Semiconductor manufacturing factories (fabs) incorporate a system of raised false floors to accommodate complex facilities requirements (plumbing, electrical cables, gas piping, etc.) and to maintain strict cleanliness standards. Such floors present a challenge to the installation
of extremely vibration-sensitive production, inspection, and metrology equipment. The raised floors cannot provide the necessary quiet vibration environment for such tools.
TMC’s Quiet Island® is an innovative solution that replaces a section of the raised floor area with a “Quiet Island” anchored to the sub-floor below. The Quiet Island consists of a special platform combined with a dedicated support structure, the nature of which depends upon the application.
The platform is a TMC designed and manufactured 4 inch (100 mm) thick lamination of steel plates sandwiched around a lightweight, incompressible, damped core material. The layering effect of rigid steel plates and core, epoxy bonded into a seamless, stainless steel pan provides an extremely high level of stiffness and structural damping. The large cross-section and steel content yield a very high level of overall rigidity. The top and sides are a continuous, one-piece, stainless steel shell to preserve cleanliness, appearance and integrity.
Depending on the specific application requirements, the platform supports are either a rigid, non-resonant support stand or a STACIS® 2100 Active Vibration Cancellation System. If the sub-floor meets the vibration criteria of the tool in question by a reasonable margin, simply supporting the tool with a support that does not amplify vibration is sufficient. To achieve this, TMC has designed a family of ultra-rigid support stands for a range of floor heights and sub-floor access hole requirements. Typically tripods, quad-stands or square cross-section stands, these attach directly to the sub-floor and platform.
However, if the sub-floor does not meet the tool vibration criteria, a “point-of-use” vibration isolation system must be employed. STACIS 2100 is the ideal choice. STACIS 2100 is compatible with all tool internal vibration isolation systems (ask for our “stacking active on active white paper”). In addition, it provides the most vibration isolation across the widest frequency range commercially available. And, the “hard-mount” design is extremely stiff so that there is no stability concern for tall, top-heavy tools.
The rigid stands and STACIS 2100 supports are interchangeable and field upgradable. Together, they provide the complete solution for supporting sensitive tools in a fab raised-floor environment.
Other Quiet Island Configurations
The many types of raised floors and installation challenges has led TMC to develop a number of innovative and unusual solutions. Among these are TMC’s patented Rigid Damped Tripod. If you have an unusual raised-floor challenge, chances are we already have a proven solution. Please contact one of our Application Engineers to learn more.