The Real-time Thermal Resistance Analy-sis For High Power LED Based On Multi-point Temperature Measurement

With the continuous development of semiconductor lighting technology,LED has been used in more and more lighting field, and the high power LED ap-pears. However, with the unceasingly increase of the power for LED, the heatdissipation problem becomes very serious. Then as the key parameter for measur-ing thermal performance, it is of great theoretical and practical significance tothermal resistance analysis. If the value of thermal resistance is too big, the tem-perature will rise, which makes a bad effect on wavelength, luminous efficiency,the forward voltage and service life of high power LED. Therefore, this paperproposes a real-time thermal resistance analysis method for high-power LEDbased on multi-point temperature measurement.Firstly, this paper has made an in-depth research on thermal resistance andexplains the purpose and significance of the subject and the current state of high-power LED thermal resistance research. Then this paper elaborates the basictheory of high-power LED thermal resistance analysis, including the basic way ofheat transfer, the basic concept and analysis methods of high-power LED thermalresistance. According to the study of the basic theory for thermal resistance, thispaper proposes an analysis method based on multi-point temperature measure-ment.Then in order to realize thermal resistance analysis based on multi-pointtemperature measurement, this paper designs data collection scheme according tothe method of thermal resistance analysis, and it is made up of multi-point tem- perature data measurement, voltage and current signals acquisition and conver-sion and RS-232serial communication module. Then it is realized by VC++toanalyse steady and transient thermal resistance in real time on the computer in-cluding the display of thermal resistance and its main parameters. And the ther-mal resistance analysis is uesed in the optimization of aluminum board heat dis-sipating performance. In addition, Hilbert-Huang transform is applied to thethermal resistance analysis to denoise for the data: firstly thermal resistance datais disassemble to a limited number of IMFs by the EMD algorithm and then thispaper takes the Hilbert transform to deal with the IMFs for getting the Hilbertspectrum and distinguish the noise signals which realizes the further analysis andprocessing for data.Finally, the uncertainty of the high power LED thermal resistance analysis iscalculated to verify the authenticity and reliability of the whole analysis in thispaper.