Matcher and plasma generating device

Abstract

The utility model discloses a matcher and a plasma generating device, and relates to the impedance matching technology field, the matcher comprises a main control circuit, a first switch circuit, a second switch circuit, a first voltage detection circuit and a second voltage detection circuit, the detection end of the first voltage detection circuit is electrically connected with the input end of the first switch circuit; the output end of the first voltage detection circuit is electrically connected with the detection end of the main control circuit; the detection end of the second voltage detection circuit is electrically connected with the input end of the second switching circuit, the output end of the second voltage detection circuit is electrically connected with the detection end of the main control circuit, and when the voltage of the input end of the first switching circuit is zero, the main control circuit controls the second switching circuit to be switched on; when the voltage of the input end of the second switching circuit is zero, the main control circuit controls the first switching circuit to be switched on; the utility model aims to solve the problem that the output power of the radio frequency power supply is low due to the countercurrent phenomenon of the half-bridge or full-bridge driving circuit.

Description

Technical Field

[0001] The utility model relates to the technical field of impedance matching, in particular to a matching device and a plasma generating device. Background Art

[0002] In plasma chamber applications, the RF power supply is responsible for providing energy to the plasma. However, due to the nonlinear characteristics of the load in the plasma chamber, its impedance is often not equal to the constant output impedance of the RF power supply. This impedance mismatch will cause a large amount of reflected power on the transmission line between the RF power supply and the plasma chamber, which means that the power generated by the RF power supply cannot be efficiently delivered to the plasma chamber, resulting in significant power loss.

[0003] To this end, an impedance matching network needs to be set up between the RF power supply system and the plasma chamber. By fine-tuning this impedance matching network, it is possible to ensure that the impedance of the matching network is combined with the nonlinear load impedance in the plasma chamber, achieve impedance matching between the RF power supply and the plasma chamber, and achieve maximum output power.

[0004] The existing RF power supply generally includes a power supply, a power amplifier module, a RF power detection module and a RF interlock control module. The power supply is connected to the mains through a rectifier circuit. The rectifier circuit generally includes a half-bridge or full-bridge drive circuit. The half-bridge or full-bridge drive circuit controls the conduction and cutoff of the upper bridge arm and the lower bridge arm switch devices at an appropriate time according to the input of the control signal. By accurately controlling the state of the switch, the half-bridge drive circuit can control the output of the power supply voltage and the regulation of the output power. However, since it takes a certain amount of time for the switch tube to be completely turned off, when the upper bridge arm switch or the lower bridge arm switch is not completely turned off, the other bridge arm switch is turned on, so that part of the current of the rear-stage circuit (resonant inductor or transformer) will flow back to the front-stage circuit. The reverse flow phenomenon will consume a certain amount of energy, which will not only reduce the output power of the RF power supply, but also may cause the voltage and current fluctuations of the power supply output. This fluctuation will affect the stability and performance of the plasma generator, thereby affecting the quality of the generated plasma. Utility Model Content

[0005] The main purpose of the utility model is to provide a matcher and a plasma generating device, aiming to solve the problem that the radio frequency power supply has low output power due to the reverse current phenomenon in the half-bridge or full-bridge driving circuit.

[0006] To achieve the above object, the utility model provides a matcher, comprising:

[0007] Impedance matching circuit;

[0008] Main control circuit;

[0009] a first switch circuit, wherein an input end of the first switch circuit is connected to a positive electrode of an external power supply, an output end of the first switch circuit is electrically connected to a first end of the impedance matching circuit, a controlled end of the first switch circuit is electrically connected to a control end of the main control circuit, and the positive electrode of the external power supply is also electrically connected to a second end of the impedance matching circuit;

[0010] a second switch circuit, wherein an input end of the second switch circuit is electrically connected to an output end of the first switch circuit and a first end of the impedance matching circuit, an output end of the second switch circuit is electrically connected to a second end of the impedance matching circuit and a negative electrode of an external power supply, and a controlled end of the second switch circuit is electrically connected to a control end of the main control circuit;

[0011] a first voltage detection circuit, wherein a detection end of the first voltage detection circuit is electrically connected to an input end of the first switch circuit, the first voltage detection circuit is used to detect a voltage at the input end of the first switch circuit and output a corresponding first voltage detection signal, and an output end of the first voltage detection circuit is electrically connected to a detection end of the main control circuit;

