CN103604950A - Piezoelectric type micro acceleration sensor - Google Patents

Abstract

The invention provides a piezoelectric type micro acceleration sensor. The sensor comprises a sensitive chip and an upper glass plate and a lower glass plate. The sensitive chip adopts an annular structure which is symmetrical in structure. The sensitive chip comprises eight upper electrodes, eight lower electrodes, eight piezoelectric layers, a supporting membrane and a mass block in total. The eight lower electrodes are arranged on the supporting membrane. The eight piezoelectric layers are arranged on the lower electrodes. The eight upper electrodes are arranged on the piezoelectric layers. The mass block is suspended below the lower electrodes and fixedly connected with the supporting membrane. The mass block is suspended below the supporting membrane so that a movable part of the sensitive chip is formed. Circular rings formed by the electrodes and the piezoelectric layers respectively are concentric with the mass block. The sensitive chip and the upper glass plate and the lower glass plate are respectively connected via bonding. An inherent frequency of the piezoelectric type micro acceleration sensor is greater than 14.8KHz, and sensitivity is 0.62pC/g.

Description

A kind of piezoelectric type micro-acceleration sensor

Technical field

The invention belongs to microelectromechanical systems field, be specifically related to a kind of piezoelectric type micro-acceleration sensor, there is universal property, compared with high natural frequency and good impact property.

Background technology

Acceleration transducer all has application in a lot of different fields, as automobile, military project, space flight and aviation, consumer electronics, and the aspect such as medical, industrial.Some acceleration transducer need to be worked under the environment of very severe, as temperature, thump, electromagnetic interference (EMI), be exposed in number of chemical material.Outside the type acceleration transducer both need to can have been survived in the rugged environment processes such as impact acceleration, also want correctly to receive the signal of impact.So it is necessary to develop high safe overload, high range, high trigger sensitivity, acceleration transducer anti-interference, low-power consumption.Piezoelectric acceleration transducer because of its signal to noise ratio (S/N ratio) high, highly sensitive, response band is wide, is subject to external interference little, simple in structure, the life-span is long, and without external function device, in HI high impact application, is paid much attention to.

The principle of work of piezoelectric acceleration transducer is to utilize the piezoelectric effect of material, between upper and lower metal electrode, deposits one deck piezoelectric layer, by semi-girder or planar film structure, is connected with lower mass piece.When sensor is when forces are applied, mass can produce skew, and piezoelectric layer can deform thereupon simultaneously, and piezoelectric layer, when there is strain, will produce electric charge between upper and lower two electrodes.Utilize suitable peripheral circuit that the quantity of electric charge of generation is converted to voltage form output, according to the size of this signal, measure the size of impulsive force, by Newton second law, drawn the value of acceleration.For cantilever beam structure, impact resistance is poor, is subject to when transverse acceleration twists deformation easily being destroyed.For the application under HI high impact environment, impact resistance is very important index.

Summary of the invention

The object of the present invention is to provide a kind of piezoelectric type micro-acceleration sensor, make more than the natural frequency of sensor reaches 14kHz.For high-range acceleration transducer, impact resistance is the important parameter index of high-range acceleration transducer, and structure adopts circular configuration, can solve the strength problem under HI high impact.

The present invention is achieved by the following technical solutions.

Piezoelectric type micro-acceleration sensor of the present invention, is characterized in that, described sensor comprises sensitive chip, upper glass plates, lower glass plate; Wherein, sensitive chip contains the first top electrode, the second top electrode, the 3rd top electrode, the 4th top electrode, the 5th top electrode, the 6th top electrode, the 7th top electrode, the 8th top electrode, the first piezoelectric layer, the second piezoelectric layer, the 3rd piezoelectric layer, the 4th piezoelectric layer, the 5th piezoelectric layer, the 6th piezoelectric layer, the 7th piezoelectric layer, the 8th piezoelectric layer, the first bottom electrode, the second bottom electrode, the 3rd bottom electrode, the 4th bottom electrode, the 5th bottom electrode, the 6th bottom electrode, the 7th bottom electrode, the 8th bottom electrode, support membrane, housing, columned mass; Its annexation is that the first described piezoelectric layer, the 3rd piezoelectric layer, the 5th piezoelectric layer, the 7th piezoelectric layer and the second piezoelectric layer, the 4th piezoelectric layer, the 6th piezoelectric layer, the 8th piezoelectric layer form respectively inside and outside two annulus; The first top electrode, the 3rd top electrode, the 5th top electrode, the 7th top electrode and the second top electrode, the 4th top electrode, the 6th top electrode, the 8th top electrode form respectively inside and outside two annulus; The second bottom electrode, the 3rd bottom electrode, the 6th bottom electrode, the 7th bottom electrode and the first bottom electrode, the 4th bottom electrode, the 5th bottom electrode, the 8th bottom electrode form respectively inside and outside two annulus; The first described bottom electrode, the second bottom electrode, the 3rd bottom electrode, the 4th bottom electrode, the 5th bottom electrode, the 6th bottom electrode, the 7th bottom electrode, the 8th bottom electrode are arranged at support membrane upper surface, and are fixedly connected with support membrane upper surface; The 8th described piezoelectric layer, the 7th piezoelectric layer, the 3rd piezoelectric layer, the 4th piezoelectric layer, the second piezoelectric layer, the first piezoelectric layer, the 5th piezoelectric layer, the 6th piezoelectric layer be the corresponding upper surface that is arranged at the first bottom electrode, the second bottom electrode, the 3rd bottom electrode, the 4th bottom electrode, the 5th bottom electrode, the 6th bottom electrode, the 7th bottom electrode, the 8th bottom electrode respectively, and is fixedly connected with the upper surface of the first bottom electrode, the second bottom electrode, the 3rd bottom electrode, the 4th bottom electrode, the 5th bottom electrode, the 6th bottom electrode, the 7th bottom electrode, the 8th bottom electrode respectively; The first described top electrode, the second top electrode, the 3rd top electrode, the 4th top electrode, the 5th top electrode, the 6th top electrode, the 7th top electrode, the 8th top electrode be the corresponding upper surface that is arranged at the first piezoelectric layer, the second piezoelectric layer, the 3rd piezoelectric layer, the 4th piezoelectric layer, the 5th piezoelectric layer, the 6th piezoelectric layer, the 7th piezoelectric layer, the 8th piezoelectric layer respectively, and is fixedly connected with the upper surface of the first piezoelectric layer, the second piezoelectric layer, the 3rd piezoelectric layer, the 4th piezoelectric layer, the 5th piezoelectric layer, the 6th piezoelectric layer, the 7th piezoelectric layer, the 8th piezoelectric layer respectively.Described mass is suspended under the annulus of the second bottom electrode, the 3rd bottom electrode, the 6th bottom electrode, the 7th bottom electrode formation, and is fixedly connected with support membrane.Described support membrane is fixedly connected with housing.Described sensitive chip is connected by bonding with upper glass plates, lower glass plate.

