Automatic feeding single crystal furnace and control method thereof
The automatic feeding single crystal furnace utilizes a control unit and gas regulation mechanism to achieve automatic feeding, solving the problems of untimely or excessive feeding in traditional single crystal furnaces, improving production efficiency and crystal growth stability, and ensuring the safety and purity of the growth environment.
Patent Information
- Application Number
- CN202511712527.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-20
- Publication Date
- 2026-03-03
AI Technical Summary
In traditional single crystal furnaces, the timing of feeding relies on manual experience, which can lead to untimely or excessive feeding. During the feeding process, the crystal growth environment can be easily damaged, and splashing of the solution in the crucible can damage the equipment and threaten the safety of the operators.
The single crystal furnace with automatic feeding determines the feeding timing based on the crystal rod weight signal through the control unit, and realizes automatic feeding by using the feeding mechanism and gas regulation mechanism. The growth environment is protected by inert gas, and a blockage detection and removal mechanism is set up to ensure the automation and stability of feeding.
Automated feeding was achieved, which improved production efficiency, reduced interference with the crystal growth environment, avoided equipment damage and safety risks, and ensured the stability and quality of crystal growth.
Smart Images
Figure CN121593166A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of single crystal growth equipment technology, and in particular to an automatic feeding single crystal furnace and its control method. Background Technology
[0002] In traditional single-crystal furnace technology, determining when to add material relies primarily on manual experience and intermittent observation. Workers need to open the furnace at specific times to observe and determine if material needs to be added. When material addition is required, the entire growth process must be paused, the furnace opened, and some simple protective measures are taken to ensure a relatively stable crystal growth environment. However, these measures are only partially effective in preventing molten metal from splashing from the crucible.
[0003] Because the growth of crystals is difficult to observe directly during operation in a single crystal furnace, it is challenging to determine the appropriate timing for feeding, which can easily lead to untimely or excessive feeding. Furthermore, each feeding requires pausing the process and reopening the furnace, which not only reduces production efficiency but may also disrupt the stable environment for crystal growth, affecting crystal quality. In addition, during feeding, the solution inside the crucible can easily splash, potentially damaging the equipment and even endangering operator safety. Summary of the Invention
[0004] In order to solve the technical problems in the prior art, this application provides an automatic feeding single crystal furnace.
[0005] The automatic feeding single crystal furnace provided in this application adopts the following technical solution: An automatically fed single crystal furnace, comprising: The single crystal furnace body includes a crucible and a shell covering the crucible; The feeding mechanism includes a feeding bin, a feeding pipe with both ends connected to the bottom of the feeding bin and the inside of the crucible, respectively, and a first control valve for controlling the opening and closing of the feeding pipe; A pulling mechanism includes a pulling assembly for pulling the crystal ingot in a direction away from the crucible and a first sensor for detecting the weight of the crystal ingot. The control unit is configured to: receive the crystal rod weight signal transmitted by the first sensor, determine the growth rate of the crystal rod based on the crystal rod weight signal, and then determine whether the crucible needs to be filled with material. When it is determined that the material needs to be filled with material, the control unit controls the first control valve to open so that the material in the feeding hopper is transported to the crucible through the feeding pipe.
[0006] By adopting the above technical solution, the material in the feeding bin can be transported to the crucible through the feeding pipe. At the same time, the control unit can receive the signal transmitted by the first sensor and determine whether the crucible needs to be filled according to the growth rate of the crystal rod. If the material needs to be filled, the first control valve is opened so that the material in the feeding bin can be transported to the crucible, thus achieving the effect of automatic feeding.
[0007] Preferably, the feeding mechanism further includes a main hopper whose bottom is connected to the conveying hopper pipe. The conveying hopper is equipped with a second sensor for detecting the material level inside the conveying hopper. The main hopper is equipped with a second control valve for controlling its discharge. Both the second control valve and the second sensor are communicatively connected to the control unit.
[0008] By adopting the above technical solution, the main silo is used to store materials, and at the same time, the conveying silo is initially isolated from the environment outside the main silo. When the control unit senses and receives a signal from the second sensor that the material level is lower than the preset value, it controls the second control valve to open, so that the main silo can replenish materials into the conveying silo.
[0009] Preferably, the single crystal furnace further includes a gas regulating mechanism, which includes an inert gas source, a first gas supply pipe with its two ends respectively connected to the inert gas source and the material conveying hopper, and a third control valve for controlling the opening and closing of the first gas supply pipe. The third control valve is communicatively connected to the control unit, and the material conveying hopper is also equipped with a one-way gas outlet valve for discharging gas.
[0010] By adopting the above technical solution, since the air outside the main material hopper will pollute the crystal growth environment, before the single crystal furnace starts working, the second control valve is closed, and the first and third control valves are both opened. The inert gas source delivers inert gas into the material conveying hopper, and the inert gas discharges the air in the material conveying pipe and the material conveying hopper. After the main material hopper has replenished the material to the material conveying hopper, the first and second control valves are closed, and inert gas is delivered into the material conveying hopper to discharge the air entrained in the main material hopper during material discharge.
