The statement “change is inevitable” is nowhere more applicable than in the rapid market cycles and con tinuous pro duct devel opment of the micro electron ics in dustry. Facilities in this field must be quickly adaptable, with minimum disruption or downtime to operations.
To fit the bill, a cleanroom must be constructed of components that allow for change.
 A technician installs a PortaFab wall system. |
Modular cleanroom walls are designed to be flexible because upgrading, size requirements, equipment needs, and degrees of cleanliness often change ra pidly. Wall system frameworks can accommodate expansion and modification, as well as the integration of new equipment and tools. Also required is quick change over of equipment to minimize downtime and contamination. Machinery is con stantly moved in and out of cleanrooms, and thus it is important that the walls separating bays from chases in any location be penetrated, creating bulkhead openings by using components to “box” the equipment.
Most semiconductor facilities experience change during and after cleanroom installation. Sometimes, much equipment arrives on the job site late in the project, or the layout may be altered based on a change in the process. In either case, batten wall systems provide flexibility and consistent appearance for in-field modifications. Panels can be modified without affecting performance or appearance because there are no special edge features. As a result, the batten can be moved and sealed again.
Product contamination and high yields are of great concern in any manufacturing facility. In semiconductor facilities, many processes are more vulnerable to the effects of outgassing and electrostatic discharge. Wall panels are constructed with aluminum surfaces on both sides of aluminum honeycomb cores. The nonparticulating and non-outgassing materials also provide a structurally sound panel that is lightweight (approximately 1 lb/ft2).
While other composites have been used within the industry (polyethylene cores and gypsum), all aluminum panels provide the best combination of benefits. The aluminum skins can be finished with a conductive epoxy finish providing a very low surface resistivity (105-108W), in accordance with EOS/ESD-S11.11-1993, and an electrostatic decay of <10 percent IN 0.5/sec, per Federal Standard 101B Method 4066. These epoxy finishes can also provide chemical resistance to various concentrations and time exposures.
Another benefit of all aluminum wall panel construction is code compliance. The panel has a smoke development and flame spread of <10, meeting requirements up to Class 1.
Scott A. Kouri has seven years of experience specializing in modular construction for cleanroom applications and is sales manager of the Cleanroom Division at Porta-Fab Corp., e-mail [email protected].