The diameter of the annulus that the first top electrode in described sensitive chip, the 3rd top electrode, the 5th top electrode, the 7th top electrode form is identical with the diameter of the annulus that the second bottom electrode, the 3rd bottom electrode, the 6th bottom electrode, the 7th bottom electrode form; The diameter of the annulus that the second top electrode, the 4th top electrode, the 6th top electrode, the 8th top electrode form is identical with the diameter of the annulus that the first bottom electrode, the 4th bottom electrode, the 5th bottom electrode, the 8th bottom electrode form.

Described mass is coaxial setting with the annulus that the second bottom electrode, the 3rd bottom electrode, the 6th bottom electrode, the 7th bottom electrode form.

The first described piezoelectric layer, the 3rd piezoelectric layer, the 5th piezoelectric layer, the 7th piezoelectric layer and the second piezoelectric layer, the 4th piezoelectric layer, the 6th piezoelectric layer, inside and outside two annulus that the 8th piezoelectric layer forms respectively, the first top electrode, the 3rd top electrode, the 5th top electrode, the 7th top electrode and the second top electrode, the 4th top electrode, the 6th top electrode, inside and outside two annulus that the 8th top electrode forms respectively, with the second bottom electrode, the 3rd bottom electrode, the 6th bottom electrode, the 7th bottom electrode and the first bottom electrode, the 4th bottom electrode, the 5th bottom electrode, inside and outside two annulus that the 8th bottom electrode forms are respectively coaxial setting.

The outer diameter of a circle of the annulus that the first described piezoelectric layer, the 3rd piezoelectric layer, the 5th piezoelectric layer, the 7th piezoelectric layer form is greater than the outer diameter of a circle of the annulus of the first top electrode, the 3rd top electrode, the 5th top electrode, the 7th top electrode formation; The interior diameter of a circle of the annulus that the first described piezoelectric layer, the 3rd piezoelectric layer, the 5th piezoelectric layer, the 7th piezoelectric layer form is less than the interior diameter of a circle of the annulus of the first top electrode, the 3rd top electrode, the 5th top electrode, the 7th top electrode formation; The outer diameter of a circle of the annulus that the second described piezoelectric layer, the 4th piezoelectric layer, the 6th piezoelectric layer, the 8th piezoelectric layer form is greater than the outer diameter of a circle of the annulus of the second top electrode, the 4th top electrode, the 6th top electrode, the 8th top electrode formation; The interior diameter of a circle of the annulus that the second described piezoelectric layer, the 4th piezoelectric layer, the 6th piezoelectric layer, the 8th piezoelectric layer form is less than the interior diameter of a circle of the annulus of the second top electrode, the 4th top electrode, the 6th top electrode, the 8th top electrode formation.

Described mass surface diameter of a circle is greater than the interior diameter of a circle of the annulus of the second bottom electrode, the 3rd bottom electrode, the 6th bottom electrode, the 7th bottom electrode formation.

Between described top electrode, all leave interval, between bottom electrode, all leave interval, between piezoelectric layer, all leave interval.

Piezoelectric type micro-acceleration sensor of the present invention, when forces are applied, the relative matrix motion of mass causes piezoelectric layer to deform, in the time of piezoelectric material deforms, between upper/lower electrode, produce electric charge, by peripheral testing circuit, just can know the size of acceleration.

The advantage of piezoelectric type micro-acceleration sensor of the present invention is:

1. the present invention adopts cylindric mass.Owing to adopting cylindric mass, structural symmetry, is subject to the power of any direction, and piezoelectric layer all deformation can occur, thereby well solves the universal property problem of contact fuze.

