If you want a fairly professional PCBⁱ prototype then this method is definitely worth a try! You can purchase all of the items you require from www.electronicprojectsonline.co.uk<

You will need:

• A laser printer (I used a Brother HL-1430)
• Some Photo ink-jet paper (I know... Photo ink-jet paper and a laser printer?)
• An iron - (preferably an old one, although it wont get dirty!)
• Some brown wrapping paper
• Some copper clad board (FR4 is probably the best as it seems to accept the heat from the iron better)
• Suitable etching chemicals & protective gear
• Some nail varnish remover (of all things!)
• You may also need a PCB touch up pen (etch resist pen)

Step 1 Create your Etch Mask using a laser printer.

You need to firstly make your PCB etch mask using whichever program you are used to, you can even use publisher, word or paint if you can work out where the tracks and components go!

I made the following using publisher it is a guitar fuzz PCB fairly simple to do but you just need to make sure the component lead pitches are correct, especially for Integrated circuits and less flexible components such as switches.

This is a very small PCB (50 X 23 mm approximately) so if you want to print several off at once you could fit about 8 on a small 160x100 copper clad board. Your print out will be quite fragile, be careful not to disturb it too much as any cracks in the lines here could mean touching up later!

You then print it onto the photo paper. When you print laser toner onto photo paper it doesn't cure like it does on standard paper. This means that with some heat you can get the toner to fuse to a different material.

Once you have your print out the next step is to transfer this onto the copper clad board.

Step 2 Transfer your etch mask to the Copper clad board

Heat the iron up to its highest temperature.

Align the printout to your copper clad board with the printed side to the copper.

cut or tear a piece of brown paper a little larger than the copper clad board and place this carefully over the board and the photo paper.

You don't need steam for the next part, in fact it is best that it is dry at this stage, you could injure yourself!

Making sure that your photo paper is sandwiched  correctly between the brown paper and copper clad board and aligned properly.

Press the iron onto the brown paper, and use as much force as you can and hold it there for around 3 min, the longer the better really. If you do not apply enough pressure and the temperature is not hot enough then your PCB will fail at this point.

Once you are certain that your toner has fused to the copper (it may take some practice to be absolutely certain) you can then let it cool for a while before picking it up.

You can now peel the photo paper off the copper clad board, it may be melted to it, if so soak it in warm soapy water to release it.

You should now have a mask that will be resistant to Ferric Chloride and other etching chemicals.

You will need to inspect the board before etching as some areas may need touching up. I used a dedicated PCB touch up pen, which resists etching chemicals.

When you are sure that your PCB track etch mask is flawless, proceed to etch using your usual method. Be sure to wear protective clothing and be very careful with the corrosive chemicals.

Step 3 Clean off the Mask, inspect and finish your PCB

When the excess copper has been etched away, you should thoroughly rinse your PCB (remember that Ferric Chloride is toxic and corrosive and should NOT be put down your drain!)

Dry off your PCB and use some nail varnish remover and a paper towel to remove the laser toner and any etch resist ink from the finished PCB.

There you have it... You can now drill the holes, and coat the tracks with tin if you wish, this will make things easier when you come to solder.

I hope this has been informative!