Crack free laser ducting of glass in the microelectronics industry
Résumé
This paper investigates laser dicing of glass (commercial Borofloat®33) for backend packaging in the microelectronics industry. An ultraviolet (355 nm) diode-pumped solid-state nanosecond laser was used in this investigation. Laser processing of glass is challenging as glass is transparent for most available wavelengths. Nonlinear absorption can be obtained but produces undesirable effects (chipping, cracks) in the nanosecond regime. In the present study, an absorptive polymer layer was spin coated on top of the substrate and acts as a heat incubator during laser irradiation. This paper shows that preheating the substrate produces clean scribe. Laser dicing is qualitatively and quantitatively more efficient than blade sawing. 1 × 1 mm2 dice have been separated by laser scribe/break method that allows a throughput increase of 18%versus blade sawing. © 2013 Laser Institute of America