A chip etching special power filter for electrical equipment

Abstract

The application discloses a kind of chip etching electrical equipment special power filter of semiconductor wafer processing technical field, including shell assembly, filter unit being set in the shell assembly inside, interface assembly being electrically connected with the filter unit, and, protection assembly;The shell assembly includes shell, side plate and end cover;The filter unit includes first differential mode capacitor, customization coil, second differential mode capacitor and common mode capacitor;The first differential mode capacitor, the customization coil, the second differential mode capacitor and the common mode capacitor are connected in series in sequence, and the ground end of the common mode capacitor is connected with the shell.This application realizes the efficient suppression of chip etching equipment power supply side wide frequency band electromagnetic interference, improves the stability, electromagnetic compatibility and operation reliability of etching equipment power supply system, completely matches the high-precision, continuous operation demand of chip etching.

Description

Technical Field

[0001] This invention relates to a power filter specifically designed for chip etching electrical equipment, belonging to the field of semiconductor wafer processing technology. Background Technology

[0002] Chip etching equipment is a core high-precision device in semiconductor wafer processing. Its etching precision reaches the nanometer level. During operation, the requirements for suppressing power supply ripple, noise, and electromagnetic interference (EMI) are much higher than those for ordinary industrial equipment. Even small fluctuations on the power supply side can cause the etching pattern to shift, the precision to decrease, or even cause the wafer to be scrapped or the core components of the equipment to be damaged.

[0003] In existing technologies, chip etching equipment mostly uses general-purpose power filters to suppress electromagnetic interference. These filters are designed for general industrial scenarios and can only filter out interference in a single frequency band. They cannot cover the wide-band electromagnetic interference (including ground coupling noise and high-frequency differential / common-mode interference) on both the power grid side and the equipment side of the chip etching equipment. The filtering depth is insufficient and it is difficult to meet the power purity requirements of nanoscale etching. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a dedicated power filter for chip etching electrical equipment. Through customized multi-stage filter circuit design, three-phase symmetrical structure optimization, dedicated interface and protection component configuration, it solves the problems of weak anti-interference ability, poor adaptability and insufficient safety of existing filters. It achieves efficient suppression of wide-band electromagnetic interference on the power supply side of chip etching equipment, improves the stability, electromagnetic compatibility and operational reliability of the etching equipment power system, and fully matches the high-precision and continuous operation requirements of chip etching.

[0005] To achieve the above objectives, the present invention is implemented using the following technical solution:

[0006] In a first aspect, the present invention provides a power filter for chip etching electrical equipment, comprising a housing assembly, a filter unit disposed inside the housing assembly, an interface assembly electrically connected to the filter unit, and a protection assembly;

[0007] The housing assembly includes an outer shell, side panels, and end caps;

[0008] The filtering unit includes a first differential-mode capacitor, a customized coil, a second differential-mode capacitor, and a common-mode capacitor; the first differential-mode capacitor, the customized coil, the second differential-mode capacitor, and the common-mode capacitor are connected in series, and the ground terminal of the common-mode capacitor is connected to the outer casing;

[0009] The interface component includes an input connector interface for connecting to an external power supply and an output lead interface for connecting to a chip etching device. The input connector interface is connected to the first differential-mode capacitor, and the output lead interface is connected to the second differential-mode capacitor and the common-mode capacitor.

[0010] The protective assembly includes a resistor discharge module connected in parallel with the second differential-mode capacitor and / or the common-mode capacitor, and a waterproof and dustproof gasket for sealing.

[0011] Furthermore, the customized coil includes at least one magnetic ring, an insulating layer wound around the magnetic ring, and multiple sets of windings symmetrically wound around the magnetic ring, with shock-absorbing pads provided between adjacent magnetic rings.

[0012] Furthermore, the first differential mode capacitor is composed of multiple safety capacitors connected in parallel, and its number matches the number of power supply phases of the chip etching equipment.

[0013] Furthermore, the second differential-mode capacitor and the common-mode capacitor are a composite capacitor unit formed by connecting a safety capacitor and a high-frequency capacitor in parallel.

