Kenji Ishizeki

57.4: Distinguished Paper: A Novel Hermetic-Sealing Material for FED

A hermetic-sealing material for FED composed of thermosetting polyimide and inorganic filler has been developed. This material enables us to seal at a temperature around 350 °C in nitrogen atmosphere and shows superior performance suitable for glass-to-glass and glass-to-metal sealing.

A novel hermetic-sealing material for FEDs

— An hermetic-sealing material for FEDs composed of thermosetting polyimide and glass fiber, has been developed. The main backbone and end-capping material of polyimide were investigated to satisfy both high Tg and high flowability. A thermosetting function, 4-phenylethynylphthalic anhydride (PEPA), was used as the end-capping material. The fracture of a rigid and softening structure was optimized in the main polymer structure. The obtained polyimide demonstrated both a high Tg (265°C) and low viscosity (98 Pa-sec at a sealing temperature of 350°C). In order to improve the gas permeability and the mechanical and thermal characteristics of the sealing material, a mixture of various types of ceramic fillers and polyimide has been investigated, and glass fiber was adopted. When 30 wt.% of glass fiber was combined when the developed polyimide, the Ar permeability and coefficient of thermal expansion of the sealing material decreased to below one-half of the base polyimide. This material enables us to seal at a temperature of about 350°C in nitrogen atmosphere and shows superior performance suitable for glass-to-glass sealing.