Touch screen stack-up processing

Abstract

A multi-touch sensor panel is disclosed that can be produced by forming a plurality of first traces of substantially transparent conductive material on a first substrate, forming a plurality of second traces of the substantially transparent material, and creating a fluid-tight gap between the plurality of first traces and the plurality of second traces. The fluid-tight gap can then be filled with a fluid having substantially no bubbles and an optical index similar to the optical index of the first and second traces to make the gap and the first and second traces substantially transparent. The second and first traces can be oriented to cross over each other at crossover locations separated by the fluid, the crossover locations forming mutual capacitance sensors for detecting touches.

1 . A method for forming a multi-touch sensor panel, comprising:
 forming a plurality of first traces of substantially transparent conductive material on a first substrate;   forming a plurality of second traces of the substantially transparent material;   creating a fluid-tight gap between the plurality of first traces and the plurality of second traces;   filling the fluid-tight gap with a fluid having substantially no bubbles and an optical index similar to the optical index of the first and second traces to make the gap and the first and second traces substantially transparent; and   orienting the second and first traces to cross over each other at crossover locations separated by the fluid, the crossover locations forming mutual capacitance sensors for detecting touches.   
   
   
       2 . The method of  claim 1 , wherein the first substrate is a cover glass having a first side capable of being touched, and a second side opposite the first side on which the plurality of first traces are formed. 
   
   
       3 . The method of  claim 2 , further comprising forming the plurality of second traces on a second substrate. 
   
   
       4 . The method of  claim 1 , further comprising creating the fluid-tight gap by forming compressible spacers between the first and second traces, the compressible spacers capable of being compressed during a touch and changing a mutual capacitance of the mutual capacitance sensors. 
   
   
       5 . The method of  claim 1 , further comprising coupling a chip on glass to the first substrate, the chip on glass including sensor panel circuitry. 
   
   
       6 . A method for forming a multi-touch sensor panel, comprising:
 forming a plurality of first traces and a plurality of second traces of substantially transparent conductive material;   orienting the plurality of second and first traces to cross over each other at crossover locations, the crossover locations forming mutual capacitance sensors for detecting touches;   separating the second and first traces by a fluid having substantially no bubbles and an optical index similar to the optical index of the first and second traces to make the first and second traces substantially transparent.   
   
   
       7 . The method of  claim 6 , further comprising forming the plurality of first traces on a second side of a first substrate having a first side capable of being touched, the second side opposite the first side. 
   
   
       8 . The method of  claim 7 , further comprising forming the plurality of second traces on a second substrate. 
   
   
       9 . The method of  claim 6 , further comprising separating the second and first traces using compressible spacers, the compressible spacers capable of being compressed during a touch and changing a mutual capacitance of the mutual capacitance sensors. 
   
   
       10 . The method of  claim 7 , further comprising coupling a chip on glass to the first substrate, the chip on glass including sensor panel circuitry. 
   
   
       11 . A multi-touch sensor panel, comprising:
 a first substrate having a plurality of first traces of substantially transparent conductive material formed thereon;   a plurality of second traces of the substantially transparent material;   a fluid-tight gap formed between the plurality of first and second traces; and   a fluid having substantially no bubbles and an optical index similar to the optical index of the plurality of first and second traces held within the fluid-tight gap, the fluid for making the gap and the plurality of first and second traces substantially transparent;   wherein the plurality of first and second traces are oriented to cross over each other at crossover locations separated by the fluid, the crossover locations forming mutual capacitance sensors for detecting touches.   
   
   
       12 . The multi-touch sensor panel of  claim 11 , wherein the first substrate is a cover glass having a first side capable of being touched, and a second side opposite the first side on which the plurality of first traces are formed. 
   
   
       13 . The multi-touch sensor panel of  claim 12 , further comprising a second substrate having the plurality of second traces formed thereon. 
   
   
       14 . The multi-touch sensor panel of  claim 11 , further comprising compressible spacers coupled between the plurality of first and second traces, the compressible spacers capable of being compressed during a touch and changing a mutual capacitance of the mutual capacitance sensors. 
   
   
       15 . The multi-touch sensor panel of  claim 11 , further comprising a chip on glass coupled to the first substrate, the chip on glass including sensor panel circuitry. 
   
   
       16 . The multi-touch sensor panel of  claim 11 , further comprising a liquid crystal display (LCD) module coupled to the multi-touch sensor panel. 
   
   
       17 . The multi-touch sensor panel of  claim 16 , the multi-touch sensor panel incorporated into a computing system. 
   
   
       18 . The multi-touch sensor panel of  claim 17 , the computing system incorporated into a mobile telephone. 
   
   
       19 . The multi-touch sensor panel of  claim 17 , the computing system incorporated into a digital audio player. 
   
   
       20 . A mobile telephone including a multi-touch sensor panel, the multi-touch sensor panel comprising:
 a first substrate having a plurality of first traces of substantially transparent conductive material formed thereon;   a plurality of second traces of the substantially transparent material;   a fluid-tight gap formed between the plurality of first and second traces; and   a fluid having substantially no bubbles and an optical index similar to the optical index of the plurality of first and second traces held within the fluid-tight gap, the fluid for making the gap and the plurality of first and second traces substantially transparent;   wherein the plurality of first and second traces are oriented to cross over each other at crossover locations separated by the fluid, the crossover locations forming mutual capacitance sensors for detecting touches.   
   
   
       21 . A digital audio player including a multi-touch sensor panel, the multi-touch sensor panel comprising:
 a first substrate having a plurality of first traces of substantially transparent conductive material formed thereon;   a plurality of second traces of the substantially transparent material;   a fluid-tight gap formed between the plurality of first and second traces; and   a fluid having substantially no bubbles and an optical index similar to the optical index of the plurality of first and second traces held within the fluid-tight gap, the fluid for making the gap and the plurality of first and second traces substantially transparent;   wherein the plurality of first and second traces are oriented to cross over each other at crossover locations separated by the fluid, the crossover locations forming mutual capacitance sensors for detecting touches.   
   
   
       22 . A multi-touch sensor panel, comprising:
 a plurality of first traces and a plurality of second traces of substantially transparent conductive material, the plurality of second and first traces oriented to cross over each other at crossover locations, the crossover locations forming mutual capacitance sensors for detecting touches; and   a fluid separating the second and first traces, the fluid having substantially no bubbles and an optical index similar to the optical index of the first and second traces to make the first and second traces substantially transparent.   
   
   
       23 . The multi-touch sensor panel of  claim 22 , further comprising a first substrate upon which the plurality of first traces are formed, the first substrate being a cover glass having a first side capable of being touched, and a second side opposite the first side upon which the plurality of first traces are formed. 
   
   
       24 . The multi-touch sensor panel of  claim 23 , further comprising a second substrate having the plurality of second traces formed thereon. 
   
   
       25 . The multi-touch sensor panel of  claim 22 , further comprising compressible spacers coupled between the plurality of first and second traces, the compressible spacers capable of being compressed during a touch and changing a mutual capacitance of the mutual capacitance sensors. 
   
   
       26 . The multi-touch sensor panel of  claim 22 , further comprising a chip on glass coupled to the plurality of first traces, the chip on glass including sensor panel circuitry.