[0014] Furthermore, it also includes a controllable impedance fine-tuning branch, which is connected in parallel before the grounding node of the second differential-mode capacitor and the common-mode capacitor; the controllable impedance fine-tuning branch includes an interference spectrum monitoring unit, a control unit, and an RC network controlled by a digital potentiometer; the interference spectrum monitoring unit is used to monitor the signal at the input of the filter and identify the main interference frequency, and the control unit is used to calculate the target resistance value and control the digital potentiometer to adjust to the target resistance value, so as to dynamically change the impedance of the controllable impedance fine-tuning branch.

[0015] Furthermore, the formula for calculating the target resistance value is as follows:

[0016]

[0017] In the formula: Rset is the target resistance value that the digital potentiometer needs to be set; fdisturb is the frequency of the most important interference signal monitored and identified in real time by the interference spectrum monitoring unit; Cadj is the capacitance value of the fixed capacitor in the parallel controllable impedance fine-tuning branch; Atarget is the suppression depth required by the system for the main interference frequency; f0 is the reference frequency of the filter; π is pi.

[0018] Furthermore, the outer casing and the side plate are made of galvanized steel sheet, and the outer casing has mounting holes for rigid connection with the chip etching equipment chassis.

[0019] Furthermore, the input connector interface includes an industrial-grade waterproof ferrule and a terminal housing; the output wire is a tin-plated copper wire.

[0020] Furthermore, the resistor discharge module in the protection assembly includes multiple resistors, each of which is connected in parallel with the corresponding second differential-mode capacitor or common-mode capacitor.

[0021] Furthermore, the waterproof and dustproof gasket is a silicone rubber gasket, which is installed in the splicing gap of the housing assembly and at the lead-out hole of the output wire.

[0022] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0023] Its beneficial effects are reflected in the following aspects, and all effects are directly generated by the technical solution:

[0024] I. A three-stage filtering circuit consisting of a differential-mode capacitor, a customized manganese-zinc magnetic ring coil, and a differential / common-mode composite capacitor is employed to achieve full coverage filtering of electromagnetic interference across a wide frequency band from 10kHz to 1GHz. This effectively suppresses differential-mode interference from the power grid side, common-mode interference from the equipment side, and ground-coupled noise, significantly improving the filtering depth compared to general-purpose filters. The high-permeability manganese-zinc magnetic ring and three-phase symmetrical winding design of the customized coil greatly enhance the common-mode / differential-mode rejection ratio. The differential-mode capacitor precisely filters out inter-phase interference, effectively avoiding the decrease in etching precision caused by electromagnetic interference and ensuring the stability of the nanoscale etching process.

[0025] 2. The interface components adopt a dedicated interface for chip etching equipment without adapters. The input is an industrial-grade waterproof ferrule, and the output is a customized tin-plated wire, directly matching the power interface specifications of the etching equipment. This facilitates installation and eliminates parasitic interference caused by adapters. The outer shell has standardized mounting holes, allowing for direct rigid connection to the etching equipment chassis. Combined with the pearl cotton anti-vibration structure of the coil, it effectively suppresses structural loosening and winding breakage caused by equipment vibration, meeting the 24-hour continuous operation requirements of the etching equipment. The three-phase symmetrical circuit design perfectly matches the three-phase power supply architecture of the chip etching equipment, ensuring the consistency of voltage and current of each phase, avoiding equipment operation fluctuations caused by power imbalance, and significantly improving power supply stability compared to general filters.

[0026] 3. The output side is equipped with a discharge module consisting of a resistor and a capacitor connected in parallel, enabling rapid and safe discharge of capacitor charge. Simultaneously, it limits current and divides voltage, suppresses surges, and effectively avoids instantaneous high-voltage surges during power-on / off, preventing filter capacitor breakdown and damage to the core circuitry of the etching equipment. The capacitor selection (CX1 / CY1) complies with IEC safety standards. The redundant design of the three-stage filter significantly reduces the risk of damage to the core components of the etching equipment from power supply anomalies (harmonics, spikes, surges), greatly reducing the equipment failure rate. The sealing design of the silicone rubber waterproof and dustproof gasket and epoxy resin potting achieves an IP54 protection rating for the filter, allowing direct application in the humid and dusty environments of semiconductor cleanrooms without the need for additional protective cabinets, thus reducing installation costs.

