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.
|Particle per m²|
|Class||0.1 µm||0.2 µm||0.3 µm||0.5 µm||1.0 µm||5.0 µm|
SBB Main Station Zurich, Surface shielding ::
Binnig and Rohrer Nano Technology Center, "Low Field Room™"::
"Low Field Room™" for nano-tech laboratories
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.
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.
|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
|"Noise Free Lab" preliminary construction||Shielded ventilation openings||Shielded media penetrations||"Noise Free Lab" fully developed|
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:
Field reduction of the active compensation: