Multilayer Ceramic Capacitors
Return to SatCure-Focus Home page.
Capacitor failure can have catastrophic effects. Between 1985 and 1988 when I was carrying out research I came across several instances where equipment had caught fire as a direct result of MLC capacitor failure. Here is a picture of a circuit board which was badly damaged when the 47nF decoupling capacitor next to an I.C. went incandescent.
In another instance an identical board assembly had a 25mm diameter hole burned right through it.
|
|
In a previous article I discussed MLC capacitor failure causes. Here is a picture of a capacitor which suffered thermal stress. We soldered the capacitor to a PCB by hand then plunged it into cold water. This is an extreme measure but we wanted to see what thermal stress cracking would look like.
|
|
|
Here is a magnified view of the same capacitor. See the fracture.
|
|
|
And this is a cross-section of a capacitor which suffered similar thermal stress.
Note the crack which looks like the profile of a mountain.
|
To read the full story please buy my eBook "Surface Mount Technology - Design Guidelines" from The Cool Book Shop.