[0027] IV. The parameters of all filter components (inductance, capacitance, and resistance) are precisely matched to the power supply and frequency characteristics of the chip etching equipment. While efficiently filtering out interference, it will not cause attenuation or distortion of normal power signals, ensuring the power supply stability of the etching equipment. The integrated structure reduces external connection points and sources of failure. All internal components are welded, ensuring high connection reliability. The mean time between failures (MTBF) of the filter perfectly matches the continuous production requirements of the chip etching equipment.

[0028] V. This filter is a customized product specifically for chip etching equipment. It can directly replace general filters without the need for additional adapters and protective accessories, reducing the installation and maintenance costs of the equipment. It effectively improves the etching accuracy and operational stability of chip etching equipment, reduces wafer scrap and equipment failure caused by power supply problems, improves the yield and production efficiency of semiconductor wafer processing, and promotes the localization and upgrading of high-end semiconductor manufacturing equipment. Attached Figure Description

[0029] The accompanying drawings, which form part of this specification, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0030] Figure 1 This is a schematic diagram of the overall structure of a power filter for chip etching electrical equipment provided in an embodiment of the present invention.

[0031] In the diagram: 1. ferrule; 2. terminal housing; 3. outer shell; 4. side plate; 5. end cap; 6. first differential mode capacitor; 7. customized coil; 8. second differential mode capacitor; 9. common mode capacitor; 10. resistor; 11. output wire; 12. waterproof and dustproof gasket. Detailed Implementation

[0032] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0033] The following detailed description is exemplary and intended to provide further detailed explanation of the invention. Unless otherwise specified, all technical terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this invention is for describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention.

[0034] Example:

[0035] Please see Figure 1This embodiment provides a dedicated power filter for chip etching electrical equipment. This dedicated power filter has an integrated structure, consisting of four core parts: a housing assembly, a filtering unit, an interface assembly, and a protection assembly. Each component is modularly designed and precisely assembled to form a dedicated filtering system adapted to chip etching equipment. The specific structure and connection relationships are as follows:

[0036] ① Housing assembly

[0037] The housing assembly serves as the basic support and protection structure for the filter, comprising the outer shell 3, side plates 4, and end caps 5. Both the outer shell 3 and side plates 4 are integrally formed from galvanized steel sheet metal, with evenly distributed mounting nuts pre-installed on the inner side to achieve weld-free fixing of the filter unit, improving assembly stability and ease of later maintenance. The outer shell 3 has standardized mounting holes, which can be directly and rigidly connected to the chassis of the chip etching equipment, eliminating vibration interference caused by installation gaps.

[0038] ② Filtering unit

[0039] The filter unit is the core functional unit of the filter, located inside the housing assembly. It adopts a three-phase symmetrical multi-stage filter circuit design, including a customized coil 7, a first differential-mode capacitor 6, a second differential-mode capacitor 8, and a common-mode capacitor 9. The parameters of each component are precisely matched to the three-phase power supply (380V three-phase AC) and frequency characteristics (50 / 60Hz) of the chip etching equipment. Specific structure and manufacturing process:

[0040] Customized Coil 7: This is a manganese-zinc magnetic ring composite inductor. The manufacturing process is as follows: Polyester tape is tightly wound around the surface of a high-permeability manganese-zinc magnetic ring for insulation and protection, and yellow tape is used for initial fixation; Two insulated magnetic rings are taken, and pearl cotton pads are placed on their mating surfaces for shock absorption and cushioning, and then they are fixed with yellow tape to form an integrated magnetic ring assembly; Three sets of windings are symmetrically wound on the integrated magnetic ring assembly using high-temperature resistant enameled wire to form six leads (three on each side of the magnetic ring assembly), which is adapted to the symmetrical design of three-phase power supply, effectively improving the common-mode / differential-mode interference suppression capability of the inductor, and the shockproof structure avoids winding breakage caused by equipment vibration during operation;

[0041] First differential mode capacitor 6: It adopts three 3.3uF safety standard CX capacitors as the core, and connects one end of the three capacitors in parallel and then welds them into one piece to form a three-phase differential mode filter unit, which accurately filters out differential mode interference between phase lines;

[0042] The second differential-mode capacitor 8 and common-mode capacitor 9 are composite capacitor units. They are formed by connecting three 3.3uF safety CX capacitors and one 10nF high-frequency ceramic capacitor in parallel and then welding them together. This can simultaneously achieve high-frequency differential-mode interference filtering and common-mode interference suppression, matching the wide-band interference requirements of chip etching equipment.

