Want to make PCB at home via UV method, what equipment do I need

[matrixofdynamism]

I want to do a project at home and for that I shall need to make some PCB. I think that the UV method is best and gives most consistent results. However, I am not sure what is all the equipment I need for that and its cost and where to get it from in UK. Any advice?

[DerekG]

That's great if you just want to feel the satisfaction of "having done it yourself".

You will have to place a wire (use the ends of through hole resistors so you don't burn your fingers) through every via & solder them on both sides.

If you are just looking to save money, then visit www.pcbshopper.com for a cheap quote. You will likely end up with your boards completed professionally at a much lower price than buying all the bits required to make them yourself.

[M4trix]

Hi,

If you still want to do it at home then I suggest a UK company, Mega Electronics. They have all stuff you need. Here is a three part video (tutorial) about the basic things you'll need.

http://www.megauk.com/
http://www.megauk.com/pages/general-faq-137.htm

[matrixofdynamism]

I intend to do it at home for 2 reasons, (1) it shall be quicker and (2) it shall be cheaper. At least this is my expectation. It is not uncommon to make mistakes with our circuit board and we might want to make several as we progress in our project. Waiting for circuit boards thus may take many many days, or few to several weeks. This is time wasted is it not?

I have several questions regarding this UV method. As far as I understand, I shall need:
(1) copper clad board with photoresist
(2) transparent sheets to print the circuit board layout onto, these may be rather expensive. Use scanner printer set to 600dpi, the resolution is important to get finer pitch pads right in print.
(3) UV light source, I am not sure if mere sunlight will be enought and what happens if we expose to UV source for too long. I get the time as being 8-15 minutes.
(4) developer solution to etch away the photo resist that was exposed to the UV light, I wonder what happens if we leave it in the developer for too long and how do we know that it is enough time.
(5) Etchent, usually Ferric Chloride. One reason why I am still undecided about going for homemade PCBs, but if it has to be done this way then it has to be done. No point in procastinating. I am not sure what concentration of this is needed and what happens if we leave the board in for too long how do we know that it is enough time.
(6) Acetone, also known as nail polish remover. This shall be used to remove whatever stuff is left on the board to reveal the shiny copper underneath.
(7) Drill machine with atleast 2 different size bits. Well perhaps the hand held drill is not best for this purpose, since usually I see people using a vertical drill.
( 8 ) Etchent neutralizer
(9) a tray to do the etching another tray to do the developing, perhaps a single tray can be used for both?
(10) Most important, safety equipment. This is gloves, eye protection at the minimum. It is important to use etchent in a well ventilated space as it releases fumes. No stains are acceptable from the etchent anywhere, not on clothes, not on any surface. Ethchent can damage sink pipes if put into sink. It must be neutralized before being thrown away

Yes so that really is a lot of stuff. Do you really think that placing an order for the PCB is a much superior thing to do? I do find that Maplin in UK has a lot of these things, but I have not bought any of them yet. I am still thinking which route to take and then stick with it for all my boards, or atleast all my simple boards. First I also considered the method where we use a laser printer to print onto glossy paper and then transfer the tonner onto a copper clade board using a iron. But I found that people do not get very consistant results with this method and thus dropped it. An etchent solution is always required unless we are using a milling machine.

[AndreasF]

Mike (from "...'s Electric Stuff") has a very good page on what's needed. It's a few year old, I think, so a few specifics may be out of  date.

http://www.electricstuff.co.uk/pcbs.html

[matrixofdynamism]

@Deathwish, how can you be using highly corrosive liquids and not be using gloves?

[M4trix]

@Deathwish, how can you be using highly corrosive liquids and not be using gloves?

You want to make PCB's without having yellow fingertips? 

[Fred27]

Some tips from me:

• Cheap UV nail lamps on eBay are fine for UV exposure.
• Use a metasilicate based etch resist developer rather than the other sort (sodium hydroxide?).
• I got good results with a Canon MG5250 inkjet set to T-shirt mode. Inkjets seem to work better than lasers.
• Ferric Chloride may not be the nicest chemical, but HCl/H₂O₂ is nastier IMO.
• Disposable gloves should be all the protection you need.
• Use quality presensitised boards (e.g. Bungard). Maplin stuff is a bit rubbish.
• You can get through hole rivets, but they're fiddly to use without an expensive tool.

Lastly, make your own boards if you enjoy the challenge, not to save money or time as you probably won't.

[timofonic]

I want to do my own UV exposure box someday! I would like to make it progressively: Basic to double sided, MCU controlled and vacuum.

What's better for UV? LEDs or fluorescents?

Some people say UV LEDs are nice if placing them correctly in the PCB, others say nothing beats UV fluorescents.

What's the real deal? Are there scientific facts?

I have a list of UV exposure box projects, I can publish them here if you want.

[matrixofdynamism]

For all those that are saying that doing PCBs this way won't save any time or money, could you briefly explain why this is so. I mean, if it still takes long and costs as much as getting proffesional boards (1% or 2% saving is insignificant) then why do people even try home made PCBs with all their limitations? Why not just get a professionally done PCB with its silkscreen and plated holes and whatever else comes with it .... gold plating e.t.c

I have become really confused here now.

