JP2008170349A - Method of manufacturing glass microchip substrate with electrode - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a simple jointing method that does not cause exfoliation due to ultrasonic cleaning and cleaning due to high-pressure air, without having to seal a fine flow channel by an adhesive, by superimposing a glass substrate having an electrode on its surface and a glass substrate, which has a flat surface that is brought into close contact with the glass substrate, and that has a fine flow channel overlapped on one another. <P>SOLUTION: A method of manufacturing a glass microchip with an electrode includes a step of superimposing one glass substrate having the fine flow channel formed to its surface on another glass substrate having an electrode formed on its surface so that the electrode and the fine flow channel are opposed to each other; a step of making a UV-curing adhesive penetrate the gap between one glass substrate and another glass substrate; and a step of making the UV-curing adhesive that has infiltrated the fine flow channel an UV-light irradiation step remove. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

In the present invention, a micro flow channel is formed on the surface of one glass substrate, an electrode is formed on the other glass substrate, and two glass substrates are joined to produce a glass microchip (joining method) )
It is about.

  Conventional microsystem chip bonding methods include a method in which an aqueous solution of hydrofluoric acid or anhydrous silicic acid is dropped onto one glass substrate, and the other glass substrate is bonded to each other by applying a load for a long time, such as NaOH. It is known that both glass substrates are washed with alkali and bonded by applying light pressure, and that both glass substrate surfaces are activated by energy beam irradiation and bonded with high vacuum. In either method, the glass substrate is heated to near the glass transition point Tg.

As a conventional microchip manufacturing method, “in the microchemical system chip manufacturing method constituted by at least two glass substrates to be bonded to each other, when the glass viscosity of the glass substrate is represented by η, A method for producing a chemical chip for a microsystem, wherein the glass substrate is heat-sealed at a temperature at which log η is 10.5 to 12.5 ”is known. (See Patent Document 1)
Further, “a method of manufacturing a glass substrate microchip by joining two glass substrates having a micro-channel formed in a surface of at least one glass substrate, and having a low vacuum of 10 −4 Torr or more There is known a manufacturing method of a glass substrate microchip characterized by press-pressing at a heating temperature equal to or lower than a softening point of a glass substrate in a reduced pressure environment, and closely bonding the glass substrate. (See Patent Document 2)
JP 2004-125476 A JP 2004-210592 A

  However, in the conventional method for joining chips for a microsystem, the glass substrates are not joined to each other, and the glass substrates are not fused together, and the degree of joining between the glass substrates is not sufficient. In addition, when a material such as an electrode (gold electrode) such as an electrode is present on the substrate, the cell is often damaged due to the difference in expansion coefficient between the glass and the material (gold electrode), which reduces the yield. I was invited.

  An object (object) of the present invention is to superimpose a substrate (microchip body) having an electrode on a surface thereof and a substrate (microchip lid substrate) serving as a lid having a flat surface in close contact with the microchip body and a fine channel. In addition, it is an object of the present invention to provide a simple and simple joining method and a microchip that can be manufactured by this method, in which separation is not caused by ultrasonic cleaning and cleaning with high-pressure air without blocking fine channels.

  In addition, in the conventional bonding method by fusion, the cell may be damaged due to the difference in expansion coefficient between the glass substrate and a different substance (gold electrode) on the substrate, unlike the bonding between the materials of only the glass substrate. Therefore, the present invention is to provide a simple and simple bonding method with improved yield and a microchip that can be manufactured by this method.

  In order to solve the above-mentioned problems, the method for producing a glass microchip substrate with an electrode according to the present invention comprises: one glass substrate having a fine flow path formed on the surface; and the other glass substrate having an electrode formed on the surface. A step of aligning and overlapping the electrode and the fine channel so as to face each other, a step of injecting a UV curable adhesive between the one glass substrate and the other glass substrate, The method includes a step of removing the invading UV curable adhesive and a step of irradiating UV light. (Claim 1)

In addition, before the step of removing the UV curable adhesive that has entered the fine flow path, pressure is applied on the other glass substrate to bring the adhesive between the two glass substrates to a predetermined height. And a step of removing excess adhesive. (Claim 2)
The process is performed in an environment filled with nitrogen. (Claim 3)

In addition, when the two glass substrates are joined, the height of the fine channel from the surface of the other glass substrate is 7 μm or more. (Claim 4)
Further, the fine flow path is penetrated by a side surface of the one glass substrate. (Claim 5)

In addition, the electrodes are exposed on both side surfaces of the fine channel. (Claim 6)
Further, a plurality of the fine flow paths are formed on one glass substrate. (Claim 7)

The thickness of the one glass substrate is less than 0.2 mm. (Claim 8)
Moreover, the glass microchip board | substrate with an electrode of this invention is manufactured with the manufacturing method of the glass microchip board | substrate with an electrode in any one of Claims 1-8. (Claim 9)

According to the method for manufacturing a glass microchip substrate with an electrode according to the present invention described in claims 1 to 8, two glass substrates can be bonded in a small number of steps without using a large-scale apparatus. Since it is not available, it can contribute to the promotion of research and development by being able to respond quickly to various patterns.
In addition, even when substances having different materials such as a substrate with electrodes are combined, it is possible to perform simple and simple bonding.

The basis of the present invention is that a microchannel groove is formed on the surface of one glass substrate, an electrode is formed on the other glass substrate, and two glass substrates are joined to produce a glass microchip. Is the method.
In the method for producing a glass microchip according to the present invention, a UV curable adhesive having a predetermined viscosity is used as an adhesive for joining two glass substrates, and the surface tension and capillary action of the adhesive are used. Thus, the adhesive is prevented from entering the flow path, and two glass substrates are tightly bonded.

  Specifically, for example, by using a UV curable adhesive having a viscosity of 6-10 mPa · s, it is possible to prevent adhesion of the adhesive into the flow path by surface tension and capillary phenomenon, and to bond the glass substrates in close contact. Features.

  Also, for example, by using a UV curable adhesive with a viscosity of 6-10 mPa · s, the height of all channels in the microchip is kept constant between the lid substrate with a fine flow path and the glass substrate with an electrode by surface tension. The glass microchip is manufactured by joining two glass substrates in a state kept simply.

  In addition, in the method for producing a glass microchip of the present invention, when the adhesive enters the flow path due to excessive poultice, the adhesive is sucked with a commercially available micropipette and a diagram pump, thereby re-cleaning and re-adhesion of the adhesive. It is characterized in that the step of the compress can be omitted.

  In addition, the method for producing a glass microchip of the present invention is characterized in that when the adhesive is cured by UV irradiation, UV irradiation is performed in a nitrogen atmosphere, and before placing the microchip before bonding in a nitrogen atmosphere, It is characterized in that two sheets of glass are joined by sufficiently replacing the inside of the flow path with nitrogen.

Next, the manufacturing method of the glass microchip of this invention is demonstrated using FIGS.
FIG. 1 is a view showing a state immediately before the start of production of the glass microchip of the present invention.
In FIG. 1, reference numeral 1 denotes one glass substrate having a fine flow channel groove (height 7 μm in the figure) formed on the surface portion, and 2 denotes the other glass substrate on which an electrode 3 is formed.
The present invention is a method for producing a glass microchip by bonding the two glass substrates.
In FIG. 1, reference numeral 4 denotes a pipette that allows an adhesive to enter between two glass substrates in order to join the two glass substrates.

FIG. 2 is a view showing a state in which the glass microchip of the present invention is manufactured and an adhesive is invaded by the pipette 4 in the state of FIG.
In FIG. 2, reference numerals 1, 2, and 3 denote one glass substrate (lid substrate), the other glass substrate, and electrodes as in FIG.
In the state of FIG. 1, when an adhesive is made to penetrate between two glass substrates with a pipette, it penetrates between the two glass substrates and into the fine channel groove formed in the glass substrate 1 by capillary action.
In this state, 5, 6 and 7 are intruded adhesives, 5 is a part necessary for bonding two glass substrates, and 6 is in a fine flow channel groove formed on one glass substrate 1. An adhesive portion invaded by capillary action, and 7 is an overflowing excessive adhesive portion.
The surface tension acts on the adhesive, and the glass substrate 1 is kept at a predetermined height with respect to the glass substrate 2.
In FIG. 2, reference numeral 8 denotes a slide glass (usually used in a microscope), and shows a state immediately before pressurizing the upper part of one glass substrate 1 through a Kim wipe 9.

FIG. 3 is a view showing a state in which excess adhesive 7 is removed after the glass microchip of the present invention is manufactured and pressed with a slide glass through a Kimwipe in the state of FIG.
In FIG. 2, reference numerals 1, 2, and 3 denote one glass substrate, the other glass substrate, and an electrode as in FIG. 1, and in this state, the adhesive is still filled (invaded) into the microchannel 11.
Moreover, in this state, since it was pressurized with the slide glass through the Kim wipe, the distance between one glass substrate and the other glass substrate is kept at a predetermined height by the surface tension.
In this state, the adhesive filling (invading) the fine flow path 11 is removed by suction with a micropipette or a diagram pump.
It should be noted that in the step of removing the adhesive by suction, only the adhesive in the fine flow path is removed by suction, and the exhaust speed (for example, 60 L / min) is reached so as to leave the adhesive between the two glass substrates. When executed at a pressure (for example, 21.3 kPa), there is a difference in the distance at the joint between the two glass substrates and the height between the surface of one glass substrate and the fine flow path, which is caused by the capillary action that occurs there. As a result, the adhesive force in the fine channel alone can be removed by suction.

FIG. 4 shows a state where the adhesive in the fine channel is removed in the state of FIG. 3 and the adhesive is cured by irradiating UV light.
In FIG. 4, 1, 2 and 3 are one glass substrate, the other glass substrate and electrodes as in FIG. 1, and 10 is an adhesive which joins the two glass substrates.
And in the example of a figure, the height of the microchannel 12 is 7 micrometers, and the height (thickness) of an adhesive agent is 2 micrometers.

FIG. 5 is a plan view of a glass microchip obtained by bonding the two glass substrates of FIG.
Reference numerals 1, 2, and 3 denote one glass substrate, the other glass substrate, and electrodes as in FIG. 1, and 12 denotes a fine flow path formed on one glass substrate.

6 is an exploded perspective view of the glass microchip in which the two glass substrates of FIG. 4 are joined, and 1, 2 and 3 are the one glass substrate, the other glass substrate and the electrode as in FIG. A 10-tooth adhesive, 12 indicates a fine channel formed on one glass substrate.
FIG. 6 shows a state in which the fine channel formed in one glass substrate penetrates on both side surfaces of one glass substrate.

Next, examples of the present invention will be described.
Examples of reagents and instruments using the glass microchip of the present invention in production are shown below.
-Reagents EXTRAN MA02 neutral (MERCK, Ltd., Japan), isopropyl alcohol, acetone and hexane (Wako, Japan), and ultrapure water were used for glass cleaning.
As the adhesive, Optoclave UT20 (Ardel, Inc., Japan) was used.
In addition, nitrogen was used during UV irradiation.
・ Equipment
A UV lamp (about 20 mW / cm2), a diagram pump, a toothpick, a zippered vinyl bag, and a luminometer were used.
In addition, said reagent and instrument are examples, and it is clear that other equivalents can be used.

The glass cleaning process performed as pre-processing of manufacture of the glass microchip of this invention described based on the said FIGS. 1-6 is demonstrated.
・ Glass cleaning process
(a) Wrap one glass substrate (1) and the other glass substrate with electrode (2) with Kimwipe.
(b) Dilute EXTRAN MA02 neutral about 30 times in a beaker, etc., and wash with ultrasound for 10 minutes.
(c) Remove both glass substrates (1,2) from Kimwipe and clean them thoroughly with ultrapure water.
(d) Wrap both glass substrates (1, 2) again with Kimwipe.
(e) Add isopropyl alcohol to a beaker or the like, put both glass substrates (1, 2) after the treatment of (d) above, and wash with ultrasonic waves for 10 minutes.
(f) After the processing of (e), both glass substrates (1, 2) are taken out and dried as they are.
(g) Acetone is added to a beaker or the like, and both glass substrates (1, 2) after the treatment of (f) are added, followed by ultrasonic cleaning for 10 minutes.
(h) Both glass substrates (1, 2) after the treatment of (g) are taken out and dried as they are with a dryer.
(i) Add hexane to a beaker, etc., put both glass substrates (1, 2) after the postponement (h) treatment, and wash with ultrasound for 10 minutes.
(j) Remove the glass from the Kimwipe, dry in an oven (about 80 ° C), and dissipate heat with a desiccator.
In the processes from (e) to (j), the same wiping is used to prevent the glass from being damaged.

