CN205139171U - Acceleration sensor - Google Patents
Acceleration sensor Download PDFInfo
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- CN205139171U CN205139171U CN201520964707.4U CN201520964707U CN205139171U CN 205139171 U CN205139171 U CN 205139171U CN 201520964707 U CN201520964707 U CN 201520964707U CN 205139171 U CN205139171 U CN 205139171U
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Abstract
The utility model provides an acceleration sensor, include: the monocrystalline silicon substrate that contains at least one cavity, wherein, the cavity includes: the first cavity of space is provided for the sensitive electric capacity of vertical axial acceleration, the cover is in sensitive apparatus layer on the monocrystalline silicon substrate includes: all hang in the first fixed broach of first cavity, by first fixed broach both ends extend to first cavity outside along the cantilever beam that extends, contain with the first quality piece of the first movable broach of the gapped meshing of first fixed broach and span first cavity and divide into the vary torsion beam of two parts of quality with first quality piece, wherein, torsion beam's both ends are fixed in the outside of first cavity is along last, on being located the sensitive apparatus layer, and the continuous metal electrode of sensitive electric capacity that constitutes with first fixed broach and first movable broach, be located the silica film that hangs beam arm. The utility model provides a low problem of z axle acceleration sensor sensitivity.
Description
Technical field
The utility model relates to semiconductor applications, particularly relates to a kind of acceleration transducer.
Background technology
MEMS (MicroElectroMechanicalSystems) accelerometer is exactly the accelerometer using MEMS technology to manufacture.Owing to have employed micro electro mechanical system (MEMS) technology, its size is reduced greatly, have that volume is little, lightweight, low power consumption and other advantages, be widely used in the fields such as military affairs, auto industry, consumer electronics product.
Wherein, comparatively conventional is capacitance acceleration transducer, and its basic functional principle is, sensitive-mass block is supported in substrate by means of suspender, connects movable electrode simultaneously.Movable electrode and fixed electorde form one or more sensitization capacitance, treat that measuring acceleration acts on the inertial force that sensitive-mass block produces and causes the pole plate gap of sensitization capacitance to change.
In existing Z axis acceleration transducer, the polysilicon sensitive-mass block being suspended from substrate and the polysilicon electrode being fixed on substrate form capacity plate antenna, in process, sensitive-mass block and bottom electrode are provided with insulating medium layer (as monox), be limited to process conditions, often insulating medium thickness is at several microns, causes gap very little.Easily cause sensitization capacitance electrode to contact under overloading acceleration, and cause electric pole short circuit.
Meanwhile, movable polysilicon sensitive-mass structure is by wet method or the release of steaming process technique, and the gap that silicon oxide insulation medium produces is very little, and therefore need to etch intensive release aperture on sensitive-mass block, this measure decreases the effective mass of sensitive-mass block.Also reduce the inertial force that sensitive-mass block produces acceleration, reduce the sensitivity of sensor.Contact under overloading acceleration for preventing sensitization capacitance electrode and cause electric pole short circuit, improve the rigidity of torsion beam, and this measure also reduces the sensitivity of sensor.
Therefore, need to improve prior art.
Utility model content
The utility model embodiment provides a kind of acceleration transducer, for solve z-axis in prior art to the low problem of the sensitivity of sensitization capacitance.
Based on above-mentioned purpose, the utility model provides a kind of acceleration transducer, comprising: the monocrystal silicon substrate comprising at least one cavity; Wherein, described cavity comprises: for vertical axes to provide the first cavity of space to acceleration sensitive electric capacity; Cover the Sensitive Apparatus layer in described monocrystal silicon substrate, comprise: be all suspended from the first fixed fingers of described first cavity, by described first fixed fingers two ends extend to described first cavity outer edge extend semi-girder, comprise the first movable comb engaged having gap with described first fixed fingers the first mass and across described first cavity and by two-part torsion beam such as described first mass are divided into quality not, wherein, the both ends of described torsion beam are fixed on the outer edge of described first cavity; Be positioned at the metal electrode be connected on described Sensitive Apparatus layer and with the sensitization capacitance that described first fixed fingers and the first movable comb are formed; Be positioned at the silicon oxide film of described overarm arm; The compressive stress of described silicon oxide film makes semi-girder bend downwards, make the top of the first fixed fingers be connected on described semi-girder and bottom, with the top of the first movable comb on described first mass and bottom height of formation poor; When vertical axial acceleration effect, described first mass drives the first movable comb to rotate around described torsion beam, and the first movable comb and the first fixed fingers overlapping area change.
