An epoxy resin composition and resin films, laminates and printed circuit boards using the same.

Abstract

This invention provides an epoxy resin composition and resin films, laminates, and printed circuit boards using the same. The epoxy resin composition comprises, by weight, 30-60 parts epoxy resin (A), 5-20 parts arylphenolic resin (B), and 10-40 parts reactive ester compound (C), wherein the arylphenolic resin (B) has a softening point of 67°C-97°C, and the reactive ester compound (C) has a softening point of 130°C-170°C. The resin films, laminates, and printed circuit boards prepared from the resin composition of this invention have low dielectric loss tangent values, which can improve the elastic modulus and mitigate the deterioration of copper foil peel strength and dielectric properties after HAST caused by uneven high-temperature curing.

Description

Technical Field

[0001] This invention belongs to the field of printed circuit board technology, and relates to an epoxy resin composition and resin films, laminates and printed circuit boards using the same. Background Technology

[0002] With the rapid development of the electronics industry, electronic products are becoming lighter, thinner, smaller, denser, safer, and more functional. This requires electronic components to have higher wiring density, higher integration, and higher reliability. Consequently, the metal foil laminates used to manufacture printed circuit boards must have better resistance to damp heat, lower coefficient of thermal expansion, lower dielectric loss tangent, and lower water absorption.

[0003] Epoxy resin has excellent mechanical properties and processability. It is a commonly used matrix resin in the manufacture of metal foil laminates for high-end printed circuit boards. The resin films and laminates made from it are widely used in high-performance printed circuit board materials.

[0004] Epoxy resin compositions have excellent flexibility and chemical resistance, but their cured products have a high dielectric loss tangent, which cannot meet the requirements for low dielectric properties.

[0005] After curing epoxy with reactive ester compounds, a low dielectric loss tangent can be obtained. However, the adhesive film after curing reactive esters is difficult to remove, and the curing is uneven. Furthermore, the bonding reliability is low after surface copper plating. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the present invention aims to provide an epoxy resin composition and resin films, laminates and printed circuit boards using the same.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides an epoxy resin composition comprising, by weight:

[0009] Epoxy resin (A): 30-60 parts by weight;

[0010] Arylalkylphenol resin (B): 5-20 parts by weight;

[0011] Active ester compound (C): 10–40 parts by weight;

[0012] The softening point of the aralkylphenol resin (B) is 67℃~97℃ (e.g. 67℃, 70℃, 72℃, 75℃, 78℃, 80℃, 82℃, 85℃, 88℃, 90℃, 92℃, 95℃ or 97℃), and the softening point of the active ester compound (C) is 130℃~170℃ (e.g. 130℃, 135℃, 140℃, 145℃, 150℃, 155℃, 160℃, 165℃ or 170℃).

[0013] In this invention, by using a combination of low-softening-point aralkylphenol resin and high-softening-point active ester compound, the elastic modulus of the resin composition can be improved. At the same time, the resin composition has good flowability after high-temperature melting, which solves the problem of uneven curing at different locations during high-temperature curing of the resin film, and improves the problem of deterioration of copper foil peel strength and dielectric properties after HAST caused by uneven curing.

[0014] In this invention, the softening point of arylphenolic resins or active ester compounds can be determined by JIS K7234.

[0015] The resin films, laminates, and printed circuit boards prepared by the resin composition of the present invention have low dielectric loss tangent (Df), which can improve the elastic modulus and improve the problem of copper foil peel strength and dielectric properties deterioration after HAST caused by uneven high-temperature curing.

[0016] In some embodiments, the epoxy resin (A) is selected from any one or a combination of at least two of bisphenol A type epoxy resin, bisphenol F type epoxy resin, linear phenolic epoxy resin, dicyclopentadiene type phenolic epoxy resin, biphenyl type phenolic epoxy resin, aralkyl type phenolic epoxy resin or naphthalene type epoxy resin.

[0017] Preferably, the arylalkylphenol resin (B) is a compound represented by the following formula (1).

[0018]

[0019] In the above formula (1), R 6 R 7 Each is independently a hydrogen atom or an alkyl group having 1 to 12 carbon atoms (e.g., 1, 2, 5, 8, 10 or 12), q is an integer from 1 to 50 (e.g., 1, 2, 5, 8, 10, 15, 20, 25, 30, 35, 40, 45 or 50), and X is any group represented by the following formulas (2) to (3).

