JP2004044990A - Cooling device, and method of manufacturing electronic device and cooling device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling device and a method of manufacturing an electronic device and the cooling device, capable of increasing the transporting amount of hydraulic fluid by improving the lyophilic characteristic of a channel surface with the hydraulic fluid, to increase the amount of vaporization heat in the device and to improve the heat efficiency. <P>SOLUTION: In this cooling device 1, a hydrophilic film 18 made of hydrosilsesquioxane and the like is formed on a groove surface of a liquid-phase passage 12 of a first base 10 provided with a groove of the channel on its surface to circulate the hydraulic fluid, whereby the lyophilic characteristic of the groove surface with the hydraulic fluid is improved, the transporting amount of the hydraulic fluid can be increased, the amount of vaporization heat in the device can be increased, and the heat efficiency can be improved. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a cooling device, an electronic device, and a method for manufacturing a cooling device.
[0002]
[Prior art]
Storage media such as Memory Stick (registered trademark), Smart Media (registered trademark), and Compact Flash (registered trademark) are smaller and thinner than conventional ones such as floppy disks, and have a very large storage capacity. It has been widely used in electronic devices such as personal computers and digital cameras.
[0003]
These storage media include those having a flash memory and a driver integrally, and those having the driver mounted on the apparatus main body or another card. However, in any case, the storage capacity has been considerably increased recently.
[0004]
[Problems to be solved by the invention]
By the way, when the storage capacity of the storage medium is increased as described above, a great deal of heat is generated from the driver, which causes problems such as malfunction.
[0005]
Therefore, for example, it is conceivable to provide a cooling device on the electronic device side, and as such a cooling method, there is a technique using a heat pipe.
[0006]
The heat pipe is a metal pipe having a capillary structure on the inner wall of the pipe, and has a vacuum inside, in which a small amount of water or CFC substitute is sealed. When one end of the heat pipe is brought into contact with a heat source and heated, the liquid inside evaporates and evaporates. At this time, heat is taken in as latent heat (heat of vaporization). Then, it moves at high speed (almost at the speed of sound) to a low-temperature portion, where it is cooled and returns to a liquid, and releases heat (heat release by condensation latent heat). Since the liquid returns to the original position through the capillary structure (or by gravity), heat can be continuously and efficiently transferred.
[0007]
However, since the conventional heat pipe is a tubular and large-sized device, it is not suitable for a cooling device of an electronic device such as a personal computer or a digital camera, which needs to be reduced in size and thickness.
[0008]
Therefore, in order to reduce the size of the heat pipe, a groove is formed on the joint surface between two glass substrates such as Pyrex (registered trademark), and the flow path constituting the heat pipe is formed by joining these substrates. A cooling device formed in between has been proposed. At the time of the above-mentioned joining, a small amount of water or a substitute for chlorofluorocarbon is sealed, and these cause a state change in the heat pipe, thereby serving as a heat pipe.
However, glass such as Pyrex (registered trademark) described above does not have sufficient lyophilicity, and when used as a flow path substrate of a heat pipe, there is a problem that the amount of infused liquid is small, thereby lowering the heat transport efficiency. .
[0009]
Then, a method of forming a film on the surface of the flow path substrate is considered. However, sputtering, which is a mainstream method of forming a film, has a disadvantage that a film cannot be formed properly in a flow path having a deep groove.
[0010]
Therefore, the present invention has been made in view of the above circumstances, and an object of the present invention is to provide a cooling device, an electronic device, and a method of manufacturing a cooling device that can increase the amount of heat of vaporization in a device and improve thermal efficiency. I do.
[0011]
[Means for Solving the Problems]
A cooling device according to a first aspect of the present invention includes a cooling unit that cools an object by vaporizing a working fluid by heat from the object, and a cooling unit that liquefies the working fluid vaporized in the cooling unit and performs the cooling. A liquefied part circulating in the part, a liquefied working fluid flowing from the liquefied part to the cooling part, a first flow path having a hydrophilic film formed on the surface, and the liquefied part from the cooling part to the liquefied part. A second flow path through which the vaporized hydraulic fluid flows.
