Soldering & Surface Mount Technology

Purpose – To evaluate the role of imposed strain on whisker growth in matte tin, and to identify the appropriate deformation states and environments that will facilitate the development of a reliable, accelerated test methodology to provide results representative of whisker growth under long-term service conditions.

Design/methodology/approach – Whisker growth in matte tin coated strips and wires of copper subjected to various outer fibre strains was characterized at three different temperatures under different humidity conditions.

Findings – This study presents findings of the influence of imposed strain and temperature on whisker growth in a matte tin layers present on a copper substrate. A decrease in incubation time and accelerated growth of whiskers occur with critical imposed strain and specific environmental temperature.

Originality/value – Whisker growth in tin coatings is becoming a major reliability concern in modern microelectronics. Immersion coating that produces a matte tin layer is being used extensively in electronic applications. The findings of this study facilitate the development of accelerated tests which represent events that occur over long periods of time during service so that suitable mitigation strategies can be evaluated in a reasonable time period.