CN108428786B

CN108428786B - Preparation method of micro-angle driving device

Info

Publication number: CN108428786B
Application number: CN201810253357.9A
Authority: CN
Inventors: 郭玉华
Original assignee: Zhejiang Baofeng Printing & Dying Co ltd
Current assignee: ZHEJIANG BAOFENG PRINTING & DYING Co.,Ltd.
Priority date: 2018-03-26
Filing date: 2018-03-26
Publication date: 2020-10-02
Anticipated expiration: 2038-03-26
Also published as: CN108428786A

Abstract

The invention discloses a preparation method of a micro-angle driving device, which comprises the steps of providing a substrate with an opening structure, forming a double-polished silicon dioxide wafer with a suspension structure, a bonding layer, a lower electrode, a piezoelectric layer and a Ti/Pt upper electrode lamination layer above the opening, and forming a special-shaped structure after patterning. The invention provides a preparation method of a micro-angle driving device, aiming at the problems that in the prior art, a rectangular piezoelectric device is usually adopted, displacement driving is realized through the extension and retraction of the piezoelectric device, but the driving efficiency and the displacement range of the piezoelectric device are required to be improved.

Description

Preparation method of micro-angle driving device

Technical Field

The invention relates to the field of driving devices, in particular to a preparation method of a micro-angle driving device.

Background

The micro-mechanical technology has become a hot technique in the modern technology field, and is also a key technique for nano-technology research. In order to obtain accurate driving of micro-displacement, the piezoelectric driver gradually enters the visual field of people, and obtains wide attention with the advantages of high control accuracy, corresponding rapidness and the like. The piezoelectric driving technology is based on the inverse piezoelectric effect of piezoelectric ceramic material and can produce rotation or linear motion through controlling its mechanical deformation. It has the advantages of simple structure, low speed and large moment. There are 3 types of such motors, ultrasonic, peristaltic and inertial, respectively. The ultrasonic wave type is based on inverse piezoelectric effect, and uses mechanical vibration in ultrasonic frequency domain as driving technology to generate motion through mechanical transformation under the control of electric energy. The peristaltic and inertial types are mainly used for linear motion. Piezoelectric actuators have been used in applications requiring precise position control, such as scanning electron microscopy and microsurgery. In the prior art, a rectangular piezoelectric device is generally adopted, and displacement driving is realized through the extension and contraction of the piezoelectric device, but the driving efficiency and the displacement range of the piezoelectric device need to be improved. The application provides a piezoelectric driving device with dysmorphism structure, has realized higher drive efficiency and great drive displacement.

Disclosure of Invention

The present invention is directed to a method for manufacturing a micro-angle driving device, so as to solve the problems of the prior art that a rectangular piezoelectric device is adopted, and displacement driving is achieved by stretching and contracting the piezoelectric device, but the driving efficiency and the displacement range of the piezoelectric device need to be improved. According to the preferable technical scheme in the technical schemes provided by the invention, the connecting arm with the special-shaped structure is adopted, so that the bending stress can be concentrated to the middle narrow area, and the deformation range is enlarged by utilizing the smaller elastic coefficient of the middle narrow area, so that larger driving displacement is obtained; meanwhile, the bending is concentrated in the narrow middle area, so that compared with a connecting arm with a rectangular structure, the deformation and the stress of the connecting part at the two ends of the connecting arm can be reduced, cracks are prevented from being generated at the connecting part, and the reliability of the device is improved.

In order to achieve the above object, the present invention provides a method for manufacturing a micro-angle driving device, comprising:

the method comprises the following steps of (1) providing a substrate, and forming an opening on the substrate;

step (2), providing a double-polished silicon dioxide wafer, and fixing the double-polished silicon dioxide wafer above the opening;

step (3), sequentially preparing an adhesive layer, a lower electrode, a piezoelectric layer and a Ti/Pt upper electrode on the double-throw silicon dioxide wafer, and forming a piezoelectric unit with a special-shaped structure after patterning, wherein the special-shaped structure is a strip-shaped structure with the width of two ends larger than the width of the middle part;

patterning the double-polished double-silicon-oxide wafer by using the piezoelectric unit and a mask to form a central region and two groups of supporting arms, wherein the central region is connected to the substrate through the two groups of symmetrically arranged supporting arms, each group of supporting arms is provided with a continuous structure, the continuous structure comprises a joint and a connecting arm which are positioned at the end part of each supporting arm, each connecting arm is provided with a special-shaped structure corresponding to the piezoelectric unit, and the tail part of each supporting arm is connected to the substrate so as to realize the suspension arrangement of the supporting arms and the position above the opening;

a step (5) of electrically connecting the driving unit to the lower electrode and the upper electrode of the piezoelectric unit;

and (6) preparing an isolation protection layer covering the piezoelectric unit.

