Enclosure for Fraunhofer/PGL Nanoruler
Fraunhofer USA’s Center for Manufacturing Innovation in Boston, MA approached Intelligent Enclosures (iE) to create a temperature controlled enclosure for a new laser interferometer device it developed with Plymouth Grating Labs of Plymouth, MA. Fraunhofer was commercializing a technology for PGL, developed at MIT, named the Nanoruler. The Nanoruler can pattern 5000 parallel lines in a single pass only 1nm wide, and exceeds a precision of 1nm across a 300mm substrate. PGL wanted a larger scale device that would allow it to create large gratings for laser based research with substrate sizes of 1000mm x 500mm x 100mm. To accommodate the large grating substrates the Scanning-Beam Interference Lithography (SBIL) device required a larger enclosure with precise control of the environment to prevent inaccuracies in the nanometer tolerance of the gratings. iE first used CFD analysis to develop an airflow design that would provide the maximum temperature stability at the process zone, then iE designed an Enclosure with an enclosed space of 12 ft. long 10 ft. wide by 7.5ft high. The enclosure has an onboard Programmable Automation Control (PAC) to manage temperature, humidity, and air volume, and measures 18.7 ft. long, 10.5 ft. wide and 9.3 ft. high. Even with the size of the space enclosed, iE is able to provide temperature stability of ±5 mK (±0.005ºC). Within the panels and duct work of the Enclosure iE provided acoustic attenuation moderating the ambient noise level to protect the process. The Enclosure was first tested at iE then at Fraunhofer with the new SBIL device installed before final shipment to PGL. Therefore the Enclosure was designed for portability to allow relocation. The design used removable panels and large casters that allowed the entire Enclosure to be positioned over the SBIL device, which because of the size of its granite base, weighs several tons.