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CN-121357803-B - Automatic optimization method for laser drilling path of circuit board

CN121357803BCN 121357803 BCN121357803 BCN 121357803BCN-121357803-B

Abstract

The invention relates to the field of data processing, in particular to an automatic optimization method for a laser drilling path of a circuit board, which introduces a double pheromone ant colony algorithm aiming at the defect that the traditional algorithm only pursues the shortest path and ignores the heat accumulation effect. By constructing two independent pheromones of path length and heat distribution, defining a hole site neighborhood heat influence factor and a path global thermal entropy to quantify heat dissipation performance, guiding an algorithm to simultaneously consider distance and heat during path selection, effectively balancing processing efficiency and heat control, avoiding the algorithm from sinking into suboptimal solution due to local heat concentration, and finally finding a comprehensive optimal path considering both path length and heat dissipation effect. The invention constructs and independently updates two pheromones of path length and heat distribution by adopting a double pheromone ant colony algorithm so as to balance the control of the drilling path length and heat and find the optimal solution.

Inventors

  • WANG HUI

Assignees

  • 江西弘高科技有限公司

Dates

Publication Date
20260508
Application Date
20250929

Claims (10)

  1. 1. The automatic optimizing method for the laser drilling path of the circuit board is characterized by comprising the steps of obtaining two-dimensional coordinates of all drilling points on the circuit board to be processed; acquiring a hole site neighborhood heat influence factor for representing local heat concentration risk in a drilling process, wherein the value of the hole site neighborhood heat influence factor is inversely proportional to Euclidean distance between any two hole sites and is directly proportional to the sum of local densities of the two hole sites; Acquiring a path global thermal entropy for quantifying the heat dissipation performance of the whole drilling path, and calculating the distribution uniformity of hole site neighborhood heat influence factors of each step in the path based on an information entropy theory; After each iteration of the algorithm is finished, the double pheromones are independently decoupled and updated, the updating amount of the path length pheromones is inversely proportional to the total length of the paths generated by the iteration, and the updating amount of the heat distribution pheromones is directly proportional to the global thermal entropy of the paths; And repeating the updating process until the termination condition is met, and outputting the processing path with the shortest length which meets the preset global thermal entropy minimum value in all iterations.
  2. 2. The automatic optimization method for the laser drilling path of the circuit board according to claim 1, wherein the calculation method for the hole site neighborhood heat influence factor is specifically as follows: ; Wherein the method comprises the steps of Representing a hole site neighborhood heat influence factor; And Respectively denoted as hole sites And hole site Is a local density of (2); representing a set distance reference value; Representing the hole site And Euclidean distance between them; representing a very small positive real number, for preventing the denominator from being zero.
  3. 3. The method for automatically optimizing laser drilling paths of circuit board according to claim 2, wherein a radius is set To position the target hole site The number of holes already present in the neighborhood is taken as its local density.
  4. 4. The method for automatically optimizing laser drilling paths of a circuit board according to claim 3, wherein an average value of nearest neighbor distances of all hole sites on the circuit board is calculated and the radius is calculated Set as average of nearest neighbor distances Multiple of (a) wherein Is a preset constant, and the value range is 2 to 5.
  5. 5. The automatic optimization method for the laser drilling path of the circuit board according to claim 1, wherein the calculation method for the global thermal entropy of the path is specifically as follows: ; Wherein the method comprises the steps of Representing the global thermal entropy of the path; The number of the total holes is; Represent the first And normalizing the duty ratio of the hole site neighborhood heat influence factors in the sum of all the hole site neighborhood heat influence factors in the whole path.
  6. 6. The automatic optimization method of laser drilling paths of a circuit board according to claim 1, wherein in the ant colony algorithm, a probability model of ants when selecting a next unvisited hole site is: ; Wherein the method comprises the steps of Representing a selection probability; Is shown in the first At the time of iteration, the path The path length pheromone concentration on the substrate; representing the reciprocal of the distance of the heuristic information; Is shown in the first At the time of iteration, the path The concentration of the thermal profile pheromone; Respectively representing setting three weight parameters; Representing ants A set of holes that have not been accessed.
  7. 7. The method of claim 1, wherein the update to the heat distribution pheromone is further proportional to a scaling factor used to balance the rewards of two pheromones.
  8. 8. The method for automatically optimizing a laser drilling path of a circuit board according to claim 7, wherein the method for determining the scaling factor comprises: Generating a plurality of random drilling paths before the main circulation of the algorithm starts; Calculating average path lengths and average global thermal entropy of the plurality of random drilling paths; The scaling factor is taken as the ratio of 1 to the product of the average path length and the average global thermal entropy.
  9. 9. The method of claim 1, wherein the update of the pheromone by decoupling further comprises a volatilization process by multiplying the current pheromone concentration by a volatilization coefficient in the range of (0, 1).
  10. 10. The method of claim 1, wherein the termination condition is that a predetermined maximum number of iterations is reached.

