A method for adjusting a seed rod

Abstract

The application discloses the technical field of single crystal growth, and particularly discloses a seed rod centering method, which adopts a centering device for adjustment, wherein the centering device comprises a motor, an upper connecting mechanism, an adjusting mechanism, a lower connecting mechanism and a seed rod; the motor shaft and the seed rod are both vertically arranged; the adjustment specifically comprises the following steps: (1) placing a reference piece below the seed rod; (2) starting the motor to rotate at a speed lower than 10 r / min; (3) observing the deviation between the rotating track of the seed rod and the reference piece, and closing the motor at the maximum deviation; (4) fastening the adjusting screw on the adjusting mechanism in the opposite direction to make the adjusting block on the adjusting mechanism close to the center, and then repeating steps (2) and (3); and (5) repeating steps (2)-(4) until the end of the seed rod has a deviation of ≤0.1 mm. The application has high centering precision, is convenient to operate and can effectively improve the efficiency of single crystal growth.

Description

Technical Field

[0001] This invention belongs to the field of single crystal growth technology, and relates to seed crystal rod centering, specifically to a seed crystal rod centering method. Background Technology

[0002] Single crystal growth is a fundamental material preparation process in high-end technology fields such as semiconductors, optics, and lasers, and its quality directly affects the performance and reliability of devices. In single crystal growth equipment, the seed crystal rod, as a key component guiding the directional growth of the crystal, has a decisive influence on the crystallization rate, lattice integrity, and defect density due to its concentricity with the rotation axis (i.e., "centering").

[0003] In traditional single crystal growth equipment, the seed crystal rod is usually connected to the motor rotation shaft through a simple mechanical connection. Centering often relies on manual experience, with rough adjustments made using simple structures such as shims and screws. Using this type of structure for centering suffers from problems such as low centering accuracy, poor stability, limited load-bearing capacity, cumbersome operation, and low efficiency. Summary of the Invention

[0004] In view of the above-mentioned shortcomings of the existing technology, the purpose of this invention is to provide a seed crystal rod centering method. The centering accuracy of this invention is high, the operation is convenient, and it can effectively improve the efficiency of single crystal growth.

[0005] The technical solution of this invention is implemented as follows: A seed crystal rod centering method is provided, which uses a centering device for adjustment. The centering device includes a motor, an upper connecting mechanism, an adjusting mechanism, a lower connecting mechanism, and a seed crystal rod; both the motor shaft and the seed crystal rod are vertically arranged.

[0006] The upper connecting mechanism includes a horizontally arranged connecting plate and an upper connecting rod vertically arranged above the connecting plate. The lower end of the upper connecting rod is fixedly connected to the center of the connecting plate, and the upper end of the upper connecting rod is connected to the lower end of the motor shaft. A plurality of first connecting holes are evenly distributed on the connecting plate.

[0007] The lower connecting mechanism includes a horizontally arranged circular moving plate and a vertically arranged lower connecting rod below the moving plate. The upper end of the lower connecting rod is fixedly connected to the center of the moving plate, and the lower end of the lower connecting rod is connected to the upper end of the seed crystal rod. Several springs are provided between the moving plate and the connecting disk, and all springs are evenly distributed along the circumference. The lower surface of the moving plate is an inclined plane that slopes outward and upward from the center of the moving plate, and several guide grooves are provided on the lower surface of the moving plate. All guide grooves are evenly distributed and arranged radially along the moving plate.

[0008] The adjustment mechanism includes a horizontally arranged circular support plate and a vertically arranged connecting cylinder above the support plate. The lower end of the connecting cylinder is fixedly connected to the support plate. A second connecting hole corresponding to the first connecting hole of the connecting plate is provided above the connecting cylinder to facilitate fixing the connecting plate and the connecting cylinder with fixing screws. The support plate has a through hole in the center for the lower connecting rod to pass through. The through hole is larger than the lower connecting rod. The support plate has an adjustment block corresponding to the guide groove. The adjustment block is wedge-shaped to cooperate with the guide groove. The connecting cylinder has a threaded hole corresponding to the adjustment block. One end of the adjustment screw passes through the threaded hole and is fixed to the adjustment block.