Preferably, silicon oxide layer is provided with comprising between the monocrystal silicon substrate of described cavity and described Sensitive Apparatus layer.
Preferably, described first fixed fingers and the first movable comb are symmetrical in described torsion beam both sides.
Preferably, described cavity also comprises: for the axial acceleration sensitive electric capacity of horizontal quadrature two provides two second cavitys in space; The Sensitive Apparatus layer covered on each described second cavity forms horizontal plane horizontal axis acceleration sensitive electric capacity or the vertical axial acceleration sensitive electric capacity perpendicular to described horizontal plane; Wherein, the Sensitive Apparatus layer covered on described second cavity comprises: be suspended from described second cavity and comprise the second mass of the second movable comb, wherein, described second fixed fingers has engaging of gap with described second movable comb, and described second fixed fingers and two sensitization capacitances corresponding to described second movable comb export difference sensitive signal on sensitive direction; And extended to the elastic beam of described second cavity outer edge along sensitive direction symmetry by described second mass; Corresponding, described acceleration transducer also comprises: to be positioned on described Sensitive Apparatus layer and the metal electrode be connected with horizontal axis acceleration sensitive electric capacity with described acceleration sensitive electric capacity separately.
Preferably, in described first cavity, stopper section is provided with; Described stopper section is positioned at the first mass part place of described torsion beam side lighter weight; Stopper section is provided with in described second cavity; Corresponding, described first mass has gap between the part and described stopper section of described torsion beam side lighter weight; Between described second mass and respective stopping portion, there is gap.
As mentioned above, acceleration transducer of the present utility model, there is following beneficial effect: the monocrystalline silicon utilizing electric conductivity good is as substrate, multi-cavity silicon base and described substrate are by Si-Si bonding process integrator, to substrate side carry out thinning after make Sensitive Apparatus layer, solve cavity on substrate cannot deep etching, cause the problem that z-axis direction and sensitivity is low; In addition, described Sensitive Apparatus layer thickness is adjustable arbitrarily to hundreds of micron from several microns; Meanwhile, because monocrystal silicon substrate and Sensitive Apparatus layer are all monocrystalline silicon, there is identical thermal expansivity, widened senor operating temperature scope; In addition, the first fixed fingers is suspended from the gap that the first cavity adds Sensitive Apparatus layer and substrate, which reduces the stray capacitance of sensor, improve the sensitivity of sensor; In addition, semi-girder is arranged on above the cavity body of multi-cavity silicon base, adds the gap of Sensitive Apparatus layer and substrate, decreases the stray capacitance of sensor, improves the sensitivity of sensor; First cavity is the space that the first mass provides FREE TORSION within the scope of certain angle, improves the sensitivity of Z axis sensitization capacitance, and has widened the measurement range of Z-direction acceleration.The degree of depth of cavity determines the maximum twist angle of Z axis first mass around torsion beam; Further, adopt stopper section to limit maximum twist angle, the torsional moment that especially inhibit excessive Z-direction acceleration to produce damages sensor construction.
Accompanying drawing explanation
In order to be illustrated more clearly in the technical scheme in the utility model embodiment, be briefly described to the accompanying drawing used required in the description of the utility model embodiment below, apparently, accompanying drawing in the following describes is only embodiments more of the present utility model, for those of ordinary skill in the art, under the prerequisite not paying creative work, other accompanying drawing can also be obtained according to the content of the utility model embodiment and these accompanying drawings.
