CN101834065B - Variable-area capacitive structure capable of adjusting elasticity coefficient of micro mechanical device - Google Patents

Abstract

The invention discloses a variable-area capacitive structure capable of adjusting the elasticity coefficient of a micro mechanical device. In each unit capacitor, the positive surface of a moveable electrode is parallel to that of a fixed electrode. The variable-area capacitive structure is characterized in that: the positive surface of the moveable electrode is rectangular, and the positive surface of the fixed electrode is triangular or zigzag, or the positive surface of the moveable electrode is triangular or zigzag, and the positive surface of the fixed electrode is rectangular; and the triangular positive surface is only overlapped with a long edge of the rectangular positive surface. The variable-area capacitive structure overcomes the defect that the elasticity coefficient in the micro mechanical device with the conventional variable-area capacitive structure cannot be adjusted, can adjust the total elasticity coefficient of the micro mechanical device in a corresponding direction by adjusting the voltage difference between the unit fixed electrode and the unit moveable electrode, and improves the design flexibility of a micro mechanical sensor.

Description

A kind of variable-area capacitive structure of scalable elasticity coefficient of micro mechanical device

Technical field

The present invention relates to variable-area capacitive structure, particularly be used for the variable-area capacitive structure of micromechanical gyro and micro-mechanical accelerometer, belong to the micro mechanical sensor field.

Background technology

In the micro mechanical sensor field; Like micromechanical gyro and micro-mechanical accelerometer; Micromechanical gyro is to be used for the transducer of measured angular speed and angular displacement, and micro-mechanical accelerometer is to be used for the transducer of Measuring Object acceleration, and the both can equivalence be the spring-mass block system; The coefficient of elasticity of spring is a physical quantity crucial in the device, and it all has direct relation to the resonance frequency and the sensitivity of device.

Through the research of decades, the micro mechanical sensor development with regard to its type of detection, mainly contains pressure resistance type, condenser type, resonant mode, tunnel type etc. rapidly.Wherein condenser type is because its response is fast, makes the main flow that advantage such as simple has become current design.Capacitive micro mechanical sensor has and becomes two types of space type capacitance structure and variable area formula capacitance structures; Because application change space type capacitance structure is regulated the coefficient of elasticity of device and is widely used in the micro mechanical sensor field; Make to become the space type structure and become the main flow in the design, and the capacitance structure of variable area formula fails always to realize that the coefficient of elasticity to device regulates.

Summary of the invention

Technical problem to be solved by this invention provides a kind of variable-area capacitive structure of scalable elasticity coefficient of micro mechanical device.

Inventive concept of the present invention is: because the unit movable electrode of traditional variable area formula capacitance structure and the front surface of fixed electrode all are rectangle, never realize the adjusting to the coefficient of elasticity of micro mechanical device.The present invention regulates the coefficient of elasticity of micro mechanical device for realizing; Under the constant prerequisite of the spacing of the front surface of and unit movable electrode parallel with the front surface of unit fixed electrode and the front surface of unit fixed electrode at the front surface of holding unit movable electrode; The front surface shape of unit movable electrode still is rectangle through changing the shape of the front surface of unit fixed electrode into triangle or zigzag by traditional rectangular; Perhaps change the shape of the front surface of unit movable electrode into triangle or zigzag by traditional rectangular and the front surface shape of unit fixed electrode still is rectangle; And make the front surface of unit movable electrode and the front surface of unit fixed electrode form overlapping, between unit fixed electrode and unit movable electrode, apply a voltage, can introduce an equivalent coefficient of elasticity with certain characteristic; This equivalence coefficient of elasticity is a constant; Both can be positive number, also can be negative, and make total coefficient of elasticity increase or reduce.

The present invention solves the technical scheme that its technical problem takes: the variable-area capacitive structure of this scalable elasticity coefficient of micro mechanical device; In each cell capacitance; The front surface of movable electrode and the front surface of fixed electrode are parallel to each other; Wherein, the front surface of said movable electrode is that the front surface of rectangle and fixed electrode is triangle or zigzag, and perhaps the front surface of said movable electrode is that the front surface of triangle or zigzag and fixed electrode is a rectangle; Said triangle front surface only overlaps with the long limit of of said rectangle front surface, and said zigzag sawtooth only overlaps with a long limit of said rectangle front surface.

