Heat dissipation device and heat sink

Abstract

To provide a heat radiator and a heat sink capable of suppressing the enlargement of a device and improving heat radiation performance.SOLUTION: A heat radiator includes a heat sink 12 including a heat absorbing surface 12a provided on one surface and absorbing heat emitted from an electronic component 4, and a heat emitting surface 12b provided on the other surface and emitting at least a part of the heat absorbed from the heat absorbing surface 12a as electromagnetic waves, and the heat sink 12 is made of a member containing silicon and has a size of 150 μm or more in the thickness direction.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a heat dissipation device and a heat dissipation plate that absorb and release heat generated in a heat generating body such as an electronic component.

Background Art

[0002] Conventional heat dissipation devices include, for example, fin-type heat sinks, which are attached to the outer surface of a heat generating body such as an electronic component, and the heat of the heat generating body is transmitted to the heat sink, and the heat is released from the fins to the atmosphere, or the air between the fins is forced to convection using a blower and released to the atmosphere (for example, see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Since conventional heat dissipation devices dissipate heat using heat conduction, it is necessary to provide a component with a low temperature such as a heat sink, and there is a risk that the device will become larger.

[0005] An object of the present invention is to provide a heat dissipation device and a heat dissipation plate that can suppress the enlargement of the device and improve the heat dissipation performance.

Means for Solving the Problems

[0006] The heat dissipation device according to the present invention includes a heat dissipation plate provided with a heat absorption surface on one surface for absorbing heat released from a heat source and a heat release surface on the other surface for releasing at least a part of the heat absorbed from the heat absorption surface as electromagnetic waves, the heat dissipation plate is made of a member containing silicon, and the size in the thickness direction is 150 μm or more.

[0007] Furthermore, the heat sink according to the present invention is a heat sink having a heat absorbing surface provided on one side that absorbs heat emitted from a heat source, and a heat emitting surface provided on the other side that emits at least a portion of the heat absorbed from the heat absorbing surface as electromagnetic waves, and is made of a silicon-containing material and has a thickness of 150 μm or more. [Effects of the Invention]

[0008] According to the present invention, by using a heat sink containing silicon with a thickness of 150 μm or more, it is possible to increase the amount of heat dissipated by thermal radiation from the heat sink, thereby suppressing the increase in the size of the device and improving the heat dissipation performance. Furthermore, according to the present invention, it is possible to configure the functions of a heat absorption surface and a heat release surface with a single silicon component, thereby simplifying the manufacturing process. [Brief explanation of the drawing]

[0009] [Figure 1] This is a cross-sectional view of an electronic device to which a heat dissipation device according to one embodiment of the present invention is applied. [Figure 2] This is a cross-sectional view illustrating a test method for evaluating the performance of a heat dissipation device according to one embodiment of the present invention. [Figure 3] This graph shows the results of a test evaluating the performance of a heat dissipation device according to one embodiment of the present invention. [Modes for carrying out the invention]

[0010] Figures 1 to 3 illustrate one embodiment of the present invention. Figure 1 is a cross-sectional view of an electronic device to which a heat dissipation device is applied, Figure 2 is a cross-sectional view illustrating a test method for evaluating the performance of the heat dissipation device, and Figure 3 is a graph showing the results of a test to evaluate the performance of the heat dissipation device.

[0011] As shown in Figure 1, the heat dissipation device 10 of this embodiment is applied to the electronic device 1.

[0012] The electronic device 1 comprises a housing 2, a circuit board 3 mounted inside the housing 2, an electronic component 4 as a heat source mounted on the circuit board 3, and a heat dissipation device 10 according to the present invention mounted on the electronic component 4.

[0013] Electronic component 4 is, for example, a CPU (Central Processing Unit) that releases heat during operation.

[0014] The heat dissipation device 10 includes a heat conductive material 11 for transferring heat emitted from the electronic component 4 to a heat sink plate described later, and a heat sink plate 12 for releasing the heat transmitted from the electronic component 4 through the heat conductive material 11 by thermal radiation.

