Ipc4556 Pdf May 2026
The Quest for the Perfect Solder
under proper storage, significantly longer than alternatives like immersion tin. Recent Developments: IPC-4556A IPC-4556 - Specification for Electroless Nickel
4. Surface Roughness & Planarity
- Electroless Nickel (Ni): This acts as a barrier layer to prevent the diffusion of copper into the final finish. It also provides a hard, planar surface.
- Immersion Palladium (Pd): This is the distinguishing layer. Palladium acts as a protective barrier for the nickel and provides an ideal surface for both soldering and wire bonding. It prevents the "black nickel" phenomenon often associated with standard ENIG processes.
- Immersion Gold (Au): A very thin layer of gold protects the palladium from oxidation and provides a contact surface for touch pads or wire bonding.
IPC-4556A (released June 2025) is the industry standard for Electroless Nickel/Electroless Palladium/Immersion Gold (ENEPIG) plating, defining requirements for soldering and wire bonding reliability . The specification outlines precise thickness ranges to prevent nickel oxidation ("black pad") and support universal assembly, including lead-free, tin-lead, and gold wire bonding . Purchase the official standard via the Accuris Standards Store at Accuris . IPC 4556A - Accuris Standards Store ipc4556 pdf
Given the legal and technical risks of counterfeit or outdated copies, here are the legitimate ways to access the document: The Quest for the Perfect Solder under proper
Lamination and thermal processes
Electroless Palladium:
in). Acts as a diffusion barrier between copper and surface layers. 0.05 – 0.15 m (2.0 – 12.0 Electroless Nickel (Ni): This acts as a barrier
