Printing Technology Forms Electronic Circuit Directly on Curved Surface

2014/07/20 06:37
Tetsuo Nozawa, Nikkei Electronics
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Shizuo Tokito, vice director of Research Center for Organic Electronics (ROEL), Yamagata University, announced technologies being developed by his team at a seminar called "Thinking About Future of Organic Electronics" July 11, 2014.

Among the technologies, the "technology to print electronic circuits on 3D curved surfaces (3D-PE)" has not been researched by anyone, he said.

Tokito delivered a lecture on (1) the technology to form organic electronic circuits by using only printing technology, which his team has been developing, and (2) future development of the "smart organic sensing system" using the technology. In the lecture, he revealed the properties of silver (Ag) and copper (Cu) nanoinks supporting low-temperature firing. Yamagata University owns patents for the nanoinks.

The electric conductivity of the Ag nanoink lowers to about 200μΩcm just by drying the nanoink for a few hours at room temperature after applying the nanoink. When it goes through a firing process at a temperature of 100°C, the conductivity lowers to 6μΩcm. When the temperature is 120°C, the conductivity lowers to 3μΩcm.

Also, the research team developed a technology to lower the conductivity of the Cu nanoink to about 100μΩcm with a firing process in a nitrogen atmosphere at a temperature of 300°C and to about 18μΩcm at a temperature of 350°C. The conductivity of Cu in bulk is 1.7μΩcm.

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