Printing an electrical device using flexographic plate with protective features
A printed electrical device is formed using a flexographic printing system. A flexographic printing plate having a pattern of raised features includes an active region having a plurality of parallel traces separated by a trace spacing of between 5-40 microns that are used to form active micro-traces that provide an electrical function, and an inactive region adjacent to the active region having one or more protective features that are used to form electrically-inactive features. The protective features are separated from an outermost trace of the plurality of traces by a gap distance of between 60% and 250% of the trace spacing. The flexographic printing plate is used to transfer ink from an anilox roller to a substrate to provide a printed pattern corresponding to the pattern of raised features on the flexographic printing plate.
1. A method for forming a printed electrical device using a flexographic printing system, comprising:
providing a flexographic printing plate including a pattern of raised features for transferring ink from an anilox roller to a substrate, wherein the flexographic printing plate includes:
an active region wherein the pattern of raised features includes a plurality of traces that follow substantially parallel paths which print a corresponding pattern of active print features that are used to form active micro-traces that provide an electrical function in the printed electrical device, wherein adjacent traces in the plurality of traces are separated by a trace spacing; and
an inactive region adjacent to the active region wherein the pattern of raised features includes one or more protective features which print a corresponding pattern of protective print features that are used to form features that are electrically inactive in the printed electrical device, wherein the one or more protective features are separated from an outermost trace of the plurality of traces by a gap distance, the gap distance being between 60% and 250% of the trace spacing; and
using the flexographic printing plate in the flexographic printing system to transfer ink from the anilox roller to the substrate to provide a printed pattern corresponding to the pattern of raised features on the flexographic printing plate.
2. The method of claim 1 , wherein the one or more protective features include a trace that is substantially parallel to the outermost trace.
3. The method of claim 1 , wherein the one or more protective features include one or more line segments.
4. The method of claim 3 , wherein the one or more line segments are substantially parallel to the outermost trace.
5. The method of claim 1 , wherein the one or more protective features include one or more isolated dots.
6. The method of claim 1 , wherein the outermost trace includes a bend where the outermost trace changes direction, and wherein one or more of the protective features are positioned in proximity to the bend.
7. The method of claim 1 , wherein the trace spacing is between 3 microns and 40 microns.
8. The method of claim 1 , wherein the raised features have printing surfaces, and wherein the printing surfaces of the traces have a trace width of between 1 micron and 30 microns.
9. The method of claim 8 , wherein the anilox roller includes cells having a cell size, and wherein the trace width is less than 200% of the cell size.
10. The method of claim 1 , wherein the active micro-traces are conductive micro-wires.
11. The method of claim 10 , wherein the ink is a catalytic ink, and further including using an electroless plating process to plate a conductive material onto the catalytic ink of the printed pattern to provide a conductive pattern, wherein the conductive material plated onto the pattern of active print features form corresponding conductive micro-wires.
12. The method of claim 10 , wherein the ink is a conductive ink such that the pattern of active print features in the printed pattern form corresponding conductive micro-wires.
13. The method of claim 1 , wherein the ink has semiconductor properties or insulator properties.
14. The method of claim 1 , wherein the plurality of traces are substantially parallel to a nip between the anilox roller and the flexographic printing plate.
15. The method of claim 14 , wherein the substrate moves through the flexographic printing system from upstream to downstream, and wherein the protective print features are printed on the substrate downstream of the pattern of active print features.
16. The method of claim 1 , wherein the plurality of traces are substantially perpendicular to a nip between the anilox roller and the flexographic printing plate.
17. The method of claim 16 , wherein the flexographic printing plate further including two additional raised features located in proximity to the outermost trace, and wherein the protective features are located along the outermost trace laterally in between the two additional raised features.
18. The method of claim 1 , wherein the micro-traces formed by the pattern of active print features are electrical bus lines.
19. The method of claim 1 , wherein the one or more protective features are separated from any other raised features besides the plurality of traces by a distance of at least 200% of the trace spacing.
20. The method of claim 1 , wherein the inactive region is a first inactive region, and wherein the flexographic printing plate further includes a second inactive region adjacent to the active region on an opposite side of the active region from the first inactive region, wherein the pattern of raised features in the second inactive region includes one or more additional protective features which print a corresponding pattern of additional protective print features that are electrically inactive in the printed electrical device, wherein the one or more additional protective features are separated from a second outermost trace of the plurality of traces by a gap distance, the gap distance being between 60% and 250% of the trace spacing.