Calibration detection device of crystal growth furnace thermodetector

Abstract

The embodiment of the specification discloses a calibration detection device for a crystal growth furnace thermodetector, which comprises a crystal growth furnace temperature measurement unit, a calibration unit and a detection unit, and is characterized in that the crystal growth furnace temperature measurement unit comprises the crystal growth furnace thermodetector; wherein the crystal growth furnace temperature measuring unit is used for collecting temperature information and analog quantity output signals; the calibration unit calibrates the crystal growth furnace temperature measurement unit based on the analog quantity output signal, so that the crystal growth furnace temperature measurement unit obtains accurate temperature information; and the detection unit performs detection based on the communication state of the corresponding communication interface of the temperature information so as to obtain the stability of temperature acquisition in the operation process of the crystal growth furnace temperature measurement unit. According to the calibration detection device of the crystal growth furnace thermodetector, it can be ensured that the temperature measurement unit provides accurate temperature information, so that the temperature control precision in the silicon carbide single crystal growth process is improved, and crystal defects are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of crystal growth furnace temperature measurement, and in particular to a calibration detection device for a crystal growth furnace temperature measuring instrument. Background Art

[0002] With the rapid development of modern electronic technology, the requirements for semiconductor materials are getting higher and higher. As a third-generation semiconductor material with excellent performance, silicon carbide has broad application prospects in aerospace, 5G, Internet of Things and other communication fields due to its high breakdown electric field, high saturated electron velocity, high thermal conductivity, high electron density, high mobility, etc. The preparation of silicon carbide single crystals has become an important technical bottleneck in related industries.

[0003] The method for preparing silicon carbide single crystals mainly adopts the physical vapor transport method (PVT method). This method needs to be carried out under vacuum and high temperature conditions. The temperature gradient drives the gasification of silicon carbide powder to generate gas phase components that recrystallize and grow on the substrate seed crystal. After a long growth process, a thicker silicon carbide ingot is finally obtained.

[0004] However, in the process of silicon carbide single crystal growth, temperature control in the growth furnace reaction chamber is crucial. As a temperature measurement sensor, the thermometer is directly related to the measurement and control of the temperature of the growth furnace reaction chamber, and its working state directly affects the crystal quality. When temperature control deviates or is abnormal, it may lead to defects such as crystal inclusions, microtubes, and dislocations, which seriously affect the growth quality of the crystal.

[0005] In the prior art, there is a lack of effective methods for calibration and testing of thermometers, resulting in low calibration and testing efficiency. Summary of the invention

[0006] One or more embodiments of the present specification provide a calibration detection device for a crystal growth furnace temperature measuring instrument, which is used to solve the technical problems raised by the background technology.

[0007] One or more embodiments of this specification adopt the following technical solutions:

[0008] One or more embodiments of the present specification provide a crystal growth furnace temperature measuring instrument calibration detection device, comprising: a crystal growth furnace temperature measuring unit, a calibration unit and a detection unit, wherein the crystal growth furnace temperature measuring unit comprises a crystal growth furnace temperature measuring instrument; wherein,

[0009] The crystal growth furnace temperature measurement unit is used to collect temperature information and output analog signals;

[0010] The calibration unit calibrates the crystal growth furnace temperature measurement unit based on the analog output signal, so that the crystal growth furnace temperature measurement unit obtains accurate temperature information;

[0011] The detection unit performs detection based on the communication status of the communication interface corresponding to the temperature information to obtain the stability of temperature collection during the operation of the crystal growth furnace temperature measurement unit.

[0012] It should be noted that the embodiments of this specification have the following beneficial effects through the above contents:

[0013] Improve temperature measurement accuracy: Through the calibration detection device of the crystal growth furnace temperature meter, it can be ensured that the temperature measurement unit provides accurate temperature information, thereby improving the accuracy of temperature control during the growth of silicon carbide single crystals and reducing the generation of crystal defects.

[0014] Improve production efficiency: Through efficient calibration and detection methods, the calibration time can be shortened, the calibration efficiency of the thermometer can be improved, and the downtime in the production process can be reduced, thereby improving the overall production efficiency.

[0015] Ensure product quality: Accurate temperature measurement and stable temperature acquisition help ensure the quality of silicon carbide single crystals, reduce defects caused by improper temperature control, and improve product consistency and reliability.

[0016] Temperature acquisition stability detection: By detecting the communication status of the communication interface, the operating status of the temperature measurement unit can be monitored in real time to ensure the stability and reliability of the temperature data.

[0017] Automation of the calibration process: The automated design of the calibration unit simplifies the calibration process, reduces human errors, and improves the efficiency and accuracy of calibration.

[0018] Integration of calibration and testing: Integrating calibration and testing functions into one device reduces the complexity of the equipment and facilitates operation and maintenance.

[0019] Furthermore, the device further comprises a programmable logic controller PLC, and the communication interface comprises a serial interface;

[0020] The PLC acquires the temperature information through the serial interface to obtain a first communication state of the serial interface;

[0021] The detection unit is specifically used for:

[0022] Detection is performed based on the first communication state to obtain the stability of temperature collection during the operation of the crystal growth furnace temperature measurement unit.

[0023] It should be noted that the embodiments of this specification have the following beneficial effects through the above contents:

[0024] Real-time monitoring and feedback: PLC can monitor the working condition of the temperature measuring unit of the crystal growth furnace in real time by acquiring temperature information and communication status, and provide timely feedback when abnormalities are detected, facilitating rapid response and adjustment.

[0025] Improve the detection effect of the detection unit: The detection unit performs detection based on the communication status provided by the PLC, which can more accurately evaluate the temperature acquisition stability of the crystal growth furnace temperature measurement unit, thereby improving the accuracy and reliability of the detection.

[0026] Improve communication stability: The serial interface ensures the stability and accuracy of data transmission between the crystal growth furnace temperature measurement unit and PLC with its strong anti-interference ability, long transmission distance and high communication rate.

[0027] Realize automatic control: The addition of PLC makes the entire thermometer calibration and testing process more automated, reduces manual intervention, and improves production efficiency and accuracy.

[0028] Easy to integrate and expand: The standardized design of the serial interface makes the device easy to integrate with other systems or equipment, and also facilitates future system expansion and upgrades.

[0029] Further, the serial interface is an RS485 / 422 interface, and the detection unit is specifically used for:

[0030] When the crystal growth furnace temperature measurement unit collects the temperature information, querying the temperature information through the RS485 / 422 interface;

[0031] Determine whether the RS485 / 422 interface returns temperature information;

[0032] If not, record the number of packet losses, and determine the packet loss rate of the RS485 / 422 interface based on the number of packet losses;

[0033] If yes, store the temperature information, determine an abnormal temperature based on the temperature information, and determine a bit error rate of the RS485 / 422 interface based on the abnormal temperature;

[0034] Based on the packet loss rate of the RS485 / 422 interface and the bit error rate of the RS485 / 422 interface, the RS485 / 422 interface is judged to obtain the stability of temperature collection during the operation of the crystal growth furnace temperature measurement unit.

[0035] It should be noted that the embodiments of this specification have the following beneficial effects through the above contents:

[0036] Improve communication reliability: Through real-time monitoring of the RS485 / 422 interface by the detection unit, the reliability of the interface in transmitting temperature information can be evaluated, thereby improving the communication stability of the entire temperature measurement system.

[0037] Real-time monitoring of data integrity: By querying temperature information and determining whether the RS485 / 422 interface returns information, the integrity of data transmission can be monitored in real time to ensure that no data is lost.

