Heat sink retention apparatus

Abstract

A heat sink retention assembly including a spring, a spring retainer, and a spring displacement limiter. The spring retainer maintains the spring in a compressed state in which a contact portion of the spring applies a force to the heat sink. The compressed state is characterized by a predetermined spring displacement and exerted force. The spring displacement limiting mechanism prevents displacement of the compressed spring substantially beyond the predetermined spring displacement. The displacement limiting mechanism may comprise a separate component such as a spacer structure or may be integrated into the configuration of the spring itself. In one spacer structure embodiment, the spacer has a vertical dimension that is determined by the difference between the total spring displacement possible and the predetermined spring displacement required to deliver the predetermined force to the heat sink. When the spacer is placed between a bowed portion of the spring and the heat sink, it contacts both the spring and the heat sink when the spring is in the compressed state thereby preventing additional displacement. Alternatively, the spacer may be sized to leave a small gap between the spacer and the heatsink when the spring is in the compressed state to permit slight movement of the heatsink under mechanical shock.