You may have heard of Gorilla Glass when people are talking about smartphone or tablet screens. Its widely used on mobile devices, for 2400 models over 33 major brands and on 2.4 billions devices according to Corning, the manufacturer of the glass. But what exactly is it and why do we need it?
First of all we need to understand the structure of a display. Typically, a touch screen is made up of 4 layers as shown in the picture. From outside, it will be the cover glass, touch sensor, frontplane and followed by backplane. When we speak of the glass of a screen, we are referring to the cover glass.
Normal type of glass we see everyday is soda lime glass and it is hard yet brittle and thick so having a display covered by normal glass would be a disaster. Plastic, on the other hand, is not scratch resistant. Mobile devices manufacturers need a type of glass that can be used in their products as the cover glass. As the top glass manufacturer, Corning came out with the solution – Gorilla Glass. The type of glass is alkali-aluminosilicate toughened glass and it is famous for its durability, scratch-resistance, thinness and touch-friendliness.
Up to 2014, there are 4 versions of Gorilla Glass. The first generation was introduced in 2007. In 2012, the second generation Gorilla Glass 2 was launched. The improvement in this generation was in the thickness, which was reduced by 20% while retaining all its hardness and durability. Gorilla Glass 3 was announced at CES (Consumer Electronics Show) in 2013. The new iteration was claimed to be 40% more scratch-resistant, more flexible and 3 times more damage-resistant after scratches are formed. In late 2014, Gorilla Glass 4 was announced and the emphasis was on the toughness. Corning claimed that the Gorilla Glass 4 is able to survive 80% of the time when being dropped from one meter height on rough surface.
The history of Gorilla Glass is longer than what I thought. Before Gorilla Glass, this type of glass was actually called ‘Chemcor‘ glass due to the fact that the strengthening is achieved by chemical process. The glass was developed back in 1960s where thickness and weight were not being concerned. Then Corning further improved on the weight and dimension for years. In the year of 2006, Steve Jobs, the CEO of Apple at that time, called Corning to ask if they can produce a type of glass that is durable yet thin enough to be placed in the first iPhone, which was not announced yet at that time. The glass was not ready at that time so Corning had to develop the new cover glass based on ‘Chemcor’ glass. The iPhone was launched in 2007 and this was how the beastly glass was unleashed into the market.
First of all the raw material with correct composition is melted and the liquid glass is fed to a long container until it overflows from both sides of the container. The molten glass will then rejoins below the container to form a continuous sheet of glass with thickness measured in micrometers (a thousandth of a millimetre). This process to draw the unstrengthened glass is called fusion process. Then the glass will be cut to desired size by customers.
Then the glass will undergo ion exchange, which is a chemical process to strengthen the glass. (Remember ‘Chemcor’ ?) The glass is placed in molten potassium salt at 400°C. The larger potassium ions will replace the small sodium ions in the glass, creating high compression among molecules in glass. Imagine that you pumping a lot gas to a ball and the ball will be very hard. This compression is the key where the glass is so damage-resistant.
In the development of Gorilla Glass 3, the design is done by an atomic scale model. The atomic configuration is improved, making the glass tougher even before the chemical processes.
Why It Matters?
Why Gorilla Glass is important to us, the end user? Devices with Gorilla Glass are tougher and more durable. This means that you are less likely to get a cracked screen when you drop your phone accidentally. Your screen will suffer less scratches too even you placed your device with other sharp things like keys in pocket or in bag. Watch this video from YouTube to see how good Gorilla Glass 3 of the new HTC One M8 can perform under the torture of knife and hammer. Its simply amazing.
Having a more durable device simply means that you can use your device for longer period. Then you don’t to break your bank that often for replacement. Since its introduction, having Gorilla Glass in mobile devices are getting more and more common. Starting with high-end models only, now budget devices such as Moto G are having Gorilla Glass 3. Wearables such as Pebble smartwatch and some touch screen laptops are using it too. I hope that this will become a standard and every device will be protected by toughed glass. (Well, it can be glass from other companies if the performance is similar). Devices with Gorilla Glass actually does not need any screen protector too as its scratch-resistance is typically far more superior than screen protectors.
Therefore, when you are choosing a new device, please take this into account. You can check if the device you are interested or you own is protected by Gorilla Glass here. Please take note that only brands that are authorised to use the Gorilla Glass trademark will be in the list. There might be chances where the device is using Gorilla Glass but you cannot find it there.