Controlled process for polymer micromachining using designed pulse trains of a UV solid state laser

Laser processing of medical devices

“…Pulsed CO 2 lasers can lack the pulse length or peak power when drilling metals, although high average power pulsed CO 2 lasers can have high production rates for single-pulse 'on-the-fly' drilling (Olsen and Alting, 1995). Frequency tripling and quadrupling into the UV allow these lasers to process polymers and other materials transparent to NIR and visible laser radiation (Ilie et al, 2007). This has become widely employed in the food packaging industry for atmosphere control packaging and to control package opening.…”

Laser microvia formation in polyimide thin films for metallization applications

“…Polyimide is also used for its good mechanical strength, high thermal properties, and resistance to abrasive chemicals. Most research papers have concentrated their research on the Dupont™ brand of polyimide films (Srinivasan, 1993; Luk'yanchuk et al , 1997; Ilie et al , 2005, 2007; Mullan et al , 2005, 2007; Himmelbauer et al , 1996; Küper et al , 1993; Metayer et al , 2001; Bäuerle et al , 1997; Pervolaraki et al , 2004; Li et al , 2004; Hauer et al , 2003; Shin et al , 2006). There are many suppliers of polyimide film within the FPCB industry, but there are no comparison studies indicating how the various properties of these films can be used for microvia drilling.…”

“…As with the lack of comparative research studies on variations of polyimide film from different manufacturers, research on the types of lasers used for processing has also been limited. Laser choices for research have primarily been excimer and Nd:YAG, and research has focused more on using excimer lasers in the 193 to 351 nm wavelength ranges (Kawamura et al , 1982; Srinivasan and Mayne‐Banton, 1982; Srinivasan, 1993; Pan et al , 2007; Lippert and Dickinson, 2003; Luk'yanchuk et al , 1997; Himmelbauer et al , 1996; Küper et al , 1993; Ilie et al , 2007; Metayer et al , 2001; Bäuerle et al , 1997; Gu et al , 2002; Zweig and Deutsch, 1992; Hauer et al , 2003; Lippert et al , 2003; Shin et al , 2006; Kordás et al , 2001). Excimer lasers' broad range of UV wavelengths, small features sizes, and variable pulse widths have made them useful research tools.…”

“…Dimensions of microvias when laser percussion drilled has been researched extensively (Ilie et al , 2005, 2007; Mullan et al , 2005, 2007; Shin et al , 2007; Gu et al , 2002). Many research studies use excimer lasers as noted above, but most FPCB manufacturers use Nd:YAG lasers operating at 355 nm.…”

“…Top diameter measurements have been shown to increase significantly as fluence increases, and studies have revealed a 75 per cent increase in the diameter at 15 J cm −2 , 125 per cent increase at 30 J cm −2 , and 150 per cent increase at 37 J cm −2 (Ilie et al , 2005; Mullan et al , 2005). Research is mainly focused on 266 and 355 nm wavelengths with short pulse widths and high fluence (Ilie et al , 2005, 2007; Pervolaraki et al , 2004; Mullan et al , 2005). As with the top diameter, the bottom (i.e.…”