JPH07105466B2 - Application structure of Ken Yamagata heat sink - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat sink applied structure for cooling a heating element by a heat sink.
In particular, it relates to a new application structure of a sword-shaped heat sink for cooling a heating element.

[0002]

2. Description of the Related Art In a plate fin group type heat sink having a conventional structure, the cooling convection flows only in a fixed direction due to the rectifying action of the fin group, the turbulent flow is less likely to occur, and the cooling efficiency is low. In order to improve it, various heat sinks including louver type have been proposed and put into practical use. However, due to recent advances in semiconductor technology, ICs, LSIs, etc. are becoming smaller and higher in density.
For the small heat sink corresponding to the above, there are many examples in which a downsized plate fin group heat sink as shown in the perspective view of FIG. In the figure, 11 is a plate fin group, 2 is a heat-receiving flat plate, 2-1 is a heat-receiving surface of a heat-receiving flat plate, 2-2 is a heat-dissipating surface of a heat-receiving flat plate, 3 is a heating element, and 4 arrows indicate cooling convection. -1 is a low temperature convection for cooling, and 4-2 is a high temperature convection after completion of cooling.

The mainstream of the improvement of current heat sinks for cooling ICs, LSIs, etc. is the practical application of a sword-shaped heat sink in which radiating pins are formed in a ridge shape on the radiating surface of a heat receiving flat plate having a heat receiving surface and a heat radiating surface. Is becoming. The improvement is to reduce the diameter and density of the pin to increase the heat transfer coefficient of the pin, improve the cross-sectional shape of the pin to facilitate the generation of turbulence, and manufacture to overcome the difficulty of manufacturing. The main goal is to improve the method. FIG. 6 shows a perspective view of an example of a high-density sword-shaped heat sink. In the figure, only 12 is different from FIG. 5, and 12 is a pin-shaped pin group formed with high density.

[0004]

The problems to be solved by the invention are the following three problems, and the present invention solves them. Although the Kenyama-shaped heat sink is being improved, the goal is to improve the heat transport performance first, so the problem is not improved at all, but rather worsened. That is, the pressure loss of forced convection parallel to the heat-receiving flat plate increases due to the smaller diameter and higher density of the pin, and it is necessary to make the cooling fan powerful in order to maintain the air volume and speed, which causes noise. Was a problem. As a countermeasure against this, a means of blowing forced convection perpendicular to the heat-receiving flat plate from above the sword-shaped heat sink is also adopted, but the flow direction of convection after collision with the heat-receiving flat plate is eventually parallel to the heat-receiving flat plate. Since the pressure loss in this case was large, it was necessary to make the cooling fan powerful, and the noise problem was not solved. These points were the first problems to be solved.

As a second problem, the promotion of the diameter reduction and the density increase of the pins make the production of the pin group difficult at an accelerating rate, making the production cost high and making it practically difficult. . In addition, it is difficult to give the pin the required height from the viewpoint of processing technology by making the pin diameter smaller and the density higher, and it is also difficult to maintain the necessary heat dissipation area, and to achieve the target cooling performance. There was also a fear of making it difficult to exert.

Furthermore, the third problem is the most important one, not only the sword-shaped heat sink but a problem common to all the conventional heat sinks, and it has been impossible to solve it at all in the past. It is a difficult problem. It occurs when the heating element is large or when a plurality of heating elements are arranged in series along the convection flow of the cooling fluid. The state is shown in (a) and (b) of FIG.

(A) shows a case where a conventional plate fin type heat sink is applied to the long heating element 3 to radiate heat. In this case, the plate fin group also becomes large, and the convection 4 undergoes heat exchange while passing through the long fin gap, and the temperature is greatly increased as the convection progresses. In the figure, 4-1 indicates low temperature convection introduced into the plate fin, and 4-2 indicates high temperature convection discharged from the plate fin. The convection gradually loses its heat exchanging ability as the temperature rises. Therefore, the heat dissipation efficiency of the plate fin decreases as it reaches the downstream side, and its significance is lost. That is, increasing the length of the plate fin type heat sink cannot be said to be an effective means for heat dissipation.

(B) shows a case where a plurality of heating elements are arranged in series along the convection flow of the cooling fluid, as shown in 3-1, 3-2, 3-3, and accordingly, those elements are arranged in series. The individually arranged heat sinks are also arranged in series along the flow. The figure shows an example in which Kenyama-shaped heat sinks are arranged in series, and the low temperature convection 4-1 is introduced into the upstream Kenyama-shaped pin group 12-1 and then sequentially to the downstream Kenyama-shaped pin group 12-2. And 12-3. The convections that have passed through the respective pin groups are heat-exchanged with each other and rise in temperature to become convections 4-2 and 4-3, which are introduced into the downstream side pin group and finally become high temperature convection 4-4. Is discharged. In this case as well, the temperature of convection 4-2 rises and the pin-shaped pin group 1
The heat radiation efficiency of 2-2 is remarkably reduced, and convection due to this effect 4-
Since the temperature of No. 3 is much higher than the temperature of the convection 4-2, the heat dissipation efficiency of the sword-shaped pin group 12-3 is much lower than that of the sword-shaped pin group 12-2. Therefore, the heat dissipation ability of the entire sword-shaped heat sink group is greatly reduced. That is, it can be said that the series arrangement of the heat sink groups in the same convection flow is an unfavorable means for heat dissipation.

[0009]

The second problem among the problems to be solved is a patent pending in Japanese Patent Application No. 3-264238 (wire heat sink) which has been previously proposed and put into practical use by the present inventor. And its manufacturing method) and Japanese Patent Application No. 4-135507 (Kakeyama type heat sink having a group of l-shaped pins) can solve the problem. Especially Japanese Patent Application No. 4-135
Application of No. 507 can sufficiently increase the height of the pin group. The effect of the means for solving the problems to be described later is increased by increasing the height of the pin group.

FIG. 1 is a perspective view showing the basic structure of means for solving the problems. Reference numeral 2 is a heat receiving flat plate, and 3 is a heating element, which is adhered to the heat receiving surface 2-1 of the heat receiving flat plate 2. 12
Is a sword mountain-shaped pin group which is upright on the heat radiating surface 2-2 of the heat receiving flat plate 2 and is densely adhered by brazing or welding to be integrated with each other to form a sword mountain shape. Reference numeral 1 denotes a convection control tube, which is arranged along the outer peripheral surface of the sword mountain-shaped pin group 12 except for a portion from the heat radiating surface 2-2 to a predetermined height. Up to the predetermined height, or up to a predetermined height exceeding the height of the sword-shaped pin group 12, the inner wall surface of the convection control pipe 1 is a sword-shaped pin. It is adhered to the pin group on the outer periphery of the group 12 or arranged in the vicinity thereof.

[0011]

The basic structure of the applied structure of the sword-shaped heat sink as shown in FIG. 1 is that the cooling convection 4 passing through the inside of the sword-shaped pin group 12 partially or wholly flows orthogonal to the pin group. There is an action to change from the to parallel flow to the pin group, and this change of flow brings various changes and improvements to the heat dissipation method of heat sink application. Various changes in the flow, various heat radiation methods of application thereof, and their effects will be described in detail by the following various embodiments.

[0012]

[First Embodiment] The Kenzan-type heat sink in the first embodiment has the same application structure as that illustrated in FIG. 1 and generates heat in convection parallel to the substrate surface on which the heating element 3 is mounted. It is arranged on the element 3. In the case of such an application structure, the flow of cooling convection passing through the inside of the pin-shaped pin group 12 is parallel to the substrate surface, that is, orthogonal to the pin group, and perpendicular to the substrate surface, that is, parallel to the pin group. It is divided into two streams. This action is due to the action of the low temperature convection flow 4-1 passing through the upper edge of the convection control tube 1 to reduce the atmospheric pressure at the upper edge portion of the convection control tube 1 and generate a suction force, which causes upward convection inside the pin group. It is exerted by generating it. This action has the effect of reducing the pressure loss of cooling convection inside the pin group 12 and improving the heat dissipation capability of the heat sink. Therefore, it is possible to alleviate the need to strengthen the fan to improve performance.

This effect is particularly great in Japanese Patent Application No. 4-135507 (Kakeyama type heat sink having a group of l-shaped pins). This is because in the l-shaped pin group, the convection parallel to the pin has a higher heat exchange efficiency and a smaller pressure loss than the convection perpendicular to the pin. Further, this effect is more excellent as the height of the pin group is higher. This is due to the length of the flow section parallel to the pin.

Second Embodiment FIG. 2 is an explanatory view showing a second embodiment, and is a side view with a part in section. The present embodiment is an example of an applied structure of a sword-shaped heat sink when the heating elements 3 are arranged in series along the flow of the cooling convection 4. In the figure, the cooling convection flow path is separated into upper and lower two layers by a separator flat plate 6 parallel to the heat receiving flat plate, the lower layer is a low temperature convection flow path 9 for which heat exchange has not been completed, and the upper layer is heat The flow path 8 for high temperature convection after the replacement is completed, the heat-receiving flat plate side of the sword-shaped heat sink is arranged in the flow path 9 for low temperature convection in the lower layer, and the convection control tubes 1-1, 1- The upper ends of 2, 1-3, and 1-4 penetrate through the separator plate 6 and are opened into the high-temperature convection channels 8 of the upper layer.

In the application structure of the sword mountain type heat sink configured as described above, the convection introduced into the sword mountain shaped pin groups 12-1, 12-2, 12-3 and 12-4 of all the heat sinks. Is all low-temperature convection 4-1 that has not completed heat exchange, and all high-temperature convection 4-2 after completion of heat exchange flows through the high-temperature convection channel 8 and is discharged, and then flows into the heat sink on the downstream side. There is no. Therefore, the high temperature convection discharged from the upstream heat sink flows into the downstream heat sink group, which is a big problem in the conventional heat sink group disposition structure. The point that the heat dissipation performance is significantly reduced will be completely solved. Because of this, the heat radiation performance of the second embodiment of the present invention illustrated in FIG. 2 is significantly improved as compared with the prior art. Further, in the case of this embodiment, all the cooling convection flowing in the heat sink group is parallel to the pins, so that there is an effect that the pressure loss becomes small. Furthermore, the heat dissipation performance can be further improved by applying the sword mountain type heat sink having the l-shaped pin group. Further, since the height of the l-shaped pin group can be freely increased, it is possible to further improve the heat radiation performance. These also reduce the need to strengthen the fan to improve heat dissipation performance and also have the effect of reducing noise.

Third Embodiment FIGS. 3 (a) and 3 (b) are side views of partial cross sections showing a third embodiment of the present invention. Since all of the figures are natural convection sword-shaped heat sinks, the height of the sword-shaped pin group 12 is formed sufficiently high, and (a) is an application example in which the sword-shaped pin group 12 is held vertically. (B) is an application example in which the sword mountain pin group 12 is held horizontally. In each of the examples, the convection control tube 1 is extended to a height at which the chimney effect is sufficiently exerted, and in both cases, the extended portion of the convection control tube 1 is held vertically. The convection control pipe 1 covers at least half of the height of the sword-shaped pin group 12 at the tip thereof, and this portion assists the generation of an upward airflow. In (a), a large distance is provided between the substrate 5 on which the heating element 3 is mounted and the housing wall 7 of the device, the convection control tube 1 is extended between them, and the upper end thereof is the housing wall. It penetrates 7 and is opened to the outside of the device. In (b), the distance between the board 5 and the housing wall 7 of the device is about the height of the sword-shaped pin group 12, and the convection control tube 1 is vertical after penetrating the housing wall 7. It is bent upwards and extended to a height where a sufficient chimney effect is exhibited. In the application structure of the Kenzan-shaped heat sink configured as described above, the low temperature convection 4-1 that is sucked in from the vicinity of the bottom of the Kenyama-shaped pin group 12 and flows in parallel to the pin group is the stack effect of the convection control tube 1 and Kenzan. It is accelerated by the chimney effect of the shape pin group 12 itself, passes through the extension of the conical shape pin group 12 and the convection control tube 1, and is discharged as high temperature convection 4-2 from the end of the extension part of the convection control tube 1. It According to the experiment, due to the acceleration of the cooling convection, the heat dissipation performance by natural convection of the Kenyama type heat sink is 20% to 30%.
% Improved.

Fourth Embodiment FIG. 4 is an explanatory view showing a fourth embodiment and is a side view of a partial cross section. The sword mountain type heat sink applied to this embodiment is either a natural convection type heat sink or a forced convection type heat sink in which the convection in the sword mountain type pin group is blown from the bottom of the pin group. , Fig. 4
In, a plurality of sword-shaped heat sinks are arranged. Reference numerals 2-1, 2-2, 2-3 are heat receiving flat plates of the heat sinks, 12-1, 12-2, 12-3 are sword-shaped pin groups, and each pin group has a convection control tube. 1-1, 1-2, and 1-3 are inserted. The tip of each convection control tube 1 penetrates through the housing wall 7 of the device in which the sword-shaped heat sink is arranged, and is opened to the outside of the device. These convection control tubes 1 are not particularly provided with means such as height extension for exerting a chimney effect.

In the case of the application structure of the sword mountain type heat sink configured as described above, there is no need to provide a high temperature convection flow path in the equipment casing even if it is a natural convection method, and therefore there is an advantage that the equipment housing can be downsized. An even greater advantage is that no matter how many sword-shaped heat sinks are installed, there is no mutual thermal interference between heat sinks due to high temperature convection after heat exchange is completed, and all heat sinks have their functions. 100
It is a point that can be exhibited. As in the conventional natural body flow method, when arranging the pin group horizontally,
It is unavoidable that the heat sinks are arranged in a vertical relationship among a large number of heat sinks, and the performance of the upper heat sink is significantly reduced due to the influence of high temperature convection discharged from the lower heat sink.

The application structure of such a sword mountain type heat sink is not necessarily limited to the natural convection method, and the same effect is exerted even in the case of the forced convection method. As the most effective forced convection method implementing means in the applied structure of the present embodiment, it is most appropriate to provide a convection suction means or a convection blowing means at an arbitrary portion of the housing to increase the internal pressure of the housing. In that case, as illustrated in FIG. 4, low-temperature convection 4-1 is generated, and flows in the pin-shaped pin group 12 parallel to the pin group at a flow velocity corresponding to the degree of increase in internal pressure, and the heat amount of the pin group is generated. While being absorbed, high-temperature convection 4-2 is generated and is discharged to the outside of the housing. The feature of this embodiment is that the heat dissipation capacity of the sword-shaped heat sink can be easily controlled by adjusting the degree of increase in the internal pressure of the housing. In addition, convection in the pin-shaped pin group 12 in this embodiment is parallel to the pin group, and the area of the inflow portion of the low temperature convection flow 4-1 is the outer peripheral area of the cylinder. There is little pressure loss when convection flows into, and it is not necessary to make the means for increasing the internal pressure of the housing particularly strong,
Therefore, there is no problem that noise is generated.

[0020]

As described in detail in each of the embodiments of the present invention, the effect of the present invention is that the convection control tube, which is an additional component having an extremely simple structure, is only attached, but the sword mountain shape is used. The convective flow in the heat sink is converted into a flow parallel to the pin group, the pressure loss is significantly reduced, not only improves the heat dissipation characteristics of the heat sink, but also reduces noise and enables miniaturization of equipment. It has many effects such as preventing mutual thermal interference between a plurality of heat sinks and improving their comprehensive heat dissipation characteristics, providing a new structure of a natural convection radiator, and so on.

[Brief description of drawings]

FIG. 1 is a perspective view showing a basic structure and a first embodiment of the present invention.

FIG. 2 is a side view of a partial cross section showing a second embodiment of the present invention.

FIG. 3 is a side view of a partial cross section showing a third embodiment of the present invention.

FIG. 4 is a side view of a partial cross section showing a fourth embodiment of the present invention.

FIG. 5 is a perspective view of a plate fin group heat sink.

FIG. 6 is a perspective view of a sword-shaped heat sink.

FIG. 7 is a view for explaining a conventional heat radiation state.

[Explanation of symbols]

 1 Convection control tube 2 Heat receiving flat plate 3 Heat generating element 4 Convection 5 Element mounting substrate 6 Separator flat plate 7 Housing wall 8 High temperature convection channel 9 Low temperature convection channel 11 Plate fin group 12 Kenzan shaped pin group

Claims (4)

[Claims] 1. An applied structure of a sword mountain-shaped heat sink in which a radiating pin group is formed in a sword shape on a radiating surface of a heat receiving flat plate having a heat receiving surface and a heat radiating surface, and an outer periphery of the sword mountain shaped pin group perpendicular to the heat radiating surface. Along the surface, except for the part from the heat dissipation surface to the predetermined height, from this predetermined height to the height of the sword mountain shaped pin group, or to exceed the height of the sword mountain shaped pin group. A thin-walled tubular convection control tube is inserted up to the height, and the inner wall surface of this convection control tube is adhered to or close to the outer peripheral pin group of the sword-shaped pin group. Applicable structure of sword mountain shape heat sink. 2. The cooling convection channel is divided into upper and lower two layers by a separator plate parallel to the heat receiving plate, the lower layer is a low temperature convection channel for which heat exchange has not been completed, and the upper layer is It is a high temperature convection flow path for heat exchange completion, the heat-receiving flat plate side of the sword-shaped heat sink is located in the low temperature convection flow path of the lower layer, and the upper end of the convection control tube penetrates the separator flat plate. 2. The applied structure of a sword-shaped heat sink according to claim 1, wherein the upper layer is opened in a high temperature convection flow path. 3. The sword mountain type heat sink according to claim 1, wherein the sword mountain type heat sink is a natural convection type heat sink, and a height of the convection control tube is high enough to generate a chimney effect. Applied structure of heat sink. 4. The convection control heat sink, which is either a natural convection type heat sink or a forced convection type heat sink in which convection is blown into the pin type pin group from the bottom of the pin group. 2. The applied structure for a sword mountain-shaped heat sink according to claim 1, wherein the tip of the pipe is opened to the outside of the device by penetrating a housing wall of the device in which the sword-shaped heat sink is disposed.