CN115592127A - High-precision ceramic-based interdigital electrode with three-lamination structure and manufacturing method thereof - Google Patents

Abstract

The invention provides a high-precision ceramic-based interdigital electrode with a three-lamination structure and a manufacturing method thereof, wherein a ceramic substrate is pretreated; uniformly coating a layer of sacrificial layer material on the surface of the pretreated ceramic substrate, and curing the coated sacrificial layer; printing a conductive core layer of the interdigital electrode on a sacrificial layer which is coated and paved on a ceramic substrate by using high-temperature nano conductive silver paste as a printing material according to the shape and parameters of a designed geometrical pattern of the interdigital electrode; carrying out pre-curing treatment, carrying out sintering treatment on the ceramic substrate and the conductive core layer on the sacrificial layer thereof in a vacuum or inert gas atmosphere, and carrying out post-treatment on the sintered interdigital electrode of the ceramic substrate; depositing an anti-oxidation layer or a reaction layer on the conductive core layer of the interdigital electrode; depositing or coating a modification layer on the anti-oxidation layer or the reaction layer; and carrying out post-treatment on the interdigital electrode. The invention can realize the high-efficiency and low-cost manufacture of the ultra-high precision ceramic-based interdigital electrode.

Description

High-precision ceramic-based interdigitated electrode with triple-layer structure and its manufacturing method

technical field

The invention belongs to the technical field of micro-nano additive manufacturing, and in particular relates to a high-precision ceramic-based interdigital electrode with a three-layer structure and a manufacturing method thereof.

Background technique

The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

Interdigitated electrodes (micro interdigitated electrodes) refer to electrodes with periodic patterns in the shape or comb-like surface. It is an ultra-fine circuit prepared by micro-nano manufacturing process. Its structure is simple and easy to mass-produce, and its size is small and its response is sensitive. , and can quickly establish a stable signal in the detection and is widely used in various sensors and detection in the fields of biomedicine, environment, soil water quality, food safety, public safety and so on. According to the different substrates used, interdigital electrodes are usually divided into: ceramic-based interdigital electrodes, flexible substrate interdigital electrodes, silicon-based interdigital electrodes, etc. Compared with other types of interdigitated electrodes, ceramic-based interdigitated electrodes have many unique advantages, and are suitable for the detection of electrochemical properties of gases and liquids in extreme environments such as high temperature, high pressure, strong acid, and strong alkali.

As the requirements for detection accuracy, sensitivity, response speed, and signal-to-noise ratio become higher and higher, higher and higher requirements are put forward for high-precision ceramic-based interdigital electrodes, which require the finger width (line width) of the interdigital electrode, The finger distance (spacing) is getting smaller and smaller, and the finger thickness is getting bigger and bigger. Unlike silicon-based, glass and other substrates, the surface of ceramic-based substrates is usually rough and has poor flatness. Existing micro-nano manufacturing technologies (thin-film technology, thick-film technology, laser direct imaging LDI, etc.) are difficult to achieve high-precision (fine line width and line spacing) and large-thickness micro-interdigital electrode manufacturing on ceramic substrates, especially for High-precision micro-interdigitated electrodes with a line width and line spacing of less than 30 microns and an electrode thickness of more than 5 microns are completely unable to achieve high-efficiency and low-cost manufacturing with existing technologies. For example, the traditional screen printing technology belongs to the thick film circuit technology, which can realize the manufacture of interdigitated electrodes with a large thickness, but the line width and line spacing are usually greater than 50 microns, and it is impossible to achieve high-precision micro-forks with a line width and line spacing of less than 30 microns. Refers to the manufacture of electrodes.

Thin-film circuit technology based on thin-film deposition, photolithography and etching can realize the manufacture of ultra-high-precision (line width and line spacing less than 50 nanometers) interdigitated electrodes, but the thickness of the electrodes is usually several hundred nanometers (maximum 1 micron), even through subsequent processes such as electrochemical deposition/chemical deposition, it is difficult to realize the manufacture of high-precision interdigital electrodes with a thickness of more than 5 microns. Moreover, it requires the ceramic substrate to have a high surface flatness, the manufacturing process of the interdigitated electrodes is complex, the cost is high, the cycle is long, and the production environment is harsh (clean, high temperature, vacuum, etc.), especially the three wastes will be generated during the production process. serious pollution problems.

In summary, the existing ceramic-based interdigital electrode manufacturing technologies (such as thick-film circuits, thin-film circuits, laser direct structuring LDI, inkjet printing, etc.) are still difficult to achieve high-precision and thick-electrode ceramic-based interdigital electrode manufacturing, especially For ultra-high-precision micro-interdigitated electrodes whose line width and line spacing are less than 10 microns, and the electrode thickness is higher than 10 microns, it is impossible to realize the manufacture of such ultra-high-precision ceramic-based interdigitated electrodes.

Contents of the invention

In order to solve the above problems, the present invention proposes a high-precision ceramic-based interdigitated electrode with a three-layer structure and a manufacturing method thereof. The three-layer structure includes a conductive core layer, an anti-oxidation layer, and a surface modification layer, wherein the conductive core The anti-oxidation layer mainly provides high precision and high conductivity for the interdigital electrodes, and also serves as the master mold for the subsequent two layers; the anti-oxidation layer mainly provides protection for the conductive core layer to meet the high temperature and high corrosion environment; the modification layer is mainly through the functional material Increased surface contact further improves interdigital electrode performance. The present invention uses electric field-driven ejection micro-nano 3D printing technology, combined with micro-nano additive manufacturing technologies such as chemical deposition and electrochemical deposition, and the structure of composite interdigitated electrodes, which can realize the manufacture of high-precision ceramic-based interdigitated electrodes, especially to solve the problem of High-efficiency and low-cost manufacturing of ultra-high-precision (finger width and finger pitch less than 10 microns, electrode thickness greater than 10 microns) ceramic-based interdigitated electrodes. It breaks through the deficiencies and limitations of the existing ceramic base interdigitated electrode thick film technology and thin film technology.

