Why Apple Never Targeted Sapphire Screens for the New iPhones

on September 19, 2014
Reading Time: 5 minutes

When Apple and GT Advanced announced a partnership to make and purchase sapphire screens, most of the media jumped to the conclusion Apple was going to use them in their upcoming smartphones. However, when the iPhones were launched and no sapphire screens were used in the iPhone 6 or the iPhone 6 Plus, I began digging into the reason. What I have learned about this issue and why Apple chose not to include sapphire in this generation of iPhone is fascinating and reinforces why all of us need to be more careful before jumping to conclusions. Many have suggested the decision not to use sapphire was the result of manufacturing issues – with more time, Apple would, in fact, put sapphire on the iPhone 6. As I looked closer at Apple’s announcement and after looking more at the benefits and drawbacks of sapphire, it seems Apple had good reasons to go with “ion strengthened curved glass” (Gorilla Glass) vs. sapphire. 

While sapphire has been hyped as an alternative screen for smartphones, the continued use of strengthened glass has less to do with production issues and more with what smartphone manufacturers know about consumers and their preferences. More importantly, about how they actually use them and what they are willing to pay for their smartphones.

By the way, some reports stated that. up until a few weeks before the theiPhone announcement, Apple was going to use Sapphire but dropped it because of yield issues. This is not true. My sources tell me sapphire was never targeted for the iPhone 6 or 6 Plus and its role in future iPhones has not even been decided yet. Also, anyone that knows the manufacturing process knows that, to make tens of millions of screens for an iPhone launch, any order for a screen had to be put in place well over six months ago and planned meticulously into the final manufacturing of these new smartphones by Apple well in advance.

Here is what I was able to find out about sapphire vs glass by doing many interviews and looking at the current research:

•       The trend in smartphone design is to achieve thinner, lighter devices, while making them bigger at the same time. That’s not easy to do. To increase the size of a smartphone and still keep the weight down requires thinner, lighter material. What we know about sapphire is it is more than 30% denser than glass and would require a compromise on both fronts for widespread use in phones. Corning has shown it can manufacture Gorilla Glass to be thinner than a sheet of paper and strengthened with a process that makes it more damage resistant.

•       Cost is a big factor with consumers and the smartphone category is hugely competitive these days. Apple is already pushing the envelope on price when comparable devices are priced at or lower than the iPhone 6, and Apple would have had to charge even more for a sapphire covered phone.  The cost to produce a sheet of sapphire is estimated to be roughly 10 times that of strengthened glass. In fact, one source I talked to said the cost could be even higher. Our researched opinion early on was, if Apple did add a sapphire screen for a new iPhone, it would add at least $100 to the base cost of the iPhone. That could be a deal breaker for mainstream iPhone customers.

•       Design flexibility and adaptability – the latest smartphone designs from Samsung, Apple and others are sleek, sporting displays with glass that curves to the edge of the device. Because glass can be manufactured to extremely thin dimensions and still be chemically strengthened, it is more flexible and can be formed and shaped into the designs you see in the iPhone 6 and others. http://www.ubreakifix.com/blog/sapphire-vs-gorilla-glass-bending-and-impact/ Sapphire is bulkier and must be cut into shape, creating both cost and production issues on larger surfaces. Today,  Sapphire in phones shows up in only industrial style products, like the Kyocera Brigadier which uses a bulky casing to protect the screen.

•       Battery life – by far the number one complaint among consumers is battery life in a phone. Manufacturers need to look at every component that draws energy and work to minimize the impact to help keep battery life strong. One of the biggest drains on battery life is brightness of the screen.  According to Bernstein Research, which conducted research on the benefits of glass vs. sapphire as a cover material, glass transmits light much better than sapphire. Therefore, to get the same level of brightness using a sapphire screen requires more energy. That problem can’t be fixed easily as the basic properties of sapphire make it transmit less light than glass. This also impacts other things like glare. Glass can have an anti-reflective solution imbedded into the material, reducing the effects of the sun when reading outdoors. To achieve anti-reflection with sapphire, it has to have a coating applied which, over time, will wear off. This issue alone may make it tough for Apple to ever use sapphire in iPhones since most people have their iPhones for at least two years and some even longer.

•       Environmental impact – manufacturers know consumers are starting to care a lot more about the impact the products they buy are having on the environment. Sapphire requires 100 times more energy to produce than glass. The energy requirements alone make sapphire problematic as a viable material to use on a smartphone. It is not out of the realm of possibility sapphire could end up on very high end smartphones someday but it’s less likely they could ever be used in smartphones aimed at the mass market.

•       Durability – this is by far the most promoted benefit of sapphire and perhaps the most misunderstood. This is the area I got tripped up on by assuming too much from the Apple investment in GT Advanced. Sapphire is extremely hard and highly scratch resistant. That is why it is found on products such as luxury watches. But it is largely untested as a phone screen. While sapphire is a very hard crystal, it is inflexible and extremely brittle.  Sapphire’s inherent structure makes it susceptible to flaws that can occur along the crystal plane. I was told by multiple sources various field tests subjected sapphire to scratch and break tests against strengthened glass. It performs better on scratch resistance but, when you drop it, it is more likely than glass to break. Glass actually flexes and can absorb the shock of a drop more readily than sapphire. Sapphire is prevalent on luxury watches and other products that don’t experience the same drop risk as a smartphone.

Like many who jumped on the sapphire bandwagon without really understanding it, I had assumed it was unbreakable. But in talking to various experts, they said the way to look at this is to think of a sheet of ice (also a crystal); small cracks weaken the surface and it will hold together for only so long before some impact will cause it to break. Those small cracks add up in the normal wear and tear we put our phones through every day – knocking around in our purses and pockets with keys and change or scuffing against the surface of a counter repeatedly. Current solutions, such as Gorilla Glass, apparently are reinforced with a chemical that alter its atomic structure and actually strengthens the area around scratches and insulates the glass longer against breaking. While surface scratches may be more visible earlier on, a glass screen will stay more intact over time than one made with sapphire. Once sapphire is exposed to a scratch or a flaw, visible or invisible, its risk of breakage and eventual failure is high. On watches, this is less an issue because they are seldom dropped and the watch surface is smaller. But in a smartphone with larger screens and many usage variables, this could make it difficult to put in smartphones and guarantee it is less prone to breakage.

I don’t doubt over time there could be some breakthroughs with sapphire and new coating processes could make it possible to use as a screen on a smartphone. However, from the research I did, it does not appear it could happen any time soon. Plus, sapphire’s less then flexible and brittle nature suggests, as least to me, that using it in large screen smartphones would still be difficult even if they were able to coat it in a way to keep the screen from splintering. I now at least understand why Apple did not use it in the new iPhones and the more I study this it seems it could be problematic for Apple to use it outside of their smartwatches anytime in the very near future.