High-precision liquid level moving position measuring assembly

Abstract

The utility model discloses a high-precision liquid level moving position measuring assembly, which comprises a crucible, a liquid level sensor, a liquid level sensor and a liquid level sensor, the guide cylinder is arranged above the silicon liquid, and a high-temperature-resistant component is arranged at the bottom of the guide cylinder; the crystal bar cooling device is arranged above the silicon liquid, the crystal bar cooling device is arranged in the guide cylinder, and a plurality of crystal pulling holes are formed in the bottom of the crystal bar cooling device; the camera is used for acquiring the high-temperature-resistant component and the image of the inverted image of the high-temperature-resistant component on the silicon liquid level; the controller is used for receiving and processing data transmitted by the camera; a protrusion is arranged on the high-temperature-resistant component, and a through hole is formed in the protrusion. The high-precision liquid level moving position measuring assembly is convenient to use, and can measure and control the moving positions of the bottom of a crystal bar cooling device and the liquid level of raw material silicon liquid in real time through camera measurement and controller control, so that the diameter of a crystal bar can be controlled.

Description

Technical Field

[0001] This utility model relates to the field of silicon core production technology, specifically to a high-precision liquid level movement position measurement component. Background Technology

[0002] Polycrystalline / monocrystalline silicon is a crucial raw material for industries such as semiconductors and photovoltaics. The production of polycrystalline / monocrystalline silicon involves a large amount of silicon cores. Currently, the most advanced silicon core fabrication method uses a multi-turn Czochralski crystal growth furnace to directly pull multiple silicon cores. The principle involves heating the raw material until it melts into a liquid state, then using seed crystals to guide the recrystallization of the liquid material into the desired silicon core. To ensure stable crystal growth and control the crystal rod diameter, it is essential to maintain appropriate speed and positional accuracy of the liquid surface movement during the fabrication process. This ensures that the distance between the bottom of the silicon core cooling device and the silicon liquid surface remains constant and suitable. Therefore, accurately measuring the liquid surface movement position is crucial for stable silicon core growth.

[0003] Currently, the industry commonly uses horizontal measurement for vision systems to measure liquid surface movement. This method cannot linearly represent changes in liquid surface position, has poor accuracy, and exhibits large fluctuations, failing to achieve precise control of the liquid surface position. Some methods use oblique measurements at specific angles, but these angles are affected by the installation angle of the measuring camera, and obtaining this specific angle value initially requires the production of a crystal ingot. Without physical calibration of the actual liquid surface position, changes in the actual liquid surface movement are judged manually based on experience, making it highly susceptible to subjective factors.

[0004] Based on the above, this utility model proposes a high-precision liquid surface movement position measuring component, which can effectively solve the above problems. Utility Model Content

[0005] The purpose of this invention is to provide a high-precision liquid level movement position measurement component. This high-precision liquid level movement position measurement component is easy to use, employing camera measurement and controller control to achieve real-time measurement and control of the movement position of the bottom of the crystal rod cooling device and the surface of the raw silicon liquid, thereby enabling control of the crystal rod's diameter.

[0006] This utility model is achieved through the following technical solution:

[0007] A high-precision liquid level movement position measurement component, comprising:

[0008] A crucible containing molten silicon;

[0009] A flow guide tube is positioned above the molten silicon, and a high-temperature resistant component is provided at the bottom of the flow guide tube;

[0010] The crystal bar cooling device is arranged above the silicon liquid and in the draft tube, and a plurality of crystal bar pulling holes are arranged in the bottom of the crystal bar cooling device.

[0011] A camera is arranged for acquiring images of the high-temperature-resistant part and the high-temperature-resistant part reflected on the surface of the silicon liquid.

[0012] A controller is arranged for receiving and processing data transmitted by the camera.

[0013] The high-temperature-resistant part is provided with a protrusion, and a through hole is arranged in the protrusion.

[0014] The high-precision liquid surface moving position measurement assembly is convenient to use and can realize real-time measurement and control of the moving position of the bottom of the crystal bar cooling device and the raw material silicon liquid surface through camera measurement and controller control, so that the diameter of the crystal bar can be controlled.

[0015] Preferably, the bottom of the crystal bar cooling device is provided with an electrostatic capacity detection device.

[0016] Preferably, the electrostatic capacity detection device comprises a silicon liquid contact piece and a signal amplifier which are electrically connected in sequence, the silicon liquid contact piece protrudes downward from the bottom of the electrostatic capacity detection device by a distance L1, and the signal amplifier is electrically connected with the controller.

[0017] Preferably, the signal amplifier comprises a resistor R1 and a slide rheostat R2, one end of the resistor R1 and one end of the slide rheostat R2 are electrically connected through a first lead wire, a second lead wire is connected to the first lead wire, the other end of the resistor R1 is connected with a third lead wire, and the other end of the slide rheostat R2 is connected with a fourth lead wire.

[0018] Preferably, the high-temperature-resistant part is provided with a mounting hole.

[0019] A measurement method of a high-precision liquid surface moving position measurement assembly comprises the following steps:

[0020] Step S1: preset a reference measurement value D0 in the controller, slowly raise the crucible when confirming the liquid surface position for the first time, and stop raising the crucible immediately when the controller detects the output voltage of the electrostatic capacity detection device.

[0021] Step S2: then lower the crucible by a distance D1, at this time, the physical distance between the bottom of the crystal bar cooling device and the liquid surface is D2, and the calculation formula is:

[0022] D2=(L1+D1)

[0023] Wherein, L1 is the protruding length of the electrostatic capacity detection device, and D1 is the distance by which the crucible is lowered after the electrostatic capacity detection device contacts the liquid surface.

[0024] Step S3: after the liquid level is stable, the camera takes an image of the high-temperature-resistant part and the inverted image of the high-temperature-resistant part in the liquid level;

[0025] Step S4: the pixel distance between the through hole of the high-temperature-resistant part in the image and the through hole of the high-temperature-resistant part in the inverted image is D3, and the actual physical distance D2 and the pixel distance D3 measured by the camera are the current actual liquid level distance and the industrial camera measurement distance relationship;

[0026] Step S5: the crucible slowly drops by 5mm, and the camera takes an image of the high-temperature-resistant part and the inverted image of the high-temperature-resistant part in the liquid level;

[0027] Step S6: the pixel distance between the through hole of the high-temperature-resistant part in the image and the through hole of the high-temperature-resistant part in the inverted image is D4, and the pixel measurement value D5 corresponding to each 0.01mm drop is calculated, and the calculation formula is:

[0028] D5=(D4-D3) / 500;

[0029] Step S7: input D5 into the controller, and calibrate D5 as the pixel change amount corresponding to each 0.01mm drop of the actual crucible in the controller;

[0030] Step S8: when the crystal bar is in a continuous growth process, the through hole of the high-temperature-resistant part and its inverted image will change with the actual liquid level position movement, the camera records the pixel distance between the through hole of the high-temperature-resistant part and the through hole of the high-temperature-resistant part in the inverted image in real time as D6, and the actual liquid level distance D7 is calculated through the formula D7=D2+(D6-D3) / D5*0.01, and the real-time information of the liquid level movement position is obtained;

[0031] Step S9: the liquid level distance D7 is fed back to the controller, the controller compares the real-time liquid level distance D7 with the reference measurement value D0, and then adjusts the liquid level position height according to the comparison result.

[0032] Compared with the prior art, the utility model has the advantages and beneficial effects that:

[0033] 1. The electrostatic capacity detection device is used to judge the actual physical distance between the liquid level and the bottom of the crystal bar cooling device, so as to avoid the error caused by manual naked eye observation.

[0034] 2. The through hole arranged on the high-temperature-resistant part is beneficial to the target feature extraction accuracy of visual measurement, and higher measurement accuracy effect is achieved. The problems of poor reflection of traditional graphite material, difficulty in feature extraction and easy oxidation are avoided.

