JP2005197668A - Heat dissipating structural body of electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat dissipating structure and a heat dissipating structural body accommodating variations in dimension due to component tolerances and improving heat dissipating performance in conducting the heat of heat generating components in an electronic apparatus to dissipate heat outside. <P>SOLUTION: In a heat dissipating structural body HRS1 conducting the heat generated by a heat generating component 2 that is built in the casing of an electronic apparatus outside, the central part 4c of a graphite sheet 4 that is folded and molded resiliently to have flexibility is thermally connected with the heat generating component 2. A flexible conducting member 3 is applied at a part at which the central part 4c is thermally connected with the heat generating component 2. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a heat dissipation structure of a portable electronic device represented by a notebook personal computer, and more particularly to a heat dissipation structure.

  With reference to FIG. 7, a heat dissipation structure in a conventional portable electronic device will be described by taking a notebook personal computer as an example. In a notebook personal computer, the CPU 2 is a heat generating component mounted on the printed circuit board 51, and a heat radiating plate 53 made of copper or aluminum having a thickness of about 0.5 mm to 2.0 mm is brought into close contact with the CPU 2 to generate it. The released heat is released to the outside through the heat radiating plate 53 to radiate heat. If sufficient heat dissipation cannot be expected with such a configuration, a part of the heat dissipation plate 53 is brought into contact with the aluminum keyboard support plate 6 on the back side of the keyboard, and the heat of the CPU 2 is transferred to the keyboard support plate. 6 is also structured to dissipate heat.

  However, metals such as copper and aluminum used for the heat dissipation plate 53 and the keyboard support plate 6 are highly rigid and are not easily deformed by external stress, and the shape such as height is determined. Furthermore, the CPU 2, the heat radiating plate 53, and the keyboard support plate 6 are not completely flat due to manufacturing tolerances, aging, or changes in shape due to heat.

  Therefore, when the height from the CPU 2 to the keyboard support plate 6 is determined structurally, there is necessarily a space (gap between the CPU 2 and the heat dissipation plate 53 and between the heat dissipation plate 53 and the keyboard support plate 6. ) Occurs and cannot adhere to each other. This space acts as a contact thermal resistance between the CPU 2 and the heat radiating plate 53 and between the heat radiating plate 53 and the keyboard support plate 6, and heat transfer from the CPU 2 to the heat radiating plate 53 and the keyboard support plate 6, that is, heat dissipation. Disturb.

  A space (gap) generated between the CPU 2 and the heat dissipation plate 53 is referred to as a heat conduction resistance space IS. The size of the conductive resistance space IS is the resistance distance Dis between the heat dissipation plate 53 and the CPU 2 and the area where the heat conductive resistance space IS extends in a direction parallel to the CPU 2 and the heat dissipation plate 53. The area Ais (not shown) is called, and the size of the heat conduction resistance space IS is called the heat resistance space size Vis.

  In order to reduce the contact thermal resistance, heat radiation grease 56 (not shown) or elastic heat radiation is provided between the CPU 2 and the heat radiation plate 53 and between the heat radiation plate 53 and the keyboard support plate 6, respectively. The invention has been devised (Patent Document 1) to eliminate the above-described heat conduction resistance space IS by interposing a flexible heat conduction member such as the conductive elastomer 57. That is, by replacing the air in the heat conduction resistance space IS generated between the CPU 2 and the heat radiating plate 53 and between the heat radiating plate 53 and the keyboard support plate 6 with a flexible heat conductive member having a higher thermal conductivity than air, The heat transfer is improved. That is, the heat conductive resistance space IS is filled with an amount of the flexible heat conductive member corresponding to the heat resistance space size Vis.

In order to reduce the contact thermal resistance, heat radiation grease 56 (not shown) or elastic heat radiation is provided between the CPU 2 and the heat radiation plate 53 and between the heat radiation plate 53 and the keyboard support plate 6, respectively. The invention has been devised (Patent Document 1) to eliminate the above-described heat conduction resistance space IS by interposing a flexible heat conduction member such as the conductive elastomer 57. That is, by replacing the air in the heat conduction resistance space IS generated between the CPU 2 and the heat radiating plate 53 and between the heat radiating plate 53 and the keyboard support plate 6 with a flexible heat conductive member having a higher thermal conductivity than air, The heat transfer is improved. That is, the heat conductive resistance space IS is filled with an amount of the flexible heat conductive member corresponding to the heat resistance space size Vis.
JP 2001-142574 A

