Cluster packaging of light emitting diodes

• US 6,635,503 B2
• Filed: 01/28/2002
• Issued: 10/21/2003
• Est. Priority Date: 01/28/2002
• Status: Expired due to Term

• Current Assignee: CREE Led Incorporated (Smart Global Holdings Incorporated)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Andrews, Peter S., Slater, David B. Jr.
• Primary Examiner(s): Nelms, David
• Assistant Examiner(s): LE, THAO P
• Application Number:
  US10/058,369
• Publication Number:
  US 20030143767A1
• Time in Patent Office: 631 Days
• Field of Search: 438/27, 438/28, 438/29, 438/20, 438/22, 257/79, 257/80, 257/88
• US Class Current: 438/27
• CPC Class Codes: H01L 21/78 with subsequent division of the substrate into plural individual devices cutting to change the surface-physical characteristics or shape of semiconductor bodies H01L21/304
• CPC Class Codes: H01L 27/156 two-dimensional arrays
• CPC Class Codes: H01L 33/0095 Post-treatment of devices, e.g. annealing, recrystallisation or short-circuit elimination

Abstract

Methods of forming a light emitting diode are provided by scoring a semiconductor substrate having a light emitting region formed thereon so as to provide score lines between individual ones of a plurality of light emitting diodes. The semiconductor substrate is then broken along selected ones of the score lines so as to provide a unitized subset of the plurality of light emitting diodes. The unitized subset includes at least two light emitting diodes. Electrical connections are provided to the light emitting diodes of the unitized subset of the plurality of light emitting diodes. The score lines may also define the individual ones of the light emitting diodes.

Claims

1. A method of forming a light emitting diode, comprising:

scoring a semiconductor substrate having a light emitting region formed thereon so as to provide score lines between individual ones of a plurality of light emitting diodes;

then

separating the semiconductor substrate along selected ones of the score lines so as to provide a unitized subset of the plurality of light emitting diodes, the unitized subset including at least two light emitting diodes; and

providing electrical connections to light emitting diodes of the unitized subset of the plurality of light emitting diodes.

2. The method of claim 1, wherein the semiconductor substrate comprises a silicon carbide substrate.

3. The method of claim 1, wherein the semiconductor substrate comprises a sapphire substrate.

4. The method of claim 1, wherein the selected ones of the score lines along which the semiconductor substrate is separated comprise score lines selected to provide a strip of light emitting diodes as the unitized subset.

5. The method of claim 1, wherein the selected ones of the score lines along which the semiconductor substrate is separated comprise score lines selected to provide a rectangle of light emitting diodes having at least two parallel rows of light emitting diodes as the unitized subset.

6. The method of claim 1, wherein the selected ones of the score lines along which the semiconductor substrate is separated comprise score lines selected provide a square of light emitting diodes as the unitized subset.

7. The method of claim 1, wherein the step of providing electrical connections comprises the step of soldering to contacts of the light emitting diodes.

8. The method of claim 1, wherein the plurality of light emitting diodes of the unitized subset of light emitting diodes have a common contact for each of the light emitting diodes in the unitized subset and individual contacts corresponding to each of the light emitting diodes in the unitized subset, and wherein the step of providing electrical connections comprises the steps of:

providing a common connection for the common contact; and

providing parallel connection of the individual contacts.

9. The method of claim 8, wherein the step of providing a common connection comprises the step of soldering a connection to the common contact.

10. The method of claim 8, wherein the step of providing parallel connection comprises the step of connecting ones of the individual contacts to a conducting bus strip.

11. The method of claim 8, wherein the step of providing parallel connection comprises the steps of:

connecting a first of the individual contacts to a conducting bus; and

daisy-chaining remaining ones of the individual contacts to the first of the individual contacts.

12. The method of claim 1, wherein the selected ones of the score lines along which the semiconductor substrate is separated comprise score lines selected to provide a unitized subset of light emitting diodes that provided a selected wavelength profile.

13. The method of claim 12, wherein the selected wavelength profile comprises a selected range of wavelengths.

14. The method of claim 1, wherein the selected ones of the score lines along which the semiconductor substrate is separated comprise score lines selected to provide a unitized subset of light emitting diodes that provided a selected light output level.

15. The method of claim 1, wherein the score lines provide an ATON shape to ones of the light emitting diodes.

16. The method of claim 1, wherein the step of providing electrical connections to light emitting diodes of the unitized subset of the plurality of light emitting diodes comprises selectively connecting the light emitting diodes of the unitized subset of the plurality of light emitting diodes so as to provide a set of light emitting diodes having a predefined characteristic.

17. The method of claim 16, wherein the predefined characteristic comprises a light output characteristic.

18. The method of claim 16, wherein the predefined characteristic comprises an electrical characteristic.

19. The method of claim 18, wherein the electrical characteristic comprises a forward bias voltage.

20. The method of claim 1, wherein the score lines define individual ones of the plurality of light emitting diodes.