US20120318484A1

US20120318484A1 - Heat-dissipation structure and display unit

Info

Publication number: US20120318484A1
Application number: US13/490,563
Authority: US
Inventors: Takeaki HIRASAWA
Original assignee: Sony Corp
Current assignee: Sony Corp
Priority date: 2011-06-17
Filing date: 2012-06-07
Publication date: 2012-12-20
Also published as: CN102833984A; JP2013004783A

Abstract

A heat-dissipation structure includes: a heat-dissipation member between a high-temperature section and a low-temperature section, wherein the heat-dissipation member includes a cushion section being made of a flexible material, and a heat-transfer section being provided in part or an entire surface of the cushion section, and being in contact with both the high-temperature section and the low-temperature section.

Description

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority from Japanese Patent Application No. JP 2011-135120 filed in the Japanese Patent Office on Jun. 17, 2011, the entire content of which is incorporated herein by reference.

BACKGROUND

The present disclosure relates to a heat-dissipation structure dissipating or cooling heat generated by an electronic part, a light emitting device, or the like and a display unit including the same.
An electronic part, a light emitting device, or the like generates a large amount of heat at the time of operation. Therefore, to avoid characteristics deterioration or the like due to high temperature, the generated heat should be dissipated and cooled. For example, in Japanese Unexamined Patent Application Publication No. 2007-163620, it is proposed that in a liquid crystal display, a heat-conductive double-faced tape as a heat-dissipation member is adhered to a rear surface of a circuit board mounted with an LED (light emitting diode) light source, and is fixed to a lower frame.

SUMMARY

In the foregoing existing configuration, in order to improve heat-transfer performance, it is important to secure contact between the circuit board as a heat source and the heat-dissipation member or contact between the circuit board as a heat source, and a primary heat-dissipation member and a secondary heat-dissipation member (if the primary heat-dissipation member and the secondary heat-dissipation member exist) by pressurization or by inserting an adhesive member in between. However, there has been a disadvantage that depending on a pressurization structure or an adhesive structure, it results in a gap in between, and heat-transfer efficiency is lowered.
It is desirable to provide a heat-dissipation structure capable of improving heat-transfer performance and a display unit including the same.
According to an embodiment of the present disclosure, there is provided a heat-dissipation structure including: a heat-dissipation member between a high-temperature section and a low-temperature section, wherein the heat-dissipation member includes a cushion section being made of a flexible material, and a heat-transfer section being provided in part or an entire surface of the cushion section, and being in contact with both the high-temperature section and the low-temperature section.
According to an embodiment of the present disclosure, there is provided a display unit including: a heat-dissipation member between a high-temperature section including a display device and a low-temperature section, wherein the heat-dissipation member includes a cushion section being made of a flexible material, and a heat-transfer section being provided in part or an entire surface of the cushion section, and being in contact with both the high-temperature section and the low-temperature section.
In the heat-dissipation structure or the display unit according to the embodiment of the present disclosure, contact between the heat-transfer section and the high-temperature section and contact between the heat-transfer section and the low-temperature section are secured by elasticity of the cushion section, and heat is transferred from the high-temperature section to the low-temperature section through the heat-transfer section.
In the heat-dissipation structure or the display unit according to the embodiment of the present disclosure, the heat-dissipation member includes the heat-transfer section in part or the entire surface of the cushion section made of the flexible material, and the heat-transfer section is in contact with both the high-temperature section and the low-temperature section. Therefore, elasticity of the cushion section assures that the heat-transfer section is surely in contact with the high-temperature section and the low-temperature section, and heat transfer efficiency by the heat-transfer section is allowed to be improved.
It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the technology as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a further understanding of the disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments and, together with the specification, serve to explain the principles of the technology.

FIG. 1 schematically illustrates a configuration of a heat-dissipation structure according to an embodiment of the present disclosure.

FIG. 2 is a perspective view illustrating an appearance of a heat-dissipation member illustrated in FIG. 1.

FIG. 3 is view illustrating a modification of the heat-dissipation member illustrated in FIG. 1.

FIG. 4 is a view schematically illustrating a configuration of a heat-dissipation structure according to a first modification.

FIG. 5 is a view schematically illustrating a configuration of a heat-dissipation structure according to a second modification.

FIGS. 6A to 6E are perspective views illustrating appearances of heat-dissipation members according to a third modification to a sixth modification.

FIG. 7 is a perspective view illustrating shapes after the heat-dissipation members illustrated in FIGS. 6A to 6E are crushed.

FIG. 8 is a perspective view illustrating an appearance of a heat-dissipation member according to a seventh modification.

