JP3095778U6 - heatsink - Google Patents

Abstract

An object of the present invention is to provide a heat sink capable of achieving an optimal heat conducting function.
A heat sink (80) includes a heat transfer element (92), a heat dissipation base (90) having a heat dissipation shell (94) covering the heat transfer element (92), and a plurality of heat dissipation fins (82) mounted perpendicular to the heat dissipation shell (94). The bottom surface of the heat transfer element 92 is in contact with the heating device and has a larger area than the top surface of the heat transfer element 92.
[Selection diagram] FIG.

Description

[0001]
[Technical field to which the invention belongs]
The present invention relates to a heat sink.
[0002]
[Prior art]
With the increase in the efficiency of electronic devices, heat dissipation devices or heat dissipation systems have become essential equipment. If the heat generated by the electronic device is not properly released to the environment, efficiency may deteriorate or the device may burn. Thus, heat dissipation devices are particularly important for microelectronic devices (eg, ICs).
[0003]
With the increasing density of elements and advances in packaging technology, ICs have smaller areas. At the same time, the heat stored per unit area is increasing. Therefore, highly efficient heat sinks always form an important research subject in the electronics industry.
[0004]
Generally speaking, the heat radiating device is mounted on the surface of the heat generating device and removes heat from the device. According to the shape of the heat radiating base, the heat radiating device can be classified into a planar shape and a cylindrical shape.
[0005]
Please refer to FIGS. FIG. 9 is a schematic view of a conventional heat dissipation device 10. FIG.
FIG. 10 is a plan view of the planar heat sink 20 shown in FIG. 9. FIG.
It is sectional drawing of the planar heat sink 20 regarding the line XI-XI of FIG.
[0006]
As shown in FIGS. 9 to 11, the heat dissipation device 10 has an axial fan 12 and a planar heat sink 20. The planar heat sink 20 has a heat transfer plate 24, a radiating shell 26, and a plurality of radiating fins 22. The heat transfer plate 24 is formed from copper or a copper alloy.
[0007]
The heat radiation shell 26 is formed of aluminum or an aluminum alloy and covers the heat transfer plate 24. The heat radiation fins 22 are formed of aluminum or an aluminum alloy, and are vertically attached to the heat radiation shell 26. Axial fan 12
Is fitted and fixed to the radiation fins 22 of the heat sink 20. The bottom surface of the heat transfer plate 24 is mounted on a heating device (for example, a CPU (not shown)).
[0008]
Heating devices emit a large amount of heat during operation. Since copper has extremely good heat conduction properties, the released heat quickly flows to the heat radiation shell 26 and the heat radiation fins 22 via the heat transfer plate 24. The axial fan 12 removes the heat on the radiating fins 22 by wind, thereby achieving a radiating action.
[0009]
However, the generated heat is generated inside the heat transfer plate 24 by a heat transfer field (heat).
flow field) (see FIG. 11). As a result, the heat conduction effect is deteriorated in the central region of the heat radiation base 24. Further, in a typical heating device, the position where the most heat is generated is the central region. Therefore, the central region of the heat transfer plate 24 of the planar heat sink 20 needs a good heat transfer element in order to improve the heat dissipation effect.
[0010]
Cylindrical heat sinks have been proposed in the prior art to improve heat dissipation in the central region of the heat transfer plate 24. See FIGS. FIG.
Shows a schematic diagram of another conventional heat dissipation device 30. FIG. 13 is a plan view of the cylindrical heat sink 40 shown in FIG. FIG. 14 is a sectional view taken along line XIV-XI in FIG.
5 is a sectional view of the cylindrical heat sink 40 with respect to V. FIG.
[0011]
As shown in FIGS. 12 to 14, the heat dissipation device 30 includes the axial fan 12 (the same one as described in FIG. 9) and the cylindrical heat sink 40. Cylindrical heat sink 4
Numeral 0 has a heat transfer cylinder 44, a heat radiation shell 46, and a plurality of heat radiation fins 42. The heat transfer cylinder 44 is formed from copper or a copper alloy.
[0012]
The heat radiating shell 46 is formed of aluminum or an aluminum alloy and covers the rim of the heat transfer cylinder 44. The radiation fins 42 are formed of aluminum or an aluminum alloy, and are vertically attached to the radiation shell 46. Similarly, the axial fan 12 is fitted and fixed to the radiation fins 42 of the cylindrical heat sink 40. Then, the other surface of the cylindrical heat sink 40 is attached to a heat generating device (for example, CPU).
