A method for manufacturing a high-temperature-resistant thin film temperature sensor based on laser manufacturing

Abstract

The application discloses a high-temperature-resistant film temperature sensor preparation method based on laser manufacturing. First, a precursor film of a polymer precursor ceramic is coated on a substrate. After being heated to 180 DEG C or being naturally placed to solidify, the precursor film is scanned by a fiber laser in a certain mode, and the unnecessary part is removed, and the pattern part is left, so that the polymer precursor ceramic sensing film is simultaneously completed by patterning and pyrolysis. By using the technical scheme, the problems of a wide pattern, low preparation efficiency and high cost of the polymer precursor ceramic film are solved.

Description

Technical Field

[0001] This invention belongs to the field of thin-film sensor technology, and particularly relates to a method for preparing a high-temperature resistant thin-film temperature sensor based on laser manufacturing. Background Technology

[0002] With the increasing demand for high-temperature measurement, research on polymer precursor ceramic thin-film sensors is growing. The main challenges in fabricating high-temperature PDC thin-film sensors include low fabrication efficiency and difficulty in fine patterning. A solution is to utilize laser-assisted localized pyrolysis of the polymer precursor, rapidly converting it into ceramic. This method significantly improves fabrication efficiency because laser pyrolysis is fast and allows for precise control of the pyrolysis region, reducing unnecessary material waste.

[0003] However, traditional laser manufacturing requires patterning followed by pyrolysis. A new method has emerged that uses high-precision femtosecond lasers to directly pattern polymer precursor films, achieving fine patterns with a minimum linewidth of 30 micrometers. This method offers high resolution and precision, but the equipment is expensive, and further pyrolysis is required. Alternatively, rapid thermal processing of polymer precursors can achieve ceramization in a short time, completing a process that traditionally takes hours in seconds to minutes, significantly improving efficiency. However, this method demands sophisticated equipment, requiring an inert atmosphere and currents of tens of amperes. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method for preparing a high-temperature resistant thin film temperature sensor based on laser manufacturing, which solves the problems of wide patterns, low preparation efficiency and high cost of polymer precursor ceramic thin films.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A method for fabricating a high-temperature resistant thin-film temperature sensor based on laser manufacturing, comprising:

[0007] Step S1: Add 10-20% by mass of titanium diboride nanoparticles, 10-20% by mass of zirconium diboride nanoparticles, and 10-20% by mass of silicon carbide nanoparticles to a liquid precursor such as polysilazane, polysiloxane, or polycarbosilane. Add 60-80% by mass of titanium diboride nanoparticles to the liquid precursor such as polysilazane, polysiloxane, or polycarbosilane. After magnetic stirring for 1-2 hours, obtain the precursor slurry for PDC sensing film and solder joints, respectively.

[0008] Step S2: After ultrasonic cleaning and drying of the alumina substrate, a sensitive layer precursor film is printed on the treated alumina substrate using flexible screen printing.

[0009] Step S3: Use a fiber laser to scan the PDC sensing film precursor along a certain path, remove the unwanted parts, and leave the patterned parts, which are the pyrolysis and patterned PDC sensing films.

[0010] Step S4: Apply the PDC solder joint precursor liquid to the pins of the PDC sensing film, place the PDC lead connector and press it with a pressure block, then place it in a tube furnace and heat it to 800-1000°C in a low vacuum atmosphere for 1-4 hours to obtain the PDC thin film temperature sensor. Preferably, the titanium diboride powder has a particle size of 40 nanometers.

[0011] Preferably, the particle size of titanium diboride, zirconium diboride, silicon carbide, and other powders is 10–90 nanometers.

[0012] Preferably, the precursor liquids of the polymer precursor ceramics SiCN, SiCO, and SiC are polysilazane PSN, polysiloxane PSO, and polycarbosilane PCS, respectively; the alumina substrate is a planar alumina substrate or a curved alumina substrate.

