CN114778617A - Preparation method of ultra-sensitive MEMS VOCs gas sensor and micro pad printing device used in preparation method - Google Patents
Preparation method of ultra-sensitive MEMS VOCs gas sensor and micro pad printing device used in preparation method Download PDFInfo
- Publication number
- CN114778617A CN114778617A CN202210521750.8A CN202210521750A CN114778617A CN 114778617 A CN114778617 A CN 114778617A CN 202210521750 A CN202210521750 A CN 202210521750A CN 114778617 A CN114778617 A CN 114778617A
- Authority
- CN
- China
- Prior art keywords
- mems
- gas
- sensitive
- sensitive material
- transfer printing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000012855 volatile organic compound Substances 0.000 title claims abstract description 77
- 238000007649 pad printing Methods 0.000 title claims abstract description 55
- 238000002360 preparation method Methods 0.000 title claims abstract description 28
- 239000000463 material Substances 0.000 claims abstract description 142
- 239000000758 substrate Substances 0.000 claims abstract description 76
- 239000002002 slurry Substances 0.000 claims abstract description 56
- 238000000034 method Methods 0.000 claims abstract description 47
- 239000000843 powder Substances 0.000 claims abstract description 38
- 238000000137 annealing Methods 0.000 claims abstract description 33
- 239000000919 ceramic Substances 0.000 claims abstract description 22
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 claims abstract description 22
- 238000004806 packaging method and process Methods 0.000 claims abstract description 22
- 239000003960 organic solvent Substances 0.000 claims abstract description 20
- 229910021627 Tin(IV) chloride Inorganic materials 0.000 claims abstract description 18
- 239000008367 deionised water Substances 0.000 claims abstract description 18
- 229910021641 deionized water Inorganic materials 0.000 claims abstract description 18
- HPGGPRDJHPYFRM-UHFFFAOYSA-J tin(iv) chloride Chemical compound Cl[Sn](Cl)(Cl)Cl HPGGPRDJHPYFRM-UHFFFAOYSA-J 0.000 claims abstract description 18
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 18
- 229920006122 polyamide resin Polymers 0.000 claims abstract description 15
- RMAQACBXLXPBSY-UHFFFAOYSA-N silicic acid Chemical compound O[Si](O)(O)O RMAQACBXLXPBSY-UHFFFAOYSA-N 0.000 claims abstract description 15
- 229910002651 NO3 Inorganic materials 0.000 claims abstract description 13
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 claims abstract description 13
- 239000002270 dispersing agent Substances 0.000 claims abstract description 8
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 65
- 238000010023 transfer printing Methods 0.000 claims description 56
- 238000002156 mixing Methods 0.000 claims description 30
- 239000000725 suspension Substances 0.000 claims description 24
- 239000000203 mixture Substances 0.000 claims description 21
- 239000011259 mixed solution Substances 0.000 claims description 20
- ONDPHDOFVYQSGI-UHFFFAOYSA-N zinc nitrate Chemical compound [Zn+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O ONDPHDOFVYQSGI-UHFFFAOYSA-N 0.000 claims description 20
- 238000003756 stirring Methods 0.000 claims description 18
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 claims description 15
- 238000005520 cutting process Methods 0.000 claims description 11
- 238000001035 drying Methods 0.000 claims description 11
- 238000006243 chemical reaction Methods 0.000 claims description 9
- 239000006185 dispersion Substances 0.000 claims description 9
- 239000007788 liquid Substances 0.000 claims description 9
- 238000005406 washing Methods 0.000 claims description 9
- PTTPXKJBFFKCEK-UHFFFAOYSA-N 2-Methyl-4-heptanone Chemical compound CC(C)CC(=O)CC(C)C PTTPXKJBFFKCEK-UHFFFAOYSA-N 0.000 claims description 8
- PHFQLYPOURZARY-UHFFFAOYSA-N chromium trinitrate Chemical compound [Cr+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O PHFQLYPOURZARY-UHFFFAOYSA-N 0.000 claims description 8
- XTVVROIMIGLXTD-UHFFFAOYSA-N copper(II) nitrate Chemical compound [Cu+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O XTVVROIMIGLXTD-UHFFFAOYSA-N 0.000 claims description 7
- 238000007639 printing Methods 0.000 claims description 7
- KBJMLQFLOWQJNF-UHFFFAOYSA-N nickel(ii) nitrate Chemical compound [Ni+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O KBJMLQFLOWQJNF-UHFFFAOYSA-N 0.000 claims description 6
- 239000002202 Polyethylene glycol Substances 0.000 claims description 5
- 229920001223 polyethylene glycol Polymers 0.000 claims description 5
- RUOJZAUFBMNUDX-UHFFFAOYSA-N propylene carbonate Chemical compound CC1COC(=O)O1 RUOJZAUFBMNUDX-UHFFFAOYSA-N 0.000 claims description 5
- 229920002134 Carboxymethyl cellulose Polymers 0.000 claims description 4
- 229920003171 Poly (ethylene oxide) Polymers 0.000 claims description 4
- 239000004372 Polyvinyl alcohol Substances 0.000 claims description 4
- XBDQKXXYIPTUBI-UHFFFAOYSA-M Propionate Chemical compound CCC([O-])=O XBDQKXXYIPTUBI-UHFFFAOYSA-M 0.000 claims description 4
- 239000001768 carboxy methyl cellulose Substances 0.000 claims description 4
- 235000010948 carboxy methyl cellulose Nutrition 0.000 claims description 4
- 239000008112 carboxymethyl-cellulose Substances 0.000 claims description 4
- UFMZWBIQTDUYBN-UHFFFAOYSA-N cobalt dinitrate Chemical compound [Co+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O UFMZWBIQTDUYBN-UHFFFAOYSA-N 0.000 claims description 4
- 229910001981 cobalt nitrate Inorganic materials 0.000 claims description 4
- 125000001495 ethyl group Chemical group [H]C([H])([H])C([H])([H])* 0.000 claims description 4
- 229920002451 polyvinyl alcohol Polymers 0.000 claims description 4
- 229920000036 polyvinylpyrrolidone Polymers 0.000 claims description 4
- 239000001267 polyvinylpyrrolidone Substances 0.000 claims description 4
- 235000013855 polyvinylpyrrolidone Nutrition 0.000 claims description 4
- 230000008569 process Effects 0.000 abstract description 11
- 238000010923 batch production Methods 0.000 abstract description 3
- 239000007789 gas Substances 0.000 description 172
- 230000004044 response Effects 0.000 description 22
- 230000035945 sensitivity Effects 0.000 description 18
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 15
- 239000000243 solution Substances 0.000 description 15
- 238000001514 detection method Methods 0.000 description 12
- 230000008901 benefit Effects 0.000 description 10
- 239000000428 dust Substances 0.000 description 10
- 238000012546 transfer Methods 0.000 description 10
- 239000004065 semiconductor Substances 0.000 description 9
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 8
- 238000012544 monitoring process Methods 0.000 description 8
- 239000011248 coating agent Substances 0.000 description 6
- 238000000576 coating method Methods 0.000 description 6
- 238000011084 recovery Methods 0.000 description 6
- 238000004140 cleaning Methods 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 5
- 238000006073 displacement reaction Methods 0.000 description 5
- 239000001257 hydrogen Substances 0.000 description 4
- 229910052739 hydrogen Inorganic materials 0.000 description 4
- 238000011056 performance test Methods 0.000 description 4
- 238000011896 sensitive detection Methods 0.000 description 4
- 238000012360 testing method Methods 0.000 description 4
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 3
- 238000011161 development Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000004817 gas chromatography Methods 0.000 description 3
- 229910021389 graphene Inorganic materials 0.000 description 3
- 238000002347 injection Methods 0.000 description 3
- 239000007924 injection Substances 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 2
- 229910002089 NOx Inorganic materials 0.000 description 2
- 229910052581 Si3N4 Inorganic materials 0.000 description 2
- 230000009471 action Effects 0.000 description 2
- 238000005054 agglomeration Methods 0.000 description 2
- 230000002776 aggregation Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 230000001680 brushing effect Effects 0.000 description 2
- 238000002485 combustion reaction Methods 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 239000000446 fuel Substances 0.000 description 2
- 238000002290 gas chromatography-mass spectrometry Methods 0.000 description 2
- 238000001027 hydrothermal synthesis Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 229910021421 monocrystalline silicon Inorganic materials 0.000 description 2
- 239000002086 nanomaterial Substances 0.000 description 2
- 239000003345 natural gas Substances 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 238000007650 screen-printing Methods 0.000 description 2
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 2
- 238000010407 vacuum cleaning Methods 0.000 description 2
- MGWGWNFMUOTEHG-UHFFFAOYSA-N 4-(3,5-dimethylphenyl)-1,3-thiazol-2-amine Chemical compound CC1=CC(C)=CC(C=2N=C(N)SC=2)=C1 MGWGWNFMUOTEHG-UHFFFAOYSA-N 0.000 description 1
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 1
- JBRZTFJDHDCESZ-UHFFFAOYSA-N AsGa Chemical compound [As]#[Ga] JBRZTFJDHDCESZ-UHFFFAOYSA-N 0.000 description 1
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 1
- 206010007269 Carcinogenicity Diseases 0.000 description 1
- 238000005033 Fourier transform infrared spectroscopy Methods 0.000 description 1
- 229910002601 GaN Inorganic materials 0.000 description 1
- 229910001218 Gallium arsenide Inorganic materials 0.000 description 1
- JMASRVWKEDWRBT-UHFFFAOYSA-N Gallium nitride Chemical compound [Ga]#N JMASRVWKEDWRBT-UHFFFAOYSA-N 0.000 description 1
- 238000004566 IR spectroscopy Methods 0.000 description 1
- 206010028980 Neoplasm Diseases 0.000 description 1
- 239000004642 Polyimide Substances 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- XOLBLPGZBRYERU-UHFFFAOYSA-N SnO2 Inorganic materials O=[Sn]=O XOLBLPGZBRYERU-UHFFFAOYSA-N 0.000 description 1
- 230000006978 adaptation Effects 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 150000001299 aldehydes Chemical class 0.000 description 1
- 150000001335 aliphatic alkanes Chemical class 0.000 description 1
- 150000001336 alkenes Chemical class 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- -1 aromatics Chemical class 0.000 description 1
- 239000012298 atmosphere Substances 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 229910002091 carbon monoxide Inorganic materials 0.000 description 1
- 231100000260 carcinogenicity Toxicity 0.000 description 1
- 230000007670 carcinogenicity Effects 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000012459 cleaning agent Substances 0.000 description 1
- 230000003749 cleanliness Effects 0.000 description 1
- 239000003245 coal Substances 0.000 description 1
- 239000003034 coal gas Substances 0.000 description 1
- 238000010411 cooking Methods 0.000 description 1
- TVZPLCNGKSPOJA-UHFFFAOYSA-N copper zinc Chemical compound [Cu].[Zn] TVZPLCNGKSPOJA-UHFFFAOYSA-N 0.000 description 1
- 238000005034 decoration Methods 0.000 description 1
- 238000007598 dipping method Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000003344 environmental pollutant Substances 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000000227 grinding Methods 0.000 description 1
- 230000036541 health Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000004128 high performance liquid chromatography Methods 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 150000002431 hydrogen Chemical class 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 150000002576 ketones Chemical class 0.000 description 1
- 238000001755 magnetron sputter deposition Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000002703 mutagenesis Methods 0.000 description 1
- 231100000350 mutagenesis Toxicity 0.000 description 1
- JCXJVPUVTGWSNB-UHFFFAOYSA-N nitrogen dioxide Inorganic materials O=[N]=O JCXJVPUVTGWSNB-UHFFFAOYSA-N 0.000 description 1
- 239000003921 oil Substances 0.000 description 1
- 150000002894 organic compounds Chemical class 0.000 description 1
- 238000000643 oven drying Methods 0.000 description 1
- 231100000719 pollutant Toxicity 0.000 description 1
- 125000005575 polycyclic aromatic hydrocarbon group Chemical group 0.000 description 1
- 229920001721 polyimide Polymers 0.000 description 1
- 239000002243 precursor Substances 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 238000005067 remediation Methods 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 229910052814 silicon oxide Inorganic materials 0.000 description 1
- 239000000779 smoke Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 231100000331 toxic Toxicity 0.000 description 1
- 230000002588 toxic effect Effects 0.000 description 1
- 238000002834 transmittance Methods 0.000 description 1
Images
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
- G01N27/04—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance
- G01N27/12—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of a solid body in dependence upon absorption of a fluid; of a solid body in dependence upon reaction with a fluid, for detecting components in the fluid
- G01N27/125—Composition of the body, e.g. the composition of its sensitive layer
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B81—MICROSTRUCTURAL TECHNOLOGY
- B81C—PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS
- B81C1/00—Manufacture or treatment of devices or systems in or on a substrate
- B81C1/00349—Creating layers of material on a substrate
- B81C1/00373—Selective deposition, e.g. printing or microcontact printing
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Electrochemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Manufacturing & Machinery (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Investigating Or Analyzing Materials By The Use Of Fluid Adsorption Or Reactions (AREA)
Abstract
The invention relates to the technical field of MEMS gas sensors, in particular to a preparation method of an ultra-sensitive MEMS VOCs gas sensor and a used micro pad printing device, which comprises the following steps: s1, preparing gas-sensitive material powder by using stannic chloride, nitrate, deionized water and a dispersing agent; s2, preparing gas-sensitive material slurry from gas-sensitive material powder, silica sol, polyamide resin and an organic solvent; s3, transferring the gas-sensitive material slurry onto an interdigital electrode of the MEMS, and baking to form a gas-sensitive film; s4, annealing the device; s5, gold wire ball bonding, and ceramic packaging. Firstly, preparing gas-sensitive material powder and gas-sensitive material slurry; transferring the gas-sensitive material slurry to an interdigital electrode of an MEMS substrate through a pad printing process; the MEMS VOCs gas sensor is prepared through annealing treatment, gold wire ball bonding and ceramic packaging, sensitive materials have a small thickness, are firmly combined with interdigital electrodes, have an ultra-sensitive gas-sensitive characteristic, and are a method for the ultra-sensitive MEMS VOCs gas sensor which is strong in applicability and suitable for large-scale batch production.
Description
Technical Field
The invention relates to the technical field of MEMS gas sensors, in particular to a preparation method of an ultra-sensitive MEMS VOCs gas sensor and a used micro pad printing device.
Background
VOCs (volatile Organic compounds) refers to a class of volatile Organic compounds having a boiling point at atmospheric pressure of less than 260 ℃ and a saturated vapor pressure at room temperature of greater than 70.91 Pa. From the perspective of environmental monitoring, VOCs are the generic term for non-methane total hydrocarbon detected by a hydrogen flame ion detector in a gas chromatography, and mainly include alkanes, aromatics, olefins, aldehydes, ketones and other related organic compounds. Most of the VOCs are toxic, and part of the VOCs have carcinogenicity. For example, some benzene and polycyclic aromatic hydrocarbons VOCs in the atmosphere can cause body mutagenesis to generate true tumor, which is harmful to the health of people.
The production of VOCs is mainly derived from fossil energy sources (coal, oil and natural gas) or industries using fossil energy as fuel or raw material and their related chemical industries. Wherein the VOC outdoor is mainly from fuel combustion and transportation; the indoor environment mainly comes from combustion products such as coal and natural gas, smoke of heating and cooking, building and decoration materials, furniture, household appliances, cleaning agents, emission of human bodies and the like.
In 2021, the department of ecological environment in 8 months, issues a notice on accelerating the solution of the current outstanding problem of volatile organic compound control, and proposes to deeply fight against the pollution, prevent and treat attack and fight. The main objective tasks include continuous improvement of environmental remediation, essentially eliminating heavily polluted weather. In terms of pollutant emission index, SO2And NOxIs changed into VOCs and NOx. The development direction of VOCs treatment in China is shifted from the early extensive treatment to the fine and deep treatment. The refinement and advanced treatment of VOCs are very slow in China. As an evaluation mode for VOCs treatment, accurate and continuous VOCs monitoring can be carried out, which is a necessary prerequisite for effectively implementing national VOCs pollution prevention and control planning.
Currently, methods such as Gas Chromatography (GC), gas chromatography-mass spectrometry (GC-MS), gas chromatography-hydrogen flame ionization detection (GC-FID), High Performance Liquid Chromatography (HPLC), fourier infrared spectroscopy (FTIR), and the like are mainly used for detecting and monitoring VOCs. The online gas chromatography-mass spectrometry combined method/hydrogen flame ionization detector method has the advantages of high sensitivity and time resolution, comprehensive species detection and the like, and is an automatic monitoring method mainly used at home and abroad at present. However, the VOCs detection and monitoring method is huge in used equipment, inconvenient to carry about, and also has the problems of long steps of collecting samples and analyzing instruments, difficult rapid detection and the like. In the face of the overall development of the monitoring work of the VOCs, the existing detection and detection means needs to be further improved or a novel detection means needs to be developed to meet the requirements of the current and future rapid detection and monitoring.
The demand of VOCs detection and monitoring equipment miniaturization and rapid detection is met, and MEMS semiconductor gas sensors are produced. Micro-electro-mechanical systems (MEMS) have been combined with classes of semiconductor gas sensors and the like. The developed MEMS semiconductor gas sensor has a series of advantages of small volume, high sensitivity, high response speed and the like. Meanwhile, due to the development and application of technologies such as screen printing, magnetron sputtering and the like in recent years, the industrialization of the MEMS semiconductor gas sensor becomes possible. However, the industrialization of the MEMS semiconductor gas sensor still has some problems to be solved urgently, for example, the MEMS semiconductor gas sensor still has gas cross interference, and the lifetime of the gas sensitive material needs to be further improved. The sensitivity of the MEMS semiconductor gas sensor needs to be further improved for certain specific TVOC detection requirements, and so on.
There are few current patents on ultra-sensitive MEMS VOCs gas sensors. Patent CN107607591B discloses a SnO-based catalyst2An ultra-sensitive toluene gas sensor of a modified NiO nano-structure sensitive material and a preparation method thereof, wherein the method utilizes N-type SnO2The P-type NiO semiconductor sensitive material is modified by the semiconductor material, nano-structure material powder is prepared by a hydrothermal method, a sensitive material film is formed by grinding and dipping, and finally the gas sensor is prepared. The method has the advantages of excellent selectivity and moisture resistance for toluene, ultrahigh sensitivity (60.2-100 ppm) and extremely low detection lower limit (10 ppb). But the preparation method is long, and the low concentration sensitivity is still to be improved. Patent CN111017986A discloses a reduced graphene oxide-CuO/ZnO gas-sensitive materialThe preparation method comprises the steps of mixing the copper-zinc precursor solution and the reduced graphene oxide colloidal solution, carrying out hydrothermal reaction and annealing to obtain the gas sensitive material. The prepared sensor has enhanced selection characteristics for acetone gas in a low-temperature range. However, ammonia gas needs to be continuously introduced in the annealing process, and the addition of graphene oxide enables the response time of the device to be longer, and the sensitivity of only single-component gas is enhanced, so that the application scene is limited.
In order to achieve the quick response of the MEMS VOCs gas sensor and enable the MEMS VOCs gas sensor to be applied to more ultrasensitive application scenes, the invention provides a preparation method of the ultrasensitive MEMS VOCs gas sensor. The porous gas-sensitive material is easy to prepare, the prepared pad printing slurry has good adhesive property, the pad printing process is adopted to replace a screen printing process, the sensitive material has a thin structure, and the prepared MEMS VOCs gas sensor has ultra-sensitive performance and large-scale batch production potential, so that the method for preparing the ultra-sensitive MEMS VOCs gas sensor has high applicability.
Disclosure of Invention
The invention aims to solve the technical problem of how to provide a preparation method of an ultra-sensitive MEMS VOCs gas sensor, which has the advantages of quick response and strong applicability and is suitable for large-scale batch production.
The invention solves the technical problems through the following technical means:
the invention provides a preparation method of an ultra-sensitive MEMS VOCs gas sensor, which comprises the following specific steps:
s1, preparing gas sensitive material powder
Mixing and stirring tin tetrachloride, nitrate and deionized water until the tin tetrachloride, the nitrate and the deionized water are completely dissolved, uniformly mixing the mixed solution and an organic solvent to form a mixed solution, adding a dispersing agent accounting for 0.5-2% of the total mass of the mixed solution, and uniformly stirring; then transferring the obtained dispersion liquid into a reaction kettle, standing for 6-18h at the temperature of 60-100 ℃; finally, centrifugally washing the mixture by using ethanol, and drying the mixture in an oven to obtain gas-sensitive material powder;
s2, preparing gas sensitive material slurry
The gas sensitive material powder prepared by the method comprises the following steps: silica sol: polyamide resin: mixing organic solvents uniformly to form a suspension; then, performing sanding treatment on the suspension to prepare gas-sensitive material slurry;
s3 transfer printing interdigital electrode
Transferring the prepared gas-sensitive material slurry to an interdigital electrode of an MEMS micro-heater substrate by using a micro pad printing device, and completely covering the interdigital electrode; and after the transfer printing is finished, baking in an oven so as to form a gas-sensitive film on the MEMS micro-heater substrate.
S4 annealing treatment of device
And placing the MEMS substrate printed with the sensitive material slurry in a muffle furnace for annealing, and then cutting to obtain the MEMS sensing chip.
S5, gold wire ball bonding, ceramic packaging
And carrying out gold wire ball bonding and ceramic packaging on the prepared MEMS sensing chip, and finally preparing the MEMS VOCs gas sensor.
Has the beneficial effects that: the powdery gas sensitive material is prepared by mixing, dissolving, reacting and drying raw materials such as stannic chloride, nitrate, deionized water, a dispersing agent and the like; mixing the gas-sensitive material powder with silica sol, polyamide resin, an organic solvent and the like to obtain a suspension, and performing sanding treatment on the suspension to obtain a slurry-shaped gas-sensitive material; transferring the prepared gas-sensitive material slurry to a interdigital electrode of the MEMS micro-heater substrate by using a pad printing process, and baking to form a gas-sensitive film; and annealing and cutting to obtain the MEMS sensing chip, and finally performing gold wire ball bonding and ceramic packaging to obtain the MEMS VOCs gas sensor.
According to the method, a gas-sensitive material is prepared into powder and then prepared into slurry, and then the slurry is printed on an MEMS micro-heater substrate through a pad printing process, so that a gas-sensitive film with a thin structure is formed, and the MEMS VOCs gas sensor with ultra-sensitive performance is prepared; in addition, in the process of preparing the gas-sensitive slurry, the formed suspension is subjected to sanding treatment, so that the agglomeration phenomenon of the gas-sensitive material is effectively prevented, the integrity of the microstructure of the gas-sensitive material is ensured, and the ultra-sensitive performance of the gas-sensitive material is further ensured.
The gas-sensitive material slurry has good bonding performance due to the silica sol, the polyamide resin, the organic solvent and the like, the connection firmness of the gas-sensitive film on the MEMS micro-heater substrate is improved, and the gas-sensitive detection effect is ensured.
After the device is annealed, a porous structure is formed on the gas-sensitive film, so that the specific surface area of the gas-sensitive material is increased, the contact area of gas and the gas-sensitive material is facilitated, and the sensitivity of gas-sensitive detection is further improved.
Preferably, the mass ratio of the tin tetrachloride to the nitrate to the deionized water in the step S1 is 20:8-12: 70.
Preferably, the mass ratio of the three components mixed in step S1 to the organic solvent is 20:50-50: 20.
Preferably, the nitrate in step S1 is one or more of zinc nitrate, nickel nitrate, copper nitrate, chromium nitrate and cobalt nitrate.
Preferably, the organic solvent in step S1 is one or more of ethanol and acetone.
Preferably, the dispersant in step S1 is one or more of polyvinylpyrrolidone 1000, polyethylene glycol, polyvinyl alcohol, polyethylene oxide, and carboxymethyl cellulose.
Preferably, the temperature of the oven drying in the step S1 is 60-80 ℃.
Preferably, the organic solvent in step S2 is one or more of diisobutyl ketone, ethyl triethoxy propionate and propylene carbonate.
Preferably, the mass ratio of the photosensitive material powder, the silica sol, the polyamide resin and the organic solvent in step S2 is 5:1:15: 80.
Preferably, the particle size D90 of the suspension obtained in step S2 after sanding is less than 500 nm.
Preferably, the micro pad printing device in step S3 comprises a base, an intaglio plate, a moving assembly and a transfer assembly, wherein the intaglio plate is engraved with patterns to be printed and coated with sensitive materials, and the intaglio plate and the MEMS substrate are both placed on the base; the transfer printing assembly is driven by the moving assembly to move to the MEMS substrate from the intaglio position, the transfer printing assembly comprises a plane transfer printing head and an alignment camera which are fixedly installed on the moving assembly, sensitive materials on the intaglio are transferred to the MEMS substrate through the transfer printing head, and the alignment camera is used for aligning the transfer printing head with the corresponding positions of the intaglio and the MEMS substrate.
Has the beneficial effects that: when the MEMS substrate is used, the MEMS substrate is placed on the base, the moving assembly is started to enable the pad printing head to move to the position above the intaglio, the position of the pad printing head is compared and adjusted through the alignment camera until the pad printing head is aligned with the intaglio and then moves downwards to dip sensitive materials; and then, continuously controlling the moving assembly to move the pad printing head above the MEMS substrate, comparing and adjusting the position of the pad printing head through the alignment camera until the pad printing head is aligned with the corresponding position of the MEMS substrate, and transferring the sensitive material onto the MEMS substrate by moving downwards to realize high-precision printing of the thin sensitive material.
Preferably, the baking temperature in the step S3 is 60-80 ℃ and the time is 30-40 min.
Preferably, the thickness of the gas-sensitive film after baking in S3 in the step is 1-5 μm.
Preferably, the annealing temperature in the step S4 is 350-450 ℃ and the time is 2-3 h.