According to some embodiments, the present invention adopts the following technical solutions:

A method for manufacturing a high-precision ceramic-based interdigitated electrode with a three-layer structure, comprising the following steps:

(1) pretreating the ceramic substrate;

(2) uniformly coating a layer of sacrificial layer material on the pretreated ceramic substrate surface, and curing the coated sacrificial layer;

(3) According to the geometric pattern shape and parameters of the designed interdigitated electrodes, the high-temperature conductive nano-conductive silver paste is used as the printing material, and the electric field-driven spray deposition micro-nano 3D printing process is used to coat the sacrificial layer on the ceramic substrate. Print the conductive core layer of the interdigitated electrodes;

(4) Pre-cure the conductive core layer of the interdigitated electrodes on the printed ceramic substrate sacrificial layer, and sinter the conductive core layer on the ceramic substrate and its sacrificial layer under vacuum or inert gas atmosphere , remove the sacrificial layer and the organic solvent in the conductive core layer of the interdigitated electrode, and complete the electrochemical treatment of the printed conductive core layer for sintering;

(5) post-processing the ceramic substrate interdigitated electrodes after sintering;

(6) Depositing an anti-oxidation layer or a reaction layer on the conductive core layer of the interdigitated electrodes;

(7) Depositing or coating a modification layer on the anti-oxidation layer or the reaction layer;

(8) Perform post-processing on the interdigitated electrodes.

As an optional implementation, the pretreatment process in the step (1) includes: using physical polishing or chemical methods to process the surface of the ceramic substrate, reducing the surface roughness of the ceramic substrate, and making the ceramic substrate The surface roughness of the ceramic substrate is better than the set value of 0.1 micron, and then, the dirt on the surface of the ceramic substrate is removed by an ultrasonic cleaning process, and finally, the ceramic substrate is dried/dried with nitrogen gas.

As an optional embodiment, in the step (1), the ceramic substrate includes but not limited to aluminum oxide, beryllium oxide, silicon nitride, silicon carbide and aluminum nitride; the thickness of the ceramic substrate is 10 microns-2000 microns.

As an optional implementation manner, the parameters of the interdigitated electrodes in the step (2) include the finger width, finger pitch, finger length and finger thickness of the electrodes.

As an optional embodiment, the sacrificial layer material in the step (2) includes but is not limited to one of the following materials: aqueous coating solution, polydimethylsiloxane (PDMS), polyvinyl alcohol (PVA) As well as materials that improve the surface quality of ceramics and can be removed by high temperatures.

As an optional embodiment, the method of coating the sacrificial layer material in the step (2) includes but is not limited to one of the following processes: spin coating, slit coating, spray coating, pull-up coating, blade coating and cast coating.

The thickness of the sacrificial layer is 500 nanometers-20 microns;

The sacrificial layer curing method includes but not limited to one of the following processes: heating curing, ultraviolet curing, infrared curing and laser curing.

As an optional embodiment, the electric field-driven spray deposition micro-nano 3D printing process in the step (3) is a contact electric field-driven spray deposition micro-nano 3D printing process, a non-contact electric field-driven spray deposition micro-nano 3D printing process or a single Flat electrode electric field driven spray deposition micro-nano 3D printing process.

As an optional embodiment, in the step (3), when the electric field-driven spray deposition micro-nano 3D printing process is used, the printing process parameters of the electric field-driven spray deposition micro-nano 3D printing are controlled, and the accuracy of the printing finger electrode, the printing fork Refers to the precise control of the shape and quality of the electrode. The printing process parameters include at least: the inner diameter of the printing nozzle, voltage, printing speed, printing height and back pressure. According to the printing material and the accuracy and shape of the printing circuit, the optimal printing process window is obtained. .

As a further step, the inner diameter of the printing nozzle is 1 μm-300 μm;

The printing voltage is 300V-3000V;

The printing speed is 5mm/s-100mm/s;

The printing height is 50μm-500μm;

The back pressure is 100kpa-800kpa.

As an optional implementation, in the step (4), the pre-curing of the printed interdigital electrodes includes, but is not limited to, one of the following methods: heat curing, ultraviolet curing, infrared curing and laser curing.

As an optional embodiment, in the step (4), sintering includes but not limited to one of the following processes: oven sintering, vacuum sintering and inert gas sintering.

As an optional embodiment, in the step (4), flow inertness is introduced during the sintering process, and the sacrificial layer material and the organic solvent material in the conductive ink are discharged from the sintering furnace in time, and the sintering temperature is 600°C-2200°C, The sintering time is 10 minutes to 50 minutes.

As an optional embodiment, in the step (4), the conductive core layer of the interdigital electrode is selected from one of silver, copper, and modified liquid metal, and its thickness is 1 micron to 50 microns.

As an optional embodiment, in the step (6), the anti-oxidation layer of the interdigital electrode is one of gold and platinum, and its thickness is 300 nm-2 microns.

As an optional embodiment, in the step (6), the interdigital electrode reaction layer is one of Au, Ag, and Pt, and its thickness is 300 nm-2 microns.

