An ion energy screening device and method

Abstract

An ion energy screening device and method includes: a pre-stage fixedly connected to the head of an insulating sleeve; n insulating rings and perforated grids spaced axially along the inner side of the insulating sleeve, forming a multi-cavity assembly; multiple through holes machined on the perforated grid as mesh openings for plasma passage; a collecting electrode also installed on the inner side of the insulating sleeve, located at the rear end of the multi-cavity assembly; an end cap fixedly connected to the tail of the insulating sleeve, used to seal the tail of the insulating sleeve; the collecting electrode for collecting screened ions; and a ceramic gasket fitted onto the outer side of the end cap. This invention achieves the effect of ion screening and electron exclusion by applying different voltages to multiple perforated grids. It can also control the acquisition of ions with a specific ion energy range. In vacuum ion plating processes, it can be used to detect the ion energy range and control the ion energy to obtain films with different physical properties.

Description

Technical Field

[0001] This invention relates to an ion energy screening device and method, belonging to the field of machining technology. Background Technology

[0002] With the continuous development of ion technology, plasma coating technology is being used more and more widely. This process involves bombarding the surface of a material with a high-energy ion beam, causing a chemical reaction to form a film. The resulting film has a dense structure, uniform thickness, and excellent physical and chemical properties.

[0003] In plasma coating processes, insufficient ion energy screening often results in inaccurate ion distribution on the part surface, leading to low film density and low hardness. Therefore, it is necessary to design an ion energy screening device to improve the quality and performance of the coating. Summary of the Invention

[0004] The technical problem solved by the present invention is: In order to overcome the shortcomings of the prior art, the present invention proposes an ion energy screening device and method, which can efficiently screen ions of specified energy, thereby improving the film density of the product and obtaining a superior film.

[0005] The technical solution provided by this invention is as follows:

[0006] Firstly,

[0007] An ion energy screening device includes: a pre-stage, an insulating ring, an insulating sleeve, a perforated grid, a collecting electrode, an end cap, and a ceramic gasket;

[0008] The head of the insulating sleeve is fixedly connected to a preamplifier, and the top of the preamplifier is machined with a through hole for plasma to pass through.

[0009] The inner side of the insulating sleeve is provided with n insulating rings and perforated grids spaced axially, and the n insulating rings and perforated grids form a multi-cavity assembly; the n insulating rings are used to axially limit the n perforated grids.

[0010] The grating has multiple through holes as mesh openings to allow plasma to pass through;

[0011] An collecting electrode is also installed on the inner side of the insulating sleeve. The collecting electrode is located at the rear end of the multi-cavity assembly. An end cap is fixedly connected to the tail of the insulating sleeve. An insulating ring is also provided between the end cap and the collecting electrode. The end cap is used to close the tail of the insulating sleeve.

[0012] The collecting electrode is used to collect the ions after sieving;

[0013] The ceramic gasket is fitted on the outside of the end cap and is used to limit and adjust the axial position of the end cap and the insulating sleeve for fixed connection.

[0014] The preamp, insulating ring, and insulating sleeve are all made of ceramic, the aperture grid is made of metal, and the end cap is made of brass.

[0015] Preferably, the preamplifier has a hemispherical structure, and the ratio of the diameter of the through hole at the top of the preamplifier to the diameter of the sphere is in the range of 0.3 to 0.6.

[0016] Preferably, the insulating sleeve and the n+1 insulating rings are clearance-fitted;

[0017] The n+1 insulating rings have the same structural dimensions. The inner diameter of the insulating ring is equal to 70% to 80% of the outer diameter, and the axial thickness of the insulating ring is in the range of 3mm to 6mm.

[0018] Preferably, the thickness of the aperture grid ranges from 0.1 mm to 0.5 mm;

[0019] The multiple meshes of the grating are distributed in a spiral or concentric circle pattern; the porosity ranges from 75% to 95%, and the mesh diameter ranges from 0.5 mm to 2 mm.

[0020] Preferably, the axial spacing between two adjacent aperture grids is in the range of 3mm to 6mm.

[0021] Preferably, the ratio of the inner diameter to the outer diameter of the insulating sleeve is in the range of 0.7 to 0.9.

[0022] Preferably, the collecting electrode is removable, so that the collecting electrode can be replaced with the workpiece to be coated for plasma coating.