[0020]

[0021] In equations (2) to (3), R 8 R 11Each is independently an alkyl group having 1 to 12 hydrogen atoms or carbon atoms (e.g., 1, 2, 5, 8, 10 or 12).

[0022] Preferably, the chloride ion content of the arylphenolic resin is less than 10 ppm, for example, it can be 9 ppm, 8 ppm, 7 ppm, 6 ppm, 5 ppm, 4 ppm, 3 ppm, 2 ppm, 1 ppm, 0.5 ppm, etc.

[0023] In this invention, the chloride ion content of the arylphenolic resin is less than 10 ppm, which makes the copper foil circuit less susceptible to chloride ion corrosion during the high temperature and high humidity HAST process, effectively suppressing the decrease in copper foil peel strength after HAST; at the same time, there are fewer large chain segment dipoles formed by chloride ions in the resin composition, and the resin matrix moves slowly during the high temperature HAST process, effectively suppressing the deterioration of dielectric properties after HAST.

[0024] In this invention, the chloride ion content can be determined by using combustion-ion chromatography (according to BS EN 145822007).

[0025] Preferably, the active ester compound comprises any one or a combination of at least two of the dicyclopentadiene-type active ester compounds or the naphthalene-type active ester compounds.

[0026] Preferably, the active ester compound is a compound represented by the following formula (4):

[0027]

[0028] In the formula (4), R is phenyl or naphthyl, j is 0 or 1, k is 0 or 1, and n represents a repeating unit of 0.25 to 1.25 (e.g., 0.25, 0.50, 0.75, 1.00 or 1.25).

[0029] In the epoxy resin composition of the present invention, the content of the epoxy resin (A) may be, for example, 30 parts by weight, 35 parts by weight, 38 parts by weight, 40 parts by weight, 45 parts by weight, 48 parts by weight, 50 parts by weight, 55 parts by weight, 58 parts by weight, or 60 parts by weight.

[0030] In the epoxy resin composition of the present invention, the content of the aralkylphenol resin (B) may be, for example, 5 parts by weight, 8 parts by weight, 10 parts by weight, 12 parts by weight, 15 parts by weight, 18 parts by weight, or 20 parts by weight. If the content of the aralkylphenol resin (B) is too low, the elastic modulus of the resin composition cannot be effectively improved; if the content of the aralkylphenol resin (B) is too high, the Df of the resin composition will be reduced.

[0031] In the epoxy resin composition of the present invention, the content of the active ester compound (C) may be, for example, 10 parts by weight, 15 parts by weight, 18 parts by weight, 20 parts by weight, 23 parts by weight, 25 parts by weight, 28 parts by weight, 30 parts by weight, 35 parts by weight, 38 parts by weight, or 40 parts by weight. If the content of the active ester compound (C) is too low, a resin system with a low Df cannot be obtained; if the content of the active ester compound (C) is too high, the elastic modulus of the resin composition will be reduced.

[0032] The "parts" and "parts by weight" used in this invention are calculated based on solid content and do not include solvents, dispersants, etc.

[0033] Preferably, the epoxy resin composition further includes a carbodiimide compound.

[0034] Preferably, the carbodiimide compound is selected from any one or a combination of two of carbodiimide compounds containing aliphatic or aromatic structures.

[0035] Preferably, the content of the carbodiimide compound is 1 to 20 parts by weight, for example, 1 part by weight, 2 parts by weight, 5 parts by weight, 8 parts by weight, 10 parts by weight, 12 parts by weight, 15 parts by weight, 18 parts by weight or 20 parts by weight.

[0036] Preferably, the epoxy resin composition further includes a thermoplastic resin.

[0037] Preferably, the content of the thermoplastic resin is 1 to 15 parts by weight, for example, 1 part by weight, 2 parts by weight, 5 parts by weight, 8 parts by weight, 10 parts by weight, 12 parts by weight or 15 parts by weight.

[0038] Preferably, the thermoplastic resin is selected from any one or a combination of at least two of phenoxy resin, polyvinyl acetal resin, polyolefin resin, polybutadiene resin, polyimide resin, polyamide-imide resin, polyether-imide resin, polysulfone resin, polyethersulfone resin, polyphenylene ether resin, polycarbonate resin, polyetheretherketone resin, polyester resin, or acrylic resin.

[0039] Preferably, the epoxy resin composition further includes inorganic fillers.