Further, the sawtooth of zigzag front surface according to the invention is a triangle.

Further, the sawtooth of zigzag front surface according to the invention is that the overlapping part of trapezoidal and said trapezoidal sawtooth and said rectangle front surface is triangular in shape.

Further, the sawtooth of zigzag front surface according to the invention is that the overlapping of trapezoidal and said trapezoidal sawtooth and said rectangle front surface partly is trapezoidal, and the base of the said trapezoidal part that overlaps is parallel with the long limit of said rectangle front surface.

Elasticity coefficient of micro mechanical device is regulated compared with adopt becoming the spacing capacitance structure, the present invention has the following advantages:

1. utilize the present invention to carry out coefficient of elasticity and regulate, the equivalent elastic coefficient of introducing both can be positive number, also can be negative, can design neatly as required.

2. utilize the present invention to carry out coefficient of elasticity and regulate, when and voltage difference unit fixed electrode and unit movable electrode definite with number was definite value at the structural parameters of electric capacity, the equivalent elastic coefficient of introducing was a constant.

3. the voltage extent through regulon fixed electrode and unit movable electrode is scalable micro mechanical device total coefficient of elasticity on respective direction.

Description of drawings

Fig. 1 is the first kind monolateral electric capacity vertical view of the unit fixed electrode of variable-area capacitive structure of the present invention when being triangle;

Fig. 2 is the second kind monolateral electric capacity vertical view of the unit fixed electrode of variable-area capacitive structure of the present invention when being triangle;

Fig. 3 is the unit fixed electrode of variable-area capacitive structure of the present invention the third monolateral electric capacity vertical view when being triangle;

Fig. 4 is the four kind monolateral electric capacity vertical view of the unit fixed electrode of variable-area capacitive structure of the present invention when being triangle;

Fig. 5 is the first kind differential capacitance vertical view of the unit fixed electrode of variable-area capacitive structure of the present invention when being triangle;

Fig. 6 is the second kind differential capacitance vertical view of the unit fixed electrode of variable-area capacitive structure of the present invention when being triangle;

Fig. 7 is the unit fixed electrode of variable-area capacitive structure of the present invention the third differential capacitance vertical view when being triangle;

Fig. 8 is the four kind differential capacitance vertical view of the unit fixed electrode of variable-area capacitive structure of the present invention when being triangle;

Fig. 9 is a variable-area capacitive structure of the present invention at its unit fixed electrode is zigzag and each sawtooth first kind of differential capacitance vertical view when being triangle;

Figure 10 is a variable-area capacitive structure of the present invention at its unit fixed electrode is zigzag and each sawtooth second kind of differential capacitance vertical view when being triangle;

Figure 11 is a variable-area capacitive structure of the present invention at its unit movable electrode is zigzag and each sawtooth first kind of structure vertical view when being trapezoidal;

Figure 12 is a variable-area capacitive structure of the present invention at its unit movable electrode is zigzag and each sawtooth second kind of structure vertical view when being trapezoidal;

Figure 13 is the differential configuration generalized section of variable-area capacitive structure of the present invention.

Among the figure: 1. unit movable electrode, 2. unit fixed electrode, the width of a. rectangular element movable electrode; B. the length of rectangular element movable electrode, the length on fixed electrode base, c. right-angled triangle unit, the height of d. right-angled triangle unit fixed electrode; H. the spacing of unit movable electrode and unit fixed electrode; E. the initial overlapping width of unit movable electrode and unit fixed electrode, the overlapping area of s. unit movable electrode and unit fixed electrode, the displacement of x. unit movable electrode; M. the base length of triangular element fixed electrode, the height of f. triangular element fixed electrode.

