Plasma asher and ignition method

Abstract

The present invention provides a plasma asher and an ignition method, which includes a Faraday cup, a quartz tube, an inductance coil and an ignition device. The top wall of the Faraday cup is grounded; the quartz tube is arranged inside the Faraday cup and forms a plasma cavity; the inductance coil is wound around the outer periphery of the Faraday cup and is used to receive high-voltage high-frequency signals; the ignition device is connected to the inductance coil and forms an equivalent capacitance between the inductance coil and / or the Faraday cup; wherein, the equivalent capacitance is used to couple high-frequency high voltage from the inductance coil, and a high electric field strength for ionizing gas is formed inside the plasma cavity based on the discharge of the equivalent capacitance, and the ignition device conducts the top wall and / or the side wall of the Faraday cup as the density of the plasma obtained by continuous ionization of the gas in the plasma cavity increases. The plasma asher provided by the present invention can achieve rapid ignition, and the ignition device can be automatically grounded after ignition. The present invention also provides an ignition method based on the plasma asher.

Description

Technical Field

[0001] The present invention belongs to the technical field of plasma processing, and particularly relates to a plasma asher and an ignition method. Background Art

[0002] The working principle of a plasma asher is to generate a high-frequency magnetic field by using a high-voltage high-frequency signal input to an inductance coil, thereby exciting the ionization of gas in a plasma cavity to form a plasma and achieve ignition. Currently, in order to improve the stability and controllability of the plasma ashing process, a Faraday cylinder is usually arranged between the inductance coil and the plasma cavity. Due to the electric field shielding effect of the Faraday cylinder, when the inductance coil obtains a high-voltage high-frequency signal, it often takes several seconds to successfully ignite, and even there may be a situation of ignition failure. And a complete working cycle of the plasma asher is usually about ten seconds. Therefore, the ignition duration has a very serious impact on the working performance of the asher.

[0003] To solve the above problems, usually a high-voltage DC power supply is added to generate an instantaneous high-voltage electric field required for ignition, and a corresponding control system is added to control the voltage output. However, the additional high-voltage DC power supply and control system increase the complexity and cost of the equipment. Not only more funds are needed to purchase the equipment, but also the maintenance difficulty and cost of the equipment are increased. In addition, the switching control strategy of the high-voltage DC power supply requires extremely high requirements, and it is very easy to have safety hazards such as electrical breakdown and discharge caused by high-voltage accumulation. Summary of the Invention

[0004] An embodiment of the present invention provides a plasma asher and an ignition method, aiming to improve the safety and ignition efficiency of the plasma asher.

[0005] To achieve the above object, the technical solution adopted by the present invention is: In a first aspect, it includes a Faraday cylinder, a quartz cylinder, an inductance coil, and an ignition device. The top wall of the Faraday cylinder is grounded; the quartz cylinder is arranged inside the Faraday cylinder so that a plasma cavity is formed inside the Faraday cylinder; the inductance coil is wound around the outer periphery of the Faraday cylinder and is used to receive a high-voltage high-frequency signal; the ignition device is connected to the inductance coil and forms an equivalent capacitance between the inductance coil and / or the Faraday cylinder; wherein, the equivalent capacitance is used to couple high-frequency high voltage from the inductance coil, and a high electric field strength for ionizing gas is formed inside the plasma cavity based on the discharge of the equivalent capacitance, and the ignition device conducts the top wall and / or side wall of the Faraday cylinder as the density of the plasma obtained by continuous ionization of the gas in the plasma cavity increases.

[0006] In combination with the first aspect, in a possible implementation manner, the ignition device includes an insulating clamping member and a conductive band. The insulating clamping member is clamped on the inductance coil, the conductive band is arranged on the insulating clamping member, and the conductive band extends into the Faraday cylinder and contacts the side wall of the quartz cylinder; wherein, an equivalent capacitance is formed between the conductive band and both the inductance coil and the Faraday cylinder.

[0007] In some embodiments, the conductive strip includes a first straight section and a second straight section; the first straight section is parallel and spaced from the inductor coil to form a first equivalent capacitance; the second straight section is parallel and spaced from the side wall of the Faraday cylinder to form a second equivalent capacitance.

[0008] Exemplarily, the first straight section is lapped and fixed on the upper surface of the insulating card and is spaced vertically from the inductor coil, and the second straight section is bent downward or upward at the end of the first straight section close to the Faraday cylinder.

[0009] In some embodiments, the conductive strip further includes a third straight section; wherein, both ends of the third straight section are perpendicularly connected to the first straight section and the second straight section respectively; the first straight section is vertically mounted on the side wall of the insulating card facing the Faraday cylinder and is horizontally spaced from the inductor coil; the second straight section is located between the first straight section and the side wall of the Faraday cylinder.

[0010] Illustratively, a resistor is connected in series on the third straight section.

[0011] In some embodiments, the ignition device includes a conductive row, one end of the conductive row is lapped and fixed on the inductor coil and is electrically connected to the inductor coil, and the other end of the conductive row is parallel and spaced from the side wall of the Faraday cylinder to form an equivalent capacitance.

