A copper clad laminate that is not prone to leakage current tracking and its preparation process

Abstract

The present invention discloses a copper clad laminate that is not prone to leakage and tracking and its preparation process, relating to the technical field of copper clad laminates. When preparing the copper clad laminate that is not prone to leakage and tracking, silicon carbide whiskers are first reacted with tetraethyl orthosilicate and trimethoxysilane in sequence to obtain pre-modified silicon carbide whiskers, and the pre-modified silicon carbide whiskers are then reacted with triallylsilane and triethoxysilane in sequence to obtain modified silicon carbide whiskers; KBJS-600A70 resin, tetrafunctional epoxy resin, dicyandiamide, coupling agent, modified silicon carbide whiskers, and N,N-dimethylformamide are mixed to obtain a first-stage material; KBJS-600A70 resin, 2-methylimidazole, aluminum hydroxide, and ammonium persulfate are mixed to obtain a second-stage material. The first-stage material is stirred, sheared, and ground, and then the second-stage material is heated and stirred, sheared, and ground again to obtain a glue solution. The glass cloth is impregnated with the glue solution and then baked, and then laminated and pressed with copper foil to obtain a copper clad laminate that is not prone to leakage and tracking. The copper clad laminate prepared by the present invention has excellent peel resistance and is not prone to leakage and tracking.

Description

Technical Field

[0001] The present invention relates to the technical field of copper clad laminates, and specifically to a copper clad laminate that is not prone to leakage and tracking and its preparation process. Background Art

[0002] As the base material in the manufacture of printed circuit boards, the copper clad laminate mainly functions as interconnection conduction, insulation, and support for the printed circuit board, and has a great influence on the signal transmission speed, energy loss, characteristic impedance, etc. in the circuit. Therefore, the performance, quality, processability, manufacturing level, manufacturing cost, and long-term reliability and stability of the printed circuit board largely depend on the copper clad laminate.

[0003] Due to the miniaturization, lightweight, and thinness of electronic products, it is necessary for printed circuit boards to have various high-quality and high-tech characteristics, which directly involves a variety of contemporary high-techs in the manufacturing technology of printed circuit boards. As its main and most important material, the copper clad laminate must also possess various high-quality and high-tech characteristics accordingly. Therefore, the position of the copper clad laminate in the electronic information industry becomes increasingly important, and the performance requirements for the copper clad laminate are also getting higher and higher. Summary of the Invention

[0004] The purpose of the present invention is to provide a copper clad laminate that is not prone to leakage and tracking and its preparation process to solve the problems existing in the prior art.

[0005] To solve the above technical problems, the present invention provides the following technical solutions:

[0006] A copper clad laminate that is not prone to leakage and tracking is prepared by impregnating glass cloth with a glue solution and then baking to obtain a prepreg, and then laminating and pressing the prepreg and copper foil together.

[0007] As an optimization, the glue solution is prepared by stirring, shearing, and grinding a first-stage material, heating a second-stage material, and then stirring, shearing, and grinding again.

[0008] As an optimization, the first-stage material is prepared by mixing KBJS-600A70 resin, tetrafunctional epoxy resin, dicyandiamide, coupling agent, modified silicon carbide whiskers, and N,N-dimethylformamide; the second-stage material is prepared by mixing KBJS-600A70 resin, 2-methylimidazole, aluminum hydroxide, and ammonium persulfate; the modified silicon carbide whiskers are prepared by reacting silicon carbide whiskers with tetraethyl orthosilicate and trimethoxysilane in sequence to obtain pre-modified silicon carbide whiskers, and then reacting the pre-modified silicon carbide whiskers with triallylsilane and triethoxysilane in sequence.

[0009] As an optimization, the preparation process of the copper clad laminate that is not prone to leakage and tracking includes the following preparation steps:

[0010] (1) Preparation of modified silicon carbide whiskers: Mix silicon carbide whiskers and pure water evenly at a mass ratio of 1:50 - 1:60, stir at 10 - 30 °C and 200 - 300 r / min for 20 - 30 min. While keeping the stirring speed unchanged, add tetraethyl orthosilicate solution which is 15 - 20 times the mass of silicon carbide whiskers dropwise at a speed of 0.1 - 0.2 mL / s. After the titration, continue stirring for 20 - 30 min, perform ultrasonic treatment at 50 - 70 °C and 30 - 40 kHz for 6 - 8 h, filter and wash with pure water and absolute ethanol 3 - 5 times each, dry at 60 - 70 °C for 4 - 6 h, then mix evenly with trimethoxysilane, pure water and absolute ethanol at a mass ratio of 1:1:10:10 - 2:1:15:15, perform ultrasonic treatment at 50 - 60 °C and 30 - 40 kHz for 6 - 8 h, filter and wash with pure water and absolute ethanol 3 - 5 times each, dry at 90 - 100 °C for 4 - 6 h to obtain pre-modified silicon carbide whiskers; Mix the pre-modified silicon carbide whiskers, triallylsilane and n-hexane evenly at a mass ratio of 1:1:5 - 1:1:8, then add chloroplatinic acid which is 0.03 - 0.05 times the mass of triallylsilane, stir and reflux at 70 - 80 °C and 500 - 800 r / min for 4 - 6 h, then add triethoxysilane which is 3 - 4 times the mass of triallylsilane, continue stirring and refluxing for 4 - 6 h, and let it stand at 20 - 30 °C and 1 - 2 kPa for 3 - 4 h to obtain modified silicon carbide whiskers;