[IanB]

(10) Most important, safety equipment. This is gloves, eye protection at the minimum. It is important to use etchent in a well ventilated space as it releases fumes. No stains are acceptable from the etchent anywhere, not on clothes, not on any surface. Ethchent can damage sink pipes if put into sink. It must be neutralized before being thrown away

There are no fumes with ferric chloride. Also, check out Big Clive's recent videos on the subject. Some interesting techniques shown:

https://youtu.be/W_oDBp_wgJQ

[Asmyldof]

It is to do with experience, fun and hobbyism.

20 years ago we started doing it, bought all the stuff and then it was actually the better way of making your own little hobby prototype.
Even 10 years ago there were financial arguments.

People starting now, more often than not, do it just because they enjoy it.

I still do it, because having all the equipment and materials in bundles, the material cost is negligible, I enjoy doing it and it does mean I can go from idea to PCB in as little as 2 days if it's not too complex or critical, driving the next design that will then be produced by a fab, somewhere in the world.

If I order half a m2 of PCBs, groove cut in small panels from a Chinese fab I trust with my work (also had my Business cards made there), it costs $40 to $50 for up to 4 layers of just the PCB with the cheapest finishings.
If I make half a m2 of 2 layer myself, the time prepping alone, at minimum Dutch wage (which I'm above by quite a large margin) would cost me that, and I have no PCBs at all.

[M4trix]

others say nothing beats UV fluorescents

+1

At least it's cheaper than LEDs. 

[Dago]

Most of the guides I see seem to be terribly complicated and involve all kinds of expensive specialty stuff like UV lamps and what not. I do PCBs in a much simpler way.

All you need is a regular fluorescent desk lamp, laser printer, transparencies, thin glass sheet (Ikea picture frames have a suitable one), two cups, some drain opener and something to etch the board with (I use sodium persulphate).

Print the design (mirrored) on the transparency, put it printed side down to the board, put on glass sheet, expose for a few minutes (specific time depends on the boards, with my 11W lamp usually takes 6-10 minutes or so), then develop in ~3% drain cleaner (NaOH or KOH) solution, and then etch. Very simple. The only limitation really is that you cannot make large boards too easily because the exposure starts to get a bit uneven. I pretty much never make large boards so it is not an issue.

Board I made yesterday (didn't use a premade board, sprayed the teflon substrate myself with photosensitive lacquer):

[Howardlong]

I am not sure you necessarily "save money" if the direct costs of setting yourself up are taken into account compared to using some of the cheapo board houses.

The Mikeselectricstuff PCB primer is spookily very close to the process I've used myself for some years.

The key thing to note is that it will take quite a bit of experimentation before young get it right, so you need to be patient and expect lots of failures, but you'll get it right eventually if you keep at it.

So why do I DIY my own boards? Largely these are not for final use, they are for unit testing parts of a final design. Things like RF, SMPS and high speed stuff you can't breadboard and expect a representative result. Some specialised packages too demand a board although I do keep a reasonably large stock of common breakout boards for most packages.

But for a quick unit test, having to wait for a board to come back from the board house interrupts my workflow and I'd rather just get that part of a design finished. In half an hour, I can have the stuff set up, a board out and cleared away, but it took a lot of boards, dozens and dozens, and many failures, before I perfected my process to this degree.

Some tips...

You should use a mini drill press to drill the holes. Trying to do it by hand will end up in lots of broken bits.

If you don't already wear glasses, consider wearing safety glasses. I'm not usually a health and safety freak, far from it, but those chemicals are pretty nasty particularly the ferric chloride.

If you need a sink, make sure it's ceramic. I had a stainless steel sink once that is now a reasonably good sieve. Things were a little frosty with SWMBO for a while. So I also recommend pre-mixed ferric chloride rather than mixing your own too. Ferric chloride will also permanently mark and eat through your clothes, so best leave that suit and tie in the wardrobe.

All of my chemicals are kept in annotated takeaway or other sealed plastic containers. These containers are all kept in a clearly marked plastic storage box and kept safely stored away.

Using surface mount parts dramatically reduces the number of holes that need drilling.

[ElektroQuark]

If you read Spanish you will find what I use and how I etch PCBs it in my blog.
I describe the process and used equipment and chemicals.

[kerrsmith]

It does not cost too much to get set up, all the chemicals you need can be bought on Ebay pretty cheaply and you use so little of them they will last for ages.

The method I use is shown in the link below:

https://www.eevblog.com/forum/eda/home-made-pcb-etching-using-uv-light-tubes-by-using-negative-dry-film-photoresis/msg645925/#msg645925

This method produces really good clean boards and even my very first one turned out really well.  Most of the process is done by eye so you just need to look to make sure everything has dissolved or etched away and you then should end up with a really good looking board.

I would recommend creating / downloading a test PCB with lots of different sized tracks and pads on it, once you have this you can use it as reference when you are creating your PCB in software so you know how small you can go with tracks and pads.