[0009] Meanwhile, steel balls are provided between the connecting plate and the moving plate, and arc-shaped grooves corresponding to the steel balls are provided at the center of the lower surface of the connecting plate and the upper surface of the moving plate to position the steel balls; the adjustment specifically includes the following steps: (1) A reference piece is placed below the seed crystal rod, and the reference piece is placed at the center hole of the furnace; (2) Start the motor and make it rotate at a speed of less than 10 r / min; (3) Observe the deviation between the rotation trajectory of the seed crystal rod and the reference piece, and turn off the motor at the point where the deviation is the largest; (4) Tighten the adjusting screws in the opposite direction to bring the adjusting block closer to the center, and then repeat steps (2) and (3); (5) Repeat steps (2)-(4) until the deflection amplitude at the end of the seed crystal rod is ≤0.1mm.

[0010] Furthermore, there are four guide grooves; at the same time, the support plate is provided with sliding grooves that correspond one-to-one with the adjusting blocks.

[0011] Furthermore, the upper surface of the movable plate and the lower surface of the connecting plate are respectively provided with slots corresponding to the springs, and the two ends of the springs are respectively locked in the slots of the movable plate and the connecting plate.

[0012] Furthermore, the upper connecting mechanism is connected to the motor shaft via an upper clamping mechanism. The upper clamping mechanism includes a first collet and a first locking nut. The first collet and the first locking nut are sleeved on the motor shaft and located at the lower end of the motor shaft. The upper end of the upper connecting rod has a first conical cavity at its center to accommodate the motor shaft and the first collet. The upper outer wall of the upper connecting rod has an external thread that mates with the first locking nut. The motor shaft and the first collet are inserted into the first conical cavity, and the first locking nut is threadedly fixed to the upper connecting rod, thereby fixing the upper connecting structure to the lower end of the motor shaft.

[0013] Furthermore, the lower connecting mechanism is connected to the seed crystal rod via a lower clamping mechanism. The lower clamping mechanism includes a second collet and a second locking nut. The second collet and the second locking nut are sleeved on the seed crystal rod and located at the upper end of the seed crystal rod. The lower end of the lower connecting rod has a second conical cavity at its center to accommodate the seed crystal rod and the second collet. The lower end of the lower connecting rod has an external thread that mates with the second locking nut. The seed crystal rod and the second collet are inserted into the second conical cavity, and the second locking nut is threadedly fixed to the lower connecting rod, thereby fixing the seed crystal rod at the lower end of the lower connecting rod.

[0014] Further, in step (1), the reference piece is disc-shaped and placed horizontally at the center hole of the furnace, the center of the reference piece corresponds to the center of the furnace, and the upper surface of the reference piece has two radially arranged and mutually perpendicular scale lines.

[0015] Furthermore, in step (2), the rotational speed is 5 r / min.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention, through a process of low-speed rotation, observation of deviation, and reverse fine-tuning, can significantly reduce reliance on operator experience, reduce human error, and effectively improve the efficiency of single crystal growth.

[0017] 2. This invention achieves precise control of the radial position of the seed crystal rod by adjusting screws, adjusting blocks, and guide grooves, combined with the positioning and guiding function of steel balls, ensuring that the sway amplitude is stably controlled within 0.1mm. This effectively avoids crystal defects caused by eccentric growth. Simultaneously, the "locking nut + collet" clamping design and spring preload structure ensure extreme reliability and anti-loosening properties of the connection during high-speed rotation and long-cycle growth, fundamentally guaranteeing the stability and consistency of the crystal growth process.

[0018] 3. In this invention, the upper connecting mechanism and the motor shaft are connected and fixed by an upper clamping mechanism, which has a load-bearing capacity of up to 70 kg, meeting the needs of industrial growth of large-size, high-quality crystals. Furthermore, the lower connecting mechanism, through the close cooperation between the evenly distributed guide grooves at its lower circumference and the wedge-shaped adjusting block, effectively resists the influence of centrifugal force during high-speed rotation, enabling the entire system to operate stably at a maximum speed of 500 r / min, significantly broadening the process applicability of this centering mechanism. Attached Figure Description

[0019] Figure 1 - A schematic diagram of the adjustment device in this invention.

[0020] Figure 2 - A schematic diagram of the adjusting mechanism.

