Preparation process of high-temperature-resistant ceramic fiber composite electronic base cloth
By constructing a multi-layered gradient interface phase and functional layer on the surface of ceramic fibers and combining it with a three-dimensional weaving process, the problems of functional limitation, thermal mismatch, and insufficient electromagnetic compatibility of flexible electronic substrates under extreme high-temperature environments have been solved, thus realizing the reliability and functional integration of electronic substrates under high temperatures.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HEZE JIAZE ELECTRONIC MATERIALS CO LTD
- Filing Date
- 2026-03-09
- Publication Date
- 2026-06-05
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Abstract
Description
Technical Field
[0001] This invention relates to the field of electronic substrate technology, and in particular to a preparation process for a high-temperature resistant ceramic fiber composite electronic substrate. Background Technology
[0002] With the rapid development of cutting-edge technologies such as aerospace, nuclear energy, and hypersonic vehicles, the demand for flexible electronic devices that can operate stably in extreme high-temperature environments is becoming increasingly urgent. Traditional polymer flexible circuit boards are limited by their glass transition temperature and thermal decomposition temperature, making it difficult to meet the requirements for use above 300°C.
[0003] Ceramic fiber materials have become a research focus for high-temperature flexible circuit boards due to their excellent high-temperature stability, electrical insulation, and mechanical properties. In existing technologies, researchers have proposed various technical solutions. For example, some studies have reported on surface-strengthened ceramic fiber flexible thermal insulation structures, employing high-temperature alloy foil, high-temperature alloy braided mesh, and ceramic fiber laminated structures, exhibiting good high-temperature resistance and thermal insulation performance. Other studies have explored methods for preparing fiber-reinforced polymer-ceramic composite materials using wet electrospinning.
[0004] In the study of interfacial phases in ceramic matrix composites, research has shown that forming ultra-high temperature ceramic interfacial phases on fiber surfaces can achieve uniform and controllable interfacial layer thickness. Other studies have systematically explored the influence of interfacial phase deposition process parameters on microstructure and uniformity. Research indicates that interfacial phase thickness plays a crucial role in the mechanical properties of composite materials; an appropriately thick interfacial phase can significantly increase flexural strength.
[0005] However, existing technologies still have the following technical problems: First, they are functionally limited, with most solutions focusing only on the heat resistance or structural performance of the substrate and failing to integrate circuit functions with the substrate design; second, there are interface problems, as the thermal mismatch between fibers and the matrix and the interfacial bonding strength are difficult to control precisely, affecting the reliability and lifespan of composite materials; third, there is a lack of intelligence, as the substrate cannot sense its own thermal damage state and cannot achieve early failure warning; and fourth, there is insufficient electromagnetic compatibility, as existing substrates lack the adjustability of electromagnetic shielding or wave transmission in high-frequency and high-temperature environments.
[0006] Therefore, this invention proposes a preparation process for high-temperature resistant ceramic fiber composite electronic substrate. Summary of the Invention
[0007] The purpose of this invention is to address the shortcomings of existing technologies by proposing a preparation process for high-temperature resistant ceramic fiber composite electronic substrate.
[0008] To achieve the above objectives, the present invention adopts the following technical solution:
[0009] This invention proposes a preparation process for a high-temperature resistant ceramic fiber composite electronic substrate, comprising the following steps:
[0010] Step (1): An inner interface layer, a gradient transition layer, and an outer functional layer are sequentially deposited on the surface of continuous ceramic fibers using chemical vapor deposition to form a multilayer gradient interface phase. The inner interface layer is a pyrolytic carbon layer or a boron nitride layer with a thickness of 50–200 nm. The gradient transition layer consists of 3–7 alternating layers of SiC and BN, each with a thickness of 100–500 nm. The outer functional layer is a SiC layer doped with carbon nanotubes or a BN layer doped with BaTiO3 with a thickness of 200–400 nm.
[0011] Step (2): The fibers processed in step (1) are woven into a bottom layer fabric using a three-dimensional weaving process. At the same time, ceramic fibers doped with functional nanophases are mixed with ordinary ceramic fibers according to a preset pattern to form a top layer functional fabric with circuit printing area, thermal damage sensing area and electromagnetic control area. Then, the bottom layer fabric and the top layer functional fabric are stacked and fixed to obtain a fabric preform.
[0012] Step (3): The fabric preform obtained in step (2) is densified by using a precursor impregnation pyrolysis process or a chemical vapor infiltration process to obtain a ceramic matrix composite material;
[0013] Step (4): Plasma treatment is performed on the top surface of the ceramic matrix composite material obtained in step (3), and then high-temperature resistant conductive paste is printed on the top surface according to the design pattern using inkjet printing or screen printing technology, and conductive circuits are formed by high-temperature sintering.
[0014] Step (5): Connect high-temperature resistant leads to the electrode positions in the heat damage sensing area and coat the entire surface with a protective coating.
[0015] Preferably, the deposition conditions of the gradient transition layer in step (1) are as follows: the BN layer adopts the BCl3-NH3-H2 system, with a BCl3 flow rate of 20–50 sccm, an NH3 flow rate of 50–100 sccm, an H2 flow rate of 100–300 sccm, a deposition temperature of 700–1000℃, and a deposition pressure of 1–5 kPa; the SiC layer adopts the trichloromethylsilane-H2 system, with a trichloromethylsilane flow rate of 10–30 sccm, an H2 flow rate of 100–500 sccm, a deposition temperature of 900–1100℃, and a deposition pressure of 1–5 kPa; the deposition rate is controlled at 5–20 nm / min.
[0016] Preferably, the outer functional layer in step (1) is a SiC layer doped with carbon nanotubes, and its deposition conditions are as follows: carbon nanotubes are dispersed in ethanol, ultrasonically dispersed for 30–60 min, and introduced into the reaction chamber together with trichloromethylsilane, with the carbon nanotube content being 1–5 wt% of the mass of SiC; or the outer functional layer is a BN layer doped with BaTiO3, and its deposition conditions are as follows: Ba(TiO(C4H9))3 and BCl3-NH3-H2 system are co-deposited, and the molar ratio of Ba:Ti:B:N is controlled between 1:1:10:10 and 1:1:20:20.
[0017] Preferably, the ceramic fibers doped with functional nanophases in step (2) include aluminum-zinc oxide piezoelectric sensing fibers and carbon-SiBCN electromagnetic control fibers; the molar ratio of Al to Zn in the aluminum-zinc oxide piezoelectric sensing fibers is 2–5:100; and the mass fraction of carbon nanotubes or graphene in the carbon-SiBCN electromagnetic control fibers is 5–15%.
[0018] Preferably, the three-dimensional weaving process in step (2) is 2.5D weaving or three-dimensional interlocking weaving; the fiber volume fraction of the bottom fabric is 35-50%, and the fiber volume fraction of the top functional layer fabric is 25-40%; an interface layer fiber web with a thickness of 50-100μm is also laid between the bottom fabric and the top functional layer fabric, and the interface layer fiber web is made by wet web forming process from the short chopped fibers after step (1).
[0019] Preferably, the precursor impregnation and pyrolysis process in step (3) includes: placing the fabric preform in a vacuum impregnation tank, evacuating to -0.08 to -0.1 MPa, and maintaining the vacuum for 10–30 min; then immersing it in a ceramic precursor solution, pressurizing it to 0.5–2.0 MPa, and maintaining the pressure for 1–4 hours; after removal, crosslinking and curing at 100–200 °C for 2–6 hours; then, under an inert atmosphere, heating to 900–1300 °C at a rate of 1–5 °C / min and maintaining the temperature for 1–3 hours for pyrolysis; repeating the impregnation-curing-pyrolysis cycle 3–8 times until the density of the composite material reaches 1.8–2.5 g / cm³. 3 .
[0020] Preferably, the ceramic precursor solution is selected from polycarbosilane / xylene solution, polysilazane / toluene solution or polyborosilazane / xylene solution, with a mass concentration of 30-60% and a molecular weight of 1000-3000.