[0023] Secondly,

[0024] A method for testing ion current density using an ion energy screening device as described in the first aspect includes the following steps:

[0025] 1) Apply 0V voltage to aperture a, apply negative bias voltage to aperture b and aperture d, and apply a triangular waveform scanning positive voltage to aperture c; wherein, the negative bias voltage applied to aperture b is higher than the negative bias voltage applied to aperture d.

[0026] 2) Start the external ion source and let the plasma pass through the pre-stage and multi-cavity assembly in sequence, then measure the current value at the collecting electrode;

[0027] 3) Increase the range of the triangular waveform scanning positive voltage applied to the aperture grid c, and measure the current value at the collector electrode again;

[0028] 4) Repeat step 3) continuously increase the range of the triangular waveform scanning positive voltage applied to the aperture grid c until the current value at the collector is 0, then proceed to step 5);

[0029] 5) Obtain the current value of the collecting electrode when applying a scanning positive voltage of triangular waveform with different ranges to the aperture gate c as the corresponding ion current density.

[0030] Thirdly,

[0031] A method for plasma coating a workpiece involves replacing the collector electrode with the workpiece and using an ion energy screening device as described in the first aspect to screen out ions of a specified energy, thereby performing plasma coating on the workpiece.

[0032] The advantages of this invention compared to the prior art are:

[0033] 1) This invention achieves the filtering effect of electrons and low-energy ions through a multi-layer pore grid combination. It effectively improves the screening speed, provides simple and easy-to-implement results, and is economical and practical as it does not rely on complex detection systems.

[0034] 2) This invention achieves electron filtering, low-energy ion filtering, specific energy range ion filtering, and secondary electron filtering effects by applying different voltages to each layer of the pore grid. This maximizes the elimination of interference from electrons, low-energy ions, and secondary electrons. Attached Figure Description

[0035] Figure 1 This is a cross-sectional view of the ion energy screening device in an embodiment of the present invention;

[0036] Figure 2 This is a schematic diagram of the ion energy screening device in an embodiment of the present invention;

[0037] Figure 3 This is a schematic diagram of the front-end structure in an embodiment of the present invention;

[0038] Figure 4 This is a schematic diagram of the insulating ring structure in an embodiment of the present invention;

[0039] Figure 5 This is a schematic diagram of the insulating sleeve in an embodiment of the present invention;

[0040] Figure 6 This is a schematic diagram of the structure of the aperture grid in an embodiment of the present invention;

[0041] Figure 7 This is a schematic diagram of the collecting electrode structure in an embodiment of the present invention;

[0042] Figure 8 This is a schematic diagram of the end cap structure in an example of the present invention. Detailed Implementation

[0043] The present invention will be further illustrated below with reference to examples, but this does not limit the present invention to the scope of the described embodiments.

[0044] The present invention provides an ion energy screening device, comprising: a pre-stage 1, an insulating ring, an insulating sleeve 7, a perforated grid, a collecting electrode 12, an end cap 13, and a ceramic gasket 14.

[0045] The inner side of the insulating sleeve 7 is provided with n insulating rings and perforated grids spaced apart along the axial direction. The n insulating rings and perforated grids form a multi-cavity assembly. The n insulating rings are used to limit the n perforated grids axially.

[0046] The grating has multiple through holes, which act as mesh openings to allow plasma to pass through;

[0047] The head of the insulating sleeve 7 is fixedly connected to the preamplifier 1, and the top of the preamplifier 1 is machined with a through hole for plasma to pass through.

[0048] The preamplifier 1 has a hemispherical structure and is made of ceramic material. The top of the preamplifier 1 is machined with a through hole for plasma to pass through. The ratio of the diameter of the through hole to the diameter of the ball is in the range of 0.3 to 0.6. The bottom is machined with external threads and is fixedly connected to the insulating sleeve 7 through the threads.

[0049] An collecting electrode 12 is also installed on the inner side of the insulating sleeve 7. The collecting electrode 12 is located at the rear end of the multi-cavity assembly. An end cap 13 is fixedly connected to the tail of the insulating sleeve 7. An insulating ring is also provided between the end cap 13 and the collecting electrode 12. The end cap 13 is used to close the tail of the insulating sleeve 7.

[0050] Collector 12 is used to collect the screened ions for subsequent analysis and detection.

[0051] The insulating sleeve 7 is clearance-fitted with the n+1 insulating rings;

[0052] The n+1 insulating rings have the same structural dimensions, with the inner diameter being 70% to 80% of the outer diameter, and the axial thickness ranging from 3mm to 6mm.

[0053] The insulating ring is made of ceramic material.

