Granular silicon dehydrogenation process temperature detection device and method

Abstract

The invention provides a particle silicon dehydrogenation process temperature detection device, which comprises a temperature measurement assembly arranged above the molten silicon liquid level of a single crystal furnace and used for measuring the temperature of the molten silicon liquid level, and the temperature measurement assembly can move up and down along the height of a guide cylinder. The invention further provides a temperature detection method for the particle silicon dehydrogenation process, in the melting process, the temperature measurement assembly detects the temperature of the molten silicon liquid level in real time to obtain an actual temperature curve, the heating power is adjusted according to the set temperature curve, the actual temperature curve tends to the set temperature curve, and the temperature of the molten silicon liquid level is measured according to the actual temperature curve. The temperature of the silicon solution surface reaches the hydrogen removal temperature of the granular silicon. The device has the beneficial effects that a particle material melting process is optimized and improved through a temperature measurement result, so that the phenomenon of'hydrogen jump 'or'silicon jump' in a particle silicon production process is effectively reduced, the crystal formation abnormity of a single crystal is reduced, the survival rate of the single crystal is improved, and the device is simple in structure and convenient to operate.

Description

Technical Field

[0001] The present invention belongs to the technical field of single crystal silicon production, and in particular relates to a temperature detection device and method for a granular silicon dehydrogenation process. Background Art

[0002] The photovoltaic industry has entered a critical development period. Due to the low carbon value of granular silicon itself, it has been developed and applied unprecedentedly. In the field of CZ-grown single crystal silicon, granular silicon has been gradually used as a raw material to produce products with low carbon value. However, due to the high content of hydrogen in granular silicon, "hydrogen jump" or "silicon jump" phenomenon will occur during the production process due to the breakage of hydrogen-silicon bonds, which can easily cause abnormal single crystal formation and lead to low single crystal survival rate. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a temperature detection device and method for the granular silicon dehydrogenation process, which effectively solves the phenomenon of "hydrogen jump" or "silicon jump" in granular silicon during the production process by optimizing the material process through actual temperature measurement, and overcomes the inherent shortcomings of granular materials.

[0004] The technical solution adopted by the present invention is: a temperature detection device for a granular silicon dehydrogenation process, comprising a temperature measuring component, which is arranged above the molten silicon liquid level of a single crystal furnace and is used to measure the temperature of the molten silicon liquid level. The temperature measuring component can move up and down along the height of the guide tube.

[0005] Furthermore, it also includes a control component, which is arranged on the outer wall of the single crystal furnace and is connected to the measuring component.

[0006] Furthermore, the temperature measuring component is connected to the weight of the single crystal furnace, and the steel cable connected to the weight can drive the temperature measuring component to move up and down.

[0007] Furthermore, the weight is provided with a connecting piece, and the connecting piece is detachably connected to the temperature measuring component.

[0008] Furthermore, a protective layer is provided on the outside of the temperature measuring component.

[0009] The present invention also provides a method for detecting the temperature of the granular silicon dehydrogenation process, which adopts the detection device as described above, including: during the melting process, the temperature measuring component detects the temperature of the molten silicon liquid surface in real time to obtain an actual temperature curve, and adjusts the heating power according to the set temperature curve so that the actual temperature curve tends to the set temperature curve, and the temperature of the silicon solution surface reaches the dehydrogenation temperature of the granular silicon.

[0010] Furthermore, the distance between the measuring end of the temperature measuring component and the surface of the silicon solution is a fixed distance.

[0011] Furthermore, the fixed distance is 20-50 mm.

[0012] Furthermore, the dehydrogenation temperature of the granular silicon is not less than 1200°C.

[0013] Furthermore, the maximum operating temperature of the temperature measuring component is greater than 1600°C.

[0014] The advantages and positive effects of the present invention are: due to the adoption of the above-mentioned technical scheme, the phenomenon of "hydrogen jump" or "silicon jump" occurring in the production process of granular silicon is effectively reduced, the single crystal crystallization abnormality is reduced, the single crystal survival rate is improved, the structure is simple, and the operation is convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the overall structure of a temperature detection device for a granular silicon dehydrogenation process according to an embodiment of the present invention.