[0021] Preferably, the process parameters of the plasma treatment in step (4) are: power 100–300W, treatment gas is oxygen or argon, gas flow rate 50–200sccm, treatment time 30–120 seconds, and treatment pressure 10–50Pa; the high-temperature conductive slurry is Ag-Pd alloy slurry, the composition of which is: 70–85wt% Ag-Pd alloy powder, the mass ratio of Ag to Pd is 70:30 to 90:10, the particle size of the alloy powder is 0.5–5μm; 5–15wt% lead-free glass powder, the softening temperature is 550–650℃; 10–20wt% organic carrier, the organic carrier is a mixture of terpineol and ethyl cellulose, the mass ratio is 95:5 to 90:10.
[0022] Preferably, the high-temperature resistant lead wire in step (5) is a platinum wire, a platinum-rhodium alloy wire, or a nickel-based alloy wire with a diameter of 50–200 μm, and is connected by high-temperature conductive adhesive or brazing; the protective coating is a nano-alumina coating, a silicon oxide coating, or a yttrium oxide coating with a thickness of 1–5 μm, and is prepared by sol-gel method or chemical vapor deposition method.
[0023] Preferably, the continuous ceramic fiber in step (1) is selected from at least one of silicon carbide fiber, boron nitride fiber, or alumina fiber; the silicon carbide fiber has a diameter of 10–15 μm and a tensile strength ≥2.8 GPa; the boron nitride fiber has a diameter of 8–12 μm and a tensile strength ≥1.5 GPa; and the alumina fiber has a diameter of 10–20 μm and an Al2O3 content ≥99%.
[0024] The present invention has the following technical effects:
[0025] The high-temperature resistant ceramic fiber composite electronic substrate provided by this invention has precise and controllable process parameters, readily available raw materials, and mature equipment, and has good prospects for industrial application. The resulting product can be used as a substrate and functional integration platform for flexible electronic devices in extreme high-temperature environments, and can be applied in fields such as aerospace engine monitoring systems, hypersonic vehicle radomes, nuclear reactor sensors, and deep well exploration electronic equipment. Detailed Implementation
[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.
[0027] Example 1
[0028] This embodiment provides a preparation process for a high-temperature resistant ceramic fiber composite electronic substrate, the specific steps of which are as follows:
[0029] (1) Construction of gradient interface phase on fiber surface:
[0030] Hi-Nicalon type SiC fibers with a diameter of 12 μm and a tensile strength of 2.8 GPa were used. Three interfacial phases were sequentially deposited on the fiber surface using chemical vapor deposition:
[0031] First, an inner interface layer of PyC was deposited: C3H6 was used as the carbon source with a flow rate of 50 sccm, Ar flow rate of 300 sccm, deposition temperature of 950℃, deposition pressure of 2 kPa, and deposition time of 20 min, resulting in a PyC layer with a thickness of 100 nm.
[0032] Then, a gradient transition layer was deposited: five layers of BN and SiC were deposited alternately in the order of BN / SiC / BN / SiC / BN. The deposition conditions for the BN layer were: BCl3 flow rate 30 sccm, NH3 flow rate 60 sccm, H2 flow rate 200 sccm, deposition temperature 850℃, deposition pressure 2 kPa, deposition time 10 min, and each layer thickness was 150 nm. The deposition conditions for the SiC layer were: trichloromethylsilane flow rate 15 sccm, H2 flow rate 300 sccm, deposition temperature 1000℃, deposition pressure 2 kPa, deposition time 8 min, and each layer thickness was 150 nm.
[0033] Finally, the outer functional layer was deposited: a SiC layer doped with carbon nanotubes. Carbon nanotubes were ultrasonically dispersed in ethanol at a concentration of 0.5 mg / mL and injected into the reaction chamber at a rate of 50 μL / min. They were then co-deposited with trichloromethylsilane. The carbon nanotube content was 3 wt% of the SiC mass. The deposition time was 20 min, and the thickness was 250 nm.
[0034] (2) Fabric prefabrication weaving:
[0035] The fibers processed in step (1) are woven into a bottom layer fabric using a 2.5D weaving process, with a fiber volume fraction of 40%.