[0021] Figure 3 -Structural diagram of the lower connecting mechanism Wherein: 1-seed crystal rod; 2-second collet; 3-second locking nut; 4-lower connecting rod; 5-support plate; 6-moving plate; 7-adjusting block; 8-adjusting screw; 9-spring; 10-steel ball; 11-connecting cylinder; 12-fixing screw; 13-upper connecting rod; 14-connecting disc; 15-first locking nut; 16-first collet; 17-motor shaft; 18-guide groove. Detailed Implementation

[0022] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0023] In traditional single-crystal growth equipment, the seed crystal rod is typically connected to the motor shaft via a simple mechanical connection. Centering relies heavily on manual experience, using simple structures like shims and screws for rough adjustments. This type of structure lacks a fine-tuning mechanism, making high-precision centering difficult and prone to seed crystal rod eccentricity during crystal growth, leading to crystal growth defects or even failure. Furthermore, under prolonged high-temperature, high-speed rotation, traditional clamping mechanisms are prone to loosening, causing center deviation and affecting the continuity and consistency of crystal growth. Additionally, with the increasing demand for large-size, high-quality single crystals, the seed crystal rod and its connecting mechanism must withstand greater weight and higher rotational speeds. Traditional structures struggle to meet the requirements of loads exceeding 70kg and high-speed rotations exceeding 500r / min. Moreover, existing centering mechanisms often require manual adjustment after machine shutdown, which is cumbersome, inefficient, and lacks dynamic fine-tuning capabilities, impacting production efficiency and crystal quality.

[0024] Based on this, the present invention provides a seed crystal rod centering method, which uses a centering device for adjustment. The specific structure of the centering device is described in [reference needed]. Figure 1 , Figure 2 and Figure 3 The device includes a motor, an upper connecting mechanism, an adjusting mechanism, a lower connecting mechanism, and a seed crystal rod 1. The motor shaft 17 is vertically arranged. The upper connecting mechanism is located below the motor shaft 17 and connected to the motor shaft 17. The adjusting mechanism is located below the upper connecting mechanism and connected to the upper connecting mechanism. The lower connecting mechanism is located below the adjusting mechanism and connected to the adjusting mechanism. The seed crystal rod 1 is vertically arranged below the lower connecting mechanism and connected to the lower connecting mechanism. The adjusting mechanism is used to adjust the position of the seed crystal rod 1 so that the seed crystal rod 1 is concentrically arranged with the motor shaft 17.

[0025] The upper connecting mechanism includes a horizontally arranged connecting plate 14 and an upper connecting rod 13 vertically arranged above the connecting plate 14. The lower end of the upper connecting rod 13 is fixedly connected to the center of the connecting plate 14, and the upper end of the upper connecting rod 13 is connected to the lower end of the motor shaft 17. A plurality of first connecting holes are evenly distributed on the connecting plate 14.

[0026] The lower connecting mechanism includes a horizontally arranged circular movable plate 6 and a vertically arranged lower connecting rod 4 below the movable plate 6. The upper end of the lower connecting rod 4 is fixedly connected to the center of the movable plate 6, and the lower end of the lower connecting rod 4 is connected to the upper end of the seed crystal rod 1. Several springs 9 are provided between the movable plate 6 and the connecting disk 14, and all springs 9 are evenly distributed along the circumference. The lower surface of the movable plate 6 is an inclined surface that slopes outward and upward from the center of the movable plate 6, and four guide grooves 18 are provided on the lower surface of the movable plate 6. All guide grooves 18 are evenly distributed and arranged radially along the movable plate 6.

[0027] The adjustment mechanism includes a horizontally arranged circular support plate 5 and a vertically arranged connecting cylinder 11 above the support plate 5. The lower end of the connecting cylinder 11 is fixedly connected to the support plate 5. A second connecting hole corresponding to the first connecting hole of the connecting plate 14 is provided above the connecting cylinder 11 to facilitate fixing the connecting plate 14 and the connecting cylinder 11 with the fixing screw 12. The support plate 5 has a through hole in the center for the lower connecting rod 4 to pass through. The through hole is larger than the lower connecting rod 4. The support plate 5 has an adjustment block 7 corresponding to the guide groove 18. The adjustment block 7 is wedge-shaped to cooperate with the guide groove 18. At the same time, the support plate 5 has a sliding groove corresponding to the adjustment block 7. The connecting cylinder 11 has a threaded hole corresponding to the adjustment block 7. One end of the adjustment screw 8 passes through the threaded hole and is fixed to the adjustment block 7 to move the adjustment block 7 by adjusting the screw 8.