[0012] a second voltage detection circuit, wherein a detection end of the second voltage detection circuit is electrically connected to an input end of the second switch circuit, the second voltage detection circuit is used to detect a voltage at the input end of the second switch circuit and output a corresponding second voltage detection signal, and an output end of the second voltage detection circuit is electrically connected to a detection end of the main control circuit;

[0013] When the voltage at the input end of the first switch circuit is zero, the main control circuit controls the second switch circuit to be turned on; when the voltage at the input end of the second switch circuit is zero, the main control circuit controls the first switch circuit to be turned on.

[0014] In one embodiment, the first voltage detection circuit includes:

[0015] a first voltage divider circuit and a first comparator circuit, wherein a first end of the first voltage divider circuit is electrically connected to an input end of the first switch circuit, a second end of the first voltage divider circuit is electrically connected to an inverting end of the first comparator circuit, a non-inverting end of the first comparator circuit is used to access a reference source circuit, and an output end of the first comparator circuit is electrically connected to a detection end of the main control circuit;

[0016] The second voltage detection circuit comprises:

[0017] A second voltage divider circuit and a second comparator circuit, wherein the first end of the second voltage divider circuit is electrically connected to the input end of the second switch circuit, the second end of the second voltage divider circuit is electrically connected to the inverting end of the second comparator circuit, the non-inverting end of the second comparator circuit is used to access the reference source circuit, and the output end of the second comparator circuit is electrically connected to the detection end of the main control circuit.

[0018] In one embodiment, the first voltage detection circuit includes:

[0019] A first voltage sensor, a first voltage follower and a first filtering circuit, wherein a detection end of the first voltage sensor is electrically connected to an input end of the first switch circuit, an output end of the first voltage sensor is electrically connected to an input end of the first voltage follower, an output end of the first voltage follower is electrically connected to an input end of the first filtering circuit, and an output end of the first filtering circuit is electrically connected to a detection end of the main control circuit;

[0020] The second voltage detection circuit comprises:

[0021] A second voltage sensor, a second voltage follower and a second filtering circuit, wherein the detection end of the second voltage sensor is electrically connected to the input end of the second switching circuit, the output end of the second voltage sensor is electrically connected to the input end of the second voltage follower, the output end of the second voltage follower is electrically connected to the input end of the second filtering circuit, and the output end of the second filtering circuit is electrically connected to the detection end of the main control circuit.

[0022] In one embodiment, the first filtering circuit includes:

[0023] a first resistor and a first capacitor, wherein a first end of the first resistor is electrically connected to an output end of the first voltage follower, a second end of the first resistor is electrically connected to a first end of the first capacitor and a detection end of the main control circuit respectively, and a second end of the first capacitor is grounded;

[0024] The second filtering circuit comprises:

[0025] A second resistor and a second capacitor, wherein the first end of the second resistor is electrically connected to the output end of the second voltage follower, the second end of the second resistor is electrically connected to the first end of the second capacitor and the detection end of the main control circuit respectively, and the second end of the second capacitor is grounded.

[0026] In one embodiment, the first switch circuit includes:

[0027] A first switch tube, wherein the input end of the first switch tube is electrically connected to the positive electrode of an external power supply, the output end of the first switch tube is electrically connected to the first end of the impedance matching circuit and the input end of the second switch circuit, and the controlled end of the first switch circuit is electrically connected to the control end of the main control circuit.

[0028] In one embodiment, the second switch circuit includes:

[0029] A second switch tube, wherein the input end of the second switch tube is electrically connected to the output end of the first switch circuit and the first end of the impedance matching circuit respectively, the output end of the second switch tube is electrically connected to the second end of the impedance matching circuit and the negative electrode of the external power supply respectively, and the controlled end of the second switch tube is electrically connected to the control end of the main control circuit.

[0030] In one embodiment, the matcher further includes:

[0031] A third voltage detection circuit, wherein the detection end of the third voltage detection circuit is electrically connected to the first end of the impedance matching circuit, the output end of the third voltage detection circuit is electrically connected to the detection end of the main control circuit, the third voltage detection circuit is used to detect the voltage of the impedance matching circuit and output a corresponding third voltage detection signal to the main control circuit, and the main control circuit outputs corresponding control signals to the controlled end of the first switch circuit and the controlled end of the second switch circuit according to the third voltage detection signal.

