Little... black... thing in a hard drive

wogi

So I had a hard drive that failed- I took the opportunity to rip it apart- and I noticed something I'd never seen before. Inside, on the upper casing, was a little plastic container that broke away pretty easily. on the side that was glued down, there was a piece of filter material that came away with a knife. I cut it away, and there was this tiny black disk in there, which seems to be pretty brittle. It feels like charcoal... is that what it is? Anyone have any ideas?

Viscountalpha

I'm betting this is a filter. You can't just be letting large particles into a hard drive. The manufacturers have to repair and make platter based hard drives in clean rooms. I used to work in a repair operation and my dad was a senior engineer at Fujitsu for nearly 20 years.

You have to understand, back in 1994 they were packing these bits tightly, even more so now. The head floats less then a fraction of a millimeter off the disk. So we have to keep particles from dropping onto that platter messing up your wonderfully stacked bits.
perpendicular recording
http://www.physorg.com/news3588.html

And now you know.

(probably more then you wanted)

wogi

No, I'm a bit of a nerd- so the more info the better. :P

So that's what it likely is then, just a charcoal air filter?

Pretty sweet you might say....

Ruckus

It might be a desiccant adsorbent for moisture control.