Whether or not the upcoming iPhone 6 will sport a sapphire crystal display or not is something we’ll have to wait to find out for sure, but the ultra-strong material used by many high end watch manufacturers is certainly something Apple has spent a lot of time investigating. Some of those investigations have led to a new patent application published today, revealing how Apple plans a technique for strengthening glass by using an “ion implanting” method as opposed to the kind of chemical coatings used for, say, Corning’s Gorilla Glass.
The U.S. Patent and Trademark Office on Thursday published an Apple patent describing a method of implanting ions in a sapphire display structure, strengthening the already hard material without using chemical treatments. As noted in Apple’s “Sapphire property modification through ion implantation” patent filing, traditional chemical strengthening techniques used on glass screens may not be effective when applied to other materials such as sapphire. Thus, Apple proposes a new hardening method of impregnating the crystalline lattice structure of corundum, of which sapphire is a variety, with ions to create a compressive stress layer that enhances stability. The invention points out that when a sapphire structure fails or breaks, it’s usually the result of propagations of surface flaws when the component is put under stress. To prevent against cracks during a drop event, Apple’s ion implantation method embeds ions within the sapphire substrate, either between existing crystal lattice sites or naturally occurring voids. In one embodiment, ions may be embedded so as to form an amorphous, or non-crystalline, section within the sapphire substructure.