JP2008056498A - Method of manufacturing micro-chemical chip - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem that the surface unevenness of a weight is transferred on the surface of glass to be laminated to degrade optical characteristics when the melting temperature is raised to prevent the occurrence of unfused parts over the whole surface to be laminated when a plurality of glass plates are joined by thermal fusing in a state of applying the weight. <P>SOLUTION: In the manufacture of glass joined body by joining two glass plates by thermal fusion, a glass plate surface-smoothened to be ≤2.5 nm surface undulation (ωa) in 0-5 nm measuring wavelength range and ≤3 μm difference of the in-plane plate thickness by precision polishing is used. The thermal fusion temperature to join the glass plates is a temperature equal to or above the glass transition point and below the yielding point. The thermal fusion is preferably carried out at the temperature not higher than a temperature when the viscosity (η)reaches logη=12.0. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a method for manufacturing a microchemical chip, and more particularly to a method for manufacturing a microchemical chip, which is a bonded body of glass plates, by thermal fusion bonding of the glass plates.

From the viewpoint of performing a chemical reaction at high speed and from the viewpoint of performing a chemical reaction with a very small amount of sample, a microchemical technique for introducing a sample into a microchannel and performing a chemical reaction has attracted attention. That is, researches are being actively conducted in which chemical reactions such as mixing, reaction, separation, extraction, and detection of solutes contained in a sample solution are carried out in a microchannel provided in a microchemical chip.

A microchemical chip is formed by joining a glass substrate provided with holes for sample liquid injection and discharge and a glass substrate with grooves so that the holes and grooves are connected to each other. It has a path inside. A method of manufacturing this microchemical chip by joining two glass substrates by thermal fusion is disclosed in Japanese Patent Application Laid-Open No. 2004-125476.

JP 2004-125476 A

The method of joining the glass plates by heat fusion is usually performed by maintaining the glass at a temperature equal to or higher than the yield point of the glass for a certain period of time while the glass is bonded. At this time, a method is adopted in which a pressure is applied to the bonded surface of the glass while applying a load from the outside. When glass is bonded by thermal fusion while maintaining the temperature above the yield point for a certain time, the glass surface has viscoelastic properties, and the glass plate surface is deformed although it is a small amount.

When applying a load in order to pressurize the bonding surface from the outside at the time of thermal fusion (for example, when a bonding surface is pressurized by placing a weight on a glass plate to be fused), when the fusion temperature is high, The surface unevenness pattern of the weight is transferred to the surface (outer surface) of the glass plate constituting the microchemical chip, and the minute unevenness causes scattering of light incident on the glass plate. Therefore, there is a problem that a microchemical chip with good translucency cannot be obtained. That is, when manufacturing by bonding glass plates by heat fusion, it was difficult to manufacture a microchemical chip having the characteristics of good translucency and light straightness (small haze ratio for incident light). .

In addition, when a glass plate is heated to a temperature at or above the yield point of the glass, there is a problem that the glass is likely to warp during the cooling process, and the microchemical chip is placed in the optical path due to deformation of the glass plate constituting the microchemical chip. There has been a problem in use that accurate positioning is not easy.

Japanese Patent Application Laid-Open No. 2004-125476 discloses a method of joining glass plates by heat fusion. In order to eliminate the above-mentioned problems, as a pretreatment for bonding glass plates by thermal fusion, the surface of the glass plate can be treated with an alkaline aqueous solution and fusion-bonded at a lower temperature than the internal glass (fusion layer). And heat-sealing at a temperature lower than the softening point of the glass. That is, a method is described in which a glass whose surface has been modified by alkali treatment is heated and fused to a temperature range in which the glass viscosity η (poise) is log η = 10.5 to 12.5.