  Actually, the CPU 2, the heat radiating plate 53, and the keyboard support plate 6 each have a plane tolerance, and if a manufacturing tolerance is included, a dimensional tolerance of 0.5 mm or more is generated. Therefore, when the CPU 2, the heat radiating plate 53, and the keyboard support plate 6 are brought into contact with each other, the CPU 2, the heat radiating plate 53, and the keyboard support plate 6 are separated by an interval of 0.5 mm or more. In other words, in order to eliminate the heat conduction resistance space IS having the resistance distance Dis of 0.5 mm, the heat dissipating grease 56 and the heat dissipating elastomer 57 must be filled with a thickness of 0.5 mm or more. Note that the filling amount of the heat-dissipating grease 56 and the heat-dissipating elastomer 57 corresponds to the heat resistance space size Vis of the heat conduction resistance space IS caused by the thermal expansion or contraction of each component generated in the process of heat absorption and heat dissipation from the CPU 2. It must be determined taking into account fluctuations.

  However, the heat conductivity of the heat dissipating grease 56 and the heat dissipating elastomer 57 is larger than the heat conductivity of air, but smaller than the heat conductivity of copper, aluminum, or the like. Compared with the case where the plate 53 is directly adhered, the heat conductivity is inferior. From this viewpoint, it is necessary to reduce the amount of the flexible heat conductive member to be filled as much as possible, that is, to make the heat conduction resistance space IS as small as possible. However, the filling amount of the flexible heat conductive member is applied in a large amount in preparation for the fluctuation of the heat resistance space size Vis of the heat conduction resistance space IS.

  In order to solve the above-mentioned problems, the present invention absorbs variation in dimensions due to component tolerances and dissipates the heat of heat-generating components in electronic equipment to the outside, and improves heat dissipation performance and heat dissipation. An object is to provide a structure.

The present invention is a heat dissipating structure that conducts heat generated by a heat-generating component built in a housing of an electronic device to the outside,
It is possible to be elastically molded by both end portions that are substantially on the same plane, both rising portions that intersect the both end portions at a predetermined angle, and a central portion that is on a plane substantially parallel to the both end portions. A first graphite sheet having flexibility;
A flexible heat conducting member,
In the first graphite sheet, the central portion is thermally connected to the heat generating component, and at least one of the both end portions is heated to at least one of the casing and the heat dissipation component fixed to the casing. Connected,
The flexible conductive member is applied to a portion where the first graphite sheet and the heat generating component are thermally connected.

  In the heat dissipation structure of the electronic device according to the present invention, by utilizing the flexibility of the graphite sheet, the graphite sheet is elastically pressed against a heat-generating component such as a CPU and a heat-dissipating component such as a keyboard support plate on the back of the keyboard. Minimize gaps between them. As a result, the contact thermal resistance between the heat generating component and the graphite sheet and between the graphite sheet and the keyboard support plate is reduced, and the heat dissipation performance of the electronic device is improved.

(First embodiment)
With reference to FIG. 1, a heat dissipation structure and a heat dissipation structure for an electronic device according to a first embodiment of the present invention will be described. FIG. 1 shows a state in which a heat dissipation structure formed inside a notebook personal computer as an example of an electronic device is viewed from the side. Note that members not directly related to the heat dissipation structure such as a housing and a power source are omitted.

  In the notebook personal computer according to the present example, after applying the heat dissipating grease 3 to the CPU 2 which is a heat generating component mounted on the printed wiring board 1, the graphite sheet 4 is flexible and has a high thermal conductivity in the surface direction. The lower surface of the central portion 4c bent with a step is brought into thermal contact with the lower surface of the central portion 4c in a non-fixed manner, and the upper surface of both end portions 4e of the graphite sheet 4 is made of an aluminum keyboard support plate on the back side of the keyboard (not shown) 6 is in close contact with the heat connection. And the graphite sheet 4 is shape | molded by the elastic structure by the rising part 4s which connects the both ends 4e and the center part 4c. That is, simply speaking, in the conventional heat dissipation structure shown in FIG. 7, the heat dissipation plate 53 and the heat dissipation elastomer 57 are replaced with the graphite sheet 4.

  That is, in the present embodiment, the graphite sheet 4 is used as a heat radiating means for conducting the heat of the CPU 2 to the keyboard instead of the heat radiating plate 53. Therefore, the space (gap) formed between the graphite sheet 4 and the CPU 2 is referred to as a heat conduction resistance space IS1, the separation distance between the graphite sheet 4 and the CPU 2 is referred to as a resistance distance Dis1, and the graphite sheet 4 in the heat conduction resistance space IS1. The area in the direction parallel to the CPU 2 is called a resistance area Ais1, and the size of the heat conduction resistance space IS1 is called a heat resistance space size Vis1.

  The graphite sheet 4 is bent and formed from two end portions 4e, two rising portions 4s, and one central portion lower surface 4c as illustrated. That is, the two end portions 4e are located substantially on the same plane, the central portion 4c is located on a plane substantially parallel to the end portion 4e, and the two rising portions 4s are respectively located with respect to the end portion 4e and the central portion 4c. It is formed so as to intersect at a predetermined angle. As a result, the graphite sheet 4 can elastically support the central portion 4c by the rising portion 4s.

  However, the upper surfaces 4e of the both ends of the graphite sheet 4 and the keyboard support plate 6 are securely fixed by mechanical joining means such as screws (not shown). Since the metal heat-dissipating plate 53 in the above-described conventional heat-dissipating structure is highly rigid, a large gap (heat conduction resistance space IS) is formed between the CPU 2 due to tolerance of each component, change with time, or thermal expansion. Arise. On the other hand, the graphite sheet 4 in the present invention is bent by the adsorption force of the heat dissipating grease 3 applied to the CPU 2 and is elastically pressed against the CPU 2 due to its flexibility and the spring effect caused by bending. The gap generated between the CPU 2 and the graphite sheet 4 is absorbed.

  That is, the graphite sheet 4 is easily deformed compared to the heat radiating plate 53 and absorbs variations in dimensions of each component due to manufacturing tolerances, changes with time, and temperature changes. As a result, the resistance distance Dis1 of the heat conduction resistance space IS1 generated between the CPU 2 and the graphite sheet 4 is much smaller than the resistance distance Dis of the heat conduction resistance space IS in the conventional heat dissipation structure, which is 0.5 mm. The minimum size is determined by the surface roughness of the graphite sheet 4 and the CPU 2. As a result, naturally, the resistance area Ais1 and the thermal resistance space size Vis1 of the heat conduction resistance space IS1 can be significantly reduced as compared with the resistance area Ais and the thermal resistance space size Vis of the heat conduction resistance space IS in the conventional heat dissipation structure.

  As described above, in the present invention, the manufacturing tolerance of the component is absorbed by bending of the graphite sheet 4 in the heat conduction resistance space IS1 that is generated between the graphite sheet 4 and the CPU 2 and acts as a contact thermal resistance. Thus, the surface roughness of the graphite sheet 4 and the CPU 2 can be reduced. Furthermore, the graphite sheet 4 can also absorb the dimensional change of the component by time and a heat change by the flexibility.

  However, the amount of the heat dissipating grease 3 applied to the heat conduction resistance space IS1 generated between the graphite sheet 4 and the CPU 2 is a small amount corresponding to the heat resistance space size Vis1. Specifically, the amount of the heat dissipating grease 3 to be applied is 0.3 mm or less and a resistance distance Dis1 or more, which is a thickness that can be applied thinly.

  Thereby, compared with the installation area between the graphite sheet 4 and the keyboard support plate 6, the contact thermal resistance between the CPU 2 and the graphite sheet 4 having a small installation area can be reduced, so that the heat of the CPU 2 is effectively absorbed. Can be moved. Since the graphite sheet 4 and the keyboard support plate 6 are in close mechanical contact, the heat of the CPU 2 is efficiently conducted to the keyboard support plate 6 via the graphite sheet 4. Thus, in the heat dissipation structure in the present invention, the heat dissipation performance as a whole is improved by reducing the contact heat resistance between the heat generating portion, the heat absorbing portion, and the heat dissipation portion, as compared with the conventional heat dissipation structure described above. doing.

  As described above, in the present invention, a flexible graphite sheet having a high thermal conductivity in the plane direction is bent with a step and used as a heat radiating plate. This allows the graphite sheet to be deformed by utilizing the flexibility of the graphite sheet even in the case where there is a gap between the heat generating component and the heat radiating plate or between the heat radiating plate and the keyboard support plate due to the tolerance of each component. Thus, it is possible to prevent a gap from being generated between the heat generating component and the graphite sheet and between the graphite sheet and the keyboard support plate without causing residual stress. Furthermore, the graphite sheet has good heat conductivity and can improve the heat dissipation performance of the entire electronic device.

