CN101789329A - Three-dimensional multidirectional-sensitive micromechanical inertial electrical switch - Google Patents

Abstract

A three-dimensional and multi-directional sensitive micro-mechanical inertial electrical switch in the technical field of micro-electro-mechanical systems, including: mass block electrodes, cantilever beam horizontal fixed electrodes, spiral horizontal fixed electrodes, cantilever beam vertical fixed electrodes, several groups of serpentine springs, insulating The substrate, the spiral fixed electrode support seat, the spring support seat, the vertical fixed electrode support seat and the cantilever beam support seat, wherein: the electrodes of the mass block are respectively connected to one end of the four sets of serpentine springs, and the other end of the serpentine spring is connected to the spring support seat connected and suspended between the insulating substrate and the vertical fixed electrode of the cantilever beam, the spring support seat and the cantilever beam support seat are respectively fixed on the insulating substrate and located around the mass block electrode, and the spiral horizontal fixed electrode and the spiral fixed electrode supporting seat are fixedly arranged on the substrate in sequence. The present invention makes a micromachined inertial electrical switch responsive to acceleration shocks from multiple directions, both horizontal and vertical.

Description

Three-dimensional multi-directional sensitive micromachined inertial electrical switch

technical field

The invention relates to a device in the technical field of micro-electro-mechanical systems, in particular to a three-dimensional multi-directional sensitive micro-mechanical inertial electrical switch.

Background technique

Inertial switches designed and manufactured based on MEMS technology have attracted much attention because of their advantages of small size, low cost and mass production. In the past, the micro-mechanical inertia switch, because its processing method was based on micro-electro-mechanical system technology, in many cases, the switch was prepared by etching or electroplating on the basis of silicon. Suspended horizontally movable structure, and using the etched side wall slope to realize the switching function of the inertial switch, which is a horizontally driven micromechanical inertial switch; and through the electroplating and sacrificial layer process technology on the single crystal silicon substrate , the vertically driven micromechanical inertial switch can be realized, but due to the unavoidable internal stress in the electroplating process, this determines that the height of the entire device cannot be too thick. In order to have a large enough mass to sense the external acceleration, This ultimately results in a larger overall area of the device.

Most of the micromechanical inertial electrical switches are designed in the form of a cantilever beam or a spring connected to a mass block electrode to contact and collide with another fixed electrode. The manufactured switching device is either horizontally driven or only vertically driven. When it is necessary to detect both horizontal and vertical directions When the acceleration is applied, the inertial electrical switches of these two different driving modes can only be used in combination, which not only causes a waste of the number of switching devices, but also makes the packaging and integration of the system more difficult and complicated. Therefore, how to sense and detect acceleration shocks from multiple directions with as few inertial switching devices as possible, and how to integrate sensitive three-dimensional multi-directional accelerations into a micro-switching device has always been the direction of people's efforts. As a result, various The design of micro-mechanical inertial electrical switches that improve the above-mentioned shortcomings has been continuously proposed.

Found through literature search to the prior art, Wei Ma et al published a paper titled "Fabrication and packaging of inertia micro-switch" in "Sensors and Actuators A" ("Sensors and Actuators A", No. Using low-temperature photo-resist molded metal-electroplatingtechnology" ("Using low-temperature metal plating technology to manufacture and package the inertial micro-electrical switch"), it is proposed to use the silicon substrate as the basis and the method of electroplating metal on it to realize the micro-electroplating technology. Preparation of mechanical inertial switch, the micro inertial switch uses a mass block connected with a cantilever beam as one of the electrodes, and the other electrode is located on the substrate below the mass block, or on the same plane as the mass block, so as to realize the vertical direction drive, or drive in the horizontal direction. For horizontally driven inertial electrical switches, since the mass block cannot be plated too thick on the silicon substrate, the mass block needs to occupy a large area to generate a large enough inertial driving force to trigger the switch, and the inertial switch has no obvious three-dimensional structure; For the vertically driven inertial switch, when the electrode of the mass block collides with another electrode directly on the substrate, the rigidity of both is very large, so that the contact effect is poor and the time is short, coupled with the mass of high-speed rebound The block does not have any boundary guards and may cause damage to the device. More importantly, none of the switching devices proposed in the paper can be used independently to simultaneously detect acceleration shocks in multiple directions.

Contents of the invention

The present invention aims at the above-mentioned deficiencies in the prior art, and provides a three-dimensional and multi-directional sensitive micro-mechanical inertial electrical switch, so that the entire micro-mechanical inertial electrical switch can be sensitive to acceleration impacts from multiple horizontal and vertical directions at the same time, and enables The movable mass electrode and the fixed electrode have a good contact effect, and the movement of the mass electrode is limited between the insulating substrate and the fixed electrode, which plays a certain role in protecting the device from accidental overload impact.

The present invention is realized through the following technical solutions, the present invention includes: mass electrode, cantilever beam horizontal fixed electrode, spiral horizontal fixed electrode, cantilever beam vertical fixed electrode, several groups of serpentine springs, insulating substrate, spiral fixed electrode support Seat, spring support seat, vertical fixed electrode support seat and cantilever beam support seat, wherein: the electrodes of the mass block are respectively connected with one end of the four sets of serpentine springs, and the other ends of the serpentine springs are connected with the spring support seat and the electrodes of the mass block are connected to each other. Suspended between the insulating substrate and the vertical fixed electrode of the cantilever beam, the spring support seat and the cantilever beam support seat are respectively fixed on the insulating substrate and located around the electrode of the mass block, and the spiral horizontal fixed electrode and the spiral fixed electrode support seat are in turn fixed on the substrate.

The mass electrode is a ring structure formed by stacked metal plating, with an outer diameter of 1000-2000 microns, an inner diameter of 200-1200 microns, a height of 50-500 microns, and four protruding semicircles with an inner radius of 400-1000 microns .

The horizontal fixed electrode of the cantilever beam is a cantilever structure formed by one or more layers of metal plating, with a width of 50-200 microns, a length of 100-400 microns, a thickness of 50-500 microns, and an oblique section angle of 30-60° , the horizontal fixed electrode of the cantilever beam adopts a suspended structure, which can effectively reduce its structural rigidity, and cooperate with the corresponding oblique section contact, which can well improve the contact effect between the two electrodes.

The spiral horizontal fixed electrode is a spiral structure formed by metal plating with more than three turns, its root width is 50-200 microns, its thickness is 50-500 microns, its spiral radius is 100-500 microns, and its spiral angle is 60-120°.

The vertical fixed electrode of the cantilever beam is a circular structure or fan-shaped structure formed by metal plating, and the radius of the circular structure is 150 to 650 microns; the fan-shaped structure is three blades or multiple blades, Wherein: the angle between the three blades is 120°, the root width is 50-200 microns, the thickness is 10-50 microns, and the end radius is 10-50 microns.

The serpentine spring is a one-turn or multi-turn structure formed by metal plating, its line width is 5-50 microns, its thickness is 4-50 microns, the inner diameter of the semicircle is 20-100 microns, and the vertical length connecting the semi-circles is The diameter is 50-500 microns. After the serpentine spring is subjected to external acceleration, the movement of the suspended serpentine spring and the electrode of the mass block can maintain consistency and coordination, which is conducive to stable and reliable contact.

The insulating substrate can be made of insulating materials such as quartz and glass.

The spiral fixed electrode support seat is a square or circular columnar structure formed by electroplating metals such as nickel or copper.

The spring support seat is a square or ring-shaped columnar structure formed by electroplating nickel or copper and other metals.

The vertical fixed electrode support seat is a square or circular columnar structure formed by electroplating metal such as nickel or copper.

The cantilever beam supporting seat is a square or ring columnar structure formed by electroplating nickel or copper and other metals.

When a sufficiently large negative acceleration acts on the three-dimensional multi-directional sensitive micromechanical inertial electrical switch of the present invention along the normal direction of the upper surface of the insulating substrate, or a sufficiently large positive acceleration acts on the above electrical switch along the normal direction of the lower surface of the insulating substrate. When switching, the electrode of the mass block will touch the vertical fixed electrode of the cantilever beam, so as to realize the connection of the external circuit in the vertical direction; when the external acceleration is large enough to act on the above electrical switch along any direction parallel to the upper surface of the insulating substrate , the mass electrode will contact the cantilever beam horizontal fixed electrode or the spiral horizontal fixed electrode, so as to realize the connection of external circuits in multiple horizontal directions.

The invention is based on micro-electro-mechanical system processing technology, and is produced by laminating and electroplating the entire switch structure multiple times without interfering with each other on insulating substrates such as quartz or glass at room temperature. Under the action of external acceleration, the present invention relies on the inertial force to drive the suspended mass electrode of the serpentine spring to move, so as to touch the horizontal fixed electrode of the cantilever beam, the spiral horizontal fixed electrode or the vertical fixed electrode of the cantilever beam with a certain distance from it, and then Under the force of the spring, the electrode of the mass block is quickly pulled back, and finally the instant switch of the circuit is realized.

In view of the fact that the previous micromechanical inertial electrical switches only had a single horizontal drive or vertical drive, the switches of these two different drive modes can only be used in combination to detect the acceleration from the horizontal and vertical directions at the same time, resulting in a large number of switching devices. In order to solve the problems of waste and other issues on the Internet, a three-dimensional multi-directional sensitive micro-mechanical inertial electrical switch with a snake-shaped spring, a helical horizontal fixed electrode and a cantilever beam vertical fixed electrode is proposed. Only one micro-switch device can simultaneously detect from The multi-directional acceleration impact effect not only improves the contact effect between electrodes, but also facilitates the system packaging during its use.

Description of drawings

Fig. 1 is a schematic structural diagram of a three-dimensional multi-directional sensitive micro-mechanical inertial electrical switch with blade-shaped cantilever beam vertically fixed electrodes in embodiment 1

Fig. 2 is a schematic diagram of the mass electrode structure of embodiment 1

Fig. 3 is a schematic diagram of the vertical fixed electrode structure of the blade-shaped cantilever beam with wind in Embodiment 1

Fig. 4 is a structural schematic diagram of the spiral horizontal fixed electrode and the cantilever beam horizontal fixed electrode of embodiment 1

Fig. 5 is a schematic structural diagram of a three-dimensional multi-directional sensitive micro-mechanical inertial electrical switch with a layer of cantilever beam horizontally fixed electrodes in embodiment 2

Fig. 6 is a schematic structural diagram of a three-dimensional multi-directional sensitive micromechanical inertial electrical switch with circular porous vertical fixed electrodes in embodiment 3

Detailed ways

The embodiments of the present invention are described in detail below. This embodiment is implemented on the premise of the technical solution of the present invention, and detailed implementation methods and specific operating procedures are provided, but the protection scope of the present invention is not limited to the following implementation example.

Example 1

As shown in Figure 1, this embodiment includes: mass electrode 1, cantilever beam vertical fixed electrode 2, cantilever beam horizontal fixed electrode 3, spiral horizontal fixed electrode 4, serpentine spring 5, insulating substrate 6, spring support seat 7. Cantilever beam support base 8, spiral fixed electrode support base 9 and vertical fixed electrode support base 10, wherein: mass electrode 1 is connected to one end of four groups of serpentine springs 5 respectively, and the other end of four groups of serpentine springs 5 is connected to The spring support base 7 is connected and the mass electrode 1 is suspended above the insulating substrate 6 and 10 to 50 microns below the cantilever vertical fixed electrode 2, and the spring support base 7 and the cantilever beam support base 8 are respectively fixed on the insulating substrate 6 and located around the mass block electrode 1, the distance between the cantilever beam support base 8 and the mass block electrode 1 is 10-50 microns, the spiral horizontal fixed electrode 4 is located at the center of the mass block 1, and is fixed by the spiral electrode support base 9 is fixed on the substrate 6, and there is a gap of 10-50 microns between it and the mass electrode 1.

