Release Time:2019-03-12  Hits:

Indexed by: Journal Article

Date of Publication: 2018-04-01

Journal: MICROELECTRONICS RELIABILITY

Included Journals: SCIE、EI

Volume: 83

Page Number: 198-205

ISSN: 0026-2714

Key Words: Electronic packaging; Zinc; Tin; Finite element method; SEM; Nemst-Planck equation

Abstract: In microelectronic circuit exposed to humid environment, the growth phenomenon of dendritic deposits due to the electrochemical migration (ECM) of metallic ions, generates a serious reliability issue. ECM of Sn and Zn ions in deionized water with Sn-9Zn electrodes, has been in-situ studied at gap potentials of 3 and 5 V. At 3 V, tin ions (with 15.61 wt%) dominate the composition of metallic dendrites whereas Zn ions (with 20.99 wt%) show greater presence in the experiment with 5 V. The Nemst-Planck transport equation has been solved using finite element method in order to describe the kinetics of ECM of Sn2+ and Zn2+ ions. The composition of resultant dendrites is governed by the competition between advection rate, transport time scale and anodic surface concentration of metallic species.