WO2009066992A2 - Capacitive sensor - Google Patents
Capacitive sensor Download PDFInfo
- Publication number
- WO2009066992A2 WO2009066992A2 PCT/MY2008/000158 MY2008000158W WO2009066992A2 WO 2009066992 A2 WO2009066992 A2 WO 2009066992A2 MY 2008000158 W MY2008000158 W MY 2008000158W WO 2009066992 A2 WO2009066992 A2 WO 2009066992A2
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- capacitive sensor
- moisture
- electrodes
- insulating layers
- layers
- Prior art date
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
- G01N27/22—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating capacitance
- G01N27/223—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating capacitance for determining moisture content, e.g. humidity
- G01N27/225—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating capacitance for determining moisture content, e.g. humidity by using hygroscopic materials
Definitions
- the present invention relates to a capacitive sensor, particularly it relates to an improved capacitive sensor for measuring humidity and moisture.
- capacitive moisture sensor comprises of a pair of electrodes with moisture-sensitive material such as polymer or ceramic interposed therebetween.
- the dielectric constant of the material which also the capacitance between the two electrodes varies in response to ambient moisture. Hence, the moisture content can be determined by means of a capacitive measurement.
- the capacitive sensor according to the present invention are defined with two, three, four and five layers of electrodes.
- the combinations of positive and negative electrodes within each porous insulating layers are arranged to be interdigitated to the adjacent layer.
- Figure 1 illustrates one layer electrode interdigitated fingers.
- Figure 2 illustrates multi layers electrode interdigitated fingers with trench.
- Figure 3 illustrates two layers electrode interdigitated fingers with different electrode arrangement: 3(a) without trench; 3(b) with trench; 3(c) without trench; and 3(d) without trench.
- Figure 4 illustrates three layers electrode interdigitated fingers with different electrode arrangement: 4(a) without trench; and 4(b) with trench.
- Figure 5 illustrates four layers electrode interdigitated fingers with different electrode arrangement: 5(a) with trench; and 5(b) without trench.
- Figure 6 illustrates five layers electrode interdigitated fingers with different electrode arrangement: 6(a) with trench; and 6(b) without trench.
- the structure of one-layer electrode interdigitated fingers is shown in Figure 1. It comprises a positive electrode (1) and a negative electrode (2) located between first insulating layer (3) and second insulating layer (4).
- the insulating layers are of porous and moisture-sensitive material preferably polyimide.
- the structure as shown in Figure 2 comprises bulk semiconductor substrate (9), preferably silicon, a multiple insulating layers (22) with a plurality of electrodes and a plurality of trenches (17).
- the interdigitated electrode fingers are arranged into two, three, four and five insulating layers.
- Two layers electrode interdigitated fingers are shown in Figures 3a, 3b, 3c, and 3d with different periodic capacitance clusters, in which Figure 3b having a plurality of trenches (17) separating and enlarging the region of the insulating layer.
- the trenches (17) on the structure allow more water vapour to enter into the underlying layers, thus improving the water vapour absorption.
- This structure is suitable for measuring moisture content in soil.
- the positive and negative electrodes are placed side by side in each layer and arranged to be interdigitated to the adjacent layer.
- the electrodes are arranged at least one pair of either negative or positive electrodes are arranged side by side to each other pair in at least one insulating layer whereby the positive and the negative electrodes in the adjacent insulating layer are arranged side by side.
- FIG. 4 Three, four and five layers of electrode interdigitated finger are shown in Figures 4, 5 and 6 respectively whereby, different number of layers either with or without trenches give different type of cluster capacitance.
- the capacitance is measured with a read-out circuitry in an integrated circuits.
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
Abstract
A capacitive sensor comprises of electrodes interdigitated fingers in multiple insulating layers for measuring moisture content.
Description
Capacitive Sensor
Field of the Invention
The present invention relates to a capacitive sensor, particularly it relates to an improved capacitive sensor for measuring humidity and moisture.
Background of the Invention
In general, capacitive moisture sensor comprises of a pair of electrodes with moisture-sensitive material such as polymer or ceramic interposed therebetween. The dielectric constant of the material which also the capacitance between the two electrodes varies in response to ambient moisture. Hence, the moisture content can be determined by means of a capacitive measurement.
The measurement of humidity and moisture by using capacitive sensor are known. In US6,445,56 and US 6,628,501, there is provided a capacitive sensor using one layer electrodes placed on a membrane and bulk silicon substrate.
Summary of the Invention
It is an object of the present invention to provide an improved capacitive sensor for measuring humidity and moisture with multiple layers of interdigitated electrodes for higher capacitance sensitivity.
The capacitive sensor according to the present invention are defined with two, three, four and five layers of electrodes. The combinations of positive and negative electrodes within each porous insulating layers are arranged to be interdigitated to the adjacent layer.
By having the multiple layer of electrodes in each insulating layer, a deeper and wider penetration area of water vapor absorption capability. Hence, the total capacitance and the sensor sensitivity increase. This type of sensor could measure the water vapor and soil water.
Brief Description of the Drawings
The above description of the present invention is further described by way of example and with reference to the accompanying drawings in which:
Figure 1 illustrates one layer electrode interdigitated fingers.
Figure 2 illustrates multi layers electrode interdigitated fingers with trench.
Figure 3 illustrates two layers electrode interdigitated fingers with different electrode arrangement: 3(a) without trench; 3(b) with trench; 3(c) without trench; and 3(d) without trench.
Figure 4 illustrates three layers electrode interdigitated fingers with different electrode arrangement: 4(a) without trench; and 4(b) with trench.
Figure 5 illustrates four layers electrode interdigitated fingers with different electrode arrangement: 5(a) with trench; and 5(b) without trench.
Figure 6 illustrates five layers electrode interdigitated fingers with different electrode arrangement: 6(a) with trench; and 6(b) without trench.
Detailed Description of the Present Invention
The present invention will now be described more specifically with reference to the following embodiments. It is to be noted that the following descriptions of preferred embodiments of the present invention are presented herein for purpose of illustration and description only.
The structure of one-layer electrode interdigitated fingers is shown in Figure 1. It comprises a positive electrode (1) and a negative electrode (2) located between first insulating layer (3) and second insulating layer (4). The insulating layers are of porous and moisture-sensitive material preferably polyimide. The capacitance between the electrodes and the capacitance between the layers as illustrated in Figure 1 wherein : 12 represents the capacitance between the positive and negative electrodes (1,2) in the first insulating layer (3); 11 represents the capacitance between the electrodes (1,2) in the second insulating layer; 13 represent the capacitance between the electrodes (1,2) in silicon depletion layer (8),; 14 represents the capacitance between positive or negative electrode and ground (10) in the second insulating layer; and 15 represents the capacitance between either one of the electrodes (1,2) and ground in silicon depletion layer (8).
As explained above, it is a preferred embodiment of the present invention to have the electrode interdigitated fingers (16) in multiple insulating layers as shown in Figure 2. The structure as shown in Figure 2 comprises bulk semiconductor substrate (9), preferably silicon, a multiple insulating layers (22) with a plurality of electrodes and a plurality of trenches (17).
By having the structure as shown in Figure 2, the total capacitance and the sensitivity increase. The arrangement of the positive and the
negative electrodes which are interdigitated to each other will automatically construct a periodic capacitance cluster (21). It is to be noted that different arrangements of electrodes will construct a different cluster capacitance. The horizontal double arrows (18, 19) and diagonal arrows shown in Figure 2 represent the capacitance between the positive and the negative electrodes.
In another embodiment, the interdigitated electrode fingers are arranged into two, three, four and five insulating layers. Two layers electrode interdigitated fingers are shown in Figures 3a, 3b, 3c, and 3d with different periodic capacitance clusters, in which Figure 3b having a plurality of trenches (17) separating and enlarging the region of the insulating layer. The trenches (17) on the structure allow more water vapour to enter into the underlying layers, thus improving the water vapour absorption. This structure is suitable for measuring moisture content in soil.
Further, in Figures 3a and 3b, it is shown that the positive and negative electrodes are placed side by side in each layer and arranged to be interdigitated to the adjacent layer. In Figure 3c and 3d, the electrodes are arranged at least one pair of either negative or positive electrodes are arranged side by side to each other pair in at least one insulating layer whereby the positive and the negative electrodes in the adjacent insulating layer are arranged side by side.
Three, four and five layers of electrode interdigitated finger are shown in Figures 4, 5 and 6 respectively whereby, different number of layers either with or without trenches give different type of cluster capacitance. The capacitance is measured with a read-out circuitry in an integrated circuits.
Claims
1. A capacitive sensor for measuring moisture comprising: a semiconductor substrate; a multiple insulating layers; a plurality of electrodes lying between the insulating layers; and a plurality of trenches separating the insulating layers.
2. The capacitive sensor for measuring moisture according to Claim 1 wherein the insulating layers are porous and of moisture-sensitive material having a dielectric constant that varies in response to moisture.
3. The capacitive sensor for measuring moisture according to Claim 2 wherein the moisture-sensitive material is preferably polyimide.
4. The capacitive sensor for measuring moisture according to Claim 1 wherein the electrodes are arranged in each insulating layer to be interdigitated to the adjacent insulating layer.
5. The capacitive sensor for measuring moisture according to Claim 1 wherein the trenches enlarging the insulating materials region for absorbing moisture.
