JP2000220766A - Semiconductor microvalve and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor microvalve and manufacture thereof capable of a broad range of flow control and wherein a small and normally open type valve is easily formed. SOLUTION: A semiconductor substrate 1 having a through hole 1a and a projection part 1c being a valve seat provided near an opening of the through hole 1a, and a flat form flexible part 2 oppositely placed with a predetermined gap width in between a surface having the projection 1c of the semiconductor substrate 1 formed are included, and a flow control of fluid is performed by displacing the flexible part 2 for adjusting the gap width.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a semiconductor microvalve used for controlling a flow rate of a gas or the like, and a method for manufacturing the same.

[0002]

2. Description of the Related Art In an electronic sphygmomanometer, two types of valves called a constant speed exhaust valve and a high speed exhaust valve are used for controlling the pressure of air. The former is to send pressurized air to the cuff band wound around the arm or wrist, and to lower the air pressure in the cuff band after stopping blood flow at a predetermined speed (2.5 mmHg / sec.). The latter is for returning the air pressure in the cuff band to the atmospheric pressure in a short time of about 1 second after the blood pressure measurement is completed or in an emergency.

Generally, a constant-speed exhaust valve is disclosed in Japanese Patent Application Laid-Open No.
The one using a rubber tube as disclosed in Japanese Patent Publication No. 74, and the solenoid valve using a solenoid are often used as high-speed exhaust valves.

In order to reduce the size of the sphygmomanometer, these two
It is necessary to replace each type of valve with a small actuator capable of controlling the flow rate of air. One of them is a semiconductor microvalve using silicon.

[0005] Conventionally, as this kind of semiconductor microvalve, as shown in USP5069419 and USP5058856, FIG.
The structure shown in FIG. As shown in FIG. 11, the semiconductor microvalve is configured by using two silicon substrates 1 and 12, which are semiconductor substrates. A through hole 1a penetrating from the two main surface sides to the one main surface side is formed at substantially the center of the silicon substrate 1, and a groove 1b is formed in one main surface of the silicon substrate 1 around the opening on one main surface side of the through hole 1a. Is formed to form the projection 1c. Here, the surface of the protruding portion 1c forms the same plane as one main surface side of the supporting portion 1d which forms the peripheral portion of the silicon substrate 1.

Further, the two main surfaces of the silicon substrate 12 are machined to form a valve body 12a opposed to the through hole 1a, and a support portion 12c for supporting the valve body 12a via a thin flexible portion 12b. Are formed. Here, the two main surface sides of the support portion 12c and the two main surface sides of the valve element 12a form the same plane.

Further, one main surface side of the support portion 1d and the support portion 1d
The two main surfaces 2c are connected to each other, whereby a gap 13 defined by the silicon substrates 1 and 12 is formed.
The fluid outlet 4 penetrating from the two main surfaces of the silicon substrate 1 to the one main surface is formed so as to communicate with the gap 13.

This semiconductor microvalve has a valve body 12a.
A flow path is formed between the two main surface sides and the surface of the projection 1c to control the flow rate of the fluid. The fluid is introduced into the valve through the through-hole 1a and flows out of the outlet 4 through the gap 13.
It is discharged out of the valve.

Here, in order to control the flow rate of the fluid, some valve drive unit for displacing the flexible portion 12b is required. Various methods are used for the valve drive unit in addition to those using electrostatic force or electromagnetic force.
9419 and USP5058856 are made of aluminum (Al) or nickel (Ni) and silicon (Si) bimetal,
The bimetal is bent by thermal expansion to form a flexible portion 12b.
Are disclosed.

When a semiconductor microvalve is applied to pressure control of an electronic sphygmomanometer, (1) a constant speed exhaust valve (10 to 100 S
CCM) and high-speed exhaust valve (approx. 1000SCCM) can cover a wide range of flow rates. (2) Low power consumption. (3) Normally open type. (4) Withstand pressure about 1.5 atm (760mmHg)
+ 350mmHg = 1110mmHg).

FIG. 12 is a characteristic diagram showing the relationship between the pressure and the flow rate of the conventional semiconductor microvalve at the time of constant-speed exhaust, and FIG. 13 is the input pressure and gap width of the conventional semiconductor microvalve. FIG. 3 is a characteristic diagram showing a relationship between the flow rate and the flow rate. 12 and 13, the flow characteristics of the semiconductor microvalve greatly depend on the gap width, and when considering the use of an electronic sphygmomanometer, it is indispensable to realize a valve capable of greatly changing the gap width (for example, 0 to 0). 40 μm).

[0012]

However, in the semiconductor microvalve having the above structure, for example, "Electrica"
lly-Activated Micromachined Diaphragm Valves, Hal J
erman, IC Sensors, Technical Digest IEEE Solid-State
Sensor and Actuator Workshop, p.65-69, Jun. 1990 "
As described in the above, there was a problem that the maximum gap width was only about 25 μm, and the flow rate could only be controlled up to 100 SCCM.

Conventionally, the valve body 12a has a so-called boss structure. This structure is a valve element 1
The weight of the valve element 2a is effective for completely closing the valve when the input pressure of the fluid is high. However, it is difficult to reduce the size of the valve element, particularly in the thickness direction. Relatively high precision is required for the alignment with the silicon substrate 1 and 12 and it is necessary to bond the silicon substrates 1 and 12 with high precision.
However, there is a problem that the size becomes larger in the lateral direction.

[0014] Further, a semiconductor microvalve using a bimetal has a problem that it normally has to be a normally closed type.

The present invention has been made in view of the above points, and it is an object of the present invention that a small-sized normally open valve can be easily formed and a wide range of flow control can be performed. An object of the present invention is to provide a semiconductor microvalve and a method for manufacturing the same.

[0016]

According to the first aspect of the present invention,
A semiconductor substrate having a through hole and a projection serving as a valve seat provided in the vicinity of the opening of the through hole; and a semiconductor substrate facing the surface of the semiconductor substrate where the projection is formed, with a predetermined gap width therebetween. A flexible portion having a flat plate shape, and controlling the flow rate of the fluid by adjusting the gap width by displacing the flexible portion.

According to a second aspect of the present invention, in the semiconductor microvalve according to the first aspect, the gap width is formed by forming the flexible portion on the semiconductor substrate via a gap forming layer. It is a feature.

According to a third aspect of the present invention, in the semiconductor microvalve according to the first or second aspect, the flexible portion has a diaphragm shape.

According to a fourth aspect of the present invention, in the semiconductor microvalve according to the first or second aspect, the flexible portion is disposed at a position corresponding to an opening of the through hole; And a plurality of beams extending from the outer periphery of the body.

According to a fifth aspect of the present invention, there is provided the semiconductor microvalve according to any one of the first to fourth aspects, wherein a metal layer is formed at a predetermined portion of the flexible portion, and a material for forming the metal layer is provided. And a material forming the flexible portion, and a bimetal is formed, and the flexible portion is displaced by a difference in thermal expansion coefficient between the metal layer and the material forming the flexible portion. Things.

According to a sixth aspect of the present invention, in the semiconductor microvalve according to the fifth aspect, the metal layer is formed using aluminum or nickel, and the flexible portion is formed using silicon. Is what you do.

According to a seventh aspect of the present invention, in the semiconductor microvalve according to any one of the first to fourth aspects, a shape memory alloy wire is arranged at a predetermined position on the flexible portion, and By interposing a stopper facing the flexible portion through a spacer having the same thickness as the shape memory alloy wire above, by generating a force generated by deformation of the shape memory alloy wire in a predetermined direction by the stopper,
The flexible part is displaced.

