Heat dissipation device

Abstract

A heat dissipation device includes a base, first and second fin units, two heat pipes, and a fan. The first fin unit is located on the base, and the second fin unit is located on the first fin unit. Each fin unit comprises a plurality of parallel fins with a plurality of channels defined therebetween. Each fin comprises an inlet section, an outlet section and a neck section interconnecting the inlet and outlet sections. A height of the neck section reduces gradually from the inlet section to the outlet section. Each heat pipe comprises an evaporating portion connecting with the base and a condensing portion inserting into a corresponding one of the outlet sections of the first and second fin units. The fan is located above the base and mounted onto the inlet sections of the first and second fin units.

1 . A heat dissipation device comprising:
 a base;   a fin unit comprising a plurality of parallel fins arranged on the base with a plurality of channels defined therebetween, each fin comprising a main plate perpendicular to the base and two flanges bent from edges of the main plate, the main plate comprising an inlet section, an outlet section and a neck section interconnecting the inlet and outlet sections, a height of the neck section reducing gradually from the inlet section to the outlet section; and   a fan located on the base and attached to the inlet sections of the fins, cooling air generated by the fan flowing into the channels via the inlet sections of the fins and accelerating to flow out from the outlet sections of the fins after the cooling air flows through the neck sections of the fins.   
   
   
       2 . The heat dissipation device as claimed in  claim 1 , wherein the main plate further comprises a bent section extending downwardly from a free end of the outlet section. 
   
   
       3 . The heat dissipation device as claimed in  claim 1 , wherein the neck section has a streamline shape. 
   
   
       4 . The heat dissipation device as claimed in  claim 1 , wherein the inlet sections of the fin unit are attached to the base and the neck sections and the outlet sections of the fin unit are spaced from the base. 
   
   
       5 . The heat dissipation device as claimed in  claim 1 , further comprising an additional fin unit located on the fin unit, the additional fin unit comprising a plurality of parallel fins with a plurality of channels defined therebetween, each fin of the additional fin unit comprising a main plate perpendicular to the base and two flanges bent from edges of the main plate, the main plate of the each fin of the additional fin unit comprising an inlet section, an outlet section and a neck section interconnecting the inlet and outlet sections of the each fin of the additional fin unit, a height of the neck section of the each fin of the additional fin unit reducing gradually from the inlet section to the outlet section of the each fin of the additional fin unit. 
   
   
       6 . The heat dissipation device as claimed in  claim 5 , wherein the inlet sections of the additional fin unit are attached to the inlet sections of the fin unit, the neck sections and the outlet sections of the additional fin unit and the fin unit are spaced from each other. 
   
   
       7 . The heat dissipation device as claimed in  claim 6 , wherein the outlet sections of the additional fin unit and the fin unit are parallel to each other, and a distance between the neck sections of the additional fin unit and the fin unit increases gradually from the inlet sections to the outlet sections. 
   
   
       8 . The heat dissipation device as claimed in  claim 7 , further comprising two heat pipes connecting the base, the fin unit and the additional fin unit. 
   
   
       9 . The heat dissipation device as claimed in  claim 8 , wherein the heat pipes are U-shaped and each comprise an evaporating portion connecting to the base, a condensing portion and a middle portion interconnecting the evaporating portion and the condensing portion, the condensing portion of each heat pipe inserting into a corresponding one of the fin unit and the additional fin unit. 
   
   
       10 . The heat dissipation device as claimed in  claim 9 , wherein two grooves are defined in the base, the evaporating portions of the heat pipes being received in the two grooves, and a hole is defined in each of the outlet sections of the fins of the fin unit and the additional fin unit, the condensing portions of the heat pipes being inserted in the holes, respectively. 
   
   
       11 . The heat dissipation device as claimed in  claim 10 , wherein the evaporating portion of one of the heat pipes is attached to a bottom of the inlet sections of the fin unit, and the condensing portion of the one of the heat pipes inserts into the outlet sections of the additional fin unit. 
   
   
       12 . The heat dissipation device as claimed in  claim 5 , wherein each of the main plates of the additional fin unit further comprises a bent section extending downwardly from a free end of the outlet section of the each of the main plates of the additional fin unit. 
   
   
       13 . A heat dissipation device comprising:
 a base;   a first fin unit and a second fin unit, the first fin unit located on the base, the second fin unit located on the first fin unit, each of the first and second fin units comprising a plurality of parallel fins with a plurality of channels defined therebetween, each fin comprising an inlet section, an outlet section and a neck section interconnecting the inlet and outlet sections, a height of the inlet section being larger than that of the outlet section, a height of the neck section reducing gradually from the inlet section to the outlet section;   two heat pipes each comprising an evaporating portion connecting with the base, and a condensing portion inserting into a corresponding one of the outlet sections of the first and second fin units; and   a fan located above the base and mounted to the inlet sections of the first and second fin units.   
   
   
       14 . The heat dissipation device as claimed in  claim 13 , wherein each fin of the first and second fin units further comprises a bent section extending downwardly from a free end of the outlet section thereof. 
   
   
       15 . The heat dissipation device as claimed in  claim 13 , wherein the inlet sections of the first fin unit are attached to the base, the neck sections and outlet sections of the first fin unit are spaced from the base. 
   
   
       16 . The heat dissipation device as claimed in  claim 13 , wherein the inlet sections of the second fin unit are attached to the inlet sections of the first fin unit, and the neck sections and outlet sections of the first and second fin units are spaced from each other. 
   
   
       17 . The heat dissipation device as claimed in  claim 16 , wherein the outlet sections of the first and second fin units are parallel to each other, and a distance between the neck sections of the first and second fin units increases gradually from the inlet sections to the outlet sections. 
   
   
       18 . The heat dissipation device as claimed in  claim 13 , wherein the evaporating portion of one of the heat pipes is attached to a bottom of the inlet sections of the first fin unit, and the condensing portion of the one of the heat pipes inserts into the outlet sections of the second fin unit. 
   
   
       19 . A heat dissipation device comprising:
 a base;   at least one fin unit arranged on the base and comprising a plurality of fins perpendicular to the base, with a plurality of channels defined therebetween, each fin comprising an inlet section, an outlet section, a neck section interconnecting the inlet and outlet sections, and a bent section extending downwardly from a free end of the outlet section, a height of the neck section reducing gradually from the inlet section to the outlet section;   at least one heat pipe comprising an evaporating portion connecting with the base and a condensing portion inserting into the outlet sections of the fins; and   a fan located on the base and mounted onto the inlet sections of the fins, cooling air generated by the fan flowing into the channels of the at least one fin unit via the inlet sections of the fins, speeding up at the neck sections, and consequently accelerating to flow out from the channels via the outlet sections and the bent sections of the fins.   
   
   
       20 . The heat dissipation device as claimed in  claim 19 , wherein the inlet sections of the at least one fin unit are attached to the base, the neck sections, the outlet sections and the bent sections of the at least one fin unit are spaced from the base.