[0054] The ceramic gasket 14 is fitted on the outside of the end cap 13 and is used to limit and adjust the axial position of the end cap 13 and the insulating sleeve 7 for fixed connection.

[0055] The aperture grid is made of a metallic material (such as copper or silver, which have good electrical conductivity); the thickness of the aperture grid ranges from 0.1 mm to 0.5 mm; the multiple apertures of the aperture grid are distributed in a spiral or concentric circle pattern. The porosity ranges from 75% to 95%, and the mesh diameter ranges from 0.5 mm to 2 mm. The aperture grid and insulating ring are installed alternately and sequentially, with the axial spacing between two adjacent aperture grids ranging from 3 mm to 6 mm, to create space for ions to pass through and to prevent cross-contamination of the aperture grid.

[0056] The collecting electrode 12 is replaced with the workpiece to be coated, thereby performing plasma coating on the workpiece. The collecting electrode 12 is a detachable device and can be replaced with the part to be coated.

[0057] The preamplifier 1 and the insulating sleeve 7 are connected and fixed by a threaded connection.

[0058] The insulating sleeve 7 and the end cap 13 are connected and fixed by a threaded connection, and the entire ion screening device forms a cavity structure of a multi-level pore grid.

[0059] The end cap 13 is made of brass and has a two-stage stepped shaft structure with a through hole in the middle for the tail wire to pass through. It is machined with external threads to mate with the insulating sleeve 7. Figure 8 As shown, the end cap 13 has a structure where the outer diameter of the large-section stepped outer circle is the same as the outer diameter of the insulating sleeve 7, and the outer diameter of the small-section stepped outer circle is the same as the inner diameter of the insulating sleeve 7.

[0060] The insulating sleeve 7 is made of ceramic, with threads machined on the inner sides of its head and tail, connecting to the front stage 1 and end cap 13 via these threads. Figure 5 As shown, the ratio of the inner diameter to the outer diameter of the insulating sleeve 7 ranges from 0.7 to 0.9.

[0061] In this embodiment of the invention, insulating rings a2, b3, c4, and d5 are made of ceramic material, and the outer ends of the rings have grooves to provide a passage for the tail wire.

[0062] A method for testing ion current density using an ion energy screening device involves connecting wires to the terminals of aperture grids a8, b9, c10, and d11, and applying different voltage values ​​to different aperture grids according to actual requirements. The steps include the following:

[0063] 1) Apply 0V to the aperture gate a8, apply negative bias to the aperture gates b9 and d11, and apply a triangular waveform scanning positive voltage to the aperture gate c10; wherein, the negative bias applied to the aperture gate b9 is higher than the negative bias applied to the aperture gate d11.

[0064] 2) Start the ion source. After the plasma passes through the pre-stage 1 and the multi-cavity assembly in sequence, measure the current value at the collecting electrode 12.

[0065] 3) Increase the range of the triangular waveform scanning positive voltage applied to the aperture gate c10 by step size, and measure the current value at the collector 12 again;

[0066] 4) Repeat step 3) continuously increase the range of the triangular waveform scanning positive voltage applied to the aperture gate c10 by step size until the current value of the collector 12 is 0, then proceed to step 5).

[0067] 5) Obtain the current value of the collector 12 under different ranges of triangular waveform scanning positive voltage applied to the aperture gate c10 as the corresponding ion current density.

[0068] In this embodiment of the invention, in step 1), a 0V voltage is applied to the aperture gate a8, a -45V negative bias voltage is applied to the aperture gate b9, and a -80V negative bias voltage is applied to the aperture gate d11. In step 1), a scanning positive voltage with a triangular waveform within a range of 10V is applied to the aperture gate c10 for the first time, and the obtained current value is the ion current density with ion energy greater than 10eV. A scanning positive voltage with a triangular waveform within a range of 20V is applied to the aperture gate c10 for the second time, and the obtained current value is only the ion current density with ion energy greater than 20eV. The range of the aperture gate c10 is increased by a step size ΔV = 10 in two adjacent tests. This process is repeated to obtain the ion energy density of each energy range.

[0069] The collecting electrode 12 is replaced with the part to be processed, and the ion energy screening device described above is used to screen out ions of a specified energy, thereby performing plasma coating on the part to be processed.

[0070] This invention achieves the effect of excluding electrons and screening ions by applying different voltages to multiple pore gates. Furthermore, it can control the acquisition of ions within a specific energy range. In the vacuum ion plating process, it can be used both to detect the ion energy range and to control the ion energy to obtain films with different physical properties.

