WO2018216673A1

WO2018216673A1 - Microchip

Info

Publication number: WO2018216673A1
Application number: PCT/JP2018/019577
Authority: WO
Inventors: 真和佐本; 基裕酒井; 鈴木　信二
Original assignee: ウシオ電機株式会社
Priority date: 2017-05-23
Filing date: 2018-05-22
Publication date: 2018-11-29
Also published as: JP6801584B2; JP2018197663A

Abstract

The objective of the present invention is to provide a microchip in which a high-strength joining state is achieved in a joint portion of two substrates. A microchip (10) is formed by joining a first microchip substrate (11) and a second microchip substrate (16) together, and internally includes a flow passage (R) which allows an injection port and a discharge port, provided in a top surface of the first microchip substrate, to communicate with one another, and which comprises a flow passage channel formed in at least one of the first microchip substrate and the second microchip substrate. The microchip (10) is characterized in that between the first microchip substrate and the second microchip substrate are formed inside joint portions (21, 22) formed along the flow passage, and an outside joint portion formed along outer peripheral edge portions of each of the first microchip substrate and the second microchip substrate, and in that a sealed space (S) is formed between the inside joint portions and the outside joint portion in such a way as to surround the flow passage.

Description

Microchip

The present invention relates to a microchip, and more specifically, a first microchip substrate and a second microchip substrate are bonded to each other, and between the first microchip substrate and the second microchip substrate. The present invention relates to a microchip in which a flow path is formed.

In recent years, in the biochemical field, a technique for separating, synthesizing, extracting or analyzing a trace amount of reagent using a microreactor has attracted attention. This microreactor is composed of a microchip in which a microscale analysis channel or the like is formed on a small substrate made of, for example, silicon, silicone resin or glass by a semiconductor microfabrication technique.
A reaction analysis system using such a microreactor is called a micro total analysis system (hereinafter referred to as “μTAS”). According to this μTAS, since the ratio of the surface area to the volume of the reagent is increased, it is possible to perform reaction analysis with high speed and high accuracy, and it is possible to realize a compact and automated system.

In addition, the microchip used for μTAS typically has a structure in which a pair of microchip substrates are bonded to face each other. A fine channel groove is provided on the bonding surface of at least one of the microchip substrates, and the channel groove forms a micro channel (for example, a width of about 10 to several thousand μm and a depth of about 10 to several thousand μm). Is formed. As a microchip substrate, a glass substrate is mainly used because it is easy to manufacture and can be optically detected. Recently, development of a microchip using a resin substrate that is lightweight but is less likely to be damaged than a glass substrate and that is inexpensive.

In manufacturing a microchip, as a method for joining two microchip substrates, a method using an adhesive or a method using thermal fusion may be considered. However, these methods have the following problems.
In the method of joining two microchip substrates with an adhesive, the adhesive oozes out into the space constituting the microchannel and the microchannel is blocked, or a part of the space constituting the microchannel is narrow. Thus, there is a problem that the diameter of the micro flow path becomes non-uniform, and the uniform characteristics of the flow path wall surface are disturbed. In addition, the obtained microchip (joint) has a problem that peeling occurs between both substrates in a high temperature and high humidity environment.
Also, in the method of joining two microchip substrates by thermal fusion, the flow channel groove is crushed in the heating stage when the fusion is performed at a temperature higher than the heat melting temperature, or the flow channel groove has a predetermined cross-sectional shape. Therefore, there is a problem that it is difficult to increase the functionality of the microchip.
Therefore, in recent years, a method has been proposed in which the bonding surface of the microchip substrate is activated by irradiating the bonding surface of the microchip substrate with ultraviolet rays, and then bonded by bonding the microchip substrates (for example, Patent Document 1 to Patent Document 4).

JP 2006-187730 A JP 2008-19348 A International Publication No. 2008/087800 Japanese Patent No. 5152361

However, it has been found that the known method for joining two substrates using ultraviolet rays has the following problems.
That is, even if the conditions such as the illuminance of ultraviolet rays irradiated to the bonding surfaces of the substrates, the pressure applied when bonding the substrates, the heating temperature, and the heating time are managed with high accuracy, the bonded state of the obtained bonded body is obtained. Variation has occurred. Therefore, depending on the bonded body, the bonding force between the substrates is weak, and both the substrates may be easily peeled off.
In particular, when microchips are obtained by joining microchip substrates having flow channel grooves formed on at least one microchip substrate using ultraviolet rays, the bonding force is weak depending on the obtained microchips. It is also conceivable that a problem that the liquid passing through the micro flow channel leaks from the portion occurs.
Such a problem is remarkable when the joined body is stored in a high temperature and high humidity environment.

Thus, the inventors of the present invention have made extensive studies on a method of joining two substrates using ultraviolet rays. As a result, the cause of the problem of obtaining a bonded body with insufficient bonding force as described above is not necessarily clear, but for example, it was considered that the following may be the cause.
This will be described with reference to FIGS. 10 and 11.

In the method of bonding two substrates using ultraviolet rays, first, as shown in FIG. 10A, the bonding surfaces of two substrates 31, 32 (for example, a COP (Cyclo-Olefin Polymer) substrate). 31A and 32A are irradiated with ultraviolet light L (for example, vacuum ultraviolet light having a wavelength of 172 nm) in an atmosphere containing oxygen (for example, in the air).
In this way, the bonding surfaces 31A and 32A of the

substrates

31 and 32 irradiated with the ultraviolet light L are activated. Specifically, the following states (1) to (3) are obtained. That is, the bonding surfaces 31A and 32A of the

substrates

31 and 32 are in a state where a chemical reaction is likely to occur.

(1) Organic substances adhering to the joint surfaces 31A and 32A are decomposed and removed.
(2) The polymer main chain is cut at the bonding surfaces 31A and 32A to generate radicals.
(3) Functional groups having high reactivity (specifically, functional groups containing oxygen atoms) are generated on the bonding surfaces 31A and 32A.

When the

substrates

31 and 32 are COP substrates, as shown in FIG. 10B, the bonding surfaces 31A and 32A of the

substrates

31 and 32 have a hydroxy group (—OH), a carboxy group (—COOH). ) And an aldehyde group (—CHO).

Next, as shown in FIG. 10C, both the substrates are laminated so that the activated bonding surfaces 31A and 32A of the

substrates

31 and 32 are in close contact with each other.
By appropriately pressing and heating the

substrates

31 and 32 thus laminated, a dehydration condensation reaction occurs in the region where the bonding surfaces 31A and 32B are in contact with each other as shown in FIG. A covalent bond of (O) is generated, and both workpieces are firmly joined by the covalent bond of oxygen. In the course of the dehydration condensation reaction, water (H ₂ O) and carbon dioxide (C ₂ O) are generated as shown in FIG.

Thus, as shown in FIG. 11, in the obtained bonded body, functional groups that did not contribute to the dehydration condensation reaction (hydroxy group and carboxy group are shown in FIG. 11) at the bonding interface. ), And the functional group may form a boundary layer that is easily affected by moisture, specifically, easily penetrated by moisture. Depending on the humidity conditions, this boundary layer has an increased amount of moisture (H ₂ O) penetration, and the amount of moisture present in the boundary layer increases, resulting in a decrease in bonding strength (adhesion), It is considered that both bonded substrates easily peel off.

In addition, since the boundary layer described above is not formed with good reproducibility, the irradiance of ultraviolet rays applied to the bonding surfaces 31A and 32A of the

substrates

31 and 32, and the added value when bonding the

substrates

31 and 32 to each other. Even if the conditions such as the pressure and pressure, the heating temperature, and the heating time are managed with high accuracy, it is considered that the joining state of the obtained joined body has varied.

For example, as shown in FIG. 12, the microchip 40 is provided with an inlet 43A for injecting a sample and an outlet 44A for discharging the sample on the surface (the upper surface in FIG. 12). A minute channel R communicating with the inlet 43A and the outlet 44A is provided inside. The microchip 40 includes a first microchip substrate 41 formed with an inlet through hole 43, an outlet through hole 44, and a flow channel 42 communicating with these through holes, and a flat plate-like second hole. This is obtained by bonding the microchip substrate 46.

In such a microchip 40, when the boundary layer described above is formed in the joint portion 48 (joint interface) between the first microchip substrate 41 and the second microchip substrate 46, FIG. (a), the water W present in the gas constituting the atmosphere surrounding environmental atmosphere and fine channel R (H 2 _O molecules), as well as water constituting the liquid flowing through the fine channel R are, As shown in FIG. 13B, it penetrates into the boundary layer. In some cases, as shown in FIG. 13C, the microchip 40 may be separated into the first microchip substrate 41 and the second microchip substrate 46.

Further, in the method of bonding two substrates using ultraviolet rays, swells are generated on each substrate, or minute irregularities exist on the substrate surface (bonding surface). It is not easy to bond a single substrate with high uniformity. Thus, a minute gap is formed at the bonding interface between the two substrates, and moisture easily enters the gap. Therefore, there is a possibility that two substrates may be peeled off due to moisture entering the bonding interface. Such a fear is remarkable when the laminated body of two board | substrates is pressurized and heated when joining board | substrates.

The present invention has been made in view of the circumstances as described above, and the object thereof is to achieve a high-strength bonding state at a bonding portion of two substrates and maintain the bonded state for a long period of time. It is to provide a possible microchip.

In the microchip of the present invention, the first microchip substrate and the second microchip substrate are joined, and the first microchip substrate communicates with the inlet and the outlet provided on the surface of the first microchip substrate. In a microchip having a flow path formed by a flow path groove formed in at least one of the first microchip substrate and the second microchip substrate,
Between the first microchip substrate and the second microchip substrate, an inner joint formed along the flow path, the first microchip substrate, and the second microchip substrate. And an outer joint formed along each outer peripheral edge of each of the first and second outer joints, and a sealed space is formed between the inner joint and the outer joint so as to surround the flow path. It is characterized by being.

In the microchip of the present invention, it is preferable that the sealed space is filled with a hygroscopic agent.

In the microchip of the present invention, it is preferable that the sealed space is in a reduced pressure state.
In the microchip of the present invention having such a configuration, the pressure in the sealed space is preferably 50 kPa or less.

In the microchip of the present invention, it is preferable that the sealed space is filled with a dry inert gas.
In the microchip of the present invention having such a configuration, the pressure in the sealed space may be 0.1 MPa to 0.5 MPa, and more preferably 0.1 MPa to 0.2 MPa.

In the microchip according to the present invention, a sealed space is provided between the first microchip substrate and the second microchip substrate so as to surround the flow channel together with the flow channel. It joins by the junction part and the outside junction part. Therefore, when the outer dimension of the microchip is constant, the bonding area can be controlled by the size of the sealed space. When bonding both substrates using ultraviolet rays, the substrates are laminated and then pressed, or pressurized and heated. Here, when the entire surface of both substrates is a bonding region, the entire surface of both substrates is pressurized. However, when the bonding area is appropriately set and pressurized as described above, the bonding area is controlled. In addition, it is possible to bond to the bonding surface with a higher pressure distribution uniformity than in the case where the entire surfaces of both substrates are pressurized, and thus suppress the formation of minute gaps at the bonding interface (inner bonding portion and outer bonding portion). It becomes possible to form a sealed space.
Moreover, in the sealed space, filling the moisture absorbing agent, making the pressure reduced, filling the dry inert gas, providing the moisture adsorption function or the moisture blocking function to form the moisture control space, the bonding interface. Even when a boundary layer in which moisture easily permeates is formed in the (inner joint portion and outer joint portion), an increase in the amount of moisture in the boundary layer can be suppressed by the action of the moisture control space.
Therefore, according to the microchip of the present invention, the occurrence of peeling between the two substrates due to the increased amount of moisture at the joint between the first microchip substrate and the second microchip substrate. Since it can suppress, the joining state of a high intensity | strength is obtained in the junction part of two board | substrates, and it becomes possible to maintain a bonding state over a long period of time.
Moreover, in the microchip of the present invention, since the sealed space is provided so as to surround the flow path, a heat retaining effect and a heat insulating effect can be obtained by the action of the sealed space.

It is explanatory drawing which shows the state which looked at the example of the structure of the microchip of this invention from the 1st microchip board | substrate side. FIG. 2 is a cross-sectional view showing a cross section taken along line AA of FIG. In the microchip of this invention, it is explanatory drawing which shows the state which a water | moisture content osmose | permeates a junction part. It is explanatory drawing which shows the state by which the water | moisture-content adsorption | suction function was provided to the sealed space in the microchip of this invention. It is explanatory drawing which shows the state by which the water | moisture-content block function was provided to the sealed space in the microchip of this invention. It is explanatory drawing which shows an example of the manufacturing process of the method of manufacturing the microchip of this invention. It is explanatory drawing which shows the other example of the manufacturing process of the method of manufacturing the microchip of this invention. It is explanatory drawing which shows the further another example of the manufacturing process of the method of manufacturing the microchip of this invention. It is explanatory drawing which shows the other example of a structure of the microchip of this invention. It is explanatory drawing which shows the process in the method of joining two board | substrates using an ultraviolet-ray. It is explanatory drawing which shows typically the joining interface of two board | substrates in the microchip obtained by passing through the process shown in FIG. It is explanatory drawing which shows an example of a structure of the conventional microchip. It is explanatory drawing which shows the process in which peeling arises between two board | substrates in the conventional microchip.

