NL2011845C2 - A capacitive sensor for humidity and/or ammonia sensing. - Google Patents
A capacitive sensor for humidity and/or ammonia sensing. Download PDFInfo
- Publication number
- NL2011845C2 NL2011845C2 NL2011845A NL2011845A NL2011845C2 NL 2011845 C2 NL2011845 C2 NL 2011845C2 NL 2011845 A NL2011845 A NL 2011845A NL 2011845 A NL2011845 A NL 2011845A NL 2011845 C2 NL2011845 C2 NL 2011845C2
- Authority
- NL
- Netherlands
- Prior art keywords
- capacitive sensor
- electrodes
- dielectric material
- ammonia
- substrate
- Prior art date
Links
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 title claims description 67
- 229910021529 ammonia Inorganic materials 0.000 title claims description 33
- 239000003989 dielectric material Substances 0.000 claims description 40
- 239000000758 substrate Substances 0.000 claims description 26
- 239000011148 porous material Substances 0.000 claims description 16
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 claims description 10
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 7
- 238000005260 corrosion Methods 0.000 claims description 6
- 230000007797 corrosion Effects 0.000 claims description 6
- 238000005259 measurement Methods 0.000 claims description 5
- 229910052782 aluminium Inorganic materials 0.000 claims description 4
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 4
- 229910021426 porous silicon Inorganic materials 0.000 claims description 3
- 239000003990 capacitor Substances 0.000 claims description 2
- 239000010410 layer Substances 0.000 description 10
- 229910010271 silicon carbide Inorganic materials 0.000 description 7
- 238000010438 heat treatment Methods 0.000 description 5
- 239000012528 membrane Substances 0.000 description 5
- 235000012431 wafers Nutrition 0.000 description 5
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 4
- 230000007774 longterm Effects 0.000 description 4
- 229910052751 metal Inorganic materials 0.000 description 4
- 239000002184 metal Substances 0.000 description 4
- 229910052710 silicon Inorganic materials 0.000 description 4
- 239000010703 silicon Substances 0.000 description 4
- 239000004411 aluminium Substances 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 2
- 238000004140 cleaning Methods 0.000 description 2
- 230000009977 dual effect Effects 0.000 description 2
- 239000007772 electrode material Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 230000035945 sensitivity Effects 0.000 description 2
- 238000009529 body temperature measurement Methods 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 239000011247 coating layer Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 230000005494 condensation Effects 0.000 description 1
- 238000009313 farming Methods 0.000 description 1
- 125000004435 hydrogen atom Chemical group [H]* 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 229910003465 moissanite Inorganic materials 0.000 description 1
- 238000005334 plasma enhanced chemical vapour deposition Methods 0.000 description 1
- 238000000623 plasma-assisted chemical vapour deposition Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
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
-
- 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
- G01N27/227—Sensors changing capacitance upon adsorption or absorption of fluid components, e.g. electrolyte-insulator-semiconductor sensors, MOS capacitors
-
- 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
- G01N27/221—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating capacitance by investigating the dielectric properties
- G01N2027/222—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating capacitance by investigating the dielectric properties for analysing gases
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/0004—Gaseous mixtures, e.g. polluted air
- G01N33/0009—General constructional details of gas analysers, e.g. portable test equipment
- G01N33/0027—General constructional details of gas analysers, e.g. portable test equipment concerning the detector
- G01N33/0036—General constructional details of gas analysers, e.g. portable test equipment concerning the detector specially adapted to detect a particular component
- G01N33/0054—Ammonia
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
- Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
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)
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
Description
A capacitive sensor for humidity and/or ammonia sensing
The present invention relates to a capacitive sensor for humidity and/or ammonia sensing comprising: a substrate, a first- and a second- electrode, and a dielectric material permeable to water and ammonia, wherein the first- and second-electrodes and the substrate constitute a capacitance, and wherein the dielectric material is provided on the substrate and separates the first- and second- electrodes.
