Distributed LED-Based Light Source

• US 20110068672A1
• Filed: 09/22/2010
• Published: 03/24/2011
• Est. Priority Date: 09/22/2010
• Status: Active Grant

• Current Assignee: Bridgelux Incorporated
• Original Assignee: Bridgelux Incorporated
• Inventors: Hasnain, Ghulam
• Granted Patent: US 8,035,284 B2
• Time in Patent Office: Days
• US Class Current: 313/46
• 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: F21V 23/005 the substrate is supporting also the light source
• CPC Class Codes: F21V 29/507 of means for protecting lighting devices from damage, e.g. housings
• CPC Class Codes: F21V 29/70 characterised by passive heat-dissipating elements, e.g. heat-sinks
• CPC Class Codes: H01L 2224/48091 Arched
• 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: H05K 1/0203 Cooling of mounted components H05K1/0272 takes precedence
• CPC Class Codes: H05K 1/0206 by printed thermal vias
• CPC Class Codes: H05K 1/05 Insulated conductive substrates, e.g. insulated metal substrate
• CPC Class Codes: H05K 2201/10106 Light emitting diode [LED]

Abstract

A light source having a substrate with a plurality of component LED light generators mounted thereon is disclosed. The substrate has a first metallic surface characterized by a normal that points in a normal direction. The first metallic surface is in contact with air over the first metallic surface. The component LED light generators are mounted directly on the first metallic surface. Each component LED light generator includes an LED characterized by an operating temperature and emitting light in the normal direction. Each LED generator generates more than 0.5 watts of heat. The component LED light generators are spaced apart on the first metallic surface such that the operating temperature remains less than 75° C. above the air temperature. In one aspect of the invention, the first metallic surface surrounding each component LED light generator radiates an amount of heat equal to the heat generated by that component LED light generator.

Claims

1. A light source comprising:

a substrate having a first metallic surface, said first metallic surface characterized by a normal that points in a normal direction, said first metallic surface being in contact with air over said first metallic surface, said air being characterized by an air temperature; and

a plurality of component LED light generators mounted directly on said first metallic surface, each component LED light generator comprising an LED characterized by an operating temperature, each LED generator generating more than 0.5 watts of heat, said LEDs generating light that leaves said light source in said normal direction, wherein said component LED light generators are spaced apart on said first metallic surface such that said operating temperature remains less than 75°

C. above said air temperature.

2. The light source of claim 1 wherein said first metallic surface surrounding each component LED light generator radiates an amount of heat equal to the heat generated by that component LED light generator.

3. The light source of claim 1 wherein said component LED light generators are spaced such that the heat generated on any square inch of said metallic surface is less than 2 watts.

4. The light source of claim 1 wherein said component LED light generators are spaced such that the heat generated on any square inch of said metallic surface is less than 1 watt.

5. The light source of claim 1 wherein said light source further comprises a second metallic surface in thermal communication with said first metallic surface and positioned to dissipate additional heat from said first metallic surface.

6. The light source of claim 1 wherein said first metallic surface is planar.