Analysis of lead-free piezoceramic based power ultrasonic transducers for wire bonding

Mathieson, A. and DeAngelis, D. A. (2016) Analysis of lead-free piezoceramic based power ultrasonic transducers for wire bonding. IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, 63(1), pp. 156-164. (doi: 10.1109/TUFFC.2015.2496216) (PMID:26584490)

Abstract

Since the 1950s, lead zirconium-titanate (PZT) has been the dominant transduction material utilized in power ultrasonics, while lead-free piezoceramics have been largely neglected due to their relatively poor piezoelectric and electromechanical properties. However, the implementation of environmental directives that regulate and control the use of hazardous materials, such as lead, triggered a search for new high performance lead-free piezoceramics. Recent advances have led to lead-free piezoceramics exhibiting properties similar to PZT, but despite this, reports utilizing these novel piezoceramics in practice are limited. This research employs a modified variant of bismuth sodium titanate (BNT) in a power ultrasonic transducer used for metal welding during the manufacture of semiconductors. The important factors for transducer reliability and performance are investigated, such as piezoceramic aging and stack preload level. It is reported that BNT based transducers exhibit good stability, and can withstand a stack preload level of 90 MPa without depoling. Although the BNT based transducers exhibited larger dissipative losses (tan δ) compared to identical PZT8 based transducers, the tool displacement gain was larger under constant current conditions. Semiconductor wire bonds which satisfied the commercial quality control requirements were also formed by this BNT based transducer.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Mathieson, Dr Andrew
• Authors: Mathieson, A., and DeAngelis, D. A.
• College/School: College of Science and Engineering > School of Engineering > Systems Power and Energy
• Journal Name: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
• Journal Abbr.: IEEE Trans Ultrason Ferroelectr Freq Control
• Publisher: IEEE
• ISSN: 0885-3010
• ISSN (Online): 1525-8955
• Copyright Holders: Copyright © 2015 Institute of Electrical and Electronics Engineers
• First Published: First published in IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control 2015
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher