I work in a material and failure analysis lab for Lockheed Martin. We have a set of PCBs that are failing after hand soldering operations. Similar hand soldering operations on other boards are successful. Cross sections of the failed areas shows pad lifting and a seperation of the barrel and innerconnection on layer 5. The board is a 6 layer glass epoxy GFG board. Suspect problem with board material between layers 5 & 6. Looking for information on types of tests to run, printed material relating to testing PCBs, or other sources for information. Thank You. Russ Salvo