Preparation method of resistance temperature coefficient adjustable nanometer cluster lattice

Abstract

The application provides a preparation method of a nano-cluster lattice with adjustable resistance temperature coefficient, which comprises the following steps: selecting a flexible substrate and a metal material, and the linear expansion coefficient of the flexible substrate is greater than that of the metal material; printing interdigital microelectrodes on the surface of the flexible substrate; using a cluster beam deposition system to deposit a metal nano-cluster lattice on the surface of the flexible substrate with the interdigital microelectrodes; matching the flexible substrate with the metal material to reduce the resistance temperature coefficient of the metal nano-cluster lattice; and on this basis, adjusting the resistance temperature coefficient of the metal nano-cluster lattice by controlling the coverage of the metal nano-cluster lattice, so as to realize the regulation of the resistance temperature coefficient. By changing the coverage of the nano-cluster lattice, the metal material and the flexible substrate, the effective regulation of the resistance temperature coefficient is realized, and the precision and stability of the intelligent sensing equipment are improved.

Description

Technical Field

[0001] This invention relates to the field of temperature coefficient control technology for nanocluster lattices, and specifically to a method for preparing nanocluster lattices with adjustable temperature coefficient of resistance. Background Technology

[0002] The temperature coefficient of resistance (TCR) is an important parameter for measuring the change of resistance of a material with temperature. It typically refers to the relative rate of change of resistance with temperature, and its magnitude and sign (positive or negative) directly affect the accuracy and stability of intelligent electronic devices. In many electronic devices, changes in the resistance of resistive elements can affect the performance of the entire circuit. To maintain the accuracy and stability of the circuit, it is necessary to control the characteristics of resistance changing with temperature, and the temperature coefficient of resistance can be controlled by changing the structure of the resistive material.

[0003] Nanoclusters typically refer to nanoscale aggregates composed of several to hundreds of atoms, whose electronic structure lies between that of atoms and molecules and macroscopic materials, exhibiting significant quantum size effects. Nanocluster films prepared by methods such as vapor deposition, magnetron sputtering, and electrochemical deposition have important application value in microelectronics, sensors, and other fields.

[0004] Current research on nanocluster thin films mainly focuses on the humidity sensing performance of sensors, without addressing the effective control of the temperature coefficient of resistance of nanocluster lattice. The resistance of ordinary metal thin films increases with temperature, making it impossible to control the temperature coefficient of resistance downwards. This limits their application in resistive elements requiring low temperature drift or zero temperature coefficient of resistance. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing a nanocluster lattice with adjustable temperature coefficient of resistance. Unlike traditional methods, this invention mainly regulates the temperature coefficient of resistance by changing the coverage of the metal nanocluster lattice, the material used in the metal nanocluster lattice, and the flexible substrate, thereby improving the accuracy and stability of intelligent sensing devices.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A method for preparing a nanocluster lattice with tunable temperature coefficient of resistance includes the following steps: A flexible substrate and a metal material for forming a metal nanocluster lattice are selected, wherein the coefficient of linear expansion of the flexible substrate is greater than the coefficient of linear expansion of the metal material; Interdigitated microelectrodes are printed on the surface of the flexible substrate; A cluster beam deposition system is used to deposit a metal nanocluster lattice on the surface of a flexible substrate printed with the interdigitated microelectrodes. By matching the flexible substrate with the metal material, the temperature coefficient of resistance of the metal nanocluster lattice is reduced; based on this, the temperature coefficient of resistance is fine-tuned by controlling the coverage of the metal nanocluster lattice, thereby realizing the regulation of the temperature coefficient of resistance of the metal nanocluster lattice.

[0007] This invention selects the metal material used to form the metal nanocluster lattice and the flexible substrate, and simultaneously controls the coverage of the nanocluster lattice to reduce the temperature coefficient of resistance of the nanocluster lattice, which is continuously adjustable within a certain range.

[0008] The principle of resistance temperature coefficient control in this invention is as follows: (1) The resistance of metal nanocluster lattice films decreases with increasing temperature, while the resistance of ordinary metal films increases with increasing temperature.

