Brittle copper on the Surface: As several have mentioned: if you have brittle copper on the surface, what happens in the holes; probably a lot more and the strain is a heck of lot greater in the holes. Suggest you test you copper plating per IPC-RB-276 par. 3..5..8.3 which specifies test method IPC-TM-650 Method 2.4.18. Brittle is inherent when there is either organic and/or metallic contamination of the plating solution and it does not take very much, a few parts per billion of certain compounds or elements will make the ductility go south. Usual treatment is a peroxide/carbon treatment or dummying at a low current density to remove unwanted metals, or send a sample to you chemical supplier for a better analysis. You might pull of a conductor of of a board and crease with the plating out and see what it does. Some people use a bend test in place of the tensile/elongation test, but the number of bends before breaking must be quantified with clad copper thickness, overplate thickness and other conditions. Suggest yoou attack contamination in the copper bath . *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * ***************************************************************************