TOKYO – DuPont-Toray has filed a lawsuit in Tokyo District Court against Ube Industries for allegedly infringing a Japanese patent related to formulation and properties of polyimide film used in chip-on-flex circuits.
In its court filing, DuPont-Toray alleges Ube has infringed patent no. 4777471 covering Kapton polyimide film.
The firm says Ube manufactured and sold polyimide film graded as UPILEX SGAV1.