The invention also provides a micro pad printing device for preparing the ultra-sensitive MEMS VOCs gas sensor, which comprises a base, a gravure, a moving assembly and a transfer printing assembly, wherein patterns to be printed are engraved on the gravure and sensitive materials are brushed on the gravure, and the gravure and an MEMS substrate are both placed on the base; the transfer printing assembly is driven by the moving assembly to move to the MEMS substrate from the intaglio position and comprises a plane transfer printing head and an alignment camera, the plane transfer printing head and the alignment camera are fixedly installed on the moving assembly, sensitive materials on the intaglio are transferred to the MEMS substrate through the transfer printing head, and the alignment camera is used for aligning the transfer printing head with the intaglio and the corresponding position of the MEMS substrate through comparison.
The invention has the advantages that:
1. according to the method, a gas-sensitive material is prepared into powder and then prepared into slurry, and then the slurry is printed on an MEMS micro-heater substrate through a pad printing process, so that a gas-sensitive film with a thin structure is formed, and the MEMS VOCs gas sensor with ultra-sensitive performance is prepared; in addition, in the process of preparing the gas-sensitive slurry, the formed suspension is subjected to sanding treatment, so that the agglomeration phenomenon of the gas-sensitive material is effectively prevented, the integrity of the microstructure of the gas-sensitive material is ensured, and the ultrasensitive performance of the gas-sensitive material is further ensured.
2. The gas-sensitive material slurry has good bonding performance due to the silica sol, the polyamide resin, the organic solvent and the like, the connection firmness of the gas-sensitive film on the MEMS micro-heater substrate is improved, and the gas-sensitive detection effect is ensured.
3. After the device is annealed, a porous structure is formed on the gas-sensitive film, so that the specific surface area of the gas-sensitive material is increased, the contact area of gas and the gas-sensitive material is facilitated, and the sensitivity of gas-sensitive detection is further improved.
4. This application utilizes the removal subassembly to make the bat seal head move between intaglio and MEMS substrate to compare through counterpoint camera, with this accurate adjustment bat seal head's position, make the bat seal head dip in sensitive material by the intaglio, then on the rendition arrives the MEMS substrate, realize the printing of thin sensitive material high accuracy.
Drawings
Fig. 1 is a schematic view of the overall structure of a micro pad printing apparatus according to embodiment 1 of the present invention.
Fig. 2 is a graph showing the response recovery of the MEMS gas sensor prepared in example 2 of the present invention with respect to 20ppm ethanol.
FIG. 3 is a graph showing the recovery of the response of the MEMS gas sensor prepared in example 2 of the present invention to 1ppm ethanol.
Fig. 4 is a graph showing the sensitivity characteristics of the MEMS gas sensor prepared in example 2 of the present invention.
Description of reference numerals: 1. a base; 11. a base; 12. a support table; 121. a chute; 13. a sample stage; 14. adjusting the bracket; 15. cleaning the roller; 2. intaglio printing; 21. a roller frame; 22. an ink roller; 3. a moving assembly; 31. an X-axis guide rail; 32. a Y-axis guide rail; 33. a Z-axis guide rail; 34. a displacement block; 35. a motor; 4. a transfer assembly; 41. a pad transfer head; 42. aligning a camera; 43. aligning and marking; 5. an MEMS substrate; 6. a negative pressure device; 61. a sample box; 62. A negative pressure dust suction port; 63. a dust collection bag; 64. a vacuum suction nozzle; 65. a heater.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The embodiment of the application discloses a preparation method of an ultra-sensitive MEMS VOCs gas sensor, which comprises the following specific steps:
s1, preparing gas sensitive material powder
Stirring tin tetrachloride, nitrate and deionized water according to the proportion of 20:8-12:70 at the rotating speed of 600rpm until the tin tetrachloride, the nitrate and the deionized water are completely dissolved; then mixing the solution and the organic solvent according to the mass ratio of 20:50-50:20 to form a mixed solution, adding a dispersing agent accounting for 0.5-2% of the total mass of the mixed solution, and stirring at the rotating speed of 600rpm for 30 min; then transferring the obtained dispersion liquid into a reaction kettle, standing for 6-18h at the temperature of 60-100 ℃; and finally, carrying out ethanol centrifugal washing on the mixture, and drying the mixture in an oven at 60-80 ℃ to obtain the gas-sensitive material powder.
Wherein the nitrate is one or a combination of zinc nitrate, nickel nitrate, copper nitrate, chromium nitrate and cobalt nitrate; the organic solvent is one or more of ethanol and acetone; the dispersant is one or more of polyvinylpyrrolidone 1000, polyethylene glycol, polyvinyl alcohol, polyethylene oxide, and carboxymethyl cellulose.
S2, preparing gas sensitive material slurry
The gas sensitive material powder prepared by the method comprises the following steps: silica sol: polyamide resin: uniformly mixing organic solvents according to the mass ratio of 5:1:15:80 to form a suspension; and sanding the suspension, and controlling the granularity D90 to be less than 500nm to prepare the gas-sensitive material slurry.
Wherein the organic solvent is one or more of diisobutyl ketone, ethyl triethoxy propionate and propylene carbonate.
S3 transfer printing interdigital electrode
Transferring the prepared gas-sensitive material slurry to an interdigital electrode of an MEMS micro-heater substrate by using a micro pad printing device, and completely covering the interdigital electrode; after the transfer printing is finished, baking the transfer printing in an oven for 30-40min at the temperature of 60-80 ℃; the thickness of the air-sensitive film after baking is 1-5 μm.
S4 annealing treatment of device
And (3) placing the MEMS substrate printed with the sensitive material slurry in a muffle furnace for annealing at 350-450 ℃ for 2-3h, and finishing cutting after annealing to obtain the MEMS sensing chip.
S5, gold wire ball bonding, ceramic packaging
And performing gold wire ball bonding and ceramic packaging on the prepared MEMS sensing chip to finally prepare the MEMS VOCs gas sensor.
Example 1
The embodiment of the application discloses a preparation method of an ultra-sensitive MEMS VOCs gas sensor, which comprises the following specific steps:
s1 preparation of gas-sensitive material powder
Stirring tin tetrachloride, zinc nitrate, nickel nitrate and deionized water at a ratio of 20:5:5:70 at a rotating speed of 600rpm until the tin tetrachloride, the zinc nitrate, the nickel nitrate and the deionized water are completely dissolved; then mixing the solution and ethanol according to a mass ratio of 50:20 to form a mixed solution, adding polyvinylpyrrolidone 1000 accounting for 1% of the total mass of the mixed solution, and stirring at a rotating speed of 600rpm for 30 min; then transferring the obtained dispersion liquid into a reaction kettle, and standing for 12 hours at the temperature of 80 ℃; and finally, carrying out ethanol centrifugal washing on the mixture, and drying the mixture in an oven at 80 ℃ to obtain the gas-sensitive material powder.
S2, preparing gas-sensitive material slurry
The gas sensitive material powder prepared by the method comprises the following steps: silica sol: polyamide resin: diisobutyl ketone according to the mass ratio of 5:1:15:80, mixing uniformly to form a suspension; and sanding the suspension, and controlling the granularity D90 to be less than 200nm to prepare the gas-sensitive material slurry.
S3 transfer printing interdigital electrode
Transferring the prepared gas-sensitive material slurry to an interdigital electrode of the MEMS micro-heater substrate by using a micro pad printing device, and completely covering the interdigital electrode; after the transfer printing is finished, baking the transfer printing plate in an oven at 80 ℃ for 30 min; the thickness of the gas-sensitive film after baking was 1 μm.
S4 annealing treatment of device
And (3) placing the MEMS substrate printed with the sensitive material slurry in a muffle furnace for annealing at 400 ℃ for 2h, and finishing cutting after annealing to obtain the MEMS sensing chip.
S5, gold wire ball bonding, ceramic packaging
And performing gold wire ball bonding and ceramic packaging on the prepared MEMS sensing chip to finally prepare the MEMS VOCs gas sensor.
The embodiment of the application also discloses a micro pad printing device for preparing the ultra-sensitive MEMS VOCs gas sensor, and as shown in FIG. 1, the micro pad printing device comprises a base 1, an intaglio 2, a moving component 3, a transfer printing component 4, an MEMS substrate 5 and a negative pressure device 6. The base 1 comprises a base 11, a support table 12, a sample table 13 and an adjusting bracket 14. Support bench 12 and regulation support 14 are all fixed connection on base 11, and intaglio 2 is fixed to be placed on support bench 12, and transfer printing subassembly 4 passes through removal subassembly 3 and regulation support 14 sliding connection. The sample stage 13 is slidably disposed on the base 11, and the MEMS substrate 5 is fixedly placed on the sample stage 13. The MEMS substrate 5 is etched with cutting channels to form a plurality of grid units, each grid unit is a chip with an interdigital electrode, and the micro pad printing device is suitable for pad printing operation of 6-8 inches silicon chips.