[0028] Meanwhile, a steel ball 10 is provided between the connecting plate 14 and the moving plate 6. An arc-shaped groove corresponding to the steel ball 10 is provided at the center of the lower surface of the connecting plate 14 and the upper surface of the moving plate 6 to position the steel ball 10. A corresponding slot for the spring 9 is provided on the upper surface of the moving plate 6 and the lower surface of the connecting plate 14, with both ends of the spring 9 respectively engaged in the slots of the moving plate 6 and the connecting plate 14. Adjustment specifically includes the following steps: (1) A reference piece is placed below the seed crystal rod, and the reference piece is placed at the center hole of the furnace; (2) Start the motor and make it rotate at a speed of less than 10 r / min; (3) Observe the deviation between the rotation trajectory of the seed crystal rod and the reference piece, and turn off the motor at the point where the deviation is the largest; (4) Tighten the adjusting screws in the opposite direction to bring the adjusting block closer to the center, and then repeat steps (2) and (3); (5) Repeat steps (2)-(4) until the deflection amplitude at the end of the seed crystal rod is ≤0.1mm.

[0029] In specific implementation, the upper connecting mechanism is connected to the motor shaft 17 through an upper clamping mechanism. The upper clamping mechanism includes a first collet 16 and a first locking nut 15. The first collet 16 and the first locking nut 15 are sleeved on the motor shaft 17 and located at the lower end of the motor shaft 17. The upper end center of the upper connecting rod 13 is provided with a first conical cavity to accommodate the motor shaft 17 and the first collet 16. The upper outer wall of the upper connecting rod 13 is provided with an external thread that mates with the first locking nut 15. The motor shaft 17 and the first collet 16 are inserted into the first conical cavity, and the first locking nut 15 is threadedly fixed to the upper connecting rod 13, thereby realizing the fixed connection between the upper connecting rod 13 and the motor shaft 17.

[0030] In specific implementation, the lower connecting mechanism is connected to the seed crystal rod 1 through the lower clamping mechanism. The lower clamping mechanism includes a second collet 2 and a second locking nut 3. The second collet 2 and the second locking nut 3 are sleeved on the seed crystal rod 1 and located at the upper end of the seed crystal rod 1. The lower end center of the lower connecting rod 4 is provided with a second conical cavity to accommodate the seed crystal rod 1 and the second collet 2. The lower end outer wall of the lower connecting rod 4 is provided with an external thread that mates with the second locking nut 3. The seed crystal rod 1 and the second collet 2 are inserted into the second conical cavity, and the second locking nut 3 is threadedly fixed to the lower connecting rod 4, thereby fixing the seed crystal rod 1 to the lower end of the lower connecting rod 4.

[0031] In specific implementation, in step (1), the reference piece is disc-shaped and placed horizontally at the center hole of the furnace. The center of the reference piece corresponds to the center of the furnace, and the upper surface of the reference piece has two radially arranged and mutually perpendicular scale lines.

[0032] In specific implementation, the rotation speed in step (2) is 5 r / min.

[0033] During production, the assembly method of the above-mentioned centering device is as follows: First, the adjusting block is installed in the groove on the support plate. Then, the adjusting screw is installed and connected to the adjusting block. Next, the lower connecting rod of the lower connecting mechanism passes through the through hole on the support plate from top to bottom, so that the adjusting block is assembled in the guide groove below the moving plate. Then, the steel ball and spring are respectively installed into the arc groove and the slot on the moving plate. Then, the upper connecting mechanism is installed on the adjusting mechanism, so that the steel ball and spring are respectively located in the arc groove and the slot of the connecting plate. Then, it is fixed by fixing screws to fix the connecting plate and the connecting cylinder. Finally, the motor shaft and the upper connecting rod are connected by the upper clamping mechanism, and the lower connecting rod and the seed crystal rod are connected by the lower clamping mechanism.

[0034] Finally, it should be noted that the above embodiments of the present invention are merely illustrative examples and not intended to limit the implementation of the invention. Those skilled in the art can make other variations and modifications based on the above description. It is impossible to exhaustively list all possible implementations here. All obvious variations or modifications derived from the technical solutions of this invention are still within the scope of protection of this invention.

