2026-08-24 Original Article
In PECVD and CVD equipment, creating thin films requires precise mechanical motion inside a vacuum chamber. A hollow axle magnetic fluid feedthrough provides one method for this. It is a type of magnetic fluid rotary feedthrough for vacuum applications. The core mechanism uses ferrofluid as the sealing element, forming a dynamic, hermetic seal around a rotating shaft. This system transmits rotary motion into the vacuum chamber without breaking the seal integrity.
The basic concept for these seals was pioneered in the 1970s. Engineers created a liquid o-ring around a rotating shaft using ferrofluid, patenting the first commercial versions. For over forty years, design and manufacturing teams have refined this technology. Feedthrough parameters that can be modified include the mounting configuration, the specific ferrofluid used, the bearing type and position, and the shaft size. This allows for tailored solutions to meet specific system requirements.
PECVD and CVD systems represent a primary application area for these feedthroughs. The industry continues to push the boundaries of sealing technology to meet evolving demands. In ultra-high vacuum (UHV) environments, some systems use advanced magnetic coupling technology instead of fluids. However, for many standard and high-vacuum CVD applications, magnetic fluid feedthroughs remain a common choice. Their hollow axle design is particularly useful for passing utilities like electrical wires or cooling lines through the center of the rotating shaft.
The selection between a magnetic fluid feedthrough and a magnetically coupled drive often depends on the specific vacuum level and torque requirements. Magnetic fluid seals offer a proven, direct-drive solution. They have been engineered for decades, with teams often possessing at least a decade of first-hand professional experience in their production and application. When a standard product does not fit, a custom solution is typically available through direct consultation with a specialist.