Heat dissipation assembly

A heat dissipation assembly comprising:

• a printed circuit board supporting a chip thereon and defining a plurality of through holes around the chip;
• a backplate forming a plurality of posts received in the through holes of the printed circuit board, a plurality of cavities being defined in the posts;
• a heat sink assembly comprising a heat sink attached on the chip, and a plurality of bolts and springs, the heat sink defining a plurality of fixing holes therein, the bolts threadedly engaged with the fixing holes, the springs sandwiched between the bolts and the heat sink;
• the bolts being drivable to be unthreadedly engaged with the fixing holes and threadedly engaged with the cavities of the backplate, the heat sink being thereby secured to the printed circuit board, the heat sink being pressed by the springs to be in intimate and uniform contact with the chip.

A heat dissipation assembly comprising:

• a heat sink defining a plurality of fixing holes with inner threads therein;
• a plurality of bolts with associated springs thereon aligned with the corresponding fixing holes, each of said bolts including a lower threaded section and an upper unthreaded section;
• a chip located on one surface of a printed circuit board;
• wherein
• said heat sink is initially pre-assembled with the bolts and the springs, before said heat sink abuts against the chip, under a condition that the outer threaded sections of the bolts are engageably threaded with the inner threads of the corresponding fixing holes, respectively, with the corresponding springs in a more relaxed manner, while is finally assembled to an external device to have the heat sink tightly abut against the chip under a condition that the outer threaded sections of the bolts are engageably threaded with said external device and the unthreaded sections are freely received in the corresponding fixing holes, respectively, with the corresponding springs in a more stressed manner.