Transparent conductive films with embedded metal grids

Patent metadata

Field	Value
Publication number	US-2016345430-A1
Application number	US-201615097919-A
Country	US
Kind code	A1
Filing date	Apr 13, 2016
Priority date	May 22, 2015
Publication date	Nov 24, 2016
Grant date	—

Abstract

A transparent conductive film with a metal mesh embedded in a substrate and a method of fabrication thereof is provided. The metal mesh has a cap that is pressed and embedded in a substrate or a deformable material on a substrate, providing superior mechanical stability by mechanical interlocking. The embedding mechanism also provides superior chemical and environmental stability. A fabrication method is provided and includes a vacuum-free and low-cost process for large-volume manufacturing of the transparent conductive film with tunable performance.

First claim

What is claimed is:

1 . A transparent conductive film, comprising:
a transparent substrate; and a metal mesh embedded in the transparent substrate, wherein the metal mesh has a cap that is embedded in the substrate.

2 . The transparent conductive film according to claim 1 , wherein the transparent substrate is a flexible plastic film.

3 . The transparent conductive film according to claim 1 , further comprising a rigid glass panel on which the transparent substrate is disposed.

4 . The transparent conductive film according to claim 2 , wherein the cap has a rounded button-like shape.

5 . The transparent conductive film according to claim 1 , wherein the metal mesh has an exposed side, which is not covered by the transparent substrate.

6 . The transparent conductive film according to claim 1 , wherein the transparent substrate is an ultraviolet light curable material.

7 . The transparent conductive film according to claim 1 , wherein the metal grid lines have a linewidth between 100 nm and 5000 nm, a grid opening size between 1 μm and 100 μm, and the ratio between the grid opening and the linewidth is between 5 and 100.

8 . The transparent conductive film according to claim 1 , wherein the metal mesh is tapered in a direction that is opposite the cap.

9 . The transparent conductive film according to claim 1 , wherein a linewidth of the metal grid gradually increases going away from the cap.

10 . The transparent conductive film according to claim 1 , wherein a side of the metal grid is flush with the transparent substrate.

11 . The transparent conductive film according to claim 1 , wherein a height of the metal grid is from 0.3 to 3 times its linewidth.

12 . The transparent conductive film according to claim 1 , wherein the metal grid is made of one of copper, gold, silver, nickel, zinc, tin, and alloy of any of these metals.

13 . A method for making the transparent conductive film of claim 1 , comprising:
preparing a first substrate; preparing a layer of dissolvable resist on the first substrate; creating a grid pattern in the resist layer by a lithography method, forming a trench grid network and exposing the first substrate through the trench; placing the first substrate in an electroplating bath and conducting electrodeposition of a metal into the grid pattern; ceasing electrodeposition when the metal reaches a sufficient thickness or is overplated out of the trench; dissolving the resist layer; covering the first substrate with a second substrate having a deformable surface layer; and pressing the metal grid on the first substrate into the second substrate and then solidifying the second substrate.

14 . The method of claim 13 , wherein the first substrate is fluorine-doped tin oxide (FTO)-coated glass.

15 . The method of claim 13 , wherein the lithography method used to create the metal grid patterns is one of photolithography, nanoimprint lithography, and e-beam lithography.

16 . The method of claim 13 , further comprising separating the second substrate from the first substrate with the metal grid peeled off and transferred to be embedded in the second substrate.

17 . The method of claim 13 , wherein the solidifying of the second substrate includes cooling or ultra-violet light curing.

18 . A transparent conductive film, comprising:
a transparent substrate; and a metal mesh that is embedded in the transparent substrate, wherein the metal mesh has a portion that is suitable for anchoring the metal mesh in the substrate.

19 . The transparent conductive film of claim 18 , wherein the metal mesh has an exposed surface.

20 . The transparent conductive film of claim 18 , wherein a linewidth of the mesh decreases going towards the exposed surface.

Assignees

• Versitech Ltd

Inventors

• Khan Arshad
• Li Wendi

Classifications

• H01B1/02

  mainly consisting of metals or alloys · CPC title

• G06F2203/04112

  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 title

• C25D1/04

  Wires; Strips; Foils · CPC title

• G06F2203/04103

  Manufacturing, i.e. details related to manufacturing processes specially suited for touch sensitive devices · CPC title

• C25D5/48

  After-treatment of electroplated surfaces · CPC title