As an optional embodiment, in the step (6), the interdigitated electrode modification layer is a nanoporous metal layer, carbon nanotubes or graphene, including but not limited to nanoporous gold, nanoporous silver and nanoporous copper, which Thickness 50nm-300nm.

As an optional embodiment, in the step (6), the finger width (line width) of the interdigitated electrode is 0.1 micron-50 micron; the finger distance (line distance) is 0.1 micron-50 micron; the electrode thickness is 1 micron-50 Micron; refers to the length of 1 mm-300 mm.

As an optional implementation manner, in the step (6), the interdigitation index of the interdigital electrodes is 2-200 pairs.

A high-precision ceramic-based interdigital electrode with a three-layer structure is prepared by the above method.

Compared with prior art, the beneficial effect of the present invention is:

(1) The present invention realizes high-precision ceramic-based interdigital electrodes (finger width and finger pitch less than 50 microns), especially ultra-high-precision ceramic-based interdigital electrodes with finger width and finger pitch less than 10 microns and finger thickness greater than 10 microns manufacture. At present, except thin film technology (deposition + exposure + development + etching process) has the process capability of manufacturing high-precision ceramic-based circuits with a line width of less than 10 microns, there is no other technology that can realize the manufacture of high-precision ceramic-based circuits with a line width of less than 10 microns. However, thin-film technology is difficult to achieve thick electrodes, usually less than 1 micron thick. The present invention realizes the manufacture of high-precision ceramic-based microcircuits (interdigitated electrodes) by organically combining four strategies. First, by coating a sacrificial layer, the flatness of the ceramic surface is improved on the one hand, resulting in the distribution of polarized charges on the surface of the substrate. It is more uniform and the electric field is more stable, so that the printing quality, especially the consistency of the micro-circuit printed on large-size substrates, on the other hand, the sacrificial layer is a hydrophobic material, which can help to improve the accuracy of the subsequent printed circuit; subsequently, use High-temperature nano-conductive silver paste, using electric field-driven spray deposition micro-nano 3D printing, realizes the manufacture of high-precision fine interdigitated electrode conductive core layer (electric field-driven spray deposition micro-nano 3D printing has the process capability of sub-micro scale and nano-scale feature printing), Realize the printing of the conductive core layer of the interdigitated electrode at the microscale or even submicroscale; then, through the high-temperature sintering process, the fine circuit shrinkage of the conductive core layer of the printed interdigitated electrode (removal of the organic solvent in the nano-conductive silver paste) further improves the printing accuracy. Finger electrode precision (reducing line width); the present invention realizes the manufacture of high-precision ceramic-based interdigital electrode conductive core layer through the organic collection of these strategies; finally, deposits and oxidizes on the surface of the interdigital electrode conductive core layer by electroless plating or electroplating process The metal layer (or reaction layer) and the modification layer further improve the precision, sensitivity, stability and quality of the ceramic-based interdigital electrode.

(2) The manufacturing method of the present invention has the outstanding advantages of low manufacturing cost and high productivity. The present invention is mainly through the combined process of coating sacrificial layer, micro-nano 3D printing, high-temperature sintering in vacuum/inert gas atmosphere, chemical plating/electroplating, etc., which has low production cost, short process flow and high production efficiency; especially the electric field-driven spraying Deposit the conductive core layer of the interdigital electrode of the micro-nano 3D manufacturing circuit, and deposit the oxide metal layer (or reaction layer) and the organic combination of the modification layer on the surface of the conductive core layer of the interdigital electrode through electroless plating or electroplating to realize high-precision ceramic-based interdigital electrodes Efficient manufacturing to meet the requirements of large-scale production.

(3) The traditional method of manufacturing high-precision ceramic-based interdigitated electrodes based on thin-film circuits, on the one hand, more than 90% of the copper is eventually wasted; on the other hand, it is necessary to use expensive lithography equipment, sputtering equipment, etc. The production conditions such as clean room, vacuum and high temperature are also relatively harsh for the production environment, resulting in very high production costs. The present invention effectively overcomes the high cost problem of traditional manufacturing methods; the material utilization rate of the present invention exceeds 95%, while the existing In processes such as lithography and etching, more than 95% of materials are wasted.

(4) The printed interdigitated electrode has high bonding strength with the ceramic substrate.

(5) In the manufacturing process of the present invention, there is little waste liquid, waste gas, waste residue, etc., and there is little environmental pollution, which belongs to green manufacturing; the traditional method of manufacturing high-precision ceramic-based interdigitated electrodes based on thin-film technology will produce a large amount of waste liquid , waste gas, waste residue, etc., and the environmental pollution is serious, which seriously restricts the wide application of this technology.

(6) The invention organically combines technologies such as ceramic substrate coating sacrificial layer, electric field-driven spray deposition micro-nano 3D printing, electroless plating/micro-electroplating, etc., and realizes high-efficiency and low-cost large-scale manufacturing of large-scale high-precision ceramic-based interdigitated electrodes , providing a disruptive technical solution for the manufacture and mass production of high-precision ceramic-based interdigitated electrodes.

(7) The present invention overcomes the deficiencies and defects of the manufacturing technology of existing ceramic-based microcircuits, the deficiencies of thick film technology, thin film technology, LDI, etc., and can constantly realize that the finger width and finger pitch are less than 10 microns, and the electrode thickness is greater than 10 microns. Micron ultra-high-precision ceramic-based interdigitated electrode manufacturing; and also has the outstanding advantages of low production cost, high efficiency, good process adaptability, and green manufacturing.

(8) The present invention provides a ceramic-based high-precision interdigitated electrode with good electrical conductivity, stable electrical signal baseline, strong anti-interference ability, and multiple uses. Refers to the electrode.

