JP2003306351A - Structure of anode junction and method for anode junction - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily and definitely perform an anode junction of a glass substrate each on both sides of a silicon substrate in a small chemical reactor provided with an anode junction structure. <P>SOLUTION: A first glass substrate 24, a silicon substrate 21, a second glass substrate 28 and an anode plate 35 connected with an anode of a DC power supply 32 via a switch 34 are mounted in this order on a cathode plate 33 connected with a cathode of the DC power supply 32. In this case, a glass layer 30 is provided on an upper surface periphery of the substrate 21, and a metal layer 31 comprising aluminum or the like is provided on a lower surface periphery of the substrate 28. When anodizing treatment is performed, the anode junction of the substrate 24 is performed on the lower surface of the substrate 21, and the anode junction of the layer 31 under the substrate 28 is simultaneously performed on the upper surface of the layer 30 disposed on the substrate 21. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anodic bonding structure and an anodic bonding method.

[0002]

2. Description of the Related Art For example, in the technical field of chemical reaction, there is known a chemical reaction device for producing a desired fluid substance by a chemical reaction (catalytic reaction) of a fluidized mixed substance by a catalyst provided in a channel. Has been. Some of such conventional chemical reaction devices have a flow path of micron order or millimeter order formed on a silicon substrate by using a fine processing technology accumulated in a semiconductor manufacturing technology such as a semiconductor integrated circuit.

FIG. 9 is a transmission plan view of an example of such a conventional small-sized chemical reaction apparatus, and FIG. 10 is a sectional view taken along the line BB. This small chemical reactor comprises a small silicon substrate 1. A fine meandering channel 2 is formed on one surface of a silicon substrate 1 by using a fine processing technique accumulated in a semiconductor manufacturing technique. On the inner wall surface of the flow path 2, for example, a reaction catalyst layer 3 for performing a chemical reaction is provided.

A first glass substrate 4 is bonded to one surface of the silicon substrate 1. An inflow port 5 and an outflow port 6 are provided at predetermined two locations corresponding to both ends of the flow path 2 of the first glass substrate 4.
Is provided. On the other surface of the silicon substrate 1, the channel 2
A thin film heater 7 meandering is provided corresponding to the above. The thin film heater 7 supplies a predetermined amount of heat energy to the reaction catalyst layer 3 in the flow path 2 during the chemical reaction when the chemical reaction (catalytic reaction) in the small chemical reaction device involves an endothermic reaction under a predetermined thermal condition. belongs to.

To the other surface of the silicon substrate 1, a peripheral portion of a second glass substrate 8 having a recess 9 formed in the central portion of the one surface (a region corresponding to the thin film heater 7) by spot facing is joined. The second glass substrate 8 serves not only to protect the thin film heater 7 but also to prevent thermal diffusion of the thin film heater 7 and improve thermal efficiency.

Next, an example of use of the small-sized chemical reaction device having the above structure will be described. For example, in recent years, in a fuel cell system using a fuel reforming type fuel cell, which has been remarkably researched and developed for practical use, it was obtained by evaporating an aqueous methanol solution using the small chemical reaction device having the above-mentioned configuration. It may be configured to generate hydrogen from the fuel gas for power generation (CH ₃ OH + H ₂ O) and supply it to the fuel cell.

That is, in a state where the inside of the flow path 2 is heated to a predetermined temperature by the heat generation of the thin film heater 7,
When the fuel gas for power generation (CH ₃ OH + H ₂ O) is supplied into the flow path 2 through the inflow port 5, an endothermic reaction is caused by the reaction catalyst layer 3 in the flow path 2, and hydrogen and by-products are generated. Carbon dioxide is generated. Then, if carbon dioxide is separated and removed from hydrogen in the product, only hydrogen can be generated, and this can be supplied to the fuel cell to generate power.

Next, an example of a method of manufacturing the small-sized chemical reaction device having the above structure will be described. First, as shown in FIG. 11, on the cathode plate 12 connected to the cathode of the DC power supply 11,
The first glass substrate 4 having the inflow port 5 and the outflow port 6 is positioned and placed. Next, the silicon substrate 1 is aligned and placed on the first glass substrate 4. In this case, the channel 2 is formed on the lower surface of the silicon substrate 1, the reaction catalyst layer 3 is provided in the channel 2, and the thin film heater 7 is provided on the upper surface of the silicon substrate 1.

Next, on the thin film heater 7 on the silicon substrate 1, the anode plate 14 connected to the anode of the DC power source 11 via the switch 13 is placed. In this case, since the thin film heater 7 has conductivity, the same effect as when the anode plate 14 is directly mounted on the silicon substrate 1 can be obtained, and there is no problem. Next, the silicon substrate 1 and the first glass substrate 4
Switch 1 is heated to about 400-600 ° C.
3 is closed and 1k is placed between the DC power source 11 and the bipolar plates 12 and 14.
A DC voltage of about V is applied.

Then, cations, which are impurities in the first glass substrate 4, move in a direction away from the silicon substrate 1,
A layer having a high concentration of oxygen ions appears at the interface of the first glass substrate 4 on the silicon substrate 1 side. Then, the silicon atoms at the interface of the silicon substrate 1 on the side of the first glass substrate 4 and the oxygen ions at the interface of the first glass substrate 4 on the side of the silicon substrate 1 are bonded, and a strong bonding interface is obtained. Thereby, the silicon substrate 1 and the first glass substrate 4 are firmly anodically bonded.

In this case, the silicon substrate 1 and the first glass substrate 4 are heated to about 400 to 600 ° C.
A DC voltage of about 1 kV is applied between 2 and 14 in order to increase the speed at which cations, which are impurities in the first glass substrate 4, move in a direction away from the silicon substrate 1.

Next, as shown in FIG. 12, a second glass substrate 8 having a recess 9 on its upper surface is positioned and placed on the cathode plate 12. Next, the silicon substrate 1 and the first substrate 4 which are anodically bonded to each other are placed on the second glass substrate 8 while being aligned with the silicon substrate 1 as the lower side. next,
The anode plate 14 is placed on the second glass substrate 8. Next, with the silicon substrate 1, the first glass substrate 4 and the second glass substrate 8 being heated to about 400 to 600 ° C., the switch 13 is closed and the DC power source 11 is placed between the bipolar plates 12 and 14 to remove 1
A DC voltage of about kV is applied. Then, as in the case described above, the silicon substrate 1 and the second glass substrate 8 are firmly anodically bonded.

By the way, referring to the silicon substrate 1 and the first glass substrate 4 in FIG. 12, the silicon substrate 1 is connected to the cathode plate 12 through the second glass substrate 8.
Since the first glass substrate 4 is connected to the anode plate 14,
At the time of the second anodic bonding, an electric field in the direction opposite to the direction of the applied electric field at the time of the first anodic bonding is applied between the silicon substrate 1 and the first glass substrate 4. Therefore, reverse migration of ions occurs, the bonding strength between the silicon substrate 1 and the first glass substrate 4 decreases, and there is a risk of peeling.

[0014]

Therefore, in the above-mentioned conventional manufacturing method, although it is effective for anodic bonding between one silicon substrate and one glass substrate, glass is formed on both surfaces of one silicon substrate. When anodizing the substrate,
At the time of the second anodic bonding, the glass substrate anodically bonded the first time may be peeled off from the silicon substrate, so that it was difficult to anodically bond the glass substrates to both surfaces of one silicon substrate. Therefore, an object of the present invention is to provide an anodic bonding structure and an anodic bonding method capable of easily and reliably anodic bonding another substrate to each surface of one substrate.

[0015]

An anodic bonding structure according to a first aspect of the present invention comprises a first substrate, a second substrate anodically bonded to at least a part of one surface of the first substrate, Anodic bonding that enables anodic bonding to at least a part of the other surface of the first substrate with an applied electric field in the same direction as the direction of the applied electric field when anodic bonding the first substrate and the second substrate And a third substrate that is anodically bonded via a layer. The anodic bonding method according to the invention of claim 9 comprises a step of anodic bonding a second substrate to at least a part of one surface of the first substrate, and a step of forming a anodic bond on at least a part of the other surface of the first substrate. 3 anodic bonding of the substrate through an anodic bondable layer capable of anodic bonding with an applied electric field in the same direction as the applied electric field when anodic bonding the first substrate and the second substrate. It is characterized by that. According to the present invention, the anode is applied with an applied electric field in the same direction as the direction of the applied electric field when the third substrate is anodically bonded to at least a part of the other surface of the first substrate. Since the anodic bonding is performed via the anodic bonding layer that enables bonding, the direction of the applied electric field when anodic bonding the first substrate and the second substrate and the first substrate and the third substrate can be anodic bonded. The direction of the applied electric field at the time of anodic bonding through the layers becomes the same, and as a result, for example, after the second substrate is anodically bonded to one surface of the first substrate, the third surface is applied to the other surface of the first substrate. Even if the substrates are anodically bonded, the first strong anodic bonding between the first substrate and the second substrate can be maintained as it is. Therefore, the second substrate can be formed on each side of the first substrate regardless of a special method. And the third substrate can be easily and surely anodically bonded.

[0016]

1 is a transmission plan view of a small chemical reaction device having an anodic bonding structure according to an embodiment of the present invention, and FIG. 2 is a sectional view taken along the line AA. It is a thing. This small chemical reactor comprises a small silicon substrate 21. The dimensions of the silicon substrate 21 are, for example, about 15 to 35 mm in length, about 10 to 25 mm in width, and about 0.4 to 1.0 mm in thickness.

On one surface of the silicon substrate 21, a flow path 22 which is a part of a meandering minute reaction furnace is formed by using the fine processing technology accumulated in the semiconductor manufacturing technology. The dimensions of the flow path 22 are, for example, about 0.2 to 0.8 mm in width and about 0.2 to 0.6 mm in depth, and the total length is 30 to 30 mm.
It is about 1000 mm.

On the inner wall surface of the channel 22, for example, a reaction catalyst layer 23 for carrying out a chemical reaction is provided. The reaction catalyst layer 23 may be provided on the entire inner wall surface of the flow path 22, or may be provided partially. The specific material of the reaction catalyst layer 23 will be described later.

The silicon substrate 21 has a thickness of 0.7 m on one surface.
The first glass substrate 24 of about m is anodically bonded as described later. An inflow port 25 and an outflow port 26 are provided at two predetermined positions corresponding to both ends of the flow path 22 of the first glass substrate 24.

TaSiOx is formed on the other surface of the silicon substrate 21.
A meandering thin film heater 27 made of a resistor thin film such as or TaSiOxN is provided. The membrane heater 27 supplies a predetermined amount of heat energy to the reaction catalyst layer 23 in the flow path 22 during the chemical reaction when the chemical reaction (catalytic reaction) in this small-sized chemical reaction device involves an endothermic reaction under a predetermined thermal condition. belongs to. In this case, the meandering thin film heater 27
Is planarly aligned with the meandering flow path 22, but may not be aligned. Further, the thin film heater 27 may be solid so as to cover the entire surface of the flow path 22.

On the other surface of the silicon substrate 21, the peripheral portion of the second glass substrate 28, in which a recess 29 is formed by counterbore processing in the central portion (area corresponding to the thin film heater 27) of the one surface, of the silicon substrate 21. Anodically bonding is performed as described later through the glass layer 30 provided on the peripheral portion of the other surface and the metal layer 31 provided on the peripheral portion of the second glass substrate 28 facing the silicon substrate 21. The second glass substrate 28 not only protects the thin film heater 27, but also prevents thermal diffusion of the thin film heater 27 and improves thermal efficiency. In addition, the inside of the concave portion 29 may be substantially vacuumed in order to enhance the heat insulating performance.

Next, an example of a method of manufacturing the small-sized chemical reaction device having the above structure will be described. First, as shown in FIG. 3, on the cathode plate 33 connected to the cathode of the DC power source 32,
First glass substrate 2 having inflow port 25 and outflow port 26
4 is positioned and placed. Next, the first glass substrate 24
The silicon substrate 21 is aligned and placed on top. In this case, the channel 22 is formed on the lower surface of the silicon substrate 21, the reaction catalyst layer 23 is provided in the channel 22, the thin film heater 27 is provided on the upper surface of the silicon substrate 21, and the upper surface of the silicon substrate 21 is provided. A glass layer 30 is provided in the peripheral portion.

Here, an example of the method of forming the glass layer 30 will be described. After the thin film heater 27 is formed on the upper surface of the silicon substrate 21 shown in FIG. 3, water glass is applied to the peripheral portion of the upper surface of the silicon substrate 21 by a printing method, a dispenser method, or the like, and dried. A glass layer 30 is formed on.

In this case, the thickness of the glass layer 30 may be equal to or smaller than the thickness of the thin film heater 27, or may be thicker than the thickness of the thin film heater 27. When the thickness of the glass layer 30 is made thicker than the thickness of the thin film heater 27, the peripheral convex portion 36 of the anode plate 35, which will be described later, may have substantially the same size as the region corresponding to the thin film heater 27.

In any case, when the sum of the height of the peripheral convex portion 36 and the thickness of the glass layer 30 is set higher than the thickness of the thin film heater 27, and the anode plate 35 does not contact the thin film heater 27, the anodic bonding is performed. Is desirable from the viewpoint of manufacturing efficiency. Glass layer 3
If 0 is sufficiently thick, it is not necessary to provide the peripheral convex portion 36 on the anode plate 35, but in consideration of the viscosity of water glass, the glass layer 3
When the height of 0 is suppressed and the peripheral convex portion 36 is provided, the manufacturing control is easier. Further, the surface of the glass layer 30 is made flat.

Next, the silicon substrate 21 on the thin film heater 7 side
An anode plate 35, which is connected to the anode of the DC power supply 32 via a switch 34, is placed on the top. Also in this case, since the thin film heater 7 has conductivity, the same effect as when the anode plate 35 is directly placed on the silicon substrate 21 can be obtained, and there is no problem. Next, in a state where the silicon substrate 21 and the first glass substrate 24 are heated to about 400 to 600 ° C.,
The switch 34 is closed and the DC power source 32 is switched to the bipolar plates 33, 3
A DC voltage of about 1 kV is applied between the five.

