Electronic Devices Example

Twelve electronic devices were put into a continuous accelerated test. The accelerated stresses were temperature and voltage, with use level conditions of 328K and 2V respectively. The data obtained is shown in the table below:

Do the following:

Using the T-NT Weibull model analyze the data in ALTA and determine the MTTF and B(10) life for these devices at use level. Determine the upper and lower 90% 2-sided confidence intervals on the results.
Examine the effects of each stress on life.

Solution to Example 2: Electronic Devices Example

The data was analyzed in ALTA and the following MTTF and B(10) life were obtained: (The results are shown in ALTA's QCP in the following figures.)
Figures 6 and 7 below examine the effects of each stress on life, while Figure 8 examines the effects of the combined stresses on the reliability. Specifically, Figure 6 below shows the life vs. voltage plot with temperature held constant at 328K.

Fig. 6: The effects of voltage on life, with temperature held constant.

Figure 7 below shows the life vs temperature plot with voltage held constant at 2V.

Fig. 7: The effects of temperature on life, with voltage held constant.

Figure 8 below shows a 3D plot of reliability (at a constant time) versus both stresses. One can observe that reliability declines slightly faster with the change in temperature than with the change in voltage. Note that in the following plot Stress 1 refers to temperature and Stress 2 refers to voltage.

Fig. 8: The combined effects of voltage and temperature on the reliability, as plotted in ALTA.