Surface Mnt Gnd/pwr Routing

[BPOWERS]

I know this hard to beleive but as a company we basically are just getting into surface mnt design.(we design large power supplies and there hasnt been alot of smt comps for high power until now).Yes have done a few designs already and have worked out ok.My question though is what is best way to route GND and PWR traces? They are done upfront i know but does each pin go to a via and drop to a plane or do you hook up several gnd points together then drop down?Any info would be helpful for this scenario..thanks

[randychase]

It depends. If you have the room, it can be better to use one via per pin, or even multiple vias per pin. With larger power requirements, you have to be aware of the current ability of one via. Also you want to be careful with power traces to not overwhelm the pad. In other words, do not use a 50 mil trace on a 40 mil wide SM pad. It is better to use 2 or 3 skinnier traces (for fabrication/soldering).

Routing depends on your philosophy too. Often I find it okay to route a power or ground trace to multiple connections and then drop it to the plane. Normally, if there is a decoupling cap, you should drop it there, but there is some debate if that really makes a difference.