[0016] Figure 2 It is a schematic diagram of the connection of a temperature measuring component of a temperature detection device for a granular silicon dehydrogenation process according to an embodiment of the present invention.

[0017] Figure 3 It is a temperature curve diagram of a temperature detection device for a granular silicon dehydrogenation process according to an embodiment of the present invention.

[0018] Figure 4 It is a temperature curve diagram of a temperature detection device for a granular silicon dehydrogenation process according to an embodiment of the present invention.

[0019] In the figure:

[0020] 10. Temperature measuring component 11. Threaded connection 12. Protective layer

[0021] 13. Junction box 14. Protective cover 15. Temperature measuring end

[0022] 20, control assembly 30, weight 40, steel cable

[0023] 50. Connector 51. Opening 52. Connecting block

[0024] 53, threaded hole 60, seed crystal 70, guide tube

[0025] 80. Quartz crucible DETAILED DESCRIPTION

[0026] The embodiment of the present invention provides a device and method for detecting temperature of a granular silicon dehydrogenation process. The embodiment of the present invention is described below in conjunction with the accompanying drawings.

[0027] In the description of the embodiments of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "top", "bottom", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "set" and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0028] like Figure 1 As shown, a temperature detection device for a granular silicon dehydrogenation process according to an embodiment of the present invention comprises a temperature measuring component 10 and a control component 20. The temperature measuring component 10 is arranged above the molten silicon liquid level of a single crystal furnace, and is used to measure the temperature of the molten silicon liquid level during the melting process, and ensure that the temperature of the molten silicon liquid level is higher than the dehydrogenation temperature of the granular material, thereby achieving the dehydrogenation effect of the granular silicon. The temperature measuring component 10 is located inside the guide tube 70 and can move up and down along the height of the guide tube 70. During the melting process, the height of the quartz crucible 80 for placing granular silicon will change, and thus the height of the molten silicon liquid level will also change, and the temperature measuring component 10 will move up and down with the change of the height of the molten silicon liquid level. The temperature measuring component 10 is arranged at the center of the molten silicon liquid level. The molten silicon generally has a low center temperature and a high edge temperature. As long as the center temperature of the molten silicon is greater than the dehydrogenation temperature, all the molten silicon can complete the dehydrogenation process. The control component 20 is arranged on the outer wall of the single crystal furnace, and the control component 20 is connected to the temperature measuring component 10 by an electric couple wire, and is used to receive and process the temperature data measured by the temperature measuring component 10. In this embodiment, the temperature measuring component 10 is a straight-rod thermocouple with a maximum operating temperature greater than 1600° C., and the control component 20 is a temperature controller.

[0029] Specifically, the temperature measuring assembly 10 is connected to the weight 30 of the single crystal furnace, and the steel cable 40 connected to the weight 30 can drive the temperature measuring assembly 10 to move up and down. The weight 30 is detachably connected with a connector 50, and the connector 50 is detachably connected to the temperature measuring assembly 10, so that the temperature measuring assembly 10 and the connector 50 can be removed from the weight 30 before seeding.

[0030] In this embodiment, if Figure 2As shown, the connector 50 is cylindrical with a sealed bottom, wrapped around the outside of the weight 30, and the bottom of the weight 30 is connected to the seed crystal 60. The height of the connector 50 is greater than the total length of the weight 30 and the seed crystal 60. An opening 51 is provided on one side of the cylindrical connector 50. A connecting block 52 is fixed to the top of the weight 30, and the center of the connecting block 52 is fixedly connected to the steel cable 40. The top of the connector 50 is detachably connected to the connecting block 52 by bolts. A threaded hole 53 is provided at the bottom of the connector 50, and the temperature measuring component 10 is a straight rod thermocouple, which is provided with a threaded connecting portion 11. The temperature measuring component 10 passes through the threaded hole 53, and the threaded connecting portion 11 is adapted to the threaded hole 53.

