JP2007035901A - Heat receiver and cooling device provided with the same - Google Patents

Abstract

A heat receiver for improving cooling performance by forming a micro fin on a contact surface with a liquid refrigerant flowing through a liquid flow path in a gap of a radiating fin and increasing the contact area where the liquid refrigerant contacts the radiating fin. An object of the present invention is to provide a cooling device provided.
A heat receiver 1 of the present invention is a heat receiver that connects a pair of liquid circulation paths and allows a liquid refrigerant to flow therein, and has a heat receiving surface 2b that is thermally connected to a heating element 13 on one surface. The other surface is combined with the heat receiving plate 2 having a plurality of heat radiating fins 3 and the heat receiving plate 2 so as to accommodate the heat radiating fins 3, and the space between the heat receiving plate 2 is a part of the flow path of the liquid refrigerant. And a plurality of micro fins 3 a are formed on the contact surface of the radiating fin 3 with the liquid refrigerant.
[Selection] Figure 2

Description

  The present invention uses a heat-generating electronic component such as a semiconductor element that generates heat such as a microprocessing unit (hereinafter referred to as MPU) used in a personal computer or the like, or an electronic component having other heat-generating parts, for cooling by circulation of a liquid refrigerant. The present invention relates to a heat receiver and a cooling device including the heat receiver.

  The speed of data processing in recent electronic devices such as computers is very rapid, and the clock frequency of heat-generating electronic components such as MPU has become much larger than before, so the amount of heat generated Has increased. For this reason, each heat generating electronic component exceeds the operating temperature range, and as a result, malfunctions and thermal destruction of the electronic components often occur.

  Therefore, keeping each heat generating electronic component mounted in the electronic device within the operating temperature range causes the heat generating electronic component to operate normally, and as a result, the electronic device can be stably operated. It has become an important issue to do so.

  As a conventional heat dissipation method for heat-generating electronic components, not only a heat sink composed of a plurality of heat-dissipating fins is brought into direct contact with the heat-generating electronic components for natural heat dissipation, but also a method in which the heat sink is blown and cooled by a fan device, heat receiving In the heat sink module that is thermally connected to the heat radiating part using a heat pipe, the heat radiating part is forcibly blown and cooled by fan blowing, or the liquid refrigerant is forced to circulate by a pump and the heat receiving part is transferred to the heat radiating part. Liquid cooling type cooling devices that transport heat are indispensable, and further improvements in the cooling capacity of these cooling devices are required in the future as well as reduction in size and weight.

  Therefore, as described in (Patent Document 1), for example, as described in (Patent Document 1), as a heat receiver corresponding to miniaturization and high integration of semiconductor elements, a compact design is realized while reducing pressure loss in the liquid flow path of liquid refrigerant. Possible heat receivers have been proposed.

  FIG. 10A shows an exploded perspective view of the heat receiver described in (Patent Document 1), and FIG. 10B shows a partial cross-sectional view of the heat receiver described in (Patent Document 1). A plurality of grooves 102a and 102b are formed on both main surfaces of a rectangular intermediate plate 101 of about 15 mm by a known means such as chemical etching, for example, with a width of about 50 μm and a depth of about 300 μm. Are formed in parallel to form a plurality of heat radiation fins 107a and 107b.

  Here, the peripheral portion of the intermediate plate 101 is left, and the top surfaces of the fins 107a and 107b are made to be lower in height than the peripheral portion.

  Cover plates 103a and 103b are attached to both main surfaces of the intermediate plate 101 so as to cover the entire surface thereof, and these cover plates 103a and 103b constitute a supply port and a discharge port for liquid refrigerant. Through-holes 104a and 105a and 104b and 105b are provided on both main surfaces, respectively. A semiconductor element 106 is provided on the main surface opposite to the main surface connected to the middle plate 101 of the cover plate 103a.

  For example, by applying the through hole 104a of the cover plate 103a and the through hole 105b of the cover plate 103b as the liquid refrigerant supply port, and applying the remaining through holes 105a and 104b as the liquid refrigerant discharge port, The liquid refrigerant can be caused to flow in an opposite flow through the liquid flow path of the liquid refrigerant provided between both the main surfaces and the cover plates 103a and 103b, and thereby the temperature gradient in the flow direction of the liquid refrigerant is increased. It is relaxed and it is possible to average the temperature distribution in the heat receiver.

  Further, as shown in FIG. 10B, a certain gap is provided between the top surfaces of the heat radiation fins 107a and 107b and the cover plates 103a and 103b, and a minute liquid refrigerant constituted by a plurality of grooves 102a and 102b. By connecting the liquid flow paths and enlarging the flow area, the pressure loss when the liquid refrigerant flows is reduced. As a result, the liquid refrigerant smoothly flows in the liquid flow path of the liquid refrigerant provided in the heat receiver, and a sufficient cooling effect is exhibited, so that the semiconductor element 106 to be cooled is destroyed. Reliability is improved.

  In this figure, the semiconductor element 106 is provided only on one cover plate 103a, but the semiconductor element 106 is also provided on the main surface opposite to the main surface connected to the middle plate 101 of the other cover plate 103b. And may be cooled at the same time.

On the other hand, as another heat receiver structure with improved cooling performance, for example, as in (Patent Document 2), the heat of a heating element such as a semiconductor element thermally connected to one outer surface of the heat receiver, The heat received from the heating element is efficiently radiated to the liquid refrigerant flowing inside the heat receiver by conducting heat to a plurality of plate-shaped heat sink fins and rod-shaped heat sink fins formed on the inner surface of the heat receiver Possible structures have also been proposed.
JP-A-6-326226 JP 2004-22914 A

  However, in the heat receiver of (Patent Document 1) described above, it is easy to make the heat receiver itself thin and compact, but separate liquid flow paths for liquid refrigerant are formed on both main surfaces of the intermediate plate. Therefore, since it is necessary to provide the supply port and the discharge port of the liquid refrigerant for each liquid flow path, there is a problem that the structure of the liquid circulation path connected to the heat receiver becomes more complicated.

  In addition, the surface on the opposite side of the heat receiving surface that is thermally connected to the heating element and has the highest temperature has a small contact area with the liquid refrigerant flowing through the inside, and the effective contact area with the liquid refrigerant is small. From the heat-receiving surface of the heating element to both main surfaces of the intermediate plate on which a plurality of heat-dissipating fins are formed, a long heat conduction path through the peripheral edge increases the thermal resistance, so efficient and sufficient heat dissipation There was also a problem that it was difficult to perform.

  Furthermore, in the heat receiver of (Patent Document 2), a plurality of radiating fins are formed on the surface opposite to the heat receiving surface where the heating element is thermally connected and the temperature becomes highest. Although the conduction path is shortened and more efficient heat dissipation is possible, there is a problem that sufficient cooling performance cannot be obtained when dealing with a heating element with a large calorific value because the heat dissipation fins have a simple shape. It was.

  On the other hand, with the reduction in thickness and weight of electronic devices equipped with such a cooling device equipped with a heat receiver, it is naturally necessary to reduce the size of the heat receiver. Contrary to narrowing the space between the flat fins to increase the contact area between the fins, the liquid flow path of the liquid refrigerant becomes smaller, so the pressure loss increases and the flow rate of the circulating liquid refrigerant decreases. As a result, there is a problem that the cooling performance is lowered.

  The present invention solves such a conventional problem, improves the structure of the heat receiver, forms micro fins on the contact surface with the liquid refrigerant flowing through the liquid flow path in the gap of the heat radiating fins, and the liquid Not only can the stirring effect be obtained by forcing the refrigerant against the micro fins to forcibly generate micro turbulence, but the micro fins between the flat radiating fins also increase the contact area with the liquid refrigerant. Therefore, an object of the present invention is to provide a heat receiver that can easily improve the cooling performance even with a small liquid refrigerant flow rate and can easily cope with downsizing.

  In order to achieve the above object, a heat receiver according to the present invention is a heat receiver that connects a pair of liquid circulation paths and allows a liquid refrigerant to flow inside, and has one surface that is thermally connected to a heating element. And the other surface has a heat receiving plate formed with a plurality of heat dissipating fins, and the heat receiving plate accommodates the heat dissipating fins, and the space with the heat receiving plate forms part of the flow path of the liquid refrigerant. The main feature is that a plurality of micro fins are formed on the contact surface of the radiating fin with the liquid refrigerant.

  According to the heat receiver of the present invention, the heat exchange with the liquid refrigerant is promoted, the cooling performance can be easily improved even with a small flow rate of the liquid refrigerant, and it is possible to easily cope with downsizing.

  The invention according to claim 1 of the present invention is a heat receiver that connects a pair of liquid circulation paths and allows a liquid refrigerant to flow therein, and has one surface having a heat receiving surface that is thermally connected to a heating element. The surface includes a heat receiving plate in which a plurality of radiating fins are formed, and a casing in which the heat receiving plate is combined so as to accommodate the radiating fins, and a space in which the space with the heat receiving plate forms part of the flow path of the liquid refrigerant, By forming a plurality of micro fins on the contact surface of the radiating fin with the liquid refrigerant, the radiating fin is formed on the surface opposite to the heat receiving surface where the heating element is first thermally connected and the temperature is highest. Since the heat conduction path from the heating element to the radiation fin is shortened and the thermal resistance is reduced, the heat of the heating element can be more efficiently transferred to the liquid refrigerant flowing through the liquid flow path between the radiation fins.

  In addition, by forming a plurality of micro fins on the contact surface of the radiating fin with the liquid refrigerant, the liquid refrigerant flowing through the liquid flow path between the radiating fins collides with the micro fin to forcibly generate a minute turbulent flow. Not only can the agitation / separation action of the laminar boundary layer with a small amount of heat transfer be obtained, but the micro fins between the flat radiating fins will also increase the contact area with the liquid refrigerant. Exchange can be promoted, and the cooling performance can be easily improved even with a small liquid refrigerant flow rate, and a heat receiver that can easily cope with downsizing can be provided.

  The invention according to claim 2 of the present invention is an invention dependent on the invention according to claim 1, and is a refrigerant that communicates with the suction passage located on the suction side of the liquid circulation passage and supplies the liquid refrigerant in the extending direction of the radiation fins. A heat receiver having a supply path, wherein the liquid refrigerant is supplied in the extending direction of the radiation fins via a refrigerant supply path communicating with the suction path located on the suction side of the liquid circulation path. Liquid refrigerant with a uniform flow rate can be fed into the liquid flow path between the plurality of heat radiating fins and substantially parallel to the heat radiating fins. A liquid refrigerant can be stably flowed in, and cooling performance can be improved.

  A third aspect of the present invention is a heat receiver according to the first aspect of the present invention, characterized in that the microfin is formed in a flat plate shape and extends in a direction in which the liquid refrigerant flows. The liquid refrigerant flowing through the liquid flow path between the fins collides with the flat micro fins to forcibly generate minute turbulent flow, so that the laminar boundary layer with a small heat transfer can be stirred and separated. In addition, since the micro fin formed on the contact surface of the radiating fin with the liquid refrigerant is also flat, the contact area with the liquid refrigerant is greatly increased, so heat exchange with the liquid refrigerant is promoted and reduced. The cooling performance can be easily improved even with the flow rate of the liquid refrigerant.

  The invention described in claim 4 of the present invention is an invention dependent on the invention described in claim 1, characterized in that the micro fins are pin-shaped and arranged in a zigzag pattern in the direction in which the liquid refrigerant flows. The micro fins formed on the contact surface of the radiating fins with the liquid refrigerant not only increase the contact area with the liquid refrigerant, but also the pin-shaped micro fins are arranged in a staggered manner in the direction in which the liquid refrigerant flows. Since the liquid refrigerant flowing in the liquid flow path of the gap collides with the pin-shaped micro fins to forcibly generate minute turbulent flow, the agitation / separation action of the laminar boundary layer with a small heat transfer amount can be obtained. Heat exchange with the refrigerant is promoted, and the cooling performance can be easily improved even with a small liquid refrigerant flow rate.

  The invention according to claim 5 of the present invention is an invention dependent on the invention according to claim 3 or 4 and is characterized in that the total height of the microfins is different from each other, for example, adjacent heat receivers. If the height of the radiating fins is set to a height that allows the predetermined micro fins to be brought into contact with each other, direct thermal conductivity between the micro fins can be obtained, and the heat conduction path from the heating element to the radiating fin becomes shorter. Since the thermal resistance is reduced, good thermal conductivity with the heat receiving plate can be ensured even if the radiating fins are arranged so as to be substantially parallel to the heat receiving plate.

  Alternatively, if the total height of the micro fins is partially reduced, the pressure loss of the liquid refrigerant flowing inside the heat receiver can be reduced. Therefore, the flow rate of the liquid refrigerant can be reduced even when cooling a heating element that generates a large amount of heat. It can be increased easily.

  The invention described in claim 6 of the present invention is an invention dependent on the invention described in claim 1, characterized in that the micro fin is formed by etching, and the flat radiating fin is thinned. In addition, since fine microfins can be easily formed on the surface, the pitch of the radiating fins can be further reduced, the contact area with the liquid refrigerant can be increased, and the cooling performance can be improved.

  In addition, since the micro fins are formed by etching instead of machining or cutting, it is easy to select the shape, height, size, arrangement, etc. of the micro fins as appropriate depending on the structure of the heat receiver and the cooling effect. The mass productivity is improved.

  The invention according to claim 7 of the present invention is an invention dependent on the invention according to claim 1, and is a heat receiver characterized in that the radiation fins are joined to each other to form a laminated structure. Even if the heat sink is made into a laminated structure in which a plurality of them are arranged substantially in parallel, it becomes possible to easily form heat radiation fins on the surface opposite to the heat receiving surface of the heat receiving plate, and the heat radiation fins are joined to each other. Therefore, thermal conductivity is also good.

  The invention according to claim 8 of the present invention is an invention dependent on the invention according to claim 7, wherein a laminated structure in which ends of the radiating fins located substantially parallel to the liquid refrigerant flow direction are joined to each other. The ends of the radiating fins are joined to each other so that a liquid flow path for liquid refrigerant can be formed in the gap, and the laminated structure is open only on the liquid supply side and the liquid discharge side. As a result of the sealed structure, there is little detouring or stagnation of the liquid refrigerant in the heat receiver, and it can flow stably in the liquid flow path, so that heat exchange can be performed efficiently and the cooling performance can be further improved. .

  The invention according to claim 9 of the present invention is an invention dependent on the invention according to claim 1, characterized in that the heat radiating fins are arranged substantially perpendicular to the heat receiving plate, and the heat receiving element comprises: Since the heat transfer path to the heat radiating fin can be set to the shortest distance, the thermal resistance between the heat receiving surface and the heat radiating fin is reduced, and the surface temperature of the heat radiating fin can be made closer to the surface temperature of the heating element in contact with the heat receiving surface. Therefore, heat exchange is performed efficiently and cooling performance is improved.

  The invention described in claim 10 of the present invention is an invention dependent on the invention described in claim 1, characterized in that the heat dissipating fins are arranged substantially parallel to the heat receiving plate. Since the liquid flow path formed by the gap is arranged substantially in parallel with the heat receiving plate, even if a large mounting space is not obtained in the direction of the side where the heat receiving device is mounted, the heat receiving device needs to be thinned. The heat dissipating fins can be easily expanded to increase the contact area with the liquid refrigerant, and the cooling performance can be improved.

  The invention described in claim 11 of the present invention is an invention dependent on the invention described in claim 1, and is provided with a centrifugal pump for circulating a liquid refrigerant in the heat receiver. Since it has a pump function to circulate the liquid refrigerant in the liquid circulation path, the cooling device provided with this heat receiver does not require a separate pump, and the whole device can be easily reduced in size and weight. .

  According to a twelfth aspect of the present invention, there is provided a cooling device comprising the heat receiver according to the first aspect, wherein the heat receiver of the cooling device has a microscopic surface on the contact surface of the radiating fin with the liquid refrigerant. By forming the fins, the liquid refrigerant flowing through the liquid flow path between the radiating fins collides with the micro fins to forcibly generate a minute turbulent flow, thereby agitating / separating the laminar boundary layer with a small heat transfer amount. As a result, the micro fins between the flat radiating fins also increase the contact area with the liquid refrigerant, so that heat exchange with the liquid refrigerant is promoted and the cooling performance can be easily improved even with a small liquid refrigerant flow rate. Therefore, it is easy to cope with the reduction in size and weight.

  According to a thirteenth aspect of the present invention, a heat receiving plate having a heat receiving surface thermally connected to a heating element on one surface and a plurality of heat dissipating fins formed on the other surface, and the heat receiving fins are accommodated in the heat receiving plate. And a heat receiving plate comprising a casing whose space with the heat receiving plate forms part of the flow path of the liquid refrigerant, wherein a plurality of micro fins are formed on a contact surface of the heat radiating fin with the liquid refrigerant. The method includes a first step of forming micro fins on the surface of the radiation fin by etching, a second step of joining the radiation fins to each other to form a laminated structure, and a second step of joining the laminated structure to the heat receiving plate. A method of manufacturing a heat receiver having three processes, which can easily form fine micro fins on the surface of a thinned heat radiation fin, and is difficult to manufacture by conventional machining or cutting. Thin flat fins Also it becomes possible to cope with by arranging a narrow pitch turned into improves mass productivity of the heat receiver having improved cooling performance becomes possible inexpensive manufacture.

  Embodiments of the present invention will be described below with reference to the drawings. In each drawing, the heat receiving surface side is described as the lower side and the casing side as the upper side.

Example 1
1 to 4, FIG. 1 is a partially cutaway perspective view of a heat receiver in Embodiment 1 of the present invention, FIG. 2 is a cross-sectional view taken along line AA in FIG. 1, and FIG. 3 is an embodiment of the present invention. 4 (a) is a cross-sectional view taken along line BB in FIG. 3, FIG. 4 (b) is a cross-sectional view taken along line CC in FIG. 3, and FIG. FIG. 5A is a cross-sectional view taken along line B-B of a modification example in which the micro fins in the first embodiment of the present invention have a pin shape, and FIG. 5B shows a modification example in which the micro fins in the first embodiment of the present invention have a pin shape. It is line CC sectional drawing of this.

  First, the main configuration of the heat receiver 1 including the centrifugal pump will be described with reference to FIG. 1, but the other components other than the heat receiving plate 2, the heat radiating fins 3, and the casing 4 will be described later and will be omitted. Illustrated.

  The bottom surface of the heat receiver 1 having a substantially cylindrical outer shape is in contact with a heating element (not shown) such as a semiconductor element so that a good thermal connection can be obtained via a heat receiving surface described later. The heat receiving plate 2 is made of a metal material having a good thermal conductivity such as a plurality of plate-like plates so that a liquid flow path is formed in the direction indicated by the arrow on the upper surface of the heat receiving plate 2. The radiating fins 3 are formed in parallel in the left-right direction at a predetermined pitch.

  And the casing 4 manufactured by resin molding, such as polyphenylene sulfide (PPS) and polyphenylene ether (PPE), is combined so that the radiation fin 3 formed in the upper surface of the heat receiving plate 2 may be accommodated. Constitutes a part of the liquid flow path of the liquid refrigerant that flows inside the heat receiver 1.

  On the other hand, the side wall of the casing 4 is provided with a suction path 5 and a discharge path 6 that connect a pair of liquid circulation paths of a cooling device (not shown), and the liquid refrigerant that has flowed in from the suction path 5 as indicated by an arrow is After the heat exchange with the radiating fins 3 while flowing inside the heat receiver 1, the heat flows out of the heat receiver 1 from the discharge path 6 as indicated by the arrows.

  Next, based on FIG. 2, the internal structure of the heat receiver 1 provided with the centrifugal pump is demonstrated in detail.

  In FIG. 2, an impeller 7 constituting a centrifugal pump is pivotally supported at a substantially central portion of the heat receiver 1, a plurality of open-type blades 7 a are erected on the surface of the impeller 7, and a magnet rotor 8 is provided. It is provided on the inner peripheral side of the impeller 7. Here, the impeller 7 may be configured separately from the magnet rotor 8, but it is preferable that the impeller 7 be an integrated impeller 7 that is magnetized in a portion that becomes the magnet rotor 8.

  When the impeller 7 rotates in the liquid refrigerant, the pressure of the liquid refrigerant on the outer peripheral side of the vane 7a is higher at the peripheral edge of the vane 7a than at the inlet of the impeller 7 (the central portion indicated by K in FIG. 1). Moreover, since the pressure at the inlet of the impeller 7 is substantially the same as the pressure on the back side of the impeller 7 communicated by the small hole 7b, the liquid refrigerant passes through the back surface of the impeller 7 and passes through the small hole 7b to enter the small amount. Reflux. Thereby, compared with the case where there is no small hole 7b, thrust force is reduced to the impeller 7, and rotation of the impeller 7 becomes smoother.

  The centrifugal pump of the heat receiver 1 is small and has a size that is several tenths or one hundredth of that of a general centrifugal pump. As an example, the thickness is 3 mm. It is a pump having a diameter of about 50 mm, a representative dimension in the radial direction of 10 mm to 100 mm, a rotation speed of 1000 rpm to 8000 rpm, and a head of about 0.5 m to 10 m.

  Next, a stator 9 is provided on the inner peripheral side of the magnet rotor 8, a coil 10 for generating a magnetic field is wound around the stator 9, and an electric circuit for passing a current through the coil 5 is mounted on the circuit board 11. Here, the stator 9 is preferably formed by laminating a plurality of silicon steel plates in order to reduce eddy current loss, and a copper wire with an insulating film is suitable as the coil 10. The number of turns is optimized in view of the power supply voltage used and the line factor.

  Although not shown, a Hall element for detecting the rotational position of the magnet rotor 8, a current direction switching transistor and a diode are mounted on the circuit board 11.

  In addition, the casing 4 accommodates the impeller 7 and at the same time guides the liquid refrigerant given centrifugal force by the impeller 7 in the direction of the discharge path 6 connected to the side surface thereof. Connected in the same direction on the side.

  Furthermore, since the casing 4 has a complicated shape and requires a certain degree of heat resistance, it is more suitable to manufacture by resin molding such as polyphenylene sulfide (PPS) and polyphenylene ether (PPE).

  On the other hand, it is not preferable to manufacture the casing 4 from a metal material because eddy current loss occurs due to magnetic flux fluctuations generated by a magnetic circuit such as the stator 9.

  Then, in the pump chamber 12, the liquid refrigerant given the propulsive force by the open type blade 7 a is guided to the discharge path 6.

  On the other hand, the heat receiving plate 2 is in direct contact with a heating element 13 such as a semiconductor element indicated by a two-dot chain line through a heat conductive grease or the like (not shown), so that its surface is made as flat as possible to increase the heat Using a metal material such as copper, copper alloy, and aluminum having good heat dissipation with conductivity, it is manufactured by casting, forging, machining, or a combination of these methods.

  Further, since the heat receiving plate 2 is made of a metal material having good thermal conductivity, its rigidity is increased, and even if the heat receiving device 1 is pressed toward the heating element 13 with a strong force, the heat receiving plate 2 is affected by the stress. The deformation of the heat receiving plate 2 can be suppressed, and the formation of a gap between the heating element 13 and the heat receiving surface 2b can be prevented. And if it can press to the heat generating body 13 with the strong force, the heat conductive grease (not shown) apply | coated between the heat generating body 13 and the heat receiving surface 2b can be extended thinly, and, thereby, in heat conductive grease The thermal resistance can be reduced, and the parts can be prevented from coming off when the product is shaken or dropped.

  Further, the casing 4 is combined with the flange 2a formed on the outer peripheral portion of the heat receiving plate 2 while being in contact with each other, and a predetermined space such as a pump chamber 12 that is an internal space of the casing 4 covers a part of the liquid flow path of the liquid refrigerant. Constitute.

  Here, a heat receiving surface 2b which is a contact surface with a heating element 13 such as a semiconductor element indicated by a two-dot chain line is provided at a lower portion of the heat receiving plate 2, and a plurality of heat dissipation protrusions are provided on the opposite surface. The heat radiating fins 3 are arranged, and the heat radiating fins 3 perform heat exchange while contacting the liquid refrigerant flowing through the liquid flow path in the gap, and efficiently transfer the heat received from the heating element 13 to the liquid refrigerant.

  The flat radiating fin 3 can easily increase the radiating area and suppresses a large flow resistance against the liquid refrigerant passing through the liquid flow path in the gap of the radiating fin 3. Therefore, the pressure loss is small and a sufficient flow rate can be secured.

  Further, a plurality of flat micro fins 3 a are extended in the direction in which the liquid refrigerant flows on the contact surfaces of the plurality of radiating fins 3 with the liquid refrigerant, and the liquid refrigerant flows through the liquid flow path in the gap between the radiating fins 3. Is caused to collide with the flat micro fins 3a to forcibly generate a minute turbulent flow, so that the laminar boundary layer with a small amount of heat transfer can be agitated / separated, and the heat radiation fin 3 can be separated from the liquid refrigerant. Since the micro fins 3a formed on the contact surface are also flat, the contact area with the liquid refrigerant is also greatly increased, so heat exchange with the liquid refrigerant is promoted, and cooling is easy even with a small liquid refrigerant flow rate. Performance can be improved.

  The plurality of radiating fins 3 extend so as to be substantially parallel to the direction of the circulating heat transfer chamber 15 from the refrigerant supply path 14, that is, the direction in which the liquid refrigerant flows, and the refrigerant communicated with the suction path 5. Liquid refrigerant is supplied in the extending direction of the radiation fins 3 via the supply path 14, and is substantially parallel to the radiation fins 3 and has a uniform flow rate relative to the liquid flow paths in the gaps between the plurality of radiation fins 3. Therefore, the liquid refrigerant can be stably flowed into the liquid flow path despite the simple structure, and the cooling performance can be improved.

  Further, the flat disc-shaped heat receiving plate 2 has a structure that easily transfers the heat received from the heat receiving surface 2b to the heat radiating fins 3 formed on the surface opposite to the heat receiving surface 2b. Are accommodated in the casing 4 and arranged substantially perpendicular to the heat receiving plate 2, the heat transfer path from the heat receiving surface 2 b to the heat radiating fins 3 can be set to the shortest distance.

  That is, the short heat transfer path means that the thermal resistance between the heat receiving surface 2b and the heat radiating fin 3 is small, and the surface temperature of the heat radiating fin 3 depends on the surface temperature of the heating element 13 in contact with the heat receiving surface 2b. Since they can be brought close to each other, heat exchange is efficiently performed over a wide area while in contact with the liquid refrigerant, thereby improving the cooling performance.

  On the other hand, the liquid refrigerant that has flowed in from the suction passage 5 as shown by an arrow passes through the refrigerant supply passage 14 through the liquid passages in the gaps between the plurality of radiating fins 3 and flows into the circulation heat transfer chamber 15. While colliding with the cylindrical wall 16 a of the partition wall member 16, the flow is divided in two directions left and right with respect to the traveling direction, and finally mixed with the subsequent liquid refrigerant in the circumferential heat transfer chamber 15. It passes through the through hole 16b formed on the chamber 15 side and is sent out to the pump chamber 12.

  Here, the micro fin 3a is not formed in a part of the radiating fin 3 on the side of the circulating heat transfer chamber 15 because the flow resistance of the part is reduced and the liquid refrigerant is directly penetrated between the radiating fins 3. This is intended to facilitate delivery through the hole 16b to the pump chamber 12 side.

  That is, as described above, the heat received from the heating element 13 is transferred until the liquid refrigerant flows into the central portion of the heat receiving plate 2, passes through the through hole 16 b of the partition wall member 16, and is sent to the pump chamber 12 side. Since the surface of the radiating fin 3 heated to a high temperature comes into contact with the liquid refrigerant circulated and driven by the rotational motion of the impeller 7, the liquid refrigerant can efficiently exchange heat with the radiating fin 3.

  The radiating fin 3 has a flat plate shape and extends from the refrigerant supply path 14 toward the circulation heat transfer chamber 15 so as to be substantially parallel to the direction in which the liquid refrigerant flows. The contact area with the refrigerant can be greatly increased to increase the heat exchange efficiency.

  Here, the structure of the heat receiver 1 will be further described with reference to FIG. 2. A shaft 17 made of a material such as stainless steel having high corrosion resistance by insert molding is integrally fixed to the center of the casing 4. Is pivotally supported.

  Further, the above-described dish-shaped partition member 16 is fitted with the casing 4 to form the pump chamber 12, and a sealing member such as an O-ring sandwiched between the casing 4 and the flange portion 2 a of the heat receiving plate 2. 18 prevents liquid refrigerant from leaking from between the casing 4 and the heat receiving plate 2, and the circulating heat transfer chamber 15 is a closed circuit formed between the partition wall member 16 and the heat receiving plate 2.

  The partition member 16 is also complicated in shape like the casing 4 and requires heat resistance. Therefore, the partition member 16 is preferably manufactured by resin molding such as polyphenylene sulfide (PPS) or polyphenylene ether (PPE).

  When assembling the heat receiver 1 described above, first, the impeller 7 is inserted into the shaft 17 that is integrally fixed to the casing 4 by insert molding after the partition member 16 is mounted. Next, the heat receiving plate 2 is fitted into the casing 4 and fixed using screws or the like (not shown).

  On the other hand, the coil 10 is wound around the stator 9 in a separate process, and the circuit board 11 on which electronic components for rotating the impeller 7 are mounted is attached to the stator 9. After this assembly is inserted into the recess of the casing 4, a filler (not shown) is poured, and then the filler is cured using a thermostatic bath or the like.

  The reason for using the filler is to dissipate the electronic components mounted on the circuit board 11 and to improve reliability by preventing direct contact with the circuit board 11 even if liquid refrigerant leaks. As such a filler, an epoxy-based potting agent is preferable.

  Next, the operation of the centrifugal pump provided in the heat receiver 1 will be described. First, when the circuit board 11 is operated and an alternating magnetic field is generated in the stator 9, the impeller 7 integrated with the magnet rotor 8 is rotated by the alternating magnetic field, giving momentum to the liquid refrigerant and causing the central portion to have a negative pressure. Become.

  As a result, the liquid refrigerant flows from the suction passage 5, passes through the suction communication port 16 d, and flows into the refrigerant supply passage 14 that is a space sandwiched between the heat receiving plate 2 and the partition wall member 16. The inflowing liquid refrigerant efficiently takes away the heat of the high-temperature radiating fins 3 located immediately above the heating element 13.

  Thereafter, the liquid refrigerant flows along the radiating fins 3, reaches the outflow side end thereof, and collides with the cylindrical wall 16 a of the partition wall member 16 in the circulating heat transfer chamber 15, in two directions left and right with respect to the traveling direction. To be diverted to The diverted liquid refrigerant circulates in each of the circulation heat transfer chambers 15 and is sucked into the center of the radiating fin 3 again because the inlet of the impeller 7 (the central portion indicated by K in FIG. 1) has a negative pressure. Then, the partition wall member 16 is sent out to the pump chamber 12 through a through hole 16b formed on the circumferential heat transfer chamber 15 side.

  The liquid refrigerant sent to the pump chamber 12 is finally given a momentum that becomes a thrust in the centrifugal direction by the rotational motion of the impeller 7, and is guided to the outer peripheral portion of the pump chamber 12, and is discharged as indicated by an arrow. It flows out of the road 6.

  As described above, the heat receiver 1 including the centrifugal pump according to the first embodiment has a function of transferring the received heat to the liquid refrigerant from the surfaces of the heat receiving plate 2 and the heat radiating fins 3, and between the casing 4 and the heat receiving plate 2. Since the partition member 16 is provided at a predetermined position between them and has a pump function of rotating the impeller 7, the cooling device provided with the heat receiver 1 has a separate pump for circulating the liquid refrigerant. Since it is not necessary, the entire apparatus can be easily reduced in size and weight.

  Next, the radiation fin 3 formed on the upper surface of the heat receiving plate 2 will be described in detail with reference to FIGS. First, as shown in FIG. 3, a rectangular recess 2 c that is slightly depressed is formed in the approximate center of the upper surface of the flat disk-shaped heat receiving plate 2, and a plurality of heat radiation fins 3 are formed on the inner surface of the recess 2 c. The structured laminated structure 19 is joined by a brazing material 20.

  For example, when a metal plate with good thermal conductivity such as copper, copper alloy, aluminum, silver, or the like having a plate thickness in the range of 0.1 mm to 1.0 mm is selected as the laminated structure 19, the liquid refrigerant flows in advance. A plurality of thinned pieces having a thickness of 0.05 mm to 0.9 mm in the thickness direction by etching leaving a region in which the end portions in the vertical direction and the microfins 3a are formed substantially parallel to each other and being arranged in a narrow pitch, The end portions in the vertical direction are manufactured by joining each other using a brazing material 20.

  That is, the micro fin 3a is formed by etching on the contact surface of the radiating fin 3 with the liquid refrigerant. Even if the flat radiating fin 3 is thinned, the fine micro fin 3a is easily formed on the surface. Therefore, the pitch of the radiating fins 3 can be further narrowed, the contact area with the liquid refrigerant can be increased, and the cooling performance can be improved.

  Furthermore, since the micro fins 3a are formed by etching rather than machining or cutting, the shape, height, size, arrangement, etc. of the micro fins 3a can be appropriately selected depending on the structure of the heat receiver 1 and the cooling effect. That's fine.

  In this embodiment, the micro fins 3a are formed by etching suitable for fine processing. However, as other processing methods, wire electric discharge processing, laser processing, powder sintering, precision forging, etc. are considered in consideration of mass productivity and cost. May be selected.

  Next, FIG. 4A is a cross-sectional view taken along line BB in FIG. 3, each of which constitutes a laminated structure 19 joined to the inner surface of the concave portion 2 c at the substantially center of the heat receiving plate 2 with a brazing material 20. The heat dissipating fins 3 are arranged at equal intervals so that the upper and lower ends are joined to each other by the brazing material 20 and are substantially perpendicular to the heat receiving plate 2, and the heat received from the heat receiving surface 2 b is transferred to the heat dissipating fins 3. The heat transfer path is set to be the shortest distance.

  Accordingly, the thermal resistance between the heat receiving surface 2b and the heat radiating fin 3 is reduced, and the surface temperature of the heat radiating fin 3 can be brought closer to the surface temperature of the heating element 13 in contact with the heat receiving surface 2b. Cooling performance is improved.

  Further, the gaps 21 between the plurality of radiating fins 3 constituting the laminated structure 19 correspond to portions removed by etching, and the heat between the radiating fins 3 and the liquid refrigerant when the liquid refrigerant flows through the narrow gaps 21. A plurality of plate-like micro fins 3a are formed on the contact surface with the liquid refrigerant, and the liquid refrigerant flowing in the liquid flow path of the gap 21 between the heat radiating fins 3 collides with the micro fins 3a so as to be minute. By forcibly generating a turbulent flow, not only can the laminar boundary layer with a small amount of heat transfer be stirred and separated, but the micro fins 3a between the plurality of heat radiating fins 3 can reduce the contact area with the liquid refrigerant. Since this also increases, heat exchange with the liquid refrigerant is promoted, and the cooling performance can be easily improved even with a small liquid refrigerant flow rate.

  Furthermore, since the upper end 3b and the lower end 3c, which are positioned substantially parallel to the direction in which the liquid refrigerant flows in the heat radiating fins 3, are joined to each other by the brazing material 20, the gap 21 The liquid flow path of the liquid refrigerant can be formed on the laminated structure 19, and the laminated structure 19 has a sealed structure in which only the liquid supply side and the liquid discharge side are opened, and the liquid refrigerant has little detour and stagnation in the heat receiver 1. The inside of the flow path can be stably flowed, heat exchange can be performed efficiently, and the cooling performance can be further improved.

  On the other hand, FIG. 4B is a cross-sectional view taken along the line CC in FIG. 3, and the direction in which the liquid refrigerant flows through the flat micro fins 3a indicated by arrows, that is, from the liquid supply side end 3d to the liquid discharge side. By extending the liquid refrigerant flowing in the liquid flow path of the gap 21 between the heat radiating fins 3 against the plurality of flat micro fins 3a and forcibly generating minute turbulent flow. Not only can the agitation / separation action of the laminar boundary layer with a small amount of heat transfer be obtained, but the microfin 3a formed on the contact surface of the radiating fin 3 with the liquid refrigerant is also flat, so the contact area with the liquid refrigerant is reduced. Since this also greatly increases, heat exchange with the liquid refrigerant is promoted, and the cooling performance can be easily improved even with a small liquid refrigerant flow rate.

  Here, it is preferable that the micro fins 3a continuously extend from the liquid supply side end portion 3d to the liquid discharge side end portion 3e in the direction in which the liquid refrigerant flows, but the larger laminar boundary layer agitation / separation action When it is desired to obtain the microfin 3a, the microfin 3a may be intermittently formed in the direction in which the liquid refrigerant flows.

  Next, Fig.5 (a) is line BB sectional drawing of the modification which made the micro fin 3a of the heat receiver in Example 1 of this invention pin-shaped, and also in this case, narrow gap 21 is made into a liquid refrigerant. The heat exchange between the radiating fins 3 and the liquid refrigerant is performed by the flow of the liquid, and a plurality of pin-shaped micro fins 3a are formed on the contact surface with the liquid refrigerant, and the liquid flow in the gaps 21 of the radiating fins 3 is performed. The liquid refrigerant flowing through the path collides with the micro fins 3a to forcibly generate a minute turbulent flow, whereby not only a laminar boundary layer agitation / separation action with a small amount of heat transfer can be obtained, but also Since the micro fins 3a in between increase the contact area with the liquid refrigerant, heat exchange with the liquid refrigerant is promoted, and the cooling performance can be easily improved even with a small liquid refrigerant flow rate.

  Further, FIG. 5 (b) shows the micro fin 3a in a pin shape and indicated by an arrow as shown in the line CC cross-sectional view of a modified example in which the micro fin 3a in the first embodiment of the present invention has a pin shape. Since the liquid refrigerant is arranged in a zigzag manner in the flow direction, the micro fins 3a formed on the contact surface of the heat radiation fins 3 with the liquid refrigerant not only increase the contact area with the liquid refrigerant, but also the pin-shaped micro The fins 3a are arranged in a zigzag manner in the direction in which the liquid refrigerant flows, and the liquid refrigerant flowing through the liquid flow path in the gap 21 of the radiating fin 3 collides with the pin-shaped microfin 3a to forcibly generate a minute turbulent flow. Thus, the agitation / separation action of the laminar boundary layer having a small heat transfer amount can be obtained, so that heat exchange with the liquid refrigerant is promoted, and the cooling performance can be easily improved even with a small liquid refrigerant flow rate.

  In this embodiment, the plate-like or pin-like microfins 3a have been described, but the shape, height, size, arrangement, etc. may be appropriately selected depending on the structure of the heat receiver 1 and the cooling effect thereof, A shape in which flat plate-like and pin-like micro fins 3a are mixed may be used.

  Further, the shape of the microfin 3a is preferably a flat plate shape or a pin shape, but other shapes may be used as long as they have similar functions and effects such as a conical shape, a wing shape, a triangular shape, and a wave shape.

(Example 2)
6-7, FIG. 6A is a partially cutaway perspective view of the heat receiver in the second embodiment of the present invention, FIG. 6B is a sectional view taken along the line DD, and FIG. ) To (d) are line DD sectional views showing modifications of the micro fins of the heat receiver in the second embodiment of the present invention.

  First, the main configuration of the heat receiver 1 according to the second embodiment of the present invention will be described with reference to FIG. 6 (a). The same components as those described in the first embodiment are denoted by the same reference numerals. A part of the description is omitted.

  The bottom surface of the heat receiver 1 having a substantially rectangular parallelepiped shape is in contact with a heating element (not shown) such as a semiconductor element so that a good thermal connection can be obtained via a heat receiving surface 2b described later. The heat receiving plate 2 is made of a metal material having a good thermal conductivity such as a plurality of plate-like plates so that a liquid flow path is formed in the direction indicated by the arrow on the upper surface of the heat receiving plate 2. The radiating fins 3 are formed substantially parallel to each other at a predetermined pitch in the vertical direction.

  And, in order to accommodate the radiating fins 3 formed on the upper surface of the heat receiving plate 2, a casing 4 made of a metal material having a good thermal conductivity such as copper, copper alloy, and aluminum is combined. A space between the casing 4 and the heat receiving plate 2 constitutes a part of the liquid flow path of the liquid refrigerant that flows inside the heat receiver 1.

  On the other hand, a suction path 5 and a discharge path 6 that connect a pair of liquid circulation paths of a cooling device (not shown) are provided on both side walls of the casing 4, respectively, and flowed in from the suction path 5 as indicated by arrows. The liquid refrigerant flows out of the heat receiver 1 from the discharge path 6 as indicated by the arrow after performing heat exchange with the radiating fins 3 while flowing inside the heat receiver 1.

  Here, the plurality of radiating fins 3 are extended from the refrigerant supply path 14 so as to be substantially parallel to the direction of the refrigerant discharge path 22, and the radiating fins pass through the refrigerant supply path 14 communicating with the suction path 5. Since the liquid refrigerant is supplied in the extending direction of 3 and the liquid refrigerant is sent in a uniform flow rate to the liquid flow paths of the gaps 21 between the plurality of heat radiating fins 3 substantially parallel to the heat radiating fins 3, Regardless of the structure, there is little stagnation of the liquid refrigerant, and the liquid refrigerant can be stably flowed into the liquid flow path, so that the cooling performance can be improved.

  In addition, as shown in FIG. 6B, the heat dissipating fin 3 is composed of a brazing material 20 in which a laminated structure 19 composed of the heat dissipating fins 3 is formed in a substantially central recess 2 c on the upper surface of a flat rectangular heat receiving plate 2. It is joined.

  For example, when the laminated structure 19 is a metal plate having a good thermal conductivity such as copper, copper alloy, aluminum, or silver having a plate thickness in the range of 0.1 mm to 1.0 mm, as in the first embodiment. , Which has been thinned to a thickness of 0.05 mm to 0.9 mm in the thickness direction by etching with the left and right end portions positioned substantially parallel to the liquid refrigerant flowing direction and the region for forming the micro fins 3 a being left in advance. Are arranged at a narrow pitch, and the end portions in the left-right direction are joined to each other using a brazing material 20.

  That is, since the right end portion 3f and the left end portion 3g, which are positioned substantially parallel to the direction in which the liquid refrigerant flows in the heat radiating fins 3, are joined to each other by the brazing material 20, the laminated structure 19 is formed. The liquid flow path of the liquid refrigerant can be formed, and the laminated structure 19 has a sealed structure in which only the liquid supply side and the liquid discharge side are opened, and the liquid refrigerant has little detour and stagnation in the heat receiver 1. Since the inside of the passage can be stably flowed, heat exchange can be performed efficiently and the cooling performance can be further improved.

  Further, flat micro fins 3a are extended in the direction of flow of the liquid refrigerant by etching on the contact surface of the radiating fin 3 with the liquid refrigerant, and the liquid refrigerant flowing in the liquid flow path of the gap 21 of the radiating fin 3 is By causing the microfluid 3a to collide with the flat plate-like microfin 3a and forcibly generating a small turbulent flow, not only can the laminar boundary layer with a small heat transfer be stirred and separated, but also the radiating fin 3 can come into contact with the liquid refrigerant. Since the micro fins 3a formed on the surface are also flat, the contact area with the liquid refrigerant is greatly increased, so that heat exchange with the liquid refrigerant is promoted and the cooling performance can be easily achieved even with a small liquid refrigerant flow rate. Can be improved.

