JPH08321696A - Heat dissipating fin for cooling electronic equipment and electronic equipment equipped therewith - Google Patents

Abstract

PURPOSE: To enable heat released from a semiconductor element to be efficiently dissipated into an ambient atmosphere by a method wherein one or more through-holes are provided to the heat dissipating surface of a fin so as to enhance air located between a mounting surface of a heat releasing body such as a semiconductor element and the fin in mobility. CONSTITUTION: Semiconductor devices 50 to 52 are located on a board 30 inside a case 70, and a heat dissipating fin 20 where through-holes 10 are bored is formed on the semiconductor device 50 through the intermediary of a conductive member. Then, convective warm air on the surface of board 30 around the semiconductor device 50 is enhanced in mobility to the outside. The fin 20 is slightly lessened in heat dissipating area by the through-holes 10 provided to its surface, but the inner air is enhanced in mobility, so that the fin 20 is capable of more efficiently dissipating heat into an ambient atmosphere than a conventional flat plate. The fin 20 hardly restrains heat released from both the semiconductor device 52 mounted under the fin 20 and the surface of the board 30 from being dissipated, so that, the fin 2O is capable of efficiently dissipating not only heat released from the semiconductor device 50 which is kept in contact with it but also heat released in all region below the film 20 into an surrounding air.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiator fin for cooling electronic equipment and an electronic equipment using the same.

[0002]

2. Description of the Related Art As a conventional fin for radiating small electronic devices, a laminated plate (FIG. 2 (a)) or a pin fin (FIG. 2 (b)) is used on the surface of a semiconductor element and a package inside the electronic device. . Further, in Japanese Patent Laid-Open No. 6-5751,
Porous metal foam is used as a radiation fin.

[0003]

The conventional heat radiation fins and porous metal foams have a large fin height with respect to the substrate stacking space when used in a narrow space such as inside a small electronic device. There was a problem that it could not be installed. Further, even if the fins are short, if they are installed in a narrow space, flow resistance is generated, the flow rate to the fins is reduced, and efficient cooling cannot be performed.

An object of the present invention is to provide a cooling structure for a heating element such as a semiconductor element mounted in a narrow space with high density.
Another object of the present invention is to provide a cooling structure that efficiently diffuses heat generated from a semiconductor element to the surroundings and keeps the semiconductor element at a predetermined temperature.

[0005]

In order to achieve the above-mentioned object, the heat radiation fin of the present invention includes a single or a plurality of heat radiation surfaces so that air between the heat element mounting surface such as a semiconductor element and the fins can easily flow. Through holes are provided. In addition to natural cooling, small fins are attached to the edges of the through holes to efficiently transfer heat during forced convection cooling.
Made the air easy to flow.

[0006]

Since the radiation fin of the present invention has a flat plate shape, electronic boards having a heating element such as a semiconductor substrate are closely stacked,
This is effective when the heat radiation space of the space is significantly limited. When the semiconductor element on the electronic substrate generates heat in a narrow space, a high temperature portion is generated on the electronic substrate around the semiconductor element as well as on the semiconductor element surface. The heat dissipation fin of the present invention provided on the semiconductor element surface has a through hole provided on the fin surface to reduce the heat dissipation area itself of the heating element that is in contact, but the high temperature air that should originally be hidden on the electronic substrate surface around the heating element. Since the layer can be discharged onto the fin surface, the electronic substrate can be cooled more efficiently than the flat plate fin. Furthermore, in the above-mentioned through hole, air can be moved through the through hole in an extremely narrow space where natural convection does not occur, and convection occurs, so efficient cooling can be performed. When the electronic board is subjected to forced convection cooling with a fan or the like, the radiating fins of the present invention serve as a wind passage for efficiently cooling the heating element on the electronic board, and when there is no through hole, the wind flows. Since it is difficult to blow air to the vicinity of the base of the semiconductor element, which is a heating element, more efficient cooling is possible.

