How to make my own PCBs?

[JohnR]

While thinking about fitting some lights to some of my older locos, I got to wondering about creating my own PCB, with LEDs mounted on them in order to make fitting etc easier.

 

But where would I start? I can draw out the circuit that I would need, but is there anyone that can manufacture and assemble it? Has anyone done this themselves and have someone they would recommend?

[Hunslet]

Hi John.

I used to make prototype PCBs many years ago before I retired.

The method is to layout the circuit using etch-resist pens or etch resist transfers ( applied like letraset )

on the copper coated board and then etch away the copper which is exposed using Ferric Chloride solution ( nasty stuff ).

The holes for the components can then be drilled using dremel or pin chuck, the board cleaned up to remove the etch resist with solvent or abrasive rubber.

Kits are available for the beginner ,here is one I found.

https://cpc.farnell.com/kemo-electronic/a200/circuit-board-etching-kit/dp/PC01609?mckv=sSd8wYVYM_dc|pcrid|224692157647|kword||match||plid||slid||product|PC01609|pgrid|47391249736|ptaid|pla-819046969435|&CMP=KNC-GUK-CPC-SHOPPING&s_kwcid=AL!5616!3!224692157647!!!network}!819046969435!&gclid=EAIaIQobChMIt8u2hqSu8AIVk2DmCh3kGQmpEAQYASABEgJnVPD_BwE

Hope this helps. 

[H2O]

8 hours ago, JohnR said:

While thinking about fitting some lights to some of my older locos, I got to wondering about creating my own PCB, with LEDs mounted on them in order to make fitting etc easier.

 

But where would I start? I can draw out the circuit that I would need, but is there anyone that can manufacture and assemble it? Has anyone done this themselves and have someone they would recommend?

Two thoughts: Use narrow strips of  0.1" strip board and mount LEDs across 2 tracks.  Second you can get some quite cheap PCBs made on-line.  If doing say 10 sets they could be economical. You may be limited by the shape that can be made if you want very long and thin.

 

I've not done PCBs with mounted components, you may need larger quantities to make it economical to do a run.  However surface mount components are tricky to do yourself.

 

I'm unsure if making PCBs at home is worth it as double sided through hole plated are so cheap, even in small quantities.

Edited May 3, 2021 by H2O
Spotted for locos, not coaches.

[didcot]

I experimented with etching about 8 years ago. Mine was more for brass nameplates, but the process is the same. You need to make a mask of you pcb and print it onto clear acetate film. Not easy with a home ink jet printer. I did mine on the work laser printer. You then need a photo sensitive medium. I had a spray from RS. Clean the board, spray on the photosensitive medium and let it dry in a dark room. Next place your pcb mask onto the piece and expose to UV light. I bought a small UV box, but some have had results with UV nail light boxes. You then need a developer to remove the unexposed medium. Once that's done a solution of Ferric Chloride is used to etch away the unprotected metal.

I had trouble with the photosensitive medium coming away during the etching process. The Ferric Chloride works better when warm. It's nasty and can only dissolve so much metal until it becomes inactive.

You can get an iron on medium, I forget what it's called, but the results weren't great.

The best results I've had was using sticky back vinyl and a Cricut cutter to cut out the template. Stick that on the brass and peel away the unwanted bits to reveal your design. I then use a copper sulphate solution and a power supply to etch away the material. 100% results every time. I've done 4mm scale running in boards and 5" gauge loco plates.

As others have said if it's simple use some veroboard.

Hope that helps.

[ikcdab]

You don't need PCBs. Just use ordinary veroboard for such simple circuits. 

Its really cheap to buy from eBay and dead easy to use.

[Vecchio]

If you just do one pcb I suggest to use an etch resistant felt tip. There are also rub on transfers for prototyping, very useful if it comes to IC sockets or connector sockets, as you will get the spaces between holes right. Look for SENO or Letraset PCB transfers. They also make transfers for straight lines in different thicknesses. Very useful as it gets much neater than with a felt tip.

 

Before going on the copper surface it is important to have that as clean and fat free as possible. A rub with kitchen abrasive powder like VIM will do the trick. Then try not to touch it much with your fingers when you do the transfers or the felt tip lines.

 

Having your PCB in the etch bath keep moving it with a wooden tool like a party stick and check the progress. If left too long in the liquid it will go under the transfers.

Just one - not too good - example

20170304_202045

in the end it does the job.

20170304_203159

one made with SENO transfers

20170304_192345

and ready for using.

20170304_200325

Where did they go into? old Lima locos for a light upgrade

20170305_162735

Edited May 5, 2021 by Vecchio
spelling...

[Steven B]

If you can draw the circuit then you're well on your way.

Find yourself some PCB CAD software such as Autodesk Eagle or DesignSpark and convert your design into CAD.

Once you've drawn up the circuit you should be a few clicks away from a designed PCB.

 

Personally I wouldn't bother with DIY etching of PCBs. Ferric Chloride isn't a nice chemical to work with. Much easier to send your designs off to one of the many Chinese based PCB fabricators and have boards returned within a couple of weeks - for what you have planned the postage will probably cost more than the circuit boards.

 

Then it's a matter of populating the boards - if you can solder a track feed you can populate the PCB yourself.

 

I'd suggest joining MERG or finding some of the electronics hobbyist sites where you'll be able to get recommendations on both PCB software and manufacturers.

 

Steven B.