Vacuum coating machine electron gun control method and system

Abstract

The present application belongs to the technical field of vacuum coating, and particularly relates to a vacuum coating machine electron gun control method and system, which comprises continuously collecting and fusing key real-time parameters reflecting the working state of the electron gun and the evaporation process during the coating process, real-time evaluating the current coating state based on the key real-time parameters, dynamically generating an electron beam control target instruction set for the next control cycle through a built-in decision mechanism in combination with preset coating process requirements, and sending the electron beam control target instruction set to the power controller, focusing coil controller and scanning coil controller of the electron gun to drive the electron gun to real-time adjust its power output, focusing state and scanning motion, and precisely and stably controlling the evaporation rate, effectively responding to material property changes through a strong closed loop of power and evaporation rate, and actively compensating for the non-uniformity of the crucible thermal field through a dynamically planned scanning path, and optimizing the beam spot energy distribution in combination with focusing adjustment to significantly improve the uniformity of the thermal field.

Description

Technical Field

[0001] This invention belongs to the field of vacuum coating technology, specifically a method and system for controlling the electron gun of a vacuum coating machine. Background Technology

[0002] Vacuum coating technology, especially that utilizing an electron gun evaporation source, is widely used in optics, semiconductors, and tool coatings because it can deposit high-melting-point, high-purity thin films. The electron gun, as the core component, directly determines the evaporation rate, film uniformity, and coating quality through its operating conditions (such as electron beam power, focusing, and scanning trajectory).

[0003] Currently, most common electron gun control methods are based on preset fixed parameter modes or simple feedback adjustments, such as fine-tuning the power only according to the crucible temperature or evaporation rate. However, in the actual coating process, the physical properties of the evaporating material, such as its morphology, thermal conductivity, and vapor pressure, are constantly changing during melting and consumption. Fixed power or scanning modes are difficult to maintain a stable evaporation rate and spot morphology. Uneven temperature distribution inside the crucible can lead to local overheating or insufficient evaporation, affecting the uniformity of film thickness. In the early stage of material melting or when local overheating occurs, splashes can easily be generated to contaminate the film layer. Existing control methods lack effective active prevention mechanisms for this.

[0004] Therefore, the present invention provides a method and system for controlling the electron gun of a vacuum coating machine. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, at least one technical problem raised in the background art is solved.

[0006] The technical solution adopted by this invention to solve its technical problem is: a vacuum coating machine electron gun control method and system, comprising the following steps:

[0007] A1. During the coating process, key real-time parameters reflecting the working status of the electron gun and the evaporation process are continuously collected and processed. The key real-time parameters include at least the real-time temperature distribution and real-time evaporation rate of the electron beam spot area.

[0008] A2. Based on key real-time parameters, the current coating status is evaluated in real time, and combined with the preset coating process requirements, the electron beam control target instruction set for the next control cycle is dynamically generated through the built-in decision-making mechanism. The instruction set includes: power target value, focus state target value, and scanning path target trajectory; wherein, the scanning path target trajectory is dynamically planned and generated based on the currently sensed crucible surface temperature distribution and material state, and is used to optimize thermal field uniformity, evaporation stability, and suppress splashing.

[0009] A3. The generated power target value, focus state target value, and scan path target trajectory command are synchronously sent to the power controller, focus coil controller, and scan coil controller of the electron gun to drive the electron gun to adjust its power output, focus state, and scan motion in real time.

[0010] Preferably, in step A2, the real-time temperature distribution of the electron beam spot area is obtained by a non-contact temperature measuring device, which is an infrared thermal imager or a pyrometer; in step A1, the real-time evaporation rate is obtained by an evaporation rate monitoring device, which is a quartz crystal oscillator or an optical monitoring device.

[0011] Preferably, in step A2, the real-time assessment of the current coating status includes: assessing the stability of the evaporation rate, assessing the uniformity of the electron beam spot temperature distribution and identifying local overheating or undercooling areas, and determining the material consumption stage.

[0012] Preferably, step A2 involves real-time evaluation of the current coating status, including:

[0013] Evaporation rate stability assessment: Calculate the standard deviation of the real-time evaporation rate within a set time window, and determine the unstable state when it exceeds the threshold;

[0014] Temperature distribution uniformity assessment: Scan the temperature distribution map of the electron beam spot area, identify overcooled or overheated areas that exceed the set temperature range, and calculate the area ratio of abnormal areas. When the area ratio of abnormal areas exceeds the area ratio threshold, it is judged as a non-uniform state.

