| dc.description.abstract | Due to its stable physical and chemical properties, glass is widely used in different fields such as biomedicine, aerospace, microelectronics, and semiconductors. The problem of glass bonding is encountered in various fields, particularly for packaging in electronics, optronics, and semiconductors. In the literature, there have been several methods reported for glass-to-glass welding, however, most of them are difficult to simultaneously provide the precision, weld quality, and production speed required for high efficiency and high economic benefits. Recently, with the advancement of laser technology, it has become easier to achieve localized welding of glass with pulsed lasers. In addition, the nonlinear absorption mechanism of an ultrafast pulsed laser by the glass can also be used to realize laser transmission welding at the interface of two pieces of glass.
In the pulsed laser processing system, its optical path arrangement can be divided into a short-focus objective lens system and a long-focus galvanometer system. The former focuses the laser light on a smaller spot, and the relative movement of the light and the material can only rely on the movement of an X-Y table, which cannot effectively improve the welding efficiency. For the latter, the incoming laser light is aligned through two reflectors agitated by two piezo plates and focusing through an f-theta lens. Consequently, patterning welding can be effectively achieved. In this study, the galvanometer system is used to weld the glass and glass without us-ing any fixtures. Compared with the short-focus objective lens system, although the welding range of raw materials is larger, the welding speed can be effectively improved. This study also tests different process parameter sets and finds out the relative best set through strength tests of the welds. Results show that the highest shear stress could achieve was 80.52 MPa when the processing laser power was 9 W and the scanning line space was 25 μm. The highest available tensile stress was 11.29 MPa at the power of 7 W and the scanning line space of 25 μm. Through the observation of the cross-section of the weld spot, it was found that the damage to the shear stress was caused by the crack between the two glass pieces, while the separation by tensile stress occurred between the lower edge of the molten and the lower glass. This study al-so usds a high-speed camera to observe the evolution of the weld during the bonding and, com-bined with reports in the literature, provided a complete description of the glass-to-glass laser bonding process. | en_US |