[0007]

EXAMPLE FIG. 1 shows an example of an electronic device using the radiation fin of the present invention. In an electronic device, a substrate 30 on which a plurality of semiconductor elements are mounted is arranged in a narrow space surrounded by a keyboard 90 and a case 70. The figure shows a plurality of semiconductor elements 50 randomly mounted on a substrate 30 in a small housing 70.
There is 52, and by the radiation fin 20 that is in contact with the surface of the semiconductor element 50, which is a heating element that generates a large amount of heat, via a conductive member,
It has a structure for radiating heat generated in the semiconductor element 50. The radiating fin 20 is provided with a plurality of through holes 10 so that warm air staying on the substrate surface near the semiconductor element 50 can easily flow to the outside. Although the heat radiation area of the fin is somewhat reduced by the through hole 10 provided in the fin surface, since the flow of the internal air is promoted, the heat radiation can be performed more efficiently than the ordinary flat plate. Further, since the heat radiation from the semiconductor element 52 mounted under the heat radiation fin 30 and the surface of the substrate is not hindered, not only the semiconductor element 50 in contact therewith but also the entire fin lower surface can be efficiently cooled. Such a radiation fin 20 with the through hole 10 can be easily manufactured by punching a large metal flat plate into an arbitrary shape, for example, a circular shape, and cutting it into a free size.

FIG. 3 shows an embodiment of the radiation fin of the present invention. FIG. 3A shows a structure in which the through hole 10 on the surface of the heat dissipation fin is not provided on the contact surface with a heating element such as a semiconductor element. By not providing through-holes on the fin surface and the heating element surface, the amount of heat transferred from the heating element surface to the fin surface increases, so that heat dissipation from the substrate and other heat-generating components as described above is not hindered and efficient. Can be cooled to. In addition, FIG.
This is a structure in which the edges of the through holes are formed at the ends of all the radiation fins. The edge length at the end of the fin having a high heat transfer coefficient is increased, and the overall heat dissipation capability can be improved.

FIG. 4 shows another embodiment of the radiation fin of the present invention. In the figure, the heat radiating surface provided with the through holes 10 is inclined upward or downward with respect to the contact surface with a heating element such as a semiconductor element as shown in (a) or (b). Since the natural convection heat transfer is promoted by providing the inclination at the end of the heat radiation surface, the cooling performance can be improved. Further, in the structure in which air is blown from the side surfaces of the fins to cool the heating element, air flows through the through holes from the front to the back or from the back to the front and is blown to the root of the heating element, and the air blowing path can be arbitrarily adjusted. The surface of the substrate on which a large number of semiconductor elements are mounted can be efficiently cooled. The fins 23 and 24 having such an inclination can be manufactured by pressing a heat radiation fin as shown in FIG. Since it is a fin used in a narrow space, it cannot be tilted so much, and therefore a large number of irregularities may be provided.

FIG. 5 shows another embodiment of the radiation fin of the present invention. In the drawing, the heat dissipation surface provided with the through holes is formed by vertically forming smaller convex portions 15 on both sides or one side of the through hole edge as shown in (a) or (b). Since the heat dissipation area can be expanded by the convex portion 15 at the edge of the through hole, the heating element can be efficiently cooled. Further, even in the structure in which air is blown from the side surfaces of the fins to cool the heating element, the air flow path can be arbitrarily adjusted by forming the convex portion 16 having an inclination as shown in (c), so that a large number of semiconductor elements are mounted. The substrate surface can be cooled efficiently. The size of the mold is adjusted so that the protrusions 15 and 16 can be formed arbitrarily when the through hole 11 is stamped out.

FIG. 6 shows another embodiment of the radiation fin of the present invention. The figure shows through holes and protrusions 17 and 18 formed on a flat plate.
It is the structure of the heat radiation fin which was molded simultaneously. As in (a) or (b), by leaving the surface to be the convex portion in advance during processing, the through hole with the convex portion can be easily formed.

FIG. 7 shows another embodiment using the heat radiation fin of the present invention. With an internal structure similar to the case shown in FIG.
A plurality of substrates stacked in the housing 71 are stacked with an inclination close to vertical. For example, the radiation fins 21 shown in FIG. 3 are attached to the semiconductor elements 50 to 52 mounted on the substrate surface having such an inclination, which are brought into contact with each other through a conductive member. The internal air flows upward while exchanging heat with the substrate 31 or the radiating fins 21, and the casing 71
The air is exhausted from the slit hole 66 on the upper surface. Radiating fins 2 used for substrates 31 stacked at an angle close to vertical
In No. 1, high temperature air staying on the lower surface of the package when there is no through hole 10 easily flows upward through the through hole, and cooling of the heating element surface can be promoted.

