"24V DC Cooling Fan" folded sheet metal heatsink fin array folded into shape, because of the folded sheet metal by welding solder and copper soldered to the bottom of the heat sink, resulting in additional heat at the interface resistance. Steps in the production increases, so that the cost of upgrading. The manufacture of small fin spacing is difficult point. Due to increased heat dissipation area, so good cooling efficiency. "24V DC Cooling Fan" Modified casting (Modified die-casting) heat sink is an extension of the traditional manufacturing methods such casting methods, the imprint will be quite thin fin array is first separated between phenomena of nature, and then fixed with clamps, so that the fins of the fin is fixed to the bottom of the bottom casting, and the formed fins. "24V DC Cooling Fan" eliminates the fin and the bottom of the thermal interface material, such a process can provide a high aspect ratio.