| Objectives | Background | Approach |
To determine if electrical parameter aging is a potential
concern in the performance assessment of electronic parts.
Aging is defined as occurrence of irreversible changes in materials, parts or systems, which affect their ability to satisfy requested performances. Electrical parameter aging is the occurrence of the irreversible electrical parameter drift over time in an electronic part due to life cycle environmental stresses.There is a concern among some electronic system developers that due to parameter aging, the electrical parameters of their parts may vary to the extent that their equipments cease to operate. For example, in the process of uprating, judgments are made regarding adequacy of margins on electrical parameters. This judgment is based on the electrical test results and it does not usually take into account variations of electrical parameters with time. If parameter aging exists, then the margins on the parameters may be lost with time and that loss needs to be accounted for in the uprating process. Uprated parts which meet specifications marginally in a given application may have a high risk of electrical parameter failures during operation if electrical parameter aging effects exist.
The electrical parameter aging results is important to consider when determining if the electrical parameter margins are sufficient for a particular application. Furthermore, the electrical parameter aging results are important if one needs to develop a custom datasheet of a part for any other purpose such a repackaging.
The work will consist of both theoretical analysis and experimental study. The device electrical models and physical models will be reviewed to identify potential aging mechanisms, and the mechanisms will be related to electrical parameters. In the process, we will identify the key environmental factors that affect the potential mechanisms as those have the potential to cause parameter aging. Based on the theoretical studies we will design and perform experiments on selected parts. The steps of the experiment are:
If necessary, uprating methodologies will be updated to account for parameter aging and the corresponding section of the electronic part selection and management guidebook will be modified.