JP5089538B2 - Heat sink with piezoelectric fan - Google Patents

Description

  The present invention relates to a heat sink, and more particularly, to a heat sink with a piezoelectric fan that forcibly air-cools heat radiating fins of the heat sink by a piezoelectric fan.

  In recent years, heat generation from electronic components has been further increased due to high speed, high functionality, miniaturization, and the like of electronic components typified by a CPU. Conventionally, a heat sink is used to cool an electronic component that generates heat (hereinafter referred to as a heat generating component). The heat sink generally includes a base plate that is thermally connected to the heat generating component, and a plurality of radiating fins that stand on the base plate and radiate heat from the heat generating component that is conducted to the base plate. And in order to increase the heat radiation amount from a radiation fin rather than by natural convection, installing the fan which ventilates cooling air to a radiation fin with a heat sink is performed.

  As a heat sink with a fan, a heat sink having a fan having rotating blades that are rotated by a motor is generally known as disclosed in Japanese Patent Application Laid-Open No. 2001-053201. However, this rotary fan requires a large amount of power to generate cooling air, and thus has a problem that power consumption increases and a wind noise from the rotating blades causes noise.

  In order to solve these problems, a heat sink with a piezoelectric fan is known as a heat sink including a fan that does not use rotating blades (see Patent Document 1). In a piezoelectric fan, a fan blade made of a thin metal plate is attached between two plate-like piezoelectric elements, and when an AC voltage is applied to the piezoelectric element, one piezoelectric element contracts and the other piezoelectric element expands. As a result, the fan blades vibrate and cooling air is generated. A heat sink with a piezoelectric fan is formed by attaching such a piezoelectric fan to a base plate or the like via an attaching means. The heat sink with a piezoelectric fan described in Patent Document 1 has a fixed frame, a support beam, and a support as mounting means, and a plurality of support beams supporting a plurality of fan blades are arranged on the fixed frame, and the fixing is performed. The frame is fixed to the heat sink using a column.

JP-A-8-330488

  However, in the heat sink with a piezoelectric fan described in Patent Document 1, the vibration of the fan blade is transmitted to the heat sink through the mounting means, and further, the heat generating component and the mounting board on which the heat generating component is mounted are vibrated, In addition, there is a risk that the reliability of an electronic device on which the heat generating component and the mounting board are mounted may be reduced due to cracks in the solder provided for wiring on the mounting board.

  Accordingly, the present invention provides a heat sink with a piezoelectric fan in which the vibration of a fan blade is not transmitted to a heat generating component or a mounting board, and the reliability of an electronic device mounted with the heat generating component or the mounting board is not lowered. With the goal.

In order to achieve the above object, a heat sink with a piezoelectric fan according to the present invention includes a base plate that is thermally connected to a heat generating component, and heat from the heat generating component that is erected on the base plate and conducted to the base plate. It has a heat sink and a plurality of radiating fins for radiating a plurality of piezoelectric fan for blowing cooling air to the heat sink, and a mounting means for mounting said plurality of piezoelectric fan to the heat sink, the plurality of piezoelectric fan The surface where the cooling air of each piezoelectric fan is generated is substantially in the same range as the standing range of the plurality of heat radiation fins, and is substantially parallel to the surface of the base plate where the plurality of heat radiation fins are erected, and , together with the provided so as to align in the same plane, as the go tip is formed to narrow width, said plurality of piezoelectric fan Between the serial attachment means or / and, between the member and the member constituting the mounting means and / or, between the heat sink and the mounting means, to absorb the vibrations of the plurality of piezoelectric fan vibration An absorbent member is provided.

  In the heat sink with the piezoelectric fan described above, the vibration absorbing member may be made of an elastomer.

  In the heat sink with a piezoelectric fan described above, the vibration absorbing member may be formed of a piezoelectric element, and the piezoelectric element may operate in a phase opposite to that of the vibration of the piezoelectric fan.

Further, in the heat sink with a piezoelectric fan described above, prior Symbol fan blades, a vicinity of the distal end of the plurality of heat dissipating fins, the may be disposed between the heat radiation fins. At this time, the mounting means includes a support member for supporting collectively the ends of the plurality of piezoelectric fans, the support member provided at the tip end portion of the heat radiating fins located on both sides of the plurality of heat dissipating fins It is good to have a fixing | fixed part to which this is fixed, and the coupling means for couple | bonding the said supporting member and the said fixing | fixed part. At this time, the vibration absorbing member may be provided between the support member and the fixed portion. The fixing portion may be integrally formed with the heat radiating fin.

  According to the present invention, it is possible to prevent the vibration of the fan blade from being transmitted to the heat generating component or the mounting board, and cracks are made in the solder applied for wiring in the heat generating component or on the mounting board. The reliability of an electronic device equipped with a heat generating component or a mounting board is not lowered.

  Hereinafter, a heat sink 1 with a piezoelectric fan according to an embodiment of the present invention will be described with reference to FIGS. 1 to 4.

  As shown in FIG. 1, the heat sink 1 with a piezoelectric fan according to the present embodiment has a base plate 2 that is thermally connected to a heat-generating component (not shown), and the base plate 2 is conducted to the base plate 2. A plurality of plate-like radiation fins 3 for radiating heat from the heat-generating component are provided upright. Base plate 2 and heat radiating fin 3 are made of a metal having excellent thermal conductivity, such as copper or aluminum. The base plate 2 and the heat radiating fins 3 constitute a heat sink 4.

  Among the plurality of heat radiating fins 3, the heat radiating fins 3 positioned at both ends are formed taller than the other heat radiating fins 3, and the piezoelectric fan 6 is fixed to the tip end portion inward. A fixing part 5 is provided.

  The base plate 2, the heat radiating fins 3, and the fixing portions 5 are integrally formed by extrusion processing. Accordingly, it is not necessary to separately prepare an attachment structure member such as a retention, and the heat sink 1 with a piezoelectric fan can be manufactured easily and at low cost. In addition, only the radiation fin 3 and the fixing | fixed part 5 may be integrally formed by an extrusion process or a drawing process, and the radiation fin 3 and the base plate 2 may be comprised separately. In this case, for example, the base plate 2 is provided with a groove into which an end portion of the heat radiating fin 3 fixed to the base plate 2 can be inserted, and the heat radiating fin 3 is inserted into the groove to caulk the groove so that the heat radiating fin is attached to the base plate 2. 3 should be fixed.

  Further, the heat sink 4 is made of the material, density, and size of the base plate 2 and the heat radiating fin 3 so that the entire heat sink 4 does not resonate with the nth-order (n = 1, 2, 3,...) Overtone component of the operating frequency of the piezoelectric fan 6. It is advisable to set the appropriateness. Thereby, it is possible to prevent the heat sink 4 from resonating with the piezoelectric fan 6 and generating noise.

  A plurality of piezoelectric fans 6 for blowing cooling air to the heat radiating fins 3 are provided near the tips of the heat radiating fins 3. As shown in FIGS. 1 and 2, each piezoelectric fan 6 has two plate-like piezoelectric elements 7 made of, for example, a piezoelectric ceramic material. Between the two piezoelectric elements 7, for example, A thin plate-like fan blade 8 made of a metal such as phosphor bronze or a plastic is provided so that one end thereof extends from both ends of the piezoelectric element 7 long. Each piezoelectric fan 6 has a length and a width that can be accommodated between the heat radiating fins 3 and the heat radiating fins 3, and the fan blades 8 extend from the piezoelectric elements 7 as shown in FIG. 4. It is formed so that the width becomes narrower as the end portion of the is closer to the tip end.

  The piezoelectric fan 6 is connected to a power supply circuit (not shown). When an AC voltage is applied from the power supply circuit, when one piezoelectric element 7 contracts, the other piezoelectric element 7 expands. Such expansion / contraction strain causes bending strain in the fan blade 8 so that the fan blade 8 vibrates.

  In this embodiment, the fan blade 8 is sandwiched between the two piezoelectric elements 7 and attached to the piezoelectric element 7. However, only one of the piezoelectric elements may be used.

  The end of the fan blade 8 on the side that extends short from the piezoelectric element 7 is made of metal, plastic, or the like, and the surface of the fan blade 8 that causes wind by the support member 9 that supports the fan blade 8 collectively. The heat dissipating fins 3 are supported so as to be arranged so as to be arranged in the same plane.

  The fixing portion 5 and the support member 9 are each provided with a screw groove (not shown), and the screw 10 is screwed into both screw grooves, so that the support member 9 is fixed to the fixing portion 5 and the fan blade. 8, the surface of the fan blade 8 that causes wind and the surface of the base plate 2 on which the radiating fins 3 are erected are parallel, and between the radiating fins 3 and the radiating fins 3, the tips of the radiating fins 3. It is fixed so that it is located in the vicinity.

  As described above, since the piezoelectric fan 6 is provided so as to be positioned between the heat radiating fins 3 and the heat radiating fins 3, the piezoelectric fan 6 fits in the substantially same range as the radiating fins 3 of the base plate 2. Space saving in a direction parallel to the standing surface of the radiation fin 3 can be achieved. In addition, since the piezoelectric fan 6 is provided in the vicinity of the tips of the heat radiating fins 3 so that the surface of the fan blade 8 that causes wind is parallel to the surface on which the heat radiating fins 3 of the base plate 2 are erected. Space saving in the direction perpendicular to the surface on which 3 is erected can be achieved.

  The piezoelectric fan 6 is provided between the radiating fins 3 and the radiating fins 3 and in the vicinity of the tip of the radiating fin 3, but the width of the fan blade 8 becomes narrower toward the tip. Therefore, the longitudinal center line of the fan blade 8 and the longitudinal center of the radiating fin 3 are caused by the dimensional tolerance of the piezoelectric fan 6 and the supporting member 9 and the variation in the mounting position of the piezoelectric fan 6 on the supporting member 9. Even when the fan blades 8 are not mounted so as to be parallel to the wire, the tips of the fan blades 8 do not interfere with the radiating fins 3, and noise and breakage due to vibrations of the fan blades 8 are prevented. Can do.

Between the fixed part 5 and the support member 9, a vibration absorbing member is made of an elastomer such as rubber and has a hole (not shown) through which the screw 10 can pass and has substantially the same size as the fixed part 5. A member 11 is interposed. The screw groove and the screw 10 provided in the fixing portion 5 and the support member 9 constitute a coupling means described in the claims, and the fixing portion 5, the support member 9, the screw groove, and the screw 10 are The attachment means described in the claims is configured.

  Since the heat sink 1 with a piezoelectric fan is configured as described above, when an AC voltage is applied to the piezoelectric fan 6, the fan blade 8 vibrates to generate wind, which is blown between the heat radiating fins 3 to dissipate heat. The heat from the heat generating component conducted to the fin 3 is forcibly radiated. In particular, since the fan blades 8 are provided between the heat radiating fins 3, the wind passes between the heat radiating fins 3, and heat is radiated efficiently. At this time, since the vibration of the fan blade 8 is absorbed by the vibration absorbing member 11, transmission to the heat sink 4 through the fixing portion 5 is reduced.

  As described above, according to the heat sink 1 with a piezoelectric fan according to the present embodiment, the vibration of the fan blade 8 can be prevented from being transmitted to the heat generating component or the mounting board on which the heat generating component is mounted. It can be suppressed that the reliability of the electronic device on which these heat generating components and the mounting board are mounted, for example, by cracking the solder applied for wiring on the board.

  In the present embodiment, the piezoelectric fan 6 is provided so as to be positioned between the radiating fins 3. However, as shown in FIG. 5, the interval between the radiating fins 3 is narrower than the width of the piezoelectric fan 6. The radiating fins 3 may be erected on the base plate 2, and the piezoelectric fan 6 may be provided above the tips of the radiating fins 3 so as not to interfere with the tips of the radiating fins 3 even when the fan blade 8 vibrates.