According to an eighth aspect of the present invention, in the semiconductor microvalve according to any one of the first to fourth aspects, a shape memory alloy foil is disposed on the flexible portion, and the shape memory alloy foil is deformed. Wherein the flexible portion is displaced by utilizing the force generated by the elastic member.

According to a ninth aspect of the present invention, in the semiconductor microvalve according to any one of the first to fourth aspects, a shape memory alloy foil is used as a material of the flexible portion. The flexible portion is displaced by utilizing the deformation / restoration of (1).

According to a tenth aspect of the present invention, there is provided the method of manufacturing a semiconductor microvalve according to any one of the second to ninth aspects, wherein a predetermined portion is etched using Si-BO glass as the gap forming layer. In this case, the gap width is formed.

[0026]

Embodiments of the present invention will be described below with reference to the drawings.

Embodiment 1 FIG. 1 is a schematic sectional view showing a semiconductor microvalve according to an embodiment of the present invention. The semiconductor microvalve according to the present embodiment has a silicon substrate 1 as a semiconductor substrate.
Has a through hole 1a that penetrates from the two main surface sides substantially at the center to the one main surface side. On the periphery of the opening of the through hole 1a on the one main surface side of the silicon substrate 1, a projection 1c is formed by forming a groove 1b on one main surface of the silicon substrate 1. Therefore, the surface of the projection 1c and the silicon substrate 1
And one main surface of the support portion 1d which forms the peripheral portion of.

Further, a thin flexible portion 2 made of a semiconductor substrate such as a silicon substrate is opposed to one main surface side of the silicon substrate 1 with a predetermined gap therebetween. Here, the peripheral portion of the flexible portion 2 is joined to the silicon substrate 1 via the gap forming layer 3 formed on the support portion 1d.

The thickness of the gap forming layer 3 is determined by a maximum displacement (gap width) designed based on a desired flow rate range to be controlled, and the thickness of the flexible portion 2 is determined by the maximum displacement and the maximum displacement. Based on the working pressure range, it is determined from a material dynamic calculation.

As an example of the above calculation, when used as an exhaust valve of an electronic sphygmomanometer, the maximum displacement is 40 μm.
The thickness of the gap forming layer 3 is determined to be 40 μm. Also,
At an input pressure of up to 152 kPa, the distortion caused by the pressure of the flexible portion 2 when the valve is closed changes depending on the thickness of the flexible portion 2 as shown in FIG. To suppress, the thickness of the flexible part 2 is 15μ
m is required.

In the present embodiment, the flexible portion 2 is used as a valve body as it is, and the gap between the flexible portion 2 and the projection 1c is used as a flow path, and the flow rate of the fluid is controlled by the gap width. Since there is no large boss structure as in the conventional example, downsizing of the element (especially in the thickness direction) can be realized, alignment between the protrusion 1c and the flexible portion 2 serving as a valve body is facilitated, and alignment margin is provided. Does not need to be large.

Further, for the same generated force, a larger displacement can be obtained as compared with the boss structure, and furthermore, by providing the gap forming layer 3, a normally open type which has been difficult to realize conventionally. Valve can be obtained.

Embodiment 2 = FIGS. 3A and 3B are schematic structural views showing a semiconductor microvalve according to another embodiment of the present invention, wherein FIG. 3A is a schematic sectional view, and FIG. FIG. 4 is a schematic plan view showing a state in which it is seen. The semiconductor microvalve according to the present embodiment is the same as the semiconductor microvalve shown in FIG. 1 described as the first embodiment, except that the flexible portion 2 has a diaphragm shape and is formed by a gap between the silicon substrate 1 and the flexible portion 2. A fluid outlet 4 is provided in the gap forming layer 3 so as to communicate with a flow path.

In this embodiment, the outlet 4
Is provided in the gap forming layer 3, but is not limited thereto, and may be provided in the silicon substrate 1.

Therefore, in the present embodiment, in addition to the effects of the first embodiment, the flow rate of the fluid can be controlled even when the flexible portion 2 has a diaphragm shape.

