Developing markets, such as hydrogen electrolysis or the battery industry, increasingly require thin metal foils to be formed precisely and with high material throughputs [1]. For instance, Lithium-ion battery performances are influenced by the cut quality of the electrode, which is directly related to the stability of the battery cell over time. Currently, mechanical shaping such as die cutting, and rotary knife slitting have been used respectively, which require expensive tooling [2].
A comparison is carried out between the processing results employing the interference pattern and single gaussian beam, shown in Figure 1a. While the single gaussian beam process is not sufficient for cutting a 10 µm thin metallic foil, the interference setup depicts an improvement of over 100 %. This contribution shows how an interference pattern can improve the performance of a remote laser cutting process of pure copper foils by increasing the cutting process effectiveness for low power laser sources. The proof of concept is performed by using a nanosecond laser source with a wavelength λ of 527 nm and a pulse duration of 5 ns. This laser source is equipped with a two-beam scanning interference setup, leading to a spatial period of 12.5 µm. In the experiments, processing parameters such as laser power, scanning speed and pulse-to-pulse distance are varied. The foil breakthrough and their effect on the generated material modifications are investigated. The results reveal that only small spatter formations are detected, with average particle sizes of 1.75 ± 0.82 µm on the top side of the foil, shown in Figure 1 b, c. Moreover, only small spatter formations of less than 1 µm were determined at the bottom side of a fully separated copper foil [3].