2. the size of mass can be adjusted according to the needs of sensitivity and frequency response.

3. whole support membrane is a planar structure.Owing to adopting planar structure, with respect to cantilever beam structure, there is stronger impact resistance; When being subject to transverse acceleration, can not make beam fracture because of torsional deformation yet.

4. ring-type piezoelectric layer is compared with the piezoelectric layer of cantilever beam structure, has larger useful area, produces the more quantity of electric charge.

5. piezoelectric layer inside loop and outside loop shape structure can be adjusted according to the internal outside diameter size of the needs of sensitivity and frequency response, has increased the dirigibility of design.

6. the inside and outside two annulus parts of piezoelectric layer are not connected, and improve electric charge output quantity.Due to contrary to the symbol of mass radial stress from clamped end, by two regions separately, the electric charge that these two regions are produced mutually superposes rather than cancels out each other.The piezoelectric layer of same annulus is divided into four parts, is also in order to prevent that electric charge from cancelling out each other.

7. the support membrane between mass and housing is partly a planar structure, makes sensitive chip take a unit, and (its thickness is relevant with the range of sensor) can avoid the break-through of great difficulty, the process of release cantilever beam structure in technique.Therefore reproducible.

8. piezoelectric type micro-acceleration sensor of the present invention is to be bonded together and to be formed by sensitive chip and upper and lower glass plate, and this packaging technology is simple, easy to operate.

9. between sensitive chip movable structure and upper and lower cover plate, there is suitable distance, make sensitive chip have enough movement clearance on the one hand, when condition is suitable, can adjust ratio of damping on the other hand, guaranteed that like this this device working band is wider.

Accompanying drawing explanation

Fig. 1 is piezoelectric type micro-acceleration sensor exploded view of the present invention;

Fig. 2 is the sensitive chip structural representation in piezoelectric type micro-acceleration sensor of the present invention;

Fig. 3 is the sensitive chip vertical view in piezoelectric type micro-acceleration sensor of the present invention;

Fig. 4 is the sectional view along Fig. 3 A-A hatching line;

Fig. 5 is the sectional view along Fig. 3 B-B hatching line;

Fig. 6 is the sensitive chip schematic rear view in piezoelectric type micro-acceleration sensor of the present invention;

In figure, 1. the firsttop electrode 2. secondtop electrode 3. the 3rdtop electrode 4. the 4thtop electrode 5. the 5thtop electrode 6. the 6th top electrode 7. the 7th top electrode 8. the 8thtop electrode 9. firstpiezoelectric layer 10. secondpiezoelectric layer 11. the 3rdpiezoelectric layer 12. the 4thpiezoelectric layer 13. the 5thpiezoelectric layer 14. the 6thpiezoelectric layer 15. the 7thpiezoelectric layer 16. the 8th piezoelectric layer 17. first bottom electrode 18. second bottom electrode 19. the 3rd bottom electrode 20. the4th bottom electrode 21. the5th bottom electrode 22. the6th bottom electrode 23. the7th bottom electrode 24. the8th bottom electrode 25.support membrane 26.mass 27.sensitive chip 28. lower-glass 29.upper glass 30. housings.

Embodiment

Below in conjunction with accompanying drawing, the invention will be further described.