Embodiment

Like Fig. 1 to the of the present invention various forms of variable-area capacitive structures shown in Figure 13; In each cell capacitance; The front surface of unit movable electrode 1 be meant with unit fixed electrode 2 over against the surface, the front surface of unit fixed electrode 2 be meant with unit movable electrode 1 over against the surface.The front surface of the front surface of each unit movable electrode 1 and unit fixed electrode 2 is parallel to each other.

Wherein, to shown in Figure 8, the front surface of unit movable electrode 1 is a rectangle like Fig. 1, and when the front surface of unit fixed electrode 2 was triangle, the triangle front surface of unit fixed electrode 2 only overlapped with a long limit of the rectangle front surface of unit movable electrode 1; When the front surface of unit fixed electrode 2 was zigzag, like Fig. 9, shown in 10, each sawtooth was a triangle, and each sawtooth only overlaps with wherein long limit of the rectangle front surface of unit movable electrode 1.

As shown in Figure 1; The front surface of unit fixed electrode 2 is triangle and only overlaps with a long limit of the rectangle front surface of unit movable electrode 1 and form leg-of-mutton overlapping region; In addition, this edge of triangular element fixed electrode 2 limit and triangular element fixed electrode 2 parallel with the long limit of rectangular element movable electrode 1 is outside overlapping region.Unit fixed electrode 2 is V with the voltage difference of unit movable electrode 1, and the length on triangular element fixed electrode 2 bases is m, and the height of triangular element fixed electrode 2 is f, and unit movable electrode 1 is x along the displacement of X-direction.Visible by Fig. 1; The overlapping part of unit movable electrode 1 and unit fixed electrode 2 be shaped as triangle; The area of overlapping region is s; After unit movable electrode 1 produces displacement x along X axle positive direction, according to leg-of-mutton area computing formula s=base length * highly/2, the area s that can get the overlapping region of unit movable electrode 1 and unit fixed electrode 2 is:

$S=\frac{1}{2}\·\frac{m}{f}\·(e-x)\·(e-x)$

Can obtain capacitance size according to the capacity plate antenna formula is:

$C=\mathrm{\ξ}\·\frac{S}{h}=\frac{\mathrm{\ξ}}{h}\·\frac{1}{2}\·\frac{m}{f}\·(e-x)\·(e-x)$

Obtain tangential electrostatic force size according to tangential electrostatic force formula, promptly the electrostatic force size on X-direction is:

$F_x=\frac{1}{2}\&CenterDot;\frac{\mathrm{dC}}{\mathrm{dx}}\&CenterDot;{\mathrm{<figure-callout\; id="2"\; label="V"\; filenames="HSA00000087850600011.png,HSA00000087850600012.png"\; state="\{\{state\}\}">V</figure-callout>}}^2=\frac{1}{2}\&CenterDot;{\mathrm{<figure-callout\; id="2"\; label="V"\; filenames="HSA00000087850600011.png,HSA00000087850600012.png"\; state="\{\{state\}\}">V</figure-callout>}}^2=\frac{\mathrm{\&xi;}}{h}\&CenterDot;\frac{\mathrm{dS}}{\mathrm{dx}}$

The equivalent elastic coefficient that finally obtains on X-direction is:

$k_x=-\frac{{\mathrm{dF}}_x}{\mathrm{dx}}=-\frac{1}{2}\&CenterDot;{\mathrm{<figure-callout\; id="2"\; label="V"\; filenames="HSA00000087850600011.png,HSA00000087850600012.png"\; state="\{\{state\}\}">V</figure-callout>}}^2\&CenterDot;\frac{\mathrm{\&xi;}}{h}\&CenterDot;\frac{m}{f}$

For another shown in Figure 2, the front surface of unit fixed electrode 2 is triangle and only overlaps with a long limit of the rectangle front surface of unit movable electrode 1.And this edge of a limit of triangular element fixed electrode 2 and triangular element fixed electrode 2 parallel with the long limit of rectangular element movable electrode 1 and rectangular element movable electrode 1 overlap.At this moment, being shaped as of the overlapping of unit movable electrode 1 and unit fixed electrode 2 part is trapezoidal, and the area of trapezoidal overlapping region is s.According to trapezoidal area computing formula: s=(the upper base length+length of going to the bottom) * highly/2, the area s that obtains the overlapping region of unit movable electrode 1 and unit fixed electrode 2 is:

$S=\frac{1}{2}\&CenterDot;[m+\frac{f-(e-x)}{f}\&CenterDot;m]\&CenterDot;(e-x)$

Can obtain capacitance size according to the capacity plate antenna formula is:

$C=\mathrm{\&xi;}\&CenterDot;\frac{S}{h}=\frac{\mathrm{\&xi;}}{h}\&CenterDot;S=\frac{\mathrm{\&xi;}}{h}\&CenterDot;\frac{1}{2}\&CenterDot;[m+\frac{f-(e-x)}{f}\&CenterDot;m]\&CenterDot;(e-x)$

Obtain tangential electrostatic force size, the i.e. size of electrostatic force on X-direction according to tangential electrostatic force formula $F_x=\frac{1}{2}\&CenterDot;\frac{\mathrm{DC}}{\mathrm{Dx}}\&CenterDot;{\mathrm{<figure-callout\; id="2"\; label="V"\; filenames="HSA00000087850600011.png,HSA00000087850600012.png"\; state="\{\{state\}\}">V</figure-callout>}}^2=\frac{1}{2}\&CenterDot;{\mathrm{<figure-callout\; id="2"\; label="V"\; filenames="HSA00000087850600011.png,HSA00000087850600012.png"\; state="\{\{state\}\}">V</figure-callout>}}^2\&CenterDot;\frac{\mathrm{\&xi;}}{h}\&CenterDot;\frac{\mathrm{DS}}{\mathrm{Dx}}$ For:

The equivalent elastic coefficient that finally obtains on X-direction is:

$k_x=-\frac{{\mathrm{dF}}_x}{\mathrm{dx}}=\frac{1}{2}\&CenterDot;{\mathrm{<figure-callout\; id="2"\; label="V"\; filenames="HSA00000087850600011.png,HSA00000087850600012.png"\; state="\{\{state\}\}">V</figure-callout>}}^2\&CenterDot;\frac{\mathrm{\&xi;}}{h}\&CenterDot;\frac{m}{f}$

Be convenient explanation technical scheme of the present invention; Below the width a of hypothesis rectangular element movable electrode 1 is 10um; The length b of rectangular element movable electrode 1 is 2100um, and the length m on triangular element fixed electrode 2 bases is 2000um, and the height f of triangular element fixed electrode 2 is 10um; Unit movable electrode 1 is 1.5um with the spacing h of unit fixed electrode 2, and unit fixed electrode 2 is 15V with the voltage difference V of unit movable electrode 1.Under the situation as shown in Figure 1, the equivalent elastic coefficient of introducing is-0.1328N/m that this equivalence coefficient of elasticity is for bearing and being constant; Under the situation as shown in Figure 2, the equivalent elastic coefficient of introducing is 0.1328N/m, and the equivalent elastic coefficient that should introduce is for just and be constant.

As shown in Figure 3; The front surface of unit fixed electrode 2 is right-angled triangle and only overlaps with a long limit of the rectangle front surface of unit movable electrode 1; A right-angle side of right-angled triangle unit fixed electrode 2 is parallel with the long limit of the rectangle front surface of unit movable electrode 1, and the right angle of right-angled triangle unit fixed electrode 2 is positioned at outside the overlapping region of unit movable electrode 1 and unit fixed electrode 2.Unit fixed electrode 2 is V with the voltage difference of unit movable electrode 1; The displacement of unit movable electrode 1 is x, and x is the displacement of unit movable electrode 1 on X-direction, just both can be, and also can be negative; Unit movable electrode 1 is e with the initial overlapping width of unit fixed electrode 2; The height of right-angled triangle unit fixed electrode 2 is d, and the length on the base of right-angled triangle unit fixed electrode 2 is c; Shown in figure 13, unit movable electrode 1 is h with the spacing of unit fixed electrode 2, and when movable electrode 1 moved in the X-axis direction in the unit, unit movable electrode 1 was constant with the spacing h of unit fixed electrode 2.The overlapping part of unit movable electrode 1 and unit fixed electrode 2 be shaped as right-angled triangle, the area of overlapping region is s.After unit movable electrode 1 produces displacement x along X axle positive direction; The right-angled triangle base length of this overlapping part is e-x; Highly be

according to leg-of-mutton area computing formula: s=base length * highly/2, the area s that obtains the overlapping region of unit movable electrode 1 and unit fixed electrode 2 is:

$S=\frac{1}{2}\&CenterDot;(e-x)\&CenterDot;(e-x)\&CenterDot;\frac{d}{c}$

Can obtain capacitance size according to the capacity plate antenna formula is:

$C=\mathrm{\&xi;}\&CenterDot;\frac{S}{h}=\frac{\mathrm{\&xi;}}{h}\&CenterDot;\frac{1}{2}\&CenterDot;(e-x)\&CenterDot;(e-x)\&CenterDot;\frac{d}{c}$

Obtain tangential electrostatic force size according to tangential electrostatic force formula, promptly the electrostatic force size on X-direction is:

$F_x=\frac{1}{2}\&CenterDot;\frac{\mathrm{dC}}{\mathrm{dx}}\&CenterDot;{\mathrm{<figure-callout\; id="2"\; label="V"\; filenames="HSA00000087850600011.png,HSA00000087850600012.png"\; state="\{\{state\}\}">V</figure-callout>}}^2=\frac{1}{2}\&CenterDot;{\mathrm{<figure-callout\; id="2"\; label="V"\; filenames="HSA00000087850600011.png,HSA00000087850600012.png"\; state="\{\{state\}\}">V</figure-callout>}}^2\&CenterDot;\frac{\mathrm{\&xi;}}{h}\&CenterDot;\frac{\mathrm{dS}}{\mathrm{dx}}$

The equivalent elastic coefficient that finally obtains on X-direction is:

$k_x=-\frac{{\mathrm{dF}}_x}{\mathrm{dx}}=-\frac{1}{2}\&CenterDot;{\mathrm{<figure-callout\; id="2"\; label="V"\; filenames="HSA00000087850600011.png,HSA00000087850600012.png"\; state="\{\{state\}\}">V</figure-callout>}}^2\&CenterDot;\frac{\mathrm{\&xi;}}{h}\&CenterDot;\frac{d}{c}$

As shown in Figure 4; The front surface of unit fixed electrode 2 is a right-angled triangle; Only a long limit with the rectangle front surface of unit movable electrode 1 overlaps; A right-angle side of right-angled triangle unit fixed electrode 2 is parallel with the long limit of the rectangle front surface of unit movable electrode 1, and the right angle of right-angled triangle unit fixed electrode 2 is positioned at the overlapping region of unit movable electrode 1 and unit fixed electrode 2.The overlapping of unit movable electrode 1 and unit fixed electrode 2 is shaped as trapezoidal, and the area of overlapping region is s.After unit movable electrode 1 produces displacement x along X axle positive direction; This trapezoidal upper base length is d for length of going to the bottom, and highly is e-x.According to trapezoidal area computing formula: s=(the upper base length+length of going to the bottom) * highly/2, the area s that obtains the overlapping region of unit movable electrode 1 and unit fixed electrode 2 is:

$S=\frac{1}{2}\&CenterDot;[d+\frac{c-(e-x)}{c}\&CenterDot;d]\&CenterDot;(e-x)$

Can obtain capacitance size according to the capacity plate antenna formula is:

$C=\mathrm{\&xi;}\&CenterDot;\frac{S}{h}=\frac{\mathrm{\&xi;}}{h}\&CenterDot;S=\frac{\mathrm{\&xi;}}{h}\&CenterDot;\frac{1}{2}\&CenterDot;[d+\frac{c-(e-x)}{c}\&CenterDot;d]\&CenterDot;(e-x)$

