Ultrasonic cleaning in clean rooms: 5 important aspects for optimal results

Ultrasonic cleaning is a proven method for thoroughly cleaning components and materials. Particularly in photonics, microelectronics and research, where maximum precision is required, the smallest contaminants can have fatal consequences. Careful planning and execution of cleaning is crucial to achieve optimal results. Here are five essential tips to help you do just that:

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1. Adapt devices to the clean room environment

Ultrasonic cleaners can themselves be a source of particles if they do not meet cleanroom requirements. Therefore, choose devices with smooth, anti-static surfaces that are easy to clean【1】. Place the device in an area with optimal airflow, such as under a laminar flow box, to prevent particle accumulation【2】.

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2. Select cleaning fluids specifically

Not every liquid is suitable for ultrasonic cleaning. Use solutions that evaporate without leaving any residue and pose no additional risk of contamination. Deionized water is ideal for microelectronics applications as it has no conductive or corrosive properties【3】. Special cleanroom cleaning agents can also remove stubborn residues without damaging sensitive materials【4】【5】.

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3. Control aerosols

During ultrasonic cleaning, fine particles or aerosols can be produced, which impair air purity. Make sure that there is a suitable suction unit【1】and, if possible, place the cleaning system in an area with laminar air flows【2】. Regular air quality measurements help to monitor the process and identify contamination risks at an early stage【5】.

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4. Handle the components correctly

Place the parts to be cleaned in the liquid so that they are completely submerged and do not lie on top of each other. This ensures consistent cleaning and protects the components from mechanical damage caused by sound waves【1】. Use vibration-resistant brackets so as not to interfere with cleaning and achieve optimal results【5】.

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5. Efficient post-processing and drying

After cleaning, drying is essential to avoid water stains or residues. Cleanroom-compliant drying methods such as nitrogen flushing or vacuum dryers are ideal to prevent new particle contamination【3】. Make sure that all surfaces are completely dry before the components are further processed【1】.

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Conclusion: Perfect cleaning for the highest demands

Cleanroom ultrasonic cleaning is a complex but essential technique to ensure precision and purity. By choosing the right equipment, fluids and processes, you ensure the quality of your components and minimize the risk of contamination. Whether cleaning optical lenses or sensitive semiconductors — a well-planned process ensures perfect results.

If you need assistance in planning and implementing your cleanroom processes, Nordair Systems is happy to help. With our expertise, we develop solutions that meet your requirements and are efficient and reliable at the same time.

Source citations

1. ISO 14644-4:2021, clean rooms and associated clean room areas — planning and execution.
2. ISO 14644-1:2015, clean rooms and associated clean room areas — Classification of air purity by particle concentration.
3. ISO 14644-5:2004, clean rooms and associated clean room areas — cleaning and operating practices.
4. Ljungqvist B., Reinmüller B. (2020), People as a Contamination Source in Pharmaceutical Cleanrooms.
5. Perry, J., Agui, J., & Vijayakumar, R. (2016). Removal of submicron and nanoparticle contaminants by HEPA-rated media filters and packed beds of granular materials. Journal of Aerosol Science.

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