Method for predicting and regulating thickness distribution uniformity of complex curved surface magnetron sputtering coating

Abstract

The application discloses a complex curved surface magnetron sputtering coating thickness distribution uniformity prediction and control method, comprising the following steps: step 1, discretizing a complex curved surface model and a sputtering target model respectively; step 2, calculating the theoretical coating thickness of each three-dimensional grid unit when the sputtering target is at the current position and without considering the spatial shielding effect; step 3, considering the spatial shielding relationship formed by the complex curved surface, correcting the obtained theoretical coating thickness; step 4, repeating the steps 2-3 process for multiple moving positions of the sputtering target, and combining the sputtering time proportion of each moving position to perform weighted superposition, to obtain the coating thickness distribution of the complex curved surface; and step 5, calculating the coating thickness uniformity evaluation index according to the coating thickness distribution, and if the preset requirement is not met, adjusting the moving position and / or the sputtering time proportion until the preset requirement is met. The application can accurately predict the coating thickness distribution of the complex curved surface, and provide a basis for the parameter optimization of the multiple position moving of the sputtering target.

Description

Technical Field

[0001] This invention relates to the field of magnetron sputtering process simulation and design technology, specifically to a method for predicting and controlling the uniformity of thickness distribution in magnetron sputtered coatings on complex curved surfaces. Background Technology

[0002] Magnetron sputtering technology, with its advantages of high deposition rate, strong film-substrate adhesion, and good coating density, is widely used in the preparation of functional coatings on various substrate surfaces. With the development of the manufacturing industry, some complex curved workpieces have placed stringent requirements on the uniformity of coating thickness. The uniformity of coating thickness distribution affects the surface coating quality and performance of the workpiece, thereby impacting its performance in use.

[0003] In magnetron sputtering deposition, sputtered particles are ejected primarily along specific directions, resulting in significant spatial non-uniformity in their spatial distribution. When the surface to be deposited is a complex curved surface with features such as grooves, steps, and local undulations, the local protrusions can obstruct the transport path of sputtered particles, creating shadows. This leads to lower deposition rates in areas such as the bottom of pits, sidewalls, and inner cavities compared to the outer surface and convex areas. This uneven thickness distribution caused by geometric obstruction is a technical challenge that is difficult to solve through simple parameter adjustments.

[0004] Currently, the main methods for analyzing and controlling the thickness distribution of magnetron sputtered coatings include the following categories:

[0005] The first category is thickness analysis and prediction methods based on analytical models. These methods typically establish a film thickness distribution model based on the distance from the target to the substrate surface and the relative position of the substrate, making them suitable for predicting film thickness on planar or simple convex curved substrates. For spherical or hemispherical substrates, some studies have extended the planar model by introducing geometric projection relationships. However, these analytical models all assume that the substrate surface is unobstructed, assuming an effective straight deposition path exists between the sputtering target and a local area of ​​the surface to be coated, and cannot handle complex geometric configurations containing pits, deep holes, or free-form surfaces.

[0006] The second category is thickness optimization methods based on substrate motion. These methods discretize the substrate's motion states, such as rotation, revolution, oscillation, or multiple positions, calculate the film thickness contribution of each motion state, and then weight and superimpose them. By optimizing the sputtering time ratio and motion parameters, the uniformity of film thickness is improved. For example, the paper "Simulation of Film Thickness Distribution in Magnetron Sputtering Head Coating," published in the first issue of the *Journal of Northwestern Polytechnical University* in 2002, proposes two simulation methods to improve film thickness uniformity for a head with an approximately axisymmetric spherical surface: fixed-point coating and non-fixed-point coating. In the fixed-point coating method, several fixed-point positions are determined using a regular polyhedron circumscribed on the head, with the center of the magnetron target facing several positions on the outer surface of the head determined by the vertices, face centers, or a combination of both of the regular polyhedron. Sputtering simulation is performed at each fixed-point position with the same time or weight, and the film thickness distributions corresponding to each fixed-point position are superimposed to obtain the total film thickness distribution. Non-fixed-point coating methods utilize the oscillation of the coating head to discretize the entire coating process into a series of oscillation angle states. The coating head rotates during each oscillation angle state to obtain the corresponding annular film thickness distribution. A scaling factor is used to adjust the film thickness contribution at different oscillation angle states; this scaling factor can be understood as the deposition time or contribution weight at different oscillation angles. Finally, the annular film thickness distributions formed at different oscillation angles are superimposed to obtain the total film thickness distribution. This type of method can reflect the influence of the number of fixed points, oscillation angle states, and time ratios on the uniformity of the coating thickness. However, this type of method is mainly applicable to regular curved surfaces or approximately axisymmetric curved surfaces like the coating head. In the calculation of film thickness contribution at each fixed point position or oscillation angle state, it is also assumed that there is an effective deposition path between the sputtering target and the surface to be coated.

[0007] In summary, the shortcomings of existing technologies lie in the fact that both analytical models and substrate motion superposition methods assume an effective deposition path exists between the sputtering target and the surface to be coated when calculating the film thickness contribution at various locations / states. They fail to assess and correct for potential spatial shading caused by the geometric features of complex surfaces. When the surface to be coated is a complex surface with features such as grooves, steps, and local undulations, these local geometric features can obstruct the transport path of sputtered particles. The aforementioned methods fail to recognize this shading effect and include the theoretical deposition contribution of the actually shaded area in the total film thickness distribution, leading to an overestimation of local film thickness predictions and consequently misleading the determination of subsequent uniformity control parameters. Summary of the Invention

[0008] To address the issue of localized coating thickness deviations caused by the lack of consideration for spatial occlusion on complex curved surfaces in existing magnetron sputtering coating thickness distribution prediction methods, this paper proposes a method for predicting and controlling the uniformity of coating thickness distribution on complex curved surfaces. This method considers the impact of spatial occlusion formed by complex curved surfaces on coating thickness, corrects the theoretical coating thickness obtained without considering spatial occlusion, and pre-sets multiple movement positions for the sputtering target, weighting and superimposing the sputtering time ratios at each movement position to obtain the coating thickness distribution on the complex curved surface. Furthermore, it adjusts the movement position of the sputtering target and / or the corresponding sputtering time ratios according to coating thickness uniformity evaluation indicators, calculating and outputting the target path and the optimal time ratio for each position to ensure the uniformity of the coating thickness distribution on the complex curved surface. This provides a basis for determining the combination of multi-position movement parameters of the sputtering target in practical engineering applications.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] A method for predicting and controlling the uniformity of thickness distribution in magnetron sputtered coatings on complex curved surfaces includes the following steps:

[0011] Step 1: Discretize the complex curved surface to be coated into multiple three-dimensional mesh units, discretize the surface of the sputtering target into multiple target micro-elements, and discretize the preset moving path of the sputtering target into several moving positions.

[0012] Step 2: Calculate the theoretical coating thickness of each micro-element of the sputtering target sputtered to each three-dimensional mesh unit when the sputtering target is in its current moving position and without considering the influence of spatial obstruction;

[0013] Step 3: Based on the spatial geometric relationship of the complex surface to be coated, determine whether the connection between each three-dimensional mesh unit and each target micro-element in the current moving position is blocked by other parts of the complex surface to be coated. If blocked, the theoretical coating thickness of the corresponding micro-element is corrected and the corrected thickness is used as the micro-element deposition thickness. If not blocked, the theoretical coating thickness of the micro-element obtained in Step 2 is used as the micro-element deposition thickness.

[0014] The deposition thickness of each three-dimensional mesh element and the corresponding micro-element of all target materials are summed to obtain the corrected coating thickness of each three-dimensional mesh element at the current moving position.

[0015] Step 4: Repeat steps 2-3 for all moving positions on the preset moving path to obtain the corrected coating thickness of all three-dimensional mesh elements at each moving position;

[0016] Based on the sputtering time ratio corresponding to each moving position, the corrected coating thickness of all three-dimensional mesh elements at each moving position is weighted and superimposed to obtain the total coating thickness distribution of the complex curved surface to be coated.

[0017] Step 5: Calculate the coating thickness uniformity evaluation index based on the total coating thickness distribution obtained in Step 4, and determine whether the coating thickness uniformity evaluation index meets the preset requirements: If the preset requirements are met, the current moving position and its corresponding sputtering time ratio are used as the optimal sputtering parameter combination; if the preset requirements are not met, adjust the distribution of moving positions and / or the sputtering time ratio corresponding to each moving position, and repeat Steps 2-4 until the coating thickness uniformity evaluation index meets the preset requirements, and use the moving position and its corresponding sputtering time ratio corresponding to the last iteration as the optimal sputtering parameter combination.

[0018] Furthermore, in step 2, the theoretical coating thickness of the micro-element is calculated using the following formula:

[0019]

[0020] In the formula, The theoretical coating thickness is expressed as the thickness of the micro-element coating formed by the deposition of target atoms sputtered from any micro-element of a circular planar sputtering target onto a three-dimensional mesh element of the complex curved surface to be coated per unit time. The unit is 1. ; The density of target atoms, in units of ; Sputtering rate, in units of ; The emission angle of the target atoms is expressed in degrees (°). The deposition angle of the target atoms, in degrees; The area of ​​the target material element is expressed in units of 1. ; The linear distance between target atoms emitted from the target micro-element and deposited onto the three-dimensional mesh element, in cm; It is a constant with a value of 3.14.

[0021] Furthermore, in step 3, it is determined whether the connection between each 3D mesh element and each target micro-element in the current moving position is obscured by other parts of the complex curved surface to be plated. This is achieved using the following method:

[0022] Construct a spatial line segment equation using the spatial coordinates of the current target material micro-element and the spatial coordinates of the current three-dimensional mesh element, and then combine this spatial line segment equation with the three-dimensional spatial surface function equation of the complex surface to be coated to form a system of equations:

[0023]

[0024] In the formula, For parameter variables; These are the coordinate variables of a spatial point in the three-dimensional rectangular coordinate system OXYZ along the X-axis, Y-axis, and Z-axis, respectively. These are the spatial coordinates of a three-dimensional mesh cell; The spatial coordinates of the target material micro-element;

[0025] Solving a system of equations with respect to parameter variables The number of intersection solutions within the constraint range. When the number of intersection solutions is equal to 1, it is determined that the transmission path between the current target micro-element and the current three-dimensional mesh element is unobstructed; when the number of intersection solutions is greater than 1, it is determined that the transmission path between the current target micro-element and the current three-dimensional mesh element is obstructed by other parts of the complex surface to be plated.

[0026] Furthermore, in step 3, if the coating is obscured, the corresponding micro-element theoretical coating thickness is corrected, specifically as follows:

[0027] When it is determined that there is no obstruction in the transmission path between the current target micro-element and the current three-dimensional mesh element, the corresponding theoretical coating thickness of the micro-element calculated in step 2 is retained as the micro-element deposition thickness.

[0028] When it is determined that the transmission path between the current target micro-element and the current three-dimensional mesh unit is blocked, the corresponding theoretical coating thickness of the micro-element is corrected to 0, and the corrected thickness of 0 is taken as the micro-element deposition thickness.

[0029] Furthermore, in step 4, the total coating thickness distribution of the complex curved surface to be plated is calculated according to the following formula:

[0030]

[0031] in, For the first The corrected coating thickness for each 3D mesh element. ; This represents the total number of three-dimensional mesh elements. This represents the total number of positions the sputtering target has moved. For the first The 3D mesh element in the th... Corrected coating thickness at each moving position; For the first The time percentage corresponding to each movement location, and satisfying the following conditions: .

[0032] Furthermore, in step 5, the coating thickness uniformity evaluation index is characterized by the relative deviation of the mean coating thickness:

[0033]

[0034]

[0035] In the formula, This represents the relative deviation of the average coating thickness. This represents the total number of three-dimensional mesh elements. For the first The corrected coating thickness for each 3D mesh element. ; This represents the average corrected coating thickness of all three-dimensional mesh elements on the complex curved surface to be coated.

[0036] Furthermore, in step 5, the preset requirement is: the relative deviation of the average coating thickness. Less than or equal to the coating thickness uniformity threshold Coating thickness uniformity threshold The coating thickness uniformity requirement is preset according to the complex curved surface to be coated.

[0037] Furthermore, in step 5, the proportion of sputtering time corresponding to each moving position is adjusted, specifically including:

[0038] With the coordinates of each moving position fixed, the corrected coating thickness of each three-dimensional mesh element at each moving position per unit sputtering time is calculated, and the calculation results are used as the unit thickness contribution of each moving position.

[0039] Multiple candidate combinations of sputtering time percentages are defined, and each sputtering time percentage in each candidate combination satisfies the condition that it is non-negative and its sum is 1.