[0038] Packet loss rate analysis: By recording the number of packet losses and calculating the packet loss rate, the transmission errors of the communication interface can be quantified to help maintenance personnel quickly locate and solve problems.

[0039] Bit error rate analysis: By detecting abnormal data in the temperature information, the bit error rate of the RS485 / 422 interface can be calculated to further evaluate the communication quality.

[0040] Abnormal temperature detection: By storing temperature information and analyzing abnormal temperatures, possible temperature measurement errors in the crystal growth furnace temperature measurement unit can be discovered in a timely manner to ensure measurement accuracy.

[0041] System stability evaluation: By judging the RS485 / 422 interface based on the packet loss rate and bit error rate, the temperature acquisition stability of the crystal growth furnace temperature measurement unit during operation can be comprehensively evaluated, providing a basis for system maintenance and optimization.

[0042] Further, the device also includes an Ethernet switch, and the communication interface includes an Ethernet interface;

[0043] The Ethernet switch acquires the temperature information through the Ethernet interface to obtain a second communication state of the Ethernet interface;

[0044] The detection unit is specifically used for:

[0045] Detection is performed based on the second communication state to obtain the stability of temperature collection during the operation of the crystal growth furnace temperature measurement unit.

[0046] It should be noted that the embodiments of this specification have the following beneficial effects through the above contents:

[0047] Improve network communication efficiency: Ethernet switches can optimize network traffic, reduce data transmission delays, and improve the overall efficiency of network communications.

[0048] Expand network coverage: The Ethernet interface supports a longer transmission distance, and data exchange between multiple devices can be achieved through switches, thereby expanding network coverage.

[0049] Support for a wider range of device connections: Ethernet interface is a widely used communication interface in the field of industrial automation, which makes the device compatible with a variety of devices and easy to integrate into existing industrial control systems.

[0050] Improve data security: Ethernet switches usually have certain security features, such as port security and MAC address filtering, which can enhance the security of data transmission.

[0051] Real-time monitoring of communication status: By monitoring the second communication status of the Ethernet interface through the detection unit, the transmission status of the temperature information can be understood in real time, and problems can be discovered and solved in time.

[0052] Optimize system performance: By detecting the communication status of the Ethernet interface, the operating performance of the crystal growth furnace temperature measurement unit can be optimized to ensure the stability of temperature acquisition.

[0053] Furthermore, the detection unit is specifically used for:

[0054] When the crystal growth furnace temperature measurement unit collects the temperature information, querying the temperature information through the Ethernet interface;

[0055] Determining whether the Ethernet interface returns temperature information;

[0056] If not, record the number of packet losses, and determine the packet loss rate of the Ethernet interface based on the number of packet losses;

[0057] If yes, store the temperature information, determine an abnormal temperature based on the temperature information, and determine a bit error rate of the Ethernet interface based on the abnormal temperature;

[0058] Based on the packet loss rate of the Ethernet interface and the bit error rate of the Ethernet interface, the Ethernet interface is judged to obtain the stability of temperature collection during the operation of the crystal growth furnace temperature measurement unit.

[0059] It should be noted that the embodiments of this specification have the following beneficial effects through the above contents:

[0060] Communication stability guarantee: Through real-time monitoring of the Ethernet interface by the detection unit, the stability of the temperature collection data of the crystal growth furnace temperature measurement unit during operation is ensured, reducing the measurement errors caused by communication problems.

[0061] Real-time fault diagnosis: The detection unit can detect the communication status of the Ethernet interface in real time. Once packet loss is found, it can immediately record and calculate the packet loss rate, which is convenient for rapid diagnosis and location of communication faults.

[0062] Data integrity verification: By determining whether the Ethernet interface returns temperature information, the integrity of the data can be verified to ensure that the transmitted data has not been tampered with or lost.

[0063] Bit error rate analysis: When temperature information is detected, the abnormal temperature is determined by analyzing the abnormal data in the temperature information, and then the bit error rate of the Ethernet interface is calculated, which is crucial for evaluating communication quality.

[0064] System performance optimization: By analyzing the packet loss rate and bit error rate of the Ethernet interface, the network configuration can be optimized and the transmission performance of the communication interface can be improved, thereby improving the performance of the entire crystal growth furnace temperature measurement system.

[0065] Preventive maintenance: By regularly monitoring the communication status, potential network problems can be discovered in advance, and preventive maintenance can be performed to reduce system downtime.

[0066] Furthermore, the device also includes a PLC;

[0067] The PLC is used to collect the analog output signal output by the temperature measuring unit of the crystal growth furnace in real time and store it in the corresponding register;

[0068] The calibration unit is specifically used for:

[0069] Based on the analog output signal stored in the PLC and a preset theoretical output curve, the crystal growth furnace temperature measurement unit is calibrated so that the crystal growth furnace temperature measurement unit obtains accurate temperature information. The theoretical output curve is determined by multiple ideal output signals.

[0070] It should be noted that the embodiments of this specification have the following beneficial effects through the above contents:

[0071] Improve measurement accuracy: The analog output signals of the crystal growth furnace temperature measuring unit are collected in real time through PLC. The calibration unit can perform accurate calibration based on these signals and the preset theoretical output curve, thereby improving the temperature measurement accuracy of the temperature measuring unit.

[0072] Real-time data storage and processing: The real-time data acquisition and storage function of PLC ensures that the calibration process can be analyzed based on the latest data, reducing the impact of data delay on the calibration results.

[0073] Automated calibration process: The use of PLC automates the calibration process, reduces manual intervention, and improves calibration efficiency and consistency.

[0074] Accuracy of the theoretical output curve: By using a theoretical output curve determined from multiple ideal output signals, the calibration unit can more accurately simulate the temperature response under ideal conditions, providing a more reliable calibration benchmark.

[0075] Reliability of calibration results: The calibration method based on the theoretical output curve can reduce human errors and improve the reliability of calibration results.

[0076] Improved system stability: Regular calibration can ensure the long-term stability of the crystal growth furnace temperature measurement unit and reduce measurement deviations caused by equipment aging or environmental factors.

[0077] Further, the analog output signal includes analog current value and analog temperature output data; the theoretical output signal includes theoretical current value and theoretical temperature output data; the analog output signal is provided with a plurality of;

[0078] The calibration unit is specifically used for:

[0079] Determine a current output curve based on the analog output signal stored in the PLC;

[0080] Based on the theoretical output curve, determining the analog offset that needs to be corrected for the current output curve;

[0081] The analog offset is sent to the crystal growth furnace temperature measurement unit so that the crystal growth furnace temperature measurement unit is calibrated based on the analog offset.

[0082] It should be noted that the embodiments of this specification have the following beneficial effects through the above contents:

[0083] Precise calibration: By using analog output signals (including analog current values ​​and analog temperature output data) and theoretical output signals (including theoretical current values ​​and theoretical temperature output data), the calibration unit can perform more precise calibration to ensure that the crystal growth furnace temperature measurement unit provides accurate temperature readings.

[0084] Dynamic calibration: By real-time acquisition of multiple analog output signals and determining the current output curve, the calibration unit can dynamically calibrate the crystal growth furnace temperature measurement unit to adapt to different working conditions and environmental changes.

[0085] Automatic correction: The calibration unit can automatically determine the offset between the current output curve and the theoretical output curve, and automatically generate a correction plan, reducing manual intervention and improving calibration efficiency.

[0086] System adaptability: By sending analog offsets to the crystal growth furnace temperature measurement unit, the system can adapt to different measurement requirements and equipment characteristics, increasing the versatility and adaptability of the system.

