JP4192450B2 - Manufacturing method of microchannel structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a microchannel structure suitable for performing chemical physical operations such as liquid feeding, chemical reaction, analysis, separation, extraction, and detection in a microchannel.
[0002]
[Prior art]
In recent years, a microchannel structure having a microchannel having a length of about several centimeters on a glass substrate of several cm square and a width and depth of sub-μm to several hundred μm is used. A so-called integrated chemical laboratory that performs chemical and physical operations such as fluid feeding, chemical reaction, analysis, separation, extraction, and detection is drawing attention. Such an integrated chemical laboratory can perform efficient chemical reactions due to the effects of a short molecular diffusion distance in a minute space and a large specific interfacial area, and from reaction to separation, extraction, and detection are consistent. There are merits such as speeding up various research and development, labor saving, resource saving, energy saving, space saving, further reduction of experimental waste liquid and waste, rationalization of repeated experiments. FIG. 1 shows an example of a microchannel structure with one inlet and two outlets, and FIG. 2 shows an example of a microchannel structure with two inlets and two outlets. ing.
[0003]
Such a microchannel structure can shorten the diffusion distance of molecules due to the narrow space in the Y-shaped microchannel with two input ports and one output port, When an interface formed by introducing two different liquids is generated, the reaction efficiency and reaction time can be shortened by easily increasing the specific interface area. Furthermore, it is possible to integrate various chemical reactions and separations by combining microchannel structures having such characteristics or by increasing or decreasing the number of input / output ports.
[0004]
As an example showing these, “Micromachining of Capillary Electrophoresis Injectors and Separators on Glass Chips and Evaluation of Flow at Capillary Interceptions. There is disclosed a flow path formed by performing groove processing on a substrate and then welding a borosilicate glass substrate as a cover body by heating. However, in this method, the inner wall of the flow channel in contact with the liquid reagent is determined by the concavo-convex substrate material and the cover body, so the liquid feeding reagent is basically based on the chemical resistance or adhesion of the glass that is the flow channel structure forming material. Is limited. Moreover, in the microchannel structure formed of resin, there is a problem that the upper limit of the liquid feeding pressure is limited by the thickness and adhesive strength of the cover body.
[0005]
Conventionally, the flow path cross-sectional structure of the micro flow path structure is configured by an adhesive substance depending on the substrate on which the flow path pattern is created and the cover body material and sealing method for sealing the substrate. No consideration was given to structural durability and chemical resistance.
[0006]
Furthermore, when wiring a conductive material or semiconductor material to combine and functionalize sensors, heating elements, etc., it is realized by performing wiring processing by etching or the like on the surface of the cover body or in the vicinity of the flow path on the uneven substrate. However, in this method, there is a problem that data accuracy and temperature controllability occur because the distance from the inside of the flow path for sensing or heating is increased.
[0007]
In addition, in order to give an electrical, chemical, magnetic, and physical function to a microchannel structure made of glass material or resin, it can be placed inside or outside the channel, with metal, oxide, semiconductor, It is necessary to pattern molecules. Specifically, for example, there are a heater, a cooling function, a temperature sensor, a magnetic field applying element, an electric field applying element, a piezoelectric element, a discharge tube, and the like. Some of these functions require direct wiring into the channel walls, but this has not been realized at present.
[0008]
[Problems to be solved by the invention]
The object of the present invention has been proposed in view of such conventional situation, and the flow channel structure strength is obtained by forming a thin film layer structure in a cylindrical shape on the flow channel wall surface for flowing a fluid such as liquid or gas. Improvement of chemical resistance, induction of electrochemical phenomena in fluids of liquids and gases by wiring to the channel wall surface, improvement of measurement accuracy of electric field, magnetic field, temperature, etc., fluid heating accuracy, catalytic reaction, etc. It is an object of the present invention to provide a micro flow channel structure capable of promoting the chemical reaction.
[0009]
[Means for Solving the Problems]
In order to solve the above problems, the present inventors have formed a micro flow path in which a micro flow path is formed on the surface of a substrate and a structure body is formed by overlapping the cover body with or without a through hole in the substrate. In the road structure, the inner wall surface of the micro-channel is made of a layer structure made of one or more materials, so that the problems of the micro-channel structure according to the above-described conventional technology can be solved, and the present invention is finally completed. I was able to.
[0010]
Hereinafter, the present invention will be described in detail.
[0011]
The present invention has a micro-channel for filling or moving a fluid such as gas or liquid therein, and the inner wall surface of the micro-channel has a layer structure made of one or more kinds of materials. This is a microchannel structure.
[0012]
Here, the material of the microchannel structure itself of the present invention may be appropriately selected according to the purpose. Examples thereof include inorganic materials such as soda glass and quartz glass, and polymer materials such as resins. It is done. In addition, as a method for forming a micro flow channel on the substrate, a shape corresponding to the purpose may be appropriately formed by the method described in Examples.
[0013]
The microchannel structure of the present invention is formed by laminating and laminating the above microchannel substrate and the cover body, and laminating and integrating the substrate, and the substrate material and the cover body on the whole or a part of the inner wall surface. One or more types of materials that are different or the same as the materials are formed in layers.
[0014]
As a method for forming a layer, a method in which the layer is formed in advance before bonding and then superposed and bonded, a polymer material such as PC (polycarbonate), which is a layer formed after the bonding, Ni, Cr Metals such as Au, metals such as alloys, and metal compounds such as metal oxides may be introduced. More specifically, it can be formed by sequentially forming a desired thin film by introducing a UV curable resin, a thermosetting resin, an organometallic complex, and an electroless plating solution. Among these, metals and metal compounds can be formed by coexisting them. In addition, when a UV curable resin, a thermosetting resin, or an organometallic complex is used, it is possible to selectively form a layer structure at an arbitrary position in the longitudinal direction of the flow path.
[0015]
Further, when the microchannel structure of the present invention is provided with an inlet for introducing a fluid and an outlet for discharging the fluid, a cover body having a through hole, a substrate having a microchannel, May be laminated and bonded together to integrate the layers.
[0016]
Furthermore, the microchannel structure according to the present invention is sealed not only in a structure in which the microchannel having an opening such as an introduction port and a discharge port communicates with the outside world, but also in the interior of the structure. Structure is also included. In the microchannel structure having such a sealed structure, a filler according to the purpose is introduced from the fluid inlet of the microchannel structure having an open structure, and then the opening of the microchannel structure is opened. It can be obtained by a method in which a UV curable resin, a thermosetting resin or the like is further introduced, and this is thermally fused or cured to be sealed.
[0017]
FIG. 3 is a cross-sectional view of various channel structures as an example of the microchannel structure described above. 3A to 3C, the cover body 2 is superimposed on the substrate 8 on which the predetermined material is applied in a layered manner on the inner wall of the microchannel and the channel inner wall layer 7 is formed. Are pasted together.
[0018]
FIG. 3D shows, for example, a cover 8 that is laminated and bonded to a substrate 8 on which a predetermined material is applied on both sides in the flow direction of the microchannel to form a thin film. It is.
[0019]
As described above, in the microchannel structure according to the present invention, a thin film can be selectively formed in a part of the channel that merges from a plurality of input port channels. It is also possible to realize a light emitting function by introducing not only a liquid but also a gas into the flow path, for example, by introducing a light emitting substance and discharging it.
[0020]
As a specific example of the formation method, as shown in FIG. 4, when the electroless plating solution 21 and pure water 22 are introduced into the microchannel having the microprotrusions 23, the microprotrusions 23 are not used as boundaries. A laminar flow is generated by the three solutions of the electroplating solution 21 and the pure water 22, and these solutions do not mix with each other. By the generation of this laminar flow, an electroless plating metal thin film is formed only on both sides of the flow path with each projection as a boundary. The electroless copper plating inlet 24, the two electroless copper plating outlets 26, and the pure water outlet 27 of the microchannel structure in which the metal thin film is formed are sealed, and the pure water inlet 25 is vacuumed by a vacuum pump. And Thereafter, a small amount of a light emitting gas such as neon, argon, carbon dioxide gas or an additive such as mercury necessary for light emission is introduced, and the pure water inlet 25 is sealed. A so-called neon tube can be formed by using the copper plating portion (the flow path inner wall layer 7 in FIG. 3D) as a discharge electrode.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited only to these examples.
[0022]
Example 1
As shown in FIG. 5, a micro-channel resin molded body was prepared by forming Cr 20 nm and Au 100 nm on a soda glass substrate having a thickness of 8 mm and a diameter of 200 mm by a DC sputtering method, and then applying 8900 D resist 8 μm made by Tokyo Ohka Kogyo Co., Ltd. Was applied to prepare a glass master. A photomask on which a linear pattern having a width of 50 μm and a length of 50 mm shown in FIG. 6 was placed on the original glass master, subjected to batch exposure with a UV exposure apparatus, developed, and subjected to patterning.
[0023]
Next, the portion where the gold thin film surface is exposed by patterning is etched with an iodine / ammonium iodide mixed solution to expose the Cr surface. The Cr thin film was etched with a cerium nitrate diammonium cerium nitrate Ce (NH ₄ ) ₂ (NO ₃ ) ₆ solution to expose the glass surface. The glass master was immersed in a 50% hydrofluoric acid aqueous solution for 10 minutes to form a flow path having a width of 250 μm and a depth of 100 μm as shown in FIG. 7, and then the etching mask film 8900D, Au, and Cr were removed to remove only the glass surface. An exposed glass master was created.