[0012] Combined with the first aspect, in a possible implementation manner, the capacitance value C of the equivalent capacitance satisfies C = εS / 4πkd; wherein, ε is the dielectric constant; the facing area between the ignition device and the inductor coil and the facing area between the ignition device and the Faraday cylinder are both S; the distance between the ignition device and the inductor coil and the distance between the ignition device and the Faraday cylinder are both d; k is the electrostatic constant.

[0013] In some embodiments, the plasma asher further includes a vacuum capacitor and a matcher; wherein, the matcher is electrically connected to the inductor coil and is used to output a high-voltage high-frequency signal, and the vacuum capacitor is connected in series between the matcher and the inductor coil.

[0014] The beneficial effects of the plasma asher provided by the present invention are as follows: Compared with the prior art, by adding an ignition device to the inductance coil in the present invention, when a high-voltage high-frequency signal is input, an equivalent capacitance is formed between the ignition device, the inductance coil, and the side wall of the Faraday cylinder. The equivalent capacitance couples the high-voltage high-frequency voltage from the inductance coil and releases high voltage into the interior of the Faraday cylinder, generating a high electric field strength in the region between the ignition device and the top wall of the Faraday cylinder to achieve gas ionization ignition. Thus, the ignition process is not affected by the shielding of the electric field by the Faraday cylinder, improving the ignition efficiency and stability of the asher; after the ignition device ionizes and ignites the gas, it continuously generates plasma. The continuously generated plasma reduces the impedance between the ignition device and the top wall of the Faraday cylinder, enabling the ignition device to achieve automatic grounding and conducting the voltage in the ignition device to the ground. The ignition device is equivalent to an automatic plasma switch and can be automatically turned off, which can not only avoid safety hazards such as electrical breakdown and discharge caused by high-voltage accumulation, improving the use safety and operation stability of the equipment, but also does not require an additional control strategy for the ignition device, thus reducing costs.

[0015] In a second aspect, an embodiment of the present invention further provides an ignition method based on a plasma asher, including:

[0016] Output a high-voltage high-frequency signal to the inductance coil so that a target voltage is obtained on the inductance coil;

[0017] Take power from the inductance coil using a conductive band or conductive bar and charge the equivalent capacitance;

[0018] The equivalent capacitance releases high voltage into the plasma cavity so that a high electric field strength is formed between the conductive band or conductive bar and the top wall of the Faraday cylinder;

[0019] The gas in the plasma cavity is ionized under the high electric field strength to complete ignition;

[0020] After ignition is completed, continue to output a high-voltage high-frequency signal to the inductance coil so that the inductance coil generates a periodically varying current;

[0021] An electric field for continuously ionizing gas to obtain plasma is formed inside the plasma cavity based on the periodically varying current;

[0022] The density of the plasma in the plasma cavity gradually increases based on the continuous ionization process until the plasma conducts the conductive band or conductive bar and the grounded top wall of the Faraday cylinder.

[0023] The beneficial effects of the ignition method provided by the present invention are as follows: Compared with the prior art, the conductive band or conductive busbar draws power from the inductance coil and charges the equivalent capacitor. The equivalent capacitor enters the interior of the Faraday cylinder and releases high-voltage electricity into the plasma cavity to form a high electric field strength between the conductive band or conductive busbar and the top wall of the Faraday cylinder, ionizing the gas in this area to achieve ignition. The conductive band extends into the interior of the Faraday cylinder for ignition, so that the ignition process is not affected by the electric field shielding of the Faraday cylinder, enabling rapid ignition of the plasma asher and improving work efficiency. After successful ignition, the plasma density inside the plasma cavity gradually increases, and the impedance between the conductive band or conductive busbar and the top wall of the Faraday cylinder decreases until the conductive band is in conduction with the top wall of the Faraday cylinder, enabling automatic grounding of the ignition device, guiding the voltage inside the ignition device to the ground, avoiding the accumulation of high voltage when the high-voltage high-frequency signal is input in the next cycle, and improving the safety of equipment use. The ignition device is equivalent to an automatic plasma switch. In the initial state without plasma, the ignition device obtains high voltage and achieves ignition; when the plasma is generated, the ignition device is grounded and can automatically turn off, avoiding affecting the normal operation of the asher. There is no need to add an additional ignition device control system, which is convenient to operate, simplifies the overall structure of the equipment, and saves the cost of equipment upgrade and transformation. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 FIG. is a schematic three-dimensional structure diagram of a plasma asher provided by an embodiment of the present invention;

[0025] Figure 2 FIG. is a schematic three-dimensional structure diagram of an ignition device provided by an embodiment of the present invention Figure 1 ;

[0026] Figure 3 FIG. is a schematic three-dimensional structure diagram of an ignition device provided by an embodiment of the present invention Figure 2 ;

[0027] Figure 4 FIG. is a schematic three-dimensional structure diagram of an ignition device provided by an embodiment of the present invention Figure 3 ;

[0028] Figure 5 FIG. is a schematic three-dimensional structure diagram of an ignition device provided by an embodiment of the present invention Figure 4 ;

