Wearable display having an array of LEDs on a conformable silicon substrate

• US 9,478,583 B2
• Filed: 12/08/2014
• Issued: 10/25/2016
• Est. Priority Date: 12/08/2014
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Hu, Hsin-Hua, Bibl, Andreas
• Primary Examiner(s): Jung, Michael
• Application Number:
  US14/563,772
• Publication Number:
  US 20160163765A1
• Time in Patent Office: 687 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: H01L 2224/24 of an individual high density interconnect connector
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 27/156 two-dimensional arrays
• CPC Class Codes: H01L 2933/0025 relating to coatings
• CPC Class Codes: H01L 2933/0033 relating to semiconductor body packages
• CPC Class Codes: H01L 2933/0066 relating to arrangements for conducting electric current to or from the semiconductor body
• 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 33/62 Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls
• CPC Class Codes: H10K 2102/311 Flexible OLED
• CPC Class Codes: H10K 77/111 Flexible substrates
• CPC Class Codes: Y02E 10/549 Organic PV cells
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

A conformable electronic device and methods for forming such devices are described. Embodiments of a conformable electronic device may include a silicon substrate having a thickness of 50 μm or less. An array of LEDs that are electrically coupled to a controller chip may be formed on a surface of the silicon substrate. In an embodiment, a top passivation layer is formed over the array of LEDs, the one or more controller chips, and the top surface of the silicon substrate. An embodiment also includes a bottom passivation layer formed on a bottom surface of the silicon substrate.

Claims

1. A conformable electronic device comprising:

a silicon substrate having a thickness between 5 and 50 μ

m;

an array of LEDs and an array of controller chips bonded to a first side of the silicon substrate, wherein each LED is electrically coupled to a controller chip;

one or more vias formed through the silicon substrate, wherein the one or more vias electrically couple one or more of the controller chips to the second side of the silicon substrate opposite to the first side;

a first passivation layer formed over the array of LEDs, the array of controller chips, and the first side of the silicon substrate; and

a second passivation layer formed over a second side of the silicon substrate opposite to the first side of the silicon substrate.

2. The conformable electronic device of claim 1, wherein the array of LEDs is bonded to the first side of the silicon substrate within an array of bank structures formed in the silicon substrate.

3. The conformable electronic device of claim 1, wherein each controller chip comprises a driving circuit to switch and drive one or more of the LEDs in the array of LEDs.

4. The conformable electronic device of claim 1, wherein the array of LEDs and the array of controller chips are within a display area of the conformable electronic device.

5. The conformable electronic device of claim 1, wherein the first passivation layer is transparent to the visible wavelength spectrum.

6. The conformable electronic device of claim 1, wherein the controller chips in the array of controller chips each control one or more pixels.

7. The conformable electronic device of claim 1, wherein the array of LEDs is ordered to form a plurality of pixels, wherein each pixel comprises one or more LEDs and wherein the plurality of pixels are formed at a density of 40 to 440 pixels per inch (PPI).

8. The conformable electronic device of claim 1, wherein the controller chips in the array of controller chips and the LEDs in the array of LEDs have a maximum length and width dimension of 1 to 300 μ

m.

9. The conformable electronic device of claim 1, wherein the thickness of the silicon substrate is between 5 and 20 μ

m.

10. The conformable electronic device of claim 1, further comprising a driver ledge formed around a display area, wherein one or more display components are bonded to the silicon substrate on the driver ledge and are electrically coupled to one or more of the controller chips.

11. The conformable electronic device of claim 1, wherein one or more display components are bonded to the second side of the silicon substrate and are electrically coupled to one or more of the controller chips.

12. The conformable electronic device of claim 1, wherein the first passivation layer and the second passivation layer are made of a same material.