JP2001024115A - Fin material for heat sink and joint structure thereof - Google Patents

Abstract

(57) [Summary] PROBLEM TO BE SOLVED: To achieve sufficient bonding with the processing accuracy of extrusion molding, to increase the total heat exchange area of the fin material, and to ensure the bonding of the base member and the fin material in a good thermal conductivity state. Provided are a fin material for a heat sink which can be easily formed into a joint structure simply by forcibly inserting a fin material into a base member, and a joint structure using the same. SOLUTION: An insertion groove of a box-shaped base member provided with an insertion groove for fitting a fin material has a height slightly larger than a cross section of the base member and has a cross-sectional shape of a curved line or a broken line. A joint structure in which the formed fin material is forcibly inserted so that the oxide on the fitting surfaces of both the base member and the fin material is stripped and the metal surfaces are joined.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-performance assembly using a small heat sink for various electronic devices, batteries, and other devices and appliances requiring heat removal from a heating element or an extruded member for a heat exchanger. TECHNICAL FIELD The present invention relates to a fin material for use, a coupling structure incorporating the fin material, and a method for producing them.

[0002]

2. Description of the Related Art In recent years, electronic devices such as personal computers and other office equipment have a large number of heating elements incorporated in a narrow space due to miniaturization, high density, and high performance. It has become necessary to forcibly exhaust heat. For this reason, it is normal for a heat sink to be incorporated in these electronic devices, and thus a small, high-performance forced air-cooled heat sink, which does not hinder the miniaturization of the electronic device, is required. Most of these heat sinks are usually made of aluminum material having high thermal conductivity, low cost, excellent workability, and light weight. On the other hand, since it is known that the cooling efficiency of the heat sink is greatly affected by the total area of the fin materials provided on the coupling structure (heat sink), various proposals for increasing the total area of the fin materials have been made. . That is, many heat sinks have been proposed in which a large number of fins are provided inside the base member of the heat sink to increase the heat exchange area.

For example, as shown in FIG. 4, there is a heat sink in which the inside of a base member is partitioned by fin materials having a linear cross section at regular intervals, such as harmonica. This type of heat sink has excellent productivity because it can be manufactured by integral extrusion. However, since it depends on extrusion technology, the distance between the fins and the thickness of the fins are limited, and the pitch between the fins is smaller than 8 mm. It is difficult to manufacture a heat sink, and the heat sink for electronic equipment is often oversized. To this end, a method has been proposed in which the base member and the fin material are separately manufactured and brazed, thereby narrowing the fin spacing and increasing the total fin area. Although this method achieves its goal when it is performed reliably, it is expensive, requires large-scale capital investment, and requires technically advanced techniques,
Even if the superficial bonding is successful, the formation of voids cannot be prevented internally, and it is difficult to complete the bonding.

As shown in FIG. 5, a projection is provided on the fin material and a coupling groove is provided on the base member so that the coupling groove is narrower than the projection of the fin material. There is a press-fit type proposal in which the oxide surface of the joint surface is peeled off by press-fitting the projections of the fin material so that the connection can be reliably performed. In this type of heat sink, the processing accuracy of the projections of the fin material and the coupling grooves is required to be high, so that mere extrusion processing tends to cause variations in performance, and the press-fitting cost is also high. In addition, there is a proposal in which the shape of the coupling groove of the base member is press-fitted into a curved shape with respect to the linear shape of the projection of the fin material so that the surfaces of the two surfaces always nip together. It is difficult to apply this type to a type in which the fin material is fitted between the upper and lower members. As shown in FIG. 6, there is a proposal to secure the connection by caulking the projection of the fin material and the fitting portion of the base member. However, not only is the cost of the caulking process high, but also caulking of both upper and lower surfaces is performed at the same time. Is technically difficult, and the precision of the extruded material does not necessarily require the precision of this joint, but is unsuitable in terms of productivity and cost.

[0005]

SUMMARY OF THE INVENTION According to the present invention, sufficient bonding can be performed with the processing accuracy of extrusion molding, the total heat exchange area of the fin material is large, and the heat conductivity of the base member and the fin material is good. An object of the present invention is to develop a fin material for a heat sink that can be easily connected by simply forcibly inserting a fin material into a base member, and a connecting structure using the same.

