Sapphire is obviously well known as a kind of jewelry, so why is it often associated with the future of smart phone screens?

In fact, sapphire is not only a gem, but also a crystalline form of alumina. Because it contains iron and titanium, it will show a natural blue halo.

What's good for mobile phones?

Sapphire has been produced for some time, and this material has been used in all watches and transparent armor of military vehicles of the famous Swiss watch brand TAG Heuer. The reason behind this is also very reasonable.

As we all know, diamond is the hardest substance in nature, and the Mohs hardness scale gives it a rating of 10.

By measuring the vulnerability of different minerals to scratches, Mohs hardness scale will give a rating of 1- 10, in which 1 is the softest and 10 is the hardest.

The Mohs hardness of sapphire is grade 9, which is second only to diamond and two grades higher than ordinary glass. In other words, if used as a mobile phone screen, sapphire is much more scratch-resistant and shatterproof than traditional chemically strengthened glass.

Although we don't think your next mobile phone will be as bulletproof as the windshield of the M 142 high-mobility multi-barrel rocket launcher system, the sapphire mobile phone screen should be more resistant to bumps, bumps and scratches.

Before that, why didn't you use sapphire for your mobile phone?

For the mobile phone industry, sapphire is not new. Some mobile phone products have already used this material to make mobile phone screens, but they are mainly high-end products, just like some models of Vertu.

At the same time, Apple has actually used this material: sapphire is used to protect the iPhone 5 and 5s lenses, and the 5s touch ID fingerprint sensor is also covered with sapphire.

How about gorilla glass?

The popularity of sapphire has brought great pressure to the current mobile phone screen manufacturers, and the most worrying thing is probably Corning, the manufacturer of GorillaGlass.

Corning's GorillaGlass is a screen technology widely used in a large number of high-end flagship phones. Many popular models, including HTC One, GalaxyS4, LG G2, Lumia 1520, use gorilla glass as screen protection glass.

According to the data released by Corning, more than 654.38+0.5 billion devices have used their own GorillaGlass, which is obviously a number to be reckoned with.

MatthewHall, director of the Advanced Ceramic Technology Center of Alfred University School of Engineering, said: "Chemically strengthened glass can be excellent, but sapphire is superior in hardness, strength and toughness."

He added: "The fracture toughness of sapphire should be four times that of gorilla glass, which are 3MPa-0.5 and 0.8 MPa-m0.5 respectively."

However, it also brings some considerable shortcomings. Sapphire weighs more per cubic centimeter (3.98g) than GorillaGlass(2.54) and refracts a little more light.

This means that the sapphire screen will appear darker in the same light environment.

Gorilla glass also has a bigger magic weapon to win, and that is productivity. Hall admits that he doesn't "know the details of sapphire production", but according to his understanding, all methods are based on batches, and the related glass making process is essentially sustainable.

This means that the production cost of sapphire will be higher. According to the analyst's prediction, the cost of gorilla glass is only about 10% of that of sapphire.

So the iPhone will be more expensive?

The reasonable assumption is that the sapphire screen will increase the price of the next generation iPhone, unless Apple finds a way to absorb the extra cost, or produces a large enough quantity to reduce the cost.

Recently, Apple bought out GTAdvanced for three years, which should be to reduce the production cost of sapphire. GTAdvanced's technology can produce sapphire substrates thinner than hair and can be installed on glass display screens. This method can obviously reduce the production cost of sapphire screen.

The $578 million deal will also allow GT to purchase nearly 65,438+0,000 furnaces to produce sapphire screens, thus further reducing production costs.

Is there a problem?

These efforts of both sides should be able to overcome the biggest problem faced by sapphire screen, but there is more than one problem.

At present, there is still a big problem that plagues sapphire, which is the purple glare in the bright area when the iPhone5 camera takes pictures. This phenomenon is caused by sapphire lenses.

If the iPhone uses a sapphire screen, screen brightness will also become another key issue. If the brightness is not up to standard, the outdoor use of iPhone will become a problem.