Copyright © 2023 · All Rights Reserved
According to the standard, boards with an ENEPIG finish must maintain a minimum shelf life of 12 months under proper storage conditions, adhering to IPC-J-STD-003 Category 3. Versatility in Assembly
Offering low and consistent contact resistance for switches and connectors. Technical Specifications & Thickness Requirements IPC-4556 - Specification for Electroless Nickel
The primary, non-destructive method used to measure the thickness of the nickel, palladium, and gold layers. ipc4556 pdf
, "Specification for Electroless Nickel/Electroless Palladium/Immersion Gold (ENEPIG) Plating for Printed Circuit Boards," is the definitive industry standard for the ENEPIG surface finish. Released in 2013 and subsequently updated to the IPC-4556A revision , this document defines the quality requirements, deposit thicknesses, and testing protocols for ENEPIG-finished PCBs.
The standard defines the acceptable thickness, adhesion, porosity, and thermal reliability of plated copper used as a surface finish. Unlike standard electrolytic copper, "thick-film" copper under IPC-4556 typically ranges from or more, depending on the application class. According to the standard, boards with an ENEPIG
It supports both soldering and various types of wire bonding (Gold, Aluminum, and Copper), as well as press-fit applications.
In the rapidly evolving world of electronics manufacturing, reliability is the bedrock of success. As components become smaller and circuit boards more complex, the industry has turned to as a multi-functional surface finish. Central to the success of this technology is the IPC-4556 Specification , the definitive guide for implementing this tertiary layered finish. What is IPC-4556? Unlike standard electrolytic copper
Grain structure, nodular formation, and ductility are all defined. This is critical for wire bonding and soldering.
Heavy copper layers are heavy. This creates unique issues during the lamination process (pressing layers together with epoxy/prepreg). The standard outlines the peel strength requirements to ensure the heavy copper tracks do not lift off the substrate under thermal stress.
Deposited directly onto the activated copper. It serves as a robust diffusion barrier that prevents copper from interacting with upper layers and strengthens plated-through holes.