Cleanrooms, by definition, must be completely clean. This is achieved using different supplies. Which supplies are needed and how they should be used varies as well. For instance, the products needed to clean a semiconductor cleanroom are different to those used in static cleanrooms. That said, all cleanrooms required acetone, wiping alcohol, and disinfectants. Shoe cleaners, tacky rollers, and tacky mats are generally also required. Then, there are the equipment cleaning supplies, such as the vacuum cleaner, the steam cleaner, and the sterilizer or autoclave. In a semiconductor cleanroom, almost all of these supplies are used.
Why Do Semiconductor Cleanroom Settings Need so Many Cleaning Supplies?
These supplies are necessary because of the very nature of the cleanroom. Complex pieces of technology are used here, and they must be understood. The first true cleanroom was developed at Sandia National Laboratories by Willis Whitfield in 1960. He focused specifically on having a constant filtered airflow. This ensures that the air was always clean. His invention is now known as the HEPA (High Efficiency Particulate Air) filter and continues to be integral in the manufacturing of semiconductors, which is done in cleanrooms. While the original design has been improved on, it is still virtually the same.
Another development has been that of classifying cleanrooms so that it is easy to see whether a facility is fit for purpose. The classification demonstrates how many particles can enter a specific space. Consider that air in the room around you has some 1,000,000,000 particles of at least 0.1 microns per cubic meter. In an ISO 1 cleanroom, there are just 10 such particles.
The cleaning supplies, meanwhile, are developed to perform at the ISO classification requirement. Hence, they must not only not generate new particles, they must also remove any that are in. The materials to achieve this can be either synthetic or organic, depending on their purpose. Common materials used include molded plastics, microfibers, polyester blends, nylon, cotton, and so on. Molded plastics and microfibers are classed as best for cleaning.
Cleanroom cleaning products must also be highly absorbent. They have to be able to clean the equipment, remove contaminants, and clean up spills. Towels, mops, wipes, and sponges all have to have the right absorbency. Cotton and paper are the least absorbent, followed by polyester blends, polyester, and nylon. The most absorbent are microfibers, which can hold as much as 600% of water by weight.
The specification of the cleaning supplies used in cleanrooms is very important. Determining which specifications are needed, however, is down to the environment that they have to clean. You must understand the different classifications of cleanrooms, therefore, and how to tell which products are able to meet those standards. Keeping a cleanroom completely sanitary, clean, and hygienic is vital. If it wasn’t, then the work in those rooms could just be completed in any other location. Unsurprisingly, this means specialized cleaning products are required, but also that those products are stored properly so that they do not attract other particles while being transported into and out of the cleanroom.
Daryl Green