JP4155167B2 - Thermal conductor - Google Patents

Description

The present invention relates to heat generated from a heating element in thermal conductor for conducting.

2. Description of the Related Art In recent years, the amount of generated heat has been increasing due to the increase in operating frequency of CPU (Central Processing Unit), MPU (Micro Processing Unit), etc. At present, a method of bringing a heat conductive material such as a heat spreader or a heat radiating fin into contact with the heat generating element is generally used for such a heat dissipating process of the heat generating element. As such heat-conducting materials such as heat radiating fins, aluminum and copper having a thermal conductivity of 220 [W / (m · K)] and 360 [W / (m · K)], respectively, are mainly used. Yes. In addition, as a heat conductive material, there is a material in which a highly heat conductive powder is covered with an electrically insulating film, and for example, a metal powder, a carbon powder, or the like is used as the powder (for example, see Patent Document 1).
JP-A-8-183875 (paragraphs [0004] and [0005])

  However, since the heat generation amount of the heating element is steadily increasing, even if a metal radiating fin or the like is used, it is insufficient in its capacity and it is necessary to radiate heat more efficiently. Although it is conceivable to increase the area and volume in order to further improve the heat dissipation efficiency, there is a problem that the weight becomes heavy if a metal member is used.

In view of the circumstances as described above, an object of the present invention is to provide a heat conductor that can efficiently conduct the heat of the heating element.

Another object of the present invention is to provide a heat conductor that can be reduced in weight.

To achieve the above object, in the thermal conductor according to the present invention, for cooling a heating element, it is mounted a cover for air inlet for flowing the external air is provided, the outside via the air inlet by a fan A heat conductor that conducts heat generated from the heating element to a heat sink by using air supplied from the heating element, and is provided to conduct heat generated from the heating element in at least a first direction. The first region is provided adjacent to the first region, and is provided so as to conduct heat transferred from the first region in at least a second direction different from the first direction. a thermal diffusion member that includes a second region, a case portion in which the cover is mounted, the side on which the heat diffusion portion is provided provided on the opposite side, the cover is attached to the casing section waste which is formed by A mouth, the heat sink is attached, the fan by an exhaust port for discharging the air supplied through the air inlet from the outside, the heat is diffused by the heat diffusion portion is conducted, the fan And a case portion for housing the container.

  In the present invention, to conduct heat in the first direction specifically means that the heat conductivity in the first direction is the highest in the first region. Similarly, “conducting heat in the second direction” means that the thermal conductivity in the second direction is the highest in the second region. Examples of the heating element include an electronic component such as an IC chip and a resistor. However, the heating element is not limited thereto, and any heating element may be used. The same applies hereinafter.

  In the present invention, for example, the heat of the heating element can be efficiently conducted by optimizing the first and second directions in accordance with the shape of the heat conductor. Further, for example, the first and second directions can be optimized in accordance with the position where the heating element is disposed with respect to the heat conductor, the amount of heat of the heating element, the size of the heating element, and the like. The heat of the heating element can be conducted well.

According to an embodiment of the present invention, the first direction and the second direction and a straight interlinking. Thereby, the heat of a heat generating body can be conducted to the inside of a heat conductor, and can be conducted in the direction along the surface. That is, heat can be efficiently conducted in three dimensions. In particular, if the heat conductor is plate-shaped, for example, heat conduction can be performed in the thickness direction in the first region, and heat conduction can be performed in the second direction along the surface of the plate.

  According to an aspect of the present invention, at least one of the first region and the second region includes a third region that conducts in a third direction different from the first and second directions. Including. In the present invention, for example, if the positions of the first, second, and third regions and the first, second, and third directions are optimized, the heat can be more efficiently conducted.