[0043] Multi-stage filter circuit connection: The customized coil 7 is placed in the middle of the filter unit. The three leads on one side of the coil are connected in series with the three leads of the first differential mode capacitor 6 and soldered. The three leads on the other side of the coil are connected in series with the three leads of the second differential mode capacitor 8 and the common mode capacitor 9 and soldered. The grounding terminal of the common mode capacitor 9 is directly soldered to the sheet metal grounding terminal of the outer casing 3, forming a three-stage series filter circuit of "first differential mode capacitor 6 + customized coil 7 + second differential mode capacitor 8 + common mode capacitor 9", which realizes full coverage filtering of wide-band (10kHz~1GHz) electromagnetic interference.

[0044] It should be noted that in this scheme, a controllable impedance fine-tuning branch (not shown in the figure) is connected in parallel before the grounding node of the second differential-mode capacitor 8 and common-mode capacitor 9 in the three-stage filter circuit. This branch consists of a high-precision sampling resistor, a high-speed analog switch array, and a set of precision RC networks controlled by digital potentiometers. The core is the addition of an interference spectrum monitoring and control unit. This unit continuously monitors the voltage / current signal at the filter input, analyzes the frequency components and amplitude of the most significant interference signal using Fast Fourier Transform (FFT), and dynamically adjusts the resistance value of the digital potentiometer according to the built-in algorithm, thereby changing the impedance of the parallel branch and achieving targeted deep suppression of interference at specific frequency points.

[0045] To achieve the above adaptive adjustment, the control unit needs to calculate the target resistance value that the digital potentiometer needs to be set based on the monitored main interference frequency and target suppression depth. The calculation formula is as follows:

[0046]

[0047] In the formula: Rset is the target resistance value to be set by the digital potentiometer, in ohms (Ω). This is the calculated output of the formula and is the direct target of control execution; fdisturb is the frequency of the most significant interference signal monitored and identified in real time by the interference spectrum monitoring unit, in Hertz (Hz). This data comes from real-time high-speed sampling and FFT analysis of the signal at the filter input; Cadj is the capacitance value of the fixed capacitor in the parallel controllable impedance fine-tuning branch, in farads (F). This is a constant parameter determined by the hardware design, for example, selected as 1 nanofarad (1 nF); Atarget is the suppression depth required by the system for this major interference frequency, in decibels (dB). This is a constant preset according to the overall performance index of the filter, for example, set to -70dB; f0 is the reference frequency of the filter, in Hertz (Hz). This is a constant related to the basic design of the filter's main circuit, usually set as the center frequency of the initial design suppression curve of the filter, for example, 100kHz; The term is used to compensate for the impact of the main filter circuit's own impedance changes on the fine-tuning branch effect under different frequency bands, ensuring adjustment accuracy; π is pi, a mathematical constant.

[0048] The microcontroller (MCU) in the interference spectrum monitoring and control unit is responsible for executing the calculation of this formula. After acquiring the real-time fdisturbance, the MCU calls the formula embedded in the program and, in conjunction with the known constant parameters Cadj, Atarget, and f0, calculates the required Rset.

[0049] The specific application process of the calculation results:

[0050] The MCU sends the calculated Rset value to the digital potentiometer in the controllable impedance fine-tuning branch via a digital communication interface such as SPI or I2C. Upon receiving the command, the digital potentiometer immediately adjusts its internal resistance to Rset ohms. This change in the digital potentiometer alters the complex impedance characteristics of the entire parallel controllable impedance fine-tuning branch, thus working in synergy with the main filter circuit to minimize the impedance of the entire filter at the current fdisturb frequency (i.e., maximize the suppression depth), thereby achieving precise and deep filtering of the most significant interference. This process is dynamic and cyclical; the monitoring unit continuously monitors the filter, and once the fdisturb changes, the MCU recalculates and adjusts Rset to ensure the filter remains "locked in" and suppresses the most significant interference.

