Micro-reflectors on a substrate for high-density LED array

• US 7,638,808 B2
• Filed: 03/18/2005
• Issued: 12/29/2009
• Est. Priority Date: 03/18/2004
• Status: Active Grant

• Current Assignee: Phoseon Technology, Inc.
• Original Assignee: Phoseon Technology, Inc.
• Inventors: Schreiner, Alexander F., Anderson, Duwayne R., Owen, Mark D., McNeil, Thomas R.
• Primary Examiner(s): Tran; Thien F
• Application Number:
  US11/084,466
• Publication Number:
  US 20050218468A1
• Time in Patent Office: 1,747 Days
• Field of Search: 257/88, 257 98-100
• US Class Current: 257/88
• CPC Class Codes: H01L 2224/48091 Arched
• 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 2924/09701 Low temperature co-fired ceramic [LTCC]
• CPC Class Codes: H01L 2924/10253 Silicon [Si]
• CPC Class Codes: H01L 2924/3025 Electromagnetic shielding
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector
• CPC Class Codes: H01L 33/60 Reflective elements
• CPC Class Codes: H01L 33/62 Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls
• CPC Class Codes: H01L 33/64 Heat extraction or cooling elements

Abstract

The present invention provides an optical array module that includes a plurality of semiconductor devices mounted on a thermal substrate formed with a plurality of openings that function as micro-reflectors, wherein each micro-reflector includes a layer of reflective material to reflect light. Such material preferably is conductive so as to provide electrical connection for its associated semiconductor device.

Claims

1. An optical array module, comprising:

a thermally conductive and electrically insulative substrate;

a plurality of micro-reflectors arranged in an M×

N array, M>

1 and N>

1, and a plurality of light-emitting semiconductor devices arranged on the substrate, wherein a selected number of such plurality of semiconductor devices are disposed on and associated with each such micro-reflector, and wherein light emitted from such selected number of semiconductor devices is substantially collected by the associated micro-reflectors so as to enhance the optical power density from the semiconductor devices; and

wherein each micro-reflector comprises a layer of conductive material, the conductive material providing electrical connection for an associated semiconductor device.

2. The optical array module of claim 1, wherein the micro-reflectors are arranged in an array having a center-to-center spacing of about 3 mm or less.

3. The optical array module of claim 1, wherein a side of each micro-reflectors is about 700 square microns.

4. The optical array module of claim 1, wherein each micro-reflector is formed in a truncated pyramidal shape.

5. The optical array module of claim 4, the substrate having a plurality of openings in its surface, the openings being substantially square at the surface, and having sidewalls cut into the substrate that slope to a base, so as to create a truncated pyramidal shape and wherein each such opening provides for formation of a respective one micro-reflector.

6. The optical array module of claim 1, wherein each micro-reflector has a parabolic shape.

7. The optical array module of claim 1, further including an array of micro-lenses, and one or more micro-reflectors is associated with a respective micro-lens, in connection with collection and collimation of light emitted from one or more selected semiconductor devices located within the associated micro-reflector.

8. The optical array module of claim 1, wherein the micro-reflector includes a layer of reflective and conductive material, such reflective material reflecting selected wavelength(s) of light from one or more selected semiconductor devices located within the associated micro-reflector.

9. The optical array module of claim 8, wherein the reflective and conductive material includes silver or aluminum, whereby selected wavelength(s) in the UV spectra are reflected.

10. The optical array module of claim 8, wherein the reflective and conductive material includes gold, whereby selected wavelength(s) in the visible spectra are reflected.

11. The optical array module of claim 1, further comprising a material layered on such substrate, the material having a plurality of openings in its surface, wherein each such opening provides for formation of a respective one micro-reflector.

12. The optical array module of claim 11, wherein the openings enter the substrate.

13. The optical array module of claim 1, wherein the micro-reflector includes a layer of reflective material, such reflective material and the conductive material being the same layer.

14. The optical array module of claim 1 wherein the substrate comprises one or more of ceramic, plastic, diamond, SiC, AlN, BeO, Al₂O₃.