of the seed crystal load-bearing inner rigid shaft 4, and the top end of the seed crystal load-bearing inner rigid shaft 4 passes through the rotating platform 804;

[0103] The inner hard shaft servo motor 1002 is fixedly connected to the rotating platform 804 via a bracket 1003;

[0104] The input end of the inner hard shaft reducer 1004 is connected to the output end of the inner hard shaft servo motor 1002 through a coupling, and the output end is connected to the top of the inner hard shaft lead screw 1001 through a coupling.

[0105] Furthermore, the single crystal clamping claw 5 includes four clamping claws 501, and the four clamping claws 501 are evenly distributed around the axis of the single crystal load-bearing external hard shaft 3, and the middle parts of the four clamping claws 501 are hinged to the outer wall of the single crystal load-bearing external hard shaft 3, and the bottom of the single crystal load-bearing external hard shaft 3 is processed with an opening at the upper part of the clamping claw, and the bottom of the clamping claw 501 has a clamping portion 502; the four clamping portions 502 extend toward the axis of the single crystal load-bearing external hard shaft 3, and the top surface of the clamping portion 502 has a conical surface, and the conical surface matches the conical surface at the bottom of the small shoulder 601 of the single crystal 6.

[0106] Furthermore, a claw driving device 11 is fixed on the upper surface of the rotating platform 804, and the claw driving device 11 is used to drive the single crystal claw 5 to grasp or release the small shoulder 601 of the single crystal 6, and the top end of the seed crystal load-bearing inner hard shaft 4 passes through the claw driving device 11.

[0107] Furthermore, the claw driving device 11 includes a winding wheel box 1101 fixedly connected to the top of the rotating platform 804, and four winding shafts 1102 are provided in the winding wheel box 1101 (the view of the present invention is a sectional view so only one can be seen, and there are actually four). The axis of the winding shaft 1102 is perpendicular to the axis of the single crystal load-bearing external hard shaft 3, and a winding wheel 1103 is fixed on the winding shaft 1102; each of the winding wheels 1103 is connected to a winding shaft driving mechanism that drives the winding shaft 1102 to rotate, and the winding shaft driving mechanism is arranged outside the winding wheel box 1101, and the winding shaft driving mechanism includes a servo motor and a reducer connected to the output end of the servo motor, and the output end of the reducer is connected to the winding shaft through a coupling. The winding wheel 1103 is fixedly connected to one end of the tungsten wire rope 1104, and the other end of the tungsten wire rope 1104 passes through the tungsten wire rope through hole 301 vertically machined in the single crystal load-bearing outer hard shaft 3 and is fixedly connected to the upper part of the clamping claw 501;

[0108] A spring accommodating cavity is machined at the bottom of the tungsten wire rope through-hole 301, and a pre-tightening spring 1105 is provided in the spring accommodating cavity and is sleeved on the outside of the tungsten wire rope 1104. The top of the pre-tightening spring 1105 is against the top of the spring accommodating cavity, and the bottom of the pre-tightening spring 1105 is against the top of the claw 501.

[0109] Furthermore, a weighing cover 1106 is fixed to the upper surface of the clamping claw drive device 11, and a silicon single crystal weighing device is installed in the weighing cover 1106. The silicon single crystal weighing device is used to weigh the single crystal. The silicon single crystal weighing device includes a weighing sensor 1107 installed at the top of the inner portion of the weighing cover 1106, and the bottom of the weighing sensor 1107 is connected to a weighing fixed pulley 1108 installed in the weighing cover 1106. The weighing fixed pulley 1108 is arranged directly above one of the four winding wheels 1103. The tungsten wire rope 1104 connected to the winding wheel 1103 passes through the weighing fixed pulley 1108 and enters the tungsten wire rope through hole 301, and is then fixedly connected to the upper portion of the clamping claw 501.

[0110] Tungsten wire rope limiting blocks 1109 for limiting the position of the tungsten wire rope 1104 are provided in the winding wheel housing 1101 and the weighing cover 1106 .

[0111] The top of the seed crystal load-bearing inner hard shaft 4 is covered with an inner shaft bellows 401, the top of which is fixedly connected to the top of the seed crystal load-bearing inner hard shaft 4 and sealed by a sealing ring, and the bottom of which is sealed and fixedly connected to the upper surface of the claw driving device 11.

[0112] Furthermore, the single crystal load-bearing external hard shaft 3 is covered with an external shaft bellows 302, the top end of the external shaft bellows 302 is sealed and fixedly connected to the lower surface of the slide 902, and the bottom end of the external shaft bellows 302 is sealed and fixedly connected to the top of the vacuum furnace chamber 2.

