Resin glue solution and preparation method thereof, prepreg, circuit substrate and printed circuit board

Abstract

The invention relates to a resin glue solution and a preparation method thereof, a prepreg, a circuit substrate and a printed circuit board. The resin glue solution comprises unsaturated double-bond resin, an assistant cross-linking agent, a low-temperature initiator, a high-temperature initiator and a solvent, or the resin glue solution comprises a pre-polymerized resin composition and a high-temperature initiator, and the pre-polymerized resin composition is obtained by incomplete reaction of the unsaturated double-bond resin, the low-temperature initiator and the assistant cross-linking agent in the solvent; wherein the molar content of vinyl in the assistant cross-linking agent is 2%-5%, the molecular weight of the assistant cross-linking agent is 180-380, the optimal active temperature of the low-temperature initiator is 60-90 DEG C, the molecular weight of the low-temperature initiator is 120-400, the optimal active temperature of the high-temperature initiator is 140-220 DEG C, and the molecular weight of the high-temperature initiator is 140-400. The circuit substrate prepared from the resin glue solution can meet the high-performance use requirements of peel strength attenuation rate and dielectric property uniformity after aging.

Description

Technical Field

[0001] The invention relates to the technical field of electronic industry, and in particular to a resin glue solution and a preparation method thereof, a prepreg, a circuit substrate and a printed circuit board. Background Art

[0002] Unsaturated double bond resins are widely used in copper clad laminates in the high frequency field due to their good electrical properties. However, related processes are required in the subsequent PCB processing, which leads to a high temperature at the interface of the board. As a result, the copper clad laminates made of traditional unsaturated double bond resins have a weakened bond between the substrate and the copper foil at high temperatures, resulting in a decrease in peel strength.

[0003] By using a low-temperature initiator, the resin composition can be partially cross-linked before lamination, thereby increasing the cross-linking density of the resin glue. However, due to the high activity of the low-temperature initiator, the reaction is uncontrollable, which will cause uneven reactions in various parts of the resin glue, resulting in poor uniformity of the dielectric properties of the board. Summary of the invention

[0004] Based on this, it is necessary to provide a resin glue and its preparation method, a semi-cured sheet, a circuit substrate and a printed circuit board to address the above problems; the circuit substrate prepared using the resin glue can meet the high-performance usage requirements of the peel strength attenuation rate after aging and the uniformity of dielectric properties.

[0005] A resin glue solution, comprising an unsaturated double bond resin, a co-crosslinking agent, a low temperature initiator, a high temperature initiator and a solvent, or comprising a prepolymer resin composition and a high temperature initiator, wherein the prepolymer resin composition is obtained by incompletely reacting the unsaturated double bond resin, the low temperature initiator and the co-crosslinking agent in a solvent;

[0006] The vinyl molar content of the auxiliary crosslinking agent is 2%-5%, and the molecular weight is 180-380. The optimal active temperature of the low-temperature initiator is 60°C-90°C, and the molecular weight is 120-400. The optimal active temperature of the high-temperature initiator is 140°C-220°C, and the molecular weight is 140-400.

[0007] In one embodiment, the reaction degree of the prepolymer resin composition is 15%-25%;

[0008] And / or, the viscosity of the prepolymer resin composition is 300 mPa·s-400 mPa·s.

[0009] In one embodiment, based on 100 parts by weight of the unsaturated double bond resin, the auxiliary cross-linking agent is 2 parts by weight to 6 parts by weight, the low-temperature initiator is 1 part by weight to 5 parts by weight, and the high-temperature initiator is 1 part by weight to 5 parts by weight.

[0010] In one embodiment, the molar content of vinyl in the unsaturated double bond resin is 40%-60%;

[0011] And / or, the unsaturated double bond resin is selected from at least one of hydrocarbon resin, unsaturated polyester and unsaturated polyether.

[0012] In one embodiment, the low temperature initiator is selected from at least one of dibenzoyl peroxide, bis(4-tert-butylcyclohexyl) peroxydicarbonate, and azobisisobutyronitrile.

[0013] In one embodiment, the high temperature initiator is selected from at least one of di-tert-butyl peroxide isopropylbenzene, di-tert-butyl peroxide, di-tert-butyl peroxide, diisopropylbenzene peroxide, and isopropylbenzene hydroperoxide.

[0014] A method for preparing the resin glue as described above comprises:

[0015] Mixing an unsaturated double-bond resin, a cross-linking aid, a low-temperature initiator, a high-temperature initiator and a solvent to obtain a resin glue solution;

[0016] Alternatively, the unsaturated double bond resin, the low temperature initiator and the auxiliary cross-linking agent are reacted incompletely in a solvent to obtain a prepolymer resin composition, and then the prepolymer resin composition is mixed with a high temperature initiator to obtain a resin glue solution.

[0017] In one embodiment, the incomplete reaction is carried out in an inert gas atmosphere and / or at 40° C.-70° C.

[0018] A prepreg comprises a reinforcing material and a resin composition layer attached to the reinforcing material, wherein the resin composition layer is obtained by drying the resin glue solution as described above.