[0032] In one implementation, the third voltage detection circuit includes:

[0033] A third voltage sensor and a third voltage follower, wherein the detection end of the third voltage sensor is electrically connected to the first end of the impedance matching circuit, the output end of the third voltage sensor is electrically connected to the input end of the third voltage follower, and the output end of the third voltage follower is electrically connected to the detection end of the main control circuit.

[0034] The utility model also provides a plasma generating device, comprising any one of the matching devices described above.

[0035] The technical scheme of the utility model comprises an impedance matching circuit, a main control circuit, a first switch circuit, a second switch circuit, a first voltage detection circuit and a second voltage detection circuit. If the circuit is in the stage of converting the positive half cycle into the negative half cycle, when the voltage at the input end of the first switch circuit drops to zero volts, that is, when it is completely turned off, the main control circuit controls the second switch circuit to be turned on according to the first voltage detection signal, so that the second switch circuit is turned on only when the first switch circuit is completely turned off; similarly, when the circuit is in the stage of converting the negative half cycle into the positive half cycle, when the voltage at the input end of the second switch circuit is zero volts, the main control circuit controls the first switch circuit to be turned on according to the second voltage detection signal. Such arrangement avoids that when the second switch circuit or the first switch circuit is turned on, part of the current of the rear stage circuit (impedance matching circuit or transformer) is reversely fed to the front stage circuit through the first switch circuit or the second switch circuit that is not completely turned off, thereby causing more energy to be lost, and makes the power supply signal received by the impedance matching circuit relatively stable, ensuring that the impedance matching circuit maintains stable performance for a long time, so as to improve the stability, generation efficiency and equipment reliability of the plasma generated by the plasma generating device used in the matching device of the utility model in practical applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0037] Figure 1 A schematic diagram of the circuit structure of an embodiment of a matcher provided by the utility model;

[0038] Figure 2 A schematic diagram of the circuit structure of another embodiment of the matching device provided by the utility model;

[0039] Figure 3 A schematic diagram of the circuit structure of another embodiment of the matching device provided by the utility model;

[0040] Figure 4 A schematic diagram of the circuit structure of another embodiment of the matching device provided by the utility model;

[0041] Figure 5 This is a schematic diagram of the circuit structure of another embodiment of the matcher provided by the utility model.

[0042] Description of Figure Numbers:

[0043] 10. Impedance matching circuit; 20. Main control circuit; 30. First switch circuit; 40. Second switch circuit; 50. First voltage detection circuit; 51. First filter circuit; 60. Second voltage detection circuit; 61. Second filter circuit; 70. Third voltage detection circuit.

[0044] The realization of the purpose, functional features and advantages of the utility model will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0045] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0046] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back...), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0047] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the utility model, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the utility model.

[0048] In plasma chamber applications, the RF power supply is responsible for providing energy to the plasma. However, due to the nonlinear characteristics of the load in the plasma chamber, its impedance is often not equal to the constant output impedance of the RF power supply. This impedance mismatch will cause a large amount of reflected power on the transmission line between the RF power supply and the plasma chamber, which means that the power generated by the RF power supply cannot be efficiently delivered to the plasma chamber, resulting in significant power loss.

[0049] To this end, an impedance matching network needs to be set up between the RF power supply system and the plasma chamber. By fine-tuning this impedance matching network, it is possible to ensure that the impedance of the matching network is combined with the nonlinear load impedance in the plasma chamber, achieve impedance matching between the RF power supply and the plasma chamber, and achieve maximum output power.

[0050] The existing RF power supply generally includes a power supply, a power amplifier module, a RF power detection module and a RF interlock control module. The power supply is connected to the mains through a rectifier circuit. The rectifier circuit generally includes a half-bridge or full-bridge drive circuit. The half-bridge or full-bridge drive circuit controls the conduction and cutoff of the upper bridge arm and the lower bridge arm switch devices at an appropriate time according to the input of the control signal. By accurately controlling the state of the switch, the half-bridge drive circuit can control the output of the power supply voltage and the regulation of the output power. However, since it takes a certain amount of time for the switch tube to be completely turned off, when the upper bridge arm switch or the lower bridge arm switch is not completely turned off, the other bridge arm switch is turned on, so that part of the current of the rear-stage circuit (resonant inductor or transformer) will flow back to the front-stage circuit. The reverse flow phenomenon will consume a certain amount of energy, which will not only reduce the output power of the RF power supply, but also may cause the voltage and current fluctuations of the power supply output. This fluctuation will affect the stability and performance of the plasma generator, thereby affecting the quality of the generated plasma.

