Ultra-thin touch sensors
Touch screens with ultra-thin stack-ups can provide for a lower profile device, can improve the optical image on the display by reducing the display to cover glass distance, and can reduce the weight of the device. In some examples, the thickness of the touch screen stack-up can be reduced and/or the border region reduced, by removing the flex circuit connection from the stack-up. A flexible substrate can be used to enable routing of touch electrodes to touch circuitry. In some examples including a shield layer, the thickness of the touch screen stack-up can be reduced by routing the shield layer to a shield electrode on the touch sensor panel. The shield layer can then be routed to touch sensing circuitry via the flexible substrate. In some examples, the touch sensor panel or a portion of thereof can be integrated with the polarizer.
1. A touch screen comprising:
a display; and
a touch sensor panel disposed on the display, the touch sensor panel comprising:
a substrate formed from a flexible material including a first portion and a second portion;
a plurality of first touch electrodes formed on a first surface of the substrate;
a plurality of first conductive traces disposed on the first surface of the substrate configured to route the plurality of first touch electrodes to touch sensing circuitry; and
a first protective layer disposed on the plurality of first conductive traces;
wherein:
the first portion of the substrate including the plurality of first touch electrodes is planar,
the second portion of the substrate including the plurality of first conductive traces is non-planar such that the substrate extends beyond a first dimension of the display, and
the second portion of the substrate wraps around from the touch sensor panel to a different layer in the touch screen, the different layer separated from the touch sensor panel by the display.
2. The touch screen of claim 1 , further comprising a first coating layer disposed on the first surface of the substrate, wherein the plurality of first touch electrodes formed on the first surface of the substrate are disposed on the first coating layer.
3. The touch screen of claim 2 , further comprising a second protective layer disposed on the first coating layer, wherein the plurality of first touch electrodes formed on the first surface of the substrate are disposed on the second protective layer.
4. The touch screen of claim 1 , wherein the second portion of the substrate is separated from the display such that a gap is formed between the second portion of the substrate and the display.
5. The touch screen of claim 1 , wherein the substrate wraps around from the touch sensor panel to a different layer in the touch screen on a first side of the touch screen without the substrate wrapping around to the different layer in the touch screen on a second side of the touch screen, different than the first side of the touch screen.
6. The touch screen of claim 1 , wherein the plurality of first touch electrodes are formed from indium tin oxide and the plurality of first conductive traces are formed without indium tin oxide.
7. The touch screen of claim 1 , wherein the plurality of first touch electrodes are formed from silver nanowire and the plurality of first conductive traces are formed from silver nanowire.
8. The touch screen of claim 1 , wherein the first portion of the substrate is coterminous with the display.
9. The touch screen of claim 1 , wherein a third portion of the substrate is planar and separated from the first portion of the substrate by the display, the third portion including at least part of the plurality of first conductive traces.
10. The touch screen of claim 1 , wherein the first protective layer is further disposed on the plurality of first touch electrodes.
11. A touch screen comprising:
a display; and
a touch sensor panel disposed on the display, the touch sensor panel comprising:
a substrate formed from a flexible material including a first portion and a second portion;
a plurality of first touch electrodes formed on a first surface of the substrate;
a plurality of first conductive traces disposed on the first surface of the substrate configured to route the plurality of first touch electrodes to touch sensing circuitry;
a first protective layer disposed on the plurality of first conductive traces;
a plurality of second touch electrodes formed on a second surface of the substrate opposite the first surface of the substrate;
a plurality of second conductive traces disposed on the second surface of the substrate configured to route the plurality of second touch electrodes to the touch sensing circuitry; and
a second protective layer disposed on the plurality of second conductive traces;
wherein:
the first portion of the substrate including the plurality of first touch electrodes is planar,
the second portion of the substrate including the plurality of first conductive traces is non-planar such that the substrate extends beyond a first dimension of the display,
the first portion of the substrate that is planar includes the plurality of second touch electrodes, and
a third portion of the substrate including the plurality of second conductive traces is non-planar such that the substrate extends beyond a second dimension of the display, different than the first dimension of the display.
12. The touch screen of claim 11 , wherein the third portion of the substrate wraps around from the touch sensor panel to a different layer in the touch screen.
13. The touch screen of claim 11 , wherein the third portion of the substrate is planar and separated from the first portion of the substrate by the display, the third portion including at least part of the plurality of second conductive traces.
14. The touch screen of claim 11 , further comprising a first coating layer disposed on the second surface of the substrate, wherein the plurality of second touch electrodes formed on the second surface of the substrate are disposed on the first coating layer.
15. The touch screen of claim 14 , further comprising a third protective layer disposed on the first coating layer, wherein the plurality of second touch electrodes formed on the second surface of the substrate are disposed on the third protective layer.
16. The touch screen of claim 11 , wherein the third portion of the substrate is separated from the display such that a gap is formed between the third portion of the substrate and the display.
17. The touch screen of claim 11 , wherein the plurality of second touch electrodes are formed from indium tin oxide and the plurality of second conductive traces are formed without indium tin oxide.
18. The touch screen of claim 11 , wherein the plurality of second touch electrodes are formed from silver nanowire and the plurality of second conductive traces are formed from silver nanowire.
19. The touch screen of claim 11 , wherein a fourth portion of the substrate is planar and separated from the first portion of the substrate by the display, the fourth portion including at least part of the plurality of second conductive traces.
20. The touch screen of claim 11 , further comprising a first coating layer disposed on the first surface of the substrate, wherein the plurality of first touch electrodes formed on the first surface of the substrate are disposed on the first coating layer.