[0040] Calculate the total coating thickness distribution and coating thickness uniformity evaluation index for each group of candidate combinations of sputtering time percentages;

[0041] Based on the current total coating thickness distribution, the thin and thick regions are determined. The improvement of the coating thickness uniformity evaluation index is used as the basis for selecting the optimal sputtering time ratio candidate combination. The sputtering time ratio is adjusted by adjusting the sputtering time ratio of each moving position according to the ratio of its corresponding unit thickness contribution between the thin and thick regions.

[0042] Furthermore, in step 5, adjusting the distribution of the moving positions specifically includes:

[0043] The proportion of sputtering time corresponding to each moving position remains unchanged, and the thinner and thicker areas are determined based on the current total coating thickness distribution.

[0044] Multiple candidate combinations of moving positions are generated according to a preset step size or a preset arrangement; Steps 2 to 5 are executed on each candidate combination of moving positions to obtain the total coating thickness distribution and coating thickness uniformity evaluation index corresponding to each candidate combination of moving positions.

[0045] If a candidate combination of moving positions simultaneously meets the following conditions, then this candidate combination is used as the updated position parameter combination, and the updated position parameter combination and the corresponding sputtering time ratio are used as the updated optimal sputtering parameter combination:

[0046] Condition 1: The contribution of the candidate combination of moving positions to the thickness of the thinner region is higher than that of the current candidate combination of moving positions, and the increase exceeds a preset threshold.

[0047] Condition 2: The contribution of the candidate combination of moving positions to the thickness of the thicker region is reduced compared to the current candidate combination of moving positions, or the increase does not exceed the preset threshold.

[0048] Condition 3: The coating thickness uniformity evaluation index of this candidate combination of moving positions is better than that of the current candidate combination of moving positions;

[0049] When there are multiple candidate combinations of moving positions that meet the above conditions, the combination with the best coating thickness uniformity evaluation index is selected as the updated position parameter combination.

[0050] Furthermore, the rules for determining the thinner and thicker regions based on the current total coating thickness distribution are as follows:

[0051] The average coating thickness is calculated based on the current total coating thickness distribution, and the average coating thickness is used as the benchmark value.

[0052] Set a thickness deviation ratio threshold;

[0053] Areas where the coating thickness is lower than the reference value and the thickness deviation is greater than the thickness deviation ratio threshold are designated as thinner areas; areas where the coating thickness is higher than the reference value and the thickness deviation is greater than the thickness deviation ratio threshold are designated as thicker areas.

[0054] The advantages of this invention are:

[0055] 1. The method for predicting and controlling the uniformity of coating thickness distribution in magnetron sputtering of complex curved surfaces provided by this invention discretizes the sputtering target and the complex curved surface to be coated into three-dimensional mesh units. It introduces a path-by-path determination and correction method for spatial occlusion relationships of the complex curved surface, and performs point-by-point judgment on whether the line connecting each three-dimensional mesh unit to the current position of the sputtering target is occluded by other parts of the complex curved surface. This effectively identifies whether there is intermediate occlusion between the target micro-element and the three-dimensional mesh unit, and corrects the thickness contribution of the occluded path to zero, avoiding the problem of the theoretical film thickness contribution of the occluded area being included. For complex curved surfaces with features such as grooves, steps, and local protrusions, this invention can significantly improve the accuracy of coating thickness distribution prediction, providing a reliable data foundation for subsequent uniformity control.

[0056] 2. This invention enables rapid simulation and comparison of coating thickness distribution on complex curved surfaces under different parameter combinations by setting multiple combinations of sputtering target movement positions and weighting them together with the sputtering time ratio corresponding to each combination. Application examples of this invention demonstrate that adjusting the spatial distribution of the sputtering target movement positions can effectively improve the uniformity of coating thickness distribution on complex curved surfaces, verifying the feasibility of the control strategy of this invention and providing a reference for determining multiple movement position parameter combinations for sputtering targets.

[0057] 3. The two control methods provided in this invention are: first, fixing the moving position and adjusting the sputtering time ratio; and second, fixing the sputtering time ratio and adjusting the moving position. These two control methods can be used individually or in combination, flexibly adapting to different coating equipment and process conditions. This invention optimizes the moving position and sputtering time ratio of the sputtering target through computer simulation, and the output results can be directly used as process parameters for magnetron sputtering equipment, reducing the number of trials and time costs required by traditional trial-and-error methods. Attached Figure Description

[0058] Figure 1 This is a flowchart illustrating the method for predicting and controlling the uniformity of thickness distribution in complex curved surface magnetron sputtering coatings according to the present invention.

[0059] Figure 2 This is a schematic diagram of the complex curved surface to be plated and its three-dimensional mesh unit division in an embodiment of the present invention;

[0060] Figure 3 This is a discrete schematic diagram of a circular planar sputtering target in an embodiment of the present invention;

[0061] Figure 4 This is a schematic diagram of magnetron sputtering of a circular planar sputtering target in an embodiment of the present invention;

[0062] Figure 5 This is a schematic diagram of the sputtering model of the sputtering target in an embodiment of the present invention;

[0063] Figure 6 This is a schematic diagram illustrating the determination of occlusion of the shadow portion of the complex curved surface to be plated in an embodiment of the present invention;

[0064] Figure 7 This is a schematic diagram illustrating eight possible combinations of moving positions of the sputtering target in an embodiment of the present invention; wherein, Figure 7 (a) to (h) correspond to different combinations of movement positions for numbers 1 to 8, respectively;

[0065] Figure 8 This is a diagram showing the coating thickness distribution on a complex curved surface of a sputtering target under eight different moving position combinations, as described in this embodiment of the invention. Figure 8In the middle (a) to (h), the results of coating thickness distribution on complex curved surfaces with different combinations of moving positions (numbers 1-8) are respectively.

[0066] Figure 9 This is a schematic diagram showing the relative deviation of the average coating thickness for eight different moving position combinations of the sputtering target in an embodiment of the present invention.

