LIGHT EMITTING DEVICE AND METHOD OF MANUFACTURING THE SAME

• US 20160093777A1
• Filed: 09/30/2015
• Published: 03/31/2016
• Est. Priority Date: 09/30/2014
• Status: Active Grant

• Current Assignee: Nichia Corporation
• Original Assignee: Nichia Corporation
• Inventors: SATO, Daisuke, HASHIZUME, Atsushi, NISHIHAMA, Toshiki, MAEDA, Shimpei
• Granted Patent: US 9,577,161 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/73253 Bump and layer connectors
• CPC Class Codes: H01L 25/167 comprising optoelectronic devices, e.g. LED, photodiodes
• 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 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2924/10155 being other than a cuboid
• CPC Class Codes: H01L 2924/181 Encapsulation
• 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 33/504 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 33/508 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 33/52 Encapsulations
• CPC Class Codes: H01L 33/58 Optical field-shaping elements
• CPC Class Codes: H01L 33/60 Reflective elements

Abstract

The light emitting device includes a light emitting element, a wavelength converter, and a light guider. The light emitting element has an element upper surface, an element lower surface, and an element side surface. The wavelength converter has a converter lower surface. The wavelength is provided to be connected to the light emitting element. The converter lower surface has an exposed region that does not face the element upper surface. The light guider guides light from the light emitting element to the wavelength converter. The light guider covers the element side surface and the exposed region. The wavelength converter includes first and second wavelength converter parts. The first wavelength converter part faces the element upper surface and has a first thickness. The second wavelength converter part does not face the element upper surface and has a second thickness thinner than the first thickness.

Claims

1. A light emitting device comprising:

a light emitting element having an element upper surface, an element lower surface opposite to the element upper surface in a thickness direction of the light emitting element, and an element side surface between the element upper surface and the element lower surface;

a wavelength converter having a converter lower surface and provided to be connected to the light emitting element such that the converter lower surface faces the element upper surface, the converter lower surface having an exposed region that does not face the element upper surface viewed along the thickness direction, the wavelength converter comprising;

a first wavelength converter part facing the element upper surface viewed along the thickness direction and having a first thickness in the thickness direction; and

a second wavelength converter part not facing the element upper surface viewed along the thickness direction and having a second thickness in the thickness direction, the second thickness being thinner than the first thickness; and

a light guider to guide light from the light emitting element to the wavelength converter, the light guider covering the element side surface and the exposed region.

3. The light emitting device according to claim 1, further comprising a light reflector covering the wavelength converter and the light guider.

5. The light emitting device according to claim 1,

wherein the light emitting element is joined to the wavelength converter via an adhesive,

wherein the adhesive includes the light guider.

7. The light emitting device according to claim 1, further comprising a light transmitting layer,

wherein the wavelength converter has a converter upper surface opposite to the converter lower surface in the thickness direction,

wherein the light transmitting layer has a layer lower surface facing the converter upper surface, and

wherein the converter upper surface has the substantially same area as the layer lower surface, and

wherein the second thickness becomes thinner as the second wavelength converter part separates from the light emitting element.

8. The light emitting device according to claim 7, wherein the second thickness becomes thinner as the second wavelength converter part separates from the light emitting element in a curved shape.

10. The light emitting device according to claim 7, wherein the light transmitting layer includes glass.

12. The light emitting device according to claim 7, wherein the light transmitting layer includes a light diffuser.

2. A light emitting device comprising:

a light emitting element having an element upper surface, an element lower surface opposite to the element upper surface in a thickness direction of the light emitting element, and an element side surface between the element upper surface and the element lower surface;

a wavelength converter having a converter lower surface and provided to be connected to the light emitting element such that the converter lower surface faces the element upper surface, the converter lower surface having an exposed region that does not face the element upper surface viewed along the thickness direction, the wavelength converter having a converter upper surface opposite to the converter lower surface in the thickness direction;

a light guider to guide light from the light emitting element to the wavelength converter, the light guider covering the element side surface and the exposed region; and

a light transmitting layer having a layer lower surface facing the converter upper surface smaller than the layer lower surface.

4. The light emitting device according to claim 2, further comprising a light reflector covering the wavelength converter and the light guider.

6. The light emitting device according to claim 2,

wherein the light emitting element is joined to the wavelength converter via an adhesive,

wherein the adhesive includes the light guider.

9. The light emitting device according to claim 2, wherein the light transmitting layer includes glass.

11. The light emitting device according to claim 2, wherein the light transmitting layer includes a light diffuser.

13. A method of manufacturing a light emitting device, the method comprising:

providing a light emitting element having an element upper surface, an element lower surface opposite to the element upper surface in a thickness direction of the light emitting element, and an element side surface between the element upper surface and the element lower surface;

providing a wavelength converter having a converter lower surface; and

joining the wavelength converter to the light emitting element using an adhesive so that the converter lower surface faces the element upper surface, the converter lower surface having an exposed region that does not face the element upper surface viewed along the thickness direction, the adhesive covering the element side surface and the exposed region.

14. The method according to claim 13,

wherein the providing the wavelength converter comprises:

forming a wavelength conversion member on a light transmitting member;

forming a groove at the wavelength conversion member; and

dividing the light transmitting member at the groove so that the wavelength converter that is provided on a light transmitting layer is prepared.

15. The method according to claim 14,

wherein the wavelength converter has a converter upper surface opposite to the converter lower surface in the thickness direction,

wherein the light transmitting layer has a layer lower surface facing the converter upper surface, and

wherein the dividing the light transmitting member includes forming the wavelength converter and the light transmitting layer so that the converter upper surface is smaller than the layer lower surface.

16. The method according to claim 14, wherein the groove has a tapered shape.

17. The method according to claim 14, wherein the groove has a curved shape.

18. The method according to claim 14,

wherein the wavelength converter to the light emitting element comprises:

disposing the wavelength converter provided on the light transmitting layer to the light emitting element via the adhesive; and

applying pressure to the light transmitting layer so that the adhesive covers the element side surface and the exposed region.