  In order to improve workability for forming the heat dissipation structure, a thin heat dissipating elastomer having a strong adsorbing force may be used instead of the heat dissipating grease 3, or these may be combined. Moreover, the graphite sheet 4 used as a means for absorbing and moving the heat of the CPU 2 has a thermal conductivity in the plane direction of 100 (W / mK) or more, a thickness of 0.5 to 2.0 mm, and has flexibility. However, it is needless to say that it is appropriately determined according to the shape and size of each element constituting the heat dissipation structure to be used, manufacturing tolerances, the heat generation amount of the CPU 2, the required heat dissipation amount, and the like.

  In the present embodiment, the graphite sheet 4 and the heat dissipating grease 3 are the minimum units constituting the heat dissipating structure HRS1 that realizes the function of depriving (absorbing) the heat generated by the CPU 2. Furthermore, in order to release the heat taken from the CPU 2 to the outside of the personal computer, a keyboard support plate 6 is also provided as a component of the heat dissipation structure HRS1.

  In this example, as shown in FIG. 1, the rising portion 4s of the graphite sheet 4 is bent so as to have a tolerance at a predetermined angle with respect to the lower surface 4c and both ends 4e of the central portion, and is substantially trapezoidal. Molded. As a result, the graphite sheet 4 has a spring effect and acts to press the central portion lower surface 4c against the CPU 2. Therefore, the graphite sheet 4 may have a rectangular shape or a curved shape, for example, as long as the lower surface 4c of the central portion of the graphite sheet 4 can be stably pressed against the CPU 2 with a desired spring effect.

(Second Embodiment)
With reference to FIG. 2, the heat dissipation structure of the electronic device which concerns on the 2nd Embodiment of this invention is demonstrated. As in FIG. 1, FIG. 2 shows a state in which a heat dissipation structure configured in a notebook personal computer as an example of an electronic device is viewed from the side. The heat dissipation structure HRS2 according to the present embodiment is configured by adding an elastic body 8 to the heat dissipation structure HRS1 illustrated in FIG. In the present embodiment, a space (gap) formed between the graphite sheet 4 and the CPU 2 is called a heat conduction resistance space IS2, and a separation distance between the graphite sheet 4 and the CPU 2 is called a resistance distance Dis2, and the heat conduction resistance. The area of the space IS2 in the direction parallel to the graphite sheet 4 and the CPU 2 is called a resistance area Ais2, and the size of the heat conduction resistance space IS2 is called a heat resistance space size Vis2.

The elastic body 8 is disposed in a space formed between the graphite sheet 4 and the keyboard support plate 6. The elastic body 8 is formed of an elastic material such as urethane foam or melamine foam, and its length L8 is such that the thickness of the graphite sheet 4 is Tg, and the CPU 2 If the distance to the upper surface of L is L, it can be expressed by the following equation (1).
L8 = L-Tg-Dis2 + ΔL (1)
ΔL is a compression length of the elastic body 8 and is a predetermined length necessary for applying a predetermined pressure to the CPU 2. Specifically, ΔL is the amount of deflection of the graphite sheet 4, the elastic coefficient of the elastic body 8, the contact area of the elastic body 8 with the CPU 2 and the graphite sheet 4, and the pressing force required for the CPU 2 of the graphite sheet 4. It is determined appropriately based on the above.

  Since the elastic body 8 is compressed between the graphite sheet 4 and the keyboard 5 which are securely fixed to each other by screwing or the like, the lower surface of the central portion of the graphite sheet 4 bent by the reaction force is pressed against the CPU 2. . As a result, the graphite sheet 4 is more closely attached to the CPU 2 than the heat dissipation structure HRS1 by the pressing force of the elastic body 8 in addition to the spring effect due to its bending structure.

  From the above equation (1), it can be seen that the resistance distance Dis2 can be reduced by increasing the compression length ΔL. That is, since the CPU 2 and the graphite sheet 4 are more closely attached than in the heat dissipation structure HRS1, the resistance distance Dis2, the resistance area Ais2, and the thermal resistance space size Vis2 are the resistance distance Dis1, the resistance area, respectively. It can be made smaller than Ais1 and the thermal resistance space size Vis1. In other words, since the heat conduction resistance space IS2 can be made smaller than the heat conduction resistance space IS1, the amount of the heat dissipating grease 3 to be applied can also be reduced.