[0012]
In the present invention, since the hydrophilic film is formed on the surface of the first flow path through which the liquefied working fluid flows from the liquefaction unit to the cooling unit, it is possible to increase the infusion amount of the working fluid. The amount of heat of vaporization in the device can be increased and the thermal efficiency can be improved.
[0013]
According to one embodiment of the present invention, a wick groove constituting the cooling unit has a first substrate provided on a first surface, and a second surface joined to the first surface, A second substrate having, on the second surface, grooves forming the first channel and the second channel provided on the surface. By joining the two substrates, a reduction in size and thickness can be achieved.
[0014]
According to one embodiment of the present invention, the film on the surface of the groove is formed by a coating process. This makes it possible to reliably form a film on the groove surface.
[0015]
According to one embodiment of the present invention, the coating film is made of a material having a Si-OH group. This forms a lyophilic film such as a Si-OH group, so that the amount of infusion can be increased.
[0016]
According to one embodiment of the present invention, the hydrophilic film is made of hydrosilsesquioxane or alkali glass. Thereby, hydrophilicity can be increased and the amount of infusion can be increased.
[0017]
According to one embodiment of the present invention, a contact angle between the flow path surface and the working fluid is 0 to 30 degrees. Thus, since the capillary force is proportional to cos θ (θ: contact angle), a larger capillary force can be obtained by reducing the contact angle.
[0018]
An electronic device according to a second aspect of the present invention includes a cooling unit that cools an object by vaporizing a working fluid by heat from the object, and a cooling unit that liquefies the working fluid vaporized by the cooling unit and performs the cooling. A liquefied part circulating in the part, a liquefied working fluid flowing from the liquefied part to the cooling part, a first flow path having a hydrophilic film formed on the surface, and the liquefied part from the cooling part to the liquefied part. A cooling device having a second flow path through which the vaporized working fluid flows is mounted.
[0019]
According to the present invention, since the cooling device having the above-described configuration and having good cooling performance is mounted, the electronic device itself does not malfunction due to heat.
[0020]
A method of manufacturing a cooling device according to a third aspect of the present invention includes a step of forming a first substrate provided with a wick groove forming a cooling unit on a first surface, a first flow path and a second flow path. Forming a second substrate provided with a groove constituting a flow path of the second substrate on the second surface, forming a hydrophilic film on the surface of the second substrate, Bonding the first surface and the second surface of the second substrate so as to be in contact with each other. According to the present invention, the cooling device having the above configuration can be efficiently and reliably manufactured.
[0021]
According to one embodiment of the present invention, the step of forming the hydrophilic film on the first substrate is performed by a coating process. Thereby, it is possible to appropriately form a film even in a deep groove.
[0022]
According to one embodiment of the present invention, the method further comprises a step of removing a portion other than the groove of the first flow path after applying the hydrophilic film. Thereby, a hydrophilic film can be appropriately formed only in the first flow path in which the working fluid circulates.
[0023]
According to one embodiment of the present invention, the step of removing the hydrophilic film is performed by dry etching, ashing, or oxygen plasma. Thereby, the film at the unnecessary portion can be surely removed.
[0024]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0025]
(1st Embodiment)
(Cooling system)
FIG. 1 is an exploded perspective view of the cooling device of the present invention, and FIG. 2 is a sectional view of the cooling device in an assembled state.
[0026]
As shown in FIGS. 1 and 2, the cooling device 1 includes four substrates. The lower substrate 10 is a rectangular substrate made of Pyrex (registered trademark) glass, and is disposed on the lower side. The capacitor substrate 20 and the wick substrate 40 are rectangular substrates made of silicon. The upper substrate 30 is a rectangular substrate made of Pyrex (registered trademark) glass, and is disposed on the upper side. The grooves of the capacitor substrate 20 and the wick substrate 40 are incorporated into holes 32 and 34 of the upper substrate 30, respectively. These four substrates 10, 20, 30, 40 are bonded and fixed via an adhesive layer 50. Grooves 11, 21, 31, and 41 are formed on the surface 10a of the lower substrate 10, the surface 20b of the capacitor substrate 20, the surface 30b of the upper substrate 30, and the surface 40b of the wick substrate. These grooves are formed so as to function as a loop-shaped heat pipe when the four substrates are bonded.
