Method for manufacturing a micro-electromechanical nozzle arrangement on a substrate with an integrated drive circutry layer

1. A method for manufacturing a micro-electromechanical printer nozzle arrangement on a substrate having a layer of integrated drive circuitry, the method comprising the steps of:

etching a nozzle region through the layer of integrated drive circuitry up to the substrate;

etching electrical contact regions about the nozzle region;

depositing and etching metal and hydrophobic polymer layers on the layer of integrated drive circuitry so that the metal layer defines heater elements in electrical contact with the drive circuitry and embedded in a hydrophobic polymer structure disposed about the nozzle region;

etching a nozzle chamber in the substrate such that the nozzle chamber is in fluid communication with the nozzle region; and

back-etching the substrate to define an ink channel in fluid communication with the nozzle chamber so that the ink channel is positioned at an apex of the nozzle chamber.

2. A method as claimed in claim 1 , in which the step of depositing and etching the metal and hydrophobic polymer layers includes the step of etching the hydrophobic polymer layers to define:

a plurality of radially extending bridging portions which terminate in a common rim that defines an ink ejection port at the nozzle region, and

a plurality of actuators, defined by respective heater elements embedded in respective hydrophobic polymer structures, which are interposed between respective pairs of adjacent bridging portions and each terminate in a free end proximal to the rim.

3. A method as claimed in claim 2 , in which the step of depositing and etching the metal and hydrophobic polymer layers includes the steps of:

depositing a first hydrophobic polymer layer on the layer of integrated circuitry;

etching the first hydrophobic polymer layer to define via in register with the electrical contact regions;

depositing the metal layer to be in electrical contact with the via;

etching the metal layer to define the heater elements; and

depositing a second hydrophobic polymer layer on the metal layer.

4. A method as claimed in claim 3 , in which the step of etching the metal layer is carried out so that the heater elements each have a serpentine configuration.

5. A method as claimed in claim 2 , in which the step of:

etching the substrate to define the nozzle chamber is carried out so that the rim, bridging portions and actuators are superposed with respect to the nozzle chamber.

6. A method as claimed in claim 1 , in which the step of etching the nozzle chamber is performed as a crystallographic etch.