[0009] (2) On the surface of the flexible substrate, the resistance of both the metal nanocluster lattice film and the ordinary metal film increases with temperature due to the thermal expansion of the substrate, and the rate of change of the metal nanocluster lattice film is one order of magnitude larger than that of the metal film. The reason why the resistance of the metal nanocluster lattice film on the surface of the flexible substrate increases with temperature due to the thermal expansion of the substrate is that the resistance of the metal nanocluster lattice film increases with the increase of the inter-cluster inter-plane spacing. At the same time, the linear expansion coefficient of the metal is smaller than that of the flexible substrate. Therefore, the net increase in the inter-plane spacing caused by thermal expansion leads to the net increase in the resistance of the nanocluster lattice film.

[0010] (3) Combining the above two factors, the temperature coefficient of resistance of the cluster film on the surface of the flexible substrate can be controlled downward (reduced) (the intrinsic temperature coefficient of the metal nanocluster lattice film is controlled by the material used in the metal nanocluster lattice and the coverage of the metal nanocluster lattice, and the change in resistance caused by thermal expansion is controlled by the difference in the coefficient of linear expansion between the material used in the metal nanocluster lattice and the flexible substrate). With appropriate matching, it can even reach zero temperature coefficient. However, for ordinary metal films, the above two effects simultaneously cause the resistance to increase with the increase of temperature, making it impossible to control the temperature coefficient of resistance downward (reduced).

[0011] Preferably, the metal material used to form the metal nanocluster lattice is provided in the form of a metal target material having a low coefficient of linear expansion. The metal target material is at least one of molybdenum, tungsten, tantalum, zirconium, platinum, rhodium, and palladium, or an alloy formed from at least two of molybdenum, tungsten, tantalum, zirconium, platinum, rhodium, and palladium.

[0012] Preferably, the flexible substrate is a polymer material with a high coefficient of linear expansion, and the flexible substrate is one of silicone plastic (SI), polydimethylsiloxane (PDMS), polyethylene (PE), polypropylene (PP), polytetrafluoroethylene (PTFE), and polyethylene terephthalate (PET) film.

[0013] Preferably, the ratio of the linear expansion coefficient of the flexible substrate material to that of the metallic material is ≥5.

[0014] Preferably, the coverage of the nanocluster lattice is 30-85%.

[0015] Preferably, the step of controlling the temperature coefficient of resistance of the metal nanocluster lattice includes: selecting a flexible substrate and a metal material for forming the metal nanocluster lattice; depositing metal nanocluster lattices with different coverage rates on the surface of the flexible substrate printed with interdigitated electrodes; measuring the temperature coefficient of resistance of the metal nanocluster lattice to obtain a curve of the temperature coefficient of resistance changing with the coverage rate of the cluster lattice; and controlling the deposition amount of the metal nanocluster lattice according to the curve to finely adjust the temperature coefficient of resistance of the cluster lattice.

[0016] Preferably, a cluster beam deposition system is used to deposit a metal nanocluster lattice on the surface of a flexible substrate printed with the interdigitated microelectrodes, specifically including the following steps: A flexible substrate printed with interdigitated microelectrodes is placed in the deposition chamber of a magnetron plasma gas cluster beam deposition system; an inert gas is introduced as a sputtering gas and a buffer gas to perform DC magnetron sputtering on the target material, and the generated plasma nucleates and grows in the buffer gas to form nanoparticles. The nanoparticles are ejected from the nozzle under the action of buffer gas flow, enter the deposition chamber through the differential system, form a nanoparticle beam, and are deposited on the surface of a flexible substrate with interdigitated microelectrodes printed on it, forming a metal nanocluster lattice.

[0017] Preferably, the process parameters of the magnetron plasma gas agglomeration cluster beam deposition system are as follows: the condensation distance between the target and the nozzle is 50~200mm, and the nozzle diameter is 3~10mm; the inert gas introduced is high-purity argon or nitrogen, and the gas pressure is controlled at 50~200Pa; the magnetron sputtering power density is 0.005~0.030W / mm². 2 Within the range; the deposition time is within the range of 200~1000s.