[0027]
Hereinafter, the configuration of the grooves formed in each of the substrates 10, 20, 30, and 40 will be described with reference to FIGS.
[0028]
As shown in FIG. 3, a groove 11 is formed on the surface 10a of the lower substrate 10. The groove 11 includes, as main parts, a liquid phase passage 12 through which a working fluid in a liquid phase flows, a gas phase passage 15 through which a working fluid in a gas phase flows, a reservoir 13 for supplying the working fluid, and a storage unit 17. It is composed of The liquid phase path 12 is formed by being covered with a hydrophilic film 18 made of, for example, hydrosilsesquioxane.
[0029]
As shown in FIG. 4, the capacitor substrate 20 and the wick substrate 40 are incorporated into the upper substrate 30 to form the upper composite substrate 100. Here, as shown in FIG. 4, the capacitor substrate 20 and the wick substrate 40 are incorporated into the upper substrate 30 to form the upper composite substrate 100.
[0030]
A groove 21 is formed on the surface 20b of the capacitor substrate 20. The groove 21 functions as a condenser 22 for condensing the gas-phase working liquid introduced from the gas phase passage 15 into a liquid phase.
[0031]
A groove 41 is formed on the surface 40b of the wick substrate 40. The groove 41 functions as a cooling unit, and vaporizes (gas-phases) the liquid-phase working fluid introduced from the liquid phase path 12 or the reservoir 13.
[0032]
FIG. 5 shows a state where the lower substrate 10 and the upper composite substrate 100 are joined.
[0033]
A working fluid (not shown) is sealed inside a heat pipe formed by joining the lower substrate 10 and the upper composite substrate 100. The enclosed working fluid circulates in the heat pipe while changing its state from a liquid phase to a gas phase or from a gas phase to a liquid phase. Thereby, heat transfer is performed, and the cooling device 1 functions.
[0034]
Hereinafter, the state of circulation of the liquid phase / gas phase will be described with the flow path 12 as a starting point for convenience.
[0035]
First, the working fluid flows into the wick 42 from the flow channel 12. At this time, when the amount of liquid flowing into the wick 42 is equal to or less than a predetermined value, a shortage of liquid is supplied from the reservoir 13 in order to avoid dryout.
[0036]
The liquid flowing into the wick 42 is heated and boiled. The working fluid that has been vaporized by boiling to a gas phase flows into the gas receiving portion 14. This gas flows into the condenser 22 via the flow path 15 and is condensed into a liquid (liquid phase). The working fluid condensed at this time flows into the low temperature section 16 arranged below the condenser 22. Then, the working fluid is circulated again from the low temperature section 16 to the flow path 12. When the amount of liquid flowing from the low temperature section 16 into the flow channel 12 is equal to or less than a predetermined value, the liquid stored in the liquid storage section 17 flows into the low temperature section 16.
[0037]
In this embodiment, glass is used as the material of the substrate. However, other materials such as plastic may be used, or a combination of a glass substrate and a plastic substrate may be used. Further, in the present invention, any material having a lower thermal conductivity than silicon can be used as a material for the substrate.
[0038]
Further, although the material of the capacitor substrate 20 and the wick substrate 40 is made of silicon, another material, for example, a metal such as copper or nickel may be used.
[0039]
Further, as a hydrophilic film material, alkali glass can be used instead of hydrosilsesquioxane. FIG. 6 is a sectional view of a cooling device using alkali glass as a hydrophilic film material. As shown in FIG. 6, as the hydrophilic film 18 formed on the substrate 10 and the substrate 30, alkali glass is used instead of hydrosilsesquioxane.
[0040]
In this case, since the alkali glass itself also functions as an adhesive, this alkali glass is applied as an adhesive not only to the grooves such as the liquid phase path 12 and the like but also to the joint surface between the substrate 10 and the substrate 30. It has become. Thereby, the adhesive layer 50 becomes unnecessary.
[0041]
FIG. 7 schematically shows the state of the liquid flowing through the flow channel. FIG. 7A is a diagram schematically illustrating a state of a liquid flowing through a groove formed of Pyrex (registered trademark) glass, and FIG. FIG. 4 is a diagram schematically illustrating a state of a liquid flowing through a groove in which a film is formed.
[0042]
As shown in FIG. 7A, the liquid flowing through the groove formed of Pyrex (registered trademark) glass has a contact angle with the groove on the glass surface formed at the time of flowing through the groove of more than 30 degrees. At such a contact angle, there is a problem that the transport amount of the working fluid is not sufficient because the hydrophilicity is not sufficient. When the heat transport amount when the film 18 was not formed was measured, it was 5 W.
[0043]
On the other hand, as shown in FIG. 7B, the liquid flowing through the groove formed by coating the glass surface with the hydrophilic film is covered with the hydrophilic film 18 formed when flowing through the groove. The contact angle with the formed groove is 0 to 30 degrees. At such a contact angle, it has hydrophilicity and the capillary force also increases. This makes it possible to increase the transport amount of the working fluid. When the heat transport amount when the film 18 was formed in this way was measured, it was 8 W. That is, it was confirmed that the heat transport amount was improved by about 60% by forming the film 18 as compared with the case where the conventional film 18 was not formed.
[0044]
As described above, the cooling device 1 of the present invention has a structure in which the groove of the flow path for circulating the working fluid is formed on the surface of the liquid phase passage 12 of the first substrate 10. The film 18 is formed, and the lyophilicity between the groove surface and the working fluid is improved, thereby enabling an increase in the amount of working fluid infused, thereby increasing the amount of vaporized heat in the device and improving the thermal efficiency. And
[0045]
(Method 1 for manufacturing cooling device)
First, a method for manufacturing a cooling device when hydrosilsesquioxane is used as a film material will be described.
[0046]
FIG. 8 shows a manufacturing process of the cooling device 1.
[0047]
First, a groove of the substrate 10 made of Pyrex (registered trademark) glass and a hole of the substrate 30 functioning as a heat pipe are formed (Step 801). These grooves and holes are formed by sand blasting, RIE (dry etching), wet etching, UV light etching, laser etching, proton light etching, electron beam drawing etching, micromolding, or the like.
[0048]
Next, grooves of the capacitor substrate 20 and the evaporator substrate 40 made of silicon functioning as a capacitor or a wick are formed (Step 802). At this time, a groove is formed by machining. Other manufacturing methods include dry etching (for example, RIE (reactive ion etching)), wet etching, UV-LIGA, and electroforming.
[0049]
Next, a film forming process of the hydrophilic film 18 is performed on the surface of the liquid phase path 12 of the substrate 10 (Step 803).
[0050]
First, the step of forming the hydrophilic film 18 on the substrate 10 will be described with reference to FIG.
[0051]
FIG. 9 is a view showing a step of performing a surface treatment on the liquid phase path 12 of the substrate 10.
[0052]
FIG. 9A shows the substrate 10 on which a groove has been formed in step 701.
[0053]
In FIG. 9B, a hydrophilic film 18 made of hydrosilsesquioxane is applied to the entire substrate so as to have a thickness of about 0.1 to 20 μm. At this time, since the film 18 is formed by coating instead of vapor deposition such as CVD (Chemical Vapor Deposition), it is possible to surely form a film even in a deep groove.
[0054]
In FIG. 9C, a necessary portion of the film 18, in this case, at least the liquid phase path 12 is masked by a photolithographic mask method.
