[ASK] About old Sanyo OSCON polymer caps

[BravoV]

Bought bunch of these at local store, as they're industrial excess stock. Even I don't need them now, its just the price was so damn cheap, just < $5 for this 50 pcs of purple caps. 

Measured capacitance are spot on with LCR meter, with ESR at 0.045 Ohm (45 mOhm) @100KHz.

Size is 5mm tall and 10 mm diameter.

Questions :

1. Which type of OSCON is it ? For sure its rated at 105 C as printed, but I can't spot the type.
2. As these are old model, looking at the packaging style, do they rot over time ?


Attached cap's photo below.

[SeanB]

Haven't heard of these degrading with time, and they are used a lot in older server boards, so must be a reliable unit.

[Pjotr]

The only point is that they have silver plated wires. Over time they become unsoldarable due to oxidation/sulphurization. You can overcome this by scraping the wires blank again with a scalpel or something.

[BravoV]

Haven't heard of these degrading with time, and they are used a lot in older server boards, so must be a reliable unit.

The only point is that they have silver plated wires. Over time they become unsoldarable due to oxidation/sulphurization. You can overcome this by scraping the wires blank again with a scalpel or something.

Thanks, noted. 

Wonder why they had to use silver, is that common ?

[DanielS]

Wonder why they had to use silver, is that common ?

The main reason is most likely solderability: clean silver plating wets very easily with most solder alloys.

[BravoV]

The main reason is most likely solderability: clean silver plating wets very easily with most solder alloys.

Whats wrong with tin plating as normal/common lower priced electrolytic cap, does silver is much-much better ?

But yeah, you watch the above photo carefully, I did scraped the pins with sandpaper as they're sort of dull/powdery white looking.

I guess these are > 10 or 20 years old aren't they ?

[TiN]

Never see these fail, they are solid electrolyte, like modern low-esr caps.
I have them high ranked in my "good stuff" list.

And due to environmental issues production of these caps are long gone, unless I miss something. Just so you know before you fit them into your xxxx pieces design (cap sizes/pitch is not same as most other electrolytic caps).

P.S. woa, 1000th post 

[BravoV]

And due to environmental issues production of these caps are long gone, unless I miss something.

What production environmental issues ?  Mind elaborate more ?

Btw, congratz on your #1000 post. 

[Psi]

Yep Sanyo OSCON caps are A class.