  By the way, for example, when molding a heat conductor, a material such as a resin flows out so as to spread in the cavity through an injection path of the mold. By utilizing this phenomenon, it is possible to provide a direction of high heat conduction that spreads from the outflow site of the injection path in the first or second region. That is, in the present invention, it is not necessary to form the first region so as to positively conduct heat in the first direction and the third direction, and at least according to the first direction and the third direction. The directionality of heat conduction is naturally formed during mold forming. Similarly, it is not necessary to form the second region so as to actively conduct heat in the second direction and the third direction, and heat conduction in at least the second direction and the third direction is not required. Directionality is formed naturally during mold forming.

  According to one aspect of the present invention, at least one of the first region and the second region includes a metal, a carbon material, or a graphite material. By including a material having high heat conductivity in this way, heat can be efficiently conducted. Copper or aluminum can be used as the metal. Further, by using a carbon material, particularly a graphite material, it is possible to conduct heat with a higher thermal conductivity than metal, and it is possible to achieve weight reduction.

  According to one embodiment of the present invention, the first material constituting the first region is different from the second material constituting the second region. In the present invention, optimization to achieve high thermal conductivity can be achieved by appropriately selecting the first and second materials.

  In the present invention, for example, by optimizing the first and second directions according to the shape of the heat conductor, the heat of the heating element can be efficiently conducted, and the heat radiating portion can radiate and cool the heat. it can. For example, the first and second directions can be optimized in accordance with the position where the heating element is disposed with respect to the heat conductor, the amount of heat of the heating element, the size of the heating element, or the like. A fan, a heat pipe, a heat radiating fin, or the like can be used as the heat radiating portion.

  An electronic device according to the present invention is provided adjacent to the heating element, a first region provided to conduct heat generated from the heating element in at least a first direction, and the first region. A second region provided to conduct heat transmitted from the first region in at least a second direction different from the first direction, and dissipate heat conducted in the second region. And a heat dissipating part. Examples of the electronic device include a computer, a PDA (Personal Digital Assistance), and an electric appliance. The same applies hereinafter.

  In the present invention, for example, the first and second regions can be formed by optimizing the first and second directions according to the shape of the heat conductor. Thereby, the heat conduction of the shape | molded heat conductor can be improved. Further, by utilizing the phenomenon that the first or second material flows out into the cavity through the injection path of the mold, it spreads from the outflow portion of the injection path in the first or second region. It can be made to have a high directivity of heat conduction. Thereby, manufacture of a heat conductor becomes easy.

  As described above, according to the present invention, the heat of the heating element can be efficiently conducted, and the weight can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view showing a cooling device using a heat conductor according to the present embodiment. FIG. 2 is a cross-sectional view of the cooling device 10.

  The cooling device 10 has a heat conductor 12. The heat conductor 12 is composed of, for example, a case portion 12a that houses the fan 17 and a heat diffusion portion 12b. The heat diffusing unit 12b is provided with a heat receiving unit 12c as a first region to which a heat generating unit 18 such as a CPU is bonded and receives heat generated from the heat generating unit. The region other than the heat receiving portion 12c in the heat conductor 12 is a second region. A cover 16 provided with an air inlet 16a is attached to the case portion 12a, and the fan 17 is covered by the cover 16. The fan 17 causes the outside air to flow in from the intake port 16a and the air that flows in from the exhaust port 12d to flow out as the blade member 21 is rotated by the motor unit 22. The motor unit 22 includes a bearing, a coil, a stator, a rotor, and the like (not shown). A heat sink (radiating fin) 11 is attached to the exhaust port 12d.

  The heat receiving part 12c of the heat conductor 12 is provided so as to conduct heat most efficiently in the thickness direction (vertical direction) of the heat diffusion part 12b. On the other hand, in the part other than the heat receiving part 12c in the heat conductor 12, that is, the part around the heat receiving part 12c and the case part 12a, heat is most efficiently performed in the direction along the surface of the heat conductor 12 (lateral direction). It is provided to conduct.

  As a material of the heat conductor 12, for example, resin or fiber can be used. Specifically, carbon resin or fiber can be used. Moreover, even if it is resin other than carbon, the resin, the metal, the carbon material, the carbon nanotube, or the graphite material may be contained. Copper or aluminum can be used as the metal. As described above, by including a material having high heat conductivity, heat can be efficiently conducted. Moreover, weight reduction can also be achieved by using a carbon-type material. Moreover, when using a metal, weight reduction can be achieved by mixing a metal powder with resin.

  In particular, it is preferable to use a graphite material having a single crystal structure with strong orientation. By using the graphite material, the thermal conductivity can be set to 600 to 800 [W / (m · K)], and the thermal conductivity of copper is about 1 to about 300 to 400 [W / (m · K)]. It can be 5 to 2 times, and weight reduction can be achieved.

  These materials may be included in the entire heat conductor 12 or may be included locally or partially in the heat conductor 12. For example, only the heat receiving part 12c can be configured to include a metal, a carbon material, a carbon nanotube, or a graphite material. Or it can be set as the structure by which the said material is contained only in parts other than the heat receiving part 12c, for example, the case part 12a. Alternatively, different materials may be included in the heat receiving part 12c and the parts other than the heat receiving part 12c.

  The operation of the cooling device 10 configured as described above will be described.

  The heat generated from the heating element 18 is absorbed from the heat receiving portion 12c. In the heat receiving part 12c, it conducts most efficiently in the vertical direction. Then, heat is most efficiently conducted in the lateral direction around the heat receiving portion 12c and the case portion 12a in the heat diffusing portion 12b. Thereby, heat can be efficiently conducted in three dimensions. The heat conducted to the case portion 12a is transmitted to the heat sink 11 and radiated to the outside air.

  On the other hand, as the blade member 21 of the fan 17 rotates, external air flows into the case portion 12a from the intake port 16a. The inflowing air flows out from the exhaust port 12d, the air is blown onto the heat sink, and the heat of the heat sink 11 is released into the air. Further, the case portion 12a is cooled by the air that has flowed into the case portion 12a.

  With reference to FIG.3 and FIG.4, the usage example of the cooling device 10 which concerns on this Embodiment is demonstrated.

  As shown in FIG. 3, the CPU 19 mounted on the circuit board 25 is bonded to the heat receiving portion 12c with, for example, a high heat conductive adhesive 26 or the like. Thereby, CPU19 can be cooled efficiently.

  FIG. 4 is a cross-sectional view showing a part of a laptop PC (Personal Computer) in which, for example, the cooling device 10 is built. The cooling device 10 is disposed in the housing 31 of the PC 30. A portion indicated by reference numeral 32 is a keyboard. The CPU 19 is bonded to the heat receiving portion 12 c of the cooling device 10 with an adhesive 26. The CPU 19 is mounted on the circuit board 25. As described above, the cooling device 10 is mounted on the PC 30, and the gas generated by the fan is discharged from the opening 31 a provided in the housing 31, so that the cooling process can be efficiently performed.

The shape of the heat receiving portion 12c is substantially cylindrical (disc shape) as shown in FIGS. 1 and 2, but is not limited thereto, and may be any shape. Moreover, in the said embodiment, although the area | region where the direction of heat conduction differs was made into two area | regions of the heat-receiving part 12c and other parts, of course, three or more may be sufficient. Further, such is not limited position or size definitive thermal conductor 12 in each region.

  Moreover, in this Embodiment, according to the shape of the heat conductor 12, for example, by optimizing the direction of heat conduction in the heat receiving part 12c and other parts, the heat of the heating element can be efficiently conducted. it can. Further, for example, the direction of heat conduction can be optimized according to the position where the heating element 18 or the like is disposed with respect to the heat conductor 12, the amount of heat of the heating element, the size of the heating element, or the like. The heat of the heating element can be conducted well.

  Next, the manufacturing method of the heat conductor which concerns on one embodiment of this invention is demonstrated. FIG. 5 is a cross-sectional view showing a part of the cavity portion of the mold.

