High-efficiency demolding equipment and demolding method for mold surface carbon film layer based on volume-variable cavity

Abstract

The invention discloses efficient demolding equipment and demolding method for a mold surface carbon film layer based on a variable volume cavity, relates to the technical field of precision mold surface treatment, and provides a volume self-adaptive cavity design and process parameter dynamic matching strategy. By arranging a variable volume cavity module and a built-in specific algorithm dynamic control unit and combining dynamic matching of parameters such as radio frequency, gas flow and temperature, closed-loop control of'cavity volume change-process parameter self-adaption-optimal film stripping effect 'is achieved, efficient and uniform film stripping of molds of different specifications is achieved, and the production efficiency is improved. Therefore, the limitation of the existing vacuum plasma carbon film layer removal method is effectively solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of precision mold surface treatment, and particularly relates to a high-efficiency mold surface carbon film layer stripping device and method based on a variable volume cavity. BACKGROUND

[0002] The carbon film layer is a metastable structure formed by carbon atoms through sp 3 and sp 2 hybrid bonds. Due to its high hardness (up to 2300 HV), high elastic modulus, low friction coefficient (about 0.1 against steel), and other excellent properties, the carbon film layer is widely used in tool coating, mold, precision mechanical parts, and other scenarios to improve wear resistance, lubricity, and service life. For example, in the production of optical lens mold pressing, the mold pressing mold surface is usually coated with a diamond-like carbon film (DLC film, a type of carbon film layer) to provide protection. However, the carbon film layer will gradually fail after a certain period of use and needs to be removed and re-coated, so efficient removal of the carbon film layer is the basis for maintenance of important parts such as molds.

[0003] In the prior art, vacuum plasma reaction methods have been widely used for carbon film layer removal. For example, patent application CN107236926A discloses a vacuum plasma carbon film layer removal method. Specifically, in a low vacuum environment, charged plasma is generated by a strong oxidizing gas (such as oxygen) under the induction of a power source (medium frequency, pulse, or radio frequency power source), and reacts with the DLC film layer by layer to achieve non-damaging film removal. This method has the advantages of no need for chemical reagents, no defects in the substrate, and low cost, but has the following limitations: 1. Fixed cavity volume: The reaction space cannot be dynamically adjusted according to the size or batch of the mold, resulting in high energy consumption when processing small-sized molds and low efficiency when processing large-sized molds in batches; 2. Static process parameters: The frequency of the radio frequency power source and the gas flow rate need to be manually preset, and cannot be optimized in real time according to the change in cavity volume, which can easily lead to uneven plasma distribution and fluctuation in film removal efficiency. SUMMARY

[0004] The present application discloses a high-efficiency mold surface carbon film layer stripping device and method based on a variable volume cavity, proposes a volume-adaptive cavity design and a process parameter dynamic matching strategy, and realizes efficient and uniform film removal for molds of different specifications to solve the limitations of existing vacuum plasma carbon film layer removal methods.

[0005] The technical solution adopted by the present application is as follows: A high-efficiency mold surface carbon film layer stripping device based on a variable volume cavity, comprising: A variable volume cavity module, which is composed of a cavity body and an openable cavity cover, the volume of the cavity body is dynamically adjusted by replacing the modular cavity or the telescopic cavity wall to adapt to different sizes or batches of the mold to be stripped; A rack, which is fixedly connected with the cavity body through plane bolts, the bottom of the rack is provided with movable wheels; A vacuum system, which includes a vacuum pump, a vacuum gauge and a KF vacuum interface, the KF vacuum interface is welded to the outer wall of the cavity body, which is used to maintain the vacuum degree in the cavity less than 10 Pa; A gas supply system, which includes a strong oxidizing reaction gas source, a mass flow meter and a mosquito-like gas distributor, the bottom surface of the gas distributor is provided with capillary holes for uniformly introducing the reaction gas; A radio frequency power supply unit, which is used to provide high frequency current with an output frequency range of 10-18 MHz, the current output end of the radio frequency power supply is connected with the conductor arranged in the cavity, and the power of the radio frequency power supply is dynamically adjusted according to the volume of the cavity, and the adjustment relationship is that when the aperture of the cavity increases by 50%, the power of the radio frequency power supply is adjusted by 20-40%; A control unit, which is electrically connected with the vacuum system, the gas supply system and the radio frequency power supply unit, is used to monitor the volume of the cavity, the vacuum degree, the temperature and the plasma current in real time, and dynamically adjusts and controls the frequency of the radio frequency power supply, the gas flow, the reaction temperature and the time through a specific algorithm to match the volume change of the cavity.

