Footprints naming convention: IPC-7351 vs. Expert - PCB Libraries
Key changes include moving from a specifying rounded rectangle pad shapes with corner radii,
: Recommended using rounded rectangles instead of standard rectangles or oblong shapes to improve solder paste release and consistency. Contour Courtyards ipc-7351c pdf
The "C" revision introduced several major shifts in PCB design philosophy: Proportional Pad Stacks
: Replaced the older "3-tier" pad stack concept with a system that scales annular rings proportionally based on hole diameters. Rounded Rectangle Pads Footprints naming convention: IPC-7351 vs
The development of IPC-7351C was famously stalled and eventually scrapped in favor of starting fresh with
to include more data points like thermal tab sizes and terminal lead dimensions to prevent duplicate names. PCB Libraries Current Status: IPC-7351B vs. IPC-7352 IPC-7351B (Current Standard) IPC-7352 (Newest Guideline) Release Date February 2023 Technology 100% Surface Mount (SMD) SMD + Through-hole (THT) Document Type Official Standard Pad System 3-Tier Fixed (Most, Nominal, Least) Proportional Pad Stacks Rounded Rectangle Pads The development of IPC-7351C was
version, with the intended "C" updates largely absorbed into the newer IPC-7352 Guideline Overview of IPC-7351C