JP2009252463A - Miniature electric-mechanical switch - Google Patents

Abstract

An object of the present invention is to provide a micro electromechanical switch capable of improving the contact reliability between a movable contact portion and a fixed contact portion.
A microelectromechanical switch includes a fixed contact portion 2 formed on one surface 1a side of a base substrate 1 and a movable contact portion 3 disposed opposite to the fixed contact portion 2 on the one surface 1a side of the base substrate 1. The movable contact portion 3 is fixed so that the normal direction of the one surface 1a of the base substrate 1 is the central axis O direction, and the outer peripheral shape in a plane orthogonal to the central axis O direction is formed in a perfect circle shape. The contact portion 2 has three contact portions each having a contact surface 20a that is elastically contacted with the outer peripheral surface 3a of the movable contact portion 3 in a direction along a radial direction of a circle centering on the central axis O in the orthogonal plane. 20, each contact portion 20 is arranged in a shape that is rotationally symmetric three times within the orthogonal plane.
[Selection] Figure 1

Description

  The present invention relates to a microelectromechanical switch such as a MEMS switch or a NEMS switch.

  Conventionally, various micro electromechanical switches such as MEMS switches and NEMS switches have been proposed. An example of this type of microelectromechanical switch is an RF microrelay as shown in Patent Document 1. As shown in FIG. 12A, a device disclosed in Patent Document 1 includes a pair of contacts (fixed contact portions) 100, a short-circuit contact (movable contact portion) 200 that short-circuits between the pair of fixed contact portions 100, and a movable An actuator 300 that moves the contact portion 200 so as to contact with or separate from each fixed contact portion 100 is housed in the housing 400. A plurality of (in the illustrated example, four) trapezoidal trapezoidal trapezoidal (bottom-shaped truncated pyramid-shaped) tooth portions 110 are formed on the surface of each fixed contact portion 100 facing the movable contact portion 200. On the other hand, a plurality of trapezoid trapezoidal short-circuit tooth portions 210 (three in the illustrated example) are formed on the surface of the movable contact portion 200 facing each fixed contact portion 100.

In what is shown in Patent Document 1, by driving the actuator 300, the movable contact portion 200 moves to each fixed contact portion 100 side. When the movable contact portion 200 moves to the fixed contact portion 100 side, as shown in FIG. 12B, the short-circuit tooth portion 210 of the movable contact portion 200 and the tooth portion 110 of the fixed contact portion 100 are Each short-circuited tooth portion 210 of the movable contact portion 200 comes into contact with a gap between adjacent tooth portions 110 of the fixed contact portion 100 (that is, meshes), and the pair of fixed contact portions 100 are movable contacts. It is electrically connected by the unit 200.
Japanese translation of PCT publication No. 2004-513696

  However, in the above-described Patent Document 1, since one short-circuit tooth portion 210 is in contact with two tooth portions 110, the contact pressure between the short-circuit tooth portion 210 and each of the two tooth portions 110 is biased. The one tooth portion 110 and the short-circuit tooth portion 210 may be contacted with excessive contact pressure, and in this case, deterioration of on-resistance or sticking may occur. Therefore, in the thing shown in patent document 1, there existed a problem that the contact reliability of the movable contact part 200 and the fixed contact part 100 was bad. In order to improve contact reliability, it is conceivable that the short-circuit tooth portion 210 is surrounded by the four tooth portions 110 and the four side surfaces of the short-circuit tooth portion 210 are brought into contact with the four tooth portions 110, respectively. In this case, in order to stably contact the movable contact portion 200 and the fixed contact portion 100, it is preferable to arrange the four tooth portions 110 so that the opposing directions of the pair of tooth portions 110 are orthogonal to each other. . However, if the opposing directions of the pair of tooth portions 110 are orthogonal to each other, the force with which one tooth portion 110 presses the short-circuit tooth portion 210 can be applied only to the other tooth portions 110 facing the one tooth portion 110. I can't receive it. Then, when the short-circuit tooth portion 210 is surrounded by the four tooth portions 110, the contact area between the movable contact portion 200 and the fixed contact portion 100 can be increased, but the contact reliability is one short-circuit tooth. There was little difference from what the part 210 was in contact with the two teeth 110 and the problem of poor contact reliability still remained.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a micro electromechanical switch capable of improving the contact reliability between a movable contact portion and a fixed contact portion.

  In order to solve the above-described problem, in the invention of claim 1, a fixed contact portion formed on one surface side of the base substrate, and a movable contact portion at a portion facing the fixed contact portion on the one surface side of the base substrate. And a movable contact support portion fixed to the one surface side of the base substrate, and the flexible portion of the movable contact support portion is deformed so that the movable contact portion contacts the fixed contact portion. The movable contact portion has a normal direction of the one surface of the base substrate as a central axis direction, and the fixed contact portion is centered on the central axis in an orthogonal plane perpendicular to the central axis direction. A plurality of contact portions having contact surfaces that are elastically contacted with the outer peripheral surface of the movable contact portion in a direction along a radial direction of the circle, and the number of contact portions is an integer multiple of 3 , Each contact portion has the center in the orthogonal plane Characterized in that it is arranged to form a rotationally symmetric with only rotational position number of the contact portion and the rotation axis.

  According to the first aspect of the present invention, the direction of the force with which the contact portion presses the movable contact portion is a direction intersecting the central axis direction of the movable contact portion, and each contact portion is movable within the orthogonal plane. Since the central axis of the contact part is a rotational axis and the rotational position is the same as the number of contact parts, the contact parts are arranged in a rotationally symmetric shape. Since the contact pressure between each and the movable contact portion is equal, and the number of contact portions is an integer multiple of 3, the force with which one contact portion presses the movable contact portion is set to a plurality of contact points. Even if there is a bias in the force that can be received by other contact parts and the contact part presses the movable contact part, it is movable compared to the case where the number of contact parts is two or four. Since each contact part can be brought into contact with the contact part with uniform contact pressure, the movable contact part The contact state with the fixed contact portion is stabilized, and as a result, deterioration of on-resistance and occurrence of sticking can be suppressed, and the contact reliability between the movable contact portion and the fixed contact portion is improved. Can do.

  According to a second aspect of the present invention, in the first aspect of the invention, the outer peripheral surface of the movable contact portion is inclined so as to move away from the central axis as the distance from the one surface of the base substrate increases. .

  According to the invention of claim 2, since the outer peripheral surface of the movable contact portion easily slides on the contact surface, the power consumption of the actuator can be reduced, and the outer peripheral surface of the movable contact portion and the contact surface of the contact portion. Therefore, the contact resistance can be reduced, and deterioration of on-resistance and occurrence of sticking can be suppressed.

  According to a third aspect of the invention, in the first or second aspect of the invention, the contact surface of each of the contact portions is inclined so as to move away from the central axis as the distance from the one surface of the base substrate increases. Features.

  According to the invention of claim 3, since the outer peripheral surface of the movable contact portion becomes easy to slide on the contact surface, the power consumption of the actuator can be reduced, and the outer peripheral surface of the movable contact portion and the contact surface of the contact portion. Therefore, the contact resistance can be reduced, and deterioration of on-resistance and occurrence of sticking can be suppressed.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the fixed contact portion is a contact pressure that elastically contacts the contact surface of the contact portion with the outer peripheral surface of the movable contact portion. A plurality of spring portions are provided for each of the contact portions.

