JP2010078465A - Acceleration sensor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an acceleration sensor device that is easy to manufacture with a simple structure and that has high reliability and high accuracy of acceleration detection.
SOLUTION: A plurality of electrodes 2a and 2b arranged in a row are respectively arranged in a space 1 with a space 1 therebetween and vertically opposed to each other, and arranged from both ends of the space 1 toward the center. The acceleration sensor device 9 includes the elastic member 4 and the conductor block 3 accommodated between the elastic members 4 in the space 1. In order to change the capacitance generated in the capacitive electrode 2 (between the electrodes 2a and 2b) at a position where the inertial force according to the acceleration and the stress acting on the elastic member 4 are balanced, the elastic member is changed in advance. By measuring the stress accompanying the deformation of 4, the acceleration can be easily calculated and detected based on the position of the conductor block 3 and the mass of the conductor block 3.
[Selection] Figure 1

Description

  The present invention relates to an acceleration sensor device that includes a mechanism that changes capacitance between capacitive electrodes in accordance with the magnitude of acceleration, and that detects acceleration based on the change in capacitance.

  Conventionally, as an acceleration sensor device for detecting acceleration, a mechanism for changing the capacitance between capacitive electrodes according to the magnitude of acceleration is provided, and the acceleration is detected by the change in capacitance. (For example, refer to Patent Documents 1 and 2).

  Such an acceleration sensor device generally includes a mass portion (weight portion) supported by a beam and a fixed electrode disposed to face the mass portion. A movable electrode is formed on the mass portion so as to face the fixed electrode, and an electrostatic capacity is generated between the capacitive electrode composed of the fixed electrode and the movable electrode.

  When acceleration occurs in the acceleration sensor device, the beam bends according to the magnitude of the acceleration, the distance between the capacitance electrodes varies, and the capacitance changes. By detecting this change in capacitance, the acceleration generated in the acceleration sensor device, that is, the acceleration of a device such as an automobile equipped with the acceleration sensor device is detected.

Such an acceleration sensor device usually applies a fine processing technique such as etching to a semiconductor substrate such as a silicon substrate to provide mechanical movable parts such as a beam part and a mass part and electric wiring parts such as capacitive electrodes. It is manufactured by forming.
JP 2006-250910 A JP 2007-85747

  However, in the conventional acceleration sensor device, there is a possibility that mechanical destruction such as bending occurs in the beam portion. In particular, if the beam part is made thinner or longer in order to increase the accuracy of acceleration detection, the strength of the beam part is reduced or the stress generated when the beam is bent is increased. The possibility increases.

  In addition, since the semiconductor substrate is manufactured by applying a fine processing technique such as etching, a high level of technology is required for manufacturing, and it is difficult to ensure processing accuracy.

  The present invention has been completed in view of such conventional problems, and an object of the present invention is to provide an acceleration sensor device that is easy to manufacture with a simple structure and has high reliability and high accuracy of acceleration detection. There is to do.

  The acceleration sensor device according to the present invention includes a capacitive electrode in which a plurality of electrodes arranged in a row are arranged to face each other with a space therebetween, and from both ends of the space toward the center. And a conductor block accommodated between the elastic members in the space.

  The acceleration sensor device according to the present invention is characterized in that, in the above-described configuration, the space is formed in an insulating container, and the capacitive electrode is arranged with the space interposed therebetween.

  The acceleration sensor device of the present invention is characterized in that, in the above configuration, the upper and lower capacitive electrodes are arranged in parallel, and the conductor block has upper and lower surfaces parallel to the capacitive electrode.

  In addition, the acceleration sensor device of the present invention includes a capacitor electrode in which a plurality of electrodes arranged in a row have a space therebetween and face one electrode vertically, and from both ends of the space to a central portion. It is characterized by comprising an elastic member respectively disposed toward and a conductor block accommodated between the elastic members in the space.

  Moreover, the acceleration sensor device of the present invention is characterized in that, in each of the above-described configurations, the plurality of electrodes have an interval between adjacent ones smaller than an outer dimension when the conductor block is viewed in plan. is there.

  According to the acceleration sensor device (first configuration) of the present invention, a plurality of electrodes each arranged in a row are arranged in a space between each other and vertically opposed to each other, and from both ends of the space to the center Since it is provided with elastic members respectively arranged toward the parts and conductor blocks accommodated between the elastic members in the space, it is easy to manufacture with a simple structure, and reliability and accuracy of acceleration detection are A high acceleration sensor device can be provided.

  That is, when acceleration occurs in the space, an inertial force corresponding to the magnitude of the acceleration acts on the conductor block, and a stress (elastic force) is applied from the elastic member to the conductor block trying to move in the space by this inertial force. Works. The conductor block is stationary with respect to the space at a position where the inertial force and stress are balanced (position where the inertial force and stress are the same magnitude and in the opposite direction), and at this position, the capacitive electrode (upper and lower electrodes) The capacitance generated during (between) is changed. Therefore, it is possible to easily detect at which position in the space, that is, at which position the elastic member is deformed (compressed), the inertial force and the stress are balanced. Therefore, by measuring in advance the force required to deform the elastic member (stress applied from the elastic member), it is possible to detect the inertial force acting on the conductor block at its stationary position (capacitance electrode position). The magnitude of acceleration can be calculated from the inertial force and the mass of the conductor block.

