WAVELENGTH CONVERTED SEMICONDUCTOR LIGHT EMITTING DEVICE

• US 20160163931A1
• Filed: 07/03/2014
• Published: 06/09/2016
• Est. Priority Date: 07/08/2013
• Status: Active Grant

• Current Assignee: Lumileds LLC (Apollo Global Management, Inc.)
• Original Assignee: Koninklijke Philips N.V.
• Inventors: Schricker, April Dawn, Shchekin, Oleg Borisovich, Choi, Han Ho, Schmidt, Peter Josef
• Granted Patent: US 9,761,768 B2
• Time in Patent Office: Days
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/73204 the bump connector being embedded into the layer connector
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 27/156 two-dimensional arrays
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2933/0041 relating to wavelength conversion elements
• CPC Class Codes: H01L 2933/0058 relating to optical field-shaping elements
• CPC Class Codes: H01L 33/501 characterised by the materials, e.g. binder
• CPC Class Codes: H01L 33/504 Elements with two or more wavelength conversion materials
• CPC Class Codes: H01L 33/505 characterised by the shape, e.g. plate or foil
• CPC Class Codes: H01L 33/60 Reflective elements

Abstract

In embodiments of the invention, a light emitting device includes a semiconductor structure including a light emitting layer disposed between an n-type region and a p-type region. A first wavelength converting layer is disposed in a path of light emitted by the light emitting layer. The first wavelength converting layer may be a wavelength converting ceramic. A second wavelength converting layer is fused to the first wavelength converting layer. The second wavelength converting layer may be a wavelength converting material disposed in glass.

Claims

1. A light emitting device comprising:

a semiconductor structure comprising a light emitting layer disposed between an n-type region and a p-type region;

a first wavelength converting layer disposed in a path of light emitted by the light emitting layer, wherein the first wavelength converting layer comprises a wavelength converting ceramic; and

a second wavelength converting layer fused to the first wavelength converting layer, wherein the second wavelength converting layer comprises a wavelength converting material disposed in glass, wherein the first wavelength converting layer is disposed between the second wavelength converting layer and the semiconductor structure.

2. The light emitting device of claim 1 wherein the first wavelength converting layer emits red light and the second wavelength converting layer emits green light.

4. The light emitting device of claim 1 wherein the first wavelength converting layer and the second wavelength converting layer have angled sidewalls.

5. The light emitting device of claim 1 wherein:

the first wavelength converting layer and the second wavelength converting layer form a wavelength converting member;

a first portion of the wavelength converting member has a substantially vertical sidewall; and

a second portion of the wavelength converting member has an angled sidewall.

6. The light emitting device of claim 1 further comprising a reflective material, wherein the reflective material is disposed adjacent each of a sidewall of the first wavelength converting layer, a sidewall of the second wavelength converting layer, and a sidewall of the semiconductor structure.

3. (canceled)

7. A method comprising:

forming a wavelength converting element, said forming comprising;

forming a first wavelength converting layer, wherein the first wavelength converting layer is a wavelength converting ceramic;

fusing a second wavelength converting layer to the first wavelength converting layer, wherein fusing a second wavelength converting layer to the first wavelength converting layer comprises;

mixing a wavelength converting material with glass;

rolling the mixture into a sheet;

cutting the sheet to fit the first wavelength converting layer; and

fusing the cut sheet to the first wavelength converting layer;

dicing the wavelength converting element into a plurality of platelets; and

after said dicing, attaching a platelet to a semiconductor light emitting device.

8. The method of claim 7 wherein forming a first wavelength converting layer comprises sintering a phosphor into a wafer.

10. The method of claim 7 wherein fusing the cut sheet comprises heating the cut sheet and the first wavelength converting layer to a temperature greater than a reflow temperature of the glass.

12. The method of claim 7 further comprising thinning the first wavelength converting layer prior to fusing the second wavelength converting layer to the first wavelength converting layer.

13. The method of claim 7 further comprising thinning the second wavelength converting layer after fusing the second wavelength converting layer to the first wavelength converting layer.

14. The method of claim 7 further comprising:

attaching a plurality of semiconductor light emitting device to a mount;

attaching a platelet to each semiconductor light emitting device in the plurality;

disposing reflective material between neighboring semiconductor light emitting devices in the plurality.

15. The method of claim 14 further comprising thinning the reflective material after disposing the reflective material between neighboring semiconductor light emitting devices.

16. The method of claim 7 wherein dicing the wavelength converting element into a plurality of platelets comprises forming an angled sidewall on each platelet.

17. The method of claim 7 wherein dicing the wavelength converting element into a plurality of platelets comprises:

forming on a first portion of each platelet a sidewall having a first angle relative to a top surface of the platelet; and

forming on a second portion of each platelet a sidewall having a second angle relative to a top surface of the platelet;

wherein the first angle is different from the second angle.

9. (canceled)

11. A method comprising:

forming a wavelength converting element, said forming comprising;

forming a first wavelength converting layer, wherein the first wavelength converting layer is a wavelength converting ceramic;

fusing a second wavelength converting layer to the first wavelength converting layer, wherein fusing a second wavelength converting layer to the first wavelength converting layer comprises;

mixing a wavelength converting material with glass;

depositing the mixture on the first wavelength converting layer;

spreading the mixture to form a substantially uniform thickness layer;

dicing the wavelength converting element into a plurality of platelets; and

after said dicing, attaching a platelet to a semiconductor light emitting device.