[0051] To this end, the utility model proposes a matcher and a plasma generating device, aiming to solve the problem of low output power of the RF power supply due to the reverse current phenomenon in the half-bridge or full-bridge driving circuit.

[0052] refer to Figure 1 In one embodiment of the present invention, a matcher includes:

[0053] Impedance matching circuit 10;

[0054] Main control circuit 20;

[0055] a first switch circuit 30, wherein an input end of the first switch circuit 30 is connected to a positive electrode of an external power source, an output end of the first switch circuit 30 is electrically connected to a first end of the impedance matching circuit 10, a controlled end of the first switch circuit 30 is electrically connected to a control end of the main control circuit 20, and a positive electrode of the external power source is also electrically connected to a second end of the impedance matching circuit 10;

[0056] a second switch circuit 40, wherein an input end of the second switch circuit 40 is electrically connected to an output end of the first switch circuit 30 and a first end of the impedance matching circuit 10, respectively; an output end of the second switch circuit 40 is electrically connected to a second end of the impedance matching circuit 10 and a negative electrode of an external power source, respectively; a controlled end of the second switch circuit 40 is electrically connected to a control end of the main control circuit 20, and a negative electrode of the external power source is also electrically connected to a second end of the impedance matching circuit 10;

[0057] a first voltage detection circuit 50, wherein a detection end of the first voltage detection circuit 50 is electrically connected to an input end of the first switch circuit 30, the first voltage detection circuit 50 is used to detect a voltage at the input end of the first switch circuit 30 and output a corresponding first voltage detection signal, and an output end of the first voltage detection circuit 50 is electrically connected to a detection end of the main control circuit 20;

[0058] a second voltage detection circuit 60, wherein a detection end of the second voltage detection circuit 60 is electrically connected to an input end of the second switch circuit 40, the second voltage detection circuit 60 is used to detect a voltage at the input end of the second switch circuit 40 and output a corresponding second voltage detection signal, and an output end of the second voltage detection circuit 60 is electrically connected to a detection end of the main control circuit 20;

[0059] When the voltage at the input end of the first switch circuit 30 is zero, the main control circuit 20 controls the second switch circuit 40 to be turned on; when the voltage at the input end of the second switch circuit 40 is zero, the main control circuit 20 controls the first switch circuit 30 to be turned on.

[0060] In this embodiment, the first switch circuit 30 and the second switch circuit 40 can both be implemented by using at least one switch tube, such as a MOS tube, an IGBT tube, a thyristor, a triode, a power tube, etc.

[0061] In this embodiment, the first switch circuit 30 includes:

[0062] A first switch tube Q1, wherein the input end of the first switch tube Q1 is electrically connected to the positive electrode of an external power supply, the output end of the first switch tube Q1 is electrically connected to the first end of the impedance matching circuit 10 and the input end of the second switch circuit 40, and the controlled end of the first switch circuit 30 is electrically connected to the control end of the main control circuit 20.

[0063] The second switch circuit 40 includes:

[0064] A second switch tube Q2, the input end of the second switch tube Q2 is electrically connected to the output end of the first switch circuit 30 and the first end of the impedance matching circuit 10 respectively, the output end of the second switch tube Q2 is electrically connected to the second end of the impedance matching circuit 10 and the negative electrode of the external power supply respectively, and the controlled end of the second switch tube Q2 is electrically connected to the control end of the main control circuit 20.

[0065] In this embodiment, both the first switch tube Q1 and the second switch tube Q2 are NMOS tubes, and both the first switch tube Q1 and the second switch tube Q2 have body diodes and parasitic capacitors.

[0066] In this embodiment, the matcher also includes a third capacitor C3 and a fourth capacitor C4, a first end of the third capacitor C3 is electrically connected to the positive electrode of the power supply, a second end of the third capacitor C3 is electrically connected to the second end of the impedance matching circuit 10, a first end of the fourth capacitor C4 is electrically connected to the negative electrode of the power supply, and a second end of the fourth capacitor C4 is electrically connected to the second end of the impedance matching circuit 10; the third capacitor C3 and the fourth capacitor C4 limit the transmission of high-frequency components in the current signal output by the power supply, thereby making it smoother.

[0067] In this embodiment, the main control circuit 20 can be implemented by a main controller, such as MCU (Microcontroller Unit), DSP (Digital Signal Process), FPGA (Field Programmable Gate Array), SOC (System On Chip), etc.

[0068] In this embodiment, the impedance matching circuit 10 can adopt one of an L-type impedance matching circuit, a T-type impedance matching circuit or a Π-type impedance matching circuit. The L-type matching circuit is usually composed of an inductor and a capacitor, and these two elements can be connected in series or in parallel; the T-type network impedance matching circuit is composed of two inductors connected in series and two capacitors connected in parallel; the Π-type network impedance matching circuit is composed of two capacitors connected in parallel and two inductors connected in series. By adjusting the values ​​of the inductor and the capacitor, the impedance of the signal source and the impedance of the load can be converted into matching impedances, thereby achieving maximum power transmission and minimum reflection loss.

[0069] refer to Figure 2 In this embodiment, the matcher can also use a transformer S1, the primary coil of the transformer S1 is connected to the first switch circuit 30 and the second switch circuit 40, the secondary coil of the transformer S1 is electrically connected to the first end and the second end of the impedance matching circuit 10, and the transformer S1 converts the input voltage into the required output voltage to meet the working requirements of the impedance matching circuit 10.

[0070] Specifically, the technical solution of the utility model includes an impedance matching circuit 10, a main control circuit 20, a first switch circuit 30, a second switch circuit 40, a first voltage detection circuit 50 and a second voltage detection circuit 60. If the circuit is in the stage of converting the positive half cycle to the negative half cycle, when the input voltage of the first switch circuit 30 drops to zero volts, that is, when it is completely turned off, the main control circuit 20 controls the second switch circuit 40 to turn on according to the first voltage detection signal, so that the second switch circuit 40 is turned on when the first switch circuit 30 is completely turned off; similarly, when the circuit is in the stage of converting the negative half cycle to the positive half cycle, when the input voltage of the second switch circuit 40 is zero volts, The main control circuit 20 controls the first switch circuit to be turned on according to the second voltage detection signal. This arrangement prevents part of the current of the subsequent circuit (impedance matching circuit or transformer) from flowing back to the previous circuit through the first switch circuit 30 or the second switch circuit 40 that is not completely turned off when the second switch circuit 40 or the first switch circuit 30 is turned on, thereby causing more energy to be lost, and makes the power supply signal received by the impedance matching circuit 10 more stable, ensuring that the impedance matching circuit 10 maintains stable performance for a long time, so as to improve the stability, generation efficiency and equipment reliability of the plasma generated by the plasma generating device used in the practical application of the matching device of the utility model.

[0071] Due to the delay caused by the comparator and gate circuit or wiring, it takes a certain amount of time for the first voltage detection signal or the second voltage detection signal to be detected and transmitted to the main control circuit 20, so that the first switch circuit 30 or the second switch circuit 40 is turned off in advance, which will cause the dead time between the first switch circuit 30 and the second switch circuit 40 (the first switch circuit 30 and the second switch circuit 40 are both in the off state) to be too long, and the current in the circuit will continue to flow through the body diode of the switch tube for a long time, thereby increasing the conduction loss and reducing the output power received by the impedance matching circuit 10.

[0072] refer to Figure 3 In one embodiment of the present utility model, the first voltage detection circuit 50 includes:

[0073] A first voltage divider circuit and a first comparator circuit U1, wherein a first end of the first voltage divider circuit is electrically connected to an input end of the first switch circuit 30, a second end of the first voltage divider circuit is electrically connected to an inverting end of the first comparator circuit U1, a non-inverting end of the first comparator circuit U1 is used to access a reference source circuit, and an output end of the first comparator circuit U1 is electrically connected to a detection end of the main control circuit 20;

[0074] The second voltage detection circuit 60 includes:

[0075] A second voltage divider circuit and a second comparator circuit U2, wherein a first end of the second voltage divider circuit is electrically connected to an input end of the second switch circuit 40, a second end of the second voltage divider circuit is electrically connected to an inverting end of the second comparator circuit U2, a non-inverting end of the second comparator circuit U2 is used to access a reference source circuit, and an output end of the second comparator circuit U2 is electrically connected to a detection end of the main control circuit 20.

