Design and optimization of horizontally-located plate fin heat sink for high power LED street lamps

When junction temperatures of the light emitting diode (LED) chips packaged inside LED lamps exceed their maximal limits, the optical extraction and the reliability/durability of the LED lamps will be jeopardized, therefore, thermal management is very important for high power LED street lamps. In this research, a design and optimization method of horizontally-located plate fin heat sink was presented to improve the heat dissipation of high power LED street lamps. To prove the feasibility of the present design and optimization method, a 112-W LED street lamp was co-designed by concurrent engineering of optical, thermal, and stress requirements. The engineering prototypes were manufactured and experimentally investigated. The experimental results demonstrated that the maximal heat sink temperature remained to be stable at 45degC when the ambient temperature was 25degC, the maximal temperature difference between steady state temperature and environment temperature for the heat sink was less than 21degC. Comparing the results achieved by the design with the ones by the experiment, it is found that the design and optimization method is feasible and works well for realizing the horizontally-located heat sink of such kind of high power LED street lamp.