Obtain tangential electrostatic force size, the i.e. size of electrostatic force on X-direction according to tangential electrostatic force formula $F_x=\frac{1}{2}\&CenterDot;\frac{\mathrm{DC}}{\mathrm{Dx}}\&CenterDot;{\mathrm{<figure-callout\; id="2"\; label="V"\; filenames="HSA00000087850600011.png,HSA00000087850600012.png"\; state="\{\{state\}\}">V</figure-callout>}}^2=\frac{1}{2}\&CenterDot;{\mathrm{<figure-callout\; id="2"\; label="V"\; filenames="HSA00000087850600011.png,HSA00000087850600012.png"\; state="\{\{state\}\}">V</figure-callout>}}^2\&CenterDot;\frac{\mathrm{\&xi;}}{h}\&CenterDot;\frac{\mathrm{DS}}{\mathrm{Dx}}$ For:

The equivalent elastic coefficient that finally obtains on X-direction is:

$k_x=-\frac{{\mathrm{dF}}_x}{\mathrm{dx}}=\frac{1}{2}\&CenterDot;{\mathrm{<figure-callout\; id="2"\; label="V"\; filenames="HSA00000087850600011.png,HSA00000087850600012.png"\; state="\{\{state\}\}">V</figure-callout>}}^2\&CenterDot;\frac{\mathrm{\&xi;}}{h}\&CenterDot;\frac{d}{c}$

Be convenient explanation technical scheme of the present invention; Below the width a of hypothesis rectangular element movable electrode 1 is 10um; The length b of rectangular element movable electrode 1 is 2100um, and the length c on fixed electrode 2 bases, right-angled triangle unit is 10um, and the height d of right-angled triangle unit fixed electrode 2 is 2000um; Unit movable electrode 1 is 1.5um with the spacing h of unit fixed electrode 2, and unit fixed electrode 2 is 15V with the voltage difference V of unit movable electrode 1.Under the situation as shown in Figure 3, the equivalent elastic coefficient of introducing is-0.1328N/m that this equivalence coefficient of elasticity is negative and is constant; Under the situation as shown in Figure 4, the equivalent elastic coefficient of introducing is 0.1328N/m, and the equivalent elastic coefficient of this introducing is positive number and is constant.

More than in each example; Under set structure; Be that structural parameters and the number of electric capacity is when confirming; Through regulon fixed electrode 2 voltage difference V with unit movable electrode 1, just can on X-direction, introduce different equivalent elastic coefficient, thus adjusting micro mechanical device total coefficient of elasticity on X-direction.

When cell capacitance was differential capacitance, like Fig. 5～shown in Figure 8, the computational methods of the equivalent elastic coefficient of its monolateral introducing were identical with preceding method, and the whole equivalent elastic coefficient of introducing of this differential capacitance then is the equivalent elastic coefficient twice of monolateral introducing.Wherein, when the voltage difference V of set structure and unit fixed electrode 2 and unit movable electrode 1 was definite value, the equivalent elastic coefficient that Fig. 5 and Fig. 7 introduce was negative and is constant that the equivalent elastic coefficient that Fig. 6 and Fig. 8 introduce is positive number and is constant.

When the front surface of unit fixed electrode 2 was zigzag, like Fig. 9, shown in 10, each sawtooth was a triangle, and each sawtooth only overlaps with a long limit of the rectangle front surface of unit movable electrode 1.The rectangle front surface of each sawtooth and unit movable electrode 1 forms a triangle sawtooth capacitance structure; The computational methods of the equivalent elastic coefficient that single triangle sawtooth capacitance structure is introduced are identical with preceding method, and the equivalent elastic coefficient that the whole capacitor structure is introduced is the equivalent elastic coefficient sum that all triangle sawtooth capacitance structures of unit fixed electrode 2 are introduced.

In like manner; If the front surface of unit movable electrode 1 is a triangle and the front surface of unit fixed electrode 2 is rectangle (not illustrating in the drawings); Then can know by the aforementioned calculation method; When the voltage difference V of set structure and unit fixed electrode 2 and unit movable electrode 1 is definite value, has equivalent elastic coefficient that the whole capacitor of this structure introduces or for negative or be positive number, and be constant.

