JP2004044917A - Cooling device, electric appliance, and manufacturing method for cooling device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling device easily manufacturable in a small and thin construction, having a wide degree of freedom in the design of heat radiation, and excellent in the heat transporting ability. <P>SOLUTION: The cooling device 1 is structured so that grooves 6 of flow passage patterns constituting heat pipes are formed at one of the surfaces of each of an upper base board 2 and a lower base board 3, in which the surfaces where the passage patterns are formed facing each other, and that a wick 4 and a condenser 5 made of a material having a higher thermal conductivity are installed between the base boards and joined together. The upper and lower boards 2 and 3 are furnished with a wick outer frame hole 17 and a condenser outer frame hole 18 to admit fitting-in of the outer frames of the wick 4 and the condenser 5 for exposing their end faces at the board surfaces. Heat emitting devices 61 and 62 as objects to be cooled are contacted with the end face of the outer frame of the wick 4 exposed at the board surface, and thereby the heat of the heat emitting devices is conducted directly to the wick 4, and an efficient heat transport can be accomplished. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a cooling device that cools a heat-generating device and a method of manufacturing the same, and further relates to an electronic apparatus equipped with a heat-generating device such as a computer and a digital camera.
[0002]
[Prior art]
In recent years, high-speed LSIs (Large Scale Integration) such as CPUs (Central Processing Units) and video accelerators mounted on personal computers and the like, large-area flat panel displays and the like, as well as large areas such as personal computers, Large-capacity storage media that use flash memory as a storage element, such as digital cameras and digital audio devices, such as memory sticks, smart media, and compact flash (registered trademark), whose use is rapidly expanding in recent years. As a result, the amount of heat generated by the entire electronic device has been significantly increased.
[0003]
Therefore, the importance of a cooling device for cooling these heat generating devices is increasing. The cooling device generally includes a cooling fan, a Peltier device, a heat pipe, and the like. Here, the heat pipe will be particularly described.
[0004]
Normally, the heat pipe is formed of a metal tube having a capillary structure on the inner wall, and a working fluid such as water or CFC substitute is sealed in the sealed tube. Heat transfer is performed in this heat pipe as follows.
[0005]
When one end of the heat pipe is brought into contact with a device serving as a heat source, the heat causes the working fluid inside the tube to evaporate and evaporate. The vaporized working fluid moves at a high speed to the condensing section, where it is condensed and returns to a liquid, at which time heat is released. The working fluid that has returned to the liquid then returns to its original location through the capillary structure. In this way, heat transport is performed continuously and efficiently.
[0006]
[Problems to be solved by the invention]
However, since conventional heat pipes are tubular and are large-scale devices in space, they are not suitable for use in electronic devices such as personal computers and digital cameras that require small size and thinness, and are not suitable for use. is there.
[0007]
Therefore, a method has been proposed in which a heat pipe structure is formed in a substrate material such as a silicon substrate or a glass substrate.
[0008]
However, when a heat pipe is formed using a silicon substrate, heat from the object to be cooled diffuses on the surface of the silicon substrate because the heat conductivity of the silicon itself is good, and the internal working fluid is not sufficiently vaporized. However, there was a problem that the function as a function was not sufficiently exhibited.
[0009]
Further, when a glass substrate is used, there is a problem that the cooling target device cannot be cooled to a required temperature due to poor coupling efficiency in heat conduction with the cooling target device.
[0010]
In view of such circumstances, the present invention provides a cooling device and a method of manufacturing the same, which can be easily reduced in size and thickness, have a high degree of freedom in heat radiation design, and have excellent heat transport capability, and a circuit for preventing heat generated by an internal heat generating device. It is an object of the present invention to provide an electronic device capable of ensuring the stable operation of the electronic device with high reliability.
[0011]
[Means for Solving the Problems]
The cooling device according to the main aspect of the present invention, as means for solving the above problems, a two-layer substrate provided with a flow path of a working fluid constituting a heat pipe between layers, between the two-layer substrate Having an exposed portion sandwiched and exposed on at least one surface of the two-layered substrate, sucking and holding a liquid-phase working fluid by a capillary force in a working fluid flow path, and having a higher thermal conductivity than the substrate. A liquid suction holding member made of a material having a high
[0012]
In the cooling device according to the present invention, since the flow path of the working fluid constituting the heat pipe is formed between the two layers of the substrates, it is easy to reduce the size and thickness. Further, the heat pipe can be designed with a high degree of freedom by forming a flow path pattern on the substrate. In addition, since the liquid suction holding member made of a material having a higher thermal conductivity than the substrate is exposed on at least one surface of the substrate, the heat of the heat generating device to be cooled is directly transmitted to the liquid suction holding member, and the efficiency is improved. Heat transfer can be realized. Further, this makes it possible to use a material having a low thermal conductivity as a material for the substrate, thereby suppressing a decrease in heat transport efficiency due to heat diffusion in the substrate.