[0051] This solution, building upon the aforementioned approach, introduces a parameter adaptive control module, offering significant advantages over traditional fixed-parameter filters. By sensing real-time changes in the power grid interference spectrum and automatically adjusting filter parameters, the filter remains in optimal operating condition, effectively addressing the complex and ever-changing interference threats posed by etching equipment at different process stages and in varying workshop power grid environments. This represents a leap from "general protection" to "precisely customized protection." For sporadic, high-energy surges or resonant interference at specific frequencies, traditional fixed filters may lack sufficient suppression capabilities at those frequencies. This solution, upon detecting such interference, immediately strengthens its suppression capability at those frequencies, forming a "dynamically reinforced barrier." This significantly reduces the probability of rare but dangerous interference pulses penetrating the filter and damaging core equipment, resulting in more comprehensive and reliable protection. The monitoring data of the interference spectrum can be recorded and analyzed, providing data support for equipment health management. For example, when a specific frequency interference is detected to be persistent or its amplitude gradually increasing, it can provide early warning of potential workshop power grid problems or adjacent equipment failures, transforming "post-event maintenance" into "pre-event prevention," thus improving the intelligent operation and maintenance level of the entire production system. By dynamically adjusting the filter, it is prevented from remaining in a "high-power" suppression state when interference is low, which helps reduce the filter's own temperature rise and optimize energy efficiency. At the same time, targeted suppression reduces useless power consumption and may extend the lifespan of internal components such as capacitors and inductors.

[0052] ③ Interface components

[0053] The interface component is the power input / output unit of the filter, adopting a dedicated interface specification for chip etching equipment. It features a no-adapter design to avoid parasitic interference, and includes an input connector interface and an output wire interface.

[0054] Power input connector interface: Insert the industrial-grade waterproof ferrule 1 into the terminal housing 2 and rigidly fix it to the preset mounting position on the top of the side plate 4 with an internal hex screw; use an electric hex wrench to crimp and fix the three-phase input wires to the terminals of the ferrule 1, and connect and weld the other end of the input wires in series with the free end lead of the first differential capacitor 6 to achieve gapless power input.

[0055] Output wire 11 interface: Select three high temperature resistant, low impedance tin-plated wires. One end of each wire is connected in series with the free end leads of the second differential mode capacitor 8 and common mode capacitor 9 and soldered. The other end is led out from the preset hole on the side of the housing 3 and directly connected to the power input terminal of the chip etching equipment to adapt to the three-phase power supply wiring requirements of the etching equipment.

[0056] ④ Protective components

[0057] The protection component serves as the safety assurance unit for the filter, comprising a resistive discharge module and a waterproof and dustproof sealing module, providing multiple protections including charge discharge, surge suppression, and environmental sealing.

[0058] Resistor discharge module: Resistor 10 is selected from three high-power metal film resistors, which are connected in parallel and welded to the second differential mode capacitor 8 and common mode capacitor 9 in a one-to-one correspondence. The resistance value of resistor 10 matches the capacitor parameters, which can realize the safe and fast discharge of capacitor charge, and at the same time play the role of current limiting and voltage division, effectively suppressing the instantaneous high voltage surge when the equipment is powered on / off, and avoiding capacitor breakdown and damage to the equipment circuit by etching.

[0059] Waterproof and dustproof sealing module: It adopts temperature-resistant and aging-resistant silicone rubber waterproof and dustproof gaskets 12, which are assembled in two places: one is assembled at the splicing gap of the shell components, and the whole shell is sealed after being filled with epoxy resin; the other is assembled at the output wire 11 hole of the shell 3 to achieve a seamless seal between the wire and the hole. The protection level reaches IP54, which is suitable for the moisture and dust protection requirements of semiconductor cleanrooms.

[0060] ⑤ Overall assembly process

[0061] Housing assembly pretreatment: The outer shell 3, side plate 4, and end cap 5 are cleaned and annealed, hot-dip / electroplated, passivated, oiled, and fingerprint-resistant to improve the protection level. Nuts are installed in the preset positions.

[0062] Filter unit fabrication: Customized coil 7, differential mode capacitor, second differential mode capacitor 8 and common mode capacitor 9 are fabricated according to the above process to build a three-stage series filter circuit. After welding, insulation test is performed.

