The Death of Sapphire and the Birth of “Phire”

on February 27, 2015

Last fall, after Apple introduced the new iPhone 6 and 6 Plus and they did not include the much rumored sapphire screen they had been working on with GT Advanced, I started looking into why this did not happen. In a column I wrote in Time last fall, I explained there were major production issues related to sapphire and found out that, in the end, GT Advanced had serious problems producing sapphire screens and could not deliver. In that article, I stated Apple had never planned to have sapphire screens in the new iPhones but that apparently was not correct. My sources did not clarify a key point related to the original intent vs what took place by the beginning of 2013 that took sapphire completely out of the picture for the newest iPhones. Apple went into the deal with GT Advanced wanting to use sapphire screens but, by late 2013, they realized this just could not happen.

Over the last few months I have delved deeper into the role sapphire could play in smartphones and keep coming up with the incredible difficulty involved with making these screens in serious quantities and at a cost that makes sense to use in even top of the line smartphones. Also, the trend in smartphones is moving to larger screens where the cost of a sapphire screen would be even more expensive to produce and buy. Because of the high price of sapphire screens, they would never be used on the majority of smartphones sold as most of them are under $249 and sapphire would make them much more expensive.

I recently recorded a podcast with two professors of material sciences that helped me gain an even better understanding about the costs and manufacturing involved with creating sapphire screens in volume. Joining me in the discussion were Richard Lehman, a professor and chair of the Department of Materials Science and Engineering at Rutgers and director of the school’s Advanced Polymer Center; and Dr. Helen Chan, chair of the Department of Materials Science and Engineering at Lehigh University.

You can listen at this link. Here are some of the key points we discussed:

• Glass is used in almost all smartphone screens and is a great solution. Lehman pointed out that sapphire is used in watches and products that have a long life. However, smartphones have a lifespan of 18 to 24 months and the extra cost may not be worth it for most people.

• Lehman said glass costs about a nickel per square inch to manufacture while sapphire costs several dollars per square inch. He also pointed out manufacturing glass is highly scalable and Dr. Chan explained it takes a 2,000-degree furnace to melt the sapphire boules, which has a serious impact on the environment.

• While neither professors are experts in manufacturing, they brought up key points on the virtue of sapphire as a potential material for screens, but questioned anyone’s ability to make these screens in large volumes. In addition to the melting, the sapphire must be cut razor thin and subjected to extra polishing, according to Chan. It takes at least 4 different steps to produce each sapphire screen.

They also pointed out hardness (a key attribute of sapphire) might not be the best way to go with next generation smartphones. Here is a link to a video from uBreakiFixCo that illustrates this point well and explains the breaking point of glass vs sapphire.

I encourage you to listen to the podcast, as it really helped clarify this issue for me.

Although the podcast and the uBreakiFixCo video explains for me the option of using sapphire as a screen material for smartphones, it really brings up a key question in my mind about the long term prospects of sapphire being used as an alternative to glass. Given the additional cost to make a sapphire screen vs glass and the increasing evolution of glass itself (it is getting stronger and more scratch proof), it seems anyone pursuing sapphire for use on smartphones would be up against some pretty formidable challenges and chances of success. Add to that the fact that, with glass, you can add to its surface a microbial coating, make it much less reflective than sapphire, and even curve it as some smartphone vendors are doing now and it seems to me glass is destined to dominate the smartphone landscape for the foreseeable future.

However, a recent development by Corning may make the use of sapphire in smartphones moot. At their investors meeting earlier this year, Corning discussed the virtues of their newest version of Gorilla Glass 4 and shared its key attributes over Gorilla Glass 3. They include:

-> 2X Improvement in damage resistance

-> 25% reduction in thickness for the same retained strength. Gorilla Glass 4 at 0.55mm has the same retained strength as Gorilla Glass 3 at 0.8mm (>40% reduction in thickness)

-> Up to 2X improved drop performance on rough surfaces and is in production and on commercially available products today

But, in a slide toward the end of the investor presentation, they talked about something new in the works that got a lot of attention on Wall Street and with the media.

It is called ProjectPhire and is a new glass-based solution with damage resistance like Gorilla Glass and scratch performance approaching sapphire. It is in the design phase now but will be available for use in smartphones by late in the year. Here is part of the slide that explains how it is similar to sapphire.

From what I understand about ProjectPhire, it will deliver an experience very similar to sapphire but at much lower costs and in a process much more eco-friendly. If ProjectPhire delivers on this promise, I think it virtually takes sapphire out of the smartphone screen debate in the future. While sapphire is not going to die given its use in watch crystals, jewelry, and, in Apple’s case, on the fingerprint reader/button on iPhones, this new version of Corning Gorilla Glass could end up becoming the de facto standard in mid-to-premium smartphones. And then the need to even consider the use of sapphire in these types of smartphone screens dies.