Fig. 1 is the structural representation of an embodiment of acceleration transducer of the present utility model.
Fig. 2 is the structural representation of the second fixed fingers and the second movable comb in acceleration transducer of the present utility model.
Fig. 3 is the structural representation that in acceleration transducer of the present utility model, second fixed fingers and the second movable comb are out of shape by acceleration effect.
Fig. 4 is acceleration transducer of the present utility model along the structural representation in x-axis or y-axis cross section.
Fig. 5 is the structural representation of acceleration transducer of the present utility model along z-axis cross section.
Fig. 6 be in acceleration transducer of the present utility model first fixed fingers and the first movable comb without structural representation during z-axis acceleration.
Fig. 7 is the first fixed fingers and the structural representation of the first movable comb when z-axis acceleration in acceleration transducer of the present utility model.
Embodiment
The technical matters solved for making the utility model, the technical scheme of employing and the technique effect that reaches are clearly, be described in further detail below in conjunction with the technical scheme of accompanying drawing to the utility model embodiment, obviously, described embodiment is only the utility model part embodiment, instead of whole embodiments.Based on the embodiment in the utility model, those skilled in the art are not making the every other embodiment obtained under creative work prerequisite, all belong to the scope of the utility model protection.
It should be noted that, the x, y, z axle described in the utility model respectively corresponding horizontal plane horizontal axis, be equally positioned at described horizontal plane and the vertical axial vertical with described horizontal axis and the vertical axes vertical with described horizontal plane to.
As shown in Fig. 1,4 and 5, the utility model provides a kind of acceleration transducer.Described acceleration transducer only can measure the sensor of vertical axes to (z-axis to) acceleration, also can be the sensor comprising three axle axial accelerations.
Described acceleration transducer comprises: monocrystal silicon substrate 100, Sensitive Apparatus layer 500, silicon oxide film 408 and metal electrode 200.
Described monocrystal silicon substrate 100 comprises at least one cavity, and wherein, described cavity comprises: for vertical axes to provide first cavity 102 in space to acceleration sensitive electric capacity.
At this, the acceleration directional correlation that the quantity of described cavity and described acceleration transducer can be responded to.If described sensor is z-axis acceleration transducer, then only can comprise described first cavity 102.If described sensor is 3-axis acceleration sensor, then described cavity comprises described first cavity 102 and two the second cavitys 103.Wherein, described second cavity 103 is for providing space for the acceleration sensitive electric capacity of x-axis or y-axis.Wherein, the degree of depth of described first cavity 102 and the second cavity 103 can be fixed, and also the mobile range of sensitization capacitance corresponding to each cavity or sensitivity can need and set different depth.Such as, the degree of depth of described first cavity 102 is greater than the maximum mobile range of outstanding acceleration sensitive electric capacity thereon.
Described Sensitive Apparatus layer 500 covers in described monocrystal silicon substrate 100.Wherein, described Sensitive Apparatus layer 500 covers all cavitys of described monocrystal silicon substrate.Preferably, silicon oxide layer 101 is provided with comprising between the monocrystal silicon substrate 100 of described cavity and described Sensitive Apparatus layer 500.
It should be noted that, the thickness of described silicon oxide layer 101 only describes micron-sized numerical value, but this precision not necessarily are at micron order, also can be more high precision.
Wherein, the Sensitive Apparatus layer 500 covered on described first cavity comprises: the first fixed fingers 405 being all suspended from described first cavity 102, the semi-girder 407 of described first cavity 102 outer edge extension is extended to by described first fixed fingers 405 two ends, comprise the first mass 401 of the first movable comb 404 engaged having gap with described first fixed fingers 405, and across described first cavity 102 and by two-part torsion beam 402 such as described first mass 401 are divided into quality not, wherein, described semi-girder 407 to be suspended from above described first cavity 102 and along its inside edge, and with described first fixed fingers 405 global formation.The end of described semi-girder 407 is positioned at the outer edge of described first cavity near the position of described torsion beam 402, and the both ends of described semi-girder 407 and torsion beam 402 are fixed on the outer edge of described first cavity.Such as, the both ends of described semi-girder 407 and torsion beam 402 are fixed on the outer edge of described first cavity by anchor portion 403.
