With Dark Inspection to Perfection: Diamond SA Sets New Standards in Cleanroom Manufacturing

The 15-meter-long ISO 6 cleanroom can be completely darkened.

The UV examination room is entered via a black lacquered sliding door.

With two additional cleanroom facilities of ISO 6 class, Diamond SA has expanded its cleanroom area in Losone to 600 square meters. The Swiss high-tech company continuously invests in state-of-the-art manufacturing processes and sets new standards in the production of optical fibers.

Optical fibers, commonly known as glass fiber cables, are the backbone of modern data transmission technology and require the highest precision in manufacturing and testing. Diamond SA conducts part of its production in cleanrooms and has now commissioned two new cleanroom facilities.

A special feature of the new cleanrooms is dark inspection, which allows residual contamination on components to be detected using UV light, invisible under normal lighting. This inspection is crucial to ensure compliance with strict cleaning requirements.

Customized cleanroom solution with darkroom

The customized cleanroom solution from Schilling Engineering integrates a separate 15-meter-long UV area into the cleanroom facility. The innovative black coating of the room, including the matte blue floor, minimizes reflections and creates ideal conditions for UV-assisted dark testing. The composite panels used have the same coating thickness as the usual white panels, ensuring the same chemical resistance and cleanability.

Access to the new cleanrooms is via a opaque, black-painted rotary or sliding door, which is not only functional but also aesthetically pleasing. To minimize light entry into the darkroom, a special air handling system for climate control in the ceiling plenum and a particular over-ventilation system were planned. Instead of the usual direct installation of over-ventilation grilles into the wall, they are arranged offset so that air is drawn in from below and expelled above.

Complete darkening for effective UV light testing

Thanks to the ability to completely darken the room and eliminate light gaps, UV light testing can be carried out very effectively using flashlights or fixed-installed lamps. Residual particles fluoresce under UV light and can be detected more quickly and accurately due to the strong contrast of the black walls and table surfaces.

The darkroom contains two light sensors that can turn off the ceiling lighting at the workstation. During testing, this is signaled outside the room by a traffic light, so the inspection is not interrupted. The cleanroom area with the darkroom thus enables not only effective cleaning and testing of products but can also be used as a regular cleanroom area.

Gas- and outgas-free sealing compounds

Special requirements also applied to the sealing materials used in the cleanroom facilities. Sealants can release outgases that could damage highly precise products. For the Losone project, the cleanroom company was therefore provided with specially outgas-free sealing compounds to choose from. The new materials initially posed challenges for the service technicians from Schilling Engineering, as they were more difficult to process than standard sealants, but with growing experience, they could be used effectively.

With the successfully commissioned state-of-the-art facility, Diamond SA demonstrates impressively how specialized environments can elevate product quality to a new level. The customized cleanroom solutions are an important component of the technological advancement of their customers.