United States Patent and Trademark Office published an Apple patent filing that highlights the techniques for the usage of sapphire coating on the iOS devices primarily on an iDevice screen. Apple would definitely be planning this upgrade for the upcoming iPhone and iPad, thereby replacing the Corning Gorilla Glass protection.
Originally filed on July 19, 2012, the “Attachment Techniques” patent describes how sapphire can be coated on the devices’ display. The patent also describes how the sapphire coating will help in reducing the dissipated heat generated by the device.
The patent highlights the “Techniques for attachment of sapphire substrates with other materials” and the resulting structures are provided as examples. It suggests the usage of sapphire as the display cover glass as well as the rear camera cover.
As reported by Macrumors, the process would require using a sapphire substrate with an aperture within it and filling it with a second material or plastic with a comparatively lower melting point. The resulting structure can effectively serve as the cover glass for the iDevice display.
Sapphire could also be used as a heat spreader because of the similar levels of thermal conductivity in the material. Apple also mentioned about using sapphire in future as a heat sink for the processors.
“The aperture formed in the substrate may have one or more securing features to help hold the second material within the aperture. For example, the aperture may have one or more tapered sidewalls. Alternatively, or additionally, the aperture may have a notch or step in one or more sidewalls. In still other embodiments, an interior surface of the aperture may be threaded or include a lip or protrusion that serves as a securing feature. It should be appreciated that other securing features may be implemented and, further, that multiple securing features may be used in conjunction”, Macrumors
Currently, Apple majorly uses the Corning’s Gorilla Glass as the protective material for the cover glass. Small pieces of sapphire are however used on the camera cover and home button in the iPhone 5S. Apple might completely replace the Gorilla glass with the better sapphire.
Apple dropped this idea earlier in June 2013 after declaring it infeasible that time, but now announces to launch a sapphire glass manufacturing plant in Arizona. Now most of the smartphone manufacturers are considering the sapphire because of its better resistance and protection capabilities.