Equal-diameter power control method matched with different thermal fields

Abstract

The invention belongs to the technical field of single crystal production, and relates to an equal-diameter power control method matched with different thermal fields, which comprises the following steps: when the temperature is stabilized, controlling the liquid level temperature T1 to be maintained for a first time, and then inputting stable temperature compensation power P1 into a coil base; recording a second time required for raising the liquid level temperature from T1 to T2; continuously observing the constant-diameter pulling speed curve, and comparing the constant-diameter pulling speed curve with a preset curve; the pulling speed curve trend is pre-judged, the coil base is notified to input equal-diameter compensation power P2 in advance, and the advance time is the second time; the pulling speed curve is matched with the growth curve of the single crystal. The method has the beneficial effects that the reaction time of the thermal field system is judged according to the temperature reaction time in the temperature stabilizing process, and the power compensation process is matched in advance in the equal-diameter process, so that the problems caused by too large or too small compensation power adjustment and too late or too early compensation in the equal-diameter growth process can be effectively controlled; the temperature fluctuation caused by the thermal field difference of the coil base is effectively solved, the bract breaking rate is reduced, and meanwhile the whole rod rate is increased.

Description

Technical Field

[0001] The invention belongs to the technical field of single crystal production and relates to an equal-diameter power control method for matching different thermal fields. Background Art

[0002] With the development of the photovoltaic industry, large-size thermal field pulling of large-size single crystals has gradually become one of the means to reduce costs and increase efficiency. As the size of the thermal field continues to increase, the feed amount has also increased from hundreds of kilograms to thousands of kilograms. While the large feed amount has increased production, it has also brought many problems. One of them is that the "thermal inertia" of the solution has increased, which leads to different insulation conditions and different aging degrees of thermal fields. Under the same power compensation process, different crystal pulling curves will appear, and the growth control effect will deviate greatly, resulting in easy overshoot of power control and increased broken buds. Therefore, an equal-diameter power control method matching different thermal fields is needed to solve the above technical problems. Summary of the invention

[0003] In order to solve the above-mentioned technical problems, the present invention provides an equal-diameter power control method that matches different thermal fields. It can individually match the growth control power compensation process according to the temperature response time of different thermal fields, effectively solve the temperature fluctuations caused by the differences in the thermal fields of the furnaces, reduce the broken bud rate, and increase the whole stick rate.

[0004] The technical solution adopted by the present invention is: a method for controlling equal-diameter power for matching different thermal fields, characterized in that it comprises the following steps:

[0005] When stabilizing the temperature, after controlling the liquid surface temperature T1 to maintain the first time, the furnace inputs the stabilizing temperature compensation power P1;

[0006] Record the second time required for the liquid surface temperature to rise from T1 to T2;

[0007] Continue to observe the pulling speed curve after equalizing the diameter and compare it with the preset curve;

[0008] Predict the trend of the pulling speed curve and notify the furnace to input the equal diameter compensation power P2 in advance, and the advance time is the second time;

[0009] Until the pulling rate curve matches the growth curve of the single crystal.

[0010] Furthermore, the difference between the liquid surface temperature T2 and the liquid surface temperature T1 is 0-5°C.

[0011] Furthermore, the liquid surface temperature T1 is 1448-1452°C.

[0012] Furthermore, the first time is 25 to 35 minutes.

[0013] Furthermore, the second time is 20 to 40 minutes.

[0014] Furthermore, the temperature stabilization compensation power P1 is 5-15 kW higher than the temperature stabilization power.

[0015] Furthermore, the temperature stabilization compensation power P1 is 5-30 kW.

[0016] Furthermore, the temperature stabilization compensation power P1 is 10-20 kW.

[0017] Furthermore, the equal-diameter compensation power P2 is 0.5-1 kW.

[0018] Furthermore, if the trend of the predicted pulling speed curve satisfies the preset curve, the growth continues.

[0019] The present invention relates to a method for controlling equal-diameter power for matching different thermal fields. In the method, the reaction time of the thermal field system is judged by the temperature reaction time of the thermal field in a temperature stabilization process, and the power compensation process is matched in advance during the equal-diameter process, that is, without affecting the normal growth of single crystals, appropriate temperature stabilization compensation power and advance time are given, and the equal-diameter compensation process is used as a reference. The method can effectively control the problems caused by excessive or insufficient adjustment of the compensation power, too late or too early compensation during the equal-diameter growth process, effectively solve the temperature fluctuation caused by the difference in the thermal field of the furnace, reduce the broken bud rate, and improve the whole rod rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a flow chart of an embodiment provided by the present invention. DETAILED DESCRIPTION

[0021] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0022] The present invention provides a method for controlling equal-diameter power for matching different thermal fields, which is characterized by comprising the following steps:

[0023] When stabilizing the temperature, after controlling the liquid surface temperature T1 to maintain the first time, the furnace inputs the stabilizing temperature compensation power P1;

[0024] Record the second time required for the liquid surface temperature to rise from T1 to T2;

[0025] Continue to observe the pulling speed curve after equalizing the diameter and compare it with the preset curve;

[0026] Predict the trend of the pulling speed curve and notify the furnace to input the equal diameter compensation power P2 in advance. The advance time is the second time;

[0027] Until the predicted pulling speed curve matches the growth curve of the single crystal.

[0028] In addition to the specific process parameter settings, the power compensation in the equal diameter process will provide additional power compensation through the growth control algorithm model according to the deviation between the actual pulling speed and the set pulling speed during the crystal growth process, that is, the equal diameter compensation power P2. This power compensation value generally has a pulling speed deviation amplitude, which is determined by the deviation duration. Theoretically, when two identical devices have the same set pulling speed and actual pulling speed, and the growth control algorithm model is turned on at the same growth position at the same time, the compensation power is consistent. However, in actual situations, due to the differences between thermal fields, even when the compensation power is consistent, the actual single crystal growth state is different. One of the reasons is the different temperature response time. Therefore, the technical solution judges the reaction time of the thermal field system through the temperature reaction time of the thermal field in the temperature stabilization process, and matches the equal-diameter compensation process in advance during the equal-diameter process, that is, without affecting the normal growth of the single crystal, a suitable temperature stabilization compensation power and advance time are given, and the equal-diameter compensation process is used as a reference. When the predicted pulling speed curve trend in the equal-diameter process cannot meet the preset curve, the equal-diameter compensation power is increased, and the advance time is consistent with the temperature stabilization compensation time. The problem caused by excessive or insufficient adjustment of the compensation power during the equal-diameter growth process can be effectively controlled, and the temperature fluctuations caused by the difference in the thermal field of the furnace are effectively solved, the broken bud rate is reduced, and the whole rod rate is improved.

[0029] Preferably, the difference between the liquid surface temperature T2 and the liquid surface temperature T1 is 0-5°C.

[0030] Preferably, the liquid surface temperature T1 is 1448-1452°C.

[0031] Preferably, the first time is 25 to 35 minutes.

[0032] Preferably, the second time is 20 to 40 minutes. The length of the second time matches the size of the thermal field. If the thermal field size is small, the thermal field temperature will react quickly and the second time will be short. According to the different thermal fields, a growth rate that matches the thermal field is selected to achieve a stable crystal growth curve.

[0033] Preferably, the temperature stabilization compensation power P1 is 5-15 kW higher than the temperature stabilization power.

[0034] Preferably, the temperature stabilization compensation power P1 is 5-30 kW.

[0035] Preferably, the temperature stabilization compensation power P1 is 10-20 kW.

[0036] Preferably, the equal-diameter compensation power P2 is 0.5-1 kW.

[0037] Preferably, if the predicted trend of the pulling speed curve satisfies the preset curve, the growth continues.

[0038] Embodiment 1:

[0039] With full crucible material, at a fixed liquid mouth distance, control the liquid surface temperature T1 to reach 1450℃ and stabilize it for 30 minutes. Match the appropriate temperature stabilization compensation power P1 according to the temperature stabilization power at this time, record the second time required for the liquid surface temperature to rise from T1 to T2, continue to observe the pulling speed curve after equal diameter, and compare it with the preset curve. If the predicted pulling speed curve trend cannot meet the preset curve, notify the furnace to input the equal diameter compensation power P2 in advance for the second time, until the predicted pulling speed curve trend curve matches the growth curve of the single crystal.

[0040] The liquid surface temperature T1 is 1450℃, the liquid surface temperature T2 is 1455℃, the first time, that is, the temperature stabilization compensation time, is 30min. The size of the thermal field is 36 inches, and the second time, that is, the advance time, is 40min.

[0041] The temperature stabilization compensation power P1 is 10kW, and the equal diameter compensation power P2 is 0.5kW.

[0042] The embodiments of the present invention are described in detail above, but the contents described are only preferred embodiments of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A method for controlling equal-diameter power to match different thermal fields, characterized in that: The steps include: When stabilizing the temperature, after controlling the liquid surface temperature T1 to maintain the first time, the furnace inputs the stabilizing temperature compensation power P1; Record the second time required for the liquid surface temperature to rise from T1 to T2; Continue to observe the pulling speed curve after equalizing the diameter and compare it with the preset curve; Predict the trend of the pulling speed curve and notify the furnace to input the equal diameter compensation power P2 in advance, and the advance time is the second time; Until the pulling rate curve matches the growth curve of the single crystal.

2. The equal-diameter power control method for matching different thermal fields according to claim 1 is characterized in that: The difference between the liquid surface temperature T2 and the liquid surface temperature T1 is 0-5°C.

3. The equal-diameter power control method for matching different thermal fields according to claim 2 is characterized in that: The liquid surface temperature T1 is 1448-1452°C.

4. The equal-diameter power control method for matching different thermal fields according to claim 1 is characterized in that: The first time is 25 to 35 minutes.

5. The equal-diameter power control method for matching different thermal fields according to claim 1, characterized in that: The second time is 20 to 40 minutes.

6. The equal-diameter power control method for matching different thermal fields according to claim 1, characterized in that: The temperature stabilization compensation power P1 is 5-15 kW higher than the temperature stabilization power.

7. The equal-diameter power control method for matching different thermal fields according to claim 6, characterized in that: The temperature stabilization compensation power P1 is 5-30 kW.

8. The equal-diameter power control method for matching different thermal fields according to claim 7 is characterized in that: The temperature stabilization compensation power P1 is 10-20 kW.

9. The equal-diameter power control method for matching different thermal fields according to any one of claims 1 to 8, characterized in that: The equal-diameter compensation power P2 is 0.5-1 kW.

10. The equal-diameter power control method for matching different thermal fields according to claim 9, characterized in that: If the trend of the predicted pulling speed curve meets the preset curve, the growth continues.

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