6. A capacitive sensor for measuring moisture comprising: a semiconductor substrate; a multiple insulating layers; and a plurality of electrodes lying between the insulating layers.
7. The capacitive sensor for measuring moisture according to Claim 6 wherein the insulating layers are porous and of moisture-sensitive material having a dielectric constant that varies in response to moisture.
8. The capacitive sensor for measuring moisture according to Claim 7 wherein the moisture-sensitive material is preferably polyimide.
9. The capacitive sensor for measuring moisture according to Claim 8 wherein the electrodes are arranged in each insulating layer to be interdigitated to the adjacent insulating layer.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| MYPI20072088 | 2007-11-23 | ||
| MYPI20072088A MY164505A (en) | 2007-11-23 | 2007-11-23 | Capacitive sensor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| WO2009066992A2 true WO2009066992A2 (en) | 2009-05-28 |
| WO2009066992A3 WO2009066992A3 (en) | 2009-08-20 |
Family
ID=40668026
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/MY2008/000158 WO2009066992A2 (en) | 2007-11-23 | 2008-11-24 | Capacitive sensor |
Country Status (2)
| Country | Link |
|---|---|
| MY (1) | MY164505A (en) |
| WO (1) | WO2009066992A2 (en) |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2336758A1 (en) * | 2009-12-16 | 2011-06-22 | Nxp B.V. | Capacitive sensor |
| WO2012067488A1 (en) * | 2010-11-15 | 2012-05-24 | Mimos Berhad | Humidity sensor and a method for fabricating the same |
| CN102507669A (en) * | 2011-11-18 | 2012-06-20 | 中国科学院上海微系统与信息技术研究所 | Structure improvement and making method of humidity sensor on basis of polyimide and filler corrosion |
| CN103207215A (en) * | 2012-01-16 | 2013-07-17 | 中国科学院上海微系统与信息技术研究所 | Improved humidity sensor based on polyimide |
| US9018060B2 (en) | 2010-06-15 | 2015-04-28 | 3M Innovative Properties Company | Variable capacitance sensors and methods of making the same |
| WO2014185771A3 (en) * | 2013-05-17 | 2015-04-30 | Mimos Berhad | A capacitive humidity sensor |
| EP2988122A1 (en) * | 2014-08-20 | 2016-02-24 | ams international AG | Capacitive sensor |
| WO2016056887A1 (en) * | 2014-10-09 | 2016-04-14 | Mimos Berhad | Humidity sensor with nanoporous polyimide membranes and a method of fabrication thereof |
| EP3037810A1 (en) * | 2014-12-23 | 2016-06-29 | EM Microelectronic-Marin SA | Improved moisture sensor |
| US10921277B2 (en) | 2016-02-18 | 2021-02-16 | Ams Ag | Sensor arrangement and method for generating measurement signals |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4017820A (en) * | 1975-07-25 | 1977-04-12 | Illinois Tool Works Inc. | Humidity sensor with multiple electrode layers separated by a porous monolithic ceramic dielectric structure |
| US20020109959A1 (en) * | 2001-02-15 | 2002-08-15 | Inao Toyoda | Capacitive moisture sensor and fabrication method for capacitive moisture sensor |
| US20050188764A1 (en) * | 2004-02-27 | 2005-09-01 | Denso Corporation | Capacitive type humidity sensor |
| US20060096370A1 (en) * | 2004-11-09 | 2006-05-11 | Denso Corporation | Capacitive humidity sensor |
| US7247271B2 (en) * | 2003-03-14 | 2007-07-24 | Delphi Technologies, Inc. | Compact ceramic sensor for fuel volatility and oxygenate concentration |
-
2007
- 2007-11-23 MY MYPI20072088A patent/MY164505A/en unknown
-
2008
- 2008-11-24 WO PCT/MY2008/000158 patent/WO2009066992A2/en active Application Filing
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4017820A (en) * | 1975-07-25 | 1977-04-12 | Illinois Tool Works Inc. | Humidity sensor with multiple electrode layers separated by a porous monolithic ceramic dielectric structure |
| US20020109959A1 (en) * | 2001-02-15 | 2002-08-15 | Inao Toyoda | Capacitive moisture sensor and fabrication method for capacitive moisture sensor |
| US7247271B2 (en) * | 2003-03-14 | 2007-07-24 | Delphi Technologies, Inc. | Compact ceramic sensor for fuel volatility and oxygenate concentration |
| US20050188764A1 (en) * | 2004-02-27 | 2005-09-01 | Denso Corporation | Capacitive type humidity sensor |
| US20060096370A1 (en) * | 2004-11-09 | 2006-05-11 | Denso Corporation | Capacitive humidity sensor |
