RF POWER PACKAGE WITH A DUAL GROUND

摘要

An RF power transistor package is configured for mounting to a heat sink in a multi-layer pc board, and includes a direct top side electrical ground path from a transistor chip located atop a ceramic substrate to a mounting flange, without passing through the ceramic substrate by way of metal plating an outer surface of the ceramic substrate to electrically connect a top mounted metal lead to the flange. A direct ground path from the transistor chip to the mounting flange is also provided by way of plated via holes through the ceramic substrate. The top side ground path is also configured to connect with the middle ground reference layer of the multi-layer pc board when the mounting flange is secured to the heat sink, so that a unified ground potential is seen by the transistor at both the middle layer and heat sink. In this manner, the power transistor package is grounded at the same reference potential as other elements attached to the pc board, while still having the high performance characteristics provided by the ground path via holes.