There is provided a heat sink including: a heat radiation plate having a heating element fixed to one surface thereof; a plurality of heat radiation fins formed on the other surface of the heat radiation plate to radiate heat generated in the heating element; a flange part provided on a heat radiation fin positioned in an outermost position among the plurality of heat radiation fins; and a fixing member inserted into the flange part to fix the heat sink to a printed circuit board, wherein the flange part is compressed in a predetermined position thereof, such that the fixing member and the flange part are coupled and fixed to each other.