Patent ID: 6432238
Filing Date: 2002-08-13
Classification: H01L

Abstract:
A method for fabricating a piezoelectric/electrostrictive thick film, using a seeding layer, comprising the steps of:providing a substrate; forming on the substrate the seeding layer from a first ceramic sol solution or a ceramic paste, wherein the first ceramic sol solution or ceramic paste comprises at least one component comprised in the piezoelectric/electrostrictive film, said ceramic paste being prepared from a mixture of a ceramic oxide powder, which has a particle size of 5 &mgr;m or less and is prepared from Pb and Ti-based piezoelectric elements by a non-explosive oxidation-reduction combustion reaction at 100-500Â° C., and a second ceramic sol solution in water or an organic solvent, wherein the second ceramic sol solution comprises at least one component comprised in said ceramic oxide powder; subjecting the seeding layer to an after-treatment to improve the reactivity of the seeding layer and to prevent undesirable reaction between the seeding layer and the substrate; forming a piezoelectric/electrostrictive film on the seeding layer to a desirable thickness; and thermally treating the piezoelectric/electrostrictive film and the seeding layer at 100-600Â° C. to sinter the seeding layer and the piezoelectric/electrostrictive film and to solidify the bonding between the film and the substrate; whereby the piezoelectric/electrostrictive thick film is allowed to show a superb bonding to the substrate in the low temperature thermal treatment wherein said after-treatment includes a drying process carried out by drying said seeding layer in a drying chamber saturated with the vapor of an organic solvent and volatilizing the solvent at a proper temperature from the seeding layer, said organic solvent being identical to that used to prepare The ceramic sol for the seeding layer.