Full-integrated hot ink-jet print head having silicophosphate glass layer with etched back

Application Number: 00108727
Application Date: 2000.05.26
Publication Number: 1286168
Publication Date: 2001.03.07
Priority Information: 1999/8/27 US 09/384814
International: B41J2/14
Applicant(s) Name: Hewlett-packarad Co.
Inventor(s) Name: N.A. Kavamura;C.C. Davies;T.L. Weber
Patent Agency Code: 72001
Patent Agent: cai minjun
Abstract Described herein is a monolithic printhead formed using integrated circuit techniques. Thin film layers (24, 40-50), including ink ejection elements (24), are formed on a top surface of a silicon substrate (20). The various layers are etched to provide conductive leads (25) to the ink ejection elements (24). A trench (36) is etched in the bottom surface of the substrate (20). An orifice layer (28) is formed on the top surface of the thin film layers to define the nozzles (34) and ink ejection chambers (30). A phosphosilicate glass (PSG) layer, providing an insulation layer beneath the resistive layers, is etched back from the ink feed holes and is protected by a passivation layer to prevent the ink from interacting with the PSG layer.