Abstract: An engagement securing device includes a support member disposed below a motherboard and having supporting and surrounding portions. The supporting portion is disposed closer to the motherboard than the surrounding portion. A first spacer member is disposed on the supporting portion and abuts against a lower side of the motherboard opposite to a central processing unit mounted on an upper side of the motherboard. Second spacers are disposed on the surrounding portion and abut against the lower side of the motherboard. A plurality of elongate tightening members are extended through tightening holes in the surrounding portion and tightening holes in the motherboard, and tightening holes in the heat sink.

Abstract: A heat dissipating device includes a base unit adapted to contact and to be in thermal communication with a heat-generating source. A plurality of parallel heat-dissipating fin units are provided on the base unit, each of which is spaced apart from each other and includes a mounting portion connected integrally to the base unit, two extensions extending respectively and integrally from opposite sides of the mounting portion, and a plurality of elongated parallel fin plates extending from an upper end of the mounting portion and from upper and lower ends of the extensions along a direction that is perpendicular to a bottom surface of the base unit.