Microwelding of glass to silicon by green ultrafast laser pulses. (December 2019)

• Record Type: Journal Article
• Authors: Zhang, Jiejuan; Xu, Sizhi; Dong, Yukun; Zhang, Congzheng; Li, Jiaming; Guo, Liang; Zhang, Qingmao
• Is Part Of: Optics & laser technology. Volume 120(2019)
• Publication Date: 2019-12
• Subjects: Microwelding -- Ultrafast laser -- Glass -- Silicon; Optics -- Periodicals; Lasers -- Periodicals; Electronic journals; 621.366
• DOI: 10.1016/j.optlastec.2019.105720
• Languages: English
• ISSNs: 0030-3992

Abstract

Highlights: Direct microwelding of glass to silicon by 515 nm picosecond laser was successfully implemented. New crystalline phases (SiO2 ) were detected in the laser intermediate area. Elements have a spatial distribution gradient within the cross section of welding lines. Morphology and width of welds change with laser intensity and energy density distribution. Abstract: In the present work, a direct bond between glass and silicon with optical contact was formed by 515 nm picosecond laser controlled by the galvanometer scanning system. A crack-free welding effect without edge breakage and residues was obtained with breaking strength as high as 122 MPa. New crystalline phase (SiO2 ) was produced and silicon and oxygen have a spatial distribution gradient in the welding area analyzed by XRD and EDS, respectively, revealing that mixing and inter-diffusion of substances have occurred during laser irradiation. The transmission of near infrared light in the welding area is significantly increased compared with the non-welding area analyzed by inverted microscope. A confocal laser scanning microscope was used to observe the morphology and width of welds, which variation trend of axial focal positions is consistent with the teardrop structure produced by nonlinear absorption effect. Scanning speeds and laser repetition frequencies also affect the width and morphology of the weld.