Double-loop control method and system for medium-frequency induction heating of semiconductor liquid source

Abstract

The invention relates to a double-loop control method and system for medium-frequency induction heating of a semiconductor liquid source, and belongs to the technical field of semiconductor manufacturing configuration equipment. The method comprises the steps that the medium-frequency induction electric frequency is obtained, the resonant frequency is synchronously adjusted, and a liquid source heating control basis is provided; constructing a temperature-pressure double-loop feedback curve, dynamically adjusting the inversion output power through a proportional-integral algorithm, and controlling the amplitude and distribution of the medium-frequency induction heating current; through a differential serial communication protocol, the signals are transmitted to the flexible heating coil through a twisted-pair shielded wire and a differential signal interface, and the liquid source is heated by the induction eddy current; and controlling the temperature of the induced eddy current heat source based on a fanless cooling scheme, adjusting the cooling intensity by associating the medium-frequency induced electric frequency, and executing power limitation when the load impedance is abnormal based on built-in safety interlocking logic when the liquid source temperature is monitored to deviate from a preset safety cooling temperature interval.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of semiconductor manufacturing configuration equipment, and particularly relates to a semiconductor liquid source medium-frequency induction heating double-loop control method and system. BACKGROUND

[0002] In the process of semiconductor manufacturing, thin film deposition and chemical vapor transport, the liquid precursor or reaction liquid source usually needs to be heated under controlled conditions to ensure its stable evaporation or transport performance. The existing liquid source heating methods mostly use resistance heating, external heating band or hot plate heating, etc. The above-mentioned schemes have relatively simple structure, but in actual application, there are problems such as low heating efficiency, large thermal inertia, local overheating and insufficient electromagnetic compatibility, which are difficult to meet the process requirements of high precision, fast response and high reliability.

[0003] In recent years, medium-frequency induction heating has been gradually introduced into the field of liquid source heating due to its non-contact heating, fast response speed and high energy utilization rate. However, the existing medium-frequency induction heating systems mostly focus on power output or single temperature control, and lack comprehensive consideration of the changes of liquid source pressure, load impedance and the coupling relationship of multiple physical quantities in the heating process. When the state of the liquid source changes, it is easy to cause unstable heating power, and even safety hazards such as resonance deviation, over-temperature or over-pressure.

[0004] In addition, the existing induction heating systems mostly use fixed frequency or rough frequency modulation in inverter control, which is difficult to always work at the best resonance point under the condition of dynamic change of load parameters, thereby affecting the energy transmission efficiency. At the same time, in a complex electromagnetic environment, the heating control signal and power signal are easy to be disturbed by electromagnetic interference, resulting in a decrease in control accuracy and even system malfunction.

[0005] In terms of heat dissipation and safety, traditional liquid source heating equipment mostly relies on fans or forced air cooling for heat dissipation, which not only increases mechanical noise and maintenance cost, but also has the problems of dust introduction and insufficient reliability. For semiconductor application scenarios with high cleanliness requirements, the above-mentioned heat dissipation methods are difficult to operate stably for a long time. In addition, the safety protection in the existing system is mostly simple over-temperature or over-current protection, which lacks a safety interlocking mechanism based on the cooperative judgment of multiple parameters, and is difficult to effectively intervene before an abnormality occurs.

[0006] Therefore, how to realize the cooperative control of frequency, power, temperature and pressure in the process of medium-frequency induction heating of the liquid source while ensuring electromagnetic compatibility and system safety, and improve the stability and reliability of the system, is still a technical problem to be solved in the field. SUMMARY

[0007] To solve the above problems in the prior art, the present application provides a semiconductor liquid source medium-frequency induction heating double-loop control method.

[0008] The object of the application can be achieved by the following technical solutions: S1: Obtain the intermediate frequency induction electric frequency, control the frequency range of the output intermediate frequency alternating current based on the full-bridge insulated inverter topology architecture, and synchronize the resonant frequency through the phase-locked loop to make the inverter output frequency always track the load resonance point, thereby providing the liquid source heating control basis; S2: Construct a temperature-pressure double-loop feedback curve to collect the liquid source bottle wall temperature and pressure signals in real time, compare them with the corresponding target set values, generate temperature deviation signals and pressure deviation signals, dynamically adjust the inverter output power through the proportional integral algorithm, control the amplitude and distribution of the intermediate frequency induction heating current, and generate a directional eddy current heating signal; S3: According to the backflow path formed by the directional eddy current heating signal induction current, a closed electromagnetic shielding loop is constructed, and the signal is transmitted to the flexible heating coil through the differential serial communication protocol via the twisted shielded wire and the differential signal interface, and the induction eddy current heats the liquid source; S4: Control the induction eddy current heat source temperature based on the fanless cooling scheme, and associate the intermediate frequency induction electric frequency to adjust the cooling intensity. When it is monitored that the liquid source temperature deviates from the preset safe cooling temperature interval, execute power limitation when the load impedance is abnormal based on the built-in safety interlocking logic.