[0015] Material consumption stage judgment: If the evaporation rate continues to decrease and the power regulation efficiency is lower than the set value, it is determined that the material depletion stage has been entered.

[0016] Preferably, in step A2, the built-in decision-making mechanism includes at least one of fuzzy logic control, PID control, or a machine learning-based predictive control model.

[0017] Preferably, the target trajectory of the scanning path is dynamically planned and generated based on the currently sensed crucible surface temperature distribution and material state, specifically as follows:

[0018] In areas identified as having excessively high temperatures, the plan is to reduce the scanning speed or power density dwell time, or to proceed quickly; in areas identified as having excessively low temperatures or insufficient evaporation, the plan is to increase the scanning speed or power density, or to increase the local scanning density or to perform reciprocating scanning.

[0019] Preferably, in the initial stage of material melting, the instruction set generated in step A2 is as follows: setting a lower initial power target value, setting a larger beam spot focusing state target value, and planning an initial scanning path target trajectory that avoids the easily overheated area in the center of the crucible, so as to smoothly melt the material and suppress splashing.

[0020] Preferably, in step A3, after receiving the instruction, the power controller, focusing coil controller and scanning coil controller make real-time adjustments. Their adjustment processes are interconnected and are coordinated and controlled by the target instruction set output by the same decision-making mechanism.

[0021] Preferably, when the evaporation rate is detected to be continuously decreasing and it is difficult to maintain the target rate by increasing the power, the material is determined to be exhausted, and an instruction is generated to smoothly reduce the power to stop.

[0022] A vacuum coating system, comprising:

[0023] Real-time sensing module: During the coating process, it continuously collects and fuses key real-time parameters that reflect the working status of the electron gun and the evaporation process. The key real-time parameters include at least the real-time temperature distribution and real-time evaporation rate of the electron beam spot area.

[0024] Intelligent decision-making module: Based on key real-time parameters, it evaluates the current coating status in real time and, in conjunction with preset coating process requirements, dynamically generates the electron beam control target instruction set for the next control cycle through a built-in decision-making mechanism; the instruction set includes: power target value, focus status target value, and scanning path target trajectory;

[0025] Multivariable collaborative dynamic control module: The generated power target value, focus state target value and scan path target trajectory command are synchronously sent to the power controller, focus coil controller and scan coil controller of the electron gun, driving the electron gun to adjust its power output, focus state and scan motion in real time.

[0026] The beneficial effects of this invention are as follows:

[0027] 1. The electron gun control method and system for a vacuum coating machine described in this invention achieves precise and stable control of the evaporation rate: through a strong closed loop between power and evaporation rate, it effectively addresses changes in material properties; the dynamically planned scanning path can actively compensate for the non-uniformity of the crucible's thermal field, and combined with focusing adjustment to optimize the beam spot energy distribution, it significantly improves the uniformity of the thermal field.

[0028] 2. The electron gun control method and system for a vacuum coating machine described in this invention can effectively suppress sputtering by actively reducing local power density or changing scanning strategy during the melting stage and when overheating risk is detected. It enhances the adaptability to complex processes and provides a more flexible and faster control means for precise control of film structure (such as rapid switching of evaporation source and gradient deposition). Attached Figure Description

[0029] The invention will now be further described with reference to the accompanying drawings.

[0030] Figure 1 This is a flowchart of a method for controlling an electron gun in a vacuum coating machine according to the present invention;

[0031] Figure 2 This is a system block diagram of an electron gun control system for a vacuum coating machine according to the present invention. Detailed Implementation

[0032] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0033] Example 1

[0034] like Figure 1 As shown in the embodiment of the present invention, a method for controlling the electron gun of a vacuum coating machine includes the following steps:

[0035] A1. Real-time sensing and data fusion: During the coating process, key real-time parameters reflecting the working status of the electron gun and the evaporation process are continuously collected and fused. The key real-time parameters include at least the real-time temperature distribution and real-time evaporation rate of the electron beam spot area.

[0036] It needs to be explained that dynamic acquisition refers to the continuous monitoring and acquisition of core parameters reflecting the electron gun's operating status and the evaporation process during the coating process. This includes at least:

[0037] The real-time temperature distribution of the electron beam spot is directly measured by sensors (such as thermocouples or infrared thermometers) mounted on the electron gun.

