Laser beam boring device e.g. for boring blind holes in multi layer circuit boards, uses frequency-sensitive plasma radiation detector for detecting radiation intensity during boring of holes

摘要

A device for laser beam boring of blind holes using a pulsed laser beam source (3) and a beam guiding device (4). A signal evaluating device (27) is used for detecting and analyzing the incidence process signal, and a further frequency-sensitive plasma radiation detector is provided for detecting the radiation intensity of the plasma generated insulating material removed during drilling of the boring. A laser detector (11) detects the respective pulse intensity of each pulse from the laser beam source, and the signals of the radiation intensity of the two plasma radiation detectors (14,15) can be normed with the signal of the laser detector (11), and both normed signals are simultaneously evaluated to distinguish between insulating- and metal-material (22,21).