[0011] Preferably, the gas regulating mechanism further includes a second gas supply pipe with one end connected to the inert gas source and the other end connected to the material supply pipe, and a fourth control valve for controlling the on / off state of the second gas supply pipe, the fourth control valve being communicatively connected to the control unit.
[0012] By adopting the above technical solution, when the first control valve is in the open state, if the second sensor does not sense that the material in the conveying hopper has not descended for a long time, the control unit determines that the discharge pipe is blocked, and then controls the fourth control valve and the first control valve to open. The inert gas source inputs inert gas into the conveying pipe, and the inert gas impacts the material in the conveying pipe, thereby preventing the conveying pipe from being blocked.
[0013] Preferably, the conveying pipe extends downward at an angle from the bottom of the conveying hopper, with one end of the conveying pipe away from the conveying hopper close to the inner wall of the crucible, and the second gas conveying pipe is connected to the end of the conveying pipe close to the conveying hopper.
[0014] By adopting the above technical solution, the material in the feed pipe can be fed into the crucible under the action of gravity. Since the crucible is rotating during the operation of the single crystal furnace, the crystal rod is located in the central area of the crucible, and the feed pipe is close to the inner wall of the crucible, so as to avoid the feed pipe disturbing the liquid surface at the location of the crystal rod.
[0015] Preferably, the single crystal furnace body further includes a water-cooled screen surrounding the crystal rod. The water-cooled screen includes a conical water inlet ring, a water outlet ring connected to the water inlet ring, a water inlet pipe connected to a cold water conveying component, and a water outlet pipe connected to a water storage component. The water inlet ring has an annular water inlet cavity, and the water outlet ring has an water outlet cavity. The water inlet cavity is located below the water outlet cavity, and a partition is provided between the water inlet cavity and the water outlet cavity. The partition has multiple water passage holes. The water inlet pipe passes through the partition and communicates with the water inlet cavity, and the water outlet pipe communicates with the water outlet cavity.
[0016] By adopting the above technical solution, the water-cooled screen is used to cool the crystal rod. The setting of the water inlet and water outlet simplifies the flow path of the cooling water, and at the same time, it enables the cooling water to fully fill the water inlet and water outlet, ensuring that the cooling water can evenly cover the entire heat exchange surface and avoid the occurrence of cooling dead zones.
[0017] This application also provides a control method for an automatically fed single crystal furnace, the method comprising the following steps: S1: The control unit continuously receives the crystal rod weight signal transmitted by the first sensing element and calculates the growth rate of the crystal rod accordingly. S2: The control unit controls the lifting rate of the lifting assembly according to the growth rate, and determines whether the crucible needs to be filled with material according to the growth rate; S3: When it is determined that material needs to be added, the control unit switches to the material adding state, controls the first control valve to open to perform material adding, and makes the lifting assembly run at a preset speed during material adding; S4: After the feeding is completed, the control unit controls the first control valve to close and switches to the post-feeding monitoring state. In the monitoring state, the growth rate of the crystal rod is continuously monitored within a preset monitoring period. S5: If the growth rate of the crystal rod is still lower than a preset threshold after the preset monitoring period ends, it is determined that the crystal growth is abnormal and a graded lifting adjustment program is started. If the growth rate of the crystal rod recovers to the normal range, it is switched back to the normal growth state.
[0018] By adopting the above technical solution, the disturbance to crystal growth caused by the feeding process is actively monitored and confirmed to have been recovered. If the growth rate fails to recover within a preset time period, a graded adjustment program can be initiated in a timely manner, rather than blindly continuing growth. This closed-loop control method effectively avoids crystal growth failure or quality degradation caused by feeding disturbances, significantly improving the stability and yield of the automated growth process.
[0019] Preferably, the graded lifting and adjustment procedure described in step S5 includes the following steps: S51: The control unit gradually reduces the lifting rate of the lifting component by a preset step size, and maintains an observation period after each reduction in rate to monitor the growth rate.
[0020] S52: If the growth rate returns to the normal range during the gradual reduction process, exit the program and switch back to the normal growth state.
[0021] S53: If the growth rate does not recover after the pulling rate drops to a preset minimum rate threshold, the pulling component is reversed to lower the crystal rod by a preset distance to remelt it in the melt. After remelting, the pulling is restarted at a preset recovery rate, and then the normal growth state is switched back.
[0022] By adopting the above technical solution, growth can be restored by gradually reducing the lifting rate, which has a smaller impact. If successful, this can avoid process interruption and save time and costs.
[0023] Preferably, step S3 further includes an automatic feeding and purification process, which includes the following steps: S31: The control unit continuously monitors the material level signal inside the conveying hopper transmitted by the second sensor; S32: When the material level is lower than a preset value, the control unit controls the first control valve and the third control valve to be closed, and at the same time controls the second control valve to open to replenish the material; S33: When the second sensor detects that the material level has reached the preset value, the control unit controls the second control valve to close and then opens the third control valve to allow the inert gas source to deliver inert gas into the material conveying bin to discharge air. S34: After running for a preset purification period, the control unit controls the third control valve to close and controls the first control valve to open to perform feeding.
