Arc suppression and energy absorption circuit of coating power supply

Abstract

The utility model relates to the technical field of magnetron sputtering power supplies, in particular to an electric arc suppression and energy absorption circuit of a coating power supply, which comprises a power supply unit, a switch piece and a follow current branch, the switch piece and the follow current branch are connected in parallel between the output end of the power supply unit and the output end of the power supply, and the output end of the power supply is connected with a load through a series-connection line inductor group. The switching element is connected in parallel between the output positive electrode and the output negative electrode of the power supply unit, so that power supply output is quickly cut off when electric arc occurs; the follow current branch is connected in parallel between the output end of the power supply unit and the output end of the power supply, the follow current branch and the line inductor group form a follow current loop, follow current is carried out on the line inductor, high-voltage impact caused by the line inductor is prevented from damaging power devices in the power supply, the reliability of the power supply is improved, and in the follow current process, a resistor absorbs and consumes energy in the circuit, arc extinguishing is fast, and the service life of the power supply is prolonged. And the safety and stability of the power supply are ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of magnetron sputtering power supplies, and particularly relates to an arc suppression and energy absorption circuit for a coating power supply. Background Art

[0002] In the process of vacuum magnetron sputtering coating, due to poor quality of coating materials and unreasonable setting of sputtering power, arcing often occurs in the vacuum chamber where coating is carried out. When an arc appears, the current in the circuit increases abnormally, often several times the normal working current, and the power supply is close to a short - circuit state, seriously affecting the safety of the components in the internal circuit of the power supply. With the continuous development of the coating process, higher requirements are put forward for the arc extinguishing speed and whether the arc extinguishing is complete.

[0003] Currently, energy storage elements are usually added to the power supply circuit to absorb the arc energy and suppress the arc. For example, a capacitor element is added inside the power supply, and the capacitor is charged to absorb the arc energy in the circuit, or a large - capacity inductor is connected in series in the power supply circuit to absorb energy to suppress the impact of the arc current on the power supply. However, at the moment when the power supply is disconnected, the capacitor or inductor releases energy, generating a stronger arc light, threatening the safety of the power supply, making the arcing phenomenon more frequent, and the coating can hardly be carried out normally, and the coating quality is greatly affected.

[0004] Based on the problems in the prior art, the utility model provides an arc suppression and energy absorption circuit for a coating power supply. Summary of the Utility Model

[0005] The purpose of the utility model is to provide an arc suppression and energy absorption circuit for a coating power supply to solve the technical problem that in the prior art, energy is absorbed by a capacitor or an inductor to suppress the arc thoroughly.

[0006] The technical solution of the utility model is: an arc suppression and energy absorption circuit for a coating power supply, including a power supply unit. A switch element and a free - wheeling branch are connected in parallel between the output end of the power supply unit and the power output end. The power output end is connected to a load through a series line inductor group. When the switch element is in the off state, the power supply unit outputs power to the load through the line inductor group, and the load works for coating. When the switch element is in the on state, the power supply unit does not supply power, the load does not work, and the free - wheeling branch works to form a free - wheeling loop and synchronously absorb the arc energy in the free - wheeling loop.

[0007] Preferably, the free - wheeling branch includes a diode, a capacitor, and an energy - consuming element;

[0008] The diode and the energy - consuming element are connected in parallel, and a common end of the parallel connection is connected in series with one end of the capacitor, and the other end of the capacitor is connected between the positive poles of the power supply unit and the power output end.

[0009] Preferably, the energy-consuming element is a resistor.

[0010] Preferably, the inductance group includes a first inductance and a second inductance, and the first inductance and the second inductance are respectively connected in series to the positive and negative electrodes of the power supply output terminal.

[0011] Preferably, the switching element is one of a power switching tube and a mechanical switching element.

