Abstract

Industries in the precision machinery, electrical, and healthcare sectors require the development of improved micro-joining/welding techniques [1]. Direct joining techniques of glass with a focused ultra-short (femtosecond) pulsed laser beam have recently been reported [2-4]. In these studies, by focusing the ultra-short laser pulses at the interface between the glass substrates, the nonlinear absorption of the beam has been exploited and glass joint strength of 14.9 MPa was reported [4]. However, there are a number of shortcomings associated with this technique. The process requires a lens objective of high numerical aperture, typically in the range of 0.4 – 0.65. This leads to a poor working distance and welding depth, and ultimately restricts the welding efficiency and the processing speed. It also imposes strict requirements on the surface quality of the work pieces - currently within λ/4. The above constitutes a serious challenge for widespread adoption of this technique by industry.

© 2015 IEEE