Fig. 1. Schematic of laser processing optical path

Fig. 2. Schematic of stealth dicing

Fig. 3. Flow chart of laser stealth dicing. (a) Prefabricating ablation channel on bottom surface; (b) modified layers formed inside;(c) multi-modifying along step direction; (d) splitting along modified surface

Fig. 4. Schematics of internal pulse pick. (a) Pulse sequence of seed source; (b) TTL level signal; (c) picked pulses

Fig. 5. Schematics of multi-pulse mode and burst mode pulse. (a) single pulse; (b) two sub-pulses; (c) n sub-pulses

Fig. 6. Influence of pulse energy on cutting effect under multi-pulse mode. (a1)-(a4) Morphologies of top surface ; (b1)-(b4) morphologies of bottom surface ; (c1)-(c3) edge chipping morphologies of top surface; (d1)-(d3) edge chipping morphologies of bottom surface; (e1)-(e3) cross-section morphologies; (f) influence of single pulse energy on kerf width; (g) influence of single pulse energy on top and bottom edge chipping sizes and cross-section roughness

Fig. 7. Influence of feed distance on cutting effect under multi-pulse mode. (a1)-(a3) Morphologies of top surface; (b1)-(b3) morphologies of bottom surface; (c1)-(c3) edge chipping morphologies of top surface; (d1)-(d3) edge chipping morphologies of bottom surface; (e1)-(e3) cross-section morphologies; (f) influence of feed distance on kerf width; (g) influence of feed distance on top and bottom edge chipping sizes and cross-section roughness

Fig. 8. Influence of repetition frequency on cutting effect under multi-pulse mode. (a1)-(a4) Morphologies of top surface; (b1)-(b4) morphologies of bottom surface; (c1)-(c4) edge chipping morphologies of top surface; (d1)-(d4) edge chipping morphologies of bottom surface; (e1)-(e4) cross-section morphologies; (f) influence of repetition frequency on kerf width; (g) influence of repetition frequency on top and bottom edge chipping sizes and cross-section roughness

Fig. 9. Influence of pulse width on cutting effect under multi-pulse mode. (a1)-(a3) Morphologies of top surface; (b1)-(b3) morphologies of bottom surface; (c1)-(c3) edge chipping morphologies of top surface; (d1)-(d3) edge chipping morphologies of bottom surface ; (e1)-(e3) cross-section morphologies; (f) influence of pulse width on kerf width; (g) influence of pulse width on top and bottom edge chipping sizes and cross-section roughness

Fig. 10. Influence of scanning speed on cutting effect under multi-pulse mode. (a1)-(a3) Morphologies of top surface; (b1)-(b3) morphologies of bottom surface; (c1)-(c3) edge chipping morphologies of top surface; (d1)-(d3) edge chipping morphologies of bottom surface; (e1)-(e3) cross-section morphologies; (f) influence of scanning speed on kerf width; (g) influence of scanning speed on top and bottom edge chipping sizes and cross-section roughness

Fig. 11. Influence of sub-pulse number on cutting effect under burst mode. (a1)-(a4) Morphologies of top surface; (b1)-(b4) morphologies of bottom surface; (c1)-(c4) edge chipping morphologies of top surface; (d1)-(d4) edge chipping morphologies of bottom surface; (e1)-(e4) cross-section morphologies; (f) influence of sub-pulse number on kerf width; (g) influence of sub-pulse number on top and bottom edge chipping sizes and cross-section roughness

Table 1. Main parameters of ultrafast laser

Table 2. Main parameters of objective lens

Table 3. Main parameters of movement platform