Patent ID: 7347538

Claim:
A method for manufacturing a discharge head having a piezoelectric body which applies a discharge pressure to a droplet of liquid discharged onto a discharge receiving medium, the method comprising: a piezoelectric film forming step of forming a film of a piezoelectric body onto at least one surface of a base substrate, by means of a thin film forming technique; a heat treatment step of sintering the piezoelectric film by heat treatment, at least one of during formation of the piezoelectric film in the piezoelectric film forming step, and after formation of the piezoelectric film; a diaphragm forming step of forming a diaphragm by at least one of bonding and film deposition onto a surface of the piezoelectric body on an opposite side to the base substrate, after the piezoelectric body has been formed by the piezoelectric film forming step and the heat treatment step; a pressure chamber forming step of forming pressure chamber walls on a surface of the diaphragm on an opposite side to the piezoelectric body; a discharge hole plate bonding step of bonding a discharge hole plate formed with discharge holes which discharge the liquid held in pressure chambers, onto the pressure chamber walls; and a base substrate removing step of removing at least a portion of the base substrate, wherein a ratio b/a between a coefficient of thermal expansion, a, of the base substrate and a coefficient of thermal expansion, b, of the piezoelectric body is within a prescribed range, to prevent warping of the base substrate during the heat treatment step.