The gravure plate 2 includes a single crystal silicon wafer and an oxide layer deposited on the surface of the single crystal silicon wafer, and the surface of the oxide layer is etched through a mask to form a pattern to be printed and an alignment mark 43. Wherein, the oxide can be selected from one or more of silicon nitride, gallium arsenide, silicon oxide and gallium nitride, which effectively improves the mechanical strength of the gravure plate 2, and the embodiment is selected as silicon nitride; the thickness of the intaglio plate 2 is 500 μm-2mm, and the thickness of the intaglio plate is 1mm in the embodiment.
The side wall of the supporting table 12 is provided with a sliding chute 121, a roller frame 21 is slidably arranged in the sliding chute 121, the roller frame 21 is positioned at two sides of the intaglio 2, and the top end of the roller frame 21 extends upwards out of the top surface of the intaglio 2. The ink roller 22 is detachably mounted on the roller frame 21, and the ink roller 22 is rotatably connected to the roller frame 21, so that when the roller frame 21 slides along the support base 12, the ink roller 22 rolls on the top surface of the intaglio plate 2, thereby uniformly coating the sensitive material on the intaglio plate 2. When the ink roller 22 with different diameters is replaced or the rotating speed of the ink roller 22 is further controlled by controlling the sliding speed of the roller frame 21, the thickness of the sensitive material can be changed, the structure is simple, and the operation is convenient.
The moving assembly 3 comprises an X-axis guide rail 31, a Y-axis guide rail 32, a Z-axis guide rail 33 and a displacement block 34, wherein the X-axis guide rail 31 and the Y-axis guide rail 32 both adopt screws, and the Z-axis guide rail 33 adopts an air cylinder. The X-axis guide rail 31 is rotatably arranged on the adjusting bracket 14, and the displacement block 34 is sleeved on the X-axis guide rail 31 in a threaded manner; the cylinder main part fixed mounting of Z axle guide rail 33 is on displacement block 34, and the telescopic link downwardly extending of cylinder, transfer printing subassembly 4 fixed mounting are in the bottom of telescopic link. The adjusting bracket 14 is fixedly provided with a motor 35, an output shaft of the motor 35 is fixedly connected with the X-axis guide rail 31, when the motor 35 rotates, the motor 35 drives the X-axis guide rail 31 to rotate, and at the moment, the displacement block 34 is in threaded fit with the X-axis guide rail 31 to horizontally move, so that the transfer printing component 4 is driven to transversely move on a horizontal plane; when the cylinder starts, the Z-axis guide rail 33 drives the transfer printing component 4 to move up and down, so as to adjust the position of the transfer printing component 4.
The Y-axis guide rail 32 is rotatably arranged on the base 11, and the sample table 13 is in threaded connection with the Y-axis guide rail 32. The base 11 is fixedly provided with a motor 35, an output shaft of the motor 35 is fixedly connected with the Y-axis guide rail 32, when the motor 35 rotates, the motor 35 drives the Y-axis guide rail 32 to rotate, and at the moment, the sample stage 13 is in threaded fit with the Y-axis guide rail 32 to move horizontally, so that the MEMS substrate 5 is driven to move longitudinally on the horizontal plane, and the position of the MEMS substrate 5 is adjusted.
The transfer unit 4 includes a pad 41 and an alignment camera 42, and the pad 41 and the alignment camera 42 are both fixedly mounted on the bottom end of the Z-axis guide rail 33. The pad 41 is a planar sheet structure made of polyimide material, which has good flexibility and light transmittance. The alignment camera 42 is a high-definition CCD camera, and is mounted above the pad 41. The center of the top surface of the intaglio plate 2 is etched with an alignment mark 43, the top surface of the corresponding position of the pad printing head 41 is also printed with the alignment mark 43, the alignment mark 43 is cross-shaped, and the pad printing head 41 is aligned with the intaglio plate 2 through the fixed alignment mark 43. Four alignment mark 43 patterns are respectively arranged at corresponding positions of the intaglio 2 and the MEMS substrate 5, the pad printing head 41 dips sensitive materials on the intaglio 2, simultaneously, the alignment mark 43 patterns of the intaglio 2 are printed on the pad printing head 41, when the pad printing head 41 moves to the position above the MEMS substrate 5, the four alignment marks 43 of the pad printing head 41 are aligned with the four alignment marks 43 on the MEMS substrate 5, and therefore, the alignment of the pad printing head 41 and the MEMS substrate 5 is realized.
When in use, after the MEMS substrate 5 and the gravure plate 2 are placed, the sliding roller frame 21 enables the ink roller 22 to roll on the gravure plate 2, so that sensitive materials are uniformly brushed on the gravure plate 2; then starting the motor 35 on the adjusting bracket 14, enabling the transfer printing head 41 to horizontally move to the upper part of the intaglio 2 under the driving action of the X-axis guide rail 31, and simultaneously enabling the alignment mark 43 on the transfer printing head 41 to align with the alignment mark 43 on the intaglio 2 through comparison and observation of the alignment camera 42; then starting the Z-axis guide rail 33 to move the pad printing head 41 downwards and dip sensitive materials on the intaglio plate 2, and simultaneously printing the alignment mark 43 patterns on the intaglio plate 2 on the pad printing head 41; and continuously controlling the X-axis guide rail 31 and the Z-axis guide rail 33 to move the pad printing head 41 above the MEMS substrate 5, and observing through the comparison of the alignment camera 42, starting the motor 35 on the base 11 at the moment, driving the sample table 13 to move back and forth through the Y-axis guide rail 32 until the four alignment marks 43 printed on the pad printing head 41 are aligned with the four alignment marks 43 on the MEMS substrate 5 one by one, and then starting the Z-axis guide rail 33 to move the pad printing head 41 downwards, so that the sensitive material can be transferred onto the MEMS substrate 5, and the high-precision coating of the thin sensitive material is realized.
The base 1 is rotatably provided with a cleaning roller 15, the cleaning roller 15 is positioned between the support platform 12 and the sample platform 13, when the transfer head 41 transfers the sensitive material to the MEMS substrate 5, the transfer head 41 is moved to the position of the cleaning roller 15 through the moving assembly 3, the cleaning roller 15 is rotated to clean the sensitive material remained on the transfer head 41, so that the transfer head 41 is kept clean for the next printing.
The negative pressure device 6 includes a sample tank 61, a negative pressure suction port 62, a dust collection bag 63, a vacuum suction nozzle 64, and a heater 65. The sample box 61 is fixedly arranged on the sample table 13, the vacuum suction nozzles 64 are fixedly arranged on the inner bottom surface of the sample box 61, the number of the vacuum suction nozzles 64 is 4, the MEMS substrate 5 is fixedly adsorbed in the sample box 61 through the vacuum suction nozzles 64, the MEMS substrate 5 is prevented from moving in the pad printing process, and the pad printing effect is further ensured.
The top of the sample box 61 is provided with an opening, and the transfer printing component 4 enters and exits the sample box 61 through the opening to realize the transfer printing of the MEMS substrate 5. The opening and closing cover is slidably provided at the opening position of the sample case 61, and the opening and closing cover of the sample case 61 is kept in a closed state when the transfer unit 4 does not need to enter the sample case 61. The vacuum cleaning port 62 is fixedly installed on the inner side wall of the sample box 61, and a plurality of vacuum cleaning ports 62 are provided, 4 in this embodiment. The small end of the dust collecting bag 63 is communicated with the negative pressure dust suction port 62 through a pipeline, and the large end extends out of the sample box 61. When the transfer printing component 4 does not need to enter the sample box 61, the opening and closing cover keeps a closed state, and meanwhile, the negative pressure dust suction port 62 continuously sucks dust in the sample box 61 and discharges the dust from the dust collection bag 63, so that the cleanliness of the surface of the MEMS substrate 5 is effectively ensured, and the condition that the dust pollutes the MEMS substrate 5 to influence the coating quality is prevented. The heater 65 is installed at the bottom of the sample box 61, and after pad printing is completed, the heater 65 is started to bake the MEMS substrate 5, so that drying of pad-printed sensitive materials is accelerated.
