Problem with (my) pertinax pcb's from mike?

[Nomical]

I got a problem with my pcb's and i couldn't find the answer here.

When i look at them, i could swear something is degrading. I don't know how to explain what i see and i can't take a digital picture of it. It looks as if it's either corroding/oxidising or that the tracks are dissolving.

Has anyone had this too?

And how can i stop this? What's the best solution?

Should i get some of the special coating stuff for electronics that i can spray on the pcb's, should i use simple (ultrastrong) hairspray or is there even a better solution?

Or is it something i don't have to worry about?

I thought Mike also sprayed something on the pcb's to stop the oxidation of the tracks, pads and planes. Or is this not sufficient anymore after soldering everything?

Cheers,

C.

[d2k]

Hey Nomical...

Not had this prob myself I must say...

I just spray the pcbs after drilling with flux spray - seems to protect it nice and make soldering easier. If u wanted to go even further u could tin plate the tracks prior to this...

Or, just cover all the tracks with thin covering of solder to protect em...

If all components are already stuffed, I think u can still spray the track side with a protective laquer...

Hairspray? never heard of that1 lol :P

Best

Dan

[Nomical]

I wasn't all to certain about the hairspray :D

A friend of mine does electronics also for his study/school and he recommended buying hairspray instead of (expensive) electronics spray for protection.

I thought it was strange, seems like others never heard of it too... :D

I'll try and lend a digital camera and post a picture of what i'm seeing.

By the way, everything is soldered but the ic's aren't stuffed into the sockets yet. So i'll wind up spraying those pcb's with some kind of protective stuff.

Thanks for the ideas.

Cheers,

C.

[d2k]

A friend of mine does electronics also for his study/school and he recommended buying hairspray instead of (expensive) electronics spray for protection.

ahh, could be fine then if it was said by some1 who knows what they're talking about - i'm no experienced pcb maker by any means :P

[smashtv]

Heya Nomical!

PCBs will corrode with exposure to air, faster if you live near the ocean (salt air) , this is normal.

Several methods:

If you already have your soldering done, you can:

Spray the boards with laquer, spray paint (clear coat or color), or anything you want that will seal it up.  Anything water soluble (like hairspray) will break down and not protect your board after a while.

Pros: Easy, quick, and cheap.

Cons: Very difficult (and stinky/toxic) if you ever have to solder on the board again.

OR

Simply "solder tin" the boards by spreading solder around all exposed copper with your soldering iron.  

Pros: if you built the board you already have everything you need, repairs or future soldering is quick and you don't have to strip any sealers off before soldering.

Cons: if not done carefully you can create a solder bridge/short.  Does not work well if the board is heavily oxidised.

The best thing ever for preparing copper for soldering is a soft eraser (like a drafting eraser or the kind on the end of a pencil).  This takes away only the corrosion and does not damage the copper unlike other methods.

On flux:  This can be an issue for some circuits, but mostly with analog stuff.  The flux does pass some electricity, not enough usually to cause problems with digital stuff where the levels are high.  A great example is an Oktava condenser mic I recently modified, cleaning the flux from the board after re-working it caused a the noise floor to drop over 3db!

Oxidation was a huge issue for me when I started the board thing, so the boards I sell are silver alloy dip tinned.  They don't corrode under normal use/storage and are actually easier to solder than bare copper.

Sorry for the long post!

Smash

[moebius]

Hi,

Well, I think that most of us do like LONG INFORMATIVE posts, like yours Smash ;)

There are these protective/ (and) solder thru laquers on the market. Any comments on those?

I can really recommend spray flux, as it makes soldering so much easier.. A hit for those who think they are lousy at soldering. And I think it can be washed away with tap water.

bye Samppa

[smashtv]

Well, I think that most of us do like LONG INFORMATIVE posts, like yours Smash ;)

Cool, hopefully my novels aren't putting everyone to sleep! ;)

There are these protective/ (and) solder thru laquers on the market. Any comments on those?

I have not used these, but I hear they work very well.

I can really recommend spray flux, as it makes soldering so much easier.. A hit for those who think they are lousy at soldering. And I think it can be washed away with tap water.

Everyone who has used the Conrad stuff I have talked to really likes it.  It is not available in the US so I have not tried it yet.  I am wondering if this breaks down over time or if Nomical washed this off of his boards before soldering, since this is what Mike uses to protect his boards before shipping.

I seriously doubt the spray flux has the same conductive qualities/problems as flux left on the board from the core of the solder, but I don't know.  

A note about all of this stuff:  Anything you use while soldering has chemicals in it that are bad for you, including the solder, flux etc.  <good> Solder has lead in it, lead poisoning is cumulative over your lifetime, causes memory loss, birth defects, and other bad things.  Always solder in a well ventilated area.  Never eat, smoke, stick your fingers in your mouth, etc. directly after soldering.  Scrub your hands like a surgeon immediately after soldering, and try not to touch anything else before you wash (you can transfer trace amounts of lead to other surfaces from your hands).  

