TWI424140B - Flattened heat dissipation structure with fins parallel to heat receiving surface - Google Patents

Description

Heated surface parallel fin type flat heat dissipation structure

The present invention relates to a heat sink that is used for cooling a member that is housed in an electronic device casing and that generates an IC (integrated circuit) that generates heat during operation, a CPU (central processing unit), or the like; or Other electronic parts with a heat generating part.

In an electronic device, in the electronic component housed in the casing of the electronic device, the CPU (Central Processing Unit) is the electron that generates the largest amount of heat during operation, especially in response to the high clock frequency of the operating clock in recent years. One of the parts. Also, from the viewpoint of ensuring the operational stability and operational life of the CPU, heat dissipation measures are an important problem. For example, in order to dissipate heat from the CPU, a water-cooled water-cooling module or an air-cooled heat sink structure (heat sink) having a heat sink is used.

The water-cooled heat sink structure adopts the following technique: a pump is used to transport the heat-absorbing liquid to a radiator to dissipate heat, but it is disadvantageous because a pump is used or a liquid flows out of the pipe. Long-term reliability or cost. On the other hand, the heat sink is easy to maintain, has high reliability, and low cost, so it is still widely used.

Japanese Laid-Open Patent Publication No. 2001-196511 discloses a heat sink including a tower fin or a plurality of pin fins for cooling a semiconductor such as an IC or a CPU or an electronic component having a heat generating portion. A heat sink having a generally thick thickness called a tower type has a structure in which a pillar is disposed to extend in a vertical direction from a heat receiving surface, and a plate-shaped fin that is parallel to the heat receiving surface is disposed.

As the heat generation of the CPU increases, a heat sink with better heat dissipation is required. On the other hand, the high density of the electronic device is also progressing, and the space that the heat sink can be used is gradually limited in the frame of the electronic device. Therefore, the necessity of a heat sink that is compact and has a good heat dissipation efficiency is more and more improved.

However, in the case where a plurality of printed circuit boards are arranged at a narrow interval, the space on the upper side of the CPU (the surface side opposite to the joint surface on which the printed circuit board on which the CPU is mounted) is small, and it is impossible to use a general heat dissipation having a large thickness. Chip type heat sink When the heat sink surface is the main surface of the base surface on which the heat receiving surface is a main surface, and the heat sink having the plate fins is vertically erected with respect to the heat receiving surface, it is difficult to ensure sufficient heat dissipation performance.

Fig. 18 is a view showing an example of a heat sink type heat sink. The heat sink 20 is configured by arranging a plurality of plate fins 3 in a direction perpendicular to the heat receiving surface from the bottom plate 19 (hereinafter, this heat sink is referred to as a "vertical fin type heat sink"). In the vertical fin type heat sink 20, when the thickness of the bottom plate 19 is made thin, the thermal resistance from the heat receiving region to the separated plate fins 3 is increased. Therefore, even if the number of the plate fins 3 is increased, the increase in the number of sheets cannot be effectively utilized for heat dissipation. On the other hand, when the bottom plate 19 is made thicker, the height of the plate-like heat sink 3 which is originally low in height becomes lower as the height is restricted, and the heat radiating area of the plate-shaped heat sink 3 is reduced. That is, even if there is a space in a direction parallel to the main surface of the printed circuit board, the space cannot be used to improve the heat dissipation performance of the heat sink, which is a problem.

Even if there is no space on the upper side of the CPU, if there is a space somewhere in the casing of the electronic device, a heat sink (hereinafter referred to as a separate heat sink) 23 as shown in FIG. 19 can be used, and the heat sink is connected by a heat pipe. Heated block and plate fin. The heat dissipating tube 22 connects the heat receiving block 21 and the split heat sink 23 of the vertical heat sink type heat sink 20, and only the heat receiving block 21 is disposed in the CPU (not shown), and the vertical heat sink is disposed in another space in the electronic device housing. Type radiator 20. The heat of the CPU received by the heated block 21 is transmitted to the vertical heat sink type heat sink 20 via the heat dissipation pipe 22, and is radiated from the vertical heat sink type heat sink 20.

However, in the entire electronic device casing, the arrangement of various electronic components is continuously increased, and it is difficult to secure a space for accommodating the heat sink. Moreover, if the heat pipe 22 is used, a complicated mounting mechanism is required to fix the heat receiving block 21 and the vertical heat sink type heat sink 20 at the separated positions on one side, and the heat receiving block 21 is closely attached to the CPU, resulting in assembly. The increase in working hours and the increase in the cost of electronic equipment are problems.

Therefore, in order to solve the above problems of the prior art, an object of the present invention is to provide a heat dissipating fin-type flat heat dissipating structure, which can be used for improving the heat sink in a space parallel to the main surface of the printed circuit board. Thermal performance.

In order to achieve the above object, a heat-radiating parallel fin type flat heat dissipating structure according to the present invention is constituted by a columnar portion extending in a long axis direction and having at least three sides parallel to a long axis, and the like One of the side surfaces is a heat receiving surface; and a plurality of plate-shaped fins extend from the two sides other than the side surface of the columnar portion that is the heating surface, along the first direction parallel to the heating surface and opposite thereto It extends in the second direction. Further, the height H (unit: mm) of the heat-radiating surface parallel heat sink type heat dissipation structure is a distance from the heat receiving surface to the plate-shaped heat sink farthest from the heat receiving surface, and the width W (unit: Mm) is a distance from the front end of the plate-shaped fin extending in the first direction from the columnar portion to the front end of the plate-shaped fin extending in the second direction from the columnar portion, and the H and W The relationship is expressed by the following formula:

H≦(W-47) ^0.5 /0.6+5

In the formula, H is 5 mm or more and W is 47 mm or more.

The plate-like fin has a plate thickness in the range of 0.8 mm to 1.5 mm, and the distance between the configurations, that is, the distance between the center of one plate-like fin 3 and the center of the other plate-like fin 3 adjacent thereto can be Range from 4mm to 5.5mm.

The material of the heat-radiating surface parallel fin-type flat heat dissipation structure is aluminum or an aluminum alloy having a heat transfer coefficient of 180 W/(m·K) or more, and the columnar portion extending in the longitudinal direction can be separated from the columnar portion. The width of the nearest portion of the heated surface, that is, the width of the heated surface is set to 10 mm to 12 mm, and the width of the portion farthest from the heated surface is set to 8 mm to 10 mm.

The material of the heat-receiving surface parallel fin-type flat heat dissipation structure is copper or a copper alloy having a heat transfer coefficient of 350 W/(m·K) or more, and the columnar portion extending in the longitudinal direction can be separated from the columnar portion. The width of the nearest part of the heated surface, that is, the width of the heated surface is set to 8 mm to 10 mm, and the width of the portion farthest from the heated surface is set to 2 mm to 5 mm.

The heat-receiving surface parallel fin type flat heat dissipating structure can be formed by extrusion molding or drawing.

According to the present invention, it is possible to provide a heat-radiating parallel fin type flat heat-dissipating structure, which can utilize a space parallel to the main surface in an electronic device frame in which the height direction of the main surface of the printed circuit board is restricted. The heat dissipation performance of the heat sink.

(Best form of implementing the invention)

According to the heating surface parallel fin type flat heat dissipating structure of the present invention, as shown in FIGS. 1 to 3, 6 to 8, and 11 to 17, a low height is formed and a vertical direction is perpendicular to the height direction thereof. The extended shape has the ability to surpass the heat dissipation performance of the vertical heat sink type heat sink 20 (refer to FIG. 18) of the prior art, and the vertical heat sink type heat sink 20 is disposed from the bottom plate in a direction perpendicular to the heat receiving surface. There are a plurality of plate fins.

First, a first embodiment of a heat-radiating parallel foam type flat heat dissipation structure according to the present invention will be described with reference to Figs. 1, 2, 3A and 3B.

As shown in FIG. 1, the heat receiving surface parallel fin type flat heat dissipation structure 1 is composed of a columnar portion 2 and a plurality of plate fins 3. The columnar portion 2 and the plate fins 3 are made of a metal material of the same nature. The columnar portion 2 is formed in a shape having four side faces (the side faces 2a, 2b, 2c, 2d as shown in Fig. 3B), and is surrounded by one of the side faces, that is, the dotted line 31-dashed line 31 and the edge of the columnar portion 2. The side surface (the side surface 2a shown in Fig. 3B) is the heat receiving surface 4. A dashed line indicated by reference numeral 30 indicates the long axis direction of the columnar portion 2. The symbol W, the symbol H, and the symbol L respectively indicate the width, height, and depth of the heat radiating surface parallel fin type flat heat dissipating structure 1. The depth L is set in accordance with the area of the cooling area or the space in which the heat dissipation structure is allowed to be provided. Further, the values of the width W and the height H are defined by using Equation 1 which will be described in detail later with reference to FIG.

The plate fins 3 are thin plate members. Further, the plate-like fins 3 are parallel to the heat receiving surface 4 from the side faces 2b and 2d of the columnar portion 2, that is, the side faces 2b and 2d other than the side faces 2a of the heat receiving surface 4, and are along the first direction. And extending in the second direction opposite to the first direction. The plate-shaped fins 3 extend from one end in the longitudinal direction of the columnar portion 2 to the other end, and extend from the respective side faces 2b and 2d of the columnar portion 2 in the first direction and the second direction, respectively.

