Anyone willing to etch some PCBs?

[The Master]

Hi, Does anyone have the equipment to etch PCBs and would be willing to etch some for me at low cost? The boards are pretty small (1 for example is 236.22 X 12.7mm). Single sided. The designs arnt complete yet but i will probably need about 30-50 total (about 15 different types). They dont need drilling or solder mask or anything (just etching). I would prefer it if they can be cut up into individual boards but i _could_ do that myself.

Im in the UK so i need someone who is either in the UK or who can send PCBs here at low cost.

If your are interested please state _roughly_ how much you would be willing to make 50 PCBs for assuming 236.22 X 12.7mm. I expect to have all the designs done within a few weeks so we can discuss a more accurate price then.

I use PCBWizard but i can export to gerber files

[duncan303]

Hi,

I agree that single sided, single layer,no vias,no holes, no soldermask, no legend makes it very easy, so easy in fact.................

maybe........ depending on the component density and signal widths, isolation width to the ground plane, you may find that all you need is some presensitised board, a cat litter tray, some etchant and a printer capable of laying on a dense image onto a translucent paper/acetate. Oh and the sun shine for UV source, if you are lucky. :)

you say the boards are assorted and you mention one 1/2" x 9" well its the panelisation that is going to take time. Will your layout software allow you to arrange multiple designs onto a single printout?

I know this is not the answer to your question but i'm sure you would be able to succeed if you gave it a go, you could have a design from screen to bench ready for populating within the hour, how cool is that.


HTHH


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[The Master]

I can arrange multiple boards on a single sheet. I do have some equipment to make PCBs myself but the acid is no good at all now and after these boards its not likely that ill be making anymore for a while.

I dont want to buy more acid and unpack all of the equipment (some of it even needs finding first) just to do a few PCBs then pack it all away again and let the acid go to waste. The last PCBs i made didnt come out very well either and i wasted a lot of time and didnt get the results i wanted.

[duncan303]

I was thinking of:
cat litter tray £1
Etchant £2.50
Developer £3
sheets of tracing paper 10p

plus the board

so you do not have to waste time looking for any old kit, it cheap enough to buy and dispose of what you do not use. None of the above have a significant limitation on shelf life.

Does your boardhouse not allow multiple designs? TBH I think maybe a boardhouse is probably the best route for you.

cost wise....... maybe just bite the bullet.

STTH

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[The Master]

Ive got the stuff you mentioned but you didnt put acid on the list. Thats expensive to keep replacing everytime i make PCBs (which isnt that often at the moment).

My first idea was to get a company to make them but they are all way to expensive for low volume.

[mackrackit]

Oh and the sun shine for UV source, if you are lucky. :)

an aquarium bulb also works well during an eclipse.

I will ad to duncan's list a cheap picture frame for the thin piece of glass to hold the transparency on the board while it is in the sun.

Do a couple of test to get the hang of it and see how easy it is.

Nothing like rolling you own.

[duncan303]

Etchant is ferric chloride which will dissolve the copper from the board
250g from rapid ~£2.50

What is the acid to which you refer?

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[Darrel Taylor]

I realize you want "cheap", but what are you willing to pay?

I could get 50 boards/15 types/9.3"x1/2" for $492, 2-day turnaround. That's $9.84 each.
No mask, no silkscreen, no routing.

That would be good enough for me ... what's your target?
Is it even worthwhile for someone to do it for you.

[The Master]

duncan303: Which acid is that your looking at? I paid way more before. Maybe i didnt even have the right type and thats why they didnt work out so good.

DT: Is that really considered cheap? Thats more than some companies have been quoting me. It seems like the PCBs cost more than the components that go on them :S

Looks like i really have no choice but to make my own

[Darrel Taylor]

DT: Is that really considered cheap? Thats more than some companies have been quoting me. It seems like the PCBs cost more than the components that go on them :S
I took the highest quote from SunStone, which still seemed "cheap" to me for QTY=50.

If you wanted 10,000 of them, they're 10 cents a piece.
The costs of development... or the pain of making them yourself ... :(

[duncan303]

I think one of the problems in europe is that we generally work to a standard size called the "eurocard" 100mm x 160 mm or double 233mm x 160mm at 228mm ish you are going to be very very tight. Most boardhouses require a minimum border.

you will get best prices for a standard eurocard can you adapt your designs to this size?

could you get all your designs to fit onto a single double size?

