JP2008098397A - Heat exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat exchanger which expands its heat exchanging area when the temperature of a portion to be cooled goes up or the temperature of a portion to be heated goes down. <P>SOLUTION: The heat exchanger comprises a heat dissipation layer 10 formed of such a material that may bend when the temperature changes and may come back to its original shape when the temperature gets back; a bonding layer 20 which is formed on a first face of the heat dissipation layer 10 to fix the heat dissipation layer 10 to other object (for example, heat sink); a non-bonding region 22 which is a part of the dissipation layer 10 not formed with the bonding layer 20 on the first face; and a thermal deformation portion 12 formed by separating the edge of the non-bonding region 22 except for a part from the main body of the heat dissipation layer 10. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a heat exchange device that cools or heats an object. In particular, the present invention relates to a heat exchange device that increases the heat exchange area when the temperature of a portion to be cooled increases or when the temperature of a portion to be heated decreases.

  For example, an electronic component using a semiconductor device needs to keep the temperature of the electronic component within a predetermined range in order to obtain performance as designed. Since the electronic component generates heat during operation, it is necessary to cool the electronic component in order to keep the temperature of the electronic component during operation below the upper limit. In order to increase the cooling efficiency of the electronic component, a heat sink is generally attached to the electronic component.

  On the other hand, in Patent Document 1, a piezoelectric element covered with a rubber sheet is arranged inside a housing, and the expansion and contraction of the rubber sheet is repeated by vibration generated when a voltage is applied to the piezoelectric element. A technique is disclosed in which air enters and exits from the vent of the casing to increase the cooling efficiency inside the casing.

Japanese Patent Laid-Open No. 11-145661 (FIG. 1)

  For example, consider the operation of an electronic component. Considering that there is a possibility that abnormal load is generated on the electronic component and abnormal heat generation may occur, it is better that the heat transfer capability of the heat sink is large. However, if the heat transfer capability of the heat sink is too large, for example, the temperature of the electronic component does not rise sufficiently during normal operation in a cold region, and the electronic component may not exhibit the designed capability.

  The present invention has been made in view of the above circumstances, and its purpose is to perform heat exchange when the temperature of the portion to be cooled increases or when the temperature of the portion to be heated decreases. An object of the present invention is to provide a heat exchange device having a large area.

In order to solve the above problems, the first heat exchange device according to the present invention is formed of a material that bends in the first surface direction when the temperature changes and returns to its original shape when the temperature returns. Heat dissipation layer,
A bonding layer provided on the second surface of the heat dissipation layer and fixing the heat dissipation layer to another object;
A non-joint region which is a part of the heat dissipation layer and is not provided with the joining layer on the second surface;
And a thermal deformation portion formed by separating the peripheral edge portion of the non-joining region from the main body of the heat dissipation layer except for a part thereof.

  The heat dissipation layer is formed of, for example, a shape memory alloy or a bimetal obtained by stacking two metal layers having different thermal expansion coefficients.

A second heat exchange device according to the present invention includes a heat dissipation layer,
It is formed of a material that bends in the direction of the first surface when the temperature changes and returns to its original shape when the temperature returns, and a part of the second surface can conduct heat to the heat dissipation layer. A heat-deformed portion fixed in a state.

  The thermally deformable portion is formed of, for example, a shape memory alloy or a bimetal in which two metal layers having different coefficients of thermal expansion are stacked.

  According to the present invention, when the temperature of an object to be cooled or heated is less than a certain value or more than a certain value, heat exchange is performed only on the first surface in the heat deformable portion, but the object to be cooled or heated. When the temperature of the object is equal to or higher than a certain value or less than a certain value, the thermal deformation portion is deformed, and heat exchange is performed on both the first and second surfaces. Therefore, when the temperature of the part to be cooled increases or when the temperature of the part to be heated decreases, the heat exchange area increases.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1A is a plan view of a heat exchange device according to the first embodiment of the present invention, and FIG. 1B is a cross-sectional view taken along the line BB ′ of FIG. This heat exchange device is, for example, in the form of a sheet and includes a heat dissipation layer 10 and a bonding layer 20. The bonding layer 20 is provided on the lower surface of the heat dissipation layer 10.

  The heat dissipation layer 10 is formed of, for example, a shape memory alloy or a bimetal in which two metal layers having different coefficients of thermal expansion are stacked. The heat dissipation layer 10 is bent to the upper surface side when the temperature rises, and the shape is restored when the temperature is lowered. Return to.

  The bonding layer 20 is a layer for bonding (for example, adhering) the heat dissipation layer 10 to the surface of the object to be cooled or heated, and the lower surface of the heat dissipation layer 10 excluding the plurality of non-bonded regions 22. Is provided. In the present embodiment, the non-joining regions 22 form a plurality of rows and are arranged to be staggered between adjacent rows. The bonding layer 20 is preferably formed of a heat conductive adhesive having a high thermal conductivity (for example, an adhesive mixed with a filler having a higher thermal conductivity than the adhesive).

  The heat dissipation layer 10 is provided with a plurality of thermal deformation portions 12. The thermal deformation portion 12 is formed by separating the peripheral portion of the heat dissipation layer 10 located in the non-bonding region 22 from the main body of the heat dissipation layer 10 except for a part thereof. In the present embodiment, the thermal deformation portion 12 is formed by cutting the peripheral portion of the non-bonded region 22 from the main body of the heat dissipation layer 10 into a substantially U shape, but along three sides of four sides constituting the rectangle. It may be formed by separating from the main body of the heat dissipation layer 10, or may be formed by separating from the main body of the heat dissipation layer 10 along two sides of the three sides constituting the triangle. In the present embodiment, the thermal deformation section 12 forms a plurality of rows and is arranged so as to be staggered between adjacent rows. Moreover, the part connected to the main body of the heat radiating layer 10 in the heat-deformed portion 12 faces the same direction, and is aligned at substantially the same position (left end in the figure) in the non-bonding region 22.

  FIG. 2 is a cross-sectional view for explaining the operation of the heat exchange apparatus shown in FIG. In this figure, the heat exchanging device is cut into an appropriate shape and then attached to the heat sink 50 of the electronic component. When heat is transmitted from the heat sink 50, the heat is radiated from the surface of the heat dissipation layer 10 to the air.

  The heat deformable portion 12 conducts heat from a portion of the heat dissipation layer 10 located around the heat deformable portion 12. As described above, the bonding layer 20 is not provided on the lower surface of the thermally deformable portion 12, and thus the thermally deformable portion 12 is not fixed to the heat sink 50. Therefore, the heat dissipation layer 10 is substantially flush with the main body of the heat dissipation layer 10 when the temperature is lower than a certain value, but when the temperature becomes a certain value or more, it warps upward as indicated by an arrow A. . In a state along the top, heat is radiated to the air from both the front surface and the back surface of the heat-deformed portion 12, so that the heat radiation area of the heat radiation layer 10 is increased.

  Therefore, when an abnormal load is applied to the electronic device and the temperature of the heat sink 50 exceeds a certain value, the heat dissipation area of the heat dissipation layer 10 increases and the temperature of the heat sink 50 decreases. On the other hand, when the electronic device is in a steady state, the temperature of the heat sink 50 is less than a certain value, and the thermal deformation portion 12 does not warp upward. For this reason, the heat dissipation area of the heat dissipation layer 10 does not increase, and the temperature of the heat sink 50 does not decrease more than necessary.

  Note that the heat exchange device according to the present embodiment may be affixed to a device other than the heat sink 50, for example, an inner surface of a casing of an electronic device or a semiconductor device after being packaged with a resin.