Embodiment 1

Fig. 1 is piezoelectric type micro-acceleration sensor exploded view of the present invention, Fig. 2 is the sensitive chip structural representation in piezoelectric type micro-acceleration sensor of the present invention, Fig. 3 is the sensitive chip vertical view in piezoelectric type micro-acceleration sensor of the present invention, Fig. 4 is the sectional view along Fig. 3 A-A hatching line, Fig. 5 is the sectional view along Fig. 3 B-B hatching line, and Fig. 6 is the sensitive chip schematic rear view in piezoelectric type micro-acceleration sensor of the present invention.In Fig. 1 ~ 6, piezoelectric type micro-acceleration sensor of the present invention, comprises sensitive chip 27, upper glass plates 29, lower glass plate 28, wherein, sensitive chip 27 contains the first top electrode 1, the second top electrode 2, the 3rd top electrode 3, the 4th top electrode 4, the 5th top electrode 5, the 6th top electrode 6, the 7th top electrode 7, the 8th top electrode 8, the first piezoelectric layer 9, the second piezoelectric layer 10, the 3rd piezoelectric layer 11, the 4th piezoelectric layer 12, the 5th piezoelectric layer 13, the 6th piezoelectric layer 14, the 7th piezoelectric layer 15, the 8th piezoelectric layer 16, the first bottom electrode 17, the second bottom electrode 18, the 3rd bottom electrode 19, the 4th bottom electrode 20, the 5th bottom electrode 21, the 6th bottom electrode 22, the 7th bottom electrode 23, the 8th bottom electrode 24, support membrane 25, housing 30, columned mass 26, its annexation is that described the first piezoelectric layer 9, the 3rd piezoelectric layer 11, the 5th piezoelectric layer 13, the 7th piezoelectric layer 15 form an annulus, the second piezoelectric layer 10, the 4th piezoelectric layer 12, the 6th piezoelectric layer 14, an annulus of the 8th piezoelectric layer 16 formations, the first piezoelectric layer 9, the 3rd piezoelectric layer 11, the 5th piezoelectric layer 13, the 7th piezoelectric layer 15 and the second piezoelectric layer 10, the 4th piezoelectric layer 12, the 6th piezoelectric layer 14, the 8th piezoelectric layer 16 form respectively inside and outside two annulus.Described the first top electrode 1, the 3rd top electrode 3, the 5th top electrode 5, the 7th top electrode 7 form an annulus, and the second top electrode 2, the 4th top electrode 4, the 6th top electrode 6, the 8th top electrode 8 form an annulus; The first top electrode 1, the 3rd top electrode 3, the 5th top electrode 5, the 7th top electrode 7 and the second top electrode 2, the 4th top electrode 4, the 6th top electrode 6, the 8th top electrode 8 form respectively inside and outside two annulus.Described the second bottom electrode 18, the 3rd bottom electrode 19, the 6th bottom electrode 22, the 7th bottom electrode 23 form an annulus, and the first bottom electrode 17, the 4th bottom electrode 20, the 5th bottom electrode 21, the 8th bottom electrode 24 form an annulus; The second bottom electrode 18, the 3rd bottom electrode 19, the 6th bottom electrode 22, the 7th bottom electrode 23 and the first bottom electrode 17, the 4th bottom electrode 20, the 5th bottom electrode 21, the 8th bottom electrode 24 form respectively inside and outside two annulus.Described the first bottom electrode 17, the second bottom electrode 18, the 3rd bottom electrode 19, the 4th bottom electrode 20, the 5th bottom electrode 21, the 6th bottom electrode 22, the 7th bottom electrode 23, the 8th bottom electrode 24 are arranged at support membrane 25 upper surfaces, and are fixedly connected with support membrane 25 upper surfaces, the 8th described piezoelectric layer 16, the 7th piezoelectric layer 15, the 3rd piezoelectric layer 11, the 4th piezoelectric layer 12, the second piezoelectric layer 10, the first piezoelectric layer 9, the 5th piezoelectric layer 13, the 6th piezoelectric layer 14 respectively correspondence is arranged at the first bottom electrode 17, the second bottom electrode 18, the 3rd bottom electrode 19, the 4th bottom electrode 20, the 5th bottom electrode 21, the 6th bottom electrode 22, the 7th bottom electrode 23, the upper surface of the 8th bottom electrode 24, and respectively with the first bottom electrode 17, the second bottom electrode 18, the 3rd bottom electrode 19, the 4th bottom electrode 20, the 5th bottom electrode 21, the 6th bottom electrode 22, the 7th bottom electrode 23, the upper surface of the 8th bottom electrode 24 is fixedly connected with, the first described top electrode 1, the second top electrode 2, the 3rd top electrode 3, the 4th top electrode 4, the 5th top electrode 5, the 6th top electrode 6, the 7th top electrode 7, the 8th top electrode 8 respectively correspondence is arranged at the first piezoelectric layer 9, the second piezoelectric layer 10, the 3rd piezoelectric layer 11, the 4th piezoelectric layer 12, the 5th piezoelectric layer 13, the 6th piezoelectric layer 14, the 7th piezoelectric layer 15, the upper surface of the 8th piezoelectric layer 16, and respectively with the first piezoelectric layer 9, the second piezoelectric layer 10, the 3rd piezoelectric layer 11, the 4th piezoelectric layer 12, the 5th piezoelectric layer 13, the 6th piezoelectric layer 14, the 7th piezoelectric layer 15, the upper surface of the 8th piezoelectric layer 16 is fixedly connected with, described mass 26 is suspended under the annulus of the second bottom electrode 18, the 3rd bottom electrode 19, the 6th bottom electrode 22, the 7th bottom electrode 23 formations, and is fixedly connected with support membrane 25, described support membrane 25 is fixedly connected with housing 30, described sensitive chip 27 is connected by bonding respectively with upper glass plates 29, lower glass plate 28.

The diameter of the annulus that the firsttop electrode 1 in describedsensitive chip 27, the 3rdtop electrode 3, the 5thtop electrode 5, the 7th top electrode 7 form is identical with the diameter of the annulus that the second bottom electrode 18, the 3rd bottom electrode 19, the6th bottom electrode 22, the7th bottom electrode 23 form; The diameter of the annulus that the secondtop electrode 2, the 4thtop electrode 4, the 6thtop electrode 6, the 8th top electrode 8 form is identical with the diameter of the annulus that the first bottom electrode 17, the 4th bottom electrode 20, the5th bottom electrode 21, the8th bottom electrode 24 form.

Describedmass 26 is coaxial setting with the annulus that the second bottom electrode 18, the 3rd bottom electrode 19, the6th bottom electrode 22, the7th bottom electrode 23 form.

The first describedpiezoelectric layer 9, the 3rdpiezoelectric layer 11, the 5thpiezoelectric layer 13, the 7thpiezoelectric layer 15 and the secondpiezoelectric layer 10, the 4thpiezoelectric layer 12, the 6thpiezoelectric layer 14, inside and outside two annulus that the 8thpiezoelectric layer 16 forms respectively, the firsttop electrode 1, the 3rdtop electrode 3, the 5thtop electrode 5, the 7th top electrode 7 and the secondtop electrode 2, the 4thtop electrode 4, the 6thtop electrode 6, inside and outside two annulus that the 8th top electrode 8 forms respectively, with the second bottom electrode 18, the 3rd bottom electrode 19, the6th bottom electrode 22, the7th bottom electrode 23 and the first bottom electrode 17, the 4th bottom electrode 20, the5th bottom electrode 21, inside and outside two annulus that the8th bottom electrode 24 forms are respectively coaxial setting.