[0029] Figure 6 FIG. is a schematic three-dimensional structure diagram of an ignition device provided by an embodiment of the present invention Figure 5 ;

[0030] Figure 7 FIG. is a schematic equivalent circuit diagram of an ignition device provided by an embodiment of the present invention during ignition Figure 1 ;

[0031] Figure 8 Schematic diagram of the equivalent circuit of the ignition device provided in an embodiment of the present invention during ignition Figure 2 ;

[0032] Figure 9 Schematic diagram of the equivalent circuit of the ignition device provided in an embodiment of the present invention during ignition Figure 3 ;

[0033] Figure 10 Schematic diagram of the equivalent circuit of the ignition device provided in an embodiment of the present invention after automatic grounding Figure 1 ;

[0034] Figure 11 Schematic diagram of the equivalent circuit of the ignition device provided in an embodiment of the present invention after automatic grounding Figure 2 ;

[0035] Figure 12 Schematic diagram of the equivalent circuit of the ignition device provided in an embodiment of the present invention after automatic grounding Figure 3 ;

[0036] In the figure: 10, Faraday cylinder; 20, quartz cylinder; 30, inductance coil; 40, ignition device; 41, insulating card; 42, conductive band; 421, first straight section; 422, second straight section; 423, third straight section; 43, resistor; 44, conductive busbar; 50, vacuum capacitor; 60, matcher; C1 - first equivalent capacitor; C2 - second equivalent capacitor; R - impedance; R1 - resistor. Specific embodiments

[0037] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0038] It should be noted that when an element is referred to as being "disposed on" another element, it can be directly on the other element or indirectly on the other element. It should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention. The terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or several of such features.

[0039] Please refer to Figure 1 for a description of the plasma asher provided by the present invention. The plasma asher includes a Faraday cup 10, a quartz cylinder 20, an inductor coil 30, and an ignition device 40. The top wall of the Faraday cup 10 is grounded; the quartz cylinder 20 is disposed inside the Faraday cup 10 to form a plasma cavity inside the Faraday cup 10; the inductor coil 30 is wound around the outer periphery of the Faraday cup 10 and is used to receive a high-voltage high-frequency signal; the ignition device 40 is connected to the inductor coil 30 and forms an equivalent capacitance between the inductor coil 30 and / or the Faraday cup 10; wherein, the equivalent capacitance is used to couple high-frequency high voltage from the inductor coil 30, and a high electric field strength for ionizing gas is formed inside the plasma cavity based on the discharge of the equivalent capacitance, and the ignition device 40 conducts the top wall and / or the side wall of the Faraday cup 10 as the density of the plasma obtained by continuous ionization of the gas inside the plasma cavity increases.

[0040] It should be noted that the inductor coil 30 can be made of copper and is wound around the Faraday cup 10 for three layers. The inductor coil 30 is designed based on the principle of electromagnetic induction, and the ignition device 40 obtains voltage through the electromagnetic change on the inductor coil 30. The top of the Faraday cup 10 can include two layers, the outer layer is a closed quartz flange, and the inner layer is a grounded metal plate. The side wall of the Faraday cup is also grounded. When there is no plasma, when a high-voltage high-frequency signal is input, the ignition device 40 can form an equivalent capacitance with the inductor coil 30 and the side wall of the Faraday cup 10, and the ignition device 40 thus has a high voltage. The ignition device 40 can cooperate with the grounded metal plate to generate a high electric field strength in the region between the two, so that the ignition device 40 is in an ignition state, and the gas in this region is ionized under the action of the high electric field strength to achieve ignition. After the plasma ignition is successful, the high-voltage high-frequency signal is still continuously input to continuously generate the plasma. As the density of the plasma continues to increase, the plasma can be regarded as a resistor connected in series between the ignition device 40 and the grounded metal plate. As the density of the plasma continues to increase, the impedance between the ignition device 40 and the grounded metal plate continues to decrease, thereby realizing the conduction between the ignition device 40 and the grounded metal plate to achieve grounding.

[0041] The beneficial effects of the plasma asher provided by the present invention are as follows: Compared with the prior art, by adding an ignition device 40 to the inductance coil 30, when a high-voltage high-frequency signal is input, an equivalent capacitor is formed between the ignition device 40, the inductance coil 30, and the side wall of the Faraday cylinder 10. The equivalent capacitor couples the high-voltage high-frequency voltage from the inductance coil 30 and releases high voltage into the interior of the Faraday cylinder 10, generating gas ionization ignition in the region between the ignition device 40 and the top wall of the Faraday cylinder 10, so that the ignition process is not affected by the shielding of the electric field by the Faraday cylinder 10, improving the ignition efficiency and stability of the asher; after ionizing and igniting the gas, the ignition device 40 continuously generates plasma, and the continuously generated plasma reduces the impedance between the ignition device 40 and the top wall of the Faraday cylinder 10, and conducts the voltage in the ignition device 40 to the ground. The ignition device 40 is equivalent to an automatic plasma switch and can be automatically turned off, which can not only avoid safety hazards such as electrical breakdown and discharge caused by high-voltage accumulation, improve the use safety and operation stability of the equipment, but also does not require an additional control strategy for the ignition device 40, thus reducing costs.

