A carbon-carbon composite material, a preparation method and application thereof, and a carbon-carbon composite material PECVD bearing frame

Abstract

The application provides a carbon-carbon composite material and a preparation method and application thereof, and a carbon-carbon composite material PECVD bearing frame, and relates to the technical field of carbon materials. The application utilizes poly-nitrogen-silane to enhance the cross-linking between layers of the carbon-carbon bearing frame, can effectively prevent the interlayer cracking of the material, and converts into silicon carbide in the subsequent carbonization process, significantly improves the mechanical properties of the material, and the carbon-carbon composite material PECVD bearing frame prepared through machining has excellent mechanical properties, can adapt to the complex process environment of PECVD, is not easy to be damaged, has a low replacement frequency, and has a long service period. Moreover, the application adopts resin, poly-nitrogen-silane and pitch as the impregnation material of the carbon cloth, has the advantages of low cost and high preparation efficiency compared with other similar net tire needle punching or Z-direction reinforced plate materials. The carbon-carbon composite material PECVD bearing frame prepared through machining of the carbon-carbon composite material prepared by the application has the advantages of low density, high strength and designable size.

Description

Technical Field

[0001] This invention belongs to the field of carbon materials technology, specifically relating to a carbon-carbon composite material, its preparation method and application, and a carbon-carbon composite material PECVD support frame. Background Technology

[0002] With the increasingly strong momentum of new energy development, the photovoltaic solar power generation industry has been listed as a key development project in many countries, and solar cell module systems have also received increasing attention. In the production process of monocrystalline / polycrystalline silicon cells, film deposition on silicon wafers is a crucial step, reducing light reflection and improving light utilization. Currently, the most widely used silicon nitride thin film process is plasma-enhanced chemical vapor deposition (PECVD). PECVD uses microwaves or radio frequency to create a localized plasma containing the atoms that make up the thin film. This plasma is highly chemically reactive and readily reacts, depositing the desired thin film onto the substrate.

[0003] Given the complex process environment of PECVD, the PECVD boats or boat plates generally used are mainly made of graphite. Graphite products have the characteristics of low impurity content, high purity, high corrosion resistance, high thermal conductivity, moderate electrical conductivity, and stable physicochemical properties. However, in practical applications, due to the poor mechanical properties of graphite, graphite boats are easily damaged during coating and cleaning processes, resulting in a short service life. Traditional graphite support frames (boats) are made by machining a whole graphite plate and then adding related accessories. Researchers mainly optimize the structural details of graphite support frames to improve load-bearing capacity, thereby improving PECVD production efficiency. For example, Chinese patent CN206858654U discloses a graphite frame for plate PECVD, which adjusts the graphite mesh from the original 5mm*10mm to 5mm*11mm, increasing the load-bearing capacity of the graphite frame by 10%, increasing production efficiency by 10%, reducing energy and material consumption, and lowering production costs. Chinese patent CN203593784U discloses a graphite frame with carbon fiber reinforcing plates at its upper and lower edges. These plates, flush with the frame body, provide support and prevent the reddish-white discoloration caused by the influence of existing graphite fixing plates on the uniformity of airflow during coating, thus ensuring the quality of the solar cell coating. Existing graphite carrier frames are mainly made by machining graphite sheets and adding corresponding accessories. However, their construction is limited by the structural design of the carrier frame and the material properties of graphite itself. The potential for increasing silicon wafer loading capacity is limited, and the frame is easily damaged in harsh coating environments and pickling processes, significantly increasing the frequency of replacement and the cost of the PECVD process. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a carbon-carbon composite material, its preparation method and application, and a carbon-carbon composite PECVD support frame. The carbon-carbon composite material and the carbon-carbon composite PECVD support frame provided by this invention have high strength, excellent mechanical properties, can adapt to the complex process environment of PECVD, are not easily damaged, have low replacement frequency, and a long service life.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0006] This invention provides a method for preparing carbon-carbon composite materials, comprising the following steps:

[0007] Carbon is impregnated in a resin solution to obtain a prepreg;

[0008] A polynitrosilane solution is coated onto the surface of the prepreg to obtain a polynitrosilane prepreg. Several layers of the polynitrosilane prepreg are laid up to obtain a laminated polynitrosilane prepreg. The laminated polynitrosilane prepreg is then molded to obtain a resin-impregnated molded board.

[0009] The impregnated molded plate is subjected to a first carbonization process to obtain a carbonized plate.

[0010] The carbonized board is placed in asphalt for liquid phase impregnation followed by a second carbonization to obtain a liquid phase impregnated carbonized board.

[0011] The liquid-phase impregnated carbonized plate is then graphitized to obtain a carbon-carbon composite material.

[0012] Preferably, the parameters of the carbon cloth include: a basis weight of 300–420 g / m². 2 The texture is plain or twill, and the carbon wire specifications are 12-48K.

[0013] The resin impregnation solution used is in the form of a resin solution; the resin solution includes resin and solvent; the resin includes one or more of phenolic resin, furan resin and benzoxazine resin; the solvent includes ethanol; the mass ratio of resin to solvent is 100:10-20;

[0014] The resin content in the prepreg is 30-45 wt%.

[0015] Preferably, the polynitrosilane solution comprises a polynitrosilane and a solvent; the number-average molecular weight of the polynitrosilane is 8000–15000; the solvent comprises styrene; and the concentration of the polynitrosilane solution is 70–85 wt%.

[0016] The mass ratio of the prepreg to the polynitrosilane is 100:3-5;

[0017] The thickness of a single layer of the polynitrosilane prepreg is 0.4–0.5 mm;

[0018] The thickness of the laminated polynitrosilane prepreg is 3–20 mm;

[0019] The molding is segmented molding, which includes sequentially performing a first heating molding, a first heat preservation molding, a second heating molding, a second heat preservation molding, a third heating molding, and a third heat preservation molding;

[0020] The heating rate of the first heating molding is 1.2 to 1.3 °C / min, and the pressure is 0 MPa;

[0021] The temperature of the first thermal insulation molding is 110℃. The first thermal insulation molding includes sequentially performing a first holding pressure, a pressure increase, and a second holding pressure. The pressure of the first holding pressure is 0 MPa, and the time is 30 min. The pressure increase is performed at 0.2-0.3 MPa intervals of 2 min, and the final pressure after the pressure increase is 0.8 MPa. The pressure of the second holding pressure is 0.8 MPa, and the time is 3 min.

[0022] The heating rate of the second heating molding is 0.8℃ / min, and the pressure is 0.8MPa;

[0023] The second heat-insulating molding temperature is 150℃, the time is 30min, and the pressure is 0.8MPa;

[0024] The heating rate of the third heating molding is 0.5℃ / min, and the pressure is 0.8MPa;

[0025] The temperature of the third heat-insulating molding is 180℃, the time is 85 minutes, and the pressure is 0.8MPa.

[0026] Preferably, the first carbonization is performed by placing the resin-impregnated molding plate between two graphite plate fixtures.

[0027] The first carbonization includes sequentially performing a first heating carbonization, a first heat preservation carbonization, a second heating carbonization, a second heat preservation carbonization, a third heating carbonization, and a third heat preservation carbonization;

[0028] The first heating and carbonization time is 3-4 hours;

[0029] The temperature for the first heat preservation carbonization is 190-210℃, and the heat preservation time is 2-3 hours;

[0030] The second heating and carbonization time is 13-15 hours;

[0031] The second heat preservation carbonization temperature is 600-610℃, and the heat preservation time is 2-3 hours;

[0032] The third heating and carbonization time is 4-5 hours;

[0033] The third heat preservation carbonization temperature is 800-810℃, and the heat preservation time is 2-3 hours.

[0034] Preferably, the liquid phase impregnation process conditions include: a temperature of 160–210°C, a pressure of 2–4 MPa, a time of 2–4 h, and the equipment used is a vacuum pressure impregnation furnace;

[0035] The liquid phase impregnation process also includes cooling to ≤90°C;

[0036] The number of times the second carbonization is carried out after liquid phase impregnation is 1 to 4;

[0037] The second carbonization process includes sequentially heating, holding, and cooling; the heating rate is 10–100°C / h; the holding temperature is 950–1100°C for 1–3 hours; and the cooling rate is 50–100°C / h.

[0038] The density of the liquid-phase impregnated carbonized plate is ≥1.5 g / cm³. 3 .

[0039] Preferably, the graphitization treatment is performed at a temperature of 1800–2300°C for 2–4 hours.

[0040] The present invention provides a carbon-carbon composite material prepared by the preparation method described in the above technical solution.

[0041] This invention provides the application of the carbon-carbon composite material described in the above technical solution in plasma-enhanced chemical vapor deposition.

[0042] This invention provides a carbon-carbon composite PECVD support frame, which is obtained by machining the carbon-carbon composite material described in the above technical solution.

[0043] Preferably, the carbon-carbon composite PECVD support frame is a flat frame grid structure, and the grid arrangement in the carbon-carbon composite PECVD support frame is (4~5)×(4~8), with a thickness of 3~20mm.

[0044] Existing methods increase strength by improving the density and size of the graphite support frame or by adding carbon fiber reinforcement plates at the upper and lower edges of the graphite frame. However, these methods do not fundamentally address the problem of graphite's inherent low strength and susceptibility to damage, thus significantly increasing the replacement frequency and cost of the support frame. The preparation method provided by this invention utilizes polynitrosilane to enhance the interlayer crosslinking of the carbon-carbon support frame, effectively preventing interlayer cracking of traditional graphite materials. Furthermore, during the graphitization process, polynitrosilane is converted into silicon carbide, significantly improving the mechanical properties of the carbon-carbon material. The resulting carbon-carbon composite PECVD support frame exhibits excellent mechanical properties, can withstand the complex process environment of PECVD, is not easily damaged, has a low replacement frequency, and a long service life. Moreover, this invention uses resin, polynitrosilane, and pitch as impregnation materials for the carbon cloth, increasing the material's density and strength. Compared to other similar mesh-reinforced or Z-axis reinforced sheets, it has significant advantages in terms of low cost and high preparation efficiency. Compared to traditional graphite support frames, the carbon-carbon composite PECVD support frame prepared by this invention, after machining, has advantages such as low density, high strength, and customizable dimensions. The preparation method provided by this invention is simple to operate, low in cost, and suitable for industrial production.

[0045] Furthermore, the present invention uses carbon cloth with large tows of carbon fiber as the initial raw material, which can significantly reduce the material cost of the load-bearing frame and increase the company's profits.

[0046] The carbon-carbon composite PECVD support frame provided by this invention, made from carbon-carbon materials through machining, has excellent mechanical properties, can adapt to the complex process environment of PECVD, is not easily damaged, has a low replacement frequency, and a long service life. Attached Figure Description

[0047] Figure 1 This is a schematic diagram of a grease impregnation equipment, where 1-impregnation tank, 2-movable door, 3-jacket layer, 4-insulation layer, 5-heating medium inlet valve, 6-heating medium outlet valve, 7-discharge valve, 8-vacuum pump, 9-condenser, 10-storage container, 11-vacuum gauge, 12-level gauge, and 13-booster pump.

[0048] Figure 2 A schematic diagram of the structure of the carbon-carbon composite PECVD support frame prepared for the example. Detailed Implementation

[0049] This invention provides a method for preparing carbon-carbon composite materials, comprising the following steps:

[0050] Carbon is impregnated in a resin solution to obtain a prepreg;

[0051] A polynitrosilane solution is coated onto the surface of the prepreg to obtain a polynitrosilane prepreg. Several layers of the polynitrosilane prepreg are then laid up to obtain a laminated polynitrosilane prepreg.

[0052] The laminated polynitrosilane prepreg is molded to obtain an impregnated molded plate;

[0053] The impregnated molded plate is subjected to a first carbonization process to obtain a carbonized plate.

[0054] The carbonized board is placed in asphalt for liquid phase impregnation followed by a second carbonization to obtain a liquid phase impregnated carbonized board.

[0055] The liquid-phase impregnated carbonized plate is then graphitized to obtain a carbon-carbon composite material.

[0056] Unless otherwise specified, all materials and equipment used in this invention are commercially available products in the field.

[0057] The present invention involves impregnating carbon in a resin solution to obtain a prepreg.

[0058] In this invention, the parameters of the carbon cloth include: the preferred basis weight is 300-420 g / m². 2 More preferably, it is 320–410 g / m 2 The preferred texture is plain or twill; the preferred carbon fiber specification is 12-48K, more preferably 24-48K.

[0059] In this invention, the resin solution preferably comprises a resin and a solvent; the resin preferably comprises one or more of phenolic resin, furan resin, and benzoxazine resin, more preferably phenolic resin; the solvent preferably comprises ethanol, and the purity of the ethanol is preferably ≥95%; the mass ratio of resin to solvent in the resin solution is preferably 100:10-20, more preferably 10:15; the viscosity of the resin solution is preferably 2000-8000 Pa·s, more preferably 2000-5000 Pa·s. In this invention, the resin solution is preferably obtained by mixing resin and solvent, the mixing temperature is preferably 25-30°C, the mixing is preferably mechanical mixing, and this invention does not have a special limitation on the mixing time, as long as a resin solution with a viscosity of 2000-8000 Pa·s can be obtained.

[0060] In this invention, the equipment used for resin impregnation is preferably a grease impregnation device, such as... Figure 1 As shown, 1-Immersion tank, 2-Movable door, 3-Jacket layer, 4-Insulation layer, 5-Heating medium inlet valve, 6-Heating medium outlet valve, 7-Discharge valve, 8-Vacuum pump, 9-Condenser, 10-Storage container, 11-Vacuum gauge, 12-Level gauge, 13-Booster pump.

[0061] In this invention, the resin content in the prepreg is preferably 30-45 wt%, more preferably 35-40 wt%. In this invention, the prepreg is preferably molded within one month of preparation; when the prepreg is not used within 10 days, it is preferably sealed and stored at -18°C, and the shelf life of the prepreg is preferably six months.

[0062] After obtaining the prepreg, the present invention coats the surface of the prepreg with a polynitrosilane solution to obtain a polynitrosilane prepreg, and lays up several layers of the polynitrosilane prepreg to obtain a laminated polynitrosilane prepreg.

[0063] In this invention, the prepreg is preferably cut before use, and the cutting is preferably done using a CNC automatic fabric cutting machine. The efficiency of the CNC automatic fabric cutting machine is preferably 1700 mm / s. The size and quantity of the cut prepreg are preferably determined according to actual needs. The size error of the cut prepreg is preferably ±1 mm.

[0064] In this invention, the polynitrosilane solution preferably comprises polynitrosilane and a solvent; the number average molecular weight of the polynitrosilane is preferably 8000-15000, more preferably 10000-12000; the solvent preferably comprises styrene; the concentration of the polynitrosilane solution is preferably 70-85 wt%, more preferably 75-80 wt%.

[0065] In this invention, the mass ratio of the prepreg to the polynitrosilane is preferably 100:3 to 5, and more preferably 100:3 to 4.

[0066] In this invention, the thickness of a single layer of the polynitrosilane prepreg is preferably 0.4-0.5 mm, more preferably 0.42-0.48 mm, and even more preferably 0.45 mm.

[0067] In this invention, the thickness of the laminated polynitrosilane prepreg is preferably 3-20 mm, more preferably 5-15 mm, and even more preferably 8-12 mm.

