JP3256348B2 - heatsink - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat sink used for an LSI having a high heat generation density, such as a high-speed drive microcomputer, a semiconductor device such as a medium-capacity thyristor or a power transistor, and more particularly to an air-cooled type for diffusing and cooling the heat, thereby reducing the size. Related to a heat sink required to be manufactured.

[0002]

2. Description of the Related Art QFP (Quad Flat Pack)
9) and FIG. 10 are a perspective view and a side view showing an example in which a conventional heat sink is attached to an LSI of a ceramic package in FIG. 9 and FIG. 10. A heat sink 90 is made of a material having high thermal conductivity such as aluminum or copper. It is cut so as to have a fin part 92 around the heat conduction support part 91,
A QFP-type LSI 93 in which the center of the support portion 91 is a heat source
The heat generated by the LSI 93 is dissipated by the fins 92.

[0003]

In the heat sink 90 having the above-described structure, the fins 92 of the heat sink 90 are increased by increasing the diameter dl of the fin portion 92 or increasing the number of fins as the heat generation amount of the LSI 93 increases. If the surface area of the portion 92 is not increased, a sufficient heat radiation effect cannot be obtained. However, if d1 of the heat sink 90 is larger than the outer shape of the LSI 93 or the height H is too high, such a large heat sink 90 can be used as an electronic device. If it is arranged in a limited narrow space such as equipment, there is a problem that convection of air is hindered and the cooling capacity is significantly reduced.

[0004] Even if the heat sink 90 is allowed to have a large size, simply increasing the diameter dl of the fin portion 92 or increasing the number of fins does not increase the heat source (LS).
Since the heat resistance of the material of the heat sink 90 increases due to the distance from the current source I93), it is necessary to increase the thickness t1 of the fins and increase the diameter d2 of the heat conducting support portion 91. As a countermeasure against the increase in the size of the heat sink, the size of the heat sink is often increased, and at the same time, the size of the motor such as forced convection is often increased.

In the processing of the heat sink 90, the ratio of the diameter d2 of the heat-conducting support portion 91 to the diameter d1 of the fin portion 92 is suitable for convection in the fin interval t2 from the relationship between the heat sink material and the strength and cutting accuracy of the cutting tool. Since there is a limit to the cutting process while maintaining a constant interval, there is also a limit to a partial miniaturization such as reducing the fin thickness t1 of the heat sink 90.

The present invention has been made in view of the above problems, and has as its object to provide a small and lightweight heat sink structure for improving heat radiation performance, and to solve the above-mentioned problems.

[0007]

According to the present invention, there is provided a heat sink having a structure in which a heat receiving plate and at least one radiating fin are overlapped with each other.
The interval between the plate and the fin is
Ridges, each ridge is brazed
Heat sink , the center of the radiation fin
A vent is provided near the portion, and a vibrator or vibrator is disposed in the vent. The vibrator may be constituted by an intake valve driven by a coil disposed in a heat sink, and a temperature sensor may be provided at a drive signal input portion of the vibrator or the vibrator.

[0008]

According to the above construction, the air forcedly taken in by the vibrator or the diaphragm provided in some of the ventilation holes of the radiating fins is formed as a convection in the radiating plate and a plurality of radiating fins stacked on each other. In the heat sink, convection is generated in the space between each fin or the heat receiving plate, and the hot air generated in these portions can be transported out of the heat sink. It is possible to obtain a small and lightweight heat sink having an excellent heat radiation effect.

In the present invention, as described above, since the convection is generated by the vibrator or the diaphragm without using a motor and a fan, the apparatus itself can be made extremely simple and small, and the entire electronic apparatus on which the present heat sink is mounted can be used. The degree of freedom in design also increases.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 2 is a top view of a first embodiment of the present invention, and FIG. 1 is a side view of FIG. In FIGS. 1 and 2, a heat sink 10 is attached to a heating element with one surface of a heat receiving plate 11 made of a material having excellent thermal conductivity, such as aluminum or copper, processed into a flat quadrilateral and used as a heat receiving surface. Is provided with a coil portion 68 extending vertically from the heat receiving plate 11, and a plurality of radiating fins 12 for effectively releasing the heat of the heat receiving plate 11 are provided on the other surface side.

