METHOD AND APPARATUS FOR GROUNDING A HEAT SINK IN THERMAL CONTACT WITH AN ELECTRONIC COMPONENT USING A GROUNDING SPRING HAVING MULTIPLE-JOINTED FINGERS

摘要

A grounding spring for electromagnetic interference (EMI) suppression is interposed between a heat sink and a printed circuit board (PCB) . The grounding spring comprises a conductive material having an opening formed at its base through which the heat sink makes thermal contact with an electronic module mounted on the PCB. The base makes electrical contact with a peripheral surface of the heat sink, and multiple- jointed spring fingers extend from the base to make electrical contact with conductive pads on the PCB. During compression, the movement of each spring finger's tip is substantially limited to the z-axis. Accordingly, the final installed location of the tip can be precisely controlled even when the grounding spring must accommodate a wide variety of installed heights of the heat sink relative to the PCB. Preferably, the spring fingers terminate with a concave tip that is less susceptible to sliding off the conductive pads.