Xerox Corporation

Igal E Klein

Cathie J Burke

Roberto E Proano

William G Hawkins

Robert V Lorenze, Jr

Daniel O Roll

Renato P Apollonio

In a thermal ink jet printhead with a protective layer, the protective layer is made of a thin film material having a melting point not less than about 1000.degree. C. A deposition process for preparing the thin film material produces a thin film material having, at an operating temperature for the thermal ink jet printer, a thermal conductivity coefficient not less than about 10 W/m.K, a compressive yield strength not less than about 1400 MPa, and a compressive residual stress of not greater than about 1200 MPa. The protective layer is smooth, substantially free of pores and impervious to stress corrosion or hydrogen stress cracking at a hydrogen uptake rate of less than about 5 ppm. The protective layer may also contain an adhesion enhancing region between the protective layer and an underlying layer or an anodic region contiguous with an underlying thin film material of the protective layer. The adhesion enhancing region is a reaction product between an ambient gas and the thin film material of the protective layer and extends only to the grain boundaries of the protective layer. The contiguous anodic region is substantially free of pores, has a homogeneous composition, protects an underlying thin film material against corrosive species and hydrogen and is formed by anodization of the underlying thin film in an aqueous electrolytic process.

Thermal ink jet printhead protective layers

A thermal ink jet printhead has an outer, metallic hydrophobic coating on its front face to repel ink. Eliminating the accumulation of ink at the nozzles of the printhead allows an ink droplet to be accurately ejected and ensures the directionality of the ejected ink droplet onto the printing medium. The outer coating is formed of a metal selected from the group of noble metals, including gold, platinum, palladium, silver, rhodium and ruthenium. An adhesion layer is preferably deposited between the front face of the printhead and the outer ink-repellent coating. The metallic coating is preferably applied by electroplating, wet electroless plating, evaporation, sputtering, ion plating, CVD or plasma CVD.

Directionality of thermal ink jet transducers by front face metalization

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Karmiel, Israel

Igal E Klein