CN1239893C - Capacitive pressure micro-sensing element and its applied fingerprint reading chip - Google Patents
Capacitive pressure micro-sensing element and its applied fingerprint reading chip Download PDFInfo
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- CN1239893C CN1239893C CN 02132054 CN02132054A CN1239893C CN 1239893 C CN1239893 C CN 1239893C CN 02132054 CN02132054 CN 02132054 CN 02132054 A CN02132054 A CN 02132054A CN 1239893 C CN1239893 C CN 1239893C
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- thin plate
- sensing element
- capacitive pressure
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- 239000000725 suspension Substances 0.000 claims abstract description 67
- 239000000758 substrate Substances 0.000 claims abstract description 40
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 4
- 229910052710 silicon Inorganic materials 0.000 claims description 4
- 239000010703 silicon Substances 0.000 claims description 4
- 239000003990 capacitor Substances 0.000 claims description 3
- 239000010409 thin film Substances 0.000 claims 2
- 230000035945 sensitivity Effects 0.000 abstract description 10
- 238000006073 displacement reaction Methods 0.000 abstract description 9
- 230000000694 effects Effects 0.000 abstract description 6
- 239000012528 membrane Substances 0.000 description 12
- 238000005516 engineering process Methods 0.000 description 6
- 238000010586 diagram Methods 0.000 description 5
- 230000008859 change Effects 0.000 description 4
- 238000013461 design Methods 0.000 description 4
- 238000012545 processing Methods 0.000 description 4
- 230000009471 action Effects 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 238000013519 translation Methods 0.000 description 2
- 230000008901 benefit Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000005192 partition Methods 0.000 description 1
- NHDHVHZZCFYRSB-UHFFFAOYSA-N pyriproxyfen Chemical compound C=1C=CC=NC=1OC(C)COC(C=C1)=CC=C1OC1=CC=CC=C1 NHDHVHZZCFYRSB-UHFFFAOYSA-N 0.000 description 1
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- Measurement Of The Respiration, Hearing Ability, Form, And Blood Characteristics Of Living Organisms (AREA)
Abstract
A capacitive pressure micro-sensing element and fingerprint reading chip using the same, wherein the capacitive pressure micro-sensing element comprises a substrate, and is characterized in that a first-stage suspension structure is arranged above the substrate and comprises a suspension thin plate and at least one cantilever beam supporting leg, the periphery of the suspension thin plate extends outwards in parallel with the suspension thin plate; the first bump structure is arranged at the center of the upper surface of the suspension thin plate; the second-step suspension structure is arranged on the upper surface of the first bump structure, the central part of the second-step suspension structure is contacted with the first bump structure, and the second-step suspension structure wraps the first-step suspension structure to form a closed cavity with the substrate; when the external pressure changes, the center of the second-stage suspension structure has the maximum displacement, so that the whole first-stage suspension structure is driven to translate, the maximum sensing capacitance variable can be achieved, and the sensing sensitivity is greatly improved; furthermore, a pressure micro-sensing element array can be formed on a substrate to be used as a fingerprint reading chip, which has the effect of truly restoring the shape of fingerprint peaks and has practicability.
Description
Technical field
The present invention relates to the little sensor of a kind of pressure, particularly a kind of hydrodynamic pressure that is applied to detects and biological tactile pressure sensing, particularly the capacitive pressure micro-sensing element of finger print line peak profile detecting and the fingerprint access chip of application thereof.
Background technology
The method of the capacitive pressure sensor processing procedure made from micro-electromechanical technology is quite a lot of, comprised and utilized build micro-processing technology (Bulkmicromachining) and face type micro-processing technology (Surfacemicromachining), but the reference pressure cavity that its structure does not break away from pair of parallel plate electric capacity and coated basically, as shown in Figure 1, it is the basic structure cut-open view at present known capacitive pressure micro-sensing element 10, capacitive pressure micro-sensing element 10 is that pair of parallel plate electric capacity has comprised a membrane electrode 12 and a fixed electorde (not shown) and is positioned on the substrate 14, and form a closed cavity 16 with reference pressure P0 14 of membrane electrode 12 and substrates, as ambient pressure P1 during greater than the pressure P 0 of closed cavity 16, as shown in Figure 2, membrane electrode 12 meeting stress deformations, because around the membrane electrode 12 is to be fastened on the substrate 14, so membrane electrode 12 central authorities have maximum deformation quantity d, and then the deflection that successively decreases in regular turn is zero deflection around film, so the shortcoming of structural design maximum is limited because of the electric capacity that pressure change changed for this parallel plate capacitor, thereby has limited the sensitivity of capacitive pressure micro-sensing element 10.
