Localization of temperature sensitive areas on analog circuits
We introduce a novel easy to apply method to detect critical temperature sensitive areas on analog circuits. Our method is based on heat diffusion on a silicon micro-chip: the corners of a temperature sensitive micro-chip are heated up directly by ESD diodes or infrared laser light. This heat stimulus at the corners results in an inhomogeneous temperature distribution. Thus, the temperature is a function in time and space. The elapsed time to change the chip status from fail to pass as a reaction to the heat stimulus correlates with the distance to the heat source. This correlation is extracted from COMSOL simulations and experimental results. A numerical program based on that correlation succeeded in localization of the temperature sensitive chip module. Micro-chips affected by corner MOSFETs in the subthreshold regime are used to demonstrate our method.
analog circuits heat diffusion failure analysis corner device