Piezocomposite ultrasonic transducer for high-frequency wire-bonding of microelectronics devices

Piezocomposite ultasonic transducers for high-frequency microelectronics wire bonding have been developed to alleviate the intrinsic mode coupling and high mechanical quality factor (Qm) in piezoceramic transducers. In this paper, a 136 kHz transducer fabricated using lead zirconate titanate (PZT)/epoxy 1–3 piezocomposite rings with 77 μm epoxy width and 0.89 PZT volume fraction is presented, together with a PZT piezoceramic transducer of similar structure. With the guide of a finite-element modal analysis, the nature of most experimental resonance modes in the transducers is identified. The low lateral coupling of the composite rings effectively suppresses the non-axial and many other spurious resonances in the composite transducer, retaining only the axial-mode resonances. Due to the effect of epoxy damping, the composite transducer exhibits a 2.4-times reduction in Qm to a desired low value of 296. This transducer has good potential to be used in commercial wire bonders for enabling high-frequency wire-bonding technology.