I've recently started etching my own pcbs, using toner transfer onto copper-clad -> etching with cupric chloride. I'm wondering, do I need to take steps (spraying with lacquer or something) to ensure the boards will last? Has anyone had troubles with corrosion eating traces away over time or similar issues?
long term reliability of diy etched pcbs
- Thread starter dfuruta
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Help Support GroupDIY Audio Forum:
Sleeper
Well-known member
I would suggest you be sure and clean the boards as thoroughly as you can and yes, hit them with some kind of conformol coating. Uncoated boards are going to corrode. MG makes actual "conformal coating" but I've been using clear lacquer mostly and Krylon "crystal clear" acrylic finish for 10 years and my boards haven't had any electronic failures. Not due to the traces breaking down.
with the home etched boards, you have to solder a bit more carefully and make sure you haven't ripped up your copper when you drilled your holes. Otherwise... I've got some early 70's Electrodyne stuff with pretty much house-etched looking circuit boards. No thru plating or anything. It' works great. It's coated too.
You do need a bit more heat to do repairs, because you have to burn off the lacquer first. And you've got to clean off that residue before you resolder.
Other than that.
All good
Sleeper
with the home etched boards, you have to solder a bit more carefully and make sure you haven't ripped up your copper when you drilled your holes. Otherwise... I've got some early 70's Electrodyne stuff with pretty much house-etched looking circuit boards. No thru plating or anything. It' works great. It's coated too.
You do need a bit more heat to do repairs, because you have to burn off the lacquer first. And you've got to clean off that residue before you resolder.
Other than that.
All good
Sleeper
straypacket
Well-known member
I'm assuming the lacquer should be applied before soldering the components - is that correct?
I have a Kent geetar amp circa 1965. Garage sale, and that garage was damp. Really cheap uncleaned uncoated PCB. It's fine.
If you throw your gear in the sea, you have problems. Any home/studio life, you are fine. Damp garage is poor, but other things like connectors will crud-up before the PCB.
If you throw your gear in the sea, you have problems. Any home/studio life, you are fine. Damp garage is poor, but other things like connectors will crud-up before the PCB.
Sleeper
Well-known member
NO!straypacket said:
the note on heating was for repairs.
procedure is:
Clean with denatured alcohol, or circuit board cleaner.
Solder
Clean again to remove excess flux
Coat with lacquer.
PRR is always right, so even this is probably unnecessary, but I'd guess the board he's talking about was at least "tinned"
OTOH it certainly doesn't hurt
and
it probably has some positive noise effect on very high impedance circuitry that is prone to problems with moisture, like PCBs you might build into a condenser mic assaulted by humid singer breath
straypacket
Well-known member
humid singer breath... ick.
That's worse than having to count in for the drummer...or go buy him sticks when he arrives at the gig without them - both true stories
That's worse than having to count in for the drummer...or go buy him sticks when he arrives at the gig without them - both true stories
Timothytitus88
Well-known member
There are some spray lacquers that are made specifically for PCB's and for soldering through.
Bit of a discussion about self etching here:
http://www.groupdiy.com/index.php?topic=47954.0
T
Lots of good information!
Has anyone had an opposite experience from PRR–tracks getting eaten with time? If not, it'd be a lot simpler to not worry about it! And, I'm sure my lungs will be happy not dealing with another nasty substance.
Maybe someone will find this useful: instead of using an iron to transfer the toner, I've been using a t-shirt heat press. The temperature is adjustable (around 300 F seems to be best with my printer), and it works well as long as the board is cleaned thoroughly first.
Has anyone had an opposite experience from PRR–tracks getting eaten with time? If not, it'd be a lot simpler to not worry about it! And, I'm sure my lungs will be happy not dealing with another nasty substance.
Maybe someone will find this useful: instead of using an iron to transfer the toner, I've been using a t-shirt heat press. The temperature is adjustable (around 300 F seems to be best with my printer), and it works well as long as the board is cleaned thoroughly first.
home_listening
Well-known member
- Joined
- Jul 22, 2012
- Messages
- 81
Sleeper said:
Speaking of this, first saw it when recapping a Revox A77. Is it worth applying to home etched boards with bare copper traces?
Sleeper
Well-known member
I tin all my boards, and most all of my vintage boards, electrodyne, api, electro harmonix etc. are tinned.
Despite PRRs always practical advice, My uncoated copper boards do get a bit oxidized if I leave it sitting for a few weeks before I solder. I don't like the look of it.
Tinning is super easy. just warm the solution and drop in the boards. The solution is reusable too, if it's stored in a clean container. It doesn't seem like a huge waste and I like my boards to look spiffy.
I use Tinnit. Just ignore the advice on the package to use one time only and then toss it.
And do dispose of it properly please. That's easy in Los Angeles where we have a city run hazardous and e-waste drop-off site. YMMV
Despite PRRs always practical advice, My uncoated copper boards do get a bit oxidized if I leave it sitting for a few weeks before I solder. I don't like the look of it.
Tinning is super easy. just warm the solution and drop in the boards. The solution is reusable too, if it's stored in a clean container. It doesn't seem like a huge waste and I like my boards to look spiffy.
I use Tinnit. Just ignore the advice on the package to use one time only and then toss it.
And do dispose of it properly please. That's easy in Los Angeles where we have a city run hazardous and e-waste drop-off site. YMMV
