Full color light emitting diode display assembly

• US 5,583,350 A
• Filed: 11/02/1995
• Issued: 12/10/1996
• Est. Priority Date: 11/02/1995
• Status: Expired due to Term

• Current Assignee: Freescale Semiconductor, Inc. (NXP Semiconductors NV)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Norman, Michael P., Holm, Paige M.
• Primary Examiner(s): TRAN, MINH LOAN
• Application Number:
  US08/552,155
• Time in Patent Office: 404 Days
• Field of Search: 257/13, 257/88, 257/89, 257/90, 257/91, 257/92, 257/103, 257/40, 362/800, 313/500, 313/510, 361/805, 361/806
• US Class Current: 257/88
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• 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 33/0025 comprising only AIIIBV compounds
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 59/00 Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
• CPC Class Codes: H10K 59/32 Stacked devices having two or more layers, each emitting at different wavelengths
• CPC Class Codes: H10K 59/35 comprising red-green-blue [RGB] subpixels

Abstract

A full color light emitting diode display (310) utilizes semiconductor light emitting diodes (313) to produce red light and either organic or semiconductor light emitting diodes (312) to produce blue light. Green light is produced by either semiconductor light emitting diodes (313) or by organic light emitting diodes (343). An array of semiconductor light emitting diodes is formed on a semiconductor substrate (322) and an array of organic or semiconductor light emitting diodes is formed on an optically transparent substrate (311). The optically transparent and semiconductor substrates are attached together to form the multi-wavelength light emitting diode display (310).

Claims

1. A full color light emitting diode display comprising:

an optically transparent substrate;

a first light emitting diode formed on the optically transparent substrate and constructed to emit light of a first wavelength, the first light emitting diode being an organic light emitting diode;

a semiconductor substrate;

a second light emitting diode constructed to emit light of a second wavelength and a third light emitting diode constructed to emit light of a third wavelength, different than the second wavelength, the second and third light emitting diodes being semiconductor light emitting diodes constructed on the semiconductor substrate and stacked together and positioned to both emit light in a same direction wherein one of the second and third light emitting diodes is transparent to light emitted by the other of the second and third light emitting diodes; and

a plurality of mounting pads on the optically transparent substrate, the semiconductor substrate being attached to the plurality of mounting pads wherein the first light emitting diode cooperates with the second and third light emitting diodes to generate a pixel of the display.

2. The full color light emitting diode display of claim 1 wherein one of the second and third light emitting diodes emits light of a shorter wavelength than other of the second and third light emitting diodes.

3. The full color light emitting diode display of claim 2 wherein the light emitted by the one of the second and third light emitting diodes is green and light emitted by the other of the first and second light emitting diodes is red.

4. The full color light emitting diode display of claim 1 wherein each of the second and third light emitting diodes includes an active layer of material sandwiched between two confinement layers of material.

5. The full color light emitting diode display of claim 1 wherein the optically transparent substrate is one of glass, transparent plastic, gallium nitride, sapphire.

6. The full color light emitting diode display of claim 1 wherein the plurality of mounting pads attaches the semiconductor substrate to the optically transparent substrate, the plurality of mounting pads being one of conductive epoxy bumps or solder bumps.

7. A full color light emitting diode display comprising:

an optically transparent substrate;

a first light emitting diode constructed to emit a first light of a first wavelength and to emit a second light of a second wavelength, different from the first wavelength, the first light emitting diode being an organic light emitting diode constructed on the optically transparent substrate and the first light emitting diode being further constructed to emit the first and second lights in a direction through the transparent substrate;

a semiconductor substrate;

a second light emitting diode constructed on the semiconductor substrate to emit light of a third wavelength, different than the first and second wavelengths; and

an attachment area on the optically transparent substrate, the semiconductor substrate being attached to the attachment area wherein the second light emitting diode emits light in the same direction as the first light emitting diode and cooperates with the first light emitting diode to generate a pixel of the display.

8. The full color light emitting diode display of claim 7 wherein the attachment area is a plurality of mounting pads.

9. The full color light emitting diode display of claim 8 wherein the plurality of mounting pads attaches the semiconductor substrate to the optically transparent substrate, the plurality of mounting pads being one of conductive epoxy bumps or solder bumps.

10. The full color light emitting diode display of claim 7 wherein one of the first and second lights is green and the other of the first and second lights is blue.

11. The full color light emitting diode display of claim 7 wherein each of the first and second lights is emitted by first and second emitting areas respectively, the first light emitting area includes an optically transparent hole supply conductor, a first color organic layer positioned on the hole supply conductor, and a second color organic layer on the first color organic layer wherein the second color organic layer has a defined area for an electron supply conductor, the second light emitting area having a third color organic layer on a portion of the second color organic layer wherein the third color organic layer has a defined area for an electron supply conductor, and the first and second light emitting areas having an electron supply conductor on the area defined for the electron supply conductor.

12. The full color light emitting diode display of claim 7 wherein the optically transparent substrate is one of glass and transparent plastic.

13. A full color light emitting diode display comprising:

a semiconductor substrate having a first array of light emitting diodes that are semiconductor light emitting diodes;

an optically transparent substrate having a second array of organic light emitting diodes; and

an attachment area on the optically transparent substrate, the semiconductor substrate being attached to the attachment area wherein the first array of light emitting diodes cooperates with the second array of light emitting diodes to form an array of pixels of the full color light emitting diode display.

14. The full color light emitting diode display of claim 13 wherein each semiconductor light emitting diode of the first array of light emitting diodes includes a multi-wavelength semiconductor light emitting diode that emits a first wavelength of light and a second wavelength of light that is different than the first wavelength of light.

15. The full color light emitting diode display of claim 14 wherein each light emitting diode of the second array of light emitting diodes emits a third wavelength of light that is different than the first and second wavelengths of light.

16. The full color light emitting diode display of claim 13 wherein each semiconductor light emitting diode of the first array of light emitting diodes emits a first wavelength of light that includes visible light.

17. The full color light emitting diode display of claim 16 wherein each light emitting diode of the second array of light emitting diodes includes two organic light emitting areas wherein a first organic light emitting area emits a second wavelength of light that is different than the first wavelength of light, and a second organic light emitting area emits a third wavelength of light that is different than the first and second wavelengths of light.

18. The full color light emitting diode display of claim 17 wherein each organic light emitting area includes an optically transparent hole supply conductor, a first color organic layer positioned on the hole supply conductor, and a second color organic layer on the first color organic layer wherein the second color organic layer has a defined area for an electron supply conductor, a second light emitting area having a third color organic layer on a portion of the second color organic layer wherein the third color organic layer has a defined area for an electron supply conductor, and the first and second light emitting areas having an electron supply conductor on the area defined for the electron supply conductor.