Heat spreader, electronic package including the heat spreader, and methods of manufacturing the heat spreader

A heat spreader, method of making the heat spreader, and incorporation of the heat spreader in an assembly such as an electronic assembly, are disclosed. The heat spreader includes a matrix material, which has incorporated therein carbon nanotubes and/or thermal pyrolytic graphite flakes. The carbon nanotubes and/or thermal pyrolytic graphite flakes are situated between a first surface and a second surface of the heat spreader, to transfer heat from a heat source (e.g., an electronic component) adjacent the first surface to, e.g., a heat sink adjacent the second surface when the heat spreader is incorporated in the assembly. The first surface has a smaller surface area than that of the second surface. Desirably, the carbon nanotubes and/or thermal pyrolytic graphite flakes are aligned extending between the first and second surfaces, and spread out in a direction from the first surface to the second surface, to provide more effective heat transfer and uniform spreading of the heat. The matrix material can be a metal or plastic, and can be compliant, flexible and soft to provide better thermal contact of the heat spreader with the electronic component and heat sink, even if surfaces are uneven, and to provide protection for fragile electronic components against shock and vibration and during structural loading.