Prepreg, circuit board, and printed circuit board

Abstract

The present application relates to a kind of prepreg, circuit board and printed circuit board, the prepreg includes reinforcing material and the resin composition attached to the reinforcing material, the raw material of the resin composition includes diphenyl type multi-maleimide, polyfunctional epoxy compound, benzoxazine resin and filler;Wherein, the mass ratio of the diphenyl type multi-maleimide and the polyfunctional epoxy compound is 1:0.7-1:1, the sum of the mass of the diphenyl type multi-maleimide, the mass ratio of polyfunctional epoxy compound and the mass of the benzoxazine resin is 0.8:1-1.2:1.The present application is by the selection of three kinds of resin in the raw material of resin composition, the control of ratio and the filling of filler, so that the circuit board has high heat resistance, glass transition temperature and low thermal expansion coefficient, hygroscopicity, and further, the printed circuit board made of the circuit board can more stably bear electronic device.

Description

Technical Field

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

[0002] At present, printed circuit boards (PCBs) are mostly used to carry electronic devices, and circuit substrates such as copper clad laminates are used as substrate materials for PCBs, and their main functions are conductivity, insulation and support.

[0003] Since the heat dissipation during operation of electronic devices will gradually increase the overall temperature of the PCB, it will not only cause the electronic devices to deform, but also cause the connection between the PCB and the electronic devices to fail. Therefore, with the advancement of electronic device manufacturing processes, the heat resistance, glass transition temperature (Tg), and thermal expansion coefficient (CTE) requirements of circuit substrates are becoming increasingly stringent. However, in conventional technology, cyanate esters and bismaleimide resins are generally used to prepare circuit substrates. Although cyanate esters and bismaleimide resins can polymerize to form a stable triazine ring structure at high temperatures, the hygroscopicity of cyanate esters and bismaleimide resins is poor, which can cause the circuit substrate to easily delaminate when heated and have poor heat resistance. Moreover, due to the relatively simple composition, the CTE and Tg of the circuit substrate are not good. Summary of the Invention

[0004] Based on this, it is necessary to provide a semi-cured sheet, a circuit substrate and a printed circuit board to address the above problems. The circuit substrate has high heat resistance, glass transition temperature, low thermal expansion coefficient and hygroscopicity. The printed circuit board made of the circuit substrate can stably carry electronic devices.

[0005] A prepreg comprises a reinforcing material and a resin composition attached to the reinforcing material, wherein the raw materials of the resin composition include biphenyl polymaleimide, a multifunctional epoxy compound, a benzoxazine resin and a filler;

[0006] The mass ratio of the biphenyl polymaleimide to the multifunctional epoxy compound is 1:0.7-1:1, and the mass ratio of the sum of the masses of the biphenyl polymaleimide and the multifunctional epoxy compound to the benzoxazine resin is 0.8:1-1.2:1.

[0007] In one embodiment, the molar amount of polar groups in the biphenyl polymaleimide is less than 20%.

[0008] In one embodiment, the biphenyl-type polymaleimide is selected from the biphenyl-type polymaleimide having the structural formula shown in formula (1),

[0009]

[0010] In formula (1), R1 is C a H 2a , 2≤a≤3, 6≤n≤10.

[0011] In one embodiment, the multifunctional epoxy compound is selected from the epoxy compound having the structural formula shown in formula (2),

[0012]

[0013] In formula (2), R2 is a group containing at least one benzene ring.

[0014] In one embodiment, the R2 is selected from a bisphenol type group.

[0015] In one embodiment, the benzoxazine resin is selected from at least one of a diamine benzoxazine resin and a heterocyclic benzoxazine resin.

[0016] In one embodiment, based on 100 parts by weight of the sum of the biphenyl polymaleimide, the multifunctional epoxy compound and the benzoxazine resin, the amount of the filler is 120 parts by weight to 180 parts by weight.

[0017] In one embodiment, the filler is selected from at least one of boehmite, alumina or silica powder.

[0018] In one embodiment, the resin composition further comprises at least one of a coupling agent, a catalyst, and a flame retardant.

[0019] A circuit substrate comprises an insulating layer and a conductive layer arranged on at least one surface of the insulating layer, wherein the insulating layer is formed by pressing one or at least two superimposed prepregs.

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

[0021] Among the raw materials in the resin composition of the present invention, the biphenyl polymaleimide can reduce the water absorption rate of the circuit substrate and improve its heat resistance, the multifunctional epoxy compound can increase the Tg of the circuit substrate, and the benzoxazine resin can improve the heat resistance of the circuit substrate and reduce the CTE. Furthermore, the multifunctional epoxy compound can control the reaction process between the biphenyl polymaleimide and the benzoxazine resin, while the benzoxazine resin can promote the reaction between the biphenyl polymaleimide and the multifunctional epoxy compound. Thus, by selecting the three resin types in the resin composition, controlling the ratio, and adding fillers, the circuit substrate produced using the composition has high heat resistance, a low glass transition temperature, a low coefficient of thermal expansion, and low hygroscopicity. Furthermore, printed circuit boards made using the circuit substrate can more stably support electronic devices. 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 prepreg provided by the present invention comprises a reinforcing material and a resin composition attached to the reinforcing material, wherein the raw materials of the resin composition include biphenyl polymaleimide, a multifunctional epoxy compound, a benzoxazine resin and a filler.

[0025] Among the raw materials for the resin composition of the present invention, the biphenyl-type polymaleimide contains biphenyl groups, which can reduce its water absorption, thereby improving the heat resistance of the circuit substrate. However, this also affects the crosslinking density after the reaction, thereby affecting the Tg and CTE of the circuit substrate. The multifunctional epoxy compound contains multiple reactive epoxy groups, which can increase the crosslinking density of the resin system, thereby improving the Tg and CTE of the circuit substrate. However, the multifunctional epoxy compound and the biphenyl-type polymaleimide do not produce a crosslinking reaction independently.

[0026] Therefore, the present invention introduces benzoxazine resin as a curing agent, which can react with maleimide and epoxy groups. The benzene ring in its structure can effectively improve the overall heat resistance and Tg. At the same time, benzoxazine can form a three-dimensional cross-linked structure with epoxy and maleimide groups, effectively reducing the CTE of the circuit substrate while curing the epoxy and bismaleimide groups.

[0027] Furthermore, in the resin composition of the present invention, the benzoxazine resin serves as a bridge between the biphenyl polymaleimide and the multifunctional epoxy compound. Simultaneously, the multifunctional epoxy compound can control the reaction process between the biphenyl polymaleimide and the benzoxazine resin, allowing the three to cooperate with each other.

[0028] In the matching process, if the proportion of the biphenyl type multi-maleimide is too large, the water absorption of the circuit board will be too high, and if the proportion is too small, the Tg will be too low; if the proportion of the multi-functional epoxy compound is too large, it will react excessively with the benzoxazine, and cannot form the mutual crosslinking of the three resins, and if the proportion is too small, the reaction rate of the composition at high temperature will be too fast, affecting the performance; if the proportion of the benzoxazine resin is too large, the benzoxazine is prone to self-polymerization, resulting in a low Tg, and if the proportion is too small, the curing effect is poor, resulting in incomplete reaction of the epoxy groups and the maleimide groups, affecting the heat resistance and water absorption. Therefore, the mass ratio of the biphenyl type multi-maleimide to the multi-functional epoxy compound is further limited to 1:0.7-1:1, and the mass ratio of the sum of the mass of the biphenyl type multi-maleimide and the mass of the multi-functional epoxy compound to the mass of the benzoxazine resin is 0.8:1-1.2:1.

[0029] Therefore, by selecting and controlling the proportions of the three types of resins in the resin composition and filling the fillers, the circuit board made of the resin composition has high heat resistance, glass transition temperature, low thermal expansion coefficient and moisture absorption, and further, the printed circuit board made of the circuit board can more stably bear electronic devices.

[0030] Since the maleimide group has large polarity, in an embodiment, the molar amount of the polar group of the biphenyl type multi-maleimide is preferably less than 20%, and further preferably 13%-16%, which can better reduce the water absorption of the resin and improve the heat resistance and other properties of the circuit board.

[0031] In order to further improve the heat resistance and other properties of the circuit board, in an embodiment, the biphenyl type multi-maleimide is selected from the biphenyl type multi-maleimide with the structural formula as shown in formula (1),

[0032]

[0033] In formula (1), R1 is C a H 2a , 2≤a≤3, 6≤n≤10.

[0034] Alternatively, the biphenyl type multi-maleimide can be prepared by pre-polymerization of maleic anhydride and 2,2-diaminobiphenyl in DMF solvent, adding sodium acetate and acetic anhydride, and performing pre-polymerization at 90°C.

[0035] In an embodiment, the multi-functional epoxy compound is selected from the epoxy compound with the structural formula as shown in formula (2), and the multi-functional epoxy compound with this structure is particularly obvious in improving the CTE, Tg and other properties.

[0036]

[0037] In formula (2), R2 is a group containing at least one benzene ring.

[0038] Furthermore, the R2 is selected from a bisphenol type group, including but not limited to a bisphenol F type group, a bisphenol A type group, and a bisphenol S type group, preferably a bisphenol F type group.

[0039] In one embodiment, the benzoxazine resin is selected from at least one of a diamine benzoxazine resin and a heterocyclic benzoxazine resin. The diamine benzoxazine resin or the heterocyclic benzoxazine resin contains multiple carbon ring structures, which can further improve the heat resistance and Tg of the circuit substrate.

[0040] In order to further improve the heat resistance of the circuit substrate and reduce its CTE, in one embodiment, the amount of the filler is 120 to 180 parts by weight, based on 100 parts by weight of the sum of the biphenyl polymaleimide, the multifunctional epoxy compound, and the benzoxazine resin. The filler is preferably an inorganic filler, further preferably at least one selected from boehmite, alumina, or silica powder.

[0041] In one embodiment, the resin composition further includes at least one of a coupling agent, a catalyst, and a flame retardant; wherein, based on 100 parts by weight of the sum of the biphenyl-type polymaleimide, the multifunctional epoxy compound, and the benzoxazine resin, the amount of the coupling agent is 0.5 parts by weight to 1 part by weight; the amount of the catalyst is 0.5 parts by weight to 1 part by weight; and the amount of the flame retardant is 5 parts by weight to 10 parts by weight.

[0042] Optionally, the coupling agent is selected from silane coupling agents, preferably at least one of aminosilane coupling agents, vinylsilane coupling agents, and epoxysilane coupling agents.

[0043] Optionally, the flame retardant is selected from at least one of DOPO flame retardant, hexachlorocyclotriphosphazene or magnesium hydroxide.

[0044] Optionally, the catalyst is selected from at least one of an imidazole catalyst, a DCP free radical initiator, and a carboxylate cationic catalyst to further adjust the reaction rate between the biphenyl polymaleimide, the multifunctional epoxy compound, and the benzoxazine resin.

[0045] The specific preparation method of the prepreg of the present invention is not limited. In one embodiment, the resin composition is mixed with a solvent to prepare a glue solution, and then the glue solution is impregnated with a reinforcing material such as glass fiber cloth and dried to obtain a prepreg. The present invention does not limit the type of solvent. Optionally, the solvent is preferably an organic solvent, including at least one of acetone, butanone, propylene glycol methyl ether, propylene glycol methyl ether acetate, toluene, xylene, and cyclohexanone.

[0046] The present invention also provides a circuit substrate, comprising an insulating layer and a conductive layer provided on at least one surface of the insulating layer, wherein the insulating layer is formed by pressing one or at least two superimposed prepregs.

[0047] The present invention also provides a printed circuit board, which is mainly made of the circuit substrate through processes such as drilling, hole filling, micro-etching, pre-impregnation, activation, acceleration, chemical copper and copper thickening.

[0048] Hereinafter, the prepreg, circuit substrate and printed circuit board will be further described through the following specific embodiments.

[0049] Example 1

[0050] 25 parts by weight of a biphenyl-type polymaleimide (the structural formula of the biphenyl-type polymaleimide refers to formula (1), except that R1 is -CH2-, n=2, and the molar amount of the polar group is 22%), 25 parts by weight of a biphenyl-type multifunctional epoxy compound, 50 parts by weight of bisphenol A-type benzoxazine, and 150 parts by weight of butanone are mixed and stirred in a stirring tank for 2 hours, and then 150 parts by weight of silicon micropowder and 0.8 parts by weight of a silane coupling agent are added, and the mixture is sheared and dispersed for 1 hour to obtain a resin composition.

[0051] The resin composition was impregnated on electronic grade glass fiber cloth and baked in a hot air circulation oven at 160° C. for 3 minutes to obtain a prepreg.

[0052] Take 4 prepregs and stack them, cover the top and bottom with a 18μm thick electrolytic copper foil, place them in a vacuum hot press, and press them at a pressure of 40kg / cm 2 Under the conditions of temperature of 230℃, hot pressing was carried out for 2h to obtain a circuit substrate with a thickness of 0.4mm.

[0053] Example 2

[0054] 26.4 parts by weight of biphenyl-type polymaleimide (the structural formula of biphenyl-type polymaleimide refers to formula (1), except that R1 is -CH2-, n=2, and the molar amount of the polar group is 22%), 18.6 parts by weight of biphenyl-type multifunctional epoxy compound, 55 parts by weight of bisphenol A-type benzoxazine, and 150 parts by weight of butanone are mixed and stirred in a stirring tank for 2 hours, and then 120 parts by weight of silicon micropowder and 0.5 parts by weight of a silane coupling agent are added, and the mixture is sheared and dispersed for 1 hour to obtain a resin composition.

[0055] The resin composition was impregnated on electronic grade glass fiber cloth and baked in a hot air circulation oven at 160° C. for 3 minutes to obtain a prepreg.

[0056] Take 4 prepregs and stack them, cover the top and bottom with a 18μm thick electrolytic copper foil, place them in a vacuum hot press, and press them at a pressure of 40kg / cm2 Under the conditions of temperature of 230℃, hot pressing was carried out for 2h to obtain a circuit substrate with a thickness of 0.4mm.

[0057] Example 3

[0058] 27.25 parts by weight of a biphenyl-type polymaleimide (the structural formula of the biphenyl-type polymaleimide refers to formula (1), except that R1 is -CH2-, n=2, and the molar amount of the polar group is 22%), 27.25 parts by weight of a biphenyl-type multifunctional epoxy compound, 45.5 parts by weight of bisphenol A-type benzoxazine, and 150 parts by weight of butanone are mixed and stirred in a stirring tank for 2 hours, and then 180 parts by weight of silicon micropowder and 1 part by weight of a silane coupling agent are added, and the mixture is sheared and dispersed for 1 hour to obtain a resin composition.

[0059] The resin composition was impregnated on electronic grade glass fiber cloth and baked in a hot air circulation oven at 160° C. for 3 minutes to obtain a prepreg.

[0060] Take 4 prepregs and stack them, cover the top and bottom with a 18μm thick electrolytic copper foil, place them in a vacuum hot press, and press them at a pressure of 40kg / cm 2 Under the conditions of temperature of 230℃, hot pressing was carried out for 2h to obtain a circuit substrate with a thickness of 0.4mm.

[0061] Example 4

[0062] 25 parts by weight of biphenyl-type polymaleimide (the structural formula of biphenyl-type polymaleimide refers to formula (1), except that R1 is a benzene ring, n=2, and the molar amount of the polar group is 20%), 25 parts by weight of dicyclopentadiene phenol epoxy compound, 50 parts by weight of dicyclopentadiene benzoxazine, and 150 parts by weight of butanone are mixed and stirred in a stirring tank for 2 hours, and then 150 parts by weight of aluminum oxide and 0.8 parts by weight of a silane coupling agent are added, and the mixture is sheared and dispersed for 1 hour to obtain a resin composition.

[0063] The resin composition was impregnated on electronic grade glass fiber cloth and baked in a hot air circulation oven at 160° C. for 3 minutes to obtain a prepreg.

[0064] Take 4 prepregs and stack them, cover the top and bottom with a 18μm thick electrolytic copper foil, place them in a vacuum hot press, and press them at a pressure of 40kg / cm 2 Under the conditions of temperature of 230℃, hot pressing was carried out for 2h to obtain a circuit substrate with a thickness of 0.4mm.

[0065] Example 5

[0066] 27.5 parts by weight of biphenyl-type polymaleimide (the structural formula of the biphenyl-type polymaleimide refers to formula (1), except that R1 is a benzene ring, n=2, and the molar amount of the polar group is 20%), 27.5 parts by weight of dicyclopentadiene phenol epoxy compound, 45.5 parts by weight of dicyclopentadiene benzoxazine, and 150 parts by weight of butanone are mixed and stirred in a stirring tank for 2 hours, and then 120 parts by weight of aluminum oxide and 0.5 parts by weight of a silane coupling agent are added, and the mixture is sheared and dispersed for 1 hour to obtain a resin composition.

[0067] The resin composition was impregnated on electronic grade glass fiber cloth and baked in a hot air circulation oven at 160° C. for 3 minutes to obtain a prepreg.

[0068] Take 4 prepregs and stack them, cover the top and bottom with a 18μm thick electrolytic copper foil, place them in a vacuum hot press, and press them at a pressure of 40kg / cm 2 Under the conditions of temperature of 230℃, hot pressing was carried out for 2h to obtain a circuit substrate with a thickness of 0.4mm.

[0069] Example 6

[0070] 25 parts by weight of biphenyl polymaleimide, the structural formula of biphenyl polymaleimide is referred to formula (1), but R1 is n=2, the molar amount of the polar group is 15.4%, 25 parts by weight of a biphenyl-type multifunctional epoxy compound, 50 parts by weight of bisphenol A-type benzoxazine and 150 parts by weight of butanone are mixed and stirred in a stirring tank for 2 hours, and then 150 parts by weight of silicon micropowder and 0.8 parts by weight of a silane coupling agent are added, and the mixture is sheared and dispersed for 1 hour to obtain a resin composition.

[0071] The resin composition was impregnated on electronic grade glass fiber cloth and baked in a hot air circulation oven at 160° C. for 3 minutes to obtain a prepreg.

[0072] Take 4 prepregs and stack them, cover the top and bottom with a 18μm thick electrolytic copper foil, place them in a vacuum hot press, and press them at a pressure of 40kg / cm 2 Under the conditions of temperature of 230℃, hot pressing was carried out for 2h to obtain a circuit substrate with a thickness of 0.4mm.

[0073] Example 7

[0074] 25 parts by weight of a biphenyl-type polymaleimide having a structural formula as shown in formula (1), wherein a=2, n=6, and a molar amount of polar groups is 15.7%, 25 parts by weight of a biphenyl-type multifunctional epoxy compound, 50 parts by weight of bisphenol A-type benzoxazine, and 150 parts by weight of butanone are mixed and stirred in a stirring tank for 2 hours, and then 150 parts by weight of silicon micropowder and 0.8 parts by weight of a silane coupling agent are added, and the mixture is sheared and dispersed for 1 hour to obtain a resin composition.

[0075] The resin composition was impregnated on electronic grade glass fiber cloth and baked in a hot air circulation oven at 160° C. for 3 minutes to obtain a prepreg.

[0076] Take 4 prepregs and stack them, cover the top and bottom with a 18μm thick electrolytic copper foil, place them in a vacuum hot press, and press them at a pressure of 40kg / cm 2 Under the conditions of temperature of 230℃, hot pressing was carried out for 2h to obtain a circuit substrate with a thickness of 0.4mm.

[0077] Example 8

[0078] 25 parts by weight of a biphenyl-type polymaleimide having a structural formula as shown in formula (1), wherein a=3, n=10, and the molar amount of polar groups is 13.3%, 25 parts by weight of a biphenyl-type multifunctional epoxy compound, 50 parts by weight of bisphenol A-type benzoxazine, and 150 parts by weight of butanone are mixed and stirred in a stirring tank for 2 hours, and then 150 parts by weight of silicon micropowder and 0.8 parts by weight of a silane coupling agent are added, and the mixture is sheared and dispersed for 1 hour to obtain a resin composition.

[0079] The resin composition was impregnated on electronic grade glass fiber cloth and baked in a hot air circulation oven at 160° C. for 3 minutes to obtain a prepreg.

[0080] Take 4 prepregs and stack them, cover the top and bottom with a 18μm thick electrolytic copper foil, place them in a vacuum hot press, and press them at a pressure of 40kg / cm 2 Under the conditions of temperature of 230℃, hot pressing was carried out for 2h to obtain a circuit substrate with a thickness of 0.4mm.

[0081] Example 9

[0082] 25 parts by weight of a biphenyl-type polymaleimide, the structural formula of which is the same as that of formula (1), except that R1 is -CH2-, n=2, and the molar amount of the polar group is 22%, 25 parts by weight of a multifunctional epoxy compound having the structural formula shown in formula (2), wherein R2 is a benzene ring, 50 parts by weight of bisphenol A-type benzoxazine, and 150 parts by weight of butanone are mixed and stirred in a stirring tank for 2 hours, and then 150 parts by weight of silicon micropowder and 0.8 parts by weight of a silane coupling agent are added, and the mixture is sheared and dispersed for 1 hour to obtain a resin composition.

[0083] The resin composition was impregnated on electronic grade glass fiber cloth and baked in a hot air circulation oven at 160° C. for 3 minutes to obtain a prepreg.

[0084] Take 4 prepregs and stack them, cover the top and bottom with a 18μm thick electrolytic copper foil, place them in a vacuum hot press, and press them at a pressure of 40kg / cm 2 Under the conditions of temperature of 230℃, hot pressing was carried out for 2h to obtain a circuit substrate with a thickness of 0.4mm.

[0085] Example 10

[0086] 25 parts by weight of a biphenyl-type polymaleimide, the structural formula of which is the same as that of formula (1), except that R1 is -CH2-, n=2, and the molar amount of the polar group is 22%, 25 parts by weight of a multifunctional epoxy compound having the structural formula shown in formula (2), wherein R2 is a bisphenol F group, 50 parts by weight of bisphenol A-type benzoxazine, and 150 parts by weight of butanone are mixed and stirred in a stirring tank for 2 hours, and then 150 parts by weight of silicon micropowder and 0.8 parts by weight of a silane coupling agent are added, and the mixture is sheared and dispersed for 1 hour to obtain a resin composition.

[0087] The resin composition was impregnated on electronic grade glass fiber cloth and baked in a hot air circulation oven at 160° C. for 3 minutes to obtain a prepreg.

[0088] Take 4 prepregs and stack them, cover the top and bottom with a 18μm thick electrolytic copper foil, place them in a vacuum hot press, and press them at a pressure of 40kg / cm 2 Under the conditions of temperature of 230℃, hot pressing was carried out for 2h to obtain a circuit substrate with a thickness of 0.4mm.

[0089] Example 11

[0090] 25 parts by weight of biphenyl polymaleimide, the structural formula of biphenyl polymaleimide is referred to formula (1), but R1 is n=2, the molar amount of polar groups is 15.4%, 25 parts by weight of a multifunctional epoxy compound having the structural formula shown in formula (2), wherein R2 is a benzene ring, 50 parts by weight of a diamine-type benzoxazine resin, and 150 parts by weight of butanone are mixed and stirred in a stirring tank for 2 hours, and then 150 parts by weight of silicon micropowder and 0.8 parts by weight of a silane coupling agent are added, and the mixture is sheared and dispersed for 1 hour to obtain a resin composition.

[0091] The resin composition was impregnated on electronic grade glass fiber cloth and baked in a hot air circulation oven at 160° C. for 3 minutes to obtain a prepreg.

[0092] Take 4 prepregs and stack them, cover the top and bottom with a 18μm thick electrolytic copper foil, place them in a vacuum hot press, and press them at a pressure of 40kg / cm 2 Under the conditions of temperature of 230℃, hot pressing was carried out for 2h to obtain a circuit substrate with a thickness of 0.4mm.

[0093] Example 12

[0094] 25 parts by weight of a biphenyl-type polymaleimide having a structural formula as shown in formula (1), wherein a=2, n=6, and a molar amount of polar groups is 15.7%, 25 parts by weight of a biphenyl-type multifunctional epoxy compound, 50 parts by weight of a heterocyclic benzoxazine resin, and 150 parts by weight of butanone are mixed and stirred in a stirring tank for 2 hours, and then 150 parts by weight of silicon micropowder and 0.8 parts by weight of a silane coupling agent are added, and the mixture is sheared and dispersed for 1 hour to obtain a resin composition.

[0095] The resin composition was impregnated on electronic grade glass fiber cloth and baked in a hot air circulation oven at 160° C. for 3 minutes to obtain a prepreg.

[0096] Take 4 prepregs and stack them, cover the top and bottom with a 18μm thick electrolytic copper foil, place them in a vacuum hot press, and press them at a pressure of 40kg / cm 2 Under the conditions of temperature of 230℃, hot pressing was carried out for 2h to obtain a circuit substrate with a thickness of 0.4mm.

[0097] Example 13

[0098] 25 parts by weight of a biphenyl-type polymaleimide of the structural formula shown in formula (1), wherein a=2, n=6, and the molar amount of the polar group is 15.7%, 25 parts by weight of a multifunctional epoxy compound of the structural formula shown in formula (2), wherein R2 is a bisphenol F group, 50 parts by weight of a diamine-type benzoxazine resin, and 150 parts by weight of butanone are mixed and stirred in a stirring tank for 2 hours, and then 150 parts by weight of boehmite and 0.8 parts by weight of a silane coupling agent are added, and the mixture is sheared and dispersed for 1 hour to obtain a resin composition.

[0099] The resin composition was impregnated on electronic grade glass fiber cloth and baked in a hot air circulation oven at 160° C. for 3 minutes to obtain a prepreg.

[0100] Take 4 prepregs and stack them, cover the top and bottom with a 18μm thick electrolytic copper foil, place them in a vacuum hot press, and press them at a pressure of 40kg / cm 2 Under the conditions of temperature of 230℃, hot pressing was carried out for 2h to obtain a circuit substrate with a thickness of 0.4mm.

[0101] Example 14

[0102] 25 parts by weight of a biphenyl-type polymaleimide of the structural formula shown in formula (1), wherein a=2, n=6, and the molar amount of the polar group is 15.7%, 25 parts by weight of a multifunctional epoxy compound of the structural formula shown in formula (2), wherein R2 is a bisphenol F group, 50 parts by weight of a diamine-type benzoxazine resin, and 150 parts by weight of butanone are mixed and stirred in a stirring tank for 2 hours, and then 150 parts by weight of boehmite, 0.7 parts by weight of an imidazole catalyst, and 0.8 parts by weight of a silane coupling agent are added, and the mixture is sheared and dispersed for 1 hour to obtain a resin composition.

[0103] The resin composition was impregnated on electronic grade glass fiber cloth and baked in a hot air circulation oven at 160° C. for 3 minutes to obtain a prepreg.

[0104] Take 4 prepregs and stack them, cover the top and bottom with a 18μm thick electrolytic copper foil, place them in a vacuum hot press, and press them at a pressure of 40kg / cm 2 Under the conditions of temperature of 230℃, hot pressing was carried out for 2h to obtain a circuit substrate with a thickness of 0.4mm.

[0105] The circuit substrates prepared in Examples 1-14 were tested for thermal delamination time T300, thermal expansion coefficient X / Y, water absorption, and Tg. The thermal expansion coefficient (X / Y) was tested before the temperature reached Tg. The test results are shown in Table 1.

[0106] Table 1

[0107]

[0108]

[0109] Comparative Example 1

[0110] 25 parts by weight of benzyl diamine-modified bismaleimide, 25 parts by weight of a biphenyl-type multifunctional epoxy compound, 50 parts by weight of bisphenol A-type benzoxazine, and 150 parts by weight of butanone were mixed and stirred in a stirring tank for 2 hours, and then 150 parts by weight of silicon micropowder and 0.8 parts by weight of a silane coupling agent were added, and the mixture was sheared and dispersed for 1 hour to obtain a resin composition.

[0111] The resin composition was impregnated on electronic grade glass fiber cloth and baked in a hot air circulation oven at 160° C. for 3 minutes to obtain a prepreg.

[0112] Take 4 prepregs and stack them, cover the top and bottom with a 18μm thick electrolytic copper foil, place them in a vacuum hot press, and press them at a pressure of 40kg / cm 2 Under the conditions of temperature of 230℃, hot pressing was carried out for 2h to obtain a circuit substrate with a thickness of 0.4mm.

[0113] Comparative Example 2

[0114] 25 parts by weight of bismaleimide modified with naphthalene diamine, 25 parts by weight of a biphenyl-type multifunctional epoxy compound, 50 parts by weight of bisphenol A-type benzoxazine, and 150 parts by weight of butanone were mixed and stirred in a stirring tank for 2 hours, and then 150 parts by weight of silicon micropowder and 0.8 parts by weight of a silane coupling agent were added, and the mixture was sheared and dispersed for 1 hour to obtain a resin composition.

[0115] The resin composition was impregnated on electronic grade glass fiber cloth and baked in a hot air circulation oven at 160° C. for 3 minutes to obtain a prepreg.

[0116] Take 4 prepregs and stack them, cover the top and bottom with a 18μm thick electrolytic copper foil, place them in a vacuum hot press, and press them at a pressure of 40kg / cm 2 Under the conditions of temperature of 230℃, hot pressing was carried out for 2h to obtain a circuit substrate with a thickness of 0.4mm.

[0117] Comparative Example 3

[0118] 25 parts by weight of biphenyl polymaleimide (the structural formula of biphenyl polymaleimide refers to formula (1), except that R1 is -CH2-, n=2, and the molar amount of the polar group is 22%), 25 parts by weight of o-cresol epoxy compound, 50 parts by weight of bisphenol A type benzoxazine, and 150 parts by weight of butanone are mixed and stirred in a stirring tank for 2 hours, and then 150 parts by weight of silicon micropowder and 0.8 parts by weight of a silane coupling agent are added, and the mixture is sheared and dispersed for 1 hour to obtain a resin composition.

[0119] The resin composition was impregnated on electronic grade glass fiber cloth and baked in a hot air circulation oven at 160° C. for 3 minutes to obtain a prepreg.

[0120] Take 4 prepregs and stack them, cover the top and bottom with a 18μm thick electrolytic copper foil, place them in a vacuum hot press, and press them at a pressure of 40kg / cm 2 Under the conditions of temperature of 230℃, hot pressing was carried out for 2h to obtain a circuit substrate with a thickness of 0.4mm.

[0121] Comparative Example 4

[0122] 20 parts by weight of biphenyl-type polymaleimide (the structural formula of biphenyl-type polymaleimide refers to formula (1), except that R1 is -CH2-, n=2, and the molar amount of the polar group is 22%), 30 parts by weight of biphenyl-type multifunctional epoxy compound, 50 parts by weight of bisphenol A-type benzoxazine, and 150 parts by weight of butanone are mixed and stirred in a stirring tank for 2 hours, and then 150 parts by weight of silicon micropowder and 0.8 parts by weight of a silane coupling agent are added, and the mixture is sheared and dispersed for 1 hour to obtain a resin composition.

[0123] The resin composition was impregnated on electronic grade glass fiber cloth and baked in a hot air circulation oven at 160° C. for 3 minutes to obtain a prepreg.

[0124] Take 4 prepregs and stack them, cover the top and bottom with a 18μm thick electrolytic copper foil, place them in a vacuum hot press, and press them at a pressure of 40kg / cm 2 Under the conditions of temperature of 230℃, hot pressing was carried out for 2h to obtain a circuit substrate with a thickness of 0.4mm.

[0125] Comparative Example 5

[0126] 25 parts by weight of a biphenyl-type polymaleimide (the structural formula of the biphenyl-type polymaleimide is the same as that of formula (1), except that R1 is -CH2-, n=2, and the molar amount of the polar group is 22%), 25 parts by weight of a biphenyl-type multifunctional epoxy compound, 30 parts by weight of bisphenol A-type benzoxazine, and 150 parts by weight of butanone are mixed and stirred in a stirring tank for 2 hours, and then 150 parts by weight of silicon micropowder and 0.8 parts by weight of a silane coupling agent are added, and the mixture is sheared and dispersed for 1 hour to obtain a resin composition.

[0127] The resin composition was impregnated on electronic grade glass fiber cloth and baked in a hot air circulation oven at 160° C. for 3 minutes to obtain a prepreg.

[0128] Take 4 prepregs and stack them, cover the top and bottom with a 18μm thick electrolytic copper foil, place them in a vacuum hot press, and press them at a pressure of 40kg / cm 2 Under the conditions of temperature of 230℃, hot pressing was carried out for 2h to obtain a circuit substrate with a thickness of 0.4mm.

[0129] The circuit substrates prepared in Comparative Examples 1-5 were tested for thermal delamination time T300, thermal expansion coefficient X / Y, water absorption rate, and Tg. The thermal expansion coefficient (X / Y) was tested before the temperature reached Tg. The test results are shown in Table 2.

[0130] Table 2

[0131]

[0132] The test standards of the above embodiments and comparative examples are as follows:

[0133] Thermal delamination time T300 is tested according to IPC-TM-650 2.4.24.1 standard;

[0134] The coefficient of thermal expansion X / Y is tested according to IPC-TM-650 2.4.41.1 standard;

[0135] Water absorption is tested according to GB / T 4277-2017 9.2 standard;

[0136] The glass transition temperature is tested in accordance with GB / T 4277-2017 6.7.2.

[0137] 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.

[0138] 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 prepreg comprising a reinforcing material and a resin composition attached to the reinforcing material, characterized in that: The raw materials of the resin composition include biphenyl polymaleimide, multifunctional epoxy compound, benzoxazine resin and filler; The mass ratio of the biphenyl polymaleimide to the multifunctional epoxy compound is 1:0.7-1:1, and the mass ratio of the sum of the mass of the biphenyl polymaleimide and the multifunctional epoxy compound to the benzoxazine resin is 0.8:1-1.2:

1. The multifunctional epoxy compound is selected from the epoxy compound having the structural formula shown in formula (2), In formula (2), R2 is a group containing at least one benzene ring.

2. The prepreg according to claim 1, wherein: The molar amount of polar groups in the biphenyl polymaleimide is less than 20%.

3. The prepreg according to claim 1, wherein: The biphenyl type polymaleimide is selected from the biphenyl type polymaleimide having the structural formula shown in formula (1), In formula (1), R1 is C a H 2a , 2≤a≤3, 6≤n≤10.

4. The prepreg according to claim 1, wherein: The R2 is selected from a bisphenol type group.

5. The prepreg according to claim 1, wherein: The benzoxazine resin is selected from at least one of a diamine benzoxazine resin and a heterocyclic benzoxazine resin.

6. The prepreg according to any one of claims 1 to 5, characterized in that: Based on 100 parts by weight of the total amount of the biphenyl polymaleimide, the multifunctional epoxy compound and the benzoxazine resin, the amount of the filler is 120 parts by weight to 180 parts by weight.

7. The prepreg according to claim 6, characterized in that: The filler is selected from at least one of boehmite, alumina or silica powder.

8. The prepreg according to any one of claims 1 to 5, characterized in that: The resin composition further comprises at least one of a coupling agent, a catalyst and a flame retardant.

9. A circuit substrate, characterized in that: The invention comprises an insulating layer and a conductive layer provided on at least one surface of the insulating layer, wherein the insulating layer is formed by pressing one or at least two superimposed prepregs according to any one of claims 1 to 8.

10. A printed circuit board manufactured using the circuit substrate according to claim 9.

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