Using Vibration and Acceleration Analysis to Improve Reliability

Craig Armenti, Mentor Graphics | 08-02-2017

Deriving the physical constraints and fatigue issues for a design prior to manufacturing is essential to reducing board failure and thereby improving product quality. In harsh environments, fatigue can be responsible for up to 20% of failures. The need to design a reliable product is, of course, not a new concept; however, it has begun to receive greater attention in recent years. Customers have come to expect reliability across the industry spectrum no matter where actual production occurs.

Companies that are known to produce reliable products are rewarded in the marketplace with increased purchases as compared to their non-reliable counterparts. Reliable products have less risk of failure, less field returns and less warranty claims, all of which contribute to higher profitability. It is a given that every product is expected to fail at some point, however premature failures can be mitigated through proper design with attention to potential issues due to vibration and acceleration.

Common Methods of Validation

Industry statistics indicate field failure rates of up to 15–20% in the first year of newly launched electronic products. Most design teams rely on physical testing to determine reliability issues. Physical vibration and acceleration testing, also known as Highly Accelerated Lifecycle Testing or HALT, provides a clear mechanism to ensure reliability of a product and identify potential failures due to environmental factors. This is accomplished by applying a much higher fatigue than the actual product will undergo, thereby forcing failures and identifying weak spots.

The process, however, is costly and destructive, potentially taking months per design to complete. Furthermore, results can vary between testing chambers, possibly concealing accuracy and functional limitations on components that could then fail in the field. With the high cost and increased time-to-market, only a few prototype designs actually go through physical vibration and acceleration testing.

To read this entire article, which appeared in the July 2017 issue of The PCB Design Magazine, click here.