[0035] 3. Through two calibrations, the relationship between the actual physical distance and the pixel measurement value, as well as the relationship between the pixel distance corresponding to a crucible lifting and lowering of 0.01 mm, are respectively calibrated, so that the change in the measured value is consistent with the change in the actual distance value, and the overall error is within 1%, which meets the requirements for silicon rod pulling.

[0036] 4. Compare the calculated actual distance between the through hole of the high-temperature resistant component and its reflection with the set target value, and then feed the comparison result back to the controller. The controller controls the crucible to lift and lower to adjust the liquid level position, so as to realize the real-time measurement and control of the movement position of the bottom of the crystal rod cooling device and the liquid surface of the raw silicon liquid, thereby controlling the diameter of the crystal rod. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the structure of this utility model;

[0038] Figure 2 for Figure 1 A magnified schematic diagram of the partial structure at point A in the middle;

[0039] Figure 3 This is a schematic diagram of the structure of the signal amplifier described in this utility model;

[0040] Figure 4 This is a schematic diagram of the high-temperature resistant component described in this utility model. Detailed Implementation

[0041] To enable those skilled in the art to better understand the technical solution of this utility model, the preferred embodiments of this utility model are described below in conjunction with specific examples. However, it should be understood that the accompanying drawings are for illustrative purposes only and should not be construed as limiting this patent. For better illustration of this embodiment, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable that some well-known structures and their descriptions may be omitted in the drawings for those skilled in the art. The positional relationships described in the drawings are for illustrative purposes only and should not be construed as limiting this patent.

[0042] Unless otherwise specified, the technical features of the controller and other components described in this utility model are obtained from conventional commercial channels or manufactured by conventional methods. Their specific structure, working principle, and possible control methods and spatial arrangement methods can adopt conventional choices in the field and should not be regarded as the innovation of this utility model. This is understandable to those skilled in the art, and this utility model patent will not be further elaborated in detail.

[0043] Example 1:

[0044] like Figures 1 to 4 As shown, a high-precision liquid level movement position measurement component includes:

[0045] a crucible 1, which is filled with silicon liquid 2;

[0046] a draft tube 3, which is arranged above the silicon liquid 2, and the bottom of the draft tube 3 is provided with a high-temperature-resistant part 6;

[0047] a crystal bar cooling device 4, which is arranged above the silicon liquid 2, and the crystal bar cooling device 4 is arranged in the draft tube 3, and the bottom of the crystal bar cooling device 4 is provided with a plurality of crystal pulling holes 41;

[0048] a camera 5, which is used to obtain the image of the high-temperature-resistant part 6 and the inverted image of the high-temperature-resistant part 6 on the surface of the silicon liquid;

[0049] a controller, which is used to receive and process the data transmitted by the camera 5;

[0050] The high-temperature-resistant part 6 is provided with a protrusion 61, and the protrusion 61 is provided with a through hole 62.

[0051] The crystal bar cooling device 4 is used to cool the crystal bar, and the crystal bar is placed in the crystal pulling hole 41. The crucible 1 is usually provided with a lifting device at the bottom, and the controller controls the lifting of the crucible 1, which belongs to the prior art and will not be described here.

[0052] Embodiment 2:

[0053] As shown in Figures 1 to 4 A high-precision liquid level moving position measurement assembly, comprising:

[0054] a crucible 1, which is filled with silicon liquid 2;

[0055] a draft tube 3, which is arranged above the silicon liquid 2, and the bottom of the draft tube 3 is provided with a high-temperature-resistant part 6;

[0056] a crystal bar cooling device 4, which is arranged above the silicon liquid 2, and the crystal bar cooling device 4 is arranged in the draft tube 3, and the bottom of the crystal bar cooling device 4 is provided with a plurality of crystal pulling holes 41;

[0057] a camera 5, which is used to obtain the image of the high-temperature-resistant part 6 and the inverted image of the high-temperature-resistant part 6 on the surface of the silicon liquid;

[0058] a controller, which is used to receive and process the data transmitted by the camera 5;

[0059] The high-temperature-resistant part 6 is provided with a protrusion 61, and the protrusion 61 is provided with a through hole 62.