Because electric capacity is directly proportional with the area of parallel-plate, be inversely proportional to the spacing of two parallel-plates, therefore known settling mode is the area of increasing membrane electrode 12 mostly, but this measure will increase chip cost again; Or, so introduce bonding (sticking) problem of another membrane stress distortion or membrane structure and substrate again with the spacing that face type micro-processing technology dwindles parallel plate capacitor.
Therefore, this creator studies improvement at above-mentioned problem, and creates the present invention.
Summary of the invention
The present invention is the fingerprint access chip that a kind of capacitive pressure micro-sensing element and application thereof will be provided, and makes it reach maximum sense capacitance variable with solution, effectively improves sensing sensitivity, reaches the technical matters of accurate identification fingerprint line peak shape effect.
It is such solving the problems of the technologies described above the technical scheme that is adopted:
A kind of capacitive pressure micro-sensing element comprises a substrate, it is characterized in that: this substrate top is provided with one first rank suspension structure, and this first rank suspension structure comprises the outwards parallel at least one semi-girder leg that should the suspension thin plate extends of a suspension thin plate and periphery thereof;
One first projection cube structure is arranged on the centre of this suspension thin plate upper surface;
One second rank suspension structure, it is arranged on this first projection cube structure upper surface, and its middle body contacts with this first projection cube structure, and coats this first rank suspension structure and form a closed cavity with substrate;
Be provided with a floating electrode in this suspension thin plate, make and form a sense capacitance between itself and this substrate;
This second rank suspension structure is a membrane structure;
The upper surface of this second rank suspension structure is provided with second projection cube structure of stress concentration point when applying as pressure.
A kind of fingerprint access chip is characterized in that: include a substrate and a plurality of capacitive pressure micro-sensing element, it is arranged on the upper surface of this substrate and forms a pressure sensing element array;
This substrate is to be silicon substrate;
Each this capacitive pressure micro-sensing element is to comprise:
One substrate;
One first rank suspension structure is arranged on this substrate top, comprises the outwards parallel at least one semi-girder leg that should the suspension thin plate extends of a suspension thin plate and periphery thereof;
One first projection cube structure is arranged on the centre of this suspension thin plate upper surface;
One second rank suspension structure, it is arranged on this first projection cube structure upper surface, and its middle body contacts with this first projection cube structure, and coats this first rank suspension structure and form a closed cavity with this substrate;
Be to be provided with a floating electrode in this suspension thin plate, make and form a sense capacitance between itself and this substrate;
This second rank suspension structure is to be a membrane structure;
The upper surface of this second rank suspension structure is provided with second projection cube structure of stress concentration point when applying as pressure.
The present invention proposes a kind of capacitive pressure micro-sensing element with two stepwise suspension structures, and its battery lead plate has maximum translational displacement amount when extraneous pressure change, to reach maximum sense capacitance variable, improves sensing sensitivity; This capacitive pressure micro-sensing element forms when array is arranged and can be applicable to fingerprint access chip, with the line peak shape of accurate identification fingerprint.
The present invention one implements the sample attitude, a kind of capacitive pressure micro-sensing element structure is to comprise a substrate, one first rank suspension structure is set above this substrate, it is at least one semi-girder leg that comprises that a suspension thin plate and periphery thereof outwards extend in parallel, and in the centre of suspension thin plate upper surface one first projection cube structure is set; And one second the rank suspension structure be arranged on the first projection cube structure upper surface, middle body is contacted with first projection cube structure, and coats this first rank suspension structure and form a closed cavity with this substrate.
Another implements the sample attitude the present invention, a kind of fingerprint access chip structure is to comprise a substrate, upper surface at this substrate is provided with a plurality of above-mentioned capacitive pressure micro-sensing elements, it is to form a pressure sensing element array with the two-dimensional array arrangement, make it reach maximum sense capacitance variable thereby solved, effectively improve sensing sensitivity, reach the technical matters of accurate identification fingerprint line peak shape effect.
The present invention is simple in structure, and its advantageous effect is as follows:
1, the present invention provides a kind of capacitive pressure micro-sensing element, utilize the suspension structure design of two stepwises, when extraneous pressure change, the second rank suspension structure central authorities produce maximum displacement, and then drive the first rank suspension structure translation, and make the whole first rank suspension structure also reach maximum displacement, to reach maximum sense capacitance variable, effectively improve sensing sensitivity.
2, the present invention is at the area that reduces sensing element, has concurrently and keeps good sensing sensitivity, with as the hydrodynamic pressure sensing, more may extend to brand-new tactile pressure sensing.
3, the present invention is providing a kind of pressure type fingerprint to read chip, so that capacitive pressure micro-sensing element array to be set on a chip, as fingerprint line peak pressure power sensing, utilization is read the capacitance curve that stays on the chip corresponding to this line peak at pressure type fingerprint, reaches the effect of accurate identification fingerprint line peak shape.
Description of drawings
Fig. 1 is a known capacitance formula pressure micro-sensing element structural representation.
Fig. 2 is the membrane electrode stress deformation synoptic diagram of known capacitance formula pressure micro-sensing element.
Fig. 3 is the structure cut-open view of capacitive pressure micro-sensing element of the present invention.
Fig. 4 is the first rank suspension structure of capacitive pressure micro-sensing element of the present invention and the vertical view of first projection cube structure.
Fig. 5 is subjected to ambient pressure to make the action synoptic diagram of time spent for capacitive pressure micro-sensing element of the present invention.
Fig. 6 is an Application Example synoptic diagram of the present invention.
Fig. 7 is applied in the synoptic diagram of fingerprint access chip for the present invention.
Embodiment
The present invention is the capacitive pressure micro-sensing element of two stepwises, comprised the suspension structure design of second order, as shown in Figures 3 and 4, it is to be respectively structure cut-open view of the present invention and part-structure vertical view, capacitive pressure micro-sensing element 20 comprises a substrate 22, one first rank suspension structure 24 is set above substrate 22, it is to comprise outwards parallel four the semi-girder legs 28 that should suspension thin plate 26 extend in a suspension thin plate 26 and periphery four corners thereof, make suspension thin plate 26 be suspended in substrate 22 tops evenly with support by semi-girder leg 28, suspension thin plate 26 contains a floating electrode (not shown), make 22 of itself and substrates form a sense capacitance, one first projection cube structure 30 is set in the centre of suspension thin plate 26 upper surfaces; One second rank suspension structure 32 is arranged on the upper surface of first projection cube structure 30, the second rank suspension structure, 32 middle bodies are contacted with first projection cube structure 30 or a minim gap is only arranged, this second rank suspension structure 32 is a membrane structure, cover the first rank suspension structure 24 and and 22 of substrates form a closed cavity 34, wherein, upper surface at the second rank suspension structure 32 more can be provided with one second projection cube structure (not shown), the stress concentration point when applying as pressure.
Action synoptic diagram of the present invention as shown in Figure 5, when ambient pressure changes, the second rank suspension structure, 32 central authorities have maximum displacement d, and then drive suspension thin plate 26 can be by the support of flexible semi-girder leg 28, and it is approximate abreast to bottom offset, make the whole first rank suspension structure 24 also reach the displacement of d, so capacitive pressure micro-sensing element 20 of the present invention can reach maximum sense capacitance variable.
