JP2006216806A - Heat transfer unit using thermoelectroc element and heat transfer device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat transfer unit for highly efficiently radiating the heat generated in an electronic equipment and transferred to the heat radiating part. <P>SOLUTION: The heat transfer unit comprises: a thermoelectric element 3; a heat transfer substrate 5 for cooling fixed to the surface 3a for absorbing and transferring heat of the element 3; and a heat transfer substrate 7 for radiating heat fixed to the surface 3b for radiating and transferring heat of the element 3. A transducer 20 is provided at least either of the substrate 5 or the substrate 7. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a heat transfer unit using a thermoelectric element having a Peltier effect, and a heat transfer device in which the unit is attached to a predetermined support base, and particularly generated inside an electronic device and transported to a heat dissipation part. The present invention relates to a heat transfer unit and a device for efficiently radiating heat.

  A portable electronic device such as a portable computer is equipped with an MPU (Micro Processing Unit) for processing a variety of multimedia information such as characters, sounds and images. With this type of MPU, the power consumption continues to increase as the information processing speed increases and the number of functions increases, and the amount of heat generated during operation tends to increase in proportion to this. Further, desktop computers having display devices are required to be smaller and thinner in addition to higher functionality, and the heat generation density of electronic devices is steadily increasing.

  Therefore, in order to guarantee stable operation of the MPU, it is necessary to improve the heat dissipation of the MPU, and therefore various heat dissipation / cooling means such as a heat sink and a heat pipe are indispensable.

  In order to cope with these problems, in recent years, there is a so-called liquid cooling cooling method that uses a liquid having a specific heat much higher than that of air as a heat transport fluid (cooling liquid) to improve the cooling efficiency of the MPU. Has been tried.

  For example, in Patent Document 1, as a means for cooling an MPU of a display-integrated computer, a heat receiving portion is fixed to a heat generating portion such as a mother board, a cooling tube through which a coolant is circulated is connected to the heat receiving portion, and this cooling is performed. A liquid cooling cooling method has been proposed in which the tube is fixed to the surface of the chassis that is placed behind the liquid crystal display with a gap so that the heat generated in the heat generating part is dissipated through the tube and the chassis fixed to the chassis surface. Yes.

Further, Patent Document 2 includes a heat receiving part thermally connected to the MPU and a heat radiating part thermally connected to the display unit. Liquid cooling is provided inside the heat receiving part and inside the heat radiating part. There has been proposed an electronic device in which a flow path through which a liquid flows is formed. In such a liquid cooling system for electronic devices, the coolant flow path of the heat receiving part and the coolant flow path of the heat radiating part are connected to each other via a circulation path for circulating the coolant, and the heat of the MPU is received by the heat receiving part. After being transferred to the coolant, it is multiplied by the flow of the coolant and transferred to the heat radiating section, and the heat transferred to the heat radiating section is diffused by heat conduction while the coolant flows through the flow path. Is released into the atmosphere through the display unit.
JP 2002-182796 A JP 2002-374084 A

  However, in the conventional liquid cooling cooling method, in order to efficiently release the heat stored in the cooling liquid, which is a heat transport fluid, to the atmosphere at the heat radiating part, a thin tube-like flow path is used to secure the heat transfer area. Used. For this reason, due to the pressure loss in the flow path, a load is applied to the cooling liquid circulation device, and the flow rate of the circulating cooling liquid is limited. It is possible to increase the coolant circulation system and increase the coolant flow rate to ensure the required flow rate, but this increases the size of the electronic equipment itself and increases the power consumption. is there.

  Furthermore, in the conventional method, the heat radiating part dissipates heat by natural convection of the atmosphere (air) or forced convection with a blower added, so the MPU is forcibly cooled by lowering the coolant temperature below the ambient temperature, In principle, it was impossible to suppress the temperature rise of electronic devices.

  Accordingly, an object of the present invention is to provide a heat transfer unit and a heat transfer device that can efficiently dissipate heat generated inside an electronic device and transported to a heat radiating portion.

  In order to solve the above-mentioned problems, the present inventors have made various studies on the heat transfer method between the heat transport fluid and the atmosphere in the heat dissipating part. The surface of the heat dissipating part is vibrated by vibrating the heat transfer surface. It is found that the temperature boundary layer of the heat transport fluid generated in the heat transfer fluid can be effectively removed and the heat transfer efficiency can be improved, and further that the heat transfer efficiency can be further improved by using the heat transfer element, and the present invention. Reached.

  According to the present invention, it comprises a thermoelectric element, a cooling heat transfer substrate attached to the heat absorption heat transfer surface of the thermoelectric element, and a heat dissipation heat transfer substrate attached to the heat dissipation heat transfer surface of the thermoelectric element, A vibrator is provided on at least one of the cooling heat transfer substrate and the heat dissipation heat transfer substrate.

In the present invention,
(1) the vibrator is a piezoelectric element;
(2) The cooling heat transfer substrate and the heat dissipation heat transfer substrate are ceramic substrates,
Preferably, in such a heat transfer unit, the first heat transport medium to be cooled is flowed on the surface of the cooling heat transfer substrate, and is radiated from the substrate on the surface of the heat dissipation heat transfer substrate. By flowing the second heat transport medium, heat is radiated from the first heat transport medium that is the cooling medium to the second heat transport medium (for example, air).

  According to the present invention, there is provided a support base, a first heat transfer unit disposed on one surface of the support base, and a second heat transfer unit disposed on the other surface of the support base. And the first heat transfer unit and the second heat transfer unit are the heat transfer units, and each of these heat transfer units has one surface of the support base or The vibration of the vibrator of the first heat transfer unit and the vibration of the vibrator of the second heat transfer unit are bonded to the other surface and have the same frequency and the phase of the vibration is set to the opposite phase. A heat transfer device is provided.

  In the heat transfer unit of the present invention, the cooling heat transfer substrate in contact with the first heat transport medium as the cooling medium or the heat dissipation heat transfer substrate in contact with the second heat transport medium as the heat dissipation medium is vibrated by the vibrator. Thereby, the temperature boundary layer of the heat transport medium formed on the surface of the heat transfer substrate can be effectively removed, and heat transfer from the first heat transport medium to the second heat transport medium can be promoted.

  As a result, sufficient heat dissipation can be achieved with a small heat radiating portion, and there is no need to use a thin tube-like channel for securing a heat transfer area.

  Furthermore, since heat transfer is performed using a heat transfer element, the first heat transport medium can be cooled below the average temperature of the second heat transport fluid, further improving the cooling performance of the heat generating portion. be able to.

  In particular, when a piezoelectric element is used as the vibrator, the responsiveness is good and the frequency, amplitude, and vibration phase can be easily adjusted, and a ceramic substrate is used as a heat transfer substrate for cooling or heat dissipation. In such a case, even a highly corrosive fluid can be stably used as a heat transport medium.

  Further, in the heat transfer device in which the heat transfer unit described above is provided on each of both surfaces of a predetermined support base, the vibrator provided on one surface and the vibrator provided on the other surface are Since the vibration frequency is set to be the same and opposite in phase, the reaction of the vibration generated in the support base can be canceled out, and the noise accompanying the vibration can be greatly reduced.

Hereinafter, the present invention will be described based on specific examples shown in the accompanying drawings.
FIG. 1 is a schematic sectional view showing the structure of the heat transfer unit of the present invention,
FIG. 2 is an enlarged view showing a thermoelectric element which is a main part of the electric heating unit of FIG.
FIG. 3 is a schematic cross-sectional view showing the structure of a heat transfer device that uses the heat transfer unit of FIG. 1 attached to a predetermined support base.

  Referring to FIG. 1, the heat transfer unit of the present invention indicated by 1 as a whole is provided with a thermoelectric element 3, and a heat absorbing heat transfer surface 3 a (which becomes a high temperature side heat transfer portion) of the thermoelectric element 3 is used for cooling. A heat transfer substrate 5 is provided, and a heat dissipation heat transfer substrate 7 is provided on the heat dissipation heat transfer surface 3 b of the thermoelectric element 3 (which becomes a low temperature side heat transfer portion).

  The thermoelectric element 3 is also called a Peltier element, and is a device that exhibits a cooling action (or heating action) by flowing a current through the thermoelectric element semiconductor / metal, and is known per se. That is, referring to FIG. 2 for explaining the structure of this thermoelectric element 3, this thermoelectric element 3 has a structure in which P-type semiconductor elements 10 and N-type semiconductor elements 11 are alternately connected in series by electrodes 13. As shown in FIG. 2, when a current is supplied using a power source 15, an endothermic reaction is generated at the lower joint portion to form an endothermic heat transfer surface 3a, and a cooling heat transfer substrate is formed in this portion. 5 is bonded, and an exothermic reaction is generated at the upper bonded portion to form the heat radiating heat transfer surface 3b, and the heat radiating heat transfer substrate 7 is bonded to this portion. In this case, assuming that the current flow is in the reverse direction, the heat absorption heat transfer surface 3a is formed at the upper joint, and therefore, the cooling heat transfer substrate 5 is bonded to the upper portion and the heat generation heat transfer surface 3b is bonded to the lower portion. The heat transfer substrate 7 for heat dissipation is joined to the lower portion.

