Ultraviolet emitting device with shaped encapsulant

• US 10,454,005 B1
• Filed: 08/22/2018
• Issued: 10/22/2019
• Est. Priority Date: 01/10/2017
• Status: Active Grant

• Current Assignee: Rayvio Corporation
• Original Assignee: Rayvio Corporation
• Inventors: Sudradjat, Faisal, Liu, Saijin, Collins, Douglas A.
• Primary Examiner(s): Bachner, Robert G
• Assistant Examiner(s): Reida, Molly K
• Application Number:
  US16/109,208
• Time in Patent Office: 426 Days
• CPC Class Codes: H01L 33/486 adapted for surface mounting
• CPC Class Codes: H01L 33/52 Encapsulations
• CPC Class Codes: H01L 33/54 having a particular shape
• CPC Class Codes: H01L 33/56 Materials, e.g. epoxy or silicone resin
• CPC Class Codes: H01L 33/60 Reflective elements

Abstract

Embodiments of the invention include a light emitting diode (UVLED), the UVLED including a semiconductor structure with an active layer disposed between an n-type region and a p-type region. The active layer emits UV radiation. The UVLED is disposed on a mount. A transparent encapsulant is disposed over the UVLED. The transparent encapsulant has an angled sidewall.

Claims

1. A device comprising:

an ultra-violet light emitting diode (UVLED) comprising a semiconductor structure comprising an active layer disposed between an n-type region and a p-type region, wherein the active layer emits UV radiation;

a mount, wherein the UVLED is disposed on a top surface of the mount; and

an encapsulant disposed over the UVLED, the encapsulant having a top surface and substantially flat sidewalls that have a roughened surface, the roughened surface comprising grooves in the sidewalls substantially perpendicular to the top surface of the mount.

2. The device of claim 1 wherein the roughened surface comprises a corrugated surface.

3. The device of claim 1 wherein the roughened surface comprises ripples.

4. The device of claim 1 wherein the sidewalls are sloped.

5. The device of claim 4 wherein the sidewalls slope outward from the top surface of the mount to the top surface of the encapsulant.

6. The device of claim 4 wherein the sidewalls slope inward from the top surface of the encapsulant to the top surface of the mount.

7. The device of claim 1 wherein the top surface of the encapsulant is also a roughened surface.

8. The device of claim 1 wherein the roughened surface comprises the grooves directly formed in the sidewalls of the encapsulant by removing portions of the encapsulant.

9. The device of claim 1 wherein an index of refraction of the encapsulant varies across a thickness of the encapsulant.

10. The device of claim 1 wherein the encapsulant has a square shape.

11. The device of claim 10 further comprising a trench formed in a top surface of the encapsulant, the trench having a square shape that surrounds the UVLED.

12. The device of claim 10 further comprising a trench formed in a top surface of the encapsulant, the trench having a cross shape.

13. The device of claim 1 wherein the encapsulant comprises a transparent material mixed with one of bubbles and beads.

14. The device of claim 1 wherein a plurality of holes are formed in the encapsulant.

15. The device of claim 1 wherein the encapsulant is pre-formed then mounted over the UVLED.

16. The device of claim 1 wherein the encapsulant is deposited as a liquid or semi-solid over the UVLED and shaped.

17. The device of claim 1 wherein the sidewalls are sloped at a constant angle.