High-temperature-resistant copper-clad plate based on modified bismaleimide resin and preparation method thereof

Abstract

The application relates to a preparation technology of a high-temperature-resistant material for a copper-clad plate, in particular to a high-temperature-resistant copper-clad plate based on a modified bismaleimide resin and a preparation method, wherein bismaleimide, self-prepared benzo-oxazine (BA-Ph) containing a cyano group, hyperbranched polysiloxane and a solvent are added into a same reaction bottle to react to obtain a glue solution, the glue solution is applied on a glass fiber cloth, the glass fiber cloth soaked with the glue solution is low-temperature dried and then is placed into a hot press, and the material for the copper-clad plate is obtained after multiple times of heating and pressing. The modified bismaleimide resin obtained by using the preparation method has excellent mechanical properties and heat resistance, the dielectric constant and dielectric loss are reduced, and the adhesion to fibers is improved, so that the use requirement of the resin matrix of the high-performance copper-clad plate is met.

Description

Technical Field

[0001] The present invention relates to a preparation technology of a material for a high-temperature resistant copper-clad laminate, and in particular to a high-temperature resistant copper-clad laminate based on a modified bismaleimide resin and a preparation method thereof. Background Art

[0002] Printed circuit boards (PCBs) play a key role in connecting and supporting electronic devices. With the rapid development of 5G technology, the performance requirements for PCB substrate materials are increasing. Within the electrical and electronic fields, PCB substrate materials have a wide range of applications. Copper-clad laminates (CCLs), the mainstream base material for PCB manufacturing, are primarily composed of three materials: resin, copper foil, and fiberglass cloth. The overall performance of CCLs depends largely on the properties of their resin matrix. Currently, the most commonly used matrix resins for substrate materials include epoxy resins and phenolic resins. However, these resin materials are primarily suitable for the production of standard circuit boards. With the rapid advancement of electronic information technology, electronic products are further developing towards miniaturization, lightweighting, and high-density assembly. Their high dielectric constant and insufficient heat resistance restrict their application.

[0003] In recent years, bismaleimide resin (BMI) has become an ideal resin for copper-clad laminate resin matrix due to its excellent heat resistance, dielectric properties, outstanding weather resistance, and chemical resistance. However, its shortcomings, such as mechanical properties, molding process, dielectric properties, and poor adhesion to fibers, have limited its direct application. Therefore, it is very necessary to modify bismaleimide resin. Developing high-performance resins with excellent comprehensive properties through modification is of great significance for expanding its application in the field of copper-clad laminates. Summary of the Invention

[0004] BMI has disadvantages such as high molding temperature and high brittleness of the cured product. Among them, high brittleness is the key obstacle to the development and application of BMI. At the same time, the dielectric properties and adhesion of BMI to fibers also need to be further improved.

[0005] In order to solve the above technical problems, the specific technical solutions of the high temperature resistant copper clad laminate based on modified bismaleimide resin and the preparation method of the present invention are as follows:

[0006] 1. A method for preparing a high-temperature resistant copper-clad laminate based on a modified bismaleimide resin, comprising the following steps:

[0007] Step 1: Add three solids, namely bismaleimide, cyano-containing benzoxazine BA-Ph, and hyperbranched polysiloxane, and a solvent into a reaction flask, heat to a set temperature, and stir until the solution is uniform and transparent; the mass ratio of the total mass of the three solids to the solvent liquid is 15-70%, the amount of BA-Ph is 5-40% of the mass of bismaleimide, and the amount of hyperbranched polysiloxane is 5-20% of the mass of bismaleimide; the solvent includes one or more of N,N-dimethylformamide, N-methylpyrrolidone, dimethyl sulfoxide, N,N-dimethylacetamide, and dioxane, and the bismaleimide includes N,N"-(4,4"-methylenediphenyl)bismaleimide (BDM), BMI-70, and BMI-80.

[0008] Step 2: reacting the transparent solution obtained in step 1 at 120°C for 3 hours to obtain a glue solution;

[0009] Step 3: Apply the glue prepared in step 2 evenly on the glass fiber cloth, and hang the fiber cloth to drip out the excess glue;

[0010] Step 4: Repeat the process of step 3 to obtain 8 pieces of glass fiber cloth soaked with glue;

[0011] Step 5: Place the eight pieces of glass fiber cloth soaked with glue obtained in step 4 into an oven to dry the solvent at a set temperature to obtain eight pieces of prepreg;

[0012] Step 6: Stack the prepregs obtained in step 5 neatly together, place them in the middle of the mold, and put the whole into the hot press. When the viscosity of the glue is close to the gel state, increase the temperature in stages 4 times, and maintain the pressure for the same period of time under the same pressure. The hot pressing temperature is 200-300℃, and the hot pressing pressure is 0-20MPa. After curing is completed and naturally cooled to room temperature, remove the mold to obtain the material used for the copper clad laminate.