FIG. 9 is a perspective view illustrating a configuration of a display unit having the heat-dissipation structure illustrated in FIG. 1 seen from the front surface side.

FIG. 10 is a cross-sectional view taken along a line X-X of FIG. 9.

FIG. 11 is a perspective view illustrating a configuration of a display unit having the heat-dissipation structure illustrated in FIG. 1 seen from the rear surface side.

FIG. 12 is a cross-sectional view taken along a line XII-XII of FIG. 11.

FIG. 13 is a plan view illustrating a configuration of a real measurement system in an example according to the embodiment of the present disclosure.

FIG. 14 is a cross-sectional view illustrating a heat-dissipation structure according to a first example.

FIG. 15 is a cross-sectional view illustrating a heat-dissipation structure according to a comparative example 1.

FIG. 16 is a cross-sectional view illustrating a heat-dissipation structure according to a comparative example 2.

DETAILED DESCRIPTION

An embodiment of the present disclosure will be hereinafter described in detail with reference to the drawings.
FIG. 1 schematically illustrates an outline configuration of a heat-dissipation structure according to an embodiment of the present disclosure. The heat-dissipation structure is used for dissipating or cooling heat of an electronic part or a light emitting device arranged in various electronic devices such as a display unit. The heat-dissipation structure includes a heat-dissipation member 30 between a high-temperature section 10 and a low-temperature section 20.
The high-temperature section 10 is a substrate mounted with an electronic part or a light emitting device (not illustrated) as a heat source, or a member that is directly in contact with or is adjacent to the electronic part or the light emitting device. The low-temperature section 20 is a member arranged on the electronic part or the light emitting device with the high-temperature section 10 and the heat-dissipation member 30 in between. Heat generated in the electronic part or the light emitting device is firstly transferred to the high-temperature section 10, and is subsequently dissipated from the high-temperature section 10 to the low-temperature section 20 through the heat-dissipation member 30 as indicated by arrows A1 and A2. In general, the low-temperature section 20 has a wide heat-dissipation area. Heat-dissipation from the low-temperature section to the atmosphere or the like is important in order to cool the heat source.
The high-temperature section 10 and the low-temperature section 20 may be fixed to each other by a screw, an adhesive, or the like. Alternately, one thereof may be relatively moved with respect to the other thereof. Specific examples of the latter case include a case in which the high-temperature section 10 is expanded or shrunk due to heat and thereby moves (slides) along a borderline between the high-temperature section 10 and the low-temperature section 20 as indicated by an arrow A3. In this case, a gap G is desirably provided in the borderline between the high-temperature section 10 and the low-temperature section 20 to facilitate the relative movement of the high-temperature section 10.
FIG. 2 illustrates an appearance of the heat-dissipation member 30 illustrated in FIG. 1. The heat-dissipation member 30 has, for example, a heat-transfer section 32 on the surface of a cushion section 31 made of a flexible material. The heat-transfer section 32 is in contact with both the high-temperature section 10 and the low-temperature section 20. Thereby, in the heat-dissipation structure, heat-transfer performance is improved.
That is, in the past, a material having electric insulation properties and high heat conductivity such as a heat-dissipation sheet (or a heat-dissipation pad) made of, for example, a urethane-based material is provided for cooling an electronic part or the like. However, in the existing heat-dissipation sheet, a material composition should be changed to change cushioning characteristics (elasticity), and cushioning characteristics are not allowed to be adjusted independently of heat conductivity. Further, for giving cushioning characteristics to the existing heat-dissipation sheet, air should be therein aerated, and accordingly heat conductivity is lowered.
Meanwhile, in the heat-dissipation member 30 according to this embodiment, the cushion section 31 playing a main role as cushioning characteristics exists separately from the heat-transfer section 32 playing a main role as heat transfer, and thereby cushioning characteristics and heat transfer are allowed to be respectively controlled independently. The cushioning characteristics of the cushion section 31 assure that the heat-transfer section 32 is surely in contact with the high-temperature section 10 and the low-temperature section 20, and therefore heat conductivity efficiency due to the heat-transfer section 32 is allowed to be improved. It is to be noted that the cushioning characteristics of the cushion section 31 are allowed to be adjusted by, for example, 25% compressive loading or the like.
Such a cushion section 31 is made of a flexible material such as a rubber sheet and urethane foam (for example, “PORON (registered trademark)” available from Rogers inoac corporation). For a cross-sectional shape of the cushion section 31, for example, in addition to an oval illustrated in FIG. 2, various deformed shapes such as after-mentioned third to seventh modifications are allowed to be adopted. The length of the cushion section 31 may be determined as needed.
Further, the cushion section 31 may be made of a material having cushioning characteristics and heat conductivity, for example, the foregoing material having high heat conductivity such as the heat-dissipation sheet made of a urethane-based material. Thereby, as illustrated in FIG. 3, a heat-dissipation path through the heat-transfer section 32 (arrows A1 and A2) and a heat-dissipation path through the cushion section 31 (arrow A4) are formed, and heat-transfer performance is further improved.