[0018] Preferably, the process for printing interdigitated microelectrodes on the surface of a flexible substrate is vapor deposition, screen printing, inkjet printing, or 3D printing.

[0019] Preferably, the method further includes a step of measuring the temperature coefficient of resistance of the deposited metal nanocluster lattice.

[0020] The beneficial effects of this invention are: This invention employs cluster beam deposition technology to controllably deposit metal nanocluster lattices on flexible substrates. By changing the materials used for the metal nanocluster lattice, adjusting the cluster deposition conditions, and varying the material of the flexible substrate, the temperature coefficient of resistance of the metal nanocluster lattice can be effectively controlled. By selecting appropriate materials for the metal nanocluster lattice, flexible substrate materials, and suitable process parameters, it is expected that the temperature coefficient of resistance can approach zero, thereby improving the accuracy and stability of resistive elements.

[0021] This invention is based on the synergistic control mechanism of metal nanocluster lattice thin films on flexible substrates, which enables the downward control of the temperature coefficient of resistance and even the zero temperature coefficient, which is impossible for ordinary metal thin films. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 The resistance-temperature curve of the palladium nanocluster lattice in Example 1; Figure 2 The resistance-temperature curves of the palladium nanocluster lattice in Example 2 are shown. Figure 3 The resistance-temperature curve of the palladium nanocluster lattice in Example 3; Figure 4 The resistance-temperature curve of the molybdenum nanocluster lattice in Example 4; Figure 5 The image shows the resistance-temperature curve of the molybdenum nanocluster lattice in Example 5. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] Example 1: Silver interdigitated electrodes were printed on the surface of a 50 μm thick flexible PET substrate using vapor deposition. The PET flexible substrate with the printed interdigitated microelectrodes was then placed in the deposition chamber of a magnetron plasma gas agglomeration cluster beam deposition system. The deposition time was maintained at 2 × 10⁻⁶. -4 A dynamic vacuum of 80 Pa was maintained, with a condensation distance of 150 mm between the target and the nozzle, and a nozzle diameter of 6 mm. High-purity argon gas was introduced as both the sputtering gas and the buffer gas to maintain a stable pressure of 80 Pa. DC magnetron sputtering was then performed on the palladium target, controlling the sputtering power density at 0.015 W / mm². 2 The high-concentration plasma sputtered out nucleates and grows in a buffer gas, and is ejected from the nozzle under the action of the buffer gas flow, enters the deposition chamber through a differential system, and is deposited on the surface of a flexible PET substrate printed with silver interdigitated electrodes. The deposition time is controlled at 600s to obtain a palladium nanocluster lattice with a coverage of approximately 55%.

[0026] Enameled wires (approximately 50 μm in diameter) were connected to the interdigitated electrode leads of the palladium nanoclusters using conductive silver paste, and then covered with a PET film to protect the metal nanoclusters from external damage. The palladium nanoclusters were placed in a constant temperature and humidity chamber, and the resistance temperature was measured at different temperatures ranging from -20°C to 60°C using a digital source meter, and the results were plotted as curves.

[0027] Figure 1 The resistance temperature curve of the palladium nanocluster lattice prepared in this embodiment is shown. Based on the curve data, the resistance temperature coefficient at 20℃ can be calculated using the formula for calculating the resistance temperature coefficient, which is -4254ppm / ℃.

[0028] Example 2: The difference from Example 1 is that the sputtering power density is 0.015 W / mm. 2 The deposition time of the nanoparticles was 300s, resulting in a palladium nanocluster lattice with a coverage of approximately 30%.

[0029] Enameled wires (approximately 50 μm in diameter) were connected to the interdigitated electrode leads of the palladium nanoclusters using conductive silver paste, and then covered with a PET film to protect the palladium nanoclusters from external damage. The palladium nanoclusters were placed in a constant temperature and humidity chamber, and the resistance temperature was measured at different temperatures ranging from -20°C to 60°C using a digital source meter, and the results were plotted as curves.

