JPH09116054A - Heat sink - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent clogging, compensate deterioration of performance because of reduction in the heating area caused by increase in the fin spacing, and reduce deterioration of performance even after a lapse of time, by specifying the fin spacing and slit width in a heat sink. SOLUTION: A heat sink component body 2 includes a fin portion 5a made of two panel-like fins 5a, and a substrate component portion 6 connecting lower ends of the two panel-like fins 5a. In each fin 5a, slits 3 are provided in parallel with one another and with spacing in a direction of air flow. The fin spacing of the panel-like fins 5a is set to not less than 2mm and not more than 7mm, and the slit width is set to not less than 2mm and not more than 8mm. Thus, clogging may be prevented without deteriorating performance. Also, by setting the pitch of the slits to not less than 15mm and not more than 25mm, thermal resistance may be reduced and therefore performance of the heat sink may be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention, for example, in a machine tool or the like, is mounted on a semiconductor element such as a transistor or a thyristor and is cooled by cooling air forced to flow by a blower to radiate the heat of the semiconductor element. Regarding heat sink.

[0002]

2. Description of the Related Art For example, in a machine tool or the like, as a heat sink used for radiating heat of a semiconductor element such as a transistor or a thyristor, a plate-shaped fin having parallel slits provided at intervals is conventionally used. It is more known (see JP-A-5-3272).

[0003]

In a heat sink used for a machine tool or the like, clogging of dust, oil, etc. must be taken into consideration, and the performance of the heat sink will not reach the range where the influence of pressure loss does not appear extremely. The fin interval is preferably small. If the fin interval is too small, there is a problem in that the initial performance is good, but the performance is extremely deteriorated over time. For clogging, it is effective to increase the fin spacing, but the heat transfer area is reduced by that amount and the initial performance is reduced. In such a situation, it is necessary to provide a heat sink with good initial performance and less deterioration in performance over time by providing an optimal slit, but such a heat sink has hitherto been known. Didn't.

An object of the present invention is to provide a heat sink having good initial performance and having little deterioration in performance over time.

[0005]

A heat sink according to the present invention is a heat sink in which plate-like fins having parallel slits are provided at intervals, and the fin intervals are two.
The slit width is 2 mm or more and 8 mm or less.

The slit pitch is 15 mm or more and 25
mm or less.

The fin spacing is 4 mm or more and 5 mm
The following is more preferred.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. In the following description, the upper and lower sides refer to the upper and lower sides of the drawing, but the upper and lower sides are for convenience, and the upper and lower sides may be reversed or may lie down.

FIG. 1 shows a heat sink (1) of the present invention. The heat sink (1) is formed by stacking aluminum extruded heat sink components (2) in layers. On the underside of this heatsink (1),
Semiconductor elements such as transistors and thyristors are attached, and cooling air is blown in a direction parallel to the heat sink structure (2) by a blower arranged in front of or behind the heat sink (1).

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). The wind flows in parallel with the plate fins (5a), and the cooling air passage is provided between the two plate fins (5a) of each heat sink structure (2) and between the adjacent heat sink structures (2). Has been made. As will be described later, each fin (5a) is provided with slits (3) that are optimized as a result of various tests and are arranged in parallel at intervals in the wind flow direction. On the right side of the board component (6), a brazing filler metal holding groove (7) opened to the right
Is provided. The fin portion (5) has an upper reinforcing portion (9) connecting the upper ends of the two plate fins (5a) and an intermediate reinforcing portion (connecting an intermediate portion of the two plate fins (5a) ( 10) and are provided. On the left side of the upper reinforcement (9), the fitting ridge
(11) is provided on the right side surface of the upper reinforcing portion (9) when the heat sink assembly (2) is connected to the fitting ridge (1).
A fitting groove (12) which fits in (1) is provided. The board structure part (6), the upper reinforcing part (9) and the intermediate reinforcing part (10) are 2
The plate fins (5a) are slightly projected to the left and right, and when the heat sink structure (2) is stacked in layers, these board structure parts (6) and upper reinforcement parts (9) The intermediate reinforcing portions (10) are abutted against each other, so that a predetermined gap is formed between the adjacent plate-shaped fins (5a).

FIG. 3 is a graph showing the results of measuring the thermal resistance of the heat sink by changing the fin spacing (d) variously for the conventional heat sink without slits. As shown in FIG. When d) is 3 mm, the initial performance is good, but over time, the thermal resistance rapidly increases and the performance deteriorates. Also, the fin spacing (d) is 6m
The m-type one has poor initial performance, and as a result, the life of the semiconductor to which the heat sink is attached is shortened. On the other hand, when the fin spacing (d) is 4.5 mm, the initial performance is slightly inferior to that when the fin spacing (d) is 3 mm, but the performance does not deteriorate so much over time. doing. That is, the fin spacing (d) should be reduced in order to reduce the performance degradation over time.
4 mm or more is required, and it can be seen that the optimum fin spacing (d) without slits is 4 mm or more and 5 mm or less.

FIG. 4 is a graph showing the results of measuring the heat resistance of the heat sink (1) shown in FIG. 1 with various slit widths (b) changed, and as shown in FIG. While the slit width (b) is small, the slit width
As (b) is increased, the thermal resistance decreases and the performance improves, but when the slit width (b) exceeds 5 mm, the thermal resistance increases and the performance begins to decline. That is, if the slit width (b) is too small, the performance will be poor because the film will not be cut sufficiently, and if the slit width (b) is too large, the heat transfer area will be too small and the performance will be poor. It can be seen that the width (b) is 2 mm or more and 8 mm or less.

FIG. 5 shows the slit width (b) of the heat sink (1) shown in FIG.
It is a graph showing the results of measuring the thermal resistance of the heat sink with various changes in (p) .As shown in the figure, while the slit pitch (p) is small, it increases as the slit pitch (p) increases. Then, the thermal resistance decreases and the performance improves, but when the slit pitch (p) exceeds 20 mm, the thermal resistance increases and the performance begins to deteriorate. That is, if the slit pitch (p) is too small, the heat transfer area becomes too small and the performance deteriorates.If the slit pitch (p) is too large, the boundary layer develops between the slits (3). The performance is poor and the optimum slit pitch (p) is
It can be seen that it is 15 mm or more and 25 mm or less.

FIG. 6 shows the fin pitch (p) without slits.
Is a graph showing the results of measuring the thermal resistance between a conventional heat sink having a width of 4.5 mm and a heat sink of the present invention having a slit (3) and a fin pitch (p) of 5.5 mm by changing the front wind speed. As shown in the figure, in the heat sink (1) of the present invention, the fin pitch (p) is 5.5 mm.
It can be seen that the performance is almost the same as that of the conventional heat sink having the fin pitch (p) of 4.5 mm without the slit, though it is large.

The heat sink (1) is manufactured as follows.

First, the heat sink structure is made of A6063 material.
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. Next, each heat sink structure (2) is subjected to press working to provide the optimum slit (3) as described above. These heat sink structures (2) are stacked in layers to fit each fitting ridge (11) and each fitting groove (12), and to each brazing material holding groove (7) respectively. Insert brazing material such as brazing sheet or filler metal. Finally, after fixing with a jig, it is brazed by vacuum brazing. As a result, a heat sink (1) having a plurality of plate-shaped fins (5a) having parallel slits (3) provided at intervals is obtained.

The height of the heat sink structure (2) is 50 to 50.
About 180 mm, width is about 10 mm, depth is 10
It is about 0 to 400 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 other hand, 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.

The upper reinforcing portion (9) and the intermediate reinforcing portion (10) are
The deformation of the plate fins (5a) is reduced so that the two plate fins (5a
It has a function of holding a) so that they are parallel to each other, so that the height of the plate fin (5a) can be increased.

When the height of the plate fins (5a) is low, there is no problem even if the intermediate reinforcing portion (10) is omitted. An example of such a fin structure (20) is shown in FIG. 7 is the same as that of FIG. 2 except for the intermediate reinforcing portion, which are denoted by the same reference numerals and the description thereof will be omitted.

In FIGS. 2 and 7, the slit (3)
Has two stages above and below, but the same effect can be obtained even if the slit is lengthened to one stage.

As shown in FIG. 1, the heat sink (1) is usually formed by a heat sink structure (2) of the same size so that it is rectangular when viewed from a plane. The heat sink structure (2) with different depth dimensions is manufactured by changing the cutting length of the, and various combinations of these are used to form the heat sink (21) which is U-shaped when viewed from the plane as shown in FIG. As shown in FIG. 9, various shapes such as a T-shaped heat sink (22) when viewed from the plane or an L-shaped heat sink when viewed from the plane can be easily obtained. Therefore, it is possible to cope with heating elements of various shapes. Especially 100 to 10
Large-sized ones such as AC-DC inverters exceeding 00 amps tend to have a plurality of heating elements. Even in such a case, it is possible to make a substrate area suitable for the size and watt value of the heating elements. An easy and economically efficient heat sink shape can be selected using the same extruded profile and arbitrarily.

[0022]

According to the heat sink of the present invention, the fin interval is set to 4 mm or more to prevent clogging, and the slit width is set to 2 mm to 8 mm inclusive, so that heat transfer associated with increasing the fin interval is achieved. Since the performance degradation due to the reduction of the area is compensated for, it is possible to take measures against clogging without degrading the performance.

By setting the pitch of the slits to 15 mm or more and 25 mm or less, the thermal resistance is reduced when the slit width is 2 mm or more and 8 mm or less, so that a heat sink with more excellent performance can be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a heat sink according to the present invention.

FIG. 2 is a perspective view showing an example of one heat sink structure that constitutes a heat sink.

FIG. 3 is a graph showing the difference in performance when the fin spacing of the heat sink is changed.

FIG. 4 is a graph showing a difference in performance when the slit width of the heat sink is changed.

FIG. 5 is a graph showing a difference in performance when the slit pitch of the heat sink is changed.

FIG. 6 is a graph showing a difference in performance between a heat sink according to the present invention and a conventional heat sink.

FIG. 7 is a perspective view showing another example of one heat sink structure that constitutes the heat sink.

FIG. 8 is a perspective view showing another example of the heat sink according to the present invention.

FIG. 9 is a perspective view showing still another example of the heat sink according to the present invention.

[Explanation of symbols]

 (3) Slit (5a) Plate fin (d) Fin spacing (b) Slit width (p) Slit pitch

Claims (2)

[Claims] 1. A plate fin having parallel slits (3)
In the heat sink with (5a) provided at intervals,
A heat sink characterized in that the fin spacing (d) is 2 mm or more and 7 mm or less and the slit width (b) is 2 mm or more and 8 mm or less. 2. The heat sink according to claim 1, wherein the pitch (p) of the slits (3) is 15 mm or more and 25 mm or less.