[0013] Furthermore, the set temperature in step 1 and step 5 is 80°C.

[0014] Furthermore, the stage heating in step 6 is specifically 4 times: first 200°C, 5MPa, and pressure holding for 2h; then heating to 220°C, 5MPa, and pressure holding for 2h; 240°C, 5MPa, and pressure holding for 2h; and finally heating to 260°C, 5MPa, and pressure holding for 2h.

[0015] Furthermore, the preparation method of the cyano-containing benzoxazine is as follows: 1 mol of bisphenol A, 2 mol of paraformaldehyde, and 2 mol of 4-(4-aminophenoxy)phthalonitrile (3 solids) and a solvent are sequentially added to a container and mixed uniformly. The mixture is heated to 85° C. and reacted for 4 hours to obtain a product as a uniform brown viscous liquid with no solid deposits at the bottom of the container. After the reaction is completed, the mixture is poured into water for precipitation, and then washed three times with a 1N NaOH aqueous solution and water, respectively, to obtain the target product. The solvent is one or two of DMF, toluene, dioxane, xylene, and chloroform, and the solid-to-liquid mass ratio is 20-70%.

[0016] Furthermore, the hyperbranched polysiloxane is prepared by the following steps:

[0017] Step A1: 15 mmol of ethyl orthosilicate, 0.1 mol of trimethyloxyphenylsilane, and 8 mmol of 3-aminopropylmethyldiethoxysilane were added to a container containing tetrahydrofuran, and the reaction mixture was cooled to 0°C in an ice bath;

[0018] Step A2: Add deionized water dropwise under vigorous stirring for 1 hour;

[0019] Step A3: The reaction mixture was stirred at 0°C for 1 hour and then at 50°C for another 2 hours;

[0020] Step A4: After rotary evaporation under reduced pressure at 55 degrees Celsius for 5-8 hours, a white powder product was obtained;

[0021] Step A5: Collect the crude product, dissolve it in CH2Cl2, and then add cold ethanol to precipitate; repeat this process at least 3 times;

[0022] Step A6: The resulting product was collected by suction filtration, volatiles were removed, and dried in a vacuum oven at room temperature for at least 48 hours to obtain a white powder product.

[0023] Compared with the existing bismaleimide resin, the present invention has the following technical effects:

[0024] 1. Increase the glass transition temperature of the resin through simple blending and copolymerization reaction.

[0025] 2. The branched structure of hyperbranched polysiloxane can improve the brittleness of bismaleimide resin. The introduction of hyperbranched structure into bismaleimide resin can significantly improve the fracture toughness of the resin without affecting its heat resistance.

[0026] 3. The amino groups in hyperbranched polysiloxane can promote the ring-opening polymerization of benzoxazine rings and the curing polymerization of cyano groups. They can also react with bismaleimide resins. The copper-clad laminates prepared based on modified bismaleimide resins have excellent comprehensive performance.

[0027] In summary, the preparation method provided by the present invention is simple in process and easy to scale up. The specific technical effects obtained are described in conjunction with the specific steps in the examples. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Schematic diagram of the synthesis process of benzoxazine containing cyano group (BA-Ph);

[0029] Figure 2 A schematic diagram of the preparation process provided by an embodiment of the present invention;

[0030] Figure 3 The molecular structure of BMI-70;

[0031] Figure 4 The molecular structure of BMI-80; DETAILED DESCRIPTION

[0032] In order to better understand the purpose, structure and function of the present invention, the following is a further detailed description of a high-temperature resistant copper-clad laminate based on a modified bismaleimide resin and a preparation method of the present invention in conjunction with the accompanying drawings.

[0033] The present invention provides a simple method for preparing a high-temperature-resistant, low-expansion copper-clad laminate based on a modified bismaleimide resin. The modified bismaleimide resin obtained by the preparation method has excellent mechanical properties and heat resistance, reduced dielectric constant and dielectric loss, and improved adhesion to fibers, thereby meeting the use requirements of the resin matrix of high-performance copper-clad laminates.

