vacuum-safe laptops ?
shaddack at ns.arachne.cz
Sat Jul 17 16:13:13 PDT 2004
On Sat, 17 Jul 2004, Tyler Durden wrote:
> Sorry to need educating once again, but I had assumed can-shaped capacitors
> were gone from laptops in lieu of surface mount. Anyone know? (I don't own a
The can caps can be surface-mounted as well. The leads then look
different, but the inside is still the same: a metal can with etched
aluminum strips and an insulator soaked with electrolyte. The magic smoke
they are filled with also has the same color and smell as their non-SMD
See also http://www.elna.co.jp/en/ct/c_al01.htm for brief description of
liquid-electrolyte aluminum capacitors.
There are also some more modern constructions, where the electrolyte is
solid-state. (The tantalum capacitors, which are more common in SMD form
than the aluminum ones, use MnO2 as electrolyte and Ta2O5 as insulator.
The added advantage here is that during a breakdown, the MnO2 layer
locally overheats and is converted to less conductive Mn2O3, which causes
the breakdown to "heal". Similar mechanism is used in capacitors with
solid-state plastic electrolyte.)
I suppose the solid-state caps could be much more reliable in the
conditions of rapid pressure changes, if they won't have moisture or air
trapped inside their construction.
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