The heat-transfer section 32 is made of a high thermal conducting member such as a graphite sheet, a copper (Cu) foil, and an aluminum (Al) foil. The heat-transfer section 32 is adhered to the cushion section 31 by, for example, a double-faced adhesive tape (not illustrated).
A covering layer 33 (see FIG. 2) that decreases surface friction resistance is preferably provided on the surface of the heat-transfer section 32. As the covering layer 33, for example, a plastic film made of, for example, a PET (polyethylene terephthalate) being about 0.1 mm thick may be adhered to the surface of the heat-transfer section 32. It is to be noted that the covering layer 33 is not illustrated in the figures other than FIG. 2.
The heat-dissipation structure may be manufactured, for example, as follows. The cushion section 31 and the heat-transfer section 32 are prepared, the heat-transfer section 32 is wound around the cushion section 31, the heat-transfer section 32 is adhered to the cushion section 31 by using a double-faced adhesive tape, and thereby the heat-dissipation member 30 is formed. Next, the heat-dissipation member 30 is arranged between the high-temperature section 10 and the low-temperature section 20.
In the heat-dissipation structure, heat generated in the electronic part or the light emitting device is firstly transferred to the high-temperature section 10, and is subsequently dissipated from the high-temperature section 10 to the low-temperature section 20 through the heat-dissipation member 30 as indicated by the arrows A1 and A2. In this case, contact between the heat-transfer section 32 and the high-temperature section 10 and contact between the heat-transfer section 32 and the low-temperature section 20 are secured by the cushioning characteristics of the cushion section 31, and heat is transferred from the high-temperature section 10 to the low-temperature section 20 through the heat-transfer section 32.
Further, in the case where the high-temperature section 10 slides in the direction of the arrow A3, while the heat-dissipation member 30 slides along with the high-temperature section 10, the heat-dissipation member 30 is in contact with both the high-temperature section 10 and the low-temperature section 20 and thereby promotes heat transfer. That is, contact between the heat-transfer section 32 and the high-temperature section 10 and contact between the heat-transfer section 32 and the low-temperature section 20 are secured by the cushioning characteristics of the cushion section 31, and heat is transferred from the high-temperature section 10 to the low-temperature section 20 through the heat-transfer section 32. Therefore, heat transfer and heat-dissipation are performed without inhibiting sliding characteristics of the high temperature section 10.
Meanwhile, in the past, pressurization fixation with the use of a screw or the like has been performed for securing contact between a member to be cooled and a heat-dissipation sheet. Such pressurization fixation inevitably results in losing position freedom degree. Therefore, in a location where sliding occurs, sufficient pressurization or sufficient adhesion is not allowed to be performed for securing position freedom degree, heat transfer efficiency is degraded, and position freedom degree (sliding characteristics) is not compatible with heat transfer efficiency.
As described above, in this embodiment, the heat-dissipation member 30 includes the cushion section 31 made of a flexible material and the heat-transfer section 32 that is provided in part or the entire surface of the cushion section 31 and is in contact with both the high-temperature section 10 and the low-temperature section 20. Therefore, the cushioning characteristics of the cushion section 31 assures that the heat-transfer section 32 is surely in contact with the high-temperature section 10 and the low-temperature section 20, and therefore heat transfer efficiency due to the heat-transfer section 32 is improved.
Further, in the case where the high-temperature section 10 is expanded or shrunk due to heat, and the high-temperature section 10 and the low-temperature section 20 relatively move (slide), heat transfer performance is secured as well, and position freedom degree (sliding characteristics) is compatible with heat transfer efficiency.
In particular, in the case where the high-temperature section 10 including a heat source such as an electronic part and a light emitting device slides, heat-dissipation efficiency of the heat source is improved and the device is operatable in a higher energy, and performance of the device is improved. Further, the number of light sources is allowed to be decreased, a heat source with high energy is allowed to be used, and cost is allowed to be reduced.
It is to be noted that in the foregoing embodiment, the description has been given of the case in which the heat-transfer section 32 is provided in the whole surface of the cushion section 31. However, it is enough that the heat-transfer section 32 is provided in part or the entire surface of the cushion section 31 (a region where the heat-dissipation member is in contact with the high-temperature section 10 or the low-temperature section 20, or a region where the heat-dissipation member is allowed to be contacted with the high-temperature section 10 or the low-temperature section 20 by pressing force). In the following first modification and second modification, a description will be given of a case in which the heat-transfer section 32 is provided in part of the surface of the cushion section 31.

First Modification

FIG. 4 illustrates a schematic configuration of a heat-dissipation structure according to the first modification. In this modification, two cushion sections 31A and 31B are provided, and the heat-transfer section 32 is provided in the shape of S between the surface on the high-temperature section 10 side of one cushion section 31A and the surface on the low-temperature section 20 side of the other cushion section 31B. The modification is particularly suitable for a case in which due to small dimensions, the heat-transfer section 32 is difficult to be wound around the cushion sections 31A and 31B. In the modification, peeling of the heat-transfer section 32 is suppressed. Except for the above-mentioned characteristics, the heat-dissipation structure has configurations, functions and effects similar to those of the foregoing embodiment, and is allowed to be manufactured as in the foregoing embodiment.
In the heat-dissipation structure, heat produced in an electronic part or a light emitting device (not illustrated) is firstly transferred to the high-temperature section 10, and is subsequently dissipated from the high-temperature section 10 to the low-temperature section 20 through the heat-dissipation member 30 as indicated by arrow A5. In this case, contact between the heat-transfer section 32 and the high-temperature section 10 and contact between the heat-transfer section 32 and the low-temperature section 20 are secured by the cushioning characteristics of the cushion section 31, and heat is transferred from the high-temperature section 10 to the low-temperature section 20 through the heat-transfer section 32.
Further, in the case where the high-temperature section 10 slides in the direction of the arrow A3, while the heat-dissipation member 30 slides along with the high-temperature section 10, the heat-dissipation member 30 is in contact with both the high-temperature section 10 and the low-temperature section 20 and thereby promotes heat transfer. That is, contact between the heat-transfer section 32 and the high-temperature section 10 and contact between the heat-transfer section 32 and the low-temperature section 20 are secured by the cushioning characteristics of the cushion section 31, and heat is transferred from the high-temperature section 10 to the low-temperature section 20 through the heat-transfer section 32. Therefore, heat transfer and heat-dissipation are performed without inhibiting sliding characteristics of the high temperature section 10.

Second Modification

FIG. 5 illustrates a schematic configuration of a heat-dissipation structure according to the second modification. In this modification, one end of the heat-transfer section 32 covers the surface on the high-temperature section 10 side of the cushion section 31, and the other end of the heat-transfer section 32 is fixed to the low-temperature section 20 by a fixing section 34 such as a double-faced adhesive tape. The modification is particularly suitable for a case in which due to small dimensions, the heat-transfer section 32 is difficult to be wound around the cushion sections 31A and 31B as in the first modification. In the modification, peeling of the heat-transfer section 32 is allowed to be suppressed as in the first modification. Except for the above-mentioned characteristics, the heat-dissipation structure has configurations, functions and effects similar to those of the foregoing embodiment, and is allowed to be manufactured as in the foregoing embodiment.
In the heat-dissipation structure, heat generated in an electronic part or a light emitting device (not illustrated) is firstly transferred to the high-temperature section 10, and is subsequently dissipated from the high-temperature section 10 to the low-temperature section 20 through the heat-dissipation member 30 as indicated by arrow A6. In this case, contact between the heat-transfer section 32 and the high-temperature section 10 is secured by the cushioning characteristics of the cushion section 31, and heat is transferred from the high-temperature section 10 to the low-temperature section 20 through the heat-transfer section 32.
Further, in the case where the high-temperature section 10 slides in the direction of the arrow A3, while the heat-dissipation member 30 slides along with the high-temperature section 10, the heat-dissipation member 30 is in contact with both the high-temperature section 10 and the low-temperature section 20 and thereby promotes heat transfer. That is, contact between the heat-transfer section 32 and the high-temperature section 10 and contact between the heat-transfer section 32 and the low-temperature section 20 are secured by the cushioning characteristics of the cushion section 31, and heat is transferred from the high-temperature section 10 to the low-temperature section 20 through the heat-transfer section 32. Therefore, heat transfer and heat-dissipation are performed without inhibiting sliding characteristics of the high temperature section 10.
Though not illustrated, one end of the heat-transfer section 32 may cover the surface on the low-temperature section 20 side of the cushion section 31, and the other end of the heat-transfer section 32 may be fixed to the high-temperature section 10 by the fixing section 34 such as a double-faced adhesive tape.

Third Modification to Sixth Modification

FIGS. 6A to 6E illustrate appearances of the heat-dissipation members 30 according to a third modification to a sixth modification. A cross-sectional shape of the heat-dissipation member 30 (specifically, the cushion section 31) may be a circle illustrated in FIG. 6A, a rectangle illustrated in FIG. 6C, or the like in addition to the oval illustrated in FIG. 2 or an oval illustrated in FIG. 6B. A rectangular tube provided with a rectangle hole 31C in the center of a rectangle as illustrated in FIG. 6D, a cylinder provided with a square hole 31C in the center of a circle as illustrated in FIG. 6E, and the like may be adopted.
To improve heat transfer characteristics, it is effective to increase a contact area between the high-temperature section 10 and the heat-dissipation member 30 and a contact area between the low-temperature section 20 and the heat-dissipation member 30. Therefore, it is desirable that a pressure applied to the heat-dissipation member 30 be considered and the cushion section 31 be formed in the shape with which sizes of the foregoing contact areas become the largest when a predetermined pressure is applied. In these modifications, by adjusting the shape of the cushion section 31, a crushed amount due to a pressure and a shape after the heat-dissipation member 30 is crushed are controllable.
FIG. 7 illustrates shapes after the heat-dissipation members 30 (cushion sections 31) illustrated in FIGS. 6A to 6E are crushed. As can be seen from (A), (B), (E) of FIG. 7, in the case where the cross-sectional shape of the heat-dissipation member 30 is the oval, the circle, or the hollow circle, the crushed amounts thereof are allowed to be larger than that of the case in which the cross-sectional shape of the heat-dissipation member 30 is the rectangle. Further, in the case where (C) of FIG. 7 is compared to (D) of FIG. 7, it is found that in the case where the cross-sectional shape of the heat-dissipation member 30 is the hollow rectangle, the crushed amount thereof is allowed to be larger than that of the case in which the cross-sectional shape of the heat-dissipation member 30 is the solid rectangle.

Seventh Modification

FIG. 8 illustrates an appearance of the heat-dissipation member 30 according to a seventh modification. In this modification, a cross-sectional shape of the heat-dissipation member 30 (specifically, the cushion section 31) is I shape in which a notch 31D is provided on both side surfaces of a rectangle. In this modification, by adjusting the shape and the size of the notch 31D of the cushion section 31, a crushed amount due to a pressure and a shape after the heat-dissipation member 30 is crushed are controllable as in the third to the sixth modifications.

Application Examples

A description will be given of application examples of the heat-dissipation structure described in the foregoing embodiment. In a first application example, the heat-dissipation structure is provided in a backlight of a liquid crystal display. In a second application example, the heat-dissipation structure is provided on the rear side of a circuit board of a liquid crystal display.

[First Application]

FIG. 9 illustrates a configuration of a display unit (television unit) having the heat-dissipation structure illustrated in FIG. 1 seen from the front surface side. A display unit 1 has a configuration in which a main body section 2 formed of a liquid crystal display panel is supported by a stand 3.
FIG. 10 illustrates a cross-sectional configuration taken along a line X-X of FIG. 9. The display unit 1 has a front surface plate 41, a liquid crystal cell 42, an optical sheet 43, a reflecting member 44, a light guide plate 45, a heat source 46, a reflecting sheet 47, a heat spreader 48, and a back chassis 49 in this order when viewed from the front surface side (viewer side). The heat-dissipation member 30 according to the foregoing embodiment is arranged between the heat spreader 48 and the back chassis 49.
The front surface plate 41 is intended to secure strength of the liquid crystal cell 42, and is made of, for example, a glass plate. The optical sheet 43 includes a diffusion sheet, a luminance-enhancement film, or the like. The reflecting member 44 is a frame-like member (so-called a middle chassis) retaining the optical sheet 43 and the like, and is made of a resin with high reflectance such as white polycarbonate. The light guide plate 45 is made of, for example, acrylic (PMMA). The heat source 46 is made of a light emitting device such as an LED (light emitting device). The heat spreader 48 is made of, for example, aluminum (Al). The back chassis 49 is made of, for example, an aluminum (Al) plate.
The heat spreader 48 corresponds to a specific example of the high temperature section 10 according to the foregoing embodiment. Meanwhile, the back chassis 49 corresponds to a specific example of the low-temperature section 20 according to the foregoing embodiment.
Further, the heat source 46, the heat spreader 48, and the reflecting member 44 are fixed to the light guide plate 45, and slide according to expansion and shrinkage of the light guide plate 45. Therefore, the high-temperature section 10 slides in the direction of the arrow A3 along a borderline between the high-temperature section 10 and the low-temperature section 20. For example, the gap G being 0.2 mm to 0.3 mm both inclusive long is provided between the heat spreader 48 and the back chassis 49 to facilitate sliding.
The heat-dissipation member 30 is contained in, for example, a concave section 48A for arranging a heat-dissipation member provided in the heat spreader 48. Further, the heat-dissipation member 30 may be adhered to the bottom surface of the concave section 48A with the use of a double-faced adhesive tape (not illustrated) or the like in order to prevent dropping.
In the display unit, heat generated in the heat source 46 is firstly transferred to the heat spreader 48 (high-temperature section 10), and is subsequently dissipated from the heat spreader 48 (high-temperature section 10) to the back chassis 49 (low-temperature section 20) through the heat-dissipation member 30 as indicated by the arrows A1 and A2. In this case, contact between the heat-transfer section 32 and the heat spreader 48 (high-temperature section 10) and contact between the heat-transfer section 32 and the back chassis 49 (low-temperature section 20) are secured by the cushioning characteristics of the cushion section 31, and heat is transferred from the heat spreader 48 (high-temperature section 10) to the back chassis 49 (low-temperature section 20) through the heat-transfer section 32.
Further, in the case where the heat spreader 48 (high-temperature section 10) slides in the direction of the arrow A3, while the heat-dissipation member 30 slides along with the heat spreader 48 (high-temperature section 10), the heat-dissipation member 30 is in contact with both the heat spreader 48 (high-temperature section 10) and the back chassis (low-temperature section 20) and thereby promotes heat transfer. That is, contact between the heat-transfer section 32 and the heat spreader 48 (high-temperature section 10) and contact between the heat-transfer section 32 and the back chassis 49 (low-temperature section 20) are secured by the cushioning characteristics of the cushion section 31, and heat is transferred from the heat spreader 48 (high-temperature section 10) to the back chassis 49 (low-temperature section 20) through the heat-transfer section 32. Therefore, heat transfer and heat-dissipation are performed without inhibiting sliding characteristics of the heat spreader 48 (high-temperature section 10).

[Second Application]

FIG. 11 illustrates a configuration of a display unit (television unit) having the heat-dissipation structure illustrated in FIG. 1 seen from the rear surface side. The rear surface of a main body section 2 is covered with a rear cover 2A. Inside of the rear cover 2A, a circuit board 50 such as a power source substrate and a signal substrate is provided on the rear side of the back chassis 49 (see FIG. 10).
FIG. 12 illustrates a cross-sectional configuration taken along a line XII-XII of FIG. 11. An electronic part 51 such as an IC (integrated circuit) chip is mounted on the front surface (surface A) of the circuit board 50. The heat-dissipation member 30 according to the foregoing embodiment is arranged between the rear surface (surface B) of the circuit board 50 and the back chassis 49.
The circuit board 50 corresponds to a specific example of the high-temperature section 10 according to the foregoing embodiment. Meanwhile, the back chassis 49 corresponds to a specific example of the low-temperature section 20 according to the foregoing embodiment.
The circuit board 50 is fixed to the back chassis 49 by screws 52 at four corners as illustrated in FIG. 11, for example. Relative movement (sliding) of the high-temperature section 10 or the low-temperature section 20 is less likely to occur. The heat-dissipation member 30 may be adhered to the rear surface of the circuit board 50 or the back chassis 49 in a position directly under the electronic part 51 mounted on the circuit board 50 with the use of a double-faced adhesive tape (not illustrated) or the like to prevent dropping.
In the display unit, heat generated in the electronic part 51 is firstly transferred to the circuit board (high-temperature section 10), and is subsequently dissipated from the circuit board 50 (high-temperature section 10) to the back chassis 49 (low-temperature section 20) through the heat-dissipation member 30 as indicated by the arrows A1 and A2. In the case where the heat-dissipation member 30 does not exist, in a location distant from locations where the circuit board is fixed with the use of the screws 52, in some cases, a gap may be created, resulting in lowered heat transfer from the high-temperature section 10 to the low-temperature section 20. Meanwhile, the case where the heat-dissipation member 30 exists, contact between the heat-transfer section 32 and the circuit board 50 (high-temperature section 10) and contact between the heat-transfer section 32 and the back chassis 49 (low-temperature section 20) are secured by the cushioning characteristics of the cushion section 31, and heat is transferred from the circuit board 50 (high-temperature section 10) to the back chassis 49 (low-temperature section 20) through the heat-transfer section 32. Therefore, even in the case where a distance between the screws 52 and the electronic part 51 is large, contact area between the heat-dissipation member 30 and the circuit board 50 (high-temperature section 10) or the back chassis 49 (low-temperature section 20) is secured, and heat-dissipation efficiency is improved.

EXAMPLES

A description will be hereinafter given of specific examples according to the embodiment of the present disclosure.

Example 1

The heat-dissipation structure according to the foregoing embodiment was fabricated. First, as illustrated in FIG. 13, an LED 11 as a heat source was mounted on a light source substrate (not illustrated), the light source substrate was attached to a heat spreader (a cooling member of the light source substrate) 12, and thereby the high-temperature section 10 was formed. The heat value of the LED was about 7.2 W. Further, the low-temperature section 20 made of an aluminum plate was prepared.
Next, the cushion section 31 made of urethane with an oval cross section and the heat-transfer section 32 made of a graphite sheet were prepared. As the covering layer 33, a PET film being about 0.05 mm thick was adhered to the surface of the heat-transfer section 32 for adjusting contact resistance of the surface. The heat-transfer section 32 was wound around the cushion section 31, the heat-transfer section 32 was adhered to the cushion section 31 by using a double-faced adhesive tape (not illustrated), and thereby the heat-dissipation member 30 was formed (see FIG. 2).
After that, the high-temperature section 10 was arranged on the low-temperature section 20 made of an aluminum plate. At that time, as illustrated in FIG. 14, the heat-dissipation member 30 was inserted between the high-temperature section 10 and the low-temperature section 20. The high-temperature section 10, the low-temperature section 20, and the heat-dissipation member 30 were not fixed to each other. That is, the high-temperature section 10 was allowed to move (slide) along a borderline between the high-temperature section 10 and the low-temperature section 20 as indicated by the arrow A3.

Comparative Example 1

The heat-dissipation structure was fabricated as in Example 1, except that as illustrated in FIG. 15, a light source substrate mounted with an LED 111 was attached to a heat spreader 112 to form a high-temperature section 110, and a gap 140 being about 0.5 mm long was created between the high-temperature section 110 and a low-temperature section 120 by using an insulating member (not illustrated).

Comparative Example 2

The heat-dissipation structure was fabricated as in Example 1, except that as illustrated in FIG. 16, the high-temperature section 110 was fixed to the low-temperature section 120 by using a screw 150.

[Evaluation]

For the obtained heat-dissipation structures of Example 1 and Comparative examples 1 and 2, temperature and average temperature (unit: deg C for all cases) of six measurement points 1 to 6 were examined. Results thereof are illustrated in Table 1. The reduced ambient temperature was 25 deg C.

TABLE 1

Comparative example 1	Comparative example 2	Example 1
The gap was created	The high-temperature	The heat-dissipation member
between the high-	section was fixed to	was arranged between the
temperature section and	the low-temperature	high-temperature section
the low-temperature	section by the screw	and the low-temperature
section (FIG. 15).	(FIG. 16).	section (FIG. 14).

Measurement	55.6	43.8	42.7
point 1
Measurement	58.5	45.2	44.7
point 2
Measurement	59.6	45.6	45.1
point 3
Measurement	60.2	45.5	45.7
point 4
Measurement	58.7	44.8	44.1
point 5
Measurement	54.7	43.8	42.2
point 6
Average	57.9	44.8	44.1