When in use, after the MEMS substrate 5 and the gravure plate 2 are placed, the sliding roller frame 21 enables the ink roller 22 to roll on the gravure plate 2, so that sensitive materials are uniformly brushed on the gravure plate 2; then starting the motor 35 on the adjusting bracket 14, enabling the transfer printing head 41 to horizontally move to the upper part of the intaglio 2 under the driving action of the X-axis guide rail 31, and simultaneously enabling the alignment mark 43 on the transfer printing head 41 to align with the alignment mark 43 on the intaglio 2 through comparison and observation of the alignment camera 42; then the Z-axis guide rail 33 is started to move the pad printing head 41 downwards and dip sensitive materials on the intaglio 2; and continuously controlling the X-axis guide rail 31 and the Z-axis guide rail 33 to move the pad printing head 41 above the MEMS substrate 5, and observing through comparison of the alignment camera 42, starting the motor 35 on the base 11 at the moment, driving the sample table 13 to move back and forth through the Y-axis guide rail 32 until the alignment mark 43 on the pad printing head 41 is aligned with the alignment mark 43 on the MEMS substrate 5, and then starting the Z-axis guide rail 33 to move the pad printing head 41 downwards, so that the sensitive material can be transferred onto the MEMS substrate 5, and high-precision printing of the thin sensitive material and good adaptation between the pad printing head and the sample are realized.
Example 2
The embodiment of the application discloses a preparation method of an ultra-sensitive MEMS VOCs gas sensor, which comprises the following specific steps:
s1, preparing gas sensitive material powder
Stirring tin tetrachloride, zinc nitrate, copper nitrate and deionized water according to the proportion of 20:3:7:70 at the rotating speed of 600rpm until the tin tetrachloride, the zinc nitrate, the copper nitrate and the deionized water are completely dissolved; then mixing the solution and ethanol according to a mass ratio of 50:20 to form a mixed solution, adding polyethylene glycol accounting for 1% of the total mass of the mixed solution, and stirring at a rotating speed of 600rpm for 30 min; then transferring the obtained dispersion liquid into a reaction kettle, and standing for 12 hours at the temperature of 80 ℃; and finally, carrying out ethanol centrifugal washing on the mixture, and drying the mixture in an oven at 80 ℃ to obtain the gas-sensitive material powder.
S2, preparing gas-sensitive material slurry
And (3) mixing the prepared gas-sensitive material powder: silica sol: polyamide resin: diisobutyl ketone according to the mass ratio of 5:1: 10: 85, mixing uniformly to form a suspension; and sanding the suspension, and controlling the granularity D90 to be less than 100nm to prepare the gas-sensitive material slurry.
S3 transfer printing interdigital electrode
Transferring the prepared gas-sensitive material slurry to an interdigital electrode of the MEMS micro-heater substrate by using a micro pad printing device, and completely covering the interdigital electrode; after the transfer printing is finished, baking the transfer printing plate in an oven at 80 ℃ for 30 min; the thickness of the gas-sensitive film after baking was 2 μm.
S4, annealing device
And (3) placing the MEMS substrate printed with the sensitive material slurry in a muffle furnace for annealing at 400 ℃ for 2h, and finishing cutting after annealing to obtain the MEMS sensing chip.
S5, gold wire ball bonding, ceramic packaging
And performing gold wire ball bonding and ceramic packaging on the prepared MEMS sensing chip to finally prepare the MEMS VOCs gas sensor.
Example 3
The embodiment of the application discloses a preparation method of an ultra-sensitive MEMS VOCs gas sensor, which comprises the following specific steps:
s1 preparation of gas-sensitive material powder
Mixing tin tetrachloride, zinc nitrate, chromium nitrate and deionized water according to the weight ratio of 20: 4: 6: stirring at the rotating speed of 600rpm according to the proportion of 70 until the materials are completely dissolved; then mixing the solution and ethanol according to a mass ratio of 50:20 to form a mixed solution, adding polyvinyl alcohol accounting for 1% of the total mass of the mixed solution, and stirring at a rotating speed of 600rpm for 30 min; then transferring the obtained dispersion liquid into a reaction kettle, and standing for 12 hours at the temperature of 80 ℃; and finally, centrifugally washing the mixture by using ethanol, and drying the mixture in an oven at 80 ℃ to obtain the gas-sensitive material powder.
S2, preparing gas sensitive material slurry
The gas sensitive material powder prepared by the method comprises the following steps: silica sol: polyamide resin: and (3) ethyl triethoxy propionate according to the mass ratio of 5:1: 20: 75, uniformly mixing to form a suspension; and sanding the suspension, and controlling the granularity D90 to be less than 300nm to prepare the gas-sensitive material slurry.
S3 transfer printing interdigital electrode
Transferring the prepared gas-sensitive material slurry to an interdigital electrode of the MEMS micro-heater substrate by using a micro pad printing device, and completely covering the interdigital electrode; after the transfer printing is finished, baking the transfer printing plate in an oven at 80 ℃ for 30 min; the thickness of the gas-sensitive film after baking was 3 μm.
S4 annealing treatment of device
And (3) placing the MEMS substrate printed with the sensitive material slurry in a muffle furnace for annealing at 400 ℃ for 2h, and finishing cutting after annealing to obtain the MEMS sensing chip.
S5, gold wire ball bonding, ceramic packaging
And performing gold wire ball bonding and ceramic packaging on the prepared MEMS sensing chip to finally prepare the MEMS VOCs gas sensor.
Example 4
The embodiment of the application discloses a preparation method of an ultra-sensitive MEMS VOCs gas sensor, which comprises the following specific steps:
s1 preparation of gas-sensitive material powder
Mixing tin tetrachloride, zinc nitrate, cobalt nitrate and deionized water according to the weight ratio of 20: 7: 3: stirring at the rotating speed of 600rpm according to the proportion of 70 until the materials are completely dissolved; then mixing the solution and ethanol according to a mass ratio of 50:20 to form a mixed solution, adding polyethylene oxide accounting for 1% of the total mass of the mixed solution, and stirring at a rotating speed of 600rpm for 30 min; then transferring the obtained dispersion liquid into a reaction kettle, and standing for 12 hours at the temperature of 80 ℃; and finally, centrifugally washing the mixture by using ethanol, and drying the mixture in an oven at 80 ℃ to obtain the gas-sensitive material powder.
S2, preparing gas-sensitive material slurry
And (3) mixing the prepared gas-sensitive material powder: silica sol: polyamide resin: diisobutyl ketone and propylene carbonate according to the mass ratio of 5:1: 25: 70, uniformly mixing to form a suspension; and sanding the suspension, and controlling the granularity D90 to be less than 400nm to prepare the gas-sensitive material slurry.
S3 transfer printing interdigital electrode
Transferring the prepared gas-sensitive material slurry to an interdigital electrode of an MEMS micro-heater substrate by using a micro pad printing device, and completely covering the interdigital electrode; after the transfer printing is finished, the substrate is placed in an oven to be baked for 30min at the temperature of 80 ℃. The thickness of the gas-sensitive film after baking was 4 μm.
S4, annealing device
And (3) placing the MEMS substrate printed with the sensitive material slurry in a muffle furnace for annealing at 400 ℃ for 2h, and finishing cutting after annealing to obtain the MEMS sensing chip.
S5, gold wire ball bonding, ceramic packaging
And performing gold wire ball bonding and ceramic packaging on the prepared MEMS sensing chip to finally prepare the MEMS VOCs gas sensor.
Example 5
The embodiment of the application discloses a preparation method of an ultra-sensitive MEMS VOCs gas sensor, which comprises the following specific steps:
s1 preparation of gas-sensitive material powder
Mixing tin tetrachloride, nickel nitrate, copper nitrate and deionized water according to the weight ratio of 20:5:5: stirring at the rotating speed of 600rpm according to the proportion of 70 until the mixture is completely dissolved; then mixing the solution and ethanol according to a mass ratio of 50:20 to form a mixed solution, adding 1% of carboxymethyl cellulose relative to the total mass of the mixed solution, and stirring at a rotating speed of 600rpm for 30 min; then transferring the obtained dispersion liquid into a reaction kettle, and standing for 12 hours at the temperature of 80 ℃; and finally, carrying out ethanol centrifugal washing on the mixture, and drying the mixture in an oven at 80 ℃ to obtain the gas-sensitive material powder.
S1, preparing gas sensitive material powder
The gas sensitive material powder prepared by the method comprises the following steps: silica sol: polyamide resin: diisobutyl ketone and propylene carbonate according to the mass ratio of 5:1: 20: 75, uniformly mixing to form a suspension; and sanding the suspension, and controlling the granularity D90 to be less than 500nm to prepare the gas-sensitive material slurry.
S3 transfer printing interdigital electrode
Transferring the prepared gas-sensitive material slurry to an interdigital electrode of the MEMS micro-heater substrate by using a micro pad printing device, and completely covering the interdigital electrode; after the transfer printing is finished, the film is placed in an oven and baked for 30min at the temperature of 80 ℃, and the thickness of the baked gas-sensitive film is 5 mu m.
S4, annealing device
And (3) placing the MEMS substrate printed with the sensitive material slurry in a muffle furnace for annealing at 400 ℃ for 2h, and finishing cutting after annealing to obtain the MEMS sensing chip.
S5, gold wire ball bonding, ceramic packaging
And carrying out gold wire ball bonding and ceramic packaging on the prepared MEMS sensing chip, and finally preparing the MEMS VOCs gas sensor.