  In such an acceleration sensor device, the conductor block is only accommodated in the space where the capacitive electrodes are arranged above and below, so that the structure is simple and the microfabrication that forms a fine movable part such as a beam part. Is not particularly necessary and easy to manufacture. In addition, since there are no fine movable parts, mechanical destruction that hinders the function of the acceleration sensor device hardly occurs, and the reliability is high. In addition, since the inertial force due to acceleration can be detected with high accuracy as the stress from the elastic body using the change in capacitance generated between the capacitive electrodes (between the upper and lower electrodes), the acceleration detection High accuracy. Therefore, according to the acceleration sensor device of the present invention, it is possible to provide an acceleration sensor device that is easy to manufacture with a simple structure and that has high reliability and high accuracy of acceleration detection.

  Further, the acceleration sensor device of the present invention, in the above configuration, when the space is formed in the insulating container and the capacitive electrode is disposed across the space, the conductor block is sealed in the space in the insulating container, The following effects can be obtained by forming the capacitive electrode inside the insulating container positioned above and below the space.

  In other words, the conductor block can be reliably stored in the space, and a part of the insulating container is interposed between the conductor block and the capacitor electrode, so that wear due to direct contact of the capacitor electrode with the conductor block is achieved. And chipping can be effectively prevented. In addition, it is possible to form a plurality of electrodes while ensuring good electrical insulation between adjacent objects in the insulating container. Therefore, in this case, reliability and productivity as an acceleration sensor device can be improved.

  In the acceleration sensor device of the present invention, in the above configuration, when the upper and lower capacitive electrodes are arranged in parallel and the conductor block has upper and lower surfaces parallel to the capacitive electrode, the conductor block is, for example, spherical. Compared to the case, when the conductor block is interposed between the upper and lower capacitive electrodes, the capacitance between the capacitive electrodes can be changed more effectively. Therefore, an acceleration sensor device that can more reliably detect acceleration due to a change in capacitance can be provided.

  In addition, according to the acceleration sensor device (second configuration) of the present invention, the capacitive electrode in which a plurality of electrodes arranged in a row are arranged to face each other vertically with a space therebetween, Since the elastic member disposed respectively from the both ends of the space toward the central portion and the conductor block accommodated between the elastic members of the space, as in the case of the first configuration described above, It is possible to provide an acceleration sensor device that is easy to manufacture with a simple structure and that has high reliability and high acceleration detection accuracy.

  Moreover, according to this acceleration sensor apparatus, it is easy to improve the productivity as an apparatus. That is, one of the capacitive electrodes is a plurality of electrodes, and the other is one electrode that is vertically opposed to the plurality of electrodes, so that there is a slight misalignment between the plurality of electrodes and one electrode. Even if this occurs, within the range where each of the plurality of electrodes is opposed to one electrode, the area where each capacitive electrode faces is set to a predetermined area (the area of each of the plurality of electrodes). Can do. For this reason, it is not necessary to precisely perform alignment for each capacitor electrode, which is effective in improving productivity as an acceleration sensor device.

  Therefore, according to the acceleration sensor device of the present invention, it is possible to provide an acceleration sensor device that is easy to manufacture with a simple structure, has high reliability and high accuracy of acceleration detection, and can easily improve productivity. it can.

  In addition, the acceleration sensor device according to the present invention is configured such that, in each of the above-described configurations, the plurality of electrodes have an acceleration magnitude when the distance between adjacent electrodes is smaller than the outer dimension when the conductor block is viewed in plan. It is effectively prevented that the conductor block that has moved in response accidentally enters between adjacent capacitor electrodes (a plurality of electrodes), and no capacitance change occurs in any of the capacitor electrodes. Therefore, even though acceleration occurs, the capacitance does not change in any of the capacitive electrodes, and it is effectively prevented that false detection is made unless acceleration occurs. A high acceleration sensor device can be obtained.

(First configuration)
The acceleration sensor device of the present invention will be described with reference to the accompanying drawings.

  Fig.1 (a) is a top view (perspective view) which shows an example of embodiment of the acceleration sensor apparatus (1st structure) of this invention, FIG.1 (b) is sectional drawing in the AA line | wire It is. In FIG. 1, 1 is a space provided inside the insulating container 5, 2 is a capacitive electrode composed of electrodes 2 a and 2 b facing each other with the space 1 interposed therebetween, and 3 is a conductor accommodated in the space 1. Blocks 4 are elastic members, 5 is an insulating container, and 9 is an acceleration sensor device.

  The acceleration sensor device 9 is mounted on a device such as an automobile, a game machine, or a camera shake prevention device. The acceleration sensor device 9 detects the acceleration of the device and sends an electrical signal to a display device such as a display as necessary to display the acceleration numerical value. Or a function of stopping the device on which the acceleration sensor device 9 is mounted.

