A Review of 12 Years of Performance of an Automatic Standard Cell Test Facility

Operating experience and difficulties encountered in a 12-year use of the automatic standard cell test facility are reviewed. The facility was designed to acommodate 40 cells on test and to resolve the difference between the voltage of each test cell and that of a reference cell to 0.1 ¿V. The large amount of data obtained has led to a more complete characterization of cell performance and has identified an unexpected impulse-type response in unsaturated standard cells exposed to a varying thermal environment. Difficulties of various types have been expected over the operating period. An unexpected type of failure occurred, however, with snapaction switches used on low-voltage logic lines, and similar failures may be anticipated in new designs.