A resin composition, a prepreg comprising the same, a copper clad plate, and a printed circuit board

Abstract

The present application provides a resin composition, a prepreg comprising the same, a copper clad plate and a printed circuit board. The resin composition is prepared from the following components in the following amounts: 30-50 parts of a maleimide compound, 20-40 parts of a polyphenyl ether resin, 10-20 parts of a crosslinking agent, 5-15 parts of a reactive phosphorus-containing flame retardant, and 60-150 parts of an inorganic filler, based on 100 parts of the total weight of the maleimide compound, the polyphenyl ether resin, the crosslinking agent and the reactive phosphorus-containing flame retardant. The resin composition provided by the present application achieves halogen-free flame retardation and low dielectric loss characteristics, and can better balance dielectric properties, low thermal expansion and high heat resistance, and has excellent comprehensive performance.

Description

Technical Field

[0001] This invention belongs to the field of printed circuit technology, specifically relating to a resin composition, a prepreg containing the same, a copper-clad laminate, and a printed circuit board. Background Technology

[0002] With the increasing performance and multifunctionality of electronic products, their electronic components are becoming more highly integrated and denser. The high frequency of signal transmission requires substrate materials to have low dielectric constant and low dielectric loss tangent to reduce the damping effect on electrical signals, thereby improving signal transmission speed and reducing signal transmission loss. With the increase in signal frequency and signal processing volume, not only are good dielectric properties required for the substrate, but also low thermal expansion characteristics are required to avoid reliability problems caused by inconsistent thermal expansion between PCB and chip.

[0003] Thermosetting polyphenylene ether (PPE) resin, as a low-polarity, crosslinkable resin, is widely used in copper-clad laminates for high-frequency applications due to its low dielectric constant and low dielectric loss factor. To improve the heat resistance reliability of PPE materials, maleimide compounds with high-temperature resistance are often introduced into the resin to increase its glass transition temperature and reduce thermal expansion, thereby increasing heat resistance. As the requirements for heat resistance reliability of high-frequency materials continue to increase, the amount of maleimide compounds used is also increasing. However, due to the relatively high polarity of maleimide compounds, their solubility in low-polarity solvents is poor, and there are compatibility issues with PPE resin and polyolefin resins. Resin precipitation can occur in the adhesive, thus affecting the crosslinking of the resin and the performance of the board. Improving the compatibility of maleimide compounds has become the key to the use of resin.

[0004] With the trend towards halogen-free electronic materials, low-polarity phosphorus-containing flame retardants are often introduced to balance low dielectric loss and halogen-free flame retardancy. However, these flame retardants are mostly dispersed in the resin system in the form of organic fillers, which leads to a decrease in resin flowability and adhesion, seriously affecting the processing and application reliability of PCBs. Therefore, the selection of suitable flame retardants is an issue that must be considered for halogen-free materials in high-frequency applications.

[0005] CN109096262A discloses a vinyl-modified maleimide compound, which uses 4-vinylbenzylamine to modify maleimide to obtain a styrene-terminated polyamine-imide resin. When used in conjunction with a crosslinking agent, this structure can improve the solubility of bismaleimide compounds, but the presence of NH bonds leads to a significant increase in the water absorption rate of the resin and poor dielectric properties.

[0006] TW202041591A discloses a composition of maleimide compounds containing a dihydroindene skeleton and diene polymers, but the disclosed resins in the diene polymers do not achieve flame retardant effects.

[0007] CN105936745A discloses a resin composition in which a p-dibenzyl type DOPO flame retardant is introduced into a system of olefin-terminated polyphenylene ether (PPO), styrene-butadiene resin and bismaleimide resin. However, as an organic filler, its addition will lead to a decrease in resin fluidity and a deterioration in adhesion.

[0008] Therefore, how to provide a resin composition that is compatible with maleimide compounds, can achieve halogen-free flame retardancy and low dielectric loss characteristics, and can well balance dielectric properties, low thermal expansion and high heat resistance, with excellent comprehensive performance, has become an urgent technical problem to be solved. Summary of the Invention

[0009] To address the shortcomings of existing technologies, the present invention aims to provide a resin composition, a prepreg containing the same, a copper-clad laminate, and a printed circuit board. By designing the specific composition of the resin composition, the present invention achieves halogen-free flame retardancy and low dielectric loss characteristics while resolving compatibility issues with maleimide compounds. Furthermore, it achieves a good balance between dielectric properties, low thermal expansion, and high heat resistance, resulting in excellent overall performance.

