@Jack98
Within a typical aluminium SMD Electroytic Capacitor a small aqueous solution of sodium borate is used as an Electrolyte - this hydroxide solution is a mild alkaline (PH of about 8).
Now I went
into depth here about how alkalines and hydroxides effect our beloved amiga but the short of it is this
1. Copper
Although a great conductor it is also a verilent oxidzing metal. This means it will react with oxygen or anything that offers the promise of oxygen.... think of it like the slut of conductive metals =)
2. Hydroxide is a Mild Oxidizer
Oh dear... we have an oxidizing metal and this oxidizing hydroxide silo waiting to leak... this will expediate things as you can imagine... kinda like having a keg of beer and throwing a couple of bottles of vodka in to make sure its gets the party going
3. Hydroxide to Peroxide
Once a capacitor leak begins - pending on the length of time and temperature this can react with the atmosphere to form a peroxide - now, peroxide is verilent oxidizer and will hunt down anthing that it can react with....
hmmmm what happens when (copper boy) an oxidizing metal - meets (peroxide girl) a verilent oxidizer?...... well I can tell you... they a have a very short but intense relationship that ends up destroying some of copper boys tracks and in the process spending all of peroxide girls energy - both are left green and very bitter...
4. But theres more to come....
The real problem here is the copper - once the reaction has started it becomes copper hydroxide - this is what chemo-boffs call "mildly
amphoteric" thats to say it can react as an acid AND as a Base - so after the break up with peroxide girl, our dear copper boy had kinda gone.... well Bi!
So whats this mean... well unfortunately theres no rainbow in this picture - copper being in an amphoteric state means it will contiune to react with itself - causing more hydroxide - this is syndromic reaction and will continue this for as long as there is free oxygen and or mosture available - the only way to stop this is to neutralize the Hydroxide and thus negate coppers amphoteric state..
Okay Zetr0... it sounds Hardcore.. so how do we fix it??
Okay.... so right about now things don't look so good - but there is a way - and its very simple process (we like these)
to neutralize an Alkaline (weak base) we need to use a weak Acid something plentyfull and controllable - Lemon Juice - for that Zesty Fresh morning smell or Spirit Vingar for that irristable moment where only a greasy bag-o-chips will do!
So - which ever you prefer - douse the effected area liberally with your chosen acetic acid and leave for about 5 minutes... let them get to know each other =D
Are we there yet?
Now... the hydroxide / peroxide will be neutralized by the acetic acid - but copper will still just as much react to a weak acid as it will to a weak base - so we need to wash off the acid -
8BitBubsy suggest the IPA - and I cannot lie - its great stuff - expensive - but good... however if you wanna save a few pennies and get the job done.... pop into pound land or similar and pick up some pre-diluted car screen wash =)
You will find that its less than a 10th the price per volume and its made up of diluted IPA with some non-smear detergents .... perfect for cleaning up after the vinigar / lemon juice =D
So... what next?
so now we are all clean - dry and the new capactor is soldered in.... if theres any exposed or bare copper then I suggest some PCB protectorant (comes in a handy spray can) and can be sprayed in the area protecting bare copper from both atmospheric oxidization and should that a capacitor close by ever leak again.
damn.... this was supposed to be the short version.... - anyhoo that should just about cover it
