Resin composition, prepreg, circuit board and printed circuit board

Abstract

The invention relates to a resin composition, a prepreg, a circuit substrate and a printed circuit board, the resin composition comprises low-chroma resin, an epoxy compound, a filler and a curing agent, the Gardner chroma of the low-chroma resin is less than or equal to 3, the content of carbon-carbon double bonds is less than or equal to 10%, and the epoxy compound is an epoxy compound. The low-chroma resin comprises a first resin with the weight-average molecular weight of 3000-4000 and a second resin with the weight-average molecular weight of lt; 2000 of a second resin; the epoxy compound comprises an aliphatic ring, and the number of benzene rings is less than or equal to 3; the filler at least comprises whiteness gt; and 90% of a first filler. The circuit substrate prepared from the resin composition has excellent initial state reflectivity, excellent yellowing resistance and heat resistance, and can meet the requirements of harsh use environments.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic industry, and in particular to a resin composition, a prepreg, a circuit substrate and a printed circuit board. Background Art

[0002] In some applications, circuit substrates require not only high initial reflectivity but also the ability to maintain that reflectivity over time. However, sustained high thermal radiation in the operating environment can cause circuit substrates to age, resulting in severe yellowing of the surface and shortening their service life. Therefore, facing the increasingly demanding operating environments of circuit substrates, there is an urgent need to develop circuit substrates with excellent initial reflectivity, yellowing resistance, and heat resistance. Summary of the Invention

[0003] Based on this, it is necessary to provide a resin composition, a prepreg, a circuit substrate and a printed circuit board to address the above problems. The circuit substrate provided by the present invention has excellent initial reflectivity, as well as excellent yellowing resistance and heat resistance.

[0004] A resin composition comprises a low-chroma resin, an epoxy compound, a filler, and a curing agent; wherein the low-chroma resin has a Gardner chroma of ≤3 and a carbon-carbon double bond content of ≤10%, the low-chroma resin comprises a first resin with a weight-average molecular weight of 3000-4000 and a second resin with a weight-average molecular weight of <2000; the epoxy compound comprises an aliphatic ring, and the number of benzene rings is ≤3; and the filler comprises at least a first filler with a whiteness of >90%.

[0005] In one embodiment, the weight ratio of the first resin to the second resin is 1:1 to 3:1.

[0006] In one embodiment, the first resin and the second resin are each independently selected from at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, bisphenol AD epoxy resin, hydrogenated bisphenol A epoxy resin, acrylic resin, and bisphenol A polyester resin.

[0007] In one embodiment, the epoxy compound is selected from at least one of the compounds represented by formula (1), formula (2) and formula (3).

[0008] Wherein, 1≤m≤20, 1≤n≤20, X is selected from a C1-C5 alkyl group or an ester group, R1-R7 are each independently selected from -H, an epoxy group or a C1-C6 alkyl group, and at least one of R1 and R2 is selected from an epoxy group, at least one of R3, R4 and R5 is selected from an epoxy group, and at least one of R6 and R7 is selected from an epoxy group.

[0009] In one embodiment, the weight of the first filler accounts for ≥40% of the weight of the resin composition.

[0010] In one embodiment, the filler further includes a second filler, and the second filler is selected from at least one of alumina, boron nitride, silicon carbide, aluminum nitride, silicon dioxide, boehmite, talc, and calcium carbonate.

[0011] In one embodiment, the curing agent includes at least one of an anhydride curing agent or an active ester curing agent.

[0012] In one embodiment, the curing agent includes at least an anhydride curing agent and an amine curing agent, and the ratio of the number of anhydride groups in the anhydride curing agent to the number of active hydrogen groups in the amine curing agent is 1:0 to 1:5.

[0013] In one embodiment, the resin composition includes the following components in parts by weight: based on 100 parts by weight of the total of the low-color resin and the epoxy compound, the amount of the filler is 100 parts by weight to 250 parts by weight, and the amount of the curing agent is 80 parts by weight to 120 parts by weight, wherein the weight ratio of the low-color resin to the epoxy compound is 1:3 to 3:1.

[0014] In one embodiment, the resin composition further includes an auxiliary resin, and the Tg of the auxiliary resin is ≥ 180°C.

[0015] In one embodiment, the auxiliary resin has a Gardner color of ≤10.

[0016] In one embodiment, the auxiliary resin is selected from at least one of bisphenol A novolac epoxy resin, o-cresol novolac epoxy resin, hydantoin epoxy resin, multifunctional epoxy resin and biphenyl epoxy resin.

[0017] In one embodiment, the total weight of the low-color resin, the auxiliary resin, and the epoxy compound is 100 parts, wherein the weight ratio of the low-color resin to the auxiliary resin is 1:2 to 3:1.

[0018] A prepreg made from the resin composition described above.

[0019] A circuit substrate made of the prepreg described above.

[0020] A printed circuit board made of the circuit substrate described above.

[0021] The resin composition provided by the present invention, through the synergistic effect between the low-chroma resin, the epoxy compound, the first filler, and the curing agent, improves the dispersion effect of the first filler, resulting in an excellent initial reflectivity of the circuit substrate. Furthermore, the two resins with specific molecular weights and the epoxy compound with a specific structure can achieve a certain crosslinking density while reducing problems such as thermal oxidation, thereby improving the heat resistance and yellowing resistance of the circuit substrate and ensuring its stable high reflectivity. Therefore, the circuit substrate prepared using the resin composition provided by the present invention can meet the requirements of harsh operating environments and has high market application potential. DETAILED DESCRIPTION

[0022] To facilitate understanding of the present invention, the present invention will be described in more detail below. However, it should be understood that the present invention can be implemented in many different forms and is not limited to the embodiments or examples described herein. On the contrary, the purpose of providing these embodiments or examples is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the technical field of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments or embodiments and are not intended to limit the present invention. The optional scope of the term "and / or" used herein includes any one of two or more related listed items, and also includes any and all combinations of related listed items, including any two related listed items, any more related listed items, or the combination of all related listed items.

[0024] The resin composition provided by the present invention comprises a low-chroma resin, an epoxy compound, a filler and a curing agent; wherein the low-chroma resin has a Gardner chroma of ≤3 and a carbon-carbon double bond content of ≤10%, the low-chroma resin comprises a first resin with a weight-average molecular weight of 3000-4000 and a second resin with a weight-average molecular weight of <2000; the epoxy compound comprises an aliphatic ring, and the number of benzene rings is ≤3; and the filler comprises at least a first filler with a whiteness of >90%.

[0025] The above-mentioned resin composition, through the synergistic effect between the resin, epoxy compound, first filler and curing agent, on the one hand, improves the dispersion effect of the first filler, so that the circuit substrate has excellent initial reflectivity; on the other hand, the two resins with specific molecular weights and the epoxy compound with a specific structure can achieve a certain cross-linking density while reducing problems such as thermal oxidation, thereby improving the heat resistance and yellowing resistance of the circuit substrate and ensuring its stable high reflectivity. That is, the reflectivity of the circuit substrate remains high under harsh usage environments and changes little compared to the initial reflectivity.

[0026] Therefore, the circuit substrate prepared by using the resin composition provided by the present invention can meet the requirements of harsh usage environments and has high market application potential.

[0027] It should be noted that the Gardner chromaticity of the first resin and the second resin is also independently ≤3, and the content of carbon-carbon double bonds in the molecular chains of the first resin and the second resin is also independently ≤10%; the content of carbon-carbon double bonds is expressed as the ratio of carbon-carbon double bonds in the resin structure to the total mass of the entire resin structure; the yellowing resistance of the circuit substrate is improved by adjusting the content of carbon-carbon double bonds in the first resin and the second resin, so that it has a stable high reflectivity.

[0028] The whiteness of the first filler is measured using a whiteness tester, with the blue light whiteness R457 being the whiteness of the first filler.

[0029] In order to further control the crosslinking density of the resin composition and improve the dispersibility of the first filler, thereby improving the initial reflectivity and heat resistance of the circuit substrate, the weight ratio of the first resin to the second resin is preferably 1:1 to 3:1.

[0030] In one embodiment, the low-chroma resin is selected from at least one of epoxy resin, acrylic resin and polyester resin.

[0031] Specifically, the first resin and the second resin are each independently selected from at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, bisphenol AD epoxy resin, hydrogenated bisphenol A epoxy resin, acrylic resin, and bisphenol A polyester resin.

[0032] In one embodiment, the epoxy compound is selected from at least one of the compounds represented by formula (1), formula (2) and formula (3).

[0033] Wherein, 1≤m≤20, 1≤n≤20, X is selected from a C1-C5 alkyl group or an ester group, R1-R7 are each independently selected from -H, an epoxy group, or a C1-C6 alkyl group, at least one of R1 and R2 is selected from an epoxy group, at least one of R3, R4, and R5 is selected from an epoxy group, and at least one of R6 and R7 is selected from an epoxy group. This epoxy compound is relatively transparent, and its cured product has a high crosslink density, resulting in high yellowing resistance and heat resistance of the circuit substrate, ensuring stable high reflectivity.

[0034] Further preferably, in formula (1), 3≤m≤10, X is selected from a C1-C5 alkyl group or an ester group, R1 and R2 are both selected from an epoxy group, in formula (2), 3≤n≤10, R4 is selected from an epoxy group, R3 and R5 are each independently selected from -H, an epoxy group or a C1-C6 alkyl group, and in formula (3), R6 and R7 are both selected from an epoxy group.

[0035] In one embodiment, the weight of the first filler accounts for ≥40% of the weight of the resin composition, thereby effectively ensuring the initial reflectivity and yellowing resistance of the circuit substrate.

[0036] Preferably, the first filler is selected from at least one of titanium dioxide, aluminum hydroxide and aluminum silicate.

[0037] In one embodiment, the filler further includes a second filler selected from at least one of aluminum oxide, boron nitride, silicon carbide, aluminum nitride, silica, boehmite, talc, and calcium carbonate. Aluminum oxide, boron nitride, silicon carbide, and aluminum nitride can serve as thermally conductive fillers to improve the thermal conductivity and heat dissipation of the circuit substrate, thereby reducing heat accumulation in the operating environment and improving the yellowing resistance of the circuit substrate. Silica, boehmite, talc, and calcium carbonate can serve as reinforcing fillers, and those skilled in the art can select the filler as needed, and the present invention is not limited thereto.

[0038] In one embodiment, the curing agent includes at least one of an anhydride curing agent or an active ester curing agent.

[0039] The acid anhydride curing agent is selected from at least one of phthalic anhydride, pyromellitic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic anhydride, nadic anhydride, styrene maleic anhydride and maleic anhydride, and the active ester curing agent is selected from at least one of phenyl acetate, phenyl methacrylate and bisphenol A type active ester.

[0040] Preferably, the curing agent includes at least an acid anhydride curing agent and an amine curing agent, and the amine curing agent is selected from at least one of diaminodiphenyl sulfone, diaminodiphenylmethane, diaminodiphenyl ether, meta-xylenediamine, dicyandiamide, and para-diphenylamine. The amine curing agent has strong reactivity and its cured product has good heat resistance, thereby further improving the heat resistance of the circuit substrate.

[0041] More preferably, the ratio of the number of anhydride groups in the anhydride curing agent to the number of active hydrogens in the amine curing agent is 1:0 to 1:5, so as to improve the heat resistance of the circuit substrate while ensuring high initial reflectivity and yellowing resistance of the circuit substrate.

[0042] More preferably, the ratio of the number of anhydride groups in the anhydride curing agent to the number of active hydrogen groups in the amine curing agent is 1:0.05 to 1:1.

[0043] In one embodiment, the resin composition includes the following components in parts by weight: based on 100 parts by weight of the total of the low-color resin and the epoxy compound, the amount of the filler is 100 to 250 parts by weight, and the amount of the curing agent is 80 to 120 parts by weight, wherein the weight ratio of the low-color resin to the epoxy compound is 1:3 to 3:1.

[0044] In one embodiment, the resin composition further includes an auxiliary resin, and the auxiliary resin has a Tg of ≥ 180° C., thereby further improving the heat resistance of the circuit substrate.

[0045] In order to ensure high initial reflectivity and yellowing resistance of the circuit substrate, the Gardner color of the auxiliary resin is preferably ≤10.

[0046] Preferably, the auxiliary resin is selected from bisphenol A novolac epoxy resin, o-cresol novolac epoxy resin, hydantoin epoxy resin, multifunctional epoxy resin and biphenyl epoxy resin.

[0047] In addition, the said multifunctional epoxy resin means an epoxy resin containing multiple epoxy groups.

[0048] In one embodiment, the resin composition includes the following components in parts by weight: based on 100 parts by weight of the total of the low-color resin, the auxiliary resin and the epoxy compound, the amount of the filler is 100 to 250 parts by weight, and the amount of the curing agent is 80 to 120 parts by weight, wherein the weight ratio of the low-color resin to the auxiliary resin is 1:2 to 3:1.

[0049] In one embodiment, the resin composition further comprises a coupling agent.

[0050] Specifically, based on 100 parts by weight of the total weight of the low-chroma resin and the epoxy compound, the amount of the coupling agent is 4 to 5 parts by weight.

[0051] In one embodiment, the resin composition further comprises an antioxidant, thereby improving the thermal stability of the resin composition and further improving the yellowing resistance of the circuit substrate.

[0052] Specifically, based on 100 parts by weight of the total of the low-chroma resin and the epoxy compound, the amount of the antioxidant is 1 to 2 parts by weight.

[0053] In one embodiment, the resin composition further comprises a solvent, and the solvent is selected from at least one of acetone, butanone, propylene glycol methyl ether, and propylene glycol methyl ether acetate.

[0054] The present invention also provides a prepreg, which is made of the resin composition as described above. The cross-linking density of the resin composition in the prepreg is high, so that the prepreg has high heat resistance.

[0055] The present invention does not limit the specific preparation method of the prepreg from the resin composition. Preferably, the prepreg is obtained by impregnating or coating a reinforcing material with the resin composition and drying it. The reinforcing material is preferably at least one of glass fiber cloth, aramid cloth or carbon fiber cloth.

[0056] The present invention also provides a circuit substrate made using the aforementioned prepreg, comprising an insulating layer and a conductive layer disposed on at least one surface of the insulating layer. The insulating layer is formed by pressing one or more laminated prepregs as described above. The conductive layer can be a conductive material such as copper foil or aluminum foil, although this is not a limitation of the present invention. Copper foil is preferred. The circuit substrate exhibits excellent initial reflectivity, yellowing resistance, and heat resistance, meeting the requirements of demanding operating environments.

[0057] The present invention also provides a printed circuit board made of the circuit substrate described above, which can meet the requirements of harsh usage environments.

[0058] Specifically, the printed circuit board is made from the circuit substrate through processes such as drilling, hole filling, micro-etching, pre-preg, activation, acceleration, chemical copper and copper thickening.

[0059] Hereinafter, the resin composition, prepreg and circuit substrate will be further described through the following specific examples.

[0060] Example 1

[0061] 20 parts by weight of low molecular weight bisphenol F epoxy resin (color = 3, molecular weight = 370, carbon-carbon double bond content = 0), 20 parts by weight of high molecular weight bisphenol A epoxy resin (color = 1, molecular weight = 3600, carbon-carbon double bond content = 0), 30 parts by weight of epoxy compound (structural formula is formula 2-1), 30 parts by weight of bisphenol A novolac epoxy resin (Tg = 185°C, color = 7), 50 parts by weight of methyltetrahydrophthalic anhydride curing agent, 50 parts by weight of methylhexahydrophthalic anhydride curing agent, 2 parts by weight of dicyandiamide (the number of anhydride groups in the anhydride curing agent is equal to the number of active hydrogen groups in the amine curing agent) The resin composition was impregnated on 2116 electronic-grade glass fiber cloth, and heated in an oven at 160° C. for 3 minutes to obtain a prepreg. The prepreg was then stacked with two layers of electrolytic copper foil on the top and bottom, and two layers of prepreg were placed in the middle. The layers were cured and pressed in a high-temperature press at 200° C. for 4 hours to obtain a circuit substrate.

[0062] Example 2

[0063] 10 parts by weight of a low molecular weight acrylic resin (color = 1, molecular weight = 380, carbon-carbon double bond content = 0), 30 parts by weight of a high molecular weight bisphenol A epoxy resin (color = 1, molecular weight = 3300, carbon-carbon double bond content = 0), 30 parts by weight of an epoxy compound (structural formula is formula 2-1), 30 parts by weight of a bisphenol A novolac epoxy resin (Tg = 185°C, color = 7), 30 parts by weight of a methyltetrahydrophthalic anhydride curing agent, 50 parts by weight of a methylhexahydrophthalic anhydride curing agent, 2 parts by weight of dicyandiamide (the ratio of the number of anhydride groups in the anhydride curing agent to the number of active hydrogens in the amine curing agent) were prepared. =1:0.20), 100 parts by weight of acetone, 40 parts by weight of propylene glycol methyl ether, and 1 part by weight of a silane coupling agent were added, dissolved and mixed uniformly, and then 180 parts by weight of aluminum hydroxide (whiteness = 97%) was added, and the mixture was dispersed with high-speed stirring and stirred for 120 minutes to prepare a resin composition; the resin composition was impregnated on 2116 type electronic grade glass fiber cloth, and heated in an oven at 160° C. for 3 minutes to obtain a prepreg, and then two layers of prepreg were stacked in the middle with a layer of electrolytic copper foil on the top and bottom, and cured and pressed in a high-temperature press at 200° C. for 4 hours to obtain a circuit substrate.

[0064] Example 3

[0065] 20 parts by weight of low molecular weight bisphenol F epoxy resin (color = 3, molecular weight = 370, carbon-carbon double bond content = 0), 20 parts by weight of high molecular weight bisphenol A epoxy resin (color = 1, molecular weight = 3600, carbon-carbon double bond content = 0), 30 parts by weight of epoxy compound (structural formula is formula 2-1), 30 parts by weight of tetrafunctional epoxy resin (Tg = 190°C, color = 4), 50 parts by weight of methyltetrahydrophthalic anhydride curing agent, 50 parts by weight of methylhexahydrophthalic anhydride curing agent, 10 parts by weight of dicyandiamide (the number of anhydride groups in the anhydride curing agent is equal to the number of active hydrogens in the amine curing agent) The invention relates to a method for preparing a resin composition comprising the steps of: impregnating a 2116-type electronic-grade glass fiber cloth with a prepreg, heating the mixture in an oven at 160° C. for 3 minutes, and stacking the prepregs with a layer of electrolytic copper foil on each side, with two layers of prepregs placed in the middle, and curing and pressing the mixture in a high-temperature press at 200° C. for 4 hours to obtain a circuit substrate.

[0066] Example 4

[0067] 20 parts by weight of low molecular weight bisphenol A epoxy vinyl resin (color = 3, molecular weight = 497, carbon-carbon double bond content = 9%), 20 parts by weight of high molecular weight bisphenol A epoxy resin (color = 1, molecular weight = 3600, carbon-carbon double bond content = 0), 30 parts by weight of epoxy compound (structural formula is formula 4), 30 parts by weight of bisphenol A novolac epoxy resin (Tg = 185°C, color = 7), 50 parts by weight of methyltetrahydrophthalic anhydride curing agent, 50 parts by weight of methylhexahydrophthalic anhydride curing agent, 15 parts by weight of dicyandiamide (the number of anhydride groups in the anhydride curing agent is the same as the number of active groups in the amine curing agent) The resin composition was impregnated on 2116 electronic grade glass fiber cloth and heated in an oven at 160° C. for 3 minutes to obtain a prepreg. The prepreg was then stacked with two layers of electrolytic copper foil on the top and bottom, and two layers of prepreg were placed in the middle. The mixture was cured and pressed in a high temperature press at 200° C. for 4 hours to obtain a circuit substrate.

[0068] Example 5

[0069] 10 parts by weight of a low molecular weight acrylic resin (color = 1, molecular weight = 380, carbon-carbon double bond content = 0), 30 parts by weight of a high molecular weight bisphenol A epoxy resin (color = 1, molecular weight = 3300, carbon-carbon double bond content = 0), 30 parts by weight of an epoxy compound (structural formula is Formula 2-1), 30 parts by weight of a bisphenol A novolac epoxy resin (Tg = 185°C, color = 7), 100 parts by weight of a methyltetrahydrophthalic anhydride curing agent, 2 parts by weight of dicyandiamide (the ratio of the number of anhydride groups in the anhydride curing agent to the number of active hydrogens in the amine curing agent = 1:0.1) were added. 6) adding 100 parts by weight of acetone, 40 parts by weight of propylene glycol methyl ether, and 1 part by weight of a silane coupling agent, dissolving and mixing them uniformly, then adding 180 parts by weight of titanium dioxide (whiteness = 98%), stirring and dispersing at high speed, and stirring for 120 minutes to prepare a resin composition; impregnating the above resin composition on 2116 type electronic grade glass fiber cloth, heating it in an oven at 160° C. for 3 minutes to obtain a prepreg, and then stacking two layers of prepreg in the middle with a layer of electrolytic copper foil on the top and bottom, and curing and pressing them in a high-temperature press at 200° C. for 4 hours to obtain a circuit substrate.

[0070] Example 6

[0071] 15 parts by weight of low molecular weight bisphenol A epoxy resin (color = 1, molecular weight = 380, carbon-carbon double bond content = 0), 30 parts by weight of high molecular weight bisphenol A epoxy resin (color = 1, molecular weight = 3600, carbon-carbon double bond content = 0), 30 parts by weight of epoxy compound (structural formula is formula 1-1), 30 parts by weight of hydantoin epoxy resin (Tg = 190°C, color = 4), 30 parts by weight of methyltetrahydrophthalic anhydride curing agent, 70 parts by weight of methylhexahydrophthalic anhydride curing agent, 6 parts by weight of dicyandiamide (the ratio of the number of anhydride groups in the anhydride curing agent to the number of active hydrogens in the amine curing agent) were prepared. =1:0.48), 100 parts by weight of acetone, 40 parts by weight of propylene glycol methyl ether, and 1 part by weight of a silane coupling agent were added, dissolved and mixed uniformly, and then 180 parts by weight of titanium dioxide (whiteness = 98%) was added, and the mixture was dispersed by high-speed stirring and stirred for 120 minutes to prepare a resin composition; the resin composition was impregnated on 2116 electronic-grade glass fiber cloth, and heated in an oven at 160°C for 3 minutes to obtain a prepreg, and then a layer of electrolytic copper foil was placed on the top and bottom, with two layers of prepreg placed in the middle, and cured and pressed in a high-temperature press at 200°C for 4 hours to obtain a circuit substrate.

[0072] Example 7

[0073] 15 parts by weight of low molecular weight bisphenol A epoxy resin (color = 1, molecular weight = 380, carbon-carbon double bond content = 0), 30 parts by weight of high molecular weight bisphenol A epoxy resin (color = 1, molecular weight = 3600, carbon-carbon double bond content = 0), 30 parts by weight of epoxy compound (structural formula is formula 1-1), 30 parts by weight of hydantoin epoxy resin (Tg = 190 ° C, color = 4), 100 parts by weight of sodium methyl dichloride, 100 parts by weight of acetone, 40 parts by weight of propylene glycol methyl ether were added to the mixture. Ether and 1 part by weight of a silane coupling agent are dissolved and mixed uniformly, and then 180 parts by weight of titanium dioxide (whiteness = 98%) is added, and the mixture is dispersed by high-speed stirring and stirred for 120 minutes to prepare a resin composition; the resin composition is impregnated on 2116 type electronic grade glass fiber cloth, and heated in an oven at 160°C for 3 minutes to obtain a prepreg, and then a layer of electrolytic copper foil is stacked on the top and bottom with two layers of prepreg in the middle, and cured and pressed in a high-temperature press at 200°C for 4 hours to obtain a circuit substrate.

[0074] Example 8

[0075] 15 parts by weight of low molecular weight bisphenol A epoxy resin (color = 1, molecular weight = 380, carbon-carbon double bond content = 0), 30 parts by weight of high molecular weight bisphenol A epoxy resin (color = 1, molecular weight = 3600, carbon-carbon double bond content = 0), 30 parts by weight of epoxy compound (structural formula is formula 5), 30 parts by weight of hydantoin epoxy resin (Tg = 190°C, color = 4), 30 parts by weight of methyltetrahydrophthalic anhydride curing agent, 70 parts by weight of methylhexahydrophthalic anhydride curing agent, 2 parts by weight of dicyandiamide (the ratio of the number of anhydride groups in the anhydride curing agent to the number of active hydrogens in the amine curing agent) were prepared. =0.16), 100 parts by weight of acetone, 40 parts by weight of propylene glycol methyl ether, and 1 part by weight of a silane coupling agent were added, dissolved and mixed uniformly, and then 180 parts by weight of titanium dioxide (whiteness = 98%) was added, and the mixture was dispersed by high-speed stirring and stirred for 120 minutes to prepare a resin composition; the resin composition was impregnated on 2116 type electronic grade glass fiber cloth, and heated in an oven at 160° C. for 3 minutes to obtain a prepreg, and then a layer of electrolytic copper foil was placed on the top and bottom, with two layers of prepreg placed in the middle, and cured and pressed in a high-temperature press at 200° C. for 4 hours to obtain a circuit substrate.

[0076] Example 9

[0077] 10 parts by weight of low molecular weight bisphenol A epoxy resin (color = 1, molecular weight = 380, carbon-carbon double bond content = 0), 35 parts by weight of high molecular weight bisphenol A epoxy resin (color = 1, molecular weight = 3600, carbon-carbon double bond content = 0), 30 parts by weight of epoxy compound (structural formula is formula 1-1), 30 parts by weight of hydantoin epoxy resin (Tg = 190°C, color = 4), 30 parts by weight of methyltetrahydrophthalic anhydride curing agent, 70 parts by weight of methylhexahydrophthalic anhydride curing agent, 2 parts by weight of dicyandiamide (the ratio of the number of anhydride groups in the anhydride curing agent to the number of active hydrogens in the amine curing agent) were prepared. =1:0.16), 100 parts by weight of acetone, 40 parts by weight of propylene glycol methyl ether, and 1 part by weight of a silane coupling agent were added, dissolved and mixed uniformly, and then 180 parts by weight of titanium dioxide (whiteness = 98%) was added, and the mixture was dispersed with high-speed stirring and stirred for 120 minutes to prepare a resin composition; the resin composition was impregnated on 2116 type electronic grade glass fiber cloth, and heated in an oven at 160°C for 3 minutes to obtain a prepreg, and then two layers of electrolytic copper foil were stacked in the middle, and cured and pressed in a high-temperature press at 200°C for 4 hours to obtain a circuit substrate.

[0078] Example 10

[0079] 30 parts by weight of low molecular weight bisphenol A epoxy resin (color = 1, molecular weight = 380, carbon-carbon double bond content = 0), 10 parts by weight of high molecular weight bisphenol A epoxy resin (color = 1, molecular weight = 3600, carbon-carbon double bond content = 0), 30 parts by weight of epoxy compound (structural formula is formula 1-1), 30 parts by weight of hydantoin epoxy resin (Tg = 190°C, color = 4), 30 parts by weight of methyltetrahydrophthalic anhydride curing agent, 70 parts by weight of methylhexahydrophthalic anhydride curing agent, 2 parts by weight of dicyandiamide (the ratio of the number of anhydride groups in the anhydride curing agent to the number of active hydrogens in the amine curing agent) were prepared. =1:0.16), 100 parts by weight of acetone, 40 parts by weight of propylene glycol methyl ether, and 1 part by weight of a silane coupling agent were added, dissolved and mixed uniformly, and then 180 parts by weight of titanium dioxide (whiteness = 98%) was added, and the mixture was dispersed with high-speed stirring and stirred for 120 minutes to prepare a resin composition; the resin composition was impregnated on 2116 type electronic grade glass fiber cloth, and heated in an oven at 160°C for 3 minutes to obtain a prepreg, and then two layers of electrolytic copper foil were stacked in the middle, and cured and pressed in a high-temperature press at 200°C for 4 hours to obtain a circuit substrate.

[0080] Example 11

[0081] 15 parts by weight of a low molecular weight bisphenol A epoxy resin (color = 1, molecular weight = 380, carbon-carbon double bond content = 0), 30 parts by weight of a high molecular weight bisphenol A epoxy resin (color = 1, molecular weight = 3600, carbon-carbon double bond content = 0), 30 parts by weight of an epoxy compound (structural formula is formula 1-1), 30 parts by weight of a methyltetrahydrophthalic anhydride curing agent, 70 parts by weight of a methylhexahydrophthalic anhydride curing agent, and 2 parts by weight of dicyandiamide (the ratio of the number of anhydride groups in the anhydride curing agent to the number of active hydrogens in the amine curing agent = 1:0.16) were added. 100 parts by weight of acetone, 40 parts by weight of propylene glycol methyl ether, and 1 part by weight of a silane coupling agent are dissolved and mixed uniformly, and then 180 parts by weight of titanium dioxide (whiteness = 98%) is added, and the mixture is dispersed with high-speed stirring and stirred for 120 minutes to form a resin composition; the above resin composition is impregnated on 2116 type electronic grade glass fiber cloth, and heated in an oven at 160°C for 3 minutes to obtain a prepreg, and then two layers of prepreg are stacked with a layer of electrolytic copper foil on the top and bottom, and two layers of prepreg are placed in the middle, and cured and pressed in a high-temperature press at 200°C for 4 hours to obtain a circuit substrate.

[0082] Example 12

[0083] 15 parts by weight of a low molecular weight bisphenol A epoxy resin (color = 1, molecular weight = 380, carbon-carbon double bond content = 0), 30 parts by weight of a high molecular weight bisphenol A epoxy resin (color = 1, molecular weight = 3600, carbon-carbon double bond content = 0), 30 parts by weight of an epoxy compound (structural formula: Formula 1-1), 30 parts by weight of a benzoxazine resin (Tg = 300°C, color = 16), 30 parts by weight of a methyltetrahydrophthalic anhydride curing agent, 70 parts by weight of a methylhexahydrophthalic anhydride curing agent, 2 parts by weight of dicyandiamide (the ratio of the number of anhydride groups in the anhydride curing agent to the number of active hydrogens in the amine curing agent) were prepared. =1:0.16), 100 parts by weight of acetone, 40 parts by weight of propylene glycol methyl ether, and 1 part by weight of a silane coupling agent were added, dissolved and mixed uniformly, and then 180 parts by weight of titanium dioxide (whiteness = 98%) was added, and the mixture was dispersed with high-speed stirring and stirred for 120 minutes to prepare a resin composition; the resin composition was impregnated on 2116 type electronic grade glass fiber cloth, and heated in an oven at 160°C for 3 minutes to obtain a prepreg, and then two layers of electrolytic copper foil were stacked in the middle, and cured and pressed in a high-temperature press at 200°C for 4 hours to obtain a circuit substrate.

[0084] Example 13

[0085] 15 parts by weight of a low molecular weight bisphenol A epoxy resin (color = 1, molecular weight = 380, carbon-carbon double bond content = 0), 30 parts by weight of a high molecular weight bisphenol A epoxy resin (color = 1, molecular weight = 3600, carbon-carbon double bond content = 0), 30 parts by weight of an epoxy compound (structural formula is Formula 1-1), 30 parts by weight of a hydantoin epoxy resin (Tg = 190°C, color = 4), 30 parts by weight of a methyltetrahydrophthalic anhydride curing agent, 70 parts by weight of a methylhexahydrophthalic anhydride curing agent, and 2 parts by weight of dicyandiamide (the ratio of the number of anhydride groups in the anhydride curing agent to the number of active hydrogens in the amine curing agent = 1:0.16) were added. 100 parts by weight of acetone, 40 parts by weight of propylene glycol methyl ether, and 1 part by weight of a silane coupling agent are dissolved and mixed uniformly, and then 180 parts by weight of titanium dioxide (whiteness = 98%), 20 parts by weight of angular alumina, and 50 parts by weight of spherical alumina are added, and the mixture is dispersed by high-speed stirring for 120 minutes to prepare a resin composition. The resin composition is impregnated onto 2116 electronic-grade glass fiber cloth, and heated in an oven at 160° C. for 3 minutes to obtain a prepreg. Subsequently, two layers of prepreg are stacked, each with a layer of electrolytic copper foil on the top and bottom, and two layers of prepreg are placed in the middle. The mixture is cured and pressed in a high-temperature press at 200° C. for 4 hours to obtain a circuit substrate.

[0086] Comparative Example 1

[0087] The difference between Comparative Example 1 and Example 1 is that 20 parts by weight of a low molecular weight polyimide resin (chroma = 4, molecular weight = 580, carbon-carbon double bond content = 0) and 20 parts by weight of a high molecular weight biphenyl epoxy resin (chroma = 5, molecular weight = 3000, carbon-carbon double bond content = 0) are used.

[0088] Comparative Example 2

[0089] The difference between Comparative Example 2 and Example 1 is that 20 parts by weight of a low molecular weight hydrocarbon resin (color = 2, molecular weight = 180, carbon-carbon double bond content = 25%) and 20 parts by weight of a high molecular weight hydrocarbon resin (color = 2, molecular weight = 3000, carbon-carbon double bond content = 40%) are used.

[0090] Comparative Example 3

[0091] The difference between Comparative Example 3 and Example 1 is that 40 parts by weight of high molecular weight bisphenol A epoxy resin (chroma = 1, molecular weight = 3600, carbon-carbon double bond content = 0) is used.

[0092] Comparative Example 4

[0093] The difference between Comparative Example 4 and Example 1 is that 20 parts by weight of a low molecular weight bisphenol F epoxy resin (color = 3, molecular weight = 370, carbon-carbon double bond content = 0) and 20 parts by weight of a high molecular weight bisphenol A epoxy resin (color = 2, molecular weight = 5500, carbon-carbon double bond content = 0) are used.

[0094] Comparative Example 5

[0095] The difference between Comparative Example 5 and Example 1 is that 30 parts by weight of dicyclopentadiene phenol epoxy resin (structural formula: Formula 6) is used instead of 30 parts by weight of epoxy compound (structural formula: Formula 1-1).

[0096] Comparative Example 6

[0097] The difference between Comparative Example 6 and Example 1 is that 30 parts by weight of bisphenol A epoxy resin is used instead of 30 parts by weight of the epoxy compound (structural formula is Formula 1-1).

[0098] Comparative Example 7

[0099] The difference between Comparative Example 7 and Example 1 is that 30 parts by weight of phenolic resin is used instead of 30 parts by weight of epoxy compound (structural formula is Formula 1-1).

[0100] Comparative Example 8

[0101] The difference between Comparative Example 8 and Example 1 is that 180 parts by weight of talc (whiteness = 85%) are used instead of 180 parts by weight of titanium dioxide (whiteness = 98%).

[0102] Performance tests were conducted on the circuit substrates prepared in all embodiments and comparative examples. The test indicators and methods are as follows:

[0103] (1) Heat resistance: The glass transition temperature (Tg) was tested by dynamic mechanical analysis (DMA) according to the DMA method specified in IPC-TM-650 2.4.24.

[0104] (2) Initial reflectance: A surface conductive layer of a circuit board was removed to obtain a measurement sample. The initial reflectance of the measurement sample at 457 nm was measured using a spectrocolorimeter in accordance with JIS Z-8722.

[0105] (3) Yellowing resistance: The sample obtained in the above initial reflectivity test was heated in a hot air dryer at 200°C for 2 hours. The same procedure as the above initial reflectivity test was then performed to measure the reflectivity after heat treatment. The difference between the reflectivity after heat treatment and the initial reflectivity was used to characterize the yellowing resistance. The smaller the difference, the better the yellowing resistance.

[0106] (4) Thermal conductivity: The thermal conductivity was tested according to ASTM D5470.

[0107] The performance test results of the circuit substrates prepared in all the embodiments and comparative examples are shown in Table 1.

[0108] Table 1

[0109]

[0110] As can be seen from the test results in the table, under the same test conditions, all embodiments have higher glass transition temperatures and initial reflectivity than all comparative examples, and the change in reflectivity after heat treatment is small, wherein the number of benzene rings in the epoxy compound used in Comparative Example 5 is greater than 3, the epoxy compound used in Comparative Example 6 does not contain aliphatic rings, and Comparative Example 7 uses a phenolic resin without epoxy groups, so that the yellowing resistance of Comparative Examples 5 to 7 is poor. It should be noted that the thermal conductivity of the circuit substrate is mainly affected by the influence of thermal conductive fillers. Since Examples 2 to 12 and Comparative Examples 1 to 8 do not add thermal conductive fillers, their thermal conductivity is roughly the same as that of Example 1, so this performance is not tested. Therefore, the circuit substrate prepared from the resin composition provided by the present invention has excellent initial reflectivity and heat resistance, as well as excellent yellowing resistance, and can meet the needs of a harsh use environment.

[0111] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0112] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A resin composition, characterized in that The resin composition comprises a low-chroma resin, an epoxy compound, a filler and a curing agent; The low-color resin has a Gardner color of ≤3 and a carbon-carbon double bond content of ≤10%, and the low-color resin includes a first resin with a weight-average molecular weight of 3000-4000 and a second resin with a weight-average molecular weight of <2000; the epoxy compound includes an aliphatic ring, and the number of benzene rings is ≤3; and the filler includes at least a first filler with a whiteness of >90%.

2. The resin composition according to claim 1, wherein The weight ratio of the first resin to the second resin is 1:1 to 3:

1.

3. The resin composition according to claim 1, wherein The first resin and the second resin are each independently selected from at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, bisphenol AD epoxy resin, hydrogenated bisphenol A epoxy resin, acrylic resin, and bisphenol A polyester resin.

4. The resin composition according to claim 1, characterized in that The epoxy compound is selected from at least one of the compounds represented by formula (1), formula (2) and formula (3), Wherein, 1≤m≤20, 1≤n≤20, X is selected from a C1-C5 alkyl group or an ester group, R1-R7 are each independently selected from -H, an epoxy group or a C1-C6 alkyl group, and at least one of R1 and R2 is selected from an epoxy group, at least one of R3, R4 and R5 is selected from an epoxy group, and at least one of R6 and R7 is selected from an epoxy group.

5. The resin composition according to claim 1, wherein The weight of the first filler accounts for ≥40% of the weight of the resin composition.

6. The resin composition according to claim 1, characterized in that The filler further includes a second filler, and the second filler is selected from at least one of aluminum oxide, boron nitride, silicon carbide, aluminum nitride, silicon dioxide, boehmite, talc and calcium carbonate.

7. The resin composition according to claim 1, characterized in that The curing agent includes at least one of an anhydride curing agent or an active ester curing agent.

8. The resin composition according to claim 7, characterized in that The curing agent at least includes an acid anhydride curing agent and an amine curing agent, and the ratio of the number of acid anhydride groups in the acid anhydride curing agent to the number of active hydrogens in the amine curing agent is 1:0 to 1:

5.

9. The resin composition according to claim 1, characterized in that Based on 100 parts by weight of the total of the low-chroma resin and the epoxy compound, the amount of the filler is 100 to 250 parts by weight, and the amount of the curing agent is 80 to 120 parts by weight, wherein the weight ratio of the low-chroma resin to the epoxy compound is 1:3 to 3:

1.

10. The resin composition according to any one of claims 1 to 9, characterized in that The resin composition further includes an auxiliary resin, and the Tg of the auxiliary resin is ≥180°C.

11. The resin composition according to claim 10, characterized in that The auxiliary resin has a Gardner color of ≤10.

12. The resin composition according to claim 10, characterized in that The auxiliary resin is selected from at least one of bisphenol A novolac epoxy resin, o-cresol novolac epoxy resin, hydantoin epoxy resin, multifunctional epoxy resin and biphenyl epoxy resin.

13. The resin composition according to claim 10, characterized in that The total weight of the low-color resin, the auxiliary resin, and the epoxy compound is 100 parts, wherein the weight ratio of the low-color resin to the auxiliary resin is 1:2 to 3:

1.

14. A prepreg made from the resin composition according to any one of claims 1 to 13.

15. A circuit substrate manufactured using the prepreg according to claim 14.

16. A printed circuit board manufactured using the circuit substrate according to claim 15.

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