Method for applying phosphor to light emitting diodes and apparatus thereof

• US 10,193,031 B2
• Filed: 03/10/2017
• Issued: 01/29/2019
• Est. Priority Date: 03/11/2016
• Status: Active Grant

• Current Assignee: Cowles SEMI LLC
• Original Assignee: Rohinni LLC
• Inventors: Huska, Andrew, Peterson, Cody, Adams, Clinton, Hansen, Monica
• Primary Examiner(s): Everhart, Caridad
• Assistant Examiner(s): Singal, Ankush
• Application Number:
  US15/456,435
• Publication Number:
  US 20170263826A1
• Time in Patent Office: 690 Days
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 2933/0033 relating to semiconductor body packages
• CPC Class Codes: H01L 2933/0041 relating to wavelength conversion elements
• CPC Class Codes: H01L 2933/005 relating to encapsulations
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector
• CPC Class Codes: H01L 33/501 characterised by the materials, e.g. binder
• CPC Class Codes: H01L 33/505 characterised by the shape, e.g. plate or foil

Abstract

A method of applying phosphor to an unpackaged Light-Emitting Diode (LED) die includes transferring the unpackaged LED die directly to a product substrate; disposing a coverlay on the product substrate to create a cavity around the unpackaged LED die; and applying phosphor to substantially fill the cavity around the unpackaged LED die, the applying including at least one of using a squeegee to place the phosphor into the cavity, spraying the cavity with the phosphor, or disposing the phosphor in a sheet form onto the unpackaged LED die.

Claims

1. A Light-Emitting Diode (LED) system comprising:

a substrate;

an LED die attached to the substrate via a bottom side of the LED die;

an at least partly reflective film attached to a top side of the LED die; and

phosphor attached to one or more sides of the LED die via application of a coverlay that forms a cavity around the LED die and the application including at least one of using a squeegee to place the phosphor into the cavity, spraying the cavity with the phosphor, or disposing the phosphor in a sheet form onto the LED die.

2. The LED system of claim 1, wherein the phosphor extends from at least one of the one or more sides of the LED die a distance that is greater than a width of the LED die.

3. The LED system of claim 1, wherein the phosphor extends from at least one of the one or more sides of the LED die between about 5 microns and about 500 microns.

4. The LED system of claim 1, wherein the LED die is a first LED die,

wherein the LED system further comprises a second LED die attached to the substrate, and

wherein the phosphor extends from a side of the one or more sides of the first LED die to a side of the second LED die.

5. The LED system of claim 1, wherein the at least partly reflective film reflects more than 30% of light.

6. The LED system of claim 1, wherein the LED die is an unpackaged LED die that is attached directly to the product substrate.

7. The LED system of claim 1, wherein a thickness of the LED die is between about 50 microns and about 80 microns.

8. The LED system of claim 1, wherein the at partly reflective film is a first at least partly reflective film, and

wherein the LED system further comprises a second at least partly reflective film positioned between the substrate and the bottom side of the LED die.

9. The LED system of claim 1, wherein the application includes disposing the phosphor in a sheet form, and

wherein the sheet of phosphor is attached directly to the top side of the LED die.

10. The LED system of claim 9, wherein the sheet of phosphor is attached to the top side of the LED die with an adhesive.