The temperature range in which the viscosity of the glass corresponds to the above range is a temperature lower than the softening point (log η = 7.6 poise) of the glass and higher than the annealing point (log η = 13) of the glass. That is, it is described that the glass is heated and fused-bonded within a temperature range from the annealing point to the softening point (approximately equivalent to the transition point to the yield point). This temperature range includes the deformation temperature range of glass (Deformation Temperature: log η = 11-12: see Glass Engineering Handbook, published by Asakura Shoten, first published in 1963). The phenomenon of glass lump is distorted by the polished surface of the cube. It is the starting temperature.

However, whether or not a fusion layer can be formed on the glass surface largely depends on the component composition of the glass, and is not necessarily applicable to glass having various component compositions.

In order to solve the above-mentioned problems, the present inventor diligently studied a method capable of bonding at a fusion temperature lower than the yield point of the glass regardless of the composition of the glass. As a result, in order to reduce the temperature at which fusion can be performed, the inventors have found that the smoothness of the bonded surface of the glass is important and have come to the present invention.

The first aspect of the present invention is a method for manufacturing a microchemical chip in which a glass plate is bonded by thermal fusion and has a built-in microchannel, and the surface undulation (ωa value) in the measurement wavelength range of 0 to 5 nm is 2. A glass plate smoothed to 5 nm and having an in-plane thickness difference of 3 μm or less is heat-sealed.

The material of the glass plate used in the present invention is not particularly limited. However, considering the microchemical chip used for analysis of ecological samples such as protein, blood, DNA, and environmental analysis, it has chemical durability (acid resistance and alkali resistance are High) glass is preferable, and examples thereof include silicate glass such as borosilicate glass, aluminoborosilicate glass, aluminosilicate glass, alkali-free glass used in TFT liquid crystal display elements, quartz glass, and soda lime silicate glass.

If necessary, the glass plate is lapped (grinded) with the alumina fixed abrasive or diamond fixed abrasive to a predetermined thickness, and then the lapped surface is polished (hereinafter sometimes referred to as precision polishing). Good. The glass plate according to the present invention is required to have a waviness value (ωa) of 2.5 nm or less and an in-plane plate thickness difference of 3 μm or less by means of precision polishing. By smoothing the waviness value to 2.5 nm or less, it becomes possible to lower the temperature at which the bonded surfaces of the glass plates are bonded to the entire surface without producing unfused portions to the glass transition point.

Further, smoothing the waviness value to less than 0.2 nm requires a long polishing time, and even if the waviness is reduced to 0.2 nm or less, a further good effect cannot be obtained. Therefore, it is preferable to smooth the bonded surface of the glass plate by polishing in the range of 0.2 to 2.5 nm, preferably in the range of 0.2 to 2.0 nm.

In addition, it is necessary to smooth the in-plane thickness difference (thickness difference) of the glass plate to 3 μm or less. By setting the difference in plate thickness to 3 μm or less, it becomes possible to lower the temperature at which the bonding surfaces of the glass plates are bonded to the entire surface without producing unfused portions to the glass transition point. Thereby, the magnitude | size of the curvature of a glass plate can be suppressed. Even if the glass plate thickness difference is polished to less than 0.5 μm, a further good effect cannot be obtained. Therefore, it is preferable to smooth the surface in the range of 0.5 to 3 μm in consideration of the polishing processing efficiency.

The smoothing of the glass plate can be performed by a known method using a double-side polishing machine using a polishing liquid and a polishing pad containing polishing grains of cerium oxide or alumina. Of these, cerium oxide abrasive grains are preferred. Further, it is preferable to further improve the smooth surface by multi-stage polishing using coarse grains of cerium oxide and finer grains. In the multistage polishing in which the polishing abrasive grains are changed, the glass surface can be smoothed by further reliably reducing the compressive strain on the glass surface by the polishing pressure.

A second aspect of the present invention is characterized in that, in the first aspect, the thermal fusion is a thermal fusion that heats the glass to a transition point or more and less than a yield point.

By making it less than the yield point of glass characterized by the phenomenon of deformation due to its own weight (log η = temperature corresponding to about 10.4), it receives a load (weight) for press-contacting the bonded surface, It is suppressed that the smoothness of the glass plate surface (surface opposite to the bonding surface) of the microchemical chip is impaired due to transfer of dust, weight surface shape, and the like. Moreover, it can suppress that curvature generate | occur | produces in a glass plate.

At temperatures above the glass transition point, the glass gradually loses its rigidity and appears viscoelastic. The glass transition point (temperature at which the viscosity η of the glass is log η = 13.3) is slightly lower than the annealing point (temperature at which the log η = 13.0), and when maintained at that temperature, the glass is physically It is explained that the characteristic changes with time and approaches a certain physical property value. It is close to the annealing point (log η = 13.0) defined as the temperature at which the internal strain of the glass can be removed in about 15 minutes.

In the present invention, since the bonding surface of the glass plate is smoothed by polishing until the waviness value is 2.5 nm or less, the bonding temperature can be lowered to the glass transition point at which the viscoelastic properties of the glass start to occur. . In addition, the bonding temperature for heat-sealing is performed at a temperature lower than the yield point of the glass plate, so that the glass plate to be bonded can be bonded without lowering the translucency and suppressing the warpage of the glass plate. .

When there is undulation (so-called short range undulation) in the measurement wavelength range of 0 to 5 mm on the surface of the glass plate, there is a minute gap between the two glass plates that are bonded together, and there is sufficient glass flow to fill this gap. • Requires deformation, which requires heating to a high temperature above the yield point. In the present invention, since the waviness of the glass plate on the bonding surface is smoothed to 2.5 nm or less, the glass fusing temperature for bonding on the entire surface of the bonding surface is lowered to the glass transition point. Can do.

A third aspect of the present invention is characterized in that, in the second aspect of the present invention, the temperature for joining by thermal fusion is not lower than the glass transition point and the glass viscosity η is not more than log η = 12.0.

By setting the temperature at which heat fusion is performed to a temperature at which the viscosity of the glass becomes log η = 12.0 or less, it is possible to more reliably prevent the deterioration of the optical properties of the glass plate. Further, the warp and deformation of the glass can be reliably prevented. By performing heat fusion while pressing the bonded surface from the outside, it is possible to reliably perform fusion bonding over the entire bonded surface without causing an unfused portion. In addition, the time required for heat fusion can be shortened. The heat fusion of the glass plates can be performed by stacking a plurality of glass plates to be bonded together.

Between each pair of glass plates, a heat-resistant ceramic plate (for example, an alumina polishing plate) whose surface is polished smoothly and has a higher heat deformation temperature than the glass plate is interposed, and the glass plates are attached by weighting the ceramic plates. Press the mating surfaces together.

According to the present invention, since the undulation of the bonding surface of the glass plate and the in-plane thickness difference of the glass plate are set to a predetermined value or less, the bonding temperature can be lowered to the glass transition point and the entire bonding surface can be fusion bonded. .

Further, by performing heat fusion at a temperature not lower than the glass transition point and lower than the yield point, the glass plates can be joined without causing warpage. Further, it is possible to prevent the deterioration of the optical characteristics of the glass plate caused by the contact during the fusion of foreign matter, dirt, weighted body, and the like.
Furthermore, by making the heat fusion temperature equal to or lower than the temperature at which the viscosity η of the glass becomes log η = 12.0, it is possible to more reliably suppress the deterioration of the optical properties and warpage of the microchemical chip after bonding. it can

Embodiments of a method for producing a microchemical chip of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of a microchemical chip obtained by carrying out the present invention. FIG. 1A is an exploded perspective view of an embodiment of the microchemical chip of the present invention. FIG. 1B is a plan view of the microchemical chip. FIG. 1C is a cross-sectional view taken along line A-A ′ in FIG. FIG. 1D is a cross-sectional view taken along line B-B ′ in FIG.