Description

Automatic optimization method for laser drilling path of circuit board Technical Field The invention relates to the field of data processing, in particular to an automatic optimization method for a laser drilling path of a circuit board. Background In the high density manufacturing process of printed circuit boards, laser drilling is a key technology, and its efficiency and quality directly affect the final product performance. In order to improve the production efficiency, the processing sequence of tens of thousands of drilling points is usually required to be subjected to path optimization, and the optimized drilling path aims at finding the shortest path traversing all the drilling points so as to shorten the total stroke of the laser head and reduce the processing time. However, laser drilling is accompanied by high energy transient injection, which generates significant heat at the point of machining and its surrounding areas. If the drilling path planning only pursues the shortest distance, the laser head is likely to work densely continuously in a certain local area, and serious heat accumulation effect is caused. Such localized overheating may not only damage the substrate material of the circuit board, but may also affect the quality and electrical performance of the hole wall. Therefore, an ideal drilling path must not only consider the economy of the path length, but also the uniformity of heat distribution during processing, avoiding the generation of local hot spots. How to balance the two conflicting objectives of path minimization and heat dissipation constitutes a great challenge in the current art. For such a path optimization problem, the ant colony algorithm is a widely used heuristic search algorithm. The conventional ant colony algorithm guides the search direction through a single information element based on the path length, and can effectively find a shorter path. However, in laser drilling scenarios, the inherent disadvantage is also evident in that since the excitation mechanism of the algorithm is entirely dependent on path length, it will inevitably tend to select locally closely spaced path segments, resulting in a drilling sequence that is spatially too concentrated. This optimization trend makes it easy for the algorithm to converge to a suboptimal solution that, although short in path, presents a serious risk of localized heat accumulation, failing to meet the high quality, high reliability production requirements. Disclosure of Invention Aiming at the problem that the ant colony algorithm is easy to converge to a suboptimal solution with a short path but serious local heat accumulation risk, the invention provides an automatic optimization method for a laser drilling path of a circuit board, which comprises the steps of obtaining two-dimensional coordinates of all drilling points on the circuit board to be processed, obtaining a hole site neighborhood heat influence factor for representing local heat concentration risk in the drilling process, wherein the value of the hole site neighborhood heat influence factor is inversely proportional to Euclidean distance between any two holes and is directly proportional to the sum of local densities of the two holes, obtaining a path global heat entropy for quantifying the heat radiation performance of the whole drilling path, calculating the distribution uniformity of the hole site neighborhood heat influence factor in each step in the path based on an information entropy theory, carrying out path searching by adopting an ant colony algorithm based on double pheromones, wherein the double pheromones comprise a path length pheromone for guiding searching a short path and a heat distribution pheromone for guiding searching a path with high heat radiation performance, carrying out independent decoupling updating on the double pheromone after each round of iteration of the algorithm is finished, and the updating quantity of the path length pheromone is inversely proportional to the total length heat distribution information generated by the iteration round of the algorithm. And repeating the updating process until the termination condition is met, and outputting the processing path with the shortest length which meets the preset global thermal entropy minimum value in all iterations. In the prior art, when planning a laser drilling path of a circuit board, only the shortest path is usually used as a single optimization target, which can improve the processing efficiency, but the risk of local heat accumulation caused by too concentrated holes in the drilling process is easily ignored, and the defects of layering, carbonization and the like of the circuit board can be caused, so that the product yield is affected. According to the invention, two indexes of a hole site neighborhood heat influence factor and a path global thermal entropy are introduced to evaluate the heat dissipation performance of a drilling path, and a double pheromone a