[0031] Since the temperature inside the single crystal furnace is relatively high, a protective layer is provided on the outside of the temperature measuring component 10 to protect it. In the present embodiment, the temperature measuring component 10 is a straight-rod thermocouple, and a protective layer 12 can be bonded to the surface of the straight-rod portion at the bottom of the threaded connection portion 11 with a high-temperature resistant glue. The material of the protective layer 12 can be ceramic or other high-temperature resistant materials. The temperature measuring component 10 can be provided with a ceramic protective cover 14 on the outside of the straight-rod portion and the junction box 13 at the top of the threaded connection portion 11, and the ceramic heat-insulating cover is detachably connected to the bottom of the connector 50 by bolts.

[0032] A method for detecting the temperature of a granular silicon dehydrogenation process. During the melting process, the temperature measuring component 10 is placed in the center above the molten silicon liquid surface. The end of the temperature measuring component 10 is a temperature measuring end 15. The temperature measuring end 15 detects the temperature of the molten silicon liquid surface in real time. The control component 20 transmits the collected and measured actual temperature to the computer to obtain the actual temperature curve. When the actual temperature curve deviates from the set temperature curve, the heating power is adjusted so that the actual temperature curve tends to the set temperature curve. After the granular silicon is completely melted, the temperature of the silicon solution surface reaches the dehydrogenation temperature of the granular silicon, thereby ensuring that the granular silicon can be completely dehydrogenated. The dehydrogenation temperature of the granular silicon material is 1200°C. Therefore, after the granular silicon is completely melted, the minimum temperature of the silicon solution surface should reach 1200°C.

[0033] During the melting process, the height of the silicon solution surface is constantly changing, and the height of the temperature measuring component 10 also needs to be adjusted accordingly. In order to ensure the accuracy of the measurement, the distance between the measuring end of the temperature measuring component 10 and the surface of the molten silicon solution is a fixed distance. The fixed distance is usually set to 20-50mm. Since the temperature measuring component 10 and the seed crystal 60 are both connected to the weight 30, the relative position of the seed crystal 60 and the temperature measuring component 10 remains unchanged, and the height of the temperature measuring component 10 can be adjusted by adjusting the height of the seed crystal 60.

[0034] Embodiment 1: A temperature detection device for a granular silicon dehydrogenation process includes a temperature measuring component 10 and a control component 20. The temperature measuring component 10 is specifically a straight-rod thermocouple with a maximum operating temperature of 1700°C. The control component 20 is specifically a temperature controller. A connecting piece 50 is provided on the weight 30. The temperature measuring component 10 is threadedly connected to the bottom of the connecting piece 50. The steel cable 40 connected to the weight 30 can drive the temperature measuring component 10 to move up and down. The outside of the temperature measuring component 10 is provided with a high-temperature resistant ceramic protective layer 12 and a protective cover 14. The distance between the temperature measuring end 15 of the temperature measuring component 10 and the surface of the silicon solution is 20 mm. The control component 20 is installed on the outer wall of the single crystal furnace. The temperature measuring component 10 is connected to the control component 20.

[0035] like Figure 3 As shown, during the melting process, the temperature measuring end 15 of the temperature measuring component 10 detects the center temperature of the silicon solution surface in real time, and the control component 20 transmits the collected and measured actual temperature to the computer to obtain the actual temperature curve. A1 is the actual temperature curve, and B1 is the set temperature curve. In curve A1, the temperature of point a1 is 1006°C, point b1 is 1101°C, and point c1 is 1214°C. The actual temperature curve rises rapidly and gradually deviates from the set temperature curve B1. At this time, the heating power is reduced to reduce the increase in the actual temperature, so that the actual temperature curve A1 tends to the set temperature curve B1. During the melting process, the center temperature of the silicon solution surface is 1368°C, which is greater than the dehydrogenation temperature of granular silicon of 1200°C, and all granular silicon has completed dehydrogenation.

[0036] Embodiment 2: A temperature detection device for a granular silicon dehydrogenation process includes a temperature measuring component 10 and a control component 20. The temperature measuring component 10 is specifically a straight-rod thermocouple with a maximum operating temperature of 1800°C, and the control component 20 is specifically a temperature controller. A connecting piece 50 is provided on the weight 30, and the temperature measuring component 10 is threadedly connected to the bottom of the connecting piece 50. The steel cable 40 connected to the weight 30 can drive the temperature measuring component 10 to move up and down. The outside of the temperature measuring component 10 is provided with a high-temperature resistant ceramic protective layer 12 and a protective cover 14. The distance between the measuring end of the temperature measuring component 10 and the surface of the silicon solution is 25 mm. The control component 20 is installed on the outer wall of the single crystal furnace. The temperature measuring component 10 is connected to the control component 20.