(9) The present invention adopts a composite structure strategy, using silver and copper as the conductive core layer of the interdigitated electrodes. Gold and platinum are used as the anti-oxidation metal layer. After the anti-oxidation metal layer is in contact with the sample to be tested and the environment, it can maintain the stability of its properties without being oxidized or corroded. The anti-oxidation metal layer can prevent the conductive metal core layer from being directly exposed to the sample to be tested and the test environment, ensuring that the conductive metal core layer can work stably for a long time. This kind of interdigitated electrode with composite structure makes the interdigitated electrode not only have high chemical stability but also has a wide detection range and sufficient service life, and can effectively avoid the distortion of the interdigitated electrode signal transmission, so that Therefore, the detection object has a lower detection limit, and the sensitivity and accuracy of the sensor are improved.

(10) The present invention modifies the interdigital electrodes by using carbon nanotubes, graphene, etc., and utilizes the characteristics of the large specific surface area and good electrical conductivity of the modified materials, which can not only increase the adsorption of the interdigital electrodes to the test object, but also Its good electrical characteristics can also improve the sensitivity of interdigital electrodes or sensors, and reduce the detection limit of the measured object.

In order to make the above-mentioned objects, features and advantages of the present invention more comprehensible, preferred embodiments will be described in detail below together with the accompanying drawings.

Description of drawings

The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention, and the schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations to the present invention.

Figure 1 is a process flow chart of the method for manufacturing high-precision ceramic-based interdigitated electrodes based on electric field-driven spraying micro-nano 3D printing provided by the present invention.

Fig. 2 is a schematic diagram of the method for manufacturing high-precision ceramic-based interdigitated electrodes based on electric-field-driven spraying micro-nano 3D printing provided by Embodiment 1 of the present invention.

Fig. 3 is a schematic diagram (a) and a real photo (b) of the structure of the high-precision ceramic-based interdigitated electrode provided by Embodiment 1 of the present invention.

Among them, 101, ceramic substrate, 102, water-based coating solution, 103, conductive silver paste, 104, printing nozzle, 105, sacrificial layer, 105, interdigitated electrode, 107, plating solution, 108, conductive core layer of interdigitated electrode, 109, interdigitated electrode oxidation-resistant metal (gold) layer, 110, interdigitated electrode modification layer.

201, a ceramic substrate, 202, an interdigitated electrode.

detailed description

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

It should be noted that the following detailed description is exemplary and intended to provide further explanation of the present invention. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

It should be noted that the terminology used here is only for describing specific embodiments, and is not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly dictates otherwise, the singular is intended to include the plural, and it should also be understood that when the terms "comprising" and/or "comprising" are used in this specification, they mean There are features, steps, operations, means, components and/or combinations thereof.

A method for manufacturing high-precision ceramic-based interdigitated electrodes based on electric field-driven spray micro-nano 3D printing, including the following processes:

Step 1: Pretreatment of the ceramic substrate (substrate, substrate, matrix). First of all, for the surface treatment of the ceramic substrate, the surface of the ceramic substrate is processed by physical polishing, chemical and other methods to reduce the surface roughness of the ceramic substrate, so that the surface roughness of the ceramic substrate is better than 0.1 micron; then , remove dirt and oil stains on the surface of the ceramic substrate through an ultrasonic cleaning process; finally, perform drying/nitrogen blow-drying treatment on the ceramic substrate.

Step 2: Spread the sacrificial layer. A layer of sacrificial layer material is evenly spread on the surface of the pretreated ceramic substrate, and the coated sacrificial layer is cured.

Step 3: Print the conductive core layer of the interdigitated electrodes. According to the geometric pattern shape of the designed interdigitated electrode, the parameters of the electrode finger width, finger distance, finger length, and finger thickness (electrode thickness); select high-temperature conductive nano-conductive silver paste as the printing material, and use electric field-driven spraying to deposit micro-nano 3D In the printing process, the conductive core layer of the interdigitated electrode is printed on the sacrificial layer coated on the ceramic substrate. Using the sacrificial layer spread in step 2, on the one hand, the accuracy and consistency of the printed interdigital electrodes can be improved, especially the stability of the entire printing process can be improved, and the quality of the printed interdigital electrodes can be improved.

Step 4: Sintering the conductive core layer of the electrode. First, pre-cure the conductive core layer of the interdigitated electrode on the sacrificial layer of the printed ceramic substrate; then, place the conductive core layer on the ceramic substrate and its sacrificial layer in a high-temperature sintering furnace for sintering treatment, according to Optimized sintering process curve and sintering parameters (sintering temperature, time, sintering curve, vacuum degree, etc.), carry out vacuum (or inert gas atmosphere) high-temperature sintering, during the vacuum (or inert gas atmosphere) high-temperature sintering process, the sacrificial layer is completely At the same time, the organic solvent in the conductive core layer of the printed interdigitated electrode is completely removed to complete the conductive sintering electrochemical treatment of the printed conductive core layer. During the sintering process, the conductive core layer of the interdigitated electrode shrinks, which further reduces the line width and improves the density of the conductive core layer. Use the constraints of the sacrificial layer to overcome defects such as fracture and separation of the conductive core layer after sintering due to inconsistent shrinkage between the printed conductive core layer and the ceramic substrate; finally, the interdigitated electrode conductive core layer and the ceramic substrate are sintered into one body, which greatly improves The bonding strength between the conductive core layer of the interdigitated electrodes and the ceramic substrate was improved.