In FIGS. 3A and 3B, reference numeral 5 denotes the width of the portion of the columnar portion 2 closest to the heat receiving surface 4 (that is, the width of the heat receiving surface 4 of the columnar portion 2), and corresponds to the broken line 31 and the broken line 31 of FIG. interval. Reference numeral 6 denotes the width of the portion of the columnar portion 2 which is the farthest from the heat receiving surface 4 (i.e., the width of the surface opposite to the heat receiving surface 4), and corresponds to the interval between the broken line 33 and the broken line 33 of Fig. 2 . The number of the side faces of the columnar portion 2 may not be limited to four sides 2a, 2b, 2c, 2d as shown in FIG. 3B, but may be set to three sides (that is, there may be no side faces 2c, which may be sideways). The cross section formed by 2a, 2b, and 2d is a triangular shape).

Since the heat receiving surface parallel fin type flat heat dissipating structure 1 has the above configuration, it can be processed by extrusion molding. The heat transfer surface parallel heat sink type flat heat dissipation structure 1 is formed of a heat conductive material in a high temperature state by a molding die (not shown). By the molding method, the columnar portion 2 and the plate-like fins 3 can be simultaneously formed.

Next, the heat radiating surface parallel fin type flat heat dissipating structure 1 of the present invention has the ability to surpass the heat dissipating performance of the vertical fin type heat sink 20 (refer to FIG. 18) of the prior art, which is shown in FIG. The heat sink 20 is provided with a plurality of plate fins disposed in a direction perpendicular to the heat receiving surface from the bottom plate.

In the graph of Fig. 4, the horizontal axis represents the width W (mm) of the heat dissipation structure, and the vertical axis represents the height H (mm) of the heat dissipation structure. Here, the heat dissipation structure system refers to a conventional heat sink type heat sink 20 in which a plurality of plate-shaped heat sinks are disposed in a direction perpendicular to the heat receiving surface from the bottom plate, and a heat sink structure system according to the present invention. The heated surface parallel fin type flat heat dissipation structure 1 of the invention. Further, in the case of the vertical fin type heat sink 20, the height H indicates the length from the heat receiving surface of the bottom plate 19 to the front end of the plate fins 3, and if the heat receiving surface is parallel to the fin type flat heat dissipating structure 1, the height H indicates heat generation. The distance from the face 4 to the plate-like fins 3 furthest from the heated face 4. In the case of the heat-receiving parallel fin type heat dissipating structure, the width W represents a distance from the front end of the plate-shaped fin extending in the first direction from the columnar body to the front end of the plate fin extending in the second direction. .

In FIG. 4, the symbol R indicates the ratio of the temperature rise of the heating element such as the CPU that is in contact with the heat receiving surface 4 divided by the amount of heat generated. More specifically, FIG. 4 illustrates a ratio R (=Tr-parallel) of the thermal resistance Tr-parallel of the heat radiating surface parallel fin type flat heat dissipating structure 1 to the thermal resistance Tr-vertical of the vertical fin type heat sink 20. /Tr-vertical) In the range of 0.9 or less, the vertical fin type heat sink 20 is provided with a plurality of the same width and the same height from the bottom plate 19 in a direction perpendicular to the heat receiving surface as shown in FIG. Plate fins 3. The ratio R of the thermal resistance is 0.9 or less, which means that a vertical fin type heat sink in which a plurality of plate fins are arranged in a direction perpendicular to the heat receiving surface from the bottom plate is heated in parallel with the heat receiving surface, compared to the prior art. The sheet-type flat heat dissipation structure 1 has a small thermal resistance and can efficiently dissipate heat.

Fig. 4 shows a heat dissipating fin type flat heat dissipating structure 1 and a general vertical fin type heat sink 20 shown in Fig. 18, for changing the thickness of the fin or the distance between the fins, etc., using a hot fluid The results obtained by comparing the performances of the shape-optimized persons are analyzed; and after the optimized heating-surface parallel fin-type flat heat-dissipation structure 1 and the optimized vertical fin-type heat sink 20 are tested, The test results are roughly consistent with the analysis results. When the heat dissipating structures having the same width W and the same height H are compared with each other, the heat radiating surface parallel fin type flat heat dissipating structure 1 is compared with the following formula 1 as compared with the general vertical fin type heat sink 20 (see FIG. 18). When the relationship is established, it can be found that the heat dissipation efficiency is higher by more than 10%.

H≦(W-47) ^0.5 /0.6+5...(1)

Among them, the length of W and H is in millimeters, and 47≦W, 5≦H.

In addition, in FIG. 4, the material of the heat radiating surface parallel fin type flat heat radiating structure 1 is a metal having a conductivity coefficient of 180 W/(m.K) or more, and the flow rate of air is generally applicable to extrusion molding or In the range of the heat dissipation structure formed by the drawing, the relationship of the above formula 1 is hardly dependent on the material or flow velocity of the heat dissipation structure. In addition, FIG. 4 shows that the width W of the heat-radiating surface parallel fin-type flat heat dissipation structure 1 generally used is 100 mm or less, but the upper limit of the width W or the height H is not particularly limited as long as the relationship of the above formula 1 is satisfied. limited.

