How to Garner the Most Accurate and Consistent Bids for your Cleanroom

OLYMPUS DIGITAL CAMERAWhen it comes to reviewing job bids for cleanrooms, comparing the proposals can be a lot of work. If you don’t have everyone on the same page as far as what you want, and if sketches aren’t consistent, it will be really tough to fairly evaluate all the bids. To ensure that you can make the best decision, here are several tips as to how navigate this process.

An accurate bid depends on a thorough specifications sheet. Your first step is to create one of these for all your bidding contractors to work from. It ensures that they know exactly what you need, and it helps you make an “apples to apples” comparison of their proposals. Here is what you need on this sheet:

  • Your room’s classification.
  • Temperature specs and tolerance.
  • Humidity specs and tolerance. Humidity control is the most expensive part of a bid, so if this is only necessary for operator comfort, leave it out. If humidity control is critical to the process, express that and include it on the document.
  • The amount of process exhaust in CFM.
  • Include the process heat load in kilowatts. This is dependent upon what is in the room, like process machines or ovens. Controlled Environments suggests, “If you are not sure about this item, list the connected electrical voltage and current draw (amps) to start with. This will ensure some A/C tonnage is dedicated to this specification” (“Point of View: An Apple To Apple Comparison on Cleanroom Proposals,” Kelly Barton.)
  • Identify the number of operators that will be in the room.
  • It will be helpful to also include a brief definition of the manufacturing process (or product) as well as a description of the host building. This may determine where HVAC equipment can be placed.


If your staff is unable to create this sheet, hire someone who can. The sheet need only be basic. Provide the spec sheet to the contractors, and ask them to separately itemize anything they feel is necessary but isn’t on the specifications sheet.

You also want to provide the contractors with the same sketch that includes the ceiling height and room sizes. Of course, if you have any other critical parameters, include those as well.

Expect to have an initial bid phase and a final bid phase as you move forward. Getting everyone on the same page will help both you and your potential contractors communicate clearly and in a timely manner. For the full article, go here.

Gerbig Engineering Company proudly manufactures Airecell cleanrooms. We also provide certification and validation services. For any questions about your cleanroom needs, contact us at 888-628-0056 or


What Materials Can Be Used in a Cleanroom?

SAGE Coater Buffer Steel with headerThe individual classes of cleanrooms will dictate many specifics regarding the types of materials allowed in a controlled environment. For example, required garments and acceptable garment materials vary by class.  The same is true for solvents. Then there are everyday items that are generally prohibited in any cleanroom. Some of these items are available in a cleanroom-approved form. It is imperative that these approved items are used and never substituted with everyday items. Here is a general breakdown of things you don’t want in your cleanroom and also which items can be found cleanroom-approved.

Prohibited Cleanroom Materials:

    • • Food and drink
    • • Gum
    • • Makeup
    • • Wood products
    • • Leather
    • • Bare aluminum
    • • Cardboard
    • • Regular writing utensils
    • • Regular paper or notebooks
    • • Books and bookbags
    • • Greases, oils, lubricants
    • • Silica gel
    • • Any unapproved tape or adhesive
    • • Plastic bags
    • • Bubble wrap
    • • Velcro
    • • Powders
    • • Aerosol
    • • Open cell foam materials
    • • Commercial vacuum cleaners (or other unapproved cleaning equipment)
    • • Unapproved plastic

As you can probably gather by reading the list, several of these items are available as cleanroom-approved materials. Many cleanroom suppliers offer cleanroom-safe objects that include:

    • • Paper and notebooks
    • • Pens and pencils
    • • Adhesives or tape
    • • Solvents
    • • Cleaning materials, including containers, mops, buckets, vacuum cleaners, wipes, detergents and more
    • • Plastic containers

Keeping Contaminate Levels Down

Protocol will vary for electronics, so make sure you know the rules of your cleanroom before bringing in laptops, cell phones, and any other similar equipment. Additionally, certain behavior will help keep contaminate levels down:

    • • Work in slow, calm movements
    • • Keep talking to a minimum
    • • Do not enter a cleanroom immediately after smoking
    • • Wash hands before and after you’ve been in a cleanroom
    • • Put clothes on and take them off in the correct order. For most environments, you’d follow the order cap, gown/full dress, shoes, and gloves. You would remove each in reverse order
    • • Ensure that your clothing fits properly before entering the cleanroom
    • • Use hairnets and beard covers
    • • Don’t bring unnecessary items into a cleanroom

Remember: particulate control is not only dependent on the materials used in the cleanroom; personnel create more particles than anything else. Using proper garments as well as appropriate hygiene and behavior will all significantly affect cleanroom integrity.

When in Doubt, Don’t Bring it in

As a general rule of thumb for materials, when in doubt, don’t bring it in. You never want to risk compromising the cleanliness of a controlled environment. It is helpful to keep a list of acceptable materials somewhere all personnel can easily access it. Encourage staff to work as a team and train them on the proper way to tell someone else if he or she is behaving inappropriately. Many mistakes can be avoided when everyone looks out for each other.


Gerbig Cleanrooms performs certification and validation of cleanrooms. We also build quality Airecell cleanrooms. For questions about equipment, processes, or construction, contact us at 888-628-0056 or

Electronics Manufacturing: Cleaning Options

assembly_facility.jpgElectronics manufacturers have a few things to consider when determining how to best clean electronics. These include the cleaning solvent, equipment, and whether to use a wet or dry process. Here is a short breakdown of these considerations.

Cleaning agents

The right cleaning agent depends on what you’re removing and what it’s stuck to. Doris Schulz of Controlled Environments describes in “Cleaning in Electronics Manufacturing” the kinds of cleaning agents used in this industry. “Cleaning agents currently used in electronics manufacturing include solvents, water-based media containing alkaline surfactants, and water-based tenside-free cleaning agents.”

