Abstract: Ultrasonic transducer apparatus for cleaning applications and method for cleaning wafers of semiconductor material in which the method includes positioning the wafer proximate to but closely spaced away from a cleansing face of the ultrasonic transducer, supplying space between the cleansing face and the wafer with a cleansing fluid through an orifice in the cleansing surface and ultrasonically vibrating the cleansing face transversely to the wafer by applying an electrical signal to piezoelectric material symmetrically disposed about the orifice in the cleansing face via which the cleansing fluid is supplied, with the ultrasonic transducer including piezoelectric material symmetrically disposed with respect to the orifice in the cleansing face through which the cleansing fluid is supplied.

Abstract: This method provides methods and apparatus for programmably regulating power provided to ultrasonically vibrate a metal-cutting tool, with power being regulated as a function of physical parameters measured during the cutting operation which are indicative of progress of the tool cutting the workpiece. The methods and apparatus regulate the power input to vibrate the tool in response to one or more sensed physical parameters to maintain the parameter(s) within preselected limits indicative of satisfactory cutting by the tool.

Abstract: An ultrasonic spot welder is disclosed with a reed of resonant length arranged to be vibrated in a flexural mode for spot welding both plastics and metals. The reed has a non-circular cross section with major and minor transverse dimensions. Vibratory energy is transmitted to the reed in a direction perpendicular to its major transverse dimension.