Patent ID: 7713576

Claim:
A method of producing a piezoelectric ceramic thick film on a substrate, said method comprising: mixing liquid phase precursors of Li 2 O and Bi 2 O 3 metal oxides to form a Li—Bi solution; forming a suspension of a piezoelectric ceramic material in powder form and a fluid medium by ultrasonic vibration; forming a liquid mixture by mixing the suspension of powdered material with the Li—Bi solution, the Li 2 O and Bi 2 O 3 having melting points lower than a temperature required for densifying the piezoelectric ceramic thick film by sintering, said liquid mixture obtained by mixing the suspension of powdered material and the Li—Bi solution having a greater degree of homogeneity than that of a mixture obtained by mechanically mixing the powdered material; drying the liquid mixture to form a dried precipitate; milling the dried precipitate to form a powdered precipitate; adding an organic carrier to the powdered precipitate; further milling the powdered precipitate to form a paste; depositing a layer of the paste, as a wet film, onto the substrate; and annealing the substrate with the film at a temperature and for a time sufficient to cause transformation of the paste into the thick film.