How to retrace circuit boards and pcbs.

[albert001]

I'm looking for some more information and advice how to re-solder / re-trace circuit boards where lead free solder has microcracks due to age.

The problem is with an  VIC (vehicle information center) in an mid 90s vehicle, (comprised of two circuit boards). I'm told the solder used by the manufacture at the time  was a lead free solder and that with age eventually developed microcracks causing problems with the VIC.

There are people who have retraced the VIC boards to repair them and get them working again.  I think some have used a strong magnifying glass to locate microcracks in the solder.

I have a couple soldering irons. A Weller EC2002M  soldering station with temperature control and readout and an older Ungar soldering iron with many tips and various tips with heating elements, up to 1000 deg. F.

From what I understand prior to re-soldering your suppose to clean off any board coating around the area being resoldered . Both circuit boards have some kind of conformal coating.

I've never performed this sort of work on a pcb / circuit board before so am mostly guessing how to do it.

I'm thinking of starting by using knife tip trying to reflow some of the solder joint/connections.



I'm just looking for advice and the best approach to repair the two VIC circuit boards.

 

[David Hess]

I have manually solder reflowed boards a few times.  After removing any conformal coating and cleaning the board, I use solder wick and flux to remove the old solder from half of the connections to each part at a time and then resolder using my favorite tin-lead solder.