Then, the cations, which are impurities in the first glass substrate 24, move away from the silicon substrate 21, and a layer having a high concentration of oxygen ions appears at the interface of the first glass substrate 24 on the silicon substrate 21 side. . Then, silicon atoms at the interface of the silicon substrate 21 on the side of the first glass substrate 24 and oxygen ions at the interface of the first glass substrate 24 on the side of the silicon substrate 21 are bonded to each other, and a strong bonding interface is obtained. As a result, the silicon substrate 21 and the first glass substrate 24 are strongly anodically bonded.

Also in this case, the silicon substrate 21 and the first
The glass substrate 24 is heated to about 400 to 600 ° C. and a DC voltage of about 1 kV is applied between the bipolar plates 33 and 35 in the direction in which the cations, which are impurities in the first glass substrate 24, move away from the silicon substrate 21. This is to increase the speed of moving to.

Next, in the state shown in FIG. 3, the anode plate 3
5 is removed, and then, as shown in FIG. 4, a metal layer 31 provided on the peripheral portion of the lower surface of the second glass substrate 28 having a recess 29 in the central portion of the lower surface is provided on the glass layer 30 on the silicon substrate 21. Align and place. At this time, if the second glass substrate 28 is not in contact with the thin film heater 27 due to the concave portion 29, the heat radiation loss of the thin film heater 27 at the time of heating the inside of the flow path 22 as a small chemical reaction device in terms of manufacturing efficiency of anodic bonding. Since it is also excellent in suppressing
The sum of the length of the recessed portion, the thickness of the glass layer 30, and the thickness of the metal layer 31 is preferably longer than the thickness of the thin film heater 27.

Here, an example of a method of forming the metal layer 31 will be described. First, a metal layer containing at least a single metal or an alloy is formed on the entire lower surface of the second glass substrate 28 including the recess 29 by a vapor deposition method or a sputtering method.
When the metal layer formed in the recess 29 is removed by photolithography, the metal layer 31 is formed on the peripheral portion of the lower surface of the second glass substrate 28. As the material of the metal layer 31,
A metal such as Al or Ti that easily forms a metal oxide capable of anodic bonding with the glass layer 30 is preferable. Instead of such a metal layer 31, a silicon layer that can be anodically bonded to the glass layer 30 may be formed.

Next, the anode plate 35 is formed on the second glass substrate 28.
To place. Next, the silicon substrate 21, the first glass substrate 24, the second glass substrate 28, etc. are heated to 400 to 600 ° C.
In a state of being heated to a certain degree, the switch 34 is closed and a DC voltage of about 1 kV is applied between the bipolar plates 33 and 35 from the DC power source 32.

In this case, the direction of the applied electric field during the second anodic bonding shown in FIG. 4 is the same as the direction of the applied electric field during the first anodic bonding shown in FIG. Therefore, the glass layer 3
0 and the metal layer 31 is not present, the silicon substrate 21
Is connected to the cathode plate 33 via the first glass substrate 24,
Since the second glass substrate 28 is connected to the anode plate 35, the silicon substrate 21 and the second glass substrate 28 cannot be anodically bonded.

However, in the case shown in FIG. 4, the glass layer 3 is provided between the silicon substrate 21 and the second glass substrate 28.
0 and the metal layer 31 exist, cations that are impurities in the glass layer 30 move in a direction away from the metal layer 31, and a layer having a high oxygen ion concentration is formed at the interface of the glass layer 30 on the metal layer 31 side. appear. Then, the metal atoms at the interface of the metal layer 31 on the glass layer 30 side and the metal layer 31 of the glass layer 30.
Oxygen ions on the side interface are bonded to form a strong joint interface. Then, the silicon substrate 21 and the second glass substrate 28 are firmly bonded via the glass layer 30 and the metal layer 31 having the strong bonding interface.

Also in this case, the silicon substrate 21, the first glass substrate 24, the second glass substrate 28, etc. are replaced by 400 to 6 pieces.
It is heated to about 00 ° C. and a DC voltage of about 1 kV is applied between the bipolar plates 33 and 35 in order to increase the speed at which cations, which are impurities in the glass layer 30, move in the direction away from the metal layer 31. Is.

Thus, even if the direction of the applied electric field at the time of the second anodic bonding shown in FIG. 4 is the same as the direction of the applied electric field at the time of the first anodic bonding shown in FIG. 2 A glass layer 30 is formed on the peripheral portion of the surface facing the glass substrate 28.
And the metal layer 31 is provided in the peripheral portion of the surface of the second glass substrate 28 facing the silicon substrate 21. Therefore, the silicon substrate 21 and the second glass substrate 28 are substantially anodically bonded via these. can do.

In other words, the glass layer 30 and the metal layer 3
1 shows that even if the direction of the applied electric field at the time of the second anodic bonding shown in FIG. 4 is the same as the direction of the applied electric field at the time of the first anodic bonding shown in FIG. 3, the silicon substrate 21 and the second glass substrate 28
And an anodic bondable layer that enables substantial anodic bonding with.

On the other hand, looking at the silicon substrate 21 and the first glass substrate 24 in FIG.
1 is a glass layer 30, a metal layer 31 and a second glass substrate 2
8 is connected to the anode plate 35 via the first glass substrate 24.
Is connected to the cathode plate 33, and such an electrical connection state is the same as that shown in FIG. Therefore, during the second anodic bonding, the silicon substrate 21 and the first glass substrate 24 are
An electric field in the same direction as the direction of the applied electric field at the time of the first anodic bonding is applied between and.

As a result, the first surface is formed on the lower surface of the silicon substrate 21.
After anodic bonding the glass substrate 24, the silicon substrate 21
Even if the second glass substrate 28 is anodically bonded to the upper surface of the substrate via the glass layer 30 and the metal layer 31, the first strong anodic bonding between the silicon substrate 21 and the first glass substrate 24 can be maintained as it is. Therefore, regardless of a special method, the first and second surfaces of the silicon substrate 21 are respectively
The glass substrates 24 and 28 can be easily and reliably anodically bonded.

In the above embodiment, as shown in FIG. 3, after the first glass substrate 24 is anodically bonded to the lower surface of the silicon substrate 21, as shown in FIG.
The case where the second glass substrate 28 is anodically bonded to the upper surface of the silicon substrate 21 has been described, but conversely, after the second glass substrate 28 is anodically bonded to the upper surface of the silicon substrate 21, the first glass is bonded to the lower surface of the silicon substrate 21. The substrate 24 may be anodically bonded.

Further, for example, in the state shown in FIG.
The first and second glass substrates 24 and 28 may be simultaneously anodically bonded to both surfaces of the silicon substrate 21. That is, the first glass substrate 24 and the silicon substrate 21 are placed in this order on the cathode plate 33, and the silicon substrate 2
The metal layer 31 under the second glass substrate 28 is placed on the glass layer 30 on 1, and the anode plate 35 is placed on the second glass substrate 28. Then, when anodizing treatment is performed in this state, the first glass substrate 24 is anodically bonded to the lower surface of the silicon substrate 21, and at the same time, the glass layer 30 on the silicon substrate 21 and the metal layer 31 below the second glass substrate 28 are bonded. Are anodically bonded.

Next, the case where the small chemical reaction device having the above-mentioned structure is applied to a fuel cell system using a fuel reforming type fuel cell will be described. FIG. 5 is a block diagram of a main part of an example of the fuel cell system 40.
The fuel cell system 40 includes a fuel section 41, a fuel vaporization section 42, a reforming section 43, a carbon monoxide removing section 44, and a power generation section 4.
5, the charging unit 46 and the like.

The fuel section 41 is composed of a fuel pack or the like in which a fuel for power generation (for example, an aqueous methanol solution) is enclosed, and supplies the fuel for power generation to the fuel vaporization section 42.

The fuel vaporizing section 42 has a structure as shown in FIGS. 1 and 2, for example. However, in this case,
The reaction catalyst layer 23 is not provided in the flow path 22. Then, when the power generation fuel from the fuel unit 41 is supplied into the flow path 22 through the inflow port 25, the fuel vaporization section 42 heats the thin film heater 27 (about 120 ° C.) in the flow path 22. The power generation fuel is vaporized, and the vaporized power generation fuel gas (for example, CH ₃ OH + H ₂ O when the power generation fuel is an aqueous methanol solution) is caused to flow out from the outlet 26.

The power generation fuel gas (CH ₃ OH + H ₂ O) vaporized in the fuel vaporization section 42 is supplied to the reforming section 43. In this case, the reforming section 43 also has a structure as shown in FIGS. However, in this case, the silicon substrate 21
A reaction catalyst layer 23 is provided in the flow path 22 of 1. The reaction catalyst layer 23 is made of a reforming catalyst such as Cu, ZnO, or Al ₂ O ₃ . When the power generation fuel gas (CH ₃ OH + H ₂ O) from the fuel vaporization section 42 is supplied into the flow path 22 through the inflow port 25, the reforming section 43 receives the flow path 22.
Inside, the thin film heater 27 is heated (about 280 ° C.) to cause an endothermic reaction as shown in the following formula (1) to generate hydrogen and by-product carbon dioxide. CH ₃ OH + H ₂ O → 3H ₂ + CO ₂ (1)

Water (H ₂ O) on the left side of the above formula (1)
May be contained in the fuel of the fuel unit 41 at the initial stage of the reaction, but water generated by power generation of the power generation unit 45 described later may be recovered and supplied to the reforming unit 43. Good. The water (H ₂ O) supply source on the left side of the above equation (1) during power generation by the power generation unit 45 may be only the power generation unit 45, the power generation unit 45 and the fuel unit 41, or the fuel unit 41.
It may be alone. At this time, carbon monoxide may be generated in the reforming section 43, although the amount is small.

