WO2013105138A1

WO2013105138A1 - Heat dissipation structure

Info

Publication number: WO2013105138A1
Application number: PCT/JP2012/000185
Authority: WO
Inventors: 愼一篠原; 和宏松原
Original assignee: パナソニック株式会社
Priority date: 2012-01-13
Filing date: 2012-01-13
Publication date: 2013-07-18

Abstract

This heat dissipation structure is provided with a heat dissipation plate (6) that is arranged between a heat generating component (4) and an outer shell member (2). The heat dissipation plate (6) comprises: a first surface portion (61) that extends along the main surface of the heat generating component (4); a linking portion (62) that rises from the edge of the first surface portion (61); and a second surface portion (63) that extends from the front edge of the linking portion (62) along the outer shell member (2) in the direction opposite to the first surface portion (61). Heat is transmitted to the first surface portion (61) from the heat generating component (4), and the second surface portion (63) transmits the heat, which has been transmitted thereto from the first surface portion (61) through the linking portion (62), to the outer shell member (2).

Description

Heat dissipation structure

The present invention relates to a heat dissipating structure for releasing heat of a heat generating component arranged in a housing, for example.

In recent years, downsizing of electronic devices and integration of electronic components are progressing. With the downsizing of electronic devices and the integration of electronic components, heat dissipation measures for electronic components used in electronic devices become important. In general, the smaller the electronic device, the smaller the heat dissipation space and the higher the integration of electronic components.

Conventionally, various heat dissipation structures for electronic parts have been proposed. For example, Patent Document 1 discloses a heat dissipation structure 100 as shown in FIG. In the heat dissipation structure 100, electronic components 120 of different sizes mounted on the circuit board 110 are brought into contact with the shield cover 150 via the heat conducting member 130.

US Pat. No. 7,808,572

However, in the heat dissipation structure 100 shown in FIG. 7, the heat of the heat generating component 120 is directly transmitted to the shield cover 150, and thus the shield cover 150 may locally become hot.

An object of the present invention is to provide a heat dissipation structure capable of suppressing the outer shell member from locally becoming high temperature.

In order to solve the above problems, a heat dissipation structure according to the present invention includes a circuit board, a heat generating component mounted on the circuit board and having a flat main surface, and an external cover that covers the circuit board apart from the heat generating component. A heat sink disposed between a shell member, the heat generating component, and the outer member, and a first surface portion that transmits heat from the heat generating component along the main surface of the heat generating component, the first surface portion A connecting portion that rises from the edge of the outer shell member so as to approach the outer shell member, and extends from the front end of the connecting portion along the outer shell member to the side opposite to the first surface portion, from the first surface portion via the connecting portion. And a heat radiating plate having a second surface portion for transmitting heat to be conducted to the outer shell member.

According to said structure, since the space which faces the connection part of a heat sink is ensured between the 1st surface part of a heat sink along an exothermic component, and an outer shell member, the heat | fever of a heat generating component is the inside of a heat sink. Is radiated (radiated) into the space from the first surface portion and the connecting portion. Therefore, the heat transmitted from the second surface portion of the heat radiating plate to the outer shell member can be reduced, and the outer shell member can be prevented from becoming locally hot.

The perspective view from the front of the display apparatus with which the heat dissipation structure which concerns on one Embodiment of this invention was employ | adopted. The perspective view from the back of the display apparatus shown in FIG. The perspective view from the back which shows a part of display apparatus shown in FIG. 1 in a cross section Circuit board perspective view Sectional drawing of the display apparatus along the VV line in FIG. 6A and 6B are sectional views showing a heat dissipation structure of a modification. Cross section of conventional heat dissipation structure

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiments.

1 to 3 show a display device 1 employing a heat dissipation structure 10 (see FIG. 3) according to an embodiment of the present invention. Specific examples of the display device 1 include a television receiver and an outdoor display.

The display device 1 includes a display panel 11 that displays an image according to a signal input from the outside, a bezel 12 that borders the periphery of the display panel 11, and a back cover that covers the back surface of the display panel 11 (the outer shell member of the present invention). 2). The display panel 11 is a liquid crystal panel, for example. In the present embodiment, the screen of the display panel 11 faces the horizontal direction.

For example, the bezel 12 is made of resin, and a steel plate is used as a material constituting the back cover 2. The material which comprises the back cover 2 should just have sufficient thermal radiation performance as the exterior of an electronic device, and is not limited to a steel plate. However, it is preferable to use a steel plate from the viewpoint of low cost and easy processing. Of course, other metals with high radiation performance can also be used.

Specifically, the back cover 2 has a horizontally long rectangular main wall 21 parallel to the back surface of the display panel 11, an upper wall 22 that is bent obliquely from the upper side of the main wall 21, and a lower wall that is bent vertically from the lower side of the main wall 21. The wall 23 and the side wall 24 bent vertically from the left and right sides of the main wall 21 are provided.

The main wall 21 of the back cover 2 is formed with a heat radiation port 25 composed of a plurality of through holes. The heat radiation port 25 is for directly releasing the heat inside the display device 1 to the outside air. In addition, although illustration is abbreviate | omitted, in the back cover 2, the ventilation port which consists of a some through-hole may be formed in the upper direction or the downward direction of the thermal radiation port 25. FIG. Thereby, the cooling function can be enhanced by the flow of air through the heat radiation port 25. For example, a vent hole may be provided in the upper wall 22 or the lower wall 23 of the back cover 2. When the vent is formed below the heat radiation port 25, the vent functions as an intake port, and the outside air taken in from the vent is discharged from the heat radiation port 25. This is because heat convection occurs. On the contrary, when the vent is formed above the heat radiation port 25, the vent functions as an exhaust port, and the outside air taken in from the heat radiation port 25 is discharged from the vent.

Next, details of the heat dissipation structure 10 will be described with reference to FIGS. The heat dissipation structure 10 is a structure that releases heat generated inside the display device 1 to the outside through the back cover 2. In FIG. 4, the back cover 2 is omitted in order to clarify the internal structure.

The circuit board 3 is attached to the back surface of the display panel 11 in parallel with the back surface. In other words, the circuit board 3 is parallel to the vertical direction. A heat generating component 4 is mounted on the surface of the circuit board 3 facing the back cover 2 side. The back cover 2 is separated from the heat generating component 4 and covers the circuit board 3.

The circuit board 3 is a board on which components for controlling signals output to the display panel 11 are mounted. There are various parts that control the output signal, and there are parts that become hot during operation. This component is the heat generating component 4. Heat generated by the heat generating component 4 is radiated by the heat radiating structure 10.

The heat generating component 4 is, for example, a semiconductor chip. A semiconductor chip has a package structure in which a large number of circuits are integrated. The main surface of the heat generating component 4 facing away from the circuit board 3 is flat, and the manufacturer name and product number are printed on the main surface. The heat generating component 4 generates heat during the operation of the display device 1 and reaches, for example, 100 degrees or more.

A heat sink 6 is disposed between the heat generating component 4 and the back cover 2. The heat radiating plate 6 constitutes a heat radiating structure 10 together with the circuit board 3, the heat generating component 4 and the back cover 2.

The heat sink 6 receives heat from the heat generating component 4, radiates a part of the heat, and transmits the rest to the back cover 2. For example, an aluminum plate is used as a material constituting the heat radiating plate 6. Aluminum is suitable for the heat sink 6 because of its high radiation performance and high thermal conductivity. However, depending on the amount of heat generated by the heat-generating component, other metals can be substituted. The heat sink 6 is fixed to the back cover 2 with screws 9.

In the present embodiment, the heat radiating plate 6 is formed in a shape that forms a groove extending in the vertical direction by bending an aluminum plate having a certain thickness. However, the direction in which the groove extends is not necessarily a vertical direction, and may be a horizontal direction or an oblique direction. Specifically, the heat radiating plate 6 includes a first surface portion 61 located right above the heat generating component 4, and a connecting portion 62 and a second surface portion 63 located on both sides of the first surface portion 61. Thus, if a plurality of connecting portions 62 and second surface portions 63 are provided so as to form a pair with the first surface portion 61 interposed therebetween, the balance at the time of assembly is improved, and the pressure applied to the first surface portion 61 is easily dispersed. Become.

The first surface portion 61 is a portion along the main surface of the heat generating component 4 where heat is transmitted from the heat generating component 4. In the present embodiment, the first surface portion 61 has a size larger than the main surface of the heat generating component 4, and the first surface portion 61 protrudes around the heat generating component 4. The size of the first surface portion 61 is preferably 1.5 times or more of the main surface of the heat generating component 4, and more preferably 2 times or more. The heat radiation port 25 described above is formed in a region facing the first surface portion 61 in the main wall 21 of the back cover 2. However, the size of the first surface portion 61 may be smaller than the size of the main surface of the heat generating component 4 as shown in FIG. 6A.

In the present embodiment, a heat conductive member 5 having elasticity is sandwiched between the first surface portion 61 and the heat generating component 4, and the first surface portion 61 contacts the heat generating component 4 via the heat conductive member 5. ing. As the heat conductive member 5, for example, rubber having high heat conductivity can be used.

The connecting portion 62 rises from the left and right edges of the first surface portion 61 so as to approach the back cover 2 and integrally connects the first surface portion 61 and the second surface portion 63. In the present embodiment, the connecting portion 62 rises at an obtuse angle with respect to the first surface portion 61. However, the connecting portion 62 may rise at a right angle to the first surface portion 61 as shown in FIG. 6A, or may rise at an acute angle with respect to the first surface portion 61 as shown in FIG. 6B.

The second surface portion 63 extends from the tip of the connecting portion 62 to the opposite side of the first surface portion 61 along the back cover 2. The second surface portion 63 plays a role of transmitting heat conducted from the first surface portion 61 through the connecting portion 62 to the back cover 2. When there are a plurality of second surface portions 63 as in the present embodiment, the number of locations where heat is transmitted increases, so that the heat of the heat generating component 4 can be efficiently radiated.

In the present embodiment, a heat conductive member 7 having elasticity is sandwiched between each second surface portion 63 and the back cover 2, and the second surface portion 63 contacts the back cover 2 via the heat conductive member 7. is doing. As the heat conductive member 7, as with the heat conductive member 5, for example, rubber having high heat conductivity can be used.

The second surface portion 63 is provided with a fixing portion 64 (see FIG. 4) having an L-shaped cross section that protrudes vertically. A screw hole is provided in the center of each fixing portion 64, and the second surface portion 63 is fastened to the back cover 2 by screwing the screw 9 into the screw hole through a through hole provided in the back cover 2. .

In the present embodiment, as described above, the first surface portion 61 projects around the heat generating component 4 and the connecting portion 62 rises at an obtuse angle with respect to the first surface portion 61, so that it is orthogonal to the main surface of the heat generating component 4. The second surface portion 63 is located outside the heat generating component 4 when viewed from the direction of the heating. However, the heat of the heat generating component 4 is diffused even when the size of the first surface portion 61 is smaller than the main surface of the heat generating component 4 or when the connecting portion 62 rises at a right angle or an acute angle with respect to the first surface portion 61. From the viewpoint, it is preferable that the second surface portion 63 is located outside the heat generating component 4 when viewed from a direction orthogonal to the main surface of the heat generating component 4.

Next, how the heat generated from the heat generating component 4 in the display device 1 is radiated by the heat dissipation structure 10 described above will be described. The heat dissipation phenomenon performed by the heat dissipation structure 10 is explained by heat radiation, heat conduction, and heat transfer. Each will be described below.

(Thermal radiation)
The heat generated from the heat generating component 4 is transmitted to the first surface portion 61 via the heat transfer rubber 5. The heat accumulated in the first surface portion 61 is not only radiated to the space surrounded by the first surface portion 61, the connecting portion 62, and the back cover 2, but is also released directly from the heat radiation port 25 to the outside air by heat radiation. The Therefore, heat radiation is efficiently performed by the heat radiation port 25.

In the present embodiment, the heat radiation port 25 is formed in the back cover 2, but the present invention is not limited to this. Even if the heat radiation port 25 is not formed, the heat radiated from the first surface portion 61 is transmitted to the back cover 2 and radiated from the back cover 2 over time. Thereby, sufficient heat dissipation performance can be satisfied.

Depending on the amount of heat generated by the heat generating component 4, sufficient heat dissipation can be achieved even if the first surface portion 61 is brought close to or directly in contact with the heat generating component 4 without using the heat conductive member 5. However, when the heat conductive member 5 is interposed as in the present embodiment, the contact area between the heat generating component 4 and the heat radiating plate 6 rather than the first surface portion 61 that is a metal directly contacting the heat generating component 4. Can be increased. Therefore, the heat of the heat generating component 4 can be efficiently transmitted to the first surface portion 61. As a result, the amount of heat radiated from the first surface portion 61 increases.

(Heat conduction)
The heat sink 6 has a configuration in which the first surface portion 61, the connecting portion 62, and the second surface portion 63 are continuous. As described above, the heat of the heat generating component 4 is transmitted to the first surface portion 61. The heat transmitted to the first surface portion 61 moves to the second surface portion 63 via the connecting portion 62 by heat conduction. Also during this time, the heat of the heat generating component 4 is radiated from the connecting portion 62 to the space surrounded by the first surface portion 61, the connecting portion 62, and the back cover 2.

In the present embodiment, the connecting portion 62 rises at an obtuse angle with respect to the first surface portion 61. That is, the connecting part 62 extends outward from the first surface part 61. In this configuration, since the amount of composition breakdown inside the heat sink 6 (cracks generated inside the heat sink 6) is small at the corners of the first surface portion 61 and the connecting portion 62, the heat conductivity of the heat sink 6 itself is lowered. Can be prevented. Further, there is an effect that the thermal radiation of the first surface portion 61 is not inhibited. Furthermore, when the connecting portion 62 spreads outward from the first surface portion 61, the stress applied to the back cover 2 by the heat radiating plate 6 can be reduced.

Further, since the second surface portion 63 is parallel to the first surface portion 61, the second surface portion 63 also forms an obtuse angle with respect to the connecting portion 62. That is, in this embodiment, the amount of composition breakdown inside the heat sink 6 is small even at the corners of the connecting portion 62 and the second surface portion 63, and a decrease in the thermal conductivity of the heat sink 6 itself can be prevented.

(Heat transfer)
As described above, heat corresponding to the heat of the heat-generating component 4 excluding the heat radiated from the heat of the heat generating component 4 reaches the second surface portion 63. The heat of the second surface portion 63 is transmitted to the back cover 2 via the heat conductive member 7.

Depending on the amount of heat generated by the heat generating component 4, heat can be sufficiently radiated even if the second surface portion 63 is brought close to or directly in contact with the back cover 2 without using the heat conductive member 7. However, when the heat conductive member 7 is interposed as in the present embodiment, the contact between the back cover 2 and the second surface portion 63 rather than the metal second surface portion 63 directly contacting the back cover 2. The area can be increased. Therefore, the heat of the second surface portion 63 can be efficiently transmitted to the back cover 2. As a result, the amount of heat transferred from the second surface portion 63 to the back cover 2 increases. Further, when the heat conductive member 7 is interposed as in the present embodiment, the tolerance generated between the back cover 2 and the heat sink 6 can be absorbed by the expansion / contraction width of the heat conductive member 7. As a result, the possibility that a gap is generated between the back cover 2 and the heat sink 6 can be reduced.

Further, in the present embodiment, the second surface portion 63 is fastened to the back cover 2. If it does in this way, when the heat conductive member 7 is pinched | interposed between the 2nd surface part 63 and the back cover 2, the usage-amount of the said heat conductive member 7 can be reduced. This is because the distance between the second surface portion 63 and the back cover 2 can be arbitrarily adjusted by adjusting the degree of fastening. Even when the heat conductive member 7 is not sandwiched between the second surface portion 63 and the back cover 2, the back cover 2 and the second surface portion 63 can be fixed in the proximity or in contact with each other. . Parts used for fastening can be selected as appropriate, and a clamper, a rivet or the like can be used in addition to the screw 9.

<Modification>
In the embodiment, two connecting portions 62 and two second surface portions 63 are provided, but these may be provided one by one, or may be provided by three or more.

In the embodiment, the heat sink 6 is manufactured by bending an aluminum plate having a constant thickness, but the heat sink 6 may be manufactured by extrusion molding. In this case, it is also possible to form irregularities for improving the radiation performance on the surface of the first surface portion 61 opposite to the heat generating component 4.

The heat dissipating structure of the present invention is useful as a structure for dissipating heat in a housing such as a flat-screen television or an outdoor display.

Claims

A circuit board;
A heat-generating component having a flat main surface mounted on the circuit board;
An outer shell member that is spaced apart from the heat generating component and covers the circuit board;
A heat radiating plate disposed between the heat generating component and the outer member, the first surface portion along which the heat is transmitted from the heat generating component along the main surface of the heat generating component, from the edge of the first surface portion A connecting portion that rises so as to approach the outer shell member, and heat conducted from the first surface portion through the connecting portion that spreads from the tip of the connecting portion along the outer shell member to the side opposite to the first surface portion. A heat sink having a second surface portion for transmitting to the outer shell member;
With heat dissipation structure.
The heat dissipation structure according to claim 1, wherein the second surface portion is located outside the heat generating component when viewed from a direction orthogonal to the main surface of the heat generating component.
The heat dissipation structure according to claim 1, wherein the first surface portion projects around the heat generating component.
2. The heat dissipation structure according to claim 1, wherein a plurality of the connection portions and the second surface portions are provided so as to form a pair with the first surface portion interposed therebetween.
The heat dissipation structure according to claim 1, wherein the connecting portion rises at an obtuse angle with respect to the first surface portion.
The heat dissipation structure according to claim 1, further comprising a heat conductive member having elasticity sandwiched between the first surface portion and the heat generating component.
The heat dissipation structure according to claim 1, further comprising an elastic heat conductive member sandwiched between the second surface portion and the outer shell member.
The heat dissipation structure according to claim 1, wherein the second surface portion is fastened to the outer shell member.
The heat dissipation structure according to claim 1, wherein a heat radiation port including a plurality of through holes is formed in a region of the outer shell member facing the first surface portion.
The circuit board is parallel to the vertical direction,
The heat dissipation structure according to claim 9, wherein the outer shell member has an intake port formed below the thermal radiation port or an exhaust port formed above the thermal radiation port.
A display panel for displaying images;
The heat dissipation structure according to claim 1, wherein the outer shell part is a back cover that covers a back surface of the display panel.