CN202815008U - Accelerometer - Google Patents
Accelerometer Download PDFInfo
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- CN202815008U CN202815008U CN201220488378.7U CN201220488378U CN202815008U CN 202815008 U CN202815008 U CN 202815008U CN 201220488378 U CN201220488378 U CN 201220488378U CN 202815008 U CN202815008 U CN 202815008U
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Abstract
The utility model relates to an accelerometer which includes a measuring body, an upper cover plate silicon sheet and a lower cover plate silicon sheet which are connected with the measuring body. The measuring body includes a frame, and elastic beams and a mass block arranged in the frame. The mass block is connected with the frame via multiple elastic beams. Each elastic beam includes two elastic folding beams. The elastic folding beams are arranged in symmetry with respect to the central line of the mass block. The upper and lower surfaces of the measuring body are bonded with the cover plate silicon sheets which are provided with electrodes, and each cover plate silicon sheet generates a capacitance with the measuring body. The accelerometer has the advantages of high detection precision, strong stability and low noise.
Description
Technical field
The utility model relates to sensor field, relates in particular to a kind of accelerometer
Background technology
Now, accelerometer is applicable to many application, for example in the intensity of measuring earthquake and collect data, the impact strength when detecting car crass and the angle and direction that detects inclination in mobile phone and game machine.And in the continuous progressive situation of microelectromechanical systems (MEMS) technology, many nano level small-sized accelerometers are extensively adopted by commercialization.
The accelerometer of MEMS commonly used divides two kinds of pressure resistance type and condenser types, and piezoresistive accelerometer for example application number is 200480003916.7, was the Chinese invention patent application on March 15th, 2006 in open day.Piezoresistive accelerometer generally has semi-girder and mass to consist of, and force sensing resistance is arranged on the semi-girder.Mass can move because of acceleration, so that semi-girder distortion, thereby causes the variation of resistance value.But do not having in the more small situation of acceleration or acceleration amplitude, semi-girder can not produce huge distortion.So that resistance value does not have marked change.Only have when the amplitude of acceleration produces distortion to semi-girder greatly, this accelerometer just can detect acceleration.For this reason, this acceleration is in respect of measuring the shortcomings such as inaccurate, that degree of accuracy is not high.
Capacitive accelerometer for example U.S. Patent number US6805008 was the United States Patent (USP) on October 19th, 2004 in open day, and capacitive accelerometer also comprises semi-girder and mass.When acceleration was arranged, outside framework can be to acceleration direction motion, and because the effect of inertia, the displacement meeting of mass is very little, so that mass and another interelectrode clearance distance change and cause the variation of electric capacity.These two kinds of accelerometers are all made by micro fabrication, have the characteristics such as volume is little, cost is low.Yet semi-girder is elastic beam, and only has four semi-girders that four limits of mass are connected with framework.For this reason, when outside framework moved, the displacement amplitude of each semi-girder was very large.And each semi-girder can not produce identical distortion and displacement yet.So that the swing Mode Shape of this accelerometer is slightly asymmetric.
The utility model content
Technical problem to be solved in the utility model is to overcome the deficiency of above-mentioned prior art, provides a kind of swing Mode Shape symmetrical, and the accelerometer with higher degree of accuracy, stability and reliability.
According to a kind of accelerometer provided by the utility model, comprising: the upper cover plate silicon chip and the lower cover silicon chip that measure body, are connected with described measurement body; Described measurement body comprises framework, is positioned at elastic beam and the mass of described framework; Described mass is connected by many groups of described elastic beams with described framework, and every group of described elastic beam comprises two elastic foldable beams, and described elastic foldable beam is take the center line of described mass as the rotational symmetry setting.
The technical scheme that the utility model adopts also has following subsidiary characteristic:
Two ends of described elastic foldable beam are located along the same line.
Described mass is cuboid, and the xsect of described mass is square.
One end of described elastic foldable beam is connected with the corner of described mass respectively.
Described measurement body is epitaxial silicon on the double-sided insulation body (SOI) structure, comprises upper silicon layer, intermediate silicon layers and lower silicon layer; Be respectively arranged with silicon dioxide layer between every two-layer silicon layer.Epitaxial silicon structure is also referred to as two-sided soi structure on the described double-sided insulation body.
A plurality of described elastic beams form in respectively described upper silicon layer and described lower silicon layer symmetrically, consist of double-decker.
Be respectively arranged with electrode on described measurement body, described upper cover plate silicon chip and the described lower cover silicon chip.
Have following advantage according to a kind of accelerometer provided by the utility model: at first, by two-layer symmetrical elastic beam is set respectively between mass and framework up and down so that one-piece construction is more symmetrical, stable.Having in the situation of acceleration, the displacement amplitude of every elastic beam is less also, so that it is relatively more symmetrical to swing Mode Shape.
Description of drawings
Fig. 1 is structural representation of the present utility model.
Fig. 2 is the stereographic map of the measurement body in the utility model.
Fig. 3 is the vertical view of the measurement body in the utility model.
Fig. 4 is three step of the first step to the synoptic diagram of the manufacture method in the utility model.
Fig. 5 be in the utility model manufacture method the 4th the step to the 6th the step synoptic diagram.
Fig. 6 is the 7th step synoptic diagram of the manufacture method in the utility model.
Embodiment
Below in conjunction with accompanying drawing the utility model is done further detailed description:
With reference to Fig. 1, a kind of accelerometer comprises: the upper cover plate silicon chip 2 and the lower cover silicon chip 3 that measure body 1, are connected with described measurement body 1; Be respectively arranged with electrode 4 on described measurement body 1, described upper cover plate silicon chip 2 and the described lower cover silicon chip 3; Described measurement body 1 is two-sided soi structure, comprises upper silicon layer 5, intermediate silicon layers 6 and lower silicon layer 7; Be respectively arranged with silicon dioxide layer 8 between every two-layer silicon layer.A plurality of described elastic beams 12 form in respectively described upper silicon layer 5 and described lower silicon layer 7 symmetrically.
With reference to Fig. 2 and Fig. 3, described measurement body 1 comprises framework 11, is positioned at elastic beam 12 and the mass 13 of described framework 11; Described mass 13 is connected by many groups of described elastic beams 12 with described framework 11, and every group of described elastic beam 12 comprises two elastic foldable beams 121, and described elastic foldable beam 121 is take the center line of described mass 13 as the rotational symmetry setting.Wherein, two of every elastic foldable beam 121 ends are located along the same line.
With reference to Fig. 2 and Fig. 3, preferably, described mass 13 is cuboid, and the xsect of described mass 13 is square.The described elastic beam 12 of many groups is respectively in upper silicon layer 5 and lower silicon layer 7.Preferably, be provided with four groups of elastic beams 12 in every layer of silicon layer.Every group of described elastic beam 12 comprises two elastic foldable beams 121.And an end of every described elastic foldable beam 121 is connected with the corner 131 of described mass 13 respectively.So that mass 13 is not having to remain on horizontality in the situation of acceleration.When detecting acceleration, the elastic foldable beam 121 that is arranged on corner 131 also can limit the displacement amplitude of mass 13, prevents from measuring the data that are higher than top limit or mistake.Mass 13 also can be other shapes in the utility model, such as hexagon, octagon or circle etc.And the elastic beam in the utility model 12, also can be for multilayer, organize structure more, be not restricted to two-layer, four groups every layer structure.
Referring to Fig. 1 and Fig. 3, described measurement body is two-sided soi structure, comprises upper silicon layer 5, intermediate silicon layers 6 and lower silicon layer 7; Be respectively arranged with silicon dioxide layer 8 between every two-layer silicon layer.A plurality of described elastic foldable beams 121 form in respectively described upper silicon layer 5 and described lower silicon layer 7 symmetrically.And be respectively arranged with electrode 4 at described measurement body 1, described upper cover plate silicon chip 2 and described lower cover silicon chip 3.After energising, measure between body 1 and upper cover plate silicon chip 2 and the lower cover silicon chip 3 and all can produce a capacitance.Do not having in the situation of acceleration, it is constant with upper cover plate silicon chip 2 and lower cover silicon chip 3 capacitance each other to measure body 1.And when detecting acceleration, the framework 11 in the described measurement body 1 can because being subjected to acceleration action, move to the acceleration direction.Simultaneously, described elastic beam 12 also can produce certain displacement.But because of inertia effect, the displacement amplitude of mass 13 can less.According to formula C=ε A/d, namely the electric capacity between two parallel conducting strips equals dielectric coefficient and multiply by over against area divided by vertical interval.When described mass 13 produced displacement because of acceleration, the spacing between mass 13 and upper cover plate silicon chip 2 and the lower cover silicon chip 3 can change.For this reason, the electric capacity of measuring between body 1 and upper cover plate silicon chip 2 and the lower cover silicon chip 3 also can change.The acceleration that integrated chip can go out to detect by the change calculations of electric capacity.After acceleration disappeared, elastic beam 12 can be got back to original state, made mass 13 and upper cover plate silicon chip 2 and lower cover silicon chip 3 capacitance each other be attributed to steady state value.
Two-layer and a plurality of displacement amplitudes when effectively having reduced each elastic foldable beam 121 and produce displacement because of acceleration along axisymmetric elastic beam 12 in the mass 13 are set between mass 13 and framework 11.And so that the displacement amplitude of every elastic foldable beam 121 is basic identical.Thereby prevented from excessively detecting because of elastic beam 12 displacements the probability of misdata.In addition, because the displacement amplitude of every elastic foldable beam 121 is all smaller, every elastic foldable beam 121 is got back to the required time of original state and also can greatly be shortened.Many elastic beams 12 are set also so that this accelerometer can detect comparatively small acceleration, have increased the detection degree of accuracy of this accelerometer.
Then, according to Fig. 4,5,6 manufacturing process that describe in detail for the manufacture of the accelerometer in the utility model, may further comprise the steps:
The first step applies respectively photoresist on the upper silicon layer 5 of two-sided soi wafer and lower silicon layer 7.According to specific pattern upper silicon layer 5 and lower silicon layer 7 are exposed afterwards, and develop with developer solution.The pattern that is exposed like this will display.The deep reaction ion etching of recycle silicon is etched to silicon dioxide layer 8 with the partial depth that upper silicon layer 5 and lower silicon layer 7 are exposed.Then carried out etching with reactive ion dry etching or buffered hydrofluoric acid to revealing the silicon dioxide layer 8 of putting outside.Thereby form a plurality of holes that are deep to intermediate silicon layers 6.Use afterwards the photoresist layer is removed.
Second step amasss polysilicon to intermediate silicon layers and fills up described hole at described inner hole deposition, thereby forms electric pathway; Then go out silicon dioxide layer at the upper silicon layer 5 of described two-sided soi wafer and the superficial growth of lower silicon layer 7.And polished in the surface of upper silicon layer 5 and lower silicon layer 7 by chemistry and mechanical polishing method, reach surperficial level and smooth standard.
In the 3rd step, on the upper silicon layer 5 of described two-sided soi wafer and lower silicon layer 7, apply respectively photoresist.According to specific pattern upper silicon layer 5 and lower silicon layer 7 are exposed afterwards, and develop with developer solution.The pattern that is exposed like this will display.Utilize first reactive ion dry etching or buffered hydrofluoric acid that the part that is exposed on the silicon dioxide layer that grows is carried out etching.The deep reaction ion etching of recycling silicon with upper silicon layer 5 and lower silicon layer 7 deep etchings to silicon dioxide layer 8.Carried out etching with reactive ion dry etching or buffered hydrofluoric acid to revealing the silicon dioxide layer 8 of putting outside at last.Thereby form a plurality of elastic beams 12.And after photoresist is removed, utilize high temperature to go out the layer of silicon dioxide layer in the superficial growth of described elastic beam 12, perhaps use chemical deposition (CVD) method at the surface deposition layer of silicon dioxide layer of described elastic beam 12.
The 4th step is with revealing the silicon dioxide of putting outside in the silicon dioxide dry etching removal silicon dioxide layer 8.And the xenon difluoride of again using the deep reaction ion etching of silicon or gaseous state with intermediate silicon layers 6 deep etchings to certain depth.
In the 5th step, use the xenon difluoride of potassium hydroxide or tetramethyl aqua ammonia or ethylenediamine phosphorus benzenediol or gaseous state that the intermediate silicon layers 6 that is etched to certain depth is carried out level and vertically corrosion.And the size in the zone that is corroded according to needs in the intermediate silicon layers 6 is controlled etching time.After intermediate silicon layers 6 is corroded, up and down two-layer free-moving a plurality of elastic beams 12 have been formed.
In the 6th step, dew is put at the described silicon dioxide of the silicon face hydrogen fluoride corrosion with buffered hydrofluoric acid or 49% hydrofluorite or gaseous state.；
In the 7th step, described two-sided soi wafer and lower cover silicon chip after upper cover plate silicon chip, the processing are carried out disposable bonding.
In the manufacturing process of the accelerometer that provides according to the utility model, also further may further comprise the steps:
Processing technology to described upper cover plate silicon chip and lower cover silicon chip also comprises:
A, with described two-sided soi wafer bonding before, apply photoresist at described upper cover plate silicon chip 2 or lower cover silicon chip 3 surfaces.According to specific pattern it is exposed afterwards, and develop with developer solution.The pattern that is exposed like this will display.Recycling deep reaction ion etching or potassium hydroxide or tetramethyl aqua ammonia or ethylenediamine phosphorus benzenediol are etched to silicon dioxide layer 8 with the partial depth that upper cover plate silicon chip 2 or lower cover silicon chip 3 are exposed.Then the hydrogen fluoride with buffered hydrofluoric acid or 49% hydrofluorite or gaseous state carries out etching to the silicon dioxide layer 8 that is exposed, and forms a through hole.And the CD-ROM drive agent removed.
B, apply photoresist at the bonding face of upper cover plate silicon chip 2 and lower cover silicon chip 3, according to specific pattern it is exposed afterwards, and develop with developer solution.The pattern that is exposed like this will display.Recycling deep reaction ion etching or potassium hydroxide or tetramethyl aqua ammonia or ethylenediamine phosphorus benzenediol, the partial depth that respectively upper cover plate silicon chip 2 and lower cover silicon chip 3 is exposed is etched to certain position.Thereby depressed area of each self-forming on the bonding face of upper cover plate silicon chip 2 and lower cover silicon chip 3, and the CD-ROM drive agent removed.
C, with described two-sided soi wafer bonding before, upper cover plate silicon chip 2 and 3 pairs of lower cover silicon chips are cleaned;
D, with described two-sided soi wafer bonding after, depositing metal and extraction electrode 4 on the surface of described upper cover plate silicon chip 2, described lower cover silicon chip 3, by described through hole depositing metal on the surface of described two-sided soi wafer of 3 on described upper cover plate silicon chip 2 or the lower cover silicon chip, and by described through hole extraction electrode 4.
Silicon dioxide layer in the above-mentioned processing technology in the utility model plays its silicon layer that covers of protection, it is not etched or corrodes.
The method of the deep etching described in the utility model and described etching is one or more methods in the following methods: dry etching or wet etching, described dry etching comprises: deep reaction ion etching and the reactive ion etching of silicon.
After producing the accelerometer described in the utility model, also need itself and other electronic component is encapsulated, and the method for encapsulation and required material, equipment, technique all adopt prior art.
Material, equipment, technique used in the said method in the utility model all adopt prior art, but by utilizing these materials and technique, especially the accelerometer that has utilized two-sided soi wafer to manufacture, the variation of matter has occured, and can aim at very accurately and the height of formation symmetrical structure by the elastic beam 13 and the mass 14 that form in two-sided soi wafer corrosion.Compared with the Two-layer Beam of the employed bonding technology manufacturing of prior art, the accelerometer precision of this technique manufacturing is high, error is little, yield rate has also obtained larger lifting.And because etching process is comparatively simple, the production efficiency of this product processes is high, cost is also lower.In addition, geometry of the present utility model and the stressed vibration shape are full symmetrical configuration.So that the detection degree of accuracy of this accelerometer is high.
Claims (7)
1. an accelerometer comprises: the upper cover plate silicon chip and the lower cover silicon chip that measure body, are connected with described measurement body; Described measurement body comprises framework, is positioned at elastic beam and the mass of described framework; It is characterized in that described mass is connected by many groups of described elastic beams with described framework, every group of described elastic beam comprises two elastic foldable beams, and described elastic foldable beam is take the center line of described mass as the rotational symmetry setting.
2. accelerometer as claimed in claim 1 is characterized in that, two ends of described elastic foldable beam are located along the same line.
3. accelerometer as claimed in claim 1 is characterized in that, described mass is cuboid, and the xsect of described mass is square.
4. accelerometer as claimed in claim 1 is characterized in that, an end of described elastic foldable beam is connected with the corner of described mass respectively.
5. accelerometer as claimed in claim 1 is characterized in that, described measurement body is epitaxial silicon structure on the double-sided insulation body, comprises upper silicon layer, intermediate silicon layers and lower silicon layer; Be respectively arranged with silicon dioxide layer between every two-layer silicon layer.
6. accelerometer as claimed in claim 5 is characterized in that, a plurality of described elastic beams form in respectively described upper silicon layer and described lower silicon layer symmetrically, forms double-decker.
