A white LED includes an LED chip formed on one main surface of a sapphire substrate, the LED chip being formed in a semiconductor stack structure including a light emitting layer and emitting light of a predetermined wavelength, a light extracting film applied on the other main surface of the substrate,...http://www.google.com/patents/US7737460?utm_source=gb-gplus-sharePatent US7737460 - White LED and manufacturing method therefor
