Going to all polymer from electrolyte -> only ESR and ripple important?

[jackywhatever]

Hi just a newbie question here,

I have a mother board with most caps around the CPU blown.
They are 6.3v 3300u and 6.3v 1200u.

Can I replace them with Polymer caps of same voltage but with much less uF, as long as they have lower ESR and higher ripple?

cause I am seeing a 6.3v 680u Polymer cap having lower ESR and higher ripple than a electrolyte 6.3v 3300u counterpart. Is this normal and is the polymer cap a good replacement?

e.g
6.3v 3300u... 0.012 ohm, ripple 2800mA
6.3v 680u.. (polymer) ... 0.007ohm, 6640mA

6.3v 1200u... 0.028 ohm, ripple 1490mA
6.3v 330u.. (polymer) ... 0.010ohm, 3500mA

[Scenic]

Re: Going to all polymer from electrolyte -> only ESR and ripple important?

depending on the board's design, the capacitance can also matter/be important.
i'm not a poly-guru here though..

[jackywhatever]

Re: Going to all polymer from electrolyte -> only ESR and ripple important?

thank you for your input.
after a lot of googling i came across two forum posts elsewhere:

http://www.capsmod.net/forum/viewthread.php?tid=322 - can a polymer solid capacitor recapped with aluminium electrolytic capacitor
http://capsmod.net/forum/viewthread....extra=page%3D1 - When do you use OSCON caps?

Conclusion is: on a Motherboard use polymer caps only for those right next to the CPU, and only if the board is designed to take polymer caps that way.

worth the time reading it

[boxy]

Re: Going to all polymer from electrolyte -> only ESR and ripple important?

Absolutely not! Too little capacitance is often why they blow in the first place!

Supply ripple voltage is directly proportional to capacitance. Supply ripple voltage is bad. Low ESR cuts down on capacitor self heating due to supply ripple current.

If the ripple voltage is high, the ripple current will be high, so self heating goes back up again and your caps will fail.