The mold 40 is provided with at least two gates 40b and 40c and a cavity 40a. Since the gate 40b and 40c are provided so as to be substantially Cartesian, material is adapted to be injected into the cavity 40a in a direction substantially Cartesian. By injecting a resin material such as carbon as a heat conductor material from both gates 40b and 40c of the mold 40, the heat receiving portion 12c in the heat diffusion portion 12b of the heat conductor 12 described in the above embodiment and the others Are formed. That is, the heat receiving portion 12c is formed by the material injected from the gate 40b, and the heat diffusion portion other than the heat receiving portion 12c is formed by the material injected from the gate 40c. Thus, since the injection direction by the gate 40b and 40c is almost Cartesian, material flows in a direction generally Cartesian, respectively in the cavity 40a. A direction in which the thermal conductivity is highest is formed along this flow, and the thermal conductor 12 described in the above embodiment is formed.

  Further, in the present embodiment, when the heat conductor 12 is molded, the resin material flows out so as to spread into the cavity through the injection path of the mold. By utilizing this phenomenon, for example, the heat receiving portion 12c can have a high heat conduction direction that spreads from the gate 40b to the cavity 40a. That is, in the present embodiment, instead of conducting heat in the same direction in the entire region of the heat receiving portion 12c, the third region indicated by a broken line, for example, is used by utilizing a phenomenon that the material spreads into the cavity 40a. The direction of high heat conduction can be made different between the region A and the region B. The same can be said for the thermal diffusion portion 12b other than the heat receiving portion formed by flowing into the cavity 40a from the gate 40c. Thereby, for example, the heat conducted in the heat receiving part 12c is most efficiently transmitted to the part other than the heat receiving part 12c in the oblique direction in the region B, so that the thermal efficiency of the heat conductor 12 can be further improved.

  In addition, since it is not necessary to positively form the regions A and B in the heat receiving portion 12c, the manufacture of the heat conductor 12 is facilitated.

  In the present embodiment, the material injected from the gates 40b and 40c may be different. That is, two-color molding can also be performed. Thereby, the optimization for achieving high thermal conductivity can be achieved by appropriately selecting the material.

It is a perspective view which shows the cooling device using the heat conductor which concerns on this Embodiment. It is sectional drawing of the cooling device shown in FIG. It is a perspective view which shows the usage example of the cooling device which concerns on this Embodiment. It is sectional drawing which shows a part of PC in which the cooling device which concerns on this Embodiment was incorporated. It is sectional drawing which shows a part of metal mold | die for manufacturing a heat conductor.

Explanation of symbols

A, B ... area 10 ... cooling device 12 ... heat conductor 12a ... case part 12b ... heat diffusion part 12c ... heat receiving part 17 ... fan 18, 19 ... heating element 40 ... mold

Claims (5)

In order to cool the heating element, a cover provided with an intake port for allowing external air to flow in is installed , and heat generated from the heating element using air supplied from the outside through the intake port by a fan is used. A heat conductor that conducts heat to the heat sink,
A first region provided so as to conduct heat generated from the heating element in at least a first direction; and heat transferred from the first region provided adjacent to the first region. A thermal diffusion unit including at least a second region that is provided to conduct in a second direction different from the first direction;
A case part to which the cover is attached, provided on the side opposite to the side on which the heat diffusion part is provided, and an exhaust port formed by attaching the cover to the case part ; the heat sink is attached, the fan by an exhaust port for discharging the air supplied through the air inlet from the outside, the heat is diffused by the heat diffusion portion is conductive, the case portion for accommodating the fan And a heat conductor characterized by comprising: The heat conductor according to claim 1 ,
Thermal conductor to the first direction and the second direction, wherein the straight interlinked. The heat conductor according to claim 1 ,
At least one of the first region and the second region includes a third region that conducts in a third direction different from the first and second directions. The heat conductor according to claim 1 ,
At least one of the first region and the second region contains a metal, a carbon material, or a graphite material. The heat conductor according to claim 1 ,
A heat conductor, wherein the first material constituting the first region is different from the second material constituting the second region.

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