OPTICAL DEVICE SHAPING

• US 20090275157A1
• Filed: 06/26/2009
• Published: 11/05/2009
• Est. Priority Date: 10/02/2006
• Status: Abandoned Application

• Current Assignee: illumitex, Inc.
• Original Assignee: illumitex, Inc.
• Inventors: Winberg, Paul N., Duong, Dung T., Thomas, Matthew R., Pickering, Elliot M.
• Application Number:
  US12/492,599
• Publication Number:
  US 20090275157A1
• Time in Patent Office: Days
• US Class Current: 438/29
• CPC Class Codes: G02B 19/0023 at least one surface having optical power
• CPC Class Codes: G02B 19/0028 refractive and reflective surfaces, e.g. non-imaging catadioptric systems
• CPC Class Codes: G02B 19/0061 the light source comprising a LED semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission H01L33/00
• CPC Class Codes: H01L 33/0095 Post-treatment of devices, e.g. annealing, recrystallisation or short-circuit elimination
• CPC Class Codes: H01L 33/10 with a light reflecting structure, e.g. semiconductor Bragg reflector
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating

Abstract

Embodiments described herein provide methods for manufacturing an optical device having shaped sidewalls. A desired substrate shape corresponding to an LED or other optical device can be determined. The optical device can have a substrate comprising an exit face and sidewalls positioned and shaped to reflect light to the exit face to allow light to escape the exit face. A substrate material can be shaped based on the desired substrate shape for one or more LEDs. Shaping can be done using a wire saw, etching, ultrasonic shaping or other technique.

Claims

1. A method of manufacturing an optical device comprising:

providing a desired substrate shape for an optical device having a shaped substrate portion comprising;

an interface to a non-substrate layer adapted to receive light generated in a light emitting region of the optical device;

an exit face that has at least 70% of a minimum area necessary to conserve radiance for a desired half-angle of light projected from the LED, wherein the exit face is a select distance from the interface;

a set of sidewalls, each sidewall positioned and shaped to cause at least a majority of rays having a straight transmission path from the interface to that sidewall to reflect to the exit face with an angle of incidence at the exit face at less than or equal to a critical angle at the exit face;

shaping a substrate material based on the desired substrate shape to form shaped substrate portions of one or more optical devices.

2. The method of claim 1, wherein shaping the substrate material comprises:

providing an abrasive slurry;

vibrating a tool at ultrasonic frequency to cause the abrasive slurry to ablate the substrate material in multiple rows.

3. The method of claim 1, wherein shaping the substrate material comprises:

directing a laser to the substrate material using a water column;

ablating material from the substrate material using the laser.

4. The method of claim 1, wherein shaping the substrate material further comprises ablating the substrate material using a particle jet.

5. The method of claim 1, further comprising:

mounting a wafer in a tool, wherein the wafer comprises the substrate material; and

protecting portions of the wafer to prevent damage to those portions during shaping.

6. The method of claim 1, further comprising mounting a wafer to a support structure, wherein the wafer comprises the substrate material.

7. The method of claim 6, wherein shaping the substrate material further comprises removing a portion of the support structure.

8. The method of claim 1, wherein shaping the substrate material further comprises leaving a web a material between shaped substrate portions for LEDs.

9. The method of claim 1, wherein shaping the substrate further comprises shaping the substrate using a wire saw.

10. The method of claim 1, wherein shaping the substrate further comprises cutting the substrate at select angles to form a sidewall using one or more straight grinding wheels.

11. The method of claim 10, wherein cutting the substrate at select angles to form a sidewall comprises cutting the substrate at three or more select angles.

12. The method of claim 11, wherein cutting the substrate at select angles to form the sidewall comprises cutting the substrate at eight or less select angles.

13. The method of claim 1, wherein shaping the substrate further comprises cutting the substrate at select angles to form a sidewall using three or more grinding wheels wherein each of the three or more grinding wheels are shaped with an angled section selected to cut the substrate at a desired angle.

14. The method of claim 1, wherein the exit face has minimum area necessary to conserve radiance and the distance is a minimum distance so that all rays with a straight transmission path from the interface to the exit face will be incident on the exit face at less than the critical angle at the exit face.

15. A method of shaping an LED comprising:

providing a wafer comprising a substrate material and one or more layers for a quantum well region of the LED;

determining a desired substrate shape corresponding to an LED comprising;

an exit face opposite from and a distance from an interface to a non-substrate layer adapted to receive light generated in a light emitting region of the LED, the exit face having at least 70% of a minimum area necessary to conserve radiance for a desired half-angle of light projected from the shaped substrate; and

a set of sidewalls, wherein each sidewall is positioned and shaped so that at least a majority of rays having a straight transmission path from the interface to that sidewall reflect to the exit face with an angle of incidence at the exit face of less than or equal to a critical angle at the exit face; and

mounting the wafer to a support structure;

cutting the substrate material to form a shaped substrate portion of the LED based on the desired substrate shape.

16. The method of claim 15, wherein cutting the substrate comprises cutting the substrate with a wire saw.

17. The method of claim 15, wherein cutting the substrate comprises cutting the substrate at select angles to form a sidewall using one or more straight grinding wheels.

18. The method of claim 17, wherein cutting the substrate at select angles to form a sidewall comprises cutting the substrate at three or more select angles.

19. The method of claim 18, wherein cutting the substrate at select angles to form the sidewall comprises cutting the substrate at eight or less select angles.

20. The method of claim 15, wherein the exit face has minimum area necessary to conserve radiance.

21. The method of claim 15 wherein shaping the substrate further comprises cutting the substrate at select angles to form a sidewall using three or more grinding wheels wherein each of the three or more grinding wheels are shaped with an angled section selected to cut the substrate at a desired angle.