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View Full Version : has anyone used uv curable ink for pcb making?



chris bate
24-04-2010, 03:27
hi all,,

i'm sure most of us are aware of the high prices of photoresist not to mention the lack of suppliers of the stuff,
so now i'm wondering has anyone tried using uv curable inks for making cheap pcbs and other applications ?

for reference rs components has photoresist in a 200ml spray can for $29.40AUD
where as black uv curable ink costs somwhere around $14 per kg and cmy colors a bit more

SAborn
24-04-2010, 07:21
I have never tried uv ink.

You quote photo resist board is high priced, I tend to disagree and find it rather cheap for the quality an easy use.

Try searching for "Kinsten" circuit board as there is a supplier in Perth Australia that sells 300 x 400mm sheets for about AU$30.00 and that will give many cheap boards from a sheet that size. (its what i use)

Kinsten is a good quality board and works well.
There is several backing material types available to, and some cheaper than others like the stuff that strip board is made of is cheaper than the fiber glass board. (i use Fg)

It would take hell to freeze over before i went back to using that spray on resist or uv inks etc. after so long using pre coated board as i think it works out cheaper in the long run.

Dippy
24-04-2010, 07:29
Can you explain your suggested process please.

Obv photoresist spray acts like normal photoresist which gets weakened under UV. And then the developer removes the weakened parts.

How will your idea work?

I must admit my experience with photoresist spray has been a bit hit and miss.
And the minor cost saving werre outweighed by the cost of cockups (materials and time).
Maybe I'm just cack-handed , but I would't even bother wasting 5 minutes with it.
Maybe it's OK for arts and crafts stuff.

In UK I tend to get the (UK made in Brum I believe?) Fotoboard 2 which is reasonably priced in Rapid. Top quality and 100% success.
And the stuff I have seen sourced somewhere on Ebay looked like the copper had been applied by a chimp with a decorator's paint roller.

Grogster
24-04-2010, 07:41
I too use Kinsten brand pre-coated PCB's, and they have never let me down, despite the fact that I make lots of boards for prototypes etc.

I wouldn't touch the spray-on resist, as it is practically impossible to get a consistent and even coat on the board - there will always be areas that have a thicker coat then other areas, and this can mean that some of your pattern develops correctly, but the rest does not.

Dippy
24-04-2010, 07:43
I agree.
Chris, forget it.

However, if you were to find some quick-drying etcher-resistant ink cartirdiges for my Canon printer and CD sized Bare copper PCB I'd be very interested.

chris bate
24-04-2010, 08:32
thanks for the kinsten lead,:)

from what i've been reading it should be quite usable as a photoresist it comes in a tub and has a thin grease like consitancy so i don't think it would work well in ink cartridges, although i'll ask the agent if there is a compatible thinner for it,

i have two proposed uses for it
firstly pcb making,
secondly making offset impression source rollers for a small A3 offset printing press i've recently started to build, ( very early days )

aparently you can "paint"
it on a surface and it will just be "tacky" until you expose it
then after that it should safely wash off with solvent leaving behind the cured ink.
the only thing i imagine could become a problem is the artwork and the cured ink sticking together and possibly worse pulling the cured ink away from the pcb/roller

i'm picking up a free 100ml sample of it on tuseday so we'll see, what happens,

SAborn
24-04-2010, 12:10
I like the colourful discription.


And the stuff I have seen sourced somewhere on Ebay looked like the copper had been applied by a chimp with a decorator's paint roller.

I just dont understand why people see the precoated board as "High Priced" and then spend a fortune on other crap that gives poor results.

If you start with crap, than the end result will be crap, as it aint going to get any better once it is etched.

Marcwolf
24-04-2010, 12:31
Hi.
I have been making my own PCB's for a few month now with the Kinsten boards and it has been SO easy.

For the UV source I use a Nelson UV Fluro Blacklight, a home made light box

Kinsten board is $13.50 for a 150 x 300 fibreglass board (Cheaper if you want phenolic), and $3.00 for the developer.

I use ferrous Chlorides - ok its messy but it works at room temperature.

To make the boards I use DipTrace and print out onto transparencies from my laser printer.

To add everything up the initial layout willl be around $50 and you can make a lot of boards.

I have looked at many other ways in the past to make board (even hand layout with stencils in the 80's) and this is by far the easiest for small projects. Once you have the board you can use the Diptrace format to get many more done from one of the Chinese board producers.

Hopes my opinion helps

Dave

Dippy
24-04-2010, 13:22
Many people already use a similar process, Dave - and get very good results.
There are many posts on this Forum already for 'My Favourite' Etcher.
Some use Press'n'peel iron-on stuff so we'll probably get a great list for those too.

I take it therefore that Chris's idea is to
1. Paint it onto a copper-clad board.
2. Make a reverse PCB artwork.
3. Expose.
4. Wash in solvent to remove unexposed goo.
5. Etch it and then remove the cured ink somehow. (I hope it's soluble in something :) ).

Will this be a contact print?
Will it sit flat?
Will your negative get 'glued' to the ink?

Sound like a lot of hassle to save a couple of quid - especially as the pukka stuff can give 100% cockup-free results and start to finish ~45 minutes.

Maybe you could use your offset printer to print the ink onto copper.
Or screen print - I'm sure it's done already somewhere.

