Packaging technique for the fabrication of polarized light emitting diodes

• US 7,723,746 B2
• Filed: 11/17/2008
• Issued: 05/25/2010
• Est. Priority Date: 06/21/2005
• Status: Active Grant

• Current Assignee: National Institute of Advanced Industrial Science and Technology (Government of Japan), Regents of the University of California (University of California)
• Original Assignee: Japan Science & Technology Trading Co. Limited, Regents of the University of California (University of California)
• Inventors: DenBaars, Steven P., Nakamura, Shuji, Masui, Hisashi
• Primary Examiner(s): Vu; Hung
• Application Number:
  US12/272,588
• Publication Number:
  US 20090065798A1
• Time in Patent Office: 554 Days
• Field of Search: 257 79-103, 257/E33.003, 257/E33.006, 438/22, 438/24, 438 25- 27, 438/29
• 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. A polarized light emitting apparatus, comprising:

at least one semiconductor device emitting polarized light, wherein the semiconductor device includes at least one first marker indicating a polarization direction for the polarized light emitted by the semiconductor device; and

a package for containing the semiconductor device, wherein the package includes at least one second marker indicating a polarization direction for the polarized light emitted by the semiconductor device when contained within the package, the semiconductor device is positioned within the package by aligning the first marker with the second marker, and the first and second markers are visible.

2. The apparatus of claim 1, wherein the semiconductor device is a light-emitting diode (LED).

3. The apparatus of claim 1, wherein the first marker comprises a photolithographic pattern, an electrode shape or pattern, an asymmetric shape, a notch, or a scratch.

4. The apparatus of claim 1, wherein the second marker comprises an electrode shape or pattern, an asymmetric shape, a notch, or a scratch.

5. The apparatus of claim 1, wherein the package containing the semiconductor device is installed in an external circuit or system that utilizes the light polarization, and the external circuit or system includes at least one third marker indicating a light polarization direction of the external circuit or system, wherein the package is positioned within the external circuit by aligning the second marker with the third marker.

6. The apparatus of claim 1, wherein the first and second markers are visible by naked eye, by microscope observation, by an image recognition system, or by other means.

7. The apparatus of claim 1, wherein the semiconductor device is positioned within the package by aligning the first marker with the second marker during assembly, fabrication, or production without confirming the light polarization of the device or package.

8. A method of fabricating a polarized light emitting apparatus, comprising:

obtaining at least one semiconductor device emitting polarized light, wherein the semiconductor device includes at least one first marker indicating a polarization direction for the polarized light emitted by the semiconductor device;

obtaining a package for containing the semiconductor device, wherein the package includes at least one second marker indicating a polarization direction for the polarized light emitted by the semiconductor device when contained within the package; and

positioning the semiconductor device within the package by aligning the first marker with the second marker, wherein the first and second markers are visible.

9. The method of claim 8, wherein the semiconductor device is a light-emitting diode (LED).

10. The method of claim 8, wherein the first marker comprises a photolithographic pattern, an electrode shape or pattern, an asymmetric shape, a notch, or a scratch.

11. The method of claim 8, wherein the second marker comprises an electrode shape or pattern, an asymmetric shape, a notch, or a scratch.

12. The method of claim 8, further comprising installing the package containing the semiconductor device in an external circuit or system that utilizes the light polarization, wherein the external circuit or system includes at least one third marker indicating a light polarization direction of the external circuit or system, and the package is positioned within the external circuit by aligning the second marker with the third marker.

13. The method of claim 8, wherein the first and second markers are visible by naked eye, by microscope observation, by an image recognition system, or by other means.

14. The method of claim 8, wherein the semiconductor device is positioned within the package by aligning the first marker with the second marker during assembly, fabrication, or production without confirming the light polarization of the device or package.