Method for integrating a light emitting device

• US 9,876,000 B2
• Filed: 01/12/2017
• Issued: 01/23/2018
• Est. Priority Date: 06/17/2013
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Bibl, Andreas, Griggs, Charles R.
• Primary Examiner(s): Schoenholtz, Joseph
• Application Number:
  US15/405,060
• Publication Number:
  US 20170125392A1
• Time in Patent Office: 376 Days
• Field of Search: None
• 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 25/165 Containers
• CPC Class Codes: H01L 25/167 comprising optoelectronic devices, e.g. LED, photodiodes
• CPC Class Codes: H01L 27/0203 Particular design considerations for integrated circuits
• CPC Class Codes: H01L 27/124 with a particular composition, shape or layout of the wiring layers specially adapted to the circuit arrangement, e.g. scanning lines in LCD pixel circuits wiring structures per se H01L23/52
• CPC Class Codes: H01L 27/1244 for preventing breakage, peeling or short circuiting
• 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 2933/0025 relating to coatings
• CPC Class Codes: H01L 2933/0033 relating to semiconductor body packages
• CPC Class Codes: H01L 2933/005 relating to encapsulations
• CPC Class Codes: H01L 2933/0066 relating to arrangements for conducting electric current to or from the semiconductor body
• CPC Class Codes: H01L 33/0008 having p-n or hi-lo junctions
• CPC Class Codes: H01L 33/06 within the light emitting region, e.g. quantum confinement structure or tunnel barrier
• CPC Class Codes: H01L 33/08 with a plurality of light emitting regions, e.g. laterally discontinuous light emitting layer or photoluminescent region integrated within the semiconductor body H01L27/15 takes precedence
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/30 : containing only elements of Group III and Group V of the Periodic Table
• CPC Class Codes: H01L 33/44 : characterised by the coatings, e.g. passivation layer or anti-reflective coating
• CPC Class Codes: H01L 33/486 : adapted for surface mounting
• 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 33/60 : Reflective elements
• CPC Class Codes: H01L 33/62 : Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls

Abstract

Light emitting devices and methods of integrating micro LED devices into light emitting device are described. In an embodiment a light emitting device includes a reflective bank structure within a bank layer, and a conductive line atop the bank layer and elevated above the reflective bank structure. A micro LED device is within the reflective bank structure and a passivation layer is over the bank layer and laterally around the micro LED device within the reflective bank structure. A portion of the micro LED device and a conductive line atop the bank layer protrude above a top surface of the passivation layer.

Claims

1. A light emitting device comprising:

a substrate;

a bank layer over the substrate, the bank layer including a sidewall;

a bottom electrode layer on the substrate, and running along the sidewall of the bank layer and atop the bank layer;

an LED device bonded to the bottom electrode layer;

a conductive line atop the bank layer;

a passivation layer spanning over the substrate and the bank layer, the passivation layer laterally surrounding the LED device and including a top surface;

a first recess in the top surface of the passivation layer that exposes the conductive line atop the bank layer; and

a top electrode layer that spans directly over the LED device, the passivation layer, and within the first recess in the passivation layer such that the top electrode layer is in electrical contact with the conductive line atop the bank layer.

2. The light emitting device of claim 1, further comprising a second recess in the top surface of the passivation layer that exposes the LED device, wherein the top electrode layer spans within the second recess in the passivation layer such that the top electrode layer is in electrical contact with the LED device.

3. The light emitting device of claim 2, wherein the passivation layer comprises a thermoset material.

4. The light emitting device of claim 3, wherein the thermoset material is an acrylic.

5. The light emitting device of claim 2, wherein the LED device comprises p-n diode between a bottom contact and a top contact.

6. The light emitting device of claim 5, wherein the LED device further comprises an LED bonding layer below the bottom contact.

7. The light emitting device of claim 6, wherein the LED bonding layer is diffused with a substrate bonding layer on the bottom electrode layer to form an inter-metallic compound.

8. The light emitting device of claim 7, wherein the LED bonding layer is characterized by a higher liquidus temperature than the substrate bonding layer, and the intermetallic compound is characterized by a higher liquidus temperature than both the LED bonding layer and the substrate bonding layer.

9. The light emitting device of claim 5, further comprising a dielectric barrier layer along sidewalls of the p-n diode.

10. The light emitting device of claim 2, further comprising an integrated circuit interconnected with the bottom electrode layer.

11. The light emitting device of claim 10, wherein the substrate is a thin film transistor substrate.

12. The light emitting device of claim 2, wherein the bottom electrode layer comprises a reflective metallic film.

13. The light emitting device of claim 2, wherein the bottom electrode layer and the conductive line are formed of a same metallic film.

14. The light emitting device of claim 2, further comprising a cover layer over the top electrode layer.

15. The light emitting device of claim 14, wherein the cover layer is a conformal layer.

16. The light emitting device of claim 15, wherein the cover layer is transparent.

17. The light emitting device of claim 2, wherein the conductive line is a Vss line.

18. The light emitting device of claim 2, wherein the bank layer comprises metal oxide particles.

19. The light emitting device of claim 2, wherein the light emitting device is a display panel in a display system.

20. The light emitting device of claim 2, wherein the light emitting device is a light source in a lighting system.