[0006] Further, the volume range of the variable volume cavity module is 5-18 L, the cavity body is in the shape of a pot, and the openable cavity cover is connected with the cavity body through an adjustable hinge.

[0007] Further, the cavity body is provided with a hole in the middle bottom, a metal pipe is fixed in the hole, and a fixed base is arranged above the hole in the cavity body, the fixed base is bolted to the bottom of the cavity, an insulating layer is arranged on the fixed base, and the insulating layer is connected with the fixed base through non-circular center bolts; the conductor arranged in the cavity is a two-layer conductor disc, the conductor disc is fixed on the insulating layer, the upper layer of the conductor disc is a flat top plate for placing the mold, and the lower layer of the conductor disc is a base plate, a conductor rod is fixed in the center of the base plate through a conductor bolt, the conductor rod is sealed with the bottom of the cavity by a composite sealing mode of a plastic block interference fit, a sealant and a vacuum sealing clamp, an insulating sleeve is sleeved on the upper end of the conductor rod to avoid conduction with the cavity, and the lower end of the conductor rod is sequentially penetrated through the insulating layer, the fixed base, the metal pipe fixed in the hole of the cavity bottom and connected with the current output end of the radio frequency power supply of the radio frequency power supply unit.

[0008] Further, the control unit is a PLC control system with a touch screen, and a volume-parameter matching algorithm is built-in, and at least 10 sets of process parameter templates corresponding to different volumes are stored, and the volume-parameter matching algorithm is specifically: RF power frequency f = 13 + 0.2×(V - 10) (when V = 5L, f = 12MHz; V = 18L, f = 14.6MHz, both in the effective output range of 10-18MHz); Plasma current I = 0.6 + 0.04×V; Oxygen flow Q = 10×V (volume and gas flow are positively correlated, which ensures uniform plasma concentration in the cavity); Reaction temperature T = 200 - 2×(V - 10) (the larger the volume, the lower the heat dissipation efficiency, and the temperature is moderately reduced to avoid overheating of the mold substrate); Single cycle effective reaction time t = 25 + 0.5×(V - 10) (the larger the volume, the larger the corresponding mold size / batch, and the effective reaction time is prolonged to ensure complete removal of the carbon film layer); Duty cycle D = 50 + 1×(V - 10) (the larger the volume, the higher the duty cycle needs to be improved to maintain the stability of the plasma); In the above formulas, V is the volume of the cavity, unit L; f is the RF power frequency, unit MHz; I is the plasma current, unit A; Q is the oxygen flow, unit sccm; T is the reaction temperature, unit ℃; t is the effective reaction time in a single cycle, unit min; D is the duty cycle, unit %.

