JPH10163388A - Heat sink and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To directly conduct the heat generated from a power module to a fin part via a heat receiving part, and improve cooling efficieincy, by mutually bonding a heat receiving part to at least one end portion of a plate fin which receiving part is collectively molded by injection molding of aluminum material and has a heat generating element in the outside. SOLUTION: On both end portions of plate fins 12A which are arranged in parallel at predetermined intervals in the side surface direction, heat receiving parts 17 wherein a power module 19 is mounted on a heat receiving surface 17a is collectively formed by extrusion molding of aluminum material. The formed heat receiving part 17 is mutually bonded to a neighboring plate fin 13A. Thereby the heat generated from the power module 19 can be directly conducted to a fin part 15A via the heat receiving part 17, and cooling efficiency can be improved. According to the required cooling capability, the arrangement number and the length size of the plate fins 13A can be easily changed, so that coping with a wide range of cooling capability is enabled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a rectifier diode,
The present invention relates to a heat sink for cooling a power module that generates heat, such as a large capacity transistor, and a method for manufacturing the same.

[0002]

2. Description of the Related Art Generally, in electronic equipment such as a computer and a communication switching device, a rectifier diode and a large-capacity transistor for rectifying an AC power supply to a DC power supply, and an MPU (microprocessor) for performing high-speed arithmetic processing of processing instructions. A power module that generates heat, such as a processing unit) or an MCM (multi-chip module), is arranged.

[0003] In these power modules, if the temperature continues to rise and exceeds a predetermined junction temperature, internal elements are damaged. Conventionally, in order to cool this type of power module, for example, Japanese Patent Application Laid-Open No. 5-275874. The heat sink disclosed in Japanese Patent Application Laid-Open Publication No. H10-264 is widely known. FIG.
Indicates the heat sink disclosed in this publication,
In this heat sink, a pair of heat receiving members 1 are arranged to face each other with an interval.

A plurality of fin units 2 are arranged between these heat receiving members 1 in parallel with each other. The fin unit 2 has a pair of plate fins 2a formed in parallel at intervals. At the upper and lower portions of these plate fins 2a, there are provided connecting portions 2b for connecting the plate fins 2a to each other. It is formed integrally by extrusion of an aluminum material.

The upper end of the plate fin 2a is
The lower surface of the plate fin 2a is soldered to the lower surface of the heat receiving member 1 while being abutted to the lower surface of the heat receiving member 1. In the above-described heat sink, a plurality of fin units 2 in which a pair of plate fins 2a are integrally formed by extrusion molding of an aluminum material are arranged between the heat receiving members 1, so that the heat received by the heat receiving member 1 is reduced by a plurality of fin units. The heat is conducted to the plate fins 2a, and heat can be radiated from the surface of the plate fins 2a to the atmosphere.

However, Japanese Unexamined Patent Application Publication No. Hei 5-275
In the heat sink disclosed in Japanese Patent Publication No. 874, a plurality of fin units 2 in which a pair of plate fins 2a are integrally formed by extrusion of an aluminum material are arranged between the heat receiving members 1, so that the adjacent plate fins 2a It is difficult to form the space densely with respect to the length dimension (tongue ratio), and there is a problem that the surface area of the plate fin 2a cannot be increased and the cooling capacity cannot be increased.

In the above-described heat sink, a fin unit 2 in which a pair of plate fins 2a are integrally formed in parallel at a distance is arranged between the heat receiving members 1, and the upper end and the lower end of the plate fin 2a are arranged at the upper and lower ends. Since the soldering is performed in a state where the heat receiving member 1 and the lower surface and the upper surface of the heat receiving member 1 abut against each other, the heat receiving member 1 and the fin unit 2 do not uniformly contact with each other due to the processing accuracy of the heat receiving member 1 and the fin unit 2. As a result, there is a problem that the heat transfer efficiency is reduced and the cooling efficiency is impaired.

Therefore, as a heat sink that solves such a problem, a heat sink disclosed in Japanese Patent Application Laid-Open No. Hei 6-21282 is known. FIG. 8 shows a heat sink disclosed in this publication. In this heat sink, a rectangular frame-shaped heat receiving member 3 is formed by extrusion of an aluminum material.

