Method for optimizing automatic crucible placing position system based on liquid temperature difference compensation

Abstract

The invention discloses an automatic crucible placing position system optimization method based on liquid temperature difference compensation, and relates to the technical field of single crystal silicon rod drawing. The optimization method comprises the following steps: when a single crystal silicon rod is drawn, after a silicon material is completely melted and a guide cylinder reaches a lower limit, triggering automatic crucible lifting, gradually lifting the crucible by calculating an inverted crescent area of the guide cylinder, comparing an actual seeding liquid temperature value with a standard value (1450 DEG C) to obtain a deviation value, and calculating the actual seeding liquid temperature according to a preset rule, such as a liquid temperature deviation-10 DEG C compensation accurate measurement value 0.8 and the like. And compensating and adjusting the accurate measurement value of the liquid port distance, and automatically placing the crucible according to the adjusted numerical value. According to the method, the preset compensation rule is stored in the control module and is automatically called and adjusted, the placement concentration ratio of the liquid port distance can be increased to about + / -0.5, automatic chemical steps are perfected, the manual workload and the operation risk are reduced, the drainage and drainage survival rate is increased, and the production quality and safety of the silicon single crystal rod are guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of single crystal silicon rod drawing, and in particular to an automatic crucible placement system optimization method based on liquid temperature difference compensation. Background Art

[0002] In the single crystal silicon rod pulling process, seeding and shouldering is an extremely critical step. The seeding process requires slowly lowering the seed crystal fixed on a heavy hammer to the surface of the melt for preheating. The tip of the seed crystal is then allowed to contact the melt surface and partially melt to eliminate the damaged layer and contamination on the seed crystal surface and form a new solid-liquid interface. The seed crystal is then slowly pulled up, and the temperature is precisely controlled to promote the melt to crystallize at the lower end of the seed crystal. This is the starting point for single crystal growth. It is necessary to ensure that the crystallization is based on the epitaxial growth of the seed crystal lattice structure. After the seeding is completed, the shouldering is gradually reduced and the temperature is adjusted to increase the crystal diameter steadily from the narrow neck to the target diameter. This process requires extremely high control precision to ensure a uniform increase in diameter, maintain the single crystal structure of the crystal, and prevent defects or transformation into polycrystalline.

[0003] Key indicators of the seeding and shouldering process include power, liquid temperature accuracy, and the pass rate of the liquid-mouth distance. Currently, the pass rate of the liquid-mouth distance mainly relies on manual placement according to standards to ensure compliance with standards. However, the pass rate of automatic crucible placement is relatively low, making it difficult to meet the current survival rate requirements. The current system logic sets the automatic crucible placement process as follows: After the silicon material in the furnace is fully melted, the guide tube drops to the lower limit, and the system immediately triggers automatic crucible lifting. The distance between the liquid surface and the lower edge of the guide tube is determined by calculating the area of ​​the guide tube's reflected crescent. The crucible is then gradually raised until the settable liquid-mouth distance is reached, completing the automatic crucible placement operation. However, the existing logic does not fully consider the impact of liquid temperature differences within the furnace on the actual change in the liquid-mouth distance. As a result, after the subsequent temperature stabilization is completed, the actual liquid-mouth distance deviates, the pass rate of the liquid-mouth distance decreases, and thus affects the seeding survival rate. Currently, the concentration deviation of the liquid-mouth distance placement is large, with a trial range deviation of ±1 and a placement deviation of 0.5 by on-site personnel. This not only leads to high requirements for personnel attention and workload during the operation, but also there are abnormal risk points due to manual operation by personnel. For example, when manually lifting the crucible, the guide tube may be eaten, causing silicon spraying and explosion of the furnace, resulting in serious casualties. Summary of the Invention

[0004] The object of the present invention is to provide an automatic crucible placement system optimization method based on liquid temperature difference compensation to solve the existing problems.

[0005] The technical solution of the present invention to solve the above technical problems is as follows:

[0006] A method for optimizing an automatic crucible placement system based on liquid temperature difference compensation comprises the following steps:

[0007] During the single crystal silicon rod pulling process, when the silicon material in the furnace is fully melted and the guide tube drops to the lower limit, the system triggers the automatic crucible lifting;

[0008] The distance between the liquid surface and the lower edge of the guide tube is obtained by calculating the area of ​​the reflected crescent of the guide tube, and the crucible is gradually raised; the actual value of the seeding liquid temperature is obtained, and it is compared with the standard value of the seeding liquid temperature to obtain the liquid temperature deviation value; according to the liquid temperature deviation value, the precise measurement value of the liquid port distance is compensated and adjusted according to the preset compensation rule, and the compensation rule is: when the liquid temperature deviation is -10°C, the precise measurement value is compensated by 0.8; when the liquid temperature deviation is -5°C, the precise measurement value is compensated by 0.4; when the liquid temperature deviation is 5°C, the precise measurement value is compensated by -0.4; when the liquid temperature deviation is 10°C, the precise measurement value is compensated by -0.8, and the compensation value can be set;

[0009] Continue to lift the crucible to the set liquid port distance according to the precise measurement value after compensation adjustment, and complete the automatic crucible placement.