The front surface that Figure 11 and Figure 12 show unit movable electrode 1 is that zigzag and each sawtooth are that front surface trapezoidal, unit fixed electrode 2 simultaneously is the structural representation of the variable-area capacitive structure of the present invention of rectangle.

Like each sawtooth of the zigzag front surface of the unit movable electrode 1 among Figure 11 is trapezoidal and each trapezoidal sawtooth only overlaps with a long limit of the rectangle front surface of unit fixed electrode 2; The overlapping part is triangular in shape, and the rectangle front surface of each sawtooth and unit fixed electrode 2 forms a trapezoidal sawtooth capacitance structure.Computational methods when at this moment, the computational methods of the equivalent elastic coefficient introduced of single trapezoidal sawtooth capacitance structure are triangular in shape with aforementioned overlapping part are identical.When the voltage difference V of set structure and unit fixed electrode 2 and unit movable electrode 1 is definite value; The equivalent elastic coefficient that the whole capacitor structure is introduced is the equivalent elastic coefficient sum that all trapezoidal sawtooth capacitance structures of unit fixed electrode 2 are introduced; And or be negative or for positive number, and be constant.

Like each sawtooth of the zigzag front surface of the unit movable electrode 1 among Figure 12 is trapezoidal and each trapezoidal sawtooth only overlaps with a long limit of the rectangle front surface of unit fixed electrode 2; The part that overlaps is trapezoidal, and the base of the trapezoidal part that overlaps is parallel with the long limit of said rectangle front surface.The rectangle front surface of each sawtooth and unit fixed electrode 2 forms a trapezoidal sawtooth capacitance structure.Computational methods when at this moment, the computational methods of the equivalent elastic coefficient introduced of single trapezoidal sawtooth capacitance structure are trapezoidal with the aforementioned part that overlaps are identical.When the voltage difference V of set structure and unit fixed electrode 2 and unit movable electrode 1 is definite value; The equivalent elastic coefficient that the whole capacitor structure is introduced is the equivalent elastic coefficient sum that all trapezoidal sawtooth capacitance structures of unit fixed electrode 2 are introduced; And or be negative or for positive number, and be constant.

In like manner; The front surface of unit fixed electrode 2 be zigzag and each sawtooth be trapezoidal and the front surface of unit movable electrode 1 equivalent elastic coefficient that to be the variable-area capacitive structure of the present invention (not illustrating in the drawings) of rectangle introduced for or for negative or be positive number, be constant during for definite value at the voltage difference V of set structure and unit fixed electrode 2 and unit movable electrode 1.

Claims (4)

1. the variable-area capacitive structure of a scalable elasticity coefficient of micro mechanical device; In each cell capacitance; The front surface of movable electrode and the front surface of fixed electrode are parallel to each other; It is characterized in that: the front surface of said movable electrode is that the front surface of rectangle and fixed electrode is triangle or zigzag, and perhaps the front surface of said movable electrode is that the front surface of triangle or zigzag and fixed electrode is a rectangle; Said triangle front surface only overlaps with the long limit of of said rectangle front surface, and said zigzag sawtooth only overlaps with a long limit of said rectangle front surface.

2. the variable-area capacitive structure of a kind of scalable elasticity coefficient of micro mechanical device according to claim 1 is characterized in that: the sawtooth of said zigzag front surface is a triangle.

3. the variable-area capacitive structure of a kind of scalable elasticity coefficient of micro mechanical device according to claim 1 is characterized in that: the sawtooth of said zigzag front surface is that the overlapping part of trapezoidal and said trapezoidal sawtooth and said rectangle front surface is triangular in shape.

4. the variable-area capacitive structure of a kind of scalable elasticity coefficient of micro mechanical device according to claim 1; It is characterized in that: the sawtooth of said zigzag front surface is that the overlapping of trapezoidal and said trapezoidal sawtooth and said rectangle front surface partly is trapezoidal, and the base of the said trapezoidal part that overlaps is parallel with the long limit of said rectangle front surface.

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