System and method for measuring rotation precision of lifting head

Abstract

A lifting head rotation precision measuring system disclosed by the present invention comprises a power assembly, a rotation assembly, a measuring assembly and a judgment assembly, the power assembly is used for driving the rotation assembly to rotate, the measuring assembly comprises a detection device and a crystal transcoding disc, the crystal transcoding disc is fixedly installed on the rotation assembly, and the crystal transcoding disc rotates along with the rotation assembly. A plurality of code disc hollow parts are uniformly arranged on the periphery of the crystal transcoding disc, and the detection device is used for identifying the code disc hollow parts when the crystal transcoding disc rotates, outputting a first signal when the code disc hollow parts are identified, and outputting a second signal when the code disc hollow parts are not identified. The judgment assembly is used for calculating the rotation error of the rotation assembly according to the difference between the number of the received first signals and the second signals and the theoretical number, and the rotation precision of the rotation assembly is obtained. The code disc hollow part is arranged on the crystal transcoding code disc, the control precision of the upper driving crystal transcoding can be accurately measured according to the comparison between the identification result of the code disc hollow part and the theoretical condition, the cost is low, and the operation is convenient.

Description

Technical Field

[0001] This invention relates to a measuring device for semiconductor crystal growth furnaces, specifically to a system and method for measuring the rotational accuracy of a pull-up head. Background Technology

[0002] In the process of preparing and growing single-crystal silicon, it is necessary to drive the crystal rotation, and the rotation speed has a significant impact on the growth of silicon carbide crystals. If the rotation speed exceeds the expected control, it is very likely to have a negative impact on the growth of silicon carbide crystals. In the existing technology, it is impossible to detect the control precision of driving the crystal rotation. Summary of the Invention

[0003] Purpose of the invention: To address the above-mentioned shortcomings, this invention provides a measurement system and method capable of measuring the rotational accuracy of the crystal in the lifting head.

[0004] Technical Solution: To solve the above problems, the present invention employs a lifting head rotation accuracy measurement system, including a power component, a rotation component, a measurement component, and a judgment component. The power component drives the rotation component to rotate. The measurement component includes a detection device and a crystal encoder disk. The crystal encoder disk is fixedly installed on the rotation component. When the rotation component rotates, the crystal encoder disk rotates with the rotation component. A plurality of hollow encoder disk portions are evenly arranged on the outer circumference of the crystal encoder disk. The detection device is used to identify the hollow encoder disk portions when the crystal encoder disk rotates. When a hollow encoder disk portion is identified, a first signal is output; when no hollow encoder disk portion is identified, a second signal is output. The judgment component is used to receive the first and second signals and calculate the rotation error of the rotation component based on the difference between the number of the first and second signals received and the theoretical number, thereby obtaining the rotation accuracy of the rotation component.

[0005] Furthermore, the detection device includes a first photoelectric limit switch and a second photoelectric limit switch. When the first photoelectric limit switch detects the hollow part of the code disk, it outputs a first signal, and when the second photoelectric limit switch does not detect the hollow part of the code disk, it outputs a second signal.

[0006] Furthermore, when the number of hollow parts on the code disk is greater than 500, the measurement accuracy of the lifting head rotation accuracy measurement system is greater than one-thousandth.

[0007] Furthermore, the power assembly includes a servo motor and a multi-ribbed belt, with the servo motor driving the rotating assembly to rotate via the multi-ribbed belt.

[0008] Furthermore, it also includes an adjustment bracket, on which the first photoelectric limit switch and the second photoelectric limit switch are mounted, and the relative positions of the first photoelectric limit switch and the second photoelectric limit switch with the crystal encoder disk are adjusted by adjusting the bracket.

[0009] Furthermore, the space between two adjacent hollow portions of the code disk is a solid portion of the code disk. When the first photoelectric limit switch detects a hollow portion of the code disk, it outputs a first signal, and when the second photoelectric limit switch detects a solid portion of the code disk, it outputs a second signal.

[0010] The present invention also employs a measurement method for the above-mentioned lifting head rotation accuracy measurement system, comprising the following steps:

[0011] Step 1: Determine the rotational speed of the rotating component;

[0012] Step 2: The power component drives the rotating component to rotate, receiving the first and second signals output by the detection device;

[0013] Step 3: Select a measurement time period and obtain the actual value of the total number of first and second signals received within the measurement time period; calculate the theoretical value of the total number of first and second signals that should be received based on the rotational speed of the rotating component and the length of the measurement time period.

[0014] Step 4: Calculate the difference between the actual value and the theoretical value. The ratio of the difference to the theoretical value gives the rotational accuracy of the rotating component.

