PHOSPHOR-CONVERTED LIGHT EMITTING DIODE DEVICE

• US 20110062468A1
• Filed: 09/11/2009
• Published: 03/17/2011
• Est. Priority Date: 09/11/2009
• Status: Abandoned Application

• Current Assignee: Koninklijke Philips N.V.
• Original Assignee: Philips Lumileds Lighting Company LLC (Apollo Global Management, Inc.), Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: BUTTERWORTH, Mark M.
• Application Number:
  US12/558,078
• Publication Number:
  US 20110062468A1
• Time in Patent Office: Days
• US Class Current: 257/98
• CPC Class Codes: H01L 33/508 having a non-uniform spatial arrangement or non-uniform concentration, e.g. patterned wavelength conversion layer, wavelength conversion layer with a concentration gradient of the wavelength conversion material
• CPC Class Codes: H01L 33/54 having a particular shape

Abstract

A light emitting diode is provided which is capable of emitting a first light having a first peak wavelength. The light emitting diode is provided with a phosphor layer overlying the light emitting diode and capable of absorbing the first light and emitting a second light having a second peak wavelength. The phosphor layer includes a pattern of holes positioned to allow the first peak wavelength to exit through the holes without being absorbed by the phosphor layer, and wherein the holes are placed to facilitate more of the first peak wavelength to exit the phosphor in the area of the holes than the second peak wavelength.

Claims

1. A device comprising:

a light emitting diode capable of emitting at least one first light having a first peak wavelength;

a phosphor layer overlying the light emitting diode and capable of absorbing the first light and emitting at least one second light having a second peak wavelength; and

wherein the phosphor layer includes a pattern of holes positioned to allow the first peak wavelength to exit through the holes without being absorbed by the phosphor layer, and

wherein the holes are placed to facilitate more of the first peak wavelength to exit the phosphor in the area of the holes than the second peak wavelength.

2. The device of claim 1 wherein the phosphor comprises phosphor powder bound in an epoxy.

3. The device of claim 1 wherein the phosphor comprises a phosphor powder combined with silicon in slurry.

4. The device of claim 1 wherein the phosphor includes phosphor particles statically coupled to the LED.

5. The device of claim 1, wherein the phosphor is a phosphor ceramic plate.

6. The device of claim 1, wherein the holes are generated using a laser.

7. The device of claim 1, wherein the holes are generated by drilling.

8. The device of claim 1, wherein the holes are generated during molding.

9. The device of claim 1, where the pattern includes more holes along the sides of the LED than in the center of the LED.

10. The device of claim 1, wherein the phosphor is thicker in the center of the LED and the pattern includes more holes in the center of the LED than along the sides of the LED.

11. The device of claim 1, wherein the holes include a diameter and the diameter is varied depending on the amount of first light desired in a particular area.

12. The device of claim 1, wherein the strategic placement of the holes is determined by the results of a spectrophotometer.

13. The device of claim 1, wherein the strategic placement of the holes is determined by the results of a colorimeter.

14. The device of claim 1, wherein the strategic placement of the holes is determined by a photo of the light output.

15. A device comprising:

a light emitting diode capable of emitting at least one first light having a first peak wavelength;

a phosphor layer overlying the light emitting diode and capable of absorbing the first light and emitting at least one second light having a second peak wavelength; and

wherein the phosphor layer includes a pattern of holes to allow the first light having the first peak wavelength to exit through the holes without being absorbed by the phosphor layer, and wherein the holes have a diameter and the diameter and placement of the holes are placed and sized to increase the amount of the first light having a first peak wavelength which exits the phosphor through the holes.

16. A method comprising:

analyzing the color of light emitted from a light emitting diode, which includes a phosphor which is capable of i) absorbing a first light from the light emitting diode having a first wavelength and ii) emitting at least one second light having a second peak wavelength;

calculating from the analyzing step the amount of first light and second light exiting the phosphor across at least a portion of the phosphor;

placing holes in the phosphor to increase the amount of the first light having a first wavelength which exits the phosphor by allowing the light to pass through the holes instead of being absorbed by the phosphor.

17. The method in accordance with claim 16, wherein the holes have varying diameters in dependence on the result of the calculation step.

18. The method in accordance with claim 16, wherein the step of analyzing includes using a spectrophotometer to measure the light output across the light emitting diode.

19. The method in accordance with claim 16, wherein the step of analyzing includes using a colorimeter to measure the x-y-z coordinates of the light across the light emitting diode.