How do you determine the optimum inner and outer diameters for the lands and clearance areas for a padstack with thermal ties to the power or ground plane? A semi-newbie colleague asked me this today and I had to admit I didn't know. Every company I have done board layout for has their own standards, and there is wide variation in the sizes used. The spoke width for all, though, has been a consistent .015". The colleague I spoke of also looked claimed to have looked through the IPC specs, but found inconsistency there, as well. Any ideas? Jay DeKing