In FIG. 1, a microchemical chip 100 of the present invention has a width of 0.3 ± 0.2 mm and a depth of 0.1 ± 0.00 mm with both ends bifurcated into a joint surface 8 to be joined by thermal fusion. A grooved glass substrate 2 (base plate) on which a groove 1 having a substantially rectangular or semicircular shape having a cross section of 05 mm is formed, and a second glass substrate 4 (cover plate) bonded to the bonding surface of the grooved glass substrate 2 Prepare. The second glass substrate 4 has a through hole 3 for sample injection / discharge at a position corresponding to the groove 1 (FIG. 1A). In the groove 1, these two glass substrates are bonded together by thermal fusion to form a micro flow channel 5 of the microchemical chip 100.

The microchannel 5 of the microchemical chip 100 is formed in an appropriate size and shape, and a sample solution is injected from the through-hole 3 (which serves as an inlet and outlet for the sample), and electrophoresis, photothermal conversion spectroscopic analysis Qualitative analysis, quantitative analysis, mixing, reaction, extraction, separation, and the like of a sample in a liquid are performed in a microchannel by a known method such as a method (thermal lens spectroscopic analysis) or a fluorescence analysis method.

As a material for the grooved glass substrate 2 and the second glass substrate 4, a glass having chemical durability is preferable in consideration of microchemical chips used for analysis of ecological samples such as proteins, blood, and DNA and environmental analysis. The composition of the glass such as borosilicate glass, aluminoborosilicate glass, alkali-free glass, quartz glass, soda-lime silicate glass is not limited. For example, Pyrex (registered trademark) glass, Tempax glass, NA30 glass and the like can be exemplified.

In order to produce a microchemical chip from a commercially available glass plate, the glass plate is thinned to a predetermined thickness by lapping (grinding) prior to polishing and smoothing the surface of the glass plate. That is, in FIG. 2, the surfaces of the grooved glass substrate 2 and the second glass substrate 4 are smoothed by precision polishing, but are cut into a predetermined shape from a glass base plate and fixed to a predetermined thickness of alumina. The main surface is usually lapped (grinded) with grains or diamond fixed abrasive grains, and then the lapped surface is polished (hereinafter sometimes referred to as precision polishing). Precision polishing of a glass plate is a known method of moving the glass surface using a polishing liquid and a polishing pad in which free abrasive grains such as cerium oxide and aluminum oxide are suspended, and pressing the abrasive grains against the glass surface with the polishing pad. Can be performed. For example, a Hoffman double-side polishing machine can be used as the polishing machine.

Distortion (compression residual strain) is generated on the glass surface by a lapping process in which the glass surface is pressed and ground with hard abrasive grains. Precision polishing has the effect of smoothing the glass surface and reducing this distortion. A polishing liquid in which abrasive grains of cerium oxide having a hardness higher than that of the glass to be polished are suspended is supplied to the glass surface, and the glass surface is moved in the polishing process by moving the glass surface while pressing the abrasive grains against the glass surface. As the material is ground and disappears one after another, it is pressed by the abrasive grains and a compressive stress is formed toward the inside of the glass. The formed compressive strain disappears by polishing one after another, but the residual stress is considered to be smaller than that immediately after lapping.

Precise polishing is preferably performed by multi-stage polishing, that is, pre-stage polishing using abrasive grains having a relatively large particle diameter of cerium oxide and post-stage polishing having a smaller particle diameter. This is because polishing using a small particle size abrasive grain does not cause residual strain on the glass surface, or the size of the strain becomes smaller. Thereby, when the groove is formed by chemical etching, an etch pit is not generated, and the groove having a smooth etching wall surface can be finished.

By pre-polishing using cerium oxide abrasive grains and a polishing pad (polishing cloth), the surface of the glass plate is smoothed together with removal of scratches, foreign matter, distortion, and the like, and then smoothing is further improved by post-polishing. After the subsequent polishing of cerium oxide, precision polishing using a colloidal silica abrasive may be added.