[0006]

According to the present invention, there is provided [1] a cross-sectional shape of a fin material to be fitted and assembled to a box-shaped base member.
A fin material structure characterized by having a curved or broken line shape, [2] the insertion groove of the box-shaped base member provided with the insertion groove for fitting the fin material is slightly smaller than the cross section of the base member. The fin material having a large height and a cross-sectional shape formed of a curved line or a broken line is stripped of the oxide on the fitting surface of both the base member and the fin material, and the metal surfaces are joined to each other. A method for manufacturing a joint structure, which comprises forcibly inserting

[3] A coupling structure in which a fin material having a cross-sectional shape of a curved or broken line is fitted inside a box-shaped base member. [4] The fin material is formed of a box-shaped base member. Hollow, double, with a height slightly larger than the cross-section and whose cross-sectional shape is composed of curves or broken lines
The coupling structure according to the above [3], which is a tube-shaped fin material having a triple, small room, or small room structure having small projections, [5] a base member in which a fin material is inserted into a box-shaped base member. The coupling structure according to [3] or [4], which is chamfered to substantially the same height as the cross section of [6], wherein a box-shaped base member is provided with an insertion groove for fitting a fin material. The binding structure according to the above [3],

[7] An electronic apparatus characterized in that the coupling structure according to any one of the above [3] to [6] is used as a heat sink or a heat exchanger, and [8].
A fin material having a height sufficiently larger than the cross section of the box-shaped base member is manufactured by extrusion, and the height is slightly larger than the cross section of the base member in order to impart elasticity in the height direction. The above-mentioned problem has been solved by developing a method of manufacturing a fin material for a heat sink, characterized in that the cross-sectional shape has a curved line or a broken line.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION As the material of the joint structure of the present invention, it is possible to obtain the effect by using any material metal as the structure, but in principle, it is lightweight,
Aluminum or an aluminum alloy having excellent workability and thermal conductivity and having sufficient rigidity as a heat sink material is used. In the present invention, the fin material used for the joint structure has a very unique shape in which the cross-sectional shape of the fin material fitted and assembled to the box-shaped base member has a curved or broken line shape, and the fin material has a spring shape. It imparts the property to ensure the bonding state with the base member, increases the surface area of the fin, and improves the performance as the bonding structure.

Hereinafter, the present invention will be described in detail. FIG. 1 is a cross-sectional view of the joint structure of the present invention, and FIG. 2 is an enlarged view of the joint. As the fin material 2 of the present invention, a fin raw material having a height sufficiently larger than the coupling surface interval L of the box-shaped base member 1 to be fitted is used. This extra height depends on the shape of the cross-section curve or broken line of the fin material, so there is no definite value. However, in order to impart spring properties to the fin material 2 in the height direction, as a fin raw material, Preferably, at least 5%, more preferably at least 10%, is greater than the height of the connection plane distance L of the box-shaped base member 1. Here, the spring property means that when the fin material (after the cross-sectional shape is a curved line or a broken line) is strongly compressed in the height direction, the cross-section takes the shape of a curved line or a broken line, thereby increasing the height. It refers to the extent that it can be slightly flexed in the direction and can be changed slightly, and does not mean that a large elasticity like a spring is provided. Of course, by increasing the curve or the polygonal line, it is possible to increase the total surface area of the fin material and to provide a large spring property. However, it is easy to make the coupling structure to keep the spring property within a necessary limit. .

Since the height of the fin material after the cross-sectional shape is a curved line or a broken line varies depending on the strength of the box-shaped base member, the spring property given to the fin material, the mechanical properties of the fin material, etc. Although it is not possible, it is necessary that the gap is at least larger than the distance between the fitting surfaces of the box-shaped base members, and that galling occurs between them due to forced insertion. A fin material having a height of at least 0.5%, preferably at least 0.5%, more preferably at least 0.8% is used.

The shape of the fin material is not particularly limited as long as the cross-sectional shape having a spring property has a curved line or a broken line, but FIG. 3 shows (1) a hollow shape, (2) a flat shape,
(3) Double hollow shape, (4) Triple hollow shape,
(5) Flat with projection, (6) Small room with small projection, (7)
Although not limited to the examples, various shapes such as an X type and a (8) polygonal line type are conceivable. In order to increase the efficiency of assembling the fin material and the box-shaped base member, two or more, several or several tens of fin materials are combined to form a hollow fin material. Bonded to another plate material (a material that can be bonded to a box-shaped base member)].

It is preferable that the upper and lower end surfaces of the fin material on the insertion side of the box-shaped base member are chamfered (or obliquely cut) in accordance with a fitting surface interval of the box-shaped base member. This chamfering facilitates fitting of the fin material, and can increase the efficiency of assembly.

