February_EDFA_Digital

edfas.org 9 ELECTRONIC DEV ICE FA I LURE ANALYSIS | VOLUME 24 NO . 1 66 mN. However, as in the example before, below these contact forces, the measurements points do not follow well the linear regression line. This observation leads to a new hypothesis in order to improve the model for the crack probability during Fig. 11 Cumulative probability of first oxide cracks for 1000 contact cycles on test structure W06 (a) and W08 (b) using indenter FP05 in Weibull scale as function of contact force (linear regression line: green, 95% confidence band: red). (a) (b) structureW08 themeasurement points arewithin the 95% confidence band for contact forces higher than 82 mN, denoting the high precision of the new AE test method. Also for test structure W06 the measurement points are close to the linear regression line for forces higher than