Chip-scale methods for packaging light emitting devices and chip-scale packaged light emitting devices

• US 7,329,905 B2
• Filed: 06/30/2005
• Issued: 02/12/2008
• Est. Priority Date: 06/30/2004
• Status: Active Grant

• Current Assignee: CREE Led Incorporated (Smart Global Holdings Incorporated)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Parikh, Primit, Ibbetson, James, Keller, Bernd
• Primary Examiner(s): Tran; Minhloan
• Assistant Examiner(s): Cruz; Leslie Pilar
• Application Number:
  US11/171,893
• Publication Number:
  US 20060006404A1
• Time in Patent Office: 957 Days
• Field of Search: None
• US Class Current: 257/98
• CPC Class Codes: H01L 2224/05001 Internal layers
• CPC Class Codes: H01L 2224/05023 the whole internal layer protruding from the surface
• CPC Class Codes: H01L 2224/0508 being stacked
• CPC Class Codes: H01L 2224/051 with a principal constituent of the material being a metal or a metalloid, e.g. boron [B], silicon [Si], germanium [Ge], arsenic [As], antimony [Sb], tellurium [Te] and polonium [Po], and alloys thereof
• CPC Class Codes: H01L 2224/05568 the whole external layer protruding from the surface
• CPC Class Codes: H01L 2224/056 with a principal constituent of the material being a metal or a metalloid, e.g. boron [B], silicon [Si], germanium [Ge], arsenic [As], antimony [Sb], tellurium [Te] and polonium [Po], and alloys thereof
• CPC Class Codes: H01L 2224/16 of an individual bump connector
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/45015 being circular
• CPC Class Codes: H01L 2224/45099 Material
• 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 23/481 Internal lead connections, e.g. via connections, feedthrough structures
• CPC Class Codes: H01L 24/48 of an individual wire connector
• 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 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• 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 2924/01004 Beryllium [Be]
• CPC Class Codes: H01L 2924/01078 Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/12035 : Zener diode
• CPC Class Codes: H01L 2924/12041 : LED
• CPC Class Codes: H01L 2924/12042 : LASER
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 2924/207 : Diameter ranges
• CPC Class Codes: H01L 33/486 : adapted for surface mounting
• 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

Abstract

A packaged light emitting device includes a carrier substrate having a top surface and a bottom surface, first and second conductive vias extending from the top surface of the substrate to the bottom surface of the substrate, and a bond pad on the top surface of the substrate in electrical contact with the first conductive via. A diode having first and second electrodes is mounted on the bond pad with the first electrode is in electrical contact with the bond pad. A passivation layer is formed on the diode, exposing the second electrode of the diode. A conductive trace is formed on the top surface of the carrier substrate in electrical contact with the second conductive via and the second electrode. The conductive trace is on and extends across the passivation layer to contact the second electrode.

Methods of packaging light emitting devices include providing an epiwafer including a growth substrate and an epitaxial structure on the growth substrate, bonding a carrier substrate to the epitaxial structure of the epiwafer, forming a plurality of conductive vias through the carrier substrate, defining a plurality of isolated diodes in the epitaxial structure, and electrically connecting at least one conductive via to respective ones of the plurality of isolated diodes.

Claims

1. A packaged light emitting device, comprising:

a carrier substrate having a top surface and a bottom surface;

first and second conductive vias extending from the top surface of the substrate to the bottom surface of the substrate;

a bond pad on the top surface of the substrate in electrical contact with the first conductive via;

a diode having first and second electrodes, wherein the diode is mounted on the bond pad, and wherein the first electrode is in electrical contact with the bond pad;

a passivation layer on the diode, the passivation layer exposing the second electrode of the diode, wherein the passivation layer further covers a portion of the carrier substrate;

a conductive trace on the top surface of the carrier substrate and in electrical contact with the second conductive via and the second electrode, wherein the conductive trace is on and extends across the passivation layer to contact the second electrode; and

a reflective layer on the carrier substrate surrounding the diode, wherein the reflective layer covers portions of the passivation layer and the conductive trace.

2. The packaged light emitting device of claim 1, wherein the passivation layer further covers a portion of the bond pad.

3. The packaged light emitting device of claim 1, wherein the diode comprises an epitaxial structure from which a growth substrate has been removed.

4. The packaged light emitting device of claim 1, wherein the conductive trace forms an air bridge between the second conductive via and the second electrode.

5. The packaged light emitting device of claim 1, wherein at least one additional conductive via extends from the top surface of the substrate to the bottom surface of the substrate.

6. The packaged light emitting device of claim 1, wherein the encapsulant material includes a wavelength conversion material.

7. The packaged light emitting device LED of claim 1, further comprising a wavelength conversion material on at least a portion of a surface of the diode.

8. The packaged light emitting device of claim 1, further comprising:

a sealing layer on the reflective layer.

9. The packaged light emitting device of claim 8, wherein the sealing layer forms a hermetic seal to the reflective layer.

10. The packaged light emitting device of claim 1, wherein the diode comprises a growth substrate and an epitaxial structure on the growth substrate.

11. The packaged light emitting device of claim 10, wherein the growth substrate has a thickness less than about 150 μ

m.

12. The packaged light emitting device of claim 1, wherein the reflective layer defines a cavity above the diode.

13. The packaged light emitting device of claim 12, wherein the cavity is filled with an encapsulant material.

14. The packaged light emitting device of claim 13, wherein the encapsulant material includes a wavelength conversion material.

15. The packaged light emitting device of claim 13 wherein the encapsulant material has a refractive index of greater than 1.6.

16. The packaged light emitting device of claim 13, further comprising:

a sealing layer on the reflective layer.

17. The packaged light emitting device of claim 16, wherein the sealing layer forms a hermetic seal to the reflective layer.

18. A packaged light emitting device, comprising:

a carrier substrate having a top surface and a bottom surface;

first and second conductive vias extending from the top surface of the substrate to the bottom surface of the substrate;

a bond pad on the top surface of the substrate in electrical contact with the first conductive via;

a diode having first and second electrodes, wherein the diode is mounted on the bond pad, and wherein the first electrode is in electrical contact with the bond pad;

a passivation layer on the diode, the passivation layer exposing the second electrode of the diode;

a conductive trace on the top surface of the carrier substrate and in electrical contact with the second conductive via and the second electrode, and

a reflective layer on the carrier substrate surrounding the diode;

wherein the conductive trace is on and extends across the passivation layer to contact the second electrode, wherein the passivation layer covers a portion of the carrier substrate, wherein the passivation layer further covers a portion of the bond pad; and

wherein the reflective layer covers portions of the passivation layer and the conductive trace.