Flexible displays

Patent metadata

Field	Value
Publication number	US-9419065-B2
Application number	US-201313932834-A
Country	US
Kind code	B2
Filing date	Jul 1, 2013
Priority date	Aug 7, 2012
Publication date	Aug 16, 2016
Grant date	Aug 16, 2016

Abstract

An electronic device may be provided with an organic light-emitting diode display with minimized border regions. The border regions may be minimized by providing the display with bent edge portions having neutral plane adjustment features that facilitate bending of the bent edge portions while minimizing damage to the bent edge portions. The neutral plane adjustment features may include a modified backfilm layer of the display in which portions of the backfilm layer are removed in a bend region. A display device may include a substrate, a display panel on the substrate having display pixels, and peripheral circuitry proximate the display panel and configured to drive the display pixels. A portion of the periphery of the substrate may be bent substantially orthogonal to the display panel to reduce an apparent surface area of the display device. The bent portion may include an electrode for communication with the peripheral circuitry.

First claim

What is claimed is:

1. A display, comprising:
a first polymer layer with an active area that contains an array of thin-film transistors and an inactive area that includes at least one bent edge portions of the first polymer layer; and
a second polymer layer attached to the first polymer layer, wherein the second polymer layer includes at least one neutral plane adjustment feature that facilitates bending of the bend edge portion of the first polymer layer, wherein the second polymer layer comprises first and second portions, wherein the neutral plane adjustment feature is formed from a gap between the first and second portion, and wherein the gap in the second polymer layer exposes the first polymer layer.

2. The display defined in claim 1 wherein the first polymer layer comprises polyimide.

3. The display defined in claim 2 wherein the second polymer layer comprises polyethylene terephthalate.

4. The display defined in claim 1 wherein the bent edge portion of the first polymer layer extends beyond an edge of the second polymer layer and bends around the edge of the second polymer layer.

5. The display defined in claim 1 wherein the gap extends along at least some of the bent edge portions of the first polymer layer.

6. The display defined in claim 1 wherein the first portion of the second polymer layer is attached to the first polymer layer in the active area and the second portion of the second polymer layer is attached to the bent edge portion of the first polymer layer.

7. The display defined in claim 1 , further comprising:
conductive traces on the first polymer layer that extend from the active area over the bent edge portion, wherein each conductive trace splits into multiple sub-traces on the bent edge portion of the first polymer layer.

8. The display defined in claim 7 wherein the multiple sub-traces of each conductive trace comprise at least four sub-traces.

9. A method of forming an organic light-emitting diode display, comprising:
forming display structures including an array of thin-film transistors on an active area of a polymer substrate that is attached to a glass carrier substrate;
attaching an integrated circuit to an inactive area of the polymer substrate;
removing the glass carrier substrate;
attaching a polymer backfilm layer to the polymer substrate; and
bending an edge region of the polymer substrate in the inactive area, wherein the edge region of the polymer substrate is adjacent to a neutral plane adjustment feature in the polymer backfilm layer, wherein the polymer backfilm layer comprises first and second portions, wherein the neutral plane adjustment feature is formed from a gap between the first and second portions, and wherein the gap in the polymer backfilm layer exposes the polymer substrate.

10. The method defined in claim 9 , further comprising:
removing at least some of the polymer backfilm layer that has been attached to the polymer substrate to form the gap.

11. The method defined in claim 10 wherein removing the at least some of the polymer backfilm layer that has been attached to the polymer substrate comprises cutting the polymer backfilm layer along the edge region of the polymer substrate.

12. The method defined in claim 9 wherein attaching the polymer backfilm layer to the polymer substrate comprises attaching a pre-cut polymer backfilm layer having the neutral plane adjustment feature to the polymer substrate.

13. A display device with a reduced border region, comprising:
a polymer substrate having an active area and an inactive area;
a plurality of display pixel and an array of thin-film transistors in the active area of the polymer substrate;
peripheral circuitry in the inactive area of the polymer substrate that is proximate to the display panel and that is configured to drive the plurality of display pixels; and
a flexible polymer carrier attached to the polymer substrate, wherein a portion of the polymer substrate in the inactive area and a portion of the flexible polymer carrier are bent substantially orthogonal to the display pixels, wherein the flexible polymer carrier comprises first and second portions wherein a bend region of the flexible polymer, and wherein the gap in the flexible polymer carrier exposes the polymer substrate.

14. The display device defined in claim 13 , further comprising:
at least one electrode coupled to the peripheral circuitry, wherein a bend region of the polymer substrate includes a portion of the at least one electrode.

15. The display device defined in claim 14 wherein the peripheral circuitry comprises a first component and a second component and wherein the portion of the at least one electrode comprises a bent electrical interconnection between the first component and the second component.

16. The display device defined in claim 15 wherein the bent electrical interconnection is configured to conduct display communication signals between the first component and the second component.

17. The display device defined in claim 14 wherein the portion of the at least one electrode in the bend region of the polymer substrate is arranged in a pattern selected from the group consisting of a waving pattern, a sinusoidal pattern, an alternating pattern, and a disruptive planar pattern.

18. The display device defined in claim 14 wherein the at least one electrode includes an additional portion that is located outside the bend region of the polymer substrate, wherein the portion of the at least one electrode is formed from a flexible conductor, and wherein the additional portion of the at least one electrode is formed from a conductive material that is different from the flexible conductor.

19. The display device defined in claim 14 wherein the at least one electrode includes an additional portion that is located outside the bend region of the polymer substrate, wherein the portion of the at least one electrode has a bend thickness, and wherein the additional portion of the at least one electrode has a thickness that is greater than the bend thickness.

20. The display device defined in claim 14 wherein the at least one electrode includes an additional portion that is located outside the bend region of the polymer substrate, wherein the portion of the at least one electrode has a bend thickness, and wherein the additional portion of the at least one electrode has a thickness that is less than the bend thickness.

21. The display device defined in claim 14 , further comprising:
conductive material that is suspended in an adhesive film that fills surface imperfections in an outer surface of the portion of the at least one electrode.

22. A method of forming a display, comprising:
identifying a bend region on a flexible carrier substrate comprising polymer;
forming a gap in the flexible carrier substrate in the bend region such that the gap separates a first portion and a second portion of the flexible carrier substrate;
attaching the flexible carrier substrate to display layers, wherein the display layers comprise at least one an array of thin-film transistors in the active area; and
bending the flexible carrier substrate and at least some of the attached display layers in the bend region, wherein the bend region of the flexible carrier substrate overlaps the inactive area of the polymer substrate, and wherein the gap in the flexible carrier substrate exposes the polymer substrate.

23. The method defined in claim 22 , further comprising:
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Assignees

• Apple Inc

Inventors

• Degner Brett W
• Chen Chieh-Wei
• Mathew Dinesh C
• Drzaic Paul S
• Kim Sang Ha
• Grespan Silvio
• Zhong John Z
• Guillou Jean-Pierre
• Sung Kuo-Hua
• Park Young Bae
• Gupta Vasudha

Classifications

• H05K2201/0979

  Redundant conductors or connections, i.e. more than one current path between two points · CPC title

• G02F2001/133388

  Physics · mapped topic

• H05K2201/09036

  Recesses or grooves in insulating substrate · CPC title

• H01L27/326 Primary

  Electricity · mapped topic

• H05K1/189

  characterised by the use of flexible or folded printed circuits · CPC title