The large 35 μ m of outer diameter of a circle of the annulus that the outer diameter of a circle of the annulus that described the first piezoelectric layer 9, the 3rd piezoelectric layer 11, the 5th piezoelectric layer 13, the 7th piezoelectric layer 15 forms forms than the first top electrode 1, the 3rd top electrode 3, the 5th top electrode 5, the 7th top electrode 7; The little 35 μ m of interior diameter of a circle of the annulus that the interior diameter of a circle of the annulus that described the first piezoelectric layer 9, the 3rd piezoelectric layer 11, the 5th piezoelectric layer 13, the 7th piezoelectric layer 15 forms forms than the first top electrode 1, the 3rd top electrode 3, the 5th top electrode 5, the 7th top electrode 7; The large 35 μ m of outer diameter of a circle of the annulus that the outer diameter of a circle of the annulus that described the second piezoelectric layer 10, the 4th piezoelectric layer 12, the 6th piezoelectric layer 14, the 8th piezoelectric layer 16 forms forms than the second top electrode 2, the 4th top electrode 4, the 6th top electrode 6, the 8th top electrode 8; The little 35 μ m of interior diameter of a circle of the annulus that the interior diameter of a circle of the annulus that described the second piezoelectric layer 10, the 4th piezoelectric layer 12, the 6th piezoelectric layer 14, the 8th piezoelectric layer 16 forms forms than the second top electrode 2, the 4th top electrode 4, the 6th top electrode 6, the 8th top electrode 8.

The large 25 μ m of interior diameter of a circle of the annulus that describedmass 26 upper surface diameter of a circles form than the second bottom electrode 18, the 3rd bottom electrode 19, the6th bottom electrode 22, the7th bottom electrode 23.

Between described top electrode, all leave interval, between bottom electrode, all leave interval, between piezoelectric layer, all leave interval.

Between the first describedtop electrode 1, the 3rdtop electrode 3, the 5thtop electrode 5, the 7th top electrode 7, be spaced apart 60 μ m, between the secondtop electrode 2, the 4thtop electrode 4, the 6thtop electrode 6, the 8th top electrode 8, be spaced apart 60 μ m; Between the second described bottom electrode 18, the 3rd bottom electrode 19, the6th bottom electrode 22, the7th bottom electrode 23, be spaced apart 60 μ m, between the first bottom electrode 17, the 4th bottom electrode 20, the5th bottom electrode 21, the8th bottom electrode 24, be spaced apart 60 μ m.

Between the first describedpiezoelectric layer 9, the 3rdpiezoelectric layer 11, the 5thpiezoelectric layer 13, the 7thpiezoelectric layer 15, be spaced apart 25 μ m, between the secondpiezoelectric layer 10, the 4thpiezoelectric layer 12, the 6thpiezoelectric layer 14, the 8thpiezoelectric layer 16, be spaced apart 25 μ m.

Between the annulus that the annulus that described the firstpiezoelectric layer 9, the 3rdpiezoelectric layer 11, the 5thpiezoelectric layer 13, the 7thpiezoelectric layer 15 forms and the secondpiezoelectric layer 10, the 4thpiezoelectric layer 12, the 6thpiezoelectric layer 14, the 8thpiezoelectric layer 16 form, be spaced apart 55 μ m.

Between the annulus that the annulus that described the firsttop electrode 1, the 3rdtop electrode 3, the 5thtop electrode 5, the 7th top electrode 7 forms and the secondtop electrode 2, the 4thtop electrode 4, the 6thtop electrode 6, the 8th top electrode 8 form, be spaced apart 90 μ m.

Between the annulus that the annulus that described the second bottom electrode 18, the 3rd bottom electrode 19, the6th bottom electrode 22, the7th bottom electrode 23 forms and the first bottom electrode 17, the 4th bottom electrode 20, the5th bottom electrode 21, the8th bottom electrode 24 form, be spaced apart 90 μ m.

Distance between described the firsttop electrode 1, the secondtop electrode 2, the 3rdtop electrode 3, the 4thtop electrode 4, the 5thtop electrode 5, the 6thtop electrode 6, the 7th top electrode 7, the 8th top electrode 8 andupper glass plates 29 is 80 μ m; The lower surface of describedmass 26 and the distance betweenlower glass plate 28 are 90 μ m.Make sensitive chip have enough movement clearance on the one hand, when condition is suitable, can adjust ratio of damping on the other hand.

In the present embodiment, sensitive chip length is 1800 μ m, and width is 1800 μ m, and thickness is 310 μ m; Mass upper surface circular diameter is 305 μ m, and thickness is 310 μ m; Housing inner circular diameter is 995 μ m, and thickness is 310 μ m; Support membrane thickness is 10 μ m.Sensor natural frequency of the present invention is about 15.7 kHz, the about 0.62pC/g of sensitivity.

