DIY PCB Idea

Minifig666

Senior Member
It would seem I have sparked a big debate here, and I may be about to start another...
First off, is buying crystals any better than buying in liquid form?
Also, the photo board from rapid. Is the professional version worth the extra cost or should I stick to the economy stuff?
Also I would like to thank everyone for the advice they have given, even though it isn't my post! Maybe this could be stickied?
 

Dippy

Moderator
It won't get stickied, so forget that :(
Save it as a favourite.

Crystals versus liquid?
Dunno, convenience of less stirring?
But, downside is transport and storage hazard.
And I would guess that crystals will have a longer shelf life(?).

I've found the economy board from Rapid to be very good.
It's not so tough or stable as their Fotoboard FR4, though the benefit is that it's kinder to your drill bits and saws :)
For crucial circuits I'd stick to FR4 as some App notes give PCB layout data specifically for FR4 spec PCB.
But for flashing LEDs and clicking relays the cheap stuff should be fine.

Both types appear to have a very even copper layer which obviously improves contact print resolution. Probably better for the iron-on stuff too - don't know as I don't use it.

Looking at Mega may be worth a 20 minute visit...
http://www.megauk.com/pcb_laminates.php
 

vshortt

Senior Member
Perhaps someday I will look into doing the photo etching. I like the "warm mums iron up" - quip. That's cute! In reality the iron is usually warm well before I'm ready for it - I quit using mum's iron 20 years ago though.

I continue to say that if you do the toner transfer method right and take your time, you will get almost as good a result as you would get with the photo-resist method, the raw copper PCB's I use are made by GC Electronics, they are Rohs compliant FR4 boards that are 6"x9"x.0625 (15.25 x 22.86 x 1.6 cm) with 1oz copper cladding. They are mil-spec MIL-S1394H CF - these are good, high quality boards. Good enough for anything anyone can lay out on them.

The cladding is smooth and perfect, each is individually sealed in it's own plastic bag. I can get two really big boards or numerous little boards out of one sheet. I bought a pack of 20 for $20 US with free shipping off of the big auction site about 6 months ago. Haven't have any trouble with them whatsoever with the toner transfer method. I am sure there are junk PCB's out there, you just have to watch what you buy.

So, a $1 us for a 6X9 board is a HECK of a good price. $.02 for the toner, and $.10 for the piece of paper. toss in a pennies worth of sandpaper, and a $.05 worth of alcohol, a $.10 set of gloves

You're talking $1.27 for the board. At $.20 for the etchant above and you can make a 3"x5" board for $1.47 US start to finish, at least that's my cost.

Can't say I've ever been shot, but I've had to belly-land a Beechcraft Bonanza and lived to tell about it, does that count? LOL
 

sid

Senior Member
For what it's worth take a look at this youtube clip
http://www.youtube.com/watch?v=wKEe3otWstM
I've stopped making circuits on anything other than homemade pcbs now.
I thought the hole drilling would be a pain, but to be honest when your all set up you can drill a board with over a hundred holes in less than 5 minutes.
making your own pcbs has so many advantages over the veroboard, the main one being (as long as the circuit is correct) the board will function first time most times where as veroboard ALWAYS has a construction fault on it somewhere.
Give the pcb method ago , like anything it gets quicker and easier with practice, you won't be dissapointed
 

kevrus

New Member
I,ve been following this thread with interest. I use the photoresist method and used to use inkjet compatible tracing paper. A short while ago, someone on this forum suggested using ordinary plain white paper so I gave it a try.
Although I had to increase the exposure time from 90 secs to 180 secs, results have been equally as good. I use board from Rapid and ESR.
Anyone tried the modifying of an epson printer to direclty print onto the board? ive read a few articles on it, just curious if anyone here has tried it.
 

nbw

Senior Member
Etching isn't as hard as one might think. I use the toner transfer method, iron it - my wife is most impressed - and etch. I am fortunate enough to have a mini drill press - rather than the "hand job" ahem, and that makes drilling a breeze. About a dozen holes a minute.

I can usually get 0.2 - 0.25mm traces coming out just fine.
 

Dippy

Moderator
No, I've never tried it.

How do they stop the ink splodging or running into globs?
Do they precoat the board with something like the coating that inkjet CD/DVDs get?

Drilling holes? I reckon, by hand, I can do twice that rate. Then I get bored. However, if using tungsten bits if would have to be a drill stand.
 

nbw

Senior Member
Also: I use ammon. persulphate. It is a nice clear solution when mixed, is pretty quick, and you can get it in crystal form.

Another tip before I go to sleep (Not a boring thread, just I'm heading off to bed) - use a sheet of tissue paper between the iron and toner transfer paper - it saves the iron sticking / melting the plastic.
 

SAborn

Senior Member
I,ve been following this thread with interest. I use the photoresist method and used to use inkjet compatible tracing paper. A short while ago, someone on this forum suggested using ordinary plain white paper so I gave it a try.
Although I had to increase the exposure time from 90 secs to 180 secs, results have been equally as good. I use board from Rapid and ESR.
Anyone tried the modifying of an epson printer to direclty print onto the board? ive read a few articles on it, just curious if anyone here has tried it.
Try using plain paper and wipe cooking oil over the paper before you expose the board, it will make the paper translusent and it works a treat.

Just make sure you wipe any oil smudges off with a soft tissue before you develop the board.
I have done this method for years with outstanding results, on a thousand or more boards.

Epson printers (bubble jet) use a non waterbase ink and it might work, but most bubble jet inks are water based and would wash away.

Photo resist board is cheap for the quality it gives and would be less than half the price of vero board of the same size.

Once you have photo resist board making in hand you will ask yourself why you dicked around with other methods for so long.

UV Leds work a treat for exposure and if you buy them in clusters it not very expensive.
 

Dippy

Moderator
I've found that >80gsm tracing paper went through my laser quite.
And quite cheap to buy.

I like life easy and really don't enjoy pizzing about ;)

SABorn, do you get better results if you use expensive extra virgin olive oil?
 

kevrus

New Member
I found that plain paper worked just fine without oil, just needed to increase the exposure time. I also use the persulphate...much cleaner and easier to monitor etching progress.
as a matter of interest, my UV box has 4 x 15w actinic tubes.
Regarding the epson printer, apparrently heating the board after printing fixes the ink to the copper, but it does need to be pigment ink and not water based, hence it appears that epson printers are the popular ones for this.
 

SAborn

Senior Member
SABorn, do you get better results if you use expensive extra virgin olive oil?
Whats a virgin olive? thought that was what Popeye had.

As for the oil ...the cheap and nasty stuff i use. Sunflower, but yes virgin before you cook your fish and chips.
 

JoeFromOzarks

Senior Member
Reliability

I find it most peculiar - spending so much time experimenting with so many processes to simply create a PCB (printed circuit board.) Why debate the expense of $1US (0.710884 EUR/ 0.618047 GBP/ 0.985319 AUD) or $5US (3.55442 EUR/3.09023 GBP/4.92659 AUD) simply to determine a tad one way - or another - of predictability.

What is YOUR time worth? How many “dammit’s” are you willing to expend building your creation? If your nickname is Einstein or Edison or Tesla then knock yourself out – burn up 1000 failed methods to prove 1.

If you require or prefer an excuse to prevent a successful completion of your project, a failed PCB production run might be the best. The rest of us are crafting projects to conquer an objective. I suppose I am asking, what do you enjoy the most?

Me? A finished, properly functioning project. “Almost always” just doesn’t cut it.

Eliminate as many project crashing variables you are able. Select brand name components, meter your components, do not cheat specifications to save a penny, (0.00710884 EUR/0.00618047 GBP/ 0.00985319 AUD) just to experience the pain of heart ache and disappointment.

A time will come when you will consider what task or project will resolve your problem, you’ll no longer consider the tasks keeping you from creating your project.

Quoting the fellows from “Wayne's World:” BUILD ON!! Translated, that means "asphinctersayswhat?"

:) joe
 

Dippy

Moderator
Oh so true. A fellow quality advocate.

Though I have to say, as this is a hobby Forum, do what you are comfortable with.

I too include time-spent and failure-rate and remedial-repair in my equation.
As I am lazy and tight-fisted (relatively) I am determined to make something work first time and as quickly as possible using non-Ebay bits - I'm not THAT tight!

But, Joe, you have to remember that SOME people on this Forum would drive a 100 miles or faff about for a week to save themselves 50 pennies. Others like to make-do or experiment.

It takes all sorts. In fairness, it is often interestinf and informative and usually amusing.

And, yes, I had a private bet that someone would mention Popeye ;)
 

JoeFromOzarks

Senior Member
@Dippy

Yes, you are correct. This is a hobby forum, and an experimenters and tinkerers forum. I suppose my aging has brought forth a window of predictability and expectation of reliability. I shall change my handle to “ol’-Geezer.” (grin)

I too had the desire to “faff” about back in the ol’ days. Put the top down, open a cold one, cruise the roads wondering what I was chasing… I think my folks called me “fidgety.” For years I thought “fidgety” meant I’d break my stride, and neck, to check out the skinny blonde…

I’m still “fidgety.” Skinny blondes, convertibles and back country roads…

OT, (@John) I’m attaching an image of the sloppy (quick) PCB pattern I used to test the exposure time of standard fluorescent lights verses fancy (read expensive) UV boxes. #9 was exposed for five minutes, #5 for twelve minutes and #1 for twenty minutes. Traces 4,5, and 6 were perfect, so ten minutes became my standard. I shifted a sheet of black paper from #9 to #1 to vary the exposure times.

Shame Popeye’s Olive wasn’t blonde… (grin) She'd look good in my ride! (not!)

:) joe
 

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SAborn

Senior Member
And, yes, I had a private bet that someone would mention Popeye ;)
You baited me you sod!

I hope you won the bet Dippy, but do it count when you bait someone?

I hope the profits helps relax that tight fist of yours.
 

Rickharris

Senior Member
Whats a virgin olive? thought that was what Popeye had.

As for the oil ...the cheap and nasty stuff i use. Sunflower, but yes virgin before you cook your fish and chips.

Resist - Resist - I can't - It's an olive with the stone still in it!
 

Rickharris

Senior Member
Methylated spirits also makes writing paper transparent but evaporates fairly quickly and leaves no mess behind.;
 

SAborn

Senior Member
Haha, too true.

You make me sound like one of the characters (alledgedly) in Captain Pugwash.
I must admit i liked Popeye and Captain Pugwash as a kid, it was one of a few cartoons we got in the country on the B&W TV.

Looking back Captain Pugwash was less than a "B" grade cartoon, If not some of the worst animation ever done.
 

Dippy

Moderator
... wobbly bits of cardboard as I recall.

But then again, my '70s LEGO-block spaceship didn't look anything like a rocket.

But did it matter? Did it hell.... it's called "imagination" :)
 

John West

Senior Member
Heck, when I was a kid I used a pencil for a spaceship. You wouldn't believe what a bit of imagination did for it. Then my teacher would come over and it would crash. But I'm guessing this is a bit OT. No, wait. Spaceships have PCB's! :D
 
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SAborn

Senior Member
But I'm guessing this is a bit OT.
Blame Pugwash for that, he started on Olive Oil.
I was waiting for Brutis to join in.

As for wobbly bits of cardboard, use your imagination for animation.

Now im sure Captain Pugwash was Picaxe controlled.
 

fathom

New Member
Bump

I've been making some PCB's with the toner transfer method and if I followed the instruction about putting the PCB with the template in the water to remove the paper and every time I did this the toner fell off the PCB as I removed the paper.

I have had some success using the backing off of laser printer labels and printing on the greasy side and then using a warm iron set at wool setting or if you have a thermocouple thermometer about 130 deg C to 135 deg C which is the temperature that toner becomes sticky, any higher and it melts and the toner will smudge and fine tracks becomes one sticky blob.

I used the iron to preheat the board for about a minute and then used the iron on the board for about 2 minutes and then whilst it was hot peeled the backing off the board without putting it in the water. Then let the board cool and the toner will stick. If the tracks are thin you'll need less heat than if the tracks are thicker so you'll have to experiment. If some of the toner comes off you can touch it up with maker pen.

I also had success using PC World own brand glossy ink jet paper also peeling the paper off when it is hot rather than putting it in water.

Also newer laser printers no matter how you try to frig the settings to get as much toner on the paper will not work as printers tend to be economical. However my old Canon copier which is 20 odd years old works perfectly and it dumps more than enough toner down.

After etching I used a small brass bristle wire brush to remove the toner and even with the fine tracks there was no damage.

Here is a picture of a 28 pin SSOP to 28 pin DIP adaptor I made for a MAX7456. The tracks are 0.3mm wide and etched perfectly.

 

vshortt

Senior Member
Fathom, I'm sorry you've had trouble with the paper-soak method. I'm using a new Xerox Phaser 6120 to make all my transfers and haven't had any trouble at all. The main cause of lifting with the toner method as you've described is not scuffing the board with a coarse enough sandpaper. To have success with this method, you have to thoroughly scuff the board with 220 all over. There shouldn't be any smooth areas left when you're done and the sandpaper should have a copper sheen on it. Using finer paper or even schotchbrite won't provide a rough enough surface for the toner to stick, so it will lift off. That can happen in either the water tray or in the etchant - where it's irreversible.

In fact, the only trouble I've recently run into was that I left the board in the etchant too long and lost some of the small traces, but that was my own fault.
 

