A total internal reflection (TIR) linear lens of size 190 (W) × 5 (D) × 2.1 (H) ㎣ has a directivity of 25° and was made of a polydimethysiloxane (PDMS) silicone resin with a refractive index of 1.4 and a transmittance of 93% at 365 nm UV wavelength. A light source with a size of 190×25.5 ㎟ was fabricated by installing a TIR linear lens on a chip on board (COB) type LED module mounted with a 1.1×1.1 ㎟ size UV LED. The optical characteristics of the light source showed a maximum irradiation density of 3,840 mW/㎠ at a working distance of 5 mm and a high uniformity of 91.6% over a 150×25 ㎟ irradiation area. The thermal characteristics of the light source were measured at a supply current of 500 mA. The saturation temperature was reached after 30 min of operation, and measured to be 95℃.

The effect of co-sputtering condition on the structural properties of Mg_xZn_1-xO thin films grown by RF magnetron co-sputtering system was investigated for manufacturing UV LED. Mg_xZn_1-xO thin films were grown with ZnO and MgO target varying RF power. Structural properties were investigated by X-ray diffraction (XRD) and Energy dispersive spectroscopy (EDS). The Mg_xZn_1-xO thin films have sufficient crystallinity on the high ZnO power. The EDS analyzed showed that the Mg content in the Mg_xZn_1-xO films decreased from 3.99 to 24.27 at.% as the RF power of ZnO target increased. The Mg content in the Mg_xZn_1-xO films could be controlled by co-sputtering power.