Pre-polymerized resin as well as preparation method and application thereof

Abstract

The present invention relates to a prepolymer resin, the prepolymer resin is a polymerization product of an auto-polymer and a maleimide resin, the auto-polymer is selected from an isocyanate auto-polymer and / or a cyanate auto-polymer, and the polymerization degrees of the isocyanate auto-polymer and the cyanate auto-polymer are both less than 20. The invention also provides a preparation method and application of the pre-polymerized resin. The pre-polymerized resin is a polymerization product of a self-polymer with a specific polymerization degree and maleimide resin, and the water absorption of the pre-polymerized resin can be effectively reduced, so that the pre-polymerized resin has low water absorption and low thermal expansion coefficient. Furthermore, when the pre-polymerized resin is used for preparing the circuit substrate, the water absorption rate and the thermal expansion coefficient of the circuit substrate are effectively improved, so that the circuit substrate cannot be cracked and layered, and the performance is excellent.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic industry, in particular to a prepolymer resin and a preparation method and application thereof. Background Art

[0002] In recent years, the performance requirements for circuit substrates have become increasingly stringent. For example, high-performance printed circuit boards, especially in the fields of high-density interconnection and integrated circuit packaging, are required to have low warpage.

[0003] Currently, circuit substrates are generally required to have a low coefficient of thermal expansion (CTE) to prevent warping of printed circuit boards. Existing technologies mostly use bismaleimide-triazine resins, which have a low CTE after curing, to produce circuit substrates. However, common bismaleimide-triazine resins are typically obtained by direct polymerization of maleimide resins and cyanate esters. In practical applications, these resins have high water absorption, resulting in poor heat resistance and causing problems such as circuit substrate cracking and delamination. Summary of the Invention

[0004] Based on this, it is necessary to provide a prepolymer resin and its preparation method and application to address the above problems. The prepolymer resin has a low thermal expansion coefficient and low water absorption. When the prepolymer resin is used to prepare a circuit substrate, the circuit substrate has a low thermal expansion coefficient and low water absorption, and will not burst or delaminate, with excellent performance.

[0005] A prepolymer resin is a polymerization product of a self-polymer and a maleimide resin, wherein the self-polymer is selected from an isocyanate self-polymer and / or a cyanate self-polymer, and the polymerization degree of the isocyanate self-polymer and the cyanate self-polymer are both less than 20.

[0006] In one embodiment, the double bond equivalent of the prepolymer resin is ≤500 g / mol.

[0007] In one embodiment, the isocyanate self-polymer is a self-polymerization product of an isocyanate monomer having a molecular structure as shown in formula (I):

[0008]

[0009] wherein R1 and R2 are independently selected from a saturated alkyl chain, an unsaturated alkyl chain, a five-membered cyclic structure or a six-membered cyclic structure, R3 is selected from a cyclic structure, and n≤5;

[0010] And / or, the cyanate self-polymer is a self-polymerization product of a cyanate monomer having a molecular structure as shown in formula (II):

[0011]

[0012] Wherein, R4 and R6 are independently selected from a saturated alkyl chain, an unsaturated alkyl chain, a five-membered cyclic structure or a six-membered cyclic structure, R5 is selected from a cyclic structure, and m≤5.

[0013] In one embodiment, in the isocyanate monomer, the total number of cyclic structures in R1, R2 and R3 is ≤5.

[0014] In one embodiment, the maleimide resin contains two or more aromatic groups in its molecular structure.

[0015] In one embodiment, in the molecular structure of the maleimide resin, the number of aromatic groups is ≤5;

[0016] And / or, the aromatic group is selected from a six-membered ring structure.

[0017] In one embodiment, the mass ratio of the isocyanate monomer to the maleimide resin is 0.1:1-10:1.

[0018] A method for preparing the prepolymer resin as described above comprises the following steps:

[0019] Provided is a self-polymer selected from an isocyanate self-polymer and / or a cyanate self-polymer, wherein a method for preparing the isocyanate self-polymer comprises: mixing an isocyanate monomer, a metal salt catalyst, and a solvent, and heating to carry out a self-polymerization reaction to obtain the isocyanate self-polymer; and a method for preparing the cyanate self-polymer comprises: mixing a cyanate monomer, a metal salt catalyst, and a solvent, and heating to carry out a self-polymerization reaction to obtain the cyanate self-polymer;

[0020] The self-polymer is reacted with maleimide resin to obtain a prepolymer resin.

[0021] In one embodiment, in the step of self-polymerization, the reaction temperature is 100° C.-200° C., and the reaction time is 12 h-48 h;

[0022] And / or, in the step of reacting the self-polymer with maleimide resin, the reaction temperature is 100° C.-200° C., and the reaction time is 1 hour-18 hours.

[0023] A resin composition comprises the above-mentioned prepolymer resin and an initiator.

[0024] In one embodiment, the amount of the prepolymer resin is 50 parts by weight to 90 parts by weight, and the amount of the initiator is 0.001 parts by weight to 0.1 parts by weight.

[0025] In one embodiment, the resin composition further comprises a curing agent, and the amount of the curing agent is 1 part by weight to 10 parts by weight;

[0026] And / or, the resin composition further comprises an auxiliary functional resin, wherein the amount of the auxiliary functional resin is 1 part by weight to 40 parts by weight;

[0027] And / or, the resin composition further comprises a filler, and the amount of the filler is 50 parts by weight to 270 parts by weight.

[0028] In one embodiment, the auxiliary functional resin is selected from at least one of polyolefin resin and polyphenylene ether resin.

[0029] A prepreg made from the resin composition described above.

[0030] A circuit substrate made of the prepreg described above.

[0031] A printed circuit board made of the circuit substrate described above.

[0032] In the present invention, isocyanate self-polymers and / or cyanate self-polymers with a specific degree of polymerization are polymerized with a maleimide resin to obtain a prepolymer resin having a network structure with a higher degree of crosslinking. On the one hand, the highly crosslinked network structure reduces the water absorption of the prepolymer resin. On the other hand, since the isocyanate monomers and / or cyanate monomers first self-polymerize into isocyanate self-polymers and / or cyanate self-polymers, the isocyanate self-polymers and / or cyanate self-polymers contain a relatively small number of isocyanate functional groups and / or cyanate functional groups, which can reduce the water absorption of the prepolymer resin. Therefore, the prepolymer resin of the present invention has low water absorption and low CTE. Thus, when the prepolymer resin is used to prepare a circuit substrate, the circuit substrate has low water absorption and low CTE, and will not explode or delaminate, with excellent performance. DETAILED DESCRIPTION

[0033] 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.

[0034] 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.

[0035] The present invention provides a prepolymer resin, which is a polymerization product of a self-polymer and a maleimide resin, wherein the self-polymer is selected from an isocyanate self-polymer and / or a cyanate self-polymer, and the polymerization degree of the isocyanate self-polymer and the cyanate self-polymer are both less than 20.

[0036] In the present invention, isocyanate self-polymers and / or cyanate self-polymers with a specific degree of polymerization are polymerized with a maleimide resin to obtain a prepolymer resin having a network structure with a higher degree of crosslinking. On the one hand, the highly crosslinked network structure reduces the water absorption of the prepolymer resin. On the other hand, since the isocyanate monomers and / or cyanate monomers first self-polymerize into isocyanate self-polymers and / or cyanate self-polymers, the isocyanate self-polymers and / or cyanate self-polymers contain a relatively small number of isocyanate functional groups and / or cyanate functional groups, which can reduce the water absorption of the prepolymer resin. Therefore, the prepolymer resin of the present invention has low water absorption and low CTE. Thus, when the prepolymer resin is used to prepare a circuit substrate, the circuit substrate has low water absorption and low CTE, and will not explode or delaminate, with excellent performance.

[0037] The present invention preferably uses isocyanate self-polymer and maleimide resin to polymerize to obtain a prepolymer resin. Optionally, the polymerization degree of the isocyanate self-polymer is preferably 10-20, so that a suitable polymerization degree is beneficial to reducing the water absorption of the prepolymer resin, retaining the reactivity of the isocyanate self-polymer, and then being able to polymerize with the maleimide resin, which is beneficial to reducing the CTE of the circuit substrate.

[0038] In the prepolymer resin of the present invention, the double bond equivalent is preferably ≤500 g / mol. The double bond equivalent refers to the mass of the prepolymer resin containing 1 mol of double bonds. A suitable double bond equivalent is beneficial to maintaining the reactivity of the prepolymer resin and ensuring the crosslinking density of the circuit substrate, thereby improving the CTE while reducing the water absorption rate.

[0039] The isocyanate self-polymer of the present invention is preferably a self-polymerization product of an isocyanate monomer having a molecular structure as shown in formula (I):

[0040]

[0041]

[0042] Wherein, R1 and R2 are preferably independently a saturated alkyl chain, an unsaturated alkyl chain, a five-membered cyclic structure, or a six-membered cyclic structure; R3 is preferably a cyclic structure, and n is preferably ≤ 5. Thus, by selecting an isocyanate monomer containing a polycyclic structure, the polymerization efficiency of the isocyanate monomer during self-polymerization to form an isocyanate homopolymer can be improved, which helps further reduce the isocyanate functional group content in the isocyanate homopolymer, thereby reducing the water absorption of the circuit substrate. Furthermore, the isocyanate monomer molecules containing a polycyclic structure have better heat resistance, which can further reduce the CTE of the circuit substrate.

[0043] Optionally, the saturated alkyl chain is preferably a saturated alkyl with a carbon chain length of 1-10, the unsaturated alkyl chain is preferably an alkenyl or alkynyl with a carbon chain length of 2-10, the five-membered ring structure is preferably a five-membered aliphatic ring, a five-membered oxygen heterocycle or a five-membered nitrogen heterocycle, and the six-membered ring structure is preferably a six-membered aliphatic ring, a six-membered aromatic ring, a six-membered oxygen heterocycle or a six-membered nitrogen heterocycle.

[0044] In order to further improve the polymerization activity of the isocyanate homopolymer and the maleimide resin, and to increase the crosslinking density of the prepolymer resin, thereby improving the water absorption and CTE of the prepolymer resin, the total number of cyclic structures in R1, R2 and R3 in the isocyanate monomer is preferably ≤5, for example, the total number of cyclic structures is 2, 3, 4 or 5.

[0045] The maleimide resin of the present invention preferably contains two or more aromatic groups in its molecular structure, so that the molecular chain contains multiple rigid groups, which can improve the rigidity of the maleimide resin, inhibit the movement of chain segments, and thus help reduce the CTE of the prepolymer resin.

[0046] Optionally, the aromatic group can be selected from a monocyclic aromatic group or a polycyclic aromatic group, for example, preferably phenyl, naphthyl, anthracenyl, etc.

[0047] In order to further improve the CTE and water absorption of the prepolymer resin, the number of aromatic groups in the molecular structure of the maleimide resin is preferably ≤5, for example, the number of aromatic groups is 2, 3, 4 or 5, and / or the aromatic group is preferably a six-membered ring structure, for example, the six-membered ring structure is phenyl, naphthyl or anthracene.

[0048] Optionally, the maleimide resin is preferably at least one of biphenyl bismaleimide, biscyclopentadienyl bismaleimide, dimethyl diethyl bismaleimide, phenyl ether bismaleimide, meta-phenyl maleimide, oligomeric biphenyl maleimide or methylene maleimide.

[0049] The present invention preferably adopts the polymerization of isocyanate self-polymer and maleimide resin to obtain prepolymer resin, wherein the isocyanate self-polymer is obtained by self-polymerization of the above-mentioned isocyanate monomer, and the weight ratio of the isocyanate monomer to the maleimide resin is preferably 0.1:1-10:1, and more preferably 0.5:1-3:1, thereby further ensuring the prepolymerization effect and achieving the low CTE and low water absorption effect of the prepolymer resin.

[0050] The cyanate self-polymer of the present invention is preferably a self-polymerization product of a cyanate monomer having a molecular structure as shown in formula (II):

[0051]

[0052] Among them, R4 and R6 are independently selected from a saturated alkyl chain, an unsaturated alkyl chain, a five-membered cyclic structure or a six-membered cyclic structure, R5 is selected from a cyclic structure, and m≤5. By selecting a cyanate ester monomer containing a polycyclic structure, the polymerization efficiency of the cyanate ester monomer when self-polymerizing into a cyanate ester self-polymer can be improved, which is beneficial to further reduce the cyanate functional group content in the cyanate self-polymer, thereby reducing the water absorption of the circuit substrate. In addition, the cyanate ester monomer molecules containing a polycyclic structure have good heat resistance, which can further reduce the CTE of the circuit substrate.

[0053] The present invention also provides a method for preparing the prepolymer resin, comprising the following steps:

[0054] S1, providing a self-polymer, wherein the self-polymer is selected from an isocyanate self-polymer and / or a cyanate self-polymer, wherein the preparation method of the isocyanate self-polymer comprises: mixing an isocyanate monomer, a metal salt catalyst, and a solvent, and heating to carry out a self-polymerization reaction to obtain the isocyanate self-polymer; the preparation method of the cyanate self-polymer comprises: mixing a cyanate monomer, a metal salt catalyst, and a solvent, and heating to carry out a self-polymerization reaction to obtain the cyanate self-polymer;

[0055] S2, reacting the self-polymer with maleimide resin to obtain a prepolymer resin.

[0056] In step S1, in the method for preparing the isocyanate self-polymer, the amount of the metal salt catalyst is preferably 0.05wt%-1wt% of the amount of the isocyanate monomer, the temperature of the self-polymerization reaction is preferably 100°C-200°C, and the time is preferably 12h-48h; in the method for preparing the cyanate self-polymer, the amount of the metal salt catalyst is preferably 0.05wt%-1wt% of the amount of the cyanate monomer, the temperature of the self-polymerization reaction is preferably 100°C-200°C, and the time is preferably 12h-48h.

[0057] Optionally, the metal salt catalyst is preferably a catalyst containing metal ions such as zinc and cobalt.

[0058] In step S2, the maleimide can react with an isocyanate self-polymer to form a prepolymer resin, can react with a cyanate self-polymer to form a prepolymer resin, or can react with an isocyanate self-polymer and a cyanate self-polymer to form a prepolymer resin. In the present invention, the maleimide resin is preferably added to the isocyanate self-polymer for reaction. It is understood that the solvent for the reaction of the maleimide resin and the isocyanate self-polymer is the same as the solvent in step S1. The temperature for the reaction of the maleimide resin and the isocyanate self-polymer is preferably 100° C. to 200° C., and the reaction time is preferably 1 hour to 18 hours.

[0059] The present invention also provides a resin composition comprising the prepolymerized resin and an initiator.

[0060] Optionally, the amount of the prepolymer resin is preferably 50 parts by weight to 90 parts by weight, and the amount of the initiator is preferably 0.001 parts by weight to 0.1 parts by weight.

[0061] Optionally, the initiator is preferably at least one of a peroxide, an azo or a polycarbonate initiator, for example, at least one of a peroxyester, hexane peroxide, azobisisobutyronitrile or diisopropylamine.

[0062] In one embodiment, the resin composition further includes a curing agent. Based on the amount of the prepolymer resin being 50 parts by weight to 90 parts by weight, the amount of the curing agent is preferably 1 part by weight to 10 parts by weight; the curing agent is preferably at least one of a polyene-based curing agent, a phenolic curing agent, or a benzoxazine curing agent, and is further preferably a polyene-based curing agent, such as a polyene-based curing agent such as trivinylbenzene, so that the curing agent has high activity, is easy to undergo cross-linking reaction with the double bonds in the prepolymer resin, enhances the cross-linking density, and can further reduce the water absorption of the prepolymer resin.

[0063] In one embodiment, the resin composition further includes an auxiliary functional resin. Based on the amount of the prepolymer resin being 50 parts by weight to 90 parts by weight, the amount of the auxiliary functional resin is preferably 1 part by weight to 40 parts by weight; the auxiliary functional resin is preferably a resin that can increase the toughness of the circuit substrate, such as a polyolefin resin, specifically selected from at least one of styrene-butadiene copolymer or epoxidized polybutadiene, and / or a resin that can improve the dielectric properties of the circuit substrate, such as a polyphenylene ether resin, specifically selected from a polyphenylene ether resin terminated with a carbon-carbon double bond.

[0064] In one embodiment, the resin composition further comprises a filler. Based on the prepolymer resin being used in an amount of 50 to 90 parts by weight, the filler is preferably used in an amount of 50 to 270 parts by weight. The present invention does not impose any specific restrictions on the specific type of the filler. Preferably, the filler can be selected from at least one of silicon dioxide and titanium dioxide. The filler can also be surface-treated with a silane coupling agent to increase compatibility with the other components.

[0065] The present invention also provides a prepreg made using the resin composition. The present invention does not limit the specific method for preparing the prepreg using the resin composition. Preferably, the prepreg is obtained by impregnating or coating a reinforcing material with the resin composition and drying the reinforcing material. The reinforcing material is preferably at least one of glass fiber cloth, aramid cloth, or carbon fiber cloth.

[0066] The present invention also provides a circuit substrate made of the semi-cured sheet, comprising an insulating layer and a conductive layer arranged on at least one surface of the insulating layer, wherein the insulating layer is pressed from one or more superimposed semi-cured sheets as described above, and the conductive layer is preferably copper foil.

[0067] The present invention also provides a printed circuit board made of the circuit substrate, so that the printed circuit board has a low CTE, does not have the problem of board explosion, and has excellent performance.

[0068] The printed circuit board is preferably manufactured by subjecting the circuit substrate to processes such as drilling, hole filling, micro-etching, pre-preg, activation, acceleration, chemical copper and copper thickening.

[0069] Hereinafter, the prepolymer resin and its preparation method and application will be further described through the following specific examples.

[0070] Example 1

[0071] 40 parts by weight of an isocyanate monomer and 0.2 parts by weight of a metal salt catalyst are mixed in butanone and reacted at 160° C. for 15 hours to obtain an isocyanate self-polymer, wherein the degree of polymerization of the isocyanate self-polymer is 15, and the molecular structure of the isocyanate monomer is shown in formula (I), wherein R1 is a methylene group, R2 is a methylene group, R3 is a phenyl group, and n is 3.