Dippy

Moderator
Lordy, if you can afford a Xerox Phaser 6120 then it means you could afford a UV box , photoboards etc. and produce higher quality PCBs :rolleyes:
 

SAborn

Senior Member
Lordy, if you can afford a Xerox Phaser 6120 then it means you could afford a UV box , photoboards etc. and produce higher quality PCBs :rolleyes:
Dippy i have come to the conclusion, some people just like to do things the hard way, when it comes to making circuit boards.
 

chris bate

New Member
Dippy i have come to the conclusion, some people just like to do things the hard way, when it comes to making circuit boards.
it's a very relative issue some people think certain processes are easier and cheaper than others, and because of our western world profit driven culture people are hard to convince and opinions very hard to correct,

so far the simplest method is to simple print your design onto plain white 80gsm paper place it design down on top of the presensitised pcb and expose for 10 mins with a 14watt energy saver from 200mm roughly, can't get any simpler, and i can get 0.2mm traces,
 

Dippy

Moderator
Slight Red Herring:
When you say "a 14watt energy saver" are you referring to a CFL lamp/light-bulb?
i.e. those cheap things from China that come over by the boat-load.

I know the guts of them so don't need a physics lecture, but do they really chuck out that much UV?
Does hippy know this? He'll ban them! ;)
 

Minifig666

Senior Member
Dippy, remember most of that 11-14 Watts that goes in is used to make UVb. The phosphor coat can't catch that much of the UV to convert it, just most of it. When you think also that these things are produced by the MT in China they aren't going to be that well made are they?
 

Dippy

Moderator
Like I said, I know the guts. I did a physics lesson once so don't forget the filtering contribution from the glass ;)

I was just wondering how much UV (of whatever type) came out.
And, no , I can't imagine safety (over cost) being important to certain manufacturers.


Many years ago I did a couple of PCB using 70gsm standard paper.
It required >3 minutes exposure in a proper 4-tube UV box.
I can't remember tube wattage, but the distance is only about an inch - and remember a UV box has reflectors.

So, very roughly:
Me: 3mins at 25mm
CB: 10mins at 200mm
Sun: X mins at 93m miles.

Even if a factor of 2 wonky that suggests a healthy amount of UV coming out of a CFL. Can this be right?

It would be interesting to do a test with some PCB and make up a little thing like the old fashioned film badges in the Nuclear industry. Good school project.
 

chris bate

New Member
So, very roughly:
Me: 3mins at 25mm
CB: 10mins at 200mm
Sun: X mins at 93m miles.

.
it depends on your paper some of it has a very very fine silicone coating on it especially the really thin stuff 40gsm to 65gsm to help with tensile strength so that might make a difference,

when i say energy saver i literally mean a cfl light you can buy off the shelf on woolworths
i was quite suprised it worked myself, before that i was exposing my pcbs under the flouros on the father in laws fish tank which also worked quite well

i would suggest they put out a fairly significant amount of uv and if one had any means of accurately measuring it you'd probably find things weren't exactly to the spec, as usall you get what you pay for,
 

manie

Senior Member
Energy Savers ? Now that sounds interesting, purely from an "availability" perspective. Here in RSA that can be an issue on some items, UV lightbulbs included.

Think I will try it at some time, seeing that my GE 125W UV light at +-250mm requires eight minutes exposure (it produses a "streak" of bright light and the distance is to prevent this....)

As always, good info on the site ..............
 

Dippy

Moderator
Loved the 70's synth. I think every man and his brother has made a "How to make a PCB".:)
Though, that was quite good.
I'll stick to photo/developer though I think. Only needs one laser print.
But as this subject gets saturated every 2 or 3 months I'll just say: do whatever you prefer.


On the subject of UV from CFLs.
This is very useful to expose and can cut costs hugely, though I must say that it concerns me on the Health day-to-day aspect.

This made interesting reading...
http://www.hse.gov.uk/foi/internalops/fod/oc/500-599/559-9app2.pdf
from
http://www.hse.gov.uk/foi/internalops/fod/oc/500-599/559-9.htm#_CFLs
and, albeit non-scientific, so did this:-
http://www.uvguide.co.uk/phototherapyphosphor-summary.htm

I'd love to know if some makes/types of CFL are more youvee than others.
We get some real cheap crap from you-know-where ... I wonder if anyone has ever tested them?
People (apart from me) will always buy the cheapest chchod available - makes you wonder.

Anyone tried quartz/tungsten/halogen lights as a UV source?
If thet are removed from an glass layer, they chuck out UV too.
 
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