[0009] Specifically, the method for obtaining the intermediate frequency induction electric frequency is: equivalent impedance modeling of the intermediate frequency induction heating load, calculation of the resonant frequency interval of the load system, execution of intermediate frequency sweep detection, collection of inverter output voltage and current signals to calculate the phase difference of voltage and current, and determination of the actual resonant frequency of the load according to the frequency point with the minimum phase difference or the maximum current amplitude. The frequency is taken as the initial output frequency to obtain the frequency induction electric frequency.

[0010] Specifically, the method for controlling the frequency range of the output intermediate frequency alternating current based on the full-bridge insulated inverter topology architecture is: according to the heating power demand of the intermediate frequency induction heating load, preset the target frequency interval of the inverter output intermediate frequency alternating current, within the target frequency interval, frequency modulation is performed on the drive signal of the full-bridge inverter power switch, the working frequency of the inverter output alternating current is limited to not exceed the upper and lower limits of the target frequency interval, and the target frequency interval is taken as the frequency constraint condition of the phase-locked loop. When the load resonant frequency changes, the output frequency of the phase-locked loop is always limited within the target frequency interval, thereby controlling the frequency range of the output intermediate frequency alternating current.

[0011] Specifically, the method for synchronously adjusting the resonant frequency by the phase-locked loop comprises the following steps: calculating a phase difference according to a medium-frequency alternating voltage signal and a medium-frequency alternating current signal output by the full-bridge insulation inverter topology architecture, taking the phase difference as a phase error signal of the phase-locked loop, and dynamically adjusting the resonant frequency of the medium-frequency alternating current output by the inverter through filtering and feedback of the phase-locked loop on the phase error signal.

[0012] Specifically, the method for constructing the temperature-pressure double-loop feedback curve comprises the following steps: setting a target temperature curve and a target pressure curve according to the characteristics of the semiconductor liquid source and process requirements, filtering and time-aligning a liquid source bottle wall temperature signal and an internal pressure signal, respectively mapping to corresponding target position detection control deviation values, the control deviation values comprising a temperature control deviation and a pressure control deviation, constructing a temperature-pressure double-loop feedback curve, and when the temperature control deviation and the pressure control deviation exist at the same time, coordinating the two control amounts according to a preset priority rule to obtain feedback data of the inverter output power.

[0013] Specifically, the method for dynamically adjusting the inverter output power by the proportional-integral algorithm comprises the following steps: comparing the liquid source bottle wall temperature and pressure signals with target set temperature and pressure values to obtain temperature deviation and pressure deviation values, weighting and superimposing the temperature deviation and the pressure deviation values according to preset weight coefficients to obtain a power control comprehensive error signal, inputting the power control comprehensive error signal into a proportional-integral controller, and limiting or resisting integral saturation processing of an integral term to adjust the inverter output power.

[0014] Specifically, the method for generating the directional eddy current heating signal comprises the following steps: adjusting the amplitude of a medium-frequency induction heating current output by the full-bridge insulation inverter topology according to the inverter output power adjustment instruction output by the proportional-integral controller, and under the condition that the frequency of the medium-frequency induction heating current is in a load resonant tracking state, controlling the current phase and on-off timing of the induction heating coil to generate a corresponding directional eddy current heating signal.

[0015] Specifically, the process of transmitting the directional eddy current heating signal by the differential serial communication protocol comprises the following steps: differentially encoding the directional eddy current heating signal, transmitting the same signal in the form of a pair of electrical signals with equal amplitude and opposite phase, and packaging power adjustment parameters in the directional eddy current heating signal according to a frame structure to transmit the directional eddy current heating signal in a strong electromagnetic interference environment.

[0016] Specifically, the fanless cooling scheme comprises a gas cabinet self-circulation gas cooling system and a Peltier solid-state active refrigeration heat dissipation system. The gas cabinet self-circulation gas cooling system: the built-in spiral flow guide channel enables the gas in the gas cabinet to generate natural convection after being heated and flow along a preset path, and the density difference formed by the temperature gradient in the gas cabinet drives the gas to flow self-circulation, and the heat is conducted from the high-temperature area to the gas cabinet wall or the heat dissipation structure, forming a gas cabinet gas production-heat dissipation cavity-downstream self-circulation loop; The Peltier solid-state active refrigeration heat dissipation system: control current is applied to control the thermal coupling between the cold end and the heat generating end, actively extract the heat generated by the heat generating end, and thermally connect with the heat dissipation structure, release the extracted heat to the external environment, and complete the active temperature control and heat dissipation.

[0017] Specifically, the method for setting the safe cooling temperature range is: according to the allowable working temperature range of the liquid source bottle, the corresponding lowest safe temperature threshold and the highest safe temperature threshold are determined, and the lowest safe temperature threshold and the highest safe temperature threshold are corrected in combination with the heat dissipation capacity of the gas cabinet self-circulation gas cooling system and the Peltier solid-state active refrigeration heat dissipation system under the fanless cooling scheme, and the safe cooling temperature range is set.

