Whisker formation on matte Sn influencing of high humidity

The purpose of this study was to identify the main causes for whisker growth and to establish its mechanism, while at the same time identifying test conditions that can be used for an industry wide acceptance test for whisker formation, since this test has never been established. In order to understand the influence of humidity and corrosion on whisker growth the E4 (Freescale Semiconductor, Infineon, STMicroelectronics and Philips) started an extensive design of experiments (DoE). Parameters in this DoE include: plating, solderpaste, flux, substrate material, preconditioning and condensation. This paper presents the outcome of this DoE and furthermore give an update on the previously reported and ongoing experiments to discover the main factors influencing whisker growth.