[0009] A mold surface carbon film layer demolding method based on a variable volume cavity, comprising the following steps: (1) Cavity volume adaptation: according to the size and batch of the mold to be demolded, the volume of the variable volume cavity module is selected or adjusted; (2) Vacuum environment construction: place the mold to be demolded on the conductor disc in the cavity, close the cavity cover, and vacuumize through the vacuum system to a pressure of ≤10Pa in the cavity; (3) Dynamic parameter regulation: input the volume of the cavity, and the control unit automatically adjusts or manually inputs the process parameters according to the volume of the cavity, and the volume-parameter matching algorithm is specifically: RF power frequency f = 13 + 0.2×(V - 10); Plasma current I = 0.6 + 0.04×V; Oxygen flow Q = 10×V; Reaction temperature T = 200 - 2×(V - 10); Single cycle effective reaction time t = 25 + 0.5x(V - 10); Duty cycle D = 50 + 1x(V - 10); In the above formula, V is the volume of the cavity, unit L; f is the frequency of the radio frequency power supply, unit MHz; I is the plasma current, unit A; Q is the oxygen flow rate, unit sccm; T is the reaction temperature, unit ℃; t is the effective reaction time in a single cycle, unit min; D is the duty cycle, unit %; (4) Plasma reaction: strong oxidizing reaction gas is introduced into the vacuum cavity, and stabilized for a period of time, the radio frequency power supply is turned on, the reaction gas is ionized into charged plasma, the carbon film layer on the surface of the mold is bombarded directionally, and the carbon atoms are reacted and vaporized through physical and chemical effects and discharged with the vacuum system; (5) Real-time feedback adjustment: the plasma current and temperature in the cavity are monitored, the gas flow rate and radio frequency power are fine-tuned through PID algorithm to ensure the uniformity of the film removal, wherein the PID algorithm is specifically: Plasma current deviation e I = I0 - I t ; Reaction temperature deviation e T = T0 - T t ; Oxygen flow rate fine-tuning amount ΔQ = Kp1x e I + Ki1x∫e I dt + Kd1x(de I / dt), wherein Kp1=5, Ki1=0.2, Kd1=0.5; Radio frequency power fine-tuning amount ΔP = Kp2x e T + Ki2x∫e T dt + Kd2x(de T / dt), wherein Kp2=3, Ki2=0.1, Kd2=0.3; In the above formula, I0 is the initial calculated plasma current, unit A; I t is the real-time detected plasma current, unit A; T0 is the initial calculated reaction temperature, unit ℃; T t is the real-time detected reaction temperature, unit ℃; Kp1, Ki1, Kd1 are the proportional, integral, and differential coefficients of oxygen flow rate fine-tuning; Kp2, Ki2, Kd2 are the proportional, integral, and differential coefficients of radio frequency power fine-tuning; ΔQ is the oxygen flow rate fine-tuning amount, unit sccm; ΔP is the radio frequency power fine-tuning amount, unit W; (6) Cycle and termination: stop the reaction every 30 minutes and observe the film removal effect, repeat steps (3)-(5) after 5-10 minutes of stoppage until the carbon film layer is completely or mostly removed, turn off the radio frequency power supply, open the exhaust valve to release the gas in the chamber, open the chamber cover and take out the mold.

[0010] As preferred, the strong oxidizing reaction gas is oxygen.

[0011] Compared with the prior art, the beneficial effects of the present application are as follows: 1. Volume self-adaptive design, improving processing flexibility and mass production adaptability, the present application can adapt to molds with a diameter of 50-500 mm and batch size of 1-50 pieces per batch by replacing different volume chamber modules (5-18L) or telescopic chamber walls, avoiding the disadvantages of traditional fixed volume equipment such as high energy consumption for small molds and batch processing for large molds. For example, when processing small molds with a diameter of 100 mm, a 5L chamber is selected, which can reduce energy consumption by 30%; when processing large molds with a diameter of 300 mm, a 15L chamber is selected, which can improve efficiency by 50% without the need for splitting; and the chamber and the rack are quickly fixed by bolts, equipped with movable wheel sets, and a single person can complete the chamber replacement (≤10 minutes), meeting the flexible production needs of multiple specifications of molds. 2. Dynamic parameter control, realizing the collaborative optimization of plasma uniformity and film removal efficiency, the present application dynamically controls the built-in specific algorithm unit combined with the PID algorithm to monitor the plasma current and temperature, and adjusts the gas flow and radio frequency power in real time, solving the problems of film layer residue or over-corrosion caused by traditional "open loop control", and improving the film removal qualification rate from 85% to 99%. 3. Equipment structure optimization, ensuring stability and automation level, the present application sets up a mosquito incense-like gas distributor with capillary holes (diameter 0.5-1 mm) on the bottom surface, which makes the strong oxidizing gas form a spiral flow field in the chamber, the coverage rate is improved to more than 95%, avoiding the "edge effect" caused by traditional single-point gas inlet; the conductor rod adopts "plastic block interference fit + sealant + vacuum sealing clamp" composite sealing, the air leakage rate is ≤1×10 -5 Pa·m 3 / s; the chamber and the radio frequency power output end are insulated by KF connecting head, the breakdown voltage is ≥2000V, and the running stability is improved by 3000 hours without failure; the PLC control system with touch screen has 10 groups of volume-parameter templates built-in, supports one-key calling, and simplifies the operation process by 60%; 4. Process method innovation, considering film removal efficiency and surface quality, the present application stops every 30 minutes to observe the film removal effect, combined with "intermittent reaction" of 5-10 minutes of stoppage, avoiding the change of substrate performance caused by continuous high temperature (such as hardness reduction), the surface roughness Ra is ≤0.1μm, reaching the mirror level effect. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 Structure diagram of the conductor at the bottom of the cavity body; Figure 2 Structure diagram of the sealing of the conductor rod; The reference numerals in the figure are as follows: 1, top plate; 2, base plate; 3, insulation layer; 4, fixed base; 5, metal pipe; 6, conductor rod; 7, sealing plastic block; 8, vacuum pipe joint; 9, sealing glue; 10, vacuum sealing clamp position. DETAILED DESCRIPTION

[0013] The advantages and various effects of the present application will be more clearly presented hereinafter in combination with specific embodiments and examples. Those skilled in the art should understand that these specific embodiments and examples are used to illustrate the present application, rather than limit the present application.

[0014] Throughout the specification, unless otherwise specifically indicated, the terms used herein are to be understood as having the meanings commonly used in the art. Therefore, unless otherwise defined, all technical and scientific terms used herein have the same meanings as generally understood by those skilled in the art to which the present application belongs. If there is a conflict, the present specification takes precedence.

[0015] Unless otherwise specifically indicated, various raw materials, reagents, instruments and efficient stripping equipment used in the present application can be purchased from the market or can be prepared by existing methods.

[0016] The stripping equipment structure used in each of the following examples includes: A variable-volume cavity module, which is composed of a cavity body and an openable and closable cavity cover, the volume of the cavity body can be dynamically adjusted by replacing a modular cavity or a telescopic cavity wall, in the present case, 10 volume cavity modules with a volume range of 5-18L (volumes of 5L, 6L, 7L, 8L, 9L, 10L, 12L, 14L, 16L, and 18L) are set to adapt to different sizes or batches of molds to be stripped, the cavity body is in the shape of a pot, and the openable and closable cavity cover is connected to the cavity body through an adjustable hinge; A rack, which is fixedly connected to the cavity body through plane bolts, the bottom of the rack is provided with a movable wheel set to facilitate the replacement of the volume cavity module; A vacuum system, which includes a vacuum pump, a vacuum gauge and a KF vacuum interface, the KF vacuum interface is welded to the outer wall of the cavity body, and is used to maintain the vacuum degree in the cavity to be ≤10Pa; A gas supply system, which includes a strong oxidizing reaction gas source, a mass flow meter and a mosquito-imitating gas distributor, the bottom surface of the gas distributor is provided with capillary holes for uniformly introducing reaction gas; A radio frequency power supply unit is configured to provide high-frequency current with an output frequency range of 10-18 MHz. The current output end of the radio frequency power supply is connected to the conductor arranged in the cavity. The power of the radio frequency power supply is dynamically adjusted according to the cavity volume. When the cavity aperture increases by 50%, the power of the radio frequency power supply is adjusted by 20-40%. As shown in Figure 1 、 Figure 2 the connection details of the conductor structure arranged in the cavity and the radio frequency power supply, the specific structure is as follows: a hole is formed in the middle bottom of the cavity body, a metal pipe 5 is fixed in the hole, a fixed base 4 is arranged above the hole in the cavity body, the fixed base 4 is bolted to the bottom of the cavity, an insulating layer 3 is arranged on the fixed base 4, and the insulating layer 3 is connected to the fixed base 4 through a non-circular center bolt. The conductor arranged in the cavity is a conductor disc with two layers, the conductor disc is fixed on the insulating layer 3, the upper layer of the conductor disc is a flat top plate 1 for placing a mold, and the lower layer of the conductor disc is a substrate 2. A conductor rod 6 is fixed at the center of the substrate 2 through a conductor bolt. The sealing between the conductor rod 6 and the bottom of the cavity adopts a composite sealing mode of an interference fit of a sealing plastic block 7, a sealing glue 9, and a vacuum sealing clamp (the position of the vacuum sealing clamp is at position 10 in Figure 2 ). An insulating sleeve is sleeved on the upper end of the conductor rod 6 to avoid conduction with the cavity. The lower end of the conductor rod 6 penetrates the insulating layer 3, the fixed base 4, the metal pipe 5 fixed in the bottom hole of the cavity, and then is connected to the current output end of the radio frequency power supply of the radio frequency power supply unit through a vacuum pipe joint 8.

