I have a PCB mounted to a chassis with 16 feedthrus, the feedthrus posts are soldered to plated thru-holes in the PCB. I would like to remove the PCB from the chassis, the problem is that I am unable to remove 100% of the solder from the plated thru-holes and I am unable to simultaneous heat all 16 points to try and remove the board while the solder is hot. The 16 posts are arranged in two identical groups of 8 with an identical outline.
I've tried to remove the solder from the thru-holes using solder wick and a vacuum solder-removal gun but a little solder is always left, this is probably due to the sizing of the holes which are only slightly bigger than the feedthru pin, 22 and 18 mils respectively.
One idea is to make a custom soldering iron tip that exactly matches the hole pattern so that all 16 holes can be heated simultaneously, then the board can be removed while the solder is liquid. I've never made a custom soldering tip before so this method has some inherent risks from the unknowns.
Any other suggestions for removing the PCB? Also, heating the whole assembly above 150°C is not desirable due to sensitive components that are mounted to the chassis on the other side.