Patent ID: 7644479

Claim:
A method of producing a piezoelectric actuator comprising: a diffusion-preventive layer forming step of forming, on a substrate, a diffusion-preventive layer including a first diffusion-preventive layer having a melting-start temperature T M1 and a maximum shrink temperature T S1 , and a second diffusion-preventive layer having a melting-start temperature T M2 and a maximum shrink temperature T S2 ; a calcination step of calcinating the diffusion-preventive layer at a calcination temperature T C which satisfies a relationship of T M1 <T M2 <T C <T S1 , prior to forming a piezoelectric layer on the diffusion-preventive layer; a piezoelectric layer forming step of forming the piezoelectric layer on the diffusion-preventive layer; and an annealing-process step of annealing the piezoelectric layer at an annealing temperature T A which satisfies a relationship of T M2 <T A <T S2 .