The products (hydrogen, carbon dioxide) on the right side of the above formula (1) and a trace amount of carbon monoxide are added to the reforming section 43.
Is discharged from the outlet 26 of the. Outlet 26 of reforming section 43
Hydrogen and carbon monoxide in a vaporized state among the products flown out of are supplied to the carbon monoxide removing unit 44, and carbon dioxide is separated and released into the atmosphere.

Next, the carbon monoxide removing portion 44 also has a structure as shown in FIGS. However, in this case, the reaction catalyst layer 23 is made of, for example, a selective oxidation catalyst such as Pt or Al ₂ O ₃ . Then, the carbon monoxide removing unit 44 heats the thin film heater 27 (about 180 ° C.) when vaporized hydrogen and carbon monoxide from the reforming unit 43 are supplied into the flow path 22 through the inflow port 25. ), Among the hydrogen, carbon monoxide, and water supplied into the flow path 22, carbon monoxide and water react, and as shown in the following formula (2),
Hydrogen and the by-product carbon dioxide are produced. CO + H ₂ O → H ₂ + CO ₂ (2)

Water (H ₂ O) on the left side of the above formula (2)
May be contained in the fuel of the fuel unit 41 at the initial stage of the reaction, but it is possible to collect the water generated by the power generation of the power generation unit 45 and supply it to the carbon monoxide removal unit 44. . Further, the reaction formula (2) in the carbon monoxide removing unit 44
The water supply source on the left side of the power source may be only the power generation unit 45, the power generation unit 45 and the fuel unit 41, or the fuel unit 41.
It may be alone.

Most of the fluid finally reaching the outflow port 26 of the carbon monoxide removing section 44 is hydrogen and carbon dioxide. The outlet 2 of the carbon monoxide removing unit 44
When the fluid reaching 6 contains a very small amount of carbon monoxide, the remaining carbon monoxide is brought into contact with oxygen taken in from the atmosphere through the check valve to obtain the following formula (3). As shown in, carbon dioxide is produced, which ensures removal of carbon monoxide. CO + (1/2) O ₂ → CO ₂ …… (3)

The product after the above series of reactions is composed of hydrogen and carbon dioxide (including a trace amount of water in some cases). Of these products, carbon dioxide is separated from hydrogen and released into the atmosphere. To be done. Therefore, only hydrogen is supplied from the carbon monoxide removing unit 44 to the power generation unit 45. The carbon monoxide removing unit 44 may be provided between the fuel vaporizing unit 42 and the reforming unit 43.

Next, the power generation section 45, as shown in FIG.
It is a well-known polymer electrolyte fuel cell. That is, the power generation unit 45 includes a cathode 51 including a carbon electrode to which a catalyst such as Pt and C is attached, an anode 52 including a carbon electrode to which a catalyst such as Pt, Ru and C is attached, a cathode 51 and an anode 52. And a film-like ionic conductive film 53 interposed between the charging unit 46 and the charging unit 46 including a secondary battery and a capacitor provided between the cathode 51 and the anode 52. To do.

In this case, a space 54 is provided outside the cathode 51. Hydrogen is supplied from the carbon monoxide removing unit 44 into the space 54, and hydrogen is supplied to the cathode 51. A space 55 is provided outside the anode 52. Oxygen taken from the atmosphere through the check valve is supplied into the space 55, and oxygen in the anode 52 is supplied.

Then, on the cathode 51 side,
As shown in (4), from hydrogen to electrons (e ^-) Separated
Hydrogen ion (proton; H⁺) Occurs, and the ionic conductive film
It passes through 53 to the anode 52 side and
The electronic signal (e^-) Is taken out and the charging unit 46
Is supplied to. 3H₂→ 6H⁺+ 6e^-…… (4)

On the other hand, on the anode 52 side, the following equation (5)
As shown in, the electron (e ⁻ ) supplied through the charging unit 46 reacts with the hydrogen ion (H ⁺ ) passing through the ion conductive film 63 and oxygen to generate water as a by-product. . 6H ⁺ + (3/2) O ₂ + 6e ⁻ → 3H ₂ O (5)

The above series of electrochemical reactions (formula (4) and formula (5)) proceed in a relatively low temperature environment of about room temperature to 80 ° C., and byproducts other than electric power are basically It is only water. The electric power generated by the power generation unit 45 is supplied to the charging unit 46, which charges the charging unit 46.

Water as a by-product produced in the power generation section 45 is recovered. In this case, as described above, if at least a part of the water generated in the power generation unit 45 is supplied to the reforming unit 43 and the carbon monoxide removing unit 44, the amount of water initially enclosed in the fuel unit 41 will be increased. Can be reduced, and the amount of water recovered can be reduced.

