Tomonori Minegishi

Stretchable insulating material for IoT devices

This paper reports a newly developed UV-curable and film-shaped insulating material for IoT devices that require stretchability. The material features large stretch ability, high transparency, low moisture permeability and good embedding property. An availability of the material for the stretchable devices was demonstrated through prototyping a test model and its evaluation. The good result of stretching and bending test showed that the developed material has large potential for the stretchable circuits and devices application.

Development of low CHE, negative-tone, photo-definable polyimide for HDD suspension

A negative-tone photo-definable polyimide with a low CHE has been developed for coating suspension heads in HDD applications. In order to select the low CHE polyimide, the stabilization energy of hydration calculated from the polyimide and water by Gaussian 03 was used as an indicator. A good correlation between the stabilization energy and CHE value of the polyimide was obtained and which resulted in the development of a low CHE, negative-tone, photo-definable polyimide. The developed material has a low CHE of 9 ppm/%RH, a CTE of 17 ppm/°C (matching that of stainless steel) and good lithographic properties.