PCB Design Guidelines for High Power Dissipation Packages

This Application Note provides PCB design guidelines for high power dissipation packages that ensure adequate solder coverage and optimize heat transfer. As a general rule, high power dissipation packages can be defined as those that dissipate more than 1.5 W (note that this is not the same as the RF output power). Such packages are generally those with an exposed electrical/thermal ground pad, such as Multi-Chip Modules (MCMs), Quad Flat No-Leads (QFNs), etc. The amount of power dissipation depends on the RF output power and the Power-Added Efficiency (PAE). Power dissipation in the form of heat is the difference between the combined DC and RF input power, and the RF output power. Good heat sinking is absolutely essential to guarantee the long term reliability of these parts.