[0068] In this invention, the support molds used for coating and layup are preferably steel plates. The surface of the support mold is preferably coated with a release agent before use. This invention does not have a specific limitation on the release agent; any release agent well-known to those skilled in the art can be used. Specifically, the coating and layup are preferably performed as follows: a release agent is applied to the surface of the steel plate; the prepreg is evenly and smoothly laid on the surface of the steel plate; each layer is smoothed with a plastic scraper; a polynitrosilane solution is sprayed onto the surface of the prepreg using a spray adhesive device; layers are laid one by one; after all layers are laid, the upper surface of the last layer of polynitrosilane prepreg is covered with the steel plate coated with the release agent, and then subsequent molding is performed.

[0069] After obtaining the laminated polynitrosilane prepreg, the present invention molds the laminated polynitrosilane prepreg to obtain an impregnated molded plate. In the present invention, the molding is preferably segmented molding, which preferably includes sequentially performing a first heating molding, a first heat-holding molding, a second heating molding, a second heat-holding molding, a third heating molding, and a third heat-holding molding. In the present invention, the heating rate of the first heating molding is preferably 1.2–1.3 °C / min, and the pressure is preferably 0 MPa. In the present invention, the temperature of the first heat-holding molding is preferably 110 °C, and the first heat-holding molding preferably includes sequentially performing a first pressure holding, a pressure increase, and a second pressure holding; the pressure of the first pressure holding is preferably 0 MPa, and the time is preferably 30 min; the pressure increase is preferably 0.2–0.3 MPa at 2-minute intervals, and the final pressure after the pressure increase is preferably 0.8 MPa; the pressure of the second pressure holding is preferably 0.8 MPa, and the time is preferably 3 min. In this invention, the heating rate of the second heating molding is preferably 0.8℃ / min, and the pressure is preferably 0.8MPa. In this invention, the temperature of the second heat-holding molding is preferably 150℃, the time is preferably 30min, and the pressure is preferably 0.8MPa. In this invention, the heating rate of the third heating molding is preferably 0.5℃ / min, and the pressure is preferably 0.8MPa. In this invention, the temperature of the third heat-holding molding is preferably 180℃, the time is preferably 85min, and the pressure is preferably 0.8MPa.

[0070] After obtaining the impregnated molding plate, the present invention performs a first carbonization on the impregnated molding plate to obtain a carbonized sheet. In the present invention, the first carbonization is preferably performed by placing the impregnated molding plate between two graphite plate fixtures. In the present invention, the first carbonization preferably includes sequentially performing a first heating carbonization, a first holding carbonization, a second heating carbonization, a second holding carbonization, a third heating carbonization, and a third holding carbonization. In the present invention, the first heating carbonization time is preferably 3-4 hours, more preferably 3-3.5 hours, and the final temperature of the first heating carbonization is the same as the temperature of the first holding carbonization. In the present invention, the temperature of the first holding carbonization is preferably 190-210°C, more preferably 195-200°C; the holding time of the first holding carbonization is preferably 2-3 hours, more preferably 2-2.5 hours. In the present invention, the second heating carbonization time is preferably 13-15 hours, more preferably 14-15 hours; the temperature of the second heating carbonization is the same as the temperature of the second holding carbonization. In this invention, the temperature of the second heat-insulating carbonization is preferably 600-610℃, more preferably 600-605℃; the heat-insulating time of the second heat-insulating carbonization is preferably 2-3 hours, more preferably 2-2.5 hours. In this invention, the time of the third heating carbonization is preferably 4-5 hours, more preferably 4-4.5 hours; the temperature of the third heating carbonization is the same as the temperature of the third heat-insulating carbonization. In this invention, the temperature of the third heat-insulating carbonization is preferably 800-810℃, more preferably 800-805℃; the heat-insulating time of the third heat-insulating carbonization is preferably 2-3 hours, more preferably 2-2.5 hours. In this invention, the pressure of the first carbonization is preferably slightly positive, more preferably 30-90 kPa, and even more preferably 50-60 kPa; the first carbonization is preferably carried out under a protective atmosphere, which preferably includes nitrogen, argon, or helium; the apparatus used for the first carbonization preferably includes a carbonization furnace; during the first carbonization process, the resin is converted into resin carbon.

[0071] In this invention, the first carbonization process preferably includes cooling to 200°C. Specifically, the protective atmosphere valve is closed, and the furnace cover is opened when the furnace temperature drops to 200°C. This invention does not have any special limitations on the cooling process, and any cooling method known to those skilled in the art can be used, such as furnace-side cooling.

[0072] After obtaining the carbonized board, the present invention places the carbonized board in asphalt for liquid phase impregnation followed by a second carbonization to obtain a liquid phase impregnated carbonized board.

[0073] In this invention, the process conditions for liquid-phase impregnation include: a temperature preferably of 160–210°C, more preferably 170–200°C, and even more preferably 180–190°C; a pressure preferably of 2–4 MPa, more preferably 2.5–3.5 MPa, and even more preferably 3 MPa; a time preferably of 2–4 h, more preferably 2.5–3.5 h, and even more preferably 3 h; and the preferred equipment is a vacuum pressure impregnation furnace. Specifically, the carbonized board is placed in the vacuum pressure impregnation furnace, heated to 160–210°C, and the asphalt is completely drawn into the furnace containing the carbonized board using the vacuum pressure difference. Then, the pressure is increased to 2–4 MPa, maintained for 2–4 h, and the excess asphalt is returned. In this invention, the temperature of the liquid-phase impregnation is controlled at 160–210°C, which reduces the viscosity of the asphalt.

