Granted Patent B2

US 6,964,877 · App. 10/832,969 · Granted Nov 15, 2005

Abstract

Claims (37)

1. A method for producing a plurality of surface mount light emitting diode (LED) packages, the method including:

fabricating a plurality of light emitting diode (LED) dice each including light emitting semiconductor layers disposed on a light-transmissive substrate, and frontside p-type and n-type contacts disposed on the light emitting semiconductor layers opposite the light-transmissive substrate;

drilling a plurality of arrays of openings into an electrically insulating sub-mount wafer;

applying a metal to the drilled openings to produce a plurality of via arrays;

flip-chip bonding the LED dice onto a frontside of the electrically insulating sub-mount wafer, the p-type and n-type contacts of each flip-chip bonded LED electrically communicating with a solderable backside of the electrically insulating sub-mount wafer through a via array;

providing a thermal conduction path for thermally conducting heat from the flip-chip bonded LED dice to the solderable backside of the electrically insulating sub-mount wafer, and

subsequent to the flip-chip bonding, separating the electrically insulating sub-mount wafer to produce surface mount LED packages each including at least one LED die.

2. The method as set forth in claim 1 , wherein the providing of a thermal conduction path includes:

selecting an electrically insulating sub-mount wafer which is thermally conductive.

3. The method as set forth in claim 1 , wherein the providing of a thermal conduction path includes:

drilling the plurality of arrays of openings with the openings of each array spatially distributed to provide substantially spatially uniform heat-sinking for the flip-chip bonded LED die.

4. The method as set forth in claim 1 , wherein the providing of a thermal conduction path includes:

incorporating designated thermal conduction paths into each array of openings; and

filling the designated thermal conduction paths with a thermally conductive material to produce thermally conductive vias that do not electrically contact the p-type and n-type contacts of the LED dice.

5. The method as set forth in claim 1 , further including:

after the flip-chip bonding and before the separating of the electrically insulating sub-mount wafer, performing at least one wafer-level processing operation on the frontside of the electrically insulating sub-mount wafer with the flip-chip bonded LED dice attached.

6. The method as set forth in claim 1 , further including:

after the flip-chip bonding and before the separating of the electrically insulating sub-mount wafer, encapsulating the frontside of the electrically insulating sub-mount wafer to hermetically seal the flip-chip bonded LED dice.

7. The method as set forth in claim 1 , further including:

forming a plurality of optical cavities in a cavity wafer, each optical cavity corresponding to one of the via arrays; and

before the separating of the electrically insulating sub-mount wafer, bonding the cavity wafer to the frontside of the electrically insulating sub-mount wafer such that the flip-chip bonded LED dice are disposed in the optical cavities.

8. A method for constructing a plurality of light emitting diode (LED) packages, the method including:

flip-chip bonding a plurality of LEDs to a frontside of an electrically insulating sub-mount wafer, the electrically insulating sub-mount wafer including front-side contacts that electrically contact electrodes of the LED during the flip-chip bonding, the electrically insulating sub-mount further including electrically conductive paths that electrically connect the front-side contacts with solderable contact pads arranged on a backside of the electrically insulating sub-mount wafer;

performing at least one wafer-level processing operation on the electrically insulating sub-mount wafer with the LEDs flip-chip bonded thereto; and

separating the electrically insulating sub-mount wafer to produce the plurality of LED packages, each LED package containing at least one of the plurality of LEDs.

9. The method as set forth in claim 8 , wherein the flip-chip bonding employs thermosonic bonding.

10. The method as set forth in claim 8 , wherein the performing of at least one wafer-level processing operation on the electrically insulating sub-mount wafer with the LEDs flip-chip bonded thereto includes:

modifying a backside surface of light-transmissive substrates of the LEDs.

11. The method as set forth in claim 10 , wherein the wafer-level processing includes at least one of:

chemically treating the electrically insulating sub-mount wafer to produce an etched pattern on the light-transmissive substrates of the LEDs,

optically coating the electrically insulating sub-mount wafer including the light-transmissive substrates of the LEDs,

applying a sealing material to the electrically insulating sub-mount wafer that encapsulates the flip-chip bonded LEDs, and

step-and-repeat applying a molded material to the LEDs on the electrically insulating sub-mount wafer, the molded material defining an encapsulant locally applied to each LED.

12. The method as set forth in claim 8 , further including:

bonding a cavity wafer to the frontside of the electrically insulating sub-mount wafer, the cavity wafer including optical cavities that receive the flip-chip bonded plurality of LEDs.

13. The method as set forth in claim 8 , wherein the separating of the electrically insulating sub-mount wafer to produce the plurality of LED packages includes:

separating along at least some of the electrically conductive paths so that the separated LED packages include electrically conductive sidewalls.

Assignments (10)