Apple Inc.
Substrate marking for sealing surfaces

Abstract:

An electronic device includes a housing having an opening that includes an interior surface with a portion that is only viewable from an external vantage point at a viewing angle that is other than ninety degrees (90.degree.). The electronic device also includes a SIM card tray that is removable from the housing via the opening and the SIM card tray includes an angled surface. Information is encoded in the form of text that is laser etched on the angled surface. The text is characterized as having an aspect ratio that corresponds to the viewing angle.