Piezoelectric laminate and method of manufacture

US5036241A · kind A · utility

Assignee

• Xaar Limited · GB

Inventors

• A. John Michaelis · Glen Ellyn, US
• A. David Paton · Cambridge, GB

Key dates

• Filing date: Feb 3, 1989
• Grant date: Jul 30, 1991
• Expiry date: Feb 3, 2009

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10N30/045

Abstract

A piezoelectric laminate comprises a piezoelectric layer and an insulating substrate layer rigidly bonded thereto. During poling, conditions are established under which a poling potential is established at the boundary of the layers which insures that a substantial part of the poling voltage is dropped across the piezoelectric layer. The poling voltage is maintained for a period greater than the time constant under the poling conditions of the material to which the poling voltage is applied. In one embodiment, the poling conditions are achieved by substantially enhancing the conductivity of the substrate layer relative to that of the piezoelectric layer. In a second embodiment, an intermediate bond layer is selectively switched from a non-conductive to a conductive state in response to a selected stimulus so as to form an electrode for facilitating the application of a poling field directly across the piezoelectric layer.