[0013]
In the cooling device of the present invention, the liquid suction holding member may have a form having a plurality of exposed portions exposed on both front and back surfaces of the two-layer substrate.
[0014]
As a result, it is possible to adopt a mode in which a heating device such as a CPU, a graphic chip, and a driver IC is mounted on each of the front and back surfaces of the two-layer board.
[0015]
Further, in the cooling device of the present invention, the cooling device further includes a latent heat emitting member that emits latent heat of the gas phase working fluid in the working fluid flow path, wherein the latent heat emitting member is sandwiched between the two layers of substrates, In addition, it may have an exposed portion that is exposed on at least one surface of the two-layer substrate.
[0016]
Thereby, the latent heat releasing member can be brought into contact with the heat radiating member outside the cooling device, the cooling capacity in the condensing portion of the heat pipe can be improved, and the heat transport efficiency of the cooling device can be further improved.
[0017]
Further, in the cooling device of the present invention, the liquid suction holding member includes a first channel portion for generating a capillary force corresponding to a flow path of a working fluid provided on one substrate, and an operation provided on the other substrate. And a second channel portion for generating a capillary force corresponding to the flow path of the fluid.
[0018]
By forming the channel portion for generating the capillary force on both surfaces of the liquid suction and holding member in this manner, it is possible to secure a wider contact area between the liquid suction and holding member and the working fluid in the liquid phase as a whole, and to improve the heat transport efficiency. Is further improved.
[0019]
Furthermore, in the cooling device of the present invention, the two-layer substrate is formed by joining substrates each having a pattern of a working fluid flow path formed on one surface, and each substrate has a different form. Alternatively, a flow path pattern of a working fluid may be formed.
[0020]
This further improves the degree of freedom in selecting the heat transport characteristics of the cooling device.
[0021]
Furthermore, in the cooling device of the present invention, the two-layered substrate is bonded to each other via the adhesive layer, and the thickness of the adhesive layer is set to be 1.5 nm or more and less than 1 μm, so that a material having high heat conductivity When is used for the adhesive layer, the decrease in efficiency of the cooling device caused by heat conduction in the adhesive layer can be reduced, and the adhesive strength required for bonding the substrates can be obtained.
[0022]
An electronic apparatus according to another aspect of the present invention includes a device that is a heat source and a cooling device that cools the device, wherein the cooling device is provided with a flow path of a working fluid forming a heat pipe between layers. A two-layered substrate, having an exposed portion sandwiched between the two-layered substrate and exposed on at least one surface of the two-layered substrate. A liquid suction and holding member made of a material having a higher thermal conductivity than the substrate for sucking and holding the working fluid, wherein the exposed portion of the liquid suction and holding member is in contact with the device;
[0023]
According to the present invention, since the liquid suction holding member made of a material having higher thermal conductivity than the substrate is exposed on at least one surface of the substrate, the heat of the device to be cooled is directly transmitted to the liquid suction holding member. By performing efficient heat transport in the cooling device, the device is efficiently cooled, and operation failure due to heat generation of the device can be prevented.
[0024]
Further, in the electronic apparatus of the present invention, the liquid suction holding member has a plurality of exposed portions that are exposed on both front and back surfaces of the two-layer substrate, and the devices that are heat sources are individually provided on these exposed portions. It may take the form of contact.
[0025]
This allows freedom of heat radiation design of electronic equipment, such as a form in which heat generating devices such as a CPU, a graphic chip, and a driver IC are mounted on each of the front and back surfaces of a two-layer substrate, and a heat sink can be attached to one surface. The degree improves.
[0026]
A method of manufacturing a cooling device according to another aspect of the present invention includes a step of forming an opening in at least one of the two substrates, and a method of forming a heat pipe on one surface of each of the two substrates. A step of forming a pattern of a flow path, and a liquid suction holding member having a protrusion adapted to an opening provided in the substrate and sucking and holding a liquid-phase working fluid by a capillary force in the working fluid flow path; Forming a latent heat releasing member for releasing the latent heat of the gas-phase working fluid in the working fluid flow path; and forming the liquid suction holding member and the latent heat release between the two flow path pattern forming surfaces of the substrates. And a step of joining by sandwiching the members.
