PURPOSE: A heat radiation fin of a heat sink is provided to improve heat radiation performance by maximizing a contact area with a heat sink body and to maintain the distance of a flow space capable of releasing heat while improving reliability of combination. CONSTITUTION: A fin part(110) forms a body of a heat radiation fin(100). An upper side insertion part(130) is extended to the upper side and inner side of the fin part. A contact part(112) is formed in the inner side edge of the upper side insertion part to a vertical direction. A lower side folding block(121) is formed on the edge part of the upper side insertion part to the vertical direction. A lower side hook(122) is combined with a predetermined portion of the lower side folding block and interlinks a plurality of heat radiation fins.