[0017] A control unit is electrically connected to the vacuum system, the gas supply system, and the radio frequency power supply unit, and is configured to monitor the cavity volume, the vacuum degree, the temperature, and the plasma current in real time, and dynamically control the radio frequency power supply frequency, the gas flow, the reaction temperature, and the time through a specific algorithm to match the cavity volume change. Ten sets of process parameter templates and PID algorithms corresponding to different volumes (5L, 6L, 7L, 8L, 9L, 10L, 12L, 14L, 16L, 18L) are provided.

[0018] The application will be further described below in combination with specific experimental examples and comparative examples.

[0019] Example 1 I. Basic conditions of the experiment Mold to be treated: circular metal mold (material: 45 steel), surface deposited diamond-like carbon film (DLC), film thickness 5±0.5 μm, diameter 100 mm (small), 200 mm (medium), and 300 mm (large).

[0020] The traditional equipment used in the comparative example is a fixed volume device (10L cavity, radio frequency power supply frequency 13.56 MHz, oxygen flow 100sccm, duty cycle 50%).

[0021] The device used in the experimental example: variable volume cavity (5L / 10L / 16L) + dynamic parameter control system (PLC control unit, 10 sets of volume-parameter matching algorithm + PID algorithm built-in).

[0022] Evaluation index: film stripping efficiency (pm / min), surface roughness Ra (pm), energy consumption (kWh / piece), and qualified rate (% with film layer residual rate ≤5% as qualified).

[0023] II. Experimental example design Experimental example 1: small mold (diameter 100 mm) + 5L cavity Cavity volume: 5L (adapted to small mold).

[0024] Dynamic parameter setting (calculated according to cavity volume 5L and the above volume-parameter matching algorithm): Radio frequency: f = 13 + 0.2 x (5-10) = 12 MHz; Plasma current: I = 0.6 + 0.04 x 5 = 0.8 A; Oxygen flow: Q = 10 x 5 = 50 sccm; Duty cycle: D = 50 + 1 x (5-10) = 45%, Reaction temperature: T = 200-2 x (5-10) = 210℃; Reaction time: t = 25 + 0.5 x (5-10) = 22.5 min; Processing process:

[0025] Vacuum to 8 Pa, oxygen is introduced and stabilized for 7 minutes; Turn on the radio frequency power (initial power 180W), PID algorithm real-time fine tuning (current deviation (0.8A-real-time current) ≤±0.05A, ΔQ ≤±2sccm; temperature deviation (210℃-real-time temperature) ≤±5℃, ΔP ≤±10W); Stop every 30 minutes to observe, stop for 8 minutes; total cycle 2 times (total processing time: 30min+8min+15min=53min, effective reaction time 22.5min+15min=37.5min).

[0026] Experimental results: Film stripping time: 37.5min, efficiency: 0.13pm / min; Surface roughness Ra: 0.08pm; Energy consumption: 0.8kWh / piece; Yield: 100% (no residue on film, no corrosion on substrate).

[0027] Experimental Example 2: Medium-sized mold (diameter 200 mm) + 10L cavity Cavity volume: 10L (adapted to medium-sized mold).

[0028] Dynamic parameter settings (calculated according to cavity volume 10L and the above volume-parameter matching algorithm): Radio frequency: f = 13 MHz; Plasma current: I = 0.6 + 0.04 x 10 = 1.0 A; Oxygen flow rate: Q = 100 sccm; Duty cycle: D = 50%; Reaction temperature: T = 200°C; Reaction time: t = 25 min; Process:

[0029] Vacuum to 6 Pa, oxygen is introduced and stabilized for 6 minutes; Turn on the radio frequency power (initial power 200W), PID algorithm real-time fine-tuning (current deviation (1.0A-real-time current) ≤±0.05A, ΔQ ≤±3sccm; temperature deviation (200°C-real-time temperature) ≤±5°C, ΔP ≤±8W).

