Wieberneit, M.M.WieberneitLackmann, R.R.Lackmann2022-03-032022-03-031994https://publica.fraunhofer.de/handle/publica/184332This paper deals with a non-destructive and contactless test-method of a digital integrated CMOS circuit via the liquid crystal potential contrast (LCPC) technique. The LCPC has been developed from the well known field-induced DAP-effect leading to a test set-up which is economical and easy to be handled. The test set-up permits the observation of the logical states of internal circuit nodes by different test methods. Apart from usual test methods (DC-mode and AC-mode) a new method being called DEBUG-mode is presented. This mode allows the analysis of the functional behaviour on gate level and the indirect examination of the timing. The performance of a test process including these methods is discussed by means of a faulty part of a circuit. It is pointed out that by this test process the location of failure can be pinpointed on gate level and its origin explained.endigitale integrierte SchaltungFehleranalysekontaktloses Meßverfahrennematischer Flüssigkeitskristalloptisches MeßverfahrenSpannungskontrast621Contactless testing of digital integrated circuits using crystal potential contrastbook article