Ceramic packaging for high brightness LED devices

• US 7,854,535 B2
• Filed: 09/23/2003
• Issued: 12/21/2010
• Est. Priority Date: 09/23/2003
• Status: Expired due to Fees

• Current Assignee: Document Security Systems, Inc.
• Original Assignee: Avago Technologies ECBU IP Singapore Pte Limited (Broadcom, Inc.)
• Inventors: Yean, Ng Kee, Weng, Lee Kong, Ee, Lee Meng
• Primary Examiner(s): Payne, Sharon E
• Application Number:
  US10/669,986
• Publication Number:
  US 20050063187A1
• Time in Patent Office: 2,646 Days
• Field of Search: 362/296, 362/800, 362/545, 362/546, 362/249, 362/327, 362/341, 313/113, 313/114
• US Class Current: 362/296.07
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48465 the other connecting portion not on the bonding area being a wedge bond, i.e. ball-to-wedge, regular stitch
• 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 33/486 adapted for surface mounting
• CPC Class Codes: Y10S 362/80 Light emitting diode

Abstract

Embodiments of the present invention include a light emitting diode package comprising a ceramic cavity comprising a substrate for mounting a light emitting diode and substantially vertical sidewalls for reducing light leakage. The ceramic LED package further includes a metallic coating on a portion of the ceramic substrate for reflecting light in a predetermined direction.

Claims

1. A standalone light emitting diode package, comprising:

a housing comprising substantially vertical sidewalls and a substrate, the sidewalls and the substrate defining a cavity having a bottom, the substrate being located at the bottom of the cavity, the substrate and the vertical sidewalls being contiguous, continuous and uninterrupted respecting one another at the intersections thereof, the housing forming a single unitary piece of ceramic;

at least one light-reflective metallic coating disposed over at least portions of the sidewalls and the substrate;

a light emitting diode mounted on or in the substrate, and an optically transparent material disposed in the cavity and covering the light emitting diode;

wherein the ceramic composition and configuration of the housing and the light-reflective coating cooperate to minimize light leakage through, into or out of the housing when the light emitting diode is energized, the metallic coating reflects light incident thereon in a predetermined direction, and the optically transparent material protects the light emitting diode.

2. The light emitting diode package of claim 1 wherein said cavity is substantially white in color.

3. The light emitting diode package of claim 1 wherein said metallic coating comprises silver.

4. The light emitting diode package of claim 1 wherein said metallic coating comprises gold.

5. The light emitting diode package of claim 1 wherein said metallic coating is formed by plating.

6. The light emitting diode package of claim 1 wherein said cavity is formed to contain a plurality of light emitting diodes.

7. A method of making a standalone light emitting diode package, the package comprising a housing having substantially vertical sidewalls and a substrate, the sidewalls and the substrate defining a cavity having a bottom, the substrate being located at the bottom of the cavity, the substrate and the vertical sidewalls being contiguous, continuous and uninterrupted respecting one another at the intersections thereof, the housing forming a single unitary piece of ceramic, at least one light-reflective metallic coating being disposed over at least portions of the sidewalls and the substrate, a light emitting diode being mounted on or in the substrate, an optically transparent material being disposed in the cavity and covering the tight emitting diode, the ceramic composition and configuration of the housing and the light-reflective coating cooperating to minimize light leakage through, into or out of the housing when the light emitting diode is energized, the metallic coating reflecting light incident thereon in a predetermined direction, and the optically transparent material protecting the light emitting diode, the method comprising:

(a) stamping the housing from the unitary piece of ceramic;

(b) coating the at least portions of the sidewalls and substrate with the at least one light-reflective metallic coating;

(c) mounting the light emitting diode on or in the substrate, and

(d) depositing the optically transparent material in the cavity.

8. The method as described in claim 7 wherein said cavity is substantially white in color.

9. The method as described in claim 7 wherein said light reflective material comprises silver.

10. The method as described in claim 7 wherein said light reflective material comprises gold.

11. The method as described in claim 7 wherein said reflective coating is formed using plating.

12. The method as described in claim 7 wherein said cavity is configured to mount a plurality of light emitting diodes therein.

13. The method as described in claim 7 further comprising depositing epoxy as the optically transparent material in the cavity.