Design Of Automobile Headlamp Based On LED Module Without Substrate

LED has become the first choice for the new generation of automobile headlamp because of its advantages such as long life,low energy consumption and quick start time.However,due to the limitation of packaging technology,the LED emission rate is not high,and the rest of the energy is dissipated in the form of heat energy.The size of chip is very small,and the chip is a direct beaeer of this energy,so the heat flux is very high and it is easy to produce heat accumulation.At the same time,LED headlamp works in a high temperature environment,the heat is more difficult to dissipate.Therefore,this paper focuses on the research of the LED headlamp cooling problem:Firstly,this paper analyzed two passive heat dissipation schemes,and put forward the method of heat dissipation of LED headlamp from two aspects of heat conduction and heat dissipation.In this paper,we explained why flip and normal LED junction temperature was different in theoretical and simulation method.At the same time,the barrier effect of the insulating film on the heat flow was described,and the LED module with low thermal resistance has been proposed.Secondly,the design and research of the LED headlamp module were made,and we found that the thickness of the insulation film in the base had little effect on the chip junction temperature,while the width of the middle copper electrode and the height of the base had a greater impact.And the size of the base was determined: insulation film thickness was 0.1 mm,the width of middle copper electrode was 5 mm,the base height was 6.45 mm.In addition,the thermal resistance of the PN junction to the thermoelectric separation end was calculated,that was 0.916?/W.Thirdly,the structure parameters of sunflower radiator: the fin number,fin height,fin thickness of main radiator,the fin number of deputy and root thickness,were studied in the methods of orthogonal test and range analysis.By using the method of range analysis,the influence degrees of each factor on the volume and junction temperature were obtained.The size of the radiator was optimized by using the linear weighted model,and the fin efficiency was 95.27%.Finaly,the thermal resistance was measured,10.15 ?/W,and chip junction temperature was caulated by the combination of LED pin temperature with resistance 10.15?/W.And we put forward that: the limit of LED headlamp safety power is about 26.11 W.