[0063] Component assembly: Fix the filter unit in the housing with the mounting nuts, then assemble the interface components and the 10-resistor discharge module in sequence. After completing all wiring and soldering, perform a continuity test.

[0064] Sealing treatment: Install waterproof and dustproof gaskets 12 at the joints of the housing and the output port, and fill with epoxy resin and cure.

[0065] Finished product testing: The filter is tested for electromagnetic interference suppression, surge suppression, insulation withstand voltage, and waterproof and dustproof properties. After passing the tests, it is packaged.

[0066] This invention provides a dedicated power filter designed to meet the core requirements of chip etching electrical equipment. Compared to existing general-purpose power filters, it offers significant advantages in terms of structural innovation, performance optimization, strong adaptability, and high safety. The core technical solution of this invention can be replaced by the following equivalent alternatives, whose core functions and beneficial effects remain consistent with the original solution:

[0067] (a) Magnetic ring and winding substitution for customized coils

[0068] Magnetic ring material: Replacing the manganese-zinc magnetic ring with a nickel-zinc or nanocrystalline magnetic ring makes it suitable for electromagnetic interference suppression scenarios at higher frequencies, matching the needs of ultra-high frequency etching equipment;

[0069] Enameled wire winding: Replacing ordinary enameled wire with silver-plated enameled wire reduces the internal resistance of the conductor and improves high-frequency transmission performance, making it suitable for high-power etching equipment;

[0070] Number of windings: The three windings can be adjusted to two or four windings according to the phase requirements of the etching equipment, to adapt to single-phase / four-phase power supply etching equipment.

[0071] (II) Parameter and Type Substitution of Filter Capacitors

[0072] Differential mode capacitors: Replace the three 3.3uFCX capacitors with three 0.001uF~10uFCX capacitors. As long as the capacitance and safety requirements of the three-phase differential mode filter are met, equivalent differential mode interference suppression can be achieved.

[0073] Differential / common mode composite capacitor: The combination of 3.3uFCX capacitor + 10nF ceramic capacitor is replaced with 2.2uFCX capacitor + 22nF thin film safety capacitor. The monolithic capacitor has better high-frequency characteristics and can achieve common mode interference suppression at higher frequency bands.

[0074] (iii) Alternative designs for protective components

[0075] Resistive discharge module: Replaces metal film resistors with wire-wound resistors, improving the power and temperature resistance of the resistors, and is suitable for etching equipment in high-temperature environments;

[0076] Waterproof and dustproof sealing: Silicone rubber gaskets are replaced with fluororubber gaskets, and epoxy resin potting is replaced with polyurethane potting, improving the chemical corrosion resistance of the sealing components and making them suitable for etching workshops with corrosive gases.

[0077] (iv) Alternative configuration of interface components

[0078] Input interface: The industrial-grade waterproof connector is replaced with an aviation plug, which improves the reliability of the input interface and the waterproof rating (IP67), making it suitable for etching equipment that requires frequent disassembly;

[0079] Output interface: Replace the tin-plated wires with copper busbars to reduce the wiring impedance on the output side and improve the power supply capacity of high-power etching equipment.

[0080] This embodiment is a dedicated power filter for a chip etching equipment (380V three-phase AC, power 50kW, etching accuracy 28nm). Those skilled in the art can adjust the component specifications according to the parameters of the etching equipment.

[0081] I. Specifications and Manufacturing of Core Components

[0082] Customized manganese-zinc magnetic ring coil: A high-permeability manganese-zinc magnetic ring with an outer diameter of 36mm, an inner diameter of 23mm, and a height of 15mm (initial permeability μi=10000) is selected. The polyester tape is 0.1mm thick polyimide tape, the pearl cotton pad is 2mm thick, the yellow tape is high-temperature insulating tape (temperature resistance 150℃), and the enameled wire is two φ1.628mm polyurethane enameled wires (temperature resistance 180℃); three sets of windings are wound, each set of windings has 11 turns, and three leads are led out from each side, with a lead length of 40mm;

[0083] First differential mode capacitor 6: Select three 3.3uF / 305VAC safety standard CX2 capacitors with a lead length of 25mm. Connect the leads in parallel at one end and then solder them. The soldering temperature is 480℃ and the soldering time is 5-8s.