[0038] The real-time evaporation rate is obtained through an evaporation rate monitoring device (such as a quartz crystal oscillator QCM or an optical monitor).

[0039] Information fusion: This involves preprocessing these multi-source, heterogeneous real-time monitoring data through filtering and calibration, and potentially extracting features (such as identifying hotspot regions in the beam spot temperature distribution and calculating the gradient of evaporation rate changes) to provide accurate and reliable input information for subsequent intelligent decision-making. This step forms the perceptual foundation of the entire control strategy, and its accuracy directly impacts the effectiveness of subsequent decisions.

[0040] A2. Intelligent Decision-Making and Target Generation: Based on key real-time parameters, the current coating status is evaluated in real time, and combined with preset coating process requirements, the built-in decision-making mechanism dynamically generates the electron beam control target instruction set for the next control cycle. The instruction set includes:

[0041] (i) The desired target value of electron beam power;

[0042] (ii) Target value of the desired electron beam focusing state;

[0043] (iii) The desired electron beam scanning path target trajectory; wherein the scanning path target trajectory is dynamically planned and generated based on the currently sensed crucible surface temperature distribution and material state, aiming to optimize thermal field uniformity, evaporation stability and suppress splashing;

[0044] It needs to be explained that: Status assessment: Based on the fusion data processed in step A1, the current coating status is assessed in real time. The assessment includes:

[0045] Evaporation stability: Whether the current evaporation rate is within the set target range;

[0046] Beam morphology and thermal field uniformity: Whether the beam temperature distribution is uniform, and whether there are local overheated (easily leading to splashing) or undercooled (insufficient evaporation) areas;

[0047] Material consumption stage: Based on the trend of evaporation rate change and spot characteristics, it is preliminarily determined whether the material is in the initial melting stage, the stable evaporation stage, or the depletion stage.

[0048] Target Generation: Based on the above state assessment results, preset coating process requirements (such as target evaporation rate, film thickness uniformity index, and splash suppression requirements), and the built-in optimization rule base / model (such as fuzzy logic controller, PID controller, or machine learning-based predictive model), the electron beam control target instruction set for the next control cycle is dynamically generated. These instruction sets are specifically defined as follows:

[0049] Desired target electron beam power: used to adjust the evaporation rate to the desired level.

[0050] Desired target value for electron beam focusing state: used to optimize beam spot size and energy density distribution, and improve thermal field uniformity.

[0051] The desired electron beam scanning path target trajectory is no longer a simple fixed pattern, but a scanning path dynamically planned based on the current thermal field distribution inside the crucible (mapped by the beam spot temperature) and the material state.

[0052] For example, in identified overheated areas, the system can actively slow down or reduce power density to dissipate heat; in areas with insufficient evaporation, it can accelerate or increase power density scanning to promote evaporation; and in the early stages of material melting, it can use low power, large beam size, and specific avoidance paths to ensure smooth melting and reduce the risk of splashing. The perceived state is then translated into specific, optimized control objectives.

[0053] A3. Multi-variable collaborative dynamic control: The generated power target value, focus state target value, and scanning path target trajectory command are synchronously sent to the power controller, focus coil controller, and scanning coil controller of the electron gun, driving the electron gun to adjust its power output, focus state, and scanning motion in real time; at the same time, the real-time sensing data continuously processed in step A1 forms a closed-loop feedback and is input to step A2, thereby realizing continuous adaptive optimization of electron beam behavior.

[0054] It needs to be explained that the coordinated execution means that the power target value, focus target status and scan path target trajectory command generated in step A2 are synchronously sent to the power controller, focus coil controller and scan coil controller of the electron gun.

[0055] Dynamic adjustment: After receiving instructions, each controller adjusts its output in real time to drive the corresponding components of the electron gun to operate.

[0056] The power controller adjusts the filament current or accelerating voltage to bring the electron beam power closer to the target value.

[0057] The focusing controller adjusts the current in the focusing coil to change the magnetic field strength, so that the electron beam focusing state meets the target requirements (such as beam spot size and shape).

[0058] The scanning controller precisely controls the current change of the scanning coil according to the dynamically planned path trajectory, guiding the electron beam to move on the crucible surface along the optimized path.