The area of the flat surface of the plurality of radiating fins 12 is substantially equal to that of the heat receiving plate 11. In this embodiment, four radiating fins 12 are stacked, and 12a is provided and joined to the opposing surface by brazing, etc., and forms a space between each radiating fin 12 to form an air convection passage and at the same time each radiating fin
A heat conduction path is formed between 12 and the heat receiving plate 11. A ventilation hole 50 is provided at the center of each of the heat radiation fins 12, and the coil portion 68 is formed in a space defined by the ventilation hole 50.
Is arranged.

In this embodiment, the heat receiving plate 11
The uppermost radiation fin 12 of the four radiation fins 12 arranged above
A vibration device 60 described below is attached to the ventilation hole 50.
FIG. 3 is an enlarged view of the vibration device 60. In the vibration device 60 shown in FIG. 3, a vibration member 62 made of an elastic material such as rubber is attached and fixed to both ends of the outer periphery of the ventilation hole 50, and an intake valve 64 is attached to one of the vibration members 62a. A magnetic body 66 such as a ferrite piece is attached to the lower surface of the vibrating member 62. Air is taken in. The vibrating device 60 may have any structure other than the above-described structure as long as it can take in the atmosphere into the radiating fins 12. For example, as shown in FIG.
May be integrated and attached to the vent hole 50.

As a second embodiment of the present invention, a side cross-sectional view of a heat sink in which a vibrator 70 is provided in a ventilation hole 50 instead of the vibrating device 60 of the first embodiment is shown in FIG. The present embodiment has a structure in which the coil unit 68 is omitted by replacing the vibrating device 60 of the first embodiment with a vibrator 70 composed of a ceramic piezoelectric element or the like. The structure of the fins 12 and the like are the same as those described in the first embodiment, and thus description thereof is omitted.

In the first and second embodiments, as shown in FIGS. 1 and 5, the vibrating device 60 or the vibrator 70 has a structure in which the vibrating surface is mounted in parallel to the heat receiving plate. It may be vertical as shown in FIG.
This mounting direction may be arbitrarily changed.

In the first and second embodiments, the vibrating device 60 and the vibrator 70 are driven by the driving circuits shown in FIGS. 7 and 8, respectively. If a temperature sensor is added to the unit 30, the driving and stopping of the vibrating device 60 and the vibrator 70 can be controlled according to the heat generated by the heat sink (heating element).

The heat sink 10 in each of the above embodiments
And the number of shapes of the radiation fins 12, the fin projections 12a,
The positions, shapes, numbers, and the like of the ventilation holes 50, the vibrating device 60, the vibrator 70, and the like are merely examples, and may be arbitrarily changed.

[0017]

According to the heat sink having the above-described structure, even if the electronic device has a small external shape, there is no space for disposing a fan or the like for generating convection, and forced air cooling is performed only in a space equivalent to the conventional heat sink. And a heat sink having an excellent cooling capacity can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional side view of a heat sink according to a first embodiment of the present invention.

FIG. 2 is a top view of the heat sink according to the first embodiment of the present invention.

FIG. 3 is an enlarged view of the vibration device of the present invention.

FIG. 4 is an enlarged view of the vibration device of the present invention.

FIG. 5 is a sectional side view of a heat sink according to a second embodiment of the present invention.

FIG. 6 is a top view of a heat sink in which a vibration device is arranged perpendicular to a heat receiving plate.

FIG. 7 is a circuit diagram illustrating an example of a vibration device driving circuit.

FIG. 8 is a circuit diagram showing an example of a vibrator driving circuit.

FIG. 9 is a perspective view of a conventional heat sink.

FIG. 10 is a side view of a conventional heat sink.

[Explanation of symbols]

 In the drawings, the same reference numerals indicate the same or corresponding parts. DESCRIPTION OF SYMBOLS 10 Heat sink 11 Heat receiving plate 12 Heat radiating fin 12a Fin projection 50 Vent hole 60 Vibration device 62 Vibration material 64 Intake valve 66 Ferrite piece 68 Coil part 70 Vibrator

Claims (3)

(57) [Claims] 1. A heat sink having a structure in which a heat receiving plate and at least one radiating fin are overlapped with each other.
The interval between the rate and the fin is
Ridges, each ridge is brazed
A heat sink , wherein a central portion of the radiation fins
A heat sink provided with a ventilation hole in the vicinity , and a vibrator or a vibrator arranged in the ventilation hole. 2. A heat sink, wherein the vibration device according to claim 1 comprises an intake valve driven by a coil disposed in the heat sink. 3. A heat sink provided with a temperature sensor at a drive signal input section of the vibration device or the vibrator according to claim 1.