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[Questions] UV PCB transfer

Posted: 03 Nov 2009, 18:47
by chicago_mike
1. Will simple blacklight bulbs work? I see some places mention bug zpper bulbs. 30watt or less okay? I have a gooseneck light I can use.

2. Transparency film? Will this kind work? http://www.staples.com/Apollo-Multipurp ... rea=SEARCH

3. If I use a normal shaped bulb, and not a tube, Do I still need a box? Or can I shine the light straight down on the board / transparency..to get the trace on it?

4. Cuastic Soda. Will my local Homodepot or Mynads carry this?

thanks.

im kinda done with gloss paper method... its okay, but a serious pain.

Re: Questions on UV etching method..

Posted: 03 Nov 2009, 23:21
by culturejam
chicago_mike wrote:1. Will simple blacklight bulbs work? I see some places mention bug zpper bulbs. 30watt or less okay? I have a gooseneck light I can use.
Just about any fluorescent light will work. I even used a cheap "work light" (mini flood) from Home Depot a few times. No need for fancy lighting. Even sunlight will work just fine.
chicago_mike wrote:2. Transparency film? Will this kind work?
Yep
chicago_mike wrote:If I use a normal shaped bulb, and not a tube, Do I still need a box? Or can I shine the light straight down on the board / transparency..to get the trace on it?
Yep. I used a piece of glass from a picture frame to hold the transparency flat on the board and then shined the light on the board for maybe 5 - 7 minutes.
chicago_mike wrote:4. Cuastic Soda. Will my local Homodepot or Mynads carry this?
Not sure about this.

Re: Questions on UV etching method..

Posted: 03 Nov 2009, 23:50
by chicago_mike
NOT SURE???? NOT SURE??????

DUDE!!! You have like EVERY Answer except number 5!!!


Im so ashamed of being the one who secretly started a facebook fanpage for you.... :P


Umm, but thanks for all the other answers... :mrgreen:

Re: Questions on UV etching method..

Posted: 04 Nov 2009, 01:38
by culturejam
chicago_mike wrote:Im so ashamed of being the one who secretly started a facebook fanpage for you.... :P
You are an odd fellow. But I like you anyway. :thumbsup

Re: Questions on UV etching method..

Posted: 04 Nov 2009, 02:10
by chicago_mike
why be normal? :D

Re: Questions on UV etching method..

Posted: 04 Nov 2009, 03:33
by RnFR
found this instructable on the topic.
http://www.instructables.com/id/Killer-PCBs/

looks like a great method. i might have to graduate to it someday.

Re: Questions on UV etching method..

Posted: 04 Nov 2009, 12:06
by Kilby
OK I am probably the cheapest person in the world (cos I have no money)

I have been through the regular paper and press n peel blue options. PnP blue is OK once you get used with it, but expensive. As for the paper method I found that a little too inconsistent for my liking and a PITA. I tried using regular fluorescent tubes but it just wouldn't act in any sort of consistent fashion regarding distance & exposure time (I gave up)

Anyway my solution was to buy one of these http://www.maplin.co.uk/Module.aspx?ModuleNo=4848 as they have a store locally to me. I'm also currently using their pre-sensitized board as that develops very reliably using caustic soda (in mine with my low expense lifestyle.)

Anyway I found that laser printing onto a (laser compatible) acetate sheet and using the clear front of a CD jewel case to hold the acetate flat on the board gave me perfect results with a 12 minute exposure (I know this is a long exposure but it is a small 4W tube and no doubt the (glowing) jewel case cover is doing something bad with the UV).

Once I get my hands on an old flatbed scanner I will mount a set of tubes inside and get the exposure time down (and allowing me to expose larger areas)

Other boards (lamps, acetates and even covers to keep the acetate in contact with the PCB) will no doubt yield different exposure times, so I suggest using test exposures ranging from 4 minutes to about 20 to find what is best for your setup.

I would have done some tests with sensitizing spray & regular copper but my beloved wife decided that as it didn't belong to her it could be thrown out (so I cant give much advice except it is useless without it's proper developer)

Hope this helps a little

Rob...

Re: Questions on UV etching method..

Posted: 04 Nov 2009, 12:24
by RnFR
yeah rob, thanks for the tips! i've gotta say, this is looking more and more attractive to me. but i have to ask, instead of a jewel case, why not get an old picture frame from a thrift store and pull the glass? you might have better results, and i'm sure the heavy glass would hold the transparency a bit better.
that spray is intriguing, too. i take it if you screw up the developing, you can just try the same piece of copper over again? anybody use the spray? there is also a resist material that comes in sheets and you use some sort of laminating machine to get it on the board. i've read it works well, but you have to invest in more gear.

Re: Questions on UV etching method..

Posted: 04 Nov 2009, 13:19
by Kilby
Heh with real world workloads and family commitments I seldom get the time to do anything other than the care essentials and that includes junk shops :( so I grabbed the 1st thin transparent item I had to hand (it was 01:00 am before I even got time to do the exposure tests). From then on I just went with the methods I had timings for.

TBH once you get the setup working you get very repeatable results will not want to go back to iron on methods (though I learnt to layout boards using letraset and pens way back in the mid 80s).

Problem is that glass in photo / picture frames can often have UV protective coating so you will not know if the glass is coated or not plus it's thin (even though my kids are teenagers so many things get broken in the household it's ridiculous). Eventually I will get time to do a full light box from a flatbed scanner with 4 or 6 of those little 4 W tubes and some suitable tempered glass.