  Thereby, since the quantity of the flexible heat conductive member applied between the CPU 2 and the graphite sheet 4 can be reduced, the contact thermal resistance between the graphite sheet 4 and the keyboard support plate 6 can be reduced, and the heat dissipation structure HRS2 The heat dissipation performance can be improved compared to the heat dissipation structure HRS1.

  With reference to FIG. 3, the 1st modification of the thermal radiation structure HRS2 concerning 2nd Embodiment is demonstrated. In the heat dissipation structure HRS2a according to this modification, the elastic body 8 in the heat dissipation structure HRS2 is replaced with a leaf spring 8A, and the graphite sheet 4 is replaced with a graphite sheet 4A. The graphite sheet 4A is configured by covering the surface of the graphite sheet 4 with a thin film resin such as polyester foil in order to protect it from damage due to contact with the leaf spring 8A. In this modification, the leaf spring 8A is attached to the keyboard support plate 6. However, if there is a problem in strength, it may be attached to another part of the personal computer, for example, a housing.

  The elastic body 8 and the leaf spring 8A described above are shown in FIGS. 2 and 3 as long as the central lower surface 4c of the graphite sheet 4 can be stably pressed against the CPU 2 with a desired compression force. You may comprise in arbitrary shapes other than the shape shown.

  With reference to FIG. 4, the 2nd modification of the thermal radiation structure HRS2 concerning 2nd Embodiment is demonstrated. In the heat dissipation structure HRS2B according to this modification, the graphite sheet 4 in the heat dissipation structure HRS2 described above is replaced with a graphite sheet 4B. The graphite sheet 4B is not bent into an elastic structure like the graphite sheet 4 and the graphite sheet 4A, and a single graphite sheet is used as it is. That is, the graphite sheet 4B does not have a portion that directly corresponds to each of the both end portions 4e, the rising portion 4s, and the central portion 4c of the graphite sheet 4 and the graphite sheet 4A. The parts are identified as both end parts 4eB, rising parts 4sB, and central part 4cB.

  In the heat dissipating structure HRS2B, the central portion 4cB of the graphite sheet 4B hangs down, and both end portions 4eB are mechanically fixed to the keyboard support plate 6 so that the CPU 2 can contact the CPU 2 with a predetermined area or more. The positions at which the both ends 4eB are fixed to the keyboard support plate 6 may be substantially the same as the positions at which the both ends 4e are fixed to the keyboard support plate 6. However, since the graphite sheet 4B does not have an elastic structure, the heat conduction resistance space IS2 formed between the graphite sheet 4 and the CPU 2 cannot be eliminated, and even the lower surface of the central portion 4cB is in surface contact with the surface of the CPU 2. It is difficult.

  Therefore, the lower surface of the central portion 4cB is pressed against and tightly contacts the CPU 2 by the elastic body 8 provided between the keyboard support plate 6 and the graphite sheet 4B. The graphite sheet 4B fixed to the keyboard support plate 6 in a bent state is also a kind of elastic body structure. However, the graphite sheet 4B cannot be expected to adhere to the CPU 2 due to the pressing force resulting from the bent elastic body structure as in the graphite sheet 4 or the graphite sheet 4B. Therefore, it is preferable that the cross-sectional area of the elastic body 8 used for the heat dissipation structure HRS2B is larger than the surface area of the CPU 2 in order to ensure that the lower surface of the central portion 4cB is in close contact with the entire surface of the CPU 2. Instead of the elastic body 8, the above-described leaf spring 8A may be used. Further, when the leaf spring 8A is used, the graphite sheet 4B has a thin film resin such as a polyester foil in order to protect the graphite sheet 4B from damage caused by contact with the leaf spring 8A, similarly to the graphite sheet 4A. It is desirable to be covered with.

  As described above, in the heat dissipating structure HRS2B, the graphite sheet 4B does not need to be bent, so that it is excellent in workability as compared with the graphite sheet 4 and the graphite sheet 4A. In addition, the graphite sheet 4 and the graphite sheet 4A need to be bent and formed in advance according to the shape and size of the portion to be attached. And the graphite sheet 4 and the graphite sheet 4A which have been bent in advance as described above cannot be used for heat radiation of other portions because the portions to which they are attached are strongly restricted. On the other hand, since the graphite sheet 4B can be used without being bent, the degree of restriction on the place where the graphite sheet 4B can be attached is weak, which is more economical.