FR4 is just like real estate in Mayfair, make a design as small as your ability to hand populate.

I still think you should give a bash again at making the boards yourself, just think you will not need a separate picture frame if you just tape your pcb to the side of a fish tank :D

Dave is absolutely right you need to press the image as close as possible and evenly to the photoresist, it is fairly critical. you could even press the whole caboodle against a south facing window. The advantage of the sun is that UV quanta is, to all intents and purposes, parallel and in addition you will not have the problem of inquisitive little stationary fish.

if a little fish has the intlelligence to be inquisitive :)

as I remember you are a rapid lad
http://www.rapidonline.com/Tools-Fasteners-Production-Equipment/PCB-Equipment/Etching/PCB-Etchant/29447/kw/etchant


This is the adjunct on the forum where theory should become practice........ a painfull transition :D


STTH


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[The Master]

Yes i do like rapid. The stuff i got before came as a powder. Ive had a look on there but the only similar thing i can find is still a lot cheaper than what i got before. My tank is 5L so ill need the 2.5KG bucket at £14.25. Ive been told that the "normal" acid lasts a lot longer than the powder stuff i got before

[mackrackit]

The time it last depends on how much copper is removed to the amount of solution.
Ferric choloride is most often shipped as a powder. Why pay shopping for water and the package is easier.

What color was the "acid" that you used?

[The Master]

I know it depends on the copper removed. I only did a few boards in it though then there was a month or 2 gap before i did anymore. Aparently the powder version is only good for 6 weeks even if you dont use it.

The stuff i had was green. At school we used to have an orange acid which i think is what ill get from those pellets. Im told that the orange stuff lasts for 6 months easily

[Byte_Butcher]

The orange/brown stuff is ferric chloride.
The greenish blue stuff is probably ammonium persulfate.

[Darrel Taylor]

jmgelba was offering some deals on PCB layout and/or production not too long ago ...

http://www.picbasic.co.uk/forum/showthread.php?t=2850

Maybe he's still looking ??

[Archangel]

The orange/brown stuff is ferric chloride.
The greenish blue stuff is probably ammonium persulfate.Nitric Acid goes blue after first use too.
You might think good thoughts about printing your Positive in mirror image so you can put the toner side against the copper, so the .010 or .020 thickness of the plastic overlay does not diffuse light onto your traces.

[The Master]

You might think good thoughts about printing your Positive in mirror image so you can put the toner side against the copper, so the .010 or .020 thickness of the plastic overlay does not diffuse light onto your traces.

Im pretty sure thats how ive been doing it but ive been using an inkjet printer (with special inkjet PCB transparencies). Ive borrowed a laserjet now though and ive got some laserjet transparencies somewhere.

Thanks DT. Ill send jmgelba and email

[toneman]

check with the Yahoo DIYpcb group.
I'm sure there are some UK members(?)
Maybe someone can help U out while etching their own stuff(?)
Would help pay for their materials/etchant.
good luck!

[jonewoo]

It is very important that the printer produces a good solid black with no toner pinholes.If you're planning to buy a printer for PCB use, do some test prints on tracing paper to check the quality first. If the printer has a density control, set it to 'blackest'. Even the best laser printers don't generally cover large areas well, but this isn't usually a problem as long as fine tracks are solid. Note that the blackness of the printing on paper doesn't always mean a good opaque result on tracing paper so always check with tracing paper if you're buying a printer for PCB work. When using tracing paper or drafting film, always use manual paper feed, and set the straightest possible paper output path, to keep the artwork as flat as possible and minimise jamming. For small PCBs, remember you can usually save paper by cutting the sheet in half, you may need to specify a vertical offset in your PCB software to make it print on the right part of the page.

[duncan303]

Hi Jonewoo,

I would add that a laser does not replicate accurately due to the way in which the laser printers work, one is liable to notice "bands" of distortion aligned down the printing process. Noticeable if one prints an image at 90deg to another and overlays them on paper.
This may cause an issue depends on requirements, but I would always go for an ink jet printing in photo mode using paper treated with highly absorbent seaweed.

Basis test is pick up image and if you can see the sun through the ink then............



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[The Master]

Ive been using the borrowed lazerjet. Its giving much better results than anything i tried on an inkjet. I have been using special PCB paper for both printers and the lazerjet is quite old but its still doing a better job.

Ive also changed the developer/water ratio and started using the orange acid. these have helped improve the PCBs too