A resin composition and a resin cured product

Abstract

The application discloses a resin composition and a resin cured product, and relates to the technical field of insulating materials. The resin composition comprises an epoxy resin, a curing agent, an inorganic filler and an adhesion aid. The adhesion aid comprises a cyclic polyimide resin and a polycarbodiimide. The resin composition in the application has high adhesion, low dielectric loss and low CET, and the surface of the insulating layer after removing the residue has low roughness.

Description

Technical Field

[0001] This application relates to the field of insulating materials technology, and more particularly to a resin composition and a cured resin product. Background Technology

[0002] In advanced electronic packaging, particularly in high-density interconnect (HDI) substrates, chip-scale packages (CSPs), and system-in-package (SiPs), the performance of resin compositions (typically used as prepregs or laminated films) serving as insulating layers and interlayer dielectrics is crucial. As electronic devices evolve towards higher frequencies, higher speeds, miniaturization, higher reliability, and higher power density, resin compositions, in addition to requiring low dielectric loss (Df) and low coefficient of thermal expansion (CTE), must also possess excellent peel strength with conductor layers such as copper foil. This ensures strong adhesion of circuit wires during subsequent processing and use, preventing conductor layer peeling failure.

[0003] Furthermore, during product manufacturing, especially after laser drilling or mechanical drilling to form micropores, a desmearing process (usually using strong oxidizing solutions such as potassium permanganate) is necessary to remove residual resin composition from the hole walls and activate the surface of the insulating layer (or interlayer dielectric), ensuring reliable metallization bonding for subsequent electroless copper plating or direct electroplating. However, this process erodes the surface of the insulating layer (or interlayer dielectric), leading to increased micro-roughness. Excessive roughness can not only affect the uniformity and adhesion of the metallization layer, but more importantly, it can significantly exacerbate conductor losses caused by the skin effect at high frequencies. Therefore, the ideal insulating resin composition for packaging substrates needs to simultaneously meet four key performance indicators: low CTE, low Df, high conductor layer adhesion, and low surface roughness after desmearing. This presents a significant technical challenge in its implementation.

[0004] The most common approach to improving conductor layer adhesion is to add small-molecule polar adhesion promoters to the resin composition. However, these small-molecule adhesion promoters typically have high polarity or hydrophilicity, and their molecular orientation relaxation at high frequencies leads to a significant increase in dielectric loss (Df), which is extremely detrimental to applications seeking low signal loss. Furthermore, these small-molecule additives and oligomers with polar groups are at risk of being largely washed away during the desizing process, resulting in high surface roughness. It is difficult to achieve high adhesion while maintaining extremely low Df and ensuring low surface roughness of the resin after desizing, which is the main bottleneck facing current technologies. Summary of the Invention

[0005] In view of the above, this application provides a resin composition and a cured resin product, which aims to solve at least one of the above technical problems.

[0006] The first aspect of this application provides a resin composition comprising an epoxy resin, a curing agent, a filler, and an adhesive aid; wherein the adhesive aid comprises a cyclic polyimide resin and polycarbodiimide.

[0007] In some embodiments, the adhesive aid comprises, by weight, 0.2% to 20% of the non-volatile components in the resin composition other than the filler.

[0008] In some embodiments, the mass ratio of the cyclic polyimide resin to the polycarbodiimide is 1:(1 to 6).

[0009] In some embodiments, the ratio of the cyclic polyimide resin to the total amount of non-volatile components in the resin composition, excluding the filler, is less than 6%.

[0010] In some embodiments, the ratio of the cyclic polyimide resin to the total amount of non-volatile components in the resin composition, excluding the filler, is greater than 0.9% and less than 4%.

[0011] In some embodiments, the epoxy resin includes biphenyl-type epoxy resin, bisphenol A-type epoxy resin, and naphthalene-type epoxy resin.

[0012] In some embodiments, the curing agent further includes at least one of an active ester curing agent, a phenolic curing agent, and a carbodiimide curing agent.

[0013] In some embodiments, the epoxy resin accounts for 5.5% to 7.5% of the non-volatile components in the resin composition, by weight. And / or, the curing agent accounts for 15% to 19% of the non-volatile components in the resin composition; And / or, the filler constitutes 70% to 80% of the non-volatile components in the resin composition; And / or, the resin composition further includes a curing accelerator, the curing accelerator comprising 0.1% to 1% of the non-volatile components in the resin composition; And / or, the resin composition further includes a toughening agent, the toughening agent comprising 0.4% to 0.8% of the non-volatile components in the resin composition.

[0014] A second aspect of this application provides a resin cured product, which is formed by curing the resin composition.

[0015] Beneficial effects: In this embodiment, by adding cyclic polyimide resin and polycarbodiimide to the resin composition, the elongation at break and adhesive strength of the resin composition are improved, while the dielectric properties and CET are not significantly improved. This makes the resin composition of this application simultaneously have high elongation at break and adhesive strength, and low roughness, dielectric properties and CET. Detailed Implementation

[0016] The experimental examples described in this application are merely some embodiments of this application, not all embodiments. All other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this application. Furthermore, it should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit this application.

[0017] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0018] In the description of this application, the term "comprising" means "including but not limited to". The terms first, second, third, etc. are used merely as illustrative purposes and do not impose numerical requirements or establish an order.