[0018] Specifically, the method for limiting the execution power by the built-in safety interlocking logic is: according to the impedance state of the intermediate frequency induction heating load and the working state of the cooling system, it is judged whether there is over-temperature or abnormal load impedance, when any parameter is detected to exceed the corresponding safety threshold, the safety interlocking control is triggered, and the power limitation is executed according to the abnormal level, the safety interlocking control includes: when a slight abnormality is detected, the inverter output power limitation or frequency offset control is executed; when a moderate abnormality is detected, the Peltier solid-state active refrigeration heat dissipation system is triggered and the output of the directional eddy current heating signal is limited; when a serious abnormality is detected, the full-bridge insulated inverter topology is immediately turned off and the system is kept in a locked state until the abnormality is resolved or the system is reset. And keep interlocking state before abnormal state is removed.

[0019] Specifically, a dual-loop control system for semiconductor liquid source intermediate frequency induction heating includes: Intermediate frequency resonance control module: obtain the intermediate frequency induction electric frequency, control the frequency range of the output intermediate frequency alternating current based on the full-bridge insulated inverter topology architecture, and synchronize the resonance frequency through the phase-locked loop to make the inverter output frequency always track the load resonance point, and provide the basis for liquid source heating control; Temperature and pressure dual-loop control module: build a temperature-pressure dual-loop feedback curve to collect liquid source bottle wall temperature and pressure signals in real time, and compare them with corresponding target set values to generate temperature deviation signals and pressure deviation signals, and dynamically adjust the inverter output power through proportional integral algorithm to control the amplitude and distribution of the intermediate frequency induction heating current, and generate a directional eddy current heating signal; Differential shield transmission module: according to the backflow path formed by the induced current of the directional eddy current heating signal, a closed electromagnetic shield loop is constructed, and the signal is transmitted to the flexible heating coil through the differential serial communication protocol via the twisted shield line and the differential signal interface, and the liquid source is heated by the induced eddy current; Cooling interlock limiting module: based on the fanless cooling scheme, the temperature of the inductive eddy current heat source is controlled, and the cooling intensity is adjusted in association with the intermediate frequency induction electric frequency; when the temperature of the liquid source deviates from the preset safe cooling temperature interval is monitored, the power limitation is executed based on the built-in safety interlock logic when the load impedance is abnormal.

[0020] The beneficial effects of the present application are: The present application provides a kind of semiconductor liquid source intermediate frequency induction heating double-loop control method, by the frequency, power and safety control of intermediate frequency induction heating system are cooperated design, effectively improve the stability, response speed and operation safety of liquid source heating process.

[0021] By acquiring the intermediate frequency induction electric frequency, and based on the full-bridge insulated inverter topology combined with phase-locked loop synchronous regulation resonance frequency, the inverter output frequency can track the load resonance point in real time, and under the condition of liquid source state and load parameter change, energy transmission efficiency can still be kept stable, energy loss and system instability risk caused by resonance deviation are reduced, to provide reliable frequency control basis for liquid source heating.

[0022] Temperature-pressure double-loop feedback control mechanism is constructed, liquid source bottle wall temperature and internal pressure signal are introduced into the same control framework, and proportional integral algorithm is used to dynamically adjust inverter output power, to realize fine control of intermediate frequency induction heating current amplitude and distribution, so that directional eddy current heating effect is formed, local overheating phenomenon is reduced, and liquid source heating uniformity and control precision are improved.

[0023] The directional eddy current heating signal is packaged with ceramic and shielded with double-layer copper, and is transmitted to the flexible heating coil through the differential serial communication protocol via the twisted shield line, to effectively suppress electromagnetic interference and improve signal integrity and reliability of the system in complex electromagnetic environment.

[0024] In addition, the present application combines fanless cooling scheme and built-in safety interlock logic to regulate the temperature of the inductive eddy current heat source, and executes power limitation or protection control under abnormal working condition, to reduce system operation risk, improve overall safety and long-term operation reliability, and is suitable for semiconductor liquid source heating scenarios with high cleanliness and stability requirements. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to facilitate the understanding of those skilled in the art, the present application is further described below with reference to the drawings.

[0026] Figure 1A schematic diagram of a framework of a semiconductor liquid source intermediate frequency induction heating double-loop control method.

[0027] Figure 2 A schematic diagram of an induction heating system of a semiconductor liquid source intermediate frequency induction heating double-loop control system.

[0028] Figure 3 A double-loop feedback control system block diagram of a semiconductor liquid source intermediate frequency induction heating double-loop control system. DETAILED DESCRIPTION

[0029] In order to further illustrate the technical means and effects adopted by the present application to achieve the predetermined inventive purposes, the specific embodiments, structures, features and effects according to the present application are described in detail below in combination with the drawings and preferred embodiments.