[0030] Figure 2 The resistance temperature curve of the palladium nanocluster lattice prepared in this embodiment is shown. Based on the curve data, the resistance temperature coefficient can be calculated as -6474ppm / ℃ using the formula for calculating the resistance temperature coefficient with 20℃ as the reference temperature.

[0031] Example 3: The difference from Example 1 is that the flexible substrate is a PDMS flexible substrate with a thickness of 100 μm, thereby obtaining a PDMS-based palladium nanocluster lattice.

[0032] Enameled wires (approximately 50 μm in diameter) were connected to the interdigitated electrode leads of the palladium nanoclusters using conductive silver paste, and then covered with a PDMS film to protect the palladium nanoclusters from external damage. The palladium nanoclusters were placed in a constant temperature and humidity chamber, and the resistance-temperature ratio at different temperatures ranging from -20°C to 60°C was measured using a digital source meter and plotted as a curve.

[0033] Figure 3 The resistance temperature curve of the PDMS-based palladium nanoclusters prepared in this embodiment is shown. Based on the curve data, the resistance temperature coefficient at a reference temperature of 20℃ can be calculated as -1058ppm / ℃ using the formula for calculating the resistance temperature coefficient.

[0034] Example 4: The difference from Example 1 is that the DC magnetron sputtering target is molybdenum, thereby obtaining a molybdenum nanocluster lattice.

[0035] Enameled wires (approximately 50 μm in diameter) were connected to the interdigitated electrode leads of the molybdenum nanoclusters using conductive silver paste, and then covered with a PET film to protect the nanoclusters from external damage. The molybdenum nanoclusters were placed in a constant temperature and humidity chamber, and the resistance temperature was measured at different temperatures ranging from -20°C to 60°C using a digital source meter, and the results were plotted as curves.

[0036] Figure 4 The resistance temperature curve of the molybdenum nanocluster lattice prepared in this embodiment is shown. Based on the curve data, the resistance temperature coefficient at a reference temperature of 20℃ can be calculated as 535ppm / ℃ using the formula for calculating the resistance temperature coefficient.

[0037] Example 5: Silver interdigitated electrodes were printed on the surface of a 100 μm thick PDMS flexible substrate using vapor deposition. The PDMS flexible substrate with the printed interdigitated microelectrodes was then placed in the deposition chamber of a magnetron plasma gas agglomeration cluster beam deposition system. The deposition time was maintained at 2 × 10⁻⁶. -4 A dynamic vacuum of 95 Pa was maintained, with a condensation distance of 75 mm between the target and the nozzle, and a nozzle diameter of 8 mm. High-purity argon gas was introduced as both the sputtering gas and the buffer gas to maintain a stable pressure of 95 Pa. DC magnetron sputtering was then performed on the molybdenum target, with the sputtering power density controlled at 0.025 W / mm². 2The high-concentration plasma sputtered out nucleates and grows in a buffer gas, and under the action of the buffer gas flow, it is ejected from the nozzle and enters the deposition chamber through a differential system, depositing on the surface of a PDMS flexible substrate printed with silver interdigitated electrodes. By controlling the deposition time to 900 s, a molybdenum nanocluster lattice with a coverage of approximately 85% is obtained.

[0038] Enameled wires (approximately 50 μm in diameter) were connected to the interdigitated electrode pins of the molybdenum nanoclusters using conductive silver paste, and then covered with a PDMS film to protect the molybdenum nanoclusters from external damage. The molybdenum nanoclusters were placed in a constant temperature and humidity chamber, and the resistance-temperature ratio at different temperatures ranging from -20°C to 60°C was measured using a digital source meter and plotted as a curve.

[0039] Figure 5 The resistance temperature curve of the PDMS-based molybdenum nanoclusters lattice prepared in this embodiment is shown. Based on the curve data, the resistance temperature coefficient can be calculated using the formula for the resistance temperature coefficient with 20℃ as the reference temperature as approximately 2ppm / ℃.