At this, described first fixed fingers 405 and the in a row part being arranged in described first mass 401 heavier mass of the first movable comb 404 or the in a row part being arranged in described first mass 401 lighter weight.Wherein, between described first fixed fingers 405 and the first movable comb 404, there is gap, formed the sensitization capacitance of vertical axes to (z-axis) to make each first fixed fingers 405 and the first movable comb 404.Described semi-girder 407 is positioned at the two ends of the first fixed fingers 405 in a row.When produced acceleration transducer accelerates mobile along z-axis, according to Newton second law and leverage principle, described first movable comb 404 axially rotates around described torsion beam 402 place.So the right opposite changed between this first movable comb 404 and first fixed fingers 405 amasss, make z-axis to the change of sensitization capacitance and the proportional relation of acceleration change.
Preferably, in order to make exported z-axis sensitive signal filtering noise signal, improve signal to noise ratio (S/N ratio), described first fixed fingers 405 and the first movable comb 404 in a row be symmetrical in described torsion beam 402 both sides.Accordingly, the two ends that described in described semi-girder 407, first fixed fingers 405 is arranged extend along described first cavity 102 inside edge, and are fixed on by anchor portion 403 on the outer edge of described first cavity 102.
When described acceleration transducer accelerates mobile along z-axis, in the first mass 401 split by torsion beam 402, the part of heavier mass and the part of lighter weight produce and drive the first respective movable comb 404 along described torsion beam 402 axial rotation, to export the sensitive signal of difference.
Described semi-girder 407 is installed with silicon oxide film 408.Described silicon oxide film 408 is at a few microns.
It should be noted that, the thickness of described silicon oxide film 408 is only described to micron order, but this precision not necessarily are at micron order, also can be more high precision.
Particularly, described silicon oxide film 408 is generate silicon oxide film on described Sensitive Apparatus layer 500 after, then is eroded by the silicon oxide film except sentencing except the semi-girder 407 corresponding to semi-girder pattern and obtain.
As shown in Figure 6, the compressive stress of described silicon oxide film 408 makes semi-girder 407 bend downwards.When described sensor do not receive z-axis to acceleration time, be connected to the top of the first fixed fingers 405 on described semi-girder 407 and bottom, with the top of the first movable comb 404 on described first mass 401 and bottom height of formation poor.
As shown in Figure 7, when vertical axial acceleration effect, described first mass 401 drives the first movable comb 404 to rotate around described torsion beam, and the first movable comb 404 and the first fixed fingers 405 overlapping area change.
If what described first fixed fingers 405 and the first movable comb 404 were symmetry in a row establishes, described first movable comb 404 and the first fixed fingers 405, when overlapping area changes, export difference sensitive signal.Such as, when vertical axial acceleration effect, when first movable comb 404 of the first mass 401 both sides is rotated around torsion beam 402, the polar plate area of the sensitization capacitance that side is made up of the first movable comb 404 and the first fixed fingers 405 reduces, and the polar plate area of sensitization capacitance that simultaneously opposite side is made up of the first movable comb 404 and the first fixed fingers 405 increases.So, difference sensitive signal is exported.
