Heat dissipation device

Abstract

A heat dissipation device includes a fan and a heat sink located at the air outlet of the fan. The heat sink includes a first fin set arranged on a side portion of the air outlet, a second fin set arranged on a central portion of the air outlet and a third fin set. The first fin set includes a plurality of first fins with a first passage is defined between each two neighboring first fins. The second fin set includes a plurality of second fins with a second passage defined between each two neighboring second fins, a width of the second passage is less than that of the first passage. The third fin set includes a plurality of third fins. Each third fin is arranged between two neighboring first fins and divides an outer portion of the first passage away from the outlet of the fan into two third passages.

1 . A heat dissipation device comprising:
 a fan defining an air outlet at one side thereof, the air outlet comprising a first portion and a second portion, air pressure in the first portion being larger than air pressure of the second portion; and   a heat sink being located at the air outlet of the fan, the heat sink comprising a first fin set arranged at the first portion, a second fin set arranged at the second portion and a third fin set, the first fin set comprising a plurality of first fins stacked together with a first passage being defined between each two neighboring first fins, the second fin set comprising a plurality of second fins stacked together with a second passage being defined between each two neighboring second fins, the first passages and the second first passages communicating with the air outlet of the fan, a width of the second passage being less than that of the first passage, the third fin set comprising a plurality of third fins, each third fin being arranged between two neighboring first fins away from the air outlet of the fan, each third fin dividing an outer portion of the first passage away from the outlet of the fan into two third passages.   
     
     
         2 . The heat dissipation device of  claim 1 , wherein a width of the first passage is twice as that of the second passage. 
     
     
         3 . The heat dissipation device of  claim 1 , wherein a width of the second passage is equal to that of the third passage. 
     
     
         4 . The heat dissipation device of  claim 1 , wherein the fan is a centrifugal fan, the first portion being two opposite side portions of the air outlet, and the second portion being a central portion of the air outlet. 
     
     
         5 . The heat dissipation device of  claim 1 , wherein each first fin comprises a first main body and a pair of first flanges bent horizontally from a top and a bottom of the first main body, each first flange being abutted with a first flange of a neighboring fin, the first passage being formed between every two adjacent fins. 
     
     
         6 . The heat dissipation device of  claim 5 , wherein each second fin comprises a second main body and a pair of second flanges bent horizontally from a top and a bottom of the second main body, each second flange being abutted with a second flange of a neighboring second fin, the second passage being formed between every two adjacent second fins. 
     
     
         7 . The heat dissipation device of  claim 6 , wherein each of the third fins comprises a third main body and a third flange bending from the third main body, a width of the second flange and the third flange being less than that of the first flange. 
     
     
         8 . The heat dissipation device of  claim 6 , wherein each third fin comprises a third main body and a pair of third flanges bent horizontally from a top and a bottom of the third main body. 
     
     
         9 . The heat dissipation device of  claim 8 , wherein each first flange extending from a top edge of the first main body comprises a first portion near the air outlet air outlet of the fan and a second portion away from the air outlet of the fan. 
     
     
         10 . The heat dissipation device of  claim 9 , wherein a width of the second portion of the first flange is less than that of the first portion of the first flange, a width of the second flange being less than that of the first portion of the first flange, a width of the second flange being less than that of the first portion of the first flange. 
     
     
         11 . The heat dissipation device of  claim 10 , wherein a width of the first portion of the first flange is twice as that of the second portion of the first flange. 
     
     
         12 . The heat dissipation device of  claim 10 , wherein a width of the first portion of the first flange is twice as that of the second flange. 
     
     
         13 . The heat dissipation device of  claim 10 , wherein a width of the first portion of the first flange is twice as that of the third flange. 
     
     
         14 . A heat dissipation device comprising:
 a centrifugal fan defining an air outlet at one side thereof; and   a heat sink being located at the air outlet of the fan, the heat sink comprising two first fin sets arranged at two laterally side portions of the air outlet, a second fin set arranged between the first fin sets, and a third fin set, the first fin set comprising a plurality of first fins with a first passage being defined between each two neighboring first fins, the second fin set comprising a plurality of second fins with a second passage being defined between each two neighboring second fins, the third fin set comprising a plurality of third fins, each third fins being sandwiched between two neighboring first fins, a third passage being defined between a third fin and a neighboring first fin, a width of the second passage being less than that of the first passage, and a width of the third passage being less than that of the first passage.   
     
     
         15 . The heat dissipation device of  claim 14 , wherein a width of the second passage is equal to that of the third passage. 
     
     
         16 . The heat dissipation device of  claim 14 , wherein a width of the first passage is twice as that of the second passage. 
     
     
         17 . The heat dissipation device of  claim 14 , wherein a width of the first passage is twice as that of the third passage.