FLEXIBLE TOUCH SENSOR WITH FINE PITCH INTERCONNECT

• US 20140299365A1
• Filed: 09/27/2012
• Published: 10/09/2014
• Est. Priority Date: 09/30/2011
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Sebastian, Muthu, Lennhoff, Nancy S., Travasso, Dominic M., Swartz, Steven T.
• Granted Patent: US 9,642,243 B2
• Time in Patent Office: Days
• US Class Current: 174/255
• CPC Class Codes: G06F 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
• 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
• CPC Class Codes: H05K 1/0274 Optical details, e.g. printed circuits comprising integral optical means H05K1/0269 takes precedence; coupling light guides with opto-electronic components G02B6/42
• CPC Class Codes: H05K 1/09 Use of materials for the conductive, e.g. metallic pattern
• CPC Class Codes: H05K 2201/0302 Properties and characteristics in general
• CPC Class Codes: H05K 2201/032 Materials
• CPC Class Codes: H05K 3/06 the conductive material being removed chemically or electrolytically, e.g. by photo-etch process semi-additive methods H05K3/108

Abstract

An article includes a multilayer structure, such as, e.g., a touch sensor, having two opposing sides and comprising a central polymeric UV transparent substrate, a transparent conductive layer on each of the two major opposing surfaces of the polymeric substrate, a metallic conductive layer on each transparent conductive layer, and a patterned photoimaging mask on each metallic conductive layer.

Claims

1. A method comprising:

providing a multilayer structure having two opposing sides and comprising a central polymeric UV transparent substrate having two major opposing surfaces, a transparent conductive layer on each of the two major opposing surfaces of the polymeric substrate, and a metallic conductive layer on each transparent conductive layer;

applying and patterning first photoimaging layers on both metallic conductive layers to form photoimaging masks having desired patterns for the transparent conductive layers;

etching the portions of the metallic conductive layers and transparent conductive layers exposed by the photoimaging masks;

removing the photoimaging masks;

applying and patterning second photoimaging layers over the remaining portions of each metallic conductive layer to form photoimaging masks having desired patterns for the metallic conductive layers; and

etching the exposed portions of the metallic conductive layers.

16. The method of claim 1, wherein the photoimaging layers on opposing sides of the multilayer structure are simultaneously exposed to UV light.

17. The method of claim 1, wherein the metallic conductive layers on opposing sides of the multilayer structure are etched simultaneously.

18. The method of claim 1, wherein the transparent conductive layers on opposing sides of the multilayer structure are etched simultaneously.

19. The method of claim 1, wherein the desired pattern for one or both of the metallic conductive layers comprises a circuit for connecting the transparent conductive layer to a device.

20. The method of claim 1, wherein the exposed portions of the metallic conductive layers are etched with an etchant that does not etch ITO.

2. A method comprising:

providing a multilayer structure having two opposing sides and comprising a central polymeric UV transparent substrate having two major opposing surfaces, a transparent conductive layer on each of the two major opposing surfaces of the polymeric substrate, and a metallic conductive layer on each transparent conductive layer;

applying and patterning first photoimaging layers on both metallic conductive layers to form photoimaging masks having desired patterns for the transparent conductive layers and the metallic conductive layers;

etching the portions of the metallic conductive layers and transparent conductive layers exposed by the photoimaging masks;

removing the photoimaging masks;

applying and patterning second photoimaging layers over the remaining portions of each metallic conductive layer to form photoimaging masks protecting the desired patterns of the metallic conductive layers; and

etching the exposed portions of the metallic conductive layers.

3. The method of claim 2, wherein the photoimaging layers on opposing sides of the multilayer structure are simultaneously exposed to UV light.

4. The method of claim 2, wherein the metallic conductive layers on opposing sides of the multilayer structure are etched simultaneously.

5. The method of claim 2, wherein the transparent conductive layers on opposing sides of the multilayer structure are etched simultaneously.

6. The method of claim 2, wherein the desired pattern for one or both of the metallic conductive layers comprises a circuit for connecting the transparent conductive layer to a device.

7. The method of claim 2, wherein the exposed portions of the metallic conductive layers are etched with an etchant that does not etch ITO.

8. An article comprising:

a multilayer structure having two opposing sides and comprising a central polymeric UV transparent substrate, a transparent conductive layer on each of the two major opposing surfaces of the polymeric substrate, and a metallic conductive layer on each transparent conductive layer.

9. The article of claim 8, wherein the multilayer structure further comprises a patterned photoimaging mask on each metallic conductive layer.

10. The article of claim 8, wherein both transparent conductive layers are patterned.

11. The article of claim 8, wherein the transparent conductive layer comprises indium tin oxide (ITO).

12. The article of claim 8, wherein the transparent conductive layer comprises layers of ITO and silicon oxide.

13. The article of claim 8, wherein the multilayer structure includes a non-touch-sensing area and at least one longitudinal connector tail extending from the non-touch-sensing area.

14. An article comprising:

a multilayer structure having two opposing sides and comprising a central polymeric UV transparent substrate having opposing major surfaces, and patterned transparent conductive layers on opposing major surfaces of the substrate, wherein the polymeric UV transparent substrate has a refractive index greater than about 1.60.

15. The article of claim 14 further comprising patterned metallic conductive layers on both transparent conductive layers.