[0087] Improve system reliability: Regular or automatic calibration processes help maintain the long-term stability and reliability of the crystal growth furnace temperature measurement unit and reduce measurement errors.

[0088] Furthermore, the device also includes a working condition PC; the working condition PC is connected to the communication interface;

[0089] The working condition PC sends and queries the calibration command of the crystal growth furnace temperature measuring unit by querying and modifying the internal register data of the crystal growth furnace temperature measuring unit.

[0090] It should be noted that the embodiments of this specification have the following beneficial effects through the above contents:

[0091] Remote calibration control: The addition of a working PC allows calibration operations to be performed remotely without direct contact with the crystal growth furnace temperature measurement unit, improving the safety and convenience of operation.

[0092] Convenient data interaction: Through the connection between the working PC and the communication interface, the query and modification of the internal register data of the crystal growth furnace temperature measurement unit are realized, which facilitates data interaction and processing.

[0093] Further, the device also includes an oscilloscope;

[0094] The oscilloscope is used to electrically connect the measuring probe to the serial interface of the communication interface and detect the communication level quality of the serial interface, wherein the communication level quality of the serial interface is used to indicate the state of the serial interface.

[0095] It should be noted that the embodiments of this specification have the following beneficial effects through the above contents:

[0096] Enhanced communication quality monitoring: The addition of an oscilloscope enables the system to detect the communication level quality of the serial interface in real time, thereby having an intuitive understanding of the status of the communication interface and ensuring the stability and reliability of data transmission.

[0097] Improve diagnostic capabilities: An oscilloscope can be used to observe and analyze changes in communication levels, which helps to quickly diagnose communication interface faults and improve the system's fault diagnosis capabilities.

[0098] Ensure data integrity: Detecting the communication level quality of the serial interface can ensure data integrity and prevent temperature information loss or errors caused by poor communication quality.

[0099] Furthermore, the serial interface has a built-in surge absorption circuit and a common-mode interference suppression circuit.

[0100] It should be noted that the embodiments of this specification have the following beneficial effects through the above contents:

[0101] Improve the interface's anti-interference ability: The built-in surge absorption circuit can effectively suppress voltage spikes caused by power supply voltage fluctuations or external electromagnetic interference, protecting the serial interface from damage.

[0102] Enhance system stability: Common-mode interference suppression circuit can reduce the impact of common-mode interference on communication signals and improve system stability and reliability.

[0103] Prolong equipment life: Due to the protection of surge absorption circuit and common mode interference suppression circuit, the life of serial interface and its connected equipment can be extended.

[0104] At least one of the above technical solutions adopted in the embodiments of this specification can achieve the following beneficial effects:

[0105] Improve temperature measurement accuracy: Through the calibration detection device of the crystal growth furnace temperature meter, it can be ensured that the temperature measurement unit provides accurate temperature information, thereby improving the accuracy of temperature control during the growth of silicon carbide single crystals and reducing the generation of crystal defects.

[0106] Improve production efficiency: Through efficient calibration and detection methods, the calibration time can be shortened, the calibration efficiency of the thermometer can be improved, and the downtime in the production process can be reduced, thereby improving the overall production efficiency.

[0107] Ensure product quality: Accurate temperature measurement and stable temperature acquisition help ensure the quality of silicon carbide single crystals, reduce defects caused by improper temperature control, and improve product consistency and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0108] In order to more clearly illustrate the technical solutions in the embodiments of this specification or the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art description. Obviously, the drawings described below are only some embodiments recorded in this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. In the drawings:

[0109] Figure 1 A schematic diagram of a flow chart of a calibration detection device for a crystal growth furnace temperature measuring instrument provided in one or more embodiments of this specification;

[0110] Figure 2 A schematic diagram of the structure of a calibration detection device for a crystal growth furnace temperature measuring instrument provided in one or more embodiments of this specification;

[0111] Figure 3 A schematic diagram of the structure of an isolated power converter provided in one or more embodiments of this specification;

[0112] Figure 4 A schematic diagram of RS485 / 422 bus anti-interference design provided for one or more embodiments of this specification;

[0113] Figure 5 A flow chart of packet loss rate and bit error rate detection provided for one or more embodiments of this specification;

[0114] Figure 6A schematic diagram of RS485 communication test provided for one or more embodiments of this specification;

[0115] Figure 7 A schematic diagram of a normal signal waveform provided for one or more embodiments of this specification;

[0116] Figure 8 A schematic diagram of a standard slope curve and a common abnormal slope curve provided for one or more embodiments of this specification;

[0117] Fig. 9 A schematic diagram of a standard slope curve and a common abnormal slope curve provided for one or more embodiments of this specification;

[0118] Fig.10 A schematic diagram of a standard slope curve and a common abnormal slope curve provided for one or more embodiments of this specification. DETAILED DESCRIPTION

[0119] The embodiments of this specification provide a calibration detection device for a crystal growth furnace temperature measuring instrument.

[0120] In order to enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below in conjunction with the drawings in the embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this specification, not all of the embodiments. Based on the embodiments of this specification, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of this specification.

[0121] Figure 1 A calibration and detection device for a crystal growth furnace temperature meter provided in one or more embodiments of this specification may include: a crystal growth furnace temperature measurement unit 101, a calibration unit 102 and a detection unit 103, wherein the crystal growth furnace temperature measurement unit 101 has a built-in crystal growth furnace temperature meter.

[0122] Among them, the crystal growth furnace temperature measuring unit 101 can be used to collect temperature information and analog output signals; the calibration unit 102 calibrates the crystal growth furnace temperature measuring unit based on the analog output signal so that the crystal growth furnace temperature measuring unit 101 obtains accurate temperature information; the detection unit 103 detects the communication status of the communication interface corresponding to the temperature information to obtain the stability of temperature collection during the operation of the crystal growth furnace temperature measuring unit.

[0123] In the embodiments of this specification, regarding the crystal growth furnace temperature measuring unit 101, the following specific implementation scheme can be adopted:

[0124] The crystal growth furnace temperature measurement unit 101 may include an infrared thermometer. The infrared thermometer is installed at a specific position of the crystal growth furnace to ensure that the infrared thermometer can accurately reflect the temperature in the furnace. The infrared thermometer collects temperature information and outputs analog signals

[0125] In the embodiments of this specification, the calibration unit 102 may be implemented as follows:

[0126] The calibration unit 102 calibrates the crystal growth furnace temperature measurement unit based on the analog output signal by applying the built-in calibration algorithm.

[0127] In the embodiments of this specification, the detection unit 103 can be implemented as follows:

[0128] For the detection unit 103, the temperature information of the crystal growth furnace temperature measurement unit 101 can be received through the communication interface. The fluctuation of the temperature information is analyzed in real time, and the stability index of the temperature acquisition is calculated using the stability evaluation algorithm. The stability index is compared with a preset threshold to determine whether the operation of the crystal growth furnace temperature measurement unit 101 is stable. If the stability index exceeds the threshold, an alarm can be triggered or corresponding compensation measures can be taken.

[0129] Furthermore, the device of the embodiment of the present specification may also include a programmable logic controller PLC, and the communication interface includes a serial interface. The PLC obtains the temperature information through the serial interface to obtain a first communication state of the serial interface; the detection unit is specifically used to: perform detection based on the first communication state to obtain the stability of temperature acquisition during the operation of the crystal growth furnace temperature measurement unit.

[0130] It should be noted that a PLC is integrated in the device of the embodiment of this specification, and the PLC is equipped with a serial communication interface module. Program code is written to enable the PLC to read the temperature information on the serial interface, wherein the serial interface can be an RS485 / 422 interface.

