Singulation of layered materials using selectively variable laser output

• US 9,120,181 B2
• Filed: 09/16/2011
• Issued: 09/01/2015
• Est. Priority Date: 09/16/2010
• Status: Expired due to Fees

• Current Assignee: Rayd LLC
• Original Assignee: Coherent Inc (Coherent Corp.)
• Inventors: Srinivas, Ramanujapuram A., Greenberg, Michael, Gaudiosi, David, Mielke, Michael, Booth, Tim
• Primary Examiner(s): Evans, Geoffrey S
• Application Number:
  US13/234,795
• Publication Number:
  US 20120152915A1
• Time in Patent Office: 1,446 Days
• Field of Search: 219/121.67, 219/121.72, 219/121.73, 219/121.74, 219/121.76, 219/121.77
• US Class Current: 1/1
• CPC Class Codes: B23K 2103/172 wherein at least one of the layers is non-metallic
• CPC Class Codes: B23K 26/36 Removing material B23K26/55, B23K26/57 take precedence
• CPC Class Codes: B23K 26/40 taking account of the properties of the material involved

Abstract

Systems and methods for processing, selectively ablating, and singulating layered materials. According to some embodiments, methods for selectively ablating a layered material may include selectively varying a wavelength of at least a portion of a primary ultrafast laser beam to create a secondary ultrafast laser beam with a second wavelength, the primary ultrafast laser beam being configured to ablate a layer of the layered material, the secondary ultrafast laser beam being configured to ablate an additional layer of the layered material and applying the first and second ultrafast laser beams to the layered material to create a singulated product.

Claims

1. A method for selectively ablating a layered material, the method comprising:

selectively varying a wavelength of at least a portion of a primary ultrafast laser beam to create a secondary ultrafast laser beam with a second wavelength, the primary ultrafast laser beam being configured to ablate a layer of the layered material, the secondary ultrafast laser beam being configured to ablate an additional layer of the layered material; and

applying the primary and secondary ultrafast laser beams to the layered material to create a singulated product, wherein the secondary ultrafast laser beam ablates a getter layer of the layered material and the primary ultrafast laser beam ablates a device layer of the layered material.

2. The method according to claim 1, wherein the singulated product includes one or more ablated features.

3. The method according to claim 1, wherein the getter layer includes a polymer and the secondary ultrafast laser beam includes a wavelength that includes any of green, blue, or ultraviolet.

4. The method according to claim 1, wherein a wavelength of the primary ultrafast laser beam is substantially 1552 nanometers.

5. The method according to claim 1, further comprising modulating the wavelength of a portion of the primary ultrafast laser beam to generate the one or more secondary ultrafast laser beams, wherein the wavelength of each of the one or more secondary ultrafast laser beams is a harmonic of the wavelength of the primary ultrafast laser beam.

6. The method according to claim 1, wherein selectively varying includes:

diverting at least a portion of the primary ultrafast laser beam into a secondary ultrafast laser beam; and

modulating the wavelength of the secondary ultrafast laser beam.

7. The method according to claim 1, wherein the secondary ultrafast laser beam is replaceable with a laser beam having a pulse duration that is selected from any of, a nanosecond wave, a picosecond wave, a femtosecond wave, or combinations thereof, wherein the frequency of the laser beam is selectively adjustable.

8. The method according to claim 1, wherein applying includes:

focusing the secondary ultrafast laser beam to a getter layer of the layered material;

traversing the secondary ultrafast laser beam along a tool path to ablate at least a portion of the getter layer; and

focusing the primary ultrafast laser beam to a device layer along at least a portion of the tool path to ablate at least a portion of the device layer.

9. The method according to claim 8, wherein focusing includes creating an intensity profile for at least one of the secondary ultrafast laser beam and the primary ultrafast laser beam, the intensity profile including any of top-hat, Bessel, parabolic, super-Gaussian, irregular, and polygonal.

10. A system for selectively ablating layers of a layered material, the system comprising:

at least one laser emitting source for emitting two or more ultrafast laser beams; and

a beam delivery assembly for delivering the two or more ultrafast laser beams to the layered material, the beam delivery assembly comprising;

an optical subassembly for selectively varying a focal point of each of the two or more laser beams in such a way that each of the two or more ultrafast laser beams ablate different layers of the layered material, wherein the two or more ultrafast laser beams have different harmonic wavelengths relative to one another, wherein a first one of the two or more ultrafast laser beam ablates a device layer of the layered material and a second one of the two or more the primary ultrafast laser beam ablates a getter layer of the layered material.

11. The system according to claim 10, wherein the beam delivery assembly further comprises a harmonic converter that converts the wavelength of an ultrafast laser beam from a fundamental wavelength to a harmonic wavelength thereof.

12. The system according to claim 10, wherein the at least one laser emitting source includes two or more laser emitting sources, each of the two or more laser emitting sources generating a laser beam having a particular wavelength.

13. The system according to claim 12, wherein a first laser beam of a first laser emitting source includes a first wavelength and wherein a second laser beam of a second laser emitting device includes a wavelength that is a harmonic of the first wavelength.

14. The system according to claim 10, wherein the optical sub assembly comprises a dichroic combiner that aligns two or more ultrafast laser beams into substantially collinear laser beams.

15. The system according to claim 14, wherein the optical sub assembly further comprises a dove prism that receives the substantially collinear laser beams from the dichroic combiner, wherein the dove prism is rotatable about a central axis to change an alignment direction of the substantially collinear laser beams.

16. The system according to claim 14, wherein the optical sub assembly further comprises a plurality of mirrors that are arranged in such a way that the plurality of mirrors approximates optical behavior of a dove prism when the substantially collinear laser beams are directed into the plurality of mirrors.

17. The system according to claim 14, wherein the optical sub assembly further comprises beam shaping optics that selectively adjust an intensity profile of at least one of the substantially collinear laser beams.

18. The system according to claim 17, wherein the intensity profile includes any of top-hat, Bessel, parabolic, super-Gaussian, irregular, and polygonal.

19. A system for singulating a layered material, the system comprising:

a laser emitting source for emitting a primary laser beam having a fundamental wavelength;

a beam splitter for diverting a portion of the laser beam into a harmonic converter that converts the portion of the laser beam into a secondary laser beam, the secondary laser beam having a wavelength that is a harmonic of the fundamental wavelength; and

a laser combiner that receives the primary laser beam and the secondary laser beam and aligns the primary laser beam and the secondary laser beam in a substantially collinear relationship to one another, wherein the secondary laser beam ablates a getter layer of the layered material and the primary laser beam ablates a device layer of the layered material.

20. The system according to claim 19, further comprising an optical alignment member that receives the primary laser beam and the secondary laser beam from the laser combiner, the optical alignment member being rotatable about a central axis to transpose the substantially collinear relationship of the primary laser beam and the secondary laser beam.