Year: 2026
Type: article
Abstract: Printed Circuit Board manufacturing is a key sector of modern electronics industry where improving the throughput of microvia drilling operations is of paramount importance. One effective solution is maskless laser technology which provides high accuracy and processing flexibility. However, its bottleneck remains the beam positioning speed, limited by the inertia of galvanometer-based scanners. This work proposes a hybrid control method for microvia laser drilling that combines a galvanometer-based scanner and an acousto-optic deflector. The set of vias is pre-partitioned into clusters so that all vias within each cluster can be processed by the acousto-optic deflector inside its deflection field without involving the galvanometer. Cluster centers are then connected by a minimal trajectory computed using a combination of a greedy algorithm and the pairwise exchange method (2-opt) which minimizes the total travel length of the galvanometer and the overall drilling cycle time. This approach enables coordinated use of the high-speed acousto-optic deflector for local processing and the long-range galvanometer for movements between clusters. Implementation of the proposed method reduced the galvanometer travel length from 3,097.05 mm to 1,674.19 mm and decreased the total processing time by more than a factor of 3.3 compared with traditional approaches. The effect is achieved by minimizing the number of large inertial moves and shifting a portion of the motion tasks to the high-speed acousto-optic deflector. Unlike known approaches that optimize a single traveling salesman problem route over all vias, the proposed method realizes a hierarchical routing scheme. Classical methods minimize route length but do not account for the dynamic limitations of the galvanometer which leads to excessive inertial moves. Pure acousto-optic deflector based systems provide very high speed but are limited by a small deflection field. The hybrid approach combines advantages of both technologies: the acousto-optic deflector delivers high-speed processing within clusters, while the galvanometer performs efficient transitions between them. The method requires no substantial hardware modifications, can be integrated into existing control systems, and is adaptable to microprocessing of glass substrates (for through glass vias) for 2.5D and 3D packaging architectures.
Language: English
Subfield: Industrial and Manufacturing Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W7131908559