[0059] Closed-loop feedback: The real-time sensing data from step A1 is continuously fed back, forming a closed-loop control system. The system constantly compares the current state (sensing data) with the desired target (instructions generated in step 2), and calculates new control instructions through the intelligent decision-making mechanism of step A2 (executed in step A3). This process is repeated continuously to achieve continuous and adaptive optimization of the electron beam behavior throughout the coating process. This ensures that intelligent decisions can act accurately and synchronously on the electron gun, forming a closed-loop feedback loop.

[0060] Specifically, in step A2, the real-time temperature distribution of the electron beam spot area is obtained by a non-contact temperature measuring device, which is an infrared thermal imager or a pyrometer; in step A1, the real-time evaporation rate is obtained by an evaporation rate monitoring device, which is a quartz crystal oscillator or an optical monitoring device.

[0061] Specifically, in step A2, the real-time assessment of the current coating status includes: assessing the stability of the evaporation rate, assessing the uniformity of the electron beam spot temperature distribution and identifying local overheating or undercooling areas, and determining the material consumption stage.

[0062] Specifically, step A2 involves real-time evaluation of the current coating status, including:

[0063] Evaporation rate stability assessment: Calculate the standard deviation of the real-time evaporation rate within a set time window. When it exceeds the threshold (set manually based on historical experience), it is judged to be in an unstable state.

[0064] Temperature distribution uniformity assessment: Scan the temperature distribution map of the electron beam spot area, identify overcooled or overheated areas that exceed the set temperature range, and calculate the area ratio of abnormal areas. When the area ratio of abnormal areas exceeds the area ratio threshold (the area ratio threshold is set manually based on historical experience), it is judged as a non-uniform state.

[0065] Material consumption stage judgment: If the evaporation rate continues to decrease and the power regulation efficiency is lower than the set value, it is determined that the material depletion stage has been entered.

[0066] Specifically, in step A2, the built-in decision-making mechanism includes at least one of fuzzy logic control, PID control, or a machine learning-based predictive control model.

[0067] Specifically, the target trajectory of the scanning path is dynamically planned and generated based on the currently sensed temperature distribution on the crucible surface and the material state, as follows:

[0068] In areas identified as having excessively high temperatures, the plan is to reduce the scanning speed or power density dwell time, or to proceed quickly; in areas identified as having excessively low temperatures or insufficient evaporation, the plan is to increase the scanning speed or power density, or to increase the local scanning density or to perform reciprocating scanning.

[0069] Specifically, in the initial stage of material melting, the instruction set generated in step A2 is as follows: set a lower initial power target value, set a larger beam spot focusing state target value, and plan an initial scanning path target trajectory that avoids the easily overheated area in the center of the crucible, so as to smoothly melt the material and suppress splashing.

[0070] 8. The electron gun control method for a vacuum coating machine according to claim 1, characterized in that, in step A3, after receiving the instruction, the power controller, the focusing coil controller and the scanning coil controller perform real-time adjustments, and their adjustment processes are interconnected and are coordinated and controlled by the target instruction set output by the same decision-making mechanism.

[0071] Specifically, it also includes determining that the material is about to run out when the evaporation rate is detected to be continuously decreasing and it is difficult to maintain the target rate by increasing the power, and generating an instruction to smoothly reduce the power to stop.

[0072] Example 2

[0073] like Figure 2 As shown in the comparative embodiment one, another embodiment of the present invention is: a vacuum coating system, including...

[0074] Real-time sensing module: During the coating process, it continuously collects and fuses key real-time parameters that reflect the working status of the electron gun and the evaporation process. The key real-time parameters include at least the real-time temperature distribution and real-time evaporation rate of the electron beam spot area.

[0075] Intelligent decision-making module: Based on key real-time parameters, it evaluates the current coating status in real time and, in conjunction with preset coating process requirements, dynamically generates the electron beam control target instruction set for the next control cycle through a built-in decision-making mechanism; the instruction set includes: power target value, focus status target value, and scanning path target trajectory;

[0076] Multivariable collaborative dynamic control module: The generated power target value, focus state target value and scan path target trajectory command are synchronously sent to the power controller, focus coil controller and scan coil controller of the electron gun, driving the electron gun to adjust its power output, focus state and scan motion in real time.