[0011] (2) Mixing, shearing and grinding: Mix KBJS-600A70 resin, tetrafunctional epoxy resin, dicyandiamide, coupling agent, modified silicon carbide whiskers and N,N-dimethylformamide evenly at a mass ratio of 20:1:3:0.05:11:12 - 25:1:4:0.07:13:14 to prepare the first-stage material; Mix KBJS-600A70 resin, 2-methylimidazole, aluminum hydroxide and ammonium persulfate evenly at a mass ratio of 11:0.01:3:0.4 - 13:0.01:4:0.6 to prepare the second-stage material; Stir the first-stage material at 30 - 40 °C and 1200 - 1600 r / min for 2 - 3 h, continue stirring and perform shearing and grinding in sequence, then add the second-stage material which is 0.9 - 1.1 times the mass of the first-stage material, stir at 30 - 40 °C and 1200 - 1600 r / min for 2 - 3 h, continue stirring and perform shearing and grinding in sequence to obtain the glue solution;

[0012] (3) Laminating: Immerse the glass cloth in the adhesive solution, apply ultrasonic waves at 40 - 50 °C and 30 - 40 kHz for 20 - 30 min, take it out and dry at 80 - 90 °C for 4 - 5 h, immerse it in the adhesive solution again, let it stand at 40 - 50 °C for 30 - 40 min, take it out and dry at 80 - 90 °C for 4 - 5 h, then bake it through a vertical dryer, with the baking temperature of 190 - 210 °C and the baking time of 2 - 3 min to obtain a prepreg. Then stack and laminate it with a copper foil with a thickness of 50 μm, with a heating rate of 8 - 10 °C / min, a lamination temperature of 230 - 240 °C, a lamination pressure of 2.7 - 2.9 MPa, a vacuum value of 18 - 20 Torr, and a lamination time of 130 - 150 min, and cool it to room temperature to obtain a copper clad laminate that is not prone to leakage and tracking.

[0013] As an optimization, the tetraethyl orthosilicate solution in step (1) is prepared by uniformly mixing tetraethyl orthosilicate and absolute ethanol in a mass ratio of 1:6 - 1:8.

[0014] As an optimization, the tetrafunctional epoxy resin in step (2) is AG - 80 tetrafunctional epoxy resin; the coupling agent is KBM - 403 coupling agent.

[0015] As an optimization, the equipment for shearing in step (2) is an ultra - fine shear pump, and the process parameters are: shear speed of 3500 - 4500 r / min, shear current of 55 - 65 A, shear temperature of 40 - 50 °C, feed delay of 10 sec, and discharge delay of 15 sec.

[0016] As an optimization, the equipment for grinding in step (2) is a sand mill, and the process parameters are: grinding speed of 1000 - 1200 r / min, grinding temperature of 40 - 50 °C, and grinding time of 4 - 6 h.

[0017] As an optimization, the glass cloth in step (3) is an electronic - grade 7628M glass cloth.

[0018] As an optimization, the copper foil in step (3) is an HTE copper foil.

[0019] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0020] When preparing the copper clad laminate that is not prone to leakage and tracking, the present invention first mixes KBJS - 600A70 resin, tetrafunctional epoxy resin, dicyandiamide, coupling agent, modified silicon carbide whiskers, and N,N - dimethylformamide to obtain a first - stage material; mixes KBJS - 600A70 resin, 2 - methylimidazole, aluminum hydroxide, and ammonium persulfate to obtain a second - stage material. After stirring, shearing, and grinding the first - stage material, heat the second - stage material and stir, shear, and grind it again to obtain an adhesive solution. After impregnating the glass cloth with the adhesive solution and baking, a prepreg is obtained. Stack and laminate the prepreg and the copper foil to obtain a copper clad laminate that is not prone to leakage and tracking.

[0021] First, the silicon carbide whiskers are successively reacted with tetraethyl orthosilicate and trimethoxysilane to obtain pre-modified silicon carbide whiskers. Then, the pre-modified silicon carbide whiskers are successively reacted with triallylsilane and triethoxysilane to obtain modified silicon carbide whiskers. Tetraethyl orthosilicate is used to pre-modify the silicon carbide whiskers, and a silicon dioxide layer is deposited on the surface of the silicon carbide whiskers, which has good insulation effect. After pre-modifying the silicon carbide whiskers, further modification is carried out, so that hyperbranched polysilcarbosilane branches grow on the surface of the modified silicon carbide whiskers, improving the dispersibility of the modified silicon carbide whiskers. The hyperbranched polysilcarbosilane branches grown on the surface have a large number of carbon-carbon double bonds and triethoxysilyl groups. The carbon-carbon double bonds can undergo free radical polymerization under the initiation of ammonium persulfate, and the triethoxysilyl groups can form silicon hydroxyl groups to crosslink with each other and can be connected to the copper foil to form a crosslinked network of modified silicon carbide whiskers, protecting the main component and other components, thereby improving the peel resistance performance. Moreover, the hyperbranched polysilcarbosilane branches have good insulation, thus improving the anti-tracking performance.

