A method for laser fabrication of large area high density micro-hole array

Abstract

The application discloses a method for laser manufacturing large-area high-density micro-hole array, and relates to the technical field of laser processing. The method is: ①using a rectangular segmentation method to divide the processing area into grids, and obtaining standard modules and non-standard modules through image recognition; ②for the standard modules, solving a generalized traveling salesman problem based on a simulated annealing algorithm to optimize the punching order path, and obtaining an optimal path through multiple iterations; or ③for the non-standard modules, solving a traveling salesman problem with constraints to optimize the path, and discontinuously processing two adjacent non-standard modules; ④ regarding each module as a single unit, laser processing through the optimal path obtained in steps ② and ③, planning the processing order of all modules of the processing area based on the traveling salesman problem with constraints, and obtaining an optimal path, namely, re-dividing the modules. The application is suitable for applications requiring laser manufacturing of large-area high-density micro-hole array in the technical field of laser processing.

Description

Technical Field

[0001] This invention relates to the field of laser processing technology, and more specifically, to a method for fabricating large-area, high-density micro-hole arrays using lasers. Background Technology

[0002] In laser processing, when fabricating large-area, high-density micro-hole arrays, the small diameter, large number of micro-holes, and close spacing between them lead to localized heat accumulation in the material, resulting in defects such as carbonization, deformation, and ablation. Besides heat accumulation, heat also diffuses during processing. Therefore, when fabricating adjacent micro-holes, it's crucial to consider whether the heat generated by the previous micro-hole has completely diffused to avoid heat accumulation. However, simply pursuing complete elimination of heat accumulation while neglecting processing time significantly reduces processing efficiency. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings and deficiencies of the existing technology and provide a method for laser fabrication of large-area high-density micro-hole arrays. This method can not only efficiently fabricate large-area high-density micro-hole arrays, but also take into account the problem of heat accumulation, thereby improving processing efficiency.

[0004] The objective of this invention is achieved as follows:

[0005] ① The processing area is divided into grids using the rectangular segmentation method, and standard and non-standard modules are obtained through image recognition;

[0006] ② For the standard module, the generalized traveling salesman problem is solved based on the simulated annealing algorithm. The punching sequence path is optimized, and an optimal path is obtained through multiple iterations.

[0007] ③ For non-standard modules, path optimization is performed by solving the constrained traveling salesman problem, and two adjacent non-standard modules are not processed consecutively;

[0008] ④ Treat each module as a single unit, and perform laser processing using the preferred path obtained in steps ② and ③. Solve the traveling salesman problem with constraints to plan the processing sequence of all modules in the processing area, and obtain a preferred path, that is, divide the modules again.

[0009] This invention has the following advantages and positive effects:

[0010] ① Efficient fabrication of large-area high-density micro-hole arrays: This invention can efficiently fabricate large-area high-density micro-hole arrays by using methods such as rectangular segmentation, simulated annealing algorithm, and solving constrained traveling salesman problem, which can significantly improve processing efficiency in the field of micro-machining;

[0011] ② Considering the problem of heat accumulation: In laser processing, heat accumulation often leads to material deformation or damage. This invention optimizes the drilling sequence path to better control the problem of heat accumulation, thereby reducing material damage and improving processing quality;

[0012] ③ Modular processing: This invention divides the processing area into standard modules and non-standard modules, and then optimizes the path planning and laser processing for each module. This modular processing method makes the processing process more flexible and is suitable for workpieces of different shapes and sizes.

[0013] ④ Wide applicability: The method of this invention can be widely applied to the fabrication of micropore arrays, such as microelectronic devices, biomedical devices, microfluidic devices, etc.; it provides a universal fabrication method that is applicable to various materials and applications.

[0014] This invention is applicable to the following fields:

[0015] A. Microelectronic devices: Semiconductor material processing that can be used to fabricate micro-hole arrays, including micro-vias in chip manufacturing;

[0016] B. Biomedical devices: These can be used to manufacture medical devices that require microporous structures, such as biochips and drug delivery systems.

[0017] C. Microfluidic devices: Suitable for fabricating microfluidic chips for microfluidic applications such as biological analysis and chemical reactions;

[0018] D. Materials processing: It can be used to create micropores in materials such as metals and ceramics, and can be extended to the manufacturing field;

[0019] E. Optical elements: suitable for the micro-machining of optical devices, such as gratings and lenses.

