Trelic’s picture of the week 02/2018

Every-day failure analysis

 

When a product fails in use, it is important to analyse what went wrong and why. Similarly, when a product is reliability tested during its design phase, it is crucial to know what caused failures during testing. In failure analysis a cause for failure is analysed. Without proper failure analysis it is impossible to know what the product’s weakest points are and how to improve them.

Failure analysis can be done with several analysis methods. Which method is the most suitable depends on the failed structure, test method used, and type of the failure seen. In electronics, commonly used methods are for example visual examination, electrical measurements, x-ray or cross-sections combined with microscopy.

Here is an every-day example of such an analysis. We had quite a lot of fun at the office with this one!

One morning Sanna started to complain that her laptop makes a weird noise when it was moved or wobbled from side to side. It sounded like a circuit card was loose inside her laptop. The laptop was functional, but having something loose inside the laptop did not sound like a good idea. One would never know what harm such a loose component could do!

We started our analysis by trying to locate the failure according to the noise. Then a lot of screws were opened. Finally, we could see inside the laptop.

And there was no loose circuit card. There was a coin!!!

This example shows how the user may be the main source of failures, as they do not always follow the user instructions (in this case a laptop sleeve would probably be a clever idea to protect the laptop from all the clutter in Sanna’s backpack). Misuse can cause some quite strange failures which are also difficult to predict. However, finding new and strange things often makes the failure analysis fun.