Heat spreader with composite micro-structure

A heat spreader, comprising:

• a casing, having an inner surface, which comprises a vaporization area, a condensation area and a transportation area, and defining a sealed chamber therein;
• a micro-structure layer formed on the inner surface of the casing, the micro-structure layer comprising a first structure layer formed by at least one first metallic mesh and a second structure layer formed by at least one second metallic mesh, wherein meshes of the at least one second metallic mesh are smaller than meshes of the at least one first metallic mesh, whereby cavities of the second structure layer are smaller than cavities of the first structure layer;
• a support device disposed in the sealed chamber for supporting the casing;
• and
• a working fluid, being vaporized at the vaporization area and condensed at the condensation area to circulate from the condensation area to the vaporization area in the sealed chamber;
• wherein the at least one first metallic mesh forms the first structure layer on the inner surface and the at least one second metallic mesh forms the second structure layer being stacked onto the first structure layer and corresponding to the vaporization area through diffusion bonding that the working fluid can circulate within the micro-structure layer by capillarity.