JPH0955457A - Heat sink and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a heat sink superior in heat dissipation property and to make it possible to manufacture the heat sank easily and at low cost. SOLUTION: A heat sink is constituted into such a structure that a plurality of sheets of fins 2 are provided into an alignment shape, each one pair of the adjacent fins 2 are bonded together at a plurality of places in such a way that the bonding positions of the fins 2 in the direction of extension of the fins 2 are alternated on the surface and rear of each fin 2, a plurality of cylindrical air ducts 5 with a section formed into a polygon shape are respectively formed of each one pair of the adjacent fins 2 at sites, where the fins are not bonded to each other, in such a way that the air ducts 5 are formed into a honeycomb shape as a whole, a slit 4, which communicates with each air duct 5, is formed in a part, which is positioned in the vicinity of a substrate 1, of each fin 2, whereby the heat reception and heat dissipation of the heat sink can be efficiently conducted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat sink used for radiating heat from various devices and the like and, more particularly, to a heat sink excellent in heat dissipation and a method for easily and inexpensively manufacturing the heat sink. .

[0002]

2. Description of the Related Art As shown in FIGS. 5 to 8, a conventional heat sink has a structure in which a pin-shaped or thin-plate-shaped fin 2 is fixed to one surface of a plate-shaped substrate 1 such as a microcomputer and an audio device. When it is used inside the
On the surface of the substrate 1 opposite to the side where the fins 2 are fixed, a CPU (Central Pro) as shown in FIG.
The processing unit 6 and the like are mounted, and a fan (not shown) that blows air for cooling is arranged between the fins 2. And the CPU 6
When heat is generated by the operations such as the above, the heat is transmitted to the fins 2 by the substrate 1 and is blown from the fan to the fins 2 between the fins 2 and the wind. Effective heat conversion is performed to dissipate heat from the fins 2 to prevent the CPU 6 from rising in temperature.

More specifically, the heat sink shown in FIG. 5 is one in which pin fins 2 formed in a substantially cylindrical shape are erected on the substrate 1. Although the pin fin 2 has a cylindrical shape here, it may have a rectangular prism shape as shown in FIG.

A method of manufacturing such a heat sink is manufactured by forging or casting. For example, by pressing a forging die having a plurality of pin-shaped holes against a substrate 1 having a predetermined thickness and made of a metal material, the substrate 1
The pin fins 2 are formed so as to project therefrom. Further, the square columnar pin fin 2 can be manufactured by cutting.

On the other hand, the heat sink shown in FIG.
The plate-like fins 2 are erected substantially parallel to each other on the upper surface of the plate at predetermined intervals so as to form a comb tooth shape. This heat sink is manufactured by cutting.

Further, the heat sink shown in FIG. 7 has corrugated fins 2 called corrugated fins 2 joined to the substrate 1 by an adhesive or brazing. This is a heat sink having fins 2 each having a large surface area, which is formed by bending a thin plate in a curved shape so as to be spaced apart from each other by a predetermined length.

[0007]

However, in the heat sink and the manufacturing method thereof shown in FIGS. 5 and 8 described above, the diameter of the pin fins 2 and the distance between the pin fins 2 with respect to the height of the pin fins 2 are different from each other. Is limited to some extent, and it is difficult to manufacture the pin fin 2 having a large height. Therefore, there is a limit in increasing the surface area required for heat dissipation. further,
The method of manufacturing the heat sink by the forging method has a problem that the cost for manufacturing the mold is high and the burden of initial investment is large.

Further, in the heat sink and the manufacturing method thereof shown in FIG. 6 described above, since the manufacturing method by cutting is used, the workability is good and the restriction on the height of the fin 2 is relatively loose. Even if cutting is performed at a high speed so as not to apply a load to the cutting machine, it is necessary to perform the cutting at a sufficiently low feed rate, which takes time, and most of the material is discarded, resulting in waste.

Further, in the heat sink and the manufacturing method thereof shown in FIG. 7, since the corrugated fins 2 can be stacked, there is no limitation on the height, and the material cost is low, but there is an advantage. There is a limit to the ratio between the height and the distance between the fins 2. Further, the fan cannot blow air from above the fins 2, and the air must be blown from only one lateral direction, resulting in poor heat dissipation efficiency. There is a problem that the temperature of the air near the outlet becomes high.

The present invention has been made in view of the above problems, and an object thereof is to provide a heat sink which is excellent in heat dissipation and can be manufactured easily and inexpensively, and a manufacturing method thereof.