[0131] It should be noted that the detection unit of the embodiment of this specification can be an independent module or integrated in the PLC. Write a detection program to enable the PLC to detect the first communication state of the serial interface, and evaluate the temperature acquisition stability of the crystal growth furnace temperature measurement unit according to the detection result. The detection logic of the communication state implemented by the detection unit may include the following contents:

[0132] Check the integrity of the communication signal to ensure that no data is damaged or lost;

[0133] Monitor communication frequency and response time to ensure real-time communication;

[0134] Detect the error rate during communication, such as frame error, parity error, etc.

[0135] Regarding stability assessment, the following specific implementation scheme can be adopted:

[0136] Set stability thresholds and trigger alarms when communication status exceeds these thresholds. If communication instability is detected, the PLC can take measures such as: resending the request to obtain new temperature information. Recording communication errors and stability issues for subsequent analysis.

[0137] It should be noted that the embodiments of this specification have the following beneficial effects through the above contents:

[0138] Real-time monitoring and feedback: PLC can monitor the working condition of the temperature measuring unit of the crystal growth furnace in real time by acquiring temperature information and communication status, and provide timely feedback when abnormalities are detected, facilitating rapid response and adjustment.

[0139] Improve the detection effect of the detection unit: The detection unit performs detection based on the communication status provided by the PLC, which can more accurately evaluate the temperature acquisition stability of the crystal growth furnace temperature measurement unit, thereby improving the accuracy and reliability of the detection.

[0140] Improve communication stability: The serial interface ensures the stability and accuracy of data transmission between the crystal growth furnace temperature measurement unit and PLC with its strong anti-interference ability, long transmission distance and high communication rate.

[0141] Realize automatic control: The addition of PLC makes the entire thermometer calibration and testing process more automated, reduces manual intervention, and improves production efficiency and accuracy.

[0142] Easy to integrate and expand: The standardized design of the serial interface makes the device easy to integrate with other systems or equipment, and also facilitates future system expansion and upgrades.

[0143] Furthermore, the serial interface is an RS485 / 422 interface, and the detection unit is specifically used to: when the crystal growth furnace temperature measurement unit collects the temperature information, query the temperature information through the RS485 / 422 interface; determine whether the RS485 / 422 interface returns the temperature information; if not, record the number of packet losses, and determine the packet loss rate of the RS485 / 422 interface based on the number of packet losses; if so, store the temperature information, determine the abnormal temperature based on the temperature information, and determine the bit error rate of the RS485 / 422 interface based on the abnormal temperature; based on the packet loss rate of the RS485 / 422 interface and the bit error rate of the RS485 / 422 interface, judge the RS485 / 422 interface to obtain the stability of temperature collection during the operation of the crystal growth furnace temperature measurement unit.

[0144] It should be noted that the above content can be implemented through the following specific implementation plans:

[0145] Send a query command to the crystal growth furnace temperature measurement unit through the RS485 / 422 interface to request temperature information. Monitor the RS485 / 422 interface to determine whether the temperature information is received. If the temperature information is not received, it is considered that packet loss has occurred. When packet loss is detected, increase the packet loss counter. Calculate the packet loss rate based on the number of packet losses and the total number of query commands. If the temperature information is successfully received, store this information. Analyze the stored temperature information to determine whether there is an abnormal temperature value. If an abnormal temperature is detected, calculate the ratio of the abnormal temperature value to the normal temperature value to determine the bit error rate. Evaluate the performance of the RS485 / 422 interface based on the calculated packet loss rate and bit error rate. Set thresholds for the packet loss rate and bit error rate. If these thresholds are exceeded, it is determined that there is a performance problem with the interface.

[0146] It should be noted that the embodiments of this specification have the following beneficial effects through the above contents:

[0147] Improve communication reliability: Through real-time monitoring of the RS485 / 422 interface by the detection unit, the reliability of the interface in transmitting temperature information can be evaluated, thereby improving the communication stability of the entire temperature measurement system.

[0148] Real-time monitoring of data integrity: By querying temperature information and determining whether the RS485 / 422 interface returns information, the integrity of data transmission can be monitored in real time to ensure that no data is lost.

[0149] Packet loss rate analysis: By recording the number of packet losses and calculating the packet loss rate, the transmission errors of the communication interface can be quantified to help maintenance personnel quickly locate and solve problems.

[0150] Bit error rate analysis: By detecting abnormal data in the temperature information, the bit error rate of the RS485 / 422 interface can be calculated to further evaluate the communication quality.

[0151] Abnormal temperature detection: By storing temperature information and analyzing abnormal temperatures, possible temperature measurement errors in the crystal growth furnace temperature measurement unit can be discovered in a timely manner to ensure measurement accuracy.

[0152] System stability evaluation: By judging the RS485 / 422 interface based on the packet loss rate and bit error rate, the temperature acquisition stability of the crystal growth furnace temperature measurement unit during operation can be comprehensively evaluated, providing a basis for system maintenance and optimization.

[0153] Furthermore, the device also includes an Ethernet switch, and the communication interface includes an Ethernet interface; the Ethernet switch obtains the temperature information through the Ethernet interface to obtain a second communication state of the Ethernet interface; the detection unit is specifically used to: perform detection based on the second communication state to obtain the stability of temperature collection during the operation of the crystal growth furnace temperature measurement unit.

[0154] It should be noted that the above content can be implemented through the following specific implementation plans:

[0155] An Ethernet switch is integrated in the device, and the crystal growth furnace temperature measurement unit should have an Ethernet interface to facilitate communication through the Ethernet switch.

[0156] The detection unit of the embodiment of this specification can be an independent module or integrated in the Ethernet switch. Write a detection program to enable the Ethernet switch to detect the second communication state of the Ethernet interface, and evaluate the temperature acquisition stability of the crystal growth furnace temperature measurement unit according to the detection result. The detection logic of the communication state implemented by the detection unit may include the following contents:

[0157] Check the integrity of the communication signal to ensure that no data is damaged or lost;

[0158] Monitor communication frequency and response time to ensure real-time communication;

[0159] Detect the error rate during communication, such as frame error, parity error, etc.

[0160] Regarding stability assessment, the following specific implementation scheme can be adopted:

[0161] Set stability thresholds and trigger alarms when communication status exceeds these thresholds. If unstable communication is detected, the Ethernet switch can take measures such as: resending requests to obtain new temperature information. Recording communication errors and stability issues for subsequent analysis.

[0162] It should be noted that the embodiments of this specification have the following beneficial effects through the above contents:

[0163] Improve network communication efficiency: Ethernet switches can optimize network traffic, reduce data transmission delays, and improve the overall efficiency of network communications.

[0164] Expand network coverage: The Ethernet interface supports a longer transmission distance, and data exchange between multiple devices can be achieved through switches, thereby expanding network coverage.

[0165] Support for a wider range of device connections: Ethernet interface is a widely used communication interface in the field of industrial automation, which makes the device compatible with a variety of devices and easy to integrate into existing industrial control systems.

[0166] Improve data security: Ethernet switches usually have certain security features, such as port security and MAC address filtering, which can enhance the security of data transmission.

[0167] Real-time monitoring of communication status: By monitoring the second communication status of the Ethernet interface through the detection unit, the transmission status of the temperature information can be understood in real time, and problems can be discovered and solved in time.

[0168] Optimize system performance: By detecting the communication status of the Ethernet interface, the operating performance of the crystal growth furnace temperature measurement unit can be optimized to ensure the stability of temperature acquisition.