[0013] Preferably, the fiber laser has a spot diameter of 20–150 micrometers, a scanning speed of 20–1000 mm / s, a power of 3–30 W, a wavelength of 1.064 μm, a frequency of 20 kHz, and a scanning path that gradually moves away from the target line in an S-shape; the linewidth of the PDC sensing film obtained by scanning is 10–2000 micrometers.

[0014] Preferably, the compressed block is an alumina block, and the heat treatment atmosphere is a low-degree vacuum, with a vacuum degree of 1 Pa to 700 Pa.

[0015] This invention employs a laser removal method to rapidly obtain polymer precursor ceramic sensing films with fine linewidths. A specific scanning path is used to remove excess film while simultaneously pyrolyzing the remaining portions, achieving simultaneous patterning and pyrolysis. Furthermore, it can obtain PDC sensing films with linewidths as fine as 10 micrometers. Based on this, a thin-film temperature sensor was fabricated, and resistance-temperature testing was conducted from room temperature to 1000°C, along with stability testing. The thin-film sensor prepared by this method can withstand temperatures up to 900°C and exhibits good repeatability and stability. Attached Figure Description

[0016] 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 embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0017] Figure 1 This is a flowchart illustrating the fabrication process of a high-temperature resistant thin-film temperature sensor based on laser manufacturing, as described in an embodiment of the present invention.

[0018] Figure 2 Optical micrograph of the prepared PDC sensing thin film with a linewidth of approximately 10 micrometers;

[0019] Figure 3 Optical images of PDC sensing films with different designed linewidths prepared by laser removal method; among them, Figure 3 (a)-(f) are optical images of the actual thin films designed at 50μm, 100μm, 200μm, 300μm, 400μm and 500μm respectively. The black lines represent PDC sensing thin films.

[0020] Figure 4 The relationship between the actual linewidth and the designed linewidth of the PDC sensing film prepared by laser removal method;

[0021] Figure 5 A schematic diagram illustrating the principle of laser removal of PDC thin films to achieve patterning and pyrolysis, wherein... Figure 5 (a)-(d) represent the removal effects when the power is insufficient, the power is slightly high, the power is appropriate, and the power is too high, respectively.

[0022] Figure 6 Optical micrographs of various fine-linewidth PDC thin films prepared by laser removal methods; among them, Figure 6 (a) Optical images of heat flow meter patterns with different linewidths. Figure 6 (b)~6(d) are Figure 6 (a) Optical micrographs of heat flow meter patterns with different linewidths. Figure 6 (e) Optical images of grating patterns with different line widths. Figure 6 (f)~6(h) are Figure 6 Optical micrographs of grating patterns with different linewidths in (e). Figure 6 (i) is an optical image of the grating pattern on an alumina sphere. Figure 6 (j) is Figure 6 (i) Optical micrograph of the grid pattern. Figure 6 (k) is an optical image of the heat flow meter pattern on the alumina sphere. Figure 6 (l) is Figure 6 Optical micrograph of the heat flow meter pattern in (k). Figure 6 (m) is an optical image of the pentagram pattern on an alumina sphere. Figure 6 (n) and Figure 6 (o) is Figure 6 Optical micrograph of the pentagram pattern in (m);

[0023] Figure 7 (a) An optical image of a thin-film temperature sensor prepared using the method described in this patent. Figure 7 (b) is a microscopic optical image of the sensing thin film of the prepared thin-film temperature sensor. Figure 7 (c) shows the test curves of the thin-film temperature sensor from room temperature to 900°C for 6 rounds. Figure 7 (d) shows the 6-round temperature resistance curves of the thin-film sensor. Figure 7 (e) shows the changes in resistance and temperature of the thin-film sensor over time. Figure 7 (f) shows the test curve of the thin-film sensor after being kept at 900℃ for 2 hours. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and 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] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] Example 1:

[0027] like Figure 1 As shown, this embodiment of the invention provides a method for fabricating a high-temperature resistant thin-film temperature sensor based on laser manufacturing, comprising:

[0028] Step S1: Add 20% by mass of titanium diboride nanoparticles, 20% by mass of zirconium diboride nanoparticles and 10% by mass of silicon carbide nanoparticles to the polysilazane PSN liquid precursor, and add 70% by mass of titanium diboride nanoparticles to the polysilazane PSN liquid precursor. After magnetic stirring for 1 hour, the precursor slurry of PDC sensing film and solder joint are obtained respectively.

[0029] Step S2: After ultrasonic cleaning and drying of the alumina substrate, a sensitive layer precursor film is printed on the treated alumina substrate using flexible screen printing; wherein, the dimensions of the alumina substrate are: 15mm×15mm×1mm.

[0030] Step S3: Use a fiber laser to scan the PDC sensing film precursor, remove the unwanted parts, and leave the patterned part, which is the patterned and pyrolyzed sensing film; wherein, the parameters of the fiber laser are: scanning speed 160mm / s, power 18W, wavelength 1.064μm, frequency 20kHz, and spot diameter 50μm.

[0031] Step S4: Apply PDC solder joint precursor liquid to the pins of the PDC sensing film, place the PDC lead connector and press it, then place it in a tube furnace and heat it to 1000℃ in a 60Pa vacuum atmosphere for 1 hour to obtain the PDC thin film temperature sensor.

[0032] Figure 2 The PDC sensing film with a linewidth of approximately 10 micrometers was obtained by laser scanning. The laser parameters were: scanning speed 160 mm / s, power 18 W, wavelength 1.064 μm, frequency 20 kHz, spot diameter 50 μm, and gap 10 micrometers without removal.

[0033] Typically, the designed width of a thin film is positively correlated with its actual linewidth. Figure 3 PDC sensing films with different linewidths were prepared by laser removal method. It can be seen that the actual linewidth of the prepared film also increases with the increase of the designed linewidth. The designed linewidths were 50 μm, 100 μm, 200 μm, 300 μm, 400 μm, and 500 μm, while the actual obtained linewidths were 61.9 μm, 123.7 μm, 221.6 μm, 314.4 μm, 412.4 μm, and 567.0 μm, respectively. Figure 4 The relationship between the actual linewidth and the designed linewidth of the PDC sensing film prepared by the laser removal method is shown. It can be seen that the actual linewidth and the designed linewidth are almost linearly related, which provides a process reference for preparing sensing films with different linewidths.

[0034] Based on the above parameter studies, we can summarize the principle of laser removal for patterning PDC thin films, such as... Figure 5 The diagram illustrates the principle of laser removal of PDC thin films to achieve patterning and pyrolysis. At a certain scanning speed, when the laser power is below a certain value, the laser acts on the PDC precursor film. The energy received by the PDC precursor film is insufficient to vaporize it. However, because the laser acts on the PDC precursor film, the temperature exceeds the pyrolysis temperature, and the film near the laser scan is pyrolyzed into a PDC sensing film, such as... Figure 5 As shown in Figure a. When the laser power exceeds a certain value, the surface of the PDC precursor film begins to vaporize. The PDC precursor film near the laser scan is pyrolyzed into a PDC sensing film. After vaporization, the PDC precursor film condenses into PDC residue in the nearby air. Figure 5 As shown in b, with the increase of laser power, the surface and interior are completely vaporized, and the thin film at a certain distance on both sides of the laser scanning path is pyrolyzed into a PDC sensing film, such as... Figure 5 As shown in c. When the power is high enough, the PDC precursor film scanned by the laser is completely vaporized, and even a portion of the substrate is vaporized, such as... Figure 5As shown in d. Therefore, according to the set scanning path, the speed and power are adjusted, the laser scanning point is the area to be removed, the area near the laser scanning point is the pyrolysis area, and the remaining PDC sensing film is the desired patterned and pyrolyzed sensing film.