[0022] Secondly, the first-stage material is stirred, sheared, and ground, and then heated, and the second-stage material is stirred, sheared, and ground again to obtain a glue solution. Stirring, shearing, and grinding are carried out twice in the first stage and the second stage, ensuring the uniform dispersion of each component of the glue solution, thereby improving the peel resistance performance and the anti-tracking performance. Specific Embodiments

[0023] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present invention.

[0024] In order to more clearly illustrate the method provided by the present invention, the following embodiments are used for detailed description. The test methods for each index of the copper clad laminate with low tracking performance prepared in the following embodiments are as follows:

[0025] Peel resistance performance: The copper clad laminates with low tracking performance obtained in each embodiment and the materials of the comparative examples are taken in the same size and shape, and the peel strength is tested.

[0026] Anti-tracking performance: The copper clad laminates with low tracking performance obtained in each embodiment and the materials of the comparative examples are taken in the same size and shape. The highest voltage value at which the material surface can withstand 50 drops of electrolyte without forming a leakage trace is recorded as the CTI value.

[0027] Example 1

[0028] A preparation process of a copper clad laminate with low tracking performance, the preparation process of the copper clad laminate with low tracking performance mainly includes the following preparation steps:

[0029] (1) Preparation of modified silicon carbide whiskers: Mix tetraethyl orthosilicate and absolute ethanol in a mass ratio of 1:6 to prepare a tetraethyl orthosilicate solution evenly; mix silicon carbide whiskers and pure water in a mass ratio of 1:50 evenly, stir at 10 °C and 200 r / min for 30 min, keep the stirring speed unchanged and dropwise add a tetraethyl orthosilicate solution 15 times the mass of the silicon carbide whiskers at a speed of 0.1 mL / s. After the titration, continue to stir for 30 min, perform ultrasonic treatment at 50 °C and 30 kHz for 8 h, filter and wash 3 times with pure water and absolute ethanol respectively, dry at 60 °C for 6 h, then mix evenly with trimethoxysilane, pure water and absolute ethanol in a mass ratio of 1:1:10:10, perform ultrasonic treatment at 50 °C and 30 kHz for 8 h, filter and wash 3 times with pure water and absolute ethanol respectively, dry at 90 °C for 6 h to obtain pre-modified silicon carbide whiskers; mix the pre-modified silicon carbide whiskers, triallylsilane and n-hexane in a mass ratio of 1:1:5 evenly, then add chloroplatinic acid 0.03 times the mass of triallylsilane, stir and reflux at 70 °C and 500 r / min for 6 h, then add triethoxysilane 3 times the mass of triallylsilane, continue to stir and reflux for 4 h, and let it stand at 20 °C and 1 kPa for 4 h to obtain modified silicon carbide whiskers;

[0030] (2) Mixing and shear grinding: Mix KBJS-600A70 resin, AG-80 tetrafunctional epoxy resin, dicyandiamide, KBM-403 coupling agent, modified silicon carbide whiskers and N,N-dimethylformamide in a mass ratio of 20:1:3:0.05:11:12 to prepare a first-stage material evenly; mix KBJS-600A70 resin, 2-methylimidazole, aluminum hydroxide and ammonium persulfate in a mass ratio of 11:0.01:3:0.4 to prepare a second-stage material evenly; stir the first-stage material at 30 °C and 1200 r / min for 3 h, continue to stir and perform shear with an ultra-fine shear pump, the shear speed is 3500 r / min, the shear current is 55 A, the shear temperature is 40 °C, the feed delay is 10 s, and the discharge delay is 15 s; then grind with a sand mill, and the grinding process parameters are: the grinding speed is 1000 r / min, the grinding temperature is 40 °C, the grinding time is 6 h, add the second-stage material 0.9 times the mass of the first-stage material, stir at 30 °C and 1200 r / min for 3 h, continue to stir and perform shear and grinding in sequence to obtain a glue solution;

[0031] (3) Laminating: Immerse the electronic-grade 7628M glass cloth in the sizing solution, apply ultrasound at 40 °C and 30 kHz for 30 min, take it out and dry it at 80 °C for 5 h. Immerse it in the sizing solution again, let it stand at 40 °C for 40 min, take it out and dry it at 80 °C for 5 h. Then bake it in a vertical dryer at a baking temperature of 190 °C and a baking time of 3 min to obtain a prepreg. Then stack and laminate it with an HTE copper foil with a thickness of 50 μm. The heating rate is 8 °C / min, the lamination temperature is 230 °C, the lamination pressure is 2.7 MPa, the vacuum value is 18 Torr, and the lamination time is 150 min. Cool it to room temperature to obtain a copper clad laminate that is not prone to leakage and tracking.

[0032] Example 2

[0033] A preparation process of a copper clad laminate that is not prone to leakage and tracking, the preparation process of the copper clad laminate that is not prone to leakage and tracking mainly includes the following preparation steps:

[0034] (1) Preparation of modified silicon carbide whiskers: Mix tetraethyl orthosilicate and absolute ethanol in a mass ratio of 1:7 to prepare a tetraethyl orthosilicate solution; mix silicon carbide whiskers and pure water in a mass ratio of 1:55, stir at 20 °C and 250 r / min for 25 min, keep the stirring speed unchanged and dropwise add a tetraethyl orthosilicate solution 18 times the mass of the silicon carbide whiskers at a speed of 0.15 mL / s. After the titration is completed, continue to stir for 35 min, apply ultrasound at 55 °C and 35 kHz for 7 h, filter and wash 4 times with pure water and absolute ethanol respectively, dry at 65 °C for 5 h, and then mix evenly with trimethoxysilane, pure water and absolute ethanol in a mass ratio of 1.5:1:12:12, apply ultrasound at 55 °C and 35 kHz for 7 h, filter and wash 4 times with pure water and absolute ethanol respectively, dry at 95 °C for 5 h to obtain pre-modified silicon carbide whiskers; mix the pre-modified silicon carbide whiskers, triallylsilane and n-hexane in a mass ratio of 1:1:6.5, add chloroplatinic acid 0.04 times the mass of triallylsilane, stir and reflux at 75 °C and 650 r / min for 5 h, then add triethoxysilane 3.5 times the mass of triallylsilane, continue to stir and reflux for 5 h, and let it stand at 25 °C and 1.5 kPa for 3.5 h to obtain modified silicon carbide whiskers;

[0035] (2) Mixing, shearing and grinding: Mix KBJS-600A70 resin, AG-80 tetrafunctional epoxy resin, dicyandiamide, KBM-403 coupling agent, modified silicon carbide whiskers, and N,N-dimethylformamide evenly according to the mass ratio of 23:1:3.5:0.06:12:13 to prepare the first-stage material; Mix KBJS-600A70 resin, 2-methylimidazole, aluminum hydroxide, and ammonium persulfate evenly according to the mass ratio of 12:0.01:3.5:0.5 to prepare the second-stage material; Stir the first-stage material at 35°C and 1400 r / min for 2.5 h, continue stirring and perform ultra-fine shearing by a shearing pump. The shearing speed is 4000 r / min, the shearing current is 60 A, the shearing temperature is 45°C, the feeding delay is 10 s, and the discharging delay is 15 s; Then grind with a sand mill. The grinding process parameters are: the grinding speed is 1100 r / min, the grinding temperature is 45°C, and the grinding time is 5.5 h. Add the second-stage material with a mass 1 time that of the first-stage material, stir at 35°C and 1400 r / min for 2.5 h, continue stirring and perform shearing and grinding in sequence to obtain the adhesive solution;

[0036] (3) Laminating: Immerse the electronic-grade 7628M glass cloth in the adhesive solution, perform ultrasonic treatment at 45°C and 35 kHz for 25 min, take it out and dry it at 85°C for 4.5 h, immerse it in the adhesive solution again, stand it at 45°C for 35 min, take it out and dry it at 85°C for 4.5 h, and then bake it in a vertical dryer. The baking temperature is 200°C and the baking time is 2.5 min to obtain the prepreg. Then stack and laminate it with the HTE copper foil with a thickness of 50 μm. The heating rate is 9°C / min, the laminating temperature is 235°C, the laminating pressure is 2.8 MPa, the vacuum value is 19 Torr, and the laminating time is 140 min. Cool it to room temperature to obtain the copper clad laminate that is not prone to leakage tracking.

[0037] Example 3

[0038] A preparation process for a copper clad laminate that is not prone to leakage tracking. The preparation process for the copper clad laminate that is not prone to leakage tracking mainly includes the following preparation steps:

[0039] (1) Preparation of modified silicon carbide whiskers: Mix tetraethyl orthosilicate and absolute ethanol in a mass ratio of 1:8 to prepare a tetraethyl orthosilicate solution evenly; mix silicon carbide whiskers and pure water in a mass ratio of 1:60 evenly, stir at 30 °C and 300 r / min for 20 min, keep the stirring speed unchanged and dropwise add a tetraethyl orthosilicate solution 20 times the mass of the silicon carbide whiskers at a speed of 0.2 mL / s. After the titration is completed, continue to stir for 30 min, perform ultrasonic treatment at 60 °C and 40 kHz for 6 h, filter and wash 5 times with pure water and absolute ethanol respectively, dry at 70 °C for 4 h, and then mix evenly with trimethoxysilane, pure water and absolute ethanol in a mass ratio of 2:1:15:15, perform ultrasonic treatment at 60 °C and 40 kHz for 6 h, filter and wash 5 times with pure water and absolute ethanol respectively, dry at 100 °C for 4 h to obtain pre-modified silicon carbide whiskers; mix the pre-modified silicon carbide whiskers, triallylsilane and n-hexane in a mass ratio of 1:1:8 evenly, then add chloroplatinic acid 0.05 times the mass of triallylsilane, stir and reflux at 80 °C and 800 r / min for 4 h, then add triethoxysilane 4 times the mass of triallylsilane, continue to stir and reflux for 6 h, and stand at 30 °C and 2 kPa for 3 h to obtain modified silicon carbide whiskers;

[0040] (2) Mixing and shear grinding: Mix KBJS-600A70 resin, AG-80 tetrafunctional epoxy resin, dicyandiamide, KBM-403 coupling agent, modified silicon carbide whiskers and N,N-dimethylformamide in a mass ratio of 25:1:4:0.07:13:14 to prepare a first-stage material evenly; mix KBJS-600A70 resin, 2-methylimidazole, aluminum hydroxide and ammonium persulfate in a mass ratio of 13:0.01:4:0.6 to prepare a second-stage material evenly; stir the first-stage material at 40 °C and 1600 r / min for 2 h, continue to stir and perform shear by an ultra-fine shear pump, with a shear speed of 4500 r / min, a shear current of 65 A, a shear temperature of 50 °C, a feed delay of 10 sec, and a discharge delay of 15 sec; then perform grinding with a sand mill, and the grinding process parameters are: a grinding speed of 1200 r / min, a grinding temperature of 50 °C, and a grinding time of 6 h. Add the second-stage material 1.1 times the mass of the first-stage material, stir at 40 °C and 1600 r / min for 2 h, continue to stir and perform shear and grinding in sequence to obtain a glue solution;

[0041] (3) Laminating: Immerse the electronic-grade 7628M glass cloth in the sizing solution, perform ultrasonic treatment at 50°C and 40 kHz for 20 min, take it out and dry it at 90°C for 4 h, then immerse it in the sizing solution again, let it stand at 40°C for 40 min, take it out and dry it at 80°C for 5 h, and then bake it through a vertical dryer at a baking temperature of 190°C and a baking time of 3 min to obtain a prepreg. Then stack and laminate it with an HTE copper foil with a thickness of 50 μm, with a heating rate of 8°C / min, a lamination temperature of 240°C, a lamination pressure of 2.9 MPa, a vacuum value of 20 Torr, and a lamination time of 150 min. Cool it to room temperature to obtain a copper clad laminate that is not prone to leakage and tracking.

[0042] Comparative Example 1

[0043] A preparation process for a copper clad laminate that is not prone to leakage and tracking, the preparation process for the copper clad laminate that is not prone to leakage and tracking mainly includes the following preparation steps:

[0044] (1) Preparation of modified silicon carbide whiskers: Mix tetraethyl orthosilicate and absolute ethanol evenly according to a mass ratio of 1:7 to prepare a tetraethyl orthosilicate solution; mix silicon carbide whiskers and pure water evenly according to a mass ratio of 1:55, stir at 20°C and 250 r / min for 25 min, keep the stirring speed unchanged and dropwise add a tetraethyl orthosilicate solution 18 times the mass of the silicon carbide whiskers at a speed of 0.15 mL / s. After the titration is completed, continue stirring for 35 min, perform ultrasonic treatment at 55°C and 35 kHz for 7 h, filter and wash it 4 times with pure water and absolute ethanol respectively, dry it at 65°C for 5 h, and then mix it evenly with trimethoxysilane, pure water and absolute ethanol according to a mass ratio of 1.5:1:12:12, perform ultrasonic treatment at 55°C and 35 kHz for 7 h, filter and wash it 4 times with pure water and absolute ethanol respectively, and dry it at 95°C for 5 h to obtain modified silicon carbide whiskers;

[0045] (2) Mixing and shear grinding: Mix KBJS-600A70 resin, AG-80 tetrafunctional epoxy resin, dicyandiamide, KBM-403 coupling agent, modified silicon carbide whiskers, and N,N-dimethylformamide evenly according to the mass ratio of 23:1:3.5:0.06:12:13 to prepare a first-stage material; mix KBJS-600A70 resin, 2-methylimidazole, aluminum hydroxide, and ammonium persulfate evenly according to the mass ratio of 12:0.01:3.5:0.5 to prepare a second-stage material; stir the first-stage material at 35°C and 1400 r / min for 2.5 h, continue stirring and perform ultra-fine shear pump shearing, with a shearing speed of 4000 r / min, a shearing current of 60 A, a shearing temperature of 45°C, a feeding delay of 10 sec, and a discharging delay of 15 sec; then grind with a sand mill, and the grinding process parameters are: a grinding speed of 1100 r / min, a grinding temperature of 45°C, and a grinding time of 5.5 h. Add the second-stage material with a mass 1 time that of the first-stage material, stir at 35°C and 1400 r / min for 2.5 h, continue stirring and perform shearing and grinding in sequence to obtain a glue solution;

[0046] (3) Laminating: Immerse the electronic grade 7628M glass cloth in the glue solution, perform ultrasonic treatment at 45°C and 35 kHz for 25 min, take it out and dry at 85°C for 4.5 h, immerse it in the glue solution again, let it stand at 45°C for 35 min, take it out and dry at 85°C for 4.5 h, and then bake it through a vertical dryer, with a baking temperature of 200°C and a baking time of 2.5 min to obtain a prepreg. Then stack and laminate it with an HTE copper foil with a thickness of 50 μm, with a heating rate of 9°C / min, a laminating temperature of 235°C, a laminating pressure of 2.8 MPa, a vacuum value of 19 Torr, and a laminating time of 140 min. Cool it to room temperature to obtain a copper clad laminate that is not prone to leakage and tracking.

[0047] Comparative Example 2

[0048] A preparation process of a copper clad laminate that is not prone to leakage and tracking, and the preparation process of the copper clad laminate that is not prone to leakage and tracking mainly includes the following preparation steps:

[0049] (1) Mixing, shearing and grinding: Mix KBJS-600A70 resin, AG-80 tetrafunctional epoxy resin, dicyandiamide, KBM-403 coupling agent, silicon carbide whiskers, and N,N-dimethylformamide evenly according to the mass ratio of 23:1:3.5:0.06:12:13 to prepare the first-stage material; Mix KBJS-600A70 resin, 2-methylimidazole, aluminum hydroxide, and ammonium persulfate evenly according to the mass ratio of 12:0.01:3.5:0.5 to prepare the second-stage material; Stir the first-stage material at 35°C and 1400 r / min for 2.5 h, continue stirring and perform ultra-fine shearing pump shearing, with a shearing speed of 4000 r / min, a shearing current of 60 A, a shearing temperature of 45°C, a feeding delay of 10 sec, and a discharging delay of 15 sec; Then grind with a sand mill, and the grinding process parameters are: a grinding speed of 1100 r / min, a grinding temperature of 45°C, and a grinding time of 5.5 h. Add the second-stage material with a mass 1 time that of the first-stage material, stir at 35°C and 1400 r / min for 2.5 h, continue stirring and perform shearing and grinding in sequence to obtain the adhesive solution;

[0050] (2) Laminating: Immerse the electronic-grade 7628M glass cloth in the adhesive solution, perform ultrasonic treatment at 45°C and 35 kHz for 25 min, take it out and dry it at 85°C for 4.5 h, immerse it in the adhesive solution again, let it stand at 45°C for 35 min, take it out and dry it at 85°C for 4.5 h, and then bake it through a vertical dryer, with a baking temperature of 200°C and a baking time of 2.5 min to obtain the prepreg. Then stack and laminate it with an HTE copper foil with a thickness of 50 μm, with a heating rate of 9°C / min, a laminating temperature of 235°C, a laminating pressure of 2.8 MPa, a vacuum value of 19 Torr, and a laminating time of 140 min. Cool it to room temperature to obtain a copper clad laminate that is not prone to leakage and tracking.

[0051] Comparative Example 3

[0052] A preparation process for a copper clad laminate that is not prone to leakage and tracking. The preparation process for the copper clad laminate that is not prone to leakage and tracking mainly includes the following preparation steps:

[0053] (1) Preparation of modified silicon carbide whiskers: Mix tetraethyl orthosilicate and absolute ethanol evenly according to a mass ratio of 1:7 to prepare a tetraethyl orthosilicate solution; mix silicon carbide whiskers and pure water evenly according to a mass ratio of 1:55, stir at 20 °C and 250 r / min for 25 min, keep the stirring speed unchanged and dropwise add a tetraethyl orthosilicate solution 18 times the mass of the silicon carbide whiskers at a speed of 0.15 mL / s. After the titration is completed, continue to stir for 35 min, ultrasonicate at 55 °C and 35 kHz for 7 h, filter and wash 4 times with pure water and absolute ethanol respectively, dry at 65 °C for 5 h, and then mix evenly with trimethoxysilane, pure water and absolute ethanol according to a mass ratio of 1.5:1:12:12, ultrasonicate at 55 °C and 35 kHz for 7 h, filter and wash 4 times with pure water and absolute ethanol respectively, dry at 95 °C for 5 h to obtain pre-modified silicon carbide whiskers; mix the pre-modified silicon carbide whiskers, triallylsilane and n-hexane evenly according to a mass ratio of 1:1:6.5, add chloroplatinic acid 0.04 times the mass of triallylsilane, stir and reflux at 75 °C and 650 r / min for 5 h, then add triethoxysilane 3.5 times the mass of triallylsilane, continue to stir and reflux for 5 h, and let stand at 25 °C and 1.5 kPa for 3.5 h to obtain modified silicon carbide whiskers;

[0054] (2) Mixing, shearing and grinding: Mix KBJS-600A70 resin, AG-80 tetrafunctional epoxy resin, dicyandiamide, KBM-403 coupling agent, modified silicon carbide whiskers and N,N-dimethylformamide evenly according to a mass ratio of 23:1:3.5:0.06:12:13 to prepare a first-stage material; mix KBJS-600A70 resin, 2-methylimidazole, aluminum hydroxide and ammonium persulfate evenly according to a mass ratio of 12:0.01:3.5:0.5 to prepare a second-stage material; mix the first-stage material and the second-stage material, stir at 35 °C and 1400 r / min for 2.5 h, continue to stir and carry out ultra-fine shear pump shearing, with a shear speed of 4000 r / min, a shear current of 60 A, a shear temperature of 45 °C, a feed delay of 10 sec, and a discharge delay of 15 sec; then grind with a sand mill, and the grinding process parameters are: a grinding speed of 1100 r / min, a grinding temperature of 45 °C, and a grinding time of 5.5 h to obtain a glue solution;

[0055] (3) Laminating: Immerse the electronic grade 7628M glass cloth in the adhesive solution, apply ultrasound at 45 °C and 35 kHz for 25 min, take it out and dry at 85 °C for 4.5 h, immerse it in the adhesive solution again, let it stand at 45 °C for 35 min, take it out and dry at 85 °C for 4.5 h, then bake it in a vertical dryer at a baking temperature of 200 °C and a baking time of 2.5 min to obtain a prepreg. Then stack and laminate it with a 50-μm-thick HTE copper foil, with a heating rate of 9 °C / min, a lamination temperature of 235 °C, a lamination pressure of 2.8 MPa, a vacuum value of 19 Torr, and a lamination time of 140 min. Cool it to room temperature to obtain a copper clad laminate that is not prone to leakage and tracking.

[0056] Effect Example

[0057] Table 1 below gives the performance analysis results of the peel resistance and anti-tracking performance of the copper clad laminates that are not prone to leakage and tracking prepared in Examples 1 to 3 and Comparative Examples 1 to 3 of the present invention.

[0058] Table 1

[0059] Peeling strength CTI value Peeling strength CTI value Example 1 1.35 N / mm 622 Comparative Example 1 0.95 N / mm 552 Example 2 1.35 N / mm 624 Comparative Example 2 0.92 N / mm 481 Example 3 1.33 N / mm 617 Comparative Example 3 1.16 N / mm 574

[0060] From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 3 in Table 1, it can be found that the copper clad laminates prepared by the present invention have good peel resistance and anti-tracking performance.

[0061] From the comparison of the experimental data of Examples 1, 2, 3 and Comparative Example 1, it can be found that the peel strength and CTI value of Examples 1, 2, 3 are higher than those of Comparative Example 1. This shows that after pre-modifying the silicon carbide whiskers and then carrying out modification, hyperbranched polysilcarbosilane branches grow on the surface of the modified silicon carbide whiskers, improving the dispersibility of the modified silicon carbide whiskers. The hyperbranched polysilcarbosilane branches grown on the surface have a large number of carbon-carbon double bonds and triethoxysilyl groups. The carbon-carbon double bonds can undergo free radical polymerization under the initiation of ammonium persulfate, and the triethoxysilyl groups can form cross-links through silanol groups to form a cross-linked network of modified silicon carbide whiskers, protecting the main components and other components, thereby improving the peel resistance of the copper clad laminate that is not prone to leakage tracking. Moreover, the hyperbranched polysilcarbosilane branches have good insulation properties, thus improving the anti-tracking performance of the copper clad laminate that is not prone to leakage tracking. From the comparison of the experimental data of Comparative Example 1 and Comparative Example 2, it can be found that the CTI value of Comparative Example 1 is higher than that of Comparative Example 2. This shows that pre-modifying the silicon carbide whiskers with tetraethyl orthosilicate, and tetraethyl orthosilicate deposits into a silica layer on the surface of the silicon carbide whiskers, which has good insulation effect, thereby improving the anti-tracking performance of the copper clad laminate that is not prone to leakage tracking. From the comparison of the experimental data of Examples 1, 2, 3 and Comparative Example 3, it can be found that the peel strength and CTI value of Examples 1, 2, 3 are higher than those of Comparative Example 3. This shows that through two-stage stirring, shearing and grinding, the dispersion of each component of the adhesive solution is ensured to be uniform, thereby improving the peel resistance and anti-tracking performance of the copper clad laminate that is not prone to leakage tracking.

[0062] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be regarded as limiting the claimed rights.