[0042] In a possible implementation, please refer to Figure 1 and Figure 2 , the ignition device 40 includes an insulating clamping member 41 and a conductive strip 42. The insulating clamping member 41 is clamped on the inductance coil 30, the conductive strip 42 is arranged on the insulating clamping member 41, and the conductive strip 42 extends into the Faraday cylinder 10 and contacts the side wall of the quartz cylinder 20; wherein, equivalent capacitors are formed between the conductive strip 42, the inductance coil 30, and the Faraday cylinder 10.

[0043] It should be noted that the insulating clamping member 41 is installed on the inductance coil 30 by a clamping method. Compared with other complex fixing methods, the installation process is simpler and faster, which can effectively save installation time and labor costs. At the same time, the clamping method can ensure that the insulating clamping member 41 is tightly combined with the inductance coil 30, and can be stably maintained in the set position during the operation of the equipment, without displacement or falling off, providing a reliable guarantee for the stable operation of the ignition device 40. The conductive strip 42 can be a copper strip and can directly contact the side wall of the quartz cylinder 20, which can shorten the voltage transmission path, reduce the energy loss during transmission, and transmit the voltage obtained from the inductance coil 30 to the conductive strip 42 more quickly and stably, providing stronger voltage support for ignition and improving the ignition success rate and ignition speed.

[0044] The insulating card 41 can be made of tetrafluoro material, which has excellent insulation performance. It can effectively isolate the high voltage on the inductance coil 30, prevent current leakage through the insulating card 41, and reduce potential safety hazards. The tetrafluoro material is reasonably priced, saving production and manufacturing costs while ensuring good performance. Distributed capacitance can be formed between any two conductors that are insulated from each other and close to each other. Both the first equivalent capacitance and the second equivalent capacitance are distributed capacitances. The existence of the distributed capacitance can make the electric field distribution more uniform, improving the stability of degumming. And it helps to enhance the energy coupling between the inductance coil 30 and the internal space of the Faraday cylinder 10, improving the energy transmission efficiency.

[0045] In some embodiments, referring to Figure 2 , Figure 7 and Figure 10 , the conductive strip 42 includes a first straight section 421 and a second straight section 422; the first straight section 421 is parallel and spaced from the inductance coil 30 to form a first equivalent capacitance; the second straight section 422 is parallel and spaced from the side wall of the Faraday cylinder 10 to form a second equivalent capacitance.

[0046] It should be noted that the first straight section 421 is parallel and spaced from the inductance coil 30 to form a first equivalent capacitance, and the parallel structure can effectively increase the electric field coupling area between the two. According to the characteristics of capacitance, in the same electric field environment, a larger facing area helps to increase the capacitance value of the capacitance, enabling the first equivalent capacitance to obtain voltage from the inductance coil 30 more efficiently. This provides a sufficient voltage basis for forming a high electric field strength in the plasma cavity subsequently, ensuring that the ignition device 40 can respond quickly and achieve the ignition function. The second straight section 422 is parallel and spaced from the side wall of the Faraday cylinder 10 to form a second equivalent capacitance, which can stably transfer the voltage obtained from the inductance coil 30 to the plasma cavity. The first equivalent capacitance and the second equivalent capacitance can enhance the energy coupling between the inductance coil 30 and the internal space of the Faraday cylinder 10, improve the energy transmission efficiency, and greatly reduce energy consumption. After the plasma density increases, the impedance between the ignition device 40 and the grounded metal plate at the top of the Faraday cylinder 10 decreases, and both the first equivalent capacitance and the second equivalent capacitance are automatically grounded through conduction with the grounded metal plate at the top of the Faraday cylinder 10 through the plasma, realizing the automatic shutdown of the ignition device 40 and avoiding potential safety hazards.

[0047] The setting of the first equivalent capacitance and the second equivalent capacitance enables a more uniform electric field distribution to be formed inside the plasma cavity. When the first equivalent capacitance obtains voltage, the voltage is transferred to the periphery of the plasma cavity through the second equivalent capacitance, enabling the electric field to cover the inside of the plasma cavity more uniformly, avoiding the situation of too strong or too weak local electric fields. A uniform electric field distribution is beneficial to improving the efficiency and uniformity of gas ionization, enabling the plasma to be generated more uniformly throughout the cavity, and thus improving the degumming effect and quality of the plasma degumming machine.

[0048] Exemplarily, refer to Figure 2 , the first straight section 421 is lapped and fixed on the upper surface of the insulating card 41 and is vertically spaced from the inductance coil 30, and the second straight section 422 is bent downward or upward at the end of the first straight section 421 close to the Faraday cylinder 10.