Such capacitive sensors have been described in the academic literature. See e.g. E.J. Connolly et al., Sensors and Actuators B, 2005, 109, 44.
The basic structure of a capacitive humidity and/or ammonia sensor of the prior art, such as of the above identified document comprises, as sequential layers and from bottom to top: a bottom electrode, a silicon substrate, a porous dielectric material and a top electrode. For the case of humidity sensing, variations in ambient humidity causes die condensation of water vapour in the porous dielectric material, changing its permittivity and therefore the capacitance. For the case of ammonia sensing, it is not yet clear exactly what the sensing mechanism is, but possibly, due to a small voltage applied during capacitance measurements, a thin depletion layer is formed on the surface of the dielectric material. Ammonia ' molecules passing over this depletion layer might be decomposed, and subsequently hydrogen atoms absorb onto this depletion layer, thus changirig the capacitance.
In applications such as pig-farming, automotive and process industry, there is a large market for ammonia and humidity sensors. These can be harsh environments for electronics and at present there are no sensors on the market that have the required long-term reliability.
It is an object of the present invention to provide a capacitive sensor for humidity and/or ammonia that is more reliable, compact and cheaper compared to sensors of the prior art.
In a first aspect, the present invention relates to a capacitive sensor for humidity and/or ammonia sensing comprising: a substrate, a first- and a second- electrode, and a die lectric material permeable to water and ammonia, wherein the first- and second- electrodes and the substrate constitute a capacitance, and wherein the dielectric material is provided on the substrate and separates the first- and second- electrodes, wherein the first and second- electrodes are buried within the dielectric material.
The term buried signifies that the electrodes are not at a surface of the sensor exposed to the direct environment of the sensor, but rather are within and are covered by the dielectric material.
By providing the first- and second- electrodes within the dielectric material, the electrodes are shielded from the environment in which the sensor is.being operated. As a result, the electrodes are less susceptible to corrosion and cheap electrode materials can be used without having consequence for the long-term reliability of the sensor.
Humidity and ammonia sensors of the prior art, such as the sensor of E.J. Connolly et al., Sensors and Actuators B, 2005, 109, 44 have an electrode at an environment-exposed surface thereof; in order to impart reasonable long-term reliability, chemically inert electrode materials are preferably used; these are typically very costly. Furthermore, even if the electrode is chemically inert, electrical connections between the electrode and a circuit of the sensor may be susceptible to corrosion, again resulting in poor long-term reliability of the sensor.
In a preferred embodiment, the dielectric material is porous silicon carbide.
Silicon carbide is well-known to be able to withstand harsh chemical conditions such as those found in the environments in which sensors for humidity and ammonia sensors are required. Furthermore, the inventors have found porous silicon carbide, when used as a dielectric in a capacitive sensing arrangement to be sensitive to the presence of both ammonia gas and humidity.
Silicon carbide can be made porous by e.g. electrochemical etching- of SiC in HF. Adjusting the processing allows the sensitivity to both ammonia and humidity to be tuned e.g. by controlling the pore-size. A preferred dielectric material is low temperature plasma enhanced chemical vapour deposition silicon carbide. Such is fully compatible with CMOS processing and is also low cost.
In a preferred embodiment, the substrate is impermeable to water and ammonia.
Such serves to further protect the first- and second-electrodes from corrosion.
In a preferred embodiment, the first and second electrodes are aluminium electrodes. Aluminium is a low-cost material that can be easily shaped into the correct electrode architecture .
In a preferred embodiment, the thickness of the dielectric material is in the range of 0.1 to 10 μιη and preferably in the range of 0.2 to 1 μιη. Layers of dielectric material having a thickness falling within these ranges have been shown to perform very well when incorporated into capacitive sensors and are compatible with sensor manufacturing processes.
