Before you send your gerbers to the PCB house it is always a good idea to check them over, I use viewplot. The thing I would like to know is what are the common errors that can be picked up by viewing gerbers? So far I never found an error
In general we're just looking for really bad errors that happen with gerber exports. It's not an in-depth check, just a quick verification before committing to spending $25 on the PCB.
In general:
*missing pads (problems with the footprint, the solder pad is sometime buried by mask)
*drill problems (drills outside board or flipped)
*silk problems (CAM didn't export expected silkscreen layers)
It is just necessary to make sure they look right before making boards from them, like previewing a PDF from a word doc before sending it to the printer for 100 copies.
thanks
OK, related to this, I'm using the .cam file by Seeed, but v0.94 and v0.95 both have size issues with the drill file, it is waaay larger than my board. Anybody had this problem.
I use viewmate, now by pentalogix.
Like Ian said, it's mainly for double checking and finding any gross errors. Most of the work is done in the design package, but here are a few other points as well:
*Evaluating not only whether a silkscreen is present, but if it's legable (size, location, etc).
*For the more complicated footprints, its useful for evaluating exactly where masks are applied, as well as quickly seeing whether all of the vias on a board are tented or not.
*On output from older design packages, it was sometimes necessary to double check copper fills, but this generally isn't a problem with current ECAD packages.
*One last doublecheck to make sure soldermask is on the correct side for the correct component (PCB's that have components on both sides)
I don't look the Gerbers, nor do I examine the binaries from my compiler. I trust my tools.
[quote author="JuKu"]I don't look the Gerbers, nor do I examine the binaries from my compiler. I trust my tools.[/quote]
most of this stuff isn't so much about trusting the tool as it is double checking yourself (or whomever else made the footprints or CAM script you're using). we're all human and most of us make mistakes :)
I use http://www.FreeDFM.com/ (http://www.FreeDFM.com/) from the fine folks at Advanced Circuits < http://www.4pcb.com/ (http://www.4pcb.com/) >
Not only does FreeDFM.com provide you with image files showing what is in the Gerbers, it also reports the number of errors that were found. Of course, this really only applies for their design rules, but it's certainly better than nothing. It's not interactive like a Gerber viewer, but it's still a decent check that you didn't get some setting wrong.
[quote author="rsdio"]I use http://www.FreeDFM.com/ (http://www.FreeDFM.com/) from the fine folks at Advanced Circuits < http://www.4pcb.com/ (http://www.4pcb.com/) >[/quote]
I do as well.
At work we use Advanced Circuits exclusively for all PCB's. I heartily recommend them ( as I have before elsewhere) if you need to make sure something is done "right". They're approachable to the point where you can give them a call and speak with an engineer to discuss the best way of accomplishing specific requirements, how exactly the boards are made, etc. This has come in really handy when making design trade-off's or getting PCB's made that might be a bit on the strange side.
[quote author="tayken"]OK, related to this, I'm using the .cam file by Seeed, but v0.94 and v0.95 both have size issues with the drill file, it is waaay larger than my board. Anybody had this problem.[/quote]
I have the same issue.M
http://http://www.gerber-viewer.com/default.aspx
is an online gerber viewer that works well for me. I use Cadsoft Eagle 6.0.0 on windows xp, with the sparkfun cam processor for generating the gerbers.
I've tried Viewplot 1.5, it is just a pain, and it has trouble understanding the drill file format.
Another tool I've heard a lot about is DFM Now! It's a free Gerber Viewer and has all the bells and whistles. But it does require Internet connection.
Hope this is helpful.
I use the opensource viewer gerbv. Its a great little viewer that is available for windows and linux.