The little gerber viewer that could!
Of course I’m talking about gerbv! For those of you who don’t know, gerbv is a free Gerber or RS-274X viewer that comes from the gEDA Project. It’s free, it’s open source, it’s cross platform… (quick link to windows version download here) and that’s awesome.
So, why do you care? Well, if you are building your own circuits and want to get a PCB made then usually the format you’ll need to export your design into is a gerber. The reason you should grab gerbv is to double check for errors. When you design a PCB in your favorite circuit layout tool, whether it be Eagle, Altium, or my favorite DipTrace, you should double check for errors.
Your layout tool might have a built in gerber viewer like DipTrace does, but if there is a problem in the generation of the gerber, the viewer might have the same issue and appear as a non-issue. So, by using some other tool then the one that generated the gerber, you are improving the reliability that your gerber file was generated correctly and will not have any additional problems when the person you are sending it to, to manufacture the board, will have.
Another plus I’ve found to looking over your gerbers before sending them off is you might notice something that you didn’t in your layout editor. The gerber is pretty bare bones, it doesn’t have fancy highlighting of traces, sometimes you’ll have something on a layer that doesn’t get exported like the assembly layer. You’ll see it in your editor, and think it is part of the silk screen layer, but in fact it’s not! So by checking over each layer in an external gerber viewer, you’ll catch errors you might have normally missed.
Using gerbv is pretty straight forward: open all of your layers, choose colors and organize the stackup. There is a message box that will alert you if it detects any errors with your gerber or drill file. Once loaded, you can turn on and off layers individuallyand use some of the tools like the Measure Tool. Measuring is good, especially if you are doing your own paneling or your manufacturer requires the board to be within a certain size. Gerbv will also let you modify a gerber but it’s not very sophisticated in that realm. You can delete some objects that you might not have wanted, but you cannot add or undo anything.