Hi everyone! :mrgreen:
Just a quick-ish tutorial/information sheet explaining how you can make single/double sided PCBs in the comfort of your own home. ^___^
Most of you guys probably already know this stuff but if anyone needs it, itâll be right here. :mrgreen:
Um ⊠I guess Iâll post the relevant links as I go along so itâll make more sense âŠ
Okay, here I go. :mrgreen:
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Start off by designing your circuit on some sort of CAD software - normally itâll kinda depend on the complexity of the circuit you wish to design. I suppose if you want to go detailed, then youâd be better off using something like Eagle (although from what Iâve read, it can be difficult to use if you havenât learnt how to do the basics, etc.). Since my designs are pretty basic, I just use PCB Wizard - it can do all the basic things (autoroute, etc.) and isnât much of a hassle to use but there are quite a few free ones out there which do the exact same stuff (and more).
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Once thatâs all done and dusted, youâve got to find someway to transfer the circuit artwork to a sheet of Acetate. Now there are a few different kinds of them out there for different kinds of printers so you just need to find the right one and then print the artwork out on it. If you canât find a type of acetate that works with your printer, you can go for the method that I use - print out the design onto normal paper and then take it to a Printing shop/Internet Cafe/Workplace or wherever they may have a printer that goes with an acetate sheet and then photocopy the design onto the sheet. I went to a printing shop and since I had the acetate sheet and only needed one copy, the guy there did it for free. Lucky me.
http://www.technick.net/images/guide_pcb/guide_pcb_artwork.jpg
An example of what it should look like.
- So by now youâll have your design on an acetate sheet and youâll be wanting to transfer it onto a Photo-Resist Board. Now using this method, you can do double-sided circuits to so make sure you get the right board. ^___^
Now, the way the artwork will be transferred onto photo-resist board will be through a UV light box. Now some can get very expensive but Iâm sure there are some second hand ones out there. Looking at the one that I used, it just seemed to be 2 UV tubes and a timer so Iâm guessing it could be possible to make your own UV light box since all youâd need are some UV tubes, but I still have yet to try this.
http://webspace.webring.com/people/xk/kingimuk/images/pcb_exp.jpg
The UV light box I used was very similar to this one. You can see the UV light tubes under a glass sheet.
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Anyway, assuming youâve gotten past the UV light box situation, you can move onto transferring the design. You place the acetate sheet (with the artwork on it) face-up so that it looks just like it did on the computer - itâs easy to forget if itâs backwards when all you see are tracks so it can be helpful to add a little bit of text in the corner; perhaps your initials or something - just so long as you can tell which face is up.
You then peel back the protective film and then place the newly exposed side of the board onto the artwork - make sure you do this fairly quickly as the exposed side could begin to slowly develop with the natural UV light. If you happen to be making a double sided board, then youâll want to repeat this step by turning the board over after finishing step 5. -
Turn on the UV light box/tubes and leave the board for approximately 5-7 minutes - this time really depends on the UV light box/tube itself so itâs highly recommended that you do a small test piece before you move onto your final design.
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Now that the design has been transferred onto your photo-resist board, you can place the board into some Developing Solution - this will bring out the artwork on the board. Youâll have to read the instructions provided with the developing solution which tells you about the ratio of water to powder so itâs neither too strong or too weak. I once made the mistake of mixing it without measuring the amount and ended up making a super concentrated solution that totally wiped the design off the board in about 3 seconds.
Also, it would be best to wear gloves for the next few stages because the solutions can become irritant/corrosive.
So once youâve made the solution, place the board inside and gently rock the board back and forth until you see the design starting to appear - once youâre satisfied the design has come out fully, take the board out and wash gently with warm water. -
Dry the board off and then place the board into some Etching Solution. I tend to use Ferric Chloride but there are some others out there that you can check out. Again, read the instructions carefully because if itâs too strong, itâll etch away the tracks along with the excess copper. Whilst etching, youâll see that the excess copper is being etched away and youâre being left with the tracks. Once youâre satisfied that the excess copper has been removed, wash the board gently in warm water and then dry it off.
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Congrats! You now have completed the production of your own PCB! :mrgreen:
There is one thing you need to do before you can move onto drilling the holes and soldering, etc. and that is to remove the protective layer from the tracks. Youâll see that the tracks arenât copper yet - they seem to have some kind of gold coloured layer on them (see photo below).
You can just use some sort of wire wool or one of those sponges used for washing dishes (preferred) to ârubâ off the protective layer leaving you with the copper. You can now if you want, apply some sort of treatment to the tracks so that they donât rust but before you do that, it would be best to wipe off all the âdustâ from when you rubbed off the protective layer (see photo below) - I normally use a wet wipe (like the ones you get with your take aways) which works quite well. ^^
Take some time to inspect the tracks with a magnifying glass for small breaks. If you do happen to find some, then a bit of solder over the tracks will solve that problem. All youâve got to do now is drill the holes for the components and away you go - Happy Soldering! ^^ -
Just a few things to note when going through this process:
- Itâs always good to have the Developing and Etching Solutions ready before you start so you donât waste time getting them ready when you start.
- When designing the board, make sure that you make the tracks fairly thick as thinner tracks (perhaps for surface mount components) might be etched off. Itâs not definite but can happen.
- As mentioned earlier; it would be best to go through the whole process with a test piece first so you can fine tune the various aspects of the process to achieve the best results.
Hope this helps people out! :mrgreen:
Oh, and thanks for taking the time to read this - it canât have been easy.
AKdaBAOUS