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

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

[0021] In the resin adhesive of the present invention, a co-crosslinking agent with a specific vinyl molar content and molecular weight, a low-temperature initiator with a specific optimal activity temperature and molecular weight, and a high-temperature initiator with a specific optimal activity temperature and molecular weight are compounded for use. On the one hand, the reaction activity of the co-crosslinking agent is improved, the double bond residues in the unsaturated double bond resin are reduced, and it is also beneficial to reduce the initiator residues, thereby improving the crosslinking density of the resin composition layer; on the other hand, in the lamination stage of preparing the circuit substrate, the components in the resin adhesive are further crosslinked, thereby ensuring that the resin composition layer has a higher crosslinking density, further reducing the double bond residues in the unsaturated double bond resin, and reducing the oxidation risk, so that the circuit substrate can meet the high-performance use requirements of the peel strength attenuation rate after aging and the uniformity of dielectric properties.

[0022] In addition, by utilizing the incomplete reaction of the unsaturated double bond resin, the low-temperature initiator, and the auxiliary cross-linking agent, the unsaturated double bond resin in the prepolymer resin composition can have a higher molecular weight lower limit and a narrower molecular weight distribution, and the prepolymer resin composition has a certain degree of reaction, and the degree of each part is equivalent, which is more conducive to improving the uniformity of the dielectric properties of the circuit substrate and reducing the peel strength attenuation rate after aging. DETAILED DESCRIPTION

[0023] For ease of 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.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific implementation methods or embodiments and are not intended to limit the present invention.

[0025] The present invention provides a resin glue solution, comprising an unsaturated double bond resin, a co-crosslinking agent, a low temperature initiator, a high temperature initiator and a solvent, or comprising a prepolymer resin composition and a high temperature initiator, wherein the prepolymer resin composition is obtained by incompletely reacting the unsaturated double bond resin, the low temperature initiator and the co-crosslinking agent in a solvent;

[0026] The vinyl molar content of the auxiliary crosslinking agent is 2%-5%, and the molecular weight is 180-380. The optimal active temperature of the low-temperature initiator is 60°C-90°C, and the molecular weight is 120-400. The optimal active temperature of the high-temperature initiator is 140°C-220°C, and the molecular weight is 140-400.

[0027] By compounding a co-crosslinking agent with a specific vinyl molar content and molecular weight, a low-temperature initiator with a specific optimal activity temperature and molecular weight, and a high-temperature initiator with a specific optimal activity temperature and molecular weight, on the one hand, the reaction activity of the co-crosslinking agent is improved, the double bond residue in the unsaturated double bond resin is reduced, and it is also beneficial to reduce the initiator residue, thereby increasing the crosslinking density of the resin composition layer and reducing the peel strength attenuation rate of the circuit substrate after aging.

[0028] On the other hand, during the lamination stage of preparing the circuit substrate, the components in the resin glue undergo further cross-linking, thereby ensuring that the resin composition layer has a higher cross-linking density, further reducing the residual double bonds in the unsaturated double bond resin, and reducing the risk of oxidation, so that the circuit substrate can meet the high-performance usage requirements of the peel strength attenuation rate after aging and the uniformity of dielectric properties.

[0029] In addition, by utilizing the incomplete reaction of the unsaturated double bond resin, the low-temperature initiator, and the auxiliary cross-linking agent, the unsaturated double bond resin in the prepolymer resin composition can have a higher molecular weight lower limit and a narrower molecular weight distribution, and the prepolymer resin composition has a certain degree of reaction, and the degree of each part is equivalent, which is more conducive to improving the uniformity of the dielectric properties of the circuit substrate and reducing the peel strength attenuation rate after aging.

[0030] Among them, it is preferred that the reaction degree of the prepolymer resin composition is 15%-25%, and / or the viscosity of the prepolymer resin composition is 300mPa·s-400mPa·s. Within this reaction degree, the distribution of vinyl content in each part of the prepolymer glue is relatively close, the reaction degree span before and after the semi-cured sheet is pressed is narrow, and the difference in residual vinyl content in each part of the circuit substrate is small, which is more conducive to improving the uniformity of the dielectric properties of the circuit substrate and reducing the peel strength attenuation rate after aging.

[0031] Preferably, the molar vinyl content of the unsaturated double bond resin is 40%-60%, which can not only make the unsaturated double bond resin more reactive, but also help to improve the crosslinking density of the resin composition layer, improve the uniformity of the dielectric properties of the circuit substrate, thereby enhancing the peel strength of the circuit substrate prepared by pressing, but also reduce the double bonds remaining in the unsaturated double bond resin, reduce the risk of oxidation, and reduce the peel strength attenuation rate of the circuit substrate after aging.

[0032] Specifically, the unsaturated double bond resin is selected from at least one of hydrocarbon resin, unsaturated polyester and unsaturated polyether, and is preferably hydrocarbon resin.

[0033] The hydrocarbon resin includes but is not limited to at least one of polybutadiene, polystyrene, styrene-butadiene-styrene block copolymer, ethylene-propylene-diene copolymer, and hydrogenated styrene-butadiene block copolymer.

