WO2020057078A1

WO2020057078A1 - Near field coupling driven micromechanical cantilever beam actuator and manufacture method therefor

Info

Publication number: WO2020057078A1
Application number: PCT/CN2019/079131
Authority: WO
Inventors: 王立峰; 董蕾; 黄庆安
Original assignee: 东南大学
Priority date: 2018-09-18
Filing date: 2019-03-21
Publication date: 2020-03-26
Also published as: CN109292724A

Abstract

Disclosed is a near field coupling driven micromechanical cantilever beam actuator, comprising a substrate (110), an insulating medium layer (120), a fixing element (130), an inductance cantilever beam structure (140), and an excitation inductance structure (150), wherein the insulating medium layer (120) is provided on a side of the substrate (110) in the thickness direction thereof; the fixing element (130) is provided on a side of the insulating medium layer (120) that faces away from the substrate (110); the inductance cantilever beam structure (140) is connected to the fixing element (130) and suspended above the insulating medium layer (120); and the excitation inductance structure (150) is located above the inductance cantilever beam structure (140), two ends of the excitation inductance structure are used for connecting alternating signal sources, and a near field coupling of electromagnetic field is formed between the inductance cantilever beam structure (140) and the excitation inductance structure (150). The micromechanical cantilever beam actuator is of a wireless type, can be used in a closed environment or a rotating environment, has an integrated structure on a chip, and has the advantages of having a small size and fast response and being capable of mass production. Further disclosed is a manufacture method for the micromechanical cantilever beam actuator.

Description

Near-field coupling-driven micromechanical cantilever beam actuator and manufacturing method thereof

Technical field

The invention relates to the field of microelectronics technology, in particular to a micromechanical cantilever beam actuator driven by near field coupling and a manufacturing method thereof.

Background technique

The micro-actuator is one of the core components of a micro-system. It can provide power to the micro-system and can also become the operation and execution unit of the micro-system. Micro-actuators have many different execution methods. Common driving methods include electrostatic drive, electromagnetic drive, thermal drive, and light drive.

Among them, the three most commonly used are electric drive, magnetic drive and thermal drive. Electrostatic microactuators are small in size, simple in structure, and fast in response, and are currently the most widely used microactuators. However, the output force of electrostatic actuators is much smaller than other driving forms. Thermal drive is to use the thermal expansion effect to cause a certain deformation of the driving part, and to realize the output of force calmly. The power consumption of thermal drive is large, and the accuracy is difficult to control. Magnetically driven actuators use magnetic fields to deflect magnetic substances or conductive conductors. Micromotor is a kind of magnetic driver, which can produce larger torque and higher speed. Shape memory alloys can also be used to make microactuators. The shape of the shape memory alloy switches between the two states when it changes between high and low temperatures. Using this characteristic of shape memory alloys, microactuators such as micro-tweezers have been fabricated.

Electrically driven microactuators are mostly wired. This wired electric drive actuator is no longer applicable in confined spaces, inside the human body, and in rotating environments. For these environments, electrically driven microactuators that work wirelessly are needed.

Summary of the Invention

The invention aims to solve at least one of the technical problems existing in the prior art, and proposes a micromechanical cantilever beam actuator driven by near field coupling and a manufacturing method thereof.

In order to achieve the above object, a first aspect of the present invention provides a micromechanical cantilever actuator driven by near-field coupling, including:

Substrate

An insulating dielectric layer disposed on one side of the substrate in a thickness direction thereof;

A fixing member, the fixing member is disposed on a side of the insulating medium layer facing away from the substrate;

An inductive cantilever beam structure, the inductive cantilever beam structure is connected to the fixing member, and the inductive cantilever beam structure is suspended above the insulating dielectric layer;

An excitation inductance structure, the excitation inductance structure is located above the inductance cantilever structure, and a near-field coupling of an electromagnetic field is formed between the excitation inductance structure and the inductance cantilever structure;

Two ends of the excitation inductance structure are used to connect an AC signal source.

Optionally, a first end of the inductive cantilever beam structure is fixedly connected to the fixing member, and a second end of the inductive cantilever beam structure is suspended above the insulating dielectric layer.

Optionally, the fixing member is located in an edge region of the insulating dielectric layer, and a second end of the inductive cantilever structure is suspended in a central region of the insulating dielectric layer.