[0030] Please refer to Figure 1 A semiconductor liquid source intermediate frequency induction heating double-loop control method: S1: Obtain the intermediate frequency induction electric frequency, control the frequency range of the output intermediate frequency alternating current based on the full-bridge insulation inverter topology architecture, and adjust the resonant frequency through the phase-locked loop synchronization, so that the inverter output frequency always tracks the load resonance point, providing the basis for liquid source heating control; S2: Construct a temperature-pressure double-loop feedback curve to collect the liquid source bottle wall temperature and pressure signals in real time, and compare them with the corresponding target set value to generate a temperature deviation signal and a pressure deviation signal, and dynamically adjust the inverter output power through a proportional integral algorithm to control the amplitude and distribution of the intermediate frequency induction heating current, and generate a directional eddy current heating signal; S3: According to the backflow path formed by the directional eddy current heating signal induction current, a closed electromagnetic shielding loop is constructed, and transmitted to the flexible heating coil through the twisted shielded wire and differential signal interface through the differential serial communication protocol, and the induction eddy current heats the liquid source; S4: Control the induction eddy current heat source temperature based on the fanless cooling scheme, and associate the intermediate frequency induction electric frequency to adjust the cooling intensity, and when the liquid source temperature deviates from the preset safe cooling temperature interval is monitored, the power limit is executed based on the built-in safety interlocking logic when the load impedance is abnormal.

[0031] In this embodiment, the method for obtaining the intermediate frequency induction electric frequency is: equivalent impedance modeling of the intermediate frequency induction heating load, calculating the resonant frequency interval of the load system, performing intermediate frequency sweep detection, collecting inverter output voltage and current signals to calculate the phase difference of voltage and current, and determining the actual resonant frequency of the load according to the frequency point with the minimum phase difference or the maximum current amplitude, taking the frequency as the initial output frequency, and obtaining the frequency induction electric frequency.

[0032] In the embodiment, the method for controlling the frequency range of the output intermediate frequency alternating current in the full-bridge isolated inverter topology architecture is as follows: a target frequency interval of the inverter output intermediate frequency alternating current is preset according to the heating power requirement of the intermediate frequency induction heating load, the driving signal of the full-bridge inverter power switch is frequency modulated within the target frequency interval, the working frequency of the inverter output alternating current is limited to not exceed the upper and lower limits of the target frequency interval, the target frequency interval is taken as the frequency constraint condition of the phase-locked loop, and the frequency of the phase-locked loop output is always limited within the target frequency interval when the load resonant frequency changes, so as to control the frequency range of the output intermediate frequency alternating current.

[0033] In the embodiment, the method for synchronously adjusting the resonant frequency by the phase-locked loop is as follows: the phase difference is calculated according to the intermediate frequency alternating voltage signal and the intermediate frequency alternating current signal output by the full-bridge isolated inverter topology architecture, the phase difference is taken as the phase error signal of the phase-locked loop, and the phase-locked loop is used to filter and feed back the phase error signal, so as to dynamically adjust the resonant frequency of the inverter output intermediate frequency alternating current.

[0034] In the embodiment, the method for constructing the temperature-pressure double-loop feedback curve is as follows: the target temperature curve and the target pressure curve are respectively set according to the characteristics of the semiconductor liquid source and the process requirement, the liquid source bottle wall temperature signal and the internal pressure signal are time-aligned after being filtered, and are respectively mapped to the corresponding target position to detect the control deviation value, the control deviation value includes the temperature control deviation and the pressure control deviation, the temperature-pressure double-loop feedback curve is constructed, and when the temperature control deviation and the pressure control deviation exist at the same time, the two control amounts are coordinated according to the preset priority rule to obtain the feedback data of the inverter output power.

[0035] In the embodiment, as shown in the system, Figure 2 the power controller is taken as the energy core, the 20-50 kHz intermediate frequency alternating current is output to the induction coil in the flexible heating blanket, the alternating magnetic field is generated by the coil to induce eddy current in the steel bottle wall to realize the directional heating of the liquid-gas interface, the temperature and pressure signals are collected by the double-loop feedback system to dynamically adjust the power supply parameters, the fanless cooling module provides long-term heat dissipation for the power device to ensure 24-hour stable operation.

[0036] The power controller adopts the full-bridge IGBT inverter topology structure, the frequency range of the output intermediate frequency alternating current is 20-50 kHz, the resonant frequency is automatically tracked by the phase-locked loop (PLL) technology, the system always works in the best energy transmission state when the load impedance changes, the safety interlocking logic of the built-in over-temperature, over-voltage, over-current and dry burning protection has an abnormal signal response time of ≤0.1 ms.

[0037] As shown in the double-loop feedback control system, Figure 3 the embedded control module with the MCU as the core is adopted: Temperature feedback monitoring unit: Array PT100 platinum resistance sensor group is adopted, the main sensor is embedded in the low interference area of the heating blanket, the minimum distance between the sensor and the coil is ≥20 mm, and the accurate collection of the steel cylinder wall temperature is realized.

[0038] Pressure feedback collection unit: The pressure sensor is arranged inside the steel cylinder gas outlet flange (5-10 mm away from the outlet end face), coaxial with the flow channel axis; anti-condensation packaging is adopted, the temperature resistance range is-20℃~120℃, the measurement range is 0-2.5MPa, the accuracy is ±0.25% FS, it is fixed by thread sealing to avoid flow field disturbance.

[0039] Collaborative control strategy: built-in PID control algorithm, signal sampling frequency ≥1kHz; adopt the priority strategy of "temperature safety first, pressure stability first": the response time of temperature overrun signal (≥80℃±5℃) is ≤0.1ms, and the power is immediately cut off; when the temperature is safe, the pressure deviation is taken as the core, and the power output (step size ≤5W) is adjusted to maintain the pressure accuracy ±0.02MPa.

[0040] Fanless solid-state cooling module and power controller sealed aluminum shell integrated design, providing two replaceable solutions: Solution one: air tank self-circulation gas cooling system: the power device is attached to the aluminum nitride (AlN) ceramic substrate (thermal conductivity ≥170W / (m·K), thickness 2-3mm), the substrate is coupled with a copper heat dissipation cavity (built-in spiral flow channel: inner diameter 8-12mm, pitch 15-20mm); the heat dissipation cavity is connected with the steel cylinder gas tank outlet branch through a high-temperature resistant hose, forming a "air tank gas production-heat dissipation cavity-downstream" self-circulation loop, the interface adopts V-ring sealing, and the protection level is IP66.

[0041] Solution two: Peltier solid-state active refrigeration cooling system: the power device is attached to a multi-stage series Peltier module (refrigeration power 50-150W, temperature difference ≥60℃) through a heat-conducting pad, the hot end of the module is coupled with an aluminum heat sink array (thickness 1.5-2mm, spacing 8-10mm) through an AlN substrate; an NTC temperature sensor is configured to realize temperature linkage control, the module is packaged with potting glue, and the mechanical life is ≥50000 hours.

[0042] The installation interfaces of the two solutions are standardized designed, the shell is formed by die casting process (flatness ≤0.02mm), the protection level is IP66, and different scene requirements are adapted.

[0043] The working process is as follows: Installation and adaptation: fix the flexible heating blanket on the bottom of the steel cylinder through magic tape / buckle, and assemble the power controller according to the fanless cooling solution; Energy output: the power controller outputs 20-50 kHz intermediate frequency alternating current to the coil, the coil generates an alternating magnetic field, which induces eddy current in the steel cylinder wall and generates Joule heat, heating the liquid-gas interface to achieve vaporization; Double-loop regulation: temperature sensor collects the temperature of the steel cylinder wall, and pressure sensor collects the outlet pressure; when the temperature exceeds the limit, the power is immediately cut off, and when the temperature is safe, the power is adjusted through the PID algorithm to maintain stable pressure; Long-term cooling: the gas tank self-circulation scheme uses vaporized gas to dissipate heat, or the Peltier scheme actively cools to ensure that the temperature of the power device is stable at 25-60°C.

[0044] The specific implementation process is as follows: Taking the vaporization of a typical steel cylinder liquid source as the application object, a flexible induction heating coil is used to generate eddy current to achieve directional heating. The temperature and pressure signals are fed into the MCU through the double-loop feedback module, and the PID algorithm is executed to adjust the inverter output power, so that the vaporization process runs in an efficient, safe and controllable state.

[0045] The internal structure of the flexible induction heating coil is formed by one-body molding with silica gel, the heating coil is embedded in the middle layer, and the elastic structure ensures that it does not deform or lift when it is attached to steel cylinders with different curvatures. The temperature sensor is arranged in a low magnetic field area and is equipped with ceramic + copper shielding to suppress electromagnetic interference.

[0046] The power controller uses IGBT full-bridge inverter, and automatically adjusts the working frequency through PLL to match the equivalent resonance point of the coil, improves the efficiency and reduces the heat loss of the components. The embedded safety interlock can judge the abnormality such as dry burning, over temperature and over current in real time.

[0047] The closed electromagnetic shielding loop is arranged inside the intermediate frequency induction heating control unit in the form of a ceramic package, an inner copper shielding layer and an outer copper shielding layer are sequentially arranged outside the ceramic package, forming a double-layer shielding structure. The inner copper shielding layer mainly covers the key high-frequency nodes of the driving circuit to weaken the electromagnetic radiation of the intermediate frequency induction heating signal in the near field; the outer copper shielding layer mainly covers the whole ceramic package to suppress the leakage of electromagnetic energy to the outside space.