[0071] Figure 1 The image shows a cross-sectional view of the ion energy screening device in an embodiment of the present invention. In this example, the ion screening device includes: a pre-stage 1, insulating rings, a perforated grid, a collecting electrode 12, and an end cap 13. The insulating rings include: insulating ring a2, insulating ring b3, insulating ring c4, insulating ring d5, insulating ring e6, and an insulating sleeve 7. The perforated grids include: perforated grid a8, perforated grid b9, perforated grid c10, and perforated grid d11. In one embodiment of the present invention, four perforated grids and four insulating rings are installed alternately, and the perforated grids and insulating rings are installed in the following order: perforated grid a8, insulating ring a2, perforated grid b9, insulating ring b3, perforated grid c10, insulating ring c4, perforated grid d11, insulating ring d5, collecting electrode 12, and insulating ring e6.

[0072] The edges of aperture grids a8, b9, c10, and d11 are respectively provided with terminals. The ceramic gasket 14 is machined with through holes, which allow the tail wires of aperture grids a8, b9, c10, and d11 to pass through the through holes.

[0073] Figure 2 The diagram shown is a structural schematic of the ion energy screening device in an embodiment of the present invention.

[0074] Figure 3The diagram shown is a schematic diagram of the front stage in an embodiment of the present invention. The front stage 1 is a hemispherical structure made of stainless steel. The top of the hemisphere has a through hole 11, and the bottom has machined threads to cooperate with the insulating sleeve 7.

[0075] Figure 4 The diagram shown is a schematic representation of the insulating ring in an embodiment of the present invention. The insulating ring a2 is made of ceramic, and the perforated grid is spaced apart to prevent cross-current. A groove 21 is provided at the outer end of the ring; this design provides a corresponding tail wire path for the perforated grid where the required voltage is applied. The outer diameter of the insulating ring a2 and the insulating sleeve 7 are in clearance fit. k -d jyh ≥5, D k d is the outer diameter of the aperture grid. jyh This is the inner diameter of the insulating ring.

[0076] Figure 5 The diagram shown is a structural schematic of the insulating sleeve in an embodiment of the present invention. Both ends of the insulating sleeve 7 are threaded and connected to the front stage and the end cap, respectively.

[0077] like Figure 6 The diagram shows the structure of aperture grid a8. Aperture grid 8 is a circular sheet structure with an insulating ring separating two aperture grids. Numerous through holes 81 are drilled on it to facilitate the passage of sieved ions. In one embodiment of the invention, the multiple meshes of the aperture grid are arranged in a spiral pattern. A first terminal 82 and a second terminal 83 are provided on aperture grid a8. A tail wire is connected to these terminals to apply a corresponding voltage to the aperture grid.

[0078] Figure 7 The diagram shown is a schematic representation of the collecting electrode in an embodiment of the present invention. The collecting electrode 12 is made of brass and is used to collect the screened ions; it can be replaced with a component to be processed.

[0079] Figure 8 The diagram shows the structure of the end cap in this embodiment of the invention. The end cap 13 is machined into a circular cap-shaped structure and is threadedly connected to the insulating sleeve 7, forming an almost sealed space for the entire ion screening device.

[0080] The method of using the ion screening device is as follows:

[0081] The material and ion screening device are placed in a vacuum chamber. The material is ionized to form an ion beam, which is then injected into the ion screening device through the top through-hole of the pre-stage 1. Equal amounts of ions and electrons initially pass through the aperture grid a8 with a 0V applied and enter the insulating ring a2. A negative bias voltage of -45V is applied to the aperture grid b9 to suppress the electrons entering the ion screening device, allowing the ions to pass through the holes into the insulating ring b3. A scanning positive voltage with a triangular waveform in the range of 0-60V is applied to the aperture grid c10. The varying voltage is used to filter ions with different kinetic energies. Only ions with kinetic energies greater than the product of the voltage on aperture grid c10 and the ion charge can overcome the repulsive force generated by the potential difference and thus pass through aperture grid c10 into the insulating ring c4. A negative bias voltage of -80V is applied to the aperture grid d11 to suppress secondary electrons and apply an attractive force to the ions that have passed through the screening, ensuring that the ions can quickly and effectively reach the collecting electrode 12. The collecting electrode 12 detects and analyzes the energy distribution of the ions passing through the ion screening device.

[0082] The collector electrode 12 can be disassembled and replaced with the part to be processed, and the ion energy can be controlled to obtain a film with different physical properties.

