CN115589213A

CN115589213A - Electrode, piezoelectric device, method of designing piezoelectric device, piezoelectric filter, and electronic apparatus

Info

Publication number: CN115589213A
Application number: CN202211592189.9A
Authority: CN
Inventors: 郑云卓; 王笛
Original assignee: Tianjin Haiteng Microelectronics Co ltd
Current assignee: Tianjin Haiteng Microelectronics Co ltd
Priority date: 2022-12-13
Filing date: 2022-12-13
Publication date: 2023-01-10
Anticipated expiration: 2042-12-13
Also published as: CN115589213B

Abstract

The application provides an electrode, a piezoelectric device, a design method of the piezoelectric device, a piezoelectric filter and an electronic device. The piezoelectric device includes: the piezoelectric layer is arranged on the first electrode, the second electrode is arranged on the second electrode, and the first electrode, the piezoelectric layer, the second electrode, the acoustic mirror and the substrate are sequentially superposed; the overlapping area of the first electrode, the piezoelectric layer, the second electrode and the acoustic mirror in the stacking direction forms an effective area of the piezoelectric device; the effective area comprises a polygonal area and at least one extension area connected with the polygonal area in the same plane; the extension area comprises a base edge and a plurality of fold line edges which are connected in sequence; the base side is one side of the polygonal area, and the plurality of broken line sides are inscribed broken lines of an arc taking the base side as a chord. Some straight edges of the polygon are replaced by multi-segment broken lines inscribed in the circular arc, so that the difference of the relative positions of all the points on the edge of the effective area is increased, the problem that the resonance paths of multiple points possibly exist on the straight edges is eliminated as much as possible, and the performance of the device is improved.

Description

Electrode, piezoelectric device, piezoelectric filter, electronic apparatus, and method of designing piezoelectric device

Technical Field

The present disclosure relates to the field of piezoelectric devices, and particularly to an electrode, a piezoelectric device, a design method thereof, a piezoelectric filter, and an electronic apparatus.

Background

As mobile communication technology enters the 5G era, a large number of 5G mobile terminals and base stations are widely deployed worldwide. The 5G technology inherits the communication frequency band of the previous generation of 4G and 4G-LTE at 700MHz-2.7GHz, and also expands the application at more than 3GHz, such as N77, N78 and N79, and the frequency can reach 5GHz at most. Meanwhile, the Wireless Local Area Network (WLAN) technology mainly represented by Wi-Fi is continuously evolving, wi-Fi 6/6E has entered people's daily life, and the Wi-Fi 6/6E expands the application of more than 6GHz on the basis of the traditional 2.4GHz and 5GHz frequency bands (collectively referred to as Sub 6 GHz). Most of the present mobile communication terminals support the wireless access of the two technologies, and the multi-mode and multi-band technologies gradually become general technical requirements, wherein the radio frequency circuit in charge of the air interface is increasingly complex, but the mobile terminal needs to meet the requirement of miniaturization at the same time, so the market demand for high-performance and miniaturized radio frequency filter devices is also increasing.

At present, the filter devices capable of meeting such requirements are mainly piezoelectric Acoustic Wave filters, and resonators constituting such Acoustic Wave filters mainly include Bulk Acoustic Wave (BAW) resonators and Surface Acoustic Wave (SAW) resonators. The bulk acoustic wave filter has the advantages of higher application frequency, lower insertion loss, faster roll-off edge, larger power capacity, antistatic property and the like, so that the bulk acoustic wave filter is more suitable for the requirements of high-frequency scenes.

The performance of BAW resonators is mainly affected by lateral resonance. When the resonant frequency of a certain mode of transverse resonance is just near the longitudinal main resonant mode (the resonant mode corresponding to the resonant frequency), the energy superposition generated by transverse resonance may be near the main resonant frequency, and the insertion loss of the bulk acoustic wave filter is affected by impedance burrs generated by transverse resonance, thus deteriorating the performance of the device.

In the related art, the shape of the active area of the BAW resonator is generally set to be a polygon without parallel sides, so as to increase the length of the lateral resonance distance of each point on the edge and make the length different as much as possible, thereby improving the performance of the device as much as possible. However, there may still be some point reflection paths similar in the neighboring areas in the straight sides of the polygon, which results in energy superposition, and thus impedance glitches are generated, and the device performance is reduced.

Disclosure of Invention

The application provides an electrode, a piezoelectric device, a design method of the electrode and the piezoelectric device, a piezoelectric filter and electronic equipment, which further improve the transverse resonance distance, disperse the edge points of similar reflection paths and improve the performance of the device.

In a first aspect, the present application provides a piezoelectric device comprising: the piezoelectric layer is arranged on the first electrode, the second electrode is arranged on the second electrode, and the first electrode, the piezoelectric layer, the second electrode, the acoustic mirror and the substrate are sequentially superposed;

the overlapping area of the first electrode, the piezoelectric layer, the second electrode and the acoustic mirror in the stacking direction forms an effective area of the piezoelectric device;

the effective area comprises a polygonal area and at least one extension area connected with the polygonal area in the same plane;

the extension area comprises a base edge and a plurality of fold line edges which are connected in sequence;

the base side is one side of the polygonal area, and the plurality of broken line sides are inscribed broken lines of an arc taking the base side as a chord.

Optionally, the length range of each of the fold line sides is 1 μm to 50 μm.

Optionally, the lengths of the plurality of fold line sides are equal.

Optionally, the polygonal area includes: triangular area, quadrilateral area, pentagonal area, hexagonal area.

Optionally, in the active area, an internal angle corresponding to a vertex of the polygonal area is greater than 90 °.

Optionally, in the active area, an internal angle corresponding to a vertex of the polygonal area is greater than 180 °.

In a second aspect, the present application provides an electrode of a piezoelectric device, the electrode being used as a first electrode and/or a second electrode of the piezoelectric device of the first aspect to form the active region.

In a third aspect, the present application provides a design method of a piezoelectric device, where the piezoelectric device includes a first electrode, a piezoelectric layer, a second electrode, an acoustic mirror, and a substrate, which are sequentially stacked; the overlapping area of the first electrode, the piezoelectric layer, the second electrode and the acoustic mirror in the stacking direction forms an effective area of the piezoelectric device; the effective area comprises a polygonal area and at least one extension area connected with the polygonal area in the same plane; the extension area comprises a base edge and a plurality of fold line edges which are connected in sequence; the method comprises the following steps:

determining a polygonal area;

determining at least one base edge from edges of the polygonal region;

determining an arc taking the base edge as a chord according to a preset curvature;

selecting a corresponding number of insertion end points from the circular arc according to the preset number of broken lines;

and sequentially connecting the end points of the base side and the corresponding number of the insertion end points to form a plurality of broken line sides as the inner broken lines of the circular arc, so that the plurality of broken line sides and the base side form the extension area, and the extension area and the polygonal area form the effective area with the area being the preset area.