Step 5: Post-sintering treatment. Post-processing the sintered ceramic substrate interdigital electrodes at least includes cleaning, drying and air-drying treatment, so that residues and dirt remaining on the ceramic substrate and interdigital electrodes during the sintering process can be completely removed.

Step 6: Depositing an anti-oxidation metal layer (or reaction layer). An anti-oxidation layer (or reaction layer) is deposited on the conductive core layer of the interdigitated electrode by chemical deposition (electroless plating) or electrochemical deposition (electroplating) process.

Step 7: Depositing a finishing layer. A modification layer is deposited or coated on the anti-oxidation layer (or reaction layer).

Step 8: Post-processing. The interdigitated electrodes after electroless deposition (electroless plating) or electrochemical deposition (electroplating) are post-treated, cleaned with deionized water, completely removing residual impurities and plating solution on the plated parts, and blown or dried with inert gas.

In some embodiments, in step 1, the ceramic substrate includes but not limited to aluminum oxide, beryllium oxide, silicon nitride, silicon carbide, and aluminum nitride. The thickness of the ceramic substrate is 10 microns-2000 microns.

In some embodiments, in step 2, the material of the sacrificial layer includes but is not limited to one of the following materials: water-based coating solution, polydimethylsiloxane (PDMS), polyvinyl alcohol (PVA), and ceramics that can improve Surface quality and can be removed by high temperature material.

In some embodiments, in step 2, the method of coating the sacrificial layer material includes but is not limited to one of the following processes: spin coating, slit coating, spray coating, pull-up coating, knife coating and casting coating cloth.

In some embodiments, in step 2, the thickness of the sacrificial layer is 500 nanometers-20 microns;

In some embodiments, in step 2, the curing method of the sacrificial layer includes, but is not limited to, one of the following processes: heating curing, ultraviolet curing, infrared curing, laser curing, and the like.

In some embodiments, in step 3, the electric field-driven spray deposition micro-nano 3D printing process adopts: contact electric field-driven spray deposition micro-nano 3D printing process, non-contact electric field-driven spray deposition micro-nano 3D printing process or single plate electrode electric field Driving jet deposition micro-nano 3D printing process.

In some embodiments, in step 3, by controlling the printing process parameters of electric field-driven spray deposition micro-nano 3D printing, the precision of printed interdigital electrodes, the shape and quality of printed interdigital electrodes are precisely controlled, and the printing process parameters at least include: Inner diameter size, voltage, printing speed, printing height and back pressure of printing nozzles (printing nozzles include but not limited to stainless steel nozzles, Musashi nozzles, glass nozzles, silicon nozzles and plastic nozzles), according to printing materials and printing circuit accuracy and shape to get the optimal printing process window.

In some embodiments, in step 3, the inner diameter of the printing nozzle is 1μm-300μm; the printing voltage is 300V-3000V; the printing speed is 5mm/s-100mm/s; the printing height is 50μm-500μm; the back pressure is 100kpa-800kpa.

In some embodiments, in step 4, the pre-curing of the printed interdigital electrodes includes, but is not limited to, one of the following methods: heat curing, ultraviolet curing, infrared curing, laser curing, and the like.

In some embodiments, in step 4, sintering includes but not limited to one of the following processes: oven sintering, vacuum sintering and inert gas sintering.

In some embodiments, during the sintering process, flow inert is introduced, and the sacrificial layer material and the organic solvent material in the conductive ink are discharged from the sintering furnace in time, the sintering temperature is 600°C-2200°C, and the sintering time is 10 minutes-50 minutes.

In some embodiments, in step 5, the drying method includes but not limited to heating oven drying.

In some embodiments, in step 5, the cleaning solution used for cleaning is deionized water, and the air-drying gas is inert gas.

In some embodiments, the conductive core layer of the interdigitated electrode is selected from one of silver, copper, and modified liquid metal, and its thickness is 1 μm-50 μm.

In some embodiments, in step 6, the anti-oxidation layer of the interdigital electrode is one of gold and platinum. Its thickness is 300nm-2 microns.

In the step 6, in some embodiments, the interdigital electrode reaction layer is one of Au, Ag, and Pt. Its thickness is 300nm-2 microns.

In some embodiments, in step 7, the interdigitated electrode modification layer is a nanoporous metal layer, carbon nanotube or graphene, including but not limited to nanoporous gold, nanoporous silver and nanoporous copper. Its thickness is 50nm-300nm.

In some embodiments, the finger width (line width) of the interdigitated electrode is 0.1 micron-50 micron; the finger distance (line distance) is 0.1 micron-50 micron; the electrode thickness is 1 micron-50 micron; the finger length is 1 mm-300 mm .

In some embodiments, the fork index of the interdigitated electrodes is 2-200 pairs.

The specific structural features of the high-precision ceramic-based interdigitated electrode prepared by the present invention include a ceramic substrate, a conductive core layer, an anti-oxidation metal layer (reaction layer), and a modification layer. Among them, the conductive core layer is generally made of silver and copper materials. Silver and copper have low resistivity. Using these two metals to make interdigitated electrodes can effectively improve the sensitivity of the sensor and improve the reliability of the detection results. However, metals such as silver and copper with low resistivity are relatively active in chemical properties, and are easy to react with air or strong oxidizing components in the sample to be tested, causing the interdigital electrode to be corroded and disconnected or an oxide film is formed on the surface, resulting in damage to the interdigital electrode . Materials such as gold and platinum have high stability and are suitable for detecting samples of any nature. However, the resistivity of gold and platinum materials is high, and the electrical signal is prone to attenuation and distortion when transmitted through interdigitated electrodes and lines composed of gold and platinum, resulting in low accuracy of detection results, slow sensor response time, and insufficient detection limit.

Therefore, the present invention adopts the composite strategy of conductive core layer + anti-oxidation layer, and uses silver and copper as the conductive core layer of the interdigitated electrodes. Gold and platinum are used as the anti-oxidation metal layer. After the anti-oxidation metal layer is in contact with the sample to be tested and the environment, it can maintain the stability of its properties without being oxidized or corroded. The anti-oxidation metal layer can prevent the conductive metal core layer from being directly exposed to the sample to be tested and the test environment, ensuring that the conductive metal core layer can work stably for a long time.

This kind of interdigitated electrode with composite structure makes the interdigitated electrode not only have high chemical stability but also has a wide detection range and sufficient service life, and can effectively avoid the distortion of the interdigitated electrode signal transmission, so that Therefore, the detection object has a lower detection limit, and the sensitivity and accuracy of the sensor are improved.

In addition, by further modifying the composite interdigitated electrode with materials such as carbon nanotubes and graphene, the large specific surface area and good electrical conductivity of the modified material can not only increase the adsorption of the interdigitated electrode to the test object, but also Its good electrical characteristics can also improve the sensitivity of interdigital electrodes or sensors, and reduce the detection limit of the measured object.

In order to make the specific solution of the present invention more clear to those skilled in the art, two typical embodiments are described below.

In the case of no conflict, the embodiments and the features in the embodiments of the present invention can be combined with each other.

Embodiment one

This example is based on the micro-nano 3D printing technology of contact electric field-driven jet deposition, and selects conductive silver paste to print a conductive pattern structure on the ceramic substrate. 5 μm interdigitated electrodes. Concrete preparation steps include:

Step 1: Ceramic substrate pretreatment. Use a polishing wheel to polish the ceramic sheet for 5 minutes, put the polished ceramic sheet in an ultrasonic cleaner for 10 minutes to remove dirt and oil on the surface of the ceramic substrate, use deionized water as the cleaning solution, and finally use nitrogen to dry the ceramic sheet. The ceramic sheet is made of 95 alumina ceramics with a size of 20mm×20mm×1mm.

Step 2: Coating the sacrificial layer with a water-based coating liquid. Place the ceramic sheet 101 on the KW-4A glue homogenizer, suck up 3ml of the water-based coating solution 102 with a rubber dropper, and evenly drop it on the ceramic sheet, so that the water-based coating solution is evenly spin-coated on the surface of the ceramic sheet. The parameters of the homogenizer are set at a speed of 2000r/min and a time of 45s. After spin-coating, the ceramic sheet was placed in a vacuum drying oven, and the setting parameters were a temperature of 70°C and a curing time of 10 minutes.

Step 3: Print the conductive core layer of the interdigitated electrodes.

The conductive core layer of interdigitated electrodes was printed using a contact electric field-driven spray deposition micro-nano 3D printer.

Specific process:

(1) Pretreatment. Use CAD drawing software to draw the interdigital electrode structure, the interdigital width is 10 μm, the interdigital length is 5 mm, the interdigital spacing is 10 μm, and the number of interdigital pairs is 50. Use the three-dimensional relief design software to convert the CAD graphic structure into data codes and input them into the printer. Place the ceramic substrate coated with the sacrificial layer on the printing platform, and turn on the printer.

(2) Print the interdigitated electrode structure. The conductive silver paste is ss-8060 high-temperature conductive silver paste from Shanghai Xinlui Electronic Materials. The printing nozzle is a glass nozzle with an inner diameter of 30 μm. Set the printer parameters, the printing speed is 5mm/s, the printing voltage is 1000V, the printing air pressure is 0.2Mpa, the printing height is 60μm, and the number of printing layers is 2 layers.

(3) Interdigitated electrodes are pre-cured. The printed interdigital electrodes 106 are placed in a vacuum drying oven, and the curing temperature is set at 70° C., and the curing time is 20 minutes.

Step 4: Sintering the conductive core layer of the interdigitated electrode. Set the heating time of the high-temperature atmosphere furnace to 120 minutes, raise the temperature from 25°C to 880°C, and set the holding time to 30 minutes. The pre-cured ceramic-based interdigitated electrodes were placed in a high-temperature atmosphere furnace heated to 880°C for sintering for 25 minutes. During the sintering process, the sacrificial layer is completely removed, and the organic solvent in the silver paste is completely removed.

Step 5: Post-sintering treatment. The sintered ceramic-based interdigital electrodes were cleaned with deionized water for 5 min, and then dried with nitrogen gas to remove dust and dirt remaining on the ceramic substrate and interdigital electrodes.

Step 6: Depositing an anti-oxidation metal (gold) layer. The electroless gold plating tank is cleaned; the gold plating solution is put into the chemical plating tank, and the composition of the chemical gold plating solution includes: gold fulminate (main salt), anhydrous sodium sulfite (complexing agent), dipotassium hydrogen phosphate (conductive salt and pH buffer agent), potassium citrate (auxiliary complexing agent), EDTA-2Na (masking agent); the plating bath was heated to 45° C., and the ceramic-based interdigitated electrode was immersed in the electroless gold plating bath for 30 minutes. Finally, the plated ceramic-based interdigitated electrodes were removed, cleaned with deionized water for 20 minutes, and the residual chemical plating solution was cleaned, and the ceramic-based interdigitated electrodes were blown dry with nitrogen gas.

Step 7: Depositing a finishing layer. Clean the electroplating tank; put the electroplating solution into the electroplating tank, the main component of the electroplating solution is graphene oxide; put the ceramic-based interdigitated electrode that deposits the anti-oxidation metal (gold) layer into the electroplating solution, and set the electroplating current to 0.5A , plating time 2min.

