A heatsink structure and method for the cooling of closely spaced packaged heat-producing devices, such as dual-in-line memory modules (DIMMs). A folded sheet metal heatsink structure is provided which is constituted of a coined metallic material and which has a large plurality of waffle-shaped ridges extending therefrom constituting additional surface areas which are adapted to enable heat generated by hub chips to pass upwardly and then outwardly through waffle-like ridges and, thus, dissipated to the exterior, thereby imparting an improved degree of cooling to heat-producing components or devices.