[0067] Figure labeling: 1-Complex curved surface to be coated, 2-Sputtering target, 3-Sputtering ring, 4-Target micro-element, 5-Three-dimensional mesh unit. Detailed Implementation

[0068] The embodiments of the present invention are described in detail below. These embodiments are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0069] Reference Figure 1 This embodiment provides a method for predicting and controlling the uniformity of coating thickness distribution in magnetron sputtering of complex curved surfaces. Before sputtering, the method uses computer simulation to plan and optimize the movement path of the sputtering target, outputting the optimal combination of process parameters that makes the coating thickness uniform across different parts of the complex curved surface. This achieves accurate prediction and uniformity control of coating thickness distribution during magnetron sputtering of complex curved surface workpieces with features such as grooves, steps, and local undulations, without relying on real-time measurement data during the sputtering process. Specifically, it includes the following steps:

[0070] Step 1: Establish 3D models of the complex curved surface 1 to be deposited and the sputtering target 2, and discretize them respectively. This step is the basis for subsequent deposition thickness calculation and occlusion determination, and includes the following processes:

[0071] Reference Figure 2 The complex surface model to be plated is established in a three-dimensional spatial coordinate system OXYZ. Those skilled in the art can, based on the actual surface shape, use parametric modeling or reverse engineering to establish the three-dimensional spatial surface function equations of the complex surface to be plated, denoted as... ,in These represent the coordinate variables of a spatial point along the X, Y, and Z axes in a three-dimensional Cartesian coordinate system OXYZ. In this embodiment, a circular planar sputtering target is used. The plane in question serves as a reference plane for the complex curved surface to be plated, and the target surface of the sputtering target is set on it. The plane in which they lie, that is, the perpendicular distance between them, is .in, This refers to the outer diameter of the sputtering ring of the sputtering target. The vertical distance between the target surface of the sputtering target and the reference plane of the complex curved surface to be coated can be adjusted according to the coating process requirements, and its adjustment range is... In this embodiment, it is preferably configured as described above. The complex curved surface to be plated is discretized into multiple three-dimensional mesh elements 5 of the same size along the X-axis and Y-axis, and all three-dimensional mesh elements 5 are numbered sequentially according to a preset traversal order. , Indicates the number of the three-dimensional mesh element. This represents the total number of 3D mesh elements, with each number uniquely corresponding to a 3D mesh element. In this embodiment, the center point of each 3D mesh element is used as its spatial location representative point, and the spatial coordinates of the center point of the 3D mesh element are used as the spatial coordinates of the 3D mesh element, denoted as [reference needed]. .

[0072] like Figure 3 As shown, the sputtering target 2 at its current position is discretized along its circumference as follows: Four target micro-elements. Each target micro-element has an equal area. In a preferred embodiment, the target micro-element is... The target material micro-elements are uniformly distributed at a radius of [missing information]. On the annular region, an etched annular region, i.e., sputtering ring 3, is used to simulate the actual magnetron sputtering target. The radius of this annular region... ,in and These represent the inner and outer diameters of the sputtering ring, respectively, of the sputtering target. The center point of each target micro-element is taken as its spatial position representative point, and the spatial coordinates of the target micro-element's center point are taken as the spatial coordinates of the target micro-element, denoted as [reference needed]. .

[0073] Step 2: Calculate the theoretical coating thickness of each 3D mesh element when the sputtering target is in its current position and spatial obstruction is not considered. This includes the following steps:

[0074] Step 2.1, Figure 4 This is a schematic diagram of magnetron sputtering of a circular sputtering target in this embodiment. In the figure: The origin of the coordinate system is located at the center of the circular sputtering target. Let be the normal vector of the target material element; The normal vector of a 3D mesh element; The emission angle of the target atoms; The deposition angle of the target atoms; the gray area represents the sputtering ring 3 on the surface of the sputtering target, and the black ellipse represents any target micro-element located on the sputtering ring; the ellipse with the cross-section line represents the three-dimensional mesh unit 5.

[0075] Define the center point of the target material micro-element as A, and the center point of the three-dimensional mesh element as B. Establish the spatial vector between the center point of the target material micro-element and the center point of the three-dimensional mesh element. And calculate its modulus. The modulus is the straight-line distance from the target atom exiting the target micro-element and depositing onto the three-dimensional mesh element. .

[0076] Step 2.2: Take the normal vector at the center point of the target element as the normal vector of the target element. The normal vector at the center point of the 3D mesh element is used as the normal vector of the 3D mesh element. .

[0077] Based on the normal vector of the target material micro-element and the normal vector of the 3D mesh element Based on the geometric relationship, the emission angle of the target atoms is calculated. and sedimentation angle cosine value:

[0078] (1)

[0079] (2)

[0080] In the formula, The spatial coordinates of the target material micro-element; These are the spatial coordinates of a three-dimensional mesh cell; The equation of the three-dimensional spatial surface function for the complex surface to be plated; , and The complex curved surface to be plated is located at the coordinate points. The partial derivatives along the X, Y, and Z axes at the given point; Let be the normal vector of the target material element. is the normal vector of a 3D mesh element.

[0081] Step 2.3, construct the sputtering model of the sputtering target, such as Figure 5 As shown. Based on the spatial projection relationship of the sputtering target model and the sputtering characteristics of the target, a formula is established to calculate the theoretical coating thickness of the micro-element formed by the deposition of target atoms sputtered from any micro-element on a circular planar sputtering target onto the three-dimensional mesh unit of the complex curved surface to be coated per unit time:

[0082] (3)

[0083] In the formula, The theoretical coating thickness is denoted by , representing the thickness of the theoretical coating formed per unit time by the deposition of target atoms sputtered from any micro-element of a circular planar sputtering target onto a three-dimensional mesh element of the complex curved surface to be coated. Its unit is . ; The density of target atoms, in units of ; Sputtering rate, in units of ; The emission angle of the target atoms is expressed in degrees (°). The deposition angle of the target atoms, in degrees; The area of ​​the target material element is expressed in units of 1. ; The linear distance between target atoms emitted from the target micro-element and deposited onto the three-dimensional mesh element, in cm; It is a constant with a value of 3.14.

[0084] According to the above formula (3), the theoretical coating thickness of each three-dimensional mesh unit can be calculated without considering the influence of spatial occlusion.

[0085] Step 3: Considering the spatial occlusion relationship formed by complex curved surfaces, the thickness of the micro-element theoretical coating of the three-dimensional mesh unit obtained in Step 2 is corrected.

[0086] like Figure 6 As shown, local protrusions on the complex curved surface to be coated may obstruct the transmission path from the target micro-element to the three-dimensional mesh unit, thus forming a shadow area. Therefore, this embodiment performs obstruction determination on the transmission path between each target micro-element and each three-dimensional mesh unit, and corrects the theoretical coating thickness of the corresponding micro-element based on the determination results. The specific steps are as follows:

[0087] Step 3.1: Construct the spatial line segment equation between the current target material micro-element and the current three-dimensional mesh unit, and then combine this spatial line segment equation with the three-dimensional spatial surface function equation of the complex surface to be coated. Form a system of equations by combining the following equations:

[0088] (4)

[0089] In the formula, For parameter variables.

