Piezoelectric film sonic emitter Patent #: 6011855
ApplicationNo. 537199 filed on 03/28/2000
US Classes:29/25.35, PIEZOELECTRIC DEVICE MAKING310/328, With mechanical energy coupling means310/800, PIEZOELECTRIC POLYMERS (E.G., MYLAR, PVDF)381/114, With piezoelectric microphone381/190Electrostrictive, magnetostrictive, or piezoelectric
ExaminersPrimary: Hall, Carl E.
Attorney, Agent or Firm
International ClassH01L 041/00
AbstractA method of forming an ultrasound transducer having thermoformed protuberances comprises providing a substrate having a plurality of perforations of a given dimension. The perforations or apertures are formed in the substrate and operate to determine the resonance frequency associated with the transducer. A film of polymeric material capable of showing piezoelectric properties when strained in its plane and electrically biassed by a field applied in a direction normal to its faces, is then laminated onto the substrate. The film is heated to a given temperature and a pressure differential is applied between the top and bottom surfaces of the film for a sufficient time to form protuberances in the film through the apertures in the substrate. The film is then cooled to a given ambient temperature while maintaining a pressure differential between the top and bottom surfaces of the film for a sufficient time until the ambient temperature is reached so as to cause the protuberances to maintain a substantially permanent curvature.