JP4069447B2 - Micro heat exchanger, micro cooler, micro heater, and micro thermoelectric converter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a technique for forming a close-packed structure (opal) of fine particles by utilizing self-organization of fine particles, and after the other material is filled in the gaps between the close-packed fine particles, the fine particles are removed. By using the technology to form the porous material (inverse opal) of the filling material, it is possible to cool semiconductor elements with heat generation such as micromachines, integrated circuits and light emitting elements with a fine mechanism, or to micromachines, integrated circuits and light emitting elements. This technology relates to technology that collects heat from semiconductor elements that generate heat, etc. and generates electricity, and technology that heats the reaction site in a chemical reaction system in a minute space that uses a minute space. , micro heat exchanger, the micro condenser relates to the micro heater and the micro thermoelectric converter.
[0002]
[Prior art]
For example, the following documents are available as a conventional technique for improving the efficiency of heat exchange using a porous material or a fine structure, or a conventional technique for maintaining the performance of a heat exchange mechanism using a photocatalytic effect. .
[0003]
Japanese Patent Application Laid-Open No. 2001-237355 (Patent Document 1) improves the heat transfer efficiency by laminating ceramic fine particles on one surface of a metal thin film of a heat sink.
[0004]
Japanese Patent Application Laid-Open No. 2002-53849 (Patent Document 2) discloses a small pore that allows water molecules to enter and exit the outer wall of a hollow spherical particle in a heat exchange resin having a hollow spherical structure particle having an allophane or allophane-like structure as a constituent element. A high heat exchange amount is realized by adopting a structure having
[0005]
JP 2002-71297 A (Patent Document 3) realizes hydrophilicity and deodorization by forming a coating film containing titanium oxide particles having fine pores on the surface of a fin for heat exchange. It is a thing.
[0006]
Japanese Patent Laid-Open No. 2002-71298 (Patent Document 4) realizes hydrophilicity, deodorizing property, and prevention of generation of silica odor by a coating film to which an inorganic antibacterial agent is added in addition to the above-mentioned Patent Document 3. It is.
[0007]
Japanese Patent Application Laid-Open No. 2002-81889 (Patent Document 5) discloses a small pore that allows water molecules to enter and exit the outer wall of a hollow spherical particle in a heat exchange resin comprising imogolite or a hollow spherical structure particle having an imogolite-like structure. A high heat exchange amount is realized by adopting a structure having
[0008]
JP-A-8-145485 (Patent Document 6) improves heat transfer performance by providing fine irregularities on the surface of a metal filled in a heat exchanger.
[0009]
Japanese Patent Application Laid-Open No. 10-62096 (Patent Document 7) uses a porous metal sintered body as a part for heat exchange.
[0010]
Japanese Patent Application Laid-Open No. 11-248389 (Patent Document 8) prevents a decrease in total heat exchange performance due to adhesion of dirt by providing a layer containing titanium oxide particles on the surface of a total heat exchange element.
[0011]
Japanese Patent Laid-Open No. 11-300147 (Patent Document 9) discloses that, in a total heat exchange element, a coating film containing hygroscopic particles and anti-bacterial or antibacterial particles is provided on a sheet base material to prevent the growth of wrinkles and fungi. It is a thing.
[0012]
[Patent Document 1]
JP 2001-237355 A [Patent Document 2]
JP 2002-53849 A [Patent Document 3]
JP 2002-71297 A [Patent Document 4]
JP 2002-71298 A [Patent Document 5]
JP 2002-81889 A [Patent Document 6]
JP-A-8-145485 [Patent Document 7]
JP-A-10-62096 [Patent Document 8]
JP-A-11-248389 [Patent Document 9]
Japanese Patent Laid-Open No. 11-300147
[Problems to be solved by the invention]
The background to be solved by the present invention will be described in detail.
First, the first point is related to cooling.