FIG. 8 shows another embodiment using the radiation fin of the present invention. With an internal structure similar to the case shown in FIG.
A plurality of semiconductor elements 50 to 52 are mounted on a substrate 30 stacked in a narrow space surrounded by the housing 70 and the keyboard 90. A fan 60 that blows air between the substrates is mounted on the side surface of the housing 70, and a slit hole 65 for exhaust is provided at the opposite housing end. Further, the radiation fin of the present invention shown in FIG. 2 to FIG. 4 is in contact with the semiconductor element 50 on the substrate laminated in the housing through the conductive member in the same manner as described above. When air is blown between the substrates by the fan 60 installed on the side surface of the housing 70, due to the effect of the through holes 10 on the radiating fin surface, air enters to the roots of the heating elements on the front side (fan side) and the rear side (exhaust hole side). The air also comes in, and the warmed air is exhausted through the slit hole 65 provided on the side surface of the opposite casing 70. Each semiconductor element 5
Since the air flows into the 0 side surface, heat can be transferred to the entire air including the fin surface, so that the heating element can be efficiently cooled.

FIG. 9 shows another embodiment using the radiation fin of the present invention. In FIG. 9A, the semiconductor element 50 that generates a large amount of heat is mounted on the substrate 30 in the housing 71, and the conductive member 55 is provided.
The semiconductor element 50 and the radiation fin of the present invention, for example, shown in FIG. When the heat radiation fin is brought into direct contact with such a thin semiconductor element, the space between the fin and the substrate becomes very narrow, and thus air flow is unlikely to occur. As shown in the figure, by widening the distance between the substrate 30 and the radiation fin 20 with the thick conductive member 55, the heat radiation performance of the fin itself is improved more than the heat transfer resistance to the fin surface by the conductive member, so that the cooling is efficiently performed. it can. As shown in FIG. 9 (b),
By using a radiation fin with one side cut out in advance,
Conduction resistance can be reduced. Further, in FIG. 9C, the lower portion is a metal casing surface 75 provided with a through hole, and the casing 75 and the substrate 3 are
The semiconductor element 50 on the surface 0 is brought into contact with the conductive member 55, for example, silicon rubber having high thermal conductivity. Since the metal casing 75 itself also has the same role as that of the heat radiation fins of the present invention, the structure is simpler than the fin arrangement inside, and the heat radiation area is large and the outside air is introduced into the housing. , High heat dissipation performance can be obtained.

Further, by coating the housing surfaces 71, 75 and the substrate surface 30 of FIG. 9 with a highly heat-radiative paint, for example, a black body paint, it is possible to cool efficiently.

FIG. 10 shows an embodiment of an electronic device using the radiation fin of the present invention. The figure shows a disk-side electronic device in which a power source 81, a hard disk 85, and a plurality of stacked substrates 30 are arranged in a housing 73. The substrate 30 is blown by the fan 60 through the duct 61 to cool the semiconductor elements on the substrate. For example, in FIG.
The heat radiation fin 21 of the present invention shown in FIG. Even if the fins are installed in the narrow space of the stacked substrates 30, efficient cooling can be performed without disturbing the flow of cooling air.

[0017]

According to the present invention, the heating element radiates heat to the heating element on the electronic substrate installed in the narrow space, and in both cases, the internal heating is performed regardless of whether or not the blowing means is used. It is possible to provide a radiating fin that can efficiently transfer the generated heat to the surroundings and exhaust it to the outside, and a cooling structure using the radiating fin.

[Brief description of drawings]

FIG. 1 is a perspective view of a first embodiment of the present invention.

FIG. 2 is a perspective view of a conventional radiation fin.

FIG. 3 is a perspective view of a second embodiment of the present invention.

FIG. 4 is a perspective view of a third embodiment of the present invention.

FIG. 5 is an explanatory diagram of a fourth embodiment of the present invention.

FIG. 6 is a perspective view of a fifth embodiment of the present invention.

FIG. 7 is a sectional view of a sixth embodiment of the present invention.

FIG. 8 is a sectional view of a seventh embodiment of the present invention.