A plurality of fitting grooves 3a are formed on the opposed inner wall surfaces of the heat receiving member 3 by extrusion molding at intervals. The plate fins 4 are fitted in these fitting grooves 3a, and are fixed by swaging. In the above-described heat sink, the heat receiving member 3 in which a plurality of fitting grooves 3a are formed at intervals on opposing inner wall surfaces is integrally formed by extrusion molding.
Since the plate fins 4 are fitted into the fitting grooves 3a of the above and fixed by caulking, the spacing between the adjacent plate fins 4 can be made close to the length dimension, and the cooling capacity can be increased. Can be.

Further, since the plate fins 4 are fitted into a plurality of fitting grooves 3a formed at intervals on the inner wall surface of the heat receiving member 3 and then fixed by caulking, the plate fins 4 are fixed. 3 can be uniformly contacted,
Heat transfer efficiency can be improved.

[0011]

However, in the heat sink disclosed in the above-mentioned Japanese Patent Application Laid-Open No. Hei 6-21282, separate fitting grooves 3a are formed on the inner wall surface of the heat receiving member 3 at intervals. Plate fin 4 formed of
Are fixed by caulking after being fitted, heat is conducted through the contact surface between the plate fins 4 and the heat receiving member 3, and there is a problem that heat transfer loss is large and cooling efficiency is low.

Further, since the plurality of plate fins 4 are arranged inside the heat receiving member 3 formed in a rectangular frame shape by extrusion of an aluminum material, the size of the heat receiving member 3 is limited by the performance of the extrusion molding machine. Therefore, there is a problem that it is difficult to increase the size.

Further, since a plurality of plate fins 4 are arranged inside a heat receiving member 3 formed in a rectangular frame shape by extrusion molding of an aluminum material, a large number of types of heat receiving members are provided depending on a required cooling capacity. Since the members are required, the management work of the stock parts becomes complicated, and there is a problem that a large number of manufacturing steps are required. In the heat sink described above, the plate fins 4 formed separately from the fitting grooves 3 a formed at intervals on the inner wall surface of the heat receiving member 3.
After the fitting, the heat receiving member 3 and the plate fins 4 are fixed to each other. Therefore, in order to assemble the heat receiving member 3 and the plate fins 4, the fitting operation of fitting the plate fins 4 into the narrow fitting grooves 3a and the spacing are tight. A caulking operation is required in which a caulking jig is inserted between the arranged plate fins 4 and caulked and joined, so that the assembling operation is complicated and a large number of manufacturing steps are required.

The present invention has been made to solve such a conventional problem, and the number of plate fins can be easily changed according to a required cooling capacity, and the present invention is more effective than the conventional one. Improving the cooling efficiency,
It is another object of the present invention to provide a heat sink and a method for manufacturing the heat sink, which can easily perform an assembling operation and reliably reduce the number of manufacturing steps.

[0015]

According to a first aspect of the present invention, there is provided a heat sink having a plurality of plate fins arranged in parallel at predetermined intervals in a lateral direction, wherein at least one end of each of the plurality of plate fins is made of aluminum. A heat receiving portion integrally formed by extrusion of a material and having a heating element disposed on an outer surface thereof; and a heat receiving portion joining means for joining the heat receiving portions formed on the adjacent plate fins to each other. And

The heat sink according to the second aspect is the first aspect.
In the heat sink according to the aspect, the heat receiving unit joining means includes:
The joining convex portion formed on one side surface of the heat receiving portion and projecting in the lateral direction of the plate fin, and the joining convex portion of the adjacent heat receiving portion formed on the other side surface of the heat receiving portion are fitted. And a joint recess.

The heat sink according to the third aspect is the second aspect.
The heat sink according to any one of the preceding claims, wherein the joining protrusion formed on the heat receiving portion and the joining recess formed on the adjacent heat receiving portion are caulked and joined. A heat sink according to a fourth aspect is characterized in that, in the heat sink according to any one of the first to third aspects, the heat receiving portions are integrally formed at both ends of the plate fin.

According to a fifth aspect of the present invention, there is provided a method for manufacturing a heat sink, comprising: an extruding step of forming a plate fin having heat receiving portions integrally formed at both ends by extruding an aluminum material; and cutting the length of the plate fin to a predetermined size. A cutting step of arranging a predetermined number of the plate fins in parallel in a lateral direction, overlapping the adjacent heat receiving portions so as to be positioned in parallel with each other, and the adjacent heat receiving portions formed on the plate fins. And a joining step of joining the parts to each other.

According to a sixth aspect of the present invention, there is provided a method of manufacturing a heat sink, comprising:
After the joining step, a dividing step of cutting a fin portion formed on the plate fin in a pushing direction at a predetermined position is performed.

(Function) In the heat sink according to the first aspect, an aluminum material is formed by extruding an aluminum material at at least one end of a plate fin arranged in parallel at a predetermined interval in a lateral direction, and a heating element arranged on an outer surface. The heat receiving portions formed integrally by molding and formed on adjacent plate fins are joined to each other by heat receiving portion joining means.

In this heat sink, the heat generated from the heating element disposed in the heat receiving portion is transmitted to the plate fins via the heat receiving portion, and the heat is exchanged with the working fluid flowing on the surface of the plate fins. The heating element is cooled.

In the heat sink according to the second aspect, a joining convex portion protruding in the lateral direction of the plate fin is formed on one side surface of the heat receiving portion, and a joining convex portion of the adjacent heat receiving portion is formed on the other side surface of the heat receiving portion. A fitting projection to be fitted is formed. In the heat sink according to the third aspect, the joining convex portion formed on the heat receiving portion and the joining concave portion formed on the adjacent heat receiving portion are caulked.

In the heat sink according to the fourth aspect, the heat receiving portions are integrally formed on both ends of the plate fin, and the heating elements are arranged on both end surfaces of the plate fin. In the method for manufacturing a heat sink according to the fifth aspect, the plate fins having the heat receiving portions integrally formed at both ends by extrusion molding are cut into a predetermined size, and a predetermined number of plate fins are arranged so that the adjacent heat receiving portions are positioned parallel to each other. Then, the adjacent heat receiving portions are joined to each other.

In the method for manufacturing a heat sink according to the sixth aspect, after the heat receiving portions of the adjacent plate fins are joined to each other, the fin portions formed on the plate fins are cut at predetermined positions in the extrusion direction.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a first embodiment (corresponding to claims 1 to 4) of a heat sink of the present invention. In the drawing, reference numeral 11 denotes a heat sink. The heat sink 11 has a plurality of plate fins 13A formed by extrusion of an aluminum material. These plate fins 13A are arranged in parallel to face each other in the lateral direction.

The plate fin 13A is integrally formed with a plate-shaped fin portion 15A which is arranged to face at a distance. At both ends of the fin portion 15A, a rectangular heat receiving portion 17 is integrally formed by extrusion molding (corresponding to claim 4).

A flat heat receiving surface 17a is formed on the upper and lower surfaces of the heat receiving portion 17 in the drawing, and the surface of the heat receiving surface 17a has a surface roughness by cutting after a joining step described later. It is formed smoothly. A power module (heating element) 19 is mounted on the heat receiving surface 17a, and the heat generating surface of the power module 19 is connected to the heat receiving surface 17a.
a.

Further, on the side surface of the plate fin 13A,
By joining the adjacent heat receiving portions 17 to each other, a heat medium passage 21 surrounded by the side surface of the opposed fin portion 15A is formed. A blower fan 23 is arranged on the inner side of the working fluid flow path 21 in the figure, and is fixed to an end face of the heat receiving portion 17 of the plate fin 13A by a screw (not shown).

In this embodiment, the aluminum material is A
6063S-T5, the plate thickness of the fin portion 15A of the plate fin 13A is 1.0 mm, the interval between adjacent fin portions 15A is 3.0 mm, and the heat receiving portion 17 of the plate fin 13A is The interval is 150mm
It has been. FIG. 2 shows the heat receiving portion 17 of the plate fin 13A and the vicinity thereof, and a joining convex portion 25 projecting in the side direction of the plate fin 13A is integrally formed on the right side surface of the heat receiving portion 17 by extrusion. (Corresponding to claim 2).

At the tip of the joining projection 25, a fin 1
An arc-shaped fitting projection 25a projecting in a direction parallel to 5A is integrally formed. Further, the joining convex portion 25 of the heat receiving portion 17
A joint concave portion 27 having an inner peripheral surface shape corresponding to the outer peripheral surface shape of the joint convex portion 25 is integrally formed on the side surface opposite to the above (corresponding to claim 2).

