Unit cell for thermal inkjet printhead

Abstract

A unit cell for a thermal inkjet printhead includes a substrate portion that defines an ink supply passage; drive circuitry and interconnect layers positioned on the substrate portion; a nozzle plate defining a nozzle; side walls depending from the nozzle plate and positioned on the substrate portion to define an ink chamber; and a heater element connected to the drive circuitry and positioned intermediate the nozzle plate and the substrate portion, the heater element being suspended in the ink chamber in alignment with the nozzle and being shaped to be symmetrical about two planes that intersect along an axis extending through a centre of the nozzle. The drive circuitry is partially on one side of the ink chamber with a remainder of the drive circuitry on an opposite side.

Dependencies are inferred from the claim text.