[0019] In this application, "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural.

[0020] In this application, "at least one" means one or more, and "more than one" means two or more. "One or more", "at least one of the following", or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0021] Various embodiments of this application may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a hard limitation on the scope of this application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Furthermore, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the referred range.

[0022] In advanced electronic packaging, particularly in high-density interconnect (HDI) substrates, chip-scale packages (CSPs), and system-in-package (SiPs), the performance of resin compositions (typically used as prepregs or laminated films) serving as insulating layers and interlayer dielectrics is crucial. As electronic devices evolve towards higher frequencies, higher speeds, miniaturization, higher reliability, and higher power density, resin compositions, in addition to requiring low dielectric loss (Df) and low coefficient of thermal expansion (CTE), must also possess excellent peel strength with conductor layers such as copper foil. This ensures strong adhesion of circuit wires during subsequent processing and use, preventing conductor layer peeling failure.

[0023] In addition, during the product manufacturing process, especially after laser drilling or mechanical drilling to form micropores, a desmearing process (usually using strong oxidizing solutions such as potassium permanganate) must be carried out to remove the resin composition residue on the hole wall and activate the surface of the insulating layer (or interlayer dielectric layer), which leads to an increase in its micro-roughness. Excessive roughness may not only affect the uniformity and adhesion of the metallization layer, but more importantly, it will significantly aggravate the conductor loss caused by the skin effect at high frequencies.

[0024] The most common approach to improving conductor layer adhesion is to add small-molecule adhesion promoters to the resin composition. These additives are typically low-molecular-weight compounds containing specific functional groups (such as thiol groups, carboxyl groups, hydroxyl groups, amino groups, silane groups, etc.). Other types of adhesion promoters include organosilane coupling agents and certain oligomers containing polar groups. However, these small-molecule adhesion promoters often have high polarity or hydrophilicity, and their molecular orientation relaxation at high frequencies can lead to a significant increase in dielectric loss (Df), which is extremely detrimental to applications seeking low signal loss. Furthermore, these small-molecule additives and oligomers with polar groups pose a risk of significant surface roughness due to excessive leaching during the deslagging process.

[0025] To reduce dielectric loss, existing technologies generally introduce fluorinated epoxy resins. However, perfluorinated and polyfluoroalkyl substances (PFAS) have extremely strong environmental persistence and can accumulate in the human body through bioaccumulation effects, significantly increasing health risks such as cancer and immune system disorders. Europe and the United States have successively implemented comprehensive bans and restrictive regulations.

[0026] Therefore, it is necessary to provide an environmentally friendly resin composition, wherein the insulating layer formed after curing has high adhesion, low dielectric loss, low CET, and low surface roughness of the insulating layer after deslagging.

[0027] Specifically, this application provides a resin composition comprising an epoxy resin, an active ester curing agent, an inorganic filler, and an adhesive additive; wherein the adhesive additive comprises a cyclic polyimide resin and polycarbodiimide. The material formed after curing the resin composition provided in this application simultaneously exhibits high adhesive strength, low dielectric loss, low CET, and low surface roughness after removing adhesive residue.

[0028] It should be noted that the inventors discovered through research that a resin system consisting of epoxy resin, reactive ester curing agent, and inorganic filler (such as silica) can achieve low dielectric loss and low CTE, but it suffers from low elongation at break and is prone to cracking. Through continuous experimentation with different adhesive additives, the inventors found that adding cyclic polyimide and polycarbodiimide to the resin composition can synergistically improve the adhesion between the cured material and the conductor layer (such as a copper layer) and significantly increase the elongation at break without increasing the CTE and Df of the material. Therefore, the insulating layer formed after curing the resin composition in this application simultaneously possesses high toughness and adhesion, low dielectric loss, low CET, and low surface roughness after removing adhesive residue. Cyclic polyimide refers to polyimide whose polymer backbone contains repeating cyclic imide structural units.

[0029] It is worth mentioning that, regarding the issues of low adhesion and elongation at break, and easy cracking, in resin systems composed of epoxy resin, reactive ester curing agents, and inorganic fillers, the inventors also attempted to add small-molecule polar adhesion promoters. While these promoters could improve the adhesion strength between the cured resin composition and the conductor layer, their strong polarity led to a significant increase in the dielectric loss (Df) of the resin composition, making it difficult to meet the low-loss requirements of high-frequency applications. In other words, while improving adhesion, the original low dielectric loss performance was sacrificed. Furthermore, these small molecules pose a migration risk, which may affect long-term reliability. The inventors also tried adding cyclic polyimide, but this resulted in an increase in the coefficient of thermal expansion (CTE) of the material. However, the simultaneous addition of cyclic polyimide and polycarbodiimide to the resin composition could improve the adhesion strength and elongation at break between the material and the conductor layer without significantly increasing the CTE and Df, demonstrating surprisingly good results.

[0030] For example, the cyclic polyimide may be one of "RIKACOATSN20" or "RIKACOAT PN20" manufactured by Shin-Etsu Chemical Co., Ltd., "SLK-6100" manufactured by Shin-Etsu Chemical Co., Ltd., or "PIAD-100H", "PIAD-150L", "PIAD-152H" or "PIAD-300" manufactured by Arakawa Chemical Co., Ltd.

[0031] Of course, in other embodiments of this application, cyclic polyimide can also be prepared from dianhydride and diamine, and this is not limited here.

[0032] For example, dianhydrides include aromatic dianhydrides. Aromatic dianhydrides include at least one of pyromellitic dianhydride, 4,4'-biphenyl ether dianhydride, 3,4,3',4'-triphenyl diether dianhydride, 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]malonic dianhydride, and 2,2-diphenylpropane-3,4,3',4'-tetracarboxylic dianhydride. Of course, dianhydrides also include alicyclic and aliphatic dianhydrides. Among them, alicyclic dianhydrides can be 1,2,3,4-cyclobutanetetracarboxylic dianhydride, bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, etc. Aliphatic dianhydrides can be butanetetracarboxylic dianhydride, 1,2,3,4-butanetetracarboxylic dianhydride, pentane-1,2,3,4-tetracarboxylic dianhydride, etc.

[0033] For example, diamines include at least one of dimer diamines, alicyclic diamines, and diaminodiamines. It should be noted that dimer diamines refer to substances formed by replacing all carboxyl groups of a dimer acid with primary amino or primary aminomethyl groups. Dimeric acids mainly include 36-carbon diprotic acids (dicarboxylic acids) obtained by dimerizing unsaturated fatty acids such as oleic acid, linoleic acid, and linolenic acid. Depending on their degree of purification, they include monomeric acids with 18 carbon atoms, trimeric acids with 54 carbon atoms, and polymeric fatty acids with 20-90 carbon atoms. Furthermore, while the aforementioned dimeric acids contain double bonds, the degree of unsaturation can be reduced through hydrogenation reactions; they can also be understood as unsaturated fatty acids containing different numbers of double bonds.

[0034] For example, alicyclic diamines include, but are not limited to, diaminocyclohexane, diaminodicyclohexylmethane, dimethyldiaminodicyclohexylmethane, diaminobicyclo[2.2.1]heptane, bis(aminomethyl)-bicyclo[2.2.1]heptane, 3(4),8(9)-bis(aminomethyl)tricyclo[5.2.1.02,6]decane, isophorone diamine, 4,4'-diaminodicyclohexylmethane, and 1,3-diaminomethylcyclohexane.

[0035] For example, diaminodiamine includes, but is not limited to, diaminophenoxyphenylpropane, diaminodiphenyl ether, diaminodiphenyl sulfide, diaminodiphenyl sulfone, diaminobenzophenone, diaminodiphenylmethane, diaminophenylpropane, diaminophenylhexafluoropropane, diaminophenoxybenzene, diaminobenzoylbenzene, diaminodimethylbenzene, diaminodifluoromethylbenzene, etc.

[0036] In some embodiments of this application, the adhesive aid is composed of cyclic polyimide resin and polycarbodiimide; wherein the mass ratio of cyclic polyimide resin to polycarbodiimide is 1:(1 to 6). Exemplarily, the mass ratio of cyclic polyimide resin to polycarbodiimide is 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, and any range between the above two values. This is advantageous because it allows the resin composition in this application to simultaneously possess high adhesive strength and elongation at break, without causing material CTE, roughness after degumming, and D. f Significantly increased.

[0037] In some embodiments, the adhesive aid comprises 0.2% to 20% of the total mass of non-volatile components (excluding fillers) in the resin composition, and the adhesive aid is composed of cyclic polyimide resin and polycarbodiimide. Both cyclic polyimide resin and polycarbodiimide are added to the resin composition simultaneously, and the ratio of the cyclic polyimide resin to the total mass of non-volatile components (excluding fillers) in the resin composition is less than 6%. This is beneficial for the resin composition to have a low CTE, and for the resin composition to simultaneously possess high adhesive strength, elongation at break, and low roughness after degreasing, and for the cured material to have low CTE and low D. f The basics remain unchanged.

[0038] It should be noted that, since the non-volatile components in a resin composition, besides fillers, mainly consist of the resin matrix and curing agent, for ease of understanding, the total mass of the non-volatile components excluding fillers in the resin composition can be approximated as the total mass of the resin matrix (e.g., epoxy resin) and curing agent in the resin composition. Therefore, the fact that adhesive additives account for 0.2% to 20% of the total mass of non-volatile components excluding fillers in the resin composition can also be understood as the fact that adhesive additives account for 0.2% to 20% of the total mass of the resin matrix and curing agent in the resin composition. Similarly, the ratio of cyclic polyimide resin to the total mass of non-volatile resin components excluding fillers in the resin composition being less than 4% can also be understood as the ratio of cyclic polyimide resin to the total mass of the resin matrix and curing agent in the resin composition being less than 4%.

[0039] Furthermore, in the resin composition, the adhesive additive accounts for 0.2% to 20% of the total non-volatile components of the resin composition excluding fillers. The adhesive additive is composed of cyclic polyimide resin and polycarbodiimide, and the ratio of the cyclic polyimide resin to the total non-volatile components of the resin composition excluding fillers is higher than 0.9% and lower than 4%. This improves the adhesive strength and elongation at break of the cured material, reduces the roughness after removing adhesive residue, and increases the material's CTE and D. f The basics remain unchanged.

[0040] It should be noted that polycarbodiimide is a dimer, oligomer, or polymer containing carbodiimide groups (—N=C=N—). It can be polymerized from one organic diisocyanate or formed by random copolymerization, alternating copolymerization, or block copolymerization of two or more different organic diisocyanate monomers, wherein the number of carbodiimide groups (—N=C=N—) is greater than or equal to 2.

[0041] Specifically, polycarbodiimides include, but are not limited to, aliphatic polycarbodiimides such as polyhexamethylene carbodiimide, polytrimethylhexamethylene carbodiimide, polycyclohexylene carbodiimide, poly(methylene bis(cyclohexylene carbodiimide), poly(isophorone carbodiimide); poly(phenylene carbodiimide), poly(naphthylene carbodiimide), poly(tolylene carbodiimide), poly(methyl diisopropylphenylene carbodiimide), poly(triethylphenylene carbodiimide), poly(diethylphenylene carbodiimide), poly(triisopropylphenylene carbodiimide), poly(diisopropylphenylene carbodiimide), poly(xylene carbodiimide), poly(tetramethylxylene carbodiimide), poly(methylene diphenylene carbodiimide), and poly[methylene bis(methylphenylene)carbodiimide].

[0042] In some embodiments of this application, the polycarbodiimide includes at least one of poly(diisopropylphenylcarbodiimide) and poly(isophoronecarbodiimide).

[0043] Commercially available polycarbodiimide products include: "CARBODILITE V-02B", "CARBODILITE V-03", "CARBODILITE V-04K", "CARBODILITE V-07" and "CARBODILITE V-09" manufactured by Nisshinbo Chemical Co., Ltd.; "UN-03", "UN-25", "UN-25S", "UN-350", "UN-160" and "UN-159" manufactured by Shanghai Youen Chemical Co., Ltd.; "HyMax® 213" and "HyMax® 220" manufactured by Langyi New Materials Co., Ltd.; and "Stabaxol P", "Stabaxol P400" and "Hycasyl 510" manufactured by Rhein Chemie Co., Ltd.

[0044] In some embodiments of this application, the total mass ratio of the adhesive additive to the non-volatile components (excluding fillers) in the resin composition, by mass parts, is 0.2% to 20%. Exemplarily, the mass ratio of the adhesive additive to the non-volatile portion of the resin composition is 0.2%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, 10%, 10.5%, 11%, 11.5%, 12%, 12.5%, 13%, 13.5%, 14%, 14.5%, 15%, 15.5%, 16%, 16.5%, 17%, 17.5%, 18%, 18.5%, 19%, 19.5%, 20%, and any range between any two of the above values. In this embodiment, by ensuring the amount of adhesive additive meets the above ratio, the adhesion strength and heat resistance to copper foil can be significantly improved while maintaining a low coefficient of thermal expansion with almost no noticeable change. Furthermore, the total mass ratio of the adhesive additive to the non-volatile components in the resin composition, excluding fillers, is 1% to 20%.

[0045] In some embodiments of this application, the resin matrix in the resin composition is epoxy resin, and the epoxy resin accounts for 5.5% to 7.5% of the non-volatile components in the resin composition. Exemplarily, the epoxy resin accounts for 5.5%, 6%, 7%, 7.5% of the non-volatile components in the resin composition, and values ​​between any two of the above values.

[0046] In some examples of this application, the epoxy resin can be an existing solid and / or liquid epoxy resin. Specific examples include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD ​​type epoxy resin, biphenyl type epoxy resin, naphthalene type epoxy resin, aminophenol type epoxy resin, and polyalkyl glycol type epoxy resin. The epoxy resins listed above can be used alone or in combination, and this is not limited thereto.

[0047] In some examples of this application, epoxy resins include bisphenol A type epoxy resins, biphenyl type epoxy resins, and naphthalene type epoxy resins.

[0048] Specifically, to further improve the dielectric and mechanical properties of the resin composition, the epoxy resin includes biphenyl-type epoxy resin (e.g., epoxy equivalent of approximately 290 g / eq), bisphenol A-type epoxy resin (e.g., epoxy equivalent of approximately 188 g / eq), and naphthalene-type epoxy resin (e.g., epoxy equivalent of approximately 144 g / eq). It should be noted that the specific epoxy equivalent of the biphenyl-type epoxy resin, the bisphenol A-type epoxy resin, and the naphthalene-type epoxy resin can be selected based on actual application conditions. These are mainly used to calculate the amount of curing agent to be added and are not limited here.

[0049] For example, the epoxy resin is composed of biphenyl-type epoxy resin (epoxy equivalent approximately 290 g / eq), bisphenol A-type epoxy resin (epoxy equivalent approximately 188 g / eq), and naphthalene-type epoxy resin (epoxy equivalent approximately 144 g / eq), with a mass ratio of biphenyl-type epoxy resin: bisphenol A-type epoxy resin: naphthalene-type epoxy resin of 5:5:4. This is beneficial for improving the dielectric and mechanical properties of the cured resin.

[0050] In some examples of this application, the curing agent accounts for 15% to 19% of the non-volatile components in the resin composition. Exemplarily, the curing agent accounts for 15%, 15.5%, 16%, 16.5%, 17%, 17.5%, 18%, 18.5%, 19% of the non-volatile components in the resin composition, as well as values ​​between any two of the above.