Embodiment 2

The present embodiment is identical with the structure of embodiment 1, difference is that the outer diameter of a circle of the annulus that the first described piezoelectric layer, the 3rd piezoelectric layer, the 5th piezoelectric layer, the 7th piezoelectric layer form is than the large 45 μ m of outer diameter of a circle of the annulus of the first top electrode, the 3rd top electrode, the 5th top electrode, the 7th top electrode formation; The little 45 μ m of interior diameter of a circle of the annulus that the interior diameter of a circle of the annulus that the first described piezoelectric layer, the 3rd piezoelectric layer, the 5th piezoelectric layer, the 7th piezoelectric layer form forms than the first top electrode, the 3rd top electrode, the 5th top electrode, the 7th top electrode; The large 45 μ m of outer diameter of a circle of the annulus that the outer diameter of a circle of the annulus that the second described piezoelectric layer, the 4th piezoelectric layer, the 6th piezoelectric layer, the 8th piezoelectric layer form forms than the second top electrode, the 4th top electrode, the 6th top electrode, the 8th top electrode; The little 45 μ m of interior diameter of a circle of the annulus that the interior diameter of a circle of the annulus that the second described piezoelectric layer, the 4th piezoelectric layer, the 6th piezoelectric layer, the 8th piezoelectric layer form forms than the second top electrode, the 4th top electrode, the 6th top electrode, the 8th top electrode; The large 15 μ m of interior diameter of a circle of the annulus that mass upper surface diameter of a circle forms than the second bottom electrode, the 3rd bottom electrode, the 6th bottom electrode, the 7th bottom electrode; Between the first top electrode, the 3rd top electrode, the 5th top electrode, the 7th top electrode, be spaced apart 65 μ m, between the second top electrode, the 4th top electrode, the 6th top electrode, the 8th top electrode, be spaced apart 65 μ m; Between the second described bottom electrode, the 3rd bottom electrode, the 6th bottom electrode, the 7th bottom electrode, be spaced apart 65 μ m, between the first bottom electrode, the 4th bottom electrode, the 5th bottom electrode, the 8th bottom electrode, be spaced apart 65 μ m; Between the first piezoelectric layer, the 3rd piezoelectric layer, the 5th piezoelectric layer, the 7th piezoelectric layer, be spaced apart 20 μ m, between the second piezoelectric layer, the 4th piezoelectric layer, the 6th piezoelectric layer, the 8th piezoelectric layer, be spaced apart 20 μ m; Between the annulus that the annulus that the first piezoelectric layer, the 3rd piezoelectric layer, the 5th piezoelectric layer, the 7th piezoelectric layer form and the second piezoelectric layer, the 4th piezoelectric layer, the 6th piezoelectric layer, the 8th piezoelectric layer form, be spaced apart 50 μ m; Between the annulus that the annulus that the first top electrode, the 3rd top electrode, the 5th top electrode, the 7th top electrode form and the second top electrode, the 4th top electrode, the 6th top electrode, the 8th top electrode form, be spaced apart 95 μ m; Between the annulus that the annulus that the second bottom electrode, the 3rd bottom electrode, the 6th bottom electrode, the 7th bottom electrode form and the first bottom electrode, the 4th bottom electrode, the 5th bottom electrode, the 8th bottom electrode form, be spaced apart 95 μ m; Distance between the first top electrode, the second top electrode, the 3rd top electrode, the 4th top electrode, the 5th top electrode, the 6th top electrode, the 7th top electrode, the 8th top electrode and upper glass plates is 100 μ m; The lower surface of described mass and the distance between lower glass plate are 110 μ m; Mass upper surface circular diameter is 300 μ m; Housing inner circular diameter is 1000 μ m; Support membrane thickness is 50 μ m.Sensor natural frequency of the present invention is about 19.8kHz, the about 0.45pC/g of sensitivity.

