JPH08181258A - Heat sink - Google Patents

Abstract

PURPOSE: To obviate the necessity to cut and flatten the lower end face of a substrate after soldering, and also, prevent the drop of heat conductivity by soldering material, and besides, facilitate the setting work before soldering. CONSTITUTION: A heat sink 1 is made by stacking a heat sink constituent 2 made of aluminum extrusion material consisting of a fin part 5 and a board constituent 6. A recess 7 for retaining solder material 8 is provided at the right side face of the board constituent 6. A projection 11 for engagement is provided at the left side face of the upper reinforcing part 9 at the top of the fin part 5, and a recess 12 for engagement to engage with this projection 11 for engagement is provided at the right side face.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat sink (radiator) used for cooling transistors and the like.

[0002] In this specification, "aluminum" includes aluminum alloy.

[0003]

2. Description of the Related Art Fins and a fin assembly are formed by laminating a heat sink structure made of an extruded aluminum material, which is composed of a fin and a base part connected to the lower end of the fin part, and brazing the base parts of adjacent heat sink parts together. A heat sink having a body and a heating element mounting substrate connected to the lower end of the body is conventionally known (see Japanese Utility Model Publication No. 5-47473 and Japanese Patent Application Laid-Open No. 6-216551).

In these heat sinks, a notch for inserting a brazing material is provided at the lower end of either one of the facing surfaces of the adjacent substrate constituent parts.

[0005]

In the above-described conventional heat sink, during brazing, the brazing material inserted in the notch flows downward, and unevenness is generated on the lower end surface of the substrate on which the heating element is mounted, resulting in cutting after brazing. There is a problem that it needs to be processed to be flat, and that when the heating element is attached to the lower end surface of the substrate, the heating element is in direct contact with the brazing material, so that the thermal conductivity is lowered. Further, when the heat sink constituents are stacked, it is difficult to position the heat sink constituents with each other, which makes it difficult to perform setting work before brazing.

An object of the present invention is to eliminate the need for cutting and flattening the lower end surface of a substrate after brazing, preventing deterioration of thermal conductivity due to a brazing material, and setting work before brazing. It is to provide a heat sink that is easy to remove.

[0007]

In a heat sink according to the present invention, a heat sink structure made of an extruded aluminum material, which is composed of a fin portion and a substrate constituent portion connected to the lower end of the fin portion, is laminated, and the substrate constituent portions of adjacent heat sink constituent members are adjacent to each other. In the heat sink in which the fin assembly and the heating element mounting substrate connected to the lower end of the fin assembly are formed by brazing, the brazing filler metal is held on either one of the facing surfaces of the adjacent board components. The groove is provided, and the fitting convex portion is provided on one of the facing surfaces of the adjacent fin portions, and the fitting concave portion is provided on the other surface.

[0008]

According to the heat sink of the present invention, since the brazing material holding groove is provided on either one of the facing surfaces of the adjacent substrate constituent portions, the brazing material flows downward during brazing. As a result, no unevenness is formed on the lower end surface of the substrate on which the heating element is attached, and moreover, when the heating element is attached to the lower end surface of the substrate, the heating element does not come into direct contact with the brazing material. In addition, since the fitting convex portion is provided on one of the facing surfaces of the adjacent fin portions and the fitting concave portion is provided on the other surface of the adjacent fin portion, when stacking the heat sink constituents, the adjacent heat sink constituents are stacked. The heatsink structures can be positioned by fitting them together.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. In this specification, upper, lower, left, and right mean the upper, lower, left, and right in FIG.

FIG. 1 shows a heat sink (1) according to the present invention.
In the first embodiment, the heat sink (1) is formed by laminating the heat sink constituents (2) made of aluminum extruded profile in layers.

As shown in FIG. 2, the heat sink structure (2) has a fin portion (5) composed of two plate-like fins (5a) provided at a predetermined interval and a fin portion (5). It is composed of a board constituting part (6) for connecting the lower ends of the plate-shaped fins (5a).

A brazing filler metal holding groove (7) opening to the right is provided on the right side surface of the substrate constituting portion (6). A brazing material (8) such as a brazing sheet or filler metal is inserted into the brazing material holding groove (7). The brazing material holding groove (7)
For example, the width is 18 mm and the depth is 1.0 mm.
(8) has a width of 17.5 mm and a thickness of 1.0 mm, for example.

The fin portion (5) has two plate-like fins (5a).
An upper reinforcing portion (9) connecting the upper ends of the two and two intermediate reinforcing portions (10) connecting the intermediate portions of the two plate fins (5a) are provided. On the left side of the upper reinforcement (9), the fitting ridge
(11) is provided, and on the right side surface of the upper reinforcing portion (9), there is provided a fitting concave groove (12) which fits into the fitting convex strip (11).