Next, a detailed description will be given of the bonding process of two glass substrates in the production of the glass microchip of the present invention.
・ Adhesion process
(a) Position alignment of one glass substrate (1) and the other glass substrate with electrode (2).
(b) An adhesive is allowed to enter between two glass substrates by capillary action using a 2 μl pipette tip (4). (When taking the adhesive into a pipette, the tip of the tip may be brought into contact with the adhesive without pressing the pipette.) (See Fig. 1)
(c) Place one piece of Kimwipe (9) folded on one glass substrate (1), and then place a slide glass (8) (usually used in a microscope) and apply a certain pressure. Remove excess amount of adhesive (7). (See Figures 2 and 3)
(d) The adhesive (6) in the flow path is removed by suction with a diaphragm pump. (Pumping speed 60L / min, ultimate pressure 21.3kPa) (Fig. 4)
(e) Pour nitrogen into the flow path and place it in a vinyl bag filled with nitrogen.
(f) Use a UV lamp to irradiate about 5000 to 6000 mJ / cm2.
(g) Dry at 60 ° C. for 2 hours.
(h) Heat dissipation in the desiccator.
(i) After sonication in EtOH (10 minutes), dry at 80 ° C and dissipate heat in a desiccator.
(j) Confirm with a microscope.
The treatment in EtOH is for washing out the uncured adhesive with EtOH.

When the thickness of the one glass substrate was 0.15 mm, the target portion could be satisfactorily bonded, but when the thickness was 0.2 mm, an unbonded portion was generated along the glass ridge.
Therefore, in the production of the glass microchip of the present invention, the thickness of one glass substrate is preferably 0.2 mm.
There is no particular limitation on the thickness of the other glass substrate.

In the above description, one glass substrate is described as having one fine channel, but a plurality of fine channels are formed on one glass substrate. A plurality of microchips can be manufactured on a single glass substrate.
In that case, it is necessary to form a plurality of electrodes (pairs) on the other glass substrate corresponding to the plurality of fine flow paths.

It is a figure which shows the state just before the joining process start in manufacture of the glass microchip of this invention. It is a figure which shows the state which made the adhesive penetrate | invade with the pipette 4 in the state of FIG. 1 in manufacture of the glass microchip of this invention. It is a figure which shows the state which removed the excess adhesive agent 7, after pressurizing with a slide glass through a Kim wipe in the state of FIG. 2 in manufacture of the glass microchip of this invention. It is a figure which shows the state which removed the adhesive agent in a microchannel in the state of FIG. 3, and irradiated the UV light and hardened the adhesive agent. It is a top view of the glass microchip which joined two glass substrates of FIG. It is a disassembled perspective view of the glass-made microchip which joined the two glass substrates of FIG.

Explanation of symbols

1: One glass substrate (lid substrate)
2: Glass substrate with other electrode 3: Electrode 4: Pipettes 5, 6, 7 ;: Adhesive 8: Slide glass 9: Kimwipe 10: Adhesive (after pressurization)
11: Fine channel (during adhesive filling)
12: Fine channel (after removal of adhesive)

Claims (9)

A step of superposing one glass substrate having a fine channel formed on the surface thereof on the other glass substrate having an electrode formed on the surface so that the electrode and the fine channel face each other;
A step of allowing a UV curable adhesive to penetrate between the one glass substrate and the other glass substrate;
Removing the UV curable adhesive that has entered the fine flow path;
Irradiating with UV light;
The manufacturing method of the glass microchip board | substrate with an electrode characterized by including these. Before the step of removing the UV curable adhesive that has penetrated into the fine flow path, pressure is applied on the other glass substrate to bring the adhesive between the two glass substrates to a predetermined height, and the excess 2. The method for producing a glass microchip substrate with an electrode according to claim 1, further comprising a step of removing an adhesive. The method for producing a glass microchip substrate with an electrode according to claim 1 or 2, wherein the process is performed in an environment filled with nitrogen. 4. The electrode according to claim 1, wherein, when the two glass substrates are joined, a height of the fine channel from the surface of the other glass substrate is 7 μm or more. 5. Of manufacturing a glass microchip substrate with glass. The method for producing a glass microchip substrate with an electrode according to any one of claims 1 to 4, wherein the fine channel passes through a side surface of the one glass substrate. The method for producing a glass microchip substrate with an electrode according to any one of claims 1 to 5, wherein the electrodes are exposed on both side surfaces of the fine channel. The method for producing a glass microchip substrate with an electrode according to any one of claims 1 to 6, wherein a plurality of the fine flow paths are formed on one glass substrate. The thickness of said one glass substrate is less than 0.2 mm, The manufacturing method of the glass-made microchip board | substrate with an electrode of any one of Claims 1-7 characterized by the above-mentioned. The glass microchip board | substrate with an electrode manufactured with the manufacturing method of the glass microchip board | substrate with an electrode in any one of the said Claims 1-8.

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