JP2003318339A - Heat sink and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat sink excellent in radiating efficiency and reduced in the manufacturing cost of the same. <P>SOLUTION: The heat sink 1 constituted of a base plate 2 and a radiating fin unit 10 on which a plurality of fins 3 are arranged at predetermined intervals is manufactured by brazing a radiating fin unit 10 constituted by connecting the singly worked fins 3 by calking and the base plate 2. The fin is preferably made of a profile singly worked by extrusion. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat sink for radiating heat generated in an electronic component or the like using an integrated circuit and a method for manufacturing the heat sink. Large heat sink and its manufacturing method.

[0002]

2. Description of the Related Art With the development of electronic equipment, miniaturization, high speed and high integration of integrated circuits such as LSI have been advanced, and along with this, the heat generated from the integrated circuits has increased. For this reason, a circuit is designed to reduce heat generation from the integrated circuit, and a heat sink is provided to promote heat dissipation from the electronic device to suppress malfunction of the integrated circuit due to heat generation.

The heat sink used for these is generally one having a structure in which fins for heat dissipation are provided on a substrate (base plate). The manufacturing method is roughly classified into a method in which the heat radiation fin and the substrate are manufactured as separate members and joined together, or a method in which the heat radiation fin and the substrate are integrally extruded.

However, in a heat sink that has been extruded and processed, there is less freedom in designing the fin specifications due to restrictions in extrusion processing. Therefore, the heat dissipating fin and the substrate are manufactured as separate members and joined together. The configured heat sink has been widely applied.

In particular, when the applied electronic device has a large amount of heat radiation such as a power supply element, a relatively large heat sink having a large capacity is required. In such cases,
The application of a heat sink composed exclusively of corrugated fin multi-tiered is under consideration.

FIG. 1 is a perspective view schematically showing a conventional corrugated fin two-stage heat sink. In the corrugated heat sink 1, the fins 3 formed by press working from one thin plate are
The fin 3 is housed in a concave fin case composed of the substrate 2 and the side wall 5, and the fin 3 is brazed to the substrate 2.
Further, in the heat sink shown in FIG. 1, in order to enhance the heat radiation effect, the fins stacked in two stages are adopted.

When manufacturing this heat sink 1,
First, it is necessary to form the fin case, but as shown in FIG. 1, one plate may be formed into a concave shape by cold bending, or the fin case may be divided into a substrate and two side plates into three parts. Alternatively, they may be joined and assembled into a concave shape. Next, the fins 3 are arranged in this fin case, the fins 3 and the substrate 2 are brazed, and a heat sink is manufactured.

The side surface 5 of the concave fin case mainly serves to protect the fins 3, and it is desirable to reduce the thickness thereof in order to increase the number of fins. On the other hand, the substrate 2 needs to have a uniform heat dissipation density so that the heat generated from the heat source can be dissipated by the entire fin 3.
In order to secure a predetermined thickness, it is desirable to braze a thick plate under the substrate.

In the corrugated heat sink described above,
In order to further increase the heat dissipation efficiency, it is necessary to manufacture a heat sink having more than two stacked layers. However, if a multi-layered structure is used, there will be certain restrictions on the performance improvement of the heat sink. That is, as described later, it is necessary to increase the thickness of the fin in order to ensure the performance of the multi-tiered heat sink.

On the other hand, as an alternative to the corrugated heat sink, there is used a fin-aligned heat sink in which fins are made of a thin plate or shaped material and a large number of heat radiation fins are aligned at a predetermined interval.

FIG. 2 shows, for example, Japanese Patent Laid-Open No. 11-17080.
FIG. 3 is a perspective view schematically showing a fin-aligned heat sink proposed in Japanese Patent Publication. As shown in FIG. 2, the heat sink 1 includes a rectangular substrate 2 having flat upper and lower surfaces.
And a first radiation fin 3 and a second radiation fin 4 arranged on the substrate 2. The first radiating fin 3 is made of a flat rectangular thin plate member whose end is bent by a pressing device to have a horizontal section 3a and a vertical section 3b and which has an L-shaped cross section. The second heat radiation fin 4 is made of a thin flat plate member having a rectangular shape.

The first radiating fin 3 is arranged on the substrate 2 so that the horizontal portion 3a thereof contacts the upper surface of the substrate 2, and the second radiating fin 4 has the lower end surface thereof on the substrate 2.
Is placed on the substrate 2 so as to be in contact with the upper surface of the substrate 2, and each contact portion is brazed to join the substrate 2 to the first heat radiation fin 3 and the second heat radiation fin 4.

At this time, the first radiation fins 3 are arranged so that the first radiation fins 3 face each other with the second radiation fins 4 interposed therebetween, and as many radiation fins as possible are arranged on the substrate 2. , To improve the heat dissipation efficiency.

[0014]

In recent years, the progress of high integration of integrated circuits has progressed remarkably, and the heat generated from the integrated circuits has increased accordingly. Therefore, further improvement of heat dissipation efficiency is required. become. In particular, since a heat sink used for a device such as a power supply element has a large heat radiation amount, it is required to further improve the heat radiation efficiency by using a relatively large heat sink.

In order to meet such requirements, the corrugated heat sink shown in FIG. 1 has certain restrictions if the heat radiation efficiency is to be further improved. In particular,
In order to increase the heat radiation area of the fin in order to improve the heat radiation efficiency, it is necessary to increase the height of the fin or increase the number of fins. It is difficult to secure the height and the number of fins.

Further, in order to secure the heat dissipation efficiency with a corrugated heat sink composed of multiple layers, it is necessary to increase the thickness of the fins. For example, when aluminum or aluminum alloy is used as the fin material, corrugated fins with two or less layers have a wall thickness of 0.5 m.
It can be applied with m to 0.6 mm, but for corrugated fins with three or more layers stacked, the wall thickness must be 1.0 mm to 2.0 mm.

However, in the corrugated heat sink, the fins cannot be made so thick due to restrictions in press working, so that the heat radiation efficiency cannot be improved and it is difficult to improve the performance of the heat sink.

Also in the fin-aligned heat sink shown in FIG. 2, there is a restriction on the pitch that can be secured due to the restriction of pressing the fins or the restriction of manufacturing the fins from the shape member, and the fins can be secured. There are difficulties in increasing the thickness and increasing the density.

Further, as a serious problem, when the fins are manufactured by a shape member or press working, the dimensions of the parts are not stable, so that a defect is likely to occur in the subsequent brazing process, which causes a defective joint. If a correction process such as cutting is added in order to stabilize the component size, the processing cost increases because the number of processed sheets is large.

The present invention has been made in view of the above-mentioned problems in the conventional heat sink, and provides a heat sink excellent in heat dissipation efficiency and a manufacturing method thereof, while reducing the manufacturing cost by improving the efficiency of fin processing. The purpose is to do.

[0021]

In order to solve the above-mentioned problems, the inventors of the present invention have made various studies on a fin processing method. As a result, for example, extrusion processing is used to form individual fins individually. Then, it was noted that the fins can be easily thickened and the production cost can be reduced by caulking and joining the fins to each other and further cutting the fins to a predetermined size to produce the heat radiation fin portion.

The present invention has been completed from such a point of view, and has as its gist the following methods of manufacturing a heat sink (1) and a heat sink (2). (1) A heat sink comprising a substrate and a radiation fin portion in which a plurality of fins are arranged at a predetermined interval, wherein the radiation fin portion formed by caulking and joining fins processed alone and the substrate are brazed Is a heat sink.

It is desirable that the above-mentioned fins are made of a single extruded shape. (2) A method of manufacturing a heat sink consisting of a substrate and a heat radiation fin portion in which a plurality of fins are arranged at predetermined intervals, wherein the fins are molded and processed individually, and then the individual fins are caulked and joined to each other, and then the predetermined size is obtained. The heat sink manufacturing method is characterized in that the heat radiating fin portion is manufactured by cutting into a rectangular shape, and the heat radiating fin portion and the substrate are brazed.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the conventional fin processing of a heat sink, regardless of whether it is a corrugated type or a fin-aligned type, fin fin thickening or fin dimensional accuracy is imposed because of fin processing or fin manufacturing restrictions. Had certain limits. For this reason, the heat sink of the present invention is characterized in that the fin manufacturing process is improved and the individually manufactured fins are combined to form the heat dissipation fin portion.
Specific embodiments of the present invention are described below with reference to FIGS.
It will be described based on. Note that the following description is based on the case where the individual fins are extruded by a single shape, but the heat sink of the present invention is not limited to this.