Comparative example 1
The comparative example of the application provides a preparation method of a MEMS VOCs gas sensor, which is different from the preparation method of the embodiment 2 in that the sensitive material is coated in a brushing way in the step S3, and the preparation method comprises the following specific steps:
s1 preparation of gas-sensitive material powder
Mixing tin tetrachloride, zinc nitrate, copper nitrate and deionized water according to the weight ratio of 20:3:7: stirring at the rotating speed of 600rpm according to the proportion of 70 until the mixture is completely dissolved; then mixing the solution and ethanol according to a mass ratio of 50:20 to form a mixed solution, adding polyethylene glycol accounting for 1% of the total mass of the mixed solution, and stirring at a rotating speed of 600rpm for 30 min; then transferring the obtained dispersion liquid into a reaction kettle, and standing for 12 hours at the temperature of 80 ℃; and finally, centrifugally washing the mixture by using ethanol, and drying the mixture in an oven at 80 ℃ to obtain the gas-sensitive material powder.
S2, preparing gas-sensitive material slurry
The gas sensitive material powder prepared by the method comprises the following steps: silica sol: polyamide resin: diisobutyl ketone according to the mass ratio of 5:1: 10: 85, mixing uniformly to form a suspension; and sanding the suspension, and controlling the granularity D90 to be less than 100nm to prepare the gas-sensitive material slurry.
S3 brush-coating interdigital electrode
Brushing the gas-sensitive material slurry on an interdigital electrode of the MEMS micro-heater substrate, and completely covering the interdigital electrode; after the brush coating is finished, placing the mixture in an oven to bake for 30min at 80 ℃; the thickness of the gas-sensitive film after baking was 2 μm.
S4 annealing treatment of device
And (3) placing the MEMS substrate coated with the sensitive material slurry in a muffle furnace for annealing at 400 ℃ for 2h, and finishing cutting after annealing to obtain the MEMS sensing chip.
S5, gold wire ball bonding, ceramic packaging
And carrying out gold wire ball bonding and ceramic packaging on the prepared MEMS sensing chip, and finally preparing the MEMS VOCs gas sensor.
Gas sensitive Performance test 1
The MEMS VOCs gas sensors packaged in the embodiments 1-5 and the comparative example 1 are subjected to a device gas-sensitive performance test. The gas-sensitive performance of the device is tested by using a source surface level multi-channel gas-sensitive test platform (SMP-4) developed by solid physics of the institute of fertilizer-merging materials science of Chinese academy of sciences. Wherein the multimeter/dc power supply (agilent U3606A and U8002A) provides a voltage source and collects voltage signals.
Gas or steam with different concentrations is injected into the testing cavity from the injection port, two rotating fans with 300rpm are symmetrically distributed near the gas injection port, the gas in the cavity can be uniformly mixed within 0.1 second, and the resistance of the device can be changed due to the gas injection, so that the voltage change is reflected in the circuit.
Signals were controlled and acquired using LabVIEW software at a rate of 20 times/second. The tests were all carried out at a relative humidity of 60% RH at room temperature of 25 c, and the test results are shown in table 1.
Table 1 gas sensitive performance test results for sensors in examples 1-5
According to the results in Table 1, the sensors of examples 1-5 each had a higher sensitivity to ethanol than comparative example 1, and had a shorter response time to both 20ppm and 1ppm of ethanol than comparative example 1, indicating that the gas sensitive material slurry was printed on the interdigitated electrodes by pad printing, and that the sensors were prepared with better sensitivity to VOCs gases and response speed than brush coating.
The MEMS VOCs gas sensor prepared in example 2 has the highest sensitivity to 20ppm ethanol, and then example 1, example 3, example 4, and example 5 are performed in this order. According to the analysis of each parameter in the preparation steps of the sensor, the sensitivity is in negative correlation with the granularity of the gas-sensitive material slurry, namely the lower the particle size of the gas-sensitive material slurry is, the higher the sensitivity to VOCs gas is.
The sensor prepared in example 2 has the least response time to 20ppm ethanol, 2.24s, which shows that the smaller the particle size of the gas sensitive material slurry, the stronger the response strength and recovery to the VOCs gas. The response time of the sensor to 1ppm ethanol is as minimum as 8.13s, and then the sensor is sequentially provided with the example 1, the example 3, the example 4 and the example 5, which shows that the response intensity and the recovery property to low-concentration VOCs gas are stronger when the granularity of the gas sensitive material slurry is smaller.
In addition, the recovery curves of the response of the MEMS VOCs gas sensor prepared in example 2 to 20ppm ethanol are shown in FIG. 2, and the recovery curves of the response to 1ppm ethanol are shown in FIG. 3. The response capabilities of the prior art commercial MEMS VOCs gas sensor GM-502B to 1ppm and 20ppm ethanol are shown in Table 1. Through comparison, the response time of the sensor prepared in example 2 to 20ppm and 1ppm ethanol is shorter than that of the existing commercial sensor, which shows that the sensor prepared in the application has the advantage of quick response and has a quick response speed to low-concentration VOCs gas.
Gas sensitive performance test 2 for device
The MEMS VOCs gas sensor prepared in example 2 was used to monitor ethanol, acetone, toluene, methane, hydrogen, carbon monoxide, and nitrogen dioxide, and a sensitivity characteristic curve was plotted, and the result is shown in fig. 4 (in the figure, the abscissa and ordinate are logarithmic values, and the higher the curve deviates from 1, the stronger the response). As can be seen from FIG. 4, the sensor has strong response to ethanol, toluene and acetone, and has the advantages of high sensitivity to VOCs and wide application range. The sensor has strong response to low-concentration ethanol, toluene and acetone, and shows that the sensor has high sensitivity to the response of low-concentration VOCs, namely has super sensitivity.
The use principle and the advantages are as follows: firstly, preparing gas-sensitive material powder and gas-sensitive material slurry; then transferring the gas-sensitive material slurry to an interdigital electrode of the MEMS micro-heater substrate by a pad printing process; and finally, annealing, gold wire ball bonding and ceramic packaging to obtain the MEMS VOCs gas sensor. The MEMS VOCs gas sensor prepared based on the steps has the advantages that the sensitive material has a small thickness, is firmly combined with the interdigital electrode, has an ultra-sensitive gas-sensitive characteristic, has the potential of large-scale mass production, and is an ultra-sensitive MEMS VOCs gas sensor method with high applicability.
The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (10)
1. A preparation method of an ultra-sensitive MEMS VOCs gas sensor is characterized by comprising the following steps: the method comprises the following specific steps:
s1, preparing gas sensitive material powder
Mixing and stirring tin tetrachloride, nitrate and deionized water until the tin tetrachloride, the nitrate and the deionized water are completely dissolved, uniformly mixing the mixed solution and an organic solvent to form a mixed solution, adding a dispersing agent accounting for 0.5-2% of the total mass of the mixed solution, and uniformly stirring; then transferring the obtained dispersion liquid into a reaction kettle, standing for 6-18h at the temperature of 60-100 ℃; finally, centrifugally washing the mixture by using ethanol, and drying the mixture in an oven to obtain gas-sensitive material powder;
s2, preparing gas sensitive material slurry
The gas sensitive material powder prepared by the method comprises the following steps: silica sol: polyamide resin: mixing organic solvents uniformly to form a suspension; then sanding the suspension to prepare gas-sensitive material slurry;
s3 transfer printing interdigital electrode
Transferring the prepared gas-sensitive material slurry to an interdigital electrode of the MEMS micro-heater substrate by using a micro pad printing device, and completely covering the interdigital electrode; and after the transfer printing is finished, baking in an oven so as to form a gas-sensitive film on the MEMS micro-heater substrate.
S4 annealing treatment of device
And placing the MEMS substrate printed with the sensitive material slurry in a muffle furnace for annealing, and then cutting to obtain the MEMS sensing chip.
S5, gold wire ball bonding, ceramic packaging
And performing gold wire ball bonding and ceramic packaging on the prepared MEMS sensing chip to finally prepare the MEMS VOCs gas sensor.
2. The method for preparing an ultra-sensitive MEMS VOCs gas sensor according to claim 1, wherein the method comprises the following steps: the mass ratio of the stannic chloride to the nitrate to the deionized water in the step S1 is 20:8-12: 70; the mass ratio of the three components to the organic solvent after mixing is 20:50-50: 30.
3. The method of claim 1, wherein the method comprises the following steps: in the step S1, the nitrate is one or more of zinc nitrate, nickel nitrate, copper nitrate, chromium nitrate and cobalt nitrate.
4. The method for preparing an ultra-sensitive MEMS VOCs gas sensor according to claim 1, wherein the method comprises the following steps: the organic solvent in the step S1 is one or a combination of ethanol and acetone; the dispersant is one or more of polyvinylpyrrolidone 1000, polyethylene glycol, polyvinyl alcohol, polyethylene oxide and carboxymethyl cellulose.
