JP2002305273A - Heat sink apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat sink apparatus that can reduce the discharge of radiation noise by decreasing antenna effects. SOLUTION: In the heat sink apparatus, plural heat dissipation fins 2 are erected on a base section 1, and the base section 1 is brought into contact with the heat sink surface of a high heat generating element for cooling the high heat generating element. In the heat dissipation fin 2, a high heat transfer dissipation fin 2A and a high resistance dissipation fin 2B are mixed. The high heat transfer radiation fin 2A is formed by a material, having proper heat transfer properties, and the high resistance dissipation fin 2B is formed by a metal material having high conductive resistance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat sink device for cooling a high heat generating element by contacting the heat sink surface of the high heat generating element.

[0002]

2. Description of the Related Art As a heat sink device for cooling a high heat generating element such as a CPU, there is known a heat sink device in which a plurality of heat radiation fins 2 are provided upright from a base portion in contact with a heat sink surface of the high heat generating element. Then, aluminum or the like having good thermal conductivity is used as the material so that heat generated from the high heat generating element can be quickly transmitted to the radiating fins and radiated by the radiating fins.

[0003]

On the other hand, a heat sink device for cooling a high heat generating element tends to be large-sized due to an increase in the amount of heat generated due to an increase in the operating clock of a CPU or the like recently. Since aluminum or the like is also a good conductor, it can function as an antenna with good electromagnetic noise generated by a CPU or the like.

In particular, since electromagnetic noise in a CPU or the like includes various frequency components, when the heat sink device has a length that resonates with a specific frequency component, the level of radiation noise also increases. , For example, EMI (El
(ectromagnetic Interference)

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a heat sink device capable of reducing emission of radiated noise by reducing an antenna effect.

[0006]

According to the present invention, the above object is achieved by arranging a plurality of radiating fins 2 on a base portion 1 and bringing the base portion 1 into contact with a heat sink surface of a high heat generating element. A heat sink device for cooling a high heat generating element, wherein the radiating fins 2 include a high heat conductive radiating fin 2A formed of a material having good heat conductivity and a high resistance radiating fin formed of a metal material having a high conductive resistance. This is achieved by providing a heat sink device in which the fins 2B are mixed.

The base 1 is preferably made of a material having good heat conductivity such as aluminum, and the radiation fins 2 erected on the base 1 are made of a material having good heat conductivity.
For example, the high heat conductive fins 2A made of aluminum, copper, etc., and the high heat conductive fins 2A made of iron, etc.
And the high-resistance radiating fins 2B formed of a metal material having a higher conductive resistance than the material for forming the fins 2B. The heat dissipating fins 2 may have a rectangular plate shape in a front view or a pin shape. Since the intensity of the radiated electromagnetic field is proportional to the current, the level of the radiated electromagnetic field at the high-resistance radiating fin 2B is reduced, and the antenna efficiency is reduced as a whole.

Further, since the heat radiation fins 2 include the high heat conductive heat radiation fins 2A, a reduction in cooling efficiency can be prevented as a whole.

Further, since the antenna efficiency increases as it approaches the outer peripheral edge of the heat sink device, a high-resistance radiating fin 2B having a low antenna efficiency is arranged at the outer peripheral edge of the heat sink device, and the high heat conductivity is provided inside the heat sink device. By disposing the heat radiation fins 2A and surrounding the high heat conductive heat radiation fins 2A with the high resistance heat radiation fins 2B, the antenna efficiency can be reduced as a whole.

Since the radiated electromagnetic field has a resonance frequency determined by the length of the antenna, it is possible to disperse the resonance frequency by making the length of the radiation fins 2 different. As a result, the radiation level at each resonance frequency can be reduced.

Further, since there is an inversely proportional relationship between the resonance frequency and the antenna length, the longer the antenna length, the lower the resonance frequency.
Is divided into a plurality of sections, so that the antenna length can be shortened. As a result, it is possible to shift the resonance frequency to a high frequency region that does not hinder other electronic devices or the like. In this case, if a material having excellent thermal conductivity is used as the insulating material interposed between the divided blocks, the overall heat radiation efficiency does not decrease.

