Copper Pours and Keepouts

[Stephan]

A quick and simple question - After speaking to some people, it became apparent that some of them prefer keepouts underneath their components (especially passive devices). Why is this? To me it makes more sense to have a GND Plane underneath the component. The more uniform the pour the better. Since the current loops be smaller and high speed signals will travel exactly underneath their power tracks. Could shine some light on this for me?

Regards,
Stephan.

[randychase]

I think you statistically improve your producability by having less chance of metal shorts under the passive components. For example, I like to not have traces use the spaces between the pads of 0603s or 0805s, unless it is the last resort. If you develop a solder bridge under the part, it could be harder to see.

These are very small points, but the only thing I can think of that would explain a copper keepout.

I don't normally follow that guideline and do not build in keepouts under components.