  As described above, according to the first embodiment, when an abnormal load is applied to the electronic device and the temperature of the heat sink 50 becomes equal to or higher than a certain value, the heat dissipation area of the heat dissipation layer 10 increases and the temperature of the heat sink 50 decreases. On the other hand, when the electronic device is in a steady state, the temperature of the heat sink 50 is less than a certain value, and the heat dissipation area of the heat dissipation layer 10 does not increase, so the temperature of the heat sink 50 does not decrease more than necessary. For this reason, for example, even in a cold region, there is a high probability that the temperature of the electronic component falls within the range where the designed performance can be achieved.

  Moreover, since the heat-deformation part 12 warps by heat, electric power is not required and durability is high. Moreover, since it is a sheet | seat shape, a large space is not required for installation and it can affix directly on arbitrary places, such as the heat sink 50. FIG.

  The heat exchange device may be attached to the inner surface of the water pipe in the boiler. In this case, the thermal efficiency of the boiler is improved.

  FIG. 3A is a plan view of a heat exchange device according to the second embodiment of the present invention, and FIG. 3B is a cross-sectional view taken along the line BB ′ of FIG. The heat exchange device shown in this figure has the same configuration as that of the heat exchange device according to the first embodiment, except that the ventilation path 24 is provided in the bonding layer 20. Moreover, the usage method of a heat exchange apparatus is the same as that of 1st Embodiment. The air passage 24 is formed by providing a groove in the bonding layer 20 or by not providing the bonding layer 20 partially.

  In the present embodiment, the air passage 24 connects the spaces below the heat-deformed portions 12 belonging to the same row to each other, and connects the space below the heat-deformed portions 12 located on the outermost side to the outside of the heat exchange device. It is out. In addition, the ventilation path extended in the horizontal direction in the figure may be further formed, and the space below the thermally deformable portions 12 belonging to different rows may be connected to each other by this ventilation path.

  Also in this embodiment, the same operations and effects as those in the first embodiment can be obtained. Further, since the air flows in the air passage 24 when the heat deforming portion 12 moves, the cooling efficiency of the heat sink and the like is further improved.

  FIG. 4A is a plan view of a heat exchange device according to the third embodiment of the present invention, and FIG. 4B is a cross-sectional view taken along the line BB ′ of FIG. The heat exchange apparatus shown in the figure has the same configuration as the heat exchange apparatus according to the first embodiment except that a through hole 12a is provided at the approximate center of the heat deforming portion 12. Moreover, the usage method of a heat exchange apparatus is the same as that of 1st Embodiment.

  Also in this embodiment, the same operations and effects as those in the first embodiment can be obtained. In addition, in a state where the thermal deformation portion 12 is substantially flush with the main body of the heat dissipation layer 10, the air located in the space below the thermal deformation portion 12 is warmed by a heat sink or the like and then upward through the through hole 12 a. Flows out. For this reason, the cooling efficiency of a heat sink etc. improves further.

  In this embodiment, the air passage 24 shown in the second embodiment may be provided. In this case, air flows into the space below the thermally deformable portion 12 through the air passage 24 and then flows upward through the through hole 12a. For this reason, the air flow in the space below the thermal deformation portion 12 is improved, and the cooling efficiency of the heat sink and the like is further improved.

  FIG. 5A is a plan view of a heat exchange device according to the fourth embodiment, and FIG. 5B is a cross-sectional view taken along the line BB ′ of FIG. In the heat exchange device according to the present embodiment, the heat dissipation layer 10 is formed of a normal metal instead of a shape memory alloy or a bimetal, the heat deformation portion is not formed in the heat dissipation layer 10, and the lower surface of the heat dissipation layer 10 A plurality of thermal deformation portions 32 are attached to the surface where the bonding layer 20 is provided on the entire surface and the upper surface of the heat dissipation layer 10. Hereinafter, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  The heat-deformed portion 32 is formed of a shape memory alloy or bimetal, and bends upward as the temperature rises and returns to its original shape as the temperature falls. One end portion 32 a of the thermally deformable portion 32 is connected to the surface of the heat dissipation layer 10 via the heat conductive adhesive 30. As for the some thermal deformation part 32, the one end part 32a has faced the mutually same direction. In addition, the planar shape and arrangement | positioning of the heat deformation part 32 are the same as that of the heat deformation part 12 in 1st Embodiment.

