Patent ID: 7163278

Claim:
An ink-jet printhead, comprising: a substrate having an ink chamber to be filled with ink to be ejected formed in an upper portion thereof and a manifold for supplying ink to the ink chamber formed in a lower portion thereof; a nozzle plate formed on the substrate, the nozzle plate including a plurality of passivation layers formed of an insulating material, a heat dissipation layer formed on the plurality of passivation layers and made of a metallic material having good thermal conductivity, and a nozzle passing through the nozzle plate and in flow communication with the ink chamber; a first and a second heater and a first and a second conductor, which are interposed between adjacent layers of the plurality of passivation layers of the nozzle plate and symmetric with respect to the nozzle, the first and second heaters for heating ink filled in the ink chamber and the first and second conductors for applying a current to the first and second heaters; and a first and a second ink channel, which are interposed between the ink chamber and the manifold, for providing flow communication between the ink chamber and the manifold, the first and second ink channels being symmetric with respect to the nozzle.