De‐mystifying materials selection for lead‐free soldering

Abstract

Purpose

The lead‐free soldering process has been confounding the PWB fabricators when they set out to select the right materials for lead‐free soldering. This paper discusses the compatibility of currently available laminate materials for lead‐free assembly.

Design/methodology/approach

This paper has been written to provide a review of material characteristics. Problem areas are highlighted and methods for choosing each type of material for compatibility with lead‐free soldering process are described.

Findings

When lead is banned and taken out of the traditional tin‐lead solder, there are other metal alternatives to alloy with tin such as silver, bismuth, copper, and zinc, etc. The melting point of these lead‐free alloys is higher than the conventional tin‐lead solder. Consequently, the reflow temperature of the lead‐free solder can now reach 240‐250°C. As the reflow temperature is elevated, it will pose a severe reliability challenge to the laminate materials. The compatibility of currently available commercial laminate materials for lead‐free assembly are discussed in this paper.

Originality/value

The value of this paper is that it provides information and solutions relating to the selection of the most appropriate materials for use in lead‐free soldering and assembly.

Citation

Chen, C., Chiang, J. and Lee, F.Y. (2006), "De‐mystifying materials selection for lead‐free soldering", Circuit World, Vol. 32 No. 2, pp. 18-22. https://doi.org/10.1108/03056120610642860