石英玻璃与硅的飞秒激光微连接及其接头性能研究

Mechanical Properties of Microweld of Silica Glass to Silicon by Femtosecond Laser

飞秒激光的低热输入、极小热影响区的特点使其在微纳米尺度材料连接领域有明显的优势。为了将石英玻璃与硅可靠地连接在一起,使用功率为4~30 m W,频率为1 k Hz,波长为800 nm的飞秒激光对石英玻璃与硅进行连接,测试了接头的剪切强度,对接头横截面进行腐蚀处理,观察截面,分析了接头断裂前后的形貌特征,研究了激光参数,如激光功率、扫描速度、聚焦物镜的数值孔径以及离焦量对接头强度的影响规律。实验结果表明,根据焊接工艺的不同,接头强度分布在7~54 MPa之间。将激光准确定位到界面处,在合适的激光功率和扫描速度下可以降低焊缝缺陷,得到剪切强度较高的接头。

Femtosecond laser has distinct advantages in the field of micro/nano joining because of its unique properties, such as low heat input, nonlinear absorption and almost no heat affected zone. Silica glass and silicon are welded using 800 nm femtosecond laser with power of 4~30 m W and frequency of 1 k Hz. The shear strength and failure modes of the joints are investigated, the joint cross sections processed by etching are observed, and the fracture surface is also studied. The shear strength of the joints is in a range of 7~54 MPa,depending on the welding parameters. It is found that the laser power, scanning speed, numerical aperture and defocusing length have significant effect on the joint strength. The results indicate that focusing the laser on the interface can obtain high shear strength joints with appropriate laser power and scanning speed.