Electronic – Increase incorrect thru-hole size by hand on PCB


I recently ordered a PCB and on one component footprint I accidentally set the solder pad size to what should have been the hole size (diameter) for a thru-hole component.

The difference is about 0.5mm / 20mil. The component is a fuse holder with two pins per terminal which I will use with a 10amp fuse (so roughly 5amps will be carried by each pin):

fuse holder

In order to do some testing on this board while I wait for a re-order, I am wondering about a temporary fix. Here are my questions:

  • Can I use a drill to increase the size of the holes?
  • Do I need to do anything to the hole after increasing the size in order to ensure a good connection?

Best Answer

If you the board is only two layers, and assuming you have clearance from other traces, you can drill out the plated-through holes. You'll have to make sure there is enough trace left to connect to, and you'll need to scrape the solder mask off of these traces.

This will also disconnect the top and bottom layers of your board in this location, so you may need to solder your fuse holder to both sides, or simply use a small piece of wire through the hole to connect them again.

If your board has internal layers then you probably shouldn't try. You may expose the inner layers and create shorts.

Upon reflection, I would be very hesitant to do this with 10A fuse holders. Solder isn't as conductive as copper. Perhaps you could expose the traces (remove the solder mask) and then solder appropriate wire from the trace to the fuse holder.

Or, for the easiest solution, do what @DerStrom8 suggested :)