[0074] In this invention, the liquid phase impregnation process preferably includes cooling to ≤90°C, more preferably cooling to ≤80°C, and further cooling to ≤60°C; this invention hardens asphalt through cooling; this invention does not have any special limitations on the cooling process, and any cooling method known to those skilled in the art can be used, such as natural cooling.

[0075] In this invention, the second carbonization preferably includes sequential heating, holding, and cooling; the heating rate is preferably 10–100°C / h, more preferably 20–80°C / h, and even more preferably 40–50°C / h; the final heating temperature is the same as the holding temperature. In this invention, the holding temperature is preferably 950–1100°C, more preferably 980–1080°C, and even more preferably 1000–1050°C; the holding time is preferably 1–3 h, more preferably 1.5–2.5 h, and even more preferably 2 h; during the second carbonization process, asphalt is converted into asphalt carbon, which is more easily graphitized than resin carbon. In this invention, the cooling rate is preferably 50–100°C / h, more preferably 60–90°C / h, and even more preferably 70–80°C / h.

[0076] In this invention, the number of times the second carbonization after liquid phase impregnation (i.e., liquid phase impregnation-second carbonization) is performed is preferably 1 to 4 times, more preferably 2 to 4 times, and even more preferably 3 times. In this invention, after one liquid phase impregnation-second carbonization, the density of the liquid phase impregnated carbonized sheet is <1.5 g / cm³. 3 In this process, it is preferable to repeat the liquid-phase impregnation-second carbonization process. In this invention, the density of the liquid-phase impregnated carbonized sheet is preferably ≥1.5 g / cm³. 3 More preferably, it is 1.5–1.7 g / cm³. 3 .

[0077] In this invention, the second carbonization process preferably includes cooling to ≤100°C, more preferably cooling to ≤90°C, and further cooling to ≤60°C. This invention does not have any special limitations on the cooling process, and any cooling method known to those skilled in the art can be used, such as natural cooling. In this invention, it is preferred to test the density of the liquid phase impregnated carbonized plate after cooling is completed.

[0078] After obtaining the liquid-phase impregnated carbonized board, the present invention performs graphitization treatment on the liquid-phase impregnated carbonized board to obtain a carbon-carbon composite material. In the present invention, the temperature of the graphitization treatment is preferably 1800-2300℃, more preferably 1900-2200℃, and even more preferably 2000-2100℃; the time of the graphitization treatment is preferably 2-4 hours, more preferably 2.5-3.5 hours, and even more preferably 3 hours. In the present invention, during the graphitization treatment, polynitrosilane is converted into silicon nitride. Graphitization treatment can improve the graphitization degree of the board, reduce its internal ash content, and improve the strength of the board.

[0079] In this invention, the graphitization process preferably includes cooling to room temperature; the present invention does not have any particular limitation on the cooling, and any cooling method known to those skilled in the art can be used, such as natural cooling.

[0080] The present invention provides a carbon-carbon composite material prepared by the preparation method described in the above technical solution.

[0081] This invention provides the application of the carbon-carbon composite material described in the above technical solution in plasma-enhanced chemical vapor deposition.

[0082] This invention provides a carbon-carbon composite PECVD support frame, which is obtained by machining the carbon-carbon composite material described in the above-mentioned technical solution. In this invention, the machining preferably includes: sequentially grinding, trimming, and milling the carbon-carbon composite material. In this invention, the carbon-carbon composite PECVD support frame is preferably designed according to the final structure of the support frame.

[0083] In this invention, the carbon-carbon composite PECVD support frame is preferably a flat plate frame grid structure. The grid arrangement within the carbon-carbon composite PECVD support frame is preferably (4-5)×(4-8), specifically 4×4, 5×4, 4×5, 5×5, 4×6, 5×6, 4×7, 5×7, 4×8, or 5×8. In this invention, the thickness of the carbon-carbon composite PECVD support frame is preferably 3-20 mm, more preferably 5-15 mm.

[0084] To further illustrate the present invention, the carbon-carbon composite material, its preparation method and application, and the carbon-carbon composite PECVD support frame are described in detail below with reference to the accompanying drawings and embodiments. However, these descriptions should not be construed as limiting the scope of protection of the present invention.

[0085] Example 1

[0086] Step 1: Resin Solution Preparation

[0087] Phenolic resin (Y6412 from Guangming Resin Factory) and ethanol (purity above 95%) were mechanically mixed at a mass ratio of 100:10 at 25°C to obtain a resin solution with a viscosity of 3000 Pa·s.

[0088] Step 2: Resin Impregnation

[0089] Carbon fiber cloth is impregnated with a resin solution using a resin impregnation device (including a feeding device, an impregnation device, a coating device, a drying device, a cooling device, and a winding device) to obtain a prepreg. The carbon fiber cloth has a basis weight of 320 g / m². 2 Plain weave, carbon fiber specification is 48K; the resin content in the prepreg is 35wt%.

