RIASSUNTO
ABSTRACT
The tendency of electronic devices, sensors, and integrated circuits aim at applications of ultrahigh frequency, miniaturization, multi-functionality and super integration. One critical issue in the modern microfabrication industry is caused by the uncontrollable Tin-whisker growth on wire bonding, layer bonding, and coating, which impose tremendous restrictions on the reliability of products. For applications specific to electronic devices for coastal, maritime, and subsea requests, the impacts from sea waves, thermal cycle, bio-corrosion, salinity, oxygen, and pressure will largely affect the growth of Tin-whiskers. This article summarizes the current research on Tin-whiskers: the mechanism of its growth and latest methods of attenuating whiskers' growth, which provide theoretical and experimental support for higher reliability and lower cost of maintenance of off-shore microelectronic devices.
INTRODUCTION
The integrated electronic devices with various highly compact sensors and actuators are always facing the reliability issue caused by the spontaneous growth of Tin-whiskers, which are on the surfaces of wire bonding, coating area, and substrates with multiple layers. For applications in the ocean (especially the deep sea and the underwater volcanoes), environments are getting harsher due to high salinity, extremely high pressure, large thermal variation, bio-corrosion, moisture, and oxidation, which make the growth of whiskers more unpredictable. Thriving whiskers might cause short circuits between wires, trenches, and layers of micro-fabricated structures. Once the off-shore vehicles, with advanced electronic devices, dive into such a complex environment, the durability and its maintenance will be quite a challenge due to the whisker induced failures.
A large number of electronic packages comprise non-lead and disposable solders that breed the tin-based whiskers. Researchers have worked on the Tin-whiskers for years, nevertheless, the mechanisms of the germinating and breeding are still indeterminate. The prerequisites to the application of whiskers by evaluating, utilizing, or suppressing, not only on the micro-fabrication industry, are valuable for all the coming proposals.