Cleaning parts before they enter the cleanroom is an art in itself. The Frencken Group has chosen to master it. Last quarter, the company unveiled a cleaning line that will enable it to clean parts so they meet the stringent demands of ultra-high vacuum.
Time doesn’t stand still in the high-tech sector. Large OEMs are increasingly probing the boundaries of what’s technologically possible, with machine parts whose design is getting smaller and more complex by the day. Because contaminated parts can disrupt their clients’ processes, parts cleaning is also growing more complex, and cleanliness standards are constantly getting stricter.
Not many people realize it, but the cleaning of components before they may enter a cleanroom is a specialism in itself. ‘For a specific type of material that always comes in the same way, you can figure out a cleaning process,’ says Sjoerd Thomassen, a customer team leader at Frencken. ‘But you have to accommodate different types of materials, process fluids and component geometries. You also have different cleaning requirements you have to meet, and different suppliers each observe their own standards of cleanliness.’
Particularly in the semiconductor and analytic markets, says Thomassen, the trend in recent years has been toward increasingly strict cleanliness standards. ‘ASML is an accelerator there, of course, with its EUV platform, but you also see it with other clients in other technologies, such as Bruker, Thermo-Fisher and FEI.’ Because requirements continue to get stricter, cleaning is often contracted out to a specialized company. But there are risks with that approach, both in terms of logistics and in terms of quality.
To minimize these risks, Frencken has invested in its own advanced cleaning line, which ends right at the company’s own cleanrooms and cleans ‘dirty’ products to the ultimate level for high-tech applications: ultra-high vacuum. ‘Ultra-high vacuum is a term the market uses when something will be subject to high vacuum,’ Thomassen explains. ‘That increases the likelihood of outgassing. We’re now able to achieve the precision cleaning required for working at the highest level of vacuum.’
The line’s completion last quarter put Frencken in possession of the most advanced and ambitious cleaning installation in the region. To create it, the company looked not only at the machine itself, but at the entire cleaning process, using specifications it derived from client requirements.

Bolt hole
How exactly does the line clean components? First they go into a basket, which is submerged in a series of soap baths and then rinse baths (using de-ionized or reverse osmosis filtered water). There, they are subjected to ultrasonic frequencies to vibrate grime and debris loose. ‘We can also rotate the baskets,’ says Thomassen. ‘If you have a product with a chamber or a bolt hole, for example, you can imagine that liquid might pool there. By rotating the component, you also rinse those holes.’
And there are a few more advanced tricks. For example, the ultrasonic frequency of each bath can be adjusted, and Frencken makes its own DI and RO water. That turned out to be necessary to clean products to the highest level. What’s more, the company has hired a process engineer who is responsible for the cleaning line.
But Thomassen is convinced it’s worth it. ‘We’re so much more flexible; we maintain control of the process and we can advise our clients based on our own expertise. The project also included expanding our cleanroom and our logistics centre. We also decided to do laser welding and orbital welding in the cleanroom. That process is clean, so we don’t have to do additional cleaning afterward.’
Frencken now has an advanced cleaning and cleanroom environment that not only makes the company more efficient and flexible, but also puts it in full control of its products and processes – something for which demand will only grow in the future.