  Furthermore, it is preferable to form the micro fins 3a by etching instead of machining or cutting, and the shape, height, size, arrangement, etc. of the micro fins 3a are appropriately selected depending on the structure of the heat receiver 1 and the cooling effect. And is suitable for high-precision processing.

  In this embodiment, the micro fins 3a are formed by etching. However, as other processing methods, laser processing, powder sintering, precision forging, and the like may be selected in consideration of mass productivity and cost.

  Further, since the heat radiating fins 3 are accommodated in the casing 4 and arranged substantially parallel to the heat receiving plate 2, the liquid flow path formed by the gap 21 of the heat radiating fins 3 is also substantially parallel to the heat receiving plate 2. Even when a large mounting space cannot be obtained in the direction of the side where the container 1 is mounted and the heat receiver 1 needs to be thinned, the heat dissipating fins 3 can be easily enlarged to increase the contact area with the liquid refrigerant, The performance can be improved.

  Here, as shown in FIG. 6A, the micro fins 3a continuously extend in the direction in which the liquid refrigerant flows, that is, in the direction from the liquid supply side end 3d to the liquid discharge side end 3e. Although it is preferable, in order to obtain a larger laminar boundary layer stirring / separation action, the micro fins 3a may be formed intermittently in the direction in which the liquid refrigerant flows.

  Next, as shown in FIG. 7A, which is a line DD sectional view of a modification of the micro fin of the heat receiver in the second embodiment of the present invention, it is substantially parallel to the flow direction of the liquid refrigerant in the radiating fin 3. If the microfins 3a of the adjacent radiating fins 3 are abutted with each other in the same manner as the right end portion 3f and the left end portion 3g, the height is set so that they can be joined by the brazing material 20, and the microfins 3a directly The heat conduction path from the heating element (not shown) to the radiation fin 3 is shortened and the thermal resistance is reduced, so that the radiation fin 3 is arranged so as to be substantially parallel to the heat receiving plate 2. Even so, good thermal conductivity with the heat receiving plate 2 can be ensured.

  Further, as shown in FIG. 7B, if the total height of the micro fins 3a is set to different heights, the pressure loss of the liquid refrigerant flowing inside the heat receiver 1 can be reduced. The flow rate of the liquid refrigerant can be easily increased even when a large amount of the heating element is cooled.

  Furthermore, the flat micro fins 3a are arranged with the same width and different pitch as shown in FIG. 7C, or arranged with different widths as shown in FIG. 7D. Furthermore, when it is desired to obtain a larger laminar boundary layer agitation / separation action, the micro fins 3a may be formed intermittently in the direction in which the liquid refrigerant flows.

  The shape, height, size, arrangement, and the like of the micro fins 3a may be appropriately selected in consideration of the structure of the heat receiver 1, the cooling effect, and the like. The pin-shaped micro fins 3a are the same as in the first embodiment. Alternatively, a shape in which flat plate-like and pin-like micro fins 3a are mixed may be used.

  Further, the shape of the microfin 3a is preferably a flat plate shape or a pin shape, but other shapes may be used as long as they have similar functions and effects such as a conical shape, a wing shape, a triangular shape, and a wave shape.

  Next, FIGS. 8A to 8E are front views showing a method for manufacturing the heat receiving fins according to the second embodiment of the present invention, and a stepwise method for manufacturing the heat radiating fins 3 of the heat receiver 1 will be described with reference to FIG. Explained.

  First, FIG. 8A shows a state before etching of the heat radiation fins 3 having good thermal conductivity such as copper, copper alloy, aluminum, silver, etc. In order to arrange the heat radiation fins 3 at a narrow pitch, 0. A thin plate having a thickness of 1 to 1.0 mm is selected. Next, FIG. 8B shows a state after the photosensitive resist 23 is applied to a predetermined region on both surfaces located in the vertical direction of the heat radiation fin 3.

  FIG. 8C is a view showing a state after the first step of forming the micro fins 3a on the surface of the heat radiating fins 3 by etching. If the heat radiating fins 3 are, for example, copper or a copper alloy metal plate, A region where the solution of ferric chloride is sprayed and the resist 23 is not applied, that is, the right and left end portions 3f and 3g of the heat radiating fin 3 and the regions where the micro fins 3a are formed is left and up. Since the thickness of the heat radiating fin 3 is reduced to a thickness of 0.05 to 0.9 mm in the thickness direction evenly, predetermined micro fins 3 a are formed on the surface of the heat radiating fins 3.

  Further, FIG. 8D is a view showing a state after the second step in which the radiating fins 3 are joined to each other to form the laminated structure 19, and a plurality of radiating fins 3 in which predetermined micro fins 3a are formed by etching are shown. It is a laminated structure 19 in which the right end portion 3f and the left end portion 3g are joined to each other with a brazing material 20, and can be easily manufactured even if the radiating fins 3 are thinned. Since it is connected, the thermal conductivity is also good.

  Finally, FIG. 8 (e) is a diagram showing a state after the third step in which the laminated structure 19 is joined to the heat receiving plate 2. In the recess 2c on the surface opposite to the heat receiving surface 2b of the heat receiving plate 2, FIG. The laminated structure 19 is joined using the brazing material 20, and the right end portion 3 f and the left end portion 3 g that are positioned substantially parallel to the direction in which the liquid refrigerant flows in the radiating fin 3 are joined together by the brazing material 20. A liquid flow path of the liquid refrigerant can be formed in the gap 21 of the structure 19, and the laminated structure 19 has a sealed structure in which only the liquid supply side and the liquid discharge side are opened, and the liquid refrigerant in the heat receiver 1 is formed. Therefore, it is possible to stably flow in the liquid flow path, so that heat exchange is performed efficiently and cooling performance can be further improved.

  As described above, the method of manufacturing the heat receiver 1 according to the present invention includes a heat receiving surface 2b that is thermally connected to a heating element (not shown) on one surface, and a heat receiving surface in which a plurality of radiating fins 3 are formed on the other surface. The liquid refrigerant of the radiating fin 3 includes a plate 2 and a casing 4 which is combined so that the radiating fin 3 is accommodated in the heat receiving plate 2 and the space with the heat receiving plate 2 forms part of the flow path of the liquid refrigerant. A method of manufacturing the heat receiver 1 in which a plurality of micro fins 3a are formed on the contact surface with the first step of forming the micro fins 3a on the surface of the radiation fins 3 by etching, and joining the radiation fins 3 to each other. The second step of forming the laminated structure 19 and the third step of joining the laminated structure 19 to the heat receiving plate 2 are easily provided on the surface of the thinned heat radiation fin 3. In addition to conventional mechanical processing It is also possible to reduce the thickness of the flat plate-like fins 3 that were difficult to manufacture by cutting or to arrange them at a narrow pitch by etching, so that mass production of the heat receiver 1 with improved cooling performance is improved and inexpensive. Manufacturing becomes possible.