[0090] Step 3: Fabric cutting and layering

[0091] The prepreg is cut to the required dimensions using a CNC automatic fabric cutting machine. The cut dimensions and quantities match the design requirements, with a certain allowance reserved for subsequent CNC machining. The automatic fabric cutting machine has an efficiency of 1700 mm / s, a cutting dimensional error of ±1 mm, and a single-layer thickness of 0.4–0.5 mm for the prepreg.

[0092] The prepreg and polynitrosilane were weighed together at a mass ratio of 100:3 to obtain a polynitrosilane solution, wherein the solvent was styrene, the number average molecular weight of the polynitrosilane was 8000-15000, and the concentration of the polynitrosilane solution was 80 wt%.

[0093] Using a flat steel plate coated with release agent as the support mold, the cut prepreg is evenly and flatly laid on the steel plate. Each layer is smoothed with a plastic scraper, and polynitrosilane solution is sprayed onto the surface of the prepreg using a spraying device. Then, the layers are laid one by one according to the required thickness (total thickness is 3-20mm). After all the layers are laid, another steel plate coated with release agent is placed on the top surface, and then the subsequent molding is carried out.

[0094] Step 4: Molding

[0095] The molding process is shown in Table 1 below, which yields the resin-impregnated molded plate.

[0096] Table 1 Molding Process

[0097] Phase number Stage time / min Temperature change time / s Set temperature / °C Set pressure / MPa Temperature and pressure changes 1 70 4200 110 0.00 Heating and pressure holding 2 30 0 110 0.00 Insulation and pressure maintenance 3 2 0 110 0.10 Insulation and pressurization 4 2 0 110 0.30 Insulation and pressurization 5 2 0 110 0.50 Insulation and pressurization 6 2 0 110 0.80 Insulation and pressurization 7 3 0 110 0.80 Insulation and pressure maintenance 8 50 3000 150 0.80 Heating and pressure holding 9 30 0 150 0.80 Insulation and pressure maintenance 10 60 3600 180 0.80 Heating and pressure holding 11 85 0 180 0.80 Insulation and pressure maintenance

[0098] Step 5: First carbonization

[0099] The impregnated molded plate is subjected to a first carbonization process to obtain a carbonized sheet. The specific first carbonization process is shown in Table 2.

[0100] Table 2 First Carbonization Process Conditions

[0101]

[0102]

[0103] Step 6: Liquid phase impregnation - second carbonization

[0104] Carbonized boards are placed in a vacuum pressure impregnation furnace. The furnace is heated to 180°C to reduce the viscosity of the asphalt (grade PE180) to 40,000 Pa·s. The asphalt is then drawn into the furnace using the vacuum pressure difference to impregnate the carbonized boards in the liquid phase. The pressure is increased to 3 MPa and maintained for 3 hours. Excess asphalt is then returned out and cooled to below 90°C in the furnace to harden the asphalt, thus obtaining liquid-impregnated boards.

[0105] The liquid-phase impregnated plate was then removed and placed in a carbonization furnace for a second carbonization. The furnace was cooled to below 100°C, and the density of the resulting plate was determined to be 1.22 g / cm³ using the water displacement method. 3 The concentration did not reach 1.5 g / cm³. 3 After repeating the liquid phase impregnation-second carbonization-furnace cooling steps once, the density of the plate was determined to be 1.31 g / cm³ by the water displacement method. 3 After repeating the liquid phase impregnation-second carbonization-furnace cooling steps twice, the density of the plate was determined to be 1.42 g / cm³ by the water displacement method. 3 After repeating the liquid phase impregnation-second carbonization-furnace cooling steps three times, the density of the plate was determined to be 1.51 g / cm³ by the water displacement method. 3 Liquid-phase impregnation carbonized substrates were obtained (repeated 3 times). The second carbonization process conditions were as follows: heating to 1000℃ at a rate of 50℃ / h, holding at that temperature for 2 hours, and then cooling to below 90℃ at a rate of 50℃ / h. Step 7: High-temperature graphitization treatment.

[0106] A carbon-carbon composite material was obtained by adding graphite fixtures to a liquid-phase impregnated carbonized plate and then subjecting it to high-temperature graphitization treatment at 1800℃ for 3 hours. The density of the carbon-carbon composite material was determined to be 1.55 g / cm³ by the water displacement method. 3 .

[0107] Process 8: Precision machining

[0108] The carbon-carbon composite material was sequentially ground, trimmed, and milled according to the final structural design of the load-bearing frame to obtain a flat frame-type grid structure carbon-carbon composite PECVD load-bearing frame, such as... Figure 2 As shown, its grid arrangement is 5×8, belonging to the 5×8-210 series, and can support a total of 40 silicon wafers.

[0109] Example 2

[0110] Step 1: Resin Solution Preparation

[0111] Phenolic resin (EXP-0026E from Shandong Leling Yushi) and ethanol (purity above 95%) were mechanically mixed at a mass ratio of 100:15 at 30°C to obtain a resin solution with a viscosity of 2000 Pa·s.

