Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Making PCBs the easy way.

Status
Not open for further replies.

amazing1000

New Member
Making PCBs the easy way.
By foxdeltaone AKA amazing1000.



This is what is needed to make printed circuits boards:

There are a few ways to do this, but we will only give instructions to make one off boards as this is what the novice will need.

If you wish to make more than the odd board then it can cost you quite a bit of money by either making them yourself(and buying all the necessary equipment) or designing the board and sending off the design to a PCB manufacturer to make them for you.

The stuff you need:

1) PCB Design software which for our purpose can be something as simple as PCB Wizard Pro which is available quite cheaply (compared to some of the big guns in this field).
2) A printer capable of good definition printing, preferably a laser printer (these are fairly cheap now).
3) Some sort of Ultra Violet light source to develop the board (If using photo sensitive board (I converted an old scanner by ripping the insides out and putting in 2 15 watt U.V. tubes).
4) Some acetate to print the design onto. (Not needed if you use the iron on or rub down types of transfer).
5) Some photo sensitive board if using the printer method. Copper clad board to iron or rub the transfer onto ( if not using the printer method) Fibre Glass board is preferred though cheaper boards such as Photo board II can be used but not recommended for professional use.
6) Some photo resist Developing fluid(or powder, Please use the Sodium-Hydroxide free (if using photo sensitive board))
7) Some Etchant either Ferric Chloride, or the newest clear PCB Etchant.(the latter is preferred
8) A container for the Developer(if Needed)
9) A container for the etchant (preferably with a heating device and pump (fish tank heater and a pump will do)).The heater and pump will improve the etching time though are not essential.
10) A container with some water in it (to rinse the boards at the various stages), and some rubber gloves and a face mask for your safety.
11) You will also need a small powered drill with some bits in sizes 1mm and 0.7mm, plus any larger for mounting holes etc. Fibre glass will dull bits in a very short time as it is very abrasive.
12) Don’t forget that you are working with chemicals, so make sure you dispose of them correctly when used up as they don’t last long.
(Protect the environment please !)

Ok so we have our kit , let’s get started.


To make a board does take some degree of skill but this can be quickly acquired.


Making PCBs using the transfer method

To make the simplest of PCBs we will first start with the rub down or iron on transfers.

I will not go into using the PCB design software as you maybe using something different and you should be able to sort that out yourself, but needless to say you must check your design over and over again to make sure it is correct before etching it, and make sure if using the photographic method that you place the positive the correct way round (I place some txt on the positive to help with this).

Ok you have designed your PCB and now want to transfer it to the board.
You can use rub down transfers which come in most variants such as IC pads, lines etc, but these are now fairly hard to find and can be costly or you can now buy some special iron on transfer sheets from such places as Maplins, which although expensive can make a quite respectable PCB.

If using these sheets you will need to print your design onto the sheet (don’t waste it if only doing a small board cut the size of board you need before ironing the transfer onto it).

After you have printed this you will need to make sure any copper clad board is spotlessly clean and shiny (keep your fingers off it this will leave grease marks etc) it is better to use clean gloves.
Place the transfer over the clean board ,with some clean paper over the top to prevent the iron sticking and iron it on following the maker’s instructions and when it is complete peel the transfer off and still keeping your fingers off place it straight into the Etchant.(MAKE SURE THE ORIENTATION IS CORRECT).
This will then etch until all the copper except the covered are has disappeared.
Your board is now complete and ready for drilling, after which if you didn’t make a mistake with the orientation you can now place your components and solder them into place taking care not to overheat and IC or Transistors etc.

You should now have a working board if the design and build was good.
These transfers are available from Maplins but are quite expensive!












Making PCBs using the (better) Photographic method


With this method it will require a little more money (to make or buy a UV light source and the cost of photo sensitive board (you can make your own board by buying the spray but take it from me it is a pain in the rectum and time consuming)), you will also need developing fluid and of course the etchant.


**broken link removed**
Above is a picture of a positive after it has been designed and printed using a
laser printer on some acetate sheet.

Below is a picture of my converted scanner with timer switches on front and showing some positives.

**broken link removed**



Ok so you have the positive made and also your UV light source.

Place the positive onto the glass (making sure it is the correct way up so that the print will come out on the board with any component orientation correct.), now cut the photo sensitive board to the correct size (a tip here is to leave about ¼ of an inch more on at least one side so that you can handle it without getting grease marks on the part of the board you need.)
Another tip is to apply a little weight on the scanner(box) lid so as to keep the board in full contact with the positive image which should then give a nice clean image.

Timers to make this UV light source can be bought from Maplins etc,(as can UV light boxes complete.) you only need it to cover 0 to 12 mins and you will nearly always use 6 or 8 mins to apply the image to the board.
**broken link removed**


This is the PCB Guillotine I use (which is rather expensive) but you can use a saw or whatever you like to cut the board but fiberglass is very abrasive and will blunt a saw or drill very quickly.

