Patent ID: 6952873

Claim:
A method of producing an ink jet recording head, comprising: forming an ink reservoir in an ink passage plate having a first surface and a second surface opposite to the first surface by forming a through hole in the ink passage plate so that the through hole extends from the first surface to the second surface, the ink passage plate comprising a metal sheet having the first surface and the second surface; pressing the first surface of the metal sheet to form recesses defining pressure producing chambers in the first surface of the ink passage plate; flattening the first surface of the metal sheet to remove slightly protruded portions formed on the first surface of the metal sheet during said pressing; superposing a nozzle plate having a plurality of nozzles, the ink passage plate, and a cover plate so as to form an ink passage unit said superposing including closely joining the cover plate to the first surface of the ink passage plate, wherein the ink passage unit includes the pressure producing chambers communicating with the ink reservoir through a plurality of ink inlet ports; and providing a pressure generator for applying pressure to ink in the pressure producing chambers of the ink passage unit.