[0113] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A hard shaft heavy-load silicon single crystal pulling device, characterized in that: include: The supporting structure is fixed vertically on the top of the vacuum furnace chamber; A single crystal load-bearing external rigid shaft, which is a hollow structure and is vertically installed in the support structure, with its bottom penetrating into the vacuum furnace chamber, and the inner wall of the single crystal load-bearing external rigid shaft is processed with a vertically extending spline groove; The seed crystal load-bearing inner hard shaft is vertically arranged in the single crystal load-bearing outer hard shaft, and the outer wall of the seed crystal load-bearing inner hard shaft has a spline that cooperates with the spline groove; the single crystal load-bearing outer hard shaft and the seed crystal load-bearing inner hard shaft are connected by the spline and can move synchronously in the circumferential direction through the spline and the spline groove; A single crystal clamping claw is fixedly connected to the bottom of the single crystal load-bearing outer hard shaft and is used to clamp the small shoulder of the single crystal; A seed crystal chuck is fixedly connected to the bottom of the seed crystal load-bearing inner hard shaft and is used to fix the seed crystal on the top of the single crystal; A rotation drive device is installed in the support structure and is located above the single crystal load-bearing external hard shaft, and is used to drive the single crystal load-bearing external hard shaft to rotate; An external rigid shaft lifting device, installed on the top of the support structure, used to drive the single crystal load-bearing external rigid shaft to move up and down; An inner hard shaft lifting device is installed in the support structure and is used to drive the seed crystal load-bearing inner hard shaft to move up and down; The outer hard shaft lifting device comprises: Four vertically arranged slide rails, the cross-section of the support structure is square, and the four slide rails are respectively installed at the four corners of the support structure; A slide is mounted on the upper portion of the single crystal load-bearing external rigid shaft, and the single crystal load-bearing external rigid shaft axially passes through the slide. The slide is axially fixedly connected to the single crystal load-bearing external rigid shaft and is circumferentially connected to the single crystal load-bearing external rigid shaft via a magnetic fluid. The four corners of the slide are respectively slidably connected to the four slide rails. Two external rigid shaft lifting drive devices are symmetrically mounted on both sides of the top of the support structure; The outer hard shaft lifting drive device comprises: A worm reducer is fixedly mounted on the outer wall of the support structure, and an external hard shaft driving pulley is mounted on the output end of the worm reducer; A planetary reducer, the output end of which is connected to the input end of the worm reducer; An external hard-shaft servo motor, the output end of which is connected to the input end of the planetary reducer; An external hard shaft lead screw is vertically mounted in the support structure, an external hard shaft driven pulley is fixed to the top of the lead screw, the lead screw passes through the slide, and the lead screw nut is fixedly connected to the slide; A synchronous toothed belt is used to connect the outer hard shaft driving pulley and the outer hard shaft driven pulley.

2. The hard-shaft heavy-load silicon single crystal pulling device according to claim 1, characterized in that: The rotary drive device comprises: A rotary reducer is fixedly mounted on the upper surface of the slide, and a rotary driving pulley is mounted on the output end thereof; a rotating driven pulley fixed to the top of the single crystal load-bearing outer rigid shaft; A rotating platform is arranged above the rotating driven pulley and is fixedly connected to the rotating driven pulley; A belt is used to connect the rotating driving pulley and the rotating driven pulley.

3. The hard-shaft heavy-load silicon single crystal pulling device according to claim 2, characterized in that: The inner hard shaft lifting device comprises: An inner hard shaft screw is vertically arranged, and its screw rod penetrates into the seed crystal load-bearing inner hard shaft, and its screw nut is fixedly connected to the top inner wall of the seed crystal load-bearing inner hard shaft, and the top end of the seed crystal load-bearing inner hard shaft passes through the rotating platform; An inner hard shaft servo motor is fixedly connected to the rotating platform via a bracket; The input end of the inner hard shaft reducer is connected to the output end of the inner hard shaft servo motor through a coupling, and the output end is connected to the top of the screw of the inner hard shaft screw through a coupling.

4. The hard-shaft heavy-load silicon single crystal pulling device according to claim 3, characterized in that: A claw driving device is fixed on the upper surface of the rotating platform, and the claw driving device is used to drive the single crystal claw to grasp or release the small shoulder of the single crystal, and the top end of the seed crystal load-bearing inner hard shaft passes through the claw driving device.

5. The hard-shaft heavy-load silicon single crystal pulling device according to claim 4, characterized in that: The top of the seed crystal load-bearing inner hard shaft is covered with an inner shaft bellows, the top end of which is fixedly connected to the top of the seed crystal load-bearing inner hard shaft, and the bottom end of which is fixedly connected to the upper surface of the claw driving device.

6. The hard-shaft heavy-load silicon single crystal pulling device according to claim 4, characterized in that: A weighing cover is fixed on the upper surface of the claw driving device, and a silicon single crystal weighing device is installed in the weighing cover. The silicon single crystal weighing device is used to weigh the single crystal.

7. The hard-shaft heavy-load silicon single crystal pulling device according to claim 1, characterized in that: The single crystal load-bearing outer hard shaft is covered with an outer shaft bellows, the top end of the outer shaft bellows is fixedly connected to the lower surface of the slide seat, and the bottom end of the outer shaft bellows is fixedly connected to the top of the vacuum furnace chamber.

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