Touch sensor panel with in-plane backup bypass connections
Touch sensor panels ( 104 ) have 2-D periodic arrangements of electrodes ( 304 ) connected together forming a plurality of horizontal and vertical logical lines ( 506, 514 ) for measuring X-Y coordinates of a user's touch. Electrodes forming the horizontal logical lines are interleaved with electrodes forming the vertical logical lines. Each of the vertical and horizontal logical lines includes multiple tracks ( 502, 504, 510, 512 ). The tracks of each logical line are cross connected by in-plane cross connects ( 314, 318 ) formed in the same layer by the same process that is used to form the electrodes. Diamond and square electrode embodiments are described.
1. A method of making a touch sensor panel comprising:
A. forming a patterned transparent conductor layer including:
a first plurality of logical lines, each of which includes a first plurality of parallel tracks extending in a first direction, each track including electrodes connected in series,
a first plurality of in-plane cross connects connecting the first plurality of parallel tracks at multiple points to provide redundant signal paths for each of the first plurality of logical lines, and
additional areas that are interleaved among the first plurality of parallel tracks,
wherein the additional areas comprise disjoint segments for a second plurality of logical lines each of which includes a second plurality of tracks extending in a second direction perpendicular to the first direction, each track including electrodes connected in series;
a second plurality of in-plane cross connects connecting the additional areas in the second plurality of tracks within each of the second plurality of logical lines to provide redundant signal paths for each of the second plurality of logical lines; and
B. forming a plurality of bridges that bridge the disjoint segments of the second plurality of tracks wherein the plurality of bridges cross over the first plurality of parallel tracks, and wherein forming the plurality of bridges comprises:
B1. forming areas of insulator disposed between the disjoint segments and aligned with portions of the first plurality of parallel tracks that pass between the disjoint segments, and
B2. forming conductive connections aligned with the areas of insulator, wherein the conductive connections connect the disjoint segments and are insulated from portions of the first plurality of tracks that pass between the disjoint segments.
2. The method according to claim 1 wherein A, B1, B2 are performed in the order A, B1, B2.
3. The method according to claim 1 wherein A, B1, B2 are performed in the order B2, B1, A.
4. The method according to claim 1 wherein forming the patterned transparent conductor layer comprises:
forming a 2-D periodic array of a plurality of areas, wherein the first plurality of parallel tracks comprise at least a first subset of the plurality of areas and the second plurality of tracks comprise at least a second subset of the plurality of areas, and the first subset of the plurality of areas is interleaved with the second subset of the plurality of areas.
5. The method according to claim 4 wherein forming the 2-D periodic array of areas comprises forming a 2-D periodic array of diamond shaped areas.
6. The method according to claim 4 , wherein forming the 2-D periodic array of areas comprises forming a 2-D periodic array of rectangular shaped areas.
7. The method according to claim 1 , wherein a first number of tracks in the first plurality of tracks is different from a second number of tracks in the second plurality of tracks.