Self-aligned construction and manufacturing process for monolithic print heads

Abstract

A manufacturing process for printing heads which operate using the coincident forces drop on demand printing principles. The print head integrates many nozzles into a single monolithic silicon structure. Semiconductor processing methods such as photolithography and chemical etching are used to simultaneously fabricate a multitude of nozzles into the monolithic head. The nozzles are etched through the silicon substrate, allowing two dimensional arrays of nozzles for color printing. The manufacturing process can be based on existing CMOS, nMOS and bipolar semiconductor manufacturing processes, allowing fabrication in existing semiconductor fabrication facilities. Drive transistors, shift registers, and fault tolerance circuitry can be fabricated on the same wafer as the nozzles. The manufacturing process uses anisotropic wet etching using KOH on a (110) wafer to form ink channels with vertical side-walls. Nozzle barrels are formed using the same etching process, using boron as an etch stop. The etching follows the crystallographic planes of the silicon, which result in highly accurate and consistent etch angles using simple etching equipment. Wafer alignment to the (110) crystallographic plane is only required to be to the standard .+-.1.degree..

Dependencies are inferred from the claim text.