In a fourth aspect, the present application provides a piezoelectric filter comprising: a piezoelectric device as claimed in any one of the first to third aspects.

In a fifth aspect, the present application provides an electronic device, comprising: a piezoelectric filter as claimed in the fourth aspect.

In a sixth aspect, the present application provides an apparatus for designing a piezoelectric device, comprising:

a base polygon determination module for determining a polygon area;

a base edge selection module, configured to determine at least one base edge from edges of the polygon area;

the circular arc determining module is used for determining a circular arc taking the base edge as a chord according to a preset curvature;

the insertion point selection module is used for selecting a corresponding number of insertion end points from the circular arc according to the number of preset broken lines;

and the effective area adjusting module is used for sequentially connecting the end points of the base edges and the corresponding quantity of the inserting end points to form a plurality of broken line edges serving as the inner broken lines of the circular arc, so that the broken line edges and the base edges form the extending area, and the extending area and the polygonal area form the effective area with the area being the preset area.

In a seventh aspect, the present application provides a design apparatus for a piezoelectric device, including: a memory and a processor; the memory has stored thereon a computer program that can be loaded by the processor and that executes the design method of the third aspect.

In an eighth aspect, the present application provides a computer-readable storage medium storing a computer program that can be loaded by a processor and executes the design method of the third aspect.

The application provides an electrode, a piezoelectric device, a design method thereof, a piezoelectric filter and an electronic device. The effective area of the piezoelectric device is additionally provided with an extension area on the basis of a polygon, certain straight edges of the polygon are replaced by multi-section broken lines inscribed in an arc, the difference of the relative positions of all points on the edge of the effective area is increased, edge points of similar reflection paths are dispersed, the problem that resonance paths of multiple points possibly exist on the straight edges is similar is eliminated as much as possible, and the performance of the device is improved. Moreover, the result of the arc is still a straight line segment, does not include an arc edge, is easy to realize in design software, and is convenient for parameter calculation of the device.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present application, and those skilled in the art can obtain other drawings without inventive labor.

FIG. 1 is a schematic diagram of a conventional polygonal effective area according to an embodiment of the present application;

fig. 2 is a schematic diagram illustrating a result of a resonant distance analysis performed on the effective area edge sampling point of fig. 1 according to an embodiment of the present disclosure;

FIG. 3 is a schematic diagram of a resonant path from a starting point in FIG. 1 according to an embodiment of the present application;

FIG. 4 is a schematic diagram of a resonant path from another starting point in FIG. 1 according to an embodiment of the present application;

FIG. 5 is a schematic diagram illustrating an analysis of arc-related features according to an embodiment of the present application;

FIG. 6 is a schematic view of an embodiment of the present application showing the process of arcing a line;

FIG. 7 is a schematic view of another embodiment of the present application for arcing a straight line;

FIG. 8 is a schematic diagram of a polygon obtained by performing an arc process on the polygon of FIG. 1 according to an embodiment of the present disclosure;

FIG. 9 is a schematic diagram illustrating a distribution of sampling points of the post-arc polygon of FIG. 8 according to an embodiment of the present disclosure;

FIG. 10 is a schematic diagram illustrating a resonant path from a starting point in FIG. 9 according to an embodiment of the present application;

fig. 11 is a schematic diagram illustrating a result of performing a resonance distance analysis on the effective area edge sampling point in fig. 9 according to an embodiment of the present application;

FIG. 12 is a schematic view of another polygon obtained by performing an arc process on the polygon of FIG. 1 according to an embodiment of the present disclosure;

FIG. 13 is a schematic diagram illustrating a resonant path from a starting point in FIG. 12 according to an embodiment of the present application;

fig. 14 is a schematic diagram illustrating a result of a resonance distance analysis performed on the effective area edge sampling points in fig. 12 according to an embodiment of the present disclosure;

fig. 15 is a schematic diagram of a chip layout structure corresponding to the piezoelectric device having an active area in the quadrilateral shape in fig. 1 according to an embodiment of the present disclosure;

fig. 16 is a schematic diagram of a chip layout structure corresponding to the piezoelectric device of which the active area is a quadrilateral shape after the arcing in fig. 12 according to an embodiment of the present application;

FIG. 17 is a schematic view of a polygon obtained by arcing a triangle according to an embodiment of the present application;

FIG. 18 is a schematic illustration of a resonant path from a starting point in FIG. 17 according to an embodiment of the present application;

fig. 19 is a schematic diagram illustrating a result of a resonance distance analysis performed on the effective area edge sampling points in fig. 17 according to an embodiment of the present application;

fig. 20 is a schematic view of a polygon obtained by performing an arc process on a pentagon according to an embodiment of the present disclosure;

FIG. 21 is a schematic diagram illustrating a resonant path from a starting point in FIG. 20 according to an embodiment of the present application;

fig. 22 is a schematic diagram illustrating a result of a resonance distance analysis performed on the effective area edge sampling points in fig. 20 according to an embodiment of the present disclosure;

fig. 23 is a flowchart of a piezoelectric device design method according to an embodiment of the present application;

fig. 24 is a schematic structural diagram of a design apparatus of a piezoelectric device according to an embodiment of the present application;

fig. 25 is a schematic structural diagram of a piezoelectric device design apparatus according to an embodiment of the present application;

fig. 26 is a schematic structural diagram of a piezoelectric filter according to an embodiment of the present application;

fig. 27 is a schematic structural diagram of an electronic device according to an embodiment of the application.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It is to be understood that the embodiments described are only a few embodiments of the present application and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

In addition, the term "and/or" herein is only one kind of association relationship describing the association object, and means that there may be three kinds of relationships, for example, a and/or B, and may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship, unless otherwise specified.

The following description and the attached drawings are combinedThe examples of the present application are described in further detail. For convenience of comparison and explanation, the effective regions used in the examples of the present application each have an area of 10000 μm ² 。

In the prior art, the shape of the active area of the BAW resonator is generally set to be a polygon without parallel sides, so as to achieve the purpose of increasing the length of the transverse resonance distance of each point on the edge and making the lengths different as much as possible. This approach has certain disadvantages. The straight sides of the polygon may have some point reflection paths in the neighboring regions similar, resulting in energy superposition.