By using the heat-receiving surface parallel fin-type flat heat dissipation structure having the size range defined by the above formula 1, the vertical heat sink can be provided in a place where the space on the top surface side of the heat generating body such as the CPU is small. The heat-receiving surface parallel heat sink type flat heat dissipation structure 1 which is not realized by the heat sink 20 and has high heat dissipation performance. Thereby, it is possible to prevent an increase in the size of the electronic device, and to suppress an increase in the temperature of the heating element such as the CPU, and to greatly improve the reliability or the life of the electronic device.

Further, in the arrangement of the heat-receiving surface parallel fin-type flat heat dissipation structure 1, when the forced air cooling by the blower fan is used, it is preferable to make the long-axis direction 30 of the columnar portion 2 and the flow line of the air generated by the fan. The directions are substantially the same, but when the forced air cooling is not particularly performed, it is preferable that the longitudinal direction 30 of the columnar portion 2 substantially coincides with the vertical direction. By disposing the heat-receiving surface parallel fin-type flat heat dissipation structure 1 in this manner, the original heat dissipation performance can be exhibited.

When the plate fins 3 are thin, the thermal resistance from the front end of the fins to the columnar portion 2 becomes high, and the amount of heat dissipated from the vicinity of the front end of the plate fins 3 is lowered; When it is thick, the gap between the adjacent plate-like fins 3 is narrowed, and the flow of air is hindered, and the amount of heat radiation is lowered.

Although the plate thickness of the plate fins 3 is optimal, if it is considered to be generally used, the heat receiving surface parallel heat sink type flat heat dissipating structure 1 having a width W of 100 mm or less is as shown in FIG. The distance from the columnar portion 2 to the front end of the plate-like fins 3 is relatively long, but it can be found that the plate-like fins 3 have the highest heat dissipation performance in the range of 0.8 mm to 1.5 mm.

The thickness of the plate-like fins 3 described above can be molded by a extrusion molding method or a drawing method. Further, when the pitch of the plate fins 3 (the distance between the center of one plate fin 3 and the center of the other plate fin 3 adjacent thereto) is large, the heat radiating surface is parallel to the fin type flat heat dissipation. The height H of the structure 1 is limited, so that the number of sheets of the plate-like fins 3 arranged is reduced, and the surface area contributing to heat dissipation is reduced. On the other hand, when the pitch of the plate-like fins 3 is small and the thickness of the plate-like fins 3 is thick, the interval between the adjacent fin-shaped fins 3 is narrowed, and the flow of air is hindered, and the heat dissipation performance is lowered. Therefore, the pitch of the plate fins 3 also has an optimum value.

When the height of the heat dissipating structure in which the heat radiating surface parallel fin type flat heat dissipating structure 1 exhibits superior heat dissipation performance is 17 mm or less, the distance between the plate fins 3 of the heat dissipating structure is as shown in FIG. It is found that the heat dissipation performance is the highest when the pitch of the plate-like fins 3 of the conventional vertical fin type heat sink 20 (refer to FIG. 18) is the optimum value, that is, about 4 mm to 5.5 mm.

By making the plate fins 3 the above-mentioned plate thickness and pitch, the heat receiving surface parallel fin type flat heat dissipating structure 1 exhibits optimum heat dissipation characteristics.

Fig. 5 is a contour line showing the relative thermal resistance of the plate-like fins 3 of the heat-dissipating fin-type flat heat-dissipating structure 1 and the variation of the pitch of the heat-dissipating fin-type flat heat-dissipating structure 1 by the analysis. The optimum range of thickness and spacing of the plate fins 3 is shown. In Fig. 5, the symbol Tr represents the thermal resistance, and the symbol Tr (min) represents the value of the smallest thermal resistance (thermal resistance minimum value). As described above, the plate thickness and the pitch of the plate fins 3 have an optimum value, and as the deviation from the optimum value, the thermal resistance increases. That is, as the temperature deviates from the optimum value, the heat dissipation performance of the heat-radiating surface parallel fin-type flat heat dissipation structure 1 is lowered.

As shown by the dotted line in FIG. 5, the plate-shaped fin 3 has a plate thickness of 0.8 mm to 1.5 mm and a pitch of 4 mm to 5.5 mm, which is included in the minimum value Tr(min) of the thermal resistance Tr at the thermal resistance. In a region within 3% (Tr ≦ Tr (min) × 1.03), most of the regions overlap with a region (Tr Tr (min) × 1.01) in which the thermal resistance Tr is within 1% of the minimum value. As can be seen from Fig. 5, when the plate-like fins 3 have a thickness of 0.8 mm to 1.5 mm and a pitch of 4 to 5.5 mm, the heat-dissipating structure substantially exhibits an optimum heat-dissipating performance.