[0040] Preferably, the content of the inorganic filler is 20 to 300 parts by weight, for example, 20 parts by weight, 30 parts by weight, 40 parts by weight, 50 parts by weight, 80 parts by weight, 100 parts by weight, 150 parts by weight, 180 parts by weight, 200 parts by weight, 230 parts by weight, 250 parts by weight, 280 parts by weight, or 300 parts by weight.

[0041] Preferably, the inorganic filler is selected from any one or a combination of at least two of the following: silicon dioxide, aluminum hydroxide, alumina, talc, aluminum nitride, boron nitride, silicon carbide, barium sulfate, barium titanate, strontium titanate, calcium carbonate, calcium silicate, or mica.

[0042] Preferably, the epoxy resin composition further includes any one or a combination of at least two of the following: a curing accelerator, a flame retardant, or a pigment.

[0043] Preferably, the content of the curing accelerator is 0.01-2 parts by weight, for example 0.01 parts by weight, 0.05 parts by weight, 0.1 parts by weight, 0.2 parts by weight, 0.5 parts by weight, 0.8 parts by weight, 1.0 parts by weight, 1.2 parts by weight, 1.5 parts by weight or 2 parts by weight.

[0044] In a second aspect, the present invention provides a resin adhesive obtained by dissolving or dispersing the epoxy resin composition as described in the first aspect in a solvent.

[0045] The conventional preparation method of the resin solution of the present invention is as follows: first, put in the solid material, then add the liquid solvent, stir until the solid material is completely dissolved, then add the liquid resin, inorganic filler and accelerator, and continue to stir until uniform.

[0046] The solvent used in this invention is not particularly limited and can be selected from alcohols such as methanol, ethanol, and butanol; ethyl cellosolve, butyl cellosolve, ethylene glycol methyl ether, carbitol, butyl carbitol, etc.; ketones such as acetone, butanone, methyl ethyl ketone, and cyclohexanone; aromatic hydrocarbons such as toluene and xylene; esters such as ethyl acetate and ethoxyethyl acetate; and nitrogen-containing solvents such as N,N-dimethylformamide and N,N-dimethylacetamide. The above solvents can be used alone or in mixtures of two or more. The amount of solvent added is selected by those skilled in the art based on their experience, ensuring that the resin solution reaches a suitable viscosity for use.

[0047] Thirdly, the present invention provides a resin film comprising a release film and an epoxy resin composition as described in the first aspect, which is attached to the release film after coating and drying.

[0048] Fourthly, the present invention provides a prepreg comprising a reinforcing material and an epoxy resin composition as described in the first aspect, which is attached to the reinforcing material by impregnation and drying.

[0049] Preferably, the reinforcing material includes any one of glass fiber cloth, non-woven fabric, quartz cloth, quartz glass fiber blended fabric, fiber paper, or wood pulp paper.

[0050] Fifthly, the present invention provides a laminate comprising one or at least two laminated prepregs as described in the fourth aspect.

[0051] In a sixth aspect, the present invention provides a metal foil laminate comprising one or at least two stacked prepregs as described in the fourth aspect, and a metal foil covering one or both sides of the prepreg or the stacked prepregs.

[0052] In a seventh aspect, the present invention provides a printed circuit board comprising at least one resin film as described in the third aspect, or comprising one or at least two stacked prepregs as described in the fourth aspect.

[0053] Compared with the prior art, the present invention has the following beneficial effects:

[0054] The resin films, laminates, and printed circuit boards prepared by the resin composition of the present invention have low dielectric loss tangent (Df), which can improve the elastic modulus and improve the problem of copper foil peel strength and dielectric properties deterioration after HAST caused by uneven high-temperature curing. Detailed Implementation

[0055] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0056] The following are some of the material and grade information involved in the embodiments and comparative examples:

[0057] (A) Epoxy resin:

[0058] Bisphenol A type epoxy resin (jER-828EL, Mitsubishi Chemical);

[0059] Biphenyl-type phenolic epoxy resin (NC3000L, Nippon Kayaku).

[0060] (B) Arylalkylphenol resin:

[0061] Phenolic phenyl aralkylphenol resin (ResiCare 3600H, Hengfeng New Materials, softening point 68-78℃, chloride ion content less than 5ppm), structural formula as follows:

[0062]

[0063] Biphenyl alkylphenol resin (GPH-103, Nippon Kayaku, softening point 103℃, chloride ion content less than 9ppm), structural formula as follows:

[0064]

[0065] Biphenyl alkylphenol resin (MEHC-7840-4S, Meiwa Chemical, softening point 58-65℃, chloride ion content less than 7ppm).