[0035] Based on the above mechanism and parameter optimization, PDC sensing film patterns with different linewidths and shapes were prepared, such as... Figure 6 As shown. The laser parameters used are: scanning speed 160mm / s, power 18W, and frequency 20kHz. (From...) Figure 2 As can be seen, this method can produce PDC sensing films with a linewidth of approximately 10 micrometers, which is smaller than that produced using femtosecond lasers. Furthermore, the method described in this invention can be used to fabricate various patterns and sensing films on curved surfaces, such as… Figure 6 The image i-6o shows a PDC sensing pattern fabricated on a sphere.

[0036] A thin-film temperature sensor was prepared using the method described in this embodiment of the invention. The prepared sample is shown below. Figure 7 As shown in a, Figure 7 b is a micrograph of the PDC sensing film. Temperature resistance was measured on this sample. Figure 7 c represents the test curves of the prepared thin-film temperature sensor from room temperature to 900℃ over six rounds. Figure 7 d represents the six-round temperature resistance curves of the thin-film sensor, showing good repeatability. Figure 7 e represents the change in resistance and temperature of the thin-film sensor over time. It can be seen that the resistance stability is good at each temperature point. Figure 7 f represents the test curve of the thin-film sensor after being kept at 900℃ for 2 hours. The resistance change rate after 2 hours is only -2.4%, indicating good resistance stability. Therefore, the thin-film sensor prepared by the method of this embodiment has good stability and repeatability, and can withstand temperatures up to 900℃. The thin-film sensor prepared by the method of this embodiment and thin-film sensors prepared by other methods have similar stability and repeatability.

[0037] This invention employs a low-cost fiber laser for simultaneous pattern removal and pyrolysis, achieving fine patterning of PDC sensing films. The relationship between the actual and designed linewidths of the PDC was investigated. The laser-induced pattern removal mechanism of the PDC sensing film was revealed. Fine fabrication of PDC films on planar / curved substrates was achieved, with a minimum linewidth of 10 micrometers, and the equipment cost was low. A PDC thin-film sensor was fabricated and tested, verifying that the method of this invention can be used to fabricate thin-film sensors with fine linewidths.

[0038] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for fabricating a high-temperature resistant thin-film temperature sensor based on laser manufacturing, characterized in that, include: Step S1: Add 10-20% by mass of titanium diboride nanoparticles, 10-20% by mass of zirconium diboride nanoparticles, and 10-20% by mass of silicon carbide nanoparticles to a polysilazane, polysiloxane, or polycarbosilane liquid precursor. Add 60-80% by mass of titanium diboride nanoparticles to the polysilazane, polysiloxane, or polycarbosilane liquid precursor. After magnetic stirring for 1-2 hours, obtain the precursor slurry for the PDC sensing film and the solder joint, respectively. Step S2: After ultrasonic cleaning and drying of the alumina substrate, a sensitive layer precursor film is printed on the treated alumina substrate using flexible screen printing. Step S3: Use a fiber laser to scan the PDC sensing film precursor along a certain path to remove the unwanted parts, leaving the patterned parts, which are the pyrolysis and patterned PDC sensing film. Step S4: Apply PDC solder joint precursor liquid to the pins of PDC sensing film, place PDC lead connectors and press them with pressure blocks, then place them in a tube furnace and heat them to 800~1000℃ in a vacuum atmosphere for 1~4 hours to obtain a PDC thin film temperature sensor. The particle size of titanium diboride, zirconium diboride, and silicon carbide powders is 10~90 nanometers; The precursor liquids of polymer precursor ceramics SiCN, SiCO, and SiC are polysilazane PSN, polysiloxane PSO, and polycarbosilane PCS, respectively; the alumina substrate is a planar alumina substrate or a curved alumina substrate. The fiber laser has a spot diameter of 20-150 micrometers, a scanning speed of 20-1000 mm / s, a power of 3-30 W, a wavelength of 1.064 μm, a frequency of 20 kHz, and a scanning path that gradually moves away from the target line in an S-shape; the linewidth of the PDC sensing film obtained by scanning is 10-2000 micrometers. The compressed blocks are made of alumina, and the heat treatment atmosphere is a low-degree vacuum, with a vacuum degree of 1Pa~700Pa.

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