Protection circuit based on magnetron sputtering power supply system
By designing the protection circuit for the magnetron sputtering power supply system, problems such as charge accumulation, short-circuit impact, and excessive temperature were solved, achieving multiple protections for the power supply and ensuring the safe operation and stability of the equipment.
Patent Information
- Application Number
- CN202423058565.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-11
- Publication Date
- 2025-12-02
- Estimated Expiration
- 2034-12-11
AI Technical Summary
Magnetron sputtering power supplies are prone to charge accumulation and arcing during thin film deposition, lacking effective detection and suppression strategies, which can lead to power supply damage. The modules are also susceptible to short-circuit impacts and overheating during operation, and lack protection circuits.
A protection circuit was designed, which includes an output current detection and overcurrent protection circuit, a temperature protection circuit, and a short-circuit surge protection circuit. It utilizes components such as Hall sensors, IGBTs, single-phase rectifier bridges, and output filter circuits to achieve multiple protections for the power supply.
It effectively prevents power supply damage under conditions such as overcurrent, overtemperature, and short circuit impact, ensuring the normal operation and safety of equipment and improving the reliability and stability of the power supply.
Smart Images
Figure CN223625760U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to a power supply technology, and more particularly to a protection circuit based on a magnetron sputtering power supply system. Background Technology
[0002] Magnetron sputtering, as a coating process, is widely used in many fields such as energy, materials, and environment due to its superior performance. With the expansion of its application areas, magnetron sputtering technology has gradually become a common method for manufacturing more products. However, due to inherent problems with the magnetron sputtering power supplies used in these fields—poor constant current characteristics and susceptibility to arcing—defects in the film layer are easily caused, and in severe cases, the power supply may even be damaged, making it unsuitable for demanding coating processes.
[0003] Existing design schemes such as Figure 1 As shown, the main circuit of the system from input to output includes: input EMC filter, Vienna PFC circuit, bus support capacitor, isolation DC-DC1 and isolation DC-DC2.
[0004] The functions of each part of the system are as follows:
[0005] Input EMC Filter: Even a well-designed product with proper shielding and grounding can still experience conducted interference emissions or conduction-induced interference entering the product. When conducted emissions (CE) fail to meet standards, radiated emissions (RE) may also fail due to the antenna effect. The function of this filter is to filter out interference signals to meet the CE and CS (conducted susceptibility) limits specified in EMC standards.
[0006] Vienna PFC Circuit: The three-level, three-phase VIENNA structure has the advantages of fewer components and no dead time required for each phase drive signal, making it widely used in PFC of high-power power supplies. The high control frequency of the VIENNA rectifier reduces the size of the inductor and transformer, significantly shrinking the charger's size and increasing power density. The two MOSFETs in each phase are anti-connected, avoiding the shoot-through phenomenon seen in PWM rectifiers, eliminating the need to consider dead time, and making the drive circuit relatively easy to implement. However, Vienna must consider the balance of the DC-side neutral point potential, as fluctuations in the neutral point voltage increase the harmonic components of the injected grid current. Severe deviations in the neutral point voltage can cause damage to switching devices and DC-side current due to excessive voltage.
[0007] Busbar support capacitors are used for energy storage and filtering. They smooth the input power supply voltage, reducing the AC component, thus minimizing interference from the upstream power supply to the downstream control system and improving its stability.
[0008] Isolation DC-DC1 circuit: used to generate sputtering shock voltage of 1500V, with a maximum discharge time of 8ms. It mainly relies on capacitors for instantaneous power storage and output. During the output process, the IGBT can be turned on to deliver high voltage to the outside, while DC-DC2 stops outputting due to the clamping of the diode.
[0009] Isolated DC-DC2 circuit: used to generate a high power output of 20kW. The output is required to be used in parallel and requires automatic current sharing in software or hardware.