Embodiment 3

The present embodiment is identical with the structure of embodiment 1, difference is that the outer diameter of a circle of the annulus that the first described piezoelectric layer, the 3rd piezoelectric layer, the 5th piezoelectric layer, the 7th piezoelectric layer form is than the large 40 μ m of outer diameter of a circle of the annulus of the first top electrode, the 3rd top electrode, the 5th top electrode, the 7th top electrode formation; The little 40 μ m of interior diameter of a circle of the annulus that the interior diameter of a circle of the annulus that the first described piezoelectric layer, the 3rd piezoelectric layer, the 5th piezoelectric layer, the 7th piezoelectric layer form forms than the first top electrode, the 3rd top electrode, the 5th top electrode, the 7th top electrode; The large 40 μ m of outer diameter of a circle of the annulus that the outer diameter of a circle of the annulus that the second described piezoelectric layer, the 4th piezoelectric layer, the 6th piezoelectric layer, the 8th piezoelectric layer form forms than the second top electrode, the 4th top electrode, the 6th top electrode, the 8th top electrode; The little 40 μ m of interior diameter of a circle of the annulus that the interior diameter of a circle of the annulus that the second described piezoelectric layer, the 4th piezoelectric layer, the 6th piezoelectric layer, the 8th piezoelectric layer form forms than the second top electrode, the 4th top electrode, the 6th top electrode, the 8th top electrode; The large 21 μ m of interior diameter of a circle of the annulus that mass upper surface diameter of a circle forms than the second bottom electrode, the 3rd bottom electrode, the 6th bottom electrode, the 7th bottom electrode; Between the first top electrode, the 3rd top electrode, the 5th top electrode, the 7th top electrode, be spaced apart 63 μ m, between the second top electrode, the 4th top electrode, the 6th top electrode, the 8th top electrode, be spaced apart 63 μ m; Between the second described bottom electrode, the 3rd bottom electrode, the 6th bottom electrode, the 7th bottom electrode, be spaced apart 63 μ m, between the first bottom electrode, the 4th bottom electrode, the 5th bottom electrode, the 8th bottom electrode, be spaced apart 63 μ m; Between the first piezoelectric layer, the 3rd piezoelectric layer, the 5th piezoelectric layer, the 7th piezoelectric layer, be spaced apart 23 μ m, between the second piezoelectric layer, the 4th piezoelectric layer, the 6th piezoelectric layer, the 8th piezoelectric layer, be spaced apart 23 μ m; Between the annulus that the annulus that the first piezoelectric layer, the 3rd piezoelectric layer, the 5th piezoelectric layer, the 7th piezoelectric layer form and the second piezoelectric layer, the 4th piezoelectric layer, the 6th piezoelectric layer, the 8th piezoelectric layer form, be spaced apart 53 μ m; Between the annulus that the annulus that the first top electrode, the 3rd top electrode, the 5th top electrode, the 7th top electrode form and the second top electrode, the 4th top electrode, the 6th top electrode, the 8th top electrode form, be spaced apart 93 μ m; Between the annulus that the annulus that the second bottom electrode, the 3rd bottom electrode, the 6th bottom electrode, the 7th bottom electrode form and the first bottom electrode, the 4th bottom electrode, the 5th bottom electrode, the 8th bottom electrode form, be spaced apart 93 μ m; Distance between the first top electrode, the second top electrode, the 3rd top electrode, the 4th top electrode, the 5th top electrode, the 6th top electrode, the 7th top electrode, the 8th top electrode and upper glass plates is 90 μ m; The lower surface of described mass and the distance between lower glass plate are 100 μ m; Mass upper surface circular diameter is 304 μ m; Housing inner circular diameter is 996 μ m; Support membrane thickness is 26 μ m.Sensor natural frequency of the present invention is about 16.2kHz, the about 0.56pC/g of sensitivity.

The present invention is absolutely not only confined to embodiment.

Claims (6)

1. a piezoelectric type micro-acceleration sensor, is characterized in that: described sensor comprises sensitive chip (27), upper glass plates (29), lower glass plate (28), wherein, sensitive chip (27) contains the first top electrode (1), the second top electrode (2), the 3rd top electrode (3), the 4th top electrode (4), the 5th top electrode (5), the 6th top electrode (6), the 7th top electrode (7), the 8th top electrode (8), the first piezoelectric layer (9), the second piezoelectric layer (10), the 3rd piezoelectric layer (11), the 4th piezoelectric layer (12), the 5th piezoelectric layer (13), the 6th piezoelectric layer (14), the 7th piezoelectric layer (15), the 8th piezoelectric layer (16), the first bottom electrode (17), the second bottom electrode (18), the 3rd bottom electrode (19), the 4th bottom electrode (20), the 5th bottom electrode (21), the 6th bottom electrode (22), the 7th bottom electrode (23), the 8th bottom electrode (24), support membrane (25), housing (30), columned mass (26), its annexation is that described the first piezoelectric layer (9), the 3rd piezoelectric layer (11), the 5th piezoelectric layer (13), the 7th piezoelectric layer (15) form respectively inside and outside two annulus with the second piezoelectric layer (10), the 4th piezoelectric layer (12), the 6th piezoelectric layer (14), the 8th piezoelectric layer (16), the first top electrode (1), the 3rd top electrode (3), the 5th top electrode (5), the 7th top electrode (7) form respectively inside and outside two annulus with the second top electrode (2), the 4th top electrode (4), the 6th top electrode (6), the 8th top electrode (8), the second bottom electrode (18), the 3rd bottom electrode (19), the 6th bottom electrode (22), the 7th bottom electrode (23) form respectively inside and outside two annulus with the first bottom electrode (17), the 4th bottom electrode (20), the 5th bottom electrode (21), the 8th bottom electrode (24), described the first bottom electrode (17), the second bottom electrode (18), the 3rd bottom electrode (19), the 4th bottom electrode (20), the 5th bottom electrode (21), the 6th bottom electrode (22), the 7th bottom electrode (23), the 8th bottom electrode (24) are arranged at support membrane (25) upper surface, and are fixedly connected with support membrane (25) upper surface, the 8th described piezoelectric layer (16), the 7th piezoelectric layer (15), the 3rd piezoelectric layer (11), the 4th piezoelectric layer (12), the second piezoelectric layer (10), the first piezoelectric layer (9), the 5th piezoelectric layer (13), the 6th piezoelectric layer (14) respectively correspondence is arranged at the first bottom electrode (17), the second bottom electrode (18), the 3rd bottom electrode (19), the 4th bottom electrode (20), the 5th bottom electrode (21), the 6th bottom electrode (22), the 7th bottom electrode (23), the upper surface of the 8th bottom electrode (24), and respectively with the first bottom electrode (17), the second bottom electrode (18), the 3rd bottom electrode (19), the 4th bottom electrode (20), the 5th bottom electrode (21), the 6th bottom electrode (22), the 7th bottom electrode (23), the upper surface of the 8th bottom electrode (24) is fixedly connected with, described the first top electrode (1), the second top electrode (2), the 3rd top electrode (3), the 4th top electrode (4), the 5th top electrode (5), the 6th top electrode (6), the 7th top electrode (7), the 8th top electrode (8) respectively correspondence is arranged at the first piezoelectric layer (9), the second piezoelectric layer (10), the 3rd piezoelectric layer (11), the 4th piezoelectric layer (12), the 5th piezoelectric layer (13), the 6th piezoelectric layer (14), the 7th piezoelectric layer (15), the upper surface of the 8th piezoelectric layer (16), and respectively with the first piezoelectric layer (9), the second piezoelectric layer (10), the 3rd piezoelectric layer (11), the 4th piezoelectric layer (12), the 5th piezoelectric layer (13), the 6th piezoelectric layer (14), the 7th piezoelectric layer (15), the upper surface of the 8th piezoelectric layer (16) is fixedly connected with, described mass (26) is suspended under the annulus of the second bottom electrode (18), the 3rd bottom electrode (19), the 6th bottom electrode (22), the 7th bottom electrode (23) formation, and is fixedly connected with support membrane (25), described support membrane (25) is fixedly connected with housing (30), described sensitive chip (27) is connected by bonding respectively with upper glass plates (29), lower glass plate (28).

