The IPC-7351C standard was proposed as a complete rewrite of IPC-7351B, introducing proportional pad stacks, rounded rectangle pads, and contour courtyards. After the passing of key architect Dieter Bergman, the draft was ultimately scrapped in favor of the newer IPC-7352 standard. For further discussion on the draft, visit the PCB Libraries Forum . Draft IPC-7351C - PCB Libraries Forum
This is the most valuable part of the standard for layout engineers. Before 7351, everyone used generic "big pads." Now, you choose a density level based on your production volume and environment. ipc-7351c pdf
Large pads for high-reliability applications (military/medical) where rework and hand-soldering are common. The IPC-7351C standard was proposed as a complete
The IPC-7351C PDF is a widely used standard in the electronics industry, specifically in the realm of surface mount technology (SMT) and printed circuit board (PCB) design. Published by the Institute for Printed Circuits (IPC), a leading trade association in the electronics industry, this document provides guidelines and recommendations for the design and manufacturing of surface mount devices (SMDs) and their related PCB footprints. Draft IPC-7351C - PCB Libraries Forum Step 3: