ISO Class 3, 4 cleanrooms slated to meet demands of telecommunications market
by John E. Pettit
When Anadigics Inc. (Warren, NJ) unveiled its new 6-inch analog gallium arsenide (GaAs) fab in mid-1999, the company did not expect to see the current growth in the wireless and broadband communications markets.
The exterior of Anadigics’s Warren, NJ, facility.
In response to the growing demand for product, Anadigics announced its plans earlier this year to expand its 6-inch 150,000-square-foot production facility to include an ISO Class 4 (Class 10) cleanroom and equipment installation within its existing InGaP heterojunction bipolar transistor and metal semiconductor field-effect transistor manufacturing facilities. The expanded facilities will approximately double current production capability.
When the cleanroom is complete, it will be 60 percent classified ISO Class 4 with the remaining 40 percent representing the service areai.e. gowning area. Though at first it will be ISO Class 4, due to improvements in the technologies installed, it could eventually be rated as ISO Class 3 (Class 1).
When Anadigics embarked on the expansion project, The Tefen Group, located in Israel, was brought in as a consultant for its expertise in facility layout design. Tefen's team provided a complete facility layout solution encompassing macro layout, micro layout and a detailed layout design.
Anadigics Inc. (Warren, NJ) built a 6-inch analog gallium arsenid fab in mid-1999, and less than a year later, the company began an expansion that will include an ISO Class 4 (Class 10) cleanroom.
During the macro layout phase, tools such as process flow charts, capacity models, transaction matrices and decision matrices are used together with the data collected by engineers to develop several macro layout alternatives.
The output of the macro layout is used as the starting point for the micro phase. This input is used together with cluster analysis and process grouping to create a micro layout design, which contains all the details required for an optimal production system.
With these tools, Anadigics had the ability to manipulate the layout before it was finalized, giving the company the opportunity to improve the process for optimal cycle time.
The project is a hybrid of a design build and “bid 'n' spec” where the architectural engineering firm is on site working with Tefen and the general contractor on a full-time basis. With this arrangement, the company is receiving all the benefits of a fully designed “bid 'n' spec” job with a thorough plan comprising engineering and drawings.
With plans for the project to be completed during the second half of this year, Anadigics has kept an aggressive schedule. In fact, equipment was selected based on whether a vendor could deliver by a specified date.
Equipment flexibility is also an important issue. The space was designed to facilitate equipment tool moves so if equipment changes over time, the walls and ceiling can be moved accordingly. The Plascore wall system meets this need. As technology evolves and new tools are brought in, walls can be moved to accommodate the equipment, providing Anadigics with the ability to react quickly to growth.
Cleanpak International is providing a “gel ceiling,” which seals ULPA filters to a ceiling grid system using a special gel. The floor system is from Maxcess Technologies. Also specified is a 1,000-ton York chiller, which will keep the air and equipment cool. The new fab will also include eight 60,000-ton CFM air handlers and a 40,000-ton make-up air unit for dehumidification.
To control airborne particles, Anadigics opted for pressurization, saying it is the best way to control contamination. Plans are to have pressure controlled separately in each space so that the gowning room will be set at a different pressure than the corridor offering better contamination control. With pressure set differently, particles will be kept from moving from the dirty to clean space.
Safety and challenges
The design team plans to make the cleanroom a showplace for safety. Anadigics is sparing no expense to insure that employees feel comfortable about their safety. When designing the project, safety was the first area to be considered with hazardous gas monitoring and fire protection being taken to the next level.
For fire protection, the pressurization of the rooms will enable a smoke condition to be isolated so it does not spread throughout the entire area. Additionally, Anadigics will be monitoring for other gases that are not required by code. These gases include Boron trichloride, hydrogen bromide, methane and ammonia.
One of the biggest challenges is determining how the new space can handle the loads. The structural engineers continually look over the designs to be sure that the floor can adequately support the new equipment.
The new cleanroom is designed into an area that was originally built in 1963. While designing for the loads, the construction team realized that an additional electrical substation was needed. A 15,000-volt feeder will be run across the new corporate offices, which were completed in May.
The $10-million expansion will provide Anadigics with the additional capacity to meet customer demand. As demand for the company's wireless and broadband radio frequency integrated circuit (RFIC) solutions continues to increase this cleanroom expansion to 20,000 square feet enables Anadigics to generate five times its current revenue.
John E. Pettit is facilities manager at Anadigics Inc. (Warren, NJ).