In recent years, techniques for cooling microcircuits, components, and mechanisms have become important with the development of micromachines and the development of integrated circuit technology, or with the increase in output and array of semiconductor lasers. In this case, there are many cases where an element for cooling (such as a Peltier element) cannot be directly attached to a heat generation source, and therefore an efficient mechanism for performing heat transfer and heat exchange is required.
[0014]
The second point is related to heating in a small system.
Heating with a small mechanism and system is mainly used in the stabilization of the characteristics of optical devices for communication, the control of biodevices using biological cells and tissues, which have recently made remarkable progress, or in fine reaction cells. It is required in the context of controlling microreactors that cause chemical reactions. The devices and mechanisms as described above have been particularly developed in recent years, and an efficient and minute heating mechanism suitable for these devices and mechanisms has not been realized.
[0015]
The third point relates to thermoelectricity that recovers heat and generates electricity.
Conventionally, the heat generated by equipment and devices has been cooled, and the recovery of heat into electricity has not been actively performed. This is obvious from the fact that cooling is performed only on elements that generate a considerable amount of heat, such as CPUs and semiconductor lasers.
[0016]
In the future, the heat of elements and mechanisms that generate heat will be recovered, and the recovered heat will be efficiently guided to the heat transfer elements, converted to electricity, stored, and used as power for other functions such as device display. Technology is required.
[0017]
An object of the present invention is to provide a micro heat exchanger, a micro cooler, a micro heater, and a micro thermoelectric converter that satisfy the above three requirements and are efficient.
[0018]
[Means for Solving the Problems]
In order to achieve the above object, the present invention is characterized by the following configuration.
a) In a micro heat exchanger in which a flow path is formed in a fine structure, and a liquid flows in the flow path to cool or heat the fine structure, a part of the flow path has good heat The conductive material is characterized in that a spherical space having the same size is gathered to form a porous body having a close-packed structure.
[0019]
b) The invention according to claim 2 is a micro heat exchanger in which a flow path is formed in a fine structure, and a liquid flows in the flow path to cool or heat the fine structure. Part of the region 1 is a porous body in which a space having a spherical shape and the same size is gathered in a good heat conductive material to form a close-packed structure, and in the flow path The other part 2 different from the above part 1 is a porous body having a close-packed structure in which spherical and identical spaces are gathered in a material having photocatalytic activity. It is characterized by being.
[0020]
c) The invention according to claim 3 is the invention according to claim 1 or 2, wherein the heat-conductive material is any one of gold, silver, copper, aluminum, tungsten, molybdenum, silicon, and carbon, or these elements as constituent elements. It is characterized by being a compound or a mixture.
[0021]
d) The invention according to claim 4 is characterized in that, in claim 2, the material having photocatalytic activity contains titanium oxide.
[0022]
e) The invention described in claim 5 is such that the cooling element is in contact with or bonded to an arbitrary region of the micro heat exchanger of any one of claims 1 to 4 constituted by the good heat conductive material. It is characterized by.
[0023]
f) The invention according to claim 6 is such that a heating element is in contact with or bonded to a part of the region constituted by the good heat conductive material of the micro heat exchanger according to any one of claims 1 to 4. It is characterized by that.
[0024]
g) The invention according to claim 7 is such that a thermoelectric conversion element is brought into contact with or bonded to a part of the portion constituted by the good heat conductive material of the micro heat exchanger according to any one of claims 1 to 4. It is characterized by that.
[0028]
DETAILED DESCRIPTION OF THE INVENTION
The present invention is a micro heat exchanger utilizing a so-called “inverse opal”, a micro heat exchanger, a micro cooler, a micro heater, A micro thermoelectric converter is proposed.
[0029]
First, “inverse opal” will be described.
Inverse opal, first, as shown in FIG. 1, a particle aggregate (opal) in which spherical particles having the same size (spherical monodisperse particles) 12 are arranged in a close-packed structure on a substrate 11. Next, as shown in FIG. 2, after filling the voids between the particles of the particle assembly with a material (filler) different from the material of the particles, the particles with the above close packed structure arrangement are removed. And make the inside hollow.
[0030]
This inverse opal has properties different from those of conventional porous bodies and porous materials because the inner space (void) has a close-packed structure. That is, about 70% of the inverse opal is a space (void) in the entire volume, and has a large surface inside.
[0031]
Inverse opal, when focusing on the individual spherical spaces that make up the porous body, the 12 nearest spherical voids are in contact with the neighboring spherical space around one spherical void. Therefore, it has sufficient flow paths inside the porous body.
[0032]
In the present invention, by providing a heat exchange part of an inverse opal based on a highly conductive material in a fine flow path, a small, The efficiency of exchange allowed a good heat exchanger.
[0033]
The flow path connecting the heat exchanging parts using inverse opal may be assembled with a fine tube or the like, but it may be suitable for the present invention to be formed integrally with the heat exchanging part using micromachine technology. it is conceivable that.
[0034]
Further, in the present invention, by providing an inverse opal structure based on a material having photocatalytic activity in a fine channel, the contamination of the liquid flowing in the channel due to the growth of microorganisms is prevented, and as a result It is possible to prevent contamination of the heat exchange portions connected by the flow channel and the flow channel, and to prevent performance deterioration due to clogging of the heat exchanger due to contamination.
[0035]
Of the above prior art documents, the closest to the present invention is JP-A-10-62096 (Patent Document 7). However, in the document described in Patent Document 7, the porosity is 7 to However, in the present invention, by using inverse opal, the porosity is approximately 70%, and the conductance to the fluid can be greatly improved compared to the conventional porous material. Is possible. Moreover, since the basic process is a thin film process, the present invention is suitable for forming a fine system.
[0036]
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
Example 1
In the present embodiment, examples in which the inventions of claims 1, 3, and 9 are implemented will be described.
[0037]
First, spherical monodispersed silica particles with a particle size of 100 nm were dispersed in benzene, and 3-mercaptopropyltrimethoxysilane (MPTMS) was dissolved in this, and the concentration was adjusted to 1.0 × 10-2 M, and the mixture was stirred in a nitrogen atmosphere for 30 minutes. Then, centrifuge at 3000 rpm for 30 minutes, re-disperse the precipitate in benzene, and centrifuge at 3000 rpm for 30 minutes.
[0038]
The centrifugally separated precipitate is redispersed in chloroform, centrifuged at 3000 rpm for 30 minutes, the precipitate is redispersed in methanol, centrifuged at 3000 rpm for 30 minutes, the precipitate is redispersed in pure water, and centrifuged. 3,000 rpm for 30 minutes to redisperse the precipitate in pure water.
[0039]
Through the above steps, an aqueous dispersion of silica particles whose surface is terminated with a thiol group is obtained. Thereafter, the dispersion medium is replaced with ethanol from water, and the concentration is adjusted to 2 wt% to obtain a raw material liquid for forming a fine particle structure.
[0040]
Next, as shown in FIG. 3, the Si wafer (substrate) 11 with an oxide film is dipped in the raw material liquid 13 made as described above, and pulled up at a constant speed. The pulling speed is 0.05 to 100 μm / s, and a good thin film-like fine particle structure can be formed on the Si wafer (substrate) 11 with an oxide film.
[0041]
Next, after being immersed in a toluene solution of gold nanoparticles having an average particle diameter of 5 nm for 1 hour, heat treatment is performed at 700 ° C. for 30 minutes.
[0042]
Thereafter, the fine particle structure processed into an arbitrary shape is immersed in an electroless plating solution of copper to deposit copper in the voids of the particles, and then copper is filled between the particles by reactive ion etching. The fine particle structure is processed into a desired shape. In this embodiment, as shown in FIG. 4, the fine particle structure is left only in the two rectangular regions shown as the regions 14 where the fine particle structure remains. At this time, the region to be etched (region other than the region 14) is removed up to the oxide film on the Si wafer.
[0043]
Thereafter, copper is deposited on the “copper deposition region 15” shown in FIG. 5 by sputtering using a mask.