[0010] To achieve this objective, the present invention adopts the following technical solution:

[0011] In a first aspect, the present invention provides a resin composition, wherein the total weight of maleimide compound, polyphenylene ether resin, crosslinking agent and reactive phosphorus-containing flame retardant is 100 parts, and the raw materials for preparing the resin composition include the following components in parts by weight:

[0012]

[0013] The maleimide compound includes a maleimide compound having the following formula M-1;

[0014]

[0015] In formula M-1, n represents an integer from 2 to 10 (for example, it can be 2, 3, 4, 5, 6, 7, 8, 9 or 10);

[0016] In formula M-1, R1, R2, R3 and R4 each independently represent a C1-C5 alkyl group (e.g., methyl, ethyl, propyl, butyl or pentyl) or phenyl group, and the difference in the number of carbon atoms between R1 and R2 is ≥2 (e.g., 2, 3, 4 or 5), and the difference in the number of carbon atoms between R3 and R4 is ≥2 (e.g., 2, 3, 4 or 5).

[0017] In this invention, maleimide compounds are used to undergo a crosslinking reaction with low-polarity polyphenylene ether containing crosslinkable unsaturated double bonds, a crosslinking agent, and a reactive phosphorus-containing flame retardant. In addition, the self-polymerization of polyphenylene ether resin and crosslinking agent and their mutual reactions increase the rigid imide structure in the system and improve the resin crosslinking density. The resulting cured product has the characteristics of low dielectric constant, low dielectric loss tangent, high glass transition temperature (Tg), and low coefficient of thermal expansion (CTE).

[0018] Conventional maleimide compounds, due to their symmetrical structure and high polarity, are difficult to dissolve in low-polarity solvents such as toluene. They also exhibit poor compatibility with low-polarity polyphenylene ether or polyolefin resins, leading to phase separation after curing and affecting the overall performance of the cured resin. Research has found that using asymmetric substituents in the benzene ring structure of maleimide compounds (i.e., the difference in carbon number between R1 and R2 in formula M-1 is ≥2, and the difference in carbon number between R3 and R4 is ≥2), and having at least three or more asymmetric substituents in the benzene ring structure (i.e., n≥2 in formula M-1), can not only improve the solubility of maleimide compounds in non-polar solvents and enhance their compatibility with polyphenylene ether and polyolefin resins, but also, due to steric hindrance, the reaction temperature of the imine ring double bond with the unsaturated double bond of the olefin or polyphenylene ether is slightly higher, resulting in a slower reaction and a more synchronized overall reaction, thus preventing phase separation.

[0019] In this invention, a resin system comprising 100 parts by weight of maleimide compound, polyphenylene ether resin, crosslinking agent, and reactive phosphorus-containing flame retardant is used as a reference. The addition amount of maleimide compound is preferably 30-50 parts by weight. Less than 30 parts by weight results in insufficient heat resistance of the resin composition; more than 50 parts by weight leads to excessive water absorption, affecting its electrical properties. The addition amount of polyphenylene ether resin is preferably 20-40 parts by weight. Less than 20 parts by weight results in insufficient heat resistance of the resin composition; more than 40 parts by weight results in poor surface quality of the adhesive sheets. The crosslinking agent is mainly used to increase the crosslinking density of the copolymer, increase the compactness of the crosslinking network, and improve the glass transition temperature and heat resistance of the material. The addition amount of crosslinking agent is preferably 10-20 parts by weight. Less than 10 parts by weight results in low crosslinking degree of the resin composition and limited improvement in heat resistance; more than 20 parts by weight results in soft adhesive sheets that are prone to adhesion. The optimal addition amount of reactive phosphorus-containing flame retardant is 5-15 parts by weight. If the amount is less than 5 parts by weight, the flame retardant effect of the resin composition is poor; if the amount is more than 15 parts by weight, the glass transition temperature of the resin composition is low and the heat resistance is insufficient.

