A low dielectric resin composition containing a modified spirobifluorene resin, a copper clad plate and application thereof

Abstract

The application discloses a low dielectric resin composition containing a modified spirobifluorene resin and a copper-clad plate prepared from the low dielectric resin composition. Different from the prior art, the application uses the modified spirobifluorene resin and the modified polyphenyl ether resin in combination to meet the requirements of high-frequency copper-clad plates on material flame retardancy and peeling strength, and to improve the problems of insufficient electrical properties and processability of the polyphenyl ether resin.

Description

Technical Field

[0001] This invention relates to the field of copper clad laminate manufacturing, specifically to a low-dielectric resin composition containing modified spirodifluorene resin and the copper clad laminate thereof and its application. Background Technology

[0002] With the rapid development of electronic technology, the information processing of electronic products such as mobile communications, servers, and cloud storage is constantly moving towards higher frequency and higher speed digital signal transmission, which continuously increases the performance requirements of copper clad laminates.

[0003] Especially in the 5G era, printed circuit boards need to possess characteristics such as high heat resistance, high dimensional stability, low dielectric constant, excellent filler properties, and drilling machinability. These requirements pose greater challenges to copper-clad laminate substrate materials, particularly in terms of coefficient of thermal expansion, dielectric constant, and dielectric loss.

[0004] Traditional printed circuit board (PCB) materials primarily use epoxy resins. While epoxy resins offer excellent insulation and chemical resistance, their electrical properties, water absorption, flame retardancy, and dimensional stability are no longer sufficient to meet the demands of high-frequency and broadband communication devices and equipment. To meet the requirements of high-frequency, high-speed copper-clad laminates, some researchers have attempted to use polyphenylene ether (PPE) resins due to their superior properties of low dielectric constant and low dielectric loss. However, PPE resins are typically thermoplastic, have a large molecular weight, poor solvent solubility, and generate polar groups during thermosetting, leading to increased dielectric constant and dielectric loss, higher water absorption, and insufficient heat resistance.

[0005] Therefore, developing a resin material that combines low dielectric properties, excellent thermal properties, and processability has become a current research focus.

[0006] Especially in the semiconductor packaging process, if the difference in thermal expansion coefficients between the semiconductor element and the substrate material is too large, stress can easily be generated, causing material warping and resulting in serious problems such as poor connection between the semiconductor element and the substrate material, and between the substrate material and the PCB. Therefore, developing a resin material that can simultaneously meet the requirements of low thermal expansion coefficient, low dielectric constant, and low dielectric loss is an urgent problem to be solved in the current technological field.

[0007] To address serious issues such as poor connections between semiconductor components and substrate materials, and between substrate materials and PCBs, several invention patents have been developed. For example:

[0008] CN109504062A discloses a thermosetting resin composition. This composition uses a thermosetting polyphenylene ether resin with reactive functional groups at the ends of styrene and acrylic groups, wherein the ratio of the two different functional groups is between 0.5 and 1.5, a thermosetting polybutadiene resin, and contains at least one thermoplastic resin. This composition can effectively increase the crosslinking density during thermosetting, and after curing, it achieves characteristics such as low dielectric constant, low dielectric loss, high Tg, high rigidity, and good cutability of prepreg sheets. However, this patent still has issues with the electrical properties and processability of the polyphenylene ether resin requiring further improvement. Specifically, the issues requiring improvement are as follows:

[0009] Although polyphenylene ether resin has excellent properties of low dielectric constant and low dielectric loss, it is usually thermoplastic and has a large molecular weight, resulting in poor solubility in solvents. During the thermosetting process, polar groups are generated, which leads to an increase in dielectric constant and dielectric loss, increased water absorption, and insufficient heat resistance. Summary of the Invention

[0010] In order to overcome the above-mentioned defects of the prior art, the present invention aims to provide a low dielectric resin composition, its preparation method and its application.

[0011] Unlike existing technologies, this invention utilizes a combination of modified spirodifluorene resin and modified polyphenylene ether resin. This satisfies the requirements of high-frequency copper-clad laminates for flame retardancy and peel strength while improving the shortcomings of polyphenylene ether resin in terms of electrical properties and processability.

[0012] To achieve the objectives of this invention, the technical solution adopted is as follows:

[0013] A low-dielectric resin composition containing modified spirobifluorene resin, comprising the following components by weight:

[0014] 80-150 parts of modified spirodifluorene resin;

[0015] 50-100 parts of modified polyphenylene ether resin;

[0016] 15-25 parts of crosslinking agent;

[0017] 50-100 parts of inorganic filler material;

[0018] Initiator 0.2–3 parts;

[0019] The modified spirodifluorene resin has the following structural formula: Formula 1:

[0020]

[0021] Formula 1;

[0022] R1-R4 in Formula 1 are hydrogen groups, C1-C6 groups, alkyl groups, or any of the groups in Formulas 2-5 below;

[0023]

[0024] Formula 2;

[0025]

[0026] Formula 3;

[0027]

[0028] Equation 4;

[0029]

[0030] Formula 5;

[0031] The modified polyphenylene ether resin is an acrylate-terminated and / or styrene-terminated modified polyphenylene ether resin.

[0032] In a preferred embodiment of the present invention, the modified spirobifluorene resin is a modified spirobifluorene resin as shown in Formula 6 or Formula 7 below;

[0033]

[0034] Formula 6;

[0035]

[0036] Formula 7.

[0037] In a preferred embodiment of the present invention, the modified polyphenylene ether resin is an acrylate-terminated and / or styrene-terminated modified polyphenylene ether resin, wherein the number average molecular weight of the acrylate-terminated and / or styrene-terminated modified polyphenylene ether resin is 400 to 4000 g / mol.

[0038] The acrylate-terminated and / or styrene-terminated modified polyphenylene ether resin has a molecular weight distribution of 1.0 to 2.4.

[0039] The grafting rate of the acrylate-terminated and / or styrene-terminated modified polyphenylene ether resin is 5% to 30%.

[0040] Methacrylate-modified polyphenylene ether resin or styrene-modified polyphenylene ether resin are preferred.

[0041] In a preferred embodiment of the present invention, the crosslinking agent is any one or more of a triallenyl isocyanurate compound, a polyfunctional acrylate compound, a polyfunctional methacrylate compound, a polyfunctional vinyl compound, or a divinylbenzene compound.

[0042] In a preferred embodiment of the present invention, the inorganic filler material is a low-dielectric synthetic spherical silica filler, which is a spherical silica filler whose surface has been treated with a vinyl silane coupling agent, a propylene silane coupling agent, or a (meth)acrylate silane coupling agent. The spherical silica filler has a dielectric loss of less than 0.0014 at a frequency of 10 GHz. The average particle size D50 of the spherical silica filler is in the range of 0.5-5 μm.

[0043] In a preferred embodiment of the present invention, the initiator is any one or more of azobisisobutyronitrile, azobis(2-isopropyl)butyronitrile, azobis(hexamethylene)dicarbonitrile, benzoyl peroxide, dimethylbenzoyl peroxide, diisopropionyl peroxide, diisopropylbenzene peroxide, cyclohexanone peroxide, methyl ethyl ketone peroxide, dicyclohexyl peroxide, benzoic acid peroxide, tert-butyl peroxide, butylbenzoic acid peroxide, or tert-butylbenzoic acid peroxide.

[0044] A copper-clad laminate containing the aforementioned low-dielectric resin composition is obtained by the following preparation method:

[0045] The first step involves mixing the components of the low-dielectric resin composition containing modified spirodifluorene resin until the resin is completely dissolved, then applying the mixture as an adhesive onto a glass fiber cloth, and drying and curing it to allow the solvent to evaporate, thus obtaining a prepreg.

[0046] The linear speed for applying the adhesive is 8-25 m / min; the drying and curing temperature is 110-230℃.

[0047] The second step is to press the prepreg and copper foil together to obtain the copper-clad laminate.

[0048] The pressing pressure is 70-600 psi, the temperature is 70-240℃, the vacuum degree is 0.02-0.1MPa, the curing time is 50-130min, and the pressing time is 70-200min.

[0049] In a preferred embodiment of the present invention, the glass fiber cloth is a Q-grade glass fiber cloth.

[0050] In a preferred embodiment of the present invention, the copper foil is 1 / 3 oz, Hoz, 1 oz, 2 oz, 3 oz, 4 oz or HPLV grade copper foil.

[0051] In a preferred embodiment of the present invention, the copper clad laminate is a glass cloth-based copper clad foil with dimensions of 36×48, 37×49, 40×48, 40.5×48.5, 41×49, 42.5×48.5, or 43×49.

[0052] An application of copper-clad laminate, said application being the fabrication of PCB circuit boards for semiconductor packaging.

[0053] The beneficial effects of this invention are as follows:

[0054] This invention utilizes a combination of modified spirodifluorene resin and modified polyphenylene ether resin. This satisfies the requirements of high-frequency copper-clad laminates for flame retardancy and peel strength while improving the insufficient electrical properties and processability of polyphenylene ether resin. Detailed Implementation

[0055] The specific embodiments described herein are merely illustrative of the invention and are not intended to limit its scope. Furthermore, descriptions of well-known structures and techniques have been omitted in the following descriptions to avoid unnecessarily obscuring the concepts of the invention.

[0056] To meet the requirements of low dielectric properties and dielectric loss characteristics of the resin composition, polyphenylene ether (PPE) resin is used as the main component of the composition in this invention. Considering that the addition of traditional combustion improvers to polyphenylene ether will affect heat resistance and increase dielectric loss, this invention limits the polyphenylene ether by introducing phosphorus-containing unit segments on the methyl group of the repeating unit dimethylbenzene and controlling its grafting rate, which can improve the glass transition temperature, reduce the coefficient of thermal expansion, and improve dielectric properties.

[0057] In this invention, methacrylate-modified polyphenylene ether (PPE) resins are used, such as methyl methacrylate-terminated modified polyphenylene ether resin Sabic SA-9000.

[0058] Or styrene-modified polyphenylene ether (PPE) resin, such as styrene-terminated polyphenylene ether resin MGCOPE-2st.

[0059] The modified polyphenylene ether (PPE) resin in the examples has a number average molecular weight of 500 to 2500, preferably 700 to 13000, and a molecular weight distribution of 1.0 to 2.4.

[0060] The reason for using a molecular weight distribution of 1.0-2.4 in this invention is as follows:

[0061] On the one hand, 1.0 represents the ideal molecular weight distribution of monodisperse polymers, which is difficult to achieve in actual polymerization preparation. The lower limit of this range can ensure the regularity of the polyphenylene ether molecular chain structure, effectively reduce the content of polar impurities in the system, and endow the composition with excellent high-frequency low dielectric properties and thermal stability. On the other hand, controlling the upper limit of the molecular weight distribution to 2.4 can avoid the drawbacks of an excessively wide molecular weight distribution. It can improve the solubility and flowability of the resin system by relying on an appropriate amount of low molecular weight components, making it suitable for preparation processes such as copper-clad laminate impregnation and hot pressing. It can also maintain the crosslinking density, mechanical strength, and heat resistance of the cured system by relying on high molecular weight components, preventing problems such as a decrease in glass transition temperature, uneven curing, and poor adhesion caused by excessive small molecular weight components. At the same time, it can effectively improve the consistency of the performance of different batches of raw materials. Ultimately, the resulting resin composition has excellent processability, uniform curing reaction, low dielectric properties, and comprehensive thermodynamic properties, meeting the requirements of high-frequency and high-speed printed circuit boards.

[0062] Through extensive testing, the inventors of this invention discovered that when the number average molecular weight of the modified polyphenylene oxide (PPE) resin is below 500, its dielectric properties are poor; when the number average molecular weight is above 25,000, the PPE melt viscosity is too high, the resin system has poor fluidity, and the glass transition temperature and heat resistance will decrease.

[0063] The crosslinking agent used in this invention is selected from one or more of triallyl isocyanurate, triallyl cyanurate, trimethylallyl isocyanurate, trimethylallyl cyanurate, tert-butylstyrene, diallyl isophthalate, diallyl phthalate, trimethylolpropane triacrylate, or trimethylolpropane trimethacrylate. These are then combined separately.

[0064] Crosslinking agents can be used to further enhance the crosslinking reaction of modified spirobifluorene resin, polyphenylene ether resin, and unsaturated polymer resin, thereby increasing the crosslinking density of the material, improving the compactness of the crosslinking network, and enhancing the glass transition temperature and heat resistance of the material.

[0065] The inorganic filler material of the present invention is a low-dielectric synthetic spherical silica filler. The low-dielectric synthetic spherical silica filler is a spherical silica filler whose surface has been treated with a vinyl silane coupling agent, a propylene silane coupling agent, or a (meth)acrylate silane coupling agent. The dielectric loss of the spherical silica filler is less than 0.0014 at a frequency of 10 GHz. The average particle size D50 of the spherical silica filler is in the range of 0.5-5 μm.

[0066] The filler and resin composition system treated with coupling agent has better compatibility, which can further improve the dielectric properties of the composition, while improving the moisture resistance and peel strength to copper foil.

[0067] The core difference between this invention and existing technologies lies in:

[0068] 1. By optimizing the structural design of modified spirodifluorene and the ratio of modified polyphenylene ether resins, this invention significantly improves the rigidity and heat resistance of the resin composition, giving it better dimensional stability and heat treatment performance, thus meeting the higher requirements of high-frequency and high-speed copper clad laminates for the coefficient of thermal expansion of materials.

[0069] 2. The modified spirobifluorene resin of the present invention, when blended with polyphenylene oxide (PPO) resin, can significantly improve the processability, heat resistance, and dielectric properties of the system: the rigid structure of the spirobifluorene skeleton can effectively inhibit the chain segment movement of PPO at high temperatures, increase the glass transition temperature (Tg) and thermal decomposition temperature (Td) of the cured resin, and at the same time, the vinyl groups it contains can undergo cross-linking reactions with the vinyl groups or other active groups at the ends of PPO to form a dense three-dimensional network structure, which significantly improves the cross-linking density and dimensional stability of the cured product; in addition, the low polarity and non-planar rigid structure of the spirobifluorene unit can reduce the molecular packing density and polar group content of the resin system, effectively reduce the dielectric constant (Dk) and dielectric loss (Df) of the cured resin, and improve the interfacial compatibility of PPO with substrates such as fiberglass cloth and copper foil, reducing porosity and delamination defects during the curing process, ultimately obtaining a copper-clad laminate resin composition with excellent high-frequency performance, high thermal stability and good processability, suitable for high-frequency high-speed communication PCBs and AI server substrates and other application scenarios.

[0070] The following is a detailed description with reference to the embodiments. The usage of each component in the embodiments is shown in Table 1 below:

[0071] Table 1

[0072] The synthetic steps for the compound shown in structural formula 6 are as follows:

[0073]

[0074] Formula 6.

[0075] Under nitrogen protection, 2,2',7,7'-tetrabromo-9,9'-spirobisfluorene (63.2 g, 0.1 mol, CAS 128055-74-3, purity ≥98%), 4-benzocyclobutene borate pinacol ester (90.4 g, 0.4 mol, purity ≥98%), anhydrous potassium carbonate (55.3 g, 0.4 mol), and tetra(triphenylphosphine)palladium (2.3 g, 0.002 mol, 2 mol%) were added sequentially to a 2 L three-necked flask. Then, a mixed solvent consisting of toluene (400 mL), anhydrous ethanol (200 mL), and deionized water (100 mL) was added. After stirring thoroughly, the mixture was heated to 85±5℃ and refluxed for 30 h. The reaction was monitored by HPLC until complete. After the reaction, the system was cooled to room temperature, and the aqueous phase was extracted three times with toluene (100 mL each time). Combine all organic phases, wash successively with saturated ammonium chloride solution (2×200 mL) and deionized water (2×200 mL), and dry overnight with anhydrous sodium sulfate; after filtration to remove the desiccant, remove the solvent by rotary evaporation under reduced pressure to obtain crude product. Dissolve the crude product in a toluene / ethanol mixed solvent (volume ratio 3:1, 400 mL in total) by heating under reflux, then slowly cool to room temperature, allow to stand for crystallization, filter to collect the solid, and repeat recrystallization twice; finally, dry the product in an 80℃ vacuum oven for 12 h to obtain the white solid target product 2,2',7,7'-tetratetra(benzocyclobuten-4-yl)-9,9'-spirobis[fluorene], with a yield of 78% and a purity ≥98.5% (HPLC).

[0076] The synthesis steps of the compound shown in structural formula 7 are as follows:

[0077]

[0078] Formula 7.

[0079] Under nitrogen protection, 2,2',7,7'-tetrabromo-9,9'-spirobisfluorene (63.2 g, 0.1 mol, CAS: 128055-74-3, purity ≥98%), pinacol 4-vinylphenylboronic acid (91.3 g, 0.4 mol, CAS: 143646-38-6, purity ≥97%), anhydrous potassium carbonate (55.3 g, 0.4 mol, CAS: 584-08-7, analytical grade), and tetra(triphenylphosphine)palladium(0) (2.3 g, 0.002 mol, 2 mol%, CAS: 14221-01-3, purity ≥97%) were added sequentially to a 2 L three-necked flask. Then, toluene (400 mL), anhydrous ethanol (200 mL), and deionized water (100 mL) were added. A mixed solvent consisting of 2,2',7,7'-tetra(4-vinylphenyl)-9,9'-spirobis[fluorene] was stirred until homogeneous and then refluxed at 85±5℃ for 28 h. The reaction was monitored by HPLC until complete. After the reaction, the system was cooled to room temperature, and the aqueous phase was extracted three times with toluene (100 mL each time). All organic phases were combined and washed successively with saturated ammonium chloride solution (2×200 mL) and deionized water (2×200 mL), and then dried overnight with anhydrous sodium sulfate. After filtering to remove the desiccant, the solvent was removed by rotary evaporation under reduced pressure to obtain the crude product. The crude product was dissolved by heating and refluxing with a toluene / ethanol mixed solvent (volume ratio 3:1, 400 mL in total), and then slowly cooled to room temperature. The product was allowed to stand and crystallize. The solid was collected by filtration and recrystallized twice. Finally, the product was dried in a vacuum oven at 60℃ for 12 h to obtain the white solid target product 2,2',7,7'-tetra(4-vinylphenyl)-9,9'-spirobis[fluorene], with a yield of 75% and a purity ≥98% (HPLC).

[0080] The proportions of each component used in the examples and comparative examples are shown in Table 2 below:

[0081] Table 2

[0082] A copper-clad laminate containing a low-dielectric resin composition of modified spirodifluorene resin is obtained by the following preparation method:

[0083] The first step involves mixing the components of the low-dielectric resin composition containing modified spirodifluorene resin until the resin is completely dissolved. The mixture is then applied as an adhesive onto Q-grade glass fiber cloth and dried to cure the solvent, resulting in a prepreg.

[0084] The linear speed for applying the adhesive is 18 m / min; the drying and curing temperature is 180℃.

[0085] The second step involves stacking the prepreg and copper foil together and pressing them to obtain the copper-clad laminate.

[0086] The pressing pressure is 70-600 psi, and in the embodiments and comparative examples of this invention, the value is 250 psi.