Specifically, for example, the following structure can be said to be an optimum structure: the heat-receiving surface parallel fin-type flat heat dissipation structure 1 (first embodiment) shown in FIG. 3A, and having a height of 10 mm (H=10), respectively Three plate-shaped fins 3 are disposed on each of the two side faces 2b and 2d of the columnar portion 2, and the heat-receiving face-parallel fin-shaped flat heat dissipating structure 1 (second embodiment) shown in Fig. 6 has a height of 5.5 mm. (H=5.5), two plate-shaped fins 3, that is, plate-shaped fins 3 having a thickness of 1 mm and a pitch of 4.5 mm, are disposed on both side faces of the columnar portion 2; and the heat-receiving faces shown in FIG. In the fin-type flat heat dissipation structure 1 (third embodiment), the height is 14.5 mm, and four plate fins 3 and the like are disposed on each of both side faces of the columnar portion 2, respectively. The heat-receiving surface parallel fin-type flat heat dissipation structure 1 has the highest heat dissipation characteristics in the heat dissipation structure having the same width and the same height.

According to the first embodiment (FIG. 1), the second embodiment (FIG. 6), and the third embodiment (FIG. 7) of the heat-radiating parallel fin type flat heat dissipation structure 1 of the present invention, the heat receiving surface 4 and the heating surface 4 are One of the main faces of the plate-like fins 3 closest to the heat receiving surface 4 forms the same plane in which there is no step difference therebetween. However, when the thickness of the heat generating body such as the CPU is thin, and the air flow to the main surface of one of the plate fins 3 is not good, as shown in FIG. 8 (fourth embodiment), the heat receiving surface 4 may be used. A step is provided between a main surface of the plate-like fin 3 closest to the heat receiving surface 4. In the fourth embodiment of the heat-receiving surface parallel fin-type flat heat dissipation structure 1 shown in FIG. 8, the heat receiving surface 4 has a shape in which a stent is protruded from the plate-shaped fins 3.

Next, the width of the columnar portion 2 will be described. When the width of the columnar portion 2 (the length of the columnar portion in the direction parallel to the heat receiving surface 4 in the cross section of the heat dissipating structure perpendicular to the major axis of the columnar portion 2) is increased, the heating surface 4 and the distance are increased. The thermal resistance between the plate fins 3 farthest from the heat receiving surface 4 is lowered, and the heat dissipation from the plate fins 3 farthest from the heat receiving surface 4 is easily increased, which is a front effect; but when the heated surface is parallelized When the width W (refer to FIG. 3A) of the entire flat heat dissipation structure is limited, the distance from the columnar portion 2 to the front end of the plate fins 3 is accordingly shortened, and the surface area of the plate fins 3 is reduced. For its negative effects.

Therefore, the width of the columnar portion 2 also has an optimum value. The optimum value of the width of the columnar portion 2 differs depending on the heat transfer coefficient of the material, and the higher the heat transfer coefficient, the smaller the optimum value is. Further, the width of the portion closer to the heating surface 4 is larger than the width of the portion farther from the heating surface 4, and the heat dissipation performance is increased, which is confirmed.

Here, the width of the columnar portion 2 will be described with reference to FIGS. 9 and 10 .

The width 5 of the portion of the columnar portion 2 closest to the heat receiving surface 4 (see FIG. 3A), that is, the width of the heat receiving surface 4, and the width of the portion of the columnar portion 2 that is the farthest from the heat receiving surface 4 (refer to the figure) 3A) The results of obtaining the optimum values are respectively known, and the following matters are known.

In the case of an aluminum expansion material which is often used as a heat dissipation part having a heat transfer coefficient of about 200 W/(m‧K), as shown in FIG. 9, when the columnar portion 2 is perpendicular to the longitudinal direction 30, the distance is heated. 4 When the width 5 of the nearest portion (in other words, the width 5 of the heating surface 4) is 10 mm to 12 mm, and the width 6 of the portion farthest from the heating surface 4 is 8 mm to 10 mm, the heat dissipation property is the highest. result.

In the graph of Fig. 9, the horizontal axis represents the width of the columnar portion 2, and the vertical axis represents the thermal resistance normalized by the minimum value of the thermal resistance. In FIG. 9, the upper right curve indicates the analysis result of the width dependence of the portion of the columnar portion 2 closest to the heat receiving surface 4; and the lower left curve indicates that the columnar portion 2 is heated by the heating surface 4 When the width of the nearest portion becomes the optimum value of 11 mm, the result of the analysis of the width dependence of the portion of the columnar portion 2 farthest from the heated surface 4 is obtained. Further, in order to promote heat dissipation by radiation, the surface of the aluminum is preferably subjected to blackening treatment such as oxygen aluminum.

