In order to provide a low-cost large substrate for full multi-bubble-jet head,
a method for manufacturing an ink-jet head in which ink-discharge-pressure generation
elements are provided on a substrate, discharge ports are disposed in a plate facing
the ink-discharge-pressure generation elements, and ink is discharged from the
discharge ports by generating bubbles within ink includes the steps of forming
a threaded port, serving as an ink supply port, in a ceramic substrate, filling
the threaded ports with a filler by melting the filler, flattening a portion of
the threaded port filled with the filler in the substrate, depositing a silicon
nitride film on the surface of the substrate in which the portion of the threaded
port is flattened, depositing a layer made of a high-heat-conduction material on
the silicon nitride film, forming the ink-discharge-pressure generation elements
on the high-heat-conduction layer, forming ink discharge portions having the corresponding
discharge ports on the substrate having the ink-discharge-pressure generation elements,
and removing the filler from the substrate having the ink discharge portions.