[0024] By adopting the above technical solution, after replenishing materials in the main silo, the conveying silo is purged with inert gas, effectively removing air carried in from the main silo during replenishment. This ensures that no polluting gases such as oxygen are introduced during subsequent feeding into the crucible, thus protecting the purity of the melt and crystal growth environment.
[0025] Preferably, step S33 further includes a blockage clearing procedure, which includes the following steps: S331: When the control unit controls the first control valve to open to perform feeding, it simultaneously monitors the signal of the second sensor; S332: If the second sensor does not detect a drop in material level within a preset time period after the first control valve is opened, the control unit determines that the conveying pipe is blocked; S333: When a blockage is detected, the control unit keeps the first control valve open and controls the fourth control valve to open, so that the inert gas source inputs high-pressure inert gas into the feed pipe through the second gas supply pipe to clear the blockage; S334: After a preset jetting period, the control unit controls the fourth control valve to close.
[0026] By adopting the above technical solution, changes in the material level sensor can be monitored during feeding to determine whether the conveying pipe is blocked. Once a blockage is detected, the control unit will use the fourth control valve and the second air supply pipe to deliver high-pressure inert gas into the conveying pipe to automatically clear the blockage. This avoids feeding interruptions and manual intervention caused by material blockage, improving the reliability and continuity of the entire automatic feeding system.
[0027] In summary, this application includes at least one of the following beneficial technical effects: 1. The material in the feeding bin can be transported to the crucible through the feeding pipe. At the same time, the control unit can receive the signal transmitted by the first sensor and determine whether the crucible needs to be filled according to the growth rate of the crystal rod. If the material needs to be filled, the first control valve is opened so that the material in the feeding bin can be transported to the crucible, thus achieving the effect of automatic feeding.
[0028] 2. Since the air outside the main material hopper can pollute the crystal growth environment, before the single crystal furnace starts working, the second control valve is closed, and the first and third control valves are both opened. The inert gas source supplies inert gas into the material conveying hopper. The inert gas discharges the air in the material conveying pipe and the material conveying hopper. After the main material hopper has replenished the material to the material conveying hopper, the first and second control valves are closed, and inert gas is supplied into the material conveying hopper to discharge the air entrained in the main material hopper during material discharge.
[0029] 3. When the first control valve is open, if the second sensor does not detect that the material in the conveying hopper has not decreased for a long time, the control unit determines that the discharge pipe is blocked, and then controls the fourth control valve and the first control valve to open. The inert gas source inputs inert gas into the conveying pipe. The inert gas impacts the material in the conveying pipe, thereby preventing the conveying pipe from becoming blocked. Attached Figure Description
[0030] Figure 1 This is a schematic diagram of the structure of an automatic feeding single crystal furnace provided in one embodiment of this application; Figure 2 yes Figure 1 Enlarged view of region A in the middle; Figure 3 yes Figure 1 Enlarged view of region B in the middle; Explanation of reference numerals in the attached drawings: 1. Single crystal furnace body; 11. Crucible; 12. Shell; 13. Water-cooled screen; 131. Water inlet ring; 1311. Water inlet cavity; 132. Water outlet ring; 1321. Water outlet cavity; 133. Water inlet pipe; 134. Water outlet pipe; 135. Cold water conveying component; 136. Water storage component; 137. Partition plate; 1371. Water passage hole; 2. Feeding mechanism; 21. Feeding bin; 211. Second 212. Sensing element; 22. One-way gas outlet valve; 23. Material conveying pipe; 24. First control valve; 25. Main material bin; 26. Second control valve; 27. Lifting mechanism; 38. Lifting assembly; 39. First sensing element; 20. Control unit; 21. Gas regulating mechanism; 22. Inert gas source; 23. First gas conveying pipe; 24. Third control valve; 25. Second gas conveying pipe; 26. Fourth control valve; 27. Crystal rod. Detailed Implementation
[0031] The following is in conjunction with the appendix Figures 1-3 This application will be described in further detail.
[0032] Please see Figure 1 , Figure 1 This is a schematic diagram of the structure of an automatic feeding single crystal furnace provided in one embodiment of this application. The automatic feeding single crystal furnace provided in the first embodiment of this application includes a single crystal furnace body 1, a feeding mechanism 2, a lifting mechanism 3, and a control unit 4. The single crystal furnace body 1, the feeding mechanism 2, and the lifting mechanism 3 are all communicatively connected to the control unit 4. The control unit 4 can determine whether it is necessary to add material to the crucible 11 based on the weight signal of the crystal rod 6 detected by the lifting mechanism 3, and then control the feeding mechanism 2 to add material to the crucible 11, thereby realizing automatic feeding and avoiding the problems of inaccurate manual judgment of the feeding time and damage to the crystal growth environment during the feeding process.
[0033] Please refer to the following: Figure 2 , Figure 2 yes Figure 1Enlarged view of area A; the single crystal furnace body 1 includes a crucible 11 and a shell 12 covering the crucible 11. The crucible 11 is used to contain materials, while the shell 12 serves to protect and isolate the materials, preventing external factors from interfering with crystal growth. The crucible 11 is generally made of a material with high temperature resistance and good chemical stability, such as quartz; the shell 12 can be made of metal material, possessing certain strength and sealing properties. In this embodiment, the single crystal furnace body 1 also includes a water-cooled screen 13 surrounding the crystal rod 6. The water-cooled screen 13 includes a conical water inlet ring 131, a water outlet ring 132 connected to the water inlet ring 131, a water inlet pipe 133 connected to the cold water conveying component 135, and a water outlet pipe 134 connected to the water storage component 136.
[0034] The inlet ring 131 has an annular inlet cavity 1311, and the outlet ring 132 has an outlet cavity 1321. The inlet cavity 1311 is located below the outlet cavity 1321, and a partition 137 is provided between the inlet cavity 1311 and the outlet cavity 1321. The partition 137 has multiple water passages 1371, which form uniformly distributed vertical channels. The channels penetrate the corresponding cavity areas of the inlet cavity 1311 and the outlet cavity 1321. The inlet pipe 133 passes through the partition 137 and communicates with the inlet cavity 1311, and the outlet pipe 134 communicates with the outlet cavity 1321. The water-cooled screen 13 is used to cool the crystal rod 6. Its conical structure and internal cavity design simplify the flow path of the cooling water and ensure that the cooling water can uniformly cover the entire heat exchange surface, effectively avoiding cooling dead zones and improving cooling efficiency and crystal quality.
[0035] During the operation of the water-cooled screen 13, cooling water enters the inlet chamber 1311 from the bottom through the inlet pipe 133, and then flows rapidly upward through the vertical channels formed by multiple water passages 1371 of the baffle 137, finally converging at the top outlet chamber 1321 and being discharged through the outlet pipe 134. The vertical channel design increases the flow rate of the cooling water and the contact area between the cooling water and the main body of the water-cooled screen 13, thereby improving heat exchange efficiency and enabling a more efficient turbulent flow state. The porous structure ensures uniform water flow distribution, effectively eliminating the problem of local overheating in traditional water-cooled screens 13, avoiding the formation of cooling dead zones, and ensuring a stable temperature environment for crystal growth. The inlet ring 131 and outlet ring 132 can be made of copper alloy instead of stainless steel to fully utilize the excellent thermal conductivity of copper alloy. The aperture of the interconnected porous structure can be adjusted within the range of 5-8mm to adapt to different flow requirements and optimize flow resistance. As an optimization solution, a fin structure can be added to the outside of the water-cooled screen 13 to further improve cooling efficiency by increasing the heat dissipation area; or high thermal conductivity ceramic particles can be embedded in the porous interconnected structure to enhance local heat conduction performance.
[0036] The feeding mechanism 2 includes a feeding bin 21, a feeding pipe 22, and a first control valve 23. The feeding bin 21 is used to store the material to be conveyed. The two ends of the feeding pipe 22 are connected to the bottom of the feeding bin 21 and the inside of the crucible 11, respectively. The first control valve 23 is used to control the opening and closing of the feeding pipe 22. The feeding bin 21 can be cylindrical, square, etc., and its capacity is determined according to actual production needs. The feeding pipe 22 is usually pipe-shaped and can be made of stainless steel or other materials to ensure smooth material conveying. The first control valve 23 can be an electric valve, a pneumatic valve, etc., and is opened and closed by a signal from the control unit 4.
[0037] In this embodiment, the feed pipe 22 extends downward at an angle from the bottom of the feed hopper 21. The end of the feed pipe 22 facing away from the feed hopper 21 is close to the inner wall of the crucible 11. The angled design of the feed pipe 22 allows the material in the feed pipe 22 to be smoothly and efficiently fed into the crucible 11 under the action of gravity, avoiding material residue in the feed pipe 22. At the same time, arranging the feed pipe 22 close to the inner wall of the crucible 11 can prevent the conveyed material from disturbing the liquid surface of the rotating crystal rod 6 located in the central region of the crucible 11 during the operation of the single crystal furnace, thus ensuring the stability of crystal growth.
[0038] Please refer to the following: Figure 3 , Figure 3 yes Figure 1 The enlarged view of area B shows that the feeding mechanism 2 also includes a main hopper 24 whose bottom is connected to the conveying hopper 21 via a pipe. The conveying hopper 21 is equipped with a second sensor 211 for detecting the material level inside the conveying hopper 21. The main hopper 24 is equipped with a second control valve 241 to control its discharge. Both the second control valve 241 and the second sensor 211 are communicatively connected to the control unit 4. The main hopper 24 is used to store a large amount of material, providing material replenishment to the conveying hopper 21, and simultaneously initially isolating the conveying hopper 21 from the environment outside the main hopper 24. The second sensor 211 can be a level switch or an ultrasonic level sensor, installed inside the conveying hopper 21 to monitor the material level in real time; the second control valve 241 can be an electric gate valve or a rotary valve, controlled by the control unit 4 to open and close.