[0010] Further solution: The standard value of the seeding liquid temperature is 1450°C.

[0011] Further solution: Through the optimization method, the liquid port distance placement concentration is increased to about ±0.5.

[0012] Further solution: The preset compensation rule is stored in the control module of the system, and the system automatically calls the corresponding compensation value according to the liquid temperature deviation value to adjust the precise measurement value.

[0013] Further solution: the precise measurement value after compensation adjustment is used to control the action of the crucible lifting device to achieve accurate automatic crucible placement operation.

[0014] The present invention has the following beneficial effects:

[0015] Improve the automated process steps: Through the optimization method of the present invention, the automatic crystal pulling steps of the entire process from automatic feeding to automatic finishing are connected, thereby improving the degree of production automation, reducing manual intervention links, and improving production efficiency.

[0016] Reduce labor costs: significantly reduce the attention and workload of personnel at the crucible placement station, provide strong support for the company's subsequent streamlining of personnel and cost reduction, help the company optimize human resource allocation and improve overall economic benefits.

[0017] Improve safety: effectively reduce abnormal risk points caused by manual operation, such as avoiding serious accidents such as silicon spraying and furnace explosion caused by manual crucible lifting and eating the guide tube, ensuring the safety and stability of the production process, protecting the lives of personnel and the property of the enterprise.

[0018] Improve product quality: Increase the concentration of liquid nozzle distance placement and reduce the problem of lead-in survival rate caused by liquid nozzle distance deviation, which will help improve the product quality of single crystal silicon rods, make the produced single crystal silicon rods more advantageous in terms of crystal structure integrity and performance stability, and meet the market demand for high-quality single crystal silicon products. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is the current manual crucible placement process;

[0020] Figure 2 This is a schematic diagram of the automatic crucible placement position.

[0021] Figure 3 This is a schematic diagram of the automatic crucible placement process flow chart for this application. DETAILED DESCRIPTION

[0022] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0023] The current manual crucible placement process standard is as shown in Figure a:

[0024] Discharge port distance timing:

[0025] ① After the charging furnace table and the guide tube are lowered to zero position, when the material in the furnace is lumped into the size of a fist, the crucible is added to the welding crucible and the liquid outlet distance is roughly increased;

[0026] ② When the wire is broken and the furnace is not charged, the shoulder or the tail of the single crystal rises to the upper edge of the water cooling screen, the liquid outlet distance is placed;

[0027] Place the liquid port distance (310 special shape) according to the liquid surface temperature;

[0028] ①The liquid surface temperature is 1450 (1448-1453), and the liquid port distance is placed at 36;

[0029] ② The liquid surface temperature is below 1450 (1443-1447), and the liquid port distance is placed at 36.5;

[0030] ③The liquid surface temperature is around 1455 (1453-1457), and the liquid port distance is placed at 35.6;

[0031] ④The liquid surface temperature is around 1460 (1458-1463), and the liquid port distance is placed at 35.2;

[0032] ⑤ The liquid surface temperature is greater than 1464 and the liquid outlet is placed 34.7 away. It needs to be confirmed again before the seed crystal is welded;

[0033] Place the liquid outlet distance according to the liquid surface temperature (335 special-shaped / 335 flat / 360);

[0034] ①The liquid surface temperature is 1450 (1448-1453), and the liquid port distance is placed at 34.5-35;

[0035] ② The liquid surface temperature is below 1450 (1443-1447), and the liquid port distance is placed at 35.3;

[0036] ③The liquid surface temperature is around 1455 (1453-1457), and the liquid port distance is placed at 34.3;

[0037] ④The liquid surface temperature is around 1460 (1458-1463), and the liquid port distance is placed at 34;

[0038] ⑤ The liquid surface temperature is greater than 1464 and the liquid outlet is placed 33.5 away. It needs to be confirmed again before the seed crystal is welded;

[0039] Place the liquid port distance (tower shoulder) according to the liquid surface temperature;

[0040] ①The liquid surface temperature is 1450 (1448-1453), and the liquid port distance is placed at 31.5-32;

[0041] ② The liquid surface temperature is below 1450 (1443-1447), and the liquid port distance is placed at 32.3;

[0042] ③The liquid surface temperature is around 1455 (1453-1457), and the liquid port distance is placed at 31.3;

[0043] ④ The liquid surface temperature is around 1460 (1458-1463), and the liquid port distance is placed at 31;

