Apple Inc.
Back of cover touch sensors

Abstract:

Touch sensor configurations for reducing electrostatic discharge events in the border area of a touch sensor panel is disclosed. Touch sensors (e.g., electrodes formed on the cover material and/or the opaque mask) can be susceptible to certain events such as arcing and discharge/joule heating, which may negatively affect touch sensor performance. Examples of the disclosure can include increasing the trace width, spacing, and/or thickness in the border area relative to the trace width, spacing, and/or thickness in the visible/active area along one or more sides of the touch sensor panel. In some examples, touch electrodes can be located exclusively in the visible/active areas along one or more sides of the touch sensor panel, while dummy sections can be included in both the border and visible/active areas. Additionally or alternatively, one or more gaps between adjacent touch electrodes in the border area or serpentine routing can be included.