Proceeding of IMAPS International Conference on High Temperature Electronics (HITECH 2006), pp. 384-389, May 2006

Lead-Free Assemblies in High Temperature Applications

A. Choubey, D. Menschow, S. Ganesan, and M. Pecht
University of Maryland
College Park, MD 20742


Most electronics companies are transferring or have transferred to Pb-free electronics, both to comply with government legislations and to increase market share through product differentiation. Considering that Pb-based electronics have been in use for over 40 years, the adoption of Pb-free technology represents a dramatic change. Pb-free electronics are expected to be deployed in many products, including oil well applications, which require high reliability in high-temperature environments.

This study involves the design, manufacture, test, and analysis of printed circuit board (PCB) assemblies to obtain critical information related to the long-term exposure of Pb-free assemblies to high temperatures. Several components, including plastic ball grid arrays (PBGA) (Sn3Ag0.5Cu balls), quad flat packs (QFP) (Sn, Sn-Cu, Sn-Bi lead finish), and surface-mount resistors with Sn termination, were mounted on polyimide PCBs fabricated with various pad finishes (immersion-Sn (ImSn), immersion-Ag (ImAg), electroless nickel over immersion-gold (ENIG), and a patented fused Sn over Ni finish (SnNi)). The results from this study include both the extent of intermetallic growth in the solder joints, as a function of commercially available PCB pad finishes and component finishes, and the solder joint strength data for QFPs as a function of aging conditions and finishes.

Complete article is available to CALCE Consortium Members.


[Home Page] [Articles Page]
Copyright © 2006 by CALCE and the University of Maryland, All Rights Reserved