LED DISPLAY WITH WAVELENGTH CONVERSION LAYER

• US 20140367633A1
• Filed: 06/18/2013
• Published: 12/18/2014
• Est. Priority Date: 06/18/2013
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: LuxVue Techonology Corporation (Apple Inc.)
• Inventors: Bibl, Andreas, McGroddy, Kelly
• Granted Patent: US 9,111,464 B2
• Time in Patent Office: Days
• US Class Current: 257/13
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133614 using photoluminescence, e.g. phosphors illuminated by UV or blue light
• CPC Class Codes: G02F 1/133617 Illumination with ultraviolet light; Luminescent elements or materials associated to the cell
• CPC Class Codes: G09F 9/00 Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements in which the variable information is permanently attached to a movable support G09F11/00; abacus G06C1/00; slide-rules G06G1/00
• CPC Class Codes: G09G 3/32 semiconductive, e.g. using light-emitting diodes [LED]
• CPC Class Codes: H01L 24/95 at chip-level, i.e. with connecting carried out on a plurality of singulated devices, i.e. on diced chips
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 25/167 comprising optoelectronic devices, e.g. LED, photodiodes
• 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 2924/12041 LED
• CPC Class Codes: H01L 2924/12042 LASER
• CPC Class Codes: H01L 2924/12044 OLED
• CPC Class Codes: H01L 33/38 with a particular shape
• CPC Class Codes: H01L 33/50 Wavelength conversion elements
• CPC Class Codes: H01L 33/501 characterised by the materials, e.g. binder
• CPC Class Codes: H01L 33/502 Wavelength conversion materials
• CPC Class Codes: H01L 33/504 Elements with two or more wavelength conversion materials
• CPC Class Codes: H01L 33/505 characterised by the shape, e.g. plate or foil
• CPC Class Codes: H01L 33/507 the elements being in intimate contact with parts other than the semiconductor body or integrated with parts other than the semiconductor body
• CPC Class Codes: H01L 33/52 : Encapsulations
• CPC Class Codes: H01L 33/54 : having a particular shape
• CPC Class Codes: H01L 33/56 : Materials, e.g. epoxy or silicone resin
• CPC Class Codes: H01L 33/58 : Optical field-shaping elements
• CPC Class Codes: H10K 50/86 : Arrangements for improving contrast, e.g. preventing reflection of ambient light
• CPC Class Codes: H10K 59/122 : Pixel-defining structures or layers, e.g. banks
• CPC Class Codes: H10K 59/38 : comprising colour filters or colour changing media [CCM]
• CPC Class Codes: H10K 59/8791 : Arrangements for improving contrast, e.g. preventing reflection of ambient light

Abstract

A display and method of manufacture are described. The display may include a substrate including an array of pixels with each pixel including multiple subpixels, and each subpixel within a pixel is designed for a different color emission spectrum. An array of micro LED device pairs are mounted within each subpixel to provide redundancy. An array of wavelength conversions layers comprising phosphor particles are formed over the array of micro LED device pairs for tunable color emission spectrum.

Claims

1. A display panel comprising:

a display substrate including an array of pixels, each pixel including multiple subpixels, with each of the subpixels designed for a different color emission spectrum;

an array of micro LED device pairs, wherein a pair of micro LED devices is mounted within each subpixel, and

an array of wavelength conversion layers comprising phosphor particles over the array of micro LED device pairs.

2. The display panel of claim 1, wherein the array of wavelength conversion layers comprises multiple groups of wavelength conversions layers, with each group designed to emit a different color emission spectrum, and the different groups of wavelength conversion layers are separated into different subpixels.

3. The display panel of claim 2, wherein a wavelength conversion layer is not formed over a micro LED device pair for one of the subpixels.

4. The display panel of claim 2, wherein the array of micro LED device pairs is designed to emit a single color emission spectrum.

5. The display panel of claim 1, wherein the array of micro LED device pairs includes groups of micro LED device pairs, with each group designed to emit a different color emission spectrum, and the different groups of micro LED device pairs are separated into different subpixels.

6. The display panel of claim 5, wherein a wavelength conversion layer is formed over a first group of micro LED device pairs in a first subpixel, and a wavelength conversion layer is not formed over a second group of micro LED device pairs in a second subpixel.

7. The display panel of claim 1, wherein each wavelength conversion layer is formed over a only a single micro LED device.

8. The display panel of claim 1, wherein each wavelength conversion layer is formed over a micro LED device pair.

9. The display panel of claim 1, wherein the wavelength conversion layers are dome shaped.

10. The display panel of claim 9, wherein the wavelength conversion layers have a shape selected from the group consisting of:

a hemispherical outer surface and elongated dome shaped.

11. The display panel of claim 1, further comprising an array of light distribution layers between the array of wavelength conversion layers and corresponding micro LED device pairs.

12. The display panel of claim 11, wherein the light distribution layers are light pipes, each light distribution layer is characterized with a lateral length that is greater than a thickness of the light distribution layer.

13. The display panel of claim 1, wherein the phosphor particles are quantum dots.

14. The display panel of claim 1, wherein the phosphor particles exhibit luminescence due to their composition that do not qualify as quantum dots.

15. The display panel of claim 1, wherein the micro LED devices each have a maximum width of 1 μ

m-100 μ

m.

16. The display panel of claim 1, further comprising a reflective bank layer corresponding to each subpixel, wherein each reflective bank layer is independently addressable from working circuitry within the display substrate.

17. The display panel of claim 1, further comprising a ground line on or within the display substrate.

18. The display panel of claim 17, further comprising one or more top electrode layers electrically connecting the array of micro LED device pairs to the ground line.

19. The display panel of claim 18, wherein the one or more top electrode layers comprise a first top electrode layer electrically connecting a first micro LED device of a micro LED device pair to the ground line, and a separate top electrode layer connecting a second micro LED device of the micro LED device pair to the ground line.

20. The display panel of claim 12, wherein each light distribution layer in the form of a light pipe spans over more than one subpixel and the micro LED device pairs mounted within the more than one subpixel.

21. The display panel of claim 12, wherein each light distribution layer in the form of a light pipe spans over all of the multiple subpixels within a corresponding pixel and the micro LED device pairs mounted within the multiple subpixels of the pixel.

22. The display panel of claim 12, wherein each light distribution layer in the form of a light pipe spans over no more than one subpixel and the micro LED device pairs mounted within the subpixel.