To improve the capabilities of excimer laser ablation processing apparatus, we have been developing an innovative Multiple Irradiation Optical System (multiple irradiator). In this system, we placed a reflector opposite the mask, and used a mask with a highly reflective coating. The laser beams therefore irradiate the mask repeatedly, and we can use the laser energy more efficiently than conventional optical systems. The experimental results show that our system is 12 times more energy efficient than the conventional optical systems. Also, we have made a prototype excimer laser material processing apparatus with the multiple irradiator, which is suitable for drilling viaholes of less than 100 micrometers diameters such as viaholes of print circuit boards. The processing speed is less than 1 minute when the material is 100 mm X 100 mm wide and 25 micrometers thicknesses polyimide film, and the laser energy is 40 mJ/shot with 600 Hz frequency.

Date Published: 7 August 1993
PDF: 8 pages
Proc. SPIE 1869, Intracavity and Extracavity Control of Laser Beam Properties, (7 August 1993); doi: 10.1117/12.148395

Published in SPIE Proceedings Vol. 1869:
Intracavity and Extracavity Control of Laser Beam Properties
Roger Lee Facklam; Karl H. Guenther; Stephan P. Velsko, Editor(s)