Light emitting diode lamp

• US 7,525,248 B1
• Filed: 01/26/2006
• Issued: 04/28/2009
• Est. Priority Date: 01/26/2005
• Status: Active Grant

• Current Assignee: AC Led Lighting, LLC
• Original Assignee: AC Led Lighting, LLC
• Inventors: Fan, Zhaoyang
• Primary Examiner(s): Patel; Vip
• Application Number:
  US11/340,296
• Time in Patent Office: 1,188 Days
• Field of Search: 313/498, 313/506, 313/512
• US Class Current: 313/512
• CPC Class Codes: F21K 9/00 Light sources using semiconductor devices as light-generating elements, e.g. using light-emitting diodes [LED] or lasers
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• 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 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01322 Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 33/64 Heat extraction or cooling elements

Abstract

A LED based solid-state light emitting device or lamp is built upon an electrically insulating layer that has been formed onto a support surface of a substrate. Specifically, the insulating layer may be epitaxially grown onto the substrate, followed by an LED buildup of an n-type semiconductor layer, an optically active layer, and a p-type semiconductor layer, in succession. Isolated mesa structure of individual, discrete LEDs is formed by etching specific portions of the LED buildup down to the insulating layer, thereby forming trenches between adjacent LEDs. Thereafter, the individual LEDs are electrically coupled together through conductive elements or traces being deposited for connecting the n-type layer of one LED and the p-type layer of an adjacent LED, continuing across all of the LEDs to form the solid-state light emitting device.

Claims

1. A LED based solid-state light emitting device comprising:

a substrate having a support surface bonded to a heat sink;

an electrically insulating layer formed on the support surface of the substrate;

one or more electrically conductive elements disposed on the insulating layer;

an array of discrete LEDs coupled with the insulating layer and electrically connected with one another in series through the one or more conductive elements; and

an encapsulation gel covering at least a portion of the substrate, the electrically insulating layer, the one or more LEDs and at least a portion of the set of electrically conductive elements.

2. The device of claim 1, wherein the insulating layer is an epitaxial layer.

3. The device of claim 1, wherein a trench is formed between adjacent LEDs of the array of discrete LEDs having a depth defined as a vertical height measured between the insulating layer and the top of the respective adjacent LEDs.

4. The device of claim 1, wherein the substrate is formed of at least one material selected from the group consisting of:

silicon carbide, silicon, gallium nitride, indium phosphide and gallium arsenic.

5. The device of claim 1, wherein the insulating layer is formed of at least one material selected from the group consisting of:

highly resistive aluminum nitride, an aluminum gallium nitride alloy and an aluminum indium gallium nitride alloy.

6. The device of claim 1, wherein the substrate is formed as electrically insulative.

7. The device of claim 6, wherein the substrate is formed of at least one material selected from the group consisting of:

the combination of sapphire and aluminum oxide, highly resistive silicon carbide, highly resistive silicon, and highly resistive aluminum nitride.

9. The device of claim 1, wherein each LED of the array of discrete LEDs has a p-type contact connected with one of the conductive elements and a n-type contact connected with another one of the conductive elements, wherein the conductive element connected with the p-type contact of a respective LED extends to another n-type contact of a first adjacent LED, and the conductive element connected with the n-type contact of the respective LED extends to another p-type contact of a second adjacent LED.

8. The device of 6, wherein the insulating layer is formed of at least one material selected from the group consisting of:

highly resistive aluminum nitride, aluminum gallium nitride and aluminum indium gallium nitride.

10. A LED based solid-state light emitting device comprising:

a non-electrically insulative substrate bonded to a heat sink submount;

an electrically insulating layer formed on the support surface of the substrate;

one or more LEDs formed on the insulating layer each having a n-type semiconductor layer, an optically active layer, and a p-type semiconductor layer, the one or more LEDs being electrically coupled with one another in series;

a set of electrically conductive elements each extending from the one or more LEDs to an electrical lead; and

an encapsulation gel covering at least a portion of the substrate, the electrically insulating layer, the one or more LEDs and at least a portion of the set of electrically conductive elements.

11. The device of claim 10, further comprising:

one or more color conversion phosphors disposed onto the encapsulation gel above the one or more LEDs;

an encapsulation lens formed on top of the one or more color conversion phosphors.

12. The device of claim 11, further comprising an electrically insulative sidewall surrounding at least the substrate, the electrically insulating layer, the one or more LEDs, and the encapsulation gel, wherein the sidewall defines a boundary for the encapsulation gel.