hi guys. i'm worrying about the oxidation of my etched pcbs and veroboards. i have a few and, after a couple of years, the traces are turned dark brown. is this a problem? what does oxidation do? do i have to worry about?
what can i do to prevent oxidation in my future projects? i read something about tinning the tracks, but i'm not sure,
and it's gonna be a mess with the veros
Oxidation is not that bad in relation to circuit performance, but it is going to be a problem if you want to make modifications to the pcb o to repair, as you'll have to polish the copper in order to be able to solder...
In the RF lab I'm working now we don't treat the copper so it oxidizes quickly, and the circuits work for years.
If you want to tin the pcbs I recommend you liquid tin, is the easiest and cleanest way.
A guy who lives in Roturua (popularly known as sulphur city, guess what it does to copper) had luck giving his boards a thin coat of spraypaint, don't know how well it works.
Awww man, I've been to Rotorua (pretty much on the opposide side of the globe from me). That's one funky place! ;D
Can't escape the rotten eggs anywhere.... I guess if it works there, it will work anywhere. ::)
There are protective sprays (rattle cans) just for that purpose. They are designed in a way that soldering will still work after it's applied, but oxidation is prevented.
I just give them a light spray of lacquer after cleaning off the etch resist, the same lacquer i use for the enclosures, has no negative impact on solderabilty, lacquer flashes off upon contact with the hot iron. Found it works much better then Liquid Tin in the long run, Liquid Tin boards left for any length of time around here become quite difficult to solder, no different then oxidized bare copper.
dave
PS. Testors Transparent Candy Green Lacquer gives a pseudo solder resist look if you can get it to spray properly.
I had mentioned it as a concern in a recent post because I had read a few years ago, I believe in a Paul C post in a forum I was lurking in, that he had some of his early pedals come back for rework due to oxidation before he went to PCBs.
I haven't had any of mine go bad yet but I'm only into this a few years.
True about liquid tin losing its solderability quickly. I have never tried spray laquer, but that sounds like a really good idea.
I used to use this (http://www.jaycar.com.au/productView.asp?ID=NA1002) when I etched a lot. Says its "solder through" but chances are its probably just clear laquer.