FIG. 9 is a sectional view of an eighth embodiment of the present invention.

FIG. 10 is a perspective view of a ninth embodiment of the present invention.

[Explanation of symbols]

Reference numeral 10 ... Through hole, 20 ... Fin, 30 ... Substrate, 50 ... Semiconductor element, 60 ... Fan, 70 ... Housing, 80 ... Display, 90 ... Keyboard.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tadakatsu Nakajima 502 Jinritsu-cho, Tsuchiura-shi, Ibaraki Hiritsu Manufacturing Co., Ltd. Mechanical Research Laboratory (72) Inventor Kenji Onishi 1-horiyamashita, Hadano-shi, Kanagawa Hiritsu Manufacturing Co., Ltd. Office System Division (72) Inventor Hiroshi Tsuzaki 1 Horiyamashita, Hadano City, Kanagawa Prefecture Hitate Manufacturing Co., Ltd. Office System Division (72) Inventor Hitoshi Matsushima, 1 Horiyamashita, Hadano City, Kanagawa Prefecture Hirtitsu Manufacturing Co., Ltd. Office Systems Within the business unit

Claims (15)

[Claims] 1. An electronic board having a single or a plurality of layers stacked in a housing, which is a flat plate-shaped heat radiation fin that comes into contact with a semiconductor element mounted on the electronic board and has a plurality of through holes formed in the fin surface. Radiating fins for cooling electronic devices. 2. The heat dissipation fin for cooling electronic equipment according to claim 1, wherein the through hole formed in the fin surface of the plate-like heat dissipation fin is not on a surface to be brought into contact with the semiconductor element. 3. The radiating fin for cooling an electronic device according to claim 1, wherein an end surface of the radiating fin having the flat plate-shaped through hole has an edge of the through hole. 4. The radiating fin for cooling electronic equipment according to claim 1, wherein the fin surface is provided with the plurality of through holes and is cut out on one side of the fin surface. 5. A radiating fin for cooling electronic equipment, wherein said radiating fin surface having through-holes formed in said flat plate shape has an inclination as claimed in claim 1, 2, 3 or 4. 6. A radiating fin for cooling electronic equipment, wherein a convex portion is formed on one side or both sides of the through hole edge formed on the flat radiating fin surface of claim 1, 2, 3 or 4. 7. The electronic device according to claim 6, wherein the convex portion at the edge of the through hole of the flat plate-shaped heat dissipation fin surface is formed by bending a through hole member, and the convex portion and the through hole are integrally formed. Radiating fins for equipment cooling. 8. The radiating fin for cooling an electronic device according to claim 6, wherein the protrusion formed on the edge of the through hole has an inclination. 9. An electronic device in which a single or a plurality of stacked electronic boards and a fan are mounted in a housing, and the semiconductor elements on the electronic board are mounted on the semiconductor elements.
Alternatively, an electronic device using the heat radiation fin of 8. 10. An electronic device using the radiation fin of claim 1, 2, 3, 4, 5, 6, 7 or 8 on the electronic substrate, wherein a conductive member is provided between the radiation fin and the semiconductor element. An electronic device in which a gap greater than or equal to the height of the semiconductor element is provided between the electronic board on which the semiconductor element is mounted and the heat radiation fin. 11. An electronic device using the radiation fins according to claim 1 on an electronic substrate, wherein one or a plurality of the electronic substrate surfaces in a housing are vertically stacked. 12. An electronic device using the radiation fin according to any one of claims 1 to 10 on the electronic substrate, wherein a paint having a high emissivity is applied to a housing wall and a substrate, and a fin surface has a low emissivity. Electronic equipment coated with paint. 13. An electronic device in which a paint having a high emissivity is applied to the housing wall and the substrate of claim 14, wherein the applied paint is a black body paint. 14. An electronic board having a single or a plurality of layers stacked in a housing, wherein a semiconductor element mounted on the board is in contact with a housing surface having a plurality of through holes via a conductive member. Electronic equipment to do. 15. An electronic board having a single or a plurality of layers stacked in a housing, which is a flat plate-shaped heat radiation fin to be brought into contact with a semiconductor element mounted on the board, wherein an air flow passage is provided on the fin surface. Radiating fin for cooling electronic equipment.