[0036] Preparation of aluminum-doped zinc oxide piezoelectric sensing fiber: Zinc oxide powder and aluminum oxide powder were mixed at an Al:Zn molar ratio of 3:100 and reacted in a solid phase at 1200℃ for 4 hours to obtain aluminum-doped zinc oxide ceramic. The ceramic was then melt-spun into fibers with a diameter of 10 μm.
[0037] Piezoelectric sensing fibers are mixed with ordinary SiC fibers in 10mm×10mm areas to form the top functional layer fabric, with a fiber volume fraction of 30%.
[0038] Preparation of interface layer fiber mesh: The SiC fibers treated in step (1) are cut into short fibers with a length of 3-5 mm, and a fiber mesh with a thickness of 80 μm is made by wet web forming process.
[0039] The bottom fabric, the interface layer fiber web, and the top functional layer fabric are stacked in sequence and fixed with carbon fiber stitching to obtain a fabric preform.
[0040] (3) Matrix densification:
[0041] A precursor impregnation-pyrolysis process was employed. The fabric preform was placed in a vacuum impregnation tank, evacuated to -0.095 MPa, and held for 20 min. It was then immersed in a polycarbosilane / xylene solution with a mass concentration of 50% and a molecular weight of 1800, pressurized to 1.2 MPa, and held for 2 hours. After removal, it was cross-linked and cured at 150℃ for 4 hours. Finally, it was pyrolyzed in a tube furnace under a nitrogen atmosphere, with the temperature increased to 1100℃ at a rate of 3℃ / min and held for 2 hours. This impregnation-curing-pyrolysis cycle was repeated 5 times, resulting in a final composite material density of 2.2 g / cm³. 3 .
[0042] (4) Circuit printing and sintering:
[0043] Plasma treatment was performed on the top surface of the densified composite material: power 200W, oxygen flow rate 100sccm, treatment time 60 seconds, and treatment pressure 30Pa.
[0044] Preparation of Ag-Pd conductive paste: Ag-Pd alloy powder with an Ag to Pd mass ratio of 80:20, a particle size of 1-3 μm, and a content of 80 wt%; lead-free glass powder with a softening temperature of 600℃ and a content of 8 wt%; and an organic carrier consisting of a mixture of terpineol and ethyl cellulose with a mass ratio of 92:8 and a content of 12 wt%. The paste is rolled four times using a three-roll mill.
[0045] The conductive paste was printed onto the top surface using screen printing technology with a screen mesh count of 300, a squeegee pressure of 0.3 MPa, and a printing speed of 100 mm / s, resulting in a printing thickness of 20 μm. The mixture was then sintered in a chain sintering furnace under air atmosphere, with the temperature increased to 900 °C at a rate of 10 °C / min and held for 20 minutes.
[0046] (5) Electrode connection and packaging:
[0047] At the electrode location in the heat damage sensing area, a platinum wire with a diameter of 100 μm is connected using high-temperature conductive silver paste. The curing temperature is 250℃ and the curing time is 30 min.
[0048] A nano-alumina protective coating was applied using the sol-gel method: aluminum alkoxide was hydrolyzed to obtain alumina sol, which was then dipped into the coating and heat-treated at 500℃ for three times, resulting in a coating thickness of 3μm.
[0049] The electronic substrate fabric prepared in this embodiment was tested and found to have a maximum operating temperature of 1250℃, a flexural strength of 385 MPa, and a fracture toughness of 13.5 MPa·m.1 / 2 It has a volume resistivity of 5.2×10¹²Ω·cm, a thermal conductivity of 18.5W / (m·K), and a strength retention rate of 88% after 50 thermal cycles from 1000℃ to room temperature.
[0050] Example 2
[0051] This embodiment is basically the same as embodiment 1, except that the structure and deposition parameters of the gradient interface phase in step (1) are different.
[0052] The inner interface layer uses BN:BCl3 flow rate 40 sccm, NH3 flow rate 80 sccm, H2 flow rate 300 sccm, deposition temperature 900℃, deposition pressure 2 kPa, deposition time 25 min, and thickness 120 nm.
