At my workplace we have expensive PCBs that are used for testing. These PCBs have conductive pads which wear out by time since they come in contact with pogo pins. These boards operate at temperatures -45°C and 150°C. What is the best option for repairing these pads? We have already tried conductive ink (don't know the exact specifications since the label has faded), but it did not work as well as we expected (probably because it is not suitable for those temperature ranges). Are there any methods that we can apply to repair these? or any conductive ink that can handle those temperatures?
You could try 4 oz. copper strip using solder paste to reflow underneath to create new pads using a solder gun. It depends what contact resistance is needed. Conductive epoxy paste with 99% silver particles is available.
I doubt than any conductive ink will be anywhere near wear-resistant than PCB pads. At the same time, even the PCB pads turned out to be insufficiently wear-resistant, as the O.P.'s observations show.
If I were to repair/retrofit these pads, I would attach small (but fairly thick) metal disks on top of the pads.
If you want something more wear-resistant than copper, but still use your pogo pin connection, you can
- get new boards made with nickel/gold plating on the wear points
- replace the pogo pins with flathead ones to reduce damage
- solder a button of sheet metal onto each pad (try silver, you can get 90% silver sheet as jewelry-making supplies)
- look at the options for surface-mount test points