If also comprise in described acceleration transducer: the acceleration sensitive electric capacity of x-axis and y-axis, then the Sensitive Apparatus layer covered on corresponding second cavity 103 comprises: perpendicular to a wherein horizontal axis sensitive direction and by two outer edges of described second cavity 103 symmetry respectively to the second fixed fingers 205 (or 305) extended in chamber; Be suspended from described second cavity 103 and comprise the second mass 201 (or 301) of the second movable comb 204 (or 304), wherein, described second fixed fingers 205 (or 305) has engaging of gap with described second movable comb 204 (or 304), and described second fixed fingers 205 (or 305) exports difference sensitive signal to two sensitization capacitances corresponding to described second movable comb 204 (or 304) on corresponding sensitive direction; And extended to the elastic beam 202 (or 302) of described second cavity 103 outer edge along sensitive direction symmetry by described second mass 201 (or 301).Wherein, described elastic beam 202 (or 302) may extend to described second cavity 103 inside edge place and is connected to described second cavity 103 outer edge by anchor portion 203 (or 303).
At this, gap is left, with the acceleration sensitive electric capacity making manufactured described second movable comb 204 (or 304) and the second fixed fingers 205 (or 305) be formed corresponding x-axis or y-axis direction between described second movable comb 204 (or 304) and the second fixed fingers 205 (or 305).Meanwhile, described second movable comb 204 (or 304) and the second fixed fingers 205 (or 305) set in a row.Wherein, the sensitization capacitance that described second fixed fingers 205 (or 305) and the second movable comb 204 (or 304) are formed only can be positioned at described second mass 201 (or 301) side.Preferably, axisymmetricly, two to ranked second fixed fingers 205 (or 305) interlaced with each other according to range for described second mass 201 (or 301), and described second movable comb 204 (or 304) is engaged on the centre of range.So, make when responding to the acceleration of x-axis or y-axis direction, the sensitization capacitance that described second fixed fingers 205 (or 305) and the second movable comb 204 (or 304) are formed can export the sensitive signal of difference.As shown in Figure 2,3.
At this, described elastic beam 202 (or 302) is wriggled and the outer edge of described second cavity 103 that arrives by the side of described second mass 201 (or 301), and is fixed on the outer edge of described second cavity 103.Such as, the serpentine curve that bends for right angle of described elastic beam 202 (or 302).
Such as, as shown in Figure 2, when acceleration does not change, two the second fixed fingers in figure below and and its second movable comb engaged between interval A1, and two the second fixed fingers above figure and and the second movable comb of its engagement between interval A2 corresponding; Two the second fixed fingers in figure below and and its second movable comb engaged between interval A3, and two the second fixed fingers above figure and and the second movable comb of its engagement between interval A4 corresponding.Wherein, the length of interval A1 and A4 is equal, and the length of interval A2 and A3 is equal, but the length of interval A1 and A2 is not etc.
As shown in Figure 3, when sensing acceleration change, figure below two the second fixed fingers and and its second movable comb engaged between interval A1 become large; Two the second fixed fingers above figure and and its second movable comb engaged between interval A2 become large; Figure below two the second fixed fingers and and its second movable comb engaged between interval A3 diminish; And two the second fixed fingers above figure and and its second movable comb engaged between interval A4 diminish.This makes the sensitization capacitance formed below figure reduce, and the sensitization capacitance that figure top is formed increases.So achieve the output of difference sensitive signal.
The quantity of described metal electrode 200 is relevant with the axis that described acceleration transducer is responded to.Each described metal electrode 200 is positioned on described Sensitive Apparatus layer 500.The sensitization capacitance that described metal electrode 200 is formed with described first fixed fingers 405 and the first movable comb 404 is connected, and the sensitization capacitance that described metal electrode 200 is formed with described second fixed fingers 205 (or 305) and the second movable comb 204 (or 304) is connected.As shown in Figure 1.
Particularly, deposited metal on described Sensitive Apparatus layer 500, according to the wiring pattern preset, adopts the metal line that wet corrosion technique etches the metal electrode 200 for being connected with external pin and is connected with each sensitization capacitance by described metal electrode.Wherein metal electrode 200 can be arranged by yi word pattern as shown in Figure 1.