[0169] Furthermore, the detection unit is specifically used to: when the crystal growth furnace temperature measurement unit collects the temperature information, query the temperature information through the Ethernet interface; determine whether the Ethernet interface returns the temperature information; if not, record the number of packet losses, and determine the packet loss rate of the Ethernet interface based on the number of packet losses; if so, store the temperature information, determine the abnormal temperature based on the temperature information, and determine the bit error rate of the Ethernet interface based on the abnormal temperature; based on the packet loss rate of the Ethernet interface and the bit error rate of the Ethernet interface, judge the Ethernet interface to obtain the stability of temperature collection during the operation of the crystal growth furnace temperature measurement unit.

[0170] It should be noted that regarding the judgment of the Ethernet interface to obtain the stability of temperature collection during the operation of the crystal growth furnace temperature measurement unit, you can refer to the above judgment of the RS485 / 422 interface to obtain the stability of temperature collection during the operation of the crystal growth furnace temperature measurement unit.

[0171] It should be noted that the embodiments of this specification have the following beneficial effects through the above contents:

[0172] Communication stability guarantee: Through real-time monitoring of the Ethernet interface by the detection unit, the stability of the temperature collection data of the crystal growth furnace temperature measurement unit during operation is ensured, reducing the measurement errors caused by communication problems.

[0173] Real-time fault diagnosis: The detection unit can detect the communication status of the Ethernet interface in real time. Once packet loss is found, it can immediately record and calculate the packet loss rate, which is convenient for rapid diagnosis and location of communication faults.

[0174] Data integrity verification: By determining whether the Ethernet interface returns temperature information, the integrity of the data can be verified to ensure that the transmitted data has not been tampered with or lost.

[0175] Bit error rate analysis: When temperature information is detected, the abnormal temperature is determined by analyzing the abnormal data in the temperature information, and then the bit error rate of the Ethernet interface is calculated, which is crucial for evaluating communication quality.

[0176] System performance optimization: By analyzing the packet loss rate and bit error rate of the Ethernet interface, the network configuration can be optimized and the transmission performance of the communication interface can be improved, thereby improving the performance of the entire crystal growth furnace temperature measurement system.

[0177] Preventive maintenance: By regularly monitoring the communication status, potential network problems can be discovered in advance, and preventive maintenance can be performed to reduce system downtime.

[0178] Furthermore, the device of the embodiment of the present specification also includes a PLC; the PLC can be used to collect the analog output signal output by the crystal growth furnace temperature measuring unit in real time and store it in a corresponding register; the calibration unit is specifically used to: calibrate the crystal growth furnace temperature measuring unit based on the analog output signal stored in the PLC and a preset theoretical output curve, so that the crystal growth furnace temperature measuring unit obtains accurate temperature information, and the theoretical output curve is determined by multiple ideal output signals.

[0179] It should be noted that the above content can be implemented through the following specific implementation plans:

[0180] The PLC (Programmable Logic Controller) may include an analog input (AI) module to read the analog output signal of the crystal growth furnace temperature measurement unit. The crystal growth furnace temperature measurement unit may include an analog output interface for outputting an analog output signal related to temperature information. The calibration unit may be pre-installed with a calibration program for performing a calibration process.

[0181] PLC program: Write a PLC program to enable it to read data from the analog output signal interface of the crystal growth furnace temperature measurement unit and store the read analog signal into the analog input register of the PLC.

[0182] Calibration procedure for calibration unit: Develop a calibration procedure for the calibration unit, which can receive the analog output signal stored in the PLC. The calibration procedure contains a preset theoretical output curve, which is determined by multiple ideal output signals. The theoretical output curve can be determined based on experimental data or data provided by the manufacturer. The calibration unit can be an independent module or integrated in the PLC.

[0183] Calibration process: The calibration procedure of the calibration unit compares the analog output signal read by the PLC with the theoretical output curve. If there is a deviation, the program will calibrate. After calibration, the analog output signal is collected again and compared with the theoretical output curve. Verify the calibration effect and ensure that the temperature measurement unit provides accurate temperature information.

[0184] It should be noted that the embodiments of this specification have the following beneficial effects through the above contents:

[0185] Improve measurement accuracy: The analog output signals of the crystal growth furnace temperature measuring unit are collected in real time through PLC. The calibration unit can perform accurate calibration based on these signals and the preset theoretical output curve, thereby improving the temperature measurement accuracy of the temperature measuring unit.

[0186] Real-time data storage and processing: The real-time data acquisition and storage function of PLC ensures that the calibration process can be analyzed based on the latest data, reducing the impact of data delay on the calibration results.

[0187] Automated calibration process: The use of PLC automates the calibration process, reduces manual intervention, and improves calibration efficiency and consistency.

[0188] Accuracy of the theoretical output curve: By using a theoretical output curve determined from multiple ideal output signals, the calibration unit can more accurately simulate the temperature response under ideal conditions, providing a more reliable calibration benchmark.

[0189] Reliability of calibration results: The calibration method based on the theoretical output curve can reduce human errors and improve the reliability of calibration results.

[0190] Improved system stability: Regular calibration can ensure the long-term stability of the crystal growth furnace temperature measurement unit and reduce measurement deviations caused by equipment aging or environmental factors.

[0191] Furthermore, the analog output signal includes an analog current value and an analog temperature output data; the theoretical output signal includes a theoretical current value and a theoretical temperature output data; there are multiple analog output signals; the calibration unit is specifically used to: determine the current output curve based on the analog output signal stored in the PLC; determine the analog offset that needs to be corrected for the current output curve based on the theoretical output curve; and send the analog offset to the crystal growth furnace temperature measurement unit so that the crystal growth furnace temperature measurement unit can be calibrated based on the analog offset.

[0192] It should be noted that the above content can be implemented through the following specific implementation plans:

[0193] Data collection: PLC collects the analog current value and analog temperature value of the crystal growth furnace temperature measurement unit and stores the collected data in the PLC register.

[0194] Output curve determination: The calibration unit reads the analog output signal from the PLC, analyzes and determines the current output curve.

[0195] Theoretical output curve preparation: Prepare a theoretical output curve, which is based on the simulated current value and simulated temperature value under ideal conditions. The theoretical output curve can be obtained through laboratory testing or data provided by the manufacturer.

[0196] Offset calculation: The calibration unit compares the current output curve with the theoretical output curve and calculates the required analog offset. The offset may include gain adjustment and offset adjustment.

[0197] Send offset: Send the calculated analog offset to the crystal growth furnace temperature measurement unit through PLC. The temperature measurement unit should have the ability to receive and apply these offsets.

[0198] Calibration execution: The crystal growth furnace temperature measurement unit is calibrated according to the received offset and adjusts its internal parameters or output signals.

[0199] Calibration verification: After calibration, the PLC collects the analog output signal again and compares it with the theoretical output curve to verify the calibration effect and ensure the accuracy of the temperature reading.

[0200] It should be noted that the embodiments of this specification have the following beneficial effects through the above contents:

[0201] Precise calibration: By using analog output signals (including analog current values ​​and analog temperature output data) and theoretical output signals (including theoretical current values ​​and theoretical temperature output data), the calibration unit can perform more precise calibration to ensure that the crystal growth furnace temperature measurement unit provides accurate temperature readings.

[0202] Dynamic calibration: By real-time acquisition of multiple analog output signals and determining the current output curve, the calibration unit can dynamically calibrate the crystal growth furnace temperature measurement unit to adapt to different working conditions and environmental changes.

