Assembly and PCB layout guidelines for QFN packages

The dual-row or multi-row QFN package is a near chip scale, plastic-encapsulated package with a copper leadframe substrate. The exposed die attach paddle on the bottom efficiently conducts heat to the PCB and provides a stable ground through down bonds or by electrical connections through conductive die attach material. The design of dual-row and multi-row QFN packages allows for flexibility and enhances electrical performance to very high-speed operating frequencies.

The dual-row or multi-row QFN package utilizes an interstitial lead design that results in a staggered lead arrangement. The inner row is offset 0.5mm, which results in a compact design that maximizes die size while not exceeding the surface mount technology (SMT) capability of a typical 0.5mm pitch SMT process.

Actel offers QFN packages in three configurations: QN180, QN132, and QN108. The package footprint and outlines are covered under JEDEC MO-247: Plastic Quad No-lead Staggered Multi-Row Packages (with Optional Thermal Enhancements) and JEDEC Design Guide 4.19: Quad No-lead Staggered Multi-Row Packages.

View the PDF document for more information.