Abstract: To restrain detachment of heat sinks from printed circuit boards (PCBs) or the components mounted on such boards, a body is attached to the board and extends above the tops of the heat sinks. Above each heat sink, three sides of a rectangle are cut from the body, leaving one side uncut. The tongue thus formed is curved downwards to form a spring which bears against the top of the heat sink to protect the heat sink from disengagement. The body is formed with vertical ends or legs having outward bent feet which are secured to the PCB by screws or other fasteners or are fit through slots in the PCB. A slanted tongue may also be cut from the body to engage an upper corner of a heat sink to restrain the heat sink from lateral movement relative to the PCB.

Abstract: Because of space limitations, a small heat sink and a fan (of about 2".times.2".times.1/2" size) is used to cool to below 105.degree. C. (at an ambient temperature of about 40.degree. C.) a CPU chip (of about 16 mm.times.16 mm size) which uses about 30 watts current and is mounted on a motherboard of considerably larger size. A heat transferring thermostrate washer covers the chip and a pad covers the washer. Soldered to the pad is a square heat slug. Studs extend upward from the slug. The studs fit through holes in the base of the heat sink. The heat sink is of the type having plural rectangular cross-section fins extending upwardly from the base. Above the heat sink is a fan attached to the motherboard by screws at its four corners extending through heat slug and into the motherboard.