Embodiments of the present invention will be described below.
FIG. 1 is an explanatory view showing an example of the configuration of the microchip of the present invention as viewed from the first microchip substrate side. 2 is a cross-sectional view showing a cross section taken along line AA of FIG.
The microchip 10 has a substantially flat plate shape in which a first microchip substrate 11 and a second microchip substrate 16 are joined in a stacked state in the thickness direction. One surface (the upper surface in FIG. 2) is the surface of the microchip 10. Inside the microchip 10, a micro flow path R is formed that includes a flow path groove 12 formed on the bonding surface (the lower surface in FIG. 2) of the first microchip substrate 11. That is, a minute flow path R extending in the surface direction of the first microchip substrate 11 and the second microchip substrate 16 is formed between the first microchip substrate 11 and the second microchip substrate 16. ing. The minute channel R communicates with an inlet 13A provided on one surface of the first microchip substrate 11 (the surface of the microchip 10) at one end, and communicates with the surface of the first microchip substrate 11 at the other end. It communicates with the provided outlet 14A.
The first microchip substrate 11 and the second microchip substrate 16 are plate-like bodies made of a light transmissive material. Examples of the light transmissive material constituting the first microchip substrate 11 and the second microchip substrate 16 include a light transmissive plastic material such as an acrylic resin such as COP or polymethyl methacrylate (PMMA). And glass materials such as quartz glass. The first microchip substrate 11 and the second microchip substrate 16 may be made of the same constituent material, or may be made of different constituent materials.
In the example of this figure, both the first microchip substrate 11 and the second microchip substrate 16 are made of COP. The first microchip substrate 11 is formed with a channel groove 12 having a rectangular cross section that extends in a straight line at the center portion of the bonding surface, and has a cylindrical shape that communicates with the channel groove 12. It has a substantially rectangular flat plate shape in which an inlet through hole 13 and a cylindrical outlet through hole 14 are formed. The second microchip substrate 16 has a rectangular flat plate shape having a bonding surface (upper surface in FIG. 2) having the same vertical and horizontal dimensions as the bonding surface of the first microchip substrate 11. Then, the flow channel 12 formed in the first microchip substrate 11 is closed by the second microchip substrate 16 to form the micro flow channel R.

Further, in the microchip 10, an annular sealed space S is formed inside the microchip 10 so as to surround the minute flow path R. The sealed space S is formed between the first microchip substrate 11 and the second microchip substrate 16, and has an annular inner joint portion 21 extending along the microchannel R and the outer periphery of the microchip 10. It is located between the annular outer joint 26 extending along the surface 10A. The outer bonding portion 26 is formed by bonding the outer peripheral edge portions of the bonding surfaces of the first microchip substrate 11 and the second and microchip substrates 16. The sealed space S is separated from the minute flow path R by the inner barrier portion 22.
In the example of this figure, a rectangular annular sealed space recess 15 is formed on the bonding surface of the first microchip substrate 11 so as to surround the flow channel groove 12, and this sealed space recess 15. Is closed by the second microchip substrate 16 to form a sealed space S. The inner barrier portion 22 that separates the microchannel R and the sealed space S is an inner bank formed between the channel groove 12 and the sealed space recess 15 in the joint surface of the first microchip substrate 11. It is composed of parts. And the inner side junction part 21 is formed by joining the inner bank part and the joining surface of the 2nd microchip board | substrate 16. FIG. In addition, an outer bank portion is formed on the outer side of the recessed portion 15 for the sealed space, that is, the outer peripheral edge portion, on the bonding surface of the first microchip substrate 11, and the outer bank portion and the second microchip are formed. The outer bonding portion 26 is formed by bonding the bonding surface of the substrate 16 (specifically, the outer peripheral edge portion of the bonding surface of the second microchip substrate 16). And the outer side barrier part 27 is comprised by the outer side bank part.
In FIG. 2, the inner joint portion 21 and the outer joint portion 26 are surrounded by a broken line.

The volume of the sealed space S depends on the bonding area required in the microchip 10 (specifically, the total area of the bonding area related to the inner bonding portion 21 and the bonding area related to the outer bonding portion 26). These are determined appropriately in consideration of the constituent materials of the microchip substrate 11 and the second microchip substrate 16.

In the microchip 10, the bonding area is the area of the bonding surface (specifically, the area of the bonding surfaces of the first microchip substrate 11 and the second microchip substrate 16 from the viewpoint of bonding properties (bonding strength). ) Is preferably 10% or more, more preferably 10 to 40%.
When the bonding area is less than 10% of the area of the bonding surface, the bonding property may not necessarily be good. Further, when the bonding area exceeds 40% of the area of the bonding surface, the volume of the sealed space S becomes relatively small, and as a result, the moisture control function may be insufficient.

The thickness (width dimension) of the inner barrier portion 22, that is, the separation distance between the micro flow path R and the sealed space S is preferably at least 0.5 mm or more.
When the thickness of the inner barrier portion 22 is too small, fine processing in a mold for forming a microchip substrate is required, resulting in an increase in manufacturing cost. In addition, it is necessary to perform precise edge processing in the mold. If precise end processing is neglected, there arises a problem that a microchip substrate including a shape that becomes an obstructive factor for bonding, such as sink marks and burrs, is formed. In addition, since the bonding area becomes small, the mechanical strength (bonding strength) of the manufactured microchip is reduced depending on the bonding, and when the formed channel is used as the microchannel R of the microchip, The inner barrier portion is broken by an external force generated by an injection pressure or the like of the flowing fluid. Therefore, there may be a problem in quality as a microchip.
In the example of this figure, the thickness of the inner barrier portion 22 is 0.5 mm.

Further, the thickness (width dimension) of the outer barrier portion 27 is preferably 0.5 mm or more, similarly to the thickness of the inner barrier portion 22.
When the thickness of the outer barrier portion 27 is too small, the bonding area becomes very small. Therefore, as in the case of the inner barrier portion 26, the mechanical strength (bonding strength) of the microchip manufactured by bonding is small. In addition to the reduction, there is a risk that the quality of the microchip may be problematic, such as no more room for resistance to breakage of the outer barrier portion.
In the example of this figure, the thickness of the outer barrier portion 27 is 0.5 mm.

The sealed space S includes moisture (H ₂ O molecules) present in the gas constituting the ambient atmosphere of the microchip 10 and the atmosphere of the microchannel R, and the microchannel in the inner joint portion 21 and the outer joint portion 26. It is used as a moisture control space for suppressing an increase in the amount of moisture due to the penetration of moisture constituting the liquid flowing through R. This moisture control space has a moisture adsorption function or a moisture blocking function.

By making the sealed space S a moisture control space, the amount of moisture in the inner joint portion 21 and the outer joint portion 26 is increased, resulting in a space between the first microchip substrate 11 and the second microchip substrate 16. Generation | occurrence | production of peeling can be suppressed.
More specifically, when the microchip 10 is bonded through a process of closely contacting the bonding surfaces of the first microchip substrate 11 and the second microchip substrate 16 irradiated with ultraviolet rays, A boundary layer may be formed at the bonding interface (specifically, the inner bonding portion 21 and the outer bonding portion 26). The boundary layer includes a part of functional groups (specifically, hydroxy group (—OH), carboxy group (—COOH), aldehyde group (—CHO), etc.) present on the activated bonding surface. , Which is formed due to dehydration condensation reaction, that is, it does not contribute to the formation of covalent bonds of oxygen and remains at the bonding interface, and is susceptible to moisture, specifically, moisture easily penetrates It is. However, if the sealed space S is a moisture control space, an increase in the amount of moisture in the boundary layer can be suppressed by the moisture adsorption function or the moisture blocking function, so that the amount of moisture in the boundary layer increases. The occurrence of peeling between the first microchip substrate 11 and the second microchip substrate 16 can be suppressed.

The moisture adsorption function in the moisture control space is a function of adsorbing moisture that has penetrated into the inner joint portion 21 and moisture that has penetrated into the outer joint portion 26.
Thus, when the moisture control space has a moisture adsorption function, moisture that has penetrated into the inner joint portion 21 and the outer joint portion 26 is adsorbed to the moisture control space. Specifically, as shown in FIG. 3, in the microchip 10, when moisture W present in the gas constituting the ambient atmosphere of the microchip 10 penetrates the outer joint portion 26 (boundary layer). In some cases, moisture W present in the gas constituting the atmosphere of the minute flow path R and moisture constituting the liquid flowing through the minute flow path R permeate the inner joint portion 21 (boundary layer). In such a case, according to the moisture control space having a moisture adsorption function, as shown in FIG. 4, moisture W that has penetrated into the inner joint portion 21 and the outer joint portion 26 is adsorbed to the moisture control space. . Therefore, it is possible to reduce the moisture content of the inner joint portion 21 and the outer joint portion 26, that is, the remaining permeated moisture amount.

As a technique for providing a moisture adsorption function to the sealed space S and using the sealed space S as a moisture control space, for example, a technique of filling the sealed space S with a hygroscopic agent, That is, there is a method of reducing the pressure (vacuum atmosphere).

In the method of filling the sealed space S with a hygroscopic agent, various desiccants can be used as the hygroscopic agent. Specific examples of the desiccant include silica gel. Further, the shape of the desiccant may be a powdery body, a fiber body, a film body, and other shapes, and the desiccant may be filled in a state of being contained in the coating film in the sealed space S. Good.

In the method of bringing the sealed space S into a reduced pressure state, the atmospheric pressure in the reduced pressure atmosphere is preferably 50 kPa or less.
According to the experiments by the present inventors, by setting the pressure in the sealed space S in a reduced pressure state to 50 kPa or less, the moisture adsorption function of moisture that has permeated the inner joint portion 21 and the outer joint portion 26 is sufficiently set in the sealed space S. It was found that separation between microchip substrates due to moisture can be sufficiently reduced.

In addition, the moisture blocking function in the moisture control space refers to the moisture (H ₂ O) present in the gas constituting the ambient environment atmosphere of the microchip 10 and the atmosphere of the microchannel R at the inner joint portion 21 and the outer joint portion 26. Molecule), and a function of suppressing the penetration of moisture constituting the liquid flowing through the microchannel R.
Thus, when the moisture control space has a moisture blocking function, as shown in FIG. 5, the moisture W or the minute channel present in the gas constituting the atmosphere of the minute channel R at the inner joint portion 21. It is possible to prevent or sufficiently suppress the penetration of moisture W constituting the liquid flowing through R. In addition, it is possible to prevent or sufficiently suppress the penetration of moisture W present in the gas constituting the ambient environment atmosphere of the microchip 10 in the outer joint portion 26.

As a method for providing the sealed space S with a moisture blocking function and using the sealed space S as a moisture control space, for example, the sealed space S is filled with a dry inert gas having a remarkably low moisture content. Specifically, a method in which the dry inert gas is sealed in the sealed space S at an atmospheric pressure or a pressure higher than the atmospheric pressure (positive pressure) can be mentioned.

In the method of sealing the dry inert gas in the sealed space S at atmospheric pressure or positive pressure, nitrogen gas is an example of the inert gas constituting the dry inert gas.
The water content in the dry inert gas is preferably a dew point temperature of −40 ° C. or lower.

In the method of sealing the dry inert gas in the sealed space S at atmospheric pressure or positive pressure, the pressure in the sealed space S in which the dry inert gas is sealed may be 0.1 MPa to 0.5 MPa, More preferably, it is -0.2 MPa.
If the pressure in the sealed space S filled with the dry inert gas is too low, the moisture blocking function may be lowered.
On the other hand, when the pressure in the sealed space S filled with the dry inert gas is excessive, the bonding force between the microchip substrates may be weakened.

The microchip 10 having such a configuration can be manufactured by an appropriate method according to the function to be imparted to the sealed space S.
Hereinafter, a specific example of the manufacturing method of the microchip 10 will be described with reference to the drawings.
In the following, the first manufacturing method is a method of manufacturing the microchip 10 that uses the sealed space S as a moisture control space having a moisture adsorption function by filling a hygroscopic agent. The second manufacturing method is a method of manufacturing the microchip 10 that is used as a moisture control space having a moisture adsorption function by making the sealed space S into a reduced pressure state. Further, the third manufacturing method manufactures the microchip 10 using the sealed space S as a moisture control space having a moisture blocking function by enclosing the dry inert gas in the sealed space S at atmospheric pressure or positive pressure. It is a method to do.

[First production method]
First, as shown in FIG. 6, a first microchip substrate 11 made of, for example, COP, a second microchip substrate 16 made of, for example, COP, and a hygroscopic agent 29 made of, for example, silica gel are prepared. The first microchip substrate 11 has a channel groove 12 and a sealed space recess 15 formed on a bonding surface (upper surface in FIGS. 6A, 6B, and 6D). It has a substantially rectangular flat plate shape in which the inlet through hole 13 and the outlet through hole 14 are formed. Further, the second microchip substrate 16 has a joint surface (an upper surface in FIG. 6C and a lower surface in FIG. 6D) having the same vertical and horizontal dimensions as the joint surface of the first microchip substrate 11. It is a rectangular flat plate.

(Hygroscopic agent filling process)
In the hygroscopic agent filling step, as shown in FIG. 6A, the hygroscopic agent 29 is filled in the sealed space recess 15 in the first microchip substrate 11.
In this hygroscopic agent filling step, as a specific method for filling the recessed space 15 with the hygroscopic agent 29, for example, a powdery desiccant powder is dispersed in ethanol, and this dispersion is used for tweezers, brushes, dispensers The method of filling the recessed space 15 with the hygroscopic agent 29 by applying ethanol on the surface of the sealed space recess 15 and drying and removing ethanol as a solvent in the drying process after the coating process. It is done.

(UV irradiation process)
In the ultraviolet irradiation process, as shown in FIG. 6B and FIG. 6C, the bonding surface of the first microchip substrate 11 and the bonding surface of the second microchip substrate 16 that have undergone the hygroscopic agent filling step. Each is irradiated with vacuum ultraviolet rays L1 and L2 having a wavelength of 200 nm or less in an oxygen-containing atmosphere (for example, in the air).
Through this ultraviolet irradiation process, the bonding surface of the first microchip substrate 11 and the bonding surface of the second microchip substrate 16 irradiated with the vacuum ultraviolet rays L1 and L2 are activated. Specifically, organic substances adhering to the bonding surface are decomposed and removed, radicals are generated on the bonding surface, and highly reactive functional groups (specifically, functional groups containing oxygen atoms). Is generated. Here, when the first microchip substrate 11 and the second microchip substrate 16 are made of COP, the bonding surface of the first microchip substrate 11 and the bonding surface of the second microchip substrate 16 are ultraviolet rays. Through the irradiation step, functional groups such as a hydroxy group (—OH), a carboxy group (—COOH), and an aldehyde group (—CHO) are bonded.

In the ultraviolet irradiation step, an excimer lamp such as a xenon excimer lamp that emits a vacuum ultraviolet ray having a central wavelength at a wavelength of 172 nm can be suitably used as a light source that emits the vacuum ultraviolet rays L1 and L2.
The irradiance of the vacuum ultraviolet rays L1 and L2 applied to each of the bonding surface of the first microchip substrate 11 and the bonding surface of the second microchip substrate 16 is, for example, 10 to 100 mW / cm ² , particularly 40 mW / cm ^2. cm ² is preferred.
In addition, the irradiation time of the vacuum ultraviolet rays L1 and L2 on each of the bonding surface of the first microchip substrate 11 and the bonding surface of the second microchip 16 is determined by the first microchip substrate 11 and the second macrochip substrate 16. Depending on the constituent materials and the state of the bonding surfaces of the first microchip substrate 11 and the second microchip substrate 16, the type of the hygroscopic agent 29 is appropriately set. In particular, 60 seconds is preferable.

(Joining process)
In the bonding step, as shown in FIG. 6D, the first microchip substrate 11 and the second microchip substrate 16 that have undergone the ultraviolet irradiation step are brought into a state in which their respective bonding surfaces are in close contact with each other. Laminate. Thereafter, the laminated body of the first microchip substrate 11 and the second microchip substrate 16 is pressurized or heated. Or the laminated body of the 1st microchip board | substrate 11 and the 2nd microchip board | substrate 16 is heated, pressing.
Through this bonding step, a dehydration condensation reaction occurs in the region where the bonding surfaces of the first microchip substrate 11 and the second microchip substrate 16 are in contact with each other, that is, the bonding interface, so that oxygen (O) is covalently bonded. And the microchip substrates are firmly bonded to each other by the covalent bond of oxygen. As a result, the microchip 10 in which the first microchip substrate 11 and the second microchip substrate 16 are joined and the sealed space S is made into a moisture control space having a moisture adsorption function by filling the moisture absorbent 29 is obtained. can get.

In the bonding step, the pressurizing condition and heating condition are appropriately set in consideration of the type of the moisture absorbent 29 according to the constituent material of the first microchip substrate 11 and the constituent material of the second microchip substrate 16. Further, the pressurizing time and the heating time are set to a predetermined time according to the pressurizing condition and the heating condition. Here, the predetermined time is basically the time required for the dehydration condensation reaction to proceed at the bonding interface between the two microchip substrates and sufficient bonding between the two microchip substrates.

In the bonding step, when the laminate of the first microchip substrate 11 and the second microchip substrate 16 is pressurized, the laminate is pressurized for a predetermined time as necessary, and then further predetermined. You may heat for hours. Specifically, the pressurization state of the laminate is maintained for a predetermined time, and thereafter, the pressurization state is released, the temperature of the laminate is increased to a predetermined temperature, and the desired bonding state is obtained. You may make it maintain until it is done. Here, the predetermined temperature is a temperature at which the laminated body (the first microchip substrate 11 and the second microchip substrate 16) is not deformed.
According to heating after pressurizing the laminated body, a part where a sufficient bonding state is obtained and a part where a sufficient bonding state is not obtained are mixed in the bonding interface in the laminated body after pressing. Even if it is the case where it is doing, the joining state can be made into an intended state in the part in which sufficient joining state was not obtained by heating.

Moreover, it is preferable to perform a joining process within 10 minutes after an ultraviolet irradiation process is completed.
When the time from the completion of the ultraviolet irradiation process to the start of the bonding process exceeds 10 minutes, moisture (on the bonding surface of the first microchip substrate 11 and the bonding surface of the second microchip substrate 16) There is a risk that excess water) and impurities will re-adhere. Therefore, in the obtained microchip 10, it may be difficult to reliably achieve a high-strength bonding state between the first microchip substrate 11 and the second microchip substrate 16.

[Second production method]
First, as shown in FIG. 7, a first microchip substrate 11 made of, for example, COP and a second microchip substrate 16 made of, for example, COP are prepared. The first microchip substrate 11 has a channel groove 12 and a sealed space recess 15 formed in the joint surface (the upper surface in FIGS. 7A and 7C), and the inlet through-hole 13 and It has a substantially rectangular flat plate shape in which the discharge port through hole 14 is formed. Further, the second microchip substrate 16 has a bonding surface (the upper surface in FIG. 7B and the lower surface in FIG. 7C) having the same vertical and horizontal dimensions as the bonding surface of the first microchip substrate 11. It is a rectangular flat plate.

(UV irradiation process)
In the ultraviolet irradiation process, as shown in FIGS. 7A and 7B, oxygen is applied to each of the bonding surface of the first microchip substrate 11 and the bonding surface of the second microchip substrate 16. In an atmosphere including the atmosphere (for example, in the atmosphere), vacuum ultraviolet rays L1 and L2 having a wavelength of 200 nm or less are irradiated.
Through this ultraviolet irradiation process, the bonding surface of the first microchip substrate 11 and the bonding surface of the second microchip substrate 16 irradiated with the vacuum ultraviolet rays L1 and L2 are activated. Specifically, organic substances adhering to the bonding surface are decomposed and removed, radicals are generated on the bonding surface, and highly reactive functional groups (specifically, functional groups containing oxygen atoms). Is generated.

In the ultraviolet irradiation step, an excimer lamp such as a xenon excimer lamp that emits a vacuum ultraviolet ray having a central wavelength at a wavelength of 172 nm can be suitably used as a light source that emits the vacuum ultraviolet rays L1 and L2.
The irradiance of the vacuum ultraviolet rays L1 and L2 applied to each of the bonding surface of the first microchip substrate 11 and the bonding surface of the second microchip substrate 16 is, for example, 10 to 100 mW / cm ² , particularly 40 mW / cm ^2. cm ² is preferred.
In addition, the irradiation time of the vacuum ultraviolet rays L1 and L2 on each of the bonding surface of the first microchip substrate 11 and the bonding surface of the second microchip 16 is determined by the first microchip substrate 11 and the second macrochip substrate 16. Depending on the constituent materials and the state of the bonding surfaces of the first microchip substrate 11 and the second microchip substrate 16, etc., it is appropriately set. For example, it is 5 to 120 seconds, and particularly preferably 60 seconds.

(Joining process)
In the bonding step, first, the atmosphere in which the first microchip substrate 11 and the second microchip substrate 16 that have undergone the ultraviolet irradiation step exist, that is, the bonding between the first microchip substrate 11 and the second microchip 16. The atmosphere in which is performed is a reduced pressure atmosphere (vacuum atmosphere). Next, as shown in FIG. 7C, the first microchip substrate 11 and the second microchip substrate 16 are laminated so that their bonding surfaces are in close contact with each other. Thereafter, the laminated body of the first microchip substrate 11 and the second microchip substrate 16 is pressurized or heated. Or the laminated body of the 1st microchip board | substrate 11 and the 2nd microchip board | substrate 16 is heated, pressing.
Through this bonding step, a dehydration condensation reaction occurs in the region where the bonding surfaces of the first microchip substrate 11 and the second microchip substrate 16 are in contact with each other, that is, the bonding interface, so that oxygen (O) is covalently bonded. And the microchip substrates are firmly bonded to each other by the covalent bond of oxygen. As a result, the first microchip substrate 11 and the second microchip substrate 16 are joined, and the sealed space S is made into a moisture control space having a moisture adsorption function by being in a reduced pressure state. Is obtained.

In the bonding step, the atmospheric pressure of the atmosphere for performing the bonding (reduced pressure atmosphere) is set to 50 kPa or less.
When the atmospheric pressure of the reduced-pressure atmosphere is excessive, there is a possibility that the desired moisture adsorption function cannot be imparted to the sealed space S in the obtained microchip 10.

In the bonding process, the pressurizing condition and heating condition are appropriately set according to the constituent material of the first microchip substrate 11 and the constituent material of the second microchip substrate 16. Further, the pressurizing time and the heating time are set to a predetermined time according to the pressurizing condition and the heating condition.

[Third production method]
First, as shown in FIG. 8, a first microchip substrate 11 made of COP, for example, and a second microchip substrate 16 made of COP, for example, are prepared. The first microchip substrate 11 has a channel groove 12 and a sealed space recess 15 formed in the bonding surface (upper surface in FIGS. 8A and 8C), and the inlet through-hole 13 and It has a substantially rectangular flat plate shape in which the discharge port through hole 14 is formed. The second microchip substrate 16 has a bonding surface (the upper surface in FIG. 8B and the lower surface in FIG. 8C) having the same vertical and horizontal dimensions as the bonding surface of the first microchip substrate 11. It is a rectangular flat plate.

(UV irradiation process)
In the ultraviolet irradiation process, as shown in FIGS. 8A and 8B, oxygen is applied to each of the bonding surface of the first microchip substrate 11 and the bonding surface of the second microchip substrate 16. In the atmosphere (in the atmosphere) containing, vacuum ultraviolet rays L1 and L2 having a wavelength of 200 nm or less are irradiated.
Through this ultraviolet irradiation process, the bonding surface of the first microchip substrate 11 and the bonding surface of the second microchip substrate 16 irradiated with the vacuum ultraviolet rays L1 and L2 are activated. Specifically, organic substances adhering to the bonding surface are decomposed and removed, radicals are generated on the bonding surface, and highly reactive functional groups (specifically, functional groups containing oxygen atoms). Is generated.

(Joining process)
In the bonding step, first, the atmosphere in which the first microchip substrate 11 and the second microchip substrate 16 that have undergone the ultraviolet irradiation step exist, that is, the bonding between the first microchip substrate 11 and the second microchip 16. The atmosphere to perform is a dry inert gas atmosphere made of a dry inert gas having a remarkably low water content. Next, as shown in FIG. 8C, the first microchip substrate 11 and the second microchip substrate 16 are laminated so that their bonding surfaces are in close contact with each other. Thereafter, the laminated body of the first microchip substrate 11 and the second microchip substrate 16 is pressurized or heated. Or the laminated body of the 1st microchip board | substrate 11 and the 2nd microchip board | substrate 16 is heated, pressing.
Through this bonding step, a dehydration condensation reaction occurs in the region where the bonding surfaces of the first microchip substrate 11 and the second microchip substrate 16 are in contact with each other, that is, the bonding interface, so that oxygen (O) is covalently bonded. And the microchip substrates are firmly bonded to each other by the covalent bond of oxygen. As a result, the first microchip substrate 11 and the second microchip substrate 16 are joined, and the sealed space S is made into a moisture control space having a moisture blocking function by being filled with a dry inert gas. A microchip 10 is obtained.

In the joining step, a gas having a moisture content of −40 ° C. or lower is suitably used as the dry inert gas. Specific examples of the inert gas constituting the dry inert gas include, for example, nitrogen gas.

In addition, the atmospheric pressure of the atmosphere in which the bonding is performed (dry inert gas atmosphere) is set to atmospheric pressure or a pressure higher than atmospheric pressure (positive pressure), specifically, 0.1 MPa to 0.5 MPa may be sufficient. More preferably, the pressure is 0.1 MPa to 0.2 MPa.
When the atmospheric pressure of the dry inert gas atmosphere is out of the above range, in the obtained microchip 10, it is impossible to give the desired moisture blocking function to the sealed space S, or between the microchip substrates. There is a possibility that the bonding force of the is weakened.

In the bonding step, when the laminate of the first microchip substrate 11 and the second microchip substrate 16 is pressurized, the laminate is pressurized for a predetermined time as necessary, and then further predetermined. You may heat for hours. Specifically, the pressurized state is maintained for a predetermined time with respect to the laminated body, and then the pressurized state is released, and the temperature of the laminated body is increased to a predetermined temperature. It may be maintained until it is obtained. Here, the predetermined temperature is a temperature at which the laminated body (the first microchip substrate 11 and the second microchip substrate 16) is not deformed.
According to heating after pressurizing the laminated body, a part where a sufficient bonding state is obtained and a part where a sufficient bonding state is not obtained are mixed in the bonding interface in the laminated body after pressing. Even if it is the case where it is doing, the joining state can be made into an intended state in the part in which sufficient joining state was not obtained by heating.