Biggest advantage of the present invention is for still keeping good sensing sensitivity under the area that reduces sensing element, not only can replace traditional pressure sensing element as the hydrodynamic pressure sensing, more can extend to brand-new tactile pressure sensing, particularly fingerprint line peak pressure power sensing.When capacitive pressure micro-sensing element 20 is done the two-dimensional array arrangement, can become a kind of pressure type fingerprint and read chip 40, see also shown in Figure 6, it is the perspective view that reads chip 40 for pressure type fingerprint of the present invention, it is that upper surface at a silicon substrate 42 is provided with a plurality of capacitive pressure micro-sensing elements 20 that pressure type fingerprint reads chip 40, it is to form a pressure sensing element array with the arrangement of two dimension (2-D) array way, and the upper face center at each capacitive pressure micro-sensing element 20 is provided with second projection cube structure 44, stress concentration point when contacting as fingerprint line peak, strengthen the stressed displacement of the second rank suspension structure 32, so that electric capacity change amount is maximum, reach the effect that increases sensitivity.
When finger 46 these pressure type fingerprints of contact read chip 40, as shown in Figure 7, the irregularly shaped line peak (Ridge) 48 of pointing 46 surfaces can force in partition capacitance formula pressure micro-sensing element 20, and read the capacitance curve 50 that stays on the chip 40 corresponding to this line peak 48 at pressure type fingerprint, just can restore the shape at original fingerprint line peak 48 by the shape that reads capacitance curve 50.
The present invention utilizes the suspension structure design of two stepwises, when allowing the second rank suspension structure make middle body produce maximum displacement because of ambient pressure changes, and then can drive the first rank suspension structure translation, make the whole first rank suspension structure also reach maximum displacement, reaching maximum sense capacitance variable, so the present invention still can keep good sensing sensitivity when reducing the area of sensing element; When sensing element of the present invention extends to the application of fingerprint line peak pressure power sensing, can truly restore fingerprint line peak shape originally, have splendid identification capability.
The above is by embodiment characteristics of the present invention to be described, its purpose is had the knack of this operator and can be understood content of the present invention and implement according to this making, and non-limiting claim of the present invention, so, all other do not break away from equivalence modification or the modification that disclosed spirit is finished, and must be included in the described claim.
In sum, the true tool advance of the present invention, practicality have met the application for a patent for invention important document, so propose application for a patent for invention in accordance with the law.
Claims (6)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 02132054 CN1239893C (en) | 2002-09-10 | 2002-09-10 | Capacitive pressure micro-sensing element and its applied fingerprint reading chip |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 02132054 CN1239893C (en) | 2002-09-10 | 2002-09-10 | Capacitive pressure micro-sensing element and its applied fingerprint reading chip |
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| Publication Number | Publication Date |
|---|---|
| CN1482440A CN1482440A (en) | 2004-03-17 |
| CN1239893C true CN1239893C (en) | 2006-02-01 |
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| CN 02132054 Expired - Fee Related CN1239893C (en) | 2002-09-10 | 2002-09-10 | Capacitive pressure micro-sensing element and its applied fingerprint reading chip |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110553761A (en) * | 2018-05-30 | 2019-12-10 | 苏州明皜传感科技有限公司 | force sensor |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4143653B2 (en) * | 2006-05-24 | 2008-09-03 | オムロン株式会社 | Array type capacitive sensor |
| CN102236460B (en) * | 2010-04-28 | 2013-11-27 | 周正三 | Sensing device, micro touch device and method for manufacturing sensing device |
| TWI463121B (en) * | 2012-04-02 | 2014-12-01 | Htc Corp | Force sensor and tester for sim card contact pins |
| CN105241584A (en) * | 2015-10-14 | 2016-01-13 | 华东光电集成器件研究所 | Capacitive pressure sensor |
| CN105286814A (en) * | 2015-10-16 | 2016-02-03 | 上海磐启微电子有限公司 | Flexible capacitive pulse sensor array |
| CN111044182B (en) * | 2019-12-31 | 2021-12-10 | 上海交通大学 | Force/moment adjustable sensor and manufacturing method |
| CN113109747B (en) * | 2021-06-15 | 2021-09-28 | 西南交通大学 | A kind of superconducting magnetic levitation micro levitation force rapid testing device and testing method |
-
2002
- 2002-09-10 CN CN 02132054 patent/CN1239893C/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110553761A (en) * | 2018-05-30 | 2019-12-10 | 苏州明皜传感科技有限公司 | force sensor |
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| CN1482440A (en) | 2004-03-17 |
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