(Third embodiment)
With reference to FIG. 4, the heat dissipation structure of the electronic device which concerns on the 3rd Embodiment of this invention is demonstrated. As in FIG. 1, FIG. 3 shows a cross section of a heat dissipation structure configured in a notebook personal computer as an example of an electronic device. In the heat dissipation structure HRS3 according to the present embodiment, the graphite sheet 4 is replaced with a graphite laminate sheet 14 in the heat dissipation structure HRS1 shown in FIG. In the present embodiment, a space (gap) formed between the graphite laminated sheet 14 and the CPU 2 is called a heat conduction resistance space IS3 (not shown), and the separation distance between the graphite laminated sheet 14 and the CPU 2 is a resistance distance. Called Dis3 (not shown), the area of the heat conduction resistance space IS3 in the direction parallel to the graphite laminated sheet 14 and the CPU 2 is called resistance area Ais3, and the size of the heat conduction resistance space IS3 is the heat resistance space size Vis3. Call.

  The graphite laminated sheet 14 is a flexible graphite sheet 14a having a thermal conductivity in the plane direction of 100 (W / mK) or more and a thickness of 0.5 to 2.0 mm, and a thickness of 0.01 mm to 0.2 mm. It is formed by being sandwiched between metal foils 14b such as thin aluminum foil or copper foil. It is to be noted that the upper surfaces of both ends of the graphite laminated sheet 14 and the keyboard support plate 6 are firmly and firmly fixed by mechanical means such as screws as in the heat dissipation structure HRS1.

  In the present embodiment, the graphite laminated sheet 14 is composed of a flexible graphite sheet 14a and a thin metal foil 14b, so that the graphite laminated sheet 14 bends due to the adsorption force of the heat dissipating grease 3 applied to the CPU 2. As a result, there is no gap between the CPU 2 and the graphite laminated sheet 14.

  Thereby, the thermal resistance between the CPU 2 and the graphite laminated sheet 14 and between the graphite laminated sheet 14 and the keyboard support plate 6 can be reduced, and the metal foil 14b on the surface of the graphite laminated sheet 14 is made of graphite laminated. Since the volume specific heat is higher than that of the graphite sheet 14a in the center of the sheet 14 and the thermal conductivity is equal to or higher than that of the graphite sheet 14a. Can be increased.

(Fourth embodiment)
With reference to FIG. 6, the heat dissipation structure of the electronic device which concerns on the 4th Embodiment of this invention is demonstrated. FIG. 6 shows a cross section of a heat dissipation structure configured in a notebook personal computer as an example of an electronic device, as in FIG. In addition, the heat dissipation structure HRS4 according to the present embodiment includes a graphite sheet 17 having a thickness of 0.1 mm to 1.0 mm between the graphite sheet 4 and the keyboard support plate 6 in the heat dissipation structure HRS1 shown in FIG. Has been.
The graphite sheet 17 is affixed to the keyboard support plate 6. The upper surfaces of both ends of the graphite sheet 4 are securely fixed in close contact with the keyboard support plate 6 by mechanical means such as screws via the graphite sheet 17 and thermally connected.
In the present embodiment, the space (gap) formed between the graphite sheet 4 and the CPU 2 is called a heat conduction resistance space IS4 (not shown), and the separation distance between the graphite sheet 4 and the CPU 2 is the resistance distance Dis4 ( The area of the heat conduction resistance space IS4 in the direction parallel to the graphite sheet 4 and the CPU 2 is called a resistance area Ais4, and the size of the heat conduction resistance space IS4 is called a heat resistance space size Vis4.

  Since the contact thermal resistance between the graphite sheet 17 and the graphite sheet 4 is smaller than the contact thermal resistance between the graphite sheet 4 and the keyboard support plate 6, the high thermal conductivity in the surface direction of the graphite sheet 17 and the cross-sectional direction. By utilizing the low thermal conductivity of heat, the heat from the graphite sheet 4 is released to the graphite sheet 17 affixed to the keyboard support plate 6 to further improve the heat radiation performance in the surface direction compared to the heat radiation structure HRS1. The temperature of the keyboard surface can be lowered.