[0044] ⑤ The liquid surface temperature is greater than 1464 and the liquid outlet is placed 30.5 away. It needs to be confirmed again before the seed crystal is welded;

[0045] The automatic crucible placement position of the present invention is as shown in Figure b:

[0046] Step 1: After the silicon material in the furnace is fully melted, the guide tube is lowered to the lower limit;

[0047] Step 2: The system triggers and starts the liquid port distance calibration;

[0048] Step 3: Calculate the distance between the liquid surface and the lower edge of the guide tube based on the area of ​​the reflected crescent of the guide tube, and gradually raise the crucible;

[0049] Step 4: After successful calibration, the final liquid port distance is placed by performing precise measurement compensation based on the settable liquid temperature deviation;

[0050] Automatic crucible lifting trigger: In a single crystal silicon rod pulling workshop, the pulling equipment is started. When the silicon material in the furnace is fully melted and the guide tube is accurately lowered to the lower limit, the system quickly triggers the automatic crucible lifting operation according to the set program. Initial crucible lifting operation: The system uses image recognition technology to accurately calculate the area of ​​the crescent reflection of the guide tube, and then calculates the distance between the liquid surface and the lower edge of the guide tube. Based on this data, the crucible lifting device is controlled to start gradually lifting the crucible. Liquid temperature data acquisition and comparison: Through a high-precision temperature sensor, the actual value of the seeding liquid temperature is obtained in real time. At this time, the measured liquid temperature is 1440℃. It is compared with the standard value of the seeding liquid temperature of 1450℃, and the calculated liquid temperature deviation value is -10℃.

[0051] Compensation Adjustment for Precision Measurement: Based on preset compensation rules, the system's control module identifies a liquid temperature deviation of -10°C and automatically adjusts the precision measurement of the liquid port distance by 0.8. For example, if the original precision measurement value for the liquid port distance was 35, after compensation adjustment, the precision measurement value becomes 35.8.

[0052] Automatic crucible placement completed: The crucible raising device continued to raise the crucible according to the compensated, precisely measured value of 35.8, until the set liquid-inlet distance was reached, successfully completing the automatic crucible placement. Subsequent testing showed that the concentration deviation of the liquid-inlet distance at this crucible placement position was within ±0.5, indicating a smooth lead-out process. The resulting single crystal silicon ingots were of high quality, free of obvious defects, and significantly improved lead-out survival rate.

[0053]

[0054]

[0055] Summary: One month after the new system was implemented, 864 data points were collected. The concentration ratio increased by 5%, and the overall survival rate was 95%, a 7% increase from 87% before the implementation.

[0056] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for optimizing an automatic crucible placement system based on liquid temperature difference compensation, characterized in that: The following steps are involved: During the single crystal silicon rod pulling process, when the silicon material in the furnace is fully melted and the guide tube drops to the lower limit, the system triggers the automatic crucible lifting; The distance between the liquid surface and the lower edge of the guide tube is calculated based on the area of ​​the reflected crescent of the guide tube, and the crucible is gradually raised; the actual value of the seeding liquid temperature is obtained, and it is compared with the standard value of the seeding liquid temperature to obtain the liquid temperature deviation value; According to the liquid temperature deviation value, the liquid port distance precision measurement value is compensated and adjusted according to the preset compensation rules; Continue to lift the crucible to the set liquid port distance according to the precise measurement value after compensation adjustment, and complete the automatic crucible placement.

2. The automatic crucible placement system optimization method based on liquid temperature difference compensation according to claim 1 is characterized in that: The compensation rule is: when the liquid temperature deviation is -10°C, the precise measurement value is compensated by 0.8; when the liquid temperature deviation is -5°C, the precise measurement value is compensated by 0.4; when the liquid temperature deviation is 5°C, the precise measurement value is compensated by -0.4; when the liquid temperature deviation is 10°C, the precise measurement value is compensated by -0.8, and the compensation value can be set.

3. The automatic crucible placement system optimization method based on liquid temperature difference compensation according to claim 1 is characterized in that: The standard value of the seeding liquid temperature is 1450°C.

4. The automatic crucible placement system optimization method based on liquid temperature difference compensation according to claim 1 is characterized in that: By means of the optimization method, the liquid port distance placement concentration is increased to about ±0.

5.

5. The automatic crucible placement system optimization method based on liquid temperature difference compensation according to claim 1 is characterized in that: The preset compensation rules are stored in the control module of the system, and the system automatically calls the corresponding compensation value according to the liquid temperature deviation value to adjust the precise measurement value.

6. The automatic crucible placement system optimization method based on liquid temperature difference compensation according to claim 1 is characterized in that: The precise measurement value after compensation adjustment is used to control the action of the crucible lifting device to achieve accurate automatic crucible placement operation.

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