I have some projects I'm working on, that I would eventually like to have designed on pcb software, so I can send designs to a manufacturer in gerber format (right?) Does anyone have recommendations about how to go about getting ready for this? I was thinking of making some extremely simple circuits, and having a manufacturer print a circuit board as simple as just a power connection to connect an LED to, or similar, and only stepping up what I designs when I'm sure that what I think will be created is what really will be created. Would a manufacturer find this a waste of time? Is there some other way to double check designs so that I don't have to pay to have something manufactured that I'll probably have no use for? i.e. can I send gerber files to some forum willing to analyze them and answer questions I have, or send a gerber file to a simulator?
"Dustin Robert Kick" wrote in news: snipped-for-privacy@j27g2000cwj.googlegroups.com:
If you're worried about board quality, find a fairly simple circuit that represents what you want to have made, and ask the manufacturer if they'd be willing to make a sample board. The worst that should happen is that they say "no."
As for the formats manufacturers want, you'll have to ask. If it's a fairly standard format, I'd expect a manufacturer to accept it.
If you want a board made here and there, you might consider getting a PCB etching kit from Radio Shack. It somes with everything you need to make a big mess, plus most the stuff you need to make a printed circuit board. (The 1/16" drill bit is way too big. You need something like a #60 bit, available at your local hobby shop. [Aside: I usually buy from the hobby shop rather than ordering something online because I like being able to stop in for a drill bit, can of paint, whatever and get back to my project.])
Puckdropper
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If you only wnat one or two boards of a certain small design usually the best way to go about it is to etch your own board using some of the various methods out there. Most PCB fabricators will charge you booku bucks to build just one or two boards. All the manufactures do (unless they offer testing as a service) is take the gerber file and feed it into the PCB machine to make the board exactly how it's described in the gerber file. If they offer consultation or if you try to do something that is beyond their machining ability they will let you know and have you submit another file but mostly they just make what you send them. :\\
You are correct, you normally send designs in Gerber format. Also, most of the PCB software I have used has electronics rules checks and design rules checks to make sure the board is at least sound be design. It might not do what you want it to, but it should manufactured correctly.
I've just recently gotten into making my own boards, and it's coming along nicely. My method is to use the free layout software Eagle
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to design my schematic and board, then laser print the board onto high gloss paper, iron the paper (toner, really) onto a copper clad board and then etch with ferric chloride.
There are a lot of variables that go into it, and I've messed up as many boards as I've made good but that has been because of experimenting with different line widths and pads and such.
One of the most critical things I've found is the type of paper you print onto. I've found "HP Photo Paper" with the following labellings to be very good: Laser, Glossy, 8.5x11", 7.5 mil, 58 lb, 97 brightness, 100 sheets. I got it at Office Max for I think around $10.
There's a billion sites on the net that detail this method of PCB manufacture, just search for "PCB laser print" or some such.
Now, while this method works find for boards with low part density and large line widths, the ideal (home brew) method is with photo etching where you use pre-sensitized boards, transparencies for your artwork and UV illumination to expose the board. I am in the process of gathering the tools to try this method now.
I found the book "Build Your Own Printed Circuit Board" by Al Williams (Tab Electronics) to be pretty useful for learning the basics of Eagle and home PCB manufacture. After that it's a matter of honing your methods and learning from the Internet.
Finally, if you would prefer to spend a little cash but get professional boards, check out
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and
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Both have free CAD software and you can send your design right from the software and have boards in your mailbox a few days later. ExpressPCB even has a "MiniBoard service" where you can get three 2.5x3.8" double sided boards for $51. It's a great deal, and you don't have to worry about a manufacturer laughing at you for testing simple designs :)
If you'd like to see a board I recently made using the home brew process, check out:
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It's the first I ever made, and it works great. It's a simple AVR breakout board for prototyping microcontroller programs.
And here's a few more handy links: Web-Tronics - Good source of PCB supplies
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Drill Bit City - Great source of cheap, tiny drill bits
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BatchPCB - Very cheap boards but long wait time. They batch their orders to China. They also have a design rule checking system. You can upload your design for free and it will email you to tell you if it's sound.
The final steps depend on the manufacturer, but basically, you design the board in your favorite EDA program (mine is gEDA), have it export gerbers, and send them off to the fab via the web or email.
They don't care, but it gets expensive when you do it that way. Check out
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they're geared towards one-off tiny boards, although you'll have to wait a while for them to come back.