Pre-stage precision polishing with cerium oxide abrasive grains is performed by, for example, suspending abrasive grains having an average grain diameter D50 of 0.8 to 1.2 μm in water to form a polishing liquid, and a glass plate with a urethane polishing pad. The polishing time is 40 to 70 minutes at a polishing pressure of ˜100 gf / cm ² . Subsequent to the preceding polishing, the subsequent precision polishing with cerium oxide abrasive grains having a smaller particle diameter is 25 at an abrasive pressure of 40 to 90 gf / cm ² with an average grain diameter D50 of 0.2 to 1.0 μm. A polishing time of ~ 45 minutes is preferable. By multi-stage polishing in which the abrasive grain size and polishing pressure are changed, the polishing time can be shortened and the smoothness can be increased.

As the polishing pad, precision polishing can be performed with a Hoffman double-side polishing machine using a commercially available polishing pad, for example, a polishing pad such as 7713S manufactured by Kanebo or SF22S manufactured by Fujibow.

The glass plate polishing allowance is preferably 15 to 25 μm on one side of the glass. By setting the thickness to 15 μm or more, cracks and surface residual strain generated in the lapping process can be almost eliminated. Polishing exceeding 25 μm is not preferable because the slow strain effect is not further increased and the polishing time is increased. By the above-mentioned polishing, the smoothness after polishing of the surface of the glass plate is adjusted to 2.5 nm or less with a waviness value ωa (measurement wavelength range 0 to 5 mm), and the in-plane thickness difference of the glass plate is set to 3 μm or less.

In place of or in addition to the subsequent precision polishing, precision polishing using colloidal silica abrasive grains and a polishing pad is preferably performed as the final polishing. The average grain size D50 of the abrasive grains is preferably 0.1 μm or less, and more preferably 0.04 μm or more.

In order to more surely remove residual strain on the precisely polished glass surface, it is preferable to perform strain relief annealing (heat treatment). By performing the annealing treatment, the generation of fine etch pits can be more reliably eliminated in the groove forming step by the subsequent etching.

FIG. 2 is a diagram for explaining a method of manufacturing a microchemical chip. The second glass substrate 6 (cover plate) is smoothed by precision polishing so that the in-plane thickness difference is 3 μm or less and the undulation on the glass surface is 2.5 nm or less. A through hole 3 is formed (step a in FIG. 2). This may be reversed.

Also for the glass plate 7 to be the base plate (grooved glass substrate 2), the in-plane thickness difference is smoothed to 3 μm or less and the surface waviness is smoothed to 2.5 nm or less by precision polishing. On one surface of the glass, a metal masking film 11 made of a laminated film of a chromium film and a gold film is coated by a sputtering thin film forming method, and a photoresist layer 12 is further applied. The portion of the photoresist layer not masked by the masking pattern 13 is dissolved and removed by irradiation with ultraviolet light, and the exposed metal masking film is removed with an aqueous solution of ceric ammonium nitrate. The exposed surface of the base plate is etched with an etchant containing hydrofluoric acid. Etching is performed using, for example, warmed or room temperature 49% hydrofluoric acid for an etching time of about 2 to 5 minutes. Thus, the grooved glass substrate 2 in which the groove 1 having a substantially semicircular cross section is formed on the glass main surface is obtained. The base plate and the cover plate are bonded and bonded together by thermal fusion to obtain a microchemical chip in which an injection hole, a micro flow path, and a discharge hole communicate with each other.

FIG. 3 is a view for explaining an embodiment of a joining method by heat fusion according to the present invention. A method of thermally fusing two sets of microchemical chips simultaneously is shown. A set of base plate 2 and cover plate 4 are placed on an alumina base 9 having a well-polished surface, and an alumina weight (weight) 10 having a well-polished surface is placed thereon. Further, another set of base plate 2 and cover plate 4 is placed on top of each other, and finally, a weight 10 made of alumina is placed thereon. The joint surface is pressed (pressed contact) with a load 10 made of alumina. The stacked layers are put in an electric furnace and heated to a temperature equal to or higher than the transition point for bonding. The number of sets to be superimposed is not particularly limited, but is preferably about 1 to 10 sets. The weight is preferably 1 to 50 g / cm ² .

