Don't look for sapphire glass for the next iPhone's display
Apple started using Gorilla Glass with the original iPhone because it offered much better scratch resistance and strength compared to other display surface materials while at the same time being relatively thin and light weight. The relationship between the two companies paid off because Apple was able to sell smartphones with durable displays while Corning was able to sell its Gorilla Glass in quantities it hadn't been able to attain before.
With the iPhone 6 and iPhone 6 Plus, however, Apple had hoped to move away from Corning's products by making its own synthetic sapphire glass. Sapphire is much harder than Gorilla Glass, making it much more resistant to scratching—a trait that previous iPhone models all had to deal with.
That glass was also destined for the Apple Watch, due to ship in April. Some of GTAT's glass made it there, but Apple will be buying most of its sapphire from other manufacturers.
The downside to sapphire glass is that its hardness also makes it brittle. Drop your iPhone, and its display would be even more likely to break than now. Even if Apple found a way to formulate synthetic sapphire to better hold up under drops, we won't know because GTAT failed to produce usable glass in the quantities needed, and ultimately abandoned its glass making efforts.
In contrast to synthetic sapphire, Corning's Gorilla Glass is much more resilient when dropped. The company has continued to improve its product in the years since the original iPhone shipped, and currently its Gorilla Glass 4 is is the name in hardened glass for smartphone displays.
Seeing Apple's efforts to make its own sapphire glass, Corning worked to make a version of Gorilla Glass that performs just as well, and it looks like the company has come very close. The company just announced a new hardened glass material called Project Phire which offers the best of both worlds: Gorilla Glass 4's strength with synthetic sapphire's high scratch resistance.
During Project Phire's introduction last week, Croning Glass Technologies president James Clappin said,
We told you last year that sapphire was great for scratch performance but didn't fare well when dropped. So, we created a product that offers the same superior damage resistance and drop performance of Gorilla Glass 4 with scratch resistance that approaches sapphire.
That combination is exactly what Apple needs for the iPhone and iPad because it eliminates several issues. First, it doesn't come with the scratch resistance versus strength trade off. Second, it will likely come in at a lower price point than sapphire glass. Finally, Project Phire glass comes from a company with a proven track record for delivering products on time and in the quantities Apple needs.
In other words, Corning figured out exactly what Apple wanted in its iPhone display glass and found a way to make it.
Apple could try finding a new partner to make its sapphire glass, but considering the furnaces GTAT had just for that were sold off to other buyers instead of Apple, that doesn't seem very likely. What seems more likely is that Apple cut its losses, will continue to use synthetic sapphire for Touch ID sensors and camera lens covers, and will stick with Corning's materials for iPhone and iPad displays.
Corning's Project Phire looks like an all around better material for iPhone displays, and it comes from a company that has a proven delivery history. Apple may like to control all aspects of its manufacturing process, but its leadership also knows when it's appropriate to buy materials instead of making its own.
GTAT's failure was an important lesson for Apple. Add in Corning's efforts to make a material with the best features from synthetic glass and Gorilla Glass 4, and it's pretty clear where the next iPhone's display glass is coming from. Translation: synthetic sapphire glass has a place on the Apple Watch display, but not on the iPhone.