Comparative Study of Metal Films and Their Affinity for Metal Whisker Growth

• Published in: IEEE transactions on components, packaging, and manufacturing technology (2011) Vol. 2; no. 5; pp. 739 - 747
• Main Authors: Fortier, A., Pecht, M. G.
• Format: Journal Article
• Language: English
• Published: Piscataway, NJ IEEE 01.05.2012; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Affinity; Applied sciences; Cadmium; Copper; Cross-disciplinary physics: materials science; rheology; Electrodeposition; Electrodeposition, electroplating; Electron microscopes; Electronics; Exact sciences and technology; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Ion beams; Materials science; Metal films; metal whiskers; Methods of deposition of films and coatings; film growth and epitaxy; Microelectronic fabrication (materials and surfaces technology); Microstructure; morphology; Physics; Scanning electron microscopy; Scanning probe microscopes, components and techniques; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Spectrometers; Steel; Substrates; thin films; Tin; tin whiskers; Zinc; zinc whiskers; Cadmium; Scanning electron microscopy; morphology; High density; Temperature effect; High temperature; Focused ion beam technology; tin whiskers; Whisker; Zinc; Thin film; thin films; Metallic thin films; Microelectronic fabrication; Humidity; metal whiskers; Electrodeposition; Reliability; Microstructure; zinc whiskers; Comparative study; Room temperature
• ISSN: 2156-3950; 2156-3985
• DOI: 10.1109/TCPMT.2012.2186812

The problem of tin (Sn) whiskers has been a significant reliability issue in electronics for the past several decades. Despite the large amount of research conducted on this issue, the growth of whiskers remains a challenge for the research community. A comparative study of different metal whiskers could provide a deeper insight toward the development of more permanent mitigation strategies for Sn whisker growth. In this paper, the surface and microstructural evolution of various film/substrate combinations of 10-μm thick zinc (Zn) and Sn metal films and their affinity for whisker growth were observed under two environmental conditions-ambient temperature and elevated temperature of 55 ° C and 85% humidity. The films were analyzed using a scanning electron microscope, focused ion beam, and electron dispersive spectroscope. In addition, several decades-aged samples with Zn, Sn, and cadmium films with a high density population of whiskers were observed for comparison.