  The acceleration sensor device 9 detects the position of the conductor block 3 that moves in accordance with the acceleration of the space 1 based on a change in the capacitance of the capacitive electrode 2 (between the electrodes 2a and 2b), and obtains the position by detecting the position. The acceleration is calculated based on the stress acting on the block 3 from the elastic member 4.

  That is, according to the acceleration sensor device 9, when an acceleration is applied to the space 1, the inertial force according to the acceleration and the stress from the elastic member 4 repelling the conductor block 3 that is moving by the inertial force Acts on the conductor block 3. The conductor block 3 is stationary with respect to the space 1 at a position where the inertial force and the stress are balanced, and the capacitance generated in the capacitive electrode 2 (between the electrodes 2a and 2b) is changed at this position.

  Therefore, by measuring the mass of the conductor block 3 and the force required to deform the elastic member 4 (stress applied from the elastic member 4) in advance, the stationary position (the position of the corresponding capacitive electrode 2) is detected. Thus, the inertial force acting on the conductor block 3 can be detected, and the acceleration acting on the conductor block 3 can be calculated from the inertial force and the mass of the conductor block 3.

For example, the acceleration a, the mass of the conductor block 3 m, when the inertial force corresponding to the acceleration and F _1, a F _{1 =} m × a as is well known, the stress from the elastic member 4 in the rest position described above Is F ₂ , F ₁ = F ₂ = mxa, that is, a = F ₂ / m. Therefore, by measuring the mass m of the conductor block 3 and the force F ₂ required to deform the elastic member 4 in advance, the acceleration a acting on the conductor block 3 can be calculated.

Actually, since resistance such as friction is applied to the conductor block 3, it is preferable to correct that amount. For example, if the frictional force between the bottom surface of the bottom surface and space the first conductor block 3 and F _3, the original inertial force F ₁ generated according to the acceleration a, the frictional force F ₃ in the inertial force F ₁₁ of apparent The added size (F ₁ = F ₁₁ + F ₃ ). Since the inertial force _{F 11} of the apparent stress _{F 2} is balanced _F 11 = _{F 2,} is that is _{F 1 = F 2 + F 3} , from the right acceleration _{a, a = F 1 / m,} a = F ₂ / m + F ₃ / m.

  Such an acceleration sensor device 9 has a simple structure because only the conductor block 3 is accommodated in the space 1 in which the capacitive electrodes 2 are arranged above and below, and for example, a fine movable part such as a beam part. There is no particular need for microfabrication to form, and fabrication is easy. Further, since there are no fine movable parts, mechanical destruction that hinders the function of the acceleration sensor device 9 is unlikely to occur, and the reliability is high. Moreover, since the inertial force resulting from the acceleration can be detected with high accuracy as the stress acting from the elastic member 4 by utilizing the change in the capacitance generated in the capacitive electrode 2 (between the electrodes 2a and 2b), High accuracy of acceleration detection. Therefore, according to the acceleration sensor device 9 of the present invention, it is possible to provide the acceleration sensor device 9 that is easy to manufacture with a simple structure and that has high reliability and high accuracy of acceleration detection.

  The space 1 is for accommodating the conductor block 3 and the elastic member 4, and the accommodated conductor block 3 is divided into an inertial force caused by the acceleration generated in the space 1 and an elastic force acting from the elastic member 4. Accordingly, it has a shape and a dimension that can move inside.

  In the example of this embodiment, the space 1 has a rectangular parallelepiped shape, and a cross section (vertical cross section) in a direction orthogonal to the length direction is rectangular. The space 1 may have a square shape in the longitudinal section, a quadrangular shape in which corners are formed in an arc shape, a circular shape, an elliptical shape, or the like.

  Capacitance electrode 2 composed of a plurality of electrodes 2a and 2b facing each other generates capacitance with space 1 interposed therebetween, and as described above, conductor block 3 is interposed in space 1 between them. This is to detect the position of the conductor block 3 in the space 1 by changing the capacitance, and to detect the acceleration acting on the space 1 based on the position.

  The electrodes 2a and 2b constituting the capacitive electrode 2 detect the movement of the conductor block 3 in accordance with the magnitude of acceleration as a change in capacitance, and thereby detect the magnitude of acceleration. A plurality are arranged in one row from the center toward the center.

  That is, since a plurality of electrodes 2a and 2b are arranged with respect to the capacitive electrode 2, the conductor block 3 in the space 1 can be detected by detecting which electrode 2a and 2b the capacitance is changed. Can be detected easily and reliably. Note that the change in capacitance generated in the capacitive electrode 2 can be detected as a change in potential by measuring the potential between the electrodes 2a and 2b constituting the capacitive electrode 2, for example.

  When the plurality of electrodes 2a and 2b can detect acceleration in both end directions in the same manner, the electrodes 2a and 2b are arranged at the same size, shape, and adjacent interval on both ends across the central portion. (So-called symmetrical) is preferable.

  The plurality of electrodes 2a and 2b are arranged so that the elastic members 4 described later are arranged at the same adjacent interval in a region (elastic region) in which the elastic member 4 described later is deformed at a constant rate according to a proportional constant such as a spring constant or Young's modulus. In other words, the acceleration can be detected at a constant change rate. In this case, for example, it is effective for an application where it is desired to detect the acceleration at a constant change rate, such as an application for managing the acceleration (deceleration) of an endless belt for conveyance that repeats stopping and starting. For example, when an object that has moved at a constant speed, such as this endless belt, decelerates, an inertial force is generated in the opposite direction to that during acceleration, and the deceleration rate (negative acceleration) is detected by this inertial force. be able to.

The number of capacitor electrodes 2 arranged from both ends of the space 1 to the center may be appropriately set according to the required acceleration measurement accuracy, measurement range, and the like. For example, in the example of this embodiment, two capacitive electrodes 2 (two pairs) are arranged from each of both end portions of the space 1 toward the central portion, and one capacitive electrode 2 is disposed in the central portion of the space 1. Yes. The capacitive electrode 2 is configured by arranging electrodes 2a and 2b having the same shape and size with the space 1 therebetween and arranged at almost equal intervals. In this case, it is effective in linearly detecting the magnitude of acceleration generated in the space 1 and its change from 0 km / s ² to the maximum measurable value.

  In this case, when the conductor block 3 is interposed in each part of both of the adjacent capacitor electrodes 2 (electrodes 2a and 2b), the conductor is determined based on the rate of change in the capacitance of each capacitor electrode 2. The position of block 3 can also be calculated and detected. How much of the conductor block 3 is interposed between the electrodes 2a and 2b is based on the change in capacitance that occurs when the entire conductor block 3 is interposed between the electrodes 2a and 2b in the capacitive electrode 2. Thus, it can be easily calculated by detecting the proportion of the standard. For example, when the conductor block 3 has a quadrangular prism shape, a change in capacitance of the capacitive electrode 2 (between the electrodes 2a and 2b) occurs when the entire conductor block 3 is interposed between the electrodes 2a and 2b. If the change is about ½, it can be detected that about half of the conductor block 3 in plan view is interposed between the electrodes 2a and 2b.

  Further, the capacitor electrodes 2 are not necessarily arranged at regular intervals, and may be arranged in other ways. For example, a structure in which a capacitance electrode 2 is arranged at each position between the center portion and both end portions, and when an acceleration corresponding to this position occurs, a capacitance is changed and a signal is transmitted. Good. In this case, for example, it is effective for a purpose of causing a device on which the acceleration sensor device 9 is mounted to perform an operation such as displaying a warning indicating that a predetermined acceleration has occurred or stopping the device.

  The conductor block 3 moves in the space 1 in accordance with the acceleration generated in the space 1 and the elastic force applied from the elastic member 4, and electrostatics between the upper and lower electrodes 2a and 2b located in the moved portion. This is to increase the capacity.

  By measuring the capacitance between the upper and lower electrodes 2a and 2b in the space 1 in which the conductor block 3 is accommodated, and detecting the change in the capacitance, the position of the conductor block 3, that is, the inertial force And a position where the elastic force is balanced can be detected. Then, by measuring the force required to deform the elastic member 4 to its position and the mass of the conductor block 3 in advance, the inertial force can be detected and the acceleration can be calculated.

  In addition, when no acceleration occurs or when the generated acceleration disappears, the conductor block 3 is positioned at the center of the space 1 and returns, so it is easy to say that no acceleration is generated in the space 1. Can be detected. In order to detect that the conductor block 3 is located at the center of the space 1, for example, the capacitor electrode 2 may be disposed at the center of the space 1.

  The conductor block 3 is formed in a shape and size that can move while deforming (compressing) the elastic member 4 in the direction in which the inertial force acts (direction opposite to the direction where acceleration is applied). Is housed in. The movement of the conductor block 3 in the space 1 is caused by sliding or rolling on the lower surface of the space 1 due to the inertial force acting due to the acceleration of the space 1.

  In order to facilitate such movement, the conductor block 3 is formed in a polygonal column shape such as a triangular column shape or a quadrangular column shape (cuboid shape), a cylindrical shape, an elliptical column shape, a spherical shape, or the like. The conductor block 3 may have these shapes and the upper and lower surfaces, the side surfaces, and the like are curved, or the conductor block 3 may be partially formed with uneven portions.

  In addition, the conductor block 3 is formed of a material and a dimension that are interposed between the upper and lower electrodes 2a and 2b and can change the capacitance generated between them to an extent that can be easily detected. .

As a conductor material forming such a conductor block 3, a metal material such as iron, copper, nickel, cobalt molybdenum, chromium, tin, zinc or an alloy material thereof (for example, an iron-based alloy such as iron-nickel or copper) -Copper alloys such as zinc). Since these metal materials have a relatively high density (both have a density of 7 g / cm ³ or more (20 ° C.)), the inertial force generated in the conductor block 3 is increased so that acceleration can be easily detected. Is advantageous.

  When such a conductor material is interposed between the upper and lower electrodes 2a and 2b, the capacitance generated in the capacitive electrode 2 composed of the electrodes 2a and 2b increases. That is, the capacitance C generated in the capacitive electrode 2 (between the electrodes 2a and 2b) is, as is well known, C = ε × S / d (where ε is interposed between the upper and lower electrodes 2a and 2b facing each other). The dielectric constant of the dielectric (air, etc.), S is the area where the upper and lower electrodes 2a, 2b face each other, d is the distance between the upper and lower electrodes 2a, 2b in the opposite part), and this capacitance is When the conductor block 3 having a thickness t is interposed over the entire area between the upper and lower electrodes 2a and 2b facing each other, the thickness changes to ε × S / (dt). Therefore, the capacitance C generated in the capacitive electrode 2 is (ε × S / (dt)) / (maximum compared to the case where the conductor block 3 is not interposed between the upper and lower electrodes 2a and 2b. ε × S / d) = d / (dt) times larger.

  The thickness of the conductor block 3 is preferably as thick as possible in the space 1 in order to greatly change the capacitance between the vertically opposed electrodes 2a and 2b.

  In the example of this embodiment, the conductor block 3 is formed in a rectangular column shape having a thickness slightly lower than the height of the space 1. In addition, the conductor block 3 is formed with the same outer dimensions as the plurality of formed electrodes 2a and 2b when viewed in plan.

  For example, if the conductor block 3 is a quadrangular prism, the raw material such as an iron-nickel alloy is subjected to metal processing such as cutting processing, polishing processing, etching processing, and the like to be processed into a predetermined shape and size. Can be produced.

  The elastic member 4 has a function of applying stress (elastic force) to the conductor block 3. When acceleration occurs in the space 1, stress (elastic force) is applied in the opposite direction from the elastic member 4 to the conductor block 3 that attempts to move in the space 1 due to the inertial force caused by the acceleration. The stress increases as the deformation (compression) of the elastic member 4 increases, and the conductor block 3 is stationary with respect to the space 1 at a position where the inertial force and the elastic force are balanced. When no acceleration is generated in the space 1 (when no inertial force is applied to the conductor block 3), the conductor block 3 is moved to the center of the space 1 by the elastic force of the elastic member 4 (so-called origin return). )

  As such an elastic member 4, a spring made of a coil spring or an air spring, a resin material having a low elastic modulus (Young's modulus), or a member made of a rubber material such as rubber or sponge rubber can be used.

  If a spring is used as the elastic member 4, the range of elastic deformation (expansion / contraction) in proportion to the spring constant due to the inertial force is longer than the distance from the end (both ends) of the space 1 to the center. It is preferable to use one.

For example, when the length from the end to the center of the space 1 is set to 0.05 m (5 cm), the mass of the conductor block 3 is 0.05 kg (50 g), and the assumed maximum acceleration is about 10 m / s. ^{In the case of 2} (about the acceleration of gravity), the maximum value of inertial force is about 0.5N. As is well known, since F (force, unit: N) = k (spring constant, unit: N / m) × x (length to expand and contract, unit: m), the length x of the spring contracts is 1 / k. In order to keep the length x below the length of the space 1, a spring such as a coil spring having a spring constant k of about 10 N / m or slightly larger (less likely to shrink) than 0.5 / k <0.05. It means that it is suitable.

  Moreover, as a resin material with a low Young's modulus, for example, a material having a Young's modulus of about 1 to 20 MPa, such as a polyurethane resin or a silicone resin, can be used. As the rubber, natural rubber, urethane rubber, butyl rubber, neoprene rubber, styrene butadiene rubber, or other rubber materials (Young's modulus is about 0.01 to 20 MPa) can be used. As the sponge rubber, a material made porous (so-called sponge-like) by adding a foaming agent such as sodium carbonate, sodium bicarbonate, ammonium carbonate to the above-described rubber material (particularly rubber material other than natural rubber) is used. be able to.

  When the elastic member 4 is made of a resin material, rubber, or sponge rubber, the elastic member 4 may be disposed so as to fill the space 1 from both ends to the vicinity of the center, and is formed into a columnar shape or a cylindrical shape. It may be arranged in the space 1 in a different form.

  The elastic member 4 made of a resin material, rubber, or sponge rubber has the conductor block 3 in any one of the spaces 1 when an inertial force corresponding to the upper limit of the acceleration range to be detected by the acceleration sensor device 9 is applied. It is preferable to have a Young's modulus and dimensions (the area on which the length and stress act) such that they do not move to the end.

For example, if the mass of the conductor block 3 is 0.05 kg (50 g) and the maximum value of acceleration assumed is about 10 m / s ² , the maximum value of inertial force is about 0.5 N and stress acts. If the area is set to 5 mm × 5 mm (25 × 10 ⁻⁶ m ² ), the stress per unit area σ = 0.5 (N) / 25 × 10 ⁻⁶ (m ² ) = 0.02 × 10 ⁶ N / m ² = 0.02 MPa.

  As is well known, since ε (strain) = σ (stress per unit area, unit: MPa) / E (Young's modulus, unit: MPa), for example, ε is set to 0.5 (the length of the elastic member 4 is about half). The Young's modulus E of the elastic member 4 becomes E = 0.02 / 0.5 = 0.04 from 0.5 = 0.02 / E. That is, in this case, a material having a Young's modulus of about 0.04 MPa is suitable for the elastic member 4. Further, when a larger acceleration is applied or when the length of the space 1 is shortened, a material having a higher Young's modulus (not easily deformed) is suitable for the elastic member 4, and a case where a smaller acceleration is applied or a space If the length of 1 is increased, a material having a smaller Young's modulus (easily deformed) is suitable.

  In such an acceleration sensor device 9, for example, as in the example of this embodiment, the space 1 is formed in the insulating container 5, and the capacitive electrodes 2 (electrodes 2 a and 2 b) are arranged with the space 1 interposed therebetween. Has the following effects.

  That is, the conductor block 3 is enclosed in the space 1 in the insulating container 5, and each of the plurality of electrodes 2 a and 2 b constituting the capacitive electrode 2 is formed inside the insulating container 5 positioned above and below the space 1. Thus, the conductor block 3 can be reliably accommodated in the space 1.

  Further, by interposing a part of the insulating container 5 between the conductor block 3 and the capacitor electrode 2, it is possible to effectively prevent wear or chipping or the like due to direct contact of the capacitor electrode 2 with the conductor block 3. it can. Further, it is possible to prevent the adjacent electrodes 2a (or 2b) from being electrically short-circuited via the conductor block 3. In addition, a plurality of electrodes 2 a and 2 b can be formed in the insulating container 5 while ensuring good electrical insulation between adjacent ones. Therefore, in this case, the reliability and productivity of the acceleration sensor device 9 can be improved.

  In the example of this embodiment, the insulating container 5 has a rectangular parallelepiped shape, and a space 1 having a similar shape and a small size is formed therein, but at least a space for accommodating the conductor block 3 therein. As long as the external dimensions are such that 1 can be provided, a cylindrical shape or an elliptical column shape extending in the lateral direction may be used. For example, in consideration of workability when the acceleration sensor device 9 is mounted on a device or transported, suppression of breakage, and the like, an unevenness is provided on a part of the outer surface of the insulating container 5 or corners (ridges) are provided. The portion may be chamfered.

  The insulating container 5 includes an aluminum oxide sintered body (aluminum oxide ceramics), an aluminum nitride sintered body, a mullite sintered body, a silicon carbide sintered body, a silicon nitride sintered body, and a glass ceramic sintered body. Etc., a resin material such as an epoxy resin, a polyimide resin, and an acrylic resin, or an electrically insulating material such as a composite material of an inorganic material such as a ceramic material and a resin material.

  In the example of this embodiment, the insulating container 5 is formed by bonding a flat lid 5b to the upper surface of an insulating base 5a having a recess (no symbol) on the upper surface. A space 1 in which the conductor block 3 is accommodated is constituted by the concave portion of the insulating base 5a and the lid 5b. The lid 5b may have a recess (not shown) that faces the recess of the insulating base 5a.

  In addition, the surface of the insulating container 5 (insulating base 5a) which is the lower surface of the space 1 is subjected to a polishing process (for example, a so-called mirror polishing process) in order to facilitate the sliding of the conductor block 3. Smoothness may be increased. If the smoothness of the lower surface of the space 1 is increased, the correction of the frictional force as described above can be suppressed to a small level. In this case, if the insulating base 5a has a flat plate shape and the lid 5b has a recess (not shown) on the lower surface side, the upper surface of the insulating base 5a corresponding to the lower surface of the space 1 is polished. Can be done more easily. Therefore, the movement of the conductor block 3 by sliding is easy, and it is effective in increasing the productivity of the acceleration sensor device 9 with high acceleration detection accuracy.

  For example, if the insulating base 5a and the lid 5b are made of an aluminum oxide-based sintered body, the insulating container 5 is a raw material powder mainly composed of aluminum oxide powder and added with silicon oxide, calcium oxide or the like. Are processed into a sheet shape together with an organic solvent and a binder to produce a plurality of ceramic green sheets, laminated, and fired to produce the insulating base 5a and the lid 5b, and then the insulating base 5a and the lid 5b. Can be manufactured by joining them with a brazing material or a resin adhesive.

  In addition, if the insulating container 5 is made of a resin material such as an epoxy resin or a polyimide resin, an uncured material of these resin materials is shaped into a predetermined insulating base 5a or lid 5b using a mold. The insulating base 5a and the lid 5b are manufactured by molding and curing, and these can be manufactured by bonding them with a resin adhesive.

  The plurality of electrodes 2a and 2b constituting the capacitive electrode 2 are formed, for example, inside the insulating container 5 so as to sandwich the space 1 vertically. These electrodes 2a and 2b are formed of a metal material such as tungsten, molybdenum, manganese, copper, silver, palladium, gold, or platinum. Such a metal material is applied to the insulating base 5a and the lid 5b of the insulating container 5 in the form of a metallized layer, a plating layer, a metal foil, a vapor deposition layer, or the like.

  Each of the plurality of electrodes 2a and 2b is formed by, for example, printing a metal paste of tungsten on a ceramic green sheet serving as the insulating base 5a and the lid 5b, and placing the printed metal paste inside. It can be formed by laminating sheets.

  The insulating container 5 is wired as a conductive path for electrically connecting each of the plurality of electrodes 2a, 2b to an external electric circuit from the capacitive electrode 2 (the plurality of electrodes 2a, 2b) to the upper surface and the lower surface. It is preferable to form a conductor (not shown). By connecting the exposed portion of the wiring conductor to an external electric circuit and measuring the capacitance between the upper and lower electrodes 2a and 2b, the change in the capacitance is detected and the position of the conductor block 3 is detected. As described above, the acceleration generated in the space 1 based on the position of the conductor block 3, that is, the acceleration of the acceleration sensor device 9 can be detected.

  In this case, the external electric circuit is formed on a circuit board mounted on a device such as an automobile, a game machine, or a transport device such as an endless belt. When the acceleration sensor device 9 is mounted as a component, the acceleration generated in the device is detected, and in the case of an automobile, the speed is adjusted by a curve. In the case of a game machine, the acceleration is displayed on the screen depending on the magnitude of the acceleration. The size can be displayed.

  In addition, an electronic component (semiconductor integrated circuit element, capacitor element, inductor element, etc.) (not shown) that performs processing such as calculation of acceleration as described above and analysis and amplification of an electrical signal according to the calculated acceleration is provided. Alternatively, it may be mounted on the surface or inside of the insulating container 5. Further, an electric circuit (not shown) corresponding to a capacitor element or an inductor element may be formed inside or on the surface of the insulating container 5. These electric circuits can be formed by the same method using the same material as that for forming the electrodes 2a and 2b, for example.

  In the acceleration sensor device 9, the capacitive electrode 2 (a plurality of electrodes 2 a and 2 b constituting the capacitive electrode 2) is arranged in parallel in the vertical direction, and the conductor block 3 has upper and lower surfaces parallel to the capacitive electrode 2. Compared to the case where the conductor block 3 is spherical, for example, when the conductor block 3 is interposed between the electrodes 2a and 2b constituting the capacitor electrode 2, the capacitor electrode 2 (between the electrodes 2a and 2b). ) Can be changed more effectively. Therefore, the acceleration sensor device 9 can more reliably detect the change in capacitance and calculate the acceleration based on the change in capacitance.

(Second configuration)
2A and 2B are a plan view (perspective view) and a cross-sectional view showing an example of an embodiment of the acceleration sensor device (second configuration) of the present invention, respectively. In FIG. 2, the same parts as those in FIG.

  In the acceleration sensor device 9 ′, the capacitive electrode 2 includes a plurality of electrodes 2b arranged in a row, and one electrode 2c that is vertically opposed to each other with the space between the plurality of electrodes 2b. It is comprised by. Regarding portions other than the capacitive electrode 2, the acceleration sensor device 9 'having the second configuration is the same as the acceleration sensor device 9 having the first configuration described above, and the description of the same portion will be omitted below.

  According to such an acceleration sensor device 9 ′, the same effect as that of the acceleration sensor device 9 described above can be obtained. That is, according to the acceleration sensor device 9 ′, when an acceleration is applied to the space 1, an inertial force corresponding to the acceleration and a stress from the elastic member 4 repelling the conductor block 3 that attempts to move with the inertial force. Acts on the conductor block 3. The conductor block 3 is stationary with respect to the space 1 at a position where the inertial force and the stress are balanced, and the capacitance generated in the capacitive electrode 2 (between each of the electrodes 2b and the electrode 2c) at this position. To change.

  Therefore, by measuring in advance the mass of the conductor block 3 and the force required to deform the elastic member 4 (stress applied from the elastic member 4), it acts on the conductor block 3 at its stationary position (position of the electrode 2b). The inertial force to be detected can be detected, and the acceleration acting on the conductor block 3 can be calculated from the inertial force and the mass of the conductor block 3.

  In such an acceleration sensor device 9 ′, the conductor block 3 is accommodated in a space 1 in which capacitive electrodes 2 (a plurality of electrodes 2b and a single electrode 2c facing the plurality of electrodes 2b) are arranged above and below. Therefore, the structure is simple, and for example, microfabrication for forming a fine movable part such as a beam part is not particularly necessary and is easy to manufacture. Further, since it does not have a fine movable part, it is difficult to cause mechanical destruction that hinders the function as the acceleration sensor device 9 ', and the reliability is high. Moreover, since the inertial force resulting from the acceleration can be detected with high accuracy as the stress acting from the elastic member 4 by utilizing the change in capacitance generated in the capacitive electrode 2 (between the electrodes 2b and 2c), High accuracy of acceleration detection. Therefore, according to the acceleration sensor device 9 ′ of the present invention, it is possible to provide the acceleration sensor device 9 ′ that can be easily manufactured with a simple structure and that has high reliability and high accuracy of acceleration detection.

  This acceleration sensor device 9 ′ can be manufactured by the same method using the same material as the acceleration sensor device 9 of the first configuration, and can be used for the same purpose. In addition, one electrode 2c that is vertically opposed to the plurality of electrodes 2b can also be formed by the same method using the same metal material as that of the electrode 2b. For example, if the electrode 2c is made of a metallized layer of tungsten, the metal paste of tungsten is printed on a ceramic green sheet serving as the insulating container 5 (in the example of this embodiment, the lid 5b) and fired. Can be formed.

  Further, in this acceleration sensor device 9 ′, one of the capacitive electrodes 2 is a plurality of electrodes 2b, and the other is one electrode 2c facing the plurality of electrodes 2b. This is effective in improving the productivity of the acceleration sensor device 9 '.

  That is, one of the capacitive electrodes 2 is a plurality of electrodes 2b, and the other is one electrode 2c that is vertically opposed to the plurality of electrodes 2b, so that the space between the plurality of electrodes 2b and one electrode 2c is Even if a slight positional deviation occurs, if each of the plurality of electrodes 2b is in a range facing each electrode 2c, the area where each electrode 2b faces each other is set to a predetermined area ( The area of each of the plurality of electrodes 2b). For this reason, it is not necessary to precisely align each individual capacitive electrode 2 (2b), which is effective in improving the productivity of the acceleration sensor device 9 '.

  Therefore, according to this acceleration sensor device 9 ′, there is provided an acceleration sensor device 9 ′ that can be easily manufactured with a simple structure, has high reliability and high accuracy of acceleration detection, and can easily improve productivity. be able to.

  Further, in the acceleration sensor devices 9 and 9 ′ having the above-described configurations, the plurality of electrodes 2a and 2b, when the interval between adjacent ones is smaller than the outer dimension when the conductor block 3 is viewed in plan view, The conductor block 3 that has moved to a position where the inertial force and the elastic force are balanced accidentally enters between the adjacent capacitive electrodes 2 (electrodes 2a and 2b or electrodes 2b and 2c). It is effectively prevented that no change occurs. Therefore, it is effectively prevented that the capacitance does not change in any capacitive electrode 2 in spite of the acceleration in the space 1 and is erroneously detected that no acceleration occurs. It can be set as the acceleration sensor apparatus 9 and 9 'with higher detection accuracy.

  Such an acceleration sensor device 9, 9 'is, for example, an elastic member formed according to the distance from the central portion to the end portion of the concave portion in the concave portion of the insulating base 5a produced as described above. 4 and the conductor block 3 are inserted, and then the lid 5b is joined to the upper surface of the insulating base 5a so as to close the recess.

  The elastic member 4 is, for example, the insulating container 5 (insulating base 5a) via a bowl-shaped metal fitting (not shown) or the like attached to both end portions of the insulating container 5 (for example, in the recess of the insulating base 5a) in advance. Can be attached so that the outer end portion does not move. Further, the outer end portion of the elastic member 4 may be bonded to the insulating container 5 using an adhesive instead of the metal fitting. Moreover, you may use these metal fittings and resin adhesives together.

  Further, the lid 5b and the insulating base 5a can be bonded by, for example, bonding via a bonding material such as an organic resin adhesive, glass, brazing material, or the like. In this case, a metal layer (not shown) may be formed in advance on the joint surface between the two, and the metal layers may be joined with a brazing material. The metal layer can be formed by the same method using the same metal material as the capacitor electrode 2 (electrodes 2a, 2b, 2c).

  Note that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention. For example, at least a part of the insulating container 5 may be formed of a light-transmitting material such as glass, acrylic resin, or methacrylic resin so that the position of the conductor block 3 can be seen from the outside. . In this case, it is possible to easily confirm whether or not the conductor block 3 is moving normally according to the acceleration of the space 1, and the acceleration sensor devices 9, 9 ′ are more accurate and easy to check. It can be.

  Further, two such acceleration sensor devices 9 and 9 ′ are mounted on an external device so as to be orthogonal to each other horizontally, and the acceleration components in two orthogonal directions (so-called XY directions) are synthesized to be horizontal. It is also possible to detect the magnitude of the acceleration in the direction.

(A) is a top view (perspective view) which shows an example of embodiment of the acceleration sensor apparatus (1st structure) of this invention, (b) is sectional drawing in the AA line. (A) is a top view (perspective view) which shows an example of embodiment of the acceleration sensor apparatus (2nd structure) of this invention, (b) is sectional drawing in the AA line.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Space 2 ... Capacitance electrode 2a ... Electrode 2b ... Electrode 2c ... One electrode 3 ... Conductor block 4 ... Elasticity Member 5 ... Insulating container 5a ... Insulating substrate 5b ... Lid 9, 9 '... Acceleration sensor device

Claims (5)

A plurality of electrodes each arranged in a row with a space in between and facing each other vertically, an elastic member respectively disposed from both ends of the space toward the center, and the space An acceleration sensor device comprising: a conductor block accommodated between the elastic members. The acceleration sensor device according to claim 1, wherein the space is formed in an insulating container, and the capacitive electrode is disposed across the space. The acceleration sensor device according to claim 1, wherein the upper and lower capacitive electrodes are arranged in parallel, and the conductor block has upper and lower surfaces parallel to the capacitive electrode. A plurality of electrodes arranged in a row with a space between them, a capacitive electrode formed vertically opposite to one electrode, an elastic member respectively disposed from both ends of the space toward the center, An acceleration sensor device comprising: a conductor block accommodated between the elastic members in the space. 5. The acceleration sensor device according to claim 1, wherein an interval between adjacent ones of the plurality of electrodes is smaller than an outer dimension when the conductor block is viewed in plan.

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