By the way, the fuel applied to the fuel cell of the fuel reforming system currently being researched and developed is at least a liquid fuel containing hydrogen element, a liquefied fuel or a gas fuel, and With 45, any fuel can be used as long as it can generate electric energy with relatively high energy conversion efficiency.
For example, alcohol-based liquid fuels such as ethanol and butanol, liquid fuels composed of hydrocarbons that are vaporized at room temperature and normal pressure such as liquefied gases such as dimethyl ether, isobutane, and natural gas (CNG), or gases such as hydrogen gas. Fluid materials such as fuel can be applied well.

In the above embodiment, as shown in FIG. 2, the metal layer 31 is formed only on the peripheral portion of the lower surface of the second glass substrate 28.
Although the case where the above is provided has been described, the present invention is not limited to this. For example, like the other embodiment of the present invention shown in FIG. 7, the metal layer 31a may be provided also in the recess 29 of the second glass substrate 28. This metal layer 31a
Is for functioning as a heat ray reflective layer, suppressing heat conduction to the second glass substrate 28, and suppressing heat radiation from the outer surface of the second glass substrate 28. Accordingly, it is possible to suppress the thermal energy loss when the inside of the flow path 22 is heated by the heat generation of the thin film heater 27, and it is possible to improve the energy utilization efficiency.

In this case, the metal layer 31a may be formed of the same metal as the metal layer 31, for example, a metal such as Al having a high heat ray reflectance. In this case, it is only necessary to form a metal layer of Al or the like on the entire lower surface of the second glass substrate 28 including the recess 29 by a vapor deposition method, a sputtering method or the like, and the photolithography can be omitted. it can. Further, the metal layer 31a may be formed of a metal different from the metal layer 31, for example, a metal such as Ag having a high heat ray reflectance.

In the above embodiment, the glass layer 30 is formed by applying water glass by a printing method or a dispenser method. However, the present invention is not limited to this, and the silicon oxide is formed by oxidizing the peripheral portion of the upper surface of the silicon substrate 21. The glass layer can be formed by forming the film. As a method for manufacturing a silicon oxide film, first, the surface of the silicon substrate 21 is dipped in a mixed solution of an aqueous ammonia solution and an aqueous hydrogen peroxide solution, further surface-treated with an aqueous solution of hydrochloric acid and an aqueous solution of hydrogen peroxide, and then dried, and then the silicon substrate 21. An oxidizer is provided in the peripheral portion of the upper surface of the silicon substrate 21, and then the silicon substrate 21 is placed in a thermal oxidation furnace for thermal oxidation, whereby a silicon oxide film is selectively formed in the peripheral portion of the upper surface of the silicon substrate 21. The silicon oxide film can be easily aligned with the metal layer 31 because the single crystal silicon is oxidized and expanded. If the substrates 21, 24, 28 can be anodically bonded,
It need not be silicon or glass.

Further, in the above embodiment, as shown in FIG. 2, the case where the glass layer 30 is provided in the peripheral portion of the upper surface of the silicon substrate 21 and the metal layer 31 is provided in the peripheral portion of the lower surface of the second glass substrate 28 will be described. However, the present invention is not limited to this. For example, as in another embodiment of the present invention shown in FIG. 8, a glass layer 30 is provided in a region other than the flow path 22 on the lower surface of the silicon substrate 21, and the inlet 25 and the flow port on the upper surface of the first glass substrate 24 are provided. The metal layer 3 is formed in the area other than the outlet 26.
1 may be provided. At this time as well, the anodic bonding order between the silicon substrate 21, the first glass substrate 24 and the second glass substrate 28 may be either, or they may be collectively anodic bonded.

Further, in the above embodiment, the case where the present invention is applied to the small chemical reaction device has been described, but the present invention is not limited to this and may be applied as long as a glass substrate is anodically bonded to both surfaces of the silicon substrate. You can Further, it can be applied to those in which a silicon substrate is anodically bonded to both surfaces of a glass substrate.

[0063]

As described above, according to the present invention, the applied electric field when the third substrate is anodically bonded to at least a part of the other surface of the first substrate is the third substrate. Since the anodic bonding is performed via the anodic bonding layer capable of anodic bonding with the applied electric field in the same direction as the direction, the direction of the applied electric field and the first substrate when the anodic bonding is performed between the first substrate and the second substrate. And the direction of the applied electric field when anodic-bonding the third substrate via the anodic-bondable layer are the same. As a result, for example,
Even if the third substrate is anodically bonded to the other surface of the first substrate after the second substrate is anodically bonded to one surface of the first substrate, the first strong anode of the first substrate and the second substrate is obtained. The bonding can be maintained as it is, and therefore, the second substrate and the third substrate can be easily and surely anodically bonded to both surfaces of the first substrate without depending on a special method.

[Brief description of drawings]

FIG. 1 is a transparent plan view of a small chemical reaction device as an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a sectional view of an initial step in manufacturing the small chemical reaction device shown in FIGS. 1 and 2.

