A method of manufacturing a semiconductor package includes attaching semiconductor dies to an array of leadframes and positioning a clip array in alignment with the array of leadframes within a mold cavity, the clip array including clips that electrically connect to at least some of the semiconductor dies and a siderail along a perimeter of the clip array. The siderail forms a set of reliefs extending from an outer edge of the siderail to an inner edge of the siderail, the inner edge being adjacent to the array of leadframes. The method also includes injecting a mold compound into the mold cavity through a flow path including the set of reliefs of the siderail to form a mold block at least partially covering the semiconductor dies.