Laser processing of sapphire substrate and related applications
A method of laser processing a material to form a separated part. The method includes focusing a pulsed laser beam into a laser beam focal line, viewed along the beam propagation direction, directed into the material, the laser beam focal line generating an induced absorption within the material, the induced absorption producing a hole or fault line along the laser beam focal line within the material, and directing a defocused carbon dioxide (CO 2 ) laser from a distal edge of the material over the plurality of holes to a proximal edge of the material.
1. An article comprising sapphire, the article including an edge having a series of defect lines where each defect line extends at least 250 μm, the defect lines are less than 5 μm in diameter, the edge has a surface roughness Ra <0.5 μm, and the subsurface damage of the edge is <100 μm.
2. The article of claim 1 , wherein the subsurface damage of the edge is <75 μm.
3. The article of claim 1 , wherein the defect lines extend through the full thickness of the article.
4. The article of claim 1 , wherein a distance between the defect lines is greater than 0.5 μm and less than or equal to about 15 μm.
5. The article of claim 1 , wherein the article is less than 1.5 mm thick.
6. The article of claim 5 , wherein the article is a circular disk.
7. The article of claim 1 , wherein the article comprises a glass substrate with a sapphire layer attached thereto.
8. The article of claim 7 , wherein the glass substrate is from 100 microns to 1 mm thick, and the sapphire layer is from 1 micron to 600 microns thick.