[0112] Step 2: Resin Impregnation

[0113] Carbon fiber cloth is impregnated with a resin solution using a resin impregnation device (including a feeding device, an impregnation device, a coating device, a drying device, a cooling device, and a winding device) to obtain a prepreg. The carbon fiber cloth has a basis weight of 410 g / m². 2 Plain weave, carbon fiber specification is 48K; the resin content in the prepreg is 38wt%.

[0114] Step 3: Fabric cutting and layering

[0115] The prepreg is cut to the required dimensions using a CNC automatic fabric cutting machine. The cut dimensions and quantities match the design requirements, with a certain allowance reserved for subsequent CNC machining. The automatic fabric cutting machine has an efficiency of 1700 mm / s, a cutting dimensional error of ±1 mm, and a single-layer thickness of 0.4–0.5 mm for the prepreg.

[0116] The prepreg and polynitrosilane were weighed together at a mass ratio of 100:5 to obtain a polynitrosilane solution, wherein the solvent was styrene, the number average molecular weight of the polynitrosilane was 8000-15000, and the concentration of the polynitrosilane solution was 80 wt%.

[0117] Using a flat steel plate coated with release agent as the support mold, the cut prepreg is evenly and flatly laid on the steel plate. Each layer is smoothed with a plastic scraper, and polynitrosilane solution is sprayed onto the surface of the prepreg using a spraying device. Then, the layers are laid one by one according to the required thickness (total thickness is 3-20mm). After all the layers are laid, another steel plate coated with release agent is placed on the top surface, and then the subsequent molding is carried out.

[0118] Step 4: Molding

[0119] The molding process is shown in Table 1 below, which yields the resin-impregnated molded plate.

[0120] Step 5: First carbonization

[0121] The impregnated molded plate is subjected to a first carbonization process to obtain a carbonized sheet. The specific first carbonization process is shown in Table 3.

[0122] Table 3 First Carbonization Process Conditions

[0123]

[0124]

[0125] Step 6: Liquid phase impregnation - second carbonization

[0126] The carbonized board is placed in a vacuum pressure impregnation furnace, which is heated to 185°C to reduce the viscosity of the asphalt (grade PE180) to 40000 Pa·s. The vacuum pressure difference is used to draw all the asphalt into the furnace to impregnate the carbonized board in the liquid phase. The pressure is increased to 2.5 MPa and held for 3 hours. The excess asphalt is then returned and cooled to below 90°C in the furnace to harden the asphalt, thus obtaining the liquid-phase impregnated board.

[0127] The liquid-phase impregnated plate was then removed and placed in a carbonization furnace for a second carbonization. The furnace was cooled to below 100°C, and the density of the resulting plate was determined to be 1.32 g / cm³ using the water displacement method. 3 The concentration did not reach 1.5 g / cm³. 3 After repeating the above liquid phase impregnation-second carbonization-furnace cooling steps once, the density of the plate was determined to be 1.42 g / cm³ by the water displacement method. 3 After repeating the liquid phase impregnation-second carbonization-furnace cooling steps twice, the density of the plate was determined to be 1.50 g / cm³ by the water displacement method. 3 The liquid-phase impregnated carbonized board was obtained (repeated twice). The process conditions for the second carbonization were as follows: the temperature was increased to 1000℃ at a heating rate of 50℃ / h, held for 2h, and then cooled to below 90℃ at a cooling rate of 50℃ / h.

[0128] Step 7: High-temperature graphitization treatment

[0129] A carbon-carbon composite material was obtained by adding graphite fixtures to a liquid-phase impregnated carbonized plate and then performing high-temperature graphitization treatment at 1800℃ for 3.5 hours. The density of the carbon-carbon composite material was determined to be 1.54 g / cm³ by the water displacement method. 3 .

[0130] Process 8: Precision machining

[0131] The carbon-carbon composite material was sequentially ground, trimmed, and milled according to the final structural design of the load-bearing frame to obtain a flat frame-type grid structure carbon-carbon composite PECVD load-bearing frame, such as... Figure 2 As shown, its grid arrangement is 5×8, belonging to the 5×8-210 series, and can support a total of 40 silicon wafers.

[0132] Comparative Example 1

[0133] The carbon-carbon support frame prepared in Example 3 of Chinese Patent CN112430116A.

[0134] Comparative Example 2

[0135] The traditional graphite support frame disclosed in Chinese patent CN202758857U.

[0136] Test Example 1

[0137] The load-bearing frames prepared in Examples 1-2 and Comparative Examples 1-2 were subjected to performance tests. The bulk density was tested using the drainage method; tensile strength was tested using GB / T 33501-2017; flexural strength and flexural modulus were tested using GB / T 1449-2005; coefficient of thermal expansion was tested using GB / T 4722-2017; thermal conductivity was tested using GJB1201.1-91; and resistivity was tested using the four-probe method. The test results are shown in Table 4.

[0138] Table 4. Performance test results of the carrier frames prepared in Examples 1-2 and Comparative Examples 1-2

[0139]

[0140] As shown in Table 4, the carbon-carbon composite PECVD support frame prepared by the present invention has high strength and excellent mechanical properties. It can adapt to the complex process environment of PECVD, is not easily damaged, has a low replacement frequency, and a long service life. This indicates that the carbon-carbon composite PECVD support frame prepared by the preparation method provided by the present invention has better overall performance than the existing graphite support frame.

