Circuit-on-Wire (CoW)

Abstract

A circuit-on-wire (CoW) is provided that is made from a flexible metal wire with an outer surface, and a plurality of discrete electrical control devices formed in series along the metal wire outer surface. Each control device may have an electrical contact accessible through the metal wire. In one aspect, the control device may have a via through the metal wire from the top surface to the bottom surface with a second electrical contact accessible through the via. In addition, the control devices may have a top surface with an accessible third electrical contact. For example, the control device may be a first thin-film transistor (TFT), with a gate electrode accessible through the metal wire, wherein the second electrical contact is a first source/drain (S/D) electrode, and wherein the third electrical contact is a second S/D electrode. Using the above-described CoW, a woven active matrix array can be fabricated.

We claim: 
     
         1 . A circuit-on-wire (CoW) comprising:
 a flexible metal wire with an outer surface; and   a plurality of discrete electrical control devices formed in series along the metal wire outer surface.   
     
     
         2 . The CoW of  claim 1  wherein a plurality of the control devices each comprise at least a first electrical contact accessible through the metal wire. 
     
     
         3 . The CoW of  claim 1  wherein the metal wire comprises an outer top surface and an outer bottom surface;
 wherein a plurality of the control devices each comprise:
 a via through the metal wire from the top surface to the bottom surface; and, 
 a second electrical contact accessible through the via. 
 
 
     
     
         4 . The CoW of  claim 3  wherein a plurality of the control devices each further comprise a top surface with an accessible third electrical contact. 
     
     
         5 . The CoW of  claim 4  wherein a plurality of the control devices are each a first thin-film transistor (TFT), with a gate electrode accessible through the metal wire, wherein the second electrical contact is a first source/drain (S/D) electrode. and wherein the third electrical contact is a second S/D electrode. 
     
     
         6 . The CoW of  claim 4  wherein a plurality of the control devices are each a pixel switching element comprising:
 a first TFT, with a gate electrode accessible through the metal wire, wherein the second electrical contact is a first S/D electrode, and wherein the third electrical contact is a second S/D electrode; 
 a storage capacitor connected to the second S/D electrode of the first TFT; 
 a second TFT comprising:
 a via through the metal wire from the top surface to the bottom surface; 
 a first S/D electrode accessible through the via; 
 
 a gate electrode connected the second S/D electrode of the first TFT; and,
 a second S/D electrode. 
 
 
     
     
         7 . canceled 
     
     
         8 . The CoW of  claim 1  further comprising:
 a spool; and, 
 wherein the metal wire is wound around the spool. 
 
     
     
         9 . The CoW of  claim 8  further comprising:
 a plurality of adjacent metal wires wound around the spool, each metal wire including a plurality of discrete electrically active control devices formed in series along its outer surface. 
 
     
     
         10 . canceled 
     
     
         11 . A woven active matrix array comprising:
 a set of parallel first metal lines aligned in a first direction;   a set of parallel second metal lines aligned in a second direction orthogonal to the first direction;   wherein the first metal lines intersect the second metal lines to form pixel regions;   wherein a plurality of metal lines from the second metal lines comprise serially configured circuit-on-wire (CoW) control devices overlying an outer surface of the second metal line; and,   wherein each control device is associated with a corresponding pixel region.   
     
     
         12 . The array of  claim 11  wherein a plurality of control devices each comprises at least a first electrical contact accessible through the second metal wire. 
     
     
         13 - 19 . canceled 
     
     
         20 . The array of  claim 11  wherein the second metal wire further comprises:
 an insulation layer overlying the second metal wire top and bottom surfaces, selectively etched to expose control device electrodes. 
 
     
     
         21 . The array of  claim 11  wherein a plurality of metal lines from the first metal lines comprise serially configured CoW control devices overlying an outer surface of the first metal line. 
     
     
         22 . canceled 
     
     
         23 . A method for forming a woven active matrix array, the method comprising:
 providing a substrate with a top surface;   forming a set of parallel first metal lines aligned in a first direction overlying the substrate top surface;   forming a set of parallel second metal lines aligned in a second direction orthogonal to the first direction, overlying the first metal lines;   forming pixel regions between first and second metal line intersections;   wherein a plurality of metal lines from the second metal lines comprise serially configured circuit-on-wire (CoW) control devices overlying an outer surface of the second metal line, and wherein each control device is associated with a corresponding pixel region.   
     
     
         24 . The method of  claim 23  further comprising:
 forming a pixel device in each pixel region; and, forming electrical contacts between each pixel device and a corresponding control device. 
 
     
     
         25 . The method of  claim 23  wherein forming the second metal lines includes forming second metal lines having insulated top and bottom surfaces, selectively etched to expose control device electrodes;
 the method further comprising:
 prior to forming the second metal lines, depositing an electrically conductive adhesive overlying the first metal lines; and, 
 subsequent to forming the second metal lines, forming electrical contacts between the first metal lines and the control device electrodes. 
 
 
     
     
         26 . A method for forming circuit-on-wire (CoW), the method comprising:
 forming an electrically conductive metal wire; and,   forming a series of discrete control devices overlying the metal wire.   
     
     
         27 . The method of  claim 26  wherein forming the series of discrete control devices includes forming thin-film devices using film deposition and photolithographic etching steps. 
     
     
         28 . The method of  claim 26  wherein forming the series of discrete control devices includes forming a plurality of control devices each having an electrode electrically connected to the metal wire. 
     
     
         29 - 30 . canceled 
     
     
         31 . The method of  claim 26  wherein forming the series of discrete control devices includes forming a plurality of control devices each comprising:
 an electrode on a metal wire top surface; and, 
 a via from the metal wire top surface to a metal wire bottom surface, electrically connected to the electrode. 
 
     
     
         32 . The method of  claim 26  wherein forming the series of discrete control devices includes forming control devices selected from a group consisting of thin-film transistors (TFTs), thin-film diodes, pixel switching elements, and combinations of the above-mentioned devices.