Micro flow channel chip

Abstract

To provide a micro flow channel chip capable of preventing infiltration (contamination) of liquid (analyte) from occurring between neighboring flow channels.SOLUTION: A micro flow channel chip includes: a substrate 10; a barrier wall layer 20 disposed on the substrate 10 and defining a flow channel 3; and a lid material 30 disposed on the face of the barrier wall layer 20 opposite to the face having contact with the substrate 10. The barrier wall layer 20 includes a float part 21 being a region on the lid material 30 side and having no contact with the lid material 30. When viewed in the thickness direction of the barrier wall layer 20, the ratio of the width (a sum of widths W2 and W3) of the float part 21 is 0% to 62% with regard to the width W1 of the barrier wall layer 20 interposed between flow channels 3.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present disclosure relates to a microchannel chip.

Background Art

[0002] In recent years, technologies have been proposed that apply lithography and thick-film process technologies to form a fine reaction field and enable inspections with samples in the range of several μL to several nL. Such a technology using such a fine reaction field is called μ-TAS (Micro Total Analysis System). μ-TAS is applied in areas such as gene testing, chromosome testing, cell testing, pharmaceutical development, as well as biotechnology, detection of trace substances in the environment, investigation of the breeding environment of crops, etc., and gene testing of crops. The introduction of μ-TAS technology can bring about great effects such as automation, high speed, high precision, low cost, rapidity, and reduction of environmental impact. In μ-TAS, in many cases, micro-meter-sized channels (microchannels, microchannels) formed on a substrate are used, and such a substrate is called a chip, a microchip, a microchannel chip, a microfluidic chip, a microfluidic device, a microchannel device, etc.

[0003] Conventionally, such microchannel chips have been manufactured using techniques such as injection molding, mold molding, cutting, and etching. Also, as the substrate of the microchannel chip, a glass substrate is mainly used because it is easy to manufacture and optical detection is also possible. On the other hand, the development of a microchannel chip using a resin material that is lightweight, less likely to break than a glass substrate, and inexpensive is also underway. As a manufacturing method of a microchannel chip using a resin material, there is a method of mainly forming a resin substrate having a channel pattern by photolithography and bonding a lid material thereto to manufacture a microchannel chip. According to this method, it is possible to form a fine channel pattern, which was difficult in the prior art.

[0004] In addition, as a method of bonding the substrate side (the wall portion provided on the substrate) of the microchannel chip and the lid material, a method of bonding with an adhesive having a thickness of several μm to several tens of μm (including adhesives, sealants, double-sided tapes, adhesive tapes, etc.) is relatively common (see, for example, Patent Document 1). However, when bonding using an adhesive, depending on the use of the microchannel chip, elution of the components of the adhesive and visibility in inspection may become problems. Therefore, without using an adhesive, pressure bonding using a hot press machine or an ultrasonic welding machine (see, for example, Patent Document 2), or a method of plasmaizing a process gas under atmospheric pressure or a pressure in the vicinity thereof and modifying both surfaces of the lid material and the wall portion to which the lid material is joined to perform bonding has also been proposed (see, for example, Patent Document 3).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0006] When manufacturing a microchannel chip, if a resin layer (wall portion) forming a channel pattern on a substrate and a lid material are bonded together without using an adhesive, there may occur a problem that minute gaps are formed at the interface (bonding surface) of the bonding region between the resin layer and the lid material. The cause of the formation of minute gaps is considered to be irregularities on the surface of the resin layer in the order of nanometers (nm) to micrometers (μm). That is, since minute irregularities serving as the basis of surface roughness and slight protrusions exist on the surface of the resin layer, when the lid material is bonded without using an adhesive, minute gaps caused by the above-mentioned irregularities and protrusions are formed at the above-mentioned interface (bonding surface) between the resin layer and the lid material. Although this minute gap depends on the manufacturing method of the channel, the type of material constituting the resin layer, and the bonding conditions between the lid material and the resin layer, it is impossible to completely prevent the occurrence of the gap. Incidentally, the minute gap at the interface (bonding surface) between this resin layer and the lid material is so small that it cannot be observed with a microscope.

[0007] When many minute gaps exist at the interface (bonding surface) between the resin layer and the lid material, or when even a small number of relatively large gaps exist, liquid penetrates into the gaps, and adjacent channels are unintentionally connected. For this reason, contamination of the fluid (specimen) may occur through the gaps, and there is a possibility that the functions required for the microchannel chip cannot be provided.

[0008] In addition, as one of the causes for adjacent channels to be unintentionally connected, there is the cross-sectional shape of the resin layer (partition layer) in which the channel pattern is formed. Various methods such as lithography, cutting, imprinting, and injection molding can be applied to form the channel pattern by the partition layer on the substrate, but it is impossible to make the cross-sectional shape of the partition layer a perfect rectangle. For this reason, no matter how strictly the manufacturing conditions are set, at the corner portion (upper edge portion) of the partition layer forming the channel pattern, there exists a curved surface portion (round portion) of several μm to several tens of μm that curves away from the lid material.

[0009] When the partition layer having such a curved surface portion is joined (bonded) to the lid material, the curved surface portion does not contact the lid material. Therefore, in the microchannel chip in which the partition layer and the lid material are joined, although there are differences in size depending on the partition material and the channel fabrication conditions, there is always a floating portion (unbonded portion) that is not joined to the lid material at the edge portion of the partition layer of the channel pattern.

[0010] In a channel pattern in which channels are formed on both sides centered on the channel partition portion, when the areas of the floating portions (the edge portions that become unbonded portions) on both sides (left and right) of the partition layer become large, the channels are completely connected, and contamination of the fluid (specimen) occurs. In this case, it is obvious that the microchannel chip does not function. However, even if the floating portions on both sides (left and right) of the partition layer are not large enough to be connected, contamination of the fluid (specimen) may occur between adjacent channels. This is considered to be because the fluid (specimen) that has penetrated from the floating portion penetrates into the adjacent channel through the aforementioned minute gap (the gap at the interface (bonding surface) between the resin layer and the lid material).

[0011] Therefore, even when the aforementioned minute gap and floating portion occur, it is required to suppress the contamination of the fluid (specimen) between adjacent channels. However, in the conventional technology, it has not been possible to sufficiently suppress the contamination of the fluid (specimen) between adjacent channels.

[0012] The present disclosure has been made in view of the above problems, and an object thereof is to provide a microchannel chip capable of suppressing the occurrence of contamination of the fluid (specimen) between adjacent channels.

Means for Solving the Problems

[0013] A microchannel chip according to one aspect of the present disclosure includes a substrate, a partition layer provided on the substrate and defining a flow channel, and a lid material provided on a surface of the partition layer opposite to the surface in contact with the substrate. In the microchannel chip, the partition layer has a floating portion in a region on the lid material side that is not in contact with the lid material, and when viewed in the thickness direction of the partition layer, the ratio of the width of the floating portion to the width of the partition layer sandwiched between the flow channels is 0% or more and 62% or less.

Advantages of the Invention

[0014] According to the present disclosure, it is possible to provide a microchannel chip capable of suppressing the occurrence of contamination of fluid (specimen) between adjacent flow channels.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0016] One embodiment of the present disclosure will be described. Note that this embodiment shows an example of the present disclosure, and the present disclosure is not limited to this embodiment. In addition, various changes or improvements can be made to this embodiment, and forms with such changes or improvements can also be included in the present disclosure.

[0017] As a result of intensive studies, the inventors of the present invention have found that in a microchannel chip in which a resin layer (hereinafter sometimes referred to as a "partition layer") defining a flow path and a lid material are joined (particularly when they are bonded without using an adhesive), in order to suppress the contamination (contamination) of fluid (specimen) between adjacent flow paths, the ratio of the area (width) of the floating portion (unbonded portion) to the area (width) of the partition layer (hereinafter defined as the "floating width ratio") is important.

[0018] As the floating width ratio (the ratio of the width of the floating portion to the width of the partition layer) increases, the area (width) of the bonded portion between the partition layer and the lid material decreases. For this reason, it penetrates into the minute gaps existing at the interface (bonding surface) between the partition layer (resin layer) and the lid material, and contamination of the fluid (specimen) between adjacent flow paths is likely to occur. Therefore, the inventors of the present invention have found that by satisfying specific conditions for the floating width ratio, it is possible to suppress the contamination of fluid (specimen) between adjacent flow paths.

[0019] The inventors of the present invention have also found that the floating width ratio at which contamination of fluid (specimen) occurs varies greatly depending on the complex elastic modulus of the lid material used. For example, in the case of a lid material using a soft resin with a small complex elastic modulus, the deformation of the surface of the lid material can follow the uneven shape of the surface of the resin layer (partition layer) to some extent, so it is considered that there are few minute gaps, and compared with a lid material of a hard resin, even if the floating width ratio is somewhat larger, contamination of the fluid between the flow paths is less likely to occur. Therefore, even if the floating width ratio is relatively large, contamination does not occur. On the other hand, in the case of a lid material using a hard resin with a large complex elastic modulus, the deformation of the surface of the lid material cannot sufficiently follow the uneven shape of the surface of the resin layer (partition layer), and many minute gaps are generated. For this reason, contamination of the fluid between the flow paths is also likely to occur. Therefore, it is necessary to reduce the floating width ratio. Therefore, the inventors of the present invention have found that by satisfying specific conditions for the complex elastic modulus of the lid material in addition to the floating width ratio, it is possible to more reliably suppress the contamination of fluid (specimen) between adjacent flow paths.

[0020] That is, the first embodiment of the microchannel chip according to the present disclosure includes a substrate, a partition layer provided on the substrate and defining a flow channel, and a lid material provided on a surface of the partition layer opposite to the surface in contact with the substrate. The partition layer has a floating portion in a region on the lid material side that is not in contact with the lid material, and when viewed from the thickness direction of the partition layer, the ratio of the width of the floating portion to the width of the partition layer sandwiched between the flow channels is 0% or more and 62% or less. Also, in this case, it is preferable that the lid material has a complex elastic modulus measured by a micro-indentation test of 1.7 MPa or more and 21 MPa or less.

[0021] Also, the second embodiment of the microchannel chip according to the present disclosure is such that when viewed from the thickness direction of the partition layer, the ratio of the width of the floating portion to the width of the partition layer sandwiched between the flow channels is 41% or less. Also, in this case, it is preferable that the lid material has a complex elastic modulus measured by a micro-indentation test of 1.7 MPa or more and 4600 MPa or less.

[0022] Hereinafter, the microchannel chip according to the first and second embodiments, and the manufacturing method of the microchannel chip according to the first and second embodiments will be described in more detail. The microchannel chips according to the first and second embodiments are the same except that the floating width ratio in the partition layer and the physical properties (complex elastic modulus) of the resin material constituting the lid material are different. Therefore, the microchannel chips according to the first and second embodiments will be described together. The same applies to the manufacturing method of the microchannel chip according to the first and second embodiments. In the following description, the substrate side of the microchannel chip may be referred to as "down", and the side opposite to the substrate side of the microchannel chip (i.e., the lid material side) may be referred to as "up".

[0023] (1) Configuration of the microchannel chip As shown in the plan view of FIG. 1 and the cross-sectional view taken along line A-A of FIG. 2, the microchannel chip according to this embodiment includes a substrate 10, a partition layer 20 provided on the substrate 10, and a lid member 30 provided on a surface of the partition layer 20 opposite to the surface in contact with the substrate 10. Further, the microchannel chip according to this embodiment includes an input portion 1 for introducing a fluid (for example, a liquid), a channel 3 through which the fluid introduced from the input portion 1 flows, and an output portion 2 for discharging the fluid and the air present inside the channel 3 from the channel 3. Although details will be described later, on the channel 3 side of the upper portion (lid member 30 side) of the partition layer 20 that separates adjacent channels 3, there is a floating portion 21 (FIGS. 3 and 4 to be described later) that is not joined (unjoined portion) to the lid member 30.

[0024] The channel 3 is a region surrounded by the substrate 10, the partition layer 20, and the lid member 30, and the pattern is defined by the partition layer 20. The input portion 1 and the output portion 2 are through holes provided in the lid member 30, and the input portion 1 is connected to one end of the channel 3 and the output portion 2 is connected to the other end, respectively. The lid member 30 may have transparency so that the inside of the channel 3 can be visually recognized, or may be opaque. However, in this embodiment, the width of the partition layer 20 and the width of the floating portion 21 to be described later are measured with an optical microscope through either the lid member 30 or the substrate 10. For this reason, either the lid member 30 or the substrate 10 is a transparent or translucent material with respect to the observation light of the optical microscope.

[0025] In the microchannel chip according to this embodiment, at least one input portion 1 and output portion 2 may be provided respectively, or a plurality of each may be provided. Also, in the microchannel chip according to this embodiment, one channel 3 may be provided, or a plurality of channels 3 may be provided. Further, the channel 3 may have a pattern that allows the fluid introduced from the input portion 1 to merge or branch.

[0026] (2) Substrate The substrate 10 can be formed of a light-transmitting material or a non-light-transmitting material. For example, when detecting and observing the state (fluid state) in the flow path 3 from the substrate 10 side by light, it is advisable to use a resin material with excellent transparency to light. Also, when there is no need to detect and observe the state (fluid state) in the flow path 3 from the substrate 10 side by light, a non-translucent material may be used. However, in this embodiment, when measuring the width of the partition layer 20 and the width of the floating portion 21 (described later) from the substrate 10 side with an optical microscope, either the lid member 30 or the substrate 10 needs to be a transparent or semi-transparent material with respect to the observation light of the optical microscope. Examples of the translucent material include resin, glass, etc. Examples of the resin that is a translucent material include acrylic resin, methacrylic resin, polypropylene, polycarbonate, cycloolefin resin, polystyrene, polyester, urethane resin, silicone resin, fluororesin, etc.

[0027] Examples of the non-translucent material include silicon wafers, copper plates, etc. The thickness of the substrate 10 is not particularly limited, but since a certain degree of rigidity is required when manufacturing the microchannel chip, a range of 10 μm (0.01 mm) or more and 10 mm or less is preferable.

[0028] (3) Partition layer The partition layer 20 can be formed of a resin such as a photosensitive resin, for example. Examples of the photosensitive resin include resins that are photosensitive to light with a wavelength in the ultraviolet region of 190 nm or more and 400 nm or less. Examples of such a photosensitive resin include photoresists such as liquid resist or dry film resist. The photoresist can be either a positive type in which the photosensitive region dissolves or a negative type in which the photosensitive region becomes insoluble. Examples of the photosensitive resin composition suitable for forming the partition layer 20 include a radical negative type photosensitive resin composition containing an alkali-soluble polymer, an addition polymerizable monomer, and a photopolymerization initiator.

[0029] The basic structure (skeleton) of the photosensitive resin is not particularly limited as long as it has photosensitivity. For example, acrylic resins, acrylic urethane resins (urethane acrylate resins), epoxy resins, polyamide resins, polyimide resins, polyurethane resins, polyester resins, polyether resins, polyolefin resins, polycarbonate resins, polystyrene resins, norbornene resins, and phenol novolac resins can be mentioned. These may be used alone or in combination of two or more by mixing or copolymerization.

[0030] In addition, in this embodiment, the resin constituting the partition layer 20 is not limited to the photosensitive resin, and for example, a synthetic resin may be used. As the synthetic resin, for example, polymethyl methacrylate (PMMA), polycarbonate (PC), polystyrene (PS), polypropylene (PP), cycloolefin polymer (COP), cycloolefin copolymer (COC), etc. can be used.

[0031] Furthermore, in order to maintain the required height as the flow path 3, the resin constituting the partition layer 20 preferably has the following physical properties. That is, it is preferable that the complex elastic modulus measured by the micro-indentation test is 500 MPa or more, or the hardness measured by the nano-indentation method, which is a kind of micro-indentation test, is 25 MPa or more. Furthermore, the smoother the surface of the partition layer 20 in contact with the lid member 30, the less likely it is to generate minute gaps. Therefore, the height of the protrusions existing on the surface of the partition layer 20 in contact with the lid member 30 is preferably small, for example, preferably 10 μm or less.

[0032] Also, the thickness of the partition layer 20, that is, the height of the flow path 3 is not particularly limited, but it is necessary to make the height of the flow path 3 larger than the substances to be analyzed and inspected contained in the fluid introduced into the flow path 3 (for example, drugs, bacteria, cells, red blood cells, white blood cells, etc.). For this reason, the thickness of the partition layer 20, that is, the height of the flow path 3 is preferably 5 μm or more and 100 μm or less. Similarly, since it is necessary to make the width of the flow path 3 larger than the substance to be analyzed and inspected, the width of the flow path 3 defined by the partition layer 20 is preferably 5 μm or more and 1000 μm or less, and more preferably 5 μm or more and 100 μm or less.

[0033] (4) Cover material In the microchannel chip according to the present embodiment, the cover material 30 covers the flow path 3 as shown in FIG. 2. Further, the cover material 30 is provided on the surface opposite to the surface of the partition layer 20 that contacts the substrate 10, and faces the substrate 10 with the partition layer 20 interposed therebetween. More specifically, as shown in FIG. 2, in a cross-sectional view, the side end portion of the cover material 30 is supported by the partition layer 20, the central region faces the substrate 10, and the central region defines the upper portion of the flow path 3.

[0034] The thickness of the cover material 30 is not particularly limited, but in view of providing through holes corresponding to the input portion 1 and the output portion 2 in the cover material 30, it is preferably in the range of 10 μm (0.01 mm) or more and 10 mm or less, and more preferably in the range of 50 μm or more and 2 mm or less. It is desirable to previously form through holes corresponding to the fluid input portion 1 and output portion 2 in the cover material 30 before bonding with the partition layer 20. Thereby, it is possible to suppress the occurrence of problems such as dust and contamination compared to the case of forming through holes after bonding with the partition layer 20.

[0035] The cover material 30 can be formed of a light-transmitting material or a non-light-transmitting material. For example, when detecting and observing the state (fluid state) in the flow path 3 by light, it is preferable to use a resin material having excellent transparency to the light. When it is not necessary to detect and observe the state (fluid state) in the flow path 3 by light, a non-light-transmitting material may be used. However, in the present embodiment, when measuring the width of the partition layer 20 and the width of the floating portion 21 (described later) from the cover material 30 side with an optical microscope, either the cover material 30 or the substrate 10 needs to be a transparent or translucent material with respect to the observation light of the optical microscope.

[0036] Examples of the resin material constituting the cover member 30 include silicone rubber (e.g., polydimethylsiloxane (PDMS)) and synthetic resins. Examples of synthetic resins include acrylic resin, methacrylic resin (e.g., polymethyl methacrylate (PMMA)), polypropylene (PP), polycarbonate (PC), polystyrene (PS), cycloolefin polymer (COP), cycloolefin copolymer (COC), polyester (e.g., polyethylene terephthalate (PET)), polyurethane, polyvinyl chloride, silicone resin, fluororesin, etc.

[0037] (5) Intermediate layer The microchannel chip according to the present embodiment may include an intermediate layer between the substrate 10 and the partition layer 20. That is, the microchannel chips of FIGS. 1 and 2 may include the substrate 10, an intermediate layer (not shown) disposed on the substrate 10, the partition layer 20 disposed on the intermediate layer, and the cover member 30 disposed on the partition layer 20.

[0038] Examples of the intermediate layer include an adhesion layer for improving the adhesion between the substrate 10 and the partition layer 20, and a light-shielding layer for imparting light-shielding properties to the microchannel chip. When glass is used as the substrate 10, it is preferable to provide an adhesion layer between the substrate 10 and the partition layer 20. Examples of the adhesion layer include a hydrophobized surface treatment layer formed by performing a hydrophobized surface treatment (HMDS treatment) on the surface of the substrate 10, and a resin thin film coated on the surface of the substrate 10.

[0039] When the microchannel chip according to the present embodiment has an adhesion layer, the fluid (e.g., liquid) flowing through the flow path 3 will contact the adhesion layer instead of the substrate 10. Therefore, it is preferable that the adhesion layer has resistance to the fluid introduced into the flow path 3. By providing an adhesion layer on the substrate 10, the resolution of the pattern of the flow path formed by the photosensitive resin may be improved.

[0040] (6) Protruding portion When joining the partition layer 20 and the cover material 30, the microchannel chip according to this embodiment has a floating portion that is not bonded to the cover material 30 at the edge portion (edge) of the partition layer 20 on the cover material 30 side. This floating portion is also referred to as an unbonded portion. Hereinafter, the details of the floating portion will be described with reference to FIGS. 3 and 4. FIG. 3 is a view showing the floating portion 21 in a plan view, that is, as viewed from the thickness direction, of the microchannel chip according to this embodiment. In FIG. 3, for ease of understanding, the cover material 30 is indicated by a dashed line, and the input portion 1, the output portion 2, the flow paths 3 (flow paths 3a, 3b, 3c), and the partition layer 20 viewed in plan through the cover material 30 are shown. FIG. 4 is a cross-sectional view of the microchannel chip shown in FIG. 3 cut along the line B-B, that is, a virtual line orthogonal to the flow path length direction of the flow path 3.

[0041] As shown in FIGS. 3 and 4, the floating portion 21 is formed at the corner portion on the flow path 3 side of the upper end portion (cover material 30 side end portion) in the partition layer 20 that separates a plurality of adjacent flow paths 3. In this example, the floating portion 21 in the partition layer 20 that separates the flow path 3a and the flow path 3b will be described, but the floating portion of the partition layer 20 that separates the flow path 3b and the flow path 3c has the same configuration.

[0042] As shown in FIG. 4, in the partition layer 20 that separates the flow path 3a and the flow path 3b, floating portions 21a and 21b are formed on each flow path side. The floating portion 21a is formed at the corner portion on the flow path 3a side of the upper end portion in the partition layer 20, and the floating portion 21b is formed at the corner portion on the flow path 3b side of the upper end portion in the partition layer 20. In this example, the partition layer 20 and the cover material 30 are joined (bonded) in the joining region 22, and the floating portions 21a and 21b of the partition layer 20 are unbonded regions that are not bonded to the cover material 30.

[0043] When forming the partition layer 20 (when forming the flow path pattern) on the substrate 10, a curved surface portion (round portion), which is a curved surface shape region with a width of several μm to several tens of μm that curves away from the lid material, may occur at the upper end portion of the partition layer 20 on the flow path 3 side. This round portion becomes a portion that does not join (contact) with the lid material 30 at the upper end portion of the partition layer 20, that is, a floating portion 21 (floating portions 21a, 21b). The floating portion 21 is not joined to the lid material 30, that is, it is not joined (bonded) to the lid material 30. Therefore, a fluid (specimen) can flow through the region between the floating portion 21 and the lid material 30. Also, the width of the flow path 3 expands from the end portion on the substrate 10 side of the floating portion 21 toward the end portion on the lid material 30 side. That is, the width of the flow path 3 expands by the amount of the floating portion 21 on the lid material 30 side (upper part of the flow path) and is wider than on the substrate 10 side.

[0044] In the microchannel chip according to the present embodiment, when a transparent or translucent material is used as the lid material 30, the widths (line widths) of the partition layer 20 and the floating portion 21 can be measured by observing the microchannel chip after bonding (joining) the lid material 30 from the upper surface side with an optical microscope. Specifically, the width W1 of the partition layer 20 and the widths W2, W3 of the floating portions 21a, 21b on each flow path side (both left and right edge portions) at the upper end portion of the partition layer 20 can be measured. By adding the widths W2, W3 of the floating portions 21a, 21b and dividing the sum by the width W1 of the partition layer 20, the ratio (floating width ratio) of the width (the sum of the widths W2, W3) of the floating portion 21 (floating portions 21a, 21b) to the width W1 of the partition layer 20 can be calculated (Equation 1 below). Floating width ratio [%] = (width W2 + width W3) / width W1 × 100 ··· (Equation 1)

[0045] In the microchannel chip according to the present embodiment, when viewed from the thickness direction of the partition layer 20 (here, the cover material 30 side), the ratio of the width of the floating portion 21 to the width W1 of the partition layer 20 sandwiched between the channels 3 (for example, channels 3a and 3b) (floating width ratio) is in the range of 0% or more and 62% or less. When the floating width ratio exceeds 62%, the bonding region 22 cannot be sufficiently secured, and when fluid (specimen) enters the bonding region 22 from the channel 3 through a minute gap, contamination of the fluid (specimen) may occur between the channels 3. If the floating width ratio is 62% or less, the bonding region 22 can be sufficiently secured and the occurrence of fluid contamination between the channels 3 can be suppressed. When a transparent or translucent material is used for the substrate 10, as the thickness direction, the microchannel chip after bonding (joining) of the substrate 10 can be observed with an optical microscope from the bottom surface side, and the widths W1, W2, and W3 can be measured.

[0046] In the microchannel chip according to the present embodiment, when the floating width ratio is 62% or less, it is preferable that the complex elastic modulus of the cover material 30 is 1.7 MPa or more and 21 MPa or less. Thereby, when bonding (joining) the partition layer 20 and the cover material 30, the shape deformation of the surface (rear surface 30a) on the partition layer 20 side of the cover material 30 in the bonding region 22 follows well the uneven shape of the surface (front surface 20a) on the cover material 30 side of the partition layer 20. For this reason, the generation of minute gaps in the bonding region 22 (interface between the partition layer 20 and the cover material 30) is suppressed, and even when the floating width ratio is relatively high (exceeding 41 and 62% or less), the occurrence of contamination of the fluid (specimen) between the adjacent channels 3 can be suppressed. Furthermore, the partition layer 20 and the cover material 30 can be firmly joined without using an adhesive. Here, the complex elastic modulus of the cover material 30 is measured by a micro-indentation test at a temperature of 25°C. The method for measuring the complex elastic modulus will be described later.

[0047] When the complex elastic modulus of the lid member 30 is in the range of 1.7 MPa or more and 21 MPa or less, the lid member 30 is preferably formed using a soft resin. Thereby, the complex elastic modulus of the lid member 30 can be favorably controlled. Specifically, as the soft resin, the lid member 30 preferably contains at least one of polydimethylsiloxane, silicone rubber, polyurethane, and polyvinyl chloride. By using these materials, when the partition layer 20 and the lid member 30 are bonded (joined), the back surface 30a of the lid member 30 can be favorably made to follow the surface 20a of the partition layer 20 in the bonding region 22.

[0048] Also, the floating width ratio is more preferably 41% or less (in the range of 0% or more and 41% or less). If the floating width ratio is 41% or less, the occurrence of contamination of the fluid (specimen) between adjacent channels 3 in the microchannel chip can be more reliably reduced. In the microchannel chip according to the present embodiment, when the floating width ratio is 41% or less, the complex elastic modulus of the lid member 30 measured by the micro-indentation test may be in the range of 1.7 MPa or more and 4600 MPa or less. By setting the floating width ratio to 41% or less, even when the followability of the lid member 30 to the surface 20a of the partition layer 20 in the bonding region 22 is somewhat reduced, the occurrence of contamination of the fluid (specimen) between adjacent channels 3 can be suppressed. That is, compared with the case where the floating width ratio is 62% or less, by using a harder resin material for the lid member 30, it is possible to allow a reduction in followability. For this reason, the selection range of the material of the lid member 30 can be expanded.

[0049] When the complex elastic modulus of the lid material 30 is in the range of 1.7 MPa or more and 4600 MPa or less, the lid material 30 can be formed using the above-mentioned soft resin or hard resin. As the soft resin, at least one of polydimethylsiloxane, silicone rubber, polyurethane, and polyvinyl chloride can be used as described above. Further, the lid material 30 preferably contains at least one of polymethyl methacrylate (PMMA), polycarbonate (PC), polystyrene (PS), polypropylene (PP), cycloolefin polymer (COP), cycloolefin copolymer (COC), and polyethylene terephthalate (PET) as the hard resin. By using these materials, the back surface 30a of the lid material 30 can be made to follow the surface 20a of the partition layer 20 in the joining region 22 to such an extent that the mixing of the fluid (specimen) between the adjacent flow paths 3 is suppressed.

[0050] (7) Measurement of the complex elastic modulus of the lid material The complex elastic modulus of the lid material 30 in the present embodiment, that is, the complex elastic modulus of the resin material constituting the lid material 30, is a physical property value representing the hardness of the elastic deformation component of the resin material, and is measured by a micro-indentation test in a temperature environment of 25°C. Since the specific measurement method conforms to the international standard ISO14577 by the International Organization for Standardization (ISO), the description is omitted.

[0051] The apparatus used for measuring the complex elastic modulus measures the physical properties of a micro-region and a micro-depth on the order of nanometers (nm) applying a scanning probe microscope, such as a nano-indentation apparatus (manufactured by Oxford Instruments, etc.), or measures the physical properties of a micro-region and a micro-depth on the order of micrometers (μm), such as a micro-indentation apparatus (manufactured by Fischer, etc.). However, when measuring the constituent materials (lid material 30, partition layer 20) of a micro-channel composed of members on the order of μm, almost the same physical property values are measured as long as the measurement method conforms to ISO14577 regardless of which apparatus is used. Therefore, for measuring the complex elastic modulus in the present embodiment, either a micro-indentation apparatus or a nano-indentation apparatus can be used for the micro-indentation test. Note that the measurement of the complex elastic modulus of the lid member 30 shows that the physical property values do not change before and after bonding (joining) with the partition layer 20. Therefore, it may be carried out either before or after bonding.

[0052] (8) Method for manufacturing a microchannel chip The method for manufacturing the microchannel chip according to the present embodiment will be described with reference to FIG. 5. Here, the case where the partition layer 20 is formed of a photosensitive resin will be described as an example. Each drawing in FIG. 5 is a cross-sectional view when the substrate 10 etc. are cut in a plane parallel to the direction in which the flow path 3 extends and perpendicular to the surface of the substrate 10.

[0053] The method for manufacturing the microchannel chip according to the present embodiment includes a coating step of coating a photosensitive resin on the substrate 10, an exposure step of exposing the coated photosensitive resin, a development step of developing and washing the exposed photosensitive resin to form a partition layer 20 that defines the flow path 3 on the substrate 10, and a bonding step of bonding a lid member 30 to the surface of the partition layer 20 opposite to the surface in contact with the substrate 10.

[0054] <Coating step> First, the coating step is carried out. By the coating step, a photosensitive resin layer 51 for forming the partition layer 20 is formed on the substrate 10. The method of coating the photosensitive resin on the substrate 10 is not particularly limited, and examples include spin coating, spray coating, bar coating, etc. Among these methods, spin coating is preferable from the viewpoint of controllability of the film thickness.

[0055] On the substrate 10, photosensitive resins in various forms such as liquid, solid, gel, film, etc. can be coated. Among these, it is preferable to form the photosensitive resin layer 51 with a liquid resist. The thickness of the photosensitive resin layer 51 is not particularly limited, but the thickness of the photosensitive resin layer 51 may be set so that the thickness of the completed partition layer 20 becomes the target value, and then the photosensitive resin may be coated. In addition, when the photosensitive resin contains a solvent, the solvent may be removed from the photosensitive resin layer 51 by methods such as heat treatment and reduced pressure treatment.

[0056] <Exposure process> Following the coating process, an exposure process is carried out. That is, the pattern of the flow path 3 is drawn on the photosensitive resin layer 51 on the substrate 10 by exposure. The type of light used for exposure is not particularly limited, and ultraviolet light or a laser can be used. That is, the exposure can be performed, for example, by an exposure apparatus that irradiates ultraviolet light or a laser drawing apparatus.

[0057] Among these, exposure using a proximity exposure apparatus or a contact exposure apparatus that irradiates ultraviolet light is preferable. In the case of a proximity exposure apparatus, exposure is performed through a photomask having the pattern of the flow path in the microchannel chip. As this photomask, for example, a photomask having a film with a two-layer structure of chromium and chromium oxide as a light-shielding film may be used.

[0058] When a photosensitive resin having photosensitivity to light with a wavelength in the ultraviolet light region of 190 nm or more and 400 nm or less is used as the photosensitive resin, for the exposure, light with a wavelength in the ultraviolet light region of 190 nm or more and 400 nm or less is used to make the photosensitive resin sensitive to light with a wavelength of 190 nm or more and 400 nm or less.

[0059] When the photosensitive resin coated on the substrate 10 is a positive resist, the exposed area is dissolved to form the flow path 3, and the photosensitive resin remaining in the unexposed area becomes the partition layer 20. Also, when the photosensitive resin coated on the substrate 10 is a negative resist, the photosensitive resin remaining in the exposed area becomes the partition layer 20, and the unexposed area is dissolved to form the flow path 3. FIG. 4 is an example in the case where the photosensitive resin is a negative resist, reference numeral 52 is the exposed area, and reference numeral 53 is the unexposed area.

[0060] Thus, in the method for manufacturing the microchannel chip according to this embodiment, the partition layer 20 that defines the channel 3 can be formed on the substrate 10 using photolithography. In addition, when a chemically amplified resist or the like is used for forming the partition layer 20 on the substrate 10, in order to promote the catalytic reaction of the acid generated by exposure, a heat treatment (post-exposure bake: PEB) may be further performed after exposure.

[0061] <Development process> Next, the exposed photosensitive resin is developed to form the pattern of the channel 3 (channel pattern). The development is performed, for example, by reacting the photosensitive resin with a developer in a developing apparatus such as a spray type, dip type, or paddle type. As described above, when forming the channel pattern in the development process, a curved floating portion 21 may occur at the edge portion of the upper end of the partition layer 20 that constitutes the channel pattern.

[0062] As the developer, for example, an aqueous sodium carbonate solution, an aqueous tetramethylammonium hydroxide solution, an aqueous potassium hydroxide solution, or an organic solvent can be used. The developer may be appropriately selected according to the characteristics of the photosensitive resin and is not limited to the above. Also, the concentration of the developer and the development treatment time may be adjusted to suitable conditions according to the characteristics of the photosensitive resin.

[0063] After development, washing is performed to remove the developer used in the development process from the photosensitive resin layer 51 on the substrate 10. The washing method is not particularly limited, but can be performed, for example, by a washing apparatus such as a spray type, shower type, or immersion type. As the washing liquid, for example, pure water, isopropyl alcohol, etc. can be used, but a washing liquid suitable for removing the developer used in the development process may be appropriately selected. After washing, drying may be performed by a spin dryer, IPA vapor dryer, natural drying, etc.

[0064] <Surface modification process> After the development process is completed, before performing the bonding process, a surface modification treatment may be performed to modify one or both of the surface of the partition layer 20 and the surface of the lid member 30. Examples of the surface modification treatment include plasma treatment, UV (ultraviolet) treatment, corona discharge treatment, and excimer laser treatment. By imparting a functional group such as a hydroxy group (-OH) to one or both of the surface of the partition layer 20 and the surface of the lid member 30 by the surface modification treatment, the bonding strength between the partition layer 20 and the lid member 30 in the subsequent bonding process can be increased.

[0065] <Bonding process> Next, the lid member 30 is bonded to the surface of the partition layer 20 on the side opposite to the surface in contact with the substrate 10. By bonding the lid member 30, the flow path 3 is covered with the lid member 30, and the micro flow path chip shown in FIGS. 1 and 2 is obtained. Here, when the corner portion of the edge portion of the upper end portion of the partition layer 20 is in a curved surface shape (round portion) at the time of forming the flow path pattern, a micro flow path chip having the floating portions 21 shown in FIGS. 3 and 4 is obtained. As described above, when viewed from the thickness direction of the partition layer 20 (for example, the lid member 30 side), the ratio (floating width ratio) of the width (widths W2 and W3) of the floating portions 21 to the width W1 (see FIG. 4) of the partition layer 20 sandwiched between the flow paths 3 may be 0% or more and 62% or less, and more preferably 41% or less. Further, when the floating width ratio is 62% or less, the complex elastic modulus of the lid member 30 to be bonded is preferably 1.7 MPa or more and 21 MPa or less. When the floating width ratio is 41% or less, the complex elastic modulus of the lid member 30 to be bonded is preferably 1.7 MPa or more and 4600 MPa or less. Thereby, the followability of the lid member 30 in the bonding region 22 (see FIG. 4) can be suitably controlled according to the floating width ratio.

[0066] The method of bonding the partition layer 20 and the lid member 30 is not particularly limited, and bonding may be performed using an adhesive. However, if the physical properties of the resin material constituting the lid member 30 (the complex elastic modulus of the lid member 30) and the floating width ratio in the partition layer 20 satisfy the above requirements, bonding can be performed without using an adhesive. That is, if the floating width ratio in the partition layer 20 satisfies the above requirements, a sufficient bonding region 22 for bonding (laminating) the lid material 30 and the partition layer 20 can be ensured. Also, if the complex elastic modulus of the lid material 30 satisfies the above requirements, when the partition layer 20 and the lid material 30 are laminated, the surface (back surface 30a) of the lid material 30 on the side of the partition layer 20 in the bonding region 22 follows the uneven shape of the surface of the partition layer 20. Therefore, the partition layer 20 and the lid material 30 are firmly adhered to each other, and it is difficult for minute gaps to occur at the interface between the partition layer 20 and the lid material 30.

[0067] As a method for bonding the partition layer 20 and the lid material 30, for example, thermocompression bonding can be used. This is a method used for heating and pressure bonding (pressing) to closely adhere and laminate the partition layer 20 and the lid material 30. The temperature conditions for bonding the partition layer 20 and the lid material 30 are not particularly limited, and bonding may be performed at room temperature or at a temperature higher than room temperature. The temperature conditions may be appropriately set according to the above physical properties of the resin material constituting the lid material 30 and the following pressure conditions. The temperature conditions are preferably, for example, a temperature equal to or higher than room temperature and not exceeding the heat-resistant temperature of the resin material, more preferably 40°C or higher and 200°C or lower, and even more preferably 60°C or higher and 100°C or lower. In the present invention, room temperature means 20°C.

[0068] Also, the pressure conditions for bonding the partition layer 20 and the lid material 30 are not particularly limited, and bonding may be performed without applying pressure to the partition layer 20 and the lid material 30, or bonding may be performed while applying pressure to one or both of the partition layer 20 and the lid material 30. The pressure conditions may be appropriately set according to the above physical properties of the resin material constituting the lid material 30 and the above temperature conditions. The pressure conditions are preferably, for example, 0.001 MPa or more and 1 MPa or less, and more preferably 0.001 MPa or more and 0.01 MPa or less. Depending on the above physical properties of the resin material constituting the lid material 30 and the above temperature conditions, deformation may occur due to its own weight even without applying any pressure, so it is also possible to perform bonding without applying any pressure.

[0069] In addition, when the resin material constituting the lid member 30 is polydimethylsiloxane, the temperature condition is preferably 100°C or higher and 200°C or lower, and the pressure condition is preferably 0.001 MPa or higher and 0.01 MPa or lower. When the resin material is silicone rubber, the temperature condition is preferably 100°C or higher and 200°C or lower, and the pressure condition is preferably 0.001 MPa or higher and 0.01 MPa or lower.

[0070] When the resin material is polyurethane, the temperature condition is preferably 60°C or higher and 100°C or lower, and the pressure condition is preferably 0.005 MPa or higher and 0.05 MPa or lower. When the resin material is polyvinyl chloride, the temperature condition is preferably 20°C or higher and 60°C or lower, and the pressure condition is preferably 0.005 MPa or higher and 0.05 MPa or lower. When the resin material is polyethylene terephthalate, polycarbonate, polymethyl methacrylate, or cycloolefin polymer, the temperature condition is preferably 40°C or higher and 90°C or lower, and the pressure condition is preferably 0.01 MPa or higher and 1 MPa or lower.

[0071] As a specific method for joining the partition layer 20 and the lid member 30, for example, thermocompression bonding using a hot press machine or a hot roll machine can be mentioned. Further, the joining method is not limited to thermocompression bonding, and the partition layer 20 and the lid member 30 may be joined using an adhesive (for example, an adhesive, a sealant, a double-sided tape, an adhesive tape, etc.). The type of adhesive to be used can be determined based on the affinity with the materials constituting the partition layer 20 and the lid member 30. For example, an acrylic resin-based adhesive, a urethane resin-based adhesive, an epoxy resin-based adhesive, etc. can be used.

[0072] (Effects of this embodiment) In the case of the microchannel chips of the first and second embodiments, the following-described effects can be achieved. (1) The microchannel chip according to the first embodiment includes a substrate 10, a partition layer 20 provided on the substrate 10 and defining a flow path 3, and a lid member 30 provided on a surface 20a opposite to the surface of the partition layer 20 in contact with the substrate 10. In the microchannel chip, the partition layer 20 has a floating portion 21 in a region on the lid member 30 side that is not in contact with the lid member 30, and when viewed from the thickness direction of the partition layer 20, the ratio of the width of the floating portion 21 to the width of the partition layer 20 sandwiched between the flow paths 3 is 0% or more and 62% or less. According to this configuration, it is possible to provide a microchannel chip capable of suppressing the occurrence of contamination of fluid (specimen) between adjacent flow paths. (2) In the microchannel chip of (1) above, the lid member 30 preferably has a complex elastic modulus measured by a micro-indentation test of 1.7 MPa or more and 21 MPa or less. According to this configuration, since the lid member follows well the uneven shape of the surface of the partition layer, the generation of minute gaps in the bonding region is suppressed, and the occurrence of contamination of fluid (specimen) between adjacent flow paths can be surely suppressed. (3) The lid member 30 in the microchannel chips of (1) and (2) above preferably contains at least one of polydimethylsiloxane, silicone rubber, polyurethane, and polyvinyl chloride. According to this configuration, when bonding (joining) the partition layer and the lid member, the back surface of the lid member can be made to follow well the surface of the partition layer in the bonding region. (4) In the microchannel chip according to the second embodiment, when viewed from the thickness direction of the partition layer 20, the ratio of the width of the floating portion 21 to the width of the partition layer 20 sandwiched between the flow paths 3 is 41% or less According to this configuration, the occurrence of contamination of fluid (specimen) between adjacent flow paths in the microchannel chip can be more surely reduced. (5) In the lid material 30 of the microchannel chip described in (4) above, the complex elastic modulus measured by the micro-indentation test is preferably 1.7 MPa or more and 4600 MPa or less. According to this configuration, even when a hard resin material is used for the lid material 30 when the floating width ratio is 41% or less, it is possible to suppress the occurrence of mixing of fluid (specimen) between adjacent channels 3. (6) The lid material 30 in the microchannel chips described in (4) and (5) above preferably contains at least one of polydimethylsiloxane, silicone rubber, polyurethane, polyvinyl chloride, polymethyl methacrylate (PMMA), polycarbonate (PC), polystyrene (PS), polypropylene (PP), cycloolefin polymer (COP), cycloolefin copolymer (COC), and polyethylene terephthalate (PET). According to this configuration, the back surface of the lid material can be made to follow the surface of the partition layer in the bonding region to such an extent that mixing of fluid (specimen) between adjacent channels can be suppressed. (7) In the microchannel chips described in (1) and (4) above, the partition layer 20 is preferably made of a photosensitive resin having photosensitivity to light with a wavelength of 190 nm or more and 400 nm or less in the ultraviolet light region. According to this configuration, a channel pattern formed by the partition layer can be suitably formed on the substrate by photolithography.

Examples

[0073] The present invention will be specifically described below with reference to examples, but the present invention is not limited to the following examples. Microchannel chips of Examples 1 to 56 and Comparative Examples 1 to 24 were manufactured according to the procedure described below.

[0074] <Formation of partition layer> First, a transparent photosensitive resin was coated onto a glass substrate in the shape of a square with a side length of 10 cm to form a photosensitive resin layer. As the photosensitive resin, a negative-type photosensitive resin (model number KMPR1035 manufactured by Nippon Kayaku Co., Ltd.) with an epoxy resin as the backbone was used. The photosensitive resin was coated onto the glass substrate using a spin coater. The rotation speed and coating time were adjusted so that the film thickness of the photosensitive resin layer would be 50 μm, with a rotation speed of 1700 rpm and a coating time of 30 seconds.

[0075] Next, for the purpose of removing the solvent contained within the photosensitive resin layer, heat treatment (pre-bake) was performed using a hot plate. The pre-bake was carried out at a temperature of 90 °C for 20 minutes. Next, the photosensitive resin layer on the glass substrate was exposed to light to draw the pattern of the flow path. Specifically, pattern exposure was performed on the photosensitive resin layer through a photomask having a pattern array of micro flow paths. As the photomask, a photomask having a film with a two-layer structure of chromium and chromium oxide as the light-shielding film was used. For the exposure, a proximity exposure apparatus was used. The exposure apparatus used a high-pressure mercury lamp as the light source, and the exposure wavelength was a broadband including g-line, h-line, and i-line. The exposure amount for forming the flow path pattern was 500 mJ / cm 2 was set.

[0076] Next, heat treatment (post-exposure bake: PEB) was performed on the exposed photosensitive resin layer at 100 °C for 240 seconds, followed by development to form the pattern of the flow path. The development conditions were such that the photosensitive resin layer was developed for 360 seconds using an alkaline developer (an aqueous solution containing 2.38 mass% of tetramethylammonium hydroxide) to dissolve the unexposed portions and pattern the flow path structure. Subsequently, shower rinsing with ultrapure water was performed to remove the developer from the photosensitive resin layer on the substrate, and drying was carried out using a spin dryer to form the partition layer. In the above process, the design dimensions of the flow path pattern were such that the width of the opening (flow path width) was constant at 50 μm, and the width of the partition layer was fabricated at two levels of 50 μm and 100 μm. In order to vary the size of the round portion (i.e., the floating portion) at the upper end (corner) of the partition layer, the focus offset during exposure was varied from -100 μm to +100 μm (the just focus was 0 μm) for exposure. In proximity exposure, by shifting the focus, it is possible to blunt the formed pattern. The floating width after attaching the cover material can be intentionally controlled by the size of the roundness.

[0077] <Cutting> The glass substrate with the partition layer formed was cut into a size suitable for observation with a microscope. The size was 25 mm in length and 75 mm in width. Then, it was washed with a shower of pure water and dried with an air blow.

[0078] <Preparation of Cover Material> Two types of silicone rubbers (Silicone Rubber - 1, Silicone Rubber - 2) and two types of PDMS resins (PDMS - 1, PDMS - 2) were used as soft resin cover materials, and polyethylene terephthalate (PET), polycarbonate (PC), cycloolefin polymer (COP), and polymethyl methacrylate (PMMA) were used as hard resin cover materials. Films (plates) with a thickness of 1.5 mm composed of each soft resin and hard resin were prepared respectively. Then, these films were cut into a size of 25 mm in length and 75 mm in width to fabricate the cover materials. Further, punching or cutting processes were performed on the cover materials to open through - holes with a diameter of 1 mm corresponding to the input and output portions.

[0079] Among the soft resins, the above-mentioned silicone rubber is the "Ultra-Transparent Silicone Rubber Sheet·GSSC Series" manufactured by Tomita Mattex Co., Ltd., and two types with different hardnesses (Silicone Rubber-1, Silicone Rubber-2) were used. The complex elastic modulus of Silicone Rubber-1 was 1.7 MPa, and the complex elastic modulus of Silicone Rubber-2 was 5.9 MPa. Also, the above PDMS resin is "KER-4690" manufactured by Shin-Etsu Silicone Co., Ltd., and two types with different hardnesses (PDMS-1, PDMS-2) were used here as well. The complex elastic modulus of PDMS-1 was 6.1 MPa, and the complex elastic modulus of PDMS-2 was 21 MPa. Even if the materials are the same, by varying the time and temperature of the curing treatment of the materials, lid materials with different complex elastic moduli are produced in this way. Among the hard resins, the above-mentioned polyethylene terephthalate is the polyethylene terephthalate "Clapet (registered trademark)" manufactured by Kuraray Co., Ltd. Also, the above polycarbonate is the polycarbonate resin "Panlite (registered trademark)" manufactured by Teijin Limited. Also, the above cycloolefin polymer is the cycloolefin polymer "ZEONOR (registered trademark)" manufactured by Nippon Zeon Co., Ltd. Also, the above polymethyl methacrylate is the methacrylic resin sheet "Comogras (registered trademark)" manufactured by Kuraray Co., Ltd.

[0080] <Evaluation of the Complex Elastic Modulus of the Lid Material> The physical properties of the resin material constituting the lid material, that is, the complex elastic modulus, were measured by the nanoindentation method. The nanoindentation method is a measurement method in which a quasi-static indentation test is performed on the object to be measured to obtain the mechanical properties of the object to be measured. The film used for the production of the lid material was cut to produce a test piece in the shape of a square with a side length of 2 cm, and it was adhered to the sample stage of the measuring device using an instant adhesive (Aron Alpha (trade name) manufactured by Toagosei Co., Ltd.).

[0081] As the measuring device for the complex elastic modulus, a nanoindenter "Hysitron TI-Premier (trade name)" manufactured by Bruker Japan Co., Ltd. was used. As the indenter used for indentation, a Berkovich-type diamond indenter manufactured by Bruker Japan Co., Ltd. was used. Then, the measurement by the nanoindentation method was carried out as follows. That is, in the displacement control mode, the indenter was pushed in at a pushing speed of 100 nm / second to a depth of 500 nm, held for 5 seconds at the maximum depth, and then unloaded at a speed of 100 nm / second. Such an operation was performed at 30 measurement points on the surface of the test piece. The interval between each measurement point was set to be 100 μm or more apart.

[0082] From the data obtained in the above measurement, the complex elastic modulus was calculated. That is, the unloading curve in the 60 - 95% region with respect to the maximum load during unloading was analyzed by the Oliver - Pharr method to calculate the complex elastic modulus. For fused silica used as a standard sample, the same measurement was also carried out to obtain the relationship between the contact depth and the contact projected area of the indenter and the test piece, and the measurement data of the test piece was calibrated using that data.

[0083] <Bonding of the cover material> A cover material was bonded to a cut glass substrate with a partition layer formed thereon to fabricate a microchannel chip. At that time, surface modification treatment (10000 mJ / cm 2 ) by UV treatment was performed on each bonding surface of the partition layer and the cover material, and then the two bonding surfaces were brought into contact and bonded by heat treatment using a hot plate.

[0084] When the cover material is a soft resin (silicone rubber, PDMS resin), in order to prevent misalignment between the two bonding surfaces, heat treatment was carried out with a metal plate with a mass of 800 g (equivalent pressure 0.00418 MPa) placed on the cover material as a weight to perform the bonding.

[0085] When the cover material is composed of a hard resin (polyethylene terephthalate (PET), polycarbonate (PC), cycloolefin polymer (COP), polymethyl methacrylate (PMMA)), the bonding was carried out while applying a load of 500 kg (equivalent pressure 2.61 MPa) using a hot press device so that the two bonding surfaces were in contact over the entire surface.