[0090] Step 3.2, based on the system of equations (4) formed in step 3.1, in the parameter variables The number of solutions within the constraint range is used to determine whether the transmission path between the current target micro-element and the current 3D mesh element is blocked, and the theoretical coating thickness of the micro-element is calculated. Make corrections. (Refer to...) Figure 6 The diagram shown illustrates the determination of complex curved surface shadow occlusion. The specific determination method and correction rules are as follows:

[0091] Since the three-dimensional mesh element itself is located on the complex curved surface to be plated, the equation system (4) has different parameter variables. Within the constraints, there must be at least one intersection solution. Based on this, it is necessary to further determine the solution of equation system (4). Are there any other intersection points within the interval, i.e.:

[0092] When the system of equations is When the number of intersection points within the interval is equal to 1, it is determined that the transmission path between the current target material element and the current 3D mesh element is unobstructed. In this case, the theoretical coating thickness of the micro-element calculated in step 2 is retained. And as the thickness of the micro-element deposition;

[0093] When the system of equations is If the number of intersection points within the interval is greater than 1, it is determined that the transmission path between the current target micro-element and the current 3D mesh element is blocked by other parts of the complex curved surface to be coated, and sputtered atoms cannot effectively reach the current 3D mesh element. In this case, the theoretical coating thickness of the corresponding micro-element is adjusted. The thickness is corrected to 0, and the corrected thickness of 0 is taken as the micro-element deposition thickness.

[0094] Step 3.3: Accumulate and calculate the deposition thickness of all target micro-elements corresponding to the same three-dimensional mesh unit to obtain the corrected coating thickness of the three-dimensional mesh unit at the current moving position of the target.

[0095] Step 4: Calculate the total coating thickness distribution of the complex curved surface to be coated.

[0096] Steps 2 and 3 are repeated at all moving positions along the preset moving path of the sputtering target to obtain the corrected coating thickness of all 3D mesh elements at each moving position. Based on the sputtering time proportion corresponding to each moving position, the corrected coating thickness of all 3D mesh elements at each moving position is weighted and superimposed to obtain the total coating thickness distribution of the complex curved surface to be coated. Specifically, the following steps are included:

[0097] Step 4.1: Set multiple moving positions on the preset moving path of the sputtering target. In this embodiment, the magnetron sputtering process uses a method where the substrate to be coated on a complex curved surface is fixed and the sputtering target is moved. Based on the requirement to control the uniformity of the surface coating thickness distribution on the complex curved surface, the total number of moving positions of the sputtering target is set to [number missing]. The information on the moving positions includes the number of moving positions, the spatial coordinates of each moving position, and the corresponding splashing time ratio; the sum of the splashing time ratios of all moving positions is 1.

[0098] Step 4.2: For any moving position, treat it as a single sputtering target position and repeat the calculation process of Steps 2 to 3 to calculate the corrected coating thickness of all three-dimensional mesh elements corresponding to the moving position per unit sputtering time.

[0099] Step 4.3: After obtaining the corrected coating thickness of all 3D mesh elements corresponding to each moving position, the corrected coating thickness of all 3D mesh elements at each moving position is weighted and superimposed based on the sputtering time ratio corresponding to each moving position to obtain the total coating thickness distribution of the complex curved surface to be coated. The weighted superposition calculation formula is as follows:

[0100] (5)

[0101] in, For the first The corrected coating thickness for each 3D mesh element. ; This represents the total number of three-dimensional mesh elements. For the first The 3D mesh element in the th... Corrected coating thickness at each moving position; For the first The time percentage corresponding to each movement location, and satisfying the following conditions: ; This represents the total number of positions the sputtering target has moved.

[0102] Step 5: Calculation of coating thickness uniformity evaluation index and parameter iterative optimization and control.

[0103] Based on the total coating thickness distribution results obtained in step 4, a coating thickness uniformity evaluation index is calculated to characterize the uniformity of the coating thickness distribution on complex curved surfaces under the current parameter combination. Specifically, this includes:

[0104] Step 5.1: Based on the coating thickness distribution results of the complex curved surface obtained in Step 4, calculate the average coating thickness of all three-dimensional mesh elements. :

[0105] (6)

[0106] In the formula, This represents the total number of three-dimensional mesh cells.

[0107] Step 5.2: Based on the results obtained in Step 5.1, calculate the coating thickness uniformity evaluation index.

[0108] In this embodiment, the coating thickness uniformity evaluation index is the relative deviation of the mean coating thickness. The characterization, its calculation formula is:

[0109] (7)

[0110] In the formula, This represents the relative deviation of the average coating thickness. The smaller the value, the more uniform the coating thickness distribution; This represents the total number of three-dimensional mesh cells.

[0111] Step 5.3: Determine whether the obtained coating thickness uniformity evaluation index meets the preset requirements. When the coating thickness uniformity evaluation index meets the preset requirements, the current moving positions and their corresponding sputtering time ratios are used as the optimal sputtering parameter combination. When the coating thickness uniformity evaluation index does not meet the preset requirements, adjust the sputtering target moving parameters and repeat steps 2 to 5 until the coating thickness uniformity evaluation meets the preset requirements, thus achieving optimized control of the sputtering target moving parameters. In this embodiment, the adjustment methods include adjusting the sputtering time ratio and / or adjusting the moving position.

[0112] The preset requirement mentioned here is: the relative deviation of the average coating thickness. Less than or equal to the coating thickness uniformity threshold Coating thickness uniformity threshold The value is preset according to the coating thickness uniformity requirements of the complex curved surface to be coated. Those skilled in the art can determine the coating thickness uniformity threshold within the range of 0.05 to 0.1 based on actual magnetron sputtering requirements. Size.

[0113] In this embodiment, two preferred adjustment methods are included, specifically:

[0114] Adjustment Method 1: Fix the moving position and adjust the splash time percentage.