FIG. 4 is a sectional view of a step following FIG. 3;

FIG. 5 is a block diagram of a main part of an example of a fuel cell system including a small chemical reaction device.

6 is a schematic configuration diagram of a power generation unit and a charging unit of the fuel cell system shown in FIG.

FIG. 7 is a sectional view of a small-sized chemical reaction device as another embodiment of the present invention, similar to FIG.

FIG. 8 is a sectional view similar to FIG. 2 of a small-sized chemical reaction device as still another embodiment of the present invention.

FIG. 9 is a transparent plan view of an example of a conventional small chemical reaction apparatus.

10 is a cross-sectional view taken along the line BB of FIG.

FIG. 11 is a sectional view of an initial step in manufacturing the small chemical reaction device shown in FIGS. 9 and 10.

12 is a sectional view of a step following FIG. 11. FIG.

[Explanation of symbols]

21 Silicon substrate 22 flow path 23 Reaction catalyst layer 24 First glass substrate 25 Inlet 26 Outlet 27 Thin film heater 28 Second glass substrate 29 recess 30 glass layers 31 metal layer 32 DC power supply 33 cathode plate 34 switch 35 Anode plate

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 3K092 PP09 QA05 QB03 QB45 RF03                       RF08 RF17 RF22                 4G061 AA02 BA00 CA01 CD02 DA21                 4G075 AA01 AA39 BA10 CA02 CA54                       DA02 EA05 EB01 EC21 EE22                       EE23 FA01 FA12 FB02 FB06                       FB20

Claims (14)

[Claims] 1. A first substrate, a second substrate anodically bonded to at least a part of one surface of the first substrate, and a first substrate on at least a part of the other surface of the first substrate. And a third substrate anodic-bonded via an anodic-bondable layer that enables anodic bonding with an applied electric field in the same direction as the direction of the applied electric field when anodic-bonding the second substrate. Characteristic anodic bonding structure. 2. The invention according to claim 1, wherein the first substrate is a silicon substrate, and the second substrate and the third substrate are a first glass substrate and a second glass substrate. Anodic bonding structure. 3. The invention according to claim 2, wherein the anodic bondable layer is a glass layer provided on at least a part of the other surface of the silicon substrate, and the silicon substrate of the second glass substrate. An anodic bonding structure comprising a metal layer or a silicon layer provided on the opposite surface of the metal layer corresponding to the glass layer. 4. The anodic bonding structure according to claim 3, wherein a minute reaction furnace is formed on one surface of the silicon substrate. 5. The anodic bonding structure according to claim 1, wherein a thin film heater is provided on the other surface of the first substrate. 6. The invention according to claim 5, wherein a concave portion is provided in a region corresponding to the thin film heater on a surface facing the thin film heater on one of the first substrate and the second substrate. An anodic bonding structure characterized by being provided. 7. The invention according to claim 1, wherein the first substrate is a glass substrate, and the second substrate and the third substrate are a first silicon substrate and a second silicon substrate. Anodic bonding structure. 8. The invention according to claim 7, wherein the anodic bondable layer is a metal layer or a silicon layer provided on at least a part of the other surface of the glass substrate, and the second silicon substrate is provided with the metal layer or the silicon layer. An anodic bonding structure comprising a glass layer provided on a surface facing a glass substrate so as to correspond to the metal layer or the silicon layer. 9. A step of anodic bonding a second substrate to at least a part of one surface of a first substrate, and a third substrate and the first substrate to at least a part of the other surface of the first substrate. And a step of anodic bonding through an anodic bondable layer capable of anodic bonding with an applied electric field in the same direction as the direction of the applied electric field when the anodic bonding is performed with the second substrate. 10. The invention according to claim 9, wherein the second substrate is provided on one surface and the other surface of the first substrate, respectively.
An anodic bonding method comprising simultaneously anodic bonding a substrate and the third substrate. 11. The invention according to claim 9 or 10, wherein the first substrate is a silicon substrate, and the second substrate
The anodic bonding method, wherein the substrate and the third substrate are composed of a first glass substrate and a second glass substrate. 12. The invention according to claim 11, wherein the anodic bondable layer is a glass layer provided on at least a part of the other surface of the silicon substrate, and the silicon substrate of the second glass substrate. And a metal layer or a silicon layer provided corresponding to the glass layer on the opposing surface of the anodic bonding method. 13. The invention according to claim 9 or 10, wherein the first substrate is a glass substrate, and the second substrate and the third substrate are a first silicon substrate and a second silicon substrate. And anodic bonding method. 14. The invention according to claim 13, wherein the anodic bondable layer includes a metal layer or a silicon layer provided on at least a part of the other surface of the glass substrate, and the second silicon substrate. An anodic bonding method comprising: a glass layer provided on a surface facing a glass substrate so as to correspond to the metal layer or the silicon layer.