Fig. 1 shows a polygon implementation method in the prior art, wherein a quadrilateral is an edge of an active area of a resonator. As shown in fig. 1, a series of sampling points are provided at intervals of 10 μm on each side as starting points for the lateral resonance analysis, where the leftmost point of the lower horizontal side is a number 1 starting point 101, and the remaining points are numbered in the counterclockwise order for 41 points. With these points as starting points, respectively, the lateral resonance paths are calculated, and the results are shown in the line graph in fig. 2. In FIG. 2, the transverse resonance distance is shown by using logarithmic coordinates, the length of the resonance path corresponding to each point is generally distributed in the range of 1350 μm to 113000 μm, and the median value can reach 10943.9 μm. However, it can also be observed from fig. 2 that there are still some points with shorter resonance distances between adjacent points, and the lateral resonance distances are similar, such as the 23 # starting point 123 and the 24 # starting point 124 identified in the figure.

FIG. 3 is a graph of the resonance path from starting point 123 # 23 with a resonance distance of 1996.1 μm; fig. 4 is a diagram of the resonance path from the starting point No. 24 124, and the resonance distance is 1996.1 μm. It can be seen that the resonance distances corresponding to the two points are the same, and the 2 resonance paths are very close. Analysis shows that the phenomenon is mainly caused by the fact that the number of sides of the quadrangle is small, the edges are straight sides, and the accumulated total paths are completely the same after passing through similar reflection paths and the same reflection times. It can be deduced from the figure that all positions between these two points will generate the same lateral resonance distance, so that their energies will be superimposed at the same frequency point to form impedance glitch.

In the related art, some solutions propose to set a part of edges in the resonator shape as a curve in order to avoid this as much as possible. However, curve Design is difficult to implement in Electronic Design Automation (EDA) software commonly used in the industry. Moreover, it is difficult to accurately calculate the angle between each straight side and the tangent of the curve, and the resonator area, resulting in a deviation in design.

Therefore, how to design a resonator shape to make it simple and easy to implement in EDA software, and at the same time, how to make the lateral resonance distance as large as possible and how to distribute the lateral resonance distance at each point of the edge as distributed as small as possible becomes a problem to be solved in designing the piezoelectric filter.

Based on this, the present application provides an electrode, a piezoelectric device, a design method thereof, a piezoelectric filter, and an electronic apparatus, in which some straight sides of a polygon are replaced with multi-segment broken lines inscribed in an arc, so as to improve the performance of a resonator and simplify the implementation in EDA software.

In some embodiments, the present application provides a piezoelectric device comprising: the piezoelectric acoustic sensor comprises a first electrode, a piezoelectric layer, a second electrode, an acoustic mirror and a substrate which are sequentially superposed. The overlapping area of the first electrode, the piezoelectric layer, the second electrode, and the acoustic mirror in the stacking direction constitutes an effective area of the piezoelectric device. The shape of the active area may be divided into a polygonal area and at least one extended area connected with the polygonal area in the same plane. The extension area comprises a base edge and a plurality of fold line edges which are connected in sequence. The base side of the extending area is one side of the polygonal area, and the plurality of broken line sides are inscribed broken lines of arcs taking the base side as a chord.

It can be understood that a certain side of the polygon is taken as a base side and extends outwards, and an extension area corresponding to the base side is formed by the inner broken line of the arc which is opposite to the base side. Based on the polygon, the extension area corresponding to some sides in the polygon is added to form the effective area. The boundary contour of the active area includes a non-base side in the polygon and an inner polyline side in each extended area. It will be appreciated that when each side of the polygon is taken as a base side, the boundary outline of the active area includes the inner polyline side in each extended area.

According to the piezoelectric device provided by the embodiment, the extension area is added on the basis of the polygon in the effective area, and the effect of arcing the straight edge of the polygon is realized. A straight edge is replaced by a plurality of broken line edges which are internally connected with an arc with the straight line as a chord, the difference of the relative positions of all points on the edge of an effective area is increased, the problem that the resonance paths of multiple points possibly exist on the straight edge are similar is eliminated as much as possible, and the performance of the device is improved. Moreover, the result of the arc is still a straight line segment, does not include an arc edge, is easy to realize in design software, and is convenient for parameter calculation of the device.

The polygonal area may be a triangle, a quadrangle, a pentagon, a hexagon, etc. The specific shape can be selected by the designer according to the requirement. The designer can select a suitable shape according to the layout.

The arc corresponding to the base edge can be an arc with any curvature. In the case where only one chord (base edge) is determined, an infinite number of circles may exist corresponding to different combinations of circle center positions and radii. In different circles, the two end points of the circular arc opposite to the base edge are fixed and are the two end points of the base edge, but the curvatures are different. Likewise, the designer may select the corresponding curvature as desired.

The number of the broken line segments of the inscribed broken line of the same circular arc can be any number, the length of each broken line segment can be any length, and the lengths of different broken line segments can be equal or unequal. In some embodiments, the length of the broken line segment may be set to 1 μm to 50 μm. The smaller the length of the broken line segment is, the closer the inner broken line approaches to the corresponding circular arc; the greater the length of the broken line segment, the stronger the angular sensation of the inscribed broken line.

In some embodiments, for ease of implementation, the inner polylines of the same arc are provided as polyline segments of equal length. Taking any one straight line segment as an example, the process of determining the inner broken line of the arc taking the straight line segment as a chord is as follows. This process is referred to as arcing in this application.

First, some of the features used in this application in relation to circular arcs and their geometrical relationships are described.

As shown in fig. 5, a thick curve above a solid straight line segment in the figure is an arc corresponding to the straight line segment, the straight line segment is a chord of a circle where the arc is located, and the length of the chord is a chord length. The dots on both sides are the end points of the straight line segment and the circular arc. The circular arc is a part of a circle, and the center of the circle where the circular arc is located is the center of the circular arc. The length of the line segment between the circle center and any point on the circular arc is equal, and the length is the radius of the circular arc. The angle between the circle center and the connecting line of the two end points is the angle of the circular arc. The point on the arc with the largest vertical distance from the chord is called the vertex of the arc, and the vertex of the arc is just positioned in the middle of the arc. The perpendicular distance between the apex and the chord is called the arc height. The ratio of arc height to chord length is called the aspect ratio. In this embodiment, the curvature is characterized by a high length ratio. The height-length ratio can be in a range of 0.05 to 0.5. The smaller the height-length ratio is, the smaller the curvature is, the less obvious the protruding effect of the inner connecting fold line obtained after the straight edge is arched is, and the more the protruding effect is close to the original straight edge; the larger the height-length ratio, the larger the curvature, and the more obvious the convex effect of the inner fold line obtained after the arc is.

And interpolating a plurality of insertion points on the circular arc, and sequentially connecting the end points and the insertion points to obtain the inscribed broken line of the circular arc. The number of insertion points determines the number and length of the polylines of the inscribed polyline. In this embodiment, dividing the number of insertion points into odd and even numbers respectively illustrates the corresponding implementation.

Referring to fig. 6 and 7, a straight line segment is composed of an end point 601, an end point 602, and a straight line connecting portion therebetween. When the length of the straight line segment is known, or the positions of two end points of the straight line segment are known, and the set curvature or height-length ratio is combined, a section of circular arc and the corresponding parameters such as the arc height can be uniquely determined. And the set length of the broken line segments or the number of the broken line segments are combined, so that the inscribed broken line of the arc can be uniquely determined.

Therefore, two input variables are needed for realizing the method, wherein one input variable is a parameter for representing the curvature of the circular arc, and the other input variable is a parameter for representing the number of the broken line segments. In the present embodiment, these two variables are characterized by the length L of the broken line segment that interconnects the broken lines and the height-to-length ratio x of the circular arc. The longer the length of the broken line segment is set, the fewer the number of inscribed broken lines inserted into the arc. The larger the height-to-length ratio of the arc is set, the more obviously the obtained arc and the inner fold line thereof are protruded upwards. There are two cases of inserting the number N of broken line segments into the circular arc: one is an even number, as shown in FIG. 6; the other is an odd number as shown in fig. 7.

Fig. 6 is a schematic diagram of determining an even number of broken line segments according to the set height-length ratio x and the set length L of the broken line segments by combining the coordinates of two end points of a known straight line segment to determine the circular arc inscribed broken line.

1. From the coordinates of the end point 601 and the end point 602, the length C of the straight line segment is obtained, as well as the coordinates of the midpoint of the straight line segment. Determining the arc height h according to the length C of the straight line segment and the height-length ratio formula x = h/C; moving the midpoint of the straight line segment upwards (the endpoint 601 of the straight line segment points to the right side of the direction of the endpoint 602) by the arc height h to obtain the vertex 603 of the arc;

2. the vertex is respectively connected with the endpoint 601 and the endpoint 602 to obtain two line segments, and the intersection point coordinates of the perpendicular bisectors of the two line segments are respectively calculated, namely the circle center 604 of the circular arc;

3. calculating the distance between the circle center 604 and the vertex 603 or the two

endpoints

601 and 602, namely the radius R of the circular arc;

4. according to the coordinates of the end point 601, the coordinates of the end point 602 and the coordinates of the circle center 604, the included angle alpha of the circular arc can be calculated;

5. calculating the length of the arc according to the radius R of the arc and the included angle alpha of the arc: AL = pi ra/180;

6. calculating the number of the polyline segments of the inscribed polyline: n = AL/L (rounded up), N =2N (illustrated as N =6 in fig. 6) since N is an even number;

7. the vertex 603 is used as an insertion point N, the position of the other insertion point is obtained by rotating with reference to the position of the center of the circle from the coordinates of the vertex, and the step value of the rotation is alpha/N. Wherein, the angle alpha/N, 2 alpha/N, \ 8230is rotated clockwise, and the insertion points N-1, N-2, \ 8230are respectively obtained when the angle alpha/N is (N-1), and 1 is corresponding to the

insertion points

6052 and 6051 in FIG. 6; rotating angle alpha/N, 2 alpha/N, \ 8230, (N-1) alpha/N towards the counterclockwise direction to respectively obtain insertion points N +1, N +2, \ 8230, and 2N-1, corresponding to

insertion points

6054 and 6055 in the figure. Arranging the obtained insertion points according to the sequence numbers to obtain the coordinate sequences of all the end points of the inscribed fold line: endpoint 1, insertion point 2, \ 8230, insertion point N-1, endpoint 2, corresponding to endpoint 601, insertion point 6051, insertion point 6052, vertex 603, insertion point 6054, insertion point 6055, endpoint 602 in fig. 6. The

broken line segments

6061, 6062 \8230, 8230and 6066 can be generated by connecting the end points, and the broken line segments jointly form an inscribed broken line.

Fig. 7 is a schematic diagram of determining odd-numbered broken line segments according to the set height-length ratio x and the set length L of the broken line segments by combining the coordinates of two end points of a known straight line segment to determine the circular arc inscribed broken line.

Calculation steps 1-5 are exactly the same as in the corresponding embodiment of fig. 6, except that, starting from step 6:

6. calculating the number of the polyline segments of the inscribed polyline: n = AL/L (rounded up), since N is odd, set N =2n +1 (illustrated in fig. 7 as N = 5);

7. starting from the coordinates of the vertex 603, the position of the insertion point is obtained by rotating with reference to the position of the center of the circle, and the step value of the rotation is alpha/N. Wherein, rotating clockwise 0.5 alpha/N, 1.5 alpha/N, \8230, (N-0.5) alpha/N to respectively obtain insertion points N, N-1, \8230, and 1, corresponding to

insertion points

7052 and 7051 in FIG. 7; rotating 0.5 alpha/N, 1.5 alpha/N, \8230; (N-0.5) alpha/N counterclockwise to obtain insertion points N +1, N +2, \8230;, 2N, respectively, corresponding to

insertion points

7053, 7054 in FIG. 7. Arranging the obtained insertion points according to the sequence numbers to obtain the coordinate sequences of all the end points of the inscribed fold line: endpoint 1, insertion point 2, \ 8230;, insertion point N-1, endpoint 2, correspond to endpoint 601, insertion point 7051, insertion point 7052, insertion point 7053, insertion point 7054, endpoint 602 in fig. 7. The

broken line segments

7061, 7062 \8230, 8230and 7065 are generated by connecting the end points, and the broken line segments jointly form an inscribed broken line.

The algorithm disclosed in this embodiment can be regarded as a process of curving the straight line segment between the end point 601 and the end point 602 according to the input variable, and the result is an insertion point coordinate sequence corresponding to the inscribed polygonal line inscribed in the specific arc.

In the algorithm of the embodiment, a mode of respectively rotating the top point of the arc to two sides for taking points is adopted, and compared with a mode of rotating the top point of the arc to the opposite side for taking points, the method can reduce the length error accumulation of each broken line segment as much as possible, avoid the problem that the length of the last broken line is different from that of other broken line segments too much, and ensure the symmetry of the graph.

Fig. 8 is a schematic diagram of an effective area formed by the extension area corresponding to two base sides based on the quadrangle in fig. 1. The original quadrilateral is composed of vertex 801, vertex 802, vertex 803, vertex 804, and

straight sides

811, 812, 813, 814 of the line segments between adjacent vertices. Two extending regions extend outward from the base of the

straight sides

811 and 812, respectively.

Specifically, a series of insertion points (insertion point 821, insertion point 822, etc.) are obtained by the algorithm in the above embodiment using the length of the broken line segment of the inner polygonal line set to 20 μm and the height-to-length ratio of the circular arc set to 0.125 as input conditions. The series of insertion points are sequentially inserted between the vertex 801 and the vertex 802 and sequentially connected, whereby the straight edge 811 is curved to obtain a series of broken line segments (broken line segment 831, broken line segment 832, and the like), an inscribed broken line corresponding to the straight edge 811 is formed, and an extended region where the straight edge 811 is a base edge is determined. Similarly, a series of insertion points (insertion point 841, insertion point 842, etc.) are obtained by the algorithm in the above embodiment, and the insertion point sequence is inserted between vertex 802 and vertex 803 in sequence and connected in sequence, so that straight edge 812 is curved to obtain a series of broken line segments (broken line segment 851, broken line segment 852, etc.), and an inscribed broken line corresponding to straight edge 812 is formed. Thus, a new polygon having vertex 801, insertion points 821, 822, \8230;, vertex 802, insertion points 841, 842, \8230;, vertex 803 and vertex 804 as vertices, and

polyline segments

831, 832, \8230;,

polyline segments

851, 852, \8230;, straight edge 813 and straight edge 814 as edges is obtained.

In the new polygon generated in this embodiment, the coordinates of each vertex are known, and therefore the area of the polygon can be easily calculated from the coordinates of these vertices. And all sides are straight line segments, so that the EDA software is very easy to realize in the current general EDA software. The problems of realizability and calculation precision caused by using the circular arc are avoided.

As can be seen from fig. 8, the internal angles formed by each vertex and the two adjacent sides in the initial quadrangle are

internal angles

861, 862, 863 and 864, respectively. The

inner angles

861 and 862 are acute angles, the inner angle 863 is a right angle, and the inner angle 864 is an obtuse angle. In a resonator, the layers are generally similar in shape. When the shape of the metal layer such as the upper electrode and the lower electrode includes an acute angle, the thin film structure is easily damaged by stress during the process of manufacturing, and charges are easily accumulated at the tip when an electrical signal is turned on, thereby reducing electrostatic discharge (ESD) characteristics and power endurance of the device. When the shape of the air cavity comprises an acute angle, corrosive liquid is difficult to contact with the sacrificial material at the corner, and the sacrificial material is difficult to release completely, so that the residual of the sacrificial material is caused, the main resonance mode of the resonator is influenced, and the performance of the device is greatly reduced. And the sum of the four internal angles of the quadrangle is 360 degrees, at least one internal angle in the quadrangle with non-parallel sides is an acute angle, so that the application of the quadrangle in the design of the filter is limited.

Therefore, in some preferred embodiments, the corresponding internal angle can be optimized to an obtuse angle by the arc of the straight edge, thereby further improving the device performance.

Specifically, at least one side corresponding to the acute angle or the right angle in the polygonal area can be used as a base side for arc forming, and a proper curvature is selected, so that the inner angle corresponding to the inner connecting folding line after arc forming becomes an obtuse angle, and the performance of the device is improved.

As can be seen in fig. 8, the straight side 811 forms an angle with the corresponding broken line segment 831 of the inner fold line such that the inner angle 861 is expanded to an obtuse angle, resulting in an arched inner angle 861'. Similarly, the inner angle 862 'after being curved and the inner angle 863' after being curved are both equivalent to the obtuse angle formed by the extension of the inner polygonal line of the original quadrilateral. In the inscribed broken line, the included angle formed by adjacent broken line segments is almost close to a straight angle because of being inscribed in an arc. Therefore, the variation of the included angles also improves the performance of the resonator with the shape as the contour of the active area. And the process preparation difficulty of the obtuse angle is lower relative to the acute angle.

Fig. 9 is a schematic diagram of setting initial sampling points of the optimized polygon in fig. 8, and shows distribution of the sampling points set at the edge of the effective area. As shown in fig. 9, there are 44 sampling points, and 2 sampling points are provided on each of the broken line segments of the inscribed polygonal line obtained after the arc is performed, so as to increase the effectiveness of the sample. The leftmost point of the lower inner polyline side is the number 1 starting point 901, and the rest points are numbered in a counterclockwise sequence.

Fig. 10 is an example of the lateral resonance distance at one of the corresponding points of fig. 9, showing the lateral resonance distance at one starting point 913 on the inner polyline after the arcing, which reaches 15342.2 μm. It can be seen that the transmission path of the acoustic wave spreads almost over the entire resonator active area, which is also beneficial to increase the value of the lateral resonance distance.

Fig. 11 is a graph of the lateral resonance distance distribution of 44 sampling points corresponding to fig. 9. As can be seen from the figure, the numerical value distribution of the transverse resonance distance is about 1000-118000 micrometers, the transverse resonance distance is in a dispersed distribution shape, and the median value reaches 18257.2 micrometers. Comparing fig. 2, it can be found that the optimized polygon has an increased resonance distance median value of about 63% compared with the original quadrilateral. Also, as seen from fig. 11, there is no case where the resonance paths of adjacent points are completely equal. The optimized polygon really and effectively avoids energy superposition caused by the same transverse resonance distance, and the performance of the device can be improved.

Therefore, the scheme provided by the application can avoid the condition that multipoint resonance paths are similar, reduce energy superposition caused by the same transverse resonance distance, increase the distance of each point resonance path and improve the performance of the device. And does not include the arc line, realize easily in the design software, the parameter of the device of being convenient for calculates.

In other embodiments, the curvature of the arc circumscribing the base edge may be further increased to further increase the corresponding internal angle, which may become a reflex angle. In general, the smaller the number of original polygon sides, the smaller the average value of the corresponding original internal angle angles. To generate the reflex angle, the more the angle that needs to be expanded by the inscribed polygonal line, the larger the corresponding inscribed arc curvature needs to be set.

Fig. 12 is a schematic diagram of a polygon obtained by performing an arc process using four straight sides each having a broken line length of 20 μm and a height-to-length ratio of 0.4 as parameters, on the basis of the quadrangle shown in fig. 1. As can be seen from FIG. 12, since the height and length of the selected arc are relatively large, the four inner angles of the original quadrangle form reflex angles larger than 180 degrees at the same positions of the new polygon due to the outward protrusion of the inner polygonal line.

