Bismuth sodium titanate based lead-free ultrasonic transducer for microelectronics wirebonding applications

Abstract Bismuth sodium titanate based lead-free piezoelectric ceramic 0.885(Bi 1/2 Na 1/2 )TiO 3 –0.05(Bi 1/2 K 1/2 )TiO 3 –0.015(Bi 1/2 Li 1/2 )TiO 3 –0.05BaTiO 3 (BNKLBT-1.5) rings (OD = 12.7mm, ID = 5.1 mm and 2.3 mm thick) were fabricated and characterized. Four ceramic rings were sandwiched between front and back metal plates to form a pre-stressed piezoelectric sandwich transducer and used as the driving element of an ultrasonic wirebonding transducer and the performance of the transducer was evaluated. The BNKLBT-1.5 transducer, when fitted with titanium front and back plates, was found to have axial vibration comparable to that of PZT transducer thus showing that BNKLBT-1.5 has the potential to be used in fabricating lead-free ultrasonic wirebonding transducers.