[0072] 70 parts by weight of biphenyl bismaleimide was added to the above-mentioned isocyanate homopolymer, and the mixture was reacted at 120° C. for 12 hours to obtain a prepolymer resin, wherein the mass ratio of the isocyanate monomer to the maleimide resin was 0.57:1, and the double bond equivalent of the prepolymer resin was 310 g / mol.

[0073] 75 parts by weight of prepolymer resin, 0.02 parts by weight of dicumyl peroxide, 200 parts by weight of spherical silica, and 10 parts by weight of benzoxazine curing agent were mixed in a mixed solvent of butanone / dimethylacetamide and stirred at 500 rpm / min at room temperature for 10 hours to obtain a resin composition. The resin composition was then dip-coated onto 1080E fiberglass cloth and baked to form a prepreg. Two prepregs were stacked, coated on both sides with copper foil, and pressed in a hot press for 2 hours to obtain a circuit substrate.

[0074] The test performances of CTE and water absorption of the circuit substrate of this embodiment are shown in Table 1.

[0075] Example 2

[0076] 60 parts by weight of an isocyanate monomer and 0.3 parts by weight of a metal salt catalyst are mixed in butanone and reacted at 160° C. for 15 hours to obtain an isocyanate self-polymer, wherein the degree of polymerization of the isocyanate self-polymer is 15, and the molecular structure of the isocyanate monomer is shown in formula (I), wherein R1 is a methylene group, R2 is an alkenyl group, R3 is a phenyl group, and n is 3.

[0077] 60 parts by weight of biscyclopentadienyl bismaleimide was added to the above-mentioned isocyanate homopolymer, and the mixture was reacted at 120° C. for 12 hours to obtain a prepolymer resin, wherein the mass ratio of the isocyanate monomer to the maleimide resin was 1:1, and the double bond equivalent of the prepolymer resin was 240 g / mol.

[0078] 75 parts by weight of prepolymer resin, 0.02 parts by weight of dicumyl peroxide, and 10 parts by weight of benzoxazine curing agent were mixed in a mixed solvent of butanone / dimethylacetamide and stirred at 500 rpm / min at room temperature for 10 hours to obtain a resin composition. The resin composition was then dip-coated onto 1080E fiberglass cloth and baked to form a prepreg. Two prepregs were stacked, coated on both sides with copper foil, and pressed in a hot press for 2 hours to obtain a circuit substrate.

[0079] The test performances of CTE and water absorption of the circuit substrate of this embodiment are shown in Table 1.

[0080] Example 3

[0081] 60 parts by weight of an isocyanate monomer and 0.3 parts by weight of a metal salt catalyst are mixed in butanone, and the mixture is reacted at 160° C. for 15 hours to obtain an isocyanate self-polymer, wherein the degree of polymerization of the isocyanate self-polymer is 15, and the molecular structure of the isocyanate monomer is shown in formula (I), wherein R1 is a methylene group, R2 is a cyclohexyl group, R3 is a phenyl group, and n is 3.

[0082] 30 parts by weight of dimethyl diethyl bismaleimide was added to the above-mentioned isocyanate homopolymer, and the mixture was reacted at 120° C. for 12 hours to obtain a prepolymer resin, wherein the mass ratio of the isocyanate monomer to the maleimide resin was 2:1, and the double bond equivalent of the prepolymer resin was 190 g / mol.

[0083] 75 parts by weight of prepolymer resin, 0.02 parts by weight of dicumyl peroxide, 30 parts by weight of polybutadiene, 200 parts by weight of angular silica, and 10 parts by weight of benzoxazine curing agent were mixed in a mixed solvent of butanone / dimethylacetamide and stirred at 500 rpm / min at room temperature for 10 hours to obtain a resin composition. The resin composition was then dip-coated onto 1080E fiberglass cloth and baked to form a prepreg. Two prepregs were stacked, coated on both sides with copper foil, and pressed on a hot press for 2 hours to obtain a circuit substrate.

[0084] The test performances of CTE and water absorption of the circuit substrate of this embodiment are shown in Table 1.

[0085] Example 4

[0086] 90 parts by weight of an isocyanate monomer and 0.45 parts by weight of a metal salt catalyst are mixed in butanone and reacted at 160° C. for 15 hours to obtain an isocyanate self-polymer, wherein the degree of polymerization of the isocyanate self-polymer is 10, and the molecular structure of the isocyanate monomer is shown in formula (I), wherein R1 is a methylene group, R2 is a phenyl group, R3 is a phenyl group, and n is 3.

[0087] 30 parts by weight of phenylene ether bismaleimide was added to the above-mentioned isocyanate homopolymer, and the mixture was reacted at 120° C. for 12 hours to obtain a prepolymer resin, wherein the mass ratio of the isocyanate monomer to the maleimide resin was 3:1, and the double bond equivalent of the prepolymer resin was 170 g / mol.

[0088] 75 parts by weight of prepolymer resin, 0.02 parts by weight of dicumyl peroxide, 30 parts by weight of styrene-butadiene copolymer, 200 parts by weight of spherical silica, and 10 parts by weight of trivinylbenzene curing agent were mixed in a mixed solvent of butanone / dimethylacetamide and stirred at 500 rpm / min at room temperature for 10 hours to obtain a resin composition. The resin composition was then dip-coated onto 1080E fiberglass cloth and baked to form a prepreg. Two prepregs were stacked, coated on both sides with copper foil, and pressed on a hot press for 2 hours to obtain a circuit substrate.

[0089] The test results of the CTE, water absorption and board burst test of the circuit substrate of this embodiment are shown in Table 1.

[0090] Table 1

[0091] Water absorption CTE T288 explosion board Example 1 0.21 9 Unexploded board Example 2 0.34 10.7 Unexploded board Example 3 0.23 8.5 Unexploded board Example 4 0.25 9 Unexploded board

[0092] Example 5

[0093] The difference between Example 5 and Example 1 is that 40 parts by weight of isocyanate self-polymer is replaced with 40 parts by weight of cyanate self-polymer, wherein the molecular structure of the cyanate monomer that self-polymerizes into the cyanate self-polymer is as shown in Formula (II), R4 is selected from methylene, R5 is selected from phenyl, R6 is selected from methylene, and m is 3.

[0094] The test results of the CTE, water absorption and board burst test of the circuit substrate of this embodiment are shown in Table 2.

[0095] Example 6

[0096] The difference between Example 6 and Example 1 is that 40 parts by weight of the isocyanate self-polymer is replaced with 20 parts by weight of the cyanate self-polymer and 20 parts by weight of the isocyanate self-polymer, wherein the isocyanate self-polymer remains the same as in Example 1, and the molecular structure of the cyanate monomer that self-polymerizes into the cyanate self-polymer is shown in Formula (II), R4 is selected from methylene, R5 is selected from phenyl, R6 is selected from methylene, and m is 3.

[0097] The test results of the CTE, water absorption and board burst test of the circuit substrate of this embodiment are shown in Table 2.

[0098] Table 2

[0099] Water absorption CTE T288 explosion board Example 5 0.33 9.9 Unexploded board Example 6 0.45 9.3 Unexploded board

[0100] Example 7

[0101] The difference between Example 7 and Example 1 is that the amount of isocyanate monomer is 350 parts by weight, the amount of biphenyl bismaleimide resin is 35 parts by weight, and the amount of metal salt catalyst is 1.75 parts by weight, wherein the degree of polymerization of the isocyanate self-polymer is 19, the mass ratio of isocyanate monomer to maleimide resin is 10:1, and the double bond equivalent of the prepolymer resin is 150 g / mol.

[0102] The test results of the CTE, water absorption and board burst test of the circuit substrate of this embodiment are shown in Table 3.

[0103] Table 3

[0104] Water absorption CTE T288 explosion board Example 7 0.42 9.5 Unexploded board

[0105] Example 8

[0106] The difference between Example 8 and Example 1 is that the molecular structure of the isocyanate monomer is as shown in Formula (I), wherein R1 is a methylene group, R2 is a methylene group, R3 is a phenyl group, n is 6, the degree of polymerization of the isocyanate self-polymer is 6, and the double bond equivalent of the prepolymer resin is 250 g / mol.

[0107] The test results of the CTE, water absorption and board burst test of the circuit substrate of this embodiment are shown in Table 4.

[0108] Example 9

[0109] The difference between Example 9 and Example 1 is that the molecular structure of the isocyanate monomer is as shown in Formula (I), wherein R1 is an ether group, R2 is an ether group, R3 is a methylene group, n is 3, the degree of polymerization of the isocyanate self-polymer is 10, and the double bond equivalent of the prepolymer resin is 310 g / mol.

[0110] The test results of the CTE, water absorption and board burst test of the circuit substrate of this embodiment are shown in Table 4.

