New Tunable LED With Improved Heat Dissipation on Chip-on-Board

Abstract

In this article, a new tunable LED chip-on-board (COB) module is designed, providing the opportunity to adjust the color temperature for warm or white lighting, depending on the activities carried out by the users. The distribution of LEDs on the metal core is analyzed to determine an appropriate operating temperature during operation. This thermal improvement is achieved by increasing the gap between the die chips on the metal core, which allows for an increased exposed area for convection. In addition, uniform lighting distribution is achieved in accordance with photometric tests conducted in an integrating sphere. A numerical model is proposed and solved using the finite element method (FEM) to predict the temperature distribution over the COB LED. Subsequently, a prototype of the COB module is manufactured to perform measurements and test its performance during operation. The measurements are conducted using an infrared (IR) camera and thermocouples to obtain temperature profiles and identify critical hot spots during operation. The numerical model is validated and confirmed to be a reliable tool for evaluating predicted temperature models. The prototype meets all the thermal and photometric parameters required for reliable operation.