[0049] It should be noted that the first straight section 421 is lapped and fixed on the upper surface of the insulating card 41 and is vertically spaced from the inductance coil 30, which can accurately control the distance and relative position between the first straight section 421 and the inductance coil 30, and obtain the voltage from the inductance coil 30 more accurately, improving the stability and reliability of voltage acquisition. The second straight section 422 is bent downward or upward at the end of the first straight section 421 close to the Faraday cylinder 10, which can increase the facing area between the second straight section 422 and the side wall of the Faraday cylinder 10, enhancing the electric field coupling effect of the second equivalent capacitor. The second equivalent capacitor can store and transfer charges more effectively, further optimizing the process of voltage transfer from the first equivalent capacitor to the plasma cavity, helping to form a stronger and more stable high electric field intensity in the plasma cavity, and improving the efficiency of gas ionization and the ignition success rate.

[0050] In some embodiments, refer to Figure 3 、 Figure 7 and Figure 10 , the conductive strip 42 further includes a third straight section 423; wherein, the two ends of the third straight section 423 are respectively perpendicularly connected to the first straight section 421 and the second straight section 422; the first straight section 421 is vertically mounted on the side wall of the insulating card 41 facing the Faraday cylinder 10 and is horizontally spaced from the inductance coil 30; the second straight section 422 is located between the first straight section 421 and the side wall of the Faraday cylinder 10.

[0051] It should be noted that in this embodiment, the first straight section 421 is vertically arranged and forms a first equivalent capacitance with the inductor coil 30, the second straight section 422 is vertically arranged and forms a second equivalent capacitance with the side wall of the Faraday cylinder 10. A third straight section 423 is provided between the first straight section 421 and the second straight section 422. The third straight section 423 enables a closer electrical connection and cooperative relationship between the first straight section 421 and the second straight section 422. It can promote the charge transfer and electric field coupling between the first equivalent capacitance and the second equivalent capacitance, make the voltage distribution in the conductive strip 42 more reasonable, further optimize the formation and distribution of the internal electric field of the plasma cavity, and contribute to improving the efficiency and uniformity of gas ionization. Both ends of the third straight section 423 are perpendicularly connected to the first straight section 421 and the second straight section 422 respectively, forming a relatively stable overall structure. This right-angle connection method increases the mechanical strength of the conductive strip 42, enabling it to better resist vibration and external force impact during operation, reducing the change in the performance of the equivalent capacitance caused by structural deformation, and ensuring the long-term stable operation of the ignition device 40. The first straight section 421 is vertically mounted on the side wall of the insulating card 41 facing the Faraday cylinder 10. This layout makes full use of the space between the insulating card 41 and the Faraday cylinder 10, making the structure of the entire ignition device 40 more compact. At the same time, the second straight section 422 is located between the first straight section 421 and the side wall of the Faraday cylinder 10, further reasonably utilizing the limited space, which helps to reduce the overall volume of the plasma asher and improve the integration of the equipment. In this embodiment, after the plasma density increases, both the first equivalent capacitance and the second equivalent capacitance are automatically grounded through conduction with the grounding metal plate at the top of the Faraday cylinder 10 via the plasma.

[0052] For example, please refer to Figure 4 , Figure 8 and Figure 11 , a resistor 43 is connected in series on the third straight section 423.

[0053] It should be noted that the resistor 43 is connected in series on the third straight section 423, between the first equivalent capacitor and the second equivalent capacitor, and can precisely adjust the voltage distribution in the ignition state. During the ignition process, by adjusting the resistance value of the resistor 43, the voltage ratio on the two capacitors can be changed, so that when a high electric field strength is formed between the copper strip and the grounded metal plate, a more appropriate voltage value can be obtained. Ensure that a sufficient electric field strength can be stably generated under different working conditions to ionize the gas, improving the success rate and stability of ignition. The resistor 43 can also play a role in current limiting, preventing the conductive strip 42 from being damaged due to excessive current. When the voltage on the inductor coil 30 fluctuates, the resistor 43 can also limit the change amplitude of the current, ensuring that all parts of the ignition device 40 work within a safe current and voltage range, which can extend the service life of the device and reduce the maintenance cost. The optimization of voltage distribution achieved by adjusting the resistor 43 can more precisely control the generation process of plasma. After the plasma ignition is successful, the appropriate voltage distribution can make the current change on the inductor coil 30 more stable, and then excite a more stable magnetic field and electric field, which is beneficial to continuously and uniformly excite the plasma, improving the quality of the plasma and the degumming effect. And after the plasma density increases, the first equivalent capacitor and the second equivalent capacitor are conducted to the grounded metal plate at the top of the Faraday cylinder 10 to automatically ground, realizing the automatic shutdown of the ignition device 40 and avoiding potential safety hazards.

[0054] In another embodiment, please refer to Figure 5 , Figure 8 and Figure 11 , the ignition device 40 includes a first straight section 421 and a second straight section 422; the first straight section 421 is parallel and spaced from the inductor coil 30 to form a first equivalent capacitor; the second straight section 422 is parallel and spaced from the side wall of the Faraday cylinder 10 to form a second equivalent capacitor, and a resistor 43 is connected in series on the first straight section 421.

