Mechanical behavior and damage of tridimensional multilayered ceramics-tungsten power electronic substrates

Since few years a 3D electric lines is developed. But new applications will be to expose this circuit to high variation of temperature and use them for electronic power. Circuits lines are made of tungsten and insulation in alumina. These materials have different behavior. That difference implies mechanics stress and stress singularities. Some stress concentration can fracture materials or interface between them. Alumina is a brittle material. We need to know his fracture behavior. A statistic model is already used: Weibull model. The idea is to break about hundred samples and to related the probabilities to break of alumina used in the circuit versus stress.