[0015] Furthermore, the space between two adjacent hollow portions of the code disk is a solid portion of the code disk. When the detection device detects a hollow portion of the code disk, it outputs a first signal, and when the detection device detects a solid portion of the code disk, it outputs a second signal.

[0016] Furthermore, when the number of hollow parts on the code disk is greater than 500, the measurement accuracy of the lifting head rotation accuracy measurement system is greater than one-thousandth.

[0017] Furthermore, the outer periphery of the crystal encoder disk is uniformly arranged with 502 hollow code disk sections and 502 solid code disk sections. The measurement time period is selected as the time it takes for the rotating component to rotate one revolution. The actual value C of the total number of first and second signals received within the measurement time period is obtained. The rotation accuracy calculation formula is: When the actual value C is in the range of 1003~1005, the rotation accuracy of the rotating component is less than one-thousandth.

[0018] Beneficial effects: Compared with the prior art, the present invention has the advantage of setting a hollow part on the code disk of the crystal transfer code disk. By comparing the identification results of the hollow part of the code disk with the theoretical situation, the control accuracy of the upper drive crystal transfer can be accurately measured. It is low in cost and easy to operate. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the lifting head rotation accuracy measurement system of the present invention.

[0020] Figure 2 This is an enlarged schematic diagram of the edge structure of the crystal transcode disk in this invention. Detailed Implementation

[0021] like Figure 1 As shown, a lifting head rotation accuracy measurement system in this embodiment includes a power component, a rotation component 3, a measurement component, and a judgment component. The power component is used to drive the rotation component 3 to rotate. The power component includes a servo motor 1 and a multi-ribbed belt 2. The servo motor 1 is fixed on the equipment. The rotation component 3 is connected to the servo motor 1 through a bearing device and the multi-ribbed belt, and has a rotation function. The multi-ribbed belt 2 is used for intermediate transmission between the rotation component 3 and the servo motor 1. The torque provided by the servo motor 1 is transmitted through the multi-ribbed belt 2 to realize the rotation of the rotation component 3.

[0022] The measuring assembly includes a detection device and a crystal encoder 6. The detection device includes a first photoelectric limit switch 4 and a second photoelectric limit switch 5, which are mounted on an adjusting bracket 7. The relative positions of the first and second photoelectric limit switches 4 and 5 with the crystal encoder 6 are adjusted by the adjusting bracket 7. The crystal encoder 6 is fixedly mounted on a rotating assembly 3. When the rotating assembly 3 rotates, the crystal encoder 6 rotates together with the rotating assembly 3.

[0023] like Figure 2 As shown, the outer periphery of the crystal encoder 6 is uniformly arranged with several hollow encoder portions 8 and several solid encoder portions 9, with a solid encoder portion 9 between two adjacent hollow encoder portions 8. In this embodiment, to achieve a measurement accuracy greater than one-thousandth, 502 hollow encoder portions 8 and 502 solid encoder portions 9 are provided. The first photoelectric limit switch 4 is used to detect the hollow encoder portions 8, and the second photoelectric limit switch 5 is used to detect the solid encoder portions 9. During the rotation of the rotating assembly 3, when a hollow encoder portion 8 passes the first photoelectric limit switch 4, the first photoelectric limit switch 4 will feed back a first signal; when a solid encoder portion 9 passes the second photoelectric limit switch 5, the second photoelectric limit switch 5 will feed back a second signal. In this embodiment, when the rotating assembly 3 rotates one revolution, the first photoelectric limit switch 4 and the second photoelectric limit switch 5 should theoretically feed back a total of 1004 signals. The determination component is used to receive the first signal and the second signal, and the rotation error of the rotating component is calculated based on the difference between the number of the first signal and the second signal received and the theoretical number, so as to obtain the rotation accuracy of the rotating component.

[0024] The measurement method using the above-mentioned lifting head rotation accuracy measurement system includes the following steps:

[0025] Step 1: Determine the rotational speed A (r / min) and rotation time B (min) of the rotating component;

[0026] Step 2: The power component drives the rotating component to rotate, receives the first signal and the second signal output by the first photoelectric limit switch 4 and the second photoelectric limit switch 5; and records the signal distribution fed back by the first photoelectric limit switch 4 and the second photoelectric limit switch 5.

[0027] Step 3: During the rotation time, select a measurement time period and obtain the actual value of the total number of first and second signals received during the measurement time period; based on the rotation speed of the rotating component and the length of the measurement time period, calculate the theoretical value of the total number of first and second signals that should be received.

[0028] In this embodiment, the length of the measurement time period is selected as the time it takes for the rotating component to complete one rotation. Within this rotation time, a time period is randomly selected. (s), read this time period The total number of signals fed back by the first photoelectric limit switch 4 and the second photoelectric limit switch 5 within (s) is C (numbers). Theoretically, within the time period... The total number of signals fed back by the first photoelectric limit switch 4 and the second photoelectric limit switch 5 within (s) is 1004.