[0055] In some embodiments, please refer to Figure 6 , Figure 9 and Figure 12 , the ignition device 40 includes a conductive row 44, one end of the conductive row 44 is lapped and fixed to the inductor coil 30 and is conducted with the inductor coil 30, and the other end of the conductive row 44 is parallel and spaced from the side wall of the Faraday cylinder 10 to form an equivalent capacitor.

[0056] It should be noted that in this embodiment, one end of the busbar 44 is lapped and fixed to the inductance coil 30 and conducts with it, which can ensure that the ignition device 40 efficiently couples high-frequency high voltage from the inductance coil 30. A resistor 43 can also be provided on the busbar 44. Compared with the indirect power-taking method in other embodiments, it reduces the energy loss and signal interference in the intermediate links, enabling more voltage to be transmitted to the ignition device 40, providing sufficient energy support for forming a high electric field strength in the plasma cavity subsequently, and improving the success rate and speed of ignition. The other end of the busbar 44 is parallel and spaced from the side wall of the Faraday cylinder 10, so only the second equivalent capacitance is formed. The second equivalent capacitance can store and release charges. When the voltage on the inductance coil 30 changes, the second equivalent capacitance can correspondingly charge and discharge, thereby forming a changing electric field in the plasma cavity.

[0057] In a possible implementation manner, the capacitance value C of the equivalent capacitance satisfies C = εS / 4πkd; where ε is the dielectric constant; the facing area between the ignition device 40 and the inductance coil 30 and the facing area between the ignition device 40 and the Faraday cylinder 10 are both S; the distance between the ignition device 40 and the inductance coil 30 and the distance between the ignition device 40 and the Faraday cylinder 10 are both d; k is the electrostatic constant.

[0058] Furthermore, the capacitance values of the first equivalent capacitance and the second equivalent capacitance also satisfy C = εS / 4πkd; ε is the dielectric constant; the facing area between the first straight section 421 and the inductance coil 30 and the facing area between the second straight section 422 and the Faraday cylinder 10 are both S; the distance between the first straight section 421 and the inductance coil 30 and the distance between the second straight section 422 and the Faraday cylinder 10 are both d; k is the electrostatic constant.

[0059] It should be noted that both the first equivalent capacitance and the second equivalent capacitance can be calculated to obtain the capacitance. For example, when calculating the first equivalent capacitance, ε is a constant, which can be the dielectric constant of polytetrafluoroethylene and can be 2.1, S is the facing area between the first straight section 421 and the inductance coil 30 and can be 10 cm², d is the distance between the first straight section 421 and the inductance coil 30 and can be 2 cm, and k is the electrostatic constant, which can usually be 9.0×10⁹ N·m² / C². After calculation, the first equivalent capacitance is about 1 pF. Through the equivalent capacitance calculation formula, technicians can accurately calculate the capacitance value according to actual needs. When igniting in a plasma asher with different operating frequencies, they can select appropriate dielectric materials and adjust the positional relationship between the conductive strip 42 and the inductance coil 30 to achieve the purpose of optimizing the performance of the ignition device 40 and improving the ignition efficiency and stability.

[0060] In some embodiments, please refer to Figure 1, the plasma asher further includes a vacuum capacitor 50 and a matcher 60; wherein, the matcher 60 is electrically connected to the inductance coil 30 and is used for outputting a high-voltage high-frequency signal, and the vacuum capacitor 50 is connected in series between the matcher 60 and the inductance coil 30.

[0061] It should be noted that the vacuum capacitor 50 can store electric energy and can deliver the stored energy to the inductance coil 30 to provide sufficient energy for gas ionization. At the same time, it can eliminate peaks and valleys of the electric field, so as to form a stable and uniform electric field environment between the conductive strip 42 and the Faraday cylinder 10, enabling the electric field energy to act on the gas in the plasma cavity more concentratedly and effectively. The vacuum capacitor 50 can also play a role in isolating DC components and protecting the circuit, preventing the DC components in the circuit from entering the plasma cavity and avoiding adverse effects of DC current on the plasma. The matcher 60 can adjust the frequency and power of the high-voltage high-frequency signal input to the vacuum capacitor 50, and can always make the state of the plasma match the requirements of the ashing process.

[0062] In a second aspect, an ignition method based on a plasma asher according to an embodiment of the present invention further includes:

[0063] Output a high-voltage high-frequency signal to the inductance coil 30 so that a target voltage is obtained on the inductance coil 30;

[0064] Take power from the inductance coil 30 by using the conductive strip 42 or the conductive bus bar 44 and charge the equivalent capacitor;

[0065] The equivalent capacitor releases high-voltage electricity into the plasma cavity so that a high electric field strength is formed between the conductive strip 42 or the conductive bus bar 44 and the top wall of the Faraday cylinder 10;

[0066] The gas in the plasma cavity is ionized under the high electric field strength to complete ignition;

[0067] After ignition is completed, continue to output a high-voltage high-frequency signal to the inductance coil 30 so that the inductance coil 30 generates a periodically changing current;

[0068] An electric field for continuously ionizing gas to obtain plasma is formed inside the plasma cavity based on the periodically changing current;

[0069] The density of the plasma in the plasma cavity gradually increases based on the continuous ionization process until the plasma conducts the conductive strip 42 or the conductive bus bar 44 and the grounded top wall of the Faraday cylinder 10.

[0070] It should be noted that by outputting a high-voltage high-frequency signal to the inductance coil 30, the inductance coil 30 can quickly obtain the target voltage. Then, the conductive strip 42 or the conductive busbar 44 is used to couple a high-frequency high-voltage signal from the inductance coil 30 and charge the equivalent capacitor, efficiently transferring the energy to the periphery of the plasma cavity. Since an equivalent capacitor is formed between the conductive strip 42 or the conductive busbar 44 and the inductance coil 30 and the Faraday cylinder 10, the voltage can be accurately acquired and stored, providing a sufficient and stable energy source for the subsequent formation of a high electric field strength and improving the success rate of ignition. After ignition, a high-voltage high-frequency signal continues to be output to the inductance coil 30. After ignition, a periodically changing current is generated in the inductance coil 30, and then an electromagnetic field for continuously ionizing the gas is formed inside the plasma cavity. This continuous electromagnetic field can ensure that the gas in the plasma cavity is continuously ionized, maintaining the stable generation of the plasma. The stable plasma is crucial for the normal operation of the plasma desoldering machine, ensuring the continuity and stability of the desoldering process and improving the desoldering quality and efficiency. Moreover, the continuously changing voltage and current on the inductance coil 30 after ignition can generate a high-energy electromagnetic field to quickly and continuously ionize the gas, and an avalanche effect can occur, thereby generating a high-density plasma. The continuously generated plasma reduces the impedance between the ignition device 40 and the top wall of the Faraday cylinder 10, enabling the ignition device 40 to achieve automatic grounding, avoiding potential safety hazards such as electrical breakdown and discharge caused by high-voltage accumulation, and improving the safety of equipment use.

[0071] The beneficial effects of the ignition method provided by the present invention are as follows: Compared with the prior art, the conductive strip 42 or the conductive busbar 44 takes power from the inductance coil 30 and charges the equivalent capacitor. The equivalent capacitor enters the interior of the Faraday cylinder 10 and releases high voltage into the plasma cavity to form a high electric field strength between the conductive strip 42 or the conductive busbar 44 and the top wall of the Faraday cylinder 10, ionizing the gas in this area to achieve ignition. The conductive strip 42 extends into the interior of the Faraday cylinder 10 for ignition, so that the ignition process is not affected by the shielding of the electric field by the Faraday cylinder 10, enabling rapid ignition of the plasma desoldering machine and improving work efficiency; after successful ignition, the plasma density inside the plasma cavity gradually increases, and the impedance between the conductive strip 42 or the conductive busbar 44 and the top wall of the Faraday cylinder 10 decreases until the conductive strip 42 is in conduction with the top wall of the Faraday cylinder 10, enabling automatic grounding of the ignition device 40 and guiding the voltage in the ignition device 40 to the ground, avoiding high-voltage accumulation when the high-voltage high-frequency signal is input in the next cycle and improving the safety of equipment use. The ignition device 40 is equivalent to an automatic plasma switch. In the initial state without plasma, the ignition device 40 obtains high voltage and achieves ignition; when the plasma is generated, the ignition device 40 is grounded and the ignition device 40 can be automatically turned off, avoiding affecting the normal operation of the desoldering machine. There is no need to add an additional control system for the ignition device 40, the operation is convenient, the overall structure of the equipment is simplified, and the cost of equipment upgrade and transformation is saved.

[0072] Since the equivalent capacitance can store and release energy by itself and make the energy more concentrated, the input power of the high-voltage high-frequency signal can complete ignition at 200 - 400 W. Compared with the ignition device in the conventional technology that requires a radio frequency signal of more than 600 W to ignite, the energy consumption is greatly reduced. On the premise of ensuring successful ignition, a lower power input can reduce the operation cost of the device and improve the energy utilization rate. The ignition time of the ignition device 40 is less than 100 milliseconds, which can improve the working efficiency of the debonder and avoid problems such as device startup delay or instability caused by too long ignition time. In the actual production process, stable and rapid ignition can ensure the coherence of the production rhythm, reduce the risk of production interruption, and improve the stability of production efficiency and product quality.

[0073] After ignition, different debonding processes have different requirements for the density and activity of the plasma. By adjusting the frequency and power of the high-voltage high-frequency signal of the input electrode through the matcher 60, the state of the plasma can always be matched with the requirements of the debonding process. When removing thick or difficult-to-remove photoresist, a plasma with a higher density and activity is required. At this time, the power of the signal can be appropriately increased and the frequency can be adjusted to increase the generation amount and activity of the plasma; while in the case of fine debonding operations, a plasma with a lower density but more stable is required, and then the power can be reduced and the frequency can be optimized to improve the debonding accuracy and quality and reduce the damage to the underlying material.