5. The method for preparing an ultra-sensitive MEMS VOCs gas sensor according to claim 1, wherein the method comprises the following steps: the organic solvent in the step S2 is one or more of diisobutyl ketone, ethyl triethoxy propionate and propylene carbonate.
6. The method for preparing an ultra-sensitive MEMS VOCs gas sensor according to claim 1, wherein the method comprises the following steps: in the step S2, the mass ratio of the photosensitive material powder, the silica sol, the polyamide resin and the organic solvent is 5:1:15: 80; the granularity D90 of the suspension after sanding in the step S2 is not more than 500 nm.
7. The method of claim 1, wherein the method comprises the following steps: the micro pad printing device in the step S3 comprises a base, a gravure plate, a moving assembly and a transfer printing assembly, wherein the gravure plate is engraved with patterns to be printed and is coated with sensitive materials, and the gravure plate and the MEMS substrate are both placed on the base; the transfer printing assembly is driven by the moving assembly to move to the MEMS substrate from the intaglio position, the transfer printing assembly comprises a plane transfer printing head and an alignment camera which are fixedly installed on the moving assembly, sensitive materials on the intaglio are transferred to the MEMS substrate through the transfer printing head, and the alignment camera is used for aligning the transfer printing head with the corresponding positions of the intaglio and the MEMS substrate.
8. The method for preparing an ultra-sensitive MEMS VOCs gas sensor according to claim 1, wherein the method comprises the following steps: in the step S3, the baking temperature is 60-80 ℃, and the baking time is 30-40 min; the thickness of the air-sensitive film after baking is 1-5 μm.
9. The method of claim 1, wherein the method comprises the following steps: the annealing temperature in the step S4 is 350-450 ℃, and the time is 2-3 h.
10. A micro pad printing apparatus for making an ultra sensitive MEMS VOCs gas sensor as claimed in any one of claims 1 to 9 wherein: the printing device comprises a base, a gravure plate, a moving assembly and a transfer printing assembly, wherein patterns to be printed are engraved on the gravure plate, sensitive materials are coated on the gravure plate, and the gravure plate and an MEMS substrate are both placed on the base; the transfer printing assembly is driven by the moving assembly to move to the MEMS substrate from the intaglio position, the transfer printing assembly comprises a plane transfer printing head and an alignment camera which are fixedly installed on the moving assembly, sensitive materials on the intaglio are transferred to the MEMS substrate through the transfer printing head, and the alignment camera is used for aligning the transfer printing head with the corresponding positions of the intaglio and the MEMS substrate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210521750.8A CN114778617A (en) | 2022-05-13 | 2022-05-13 | Preparation method of ultra-sensitive MEMS VOCs gas sensor and micro pad printing device used in preparation method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210521750.8A CN114778617A (en) | 2022-05-13 | 2022-05-13 | Preparation method of ultra-sensitive MEMS VOCs gas sensor and micro pad printing device used in preparation method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114778617A true CN114778617A (en) | 2022-07-22 |
Family
ID=82437356
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210521750.8A Pending CN114778617A (en) | 2022-05-13 | 2022-05-13 | Preparation method of ultra-sensitive MEMS VOCs gas sensor and micro pad printing device used in preparation method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114778617A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115365200A (en) * | 2022-10-24 | 2022-11-22 | 南通飞海电子科技有限公司 | Automatic label transfer printing equipment |
| CN115406944A (en) * | 2022-08-17 | 2022-11-29 | 安徽维纳物联科技有限公司 | Preparation method of carbon dioxide gas sensor and prepared gas sensor |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103995025A (en) * | 2014-05-16 | 2014-08-20 | 上海师范大学 | Printed type graphene-based NO2 gas-sensitive element and preparation method thereof |
| CN110752309A (en) * | 2019-10-10 | 2020-02-04 | 恩利克（浙江）智能装备有限公司 | Foldable flexible transparent anode and manufacturing method thereof |
| CN113109308A (en) * | 2021-04-13 | 2021-07-13 | 哈尔滨理工大学 | Preparation and detection method of VOCs gas sensor array |
| CN113321526A (en) * | 2021-05-28 | 2021-08-31 | 深圳顺络电子股份有限公司 | Sacrificial slurry preparation material, preparation method thereof and preparation method of gas sensor |
| CN114400106A (en) * | 2021-12-27 | 2022-04-26 | 深圳顺络电子股份有限公司 | Insulating layer slurry preparation material, insulating layer preparation method and gas sensor |
-
2022
- 2022-05-13 CN CN202210521750.8A patent/CN114778617A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103995025A (en) * | 2014-05-16 | 2014-08-20 | 上海师范大学 | Printed type graphene-based NO2 gas-sensitive element and preparation method thereof |
| CN110752309A (en) * | 2019-10-10 | 2020-02-04 | 恩利克（浙江）智能装备有限公司 | Foldable flexible transparent anode and manufacturing method thereof |
| CN113109308A (en) * | 2021-04-13 | 2021-07-13 | 哈尔滨理工大学 | Preparation and detection method of VOCs gas sensor array |
| CN113321526A (en) * | 2021-05-28 | 2021-08-31 | 深圳顺络电子股份有限公司 | Sacrificial slurry preparation material, preparation method thereof and preparation method of gas sensor |
| CN114400106A (en) * | 2021-12-27 | 2022-04-26 | 深圳顺络电子股份有限公司 | Insulating layer slurry preparation material, insulating layer preparation method and gas sensor |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115406944A (en) * | 2022-08-17 | 2022-11-29 | 安徽维纳物联科技有限公司 | Preparation method of carbon dioxide gas sensor and prepared gas sensor |
| CN115365200A (en) * | 2022-10-24 | 2022-11-22 | 南通飞海电子科技有限公司 | Automatic label transfer printing equipment |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN114778617A (en) | Preparation method of ultra-sensitive MEMS VOCs gas sensor and micro pad printing device used in preparation method | |
| Tong et al. | WO3 thin film prepared by PECVD technique and its gas sensing properties to NO2 | |
| Kaur et al. | Highly sensitive NO2 sensor based on ZnO nanostructured thin film prepared by SILAR technique | |
| US7705376B2 (en) | Sensor and method of manufacturing the same | |
| US10802008B2 (en) | Bimetal doped-metal oxide-based chemical sensors | |
| CN110823965B (en) | Room temperature detection NO2Preparation method of gas sensitive material | |
| CN110412087B (en) | Isopropanol gas sensor based on nanocube material and preparation method thereof | |
| CN106053548A (en) | Preparation and application of Pd-doped SnO2-oxide-semiconductor CO sensor | |
| CN107966479B (en) | Pd/W for improving performance of hydrogen sensor18O49Method for preparing composite material | |
| CN110887874A (en) | Based on perovskite Cs2PdBr6Humidity-sensitive sensor and preparation method and application thereof | |
| CN105092652A (en) | Tin-doped photocatalysis formaldehyde sensing material, preparation method thereof and formaldehyde sensor | |
| Zhou et al. | NO2 sensing properties of WO3 porous films with honeycomb structure | |
| Bobkov et al. | Study of gas-sensitive properties of zinc oxide nanorod array at room temperature | |
| Du et al. | Aerobic and anaerobic H2 sensing sensors fabricated by diffusion membranes depositing on Pt-ZnO film | |
| Gao et al. | Synthesis of Cr2O3 nanoparticle-coated SnO2 nanofibers and C2H2 sensing properties | |
| Cao et al. | Structural Characterization of Pd‐doped SnO2 Thin Films Using XPS | |
| Wang et al. | A highly sensitive ppb-level H 2 S gas sensor based on fluorophenoxy-substituted phthalocyanine cobalt/rGO hybrids at room temperature | |
| CN114839231A (en) | Anti-interference gas-sensitive coating for semiconductor combustible gas sensor and preparation method and application thereof | |
| CN114166900A (en) | Fishbone-shaped perovskite-based Cs2TeI6Nitric oxide sensor and preparation method and application thereof | |
| CN109638164B (en) | SnO for water treatment 2 Thin film and preparation method of perovskite solar cell thereof | |
| CN111017985A (en) | Preparation method of CuO/ZnO-based semiconductor acetone gas-sensitive material | |
| CN106349248B (en) | A kind of Metalloporphyrins and its preparation method and application | |
| Zhang et al. | Enhanced performances of WO3-based hydrogen sensors with an amorphous SiO2 layer working at low temperatures | |
| CN102830139B (en) | Preparation method for zinc oxide thick-film gas sensitivity sensor with acetone selectivity characteristic | |
| Macagnano et al. | A smart nanofibrous material for adsorbing and detecting elemental mercury in air |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |