Unknown polymers

[Behemot]

Found some polys on dead ASUS P5L 1394 mobo. They are labeled 680uF 4V FL with black stripe left from this text, no color marking or manufacturer logo. Who makes these? If you cannot recognize it, I will provide image later

[PCBONEZ]

Re: Unknown polymers

They aren't poly.
They are Panasonic FL.
Should see the [M] for Matsushita somewhere on them.
That's the logo.
The brackets around the M are different than the (M) that means +/-20%.

[Behemot]

Re: Unknown polymers

No no, there is no Matshishita logo, I would recognize it :-) They even use the can typical for polymers, with no vent or so.

[mockingbird]

Re: Unknown polymers

Yes, there are polymer FL, I have seen them.

[Behemot]

Re: Unknown polymers

Were they normally manufacturedd, or is it custom production? You probably don't have datasheet…

[lti]

Re: Unknown polymers

I've seen these before, but the ones I saw had an X-shaped vent.

[PCBONEZ]

Re: Unknown polymers

Panasonic FL are electrolytic.
Not all lytics have vents.
It's not uncommon for those odd ass 680uF 4v lytics to not have vents.
OST has been doing that for ages.
I've seen Panny FL's like that.
I've seen Rubycon ZL like that. [By RAM slots on some Dell boards.]
And as recently discovered in another thread with TMV, Chemicon does it too.
Not all that unusual...
.

[POM_MJ]

Re: Unknown polymers

Panasonic FL are electrolytic.
Not all lytics have vents.
It's not uncommon for those odd ass 680uF 4v lytics to not have vents.
OST has been doing that for ages.
I've seen Panny FL's like that.
I've seen Rubycon ZL like that. [By RAM slots on some Dell boards.]
And as recently discovered in another thread with TMV, Chemicon does it too.
Not all that unusual...
.

Correct.
link to reference V-FK, V-FP presentation.
http://www.ttieurope.com/docs/IO/175...esentation.pdf

[PCBONEZ]

Re: Unknown polymers

Interestingly I was just thinking about this then someone posted a nice pic of it.
Here:
https://www.badcaps.net/forum/showth...374#post165374

See those round holes?
Those are basically weakly glued in rubber plugs in through-holes.
That's another way they accomplish pressure relief but it's usually done on much larger caps.
.

[lti]

Re: Unknown polymers

I posted those pictures. I just thought that those caps were either very old or very poor quality.
Also, I have a 2200uF 35V Nichicon VX that has the same pressure relief, but it is an axial cap so there is no vent.

[Behemot]

Re: Unknown polymers

OK, I think I will canibalize them, but sacrifice one piece and have a look inside to discover what they really are

[Behemot]

Re: Unknown polymers

Well I did not open any polymer before, but did liquid electrolytic and this seems as one to me. The paper is wet from electrolyte.

[PCBONEZ]

Re: Unknown polymers

Those are indeed Panasonic FL and as I told you they are lytics, not polymer.

I didn't know you were looking at that style marking on SMD caps.
Matsushita logo is normally only seen on caps with sleeves.

[PCBONEZ]

Re: Unknown polymers

Sleeves are only a way to mark caps. That's all.
Doesn't tell you what technology they are.

Ages ago MOST caps were marked by direct printing on the end [or side] like like that FL you took apart.
Polymer caps didn't even exist yet.

Then they developed heat-shrinkable plastics and started using sleeves to mark caps because it was cheaper and easier in an assembly line situation.

Since then advances in printing technology and automated equipment has made direct printing cheaper than and as easy as using sleeves -but- there are scads of already existing cap sleeving equipment that is already paid for or for sale cheap.

Having a sleeve or not is NOT a reliable way to tell if you are looking at a lytic or a poly.
- Sanyo OS-CON Polymers typically [historically] have sleeves.
- Nichicon HD series radial Electrolytics without sleeves show up all the time.
[I see HD like that off-on in all ages of equipment. I suspect one of Nichicon's factories simply doesn't sleeve the HD series so some % of their HD production is sleeveless but it could be some kind of special order too, not sure.]
- There are other examples if you look around...

Having a top vent or not isn't 100% reliable either.
- If they consider it small enough [or the chemistry is such that] it isn't likely to explode from gas formation they won't use a vent.
- Hybrid Polymers [aka Functional Polymers] often have vents because in addition to the polymer they still have some wet electrolyte.
- Some SMD's have a vent method built into the base which you will never see.
- I've also seen mechanical drawings of cap construction that for the small [5-6mm] cans showed vents pressed into the sides of the can where it would be under the sleeve. The idea is the gas will pass between the sleeve and the can.
-- So, there's a few times when no vent on top doesn't mean no vent at all.

The Panny FL you just dissected breaks all the 'rules'.
That's because they aren't actually rules, they are just typical.
.