In the microchip 10 described above, a sealed space S is provided between the first microchip substrate 11 and the second microchip substrate 16 so as to surround the microchannel R together with the microchannel R. Both substrates are joined by the inner joint 21 and the outer joint 26. Therefore, since the bonding area can be controlled by the size of the sealed space S, both substrates can be bonded with high uniformity by bonding both substrates using ultraviolet rays. That is, in the manufacturing process (bonding process) in which both substrates are stacked after ultraviolet irradiation, when the laminate of both substrates is pressed, it is added to the areas related to the inner bank portion and the outer bank portion at the time of pressing. Since pressure concentration can be generated, both substrates can be bonded with higher uniformity, and greater bonding strength can be obtained at the inner bonding portion 21 and the outer bonding portion 26. As a result, the formation of minute gaps at the inner joint 21 and the outer joint 26 (joint interface) is suppressed.
Moreover, by providing the sealed space S with a moisture adsorption function or a moisture blocking function to form a moisture control space, a boundary layer in which moisture easily penetrates into the bonding interface (the inner bonding portion 21 and the outer bonding portion 26) is formed. Even in this case, an increase in the amount of moisture in the boundary layer can be suppressed by the action of the moisture control space.
Therefore, according to the microchip 10, the separation between the first microchip substrate 11 and the second microchip substrate 16 due to the increased amount of water in the inner joint portion 21 and the outer joint portion 26. Since generation | occurrence | production of this can be suppressed, the joining state of high intensity | strength is obtained for the said inner side junction part 21 and the outer side junction part 26, and it becomes possible to maintain a bonding state over a long period of time.
Further, according to the microchip of the present invention, since the sealed space S is provided so as to surround the minute flow path R, the heat retaining effect and the heat insulating effect can be obtained by the action of the sealed space S.

In the microchip 10, the function (moisture adsorption function and moisture block function) of the sealed space S as the moisture control space is limited, and the function is obtained after a certain time (finite time) has elapsed. Disappear. However, since the microchip 10 is normally a disposable product and is disposable within a time shorter than the finite time, there is no practical problem.

Further, in the microchip 10, when the sealed space S is used as a moisture control space having a moisture adsorption function by bringing the sealed space S into a decompressed state, the first microchip substrate is brought about by the suction action of the sealed space S in the decompressed state. The occurrence of peeling between the first microchip substrate 11 and the second microchip substrate 16 is further suppressed. Although moisture easily enters the sealed space S through the inner joint portion 21 and the outer joint portion 26, the sealed space S enters through the moisture inner joint portion 21 and the outer joint portion 26 that has entered the sealed space S. Will not be discharged outside.

The microchip of the present invention is not limited to the above embodiment, and various modifications can be made.
For example, the second microchip substrate may be a film-like body made of a light transmissive material. In the film-like body constituting the second microchip substrate, the thickness is preferably small from the viewpoint of bondability (bonding strength) and moisture controllability (moisture adsorption function). For example, the thickness of the film-like body is 50 to 200 μm. In the microchip including the second microchip substrate having such a configuration, the sealed space is used as a moisture control space by being provided with a moisture adsorption function by a method of reducing the sealed space to a reduced pressure state. In this microchip, as shown in FIG. 9, the second microchip substrate 19 (film-like body) is formed in the sealed space recess 15 by the action of the difference between the pressure in the sealed space S and the ambient pressure in the surrounding environment. Is bent in the direction toward the bottom surface 15A, and the bonding surface of the second microchip substrate 19 is in contact with the bottom surface 15A. Therefore, the sealed space S extends in a ring shape along the wall surface formed by the inner barrier portion 22, and the cross section extends in a ring shape along the wall surface formed by the outer barrier portion 27. It will be comprised by this annular space. Here, the maximum separation distance between the inner barrier portion 22 or the outer barrier portion 27 and the second microchip substrate 19 is, for example, about 0.1 to 2 mm according to the thickness of the second microchip substrate 19. .
According to the microchip having such a configuration, moisture controllability (moisture adsorption function) can be obtained in the sealed space S, and even higher joint strength can be obtained in the inner joint portion 21 and the outer joint portion 26. it can.

Further, the micro flow path may be formed of a flow path groove formed on at least one of the first microchip substrate and the second microchip substrate. That is, the channel groove may be formed only on the second microchip substrate, or may be formed on both microchip substrates.

Hereinafter, specific examples of the present invention will be described, but the present invention is not limited thereto.

[Example 1]
(Microchip production example 1)
A microchip was fabricated based on the configuration shown in FIGS.
Specifically, first, a first microchip substrate, a second microchip substrate, and a hygroscopic agent were prepared.
Further, as the first microchip substrate, a channel groove, a through hole communicating with the channel groove (a through hole for an inlet and a through hole for a discharge port), and a concave for a sealed space are formed on one surface as a bonding surface. A substantially rectangular flat plate-shaped COP substrate (longitudinal dimension: 75.5 mm × horizontal dimension: 25.5 mm × thickness: 3 mm) was prepared. In the first microchip substrate, the channel groove has a rectangular cross section with a width of 800 μm, a length of 9000 μm, and a depth of 200 μm, and is formed at the center of the joint surface. The recess for the sealed space is a rectangular ring formed so as to surround the channel groove between the inner bank portion having a width of 1000 μm and the outer bank portion having a width of 1000 μm, and the cross-sectional shape thereof is rectangular. The shape is 50 μm deep.
In addition, as the second microchip substrate, a rectangular flat plate-shaped COP substrate (longitudinal dimension 75.5 mm × horizontal dimension 25.5 mm × thickness 1 mm) is prepared, and as the hygroscopic agent (desiccant), a powder form is prepared. Silica gel, that is, silica gel fine particles (average particle size 5.0 μm) were prepared.

Next, a silica gel dispersion liquid is prepared by dispersing silica gel fine particles in ethanol, and the silica gel dispersion liquid is applied to the recessed area for the sealed space of the first microchip substrate and dried to thereby form the recessed space for the sealed space. The place was filled with silica gel (a hygroscopic agent filling step).

Further, vacuum ultraviolet rays are applied to the bonding surface of the first microchip substrate that has undergone the hygroscopic agent filling step and the bonding surface of the second microchip substrate using an ultraviolet irradiation device in the atmosphere, respectively. Irradiation (ultraviolet irradiation process). The ultraviolet irradiation device used is configured to irradiate vacuum ultraviolet rays having a wavelength of 172 nm through a ultraviolet transmission window to a square irradiation area having a side of 300 mm. With respect to this ultraviolet irradiation device, when the window surface illuminance (irradiance) was confirmed using an ultraviolet illuminance meter “UIT-205 + VUV-S172” (manufactured by USHIO INC.), It was about 40 mW / cm ² . The irradiation time was 60 seconds. Further, when the vacuum ultraviolet irradiation is performed, the separation distance (irradiation distance) between the ultraviolet transmission window and the bonding surface (specifically, the bonding surface of the first microchip substrate and the second microchip substrate) in the ultraviolet irradiation apparatus is: In consideration of absorption of vacuum ultraviolet rays by atmospheric oxygen, the thickness is set to 3 mm. In addition, when the vacuum ultraviolet irradiation is performed, the processing atmosphere between the ultraviolet transmission window and the joint surface in the ultraviolet irradiation apparatus uses the intake air of the exhaust duct disposed on the back surface of the irradiation space related to the ultraviolet irradiation apparatus, and the ambient environment. It comprised by taking in the gas (air) which comprises atmosphere.