[0020] In summary, the method of the present invention provides a multifunctional and efficient laser fabrication technique for large-area, high-density micropore arrays, which can play an important role in multiple fields. Attached Figure Description

[0021] Figure 1-0 This is the overall flowchart of this method;

[0022] Figure 1-1 This is a flowchart of step ① of this method;

[0023] Figure 1-2 This is a flowchart of step ② of this method;

[0024] Figure 1-3 This is a flowchart of step ③ of this method;

[0025] Figure 1-4 This is a flowchart of step ④ of this method;

[0026] Figure 2 A schematic diagram of module division;

[0027] Figure 3 The flowchart for iterating the optimal path according to the generalized traveling salesman problem using the simulated annealing algorithm (detailed steps of step dS24);

[0028] Figure 4 This is a schematic diagram of the default laser processing sequence path;

[0029] Figure 5 This is a schematic diagram of the processing sequence path for the first random 10×10 micro-hole array;

[0030] Figure 6 To find the optimal path using simulated annealing algorithm iteratively 1000 times according to the generalized traveling salesman problem;

[0031] Figure 7 This is a schematic diagram of the heat-affected zone in simulation software for laser-processed microholes on polyimide.

[0032] Figure 8 A diagram illustrating the further division of modules. Detailed Implementation

[0033] The following is a detailed description with reference to the accompanying drawings and embodiments:

[0034] I. Methods

[0035] like Figure 1-0 The method is as follows:

[0036] Multiple modules are divided using a matrix partitioning method. Standard and non-standard modules are determined based on the number of micropores within each module. Then, the generalized traveling salesman problem is solved using a simulated annealing algorithm to achieve optimal path selection for a single standard module. For non-standard modules, the damage radius D of a single micropore on the processing material is calculated using simulation software. The non-standard modules are then partitioned by solving a constrained traveling salesman problem. During processing, adjacent modules should be processed as discontinuously as possible. This minimizes heat accumulation and ensures a certain level of processing efficiency when laser-processing high-density micropore arrays.

[0037] Specifically:

[0038] Fabricating a large-area, high-density microporous array on a 100mm × 100mm polyimide film, including:

[0039] ① The processing area is divided into grids using the rectangular segmentation method to obtain standard modules and non-standard modules - S1;

[0040] ② For the standard module, the traveling salesman problem is solved based on the simulated annealing algorithm to optimize the drilling sequence path. Through the simulated annealing algorithm, an optimal path is obtained, which takes into account the processing time as short as possible within the acceptable range of thermal accumulation energy - S2;

[0041] ③ For non-standard modules, path optimization is performed by solving a constrained traveling salesman problem. Two adjacent non-standard modules are not processed consecutively; this reduces the impact of residual heat after completing the entire module on the next module - S3:

[0042] ④ All standard modules are processed according to the optimized path to minimize the heat accumulation problem. Two adjacent standard modules are processed discontinuously - S4.

[0043] 1. Step ①

[0044] Step ① specifically involves the rectangle segmentation module; refer to... Figure 2 .

[0045] like Figure 1-1 ,

[0046] A. Use the rectangular division method to divide the 10mm×10mm plane to be processed into multiple modules of 1mm×1mm size, with each small square representing a module - S11;

[0047] B. Set the diameter of each micropore to 0.084 mm and the spacing between pores to 0.1 mm - S12;

[0048] 2. Step ②

[0049] Step ② specifically involves obtaining an optimized path based on the simulated annealing algorithm according to the Traveling Salesman Problem. See [link to relevant documentation]. Figure 3 .

[0050] like Figure 1-2 ,

[0051] The specific process of step ②S2 is as follows:

[0052] a. Plan a random path within a single standard module, traversing each processing unit (micro-hole) within the module once. This path is the initial path, named R1(S21). See [link / reference]. Figure 4 ;

[0053] b. Obtain the highest accumulated heat temperature (T) of R1 through experiments. R1 ) and processing time (t) R1 (S22);

[0054] c. Randomly swap the positions of two random points in path R1 to obtain a new path, named R2. Obtain the highest cumulative heat temperature (T) experimentally.R2 ) and processing time (t) R2 (S23), see Figure 4 , Figure 5 ;

[0055] d. Compare T R1 and T R2 , and t R1 and t R2 ,

[0056] If T R1 <T R2 , and t R1 <t R2 If path R2 is discarded, a new path is obtained by randomly swapping the positions of two random points in path R1, which is different from the discarded path, and named R2.

[0057] If T R1 >T R2 , and t R1 >t R2 If R1 is discarded, R2 is renamed R1. A new path is obtained by randomly swapping the positions of two random points in the R1 path, which is different from the discarded path, and is named R2.

[0058] If T R1 >T R2 , and t R1 <t R2 , or T R1 <T R2 , and t R1 >t R2 ,like If path R1 is discarded, R2 is renamed to R1. A new path, different from the discarded path, is obtained by randomly swapping the positions of two random points in path R1 and named R2. Otherwise, path R2 is discarded and a new path, different from the discarded path, is obtained by randomly swapping the positions of two random points in path R1 and named R2 (S24).

[0059] e. Repeat step d, setting the iteration count of step d to 1000, and output the optimal path R1 (S25). See [link / reference]. Figure 6 .

