WAVELENGTH CONVERTED SEMICONDUCTOR LIGHT EMITTING DEVICE

• US 20180033923A1
• Filed: 08/17/2017
• Published: 02/01/2018
• Est. Priority Date: 07/08/2013
• Status: Active Grant

• Current Assignee: Lumileds LLC (Apollo Global Management, Inc.)
• Original Assignee: Lumileds LLC (Apollo Global Management, Inc.)
• Inventors: SCHRICKER, April Dawn, SHCHEKIN, Oleg Borisovich, CHOI, Han Ho, SCHMIDT, Peter Josef
• Granted Patent: US 10,270,013 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 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;

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

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

2. The method of claim 1 wherein forming a first wavelength converting layer comprises sintering a phosphor into a wafer.

3. The method of claim 1 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.

4. The method of claim 3 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.

5. The method of claim 1 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; and

spreading the mixture to form a substantially uniform thickness layer.

6. The method of claim 1 further comprising thinning the first wavelength converting layer prior to fusing the second wavelength converting layer to the first wavelength converting layer.

7. The method of claim 1 further comprising thinning the second wavelength converting layer after fusing the second wavelength converting layer to the first wavelength converting layer.

8. The method of claim 1 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; and

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

9. The method of claim 8 further comprising thinning the reflective material after disposing the reflective material between neighboring semiconductor light emitting devices.

10. The method of claim 1 wherein dicing the wavelength converting element into a plurality of platelets comprising forming an angled sidewall on each platelet.

11. The method of claim 1 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.