Research On Heat Sink Structure Design And It’s Heat Dissipation Performance For High-Power LED

LED light has been expected to demonstrate its superiority and good functional performance inthe field of lighting. LED light has great advantages over traditional light due to its high luminousefficiency (about100lm/W), long service life, low consumption, and high controllability. However,extrusion limits are examined in terms of heat dissipation issues for LED light. For example, thehigher power and integration could lead to a series of problems, i.e. Lumens depreciation, life andreliability reduction. In particular, poor heat dissipation is the main barrier for the required workinglife and reliability of LED light. In this paper, three fin sinks with different fin’s angles are designedand manufactured, and the best installation angle has been found; a new type copper heat resource isdesigned and applied, sinks assembled with copper flat or flat heat pipe are tested by a reliableexperiment system, related thermal characteristics have been acquired; a new type sink with verticalheat pipe is designed, and an optimized design method by simulation is explored, which can provide amodel for further experimental study. The major work and results are as follows:1. Three fin sinks with different fin’s angles are designed and manufactured, temperaturedifferences with surrounded air are analyzed by experiment and the influence of installation angle onheat dissipation performance is studied which can got the best installation angle; airflow between finswould be interference by different degree that proved by air flow theory and convection heat transfercoefficient calculated by simulation, when fin direction perpendicular to the horizontal, best heatdissipation would be caught due to the more smooth airflow and higher convection heat transfer.2. A reliable experiment system is established with a new type copper heat resource according toone-dimensional heat conduction theory，this system with the simple structure can replace the LEDchip array to generate heat, output heat flux preciously and reduce the error caused by change in theequipment.3. Three sinks assembled with copper flat or flat heat pipes are applied into LED heat dissipation;temperature difference between test points are acquired by temperature test experiment with thesystem, temperature uniformity, response time and thermal resistance with different heat flux input areanalyzed.4. Three new type sinks with vertical heat pipe is designed, both related structure and methods ofvacuum or liquid filling are proposed, pipe material and working liquid are chosen after been analyzed; a net composed of copper wire is rolled as a simple pipe wick with lower thermal resistant,also can avoid displace or escape from the lining of the pipe.5. Thermal characteristics of heat pipe sink are analyzed by simulation with different variablefactors as pipe diameter d, pipe/fin height H and number of fin N; an optimized design methodby simulation is explored, by which heat pipe sink with smaller volume could be obtained and at thesame time make the chip junction temperature less than75℃.