[0060] 3. Step ③

[0061] See Figure 7 ;

[0062] The specific process of step ③ (S3) is as follows:

[0063] I. Based on the material properties, simulate the heat-affected zone of a single micro-hole in the simulation software, and define the radius of the heat-affected zone as D(S31);

[0064] II. In the non-standard module, by solving the constrained traveling salesman problem, that is, when solving the traveling salesman problem, the points selected in two consecutive times need to be greater than 2D (S32);

[0065] 4. Step ④

[0066] The specific process of step ④ (S4) is as follows:

[0067] i. Process all modules following the principle of discontinuous processing of adjacent modules (S41), see [link / reference]. Figure 8 ;

[0068] ii. Convert the path information obtained in step ② (S2) into a file that can be processed by the laser processing system (S42);

[0069] iii. Import the file into the laser processing system (S43);

[0070] iv. Place the pre-made sample on the laser processing platform, align the laser focus on the sample surface, and begin processing (S44);

[0071] v. After processing is completed, measure the temperature of the processing area and record the processing time (S45).

[0072] II. Working Mechanism of this Method

[0073] The working mechanism of this method is to combine image recognition, simulated annealing algorithm, and constrained traveling salesman problem solving to achieve an efficient method for laser fabrication of large-area, high-density micro-hole arrays. The working process is explained in detail below:

[0074] 1. Mesh Generation and Module Classification (S1): First, the area to be processed is divided into small modules using the rectangular segmentation method; then, standard modules and non-standard modules are distinguished by image recognition technology; standard modules usually have regular shapes, while non-standard modules are irregular.

[0075] 2. Optimized path calculation for standard modules (S2): For standard modules, the simulated annealing algorithm is used to solve the generalized traveling salesman problem. This means finding an optimal drilling sequence path to minimize the total path length of laser drilling. The simulated annealing algorithm continuously improves the path through multiple iterations to obtain the optimal solution.

[0076] 3. Path optimization for non-standard modules (S3): For non-standard modules, a constrained traveling salesman problem solution method is used to ensure that two adjacent non-standard modules do not undergo continuous processing; this effectively reduces the occurrence of heat accumulation problems.

[0077] 4. Module Processing Planning (S4): Each module is considered a unit. The optimal paths obtained through steps ② and ③ are integrated to plan the processing sequence of all modules within the entire processing area; this ultimately produces a globally optimal path to ensure efficient laser processing; this step also involves further subdividing the modules to optimize the overall path.

[0078] This invention fully considers the problem of heat accumulation through this method, making the laser fabrication of large-area, high-density micro-hole arrays more efficient and overcoming the shortcomings and deficiencies of existing technologies.

Claims

1. A method for laser manufacturing large-area high-density micro-hole array, comprising the following steps: ① Using rectangular segmentation method to divide the processing area into grid, and obtaining standard module and non-standard module through image recognition (S1); ② For the standard module, solving the generalized traveling salesman problem based on simulated annealing algorithm to optimize the punching order path, and obtaining an optimal path through multiple iterations (S2); ③ For the non-standard module, solving the traveling salesman problem with constraints to optimize the path, and discontinuously processing two adjacent non-standard modules (S3); ④ Treating each module as a single unit, and laser processing through the optimal path obtained in steps ② and ③, planning the processing order of all modules in the processing area based on the traveling salesman problem with constraints, and obtaining an optimal path, i.e., re-dividing the modules (S4); The specific process of step ② (S2) is as follows: a. Plan a random path in a single standard module, and each processing unit in the module, i.e., micro-hole, traverses once, which is the initial path, named R1 (S21); b. Obtain the thermal cumulative maximum temperature T of R1 through experiment R1 and processing time t R1 ; c. Randomly exchange the positions of two random points in the R1 path to obtain a new path, named R2, and obtain the highest thermal accumulation temperature T of R2 through experiments R2 and processing time t R2 (S23); d, compare T R1 and T R2 and t R1 and t R2 , If T R1 <T R2 , and t R1 <t R2 , the R2 path is abandoned, a new path is obtained by randomly exchanging the positions of two random points in the R1 path, which is different from the abandoned path, and is named R2. If T R1 > T R2 , and t R1 > t R2 , then R1 path is abandoned, and R2 is named as R1, and a new path is obtained by randomly exchanging the positions of two random points in the R1 path, which is different from the abandoned path and is named as R2; If T R1 > T R2 , and t R1 < t R2 , or T R1 < T R2 , and t R1 > t R2 , if then R1 path is discarded, and R2 is renamed as R1, a new path is obtained by randomly exchanging the positions of two random points in the R1 path, which is different from the discarded path, and is named as R2; otherwise, R2 path is discarded, and a new path is obtained by randomly exchanging the positions of two random points in the R1 path, which is different from the discarded path, and is named as R2 (S24). e. Repeat step d, set the iteration number of step d, and output the optimal path R1 (S25).

Images