Inkjet printhead and method of producing the same

An inkjet printhead comprising a cavity unit formed by laminating a plurality of plates which include a first plate through which a plurality of through-holes are formed, and a second plate laminated on one surface of the first plate, the cavity unit having:

• a common ink chamber accommodating ink;
• a plurality of pressure chambers to which the ink is distributed from the common ink chambers
• a plurality of nozzles which are communicated with the respective pressure chambers, and through each of which a droplet of the ink is ejected;
• and
• a plurality of connecting passages connecting the common ink chamber with the respective pressure chambers, a part of each of the connecting passages being constituted by a groove formed along the one surface of the first plate and open in the one surface, an open end of the groove being covered by the second plate, and one of opposite ends of the groove being connected to the through-hole, the groove including:
• an orifice portion at which a cross-sectional area of the connecting passage as taken in a direction perpendicular to a direction of flow of the ink is minimized in the connecting passage;
• and
• an enlarged portion continuously interposed between an end of the orifice portion and an open end portion of the through-hole, the cross-sectional area of the connecting passage being larger at the enlarged portion than at the orifice portion.