[0203] Automatic correction: The calibration unit can automatically determine the offset between the current output curve and the theoretical output curve, and automatically generate a correction plan, reducing manual intervention and improving calibration efficiency.

[0204] System adaptability: By sending analog offsets to the crystal growth furnace temperature measurement unit, the system can adapt to different measurement requirements and equipment characteristics, increasing the versatility and adaptability of the system.

[0205] Improve system reliability: Regular or automatic calibration processes help maintain the long-term stability and reliability of the crystal growth furnace temperature measurement unit and reduce measurement errors.

[0206] Furthermore, the device also includes a working condition PC; the working condition PC is connected to the communication interface; the working condition PC sends and queries the calibration command of the crystal growth furnace temperature measuring unit by querying and modifying the internal register data of the crystal growth furnace temperature measuring unit.

[0207] It should be noted that the above content can be implemented through the following specific implementation plans:

[0208] Working PC: It can be a personal computer with appropriate configuration, used to run the calibration software and communicate with the temperature measurement unit of the crystal growth furnace.

[0209] Communication interface: one or more communication interfaces, such as Ethernet, serial interface (RS485 / 422) or wireless interface, used to connect the working PC and the crystal growth furnace temperature measurement unit.

[0210] Crystal growth furnace temperature measurement unit: a temperature measurement unit with internal registers that can receive calibration commands and data inquiries.

[0211] Install the communication interface: Install the necessary communication interface hardware, such as a network adapter or serial port adapter, on the working PC.

[0212] Connecting equipment: Use a communication cable to connect the communication interface of the working condition PC with the communication interface of the crystal growth furnace temperature measurement unit.

[0213] Configure communication settings: Configure the communication parameters, including baud rate, data bits, stop bits, and parity bits, in the calibration unit to match the communication settings of the crystal growth furnace temperature measurement unit.

[0214] Run the calibration unit: Start the calibration unit and ensure that the connection between the working PC and the crystal growth furnace temperature measurement unit is stable.

[0215] Query internal registers: Use the calibration unit to query the internal register data of the crystal growth furnace temperature measurement unit to obtain the current temperature measurement settings and status.

[0216] Send calibration commands: According to the calibration parameters that need to be adjusted, calibration commands are sent to the internal registers of the temperature measurement unit through the calibration software. These commands may include temperature correction values, gain adjustments, offset adjustments, etc.

[0217] Confirm that calibration is complete: After the calibration command is sent, the software should provide feedback to confirm that the temperature measurement unit has received and executed the calibration command.

[0218] Verify calibration results: Query the internal registers again to verify that the calibration parameters have been applied correctly. The calibration effect can be verified by comparing the actual measured values ​​with the theoretical values.

[0219] It should be noted that the embodiments of this specification have the following beneficial effects through the above contents:

[0220] Remote calibration control: The addition of a working PC allows calibration operations to be performed remotely without direct contact with the crystal growth furnace temperature measurement unit, improving the safety and convenience of operation.

[0221] Convenient data interaction: Through the connection between the working PC and the communication interface, the query and modification of the internal register data of the crystal growth furnace temperature measurement unit are realized, which facilitates data interaction and processing.

[0222] Furthermore, the device also includes an oscilloscope; the oscilloscope is used to electrically connect the measuring probe to the serial interface of the communication interface, and detect the communication level quality of the serial interface, wherein the communication level quality of the serial interface is used to indicate the state of the serial interface, and the serial interface can be an RS485 / 422 interface. The communication level quality can be the level stability and waveform integrity of the signal during transmission.

[0223] It should be noted that the above content can be implemented through the following specific implementation plans:

[0224] Oscilloscope: One with sufficient bandwidth and resolution to detect the quality of the serial interface communication levels.

[0225] Measuring probe: a measuring probe used to connect to the temperature measuring unit of a crystal growth furnace or other equipment, which can provide a signal compatible with the serial interface.

[0226] Communication interface: RS485 / 422 interface on the device, used for electrical connection with the measuring probe.

[0227] Connect an oscilloscope: Connect the measuring probe of the oscilloscope to the RS485 / 422 interface of the communication interface. Make sure that the connecting cable can correctly transmit RS485 / 422 signals.

[0228] Set oscilloscope parameters: If the oscilloscope has built-in software, you can use the software to set the following parameters:

[0229] Channel: Select the channel to be used for testing the serial interface.

[0230] Amplitude Range: Set the appropriate voltage range to match the communication level of RS485 / 422.

[0231] Time Base: Set the appropriate time base to capture details during the communication process.

[0232] Trigger Settings: Configure the trigger settings to stabilize the displayed signal.

[0233] Check the communication level quality: Turn on the oscilloscope and observe the communication level waveform of the serial interface. Check whether the level is within the specified range (for example, a positive level between +2V and +6V indicates a logic "1", and a negative level between -2V and -6V indicates a logic "0"). Observe whether there is noise, jitter or abnormal waveform, which may indicate poor communication quality.

[0234] Analyze the communication level quality: Based on the waveform analysis, determine whether the serial interface is in good condition. If the communication quality is poor, you may need to check the interface hardware, connection cables, or device settings.

[0235] It should be noted that the embodiments of this specification have the following beneficial effects through the above contents:

[0236] Enhanced communication quality monitoring: The addition of an oscilloscope enables the system to detect the communication level quality of the serial interface in real time, thereby having an intuitive understanding of the status of the communication interface and ensuring the stability and reliability of data transmission.

[0237] Improve diagnostic capabilities: An oscilloscope can be used to observe and analyze changes in communication levels, which helps to quickly diagnose communication interface faults and improve the system's fault diagnosis capabilities.

[0238] Ensure data integrity: Detecting the communication level quality of the serial interface can ensure data integrity and prevent temperature information loss or errors caused by poor communication quality.

[0239] Furthermore, the serial interface has a built-in surge absorption circuit and a common-mode interference suppression circuit.

[0240] It should be noted that the embodiments of this specification have the following beneficial effects through the above contents:

[0241] Improve the interface's anti-interference ability: The built-in surge absorption circuit can effectively suppress voltage spikes caused by power supply voltage fluctuations or external electromagnetic interference, protecting the serial interface from damage.

[0242] Enhance system stability: Common-mode interference suppression circuit can reduce the impact of common-mode interference on communication signals and improve system stability and reliability.

[0243] Prolong equipment life: Due to the protection of surge absorption circuit and common mode interference suppression circuit, the life of serial interface and its connected equipment can be extended.

[0244] It should be noted that the embodiments of this specification relate to a high-efficiency calibration and detection device for a crystal growth furnace thermometer, which can efficiently calibrate and detect the crystal growth furnace thermometer, and efficiently complete the detection of the thermometer's analog output interface, serial interface (RS485 / 422 interface) and Ethernet interface, effectively avoiding a thermometer in poor working condition from being used in a crystal growth furnace, causing irreversible damage to the silicon carbide growth process.

[0245] In combination with the above content, the embodiments of this specification provide a more detailed calibration and detection scheme for the crystal growth furnace temperature measuring instrument. For details, please refer to Figure 2 The structure diagram of the calibration detection device of the crystal growth furnace temperature measuring instrument is shown. The device includes a working PC, a PLC, an infrared thermometer, an oscilloscope, an Ethernet switch and a DC24V power supply. The specific parts are as follows:

[0246] DC24V DC power supply: This part uses a DC / DC isolated power converter to power the thermometer. Figure 3 The structural diagram of the isolated power converter provided in the embodiment of this specification, the isolation voltage of the isolated power supply is not less than 1500V, and the functions of arc interference isolation, surge isolation protection, noise isolation, etc. can be realized, and the interference of power grid clutter can be effectively isolated, so that the temperature meter is free from external power grid interference when working. The input end of the DC / DC isolated power converter is externally connected to the input capacitor Cin, whose capacitance is ≥47uF and the withstand voltage level is not less than 50V, which can further effectively reduce the input ripple and noise. The output end of the DC / DC isolated power converter is externally connected to the output filter capacitor Cout, whose capacitance is ≥27uF and the withstand voltage level is not less than 35V. It can further effectively reduce the output ripple and noise.

