Flexible Substrate Receives Display Award

An inorganic-organic hybrid plastic substrate for flexible displays and electronics developed by the Industrial Technology Research Institute (ITRI) in Taiwan, billed as the first and only technology to allow for the mass production and development of flexible and transparent displays of any size, received the Society for Information Display's Silver Display Component of the Year Award on Wednesday.

The team at Taiwan's Industrial Technology Research Institute, which won a Silver Display Component of the Year Award from the Society for Information Display for its hybrid plastic substrate for flexible displays and electronics. (Photos: ITRI).

"Resolving the challenges associated with flexible displays has been at the forefront of the electronic and material development industry for the past few years," said Dr. Jia-Ming Liu, deputy general director of ITRI's Material & Chemical Research Labs. "I am very proud of our team for developing this breakthrough technology and anticipate that major consumer electronic manufacturers will be interested in applying this material to their products."

The flexible display market predicted to surge from $280 million in 2010 to $5.9 billion in 2015 and $12.2 billion by 2017, according to a Display Bank report.

But for the market to grow, first manufacturers have to overcome such problems as overheating and cloudiness. Fabricating transistors on flexible display substrates requires high temperatures. However, when made on a soft substrate of plastic material (PEN/PES), the transistors couldn't withstand temperatures ranging from 200-300 °C and were easily destroyed. Additionally, the transistors excessively shifted in position due to the plastics' high thermal expansion coefficient, exacerbating the problem.

To fix the problem, some researchers added approximately 30 percent of heat-resistant inorganic materials to the existing material to improve the substrate's heat resistance. But it turned the substrate yellow and cloudy, making the display less clear and bright.

ITRI developed a unique process to combine the inorganic materials with the traditional organic materials. The researchers positioned the inorganic materials at the base of the substrate and then added the organic materials, which successfully increased the proportion of silicon dioxide in the inorganic material from 20 to 40 percent up to 60 percent.

ITRI's flexible substrate for displays is the first and only technology to allow for the mass production and development of flexible and transparent displays of any size, the institute said.

This process greatly reduces the thermal expansion of the flexible transparent substrate under high-temperature conditions of up to 300 °C, and also makes the substrate highly transparent so that the display is very clear, not yellow and cloudy. The process is also compatible with existing thin-film transistor (TFT) processes and can be manufactured with either batch-type or roll-to-roll processes, ITRI said.

For batch-type processes, the substrate is prepared by coating the PI solution on glass carriers, and then fabricating TFT devices on the substrates. The PI/silica film exhibits excellent adhesion with silicon dioxide, silicon nitride and indium-tin-oxide without requiring any other primer or surface treatment process, ITRI said.

For roll-to-roll processes, the substrate can be made with a variety of attractive properties, such as a low coefficient of thermal energy (CTE) of 20 ppm/ºC, high transmittance (90.2 percent, within the wavelength range of 400-700 nm) and excellent flexibility. To date, a flexible color filter, an active-matrix electrophoretic display (AM-EPD) and a flexible touch film have been made on the flexible substrate, ITRI said

The Display of the Year (DYA) awards, widely considered the most prestigious in the display industry, were presented this week at the 49th annual Society for Information Display International Symposium, Seminar and Exhibition, dubbed Display Week 2011. The DYAs are awarded each year with Gold and Silver honors in three categories: Display of the Year, Display Application of the Year, and Display Component of the Year. This year's winners include Apple, Samsung and E Ink; ITRI is the only research institute to receive an award.

For more information, visit: www.itri.org.tw/eng