  Accordingly, the first heat transport medium A that is a medium to be cooled is flowed so as to be in contact with the lower cooling heat transfer substrate 5 in FIG. 1, and the second heat transport medium B for heat dissipation is the upper part. It is made to flow in contact with the heat transfer substrate 7 for heat radiation. In this case, the first heat transport medium A and the second heat transport medium B are caused to flow so as not to contact each other. In FIG. 1, the electrode 13 and the power source 15 are omitted.

  In the heat transfer unit 1 of the present invention as described above, the P-type or N-type semiconductor forming the thermoelectric element 3 may be known per se, for example, a small amount of bismuth (Bi) -tellurium (Te). And antimony (Sb) and selenium (Se) added. Moreover, copper etc. are used as the electrode 13, and the heat-transfer board | substrate 5 for cooling and the heat-transfer board | substrate 7 for thermal radiation are joined by adhesive materials, such as solder.

Further, the cooling heat transfer substrate 5 and the heat dissipation heat transfer substrate 7 may be formed of a highly heat conductive material such as metal, but are generally formed of ceramics having high heat conductivity. In particular, AlN, Si ₃ N _{4 and the} like are preferably used. That is, since the heat transfer substrate 5 for cooling and the heat transfer substrate 7 for heat dissipation are in contact with the heat transport medium A or B, the types of the heat transport media A and B are limited when the metal one is used, and corrosion is caused. A highly compatible medium (such as water) cannot be used. However, when ceramic substrates are used as these substrates 5 and 7, since corrosion resistance is good, it becomes possible to use corrosive media as the heat transport media A and B. is there. In particular, the cooling heat transfer substrate 5 is most preferably a ceramic substrate.

  In the present invention, the first heat transport medium A is a medium cooled in the heat transfer unit 1, and a cooling medium used for cooling a heat generating portion of various electronic devices, for example, water, ethylene glycol or the like is used. Is done. The second heat transport medium B is a medium used for heat dissipation, and usually air (air) is used.

  In FIG. 1, the heat transfer substrate 5 for cooling and the heat transfer substrate 7 for heat dissipation are formed in a larger area than the thermoelectric element 3 in order to increase the heat transfer area. The space between 7 is usually filled with an electrically insulating material 17 such as rubber so that current leakage can be prevented. Moreover, as long as electrical insulation with the thermoelectric element 3 is ensured, it may be filled with a highly thermally conductive material such as metal.

  In such a heat transfer unit 1 of the present invention, as shown in FIG. 1, the vibrator 20 is attached to the cooling heat transfer board 5 with an adhesive such as solder. It is an important feature that it is bonded and fixed to a predetermined support base 21. That is, when cooling and heat dissipation are performed by the thermoelectric element 3 while applying vibration using such a vibrator 20, the temperature boundary layer of the first heat transport medium A formed on the surface of the cooling heat transfer substrate 5 is formed. Therefore, the heat transfer from the first heat transport medium A to the second heat transport medium B can be promoted.

  Various types of vibrators 20 can be used as the vibrator 20. For example, an electromagnetic motor may be used. However, in the present invention, since the response is high and the frequency and the phase of vibration can be easily controlled, the piezoelectric element Is preferably used as the vibrator 20. Such a piezoelectric element has a structure in which a plurality of piezoelectric layers and electrode layers made of, for example, perovskite-type piezoelectric ceramics are alternately stacked, and an upper electrode layer and a lower electrode layer of one piezoelectric layer. By applying potentials of different polarities to each other, vibration is applied in the thickness direction. In FIG. 1, a power source for driving the vibrator 20 is omitted. The electrical connection between the power source and the thermoelectric element is preferably performed using a flexible material such as a lead wire or a flexible substrate.

  The support base 21 to which the vibrator 20 is attached may be, for example, a housing or a motherboard of an electronic device, a housing wall of a heat radiating portion that serves as a heat transport fluid reservoir of the heat radiating portion, etc. Since the 1st heat transport medium A which is a cooling medium is poured by the side of this, it is suitable that it is a housing | casing wall of a motherboard or a thermal radiation part.

  In the present invention, the number of vibrators 20 is not particularly limited, and may be one, may be two as shown in FIG. 1, or may be more than that. Depending on the size and the like of the cooling heat transfer substrate 5 to be used, an appropriate number may be used so that the temperature boundary layer can be effectively removed. Further, the vibrator 20 can be provided on the heat transfer substrate 7 for heat radiation instead of being provided on the heat transfer substrate 5 for cooling. In this case, it is desirable that the support base 21 to which the vibrator 20 is bonded and fixed is a casing of the electronic device. Of course, the vibrator 20 may be provided on both the cooling heat transfer substrate 5 and the heat dissipation heat transfer substrate 7.

  It is particularly preferable that a plurality of the heat transfer units 1 of the present invention having the above-described structure are used as a heat transfer device by being attached inside various electronic devices. FIG. 3 shows a schematic structure of such a heat transfer device.

  In FIG. 3, in such a heat transfer device, for example, the heat transfer unit 1 having the above-described structure is provided on both surfaces of a support base 21 serving as a housing wall of a heat radiating portion in various electronic devices. That is, both surfaces of the support base 21 are structured such that the cooling heat transfer substrate 5 of the heat transfer unit 1 described above is bonded via the vibrator 20. A first heat transport medium A serving as a cooling medium is caused to flow between the heat substrate 5 and the second heat transport medium B serving as a heat dissipation medium on the surface of the heat transfer unit 1 on the heat dissipation heat transfer substrate 7 side. Will be washed away.

  In such a heat transfer device of the present invention, the vibrator 20a of the heat transfer unit 1 (first heat transfer unit) provided on one surface of the support base 21 and the other surface of the support base 21 are provided. The vibrator 20b of the heat transfer unit 1 (second heat transfer unit) is set so that the vibration frequency is the same and the phase is opposite (that is, the phase is shifted by 180 degrees). Is done. By controlling the vibration of the vibrator 20 in this way, the reaction of the vibration generated in the support base 21 is canceled out, and the noise accompanying the vibration can be greatly reduced.

  In addition, the support base 21 may be provided at a corresponding position so that the vibrator 20a provided on one surface of the support base 21 and the vibrator 20b provided on the other face face each other. It is most suitable for surely canceling the reaction of vibration.

  Further, in the heat transfer device of FIG. 3, the both surfaces of the support base 21 have a structure in which the cooling heat transfer substrate 5 is bonded via the vibrator 20. Depending on the position where the heat transport medium flows, it is possible to adopt a structure in which the heat-radiating electrothermal substrate 7 is bonded to both surfaces of the support base 21 via the vibrator 20.

  Furthermore, in the specific example of FIG.1 and FIG.3 mentioned above, although the support base 21 is shown on the flat plate, it does not need to be limited to such a shape.

  In the heat transfer unit or the heat transfer device of the present invention described above, since the thermoelectric element is used, the heat transfer area is large, the cooling and heat dissipation effect is extremely large, and the vibrator is used. The heat dissipation effect is further increased. In such a heat transfer unit or heat transfer device of the present invention, it is suitable for cooling the inside of an electronic device having a high heat generation MPU, for example, but cooling of another electronic device having a large heat generation density, such as a power amplifier, etc. It goes without saying that it may be applied to.

The schematic sectional drawing which shows the structure of the heat-transfer unit of this invention. The figure which expands and shows the thermoelectric element which is the principal part of the electric heating unit of FIG. The schematic sectional drawing which shows the structure of the heat-transfer apparatus which attaches and uses the heat-transfer unit of FIG. 1 to a predetermined | prescribed support base | substrate.

Explanation of symbols

1: Heat transfer unit 3: Thermoelectric element 3a: Endothermic heat transfer surface 3b: Heat dissipation heat transfer surface 5: Heat transfer substrate for cooling 7: Heat transfer substrate for heat dissipation 20: Vibrator 21: Support base A: First heat transport Medium B: Second heat transport medium

Claims (6)

  The cooling heat transfer board comprising: a thermoelectric element; a cooling heat transfer board attached to the heat absorption heat transfer surface of the thermoelectric element; and a heat dissipation heat transfer board attached to the heat dissipation heat transfer surface of the thermoelectric element. A vibrator is provided on at least one of the heat radiating heat transfer substrates.   The heat transfer unit according to claim 1, wherein the vibrator is a piezoelectric element.   The heat transfer unit according to claim 1 or 2, wherein the cooling heat transfer substrate and the heat dissipation heat transfer substrate are ceramic substrates.   A first heat transport medium to be cooled flows on the surface of the cooling heat transfer substrate, and a second heat transport medium radiated from the substrate flows on the surface of the heat dissipation heat transfer substrate. The heat transfer unit according to any one of claims 1 to 3.   A first heat transfer unit having a support base, a first heat transfer unit disposed on one surface of the support base, and a second heat transfer unit disposed on the other surface of the support base; The unit and the second heat transfer unit are the heat transfer units according to claim 1, and both of these heat transfer units are disposed on one surface or the other surface of the support base via the vibrator. The vibration of the vibrator of the first heat transfer unit and the vibration of the vibrator of the second heat transfer unit are joined, and the frequency is the same and the phase of the vibration is set to an opposite phase. Heat transfer device.   The heat transfer device according to claim 5, wherein each of the first heat transfer unit and the second heat transfer unit has a cooling heat transfer substrate joined to the support base via the vibrator.

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