KR100969579B1 - Movement detecting device of electrical conductor, accelerometer having the same and method for producing movement detecting device - Google Patents

Abstract

PURPOSE: A movement sensing device of a liquid conductor, an accelerometer thereof, and a manufacturing method thereof are provided to easily control a design value. CONSTITUTION: A guide part(230) stores a liquid conductor and guides the movement of the conductor. An electric wiring part(240) comprises a plurality of electric routes crossing the guide part and are electrically connected to one among the electric routes by the liquid conductor. A detecting part is connected to an electric wiring part. The detecting part detects the movement of the liquid conductor by using the change of the electric route.

Description

MOVEMENT DETECTING DEVICE OF ELECTRICAL CONDUCTOR, ACCELEROMETER HAVING THE SAME AND METHOD FOR PRODUCING MOVEMENT DETECTING DEVICE}

The present invention relates to a sensing device capable of measuring an inertial force or acceleration, and a manufacturing method thereof.

An accelerometer is a device that measures the rate of change of an object (acceleration). It can't measure acceleration directly, so it measures the force applied to the suppressor held above the proof mass in the accelerometer.

Fig. 9 shows the configuration of an accelerometer using a commonly used solid standard mass, which is composed of a solid proof mass 11 and a hinge 12, so that an external input (e.g., Input acceleration is detected from the movement and deformation of standard mass due to external force). In other words, the inertia force applied to the standard mass, the magnitude of the external input, or the acceleration measured by the accelerometer are calculated from the movement of the standard mass. In this way, it is implemented by a device for detecting the movement of the mass due to inertia forming the driving principle of the accelerometer. In addition, the movement detection device of the mass is not only an accelerometer but also has high utility in other technical fields.

However, in order to manufacture high-performance motion detectors or accelerometers, complex structures and advanced manufacturing techniques are required, and complex circuits are required in signal processing. Accordingly, a device for detecting mass movement and an accelerometer having the same may be considered.

One object of the present invention is to provide a motion sensing device driven in a form different from the prior art, an accelerometer having the same, and a manufacturing method of the motion sensing device.

Another object of the present invention is to provide an accelerometer with a simpler structure and easy to change the design value.

An apparatus for detecting movement of a liquid conductor according to an embodiment of the present invention for realizing the above object includes: a guide portion formed to receive a liquid conductor and to guide movement of the liquid conductor, and to cross the guide portion; An electrical wiring part having a plurality of electrical paths, the electrical paths being disconnected from each other in the guide part, and at least one of the electrical paths being electrically connected by the liquid conductor; And a detector configured to detect movement of the liquid conductor using a change in the electrically connected electrical path.

According to an example related to the present invention, the guide part includes a recess part and a cover part. The recess is recessed on one surface of the sensing body to form a guide space of the guide part. The cover part is formed to cover one surface of the main body so as to close the opening of the recess part. The electrical paths are arranged parallel to each other in the cover part.

According to another example related to the present invention, the surfaces defining the recessed portions are made of a non-wetting surface. The surface defining the recess portion is formed of an uneven surface. The liquid conductor may be a liquid metal droplet.

According to another example related to the present invention, the guide parts respectively extend in both directions opposite to each other at the center, and are formed to gradually narrow in both directions from the center. The detector calculates a relative position with respect to the center of the liquid conductor using the electrically connected electrical path, and calculates an inertial force applied to the liquid conductor or an acceleration of the sensing device body from the relative position.

In addition, the accelerometer according to another embodiment of the present invention includes a movement sensing device and an acceleration calculator of the liquid conductor. An acceleration calculator is connected to the movement sensing device to calculate the acceleration by using the movement of the liquid conductor. The electrical paths may be spaced apart from each other at predetermined intervals, and the minimum change in the detectable acceleration may be set by the predetermined interval.

In addition, the present invention discloses a method for manufacturing a movement sensor in order to realize the above object. A method of manufacturing a movement sensing device includes: masking at least a portion of photosensitive glass such that an unmasked portion forms a pattern, irradiating light onto the photosensitive glass so that the pattern is exposed to light, and the pattern is photosensitive. Etching the photosensitive glass to be recessed into the interior of the glass, injecting a liquid conductor into the recessed portion to move the liquid conductor along the recessed portion, and a plurality of electrical paths disconnected from each other. Covering the recessed portion using a cover provided. The method of manufacturing the movement sensing device may include heat treating the photosensitive glass to change a physical property of the pattern exposed to the light.

The movement sensing device of the liquid conductor, the accelerometer having the same, and the manufacturing method of the movement sensing device according to the present invention configured as described above may be configured in a simpler structure by detecting the movement of the liquid conductor. In addition, this enables real-time output such as inertial force or acceleration without a separate complicated circuit.

In addition, the present invention can be made easier to change the design value by changing the shape of the guide portion or the distance between the electrical paths. In addition, through this, a movement detecting apparatus that can be utilized in various technical fields may be implemented.

In addition, the present invention provides a movement sensing device of the liquid conductor that is easy to move the liquid conductor at a lower cost by forming a guide portion using the photosensitive glass and at the same time having a fine roughness on the inner surface of the guide portion.

Hereinafter, a movement detecting apparatus for a liquid conductor, an accelerometer having the same, and a manufacturing method of the movement detecting apparatus according to the present invention will be described in detail with reference to the accompanying drawings. In the present specification, the same or similar reference numerals are assigned to the same or similar configurations in different embodiments, and the description thereof is replaced with the first description. As used herein, the singular forms "a", "an" and "the" include plural forms unless the context clearly indicates otherwise.

1 is a conceptual diagram illustrating an accelerometer 100 according to an embodiment of the present invention.

As shown, the accelerometer 100 includes a movement sensing device 200 and an acceleration calculating unit 110 of the liquid conductor.

The movement sensing device 200 of the liquid conductor is mounted on an object (not shown) for measuring acceleration, and the liquid conductor 201 is formed to move in accordance with the speed change of the object. Specifically, when the speed of the object changes, the movement detecting apparatus 200 is accelerated in the direction of the arrow, and the liquid conductor 201 is moved in the direction opposite to the acceleration direction due to the inertia acting on the liquid conductor 201.

The movement detecting apparatus 200 may include, for example, a main body 210 that defines a guide space in which the liquid conductor 201 may move, and a detector 220 that detects that the liquid conductor 201 has moved in the guide space. It is provided.

The main body 210 may be made of a microminiature so that the size of the guide space is in micro units, through which the accelerometer 100 may be a micro accelerometer.

The acceleration calculating unit 110 is connected to the movement detecting apparatus 200 to calculate the acceleration using the movement of the liquid conductor 201. That is, the accelerometer 100 measures the acceleration applied through the position of the liquid conductor 201 moving in the guide space. The accelerometer 100 has a simpler structure as compared to a conventional solid proof mass type accelerometer. Have

The accelerometer 100 may be formed in the form of a semiconductor package. For example, the body 210 and the detector 220 of the movement detecting apparatus 200 may be formed of one chip, and the acceleration calculator 110 may be formed of one chip. It can be composed of a chip. However, the present invention is not limited thereto, and the detector 220 and the acceleration calculator 110 may be implemented in one chip. In addition, the accelerometer 100 may be configured to convert the acceleration calculated by the acceleration calculating unit 110 into a digital or analog signal and output it to the outside.

Hereinafter, the movement detecting apparatus 200 of FIG. 1 will be described in more detail with reference to FIGS. 2A to 4B.

2A and 2B are respectively a perspective view and an exploded view of the movement sensing device 200 of the liquid conductor shown in FIG.

The body 210 of the movement detecting apparatus 200 includes a case (casing, housing, cover, etc.) forming an appearance. In this embodiment, the case may be divided into a base case 211 and a cover case 212. The base case 211 and the cover case 212 may be coupled to each other through bonding, and an internal space is formed between the base case 211 and the cover case 212. The cases 211 and 212 may be formed of, for example, a synthetic resin, a semiconductor wafer, photosensitive glass, or the like.

Referring to the drawings, the movement detecting apparatus 200 includes a guide unit 230 and the electrical wiring unit 240.

The guide part 230 receives the liquid conductor 201 and is formed to guide the movement of the liquid conductor 201. The guide part 230 includes a recess 231 and a cover 232.

