Bonding electronic components to patterned nanowire transparent conductors

Patent metadata

Field	Value
Publication number	US-9980394-B2
Application number	US-201414897521-A
Country	US
Kind code	B2
Filing date	Jul 18, 2014
Priority date	Jul 31, 2013
Publication date	May 22, 2018
Grant date	May 22, 2018

Abstract

A method for making an electronic assembly includes applying a conductive adhesive to a resist layer overlying a patterned conductive nanowire layer on a substrate and engaging an electrical contact of an electronic component with the conductive adhesive to provide an electrical connection between the electronic component and the conductive nanowire layer.

First claim

The invention claimed is:

1. A method for making an electronic assembly, comprising:
applying a transfer tape to a resist layer overlying a patterned conductive nanowire layer on a substrate, wherein the transfer tape comprises a first side having thereon a first conductive adhesive layer contacting the resist layer, and a second side having thereon a second conductive adhesive layer, further wherein the first conductive adhesive layer comprises metal particles in an adhesive matrix; and
engaging an electrical contact of an electronic component with the first conductive adhesive layer to provide an electrical connection between the electronic component and the conductive nanowire layer.

2. The method of claim 1 , wherein the metal particles are selected from silver, gold, copper, aluminum, and combinations thereof.

3. The method of claim 1 , wherein the adhesive matrix of the first conductive adhesive layer comprises an acrylic pressure sensitive adhesive, a thermally bonded adhesive, or combinations thereof.

4. The method claim 1 , wherein the resist layer has a thickness of about 10 nanometers to about 300 nanometers.

5. The method of claim 1 , wherein the resist layer has a thickness of about 40 nanometers to about 200 nanometers.

6. The method of claim 1 , wherein the resist layer has a refractive index of about 1.30 to about 2.50.

7. The method of claim 1 , wherein the patterned conductive nanowire layer on the substrate is produced by:
coating a substrate with a conductive layer comprising nanowires;
applying a pattern on the conductive layer with a resist matrix material to generate on the substrate one or more first regions of exposed conductive layer and one or more second regions of resist matrix material;
hardening or curing the resist matrix material;
over coating the pattern with a strippable polymer layer;
hardening or curing the strippable polymer layer;
peeling the strippable polymer layer from the substrate; and
removing the exposed conductive layer from the substrate in the one or more first regions of the substrate to form a patterned conductive layer on the substrate, wherein the patterned conductive layer comprises nanowires overlain by the resist matrix material.

8. The method of claim 1 , wherein the patterned conductive nanowire layer on the substrate is produced by:
coating a substrate with a conductive layer comprising nanowires;
applying a pattern on the conductive layer with a strippable polymer liquid-forming layer to generate on the substrate one or more first regions of exposed conductive layer and one or more second regions covered with the strippable polymer liquid-forming layer;
hardening or curing the strippable polymer liquid-forming layer into a strippable polymer layer; and
peeling the strippable polymer layer from the substrate and removing portions of the conductive layer in the one or more second regions of the substrate to form a patterned conductive layer on the substrate.

9. An electronic assembly, comprising:
a substrate comprising thereon a pattern of conductive nanowires, wherein the conductive nanowires are overlain by a layer of a resist matrix material;
a transfer tape on the layer of resist matrix material, wherein the transfer tape comprises a first side having thereon a first conductive adhesive layer, and a second side having thereon a second conductive adhesive layer contacting the resist matrix material, further wherein the second conductive adhesive layer comprises metal particles in an adhesive matrix; and
an electrical contact of an electronic component in contact with the second conductive adhesive layer.

10. The electronic assembly of claim 9 , wherein the resist matrix material has a thickness of about 10 nanometers to about 300 nanometers.

11. The electronic assembly of claim 9 , wherein the resist matrix material has a thickness of about 40 nanometers to about 200 nanometers.

12. The electronic assembly of claim 9 , wherein the adhesive matrix comprises a pressure sensitive adhesive, a thermally bonded adhesive or combinations thereof.

13. The electronic assembly of claim 12 , wherein the first conductive adhesive layer is different from the second conductive adhesive layer.

14. The electronic assembly of claim 9 , wherein the metal particles comprise silver, gold, copper, aluminum and combinations thereof.

15. The electronic assembly of claim 9 , wherein the electronic component comprises a flexible circuit.

16. An electronic assembly made according to the process of claim 1 .

17. A touch screen display comprising:
a liquid crystal display;
an electronic assembly comprising:
a glass substrate on the liquid crystal display, wherein the glass substrate comprises thereon a pattern of conductive nanowires, wherein the conductive nanowires are overlain by a layer of a resist matrix material;
a transfer tape on the layer of resist matrix material, wherein the transfer tape comprises a first side having thereon a first conductive adhesive layer, and a second side having thereon a second conductive adhesive layer contacting the resist matrix material, further wherein the second conductive adhesive layer comprises metal particles in an adhesive matrix; and
an electrical contact of a flexible circuit in contact with the second conductive adhesive layer; and
a flexible transparent surface overlying the electronic assembly.

Assignees

• 3M Innovative Properties Co

Inventors

• Stay Matthew S
• Pekurovsky Mikhail L
• Dodds Shawn C
• Gilman Ann M
• Theis Daniel J

Classifications

• G06F3/041 Primary

  Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means · CPC title

• H05K1/0393

  Flexible materials (H05K1/038 takes precedence; specific organic compositions are classified in H05K1/0313 and subgroups) · CPC title

• H05K1/0296

  Conductive pattern lay-out details not covered by sub groups H05K1/02 - H05K1/0295 (H05K1/11 takes precedence; lay-out adapted to mounted component configuration H05K1/18) · 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

• H05K2201/10128

  Display · CPC title