When it comes to contamination analysis, things are not always as they appear.
In the failure analysis of electronics assemblies, we are often asked to perform a failure analysis on hardware that has undergone a significant thermal event. Hardware might be burned, melted or covered in debris. Determining a root cause for failure can be extremely difficult when the hardware itself is so damaged that much of the evidence has been destroyed. So, what can you do? Like many things, it depends. The success of the failure analysis depends on the overall degree of damage, the amount and type of secondary damage, and the history of the part. Over the years, we have developed some tools and techniques to get the most out of these challenging failure analysis requests.
The first step in these types of investigations is to manage expectations. Most customers will understand that much of the evidence was destroyed during the thermal event failure and that root cause analysis will be very difficult. It is important to discuss what types of information can be gained, however, and what may not be possible. It is also critical to get as much information as possible about the history of the part and any details about the failure itself. This proactive discussion will help lead the investigation in the “right” direction and avoid going down a path that will not yield useful information. For example, if some of the metallic hardware is corroded, it is important to know the storage environment of the unit, not just temperature and humidity, but also the amount of time the unit was stored and its relative orientation. The product history information is useful to separate damage caused by the failure versus damage that occurred before or after the failure.
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