[0053] The gradient transition layer consists of 7 alternating layers in the order of BN / SiC / BN / SiC / BN / SiC / BN, with each layer having a thickness of 100 nm. The deposition time for the BN layer is 8 min, and the deposition time for the SiC layer is 5 min.
[0054] The outer functional layer is a BaTiO3-doped BN layer: Ba(TiO(C4H9))3 and BCl3-NH3-H2 system are co-deposited with a Ba(TiO(C4H9))3 flow rate of 5 sccm, a BCl3 flow rate of 30 sccm, an NH3 flow rate of 60 sccm, an H2 flow rate of 200 sccm, a deposition temperature of 800℃, a deposition time of 25 min, a thickness of 300 nm, and a Ba:Ti:B:N molar ratio of 1:1:15:15.
[0055] In step (4), inkjet printing technology is used to print the circuit: printhead temperature 40℃, substrate temperature 50℃, printing resolution 600dpi, 2 layers are printed, sintering temperature is 920℃, and heat preservation is 15 minutes.
[0056] The electronic substrate fabric prepared in this embodiment was tested and found to have a maximum operating temperature of 1220℃, a flexural strength of 372 MPa, and a fracture toughness of 14.2 MPa·m. 1 / 2 The volume resistivity is 3.8×10¹²Ω·cm, the thermal conductivity is 17.2W / (m·K), the dielectric constant of the transparent region is 3.8, and the dielectric loss is 0.004.
[0057] Example 3
[0058] This embodiment is basically the same as embodiment 1, except that the functional design of the thermal damage sensing area and the electromagnetic control area is added in step (2).
[0059] Thermal damage sensing area: Four 5mm × 5mm aluminum-doped zinc oxide piezoelectric sensing fiber regions are woven into the top layer fabric, located at the four corners of the substrate, and led out through platinum wire electrodes pre-embedded in the bottom layer. The platinum wire has a diameter of 50μm. The preparation of the piezoelectric sensing fibers is the same as in Example 1.
[0060] Electromagnetic control zone: Two 20mm×20mm areas are designed in the top layer fabric, namely the electromagnetic shielding zone and the wave-transmitting zone. The electromagnetic shielding zone is woven with carbon-doped SiBCN electromagnetic control fibers; the wave-transmitting zone is woven with high-purity alumina fibers. Preparation of carbon-doped SiBCN electromagnetic control fibers: Using polyborosilicate as a precursor, 10wt% carbon nanotubes are added, and fibers are produced by melt spinning, non-melting treatment, and high-temperature pyrolysis. The non-melting treatment conditions are air oxidation at 200℃ for 2 hours, and the high-temperature pyrolysis conditions are nitrogen atmosphere at 1200℃ for 1 hour. The fiber diameter is 12μm.
[0061] Step (3) Densification process using chemical vapor infiltration: The fabric preform is placed in a CVI reaction chamber, evacuated to 200 Pa, and heated to 1000 °C; trichloromethylsilane is introduced at a flow rate of 100 sccm, H2 flow rate is 500 sccm, deposition pressure is 5 kPa, deposition time is 120 hours, weight gain rate is 0.3 g / h, and final density is 2.3 g / cm³. 3 .
[0062] The electronic substrate fabric prepared in this embodiment was tested and found to have the following thermal damage sensing performance: when locally heated to 800℃, the sensing area generates a piezoelectric signal of 0.8-1.2mV, with a damage location accuracy of ±1.5mm; when microcracks are generated, the signal strength increases to 2.5-3.5mV. The electromagnetic shielding performance is as follows: shielding effectiveness of 28-32dB in the X-band shielding area, dielectric constant of 3.6-3.9 in the transparent area, and dielectric loss of 0.003-0.005. The bending strength is 356MPa, and the fracture toughness is 13.8MPa·m. 1 / 2 .
[0063] Example 4
[0064] This embodiment is basically the same as embodiment 1, except that the number of layers and thickness of the gradient interface phase in step (1) are different.