Since the amount of electromagnetic wave radiation from the corner of the antenna is large, if a radio wave absorber is arranged at the corner of the base 1 or the radiation fin 2, the radiation level is reduced. be able to. The radio wave absorber can be formed by mixing, for example, ferrite or the like into an appropriate paint, and the radio wave absorber can be easily coated by applying it to a predetermined location.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, a heat sink device comprises a plurality of radiating fins 2,
.. formed upright. The base portion 1 is formed of a material having good heat conductivity such as aluminum, and a CP (not shown)
It comes into contact with the heat sink surface of a high heat generating element such as U and absorbs heat generated from the high heat generating element.

The radiation fins 2 are arranged on the base 1 in three rows. Each radiating fin 2 has a rectangular plate shape when viewed from the front, and the radiating fins 2 erected in the center row are
Is formed integrally with the heat dissipation fins 2A.
Further, the base portion 1 is surrounded by the heat transfer fins 2.
A high-resistance radiating fin 2B is disposed at an edge of the fin. The high-resistance heat-dissipating fins 2B are formed of a material that forms the high-heat-conducting heat-dissipating fins 2, for example, a material having lower conductivity than aluminum, copper, or the like, for example, iron. As shown in FIG. 1B, the high-resistance radiation fins 2B are fitted to the fitting grooves 1a formed in the base 1 and then joined to the base 1 by brazing or the like. In FIG. 1 (b), a joint portion by brazing or the like is denoted by reference numeral 5.

Therefore, in this embodiment, the heat generated from the high heat-generating element is immediately transferred to the base portion 1 having good heat conductivity, and most of the heat generated from the heat-generating device is formed integrally with the base portion 1. Although the fins 2A have an auxiliary heat conductivity lower than that of the high heat conductive radiating fins 2A, the fins 2A themselves are transferred to the high resistance heat radiating fins 2B having a predetermined heat conductivity to be radiated.

On the other hand, a part of the electromagnetic noise emitted from the high-heat-generating element has conductivity, but causes energy loss in the high-resistance radiating fin 2B having a high resistance value. The value drops. In addition, since the high-resistance heat-dissipating fins 2B having conductivity are arranged on both sides of the high-heat-conducting heat-dissipating fins 2A having a high antenna effect of electromagnetic noise, the row of the high-resistance heat-dissipating fins 2B functions as a shield. Therefore, the emission of electromagnetic noise to the outside is reduced.

FIG. 2 shows a modification of FIG. In this modified example, the high-resistance radiating fin 2B has a curved surface in which the edge on the windward side is concave at the center with respect to the plane 6 orthogonal to the blowing direction of the cooling air (the direction of arrow A in FIG. 2) or the center is convex. 7
The width dimension (W) is adjusted so as to conform to. In the example shown in the drawing, the symmetrical shape is formed so that the louver can be used regardless of which is on the windward side.

Therefore, in this modified example, FIG.
As shown in (b), even if the cooling air contains dust 8, it is hard to be caught between the radiation fins 2 and 2, so that the occurrence of clogging is reduced.

In the above description, the case where the heat conductive radiating fins 2A and the high resistance heat radiating fins 2B are arranged side by side in the same row has been described. It is also possible to arrange the high-resistance radiating fin 2B so as to completely surround the periphery of the heat-conducting radiating fin 2A. Further, the high heat conductive radiating fin 2A and the high resistance heat radiating fin 2B are formed to have the same height dimension. However, as shown in FIG. Alternatively, the hang portion 9 may be formed on the high-resistance heat-radiating fin 2B so as to cover the corner of the high-heat-conducting heat-radiating fin 2A, as shown in FIG. 3B.

Further, the radio wave absorbing layer 4 can be formed by applying a radio wave absorbing material to a corner portion of the high heat conductive radiating fin 2A with a coating agent.