[0055]
In FIG. 9D, the unnecessary portion of the film 18 that is not masked is removed by dry etching. Thus, the film 18 formed on the surface of the substrate 10 is formed only on the liquid phase path 12 at least. Further, the film 18 may be formed in the groove of the vapor phase path 15. Here, ashing or oxygen plasma may be used as a removing method.
[0056]
In FIG. 9E, a film 18 in the liquid phase path 12 is formed.
[0057]
Further, the film 18 may be formed on the holes of the substrate 30 in the same manner.
[0058]
FIG. 10 is a view showing a step of performing a surface treatment on the holes of the substrate 30.
[0059]
In FIG. 10A, in step 701, an a-Si bonding layer 50 is formed on the surface of the substrate 30 in which the holes are formed so as to have a thickness of about 5 nm to 1000 nm on a surface to be bonded to the substrate 10.
[0060]
In FIG. 10B, a hydrophilic film 18 made of hydrosilsesquioxane is applied to the entire substrate so as to have a thickness of about 0.1 to 20 μm. At this time, the film 18 is formed not by vapor deposition such as CVD (Chemical Vapor Deposition) but by coating, so that the film can be surely formed even in the hole.
[0061]
In FIG. 10C, by flattening the surface by using an etch-back method, for example, the film 18 is not exposed on the surface of the substrate 30 that is bonded to the substrate 10, but only inside the hole. Is formed. Thereby, in the cooling device 1 formed through the later-described steps, the hydrophilicity of the inside of the hole of the substrate 30 is also improved, so that the infusion amount of the working fluid can be increased.
[0062]
Next, the substrate 10 having the groove and the hole formed therein is joined to the substrate 30 by using an anodic bonding method (step 804). At this time, the substrate 10 and the substrate 30 are heated to 300 to 400 degrees, and a voltage of 500 v to 1 kv is applied. As a result, an electrostatic attractive force is generated between the Pyrex (registered trademark) glass of the substrate 10 and the substrate 30 and the a-Si adhesive layer 50 formed on the surface of the substrate 30 to be joined to the substrate 10, and chemical Joined by joining. At the time of this joining, a substance that changes state in the heat pipe, for example, water is sealed in the groove as a working fluid.
[0063]
In addition, although the description has been made of the anodic bonding, various bonding methods such as pressure / heat fusion and ultrasonic bonding may be used.
[0064]
Further, a step of incorporating the capacitor substrate 20 and the evaporator substrate 40 into the hole formed through the substrate 30 is performed (Step 805). Thereby, the cooling device 1 is formed.
[0065]
(Cooling device manufacturing method 2)
Next, a description will be given of a manufacturing method in which an alkali glass is used for the hydrophilic film 18 instead of hydrosilsesquioxane. Here, the same detailed parts as described above will be omitted.
[0066]
FIG. 11 shows a manufacturing process of the cooling device.
[0067]
First, a groove of the substrate 10 and a hole of the substrate 30 made of Pyrex (registered trademark) glass functioning as a heat pipe are formed (Step 1101).
[0068]
Next, grooves of the capacitor substrate 20 and the evaporator substrate 40 made of silicon functioning as a capacitor or a wick are formed (step 1102).
[0069]
Next, a film forming process of the hydrophilic film 18 is performed on the joint surface between the substrate 10 and the substrate 30 (Step 1103).
[0070]
First, a step of forming the hydrophilic film 18 on the substrate 10 will be described with reference to FIG.
[0071]
FIG. 12 is a view showing a step of performing a film treatment on the bonding surface of the substrate 10.
[0072]
FIG. 12A shows the substrate 10 on which the groove is formed in Step 1101.
[0073]
In FIG. 12B, a hydrophilic film 18 made of alkali glass is applied to the entire substrate so as to have a thickness of about 0.1 to 20 μm.
[0074]
FIG. 13 is a view showing a step of performing a surface treatment on the holes of the substrate 30.
[0075]
In FIG. 13A, the substrate 30 has holes formed in step 1101.