[0247] At the same time, the isolated power supply supports the output power acquisition function, which can intuitively detect the power consumption of the tested thermometer. If the power consumption of the thermometer is significantly different from the rated power consumption, there is a hidden danger of failure, and troubleshooting and maintenance should be carried out in time. Thermometers whose analog output signals deviate from the standard analog curve (the same as the theoretical output curve mentioned above) also have hidden dangers of failure, which may cause a large deviation between the temperature data displayed by the host computer and the actual temperature data, which is directly related to the temperature detection and control of the crystal growth furnace and the quality of crystal growth. Curve calibration or maintenance should be carried out in time.

[0248] The thermometer supports RS485 / 422 communication to transmit temperature, settings and other related data while supporting analog output signals. With the continuous development of digital communication technology, more and more crystal growth furnaces are using serial communication technology to collect relevant information from the thermometer. Therefore, the status of the thermometer's RS485 / 422 communication interface is also very important for temperature acquisition stability during the operation of the crystal growth furnace. This calibration detection device can also test the interface function synchronously.

[0249] Oscilloscope: The oscilloscope measurement probe is electrically connected to the RS485 / 422 communication interface of the thermometer and can be used to detect the RS485 / 422 communication level signal quality of the thermometer.

[0250] It should be noted that the embodiments of this specification can visually observe the communication level quality of the thermometer RS485 / 422 interface by using an oscilloscope, timely discover potential faults, and effectively reduce temperature acquisition anomalies and expansion of fault areas caused by abnormal operation of the interface. At the same time, in order to prevent the electrical interface connected to the device from being damaged by an abnormal thermometer, the RS485 / 422 connection part of the device is designed with a corresponding surge absorption circuit and a common-mode interference suppression circuit, which can effectively extend the service life of the device. For specific designs, see Figure 4 The RS485 / 422 bus anti-interference design schematic diagram is shown.

[0251] RS485 / 422 interface: The thermometer RS485 / 422 interface cable uses a pair of shielded twisted pairs to connect to the common mode inductor T1. Its shield layer is grounded at a single point through R1 and is connected to the common ground of the signal acquisition part. TVS2, TVS3, and TVS4 are surge voltage absorption circuits composed of TVS diodes, which effectively absorb surge voltages between A to ground, B to ground, and AB, and can effectively improve the quality of communication signal waveforms. Then the RS485 / 422 signal is connected to the RS485 isolation transceiver.

[0252] It should be noted that the main function of the surge absorption circuit is to protect the electrical interface connected to it and prevent the surge voltage from damaging the interface. By absorbing the surge current, the surge absorption circuit can prevent the surge voltage from entering the device through the RS485 / 422 connection line, thereby protecting the internal electronic components and avoiding damage caused by excessive voltage, which can extend the service life of the entire device. By suppressing common-mode interference, interference with communication signals can be reduced, thereby improving the stability and reliability of the device and extending the service life of the device.

[0253] It should be noted that the RS485 / 422 interface is an electrical connection for the PLC-related communication interface of the thermometer. It can be used by the PLC to collect relevant data information of the thermometer through RS485 / 422 communication and verify the communication status of the communication interface. If the communication status is not good, such as high packet loss rate, high bit error rate, communication failure, etc., the communication interface has hidden faults and should be promptly troubleshooted and repaired; the flowchart of packet loss rate and bit error rate detection is as follows Figure 5As shown, at the beginning, the initialization process is performed, the temperature information is queried, and it is determined whether the temperature information is returned. If it is determined that the temperature information has been returned, the temperature information is stored, and it is determined whether the returned temperature information has reached a preset number of times. If it is determined that the returned temperature information has reached a preset number of times, the process is terminated; if it is determined that the returned temperature information has not reached the preset number of times, the temperature information is queried again; if it is determined that the temperature information has not been returned, the number of packet losses is recorded, and it is determined whether the packet loss has occurred for three consecutive times. If it is determined that the packet loss has occurred for three consecutive times, the communication is determined to have failed; if it is determined that the packet loss has not occurred for three consecutive times, the temperature information is queried again, and the packet loss rate is calculated.

[0254] Ethernet switch: This part is electrically connected to the thermometer, PLC and industrial PC. It can be used by the PC to collect data information, video information and other content of the thermometer through Ethernet / LAN, and verify the communication status of the communication interface. If the communication status is not good, such as high packet loss rate, communication failure, etc., the communication interface has hidden faults and should be promptly troubleshooted and repaired. Although the Ethernet interface data transmission and RS485 / 422 data transmission use different physical interfaces, the data transmission queries the data in the same internal register. The packet loss rate and bit error rate detection procedures can refer to the above Figure 5 The flowchart of packet loss rate and bit error rate detection is shown.

[0255] Industrial control PC: electrically connected to the RS485 / 422 interface and the Ethernet switch, and sends and queries the calibration command of the thermometer by querying and modifying the internal register data of the thermometer.

[0256] The RS485 port of the thermometer is connected to the RS485 port of the PC for data transmission test. The oscilloscope probe measures the waveforms of the 485A and 485B signals respectively. Figure 6 The RS485 communication test schematic diagram is shown.

[0257] Under normal circumstances, in RS485 / 422 communication: positive level between +2V and +6V indicates logic "1", negative level between -2V and -6V indicates logic "0". When the communication level deviates from the normal level range, the hardware circuit cannot recognize the communication data, increasing the communication bit error rate or even failing to connect and communicate normally, and may burn out the upper communication interface connected to it, causing a larger area of ​​equipment failure. The normal signal waveform diagram is as follows Figure 7 As shown in the figure, waveform 1 is the measured RS485 positive level signal waveform, with a peak-to-peak value of 5.65V and an average value of +3.03V. Waveform 2 is the measured RS485 negative level signal waveform, with a peak-to-peak value of 5.45V and an average value of -3.53V. The differential voltage meets the RS485 standard range.

[0258] It should be noted that the analog acquisition module of the PLC can collect the analog current value output by the thermometer in real time. The analog current value is stored in the corresponding register of the PLC, and compared with the theoretical current value, and the analog offset that needs to be corrected is calculated. The offset setting is sent through the data communication interface to modify the internal register parameters of the thermometer to provide data support.

[0259] Analog output signal calibration:

[0260] The standard slope curve of analog quantity and the common abnormal slope curve are as follows: Figure 8 Schematic diagram of the standard slope curve and common abnormal slope curves shown.

[0261] Send through the RS485 serial interface: 001O = 04, that is, set the analog output of the thermometer to force 4.00mA, the thermometer responds: 001! O10, and the setting is completed. At this time, observe and record the actual output current collected by the PLC analog channel as A1; send through the RS485 serial interface: 001O = 20, that is, set the analog output of the thermometer to force 20.00mA, the thermometer responds: 001! O20, and the setting is completed. At this time, observe and record the actual output current collected by the PLC analog channel as A2.

[0262] After sending the corresponding slope and offset instructions through the RS485 serial interface, repeat the forced output step again, and the actual output current values ​​read are recorded as A1' and A2', which can be infinitely close to 4mA and 20mA. The analog output curve is infinitely close to the ideal output curve.