Embodiment four
Be with embodiment three difference, in each cavity of described monocrystal silicon substrate 100, be also provided with stopper section 411 (or 207,307).Wherein, stopper section 411 is positioned at the first mass part place of described torsion beam 402 side lighter weight.Between described second mass 201 (or 301) and respective stopping portion 207 (or 307), there is gap.
Such as, the first mass 401 is divided equally by described torsion beam 402, and in described first mass 401, the part of lighter weight comprises void region, the corresponding described void region, stopper section 411 in described first cavity 102 and establishing.
With in embodiment three unlike, described first mass 401 or the second mass 201 (or 301) relevant with the maximum range that the pore size between respective stopping portion and corresponding sensitization capacitance are responded to respectively.
Such as, for z-axis acceleration sensitive electric capacity, gap between described first mass 401 and stopper section 411 should be guaranteed: the first movable comb 404 mobile distance should be less than distance between itself and adjacent first fixed fingers 405, and guarantee when the first movable comb 404 is rotated along torsion beam 402 and the first fixed fingers 405 still forms the ultimate range of electric capacity.
And for example, for x-axis and y-axis acceleration sensitive electric capacity, described second mass 201 (or 301) is the second movable comb 204 (or 304) mobile distance with the gap of stopper section 207 (or 307), the distance between the second movable comb 204 (or 304) and adjacent second fixed fingers 205 (or 305) should be less than, collide to prevent sensitization capacitance two-plate.
Be example with reference to structure shown in figure 1,4,5, the structure example of described acceleration transducer is as follows:
Monocrystal silicon substrate is provided with the first cavity 102 and two the second cavitys 103, in each cavity, is equipped with stopper section 411,207,307.Wherein, the stopper section 411 in the first cavity 102 is positioned at the position of center deviation side.Stopper section 207,307 in two the second cavitys 103 is positioned at about center.Described monocrystal silicon substrate 100 is provided with silicon oxide layer 101.Each cavity 102,103 on described silicon oxide layer 101 is provided with Sensitive Apparatus layer 500.
The Sensitive Apparatus layer be positioned on described first cavity 102 comprises: the first fixed fingers 405 being all suspended from described first cavity 102, the semi-girder 407 extended along described first cavity 102 inside edge by described first fixed fingers 405 two ends, comprise the first mass 401 of the first movable comb 404 engaged having gap with described first fixed fingers 405, and across described first cavity 102 and by two-part torsion beam 402 such as described first mass 401 are divided into quality not, wherein, the both ends of described semi-girder 407 and torsion beam 403 are fixed on the outer edge of described first cavity 102.Described first position, mass 401 corresponding stopper section 411 is provided with the void region leaving space with this stopper section 411, and the both sides quality making described first mass 401 be positioned at torsion beam 402 is not etc.
The Sensitive Apparatus layer laid respectively on two described second cavitys 103 comprises: the second fixed fingers 205 (or 305) extended in chamber perpendicular to sensitive direction and by two outer edges of described second cavity 103 symmetry; Be suspended from described second cavity 103 and comprise the second mass 201 (or 301) of the second movable comb 204 (or 304), wherein, described second fixed fingers 205 (or 305) has engaging of gap with described second movable comb 204 (or 304); And extended to the elastic beam 202 (or 302) of described second cavity 103 outer edge along sensitive direction symmetry by described second mass 201 (or 301).Wherein, described elastic beam 202 (or 302) is wriggled and the outer edge of described second cavity 103 that arrives by the side of described second mass 201 (or 301), and is fixed on by anchor portion 203 (or 303) on the outer edge of corresponding second cavity 103.
