High resolution long array thermal ink jet printhead fabricated by anisotropic wet etching and deep Si RIE

A thermal ink jet (TIJ) printhead suitable for high speed and high quality printing has been developed. The printhead has been fabricated by dicing the bonded wafer, which consists of a bubble generating heater plate and a Si channel plate. The Si channel plate consists of an ink chamber and an ink inlet formed by KOH etching, and a nozzle formed by ICP RIE. The nozzle formed by ICP RIE has squeezed structures, which contribute to high-energy efficiency of drop ejector and therefore successful ejection of small ink drop. These two wafers are directly bonded by using electrostatic bonding of full-cured polyimide to Si. With these technologies, we have fabricated a 1" long printhead with 832 nozzles having 800 dots per inch (dpi) resolution and a 4 pl. ink drop volume.