PCB Milling Eagle Part Library

So, it’s occurred to me since I started milling PCBs that you can’t just design your circuit the same as you would if you were going to send it to a board house.

For example, through hole components. Say I want my lead to pass through the top layer and solder to a pad on the bottom layer. To accomplish that, I drill a hole and mill the trace for the pad on the underside. Pretty straight forward, right? NO. The top layer can’t be left the way it is. With just a hole drilled, there’s a good chance your part’s lead will act like a VIA and connect the bottom and top layers where the hole was drilled. To prevent this, you have to mill a circular trace around the hole on the top layer to isolate the copper and prevent a short.

So, I’ve been thinking about best practices for milling PCBs and I can’t find any part libraries for milled boards.


Your correct about isolating the opposite side.
you can make it a cut out using the layers for your circuit design.
Also you do not want to have any through hole components with isolated vias as they can short if the bend of led is soldered in and it will bridge. What you need to do is figure out your layout to prevent these. Place your traces where they need to go to avoid any issues.