Welcome to the Cleanroom
The main purpose of a cleanroom is to provide a workspace free from contaminants. Temperature, humidity, pressure and other conditions must be monitored and tightly controlled. The air needs to be filtered to capture airborne contamination and cleaned before being recirculated—and complete recirculation may need to occur more than five times per minute.
ISO Cleanroom Classification
In ISO 14644, the International Organization for Standardization (ISO) classifies levels of cleanroom. The top three considerations are:
- The amount of particulate matter present in a cubic meter of air.
- How large the particulates can be, in microns.
- The number of times the air must be changed per hour.
ISO Class 8, 7, and 6
These relatively light standards require approximately five times cleaner air than the average office environment. These standards can be achieved with high-efficiency particulate air filters (e.g., HEPA filters) in conjunction with cleanroom-safe apparel, tools, and cleaning products. This level of cleanroom is typically suitable for semiconductor manufacturing and solar panel production at the wafer level.
ISO Class 5, 4, and 3
These cleanroom categories introduce restrictions on smaller particles from 0.1 to 0.3 microns, with Class 3 requiring fewer than eight 1-micron particulates per cubic meter. This requires tighter ultra-low particulate air filtration (ULPA filters) and stricter compliance from all cleanroom workers. These environments are required for more sensitive applications, such as pharmaceutical production.
ISO Class 2
There’s clean, and there’s pristine. In an ISO Class 2 cleanroom, the acceptable number of half-micron sized particles per cubic foot of air is four. No particles larger than one micron are permitted. The air in these cleanrooms should be changed between 500-750 times per hour with total ceiling coverage.
ISO Class 1
A Class 1 cleanroom is immaculate. This is where you work with nanotechnology. 0.2 microns is the largest allowable particle per cubic meter, and you only get two of those before you’re kicked back down to Class 2—you can expect the same if more than ten 0.1-micron particles are detected.
Regardless of cleanroom classification, particulates are the enemy—and the best way to filter particulates from the air is to avoid bringing them into the cleanroom in the first place.
Cleanroom Personal Protection Equipment and Apparel
Personal protection equipment (PPE) and apparel make the biggest impact cleanrooms because personnel are the biggest risk factor for contamination. To prevent people from spreading contaminants, cleanroom apparel must be designed to avoid collecting any dust, shedding lint, or absorbing moisture as the wearer moves through the room. In addition to coveralls, gowns or coats, most cleanrooms require a combination of gloves, masks, shoe covers, fingercots, as well as hair and beard covers.
Cleanroom Tools & Accessories
Cleanroom Paper and Pens
If you love the aroma of libraries and bookstores, then you can smell the particulates that are involved with conventional paper products. Cleanroom paper resists linting and is ESD-safe to prevent attracting dust and other particles from being attracted to it via static charge. Cleanroom pens use a special low-sodium ink to avoid introducing new contaminants.
Cleanroom Swabs, Wipes and Brushes
If conventional writing paper is a non-starter in cleanrooms, you can imagine the problem with swabs, wipes, and brushes. Special considerations for ESD-safety help avoid attracting particles via static. The textiles of the wipes, the foam of the swabs, and the bristles of the brushes must be low-linting—and none of these can have a particularly abrasive texture.
Cleanroom Adhesive Mats
Using a roller, adhesive mats are applied to entry points and high-traffic areas in the cleanroom to trap particulates from shoes, shoe covers, wheels, etc. Once saturated, adhesive mats and films can be removed and disposed without spreading particulates. Think of them as welcome mats.
Techni-Pro Cleanroom Solutions
Techni-Pro is TestEquity’s private-label brand of electronic production supplies. If the toughest part of your work is keeping contamination out of your cleanroom, Techni-Pro offers solutions that WORK and are rated for cleanrooms up to ISO Class 5.
