plugwash wrote: ↑
Sun Nov 03, 2019 5:59 am
Heck 58mil pads with 6mil traces would give you three traces between pads and would probably be fine on a modern PCB process, though I wouldn't do it unless I really had to.
Yeah, that is really stretching it.
II have never seen a (dual layer) PCB with 3 traces beween Pads, and even with just two traces pads tend to become uncomfortabliy small if you just use round ones.
In a multi layer (say 4 layer) board the pads in the inner layers have different rules, and can be much smaller, its much easier to route three traces between pads on inner layers.
Most PCB manufacturiers have strict rules for the minimum amount of metal (“flesh”) in the ring of a pad, and an 58 mil pad really doesnt have enough “flesh” if you keep the hole 35 mil. And you can’t make the hole much smaller than 35 mil, or leads and pins won’t fit, not to mention if you want to desolder components soldered into such small pads it becomes very hard to do, without damaging the pads.
Its just that looking at the current ratsnest I can see many instances where having just one wire between two pads simply isn't enough, and I don't expect I can update the routing enough to solve that, So I am forced to use this solution.