The Glass Inside
Most people realize that glass is used on the surface of their television, laptop, tablet, or smartphone, but did you know that glass plays an important role inside those devices? Glass enables many of the performance features today’s buyers demand – damage resistance; clear, vivid colors; quick, responsive touch; and extended usage time.
To understand how glass contributes to the protection and performance of your favorite devices, we need to look inside. Every television, computer, or mobile device can have multiple layers of glass inside and each layer has a specific task. The number and purpose of the layers varies according to the type of device, its features and functions, the type of display it contains, and the process used to make it.
The electronic devices you see and use every day – televisions, laptops, tablets, and smartphones – typically use either liquid crystal displays (LCDs) or organic light-emitting diode (OLED) displays. Both can deliver high performance, but each works in a unique way.
The fundamental difference between LCD and OLED display technologies is the light source. The light in a liquid crystal display comes from light-emitting diodes (LEDs) inside the device. These lights, sometimes called a backlight, are similar to those you see in popular LED flashlights. OLED displays do not need a separate light source in the device, because OLEDs emit their own light when charged by an electric current.
Both LCD and OLED displays contain multiple glass layers – though a slightly different combination – and a massive amount of transistors to provide sophisticated functionality.
Layers of Glass
So, what are the different layers, and how do they work together to improve the performance of your device? Two types of glass are in your device: cover glass, which helps protect the display on the exterior of your device, and substrate glass, which helps enable functionality inside your device. Both LCD and OLED displays can have as many as four different layers of glass:
Cover Glass – Cover glass is most commonly found on smartphones, tablets, notebooks, and other consumer electronic devices. It helps protect the device’s screen for both LCD and OLED displays. This outermost layer is the one you see and touch on a daily basis, so the look and feel of the glass also provides a sensory experience for the user. The cover glass needs to have a smooth surface for a pleasant touch response; exceptional optical clarity for a great look; and long-lasting toughness to help protect the device from everyday wear and tear.
Touch Sensor – Used when either LCD or OLED displays are touch-enabled, this substrate layer does just what it says – it senses the user’s touch and relays that information to the processer inside. The glass at the touch sensor layer must be thin to ensure sensitivity to contact, responsiveness, and accuracy. It’s located behind the cover glass, before the frontplane/color filter for LCDs or the encapsulation layer for OLEDs.
Frontplane/Color Filter (LCD only) – The frontplane/color filter layer sits behind the cover glass in standard LCDs or behind the touch sensor in touch-enabled LCDs. You look through the cover glass and touch sensor layers to see the vivid images created by a color filter in this substrate layer. Using pristine glass in the frontplane provides a near flawless, bright, and uniform digital image.
Encapsulation Glass (OLED only) – In OLED devices, this substrate glass encapsulates the organic light-emitting diodes and sensitive electronics deep inside the device. An airtight (hermetic) seal keeps damaging moisture and oxygen from reaching the interior components.
Backplane – The innermost piece of substrate glass in a device, the backplane is the powerhouse for both LCDs and OLEDs. It houses millions of semiconductor transistors that set the rules for light to pass or not pass through each pixel. The organic material, which generates the colored lights of an image, is located here in OLED devices.
Working together, these glass layers create resilient, responsive devices with vivid displays. But, this is not ordinary glass – it is advanced glass, specially formulated and manufactured to be ideally suited for today’s electronics. Because even minor imperfections can spoil your images, these displays must have a near-perfect surface. The material must be durable and have uniform quality throughout to provide reliability and high-performance.
Crafted using a proprietary fusion process, Corning’s advanced glass supports the intricate layers of microelectronics and components working inside and delivers a highly responsive and engaging user experience. For more than 160 years, Corning has leveraged a deep knowledge of glass properties with engineering and manufacturing expertise to answer the needs of the growing consumer electronics market and enable future innovations.