Patent ID: 7887160

Claim:
An inkjet printhead comprising: a wafer assembly defining an elongate ink supply channel and an ink inlet extending from the ink supply channel; a chamber roof layer supported by the wafer assembly, the chamber roof layer defining an elongate ink conduit and nozzle chambers, the ink conduit being in fluid communication with the ink supply channel and the nozzle chambers being in fluid communication with the ink conduit; a plurality of nozzle apertures defined through the chamber roof layer; a plurality of heater elements on a floor of each nozzle chamber; and a trench cut into the floor of each nozzle chamber in the vicinity of each heater element, the trench positioned with respect to the nozzle aperture to sandwich the heater element therebetween, whereby a level of the floor of the nozzle chamber in the vicinity of the heater element is lowered and ink supplied to the nozzle chamber immerses the heater element on both sides thereof, wherein the ink conduit is substantially in the same plane as the nozzle chambers, the plane being parallel to the chamber roof layer.