[0065] Five groups of samples with different interfacial phase parameters were set up:
[0066] Sample A: Inner layer PyC 100nm + 5 gradient layers each 150nm + outer functional layer 250nm
[0067] Sample B: Only inner layer PyC 100nm, no gradient layer or outer functional layer
[0068] Sample C: Inner layer PyC 100nm + monolayer BN 300nm
[0069] Sample D: Inner layer PyC 100nm + 3 gradient layers each 100nm + outer functional layer 200nm
[0070] Sample E: Inner layer PyC 100nm + 7 gradient layers each 200nm + outer functional layer 400nm
[0071] The other preparation steps for each sample are the same as in Example 1.
[0072] The test results are shown in Table 1. Sample A has the best combination of mechanical properties, with the highest bending strength and fracture toughness.
[0073] Example 5
[0074] This embodiment is basically the same as embodiment 3, except that the composition of the conductive paste and the printing parameters are different in step (4).
[0075] Three groups of samples with different slurry formulations were prepared:
[0076] Sample F: Ag-Pd alloy powder, with an Ag to Pd mass ratio of 80:20 and a content of 80 wt%, glass powder 8 wt%, organic carrier 12 wt%, and sintering temperature of 900℃.
[0077] Sample G: Ag-Pd alloy powder, with an Ag to Pd mass ratio of 70:30 and a content of 75 wt%, 10 wt% glass powder, 15 wt% organic carrier, and a sintering temperature of 850℃.
[0078] Sample H: Pure Ag powder, content 80wt%, glass powder 8wt%, organic carrier 12wt%, sintering temperature 900℃
[0079] The resistance and high-temperature stability of the test circuit were measured with a line width of 100μm and a length of 10mm.
[0080] The test results are shown in Table 2. The Ag-Pd alloy systems of samples F and G have better high-temperature stability than pure Ag.
[0081] Comparative Example 1
[0082] This comparative example is basically the same as Example 1, except that the fiber surface interface phase is not constructed in step (1), that is, uncoated SiC fibers are directly used for weaving.
[0083] The prepared composite material was tested and found to have a flexural strength of 185 MPa and a fracture toughness of 4.2 MPa·m. 1 / 2 Fracture surface examination showed minimal fiber pull-out, exhibiting brittle fracture characteristics. Obvious cracks appeared after 10 cycles of thermal cycling at 1000℃, and the strength decreased to 112 MPa.
[0084] Comparative Example 2
[0085] This comparative example is basically the same as Example 1, except that in step (1), only a single layer of PyC interface phase is deposited with a thickness of 150 nm, without a gradient transition layer and an external functional layer.
[0086] The prepared composite material has a flexural strength of 268 MPa and a fracture toughness of 7.5 MPa·m. 1 / 2 It is superior to Comparative Example 1, but still significantly lower than Example 1. Fracture surface observation shows some fiber pull-out, but the pull-out length is short. After 50 cycles of thermal cycling at 1000°C, the strength retention rate is 71%.
[0087] Comparative Example 3
[0088] This comparative example is basically the same as Example 1, except that the gradient transition layer in step (1) uses a single SiC material instead of an alternating BN / SiC structure, and the total thickness is 750nm.
[0089] The prepared composite material has a flexural strength of 312 MPa and a fracture toughness of 9.8 MPa·m. 1 / 2 It is superior to Comparative Example 2, but still inferior to Example 1. The strength retention rate after 50 thermal cycles is 79%.
[0090] Comparative Example 4
[0091] This comparative example is basically the same as Example 3, except that it does not have an electromagnetic control area and the top layer is entirely made of ordinary SiC fiber weaving.
[0092] The prepared composite material has an electromagnetic shielding effectiveness of 3-5 dB in the X-band, with no obvious shielding effect; the dielectric constant is 5.2-5.8 and the dielectric loss is 0.01-0.02, which does not meet the requirements for wave transmission.
[0093] Comparative Example 5
[0094] This comparative example is basically the same as Example 3, except that in step (4), ordinary polymer conductive paste is used to print the circuit, and the conductive paste is a silver / epoxy resin system.
[0095] After printing, the conductive circuit resistance increased from the initial 0.5Ω / cm to an open circuit state after aging in air at 300℃ for 24 hours, and the conductive paste carbonized and fell off.