[0030] Stop every 30 minutes to observe, stop for 5 minutes; a total of 2 cycles (total processing time: 30min+5min+15min=50min, effective reaction time 25min+15min=40min).

[0031] Experimental results: Film removal time: 40 min, efficiency: 0.125 μm / min; Surface roughness Ra: 0.09 μm; Energy consumption: 1.2 kWh / piece; Yield: 100%.

[0032] Experimental Example 3: Large mold (diameter 300 mm) + 16L cavity Cavity volume: 16L (adapted to large mold, no need to split processing).

[0033] Dynamic parameter settings (calculated according to cavity volume 16L and the above volume-parameter matching algorithm): Radio frequency: f = 13 + 0.2 x (16-10) = 14.2 MHz; Plasma current: I = 0.6 + 0.04 x 16 = 1.24 A; Oxygen flow rate: Q = 10 x 16 = 160 sccm; Duty cycle: D = 50 + 1 x (16 - 10) = 56%, Reaction temperature: T = 200 - 2 x (16 - 10) = 188℃; Reaction time: t = 25 + 0.5 x (16 - 10) = 28 min; Process:

[0034] Vacuum to 7 Pa, and then oxygen was introduced for 8 minutes; The radio frequency power was turned on (initial power 220 W), and the PID algorithm was used for real-time fine tuning (current deviation (1.24 A - real-time current) ≤ ± 0.08 A, ΔQ ≤ ± 4 sccm; temperature deviation (188℃ - real-time temperature) ≤ ± 5℃, ΔP ≤ ± 12 W). The process was stopped every 30 minutes for observation, and the machine was stopped for 10 minutes; the total processing time was 2 cycles (30 min + 10 min + 15 min = 55 min, effective reaction time 28 min + 15 min = 43 min).

[0035] Experimental results: Film removal time: 43 min, efficiency: 0.116 μm / min; Surface roughness Ra: 0.10 μm; Energy consumption: 1.8 kWh / piece; Pass rate: 98% (3% residual rate at local corners, which meets the standard).

[0036] III. Design of Comparative Examples Comparative Example 1: Traditional fixed volume equipment processing different size molds Experimental conditions: 10 L fixed cavity was used, and the parameters were fixed (oxygen flow rate 100 sccm, frequency 13.56 MHz), and small, medium and large molds were processed respectively.

[0037] The experimental results are shown in Table 1.

[0038] Table 1: Results of traditional fixed volume equipment processing different size molds

[0039] As can be seen, the energy consumption is high (1.5 kWh vs. 0.8 kWh of Example 1) when the fixed volume equipment processes small molds, the efficiency is low (0.04 μm / min vs. 0.09 μm / min of Example 3) when it processes large molds, and the surface quality is poor (Ra > 0.15 μm).

[0040] Comparative Example 2: variable volume but no dynamic parameter regulation (fixed parameters) Experimental conditions: a 16L cavity was used to process large molds (300mm in diameter), but the parameters were fixed at 100sccm oxygen flow and 13.56MHz frequency, i.e. the processing parameters were not scaled proportionally with the volume.

[0041] Experimental results: Film removal time: 90min, efficiency: 0.06μm / min (due to insufficient oxygen flow, low plasma concentration); Surface roughness Ra: 0.18μm (local film layer residue); Pass rate: 60% (residual rate >10%).

[0042] As can be seen, without dynamic parameter regulation, even if the volume is adapted, the film removal effect cannot be guaranteed, which reversely verifies the necessity of "volume-parameter linkage".

[0043] Comparative Example 3: dynamic parameter regulation + PID algorithm fine-tuning but fixed volume Experimental conditions: a 10L fixed cavity was used to process 300mm large molds (mold size exceeds the cavity adaptation range), and the dynamic parameters were set according to the 10L volume (oxygen flow 100sccm, frequency 13.56MHz).

