SuSi special solution without "forbidden" substances

(Photograph: Reinhold Schuster)

(Photography: Reinhold Schuster)

(Photograph: Reinhold Schuster)

(Photography: Reinhold Schuster)

(Photograph: Reinhold Schuster)

(Photo: Reinhold Schuster)

(Photograph: Reinhold Schuster)

(Photograph: Reinhold Schuster)

(Photograph: Reinhold Schuster)

(Photography: Reinhold Schuster)

(Photograph: Reinhold Schuster)

(Photograph: Reinhold Schuster)

(Photography: Reinhold Schuster)

(Photography: Reinhold Schuster)

For a long-standing customer and supplier, SPETEC has optimized its proven Laminar Flow Box to the point that it is now completely silicone-free and gas-optimized. Twelve of these whisper-quiet devices are now located at GEWO Feinmechanik GmbH in Wörth, Bavaria, ensuring cleanroom quality of ISO classes 5 and 7.

"Sometimes, working with a good and long-standing customer is similar to a long marriage: you know each other's weaknesses but focus more on strengths and support each other in becoming better," says Spetec Managing Director and Sales Manager Christian Grüner. His gaze drifts over one of the twelve Laminar Flow Boxes installed at GEWO in the "SuSi" version, which stands for "SuperSilent."

Indeed, the experts from both companies have worked together in a mutual give-and-take to develop and realize the optimum solution. Previously, GEWO Feinmechanik GmbH decided to ensure the required ISO classes 5 and 7 within their 650 sqm cleanroom in the newly built Werk 2 using a zone concept similar to cleanroom workbenches.

The award-winning family-owned company, with 281 employees today, has developed extensive specialized expertise since its founding in 1981 in the
area of turning and milling parts for assembly groups in the semiconductor industry. Today, GEWO undertakes complex high-tech projects for clients such as Zeiss, Siemens, Agfa, Infineon, or MAN. These projects are managed from order intake through fully automated planning, CAD simulation of defect-free manufacturing of the workpiece, production, and assembly of even the most complex modules — if necessary under cleanroom conditions — to packaging and delivery of the finished products. All under one roof.

Constructive collaboration yields optimal results

When choosing the cleanroom workbenches to install, the decision was made in favor of the SPETEC Laminar Flow Box in the SuSi version, not only because of the long-standing business relationship with the regional supplier. The GEWO managers were also convinced by the flexibility, functionality, and overall design of this SPETEC product compared to similar systems.

However, before the partnership between the two companies delivered full success, some smaller hurdles had to be overcome. Initially, the measured test values were below the admittedly high target for residual gas analysis, which involved testing the finished parts and assemblies for cleanliness over five days.

The minimal outgassing identified during troubleshooting originated from the silicone and acrylic glass used at that time in the Laminar Flow Box. Through close cooperation and constructive dialogue, these minor weaknesses were eliminated. Today, Spetec offers this developed custom solution to other interested customers, establishing a special market position.

In detail, the special modules in the GEWO cleanroom consist of twelve Laminar Flow Boxes "SuSi," which are whisper-quiet and vibration-free, measuring 200 cm x 70 cm. All modules are equipped identically up to table height, allowing them to be exchanged or reconfigured quickly and easily as needed for different projects. This also proves to be a smart move in terms of maintenance and repair, as when one device fails, others are available for immediate replacement, and only one set of spare parts needs to be kept in stock for quick response. All modules are also fitted with safety glass. Although this material is significantly heavier than the standard acrylic glass used, it does not outgas, is resistant to cleaning and disinfectant agents, and is less prone to scratching.

A cleanroom for a variety of applications

And for what applications are all these specially equipped and whisper-quiet Laminar Flow Boxes actually used by the six employees in the large cleanroom at GEWO? For many different purposes. For example, GEWO assembles components for lithography systems for Zeiss, which print wafers onto circuit boards. These require so-called actuators that reduce the wafer pattern via small parabolic mirrors so strongly that the desired conductor track structures of around 2 nanometers (that’s 200 millionths of a millimeter) are created. These parts are later operated in ultra-high vacuum, where even tiny surface contaminations or minimal outgassing could cause failures.

In another flow box, where a pure air jet from below carries away all particles upward into the filter, ensuring ISO class 5 cleanroom quality, electron beam microscopes are assembled. Even the tiniest contaminations would be intolerable here. In yet another area, chromatographs are assembled in a flow box, which are used for highly precise liquid analysis and contamination detection.

Nearby, a worker manually assembles certain adhesive modules, supported by special fixtures. Naturally, all materials used there, such as films, adhesives, or labels, meet the highest standards for outgassing. Each component has its own serial number, recorded in the inventory management system along with all tracking data. This way, even the smallest contamination can be detected and traced during quality control — which, incidentally, is also performed directly in the cleanroom.

Mobile workbench with a personal touch

For Andreas Megele, the department head responsible for cleanroom topics at GEWO, the outstanding advantage of the installed SPETEC Laminar Flow Boxes — aside from their custom features — is their flexibility. "As soon as requirements change or we start a new project, we can move the flow box to another location with just a few quick steps. No modifications, no problems, no time loss. This cleanroom workbench is really very mobile," says Megele enthusiastically. Not least, this is a economically relevant factor for a company like GEWO, where new projects and requirements constantly emerge.

Finally, a charming Bavarian detail: although each Laminar Flow Box has the name SuSi printed in large letters at the top, the GEWO employees had the idea to give each of the twelve flow boxes their own female, naturally Bavarian first name. Now, besides SuSi, there is also Sissi, Silvi, Babsi, and so on. This brought a touch of human warmth into the particle-free and always cool 25-degree cleanroom.