Claims

1. A method for centering a seed crystal rod, characterized in that, The adjustment is performed using an adjustment device, which includes a motor, an upper connecting mechanism, an adjustment mechanism, a lower connecting mechanism, and a seed crystal rod; both the motor shaft and the seed crystal rod are vertically arranged. The upper connecting mechanism includes a horizontally arranged connecting plate and a vertically arranged upper connecting rod above the connecting plate. The lower end of the upper connecting rod is fixedly connected to the center of the connecting plate, and the upper end of the upper connecting rod is connected to the lower end of the motor shaft. A plurality of first connecting holes are evenly distributed on the connecting plate. The lower connecting mechanism includes a horizontally arranged circular moving plate and a vertically arranged lower connecting rod below the moving plate. The upper end of the lower connecting rod is fixedly connected to the center of the moving plate, and the lower end of the lower connecting rod is connected to the upper end of the seed crystal rod. Several springs are provided between the moving plate and the connecting plate, and all springs are evenly distributed along the circumference. The lower surface of the moving plate is an inclined plane that slopes outward and upward from the center of the moving plate, and several guide grooves are provided on the lower surface of the moving plate. All guide grooves are evenly distributed and arranged radially along the moving plate. The adjustment mechanism includes a horizontally arranged circular support plate and a vertically arranged connecting cylinder above the support plate. The lower end of the connecting cylinder is fixedly connected to the support plate. A second connecting hole corresponding to the first connecting hole of the connecting plate is provided above the connecting cylinder to facilitate fixing the connecting plate and the connecting cylinder with fixing screws. The support plate has a through hole in the center for the lower connecting rod to pass through. The through hole is larger than the lower connecting rod. The support plate has an adjustment block corresponding to the guide groove. The adjustment block is wedge-shaped to cooperate with the guide groove. The connecting cylinder has a threaded hole corresponding to the adjustment block. One end of the adjustment screw passes through the threaded hole and is fixed to the adjustment block. Meanwhile, steel balls are provided between the connecting plate and the moving plate, and arc-shaped grooves corresponding to the steel balls are provided at the center of the lower surface of the connecting plate and the upper surface of the moving plate to position the steel balls; the adjustment specifically includes the following steps: (1) A reference piece is placed below the seed crystal rod, and the reference piece is placed at the center hole of the furnace; (2) Start the motor and make it rotate at a speed of less than 10 r / min; (3) Observe the deviation between the rotation trajectory of the seed crystal rod and the reference piece, and turn off the motor at the point where the deviation is the largest; (4) Tighten the adjusting screws in the opposite direction to bring the adjusting block closer to the center, and then repeat steps (2) and (3); (5) Repeat steps (2)-(4) until the deflection amplitude at the end of the seed crystal rod is ≤0.1mm.

2. The seed crystal rod centering method according to claim 1, characterized in that, There are four guide grooves; at the same time, the support plate is provided with sliding grooves that correspond one-to-one with the adjusting blocks.

3. The seed crystal rod centering method according to claim 1, characterized in that, The upper surface of the moving plate and the lower surface of the connecting plate are respectively provided with slots corresponding to the springs, and the two ends of the springs are respectively locked in the slots of the moving plate and the connecting plate.

4. A seed crystal rod centering method according to claim 1, 2 or 3, characterized in that, The upper connecting mechanism is connected to the motor shaft via an upper clamping mechanism. The upper clamping mechanism includes a first collet and a first locking nut. The first collet and the first locking nut are sleeved on the motor shaft and located at the lower end of the motor shaft. The upper end of the upper connecting rod has a first conical cavity at its center to accommodate the motor shaft and the first collet. The upper end of the upper connecting rod has an external thread that mates with the first locking nut. The motor shaft and the first collet are inserted into the first conical cavity, and the first locking nut is threadedly fixed to the upper connecting rod, thereby fixing the upper connecting structure to the lower end of the motor shaft.

5. A seed crystal rod centering method according to claim 1, 2, or 3, characterized in that, The lower connecting mechanism is connected to the seed crystal rod via a lower clamping mechanism. The lower clamping mechanism includes a second collet and a second locking nut. The second collet and the second locking nut are sleeved on the seed crystal rod and located at the upper end of the seed crystal rod. The lower end of the lower connecting rod has a second conical cavity at its center to accommodate the seed crystal rod and the second collet. The lower end of the lower connecting rod has an external thread that mates with the second locking nut. The seed crystal rod and the second collet are inserted into the second conical cavity. The second locking nut is threadedly fixed to the lower connecting rod, thereby fixing the seed crystal rod at the lower end of the lower connecting rod.

6. The seed crystal rod centering method according to claim 1, characterized in that, In step (1), the reference piece is disc-shaped and placed horizontally at the center hole of the furnace. The center of the reference piece corresponds to the center of the furnace, and the upper surface of the reference piece has two radially arranged and mutually perpendicular scale lines.

7. The seed crystal rod centering method according to claim 1, characterized in that, In step (2), the rotation speed is 5 r / min.

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