KR19990041902A - Micro valve - Google Patents

Abstract

The present invention relates to a microvalve capable of obtaining a small size, a large displacement amount, and a large generating force by having a simple structure and good productivity by using a semiconductor manufacturing process by allowing a fluid flow to be interrupted by using a thin film-type suppression alloy. In particular, the substrate is formed with a space in which the diaphragm coupled to the upper surface can be bent deformation and the fluid inlet flows; A thin film type retaining alloy provided on the substrate to cover the diaphragm to vibrate the diaphragm while changing its shape according to temperature change; And a flow path plate provided at an upper portion of the substrate and communicating with the inlet, and having a flow path plate formed at one side of the flow path and having an outlet through which the fluid is intermittently discharged while being opened and closed by the vibration of the thin film-type storage alloy.

Description

Micro valve

The present invention relates to a microvalve, and more particularly, to control the flow of a fluid by using a phase change of a thin film-type retaining alloy, which can be made compact, and is simplified by manufacturing using a semiconductor thin film manufacturing process. Relates to a microvalve.

In general, a microvalve is a device that supplies an accurate amount of fluid by intermittent fluid flow and requires high reliability and miniaturization. It is mainly used in medicine, office automation, chemical analysis, industrial process adjustment, and the like, such as electrostatic force, piezoelectric element, and electromagnetic force.

FIG. 1 is based on the principle of heating and has an inlet 2 through which fluid flows in the lower part of the body 1, and an outlet 5 at the top. And the valve plate 3 for selectively opening and closing the inlet (2) is provided in the center of the body (1) and both sides of the upper surface of the valve plate 3 is provided with a heater (4) that generates heat when the current is energized. In the conventional microvalve configured as described above, the valve plate 3 vibrates in the up and down directions as the heater 4 is heated, and the fluid is discharged toward the outlet 5 through the inlet 2. In the discharging process, a certain amount of fluid is discharged in a pressurized state by the vibration of the valve plate 3.

However, since the valve plate 3 vibrates using thermal expansion due to heating, miniaturization is impossible to increase the displacement amount, and there is a problem in that the operating frequency due to the vibration of the valve plate 3 is low.

2 is provided with an inlet 2 and an outlet 5 communicating with each other on both sides of the body 1 in a manner using electrostatic force, and a valve plate 3 on the upper side of the body 1. Here, the valve plate 3 is composed of an electrostatic plate that generates electrostatic force. When static electricity is generated, the valve plate 3 vibrates up and down, and in this process, the fluid passes through the inlet 2 and the outlet 5 to a desired place. Discharged.

However, by applying a voltage to both sides of the valve plate by using the electrostatic force generated between the both ends there is a disadvantage that the amount of displacement is limited by the short phenomenon and difficult to miniaturize.

SUMMARY OF THE INVENTION The present invention was developed in view of the conventional problems, and an object of the present invention is to allow the flow of fluid to be interrupted by using a thin film-type suppression alloy, so that the structure is simple and the mass production is made by using a semiconductor manufacturing process. It is to provide a micro valve that can obtain a large displacement amount and a large generating force.

1 is a cross-sectional view of a conventional microvalve,

2 is a cross-sectional view of another conventional microvalve,

3A, 3B and 3C are cross-sectional views of the microvalve of the first embodiment of the present invention;

4A, 4B and 4C are cross-sectional views of the microvalve of the second embodiment of the present invention;

5A, 5B and 5C are cross-sectional views of the microvalve of the third embodiment of the present invention;

6A, 6B and 6C are cross-sectional views of the microvalve of the fourth embodiment of the present invention;

7 is a change curve of the internal residual stress of the third and fourth embodiments of the present invention.

<Description of Symbols for Main Parts of Drawings>

10: substrate 10a: flow path

11: space part 12: entrance

13: diaphragm 14: thin-film type memory alloy

15: Euro plate 16: Euro

17: exit

In order to achieve the above object, the present invention is a diaphragm coupled to the upper surface is a space portion that can be deflected and the substrate formed with the inlet through which the fluid flow; A thin film type retaining alloy provided on the substrate to cover the diaphragm to vibrate the diaphragm while changing its shape according to temperature change; And a flow path plate provided at an upper portion of the substrate and communicating with the inlet, and having a flow path plate formed at one side of the flow path and having an outlet through which the fluid is intermittently discharged while being opened and closed by the vibration of the thin film-type storage alloy.

According to the present invention, a thin film-type inhibitor alloy is formed on a substrate using a semiconductor thin film manufacturing process and a portion of the substrate is etched to form a space in which the thin film-type inhibitor alloy can vibrate, and the fluid flows by vibration of the thin film-type inhibitor alloy. This is an intermittent micro valve implemented.

The shape memory alloy is deposited on a substrate using a semiconductor thin film manufacturing process and then heat-treated to form a thin film-type memory alloy. Therefore, according to the deposition conditions, a flat shape or a fin shape is made in the mother phase. And it is restored by the residual compressive stress or elastic force of the diaphragm in martensite. Therefore, when the thin-film-type suppression alloy is heated, the thin-film-type suppression alloy becomes a matrix and tries to change into a flat / 휜 state, and during cooling, the fluid flows intermittently in this process because it is restored by the residual compressive stress or elastic force of the diaphragm.

The present invention has a simple structure and greatly increases the mass productivity by implementing the thin film mold suppression alloy through the semiconductor thin film manufacturing process and the substrate etching, and also it is possible to easily control the deformation amount by changing the magnitude of the residual compressive stress, thus greatly increasing the displacement amount. As a result, the area of the thin film-type storage alloy can be reduced. Therefore, it is possible to miniaturize the valve and use the thin film-type suppression alloy, which greatly reduces the power consumption during heating, the cooling time is very fast during cooling, and the residual vibration does not occur when returning to the bending deformation state. This becomes possible.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3A, 3B and 3C are cross-sectional views of the microvalve of the first embodiment of the present invention. The diaphragm 13 is formed in the substrate 10, and the diaphragm 13 covering the space 11 is provided on the substrate 10. In addition, an inlet 12 through which fluid flows is provided at one side of the substrate 10, and the thin film-type storage alloy 14 is deposited on the surface of the diaphragm 13. In addition, the flow path plate 15 covering the upper portion of the substrate 10 is provided. The flow path plate 15 is provided with a flow path 16 for guiding the flow of the fluid, and the flow path 16 communicates with the inlet 12. In addition, an outlet 17 is provided at one side of the flow path plate 15, and the outlet 17 is located directly above the thin film-type storage alloy 14.

The thin-film shape memory alloy 12 is a shape memory alloy that changes shape according to temperature and causes deformation. The material is mainly composed of titanium (Ti) and nickel (Ni), and its thickness is about 0.5 μm to 5 It is about a micrometer. The diaphragm 13 has a positive thickness of 0.3 μm to 5 μm, and the size of the thin-film-shaped suppression alloy 14 and the diaphragm 13 is 100 μm to 5000 μm, and the material of the substrate 10 is a single crystal silicon wafer or glass. Or polymers, metals, and the like.

The thin film shape memory alloy 14 composed of the shape memory alloy has a directionality according to the manufacturing method. The present invention relates to a one-way thin film shape memory alloy. The diaphragm 13 is formed on the surface of the substrate 10 made of a material such as silicon, and the thin film-type storage alloy 14 is deposited on the surface of the diaphragm 13. Deposition is mainly the method of sputter-deposition and laser ablation.

If the crystallization is performed by heat treatment at a constant temperature for a certain time, the bending deformation is caused by the residual tensile stress at the parent phase end temperature of about 50 ~ 90 ℃. Thereafter, the mother phase becomes martensite while cooling to a martensite finish temperature of about 40 ° C. to 70 ° C. In addition, when the lower portion of the thin film storage alloy 12 is directly etched, a space 11 is formed in the substrate 10 formed of a silicon wafer, and at this time, the diaphragm 13 is exposed toward the space 11 and the thin film storage alloy ( When 14) is martensite, bending deformation is caused by residual compressive stress of the diaphragm 13.

The thin film-shaped retaining alloy 14 of the first embodiment of the present invention configured as described above is continuously changed in phase with temperature change, and the outlet 17 is continuously opened and closed by deformation in this process. As shown in FIG. 3A, the thin film type retaining alloy 14 is kept in a 휜 state by the residual compressive stress of the diaphragm 13 in an initial state in which the thin film type forming alloy 14 is not heated, and the outlet 17 is opened. 3B, when a current is applied to the thin film-type suppression alloy, it is generated by the self-resistance of the thin film-type suppression alloy 14, and when it is heated above the set temperature, it unfolds while changing to a parent phase. When the thin film-shaped retaining alloy 14 is heated, it is deformed to the original flat state, and in this process, the diaphragm 13 and the thin film-shaped retaining alloy 14 are deformed upward and the outlet 17 is blocked.

In addition, as shown in FIG. 3C, when the current is cut off, the thin film-shaped retaining alloy 14 is lowered below the set temperature and is restored to its original state by the residual compressive stress of the diaphragm 13. The diaphragm 13 is deflected and the outlet 17 is opened. Therefore, while the heating and cooling of the thin-film-type storage alloy 14 occur continuously, the fluid flows intermittently.

4A, 4B and 4C are cross-sectional views of the microvalve of the second embodiment of the present invention. An inlet 12 and a space 11 are formed in the substrate 10, and a flow path 10a connecting the inlet 12 and the space 11 is formed at the bottom. In addition, the diaphragm 13 is provided on the upper portion of the substrate 10 to cover the space 11, the diaphragm 13 is deflected by the residual compressive stress to block the outlet 17 to be described later. Then, the thin film-type storage alloy 14 is provided on the surface of the diaphragm 13. In addition, a bottom surface of the substrate 10 is provided with a flow path plate 15 covering the space portion 11 and an outlet 17 opened and closed by the diaphragm 13.

According to the second embodiment of the present invention configured as described above, when the current is applied, the thin film-shaped retaining alloy 14 is heated by its own resistance and is flexibly deformed to its original flat state, and the outlet 17 is opened while the diaphragm 13 is flexurally deformed together. do. When the current is blocked in the thin film-type storage alloy 14, the cooling is restored to its original state by the residual compressive stress of the diaphragm 13, and the outlet 17 is closed. In the above process, while the outlet 17 is continuously interrupted, the flow of the fluid is controlled.

5A, 5B and 5C are cross-sectional views of the microvalve of the third embodiment of the present invention, in which the same components as those of the first embodiment will be described with the same reference numerals. In the third embodiment of the present invention, there is no residual compressive stress in the diaphragm 13. Therefore, the diaphragm 13 and the thin film type retaining alloy 14 are clogged in the unfolded state in the initial state in which the thin film type retaining alloy 14 is not heated, and the thin film type retaining alloy 14 becomes a matrix when heated. It is deflected downward by its residual tensile stress and the outlet 17 is opened and the fluid is discharged intermittently as the above process is repeated.

6A, 6B and 6C are cross-sectional views of the microvalve of the fourth embodiment of the present invention, in which the same components as those of the second embodiment will be described with the same reference numerals. In the fourth embodiment of the present invention, there is no residual compressive stress in the diaphragm 13. Therefore, the diaphragm 13 and the thin film type retaining alloy 14 are in an unfolded state in the initial state in which the thin film type retaining alloy 14 is not heated, and the outlet 17 is in an open state. Then, when heated to the mother phase, the thin film-shaped retaining alloy 14 is bent downward by the residual tensile stress of its own, and at the same time, the outlet 17 is blocked, and this process is repeated to control the fluid intermittently.

As described above, according to the present invention, the outlet is selectively opened and closed by a combination of the thin-film-type suppression alloy and the diaphragm to intermittently discharge the fluid. In addition, since the thin film-type suppression alloy is manufactured through the semiconductor thin film manufacturing process, the productivity can be improved and the thickness can be reduced, thereby increasing the operating speed and controlling the fluid accurately.

Claims (18)

A substrate having a space in which a diaphragm coupled to an upper surface of the diaphragm can be bent and a fluid inlet flows; A thin film type retaining alloy provided on the substrate to cover the diaphragm to vibrate the diaphragm while changing its shape according to temperature change; And And a flow path plate provided at an upper portion of the substrate and communicating with the inlet, and having a flow path plate at one side of the flow path which is opened and closed by the vibration of the thin film-type suppression alloy to discharge the fluid intermittently. The method of claim 1, wherein when the thin film-shaped retaining alloy is cooled to be martensite, the outlet is opened while being warped by the residual compressive stress of the diaphragm. And the thin film-shaped retaining alloy is heated to form a matrix, and is unfolded in a flat state by deformation, and the outlet is closed while the diaphragm is unfolded together. The method of claim 1, wherein when the thin film-shaped retaining alloy is cooled to be martensite, the outlet is closed while being unfolded by the elastic force of the diaphragm. And when the thin film-shaped retaining alloy is heated to form a base, the outlet valve is bent due to residual tensile stress and the diaphragm is bent together to open the outlet. The micro-valve according to claim 1, wherein the thin-film-type storage alloy is a shape memory alloy composed mainly of titanium (Ti) and nickel (Ni). The microvalve of claim 1, wherein the thin-film-type retaining alloy has a thickness of 0.5 μm to 5 μm. The microvalve of claim 1, wherein the substrate is made of silicon. The microvalve of claim 1, wherein the substrate is made of glass. The microvalve of claim 1, wherein the diaphragm has a thickness of about 0.3 μm to 5 μm. The microvalve according to claim 2 or 3, wherein the mother phase end temperature is about 50 ° C to 90 ° C, and the martensite end temperature is about 40 ° C to 70 ° C. A substrate having a space in which a diaphragm coupled to an upper surface of the diaphragm can be bent and an inlet through which fluid flows, and a passage connecting the inlet and the space to a bottom surface thereof; A thin film type retaining alloy provided on the substrate to cover the diaphragm to vibrate the diaphragm while changing its shape according to temperature change; And And a flow path plate provided at a lower portion of the substrate and having an outlet at one side of the flow path opened and closed by the vibration of the thin-film-type retaining alloy to discharge fluid intermittently. The method of claim 10, wherein when the thin-film-shaped retaining alloy is cooled to martensite, the outlet is closed while bending by the residual compressive stress of the diaphragm, And when the thin film-shaped retaining alloy is heated and spreads out in a flat state by deformation, and the diaphragm is expanded together, the outlet is opened. The method according to claim 10, wherein when the thin film-shaped retaining alloy is cooled to be martensite, the outlet is opened while being unfolded by the elastic force of the diaphragm. And when the thin film-shaped retaining alloy is heated to form a shape, the micro valve is flexurally deformed by residual tensile stress and the outlet is closed while the diaphragm is flexurally deformed together. The microvalve according to claim 10, wherein the thin-film-type storage alloy is a shape memory alloy composed mainly of titanium (Ti) and nickel (Ni). The microvalve of claim 10, wherein the thin-film-type retaining alloy has a thickness of 0.5 μm to 5 μm. The microvalve of claim 10, wherein the substrate is made of silicon. The microvalve of claim 10, wherein the substrate is made of glass. The microvalve of claim 10, wherein the diaphragm has a thickness of about 0.3 μm to 5 μm. 13. The microvalve according to claim 11 or 12, wherein the mother phase end temperature is about 50 ° C to 90 ° C and the martensite end temperature is about 40 ° C to 70 ° C.