Light Emitting Diode (LED) applications are increasingly used in various microelectronic devices due to their efficient light generation. The miniaturisation of the LED and its integration into compact devices within the weight limit have resulted in excessive heat generation, and inefficient management of this heat could lead to the failure of the entire system. Passive and/or active heat sinks are used for dissipating heat from the system to the environment to improve performance. An ANSYS design modeller and transient thermal conditions were utilised in this study to design and simulate the LED system. The modeller performs its function by utilising the Finite Element Method (FEM) technique. The LED system considered in this work consists of a chip, thermal interface material, and a cylindrical heat sink. The thickness of the Cylindrical Heat Sink (CHS) fins used in the investigation is between 2 mm and 6 mm, whilst ensuring the mass of heat sinks is not more than 100 g. The input power of the LED chip is between 4.55 W and 25.75 W, as required by some original equipment manufacturers (OEMs). A mesh dependency study was carried out to ensure the results were synonymous with what can be obtained practically. The simulation results suggest that the power ratings did not affect the thermal resistance of the CHS. In addition, the thermal resistance increased with the increased thickness of the CHS fin. The efficiencies of the heat sink were found to increase with an increased thickness of the cylindrical fin and the accuracy between the calculated and simulated thermal efficiency ranges from 84.33% to 98.80%. Evidently, the CHS fin of 6 mm thickness is more efficient than the other CHS fins, as depicted in this study.

The concern about thermal performance of microelectronics is on the increase due to recent over-heating induced failures which have led to product recalls. Removal of excess heat from microelectronic systems with the use of heat sinks could improve thermal efficiency of the system. This paper investigates the effect of change in heat sink geometry on thermal performance of aluminium and copper heat sinks in microelectronics. Numerical studies on thermal conduction through an electronic package comprising a heat sink, chip, and thermal interface material were carried out. The thickness of the heat sink base and the height of the heat sink fins were varied in the study. The minimum and maximum temperatures of aluminium and copper heat sinks in the two models were investigated using steady state thermal conduction analysis. Better heat dissipation occurred in thinner base thickness and extended fins height for both aluminium and copper heat sinks. Aluminium heat sink recorded the lowest minimum temperatures in both investigations and is recommended as optimal thermal management material for heat sink production.

Thermal characterisation of chip-scale packaged power devices is crucial to the development of advanced electronic packages for communication and automotive applications. Solder thermal interface materials (STIMs) are often employed in the packaging of power semiconductors to enhance heat dissipation from the chip to the heat spreader. However, voids formation in STIMs impedes heat flow and could result in increase in the chip peak temperature. Three-dimensional finite element analysis is employed to investigate the thermal effects of lead-free solder void percentages, locations and styles on packaged semiconductor device. The thermal resistance of each voiding case is calculated to evaluate the thermal response of the electronic package. The results show that the thermal resistance and peak temperature of electronic package can significantly increase depending on the percentage, location and style of voids. The results would assist packaging and design engineers in the characterisation of the thermal impacts of different solder void patterns.