  Further, as shown in FIG. 6, the piezoelectric fan 6 may be provided between the radiation fin 3 and the radiation fin 3 and between the tip of the radiation fin 3 and the base plate 2. In this case, it is preferable to provide the fixing portion 5 between the tips of the radiation fins 3 of the radiation fins 3 and the base plate 2.

  Even in these cases, by providing the vibration absorbing member 11 between the fixed portion 5 and the support member 9, the vibration of the fan blade 8 is absorbed by the vibration absorbing member 11, and the transmission to the heat sink 4 is reduced. Yes.

  Moreover, in this Embodiment, although the vibration-absorbing member 11 was comprised with the elastomer, you may make it comprise not only this but the felt which consists of an aggregate | assembly of a fiber, for example. Further, the vibration of the fan blade 8 may be canceled by applying an AC voltage having a phase opposite to that of the piezoelectric element 7 that is constituted by a piezoelectric element and constituting the piezoelectric fan 6.

  In the present embodiment, the vibration absorbing member 11 is provided between the fixed portion 5 and the support member 9, but may be provided between the fan blade 8 and the support member 9. Further, the end portion of the fan blade 8 may be supported by a vibration absorbing member 11 formed in the same shape as the support member 9 by using an elastomer or the like instead of the support member 9. In this case, the fixing portion 5 and the coupling means constitute the attachment means described in the claims. Further, the support member 9 that supports the fan blade 8 may be fixed to a vibration absorbing member 11 formed in the same shape as the fixed portion 5 instead of the fixed portion 5. In this case, the support member 9 and the coupling means constitute the attachment means described in the claims. Furthermore, you may make it provide the vibration absorption member 11 in multiple places combining the said aspect.

  Next, another embodiment of the present invention will be described with reference to FIG. As shown in FIG. 7, the heat sink 20 with the piezoelectric fan according to the present embodiment includes a base plate 21 and a plurality of heat radiation fins 22 erected on the base plate 21. A heat sink 23 is configured.

  Fixing members 25 for fixing the piezoelectric fan 24 are provided on both side surfaces of the base plate 21 and extend in the standing direction of the heat radiation fins 22.

  In addition, the heat sink 23 is configured in the same manner as the heat sink 4 in the first embodiment.

  A plurality of piezoelectric fans 24 are provided above the radiation fins 22. Each piezoelectric fan 24 has two plate-like piezoelectric elements 26, and a thin plate-like fan blade 27 is interposed between the two piezoelectric elements 26, and both end portions thereof are both ends of the piezoelectric element 26. One side is provided so as to extend long.

  When an AC voltage is applied to the piezoelectric fan 24, when the one piezoelectric element 26 contracts, the other piezoelectric element 26 expands. As a result, the fan blade 27 vibrates. Yes.

  The ends of the fan blades 27 that extend short from the piezoelectric elements 26 are made of metal, plastic, or the like, and the surface of the fan blades 27 that causes wind is supported by the support members 28 that collectively support the fan blades 27. It is supported so as to be aligned in the same plane.

  The fixing member 25 and the supporting member 28 are each provided with a thread groove (not shown), and the screw 29 is screwed into both the thread grooves, so that the supporting member 28 is fixed to the fixing member 25 and the fan blade. 27 is fixed so that the wind is sent toward the base plate 21.

Between the fixing member 25 and the support member 28, it is made of an elastomer such as rubber, has a size substantially the same as the surface on which the support member 28 is fixed to the fixing member 25, and a hole through which the screw 29 can pass ( A vibration absorbing member 30 provided (not shown) is interposed. The fixing member 25, the support member 28, the thread groove, and the screw 29 constitute attachment means described in the claims.