[0044]
Next, after immersing in 2% hydrofluoric acid to remove the silica particles in the region 14 to make the portion hollow, the resist is left in the “resist leaving region 16” shown in FIG. The silicon oxide film is formed on the “silicon oxide film formation region 17” shown in FIG. 7 by sputtering, and then the resist in the region 16 is removed. Thereby, a flow path is formed in the region 16.
[0045]
Next, copper is deposited on the “copper deposition region 151” shown in FIG. 8 by sputtering using a mask. This is because the height of the heat exchange region is increased to facilitate the coupling with an element for heat exchange.
[046]
Through the above steps, as shown in FIG. 9, two heat exchange regions 18 and a heat exchanger in which they are connected by a flow path 19 can be formed. Since a method for forming a micropump for operating as a heat exchanger and a method for sealing a refrigerant can be implemented by a conventional micromachine technique, description thereof is omitted here.
[0047]
(Example 2)
In the present embodiment, examples in which the inventions of claims 2, 3, 4, 5, and 8 are implemented will be described.
[0048]
Use spherical monodispersed silica particles with a particle size of 100 nm. The raw material liquid adjustment method and the fine particle structure forming method for forming the fine particle structure are the same as those in Example 1. As in Example 1, the formed fine particle structure was immersed in a toluene solution of gold nanoparticles having an average particle diameter of 5 nm for 1 hour, and then heat-treated at 700 ° C. for 30 minutes.
[0049]
Thereafter, the fine particle structure is processed into a desired shape by reactive ion etching. In this embodiment, as shown in FIG. 10, the fine particle structure is left in the region 22 where three rectangular fine particle structures are left. At this time, the region to be etched (region other than the region 22) is removed up to the oxide film on the Si wafer substrate 21.
[0050]
Next, using a photosensitive resin, the fine particle structure at a location indicated by “resin-coated region 231” in FIG. 11 is coated with the resin.
[0051]
Thereafter, it is immersed in an electroless plating solution of copper, and copper is deposited in the voids of the particles in two regions indicated by 22 in FIG. Thereafter, the resin is removed, and the fine particle structure at the location indicated by “region 232 covered with resin” in FIG. 12 is newly covered with resin.
[0052]
The sample in this state is immersed in a solution obtained by dissolving titanium alkoxide in dehydrated ethanol, and then pure water is added to start the reaction. Since titanium hydroxide nuclei formed by the reaction are preferentially formed on the surface of silicon oxide, titanium oxide can be formed only in the voids of the particles in the region indicated by 221 in FIG.
[0053]
Thereafter, after ion implantation of tungsten, the resin is removed and heat treatment is performed at 700 ° C. for 30 minutes. The above process is a process for giving sensitivity up to the visible range that pure titanium oxide is effective only for ultraviolet light.
[0054]
Next, after immersing in 2% hydrofluoric acid to remove the silica particles to make the part hollow, copper is applied to the "copper film forming region 24" part of FIG. 13 by sputtering using a mask. Form a film. Thereafter, the resist is left in the “resist leaving region 25” shown in FIG. 14, and a silicon oxide film is formed on the portion shown by “silicon oxide forming region 26” in FIG. 15 by sputtering using a mask. To do.
[0055]
Next, using a mask, copper is deposited on the portion indicated by “copper deposition region 24” shown in FIG. 16 by sputtering. This is because the height of the heat exchange region is increased to facilitate the coupling with an element for heat exchange.
[0056]
Through the above steps, two heat exchange regions, one photocatalyst region, and a heat exchanger connecting them with a flow path could be formed. As shown in FIG. 17, a Peltier element was attached to one of the two heat exchange regions, and a cooler could be formed. An element to be cooled is attached to the other heat exchange region. Similar to the first embodiment, the micropump formation method and the refrigerant sealing method can be performed by a conventional micromachine technique, and thus the description thereof is omitted here.
[0057]
(Example 3)
In the present embodiment, examples in which the inventions of claim 2, claim 3, claim 4, claim 6, and claim 10 are implemented will be described.
[0058]
Use spherical monodispersed silica particles with a particle size of 100 nm. The method for adjusting the raw material liquid for forming the fine particle structure is the same as that in Example 1.
[0059]
The substrate is a Si wafer substrate with an oxide film, immersed in a 1 vol% solution of octadecyltrichlorosilane (OTS) in toluene for 5 minutes in a nitrogen atmosphere, and baked at 120 ° C for 10 minutes. Thereafter, UV light irradiation is performed using a mask only at a position where a fine particle structure is to be formed. Then, after immersing in a 1 vol% toluene solution of (aminopropyl) triethoxysilane (APTS) for 1 hour, it is baked at 120 ° C. for 10 minutes.
[0060]
As shown in FIG. 3, this substrate is immersed in the raw material solution and pulled up at a constant speed. The pulling speed is 0.05 to 100 μm / s, and a good thin film-like fine particle structure can be formed only in the region irradiated with UV on the substrate.
[0061]
Next, after being immersed in a toluene solution of gold nanoparticles having an average particle diameter of 5 nm for 1 hour, heat treatment is performed at 700 ° C. for 30 minutes. The subsequent steps up to the formation of the heat exchanger are the same as in Example 2.
[0062]
As shown in FIG. 18, the heater element 30 is attached to one of the two heat exchange regions of the formed heat exchanger. In the figure, 27 is a photocatalyst portion, and 29 is a flow path.
[0063]
Example 4
In the present embodiment, examples in which the inventions of claims 2, 3, 4, 7, and 10 are implemented will be described.
[0064]
The steps up to the formation of the heat exchanger are the same as in the second embodiment.
As shown in FIG. 19, the thermoelectric conversion element 31 was attached to one of the two heat exchange regions of the formed heat exchanger, and the thermoelectric converter could be formed. An element for recovering heat is attached to the other heat exchange region. In the figure, 27 is a photocatalyst portion, and 29 is a flow path.
[0065]
【The invention's effect】
The effects of the present invention will be described below for each claim.
a) According to the micro heat exchanger according to claim 1, a porous body having a close-packed structure in which spherical spaces having the same size are gathered in a good heat conductive material is used. As a result, it is possible to improve the efficiency of heat exchange while maintaining the magnitude of conductance for flowing the liquid.
[0066]
According to the micro heat exchanger according to claim 2, in the region 1, a porous body having a close-packed structure in which spherical spaces having the same size are gathered in a good heat conductive material is used. By doing so, it is possible to improve the efficiency of heat exchange while maintaining the magnitude of conductance for flowing liquid, and at the same time, in region 2, the material having photocatalytic activity is spherical, In addition, by using a porous body in which spaces having the same size are gathered to form a close-packed structure, contamination of the liquid due to the propagation of microorganisms and the like can be prevented, and It becomes possible to prevent the porous body from being soiled.
[0067]
According to the micro heat exchanger according to claim 3, the good heat conducting material is gold, silver, copper, aluminum, tungsten, molybdenum, silicon, carbon, or a compound containing these elements as constituent elements. Alternatively, good heat transfer is possible by using a mixture.
[0068]
According to the micro heat exchanger of the fourth aspect, the material having photocatalytic activity contains titanium oxide, so that visible to ultraviolet light is used to prevent contamination of the liquid due to the propagation of microorganisms. It is possible to prevent the porous body in the path and the region 1 from being contaminated.
[0069]
According to the micro cooler described in claim 5, the cooling element such as the Peltier element or the air cooling fin is brought into contact with or coupled to the portion constituted by the good heat conductive material of the micro heat exchanger, so that the cooling element It becomes possible to cool a device or a structure in a remote place.
[0070]
According to the micro heater described in claim 6, a heating element such as a heater is brought into contact with or coupled to a portion constituted by a good heat conductive material of the micro heat exchanger, so that a place away from the heating element can be obtained. It is possible to heat devices, structures and minute cells for chemical reactions.