[0087] The pressing temperature is 70-240℃, and in the embodiments and comparative examples of this invention, the value is 220℃.

[0088] The vacuum level of the press is 0.02-0.1 MPa, and in the embodiments and comparative examples of this invention, it is 0.05 MPa.

[0089] The curing time is 50-130 min, and in the embodiments and comparative examples of this invention, the value is 80 min.

[0090] The pressing time is 70-200 min, and in the embodiments and comparative examples of this invention, the value is 120 min.

[0091] The copper foil is 1 / 3 oz, Hoz, 1 oz, 2 oz, 3 oz, 4 oz or HPLV grade copper foil. In the examples of the embodiments and comparative examples of the present invention, HPLV grade copper foil is used.

[0092] The copper clad laminate is a glass cloth-based copper clad laminate with dimensions of 36×48, 37×49, 40×48, 40.5×48.5, 41×49, 42.5×48.5, and 43×49. In the examples of the embodiments and comparative examples of the present invention, a glass cloth-based copper clad laminate with a dimension of 41×49 is used.

[0093] The above parameters for gluing, curing, and pressing can be selected according to the actual product process requirements, and are not limited to the specific parameter settings of the embodiments of the present invention.

[0094] The test standards for embodiments and comparative examples of the present invention are shown below:

[0095] (a) Glass transition temperature (Tg): The peak temperature of Tanδ is determined by dynamic mechanical analysis (DMA) and is taken as the glass transition temperature.

[0096] (ii) Peel strength (PS): The peel strength of the samples was tested using a universal tensile testing machine in accordance with the standard IPC-TM-650-2.4.8.

[0097] (III) 288℃ heat resistance test (T288): Place an 8mm×8mm copper foil substrate on a thermomechanical analyzer (TMA), raise the temperature from room temperature to 288℃ at a heating rate of 10℃ / min and maintain it at 288℃, observe the size change of the sample and record the time when the plate bursts after 288℃.

[0098] (iv) Dielectric constant (Dk) and dielectric loss factor (Df): The test methods for dielectric constant and dielectric loss factor shall be in accordance with the test specified in IPC-TM-650 2.5.5.9;

[0099] (v) Decomposition temperature (Td): Select a square sample with dimensions of 6.35mm × 6.35mm and a minimum sample weight of 30mg. Bake at 110±2℃ for 24 hours and cool to room temperature in a desiccator. Use a thermogravimetric analyzer (TGA) to increase the temperature from room temperature to 450℃ at a rate of 10℃ / min. Record the percentage of weight loss of the sample as the temperature increases. The temperature at which the weight loss is 5% is reported as Td.

[0100] (vi) PCT: The samples were subjected to a steaming test using a pressure cooker. After the plates were steamed continuously at 0.105 MPa and 120℃ for 120 min, they were immersed in a tin furnace at 288℃ to observe the delamination and bubbling time. Samples with a delamination time of less than 5 min were evaluated as ×, and samples with a delamination time of more than 5 min but less than 10 min were evaluated as ○.

[0101] The test structures for the embodiments and comparative examples of the present invention are shown in Table 3 below:

[0102] Table 3

[0103]

[0104] The foregoing has shown and described the basic principles and main features of the invention and the advantages of the invention.

[0105] Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the present invention. Various changes and modifications can be made to the present invention without departing from its spirit and scope. All such changes and modifications fall within the scope of the present invention as claimed, which is defined by the appended claims and their equivalents.

Claims

1. A low-dielectric resin composition containing modified spirodifluorene resin, characterized in that, By weight, it includes the following components: 80-150 parts of modified spirodifluorene resin; 50-100 parts of modified polyphenylene ether resin; 15-25 parts of crosslinking agent; 50-100 parts of inorganic filler material; Initiator 0.2–3 parts; The modified spirodifluorene resin has the following structural formula: Formula 1; R1-R4 in Formula 1 are hydrogen groups, C1-C6 groups, alkyl groups, or any of the groups in Formulas 2-5 below; Formula 2; Formula 3; Equation 4; Formula 5; The modified polyphenylene ether resin is an acrylate-terminated and / or styrene-terminated modified polyphenylene ether resin.