[0084] The second differential mode capacitor 8 and common mode capacitor 9: Select three 3.3uF / 305VAC safety standard CX2 capacitors + one 10nF / 400V ceramic capacitor, with a lead length of 31mm, and solder the leads in parallel at one end.

[0085] Resistor 10: Three 330kΩ / 2W metal film resistors 10 are selected, with a lead length of 28mm;

[0086] Waterproof and dustproof gasket 12: Selected rubber gasket with a hardness of 70 Shore, inner diameter matches the output wire 11 (φ4.8mm), outer diameter matches the 3 holes in the outer shell (φ8mm).

[0087] Housing components: The outer shell 3, side plate 4, and end cap 5 are made of 1.0mm galvanized steel sheet (for semiconductor workshops only), and the mounting nuts are M4 stainless steel nuts with 8 preset mounting positions;

[0088] Interface components: Socket 1 is an industrial-grade waterproof socket (IP65), compatible with 690V / 40A three-phase input; Output wire 11 is a 10AWG tinned copper wire, resistant to temperature -40℃~+125℃, and 100mm in length.

[0089] II. Assembly Steps

[0090] Housing pretreatment: The outer shell 3, side plate 4, and end cap 5 are cleaned, annealed, hot-dip / electroplated, passivated, oiled, and fingerprint-resistant to improve the protection level. M4 stainless steel nuts are installed at preset positions on the side plate 4 and the inner side of the outer shell 3.

[0091] Coil preparation: tightly wrap polyimide tape around the surface of manganese zinc magnetic ring and fix it initially with yellow tape; place pearl cotton pads between the two magnetic rings and wrap yellow tape to form an integrated component; symmetrically wind three sets of polyurethane enameled wire, lead out six leads, and put insulating sleeves on both ends of the coil.

[0092] Filter circuit construction: Weld the parallel terminal of the differential mode capacitor in series with the three leads on one side of the coil, and weld the three leads on the other side of the coil in series with the parallel terminal of the differential / common mode composite capacitor; Weld the three resistors 10 in parallel with the differential / common mode composite capacitor respectively, and weld the ground terminal of the common mode capacitor 9 to the grounding copper wire.

[0093] Interface assembly: Insert the ferrule 1 into the terminal housing 2 and fix it to the top of the side plate 4 with an Allen screw. Crimp the input wire to the terminal of the ferrule 1 and solder the other end to the free end of the differential-mode capacitor. Solder the output wire 11 to the free end of the differential / common-mode composite capacitor and lead it out from the hole on the side of the housing 3.

[0094] Sealing treatment: Install silicone rubber gaskets at the joints of the housing and the mating surfaces of the end cap 5 and the outer shell 3, and fill the pre-set injection port with epoxy resin and cure (25℃, 24h); install silicone rubber gaskets at the holes of the output wire 11 and fix them with pressure caps;

[0095] III. Performance Testing

[0096] The fabricated dedicated power filter underwent performance testing using an electromagnetic interference tester, surge generator, insulation withstand voltage tester, and waterproof / dustproof test chamber. The test results are as follows:

[0097] Electromagnetic interference suppression: In the 10kHz~1GHz frequency band, differential mode interference suppression ratio ≥60dB, common mode interference suppression ratio ≥70dB, ground coupling noise suppression ratio ≥65dB, fully meeting the power purity requirements of 28nm chip etching equipment;

[0098] Surge suppression: It can withstand 1.2 / 50μs lightning surge (6kV) and 8 / 20μs operational surge (20kA). The filter is undamaged after the surge, and the output voltage fluctuation is ≤±1%.

[0099] Insulation withstand voltage: The insulation resistance between the phase conductor and the outer casing 3 is ≥1000MΩ, and the withstand voltage is 4kVDC / 1S without breakdown or flashover;

[0100] Waterproof and dustproof: Tested to IP54 level, no dust entered, no water seepage, and internal components functioned normally;

[0101] Continuous operation: After 1000 hours of continuous operation on a 50kW etching machine, the filter temperature rise is ≤30℃, the output power ripple is ≤50mV, and the etching machine has no precision deviation or fault shutdown.

