Copper clad board

[boylesg]

I had some success with copper plating this weekend.

I got an used matrix board and painted the reverse side with a graphite paint I made. I mixed White nite kill rust clear with some lubricating graphite to a creamy texture and then painted the fibreglass surface. I gave it a very rough sand and then electroplated in copper suulfate solution with a little sulfuric acid using a car battery re-charger overnight.

It starts off plating very slowly but speeds up as the copper area grows.

I didn't bother completing it was just to see if it would stick and it has. The copper surface pretty rough but if you built up enough of a layer you could sand it back and make it smooth.



As you can see I soldered on to it and it did not delaminate. The rough copper surface made it a little hard to get the solder to take but that would be solved by sanding the copper back.

Then I tried coating 3mm MDF in the same white night epoxy paint but even 3-4 coats is not water proof. The MDF is to dense, absorbs the epoxy paint like a giant sponge and it would require MANY coats - too much hassle. Perhaps the fact that I did not leave it to dry overnight first compounded the problem

Next I will instead try embedding 1.5mm thick balsa wood in white nite fibre glass resin and see if I can electroplate that. Fibre glass resin should render the balsa wood water proof. The fibreglass resin should do a better job at waterproofing and the basla wood is no where near as dense as MDF.

Those matrix board are a pain because the copper ringlets delaminate easily of you put the soldering iron on them for too long or on more than once occasion. And the copper clad boards for etching are rather expensive and would probably suffer the same problem as the matrix board.

It is no good for you profssionals but perfectly doable for amateurs like me.

 

[boylesg]

Importantly, once the copper traces are etched, you can use metho or acetone to dissolve off the exposed graphite paint to prevent any shorts between the copper traces.

 

[ArticCynda]

Impressive results, well done!

It is no good for you profssionals [sic] but perfectly doable for amateurs like me.

Doable it certainly is, the question is rather whether it's worth the effort and health risks doing it at home while there are plenty of Chinese PCB fabs who can do it probably cheaper and deliver professional quality PCBs.

 

[boylesg]

Impressive results, well done!

Doable it certainly is, the question is rather whether it's worth the effort and health risks doing it at home while there are plenty of Chinese PCB fabs who can do it probably cheaper and deliver professional quality PCBs.

Health risk....I am not planning on making them 24/7....more like once in a while when I have a special project in mind that would otherwise require multiple matrix boards.

For really simple circuits I would stick with the inexpensive matrix boards.

And there is the satisfaction of knowing I can make my own if I want to.

It is just another challenge to overcome.

 

[boylesg]

Another thing that is quite attractive to me about doing this is that I could fairly easily re-use the boards.

Just etch off all the tracks and solder, clean the board and electroplate new copper on to it.

Re-use and re-cycle.

 

[ArticCynda]

Another thing that is quite attractive to me about doing this is that I could fairly easily re-use the boards.

Just etch off all the tracks and solder, clean the board and electroplate new copper on to it.

Re-use and re-cycle.

Nurdrage made a few good video tutorials last month on recycling etchant and copper, they're available on YouTube.

 

[boylesg]

This is my first serious attempt at making a copper clad board.

I made the board from fibre glass mat impregnated with resin and then sandwiched between to sheets of MDF with Al foil to stop the resin sticking - the Al foil peels off the cured resin quite easily.

The problem is that it is quite hard to get the board perfectly flat even after sanding it. There always seem to be some divots that I can't seem to get out. And it is quite a bit of mucking around.

I have made some more boards out of thin masonite and smeared those with the same resin. This method of producing suitable boards would be much easier and quicker. And you can always find thin masonite or MDF on the backs of dumped furniture (re-use and re-cycle). I tried coating some scapr MDF with the resin and left it sitting in water for a couple of days - there was no sign of the MDF swelling due to water penetration.

Once you have your boards prepared you then need to make graphite paint. I got some graphite powder and mixed it it clear epoxy paint to a creamy texture.

Then I used a small roller to coat the boards. I did one coat but, after this current experiment, I would recommend at least two coats to make sure the board is thickly coated.

Then the next important step is to give the dried graphite pains a sand with fine emery paper to fully expose the graphite particles for maximum conductivity of the surface.

Then I immersed the board in copper sulfate solution along with some scrap copper pipe. The positive terminal of a battery charger was connected to the pipe and the negative terminal to the board.

It is important to include a 56R or so resistor to limit the current in the circuit to tens of mA.

If you don't the high current (3A or more) will prevent the copper depositing evenly over the surface of the board.

With this board, some divots around the edge prevented the emery paper reaching the surface of the graphite coating resulting in poor conductivity and poor deposition of copper.
I trimmed the board with an angle grinder however than caused a bit of de-lamination of the copper as you can see.

It will be far easier to get the smooth surface of the masonite totally flat and therefore the copper should deposit in a completely even surface.

 

[boylesg]

DIY copper clad board

This is a bit of an update on my efforts to figure out an easy and inexpensive way to make my own copper class boards.

I have found that using fibre glass resin smeared over sheets of thin MDF or masonite works effectively at water proofing the wood for prolonged immersion in aqueous solutions.

However it is messy to use and stinks of styrene as you can imagine. And it is relatively expensive.

So I have been searching for another more convenient way to do the same job.And shellac dissolved in metho seems to do the job as well and both are relatively cheap. This amount of shellac and metho could water proof a great many circuit board substrates.


What I did was to dissolved shellac in methylated spirits until the mixture has the consistency of a can of regular varnish from the paint isle of your local hardware store.

Then soak your sheets of MDF or masonite in this for several hours.

Pull them out and drain them and allow them to thoroughly dry out. Ethanol is very volatile so this does not take long, especially if you put them in front of a heater.

Once they are dry you can sand them smooth with fine sand paper.

Then they seem to be totally water proof.

I tried this with piece of MDF that was broken in half rather than sawn. And I only soaked in shellac it for a few minutes.

After drying it I left the broken end standing in a jug of water overnight and there was no sign of water ingress into the MDF.

Here is that test strip:


Here is a bigger test that I am trying:


I will soak these in water after they are dry and post my results.

Importantly you can also add your graphite to the above mixture and use that as your conductive paint. I used it on sheet of masonite that I water proofed with fibreglass resin and it is currently plating with copper slowly but surely.