Step 8: Post-processing. Use deionized water to clean the ceramic-based interdigitated electrode after depositing the anti-oxidation metal (gold) layer and the modified layer for 30 minutes to completely remove the remaining impurities on the plating solution and plated parts, and finally dry the interdigitated electrode with nitrogen.

Example 2

In this example, based on the micro-nano 3D printing technology of contact electric field-driven jet deposition, conductive silver paste is selected to print a conductive pattern structure on a ceramic substrate. 6 μm interdigitated electrodes. Concrete preparation steps include:

Step 1: Ceramic substrate pretreatment. Use a polishing wheel to polish the ceramic sheet for 5 minutes, put the polished ceramic sheet in an ultrasonic cleaner for 10 minutes to remove dirt and oil on the surface of the ceramic substrate, use deionized water as the cleaning solution, and finally use nitrogen to dry the ceramic sheet. The ceramic sheet is made of aluminum nitride ceramics with a size of 25mm×25mm×1mm.

Step 2: Apply a sacrificial layer. Place the ceramic sheet on the KW-4A glue homogenizer, use the rubber dropper to absorb 5ml of water-based coating solution, and drop it evenly on the ceramic sheet, so that the water-based coating is also evenly spin-coated on the surface of the ceramic sheet. The parameters of the homogenizer are set at a speed of 2500r/min and a time of 35s. After spin-coating, the ceramic sheet was placed in a vacuum drying oven, and the setting parameters were a temperature of 70°C and a curing time of 10 minutes.

Step 3: Print the conductive core layer of the interdigitated electrodes.

The conductive core layer of interdigitated electrodes was printed using a contact electric field-driven spray deposition micro-nano 3D printer.

Specific process:

(4) Pretreatment. Use CAD drawing software to draw the interdigital electrode structure, the interdigital width is 20 μm, the interdigital length is 5 mm, the interdigital spacing is 20 μm, and the number of interdigital pairs is 50. Use the three-dimensional relief design software to convert the CAD graphic structure into data codes and input them into the printer. Place the ceramic substrate coated with the sacrificial layer on the printing platform, and turn on the printer.

(5) Print the interdigitated electrode structure. The conductive silver paste is selected from Zhongke Natong NT-TL20E conductive silver paste. The printing nozzle is a glass nozzle with an inner diameter of 40 μm. Set the printer parameters, the printing speed is 5mm/s, the printing voltage is 1000V, the printing air pressure is 0.2Mpa, the printing height is 60μm, and the number of printing layers is 2 layers.

(6) Interdigitated electrodes are pre-cured. Place the printed interdigital electrodes in a vacuum drying oven, set the curing temperature to 70°C, and the curing time to 20 minutes.

Step 4: Sintering the conductive core layer of the interdigitated electrode. Set the heating time of the high-temperature atmosphere furnace to 120 minutes, raise the temperature from 25°C to 880°C, and set the holding time to 30 minutes. The pre-cured ceramic-based interdigitated electrodes were placed in a high-temperature atmosphere furnace heated to 880°C for sintering for 25 minutes. During the sintering process, the sacrificial layer is completely removed, and the organic solvent in the silver paste is completely removed.

Step 5: Post-sintering treatment. The sintered ceramic-based interdigital electrodes were cleaned with deionized water for 5 min, and then dried with nitrogen gas to remove dust and dirt remaining on the ceramic substrate and interdigital electrodes.

Step 6: Depositing an anti-oxidation metal (gold) layer. The electroless gold plating tank is cleaned; the gold plating solution is put into the chemical plating tank, and the composition of the chemical gold plating solution includes: gold fulminate (main salt), anhydrous sodium sulfite (complexing agent), dipotassium hydrogen phosphate (conductive salt and pH buffer agent), potassium citrate (auxiliary complexing agent), EDTA-2Na (masking agent); the plating bath was heated to 45° C., and the ceramic-based interdigitated electrode was immersed in the electroless gold plating bath for 30 minutes. Finally, the plated ceramic-based interdigitated electrodes were removed, cleaned with deionized water for 20 minutes, and the residual chemical plating solution was cleaned, and the ceramic-based interdigitated electrodes were blown dry with nitrogen gas.

Step 7: Depositing a finishing layer. Clean the electroplating pool; put the electroplating solution into the electroplating pool, the main component of the electroplating solution is graphene oxide; put the ceramic-based interdigitated electrode that deposits the anti-oxidation metal (gold) layer into the electroplating solution, and set the electroplating current to 0.6A , plating time 1min.

Step 8: Post-processing. Use deionized water to clean the ceramic-based interdigitated electrode after depositing the anti-oxidation metal (gold) layer and the modified layer for 30 minutes to completely remove the remaining impurities on the plating solution and plated parts, and finally dry the interdigitated electrode with nitrogen.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Within the spirit and principles of the present invention, any modifications, equivalent replacements, improvements, etc. made by those skilled in the art without creative effort shall be included within the protection scope of the present invention.

