Template:Example:CD-GLL Weibull

CD GLL-Weibull Example

A sample of 18 units of an electronic component was subjected to temperature and voltage stresses. The temperature was initially set 100K and was then continuously increased to 200K over a period of 20 hours. The temperature was again increased at 120 hours to 300K over a 20 hours period as shown in the next figure.

Temperature profile.

The voltage was initially set 4V and was then increased continuously to 8V over a period of 10 hours. The voltage was again increased at 110 hours to 12V over a 10 hours period as shown in the next figure.

Voltage profile.

The failure times, as entered in ALTA, are shown in the next figure.

The stresses are transformed using an Arrhenius life-stress relationship for temperature, a Power Law life-stress reliationship for voltage and the Weibull distribution as the underlying distribution.

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The estimated model parameters are shown next.

[math]\displaystyle{ \begin{align} & \widehat{\beta }= & 3.5073 \\ & \widehat{{{\alpha }_{0}}}= & -1.3773 \\ & \widehat{{{\alpha }_{1}}}= & 450.46 \\ & \widehat{{{\alpha }_{2}}}= & 1.98 \end{align} }[/math]

The use level (temperature = 100K, voltage = 4V) reliability plot is shown in the next figure.

Reliability plot at normal use conditions (100K and 4V).