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. A method of laser cutting a material comprising:
focusing a pulsed laser beam into a laser beam focal line, the laser beam focal line having a length in a range between about 0.1 mm and 100 mm;
directing the laser beam focal line into the material, the laser beam focal line generating an induced absorption within the material, the induced absorption producing a defect line along the laser beam focal line within the material;
translating the material or the laser beam relative to one another, thereby forming a plurality of defect lines in the material with the laser; and
directing an IR laser beam over the plurality of defect lines.
2. The method of claim 1 , wherein the material is sapphire.
3. The method of claim 1 , wherein a pulse duration of the pulsed laser beam is in a range of between greater than about 1 picosecond and less than about 100 picoseconds.
4. The method of claim 3 , wherein the pulse duration of the pulsed laser beam is in a range of between greater than about 5 picoseconds and less than about 20 picoseconds.
5. The method of claim 1 , wherein a repetition rate of the pulsed laser beam is in a range of between 1 kHz and 2 MHz.
6. The method of claim 5 , wherein the repetition rate of the pulsed laser beam is in a range of between 10 kHz and 650 kHz.
7. The method of claim 1 , wherein the pulsed laser beam has an average laser power measured at the material greater than 40μJ per mm thickness of material.
8. The method of claim 1 , wherein the pulses are produced in bursts of at least two pulses separated by a duration in a range of between 1 nsec and 50 nsec, and the burst repetition frequency is in a range of between about 1 kHz and about 2000 kHz.
9. The method of claim 8 , wherein the pulses are separated by a duration in a range of between 10 nsec and 30 nsec.
10. The method of claim 1 , wherein the pulsed laser beam has a wavelength and the material is substantially transparent at the wavelength.
11. The method of claim 1 , wherein the laser beam focal line has a length in a range of between about 0.1 mm and about 10 mm.
12. The method of claim 1 , wherein the laser beam focal line has an average spot diameter in a range of between about 0.1 μm and about 5 μm.
13. The method of claim 1 , further comprising directing the IR laser from a proximal edge of the material to a tangential edge of the part, thereby separating a part from the material.
14. The method of claim 1 , wherein directing the IR laser beam comprises directing a CO 2 laser beam.
15. The method of claim 1 , wherein the IR laser beam is defocused to a spot size in a range of between about 2 mm and about 20 mm.
16. The method of claim 1 , wherein directing the IR laser beam includes directing the IR laser beam from a distal edge of the material to a proximal edge of the material.
17. A method of laser cutting a material comprising:
(i) focusing a pulsed laser beam into a laser beam focal line, the laser beam focal line having a length in a range between about 0.1 mm and 100 mm;
ii) directing the laser beam focal line into the material, the laser beam focal line generating an induced absorption within the material, the induced absorption producing a defect line along the laser beam focal line within the material;
(iii) repeatedly performing (i) and (ii) to form a fault line within the material, the fault line including a plurality of the defect lines; and
(iv) directing an IR laser beam over the fault line.
18. The method of claim 17 , wherein the fault line is curved.
19. The method of claim 17 , wherein the fault line is circular.
20. The method of claim 17 , wherein the fault line is linear.
21. The method of claim 17 , wherein the directing the IR laser beam fractures the material along the fault line.
22. The method of claim 1 , wherein the pulsed laser beam is non-diffractive.
23. The method of claim 22 , wherein the pulsed laser beam is a Bessel beam, an Airy beam, a Weber beams or a Mathieu beam.
24. The method of claim 1 , wherein the pulsed laser beam is donut-shaped.
25. The method of claim 1 , wherein the focusing a pulsed laser beam comprises passing the pulsed laser beam through an axicon.
26. The method of claim 17 , wherein the pulsed laser beam is non-diffractive.
27. The method of claim 26 , wherein the pulsed laser beam is a Bessel beam, an Airy beam, a Weber beams or a Mathieu beam.
28. The method of claim 17 , wherein the pulsed laser beam is donut-shaped.
29. The method of claim 17 , wherein the focusing a pulsed laser beam comprises passing the pulsed laser beam through an axicon.