[0010] Disadvantages of existing technology:
[0011] 1. During the thin film deposition process, charge accumulation and arcing are unavoidable in magnetron sputtering power supplies. The lack of arc detection and suppression strategies can damage the power supply in severe cases.
[0012] 2. The module is directly subjected to short-circuit impacts during operation. Without this protection circuit, the module will be directly damaged.
[0013] 3. The module lacks a temperature protection circuit. If the device continuously generates heat during operation, the circuit cannot detect it and provide protection measures, which may cause the device to exceed its operating temperature range, and in severe cases, it may lead to the device exploding.
[0014] In view of the above, this utility model is hereby proposed. Utility Model Content
[0015] The purpose of this invention is to provide a protection circuit based on a magnetron sputtering power supply system to solve the aforementioned technical problems in the prior art.
[0016] The objective of this utility model is achieved through the following technical solution:
[0017] The protection circuit of this utility model based on a magnetron sputtering power supply system includes:
[0018] Output current detection and overcurrent protection circuit, temperature protection circuit, short circuit impact protection circuit;
[0019] The output current monitoring and overcurrent protection circuit includes a Hall sensor for detecting the output current, a signal conditioning and amplification unit, an AD data conversion unit, and a comparison unit.
[0020] The output of the comparison unit is connected to a software-driven control unit or a hardware overcurrent control unit for the PWM signal.
[0021] The Hall sensor is equipped with a hardware automatic latching protection state unit.
[0022] The temperature protection circuit includes an IGBT, a single-phase rectifier bridge, and KSD301-80 degree switch contacts.
[0023] The short-circuit impact protection circuit is equipped with an output filter circuit.
[0024] Compared with the prior art, the protection circuit based on the magnetron sputtering power supply system provided by this utility model can provide various protections for the power supply, prevent problems such as overcurrent, overtemperature, and short circuit impact during power supply operation, and avoid power supply damage. Attached Figure Description
[0025] Figure 1 Block diagram for existing sputtering power supply design;
[0026] Figure 2 This is a schematic diagram of sputtering output and steady-state output according to an embodiment of the present invention;
[0027] Figure 3 This is a schematic diagram of the voltage and current loop cutoff control in an embodiment of the present invention;
[0028] Figure 4 This is a schematic diagram of a Hall effect current measurement according to an embodiment of the present invention;
[0029] Figure 5 This is a schematic diagram of a voltage and current hardware protection comparison scheme according to an embodiment of the present invention;
[0030] Figure 6 This is a schematic diagram of the voltage and current hardware protection interlocking scheme in an embodiment of this utility model;
[0031] Figure 7 This is a schematic diagram of the dual-power sputtering output simulation circuit of an embodiment of this utility model;
[0032] Figure 8 This is a schematic diagram of the simulation results of dual-power sputtering output in an embodiment of this utility model. Detailed Implementation
[0033] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments, which do not constitute a limitation on the present utility model. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.
[0034] First, the following explanations are provided for the terms that may be used in this article:
[0035] The term "and / or" means that either or both can be achieved simultaneously. For example, X and / or Y means that it includes both "X" or "Y" as well as the three cases of "X and Y".
[0036] The terms “including,” “comprising,” “containing,” “having,” or other similar semantic descriptions should be interpreted as non-exclusive inclusion. For example, “including a technical feature element (such as raw material, component, ingredient, carrier, dosage form, material, size, part, component, mechanism, device, step, process, method, reaction conditions, processing conditions, parameter, algorithm, signal, data, product or article of manufacture, etc.)” should be interpreted as including not only the expressly listed technical feature element, but also other technical feature elements that are not expressly listed and are well-known in the art.
[0037] The term "composed of" excludes any technical features not expressly listed. When used in a claim, it closes the claim to exclude all technical features other than those expressly listed, except for associated conventional impurities. If the term appears only in a clause of a claim, it limits the claim to the elements expressly listed in that clause; elements recited in other clauses are not excluded from the overall claim.
[0038] The contents not described in detail in the embodiments of this utility model are existing technologies known to those skilled in the art. Where specific conditions are not specified in the embodiments of this utility model, they shall be performed according to conventional conditions in the art or conditions recommended by the manufacturer. Reagents or instruments used in the embodiments of this utility model whose manufacturers are not specified are all conventional products that can be purchased commercially.
[0039] The protection circuit of this utility model based on a magnetron sputtering power supply system includes:
[0040] Output current detection and overcurrent protection circuit, temperature protection circuit, short circuit impact protection circuit;
[0041] The output current monitoring and overcurrent protection circuit includes a Hall sensor for detecting the output current, a signal conditioning and amplification unit, an AD data conversion unit, and a comparison unit.
[0042] The output of the comparison unit is connected to a software-driven control unit or a hardware overcurrent control unit for the PWM signal.
[0043] The Hall sensor is equipped with a hardware automatic latching protection state unit.
[0044] The temperature protection circuit includes an IGBT, a single-phase rectifier bridge, and KSD301-80 degree switch contacts.
[0045] The short-circuit impact protection circuit is equipped with an output filter circuit.
[0046] In summary, the protection circuit based on the magnetron sputtering power supply system of this utility model embodiment can provide various protections for the power supply, prevent problems such as overcurrent, overtemperature, and short circuit impact during power supply operation, and avoid power supply damage.
[0047] To more clearly demonstrate the technical solution and effects provided by this utility model, the following detailed description of the embodiments of this utility model is provided with reference to specific examples.
[0048] Example 1
[0049] like Figures 2 to 8 As shown:
[0050] The protection scheme adopted by this utility model is as follows:
[0051] 1. Output current detection and overcurrent protection
[0052] Overcurrent protection includes multiple protection schemes. One is to disconnect the circuit using a fuse; another is software-driven protection, where the software stops the PWM signal output based on the fault condition; and a third is hardware-driven overcurrent protection that stops the PWM signal. Hardware protection is fast and has a high threshold; software protection is slow and has a low threshold.
[0053] like Figure 4 As shown, the input current is detected by Hall effect, the signal is conditioned and amplified by the controller board, and then the AD data is converted and compared with the protection setting value. When an overcurrent occurs, the PWM output is stopped.
[0054] The module fault protection circuit employs different protection measures for DC output side faults and AC input side faults. When an overcurrent fault occurs on the module's DC output side, only a fault signal needs to be output to block the trigger pulse; the input contactor does not need to be disconnected. The AC input contactor only needs to be disconnected when an overvoltage or overcurrent fault occurs on the module's AC input side. After power is cut off to the module, the switching power supply module automatically releases the stored energy on its energy storage capacitor through a leakage circuit within a short time to ensure that the capacitor voltage does not become excessive. The leakage resistor has a resistance of 13.9kΩ, ensuring that the stored energy on the module is automatically released within less than 100 seconds.
[0055] The overcurrent detection threshold of the power module can be adjusted and set on the screen as needed. The threshold value can be seen on the screen. When the detection circuit detects an overcurrent, it transmits the overcurrent fault to the control and protection circuit. At the same time, it can also latch the fault signal for a period of time through the dual monostable circuit. The fault latching time can be set on the screen.
[0056] Hardware-based rapid protection is very common in variable load and high-voltage systems. Improving the detection speed, response speed, and execution speed of the protection function is crucial. Digital power supplies typically use analog-to-digital conversion for protection, but this method is limited by the ADC conversion time and the microcontroller's processing speed, resulting in poor reliability. This solution uses a high-performance Hall sensor with a current response time of less than 1µs; an operational amplifier chip with a bandwidth of over 10MHz; low RC constant filter capacitors; and a hardware-based automatic latching method for PWM latch-up stop, thus achieving PWM stop triggering within 10µs for protection.
[0057] See Figure 5 and Figure 6 .
[0058] 2. Temperature protection
[0059] Temperature protection includes protection for the IGBT and single-phase rectifier bridge, using the dry contact method of KSD301-80 degree switch contacts.
[0060] 3. Short-circuit impulse protection
[0061] The module can directly withstand short-circuit impacts. In the event of a direct short circuit, the hardware protection circuit can achieve a current shutdown time of less than 10μs. To ensure the power module can protect itself properly, it is equipped with an internal output filter circuit. Its function is to prevent the current from increasing too quickly when arcing occurs, providing a buffer time for the module's rapid protection.
[0062] Simulation results:
[0063] like Figure 7 and Figure 8 As shown.
[0064] The beneficial effects of this utility model's technical solution are:
[0065] The three-phase Vienna PFC correction circuit used in this technical solution, compared to traditional PFC circuits, features an inherent three-level switch, reducing inductor size requirements, lowering switching frequency losses, stress switching at half the output voltage, and low electromagnetic interference. It is crucial that the switching transistor withstands half the output voltage stress; the 480Vac power supply uses 800-1200V rated SiC MOSFETs, eliminating concerns about damage due to insufficient voltage margin.
[0066] Plasma arcing is unavoidable during magnetron sputtering. To prevent damage to the power supply caused by a sharp rise in current due to arcing, overcurrent protection is designed to avoid power supply damage caused by arcing. The protection circuit described in this article can protect the equipment from damage caused by abnormal voltage, current, and other conditions, ensuring the normal operation and safety of the equipment.
[0067] See Figure 2 and Figure 3
[0068] As can be seen, the voltage is high during sputtering output, diode D1 is reverse-biased and Q1 outputs directly; when Q1 is turned off, diode D1 conducts in the forward direction and can output energy normally. This system requires high output voltage accuracy, so diode D1 is selected as a low forward voltage drop diode with a withstand voltage of 1500V~2000V.
[0069] Arc control output: Digital power supply control typically includes current loops and voltage loops for single closed-loop control, peak current control, or average current control. The voltage loop enables stable voltage output, while the current loop limits the maximum output power and the system's second-order control response.
[0070] This system adopts the concept of voltage and current cutoff control. When the high voltage output current is too large, the current can be automatically limited. At the same time, under light load, the output voltage can be stabilized at the set voltage.
[0071] Key technical features of this utility model:
[0072] Output current monitoring and overcurrent protection;
[0073] Over-temperature protection;
[0074] Short-circuit impact protection.
[0075] The above description is merely a preferred embodiment of this utility model, but the scope of protection of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this utility model should be included within the scope of protection of this utility model. Therefore, the scope of protection of this utility model should be determined by the scope of the claims. The information disclosed in the background section is intended only to enhance the understanding of the overall background technology of this utility model and should not be construed as an admission or implication in any way that such information constitutes prior art known to those skilled in the art.
Claims
1. A protection circuit based on a magnetron sputtering power supply system, characterized in that, include: Output current detection and overcurrent protection circuit, temperature protection circuit, short circuit impact protection circuit; The output current monitoring and overcurrent protection circuit includes a Hall sensor for detecting the output current, a signal conditioning and amplification unit, an AD data conversion unit, and a comparison unit. The output of the comparison unit is connected to a software-driven control unit or a hardware overcurrent control unit for the PWM signal.
2. The protection circuit based on the magnetron sputtering power supply system according to claim 1, characterized in that, The Hall sensor is equipped with a hardware automatic latching protection state unit.
3. The protection circuit based on the magnetron sputtering power supply system according to claim 1, characterized in that, The temperature protection circuit includes an IGBT, a single-phase rectifier bridge, and KSD301-80 degree switch contacts.
4. The protection circuit based on the magnetron sputtering power supply system according to claim 1, 2, or 3, characterized in that, The short-circuit impact protection circuit is equipped with an output filter circuit.