2 - Making the PCB

Submitted by Webbot on August 29, 2008 - 4:19pm.

Trying to make your own PCBs is expensive!! If you choose to use a standard matrix board as per Admins tutorial then skip through this section if you want.

 

Although I don’t want to do a tutorial on this subject then here are some thoughts.

 

You can either do this using ‘ultra-violet light’ or by ‘copper etching’.

The first method involves printing your (Eagle) board layout onto a transparent film, then laying it onto some photosensitive copper board and then ‘cooking’ it in an ultra-violet light oven. The expense comes from having to buy ‘photosensitive copper board’ for each PCB as well as the one off cost of the ultra violet box (which has to be enclosed as U.V. light can give you an instant tan/melanoma).

 

The second method involves transferring your (Eagle) board layout onto the surface of a copper board and then putting it into an acid bath to ‘eat away’ all the exposed copper. This tends to be cheaper but means playing with harmful/dangerous chemicals. Wear gloves – and don’t splash your clothes – (the voice of experience!).

 

Lots of web sites sell ‘beginner’ kits of both sorts – but both methods tend to require the use of a Laser printer NOT an Inkjet. Google for making PCBs and you may find alternatives.

 

I opted for the second option as its cheaper to get going. I used a system called Press’n’Peel. Google for it. The basic idea is you Laser print your PCB design onto the Press’n’Peel and then iron it onto your circuit board. You then place the board into acid/oxidant that eats away all the un-wanted copper. There’s a great video on You tube http://www.youtube.com/watch?v=Q6WJqjVleG0 with perhaps the worlds most ‘I am not interested voice over’! Also – check out his hands to see what acid can do to your skin!

 

One word of warning:- having spent £50 on a Brother Laser Printer I experienced some problems. Looking at the Press’n’Peel home website it transpired they say there are problems with Brother printers (must be the ink I guess?). So eBay for a cheap ‘non-Brother’ Laser printer.

 

Here are a few other tips:

  1. I prefer to drill the holes in the board before etching. If you do it afterwards then some of the copper pads may come off the board.
  2. If you haven’t got a drill press then a cheap alternative is to use a small hand drill like this one available from Games Workshop. But it takes quite a while.