[0051] In some examples of this application, the curing agent includes an active ester curing agent. Suitable specific examples of active ester curing agents include active ester compounds containing a dicyclopentadiene-type diphenol structure, active ester compounds containing a naphthalene structure, active ester compounds containing acetylated derivatives of phenolic resins, and active ester compounds containing benzoyl derivatives of phenolic resins. From the viewpoint of providing good dielectric properties, active ester compounds containing a naphthalene structure and active ester compounds containing a dicyclopentadiene-type diphenol structure are more preferred. "Dicyclopentadiene-type diphenol structure" refers to a divalent structural unit formed from phenylene-dicyclopentylene-phenylene.

[0052] Commercially available reactive ester curing agents include, for example, reactive ester resins containing a dicyclopentadiene-type diphenol structure such as "EXB-9451", "EXB-9460", "EXB-9460S", "HPC-8000-65T", "HPC-8000H-65TM", and "HPC-8000L-65TM" (manufactured by DIC); and reactive ester resins containing a naphthalene structure such as "EXB-8100L-65T", "EXB-8150-60T", "EXB-8150-62T", "EXB-9416-70BK", "HPC-8150-60T", and "HPC-8150- Examples of active ester resins include “62T”, “HP-B-8151-62T”, and “HP-C-8151-62T” (manufactured by DIC Corporation); examples of phosphorus-containing active ester resins include “EXB9401” (manufactured by DIC Corporation); examples of active ester resins that are acetylated derivatives of phenolic resins include “DC808” (manufactured by Mitsubishi Chemical Corporation); examples of active ester resins that are benzoyl derivatives of phenolic resins include “YLH1026”, “YLH1030”, and “YLH1048” (manufactured by Mitsubishi Chemical Corporation); examples of active ester resins containing styrene and naphthalene structures include “PC1300-02-65MA” (manufactured by AIR&WATER Corporation), etc.

[0053] In some examples of this application, the curing agent further includes a phenolic curing agent. From the viewpoint of heat resistance and water resistance, a phenolic curing agent having a phenolic varnish structure is preferred. Furthermore, from the viewpoint of adhesion to the adhered material, a nitrogen-containing phenolic curing agent is preferred, and a phenolic curing agent containing a triazine skeleton is more preferred. From the viewpoint of highly satisfying heat resistance, water resistance, and adhesion, a phenolic varnish resin containing a triazine skeleton is preferred. Specific examples of phenolic and naphthol curing agents include: "MEH-7700", "MEH-7810", "MEH-7851", and "MEH-8000H" manufactured by Meiwa Kasei Corporation; "NHN", "CBN", and "GPH" manufactured by Nippon Kayaku Co., Ltd.; and "SN-170", "SN-180", "SN-190", "SN-475", "SN-485", "SN-495", "SN-495V", and "SN-37" manufactured by Nippon Steel Chemical Materials Co., Ltd. 5”, SN-395; DIC Company’s “TD-2090”, “TD-2090-60M”, “LA-7052”, “LA-7054”, “LA-1356”, “LA-3018”, “LA-3018-50P”, “EXB-9500”, “HPC-9500”, “KA-1160”, “KA-1163”, “KA-1165”; Qunrong Chemical Company’s “GDP-6115L”, “GDP-6115H”, “ELPC 75”, etc.

[0054] For example, the curing agent consists of an active ester curing agent (e.g., an active group equivalent of 238 g / eq) and a phenolic resin curing agent (e.g., an active group equivalent of 151 g / eq). The phenolic resin curing agent is a phenolic resin containing a triazine backbone, and the ratio of active ester curing agent to phenolic resin curing agent is 35:3 by mass. It should be noted that the specific equivalents of the active groups in the active ester curing agent and the phenolic resin curing agent are used to calculate the ratio of curing agent to epoxy equivalent. In this embodiment, the higher proportion of active ester curing agent is beneficial for improving the dielectric properties of the resin composition. Furthermore, the phenolic resin containing a triazine backbone is beneficial for improving the adhesive strength and resistance to damp heat aging of the resin composition.

[0055] In some examples of this application, the inorganic filler accounts for 70% to 80% of the non-volatile components in the resin composition. Exemplarily, the inorganic filler accounts for 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80% of the non-volatile components in the resin composition, as well as values ​​between any two of the above.

[0056] In some examples of this application, the inorganic filler may include at least one selected from silica, alumina, aluminum nitride, silicon carbide (SiC), boron nitride, zircon, calcium silicate, calcium carbonate, and barium titanate. Exemplarily, the inorganic filler is spherical silica. This is advantageous for reducing the viscosity of the epoxy resin composition in this application and lowering raw material costs.

[0057] Furthermore, the inorganic filler is an inorganic filler that has undergone surface modification with a silane coupling agent. This is beneficial for further improving the elongation at break of the cured resin.

[0058] In some examples of this application, the resin composition further includes a curing accelerator. Further, the curing accelerator accounts for 0.1% to 1% of the non-volatile components in the resin composition. Exemplarily, the curing accelerator accounts for 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9% of the non-volatile components in the resin composition, and values ​​within any two of the above ranges.

[0059] In some examples of this application, the curing accelerator includes at least one of imidazole accelerators, tertiary amine accelerators, modified amine accelerators, naphthenic acid metal salt accelerators, and substituted urea accelerators. Exemplarily, the curing accelerator is a benzylimidazolium curing accelerator.

