Thermal simulations of packaged IR LED arrays

Abstract

The steady-state and transient behaviors of packaged IR LED arrays have been studied via numerical simulations. The waste heat generated by LEDs must be removed through a cold plate or a cryogenic cold finger attached to the backside of the driver array. Therefore, this heat must travel across the LED array-driver interface and through the driver array. The modeling results demonstrate that the thermal resistance of these components can be significant. The steady-state temperature profiles across several configurations are used to identify the thermal bottlenecks. Transient simulations are used to quantify the rise and fall times of the IR LEDs, and the fall times can be significantly reduced by changes in the LED layout. These proposed guidelines to minimize thermal issues in LED arrays should result in better performing and more reliable IR LED arrays.