[0115] Keeping the spatial coordinates of each moving position of the sputtering target unchanged, only adjusting the sputtering time percentage corresponding to each moving position. Specifically, first calculate the corrected coating thickness of each 3D mesh element at each moving position per unit sputtering time, and use this as the unit thickness contribution for each moving position; then set multiple candidate combinations of sputtering time percentages, where each sputtering time percentage in each candidate combination satisfies the condition of being non-negative and summing to 1; resubmit these values ​​to steps 2 through 5 to calculate the complex surface coating thickness distribution and coating thickness uniformity evaluation index corresponding to each candidate combination of sputtering time percentages; determine the thinner and thicker regions based on the current total coating thickness distribution, and use the improvement in the current coating thickness uniformity evaluation index as the selection criterion for the optimal sputtering time percentage candidate combination, with the sputtering time percentage adjusted as follows:

[0116] The sputtering time percentages for each current moving position are adjusted according to the ratio of their unit thickness contribution to the thinner and thicker regions. Specifically, the sputtering time percentage for moving positions that significantly contribute to the unit thickness in the thinner region is increased, while the sputtering time percentage for moving positions that significantly contribute to the unit thickness in the thicker region is decreased. The combination of sputtering time percentages that minimizes the coating thickness uniformity evaluation index is searched and selected as the optimal candidate combination. This optimal candidate combination of sputtering time percentages and the corresponding sputtering target position are then used as the updated optimal combination of sputtering parameters.

[0117] The optimal sputtering parameter combination includes the total number of sputtering target movement positions, spatial position coordinates, and the corresponding proportion of sputtering time.

[0118] Adjustment Method 2: Fix the splashing time percentage and adjust the moving position.

[0119] While maintaining the sputtering time percentage corresponding to each moving position of the sputtering target, adjust the spatial coordinates of the moving positions. Specifically, based on the current total coating thickness distribution, determine the thinner and thicker regions, and generate multiple candidate combinations of moving positions according to a preset step size or preset arrangement. For each candidate combination, resubmit steps 2 to 5 to obtain the updated total coating thickness distribution and coating thickness uniformity evaluation index. If a candidate combination of moving positions simultaneously meets the following conditions, then that candidate combination is used as the updated position parameter combination, and the updated position parameter combination and its corresponding sputtering time percentage are used as the updated optimal sputtering parameter combination:

[0120] Condition 1: The contribution of the candidate combination of moving positions to the thickness of the thinner region is higher than that of the current candidate combination of moving positions, and the increase exceeds a preset threshold (set to 1% in this embodiment).

[0121] Condition 2: The contribution of the candidate combination of moving positions to the thickness of the thicker region is reduced compared to the current candidate combination of moving positions, or the increase does not exceed the preset threshold.

[0122] Condition 3: The coating thickness uniformity evaluation index of this candidate combination of moving positions is better than that of the current candidate combination of moving positions.

[0123] When there are multiple candidate combinations of moving positions that meet the above conditions, the combination with the best coating thickness uniformity evaluation index is selected as the updated position parameter combination.

[0124] In this embodiment, the rule for determining thin and thick regions based on the current total coating thickness distribution is as follows: The average coating thickness is calculated based on the current total coating thickness distribution, and this average thickness is used as a baseline value; a thickness deviation ratio threshold is set; regions where the coating thickness is lower than the baseline value and the thickness deviation is greater than the thickness deviation ratio threshold are designated as thin regions; regions where the coating thickness is higher than the baseline value and the thickness deviation is greater than the thickness deviation ratio threshold are designated as thick regions. In this embodiment, the thickness deviation ratio threshold is set to 5%, meaning that regions where the coating thickness is less than or equal to 95% of the baseline value are defined as thin regions, and regions where the coating thickness is greater than or equal to 105% of the baseline value are defined as thick regions.

[0125] To verify the effectiveness of the method of the present invention, a specific application example is given below.

[0126] In this application example, the projection of the complex surface to be plated onto the XOY plane is defined as a square region, and its three-dimensional spatial surface function equation is: The complex curved surface to be plated exhibits localized convexities and depressions at the four corners and center, displaying typical irregular undulation characteristics. The complex curved surface to be plated is discretized along the X-axis and Y-axis directions as follows: The circular planar sputtering target is discretized into eight target micro-elements using a three-dimensional mesh element. For ease of calculation, this application example normalizes the relevant parameters and uses the normalized dimensionless parameters as the calculation parameters. The specific method is as follows:

[0127] The outer diameter of the sputtering ring of the sputtering target material As a reference parameter, and let .

[0128] The inner diameter of the sputtering ring of the sputtering target. The target-substrate distance and the length of the complex curved surface to be coated are all based on the outer diameter of the sputtering ring of the sputtering target. The sputtering ring inner diameter of the sputtering target is obtained by normalizing the sputtering process based on the reference. The target-substrate distance is 1.5, and the eight discrete target micro-elements are uniformly distributed on a ring with a radius of 0.75; the coating area of ​​the complex curved surface to be coated satisfies... and The side length of the projection of the complex surface to be plated onto the XOY plane is 4; the offset length of the complex surface to be plated along the X-axis and Y-axis is 0.05.

[0129] Set the total number of moving positions of the sputtering target. There are four possible positions, with the initial sputtering time percentage for each movement position set to 0.25. To demonstrate the effect of this invention on controlling the uniformity of coating thickness on complex curved surfaces, this application example performs simulation calculations for eight typical combinations of movement positions. Figure 7The projections of various spatial distribution forms, including inner quadrilaterals, outer quadrilaterals, intersecting shapes, edge-midpoint shapes, vertical lines, and asymmetric shapes, onto the XOY plane are shown. These eight combinations of sputtering target movement positions cover different spatial distribution forms such as internal arrays, corner arrangements, center-neighborhood arrangements, edge arrangements, linear arrangements, and asymmetric arrangements. Table 1 lists... Figure 7 The eight types of sputtering target combinations are shown in the table below. The table includes the combination number of the moving position, the coordinates of the center of the sputtering target, and the proportion of sputtering time. The moving position combinations numbered 2 and 4 are arranged in the same way as the moving position combinations numbered 1 and 3, except that the spacing between each moving position is increased.

[0130] Table 1. Coordinates of the center of the sputtering target corresponding to different combinations of moving positions.

[0131]

[0132] This application example uses Matlab software to calculate the thickness distribution of the coating on the complex curved surface to be coated and the relative deviation of the mean coating thickness under the above-mentioned combination of moving positions of the sputtering target. Figure 8 The figure shows the coating thickness distribution of the complex curved surface to be coated under the moving position combination of eight sputtering targets numbered 1 to 8 in Table 1. The coating thickness in different areas is represented by the color depth. The white circle in the figure represents the peak position of the coating thickness. The X and Y coordinate values ​​corresponding to the peak position of the coating thickness and the coating thickness are shown in Table 2.

[0133] Table 2. Peak coating thickness and corresponding positions for different sputtering target movement combinations.