Embodiment 3 = FIGS. 4A and 4B are schematic structural views showing a semiconductor microvalve according to another embodiment of the present invention, wherein FIG. 4A is a schematic sectional view, and FIG. FIG. 4 is a schematic plan view showing a state in which it is seen. In the semiconductor microvalve according to the present embodiment, in the semiconductor microvalve shown in FIG. 1 as the first embodiment, the flexible portion 2 extends in four directions from a central portion 2a serving as a valve body and an outer peripheral edge of the central portion 2a. And a frame 2c for supporting the beam 2b.

Therefore, in the present embodiment, the region removed to form the beam 2b can be used as the fluid outlet 4 as it is.
Thus, the same effect as in the second embodiment can be obtained without separately forming the outflow port 4.

Further, since the flexible portion 2 has the structure having the beam 2b, a larger displacement can be obtained as compared with the second embodiment.

In the present embodiment, the case where four beams 2b are formed has been described. However, the present invention is not limited to this, and the number of beams 2b such as two, eight, and sixteen is formed. May be formed.

Here, an example of a manufacturing process of the semiconductor microvalve according to the present embodiment will be described with reference to the drawings. FIG. 5 is a schematic sectional view showing a manufacturing process of the semiconductor microvalve according to the present embodiment. First, a protective film (not shown) such as a silicon nitride film is formed on both surfaces of the silicon substrate 1.
Is formed, and the protective film on one main surface of the silicon substrate 1 is removed by etching to form an opening.

Subsequently, anisotropic etching is performed on one main surface of the silicon substrate 1 using an alkaline etchant such as a potassium hydroxide (KOH) solution, using the protective film in which the opening is formed as a mask. A groove 1b and a protrusion 1c are formed by etching, and the protective film is removed by etching (FIG. 5).
(A)).

Next, the Si—B—O as the gap forming layer 3 is formed.
A glass 3a is deposited on one main surface of the silicon substrate 1, and the surface is flattened by heat treatment (FIG. 5B). At this time, the thickness of the Si-B-O glass 3a is determined by the maximum gap width designed based on a desired flow rate range to be controlled.

Next, a semiconductor substrate such as a silicon substrate prepared separately is bonded onto the Si--B--O glass 3a and polished to form the flexible portion 2 (FIG. 5C). At this time, the thickness of the flexible portion 2 is determined from material dynamic calculation based on the displacement required for the flow rate control.

Next, a protective film 5 such as a silicon nitride film is formed on the flexible portion 2 and the two main surfaces of the silicon substrate 1, and a desired portion (a portion where the through hole 1a is formed) is removed by etching. Is formed and anisotropic etching is performed using an alkaline etchant with the protective film 5 in which the opening is formed as a mask, so that a through hole penetrating from the two main surface sides of the silicon substrate 1 to one main surface side is formed. 1a (FIG. 5)
(D)).

Next, an acidic etchant such as an HF solution is introduced from the through-hole 1a, and a desired portion of the Si-B-O glass 3a is etched by a sacrifice layer (FIG. 5E). The Si-B-O glass 3a remaining by this sacrificial layer etching becomes the gap forming layer 3, and the region where the sacrificial layer is etched becomes a fluid flow path.

Finally, a valve driving unit (such as a metal layer 6 in FIG.
(FIG. 5 (f)), and the flexible portion 2 is patterned into a predetermined shape by reactive ion etching (RIE) or the like (FIG. 5F). 5 (g)).

If it is necessary to form the outlet 4 separately, after forming the Si--B--O glass 3a, the necessary region is patterned before the sacrificial layer is etched.
The outlet 4 is formed by performing etching.

Therefore, according to the present manufacturing process, the gap forming layer 3 and the flow path are formed by the sacrifice layer etching using the Si—B—O glass 3a as the material of the gap forming layer 3, so that the processing is performed. It can be performed easily and accurately.

Embodiment 4 = FIGS. 6A and 6B are schematic structural views showing a semiconductor microvalve according to another embodiment of the present invention, wherein FIG. 6A is a schematic sectional view, and FIG. FIG. Here, a configuration of a bimetal structure as a valve driving unit of the microvalve will be described. Here, as a schematic configuration of the semiconductor microvalve, a configuration similar to that of the semiconductor microvalve shown in FIG. 4 will be described as a third embodiment, but the present invention is also applied to a configuration of a semiconductor microvalve of another embodiment. it can.

The semiconductor microvalve according to the present embodiment is the same as the semiconductor microvalve shown in FIG. 4, except that a metal layer 6 is formed on the beam 2b, and a bimetal is formed by the metal layer 6 and silicon constituting the beam 2b. ing. The beam 2b below the metal layer 6 includes an impurity diffusion layer 7
Are formed.

Here, the material and thickness of the metal layer 6 are determined mechanically based on the maximum displacement and the working pressure range in consideration of the coefficient of linear expansion, the Young's modulus, and the like. As a material of the metal layer 6, aluminum (Al) or nickel (Ni) is often used.

When the impurity diffusion layer 7 is energized, the temperatures of the beam 2b and the metal layer 6 increase due to heat generation, and the respective volumes expand. Therefore, the beams 2b have different lengths, and accordingly, the beam 2b is bent downward.
Therefore, by adjusting the amount of heat generated in the impurity diffusion layer 7 and the magnitude of the current, the amount of deflection of the beam 2b can be controlled, and the flow rate of the fluid can be controlled.

As an example of the above calculation, when used as an exhaust valve of an electronic sphygmomanometer, the thickness of the gap forming layer 3 is 40 μm.
When the thickness of the flexible portion 2 is 15 μm, the thickness of the metal layer 6 is T
From the displacement calculation formula of bimetal derived by imoschenko, the material of the metal layer 6 is about 10 μm for Al and about 7 μm for Ni.
m.

A different valve driving section will be described with reference to FIG. FIG. 7 is a schematic cross-sectional view of a semiconductor microvalve according to another embodiment of the present invention, in which (a) is a schematic cross-sectional view showing a state where the microvalve is opened;
(B) is a schematic sectional view showing a state in which the microvalve is closed. Also in this embodiment, the schematic configuration of the semiconductor microvalve will be described as a third embodiment using the same configuration as that of the semiconductor microvalve shown in FIG. 4, but the configuration of the semiconductor microvalve of other embodiments is also described. Applicable.

The semiconductor microvalve according to the present embodiment is different from the semiconductor microvalve shown in FIG. 4 in that a flat plate-like stopper 9 is
Are arranged opposite to each other. Then, the stopper 9 and the flexible portion 2
Is formed with a shape memory alloy wire 10 having the same thickness as the spacer 8. Here, it is necessary to consider the material and thickness of the stopper 9 so that the stopper 9 is not easily deformed by application of a force.

As shown in FIG. 8, a shape elongated in the thickness direction is stored in the shape memory alloy wire 10 in advance, and the shape memory alloy wire 10 is energized to increase the temperature. The shape memory alloy wire 10 extends in the thickness direction, and pushes down the flexible portion 2 as shown in FIG. 7B. Therefore, by adjusting the temperature of the shape memory alloy wire 10, the elongation in the thickness direction of the shape memory alloy wire 10 can be controlled to control the flow rate of the fluid. Here, the shape memory alloy is one of the effective means for driving the microvalve because a large generating force is obtained in proportion to the size (volume) thereof.

It should be noted that the amount of elongation to be stored in the shape memory alloy wire 10 is desirably within about 5% of the initial thickness of the shape memory alloy wire 10 due to the problem of life in repeated use. For example, if a displacement of 40 μm is required, the initial thickness of the shape memory alloy wire 10 is 800
It is sufficient if it is at least μm.

Further, different valve driving units will be described with reference to FIG. FIG. 9 is a schematic cross-sectional view of a semiconductor microvalve according to another embodiment of the present invention, in which (a) is a schematic cross-sectional view showing a state in which the microvalve is opened;
(B) is a schematic sectional view showing a state in which the microvalve is closed. Also in this embodiment, the schematic configuration of the semiconductor microvalve will be described as a third embodiment using the same configuration as that of the semiconductor microvalve shown in FIG. 4, but the configuration of the semiconductor microvalve of other embodiments is also described. Applicable.

The semiconductor microvalve according to the present embodiment has a configuration in which the shape memory alloy foil 11 is provided on the flexible portion 2 in the semiconductor microvalve shown in FIG.

In the present embodiment, the shape memory alloy foil 11 is previously stored with the shape deformed downward, and the shape memory alloy foil 11 is energized to increase the temperature, thereby increasing the shape memory alloy foil 11. The alloy foil 11 is deformed into the memorized shape, and the flexible portion 2 is pushed down. Therefore, by adjusting the temperature of the shape memory alloy foil 11, the deformation of the shape memory alloy foil 11 can be controlled to control the flow rate of the fluid.

Another different valve driving section will be described with reference to FIG. FIG. 10 is a schematic sectional view of a semiconductor microvalve according to another embodiment of the present invention,
(A) is a schematic sectional view showing a state where the microvalve is opened, and (b) is a schematic sectional view showing a state where the microvalve is closed. Also in this embodiment, the schematic configuration of the semiconductor microvalve will be described as a third embodiment using the same configuration as that of the semiconductor microvalve shown in FIG. 4, but the configuration of the semiconductor microvalve of other embodiments is also described. Applicable.

The semiconductor microvalve according to the present embodiment has a configuration in which a shape memory alloy foil is used as the material of the flexible portion 2 in the semiconductor microvalve shown in FIG.

In the present embodiment, the shape deformed downward is stored in advance in the flexible portion 2 made of a shape memory alloy foil, and the temperature is increased by supplying electricity to the flexible portion 2. As a result, the flexible portion 2 is deformed into the shape stored therein, and the flexible portion 2 is pressed down. Therefore, by adjusting the temperature of the shape memory alloy foil constituting the flexible portion 2, the deformation of the flexible portion 2 can be controlled to control the flow rate of the fluid.

According to the present embodiment, since the flexible portion 2 itself is formed of a shape memory alloy foil, the manufacturing process becomes easier as compared with the embodiment shown in FIG.

[0065]

According to the first aspect of the present invention, there is provided a semiconductor substrate having a through hole and a projection serving as a valve seat provided near an opening of the through hole, and the projection of the semiconductor substrate is formed. And a flat-plate-shaped flexible portion disposed opposite to the surface with a predetermined gap width therebetween, and controlling the flow rate of the fluid by adjusting the gap width by displacing the flexible portion. Since such a boss structure does not exist, downsizing of the element, especially in the thickness direction, can be realized, alignment between the projection serving as the valve seat and the flexible portion serving as the valve body is facilitated, and the positioning margin is increased. It is not necessary to take it, and a larger displacement can be obtained compared to the boss structure for the same generated force, a small, normally open valve can be easily formed, and a wide range of flow control is possible. Semiconductor microvalve was able to be provided.

According to a second aspect of the present invention, in the semiconductor microvalve according to the first aspect, the gap width is formed by forming the flexible portion on the semiconductor substrate via a gap forming layer. The same effect as that of the first aspect can be obtained.

According to a third aspect of the present invention, in the semiconductor microvalve according to the first or second aspect, the flexible portion has a diaphragm shape. The effect is obtained.