[0027]
According to this manufacturing method, it is easy to reduce the size and thickness, and it is possible to easily manufacture a cooling device having a high degree of freedom in heat radiation design and excellent heat transport capability.
[0028]
Further, in the method of manufacturing a cooling device according to the present invention, in the production of the latent heat releasing member, a protrusion may be formed so as to fit the opening provided in the substrate.
[0029]
According to the present invention, by contacting the latent heat releasing member with the heat radiating member outside the cooling device, it is possible to manufacture a cooling device having a high cooling capacity in the condensing portion of the heat pipe and a high heat transport efficiency.
[0030]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0031]
FIG. 1 is an exploded perspective view of a cooling device according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of a state where the cooling device is assembled.
[0032]
As shown in these figures, the cooling device 1 includes an upper substrate 2 and a lower substrate 3 that constitute a two-layer substrate, a wick 4 that is a liquid suction holding member, and a condenser 5 that is a latent heat releasing member. Be composed.
[0033]
On one surface of each of the upper substrate 2 and the lower substrate 3, a groove 6 of a flow path pattern constituting a heat pipe is provided.
[0034]
The upper substrate 2 and the lower substrate 3 face each other with the flow path pattern forming surfaces therebetween, and the wick 4 and the capacitor 5 are arranged therebetween and joined to each other.
[0035]
FIG. 3 shows a plan layout of the flow path pattern, and FIG. 4 shows a plan layout of the flow path pattern in which the wick 4 and the condenser 5 are further arranged.
[0036]
By joining the upper and lower substrates 2 and 3, the groove 6 of the flow path pattern of each substrate 2 and 3 forms an evaporator 11, a vapor line 12, a condenser 13, and a liquid phase for evaporating a refrigerant as a working fluid. A line 14, a reservoir area 15, a refrigerant inlet 16, a gas-liquid phase separation groove 19, a wick outer frame opening 17, and a condenser outer frame opening 18 are formed.
[0037]
A refrigerant is sealed in the evaporator 11, the gas phase line 12, the condenser 13, the liquid phase line 14, and the reservoir area 15, thereby constituting a heat pipe.
[0038]
The evaporator 11 removes heat from the wick 4 having a capillary structure with the liquid-phase refrigerant filled therein, evaporates the liquid-phase refrigerant, and moves the gas-phase refrigerant to the gas-phase line 12. Part.
[0039]
The gas phase line 12 is a flow path for transmitting the gas phase refrigerant evaporated in the evaporator 11 to the condenser 13.
[0040]
The condenser 13 absorbs the latent heat of the vapor into the condenser 5 and condenses and liquefies the gas-phase refrigerant.
[0041]
The liquid phase line 14 is a flow path for moving the refrigerant liquefied in the condenser 13 to the evaporator 11.
[0042]
The reservoir area 15 is an area storing a liquid-phase refrigerant, and the refrigerant can be replenished from the reservoir area 15 to the evaporator 11 so that the amount of liquid in the evaporator 11 is kept constant.
[0043]
Further, each of the substrates 2 and 3 is provided with a refrigerant charging port 16, which is an inlet for injecting a refrigerant after the substrates are joined together, and a gas-phase line 12 and a liquid-phase line 14 are separated to suppress thermal interference therebetween. A wick outer frame opening 17 for fitting a gas-liquid phase separation groove 19 to be formed, and an outer frame portion of the wick 4 to be described later to expose the front and back end surfaces of the outer frame portion of the wick 4 on the substrate surface, and an outer frame of the capacitor 5. A capacitor outer frame opening 18 and the like are provided for fitting the parts and exposing the front and rear end surfaces of the outer frame part of the capacitor 5 on the surface of the substrate.
[0044]
As a material for the substrates 2 and 3, if the thermal conductivity is too high, heat diffusion on the substrate may adversely affect the heat transport efficiency of the heat pipe. For example, glass, polyimide, Teflon (registered trademark), PDMS For example, an organic plastic such as (polydimethylsiloxane) is used.
[0045]
Refrigerants such as water, ethanol, methanol, propanol (including isomers), ethyl ether, ethylene glycol, and florinate have a boiling point, thermal conductivity, and antimicrobial resistance that satisfy the design of the cooling and heat transport device. Fluids are used.
[0046]
The material of the wick 4 and the capacitor 5 has a high thermal conductivity, for example, a material having a thermal conductivity of 0.17 W / mK or more. Specifically, a material including at least one of Si, Cu, Al, Ni, Ti, Au, Ag, and Pt, a conductive polymer, a ceramic, and the like, have a thermal conductivity equivalent to that of a metal. Is used. More preferably, it is desirable to use a material having a thermal conductivity twice or more that of the substrate material.
[0047]
FIG. 5 shows the structure of the wick 4 in detail. In the figure, (a) is a side view, and (b) is a plan view.
[0048]
As shown in the figure, the wick 4 includes a channel portion 21 and outer frame portions 22 provided at both ends thereof. Microchannels 23 for generating a capillary force are provided on both upper and lower surfaces of the channel portion 21, respectively.
[0049]
As shown in FIG. 2, in a state where the wick 4 is combined with each of the substrates 2 and 3, the upper end surface 22 a and the lower end surface 22 b of the outer frame portion 22 of the wick 4 are front and back of the two-layer substrates 2 and 3, respectively. It is exposed on each surface 2a, 2b. That is, the upper end surface 22a and the lower end surface 22b of the outer frame portion 22 of the wick 4 have the same height as the front and back surfaces 2a and 2b of the two-layer substrates 2 and 3 or the two-layer substrates 2 and The respective heights are set so as to slightly protrude from the surfaces 2a and 2b of the front and back surfaces of No. 3 respectively. The upper end surface 22a and / or the lower end surface 22b of the outer frame portion 22 of the wick 4 exposed from the two layers of the substrates 2 and 3 are contacted or joined with, for example, a heating device to be cooled. Has become.
[0050]
Similarly, the capacitor 5 includes a channel portion 31 and an outer frame portion 32. The channel portion 31 of the capacitor 5 is provided with microchannels 33 functioning as fins on both upper and lower surfaces in order to enhance heat dissipation. An outer frame portion 32 is provided on the capacitor 5 similarly to the wick 4. The upper end surface 32 a and the lower end surface 32 b of the outer frame portion 32 are formed on the front and back surfaces 2 a of the two-layer boards 2 and 3. , 2b. In other words, the upper end surface 32a and the lower end surface 32b of the outer frame portion 32 of the capacitor 5 have the same height as the front and back surfaces 2a and 2b of the two-layer substrates 2 and 3 or the two-layer substrates 2 and The respective heights are set so as to slightly protrude from the surfaces 2a and 2b of the front and back surfaces of No. 3 respectively. A member having high heat dissipation or high heat conductivity outside the cooling device 1 is brought into contact with and joined to the upper end surface 32a and / or the lower end surface 32b of the outer frame portion 32 of the capacitor 5.
[0051]
As described above, the cooling device 1 of the present embodiment is configured such that the upper and lower substrates 2 and 3 having the flow path pattern grooves 6 for the heat pipes provided on one surface thereof are separated from the respective flow path pattern grooves 6. The wick 4 and the condenser 5 are arranged therebetween, and the wick 4 and the condenser 5 are arranged and bonded to each other. The inside of the cooling device 1 is in a predetermined reduced pressure state.
[0052]
The heat transport in the cooling device 1 is performed as follows.
[0053]
The liquid-phase refrigerant filled in the evaporator 11 absorbs the heat of the heat generating device that is in contact with the wick 4 outside the two-layer substrates 2 and 3 and evaporates with this heat. Then, the vapor (vapor-phase refrigerant) moves to the vapor-phase line 12 due to the vapor pressure difference. The gas-phase refrigerant moves to the condenser 13 through the gas-phase line 12, where the gas-phase refrigerant loses latent heat by the condenser 5 and returns to liquid. The liquefied refrigerant moves to the evaporator 11 through the liquid phase line 14. Heat transfer is performed by such a cycle.
[0054]
Next, a method of manufacturing the cooling device 1 will be described.
[0055]
First, as shown in FIG. 6, openings such as a refrigerant charging port 16, a wick outer frame port 17, and a condenser outer frame port 18 are formed in the upper and lower substrates 2 and 3, respectively.