Based on the structure shown in above-mentioned Fig. 1,4,5, when described acceleration transducer is subject to the effect of x-axis directional acceleration, because of the special design of elastic beam, therefore, this first mass 401 and the second mass 301 all insensitive in x-axis.And when x-axis to the second mass 201 time be subject to the effect of x-axis directional acceleration time, x-axis is there is to movement in described second mass 201 under elastically-deformable drive occurs elastic beam 202, distance between side second movable comb 204 on described second mass 201 and the second fixed fingers 205 of its pairing is increased, meanwhile, the distance between opposite side second movable comb 204 and the second fixed fingers 205 of its pairing reduces.So, described second mass 201 place sensitization capacitance according to x-axis acceleration change export difference to should the sensitive signal of acceleration.If excessive at x-axis acceleration upwards, described second mass 201 stops 207 by corresponding stopper section, effectively prevents the second movable comb 204 and the second fixed fingers 205 from colliding.Meanwhile, the respective stopping portion 411,307 that the first mass 401 and the second mass 301 surround also can stop the abnormality vibration of respective quality block to the harmful effect of corresponding axially sensitization capacitance.
Described acceleration transducer accelerates the similar process that the process of movement and above-mentioned x-axis accelerate movement in y-axis direction, be not described in detail in this.
When described acceleration transducer accelerates mobile in z-axis direction, in described first mass 401 part of heavier mass and the part of lighter weight drive the first movable comb 404 of corresponding side, along torsion beam 402, deflection reverse each other occurs separately (part as heavier mass deflects down, the part of corresponding lighter weight upward deflects), the sensitization capacitance formed between the first movable comb 404 of described first mass 401 both sides and the first fixed fingers 405 exports difference sensitive signal.Meanwhile, when when z-axis acceleration is upwards excessive, the respective stopping portion 411 that described first mass B1 surrounds also can stop the abnormality vibration of described first mass 401 to the harmful effect of corresponding axially sensitization capacitance.
In sum, acceleration transducer of the present utility model, the monocrystalline silicon utilizing electric conductivity good is as substrate, multi-cavity silicon base and described substrate are by Si-Si bonding process integrator, to substrate side carry out thinning after make Sensitive Apparatus layer, described Sensitive Apparatus layer thickness is adjustable arbitrarily to hundreds of micron from several microns; Meanwhile, because monocrystal silicon substrate and Sensitive Apparatus layer are all monocrystalline silicon, there is identical thermal expansivity, widened senor operating temperature scope; In addition, the first fixed fingers is suspended from the gap that the first cavity adds Sensitive Apparatus layer and substrate, which reduces the stray capacitance of sensor, improve the sensitivity of sensor; Further, stopper section is adopted to prevent sensitization capacitance pole plate to collide the problems such as caused device failure.So the utility model effectively overcomes various shortcoming of the prior art and tool high industrial utilization.
Above-described embodiment is illustrative principle of the present utility model and effect thereof only, but not for limiting the utility model.Any person skilled in the art scholar all without prejudice under spirit of the present utility model and category, can modify above-described embodiment or changes.Therefore, such as have in art and usually know that the knowledgeable modifies or changes not departing from all equivalences completed under the spirit and technological thought that the utility model discloses, must be contained by claim of the present utility model.
Claims (5)
1. an acceleration transducer, is characterized in that, comprising:
Comprise the monocrystal silicon substrate of at least one cavity; Wherein, described cavity comprises: for vertical axes to provide the first cavity of space to acceleration sensitive electric capacity;
Cover the Sensitive Apparatus layer in described monocrystal silicon substrate, comprise: be all suspended from the first fixed fingers of described first cavity, by described first fixed fingers two ends extend to described first cavity outer edge extend semi-girder, comprise the first movable comb engaged having gap with described first fixed fingers the first mass and across described first cavity and by two-part torsion beam such as described first mass are divided into quality not, wherein, the both ends of described torsion beam are fixed on the outer edge of described first cavity;
Be positioned at the metal electrode be connected on described Sensitive Apparatus layer and with the sensitization capacitance that described first fixed fingers and the first movable comb are formed;
Be positioned at the silicon oxide film on described overarm arm, the compressive stress of described silicon oxide film makes semi-girder bend downwards, make the top of the first fixed fingers be connected on described semi-girder and bottom, with the top of the first movable comb on described first mass and bottom height of formation poor;
When vertical axial acceleration effect, described first mass drives the first movable comb to rotate around described torsion beam, and the first movable comb and the first fixed fingers overlapping area change.