According to a fourth aspect of the present invention, in the semiconductor microvalve of the first or second aspect, the flexible portion is disposed at a position corresponding to the opening of the through hole; Since the shape has a plurality of beams extending from the outer peripheral edge of the body, in addition to the effect of the invention described in claim 1 or 2, the force required to obtain the displacement of the flexible portion can be reduced. Further, the region removed for forming the beam can be used as the fluid outlet as it is, and there is no need to separately form the outlet.

According to a fifth aspect of the present invention, in the semiconductor microvalve according to any one of the first to fourth aspects, a metal layer is formed at a predetermined portion of the flexible portion, and a material for forming the metal layer is provided. 2. A bimetal is formed from a material forming the flexible portion and a material forming the flexible portion, and the flexible portion is displaced by a difference in thermal expansion coefficient between the metal layer and the material forming the flexible portion. The same effect as the invention according to any one of claims to 4 is obtained.

According to a sixth aspect of the present invention, in the semiconductor microvalve according to the fifth aspect, the metal layer is formed using aluminum or nickel and the flexible portion is formed using silicon. The same effect as that of the invention described in the fifth aspect can be obtained.

According to a seventh aspect of the present invention, in the semiconductor microvalve according to any one of the first to fourth aspects, a shape memory alloy wire is arranged at a predetermined position on the flexible portion, and By interposing a stopper facing the flexible portion through a spacer having the same thickness as the shape memory alloy wire above, by generating a force generated by deformation of the shape memory alloy wire in a predetermined direction by the stopper,
Since the flexible portion is displaced, the same effect as the invention according to any one of claims 1 to 4 can be obtained.

According to an eighth aspect of the present invention, in the semiconductor microvalve according to any one of the first to fourth aspects, a shape memory alloy foil is disposed on the flexible portion, and the shape memory alloy foil is deformed. Since the flexible portion is displaced using the force generated by the present invention, the same effect as the invention according to any one of claims 1 to 4 can be obtained.

According to a ninth aspect of the present invention, in the semiconductor microvalve according to any one of the first to fourth aspects, a shape memory alloy foil is used as a material of the flexible portion. Since the flexible portion is displaced by utilizing the deformation / restoration of the present invention, the same effect as the invention according to any one of claims 1 to 4 can be obtained.

According to a tenth aspect of the present invention, there is provided the method of manufacturing a semiconductor microvalve according to any one of the second to ninth aspects, wherein a predetermined portion is etched using Si-BO glass as the gap forming layer. By doing so, the gap width is formed, so that in addition to the effect of the invention according to any one of claims 2 to 9, the gap width can be formed with high accuracy, and it is small and normally open. A method of manufacturing a semiconductor microvalve capable of easily forming a mold-type valve and capable of controlling a flow rate in a wide range was provided.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a semiconductor microvalve according to one embodiment of the present invention.

FIG. 2 is a characteristic diagram illustrating distortion due to pressure of a flexible portion when the valve of the semiconductor microvalve according to the present embodiment is closed.

FIG. 3 is a schematic sectional view showing a semiconductor microvalve according to another embodiment of the present invention.

FIG. 4 is a schematic configuration diagram showing a semiconductor microvalve according to another embodiment of the present invention, (a) is a schematic sectional view, and (b) is a schematic plan view showing a state viewed from above. is there.

FIG. 5 is a schematic sectional view showing a manufacturing process of the semiconductor microvalve according to the present embodiment.

FIG. 6 is a schematic configuration diagram showing a semiconductor microvalve according to another embodiment of the present invention, wherein (a) is a schematic sectional view and (b) is a schematic plan view.

FIGS. 7A and 7B are schematic cross-sectional views of a semiconductor microvalve according to another embodiment of the present invention, in which FIG. 7A is a schematic cross-sectional view showing a state in which the microvalve is opened, and FIG. FIG. 3 is a schematic cross-sectional view showing a state in which the cover is folded.

FIG. 8 is a schematic sectional view showing a deformed state of the shape memory alloy wire according to the present embodiment.

9A and 9B are schematic cross-sectional views of a semiconductor microvalve according to another embodiment of the present invention, in which FIG. 9A is a schematic cross-sectional view showing a state in which the microvalve is opened, and FIG. FIG. 3 is a schematic cross-sectional view showing a state in which the cover is folded.

FIGS. 10A and 10B are schematic cross-sectional views of a semiconductor microvalve according to another embodiment of the present invention, in which FIG. 10A is a schematic cross-sectional view showing a state where the microvalve is opened, and FIG. FIG. 3 is a schematic cross-sectional view showing a state in which the cover is folded.

FIG. 11 is a schematic sectional view showing a semiconductor microvalve according to a conventional example.

FIG. 12 is a characteristic diagram showing a relationship between a pressure and a flow rate at the time of constant-speed exhaust of a semiconductor microvalve according to a conventional example.

FIG. 13 is a characteristic diagram showing a relationship between an input pressure, a gap width, and a flow rate of a semiconductor microvalve according to a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Silicon substrate 1a Through hole 1b Groove part 1c Projection part 1d Support part 2 Flexible part 2a Central part 2b Beam 2c Frame 3 Gap formation layer 3a Si-B-O glass 4 Outflow port 5 Protective film 6 Metal layer 7 Impurity diffusion layer 8 Spacer 9 Stopper 10 Shape memory alloy wire 11 Shape memory alloy foil 12 Silicon substrate 12a Valve body 12b Flexible part 12c Support part 13 Gap

Claims (10)

[Claims] 1. A semiconductor substrate having a through hole and a projection serving as a valve seat provided in the vicinity of an opening of the through hole, and a predetermined gap width between a surface of the semiconductor substrate on which the projection is formed. And a flat-plate-shaped flexible portion that is disposed to face the semiconductor micro-valve, wherein the flexible portion is displaced to control the flow rate of the fluid by adjusting the gap width. 2. The semiconductor microvalve according to claim 1, wherein said gap width is formed by forming said flexible portion on said semiconductor substrate via a gap forming layer. 3. The semiconductor microvalve according to claim 1, wherein the flexible portion has a diaphragm shape. 4. The valve device according to claim 1, wherein the flexible portion has a valve body disposed at a position corresponding to the opening of the through hole, and a plurality of beams extending from an outer peripheral edge of the valve body. The semiconductor microvalve according to claim 1 or 2, wherein 5. A metal layer is formed at a predetermined position of the flexible portion, and a material forming the metal layer and a material forming the flexible portion form a bimetal, and the metal layer and the flexible portion are formed. The semiconductor microvalve according to any one of claims 1 to 4, wherein the flexible portion is displaced depending on a difference in thermal expansion coefficient of a material composing (1). 6. The semiconductor microvalve according to claim 5, wherein said metal layer is formed using aluminum or nickel, and said flexible portion is formed using silicon. 7. A shape memory alloy wire is arranged at a predetermined position on the flexible portion, and a stopper is opposed to the flexible portion on the flexible portion via a spacer having the same thickness as the shape memory alloy wire. 5. The flexible portion according to claim 1, wherein the flexible portion is displaced by causing the stopper to generate a force generated by deformation of the shape memory alloy wire in a predetermined direction. 6. 4. The semiconductor microvalve according to claim 1. 8. A shape memory alloy foil is arranged on the flexible part, and a force generated by deformation of the shape memory alloy foil is used.
The semiconductor microvalve according to claim 1, wherein the flexible portion is displaced. 9. The method according to claim 1, wherein a shape memory alloy foil is used as a material of the flexible portion, and the flexible portion is displaced by utilizing deformation and restoration of the shape memory alloy foil. The semiconductor microvalve according to claim 1. 10. The method for manufacturing a semiconductor microvalve according to claim 2, wherein said gap forming layer is made of Si—BO glass, and a predetermined portion is etched to form said gap width. Forming a semiconductor microvalve.