[0034] Through the synergistic effect of a low-temperature initiator with a specific optimal active temperature and molecular weight and a co-crosslinking agent with a specific vinyl content and molecular weight, the reaction activity can be improved, the crosslinking effect of the macromolecular chain can be enhanced, and the carbon-carbon double bond reaction in the unsaturated double bond resin that is difficult to participate in the reaction due to the spatial structure can be promoted, thereby increasing the crosslinking density, reducing double bond residues, reducing the peel strength attenuation rate of the circuit substrate after aging, and improving the uniformity of the dielectric properties of the circuit substrate.

[0035] Preferably, the vinyl molar content of the auxiliary cross-linking agent is 3%-4% and the molecular weight is 260-360.

[0036] Specifically, the auxiliary cross-linking agent includes but is not limited to at least one of trimethylolpropane triacrylate (TMPTA), trimethylolpropane trimethacrylate (TMPTMA), N,N′-m-phenylene bismaleimide (HAV-2), triallyl cyanurate (TAC), triallyl isocyanurate (TAIC), and diallyl 1,2-phthalate (DAP).

[0037] Preferably, the optimal active temperature of the low-temperature initiator is 70°C-85°C and the molecular weight is 160-260.

[0038] Specifically, the low-temperature initiator includes but is not limited to at least one of dibenzoyl peroxide (BPO), bis(4-tert-butylcyclohexyl) peroxydicarbonate (TBCP), and azobisisobutyronitrile (AIBN).

[0039] In one embodiment, the molecular weight of the high temperature initiator is preferably greater than that of the low temperature initiator, which is beneficial to further increase the crosslinking density of the resin composition layer and reduce the residual double bonds in the unsaturated double bond resin.

[0040] More preferably, the optimal active temperature of the high temperature initiator is 160°C-180°C and the molecular weight is 140-340.

[0041] Specifically, the high temperature initiator includes but is not limited to at least one of di-tert-butyl peroxide isopropylbenzene (BIPB), di-tert-butyl peroxide (DTBP), di-tert-butyl peroxide, diisopropylbenzene peroxide (DCP), and cumene hydroperoxide (CHP).

[0042] It should be noted that the optimal activity temperature is determined based on the half-life of the initiator, that is, the optimal temperature at which the initiator decomposes to half of its initial mass within a certain period of time (1 hour).

[0043] The solvent is preferably a volatile organic solvent, including but not limited to xylene, toluene, and dimethylformamide, preferably xylene.

[0044] In one embodiment, the resin glue further includes a filler, which includes but is not limited to silicon dioxide, aluminum oxide, magnesium oxide, silicon nitride, preferably silicon dioxide, which is beneficial to reducing the coefficient of thermal expansion (CTE) of the circuit substrate and improving processability.

[0045] In one embodiment, based on 100 parts by weight of the unsaturated double bond resin, the auxiliary cross-linking agent is 2 parts by weight to 6 parts by weight, the low-temperature initiator is 1 part by weight to 5 parts by weight, the high-temperature initiator is 1 part by weight to 5 parts by weight, and the filler is 250 parts by weight to 350 parts by weight.

[0046] It should be noted that the resin glue also includes auxiliary agents such as coupling agents, which are not limited in the present invention, and those skilled in the art can add auxiliary agents according to actual preparation requirements.

[0047] When the resin glue includes an unsaturated double bond resin, a co-crosslinking agent, a low-temperature initiator, a high-temperature initiator and a solvent, the present invention provides a method for preparing the resin glue, comprising: mixing the unsaturated double bond resin, the co-crosslinking agent, the low-temperature initiator, the high-temperature initiator and the solvent to obtain the resin glue.

[0048] When the resin adhesive includes a prepolymer resin composition and a high-temperature initiator, the present invention provides another method for preparing the resin adhesive, comprising: incompletely reacting an unsaturated double-bond resin, a low-temperature initiator, and a co-crosslinking agent in a solvent to obtain a prepolymer resin composition, and then mixing the prepolymer resin composition with a high-temperature initiator to obtain a resin adhesive.

[0049] The incomplete reaction is preferably carried out in an inert gas atmosphere and / or at 40°C-70°C, preferably 40-50°C, which is more conducive to controlling the reaction degree of the unsaturated double bond resin, reducing the risk of implosion, and avoiding excessive reaction degree. The inert gas is preferably nitrogen.

[0050] Under the specific reaction temperature condition of 40°C-50°C, the low-temperature initiator has suitable initiation activity, which can cause partial cross-linking of the unsaturated double-bond resin, reduce the peel strength attenuation rate after aging of the circuit substrate, and help avoid the unsaturated double-bond resin in the subsequent baking process of preparing the semi-cured sheet. The temperature rises quickly and the cross-linking reaction is uncontrollable, resulting in different reaction degrees of each part in the resin composition layer, thereby further improving the uniformity of the dielectric properties of the circuit substrate.

[0051] More preferably, the incomplete reaction time at 40°C-50°C is 30 min-40 min.

[0052] It should be noted that, since the reaction conditions of the high temperature initiator are not met, the high temperature initiator is not limited to being added after the incomplete reaction, and the high temperature initiator can also be mixed with the unsaturated double bond resin, the low temperature initiator, the co-crosslinking agent and the solvent to directly obtain the resin glue after the incomplete reaction. The present invention is not limited to this, and the preparation method provided is a preferred solution, and those skilled in the art can also adjust it according to actual preparation needs.

[0053] The present invention provides a prepreg, comprising a reinforcing material and a resin composition layer attached to the reinforcing material, wherein the resin composition layer is obtained by drying the resin glue as described above.

[0054] Specifically, the reinforcing material is preferably glass fiber cloth, the drying temperature of the resin glue is higher than the optimal activity temperature of the low-temperature initiator and lower than the optimal activity temperature of the high-temperature initiator, preferably 78°C-90°C, and the drying time is preferably 350s-450s.

[0055] The present invention provides a circuit substrate made of the prepreg as described above.

[0056] The circuit substrate comprises a dielectric layer and a conductive layer disposed on at least one surface of the dielectric layer, wherein the dielectric layer is formed by pressing one or at least two superimposed prepregs as described above.

[0057] Specifically, the conductive layer includes but is not limited to copper foil, preferably copper foil.

[0058] The present invention also provides a printed circuit board made of the circuit substrate as described above.

[0059] In one embodiment, the printed circuit board is made of the circuit substrate through processes such as developing, etching, drilling, degumming, copper deposition, electroplating and pressing.

[0060] Hereinafter, the resin glue solution and its preparation method, prepreg, circuit substrate and printed circuit board will be further described through the following specific examples.

[0061] Example 1

[0062] Polybutadiene (weight average molecular weight 3000, vinyl molar content 40%, Jufeng Petrochemical A55RE) and ethylene propylene diene copolymer (DCPD:PE:PP=1:5:4, weight average molecular weight 45000, Kumho KEP650) were dissolved in xylene at a mass ratio of 6:4 (a total of 100 parts by weight). After complete dissolution and sampling, 1 part by weight of low-temperature initiator BPO (molecular weight 242, optimal activity temperature 72°C, Aksu TC-75W) and 3 parts by weight of cross-linking agent TMPTA (molecular weight 338, vinyl molar content 3.1%, Jinan Yuanxiang 895) were added. After nitrogen was introduced, the mixture was heated in a water bath at 45°C for 30 minutes. The viscosity of the prepolymerized resin composition was 324 mPa·s after sampling. The infrared spectrum of the sample before and after prepolymerization was tested, and the carbon-carbon double bond peak (1680 cm -1 -1620cm -1 ) area is S, according to the degree of reaction = 1-S 预聚后 / S 预聚前 The reaction degree was calculated to be 16%, the water bath was closed, and the prepolymerized resin composition was cooled under a nitrogen atmosphere while being stirred.

[0063] Add 300 parts by weight of angular silica to the prepolymer resin composition, disperse at high speed for 30 minutes, then add 3 parts by weight of vinyl trimethoxy silane coupling agent (Dow Corning DC6-1B) and 1.5 parts by weight of high-temperature initiator BIPB (molecular weight 338, optimal active temperature 141°C, Haosheng 14S-FL), continue stirring for 30 minutes and adjust the viscosity to obtain a resin adhesive.

[0064] Example 2

[0065] Polybutadiene (weight average molecular weight 3000, vinyl molar content 40%, Jufeng Petrochemical A55RE) and ethylene propylene diene copolymer (DCPD:PE:PP=1:5:4, weight average molecular weight 45000, Kumho KEP650) were dissolved in xylene at a mass ratio of 6:4 (a total of 100 parts by weight). After complete dissolution and sampling, 1 part by weight of low-temperature initiator BPO (molecular weight 242, optimal activity temperature 72°C, Aksu TC-75W) and 3 parts by weight of co-crosslinking agent TMPTA (molecular weight 338, vinyl molar content 3.1%, Jinan Yuanxiang 895) were added, and stirred at high speed for 30 minutes to obtain a mixture. The viscosity of the mixture was sampled and tested to be 218 mPa·s.

[0066] 300 parts by weight of angular silica were added to the mixture, and after high-speed dispersion for 30 minutes, 3 parts by weight of vinyl trimethoxy silane coupling agent (Dow Corning DC6-1B) and 1.5 parts by weight of high-temperature initiator BIPB (molecular weight 338, optimal active temperature 141°C, Haosheng 14S-FL) were added, and stirring was continued for 30 minutes to adjust the viscosity to obtain a resin adhesive solution.

[0067] Example 3

[0068] Polybutadiene (weight average molecular weight 3000, vinyl molar content 40%, Jufeng Petrochemical A55RE) and ethylene propylene diene copolymer (DCPD:PE:PP=1:5:4, weight average molecular weight 45000, Kumho KEP650) were dissolved in xylene at a mass ratio of 6:4 (a total of 100 parts by weight). After complete dissolution and sampling, 2 parts by weight of low-temperature initiator BPO (molecular weight 242, optimal activity temperature 72°C, Aksu TC-75W) and 4 parts by weight of cross-linking agent TAIC (molecular weight 249, vinyl molar content 2.8%, Ruituo EA-600) were added. After nitrogen was introduced, the mixture was heated in a water bath at 45°C for 30 minutes. The viscosity of the prepolymer resin composition was tested to be 350 mPa·s. The infrared spectrum of the samples before and after the prepolymerization was tested, and the reaction degree was calculated to be 18%. The water bath was closed and the prepolymer resin composition was cooled and stirred under a nitrogen atmosphere.

[0069] 350 parts by weight of angular silica were added to the prepolymer resin composition, and after high-speed dispersion for 30 minutes, 3 parts by weight of vinyl trimethoxy silane coupling agent (Dow Corning DC6-1B) and 2 parts by weight of high-temperature initiator DTBP (molecular weight 147, optimal active temperature 164°C, Akzo No. 3107) were added, and stirring was continued for 30 minutes to adjust the viscosity to obtain a resin adhesive.

[0070] Example 4

[0071] 100 parts by weight of polybutadiene (weight average molecular weight 3000, vinyl molar content 40%, Jufeng Petrochemical A55RE) were dissolved in xylene. After complete dissolution and sampling, 5 parts by weight of low-temperature initiator AIBN (molecular weight 164, optimal activity temperature 82°C, Shandong Hongle 785) and 6 parts by weight of cross-linking agent DAP (molecular weight 246, vinyl molar content 3%, Haochen HC-00007) were added. After nitrogen was introduced, the mixture was heated in a water bath at 45°C and reacted for 30 minutes. The viscosity of the prepolymer resin composition was tested by sampling and was found to be 380 mPa·s. The infrared spectrum of the sample before and after prepolymerization was tested, and the reaction degree was calculated to be 23%. The water bath was closed and the prepolymer resin composition was cooled and stirred in a nitrogen atmosphere.

[0072] 200 parts by weight of angular silica and 100 parts by weight of spherical silica were added to the prepolymer resin composition, and after high-speed dispersion for 30 minutes, 3 parts by weight of vinyl trimethoxy silane coupling agent (Dow Corning DC6-1B) and 3 parts by weight of high-temperature initiator CHP (molecular weight 152, optimal active temperature 166°C, Aksu K-90) were added, and stirring was continued for 30 minutes to adjust the viscosity to obtain a resin adhesive.

[0073] Example 5

[0074] The difference between Example 5 and Example 1 is that 6 parts by weight of low-temperature initiator BPO and 6 parts by weight of high-temperature initiator are added, the viscosity of the prepolymerized resin composition tested is 367 mPa·s, and the infrared spectrum of the samples before and after prepolymerization is tested, and the reaction degree is calculated to be 21%.

[0075] Example 6

[0076] The difference between Example 6 and Example 1 is that the reaction is carried out at the same temperature for 10 minutes, so that the reaction degree of the prepolymerized resin composition is 12%, and the viscosity of the prepolymerized resin composition sampled and tested is 276 mPa·s.

[0077] Example 7

[0078] The difference between Example 7 and Example 1 is that the reaction is carried out at the same temperature for 50 minutes, so that the reaction degree of the prepolymerized resin composition is 30%, and the viscosity of the prepolymerized resin composition sampled and tested is 423 mPa·s.

[0079] Example 8

[0080] The difference between Example 8 and Example 1 is that polybutadiene with a vinyl molar content of 30% (Shanghai Yaguo 15165) is used, the viscosity of the prepolymerized resin composition is 281 mPa·s, and the infrared spectrum of the sample before and after prepolymerization is tested, and the reaction degree is calculated to be 13%.

[0081] Example 9

[0082] The difference between Example 9 and Example 1 is that polybutadiene with a vinyl molar content of 70% (Shanghai Baisi LBR352) is used, the viscosity of the prepolymerized resin composition is 352 mPa·s, and the infrared spectrum of the sample before and after prepolymerization is tested, and the reaction degree is calculated to be 18%.

[0083] Example 10

[0084] The difference between Example 10 and Example 1 is that the water bath heating temperature is 35° C., the viscosity of the prepolymerized resin composition tested by sampling is 237 mPa·s, and the infrared spectrum of the sample before and after prepolymerization is tested, and the reaction degree is calculated to be 8%.

[0085] Embodiment 11

[0086] The difference between Example 11 and Example 1 is that the water bath heating temperature is 75° C., the viscosity of the prepolymerized resin composition tested by sampling is 466 mPa·s, and the infrared spectrum of the sample before and after prepolymerization is tested, and the reaction degree is calculated to be 32%.

[0087] Comparative Example 1

[0088] The difference between Comparative Example 1 and Example 1 is that no auxiliary cross-linking agent is added, and the viscosity of the prepolymerized resin composition is 256 mPa·s. The infrared spectrum of the sample before and after prepolymerization is tested, and the reaction degree is calculated to be 10%.

[0089] Comparative Example 2

[0090] The difference between Comparative Example 2 and Example 1 is that no low-temperature initiator is added, and the viscosity of the prepolymerized resin composition is 192 mPa·s. The infrared spectrum of the sample before and after prepolymerization is tested, and the reaction degree is calculated to be 4%.

