The origins of flexible displays can be traced back to the ’70s. Though there have been many breakthroughs since then, it was only recently that this technology began to see consumer adoption for mass production.
Currently, 90% of displays sold today are made with glass. These designs are based on liquid crystal displays (LCD). Flexible displays are often based on organic light-emitting diode (OLED) technology, which is fundamentally different than LCD.
So, how does this technology flex and fold? Below, we explore how to create flexible displays using OLED over LCD.OLED vs. LCD
The most basic difference between LCD and OLED displays is that each sub-pixel is self-emissive in OLED. Instead of using a backlight to illuminate its pixels (like LCDs do), OLED pixels actually produce their own light. Thus, the display is much thinner and lighter than a LCD.
Thin-film transistors are used to turn each pixel on and off. Inorganic semiconducting materials, such as amorphous silicon, indium gallium zinc oxide (IGZO) or low-temperature polycrystalline silicon (LTPS), require process temperatures above 300 ̊C. However, organic thin-film transistors (OTFTs) can often be fabricated at temperatures around 150 ̊C or less. Low-processing temperatures allow OTFTs to be fabricated on inexpensive substrates like plastic rather than glass. This brings significant manufacturing benefits for flexible displays.
An additional advantage of plastic flexible displays is durability. Because the screen can flex and fold, it can also absorb impact better than glass. In order for the display to be truly flexible all the materials used in the display must not break down under repeated stress—keeping a consistent image on the screen. Promerus has a variety of materials that can be utilized in flexible displays.
Take PDM-5004, for example. This formulation contains norbornene monomers that are coated directly onto a substrate. During thermal cure, the monomers are polymerized in place, solidifying into a permanent material, with features of a thermoset. When blended with additives, it can be designed to have excellent adhesion and mechanical durability. This makes PDM-5004 an ideal solution for flexible electronic applications.
Promerus manufacturers a variety of electronic materials and is actively developing new ones. These materials are based on high-purity polymers that provide outstanding electrical, mechanical, thermal and optical properties in many packaging, sacrificial and photoresist applications. To see what Promerus can do for you, we encourage you to download our Materials Guide.