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Hitachi Chemical DuPont MicroSystems, Ltd. (hereinafter “the company”) announces that the company was granted permission to maintain the Japanese patents (Patent No. 6288227 and Patent No. 6206446; hereinafter “the patent group”) on polyimide precursor resin composition essential for manufacturing high heat-resistant, bendable flexible substrates on October 11 and November 25, respectively, in 2019 after examination by the Japan Patent Office in response to an opposition to the patent group filed by a third party.
The rapid growth of the Internet of Things (IoT) is expected to further expand the demand for flexible organic EL and Micro-LED display panels with the spread of bendable devices, including next-generation smartphones, e-Paper, and digital signage.
To manufacture flexible panels, plastic substrates are placed on glass substrates, with pixel circuits and display layers formed on top, while forming thin film transistors (TFT), one part of the pixel circuits, requires high temperature processing. However, this process could not be applied to conventional plastic substrates due to their poor heat resistance. Technologies previously used to tackle this problem involved the complicated process of forming TFTs on glass substrates, followed by separating the pixel circuits from the glass substrates and reforming them on plastic substrates. Flexible panel manufacturers had struggled to overcome this challenge for many years.
The company’s technology is related to liquid polyimide precursor resin composition for forming flexible device substrates that gives plastic substrates both toughness* and heat resistance. In addition to heat resistance, this technology offers solutions to realize the conflicting properties of “excellent adhesion to glass substrates while forming pixel circuits” and “easy release from glass substrates after forming pixel circuits,” thereby allowing flexible device substrates to be formed using a simpler and more efficient process.
The company will take full advantage of the patent group to actively promote external collaboration, including out-licensing.
*Material’s high viscosity or resistance to damage caused by external force