[0076] In this embodiment, the first voltage divider circuit is used to collect the voltage at the input end of the first switch circuit 30 in the form of resistor voltage division. If the circuit is in the stage of the positive half cycle turning into the negative half cycle, when the voltage at the input end of the first switch circuit 30 drops to a preset value, wherein the preset value is less than the reference voltage output by the reference source circuit and greater than zero, the first comparison circuit outputs a corresponding control signal to the main control circuit 20, so that the main control circuit 20 controls the second switch circuit 40 to turn on. In this way, the first switch circuit 30 outputs a corresponding signal to the main control circuit 20 in advance and controls the second switch circuit 40 to turn on before it is completely turned off, thereby offsetting the delay caused by the comparator and gate circuit or routing, and shortening the dead time between the first switch circuit 30 and the second switch circuit 40. Among them, the circuit structure composed of the second voltage divider circuit and the second comparator circuit U2 is the same as the circuit structure composed of the first voltage divider circuit and the first comparator circuit U1, and the technical effects are also the same, which will not be repeated here.

[0077] When the switch circuit uses a MOS tube, there are parasitic capacitors in the MOS tube. When the MOS tube starts to conduct, these parasitic capacitors need to be charged or discharged. Since this process is transient, the voltage across the switch tube will fluctuate in a short time, thereby generating a certain peak voltage. If the peak voltage is transmitted to the main control circuit 20, it will damage the internal circuit of the main control circuit.

[0078] refer to Figure 4 , the first voltage detection circuit 50 includes:

[0079] A first voltage sensor, a first voltage follower U3 and a first filter circuit 51, wherein the detection end of the first voltage sensor is electrically connected to the input end of the first switch circuit 30, the output end of the first voltage sensor is electrically connected to the input end of the first voltage follower U3, the output end of the first voltage follower U3 is electrically connected to the input end of the first filter circuit 51, and the output end of the first filter circuit 51 is electrically connected to the detection end of the main control circuit 20;

[0080] The second voltage detection circuit 60 includes:

[0081] A second voltage sensor, a second voltage follower U4 and a second filter circuit 61, the detection end of the second voltage sensor is electrically connected to the input end of the second switch circuit 40, the output end of the second voltage sensor is electrically connected to the input end of the second voltage follower U4, the output end of the second voltage follower U4 is electrically connected to the input end of the second filter circuit 61, and the output end of the second filter circuit 61 is electrically connected to the detection end of the main control circuit 20.

[0082] In this embodiment, the first filtering circuit 51 includes:

[0083] a first resistor and a first capacitor, wherein a first end of the first resistor is electrically connected to an output end of the first voltage follower U3, a second end of the first resistor is electrically connected to a first end of the first capacitor and a detection end of the main control circuit 20, respectively, and a second end of the first capacitor is grounded;

[0084] The second filtering circuit 61 comprises:

[0085] A second resistor and a second capacitor, wherein the first end of the second resistor is electrically connected to the output end of the second voltage follower U4, the second end of the second resistor is electrically connected to the first end of the second capacitor and the detection end of the main control circuit 20 respectively, and the second end of the second capacitor is grounded.

[0086] In this embodiment, the voltage sensor may be any one of a resistor divider, a voltage transformer or a Hall voltage sensor.

[0087] In this embodiment, the voltage follower is used for signal isolation, that is, to completely isolate the main control circuit 20 from the first switch circuit 30 or the second switch circuit 40, thereby reducing the influence of interference and noise generated by the first switch circuit 30 or the second switch circuit 40 on the main control circuit 20.

