Laser direct ablation with picosecond laser pulses at high pulse repetition frequencies

摘要

Laser direct ablation (LDA) produces patterns cut into a dielectric layer for the formation of electrically conductive traces with controlled signal propagation characteristics. LDA processing includes selecting a dose fluence for removing a desired depth of material along a scribe line on a surface of a workpiece, selecting a temporal pulsewidth for each laser pulse in a series of laser pulses, and selecting a pulse repetition frequency for the series of laser pulse. The pulse repetition frequency is based at least in part on the selected temporal pulsewidth to maintain the selected dose fluence along the scribe line. The selected pulse repetition frequency provides a predetermined minimum overlap of laser spots along the scribe line. The LDA process further includes generating a laser beam including the series of laser pulses according to the selected dose fluence, temporal pulsewidth, and pulse repetition frequency.