[0074] Taking the time from inputting the high-voltage high-frequency signal to the grounding of the ignition device 40 as a working cycle, real-time monitoring and recording of the working state of the ignition device 40 throughout the working cycle can promptly detect abnormal situations during the operation of the device. If situations such as a sudden increase in ignition time and unstable obtained voltage are monitored, it indicates that a certain component of the ignition device 40 has a problem, such as a decrease in capacitance performance and a change in resistance value. By recording these abnormal data in real time, maintenance personnel can quickly locate the fault point and repair it before the fault further deteriorates, avoiding equipment shutdown caused by the fault and ensuring the continuous and stable operation of the debonder. Through the analysis of a large amount of working cycle data, the performance of the ignition device 40 under different working conditions can be deeply understood. Analyzing data such as the ignition success rate and ignition time under different input signal powers and frequencies helps to determine the optimal range of working parameters and provides a basis for the design improvement of the ignition device 40. At the same time, deficiencies in the process can also be found, such as whether the assembly process affects the performance of the device, and then the process can be optimized to improve the overall performance of the ignition device 40.

[0075] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. Plasma degumming machine, characterized in that: The invention comprises a Faraday cup, a quartz cup, an inductor coil and an ignition device, wherein the top wall of the Faraday cup is grounded; the quartz cup is arranged in the Faraday cup so that a plasma cavity is formed inside the Faraday cup; the inductor coil is wound around the outer circumference of the Faraday cup and is used to receive high-voltage and high-frequency signals; the ignition device is connected to the inductor coil and forms an equivalent capacitor with the inductor coil and / or the Faraday cup; The equivalent capacitor is used to couple high frequency and high voltage from the inductor coil, and a high field strength for ionizing gas is formed inside the plasma chamber based on the discharge of the equivalent capacitor, and the ignition device turns on the top wall and / or side wall of the Faraday cage as the density of the plasma obtained by continuous ionization of the gas in the plasma chamber increases.

2. The plasma degumming machine according to claim 1, characterized in that: The ignition device includes an insulating card and a conductive belt, wherein the insulating card is clamped on the inductor coil, and the conductive belt is arranged on the insulating card, and the conductive belt extends into the Faraday cup and contacts the side wall of the quartz cup; wherein the conductive belt, the inductor coil, and the Faraday cup form the equivalent capacitor.

3. The plasma degumming machine according to claim 2, characterized in that: The conductive strip includes a first straight section and a second straight section; the first straight section is spaced parallel to the inductor to form a first equivalent capacitor; the second straight section is spaced parallel to the side wall of the Faraday cage to form a second equivalent capacitor.

4. The plasma degumming machine according to claim 3, characterized in that: The first straight section is overlapped and fixed on the upper surface of the insulating clamp and is spaced apart from the inductor coil in upper and lower directions. The second straight section is bent downward or upward at the end of the first straight section close to the Faraday cage.

5. The plasma degumming machine according to claim 3, characterized in that: The conductive tape further includes a third straight section; wherein two ends of the third straight section are respectively vertically connected to the first straight section and the second straight section; the first straight section is vertically mounted on the side wall of the insulating card facing the Faraday cage and is horizontally spaced from the inductor coil; and the second straight section is located between the first straight section and the side wall of the Faraday cage.

6. The plasma degumming machine according to claim 5, characterized in that: The third straight section is connected in series with a resistor.

7. The plasma degumming machine according to claim 1, characterized in that: The ignition device comprises a conductive bar, one end of which is overlapped and fixed to the inductor and is in conduction with the inductor, and the other end of which is parallel and spaced from the side wall of the Faraday cage to form the equivalent capacitor.

8. The plasma degumming machine according to claim 1, characterized in that: The capacitance value C of the equivalent capacitor satisfies C=εS / 4πkd; wherein ε is the electrolyte constant; the facing area of ​​the ignition device and the inductance coil, and the facing area of ​​the ignition device and the Faraday cup are both S; the distance between the ignition device and the inductance coil, and the distance between the ignition device and the Faraday cup are both d; and k is the electrostatic force constant.

9. The plasma degumming machine according to any one of claims 1 to 8, characterized in that: The plasma degumming machine also includes a vacuum capacitor and a matcher; wherein the matcher is electrically connected to the inductor coil and is used to output a high-voltage and high-frequency signal, and the vacuum capacitor is connected in series between the matcher and the inductor coil.

10. The ignition method of a plasma degumming machine according to any one of claims 1 to 9, characterized in that: include: Outputting a high-voltage and high-frequency signal to the inductor so as to obtain a target voltage on the inductor; Using a conductive tape or a conductive bar to draw power from the inductor and charge the equivalent capacitor; The equivalent capacitor releases high voltage electricity into the plasma chamber to form a high field strength between the conductive strip or the conductive row and the top wall of the Faraday cage; The gas in the plasma chamber is ionized under the high field strength to complete ignition; After the ignition is completed, the high-voltage and high-frequency signal continues to be output to the inductor coil, so that the inductor coil generates a periodically changing current; An electric field for continuously ionizing gas to obtain plasma is formed inside the plasma chamber based on the periodically changing current; The density of the plasma in the plasma chamber gradually increases based on a continuous ionization process until the plasma connects the conductive tape or the conductive row to the grounded top wall of the Faraday cage.

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