[0096] Experimental data
[0097] Table 1 Comparison of mechanical properties of different interfacial phase structures (Example 4)
[0098] Table 2 Comparison of circuit performance of different conductive pastes (Example 5)
[0099] Table 3. Comparison of overall performance between the examples and comparative examples.
[0100] Table 4. Test results of thermal damage sensing performance (Example 3)
[0101] Table 5 Comparison of different densification processes
[0102] The high-temperature resistant ceramic fiber composite electronic substrate provided by this invention has precise and controllable process parameters, readily available raw materials, and mature equipment, and has good prospects for industrial application. The resulting product can be used as a substrate and functional integration platform for flexible electronic devices in extreme high-temperature environments, and can be applied in fields such as aerospace engine monitoring systems, hypersonic vehicle radomes, nuclear reactor sensors, and deep well exploration electronic equipment.
[0103] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.
Claims
1. A preparation process for a high-temperature resistant ceramic fiber composite electronic substrate, characterized in that, Includes the following steps: Step (1): An inner interface layer, a gradient transition layer, and an outer functional layer are sequentially deposited on the surface of continuous ceramic fibers using chemical vapor deposition to form a multilayer gradient interface phase. The inner interface layer is a pyrolytic carbon layer or a boron nitride layer with a thickness of 50–200 nm. The gradient transition layer consists of 3–7 alternating layers of SiC and BN, each with a thickness of 100–500 nm. The outer functional layer is a SiC layer doped with carbon nanotubes or a BN layer doped with BaTiO3 with a thickness of 200–400 nm. Step (2): The fibers processed in step (1) are woven into a bottom layer fabric using a three-dimensional weaving process. At the same time, ceramic fibers doped with functional nanophases are mixed with ordinary ceramic fibers according to a preset pattern to form a top layer functional fabric with circuit printing area, thermal damage sensing area and electromagnetic control area. Then, the bottom layer fabric and the top layer functional fabric are stacked and fixed to obtain a fabric preform. Step (3): The fabric preform obtained in step (2) is densified by using a precursor impregnation pyrolysis process or a chemical vapor infiltration process to obtain a ceramic matrix composite material; Step (4): Plasma treatment is performed on the top surface of the ceramic matrix composite material obtained in step (3), and then high-temperature resistant conductive paste is printed on the top surface according to the design pattern using inkjet printing or screen printing technology, and conductive circuits are formed by high-temperature sintering. Step (5): Connect high-temperature resistant leads to the electrode positions in the heat damage sensing area and coat the entire surface with a protective coating.
2. The preparation process of the high-temperature resistant ceramic fiber composite electronic substrate according to claim 1, characterized in that, The deposition conditions for the gradient transition layer in step (1) are as follows: the BN layer adopts the BCl3-NH3-H2 system, with a BCl3 flow rate of 20–50 sccm, an NH3 flow rate of 50–100 sccm, an H2 flow rate of 100–300 sccm, a deposition temperature of 700–1000℃, and a deposition pressure of 1–5 kPa; the SiC layer adopts the trichloromethylsilane-H2 system, with a trichloromethylsilane flow rate of 10–30 sccm, an H2 flow rate of 100–500 sccm, a deposition temperature of 900–1100℃, and a deposition pressure of 1–5 kPa; the deposition rate is controlled at 5–20 nm / min.
3. The preparation process of the high-temperature resistant ceramic fiber composite electronic substrate according to claim 1, characterized in that, The outer functional layer in step (1) is a SiC layer doped with carbon nanotubes. Its deposition conditions are as follows: carbon nanotubes are dispersed in ethanol, ultrasonically dispersed for 30–60 min, and introduced into the reaction chamber together with trichloromethylsilane. The carbon nanotube content is 1–5 wt% of the mass of SiC. Alternatively, the outer functional layer is a BN layer doped with BaTiO3. Its deposition conditions are as follows: Ba(TiO(C4H9))3 and BCl3-NH3-H2 system are co-deposited, and the molar ratio of Ba:Ti:B:N is controlled between 1:1:10:10 and 1:1:20:
20.