[0044] Experimental results: Film removal time: 85min, efficiency: 0.06μm / min (plasma distribution is uneven at the edge and center of the mold); Surface roughness Ra: 0.22μm (over-etching at the edge and residue at the center); Energy consumption: 2.5kWh / piece (due to repeated parameter adjustment, energy consumption increases); Pass rate: 50%.

[0045] As can be seen, fixed volume cannot adapt to large-size molds, and dynamic parameter regulation cannot compensate for the uniformity problem caused by space mismatch.

[0046] Finally, it should be noted that the terms "comprise", "contain" or any other variant thereof are intended to cover non-exclusive inclusion, so that processes, film removal methods, articles or efficient film removal devices comprising a series of elements include not only those elements, but also other elements not explicitly listed or inherent to such processes, film removal methods, articles or efficient film removal devices. Although preferred embodiments of the present application have been described, those skilled in the art can make additional changes and modifications to these embodiments once they understand the basic inventive concept. Therefore, the appended claims are intended to cover the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0047] The above embodiments only express the specific implementation of the present application, which is described in more detail and specifically, but it should not be understood as a limitation to the protection scope of the present application. It should be noted that for those skilled in the art, without departing from the technical concept of the present application, a number of modifications and improvements can be made, which are all within the protection scope of the present application.

Claims

1. A high-efficiency demolding device based on a carbon film layer on the surface of a mold using a variable-volume cavity, characterized in that, include: The variable volume cavity module consists of a cavity body and an openable cavity cover. The volume of the cavity body can be dynamically adjusted by replacing the modular cavity or the telescopic cavity wall to adapt to molds of different sizes or batches. The frame is fixedly connected to the cavity body by flat bolts, and the bottom of the frame is provided with a set of movable wheels; The vacuum system includes a vacuum pump, a vacuum gauge, and a KF vacuum interface. The KF vacuum interface is welded to the outer wall of the cavity body and is used to maintain the vacuum level inside the cavity ≤10Pa. The gas supply system includes a strong oxidizing gas source, a mass flow meter, and a mosquito coil-shaped gas distributor. The bottom surface of the gas distributor has capillary holes for uniformly introducing the reaction gas. The radio frequency (RF) power supply unit provides high-frequency current with an output frequency range of 10-18MHz. The current output terminal of the RF power supply is connected to a conductor located inside the cavity. Its power is dynamically adjusted according to the cavity volume. The adjustment relationship is as follows: when the cavity diameter increases by 50%, the power of the RF power supply is increased by 20-40%. The control unit is electrically connected to the vacuum system, gas supply system, and radio frequency power supply unit. It is used to monitor the cavity volume, vacuum level, temperature, and plasma current in real time, and dynamically adjust the radio frequency power supply frequency, gas flow rate, reaction temperature, and time through a specific algorithm to match changes in cavity volume.

2. The high-efficiency film removal equipment as described in claim 1, characterized in that, The variable volume cavity module has a volume range of 5~18L. The cavity body is pot-shaped, and the openable cavity cover is connected to the cavity body via an adjustable hinge.

3. The high-efficiency film removal equipment as described in claim 1, characterized in that, The cavity body has a bottom opening in the middle, and a metal tube is fixed inside the bottom opening. A fixed base is also located inside the cavity body above the bottom opening. The fixed base is bolted to the bottom of the cavity. An insulating layer is provided on the fixed base, which is connected to the fixed base via bolts at non-central positions. The conductor inside the cavity consists of two layers of conductor discs, fixed to the insulating layer. The upper layer of the conductor discs is a flat top plate for placing the mold, and the lower layer is a substrate. A conductor rod is fixed to the center of the substrate via conductor bolts. The conductor rod is sealed to the bottom of the cavity using a composite sealing method of interference fit with a plastic block, sealant, and vacuum sealing clamp. An insulating sleeve is fitted over the upper end of the conductor rod to prevent it from conducting through the cavity. The lower end of the conductor rod passes through the insulating layer, the fixed base, and the metal tube fixed inside the bottom opening of the cavity before connecting to the RF power supply current output terminal of the RF power supply unit.

