A number of components I've come across lately (DC motor controller chips, ESD protection devices, for example) have a thermal or ground pad underneath the chip. This requires that a large pad be included in the footprint, and the usual recommendation is that several vias are used in this pad to connect it to the ground layer. This is also part of the thermal management scheme.
For example, if you look at page 10 of the datasheet for the Allegro A4983, it describes how to lay out the board. It shows 9 vias in the under-chip pad used to aid in solder flow and heat transfer. My first thought for how to do this in KiCad was to define a bunch of vias on the board. My second thought was to change the module so that the large pad was actually several small pads butt up against each other, tiled together to make one large pad, and have each pad be a through-hole style pad with a very narrow drill. Is there a better approach or feature I've missed? Thanks. --Jim