[0076]
In FIG. 13B, a hydrophilic film 18 made of alkali glass is applied to the substrate 30 so as to have a thickness of about 0.1 to 20 μm. As described above, since the hydrophilic film 18 of alkali glass applied to the bonding surface between the substrate 10 and the substrate 30 also functions as an adhesive, the hydrophilic film 18 differs from the hydrosilsesquioxane manufacturing method described above. It is not necessary to remove the film 18.
[0077]
Next, the substrate 10 having the groove and the hole formed therein is joined to the substrate 30 by using an anodic bonding method (step 1104). At the time of this joining, for example, water is sealed in the groove as a working liquid.
[0078]
Further, a step of incorporating the capacitor substrate 20 and the evaporator substrate 40 into the hole formed through the substrate 30 is performed (step 1105). Thereby, the cooling device 1 is formed.
[0079]
The cooling device can be efficiently manufactured by each of the manufacturing methods described above.
[0080]
(Electronic equipment)
FIG. 14 is a schematic perspective view of a personal computer equipped with the cooling device according to the present invention.
[0081]
The personal computer 150 has a slot 151 for attaching and detaching a recording medium 154 having a flash memory 153 and a driver 152, and a processing unit 155. The cooling device 1 according to the present invention is arranged in the personal computer 150 such that the wick groove 41 is located immediately below the driver 152, for example, of the recording medium 154 mounted via the slot 151.
[0082]
Further, the cooling device 1 according to the present invention may be arranged such that the evaporator is adjacent to the processing unit 155. In this case, it is preferable to install the condenser so as to be adjacent to, for example, a cooling fan (not shown). Thus, the heat generated from the processing unit 155 is absorbed by the evaporator and released from the condenser by the function of the cooling fan, so that the processing unit 155 can be cooled.
[0083]
Here, the personal computer has been described as an example of the electronic device, but the cooling device according to the present invention can be mounted on another electronic device such as a digital camera or a video camera.
[0084]
(Display device)
FIG. 15 is a schematic perspective view of a liquid crystal display on which the cooling device according to the present invention is mounted.
[0085]
The liquid crystal display 160 has a driver 161, a display unit 162, and a cooling fan 163. The cooling device 1 according to the present invention is disposed in the liquid crystal display such that the evaporator is located adjacent to the driver 161 and the condenser is located adjacent to the cooling fan 163. The heat generated from the driver 161 by the activation of the liquid crystal display 160 is absorbed by the evaporator, and the absorbed heat vaporizes the liquid inside the cooling device 1 and flows to the condenser through the flow path. The cooling fan 163 cools the condenser, releases heat of the gas flowing into the condenser, and liquefies the gas again. The liquid liquefied by the condenser flows through the flow path to the evaporator, absorbs the heat generated from the driver 161 and vaporizes again. Thus, the driver 161 can be cooled by the circulation of the liquid inside the cooling device 1. Similarly, the display unit 162 can be cooled by installing an evaporator adjacent to the display unit 162.
[0086]
Here, a liquid crystal display is described as an example of the display device, but the cooling device according to the present invention can be mounted on other display devices such as a plasma display and an organic EL display.
[0087]
【The invention's effect】
As described above, according to the present invention, a cooling device, an electronic device, and a cooling device that enable an increase in the amount of hydraulic fluid to be infused, thereby enabling an increase in the amount of vaporized heat in a device and an improvement in thermal efficiency. A manufacturing method can be provided.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view illustrating a configuration of a cooling device according to an embodiment of the present invention.
FIG. 2 is a sectional view of an assembled state of the cooling device according to one embodiment of the present invention.
FIG. 3 is a plan view showing a substrate of the cooling device according to one embodiment of the present invention.
FIG. 4 is a plan view showing a substrate of the cooling device according to one embodiment of the present invention.
FIG. 5 is a plan view showing a state where two substrates, a capacitor substrate and an evaporator substrate of the cooling device according to one embodiment of the present invention are assembled.
