Temperature-Nonthermal Relationship Example

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This example appears in the Accelerated life testing reference.


12 electronic devices were put into a continuous accelerated life test and the following data were collected.

ALTA10t1.png

Using ALTA and the T-NT lognormal model, the following parameters were obtained:


[math]\displaystyle{ \begin{align} \widehat{Std}=\ & 0.182558 \\ \widehat{B}=\ & 3729.650303 \\ \widehat{C}=\ & 0.035292 \\ \widehat{n}=\ & 0.776797 \end{align}\,\! }[/math]


A probability plot, with the 2-sided 90% confidence bounds for the use stress levels of 323K and 2V, is shown next.

Probability plot for the use stress levels of 323K and 2V


An acceleration factor plot, in which one of the stresses must be kept constant, can also be obtained. For example, in the following plot, the acceleration factor is plotted versus temperature given a constant voltage of 2V.

Acceleration facton versus temperature given a constant voltage of 2V