Patent ID: 7645026

Claim:
An inkjet printhead comprising: a wafer substrate; an array of ink chambers defined by sidewalls extending between a nozzle plate and the wafer substrate which is parallel to and spaced from the nozzle plate, each ink chamber having an elongate configuration with a longitudinal extent exceeding a lateral extent; a plurality of nozzles formed in the nozzle plate of each of the ink chambers respectively, the nozzles being spaced along the longitudinal extent of the ink chamber; a thermal actuator in each of the ink chambers respectively, each of the thermal actuators having an elongate heater element extending between two contacts, the elongate heater element being aligned with the longitudinal extent of the chamber; and, drive circuitry for selectively providing the actuators with drive signals such that the actuator simultaneously ejects ink through all the nozzles of the chamber, the drive circuitry having electrodes for electrical connection to each of the contacts respectively; wherein, the thermal actuators are unitary planar structures with the heater elements formed from elongate strips of heater material and the electrodes are exposed areas of a top-most metal layer of the drive circuitry, the ink chamber being configured such that the heater elements are suspended by the contacts in the ink chamber.