A new drilling technique is proposed for removing polymeric layer formed on conductive layer using IR laser light, which is absorbed not sufficiently for ablation by the polymeric layer. In this technique, a piece of polymeric film was blown off after a single shot of irradiation. To apply this technique to laser drilling processes, we have systematically measured sizes of the resulting holes, varying the fluence, the irradiation area and the thickness of a polymeric layer. We also investigated the physical aspects of this phenomenon with spectroscopic measurement of the luminescence from the samples. We observed sharp peaks in the spectrum in the case of laser beam fluence of 8.6 J/cm{sup}2 while such intense peaks could not be seen when the fluence decreased to 1.2 J/cm{sup}2. Thus, the polymeric film was removed without violent decomposition into atomic species. Advantages of this technique are (1) the polymeric layer can be completely removed within a certain area by a single shot of laser pulse, and (2) it is possible to escape from problems such as debris, smear and delamination, which occurs when CO{sub}2 laser or UV laser is used.
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