As can be seen from Table 1, in Example 1 in which the heat-dissipation member 30 was inserted between the high-temperature section 10 and the low-temperature section 20, the average temperature was significantly lower than that of Comparative example 1 in which the gap was created between the high-temperature section 110 and the low-temperature section 120 for the following possible reason. That is, in Example 1, the heat-transfer section 32 was surely in contact with the high-temperature section 10 and the low-temperature section 20 by elasticity of the cushion section 31, and heat-transfer efficiency by the heat-transfer section 32 was improved.
Further, in Example 1, the average temperature was lower than that of Comparative example 2 in which the high-temperature section 110 was fixed to the low-temperature section 120 by using the screw 150 for the following possible reason. That is, a gap between the members with high rigidity, that is, between the members without cushioning characteristics was not perfectly eliminated even if such members were fixed to each other by using the screw. Therefore, heat transfer was lowered due to an air layer in between. In particular, in a location distant from locations where fixation was made by using the screw, the gap was more easily created, resulting in significant occurrence of lowered heat transfer. Meanwhile, in the case where the heat-dissipation member with cushioning characteristics was inserted between the high-temperature section and the low-temperature section, contact between the high-temperature section and the low-temperature section was more secured, heat transfer coefficient was improved, and accordingly higher heat-dissipation efficiency was shown than in the case of using the screw for fixation.
That is, it was found that in the case where the heat-dissipation member 30 included the cushion section 31 made of a flexible material and the heat-transfer section 32 that was provided in part or the entire surface of the cushion section 31 and was in contact with both the high-temperature section 10 and the low-temperature section 20, heat transfer efficiency due to the heat-transfer section 32 was allowed to be improved.
While the present disclosure has been described with reference to the embodiment and the examples, the present disclosure is not limited to the foregoing embodiment and the foregoing examples, and various modifications may be made. For example, in the foregoing embodiment, the description has been given of the case in which the heat-dissipation structure according to the embodiment of the present disclosure is applied to the display unit (television unit). However, the heat-dissipation structure according to the embodiment of the present disclosure is applicable to electronic devices in all fields including an electronic part or a light emitting device as a heat source such as a digital camera, a notebook personal computer, a mobile terminal such as a mobile phone, and a video camcorder in addition to the television unit.
Further, for example, the material, the thickness, and the like of each layer are not limited to those described in the foregoing embodiment, and other materials and other thicknesses may be adopted.
Further, for example, though in the foregoing embodiment, the description has been given of the configuration of the display unit (television unit) with the specific examples, all the components thereof are not necessarily included, and other components may be further included.
It is possible to achieve at least the following configurations from the above-described exemplary embodiment and the modifications of the technology.
(1) A heat-dissipation structure including:
a heat-dissipation member between a high-temperature section and a low-temperature section,
wherein the heat-dissipation member includes a cushion section being made of a flexible material, and
a heat-transfer section being provided in part or an entire surface of the cushion section, and being in contact with both the high-temperature section and the low-temperature section.
(2) The heat-dissipation structure according to (1), wherein one of the high-temperature section and the low-temperature section relatively moves with respect to the other one of the high-temperature section and the low-temperature section.
(3) The heat-dissipation structure according to (2), wherein a covering layer decreasing a surface friction resistance is provided on a surface of the heat-transfer section.
(4) The heat-dissipation structure according to any one of (1) to (3), wherein the cushion section is made of a material with both cushioning characteristics and heat conductivity.
(5) The heat-dissipation structure according to any one of (1) to (4),
wherein two cushion sections are provided, and
the heat-transfer section is provided in the shape of S between a surface on the high-temperature section side of a first cushion section and a surface on the low-temperature section side of a second cushion section.
(6) The heat-dissipation structure according to any one of (1) to (4), wherein a first end of the heat-transfer section covers a surface on one of the high-temperature section side and the low-temperature section side of the cushion section, and
a second end of the heat-transfer section is fixed to the other one of the high-temperature section and the low-temperature section.
(7) A display unit including:
a heat-dissipation member between a high-temperature section including a display device and a low-temperature section,
wherein the heat-dissipation member includes a cushion section being made of a flexible material, and
a heat-transfer section being provided in part or an entire surface of the cushion section, and being in contact with both the high-temperature section and the low-temperature section.
It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and alternations may occur depending on design requirements and other factors insofar as they are within the scope of the appended claims or the equivalents thereof.

Claims

1. A heat-dissipation structure comprising:

a heat-dissipation member between a high-temperature section and a low-temperature section,

wherein the heat-dissipation member includes

a cushion section being made of a flexible material, and

a heat-transfer section being provided in part or an entire surface of the cushion section, and being in contact with both the high-temperature section and the low-temperature section.

2. The heat-dissipation structure according to claim 1, wherein one of the high-temperature section and the low-temperature section relatively moves with respect to the other one of the high-temperature section and the low-temperature section.

3. The heat-dissipation structure according to claim 2, wherein a covering layer decreasing a surface friction resistance is provided on a surface of the heat-transfer section.

4. The heat-dissipation structure according to claim 1, wherein the cushion section is made of a material with both cushioning characteristics and heat conductivity.

5. The heat-dissipation structure according to claim 1,

wherein two cushion sections are provided, and

the heat-transfer section is provided in the shape of S between a surface on the high-temperature section side of a first cushion section and a surface on the low-temperature section side of a second cushion section.

6. The heat-dissipation structure according to claim 1, wherein a first end of the heat-transfer section covers a surface on one of the high-temperature section side and the low-temperature section side of the cushion section, and

a second end of the heat-transfer section is fixed to the other one of the high-temperature section and the low-temperature section.

7. A display unit comprising:

a heat-dissipation member between a high-temperature section including a display device and a low-temperature section,

wherein the heat-dissipation member includes

a cushion section being made of a flexible material, and