Inkjet printhead and method of manufacturing the same

A method of manufacturing an inkjet printhead, the method comprising:

• forming a heater to heat ink and an electrode to supply current to the heater on a substrate;
• coating a first negative photoresist composition on the substrate on which the heater and the electrode are formed, and patterning the first negative photoresist composition by photolithography to form a passage forming layer that defines an ink passage;
• forming a sacrificial layer on the substrate on which the passage forming layer is formed to cover the passage forming layer;
• planarizing top surfaces of the passage forming layer and the sacrificial layer by a polishing process;
• coating a second negative photoresist composition on the passage forming layer and the sacrificial layer, and patterning the second negative photoresist composition by photolithography to form a nozzle layer having a nozzle;
• forming an ink supply hole in the substrate;
• and
• removing the sacrificial layer,
• wherein the first and second negative photoresist compositions are each independently negative photoresist compositions comprising:
• a bisphenol-A-based prepolymer having oxytein functional groups on repeating units thereof,
• a cationic photo initiator,
• and a solvent.

An inkjet printhead manufactured by a method of manufacturing an inkjet printhead using a negative photoresist composition comprising a bisphenol-A-based prepolymer having oxytein functional groups on repeating units thereof, the method comprising:

• forming a heater to heat ink and an electrode to supply current to the heater on a substrate;
• coating a first negative photoresist composition on the substrate on which the heater and the electrode are formed, and patterning the first negative photoresist composition by photolithography to form a passage forming layer that defines an ink passage;
• forming a sacrificial layer on the substrate on which the passage forming layer is formed to cover the passage forming layer;
• planarizing top surfaces of the passage forming layer and the sacrificial layer by a polishing process;
• coating a second negative photoresist composition on the passage forming layer and the sacrificial layer, and patterning the second negative photoresist composition by photolithography to form a nozzle layer having a nozzle;
• forming an ink supply hole in the substrate;
• and
• removing the sacrificial layer,
• wherein the first and second negative photoresist compositions are each independently negative photoresist compositions comprising:
• the bisphenol-A-based prepolymer having oxytein functional groups on repeating units thereof,
• a cationic photo initiator,
• and a solvent.

An inkjet printhead, comprising:

• a chamber layer to define an ink passage, the ink passage defining a plurality of ink chambers and restrictors;
• and a
• nozzle layer defining a plurality of nozzles, the nozzles disposed to correspond to the plurality of ink chambers,
• wherein the chamber layer and the nozzle layer are each independently formed of a negative photoresist comprising:
• a bisphenol-A-based prepolymer having oxytein functional groups on repeating units thereof,
• a cationic photo initiator,
• and a solvent.