The recess 231 is recessed in one surface of the sensing device main body 210 to form a guide space of the guide unit 230. Referring to FIG. 2B, the recess 231 extends long in one direction from one surface of the base case 211, is narrower in width than the length, and is formed to block both ends in the longitudinal direction. The liquid conductor 201 accommodated in the recess 231 flows along the guide space by inertia.

The liquid conductor 201 is formed of liquid metal droplets. Liquid metal droplets are metals having electrical conductivity and are materials that maintain a liquid state at room temperature. In particular, the liquid metal droplets may be formed in a micro size, and are maintained as spherical droplets because of their large surface tension. The liquid metal droplet may be used as long as it is a liquid metal having electrical conductivity, and may be mercury, for example.

Surfaces defining the recessed portion 231 may be made of a non-wetting surface or form an uneven surface. Surfaces defining the recessed portion 231 refer to the bottom and side surfaces of the recessed portion 231, ie the inner surfaces of the guide portion 230. Preferably, the inner surfaces of the guide portion 230 are formed of a non-wetting surface having fine unevenness 231a (see FIG. 8D) to allow the liquid conductor 201 to flow more easily. The area in which the liquid conductor 201 is in contact with the inner surfaces of the guide part 230 is reduced by the fine unevenness 231 a, and thus the sensitivity of the acceleration detection in the accelerometer 100 (see FIG. 1) may be increased. have.

As a method of processing the inner surfaces of the guide part 230 to a non-wetting surface, a method of forming fine concavities and convexities at the same time as manufacturing a flow path using photosensitive glass may be used. However, the present invention is not limited thereto, and the non-wetting surface may be formed through a chemical method such as Teflon coating or SAM coating and a physical method using a fine particle injector.

The cover part 232 is formed to cover one surface of the base case 211 to block the opening of the recess 231. In detail, the cover part 232 is disposed on a surface of the cover case 212 that covers the base case 211, and together with the recess part 231, forms a guide space of the liquid conductor 201 as a closed space. .

The electrical wiring part 240 includes a plurality of electrical paths 241 formed to cross the guide part 230, and the electrical paths 241 are disconnected from each other in the guide part 230, respectively. At least one of the fields 241 is formed to be electrically connected by the liquid conductor 201.

The electrical paths 241 are arranged parallel to each other in the cover portion 232. The electrical paths 241 are exposed at the guide portion 230 so as to be electrically conductive when the liquid conductor 201 is disposed at each disconnected portion.

The electrical paths 241 may be electrode connecting lines connecting the electrodes, and the disconnected portions of the electrical paths 241 serve as a pair of connecting terminals facing each other, and the pair of connecting terminals face each other. Spaced at predetermined intervals.

For example, when power is supplied to the electrical paths 241, a pair of connection terminals are electrically connected by the liquid conductor 201, through which electrodes are connected so that a current flows in the electrical path. At this time, when the liquid conductor 201 is moved, a pair of connection terminals connected to each other is changed. The detection unit 220 (refer to FIG. 1) is connected to the electrical wiring unit 240, and detects the movement of the liquid conductor 201 using the change of the electrically connected electrical path.

The movement of the liquid conductor 201 may be converted into acceleration by the acceleration calculation unit 110 (see FIG. 1). As described above, the fine liquid metal droplets may be converted into a standard mass (using the liquid detection device 200 of the liquid conductor). A micro accelerometer that can be used as a proof mass can be implemented.

3A and 3B are conceptual views showing the position of the liquid conductor 201 before and after the acceleration is applied, respectively, and FIGS. 4A and 4B respectively detect the position of the liquid conductor 201 using the electrical paths 241. These are conceptual diagrams showing the principle of how to do this. 3A to 4B are diagrams showing a plan view and a front view of the guide unit 230, respectively.

The guide portion 230 extends in both directions opposite to each other at the center 233. Guide portion 230 is made to be symmetrical in both directions with respect to the center 233, through which the change in the liquid conductor 201 according to the distance moved in both directions from the center can be the same.

The guide portion 230 is formed to gradually narrow in both directions from the center 233. The liquid conductor 201 positioned at the center as shown in FIG. 3A moves along the guide portion 230 as shown in FIG. 3B when the inertial force is applied, and the shape is deformed by the external force received by the guide portion 230. do. When the inertial force is removed, the liquid conductor 201 is returned to the wide center 233 by the surface tension.

