Heat dissipation structure for solid-state light emitting device package

• US 6,480,389 B1
• Filed: 03/19/2002
• Issued: 11/12/2002
• Est. Priority Date: 01/04/2002
• Status: Expired due to Fees

• Current Assignee: Opto Tech Corporation (OptoTech Corp.)
• Original Assignee: Opto Tech Corporation (OptoTech Corp.)
• Inventors: Shie, Jin-shown, Peng, Mei-hsueh, Yen, Chih-yuan, Hung, Chien-chen
• Primary Examiner(s): THOMPSON, GREGORY D
• Application Number:
  US10/102,131
• Time in Patent Office: 238 Days
• Field of Search: 174/16.3, 174/252, 165/80.2, 165/80.3, 165/185, 257/706-707, 257/712-713, 361/704-710, 361/717-722, 361/71, 362/11, 362/294, 362/218, 362/373
• US Class Current: 361/707
• CPC Class Codes: H01L 2224/48091 Arched
• 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 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/12041 LED
• CPC Class Codes: H01L 2924/12044 OLED
• CPC Class Codes: H01L 2924/1815 Shape
• CPC Class Codes: H01L 2924/19107 off-chip wires
• CPC Class Codes: H01L 33/58 Optical field-shaping elements
• CPC Class Codes: H01L 33/648 the elements comprising fluids, e.g. heat-pipes
• CPC Class Codes: H10K 50/87 Arrangements for heating or cooling

Abstract

A light emitting diode (LED) includes a heat dissipation structure characterized by having a heat dissipating fluidic coolant filled in a hermetically sealed housing where at least one LED chip mounted on a metallic substrate is dwelled inside. The heat dissipation structure is configured with a metallic wall erected from the metallic substrate, which is used to hold a transparent cap of the sealed housing in correct position. Furthermore, the erected wall surrounds in proximity with the at least one LED chip, so that the joule heat generated therefrom can be quickly spread out, through the heat dissipating fluidic coolant, to the erected wall, and then diffused along the wall down to the metallic substrate which adjoins with a larger external heat sink for draining the heat, thus preventing the at least one LED from overheating. The other characteristic of the invention resides in that the transparent cap of the sealed housing is made of transparent materials, wherein a convex portion contacted with the heat dissipating fluidic coolant is formed on the inner surface of the transparent cap. Hence if there is any air bubble existing inside the housing due to insufficient filling, it will not dwell in the field of line-of-sight due to buoyancy. The possibility of scattering the LED light due to existing of the bubbles therefore is avoided.

Claims

1. A heat dissipation structure for a light emitting device comprising:

a metallic substrate having a top surface and a bottom surface, the top surface configured with a cup-shaped portion for the light emitting device being mounted therein and the bottom surface opposite to the top surface including a metallic solder layer deposited thereon, wherein the cup-shaped portion has an upper surface, an inner surface, and an outer surface, an electrically insulating layer deposited on the upper surface and on the outer surface, an electrically conductive electrode layer deposited on the electrically insulating layer and on the inner surface of the cup-shaped portion, and the electrically conductive electrode layer includes two divided electrodes, the one electrode formed on the inner surface of the cup-shaped portion and the other electrode formed on the upper surface and the outer surface thereof;

an electrically insulating fluidic coolant filled in the cup-shaped portion; and

a light transparent housing hermetically attached to the metallic substrate to seal the electrically insulating fluidic coolant filled in the cup-shaped portion, the light transparent housing having an inner surface configured with a convex portion opposite to the light emitting device.

2. The heat dissipation structure as recited in claim 1, wherein the metallic substrate is made of a thermally conductive material.

3. The heat dissipation structure as recited in claim 2, wherein the electrically insulating layer is made of an oxide of the thermally conductive material.

4. The heat dissipation structure as recited in claim 2, further comprising a printed circuit board including the thermally conductive material, wherein the printed circuit board has a surface with at least one electrode formed thereon, and the printed circuit board is electrically connected to the metallic substrate by joining the at least one electrode to the metallic solder layer and joining the other than at least one electrode to the electrode formed on the upper surface and the outer surface of the cup-shaped portion.

5. The heat dissipation structure as recited in claim 1, wherein the electrically conductive electrode layer is made of a light-reflective metal.

6. The heat dissipation structure as recited in claim 1, wherein the light transparent housing has an outer surface configured with a convex portion opposite to the convex portion of the inner surface of the housing.