A novel cooling structure for electronic package

As electronic products tend to higher density and higher power, thermal management plays a key role in electronic package design, especially in CPU, ASIC and System-in-Package (SiP). The root cause of many product failures can be traced back to heat management, so reducing chip working temperature and improving device thermal performance are necessary requirements. We report on the design and implementation of a novel cooling structure for electronic packages, called the ´bottom heat spreader´. The bottom heat spreader has two main features. The first is that heat is removed from the side of the chip where heat is generated by transistor switching without relying solely on thermal conduction through the thickness of the die. To this end, an additional heat spreader is placed at the bottom of the die. The other feature is that the stiffener ring that provides a heat conduction path to the heat sink is a good thermal conductor. This structure provides another path of thermal conduction path to improve die cooling. Simulation reuslts indicate that the overall thermal resistance with the bottom heat spreader in place is 13.24% lower than the same sturcture without the bottom heat spreader. The bottom heat spreader is compatible with other cooling structure for added cooling performance.