4A and 4B, when the liquid conductor 201 located at the center 233 moves, an electrically connected electric path (specifically, an electric path indicated by a hollow circle) is changed. The detector 220 (refer to FIG. 1) calculates a relative position with respect to the center 233 of the liquid conductor 201 using an electrically connected electrical path, and inertial force or body applied to the liquid conductor 201 from the relative position. The acceleration of 210 is calculated.

5A to 5D are conceptual views illustrating modifications of the guide unit of FIG. 2A according to design values of sensing accelerations, respectively, and FIGS. 6A and 6B are views in which a minimum change in the detectable acceleration is set by the distance between electric paths, respectively. Are conceptual diagrams.

The accelerometer or the movement detecting apparatus according to the present invention may adjust the dynamic range by adjusting the inclination and the overall length of the guide unit 330 as shown in FIG. 5B. As shown in FIG. 5B, when the inclination is smaller than the guide part 230 of FIG. 5A and the overall length is longer, the measurement range may be increased. The inclination of the guide portion 230 means a proportional value of decreasing width from the center 233 (see FIG. 3B).

As shown in FIG. 5C, the convex shape of the guide part 430 facilitates the movement of the liquid conductor 401, thereby enabling more sensitive measurement. As shown in FIG. 5D, the concave shape of the guide part 530 is concave. The force (restoration force due to surface tension) that the liquid conductor 501 receives increases, so that the measurement range can be increased.

6A and 6B, the electrical paths 641a and 641b may be spaced apart from each other at predetermined intervals, and a minimum change in the detectable acceleration may be set by the predetermined intervals. That is, the accelerometer or the movement sensing device may change the sensitivity by adjusting the interval of the electrode paths. Reducing the spacing of the electrode paths reduces the minimum change in acceleration that can be detected, thus increasing sensitivity.

In addition, in order to increase the sensitivity of the acceleration detection, as described above with reference to FIGS. 2A and 2B, the inner surfaces of the guide part 230 may have non-wetting characteristics. Hereinafter, referring to FIGS. 7 to 8D, a method of manufacturing the movement detecting apparatus capable of forming the inner surfaces of the guide part 230 as non-wetting surfaces will be described.

FIG. 7 is a flowchart illustrating a method of manufacturing an apparatus for detecting a movement of a liquid conductor according to the present invention, and FIGS. 8A to 8D illustrate a process of forming a non-wetting surface having a high contact angle at the same time as the guide part is formed by the manufacturing method of FIG. 7. Are conceptual diagrams.

Referring to FIG. 7, in the method of manufacturing the movement sensing apparatus, first, at least a portion of the photosensitive glass is masked so that a portion which is not masked forms a pattern (S100).

For example, as shown in FIG. 8A, the main body 710 is formed of photosensitive glass, the guide part 730 is exposed to the outside, and other areas of the main body 710 except for the guide part 730 (see FIG. 8D) are masked ( mask, 760).

Next, the photosensitive glass is irradiated with light to expose the pattern (S200), and the photosensitive glass is heat-treated to change the physical properties of the pattern exposed to the light (S300).

For example, as shown in FIG. 8B, the mask portion 760 is first exposed to light of a wavelength band where the photosensitive glass reacts sensitively. When the heat treatment is performed at a high temperature, the portion of the guide portion 730, that is, the pattern portion 740 exposed to light, changes the properties of the material, so that the etching ratio of the etching solution is different with respect to the portion not exposed to the light.

Next, the photosensitive glass is etched so that the pattern is recessed into the photosensitive glass (S400).

As illustrated in FIGS. 8C and 8D, when the photosensitive glass is etched with an etchant, a guide part 730 is formed according to a difference in etching ratio, and fine unevenness 731a is formed on the surface to be etched. The shape and size of the fine iron can be adjusted according to the time when the pattern portion is exposed to light, the heat treatment temperature and time, or the ratio of the etchant.

Finally, a liquid conductor is injected into the recessed portion to move the liquid conductor along the recessed portion (S500), and the recessed portion is covered using a cover having a plurality of electrical paths disconnected from each other. (S600).