[0012] Compared with the prior art, the advantages of the present utility model are as follows:

[0013] By connecting a switching element in parallel between the positive and negative electrodes of the output of the power supply unit, when an arc is detected, the power supply output is quickly turned off; a freewheeling branch is connected in parallel between the output terminal of the power supply unit and the power output terminal. The freewheeling branch and the inductance group form a freewheeling loop to freewheel the inductance, avoiding high-voltage impact damage to the power devices inside the power supply caused by the inductance, improving the reliability of the power supply, and during the freewheeling process, the resistor absorbs and consumes the energy in the circuit to quickly extinguish the arc, ensuring the safety and stability of the power supply. Description of the Drawings

[0014] The following further describes the present utility model in conjunction with the drawings and embodiments:

[0015] Figure 1 It is a working schematic diagram of the arc suppression and energy absorption circuit of the present utility model in the normal coating state;

[0016] Figure 2 It is a working schematic diagram of the arc suppression and energy absorption circuit of the present utility model in the arc extinguishing state when an arc occurs;

[0017] 1. Switching element; 2. Freewheeling branch; 3. Power supply unit; 4. Inductance group; 5. Vacuum chamber. Detailed Embodiments

[0018] The following further elaborates on the content of the present utility model in conjunction with specific embodiments:

[0019] For ease of understanding, first, the application scenario of the present utility model is described. This application is used for the internal circuit of a coating power supply. The specific circuit structure refers to the attached Figure 1 , with the vacuum chamber 5 as the load, coating the metal substrate inside the vacuum chamber 5, and the power supply circuit providing electrical energy. Since arcing may occur during the coating process, the current in the circuit is several times higher than the normal working current, and the power supply output is close to a short-circuit state, threatening the safety of the power supply. Therefore, when an arc is detected, the output needs to be quickly turned off, and the arc energy needs to be suppressed or absorbed to avoid abnormal increase in the circuit current caused by the arc and protect the safety of the power supply.

[0020] As Figure 1As shown in the figure, an arc suppression and energy absorption circuit for a coating power supply includes a power supply unit 3.

[0021] An absorption circuit is provided between the output end of the power supply unit 3 and the power supply output end. The power supply output end is connected to the load through a series inductor group 4. The inductors in the inductor group 4 filter the output of the power supply part, removing high frequencies and retaining low frequencies.

[0022] The absorption circuit includes a switching device 1 and a freewheeling branch 2 that are respectively connected in parallel between the output end of the power supply unit 3 and the power supply output end.

[0023] In practical applications, there may be switches for controlling the output inside the power supply unit 3. For the convenience of description, in this embodiment, it is default that the power supply unit 3 is in a normal power supply state, and the on-off of the power supply circuit is controlled by the switching device 1.

[0024] The switching device is one of a power switch tube and a mechanical switching device.

[0025] The switching device 1 is connected to the control system and is controlled to be turned on or off according to the coating state in the vacuum chamber 5. The control system can be a hardware circuit (such as an analog circuit), or a software processor, such as a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), or an MCU (Micro Control Unit).

[0026] Specifically, the freewheeling branch 2 adopts an RCD circuit, including a diode, a capacitor, and an energy-consuming element. The energy-consuming element adopts a resistor R.

[0027] The diode D and the resistor R are connected in parallel, and a common end of the parallel connection is connected in series with one end of the capacitor C. The other common end of the parallel connection of the diode D and the energy-consuming element is connected between the negative output of the power supply unit 3 and the negative power supply output. The other end of the capacitor C is connected between the positive output of the power supply unit 3 and the positive power supply output.

[0028] The inductor group 4 includes a first inductor L1 and a second inductor L2. The first inductor L1 and the second inductor L2 are respectively connected in series to the positive and negative power supply outputs.

[0029] In the normal operation state, the switching device 1 is turned off. Referring to the appendix Figure 1 , the output of the power supply unit 3 supplies power to the load through the inductor group 4, and the load works for coating; after the capacitor C is quickly charged in a short time, the entire freewheeling branch 2 is disconnected and does not work.

[0030] When an arc occurs, the switching device 1 is turned on, quickly turning off the output of the power supply unit 3. The load does not work, and the freewheeling branch 2 starts to work, forming two freewheeling circuits on both sides of the switching device 1.