[0083] In summary, the ion energy screening device in this embodiment, combined with the characteristics of vacuum ion plating, utilizes a multi-level porous grid structure to achieve electron repulsion and ion screening. This allows for more precise acquisition of ions within a specific energy range, overcoming the problem of insufficient film performance on the parts to be processed, and improving plating efficiency and film density. This ion energy screening device not only enables ion plating but also detects and analyzes the ion energy distribution, allowing for more effective and targeted improvement of film performance.

[0084] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. An ion energy screening device, characterized in that, include: The preamplifier (1), insulating ring, insulating sleeve (7), perforated grid, collecting electrode (12), end cap (13) and ceramic gasket (14). The head of the insulating sleeve (7) is fixedly connected to the preamplifier (1), and the top of the preamplifier (1) is machined with a through hole for allowing plasma to pass through. The inner side of the insulating sleeve (7) is provided with multiple insulating rings and perforated grids at axial intervals, and the multiple insulating rings and perforated grids form a multi-cavity assembly; the insulating rings are used to limit the perforated grids axially; The grating has multiple through holes as mesh openings to allow plasma to pass through; An collecting electrode (12) is also installed on the inner side of the insulating sleeve (7). The collecting electrode (12) is located at the rear end of the multi-cavity assembly. An end cap (13) is fixedly connected to the tail of the insulating sleeve (7). An insulating ring is also provided between the end cap (13) and the collecting electrode (12). The end cap (13) is used to close the tail of the insulating sleeve (7). The collecting electrode (12) is used to collect the ions after sieving; The ceramic gasket (14) is fitted on the outside of the end cap (13) to limit and adjust the axial position of the end cap (13) and the insulating sleeve (7) for fixed connection.

2. The ion energy screening device according to claim 1, characterized in that, The preamplifier (1) has a hemispherical structure, and the ratio of the diameter of the through hole at the top of the preamplifier (1) to the diameter of the ball is 0.3 to 0.

6.

3. The ion energy screening device according to claim 1, characterized in that, The insulating sleeve (7) and the insulating ring are fitted with a clearance. The multiple insulating rings have the same structural dimensions, with the inner diameter of the insulating ring being 70% to 80% of the outer diameter, and the axial thickness of the insulating ring ranging from 3mm to 6mm.

4. The ion energy screening device according to claim 1, characterized in that, The preamp (1), insulating ring and insulating sleeve (7) are all made of ceramic material, the perforated grid is made of metal material, and the end cap (13) is made of brass.

5. An ion energy screening device according to any one of claims 1 to 4, characterized in that, The thickness of the aperture grid ranges from 0.1 mm to 0.5 mm; The multiple meshes of the grating are distributed in a spiral or concentric circle pattern; the porosity ranges from 75% to 95%, and the mesh diameter ranges from 0.5 mm to 2 mm.

6. The ion energy screening device according to claim 5, characterized in that, The axial spacing between two adjacent aperture grids ranges from 3mm to 6mm.

7. The ion energy screening device according to claim 6, characterized in that, The ratio of the inner diameter to the outer diameter of the insulating sleeve (7) is in the range of 0.7 to 0.

9.

8. The ion energy screening device according to claim 7, characterized in that, The collecting electrode (12) can be removed so that the collecting electrode (12) can be replaced with the workpiece to be coated and plasma coated on the workpiece.

9. A method for testing ion current density using an ion energy screening device according to claim 7, characterized in that, The steps include the following: 1) Apply 0V voltage to aperture a (8), apply negative bias voltage to aperture b (9) and aperture d (11), and apply a triangular waveform scanning positive voltage to aperture c (10); wherein, the negative bias voltage applied to aperture b (9) is higher than the negative bias voltage applied to aperture d (11); 2) Start the ion source. After the plasma passes through the pre-stage (1) and the multi-cavity assembly in sequence, measure the current value at the collecting electrode (12). 3) Increase the range of the triangular waveform scanning positive voltage applied to the aperture gate c (10) and measure the current value at the collector (12) again; 4) Repeat step 3) continuously increase the range of the triangular waveform scanning positive voltage applied to the aperture gate c (10) until the current value at the collector (12) is 0, then proceed to step 5). 5) Obtain the current value of the collector (12) when different ranges of triangular waveform scanning positive voltage are applied to the aperture gate c (10) as the corresponding ion current density.

10. A method for plasma coating of parts to be processed, characterized in that, The collecting electrode (12) is replaced with the part to be processed, and the ion energy screening device as described in claim 8 is used to screen out ions of a specified energy, thereby performing plasma coating on the part to be processed.

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