If the bonding temperature at which the two glass substrates are heat-sealed at the bonding surface is high, the glass surface different from the bonding surface is pressed with a load of 10 or 10, so that fine irregularities on the surface of the load 10 are present. Transferred to the glass substrate surface. When such a concavo-convex pattern is formed on the glass surface, the light incident on the glass surface generates a scattering component (the haze ratio of the glass plate increases), and linear light enters the microchannel of the microchemical chip. Inconvenience disappears.

By performing bonding by thermal fusion at a temperature not lower than the glass transition point and lower than the yield point, it is possible to prevent deterioration of the optical properties of the glass surface (increase in haze ratio value). From the viewpoint of surely suppressing an increase in the haze ratio due to transfer, it is preferable to perform heat fusion at a temperature equal to or higher than the transition point and below a temperature at which the viscosity η of the glass becomes logη = 12.0. Hereinafter, the present invention will be described in detail with reference to examples.

Wrapping (grinding) a plurality of Schott Tempax (registered trademark) glass plates (thickness 1.1 mm: transition point 562 ° C., log η = 13.3) having a length of 70 mm and a width of 30 mm using alumina as abrasive grains. ) To a thickness of about 0.75 mm. Using this glass plate as a precision polish, a Hoffman-type double-side polishing is performed using a polishing liquid containing cerium oxide free abrasive grains manufactured by Mitsui Mining & Smelting Co., Ltd., whose average grain diameter D50 is 1.2 μm, and a polishing pad LP66 manufactured by Rhodes. Polishing was performed with an apparatus until the thickness became 0.71 mm (removal allowance per one glass surface). The polishing pressure was adjusted to 80 gf / cm ² . Polishing until the glass plate thickness becomes 0.70 mm using a polishing solution containing cerium oxide abrasive grains having an average particle diameter D50 of 0.4 μm and a polishing pad 7713S manufactured by Kanebo Co., Ltd. 5 μm). The surface of the glass plate smoothed by precision polishing in this way was measured with an OPTIFLAT measuring device (manufactured by PHASESHIFT Technology) under the measurement wavelength range of 0 to 5 mm, and the swell value ωa value was 2.5 nm. The in-plane thickness difference obtained by measuring 10 points with a micrometer was 3.0 μm.

About one of the obtained glass plates, the surface of the glass was chemically etched with 49% hydrofluoric acid using a laminated sputtered film of chromium film and gold film as a masking film, and a groove with a semi-circular cross section (maximum width) A glass substrate 2 with a groove (base plate) was formed by forming 300 μm and a maximum depth of 100 μm. A through-hole having a hole diameter of 300 μm serving as an injection hole and a discharge hole was opened at a predetermined position on another glass plate, and used as a cover plate.

The two glass plates are bonded together, and an alumina load is applied as shown in FIG. 3 (applied pressure 20 g / cm ² ), and the temperature is maintained at 562 ° C., which is the glass transition point, in the electric furnace for 5 hours. Then, it was slowly cooled and taken out of the electric furnace. As shown in Table 1, the microchemical chip comprising the obtained glass plate bonded body was bonded to the entire bonded surface by thermal fusion, and no unfused portion was found. Moreover, the cloudiness resulting from the transcription | transfer of the surface of the weight made from an alumina was not recognized by the external appearance on the glass plate surface of this sample. When the haze ratio of visible light of this sample was measured, it was 0.1%.

A sample of a microchemical chip was prepared in the same manner as in Example 1 except that the polishing time was increased to improve the smoothness of the polished surface and the heat fusion temperature was set to 610 ° C. As shown in Table 1, this sample was bonded by heat fusion over the entire bonding surface, and no unfused portion was found. Also, no transfer of alumina weight was observed.