You can make it at home with toner transfer or photoplot techniques.
Design something moderately complex, useful or not, mixed surface mount and thru-hole, and have a few proper plated-through, solder-masked, silkscreened boards made. Assemble one. You'll learn a lot.
Look in the backs of the professional (and free) electronics mags... EDN, Electronics Design, EE Times. There are tons of ads for cheap PC boards, with introductory offers. You should be able to get a few
2-layer boards for around $60.
Don't mess with the ferric chloride thing yourself.
Download a free Gerber viewer to verify the output is what you expect.
I just did a toner transfer board with some 0603 parts and 10/10 rules. I'm sure people have done 8/8 with a good laser printer and some care. Going much below that requires some skill even using a board house.
I can't really recommend this to the OP, because a large part of the learning curve is the software. When you venture outside the world of LEDs driven by 555 timers, the first step in board layout is making your own symbols and board elements. If you learn to do this with gerber- capable software like Eagle, you can etch boards yourself or use almost any fab house. As the complexity of your work increases you can keep re-using parts and sub-circuits from old designs. If you start out in a proprietary CAD program, you will have to make a painful break at some point.
The deals in PCB manufacture depend heavily on board size, how many you need, how fast you need them and whether you want soldermask/silkscreen. That's not a bad deal for "bare" boards, but if you add silkscreen their prices aren't as competitive. batchpcb.com is great for small board sizes or low quantities, but their prices get silly if board area goes up, and it takes a long time. If you had a 60 sq in board they'd charge you $150 each, while a place like Sierra Proto Express would make you
*three**4 layer* boards for the same $150 and get them to you in 1/3rd the time. Then again, Sierra Proto Express is one of those places with a silly "no panelization" rule, so you're still better off with batchpcb if you wanted 60 1 sq in boards. You really have to shop each board order if you want the best deal.
One further comment about batchpcb -- the default gerber output from Eagle is slightly offset from (0,0) and batchpcb doesn't detect this (at least in the X direction) and will charge you for the unused space. Check out your gerbers in a good viewer and then use the DRC setup in Eagle to re-export the board with a small negative offset to compensate. I was going nuts trying to get a 1 sq in board down to 1 sq in by their DRC until I figured this out...
For simple projects (and not-so-simple, once you get the hang of it) you can easily make your own hand-drawn boards with a Sharpie marker, some ferric chloride etchant, a Dremel tool, and some dental burs. Full details at
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Best regards,
Bob Masta D A Q A R T A Data AcQuisition And Real-Time Analysis
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Scope, Spectrum, Spectrogram, Signal Generator Science with your sound card!
Open source software (Gratis and Libre): KiCAD gEDA
Freeware (Gratis only): TinyCAD
Usable (limited) demo: Cadsoft EAGLE NOTE: Recent heads-up-their-asses DRM measures by Cadsoft have made it VERY risky to re-use someone else's EAGLE-compatible component symbols.
Lock-in-ware (crippleware): ExpressPCB; PCB123; Pad2Pad These DO NOT produce Gerber files. The output from these apps is only useful when sent to the fab houses which distribute the "free" software. . .
Typically. Check with your fab house for other supported formats.
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Dustin Kick wrote: :Are there any books on pcb design/fabrication :that are particularly good that I should read?
FIrst, thanks for all the great responses, I've got a bunch of ideas how to procede now. Does anyone out there use the UNIX tool pcb maintained by Harry Eaton?
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This is the program that I'm trying to learn with, right now, on Mac OS X, through the fink package system. Is there a better Mac OS X compatible program that I should try?
A certain regular poster here is also one of the developers and project admins of pcb, so it's pretty likely he's used it. ;-)
Make up your own mind about better, as I haven't gotten around to designing anything in both programs yet, but in the tiny world of engineering software for OS X, I did find one other option : Look at Osmond. Free for designs up to 700 pins. Pay if you need to do more.
I have been using Eagle ( cadsoft ) for some years now. Works perfect under Linux. While my wife uses a MAC ( OSX ) i tried Eagle there. The program runs just fine but using it with the MAC-mouse is a curse.
This is propably true for more CAD programs. Does a 3-button mouse work under MAC ?
Yes. I don't know if it would work the way the program expected (you'd have to try it and see), but in general, a 3 button mouse does work, and the one button mouse can mimic more buttons by using option keys on the keyboard to "modify" the click.
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