(U.S.) Joint Electron Device Engineering Council Soild State Technology Association
Scope
Analysis of reliability experiments depends extensively on failure
statistics, and a commonly used failure distribution is the normal
distribution after natural logarithms of the failure times have
been calculated. Lognormal distributions and the associated
statistics are used by analysts working in semiconductor
reliability to interpret and communicate results from failure
experiments. Unfortunately, many individuals who lack a sufficient
background in statistical-methods are using the techniques; errors
in usage and interpretation are abundant. Frequently, the number
of data points in a distribution is small (i.e., less than 20)
Statistical tools for analyzing small samples of data are not
available to all. who need them. The result is that less than
optimum techniques are being used on calculators.