2. The low-dielectric resin composition containing modified spirodifluorene resin as described in claim 1, characterized in that, The modified spirobifluorene resin is the modified spirobifluorene resin shown in Formula 6 or Formula 7 below; Formula 6; Formula 7.

3. The low-dielectric resin composition containing modified spirodifluorene resin as described in claim 1, characterized in that, The modified polyphenylene ether resin is an acrylate-terminated and / or styrene-terminated modified polyphenylene ether resin, and the number average molecular weight of the acrylate-terminated and / or styrene-terminated modified polyphenylene ether resin is 400-4000 g / mol. The acrylate-terminated and / or styrene-terminated modified polyphenylene ether resin has a molecular weight distribution of 1.0 to 2.

4. The grafting rate of the acrylate-terminated and / or styrene-terminated modified polyphenylene ether resin is 5% to 30%.

4. The low-dielectric resin composition containing modified spirodifluorene resin as described in claim 1, characterized in that, The crosslinking agent is any one or more of the following: trienyl isocyanurate compound, polyfunctional acrylate compound, polyfunctional methacrylate compound, polyfunctional vinyl compound, or divinylbenzene compound.

5. The low-dielectric resin composition containing modified spirodifluorene resin as described in claim 1, characterized in that, The inorganic filler material is a low-dielectric synthetic spherical silica filler, which is a spherical silica filler whose surface has been treated with vinyl silane coupling agent, propylene silane coupling agent or (meth)acrylate silane coupling agent. The dielectric loss of the spherical silica filler is less than 0.0014 at a frequency of 10 GHz. The average particle size D50 of the spherical silica filler is in the range of 0.5-5 μm.

6. The low-dielectric resin composition containing modified spirodifluorene resin as described in claim 1, characterized in that, The initiator is any one or more of azobisisobutyronitrile, azobis(2-isopropyl)butyronitrile, azobis(hexamethylene)-dicarbonitrile, benzoyl peroxide, dimethylbenzoyl peroxide, diisopropionyl peroxide, diisopropylbenzene peroxide, cyclohexanone peroxide, methyl ethyl ketone peroxide, dicyclohexyl peroxide, benzoic acid peroxide, tert-butyl peroxide, butylbenzoic acid peroxide, or tert-butylbenzoic acid peroxide.

7. A copper-clad laminate comprising the low-dielectric resin composition according to any one of claims 1-6, characterized in that, It is obtained by the following preparation method: The first step involves mixing the components of the low-dielectric resin composition containing modified spirodifluorene resin until the resin is completely dissolved, then applying the mixture as an adhesive onto a glass fiber cloth, and drying and curing it to allow the solvent to evaporate, thus obtaining a prepreg. The linear speed for applying the adhesive is 8-25 m / min; the drying and curing temperature is 110-230℃. The second step is to press the prepreg and copper foil together to obtain the copper-clad laminate. The pressing pressure is 70-600 psi, the temperature is 70-240℃, the vacuum degree is 0.02-0.1MPa, the curing time is 50-130min, and the pressing time is 70-200min.

8. A copper-clad laminate as described in claim 7, characterized in that, The fiberglass cloth is a Q-grade fiberglass cloth; The copper foil is 1 / 3 oz, Hoz, 1 oz, 2 oz, 3 oz, 4 oz or HPLV grade copper foil; The copper-clad laminate is a glass cloth-based copper-clad foil laminate with dimensions of 36×48, 37×49, 40×48, 40.5×48.5, 41×49, 42.5×48.5, and 43×49.

9. The application of a copper-clad laminate as described in any one of claims 7-8, characterized in that, The application is for manufacturing PCB circuit boards for semiconductor packaging.

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