Creating Printed Circuit Boards (PCBs)
I have created this section to show how I have created the boards for my projects. I have to say it was a lot easier than I thought before I started.
(I will add some pictures to this page when I next create a board)
||To cut the copper boards to shape
||To draw on the copper to correct problems with the transfer. Needs to be resistant to ferric chloride. (Maplin's # HX02C, should be able to find this type of pen in many other shops )
||Hold the etching solution, to immerse the copper board. (Maplin's # CH38R)
||Ferric chloride solution 250ml (Maplin's # WF10L)
|Press 'n Peel Transfer Set
||To transfer the image onto the copper board (Maplin;s # AB15R, check out Ebay for cheaper deals)
||One that you iron you clothes with
||Unless you intend to make double sided boards, you only need to get the boards with copper on one side.
|Scotch brite or fine steel wool
||To clean the copper on the boards
First of all I created the schematic in the Eagle Layout Editor by Cadsoft, then using the same software I created the PCB. Make sure that you do not make the copper tracks to thin as these are harder to solder.
The image above shows outlines (in white) of the components. You need to switch off this layer in the software so that only the tracks remain.
Next load your laser printer (it will not work with inkjets) with the transfer film making sure that the printer will print out on the dull side (emulsion) of the transfer film. Print out from the Eagle software. You now have an image of the tracks on the film.
Cut the copper board using the hacksaw to the required shape and prepare the copper board by cleaning with a fine grade steel wool or scotch brite. This should leave the copper nice and shiny.
Place the film (printed side against the copper) onto the cleaned copper board, then place a piece of plain paper over the top. Next set the iron to cotton temperature (275-325 degrees F, this will vary so you might have experiment) and also switch off the steam if it is a steam iron.
Gently iron the image onto the copper board, try to resist pulling away the film to have a look. Keep ironing until the image of tracks turns dark almost black. I found that you need to pay special attention to the edges of the board.
Next the important bit, let it cool for a least 20 minutes. Do not be tempted to peel away to have a look. Once it has cooled slowly peel away the film from the copper board, this should have left the glossy dark blue tracks on the copper board. If there are a few bits missing, don't worry you can draw these in by hand with the permanent marker. It is also important that you don't handle the copper surfaces as grease from your hands could stop the etching of the copper. Handle the board from the edges only.
Next lay the copper board in the tray and pour over the etching solution. Hold the tray at one end and agitate the solution in a rocking motion over the copper board. Watch as the etching solution slowly eats away at the copper. It will be pretty apparent when it's done. It should take between 10-20 minutes dependent on temperature, solution concentration and solution use (the more it is used, the slower it gets). Rinse the board under running water, examine the board. If it looks like it needs more etching then just place the board back in the tray and immerse it for longer.
A word of warning about etching solution, it will stain your hands and is an irritant. So it is important to wear gloves. Also it is poisonous, so don't do this in your kitchen sink!
Your board should now ready!
You can leave the film on the tracks until you are ready to drill and solder. It will stop the oxidization of the copper. Once you are ready, you can clean the film off the tracks with fine steel wool or scotch brite until the copper is shiny.
Have a go it's easy!