[0060] The bottom of the crystal bar cooling device 4 is provided with an electrostatic capacity detection device.

[0061] Further, in another embodiment, the electrostatic capacity detection device comprises a silicon liquid contact 7 and a signal amplifier connected in sequence, the silicon liquid contact 7 protrudes downward from the bottom of the electrostatic capacity detection device by a distance L1, and the signal amplifier is electrically connected with the controller.

[0062] When the device is in contact with the silicon liquid surface, the electrostatic capacity detection device is open-circuit conduction, forming a closed loop,

[0063] Further, in another embodiment, the signal amplifier comprises a resistor R1 and a slide rheostat R2, one end of the resistor R1 and one end of the slide rheostat R2 are electrically connected through a first lead wire 81, the first lead wire 81 is connected with a second lead wire 82, the other end of the resistor R1 is connected with a third lead wire 83, and the other end of the slide rheostat R2 is connected with a fourth lead wire 84.

[0064] The detection principle is that a voltage is applied between the silicon liquid contacts 7, since the silicon liquid contacts 7 are not in contact with the silicon liquid surface, the detection device is in an open-circuit state, the current direction is 24V→20K→A10P→5.26K→A10N→24N, and no voltage is output at the PH end of the detection device. When the silicon liquid contacts 7 are in contact with the silicon liquid surface, the detection device PH end loop is closed and voltage is output, the current direction is 24V→20K→A10P→PH, the voltage is amplified by the signal amplifier and then output to the PLC analog input port, and the PLC judges whether the silicon liquid contacts 7 are in contact with the liquid surface according to the input voltage.

[0065] Further, in another embodiment, the high-temperature-resistant part 6 is provided with a mounting hole 63.

[0066] The mounting hole 63 facilitates the mounting of the high-temperature-resistant part 6 on the flow guide hole.

[0067] According to another aspect of the present application, a measurement method of a high-precision liquid surface moving position measurement assembly is provided, comprising the following steps:

[0068] Step S1: a reference measurement value D0 is preset in the controller, the crucible 1 is slowly raised when the liquid surface position is confirmed for the first time, and the rising of the crucible 1 is stopped immediately when the controller detects the output voltage of the electrostatic capacity detection device, that is, when the electrostatic capacity detection device is just in contact with the liquid surface;

[0069] Step S2: the crucible 1 is further lowered by a distance D1 (to prevent the high-temperature silicon liquid 2 from contacting the electrostatic capacity detection device for a long time and reduce the service life of the device), at this time, the physical distance between the bottom of the crystal bar cooling device 4 and the liquid surface is D2, and the calculation formula is:

[0070] D2=(L1+D1)

[0071] Wherein, L1 is the protruding length of the electrostatic capacity detection device, D1 is the distance of the crucible 1 descending after the electrostatic capacity detection device contacts the liquid surface;

[0072] Step S3: After the liquid surface is stable, the camera 5 takes the image of the high-temperature-resistant part 6 and the reflection of the high-temperature-resistant part 6 in the liquid surface at this time;

[0073] Step S4: The pixel distance between the through hole 62 of the high-temperature-resistant part 6 in the image and the through hole 62 of the high-temperature-resistant part 6 in the reflection is D3, and the calibration of the actual physical distance D2 and the pixel distance D3 measured by the camera 5 is the current actual liquid surface distance and the distance measured by the industrial camera 5;

[0074] Step S5: The crucible 1 slowly descends by 5mm, and the camera 5 takes the image of the high-temperature-resistant part 6 and the reflection of the high-temperature-resistant part 6 in the liquid surface at this time;

[0075] Step S6: The pixel distance between the through hole 62 of the high-temperature-resistant part 6 in the image and the through hole 62 of the high-temperature-resistant part 6 in the reflection is D4, and the pixel measurement value D5 corresponding to each 0.01mm descent is calculated, and the calculation formula is:

[0076] D5=(D4-D3) / 500;

[0077] Step S7: D5 is input into the controller, and D5 is calibrated in the controller as the pixel change amount corresponding to each 0.01mm descent of the actual crucible 1;

[0078] Step S8: When the crystal bar is in the continuous growth process, at this time, the through hole 62 of the high-temperature-resistant part 6 and the reflection thereof will change with the actual liquid surface position movement, the camera 5 records the pixel distance between the through hole 62 of the high-temperature-resistant part 6 and the through hole 62 of the high-temperature-resistant part 6 in the reflection in real time as D6, and the actual liquid surface distance D7 is calculated through the formula D7=D2+(D6-D3) / D5*0.01, and the real-time information of the liquid surface movement position is obtained;

[0079] Step S9: The liquid surface distance D7 is fed back to the controller, the controller compares the real-time liquid surface distance D7 with the reference measurement value D0, and then adjusts the height of the liquid surface position according to the comparison result, so that the crystal growth speed matches the liquid surface movement position speed, and the liquid surface movement position is compared and adjusted throughout the crystal pulling process, so as to ensure that the size fluctuation of the crystal bar diameter is qualified.

[0080] According to the description and drawings of the utility model, those skilled in the art can easily manufacture or use the high-precision liquid surface movement position measuring assembly of the utility model, and the positive effects recorded in the utility model can be achieved.

[0081] Unless otherwise stated and limited, the terms "length", "width", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like, as used herein, refer to the orientation or position of the device or element shown in the drawings, and are used only to facilitate the description of the present application and simplify the description, and do not indicate or imply that the device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore the terms describing the orientation or position of the device or element herein are only used for exemplary description, and cannot be understood as a limitation on the patent. For those skilled in the art, the specific meanings of the above terms can be understood in conjunction with the drawings and according to the specific circumstances.

[0082] Unless otherwise stated and limited, the terms "set", "connected" and "connected" in the present application should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium; it can be the communication between the two elements inside. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0083] The above is only a preferred embodiment of the present application, and does not limit the present application in any form. Any simple modification or equivalent change of the above embodiment according to the technical essence of the present application falls within the scope of protection of the present application.

Claims

1. A high-precision liquid level movement position measuring assembly, characterized by The utility model relates to a kind of silicon crystal pulling device, including: Crucible, which is filled with silicon liquid; Flow guide tube, which is arranged above the silicon liquid, and the bottom of the flow guide tube is provided with a high-temperature-resistant component; Crystal bar cooling device, which is arranged above the silicon liquid and is arranged in the flow guide tube, and the bottom of the crystal bar cooling device is provided with a plurality of crystal pulling holes; Camera, which is used to obtain the image of the high-temperature-resistant component and the reflection of the high-temperature-resistant component on the surface of the silicon liquid; Controller, which is used to receive and process the data transmitted by the camera; The high-temperature-resistant component is provided with a protrusion, and a through hole is formed in the protrusion.

2. The high precision liquid level movement position measuring assembly according to claim 1, characterized in that: The bottom of the crystal bar cooling device is provided with an electrostatic capacity detection device.

3. The high precision liquid level movement position measuring assembly according to claim 2, characterized in that: The electrostatic capacity detection device includes a silicon liquid contact and a signal amplifier connected in sequence, the silicon liquid contact protrudes downward from the bottom of the electrostatic capacity detection device by a distance L1, and the signal amplifier is electrically connected with the controller.

4. The high precision liquid level movement position measuring assembly according to claim 3, characterized in that: The signal amplifier includes a resistor R1 and a slide rheostat R2, one end of the resistor R1 and one end of the slide rheostat R2 are electrically connected by a first wire, a second wire is connected to the first wire, the other end of the resistor R1 is connected to a third wire, and the other end of the slide rheostat R2 is connected to a fourth wire.

5. The high precision liquid level movement position measuring assembly of claim 1, wherein: The high-temperature-resistant component is provided with a mounting hole.

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