MICRO-TRANSFER-PRINTED LIGHT-EMITTING DIODE DEVICE

• US 20170352646A1
• Filed: 05/30/2017
• Published: 12/07/2017
• Est. Priority Date: 06/01/2016
• Status: Active Grant

• Current Assignee: X Display Company Technology Limited (Sensinnovat BVBA)
• Original Assignee: X-Celeprint Limited
• Inventors: Bower, Christopher, Cok, Ronald S.
• Granted Patent: US 9,997,501 B2
• Time in Patent Office: Days
• CPC Class Codes: H01L 2224/18 High density interconnect [HDI] connectors; Manufacturing methods related thereto
• 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 27/1214 comprising a plurality of TFTs formed on a non-semiconducting substrate, e.g. driving circuits for AMLCDs
• CPC Class Codes: H01L 2933/0033 relating to semiconductor body packages
• CPC Class Codes: H01L 2933/0066 relating to arrangements for conducting electric current to or from the semiconductor body
• 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

A compound light-emitting diode (LED) device includes a semiconductor substrate having an active electronic circuit formed in or on the semiconductor substrate. Two or more electrically conductive circuit connection pads are formed in or on the semiconductor substrate and are electrically connected to the active electronic circuit. One or more micro-transfer printed LEDs each have at least two LED electrodes or connection pads and a fractured LED tether. An adhesive layer is disposed between the semiconductor substrate and each LED to adhere the semiconductor substrate to the LED. Two or more electrical conductors electrically connect one of the electrodes or LED connection pads to one of the circuit connection pads.

Claims

1. A compound light-emitting diode (LED) device, comprising:

a semiconductor substrate having an active electronic circuit formed in or on the semiconductor substrate;

two or more electrically conductive circuit connection pads formed in or on the semiconductor substrate, the active electronic circuit electrically connected to the two or more circuit connection pads;

one or more LEDs, each LED having at least two LED electrodes or connection pads and a fractured LED tether;

an adhesive layer disposed between the semiconductor substrate and each LED, wherein each LED is micro-transfer printed on the adhesive layer and the adhesive layer adheres the semiconductor substrate to the LED; and

two or more electrical conductors, each electrical conductor electrically connecting one of the electrodes or LED connection pads to one of the circuit connection pads.

2. The compound LED device of claim 1, wherein the active electronic circuit is located at least partially between the LED and the semiconductor substrate.

3. The compound LED device of claim 1, wherein the LED has an opposite side that is opposite the semiconductor substrate and at least two of the LED connection pads are located on the opposite side.

4. The compound LED device of claim 1, wherein the LED has an adjacent side that is adjacent to the semiconductor substrate and at least two of the LED connection pads are located on the adjacent side.

5. The compound LED device of claim 1, wherein the LED has an opposite side opposite the semiconductor substrate and an adjacent side adjacent to the semiconductor substrate and at least one of the LED connection pads is located on the adjacent side and at least one of the LED connection pads is located on the opposite side.

6. The compound LED device of claim 1, wherein the active electronic circuit is a control circuit that controls the one or more LEDs.

7. The compound LED device of claim 1, comprising three LEDs, each LED having a different material, crystalline structure, or color of light emission.

8. The compound LED device of claim 1, comprising a plurality of groups of three different LEDs, the groups arranged in an array over the semiconductor substrate.

9. The compound LED device of claim 1, wherein the active electronic circuit is an active-matrix circuit.

10. The compound LED device of claim 1, wherein the semiconductor substrate is a silicon substrate and each LED includes a compound semiconductor.

11. The compound LED device of claim 1, comprising two or more connection posts, each connection post electrically connected to a circuit connection pad or an LED connection pad.

12. The compound LED device of claim 1, wherein the semiconductor substrate is a display substrate and the one or more LEDs form a display.

13. The compound LED device of claim 12, wherein the display is a color display.

14. The compound LED device of claim 1, wherein each LED is directly or indirectly adhered to the semiconductor substrate with an adhesive layer.

15. The compound LED device of claim 14 wherein the adhesive is a cured adhesive.

16. The compound LED device of claim 9, wherein the semiconductor substrate has a process side, the electronic circuit is formed on or in the process side, and the LED is micro-transfer printed on the process side.

17. The compound LED device of claim 1, wherein the semiconductor substrate or one or more LEDs has at least one of a width from 2 to 5 μ

m, 5 to 10 μ

m, 10 to 20 μ

m, or 20 to 50 μ

m, a length from 2 to 5 μ

m, 5 to 10 μ

m, 10 to 20 μ

m, or 20 to 50 μ

m, and a height from 2 to 5 μ

m, 4 to 10 μ

m, 10 to 20 μ

m, or 20 to 50 μ

m.

18. The compound LED device of claim 1, comprising a reflective structure around each LED that reflects light emitted by the LED out of the compound LED device.

19. A method of making a compound light-emitting diode (LED) device, comprising:

providing a semiconductor substrate having an active electronic circuit formed in or on the semiconductor substrate and two or more electrically conductive circuit connection pads formed on the semiconductor substrate, the active electronic circuit electrically connected to the two or more circuit connection pads;

providing one or more LEDs, each LED having at least two LED connection pads and a fractured LED tether;

disposing an adhesive layer between the semiconductor substrate and each LED;

disposing each LED on the adhesive layer and the adhesive layer adheres the semiconductor substrate to the LED; and

forming two or more electrical conductors, each electrical conductor electrically connecting one of the LED connection pads to one of the circuit connection pads.

20. The method of claim 19, comprising micro-transfer printing the one or more LEDs from a source wafer to the semiconductor substrate.