Thermal simulation and analysis of flat surface flip-chip high power light-emitting diodes

Abstract

Conventional GaN-based flip-chip light-emitting diodes (CFC-LEDs) use Au bumps to contact the LED chip and Si submount, however the contact area is constrained by the number of Au bumps, limiting the heat dissipation performance. This paper presents a flat surface high power GaN-based flip-chip light emitting diode (SFC-LED), which can greatly improve the heat dissipation performance of the device. In order to understand the thermal performance of the SFC-LED thoroughly, a 3-D finite element model (FEM) is developed, and ANSYS is used to simulate the thermal performance. The temperature distributions of the SFC-LED and the CFC-LED are shown in this article, and the junction temperature simulation values of the SFC-LED and the CFC-LED are 112.80 ı C and 122.97 ı C, respectively. Simulation results prove that the junction temperature of the new structure is 10.17 ı C lower than that of the conventional structure. Even if the CFC-LED has 24 Au bumps, the thermal resistance of the new structure is still far less than that of the conventional structure. The SFC-LED has a better thermal property.

Improved light extraction efficiency of GaN-based flip-chip light-emitting diodes with an antireflective interface layer

“…[9][10][11] For example, in FC-LEDs, heat can dissipate through the Si submount, and the light output power will not be influenced by this because of optical blocking by the highly reflective electrodes. [12][13][14] However, the poor LEE of FC-LEDs is still a bottleneck in their development. [15][16][17] Therefore, it is important to further enhance the LEE of FC-LEDs, which may be achieved through an optimized FC-LED structure design grown on NPSS.…”

Performance enhancement of gallium-nitride-based flip-chip light-emitting diode with through-via structure

“…The highest p–n junction temperature of the bump‐free FC‐LED device was approximately 3% lower than that of the conventional HP‐LED. The 100.9 °C junction temperature was also lower than the 112.8 °C (FC‐LED bonded to Si substrate) .…”

An Efficient Method for Simulating the Temperature Distribution in Regions Containing YAG:Ce3+ Luminescence Composites of White LED

“…The quality of phosphor-converted white light-emitting diodes (pc-WLEDs) depends on many factors such as the blue LED die, type of yellow phosphor, packaging technology, packaging structure, and thermal management [4][5][6][7][8][9][10][11]. For better thermal management, it is not only necessary to reduce the amount of generated heat accumulated in the packaging volume, but also to know the temperature distribution characteristics [12][13][14]. In packaging technology, there are several main factors that affect the thermal characteristics of pc-WLEDs, including phosphor loss, geometry loss, weight concentration of yellow phosphor, Stoke loss, packaging structure, and the efficacy of the blue LED die [15][16][17].…”

“…Fu et al used commercial software based on the finite element method developed by COMSOL to conduct a 3D simulation of the thermal paths of the LED module to effectively evaluate its final steady state [13]. Chen et al developed a 3D finite element model (FEM) using ANSYS to simulate the thermal performance and temperature distributions of flat-surface high-power GaN-based flip-chip light-emitting diodes [14]. Tan et al used ANSYS software for the simulation of the temperature distribution of the encapsulated LED structure, wherein the phosphor is conformally coated onto the blue LED die, which is powered at 0.35 A [20].…”