[0034] Preparation method of high temperature resistant copper clad laminate based on modified bismaleimide resin Figure 2 As shown, the following steps are included:

[0035] Step 1: Add bismaleimide, a homemade cyano-containing benzoxazine (BA-Ph), a hyperbranched polysiloxane, and a solvent, N,N-dimethylformamide (DMF), to a three-necked flask equipped with a condenser and a stirrer. The temperature is raised to 80°C and stirred until the solution becomes homogeneous and transparent. Specifically, the solvent may include one or more of N-methylpyrrolidone, dimethyl sulfoxide, N,N-dimethylacetamide, and dioxane. The amount of BA-Ph is 5-40% by weight of the bismaleimide, and the amount of the hyperbranched polysiloxane is 5-20% by weight of the bismaleimide. The total weight of the three solids to the weight of the solvent liquid is 15-70%.

[0036] Step 2: The transparent solution obtained in step 1 was reacted at 120° C. for 3 h to obtain a glue solution.

[0037] Step 3: Evenly apply the adhesive prepared in Step 2 to a 10cm x 10cm glass fiber cloth. Hang the cloth to allow excess adhesive to drip out. The mass ratio of adhesive to glass fiber cloth is 40:60. This surface coating treatment improves the bonding strength between the base material and the reinforcing fibers.

[0038] Step 4: Repeat the process of step 3 to obtain 8 pieces of glass fiber cloth soaked with glue.

[0039] Step 5: Place the eight pieces of glass fiber cloth soaked with glue obtained in step 4 into an oven, set the temperature to 80°C, and dry the solvent at a low temperature to obtain eight prepregs.

[0040] Step 6: Neatly stack the prepreg obtained in Step 5, sandwich it between two aluminum sheets, and then place it between two iron plates. The entire thing is placed in a hot press. When the viscosity of the adhesive approaches a gel state, heat it at 200°C, 5MPa, and hold the pressure for 2 hours. Then heat it to 220°C, 5MPa, and hold the pressure for 2 hours. Then heat it to 240°C, 5MPa, and hold the pressure for 2 hours. Finally, heat it to 260°C, 5MPa, and hold the pressure for 2 hours. After curing is complete and the material is naturally cooled to room temperature, remove the mold to obtain the material used for the copper clad laminate.

[0041] The resin matrix used in this copper clad laminate is made through a one-time hot pressing process, which simplifies the processing process. The resin matrix exhibits advantages such as excellent high temperature resistance, low dielectric constant, and high mechanical strength and modulus.

[0042] Further, the synthesis process of benzoxazine containing cyano group (BA-Ph) is as follows Figure 1 As shown, a one-pot method was used to synthesize a benzoxazine-containing phthalonitrile resin. Specifically, in this example, 22.83g of bisphenol A, 47.05g of 4-(4-aminophenoxy)phthalonitrile (4-APN), and 6.00g of paraformaldehyde were added to a three-necked flask in the following order, mixed evenly, and then heated to 85°C for 4 hours to produce a uniform, tan, viscous liquid with no solid deposits at the bottom of the flask. After the reaction, the mixture was poured into water for precipitation, and then washed three times with a 1N NaOH solution and then with water, yielding BA-Ph.

[0043] The introduction of cyano-containing benzoxazine resins can enhance the degree of cross-linking, thereby improving the material's heat resistance. Furthermore, the hydroxyl and cyano groups in the ring-opened benzoxazine act as polar groups, effectively improving its adhesion to fibers.

[0044] Furthermore, a hyperbranched polysiloxane was prepared by the following steps: 15 mmol (3.1250 g) of tetraethyl orthosilicate (TEOS), 0.1 mol (19.8290 g) of trimethyloxyphenylsilane (PTMS), and 8 mmol (1.5308 g) of 3-aminopropylmethyldiethoxysilane (APDES) were added to a 100 mL round-bottom flask containing 30 g of THF (tetrahydrofuran). The reaction mixture was cooled to 0°C in an ice bath, and 5.64 g of deionized water was added dropwise via syringe with vigorous stirring over 1 hour. The reaction mixture was stirred at 0°C for 1 hour and then at 50°C for an additional 2 hours. The crude product was obtained by rotary evaporation under reduced pressure to obtain a white powder. The crude product was collected, dissolved in dichloromethane (60 mL), and then precipitated by adding cold ethanol (200 mL). The typical dissolution-precipitation process was repeated at least three times, and the product was finally collected by filtration, volatiles were removed, and dried in a vacuum oven at room temperature for at least 48 hours to obtain a white powder product.

[0045] The amino groups in hyperbranched polysiloxanes can promote the ring-opening polymerization of benzoxazine rings and the curing polymerization of cyano groups. They can also react with bismaleimide resins. The branched structure of hyperbranched polysiloxanes can improve the resin's brittleness. Introducing hyperbranched structures into bismaleimide resins can significantly improve the resin's fracture toughness without affecting its glass transition temperature.

[0046] Example 1

[0047] This embodiment provides a method for preparing a high-temperature resistant copper-clad laminate based on a modified bismaleimide resin, comprising the following steps:

[0048] Step 1: 30 g BDM, 3 g BA-Ph, 1.5 g hyperbranched polysiloxane, and 31.8 g N,N-dimethylformamide were added sequentially into a three-necked flask equipped with a stirring rod and a condenser, and dissolved in an 80°C oil bath until a clear solution was obtained;

[0049] Step 2: The transparent solution obtained in step 1 was reacted at 120° C. for 3 h to obtain a glue solution.

[0050] Step 3: Combine 32g of the adhesive prepared in Step 2 with 8 sheets of fiberglass cloth (24g each), with the mass ratio of adhesive to fiberglass cloth being 40:60. Apply the adhesive evenly to each 10cm*10cm sheet of fiberglass cloth, and hang the cloth to allow excess adhesive to drip out.

[0051] Step 4: Place the eight pieces of glass fiber cloth soaked with glue obtained in step 3 into a programmed oven at 80°C to process the solvent to obtain eight prepregs.

[0052] Step 5: Stack the prepreg obtained in Step 4 neatly, sandwich it between two aluminum sheets, and then place it between two iron plates. Place the entire thing in a hot press. When the viscosity of the adhesive approaches a gel state, heat it at 200°C, 5MPa, and hold the pressure for 2 hours. Then heat it to 220°C, 5MPa, and hold the pressure for 2 hours. Then heat it to 240°C, 5MPa, and hold the pressure for 2 hours. Finally, heat it to 260°C, 5MPa, and hold the pressure for 2 hours.

[0053] Step 6: After the solidification in step 5 is completed and naturally cooled to room temperature, the mold is removed to obtain the copper clad laminate material.

[0054] The surface of the copper clad laminate obtained after curing is smooth and has no defects such as bubbles; the bending strength is 520MPa, the bending modulus is 32.0GPa, and the thermal decomposition temperature (T 5％ ) is 377℃, and the glass transition temperature (T g ) is 273℃, the dielectric constant is 4.52 at 1MHz frequency under room temperature conditions, and the dielectric loss is 0.0143. All data meet the standard requirements of resin for copper clad laminates.

[0055] Example 2

[0056] Step 1: Add 30g BDM, 3g BA-Ph, 3g hyperbranched polysiloxane, and 31.8g N,N-dimethylformamide to a three-necked flask equipped with a stirring rod and a condenser. Dissolve in an 80°C oil bath until a clear solution is obtained.

[0057] Step 2: React the transparent solution in step 1 at 120°C for 3 hours to obtain a glue solution.

[0058] Step 3: Combine 32g of the adhesive prepared in Step 2 with 8 sheets of fiberglass cloth (24g each), with the mass ratio of adhesive to fiberglass cloth being 40:60. Apply the adhesive evenly to each 10cm*10cm sheet of fiberglass cloth, and hang the cloth to allow excess adhesive to drip out.

[0059] Step 4: Place the eight pieces of glass fiber cloth soaked with glue obtained in step 3 into a programmed oven to process the solvent to obtain eight prepregs.

[0060] Step 5: Stack the prepreg obtained in Step 4 neatly, sandwich it between two aluminum sheets, and then place it between two iron plates. Place the entire thing in a hot press. When the viscosity of the adhesive approaches a gel state, heat it at 200°C, 5MPa, and hold the pressure for 2 hours. Then heat it to 220°C, 5MPa, and hold the pressure for 2 hours. Then heat it to 240°C, 5MPa, and hold the pressure for 2 hours. Finally, heat it to 260°C, 5MPa, and hold the pressure for 2 hours.

[0061] Step 6: After the solidification in step 5 is completed and naturally cooled to room temperature, the mold is removed to obtain the copper clad laminate material.

[0062] The surface of the copper clad laminate obtained after curing is smooth and has no defects such as bubbles; the bending strength is 618MPa, the bending modulus is 34.8GPa, and the thermal decomposition temperature (T 5％ ) is 401℃, and the glass transition temperature (T g ) is 285℃, the dielectric constant is 4.38 at 1MHz frequency under room temperature conditions, and the dielectric loss is 0.0117. All data meet the standard requirements for resins for copper clad laminates.

[0063] Example 3

[0064] Step 1: Add 30g BDM, 6g BA-Ph, 3g hyperbranched polysiloxane, and 31.8g N,N-dimethylformamide to a three-necked flask equipped with a stirring rod and a condenser. Dissolve in an 80°C oil bath until a clear solution is obtained.

[0065] Step 2: React the transparent solution in step 1 at 120°C for 3 hours to obtain a glue solution.

[0066] Step 3: Combine 32g of the adhesive prepared in Step 2 with 8 sheets of fiberglass cloth (24g each), with the mass ratio of adhesive to fiberglass cloth being 40:60. Apply the adhesive evenly to each 10cm*10cm sheet of fiberglass cloth, and hang the cloth to allow excess adhesive to drip out.

[0067] Step 4: Place the eight pieces of glass fiber cloth soaked with glue obtained in step 3 into a programmed oven to process the solvent to obtain eight prepregs.

[0068] Step 5: Stack the prepreg obtained in Step 4 neatly, sandwich it between two aluminum sheets, and then place it between two iron plates. Place the entire thing in a hot press. When the viscosity of the adhesive approaches a gel state, heat it at 200°C, 5MPa, and hold the pressure for 2 hours. Then heat it to 220°C, 5MPa, and hold the pressure for 2 hours. Then heat it to 240°C, 5MPa, and hold the pressure for 2 hours. Finally, heat it to 260°C, 5MPa, and hold the pressure for 2 hours.

[0069] Step 6: After the solidification in step 5 is completed and naturally cooled to room temperature, the mold is removed to obtain the copper clad laminate material.

[0070] The surface of the copper clad laminate obtained after curing is smooth and has no defects such as bubbles; the bending strength is 656MPa, the bending modulus is 36.2GPa, and the thermal decomposition temperature (T 5％ ) is 415℃, and the glass transition temperature (T g ) is 302℃, the dielectric constant is 4.57 at 1MHz frequency under room temperature conditions, and the dielectric loss is 0.0135. All data meet the standard requirements for resins for copper clad laminates.

[0071] Example 4

[0072] Step 1: Add 30g BDM, 9g BA-Ph, 3g hyperbranched polysiloxane, and 31.8g N,N-dimethylformamide to a three-necked flask equipped with a stirring rod and condenser. Dissolve in an 80°C oil bath until a clear solution is obtained.

[0073] Step 2: React the transparent solution in step 1 at 120°C for 3 hours to obtain a glue solution.

[0074] Step 3: Combine 32g of the adhesive prepared in step 2 with 8 sheets of glass fiber cloth (24g). The mass ratio of the adhesive to the glass fiber cloth is 40:60. Apply the adhesive evenly to each 10cm*10cm sheet of glass fiber cloth, and hang the fiber cloth to drip out the excess adhesive.

[0075] Step 4: Place the eight pieces of glass fiber cloth soaked with glue obtained in step 3 into a programmed oven to process the solvent to obtain eight prepregs.

[0076] Step 5: Stack the prepreg obtained in Step 4 neatly, sandwich it between two aluminum sheets, and then place it between two iron plates. Place the entire thing in a hot press. When the viscosity of the adhesive approaches a gel state, heat it at 200°C, 5MPa, and hold the pressure for 2 hours. Then heat it to 220°C, 5MPa, and hold the pressure for 2 hours. Then heat it to 240°C, 5MPa, and hold the pressure for 2 hours. Finally, heat it to 260°C, 5MPa, and hold the pressure for 2 hours.

[0077] Step 6: After the solidification in step 5 is completed and naturally cooled to room temperature, the mold is removed to obtain the copper clad laminate material.

[0078] The surface of the copper clad laminate obtained after curing is smooth and has no defects such as bubbles; the bending strength is 582MPa, the bending modulus is 31.2GPa, and the thermal decomposition temperature (T 5％ ) is 438℃, and the glass transition temperature (T g ) is 328℃, the dielectric constant is 4.74 at 1MHz frequency under room temperature conditions, and the dielectric loss is 0.0156. All data meet the standard requirements for resins for copper clad laminates.

[0079] Example 5

[0080] Step 1: 30g BMI-70, 6g BA-Ph, 3g hyperbranched polysiloxane, and 31.8g N,N-dimethylformamide were added sequentially to a three-necked flask equipped with a stirring rod and a condenser. Dissolved in an oil bath at 80°C until a clear solution was obtained. The molecular structure of BMI-70 is as follows: Figure 3 As shown;

[0081] Step 2: React the transparent solution in step 1 at 120°C for 3 hours to obtain a glue solution.

[0082] Step 3: Combine 32g of the adhesive prepared in step 2 with 8 sheets of glass fiber cloth (24g). The mass ratio of the adhesive to the glass fiber cloth is 40:60. Apply the adhesive evenly to each 10cm*10cm sheet of glass fiber cloth, and hang the fiber cloth to drip out the excess adhesive.

[0083] Step 4: Place the eight pieces of glass fiber cloth soaked with glue obtained in step 3 into a programmed oven to process the solvent to obtain eight prepregs.

[0084] Step 5: Stack the prepreg obtained in Step 4 neatly, sandwich it between two aluminum sheets, and then place it between two iron plates. Place the entire thing in a hot press. When the viscosity of the adhesive approaches a gel state, heat it at 200°C, 5MPa, and hold the pressure for 2 hours. Then heat it to 220°C, 5MPa, and hold the pressure for 2 hours. Then heat it to 240°C, 5MPa, and hold the pressure for 2 hours. Finally, heat it to 260°C, 5MPa, and hold the pressure for 2 hours.

[0085] Step 6: After the solidification in step 5 is completed and naturally cooled to room temperature, the mold is removed to obtain the copper clad laminate material.

[0086] The surface of the copper clad laminate obtained after curing is smooth and has no defects such as bubbles; the bending strength is 635MPa, the bending modulus is 33.2GPa, and the thermal decomposition temperature (T 5％ ) is 388℃, and the glass transition temperature (T g ) is 296℃, the dielectric constant is 4.35 at 1MHz frequency under room temperature conditions, and the dielectric loss is 0.0106. All data meet the standard requirements for resins for copper clad laminates.

[0087] Example 6

[0088] Step 1: 30g BMI-80, 6g BA-Ph, 3g hyperbranched polysiloxane, and 31.8g N,N-dimethylformamide were added sequentially to a three-necked flask equipped with a stirring rod and a condenser. Dissolved in an oil bath at 80°C until a clear solution was obtained. The molecular structure of BMI-80 is as follows: Figure 4 As shown;

[0089] Step 2: React the transparent solution in step 1 at 120°C for 3 hours to obtain a glue solution.

[0090] Step 3: Combine 32g of the adhesive prepared in step 2 with 8 sheets of glass fiber cloth (24g). The mass ratio of the adhesive to the glass fiber cloth is 40:60. Apply the adhesive evenly to each 10cm*10cm sheet of glass fiber cloth, and hang the fiber cloth to drip out the excess adhesive.

[0091] Step 4: Place the eight pieces of glass fiber cloth soaked with glue obtained in step 3 into a programmed oven to process the solvent to obtain eight prepregs.

[0092] Step 5: Stack the prepreg obtained in Step 4 neatly, sandwich it between two aluminum sheets, and then place it between two iron plates. Place the entire thing in a hot press. When the viscosity of the adhesive approaches a gel state, heat it at 200°C, 5MPa, and hold the pressure for 2 hours. Then heat it to 220°C, 5MPa, and hold the pressure for 2 hours. Then heat it to 240°C, 5MPa, and hold the pressure for 2 hours. Finally, heat it to 260°C, 5MPa, and hold the pressure for 2 hours.

[0093] Step 6: After the solidification in step 5 is completed and naturally cooled to room temperature, the mold is removed to obtain the copper clad laminate material.

[0094] The surface of the copper clad laminate obtained after curing is smooth and has no defects such as bubbles; the bending strength is 670MPa, the bending modulus is 35.8GPa, and the thermal decomposition temperature (T 5％ ) is 427℃, and the glass transition temperature (T g ) is 308℃, the dielectric constant is 4.62 at 1MHz frequency under room temperature conditions, and the dielectric loss is 0.0124. All data meet the standard requirements of resin for copper clad laminates.