  According to the invention of claim 4, the contact surface of the contact portion is perpendicular to the central axis of the movable contact portion, compared to the case where one contact pressure spring portion is provided for the contact portion. In the orthogonal plane, it is easy to make elastic contact in the direction along the radial direction of the circle centered on the central axis, so that the contact reliability is improved.

  The invention according to claim 5 is the invention according to any one of claims 1 to 4, wherein the fixed contact portion includes a guide portion that sandwiches the contact portion in a direction perpendicular to the radial direction in the orthogonal plane. It is characterized by that.

  According to the invention of claim 5, the contact portion is difficult to be displaced in a direction other than the direction along the radial direction of the circle centering on the central axis in an orthogonal plane orthogonal to the central axis of the movable contact portion. Since the contact surface of the contact portion is easily elastically contacted with the outer peripheral surface of the movable contact portion in the direction along the radial direction, the contact reliability is improved.

  In the present invention, each contact portion of the fixed contact portion can be brought into contact with the movable contact portion with equal contact pressure, so that the contact state between the movable contact portion and the fixed contact portion is stabilized, and as a result, the on-resistance is deteriorated. In addition, the occurrence of sticking can be suppressed, and the contact reliability between the movable contact portion and the fixed contact portion can be improved.

(Embodiment 1)
The microelectromechanical switch of this embodiment is a MEMS switch used for transmission of a high-frequency signal, for example, and as shown in FIGS. 1 and 2, one surface of a base substrate 1 formed of an insulating material such as glass. A flexible contact portion 2 formed on the 1a side (the upper surface side in FIG. 1B) and a flexible contact portion 3 formed on a portion of the one surface 1a side of the base substrate 1 facing the fixed contact portion 2. The movable contact support portion 4 having the portion 40 and fixed to the one surface 1a side of the base substrate 1 and the flexible portion 40 of the movable contact support portion 4 are deformed so that the movable contact portion 3 contacts the fixed contact portion 2. An actuator 5 serving as a driving means is provided. In addition, illustration of the movable contact support part 4 is abbreviate | omitted in FIG.1 (b).

  One surface 1a of the base substrate 1 is formed on a flat surface, and a pair of signal lines 6 are formed on the one surface 1a side as shown in FIG. One signal line 6 (hereinafter referred to as reference numeral 6A as required) is connected to the fixed contact portion 2, and the other signal line 6 (hereinafter referred to as reference numeral 6B as required) is connected to the movable contact portion 3. Is electrically connected. Therefore, when the movable contact portion 3 contacts the fixed contact portion 2, the signal lines 6A and 6B are electrically connected. The signal line 6B is formed with a joint portion 6a to which the movable contact support portion 4 is joined. The base substrate 1 is not limited to glass but may be formed of ceramics or the like.

  The flexible portion 40 includes a base portion 40a made of, for example, a silicon substrate. The base 40a is formed in a rectangular strip shape with a small thickness so that flexibility can be obtained. The dimension of the flexible part 40 in the longitudinal direction (in the case of this embodiment, equal to the dimension in the longitudinal direction of the base part 40a) can be opposed to the joint part 6a at one end and to the fixed contact part 2 at the other end. Set to length.

  A conductor portion 40b made of a metal thin film (for example, an Au thin film) is formed on the entire surface of one surface (the lower surface in FIG. 2) in the thickness direction of the base portion 40a. A prismatic support portion 41 made of a metal material (for example, Au) is formed on one end side (left side in FIG. 2) in the longitudinal direction of the conductor portion 40b opposite to the base portion 40a side (the lower surface side in FIG. 2). The movable contact portion 3 is provided on the other end side in the longitudinal direction (the right side in FIG. 2).

  The support portion 41 supports the flexible portion 40 on the one surface 1 a side of the base substrate 1 so that a predetermined gap is formed between the flexible portion 40 and the base substrate 1. The movable contact support portion 4 described above is formed in an L-shaped cross section having a flexible portion 40 and a support portion 41, and the front end surface (lower end surface in FIG. 2) of the support portion 41 is joined to the signal line 6B. By bonding to the surface of the portion 6a (upper surface in FIG. 2), the base substrate 1 is fixed to the one surface 1a side. Thus, the flexible portion 40 is disposed on the one surface 1a side of the base substrate 1 such that the conductor portion 40b faces the base substrate 1 and the thickness direction is the same as the thickness direction of the base substrate 1. . In addition, the movable contact portion 3 and the signal line 6B are electrically connected through the conductor portion 40b and the support portion 41.

  The distance between the support portion 41 and the movable contact portion 3 is such that when the flexible portion 40 is deformed, the movable contact portion 3 can be regarded as moving along the central axis O direction. 2 is sufficiently longer than the distance to 2.

  The actuator 5 deforms the flexible portion 40 using electrostatic attraction (Coulomb force), and is formed between the fixed contact portion 2 and the signal line 6B on the one surface 1a side of the base substrate 1. The fixed electrode 50 is provided. In the micro electromechanical switch of the present embodiment, the conductor portion 40 b of the movable contact support portion 4 is used as a movable electrode corresponding to the fixed electrode 50. Therefore, by applying a predetermined driving voltage between the conductor portion 40b and the fixed electrode 50, the conductor portion 40b moves to the fixed electrode 50 side, and thereby the flexible portion 40 is moved to the tip portion (longitudinal direction). The other end portion of the contact portion 2 is deformed so as to approach the fixed contact portion 2.

  As shown in FIGS. 1B and 2, the movable contact portion 3 has a normal axis direction of one surface 1a of the base substrate 1 (in the present embodiment, equal to the thickness direction of the base substrate 1) as a central axis O. It is formed in a truncated cone shape. Therefore, the movable contact portion 3 according to the present embodiment has a perfect circular outer peripheral shape in an orthogonal plane orthogonal to the central axis O. In the movable contact portion 3, one bottom surface (upper bottom surface in FIG. 2) having a larger diameter is on the flexible portion 40 side, and the other bottom surface (lower bottom surface in FIG. 2) is on the base substrate 1 side. In form, it is fixed to the flexible part 40. Therefore, the outer peripheral surface 3 a of the movable contact portion 3 is inclined so as to be separated from the central axis O as the distance from the one surface 1 a of the base substrate 1 is increased.

  A method of forming the movable contact portion 3 and the movable contact support portion 4 described above will be described with reference to FIG. In the following description, an example in which Au is used as a material for the conductor portion 40b, the support portion 41, and the movable contact portion 3 will be described.

  First, the conductor layer 71 serving as the basis of the conductor portion 40b is formed by sputtering on one surface side in the thickness direction of the silicon substrate 70 serving as the basis of the base portion 40a. After the conductor layer 71 is formed, a resist layer 72 is formed on the conductor layer 71. An opening 72 a for forming the movable contact portion 3 is formed in the resist layer 72. The opening 72a is formed to have a smaller inner diameter as the distance from the conductor layer 71 increases (the inner surface of the opening 72a is formed in a reverse taper shape). In addition, a rectangular opening (not shown) for forming the support portion 41 is formed in the resist layer 72. After the resist layer 72 is formed in this way, the inside of each of the opening 72a for the movable contact portion 3 and the opening for the support portion 41 is a gap by electroplating using Au using the conductor layer 71 as a seed layer. The movable contact portion 3 and the support portion 41 are formed by being deposited so as to be embedded without being formed. Thereafter, the resist layer 72 is removed, and the silicon substrate 70 and the conductor layer 71 are processed into desired shapes, whereby the movable contact support portion 4 in which the movable contact portion 3 is formed on the flexible portion 40 is obtained.

  As shown in FIG. 1A, the fixed contact portion 2 has a contact surface 20a described later that is elastically contacted with the outer peripheral surface 3a of the movable contact portion 3 in the direction along the radial direction in the orthogonal plane. A plurality of (three in this embodiment) contact portions 20 are provided. Each contact portion 20 is supported by a frame body portion 21 having a hollow portion 21 a that surrounds the projection region P of the movable contact portion 3 onto one surface 1 a of the base substrate 1. In the illustrated example, the outer peripheral shape of the frame body portion 21 is a square shape, but this does not mean that the frame body portion 21 is limited to a square outer peripheral shape.

  The hollow portion 21a includes a plurality of (three in the illustrated example) first space portions 21b and a plurality of first spaces having a longitudinal direction in the radial direction of a circle centered on the central axis O in the orthogonal plane. It is comprised with the 2nd space part 21c which connects the part 21b mutually. The second space portion 21 c is formed in a circular shape having an inner diameter larger than the outer diameter of the movable contact portion 3 (the outer diameter of the bottom surface on the flexible portion 40 side) with the central axis O as the center. In the hollow portion 21a, the angles between the center lines of the adjacent first space portions 21b in the orthogonal plane are all equal (in the present embodiment, the number of the first space portions 21b is three, so that 120 Every time). Therefore, the shape of the cavity 21a in the orthogonal plane is three-fold rotationally symmetric.

  The contact portion 20 is formed in a rectangular parallelepiped shape, and as shown in FIG. 1A, the longitudinal direction is a circle centered on the central axis O in the longitudinal direction of the first space portion 21b (that is, in the orthogonal plane). ) And one end side in the longitudinal direction exists in the second space portion 21c, and the other end side in the longitudinal direction exists in the first space portion 21b. That is, each contact portion 20 is rotationally symmetric with the center axis O as the rotation axis and the rotational positions as many as the contact portions 20 in the orthogonal plane (that is, the number of the contact portions 20 is 3 in this embodiment). To three-fold rotational symmetry).

  As for this contact part 20, the side surface of the one end side (namely, central axis O side) of the longitudinal direction is used as the above-mentioned contact surface 20a. As shown in FIG. 1B, the contact surface 20 a is inclined so as to be separated from the central axis O as it is away from the one surface 1 a of the base substrate 1. The inclination angle θ (see FIG. 1B) of the contact surface 20a is preferably substantially equal to the inclination angle φ (see FIG. 1B) of the outer peripheral surface 3a of the movable contact portion 3. Moreover, it is preferable that the curvature of the contact surface 20a in the said orthogonal surface is a value a little larger than the curvature of the outer peripheral surface 3a in the said orthogonal surface. If it does in this way, the contact area at the time of the contact surface 20a elastically contacting the outer peripheral surface 3a can be increased. On the other hand, the width dimension of the contact portion 20 (the dimension in the direction orthogonal to the radial direction in the orthogonal plane) is the width dimension of the first space portion 21b (the dimension in the direction orthogonal to the radial direction in the orthogonal plane). A little smaller. As a result, both inner side surfaces in the width direction of the first space portion 21 b constitute a guide portion that sandwiches the contact portion 20. According to the guide part, even if the contact part 20 tries to move in a direction other than the radial direction, the contact part 20 hits the guide part, and the movement of the contact part 20 in a direction other than the specified direction (the radial direction) is obstructed. Then, the contact part 20 is moved in a direction along the radial direction.

  A contact pressure spring portion 22 integrally connects the side surface on the other end side in the longitudinal direction of the contact portion 20 and the inner surface of the first storage portion 21b facing the side surface.

  The contact pressure spring part 22 is formed in a shape (elastic shape) that can be expanded and contracted in a direction along the radial direction. Therefore, the contact portion 20 is supported by the frame body portion 21 so as to be able to advance and retreat in the direction along the radial direction. The natural length of the contact pressure spring portion 22 (the length in the direction along the radial direction when no load is applied to the contact pressure spring portion 22) is the contact surface 20a of the contact portion 20 in the central axis O direction. And a length at which the contact portion 20 can be disposed at a position where the outer peripheral surface 3a of the movable contact portion 3 overlaps.

  By the way, in the fixed contact part 2 in this embodiment, as shown to Fig.1 (a), two contact pressure spring parts 22 are provided with respect to the one contact part 20, respectively. The two contact pressure spring portions 22 are separated from each other in the direction orthogonal to the radial direction in the orthogonal plane, thereby making it difficult for the contact portion 20 to move in a direction other than the radial direction. . In addition, although the contact pressure spring part 22 in this embodiment is formed in the arc shape (bow shape) which became convex in the direction orthogonal to the said radial direction in the said orthogonal plane, it is not limited to this shape, What is necessary is just to be formed in the form which can be expanded-contracted in the direction along the said radial direction.

  In the fixed contact portion 2 described above, in order to make the contact portion 20 movable in the direction along the radial direction, as shown in FIG. It is necessary to form a gap S between the first surface 1a.

  Hereinafter, a method for forming the fixed contact portion 2 having the gap S with the one surface 1a of the base substrate 1 will be described with reference to FIG. In the following description, an example in which a glass substrate is used as the base substrate 1 and Au is used as the material of the fixed contact portion 2 will be described.

  First, a sacrificial layer 80 is formed on one surface 1a side of the base substrate 1 by using a CVD method or the like (see FIG. 4A). As a material for the sacrificial layer 80, Cu or the like can be used. Next, a seed layer 81 made of Au is formed so as to cover the sacrificial layer 80 by using a CVD method or the like, and the structure shown in FIG. 4B is obtained. After the seed layer 81 is formed, a resist layer 82 is formed on the seed layer 81, and this resist layer 82 is patterned into a desired shape using a photolithography technique (the shape of the desired fixed contact portion 2). After that, the plating layer 83 made of Au is formed by depositing Au on the seed layer 81 by electroplating to obtain the structure shown in FIG. After the plating layer 83 is formed, the resist layer 82 is removed using an etching technique, and then an unnecessary portion of the seed layer 81 (a portion of the seed layer 81 exposed from the plating layer 83) 81a is removed. The sacrificial layer 80 is exposed (see FIG. 4D). Finally, by removing the sacrificial layer 81, as shown in FIG. 4E, the fixed contact portion 2 having a gap S between the surface 1a of the base substrate 1 is obtained. Note that the signal line 6 and the fixed electrode 50 may be formed simultaneously with the formation of the fixed contact portion 2.

  Another example of the method for forming the fixed contact portion 2 will be described with reference to FIG. First, the concave portion 1b is formed on one surface 1a side of the base substrate 1a by using a sand blast technique or an etching technique (see FIG. 5A). Thereafter, a sacrificial layer 80 is formed in the recess 1b of the base substrate 1 by using a CVD method or the like, and then the surface of the sacrificial layer 80 (the upper surface in FIG. 5B) is the same as the one surface 1a of the base substrate 1. A planarization process by CMP is performed so as to be positioned on a plane, and a structure shown in FIG. 5B is obtained. Thereafter, a seed layer 81 is formed by the same method as described above (see FIG. 5C), a resist layer 82 and a plating layer 83 are formed (see FIG. 5D), and the resist layer 82 is formed. Then, unnecessary portions 81a of the seed layer 81 are removed (see FIG. 5E), and the sacrificial layer 81 is removed, so that a gap is formed between the surface of the base substrate 1 and the surface of the base substrate 1, as shown in FIG. A fixed contact portion 2 having S is obtained. Such a fixed contact portion 2 is not limited to the above-described method, and can be formed using a known micromachining technique (for example, a bulk micromachining technique).

  In the micro electromechanical switch of the present embodiment described above, the movable contact portion 3 and the fixed contact portion 2 are separated from each other when the actuator 5 is not driven, and the pair of signal lines 6A and 6B is cut off. (Off state). When the actuator 5 is driven, the flexible portion 40 is deformed as described above, and the movable contact portion 3 moves to the fixed contact portion 2 side (the lower side in FIG. 1B). Thereby, the movable contact portion 3 enters a space portion surrounded by the contact surface 20a of each contact portion 20. Since the contact surface 20a of the contact portion 20 overlaps the outer peripheral surface 3a of the movable contact portion 3 in the direction of the central axis O, the outer peripheral surface 3a of the movable contact portion 3 abuts on the contact surface 20a of each contact portion 20 respectively. .

  When the movable contact portion 3 further moves from this state (moves downward in FIG. 1B), the outer peripheral surface 3a of the movable contact portion 3 slides on the contact surface 20a. Since each of the outer peripheral surface 3a and the contact surface 20a is inclined away from the central axis O as the distance from the one surface 1a of the base substrate 1 increases, the contact portion 20 moves as the movable contact portion 3 moves toward the base substrate 1 side. Is moved away from the projection area P (to the first space portion 21b side). As the contact portion 20 moves to the first space portion 21b in this way, the contact pressure spring portion 22 is compressed. Therefore, the contact portion 20 has a force corresponding to the restoring force of the contact pressure spring portion 22 as a movable contact. Press the part 3.

  Here, the direction of the force with which the contact portion 20 presses the movable contact portion 3 is a direction along the radial direction of a circle centering on the central axis O in the orthogonal plane (in the direction of the central axis O of the movable contact portion 3). Crossing direction). In addition, each contact portion 20 has a rotational symmetry (three-fold rotational symmetry in the present embodiment) having rotational positions as many as the number of the contact portions 20 with the central axis O of the movable contact portion 3 as a rotation axis in the orthogonal plane. Therefore, if the sum of the unit direction vectors of the force with which the contact portion 20 presses the movable contact portion 3 is a zero vector, and the magnitude of the force with which the contact portion 20 presses the movable contact portion 3 is equal. The contact pressure between each contact portion 20 and the movable contact portion 3 is equal. Moreover, since the number of the contact parts 20 is three, the force which the one contact part 20 presses the movable contact part 3 can be received in the two other contact parts 20, and the contact part 20 becomes a movable contact. Even when there is a bias in the force that presses the portion 3, compared to the case where the number of the contact portions 20 is two or four, each contact portion 20 is applied to the movable contact portion 3 with equal contact pressure. Can be contacted.

  As described above, when the contact surface 20a of each contact portion 20 is elastically contacted with the outer peripheral surface 3a of the movable contact portion 3, the movable contact portion 3 and the fixed contact portion 2 are electrically connected. The wires 6A and 6B are electrically connected by the fixed contact portion 2, the movable contact portion 3, the conductor portion 40b, and the support portion 41 (ON state).

  Thereafter, when the drive of the actuator 5 is stopped, the flexible portion 40 returns to the shape before deformation (see FIG. 2), and the movable contact portion 3 moves in a direction away from the fixed contact portion 2. As a result, the movable contact portion is moved. The part 3 is separated from the fixed contact part 2, and the pair of signal lines 6A and 6B is disconnected (OFF state).

  As described above, according to the microelectromechanical switch of the present embodiment, if the magnitude of the force with which the contact portion 20 presses the movable contact portion 3 is equal, the contact portion 20 is moved between each contact portion 20 and the movable contact portion 3. The contact pressures of the contact portions 20 are equal to each other, and even when the force that the contact portion 20 presses the movable contact portion 3 is biased, the number of contact portions 20 is two or four. For example, each contact portion 20 can be brought into contact with the movable contact portion 3 with an equal contact pressure, so that the contact state between the movable contact portion 3 and the fixed contact portion 2 is stabilized. The occurrence of sticking can be suppressed, and the contact reliability between the movable contact portion 3 and the fixed contact portion 2 can be improved.

  By the way, when the moving direction of the movable contact portion 3 and the contact direction of the movable contact portion 3 and the fixed contact portion 2 are substantially the same direction, the contact pressure between the movable contact portion 3 and the fixed contact portion 2 is Depending on the magnitude of the force that moves the movable contact portion 3 toward the fixed contact portion 2 (driving force of the actuator 5), it is necessary to increase the driving force in order to increase the contact pressure. When an actuator using electrostatic attraction is employed as the actuator 5 as in the embodiment, it is necessary to apply a relatively high drive voltage, and there is a problem that power consumption is relatively large. With respect to such a problem, in the micro electromechanical switch of the present embodiment, the moving direction of the movable contact portion 3 and the direction in which the contact portion 20 of the fixed contact portion 2 contacts the movable contact portion 3 are substantially orthogonal (crossed). Therefore, the contact pressure between the movable contact portion 3 and the contact portion 20 is determined only by the restoring force of the contact pressure spring portion, and this restoring force is determined by the position of the movable contact portion 3. Therefore, if the movable contact portion 3 can be moved to a predetermined position, a desired contact pressure can be obtained. Therefore, the moving direction of the movable contact portion 3 and the contact between the movable contact portion 3 and the fixed contact portion 2 can be obtained. Compared with the case where the direction is substantially the same, the power consumption can be reduced. Further, if the frictional force between the outer peripheral surface 3a of the movable contact portion 3 and the contact surface 20a of the contact portion 20 is reduced, the driving force required to move the movable contact portion 3 to a predetermined position is further reduced. Therefore, further reduction in power consumption can be achieved.

  Furthermore, in the micro electromechanical switch of the present embodiment, the outer peripheral surface 3a of the movable contact portion 3 is inclined so as to move away from the central axis O as the distance from the one surface 1a of the base substrate 1 increases. The contact surface 20a is also inclined so as to be away from the central axis O as the distance from the one surface 1a of the base substrate 1 increases. Therefore, the movable contact portion 3 can easily enter the space surrounded by the contact portion 20 in the fixed contact portion 2, and the outer peripheral surface 3a can easily slide on the contact surface 20a (improves slidability). 5 power consumption can be reduced. In addition, microscopically, since the outer peripheral surface 3a of the movable contact portion 3 and the contact surface 20a of the contact portion 20 are parallel, the outer peripheral surface 3a of the movable contact portion 3 and the contact surface 20a of the contact portion 20 are Since the area of the contact portion can be increased, the contact resistance can be lowered, and deterioration of on-resistance and occurrence of sticking can be suppressed. Such an effect is such that either one of the outer peripheral surface 3a of the movable contact portion 3 and the contact surface 20a of each contact portion 20 is inclined so as to move away from the central axis O as the distance from the one surface 1a of the base substrate 1 increases. It is more effective to incline both as described above.

  In the present embodiment, since the inclination angle of the outer peripheral surface 3a and the inclination angle of the contact surface 20a are the same angle, the outer peripheral surface 3a can be more easily slid on the contact surface 20a. The area of the contact portion between the outer peripheral surface 3a and the contact surface 20a of the contact portion 20 can be further increased. A space in which the movable contact portion 3 is surrounded by the contact portion 20 in the fixed contact portion 2 by forming a corner portion of the movable contact portion 3 facing the fixed contact portion 2 in a chamfered shape or an R shape. Further, it is possible to prevent the movement of the movable contact portion 3 from being hindered by the corner portion hitting the contact surface 20a.

  Further, in the micro electromechanical switch of the present embodiment, the fixed contact portion 2 has the contact pressure spring portion 22 that elastically contacts the contact surface 20a of the contact portion 20 with the outer peripheral surface 3a of the movable contact portion 3, respectively. Therefore, the contact surface 20a of the contact portion 20 is a movable contact as compared with the case where only one contact pressure spring portion 22 is provided for the contact portion 20. Since it becomes easy to elastically contact the outer peripheral surface 3a of the portion 3 in the direction along the radial direction in the orthogonal plane, the contact reliability is improved. Furthermore, since the guide portion is provided, the contact portion 20 is hardly displaced in a direction other than the direction along the radial direction in the orthogonal plane (because it is moved along the radial direction). Since the contact surface 20a of the contact portion 20 is easily elastically contacted with the outer peripheral surface 3a of the movable contact portion 3 in the direction along the radial direction, the contact reliability is improved.

  Note that the microelectromechanical switch of this embodiment is merely an embodiment of the present invention, and is not intended to limit the technical scope of the present invention to that of this embodiment, but to the spirit of the present invention. Changes can be made without departing from the scope. For example, the number of contact portions 20 is not limited to three, and may be an integer multiple of 3 (3n; where n is an integer of 1 or more). In this case, each contact portion 20 has a rotational symmetry (that is, 3n-fold rotational symmetry) in which the center axis O is the rotational axis and the number of contact portions 20 (ie, 3n) has rotational positions within the orthogonal plane. If they are arranged, the same effect can be obtained. Further, the outer peripheral shape of the movable contact portion 3 is a regular polygonal shape having sides equal to or an integral multiple of the number of the contact portions 20 (for example, the number of the contact portions 20 is 3 as in the present embodiment). For example, a regular triangular shape or a regular hexagonal shape).

  Further, in the micro electromechanical switch of the present embodiment, the actuator 5 using an electrostatic attraction is illustrated, but the actuator 5 using a piezoelectric effect can also be adopted. The actuator 5 using the piezoelectric effect is formed by sequentially laminating a lower electrode (not shown), a piezoelectric material part (not shown), and an upper electrode (not shown) on the flexible portion 40. The flexible portion 40 is deformed by applying a predetermined driving voltage between the upper electrode and the lower electrode. Since the actuator 5 using such a piezoelectric effect can employ a conventionally well-known actuator, detailed description thereof will be omitted.

The actuator 5 using such a piezoelectric effect can increase the amount of deformation of the flexible portion 40 while suppressing power consumption as compared with an actuator using electrostatic attraction. For example, even if a voltage of about 30V is required for a device using electrostatic attraction, the flexible portion 40 can be deformed to the same extent with a voltage of about 5 to 10V using a piezoelectric effect. Become. Therefore, by using the actuator 5 using the piezoelectric effect, it is possible to widen the distance between the movable contact portion 3 and the fixed contact portion 2 while reducing power consumption, and to reduce signal leakage. Can be improved. In addition, if a piezoelectric material part is a lead-type piezoelectric material, PZT, what added the impurity to PZT, PMN-PZT, etc. are employable, for example. In addition, the material of the piezoelectric material portion is not limited to the lead-based piezoelectric material, and for example, KNN (potassium sodium niobate), KN (KNbO ₃ ), NN (NaNbO ₃ ), and KNN have impurities (for example, Li, Nb, Lead-free piezoelectric materials (lead-free piezoelectric ceramics) such as those added with Ta, Sb, Cu, etc.) can be employed. Here, the above-described lead-based piezoelectric material, KNN, KN, NN, and the like have a larger piezoelectric constant than AlN, ZnO, and the like. Therefore, if the lead-based piezoelectric material described above, KNN, KN, NN, or the like is used as the material of the piezoelectric material portion, even if the drive voltage value is the same, compared to the case where AlN, ZnO, or the like is used, The deformation amount of the flexible portion 40 can be increased. If a lead-free piezoelectric material such as KNN is used as the material of the piezoelectric material portion, the environmental load can be reduced.

  The actuator 5 may be of a hybrid type having a main drive means (not shown) using a piezoelectric effect and a sub drive means (not shown) using an electrostatic attractive force. When such an actuator 5 is used, when closing the contact, the main drive means is first driven to move the movable contact portion 3 to the fixed contact portion 2 side, so that the movable contact portion 3 becomes the fixed contact portion 2. After the contact, the auxiliary driving means is driven and the position of the movable contact portion 3 is adjusted, whereby the contact pressure between the movable contact portion 3 and the contact portion 20 can be adjusted to a desired value.

  In the above example, Au is exemplified as the material of the fixed contact portion 2, the movable contact portion 3, the conductor portion 40b, the fixed electrode 50, and the signal line 6. However, in addition to Au, Ni, Ag, Cu , Pd, Rh, Ru, Pt, Ir, Os, and alloys containing at least one of them can be used. The fixed contact portion 2, the movable contact portion 3, the conductor portion 40b, the fixed electrode 50, and the signal line 6 may be formed using a plurality of metal materials. This also applies to Embodiment 2 and Reference Examples 1 and 2 described later.

(Embodiment 2)
As shown in FIGS. 6 and 7, the microelectromechanical switch of the present embodiment is mainly different from the first embodiment in the configuration of the fixed contact portion 2 and the other configurations are the same as those in the first embodiment. The same reference numerals are assigned to the configurations of and the description is omitted. In addition, illustration of the movable contact support part 4 is abbreviate | omitted in FIG.7 (b).

  As shown in FIG. 6, the fixed contact portion 2 in the present embodiment includes a substantially square base portion 23 formed on the one surface 1 a side of the base substrate 1. On the side opposite to the base substrate 1 side in the base portion 23 (upper surface side in FIG. 6), a frame body portion 21 is formed. The frame body portion 21 in the present embodiment has a circular cavity portion 21 a and the outer peripheral shape is the same as the outer peripheral shape of the base portion 23.

  Then, as shown in FIGS. 7A and 7B, a plurality of contact portions 20 (three in this embodiment) project from the portion of the base portion 23 exposed in the hollow portion 21a. The contact portion 20 in the present embodiment is formed in a wall shape in which the thickness (the dimension in the direction along the radial direction in the orthogonal plane) is reduced so as to have sufficient flexibility (elasticity), The cross-sectional shape in the plane parallel to the orthogonal plane is an arc (arc). Each contact portion 20 has a rotational symmetry with the concave surface facing the central axis O side, and having the rotational position as many as the number of the contact portions 20 with the central axis O as the rotation axis in the orthogonal plane (that is, contact in this embodiment). Since the number of the parts 20 is 3, they are arranged in a form that is three-fold rotationally symmetric). Such a fixed contact portion 2 can be formed by using, for example, a well-known micromachining technique (for example, bulk micromachining technique).

  Therefore, in the contact part 20 in this embodiment, a concave surface becomes the contact surface 20a with the movable contact part 3. FIG. In addition, the curvature in the said orthogonal surface of the contact surface (the said concave surface) 20a of the contact part 20 is equal to the curvature of the outer peripheral surface 3a of the movable contact part 3, and the contact surface 20a of the contact part 20 and a central axis The distance from O is larger than the radius of the other bottom surface of the movable contact portion 3 and smaller than the radius of the one bottom surface. In other words, the contact portion 20 in the present embodiment has a shape in which a cylinder having an inner diameter larger than the diameter of the other bottom surface of the movable contact portion 3 and smaller than the diameter of the one bottom surface is divided into three in the circumferential direction.

  In the micro electromechanical switch of the present embodiment described above, the movable contact portion 3 and the fixed contact portion 2 are separated from each other when the actuator 5 is not driven, and the pair of signal lines 6A and 6B is cut off. (Off state). When the actuator 5 is driven, the flexible portion 40 is deformed so that the movable contact portion 3 moves to the fixed contact portion 2 side (the lower side in FIG. 7B). As a result, the movable contact portion 3 enters the space portion surrounded by the contact surface 20 a of each contact portion 20.

  Here, since the distance between the concave surface of the contact portion 20 and the central axis O is larger than the radius of the other bottom surface of the movable contact portion 3 and smaller than the radius of the one bottom surface, it is surrounded by the contact surface 20a of each contact portion 20. The inner diameter of the space portion is larger than the diameter of the other bottom surface of the movable contact portion 3 and smaller than the diameter of the one bottom surface. Therefore, as the movable contact portion 3 moves to the base substrate 1 side, the contact portion 20 is deformed so as to fall to the opposite side to the central axis O side, whereby the outer peripheral surface 3a of the movable contact portion 3 is It abuts on each contact surface 20a of the contact portion 20. When the contact portion 20 is deformed in this way, the contact portion 20 tries to return to its original shape by its own restoring force, and a contact pressure corresponding to this restoring force is generated between the contact surface 20a and the outer peripheral surface 3a. . Therefore, the contact surface 20a of the contact portion 20 is in elastic contact with the outer peripheral surface 3a of the movable contact portion 3 from the direction along the radial direction in the orthogonal plane.

  Thus, the direction of the force with which the contact portion 20 presses the movable contact portion 3 is the direction along the radial direction of the circle centered on the central axis O in the orthogonal plane (the direction of the central axis O of the movable contact portion 3). In the direction that intersects). In addition, each contact portion 20 has a rotational symmetry (three-fold rotational symmetry in the present embodiment) having rotational positions as many as the number of the contact portions 20 with the central axis O of the movable contact portion 3 as a rotation axis in the orthogonal plane. Therefore, if the sum of the unit direction vectors of the force with which the contact portion 20 presses the movable contact portion 3 is a zero vector, and the magnitude of the force with which the contact portion 20 presses the movable contact portion 3 is equal. The contact pressure between each contact portion 20 and the movable contact portion 3 is equal. Moreover, since the number of the contact parts 20 is three, the force which the one contact part 20 presses the movable contact part 3 can be received in the two other contact parts 20, and the contact part 20 becomes a movable contact. Even when there is a bias in the force that presses the portion 3, compared to the case where the number of the contact portions 20 is two or four, each contact portion 20 is applied to the movable contact portion 3 with equal contact pressure. Can be contacted.

  As described above, when the contact surface 20a of each contact portion 20 is elastically contacted with the outer peripheral surface 3a of the movable contact portion 3, the movable contact portion 3 and the fixed contact portion 2 are electrically connected. The wires 6A and 6B are electrically connected by the fixed contact portion 2, the movable contact portion 3, the conductor portion 40b, and the support portion 41 (ON state).

  Thereafter, when the driving of the actuator 5 is stopped, the flexible portion 40 returns to the shape before the deformation (see FIG. 6), and the movable contact portion 3 moves away from the fixed contact portion 2. As a result, the movable contact portion is moved. The part 3 is separated from the fixed contact part 2, and the pair of signal lines 6A and 6B is disconnected (OFF state).

  As described above, according to the micro electromechanical switch of the present embodiment, the same effect as in the first embodiment can be obtained. Further, in this embodiment, since the contact portion 20 also serves as the contact pressure spring portion 22, the fixed contact portion 2 can be made simpler than that of the first embodiment, and the fixed contact portion 2 can be easily formed. Can be formed.

(Reference Example 1)
As shown in FIGS. 8 and 9, the microelectromechanical switch of this reference example is mainly different from the first embodiment in the configuration of the fixed contact portion 2, and the other configurations are the same as those in the first embodiment. The same reference numerals are assigned to the configurations of and the description is omitted. In addition, illustration of the movable contact support part 4 is abbreviate | omitted in FIG.9 (b).

  As shown in FIG. 9A, the fixed contact portion 2 in the present reference example has an outer peripheral surface 3a of the movable contact portion 3 in a direction along the radial direction of a circle centered on the central axis O in the orthogonal plane. A plurality of (two in this reference example) contact portions 20 having contact surfaces 20a that are elastically contacted with each other are provided. Each contact portion 20 is supported by a frame body portion 21 having a hollow portion 21 a that surrounds the projection region P of the movable contact portion 3 onto one surface 1 a of the base substrate 1. In the illustrated example, the outer peripheral shape of the frame body portion 21 is a square shape, but this does not mean that the frame body portion 21 is limited to a square outer peripheral shape.

  The hollow portion 21a in the present reference example is formed in a substantially square shape centering on the central axis O in the orthogonal plane (that is, the frame body portion 21 is formed of a square frame).

  The contact portion 20 in the present reference example is formed in a rectangular parallelepiped shape, and the diameter of a circle centering on the central axis O in the short plane direction (length direction, left-right direction in FIG. 9A) in the orthogonal plane. The contact surface 20a is formed on one end side (that is, the central axis O side) in the short direction, and is disposed inside the hollow portion 21a in a shape along the direction. Further, the two contact portions 20 are arranged at positions that are point-symmetric with respect to the central axis O in the orthogonal plane. That is, each contact portion 20 is rotationally symmetric with the center axis O as the rotation axis and the rotational positions as many as the contact portions 20 in the orthogonal plane (that is, the number of the contact portions 20 is 2 in this reference example). To two-fold rotational symmetry).

  Further, as shown in FIG. 9B, the contact surface 20 a of the contact portion 20 is inclined so as to be away from the central axis O as it is away from the one surface 1 a of the base substrate 1. The inclination angle θ of the contact surface 20a is preferably substantially equal to the inclination angle φ of the outer peripheral surface 3a of the movable contact portion 3, and the curvature of the contact surface 20a in the orthogonal plane is within the orthogonal plane. It is preferable to make the value slightly larger than the curvature of the outer peripheral surface 3a. If it does in this way, the contact area at the time of the contact surface 20a elastically contacting the outer peripheral surface 3a can be increased.

  Such a contact portion 20 is integrally connected to the frame body portion 21 by a contact pressure spring portion 22. The contact pressure spring portion 22 is formed in a belt shape having a longitudinal direction in a direction orthogonal to the radial direction in the orthogonal plane, and a longitudinal direction (width direction, Each side surface in the vertical direction in FIG. 9A and the inner side surface of the cavity 21a facing each side surface are integrally connected (see FIG. 9A).

  Therefore, the contact part 20 in the present reference example is supported by the frame body part 21 so as to be able to advance and retreat in the direction along the radial direction. Further, the shape of the contact pressure spring portion 22 is set such that the contact portion 20 can be disposed at a position where the contact surface 20a of the contact portion 20 and the outer peripheral surface 3a of the movable contact portion 3 overlap in the direction of the central axis O. The above-described fixed contact portion 2 of this reference example is formed using a known micromachining technique (for example, bulk micromachining technique) in addition to the method described in the first embodiment (the method shown in FIGS. 4 and 5). Can do.

  In the microelectromechanical switch of this reference example described above, the movable contact portion 3 and the fixed contact portion 2 are separated from each other when the actuator 5 is not driven, and the pair of signal lines 6A and 6B is blocked. (Off state). When the actuator 5 is driven, the flexible portion 40 is deformed so that the movable contact portion 3 moves to the fixed contact portion 2 side (the lower side in FIG. 9B). Thereby, the movable contact portion 3 enters a space portion surrounded by the contact surface 20a of each contact portion 20. Since the contact surface 20a of the contact portion 20 overlaps the outer peripheral surface 3a of the movable contact portion 3 in the direction of the central axis O, the outer peripheral surface 3a of the movable contact portion 3 abuts on the contact surface 20a of each contact portion 20 respectively. .

  When the movable contact portion 3 further moves from this state (moves downward in FIG. 9B), the outer peripheral surface 3a of the movable contact portion 3 slides on the contact surface 20a. At this time, each of the outer peripheral surface 3a and the contact surface 20a of the movable contact portion 3 is inclined so as to move away from the central axis O as the distance from the one surface 1a of the base substrate 1 increases. As it moves, the contact portion 20 is moved so as to retreat from the projection region P, so that the contact pressure spring portion 22 is deformed. Therefore, the contact portion 20 presses the movable contact portion 3 with a force corresponding to the restoring force of the contact pressure spring portion 22.

  Here, the direction of the force with which the contact portion 20 presses the movable contact portion 3 is a direction along the radial direction of a circle centered on the central axis O in the orthogonal plane. In addition, each contact portion 20 has a rotational symmetry (in this reference example, a two-fold rotational symmetry) having rotational positions as many as the number of the contact portions 20 with the central axis O of the movable contact portion 3 as the rotational axis in the orthogonal plane. Therefore, if the sum of the unit direction vectors of the force with which the contact portion 20 presses the movable contact portion 3 is a zero vector, and the magnitude of the force with which the contact portion 20 presses the movable contact portion 3 is equal. The contact pressures between the contact portions 20 and the movable contact portions 3 are all equal, and the contact portions 20 can be brought into contact with the movable contact portions 3 with an equal contact pressure.

  As described above, when the contact surface 20a of each contact portion 20 is elastically contacted with the outer peripheral surface 3a of the movable contact portion 3, the movable contact portion 3 and the fixed contact portion 2 are electrically connected. The wires 6A and 6B are electrically connected by the fixed contact portion 2, the movable contact portion 3, the conductor portion 40b, and the support portion 41 (ON state).

  Thereafter, when the driving of the actuator 5 is stopped, the flexible portion 40 returns to the shape before the deformation (see FIG. 8), and the movable contact portion 3 moves away from the fixed contact portion 2. As a result, the movable contact point is moved. The part 3 is separated from the fixed contact part 2, and the pair of signal lines 6A and 6B is disconnected (OFF state).

  As described above, according to the microelectromechanical switch of the present reference example, if the magnitude of the force with which the contact portion 20 presses the movable contact portion 3 is equal, the contact portion 20 and the movable contact portion 3 can be Since the contact pressures of the movable contact portion 3 and the fixed contact portion 2 can be brought into contact with the movable contact portion 3 with equal contact pressure, the contact state between the movable contact portion 3 and the fixed contact portion 2 is stabilized. As a result, deterioration of on-resistance and occurrence of sticking can be suppressed, and contact reliability between the movable contact portion 3 and the fixed contact portion 2 can be improved.

  Also in this reference example, since the moving direction of the movable contact portion 3 and the direction in which the contact portion 20 contacts the movable contact portion 3 are substantially orthogonal (crossing), the moving direction of the movable contact portion 3 and Compared with the case where the direction in which the contact portion 20 contacts the movable contact portion 3 is substantially the same direction, the power consumption can be reduced. Further, by reducing the frictional force between the outer peripheral surface 3a of the movable contact portion 3 and the contact surface 20a of the contact portion 20, further reduction in power consumption can be achieved.

  Further, in the micro electromechanical switch of this reference example, the fixed contact portion 2 includes the contact pressure spring portion 22 that elastically contacts the contact surface 20a of the contact portion 20 with the outer peripheral surface 3a of the movable contact portion 3, respectively. The contact surface 20a of the contact portion 20 and the movable contact are compared with the case where only one contact pressure spring portion 22 is provided for the contact portion 20. The outer peripheral surface 3a of the portion 3 is easily contacted in a direction along the radial direction of a circle centered on the central axis O in an orthogonal plane orthogonal to the central axis O of the movable contact portion 3, thereby further improving contact stability. Can be improved.

(Reference Example 2)
As shown in FIGS. 10 and 11, the microelectromechanical switch of this reference example is mainly different from the first embodiment in the configuration of the fixed contact portion 2, and the other configurations are the same as those in the first embodiment. The same reference numerals are given to the configurations of and the description is omitted. In addition, illustration of the movable contact support part 4 is abbreviate | omitted in FIG.11 (b).

  The fixed contact portion 2 in the present reference example has a coil shape having a normal direction of the one surface 1a of the base substrate 1 as a central axis direction (both a spiral shape and a constant spiral shape having a constant inner diameter in the direction along the central axis direction). Say). Further, as shown in FIGS. 11A and 11B, the inner diameter of the fixed contact portion 2 is larger than the diameter of the one bottom surface (the upper bottom surface in FIG. 11B) of the movable contact portion 3, and the other bottom surface. It is smaller than the diameter (lower bottom surface in FIG. 11B). Therefore, the inner peripheral surface 2 a of the fixed contact portion 2 becomes a contact surface with the movable contact portion 3. Such a fixed contact portion 2 is formed on the signal line 6 </ b> A so that the central axis thereof coincides with the central axis of the movable contact portion 3. Such a fixed contact portion 2 can be formed by using, for example, a well-known micromachining technique (for example, bulk micromachining technique).

  In the microelectromechanical switch of this reference example described above, the movable contact portion 3 and the fixed contact portion 2 are separated from each other when the actuator 5 is not driven, and the pair of signal lines 6A and 6B is blocked. (Off state). When the actuator 5 is driven, the flexible portion 40 is deformed as described above, so that the movable contact portion 3 is moved to the fixed contact portion 2 side (the lower side in FIG. 11B). Here, the central axis of the fixed contact portion 2 coincides with the central axis O of the movable contact portion 3, and the inner diameter of the fixed contact portion 2 is larger than the diameter of the other bottom surface of the movable contact portion 3, Smaller than the diameter of Therefore, the movable contact portion 3 easily enters the inside of the fixed contact portion 2. Then, the outer peripheral surface 3a of the movable contact portion 3 contacts the inner peripheral surface 2a of the fixed contact portion 2, so that the movable contact portion 3 and the fixed contact portion 2 come into contact with each other. When it is moved to the 1 side, the fixed contact portion 2 is expanded by the movable contact portion 3, whereby the outer peripheral surface 3 a of the movable contact portion 3 and the inner peripheral surface 2 a of the fixed contact portion 2 extend over the entire circumference. And hit it.

  As described above, when the inner peripheral surface 2a of the fixed contact portion 2 is elastically contacted with the outer peripheral surface 3a of the movable contact portion 3, the movable contact portion 3 and the fixed contact portion 2 are electrically connected. The wires 6A and 6B are electrically connected by the fixed contact portion 2, the movable contact portion 3, the conductor portion 40b, and the support portion 41 (ON state).

  Thereafter, when the driving of the actuator 5 is stopped, the flexible portion 40 returns to the shape before the deformation (see FIG. 10), and the movable contact portion 3 moves away from the fixed contact portion 2. As a result, the movable contact portion 3 moves. The part 3 is separated from the fixed contact part 2, and the pair of signal lines 6A and 6B is disconnected (OFF state).

  As described above, according to the microelectromechanical switch of the present reference example, the fixed contact portion 2 is formed in a coil shape, and the movable contact portion 3 is located on the inner side of the fixed contact portion 2. Since the peripheral surface 2a contacts the outer peripheral surface 3a of the movable contact portion 3 over the entire circumference, the fixed contact portion 2 can be brought into contact with the movable contact portion 3 with an equal contact pressure. The contact state with the fixed contact portion 2 is stabilized, and as a result, deterioration of on-resistance and occurrence of sticking can be suppressed, and the contact reliability between the movable contact portion 3 and the fixed contact portion 2 is improved. Can be improved. Moreover, in this reference example, the fixed contact part 2 can be made into a simple shape compared with Embodiment 1, and it becomes possible to form the fixed contact part 2 easily.

  Further, in the micro electromechanical switch of this reference example, the moving direction of the movable contact portion 3 and the direction in which the inner peripheral surface 2a of the fixed contact portion 2 contacts the movable contact portion 3 are substantially orthogonal (intersect). The contact pressure between the movable contact portion 3 and the fixed contact portion 2 is determined only by the restoring force of the fixed contact portion 2, and this restoring force is determined by the position of the movable contact portion 3. Therefore, if the movable contact portion 3 can be moved to a predetermined position, it is possible to obtain a desired contact pressure. Therefore, the moving direction of the movable contact portion 3 and the movable contact portion 3 come into contact with the fixed contact portion 2. Compared with the case where the direction is substantially the same, the power consumption can be reduced. Moreover, if the frictional force between the outer peripheral surface 3a of the movable contact portion 3 and the inner peripheral surface 2a of the fixed contact portion 2 is reduced, the driving force required to move the movable contact portion 3 to a predetermined position is further reduced. Therefore, further reduction in power consumption can be achieved.

  By the way, the fixed contact portion 2 in the present reference example is formed in a spiral shape having a constant inner diameter in the direction along the central axis direction, but the base substrate in the direction along the central axis direction of the fixed contact portion 2. It may be formed in a spiral shape so that the inner diameter gradually decreases as it approaches one side. In this way, the movable contact portion 3 can easily enter the fixed contact portion 2, and the outer peripheral surface 3a can easily slide on the inner peripheral surface 2a, so that contact reliability is further improved. Moreover, microscopically, since the outer peripheral surface 3a of the movable contact portion 3 and the inner peripheral surface 2a of the fixed contact portion 2 are parallel, the contact area between the outer peripheral surface 3a and the inner peripheral surface 2a can be increased. Contact resistance can be lowered, and deterioration of on-resistance and occurrence of sticking can be suppressed. In this case, in the plane including the central axis O of the movable contact portion 3, it is preferable that the inclination angle of the outer peripheral surface 3a and the inclination angle of the inner peripheral surface 2a are equal to each other. 3a can further slip on the inner peripheral surface 2a, and the contact area between the outer peripheral surface 3a and the contact surface 20a can be further increased.

(A) is a fragmentary top view of the principal part of the micro electromechanical switch of Embodiment 1, (b) is the sectional view on the AA line of the figure (a). It is a disassembled perspective view of a micro electromechanical switch same as the above. It is explanatory drawing of the formation method of the movable contact part in the same as the above. It is explanatory drawing of the formation method of the fixed contact part in the same as the above. It is explanatory drawing of the formation method of the fixed contact part in the same as the above. It is a disassembled perspective view of the micro electromechanical switch of Embodiment 2. (A) is a fragmentary top view of the principal part same as the above, (b) is a BB arrow directional cross-sectional view of the figure (a). 3 is an exploded perspective view of a micro electromechanical switch of Reference Example 1. FIG. (A) is the fragmentary top view of the principal part same as the above, (b) is CC sectional view taken on the line of FIG. 10 is an exploded perspective view of a micro electromechanical switch of Reference Example 2. FIG. (A) is a fragmentary top view of the principal part same as the above, (b) is a side view. It is a schematic sectional drawing of the micro electromechanical switch of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base substrate 1a One surface 2 Fixed contact part 3 Movable contact part 3a Outer peripheral surface 4 Movable contact support part 5 Actuator 20 Contact part 20a Contact surface 22 Contact pressure spring part 40 Flexible part O Center axis

Claims (5)

The one surface of the base substrate having a fixed contact portion formed on one surface side of the base substrate and a flexible portion having a movable contact portion formed on a portion facing the fixed contact portion on the one surface side of the base substrate. A movable contact support portion fixed to the side, and an actuator for deforming the flexible portion of the movable contact support portion so that the movable contact portion contacts the fixed contact portion,
The movable contact portion has the normal direction of the one surface of the base substrate as the direction of the central axis,
The fixed contact portion has a contact surface that is elastically contacted with the outer peripheral surface of the movable contact portion in a direction along a radial direction of a circle centering on the central axis in an orthogonal plane orthogonal to the direction of the central axis. Having a plurality of contact portions,
The number of contact parts is an integer multiple of 3,
Each of the contact portions is arranged in a rotationally symmetric manner having the rotational axis as many as the number of contact portions with the central axis as a rotation axis in the orthogonal plane.   2. The micro electro mechanical switch according to claim 1, wherein the outer peripheral surface of the movable contact portion is inclined so as to be separated from the central axis as the distance from the one surface of the base substrate is increased.   3. The microelectromechanical switch according to claim 1, wherein the contact surface of each of the contact portions is inclined so as to be separated from the central axis as the distance from the one surface of the base substrate is increased.   The fixed contact portion is provided with a plurality of contact pressure spring portions for elastically contacting the contact surface of the contact portion with the outer peripheral surface of the movable contact portion for each of the contact portions. Item 4. The microelectromechanical switch according to any one of Items 1 to 3.   The micro electromechanical switch according to any one of claims 1 to 4, wherein the fixed contact portion includes a guide portion that sandwiches the contact portion in a direction orthogonal to the radial direction in the orthogonal plane. .

Images