LED display with wavelength conversion layer

• US 9,865,577 B2
• Filed: 02/21/2017
• Issued: 01/09/2018
• Est. Priority Date: 06/18/2013
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Bibl, Andreas, McGroddy, Kelly
• Primary Examiner(s): TRAN, MINH LOAN
• Application Number:
  US15/438,587
• Publication Number:
  US 20170162553A1
• Time in Patent Office: 322 Days
• Field of Search: None
• 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 conversion 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;

a first pixel of the array of pixels that includes a first subpixel designed for a first color emission spectrum, and a second subpixel designed for a second color emission spectrum different from the first color emission spectrum;

a first vertical light emitting diode (LED) mounted on a first bottom electrode within the first subpixel;

a second vertical LED mounted on a second bottom electrode within the second subpixel;

a sidewall passivation material that laterally surrounds the first and second vertical LEDs;

a top electrode layer that spans over the sidewall passivation layer material and the first and second vertical LEDs, and is in electrical contact with the first and second vertical LEDs;

a first wavelength conversion layer comprising phosphor particles over the top electrode layer and the first vertical LED, wherein the first wavelength conversion layer is not over the second vertical LED.

2. The display panel of claim 1, wherein the display substrate further comprises a terminal line, and the top electrode layer electrically connects the first vertical LED and the second vertical LED to the terminal line.

3. The display panel of claim 2, wherein the first and second vertical LEDs each have a maximum width of 1-100 um.

4. The display panel of claim 2, wherein the first vertical LED is mounted to the first bottom electrode within a bank opening.

5. The display panel of claim 4, wherein the first wavelength conversion layer completely covers the bank opening.

6. The display panel of claim 4, further comprising a reflective bank layer within the bank opening.

7. The display panel of claim 6, wherein the first wavelength conversion layer completely covers the bank opening.

8. The display panel of claim 6, wherein the reflective bank layer is the first bottom electrode.

9. The display panel of claim 4, wherein the second vertical LED is mounted to the second bottom electrode within a second bank opening.

10. The display panel of claim 9, further comprising a second reflective bank layer within the second bank opening.

11. The display panel of claim 2, further comprising a black matrix layer arranged between the first and second subpixels.

12. The display panel of claim 2, wherein the phosphor particles are quantum dots.

13. The display panel of claim 12, wherein the first wavelength conversion layer further comprises scattering particles.

14. The display panel of claim 1, further comprising a color filter over the first wavelength conversion layer, wherein the color filter is designed to filter out light emitted from the first vertical LED.

15. The display panel of claim 1, further comprising an array of controller chips in a pixel areas of the display substrate, each controller chip to switch and drive a corresponding plurality of vertical LEDs.

16. The display panel of claim 15, wherein the array of controller chips includes a first controller chip to switch and drive the first and second vertical LEDs.

17. The display panel of claim 1, wherein the first and second vertical LEDs are bonded to the first and second bottom electrodes with a solder material.

18. The display panel of claim 17, wherein each of the first and second vertical LEDs comprises a p-n diode, and a conformal dielectric barrier layer spanning sidewalls of the p-n diode.