[0134]

[0135] In this application example, during the numerical calculation of step 2, the density of the target atoms is... Sputtering rate Target material micro-element area Relevant parameters were dimensionless to compare the relative spatial distribution of coating thickness under different combinations of movement positions. This processing only changes the overall scale of the coating thickness values ​​and does not affect the relative spatial distribution of coating thickness or the calculation results of coating thickness uniformity evaluation indicators. Therefore, the peak coating thickness values ​​shown in Table 2 are dimensionless coating thickness values ​​and do not represent absolute coating thickness peak values ​​with actual thickness and dimensions. Figure 8 Comparing examples (a) and (b), it can be seen that when the arrangement of the moving positions of the sputtering target remains unchanged, and only the spacing between each moving position is increased, the peak coating thickness decreases from 1.3003 to 0.74238, a reduction of 43%.

[0136] because Figure 8 Only a rough observation of the uniformity of coating thickness distribution on complex curved surfaces can be made. To analyze the changes in coating thickness uniformity on complex curved surfaces more specifically, Figure 9 The relative deviation of the mean coating thickness on complex curved surfaces is given under eight combinations of sputtering target movement positions. The changing pattern. Observe. Figure 9 It can be seen that the relative deviation of the average coating thickness of the complex surface of the moving position combinations numbered 3, 5, 6, 7, and 8 is significantly increased compared with the initial sputtering target position combination (number 1). The relative deviation of the average coating thickness of the complex surface of the moving position combination numbered 2 increases from 0.27919 to 0.29374 compared with the moving position combination numbered 1, an increase of 5%. The relative deviation of the average coating thickness of the complex surface of the moving position combination numbered 4 decreases from 0.39735 to 0.23529 compared with the moving position combination numbered 3, a decrease of 41%, indicating improved coating uniformity. Analysis shows that the moving position combination numbered 4 has the best coating uniformity on the complex surface. The center coordinates of the sputtering target corresponding to the moving position combination numbered 4 are taken as the optimal center coordinates of the sputtering target moving position, and the corresponding position parameters of this moving position combination are taken as the optimal combination of position parameters.

[0137] It should be noted that, Figure 9 This only demonstrates the changes in the relative deviation of the mean coating thickness for eight typical sputtering target movement position combinations during the sputtering target movement position optimization process. The purpose is to illustrate the influence of sputtering target movement position adjustments on coating thickness uniformity, not the results of a global optimization iteration. The relative deviation of the mean coating thickness corresponding to movement position combination number 4 is 0.23529. Although it exhibits the best uniformity among the eight positions shown, its value is still significantly greater than the preset coating thickness uniformity threshold for this example. (Settings in this application example) Since the value is 0.1, this location can only be considered a locally optimal combination of locations in the current search phase, and the uniformity does not yet meet the final preset requirements. In the actual optimization process, it is necessary to use the relative deviation of the average coating thickness described in step 5. Less than or equal to the coating thickness uniformity threshold As the termination condition for the iteration, the optimization continues near the combination of moving positions numbered 4 until the relative deviation of the average coating thickness is satisfied. Only by determining the optimal combination of target position parameters can this combination be considered the best sputtering parameter combination. Therefore, currently... Figure 9 The results shown do not constitute a limitation on the final optimization effect of this embodiment.

[0138] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the scope of the technology disclosed in the present invention, and such modifications or substitutions should all be covered within the scope of protection of the present invention.

Claims

1. A method for predicting and controlling the uniformity of thickness distribution in magnetron sputtered coatings on complex curved surfaces, characterized in that, Includes the following steps: Step 1: Discretize the complex curved surface to be coated into multiple three-dimensional mesh units, discretize the surface of the sputtering target into multiple target micro-elements, and discretize the preset moving path of the sputtering target into several moving positions. Step 2: Calculate the theoretical coating thickness of each micro-element of the sputtering target sputtered to each of the three-dimensional mesh units when the sputtering target is in its current moving position and without considering the influence of spatial obstruction; Step 3: Based on the spatial geometric relationship of the complex surface to be coated, determine whether the connection between each of the three-dimensional mesh units and each of the target micro-elements in the current moving position is blocked by other parts of the complex surface to be coated. If blocked, the theoretical coating thickness of the corresponding micro-element is corrected, and the corrected thickness is used as the micro-element deposition thickness. If it is not obscured, the theoretical coating thickness of the micro-element obtained in step 2 shall be used as the micro-element deposition thickness; The deposition thickness of each three-dimensional mesh cell and the corresponding micro-element of all target materials are summed to obtain the corrected coating thickness of each three-dimensional mesh cell at the current moving position. Step 4: Repeat steps 2-3 for all moving positions on the preset moving path to obtain the corrected coating thickness of all three-dimensional mesh elements at each moving position; Based on the sputtering time ratio corresponding to each moving position, the corrected coating thickness of all three-dimensional mesh elements at each moving position is weighted and superimposed to obtain the total coating thickness distribution of the complex curved surface to be coated. Step 5: Calculate the coating thickness uniformity evaluation index based on the total coating thickness distribution obtained in Step 4, and determine whether the coating thickness uniformity evaluation index meets the preset requirements: if the preset requirements are met, then the current moving positions and their corresponding sputtering time ratios are used as the optimal sputtering parameter combination. If the preset requirements are not met, the distribution of the moving positions and / or the sputtering time ratio corresponding to each moving position are adjusted, and steps 2-4 are repeated until the coating thickness uniformity evaluation index meets the preset requirements. The moving positions and their corresponding sputtering time ratios corresponding to the last iteration are taken as the optimal sputtering parameter combination.

2. The method for predicting and controlling the uniformity of thickness distribution of magnetron sputtered coatings on complex curved surfaces according to claim 1, characterized in that, In step 2, the theoretical thickness of the micro-element coating is calculated using the following formula: In the formula, The theoretical coating thickness is denoted by , representing the thickness of the theoretical coating formed per unit time by the deposition of target atoms sputtered from any micro-element of a circular planar sputtering target onto a three-dimensional mesh element of the complex curved surface to be coated. Its unit is . ; The density of target atoms, in units of ; Sputtering rate, in units of ; The emission angle of the target atoms is expressed in degrees (°). The deposition angle of the target atoms, in degrees; The area of ​​the target material element is expressed in units of 1. ; The linear distance between target atoms emitted from the target micro-element and deposited onto the three-dimensional mesh element, in cm; It is a constant with a value of 3.

14.

