A semiconductor package includes a package substrate, a power module on a first surface of the package substrate, a connector on the first surface of the package substrate, the connector being horizontally spaced apart from the power module, a first semiconductor chip on a second surface of the package substrate opposite to the first surface, and a first heat radiator on the second surface of the package substrate, the first heat radiator covering the first semiconductor chip. The first semiconductor chip vertically overlaps the power module, and the first semiconductor chip is electrically connected through the package substrate to the power module.

A memory device includes a first case, a second case coupled to the first case, a mid plate placed in an inner space between the first and second cases, a first memory module between the first case and the mid plate, including a first module substrate and at least one first electronic chip on the first module substrate, and a second memory module between the second case and the mid plate, including a second module substrate and at least one second electronic chip on the second module substrate, wherein the mid plate includes a base unit, a first rib structure extending from the base unit to electrically connect the mid plate to the first module substrate, and a second rib structure spaced apart from the first rib structure to electrically connect the mid plate to the first module substrate.

A heat dissipating member includes: a sintered material portion containing copper and at least one of tungsten and molybdenum; and a plurality of silicon oxide particles dispersed in the sintered material portion. The heat dissipating member has a copper content of M.sub.Cu weight percent, a tungsten content of M.sub.W weight percent, a molybdenum content of M.sub.Mo weight percent, and a silicon oxide content of M.sub.SiO2 weight percent in terms of SiO.sub.2 equivalent, relative to a total weight of copper, tungsten, and molybdenum. The heat dissipating member satisfies: 0.9M.sub.Cu/(M.sub.Cu+M.sub.W+M.sub.Mo)0.045; and 0.01M.sub.SiO2/(M.sub.Cu+M.sub.W+M.sub.Mo)0.0003.