Patent ID: 7686429

Claim:
An ink jet printhead comprising: a plurality of nozzles; a heater associated with each of the nozzles respectively, the heater having a heater element and a pair of electrodes, the heater element configured for thermal contact with a bubble forming liquid and the electrodes configured for connection to an electrical power source; such that, heating the heater element above the boiling point of the bubble forming liquid forms a gas bubble that causes the ejection a drop of ejectable liquid from the nozzle; wherein the heater is formed by layers of a single material such that the heater element and electrodes are formed of the same material, a first layer of the single material heater layers having portions of different thickness respectively defining the heater element and electrodes, and a second layer of the single material heater layers overlaying and spaced from the first layer not having the heater element and having a single thickness defining the electrodes.