Electrode pattern, manufacturing method thereof, and touch sensor including the same

• US 10,126,886 B2
• Filed: 05/15/2015
• Issued: 11/13/2018
• Est. Priority Date: 12/11/2014
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Choi, Shin Il, Kim, Jae Neung, Bae, Su Bin, Jeong, Yu-Gwang
• Primary Examiner(s): Sadio, Insa
• Application Number:
  US14/712,953
• Publication Number:
  US 20160170521A1
• Time in Patent Office: 1,278 Days
• CPC Class Codes: G06F 2203/04103 Manufacturing, i.e. details related to manufacturing processes specially suited for touch sensitive devices
• CPC Class Codes: G06F 2203/04111 Cross over in capacitive digitiser, i.e. details of structures for connecting electrodes of the sensing pattern where the connections cross each other, e.g. bridge structures comprising an insulating layer, or vias through substrate
• CPC Class Codes: G06F 2203/04112 Electrode mesh in capacitive digitiser: electrode for touch sensing is formed of a mesh of very fine, normally metallic, interconnected lines that are almost invisible to see. This provides a quite large but transparent electrode surface, without need for ITO or similar transparent conductive material
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes

Abstract

A transparent electrode pattern includes a first electrode including a first lower conductive layer and a first upper conductive layer located on the first lower conductive layer and a second electrode spaced apart from the first electrode and including a second lower conductive layer and a second upper conductive layer positioned on the second lower conductive layer. The first and second lower conductive layers may include a metal nanowire. The first and second upper conductive layers may include a transparent conductive material that is dry-etchable.

Claims

1. A transparent electrode pattern, comprising:

a first electrode and a second electrode spaced apart from one another laterally on a substrate, the first electrode and the second electrode each being formed on a same plane, wherein;

the first electrode includes a first lower conductive layer on the substrate and a first upper conductive layer on the first lower conductive layer; and

the second electrode including a second lower conductive layer on the substrate and a second upper conductive layer on the second lower conductive layer,

the first lower conductive layer, the first upper conductive layer, the second lower conductive layer and the second upper conductive layer are transparent layers,

the first and second lower conductive layers each include a metal nanowire and an overcoat, a first portion of the overcoat extending laterally beyond the metal nanowire into a space between the first electrode and the second electrode, and

the first and second upper conductive layers include a transparent conductive material that is dry-etchable.

2. The transparent electrode pattern as claimed in claim 1, wherein:

the first and second upper conductive layers include GTO (gallium tin oxide).

3. The transparent electrode pattern as claimed in claim 2, wherein:

a first edge of the first lower conductive layer and a first edge of the first upper conductive layer are substantially aligned, the metal nanowire of the first lower conductive layer not extending beyond the first edge into the first portion of the overcoat, and

a second edge of the second lower conductive layer and a second edge of the second upper conductive layer are substantially aligned, the metal nanowire of the second lower conductive layer not extending beyond the second edge into the first portion of the overcoat.

4. The transparent electrode pattern as claimed in claim 1, wherein:

the first portion overcoat that extends to be positioned between the first lower conductive layer and the second lower conductive layer is in direct contact with the substrate.

5. A method for manufacturing a transparent electrode pattern, the method comprising:

forming a lower conductive layer including a metal nanowire and an overcoat on a same plane of a substrate, the lower conductive layer being transparent;

forming a photosensitive film pattern on the lower conductive layer;

reflowing the photosensitive film pattern to form an undercut structure;

depositing a transparent conductive material on the photosensitive film pattern and the lower conductive layer to form an upper conductive layer;

stripping the photosensitive film pattern and lifting off the upper conductive layer positioned on the photosensitive film pattern to form a first upper conductive layer and a second upper conductive layer that are separated from each other;

plasma treating an upper face of the first and second upper conductive layers and the lower conductive layer with a plasma gas, thereby forming a metal compound combined with the overcoat in a first region of the lower conductive layer that is not covered by the first and second upper conductive layers; and

selectively removing the metal compound from the overcoat in the first region such that a first portion of the overcoat remains in the first region between the first and second upper conductive layers.

6. The method as claimed in claim 5, wherein:

the plasma gas includes chlorine (Cl) or bromine (Br).

7. A touch sensor, comprising:

a plurality of touch electrodes, the plurality of touch electrodes including a first electrode and a second electrode spaced apart from one another laterally on a substrate, the first electrode and the second electrode each being formed on a same plane, wherein;

the first electrode includes including a transparent first lower conductive layer on the substrate and a transparent first upper conductive layer on the first lower conductive layer; and

the second electrode includes a transparent second lower conductive layer on the substrate and a transparent second upper conductive layer on the second lower conductive layer,

wherein the first and second lower conductive layers each include a metal nanowire and an overcoat, a first portion of the overcoat extending laterally beyond the metal nanowire into a space between the first electrode and the second electrode, and

the first and second upper conductive layers include a transparent conductive material that is dry-etchable.

8. The touch sensor as claimed in claim 7, wherein:

the first and second upper conductive layers include GTO (gallium tin oxide).

9. A touch sensor, comprising a plurality of touch electrodes, the plurality of touch electrodes including:

a first electrode including a transparent first lower conductive layer and a transparent first upper conductive layer positioned on the first lower conductive layer; and

a second electrode spaced apart from the first electrode and including a transparent second lower conductive layer and a transparent second upper conductive layer positioned on the second lower conductive layer,

wherein;

the first and second lower conductive layers include a metal nanowire wherein the first and second lower conductive layers further include an overcoat, the overcoat extending to be positioned between the first lower conductive layer and the second lower conductive layer, and the metal nanowire being at least partially removed between the first lower conductive layer and the second lower conductive layer,

the first and second upper conductive layers include a transparent conductive material, and

a plasma gas composition including chlorine (Cl) or bromine (Br) is present on a surface of the first and second upper conductive layers.

10. The touch sensor as claimed in claim 9, wherein:

an edge of the first lower conductive layer and an edge of the first upper conductive layer are substantially aligned, and

an edge of the second lower conductive layer and an edge of the second upper conductive layer are substantially aligned.