IPC 7351B:2010-06-30

IPC-7351B includes both the standard and an IPC-7351B land pattern calculator on CD-ROM for accessing component and land pattern dimensional data.The calculator includes the document's mathematical algorithms so users can build a land pattern for a corresponding surface mount part quickly and accurately.The tool also allows for modification of dimensional attributes of IPC approved land patterns.This document covers land pattern design for all types of passive and active components, including resistors, capacitors, MELFs, SOPs, 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 allow the user to select a land pattern based on desired component density. Revision B now includes land pattern design guidance and rules for component families such as resistor array packages, aluminum electrolytic capacitors, column and land grid arrays, flat lead devices (SODFL and SOTFL) and dual flat no-lead (DFN) devices. The revision also discusses the usage of thermal tabs and provides a new padstack naming convention that addresses the shape and dimensions of lands on different layers of printed boards. Purchasers receive a copy of the IPC-7351 Footprint Expert developed by PCB Libraries. The IPC-7351B Footprint Expert tool enables users to instantly export land patterns to their preferred CAD format, such as Allegro, Board Station, Expedition, PADS, CADSTAR, OrCAD, Pantheon and P-CAD. 102 pages. Released June 2010. Included in IPC-C-103, IPC-C-105, IPC-C-106 and the IPC-C-1000 Collections.