As for the spray on photoresist this is the Farnell link http://uk.farnell.com/electrolube/prp20 ... /dp/130552.
You will need a good dust free atmosphere and to go with light coats (dry the boards on their edge). To dry once sprayed I dried the boards in the oven (using a ventilated coffee can hold the boards so they don't meet any UV) much to my wifes annoyance.

Don't bother trying to use caustic soda to develop it, use the official developer. I had absolutely NO success using regular fluorescent tubes for exposure, and those in sunnier climes (than Northern Ireland) may have success using sunlight.

Inkjet inks are NOT opaque enough (from my experience) and draughting film (fancy tracing paper) wasn't great, just go for regular acetate film (please make sure it is acetate for a laser or you will have to buy a new fuser for your laser).

Re: Questions on UV etching method..

Posted: 04 Nov 2009, 13:40
by culturejam
Mike, if you want some cheap and reliable developer, check Parts Express:
http://www.parts-express.com/pe/showdet ... N=53721209

That little bottle will develop a LOT of photo-sensitive boards. And after you mix up a batch of developer, it can be reused many times before it is exhausted.

Re: Questions on UV etching method..

Posted: 07 Nov 2009, 23:46
by chicago_mike
I bought the blacklight bulbs and will make a "UV etching thing-a-ma-bob" this weekend.

Ill get some non uv glass tomorrow..so long as i can find it at a hardware store.

UV ETCHING

Posted: 17 Nov 2009, 20:44
by chicago_mike
Hey all,

I am going to start UV etching of pcb's and need uv bulbs. I have everything else, transparency, etchant, positive resits remover...etc..

1. Will black light (party style) bulbs work? I hear yes and no so maybe they do but its not as good as straight out uv? I went to my local hardware store, as UV lights are sometimes sold as bug zapper lights. No go.

2. Will UV LED's work? I can get bulk packages on ebay in 20, 50, 100 qty. Or will this be fruitless? I think they are 7000MCD. 5mm size.

Re: UV ETCHING

Posted: 17 Nov 2009, 21:25
by lolbou
Hey,

I pick up my UV tubes from this ( a UV-light for face):
2676903738.jpg
2676903738.jpg (28.12 KiB) Viewed 3724 times
I've made a UV-box out of one and kept the other for extra tubes:
img_1516 800600.jpg
Good thing is: cosmetic tubes are the same size as classic 8W, but are 15W. Classic 15W are way bigger.

Bad thing is: I haven't tried these actually because I moved, and never got the opportunity since. From what I know, solarium tubes are UVA (300 - 400 nm wavelength), and actinic ones are more selective (350 - 400 nm) and more recommended... From this, my guess it it might take longer with cosmetic tubes...


I bought three of these units, containing 4 tubes each. One for 4€, one for 10€, and one for 15€. I made a 6 tubes box and so I got some 6 spares.

BTW, in these units, the tubes are good quality Philips Cléo.

I don't know much about LEDs though.

Re: UV ETCHING

Posted: 17 Nov 2009, 21:56
by chicago_mike
Most interesting.

etch AND beauty. Way to keep up appearances for business. :lol:

Re: UV ETCHING

Posted: 17 Nov 2009, 22:05
by RnFR
topics merged. :slap:

Re: UV ETCHING

Posted: 17 Nov 2009, 22:50
by chicago_mike
:slap: :slap:

:applause:

im getting old. :cry:

http://hackedgadgets.com/2009/04/21/diy ... osure-box/

Some one does etching with UV leds ..so..I guess it ought to work. :)

well anyways. Im going to try this out this week. Ill post my results. :popcorn:

Re: UV ETCHING

Posted: 18 Nov 2009, 18:12
by chicago_mike
It took me a few tries but I got my laserjet to print transparencies.

Prints nicer than on glossy paper! :applause:

next step is the "burn in" as I'll call it. This test is going to be awesome..its a roland jetphaser...finally!

Re: UV ETCHING

Posted: 23 Nov 2009, 05:41
by chicago_mike
First try tonight.

Went okay for a start...a couple traces didnt quite make it, but for my first time this is acceptable.

I can sharpie those in and etch. 8)

All in all, so much easier than glossy paper, rubbing the crap off, without rubbing traces off, etc..etc.

I bought a blacklight from menards as I cannot locally find any UV bulbs. about 12 minutes and I was done.

Next step is to get more pressure on the transparency and get the light closer. The bulb was possibly 5" from the film. Il get it down to 2" I think.

If I can get this method down to science relatively quick..Ill be able to almost mass produce boards.

Why I didnt do this sooner..I dont know..fear maybe. But those who have yet to try this method, go for it. :)

Re: UV ETCHING

Posted: 23 Nov 2009, 13:11
by Kilby
chicago_mike wrote: If I can get this method down to science relatively quick..Ill be able to almost mass produce boards.

Why I didnt do this sooner..I dont know..fear maybe. But those who have yet to try this method, go for it. :)
TBH it's the easiest method there is (should try the damn rub down transfer method for something really depressing) once you get a small amount of kit together and your timings together.

The next thing is to get your PCB design skills together and do your own layouts :wink:

Re: UV ETCHING

Posted: 25 Nov 2009, 06:51
by chicago_mike
Kilby wrote: The next thing is to get your PCB design skills together and do your own layouts :wink:
shut up. :P :P :lol: :oops: :cry:

so i did my second tonight....this UV stuff is awesome! :D so fekkin easy!

I bought a 2nd blacklight today and will buy one more. Then Ill devise a nice..box-top thingy to do all this stuff in.