Heat radiating device and manufacturing method of heat radiating device

Abstract

A heat radiating device for radiating heat of a circuit, includes a heat pipe which has a first straight portion and a second straight portion parallel with the first straight portion, and a curved portion connected to the first and second straight portions, a first base which is in contact with the circuit and is joined at a first surface thereof opposite to a surface thereof facing the circuit, to the first straight portion; a plurality of first fins which are provided on the first surface, have flat surfaces perpendicular to the first straight portion, and cross the second straight portion; a second base which has a second surface perpendicular to the first base and the first straight portion and is joined to the first heat pipe; and a plurality of second fins which are provided on the second surface and extend to a direction perpendicular to the second surface.

1 . A heat radiating device for radiating heat of a circuit, comprising:
 a first heat pipe which has a first end portion a first straight portion connected to the first end portion, a curved portion connected to the first straight portion, a second straight portion connected to the curved portion and parallel with the first straight portion, and a second end portion connected to the second straight portion;   a first base which is in contact with the circuit and is joined at a first surface thereof opposite to a surface thereof facing the circuit, to the first straight portion;   a plurality of first fins which are provided on the first surface, have flat surfaces perpendicular to the first straight portion, and cross the second straight portion;   a second base which has a second surface perpendicular to the first base and the first straight portion and is joined to the first heat pipe; and   a plurality of second fins which are provided on the second surface and extend to a direction perpendicular to the second surface.   
     
     
         2 . The heat radiating device according to  claim 1 , wherein
 a direction of a wind sent to the heat radiating device is parallel to the first base and the second base,   the plurality of first fins form therebetween a space which extends in the direction of the wind, and   the plurality of second fins form therebetween a space which extends in the direction of the wind.   
     
     
         3 . The heat radiating device according to  claim 1 , further comprising a second heat pipe which has a third end portion, a third straight portion connected to the third end portion, a curved portion connected to the third straight portion, a fourth straight portion connected to the curved portion and parallel with the third straight portion, and a fourth end portion connected to the fourth straight portion, wherein
 the first straight portion and the third straight portion are parallel with each other,   the second straight portion and the fourth straight portion are parallel with each other,   the first surface is joined to the third straight portion,   the plurality of first fins cross the fourth straight portion, and   the second base is joined to the second heat pipe.   
     
     
         4 . The heat radiating device according to  claim 1 , further comprising:
 a third base which has a third surface perpendicular to the first base and the first straight portion and is joined to the first heat pipe; and   a plurality of third fins which are provided on the third surface, wherein   the second base and the plurality of second fins are provided on a side of the first fins opposite to the first end portion and the second end portion, and   the plurality of third fins, the first end portion, and the second end portion are provided on a side of the third base opposite to the plurality of first fins.   
     
     
         5 . The heat radiating device according to  claim 1 , wherein each of the plurality of second fins has a pin shape perpendicular to the second surface, or has a rectangular shape perpendicular to the second surface and parallel with the first surface. 
     
     
         6 . The heat radiating device according to  claim 1 , wherein
 the second base and the plurality of second fins are provided on a side of the first fins opposite to the first end portion and the second end portion, and   the plurality of second fins are provided on a side of the second base opposite to the plurality of first fins.   
     
     
         7 . The heat radiating device according to  claim 1 , wherein
 the second base and the plurality of second fins are provided on a side of the first fins opposite to the first end portion and the second end portion, and   the second base is provided on a side of the plurality of second fins opposite to the plurality of first fins.   
     
     
         8 . The heat radiating device according to  claim 1 , wherein the second base is joined to the first base. 
     
     
         9 . The heat radiating device according to  claim 1 , wherein a length of the first base along a direction of the first straight portion is shorter than a length of the first straight portion and a length of the second straight portion. 
     
     
         10 . The heat radiating device according to  claim 1 , wherein the plurality of second fins are provided on the second surface by cold forging. 
     
     
         11 . A manufacturing method of a heat radiating device for radiating heat of a circuit, comprising:
 joining a first straight portion of the first heat pipe which has a first end portion, the first straight portion connected to the first end portion, a curved portion connected to the first straight portion, a second straight portion connected to the curved portion and parallel with the first straight portion, and a second end portion connected to the second straight portion, to a first surface of a first base for contacting the circuit, the first surface being opposite to a surface of the first base which faces the circuit;   mounting, on the first surface, a plurality of first fins which are provided on the first surface and have flat surfaces perpendicular to the first straight portion;   joining the plurality of first fins and the second straight portion so as to cross each other; and   joining, to the first heat pipe, a second base which has a second surface perpendicular to the first base and the first straight portion and on the second surface of which a plurality of second fins are provided so as to be perpendicular to the second surface.   
     
     
         12 . The manufacturing method according to  claim 11 , further comprising providing the plurality of second fins on the second surface by cold forging. 
     
     
         13 . The heat radiating device according to  claim 1 , wherein each of the plurality of second fins has a plate shape perpendicular to an up-down direction of the heat radiation device. 
     
     
         14 . The heat radiating device according to  claim 1 , further comprising a second heat pipe which has a third end portion, a third straight portion connected to the third end portion, a curved portion connected to the third straight portion, a fourth straight portion connected to the curved portion and parallel with the third straight portion, and a fourth end portion connected to the fourth straight portion, wherein
 a distance between the first straight portion and the third straight portion is less than a distance between the second straight portion and the fourth straight portion.   
     
     
         15 . The heat radiating device according to  claim 7 , wherein
 the second base includes at least one groove for burying therein the curved portion of the first heat pipe.