Heat dissipation device

Abstract

A heat dissipation device includes a substrate, a fin assembly located on the substrate, a plurality of heat pipes connecting the substrate and the fin assembly, and a fan fixed on the substrate by a securing device. The securing device includes a holder fixed to the substrate and a plurality of elastic fasteners. The fasteners secure the fan onto the holder and each includes a sandwiched portion sandwiched between the fan and the holder to segregate the fan from the holder.

1 . A heat dissipation device comprising:
 a substrate;   a fin assembly comprising a first fin unit located on the substrate and a second fin unit located on the first fin unit, the second fin unit comprising a plurality of parallel fins with a plurality of channels defined between the fins, a receiving space being defined in the fin assembly; and   a fan fixed on the substrate by a securing device, the fan comprising a frame with positioning holes defined in the frame, and the securing device comprising a holder and a plurality of fasteners, the fasteners extending through the positioning holes of the frame to secure the fan to the holder and segregating the fan and the holder, the fan with the securing device being received in the receiving space of the fin assembly.   
   
   
       2 . The heat dissipation device as claimed in  claim 1 , wherein each of the fasteners comprises a head portion, a first connecting portion, a sandwiched portion, a second connecting portion, an abutting portion, and an inserting portion in series, the sandwiched portion segregating the fan and the holder. 
   
   
       3 . The heat dissipation device as claimed in  claim 2 , wherein the abutting portion is tapered to facilitate insertion of each fastener into a corresponding one of the positioning holes of the fan. 
   
   
       4 . The heat dissipation device as claimed in  claim 2 , wherein the frame of the fan is sandwiched between the abutting portion and the sandwiched portion, and the holder is sandwiched between the head portion and the sandwiched portion, whereby the fan is fixed on the holder by the fasteners. 
   
   
       5 . The heat dissipation device as claimed in  claim 4 , wherein the holder comprises a top plate and two lateral plates extending from the top plate, a plurality of first ears extending from the lateral plates through which the fasteners pass, the first ears being sandwiched between the head portion and the sandwiched portion. 
   
   
       6 . The heat dissipation device as claimed in  claim 5 , wherein the fasteners are elastic and the first connecting portions thereof are shorter than a thickness of the first ears of the holder, the second connecting portions thereof are shorter than a depth of the positioning holes of the fan. 
   
   
       7 . The heat dissipation device as claimed in  claim 5 , wherein the holder further comprises at least one first fixing tab extending from one of the first ears and fixed to the substrate. 
   
   
       8 . The heat dissipation device as claimed in  claim 5 , wherein the holder further comprises a plurality of second ears extending from the two lateral plates and spaced from the fan, and a plurality of second fixing tabs extending from the second ears fixed to the fin assembly. 
   
   
       9 . The heat dissipation device as claimed in  claim 1 , wherein the substrate comprises a main body and a supporting bar extending from the main body, a slot being defined between the main body and the supporting bar, the main body defining a plurality of grooves therein. 
   
   
       10 . The heat dissipation device as claimed in  claim 9 , further comprising a plurality of first heat pipes and a second heat pipe connecting the substrate and the fin assembly, wherein each of the first and second heat pipes comprises a heat absorption portion and two heat dissipation portions extending from the heat absorption portion, the heat absorption portions of the first heat pipes being received in the grooves of the main body of the substrate, the heat absorption portion of the second heat pipe being received in the slot of the substrate. 
   
   
       11 . The heat dissipation device as claimed in  claim 10 , wherein the fins of the second fin unit each comprise a main body and two flanges extending therefrom, the first fin unit comprises a main body and two lateral walls extending therefrom, and one of the lateral walls is located on a step formed on a top of the supporting bar of the substrate. 
   
   
       12 . The heat dissipation device as claimed in  claim 11 , wherein the main bodies of the first and second fin units each define a plurality of first holes through which the heat dissipation portions of the first heat pipes extend, a second hole through which one heat dissipation portion of the second heat pipe extends, and a receiving hole, the receiving holes cooperatively forming the receiving space receiving the fan therein, and another heat dissipation portion of the second heat pipe passing through the receiving space and attached to the main bodies of the first and second fin units. 
   
   
       13 . The heat dissipation device as claimed in  claim 12 , wherein the fin assembly further comprises a third fin unit located on the second fin unit, the third fin unit comprising a plurality of fins and defining a plurality of holes through which the heat dissipation portions of the first and second heat pipes extend. 
   
   
       14 . The heat dissipation device as claimed in  claim 13 , wherein the fin assembly further comprises a fourth fin unit covering the third fin unit, the first, second, third and fourth fin units defining a plurality of openings therein through which cooling air generated by the fan flows. 
   
   
       15 . A heat dissipation device comprising:
 a substrate comprising a main body and a supporting bar extending upwardly therefrom;   a fin assembly located on the substrate and comprising a plurality of parallel fins, each comprising a main body and two flanges extending downwardly therefrom;   a fan comprising a frame with positioning holes defined in the frame; and   a securing device fixing the fan to the main body of the substrate, the securing device comprising a holder fixed to the main body and a plurality of elastic fasteners, the fasteners securing the fan onto the holder, each comprising a sandwiched portion sandwiched between the fan and the holder to segregate the fan from the holder.   
   
   
       16 . The heat dissipation device as claimed in  claim 15 , wherein each of the fasteners comprises a head portion, a first connecting portion, the sandwiched portion, a second connecting portion and an inserting portion in series. 
   
   
       17 . The heat dissipation device as claimed in  claim 16 , wherein the holder comprises a plurality of first ears and a plurality of first fixing tabs extending therefrom, the first ears being inserted by the first connecting portions of the fasteners and sandwiched between the head portions and the sandwiched portions, and the first fixing tabs being fixed to the main body of the substrate. 
   
   
       18 . The heat dissipation device as claimed in  claim 17 , wherein the holder further comprises a plurality of second ears and a plurality of second fixing tabs extending therefrom, the second ears being spaced from the fan, and the second fixing tabs being fixed to the fin assembly. 
   
   
       19 . The heat dissipation device as claimed in  claim 15 , wherein the supporting bar defines a step at a top thereof, receiving one flange of the fin assembly thereon. 
   
   
       20 . The heat dissipation device as claimed in  claim 15 , wherein the fin assembly defines a receiving space receiving the fan and the securing device therein.