Packaging technique for the fabrication of polarized light emitting diodes

• US 20060284206A1
• Filed: 06/21/2006
• Published: 12/21/2006
• Est. Priority Date: 06/21/2005
• Status: Active Grant

• Current Assignee: Japan Science And Technology Agency
• Original Assignee: Japan Science And Technology Agency
• Inventors: DenBaars, Steven P., Nakamura, Shuji, Masui, Hisashi
• Granted Patent: US 7,518,159 B2
• Time in Patent Office: Days
• US Class Current: 257/98
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/13362 providing polarized light, e.g. by converting a polarisation component into another one
• CPC Class Codes: H01L 2223/54426 for alignment
• CPC Class Codes: H01L 2223/54473 for use after dicing
• CPC Class Codes: H01L 2223/54486 Located on package parts, e.g. encapsulation, leads, package substrate
• CPC Class Codes: H01L 23/544 Marks applied to semiconductor devices or parts, e.g. registration marks, alignment structures, wafer maps test patterns for characterising or monitoring manufacturing processes H01L22/00
• 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 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 33/16 with a particular crystal structure or orientation, e.g. polycrystalline, amorphous or porous
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/483 Containers

Abstract

A polarized light emitting diode (LED) includes a marker indicating a polarization direction. A package for the LED also includes a marker indicating the polarization direction. The markers on the LED and package are used for mutual alignment, wherein the LED is attached in a favorable orientation with respect to a package, so that the polarization direction of emitted light from the package is apparent. The marker is placed on the LED before die separation and the marker is placed on the package before alignment. The marker on the LED comprises a photolithographic pattern, an asymmetric die shape, a notch on the die, or a scratch on the die, while the marker on the package comprises an electrode shape or pattern, an asymmetric package shape, a notch on the package, or a scratch on the package. Finally, the LED or package may be installed in an external circuit or system that also indicates the polarization direction.

Claims

1. At least one polarized light emitting diode (LED) including at least one marker indicating a light polarization direction.

2. The polarized LED of claim 1, wherein the LED is attached in a favorable orientation with respect to a package, so that the light polarization direction of emitted light from the LED is apparent.

3. The polarized LED of claim 2, wherein the package includes at least one additional marker indicating the light polarization direction.

4. The polarized LED of claim 3, wherein the marker on the LED and the additional marker on the package are used for mutual alignment.

5. The polarized LED of claim 4, wherein the marker is placed or defined on the LED before die separation and the additional marker is placed or defined on the package before alignment.

6. The polarized LED of claim 4, wherein the marker on the LED comprises a photolithographic pattern, an electrode shape or pattern, an asymmetric die shape, a notch on the die, or a scratch on the die.

7. The polarized LED of claim 4, wherein the additional marker on the package comprises an electrode shape or pattern, an asymmetric package shape, a notch on the package, or a scratch on the package.

8. The polarized LED of claim 1, wherein the LED is installed in an external circuit or system that utilizes the light polarization, and the external circuit or system has a similar marker for mutual alignment.

9. An array of the polarized LEDs of claim 1.

10. A method of fabricating at least one polarized light emitting diode (LED), comprising indicating a light polarization direction on the LED.

11. The method of claim 10, wherein the light polarization direction is determined from knowledge of the crystallographic orientation of the LED.

12. The method of claim 10, further comprising attaching the LED in a favorable orientation with respect to a package, so that the polarization direction of emitted light from the package is apparent.

13. The method of claim 12, further comprising indicating the light polarization direction on the package.

14. The method of claim 13, wherein the indicating comprises placement or definition of at least one marker on the LED and at least one additional marker on the package for mutual alignment.

15. The method of claim 14, further comprising the placement or definition of at least one marker on each potential LED die before die separation and at least one additional marker defined or placed on each package before alignment.

16. The method of claim 14, wherein the marker on the LED comprises a photolithographic pattern, an electrode shape or pattern, an asymmetric die shape, a notch on the die, or a scratch on the die.

17. The method of claim 14, wherein the additional marker on the package comprises an electrode shape or pattern, an asymmetric package shape, a notch on the package, or a scratch on the package.

18. The method of claim 10, further comprising indicating the light polarization direction on an external circuit or system in which the LED is installed, and mutually aligning the LED and the external circuit or system.

19. The method of claim 10 further comprising matching the orientation of multiple LED dies.

20. At least one Light Emitting Diode having at least one orientation dependent emission characteristic including at least one marker indicating an orientation of the LED for which the orientation dependent characteristic is a maximum.

21. A method of fabricating at least one light emitting diode (LED) having an orientation dependent emission characteristic, comprising indicating an orientation of the LED for which the orientation dependent characteristic is a maximum.