The design of all heat sinks of LED lighting lamps(2)

Time : Jan 07 2015Source :analogtechnologies Author : LED Related Products Click :
There are many kinds of heat sinks. In the view of manufacture, air cooled heat sinks can be divided into nano imprint lithography fins, extrusion heat sinks, casting heat sinks, folding heat sinks, improved casting heat sinks, forging heat sinks, cutting heat sinks, mechanical processing heat sinks and so on.
The size and thickness of heat sinks can directly affect the effective radiating area and heal removal capability. Good heat sinks should be greater than the contact surface, and have a radiating area as much as possible. The materials of the heat dissipation pad are also a kind of excellent materials. It combined with heat sinks can improve the heat radiating effect. Envelope volume refers to the volume occupied by heat sinks. If the heating power is large, the required heat sink area will be big. The preliminary design of heat sinks is based on envelope volume, and then the detail design will be considered. Heating wattage and envelope volume have the following formula:
LogV=1.4*logW-0.8(Min 1.5cm3)
In order to increase the fin efficiency which has a great influence on the thickness of the bottom of heat sinks, the bottom must be thick enough to make the hot transfer to all fins smoothly. And that can make all fins have the best utilization efficiency. If the bottom is too thick, it can cause the waste of materials and the heat accumulation, and also can reduce the heat conducting ability. The good design of the bottom thickness demand that the thickness of the heat source part should become thin in the part of edge. So it can make heat sink absorb enough heat by the heat source part and then it can quickly transfer the heat to the surrounding part. Radiating wattage and the thickness of the bottom have the following formula: t=7*logW-6(Min, 2mm)
The heat sink surface which is took acid aluminum processing, can increase the heat radiation performance and also increase the heat radiation effect. In general, exterior color is white or black. Convex surface can increase the heat dissipation area, but in the natural convection suasion, it may block the air flow and reduce the efficiency.
The above design is for your reference only. The actual heat sink design needs to consider the device and environment cooperation. Especially the design of high performance heat sink is required with the experimental proof and computer simulation. At present, the heat sink design has tended to limit, and air cooling mode can meet the requirements of the heat dissipation of high power LED. So the heat sink design should combine with characteristics of the power numbers of the LED, and that can make the design more diversified. In any case, the heat sinks are still the most common way of radiating. *The good design of heat sinks can improve the LED.