| https://www.eptac.com/faqs/ask-helena-leo/ask/copper-elongation-and-tensile-strength-requirements
. The place to find that information in IPC documents is in IPC-4101, Specification for Base Materials and Rigid and Multilayer Printed Boards
Heller Industries Inc. | https://hellerindustries.com/wp-content/uploads/2018/07/last-will-of-bga-void.pdf
BGA288 19x19 mm 1.0 mm A-CABGA288- .8mm-19mm- DC Test Vehicle The test board was 2.18mm (86 mil) thick with 14 dummy inner layers. The board was constructed using FR-4 material in accordance with IPC-4101/126 with an electroless nickel/immersion gold (ENIG