[0037] like Figure 4As shown, during the melting process, the temperature measuring end 15 of the temperature measuring component 10 detects the center temperature of the silicon solution surface in real time, and the control component 20 transmits the collected and measured actual temperature to the computer to obtain the actual temperature curve. A2 is the actual temperature curve, and B2 is the set temperature curve. In curve A2, the temperature of point a2 is 523°C, point b2 is 562°C, and point c2 is 585°C. The actual temperature curve A2 rises slowly and gradually deviates from the set temperature curve B2. At this time, the heating power is increased to increase the actual temperature increase, so that the actual temperature curve A2 tends to the set temperature curve B2. During the melting process, the center temperature of the silicon solution surface is 1320°C, which is greater than the dehydrogenation temperature of granular silicon of 1200°C. All granular silicon completes dehydrogenation according to the set path.

[0038] The advantages and positive effects of the present invention are:

[0039] By adopting the above technical solution, the center temperature of the molten silicon liquid surface is detected in real time by setting the measuring component and the control component, and the actual temperature curve of the molten silicon liquid surface is adjusted to the set temperature curve by adjusting the heating power, thereby optimizing and improving the granular material process, ensuring that the center temperature of the molten silicon liquid surface is greater than the dehydrogenation temperature of the granular silicon during the melting process, so that all molten silicon can be dehydrogenated according to the process settings. It effectively reduces the phenomenon of "hydrogen jump" or "silicon jump" in the production process, reduces the abnormality of single crystal crystallization, and improves the survival rate of single crystals. It has a simple structure and is easy to operate.

[0040] 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 temperature detection device for a granular silicon dehydrogenation process, characterized in that: It comprises a temperature measuring component which is arranged above the molten silicon liquid level of the single crystal furnace and is used to measure the temperature of the molten silicon liquid level. The temperature measuring component can move up and down along the height of the guide tube.

2. A temperature detection device for granular silicon dehydrogenation process according to claim 1, characterized in that: It also includes a control component, which is arranged on the outer wall of the single crystal furnace and is connected to the measuring component.

3. A temperature detection device for granular silicon dehydrogenation process according to claim 1 or 2, characterized in that: The temperature measuring component is connected to the weight of the single crystal furnace, and the steel cable connected to the weight can drive the temperature measuring component to move up and down.

4. A temperature detection device for granular silicon dehydrogenation process according to claim 3, characterized in that: The weight is provided with a connecting piece, and the connecting piece is detachably connected to the temperature measuring component.

5. A temperature detection device for granular silicon dehydrogenation process according to any one of claims 1-2 and 4, characterized in that: A protective layer is arranged on the outside of the temperature measuring component.

6. A temperature detection method for granular silicon dehydrogenation process, characterized in that: The detection device as described in any one of claims 1 to 5 comprises: during the melting process, the temperature measuring component detects the temperature of the molten silicon liquid surface in real time to obtain an actual temperature curve, and adjusts the heating power according to the set temperature curve so that the actual temperature curve tends to the set temperature curve, and the temperature of the silicon solution surface reaches the dehydrogenation temperature of the granular silicon.

7. A temperature detection method for granular silicon dehydrogenation process according to claim 6, characterized in that: The distance between the measuring end of the temperature measuring component and the surface of the silicon solution is a fixed distance.

8. The method for detecting temperature of a granular silicon dehydrogenation process according to claim 7, characterized in that: The fixed distance is 20-50 mm.

9. A method for detecting temperature of a granular silicon dehydrogenation process according to any one of claims 6 to 8, characterized in that: The dehydrogenation temperature of the granular silicon is not less than 1200°C.

10. A temperature detection method for granular silicon dehydrogenation process according to claim 9, characterized in that: The maximum operating temperature of the temperature measuring component is greater than 1600°C.

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