Then, the 1st microchip board | substrate and the 2nd microchip board | substrate were joined using the bonding apparatus by an ad tech engineering company.
More specifically, the first microchip substrate that has been subjected to the ultraviolet irradiation step and the second microchip substrate that has been subjected to the ultraviolet irradiation step have a bonding surface facing each other, and a size suitable for the sealed space therebetween. Of cobalt chloride paper (cobalt chloride (II) hexahydrate test paper). Cobalt chloride paper that had been dried in advance was used. Then, the obtained laminated body is placed on the pressure stage of the bonding apparatus, and in order to remove moisture from the two microchip substrates constituting the laminated body on the pressure stage, 200 is used. Preheating was performed under the following conditions for 2 seconds. At the same time, after evacuation was performed in the processing space of the bonding apparatus, the atmosphere of the processing space was appropriately adjusted. Then, the laminated body was pressurized with the bonding apparatus, heating for 300 seconds on the conditions of the applied pressure 3000N and the heating temperature of 130 degreeC.
In this way, the first microchip substrate and the second microchip substrate are joined, and the microchip (hereinafter also referred to as “microchip (1)”) in which cobalt chloride paper is disposed in the sealed space. .) In this microchip (1), a sealed space is filled with a hygroscopic agent so that the sealed space is a moisture control space having a moisture adsorption function.
The reason why cobalt chloride paper is provided in the sealed space is to evaluate the microchip as described below.

(Evaluation of microchip)
The prepared microchip (1) is placed in a constant temperature and humidity chamber and left to stand for two weeks at maximum in an environment of a temperature of 40 ° C. and a humidity of 95% RH. In addition, the distribution of the color reaction occurrence locations and the presence or absence of peeling were confirmed visually. The results are shown in Table 1.

[Example 2]
(Microchip production example 2)
In microchip production example 1 of Example 1, the hygroscopic agent filling process was not performed, and the bonding process was performed except that the atmosphere in the processing space of the bonding apparatus was changed to a vacuum atmosphere (atmospheric pressure 100 Pa). A microchip (hereinafter also referred to as “microchip (2)”) was produced in the same manner as in Microchip Production Example 1. In the microchip (2), the sealed space is made into a moisture control space having a moisture adsorption function by bringing the sealed space into a reduced pressure state (vacuum state with an atmospheric pressure of 100 Pa).

(Evaluation of microchip)
About the produced microchip (2), by the same method as Example 1, the presence or absence of the occurrence of a color reaction in the cobalt chloride paper, the distribution of the color reaction occurrence place, and the presence or absence of the occurrence of peeling were visually confirmed. did. The results are shown in Table 1.

Example 3
(Production example 3 of microchip)
In the microchip production example 2 of Example 2, in the bonding process, the atmosphere in the processing space of the bonding apparatus is a positive pressure atmosphere (atmospheric pressure) of dry nitrogen gas whose moisture content is −40 ° C. in terms of dew point temperature. A microchip (hereinafter also referred to as “microchip (3)”) was produced in the same manner as in Microchip Production Example 2 except that the pressure was 0.15 MPa. In this microchip (3), dry nitrogen gas is sealed in a sealed space at a positive pressure (atmospheric pressure 0.15 MPa), whereby the sealed space is made into a moisture control space having a moisture blocking function.

(Evaluation of microchip)
About the produced microchip (3), by the same method as Example 1, the presence or absence of the color reaction in the cobalt chloride paper, the distribution of the color reaction occurrence site, and the presence or absence of the peeling were visually confirmed. did. The results are shown in Table 1.

Example 4
(Microchip production example 4)
In microchip production example 2 of example 2, in place of the COP substrate, a COP film-like body having a thickness of 100 μm was used as the second microchip substrate. Similarly, a microchip (hereinafter also referred to as “microchip (4)”) was manufactured. In this microchip (4), the sealed space is made into a moisture control space having a moisture adsorption function by bringing the sealed space into a reduced pressure state (vacuum state with an atmospheric pressure of 100 Pa).

(Evaluation of microchip)
About the produced microchip (4), by the same method as Example 1, the presence or absence of the occurrence of the color reaction in the cobalt chloride paper, the distribution of the color reaction occurrence location, and the presence or absence of the occurrence of peeling were visually confirmed. did. The results are shown in Table 1.

As is apparent from Table 1, in any of the microchip (1), microchip (2), microchip (3), and microchip (4), the environmental conditions are a temperature of 40 ° C. and a humidity of 95% RH. Even when left for 2 weeks, no color reaction occurred in the cobalt chloride paper. Moreover, peeling was not confirmed.

10 Microchip 10A Outer peripheral surface 11 First microchip substrate 12 Channel groove 13 Inlet through hole 13A Inlet 14 Outlet through hole 14A Outlet 15 Sealed recess 15A Bottom surface 16 Second microchip substrate 19 Second microchip substrate 21 Inner bonding portion 22 Inner barrier portion 26 Outer bonding portion 27 Outer barrier portion 29 Hygroscopic agent 31 Substrate 31A Bonding surface 32 Substrate 32A Bonding surface 40 Microchip 41 First microchip substrate 42 Channel groove 43 Inlet through hole 43A Inlet 44 Outlet through hole 44A Outlet 46 Second microchip substrate 48 Joint R Micro flow path S Sealed space

Claims

The first microchip substrate and the second microchip substrate are joined to each other and communicated with the inlet and the outlet provided on the surface of the first microchip substrate. In a microchip having a flow path formed of flow path grooves formed in at least one of the two microchip substrates,
Between the first microchip substrate and the second microchip substrate, an inner joint formed along the flow path, the first microchip substrate, and the second microchip substrate. And an outer joint formed along each outer peripheral edge of each of the first and second outer joints, and a sealed space is formed between the inner joint and the outer joint so as to surround the flow path. A microchip characterized by
The microchip according to claim 1, wherein the sealed space is filled with a hygroscopic agent.
The microchip according to claim 1, wherein the sealed space is in a reduced pressure state.
The microchip according to claim 3, wherein the pressure in the sealed space is 50 kPa or less.
The microchip according to claim 1, wherein the sealed space is filled with a dry inert gas.
6. The microchip according to claim 5, wherein the pressure in the sealed space is 0.1 MPa to 0.2 MPa.