Single-Crystal Laser Separation Using Internal Modification and Notches

The patent applies preliminary action by using a first laser beam to pre-modify the inner portion of the single crystal material before separation. This creates a modification layer that weakens the material structure in advance, enabling subsequent easy separation without mechanical cutting. The modification layer is formed at the desired separation location, so when separation occurs, material loss is minimized because the break happens precisely at the modified zone rather than requiring wide kerf for mechanical cutting.

The patent replaces the mechanical diamond wire cutting system with a laser-based modification and separation system. Instead of using mechanical abrasion that causes significant kerf loss, the invention uses laser energy to modify the material's internal structure and then separates it by destroying the modification layer. This substitution of mechanical cutting with laser-based processing dramatically reduces material loss while achieving clean separation.

The patent applies segmentation by creating a distinct modification layer within the single crystal material that is spatially separated from the unaffected outer regions. This modification layer has different properties (reduced bonding strength) compared to the original material. By forming this intermediate layer at a specific depth, the patent enables selective separation - the material can be easily split at the modification layer while the outer surfaces remain intact and undamaged.

The modification layer acts as an intermediary zone between the laser energy input and the final separation outcome. This intermediate layer, created by laser modification, serves as a predetermined weak plane that facilitates controlled separation. The water column and second laser beam further process this intermediary layer by forming notches and destroying it, making the separation process reliable and controllable rather than random or difficult.