PCAP touchscreens with a narrow border design
Some embodiments include fabricating a narrow border of a projected capacitive (PCAP) touchscreen. Some embodiments include a vertical electrode on a cover glass coupled to a first set of traces within the narrow border, and printing a first insulating black mask (BM) layer on the cover glass, that includes a first opening above an electrode terminus of the vertical electrode. Some embodiments further include printing a portion of a conductive black via (BV) in the first opening, coupling the conductive BV to the electrode terminus and a first silver trace of the first set of silver traces. Some embodiments include combining the cover glass with a sensor glass, where the first set of silver traces substantially overlaps a second set of silver traces of the sensor glass within the narrow border, where the overlapped sets of silver traces are separated by a shield layer.
1. A method for fabricating a narrow border of a projected capacitive (PCAP) touchscreen, comprising:
disposing on a first layer, a first transparent electrode coupled to a first silver trace of a first set of silver traces within the narrow border of the PCAP touchscreen;
printing a first insulating black mask (BM) layer on the first layer, wherein the first insulating BM layer includes a first opening above an electrode terminus of the first transparent electrode;
printing a portion of a conductive black via (BV) in the first opening, wherein the portion of the conductive BV is coupled to the electrode terminus and coupled to the first silver trace;
disposing on a second layer, a second transparent electrode parallel to the first transparent electrode, the second transparent electrode coupled to a second silver trace of a second set of silver traces; and
assembling the first layer with the second layer, wherein the first set of silver traces substantially overlaps the second set of silver traces within the narrow border of the PCAP touchscreen, and wherein the overlapped sets of silver traces are separated by a shield layer.
2. The method of claim 1 , further comprising:
printing a silver paste on the portion of the conductive BV and on the first insulating BM layer where transmitter and receiver silver traces are desired; and
using a laser to ablate excess silver paste.
3. The method of claim 2 , wherein the using the laser to ablate the excess silver paste comprises:
leaving a deposit of the silver paste within a boundary of the portion of the conductive BV wherein the deposit is coupled to the first silver trace; and
defining remaining silver traces of the first set of silver traces.
4. The method of claim 2 , wherein the using the laser to ablate the excess silver paste comprises:
creating a gap through the silver paste and the first insulating BM layer to the first layer; and
printing a second insulating BM layer that fills the gap.
5. The method of claim 4 , wherein the printing the second insulating BM layer comprises printing the second insulating BM layer that covers the first set of silver traces except a second opening that exposes leads of the first set of silver traces to be coupled with a connector.
6. The method of claim 1 , further comprising:
printing a second silver paste on the second layer where transmitter and receiver silver traces are desired; and
using a laser to ablate excess second silver paste.
7. The method of claim 6 , further comprising printing an insulation layer to substantially overlap the second set of silver traces within the narrow border of the PCAP touchscreen, wherein the shield layer is printed on the insulation layer.
8. The method of claim 7 , wherein the printing the second silver paste on the second layer comprises printing a ground silver trace; and wherein the printing the insulation layer comprises printing the insulation layer around a second opening that exposes the ground silver trace to the shield layer.
9. The method of claim 1 , wherein the assembling comprises applying an adhesive between the first layer and the second layer.
10. The method of claim 9 , wherein the adhesive is a solid optically clear adhesive (OCA) comprising: an acrylic-based adhesive, a silicone-based adhesive, polyvinyl butyral (PVB), or ethylene-vinyl acetate (EVA).
11. A projected capacitive (PCAP) touchscreen with a narrow border, comprising:
a first layer comprising a first transparent electrode coupled to a first silver trace of a first set of silver traces within the narrow border of the PCAP touchscreen;
a first insulating black mask (BM) layer on the first layer, wherein the first insulating BM layer includes a first opening above an electrode terminus of the first transparent electrode;
a portion of a conductive black via (BV) in the first opening, wherein the portion of the conductive BV is coupled to the electrode terminus and coupled to the first silver trace;
a second layer parallel to the first layer, comprising a second transparent electrode coupled to a second silver trace of a second set of silver traces; and
the first layer assembled with the second layer, wherein the first set of silver traces substantially overlaps the second set of silver traces within the narrow border of the PCAP touchscreen, and wherein the overlapped sets of silver traces are separated by a shield layer.
12. The PCAP touchscreen of claim 11 , further comprising:
a silver paste printed on the portion of the conductive BV and on the first insulating BM layer where transmitter and receiver silver traces are desired; and
excess silver paste ablated by a laser.
13. The PCAP touchscreen of claim 12 , wherein the laser ablation of the excess silver paste comprises:
a deposit of the silver paste within a boundary of the portion of the conductive BV wherein the deposit is coupled to the first silver trace; and
remaining silver traces of the first set of silver traces.
14. The PCAP touchscreen of claim 12 , wherein the laser ablation of the excess silver paste comprises:
a gap through the silver paste and the first insulating BM layer to the first layer; and
a second insulating BM layer printing that fills the gap.
15. The PCAP touchscreen of claim 14 , wherein the printed second insulating BM layer covers the first set of silver traces except a second opening that exposes leads of the first set of silver traces to be coupled with a connector.
16. The PCAP touchscreen of claim 11 , further comprising:
a second silver paste printed on the second layer where transmitter and receiver silver traces are desired; and
excess second silver paste ablated by a laser.
17. The PCAP touchscreen of claim 16 , further comprising an insulation layer printed to substantially overlap the second set of silver traces within the narrow border of the PCAP touchscreen, wherein the shield layer is printed on the insulation layer.
18. The PCAP touchscreen of claim 17 , wherein the silver paste printed on the second layer comprises a ground silver trace; and wherein the insulation layer is printed around a second opening that exposes the ground silver trace to the shield layer.
19. The PCAP touchscreen of claim 11 , wherein the first layer assembled with the second layer comprises an adhesive between the first layer and the second layer.
20. The PCAP touchscreen of claim 19 , wherein the adhesive is a solid optically clear adhesive (OCA) comprising: an acrylic-based adhesive, a silicone-based adhesive, polyvinyl butyral (PVB), or ethylene-vinyl acetate (EVA).