[0013]
When the heat generating device is in direct contact with the surface 40 of the cylindrical heat sink 40, the heat released during operation of the heat generating device rapidly flows to the heat transfer cylinder 44, the heat radiation shell 46, and the heat radiation fins 42. Due to the cylindrical design, heat flows along the heat transfer cylinder 44, the heat radiating shell 46, and the heat radiating fins 42 in the axial direction toward the axial fan 12. The axial fan 12 then provides convection of the air and emits heat.
[0014]
[Problems to be solved by the invention]
From the above description, it can be seen that the cylindrical heat sink 40 really solves the poor heat dissipation effect of the central region in the planar heat sink 20. But,
As can be easily understood from the heat transfer field shown in FIG. 14, the region near the connection interface between the cylindrical heat sink 40 and the axial fan 12 does not have a good heat radiation effect.
[0015]
This is obviously a waste of available space in the heat dissipation device 30.
The use of such devices in small electronics is not very practical. Further, the heat transfer plate 24 of the planar heat sink 20 and the heat transfer cylinder 44 of the cylindrical heat sink 40 are connected to the heat dissipation shells 26 and 46 by soldering, bonding, or high-pressure mounting, respectively. .
[0016]
If the accuracy of the heat transfer plate 24, the heat transfer cylinder 44, and the heat radiating shells 26, 46 are not sufficiently good, air gaps can appear at the coupling interface.
Also, soldering often increases the thermal resistivity of the contact interface and affects the thermal conduction of the planar heat sink 20 and the cylindrical heat sink 40.
[0017]
The present invention has been made in order to solve the problems associated with the above-described conventional technology, and has as its object to provide a heat sink that can achieve an optimal heat conduction action.
[0018]
[Means for Solving the Problems]
The invention according to claim 1 for achieving the above object is as follows.
A heat-dissipation base having a heat-transfer plate and a heat-transfer block attached to the center of the heat-transfer plate;
A plurality of heat dissipating fins vertically attached to the heat transfer plate and the heat transfer block,
A heat sink, wherein an area of a bottom surface of the heat transfer block is larger than an area of an upper surface of the heat transfer block.
[0019]
The invention according to claim 6 for achieving the above object is as follows.
A heat dissipating base having a heat transfer element and a heat dissipating shell covering the heat transfer element;
A plurality of radiating fins that are vertically attached to the radiating shell,
The heat sink is characterized in that a bottom surface of the heat transfer element is in contact with a heating device and has a larger area than an upper surface of the heat transfer element.
[0020]
[Embodiment of the invention]
Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, this invention
A more complete understanding may be had from the detailed description given below by way of example only. And, this does not limit the present invention.
[0021]
FIG. 1 is a schematic view of the heat dissipation device according to the present invention. FIG. 2 is a plan view of the heat sink according to the first embodiment of the present invention. FIG. 3 is a sectional view taken along line III-III in FIG. The heat sink according to the present invention is attached to a heating device such as a microprocessor or a central processing unit (CPU). As shown in FIGS. 1 to 3, the heat radiating device 50 according to the present invention includes the axial fan 12 and the improved heat sink 60 according to the first embodiment. The heat sink 60 has a radiation base 70 having a three-dimensional curved surface and a plurality of radiation fins 62.
[0022]
The heat dissipation base 70 has a heat transfer plate 64 and a heat transfer block 66 installed at the center of the upper surface 61 of the heat transfer plate 64. The radiating fins 62 are mounted perpendicular to the upper surface 61 of the heat transfer plate 64 and the side surfaces 68 of the heat transfer block 66.
[0023]
Since a plurality of radiating fins 62 are provided along the side surface 68, each has a different surface area. The axial fan 12 can be fixed to the heat sink 60 using four fixing tools (for example, screws) on the radiation fins 62 located at the four corners.
[0024]
A feature that must be emphasized of the heat sink 60 according to the first embodiment is that the heat transfer plate 64 of the heat dissipation base 70 is located on the upper surface 61 of the heat transfer plate 64.
It is to be attached to a substantially cylindrical heat transfer block 66. That is, the area of the bottom surface of the heat transfer block 66 is larger than the area of the upper surface.