The distribution of the sampling points is also shown in fig. 12. The leftmost point of the edge of the lower inscribed broken line is the No. 1 starting point 1201, and the rest points are numbered in a counterclockwise sequence, so that the total number of the 29 sampling points is obtained.

Fig. 13 is an example of the lateral resonance distance at one of the points in fig. 12, showing the lateral resonance distance at one starting point 1210 on the inscribed fold line after the arc has been formed, up to 40392.4 μm. It can be seen that the transmission path of the acoustic wave extends almost over the entire resonator active area, which is also beneficial for increasing the value of the lateral resonance distance.

FIG. 14 is a schematic diagram of the distribution of the lateral resonance distances of the sampling points in FIG. 12, the lateral resonance distance of each edge sampling point is distributed in the range of 5500 μm to 180000 μm, the median value is 35186 μm, the minimum value of the distances is significantly improved compared with the foregoing embodiment, and it is shown that there is substantially no point where the resonance distance is extremely short, which is also a benefit brought by the larger curvature of the arc inscribed by the polygonal line.

In addition, the polygon of the embodiment can also improve the area utilization rate during chip layout design. The illustration is again made with the quadrilateral of fig. 1 as a comparative example.

Fig. 15 is a schematic diagram of a chip layout structure corresponding to a piezoelectric device having an active area in a generally quadrangular shape. The upper electrode 1501, the lower electrode 1502 and the air cavity 1503 are similar in shape and are quadrangular. In order to inject the etching solution to the sacrificial material under the lower electrode, the release trenches 1510 are generally led out at the vertices of the quadrangle, and the release holes 1520 are disposed at the ends of the release trenches 1510, wherein a certain distance is required from the release holes 1520 to the boundary of the lower electrode 1502. Thus, after the etching liquid enters from the release hole 1520, it can reach all positions of the resonator effective area, such as the vicinity of the apex and the central position, with the shortest distance. Since each side of the quadrangle is a straight side, a keep-out region bounded by the edge connection 1530 of the release hole 1520 is formed in the vicinity of the piezoelectric device. Other components in the chip cannot be placed in this keep-out region, thereby wasting area.

Fig. 16 is a schematic diagram of a chip layout structure corresponding to the piezoelectric device having the active region in the shape of the polygon after the arc in fig. 12. The upper electrode 1601, the lower electrode 1602 and the air cavity 1603 are similar in shape and are all polygonal after being arched. Since the reflex angle is formed at the position of the vertex of the quadrangle before the arc-formation and the outer side is formed just as a depression, the release hole 1620 may be placed just at the outer side depression of the reflex angle. Further, by appropriately setting the curvature of the arc of the inner fold line, the edge of the release groove 1610 may be made flush with the outer edge of the adjacent inner fold line as the keep-out region boundary 1630. Therefore, the area of the forbidden distribution region can be reduced to a certain extent, the effect of improving the area utilization rate of the chip layout is achieved, and the integration level of the filter chip is improved.

On the other hand, the concept of the inner polyline provided by the present application has the advantage of expanding the inner angle, so that the application of the triangle in the resonator is possible.

Fig. 17 is a schematic diagram of an effective area based on a general acute triangle, plus three extended areas corresponding to the base edges. Three sides of the original acute triangle (dotted line) are subjected to arc to obtain three corresponding sections of internal broken lines (solid lines), and the three sections of internal broken lines are connected to form an arc polygon. The length of a broken line segment of the inner polygonal line is 20 μm, the height-to-length ratio of the straight edge 1701 being curved is 0.25, the height-to-length ratio of the straight edge 1702 being curved is 0.2, and the height-to-length ratio of the straight edge 1703 being curved is 0.15. The shape contrast before and after the three-side arcing of the triangle, and the distribution of 33 sampling points on the edge can be seen in fig. 17. The first point from the left of the inner fold line after the straight edge 1701 is curved is taken as the starting point 1711 No. 1, and the other points are numbered in the counterclockwise sequence. The internal angles of the same positions after the arc treatment are changed from the original acute angle of about 60 degrees to the obtuse angle of more than 120 degrees, so that the performance of the resonator adopting the shape is improved, and the process preparation difficulty is reduced. Moreover, because the internal angles of the triangle certainly comprise at least two acute angles, the triangle is not adopted as the shape of the resonator in the design of the piezoelectric filter generally, but after three sides of the triangle are subjected to the arc treatment to form the polygon according to the application, the design by using the approximate triangle resonator becomes possible, and the layout design flexibility of the piezoelectric filter chip is greatly improved while the performance of the resonator is not reduced.

Fig. 18 is a diagram of a lateral resonance path starting from a sample point on the edge of the curved line of fig. 17, showing the lateral resonance distance of a starting point 1730 on the inscribed polygonal line after the curve is curved, which reaches 35367.4 μm. It can be seen that the lateral resonant path extends over the entire resonator active area.

FIG. 19 is a lateral resonance distance distribution diagram of the 33 sampling points in FIG. 17, in which the values of the lateral resonance distances are distributed around 1500 μm to 194000 μm in a distributed manner, and the median value reaches 33572.8 μm, thereby effectively avoiding energy superposition caused by the same lateral resonance distance.

Fig. 20 is a schematic diagram of an effective area based on a general pentagon, and an extended area corresponding to two base sides. Two sides (dotted lines) of the original pentagon are subjected to arc forming to obtain two corresponding sections of inscribed broken lines, and the two corresponding sections of inscribed broken lines are connected with three non-arc sides to form an arc-formed polygon (solid line). Wherein, the corresponding camber height-length ratio of the two base sides is 0.1, and the length of the sub-line segment is 20 μm. The shape contrast before and after the two edges are curved and the distribution of 29 sampling points on the edges can be seen in fig. 20. The first point from the left of the lower inner fold line is the starting point 2001 No. 1, and the other points are numbered in the counterclockwise order.

FIG. 21 is a diagram of a lateral resonance path with a starting point at a sample point on the inner polyline in FIG. 20, and shows that the lateral resonance distance at a starting point 2012 on the inner polyline after the arcing reaches 44454.1 μm. It can be seen that the lateral resonant path extends over the entire resonator active area.

FIG. 22 is a transverse resonance distance distribution diagram of 29 sampling points in FIG. 20, in which the numerical values of the transverse resonance distances are distributed around 500 μm to 290000 μm, and are distributed dispersedly, the median value reaches 40674.1 μm, and energy superposition caused by the same transverse resonance distance is effectively avoided.