Since the heat sink 20 with a piezoelectric fan is configured as described above, when an AC voltage is applied to the piezoelectric fan 24, the fan blades 27 vibrate to generate wind, which is blown between the radiation fins 22 to dissipate heat. The heat from the heat generating component conducted to the fin 22 is forcibly radiated. At this time, since the vibration of the fan blade 27 is absorbed by the vibration absorbing member 30, transmission to the heat sink 23 through the fixing portion 5 is reduced.

  As described above, according to the heat sink 20 with a piezoelectric fan according to the present embodiment, the vibration of the fan blade 27 can be prevented from being transmitted to the heat generating component or the mounting board on which the heat generating component is mounted. It can be suppressed that the reliability of the electronic device on which these heat generating components and the mounting board are mounted, for example, by cracking the solder applied for wiring on the board.

  In the present embodiment, the vibration absorbing member 30 is provided between the fixing member 25 and the support member 28. However, the vibration absorbing member 30 may be provided between the base plate 21 and the fixing member 25, or both. You may make it provide in.

It is a perspective view showing typically composition of one embodiment of a heat sink with a piezoelectric fan concerning the present invention. It is sectional drawing which shows typically the structure of the piezoelectric fan with which the heat sink with a piezoelectric fan of FIG. 1 was equipped. It is sectional drawing which shows typically the structure of the heat sink with a piezoelectric fan of FIG. It is a top view which shows typically the structure of the heat sink with a piezoelectric fan of FIG. It is a perspective view which shows typically the structure of the modification of 1st embodiment. It is a perspective view which shows typically the structure of the other modification of 1st embodiment. It is a perspective view which shows typically the structure of other embodiment of the heat sink with a piezoelectric fan which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,20 Heat sink with piezoelectric fan 2,21 Base plate 3,22 Radiation fin 4,23 Heat sink 5 Fixed part 6,24 Piezoelectric fan 7,26 Piezoelectric element 8,27 Fan blade 9,28 Support member 11,30 Vibration absorbing member

Claims (8)

A heat sink comprising: a base plate that is thermally connected to the heat-generating component; and a plurality of heat-dissipating fins that radiate heat from the heat-generating component that is erected on the base plate and conducted to the base plate;
A plurality of piezoelectric fans for blowing cooling air to the heat sink;
An attachment means for attaching the plurality of piezoelectric fans to the heat sink;
In the plurality of piezoelectric fans, a surface that generates cooling air of each of the piezoelectric fans is substantially the same range as a standing range of the plurality of radiating fins, and is substantially the same as a surface of the base plate on which the plurality of radiating fins are erected. It is provided to be parallel and arranged in the same plane, and the width is narrowed toward the tip.
Between said plurality of piezoelectric fan and the mounting means and / or, between the member and the member constituting the mounting means and / or, between the heat sink and the mounting means, said plurality of piezoelectric fans, A heat sink with a piezoelectric fan, characterized in that a vibration absorbing member for absorbing the vibration of the piezoelectric fan is provided.   The heat sink with a piezoelectric fan according to claim 1, wherein the vibration absorbing member is made of an elastomer. The vibration absorbing member is composed of a piezoelectric element,
2. The heat sink with a piezoelectric fan according to claim 1, wherein the piezoelectric element operates in a phase opposite to a vibration of each of the piezoelectric fans. 4. The device according to claim 1, wherein the plurality of piezoelectric fans are disposed between tips of the plurality of heat radiation fins and between the heat radiation fins. 5. Heat sink with piezoelectric fan as described. The heat sink with a piezoelectric fan according to any one of claims 1 to 4, wherein the attachment means includes a support member that collectively supports end portions of the plurality of piezoelectric fans . It said mounting means includes a fixed portion to which the supporting member provided at the tip end portion of the heat radiating fins located at both ends of the plurality of heat dissipating fins are fixed, for coupling the support member and the fixing portion 6. A heat sink with a piezoelectric fan according to claim 5, further comprising coupling means.   The heat sink with a piezoelectric fan according to claim 6, wherein the vibration absorbing member is provided between the support member and the fixing portion.   The heat sink with a piezoelectric fan according to claim 6 or 7, wherein the fixing portion is formed integrally with the heat dissipating fins.

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