I do a lot of my soldering with latex gloves on.  Call me paranoid, but I would hate to think that I did something this simple in the first years of my boys' life that would effect his health/brain development.

Have fun!

Smash

[TK.]

Cool, hopefully my novels aren't putting everyone to sleep! ;)

Far from it - they are the highlights of this forum! :-)

Best Regards, Thorsten.

[Nomical]

So if i understand correctly, it's best to spray the pcb's with that flux spray stuff when you've already soldered your pcb's, right?

And the spray that is best (or has good results) is the one you can buy at Conrad? Ordering from Conrad is no problem over here. Does anyone know which spray it is, brand or type or Conrad number?

One thing that's not too clear though is how to get the oxidated copper of the pcb's before i spray it. Something about the erasers on pencils? Can i use that method safely to remove the copper that has been oxidated?

Thanks for the info already!!!

Cheers,

C.

[moebius]

No,

Flux spray should be used before soldering.. It's the stuff that makes your solder _FLOW_ and gives you beatiful solder joints. AND it as Smash said (and I have seen some posts somewhere from synth-DIY people, saying that some circuits, propably VCO designs, didn't work at all, before flux was removed!) propably has some conductive properties, so it should be removed from board after soldering.

But there are some kind of protective laquer products to be aplied before soldering, which protect the board from oxidation AND ease your soldering. Here in Finland a company called Bebek has this Cramolin Solderlac125.. haven't tried it anyway..

Bye, samppa

//edit: more comments :)

Well, propably that pencil eraser thing is ok. But I think not that typical red rubber one, but the blue.. maybe even fine wirewool could be used? I'm not sure at all, as it's so easy to break those fine copper traces??!

[LO]

A good protective lacquer:

Electrolube- CPL (clear protective Lacquer)

comes in a 200ml can for the equiv of about 5-6 euro's

spray the board after etching, solder, then re-spray. EASY.

I use steel-wool for cleaning tracks but this is not actually a good thing to use as the steel could make the copper corrode. ( I think? cant remember my school lessons!)

[Nomical]

No,

Flux spray should be used before soldering.. It's the stuff that makes your solder _FLOW_ and gives you beatiful solder joints. AND it as Smash said (and I have seen some posts somewhere from synth-DIY people, saying that some circuits, propably VCO designs, didn't work at all, before flux was removed!) propably has some conductive properties, so it should be removed from board after soldering.

But there are some kind of protective laquer products to be aplied before soldering, which protect the board from oxidation AND ease your soldering. Here in Finland a company called Bebek has this Cramolin Solderlac125.. haven't tried it anyway..

Bye, samppa

//edit: more comments :)

Well, propably that pencil eraser thing is ok. But I think not that typical red rubber one, but the blue.. maybe even fine wirewool could be used? I'm not sure at all, as it's so easy to break those fine copper traces??!

A good protective lacquer:

Electrolube- CPL (clear protective Lacquer)

comes in a 200ml can for the equiv of about 5-6 euro's

spray the board after etching, solder, then re-spray. EASY.

I use steel-wool for cleaning tracks but this is not actually a good thing to use as the steel could make the copper corrode. ( I think? cant remember my school lessons!)

Now i'm lost... ;D

You're both talking about things that i have to do before the soldering process. But i've already soldered everything.

Just to sum it up:

So i must get this protective laquer stuff, polish of the oxidated copper with something that doesn't damage the rest of the copper and put the laquer stuff on the pcb and than it will be ok?

Thank you ;D

Cheers,

C.

[smashtv]

Now i'm lost... ;D

You're both talking about things that i have to do before the soldering process. But i've already soldered everything.

Just to sum it up:

So i must get this protective laquer stuff, polish of the oxidated copper with something that doesn't damage the rest of the copper and put the laquer stuff on the pcb and than it will be ok?

hehe yes.  Clean the oxidation that you can reach off of the board and spray it with laquer.

Any eraser should do, I have used normal red/pink pencil erasers, as well as white and blue drafting erasers.

Ultra fine steel wool can be used (look for ooo or oooo grade), but it can start the corrosion process if the board is not sealed or plated with something immediately after cleaning.  I use steel wool on prototype boards here instead of acetone when I can, it's just more environmentally friendly and doesnt leave my head swimming from vapor/odor.  It would be almost impossible to use steel wool on a board that has been soldered.

Have fun!

SmashTV

[Nomical]

What is the German translation of 'protective laquer for pcb's'? Or what's it called on the Reichelt website?

It's a damn shame that Reichelt's site is only viewable in German, not in English. Why is that anyway, they do international orders.

And @ Smash TV, what's the name of the stuff they sell at Conrad? Is this the one: Positive

Thanks,

C.

[TK.]

What is the German translation of 'protective laquer for pcb's'? Or what's it called on the Reichelt website?

It's called "Lötlack"

(loetlack w/o umlaut)

Reichelt ordering #"Kontakt 227" (200 ml) or #"Kontakt 228" (400 ml)

Mike uses the same spray for his PCBs - maybe it wasn't enough on yours (my PCBs are still ok after more than one year)

Best Regards, Thorsten.