[0056]
Subsequently, as shown in FIG. 7, grooves 6 of a flow path pattern constituting a heat pipe are formed on one surface of each of the substrates 2 and 3. Methods for forming these openings and grooves 6 include sandblasting, RIE (dry etching), wet etching, UV light etching, laser etching, proton light etching, electron beam drawing etching, micromolding, and the like.
[0057]
Next, in order to secure an area where the wick 4 fits in each of the substrates 2 and 3, as shown in FIG. 9 is removed at a uniform depth by etching or the like using a metal mask 42 having an opening 41 corresponding to the above, and as shown in FIG. 9, a wick fitting concave portion 43 having a flow path pattern on the removed surface is formed.
[0058]
Next, as shown in FIG. 1, the surfaces on which the flow path patterns of the substrates 2 and 3 are formed face each other, and the wick 4 and the capacitor 5 are connected to the outer frame portions 22 and 32 and the wick outer frame opening 17 and The substrates 2 and 3 are fitted into the capacitor frame 18 and sandwiched between the substrates 2 and 3 to join the substrates 2 and 3 together. Thereby, the cooling device 1 having the appearance as shown in FIG. 10 is completed.
[0059]
Methods for bonding the substrates 2 and 3 include, for example, anodic bonding, pressure / heat fusion, ultrasonic bonding, bonding by chemical bonding (for example, when the substrate material is polyimide), bonding of self-adhesive materials ( For example, when the substrate material is Si rubber).
[0060]
At this time, an adhesive layer (reference numeral 34 in FIG. 2 and FIG. 10) may be formed on the flow path pattern forming surface of one or both substrates and joined. In this case, for example, metal is implanted into the material of each substrate using ion implantation, a thin film such as copper is formed by a vapor deposition device, or the surface activity is increased by plasma irradiation before joining. Is preferred.
[0061]
Here, the thickness of the adhesive layer 34 is preferably smaller when a material having high thermal conductivity is used for the adhesive layer 34. This is because the heat conduction caused by the adhesive layer 34 is reduced, and the efficiency of the cooling device 1 is prevented from lowering. On the other hand, if the thickness of the adhesive layer 34 is too small, a sufficient function as the adhesive layer cannot be expected.
[0062]
For example, the thickness of the adhesive layer 34 is at least 1.5 nm or more and less than 1 μm, preferably 3 nm or more and less than 1 μm, and more preferably 10 nm or more and less than 200 nm.
[0063]
Subsequently, a method of manufacturing the wick 4 and the capacitor 5 will be described with reference to FIG.
[0064]
A plate 51 made of the above-mentioned material, which satisfies the width, length, and height of the wick 4 and the capacitor 5, is prepared (a). An outer frame portion 52 and a channel portion 53 on one of the upper and lower sides are formed from the plate material 51 by, for example, machining (b). Next, a microchannel 54 having a shape and size suitable for the wick 4 and the capacitor 5 is formed on one surface of the channel portion 53 by, for example, machining (c). Then, on the other side of the plate member 51, similarly, the outer frame portion 52, the channel portion 53, and the microchannel 54 are formed by machining or the like.
[0065]
Other methods for manufacturing the wick 4 and the capacitor 5 include RIE (dry etching), wet etching, UV-LIGA, and electroforming.
[0066]
In the cooling device 1 configured as described above, since the outer frame portion 22 of the wick 4 is exposed on the front and back surfaces 2a and 3a of the two-layer substrates 2 and 3, as shown in FIG. It can be incorporated in various forms in the device.
[0067]
For example, as shown in FIG. 12, a wick 4 in which heat generating devices 61 and 62 such as a CPU, a graphic chip, and a driver IC in an electronic device 60 are exposed on front and back surfaces 2 a and 3 a of the cooling device 1. Can be taken in contact with the outer frame 22.
[0068]
As shown in FIG. 13, by mounting the heat sink 63 on one of the front and back surfaces of the cooling device 1 so as to be in contact with the outer frame 22 of the wick 4, the upper limit of the heat transport amount of the cooling device 1 is obtained. And the degree of freedom of the heat radiation design of the electronic device 60 is improved.
[0069]
Further, as shown in FIG. 14, a plurality of cooling devices 1 are vertically and horizontally combined to form an array, and a flat panel display 71 such as an LCD (Liquid Crystal Display), a FED (Field Emission Display), a PDP (Plasma Display Panel), and a back surface. A form interposed between the chassis 73 can be adopted.