A sample of a microchemical chip was produced in the same manner as in Example 1, except that the heat fusion temperature was 610 ° C. As shown in Table 1, this sample was bonded by heat fusion over the entire bonding surface, and no unfused portion was found. Almost no transfer of alumina weight was observed.

A sample of a microchemical chip was produced in the same manner as in Example 1 except that the fusion temperature was set to 630 ° C. (temperature at which log η = 11.5), which was about 70 higher than the transition point. As shown in Table 1, this sample was bonded by thermal fusion over the entire bonding surface. Although the haze rate slightly increased, almost no transfer of alumina weight was observed.

Comparative Example 1
A sample of a microchemical chip was produced in the same manner as in Example 1 except that the fusion temperature was fused at a yield point of 652 ° C. As shown in Table 1, this sample was bonded over the entire bonding surface, but clouding of glass due to transfer was observed.

Comparative Example 2
A microchemical chip sample was prepared in the same manner as in Example 1 except that the fusing temperature was 550 ° C. (a temperature 8 ° C. lower than the transition point). An unfused portion was generated on a part of the bonding surface.

Comparative Example 3
A microchemical chip sample was prepared in the same manner as in Example 1 except that the polishing time for precision polishing was shortened. The bonded surface of this glass plate had a large waviness value of 4.0 nm and an in-plane thickness difference of 5.5 μm. This sample was fused at a glass transition point of 562 ° C., but unfused portions were formed at the peripheral and central portions of the glass, resulting in insufficient bonding.

Comparative Example 4
A sample of a microchemical chip was produced in the same manner as in Comparative Example 3 except that the heat fusion temperature was 610 ° C. As shown in Table 1, this sample could not be bonded by heat fusion over the entire bonding surface, and unbonded occurred at the peripheral and central portions of the glass.

Comparative Example 5
A sample of a microchemical chip was produced in the same manner as in Comparative Example 3 except that the heat fusion temperature was 630 ° C. In this sample, as shown in Table 1, an unfused portion was found on a part of the bonded surface.

Comparative Example 6
A sample of the microchemical chip was produced in the same manner as in Comparative Example 3 except that the heat fusion temperature was 652 ° C. (corresponding to the yield point). In this sample, as shown in Table 1, an unfused portion was recognized on a part of the bonded surface, and uneven transfer onto the glass surface was also recognized. The haze rate increased to 0.6%.

As described above, the undulation value ωa of the measurement wavelength range of 0 to 5 mm of the glass plate to be bonded is 2.5 nm or less, and the in-plane plate thickness (wall thickness) difference is 3 μm or less. It can be seen that the fusing temperature required to bond across can be lowered to the glass transition point.

FIG. 1 is a diagram illustrating a schematic configuration of an embodiment of a microchemical chip of the present invention. FIG. 2 is a process diagram for producing the microchemical chip of the present invention. FIG. 3 is a view for explaining an embodiment of the heat fusion bonding of the present invention.

Explanation of symbols

1: Groove 2: Glass substrate with groove (base plate)
3: Through hole (injection hole, discharge hole)
4: One glass substrate (cover plate)
5: Micro flow path 6: Glass plate 7: Glass plate 8: Joining surface 9: Alumina base 10: Alumina weight (weight)
11: Metal masking film 12: Photoresist layer 13: Masking pattern 100: Micro chemical chip

Claims (3)

In a method for producing a microchemical chip having a micro flow path by joining glass plates by heat fusion, the surface waviness (ωa value) in the measurement wavelength range of 0 to 5 mm is 2.5 nm or less by polishing, and the in-plane thickness difference A method for producing a microchemical chip, comprising thermally fusing a glass plate smoothed to 3 μm or less. 2. The method of manufacturing a microchemical chip according to claim 1, wherein the temperature of the thermal fusion is set to be not lower than the glass transition point and lower than the yield point. 3. The method for producing a microchemical chip according to claim 2, wherein the temperature of the thermal fusion is not more than a temperature at which the value of the viscosity η of the glass becomes log η = 12.0.

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