[0048] The inner copper shielding layer and the outer copper shielding layer are connected to the system shielding ground through a pre-set conductive structure, which includes a conductive via, a metal pin or a shielding connecting piece, so that a low-impedance connection path is formed between the double-layer copper shielding layer and the system reference ground, and the induced current generated by the intermediate frequency induction heating signal can be returned to the system shielding ground along the shielding layer, thereby forming a closed electromagnetic shielding loop.

[0049] The fanless solid-state cooling module can select a gas self-circulation or a Peltier scheme according to system heat, realize a high-thermal-conductivity path through an AlN substrate, and make the system have the ability of long-term continuous operation.

[0050] In the embodiment, the method for dynamically adjusting the inverter output power by the proportional-integral algorithm is: comparing the liquid source bottle wall temperature and pressure signals with the target set temperature and pressure values, obtaining temperature deviation and pressure deviation values, and weighting and superimposing them according to preset weight coefficients to obtain a power control comprehensive error signal, which is input to the proportional-integral controller, the integral term is limited or anti-integral saturation processing, and the inverter output power is adjusted.

[0051] In the embodiment, the method for generating the directional eddy current heating signal is: adjusting the amplitude of the medium-frequency induction heating current output by the full-bridge insulated inverter topology according to the inverter output power adjustment instruction output by the proportional-integral controller, and under the condition that the frequency of the medium-frequency induction heating current is in the load resonance tracking state, controlling the current phase and on-off timing of the induction heating coil to generate the corresponding directional eddy current heating signal.

[0052] In the embodiment, the process of transmitting the directional eddy current heating signal by the differential serial communication protocol is: differentially encoding the directional eddy current heating signal, transmitting the same signal in the form of a pair of electrical signals with equal amplitude and opposite phase, and packaging the power adjustment parameters in the directional eddy current heating signal according to the frame structure to transmit the directional eddy current heating signal in a strong electromagnetic interference environment.

[0053] In the embodiment, the fanless cooling scheme includes a gas cabinet self-circulation gas cooling system and a Peltier solid-state active refrigeration heat dissipation system. The gas cabinet self-circulation gas cooling system: a spiral flow guide channel is built-in, so that the gas in the gas cabinet naturally convects and circulates along the preset path after being heated, and the density difference formed by the temperature gradient in the gas cabinet drives the gas to circulate, so that the heat is conducted from the high-temperature area to the gas cabinet wall or the heat dissipation structure, forming a gas cabinet gas production-heat dissipation cavity-downstream self-circulation loop. The Peltier solid-state active refrigeration heat dissipation system: a control current is applied to control the thermal coupling between the cold end and the heat-generating end, actively extract the heat generated by the heat-generating end, and thermally connect with the heat dissipation structure to release the extracted heat to the external environment, and complete the active temperature control and heat dissipation.

[0054] In the embodiment, the method for setting the safe cooling temperature interval is: determining the corresponding minimum safe temperature threshold and maximum safe temperature threshold according to the allowable working temperature range of the liquid source bottle body, and correcting the minimum safe temperature threshold and maximum safe temperature threshold according to the heat dissipation capacity of the gas cabinet self-circulation gas cooling system and the Peltier solid-state active refrigeration heat dissipation system under the fanless cooling scheme, and setting the safe cooling temperature interval.

[0055] In this embodiment, the method for limiting the execution power by the built-in safety interlock logic is to determine whether there is over-temperature or abnormal load impedance according to the impedance state of the intermediate frequency induction heating load and the working state of the cooling system, and to trigger the safety interlock control when any parameter is detected to exceed the corresponding safety threshold, and to execute power limitation according to the abnormality level, the safety interlock control including: when a slight abnormality is detected, executing the inverter output power limitation or frequency offset control; when a moderate abnormality is detected, triggering the Peltier solid-state active refrigeration cooling system and limiting the output of the directional eddy current heating signal; when a serious abnormality is detected, immediately shutting down the full-bridge insulated inverter topology and keeping the system in a locked state until the abnormality is resolved or the system is reset. And the interlock state is kept before the abnormal state is resolved.

[0056] The embodiment of the present application also provides a semiconductor liquid source intermediate frequency induction heating double-loop control system, which specifically comprises: An intermediate frequency resonance control module: obtaining an intermediate frequency induction electric frequency, controlling the frequency range of the output intermediate frequency alternating current based on a full-bridge insulated inverter topology architecture, and synchronously adjusting the resonance frequency through a phase-locked loop to make the inverter output frequency always track the load resonance point, thereby providing a liquid source heating control basis; A temperature-pressure double-loop control module: constructing a temperature-pressure double-loop feedback curve to collect the liquid source bottle wall temperature and pressure signals in real time, comparing them with the corresponding target set values, generating temperature deviation signals and pressure deviation signals, dynamically adjusting the inverter output power through a proportional integral algorithm, controlling the amplitude and distribution of the intermediate frequency induction heating current, and generating a directional eddy current heating signal; A differential shielding transmission module: constructing a closed electromagnetic shielding loop according to the backflow path formed by the directional eddy current heating signal induction current, and transmitting the signal to the flexible heating coil through a differential serial communication protocol via a twisted pair shielded line and a differential signal interface to induce the eddy current to heat the liquid source; A cooling interlock limitation module: controlling the induction eddy current heat source temperature based on a fanless cooling scheme, and adjusting the cooling intensity in association with the intermediate frequency induction electric frequency, and executing power limitation when a load impedance abnormality occurs based on the built-in safety interlock logic when the liquid source temperature is detected to deviate from the preset safe cooling temperature interval.