FIG. 6 is a sectional view of a cooling device according to another embodiment of the present invention in an assembled state.
FIG. 7 is a diagram comparing a glass substrate having a hydrophilic film formed on the surface of a groove from the viewpoint of hydrophilicity in the present invention.
FIG. 8 is a diagram showing a manufacturing process of the cooling device according to one embodiment of the present invention.
FIG. 9 is a schematic view showing a step of forming a hydrophilic film on a substrate of the cooling device according to one embodiment of the present invention.
FIG. 10 is a schematic view showing a step of forming a hydrophilic film on a substrate of the cooling device according to one embodiment of the present invention.
FIG. 11 is a view showing a manufacturing process of a cooling device according to another embodiment of the present invention.
FIG. 12 is a schematic view illustrating a step of forming a hydrophilic film on a substrate of a cooling device according to another embodiment of the present invention.
FIG. 13 is a schematic view showing a step of forming a hydrophilic film on a substrate of a cooling device according to another embodiment of the present invention.
FIG. 14 is a schematic perspective view of a personal computer equipped with the cooling device of the present invention.
FIG. 15 is a schematic perspective view of a liquid crystal display equipped with the cooling device of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Cooling device 10 Substrate 20 Substrate for capacitor 30 Substrate 40 Substrate for evaporator 11 Groove 21c Groove 41 Groove 22 Heat radiation fin 150 Personal computer 160 Liquid crystal display

Claims (12)

A cooling unit that cools the object by vaporizing the working fluid by heat from the object,
A liquefaction unit that liquefies the working fluid vaporized in the cooling unit and circulates to the cooling unit;
A first flow path in which a liquefied working fluid flows from the liquefaction section to the cooling section, and a hydrophilic film is formed on a surface of the first flow path;
A second flow path for allowing the vaporized working fluid to flow from the cooling unit to the liquefaction unit. The cooling device according to claim 1,
A first substrate having a wick groove forming the cooling unit provided on a first surface;
A second substrate having a second surface joined to the first surface, wherein the second surface has grooves formed on the first surface and the second flow channel on the surface; A cooling device comprising: The cooling device according to claim 1,
The cooling device, wherein the hydrophilic film is formed by a coating process. The cooling device according to claim 1,
The cooling device, wherein the hydrophilic film is made of a material having a Si-OH group. The cooling device according to claim 1,
The cooling device, wherein the hydrophilic film is made of hydrosilsesquioxane. The cooling device according to claim 1,
The cooling device, wherein the hydrophilic film is made of alkali glass. The cooling device according to claim 1,
The contact angle between the surface of the flow path and the working fluid is 0 to 30 degrees. A cooling unit that cools the object by vaporizing the working fluid by heat from the object,
A liquefaction unit that liquefies the working fluid vaporized in the cooling unit and circulates to the cooling unit;
A first flow path in which a liquefied working fluid flows from the liquefaction section to the cooling section, and a hydrophilic film is formed on a surface of the first flow path;
An electronic apparatus, comprising: a cooling device including a second flow path through which the vaporized working fluid flows from the cooling unit to the liquefaction unit. Forming a first substrate provided with a wick groove constituting a cooling unit on the first surface;
Forming a second substrate provided with grooves forming the first flow path and the second flow path on the second surface;
Forming a hydrophilic film on the surface of the second substrate;
Bonding the first surface of the first substrate and the second surface of the second substrate so as to be in contact with each other. The method for manufacturing a cooling device according to claim 9,
The method of manufacturing a cooling device, wherein the step of forming the hydrophilic film on the second substrate is performed by a coating process. The method for manufacturing a cooling device according to claim 9,
The method of manufacturing a cooling device, further comprising a step of removing a portion other than the groove of the first flow path after applying the hydrophilic film. The method for manufacturing a cooling device according to claim 11,
The method of manufacturing a cooling device, wherein the step of removing the hydrophilic film is performed by dry etching, ashing, or oxygen plasma.

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