[0025]
The heat transfer block 66 and the heat transfer plate 64 are integrally formed by using aluminum, an aluminum alloy, copper, or a copper alloy having a high thermal conductivity to form a heat dissipation base 70 having a three-dimensional curved surface. are doing. The radiation fins 62 are fixed to the radiation base 70 by soldering, or
And are formed integrally with it.
[0026]
The shape of the heat transfer block 66 is set by the distribution of the heat transfer field inside the heat conductor and the thermal conductivity obtained in the experiment. The manufacture and formation of the disclosed heat transfer block 66 will now be described using a brief description and related figures.
[0027]
Please refer to FIGS. FIG. 4 shows the heat transfer block 6 according to the first embodiment of the present invention, in which the thermal resistance R of the heat dissipation base 70 is changed with respect to the sectional width D of the heat transfer plate 64.
6 as a function of the ratio d / D of the cross-sectional width d of the bottom surface. FIG. 5 shows the first embodiment of the present invention, in which the thermal resistivity R of the heat radiation base 70 is changed by the bottom surface 63 of the heat radiation base 70.
It is shown as a function of the ratio h / H of the vertical height h of the heat radiating base 70 to the vertical height H between the radiating fin 62 and the top portion of the heat radiating fin 62. FIG. 6 shows Embodiment 1 of the present invention.
In accordance with the above, the thermal resistivity R of the heat dissipation base 70 is
8 as a function of the angle α.
[0028]
The parameters affecting the design of the heat transfer block 66 include the cross-sectional width D of the heat transfer plate 64, the cross-sectional width d of the bottom surface of the heat transfer block 66, and the vertical height h of the heat dissipation base 70 (the heat transfer plate 64 and the heat transfer block 66, the vertical height H from the bottom surface 63 of the heat dissipation base 70 to the top of the heat dissipation fins 62 (total height of the heat transfer plate 64, the heat transfer block 66, and the heat dissipation fins 62), and the heat transfer block. 66, the angle α between the bottom surface 67 and the side surface 68, and the thermal resistivity R of the heat dissipation base 70.
[0029]
As shown in FIGS. 4 to 6, the heat transfer block 66 of the first embodiment has the following features.
[0030]
(1) The cross-sectional width d of the bottom surface is smaller than the cross-sectional width D of the heat transfer plate 64. Ratio d /
When D approaches 0.5, at point A shown in FIG.
Reaches a minimum thermal resistivity.
[0031]
(2) The vertical height h of the heat radiation base 70 is smaller than or equal to the vertical height H from the bottom surface 63 of the heat radiation base 70 to the top of the heat radiation fins 62. That is,
The height of the heat transfer block 66 is not larger than the height of each radiating fin 62. Ratio h /
When H is in the range of 0.9 to 1.0, the heat dissipation base 70 has the minimum thermal resistivity at the point B shown in FIG.
[0032]
(3) The angle α between the bottom surface 67 and the side surface 68 of the heat transfer block 66 is smaller than 90 degrees. In other words, the area of the bottom surface 67 is larger than the area of the upper surface 65. When the angle α is in the range of 80 to 85 degrees, the heat radiation base 70 moves to the point C shown in FIG.
At a minimum thermal resistivity is reached.
[0033]
When the bottom surface 67 of the heat transfer plate 64 according to the first embodiment is attached to a heat generating device (not shown), the heat generated by the device passes through the disclosed heat transfer block 66 to each of the radiation fins 62. Can be moved to And the axial fan 12
Provides convection of air and removes heat.
[0034]
FIG. 7 is a cross-sectional view of the heat sink 80 according to Embodiment 2 of the present invention. The largest difference between the heat sink 80 and the heat sink 60 according to the first embodiment is that the heat sink 80 has a heat dissipation base 90 having a heat transfer element 92 and a heat dissipation shell 94 for covering the heat transfer element 92. It is.
[0035]
The heat dissipation shell 94 and the heat dissipation base 90 are formed from different metal materials. For example, the heat transfer element 92 is formed from copper, and the heat dissipation shell 94 is formed from aluminum. The plurality of radiation fins 82 are formed integrally with the radiation shell 94. Note that the radiation fins 82 are formed only on the upper surface 81 and the side surface 88 of the radiation shell 94.