A Ni thin film having a thickness of 800 nm was formed on the glass master by DC sputtering, and then immersed in a sulfamic acid Ni electroforming solution to form a 300 μm Ni stamper by electroforming. A PC resin molding was prepared by injection molding using the Ni stamper.
[0024]
A PC resin cover body having a thickness of 100 μm, in which a through hole having a diameter of 0.5 mm was previously formed at a predetermined position, was pressure-welded in a 145 ° C. atmosphere on a resin molded substrate subjected to patterning treatment.
The resin molded article having a hollow structure was connected to the inlet / outlet port and the capillary tube by an adapter via an O-ring, and a syringe pump was used to inject SD-318 made of Mitsubishi Rayon, which is a UV curable resin. After confirming that SD-318 spreads throughout the microchannel, nitrogen gas was filled in place of SD-318 in the syringe and the microchannel was purged with nitrogen. With the inside of the flow channel purged with nitrogen, UV light was exposed for 10 minutes to photocure SD-318 adhering to the flow channel wall surface. FIG. 8 shows an enlarged view of the channel cross-sectional structure.
[0025]
Ethyl acetate was continuously fed to the prepared microchannel at a flow rate of 100 μl / min and a pumping pressure of 1 MPa for 1 hour, but no chemical change or damage to the cover layer occurred in the microchannel.
[0026]
Comparative Example 1
A PC resin cover body having a thickness of 100 μm in which a through hole having a diameter of 0.5 mm was previously formed at a predetermined position was pressure-welded in a 145 ° C. atmosphere to the resin molded substrate subjected to the patterning process created in Example 1. When the flow path wall surface coating with UV curable resin was not performed on the micro-channel molded body, ethyl acetate was fed at a flow rate of 50 μl / min. As a result, the micro-channel instantly became cloudy and finally thermally welded. The sheet melted and liquid leakage occurred. Further, when pure water was fed at a flow rate of 100 μl / min and a feeding pressure of 1 MPa, the cover at the flow path portion was peeled off.
[0027]
Example 2
A PC resin cover body having a thickness of 100 μm, in which a through hole having a diameter of 0.5 mm was previously created at a predetermined position, was formed in the patterned resin molded substrate prepared in Example 1 in a 145 ° C. atmosphere and a pressurized state. It was allowed to stand for 45 minutes for welding. After the Au electroless plating solution was fed to the microchannel structure at a flow rate of 100 μl / min for 5 minutes, the substrate cross section was broken and the cross section was observed with a SEM (secondary electron microscope). It was confirmed that an Au thin film was formed on the wall surface. Ethyl acetate was fed into the microchannel molding at a flow rate of 100 μl / min, but no chemical change appeared in the microchannel.
[0028]
Example 3
SD-318UV curable resin manufactured by Mitsubishi Rayon on the adhesive surface side of the injection molded body substrate prepared in Example 1 and a PC resin cover body having a thickness of 100 μm in which a 0.5 mm diameter through-hole was previously created at a predetermined position. Was applied by spin coating. After the coated surfaces were bonded together, they were cured by exposure for 10 minutes with a UV lamp. Ethyl acetate was fed into the microchannel molding at a flow rate of 100 μl / min, but no chemical change appeared in the microchannel.
[0029]
Example 4
After the Au electroless plating solution was fed to the microchannel structure created in Example 1 at a flow rate of 100 μl / min for 5 minutes, the substrate cross section was broken and the cross section was observed with a SEM (secondary electron microscope). As a result, it was confirmed that the multilayer structure of the SD-318 / Au thin film was formed in a cylindrical shape on the channel wall surface. Although an ethyl acetate solution was fed into the microchannel at a flow rate of 100 μl / min, no chemical change appeared in the microchannel.
[0030]
Example 5
A film formation mask as shown in FIG. 9 was placed on the resin-molded substrate subjected to the patterning process created in Example 1. Using this method, a 200 nm SiO ₂ thin film was formed by RF sputtering within a width of 0.5 mm from the flow path. Similarly, the same mask was placed on the cover body to form a 200 nm SiO ₂ thin film. The resin molded substrate prepared by the above method and the SiO ₂ thin film pattern of the cover body were sandwiched so as to coincide with each other, and were left to stand for 2 hours and 45 minutes in a 145 ° C. atmosphere and under pressure to perform welding. Although an ethyl acetate solution was fed into the microchannel at a flow rate of 100 μl / min, no chemical change occurred in the microchannel.