Cited By (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2336758A1 (en) * | 2009-12-16 | 2011-06-22 | Nxp B.V. | Capacitive sensor |
| US8963563B2 (en) | 2009-12-16 | 2015-02-24 | Nxp B.V. | Capacitive sensor for detecting the presence of a substance |
| US9018060B2 (en) | 2010-06-15 | 2015-04-28 | 3M Innovative Properties Company | Variable capacitance sensors and methods of making the same |
| WO2012067488A1 (en) * | 2010-11-15 | 2012-05-24 | Mimos Berhad | Humidity sensor and a method for fabricating the same |
| CN102507669A (en) * | 2011-11-18 | 2012-06-20 | 中国科学院上海微系统与信息技术研究所 | Structure improvement and making method of humidity sensor on basis of polyimide and filler corrosion |
| CN103207215A (en) * | 2012-01-16 | 2013-07-17 | 中国科学院上海微系统与信息技术研究所 | Improved humidity sensor based on polyimide |
| WO2014185771A3 (en) * | 2013-05-17 | 2015-04-30 | Mimos Berhad | A capacitive humidity sensor |
| WO2016026771A1 (en) * | 2014-08-20 | 2016-02-25 | Ams International Ag | Capacitive sensor |
| EP2988122A1 (en) * | 2014-08-20 | 2016-02-24 | ams international AG | Capacitive sensor |
| CN106796192A (en) * | 2014-08-20 | 2017-05-31 | ams国际有限公司 | Capacitance type sensor |
| US10274450B2 (en) | 2014-08-20 | 2019-04-30 | Ams International Ag | Capacitive sensor |
| CN106796192B (en) * | 2014-08-20 | 2019-10-29 | ams国际有限公司 | Capacitance type sensor |
| WO2016056887A1 (en) * | 2014-10-09 | 2016-04-14 | Mimos Berhad | Humidity sensor with nanoporous polyimide membranes and a method of fabrication thereof |
| EP3037810A1 (en) * | 2014-12-23 | 2016-06-29 | EM Microelectronic-Marin SA | Improved moisture sensor |
| KR101745215B1 (en) | 2014-12-23 | 2017-06-08 | 이엠. 마이크로일레크트로닉-마린 쏘시에떼 아노님 | Improved humidity sensor |
| US10184911B2 (en) | 2014-12-23 | 2019-01-22 | Em Microelectronic Marin S.A. | Method for manufacturing humidity sensor |
| US10921277B2 (en) | 2016-02-18 | 2021-02-16 | Ams Ag | Sensor arrangement and method for generating measurement signals |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2009066992A3 (en) | 2009-08-20 |
| MY164505A (en) | 2017-12-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| WO2009066992A2 (en) | Capacitive sensor | |
| US10175188B2 (en) | Trench based capacitive humidity sensor | |
| US8963563B2 (en) | Capacitive sensor for detecting the presence of a substance | |
| EP2332095B1 (en) | Surface sensor | |
| US20170138882A1 (en) | Capacitive humidity sensor | |
| US10502702B2 (en) | Capacitor type humidity sensor | |
| CN107290082A (en) | A kind of capacitance type touch sensor | |
| US7710128B2 (en) | Method and apparatus for controlling the sensitivity and value of a capacitive humidity sensor | |
| TW200712998A (en) | Two-dimensional position sensor | |
| EP3208610B1 (en) | Sensor arrangement and method for generating measurement signals | |
| CN101932928B (en) | Improved structure for capacitive balancing of integrated relative humidity sensor | |
| JP2003270189A (en) | Capacitive humidity sensor | |
| JP2004271461A (en) | Capacitance type humidity sensor | |
| US20130098151A1 (en) | Capacitive sensor and method for making the same | |
| CN101004398A (en) | Humidity sensor and semiconductor device including the same | |
| CN102692432A (en) | Integrated humidity sensor and manufacturing method | |
| US8201455B2 (en) | Pressure sensor having thin film sections | |
| WO2016056887A1 (en) | Humidity sensor with nanoporous polyimide membranes and a method of fabrication thereof | |
| KR20150059452A (en) | Pressure sensor and manufacturing method thereof | |
| US20150268757A1 (en) | Cross-shaped touchscreen pattern | |
| CN103698368B (en) | A kind of senser element, sensor and moisture sensor device | |
| WO2012067488A1 (en) | Humidity sensor and a method for fabricating the same | |
| EP3845895A1 (en) | Multi-sensing capacitive sensors | |
| KR101499795B1 (en) | Cantilever humidity sensor using electrostatic force | |
| CN115825171A (en) | Double-capacitance humidity sensor |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 08852909 Country of ref document: EP Kind code of ref document: A2 |
|
| NENP | Non-entry into the national phase in: |
Ref country code: DE |
|
| 122 | Ep: pct application non-entry in european phase |
Ref document number: 08852909 Country of ref document: EP Kind code of ref document: A2 |