JP4969979B2 - heatsink - Google Patents

Description

  The present invention relates to a heat sink including a plurality of heat pipes arranged horizontally in parallel with a predetermined gap, and more particularly, to a heat sink capable of maintaining high heat dissipation efficiency even when the heat pipe is inclined.

  A heat generation amount and a heat generation density of heat generating components such as a CPU and an element disposed in a thin casing increase, and a thin high-performance heat sink that efficiently dissipates them is demanded. In personal computers as well, CPUs, graphic chips (GPU or VGA), chipsets and other elements that require active heat dissipation have increased. Furthermore, it is desired to radiate and cool a plurality of heating elements with one heat sink. Conventionally, heat sinks made of extruded aluminum material, which are inexpensive to manufacture, have been used. The heat sink made of extruded material is easy to manufacture because the base plate and heat radiating fins are integrally formed, but the pitch is limited due to manufacturing limitations, and it is technically difficult to form fins with a fine pitch. Met. However, it is difficult to cope with an increase in the amount of heat generated only by the combination of the base plate and the heat radiating fins, and furthermore, a heat sink combined with a heat pipe has been used. By using a heat pipe in this way, fin efficiency is improved and a reduction in size and weight is expected.

A space serving as a flow path for the working fluid is provided inside the heat pipe, and heat is moved by the phase change or movement of the working fluid accommodated in the space such as evaporation and condensation. That is, on the heat absorption side of the heat pipe, the working fluid evaporates due to the heat generated by the parts to be cooled that are conducted through the material of the container constituting the heat pipe, and the vapor moves to the heat radiation side of the heat pipe. To do. On the heat radiating side, the working fluid vapor is cooled and returned to the liquid phase again. The working fluid that has returned to the liquid phase in this way moves (refluxs) again to the heat absorption side. Heat is transferred by such phase transformation and movement of the working fluid.
JP-A-11-351769

  The heat generation amount and heat generation density of heat generating parts such as CPU and elements arranged in a thin casing increase, and in order to efficiently dissipate these, heat is moved to a predetermined position by a heat pipe, It is not sufficient to cool by the heat radiation fins, and a further heat radiation effect is expected. Furthermore, when the plurality of heat-generating components are cooled at the same time, if they are tilted during use, so-called dryout occurs, and heat dissipation of the heat-generating components may be insufficient.

  Accordingly, the object of the present invention is to provide an extremely thin, compact, excellent heat radiation efficiency, and to directly cool the outer peripheral surface of the heat pipe without causing so-called dryout even when used in an inclined state. It is to provide a heat sink that can be used.

  The inventor conducted extensive research to solve the conventional problems. As a result, a plurality of heat pipes forming a heat sink are arranged in parallel with a predetermined gap therebetween, the center portion of the heat pipe is curved corresponding to the arranged heating element, and the heat radiation fins are thermally provided at both ends. It has been found that the cooling efficiency is further improved when the cold air sucked from the center portion directly cools the outer peripheral surface of the heat pipe.

  Furthermore, even when at least one of the plurality of heat pipes described above is in a state where the heat pipe portion is inclined and one radiating fin portion is located below the heat absorbing member, the heat radiating fin portion located below is the most. It has been found that so-called dry-out is unlikely to occur when the working fluid is immersed in the vicinity of the adjacent heat absorbing member. The present invention has been made based on the research results described above.

According to a first aspect of the heat sink of the present invention, a plurality of heat pipes arranged substantially in parallel and substantially horizontally at a predetermined interval are thermally connected to a plurality of heat absorbing members in the vicinity of the center portion of the heat pipe. A heat pipe portion in which each end portion of each heat pipe extends in the opposite direction from the connection portion of the heat absorbing member, and
A heat dissipating fin portion that is thermally connected to each of both ends of the heat pipe portion extending in the opposite direction of the heat absorbing member, and is disposed in the vicinity of the side surface of the housing that covers the heat pipe portion and the heat absorbing member ;
With
The heat pipe portion cools an outer peripheral surface of the heat pipe through the predetermined interval of the plurality of heat pipes in which air sucked in a substantially vertical direction is arranged in parallel at a center portion, and further, the radiating fin portion The central portion is curved so as to pass through, and is disposed so as to recede in the inner direction of the housing on the same plane from the both end portions, and the predetermined interval is provided over almost the entire length of the central portion. It is characterized by.

The second embodiment of a heat sink of the present invention, among the heat absorbing member connected to thermal to heat-generating components to be cooled, at least in part, heat sink holding member is attached for holding said predetermined distance It is.

State of the third embodiment of a heat sink, at least one of the plurality of the heat pipes, wherein said heat dissipating fin portion partially inclined in one of the heat pipe portion is positioned below the heat absorbing member to the present invention Even if it exists, it is a heat sink which has the quantity of hydraulic fluid immersed in the heat absorption member vicinity closest to the said radiation fin part located below.

According to the heat sink of the present invention, it is possible to efficiently cool a plurality of parts to be cooled that are disposed in a thin casing having a small thickness and a high heat generation density.
That is, at least one of the plurality of heat pipes is closest to the radiating fin portion positioned below even when the heat pipe portion is inclined and one radiating fin portion is positioned below the heat absorbing member. Since the working fluid is immersed in the vicinity of the heat absorbing member, so-called dry out does not occur, and high heat radiation efficiency can be maintained even in an inclined state.

Furthermore, since the plurality of heat pipes are arranged in parallel with a predetermined gap at the center, cooling air can pass between the heat pipes, and the heat pipes themselves are also cooled, so that the cooling efficiency is improved. improves.
Furthermore, the central part of the heat pipe is curved in correspondence with the heating element arranged, and the heat radiating fins are thermally connected to both ends so that the cold air sucked from the central part is directly on the outer peripheral surface of the heat pipe, Cooling efficiency is further improved because the heating element is cooled.

The heat sink of the present invention will be described with reference to the drawings.
One aspect of the heat sink of the present invention includes a heat pipe portion in which a plurality of heat pipes arranged substantially horizontally are arranged substantially in parallel, a heat dissipating fin portion attached to both ends of the heat pipe portion, and a heat The heat sink includes a plurality of heat absorbing members attached to the center of the pipe portion. At least one of the plurality of heat pipes has a heat-absorbing member that is closest to the heat-dissipating fin portion located below, even if the heat-pipe portion is inclined and one heat-radiating fin portion is located below the heat-absorbing member. It is a heat sink having an amount of working fluid immersed in the vicinity. A plurality of heat pipes are arranged substantially in parallel with a predetermined gap at the center.

  FIG. 1 is a plan view seen from the front side for explaining one embodiment of the heat sink of the present invention. As shown in FIG. 1A, two heat pipes 2-1 and 2-2 are arranged in parallel with a predetermined gap on the same plane (for example, horizontal). The predetermined interval described above is provided over almost the entire length of the central portion. The heat pipe may be a round heat pipe or a flat heat pipe. By using a flat heat pipe, the width of the heat pipe can be made extremely thin. The size of the heat pipe is not necessarily the same. For example, a heat pipe having a small diameter and a heat pipe having a large diameter may be combined.

  In this embodiment, the heat pipes 2-1 and 2-2 are so-called flat heat pipes having a flat cross section. Radiation fins 3-1 and 3-2 are thermally connected to both end portions of the heat pipes 2-1 and 2-2. The heat radiation fins 3-1 and 3-2 are rectangular and have, for example, an upper surface, a bottom surface, and side surfaces that are parallel to each other, and the flat upper surface is one flat surface (for example, the back side) of both ends of the flat heat pipe. Is thermally connected so that the thermal resistance is reduced. It is preferable that both ends of the heat pipe are thermally connected over the entire length along the long axis direction of the heat radiating fin. The cooling air passes through the heat radiating fins along the direction perpendicular to the heat pipe.

  The flat heat pipe is curved so that, for example, the central portion is retracted in accordance with the arrangement of the heating elements (not shown) and the positions of the radiation fins. In the aspect shown in FIG. 1, it arrange | positions so that one edge part of a radiation fin may touch the opening part of the side wall of a housing | casing, and the air in a housing | casing is discharge | released out of a housing | casing through a radiation fin. Thus, both ends of the heat pipe are arranged along the side wall of the housing. With respect to both ends of the heat pipe, the central portion of the heat pipe is retreated from the side wall of the housing and is curved toward the inside of the housing.

  That is, as described above, the central portion of the heat pipe is curved and retracted so that it can be thermally connected to a plurality of heating elements, and one surface (that is, the back surface) is arranged at a predetermined position. The plurality of heat generators and the heat absorbing members 4-1, 4-2, 4-3 are thermally connected.

  FIG.1 (b) is a figure explaining an endothermic member. One surface of the heat absorbing member 4 is thermally connected to the heating element. The other surface of the heat absorbing member 4 is thermally connected to the heat pipe. A holding member 6 for holding a predetermined gap between the heat pipes arranged in parallel is attached to a substantially central portion of the heat absorbing member 4. The holding member 6 may be formed integrally with the heat absorbing member 4, or may be formed by preparing separate members and joining them.

  The holding member may be provided on at least one of a plurality of heat absorbing members. As shown in FIG. 1A, the heat absorbing members 4-1, 4-2, 4-3 are arranged on one side of flat heat pipes arranged in parallel with a predetermined gap (for example, on the same side as the radiation fins). Is thermally connected to the surface. At that time, the holding member shown in FIG. 1B is positioned between the heat pipes and holds a predetermined gap. The heat absorbing member is thermally connected to one heat pipe or thermally connected to two heat pipes according to the amount of heat generated by the heating element.

  FIG.1 (c) is a front view of the heat sink shown to Fig.1 (a). As shown in FIG. 1A, heat radiation fins 3-1 and 3-1 are thermally connected below the both ends of the flat heat pipe 2. Under the central part of the heat pipe, heat absorbing members 4-1, 4-2, 4-3 are thermally connected. The height (thickness) of the heat absorbing member can be appropriately set according to the height of the heating element. That is, the heat-absorbing member is changed in thickness to different heating elements, and the heating element and the heat pipe are thermally connected through the heat-absorbing member.

  FIG. 2 is a plan view seen from the front side for explaining another embodiment of the heat sink of the present invention. In this aspect, a support member that supports two heat pipes arranged in parallel at a predetermined interval is provided. That is, as described with reference to FIGS. 1A to 1C, the two flat heat pipes 2-1 and 2-2 are spaced apart from each other by a predetermined gap on the same plane (for example, horizontal). Are arranged in parallel.

  Radiation fins 3-1 and 3-2 are thermally connected to both end portions of the heat pipes 2-1 and 2-2. The heat radiation fins 3-1 and 3-2 have a flat upper surface thermally connected to one flat surface at both ends of the flat heat pipe. Both ends of the heat pipe are thermally connected over the entire length along the long axis direction of the radiating fin. The cooling air passes through the heat radiating fins along the direction perpendicular to the heat pipe.

  The flat heat pipe is curved so that the central part is retracted. In the aspect shown in FIG. 1, it arrange | positions so that one edge part of a radiation fin may touch the opening part of the side wall of a housing | casing, and the air in a housing | casing is discharge | released out of a housing | casing through a radiation fin. Thus, both ends of the heat pipe are arranged along the side wall of the housing. With respect to both ends of the heat pipe, the central portion of the heat pipe is retreated from the side wall of the housing and is curved toward the inside of the housing.

  Furthermore, the supporting member 5 for supporting the flat type heat pipes 2-1 and 2-2 arranged in parallel is provided. The support member is composed of a support member main body 5-1 disposed along the outer side of each flat heat pipe, bridge portions 5-2 at both ends, and a bridge portion 5-3 at the center. Yes. The support member 5 may further include a fixing member (not shown) used for fixing to the housing or the like. The fixing member may be made of, for example, a leaf spring, or may be made of a float and a screw through the spring. Thus, the support member facilitates protection of the heat pipe and fixation to the housing or the like.

  FIG. 3 is a plan view seen from the back side for explaining another embodiment of the heat sink of the present invention. That is, as described above, the central portion of the heat pipe is curved and retracted so that it can be thermally connected to a plurality of heating elements, and one surface (that is, the back surface) is arranged at a predetermined position. The plurality of heat generators and the heat absorbing members 4-1, 4-2, 4-3 are thermally connected. In addition, what is called dry out can be avoided more effectively by arrange | positioning several heat absorption members substantially in series.

  As described with reference to FIG. 1B, one surface of the heat absorbing member 4 is thermally connected to the heating element. The other surface of the heat absorbing member 4 is thermally connected to the heat pipe. A holding member 6 for holding a predetermined gap between the heat pipes arranged in parallel is attached to a substantially central portion of the heat absorbing member 4. The heat absorbing members 4-1, 4-2, 4-3 are thermally connected to one surface of flat heat pipes arranged in parallel with a predetermined gap therebetween (that is, the surface on the same side as the radiation fins). .

  At that time, as described with reference to FIG. 1B, the holding member is positioned between the heat pipes and holds a predetermined gap. Further, the heat absorbing member is fixed to one surface of the support member main body 5-1 of the support member 5. Thus, the support member has a function of fixing the heat absorbing member in a state where it is thermally connected to the flat heat pipe. Note that the position of the heat absorbing member can be changed according to the arrangement of the heating elements.

  FIG. 4 is a front view of another embodiment of the heat sink of the present invention shown in FIGS. That is, as shown in FIG. 4, the radiation fins 3-1 and 3-1 are thermally connected below the both ends of the flat heat pipe 2. Under the central part of the heat pipe, heat absorbing members 4-1, 4-2, 4-3 are thermally connected. Further, a support member 5-1 that supports the heat pipe covers the side surface of the heat pipe. The bridge portion of the support member protrudes above the heat pipe. Also in this aspect, the height (thickness) of the heat absorbing member can be appropriately set according to the height of the heating element. That is, the heat-absorbing member is changed in thickness to different heating elements, and the heating element and the heat pipe are thermally connected through the heat-absorbing member.

  The heat sink according to the present invention is mounted on a housing of an electric device or the like, and includes a radiating fin portion and a fan (not shown) on the curved direction side of the curved central portion, and the central portion is sucked in a substantially vertical direction. Air cools the outer peripheral surface of the heat pipe through the interval between the heat pipes arranged in parallel and held by the holding member, and is discharged out of the casing through the fin portion by the fan. That is, the cold air that is disposed near the side wall of the housing and is sucked toward the central portion curved toward the inside of the housing is supported by the outer peripheral surface of the heat pipe, the supporting member, the holding member, and the heat absorbing member disposed around the outer surface. The member and the heating element are directly cooled, passed through the inside of the housing, and discharged by the forced air cooling fan through the heat radiation fin disposed in contact with the opening of the side wall of the housing.

  Therefore, not only the outer peripheral surface of the heat pipe is cooled, but also the inside of the housing is cooled by cold air as described above, so that the exterior of the PC (so-called lap top, palm rest, etc.) along with cooling of elements such as CPU and VGA It can be difficult to transmit heat. Further, since the air passage is improved by the provided gap, it is not necessary to turn the fan excessively strongly, and quietness is improved. In addition, it is not necessary to provide an extra fan or air intake, and the weight and cost can be reduced.

  Next, the heat sink according to the present invention is positioned below even when at least one of the plurality of heat pipes is in a state in which the heat pipe portion is inclined and one radiating fin portion is positioned below the heat absorbing member. The working fluid is immersed in the vicinity of the heat absorbing member closest to the heat radiating fin portion. In other words, it is not necessary for the hydraulic fluid to completely immerse the lower endothermic member, as long as the hydraulic fluid is lifted by capillary force or the like. Preferably, in the heat sink described with reference to FIG. 3, when the heat sink is inclined such that the heat absorbing member 4-1 is on the lower side and the heat absorbing member 4-3 is on the upper side, at least two of the heat pipes The working fluid of one heat pipe is provided with working fluid in an amount so that the heat absorbing member 4-1 is almost entirely immersed therein. By providing the working fluid defined in this way, so-called dryout does not occur even in the heat absorbing member 4-3 located on the upper side.

The material of the heat pipe is made of copper, aluminum, or an alloy thereof, and a groove that exhibits a desired capillary force is formed on the inner wall portion, or a mesh or the like is disposed. Use fluid that is highly compatible with the heat pipe material.
As described above, the heat sink of the present invention is extremely thin, compact and excellent in heat dissipation efficiency, and so-called dryout does not occur even when used in an inclined state. Further, the heat generating element, the heat absorbing member, and the outer peripheral surface of the heat pipe are directly cooled by the cold air taken into the casing, so that the thermal efficiency is excellent.

Fig.1 (a) is the top view seen from the front side explaining one aspect | mode of the heat sink of this invention. FIG.1 (b) is a figure explaining an endothermic member. FIG.1 (c) is a front view of the heat sink shown to Fig.1 (a). FIG. 2 is a plan view seen from the front side for explaining another embodiment of the heat sink of the present invention. FIG. 3 is a plan view seen from the back side for explaining another embodiment of the heat sink of the present invention. FIG. 4 is a front view of another embodiment of the heat sink of the present invention shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heat sink 2, 2-1, 2-2 Heat pipe 3, 3-1, 3-2 Radiation fin 4, 4-1, 4-2, 4-3 Heat absorption member 5 Support member 5-1 Support member of this invention Main body 5-2, 5-3 Bridge portion 6 Holding member

Claims (3)

A plurality of heat pipes arranged substantially parallel and substantially horizontally at a predetermined interval are thermally connected to a plurality of heat absorbing members in the vicinity of the center of the heat pipe, and each end of each heat pipe is A heat pipe portion extending in the opposite direction from the connection portion of the heat absorbing member, and
A heat dissipating fin portion that is thermally connected to each of both ends of the heat pipe portion extending in the opposite direction of the heat absorbing member, and is disposed in the vicinity of the side surface of the housing that covers the heat pipe portion and the heat absorbing member ;
With
The heat pipe portion cools an outer peripheral surface of the heat pipe through the predetermined interval of the plurality of heat pipes in which air sucked in a substantially vertical direction is arranged in parallel at a center portion, and further, the radiating fin portion The central portion is curved so as to pass through, and is disposed so as to recede in the inner direction of the housing on the same plane from the both end portions, and the predetermined interval is provided over almost the entire length of the central portion. Heat sink characterized by.   The heat sink according to claim 1, wherein a holding member that holds the predetermined interval is attached to at least one of the heat absorbing members that are thermally connected to the heat-generating component to be cooled.   At least one of the plurality of heat pipes has the heat radiation located below, even when a part of the heat pipe is inclined and one of the heat radiation fins is located below the heat absorption member. The heat sink according to claim 1, wherein the heat sink has an amount of hydraulic fluid that is immersed in the vicinity of the endothermic member closest to the fin portion.

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