She also explains that solvents contain modified alcohols, non-halogenated hydrocarbons, or hydrofluorethers (HFEs).

Monosolvent systems usually use an azeotrope or pure HFE to remove:

  • Particles
  • Halogen compounds
  • Dust
  • Light oils
  • Residue of easy clean solvent
  • Other slight impurities


Cosolvent systems combine an HFE with a low-volatility organic solvent. Bisolvent systems are similar but the solvent and rinsing agent are kept separate whereas they are mixed together in a cosolvent. These best remove:

  • Grease
  • Heavy oils
  • Adhesives
  • Waxes
  • NC-flux residues
  • Hot-melt glues
  • Other more stubborn impurities


Wet Cleaning Systems

When choosing your system, Shulz advises to answer the following questions: “What throughput must be handled? What space is available in which to set up the equipment? How can the cleaning process be integrated into the manufacturing chain?”

Think about these questions when you choose from the many available cleaning systems. The variety of systems exists because the variety of plants demands it. Systems range from spray cleaning to pressure flooding to ultrasound. Choose what makes the most sense in your space and within your technology.

What makes ultrasound technology a popular choice for cleaning is the varying frequencies that can be applied. This one method can be used for many applications. Even experts who restore fire-damaged electronics can use ultrasound to get equipment clean and working again. The lower the frequency, the more energy is released. Ask your equipment or cleaning agent supplier about the right frequency for your needs.


Dry Cleaning Systems

There are some alternatives to the wet systems, and they mainly include CO2 and plasma.

Compressed carbon dioxide – This works very well to access crevices, small holes, and the like. It is dry, residue-free, and environmentally-friendly. Shulz explains: “In electronics manufacturing this technology offers the ability to clean such items as complete PCBs and assemblies, removing flux residues and cleaning away oils and grease from metallic components such as contacts.”

CO2 Snow jet cleaning – These minute snow crystals have chemical, thermal, and mechanical properties. This dry process is non-poisonous and non-inflammable. Shulz says, “CO2 snow removes surface films and particulate contamination leaving no residue, and can also be used selectively on functional areas such as contact points.”

Plasma – The physical and chemical reaction of this procedure offers both a surface treatment for multiple components and electronic parts and also effective cleaning of organic impurities. Depending on your needs, you can either choose a low-pressure plasma or inline-capable atmospheric pressure plasma.

While no-clean fluxes and soldering plates have changed the electronics manufacturing industry, cleaning has not become obsolete. If these no-clean components are exposed to humidity or fluctuation temperatures, they gradually erode. Furthermore, many processes and components demand a high level of surface cleanliness. Compare your needs against the capabilities of the cleansing agents and systems to find the best fit for you.


Gerbig Engineering Company builds high-quality cleanrooms. We also perform certification and validation. For questions about your cleanroom needs, contact us at 888-628-0056 or

Certifying your Cleanroom

certification_1As anyone who does or will operate a cleanroom probably knows, that room and all of its pieces have to meet a specific set of class standards. Certification is a major part of compliance, and all cleanrooms need it done. What exactly does that mean, though?


Basically, cleanroom certification is a pass/fail test based on the standards set forth by The National Environmental Balancing Bureau (NEBB). The organization’s Procedural Standards for Certified Testing of Cleanrooms constitutes a “uniform and systematic set of criteria for the performance of cleanroom testing and certification.” A true cleanroom certification refers to the ISO 14644-1 classification test. Put most simply, its documents are concerned with airborne particle contamination within the cleanroom. Passing the test means that the airborne particles were within the set limit for the class.


NEBB’s manual contains the minimum requirements to follow for testing and certification, though. Cleanrooms not only have to remain compliant with their class standards, they also have to meet customer quality specifications. For this reason, the pass/fail criteria for each entity’s certification will be different. Certifiers will base test protocols on customer specifications.


Cleanroom Testing Categories

Cleanroom certification is ongoing. A certifier will play a role both during and after construction of the cleanroom to ensure it is compliant after it’s built. Routine certification is also necessary. There are three categories for cleanroom testing:

    • As Built – this is a newly constructed and unoccupied space
    • At Rest – this facility is already functional but unoccupied with processes shut down
    • Operational – just as it sounds, this test is performed with people, processes, and tools fully functioning


Primary Cleanroom Tests

Primary cleanroom tests will include:

    • ISO 14644-1 particle counts
    • Room pressure differentials
    • HEPA filter velocity/volume
    • Air changes per hour calculation
    • HEPA filter integrity test


Additional Cleanroom Tests

    • Temperature and humidity uniformity
    • Particle recovery
    • Airflow visualization smoke test
    • Light levels
    • Sound levels
    • Static electricity evaluation/dissipation testing
    • Laminarity


Cleanroom Environmental Monitoring

There is also environmental monitoring, which includes:

    • Airborne viable organisms
    • Surface viable organisms
    • Airborne particle counts
    • Room temperature and humidity
    • Room pressure


Experts recommend finding a qualified professional rather than try to accomplish it in-house. The equipment is expensive, and there is a lot of it. Additionally, individuals need to be qualified to use the equipment. It is not cost-effective to do certification yourself.

Cleanroom Testing: Frequency

Your certification schedule will depend on your cleanroom class. You may need monthly, annual, or biennial checks. No matter the case, it’s important to stay up to date to avoid costly problems later.


Gerbig Cleanrooms provides expert certification services for cleanrooms. For information on these services, visit this page. Feel free to contact us by phone: 888-628-0056 or email:

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