A method for manufacturing an ejection head (10) or ejector suitable for
ejecting in the form of droplets (16) a liquid (14) conveyed inside
the ejection head (10), comprising a step of producing, from a silicon wafer,
a nozzle plate (12) having at least one ejection nozzle (13); a step
of producing, from another silicon wafer, a substrate (11) having at least
one actuator (15) for activating the ejection of the droplets of liquid
through the nozzle (13); and a step of joining the nozzle plate (12)
and the substrate (11) together to form the ejection head, wherein this
joining step comprises the production of a junction (25), made by means
of the anodic bonding technology, between the substrate (11) and the nozzle
plate (12), in such a way that, in the area of this junction (25),
the ejection head (10) does not present structural discontinuities, and
also possesses a resistance to chemical corrosion by the liquid (14) contained
in the ejection head (10) at least equal to that of the silicon constituting
both the substrate (11) and the nozzle plate (12). The method of
the invention may be applied for manufacturing an ink jet printhead (110),
having one or more nozzles (113a, 113b, etc.), which
has the advantage, with respect to the known printheads, of also being suitable
for working with special inks characterized by high level chemical aggressiveness.
In general, the ejection head of the invention, thanks to its structure which is
globally highly robust and also chemically inert in the area of the junction (25),
can be used advantageously with various types of liquids, even with marked chemical
aggressiveness, in different sectors of the art, for example for ejecting paints
on various types of media, generally not paper, in the industrial marking sector;
or for ejecting in a controlled way droplets of fuel, such as petrol, in an internal
combustion engine.