Claims

1. Preparation process of a copper clad laminate that is not prone to leakage tracking, characterized in that, The preparation process of the copper clad laminate with low tracking resistance includes the following preparation steps: (1) Preparation of modified silicon carbide whiskers: Mix silicon carbide whiskers and pure water in a mass ratio of 1:50 to 1:60 evenly, stir at 10 - 30 °C and 200 - 300 r / min for 20 - 30 min. While keeping the stirring speed unchanged, dropwise add tetraethyl orthosilicate solution which is 15 - 20 times the mass of the silicon carbide whiskers at a speed of 0.1 - 0.2 mL / s. After the titration, continue stirring for 20 - 30 min, carry out ultrasonic treatment at 50 - 70 °C and 30 - 40 kHz for 6 - 8 h, filter and wash 3 - 5 times with pure water and anhydrous ethanol respectively, dry at 60 - 70 °C for 4 - 6 h, then mix evenly with trimethoxysilane, pure water and anhydrous ethanol in a mass ratio of 1:1:10:10 to 2:1:15:15, carry out ultrasonic treatment at 50 - 60 °C and 30 - 40 kHz for 6 - 8 h, filter and wash 3 - 5 times with pure water and anhydrous ethanol respectively, dry at 90 - 100 °C for 4 - 6 h to obtain pre-modified silicon carbide whiskers; Mix the pre-modified silicon carbide whiskers, triallylsilane and n-hexane in a mass ratio of 1:1:5 to 1:1:8 evenly, then add chloroplatinic acid which is 0.03 - 0.05 times the mass of triallylsilane, stir and reflux at 70 - 80 °C and 500 - 800 r / min for 4 - 6 h, then add triethoxysilane which is 3 - 4 times the mass of triallylsilane, continue stirring and refluxing for 4 - 6 h, and let it stand at 20 - 30 °C and 1 - 2 kPa for 3 - 4 h to obtain modified silicon carbide whiskers; (2) Mixing, shearing and grinding: Mix KBJS-600A70 resin, tetrafunctional epoxy resin, dicyandiamide, coupling agent, modified silicon carbide whiskers and N,N-dimethylformamide in a mass ratio of 20:1:3:0.05:11:12 to 25:1:4:0.07:13:14 evenly to prepare a first-stage material; Mix KBJS-600A70 resin, 2-methylimidazole, aluminum hydroxide and ammonium persulfate in a mass ratio of 11:0.01:3:0.4 to 13:0.01:4:0.6 evenly to prepare a second-stage material; Stir the first-stage material at 30 - 40 °C and 1200 - 1600 r / min for 2 - 3 h, continue stirring and carry out shearing and grinding in sequence, then add the second-stage material which is 0.9 - 1.1 times the mass of the first-stage material, stir at 30 - 40 °C and 1200 - 1600 r / min for 2 - 3 h, continue stirring and carry out shearing and grinding in sequence to obtain the adhesive solution; (3)Laminating: Immerse the glass cloth in the adhesive solution, apply ultrasonic waves at 40 - 50°C and 30 - 40 kHz for 20 - 30 min, take it out and dry at 80 - 90°C for 4 - 5 h. Immerse it in the adhesive solution again, let it stand at 40 - 50°C for 30 - 40 min, take it out and dry at 80 - 90°C for 4 - 5 h. Then bake it in a vertical dryer at a baking temperature of 190 - 210°C and a baking time of 2 - 3 min to obtain a prepreg. Then stack and laminate it with a copper foil with a thickness of 50 μm. The heating rate is 8 - 10°C / min, the lamination temperature is 230 - 240°C, the lamination pressure is 2.7 - 2.9 MPa, the vacuum value is 18 - 20 Torr, and the lamination time is 130 - 150 min. Cool it to room temperature to obtain a copper clad laminate that is not prone to leakage tracking.

2. The preparation process of a copper clad laminate that is not prone to leakage tracking according to claim 1, characterized in that, The tetraethyl orthosilicate solution in step (1) is prepared by uniformly mixing tetraethyl orthosilicate and absolute ethanol at a mass ratio of 1:6 - 1:

8.

3. The preparation process of a copper clad laminate that is not prone to leakage tracking according to claim 2, characterized in that, The tetrafunctional epoxy resin in step (2) is AG - 80 tetrafunctional epoxy resin; the coupling agent is KBM - 403 coupling agent.

4. The preparation process of a copper clad laminate that is not prone to leakage tracking as claimed in claim 1, characterized in that, The equipment for shearing in step (2) is an ultra - fine shearing pump, and the process parameters are: shearing speed 3500 - 4500 r / min, shearing current 55 - 65 A, shearing temperature 40 - 50°C, feeding delay 10 sec, discharging delay 15 sec.

5. The preparation process of a copper clad laminate that is not prone to leakage tracking as claimed in claim 1, wherein, The equipment for grinding in step (2) is a sand mill, and the process parameters are: grinding speed 1000 - 1200 r / min, grinding temperature 40 - 50°C, grinding time 4 - 6 h.

6. The preparation process of a copper clad laminate with low tracking resistance according to claim 1, characterized in that, The glass cloth in step (3) is an electronic - grade 7628M glass cloth.

7. The preparation process of a copper clad laminate with low tracking resistance according to claim 1, characterized in that, The copper foil in step (3) is an HTE copper foil.

8. The preparation process of a copper clad laminate with low tracking resistance according to claim 1, characterized in that, The copper clad laminate that is not prone to leakage tracking is obtained by impregnating the glass cloth with the adhesive solution, baking to obtain a prepreg, and then stacking and laminating the prepreg and the copper foil.