JP2015175792A - Electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic device capable of improving operational reliability.SOLUTION: An acceleration switch 1 includes: a switch main body 11 including a center electrode 32; a weight part 34 housing the center electrode 32 inside and an inside surface capable of making contact with and detaching from an outside surface of the center electrode 32 and surrounding a periphery of the weight part 34; and a beam part 35 surrounding the periphery of the weight part 34 and elastically supporting the weight part 34 with a frame body 31; a first substrate 12 for sealing the switch main body 11 from below in a gravity direction and including an escape part 56 housing the weight part 34 in a separated state in the gravity direction; and a projection part 70 for projecting to a low end surface on at least one part of the plane facing the low end surface in the gravity direction of the weight part 34 in the escape part 56.

Description

  The present invention relates to an electronic device.

  As one of the electronic devices, an acceleration switch is known in which the contact is open (OFF state) in the initial state and the contact is closed (ON state) when acceleration is input (see, for example, Patent Document 1). ).

Hereinafter, a conventional acceleration switch 100 will be briefly described with reference to FIG.
As shown in FIG. 15, the acceleration switch 100 includes a center electrode 132, a housing hole 133 that houses the center electrode 132 inside, a weight part 134 that can be contacted and separated from the center electrode 132, and a weight part 134. And a beam portion 135 that elastically supports the weight portion 134 between the frame body 131 and a surface facing the sealing substrate provided above and below the frame body 131. Escape portions 156 and 157 which are depressions for allowing displacement of the portion 134 are provided.

  According to this configuration, the center electrode 132 and the weight portion 134 come into contact with each other by the relative movement of the center electrode 132 and the weight portion 134 according to the acceleration input to the acceleration switch 100. As a result, the electrode films 146 and 145 formed on the central electrode 132 and the weight part 134 are electrically connected to each other and are turned on. Such an acceleration switch can be used as a normally-off and omni-directional switch, and can be miniaturized and mass-produced by being manufactured using MEMS (Micro Electro Mechanical Systems) technology. is there.

Japanese Patent No. 4996771

However, in the conventional acceleration switch described above, as shown in FIG. 15, the weight portion 134 sinks in the direction of gravity (from the upper side to the lower side in FIG. 15) due to gravity. There is a shift in the horizontal position between the electrode film 146 formed in the portion located at the protruding portion 136 and the electrode film 145 formed in the portion facing the protruding portion 136 on the outer surface of the central electrode 132, As a result, contact failure between the electrodes may occur, and operation failure may occur. Further, if the acceleration switch is not provided with the escape portions 156 and 157 at the expense of the displacement of the weight portion 134, the upper and lower surfaces of the weight portion 134 are supported by contacting the opposing surfaces of the sealing substrate. Thereby, the sinking of the weight part 134 can be suppressed. However, when acceleration is input in this state, the entire upper and lower surfaces of the weight part 134 and the substrate slide relative to each other, so that the central electrode 132 and the weight part 134 are not affected by the frictional force of both. Contact (separation) may not occur and malfunction may occur.
The present invention has been made in view of such circumstances, and an object thereof is to provide an electronic device capable of improving operation reliability.

In order to solve the above-described problems, an electronic device according to the present invention includes a central electrode, a weight portion in which the central electrode is accommodated on the inner side, and an inner side surface that can be contacted and separated from an outer side surface of the central electrode. A structure substrate that includes a beam portion that surrounds the periphery of the weight portion and elastically supports the weight portion with the support portion; and the structure substrate is sealed from below in the direction of gravity, and the weight portion A lower sealing substrate having a lower housing portion that accommodates in a state of being separated in the gravitational direction, and at least part of a surface of the lower housing portion that faces the lower end surface of the weight portion in the gravitational direction. And a lower protruding portion protruding toward the lower end surface.
According to this configuration, when the weight portion sinks due to gravity (self-weight), the weight portion is supported by the lower support portion provided in the lower accommodating portion, and therefore, the contact between the inner surface of the weight portion and the outer surface of the central electrode is achieved. The deviation of the separation position (horizontal position) can be suppressed. As a result, according to the present invention, even when the weight portion is disposed in the accommodating portion for allowing displacement of the weight portion, the central electrode and the weight portion can be contacted and separated regardless of the action of gravity on the weight portion. Therefore, operation reliability as an electronic device can be improved.

The lower protrusion may be formed at a position symmetrical to the center electrode in plan view.
According to this configuration, since the weight portion can be supported at a position symmetrical with respect to the center electrode, it is possible to suppress variation in sensitivity due to the inclination of the weight portion.

The lower protrusion is made of a material having at least one of conductivity and solid lubricity.
According to this configuration, since the electrostatic force / friction force acting between the lower protruding portion and the weight portion can be suppressed, the weight portion and the lower protruding portion are stuck to each other due to electrostatic attraction, or due to the friction force. It is possible to prevent obstruction of the contact operation with the central electrode of the weight portion and to improve the operation reliability as a further electronic device.

Further, the lower projecting portion is characterized in that the surface of the weight portion facing the lower end surface in the gravitational direction is covered with a film having at least one property of conductivity and solid lubricity.
According to this configuration, since the electrostatic force / friction force acting between the lower protruding portion and the weight portion can be suppressed, the weight portion and the lower protruding portion are stuck to each other due to electrostatic attraction, or due to the friction force. It is possible to prevent obstruction of the contact operation with the central electrode of the weight portion and to improve the operation reliability as a further electronic device. Moreover, since the material of the lower protrusion itself is not limited, for example, it can be formed integrally with the lower sealing substrate using the same material as the lower sealing substrate, and the manufacturing process can be simplified. I can do it.

Further, the structure substrate is sealed from above in the gravitational direction, and an upper sealing substrate including an upper housing portion that houses the weight portion in a state of being separated in the gravity direction, and the weight among the upper housing portions. An upper projecting portion projecting toward the upper end surface is provided on at least a part of the surface of the portion facing the upper end surface in the gravitational direction.
According to this configuration, even when the electronic device according to the present invention is used in the reverse direction in the vertical direction, when the weight portion sinks due to gravity, the electronic device is supported by the upper support portion provided in the upper accommodation portion. I can do it.

The upper protrusion is made of a material having at least one of conductivity and solid lubricity.
According to this configuration, since the electrostatic force / friction force acting between the upper protruding portion and the weight portion can be suppressed, the weight portion due to electrostatic attraction and the upper protruding portion are attached, or the weight portion due to the friction force. Therefore, it is possible to prevent obstruction of the contact / separation operation with the central electrode, and to further improve the operation reliability as an electronic device.

Further, the upper projecting portion is covered with a film having a surface facing the upper end surface in the gravity direction of the weight portion and having at least one of conductivity and solid lubricity.
According to this configuration, since the electrostatic force / friction force acting between the upper protruding portion and the weight portion can be suppressed, the weight portion due to electrostatic attraction and the upper protruding portion are attached, or the weight portion due to the friction force. Therefore, it is possible to prevent obstruction of the contact / separation operation with the central electrode, and to further improve the operation reliability as an electronic device.
In addition, since the material of the upper protrusion itself is not limited, for example, it can be formed integrally with the upper sealing substrate using the same material as the upper sealing substrate, and the manufacturing process can be simplified.

  According to the present invention, the operational reliability of an electronic device can be improved.

It is a top view of the switch body in a 1st embodiment. It is sectional drawing of the acceleration switch equivalent to the AA line of FIG. FIG. 3 is a plan view for explaining a formation position of a protrusion of the switch body shown in FIG. 2. FIG. 5 is a process diagram for explaining a method of manufacturing an acceleration switch, and a sectional view corresponding to FIG. 2. FIG. 5 is a process diagram for explaining a method of manufacturing an acceleration switch, and a sectional view corresponding to FIG. 2. It is explanatory drawing for demonstrating the effect | action of an acceleration switch, Comprising: It is sectional drawing equivalent to FIG. It is sectional drawing of the switch main body in 2nd Embodiment. It is a top view for demonstrating the formation position of the projection part of the switch main body shown in FIG. It is sectional drawing of the switch main body in 3rd Embodiment. It is sectional drawing of the switch main body in 4th Embodiment. It is sectional drawing of the switch main body in 5th Embodiment. It is sectional drawing equivalent to FIG. 11 which shows the modification of 5th Embodiment. It is sectional drawing equivalent to FIG. 11 which shows the modification of 5th Embodiment. In the acceleration switch shown in FIG. 13, it is a figure which illustrates the state which formed the solid lubricating film in the opposing surface with the projection part of a weight. It is a longitudinal cross-sectional view showing the conventional acceleration switch.

Next, an embodiment of the present invention will be described.
<First Embodiment>
[Acceleration switch]
FIG. 1 is a plan view of a switch body 11 (electronic device) in the first embodiment, and FIG. 2 is a cross-sectional view corresponding to the line AA in FIG.
As shown in FIGS. 1 and 2, the acceleration switch 1 of the present embodiment includes a switch body 11 (structure substrate) and a first substrate 12 (lower sealing substrate) that sandwiches the switch body 11 in the thickness direction. And a second substrate 13 (upper sealing substrate).

(About the switch body configuration)
As shown in FIG. 2, the switch body 11 is manufactured by a MEMS technique using a substrate 20 made of, for example, a silicon material or an SOI (Silicon-On-Insulator) material. In the following description, the thickness direction (vertical direction in FIG. 2) of the substrate 20 is simply referred to as the height direction, and in particular, the downward direction from the upper side in FIG. 2 is the gravity direction, and the lower side in FIG. The upper side is the upper side. However, since the acceleration switch 1 according to the present embodiment has an aspect in which the height direction is reversed, the vertical direction is merely an expression for convenience.

As shown in FIGS. 1 and 2, the switch main body 11 is arranged between a frame 31 (support portion), a center electrode 32 arranged inside the frame 31, and between the frame 31 and the center electrode 32. A weight portion 34 having an accommodation hole 33 for accommodating the central electrode 32 inside, and a circular arc shape surrounding the circumference of the weight portion 34, and a beam portion 35 elastically supporting the weight portion 34 with the frame body 31. It is equipped with. In the following description, the circumferential direction of the beam portion 35 is simply referred to as the circumferential direction, and the radial direction of the beam portion 35 is simply referred to as the radial direction.
The frame 31 has a rectangular shape in a plan view (longitudinal sectional view) viewed from the thickness direction, and a through hole 31a having a circular shape in a top view that penetrates the substrate 20 in the thickness direction is formed at the center thereof. .

The center electrode 32 has a cylindrical shape that passes through the center of the frame 31 (the center of the through hole 31a) and extends along the thickness direction. The first bonding film 41 and the second bonding for bonding the first substrate 12 and the second substrate 13 and the switch main body 11 to at least both surfaces of the frame body 31 and the center electrode 32 of the switch body 11, respectively. A film 42 (for example, Au / Ni) is formed. In the illustrated example, a second bonding film 42 is formed on the main surface of the switch body 11 on the other end side in the thickness direction including the weight portion 34 and the beam portion 35.
The weight portion 34 has a circular shape in a plan view, and an accommodation hole 33 that penetrates the substrate 20 in the thickness direction is formed at the center thereof.

  The outer diameter of the weight portion 34 is smaller than the inner diameter of the through hole 31 a of the frame body 31, and the inner diameter of the accommodation hole 33 is larger than the outer diameter of the central electrode 32. Therefore, the weight portion 34 is set with a gap in the radial direction between the inner side surface and the outer side surface of the central electrode 32, and can be brought into and out of contact with the central electrode 32 by input of acceleration to the acceleration switch 1. Is done. In addition, it is preferable that the width | variety in the radial direction of a gap is uniform over the perimeter of the circumferential direction.

  In addition, the other end portion in the thickness direction of the weight portion 34 has an overhang portion 36 that protrudes inward in the radial direction from the one end portion. Electrode films 45 and 46 are provided on at least a portion of the inner side surface of the weight portion 34 located on the overhang portion 36 and on a portion of the outer surface of the central electrode 32 facing the overhang portion 36, respectively. Is formed. Therefore, in the initial state, the acceleration switch 1 is in a state (OFF state) in which the electrode films 45 and 46 are opposed to each other across the gap. The electrode films 45 and 46 are separately connected to the second bonding film 42 described above.

The beam portion 35 is formed thinner than the frame body 31 and the weight portion 34 and can be elastically deformed. Specifically, the beam portion 35 connects the frame-shaped arc portion 51 that surrounds the circumference of the weight portion 34 over almost the entire circumference, and the circumferential end of the arc portion 51 and the weight portion 34. It consists of a weight side connection part 52 and a frame side connection part 53 that connects the other end of the arc part 51 in the circumferential direction and the frame 31.
The circular arc portion 51 extends with a constant curvature radius over the entire circumference in the circumferential direction, and faces in a state where both ends in the circumferential direction are close to each other.

(Regarding the configuration of the first substrate and the second substrate)
As shown in FIG. 2, the first substrate 12 is made of, for example, a glass material such as borosilicate glass and the like, and the plan view outer shape has the same shape as the switch body 11, and the switch body 11 is sealed from below in the gravity direction. Stop. The first substrate 12 is bonded to the frame body 31 and the center electrode 32 of the switch body 11 via the first bonding film 41. Further, of the main surface of the first substrate 12 on the switch body 11 side, the portion located other than the frame body 31 and the central electrode 32 allows displacement of the weight portion 34 (the weight portion 34 is separated in the gravity direction). The escape portion 56 (lower accommodation portion) is formed. As shown in FIG. 2, a protrusion 70 (lower projecting portion) is provided at a position corresponding to the lower side of the weight portion 34 on the upper surface of the escape portion 56.

  The protrusion 70 is made of, for example, a glass material or the like, and has a shape protruding from the upper surface of the escape portion 56 toward the bottom surface (the lower end surface in the direction of gravity) of the weight portion 34 (in FIG. 2, a trapezoidal shape in a longitudinal sectional view). Become. When the weight part 34 sinks toward the protrusion part 70 due to its own weight, the protrusion part 70 contacts the bottom surface of the weight part 34 and supports the weight part 34 at a predetermined height. Here, the predetermined height means that the end surfaces (the upper surfaces in FIG. 2) on the side where the electrode films 45 and 46 of the central electrode 32 and the weight portion 34 are formed in the gravitational direction maintain a horizontal positional relationship. Although the height is preferable, at least the lower end of the electrode film 46 provided on the outer surface of the central electrode 32 and the upper end of the electrode film 45 provided on the outer surface of the overhanging portion 36 are the same as those in FIG. The height is higher than the height at which contact is possible in the left-right direction. That is, it is a height for forming a state (ON state) in which the electrode films 45 and 46 can come into contact with each other when acceleration is input to the acceleration switch 1. The length of the protrusion 70 shown in FIG. 2 on the surface facing the weight 34 (the length in the left-right direction in FIG. 2) is the relative movement between the weight 34 and the protrusion 70 when acceleration is input. In order to reduce the influence of the frictional force at the time, it is preferable that the length is at least shorter than the length of the bottom surface of the weight portion 34 (the length in the left-right direction in FIG. 2).

  Further, for example, as shown in FIG. 3, the protruding portion 70 is provided at any location of the bottom portion of the weight portion 34 in a plan view. Here, FIG. 3A shows a case where the protrusion 70 is formed in a circular shape centering around the radial center of the arc in the bottom of the arc-shaped weight 34 in plan view. ) Suggests the case where the protrusion 70 is formed in a semicircular arc shape.

  In this case, the weight portion 34 sinks due to its own weight and is placed on the projection 70 and is supported at different height positions depending on the planar position, but the weight portion 34 at each planar position. Of these, the height of the protrusion 70 may be adjusted so that the bottom surface is at the predetermined height at the position closest to the first substrate 12.

  The second substrate 13 is made of the same material as that of the first substrate 12 and has a shape in plan view equivalent to that of the switch body 11, and seals the switch body 11 from below in the direction of gravity. Further, the second substrate 13 is bonded to the frame body 31 and the center electrode 32 of the switch body 11 via the second bonding film 42. As a result, in the acceleration switch 1, the central electrode 32 and the beam portion 35 are sealed in the inner space defined by the frame 31, the first substrate 12, and the second substrate 13. Further, in the main surface of the second substrate 13 on the side of the switch body 11, a portion other than the frame body 31 and the central electrode 32 is formed with a relief portion 57 (upper accommodation portion) that allows the weight portion 34 to be displaced. The

  Furthermore, in the portion of the second substrate 13 that is located above the central electrode 32 and the portion that is located above the frame 31, there are exposed holes 58 that penetrate the thickness direction and expose the second bonding film 42. It is formed. The second substrate 13 is formed with through electrodes 59 (for example, Al or the like) for electrically connecting the second bonding film 42 and the external device through the exposed holes 58. That is, in the second bonding film 42, the portions located above the central electrode 32 and the frame body 31 are used to connect the electrode films 45, 46 of the central electrode 32 and the weight part 34 and external devices. It also functions as a circuit.

[Acceleration switch manufacturing method]
Next, a method for manufacturing the acceleration switch 1 described above will be described. 4 and 5 are process diagrams for explaining a method of manufacturing the acceleration switch 1, and are cross-sectional views corresponding to FIG.
First, as shown in FIG. 4A, the first bonding film 41 is formed on the main surface on one end side in the thickness direction of the substrate 20 (first bonding film forming step). Specifically, the first bonding film 41 is left only on portions corresponding to the frame body 31 and the central electrode 32 on the main surface on one end side in the thickness direction of the substrate 20 using a lift-off method or the like.

  Next, as shown in FIG. 4B, dry etching such as DRIE (deep reactive ion etching) is performed from one end side in the thickness direction of the substrate 20 using a mask (not shown). A recess 60 having a predetermined depth is formed in a portion corresponding to a portion other than the frame 31, the center electrode 32, and the weight portion 34 (first etching step). Note that the depth (etching amount) of the recess 60 corresponds to the difference between the thickness of the substrate 20 and the thickness of the beam portion 35.

  Next, as shown in FIG. 4C, on the upper surface of the relief portion 56 of the first substrate 12, a protrusion 70 made of low melting point glass or the like using, for example, a mask sputtering method or a screen printing method is shown in FIG. It forms in the illustrated position (projection part formation process). Thereafter, as shown in FIG. 4D, the first substrate 12 is bonded to the frame body 31 and the center electrode 32 of the substrate 20 via the first bonding film 41 (first substrate bonding step). .

  Next, as shown in FIG. 5A, dry etching such as DRIE is performed from the other end side in the thickness direction of the substrate 20 using a mask (not shown). 32, portions other than the weight portion 34 and the beam portion 35 are removed (second etching step). Thereby, the recessed part 60 penetrates in the thickness direction, so that the beam part 35 is formed and the central electrode 32 and the weight part 34 are separated from each other via a gap.

Subsequently, as shown in FIG. 5B, the second bonding film 42 is formed over the entire main surface on the other end side in the thickness direction of the substrate 20 using sputtering or the like (metal film forming step). . The particles are deposited on the inner surface of the weight portion 34 and the outer surface of the central electrode 32 by the wraparound of the particles when forming the second bonding film 42, so that the outer surface of the weight portion 34 and the outer surface of the central electrode 32 are removed. Electrode films 45 and 46 are formed on the side surfaces.
After that, as shown in FIG. 5C, the second substrate 13 is bonded to the frame body 31 and the center electrode 32 of the substrate 20 via the second bonding film 42 (second substrate bonding step). .

Finally, as shown in FIG. 2, a metal film made of Al or the like is formed on the second substrate 13 and then patterned to form the through electrode 59 (through electrode forming step).
Thus, the acceleration switch 1 described above is completed.

"Accel switch operation"
Next, the operation of the acceleration switch 1 according to this embodiment will be described. Here, FIG. 6 is an operation explanatory view of the acceleration switch 1 and is a cross-sectional view corresponding to FIG.
In the acceleration switch 1 configured as described above, the weight 34 sinks downward by its own weight (gravity) from the initial state shown in FIG. 2, and is supported by the protrusion 70 as shown in FIG. At this time, for example, when acceleration in the left to right direction (hereinafter referred to as acceleration direction) in FIG. 6 is input to the acceleration switch 1, the entire acceleration switch 1 excluding the weight portion 34 moves in the acceleration direction. On the other hand, since the weight part 34 is supported by the frame body 31 via the beam part 35, it tries to stay in place by inertia. As a result, the frame 31 and the central electrode 32 and the weight portion 34 are relatively moved, and the beam portion 35 is elastically displaced along with the relative movement.

As a result, as shown in FIG. 6, when the electrode films 45 and 46 of the center electrode 32 and the weight portion 34 are in electrical contact with each other, the acceleration switch 1 is turned on. At this time, since the weight part 34 sinks downward due to its own weight, the thickness direction positions of the central electrode 32 and the weight part 34 are shifted from the initial state. 70, the electrode films 45 and 46 can be reliably in electrical contact with each other.
Then, the external device performs a predetermined operation by detecting the ON state of the acceleration switch 1 as a detection signal via the through electrode 59.

  As described above, according to the acceleration switch 1 according to the present embodiment, the protruding portion 70 is provided on the upper surface of the relief portion 56 of the first substrate 12 facing the bottom surface of the weight portion 34. When the weight 34 sinks due to its own weight, the protrusion 70 raises the weight 34 to a predetermined height (at least, the lower end of the electrode film 46 provided on the outer surface of the central electrode 32 and the overhanging portion. Since the upper end of the electrode film 45 provided on 36 is supported at a height higher than the height at which the electrode film 45 can be contacted in the left-right direction in FIG. 2, the electrode films 45 and 46 reliably make electrical contact. I can do it. Therefore, according to the acceleration switch 1 according to the present embodiment, the operation reliability as the acceleration switch can be improved.

Second Embodiment
Next, a second embodiment of the present invention will be described. Here, FIG. 7 is a cross-sectional view of the switch body 100 according to the second embodiment, and FIG. 8 is a plan view of the switch body 100 for explaining the positions where the protrusions are formed. In the following description, the same components as those in the first embodiment described above are denoted by the same reference numerals and description thereof is omitted.

  In the switch body 100 according to the first embodiment, the case where the protrusions 70 are provided only at the locations illustrated in FIG. 3 is illustrated, but in the switch body 100 according to the present embodiment, as illustrated in FIGS. Of the portions corresponding to the lower part of the weight 34, the protrusion 70 a is provided at a symmetrical position with the center electrode 32 as the center. Here, FIG. 8A shows a protrusion 70a having the same shape as the protrusion 70a formed at a position corresponding to the planar position shown in FIG. It is a figure which illustrates the formed state. On the other hand, FIG. 8B is a diagram suggesting a case where the protrusion 70a is formed in an arc shape in the vicinity of the center in the radial direction of the arc of the bottom of the arc-shaped weight portion 34. In this case, in the switch body 100 according to the first embodiment, as shown in FIG. 6, the height position of the weight part 34 varies locally in a state where the weight part 34 is supported by the protrusion part 70. However, in the switch main body 100 according to the present embodiment, the weight part 34 at a symmetrical position with respect to the center electrode 32 can be supported at a uniform height by the protrusion 70a.

  Therefore, according to the acceleration switch 1 according to the present embodiment, the same effect as that of the acceleration switch 1 according to the first embodiment can be obtained, and even if acceleration is input from any direction, the acceleration switch 1 can be more reliably obtained. Since electrical contact between the electrode films 45 and 46 can be realized, further improvement in operational reliability as an acceleration switch can be expected.

<Third Embodiment>
Next, a third embodiment of the present invention will be described. FIG. 9 is a cross-sectional view of the switch body 100 according to the third embodiment. In the following description, the same components as those in the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.
In the switch body 100 according to the present embodiment, as shown in FIG. 9, a conductive film 71 is formed on the upper surface of the protrusion 70a.

  The conductive film 71 is a conductive film made of a metal material such as Au, Cr, Ni, or Si, for example, and is formed so as to cover the upper surface of the protrusion 70a. The conductive film 71 alleviates the influence of electrostatic force generated between the weight part 34 and the protrusion part 70 when acceleration is input to the acceleration switch 1.

  That is, when acceleration is input to the acceleration switch 1 in the left-right direction in FIG. 9 with the weight portion 34 supported by the protrusion portion 70, the entire acceleration switch 1 other than the weight portion 34 including the protrusion portion 70. ) Moves in the acceleration direction, an electrostatic force is generated by friction between the protrusion 70 and the weight 34, and there is a possibility that both of them attract each other slightly. In this case, it may be considered that the electrode film 46 of the central electrode 32 connected to the protrusion 70 does not sufficiently contact the electrode film 45 of the weight 34. However, in the switch main body 100 according to the present embodiment, the influence of the electrostatic force is alleviated by the conductive film 71 provided on the upper surface of the protrusion 70a, so that the central electrode 32 is reliably moved in the acceleration direction, and the electrode film The contact between the electrode 46 and the electrode film 45 can be made more reliable.

  Therefore, according to the acceleration switch 1 according to the present embodiment, the same effect as that of the acceleration switch 1 according to the above-described embodiment can be obtained, and the weight portion 34 and the protruding portion when the acceleration is input to the acceleration switch 1. The influence of the electrostatic force generated between the electrode films 45 and 70 can be mitigated, the electrical contact between the electrode films 45 and 46 can be realized more reliably, and further improvement of the operation reliability as an acceleration switch can be expected.

<Fourth embodiment>
Next, a fourth embodiment of the present invention will be described. FIG. 10 is a cross-sectional view of the switch body 100 in the fourth embodiment. In the following description, the same components as those in the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.
In the switch main body 100 according to the present embodiment, as shown in FIG. 10, a solid lubricant film 72 is formed on the upper surface of the protrusion 70a.

  The solid lubricating film 72 is a film made of a material having solid lubricating properties such as Teflon (registered trademark), molybdenum disulfide, and the like, and is formed so as to cover the upper surface of the protruding portion 70a. The solid lubricating film 72 alleviates the influence of the frictional force generated between the weight 34 and the protrusion 70 when acceleration is input to the acceleration switch 1. The solid lubricating film 72 may be a film made of a material having both conductivity and solid lubricating properties, such as copper and graphite.

  That is, when acceleration is input to the acceleration switch 1 in the left-right direction in FIG. 9 with the weight portion 34 supported by the protrusion portion 70, the entire acceleration switch 1 other than the weight portion 34 including the protrusion portion 70. ) Moves in the acceleration direction, a frictional force acts between the protrusion 70 and the weight 34, and therefore the movement of the protrusion 70 in the acceleration direction may be slightly inhibited. In this case, it may be considered that the electrode film 46 of the central electrode 32 connected to the protrusion 70 does not sufficiently contact the electrode film 45 of the weight 34. However, in the switch body 100 according to the present embodiment, the friction coefficient between the projection 70 and the weight 34 can be lowered by the solid lubricant film 72 provided on the upper surface of the projection 70a. By reliably moving in the acceleration direction, the contact between the electrode film 46 and the electrode film 45 can be made more reliable. Further, as described above, since the solid lubricating film 72 can be a film made of a material having both conductivity and solid lubricating property, as described in the third embodiment, the influence of electrostatic force is simultaneously reduced. be able to.

  Therefore, according to the acceleration switch 1 according to the present embodiment, the same effect as that of the acceleration switch 1 according to the above-described embodiment can be obtained, and the weight portion 34 and the protruding portion when the acceleration is input to the acceleration switch 1. The influence of the frictional force generated between the electrode films 45 and 70 can be mitigated, the electrical contact between the electrode films 45 and 46 can be realized more reliably, and further improvement in operation reliability as an acceleration switch can be expected.

<Fifth Embodiment>
Next, a fifth embodiment of the present invention will be described. FIG. 11 is a cross-sectional view of the switch body 100 according to the fifth embodiment. In the following description, the same components as those in the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.
In the switch main body 100 according to the present embodiment, as shown in FIG. 11, the protruding portion 80 (upper protruding portion) is also formed in the escape portion 57 (upper accommodating portion) of the second substrate 13.

  The protrusion 80 is formed on the lower surface of the escape portion 57 (the surface facing the weight portion 34), and is made of the same material and shape as the protrusion 70a. Here, as described above, the acceleration switch 1 may have an aspect in which the vertical direction in FIG. That is, when used in the opposite direction, the weight portion 34 sinks toward the escape portion 57 due to its own weight. In this case, the weight portion 34 is provided at a predetermined height (at least at the upper end of the electrode film 46 provided on the outer surface of the central electrode 32 and the overhang portion 36 by a protrusion 80 provided on the escape portion 57. Since the lower end of the electrode film 45 is supported at a height higher than the height at which the electrode film 45 can be contacted in the left-right direction in FIG. 11, the electrode films 45 and 46 can reliably make electrical contact.

  Therefore, according to the acceleration switch 1 according to the present embodiment, the same effect as the acceleration switch 1 according to the above-described embodiment can be obtained, and even if the acceleration switch 1 is used in the upside down direction, Further, electrical contact between the electrode films 45 and 46 can be realized, and further improvement in operation reliability as an acceleration switch can be expected.

<Modification>
The switch body 100 according to the fifth embodiment has a conductive film 81 formed on the lower surface as shown in FIG. 12 with respect to the protrusion 80 of the second substrate 13, or a solid surface on the lower surface as shown in FIG. It may be formed with the lubricating film 82 formed.

  Here, the conductive film 81 shown in FIG. 12 is made of, for example, the same material as the conductive film 71 shown in FIG. 9, and the weight 34 and the protrusion 80 when the acceleration is input to the acceleration switch 1. Alleviate the influence of electrostatic force generated between them. 13 is made of the same material as that of the solid lubricant film 72 shown in FIG. 10, for example, and the gap between the weight part 34 and the protrusion part 80 when acceleration is input to the acceleration switch 1 is used. To reduce the effects of frictional force and electrostatic force.

Therefore, according to the acceleration switch 1 according to this modification, even when the acceleration switch 1 is used upside down, the acceleration switch 1 is influenced by the electrostatic force and the frictional force generated between the weight part 34 and the protrusion part 80. Therefore, it is possible to reliably realize electrical contact between the electrode films 45 and 46 and to further improve the operation reliability as an acceleration switch.
Note that the present invention is not limited to the above-described embodiments described with reference to the drawings, and various modifications are conceivable within the technical scope thereof.

  For example, in the above-described embodiment, the shape of the protrusions 70, 70a, and 80 is a trapezoidal shape in a longitudinal sectional view. However, the shape can be appropriately changed as long as the shape can support the weight portion 34, such as a triangular shape or a quadrangular shape. It is. Moreover, although low melting glass was illustrated as a material of the projections 70, 70a, 80, it may be formed of the same material as the first substrate 12 and the second substrate 13 (for example, a glass material such as borosilicate glass). good. In this case, when the relief portions 56 and 57 are formed on the first substrate 12 and the second substrate 13, the relief portions 56 and 57 are also formed integrally with the projections 70, 70 a, and 80 so that the manufacturing process can be performed. It can be simplified. Further, the protrusions 70, 70 a, 80 are formed at the same plane position as the weight part 34 in the escape parts 56, 57, but may be formed at the same plane position as the beam part 35. In this case, the beam part 35 connected to the weight part 34 can be prevented from sinking due to its own weight, so that more reliable electrical contact between the electrode films 45 and 46 can be expected.

  Furthermore, the protrusions 70, 70a, 80 may have a spring-like structure, and the weight 34 may be pushed up by the reaction force of the spring in a state where the protrusions 70, 70a, 80 are in contact with the weight 34 by their own weight. Further, as shown in FIG. 14, solid lubricant films 90 and 91 may be formed on the entire surface of the weight portion 34 that faces the protrusions 70, 70 a, and 80.

  In the above-described embodiment, the configuration in which the beam portion 35 has an arc shape has been described. However, the present invention is not limited to this, and a design change such as a rectangular shape can be made as appropriate. Accordingly, the design of the central electrode 32 and the weight portion 34 in plan view can be changed as appropriate, such as a rectangular shape. In other words, the beam portion 35 only needs to surround the weight portion 34. The design of the length of the beam portion 35 in the circumferential direction can be changed as appropriate.

Furthermore, although the case where the electronic device of this invention was applied to the acceleration switch 1 was demonstrated in embodiment mentioned above, this invention may be applied not only to this but an acceleration sensor etc.
In addition, in the range which does not deviate from the meaning of this invention, it is possible to replace suitably the component in the embodiment mentioned above by a known component, and you may combine each modification mentioned above suitably.

DESCRIPTION OF SYMBOLS 1 ... Acceleration switch 11 ... Switch main body 12 ... 1st board | substrate 13 ... 2nd board | substrate 31 ... Frame body 32 ... Central electrode 33 ... Accommodating hole 34 ... Weight part 35 ... Beam part 36 ... Overhang | projection part 41 ... 1st junction film 42 ... second bonding film 45,46 ... electrode film 56,57 ... escape portion 58 ... exposed hole 59 ... through electrode 70,70a, 80 ... projection part 71,81 ... conductive film 72,82,90,91 ... solid lubrication Membrane 100 ... Acceleration switch 131 ... Frame body 132 ... Central electrode 133 ... Accommodating hole 134 ... Weight portion 135 ... Beam portion 136 ... Overhang portion 145, 146 ... Electrode film 156, 157 ... Escape portion

Claims (7)

A central electrode;
The center electrode is housed inside, and the weight is made elastic between the weight part whose inner side surface can be contacted and separated from the outer side surface of the center electrode and the weight part. A structural substrate having a beam portion to support;
Sealing the structure substrate from below in the direction of gravity, and a lower sealing substrate including a lower housing portion that houses the weight portion in a state of being separated in the gravity direction;
A lower projecting portion projecting toward the lower end surface on at least a part of a surface of the lower housing portion facing the lower end surface in the gravity direction of the weight portion;
An electronic device comprising:   The electronic device according to claim 1, wherein the lower protrusion is formed at a position symmetrical with respect to the central electrode in a plan view.   The electronic device according to claim 1, wherein the lower protrusion is made of a material having at least one of conductivity and solid lubricity.   2. The lower projecting portion, wherein a surface of the weight portion facing the lower end surface in the gravitational direction is covered with a film having at least one of conductivity and solid lubricity. The electronic device according to claim 2. Sealing the structure substrate from above in the gravitational direction, and an upper sealing substrate having an upper accommodating portion for accommodating the weight portion in a state of being separated in the gravitational direction;
An upper projecting portion projecting toward the upper end surface on at least a part of a surface of the upper housing portion facing the upper end surface in the gravity direction of the weight portion,
The electronic device according to claim 1, further comprising:   6. The electronic device according to claim 5, wherein the upper protruding portion is made of a material having at least one of conductivity and solid lubricity.   6. The upper projecting portion according to claim 5, wherein a surface of the weight portion facing the upper end surface in the gravitational direction is covered with a film having at least one property of conductivity and solid lubricity. Electronic devices.