FTMS, traditional

FTMS also has the potential of becoming an important tool for determining molecular structure. Traditionally, mass spectrometry has been rather limited in its ability to determine the structure of an unknown compound unambiguously. Additional structural methods, such as nuclear magnetic resonance or crystallography, are commonly used in conjunction with mass spectrometry to elucidate the identity of a molecule. However, when the amount of sample is severely limited or when the sample is a component in a complex mixture, mass spectrometry is often one of the few analytical techniques that can be used. 

Orthogonal extraction, improvements in TOF/MS resolution, and improvements in electronics have created a new application for TOF/MS in accurate mass measurements [70,71]. Accurate mass applications have traditionally been associated with high-resolution magnetic sector and FTMS systems. The ability to provide accurate mass measurements (+5 ppm) with more cost-effective instrumentation has created potential opportunities in the pharmaceutical industry. Such applications can offer improved selectivity for single-stage instrumentation and metabolite or impurity/degradation product identification, particularly when standard compounds are not available, such as in early drug discovery. 

The basic quality assurance concept for high-density flexible circuits is the same as for other circuit types. However, a difference for high-density flexible circuits is the acceptable defect size, which is one order smaller than that for traditional flexible circuits, necessitating higher inspection capabilities. Furthermore, new high-density flexible circuits contain additional structiues such as flying leads and microbump arrays that require additional inspection capabilities for reliable termination. Exact 3-D accuracy and uniform surface conditions are required. Dimensional allowances are smaller than 0.3 percent, and sometimes 2-ftm accuracy is required. 

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