JPH0658450A - Solenoid-driven small valve - Google Patents

Abstract

PURPOSE:To provide a solenoid-driven small valve, miniaturized in driving mechanical parts, capable of driving a very minute flow rate less than the specified value stably at high speed. CONSTITUTION:This valve is made up of installing a base plate consisting of a cover part 2 of a valve made of a silicon 1 and nickel-iron alloy film or nitriding silicon film valve with a through hole in the central part, a double holding beam 3 consisting of a nickel-iron alloy film of such a structure as uncontacted with this through hole on a surface of this base plate, and a driving coil 4 set up at the outside.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetically actuated small valve which is advantageous for controlling a minute flow rate of a reaction gas used in various semiconductor device manufacturing processes.

[0002]

CV in the manufacturing process of semiconductor devices
The D method (chemical vapor deposition method) plays an important role as a process for producing various thin films, and high performance is required for the small valve used for controlling the flow rate of the reaction gas. With a conventional small valve that uses electromagnetic force, high accuracy cannot be obtained because the main part is manufactured by machining, and the flow rate is a minimum of 10
It was difficult to operate a minute flow rate stably, for example, it could be controlled only up to about 0 μl (microliter) / min.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and further miniaturizes the drive mechanism so that a very small flow rate of 10 μl / min or less can be stably driven at high speed. An object is to provide an electromagnetically actuated small valve.

[0004]

The electromagnetically actuated small valve of the present invention has high dimensional accuracy obtained by integrally forming the main components of the valve on a silicon substrate by photolithography technology and thin film technology. The double-supported beam structure enables high-speed response.

[0005]

According to the present invention, when the drive coil is operated, the doubly supported beam made of the soft magnetic material is displaced by the magnetic field gradient, and the polarity of the current to the drive coil is changed to form a through hole formed on the silicon substrate. It is intended to open and close the portion of the lid having.

[0006]

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

FIG. 1A is a top view of a main part of an electromagnetically driven small valve according to an embodiment of the present invention, and FIG. 1B is a sectional view of the same. That is, 1 is silicon having a through hole in the central portion, 2 is a valve lid portion made of a nickel iron alloy film or a silicon nitride film, and 3 is a soft magnetic nickel iron alloy film having a structure that does not contact the through hole of silicon 1. A doubly supported beam,
Reference numeral 4 is a drive coil arranged outside, and 5 is a displacement direction of the doubly supported beam. The operation of this valve is such that when a current is applied to the drive coil 4, a magnetic field gradient is formed in the peripheral portion of the coil 4, and by disposing the doubly supported beam 3 at a position where the magnetic field gradient is the largest, the beam 3 portion is magnetized and a large displacement occurs. Utilizing the fact that the amount is obtained, the through hole is closed by being pushed down to the lid portion 2 of the valve having the conical through hole arranged in the lower part of the both-supported beam 3. Further, by switching the direction of the current applied to the coil 4, the beam 3 is displaced as shown by 5 in the figure, and the valve opening / closing operation is performed.

FIG. 2 is a cross-sectional view of another embodiment of the present invention, which is an electromagnetically driven small valve in which an orifice plate and a coil are provided before and after the small valve of FIG. 1, in which 1 is silicon and 2 is a nickel-iron alloy film. Alternatively, a valve lid portion 3 made of a silicon nitride film, 3 are both-supported beams made of a soft magnetic nickel iron alloy film, 4a, 4b.
Is a drive coil disposed outside, and 6a and 6b are orifice plates made of silicon. Orifice plates 6a, 6b
It has been found that the provision of the above is effective for the stable operation of the valve part, such as preventing the invasion of impurity particles which may damage the valve part. Further, it was found that the coils 4a and 4b are arranged in front of and behind the orifice plates 6a and 6b, respectively, so that the opening / closing operation of the both-supported beam 3 can be performed with high efficiency.

FIG. 3 is a cross-sectional view of an electromagnetically driven small valve in which the external drive coil portion of FIG. 2 is integrated with an orifice plate by a thin film coil according to another embodiment of the present invention.
Reference numeral 2 is a valve lid portion made of a nickel iron alloy film or silicon nitride film, 3 is a doubly supported beam made of a soft magnetic nickel iron alloy film, and 6a and 6b are orifice plates made of silicon,
Reference numerals 7a and 7b are thin film coils. The thin film coils 7a and 7b made of a gold or copper film were formed by a photolithography technique and a thin film technique such as sputtering and etching. By integrating the coils 7a and 7b and the orifice plates 6a and 6b, the size can be further reduced.

FIG. 4A is a top view of an electromagnetically driven small valve using a swastika-type double-supported beam according to another embodiment of the present invention.
(B) is also a cross-sectional view, 1 is silicon, 2 is a valve lid part made of a nickel-iron alloy film or a silicon nitride film, 3
Reference numeral 0 is a double-supported beam of a nickel-iron alloy film of a soft magnetic material having a conical shape in the central part. The shape of the swollen double-supported beam 30 of FIG. 4A is about 300 μm square, and the width of the beam is about 20 μm.
The thickness of the beam was about 1 to 5 μm. The central portion thereof has a conical shape that matches the shape of the lower lid portion 2. All fabrication methods used photolithography technology and thin film technology. No particles are generated because the constituent materials are two kinds of silicon single crystal and nickel iron alloy or silicon nitride and are extremely stable materials. Double-supported beam 3
Since 0 is a minute structure, high-speed response is possible and excellent stability is obtained. The electromagnetically driven small valve shown in FIG. 4 was operated by an external drive coil. Drive coil voltage 5
When the test was performed at V and a driving current of 60 mA, the primary resonance frequency was about 5 KHz and the beam displacement was about 3 μm. Moreover, when an experiment was conducted using a rare gas (argon), it was found that
A flow rate of 1 to 10 μl / min could be confirmed by a leak detector. It was found that the high-order resonance point of the swollen double-supported beam 30 is capable of high-speed response at 30 KHz. Further, it was found that the gap between the doubly supported beam 30 and the lid portion 2 was at most about 1 μm and the displacement was sufficient, so that the opening / closing operation of the valve portion could be realized.

[0011]

As described above, according to the present invention,
It is possible to realize a small valve for controlling an extremely minute flow rate that can control a flow rate of 0.1 to 10 μl / min with high accuracy.

[Brief description of drawings]

FIG. 1A is a top view of a main portion of an electromagnetically driven small valve according to an embodiment of the present invention, and FIG. 1B is a sectional view of the same.

FIG. 2 is a cross-sectional view of an electromagnetically driven small valve in which an orifice plate and a coil are provided before and after the small valve of FIG. 1 according to another embodiment of the present invention.

FIG. 3 is a sectional view of an electromagnetically driven small valve in which the external drive coil portion of FIG. 2 is integrated with an orifice plate by a thin film coil according to another embodiment of the present invention.

FIG. 4A is a top view of an electromagnetically driven small valve using a swastika double-supported beam according to another embodiment of the present invention, and FIG. 4B is a sectional view of the same.

[Explanation of symbols]

1 ... Silicon, 2 ... Valve lid part made of nickel iron alloy film or silicon nitride film, 3 ... Doubly supported beam made of nickel iron alloy film, 4, 4a, 4b ... Drive coil, 5 ... Displacement direction of doubly supported beam , 6a, 6b ... Orifice plate, 7a, 7b
… Thin film coils.

Claims (4)

[Claims] 1. A substrate made of silicon having a through hole in the center and a nickel-iron alloy film or a silicon nitride film,
An electromagnetically actuated small valve, comprising: a double-supported beam made of a nickel-iron alloy film having a structure that does not come into contact with the through hole, and a drive coil arranged outside, on the surface of the substrate. 2. The electromagnetically actuated small valve according to claim 1, wherein the doubly supported beam has a swastika beam structure having a conical center portion. 3. An electromagnetically actuated small valve according to claim 1, wherein an orifice plate made of silicon having a through hole in the central portion is provided before and after the substrate and the both-supported beam. 4. An electromagnetically actuated small valve according to claim 3, wherein a coil of a gold or copper thin film is integrated around the through hole of the orifice plate.