4. The preparation process of the high-temperature resistant ceramic fiber composite electronic substrate according to claim 1, characterized in that, The ceramic fibers doped with functional nanophases in step (2) include aluminum-zinc oxide piezoelectric sensing fibers and carbon-SiBCN electromagnetic control fibers; the molar ratio of Al to Zn in the aluminum-zinc oxide piezoelectric sensing fibers is 2–5:100; and the mass fraction of carbon nanotubes or graphene in the carbon-SiBCN electromagnetic control fibers is 5–15%.
5. The preparation process of the high-temperature resistant ceramic fiber composite electronic substrate according to claim 1, characterized in that, The three-dimensional weaving process described in step (2) is 2.5D weaving or three-dimensional interlocking weaving; the fiber volume fraction of the bottom fabric is 35-50%, and the fiber volume fraction of the top functional layer fabric is 25-40%; an interface layer fiber web with a thickness of 50-100μm is also laid between the bottom fabric and the top functional layer fabric, and the interface layer fiber web is made by wet web forming process from the short chopped fibers after step (1).
6. The preparation process of the high-temperature resistant ceramic fiber composite electronic substrate according to claim 1, characterized in that, The precursor impregnation and pyrolysis process described in step (3) includes: placing the fabric preform in a vacuum impregnation tank, evacuating to -0.08 to -0.1 MPa, and maintaining the vacuum for 10–30 min; then immersing it in a ceramic precursor solution, pressurizing it to 0.5–2.0 MPa, and maintaining the pressure for 1–4 hours; after removal, crosslinking and curing at 100–200℃ for 2–6 hours; then, under an inert atmosphere, heating to 900–1300℃ at a rate of 1–5℃ / min and maintaining the temperature for 1–3 hours for pyrolysis; repeating the impregnation-curing-pyrolysis cycle 3–8 times until the density of the composite material reaches 1.8–2.5 g / cm³. 3 .
7. The preparation process of the high-temperature resistant ceramic fiber composite electronic substrate according to claim 6, characterized in that, The ceramic precursor solution is selected from polycarbosilane / xylene solution, polysilazane / toluene solution or polyborosilazane / xylene solution, with a mass concentration of 30-60% and a molecular weight of 1000-3000.
8. The preparation process of the high-temperature resistant ceramic fiber composite electronic substrate according to claim 1, characterized in that, The process parameters for plasma treatment in step (4) are: power 100–300W, treatment gas is oxygen or argon, gas flow rate 50–200sccm, treatment time 30–120 seconds, and treatment pressure 10–50Pa; the high-temperature conductive slurry is Ag-Pd alloy slurry, which is composed of: 70–85wt% Ag-Pd alloy powder, with a mass ratio of Ag to Pd of 70:30 to 90:10 and an alloy powder particle size of 0.5–5μm; 5–15wt% lead-free glass powder, with a softening temperature of 550–650℃; and 10–20wt% organic carrier, which is a mixture of terpineol and ethyl cellulose with a mass ratio of 95:5 to 90:
10.
9. The preparation process of the high-temperature resistant ceramic fiber composite electronic substrate according to claim 1, characterized in that, The high-temperature resistant lead wire mentioned in step (5) is a platinum wire, a platinum-rhodium alloy wire or a nickel-based alloy wire with a diameter of 50–200 μm, and is connected by high-temperature conductive adhesive or brazing; the protective coating is a nano-alumina coating, a silicon oxide coating or a yttrium oxide coating with a thickness of 1–5 μm, and is prepared by sol-gel method or chemical vapor deposition method.
10. The preparation process of the high-temperature resistant ceramic fiber composite electronic substrate according to claim 1, characterized in that, The continuous ceramic fiber in step (1) is selected from at least one of silicon carbide fiber, boron nitride fiber or alumina fiber; the silicon carbide fiber has a diameter of 10–15 μm and a tensile strength ≥2.8 GPa; the boron nitride fiber has a diameter of 8–12 μm and a tensile strength ≥1.5 GPa; the alumina fiber has a diameter of 10–20 μm and an Al2O3 content ≥99%.