[0088] In this embodiment, the first voltage sensor is used to collect the voltage at the input end of the first switch circuit 30 and output a corresponding first voltage detection signal. The first voltage detection signal is transmitted to the first filter circuit 51 via the first voltage follower U3. The first filter circuit 51 is used to further filter out the peak voltage in the first voltage detection signal so that the main control circuit 20 can receive a smooth detection signal and avoid the main control circuit 20 from being damaged by the peak voltage. Among them, the second voltage sensor and the second filter circuit 61 and the first voltage sensor and the first filter circuit 51 have the same circuit structure, and the technical effects they play are also the same, which will not be repeated here.

[0089] refer to Figure 5 In one embodiment of the present utility model, the matcher further includes:

[0090] A third voltage detection circuit 70, wherein the detection end of the third voltage detection circuit 70 is electrically connected to the first end of the impedance matching circuit 10, and the output end of the third voltage detection circuit 70 is electrically connected to the detection end of the main control circuit 20. The third voltage detection circuit 70 is used to detect the voltage of the impedance matching circuit 10 and output a corresponding third voltage detection signal to the main control circuit 20. The main control circuit 20 outputs corresponding control signals to the controlled end of the first switch circuit 30 and the controlled end of the second switch circuit 40 according to the third voltage detection signal.

[0091] In this embodiment, the third voltage detection circuit 70 includes:

[0092] A third voltage sensor and a third voltage follower U5, wherein the detection end of the third voltage sensor is electrically connected to the first end of the impedance matching circuit 10, the output end of the third voltage sensor is electrically connected to the input end of the third voltage follower U5, and the output end of the third voltage follower U5 is electrically connected to the detection end of the main control circuit 20.

[0093] In this embodiment, the third voltage detection circuit 70 is used to check the voltage of the first end of the impedance matching circuit 10. When the voltage of the first end of the impedance matching circuit 10 is too large, the main control circuit 20 outputs a PWM control signal with a lower duty cycle to the first switch circuit 30 and the second switch circuit 40 according to the third voltage detection circuit 70, so as to shorten the conduction time of the first switch circuit 30 and the second switch circuit 40, thereby reducing the power output from the power supply to the impedance matching circuit 10 through the first switch circuit 30 and the second switch circuit 40, thereby avoiding the impedance matching circuit 10 from not being able to work normally due to excessive voltage, that is, not being able to achieve impedance matching, and the components in the circuit can also avoid being damaged due to excessive voltage stress, such as capacitor breakdown, resistor burning or transistor failure.

[0094] The utility model also provides a plasma generating device, comprising the matching device as described above.

[0095] It is worth noting that, since the plasma generating device of the present invention is based on the above-mentioned matcher, the embodiments of the plasma generating device of the present invention include all technical solutions of all embodiments of the above-mentioned matcher, and the technical effects achieved are also exactly the same, which will not be repeated here.

[0096] The above description is only an exemplary embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A matcher, characterized in that: include: Impedance matching circuit; Main control circuit; a first switch circuit, wherein an input end of the first switch circuit is connected to a positive electrode of an external power supply, an output end of the first switch circuit is electrically connected to a first end of the impedance matching circuit, a controlled end of the first switch circuit is electrically connected to a control end of the main control circuit, and the positive electrode of the external power supply is also electrically connected to a second end of the impedance matching circuit; a second switch circuit, wherein an input end of the second switch circuit is electrically connected to an output end of the first switch circuit and a first end of the impedance matching circuit, an output end of the second switch circuit is electrically connected to a second end of the impedance matching circuit and a negative electrode of an external power supply, and a controlled end of the second switch circuit is electrically connected to a control end of the main control circuit; a first voltage detection circuit, wherein a detection end of the first voltage detection circuit is electrically connected to an input end of the first switch circuit, the first voltage detection circuit is used to detect a voltage at the input end of the first switch circuit and output a corresponding first voltage detection signal, and an output end of the first voltage detection circuit is electrically connected to a detection end of the main control circuit; a second voltage detection circuit, wherein a detection end of the second voltage detection circuit is electrically connected to an input end of the second switch circuit, the second voltage detection circuit is used to detect a voltage at the input end of the second switch circuit and output a corresponding second voltage detection signal, and an output end of the second voltage detection circuit is electrically connected to a detection end of the main control circuit; When the voltage at the input end of the first switch circuit is zero, the main control circuit controls the second switch circuit to be turned on; when the voltage at the input end of the second switch circuit is zero, the main control circuit controls the first switch circuit to be turned on.