[0111] Table 4

[0112] Water absorption CTE T288 explosion board Example 8 0.48 10.2 Unexploded board Example 9 0.36 9.4 Unexploded board

[0113] Example 10

[0114] The difference between Example 10 and Example 1 is that the molecular structure of the isocyanate monomer is as shown in Formula (I), wherein R1 is a methylene group, R2 is a methylene group, R3 is a dicyclopentadienyl group, and the number of ring structures is 6, n is 3, the degree of polymerization of the isocyanate self-polymer is 10, and the double bond equivalent of the prepolymer resin is 290 g / mol.

[0115] The test results of the CTE, water absorption and board burst test of the circuit substrate of this embodiment are shown in Table 5.

[0116] Table 5

[0117] Water absorption CTE T288 explosion board Example 10 0.31 9.5 Unexploded board

[0118] Example 11

[0119] The difference between Example 11 and Example 1 is that the maleimide resin is selected from m-phenylmaleimide having 1 aromatic group, and the double bond equivalent of the prepolymer resin is 250 g / mol.

[0120] The test results of the CTE, water absorption and board burst test of the circuit substrate of this embodiment are shown in Table 6.

[0121] Table 6

[0122] Water absorption CTE T288 explosion board Example 11 0.35 10.4 Unexploded board

[0123] Example 12

[0124] The difference between Example 12 and Example 1 is that the maleimide resin is selected from oligomeric biphenyl maleimide having 10 aromatic groups and a degree of polymerization of 5, and the double bond equivalent of the prepolymer resin is 340 g / mol.

[0125] The test results of the CTE, water absorption and board burst test of the circuit substrate of this embodiment are shown in Table 7.

[0126] Example 13

[0127] The difference between Example 13 and Example 1 is that the maleimide resin is selected from methylenemaleimide, and the double bond equivalent of the prepolymer resin is 320 g / mol.

[0128] The test results of the CTE, water absorption and board burst test of the circuit substrate of this embodiment are shown in Table 7.

[0129] Table 7

[0130] Water absorption CTE T288 explosion board Example 12 0.28 9.6 Unexploded board Example 13 0.47 10.6 Unexploded board

[0131] Example 14

[0132] The difference between Example 14 and Example 1 is that the amount of isocyanate monomer is 6 parts by weight, the amount of maleimide resin is 70 parts by weight, the amount of metal salt catalyst is 0.03 parts by weight, the mass ratio of isocyanate monomer to maleimide resin is 0.08:1, and the double bond equivalent of the prepolymer resin is 370 g / mol.

[0133] The test results of the CTE, water absorption and board burst test of the circuit substrate of this embodiment are shown in Table 8.

[0134] Example 15

[0135] The difference between Example 15 and Example 1 is that the amount of isocyanate monomer is 525 parts by weight, the amount of maleimide resin is 35 parts by weight, the amount of metal salt catalyst is 2.625 parts by weight, the mass ratio of isocyanate monomer to maleimide resin is 15:1, and the double bond equivalent of the prepolymer resin is 110 g / mol.

[0136] The test results of the CTE, water absorption and board burst test of the circuit substrate of this embodiment are shown in Table 8.

[0137] Table 8

[0138] Water absorption CTE T288 explosion board Example 14 0.28 10.8 Unexploded board Example 15 0.49 10.8 Unexploded board

[0139] Comparative Example 1

[0140] The difference between Comparative Example 1 and Example 1 is that the degree of polymerization of the isocyanate self-polymer is 25, and the double bond equivalent of the prepolymer resin is 550 g / mol.

[0141] The test results of the CTE, water absorption and board burst test of the circuit substrate of this comparative example are shown in Table 9.

[0142] Comparative Example 2

[0143] 40 parts by weight of an isocyanate monomer and 70 parts by weight of a maleimide resin are mixed in butanone and reacted at 120° C. for 12 hours to obtain a prepolymer resin, wherein the molecular structure of the isocyanate monomer is as shown in formula (I), wherein R1 is a methylene group, R2 is a methylene group, R3 is a phenyl group, n is 3, the maleimide resin is selected from biphenyl bismaleimide, the mass ratio of the isocyanate monomer to the maleimide resin is 0.57:1, and the double bond equivalent of the prepolymer resin is 650 g / mol.

[0144] 75 parts by weight of prepolymer resin, 0.02 parts by weight of dicumyl peroxide, 200 parts by weight of spherical silica, and 10 parts by weight of benzoxazine curing agent were mixed in a mixed solvent of butanone / dimethylacetamide and stirred at 500 rpm / min at room temperature for 10 hours to obtain a resin composition. The resin composition was then dip-coated onto 1080E fiberglass cloth and baked to form a prepreg. Two prepregs were stacked and pressed in a hot press for 2 hours to obtain a circuit substrate.

[0145] The test results of the CTE, water absorption and board burst test of the circuit substrate of this comparative example are shown in Table 9.

[0146] Table 9

[0147] Water absorption CTE T288 explosion board Comparative Example 1 0.83 13.2 Explosion Comparative Example 2 1.42 13.6 Explosion

[0148] In the above embodiments and comparative examples, the CTE, water absorption and board burst test methods of the circuit substrate are as follows:

[0149] CTE:IPC-TM650-2.4.41.

[0150] Water absorption: GB / T4722-2017-9.2.

[0151] T288 rupture: IPC-TM-650-2.4.24.1.

[0152] The circuit substrate prepared in the above embodiment has a water absorption rate of less than 0.5%, a CTE of less than 12, and no board explosion problem occurs, indicating excellent performance.

[0153] 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.

[0154] 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 prepolymer resin, characterized in that The prepolymer resin is a polymerization product of a self-polymer and a maleimide resin, wherein the self-polymer is selected from an isocyanate self-polymer and / or a cyanate self-polymer, and the polymerization degree of the isocyanate self-polymer and the cyanate self-polymer are both less than 20.

2. The prepolymer resin according to claim 1, wherein The double bond equivalent of the prepolymer resin is ≤500 g / mol.

3. The prepolymer resin according to claim 1, wherein The isocyanate self-polymer is a self-polymerization product of an isocyanate monomer having a molecular structural formula as shown in formula (I): wherein R1 and R2 are independently selected from a saturated alkyl chain, an unsaturated alkyl chain, a five-membered cyclic structure or a six-membered cyclic structure, R3 is selected from a cyclic structure, and n≤5; And / or, the cyanate self-polymer is a self-polymerization product of a cyanate monomer having a molecular structure as shown in formula (II): Wherein, R4 and R6 are independently selected from a saturated alkyl chain, an unsaturated alkyl chain, a five-membered cyclic structure or a six-membered cyclic structure, R5 is selected from a cyclic structure, and m≤5.

4. The prepolymer resin according to claim 3, characterized in that In the isocyanate monomer, the total number of cyclic structures in R1, R2 and R3 is ≤5.

5. The prepolymer resin according to claim 1, characterized in that The maleimide resin contains two or more aromatic groups in its molecular structure.

6. The prepolymer resin according to claim 5, characterized in that In the molecular structure of the maleimide resin, the number of aromatic groups is ≤5; And / or, the aromatic group is selected from a six-membered ring structure.

7. The prepolymer resin according to any one of claims 3 to 6, characterized in that The mass ratio of the isocyanate monomer to the maleimide resin is 0.1:1-10:

1.

8. A method for preparing a prepolymer resin according to any one of claims 1 to 7, characterized in that: The following steps are involved: Provided is a self-polymer selected from an isocyanate self-polymer and / or a cyanate self-polymer, wherein a method for preparing the isocyanate self-polymer comprises: mixing an isocyanate monomer, a metal salt catalyst, and a solvent, and heating to carry out a self-polymerization reaction to obtain the isocyanate self-polymer; and a method for preparing the cyanate self-polymer comprises: mixing a cyanate monomer, a metal salt catalyst, and a solvent, and heating to carry out a self-polymerization reaction to obtain the cyanate self-polymer; The self-polymer is reacted with maleimide resin to obtain a prepolymer resin.

9. The method for preparing a prepolymer resin according to claim 8, wherein In the step of self-polymerization, the reaction temperature is 100°C-200°C, and the reaction time is 12h-48h; And / or, in the step of reacting the self-polymer with maleimide resin, the reaction temperature is 100° C.-200° C., and the reaction time is 1 hour-18 hours.

10. A resin composition, characterized in that The method comprises the prepolymer resin according to any one of claims 1 to 7 and an initiator.

11. The resin composition according to claim 10, characterized in that The amount of the prepolymer resin used is 50 parts by weight to 90 parts by weight, and the amount of the initiator used is 0.001 parts by weight to 0.1 parts by weight.

12. The resin composition according to claim 11, characterized in that The resin composition further comprises a curing agent, wherein the amount of the curing agent is 1 part by weight to 10 parts by weight; And / or, the resin composition further comprises an auxiliary functional resin, wherein the amount of the auxiliary functional resin is 1 part by weight to 40 parts by weight; And / or, the resin composition further comprises a filler, and the amount of the filler is 50 parts by weight to 270 parts by weight.

13. The resin composition according to claim 12, characterized in that The auxiliary functional resin is selected from at least one of polyolefin resin and polyphenylene ether resin.

14. A prepreg made from the resin composition according to any one of claims 10 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.

Images