Ink-jet printhead and manufacturing method thereof

A method of manufacturing an ink-jet printhead, the method comprising:

• forming a nozzle plate having a stack on a first portion of a substrate;
• forming a heater disposed in the stack and having a center axis, and forming an interconnection layer connected to the heater;
• forming a well having a predetermined diameter and depth in the substrate and the nozzle plate along the center axis;
• forming a cylindrical bubble guide having a predetermined thickness on an inner wall of the well to define a nozzle through which ink is ejected;
• filling the well with photoresist to form a sacrificial layer;
• forming a hydrophobic coating layer on the nozzle plate and an entire top surface of the sacrificial layer;
• forming a droplet ejecting portion that has a through-hole shape having a diameter smaller than that of the bubble guide and has the same axis as the bubble guide, on the hydrophobic coating layer;
• injecting an etchant toward the sacrificial layer through the droplet ejecting portion to remove the sacrificial layer from the well;
• injecting the etchant via the bubble guide into the well to form an ink chamber having a predetermined volume around and under the bubble guide by etching the substrate using the etchant;
• and
• forming an ink supplying passage which communicates with the ink chamber, on a second portion of the substrate.

A method of manufacturing an ink-jet, the method comprising:

• forming a nozzle plate having a heater on a first portion of a substrate;
• forming a well having a center axis on the nozzle plate and the substrate;
• forming a cylindrical bubble guide having the center axis on a surface of the well to define a nozzle;
• filling a space defined by the cylindrical bubble guide with a material to form a sacrificial layer;
• forming a hydrophobic coating layer on the nozzle plate and the sacrificial layer;
• forming a hole in a portion of the hydrophobic coating layer corresponding to the sacrificial layer to form a droplet ejecting portion having the center axis;
• removing the sacrificial layer from the space through the droplet ejecting portion;
• and
• forming an ink chamber having the center axis in the first portion of the substrate to communicate with the nozzle, forming a manifold on a second portion of the substrate, and forming a passage between the manifold and the ink chamber.

An ink-jet printhead comprising:

• a substrate having an ink chamber formed on a first surface of the substrate and having a center axis, and having a passage formed on second surface of the substrate to supply ink to the ink chamber;
• a nozzle plate having a heater, a well formed on an inside portion of the heater and having a center axis, an inside layer facing the substrate, and an outside layer formed on the inside layer;
• a bubble guide formed on a surface of the well of the nozzle plate and extended from the well of the nozzle plate toward an inside of the ink chamber to define a nozzle communicating with the ink chamber;
• a hydrophobic coating layer formed on the outside layer of the nozzle plate;
• and
• a droplet ejecting portion formed on the hydrophobic coating layer and having an area less than that of the bubble guide in a direction perpendicular to the center axis.

An ink-jet printhead comprising:

• a substrate having an ink chamber formed on a first surface of the substrate and having a center axis, and having a passage formed on second surface of the substrate to supply ink to the ink chamber;
• a nozzle plate having a heater, a well formed on an inside portion of the heater to define a hole having the center axis, an inside layer facing the substrate, and an outside layer formed on the inside layer;
• a bubble guide formed on the well of the nozzle plate and extended from the well of the nozzle plate toward an inside of the ink chamber, defining a nozzle communicating with the ink chamber, and having an inlet portion disposed in the ink chamber and an outlet portion disposed adjacent to the well of the nozzle plate;
• and
• a droplet ejecting portion formed on the outlet portion of the bubble guide so that the nozzle narrows from the inlet portion to the outlet portion.