And (4) each group of support arms is provided with 1-8 connecting arms which are arranged in parallel, and each connecting arm is correspondingly provided with one or more piezoelectric units.

Wherein, in step (4), when each set of support arms has 2-8 connecting arms, the connecting arms are arranged in a serpentine continuous structure. The piezoelectric layers on adjacent support arms have opposite polarization directions and bend in opposite directions when driven with common upper and lower electrodes, thereby achieving a greater twist angle output.

Wherein, in the step (4), the joint has a rectangular structure or a circular arc structure.

Wherein the thickness of the double-polished double-oxygen silicon wafer is 25-90 microns.

Wherein the distance between the connecting arms is 2.5-3 microns, and the width of the middle of the connecting arm is 1.6-2 microns. Through comparative analysis, the connecting arm structure in the proportion range can take the driving accuracy and the driving range into consideration, and has the best driving performance.

Wherein the adhesive layer and the lower electrode in the step (3) are replaced by a conductive layer having adhesive properties.

In the step 4, a mask used for patterning the double-polished hydrogen peroxide wafer is the lower electrode. In the process of forming the lower electrode, the patterned lower electrode is formed through mask deposition or a process of depositing first and then patterning, and the lower electrode and the piezoelectric layer/upper electrode laminated layer positioned on the lower electrode are used as etching masks of the double-oxidation silicon wafer, so that the use of the masks is reduced, and the preparation cost is saved.

The preparation process of the piezoelectric material layer comprises the steps of firstly preparing piezoelectric single crystals with the thickness larger than the preset thickness, arranging the piezoelectric single crystals on the lower electrode with the cohesiveness, and thinning the piezoelectric single crystals through an etching thinning process.

In summary, the invention provides a method for manufacturing a micro-angle driving device, which can concentrate bending stress to a middle narrow region by using a piezoelectric unit and a supporting arm with special-shaped structures, and enlarge a deformation range by using a smaller elastic coefficient of the middle narrow region, thereby obtaining larger driving displacement; meanwhile, the bending is concentrated in the narrow middle area, so that compared with a connecting arm with a rectangular structure, the deformation and stress of the connecting position of the two ends of the connecting arm can be reduced, cracks are prevented from being generated at the connecting position, and the reliability of the device is improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 to 5 are flow charts of a method for manufacturing a micro angle driving device according to example 1 of the present invention, and fig. 3 and 4 are a front view of the device in the upper part and a plan view of the device in the lower part;

fig. 6 is a flowchart of a method for manufacturing a micro-angle driving device according to embodiment 2 of the present invention.

The reference numerals are explained below:

1. a Si substrate; 2. double polishing a silicon dioxide wafer; 4. a piezoelectric unit; 41-44 and 91-94, piezoelectric units; 5, a joint; 6. a central region; 7. 71 connecting the arms.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be described in detail below. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the examples given herein without any inventive step, are within the scope of the present invention.

Specific embodiments are as follows.

Example 1

Step (1), as shown in fig. 1, providing a substrate 1, and forming an opening on the substrate 1;

step (2), as shown in fig. 2, providing a double-polished silicon dioxide wafer 2, and fixing the double-polished silicon dioxide wafer 2 above the opening;

step (3), as shown in fig. 3, preparing an adhesive layer, a lower electrode, a piezoelectric layer, and a Ti/Pt upper electrode on the double-throw silicon dioxide wafer in sequence, patterning the adhesive layer, the lower electrode, the piezoelectric layer, and the Ti/Pt upper electrode to form a piezoelectric unit 41, a piezoelectric unit 42, a piezoelectric unit 43, and a piezoelectric unit 44, which have a special-shaped structure, where the special-shaped structure is a strip structure with a width at both ends greater than a width in the middle;