Now peel the protective black plastic from the board (make sure you don’t touch the surface) and lay it over the positive making sure it is completely covered.

Now if you built or bought a UV light source then set this to around 6 - 8 minutes (this should be long enough though this can depend on thickness of the tracks).
Switch on and let it complete for the allotted time(better to have a timer built in or external to switch it off)

Now you should have has some developing fluid mixed (as per manufacturers instructions) into a container and also a container with water in it.



**broken link removed**


After the positive has been transferred to the board, place the board into the developing fluid, this should only take a short time (mixed correctly as per instructions) when you will see the image appear on the board. Make sure it is a nice clear image then lift it out and place it into the container holding the water and give it a wash but still taking care not to touch the printed area.

The next stage is to place it into the etchant (this should be mixed as per suppliers instructions, too much and your circuit will disappear, too little and you will wait forever but better too little than too much) and as I said I prefer the clear etchant above ferric chloride but either way you should always take care with any chemicals and wear protective gloves, mask and goggles.



This is a picture of the tank I use, but you can use a simple container such as the type you used for your water holder (by the way these are available in your local £ shop).
A heater (fish tank type will do) and a pump (again fish tank type will do) will help etch the board quicker, but remember this etchant is corrosive to metal

**broken link removed**



Now you keep checking the board until all the copper has been etched away leaving just the tracks you wanted.
Lift it out of the etchant and place it in the water, give it a good wash and then dry it.




Check all the tracks to make sure there are no breaks or shorts and if ok you have made your PCB which now only needs to be drilled (using the correct size drill bit, I use 0.7mm for IC pins and 1mm for connector pins such as D type plugs/sockets and then fit the components, solder them in, you don’t need to clean the covering over the tracks as this protects the tracks and it will accept the solder ok .
Make sure you don’t make any shorts with your soldering and be sure you make good joints by flowing the solder correctly to all the connections.

**broken link removed**
These small drills can break very easily so have spares Do a search on Ebay and you will get them very cheap, at the local electronics shop a pack of drills will cost you around £10.00, whereas on Ebay you will get them for around £2.00)

Now you should have your first working board.
Congratulations!!!!
 
Last edited:

picbits

Well-Known Member
I have the same Dremel + Stand - the stand is a nightmare if you have any play in it whatsoever. I've tightened everything on mine up as much as I can before it starts sticking. I also find it doesn't drill "square" - the bit comes down at a slight angle.

Saying that though - I must have drilled a couple of hundred holes over the past couple of days and only broke one drill bit (which was due to me not holding the PCB firmly enough).
 

amazing1000

New Member
My stand is fine, must have got a good one lol.
I have broken a few bits some as you say carelessness, but others just become blunt because of the glass fibre boards.
 

picbits

Well-Known Member
I was lucky to spot a box of 50 TC PCB drill bits at Axminster - they were resharpened and imported from the USA. At around £15 a box of 50 I got a mixture of 0.2 to 6mm bits.

I bought 4 boxes of them and between them I've got just about every size I could hope for lol.
 

amazing1000

New Member
Yes good firm I have used them for lots of tools over the years and can't fault them.
I have around 20 of those packs, got em cheap on flebay lol.
 

shimniok

Member
Looks like a good writeup!

I got a grab bag (box really) of the bits from HarborFreight. Had enough of the right size to make it worth it. I use a similar drill/stand. It's actually the craftsman rotary and stand and while there's some play I've only rarely had a problem with bits breaking. Maybe 2 in a hundred holes or more, over dozens of boards. I just move the bit very close to the board, punch it through quickly and pull it back up fast. I dunno if it's technique or equipment or what.

I use the toner transfer method with magazine paper. That's all about technique when using a clothes iron :) Amount of pressure, length of ironing, amount of material between iron and pcb... all seem to matter. Although I found I have better luck with the thicker magazine pages of Scientific American versus standard thinner mag paper. So far I'm able to reliably do 16 mil traces and TSSOPs is about as tight a pitch as I can pull off (breakout boards for all else!). I use toner transfer for 'silkscreen' too and spray with clear acrylic or some such. They come out looking pretty nice.
 

3v0

Coop Build Coordinator
Forum Supporter
is a good tutorial on high end toner transfer at Ultrakeet. With this system resolution is very good. But like the UV high end method it requires an investment in equipment.

coreFuncPOC.jpg
 

picbits

Well-Known Member
sorry, i mean the tools for pcb fab

So what is the alternative for home made PCBs ?

I run a small electronic business and build to order. I make small batches of board which are often customised to a specific requirement by my customer. If I outsourced the boards to a PCB fabrication house in the UK I could have the boards back in 3-5 days but the boards would cost me 10 times as much to make. If I outsourced to China it could be anything from 5 to 14 days but would be slightly cheaper.

I can get a design from my computer onto an fully etched PCB using methods similar to the abve in around an hour.

What tools would you use for PCB fab ?
 
Status
Not open for further replies.

Latest threads

Top