It is preferable that the box-shaped base member of the present invention is provided with a fitting groove so as to facilitate the positioning of the insertion of the fin material. As a result, the height of the fin material is determined based on the height of the base member (L + α) based on the distance between the fitting surfaces of the fitting grooves. The shape of the groove can be a triangular groove or a square groove according to the joint surface of the fin material.However, by forcibly inserting the fin material, the joint surface of the fin material is in a galling state, and the base member and the fin material are There is no particular limitation as long as the oxide film on the mating surfaces of the two can be stripped off and the new metal surfaces can be joined together. By bonding the new metal surfaces in this manner, the heat conductivity between the box-shaped base member and the fin material can be maintained high, and the heat exchange capacity of the bonded structure can be maintained high.

Since the joint structure of the present invention mainly uses an aluminum material which is very easily oxidized, the joint surface between the base member and the fin material is covered with aluminum oxide having poor thermal conductivity. The aluminum oxide film is peeled off by forcibly inserting a fin material whose height is slightly larger than the space between the fitting surfaces of the box-shaped base member, and the metal is joined to each other to form a joint structure having high heat exchange efficiency. It is assumed that.

[0016]

The fin material of the present invention is inserted into a box-shaped base member, has a spring-like cross-sectional shape of a curved line or a polygonal line, and is formed from the fitting surface interval of the box-shaped base member. Because it is slightly higher, when it is forcibly inserted into the base member, the oxide film on the joining surface of the two is peeled off, the metal surfaces are directly joined, and heat conduction between the fin material and the base member Can be maintained high, resulting in a joint structure having high thermal efficiency. In addition, due to the spring property, the joint surface is constantly pressed, so that even when thermal expansion and thermal contraction are repeated, an unbroken connection is provided. Further, since the cross-sectional shape of the fin material is a curved line or a broken line, the total area of the fin material can be increased, and the thermal efficiency can be further increased. Since the fin material of the present invention utilizes the spring property, the molding precision is sufficient to be the processing precision of the extrusion molding, and it is sufficient to simply insert the fin material into the base member. is there.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a coupling structure of the present invention.

FIG. 2 is an enlarged view of a joint of the joint structure of the present invention.

FIG. 3 is an illustration of a fin material that can be used in the joint structure of the present invention.

FIG. 4 is a sectional view showing an example of a conventional heat sink (integrated extrusion type).

FIG. 5 is a cross-sectional view of another example of a conventional heat sink (press-fit type).

FIG. 6 is a cross-sectional view of another example of a conventional heat sink (caulking type).

[Explanation of symbols]

 Reference Signs List 1 base member 2 fin material L coupling surface interval of box-shaped base member

Continued on the front page (72) Inventor Makoto Fujioka 224 Kaiyamacho, Sakai City, Osaka Prefecture Showa Aluminum Co., Ltd. F-term (reference) 5F036 AA01 BB05 BC01

Claims (8)

[Claims] 1. A fin material structure, wherein a cross-sectional shape of a fin material fitted and assembled to a box-shaped base member has a curved or broken line shape. 2. The insertion groove of a box-shaped base member provided with an insertion groove for fitting a fin material has a height slightly larger than a cross section of the base member and has a cross-sectional shape of a curved line or a broken line. Wherein the oxide on the fitting surfaces of both the base member and the fin material is stripped off, and the metal surfaces are forcibly inserted so that the metal surfaces are bonded to each other. How to make the body. 3. A coupling structure, wherein a fin material having a curved or polygonal cross section is fitted inside a box-shaped base member. 4. The fin material has a height slightly larger than the cross section of the box-shaped base member, and forms a hollow, double, triple, small chamber or small projection having a cross-sectional shape formed by a curved line or a broken line. The joint structure according to claim 3, wherein the joint structure is a tubular fin material having a small room structure. 5. The coupling structure according to claim 3, wherein the insertion side of the fin material into the box-shaped base member is chamfered to a height substantially equal to a cross section of the base member. 6. The coupling structure according to claim 3, wherein an insertion groove for fitting a fin material is provided in the box-shaped base member. 7. An electronic apparatus, wherein the coupling structure according to claim 3 is used as a heat sink or a heat exchanger. 8. A fin material having a height sufficiently larger than the cross section of the box-shaped base member is manufactured by extrusion, and the fin material is formed with a higher height than the cross section of the base member in order to impart elasticity in the height direction. A method of manufacturing a fin material for a heat sink, wherein a cross-sectional shape having a slightly larger height is a curved line or a broken line.