Optionally, the inductive cantilever structure includes a first metal film, a dielectric film, and a second metal film which are disposed in this order, the first metal film faces the insulating dielectric layer, and the second metal film faces away from the insulation. A dielectric layer, and the first metal film and the second metal film constitute an LC resonance circuit.

Optionally, the first metal film and the second metal film are two metals with large differences in thermal expansion coefficients.

Optionally, a thermal expansion coefficient of the first metal film is greater than a thermal expansion coefficient of the second metal film.

Optionally, a thermal expansion coefficient of the first metal film is smaller than a thermal expansion coefficient of the second metal film.

Optionally, the signal frequency of the AC signal source is equal to the resonance frequency of the inductive cantilever structure.

According to a second aspect of the present invention, a method for manufacturing a near-field coupling-driven micromechanical cantilever beam actuator is provided. The near-field coupling-driven micromechanical cantilever beam actuator includes the near-field coupling drive described above. Micromechanical cantilever actuator, the manufacturing method includes:

Step S110: deposit an insulating dielectric layer on the surface of the substrate;

Step S120: deposit a dielectric layer on the surface of the insulating dielectric layer, and etch to form the fixing member;

Step S130: apply a sacrificial layer, and perform photolithography and etching;

Step S140: depositing and forming the inductive cantilever beam structure;

Step S150: The sacrificial layer is etched to release the inductive cantilever beam structure.

Optionally, step S140 specifically includes:

Depositing a first metal layer, a dielectric layer, and a second metal layer on the surface of the insulating dielectric layer in sequence;

Photoetching and etching the first metal layer, the dielectric layer, and the second metal layer to form the inductor cantilever structure. .

The micromechanical cantilever beam actuator of the present invention and a manufacturing method thereof include a substrate, an insulating medium layer, a fixing member, an inductive cantilever beam structure, and an exciting inductance structure. The inductive cantilever beam structure is connected to the fixing member, and the inductive cantilever beam structure is suspended above the insulating dielectric layer. The excitation inductance structure is located above the inductance cantilever structure, and a near-field coupling of an electromagnetic field is formed between the excitation inductance structure and the inductance cantilever structure. The micromechanical cantilever actuator of the present invention works wirelessly and can work in harsh environments such as closed environments or rotating environments. In addition, the micromechanical cantilever actuator of the present invention uses an on-chip integrated structure, which has a small size and fast response. And the advantages of mass production.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are used to provide a further understanding of the present invention, and constitute a part of the specification. Together with the following specific embodiments, the drawings are used to explain the present invention, but not to limit the present invention. In the drawings:

1 is a perspective view of a micromechanical cantilever actuator in a first embodiment of the present invention;

2 is a front view of a micromechanical cantilever actuator in a second embodiment of the present invention;

FIG. 3 is a flowchart of a method for manufacturing a micromechanical cantilever actuator in a third embodiment of the present invention.

detailed description

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not intended to limit the present invention.

As shown in FIG. 1 and FIG. 2, a first aspect of the present invention relates to a near-field coupled micromechanical cantilever actuator 100. The micromechanical cantilever actuator 100 includes a substrate 110, an insulating dielectric layer 120, The fixing member 130, the inductive cantilever structure 140 and the excitation inductive structure 150. The insulating dielectric layer 120 is disposed on one side of the substrate 110 in a thickness direction thereof. For example, as shown in FIGS. 1 and 2, the insulating dielectric layer 120 is disposed on an upper surface of the substrate 110. The fixing member 130 is disposed on a side of the insulating medium layer 120 facing away from the substrate 110, that is, as shown in FIGS. 1 and 2, the fixing member 130 is disposed on an upper surface of the insulating medium layer 120. . The inductive cantilever beam structure 140 is connected to the fixing member 130, and the inductive cantilever beam structure 140 is suspended above the insulating dielectric layer 120. The exciting inductor structure 150 is located above the inductive cantilever structure 140, and a near-field coupling of an electromagnetic field is formed between the exciting inductor structure 150 and the inductive cantilever structure 140. Two ends of the excitation inductance structure 150 are used to connect an AC signal source S.

The micromechanical cantilever actuator 100 of the structure of this embodiment includes a substrate 110, an insulating dielectric layer 120, a fixing member 130, an inductive cantilever structure 140, and an excitation inductive structure 150. The inductive cantilever beam structure 140 is connected to the fixing member 130, and the inductive cantilever beam structure 140 is suspended above the insulating dielectric layer 120. The exciting inductor structure 150 is located above the inductive cantilever structure 140, and a near-field coupling of an electromagnetic field is formed between the exciting inductor structure 150 and the inductive cantilever structure 140. Therefore, the micromechanical cantilever actuator 100 in this embodiment works wirelessly and can work in a closed environment or a harsh environment such as a rotating environment. In addition, the micromechanical cantilever actuator 100 in the structure of this embodiment uses The on-chip integrated structure has the advantages of small size, fast response and mass production.

It should be noted that the specific distance of the inductive cantilever structure 140 suspended above the insulating dielectric layer 120 is not limited. In practical applications, the height dimension of the fixing member 130 can be set according to actual needs, so that The size of the inductive cantilever beam structure 140 from above the insulating dielectric layer 120 may be defined indirectly.

It should further be noted that the specific distance between the excitation inductor structure 150 and the inductor cantilever structure 140 is not limited. In practical applications, the excitation inductor structure 150 and the inductor may be limited according to actual needs. The distance between the cantilever beam structures 140, however, the distance between the two should satisfy the near-field coupling that forms an electromagnetic field between the excitation inductive structure 150 and the inductive cantilever structure 140.

Specifically, as shown in FIGS. 1 and 2, a first end of the inductive cantilever structure 140 is fixedly connected to the fixing member 130, and a second end of the inductive cantilever structure 140 is suspended in the insulating dielectric layer. Above 120.

As shown in FIG. 1 and FIG. 2, the fixing member 130 may be located at an edge region of the insulating dielectric layer 120, and a second end of the inductive cantilever structure 140 is suspended in a central region of the insulating dielectric layer 120.

As shown in FIG. 1 and FIG. 2, the inductive cantilever structure 140 includes a first metal film 141, a dielectric film 142, and a second metal film 143 disposed in this order. The first metal film 141 faces the insulating dielectric layer 120. The second metal film 143 faces away from the insulating dielectric layer 120, and the first metal film 141 and the second metal film 143 form an LC resonance circuit.

Optionally, the first metal film 141 and the second metal film 143 are two metals with large differences in thermal expansion coefficients.

Specifically, due to the near-field coupling principle, the AC signal on the excitation inductive structure 150 is wirelessly coupled to the inductive cantilever structure 140. The AC signal coupled to the inductive cantilever structure 140 then generates Joule heat on the inductive cantilever structure 140. Because the thermal expansion coefficients of the first metal film 141 and the second metal film 143 are different, when the temperature of the inductive cantilever structure 140 changes, the volume expansion amounts of the first metal film 141 and the second metal film 143 will be different. The unequal volume expansion of the first metal film 141 and the second metal film 143 causes thermal stress between the first metal film 141 and the second metal film 143. The thermal stress generated between the first metal film 141 and the second metal film 143 may eventually deflect the inductive cantilever structure 140.

Specifically, the thermal expansion coefficient of the first metal film 141 is greater than the thermal expansion coefficient of the second metal film 143. In this way, when the temperature of the inductive cantilever structure 140 rises, since the thermal expansion coefficient of the first metal film 141 is greater than that of the second metal film 143, the thermal stress generated by the first metal film 141 will cause the inductive cantilever structure 140 to deflect upward.

Specifically, the thermal expansion coefficient of the first metal film 141 is smaller than the thermal expansion coefficient of the second metal film 143. In this way, when the temperature of the inductive cantilever structure 140 rises, because the thermal expansion coefficient of the first metal film 141 is smaller than the thermal expansion coefficient of the second metal film 143, the thermal stress generated by it will cause the inductive cantilever structure 140 to deflect downward.

As shown in FIGS. 1 and 2, the signal frequency of the AC signal source S is equal to the resonance frequency of the inductive cantilever structure 140. This is because as long as an AC signal is loaded on the excitation inductance structure 150, the inductance cantilever structure 140 can be deflected. In order to maximize the efficiency of near-field coupling, the frequency of the loaded AC signal is the same as the LC resonance frequency of the inductive cantilever structure 140. By adjusting the amplitude of the loaded AC signal, the deflection amplitude of the inductive cantilever structure 140 can be controlled.

The second aspect of the present invention, as shown in FIG. 3, provides a manufacturing method S100 of a near-field coupling-driven micromechanical cantilever beam actuator. The near-field coupling-driven micromechanical cantilever beam actuator includes the previously described For the near-field coupling-driven micromechanical cantilever actuator, reference may be specifically made to the foregoing related records, and details are not described herein. The manufacturing method includes:

Step S130: apply a sacrificial layer, and perform photolithography and etching;

Step S140: depositing and forming the inductive cantilever beam structure;

In the manufacturing method S100 of the micromechanical cantilever actuator of the structure of this embodiment, a dielectric layer is first deposited on the surface of the substrate, and then a dielectric layer is deposited on the surface of the dielectric layer and etched. The fixing member is formed, and then, a sacrificial layer is coated, and photolithography and etching are performed. After that, the inductor cantilever structure is formed by deposition. Finally, the sacrificial layer is etched to release the inductor cantilever structure. Therefore, the manufactured micromechanical cantilever actuator can work wirelessly and can work in harsh environments such as closed environments or rotating environments. In addition, it uses an on-chip integrated structure, which has a small size, fast response, and mass production. advantage.

Optionally, step S140 specifically includes:

Photoetching and etching the first metal layer, the dielectric layer, and the second metal layer to form the inductor cantilever structure.

It can be understood that the above embodiments are merely exemplary embodiments used to explain the principle of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various variations and improvements can be made without departing from the spirit and essence of the present invention, and these variations and improvements are also considered as the protection scope of the present invention.

Claims

A near-field coupling-driven micromechanical cantilever beam actuator is characterized in that it includes:

Substrate

An insulating dielectric layer disposed on one side of the substrate in a thickness direction thereof;

A fixing member, the fixing member is disposed on a side of the insulating medium layer facing away from the substrate;

An inductive cantilever beam structure, the inductive cantilever beam structure is connected to the fixing member, and the inductive cantilever beam structure is suspended above the insulating dielectric layer;

An excitation inductance structure, the excitation inductance structure is located above the inductance cantilever structure, and a near-field coupling of an electromagnetic field is formed between the excitation inductance structure and the inductance cantilever structure;

Two ends of the excitation inductance structure are used to connect an AC signal source.
The micromechanical cantilever actuator according to claim 1, wherein a first end of the inductive cantilever structure is fixedly connected to the fixing member, and a second end of the inductive cantilever structure is suspended in the Above the dielectric layer.
The micromechanical cantilever actuator according to claim 2, wherein the fixing member is located at an edge region of the insulating dielectric layer, and a second end of the inductive cantilever structure is suspended in the insulating dielectric layer. The central area.
The micromechanical cantilever actuator according to claim 1, wherein the inductive cantilever structure includes a first metal film, a dielectric film, and a second metal film which are sequentially arranged, and the first metal film faces the An insulating dielectric layer, the second metal film faces away from the insulating dielectric layer, and the first metal film and the second metal film constitute an LC resonance circuit.
The micromechanical cantilever actuator according to claim 4, wherein the first metal film and the second metal film are two metals with large differences in thermal expansion coefficients.
The micromechanical cantilever actuator according to claim 5, wherein a thermal expansion coefficient of the first metal film is greater than a thermal expansion coefficient of the second metal film.
The micromechanical cantilever actuator according to claim 5, wherein a thermal expansion coefficient of the first metal film is smaller than a thermal expansion coefficient of the second metal film.
The micromechanical cantilever actuator according to any one of claims 1 to 7, wherein a signal frequency of the AC signal source is equal to a resonance frequency of the inductive cantilever structure.
A manufacturing method of a near-field coupling-driven micromechanical cantilever beam actuator, characterized in that the near-field coupling-driven micromechanical cantilever beam actuator includes a near-field coupling according to any one of claims 1 to 9. Driven micromechanical cantilever beam actuator, the manufacturing method includes:

Step S110: deposit an insulating dielectric layer on the surface of the substrate;

Step S120: deposit a dielectric layer on the surface of the insulating dielectric layer, and etch to form the fixing member;

Step S130: apply a sacrificial layer, and perform photolithography and etching;

Step S140: depositing and forming the inductive cantilever beam structure;

Step S150: The sacrificial layer is etched to release the inductive cantilever beam structure.
The method according to claim 9, wherein step S140 specifically comprises:

Depositing a first metal layer, a dielectric layer, and a second metal layer on the surface of the insulating dielectric layer in sequence;

Photoetching and etching the first metal layer, the dielectric layer, and the second metal layer to form the inductor cantilever structure.