The present application also provides an electrode of a piezoelectric device, which is used as the first electrode and/or the second electrode of the piezoelectric device described in the above embodiments to form the active region.

In some embodiments, the electrode may be a first electrode (upper electrode) of the piezoelectric device, and the shape of the electrode is the shape of the active region.

The present application also provides a design method for the piezoelectric device described in the above embodiments. The piezoelectric device comprises a first electrode, a piezoelectric layer, a second electrode, an acoustic mirror and a substrate which are sequentially superposed; the overlapping area of the first electrode, the piezoelectric layer, the second electrode and the acoustic mirror in the stacking direction forms an effective area of the piezoelectric device; the effective area comprises a polygonal area and at least one extension area connected with the polygonal area in the same plane; the extension area comprises a base edge and a plurality of fold line edges which are connected in sequence. As shown in fig. 23, the method of the present embodiment includes:

and S231, determining a polygonal area.

The shape of the polygonal area can be a common shape such as a triangle, a quadrangle, a pentagon, a hexagon and the like without limitation. However, it is understood that the larger the number of sides of the polygon, the larger the mean value of the internal angle, which may be greater than 90 ° or even close to 180 °, and the more reflex angle is easily formed after the arcing.

In some implementations, the shape of the polygonal area in the active area may be determined by a designer according to actual design requirements.

In other embodiments, the designer may also transmit the expected set positions to the device implementing the method, and the device may automatically select the corresponding shape based on the expected set position shape.

S232, determining at least one base edge from the edges of the polygonal area.

In some implementations, the side corresponding to the inner angle with the smaller angle can be preferentially selected as the base side according to the size of the selected inner angle of the polygon.

In other implementations, the base edge may also be selected in conjunction with the shape of the intended placement location.

In some scenarios, multiple piezoelectric devices may be used in series to form a filter. In this case, each of the piezoelectric devices has an input terminal and an output terminal for transmitting a signal, and the output terminal of one of the two connected piezoelectric devices is connected to the input terminal of the other piezoelectric device. In this scenario, in order to facilitate connection between the piezoelectric devices, the sides where the non-input end and the non-output end are located may be subjected to arc as base sides.

And S233, determining an arc taking the base edge as a chord according to the preset curvature.

The designer can select the corresponding curvature as the preset curvature according to the requirement.

In other implementations, some of the alternative curvatures may also be selected in combination with the shape of the intended placement location, the shape of the selected polygonal area. Specifically, after determining the corresponding circular arcs by taking the alternative curvatures as parameters, evaluating whether the corresponding circular arcs can meet the shape of the expected setting position; and determining the corresponding arc by taking the curvature with the highest shape matching degree with the expected setting position as the preset curvature.

And S234, selecting a corresponding number of insertion end points from the circular arc according to the preset number of broken lines.

The designer can select the number of the broken line segments in the inscribed broken line according to the requirement; alternatively, the length of the broken line segment in the inscribed broken line may be selected to determine the number of corresponding broken line segments. The number of the broken line segments is reduced by 1, namely the number of new end points (insertion end points) to be inserted on the circular arc. The specific manner of inserting the endpoint may refer to the embodiments corresponding to fig. 6 and fig. 7 described above.

S235, sequentially connecting the end points of the base edge and the corresponding number of the inserting end points to form a plurality of broken line edges serving as inner broken lines of the circular arc, so that the broken line edges and the base edge form an extending area, and the extending area and the polygonal area form an effective area with the area being a preset area.

And sequentially connecting each point on the circular arc to form the inscribed broken line. The non-base side of the polygonal area and the inner polyline together form the outline of the effective area.

Furthermore, the area of the effective area can be expanded or reduced in an equal proportion at the moment, and fine adjustment can be carried out, so that the requirement of the preset area is met.

In other embodiments, the shape of the generated effective area may be further adjusted to meet other design requirements by adjusting the curvature of the arc and the length of the broken line segment of the inscribed broken line.

Fig. 24 is a schematic structural diagram of a piezoelectric device design apparatus according to an embodiment of the present application, and as shown in fig. 24, a piezoelectric device design apparatus 240 according to the present embodiment includes: a basic polygon determining module 241, a base edge selecting module 242, an arc determining module 243, an insertion point selecting module 244, and an effective area adjusting module 245.

A base polygon determining module 241, configured to determine a polygon area;

a base edge selecting module 242, configured to determine at least one base edge from edges of the polygon region;

an arc determining module 243, configured to determine, according to a preset curvature, an arc with the base edge as a chord;

an insertion point selecting module 244, configured to select a corresponding number of insertion end points from the arc according to the number of preset broken lines;

the effective area adjusting module 245 is configured to sequentially connect the end points of the base edge and the corresponding number of the insertion end points to form a plurality of broken line edges as the inner-connection broken lines of the circular arc, so that the plurality of broken line edges and the base edge form the extending area, and the extending area and the polygonal area form the effective area with the area preset.

The apparatus of this embodiment may be configured to perform the method of any of the above embodiments, and the implementation principle and the technical effect are similar, which are not described herein again.

Fig. 25 is a schematic structural diagram of a piezoelectric device designing apparatus according to an embodiment of the present application, and as shown in fig. 25, the piezoelectric device designing apparatus 250 according to the embodiment may include: a memory 251 and a processor 252.

The memory 251 has stored thereon a computer program that can be loaded by the processor 252 and executed to perform the methods of the embodiments described above.

Wherein the processor 252 is coupled to the memory 251, such as via a bus.

Optionally, the electronic device 250 may also include a transceiver. It should be noted that the transceiver in practical application is not limited to one, and the structure of the electronic device 250 does not constitute a limitation to the embodiment of the present application.

The Processor 252 may be a CPU (Central Processing Unit), a general purpose Processor, a DSP (Digital Signal Processor), an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or other Programmable logic device, transistor logic, hardware components, or any combination thereof. Which may implement or execute the various illustrative logical blocks, modules, and circuits described in connection with the disclosure herein. The processor 252 may also be a combination of computing functions, e.g., comprising one or more microprocessors, DSPs, and microprocessors, among others.

A bus may include a path that carries information between the components. The bus may be a PCI (Peripheral Component Interconnect) bus, an EISA (Extended Industry Standard Architecture) bus, or the like. The bus may be divided into an address bus, a data bus, a control bus, etc. For ease of illustration, only one thick line is shown, but this does not mean that there is only one bus or one type of bus.