[0057] The above is only a preferred embodiment of the present application, and does not limit the present application in any form. Although the present application has been disclosed as above with a preferred embodiment, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to the above disclosed technical content without departing from the scope of the technical solution of the present application to obtain equivalent embodiments with equivalent changes. Any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present application shall still fall within the scope of the technical solution of the present application.

Claims

1. A dual-loop control method for semiconductor liquid source medium-frequency induction heating, characterized in that, include: S1: Obtain the intermediate frequency induced current frequency, control the frequency range of the output intermediate frequency AC power based on the full-bridge insulated inverter topology, and synchronously adjust the resonant frequency through the phase-locked loop so that the inverter output frequency always tracks the load resonant point, providing the basis for liquid source heating control; S2: Construct a temperature-pressure dual-loop feedback curve to collect the temperature and pressure signals of the liquid source bottle wall in real time, and compare them with the corresponding target set values ​​to generate temperature deviation signals and pressure deviation signals. Dynamically adjust the inverter output power through the proportional-integral algorithm to control the amplitude and distribution of the medium-frequency induction heating current and generate directional eddy current heating signals. S3: Based on the return path formed by the induced current of the directional eddy current heating signal, a closed electromagnetic shielding circuit is constructed, and transmitted to the flexible heating coil through a twisted-pair shielded wire and a differential signal interface via a differential serial communication protocol to induce the eddy current heating liquid source. S4: Based on the fanless cooling scheme, the temperature of the induction eddy current heat source is controlled, and the cooling intensity is adjusted by linking the intermediate frequency induction frequency. When the liquid source temperature is detected to deviate from the preset safe cooling temperature range, the power limit is executed based on the built-in safety interlock logic when the load impedance is abnormal.

2. The method according to claim 1, characterized in that, The method for obtaining the intermediate frequency induced electric frequency is as follows: the equivalent impedance model of the intermediate frequency induction heating load is performed, the resonant frequency range of the load system is calculated, intermediate frequency sweep detection is performed, the inverter output voltage and current signals are collected to calculate the phase difference between the voltage and current, and the actual resonant frequency of the load is determined according to the frequency point with the smallest phase difference or the largest current amplitude. This frequency is used as the initial output frequency to obtain the intermediate frequency induced electric frequency.

3. The method according to claim 1, characterized in that, The method for controlling the frequency range of the output intermediate frequency AC power in the full-bridge insulated inverter topology is as follows: a target frequency range for the inverter output intermediate frequency AC power is preset according to the heating power requirement of the intermediate frequency induction heating load. Within the target frequency range, the drive signal of the full-bridge inverter power switch is frequency modulated to limit the operating frequency of the inverter output AC power to not exceed the upper and lower limits of the target frequency range. The target frequency range is used as the frequency constraint condition of the phase-locked loop. When the load resonant frequency changes, the output frequency of the phase-locked loop is always limited to the target frequency range, thereby controlling the frequency range of the output intermediate frequency AC power.

4. The method according to claim 1, characterized in that, The method for synchronously adjusting the resonant frequency of the phase-locked loop is as follows: calculate the phase difference between the intermediate frequency AC voltage signal and the intermediate frequency AC current signal output by the full-bridge insulated inverter topology, use the phase difference as the phase error signal of the phase-locked loop, and filter and feed back the phase error signal through the phase-locked loop to dynamically adjust the resonant frequency of the intermediate frequency AC power output by the inverter.

5. The method according to claim 2, characterized in that, The method for constructing the temperature-pressure dual-loop feedback curve is as follows: Target temperature and target pressure curves are set according to the characteristics and process requirements of the semiconductor liquid source. The temperature signal of the liquid source bottle wall and the internal pressure signal are filtered and time-aligned, and mapped to the corresponding target positions to detect control deviation values. The control deviation values ​​include temperature control deviation and pressure control deviation. A temperature-pressure dual-loop feedback curve is constructed. When both temperature control deviation and pressure control deviation exist simultaneously, the two control quantities are coordinated according to a preset priority rule to obtain feedback data of the inverter output power.

