A new patent has emerged from Apple related to Oleophobic Coating, which has been widely used to protect Apple screens from oily fingerprint smudges since 2009. The patent has never been applied to sapphire screens until now so this development is another major milestone for Apple and GT Advanced towards the production of sapphire screen for Apple iDevices.
Appleinsider reported on the patent news this morning.
What is interesting is that this patent allows for the oleophobic coating to be applied to a brick of sapphire and not having to apply it to each cut screen individually i.e. the patent allows for batch processing. The process used to coat sapphire screens is different from traditional glass screens. The patent mentions PVD and sintering as options. Apple and GT may be leveraging GT’s SPS technology for sintering to get this job done in the most efficient way possible Spark Plasma Sintering (SPS)
Some highlights from the patent filing are below:
 This application claims priority to and the benefit of U.S. Provisional Patent Application No. 61/704,275, filed Sep. 21, 2012 and titled “Oleophobic Coating on Sapphire,” the disclosure of which is hereby incorporated herein in its entirety.
 The subject matter of this application relates generally to surface coatings on substrates. In particular, the application relates to oleophobic coatings and other surface coatings on substrates for uses as windows on electronic devices, including, but not limited to, mobile phones and portable computing devices.
 Electronic devices may include a range of different touch-sensitive input surfaces, for example as incorporated into displays, track pads, keyboards, and combinations thereof. In use, however, oils and other deposits may affect appearance and performance, particularly where information is also displayed on the touch-sensitive surface (e.g., on a touch-sensitive display).
 In general, the use of sapphire materials provides substrate 200 with substantially increased hardness, as compared to silica-based glass and other materials. For example, substantially single-crystal forms of sapphire glass may have a hardness of up to about 2000 points on the Vickers scale (about 19.6 GPa), or in a range of about 1800-2300 points on the Vickers scale (about 27.7-22.5 GPa). Alternatively, sintered polycrystalline forms of alumina or sapphire glass may have a Vickers hardness of about 1200-2000 points on the Vickers scale (about 11.8-19.6 GPa), depending on grain size, and fused amorphous forms may have a hardness of about 1000-1200 points on the Vickers scale (about 9.8-11.8 GPa).
 Alternatively, base layer 202 may be formed of an amorphous aluminum oxide, transparent alumina or other sapphire-like material, for example by thin film deposition, sintering, vapor deposition, or other process. In these examples, base layer 202 may also include a combination of amorphous and polycrystalline components, in order provide a selected combination of transparency and hardness.
 In the particular configuration of FIG. 3, deposition units 226 are provided in the form of physical or chemical vapor deposition (CVD or PVD) components. Alternatively, other processes and components may be utilized, for example to treat substrate 200 by sputtering, electron beam deposition or electron beam evaporation, or a combination of such processes.