solid polymer electrolytic capacitor go boom?

[eccerr0r]

Anyone had a solid polymer capacitor fail for whatever reason?

How do they fail? Do they explode, go open, short out, ?

How about for different reasons: forcing excessive ripple current, overheating, voltage too high, reverse voltage?

Just wondering about the causes for a potential shorted solid polymer capacitor... trying to debug a board that has a ~4Ω "short" on a track... it may or may not be a capacitor but was wondering what if it were...

[stj]

Re: solid polymer electrolytic capacitor go boom?

i watched a video of trying to fuck a bunch of them,
guy ran them at rated voltage in reverse polarity, they went dead short and just cooked till the leads melted

that said, there was a guy on another forum a few years ago, re-capped a mobo and put one in backwards, it exploded and put black tar-like goo all over the place.

so it may depend on the internal design/manufacturer.

[eccerr0r]

Re: solid polymer electrolytic capacitor go boom?

hmm...also curious what happens if they get overheated or overvoltaged. Unlike a "wet" capacitor, they don't have a liquid to boil off so I can't extrapolate a regular aluminum wet capacitor over. Reverse polarity it seems very similar to an aluminum wet, except that one case where the internal resistance got so low the leads were more resistive

[stj]

Re: solid polymer electrolytic capacitor go boom?

well given my previous post, i suspect they get very hot and then it's down to the specific design whether it stays in one piece or expands and blows the can off

[AleXis6]

Re: solid polymer electrolytic capacitor go boom?

hmm...also curious what happens if they get overheated or overvoltaged

I have several unbranded without any prints can do some experiments.
what the design do you suggest?
can try overvoltage or reverse polarity

[stj]

Re: solid polymer electrolytic capacitor go boom?

put a bowl over it or do it outside.
you can thank me later!

[PeteS in CA]

Re: solid polymer electrolytic capacitor go boom?

put a bowl over it or do it outside.
you can thank me later!

I recently saw a polymer cap that had been installed reverse polarity. But for being inside the P/S case it would have launched. The case limited the height the cap attained.

About 15 years ago (time's fun when you're having flies!) when I was torture testing lytics, I tortured a couple of polymers - probably ran them at ~8X rated ripple current - and the things just kept running. I don't remember whether, after several thousand hours, the things even reached double their initial impedance.

[eccerr0r]

Re: solid polymer electrolytic capacitor go boom?

looks like reverse polarity has been well tested, and looks like high ripple current are even tolerated...

wonder about overvoltage and high ambient heat now?

[PeteS in CA]

Re: solid polymer electrolytic capacitor go boom?

Polymers don't have a liquid electrolyte that could cause venting or evaporate.

[stj]

Re: solid polymer electrolytic capacitor go boom?

you say that, but if the chemical outgasses or there is an air-pocket in the end of the can then expansion can still blow the can off the contents

[PeteS in CA]

Re: solid polymer electrolytic capacitor go boom?

Since in both polymer and liquid electrolyte capacitors the dielectric is aluminum oxide, not the polymer or liquid electrolyte, are the frequency characteristics for the two types substantially different? I couldn't find charts.