[0071]
According to the micro thermoelectric converter according to claim 7, heat is generated from the micromachine, the semiconductor light emitting element, or the like by bringing the thermoelectric conversion element into contact with or being bonded to the portion formed of the good heat conductive material of the micro heat exchanger. It is possible to recover the heat of the device accompanied by the device at a position away from the device and convert it into electricity.
[Brief description of the drawings]
FIG. 1 is a diagram for explaining a close-packed structure particle structure (opal).
FIG. 2 is a diagram for explaining inverse opal;
FIG. 3 is a view showing a method of forming a thin film fine particle structure.
FIG. 4 is a view showing a region where a fine particle structure remains (plan view).
FIG. 5 is a view showing a copper film formation region (plan view).
FIG. 6 is a view showing a region where a resist is left (plan view).
FIG. 7 is a view showing a silicon oxide film formation region (plan view).
FIG. 8 is a view showing a copper film formation region (plan view).
FIG. 9 is a view showing a micro heat exchanger (plan view).
FIG. 10 is a view showing a region where a fine particle structure remains (plan view).
FIG. 11 is a view showing a region covered with resin (plan view).
FIG. 12 is a view showing a region covered with resin (plan view).
FIG. 13 is a diagram showing a copper film formation region (plan view).
FIG. 14 is a view showing a region where a resist is left (plan view).
FIG. 15 is a view showing a silicon oxide film formation region (plan view).
FIG. 16 is a diagram showing a copper film formation region (plan view).
FIG. 17 is a diagram showing a configuration of a micro cooler.
FIG. 18 is a diagram showing a configuration of a micro heater.
FIG. 19 is a diagram showing a configuration of a micro thermoelectric converter.
[Explanation of symbols]
11, 21: Substrate 12: Spherical monodisperse particles 13: Raw material liquids 14, 22: Regions 15, 151, 24, 241: Copper film-forming regions 16, 25: Regions for resist 17: Silicon oxide film Formation area 18: Heat exchange areas 19, 29: Channels 231, 232: Area covered with resin 26: Silicon oxide formation area 27: Photocatalyst portion 28: Peltier element 30: Heater 31: Thermoelectric conversion element

Claims (7)

In a micro heat exchanger that cools or heats a fine structure when a flow path is formed in the fine structure and a liquid flows in the flow path,
A part of the flow path is a porous body having a close-packed structure in which spherical spaces having the same size are gathered in a good heat conductive material. Exchanger. In a micro heat exchanger that cools or heats a fine structure by forming a flow path in the fine structure and flowing a liquid in the flow path,
Part of the region 1 in the flow path is a porous body having a close-packed structure in which spherical and identical spaces are gathered in a good heat conductive material, and The porous body in which a part of the region 2 other than the region 1 in the flow path is a close-packed structure in which spherical spaces having the same size are gathered in a material having photocatalytic activity A micro heat exchanger characterized in that The micro heat exchanger according to claim 1 or 2,
The good heat conductive material is any one of gold, silver, copper, aluminum, tungsten, molybdenum, silicon, and carbon, or a compound or mixture containing these elements as constituent elements. . The micro heat exchanger according to claim 2,
The micro heat exchanger, wherein the material having photocatalytic activity contains titanium oxide.   5. A micro-cooling, wherein a cooling element is in contact with or coupled to an arbitrary region of the portion constituted by the good heat conductive material of the micro heat exchanger according to claim 1. vessel.   5. A micro heat exchanger comprising: a micro heat exchanger according to claim 1, wherein a heat generating element is in contact with or coupled to a part of a region constituted by the good heat conductive material of the micro heat exchanger according to claim 1. Heater. A thermoelectric conversion element is brought into contact with or coupled to a part of a portion constituted by the good heat conductive material of the micro heat exchanger according to any one of claims 1 to 4. Micro thermoelectric converter.

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