The fin 15 is formed on the bottom of the joint recess 27.
A concave fitting portion 27a which is depressed in an arc shape in a direction parallel to the portion A is integrally formed. At the tip of the joint recess 27, an arc-shaped guide portion 27b that spreads outward is formed to face the same. In this embodiment, the outer side surfaces of the heat receiving portions 17 of the plate fins 13A arranged on both end surfaces are formed flat.

Then, the joining convex portion 2 of the adjacent heat receiving portion 17
5 and the joint concave portion 27 are inserted, the fitting convex portion 25a of the joint convex portion 25 and the concave fitting portion 27a of the joint concave portion 27 are caulked and joined, and the adjacent plate fins 13A are fixed to each other. 3). Heat sink 1 described above
1 is manufactured as described below (corresponding to claim 5).

First, an extruded plate fin 1
3A is cut into lengths according to the required cooling capacity. Then, as shown in FIG. 3A, the plate fins 13 </ b> A in a number corresponding to the required cooling capacity are fixed such that the joint convex portions 25 and the joint concave portions 27 of the adjacent heat receiving portions 17 face each other. Superimpose on jig G1.

That is, the required cooling capacity can be obtained by the length of the plate fins 13A and the number of overlaps. Then, as shown in FIG. 3 (b), after the pressing jig G2 is arranged on the upper surface of the plate fin 13A, the pressing jig G2 is pressed toward the fixing jig G1 to obtain the configuration shown in FIG.
As shown in (1), the fitting projection 25a of the joining projection 25 and the recess fitting section 27a of the joining recess 27 are caulked and joined, and the adjacent plate fins 13A are fixed to each other.

In the above-described heat sink 11, as shown in FIG. 1, after the heat generated from the power module 19 mounted on the heat receiving surface 17a is conducted to the heat receiving portion 17 of the plate fin 13A, the heat is received from the heat receiving portion 17. Heat is radiated from the side surface of the fin portion 15A by the cooling air that is directly transmitted to the portion 15A and blown from the blower fan 23.

The heat sink 11 configured as described above
Then, the heat receiving portions 17 to which the power module 19 is mounted on the heat receiving surface 17a are integrally formed on both ends of the plate fins 13A arranged in parallel at a predetermined interval in the side direction by extrusion of an aluminum material. Since the heat receiving portions 17 formed on the plate fins 13A are joined to each other, the heat generated from the power module 19 can be directly conducted to the fin portions 15A via the heat receiving portion 17 integrally formed. The cooling efficiency can be improved.

The heat receiving portions 17 are integrally formed at both ends of the plate fins 13A by extrusion of an aluminum material, and the adjacent heat receiving portions 17 are joined to each other. The number of arrangements and the length can be easily changed, and a wide range of cooling capacity can be easily accommodated. Further, a joining protrusion 25 protruding in the lateral direction of the plate fin 13 </ b> A is formed on the right side surface of the heat receiving portion 17, and a joining protrusion 25 of the adjacent heat receiving portion 17 is fitted on the left side surface of the heat receiving portion 17. Since the convex portion 25 is formed, the plurality of plate fins 13A can be easily overlapped so that the adjacent heat receiving portions 17 are positioned in parallel with each other, and the overlapping step of overlapping the plate fins 13A is reliably reduced. Can be.

In the heat sink 11 described above, the fitting projection 2 is attached to the tip of the joining projection 25 formed in the heat receiving section 17.
5a, and a joining recess 27 into which the joining projection 25 is fitted.
A concave fitting portion 27a is formed on the bottom surface of the
Are fixed together by caulking, so that the heat receiving portions 17 of the adjacent plate fins 13A can be fixed easily and reliably, and the joining step of joining the plate fins 13A can be reliably reduced.

Further, since the heat receiving portions 17 are integrally formed at both ends of the plate fin 13A and the power module 19 is disposed on the heat receiving surface 17a of the heat receiving portion 17, the mounting density of the power module 19 can be easily increased. The placement space can be used effectively. Further, in the above-described heat sink 11, the plate fins 13A formed integrally with the heat receiving portions 17 at both ends by extrusion molding are cut into a predetermined length, and the predetermined number of the plate fins 13A are parallel to each other. Then, since the adjacent heat receiving portions 17 are joined to each other, the assembling work can be easily performed, and the manufacturing process can be reliably reduced.

FIG. 4 shows a heat sink according to a second embodiment of the present invention (corresponding to claims 1, 2, 3, 5, and 6). In the drawing, reference numeral 31 denotes a heat sink. The heat sink 31 has a plurality of plate fins 13B formed by extrusion of an aluminum material. These plate fins 13B are arranged in parallel to face each other in the lateral direction.

A plate-shaped fin portion 15B is integrally formed with the plate fin 13B, and is opposed to each other with an interval. At the lower end of the figure of the fin portion 15B,
A rectangular heat receiving portion 17 is integrally formed by extrusion molding. On the right side surface of the heat receiving portion 17 in the drawing, a joining convex portion 25 protruding in the side direction of the plate fin 13B is integrally formed.

On the left side of the drawing of the heat receiving portion 17, a joining concave portion 27 into which the joining convex portion 25 is fitted is formed.
The joining convex portion 25 and the joining concave portion 27 of the adjacent heat receiving portion 17 are caulked and fixed to each other. A flat heat receiving surface 17a is formed on the lower surface of the heat receiving portion 17 in the drawing, and the surface of the heat receiving surface 17a has a smooth surface roughness formed by cutting.

A power module (heating element) 33 is mounted on the heat receiving surface 17a, and the heat generating surface of the power module 33 is in close contact with the heat receiving surface 17a. The other parts are configured in the same manner as in the first embodiment. Therefore, the same parts are denoted by the same reference numerals, and detailed description will be omitted. The above-described heat sink 31 is manufactured as described below (corresponding to claim 6).

As shown in FIG. 5, after the heat sink 11 in which the heat receiving portions 17 are integrally formed at both ends of the plate fin 13A shown in the first embodiment is fixed to the fixing jig G3 of the cutting machine. Fin portion 15A of plate fin 13A
Are cut in the extrusion direction, and a heat sink 31 in which the heat receiving portion 17 is formed only at one end of the fin portion 15B of the plate fin 13B is formed (corresponding to claim 6).

The heat sink 31 configured as described above
In this case, substantially the same effect as that of the heat sink 11 of the first embodiment can be obtained, but in this embodiment,
The fin portion 15A of the plate fin 13A is cut in the extrusion direction, and the heat receiving portions 17 are provided at both ends of the plate fin 13A.
Since the heat sink 11 integrally formed is divided, the heat receiving portion 17 is formed only at one end of the fin portion 15B of the plate fin 13B, and the blowing direction of the cooling air can be selected from a wide range. it can.

The first embodiment and the second embodiment
In the embodiment, the joining convex portion 25 formed on the heat receiving portion 17 is provided.
Forming a fitting projection 25a at the tip of the joint, forming a recess fitting section 27a on the bottom surface of the joining recess 27 into which the joining projection 25 is fitted,
Although the example in which the adjacent heat receiving portions 17 are fixed to each other by caulking has been described, the present invention is not limited to such an embodiment, and a through hole 37a is formed in the side surface of the heat receiving portion 37 as shown in FIG. Then, the rivet 39 is inserted into the through hole 37a, and the tip of the rivet 39 is caulked,
Adjacent heat receiving portions 37 can also be joined to each other.

Further, for example, an epoxy-based adhesive may be applied between the joining convex portion and the joining concave portion of the heat receiving portion, and the adjacent heat receiving portions may be joined to each other. Furthermore, in the above-described first embodiment, an example has been described in which the heat of the power module 19 conducted from the heat receiving unit 17 is radiated by the cooling air blown from the blower fan 23, but the present invention is limited to such an embodiment. Instead, a heat medium fluid such as water or oil may be caused to flow into the heat medium flow path to perform liquid cooling.

[0049]

As described above, in the heat sink according to the first aspect, at least one end portion of the plate fins arranged in parallel with a predetermined spacing in the lateral direction, the heat receiving portion having the heating element disposed on the outer surface. Are integrally formed by extrusion of an aluminum material, and the heat receiving portions formed on the adjacent plate fins are joined to each other by the heat receiving portion joining means, so that the heat generated from the heating element is formed through the heat receiving portion that is integrally formed. The heat can be directly transmitted to the fins, and the cooling efficiency can be greatly improved as compared with the conventional case.

Further, at least one end of the plate fin is integrally formed with a heat receiving portion on which an exothermic body is disposed by extrusion of an aluminum material, and the heat receiving portion formed on the adjacent plate fin is joined to the heat receiving portion joining means. Therefore, the number of arranged plate fins can be easily changed according to the required cooling capacity, and a wide range of cooling capacity can be easily accommodated.

In the heat sink according to the second aspect, a joining convex portion protruding in the lateral direction of the plate fin is formed on one side surface of the heat receiving portion, and the joining convex portion of the adjacent heat receiving portion is formed on the other side surface of the heat receiving portion. Since the joining projections to be fitted are formed, the plurality of plate fins can be easily overlapped so that the adjacent heat receiving portions are positioned parallel to each other, and the overlapping step of overlapping the plate fins is reliably reduced. be able to.

In the heat sink according to the third aspect, the joint convex portion formed on the heat receiving portion and the joint concave portion formed on the adjacent heat receiving portion are fixed by caulking.
The heat receiving portions of the superposed adjacent plate fins can be simply and reliably fixed, and the joining step of joining the plate fins can be reliably reduced.

In the heat sink according to the fourth aspect, the heat receiving portions are integrally formed at both ends of the plate fin, and the heating elements are arranged on both end faces of the plate fin, so that the mounting density of the heating elements can be easily increased. Can be used effectively. In the method for manufacturing a heat sink according to the fifth aspect, the plate fins having the heat receiving portions integrally formed at both ends by extrusion molding are cut into a predetermined size, and a predetermined number of plate fins are arranged so that the adjacent heat receiving portions are positioned parallel to each other. Then, the adjacent heat receiving portions are joined to each other, so that the assembling work can be easily performed, and the manufacturing process can be reliably reduced.

In the method for manufacturing a heat sink according to the sixth aspect, the heat receiving portions of the adjacent plate fins are joined to each other, and then the fin portions formed on the plate fins are cut at predetermined positions in the extrusion direction. The heat receiving portion is formed only at one end of the plate fin, so that a heat sink capable of widely selecting a working fluid flow path can be easily manufactured.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a first embodiment of a heat sink of the present invention.

FIG. 2 is a front view showing a heat receiving portion of the heat sink of FIG. 1 and its vicinity.

FIG. 3 is an explanatory view illustrating a method of manufacturing the heat sink of FIG. 1;

FIG. 4 is a perspective view showing a second embodiment of the heat sink of the present invention.

FIG. 5 is an explanatory view illustrating a method for manufacturing the heat sink of FIG.

FIG. 6 is a front view showing another embodiment of the heat sink of the present invention.

FIG. 7 is a front view showing a conventional heat sink.

FIG. 8 is a front view showing a conventional heat sink.

[Explanation of symbols]

 13A, 13B Plate fin 15A, 15B Fin part 17, 37 Heat receiving part 19, 33 Power module (heating element) 25 Joint convex part 27 Joint concave part

Claims (6)

[Claims] 1. A heat sink comprising a plurality of plate fins arranged in parallel at predetermined intervals in a lateral direction, wherein at least one end of each of the plurality of plate fins is integrally formed by extrusion of an aluminum material, and heat is generated on an outer surface. A heat sink, comprising: a heat receiving portion on which a body is disposed; and heat receiving portion joining means for joining the heat receiving portions formed on the adjacent plate fins to each other. 2. The heat sink according to claim 1, wherein the heat receiving portion joining means is formed on one side surface of the heat receiving portion and protrudes in a side direction of the plate fin, and the heat receiving portion further includes: And a joint recess formed on the side surface and fitted with the joint protrusion of the adjacent heat receiving section. 3. The heat sink according to claim 2, wherein the joining convex portion formed on the heat receiving portion and the joining concave portion formed on the adjacent heat receiving portion are caulked and joined. . 4. The heat sink according to claim 1, wherein the heat receiving portions are integrally formed at both ends of the plate fin. 5. An extruding step of forming plate fins having heat receiving portions integrally formed at both ends by extruding an aluminum material; a cutting step of cutting the length of the plate fins to a predetermined dimension; A plate fin arranged in parallel in the side direction, a superimposing step of arranging the adjacent heat receiving sections in parallel with each other and superimposing, and a joining step of joining the adjacent heat receiving sections formed on the plate fin to each other, A method for manufacturing a heat sink, comprising: 6. The method for manufacturing a heat sink according to claim 5, wherein, after the joining step, a dividing step of cutting a fin portion formed on the plate fin in a pushing direction at a predetermined position is performed. Heat sink manufacturing method.