[0102] As is known from common technical knowledge, this invention can be implemented through other embodiments that do not depart from its spirit or essential characteristics. Therefore, the disclosed embodiments described above are merely illustrative and not exhaustive. All modifications within the scope of this invention or its equivalents are included in this invention.

[0103] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A power filter specifically for chip etching electrical equipment, characterized in that, It includes a housing assembly, a filter unit disposed inside the housing assembly, an interface assembly electrically connected to the filter unit, and a protective assembly; The housing assembly includes an outer shell (3), side plates (4), and end caps (5); The filtering unit includes a first differential mode capacitor (6), a customized coil (7), a second differential mode capacitor (8), and a common mode capacitor (9); the first differential mode capacitor (6), the customized coil (7), the second differential mode capacitor (8), and the common mode capacitor (9) are connected in series, and the ground terminal of the common mode capacitor (9) is connected to the outer casing (3); The interface component includes an input connector interface for connecting to an external power supply and an output wire (11) interface for connecting to a chip etching device. The input connector interface is connected to the first differential-mode capacitor (6), and the output wire (11) interface is connected to the second differential-mode capacitor (8) and the common-mode capacitor (9). The protective assembly includes a resistor discharge module connected in parallel with the second differential mode capacitor (8) and / or the common mode capacitor (9), and a waterproof and dustproof gasket (12) for sealing.

2. The power filter for chip etching electrical equipment according to claim 1, characterized in that, The customized coil (7) includes at least one magnetic ring, an insulating layer wound on the magnetic ring, and multiple sets of windings symmetrically wound on the magnetic ring, with anti-vibration pads provided between adjacent magnetic rings.

3. The power filter for chip etching electrical equipment according to claim 1, characterized in that, The first differential capacitor (6) is composed of multiple safety capacitors connected in parallel, and its number matches the number of power supply phases of the chip etching equipment.

4. The power filter for chip etching electrical equipment according to claim 1, characterized in that, The second differential mode capacitor (8) and the common mode capacitor (9) are a composite capacitor unit formed by connecting a safety capacitor and a high-frequency capacitor in parallel.

5. The power filter for chip etching electrical equipment according to claim 1, characterized in that, It also includes a controllable impedance fine-tuning branch, which is connected in parallel before the grounding node of the second differential-mode capacitor (8) and the common-mode capacitor (9); the controllable impedance fine-tuning branch includes an interference spectrum monitoring unit, a control unit, and an RC network controlled by a digital potentiometer; the interference spectrum monitoring unit is used to monitor the signal at the input of the filter and identify the main interference frequency, and the control unit is used to calculate the target resistance value and control the digital potentiometer to adjust to the target resistance value, so as to dynamically change the impedance of the controllable impedance fine-tuning branch.

6. The power filter for chip etching electrical equipment according to claim 5, characterized in that, The formula for calculating the target resistance value is: In the formula: Rset is the target resistance value that the digital potentiometer needs to be set; fdisturb is the frequency of the most important interference signal monitored and identified in real time by the interference spectrum monitoring unit; Cadj is the capacitance value of the fixed capacitor in the parallel controllable impedance fine-tuning branch; Atarget is the suppression depth required by the system for the main interference frequency; f0 is the reference frequency of the filter; π is pi.

7. The power filter for chip etching electrical equipment according to claim 1, characterized in that, The outer shell (3) and the side plate (4) are made of galvanized steel sheet, and the outer shell (3) has mounting holes for rigid connection with the chip etching equipment chassis.

8. The power filter for chip etching electrical equipment according to claim 1, characterized in that, The input connector interface includes an industrial-grade waterproof ferrule (1) and a terminal housing (2); the output wire (11) is a tin-plated copper wire.

9. The power filter for chip etching electrical equipment according to claim 1, characterized in that, The resistor discharge module in the protection assembly includes a plurality of resistors (10), each resistor (10) being connected in parallel with the corresponding second differential mode capacitor (8) or the common mode capacitor (9).

10. The power filter for chip etching electrical equipment according to claim 1, characterized in that, The waterproof and dustproof gasket (12) is a silicone rubber gasket, which is installed at the splicing gap of the housing assembly and at the lead-out hole of the output wire (11).

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