[0011]

In order to achieve the above-mentioned object, a heat sink according to claim 1 of the present invention has a plurality of fins arranged in an array, and each pair of adjacent fins is A cylindrical shape in which the fins are joined at a plurality of places such that the joining positions in the extending direction of the fins are alternated, and a pair of adjacent fins that are not joined together form a polygonal cross section. By forming a plurality of ventilation passages so as to have a honeycomb shape as a whole, and forming a slit communicating with the ventilation passages in each fin in the vicinity of the substrate, it is possible to efficiently receive and radiate heat. It has a feature.

The heat sink according to claim 2 is
In the first aspect, the ventilation passage formed between the fins has a hexagonal cross section, and the surface area of a portion capable of receiving and radiating heat can be sufficiently secured.

The heat sink according to claim 3 is
In the first or second aspect, the slit is formed at the end of the fin in contact with the substrate so that the heat received by the substrate can be radiated more efficiently.

According to a fourth aspect of the heat sink manufacturing method of the present invention, a plurality of flat plate fins are arranged in an array,
Each pair of adjacent fins is connected so that the fins are joined at a plurality of positions on the front and back surfaces of the fins alternately in the extending direction of the fins, and the fins are sequentially joined. A plurality of slits are formed in the vicinity of one side edge at intervals in the extending direction of each fin, and two fins exposed at both ends of the plurality of fins are used as a pair of adjacent fins. 1 adjacent to each of the parts that are expanded so as to form a plurality of ventilation paths and are not joined to each other
The tubular ventilation passage having a polygonal cross section between the pair of fins is formed so as to have a honeycomb shape, and the side edges of each fin on the slit side are fixed to the substrate to further improve the heat radiation effect. The feature is that a heat sink having a high shape can be manufactured easily and inexpensively.

According to a fifth aspect of the present invention, in the heat sink manufacturing method according to the fourth aspect, the fins are joined so that the distance of the non-joined portion in the extending direction of the fin is the same as the distance of the joined portion. It is characterized in that a heat sink having a larger surface area for receiving and radiating heat is manufactured.

A heat sink manufacturing method according to a sixth aspect of the present invention is characterized in that, in the fourth or fifth aspect, the slit is formed in the non-joint portion to manufacture a heat sink having a higher heat dissipation effect.

A heat sink manufacturing method according to a seventh aspect is the method of manufacturing a heat sink according to any one of the fourth to sixth aspects, wherein a slit is formed at an end portion in contact with the substrate, and a heat dissipation effect is provided at a position close to the substrate. It is characterized by manufacturing a heat sink that enhances

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIG.
This will be described with reference to FIGS.

FIG. 1 is a diagram showing an embodiment of a heat sink of the present invention. This heat sink is made of a material having a high thermal conductivity such as aluminum, and a plurality of thin plate-like fins 2 are arranged on one surface of the flat plate-like substrate 1 by brazing, soldering, or an adhesive. Is joined to. Each pair of these adjacent fins 2 is joined at an arbitrary joining width X with an adhesive or the like at a plurality of positions such that the joining positions in the extending direction of the fins 2 are alternately arranged on the front and back surfaces of each fin 2. ing. Here, the extending direction of the fins 2 means the longitudinal direction of the fins 2 parallel to the substrate. Also,
The joint portion 3 of each fin 2 corresponds to the substrate 1 of the fin 2.
If the adhesive is applied to one surface of the fin 2, the entire surface of the fin 2 in a direction orthogonal to the surface of the fin 2 is applied, and if the adhesive is applied to one surface of the fin 2, the next surface is separated from the bonding surface by the bonding width X. The joint surface is formed repeatedly. Here, the reason why the joint part 3 may be partially formed is that the fins 2 do not have to be joined to each other when they are finally formed as heat sinks, and they are separated from each other. This is because the effect of the present invention is not adversely affected even if it does. Then, the tubular ventilation path 5 is bent at the ends of the joints 3 thus joined, and has a regular hexagonal cross section between the pair of adjacent fins 2 which are not joined to each other. Are formed in a honeycomb shape as a whole.

Further, the blown air is discharged to the non-joint portion of each fin 2 which is in contact with the substrate 1 and is not joined to the adjacent fin 2, thereby enhancing the heat radiation effect. A slit 4 for connecting with the ventilation passage 5 is formed. The slit 4 is formed so as to penetrate from one side to the other side when viewed from the side, and the air blown by a fan or the like flows smoothly from above the fin 2 to below the fin 2 and passes through the slit 4. The heat is emitted laterally to enhance the heat dissipation effect.

Further, as described above, the joint portion 3 of each fin 2 is provided.
The entire surface or a part thereof is bonded by an adhesive agent or the like. This may be bonded at the time of disposing the fin 2 on the substrate 1, and each bonding portion 3 due to the influence of heat or the like during use. Even if the joining force of 1 is reduced and the fins 2 are separated from each other, the heat radiation effect is not adversely affected. Therefore, the adhesive in this portion does not need to be a heat-resistant adhesive, and an inexpensive adhesive can be used.

