CN107742598A - A kind of electrothermal drive bistable state mems switch - Google Patents

Abstract

An electrothermally driven bistable MEMS switch, comprising a square base on which V-shaped electrothermal actuators I and V-shaped electrothermal actuators II are vertically distributed, and the V-shaped electrothermal actuator I drives the first hook under the control of a drive circuit Type contact, V-type electrothermal actuator II drives the second hook-type contact under the control of another drive circuit, the first hook-type contact and the second hook-type contact contact to conduct the circuit, the first hook-type contact The circuit is disconnected without contact with the second hook contact. The two drive circuits are pulse voltage and have a phase difference; using the thermoelectric effect and thermal expansion effect of the V-shaped beam, the hook is driven by applying voltage to cause thermal deformation. Contact movement; the invention has the advantages of high stability, large driving force, linear output, low power consumption and low cost.

Description

An Electrothermally Driven Bistable MEMS Switch

technical field

The invention relates to the technical field of MEMS switches, in particular to an electrothermally driven bistable MEMS switch.

Background technique

MEMS switch is one of the typical applications of MEMS technology. It is the result of the miniaturization design and manufacture of traditional electromechanical switches, which provides a strong guarantee for the development of high-performance circuit systems. There are extensive and urgent application requirements in circuit control. The bistable switch only needs external energy when the state is changed, and the state is maintained through the self-locking function of the structure. With the enhancement of system integration, low power consumption has become an important indicator for judging the excellent performance of the system. Steady-state MEMS switches are developing rapidly due to their excellent performance.

The existing electrothermally driven bistable MEMS switch has a bimetallic film structure, a cold and hot arm structure, etc., but it does not consider the influence of contact resistance and switch stability and holding force on the switch performance, and has small driving force, nonlinear output, and low response. Disadvantages of long time and difficult processing.

Contents of the invention

In order to overcome the above-mentioned shortcomings of the prior art, the object of the present invention is to provide an electrothermally driven bistable MEMS switch, which has the advantages of high stability, large driving force, linear output, low power consumption, and low cost.

In order to achieve the above object, the technical scheme adopted in the present invention is:

An electrothermally driven bistable MEMS switch, comprising a square base 11, on which a V-shaped electrothermal actuator I and a V-shaped electrothermal actuator II are vertically distributed, and the V-shaped electrothermal actuator I is driven under the control of a drive circuit U1 The first hook contact 6, the V-shaped electrothermal actuator II drives the second hook contact 10 under the control of another drive circuit U2, and the first hook contact 6 and the second hook contact 10 are in contact with each other to conduct In the circuit, the first hook contact 6 and the second hook contact 10 are disconnected without contact, the driving circuit U1 and the driving circuit U2 are pulse voltages, and the driving circuit U1 and the driving circuit U2 have a phase difference.

The V-shaped thermoelectric actuator 1 includes three equally spaced first V-shaped beams 2-1, second V-shaped beams 2-2, and third V-shaped beams 2-3. Both ends of the first V-shaped beam 2-1, the second V-shaped beam 2-2, and the third V-shaped beam 2-3 are connected to the first electrode anchor point 1-1 and the second electrode anchor point 1-2, and the first V-shaped beam 2-2 is connected to the second electrode anchor point 1-2. The middle of a V-shaped beam 2-1, the second V-shaped beam 2-2, and the third V-shaped beam 2-3 are connected through a vertical beam 3, and the upper end of the vertical beam 3 is connected with the lower end of the s-shaped wire 8, and the s The upper end of the type wire 8 is connected with the wire electrode 9; the lower end of the vertical beam 3 is connected with the upper end of the first flexible beam 4-1, and the lower end of the first flexible beam 4-1 is vertically connected with the front end of the lever 5, and the front end of the lever 5 It is vertically connected to the lower end of the second flexible beam 4-2, the upper end of the second flexible beam 4-2 is connected to the anchor point 7, and the end of the lever 5 is connected to the first hook contact 6.

The difference between the V-type thermoelectric actuator II and the V-type thermoelectric actuator I is: the first flexible beam 4-1 of the V-type thermoelectric actuator II is connected to the anchor point 7, and the second flexible beam 4-2 is connected to the anchor point 7. The vertical beam 3 is connected, the end of the lever 5 is connected with the second hook contact 10, and the rest of the composition and connection methods are the same as those of the V-type thermoelectric actuator 1.

The first electrode anchor point 1-1, the second electrode anchor point 1-2, the anchor point 7, and the wire electrode 9 are all fixed on the square base 11, and the rest of the structures are floating and movable structures.

The first V-shaped beam 2-1, the second V-shaped beam 2-2, the third V-shaped beam 2-3, the vertical beam 3, the first flexible beam 4-1, and the second flexible beam 4-2 , the lever 5, the first hook-shaped contact 6, the s-shaped wire 8, and the second hook-shaped contact 10 are all made of silicon materials.

The first hook-shaped contact 6 and the second hook-shaped contact 10 cooperate to have a self-locking function.

The electrothermally driven bistable MEMS switch is prepared using MEMS technology.

The distance between the first V-shaped beam 2-1, the second V-shaped beam 2-2, and the third V-shaped beam 2-3 is 100um-110um, the length is 1060um-1070um, the width is 36um-39um, and the included angle with the horizontal direction 9°-10°.

The first flexible beam 4-1 and the second flexible beam 4-2 are 290um-300um in length, 10um-12um in width, and the magnification of the lever 5 is 19-21.

Compared with traditional mechanical switches, the advantages of the present invention are:

The first hook-shaped contact 6 and the second hook-shaped contact 10 have self-locking function, simple structure, large contact force, and can maintain the closed state stably; simple adjustment of the hook-shaped contact can meet various layout methods, Strong portability and high flexibility.

The drive circuit of the V-type thermoelectric actuator is a pulse voltage. When the switch state changes, it does not need external energy supply for a long time, which greatly reduces system power consumption, reduces redundant hold signals, and improves the safety of the device.

The principle of thermoelectric actuator is applied to MEMS switch to obtain large driving displacement, short response time of the switch and easy processing.

Description of drawings

Fig. 1 is a structural schematic diagram of the present invention.

FIG. 2 is a schematic diagram of the movement process of the first hook-shaped contact 6 and the second hook-shaped contact 10 of the present invention.

FIG. 3 is a phase relationship diagram of the driving circuit U1 and the driving circuit U2 of the present invention.

detailed description

The present invention will be further described below in conjunction with the accompanying drawings.

Referring to Fig. 1, an electrothermally driven bistable MEMS switch includes a square base 11 on which a V-type electrothermal actuator I and a V-type electrothermal actuator II are vertically distributed, and the V-type electrothermal actuator I drives a circuit together The first hook contact 6 is driven under the control of U1, and the V-type electrothermal actuator II drives the second hook contact 10 under the control of another drive circuit U2, the first hook contact 6 and the second hook contact 10 The circuit is turned on by contact, the circuit is disconnected by the first hook contact 6 and the second hook contact 10 without contact, the driving circuit U1 and the driving circuit U2 are pulse voltages, and there is a phase difference between the driving circuit U1 and the driving circuit U2.

Described V-shaped thermoelectric actuator 1 comprises the first V-shaped beam 2-1 of three equal distances, the second V-shaped beam 2-2, the third V-shaped beam 2-3, the first V-shaped beam 2-1 , the second V-shaped beam 2-2, the third V-shaped beam 2-3 with a spacing of 100um-110um, a length of 1060um-1070um, a width of 36um-39um, and an angle of 9°-10° with the horizontal direction; the first V-shaped beam 2-1. Both ends of the second V-shaped beam 2-2 and the third V-shaped beam 2-3 are connected to the first electrode anchor point 1-1 and the second electrode anchor point 1-2, and the first V-shaped beam 2 -1. The middle of the second V-shaped beam 2-2 and the third V-shaped beam 2-3 is connected through the vertical beam 3, the upper end of the vertical beam 3 is connected with the lower end of the s-shaped wire 8, and the upper end of the s-shaped wire 8 Connect with wire electrode 9; the lower end of vertical beam 3 is connected with the upper end of first flexible beam 4-1, the lower end of first flexible beam 4-1 is vertically connected with the front end of lever 5, and the front end of lever 5 is connected with the second flexible beam The lower end of 4-2 is vertically connected, the upper end of the second flexible beam 4-2 is connected with the anchor point 7, the end of the lever 5 is connected with the first hook contact 6, the first flexible beam 4-1, the second flexible beam The beam 4-2 is 290um-300um long, 10um-12um wide, and the magnification of the lever 5 is 19-21.

The difference between the V-type thermoelectric actuator II and the V-type thermoelectric actuator I is: the first flexible beam 4-1 of the V-type thermoelectric actuator II is connected to the anchor point 7, and the second flexible beam 4-2 is connected to the anchor point 7. The vertical beam 3 is connected, the end of the lever 5 is connected with the second hook contact 10, and the rest of the composition and connection methods are the same as those of the V-type thermoelectric actuator 1.

The first electrode anchor point 1-1, the second electrode anchor point 1-2, the anchor point 7, and the wire electrode 9 are all fixed on the square base 11, and the rest of the structures are floating and movable structures.

The first V-shaped beam 2-1, the second V-shaped beam 2-2, the third V-shaped beam 2-3, the first flexible beam 4-1, the second flexible beam 4-2, the lever 5, the first A hook-shaped contact 6, an s-shaped wire 8, and a second hook-shaped contact 10 are all made of silicon material.

The electrothermally driven bistable MEMS switch is prepared using MEMS technology.

Referring to Figure 2, the first hook-shaped contact 6 and the second hook-shaped contact 10 cooperate to have a self-locking function. With this structural design, the switch only needs to be excited by a pulse voltage signal to complete normally closed and closed. Mutual conversion between normally open states; the specific movement process is as follows:

a. The switch is off;

b. The voltage of the driving circuit U1 becomes high level, driving the first hook-shaped contact 6 to move upward;

c. The voltage of the driving circuit U1 remains unchanged, and the voltage of the driving circuit U2 becomes high level, driving the second hook-shaped contact 10 to move to the left;

d. The voltage of the driving circuit U1 becomes low level, the first hook contact 6 returns to the initial position, and the voltage of the driving circuit U2 remains unchanged;

e. The voltage of the driving circuit U2 becomes low level, and the second hook-shaped contact 10 returns to the initial position. Since the first hook-shaped contact 6 is located on the movement path of the second hook-shaped contact 10 at this time, the second hook-shaped contact 10 A hook-shaped contact 6 contacts with a second hook-shaped contact 10 to complete the switch from open to closed. In the same way, the switch from closed to open can be realized only by reversing the above process.

Referring to Figure 3, there is a certain phase difference between the driving circuit U1 and the driving circuit U2. Figure 3a shows that the driving circuit U1 and the driving circuit U2 realize the switch from on to off, and the phase of the driving circuit U2 lags behind the driving circuit U1; Figure 3b shows the driving circuit U1, The drive circuit U2 realizes the switch from closed to open, and the phase of the drive circuit U1 lags behind the drive circuit U2.

Principle of the present invention is:

Using the thermoelectric effect and thermal expansion effect of the silicon material of the first V-shaped beam 2-1, the second V-shaped beam 2-2, and the third V-shaped beam 2-3, by applying voltage to the silicon material to cause thermal deformation, thereby driving Hook contact movement.

When the drive circuit U1 is added to the first electrode anchor point 1-1 and the second electrode anchor point 1-2, the first V-shaped beam 2-1, the second V-shaped beam 2-2, and the third V-shaped beam 2- 3 has a current flowing through it, and the current makes it heat and expand, resulting in an upward displacement, and the vertical beam 3 drives the first flexible beam 4-1 to move upward. At this time, the lever 5 moves upward with the first flexible beam 4-1, The first hook-shaped contact 6 connected to the end of the lever 5 also moves upwards. When the driving circuit U1 is applied, the first hook-shaped contact 6 returns to its original position. In this way, the first hook-shaped contact 6 reciprocates in the plane . The second hook contact 10 of the V-type thermoelectric actuator II also reciprocates according to this principle, and controlling the movement sequence of the first hook contact 6 and the second hook contact 10 can control the movement of the two hook contacts. contact status.

Claims (7)

1. a kind of electrothermal drive bistable state mems switch, including square base (11), it is characterised in that：Square base (11) Upper vertical distribution has V-type electrical actuator I and V-type electrical actuator II, V-type electrical actuator I to be controlled in drive circuit U1 all the way System the first hook contact (6) of lower driving, V-type electrical actuator II drive the second hook to touch under another way drive circuit U2 controls Head (10), the first hook contact (6) and second hook contact (10) contact are turning circuit, the first hook contact (6) and second Hook contact (10) does not contact i.e. disconnecting circuit, and drive circuit U1, drive circuit U2 are pulse voltage, drive circuit U1 and driving Circuit U 2 has phase difference.

A kind of 2. electrothermal drive bistable state mems switch according to claim 1, it is characterised in that：Described V-type thermoelectricity Actuator (I) includes three equidistant first V-type beams (2-1), the second V-type beam (2-2), the 3rd V-type beam (2-3), the first V-type Beam (2-1), the second V-type beam (2-2), the both ends of the 3rd V-type beam (2-3) and first electrode anchor point (1-1) and second electrode anchor point (1-2) is connected, and the first V-type beam (2-1), the second V-type beam (2-2), the centre of the 3rd V-type beam (2-3) are by vertical beam (3) through company Connect, the upper end of vertical beam (3) is connected with s types wire (8) lower end, and the upper end of s types wire (8) is connected with lead electrode (9)；Vertically The lower end of beam (3) is connected with the first flexible beam (4-1) upper end, and the first flexible beam (4-1) lower end is vertical with the front end of lever (5) to be connected Connect, the front end termination of lever (5) and the lower end vertical connection of the second flexible beam (4-2), the upper end of the second flexible beam (4-2) and anchor Point (7) is connected, and the end termination of lever (5) is connected with the first hook contact (6)；

Described V-type thermoelectricity actuator II and V-type thermoelectricity actuator I's is a difference in that：The first of V-type thermoelectricity actuator II is soft Property beam (4-1) be connected with anchor point (7), the second flexible beam (4-2) is connected with vertical beam (3), the end of lever (5) and the second hook Contact (10) connects, and remaining composition is identical with V-type thermoelectricity actuator I with connected mode；

Described first electrode anchor point (1-1), second electrode anchor point (1-2), anchor point (7), lead electrode (9) are each attached to pros In shape substrate (11), remaining structure is suspension movable structure.

A kind of 3. electrothermal drive bistable state mems switch according to claim 2, it is characterised in that：The first described V-type Beam (2-1), the second V-type beam (2-2), the 3rd V-type beam (2-3), the first flexible beam (4-1), the second flexible beam (4-2), lever (5), the first hook contact (6), s types wire (8), the second hook contact (10) are made using silicon materials.

A kind of 4. electrothermal drive bistable state mems switch according to claim 1, it is characterised in that：The first described hook Contact (6), the second hook contact (10), which coordinate, possesses auto-lock function.

A kind of 5. electrothermal drive bistable state mems switch according to claim 1, it is characterised in that：Described electrothermal drive Bistable state mems switch is prepared using MEMS technology.

A kind of 6. electrothermal drive bistable state mems switch according to claim 2, it is characterised in that：The first described V-type Beam (2-1), the second V-type beam (2-2), the 3rd V-type beam (2-3) spacing 100um-110um, long 1060um-1070um, width 36um-39um, 9 ° -10 ° of the angle with horizontal direction.

A kind of 7. electrothermal drive bistable state mems switch according to claim 2, it is characterised in that：Described first is flexible Beam (4-1), the second flexible beam (4-2) long 290um-300um, wide 10um-12um, lever (5) multiplication factor are 19-21.