[0039] When the control unit 4 receives a signal from the second sensor 211 indicating that the material level is lower than a preset value, it controls the second control valve 241 to open, allowing the main hopper 24 to replenish material into the conveying hopper 21. Once the material level in the conveying hopper 21 reaches the preset level, the second sensor 211 transmits a signal to the control unit 4, which then controls the second control valve 241 to close. The main hopper 24 increases the material storage capacity and reduces the need for frequent material replenishment. Through the cooperation of the second sensor 211 and the second control valve 241, automatic replenishment of material in the conveying hopper 21 is achieved, ensuring the continuous and stable operation of the feeding mechanism 2. The conveying hopper 21 in the feeding mechanism 2 is also equipped with a one-way vent valve 212 for discharging gas. The one-way vent valve 212 only allows gas to escape from the conveying hopper 21, preventing outside air from entering and thus protecting the cleanliness of the internal environment of the conveying hopper 21.
[0040] The lifting mechanism 3 includes a lifting assembly 31 and a first sensor 32. The lifting assembly 31 is used to lift the crystal ingot 6 away from the crucible 11, and the first sensor 32 is used to detect the weight of the crystal ingot 6. The lifting assembly 31 may consist of a motor, a transmission device, and a lifting rope, etc. The motor drives the lifting rope through the transmission device to lift the crystal ingot 6; the first sensor 32 may be a weighing sensor connected between the seed crystal holder and the lifting rope to detect the weight change of the crystal ingot 6 in real time.
[0041] The control unit 4 is configured to receive the weight signal of the crystal rod 6 transmitted by the first sensor 32, determine the growth rate of the crystal rod 6 based on the weight signal, and then determine whether material needs to be added to the crucible 11. When it is determined that material needs to be added, the control unit 4 controls the first control valve 23 to open, so that the material in the conveying bin 21 is conveyed to the crucible 11 through the conveying pipe 22. The control unit 4 can be a microcontroller, PLC, or other device with data processing and control functions, and can achieve precise control of each component through programming.
[0042] In this embodiment, the single crystal furnace also includes a gas regulating mechanism 5. The gas regulating mechanism 5 includes an inert gas source 51, a first gas supply pipe 52 with its two ends connected to the inert gas source 51 and the material conveying bin 21 respectively, and a third control valve 53 for controlling the opening and closing of the first gas supply pipe 52. The third control valve 53 is communicatively connected to the control unit 4. The inert gas source 51 can be a gas cylinder for storing inert gas or a gas generator to provide a stable supply of inert gas; the first gas supply pipe 52 is a pipe for conveying inert gas; the third control valve 53 can be an electric valve, a pneumatic valve, etc., and its opening and closing is controlled by the control unit 4.
[0043] The gas regulating mechanism 5 effectively protects the crystal growth environment. Before the single crystal furnace starts operating, the second control valve 241 is closed, while the first control valve 23 and the third control valve 53 are both open. The inert gas source 51 supplies inert gas to the feeding hopper 21, and the inert gas discharges the air from the feeding pipe 22 and the feeding hopper 21 through the one-way exhaust valve 212. This prevents external air from contaminating the crystal growth. After the main material hopper 24 replenishes the feeding hopper 21 with material, the first control valve 23 and the second control valve 241 are closed, and the third control valve 53 is opened again to supply inert gas to the feeding hopper 21 to expel the air entrained in the main material hopper 24 during material discharge. This further ensures the purity of the crystal growth environment during material transportation and improves the crystal growth quality.
[0044] The gas regulating mechanism 5 also includes a second gas supply pipe 54, one end of which is connected to the inert gas source 51 and the other end of which is connected to the conveying pipe 22, and a fourth control valve 55 for controlling the opening and closing of the second gas supply pipe 54. The fourth control valve 55 can be a fast-response pneumatic ball valve, and the fourth control valve 55 is communicatively connected to the control unit 4. The second gas supply pipe 54 is also pipe-shaped and is used to deliver inert gas into the conveying pipe 22. The fourth control valve 55 is controlled by the control unit 4 to open and close. When the first control valve 23 is in the open state, if the second sensor 211 does not sense the material drop in the conveying hopper 21 for a long time, the control unit 4 determines that the conveying pipe 22 is blocked.
[0045] At this time, the control unit 4 keeps the first control valve 23 open and controls the fourth control valve 55 to open. Inert gas source 51 inputs inert gas into the conveying pipe 22. The inert gas impacts the material in the conveying pipe 22, thereby achieving automatic unblocking and preventing blockage of the conveying pipe 22. This avoids feeding interruptions and manual intervention caused by material blockage, improving the reliability and continuity of the entire automatic feeding system. The second gas supply pipe 54 is connected to the end of the conveying pipe 22 near the conveying bin 21. This connection method facilitates the direct impact of high-pressure inert gas on the starting position of materials that may be blocked, improving unblocking efficiency.