[0077] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for controlling an electron gun of a vacuum coating machine, characterized in that: The method comprises the following steps: A1. During the coating process, continuously collect and fuse process key real-time parameters reflecting the working state of the electron gun and the evaporation process, the key real-time parameters at least including real-time temperature distribution of the electron beam spot action area and real-time evaporation rate; A2. Based on the key real-time parameters, real-time evaluate the current coating state, and combine the preset coating process requirements, through the built-in decision mechanism, dynamically generate the electron beam control target instruction set of the next control cycle, the instruction set including: power target value, focusing state target value and scanning path target trajectory; wherein, the scanning path target trajectory is dynamically planned and generated according to the current perceived crucible surface temperature distribution and material state, for optimizing thermal field uniformity, evaporation stability and suppressing spitting; A3. The generated power target value, focusing state target value and scanning path target trajectory instructions are synchronously sent to the power controller, focusing coil controller and scanning coil controller of the electron gun, to drive the electron gun to real-time adjust its power output, focusing state and scanning motion.

2. The vacuum coater electron gun control method of claim 1, wherein, In step A2, the real-time temperature distribution of the electron beam spot action area is obtained by a non-contact temperature measuring device, which is an infrared thermal imager or a pyrometer; in step A1, the real-time evaporation rate is obtained by an evaporation rate monitoring device, which is a quartz crystal oscillator or an optical monitoring device.

3. The vacuum coater electron gun control method of claim 1, wherein, In step A2, the real-time evaluation of the current coating state includes: evaluating the stability of the evaporation rate, evaluating the uniformity of the electron beam spot temperature distribution and identifying local overheating or supercooling areas, and judging the consumption stage of the material.

4. The vacuum coater electron gun control method of claim 3, wherein, In step A2, the real-time evaluation of the current coating state includes: Evaporation rate stability evaluation: calculate the standard deviation of the real-time evaporation rate within a set time window, and determine as unstable state when exceeding the threshold value; Temperature distribution uniformity evaluation: scan the temperature distribution of the electron beam spot action area, identify the supercooling or overheating area exceeding the set temperature range, and calculate the area ratio of the abnormal area, and determine as non-uniform state when the area ratio of the abnormal area exceeds the area ratio threshold value; Material consumption stage judgment: if the evaporation rate continues to decrease and the power adjustment efficiency is lower than the set value, it is determined to enter the material depletion stage.

5. The vacuum coater electron gun control method of claim 1, wherein, In step A2, the built-in decision mechanism includes at least one of fuzzy logic control, PID control or prediction control model based on machine learning.

6. The vacuum coater electron gun control method of claim 1, wherein, The scanning path target trajectory is dynamically planned and generated according to the current perceived crucible surface temperature distribution and material state, specifically: In the identified temperature high area, plan to reduce the scanning speed or reduce the power density residence time, or plan to pass quickly; in the identified temperature low or evaporation insufficient area, plan to increase the scanning speed or increase the power density scanning, or plan to increase the local scanning density or reciprocating scanning.

7. The vacuum coater electron gun control method of claim 1, wherein, In the initial stage of material melting, the instruction set generated by step A2 is: set a lower initial power target value, set a larger focusing state target value of the beam spot, and plan an initial scanning path target trajectory to avoid the easy overheating area in the center of the crucible, to smoothly melt the material and suppress spitting.

8. The vacuum coater electron gun control method of claim 1, wherein, In step A3, the power controller, focusing coil controller and scanning coil controller receive instructions and make real-time adjustments, which are interrelated and controlled by the same target instruction set output by the decision mechanism.

9. The vacuum coater electron gun control method of claim 1, wherein, Also included is a judgment that the material will be exhausted and a generation of instructions to smoothly reduce the power to stop when a sustained decrease in the evaporation rate is monitored and it is difficult to maintain the target rate by increasing the power.

10. A vacuum coating system for carrying out the vacuum coating machine electron gun control method according to any one of claims 1-9, characterized in that, Including Real-time sensing module: during the coating process, key real-time parameters reflecting the working state of the electron gun and the evaporation process are continuously collected and fused, including at least the real-time temperature distribution of the electron beam spot action area and the real-time evaporation rate; Intelligent decision module: based on the key real-time parameters, the current coating state is evaluated in real time, and the preset coating process requirements are combined to dynamically generate the electron beam control target instruction set for the next control period through the built-in decision mechanism; the instruction set includes: power target value, focusing state target value and scanning path target trajectory; Multivariate coordinated dynamic regulation module: the generated power target value, focusing state target value and scanning path target trajectory instructions are synchronously sent to the power controller, focusing coil controller and scanning coil controller of the electron gun to drive the electron gun to adjust its power output, focusing state and scanning motion in real time.

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