Method of fabricating ink jet printheads

Abstract

A plurality of ink jet printheads are produced from two aligned and bonded substrates by an improved fabrication method. The confronting surface of one of the substrates contains a plurality of linear arrays of heating elements and driver circuitry, and the confronting surface of the other substrate contains a plurality of sets of shallow channel recesses, reservoir recesses, and alignment openings. Prior to mating of the substrates, the substrate surface having the channel recesses is coated with a layer of thermosetting adhesive, and a thick film layer is deposited on the substrate surface having the heating elements and driver circuitry and patterned to provide a plurality of vias therein at predetermined locations. The vias expose the heating elements, provide ink bypass trenches, and provide a number of groupings of small pits. In one embodiment, the alignment openings are used to visually align and mate the substrates, so that each alignment opening is aligned with a respective one of the groups of small pits in the thick film layer. To prevent misalignment between the substrates before the adhesive layer is cured, a UV curable adhesive is inserted into the alignment openings and into each group of small pits in the thick film layer aligned therewith and cured, thus fastening the substrates together. The fastened substrates are placed in a curing oven without lost of alignment therebetween and the thermosetting adhesive is cured. The bonded substrates are then diced into a plurality of individual printheads.