[0046] The working principle of this embodiment is as follows: the coordinated operation of the feeding mechanism 2, the lifting mechanism 3, and the control unit 4 enables the single crystal furnace to automatically determine the timing of feeding and feed according to the growth status of the crystal rod 6, thereby improving production efficiency and the quality of crystal growth. By monitoring the weight of the crystal rod 6 in real time, the growth status of the crystal can be accurately grasped, avoiding errors and uncertainties caused by manual judgment. At the same time, the automatic feeding process does not require pausing the process or opening the single crystal furnace, reducing interference with the crystal growth environment and ensuring the stability of crystal growth.
[0047] Example 2 The automatic feeding control method for a single crystal furnace provided in this application embodiment is applied to the single crystal furnace in Embodiment 1 above. The method includes the following steps: S1: Before starting the single crystal furnace, a pre-purification procedure is performed. First, the control unit 4 confirms that the second control valve 241 is closed, and then controls both the first control valve 23 and the third control valve 53 to open. At this time, the inert gas source 51 continuously supplies inert gas into the feeding chamber 21. The inert gas creates positive pressure in the feeding chamber 21 and discharges all air from the feeding pipe 22 and the feeding chamber 21 through the one-way exhaust valve 212 on the feeding pipe 22 and the feeding chamber 21. This pre-purification step ensures that the internal environment of the feeding chamber 21 and the feeding pipe 22 has been replaced with high-purity inert gas before the entire feeding path connects to the inner cavity of the crucible 11, avoiding contamination of the crystal growth environment by external air or impurities.
[0048] Next, the control unit 4 continuously receives the weight signal of the crystal rod 6 transmitted by the first sensor 32, and calculates the growth rate of the crystal rod 6 accordingly. By processing the weight signal of the crystal rod 6 in real time, the control unit 4 can accurately calculate the weight change of the crystal rod 6 per unit time, thereby obtaining the growth rate of the crystal rod 6.
[0049] S2: The control unit 4 controls the pulling rate of the pulling assembly 31 according to the growth rate, and determines whether the crucible 11 needs to be filled with material based on the growth rate. The control unit 4 compares the growth rate of the crystal rod 6 with the set value according to the preset rules. When the growth rate is lower than the set value, it determines that material needs to be added. At the same time, the control unit 4 adjusts the pulling rate of the pulling assembly 31 according to the growth rate to ensure the normal growth of the crystal.
[0050] S3: When it is determined that material needs to be added, the control unit 4 switches to the material adding state, controls the first control valve 23 to open to perform material adding, and makes the lifting assembly 31 run at a preset rate during the material adding process. During the material adding process, the lifting assembly 31 runs at the preset rate to maintain the growth state of the crystal and avoid excessive impact on the crystal growth due to the material adding process.
[0051] Step S3 also includes an automatic feeding and purification process, which includes the following steps: S31: The control unit 4 continuously monitors the material level signal inside the conveying bin 21 transmitted by the second sensor 211.
[0052] S32: When the material level is lower than a preset value, the control unit 4 controls the first control valve 23 and the third control valve 53 to be closed, and at the same time controls the second control valve 241 to open to replenish the material.
[0053] S33: When the second sensor 211 detects that the material level has reached a preset value, the control unit 4 controls the second control valve 241 to close and then opens the third control valve 53, allowing the inert gas source 51 to supply inert gas into the conveying bin 21 to expel air. After a preset purification period, the control unit 4 controls the third control valve 53 to close and controls the first control valve 23 to open to perform feeding. After the main material bin 24 is replenished with material, the conveying bin 21 is purged with inert gas, effectively expelling the air carried in from the main material bin 24 during replenishment. This ensures that no polluting gases such as oxygen are introduced when feeding material into the crucible 11, thus protecting the purity of the melt and crystal growth environment.
[0054] Step S33 also includes a blockage removal procedure, which includes the following steps: S331: When the control unit 4 controls the first control valve 23 to open to perform feeding, it simultaneously monitors the signal of the second sensor 211.
[0055] S332: If the second sensor 211 does not detect a drop in material level within a preset time period after the first control valve 23 is opened, the control unit 4 determines that the conveying pipe 22 is blocked.
[0056] S333: When a blockage is detected, the control unit 4 keeps the first control valve 23 open and controls the fourth control valve 55 to open, so that the inert gas source 51 inputs high-pressure inert gas into the material conveying pipe 22 through the second gas supply pipe 54 to clear the blockage.
[0057] S334: After a preset jetting period, the control unit 4 closes the fourth control valve 55. Monitoring changes in the material level sensor during feeding allows the control unit 4 to determine if the conveying pipe 22 is blocked. If a blockage is detected, the control unit 4 uses the fourth control valve 55 and the second air supply pipe 54 to deliver high-pressure inert gas into the conveying pipe 22, automatically clearing the blockage. This avoids feeding interruptions and manual intervention due to material blockage, improving the reliability and continuity of the entire automatic feeding system.
[0058] S4: After feeding is completed, the control unit 4 controls the first control valve 23 to close and switches to the post-feeding monitoring state. In the monitoring state, the growth rate of the crystal rod 6 is continuously monitored within a preset monitoring period. By continuously monitoring the growth rate of the crystal rod 6 after feeding, the impact of the feeding process on crystal growth can be detected in a timely manner.
[0059] S5: If the growth rate of crystal rod 6 remains below a preset threshold after the preset monitoring period ends, it is determined to be an abnormal crystal growth, and a graded pulling adjustment program is initiated. If the growth rate of crystal rod 6 returns to the normal range, it switches back to normal growth. The graded pulling adjustment program includes the following steps: The graded lifting and adjustment procedure includes the following steps: S51: The control unit 4 gradually reduces the lifting rate of the lifting component 31 in a preset step size, and maintains an observation period after each reduction in rate to monitor the growth rate.
[0060] S52: If the growth rate returns to the normal range during the gradual reduction of the growth rate, exit this program and switch back to normal growth state.
[0061] S53: If the growth rate fails to recover after the pulling rate drops to a preset minimum rate threshold, the pulling assembly 31 is reversed, lowering the ingot 6 by a preset distance to remelt it in the melt. After remelting, the pulling process restarts at a preset recovery rate, then switches back to normal growth. This tiered pulling adjustment program can gradually adjust the pulling rate to restore growth based on the specific crystal growth conditions. This is a less disruptive approach; if successful, it avoids process interruptions, saving time and costs. If the adjustment is ineffective, a remelting and re-pulling strategy is adopted. Although this interrupts growth, it ensures the subsequent crystal quality, guaranteeing the stability and quality of crystal growth.
[0062] The implementation principle of this embodiment is as follows: This control method achieves precise control of the single crystal furnace feeding process by real-time monitoring and analysis of the growth rate of crystal rod 6. Monitoring the growth rate of crystal rod 6 before and after feeding can promptly detect abnormalities in the crystal growth process, and adjustments can be made through a graded pulling adjustment program to ensure the stability and quality of crystal growth. This closed-loop control method can actively monitor and confirm whether the disturbance to crystal growth caused by the feeding process has been recovered. If the growth rate fails to recover within a preset time period, the graded adjustment program can be initiated in a timely manner, instead of blindly continuing growth, effectively avoiding crystal growth failure or quality degradation caused by feeding disturbances, and significantly improving the stability and yield of the automated growth process.
[0063] The specific embodiments described above do not constitute a limitation on the scope of protection of this application. Any other corresponding changes and modifications made based on the technical concept of this application should be included within the scope of protection of this application.
Claims
1. An automatic feeding single crystal furnace, characterized in that, include: The single crystal furnace body (1) includes a crucible (11) and a shell (12) covering the crucible (11); The feeding mechanism (2) includes a feeding bin (21), a feeding pipe (22) with both ends connected to the bottom of the feeding bin (21) and the inside of the crucible (11) respectively, and a first control valve (23) for controlling the opening and closing of the feeding pipe (22); The lifting mechanism (3) includes a lifting assembly (31) for lifting the crystal rod (6) in a direction away from the crucible (11) and a first sensor (32) for detecting the weight of the crystal rod (6). The control unit (4) is configured to: receive the weight signal of the crystal rod (6) transmitted by the first sensing element (32), determine the growth rate of the crystal rod (6) based on the weight signal of the crystal rod (6), and then determine whether the crucible (11) needs to be filled with material. When it is determined that the material needs to be filled with material, the control unit (4) controls the first control valve (23) to open so that the material in the feeding bin (21) is transported to the crucible (11) through the feeding pipe (22).
2. The automatic feeding single crystal furnace according to claim 1, characterized in that, The feeding mechanism (2) also includes a main hopper (24) whose bottom is connected to the conveying hopper (21) via a pipe. The conveying hopper (21) is equipped with a second sensor (211) for detecting the material level inside the conveying hopper (21). The main hopper (24) is equipped with a second control valve (241) for controlling its discharge. The second control valve (241) and the second sensor (211) are both communicatively connected to the control unit (4).
3. The automatic feeding single crystal furnace according to claim 2, characterized in that, The single crystal furnace also includes a gas regulating mechanism (5), which includes an inert gas source (51), a first gas supply pipe (52) with its two ends connected to the inert gas source (51) and the material conveying bin (21) respectively, and a third control valve (53) for controlling the opening and closing of the first gas supply pipe (52). The third control valve (53) is communicatively connected to the control unit (4). The material conveying bin (21) is also equipped with a one-way gas outlet valve (212) for discharging gas.
4. The automatic feeding single crystal furnace according to claim 3, characterized in that, The gas regulating mechanism (5) further includes a second gas supply pipe (54) with one end connected to the inert gas source (51) and the other end connected to the material supply pipe (22), and a fourth control valve (55) for controlling the opening and closing of the second gas supply pipe (54). The fourth control valve (55) is communicatively connected to the control unit (4).
