Heat sink, cooling module, electronic apparatus, and method of manufacturing heat sink

1. A heat sink that is configured to face an exhaust port of a blower fan, comprising:

a first plate-shaped portion;

a second plate-shaped portion in parallel with the first plate-shaped portion, and a gap therebetween;

a plurality of fins that are upstanding between the first plate-shaped portion and the second plate-shaped portion and are side-by-side with a gap therebetween to define an air flow path between the fins, and through which air can flow from the exhaust port;

a respective protrusion that is at a part of each fin including at a center of a respective upright height of each fin and protrudes into the air flow path;

wherein the protrusion has a plurality of bends in a portion of the fin to protrude toward an adjacent fin;

each fin includes:

a first plate piece that is a bend at a first end in the upright direction to protrude toward the adjacent fin; and

a second plate piece that is a bend at a second end in the upright direction to protrude toward the adjacent fin, wherein

the first plate pieces of the fins are side-by-side to define the first plate-shaped portion, and the second plate pieces of the fins are side-by-side to define the second plate-shaped portion.

2. The heat sink according to claim 1 , wherein

the protrusion comprises:

a first bend that is bent in a direction intersecting an upright direction of the fin;

a second bent that follows the first bend, and is bent in a direction in the upright direction of the fin;

a third bend that follows the second bend, and is bent in a direction intersecting the upright direction of the fin; and

a fourth bend that follows the third bend, and is bent in a direction along the upright direction of the fin.

3. The heat sink according to claim 2 , wherein:

the first, second, third, and fourth bends are at right angles.

4. The heat sink according to claim 2 , wherein:

the first, second, third, and fourth bends are at obtuse angles.

5. The heat sink according to claim 1 , wherein:

the first plate piece, the second plate piece, and the protrusion of each fin protrude in a same direction.

6. The heat sink according to claim 5 , wherein:

the first plate piece and the second plate piece have a same protrusion length, and

the protrusion has a protrusion length that is less than or equal to a protrusion length of the first plate piece and the second plate piece.

7. An electronic apparatus comprising:

a chassis on which a heating element is mounted; and

a cooling module mounted in the chassis to cool the heating element,

the cooling module comprising:

a blower fan;

a heat sink that faces an exhaust port of the blower fan; and

a heat transport device thermally connected to the heating element and the heat sink, the heat transport device transporting heat generated from the heating element to the heat sink,

the heat sink comprising:

a first plate-shaped portion;

a second plate-shaped portion in parallel with the first plate-shaped portion, and a gap therebetween;

a plurality of fins that are upstanding between the first plate-shaped portion and the second plate-shaped portion and are side-by-side with a gap therebetween to define an air flow path between the fins, and through which air can flow from the exhaust port; and

a respective protrusion that is at a part of each fin including at center of a respective upright height of each fin, and protrudes into the air flow path;

wherein the protrusion has a plurality of bends in a portion of the fin to protrude toward an adjacent fin;

each fin includes:

a first plate piece that is a bend at a first end in the upright direction to protrude toward the adjacent fin; and

a second plate piece that is a bend at a second end in the upright direction to protrude toward the adjacent fin, wherein

the first plate pieces of the fins are side-by-side to define the first plate-shaped portion, and the second plate pieces of the fins are side-by-side to define the second plate-shaped portion.

8. A method for manufacturing a heat sink, comprising:

bending a first end of a metal plate to form a first plate piece protruding in a first direction orthogonal to a plane direction of the metal plate;

bending a second end of the metal plate to form a second plate piece protruding in the first direction;

bending a part of the metal plate between the first end and the second end at least four times to form a protrusion that protrudes in a raised position in the first direction; and

placing a plurality of the metal plates each having the first plate piece, the second plate piece, and the protrusion, in parallel with each other so that the first plate pieces are continuous with each other to form a first plate, and the second plate pieces are continuous with each other to form a second plate, followed by bonding adjacent metal plates;

wherein the protrusion has a plurality of bends in a portion of the metal plate to protrude toward an adjacent metal plate;

each metal plate includes:

the first plate piece that is a bend at a first end in the upright direction to protrude toward the adjacent metal plate; and

the second plate piece that is a bend at a second end in the upright direction to protrude toward the adjacent metal plate, wherein

the first plate pieces of the metal plates are side-by-side to define the first plate, and the second plate pieces of the fins are side-by-side to define the second plate.