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Client: IBM Corporation, T J Watson Research Center
Location: Yorktown Heights, New York
Project Description: Vibration Sensitivity Testing of Direct-Write Lithography
Equipment
IBM developed lithography equipment for producing small geometry wafers. It was
necessary to understand the sensitivity of the tools to facility vibrations.
Vibration Engineering Consultants, Inc. conducted extensive on-site testing of the
components to establish the loss of precision (resolution) as a direct function of base
(floor) vibration. The project involved actual testing using electrodynamic shakers as the
force exciters, and post-test analysis using Vibration Engineering Consultants' own
software package, PCMODAL, to ultimately develop curves providing permissible
displacement, velocity and acceleration linear spectra. The project established the
permissible facility vibration criteria for selected IBM production equipment.
Client: Brookhaven National Laboratories
Location: Upton, Long Island, New York
Project Description: Facility Analysis and Conceptual Design Services For the
Neutral Beam Test Facility (NBTF)
The NBTF is a new linear accelerator facility being constructed adjacent to existing
similar facilities. The facility operations are extremely sensitive to on-site vibrations
and vibrations caused by support equipment. An overall displacement criteria for
permissible target deviation not to exceed roughly 3 microns was established.
Vibration Engineering Consultants, Inc. was retained to measure the site vibration
characteristics, and provide analytical and design recommendations in a conceptual form to
Brookhaven and the Architect/Engineer. To that end, on-site measurements were made to
establish the proposed site vibration characteristics. In addition, as the support
machinery to be used in the NBTF was essentially the same as existed in the LINAC
accelerator, measurements were made of the vibration signatures of the support pumps,
compressors and motors. This data was used in an evaluation of the conceptual design of
the NBTF and design recommendations were offered regarding foundation design, equipment
isolation, and most importantly, the quadrupole magnet monuments. Post-construction tests
were conducted to confirm the engineering criteria had been met.
Client: IBM Corporation
Location: Essex Junction, Vermont
Project Description: Analysis and Retrofitting of Sensitive Equipment Laboratory at
the General Technology Division, Building 967
IBM Corporation relocated the entire wafer inspection laboratory from Building 970
which was on grade, to the second floor of Building 967. Vibration Engineering
Consultants, Inc. was charged with evaluating whether the equipment, particularly the
scanning electron microscopes (SEM), would function on an elevated floor. Any remedial
design measures were also the responsibility of the Consultant.
Measurements were made in Building 970 in which all the equipment was presently
contained and functioning adequately. Measurements in Building 967-2 showed considerably
higher vibrations. In order to achieve acceptable levels of vibration, special isolation
systems were designed and some modifications were made to the equipment to harden them
against the effects of vibration. After the installations began, measurements were made to
ensure that the vibration levels were as designed and to verify equipment operability.
Client: Systonics, Inc./MIT Lincoln Laboratories
Location: Lexington, Massachusetts
Project Description: Vibration Testing and Retrofit Design of the Massachusetts
Institute of Technology Lincoln Laboratories Clean Room in Bedford, Massachusetts
Lincoln Laboratories is refurbishing their clean rooms and has purchased new, greater
resolution wafer fabrication equipment for the laboratory. Perkin Elmer Microalign M300
series aligners were purchased and installed in the clean rooms. Vibration Engineering
Consultants was retained to measure the existing floor vibration levels in the room and
compare the data to the vibration acceptability envelopes provided by Perkin Elmer for
this aligner series.
The clean room has a raised floor construction with the exhaust plenum located
beneath. This caused significant vibration levels throughout the floor and indicated that
the aligners would not function well in the existing environment. We recommended placement
of the aligners directly on the slab beneath and design of a rigid pedestal from the slab
to the level of the raised floor which will ensure the operability of the component. |