5. The automatic feeding single crystal furnace according to claim 4, characterized in that, The conveying pipe (22) extends downward at an angle from the bottom of the conveying bin (21), and the end of the conveying pipe (22) away from the conveying bin (21) is close to the inner wall of the crucible (11). The second gas conveying pipe (54) is connected to the end of the conveying pipe (22) close to the conveying bin (21).
6. The automatic feeding single crystal furnace according to claim 1, characterized in that, The single crystal furnace body (1) also includes a water-cooled screen (13) surrounding the crystal rod (6). The water-cooled screen (13) includes a conical water inlet ring (131), a water outlet ring (132) connected to the water inlet ring (131), a water inlet pipe (133) connected to the cold water conveying device (135), and a water outlet pipe (134) connected to the water storage device (136). The water inlet ring (131) is provided with a ring-shaped water inlet cavity (1311), and the water outlet ring (132) is provided with a conical water inlet cavity (1311). 2) A water outlet chamber (1321) is provided, the water inlet chamber (1311) is located below the water outlet chamber (1321), and a partition (137) is provided between the water inlet chamber (1311) and the water outlet chamber (1321). The partition (137) is provided with a plurality of water passage holes (1371). The water inlet pipe (133) passes through the partition (137) and communicates with the water inlet chamber (1311). The water outlet pipe (134) communicates with the water outlet chamber (1321).
7. A control method for an automatic feeding single crystal furnace, characterized in that, The method is applied to the single crystal furnace as described in claim 4, and the method includes the following steps: S1: The control unit (4) continuously receives the weight signal of the crystal rod (6) transmitted by the first sensing element (32) and calculates the growth rate of the crystal rod (6) accordingly. S2: The control unit (4) controls the lifting rate of the lifting component (31) according to the growth rate, and determines whether the crucible (11) needs to be filled according to the growth rate; S3: When it is determined that material needs to be added, the control unit (4) switches to the material adding state, controls the first control valve (23) to open to perform material adding, and makes the lifting assembly (31) run at a preset rate during material adding; S4: After the feeding is completed, the control unit (4) controls the first control valve (23) to close and switches to the post-feeding monitoring state. In the monitoring state, the growth rate of the crystal rod (6) is continuously monitored within a preset monitoring period. S5: If the growth rate of the crystal rod (6) is still lower than a preset threshold after the preset monitoring period ends, it is determined that the crystal growth is abnormal and a graded lifting adjustment program is started. If the growth rate of the crystal rod (6) returns to the normal range, it is switched back to the normal growth state.
8. The control method for an automatic feeding single crystal furnace according to claim 7, characterized in that, The graded lifting and adjustment procedure described in step S5 includes the following steps: S51: The control unit (4) gradually reduces the lifting rate of the lifting component (31) in a preset step size, and maintains an observation period after each reduction in rate to monitor the growth rate; S52: If the growth rate returns to the normal range during the gradual reduction process, exit this program and switch back to the normal growth state. S53: If the growth rate does not recover after the pulling rate is reduced to a preset minimum rate threshold, the pulling component (31) is reversed to lower the crystal rod (6) by a preset distance to remelt it in the melt, and after remelting, the pulling is restarted at a preset recovery rate, and then switched back to the normal growth state. According to claim 8, the control method for an automatic feeding single crystal furnace is characterized in that step S3 further includes an automatic feeding and purification procedure, the automatic feeding and purification procedure including the following steps: S31: The control unit (4) continuously monitors the material level signal inside the conveying bin (21) transmitted by the second sensor (211); S32: When the material level is lower than a preset value, the control unit (4) controls the first control valve (23) and the third control valve (53) to be closed, and at the same time controls the second control valve (241) to open to replenish the material; S33: When the second sensing element (211) senses that the material level has reached the preset value, the control unit (4) controls the second control valve (241) to close and then opens the third control valve (53) so that the inert gas source (51) delivers inert gas into the material conveying bin (21) to discharge air. S34: After running for a preset purification period, the control unit (4) controls the third control valve (53) to close and controls the first control valve (23) to open to perform feeding.
9. The control method for an automatic feeding single crystal furnace according to claim 9, characterized in that, Step S33 further includes a blockage removal procedure, which includes the following steps: S331: When the control unit (4) controls the first control valve (23) to open to perform feeding, it simultaneously monitors the signal of the second sensor (211); S332: If the second sensor (211) does not detect a drop in material level within a preset time period after the first control valve (23) is opened, the control unit (4) determines that the conveying pipe (22) is blocked; S333: When a blockage is detected, the control unit (4) keeps the first control valve (23) open and controls the fourth control valve (55) to open, so that the inert gas source (51) inputs high-pressure inert gas into the material conveying pipe (22) through the second gas delivery pipe (54) to clear the blockage; S334: After a preset jetting period, the control unit (4) controls the fourth control valve (55) to close.