IPC-4556 Handbook — Practical Guide for Engineers and Technicians

2. Immersion Gold Thickness

What is IPC-4556?

Who Uses IPC-4556?

Certificate of Compliance (CoC)

Include a clause in your supplier quality agreement mandating that the fabricator provide a referencing IPC-4556, along with cross-section photos showing measured nickel and gold thicknesses.

5. Solderability & Wire Bonding Tests

• Title: IPC 4556 — [specify exact standard name if known]
• Purpose: (Briefly state the standard’s focus—e.g., component footprint guidelines, inspection criteria, test method.)
• Where to find it: Check the official IPC standards store or your organization's standards library.
• Tip: If you need a downloadable PDF and don't have access, ask your procurement or standards librarian for a licensed copy.

Prior to IPC-4556, many manufacturers used generic or proprietary ENIG processes, leading to issues like "black pad" (hyper-corrosion of nickel) and inconsistent solder wetting. This standard provides a rigorous set of controls to eliminate those failures.