The board constituting portion (6), the upper reinforcing portion (9) and each of the intermediate reinforcing portions (10) are slightly projected to the left and right of the two plate fins (5a), and the heat sink constituting body (6) When 2) are stacked in layers, these board components (6)
The upper reinforcing portion (9) and the intermediate reinforcing portions (10) are abutted against each other, so that a predetermined gap is formed between the adjacent plate-shaped fins (5a).

[0015] Upper reinforcement (9) and each intermediate reinforcement (10)
Has a function of reducing the deformation of the plate fin (5a) and holding the two plate fins (5a) in parallel to each other,
Therefore, the height of the plate fin (5a) can be increased.

The heat sink (1) is manufactured as follows.

First, the A6063 material is used to form a heat sink.
An extruded profile having the cross-sectional shape of (2) is manufactured. By cutting this extruded shape into the required length, the required number of heat sink components (2) having the required length can be obtained. These heat sink structures (2) are stacked in layers and each mating ridge (1
The 1) and the fitting concave grooves (12) are fitted together, and the brazing material (8) is inserted into the brazing material holding concave grooves (7). Finally,
After fixing with a jig, braze by vacuum brazing. As a result, a fin assembly (3) in which a plurality of plate-shaped fins (5a) are arranged in parallel with each other, and a substrate that is connected to the lower end of the fin assembly (3) and has a heating element attached to the lower end surface (4a)
A heat sink (1) consisting of (4) is obtained.

The joining method is not limited to vacuum brazing, but furnace brazing in an inert atmosphere may be used.

The height of the heat sink structure (2) is 100
~ 180 mm, width is about 10 mm, depth is 1
It is set to about 00 to 300 mm. Then, for example, 50 heat sink structures (2) are used to form a heat sink (1) having a width of 500 mm. Although it is possible to integrally extrude the entire heat sink to manufacture a heat sink having a width of 500 mm, the cost of the extrusion die becomes very high as the extrusion width becomes wider. On the contrary,
Since each heat sink structure (2) has a narrow width, the cost of the extrusion die can be reduced, and the manufacturing cost of the heat sink (1) can be reduced.

At the time of manufacturing the above heat sink (1),
Since the brazing material (8) is held in the brazing material holding groove (7), the molten brazing material (8) does not flow downward during brazing. Therefore, the bottom surface (6a) of the board forming part (6) of each heat sink assembly (2) allows the flat bottom surface of the board
(4a) is formed. Therefore, post-processing such as mechanical cutting for eliminating the unevenness of the lower end surface (4a) of the substrate is unnecessary. Also,
When stacking the heat sink structures (2) in layers, the heat sink structures (2) can be positioned by fitting the adjacent heat sink structures (2) together. Therefore, a large-scale fixing jig is not required, and setting work before brazing can be easily performed.

The brazing material (8) is a brazing material holding groove (7).
It is not exposed to the bottom surface (4a) of the substrate because it is held by the heat sink (1), and when the heating element is attached to the bottom surface (4a) of the heat sink (1), the heating element directly contacts the brazing material (8). The thermal conductivity does not decrease due to the brazing filler metal (8).

Although not shown, the height is 200 mm.
When manufacturing a large heat sink that exceeds the heat sink, use a heat sink structure (2) whose height is 1/2 of the heat sink height (2) as shown in Fig. 1.
Two pieces of the heat sink (1) may be stacked upside down on top of each other, and the upper reinforcing portions (9) of the two heat sinks (1) may be joined by argon welding. By doing this, the fin (5a) height of the heat sink structure (2)
It is not necessary to manufacture a die for extrusion, and a large heat sink can be manufactured at low cost.

The heat sink (1) is usually formed by a heat sink structure (2) having the same size so that it is rectangular when seen from a plane, but the cutting length when cutting the extruded profile is changed to be different. It is possible to easily obtain various shapes such as U-shape, T-shape, L-shape, etc. when viewed from a plane by manufacturing the heat sink structure (2) having the depth dimension and combining these variously. It is possible to cope with a heating element having the shape of. In particular, for large AC-DC inverters with over 100-1000 amperes,
There is a tendency for multiple heating elements to be used, and even in such a case, it is easy to make a substrate area suitable for the size and wattage of the heating element, and a heat-sink shape that is economically efficient can be obtained with the same extruded shape. The material can be used and chosen arbitrarily.

FIG. 3 shows a second embodiment of the heat sink structure (22).