3. The method for predicting and controlling the uniformity of thickness distribution of magnetron sputtered coatings on complex curved surfaces according to claim 2, characterized in that, In step 3, it is determined whether the connection between each of the three-dimensional mesh elements and each of the target material micro-elements at the current moving position is obscured by other parts of the complex curved surface to be plated. This is achieved using the following method: Construct a spatial line segment equation using the spatial coordinates of the current target material micro-element and the spatial coordinates of the current three-dimensional mesh element, and then combine this spatial line segment equation with the three-dimensional spatial surface function equation of the complex surface to be plated to form a system of equations: In the formula, For parameter variables; These are the coordinate variables of a spatial point in the three-dimensional rectangular coordinate system OXYZ along the X-axis, Y-axis, and Z-axis, respectively. These are the spatial coordinates of a three-dimensional mesh cell; The spatial coordinates of the target material micro-element; Solve the system of equations with respect to the parameter variables. The number of intersection solutions within the constraint range. When the number of intersection solutions is equal to 1, it is determined that the transmission path between the current target micro-element and the current three-dimensional mesh element is unobstructed. When the number of intersection solutions is greater than 1, it is determined that the transmission path between the current target micro-element and the current three-dimensional mesh unit is blocked by other parts of the complex surface to be plated.

4. The method for predicting and controlling the uniformity of thickness distribution of magnetron sputtered coatings on complex curved surfaces according to claim 3, characterized in that, In step 3, if the coating is obscured, the corresponding theoretical coating thickness is corrected, specifically as follows: When it is determined that there is no obstruction in the transmission path between the current target micro-element and the current three-dimensional mesh unit, the corresponding theoretical coating thickness of the micro-element calculated in step 2 is retained as the micro-element deposition thickness. When it is determined that the transmission path between the current target micro-element and the current three-dimensional mesh unit is blocked, the corresponding theoretical coating thickness of the micro-element is corrected to 0, and the corrected thickness of 0 is used as the micro-element deposition thickness.

5. The method for predicting and controlling the uniformity of thickness distribution of magnetron sputtered coatings on complex curved surfaces according to claim 1, characterized in that, In step 4, the total coating thickness distribution of the complex curved surface to be plated is calculated according to the following formula: in, For the first The corrected coating thickness for each 3D mesh element. ; This represents the total number of three-dimensional mesh elements. This represents the total number of positions the sputtering target has moved. For the first The 3D mesh element in the th... Corrected coating thickness at each moving position; For the first The time percentage corresponding to each movement location, and satisfying the following conditions: .

6. The method for predicting and controlling the uniformity of thickness distribution of magnetron sputtered coatings on complex curved surfaces according to claim 1, characterized in that, In step 5, the coating thickness uniformity evaluation index is characterized by the relative deviation of the mean coating thickness: In the formula, This represents the relative deviation of the average coating thickness. This represents the total number of three-dimensional mesh elements. For the first The corrected coating thickness for each 3D mesh element. ; This represents the average corrected coating thickness of all three-dimensional mesh elements on the complex curved surface to be coated.

7. The method for predicting and controlling the uniformity of thickness distribution of magnetron sputtered coatings on complex curved surfaces according to claim 6, characterized in that, In step 5, the preset requirement is: the relative deviation of the average coating thickness. Less than or equal to the coating thickness uniformity threshold Coating thickness uniformity threshold The coating thickness uniformity requirement is preset according to the complex curved surface to be coated.

8. The method for predicting and controlling the uniformity of thickness distribution of magnetron sputtered coatings on complex curved surfaces according to claim 1, characterized in that, In step 5, the sputtering time percentage corresponding to each of the aforementioned moving positions is adjusted, specifically including: With the coordinates of each of the moving positions fixed, the corrected coating thickness of each of the three-dimensional mesh elements at each of the moving positions per unit sputtering time is calculated, and the calculation result is used as the unit thickness contribution of each of the moving positions. Multiple sets of candidate combinations of sputtering time percentages are set, and each sputtering time percentage in each set of candidate combinations of sputtering time percentages satisfies the condition that it is non-negative and its sum is 1; Calculate the total coating thickness distribution and coating thickness uniformity evaluation index for each group of candidate combinations of sputtering time percentages; Based on the current total coating thickness distribution, the thin and thick regions are determined. The improvement of the coating thickness uniformity evaluation index is used as the selection criterion for the optimal sputtering time ratio candidate combination. The sputtering time ratio is adjusted by adjusting the sputtering time ratio of each current moving position according to the ratio of its corresponding unit thickness contribution between the thin and thick regions.

9. The method for predicting and controlling the uniformity of thickness distribution of magnetron sputtered coatings on complex curved surfaces according to claim 1, characterized in that, Step 5 involves adjusting the distribution of the moving positions, specifically including: The proportion of sputtering time corresponding to each of the moving positions is kept constant, and the thinner and thicker regions are determined according to the current total coating thickness distribution. Multiple candidate combinations of moving positions are generated according to a preset step size or a preset arrangement; Steps 2 to 5 are executed on each of the candidate combinations of moving positions to obtain the total coating thickness distribution and coating thickness uniformity evaluation index corresponding to each candidate combination of moving positions. If a candidate combination of the moving positions simultaneously satisfies the following conditions, then the candidate combination is taken as the updated position parameter combination, and the updated position parameter combination and the corresponding sputtering time ratio are taken as the updated optimal sputtering parameter combination: Condition 1: The contribution of the candidate combination of moving positions to the thickness of the thinner region is increased relative to the current candidate combination of moving positions, and the increase exceeds a preset threshold. Condition 2: The contribution of the candidate combination of moving positions to the thickness of the thicker region is reduced compared to the current candidate combination of moving positions, or the increase does not exceed a preset threshold. Condition 3: The coating thickness uniformity evaluation index of this candidate combination of moving positions is better than that of the current candidate combination of moving positions; When there are multiple candidate combinations of moving positions that meet the above conditions, the combination with the best coating thickness uniformity evaluation index is selected as the updated position parameter combination.

10. The method for predicting and controlling the uniformity of thickness distribution of magnetron sputtered coatings on complex curved surfaces according to claim 8 or 9, characterized in that, The rule for determining thinner and thicker regions based on the current total coating thickness distribution is as follows: The average coating thickness is calculated based on the current total coating thickness distribution, and the average coating thickness is used as the benchmark value. Set a thickness deviation ratio threshold; Areas where the coating thickness is lower than the reference value and the thickness deviation is greater than the thickness deviation ratio threshold are designated as thinner areas; areas where the coating thickness is higher than the reference value and the thickness deviation is greater than the thickness deviation ratio threshold are designated as thicker areas.

Images