Khanh Cong Le

US Patent:

20120019475, Jan 26, 2012

Filed:

Jul 26, 2010

Appl. No.:

12/843201

Inventors:

Jeffrey Li - Palo Alto CA, US
Paul P. Campbell - San Jose CA, US
Khanh M. Le - Morgan Hill CA, US
David M. Holmes - Cupertino CA, US

International Classification:

G06F 3/044
G01R 27/26

US Classification:

345174, 324686

Abstract:

A capacitive touch sensor has a clear top plastic film and graphics or other designs disposed on its reverse side. Only the bare plastic substrate is exposed to the environment and user wear. Non-conductive color inks are used in printing the graphics so that any printed capacitive sensors in contact behind will not be short circuited or desensitized. A silk-screened base color layer with a print-free margin left all around its edges allows a later application of adhesive to grip a more durable surface underneath. Capacitive touch sensors are deposited on a bottom plastic film with silvered conductive inks. The printed capacitive sensors on film are fastened with a silk-screen applied liquid water-based adhesive and face the graphics printed side of the first plastic film. A final overcoat of adhesive is applied to the bare backside of the bottom plastic film for final assembly to a frame or chassis.