The heat sink structure (22) shown in the figure is a substrate structure part that connects the fin portion (25) consisting of two plate-shaped fins (25a) and the lower ends of the two plate-shaped fins (25a). It consists of (26).

A brazing filler metal holding groove (27) opening rightward is provided on the right side surface of the substrate constituting portion (26).

The fin portion (25) includes two plate-shaped fins (25
a) an upper reinforcing part (29) connecting the upper end part of a) and two intermediate reinforcing parts (30) connecting the middle parts of the two plate fins (25a)
Are provided. A brazing filler metal holding groove (33) opening rightward is provided on the right side surface of the upper reinforcing portion (29). Fitting ridges (31) are provided on the left side surface of each intermediate reinforcing portion (30),
On the right side of the same, there is a fitting groove that fits into this fitting ridge (31).
(32) is provided.

This heat sink structure (22) is overlaid in layers to fit each fitting convex strip (31) and each fitting concave groove (32), and each brazing filler metal holding groove (27). A sink tank is obtained by inserting brazing filler metal into each of (33), fixing them with a jig, and then joining them by vacuum brazing.
In this think tank, adjacent heat sink components (2
Since fitting and brazing are performed at two places each between 2), the positioning accuracy at the time of stacking is improved and the joining is more improved as compared with the heat sink (1) of the first embodiment. It will be certain.

FIG. 4 shows a third embodiment of the heat sink structure (42).

The heat sink structure (42) shown in the figure is a substrate structure part that connects the fin portion (45) consisting of three plate-like fins (45a) and the lower ends of the three plate-like fins (45a). It consists of (46).

A brazing filler metal holding groove (47) opening rightward is provided on the right side surface of the substrate forming portion (46).

The fin portion (45) includes three plate-shaped fins (45
The upper reinforcing part (49) connecting the upper end of (a) and the two intermediate reinforcing parts (50) connecting the intermediate parts of the three plate fins (45a).
Are provided. On the left side surface of the upper reinforcing portion (49), a fitting ridge (51) is provided, and on the right side surface of the upper reinforcing portion (49),
A fitting concave groove (52) that fits into the fitting convex strip (51) is provided.

The number of the plate-like fins (5a) (25a) (45a) of each heat sink structure (2) (22) (42) is not limited to two or three, but one or four or more. May be
When the heat sink is composed of two or three heat sink components (2) (22) (42) of plate fins (5a) (25a) (45a), the heat sink consists of one heat sink component. Compared to the heat sink structure (2) (22) (42)
It is possible to reduce the manufacturing cost by reducing the man-hours required for cutting, the man-hours required for cutting the extruded profile, the man-hours required for superposing the heat sink structure, and the man-hours required for brazing.

[0034]

According to the heat sink of the present invention, during brazing, unevenness does not occur on the lower end surface of the substrate on which the heating element is attached. Therefore, it is necessary to cut and flatten the lower end surface of the substrate after brazing. Absent. Moreover, when the heating element is attached to the lower end surface of the substrate, the heating element does not come into direct contact with the brazing material, so that deterioration of thermal conductivity due to the brazing material is prevented. Further, when the heat sink constituents are stacked, the heat sink constituents can be positioned by fitting adjacent heat sink constituents together, so that the setting work before brazing can be easily performed.

[Brief description of drawings]

FIG. 1 is a front view showing a first embodiment of a heat sink according to the present invention.

FIG. 2 is a front view showing one heat sink component and a brazing filler metal constituting the heat sink of the first embodiment.

FIG. 3 is a front view showing a second embodiment of the heat sink structure.

FIG. 4 is a front view showing a third embodiment of the heat sink structure.

[Explanation of symbols]

 (1) Heat sink (2) (22) (42) Heat sink assembly (3) Fin assembly (4) Board (5) (25) (45) Fin section (6) (26) (46) Board section ( 7) (27) (47) Brazing material retaining groove (8) Brazing material (11) (31) (51) Mating ridge (12) (32) (52) Mating groove

Claims (1)

[Claims] 1. A heat sink structure body (2) made of an extruded aluminum material, comprising a fin part (5) and a board structure part (6) connected to a lower end of the fin part (5) is laminated, and a board structure of adjacent heat sink structure bodies (2). The heat sink (1) on which the fin assembly (3) and the heating element mounting substrate (4) connected to the lower end of the fin assembly (3) are formed by brazing the parts (6) together.
In, the brazing filler metal (8) holding concave groove (7) is provided on one of the facing surfaces of the adjacent substrate constituent parts (6), and A heat sink characterized in that a fitting convex portion (11) is provided on one side and a fitting concave portion (12) is provided on the other side.