[0263] Further, for different abnormal curves, see Fig. 9 Schematic diagram of the standard slope curve and common abnormal slope curves shown, where;

[0264] Standard curve: This curve is the standard curve of the analog output of the thermometer;

[0265] Abnormal curve 1 and abnormal curve 2 are the analog outputs that drift downward and upward respectively, but the slope is consistent with the standard slope. At this time, the thermometer is set to output 4mA and 20mA respectively and the actual output current is measured. The actual output current is written into the corresponding register of the thermometer through the software. The internal program of the thermometer can adjust the analog output parameters internally. The analog output curve after the analog calibration operation is closer to the standard curve. The consistency of the thermometer after the calibration operation is high.

[0266] Further, for different abnormal curves, see Fig.10 Schematic diagram of the standard slope curve and common abnormal slope curves shown, where;

[0267] Abnormal curve 3 and abnormal curve 4 are respectively the analog output slopes become smaller and larger. At this time, the thermometer is set to output 0 / 4mA and 20mA respectively and the actual output current is measured. The actual output current is sent through the RS485 serial interface and written into the corresponding register of the thermometer. The internal program of the thermometer can adjust the analog output parameters internally. After the analog calibration operation, the analog output curve is closer to the standard curve. The thermometer has high consistency after the calibration operation.

[0268] It should be noted that the embodiment of this specification designs a comprehensive calibration and detection device that includes an isolated power supply part of the thermometer, a 0-20mA analog quantity acquisition part and curve calibration, RS485 bus communication interface anti-interference, RS485 communication signal waveform detection, RS485 and Ethernet communication packet loss rate detection, etc.; Combined with RS485 communication instructions, the analog output signal of the thermometer is accurately detected and calibrated. Using this device, the thermometer calibrated according to the calibration method ensures that the performance indicators are closer to the idealized curve and improves the linearity and stability of temperature measurement. In order to ensure the accuracy of temperature control measurement in each process of the silicon carbide crystal growth furnace, precise control is achieved to avoid the generation of defects such as crystal inclusions, micropipes, dislocations, etc. caused by abnormal temperature, which seriously affects the growth quality of the crystal and causes economic losses.

[0269] It should be noted that the embodiments of the present specification can comprehensively and efficiently complete the calibration and detection of the crystal growth furnace thermometer, avoiding the use of thermometers with substandard performance indicators in the temperature measurement and control process of silicon carbide crystal growth equipment, reducing the probability of defects such as crystal inclusions, micropipes, dislocations, etc. caused by inaccurate temperature measurement and other problems, and ultimately improving the quality of crystal growth and effectively reducing equipment failure rates.

[0270] It should be noted that the embodiments of this specification can realize fast and efficient detection of all interfaces and functional states of the temperature measuring instrument, a key temperature control component used in the silicon carbide crystal growth furnace, and calibrate it according to the measurement results and the corresponding calibration method.

[0271] It should be noted that the various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

Claims

1. A calibration detection device for a crystal growth furnace temperature measuring instrument, characterized in that: The device comprises: a crystal growth furnace temperature measurement unit, a calibration unit and a detection unit, wherein the crystal growth furnace temperature measurement unit comprises a crystal growth furnace temperature measuring instrument; wherein, The crystal growth furnace temperature measurement unit is used to collect temperature information and output analog signals; The calibration unit calibrates the crystal growth furnace temperature measurement unit based on the analog output signal, so that the crystal growth furnace temperature measurement unit obtains accurate temperature information; The detection unit performs detection based on the communication status of the communication interface corresponding to the temperature information to obtain the stability of temperature collection during the operation of the crystal growth furnace temperature measurement unit.

2. The device according to claim 1, characterized in that The device also includes a programmable logic controller PLC, and the communication interface includes a serial interface; The PLC acquires the temperature information through the serial interface to obtain a first communication state of the serial interface; The detection unit is specifically used for: Detection is performed based on the first communication state to obtain the stability of temperature collection during the operation of the crystal growth furnace temperature measurement unit.

3. The device according to claim 2, characterized in that The serial interface is an RS485 / 422 interface, and the detection unit is specifically used for: When the crystal growth furnace temperature measurement unit collects the temperature information, querying the temperature information through the RS485 / 422 interface; Determine whether the RS485 / 422 interface returns temperature information; If not, record the number of packet losses, and determine the packet loss rate of the RS485 / 422 interface based on the number of packet losses; If yes, store the temperature information, determine an abnormal temperature based on the temperature information, and determine a bit error rate of the RS485 / 422 interface based on the abnormal temperature; Based on the packet loss rate of the RS485 / 422 interface and the bit error rate of the RS485 / 422 interface, the RS485 / 422 interface is judged to obtain the stability of temperature collection during the operation of the crystal growth furnace temperature measurement unit.

4. The device according to claim 1, characterized in that The device also includes an Ethernet switch, and the communication interface includes an Ethernet interface; The Ethernet switch acquires the temperature information through the Ethernet interface to obtain a second communication state of the Ethernet interface; The detection unit is specifically used for: Detection is performed based on the second communication state to obtain the stability of temperature collection during the operation of the crystal growth furnace temperature measurement unit.

5. The device according to claim 4, characterized in that The detection unit is specifically used for: When the crystal growth furnace temperature measurement unit collects the temperature information, querying the temperature information through the Ethernet interface; Determining whether the Ethernet interface returns temperature information; If not, record the number of packet losses, and determine the packet loss rate of the Ethernet interface based on the number of packet losses; If yes, store the temperature information, determine an abnormal temperature based on the temperature information, and determine a bit error rate of the Ethernet interface based on the abnormal temperature; Based on the packet loss rate of the Ethernet interface and the bit error rate of the Ethernet interface, the Ethernet interface is judged to obtain the stability of temperature collection during the operation of the crystal growth furnace temperature measurement unit.

6. The device according to claim 1, characterized in that The device also includes a PLC; The PLC is used to collect the analog output signal output by the temperature measuring unit of the crystal growth furnace in real time and store it in the corresponding register; The calibration unit is specifically used for: Based on the analog output signal stored in the PLC and a preset theoretical output curve, the crystal growth furnace temperature measurement unit is calibrated so that the crystal growth furnace temperature measurement unit obtains accurate temperature information. The theoretical output curve is determined by multiple ideal output signals.

7. The device according to claim 6, characterized in that The analog output signal includes analog current value and analog temperature output data; the theoretical output signal includes theoretical current value and theoretical temperature output data; the analog output signal is provided with a plurality of; The calibration unit is specifically used for: Determine a current output curve based on the analog output signal stored in the PLC; Based on the theoretical output curve, determining the analog offset that needs to be corrected for the current output curve; The analog offset is sent to the crystal growth furnace temperature measurement unit so that the crystal growth furnace temperature measurement unit is calibrated based on the analog offset.

8. The device according to claim 1, characterized in that The device also includes a working condition PC; the working condition PC is connected to the communication interface; The working condition PC sends and queries the calibration command of the crystal growth furnace temperature measuring unit by querying and modifying the internal register data of the crystal growth furnace temperature measuring unit.

9. The device according to claim 2, characterized in that The device also includes an oscilloscope; The oscilloscope is used to electrically connect the measuring probe to the serial interface of the communication interface and detect the communication level quality of the serial interface, wherein the communication level quality of the serial interface is used to indicate the state of the serial interface.

10. The device according to claim 2, characterized in that The serial interface has a built-in surge absorption circuit and a common mode interference suppression circuit.

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