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View Full Version : Cutting 1 oz. or 2 oz. Copper on Circuit Boards



Gary Gilbert
01-02-2007, 11:05 PM
I am in the process of consideration o purchasing either an Epilog or VersaLaser system.
Among the many thing I could forsee using would be simple circuit board prototype copper etching.

Circuit boards have 1 oz or 2 oz - I don't know what that would translate into thickness, however.

I can buy bare copper boards incredibly cheap, and would like to etch simple circuits by removing the copper I didn't want.

Does anyone have any experience with this?
What power level might be required? Speed?

Then, cutting the board through to remove sections - anyone done that?

Thanks!!!

Gary

Bill Cunningham
01-02-2007, 11:14 PM
I'm a Ham Radio Operator, (VE3HHW) and thought of this a few years back, but nope, "my" laser won't touch it.. I don't know if someone with a 60 or 100 watt machine can do it, but I have my doubts... What you could do, is paint it black, use the laser to etch off the paint to expose the copper to be removed, then use your normal etching soloution to etch the exposed copper away. It would sure beat putting a photoresist on, and making a negative..

John LeBlanc
01-02-2007, 11:26 PM
I think you'll find that a mini CNC machine is a better choice overall. Google a guy named John Kleinbauer and CNC and you'll find a web site with DIY plans and plenty of information to consider. (Granted, most people aren't interested in making their own CNC machine, but the web site provides plenty of easy-to-understand information about what it can do and what to look for.)

Good luck to you. The last PCB I made I did the old fashioned way -- and that was a long, long time ago!

John

Dave Jones
01-03-2007, 2:39 AM
These lasers won't cut copper or fiberglass. You need a YAG or very high power CO2.

Cheaper to use a place like Sierra Proto Express. Three double sided boards in a week for under $100.

Gary Gilbert
01-03-2007, 10:12 AM
Thanks, guys.

Dave - yes, I'm very familiar with proto houses. I design cricuit boards.
But sometimes, I have a need to just make something somewhat simple in a few hours or days and was just curious if it would work.

The other problem is copper diffuses heat so well that I would imagine it would be a problem.

Oh well . . .

Dave Jones
01-03-2007, 12:52 PM
As Bill points out you could paint the copper and engrave off the paint, then throw it in a bucket of acid.

I design PCBs too. That's why I mentioned Sierra. They're about as cheap as they come for a couple of protos. Plus you get plated thru holes, which you couldn't do even if you had a laser that cuts copper.

Dave Fifield
01-03-2007, 4:58 PM
Dave - thanks for the tip about Sierra. I have used AP Circuits in Canada for years for my prototype boards, but these guys sound cheaper! I'll check them out. FWIW, I use a local board house (Bay Area Circuits) for my production runs.

Bill - I'm AD6A, nice to make your acquaintance.

Cheers es 73,

Bill Cunningham
01-03-2007, 5:31 PM
Dave - thanks for the tip about Sierra. I have used AP Circuits in Canada for years for my prototype boards, but these guys sound cheaper! I'll check them out. FWIW, I use a local board house (Bay Area Circuits) for my production runs.

Bill - I'm AD6A, nice to make your acquaintance.

Cheers es 73,

Had a feeling you were ham..hi..

Dave Jones
01-03-2007, 9:44 PM
Dave, be aware that part of the reason that Sierra is so cheap is it is a process they call "no-touch". It's normal PCB production, but it's garbage in - garbage out as far as your artwork. In other words, they don't measure widths or anything about the artwork you send, and won't call you if they spot a potential mistake. They run the art as you send it. If the board is no good because of artwork errors, then you eat the cost of the board. As long as you know what you are doing, and double check everything you send them, then you get back beautiful boards. Of course it they make a mistake, they will make good on it, but "no touch" means they won't interact with you about any problems with your art. They just load the art and make the boards without checking it for design errors.

Dave Fifield
01-04-2007, 1:07 AM
Dave - Thanks! That's the same policy as the AP Circuits people. I have only screwed up one set of boards ever (touch wood it won't ever happen again). When I have finished up the board design and outputted the gerber files, I use GC Prevue (a freebie gerber viewer) to double check that the gerber files will actually produce the board I want.

What I'd really like is a cheap 4 and 6 layer PCB proto service. Do you know of a good one? The best deal I have for multi-layer boards right now is with BA Circuits, but it ain't cheap!

Cheers,

Dave Jones
01-04-2007, 5:05 PM
For 4 layers, the same people www.protoexpress.com $153 plus shipping gets you three 4 layer boards with the same 4 day turnaround.

I forgot to mention that there are some limitations in their no-touch process, such as boards must be rectangular, no internal routes, 1/16" FR-4, 1 oz copper, green mask, white silkscreen, .006" min traces, .015" min hole size, etc... Specs can be seen on their site. if you have really special needs, you have to use the regular process.

I've had some production boards done at Advanced Circuits www.4pcb.com and they do have deals on prototype runs. You might try their online calculator to see how they stack up for 6 layer protos. I've never done those there, so don't know how they would compare to who you use now.