[0015] The thermal conductive material 11 is exemplified by, but is not limited to, a sheet-like member made of a resin with fillers such as alumina, silicon nitride, or aluminum nitride added, a metal substrate such as alumina, silicon nitride, or aluminum nitride, or thermal conductive grease. Furthermore, the thermal conductive material 11 is exemplified by, but is not limited to, a material attached to the outer surface of the electronic component 4. The thermal conductive material 11 can take any form as long as it uniformly conducts the heat emitted from the electronic component 4 across the entire surface of the heat sink 12. In particular, when the heat absorption surface 12a side of the heat sink 12, described later, is planar, it is preferable that the thermal conductive material 11 can transfer the heat emitted from the electronic component 4 to the heat sink 12 regardless of the outer surface shape of the electronic component 4, and is preferably in the form of grease, paste, or gel.

[0016] The heat sink 12 is a plate-shaped member made of silicon with a thickness t of 150 μm or more. The heat sink 12 has a heat absorption surface 12a on one side for absorbing heat emitted from the electronic component 4, and a heat emission surface 12b on the other side for emitting at least a portion of the heat absorbed from the heat absorption surface 12a as electromagnetic waves.

[0017] The heat absorption surface 12a of the heat sink 12 is in contact with the heat conductive material 11 over the entire surface. Also, the heat dissipation surface 12b of the heat sink 12 faces the inner surface of the housing 2 with a gap therebetween.

[0018] In the electronic device 1 configured as described above, part of the heat released from the electronic component 4 is transmitted to the housing 2 through the substrate 3 by heat conduction, and the other heat released from the electronic component 4 is transmitted to the housing 2 through the heat dissipation device 10 by heat radiation and convection. The heat transmitted to the housing 2 is released into the air outside the housing 2.

[0019] Also, the heat transmitted from the electronic component 4 to the heat dissipation device 10 is absorbed by the heat sink 12 from the entire surface of the heat absorption surface 12a. Also, at least part of the heat absorbed by the heat sink 12 is released as electromagnetic waves from the entire surface of the heat dissipation surface 12b by heat radiation and transmitted to the inner surface of the housing 2.

[0020] Here, the results of tests for evaluating the heat dissipation performance of each of a plurality of types of heat dissipation devices 10 having heat sinks 12 with different thicknesses t in the thickness direction will be described.

[0021] First, the test for evaluating the heat dissipation performance uses the test device 100 shown in FIG. 2. The test device 100 includes an aluminum box 110, a rubber heater 120 housed inside the box 110 and having a planar heat dissipation surface made of silicon rubber, a heat insulating member 130 covering one surface of the rubber heater 120, and a temperature sensor 140 for detecting the temperature of the rubber heater 120. The test for evaluating the heat dissipation performance is performed by installing the heat dissipation device 10 to be tested on the other surface side of the rubber heater 120 inside the box 110 and detecting the change in temperature with the passage of time after starting the energization of the rubber heater 120 by the temperature sensor 140.

[0022] Next, the results of the test for evaluating the heat dissipation performance of the heat dissipation device 10 by the test device 100 will be described using the graph of FIG. 3.

[0023] First, the change in temperature of the rubber heater 120 over time when the heat dissipation device 10 is not installed in the test device 100 is represented by a solid line. Also, the change in temperature of the rubber heater 120 over time when each of a plurality of types of heat dissipation devices 10 is installed is represented by a line type other than the solid line.

[0024] From this, it can be seen that when the heat dissipation device 10 is installed in the test device 100, the degree of temperature rise of the rubber heater 120 is smaller compared to the change in temperature of the rubber heater 120 when the heat dissipation device 10 is not installed. That is, the temperature of the rubber heater 120 is maintained at a low level because the heat emitted from the rubber heater 120 is dissipated through the heat dissipation device 10.

[0025] Also, it can be seen that the degree of temperature rise (dashed line in FIG. 3) of the heat dissipation device 10 having the heat dissipation plate 12 with a thickness direction size t of 100 μm is larger than the degree of temperature rise (two-dot chain line, one-dot chain line, dotted line in FIG. 3) of the heat dissipation devices 10 having the heat dissipation plates 12 with thickness direction sizes t of 200 μm, 400 μm, and 725 μm. That is, the heat dissipation device 10 having the heat dissipation plate 12 with a thickness direction size t of 100 μm has a smaller heat dissipation amount compared to the heat dissipation devices 10 having the heat dissipation plates 12 with thickness direction sizes t of 200 μm, 400 μm, and 725 μm.

[0026] Based on the curve of the temperature change of the heat dissipation plate 12 with each thickness direction size t in FIG. 3, it can be determined that the heat dissipation plate 12 has an effective heat dissipation effect when the thickness direction size t is 150 μm or more.

[0027] Thus, according to the heat dissipation device 10 of the present embodiment, there is provided a heat dissipation plate 12 having a heat absorption surface 12a provided on one surface for absorbing heat emitted from the electronic component 4, and a heat radiation surface 12b provided on the other surface for emitting at least a part of the heat absorbed from the heat absorption surface 12a as electromagnetic waves. The heat dissipation plate 12 is made of a member containing silicon and has a thickness direction size t of 150 μm or more.

[0028] Furthermore, the heat sink 12 of this embodiment has a heat absorbing surface 12a provided on one side that absorbs heat emitted from the electronic component 4, and a heat emitting surface 12b provided on the other side that emits at least a portion of the heat absorbed from the heat absorbing surface 12a as electromagnetic waves, and is made of a silicon-containing material and has a thickness of 150 μm or more.

[0029] As a result, by using a heat sink 12 containing silicon with a thickness t of 150 μm or more, it becomes possible to increase the amount of heat released by thermal radiation from the heat dissipation surface 12b of the heat sink 12, thereby suppressing the increase in the size of the device and improving the heat dissipation performance.

[0030] In the above embodiment, a heat sink 12 made of silicon was shown, but the same effects as in the above embodiment can be obtained even if the heat sink is made of, for example, single-crystal silicon, polycrystalline silicon, or a silicon-based material containing other materials. Furthermore, by forming the heat sink from a single silicon-based material, it is possible to configure both the heat absorption function and the heat release function with a single material. This simplifies the manufacturing process of the heat sink, stabilizes the quality of the heat sink, and reduces manufacturing costs.

[0031] Furthermore, although the above embodiment shows a heat dissipation device 10 having a heat conductive material 11 and a heat sink 12, the heat dissipation device may have components other than the heat conductive material 11, as long as it has the heat sink 12 of the present invention.

[0032] Furthermore, although the above embodiment describes a heat dissipation device 10 having a heat conductive material 11 and a heat sink 12 installed on an electronic component, it is not limited to this. For example, the heat sink alone may be installed on the electronic component without the heat conductive material 11, so that its heat-absorbing surface is in direct contact with the electronic component. In this case, the heat emitted from the electronic component will be absorbed directly from the heat-absorbing surface of the heat sink. [Explanation of symbols]

[0033] 4 Electronic components 10. Heat dissipation device 12 Heat dissipation plates 12a heat absorption surface 12b heat release surface

Claims

[Claim 1] A heat dissipation plate is provided, having a heat absorbing surface on one side that absorbs heat emitted from a heat source, and a heat emitting surface on the other side that emits at least a portion of the heat absorbed from the heat absorbing surface as electromagnetic waves. The aforementioned heat sink is It consists of a component containing silicon, The size in the thickness direction is 150 μm or more. The heat dissipation surface faces the inner surface of the housing that constitutes the electronic device, The electromagnetic waves emitted from the heat dissipation surface are transmitted to the inner surface of the housing. Heat dissipation device.

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