I've got a doozy of a situation:
On this circuit I had made, I routed an IRL530N D2Pak transistor with Source and Gate switched....the large heat pad should be the gate input, but instead I routed it to ground. Furthermore, I added 2 heatsink pads on either of the transistor, with traces from those pads going to the Gate pad.
To compound the issue, I added 11 small copper-plated through-holes on the Gate pad that runs through the board to the ground plane on the bottom side. Unfortunately (for this situation), I added 2 inner layers (power and ground); those through-holes are part of the inner ground plane as well.
Here's a couple options I was going to take, all of which could possibly damage the board:
1) Heating issues may arise
- a) flip the transistor 180 degrees
- b) cut the Drain pin off
- c) solder the Source pin to the square pad
- d) cut the traces going to the heatsink pads
- e) cut trace from the small right pad
- f) bridge connection between heatsink pads and the 2 small pads
- g) solder underneath of transistor (Gate) to 2 small pads (the left small pad will be the Gate trace
- g) wire the non-SMD Drain pin that I cut off to the resistor to bridge that connection
2) May cause a short somewhere or I may accidentally end up removing the entire square pad (this would be my first time running this kind of procedure)
- a) use a thin knife to cut around each hole (top and bottom of board) to break electrical connection
- b) remove the parts of the copper off the top of the board
- c) cut trace from small right pad, then wire it to ground
- d) wire the square pad (now the Gate) to the pin that used to be connected to the right small pad
- e) do nothing to the left small pad or the trace (would still be the correct route for the Drain)
3) Inner power and ground planes may short, or eventual re-soldering may flow through and come in contact with the inner planes
- a) drill through each of the 11 holes
- b) cut trace to right small pad, reroute to ground
- c) route square Gate pad to the pin originally routed to right small pad
So far that's what I'm thinking of doing...I don't have enough expertise (or even a minimal understanding) of the cause-and-effect risks involved, so any opinion or alternative solution would be greatly appreciated.
If the board is a goner, let me know too...I only purchased 3 for a relatively cheap price, so I'll take the hit if that's the case.