[0029] Step 4: Calculate the difference between the actual value and the theoretical value. The ratio of the difference to the theoretical value gives the rotational accuracy of the rotating component. In this embodiment, the crystal rotation error can be calculated as follows: When the actual value C is in the range of 1003~1005, the rotation accuracy of the rotating component is less than one-thousandth.

Claims

1. A pull head rotation accuracy measurement system, characterized by, The application relates to a pulling head rotation precision measurement system, which comprises a power assembly, a rotating assembly (3), a measuring assembly and a judging assembly, the power assembly is used for driving the rotating assembly (3) to rotate, the measuring assembly comprises a detection device and a crystal rotation code disc (6), the crystal rotation code disc (6) is fixedly installed on the rotating assembly (3), and the crystal rotation code disc (6) rotates with the rotating assembly (3) when the rotating assembly (3) rotates, a plurality of code disc hollow parts (8) are uniformly arranged on the outer periphery of the crystal rotation code disc (6), the detection device is used for identifying the code disc hollow parts (8) when the crystal rotation code disc (6) rotates, outputting a first signal when the code disc hollow parts are identified, and outputting a second signal when the code disc hollow parts are not identified, and the judging assembly is used for receiving the first signal and the second signal, and calculating the rotation error of the rotating assembly according to the difference between the number of the received first signal and the second signal and the theoretical number, so as to obtain the rotation precision of the rotating assembly.

2. The pull head rotation accuracy measurement system of claim 1, wherein, The detection device comprises a first photoelectric limit switch (4) and a second photoelectric limit switch (5), the first photoelectric limit switch (4) outputs the first signal when the code disc hollow parts are identified, and the second photoelectric limit switch (5) outputs the second signal when the code disc hollow parts are not identified.

3. The pull head rotation accuracy measurement system of claim 2, wherein, When the number of the code disc hollow parts (8) is greater than 500, the measurement precision of the pulling head rotation precision measurement system is greater than 1 / 1000.

4. The puller head rotation accuracy measurement system of claim 1, wherein, The power assembly comprises a servo motor (1) and a multi-wedge belt (2), and the servo motor (1) drives the rotating assembly (3) to rotate through the multi-wedge belt (2).

5. The pull head rotation accuracy measurement system of claim 2, wherein, The first photoelectric limit switch (4) and the second photoelectric limit switch (5) are installed on an adjusting support (7), and the relative positions of the first photoelectric limit switch (4) and the second photoelectric limit switch (5) and the crystal rotation code disc (6) are adjusted through the adjusting support (7).

6. The puller head rotation accuracy measurement system of claim 5, wherein, Two adjacent code disc hollow parts (8) are code disc solid parts (9), the first photoelectric limit switch (4) outputs the first signal when the code disc hollow parts are identified, and the second photoelectric limit switch (5) outputs the second signal when the code disc solid parts are identified.

7. A measurement method using the rotation accuracy measurement system of claim 1, characterized by, The application further discloses a method for measuring the rotation precision of a pulling head, which comprises the following steps: Step 1: determining the rotating speed of the rotating assembly; Step 2: driving the rotating assembly to rotate through the power assembly, and receiving the first signal and the second signal output by the detection device; Step 3: selecting a measurement time period, obtaining the actual value of the total number of the received first signal and second signal in the measurement time period, calculating the theoretical value of the total number of the first signal and the second signal that should be received according to the rotating speed of the rotating assembly and the length of the measurement time period, and calculating the difference between the actual value and the theoretical value, and obtaining the rotation precision of the rotating assembly according to the ratio of the difference to the theoretical value. Two adjacent code disc hollow parts (8) are code disc solid parts (9), the detection device outputs the first signal when the code disc hollow parts are identified, and the detection device outputs the second signal when the code disc solid parts are identified.

8. The measurement method according to claim 7, characterized in that, When the number of the code disc hollow parts (8) is greater than 500, the measurement precision of the pulling head rotation precision measurement system is greater than 1 / 1000.

9. The measurement method according to claim 8, characterized in that, ​ 10. The measurement method according to claim 9, characterized by, The crystal conversion code disc (6) is uniformly provided with 502 code disc hollow parts (8) and 502 code disc solid parts (9) on the outer periphery, the length of the measurement time period is selected as the time of one rotation of the rotating assembly, the actual value of the total number of the first signals and the second signals received in the measurement time period is C, and the rotation accuracy calculation formula is: When the actual value C is in the range of 1003-1005, the rotation accuracy of the rotating assembly is less than one thousandth.

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