[0040] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a nanocluster lattice with tunable temperature coefficient of resistance, characterized in that, Includes the following steps: A flexible substrate and a metal material for forming a metal nanocluster lattice are selected, wherein the coefficient of linear expansion of the flexible substrate is greater than the coefficient of linear expansion of the metal material; Interdigitated microelectrodes are printed on the surface of the flexible substrate; A cluster beam deposition system is used to deposit a metal nanocluster lattice on the surface of a flexible substrate printed with the interdigitated microelectrodes. By matching the flexible substrate with the metal material, the temperature coefficient of resistance of the metal nanocluster lattice is reduced; based on this, the temperature coefficient of resistance is fine-tuned by controlling the coverage of the metal nanocluster lattice, thereby realizing the regulation of the temperature coefficient of resistance of the metal nanocluster lattice.

2. The method for preparing a temperature-coefficient-adjustable nanocluster lattice as described in claim 1, characterized in that, The metal material used to form the metal nanocluster lattice is provided in the form of a metal target material having a low coefficient of linear expansion. The metal target material is at least one of molybdenum, tungsten, tantalum, zirconium, platinum, rhodium, and palladium, or an alloy formed from at least two of molybdenum, tungsten, tantalum, zirconium, platinum, rhodium, and palladium.

3. The method for preparing a temperature-coefficient-adjustable nanocluster lattice as described in claim 1, characterized in that, The flexible substrate is a polymer material with a high coefficient of linear expansion, and the flexible substrate is one of the following: silicone plastic, polydimethylsiloxane, polyethylene, polypropylene, polytetrafluoroethylene, and polyethylene terephthalate film.

4. The method for preparing a temperature coefficient-tunable nanocluster lattice as described in claim 1, characterized in that, The ratio of the linear expansion coefficient of the flexible substrate material to that of the metallic material is ≥5.

5. The method for preparing a temperature-coefficient-adjustable nanocluster lattice as described in claim 1, characterized in that, The coverage of the nanocluster lattice is 30-85%.

6. The method for preparing a temperature-coefficient-adjustable nanocluster lattice as described in claim 1, characterized in that, A cluster beam deposition system is used to deposit a metal nanocluster lattice on the surface of a flexible substrate printed with the interdigitated microelectrodes, specifically including the following steps: A flexible substrate printed with interdigitated microelectrodes is placed in the deposition chamber of a magnetron plasma gas cluster beam deposition system; an inert gas is introduced as a sputtering gas and a buffer gas to perform DC magnetron sputtering on the target material, and the generated plasma nucleates and grows in the buffer gas to form nanoparticles. The nanoparticles are ejected from the nozzle under the action of buffer gas flow, enter the deposition chamber through the differential system, form a nanoparticle beam, and are deposited on the surface of a flexible substrate with interdigitated microelectrodes printed on it, forming a metal nanocluster lattice.

7. The method for preparing a temperature coefficient-tunable nanocluster lattice as described in claim 6, characterized in that, The process parameters of the magnetron plasma gas agglomeration cluster beam deposition system are as follows: the condensation distance between the target and the nozzle is 50~200mm, and the nozzle diameter is 3~10mm; the inert gas introduced is high-purity argon or nitrogen, and the gas pressure is controlled at 50~200Pa; the magnetron sputtering power density is 0.005~0.030W / mm². 2 Within the range; the deposition time is within the range of 200~1000s.

8. The method for preparing a temperature coefficient-tunable nanocluster lattice of resistance as described in any one of claims 1 to 7, characterized in that, The process of printing interdigitated microelectrodes on the surface of flexible substrates can be vapor deposition, screen printing, inkjet printing, or 3D printing.

9. The method for preparing a temperature coefficient-tunable nanocluster lattice of resistance as described in any one of claims 1 to 7, characterized in that, It also includes the step of measuring the temperature coefficient of resistance of the deposited metal nanoclusters lattice.

Images