Anyway, interesting stuff, good luck and let us know how you get on.

vshortt
24-04-2010, 15:19
This might be a little off-topic but I've used UV ink in a different way, I purchased a gallon of green UV ink, the type that a silkscreener would use, to make a solder mask. The trick is to thin it out with laquer thinner. I don't know if anyone else has tried this, but I would imagine I'm not the first.

I just the board using the toner transfer method and then make the mask by spreading the UV ink on with a brush, use a transparency to make the solder pad mask, then place the transparency over the board and use it to "smooth" the green paint. 30 minutes under UV light and I can wash away the uncured green paint with solvent and have a professional looking solder mask that works great and protects all the traces. you can even re-apply the legend over the top using the toner transfer method (even though it's not white like a silkscreen legend, it still looks great).

The gallon was about $20 and I use just a few drops on a 3x5 board, I would imagine the gallon well go bad before I get a chance to use it all, but thats the smallest amount I could find it in.

chris bate
25-04-2010, 10:59
Dippy,
i do know there are a few pcb manufacturers in china that have used a crude offset printing machine to produce large pcbs eg motherboards... ,
and have actaully had some success with it

but they are using the usaul industry way of making the impression source cylinders which is lithographic plates from the likes of agfa and kodak, and between the plates and the developer and the exposing equiptment i'd need a small home loan just to afford it all,

where as i'm looking at a cheaper way so far all indications are somewhat good, i just hope that the uv ink once cured is able to stand up to being used in such a manner,

i'll be very interested to see as well if the cured ink is resistant to ferric chloride because obviously if it is, it would make a safer alternative to photoresist since you are only then dealing with badish chemical and not two ( not much of a justification i know )

however the primary use i intend for it is making the offset impression cylinders for my mini offset press,

Vshortt,

thanks for the insight thats actaully very helpfull,
does the transparency stick to the cured ink or hasnt that been a problem?
how scratch resistant or durable is the ink after being cured?

Dippy
25-04-2010, 11:31
Aha, I see,, direct printing of artwork onto certainly seems a slick idea.
Hobbyists have been trying a similar inkjet-onto-copper method for ages.
I thought your plan was complete coverage of copper then placing artwork against it to all selective curing, then washing the soft stuff off.


"i'll be very interested to see as well if the cured ink is resistant to ferric chloride because obviously if it is, it would make a safer alternative to photoresist since you are only then dealing with badish chemical and not two"

- is that entirely true?
Apart from smelly paint, you will have to remove the cured paint after etching or else you won't have any exposed pads to solder to.
So, that may require a "badish chemical" solvent to do that (?).

Is it really worth the costs/hassles/time for one/two off PCBs compared to the 'traditional' approach?
With fresh 'badish' chemicals you can go from laser-print to etched PCB in 30 minutes.
And reuse the artwork transparency as it won't be covered in gooey paint ;)

chris bate
25-04-2010, 13:34
- is that entirely true?
Apart from smelly paint, you will have to remove the cured paint after etching or else you won't have any exposed pads to solder to.
So, that may require a "badish chemical" solvent to do that (?).

Is it really worth the costs/hassles/time for one/two off PCBs compared to the 'traditional' approach?
With fresh 'badish' chemicals you can go from laser-print to etched PCB in 30 minutes.
And reuse the artwork transparency as it won't be covered in gooey paint ;)

well i suppose the proof is in the pudding when it comes right down to it as far as chemicals and the dangers, one way i intend to try and remove the cured ink is to "overcure" it with the uv light since it's supposed to become very brittle and it might simply rub off, the other thing is i'm hoping a simple hydrocarbon like petrol or turps might disolve it away or soften it enough to simply rub off, we know with photo resist even the exposed photo resist can still be removed with sodium hydroxide with high concentration or longer periods

for pcb making it's probably a total waste of time given the kinsten leads in the previous posts, however i still need to look at it for making the offset impression source cyclinders, which is where it's going to be really interesting

as for the artwork when making the cylinders it isn't all that important that it survives since once the impression cylinders are made they only have to survive upto 2000 impressions (contacts with the rubber blanket roller) before it'll be removed and replaced by the next one

Minifig666
25-04-2010, 23:34
I agree.
Chris, forget it.

However, if you were to find some quick-drying etcher-resistant ink cartirdiges for my Canon printer and CD sized Bare copper PCB I'd be very interested.
If only they made flexy pcb that I could just feed into my schools laser printer when the tech wasn't looking it would all be so much easier. I feel an invention coming on...
Me (walking into cartrage world): Hi, can you top these cartrages up for me please?
Guy: Yeah sure, black or colour?
Me: Ferric chloride please!
Guy: What?
Me: Or etch resist then.
Guy: Sorry, we don't do that...

centrex
26-04-2010, 01:46
For Chris Bates
Seeing as you live in Hoxton Park Aus look up Acetronics on the web you will find they have pcb material and they are just on the other side of the river at Liverpool. They will sell you whatever size you want, it requires negative artwork,

chris bate
26-04-2010, 06:47
For Chris Bates
Seeing as you live in Hoxton Park Aus look up Acetronics on the web you will find they have pcb material and they are just on the other side of the river at Liverpool. They will sell you whatever size you want, it requires negative artwork,

i'll give them a visit on tuesday after work i think.... thankx :)

pcbguy
30-07-2012, 16:05
it's hard to find a black uv curable ink costs around $14 per kg.