The iPhone 12, no matter what they say, has become one of the largest updates to Apple’s smartphone line in recent years. In addition to a major hardware upgrade, the new items received an updated design, a 5G modem and a super-durable glass to protect the display called Ceramic Shield. But if a case with chopped edges, a powerful processor, and support for fifth-generation networks were, in principle, expected, then the protective glass with a ceramic component turned out to be a real surprise. Let’s figure out what it is.
iPhone 12 was the first device with Ceramic Shield glass. According to Apple, it is four times stronger than conventional tempered glass used in competing smartphones. A very strange and ambiguous formulation, which, on the one hand, indicates the clearly high strength of the material used, and, on the other, leaves some kind of understatement. Still, it’s not very clear what exactly Ceramic Shield should be compared to – with Gorilla Glass 5 from Corning or some DragonTrail.
What is Ceramic Shield
Despite the name, Ceramic Shield is not literally made of ceramic, and the term Ceramic refers to the use of nano-ceramic crystals in a glass matrix. This is not the same as Gorilla Glass, although the Ceramic Shield was developed by Apple in collaboration with Corning, the manufacturer of the same “gorilla”. Here’s what Corning’s ceramics research page says:
Ceramics might be thought of as the close cousin of glass. Both materials are inorganic. Both have many useful physical properties and are formed via high-temperature processes. And with the right composition and forming, both can be extremely hard and resistant to thermal shock, suitable for use in harsh environments like outer space.
Differences between glass and glass ceramics
The primary difference between glass and ceramics, though, centers on the chemical bonds that hold the internal structure of the material together. Unlike glass, in which atoms are arranged in a random order, linkages in ceramic materials happen when positive and negative ions bond to form a regular pattern of crystals — which, in turn, can scatter the light to which they are exposed. This phenomenon usually results in an opaque material, rather than transparent, although there are examples of transparent ceramics.
Nano-ceramic crystals, although not quite ceramic, increase the impact resistance of glass. Therefore, it becomes more difficult not only to scratch it, but also to break it when dropped. Cupertino considers Ceramic Shield to be a colossal breakthrough for the industry, suggesting that Apple and Corning developed this material from the ground up and was not used in other smartphones before the iPhone 12. In any case, it would be logical, given that in Cupertino they prefer to do their own thing, and not use other people’s best practices.
The only omission that Apple made is the literal one-sidedness of the Ceramic Shield. Simply put, the company for some reason decided to equip the iPhone 12 with glass with nano-ceramic crystals only on the front side, protecting the smartphone display. At the same time, the back cover is still covered with “regular” tempered glass, which was used by Apple in previous generations of iPhone. Why Cupertino did this is not clear. Perhaps they were simply afraid of a tangible increase in cost.