2. according to the piezoelectric type micro-acceleration sensor described in claim l, it is characterized in that: the diameter of the annulus that the first top electrode (1) in described sensitive chip (27), the 3rd top electrode (3), the 5th top electrode (5), the 7th top electrode (7) form is identical with the diameter of the annulus that the second bottom electrode (18), the 3rd bottom electrode (19), the 6th bottom electrode (22), the 7th bottom electrode (23) form; The diameter of the annulus that the second top electrode (2), the 4th top electrode (4), the 6th top electrode (6), the 8th top electrode (8) form is identical with the diameter of the annulus that the first bottom electrode (17), the 4th bottom electrode (20), the 5th bottom electrode (21), the 8th bottom electrode (24) form.

3. piezoelectric type micro-acceleration sensor according to claim 1, is characterized in that: described mass (26) is coaxial setting with the annulus that the second bottom electrode (18), the 3rd bottom electrode (19), the 6th bottom electrode (22), the 7th bottom electrode (23) form.

4. according to the piezoelectric type micro-acceleration sensor described in claim l, it is characterized in that: described the first piezoelectric layer (9), the 3rd piezoelectric layer (11), the 5th piezoelectric layer (13), the 7th piezoelectric layer (15) and the second piezoelectric layer (10), the 4th piezoelectric layer (12), the 6th piezoelectric layer (14), inside and outside two annulus that the 8th piezoelectric layer (16) forms respectively, described the first top electrode (1), the 3rd top electrode (3), the 5th top electrode (5), the 7th top electrode (7) and the second top electrode (2), the 4th top electrode (4), the 6th top electrode (6), inside and outside two annulus that the 8th top electrode (8) forms respectively, described the second bottom electrode (18), the 3rd bottom electrode (19), the 6th bottom electrode (22), the 7th bottom electrode (23) and the first bottom electrode (17), the 4th bottom electrode (20), the 5th bottom electrode (21), inside and outside two annulus that the 8th bottom electrode (24) forms are respectively coaxial setting.

5. piezoelectric type micro-acceleration sensor according to claim 1, is characterized in that: the outer diameter of a circle of the annulus that described the first piezoelectric layer (9), the 3rd piezoelectric layer (11), the 5th piezoelectric layer (13), the 7th piezoelectric layer (15) form is greater than the outer diameter of a circle of the annulus of the first top electrode (1), the 3rd top electrode (3), the 5th top electrode (5), the 7th top electrode (7) formation; The interior diameter of a circle of the annulus that described the first piezoelectric layer (9), the 3rd piezoelectric layer (11), the 5th piezoelectric layer (13), the 7th piezoelectric layer (15) form is less than the interior diameter of a circle of the annulus of the first top electrode (1), the 3rd top electrode (3), the 5th top electrode (5), the 7th top electrode (7) formation; The outer diameter of a circle of the annulus that described the second piezoelectric layer (10), the 4th piezoelectric layer (12), the 6th piezoelectric layer (14), the 8th piezoelectric layer (16) form is greater than the outer diameter of a circle of the annulus of the second top electrode (2), the 4th top electrode (4), the 6th top electrode (6), the 8th top electrode (8) formation; The interior diameter of a circle of the annulus that described the second piezoelectric layer (10), the 4th piezoelectric layer (12), the 6th piezoelectric layer (14), the 8th piezoelectric layer (16) form is less than the interior diameter of a circle of the annulus of the second top electrode (2), the 4th top electrode (4), the 6th top electrode (6), the 8th top electrode (8) formation.

6. according to the piezoelectric type micro-acceleration sensor described in claim l, it is characterized in that: the surperficial diameter of a circle of described mass (26) is greater than the interior diameter of a circle of the annulus of the second bottom electrode (18), the 3rd bottom electrode (19), the 6th bottom electrode (22), the 7th bottom electrode (23) formation.

Images