Further, although the interval between each joining part 3 and the next joining part 3 is formed to be substantially the same as the joining width X, it is not limited to this interval and may be arbitrarily set. The gap between the fins 2, that is, the shape of the ventilation passage 5 is not limited to the regular hexagon, and the width of the gap between the fins 2 may be narrowed to form a flat hexagon, or conversely, between the fins 2. The width of the gap may be widened to be extremely close to a quadrangle, as long as the surface area of the fin 2 serving as a heat radiation portion can be increased.

Further, the slits 4 formed in the fins 2 are formed at the end portions on the side in contact with the substrate 1 so that the air blown can flow to a position near the heat generating portion as much as possible to enhance the heat radiation effect. However, the position where the slit 4 is formed is not limited to this position. If the slit 4 is in the vicinity of the substrate 1, the slit 4 is formed at a position slightly separated from the substrate 1 so that the fin 2 is stable on the substrate 1. It may be taken into consideration that the fins 2 of FIG.
The slits 4 may be formed at a plurality of positions in the vertical direction.

Even if the heat sink is provided with screw holes (through holes) for disposing the CPU 6 and the like from the substrate 1 to above the fins 2, the heat dissipation effect is great. There is no effect.

In this embodiment of the heat sink of the present invention, the substrate 1 receives heat from the heat generating portion such as the CPU 6 arranged on the lower surface of the substrate 1 and conducts the heat to the fins 2. Usually, a fan is separately arranged on the heat sink, and therefore when the fan blows air to the fins 2 from above or laterally of the fins 2,
This air passes through the ventilation passage 5 and the slit 4, and the heat is released from the fin 2 to the outside.

Therefore, according to the embodiment of the heat sink of the present invention, the ventilation passages 5 and the slits 4 which allow the air blown by the fan to pass smoothly while ensuring a sufficient surface area of the fins 2 for heat conduction are provided. Since it has, it can exhibit an excellent heat dissipation effect.

Further, the surface area of the fins 2 necessary for receiving and radiating heat, and the ventilation path 5 for passing the air to be blown
Since the shape of the slit 4 can be freely changed, a heat sink having the fins 2 having a higher heat dissipation effect can be obtained.

Further, since the hexagonal ventilation passages 5 formed between the fins 2 are formed in regular hexagons and the fins 2 are arranged more densely, the surface area of the fins 2 required for heat reception and heat dissipation is reduced. Since the slit 4 is formed in the vicinity of the substrate 1 and air is blown to a place closer to the heating element, the heat dissipation effect can be improved.

Next, an embodiment of the heat sink manufacturing method of the present invention will be described with reference to FIGS.

In the first step, as shown in FIG. 2, a plurality of flat plate-like fins 2 made of a metal material having a high thermal conductivity such as aluminum are arranged in an array, and a pair of adjacent fins is provided. The fins 2 are joined by joining means such as an adhesive, brazing, or soldering at a plurality of locations such that the joining positions in the extending direction of the fins 2 are alternately arranged on the front and back surfaces of each fin 2. Are connected so that they are sequentially joined. At this time, the joint portions 3 are partially or entirely joined to each other in the vertical direction of the fin 2. here,
The reason why the joint portion 3 may be partially joined is that the fins 2 are joined together at the stage of forming the heat sink, and they are separated from each other when finally formed as the heat sink. This is because it may be in a state. Further, the non-joined portion of the fin 2 which is not joined may be an arbitrary distance, and as an example, it is formed with the same distance X as the joined portion 3 in FIG.

Next, as a second step, as shown in FIG. 3, one side edge of each fin 2 is cut by a cutting machine with respect to a plurality of the fins 2 which are connected in one stack of each fin 2. Plural slits 4 are formed in the vicinity in the extending direction of each fin 2 at intervals. Here, at one end of the fin 2, a slit 4 is formed at the position of the non-bonded portion, the slit 4 penetrating to the opposite surface. This slit 4 is a fin 2
When used as a heat sink, the air passage communicates with the ventilation passage 5 and serves as a passage for air blown from the fan.

Next, as a third step, as shown in FIG. 4, the fins 2 exposed at both ends of the plurality of fins 2 are exposed.
A plurality of ventilation passages 5 are provided on a pair of adjacent fins 2 with one fin 2
A cross-sectional polygonal shape due to the space between each pair of adjacent fins 2 which are not joined to each other.
Here, the tubular ventilation passage 5 having a regular hexagonal cross section is formed so as to have a honeycomb shape as a whole. Then, the heat sink is completed by joining the side edges of the fins 2 on the side of the slits 4 to the plate-shaped substrate 1 by brazing or the like. The joining method at this time is preferably brazing or soldering, but an adhesive that is strong and has high heat resistance should be used.

The cross-sectional shape of the ventilation passage 5 formed by expanding the fins 2 is not limited to a regular hexagon, and the separation width between the fins 2 may be narrowed to form a flat hexagon. On the contrary, the separation width between the fins 2 may be widened to be extremely close to a quadrangle, as long as the honeycomb shape is formed as a whole and the heat dissipation efficiency is higher.

Further, the slit 4 is provided with the fin 2
The non-joint portion is formed so as to penetrate therethrough, and four slits 4 are formed in one hexagon so that a large number of air circulation paths are formed. 3, the slits 4 may be formed at two positions in one hexagon so that the fins 2 in contact with the substrate 1 have a large surface area for receiving and radiating heat.

Furthermore, a plurality of the slits 4 may be formed in the middle portion of the fin 2 instead of the end portions thereof.

According to the embodiment of the method for manufacturing the heat sink of the present invention as described above, the height of the fins 2 is not limited, and the distance between the adjacent fins 2 can be easily and freely changed. Therefore, it is possible to easily manufacture a heat sink having a shape with higher heat dissipation efficiency. Further, the cost of a jig or the like required to form the fin 2 can be low, and the heat sink can be manufactured at a low cost in terms of material cost and processing cost because there are few parts to be discarded at the time of cutting.

The present invention is not limited to the above-mentioned embodiment, but various modifications can be made as necessary.

For example, in the embodiment of the method for manufacturing a heat sink of the present invention, the fin 2 has a size which can be used as it is for the heat sink.
The fins 2 may be joined together and then cut into a desired size for use.

[0039]

As described above, the heat sink according to the present invention has an excellent effect that it can radiate heat more efficiently. Further, the method for manufacturing a heat sink according to the present invention has extremely high practicality that a heat sink having an excellent heat dissipation effect can be manufactured easily and inexpensively.

[Brief description of drawings]

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

FIG. 2 is an explanatory view showing an embodiment of a method for manufacturing a heat sink according to the present invention.

FIG. 3 is an explanatory view showing an embodiment of a method for manufacturing a heat sink according to the present invention.

FIG. 4 is an explanatory view showing an embodiment of a method for manufacturing a heat sink according to the present invention.

FIG. 5 is an explanatory diagram showing a conventional heat sink.

FIG. 6 is an explanatory view showing a conventional heat sink.

FIG. 7 is an explanatory view showing a conventional heat sink.

FIG. 8 is an explanatory view showing a conventional heat sink.

[Explanation of symbols]

 1 Substrate 2 Fin 3 Joint 4 Slit 5 Ventilation path 6 CPU

Claims (7)

[Claims] 1. A plurality of fins are fixed to one surface of a substrate,
In a heat sink that transfers the heat transferred to the substrate to the fins and radiates the heat from the fins to the outside, a plurality of the fins are arranged in an array, and each pair of adjacent fins is connected to each fin. Cylindrical ventilation passage having a polygonal cross-section with a pair of adjacent fins that are not joined to each other and are joined at a plurality of places such that the joining positions of the fins on the front and back sides are alternated. 2. A heat sink characterized in that a plurality of them are formed so as to have a honeycomb shape as a whole, and a slit communicating with the ventilation passage is formed in each fin near the substrate. 2. The heat sink according to claim 1, wherein the ventilation passage has a hexagonal cross section. 3. The heat sink according to claim 1, wherein the slit is formed in an end portion of the fin that is in contact with the substrate. 4. A plurality of flat plate-shaped fins are arranged in an array, and adjacent pairs of fins are arranged such that the joining positions in the extending direction of the fins are alternated on the front and back surfaces of each fin. The fins are connected to each other so as to be sequentially joined to each other, and a plurality of slits are formed near one side edge of each fin at intervals in the extending direction of each fin,
Of the plurality of fins, two fins exposed at both ends are expanded so that a plurality of ventilation passages are formed in a pair of adjacent fins, and adjacent fins are not joined to each other. The tubular ventilation passage having a polygonal cross-section is formed between the pair of fins so as to have a honeycomb shape as a whole, and side edges of the fins on the slit sides are fixed to the substrate. Manufacturing method of heat sink. 5. The method for manufacturing a heat sink according to claim 4, wherein the fins are joined so that the distance between the non-joined portions in the extending direction of the fins is the same as the distance between the joined portions. 6. The method for manufacturing a heat sink according to claim 4, wherein the slit is formed in the non-bonded portion. 7. The method for manufacturing a heat sink according to claim 4, wherein the slit is formed at an end portion in contact with the substrate.