Ipc-4556 Pdf |best|

The standard provides precise thickness requirements and performance criteria for the three metallic layers: Circuit Insight Electroless Nickel (EN):

The transition to lead-free electronics and high-density packaging has driven the adoption of Electroless Nickel/Electroless Palladium/Immersion Gold (ENEPIG) per the IPC-4556 standard. This paper examines the thickness requirements, performance benefits, and reliability under thermal stress compared to traditional finishes. ipc-4556 pdf

IPC-4556 relies on these test methods (mostly from IPC-TM-650): ipc-4556 pdf