In a preferred embodiment, the dielectric material has a first humidity sensing population of pores having diameters in the range of 1 nm to 100 nm and/or a second ammonia sensing population of pores having diameters in the range of 100 nm to 500 nm. It has been found that for humidity sensing, the reguirements are to have a pore size in the range of 1 nm to 100 nm. Wherein the dielectric material of the sensor has substantially only pores having diameters > 100 nm, an ammonia sensor results. Having first- and second- populations permits the relative sensitivities to ammonia and humidity to be tuned and opens up' the possibility of having a dual sensor. A dual sensor preferably has first- and second- populations of pores in a ratio of 1:1.
In a preferred embodiment, the thickness of the substrate is in the range of 0.1-10 μιη. The substrate is preferably thin in the region of the dielectric material to facilitate cleaning. As an example, heat can be applied via a heating element through the substrate. The heating element may also be used to control the temperature for constant capacitance measurements .
In a preferred embodiment, the first- and second-electrodes are on the substrate. Such facilitates manufacture of the device.
In a preferred embodiment, the first- and second-electrodes extend substantially over a cross-section of the dielectric material. By applying a short pulse of current to the electrodes, the electrodes can serve as a heating element as described above for cleaning the sensor and/or to control the temperature for constant capacitance measurements. Thus a separate heating element does not need to be provided and furthermore the heat will be more effectively transferred to the dielectric material since the electrodes are buried therein.
In a preferred embodiment, a surface of the first-and second- electrodes is provided with a shielding layer for protecting the first- and second- electrodes from corrosion.
In a preferred embodiment, the capacitive sensor further comprises a circuit for determining the capacitance.
In a second aspect, the present invention relates to a humidity and ammonia sensing device comprising at least a first- and a second- capacitive sensor according to the foregoing, wherein a dielectric material of the first capacitive sensor has pores having diameters in the range of 1 to 100 nm and wherein a dielectric material of the second capacitive sensor has pores having diameters in the range of 100 to 500 nm.
The present invention is hereafter further elucidated with reference to the Drawing. The Drawing relates to an exemplary embodiment of the sensor of the invention only and should not be considered to limit the scope of the claims.
Fig. 1 shows a basic structure of a capacitive sensor for humidity and/or ammonia according to the invention.
Fig. 2 shows a preferred electrode configuration.
Fig. 3 shows a preferred embodiment of a capacitive sensor for humidity and/or ammonia according to the invention. '
With reference to Fig. 1, a basic structure of a capacitive sensor for humidity and/or ammonia sensing 1 is shown comprising: a substrate 2, a first- and a second- electrode 3,4, and a dielectric material 5 permeable to water and ammonia, wherein the first- and second- electrodes 3,4 and the substrate 2 constitute a capacitance, and wherein the dielectric material 5 is provided on the substrate 2 and separates the first- and second- electrodes 3,4, wherein the first- and second- electrodes 3,4 are buried within the dielectric mate rial 5.
The electrodes 3,4 are preferably arranged as shown in Fig. 2. This configuration enables the device to be used as a capacitor and also a heating resistor. The two electrodes are in a horizontal plane of the device at an interface with the substrate 2. The first- and second- electrodes 3,4 extend substantially over a cross-section X of the dielectric material 5 as shown in Figures 1 and 3.
The capacitive sensor for humidity and/or ammonia according to the invention 1 is fully compatible with CMOS device structure and technology, and can be incorporated onto standard silicon wafers (the substrate 2) as shown in Fig. 3. The substrate (2) is preferably etched back at the location of the dielectric material 5 to form a membrane having a thickness in the range of 0.1 to 10 pm (i.e. the substrate 2 has a thickness in the range of 0.1 to 10 pm over an interface with the dielectric material). The reason for using a membrane is so that a short current pulse through the electrodes 3,4 would heat the device 1 resulting in a reset to zero. The heater will also be used to control the temperature for constant capacitance measurements. Accurate temperature control can be achieved with the proposed structure since the temperature measurement can be incorporated into the membrane. Ambient temperature will be measured with a second temperature sensor in die bulk silicon. The membrane structure will lead to several advantages over die bulk devices in terms of lower power consumption and functionality. ' In the device shown in Fig. 3, the dielectric materi al 5 is silicon carbide (having a thickness in the range of 0.1 to 10 pm and preferably in the range of 0.2 to 1 pm), the electrodes 3,4 are aluminium electrodes and the substrate 2 is a standard p-type silicon wafer. The basic process is therefore that first the electronics 3,4 are processed on a standard wafer. The metal for the electrodes 3,4 can either be the metal used in the standard IC or an additional metal layer. Silicon carbide is then deposited over the whole wafer. This will form the dielectric material 5 permeable to humidity and ammonia for the device 1 and also a robust coating layer for the electronics. The wafer is then etched back in the areas of the sensor 1 stopping on the SiC and metal. An additional met- al layer is deposited, which will form the counter electrode for porous formation. After porous formation, this layer is removed and a final coating is placed on the back side of the membrane. Optionally, a SiN shielding layer (not shown) is provided on a top-surface only of the electrodes 3,4 as further protection against corrosion.
In the preferred embodiment of the invention shown in Figure 3, the dielectric material 5 has a first humidity sensing population of pores having diameters in the range of 1 nm to 100 nm and a second ammonia sensing population of pores having diameters in the range of 100 nm to 500 nm (in a ratio of 1:1) . This allows a single sensor 1 to be used for detecting both ammonia and humidity. As an alternative, two sensors 1 according to the invention can be incorporated into a humidity and ammonia sensing device wherein a dielectric material 5 of the first capacitive sensor has pores having diameters in the range of 1 to 100 nm and wherein a dielectric material 5 of the second capacitive sensor has pores having diameters in the range of 100 to 500 nm.
Although the invention has been discussed in the foregoing with reference to an exemplary embodiment of the sensor of the invention, the invention is not restricted to this particular embodiment which can be varied in many ways without departing from the gist of the invention. The discussed exemplary embodiment shall therefore not be used to construe the appended claims strictly in accordance therewith. On the contrary the embodiment is merely intended to explain the wording of the appended claims without intent to limit the claims to this exemplary embodiment. The scope of protection of the invention shall therefore be construed in accordance with the appended claims only, wherein a possible ambiguity in the wording of the claims shall be resolved using this exemplary embodiment.
Claims (13)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NL2011845A NL2011845C2 (en) | 2013-11-27 | 2013-11-27 | A capacitive sensor for humidity and/or ammonia sensing. |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NL2011845A NL2011845C2 (en) | 2013-11-27 | 2013-11-27 | A capacitive sensor for humidity and/or ammonia sensing. |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| NL2011845C2 true NL2011845C2 (en) | 2015-06-01 |
Family
ID=50156851
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| NL2011845A NL2011845C2 (en) | 2013-11-27 | 2013-11-27 | A capacitive sensor for humidity and/or ammonia sensing. |
