Very high power density LED modules on aluminum substrates with embedded water cooling

We present optical measurements of an LED module consisting of 98 UV LEDs with an emission wavelength of 395 nm soldered onto a ceramic substrate within an area of 211 mm². The module is mounted to a high performance mi-crostructured water cooler. This cooler enables a maximum optical power density of 45.9 W/cm² at a forward current of 1350 mA and 447.9 W electrical input power. Further we describe the development of an LED module based on an aluminum substrate with thick film printed insulator and conductor layers and embedded, meander shaped water cooling channels. Numerical and experimental studies with different channel cross-sections are shown. Finally experimental results for this kind of UV LED module with 98 LED chips are presented and compared to the ceramic based module.