The Memory 251 may be, but is not limited to, a ROM (Read Only Memory) or other type of static storage device that can store static information and instructions, a RAM (Random Access Memory) or other type of dynamic storage device that can store information and instructions, an EEPROM (Electrically Erasable Programmable Read Only Memory), a CD-ROM (Compact Disc Read Only Memory) or other optical Disc storage, optical Disc storage (including Compact Disc, laser Disc, optical Disc, digital versatile Disc, blu-ray Disc, etc.), a magnetic disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer.

The memory 251 is used for storing application program codes for performing the present solution, and the processor 252 controls the execution. The processor 252 is configured to execute application program code stored in the memory 251 to implement the aspects of the embodiments of the method described above.

Wherein, the electronic device includes but is not limited to: mobile terminals such as mobile phones, notebook computers, digital broadcast receivers, PDAs (personal digital assistants), PADs (tablet computers), PMPs (portable multimedia players), in-vehicle terminals (e.g., car navigation terminals), and the like, and fixed terminals such as digital TVs, desktop computers, and the like. But also a server, etc. The electronic device shown in fig. 25 is merely an example, and should not bring any limitation to the functions and the scope of use of the embodiments of the present application.

The electronic device of this embodiment may be configured to perform the method of any of the above embodiments, and the implementation principle and the technical effect are similar, which are not described herein again.

The present application also provides a computer readable storage medium storing a computer program that can be loaded by a processor and executed to perform the method as in the above embodiments.

Those of ordinary skill in the art will understand that: all or a portion of the steps of implementing the above-described method embodiments may be performed by hardware associated with program instructions. The program may be stored in a computer-readable storage medium. When executed, the program performs steps comprising the method embodiments described above; and the aforementioned storage medium includes: various media that can store program codes, such as ROM, RAM, magnetic or optical disks.

Fig. 26 is a schematic view of a piezoelectric filter including a piezoelectric device provided in the present application. 4 series resonators S1 to S4 are connected in series between the 1 st port and the 2 nd port, one ends of parallel resonators P1 to P4 are connected to the connection point of the adjacent series resonators and the 2 nd port, respectively, the other ends of the parallel resonators P1 and P2 are grounded via an inductor L1, and the other ends of the parallel resonators P3 and P4 are grounded via an inductor L2. The parallel resonators are provided with mass loads so that the anti-resonance frequency of the parallel resonators is substantially equal to the resonance frequency of the series resonators, and a basic frequency response curve of the filter is formed.

Fig. 27 is a schematic diagram of an electronic device including a piezoelectric device as provided in the application. The electronic device is disclosed in this embodiment as a multi-mode multi-band communication device module. 100 is an antenna port responsible for wireless transmission, transceiving, and the like with the outside. 110 is a switch device on a receiving channel of a frequency band A, 113 is a switch device on a receiving channel of a frequency band B, 116 is a switch device on a transmitting channel of the frequency band B, and one end of 110, 113 and 116 is connected to 100 in common. The other end of 110 is connected to the receiving filter 120 of channel a and the transmitting

filters

122, 120 and 122 of channel a, which together form the duplexer of channel a, and are packaged on the same carrier board. The other end of 120 is connected to the receive amplifier 130 of channel a, and the other end of 130 is connected to the receive port 160 of channel a. The other end of 122 is connected to the transmit amplifier 132 of channel a, and the other end of 132 is connected to the transmit port 162 of channel a. 160. 162 are connected by wires to respective ports of a transceiver of the communication device. 113 is connected at the other end to the receive filter 124 of channel B, and the other end of the 124 is connected to the receive amplifier 134 of channel B, and the other end of 134 is connected to the receive port 164 of channel B. 116 are connected at the other end to channel B transmit filters 126, and at the other end to channel B transmit amplifiers 136, the other end of which is connected to channel B transmit port 166. 164. 166 are connected by wires to corresponding ports of the transceiver of the communication device. Each filter included in the communication module includes at least one piezoelectric device provided in the present application. The module realizes the functions of signal transmission, gating, filtering, amplification and the like between the transceiver and the antenna in the frequency band A and the frequency band B. The frequency band a is a standard FDD communication frequency band specified by the 3GPP communication protocol, such as N1, N2, N3, N5, N7, N8, etc. The frequency band B is a standard TDD communication frequency band specified by a mobile communication protocol, such as N40, N41, N77, N78, N79, and the like, and may also be a Wi-Fi communication frequency band specified by a WLAN protocol, such as Wi-Fi-2.4G, wi-Fi-5G, wi-Fi-6G, and the like.

Claims

1. A piezoelectric device, comprising: the piezoelectric layer is arranged on the first electrode, the second electrode is arranged on the second electrode, and the first electrode, the piezoelectric layer, the second electrode, the acoustic mirror and the substrate are sequentially superposed;

2. A piezoelectric device according to claim 1, wherein the length of each of the fold line sides is in the range 1 μm to 50 μm.

3. A piezoelectric device according to claim 1 or claim 2, wherein the lengths of the respective plurality of fold lines are equal.

4. A piezoelectric device according to claim 1 or 2, wherein the polygonal region comprises: triangular area, quadrilateral area, pentagonal area, hexagonal area.

5. A piezoelectric device according to claim 1 or 2, wherein an internal angle corresponding to a vertex of the polygonal region in the active area is greater than 90 °.

6. A piezoelectric device according to claim 5, wherein an internal angle corresponding to a vertex of the polygonal region in the active area is greater than 180 °.

7. An electrode for a piezoelectric device, wherein the electrode is used as a first electrode and/or a second electrode of a piezoelectric device according to any one of claims 1 to 6 to form the active region.

8. The design method of the piezoelectric device is characterized in that the piezoelectric device comprises a first electrode, a piezoelectric layer, a second electrode, an acoustic mirror and a substrate which are sequentially stacked; the overlapping area of the first electrode, the piezoelectric layer, the second electrode and the acoustic mirror in the stacking direction forms an effective area of the piezoelectric device; the effective area comprises a polygonal area and at least one extension area connected with the polygonal area in the same plane; the extension area comprises a base edge and a plurality of fold line edges which are connected in sequence; the method comprises the following steps:

determining a polygonal area;

determining at least one base edge from edges of the polygonal region;

and sequentially connecting the end points of the base edge and the corresponding number of the inserting end points to form a plurality of broken line edges serving as the inner connection broken lines of the circular arc, so that the plurality of broken line edges and the base edge form the extension area, and the extension area and the polygonal area form the effective area with the area being the preset area.

9. A piezoelectric filter, comprising: a piezoelectric device as claimed in any one of claims 1 to 6.

10. An electronic device, comprising: the piezoelectric filter of claim 9.