When a manufacturer or engineer downloads the IPC-4556 PDF, they are scrutinizing three primary physical characteristics: Thickness, Porosity, and Adhesion.
The electroless nickel layer acts as a diffusion barrier between the copper and the gold. ipc-4556 pdf
If you are downloading the , these are the critical tables and limits you will look for. Note that these values are based on the latest revision (A or B, depending on your access). When a manufacturer or engineer downloads the IPC-4556
The IPC-4556 PDF addresses the rigorous demands of gold and aluminum wire bonding, which require a different gold crystal structure and thickness compared to standard soldering surfaces. If your design involves wire bonding, adhering to IPC-4552 may result in wire lift-offs, whereas IPC-4556 ensures the surface energy and morphology are suitable for reliable bonding. Note that these values are based on the
The document outlines visual acceptance criteria. The gold surface should be smooth, uniform, and free of defects such as:
