Abstract:

This paper presents a focusing online drilling method of polygon mirror rotational scan a spherical lens to improve the production quality and reduce the production cost of laser drilling.The continuous beam emitted by CO2 laser is converged onto one of the upper surface of the polygon mirror via the optical modulator,and then the reflected light beams successively sweep into the focusing lens group.Since the linear distortion of focus spot,caused by off-axis aberration and the distortion of scanning speed,can lead to changes of the punch shape,aspheric focusing lens are used for beam shaping so that the shape of punch can be controlled by adjusting the shape of focus spot while focusing.The results show that the linearity error of scanning system can be controlled within 0.5%.This method improves the quality and efficiency of drilling compared with the conventional laser drilling methods.

Key words: laser technology;drilling;rotating polygon;focusing lens;beam shaping