2. The matcher according to claim 1, characterized in that: The first voltage detection circuit comprises: a first voltage divider circuit and a first comparator circuit, wherein a first end of the first voltage divider circuit is electrically connected to an input end of the first switch circuit, a second end of the first voltage divider circuit is electrically connected to an inverting end of the first comparator circuit, a non-inverting end of the first comparator circuit is used to access a reference source circuit, and an output end of the first comparator circuit is electrically connected to a detection end of the main control circuit; The second voltage detection circuit comprises: A second voltage divider circuit and a second comparator circuit, wherein the first end of the second voltage divider circuit is electrically connected to the input end of the second switch circuit, the second end of the second voltage divider circuit is electrically connected to the inverting end of the second comparator circuit, the non-inverting end of the second comparator circuit is used to access the reference source circuit, and the output end of the second comparator circuit is electrically connected to the detection end of the main control circuit.

3. The matcher according to claim 1, characterized in that: The first voltage detection circuit comprises: A first voltage sensor, a first voltage follower and a first filtering circuit, wherein the detection end of the first voltage sensor is electrically connected to the input end of the first switch circuit, the output end of the first voltage sensor is electrically connected to the input end of the first voltage follower, the output end of the first voltage follower is electrically connected to the input end of the first filtering circuit, and the output end of the first filtering circuit is electrically connected to the detection end comparison circuit of the main control circuit; The second voltage detection circuit comprises: A second voltage sensor, a second voltage follower and a second filtering circuit, wherein the detection end of the second voltage sensor is electrically connected to the input end of the second switching circuit, the output end of the second voltage sensor is electrically connected to the input end of the second voltage follower, the output end of the second voltage follower is electrically connected to the input end of the second filtering circuit, and the output end of the second filtering circuit is electrically connected to the detection end of the main control circuit.

4. The matcher according to claim 3, characterized in that: The first filtering circuit comprises: a first resistor and a first capacitor, wherein a first end of the first resistor is electrically connected to an output end of the first voltage follower, a second end of the first resistor is electrically connected to a first end of the first capacitor and a detection end of the main control circuit respectively, and a second end of the first capacitor is grounded; The second filtering circuit comprises: A second resistor and a second capacitor, wherein the first end of the second resistor is electrically connected to the output end of the second voltage follower, the second end of the second resistor is electrically connected to the first end of the second capacitor and the detection end of the main control circuit respectively, and the second end of the second capacitor is grounded.

5. The matcher according to claim 1, characterized in that: The first switch circuit comprises: A first switch tube, wherein the input end of the first switch tube is electrically connected to the positive electrode of an external power supply, the output end of the first switch tube is electrically connected to the first end of the impedance matching circuit and the input end of the second switch circuit, and the controlled end of the first switch circuit is electrically connected to the control end of the main control circuit.

6. The matcher according to claim 1, characterized in that: The second switch circuit comprises: A second switch tube, wherein the input end of the second switch tube is electrically connected to the output end of the first switch circuit and the first end of the impedance matching circuit respectively, the output end of the second switch tube is electrically connected to the second end of the impedance matching circuit and the negative electrode of the external power supply respectively, and the controlled end of the second switch tube is electrically connected to the control end of the main control circuit.

7. The matching device according to any one of claims 1 to 6, characterized in that: The matcher also includes: A third voltage detection circuit, wherein the detection end of the third voltage detection circuit is electrically connected to the first end of the impedance matching circuit, the output end of the third voltage detection circuit is electrically connected to the detection end of the main control circuit, the third voltage detection circuit is used to detect the voltage of the impedance matching circuit and output a corresponding third voltage detection signal to the main control circuit, and the main control circuit outputs corresponding control signals to the controlled end of the first switch circuit and the controlled end of the second switch circuit according to the third voltage detection signal.

8. The matcher according to claim 7, characterized in that: The third voltage detection circuit comprises: A third voltage sensor and a third voltage follower, wherein the detection end of the third voltage sensor is electrically connected to the first end of the impedance matching circuit, the output end of the third voltage sensor is electrically connected to the input end of the third voltage follower, and the output end of the third voltage follower is electrically connected to the detection end of the main control circuit.

9. A plasma generating device, characterized in that: Comprising a matcher as described in any one of claims 1 to 8.

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