Online monitoring of laser micromachining using laser confocal scanning feedback

As a non-contact machining technology, depth control in laser micromachining is inherently more challenging than in conventional mechanical methods. Fluctuations in processing parameters or sample surface quality can easily lead to uneven machining depths. To overcome this challenge, this study designed a novel, to the best of our knowledge, laser micromachining system integrating a laser confocal scanning feedback system. Following each laser micromachining step, the laser confocal scanning feedback system characterized the surface material distribution or surface depth profile via intermittent in situ scanning, providing feedback for subsequent processing. This system was applied to fabricate flexible circuits and blind-hole arrays, demonstrating high precision in process control.