[0036]
On the other hand, the heat transfer element 92 is similar to the heat dissipation base 70, and has a heat transfer plate 84 and a heat transfer block 86 formed thereon. It should be noted that the size, shape, configuration, and characteristics of the heat transfer plate 84 and the heat transfer block 86 in the second embodiment are similar to those in the first embodiment. The only difference is that the three-dimensional curved surface of the heat transfer element 92 is covered by a thin part of the heat dissipation shell 94 by soldering or high-pressure fixing.
[0037]
The bottom surface 83 of the heat transfer element 92 (ie, the bottom surface 83 of the heat transfer plate 84) is also in direct contact with the heating device. In the second embodiment, the heat transfer block 8
The only difference between the parameters of designing the sixth embodiment and the first embodiment is that the cross-sectional width d is the width of the bottom surface 87 of the heat transfer block 86 to which the width of the heat radiation shells 94 on both sides is added.
[0038]
Therefore, the shape of the heat transfer block 86 is specifically designed according to the heat transfer field inside the heat conductor and the thermal conductivity obtained from experiments. The experimental results according to the second embodiment are similar to those in FIGS. 4 to 6 and the heat radiation action is the same as that in the first embodiment, and therefore, description thereof will not be repeated.
[0039]
As described above, the heat sink 80 is for a cooler, and the heat transfer element 92,
A heat dissipation shell 94 covering the heat transfer element 92 and a plurality of heat dissipation fins 82 mounted on the heat dissipation shell 94 are provided. The heat transfer element 92 has a heat transfer plate 84 and a heat transfer block 86 attached to a central portion. The area of the bottom surface of the heat transfer block 86 is larger than the area of the upper surface. When the bottom surface of the heat transfer plate 84 contacts a device that requires heat dissipation, the heat transfer block 86 increases the amount of heat conduction at the center of the heat transfer plate 84 to optimize the heat generated by the heat generating device. Can be released at a rate of
[0040]
FIG. 8 is a sectional view of the heat sink 100 according to Embodiment 3 of the present invention. The configuration and structure of the heat sink 100 are the same as those of the heat sink 80 according to the second embodiment. The only difference is that the heat sink 100 has a connector or screw (connecting element) 102 for connecting the heat dissipation shell 94 and the heat transfer block 86. The heat radiation shell 94 has a through hole 104, and the heat transfer block 86 has a groove 106 formed therein. The groove 106 corresponds to the through hole 104 and has the same diameter.
[0041]
Another feature according to the third embodiment is that when the heat transfer element 92 and the heat radiating shell 94 are connected to each other, the screw 102 having a diameter slightly larger than the diameter of the through hole 104 and the groove 106 is formed in the through hole of the heat radiating shell 94. 104. The screw 102 is rotated by hand or machine and inserted into the groove 106 of the heat transfer block 86. Then, the heat radiating shell 94 is closely connected to the heat transfer element 92 by the screw 102. Therefore, when two different metals are connected by soldering, the thermal resistivity clearly increases, but in this case, an increase in the thermal resistivity can be avoided.
[0042]
It must be emphasized here that the sides of the heat transfer block need not be planar. For example, a smooth curved surface is possible. Further, the heat radiation fins can be formed in other shapes having a larger heat radiation area. These variations are within the scope of the invention, but will not be described in further detail here.
[0043]
As described above, a different feature of the present invention as compared with the prior art is that all the heat sinks 60, 80, 100 in the embodiment of the present invention have the heat radiation bases 70, 90 having a three-dimensional curved surface. These are designed with heat transfer fields inside the heat conductor and thermal conductivity data obtained from experiments. Therefore, the problem of heat radiation of the conventional planar and cylindrical heat sinks is solved. The heat dissipation effect of the heat sink can be further improved by the connecting element introduced in the third embodiment.
[0044]
[Effect of the invention]
As described above, by providing the heat dissipation base having a three-dimensional curved surface,
It is possible to provide a heat sink that can achieve an optimal heat conduction action. In particular, when a connecting element is used to tightly couple the heat-dissipating base and the heat-dissipating shell, a better heat conduction effect can be achieved.
[Brief description of the drawings]
FIG. 1 is a schematic view of a heat dissipation device according to the present invention.
FIG. 2 is a plan view of the heat sink according to the first embodiment of the present invention.
