How can I fix this 8 layers PCB board?

[Ricknolds]

How can I fixed this 8 layers pcb board?



This is 8-layers ENIG boards, D225 is PD95-21B(SMD Diode)， it should have been PTH, but forget to drill hole. can it be built a circuit bridege to fix it or there's better solutions?

 

[betwixt]

Re: How can I fixed this 8 layers pcb board?

You can't 'fix' the original problem because drilling the board will obviously cut through the surface and maybe other internal tracks. It may be possible to modify the board though.

I assume the diodes are LEDs and should be facing through the hole or you could just substitute an SMD device. Look at the PCB design file and see if any internal layers have tracks passing the hole position. If there are, note the places they reach the surface. Then drill a hole and bridge the break using fine wire between those surface points. You can easily link the track between D226 and D227 with a wire, the connection to D225 looks like it goes to a via, you might be able to scrape the resist and solder to the via pad but if there is a surface component nearby on the same node it might be easier to link to that instead.

The only other option is to glue an SMD LED on the other side and run wires to the original pads or nodes.

Brian.