4. The high-efficiency film removal equipment as described in claim 1, characterized in that, The control unit is a PLC control system with a touch screen, which has a built-in volume-parameter matching algorithm and stores at least 10 sets of process parameter templates corresponding to different volumes of the algorithm. The volume-parameter matching algorithm is as follows: The radio frequency power supply frequency f = 13 + 0.2×(V - 10); Plasma current I = 0.6 + 0.04 × V; Oxygen flow rate Q = 10 × V; The reaction temperature T = 200 - 2×(V - 10); The effective reaction time for a single cycle is t = 25 + 0.5 × (V - 10); Duty cycle D = 50 + 1×(V - 10); In the above formulas, V is the cavity volume in L; f is the radio frequency power supply frequency in MHz. I is the plasma current, in A; Q is the oxygen flow rate, in sccm; T is the reaction temperature, in °C; t is the effective reaction time in a single cycle, in min; D is the duty cycle, in %.

5. A method for removing carbon film from the surface of a mold, characterized in that, Demolding using the high-efficiency demolding equipment as described in any one of claims 1 to 4 includes the following steps: (1) Cavity volume adaptation: Select or adjust the volume of the variable volume cavity module according to the size and batch of the mold to be demolded; (2) Vacuum environment construction: Place the mold to be demolded on the conductor plate in the cavity, close the cavity cover, and evacuate the cavity to a pressure ≤10Pa using the vacuum system; (3) Dynamic parameter control: Input the cavity volume, and the control unit automatically adjusts or manually inputs process parameters based on the cavity volume. The volume-parameter matching algorithm is as follows: The radio frequency power supply frequency f = 13 + 0.2×(V - 10); Plasma current I = 0.6 + 0.04 × V; Oxygen flow rate Q = 10 × V; The reaction temperature T = 200 - 2×(V - 10); The effective reaction time for a single cycle is t = 25 + 0.5 × (V - 10); Duty cycle D = 50 + 1×(V - 10); In the above formulas, V is the cavity volume in L; f is the radio frequency power supply frequency in MHz. I is the plasma current, in A; Q is the oxygen flow rate, in sccm; T is the reaction temperature, in °C; t is the effective reaction time in a single cycle, in min; D is the duty cycle, in %. (4) Plasma reaction: A strong oxidizing reaction gas is introduced into the vacuum chamber and stabilized for a period of time. The radio frequency power supply is turned on to ionize the reaction gas into charged plasma, which is then used to bombard the carbon film layer on the surface of the mold in a directional manner. Through physical and chemical reactions, the carbon atoms are vaporized and discharged with the vacuum system. (5) Real-time feedback adjustment: Monitor the plasma current and temperature inside the cavity, and fine-tune the gas flow rate and radio frequency power through a PID algorithm to ensure uniform film removal. The PID algorithm is as follows: Plasma current deviation e I = I0 - I t ; reaction temperature deviation e T = T0 - T t ; Oxygen flow rate fine-tuning amount ΔQ = Kp1×e I + Ki1×∫e I dt + Kd1×(de I / dt), where Kp1=5, Ki1=0.2, Kd1=0.5; RF power fine-tuning ΔP = Kp²×e T + Ki2×∫e T dt + Kd2×(de T / dt), where Kp2=3, Ki2=0.1, Kd2=0.3; In the above formulas, I0 is the initially calculated plasma current, in amperes (A); I t To measure plasma current in real time, in A; T0 is the initially calculated reaction temperature, in °C; T t For real-time detection of reaction temperature, the unit is °C; Kp1, Ki1, and Kd1 are the proportional, integral, and differential coefficients for oxygen flow rate fine-tuning; Kp2, Ki2, and Kd2 are the proportional, integral, and differential coefficients for radio frequency power fine-tuning; ΔQ is the oxygen flow rate fine-tuning amount, in sccm; ΔP is the radio frequency power fine-tuning amount, in W. (6) Cycle and termination: Stop the reaction every 30 minutes and observe the film removal effect. After a 5-10 minute break, repeat steps (3)-(5) until all or most of the carbon film layer is removed. Turn off the RF power supply, open the exhaust valve to release the gas in the cavity, and open the cavity cover to remove the mold.

6. The demolding method as described in claim 5, characterized in that, The strong oxidizing gas is oxygen.

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