Panasonic FC series - leaking? quality gone?
 

New Panasonic FC series cap I got from Digikey, tossed it in the parts bin a year ago. Today, I saw the leads have green corrosion on both leads at the bung?!
It this leaking, yet never used? EEUFC1C392
The datasheet says: "This Series is no longer available for purchase in the country of Japan."

Gosh, is FC's quality has gone to china?

Re: Panasonic FC series - leaking? quality gone?
 

I've seen capacitors leak white, yellow, brown and black colored electrolyte but never green.

Re: Panasonic FC series - leaking? quality gone?
 

That green stuff is corrosion from the leads, suggesting either electrolyte has done it or something else when the capacitor was cleaned.

I've seen this quite a bit on old Nichicon PR series capacitors, and those tend to leak out of their bungs quite frequently after some years. I've also seen this on some new Nichicon PM caps.

Possibly.
What hasn't, these days? :p:

Re: Panasonic FC series - leaking? quality gone?
 

yupp, that greenish colour looks exactly like copper oxide. looks like the copper of the cap leads has somehow become oxidised and it seemed to originate from inside the cap. if it were due to oxidation/corrosion due to environmental storage conditions, the oxidation would be seen randomly around and all over the leads but it seems to be occuring coming out from the leads inside the cap, so something went wrong inside the cap.

if this happened on only one cap, i'd just attribute it to being a bum/lemon cap that escaped qc at the factory. shit happens...

Re: Panasonic FC series - leaking? quality gone?
 

the bung hardens over time - maybe because of an interaction with the electrolyte,
maybe because of the humidity or temperature of the enviroment.

i have seen lots of leaked FC's and mentioned it atleast a few times.
always around the bung, and they are never domed.

i have not seen the same issue on FM or FK.

Re: Panasonic FC series - leaking? quality gone?
 

The bung hasn't even been through reflow or any soldering.
It's a high-end part with AEC-Q200, 5,000hrs 105°C and last time I saw this was on 30 year old Spragues. I emailed Panasonic to see if they will comment.

Panasonic FC series has been my go-to for replacements in vintage gear. Not SMPS where low ESR is essential, but instead for audio gear. I'll have to find something alternate I guess.

Re: Panasonic FC series - leaking? quality gone?
 

What does the datecode on the FC say? I know how to decode Panasonic’s date decoding format and as do other members here. I guess it can’t be that old - probably less than a decade old. Momaka’s Nichicon PMs, going by the original revelation he posted, leaked around four years ago now (after only five years in storage judging by their datecodes). That Panasonic FC would be exhibiting this type of behavior, along with Nichicon PM, is equally confounding. I only know of two types of capacitor “plagues” which caused Japanese electrolytics to leak from the bung with no notable hydrogen gas production - the quaternary ammonium salt plague from the late 80s / early 90s (which should no longer be an issue) and a separate problem from that time frame and a bit later with 85ºC capacitors and SMD capacitors having problems with rubber bung deterioration (and leakage thereafter).

It would be a pity if Panasonic FC ended up having this problem. I know a number of members have used them here in their repairs before, and it would suck if this comes back to bite them.

Re: Panasonic FC series - leaking? quality gone?
 

6201MC, DF is 0.25, ESR is good.

Re: Panasonic FC series - leaking? quality gone?
 

Looks like it was made in either February of 2006 or 2016. I’d hope the former because only new cheapos should leak after 3~4 years of sitting in storage (13~14 years would be more reasonable although still disappointing)...

Re: Panasonic FC series - leaking? quality gone?
 

Yup.
FC is also one of the few series rated for automotive applications. And we all know how "not-so-easy" the environment inside a car can be on components. So I'm really hoping this is just an isolated case or maybe just a bad batch/run of the week at most.

Correct.
What's interesting is that on these caps, the ESR and capacitance were still in spec the last time I checked them a year ago (or was it two now? :p: ) Only reason I've been reluctant to use them is because I don't want them to leak and destroy PCB traces, which electrolyte will easily do. So far, those 16V, 100 uF PM caps have been the only ones I've had issues with. All others (including other sizes/capacitance Nichicon PM) have been OK.

Re: Panasonic FC series - leaking? quality gone?
 

Is that the Panasonic (if not still Matsushita) version of KZG?! Yikes!

Re: Panasonic FC series - leaking? quality gone?
 

stj said he’s seen lots of FCs leak and kc8adu had this happen a while back. This might be normal after a decade or so - just like the quaternary salt capacitors from three to four decades ago.

I remember you observing the case size of the 100µF 16V PMs were 5x11 - bewildering, seeing as how the datasheet says they’re supposed to be 6.3x11. I noted this back then too, but unless they’re actually 6mm, I wonder why they wouldn’t match the datasheet’s specs? Did Nichicon improve the manufacturing process, allowing them to reduce the case size? Hope they’re not counterfeits.

Unlikely. Stj said they’re (the FCs) never domed, only that they leak from the bung. The failure mode is different and I’d guess not as fast. Probably no outgassing either.

Re: Panasonic FC series - leaking? quality gone?
 

all the bad ones had been in use atleast 10years

Re: Panasonic FC series - leaking? quality gone?
 

1st response from Panasonic rep:
"... I would not use a part that had corrosion on the leads. It could effect the performance. Sounds like moisture got into the packaging. Please let me know if you have any questions."

I won't store them in the rain lol :facepalm:
I guess FC's have some seal problem if they are leaking even before being used. Sad.

Re: Panasonic FC series - leaking? quality gone?
 

one thing i'v noticed with leaking caps regardless of make - it's usually the same leg.
i think the negative.

could it be some type of electrolysis drawing the fluid to that side?

Re: Panasonic FC series - leaking? quality gone?
 

had a power supply for an apple 2e i repaired 10 years ago come back to me .
all the fc were leaking from the bung.
unit runs 24/7/365 and cool.
this is not good!

Re: Panasonic FC series - leaking? quality gone?
 

damn and i wanted to get a shitload of 100uf 16v panny fc for recapping audio decoupling caps with better ones. guess i'll remove the item from my shopping cart. any other recommendation for ultra low leakage current gbl based caps for audio decoupliong?

Re: Panasonic FC series - leaking? quality gone?
 

note that they lasted over 87000 hours.
thats continuous.
sounded worse than it was.
but leaking and corroding unused parts?
not good!

Re: Panasonic FC series - leaking? quality gone?
 

Chemi-con LXZ is another gamma butyrolactone based series that seems to match Panasonic FC’s leakage current spec and case sizes going by the datasheet (and they seem to be available at the regular, authorized distributors), although the datasheets suggest the specs may be slightly different for the 100µF 16V models. LXZ is also certified for automotive usage, and has a higher endurance rating. As far as I know, LXZ have no problems with leaking from the bung after long term usage or storage. And in the event that FC retaining the quaternary salt as their solution is the real reason for this problem, Chemi-con issued a confirmation notice stating (over sixteen years ago) that none of their series (in production at the time) use the quaternary salt electrolyte (LXZ included). Link to an old post I made in which the notice is enclosed.

Re: Panasonic FC series - leaking? quality gone?
 

audio decoupling, i like rubycon YXF's - they seen to give better lows.
one day i may bother to lot an esr frequency curve for a few caps,
i have a scope now that has an ethernet interface.