[0070]
Further, as shown in FIGS. 12 and 13, the outer frame portion 32 of the capacitor 5 is exposed on each of the front and back surfaces 2a and 3a of the two-layer boards 2 and 3, so that the exposed portion of the capacitor 5 is formed. The cooling capability of the condenser 13 can be increased by contacting a member 64 having high heat dissipation or heat conductivity outside the cooling device 1, for example, the chassis 64 of the electronic device 60.
[0071]
Therefore, the cooling device 1 according to the present embodiment can be incorporated with a high degree of freedom into various electronic device devices 60, such as a personal computer and a digital camera, on which a heating device is mounted, so that the heating device in the electronic device device 60 can be efficiently used. Can be cooled.
[0072]
Next, another embodiment of the cooling device 1 according to the present invention will be described.
[0073]
In the above-described embodiment, as shown in FIGS. 8 and 9, the wick fitting region 40 on the flow path pattern forming surface of each of the substrates 2 and 3 is etched to secure a region where the wick 4 fits in each substrate. The wick-fitting concave portion 43 in which the flow path pattern exists was formed on the removed surface with a uniform depth. According to this method, the thickness of the channel portion 21 of the wick 4 can be increased, the processing of the wick 4 can be facilitated, and the amount of heat absorbed by the wick 4 can be increased.
[0074]
However, the present invention is not limited to this, and the formation of the wick fitting recess is omitted, and as shown in FIG. 15, the channel portion 21A of the wick 4 is set within the range of the height H of the flow path 6A. Any configuration may be adopted.
[0075]
Further, in the above-described embodiment, as shown in FIG. 2, the heights of the upper and lower end surfaces 22a, 22b, 32a, 32b of the outer frame portions 22, 32 of both the wick 4 and the capacitor 5 are changed to the two-layer substrate 2 , 3 are set to be equal to or higher than the height of each of the front and back surfaces 2a, 2b. However, as shown in FIG. 16, both the wick 4 and the capacitor 5 have one of the upper and lower sides of the outer frame portions 22, 32. Only the height of the end faces 22a and 32a may be set to be equal to or higher than the height of the face 2a of the substrates 2 and 3.
[0076]
Further, in the above-described embodiment, a common flow path pattern is formed on each of the upper and lower substrates 2 and 3 and these flow path pattern forming surfaces are joined to face each other. However, as shown in FIG. By arranging the patterns of the flow path portions such as the line 12 and the liquid phase line 14 which can change the heat transport characteristics so as not to be vertically overlapped, the degree of freedom in selecting the heat transport characteristics is improved, and high efficiency is achieved. Can be achieved.
[0077]
Here, the upper substrate 2 is provided with a groove for forming the vapor line 12a, and the lower substrate 3 is provided with a groove for forming the vapor line 12b. The vapor lines 12a and 12b are positioned so as not to overlap. Is set. Similarly, the upper substrate 2 is provided with a groove forming the liquid phase line 14a, and the lower substrate 3 is provided with a groove forming the liquid phase line 14b. The liquid phase lines 14a and 14b are positioned so as not to overlap. Is set.
[0078]
【The invention's effect】
As described above, according to the present invention, a small and thin cooling device can be provided, and a heat pipe can be designed with a high degree of freedom by forming a flow path pattern on a substrate. In addition, since the liquid suction holding member made of a material having a higher thermal conductivity than the substrate is exposed on at least one surface of the substrate, the heat of the heat generating device to be cooled is directly transmitted to the liquid suction holding member, and the efficiency is improved. Heat transfer can be realized. Further, this makes it possible to use a material having a low thermal conductivity as a material for the substrate, thereby suppressing a decrease in heat transport efficiency due to heat diffusion in the substrate.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of a cooling device according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view of the cooling device of FIG.
FIG. 3 is a diagram showing a planar layout of a flow path pattern of the cooling device.
FIG. 4 is a diagram showing a planar layout of a flow path pattern, a wick and a capacitor in FIG. 3;
FIG. 5 is a side view and a plan view showing details of a wick structure.
FIG. 6 is a perspective view showing a process of forming openings such as a refrigerant charging port, a wick outer frame port, and a capacitor outer frame port on a substrate.
FIG. 7 is a perspective view showing a step of forming a groove of a flow path pattern constituting a heat pipe on a substrate.
FIG. 8 is a perspective view showing an etching step of a wick fitting region of the substrate.
FIG. 9 is a perspective view showing a state after etching a wick fitting region of the substrate.
FIG. 10 is a perspective view showing an appearance of a completed cooling device.