2. acceleration transducer according to claim 1, is characterized in that, is provided with silicon oxide layer comprising between the monocrystal silicon substrate of described cavity and described Sensitive Apparatus layer.
3. acceleration transducer according to claim 1, is characterized in that, described first fixed fingers and the first movable comb are symmetrical in described torsion beam both sides.
4. acceleration transducer according to claim 1, is characterized in that, described cavity also comprises: for the axial acceleration sensitive electric capacity of horizontal quadrature two provides two second cavitys in space;
The Sensitive Apparatus layer covered on each described second cavity forms horizontal plane horizontal axis acceleration sensitive electric capacity or the vertical axial acceleration sensitive electric capacity perpendicular to described horizontal plane;
Wherein, the Sensitive Apparatus layer covered on described second cavity comprises:
Be suspended from described second cavity and comprise the second mass of the second movable comb, wherein, described second fixed fingers has engaging of gap with described second movable comb, and described second fixed fingers and two sensitization capacitances corresponding to described second movable comb export difference sensitive signal on sensitive direction;
And extended to the elastic beam of described second cavity outer edge along sensitive direction symmetry by described second mass;
Corresponding, described acceleration transducer also comprises: to be positioned on described Sensitive Apparatus layer and the metal electrode be connected with horizontal axis acceleration sensitive electric capacity with described acceleration sensitive electric capacity separately.
5. acceleration transducer according to claim 4, is characterized in that, in described first cavity, be provided with stopper section; Described stopper section is positioned at the first mass part place of described torsion beam side lighter weight; Stopper section is provided with in described second cavity;
Corresponding, described first mass has gap between the part and described stopper section of described torsion beam side lighter weight; Between described second mass and respective stopping portion, there is gap.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520964707.4U CN205139171U (en) | 2015-11-27 | 2015-11-27 | Acceleration sensor |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520964707.4U CN205139171U (en) | 2015-11-27 | 2015-11-27 | Acceleration sensor |
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| CN205139171U true CN205139171U (en) | 2016-04-06 |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106809799A (en) * | 2015-11-27 | 2017-06-09 | 上海微联传感科技有限公司 | Acceleration transducer and its manufacture method |
| CN106970244A (en) * | 2017-04-18 | 2017-07-21 | 四川知微传感技术有限公司 | Multi-range MEMS closed-loop accelerometer |
| WO2019174243A1 (en) * | 2018-03-14 | 2019-09-19 | 京东方科技集团股份有限公司 | Acceleration sensor, capacitance detection circuit and method, acceleration processing circuit and method, storage medium, and electronic device |
-
2015
- 2015-11-27 CN CN201520964707.4U patent/CN205139171U/en not_active Withdrawn - After Issue
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106809799A (en) * | 2015-11-27 | 2017-06-09 | 上海微联传感科技有限公司 | Acceleration transducer and its manufacture method |
| CN106809799B (en) * | 2015-11-27 | 2018-07-20 | 上海微联传感科技有限公司 | Acceleration transducer and its manufacturing method |
| CN106970244A (en) * | 2017-04-18 | 2017-07-21 | 四川知微传感技术有限公司 | Multi-range MEMS closed-loop accelerometer |
| CN106970244B (en) * | 2017-04-18 | 2023-03-28 | 四川知微传感技术有限公司 | Multi-range MEMS closed-loop accelerometer |
| WO2019174243A1 (en) * | 2018-03-14 | 2019-09-19 | 京东方科技集团股份有限公司 | Acceleration sensor, capacitance detection circuit and method, acceleration processing circuit and method, storage medium, and electronic device |
| US11231440B2 (en) | 2018-03-14 | 2022-01-25 | Hefei Boe Optoelectronics Technology Co., Ltd. | Acceleration sensor, capacitance detection circuit and method, acceleration processing circuit and method, storage medium and electronic device |
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