6. The method according to claim 5, characterized in that, The method of dynamically adjusting the inverter output power using the proportional-integral algorithm is as follows: the temperature and pressure signals of the liquid source bottle wall are compared with the target set temperature and pressure values ​​to obtain the temperature deviation and pressure deviation values, and then weighted and superimposed according to the preset weight coefficients to obtain the power control comprehensive error signal, which is input to the proportional-integral controller to limit the integral term or perform anti-integral saturation processing to adjust the inverter output power.

7. The method according to claim 4, characterized in that, The method for generating the directional eddy current heating signal is as follows: according to the inverter output power adjustment command output by the proportional-integral controller, the amplitude of the intermediate frequency induction heating current output by the full-bridge insulated inverter topology is adjusted, and under the condition that the frequency of the intermediate frequency induction heating current is in the load resonance tracking state, the current phase and on / off timing of the induction heating coil are controlled to generate the corresponding directional eddy current heating signal.

8. The method according to claim 2, characterized in that, The process of transmitting directional eddy current heating signals using the differential serial communication protocol is as follows: the directional eddy current heating signals are differentially encoded so that the same signal is transmitted in the form of a pair of electrical signals with equal amplitude and opposite phase, and the power adjustment parameters in the directional eddy current heating signals are encapsulated according to the frame structure to transmit directional eddy current heating signals under strong electromagnetic interference environment.

9. The method according to claim 4, characterized in that, The fanless cooling solution includes a gas holder self-circulating gas cooling system and a Peltier solid-state active cooling heat dissipation system. The gas holder self-circulating gas cooling system has a built-in spiral guide channel, which allows the gas inside the gas holder to generate natural convection after being heated and circulate along a preset path. It also uses the density difference formed by the temperature gradient inside the gas holder to drive the gas self-circulation flow, transferring heat from the high-temperature area to the gas holder wall or heat dissipation structure, forming a gas holder gas production-heat dissipation cavity-downstream self-circulation loop. The Peltier solid-state active cooling and heat dissipation system applies a control current to control the thermal coupling between the cold end and the heat-generating end, actively extracts the heat generated by the heat-generating end, and thermally connects it with the heat dissipation structure, releasing the extracted heat to the external environment to complete active temperature control and heat dissipation.

10. The method according to claim 2, characterized in that, The method for setting the safe cooling temperature range is as follows: Based on the allowable operating temperature range of the liquid source bottle, determine the corresponding minimum safe temperature threshold and maximum safe temperature threshold, and combine the heat dissipation capacity of the gas holder self-circulating gas cooling system and the Peltier solid-state active cooling heat dissipation system under the fanless cooling scheme to modify the minimum safe temperature threshold and maximum safe temperature threshold, and set the safe cooling temperature range.

11. The method according to claim 7, characterized in that, The method for limiting the execution power using the built-in safety interlock logic is as follows: Based on the impedance state of the intermediate frequency induction heating load and the operating state of the cooling system, it is determined whether there is over-temperature or abnormal load impedance. When any parameter is detected to exceed the corresponding safety threshold, the safety interlock control is triggered, and power limitation is executed according to the level of abnormality. The safety interlock control includes: when a minor abnormality is detected, the inverter output power is limited or the frequency offset is controlled; when a moderate abnormality is detected, the Peltier solid-state active cooling system is triggered and the output of the directional eddy current heating signal is limited; when a severe abnormality is detected, the full-bridge insulated inverter topology is immediately shut down and the system is kept in a locked state until the abnormality is resolved or the system is reset, and the interlock state is maintained until the abnormality is resolved.

12. A dual-loop control system for semiconductor liquid source medium-frequency induction heating, used to execute the method as described in any one of claims 1-11, characterized in that, include: Intermediate Frequency Resonance Control Module: Acquires the intermediate frequency induced current frequency, controls the frequency range of the output intermediate frequency AC power based on the full-bridge insulated inverter topology, and synchronously adjusts the resonant frequency through a phase-locked loop to ensure that the inverter output frequency always tracks the load resonant point, providing the basis for liquid source heating control; Temperature and pressure dual-loop control module: Constructs a temperature-pressure dual-loop feedback curve to collect the temperature and pressure signals of the liquid source bottle wall in real time, compare them with the corresponding target set values, generate temperature deviation signals and pressure deviation signals, dynamically adjust the inverter output power through proportional-integral algorithm, control the amplitude and distribution of the medium frequency induction heating current, and generate directional eddy current heating signals. Differential shielded transmission module: Based on the return path formed by the induced current of the directional eddy current heating signal, a closed electromagnetic shielding circuit is constructed, and the signal is transmitted to the flexible heating coil through a twisted-pair shielded wire and a differential signal interface via a differential serial communication protocol to induce the eddy current heating liquid source; Cooling interlock limiting module: Based on the fanless cooling scheme, it controls the temperature of the induced eddy current heat source and adjusts the cooling intensity by linking the intermediate frequency induced electric frequency. When the liquid source temperature deviates from the preset safe cooling temperature range, it performs power limiting based on the built-in safety interlock logic when the load impedance is abnormal.

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