Country Status (1)
| Country | Link |
|---|---|
| NL (1) | NL2011845C2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10005108B2 (en) | 2016-10-17 | 2018-06-26 | Robert Bosch Gmbh | Lens cleaning method for a surveillance camera |
| GB2558044A (en) * | 2016-10-17 | 2018-07-04 | Bosch Gmbh Robert | Capacitive moisture sensor system for a surveillance camera |
| EP3584570A1 (en) * | 2018-06-20 | 2019-12-25 | MEAS France | Method for manufacturing a relative humidity sensor and relative humidity sensor |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6069013A (en) * | 1997-02-01 | 2000-05-30 | Dornier Gmbh | Sensor for the selective detection of ammonia in noX -containing, oxygen-rich gases |
| EP2278309A1 (en) * | 2009-07-21 | 2011-01-26 | Nxp B.V. | A Sensor |
-
2013
- 2013-11-27 NL NL2011845A patent/NL2011845C2/en not_active IP Right Cessation
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6069013A (en) * | 1997-02-01 | 2000-05-30 | Dornier Gmbh | Sensor for the selective detection of ammonia in noX -containing, oxygen-rich gases |
| EP2278309A1 (en) * | 2009-07-21 | 2011-01-26 | Nxp B.V. | A Sensor |
Non-Patent Citations (1)
| Title |
|---|
| CONNOLLY E J ET AL: "A porous SiC ammonia sensor", SENSORS AND ACTUATORS B: CHEMICAL: INTERNATIONAL JOURNAL DEVOTED TO RESEARCH AND DEVELOPMENT OF PHYSICAL AND CHEMICAL TRANSDUCERS, ELSEVIER S.A, CH, vol. 109, no. 1, 24 August 2005 (2005-08-24), pages 44 - 46, XP027810739, ISSN: 0925-4005, [retrieved on 20050824] * |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10005108B2 (en) | 2016-10-17 | 2018-06-26 | Robert Bosch Gmbh | Lens cleaning method for a surveillance camera |
| GB2558044A (en) * | 2016-10-17 | 2018-07-04 | Bosch Gmbh Robert | Capacitive moisture sensor system for a surveillance camera |
| US10274449B2 (en) | 2016-10-17 | 2019-04-30 | Robert Bosch Gmbh | Capacitive moisture sensor system for a surveillance camera |
| GB2558044B (en) * | 2016-10-17 | 2020-06-03 | Bosch Gmbh Robert | Capacitive moisture sensor system for a surveillance camera |
| EP3584570A1 (en) * | 2018-06-20 | 2019-12-25 | MEAS France | Method for manufacturing a relative humidity sensor and relative humidity sensor |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10598621B2 (en) | Gas sensing device with chemical and thermal conductivity sensing | |
| US8747748B2 (en) | Chemical sensor with conductive cup-shaped sensor surface | |
| EP2762866B1 (en) | CMOS gas sensor and method for manufacturing the same | |
| US9588073B2 (en) | Resistive MEMS humidity sensor | |
| EP2203738B1 (en) | Improved structure for capacitive balancing of integrated relative humidity sensor and manufacturing method | |
| EP2554981B1 (en) | Integrated circuit with a gas sensor and method of manufacturing such an integrated circuit | |
| EP2321632A1 (en) | Sensor has combined in-plane and parallel-plane configuration | |
| JP2003270189A (en) | Capacitive humidity sensor | |
| US9506885B2 (en) | Sensor chip | |
| NL2011845C2 (en) | A capacitive sensor for humidity and/or ammonia sensing. | |
| US20040177685A1 (en) | Capacitance type humidity sensor | |
| US20150047430A1 (en) | Integrated humidity sensor and method for the manufacture thereof | |
| JP2010145402A (en) | Gas sensor with field-effect transistor | |
| CN110494744B (en) | Humidity sensor | |
| KR101322354B1 (en) | Humidity sensor, humidity sensing method and transistor therefor | |
| JP2007139447A (en) | Moisture permeability measuring instrument of thin film and moisture permeability measuring method | |
| US9476853B2 (en) | System and method for forming microwells | |
| US8621923B2 (en) | Humidity sensor | |
| US20060055502A1 (en) | Humidity sensor | |
| KR101649605B1 (en) | CMOS humidity sensor and method for manufacturing the same | |
| US10641722B2 (en) | Micromechanical moisture sensor device and corresponding manufacturing method | |
| CN109690301B (en) | Volumetric gas sensor | |
| US20180017521A1 (en) | Semiconductor-Based Gas Sensor Assembly for Detecting a Gas and Corresponding Production Method | |
| Huck et al. | Chemical sensors based on a high-k perovskite oxide of barium strontium titanate | |
| CN104115288A (en) | Infrared light sensor chip with high measurement accuracy and method for producing the infrared light sensor chip |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MM | Lapsed because of non-payment of the annual fee |
Effective date: 20161201 |