[0091] Comparative Example 3

[0092] The difference between Comparative Example 3 and Example 1 is that no high temperature initiator is added.

[0093] Comparative Example 4

[0094] The difference between Comparative Example 4 and Example 3 is that the vinyl molar content of the cross-linking agent TAIC is 1% (molecular weight 249, Fang Ruida 245-10), the viscosity of the sampled prepolymerized resin composition is 265mPa·s, and the infrared spectrum of the sample before and after prepolymerization is tested, and the reaction degree is calculated to be 11%.

[0095] Comparative Example 5

[0096] The difference between Comparative Example 5 and Example 3 is that the vinyl molar content of the cross-linking agent TAIC is 7% (molecular weight 350, Huaxing 526), ​​the viscosity of the prepolymerized resin composition tested by sampling is 311 mPa·s, and the infrared spectrum of the sample before and after prepolymerization is tested, and the reaction degree is calculated to be 15%.

[0097] Comparative Example 6

[0098] The difference between Comparative Example 6 and Example 3 is that the molecular weight of the cross-linking agent TAIC is 100 (vinyl molar content is 2%, visbon PL301), the viscosity of the prepolymerized resin composition tested by sampling is 269 mPa·s, and the infrared spectrum of the sample before and after prepolymerization is tested, and the reaction degree is calculated to be 11%.

[0099] Comparative Example 7

[0100] The difference between Comparative Example 7 and Example 3 is that the molecular weight of the cross-linking agent TAIC is 600 (vinyl molar content is 5%, Wuhan Chengtian CT11066), the viscosity of the prepolymerized resin composition tested by sampling is 266 mPa·s, and the infrared spectrum of the samples before and after prepolymerization is tested, and the reaction degree is calculated to be 10%.

[0101] Comparative Example 8

[0102] The difference between Comparative Example 8 and Example 3 is that the optimal active temperature of the low-temperature initiator BPO is 30°C (molecular weight 242, strong BW75), the viscosity of the prepolymerized resin composition tested by sampling is 292mPa·s, and the infrared spectrum of the samples before and after prepolymerization is tested, and the reaction degree is calculated to be 14%.

[0103] Comparative Example 9

[0104] The difference between Comparative Example 9 and Example 3 is that the optimal activity temperature of the low-temperature initiator BPO is 120°C (molecular weight 242, strong BPO-50H), the viscosity of the prepolymerized resin composition tested by sampling is 244mPa·s, and the infrared spectrum of the samples before and after prepolymerization is tested, and the reaction degree is calculated to be 8%.

[0105] Comparative Example 10

[0106] The difference between Comparative Example 10 and Example 3 is that the molecular weight of the low-temperature initiator BPO is 100 (optimum activity temperature 86°C, Yunze BPO50-01), the viscosity of the prepolymerized resin composition tested by sampling is 282 mPa·s, and the infrared spectrum of the samples before and after prepolymerization is tested, and the reaction degree is calculated to be 13%.

[0107] Comparative Example 11

[0108] The difference between Comparative Example 11 and Example 3 is that the molecular weight of the low-temperature initiator BPO is 600 (optimum activity temperature 70°C, Yunze BPO50-03), the viscosity of the prepolymerized resin composition tested by sampling is 261 mPa·s, and the infrared spectrum of the samples before and after prepolymerization is tested, and the reaction degree is calculated to be 11%.

[0109] Comparative Example 12

[0110] The difference between Comparative Example 12 and Example 3 is that the optimal active temperature of the high temperature initiator DTBP is 120° C. (molecular weight 147, Weiqi W-14B).

[0111] Comparative Example 13

[0112] The difference between Comparative Example 13 and Example 3 is that the optimal active temperature of the high-temperature initiator DTBP is 300° C. (molecular weight 147, Aksu TXB).

[0113] Comparative Example 14

[0114] The difference between Comparative Example 14 and Example 3 is that the molecular weight of the high temperature initiator DTBP is 100 (optimum activity temperature 180° C., strong DTBP-99).

[0115] Comparative Example 15

[0116] The difference between Comparative Example 15 and Example 3 is that the molecular weight of the high-temperature initiator DTBP is 600 (optimum active temperature 150° C., Anhydrous C16).

[0117] Application Examples

[0118] The resin glue prepared in Example 1-11 was coated on a glass fiber cloth (1080 electronic fiber cloth) using a glass cloth stretching machine and a vertical oven and baked at 85°C to obtain a prepreg. The prepregs were then stacked and copper foils were combined on top and bottom, and hot pressed at 200°C to obtain a copper clad laminate, thereby obtaining Sample 1-11.

[0119] The resin composition layer on the surface of the semi-cured sheet obtained in Example 1 was subjected to DSC test, and the exothermic peak was around 190°C, and the thermal enthalpy was 9.09 J / g (180-220°C), indicating that the low-temperature initiator had fully exerted its initiating effect after prepolymerization and drying, and there was no residue. The resin composition layer on the surface of the semi-cured sheet obtained in Example 2 was subjected to DSC test, and the exothermic peaks were at 74°C and 190°C, indicating that the semi-cured sheet obtained without prepolymerization and only by drying had residual low-temperature initiator, which did not fully play an initiating role. The resin composition layer on the surface of the semi-cured sheet obtained in Examples 3-11 was subjected to DSC test, and there was no exothermic peak at 60°C-100°C, and the thermal enthalpy was less than 20 J / g (180-220°C).

[0120] Application comparison

[0121] The resin adhesives of comparative examples 1-15 were prepared into copper clad laminate samples 12-26 using the same preparation method as in the application example.

[0122] Samples 1-26 were tested for performance, wherein the test method for peel strength was in accordance with GB / T 4722-20177.2.1, and the width of the peel strip was 1 mm; the specific conditions for aging treatment were: 270°C for 2 days + 300°C for 1 day, and the peel strength attenuation rate after aging = (peel strength before aging - peel strength after aging) / peel strength before aging; dielectric constant (Dk): stripline method, in accordance with GB / T 12636-1990, sampling method: a total of 5 groups of diagonal sampling samples, and the dielectric performance uniformity of the samples was evaluated by calculating the extreme difference of Dk of the 5 groups of sampling samples. The test data are shown in Table 1.

[0123] Table 1

[0124]

[0125] According to Table 1, the circuit substrates prepared in Examples 1-11 can meet the high performance requirements of peel strength attenuation rate after aging and dielectric property uniformity. Among them, Example 5 adds slightly more initiator, which has the risk of initiator residue. Therefore, compared with Example 1, the peel strength attenuation rate of the prepared sample after aging is slightly higher, and the range is slightly increased.

[0126] The reaction degree of the prepolymer resin composition in Example 6 is slightly lower than 15%, and the reaction degree of the prepolymer resin composition in Example 7 is slightly higher than 25%. Compared with Example 1, the peel strength attenuation rate of the obtained sample after aging is slightly increased, and the range is slightly increased.

[0127] In Example 8, the vinyl content of the polybutadiene is slightly lower than 40%. Compared with Example 1, the peel strength attenuation rate of the obtained sample after aging is slightly increased, and the range is slightly increased. In Example 9, since the vinyl content of the polybutadiene is slightly higher than 60%, compared with Example 1, the peel strength attenuation rate of the obtained sample after aging is slightly increased, and the range is slightly increased.

[0128] The reaction temperature of Example 10 is 35° C., and the reaction temperature of Example 11 is slightly higher than 75° C. Compared with Example 1, the peel strength attenuation rate of the obtained sample after aging is slightly increased, and the range is slightly increased.

[0129] In Comparative Example 1, since no auxiliary cross-linking agent is added, the double bonds surrounded by long side chains in the unsaturated double bond resin are difficult to participate in the reaction, which not only causes more double bonds to remain in the unsaturated double bond resin and reduces the cross-linking density, thereby making the peel strength of the circuit substrate poor, but also increases the oxidation risk, resulting in a higher peel strength attenuation rate of the circuit substrate after aging, and poor uniformity of dielectric properties.

[0130] In Comparative Example 2, since no low-temperature initiator was added, the unsaturated double-bond resin was cross-linked only by the lamination process, and the cross-linking density was limited, resulting in the defect of insufficient peel strength of the circuit substrate. At the same time, the peel strength attenuation rate of the circuit substrate after aging was high, and the uniformity of dielectric properties was poor. In Comparative Example 3, since no high-temperature initiator was added, the low-temperature initiator decomposed at high temperature during the lamination process and could not achieve the initiation effect, the cross-linking density was low, the peel strength attenuation rate of the circuit substrate after aging was high, and the uniformity of dielectric properties was poor.

[0131] In Comparative Example 4, since the vinyl content of the co-crosslinking agent is too low, the crosslinking efficiency is low, the improvement of the crosslinking density is limited, and the effect of the co-crosslinking agent cannot be achieved; in Comparative Example 5, since the vinyl content of the co-crosslinking agent is too high, the amount of double bonds that do not participate in the reaction in the co-crosslinking agent will also increase accordingly, becoming a failure point, affecting the bonding strength between the copper foil and the resin composition layer after aging, and at the same time, the probability of reaction between the co-crosslinking agents is increased, and internal consumption is caused, and the crosslinking effect cannot be fully achieved.

[0132] In Comparative Example 6, since the molecular weight of the cross-linking agent is too low, the boiling point is generally low, and it is easy to volatilize during the baking process, making it difficult to play a cross-linking role; in Comparative Example 7, since the molecular weight of the cross-linking agent is too high, the volume or degree of branching of the molecule increases, the difficulty of the reaction increases, resulting in an increase in the residual double bonds, which increases the peel strength attenuation rate of the circuit substrate after aging, and the uniformity of the dielectric properties deteriorates.

[0133] In Comparative Example 8, since the optimum active temperature of the low-temperature initiator is less than 60°C, the low-temperature initiator self-decomposes too quickly, and the double bond reaction cannot be fully initiated during the formation of the prepolymer resin composition; in Comparative Example 9, since the optimum active temperature of the low-temperature initiator is greater than 90°C, its own stability is relatively high, the number and concentration of free radicals generated are low, and the initiation effect is insufficient. Therefore, the dielectric properties of the obtained circuit substrate are not uniform, and the peel strength attenuation rate increases after aging.

[0134] In Comparative Example 10, since the molecular weight of the low-temperature initiator is too low, the initiator volatilizes during the baking process, which reduces the actual initiator content and weakens the initiation effect. In addition, gas is generated during the volatilization process, resulting in a poor appearance of the resin composition layer, thereby making the appearance of the circuit substrate after lamination poor. In Comparative Example 11, since the molecular weight of the low-temperature initiator is too high, the compatibility in the resin system is poor, and the degree of reaction of each part is different during the formation of the resin composition layer, resulting in differences in the performance of different parts of the circuit substrate after lamination, poor uniformity of dielectric properties, and a high peel strength attenuation rate after aging of the circuit substrate.

[0135] In Comparative Example 12, since the optimal active temperature of the high-temperature initiator is less than 140°C, the high-temperature initiator self-decomposes too quickly and cannot fully initiate the double bond reaction during the pressing process, resulting in a large number of residual double bonds and a low cross-linking density. In Comparative Example 13, since the optimal active temperature of the high-temperature initiator is greater than 220°C, its own stability is relatively high, the number and concentration of free radicals generated are low, and it cannot play an initiating role, and the cross-linking density is low, resulting in a large peeling attenuation rate of the circuit substrate after aging and poor uniformity of dielectric properties.

[0136] In Comparative Example 14, since the molecular weight of the high-temperature initiator is too low, the initiator volatilizes during the pressing process, which reduces the actual initiator content and weakens the initiation effect. In addition, gas is generated during the volatilization process, causing bubbles in the circuit substrate and affecting the appearance. In Comparative Example 15, since the molecular weight of the high-temperature initiator is too high, its compatibility in the resin system is poor, and the reaction degrees of various parts are different, resulting in poor uniformity of dielectric properties due to differences in performance of different parts of the high-temperature initiator after pressing.

[0137] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described 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-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A resin glue, characterized in that: The invention comprises an unsaturated double bond resin, a co-crosslinking agent, a low temperature initiator, a high temperature initiator and a solvent, or comprises a prepolymer resin composition and a high temperature initiator, wherein the prepolymer resin composition is obtained by incompletely reacting an unsaturated double bond resin, a low temperature initiator and a co-crosslinking agent in a solvent; The vinyl molar content of the auxiliary crosslinking agent is 2%-5%, and the molecular weight is 180-380. The optimal active temperature of the low-temperature initiator is 60°C-90°C, and the molecular weight is 120-400. The optimal active temperature of the high-temperature initiator is 140°C-220°C, and the molecular weight is 140-400.

2. The resin glue according to claim 1, characterized in that: The reaction degree of the prepolymerized resin composition is 15%-25%; And / or, the viscosity of the prepolymer resin composition is 300 mPa·s-400 mPa·s.

3. The resin glue according to any one of claims 1-2, characterized in that: Based on 100 parts by weight of the unsaturated double bond resin, the auxiliary cross-linking agent is 2 parts by weight to 6 parts by weight, the low-temperature initiator is 1 part by weight to 5 parts by weight, and the high-temperature initiator is 1 part by weight to 5 parts by weight.

4. The resin glue according to any one of claims 1-2, characterized in that: The molar content of vinyl in the unsaturated double bond resin is 40%-60%; And / or, the unsaturated double bond resin is selected from at least one of hydrocarbon resin, unsaturated polyester and unsaturated polyether.

5. The resin glue according to any one of claims 1-2, characterized in that: The low-temperature initiator is selected from at least one of dibenzoyl peroxide, bis(4-tert-butylcyclohexyl) peroxydicarbonate, and azobisisobutyronitrile.

6. The resin glue according to any one of claims 1-2, characterized in that: The high temperature initiator is selected from at least one of di-tert-butyl peroxide isopropylbenzene, di-tert-butyl peroxide, di-tert-butyl peroxide, diisopropylbenzene peroxide and isopropylbenzene hydroperoxide.

7. A method for preparing the resin adhesive according to any one of claims 1 to 6, characterized in that: include: Mixing an unsaturated double-bond resin, a cross-linking aid, a low-temperature initiator, a high-temperature initiator and a solvent to obtain a resin glue solution; Alternatively, the unsaturated double bond resin, the low temperature initiator and the auxiliary cross-linking agent are reacted incompletely in a solvent to obtain a prepolymer resin composition, and then the prepolymer resin composition is mixed with a high temperature initiator to obtain a resin glue solution.

8. The method for preparing the resin adhesive according to claim 7, characterized in that: The incomplete reaction is carried out under an inert gas atmosphere and / or at 40° C.-70° C.

9. A prepreg, characterized in that: The prepreg comprises a reinforcing material and a resin composition layer attached to the reinforcing material, wherein the resin composition layer is obtained by drying the resin glue according to any one of claims 1 to 6.

10. A circuit substrate made of the prepreg according to claim 9.

11. A printed circuit board made of the circuit substrate according to claim 10.

Images