Apple’s new patent relates to further strengthening both the cover glass display and structural housing glass of future iPhones and other devices like a possible future all-glass iMac. Apple notes that while it may be desirable to coat glass structures with anti-scratch and anti-reflection coatings, they create stress concentrations that make the glass structure susceptible to breakage. If care is not taken, glass structures may be susceptible to cracking when subjected to elevated stress during an unintended drop event.
Thin film coating layers may be deposited on the housing using physical vapor deposition or other deposition techniques. The coating layers may be transparent coatings that form anti-reflection layers, anti-scratch layers, opaque layers that may be patterned to form logos, text, or other visual elements, and/or other coating layers.
To prevent damage to a glass display structure in the event that the electronic device is dropped or otherwise subjected to stress, the coating layers on the glass structures of the electronic device may be formed from polycrystalline materials in which grains have been grown in an interlaced spiral configuration.