Ink jet printhead having intergral silicon filter

Abstract

An ink jet printhead having an integral silicon filter over the printhead ink inlet is disclosed. The filter is produced by orientation dependent etching during printhead fabrication. The individual printheads are obtained by a sectioning operation which cuts aligned and bonded channel and heater wafers into a plurality of printheads. The channel wafer is orientation dependent etched from one side of a (100) silicon wafer through a patterned etch resistant mask layer to produce the plurality of reservoir recesses, each having a predetermined depth and floor thickness, and a plurailty of sets of parallel ink channel grooves, one set of channel grooves for each reservoir recess. The etch resistant mask layer on both sides of the channel wafer are removed and a second etch resistant mask layer is deposited thereon. The second mask layer on the side opposite the one with the channel grooves and reservoir recesses are patterned to produce a plurality of patterns of filter pore vias in alignment with the bottoms of the reservoir recesses. The printhead filters are produced by a second orientation dependent etching step of the channel wafer and prior to bonding to the heater wafer.