[0141] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, not all embodiments. People can obtain other embodiments based on the present invention without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for producing a carbon-carbon composite material, characterized by comprising the steps of: 2 1) mixing a carbon fiber and a carbon powder to prepare a mixture; 2) molding the mixture into a predetermined shape;​ arranging carbon in a resin solution for impregnation to obtain a prepreg; coating a polyazidosilane solution onto the surface of the prepreg to obtain a polyazidosilane prepreg, laying up several layers of the polyazidosilane prepreg to obtain a laminated polyazidosilane prepreg, and molding the laminated polyazidosilane prepreg to obtain a resin-impregnated molded plate; the number average molecular weight of the polyazidosilane is 8000-15000; and the mass ratio of the prepreg to the polyazidosilane is 100:3-5; first carbonizing the resin-impregnated molded plate to obtain a carbonized plate; The carbonized plate is placed in pitch for liquid-phase impregnation and then carbonized for the second time to obtain a liquid-phase impregnated carbonized plate; the density of the liquid-phase impregnated carbonized plate is ≥1.5 g / cm 3 ; graphitizing the liquid-phase impregnated carbonized plate to obtain a carbon-carbon composite material.

2. The production method according to claim 1, characterized by, The parameters of the carbon cloth include: the gram weight is 300-420 g / m 2 , the grain is plain or twill, and the carbon wire specification is 12-48K; The resin solution comprises resin and a solvent; the resin comprises one or more of phenolic resin, furan resin and benzoxazine resin; the solvent comprises ethanol; and the mass ratio of the resin to the solvent is 100:10-20; The content of the resin in the prepreg is 30-45wt%.

3. The method of claim 1, wherein, The polyazidosilane solution comprises polyazidosilane and a solvent; the solvent comprises styrene; and the concentration of the polyazidosilane solution is 70-85wt%. The single-layer thickness of the polyazidosilane prepreg is 0.4-0.5mm; The thickness of the laminated polyazidosilane prepreg is 3-20mm; The molding is segmented molding, which comprises sequentially performing first temperature rising molding, first temperature holding molding, second temperature rising molding, second temperature holding molding, third temperature rising molding and third temperature holding molding; The temperature rising rate of the first temperature rising molding is 1.2-1.3℃ / min, and the pressure is 0MPa; The temperature of the first temperature holding molding is 110℃, and the first temperature holding molding comprises sequentially performing first pressure holding, pressure rising and second pressure holding; the pressure of the first pressure holding is 0MPa, and the time is 30min; the pressure rising is rising by 0.2-0.3MPa at intervals of 2min, and the final pressure after the pressure rising is 0.8MPa; the pressure of the second pressure holding is 0.8MPa, and the time is 3min; The temperature rising rate of the second temperature rising molding is 0.8℃ / min, and the pressure is 0.8MPa; The temperature of the second temperature holding molding is 150℃, the time is 30min, and the pressure is 0.8MPa; The temperature rising rate of the third temperature rising molding is 0.5℃ / min, and the pressure is 0.8MPa; The temperature of the third temperature holding molding is 180℃, the time is 85min, and the pressure is 0.8MPa.

4. The production method according to claim 1, characterized by, The first carbonization is placing the resin-impregnated molded plate between two graphite plate toolings for first carbonization; The first carbonization comprises sequentially performing first temperature rising carbonization, first temperature holding carbonization, second temperature rising carbonization, second temperature holding carbonization, third temperature rising carbonization and third temperature holding carbonization; The time of the first temperature rising carbonization is 3-4h; The temperature of the first temperature holding carbonization is 190-210℃, and the holding time is 2-3h; The time of the second temperature rising carbonization is 13-15h; The temperature of the second temperature holding carbonization is 600-610℃, and the holding time is 2-3h; The time of the third temperature rising carbonization is 4-5h; The third carbonization temperature is 800-810℃, and the holding time is 2-3h.

5. The preparation method according to claim 1, characterized in that, The process conditions of the liquid phase impregnation include: temperature 160-210℃, pressure 2-4MPa, time 2-4h, and the equipment is a vacuum pressure impregnation furnace; The liquid phase impregnation is further followed by cooling to ≤90℃; The second carbonization after the liquid phase impregnation is performed 1-4 times; The second carbonization includes sequentially performing heating, holding and cooling; the heating rate is 10-100℃ / h; the holding temperature is 950-1100℃, and the holding time is 1-3h; and the cooling rate is 50-100℃ / h.

6. The method of claim 1, wherein, The graphitization temperature is 1800-2300℃, and the time is 2-4h.

7. The carbon-carbon composite material prepared by the preparation method of any one of claims 1-6.

8. The use of the carbon-carbon composite material of claim 7 in plasma enhanced chemical vapor deposition.

9. A carbon-carbon composite material PECVD bearing frame, which is machined from the carbon-carbon composite material of claim 7.

10. The carbon-carbon composite PECVD support frame of claim 9, wherein, The carbon-carbon composite material PECVD bearing frame is a flat frame grid structure, and the arrangement of the grids in the carbon-carbon composite material PECVD bearing frame is (4-5)×(4-8), and the thickness is 3-20mm.

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