IPC 7351A

This popular document covers land pattern design for all types of passive and active components, including resistors, capacitors, MELFs, SSOPs, TSSOPs, QFPs, BGAs, QFNs and SONs. The standard provides printed board designers with an intelligent land pattern naming convention, zero component rotations for CAD systems, and three separate land pattern geometries for each component that allows the user to select a land pattern based on desired component density. Revision A now includes land pattern design guidance for lead free soldering processes, reflow cycle and profile requirements for components, and new component families such as numerous forms of chip array packages and “pull-back” QFN and SON devices. IPC-7351A includes both the standard and a IPC-7351A land pattern viewer from which to access component and land pattern dimensional data.