The mass electrode 1 is ring-shaped, and its size is: the outer radius is 1500 microns long, the inner radius is 500 microns, and the height is 100 microns, and the inner radius of the four protruding semicircles is 400 microns. Copper and other metal production;

The included angle between the three blades of the blade-shaped cantilever vertically fixed electrode 2 is 120°, the root width is 150 microns, the thickness is 30 microns, and the end radius is 20 microns;

The cantilever beam horizontal fixed electrode 3 has a length of 300 microns, a width of 100 microns, a thickness of 50 microns, and an oblique section angle of 60°;

The root width of the spiral horizontal fixed electrode 4 is 150 microns, the thickness is 100 microns, the helix radius is 100 microns, and the helix angle is 120°;

The serpentine spring 5 has a line width of 10 microns, a thickness of 20 microns, an inner diameter of 20 microns and an outer diameter of 40 microns at the semicircle;

The size of the insulating substrate 6 is 2000 microns in radius and 50-100 microns in height;

The spring support seat 7 is an annular fan-shaped structure with an outer radius of 2000 microns, an inner radius of 1800 microns, a height of 100 microns, and a sector angle of 30°;

The fixed electrode support seat 8 of the horizontal cantilever beam is an annular fan-shaped structure with an outer radius of 2000 microns, an inner radius of 1800 microns, a height of 100 microns, and a sector angle of 30°;

The spiral fixed electrode support seat 9 is a circular columnar structure, the inner radius of its section is 200 microns, and the height is 15 microns;

The vertical cantilever beam fixed electrode support base 10 is a circular columnar structure with a section inner radius of 200 microns and a height of 20 microns.

As shown in FIG. 2 , it is a schematic diagram of the three-dimensional structure of the mass electrode 1 with the blade-shaped cantilever beam vertical fixed electrode 2 in this embodiment, and the spring support seat 7 and the horizontal cantilever beam fixed electrode support seat 8 located around the mass block electrode 1 Plating on the insulating substrate 6, the serpentine spring 5, the mass block electrode 1 connected thereto and the cantilever beam horizontal fixed electrode 3 are suspended.

As shown in FIG. 3 , it is a structural schematic diagram of a vane-shaped baffle beam used as a vertical cantilever beam fixed electrode 2 in this embodiment. The spiral fixed electrode support base 9 is electroplated on the insulating substrate 6, and the spiral fixed electrode 4 is suspended in the air. The vertical cantilever beam fixed electrode support seat 10 connected above it suspends the vane-shaped baffle beam, and the formed layered structure is connected with the insulating substrate 6 as a whole, and is located in the center of the insulating substrate 6 and the center of the annular mass 1 .

As shown in Figure 4, it is a schematic structural view of the spiral horizontal fixed electrode 4 of this embodiment. It can be seen from the figure that the spiral horizontal fixed electrode 4 is composed of three helical blades, and it is suspended on the insulating lining by the spiral fixed electrode support seat 9. There is a certain distance between the center of the bottom 6 and the three groups of cantilever beam horizontal fixed electrodes 3 located on the periphery of the insulating substrate 6 .

Connect the two poles of the external circuit to the mass electrode 1 and the vertical cantilever beam fixed electrode 2 or the cantilever beam horizontal fixed electrode 3 (or the spiral horizontal fixed electrode level 4) of the above-mentioned three-dimensional multi-directional sensitive micromechanical inertial electrical switch, respectively. After receiving a sufficiently large acceleration from the outside on the sensitive axis direction of the switch (here, the normal direction of the surface of the insulating substrate 6 or the direction parallel to the surface of the insulating substrate 6), driven by the inertial force of the mass block, the snake The mass electrode 1 suspended by the shaped spring 5 moves to and touches the fixed electrode 2 of the vertical cantilever beam, or the horizontal fixed electrode 3 of the cantilever beam, or the horizontal fixed electrode level 4 of the spiral type, and is then pulled apart by the serpentine spring 5, thereby realizing The rapid on-off of the external circuit, the structure of the vertical cantilever fixed electrode 2, the spiral fixed electrode 4 and the structure of the cantilever horizontal fixed electrode 3 all reduce their respective rigidities, and the rapid collision of the mass electrode 1 driven by inertial force Played a certain mitigation effect, enhanced the switch contact effect. Simultaneously, the present invention can be sensitive to acceleration shocks from horizontal and vertical multiple directions by only using one inertial switch, and realizes the advantages of integrating three-dimensional and multiple-directional accelerations sensitive to a micro-switch device.

Example 2

As shown in Figure 5, the horizontal fixed electrode 3 of the cantilever beam with a single-layer structure is arranged on the periphery of the mass electrode 1 in this embodiment, and the size of the micromechanical inertial electrical switch is perpendicular to that of the cantilever beam with fan blade shape in Embodiment 1. The three-dimensional and multi-directional sensitive micromechanical inertial electrical switch of the fixed electrode is the same, and except for the fixed electrode of the horizontal cantilever beam, the shape and size of the other components are the same as those in Embodiment 1.

Example 3

As shown in Figure 6, in this embodiment, a cantilever beam with a cylindrical plane with holes is used to fix the electrode 2 vertically. The holes 11 have a radius of 10-50 microns and are evenly distributed on the cylinder with a distribution interval of 50-100 microns. The rest of the features of the micromechanical inertial electrical switch are similar to those of Embodiment 1.

Claims (9)

1. the micro-mechanical inertia electrical switch of a three-dimensional multidirectional-sensitive, comprise: the mass electrode, cantilever beam horizontal fixed electrode, spiral type horizontal fixed electrode, cantilever beam vertical fixing electrode, some groups of serpentine springs, dielectric substrate, screw fixed electrode supporting seat, the spring supporting seat, vertical fixing electrode supporting seat and cantilever beam supporting seat, it is characterized in that: the mass electrode links to each other with an end of four groups of serpentine springs respectively, the other end of serpentine spring is connected with the spring supporting seat and the mass electrode is suspended between dielectric substrate and the cantilever beam vertical fixing electrode, spring supporting seat and cantilever beam supporting seat be fixedly set on the dielectric substrate respectively and be positioned at the mass electrode around, spiral type horizontal fixed electrode and screw fixed electrode supporting seat are fixedly set on the substrate successively.

2. the micro-mechanical inertia electrical switch of three-dimensional multidirectional-sensitive according to claim 1, it is characterized in that, described mass electrode is that lamination metal is electroplated the ring structure that forms, 1000 ~ 2000 microns of its external diameters, 200 ~ 1200 microns of internal diameters, high 50 ~ 500 microns, four outstanding semicircle inside radius of periphery are 400 ~ 1000 microns.

3. the micro-mechanical inertia electrical switch of three-dimensional multidirectional-sensitive according to claim 1, it is characterized in that, the cantilever design that described cantilever beam horizontal fixed electrode forms for one or more layers metal plating, its width is 50 ~ 200 microns, length is 100 ~ 400 microns, 50 ~ 500 microns of thickness, oblique section angle are 30 ~ 60 °.

4. the micro-mechanical inertia electrical switch of three-dimensional multidirectional-sensitive according to claim 1, it is characterized in that, described spiral type horizontal fixed electrode is the helical structure that the above metal plating of three circles forms, its root width is 50 ~ 200 microns, 50 ~ 500 microns of thickness, the radius of spin is 100 ~ 500 microns, 60 ~ 120 ° of helical angles.

5. the micro-mechanical inertia electrical switch of three-dimensional multidirectional-sensitive according to claim 1 is characterized in that, described cantilever beam vertical fixing electrode is circular configuration or the fan blade shape structure that metal plating forms.

6. the micro-mechanical inertia electrical switch of three-dimensional multidirectional-sensitive according to claim 5 is characterized in that, the radius of described circular configuration is 150 ~ 650 microns.

7. the micro-mechanical inertia electrical switch of three-dimensional multidirectional-sensitive according to claim 5, it is characterized in that, described fan blade shape structure is three fan blades or windy leaf, wherein: the angle between three fan blades is 120 °, the root width is 50 ~ 200 microns, 10 ~ 50 microns of thickness, end radius are 10 ~ 50 microns.

8. the micro-mechanical inertia electrical switch of three-dimensional multidirectional-sensitive according to claim 1, it is characterized in that, described serpentine spring is a circle or the multi-turn structure that metal plating forms, its live width is 5 ~ 50 microns, thickness is 4 ~ 50 microns, the internal diameter of semicircle is 20 ~ 100 microns, and the vertical length that connects between semicircle is 50 ~ 500 microns.

9. the micro-mechanical inertia electrical switch of 1 described three-dimensional multidirectional-sensitive as requested is characterized in that, is spaced apart 10 ~ 50 microns between described cantilever beam supporting seat and the mass electrode.

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