Abstract: Piezoelectric transformers have a number of favorable characteristics over traditional electromagnetic tranformers. However, the construction of piezoelectric transformers tends to be complicated, which may result in increasing manufacturing cost. Furthermore, such complex constructions may raise difficulties in the miniaturization of such devices. A ring-shaped piezoelectric transformer is developed in this invention for low voltage applications. One surface of the transformer is covered by two disc or ring-shaped electrodes separated by a ring-shaped separating segment, and the regions covered by the disc or ring-shaped electrodes served as the input and output parts of the transformer. This transformer may be fabricated relatively easily due to its simple structure. Furthermore, its size and thickness may be reduced relatively easily without increasing the difficulty of the fabricating process. The transformer may be used separately or in parallel.

Abstract: Piezoelectric transformers have a number of favorable characteristics over traditional electromagnetic tranformers. However, the construction of piezoelectric transformers tends to be complicated, which may result in increasing manufacturing cost. Furthermore, such complex constructions may raise difficulties in the miniaturization of such devices. A ring-shaped piezoelectric transformer is developed in this invention for low voltage applications. One surface of the transformer is covered by two disc or ring-shaped electrodes separated by a ring-shaped separating segment, and the regions covered by the disc or ring-shaped electrodes served as the input and output parts of the transformer. This transformer may be fabricated relatively easily due to its simple structure. Furthermore, its size and thickness may be reduced relatively easily without increasing the difficulty of the fabricating process. The transformer may be used separately or in parallel.

Abstract: A bonding tool has a driver of piezoelectric elements in a stack. A sensor is positioned and held in the stack and includes a piezoelectric element sandwiched between electrodes and insulating wafers. Voltage developed between the electrodes is monitored and used to determine a bonding parameter, including the amplitude and duration of each ultrasonic burst.

Abstract: A bonding tool for applying pressure and ultrasonic energy simultaneously to join miniature components together includes an ultrasonic driver having four composite wafers separated by electrodes. Such bonding tools are known that use wafers made of wholly of ceramic material. By using wafers having four sector parts of ceramic material separated by layers of polymer as shown, bonding tools are provided with broader bandwidth operation and reduced spurious resonance modes.