In the case of copper having a high heat transfer coefficient, as shown in FIG. 10, the width 5 of the portion closest to the heat receiving surface 4 in the cross section perpendicular to the longitudinal direction 30 of the columnar portion 2 is 8 mm to 10 mm, and When the width 6 of the portion farthest from the heating surface 4 is 2 mm to 5 mm, the heat dissipation characteristics are the highest. In FIG. 10, the upper right curve indicates the analysis result of the width dependence of the portion of the columnar portion 2 closest to the heat receiving surface 4; and the lower left curve indicates that the columnar portion 2 is heated by the heating surface 4 When the width of the nearest portion becomes the optimum value of 9 mm, the result of the analysis of the width dependence of the portion of the columnar portion 2 farthest from the heated surface 4 is obtained.

The heat radiating surface parallel fin type flat heat radiating structure 1 can effectively use the space in the direction parallel to the heat receiving surface 4. Therefore, when heat is dissipated to the CPU or the like mounted on the daughterboard of the mother board, as long as the area of the wide plate-shaped heat sink 3 is ensured as much as possible, as shown in FIG. 11, the side of the heat receiving surface 4 is observed. The shape of the heat dissipation structure is substantially the same as the shape of the main surface of the sub-board, and is disposed opposite to the main surface of the sub-board, thereby achieving higher heat dissipation characteristics.

Fig. 11 is a view showing a fifth embodiment of a heat radiating surface parallel fin type flat heat dissipating structure according to the present invention. In this embodiment, as shown in FIG. 12, when the heat receiving surface parallel fin type flat heat dissipation structure 1 is attached to the sub-board 7, a spring-attached screw 8 is used. Further, by using the heat-radiating parallel foam type flat heat dissipation structure 1 having the plate-shaped fins 3 having a wide area, as shown in FIG. 13, the heat-generating component 11 on the sub-board 7 can be made by one heat dissipation structure. 12, 12 unified heat dissipation, which can reduce the number of parts and reduce assembly time. Further, reference numeral 9 in Fig. 12 denotes a spring, and reference numeral 10 denotes a nut.

Fig. 13 is a view showing a sixth embodiment of the heat radiating surface parallel fin type flat heat dissipating structure according to the present invention. In Fig. 13, reference numeral 11 denotes a heat generating component having the highest heat generation density, and reference numeral 12 denotes a heat generating component having a low heat generation density. Symbol 13 is a thermally conductive interface material. A heat conductive interface material 13 such as a heat transfer oil, a heat conductive adhesive, or a heat conductive sheet is introduced between the heat radiating surface of the heat generating component 11 having the highest heat generation density such as a CPU and the heat receiving surface of the heat sink surface parallel heat radiating structure 1 . . It is preferable to minimize the gap between the heat generating component 11 having the highest heat generation density and the heat receiving surface 4, and to efficiently dissipate heat from the heat generating component 11 having the highest heat generation density such as the CPU. On the other hand, the heat generating component 12 having a low heat generation density can sufficiently dissipate heat even if the heat conductive interface material is relatively thick, so that it is not necessary to narrow the interval.

Fig. 14 is a view showing a seventh embodiment of the heat radiating surface parallel fin type flat heat dissipating structure according to the present invention. In Fig. 14, reference numeral 14 is a (thick) part having a larger thickness than the heat generating component 11 having the highest heat generation density. Symbol 15 is a concave recess. When there is a part 14 having a thickness larger than the heat generating component 11 having the highest heat generation density which is the most heat-dissipating in the region covered by the fin-shaped flat heat dissipating structure 1 having the heat receiving surface, the heat generating component 11 having the highest heat generation density is present. The gap between the heat dissipating surface and the heat receiving surface 4 is minimized. As shown in FIG. 14, the heat receiving surface of the fin-shaped flat heat dissipating structure 1 is parallel to the heating surface in a region corresponding to the part 14 having the large thickness. The concave portion 15 is formed in the concave shape to reduce the thermal resistance between the heat generating component 11 having the highest heat generation density and the heat receiving surface.

In order to mount the heat-receiving surface parallel heat sink type flat heat dissipation structure 1 on the mother board or the daughter board in a state in which the heat receiving surface 4 is in contact with the heat generating component, the following method may be employed: the heat conductive adhesive is used as shown in FIG. The heat-receiving surface parallel fin-type flat heat dissipation structure 1 which is not additionally processed is bonded to the mother board or the daughter board. However, since the area of the heat receiving surface 4 is wide, it may be difficult to perform reworking. Therefore, as illustrated in FIGS. 11 and 12, the bottom plate of the general heat sink type heat sink (refer to FIG. 18) may be omitted. The plate-like fins 3 closest to the heated surface are mounted by a generally spring-loaded screw. At this time, as a heat transfer The interface material can be easily subjected to secondary processing by using a heat transfer oil or a heat conduction sheet or the like. Further, as shown in FIGS. 15A, 15B, and 16, in order to reduce the number of assembling steps, a clip composed of the plate-like elastic member 17 may be used.

