For
the Proper function of equipment in critical environments, it
is absolutely necessary for there to be a clean, contaminate free
environment. Today, down-time has never been more costly and now more
than ever it is imperative to avoid unnecessary replacement of sensitive
equipment that has been damaged by contamination. These factors among others mandate that
contaminates be
eliminated. One
contaminate that has been gaining recognition worldwide is the development and accumulation of zinc crystals (also known
as "Zinc Needles" or "Zinc Whiskers") in clean rooms and
data centers with access flooring. The
formation of Zinc Whiskers (referred to as ZW in the rest of this article) on
surfaces with a galvanic zinc-electroplated passivation coating has long been
recognized as an issue within the electronics industry. Especially
concerning is the damage that these particles can cause to not only equipment
but also to personnel that have been exposed to them over a long period of time. Although there have not been enough
scientific studies to say conclusively what the health dangers of exposure to
ZW are, considering the hazards that other similar materials pose, such as
fiberglass needles or asbestos, it is clear why this should be a concern to
facilities managers.
Because zinc is an excellent conductor of electricity, when ZW come into contact with circuit boards or other electronics, the whiskers can cause short circuits and equipment failure. When power supply failures and issues are being experienced, facilities managers may have difficulty diagnosing that the problem is linked to ZW because the crystals may disintegrate when electricity passes through them. If operators are unaware that this might occur, they may not even suspect ZW as a possible cause.
In mission critical environments, most of the access floor tiles have been produced with a bottom "pan" that is formed from sheet metal coated with a zinc-galvanized coating. This zinc-galvanized coating is designed to act as first defense layer, and is actually designed to slowly corrode. This is done to protect the iron or steel below the zinc-galvanized coating and maintain the structural integrity of the metal tile. Many other building components in critical environments are also at times made using zinc galvanization coating, such as piping, different types of fasteners, and even sheet rock corner bead. Zinc galvanized metal surface coating is what allows ZW to develop, and any moisture that comes into contact with this coating will accelerate the process of corrosion. More and more access floor system manufacturers have begun to produce their systems using metallurgic technologies that inhibit the development of problematic ZW.
ZW can easily be dislodged from the surface where they developed, even routine activity can cause them to become airborne. Inherent to the design of critical environments is the re-circulation of the same air, thus ensuring a wide distribution of ZW when they are present in the environment. For many facilities ZW formation is going to happen because the access tiles and other building materials in facilities were made with metal components galvanized using a process that utilized pure zinc technology.
Paragon International offers complete sample analysis and on-site survey assistance. Our goal is to assist you with all on site issues that are encountered in your organization's critical environment.
