Patent ID: 7675003
Filing Date: 2010-03-09
Classification: B23K,C09K,H01L

Abstract:
1. A laser irradiation device to irradiate a substrate, the device comprising: a light source; a mask arranged under the light source; and a projection lens arranged under the mask; wherein the mask includes a first region including a Fresnel lens arranged on a predetermined portion thereof to change an optical path of light generated by the light source and a second region including no Fresnel lens to allow the light generated by the light source to pass therethrough without changing an optical path of the light, the first and second regions lying in the same plane and the first region enclosing the second region; and wherein the light whose path has been changed by the Fresnel lens is focused onto an edge of a portion of the substrate irradiated by the irradiation device to produce an energy density greater than the energy density of other portions of the irradiated substrate.