Light-emitting diode with light-conversion layer

• US 8,507,300 B2
• Filed: 12/24/2008
• Issued: 08/13/2013
• Est. Priority Date: 12/24/2008
• Status: Active Grant

• Current Assignee: Ledengin, Inc. (Ams-Osram AG)
• Original Assignee: Ledengin, Inc. (Ams-Osram AG)
• Inventors: Dong, Yi
• Primary Examiner(s): NGUYEN, THANH T
• Application Number:
  US12/344,158
• Publication Number:
  US 20100155755A1
• Time in Patent Office: 1,693 Days
• Field of Search: 438/29, 438/35, 257/E21.002, 257/E31.129
• US Class Current: 438/29
• CPC Class Codes: H01L 2933/0041 relating to wavelength conversion elements
• 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

Abstract

A method for making a lighting apparatus includes providing a substrate and disposing a light-emitting diode overlying the substrate. The light-emitting diode has a top surface oriented away from the substrate and a plurality of side surfaces. A light-conversion material is provided that includes a substantially transparent base material and a wave-shifting material dispersed in the base material. The concentration of the wave-shifting material can be at least 30%. In an embodiment, the concentration of the wave-shifting material can be approximately 50% or 70%. A predetermined amount of the light-conversion material is deposited on the top surface of the light-emitting diode while the side surfaces are maintained substantially free of the light-conversion material.

Claims

1. A method for making a lighting apparatus, the method comprising:

providing a substrate;

disposing at least a first light-emitting diode and a second light-emitting diode overlying the substrate, each of the first and the second light-emitting diodes having a top surface oriented away from the substrate and a plurality of side surfaces;

providing a first phosphor-containing material having a phosphor concentration of at least 30%

providing a second phosphor-containing material having a phosphor concentration of at least 30%;

depositing a first predetermined amount of the first phosphor-containing material on the top surface of the first light-emitting diode while maintaining the side surfaces substantially free of the phosphor-containing material; and

depositing a second predetermined amount of the second phosphor-containing material on the top surface of the second light-emitting diode while maintaining the side surfaces substantially free of the phosphor-containing material, wherein the second predetermined amount is different from the first predetermined amount.

2. The method of claim 1 wherein the first light-emitting diode and the first phosphor-containing material are configured to produce light of a first color, and the second light-emitting diode and the second phosphor-containing material are configured to produce light of a second color that is different from the first color.

3. The method of claim 1 wherein the phosphor particles are characterized by diameters of 2 μ

m or larger.

4. The method of claim 1 wherein the phosphor-containing material is deposited using a syringe or a needle.

5. The method of claim 1 wherein the second phosphor-containing material is different from the first phosphor-containing material.