PPG has been working with other companies to develop silver nano-wire coatings – and, in some cases, developed complimentary coatings technologies to further enhance the AgNW coatings.

The Pittsburgh, PA-based company recently developed a silver nano-wire based patterning paste, which was shown at the South China Touch Panel and Display show in November 2017 and SID’s Display Week in May. It will be featured again at PPG’s booth at IDTechEx.

“This is a screen printable ink, that when printed in a selective pattern on AgNW coatings or film, it effectively disables the AgNW conductivity just in the areas where printed,” said John M. Yundt, PPG’s global business manager, EM-Conductive Materials. “This is an exceptional advantage in that is drastically reduces the time and cost involved in patterning the AgNW when used as a transparent conductive electrode for various touch panel applications. 

“Normally, companies would use photo-etch resist or a laser ablation to cut the AgNW coating for patterning,” he continued. “Our process is fast, inexpensive and being water-soluble, very environmentally friendly. In addition, PPG’s spray applied Transparent Functional Coatings for Anti-Fingerprint, Anti-Glare, Easy-Clean, and Anti-Reflection were introduced to the Touch Panel and Display industries in 2014, and have already become extremely popular alternatives to the traditional dry film, vapor deposited technologies previously available. These coatings have equal performance attributes in most applications, with superior throughput and drastically reduced production and application costs.”

Though PPG is not developing these nano-wires, Yundt said he’s “learned quite a bit” in the process. That includes key advantages of silver nano-wires compared to ITO, as well as other alternatives to ITO, such as the ability to use screen printing. 

“One of the most important advantages of AgNW over sputtered ITO, is a combination of improved conductivity, with comparable optical properties, and improved durability and flexibility, at a combined reduced overall cost versus ITO,” Yundt said. “When comparing to other ITO alternatives, AgNW may fall short in areas like ohms/sq., but the optical property advantage over metal mesh is maintained, as is the overall applied cost.”

The primary markets for this technology “tend to be” in mid-sized to larger tablets, laptop touch panels, as well as foldable or flexible displays, according to Yundt.

“And in all cases where the AgNW coated films hold advantages, the ability to use our unique pattering paste technology only enhances those advantages,” he added.