Schilling Engineering builds energy-efficient cleanroom in Austria

The new semiconductor component facility is almost 400 sqm, half of which are up to ISO Class 6 for powder metallurgical processing of molybdenum and tungsten

Photo as seen on Schilling Engineering website

Austria-based Plansee Group has commissioned a semiconductor component production cleanroom from Schilling Engineering. Plansee specialises in the powder metallurgical processing of the high-tech metals molybdenum and tungsten.

The new cleanroom is almost 400 sqm, of which half is up to ISO Class 6, meeting the high safety standards of the semiconductor industry.

In Austria, where the company originated in 1921 as Metallwerk Plansee, lies its headquarters and the largest production site.

Hi-tech metalworking

If one thinks of a metalworking company it would initially be of production with shavings, dust and dirt. At Plansee, however, exactly the opposite is the case. The company focuses on refractory metals such as tungsten and molybdenum, which have special properties such as high resistance and good conductivity. The metals are first processed to high purity powder and then pressed, sintered and machined.

The semi-finished products and components are needed in the electronics industry, semiconductor manufacturing and medical technology. Absolute cleanliness in production is, therefore, the top priority.

Using the Schilling's cleanroom CleanCell4.0, components made of molybdenum and other materials are mounted, which are impaired in their function even by the smallest impurities. Over half of the 400 sqm production area therefore meets the strict purity requirements of ISO cleanroom class 6.

Energy-efficient recirculation

Using ceiling-integrated laminar floats equipped with ULPA 15 high-performance filters, clean air is introduced into the cleanroom. The particle-free air flows displace airborne particles downwards and are then removed from the cleanroom into the recirculating air duct. This air exchange process is performed up to 60 times per hour. Recirculation and return air circulation takes place within the cleanroom walls.

The already cooled and filtered air is thereby circulated, which contributes to very efficient operation of the cleanroom. In addition, the airflow within the walls ensures optimal use of space. Plansee has opted for a cleanroom system from Schilling Engineering.

Mario Kuisle, project engineer at Plansee explains the advantages of the system: "The recirculation system of the cleanroom system CleanCell4.0 convinced us from the beginning. We can save high energy costs here permanently. It was also important that the airflow inside the walls ensures optimal use of space. The cleanroom was adapted exactly to our circumstances."

The special conditions of the on-site site required in many ways a cleanroom that was tailored to customer needs. The project engineer recalls some of the challenges that came with the planning cleanroom company: "The on-site ceiling of the hall of Plansee is not statically suitable for suspension due to the expected snow loads. The cleanroom ceiling was then constructed using a self-supporting framework made of aluminium profiles. The ceiling is walkable and has been identified with stable walkways. A huge advantage of the design is that the cleanroom was constructed without columns and columns.

Modular construction

Another challenge was the desired height of the cleanroom, which was designed with four meters interior height higher than ordinary cleanrooms. The height required by the introduction of measuring machines, could be achieved with removable wall elements. The ceiling, which is equipped with 67 clean air units, has a modular design and can be flexibly redesigned. The modular system of the cleanroom CleanCell4.0 enables flexible planning of future utilisation.

Mario Kuisle explained: "The modular design of the cleanroom system helped us tremendously with our investment decision. We wanted to be able to convert the cleanroom quickly and flexibly to other production processes. At the moment we are producing for semiconductor manufacturing and have integrated the production machines in the cleanroom walls. Thanks to the modular wall and ceiling elements, we will be able to convert to changing occupancy concepts in the future."

Intelligent control

Dimmable LED strip lights are homogeneously integrated into the aluminium strips of the ceiling, which at 1000 lux achieve uniform lighting with little shadow and contribute to energy savings. Doors and material locks are also illuminated LED and visualise with different colours, whether a door can be opened or for pressure equalisation and active flushing must first remain closed. Intelligent control is provided by the connected control and monitoring system CR-Control, which controls and monitors individual filter units, production-relevant room data such as temperature and humidity and air-conditioning technology. The air conditioning is characterised by an extremely energy-efficient treatment of the air.

Kuisle said: “The cleanroom runs perfectly. The technology is very complex, but perfectly coordinated and well thought out. The energy optimisation of the cleanroom was very important to us. By using a heat pump, we can save long-term high additional costs. We also have the option to programme a night reduction. Very positive are the quiet filters and the good lighting, which facilitates the daily work in the cleanroom.”

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