[0086] The temperature of the heat treatment was set to a temperature that did not exceed the heat resistance temperature of each resin material. Specifically, when the resin material of the lid material was a soft resin (silicone rubber and PDMS resin), the heat treatment conditions were 200 °C for 10 minutes. When it was a hard resin (polyethylene terephthalate, polycarbonate, cycloolefin polymer, polymethyl methacrylate), the conditions were 60 °C for 10 minutes.

[0087] In this way, a plurality of microchannel chip samples were prepared such that the material of the lid material, the designed width of the partition layer, and the floating width after joining (bonding) the lid material in the partition layer were different, and Examples 1 to 56 and Comparative Examples 1 to 24 were obtained.

[0088] <Measurement of the floating width ratio of the partition layer> For each sample (Example, Comparative Example) of the microchannel chip prepared as described above, the actual width W1 of the partition layer and the widths W2, W3 of the floating parts in each sample were measured with an optical microscope, and the floating width ratio was calculated based on the above formula 1. <Evaluation of fluid contamination between channels> Using a pipettor, water was injected only into the central one of the three channels (channel 3b in FIG. 4) of each sample of the microchannel chip through the input part, and it was observed whether water penetrated into any of the adjacent channels on both sides (channels 3a, 3c in FIG. 4). When water did not penetrate into any of the channels on both sides, it was evaluated as no liquid leakage, and when water penetrated into any of the channels, it was evaluated as having liquid leakage. <Evaluation of the usability of the microchannel> In the above evaluation of fluid contamination, it was observed whether the injected water was passed through to the output part. When there was no liquid leakage and the water was passed through to the output part, it was evaluated as "yes (usable as a microchannel chip)", and when there was liquid leakage or the water was not sufficiently passed through to the output part, it was evaluated as "no (not usable as a microchannel chip)".

[0089] The results of the above measurements and evaluations are shown in Tables 1 to 4 in combination with the configurations of each sample (Examples and Comparative Examples). Note that Tables 1 and 2 show the evaluations of samples using a soft resin for the lid material, and Tables 3 and 4 show the evaluations of samples using a hard resin for the lid material.

[0090]

Table 1

[0091]

Table 2

[0092]

Table 3

[0093]

Table 4

[0094] As shown in Tables 1 and 2, in the microchannel chip using a soft resin for the lid material, if the floating width ratio is within the range of 0% or more and 62% or less when viewed from the thickness direction of the partition layer, like the samples of Examples 1 to 32, no liquid leakage to the adjacent channels occurs, and the liquid (water) injected from the input part is passed through to the output part, indicating that there is no problem as a channel. On the other hand, as in the samples of Comparative Examples 1 to 8, when the floating width ratio exceeds 62% in the microchannel chip using a soft resin for the lid material, liquid leakage to the adjacent channels occurs, and the liquid (water) introduced from the input part is not sufficiently passed through to the output part, indicating that there is a problem in using it as a channel.

[0095] Also, as shown in Tables 3 and 4, in the channel chip using a hard resin for the lid material, if the floating width ratio is within the range of 0% or more and 41% or less, like the samples of Examples 33 to 56, no liquid leakage to the adjacent channels occurs, and the liquid (water) injected from the input part is passed through to the output part, indicating that there is no problem as a channel. On the other hand, in the microchannel chip using a hard resin for the lid material as in the samples of Comparative Examples 9 to 24, when the floating width ratio exceeds 41%, liquid leakage occurs into the adjacent channels and the liquid (water) introduced from the input section cannot be sufficiently passed through to the output section, indicating that there is a problem in using it as a channel.

[0096] Also, for example, the present embodiment can adopt the following configurations. (1) A substrate, A partition layer provided on the substrate and defining a channel, In a microchannel chip including a lid material provided on a surface of the partition layer opposite to the surface in contact with the substrate, The partition layer has a floating portion in a region on the lid material side that is not in contact with the lid material, A microchannel chip in which, when viewed in the thickness direction of the partition layer, the ratio of the width of the floating portion to the width of the partition layer sandwiched by the channels is 0% or more and 62% or less. (2) The lid material is the microchannel chip according to (1) above, in which the complex elastic modulus measured by a micro-indentation test is 1.7 MPa or more and 21 MPa or less. (3) The lid material is the microchannel chip according to (1) or (2) above, containing at least one of polydimethylsiloxane, silicone rubber, polyurethane, and polyvinyl chloride. (4) The microchannel chip according to (1) above, in which, when viewed in the thickness direction of the partition layer, the ratio of the width of the floating portion to the width of the partition layer sandwiched by the channels is 41% or less. (5) The lid material is the microchannel chip according to (4) above, in which the complex elastic modulus measured by a micro-indentation test is 1.7 MPa or more and 4600 MPa or less. (6) The cover material is the microchannel chip according to the above (4) or (5), containing at least one of polydimethylsiloxane, silicone rubber, polyurethane, polyvinyl chloride, polymethyl methacrylate (PMMA), polycarbonate (PC), polystyrene (PS), polypropylene (PP), cycloolefin polymer (COP), cycloolefin copolymer (COC), and polyethylene terephthalate (PET). (7) The microchannel chip according to any one of the above (1) to (6), wherein the partition layer is made of a photosensitive resin having photosensitivity to light with a wavelength of 190 nm or more and 400 nm or less in the ultraviolet region.

Explanation of symbols

[0097] 1 ··· Input section 2 ··· Output section 3 ··· Flow path 10 ··· Substrate 20 ··· Partition layer 21 ··· Floating portion 22 ··· Bonding region 30 ··· Cover material 51 ··· Photosensitive resin layer 52 ··· Exposed region 53 ··· Unexposed region

Claims

1. A substrate, a partition layer provided on the substrate and defining a flow path, and a lid member provided on a surface of the partition layer opposite to the surface in contact with the substrate, in a microchannel chip, wherein the partition layer has a floating portion which is a region on the lid member side and is not in contact with the lid member, and when viewed in the thickness direction of the partition layer, a ratio of a width of the floating portion to a width of the partition layer sandwiched by the flow path is 0% or more and 62% or less. A microchannel chip.

2. The lid member has a complex elastic modulus measured by a micro-indentation test of 1.7 MPa or more and 21 MPa or less. The microchannel chip according to Claim 1.

3. The lid member contains at least one of polydimethylsiloxane, silicone rubber, polyurethane, and polyvinyl chloride. The microchannel chip according to Claim 2.

4. When viewed in the thickness direction of the partition layer, a ratio of a width of the floating portion to a width of the partition layer sandwiched by the flow path is 41% or less. The microchannel chip according to Claim 1.

5. The lid member has a complex elastic modulus measured by a micro-indentation test of 1.7 MPa or more and 4600 MPa or less. The microchannel chip according to Claim 4.

6. The lid member contains at least one of polydimethylsiloxane, silicone rubber, polyurethane, polyvinyl chloride, polymethyl methacrylate (PMMA), polycarbonate (PC), polystyrene (PS), polypropylene (PP), cycloolefin polymer (COP), cycloolefin copolymer (COC), and polyethylene terephthalate (PET). The microchannel chip according to Claim 5.

7. The partition layer is made of a photosensitive resin having photosensitivity to light with a wavelength of 190 nm or more and 400 nm or less in the ultraviolet light region. The microchannel chip according to any one of Claims 1 to 6.

Images