Claims (10)

1. A method for manufacturing a high-precision ceramic base interdigitated electrode with a three-layer structure, is characterized in that it may further comprise the steps: (1) pretreating the ceramic substrate; (2) uniformly coating a layer of sacrificial layer material on the pretreated ceramic substrate surface, and curing the coated sacrificial layer; (3) According to the geometric pattern shape and parameters of the designed interdigitated electrodes, the high-temperature conductive nano-conductive silver paste is used as the printing material, and the electric field-driven spray deposition micro-nano 3D printing process is used to coat the sacrificial layer on the ceramic substrate. Print the conductive core layer of the interdigitated electrodes; (4) Pre-cure the conductive core layer of the interdigitated electrodes on the printed ceramic substrate sacrificial layer, and sinter the conductive core layer on the ceramic substrate and its sacrificial layer under vacuum or inert gas atmosphere , remove the sacrificial layer and the organic solvent in the conductive core layer of the interdigitated electrode, and complete the electrochemical treatment of the printed conductive core layer for sintering; (5) post-processing the ceramic substrate interdigitated electrodes after sintering; (6) Depositing an anti-oxidation layer or a reaction layer on the conductive core layer of the interdigitated electrodes; (7) Depositing or coating a modification layer on the anti-oxidation layer or the reaction layer; (8) Perform post-processing on the interdigitated electrodes. 2. A method for manufacturing a high-precision ceramic-based interdigitated electrode with a three-layer structure as claimed in claim 1, wherein the pretreatment process in the step (1) includes: using physical polishing or chemical The method is to process the surface of the ceramic substrate to reduce the surface roughness of the ceramic substrate, so that the surface roughness of the ceramic substrate is better than a set value, and then remove the dirt on the surface of the ceramic substrate by an ultrasonic cleaning process, Finally, the ceramic substrate is dried/dried with nitrogen gas. 3. A kind of manufacturing method of the high-precision ceramic-based interdigital electrode with three laminated structures as claimed in claim 1 or 2, is characterized in that, in described step (1), ceramic substrate is aluminum oxide, oxide Beryllium, silicon nitride, silicon carbide or aluminum nitride; Or, the thickness of the ceramic substrate is 10 microns-2000 microns. 4. a kind of manufacturing method of the high-precision ceramic-based interdigital electrode with three laminated structures as claimed in claim 1, is characterized in that, the parameter of interdigital electrode comprises the finger width of electrode in described step (2), Finger distance, finger length and finger thickness; Or, the method of coating the sacrificial layer material in the step (2) is at least one of spin coating, slit coating, spray coating, pull-up coating, blade coating and casting coating; or, The sacrificial layer material is water-based coating liquid, polydimethylsiloxane or polyvinyl alcohol; or The thickness of the sacrificial layer is 500 nanometers-20 microns; or, The curing method of the sacrificial layer is at least one of heating curing, ultraviolet curing, infrared curing and laser curing. 5. A method for manufacturing a high-precision ceramic-based interdigitated electrode with a three-layer structure as claimed in claim 1, wherein the electric field-driven spray deposition micro-nano 3D printing process in the step (3) is a contact Electric field-driven spray deposition micro-nano 3D printing process, non-contact electric field-driven spray deposition micro-nano 3D printing process or single-plate electrode electric field-driven spray deposition micro-nano 3D printing process. 6. A method for manufacturing a high-precision ceramic-based interdigitated electrode with a three-layer structure as claimed in claim 1 or 5, characterized in that, in the step (3), electric field-driven spray deposition of micro-nano 3D During the printing process, control the printing process parameters of electric field-driven spray deposition micro-nano 3D printing, and accurately control the accuracy of the printed interdigital electrodes, the shape and quality of the printed interdigital electrodes. The printing process parameters include at least: the inner diameter of the printing nozzle, the voltage , printing speed, printing height and back pressure, according to the printing material and the accuracy and shape of the printing circuit, the optimal printing process window is obtained. 7. A method for manufacturing a high-precision ceramic-based interdigitated electrode with a three-layer structure as claimed in claim 6, wherein: The inner diameter of the printing nozzle is 1μm-300μm; The printing voltage is 300V-3000V; The printing speed is 5mm/s-100mm/s; The printing height is 50μm-500μm; The back pressure is 100kpa-800kpa. 8. A method for manufacturing a high-precision ceramic-based interdigital electrode with a three-layer structure as claimed in claim 1, wherein in the step (4), the pre-curing of the printed interdigital electrode is heat curing, One of UV curing, infrared curing and laser curing; Or, in the step (4), sintering is one of oven sintering, vacuum sintering and inert gas sintering; Or, in the step (4), flow inertness is introduced during the sintering process, and the sacrificial layer material and the organic solvent material in the conductive ink are discharged from the sintering furnace in time, the sintering temperature is 600°C-2200°C, and the sintering time is 10 minutes- 50 minutes; Or, in the step (4), the conductive core layer of the interdigitated electrode is selected from one of silver, copper, and modified liquid metal, and its thickness is 1 μm-50 μm. 9. A method for manufacturing a high-precision ceramic-based interdigital electrode with a three-layer structure as claimed in claim 1, wherein in the step (6), the anti-oxidation layer of the interdigital electrode is gold or platinum , the thickness of which is 300nm-2 microns; Or, in the step (6), the interdigital electrode reaction layer is Au, Ag or Pt, and its thickness is 300nm-2 microns; Or, in the step (6), the interdigitated electrode modification layer is a nanoporous metal layer, carbon nanotube or graphene, which is one of nanoporous gold, nanoporous silver and nanoporous copper, and its thickness is 50nm-300nm ; Or, in the step (6), the finger width of the interdigitated electrode is 0.1 micron-50 micron; the finger distance is 0.1 micron-50 micron; the electrode thickness is 1 micron-50 micron; the finger length is 1 mm-300 mm; Or, in the step (6), the fork index of the interdigitated electrodes is 2-200 pairs. 10. A high-precision ceramic-based interdigital electrode with a three-layer structure, characterized in that it is prepared by the method described in any one of claims 1-9.

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