FIG. 3 is a sectional view taken along line III-III of FIG. 2;
FIG. 4 shows the thermal resistivity of the heat dissipation base as a function of the ratio of the sectional width of the bottom surface of the heat transfer block to the sectional width of the heat transfer plate according to the first embodiment of the present invention.
FIG. 5 is a function of the ratio of the vertical height of the heat radiation base to the vertical height between the bottom surface of the heat radiation base and the top of the heat radiation fin according to the first embodiment of the present invention; As shown.
FIG. 6 shows the thermal resistivity of the heat dissipation base as a function of the angle between the bottom surface and the side surface of the heat transfer block according to the first embodiment of the present invention.
FIG. 7 is a sectional view of a heat sink according to a second embodiment of the present invention.
FIG. 8 is a sectional view of a heat sink according to a third embodiment of the present invention.
FIG. 9 is a schematic view of a conventional heat dissipation device.
FIG. 10 is a plan view of the planar heat sink shown in FIG. 9;
11 is a cross-sectional view of the planar heat sink taken along the line XI-XI in FIG.
FIG. 12 is a schematic view of another conventional heat dissipation device.
FIG. 13 is a plan view of the cylindrical heat sink shown in FIG.
14 is a sectional view of the cylindrical heat sink taken along the line XIV-XIV in FIG.
[Explanation of symbols]
10, 30, 50 ... heat dissipation device,
12 ... axial fan
20, 40, 60, 100 ... heat sink,
22, 42, 62, 82 ... radiation fins,
24, 64, 84: heat transfer plate,
26, 46, 94: heat radiation shell,
44 heat transfer cylinder,
61, 81 ... upper surface,
63, 83 ... bottom,
65 ... upper surface,
66 ... heat transfer block
67, 87 ... bottom,
68,88 ... side,
70, 90 ... heat dissipation base,
92 heat transfer element,
102 ... screws,
104 ... through-hole,
106 ... groove,
d ... sectional width,
D: cross-section width,
h ... vertical height,
H ... vertical height,
R: thermal resistivity,
α ... angle.

Claims (11)

A heat-dissipation base having a heat-transfer plate and a heat-transfer block attached to the center of the heat-transfer plate;
A plurality of heat dissipating fins vertically attached to the heat transfer plate and the heat transfer block,
The heat sink according to claim 1, wherein an area of a bottom surface of the heat transfer block is larger than an area of an upper surface of the heat transfer block. The heat sink according to claim 1, wherein the plurality of radiating fins have different surface areas and are attached to side surfaces of the heat transfer block. The heat sink according to claim 1, wherein a height of the heat transfer block is not greater than a height of a radiating fin on the radiating base. The heat sink according to claim 1, wherein a side surface of the heat transfer block is a smooth curved surface. The heat sink according to claim 1, wherein an axial fan is attached to the radiation fin. A heat dissipating base having a heat transfer element and a heat dissipating shell covering the heat transfer element;
A plurality of radiating fins that are vertically attached to the radiating shell,
A heat sink, wherein a bottom surface of the heat transfer element is in contact with a heat generating device and has an area larger than an upper surface of the heat transfer element. The heat transfer element includes:
A heat transfer plate having a bottom surface in contact with the heating device;
A heat transfer block attached to a central portion of the heat transfer plate,
The top and side surfaces of the heat transfer block are in direct contact with the heat dissipation shell,
The area of the upper surface and the side surface of the heat transfer plate is larger than the area of the upper surface and the side surface of the heat transfer block, and the area of the upper surface of the heat transfer block is smaller than the area of the bottom surface of the heat transfer block. The heat sink according to claim 6, wherein The heat sink according to claim 7, wherein a plurality of radiating fins attached to the radiating shell other than the heat transfer block have different surface areas. The heat sink according to claim 7, wherein a height of the heat transfer block is not greater than a height of the heat radiating fin on the heat radiating shell. The heat sink according to claim 7, wherein a surface of the heat radiation shell attached to a side surface of the heat transfer block has a smooth curved surface. Furthermore, it has a connecting element,
The heat dissipation shell has a through hole,
In the heat transfer block, a groove corresponding to the through hole is formed,
The diameter of the connection element is slightly larger than the diameter of the groove, and the connection element is inserted into the through hole and fixed inside the groove,
The heat sink according to claim 7, wherein the heat radiating shell is closely connected to the heat transfer block.

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