Development and Study of High-Reliability, High-Efficiency and High-Power LED Packages

LED (Light Emitting Diode), which converts the electron current into the light through the p-n junction of semiconductor diodes, has recently gained popularity world-wide. The high-power LEDs are found in a number of applications to high-volume consumer markets, such as illumination, signaling, screen backlights, automotives and so on. However, the challenges of power dissipation, high efficiency and good thermal reliability, are faced today for mass applications of the high-power LEDs. The objectives of this study are numerically and experimentally to investigate thermal, mechanical and optical behaviors of high-power LED packages, and to aim to develop a novel package for high-power LED with high efficiency and reliability. First of all, the thermal and environmental reliability tests of high-power LED packages will be carried out and the resulting failure modes will be documented. The thermally-induced strains and stresses of the packages will be analyzed in transient and steady states using a finite element method with thermo-mechanical models. Mechanical properties (such as elastic modulus, CTE, and strength) of packaging materials and LED dies will be characterized by DMA, TMA and material testing machine. The thermal conductivity of the substrates and thermal interface materials will be characterized using thermal-conductivity equipments. The concept of three dimensional stacked dies for generating a white light by mixing with red, green, and blue light beams will be proposed and verified through the prototyping test. The optical field of the LED packages will be simulated by Trace Pro software in order to improve the efficiency of light generation and thus be validated in light illumination test. Finally, a novel package design of high-power LED with high reliability and efficiency will be come up through the optimal material and structural designs, and will be evaluated through the thermal, reliability, and optical tests

Project ID:PB9706-1809
External Project ID:NSC96-2628-E182-005-MY2