Fig. 15A and Fig. 15B are views showing an eighth embodiment of the heat radiating surface parallel fin type flat heat radiating structure according to the present invention. A groove 16 is formed in the heat radiating surface parallel fin type flat heat radiating structure 1.

Fig. 16 is a view showing a plate-shaped elastic member 17 used in the eighth embodiment of the heat-radiating parallel fin type flat heat-dissipating structure according to the present invention. By heating the plate-like elastic member 17 along the groove 16 of the heat-radiating surface parallel fin-type flat heat dissipation structure 1 shown in FIGS. 15A and 15B, the heat shown in FIGS. 15A and 15B is heated. The surface-parallel fin-type flat heat dissipation structure 1 is mounted on the sub-board 7. Since the heat-receiving surface-parallel fin-shaped flat heat dissipation structure 1 is attached to the sub-board 7, the plate-like elastic member 17 is used, so that it can be easily attached and detached. Further, reference numeral 13 in Fig. 16 is a hook portion.

Further, in order to achieve low cost, the present invention is preferably a structure in which the main structure is not subjected to cutting, and can be integrally molded by a extrusion molding method or a drawing forming method, and has a structure with less additional processing.

1‧‧‧Flat surface heat sink type flat heat dissipation structure

2‧‧‧ Column

2a, 2b, 2c, 2d‧‧‧ side of the columnar part

3‧‧‧ Plate heat sink

4‧‧‧ Heating surface

5‧‧‧The width of the portion of the column that is closest to the heated surface

6‧‧‧The width of the portion of the column that is furthest from the heated surface

7‧‧‧ daughter board

8‧‧‧Spring-loaded screws

9‧‧‧ Spring

10‧‧‧ nuts

11, 12‧‧‧Heat parts

13‧‧‧Heat conductive interface material

14‧‧‧Thick parts

15‧‧‧ recess

16‧‧‧ trench

17‧‧‧ Plate-like elastic members

18‧‧‧Cut hook

19‧‧‧floor

20‧‧‧Vertical heat sink type radiator

21‧‧‧heated block

22‧‧‧heat pipe

23‧‧‧Separate radiator

30‧‧‧The long axis direction of the columnar part

31, 33‧‧‧ dotted line

32‧‧‧dash

H‧‧‧ Height of heat sink structure

L‧‧‧Deep depth of heat sink structure

Ratio of thermal resistance of R‧‧‧ heated surface parallel fin type flat heat dissipation structure to thermal resistance of vertical heat sink type heat sink

Tr‧‧‧Thermal resistance

Tr(min)‧‧‧Thermal resistance

W‧‧‧Width of heat sink structure

Fig. 1 is a perspective view of the first embodiment of the heat-radiating parallel fin type flat heat-dissipating structure according to the present invention as seen from the heating surface side.

Fig. 2 is a perspective view of the heat-radiating surface parallel fin-shaped flat heat dissipation structure of Fig. 1 as viewed from a side opposite to the heat receiving surface thereof.

Fig. 3A is a cross-sectional view showing the heat-receiving surface parallel fin-type flat heat dissipation structure of Fig. 2 cut at a dash line 32-32.

Fig. 3B is an enlarged view of the columnar portion 2 of the heat radiating surface parallel fin type flat heat radiating structure of Fig. 3A.

Fig. 4 is a view for explaining the heat radiating performance of the heat sink parallel fin type flat heat dissipating structure shown in Fig. 1 beyond the vertical fin type heat sink shown in Fig. 18.

5 is a contour line of the relative thermal resistance of the plate-shaped fins in the heat-radiating parallel fin type flat heat-dissipating structure, which is obtained by analysis, and the plate-like fins 3 The optimum range of plate thickness and spacing.

Fig. 6 is a view showing a second embodiment of a heat radiating surface parallel fin type flat heat radiating structure according to the present invention.

Fig. 7 is a view showing a third embodiment of a heat radiating surface parallel fin type flat heat radiating structure according to the present invention.

Fig. 8 is a view showing a fourth embodiment of the heat radiating surface parallel fin type flat heat radiating structure according to the present invention.

Fig. 9 is a view showing that when the heat radiating surface parallel fin type flat heat dissipating structure is an aluminum alloy, it is determined by analysis that the portion of the columnar portion closest to the heat receiving surface and the farthest portion are opposed to the standardized thermal resistor. Width dependence.

Fig. 10 is a view showing that when the heat radiating surface parallel fin type flat heat dissipating structure is made of copper, it is determined by analysis that the portion of the columnar portion closest to the heat receiving surface and the farthest portion are opposed to the standardized thermal resistance. Width dependence.

Fig. 11 is a perspective view showing a fifth embodiment of the heat-radiating parallel fin type flat heat dissipation structure according to the present invention.

Fig. 12 is a cross-sectional view showing the vicinity of the spring-loaded screw when the heated surface parallel fin type flat heat dissipating structure of Fig. 11 has been mounted on a daughterboard using a spring-loaded screw.

Figure 13 is a cross-sectional view showing a sixth embodiment of a heat-radiating parallel fin type flat heat-dissipation structure according to the present invention, which is perpendicular to the heat-receiving surface along the long axis of the columnar portion; and for ease of understanding, compared with Zoom in horizontally and vertically.

Figure 14 is a cross-sectional view showing a seventh embodiment of a heat-radiating parallel foam type flat heat dissipation structure according to the present invention, which is perpendicular to the heat receiving surface along the long axis of the columnar portion; and for ease of understanding, compared with Zoom in horizontally and vertically.

Fig. 15A is a plan view showing the eighth embodiment of the heat-radiating parallel foam type flat heat dissipation structure according to the present invention, as viewed from the opposite side of the heat receiving surface.

Fig. 15B is a side view of the heat radiating surface parallel fin type flat heat radiating structure of Fig. 15A.

Fig. 16 is a perspective view showing one embodiment of a plate-shaped elastic member used in the eighth embodiment of the heat-radiating parallel fin type flat heat dissipation structure according to the present invention.

Fig. 17 is a perspective view showing a state in which the heat receiving surface parallel fin type flat heat dissipating structure of Fig. 15 is attached to the sub-board by using the plate-like elastic member of Fig. 16.

Fig. 18 is a perspective view of a conventional vertical fin type heat sink in which a plurality of plate fins are arranged in a direction perpendicular to the heat receiving surface from the bottom plate.

Fig. 19 is a perspective view of a conventional heat sink in which a heat receiving block and a plate fin are connected by a heat pipe.

1‧‧‧Flat surface heat sink type flat heat dissipation structure

2‧‧‧ Column

3‧‧‧ Plate heat sink

4‧‧‧ Heating surface

5‧‧‧The width of the portion of the column that is closest to the heated surface

30‧‧‧The long axis direction of the columnar part

31‧‧‧ dotted line

H‧‧‧ Height of heat sink structure

L‧‧‧Deep depth of heat sink structure

W‧‧‧Width of heat sink structure

Claims (2)

A heat radiating surface parallel fin type flat heat dissipating structure is composed of a columnar portion extending along a long axis direction and having at least three sides parallel to a long axis, and one of the side faces is heated And a plurality of plate-shaped fins extending from a first side other than the side surface of the columnar portion that is the heating surface, and a first direction parallel to the heating surface and a second direction opposite thereto; The height H (unit: mm) of the heat-radiating surface parallel fin-type flat heat dissipation structure is a distance from the heat receiving surface to a plate-shaped heat sink farthest from the heat receiving surface, and the width is set W (unit: mm) is a distance from the front end of the plate-shaped fin extending in the first direction from the columnar portion to the front end of the plate-shaped fin extending in the second direction from the columnar portion, The relationship between H and W is expressed by the following equation: H≦(W-47) ^0.5 /0.6+5, where H is 5 mm or more and W is 47 mm or more; the material of the heat radiating surface parallel fin type flat heat dissipating structure Aluminum or aluminum alloy having a thermal conductivity of 180 W/(m.K) or more; and along the long axis In the extended columnar portion, the width of the portion closest to the heat receiving surface, that is, the width of the heat receiving surface is set to 10 mm to 12 mm, and the width of the portion farthest from the heat receiving surface is set to 8 mm to 10 mm. A heat radiating surface parallel fin type flat heat dissipating structure is composed of a columnar portion extending along a long axis direction and having at least three sides parallel to a long axis, and one of the side faces is heated And a plurality of plate-shaped fins extending from a first side other than the side surface of the columnar portion that is the heating surface, and a first direction parallel to the heating surface and a second direction opposite thereto; The height H (unit: mm) of the heat-radiating surface parallel heat sink type flat heat dissipation structure is a distance from the heat receiving surface to a plate-shaped heat sink farthest from the heat receiving surface, and the width is set W (unit: mm) is a distance from the front end of the plate-shaped fin extending in the first direction from the columnar portion to the front end of the plate-shaped fin extending in the second direction from the columnar portion, The relationship between H and W is expressed by the following equation: H≦(W-47) ^0.5 /0.6+5, where H is 5 mm or more and W is 47 mm or more; the material of the heat radiating surface parallel fin type flat heat dissipating structure a copper or copper alloy with a thermal conductivity above 350 W/(m.K); and along the long axis The cylindrical portion extending away from the nearest portion of the width of the heating surface, i.e. the width of the heating surface is set to 8mm ~ 10mm, and the width is set furthest away from the heat receiving face portion 2mm ~ 5mm.