Shaping a cover glass
The fabrication of a touch sensor panel having co-planar single-layer touch sensors fabricated on the back side of a cover glass is disclosed. It can be desirable from a manufacturing perspective to perform all thin-film processing steps on a motherglass before separating it into separate parts. To perform thin-film processing on a motherglass before separation, a removable sacrificial layer such as a photoresist can be applied over the thin-film layers. Next, the motherglass can be scribed and separated, and grinding and polishing steps can be performed prior to removing the sacrificial layer. In alternative embodiments, after the protective sacrificial layer is applied, the bulk of the coverglass can be dry-etched using a very aggressive anisotropic etching that etches primarily in the z-direction. In this embodiment, the etching can be patterned using photolithography to create rounded corners or any other shape. The photoresist can then be removed.
1. A method of fabricating a plurality of touch sensor panels on one side of a substrate, comprising:
etching partially through a substrate sheet on a first side of first and second opposing sides of the substrate sheet;
forming the plurality of touch sensor panels on the second side of the substrate sheet;
applying a removable protective sacrificial layer over the touch sensor panels;
singulating the substrate sheet to separate the plurality of touch sensor panels; and
removing the protective sacrificial layer from each of the plurality of touch sensor panels.
2. The method of claim 1 , further comprising forming each touch sensor panel as a plurality of co-planar single-layer touch sensors.
3. The method of claim 1 , further comprising forming the plurality of touch sensor panels using thin-film processing.
4. The method of claim 1 , wherein the substrate is a cover glass and the substrate sheet is a mother glass.
5. The method of claim 1 , further comprising applying photoresist as the removable protective sacrificial layer.
6. The method of claim 1 , further comprising singulating the substrate sheet using scribe and break techniques.
7. The method of claim 1 , further comprising performing grinding and polishing the separated touch sensor panels prior to removing the sacrificial layer.
8. The method of claim 1 , further comprising singulating the substrate sheet using dry-etching techniques.
9. The method of claim 1 , further comprising forming a step in the substrate supporting each of the touch sensor panels prior to singulating the substrate sheet.
10. The method of claim 9 , further comprising forming the step using etching techniques.
11. The method of claim 1 , further comprising forming radiused corners in the substrate supporting each of the touch sensor panels prior to forming the touch sensor panels.
12. The method of claim 11 , further comprising forming the radiused corners using etching techniques.