7. accelerometer as claimed in claim 1 is characterized in that, is respectively arranged with electrode on described measurement body, described upper cover plate silicon chip and the described lower cover silicon chip.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201220488378.7U CN202815008U (en) | 2012-09-21 | 2012-09-21 | Accelerometer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201220488378.7U CN202815008U (en) | 2012-09-21 | 2012-09-21 | Accelerometer |
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| CN202815008U true CN202815008U (en) | 2013-03-20 |
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| CN201220488378.7U Expired - Lifetime CN202815008U (en) | 2012-09-21 | 2012-09-21 | Accelerometer |
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Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103675347A (en) * | 2012-09-21 | 2014-03-26 | 中国科学院地质与地球物理研究所 | Accelerometer and manufacturing process thereof |
| WO2014044016A1 (en) * | 2012-09-21 | 2014-03-27 | 中国科学院地质与地球物理研究所 | Accelerometer and manufacturing process thereof |
| CN104215232A (en) * | 2013-06-05 | 2014-12-17 | 中国科学院地质与地球物理研究所 | MEMS gyroscope and manufacturing process thereof |
| CN104297522A (en) * | 2013-07-19 | 2015-01-21 | 中国科学院地质与地球物理研究所 | MEMS cantilever type accelerometer and manufacture process thereof |
| CN104297521A (en) * | 2013-07-19 | 2015-01-21 | 中国科学院地质与地球物理研究所 | MEMS high sensitivity transverse acceleration meter and manufacturing technology thereof |
| CN104716018A (en) * | 2013-12-13 | 2015-06-17 | 中芯国际集成电路制造(上海)有限公司 | Staining method and mixed solution for N-well and deep N-well |
| WO2018171161A1 (en) * | 2017-03-24 | 2018-09-27 | 京东方科技集团股份有限公司 | Acceleration sensor and accelerometer |
| CN115728511A (en) * | 2021-08-25 | 2023-03-03 | 上海拜安传感技术有限公司 | Sensitive structure and forming method thereof |
-
2012
- 2012-09-21 CN CN201220488378.7U patent/CN202815008U/en not_active Expired - Lifetime
Cited By (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9828242B2 (en) | 2012-09-21 | 2017-11-28 | Chinese Academy of Sciences Institute of Geology and Geophysics | Accelerometer and its fabrication technique |
| WO2014044016A1 (en) * | 2012-09-21 | 2014-03-27 | 中国科学院地质与地球物理研究所 | Accelerometer and manufacturing process thereof |
| CN103675347A (en) * | 2012-09-21 | 2014-03-26 | 中国科学院地质与地球物理研究所 | Accelerometer and manufacturing process thereof |
| US9476903B2 (en) | 2012-09-21 | 2016-10-25 | Chinese Academy of Sciences Institute of Geology and Geophysics | Accelerometer and its fabrication technique |
| CN104215232A (en) * | 2013-06-05 | 2014-12-17 | 中国科学院地质与地球物理研究所 | MEMS gyroscope and manufacturing process thereof |
| CN104215232B (en) * | 2013-06-05 | 2017-04-05 | 中国科学院地质与地球物理研究所 | A kind of MEMS gyroscope and its manufacturing process |
| CN104297521A (en) * | 2013-07-19 | 2015-01-21 | 中国科学院地质与地球物理研究所 | MEMS high sensitivity transverse acceleration meter and manufacturing technology thereof |
| CN104297522B (en) * | 2013-07-19 | 2018-02-02 | 中国科学院地质与地球物理研究所 | A kind of MEMS cantilever beam type accelerometers and its manufacturing process |
| CN104297522A (en) * | 2013-07-19 | 2015-01-21 | 中国科学院地质与地球物理研究所 | MEMS cantilever type accelerometer and manufacture process thereof |
| CN104716018A (en) * | 2013-12-13 | 2015-06-17 | 中芯国际集成电路制造(上海)有限公司 | Staining method and mixed solution for N-well and deep N-well |
| CN104716018B (en) * | 2013-12-13 | 2017-08-11 | 中芯国际集成电路制造(上海)有限公司 | The color method and mixed solution of N traps and deep N-well |
| WO2018171161A1 (en) * | 2017-03-24 | 2018-09-27 | 京东方科技集团股份有限公司 | Acceleration sensor and accelerometer |
| US10884019B2 (en) | 2017-03-24 | 2021-01-05 | Boe Technology Group Co., Ltd. | Accelerator sensor and accelerometer |
| CN115728511A (en) * | 2021-08-25 | 2023-03-03 | 上海拜安传感技术有限公司 | Sensitive structure and forming method thereof |
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Granted publication date: 20130320 |