[0031] As shown in the appendix Figure 2 , when the power supply circuit is in the arc extinguishing working state:

[0032] When the switching element 1 is turned off instantaneously, the inductance group 4 absorbs and suppresses the arc energy. The capacitor C in the freewheeling branch 2 releases the stored energy. Part of the energy continues to flow through the first inductor L1 and the second inductor L2, keeping the current in the first inductor L1 and the second inductor L2 changing smoothly, avoiding the high-voltage impact caused by the inductance from damaging the power devices inside the power supply, and improving the reliability of the power supply; the other part is transmitted to the resistor R through the left switching element 1 to form a loop, and the energy in the loop on both sides of the capacitor is consumed and absorbed by the resistor.

[0033] When an arc is detected by the output voltage and current, and after the arc energy in the circuit is absorbed completely, the switching element 1 is turned off, and the power supply circuit resumes its normal operating state to continue coating.

[0034] During the coating process, whether an arc occurs and whether the arc energy in the circuit is absorbed completely are both realized based on the detection of the circuit, depending on the specific situation.

[0035] For example, when the current-voltage curve during the coating process in the vacuum chamber 5 is detected, and its voltage curve drops while the current rises, it is determined that an arc has occurred in the circuit, and the power supply needs to be disconnected to suppress and absorb the arc energy.

[0036] When it is detected that the inside of the vacuum chamber 5 is rapidly cooled (corresponding to the voltage and current of the equivalent load inside the chamber being reduced to 0), it is determined that the circuit energy has been absorbed completely, and the power supply is restarted again to resume the normal coating state.

[0037] The power supply unit 3 adopts a combination of a transformer and a diode rectifier circuit. Electrical isolation is carried out through an isolation transformer. The secondary side of the transformer is connected to a rectifier diode for rectification to output direct current.

[0038] Compared with the prior art, the present embodiment has the following characteristics:

[0039] By connecting a switching element in parallel between the positive and negative outputs of the power supply unit 3, when an arc is detected, the power supply output is quickly turned off; a freewheeling branch 1 is connected in parallel between the output end of the power supply unit and the output end of the power supply. The freewheeling branch 1 and the inductance group form a freewheeling loop to freewheel the inductance, avoiding the high-voltage impact caused by the inductance from damaging the power devices inside the power supply, improving the reliability of the power supply, and during the freewheeling process, the resistor absorbs and consumes the energy in the circuit to quickly extinguish the arc, ensuring the safety and stability of the power supply.

[0040] The above embodiments are only used to illustrate the technical concept and characteristics of the present utility model. The purpose is to enable those who are familiar with this technology to understand the content of the present utility model and implement it accordingly, and it should not be used to limit the protection scope of the present utility model. For those skilled in the art, it is obvious that the present utility model is not limited to the details of the above exemplary embodiments, and without departing from the spirit or basic characteristics of the present utility model, the present utility model can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present utility model is defined by the appended claims rather than the above description. Therefore, it is intended to embrace all changes that fall within the meaning and scope of the equivalent elements of the claims in the present utility model.

Claims

1. An arc suppression and energy absorption circuit for a coating power supply, characterized in that: It comprises a power supply unit, wherein a switch element and a freewheeling branch are connected in parallel between an output end of the power supply unit and an output end of a power supply, and the output end of the power supply is connected to a load via a series line inductance group; When the switch is turned off, the power supply unit outputs power to the load via the line inductance group, and the load works to perform coating; When the switch is in the on state, the power supply unit does not supply power, the load does not work, and the freewheeling branch works to form a freewheeling loop and synchronously absorbs arc energy in the freewheeling loop.

2. The arc suppression and energy absorption circuit of a coating power supply according to claim 1, characterized in that: The freewheeling branch includes a diode, a capacitor and an energy-consuming element; The diode and the energy-consuming element are connected in parallel, and a common end of the parallel connection is connected in series with one end of the capacitor, and the other end of the capacitor is connected between the power supply unit and the positive electrode of the output end of the power supply.

3. The arc suppression and energy absorption circuit of a coating power supply according to claim 2, characterized in that: The energy consumption element is a resistor.

4. The arc suppression and energy absorption circuit of a coating power supply according to claim 1, characterized in that: The line inductor group includes a first line inductor and a second line inductor, and the first line inductor and the second line inductor are respectively connected in series to the positive electrode and the negative electrode of the power output terminal.

5. The arc suppression and energy absorption circuit of a coating power supply according to claim 1, characterized in that: The switch element is a power switch tube or a mechanical switch element.

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