[0020] In this invention, the total weight of maleimide compound, polyphenylene ether resin, crosslinking agent and reactive phosphorus-containing flame retardant is 100 parts. The weight of maleimide compound can be 30 parts, 32 parts, 34 parts, 36 parts, 38 parts, 40 parts, 42 parts, 44 parts, 46 parts, 48 ​​parts or 50 parts, etc.

[0021] The polyphenylene ether resin can be present in parts by weight of 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, or 40, etc.

[0022] The weight percentage of the crosslinking agent can be 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 parts, etc.

[0023] The reactive phosphorus-containing flame retardant can be present in parts by weight of 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 parts, etc.

[0024] The inorganic filler can be in the following weight proportions: 60 parts, 70 parts, 80 parts, 90 parts, 100 parts, 110 parts, 120 parts, 130 parts, 140 parts, or 150 parts, etc.

[0025] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. The purpose and beneficial effects of the present invention can be better achieved and realized through the following preferred technical solutions.

[0026] As a preferred embodiment of the present invention, the maleimide compound further includes maleimide compounds having the following formulas M-2, M-3, and M-4;

[0027]

[0028] In Equations M-2 and M-3, n independently represents an integer from 1 to 10 (for example, it can be 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10);

[0029] As a preferred embodiment of the present invention, based on a mass percentage content of 100% for the maleimide compound, the mass percentage content of the maleimide compound of formula M-1 is ≥30%, for example, it can be 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, or 90%, etc. Preferably, the mass percentage content of the maleimide compound of formula M-1 is ≥60%. A higher mass percentage content of formula M-1 results in better system compatibility. In the present invention, based on a resin system with a total weight of 100 parts for the maleimide compound, polyphenylene ether resin, crosslinking agent, and reactive phosphorus-containing flame retardant, the addition amount of 30-50 parts by weight for the maleimide compound means that the total weight of all maleimide compounds is 30-50 parts by weight.

[0030] The maleimide compound of formula M-1 can be used alone or in combination with any one or at least two of the maleimide compounds of formula M-2, formula M-3 or formula M-4. Combination can compensate for the shortcomings of using a single maleimide compound. In order to avoid incompatibility problems, when the maleimide compound of formula M-1 is combined with the other three maleimide compounds, the mass percentage of the maleimide compound of formula M-1 should be 30% or more.

[0031] Maleimide compounds conforming to formula M-1 include, but are not limited to: DFE950A from Dongcai Technology Co., Ltd. (as shown in the following formula:

[0032]

[0033] Wherein, R1 and R3 are methyl, R2 and R4 are propyl, and n represents an integer from 2 to 10; maleimide compounds of formula M-2 include, but are not limited to: BMI-50P from KI Corporation and BMI2300 from Yamato Chemical; maleimide compounds of formula M-3 include, but are not limited to: MIR-3000 from a pharmaceutical company; maleimide compounds of formula M-4 include, but are not limited to: BMI-70 from KI Corporation and BMI-5100 from Yamato Chemical.

[0034] As a preferred embodiment of the present invention, the polyphenylene ether resin includes a polyphenylene ether resin having an unsaturated double bond structure.

[0035] Preferably, the polyphenylene ether resin has the structure shown in Formula I:

[0036]

[0037] Where n represents an integer from 1 to 15 (e.g., it can be 1, 2, 5, 7, 9, 10, 12, 14 or 15, etc.), and m represents an integer from 1 to 15 (e.g., it can be 1, 3, 4, 6, 8, 11, 13 or 15, etc.).

[0038] Y represents -C(CH3)2-, -CH(CH3)-, -CH2-, At least one of them;

[0039] X and Z each independently represent at least one of vinyl, styrene, propylene, vinylbenzoxy, methacryloxy, or allyl;

[0040] R1-R8 each independently represent hydrogen or methyl.

[0041] Preferably, the number average molecular weight of the polyphenylene ether resin is 1000-4000 g / mol, for example, it can be 1000 g / mol, 1500 g / mol, 2000 g / mol, 2500 g / mol, 3000 g / mol, 3500 g / mol or 4000 g / mol.

[0042] When the number average molecular weight of the polyphenylene ether resin is less than 1000 g / mol, the reaction rate of the polyphenylene ether resin is too fast and difficult to control, resulting in poor dielectric properties of the formed resin composition. When the number average molecular weight of the polyphenylene ether resin is greater than 4000 g / mol, the melt viscosity of the polyphenylene ether resin is too high, resulting in poor compatibility with other resins, and the prepared resin composition is prone to causing poor appearance.

[0043] In this invention, the test method for molecular weight (weight-average molecular weight, number-average molecular weight, etc.) is GB / T21863-2008, which is determined by gel permeation chromatography (GPC) based on polystyrene calibration.

[0044] As a preferred embodiment of the present invention, the crosslinking agent is selected from any one or a combination of at least two of the following: divinylbenzene, divinylbenzyl ether, 1,2-bis(vinylphenyl)ethane, triallyl isocyanurate, triallyl cyanurate, cyanate, 1,2,4-trivinylcyclohexane, tricyclodecanediethanol dimethacrylate, trimethylolpropane trimethacrylate, or polyolefin resins containing a butadiene structure. Typical but non-limiting combinations include, for example, a combination of divinylbenzene and divinylbenzyl ether, a combination of 1,2-bis(vinylphenyl)ethane, triallyl isocyanurate and triallyl cyanurate, a combination of 1,2,4-trivinylcyclohexane, tricyclodecanediol methyl methacrylate, trimethylolpropane trimethacrylate, and polyolefin resins containing a butadiene structure.

[0045] Preferably, the inorganic filler is selected from any one or a combination of at least two of the following: crystalline silica, synthetic silica, spherical silica, fused silica, hollow silica, chemically produced spherical silica, aluminum nitride, boron nitride, silicon nitride, silicon carbide, alumina, magnesium oxide, titanium dioxide, barium titanate, strontium titanate, talc, magnesium carbonate, barium sulfate, calcium carbonate, or aluminum borate.

[0046] With the halogen-free transformation of electronic materials, inactive phosphorus-containing additives are introduced into the resin system to achieve flame retardant effects. However, these additives have varying degrees of negative impact on the resin's flowability, adhesion, and heat resistance, thereby affecting the reliability of PCB processing and applications. On the other hand, reactive phosphorus-containing flame retardants are compatible with the resin system and can participate in molecular cross-linking reactions, thus avoiding the aforementioned drawbacks.

[0047] As a preferred embodiment of the present invention, the reactive phosphorus-containing flame retardant is a cyclophosphonitrile resin with unsaturated double bonds.

[0048] Preferably, the reactive phosphorus-containing flame retardant includes allyl cyclotriphosphazene and / or styryl cyclophosphazene.

[0049] Preferably, the styrene-based cyclophosphonitrile has the following structural formula:

[0050]

[0051] Where n represents 3 or 4, and the ratio of l to m is 1:1 to 3:1 (for example, it can be 1:1, 1.2:1, 1.4:1, 1.6:1, 1.8:1, 2:1, 2.2:1, 2.4:1, 2.6:1, 2.8:1 or 3:1, etc.), and the ratio of l to m is more preferably 3:1, for example: FP-700TP (Fushimi Pharmaceutical Co., Ltd., Japan).

[0052] As a preferred embodiment of the present invention, the resin composition further includes additives.

[0053] It should be noted that this invention does not impose any special restrictions on the specific amount of additives used; they can be added according to the type and requirements of the additives.

[0054] Preferably, the additive includes any one or a combination of at least two of the following: surfactants, emulsifiers, toughening agents, viscosity modifiers, pigments, and curing accelerators. Typical but non-limiting combinations include: combinations of emulsifiers and surfactants, combinations of toughening agents, curing accelerators, and pigments, and combinations of surfactants, emulsifiers, toughening agents, viscosity modifiers, pigments, and curing accelerators.

[0055] To promote the reaction of the resin composition, increase the crosslinking density, and improve the glass transition temperature and heat resistance, a curing accelerator can be used to further accelerate the reaction.

[0056] The hardening accelerator is preferably an organic peroxide radical initiator, further selected from di-tert-butyl peroxide, dilauroyl peroxide, benzoyl peroxide, cumyl peroxyneodecanate, tert-butyl peroxyneodecanate, tert-butyl peroxypentanoate, tert-butyl peroxyisobutyrate, tert-butyl peroxy-3,5,5-trimethylhexanoate, tert-butyl peroxyacetate, tert-butyl peroxybenzoate, 1,1-di-tert-butyl peroxy-3,5,5-trimethylcyclohexane, 1,1-di-tert-butyl peroxycyclohexane, 2,2-di(tert-butylperoxy)butane, bis(4-tert-butylcyclohexyl) peroxydicarbonate, and hexadecyl peroxydicarbonate. The following are any one or a combination of at least two of the following: tetradecyl peroxide, dipentylhexyl peroxide, dicumylbenzene peroxide, bis(tert-butylperoxyisopropyl)benzene, 2,5-dimethyl-2,5-di-tert-butylperoxyhexane, 2,5-dimethyl-2,5-di-tert-butylperoxyhexyne, dicumylbenzene hydrogen peroxide, cumylbenzene hydrogen peroxide, pentyl hydrogen peroxide, tert-butyl hydrogen peroxide, tert-butyl cumyl peroxide, dicumylbenzene hydrogen peroxide, tert-butyl percarbonate-2-ethylhexanoate, tert-butyl percarbonate-2-ethylhexyl ester, n-butyl 4,4-di(tert-butylperoxy)valerate, methyl ethyl ketone peroxide, or cyclohexane peroxide.

[0057] The resin composition also includes a solvent.

[0058] In this invention, there are no special limitations on the specific selection of solvents, but exemplary solvents include, but are not limited to, ketones such as acetone, butanone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and mesitylene; esters such as ethoxyethyl acetate and ethyl acetate; and nitrogen-containing solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone. The above solvents can be used alone or in mixtures of two or more. Preferably, aromatic hydrocarbon solvents such as toluene, xylene, and mesitylene are mixed with ketone fluxes such as acetone, butanone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone.

[0059] The amount of solvent used can be selected by those skilled in the art based on their experience, so that the resulting resin solution reaches a suitable viscosity for use.

[0060] During the process of dissolving or dispersing the resin composition as described above in a solvent, an emulsifier can be added. By dispersing through the emulsifier, powder fillers and the like can be evenly dispersed in the adhesive solution.

[0061] In a second aspect, the present invention provides a prepreg comprising a reinforcing material and a resin composition as described in the first aspect.

[0062] Preferably, the resin composition is attached to the reinforcing material by impregnation and drying.

[0063] Thirdly, the present invention provides a copper-clad laminate comprising at least one prepreg as described in the second aspect.

[0064] Fourthly, the present invention provides a printed circuit board comprising at least one copper-clad laminate as described in the third aspect.

[0065] Compared with the prior art, the present invention has the following beneficial effects:

[0066] This invention designs the specific composition of the resin composition and further utilizes the synergistic effect of a maleimide compound with a specific structural formula, polyphenylene ether resin, crosslinking agent, and reactive phosphorus-containing flame retardant. Simultaneously, it controls the amounts of the maleimide compound, polyphenylene ether resin, crosslinking agent, and reactive phosphorus-containing flame retardant within a specific range. The resulting resin composition exhibits halogen-free flame retardancy and low dielectric loss characteristics, and can effectively balance dielectric properties, low thermal expansion, and high heat resistance, resulting in excellent overall performance. Detailed Implementation

[0067] To facilitate understanding of the present invention, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of the invention.

[0068] The component codes and their corresponding component names in the specific embodiments of this invention are as follows:

[0069] (A-1) Maleimide compound: DFE950A (Sichuan Dongcai Technology Co., Ltd.);

[0070] (A-2) Maleimide compound: BMI2300 (Yamato Chemical Co., Ltd.);

[0071] (A-3) Maleimide compound: MIR-3000 (Nippon Kayaku Chemical Co., Ltd.);

[0072] (A-4) Maleimide compound: BMI-70 (KI Company);

[0073] (B-1) Methacrylamide-terminated polyphenylene ether resin: SA9000 (Sabic Company);

[0074] (B-2) Styrene-terminated polyphenylene ether resin: OPE-2st 2200 (Mitsubishi Chemical Corporation);

[0075] (C-1) Triallyl isocyanurate: TAIC (Hunan Fangruida Technology Co., Ltd.);

[0076] (C-2) Tricyclodecanediethanol dimethacrylate: DCP (Shinnakamura Chemical Co., Ltd.);

[0077] (D-1) Allyl-containing phosphononitrile resin: SPV-100 (Otsuka Chemical Co., Ltd.);

[0078] (D-2) Styrene-containing phosphononitrile resin: FP-700TP (Fushimi Pharmaceutical Co., Ltd.);

[0079] (D-3) Non-reactive phosphazene: SPB-100 (Otsuka Chemical Co., Ltd.);

[0080] (E) Curing accelerator: Perkadox BC-FF (AkzoNobel);

[0081] (F) Filler: Fused silica (Lianrui New Materials Co., Ltd.);

[0082] (G) Fiberglass cloth: 2116E-Fiberglass cloth (Shanghai Honghe Electronic Materials Co., Ltd.);

[0083] (H) Electrolytic copper foil: Mitsui Metals Co., Ltd.

[0084] Examples 1-8 and Comparative Examples 1-6

[0085] Examples 1-8 and Comparative Examples 1-6 respectively provide a resin composition and a copper-clad laminate. The components of the resin composition and their amounts (by weight) are shown in Table 1 and Table 2 below:

[0086] Table 1

[0087]

[0088]

[0089] Table 2

[0090]

[0091]

[0092] The above-mentioned method for preparing copper-clad laminate includes the following steps:

[0093] (1) Mixing glue

[0094] Add the ingredients according to the proportions of each component in the table above, add 60 parts toluene and 30 parts methyl ethyl ketone, and mechanically stir for 4 hours to dissolve and mature, thus preparing the adhesive.

[0095] (2) Prepreg preparation

[0096] The 2116E-glass fiber cloth is pre-impregnated in the adhesive obtained in step (1), and some of the liquid resin is removed by the roller clamping shaft so that the resin on the glass fiber cloth is controlled at about 65%. Then the glass fiber cloth is dried in an oven at a temperature of 145°C for 4.5 minutes to obtain the prepreg.

[0097] (3) Copper Clad Laminate Preparation

[0098] Prepare two 18μm thick electrolytic copper foils. Stack five prepregs obtained in step (2) with all four sides neatly aligned. Cover each of the stacked sheets with a prepared electrolytic copper foil on both the top and bottom surfaces. Place the stacked sheets into a laminator and laminate them under the following conditions:

[0099] Heat the laminator to 90°C and apply full pressure, which is 30 kgf / cm². 2 Continue heating until it reaches 120°C. Control the material temperature rise rate at 2°C / min until it reaches 220°C. Hold the temperature for 120 minutes to solidify and obtain the copper-clad laminate.

[0100] Performance testing

[0101] The copper-clad laminates provided in Examples 1-8 and Comparative Examples 1-6 were tested according to the following requirements:

[0102] (1) Glass transition temperature of the plate (Tg, °C): The dynamic thermomechanical analysis (DMA) method was used to determine the glass transition temperature (Tg) according to the DMA method specified in IPC-TM-6502.4.24.4.

[0103] (2) Dielectric constant (Dk) and dielectric loss tangent (Df): The dielectric constant (Dk) and dielectric loss tangent (Df) were measured at 10 GHz using the split dielectric pillar resonator method (SPDR) as specified in IPC-TM-650 2.5.5.13.

[0104] (3) Z-axis CTE and CTE after Tg: The thermomechanical analysis (TMA) method is used to test according to the method specified in IPC-TM-650 2.4.24. The Z-axis CTE value is the thermal expansion coefficient from 50 to 260℃, and the CTE after Tg is the thermal expansion coefficient from Tg to 260℃.

[0105] (4) Flame retardancy: Tested and classified according to the material flammability method specified in UL-94.

[0106] The performance test results are shown in Table 1 and Table 2 above.

[0107] As can be seen from the above, by designing the specific composition of the resin composition in this invention, and further through the synergistic effect of maleimide compounds with specific structural formulas, polyphenylene ether resin, crosslinking agents, and reactive phosphorus-containing flame retardants, while controlling the amounts of maleimide compounds, polyphenylene ether resin, crosslinking agents, and reactive phosphorus-containing flame retardants within a specific range, the prepared resin composition exhibits halogen-free flame retardancy and low dielectric loss characteristics. It also achieves a good balance between dielectric properties, low thermal expansion, and high heat resistance, resulting in excellent overall performance. Its flame retardancy rating is V-0, dielectric constant Dk ≤ 3.99 (specifically 3.82–3.99), dielectric loss tangent ≤ 0.0046 (specifically 0.0043–0.0046), Z-axis CTE ≤ 1.42% (specifically 0.93%–1.42%), and CTE after Tg ≤ 120 ppm / ℃ (specifically 84–120 ppm / ℃).

[0108] As can be seen from Examples 1-8 and Comparative Examples 1-2, by controlling the amounts of maleimide compound, polyphenylene ether resin, crosslinking agent and reactive phosphorus-containing flame retardant within a specific range, the thermal expansion properties of the resin composition can be further reduced and its overall performance improved.

[0109] By comparing Example 2 with Comparative Example 3, and Example 1 with Comparative Example 5, it can be seen that if the amount of maleimide compound in the resin composition is too large (Comparative Example 3), the prepared resin composition has poor dielectric properties, a poor glass transition temperature, and high thermal expansion. If the amount of maleimide compound in the resin composition is too small (Comparative Example 5), the prepared resin composition has poor overall performance, especially poor dielectric properties.

[0110] As can be seen from Example 4 and Comparative Example 4, if the amount of filler in the resin composition is too large (Comparative Example 4), the dielectric properties of the prepared resin composition are poor.

[0111] As can be seen from Examples 3 and 6, if symmetrical maleimide compounds are used to prepare the resin composition (Comparative Example 6), the components of the prepared resin composition are incompatible and cannot be used. As can be seen from Examples 3 and 8, although the benzene ring substituents in the maleimide compound used in Comparative Example 8 are asymmetrical, the difference in the number of carbon atoms of the substituents is only 1, and it contains only 2 benzene ring groups with asymmetrical substituents. Its solubility in solvent is poor. When added to 50 parts by weight, the prepared resin composition also has incompatibility problems and cannot be used.

[0112] As can be seen from Example 1 and Comparative Example 7, if non-reactive phosphazene is selected as the flame retardant, the glass transition temperature of the product decreases significantly and the coefficient of thermal expansion increases.

[0113] In summary, this invention utilizes the synergistic effect of maleimide compounds with specific structural formulas, polyphenylene ether resin, crosslinking agents, and reactive phosphorus-containing flame retardants, while simultaneously controlling the amounts of maleimide compounds, polyphenylene ether resin, crosslinking agents, and reactive phosphorus-containing flame retardants within a specific range. The resulting resin composition exhibits halogen-free flame retardancy and low dielectric loss characteristics, and also achieves a good balance between dielectric properties, low thermal expansion, and high heat resistance, resulting in excellent overall performance.

[0114] The applicant declares that the detailed process flow of this invention is illustrated by the above embodiments, but this invention is not limited to the above detailed process flow, that is, it does not mean that this invention must rely on the above detailed process flow to be implemented. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of raw materials for the product of this invention, addition of auxiliary components, and selection of specific methods, etc., all fall within the protection scope and disclosure scope of this invention.

Claims

1. A resin composition, characterized in that, Based on a total weight of 100 parts of maleimide compound, polyphenylene ether resin, crosslinking agent, and reactive phosphorus-containing flame retardant, the raw materials for preparing the resin composition include the following components in parts by weight: 30-50 parts of maleimide compound 20-40 parts of polyphenylene ether resin 10-20 parts of crosslinking agent 5-15 parts of reactive phosphorus-containing flame retardant 60-150 parts of inorganic filler; The maleimide compound includes a maleimide compound having the following formula M-1; Formula M-1; In formula M-1, n represents an integer from 2 to 10; In formula M-1, R1, R2, R3 and R4 each independently represent C1-C5 alkyl or phenyl groups, and the difference in the number of carbon atoms between R1 and R2 is ≥2, and the difference in the number of carbon atoms between R3 and R4 is ≥2.

2. The resin composition according to claim 1, characterized in that, The maleimide compounds also include maleimide compounds having the following formulas M-2, M-3, and M-4; Formula M-2; M-3; M-4; In equations M-2 and M-3, n independently represents an integer from 1 to 10.

3. The resin composition according to claim 1, characterized in that, Based on the maleimide compound having a mass percentage content of 100%, the maleimide compound of formula M-1 has a mass percentage content of ≥30%.

4. The resin composition according to claim 3, characterized in that, Based on the maleimide compound having a mass percentage content of 100%, the maleimide compound of formula M-1 has a mass percentage content of ≥60%.

5. The resin composition according to claim 1, characterized in that, The polyphenylene ether resin includes a polyphenylene ether resin having an unsaturated double bond structure.

6. The resin composition according to claim 5, characterized in that, The polyphenylene ether resin has the structure shown in Formula I: Equation I; Where n represents an integer from 1 to 15, and m represents an integer from 1 to 15; Y represents -C(CH3)2-, -CH(CH3)-, -CH2-, , At least one of them; X and Z each independently represent at least one of vinyl, styrene, propylene, vinylbenzoxy, methacryloxy, or allyl; R1-R8 each independently represent hydrogen or methyl.

7. The resin composition according to claim 1, characterized in that, The number-average molecular weight of the polyphenylene ether resin is 1000-4000 g / mol.

8. The resin composition according to claim 1, characterized in that, The crosslinking agent is selected from any one or a combination of at least two of the following: divinylbenzene, divinylbenzyl ether, 1,2-bis(vinylphenyl)ethane, triallyl isocyanurate, triallyl cyanurate, cyanate, 1,2,4-trivinylcyclohexane, tricyclodecanediethanol dimethacrylate, trimethylolpropane trimethacrylate, or polyolefin resins containing a butadiene structure.

9. The resin composition according to claim 1, characterized in that, The inorganic filler is selected from any one or a combination of at least two of the following: crystalline silicon dioxide, synthetic silicon dioxide, spherical silicon dioxide, fused silicon dioxide, hollow silicon dioxide, chemically produced spherical silicon, aluminum nitride, boron nitride, silicon nitride, silicon carbide, aluminum oxide, magnesium oxide, titanium dioxide, barium titanate, strontium titanate, talc, magnesium carbonate, barium sulfate, calcium carbonate, or aluminum borate.

10. The resin composition according to claim 1, characterized in that, The reactive phosphorus-containing flame retardant is a cyclophosphonitrile resin with unsaturated double bonds.

11. The resin composition according to claim 10, characterized in that, The reactive phosphorus-containing flame retardants include allyl cyclotriphosphazene and / or styryl cyclophosphazene.

12. The resin composition according to claim 11, characterized in that, The structural formula of the styrene-based cyclophosphonitrile is as follows: Where n represents 3 or 4, and the ratio of l to m is 1:1 to 3:

1.

13. The resin composition according to claim 12, characterized in that, The ratio of l to m is 3:

1.

14. The resin composition according to claim 1, characterized in that, The resin composition also includes additives.

15. The resin composition according to claim 14, characterized in that, The additives include any one or a combination of at least two of the following: surfactants, toughening agents, hardening accelerators, pigments, or viscosity modifiers.

16. A prepreg, characterized in that, The prepreg includes reinforcing materials and the resin composition as described in any one of claims 1-15.

17. The prepreg according to claim 16, characterized in that, The resin composition is attached to the reinforcing material by impregnation and drying.

18. A copper-clad laminate, characterized in that, The copper-clad laminate includes at least one prepreg as described in claim 16 or 17.

19. A printed circuit board, characterized in that, The printed circuit board includes at least one copper-clad laminate as described in claim 18.

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