FIG. 11 is a diagram illustrating a method of manufacturing a wick and a capacitor.
FIG. 12 is a side view showing an example of a form in which the cooling device is incorporated into an electronic device.
FIG. 13 is a side view showing an example of another mode of incorporating the cooling device into the electronic apparatus.
FIG. 14 is a perspective view showing an embodiment in which a number of cooling devices are arrayed and used for cooling a flat panel display.
FIG. 15 is a sectional view showing another embodiment of the cooling device.
FIG. 16 is a sectional view showing a modified example of the wick and the condenser in the cooling device.
FIG. 17 is a plan view showing a cooling device when different flow path patterns are formed on upper and lower substrates.
[Explanation of symbols]
1 Cooling device
2 Upper substrate
3 Lower board
4 Wick
5 Capacitor
6 Channel pattern grooves
11 Evaporator
12 Gas phase line
13 Condenser
14 Liquid phase line
15 reservoir area
17 Wick outer frame entrance
18 Capacitor outer frame
21, 31 channel section
22, 32 Outer frame
23,33 micro channel
34 adhesive layer
60 Electronic equipment
61,62 Heating device

Claims (11)

A two-layer substrate in which the flow path of the working fluid constituting the heat pipe is provided between the layers,
An exposed portion sandwiched between the two-layered substrate and exposed on at least one surface of the two-layered substrate, sucks a liquid-phase working fluid by a capillary force in the working fluid flow path. And a liquid suction holding member made of a material having a higher thermal conductivity than the substrate. The cooling device according to claim 1, wherein the liquid suction holding member has a plurality of exposed portions that are exposed on both front and back surfaces of the two-layer substrate. A latent heat release member that releases latent heat of the gaseous working fluid in the flow path of the working fluid, wherein the latent heat release member is sandwiched between the two layers of the substrate; The cooling device according to claim 1, further comprising an exposed portion that is exposed on at least one surface. A first channel portion for generating a capillary force corresponding to a flow path of the working fluid provided on one of the substrates, and a flow path of the working fluid provided on the other substrate; The cooling device according to claim 1, further comprising a second channel portion for generating a capillary force corresponding to the above. The two-layered substrate is formed by joining substrates each having the flow pattern of the working fluid formed on one surface, and the pattern of the flow path of the working fluid provided on each of the substrates is The cooling device according to claim 1, wherein the cooling devices are different from each other. The cooling device according to claim 1, wherein the two substrates are bonded to each other via an adhesive layer, and the thickness of the adhesive layer is in a range of 1.5 nm or more and less than 1 μm. A device that is a source of heat,
A cooling device for cooling the device,
The cooling device is sandwiched between a two-layer substrate in which a flow path of a working fluid constituting a heat pipe is provided between layers, and a surface is provided on at least one surface of the two-layer substrate. A liquid suction holding member made of a material having a higher thermal conductivity than the substrate, having an exposed portion that emerges and sucking and holding a liquid-phase working fluid by capillary force in the flow path of the working fluid. An electronic apparatus, wherein the exposed portion of the liquid suction and holding member is in contact with the device. The liquid suction holding member has a plurality of exposed portions that are exposed on both front and back surfaces of the two-layer substrate, and a device that is a heat source is individually contacted with these exposed portions. The electronic device according to claim 7. The cooling device further includes a latent heat emitting member that emits latent heat of a gas-phase working fluid in the flow path of the working fluid, the latent heat emitting member being sandwiched between the two-layered substrates, and 8. The electronic device according to claim 7, further comprising an exposed portion exposed on at least one surface of the two-layer substrate, wherein the exposed portion is brought into contact with a heat radiation member outside the cooling device. Equipment and devices. Forming an opening in at least one of the two substrates;
Forming a pattern of a working fluid flow path constituting a heat pipe on one surface of each of the two substrates;
A step of producing a liquid suction holding member that has a protrusion that fits the opening provided in the substrate and that sucks and holds a liquid-phase working fluid by capillary force in the working fluid flow path;
A step of producing a latent heat releasing member that releases latent heat of a gas-phase working fluid in the working fluid flow path,
Joining the surfaces of the two substrates on which the flow path patterns are formed with the liquid suction holding member and the latent heat releasing member interposed therebetween. The method of manufacturing a cooling device according to claim 10, wherein in producing the latent heat releasing member, a protruding portion that fits into the opening provided in the substrate is formed.

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