is a standard developed by the Association Connecting Electronics Industries (IPC) titled “Generic Requirements for Surface Mount Design and Land Pattern Standard.” Released as a revision to the original IPC-7351, it provides a comprehensive, mathematical approach to designing land patterns (footprints) for Surface Mount Technology (SMT) components.
Common in chip components. When one pad is too small or too large relative to the other, surface tension pulls the component vertical. IPC-7351A’s symmetrical pad design eliminates this.
The standard defines the "courtyard," which is the minimum physical area required around a component to ensure electrical and mechanical clearance. This includes: ipc7351a
Virtually every professional PCB design tool supports IPC-7351A, either natively or through plugins:
Understanding this naming convention allows you to share libraries across teams and EDA tools without confusion. is a standard developed by the Association Connecting
The core innovation of IPC-7351A is its rejection of the "one-size-fits-all" footprint. Instead, it provides three distinct land pattern configurations for every component density level:
One of the most powerful contributions of IPC-7351A is the classification of land patterns into three "Density Levels." These levels allow designers to trade off board space against solder joint robustness. IPC-7351A’s symmetrical pad design eliminates this
That said, is still referenced in countless design rules documents, library naming conventions, and manufacturing agreements. Learning 7351A first gives you a foundation that translates directly to 7351B.
Disclaimer: Always consult the latest IPC standards (IPC-7352) for new designs and component types introduced after 2016.