patterning the double-polished double-silicon-oxide wafer by using the piezoelectric unit and a mask to form a central region 6 and two groups of supporting arms, wherein the central region is connected to the substrate through the two groups of symmetrically arranged supporting arms, each group of supporting arms is provided with a continuous structure, the continuous structure comprises a joint and a connecting arm which are positioned at the end part of each supporting arm, the connecting arm is provided with a special-shaped structure corresponding to the piezoelectric unit, and the tail part of each supporting arm is connected to the substrate; the four piezoelectric units are respectively and independently arranged to realize reverse deformation of the piezoelectric units on the same side, so that torsional driving of the central area is realized.

Step (5), electrically connecting the driving unit to the lower electrode and the upper electrode of the piezoelectric unit through the lead 8; and (6) preparing an isolation protection layer covering the piezoelectric unit.

Example 2

Example 2 was prepared substantially identically to example 1, except that each set of support arms in step (3) and step (4) formation had 2 connecting arms arranged in a meandering continuous structure, adjacent connecting arms connected by joints 5, the spacing of the connecting arms being 2.5 microns and the width between the connecting arms being 1.8 microns as shown in figure 6. The piezoelectric units disposed conformally with the connecting arm are the

piezoelectric units

91 and 92 on the upper side supporting arm and the

piezoelectric units

93 and 94 on the lower side supporting arm, wherein the

piezoelectric units

91 and 92 deform in opposite directions, the

piezoelectric units

93 and 94 deform in opposite directions, and meanwhile, the deformation directions of the upper and lower side supporting arms are opposite, so that the torsional driving of the central area 61 is realized.

The above description is only a preferred application of the present invention, and it should be noted that, for those skilled in the art, several modifications can be made without departing from the technical principle of the present invention, and these modifications should also be regarded as the protection scope of the present invention.

Claims

1. A method of making a micro-angle actuated device, comprising:

step (3), sequentially preparing an adhesive layer, a lower electrode, a piezoelectric layer and a Ti/Pt upper electrode on the double-throw silicon dioxide wafer, and forming a first piezoelectric unit, a second piezoelectric unit, a third piezoelectric unit and a fourth piezoelectric unit which are in special-shaped structures after patterning, wherein the first piezoelectric unit and the second piezoelectric unit form a strip-shaped special-shaped structure with the width of two ends larger than the width of the middle, and the third piezoelectric unit and the fourth piezoelectric unit form a strip-shaped special-shaped structure with the width of two ends larger than the width of the middle;

patterning the double-polished double-silicon-oxide wafer by using the piezoelectric unit and a mask to form a central region and two groups of supporting arms, wherein the central region is connected to the substrate through the two groups of symmetrically arranged supporting arms, each group of supporting arms is provided with a continuous structure, the continuous structure comprises a joint and a connecting arm which are positioned at the end part of each supporting arm, each connecting arm is provided with a special-shaped structure corresponding to the piezoelectric unit, and the tail part of each supporting arm is connected to the substrate; the first piezoelectric unit, the second piezoelectric unit, the third piezoelectric unit and the fourth piezoelectric unit are respectively and independently arranged to realize reverse deformation of the piezoelectric units on the same side, so that torsional driving of a central area is realized;

2. The method for manufacturing a micro-angle driving device according to claim 1, wherein in the step (4), the joints have a rectangular structure or a circular arc structure.

3. The method of claim 1, wherein the double-polished silicon wafer has a thickness of 25-90 μm.

4. A method of manufacturing a micro-angle actuator as claimed in claim 3, wherein the pitch of the arms is 2.5-3 μm and the width of the middle of the arm is 1.6-2 μm.

5. The method for manufacturing a micro-angle driving device as claimed in claim 1, wherein the adhesive layer and the lower electrode in the step (3) are replaced with an adhesive conductive layer.

6. The method for manufacturing a micro-angle driving device according to claim 5, wherein in the step (4), a mask used for patterning the double-polished silicon dioxide wafer is the lower electrode.

7. The method of claim 1, wherein the piezoelectric layer is formed by preparing a piezoelectric single crystal having a thickness greater than a predetermined thickness, disposing the piezoelectric single crystal on the lower electrode having adhesion, and thinning the piezoelectric single crystal by an etching thinning process.