[0095] It will be understood that the present invention is described by way of some embodiments, and it will be appreciated by those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are intended to be protected by the present invention.

Claims

1. A method for preparing a high-temperature resistant copper-clad laminate based on a modified bismaleimide resin, characterized in that: The following steps are involved: Step 1: Add bismaleimide, cyano-containing benzoxazine BA-Ph, hyperbranched polysiloxane and solvent into a reaction flask, heat to the set temperature, and stir until the solution is uniform and transparent; Step 2: reacting the transparent solution obtained in step 1 at 120°C for 3 hours to obtain a glue solution; Step 3: Apply the glue prepared in step 2 evenly on the glass fiber cloth, and hang the fiber cloth to drip out the excess glue; Step 4: Repeat the process of step 3 to obtain 8 pieces of glass fiber cloth soaked with glue; Step 5: Place the eight pieces of glass fiber cloth soaked with glue obtained in step 4 into an oven to dry the solvent at a set temperature to obtain eight pieces of prepreg; Step 6: The prepregs obtained in step 5 are neatly stacked together, placed in the middle of the mold, and placed in a hot press as a whole. When the viscosity of the glue is close to the gel state, the temperature is increased in stages 4 times, and the pressure is maintained at the same pressure for the same period of time. The hot pressing temperature is 200-300°C and the hot pressing pressure is 0-20MPa. After curing is completed and naturally cooled to room temperature, the mold is removed to obtain the material used for the copper clad laminate. In step 1, the mass ratio of the total mass of the three solids to the solvent liquid is 15-70%, the amount of BA-Ph is 5-40% of the mass of bismaleimide, and the amount of hyperbranched polysiloxane is 5-20% of the mass of bismaleimide; The preparation method of the cyano-containing benzoxazine BA-Ph is as follows: 1 mol of bisphenol A, 2 mol of paraformaldehyde, and 2 mol of 4-(4-aminophenoxy)phthalonitrile (3 solids) and a solvent are sequentially added to a container and mixed evenly. The mixture is heated to 85° C. and heated for reaction for 4 hours to obtain a uniform brown viscous liquid product with no solid deposits at the bottom of the container. After the reaction, the product is poured into water for precipitation, and then washed three times with a 1N NaOH aqueous solution and water, respectively, to obtain the target product. The solvent is one or two of DMF, toluene, dioxane, xylene, and chloroform, wherein the solid-liquid mass ratio is 20-70%; The hyperbranched polysiloxane is prepared by the following steps: Step A1: 15 mmol of ethyl orthosilicate, 0.1 mol of trimethyloxyphenylsilane, and 8 mmol of 3-aminopropylmethyldiethoxysilane were added to a reaction flask containing tetrahydrofuran, and the reaction mixture was cooled to 0°C in an ice bath; Step A2: Add deionized water dropwise under vigorous stirring for 1 hour; Step A3: The reaction mixture was stirred at 0°C for 1 hour and then at 50°C for another 2 hours; Step A4: Rotary evaporation under reduced pressure can obtain a crude white powder product; Step A5: Collect the crude product, dissolve it in dichloromethane, and then add cold ethanol to precipitate; repeat this process at least 3 times; Step A6: The product was collected by filtration, volatiles were removed, and dried in a vacuum oven at room temperature for at least 48 hours to obtain a white powder product.

2. The method for preparing a high temperature resistant copper clad laminate based on modified bismaleimide resin according to claim 1, wherein The solvent in step 1 includes one or more of N,N-dimethylformamide, N-methylpyrrolidone, dimethyl sulfoxide, N,N-dimethylacetamide, and xylene.

3. The method for preparing a high temperature resistant copper clad laminate based on modified bismaleimide resin according to claim 2, wherein: The set temperature in the step 1 and the step 5 is 80°C.

4. The method for preparing a high temperature resistant copper clad laminate based on modified bismaleimide resin according to claim 3, wherein: The staged temperature increase in step 6 is specifically 4 times: first 200°C, 5MPa, and pressure holding for 2h; then heating to 220°C, 5MPa, and pressure holding for 2h; 240°C, 5MPa, and pressure holding for 2h; and finally heating to 260°C, 5MPa, and pressure holding for 2h.

5. A high temperature resistant copper clad laminate based on modified bismaleimide resin, characterized in that: The material used for the high-temperature resistant copper clad laminate is made based on the preparation method described in any one of claims 1-4.

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