Fig. 1. Schematic of femtosecond laser drilling device

Fig. 2. Results of trepanning with different parameters. (a) Entrance diameter; (b) depth of blind hole

Fig. 3. Tapers of the wall with different trepanning parameters

Fig. 4. Machining results of hole drilled by femtosecond laser with focal length of 1000 mm. (a) Entrance; (b) cross section; (c) cross section of entrance, no spatter and recast layer found; (d) interface between ceramic and bonding layer, interface between bonding layer and metal, no crack extending found

Fig. 5. Entrance holes under single layer trepanning with a low speed and different trepanning times. (a) 3 times; (b) 5 times; (c) 6 times; (d) 7 times

Fig. 6. (a)(b)(c) SEM micrographs of particles collected during processing; (d) EDS of particles and Ag base of the chosen area