  In the above description, the brazing material 20 for joining the radiation fins 3 to each other and the brazing material 20 for joining the radiation fins 3 and the heat receiving plate 2 in the laminated structure 19 include those of the radiation fins 3 and the heat receiving plate 2. When copper or copper alloy is used as the metal material, silver, copper, gold, platinum, nickel, etc. with good thermal conductivity are desirable, but other metal brazing materials and solder may be used, and thermal conductivity, productivity, The price may be selected as appropriate.

  Furthermore, as long as sufficient thermal conductivity is obtained, other methods such as resistance welding, laser welding, and caulking other than brazing as in the present embodiment may be used for joining.

(Example 3)
FIG. 9 is an overall configuration diagram in which the cooling device according to the third embodiment of the present invention is mounted on a notebook PC.

  Here, a cooling device is mounted inside a casing 24 of a notebook PC, which is an electronic device, and is described in the first embodiment that receives heat by contacting a heating element 13 such as an MPU under a keyboard 25 of the notebook PC. A heat receiver 1 having a centrifugal pump is mounted. The heating element 13 is mounted on a substrate 26, and a radiator 27 that dissipates the heat of the liquid refrigerant received from the heating element 13 to the outside is disposed on the back surface (back side) of the notebook PC display. Both ends of 28 are connected to the heat receiver 1 and the radiator 27, respectively, and the liquid refrigerant circulates in the closed circuit.

  As the liquid refrigerant, an antifreeze solution such as an ethylene glycol aqueous solution or a propylene glycol aqueous solution is appropriate, and since copper, copper alloy, or the like is used as the material of the heat receiving plate 2, it is desirable to add an anticorrosive additive.

  On the other hand, the radiator 27 is made of a thin plate material such as copper, copper alloy, and aluminum having a high thermal conductivity and good heat dissipation, and a liquid flow path and a reserve tank for liquid refrigerant are formed therein. The pair of liquid circulation paths 28 are made of a rubber tube such as a rubber having flexibility and a low gas permeability, for example, butyl rubber, in order to ensure flexibility in piping layout.

  Further, a fan device may be separately provided for the purpose of forcibly applying air to the radiator 27 to improve the cooling effect.

  Therefore, a pair of liquid circulation paths 28 are connected to the heat receiver 1 of this cooling device, and the liquid refrigerant flows inside, and as described in the first embodiment, the surface of the radiating fin 3 that contacts the liquid refrigerant is microscopic. Agitating a laminar boundary layer with a small amount of heat transfer by forming a fin 3a and forcibly generating a small turbulent flow by colliding the liquid refrigerant flowing in the liquid flow path of the gap 21 of the heat radiating fin 3 with the micro fin 3a.・ Since the peeling action is obtained and the micro fins 3a between the flat radiating fins 3 also increase the contact area with the liquid refrigerant, heat exchange with the liquid refrigerant is promoted and even a small liquid refrigerant flow rate is easy. Cooling performance can be improved.

  In addition, since the heat receiver 1 of the present embodiment also has a pump function, a separate pump is not required, and a reduction in size and weight of the entire casing 24 of the notebook PC can be easily realized.

  The present invention can be applied to a cooling device that cools a heating element mounted on an electronic device by circulation of a liquid refrigerant.

The partial notch perspective view of the heat receiver in Example 1 of this invention Line AA sectional view of FIG. The principal part perspective view of the upper surface of the heat receiving plate in Example 1 of this invention (A) Line BB sectional view of FIG. 3, (b) Line CC sectional view of FIG. (A) Line BB sectional view of a modified example in which the micro fins in the first embodiment of the present invention are pin-shaped, (b) Line C- in a modified example in which the micro fins in the first embodiment of the present invention are pin-shaped. C cross section (A) A partially cutaway perspective view of a heat receiver in Embodiment 2 of the present invention, (b) a sectional view taken along line DD of FIG. Line DD sectional drawing which showed the modification of the microfin of the heat receiver in Example 2 of this invention The front view which shows the manufacturing method of the radiation fin in Example 2 of this invention The whole block diagram which mounted the cooling device in Example 3 of this invention in notebook PC (A) Exploded perspective view of the heat receiver described in (Patent Document 1), (b) Partial sectional view of the heat receiver described in (Patent Document 1)

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heat receiver 2 Heat receiving plate 2a Eaves part 2b Heat receiving surface 2c Recessed part 3 Radiation fin 3a Micro fin 3b Upper side edge part 3c Lower side edge part 3d Liquid supply side edge part 3e Liquid discharge side edge part 3f Right side edge part 3g Left side edge part 4 Casing 5 Suction path 6 Discharge path 7 Impeller 7a Blade 7b Small hole 8 Magnet rotor 9 Stator 10 Coil 11 Circuit board 12 Pump chamber 13 Heating element 14 Refrigerant supply path 15 Circulating heat transfer chamber 16 Partition member 16a Cylindrical wall 16b Through hole 16c Suction communication port 17 Shaft 18 Seal member 19 Laminated structure 20 Brazing material 21 Crevice 22 Refrigerant discharge path 23 Resist 24 Case 25 Keyboard 26 Substrate 27 Radiator 28 Liquid circulation path K Impeller entrance

Claims (13)

A heat receiver that connects a pair of liquid circulation paths and allows liquid refrigerant to flow inside. A heat receiver that has a heat receiving surface that is thermally connected to a heating element on one surface and a plurality of radiation fins formed on the other surface. A plate and a casing which is combined so as to accommodate the heat radiating fin in the heat receiving plate, and the space with the heat receiving plate constitutes a part of the flow path of the liquid refrigerant, and the heat radiating fin contacts the liquid refrigerant A heat receiver characterized in that a plurality of micro fins are formed on a surface. The heat receiver according to claim 1, further comprising a refrigerant supply path that communicates with a suction path located on a suction side of the liquid circulation path and supplies a liquid refrigerant in an extending direction of the radiation fin. The heat receiver according to claim 1, wherein the microfin is formed in a flat plate shape and extends in a direction in which the liquid refrigerant flows. The heat receiver according to claim 1, wherein the micro fins have a pin shape and are arranged in a staggered manner in a direction in which the liquid refrigerant flows. 5. The heat receiver according to claim 3, wherein the total height of the micro fins is different from each other. The heat receiver according to claim 1, wherein the microfin is formed by etching. The heat receiver according to claim 1, wherein the radiating fins are joined to each other to form a laminated structure. The heat receiver according to claim 7, wherein the heat radiating fin is a laminated structure in which end portions positioned substantially parallel to a flow direction of the liquid refrigerant are joined to each other. The heat receiver according to claim 1, wherein the radiating fins are arranged substantially perpendicular to the heat receiving plate. The heat receiver according to claim 1, wherein the radiating fins are disposed substantially parallel to the heat receiving plate. The heat receiver according to claim 1, further comprising a centrifugal pump for circulating a liquid refrigerant in the heat receiver. A cooling device comprising the heat receiver according to claim 1. A heat receiving plate having a heat receiving surface thermally connected to the heating element on one surface and a plurality of heat radiating fins formed on the other surface, and the heat receiving plate combined with the heat receiving plate so as to accommodate the heat radiating fins. And a casing that forms a part of the flow path of the liquid refrigerant, and a method of manufacturing a heat receiver in which a plurality of micro fins are formed on a contact surface of the heat radiation fin with the liquid refrigerant, the heat radiation fin A first step of forming the micro fins on the surface of the substrate by etching, a second step of joining the radiating fins to each other to form a laminated structure, and a third step of joining the laminated structure to the heat receiving plate, A method of manufacturing a heat receiver, comprising:

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