The thermal deformation portion 32 is in contact with the surface of the heat dissipation layer 10 except for the one end portion 32a and the vicinity thereof in a state where the temperature is less than a certain value. The thermal deformation portion 32 warps upward when the temperature becomes a certain value or more due to heat conduction from the heat radiation layer 10.
Therefore, also in this embodiment, the same operation and effect as the first embodiment can be obtained.

  Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, in the first to fourth embodiments, the thermal deformation units 12 and 32 are arranged so as to be staggered between adjacent columns, but may be arranged so as to overlap each other between adjacent columns. .

  Further, the heat dissipation layer 10 in the first to third embodiments and the thermal deformation portion 32 in the fourth embodiment are formed of a material that bends upward as the temperature decreases and returns to its original state as the temperature increases. May be. If it does in this way, a heat exchanging device can be used as a heating sheet which absorbs heat from the outside. In this case, the heat exchange device is attached to, for example, the outer wall of the water pipe in the boiler, and is used to increase the heating efficiency of the outer wall.

  In the first to fourth embodiments, the thicknesses of the heat dissipation layer 10 and the heat deformable portion 32 are not particularly limited, and the heat dissipation layer 10 may be thickened to have a rod shape.

  The present invention can be used by being joined to a portion requiring heat exchange.

(A) is a top view of the heat exchange apparatus which concerns on 1st Embodiment, (B) is BB 'sectional drawing of (A). Sectional drawing for demonstrating the usage method of a heat exchange apparatus. (A) is a top view of the heat exchange apparatus which concerns on 2nd Embodiment, (B) is BB 'sectional drawing of (A). (A) is a top view of the heat exchange apparatus which concerns on 3rd Embodiment, (B) is BB 'sectional drawing of (A). (A) is a top view of the heat exchange apparatus which concerns on 4th Embodiment, (B) is BB 'sectional drawing of (A).

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Heat transfer layer, 12, 32 ... Deformation part, 12a ... Through-hole, 20 ... Adhesive layer, 22 ... Non-joining area | region, 24 ... Air passage, 30 ... Thermally conductive adhesive, 50 ... Heat sink

Claims (7)

A heat dissipation layer formed of a material that bends in the first surface direction when the temperature changes and returns to its original shape when the temperature returns;
A bonding layer provided on the second surface of the heat dissipation layer and fixing the heat dissipation layer to another object;
A non-joint region which is a part of the heat dissipation layer and is not provided with the joining layer on the second surface;
A thermal deformation part formed by separating the peripheral edge part of the non-joining region from the main body of the heat dissipation layer except for a part thereof;
A heat exchange device comprising:   2. The heat exchange device according to claim 1, wherein the heat dissipation layer is formed of a shape memory alloy or a bimetal obtained by superimposing two metal layers having different thermal expansion coefficients. Comprising a plurality of the non-bonded region and the deformed portion;
2. The heat exchange device according to claim 1, wherein portions of the plurality of deformable portions connected to a main body of the heat radiation layer face substantially the same direction. Comprising a plurality of the non-bonded region and the deformed portion;
Provided in the bonding layer, comprising a ventilation path that interconnects the spaces located below the plurality of non-bonding regions and connects the space located below any of the non-bonding regions to the atmosphere, The heat exchange device according to claim 1.   The heat exchange device according to claim 1, further comprising a through hole provided in the deformable portion. A heat dissipation layer;
It is formed of a material that bends in the direction of the first surface when the temperature changes and returns to its original shape when the temperature returns, and a part of the second surface can conduct heat to the heat dissipation layer. A heat-deformed portion fixed in a state;
A heat exchange device comprising:   The heat exchange device according to claim 6, wherein the thermal deformation portion is formed of a shape memory alloy or a bimetal in which two metal layers having different thermal expansion coefficients are stacked.

Images