FIG. 4 shows a second embodiment of the present invention.
In the description of the present embodiment, the same components as those in the above-described embodiment are denoted by the same reference numerals in the drawings, and description thereof will be omitted. In this embodiment, the heat sink device is formed by combining a plurality of heat sink blocks 10. Each heat sink block 10 is formed of a material having good heat conductivity such as aluminum, and a heat transfer insulating layer 3 having good heat conductivity and insulation performance is interposed at a joint portion of the heat sink block 10. .

As a result, the heat generated by the high heat generating element is absorbed by each heat sink block 10 and is radiated from the radiating fins 2. The heat sink blocks 10, 10
Since the space is insulated, each heat sink block 1
0 function as antennas. As a result, as compared with the case where the entire heat sink device is integrally formed, the antenna length is shortened, the resonance frequency is increased, and emission of electromagnetic noise in the regulated frequency band can be prevented.

In the embodiment shown in FIG. 4A, the case where the heat sink blocks 10 are arranged in parallel and joined by an insulator is shown. In addition, FIG.
As shown in (1), it is also possible to form a step that can be engaged with the base portion 1 of each heat sink block 10, and apply heat conductive grease or the like to the boundary of the step to form the heat transfer insulating layer 3.

In FIG. 4, the heat sink device is divided into two parts at the base part 1. However, it is also possible to divide the heat sink apparatus into two or more parts. In this case, since the resonance frequencies are dispersed, each peak value can be reduced.

Further, in FIG. 4, a division surface is set in the base portion 1, but it is also possible to divide the heat radiation fin 2.

[0026]

As is apparent from the above description, according to the present invention, the emission of radiation noise can be reduced by reducing the antenna effect.

[Brief description of the drawings]

1A and 1B are diagrams showing the present invention, in which FIG. 1A is a plan view, and FIG. 1B is a cross-sectional view taken along line 1B-1B of FIG.

FIGS. 2A and 2B are views showing a modification of FIG. 1, wherein FIG.
(B) is an enlarged view of the 2B part of (a).

FIGS. 3A and 3B are views showing another modification of FIG. 1, wherein FIG. 3A is a side view and FIG. 3B is a side view showing still another modification.

FIG. 4 is a diagram showing a second embodiment of the present invention, in which (a)
FIG. 7 is a perspective view, and a perspective view showing a modified example of FIGS.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base part 2 Heat radiation fin 2A High heat conductive heat radiation fin 2B High resistance heat radiation fin 3 Heat transfer insulating layer 4 Radio wave absorption layer

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akira Sekino 98 Uno-ki-nu, Unoki-cho, Hebei-gun, Ishikawa Prefecture 2 PFU Co., Ltd. No. 2 F-term Co., Ltd. F-term (reference) 5E322 AA01 FA04 5F036 AA01 BB01 BD01 BD11

Claims (5)

[Claims] 1. A heat sink device comprising a plurality of radiating fins erected on a base portion, wherein the radiating fins are cooled by contacting the base portion with a heat sink surface of the high heat generating element. Is a heat sink device in which high heat conductive radiating fins formed of a material having good heat conductivity and high resistance radiating fins formed of a metal material having high conductive resistance are mixed. 2. The heat sink device according to claim 1, wherein said high-resistance heat-radiating fin is arranged so as to surround said high-heat-conducting heat-radiating fin. 3. The heat sink device according to claim 1, wherein the heat radiation fins are formed in a rectangular plate shape, and a plurality of types of heat radiation fins having different lengths are mixed. 4. A heat sink device comprising a plurality of radiating fins erected on a base portion to cool the high heat generating element by bringing the base portion into contact with a heat sink surface of the high heat generating element. A heat sink device in which a base portion is divided into a plurality of sections via a heat transfer insulating layer made of an insulating material. 5. A heat sink device comprising a plurality of radiating fins erected on a base portion to cool the high heat generating element by contacting the base portion with a heat sink surface of the high heat generating element. Alternatively, a heat sink device in which a radio wave absorbing layer made of a radio wave absorber is formed at a corner of the radiation fin.