[0031]
Example 6
A film formation mask as shown in FIG. 9 was placed on the resin-molded substrate subjected to the patterning process created in Example 1. Using this technique, a NiCr thin film having a thickness of 500 nm was formed by a DC sputtering method within a width of 0.5 mm from the flow path portion. Similarly, the same mask was placed on the cover body to form a NiCr thin film having a thickness of 500 nm. The resin molded substrate prepared by the above method and the NiCr thin film pattern of the cover body were sandwiched so as to coincide with each other, and were left to stand for 2 hours and 45 minutes in a 145 ° C. atmosphere and under pressure to perform welding. Wiring was applied on the NiCr thin film exposed at the input / output port of the flow path, and voltage was applied to confirm that pure water reached 80 ° C.
[0032]
Example 7
A pattern having a convex portion at the bottom of the flow path as shown in FIG. 10 is created on the resin molded substrate, and the input / output flow path has three widths of 100 μm, depth of 100 μm, length of 15 mm, width of 300 μm, depth of 100 μm, and length of 40 mm. A confluence channel was obtained. By simultaneously feeding 100 μl / min of Cu electroless liquid to both sides of these three channels and 100 μl / min for 5 min of pure water to the center channel, a Cu thin film layer is formed only on both sides of the center channel. The formation of was confirmed. In FIG. 10 of this microchannel structure, electrical wiring was applied so that a voltage could be applied to ports 1 and 3, and a sodium hydroxide aqueous solution was fed at 100 μl / min to apply the voltage. Generation of a mixed gas of hydrogen and oxygen was confirmed at ports 1 ′, 2 ′, and 3 ′.
[0033]
【The invention's effect】
The microchannel structure of the present invention is different from or the same as the substrate material and the cover body material on the whole or a part of the surface of the inner surface of the microchannel obtained by bonding the substrate on which the microchannel is formed and the cover body. At least one kind of material is structured in layers, preventing corrosion of the flow channel wall surface by fluid such as liquid or gas gas, improving flow channel strength by hydraulic pressure or gas pressure, and chemical reaction such as catalytic reaction Can be promoted. In addition, when a structure in which a microfluid is sealed inside the structure is applicable to a so-called neon tube or the like, it is industrially useful.
[Brief description of the drawings]
FIG. 1 is a diagram showing an example of a microchannel structure.
FIG. 2 is a view showing a microstructure having two introduction ports and two discharge ports.
FIG. 3 is a diagram showing various cross-sectional structures of a microchannel.
FIG. 4 is an explanatory diagram for forming the microchannel of FIG. 3 (d).
FIG. 5 is a diagram showing a method for creating a microchannel structure.
FIG. 6 is a diagram showing a mask used during batch exposure.
FIG. 7 is a view showing a minute channel structure.
FIG. 8 is a diagram showing a cross-sectional structure of a microchannel.
FIG. 9 is a view showing a sputtering mask used during film formation.
10 is a view showing a microchannel structure in Example 7. FIG.
[Explanation of symbols]
1: Microchannel 2: Cover body 3: Microchannel substrate 4: Introduction port 5: Discharge port 6: Through hole 7: Channel inner wall layer 8: Substrate 9: Soda glass 10: Photoresist 11: Metal thin film layer Cr / Au
12: Photomask for surface 13: Ni
14: Stamper 15 for surface 15: Mold 16: Resin 17: Substrate on which an uneven pattern is formed 18: Cover body (made of PC resin)
19: PC resin 20: UV curable resin layer 21: Electroless copper plating solution 22: Pure water 23: Minute protrusion 24: Electroless copper plating solution inlet 25: Pure water inlet 26: Electroless copper plating solution outlet 27 : Pure water outlet

Claims (2)

A micro flow comprising an introduction port for introducing a fluid and a discharge port for discharging a fluid, and a cover body having a through hole and a substrate having a micro flow path are laminated and bonded together, and are laminated and integrated. In the channel structure, the microchannel has a microprotrusion at the bottom, and an electroless plating solution is introduced on both sides of the microchannel and pure water is introduced into the center of the channel, so that a laminar flow state A method for producing a microchannel structure, comprising forming an electroless plating metal thin film only on both sides of the channel with a protrusion at the lower portion of the microchannel as a boundary. There are two protrusions at the bottom of the micro-channel, electroless plating solution is introduced on both sides of the micro-channel, and pure water is introduced into the center of the channel to send a laminar flow consisting of three liquids. 2. The method of manufacturing a microchannel structure according to claim 1 , wherein an electroless-plated metal thin film is formed only on both sides of the channel with a protrusion at a lower portion of the microchannel as a boundary.

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