High power UV-LED-clusters on ceramic substrates

Abstract

We present a high power density UV-LED module for a wavelength of 395 nm with an optical power density of 13.1 W/cm2. The module consists of 98 densely packed LED chips adhesively bonded to an Al2O3-ceramic board. Thermal simulations and measurements as well as optical measurements were conducted. The module was cooled by a forced air heat sink for the characterization experiments. A surface micro cooler with water as a coolant is proposed to improve thermal performance of the module. To drive the LED module, we developed an efficient current source powered directly from AC mains supply with integrated power factor correction using a single switching component.