heat pipe 20 a a fixing block 60 a a supporting bracket 40 a and a fin assembly 50 a the heat pipe 20 a thermally connects the base plate 10 a the fixing block 60 a the supporting bracket 40 a and the fin assembly 50 a the base plate 10 a has a square body 11 a four ears 12 a extend horizontally from a center of each sidewall of the body 11 a four corresponding fasteners 70 a extend through the four ears 12 a for mounting the heat sink assembly 100 a onto a printed circuit board not shown an arced slot 110 a and a rectangular slot 112 a are defined crossing in the body 11 a the slots 110 a 112 a are both defined at a central portion of the body 11 a the slot 110 a is deeper than the slot 112 a the heat pipe 20 a comprises an arced evaporating portion 22 a and a pair of vertical condensing portions 24 a perpendicularly extending from two opposite ends of the evaporating portion 22 a the evaporating portion 22 a of the heat pipe 20 a is received in the slot 110 a of the base plate 10 a the fixing block 60 a is received in the slot 112 a of the base plate 10 a a pair of rivets 62 a extend through the fixing block 60.