Ultra violet light-emitting diode (hereafter UV LED) curing units containing one or X array or XY arrays of UV LED modules with integrated optical, mechanical, and heat dissipation systems, and one, or X array, or XY arrays of extrusions with integrated air or liquid cooling systems to receive and house the integrated UV LED. The UV LED modules may be any size or shape depending on the power requirements of a given curing application. The LED chips or the groups of LED chips used for the above UV LED modules may be in other wavelengths for other applications. The UV LED modules have excellent heat dissipation because the LED chips or groups of LED chips are directly mounted on metal extrusion. The LED modules also have a single optical lens system between the LED chips and the surrounding ambient air.