Semiconductor Manufacturing Dresden::

Semiconductor production: the shields are in a cleanroom according to ISO Class 3 installed: ISO Class 3: for example, max 35 particles in the size of 0.5µm (0.5 micro-meters) per m3 are accepted.

Clean room classes in accordance with ISO 14644-1

  Particle per m²
Class 0.1 µm 0.2 µm 0.3 µm 0.5 µm 1.0 µm 5.0 µm
ISO 1  10 2        
ISO 2 100  24 10 4    
ISO 3  1.000  237  102  35 8  
ISO 4  10.000  2.370  1.020  352  83  
ISO 5  100.000  23.700  10.200  3.530  832  29
ISO 6  1.000.000  237.000  102.000  35.200  8.320  293
ISO 7        352.000  83.200  2.930
ISO 8        3.520.000  832.000  29.300
ISO 9       35.200.000  8.320.000  293.000





IMG 3060

. SL370191
Mounting the shield
Measurement of the shielding effect
  Company logo

ETH Lausanne, Surface shielding laboratory ::


IMG 2988 . IMG 2989 . IMG 2995
The laboratory room during the shielding work:
floor, ceiling, walls are being shielded
Assembly of the wall shielding
Wall shield firmly screwed before welding the impact junction
IMG 3001   IMG 2989  
ETH Lausanne
Picture 4
Picture 5
 FEI TEM installation "Video"

SBB Main Station Zurich, Surface shielding ::

Space shielding to comply with the AGW
In the largest train station in Switzerland, the main station in Zurich, the transformer station 24 had to be moved locally because of the construction of the new diameter line. Directly above and below the transformer station are places of sensitive use "OMEN", namely the shops of the Shopville below the transformer station and the Kiosk systems above the transfer station. In accordance with the regulation of non-ionising radiation, NISV, the installation limit value, AGW, has to be adhered to. To do so, the entire transformer station opposite the OMEN has to be shielded upwards and downwards. The transformer station consists of three separate rooms, one room for the four transformers, one for the medium-voltage switchgear and one for the low voltage distribution. The rooms were passively shielded with Systron Power Shield® on all sides, floor, ceiling and walls. The shielded area is approximately 800m2.
NSV-Raum-letzte-Schweissnaht . NSV-Raum-mit-Rost . MS-Raum-mit-MS
The low voltage room during the shielding work: floor, ceiling, walls are shielded.
The low voltage room completely shielded. The framework for the distribution is already set.
  The medium voltage room completely shielded with integrated medium voltage system.

Binnig and Rohrer Nano Technology Center, "Low Field Room™"::

"Low Field Room™" for nano-tech laboratories 

Description and concept

In the Binnig and Rohner NanoTechnology Center, Rueschlikon, Zurich, so-called "Noise free" rooms, laboratories for extremely sensitive measurements and experiments, were implemented. These laboratories were also protected against the influence of low-frequency magnetic fields. The Specification: "Magnetic Fields rail 16.7 Hz and in-house 50 Hz fields (and harmonics) are to be limited to values of <5nT (internal specification for low-noise optimized laboratories, Noise Free Labs)". Named as the in-house main sources of interference were the transformer station with NS-distribution and MS-system, the air-conditioning control panel and cable channels. In addition, the DC-fields of the lift and the fields of the trucks driving in and out of the delivery had to be included in the concept.
The guaranteed compliance of the specified values has been assured with the  "Low Field Room™" concept of Systron EMV GmbH, which was specially developed for those laboratories, it is a combination of magnetic field shielding and compensation system. The shielding fulfills the function of a "basic" field reduction, the compensation limits the remaining fields to the required values. Special about this system is, the shield and the compensation system are coordinated so that there are no interactions between the systems.

Passive shielding and active compensation

Passive shielding: 

The soft annealed nickel-iron (so-called "Mu-metals") and aluminum consisting passive shield was installed on the floor, walls and ceiling in all laboratories. In addition to the laboratory space shields, the walls and ceiling of the in-house transformer station and climate control center were shielded in the same way. The passive shielding of the Laboratories reduces external noise fields on the one hand and on the other prevents fields from entering the neighboring laboratories. The passive shielding homogenized the fields, therefore a large-volume compensation is possible.

Active compensation:

After the fields are already greatly reduced with the passive space shields, the remaining fields are reduced to <5nT with the compensation (32dB). Via a sensor (placed as close as possible to the "Tools") the remaining fields are measured and compensated through six coil pairs by counter fields. The compensation system operates in the frequency range between 0.00 1Hz (DC) and 10kHz. Therefore, both DC- (elevator, trucks, doors) and AC-fields (path and power) are compensated.


IBM Binnig und Rohner Nanotechcenter, Neubau Grundriss IBM Noise Free Labs Noise Free Lab im Rohbau Magnetfeldmessung im Noise Free Lab
In Construction: Binnig and Rohner Nano Technology Center
The layout of the "Noise Free Labs"
"Noise Free Lab" shell construction, room height 6.4m
Review of the measured values during the shielding installation
Raum geschirmt mit Innenwand IBM Noise Free Labs Lüftungsdurchführungen IBM Noise Free Labs abgeschirmte Mediendurchführungen IBM Noise Free Lab abgeschirmt mit Powershield
"Noise Free Lab" preliminary construction Shielded ventilation openings Shielded media penetrations "Noise Free Lab" fully developed

Measurement Results

Shielding effect of passive shielding regarding near fields:
Magnetfeldmessung Spule
Magnetfeldmessung Noise Free Lab
Reduction factor passive shielding: 30-50
With this measurement, the shielding effect of the passive shielding, regarding sources of interference in the vicinity, has been reviewed. 50Hz magnetic fields were generated with a coil placed outside the laboratory and the values were measured within and in the same distance outside the laboratory. 

Measurement structure Measurement results

Shielding effect of passive shielding regarding fields with single conductor characteristics:
Situation Magnetfeldmessung Magnetfeldmessung Noise Free Lab
Reduction factor passive shielding: 20-30

With this measurement, the shielding effect of passive shielding, regarding sources of interference with single conductor characteristics (compensating currents) has been reviewed. 50Hz magnetic fields were generated with a single conductor placed outside the laboratory and the values were measured within and in the same distance outside the laboratory.
Measurement structure Measurement results  

Field reduction of the active compensation:
dc felder ohne kompensation dc felder mit kompensation
Reduction factor active compensation

With this measurement the effect of the active compensation has been reviewed. Used as source was the elevator, which can still have a disturbing effect at a distance of 15m. This is the reason why the goods lift is blocked during sensitive measurements. DC interference fields of vehicles are actively limited with the compensation system.
DC fields without compensatio
 DC fields with compensation