3A and 3B are views showing an extruded shape member in which individual fins constituting the heat sink of the present invention are formed as a single body, (a) showing a plan view of the extruded shape member, and (b) showing the extruded shape member. The side view of the material is shown. The fin 3 shown in FIG. 3 is used for a large heat sink, and the height of the profile is 100 mm to 3 mm.
It will be 00 mm. The planar shape of the extruded shape member that has been formed and processed by itself is composed of the fin body portion 11, the fin upper end portion 12 and the fin lower end portion 13, and is characterized by being vertically symmetrical.

Further, the fin upper end 12 and the fin lower end 13 provided at both ends of the fin body 11 are provided with a convex portion 14 and a concave portion 15, respectively.
The B dimension of the recess 15 is slightly smaller than the A dimension of 4. On the other hand, the side profile of the extruded profile shown in FIG. 3 (b) is rectangular, and the total length L is the side 5 of the fin case shown in FIG. 1 and the side 2 of the substrate 2 shown in FIG.
This corresponds to the width dimension of a.

The material of the extruded profile shown in FIG. 3 is not particularly limited, and examples thereof include aluminum, aluminum alloys, copper and copper alloys having excellent thermal conductivity.

FIG. 4 is a diagram showing a heat sink in which a heat radiating fin portion obtained by caulking and joining a single processed fin and a substrate are joined. The heat sink 1 of the present invention includes a convex portion 14 provided on the fin upper end portion 12 and the fin lower end portion 13.
And the recess 15 are inserted, and then the insertion direction (lateral direction)
The fins 10 are formed by caulking and connecting individual fins. By staking and joining the individual fins, the slack of the heat radiation fin portion 10 is eliminated.

Next, the heat radiating fin portion 10 caulked and joined.
The dimensions of the fins and the surfaces of the fin upper end 12 and the fin lower end 13 are adjusted by cutting. This improves the bondability by brazing. At this time, since the radiating fin portion 10 joined by caulking is cut,
Compared to cutting with a single fin, the man-hours can be significantly reduced.

The brazing filler metal 17 is inserted between the heat radiating fin portion 10 and the substrate 2 which are caulked together, and they are stacked and fired, so that the substrate 2 and the heat radiating fin portion 10 in which a plurality of fins are arranged at a predetermined interval. The heat sink 1 can be configured as follows. The brazing material 16 used at this time is selected depending on the material of the extruded shape material. For example, when the brazing material is aluminum or an aluminum alloy material, vacuum brazing is performed using an Al—Si alloy brazing material. desirable.

In the heat sink of the present invention, the individual fins are individually manufactured as a shape member, and caulking joining and cutting are performed. Therefore, by adjusting the number of caulking and changing the cutting length, the heat sink of the heat sink can be changed. The dimensions of the radiation fins can be changed as appropriate. Furthermore, since the thickness and pitch of the individual fins 13 can be appropriately selected, there is a high degree of freedom in dimensional design, and it is easy to increase the thickness of the individual fins and increase the density of the heat radiation fins.

5A and 5B are views showing an extruded shape member in which fins of another shape which compose the heat sink of the present invention are formed alone, (a) is a plan view of the extruded shape member, and (b) is a plan view. The side view of an extrusion profile is shown. FIG. 5 shows fins used for a medium-sized heat sink, and the height of the profile is about 100 mm or less. As shown in FIG. 5 (a), the planar shape of the extruded profile formed by itself is a fin body portion 11, a fin upper end portion 12 and a fin lower end portion 13 and is vertically symmetrical. .

Further, the fin upper end portion 12 and the fin lower end portion 13 provided at both ends of the fin body portion 11 are provided with a convex portion 14 and a concave portion 15, respectively, and the fin body portion 11 is provided with a spacer 16. Has been. On the other hand, the side shape of the extruded profile shown in FIG. 5 (b) is rectangular, and the total length L is the side surface 5 of the fin case shown in FIG.
And the width dimension of the side surface portion 2a of the substrate 2 shown in FIG.

FIG. 6 is a view showing a heat sink in which a heat radiating fin portion obtained by caulking and joining a fin of another shape machined alone is joined to a substrate. Similar to the heat sink 1 shown in FIG. 4, the protrusions 14 and the recesses 15 provided on the fin upper end portion 12 and the fin lower end portion 13 are inserted and then crimped in the longitudinal direction of the fins to form individual fins 3. The radiating fin portion 10 is configured by being connected. By staking and joining the individual fins 3, the radiating fin portion 10 is loosened.

Next, the heat radiating fin portion 10 is caulked and joined.
The fin size and the surfaces of the fin upper end portion and the fin lower end portion are adjusted by cutting. A heat sink 1 composed of the substrate 2 and the radiating fin portion 10 in which a plurality of fins are arranged at predetermined intervals by inserting a brazing material 17 between the radiating fin portion 10 and the substrate 2 which are caulked and stacking and firing them. Can be configured.

Spacer 16 provided on fin body 11
When the heat dissipating fins 10 are formed by caulking and joining the individual fins to each other, they have a function of contacting the fin body 11 and defining a predetermined fin pitch. As a result, the radiating fin portion 1 in which the plurality of fins 3 are arranged at predetermined intervals
0 can be manufactured accurately and easily.

Even in the heat sink 1 shown in FIGS. 5 and 6, since the individual fins 3 are individually manufactured as a shape member, and caulking and cutting are performed, the size of the heat radiating fin portion of the heat sink is changed. It is easy to do, there is a high degree of freedom in dimensional design, and it is easy to increase the thickness of individual fins and increase the density of heat dissipation fins.

[0038]

According to the heat sink of the present invention, the heat sink is manufactured by brazing the heat dissipating fin portion, which is formed by caulking and joining the fins machined alone, and the substrate. It is easy to achieve high density and high density, and excellent heat dissipation efficiency can be exhibited. Therefore, according to the manufacturing method of the present invention, it is possible to manufacture a heat sink having improved heat dissipation efficiency at a low manufacturing cost even for a medium-sized or large-sized one used for a power supply element or the like.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a configuration of a corrugated heat sink that has been conventionally used.

FIG. 2 is a diagram illustrating a configuration of a thin plate alignment type heat sink proposed in the prior application.

3A and 3B are diagrams showing an extruded shape member in which individual fins constituting the heat sink of the present invention are molded alone, (a) is a plan view of the extruded shape member, and (b) is a side surface of the extruded shape member. The figure is shown.

FIG. 4 is a diagram showing a heat sink in which a radiating fin portion obtained by caulking and joining a fin processed by itself and a substrate are joined together.

5A and 5B are views showing an extruded shape member in which fins of another shape constituting the heat sink of the present invention are formed by a single body, FIG. 5A is a plan view of the extruded shape member, and FIG. FIG.

FIG. 6 is a diagram showing a heat sink in which a radiating fin portion obtained by caulking and joining a fin of another shape processed by itself and a substrate are joined together.

[Explanation of symbols]

1: heat sink, 2, 2a: substrate 3, 4: Fin, 5: Side 10: Radiating fin portion, 11: Fin body portion 12: upper end, 13: lower end 14: convex, 15: concave 16: Spacer, 17: Brazing material

Claims (3)

[Claims] 1. A heat sink comprising a substrate and a radiating fin portion in which a plurality of fins are arranged at a predetermined interval, wherein the radiating fin portion constituted by caulking and joining fins processed alone is brazed to the substrate. A heat sink characterized by the above. 2. The heat sink according to claim 1, wherein the fin is a shape member extruded by itself. 3. A method of manufacturing a heat sink comprising a substrate and a radiation fin portion in which a plurality of fins are arranged at a predetermined interval, wherein the fins are molded and processed, and then the individual fins are caulked and joined to each other. A method for manufacturing a heat sink, characterized in that the heat radiation fin portion is manufactured by cutting to a predetermined dimension, and the heat radiation fin portion and the substrate are brazed.