Ipc4556 Pdf (2024)
IPC-4556 PDF: The Definitive Guide to ENEPIG PCB Surface Plating Standards
The update introduces higher expectations for nickel corrosion resistance.
The core function of the document is to provide standardized requirements that ensure ENEPIG performs reliably across various assembly technologies. ipc4556 pdf
| Feature | IPC-4552 (ENIG) | IPC-4556 (ENEPIG) | | :--- | :--- | :--- | | | Electroless Nickel / Immersion Gold (2 layers) | EN + EP + IG (3 layers) | | Wire Bonding | Primarily Aluminum wire bonding | Gold, Aluminum, and Copper wire bonding | | Key Weakness | Susceptible to "black pad" corrosion after soldering | Palladium layer prevents hyper-corrosion, offering higher reliability | | Gold Thickness | Minimum of 0.05 µm (with a maximum added in rev. A) | Tighter range: 0.03 - 0.07 µm |
Authorized resellers of IPC documents.
Designers should specifically reference to ensure your PCB layout matches manufacturing capability.
Released by the Association Connecting Electronics Industries (IPC), this document establishes the requirements for the qualification and performance of heavy copper circuitry. Unlike standard printed circuit boards (PCBs) that typically use copper foils of 0.5 oz to 2 oz, "Heavy Copper" refers to conductors with thicknesses of 3 oz per square foot (approx. 105 µm) or greater. IPC-4556 PDF: The Definitive Guide to ENEPIG PCB
High-power COB (Chip-on-Board) LEDs require thick copper for heat spreading. IPC-4556 defines copper thickness that doubles as a thermal diffuser.
IPC-4556 is the globally recognized standard for the ENEPIG surface finish for printed circuit boards, providing crucial guidelines for achieving reliable contacts in high-reliability applications. First released in January 2013 and updated with Amendment 1 in 2016, it applies to a wide range of users, including chemical suppliers, PCB manufacturers, EMS providers, and OEMs, ensuring consistency across the supply chain. The "A" revision (IPC-4556A) was published in 2025, incorporating the latest industry advancements. A) | Tighter range: 0
The initial release established standard boundaries for ENEPIG processing. However, the 2016 Amendment 1 introduced an absolute cap of 0.070