For example, the manufacturing process is completed by inserting the fine liquid metal droplets into the recessed portions, covering and bonding the cover case in which the electrical path is disposed.

As described above, as in the manufacturing method related to the present invention, by using the photosensitive glass to form a fine roughness at the same time as the guide portion fabrication, thereby making the sensing device more simply.

The movement sensing device of the liquid conductor as described above, the accelerometer and the manufacturing method of the movement sensing device having the same are not limited to the configuration and method of the embodiments described above, the embodiments are each embodiment so that various modifications can be made All or some of these may optionally be combined.

1 is a conceptual diagram illustrating an accelerometer according to an embodiment of the present invention.

2A and 2B are respectively a perspective view and an exploded view of the movement detecting device of the liquid conductor shown in FIG.

3A and 3B are conceptual views showing the position of the liquid conductor before and after the acceleration is applied, respectively.

4A and 4B are conceptual views illustrating the principle of sensing the position of a liquid conductor using electrical paths, respectively.

5A to 5D are conceptual views illustrating modified examples of the guide unit according to design values of sensing accelerations, respectively.

6A and 6B are conceptual views illustrating a state in which a minimum change in the acceleration that can be detected by an interval of electric paths is set.

7 is a flow chart showing a manufacturing method of a movement sensing device of a liquid conductor according to the present invention.

8A to 8D are conceptual views illustrating a process of forming a non-wetting surface having a high contact angle at the same time as the formation of the guide part by the manufacturing method of FIG. 7.

9 is a schematic diagram of an accelerometer using a resonant solid standard mass according to the prior art;

Claims (12)

A guide part accommodating a liquid conductor and formed to guide the movement of the liquid conductor; A plurality of electrical paths formed to cross the guide part, the electrical paths being disconnected from each other in the guide part, and at least one of the electrical paths formed to be electrically connected by the liquid conductor part; And And a detection unit connected to the electrical wiring unit and detecting a movement of the liquid conductor using a change in the electrically connected electrical path. The method of claim 1, The guide unit, A recess part recessed in one surface of a sensing body to form a guide space of the guide part; And And a cover part covering one surface of the main body to block the opening of the recess part. The method of claim 2, And the electrical paths are arranged parallel to each other in the cover part. The method of claim 2, Surfaces defining the recess portion is a movement sensing device of the liquid conductor, characterized in that consisting of a non-wetting surface. The method of claim 2, The surface defining the recess portion is a movement sensing device of the liquid conductor, characterized in that the concave-convex surface. The method of claim 1, The guide portion extends in both directions opposite to each other in the center, the movement sensing device of the liquid conductor, characterized in that the width gradually narrows from the center in both directions. The method of claim 6, The detection unit, Calculate a relative position with respect to the center of the liquid conductor using the electrically connected electrical path, and calculate an inertial force applied to the liquid conductor or an acceleration of the sensing device body from the relative position Movement detection device. The method of claim 1, And the liquid conductor is a liquid metal droplet. Movement sensing device of the liquid conductor; And It is connected to the movement detecting device, and includes an acceleration calculation unit for calculating the acceleration using the movement of the liquid conductor, The movement detecting device, A guide part accommodating a liquid conductor and formed to guide the movement of the liquid conductor; A plurality of electrical paths formed to cross the guide part, the electrical paths being disconnected from each other in the guide part, and at least one of the electrical paths formed to be electrically connected by the liquid conductor part; And And a detector connected to the electrical wiring part and detecting a movement of the liquid conductor using a change in the electrically connected electrical path. 10. The method of claim 9, The electrical paths are spaced apart from each other at predetermined intervals, Accelerometer, characterized in that the minimum change of the detectable acceleration is set by the predetermined interval. Masking at least a portion of the photosensitive glass such that an unmasked portion forms a pattern; Irradiating light onto the photosensitive glass so that the pattern is exposed to light; Etching the photosensitive glass such that the pattern is recessed into the photosensitive glass; Injecting a liquid conductor into the recessed portion to move the liquid conductor along the recessed portion; And And covering the recessed portion by using a cover having a plurality of electrical paths disconnected from each other. The method of claim 11, And heat-treating the photosensitive glass to change the physical properties of the pattern exposed to the light.

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