[0060] In some examples of this application, the resin composition further includes a toughening agent. Further, the toughening agent comprises 0.4% to 0.8% of the non-volatile components in the resin composition. Exemplarily, the toughening agent comprises 0.4%, 0.5%, 0.6%, 0.7%, 0.8% of the non-volatile components in the resin composition, and values ​​within any two of the above ranges.

[0061] In some examples of this application, the toughening agent includes at least one of thermoplastic toughening agents, thermoplastic elastomer toughening agents, rubber toughening agents, silicone toughening agents, nanomaterial toughening agents, and core-shell structure toughening agents. Exemplarily, the toughening agent is an MBS-type toughening agent. MBS is a terpolymer composed of methyl methacrylate (MMA), butadiene (B), and styrene (S), and has a typical core-shell structure.

[0062] In some embodiments of this application, the non-volatile components in the resin composition, calculated by weight, include 8 to 20 parts epoxy resin, 25 to 45 parts curing agent, 145 to 180 parts inorganic filler, 0.5 to 20 parts adhesive aid, 0.1 to 1 part curing accelerator, and 0.5 to 1.5 parts toughening agent. Further, the non-volatile components in the resin composition include 13 to 15 parts epoxy resin, 37 to 39 parts curing agent, 150 to 180 parts inorganic filler, 1 to 10 parts adhesive aid, 0.4 to 0.6 parts curing accelerator, and 0.9 to 1.1 parts toughening agent. The epoxy resin is composed of biphenyl-type epoxy resin (epoxy equivalent approximately 290 g / eq), bisphenol A-type epoxy resin (epoxy equivalent approximately 188 g / eq), and naphthalene-type epoxy resin (epoxy equivalent approximately 144 g / eq), with a biphenyl-type epoxy resin:bisphenol A-type epoxy resin:naphthalene-type epoxy resin ratio of 4:5:5; the inorganic filler is spherical silica; the curing accelerator is composed of reactive ester curing agent (238 g / eq) and phenolic resin curing agent (151 g / eq), with a reactive ester curing agent:phenolic resin curing agent ratio of 35:3; the curing accelerator is benzylimidazolium-based; and the toughening agent is MBS-based.

[0063] In some embodiments of this application, the non-volatile components in the resin composition include epoxy resin, curing agent, inorganic filler, adhesive aid, curing accelerator, and toughening agent. By weight, epoxy resin accounts for 5.5% to 7.5% of the non-volatile components in the resin composition; curing agent accounts for 15% to 19% of the non-volatile components in the resin composition; inorganic filler accounts for 70% to 80% of the non-volatile components in the resin composition; adhesive aid accounts for 0.1% to 0.5% of the non-volatile components in the resin composition; curing accelerator accounts for 0.1% to 1% of the non-volatile components in the resin composition; and toughening agent accounts for 0.4% to 0.8% of the non-volatile components in the resin composition. Further, the epoxy resin accounts for 6% to 6.8% of the non-volatile components in the resin composition; the curing agent accounts for 16% to 18.5% of the non-volatile components in the resin composition; the inorganic filler accounts for 73% to 76% of the non-volatile components in the resin composition; the adhesive aid accounts for 0.6% of the non-volatile components in the resin composition; the curing accelerator accounts for 0.1% to 0.3% of the non-volatile components in the resin composition; and the toughening agent accounts for 0.3% to 0.6% of the non-volatile components in the resin composition. The epoxy resin is composed of biphenyl-type epoxy resin (epoxy equivalent approximately 290 g / eq), bisphenol A-type epoxy resin (epoxy equivalent approximately 188 g / eq), and naphthalene-type epoxy resin (epoxy equivalent approximately 144 g / eq), with a biphenyl-type epoxy resin:bisphenol A-type epoxy resin:naphthalene-type epoxy resin ratio of 4:5:5; the inorganic filler is spherical silica; the curing accelerator is composed of an active ester curing agent (238 g / eq) and a phenolic resin curing agent (151 g / eq), with an active ester curing agent:phenolic resin curing agent ratio of 35:3; the curing accelerator is benzylimidazolium; and the toughening agent is MBS. Thus, the insulating layer formed after curing of the resin composition in the embodiments of this application simultaneously possesses high adhesion, low dielectric loss, low CET, and low surface roughness after removing adhesive residue.

[0064] This application also provides a resin cured product, which is formed by curing the aforementioned resin composition.

[0065] Example 1 Five parts of naphthalene-type epoxy resin (epoxy equivalent approximately 144 g / eq.), four parts of biphenyl-type epoxy resin (epoxy equivalent approximately 290 g / eq.), and five parts of bisphenol A type epoxy (188 g / eq.) were dissolved in 10 parts of toluene and 10 parts of MEK while stirring and heating. After cooling the resulting solution to room temperature, 35 parts of reactive ester-based curing agent (reactive group equivalent approximately 238 g / eq.), 3 parts of phenol-based curing agent (hydroxyl equivalent approximately 151 g / eq.), 0.5 parts of curing accelerator, 157 parts of silica, 1 part of toughening agent (MBS), and 1 part of cyclic polyimide resin adhesive additive (Arakawa Chemical, PIAD-152H) and 0.5 parts of polycarbodiimide adhesive additive were uniformly dispersed in a high-speed rotary mixer to obtain resin composition 1.

[0066] Examples 2 to 8, and Comparative Examples 1 to 4: The differences between them are shown in Table 1.

[0067] Table 1

[0068] Experimental Test (1) Determination of the coefficient of thermal expansion (CTE) before Tg The resin compositions prepared in the examples and comparative examples were pre-cured by heating at 170°C for 30 minutes, followed by heating at 190°C for 90 minutes to obtain a cured film formed from the cured resin composition. The cured film was cut into pieces 30 mm wide and 40 mm long to obtain evaluation cured material A. The obtained evaluation cured material A was placed in a TMA instrument fixture and a preload force of 0.05 N was applied. First, the system was equilibrated at an initial temperature of 10°C; then, it was heated to 260°C at a heating rate of 10°C / min; after reaching the target temperature, it was immediately cooled back to 10°C at a cooling rate of 10°C / min; finally, it was heated a second time at a heating rate of 10°C / min until the temperature reached 260°C. The second heating curve was recorded, and the coefficient of thermal expansion of the material was calculated based on the slope of the curve in the temperature range of 50°C to 200°C.

[0069] (2) Determination of dielectric loss tangent (Df) The resin compositions prepared in the various examples and comparative examples were pre-cured by heating at 170°C for 30 minutes, followed by heating at 190°C for 90 minutes to obtain a cured film formed from the cured resin composition. The cured film was cut into pieces 30 mm wide and 40 mm long to obtain evaluation cured material B. For the obtained evaluation cured material B, the dielectric loss tangent (Df value) was measured using a Keysight E5071C device at a resonant cavity perturbation method at a measurement frequency of 10 GHz and a measurement temperature of 23°C. Measurements were performed on three samples, and the average value was calculated.

[0070] (3) Determination of elongation at break The resin compositions prepared in the various examples and comparative examples were pre-cured by heating at 170°C for 30 minutes, followed by heating at 190°C for 90 minutes to obtain a cured film formed from the cured resin composition. The cured film was cut into pieces 30 mm wide and 40 mm long to obtain evaluation cured material C. The obtained evaluation cured material C was placed in the tensile mode fixture of a DMA instrument with a preload force of 0.01 N, using force tracking 125%, with the force range set to the current force value to 17.5 N, and a loading speed of 3.0 N / min.

[0071] (4) Roughness evaluation after degumming treatment (roughening treatment) Step 1: Preparation of inner layer substrate: The glass cloth substrate with epoxy resin double copper-clad laminate (board size 12cm×12cm, copper foil thickness 18μm, substrate thickness 0.8mm) with inner layer circuit is etched to 1μm on both sides with micro etchant (MEC company's "CZ8101") to roughen the copper surface.

[0072] Step 2: Using a vacuum leveling machine, the resin sheet manufactured in the examples and comparative examples is laminated onto the inner layer substrate in such a way that the resin composition layer is bonded to the inner layer substrate in (1). The lamination is performed by adjusting the air pressure to below 1.0 MPa by depressurizing for 30 seconds, and then pressing for 30 seconds at a temperature of 115°C and a pressure of 1.0 MPa. Next, it is smoothed by hot pressing at 115°C and a pressure of 1.2 MPa for 60 seconds. Then, it is heated in an oven at 130°C for 30 minutes, and then transferred to an oven at 170°C for 30 minutes, thereby thermally curing the resin composition layer to form an insulating layer. After peeling off the support to expose the insulating layer, the resulting substrate is immersed in a swelling liquid at 70°C for 5 minutes, then immersed in a roughening liquid at 80°C for 20 minutes, and finally immersed in a neutralizing liquid at 45°C for 5 minutes.

[0073] Step 3: Use a white light interferometer to measure the surface roughness of the resin sheet after removing the glue residue.

[0074] (5) Determination of the bonding strength of the conductor layer Step 1: Preparation of inner layer substrate: The glass cloth substrate with double copper-clad laminate (board size 12cm×12cm, copper foil thickness 18μm, substrate thickness 0.8mm) with inner layer circuit is etched to 1μm on both sides with micro etchant (MEC company's "CZ8101") to roughen the copper surface.

[0075] Step 2: Using a vacuum leveling machine, the resin composition layer manufactured in the examples and comparative examples is laminated onto the inner layer substrate in a manner that bonds it to the inner layer substrate in (1). The lamination is performed by adjusting the air pressure to below 1.0 MPa by depressurizing for 30 seconds, and then pressing for 30 seconds at a temperature of 115°C and a pressure of 1.0 MPa. Next, it is smoothed by hot pressing at 115°C and a pressure of 1.2 MPa for 60 seconds. Then, it is heated in an oven at 130°C for 30 minutes, and then transferred to an oven at 170°C for 30 minutes, thereby thermally curing the resin composition layer to form an insulating layer. After peeling off the support to expose the insulating layer, the resulting substrate is immersed in a swelling liquid at 70°C for 5 minutes, then immersed in a roughening liquid at 80°C for 20 minutes, and finally immersed in a neutralizing liquid at 45°C for 5 minutes.

[0076] Step 3: A chemical copper layer with a thickness of 0.6 to 0.9 micrometers is formed on the sample using chemical deposition. A dry film is then laminated onto the copper layer, followed by exposure and development to form a strip pattern 1 cm wide and 10 cm long. The copper layer of the pattern is then thickened to 20 ± 4 micrometers using electroplating. Finally, the unprotected chemical copper layer is removed using flash etching, creating a test sample with isolated copper strips. During testing, a tensile testing machine is used to continuously peel the copper strip 30 mm from the resin surface at a constant speed of 30 mm / min. The force curve during peeling is precisely recorded, and the average force value between 10 mm and 30 mm is calculated as the average peel force. The final peel strength is calculated using the formula "average peel force (gf) / copper strip width (cm)," and the result is expressed in gf / cm. At least three effective copper strips are tested for each sample group, and the arithmetic mean is taken as the final adhesion evaluation index.

[0077] The resin compositions prepared in Examples 1 to 8 and Comparative Examples 1 to 4 were subjected to relevant performance tests, and the test results are shown in Table 1. As can be seen from Table 1, the resin compositions of Examples 1 to 8 contain the adhesive additives (i.e., cyclic polyimide resin and polycarbodiimide) described in this application, which helps to improve the adhesive strength (conductor layer bonding strength) and elongation at break of the resin composition. After removing adhesive residue, the surface roughness of the material is reduced, and the dielectric properties and CET are not significantly improved. This results in the resin composition of this application having both high adhesive strength and elongation at break, and low roughness, dielectric properties, and CET.

[0078] Compared with Comparative Examples 2 and 3, Comparative Example 2 only added cyclic polyimide resin, and Comparative Example 3 only added polycarbodiimide. As shown in Table 1, the composition of Comparative Example 2 with only cyclic polyimide polymer exhibited problems such as low elongation at break, high roughness after desizing, and a large coefficient of thermal expansion. The composition of Comparative Example 3 with only polycarbodiimide also exhibited problems such as low elongation at break, high roughness after desizing, and low adhesion strength to the conductor layer. Example 1, by simultaneously adding cyclic polyimide resin and polycarbodiimide, improved the adhesion strength and elongation at break of the material to the conductor layer, and reduced the roughness after desizing, demonstrating promising results. This is likely because the cyclic polyimide polymer and the polycarbodiimide adhesive enhancer, through the coordination of the lone pair electrons of nitrogen and oxygen atoms in their imide rings and diimide groups with the empty orbitals of copper atoms, form a strong chemisorption layer at the resin / copper interface, significantly improving the adhesion strength. Meanwhile, the synergistic effect of polyimide polymers and polycarbodiimide significantly improves the brittleness of epoxy and reactive ester curing agent resin systems, increases the elongation at break of the composition, and avoids the problem of increased CTE caused by adding polyimide alone while maintaining the low dielectric loss of the resin system. Furthermore, cyclic polyimide polymers and polycarbodiimide are low-polarity polymers, which inherently possess stronger resistance to chemical corrosion, reducing the risk of dissolution during the descaling process and thus ensuring the integrity of the resin surface to achieve low roughness.

[0079] The technical solutions provided by the embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A resin composition, characterized in that, It includes epoxy resin, curing agent, filler, and adhesive additive; wherein the adhesive additive includes cyclic polyimide resin and polycarbodiimide.

2. The resin composition according to claim 1, characterized in that, The adhesive additive accounts for 0.2% to 20% of the non-volatile components in the resin composition, excluding the filler, by weight.

3. The resin composition according to claim 1 or 2, characterized in that, The mass ratio of the cyclic polyimide resin to the polycarbodiimide is 1:(0.1 to 15).

4. The resin composition according to claim 3, characterized in that, The ratio of the cyclic polyimide resin to the total amount of non-volatile components in the resin composition, excluding the filler, is less than 6%.

5. The resin composition according to claim 3, characterized in that, The adhesive additive comprises 1% to 10% of the non-volatile components in the resin composition other than the filler, and the mass ratio of the cyclic polyimide resin to the polycarbodiimide is 1:(0.5 to 8).

6. The resin composition according to claim 5, characterized in that, The ratio of the cyclic polyimide resin to the total amount of non-volatile components in the resin composition, excluding the filler, is greater than or equal to 0.9% and less than or equal to 4%.

7. The resin composition according to claim 1, characterized in that, The epoxy resin includes biphenyl-type epoxy resin, bisphenol A-type epoxy resin, and naphthalene-type epoxy resin.

8. The resin composition according to claim 1, characterized in that, The curing agent also includes at least one of the following: reactive ester curing agent, phenolic curing agent, and carbodiimide curing agent.

9. The resin composition according to claim 1, characterized in that, The epoxy resin accounts for 5.5% to 7.5% of the non-volatile components in the resin composition by weight. And / or, the curing agent accounts for 15% to 19% of the non-volatile components in the resin composition; And / or, the filler constitutes 70% to 80% of the non-volatile components in the resin composition; And / or, the resin composition further includes a curing accelerator, the curing accelerator comprising 0.1% to 1% of the non-volatile components in the resin composition; And / or, the resin composition further includes a toughening agent, the toughening agent comprising 0.4% to 0.8% of the non-volatile components in the resin composition.

10. A cured resin product, characterized in that, The cured resin is formed by curing the resin composition according to any one of claims 1 to 9.

Images