  Although the embodiments have been described individually as described above, it goes without saying that they can be combined with each other. As described above, the present invention can be used for heat dissipation of portable electronic devices such as notebook personal computers.

  The present invention can be used for heat dissipation of portable electronic devices such as notebook personal computers.

The side view showing the thermal radiation structure concerning a 1st embodiment of the present invention The side view showing the thermal radiation structure concerning the 2nd Embodiment of this invention The side view showing the modification of the thermal radiation structure shown in FIG. The side view showing the further modification of the thermal radiation structure shown in FIG. Side view showing a heat dissipation structure according to a third embodiment of the present invention Side view showing a heat dissipation structure according to a fourth embodiment of the present invention Side view showing a conventional heat dissipation structure

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Printed wiring board 2 Heat generating component 3 Heat dissipation grease 4 Graphite sheet 4c Center part lower surface 4e Both-ends upper surface 6 Keyboard support plate 8 Elastic body 8a Leaf spring 14 Graphite laminated sheet 14a Graphite sheet 14b Metal foil 17 Graphite sheet 53 Heat dissipation plate 57 Heat dissipation Elastomer

Claims (15)

A heat dissipating structure that conducts heat generated by a heat generating component built in a housing of an electronic device to the outside,
It is possible to be elastically molded by both end portions that are substantially on the same plane, both rising portions that intersect the both end portions at a predetermined angle, and a central portion that is on a plane substantially parallel to the both end portions. A first graphite sheet having flexibility;
A flexible heat conducting member,
In the first graphite sheet, the central portion is thermally connected to the heat generating component, and at least one of the both end portions is heated to at least one of the casing and the heat dissipation component fixed to the casing. Connected,
The heat radiating structure, wherein the flexible conductive member is applied to a portion where the first graphite sheet and the heat generating component are thermally connected.   The heat dissipation structure according to claim 1, wherein the first graphite sheet is bent and molded.   The heat dissipation structure according to claim 1, wherein the heat dissipation component is a keyboard support plate of an electronic device.   The heat dissipation structure according to claim 1, wherein the central portion of the first graphite sheet is non-fixedly connected to the heat generating component.   The at least one of the both end portions of the first graphite sheet is fixedly connected to at least one of the casing and a heat dissipation component fixed to the casing. Heat dissipation structure.   The heat dissipation structure according to claim 4, further comprising an elastic body that presses the central portion of the first graphite sheet against the heat generating component.   A second graphite sheet is further provided between at least one of the both end portions of the first graphite sheet and the heat dissipating component, and at least one of the both end portions is radiated by the second graphite sheet. The heat dissipation structure according to claim 1, wherein the heat dissipation structure is thermally connected to a component.   The heat dissipation structure according to claim 1, wherein a thickness of the first graphite sheet is 0.5 mm or more and 2.0 mm or less.   The heat dissipation structure according to claim 7, wherein the thickness of the second graphite sheet is 0.1 mm or more and 1.0 mm or less.   9. The heat dissipation structure according to claim 8, wherein the first graphite sheet is laminated by sandwiching any one of an aluminum foil and a copper foil having a thickness of 0.01 mm or more and 0.2 mm or less. body.   The heat dissipation structure according to claim 4, wherein the flexible heat conducting member is one of a heat dissipating grease and a heat dissipating elastomer having adsorbing power.   The heat dissipation structure according to claim 11, wherein the heat dissipation grease and the heat dissipation elastomer have a thickness of 0.3 mm or less.   The heat dissipation structure according to claim 8, wherein the first graphite sheet is covered with a thin film resin. A heat dissipating structure that conducts heat generated by a heat generating component built in a housing of an electronic device to the outside,
A first graphite sheet thermally connected to the heat generating component;
A second graphite sheet thermally connected to at least one of the casing and a heat dissipation component fixed to the casing;
A third graphite sheet for thermally connecting the first graphite sheet and the second graphite sheet; and the third graphite sheet is connected to the first graphite sheet and the second graphite sheet. And a heat dissipating structure characterized by intersecting each other at a predetermined angle. A heat dissipating structure that conducts heat generated by a heat generating component built in a housing of an electronic device to the outside,
A graphite sheet having both ends thermally connected to at least one of the housing and the heat dissipating component fixed to the housing, and a central portion thermally connected to the heat generating component;
A heat dissipation structure including an elastic body that presses the central portion of the graphite sheet against the heat generating component.

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