[0066] (C) Active ester compounds:

[0067] C-1: The compound represented by formula (4) is a dicyclopentadiene-type active ester compound, prepared according to Comparative Manufacturing Example 1 of JP6862701B2, with a softening point of 150°C.

[0068] C-2: Naphthalene-type active ester compound, prepared according to Example 1 of CN107207703B, with a softening point of 156℃;

[0069] C-3: Phenolic aldehyde type active ester compound, prepared according to Comparative Manufacturing Example 2 of JP6862701B2, with a softening point of 92°C.

[0070] Example 1

[0071] 40 parts by weight of epoxy resin (NC3000L, Nippon Kayaku), 10 parts by weight of aralkylphenol resin (ResiCare3600H, Hengfeng New Materials), 10 parts by weight of carbodiimide compound (V-03, Nisshinbo Chemical), 20 parts by weight of reactive ester resin C-1, 1 part by weight of phenoxy resin (YX7553BH30, Mitsubishi Chemical), 0.3 parts by weight of curing accelerator (DMAP, Guangrong Chemical), and 260 parts by weight of silica (SO-C2, Admatechs) were added to methyl ethyl ketone solvent and stirred for 2 hours to form a solution with a solid content of 65%.

[0072] The above-mentioned resin solution was applied to a release film, dried, and then baked in a 120℃ oven for 5 minutes to obtain a resin film with a semi-cured resin layer. The semi-cured resin film (40μm thick) and the browned PCB board were pressed and cured (temperature 100℃, pressure 0.5MPa, time 1min). The release film was then removed, and surface treatment was performed, including copper plating, to form a multilayer printed circuit board with circuitry.

[0073] Examples 2-3, Comparative Examples 1-3

[0074] A resin composition and a resin film and a printed circuit board comprising the resin composition are disclosed. The components and contents of the resin composition are shown in Table 1, wherein the amount of each component is expressed in "parts by weight" of solid content. The preparation methods of the resin film and the printed circuit board are the same as those in Example 1.

[0075] The following performance tests were performed on the resin films or printed circuit boards provided in Examples 1-3 and Comparative Examples 1-3:

[0076] (1) HAST: Highly Accelerated Temperature and Humidity Stress Test (HAST) was conducted according to JESD22-A110, with a temperature of 130℃ and a humidity of 85%RH for 100 hours.

[0077] (2) Copper foil peel strength PS

[0078] The resin film was pressed onto the surface of the core board and cured in an oven at 180°C for 30 minutes to obtain a pre-cured resin film. The resin film was then subjected to the following desmear treatment: immersion in an aqueous solution of ethylene glycol ethers and sodium hydroxide (MV Sweller, ATOTECH) at 70°C for 10 minutes; rinsing with deionized water for 2 minutes; immersion in a potassium permanganate solution (MV P Etch, ATOTECH) at 80°C for 30 minutes; rinsing with deionized water for 2 minutes; and immersion in an acidic aqueous solution (MV Reduction Cleaner, ATOTECH) at 50°C for 5 minutes to obtain a roughened resin film.

[0079] The roughened resin film was subjected to the following copper plating, electroplating and post-curing treatment: soaking in chemical copper solution (MVTP1, ATOTECH) for 20 min, electroplating copper to a thickness of 25 μm, and curing in an oven at 200℃ for 60 min. The copper plating adhesion of the resin film was tested using the IPC-TM-6502.4.9 method and a copper foil peel strength tester.

[0080] (3) Peel strength PS of copper foil after HAST treatment

[0081] The roughened resin film was subjected to the following copper plating, electroplating, and post-curing treatment: immersion in chemical copper solution (MVTP1, ATOTECH) for 20 min – copper plating thickness of 25 μm – curing in an oven at 200℃ for 60 min, followed by HAST treatment. The copper adhesion of the resin film was tested using a copper foil peel strength tester according to the IPC-TM-650 2.4.9 method.

[0082] (4) Elastic modulus

[0083] After the resin film was cured at 200℃ for 60 minutes, it was tested using the IPC TM650 2.4.24.4 method.

[0084] (5) Dielectric loss tangent Df: After the resin membrane is cured at 200℃ for 60min, the resin membrane sample is tested by SPDR (Split PostDielectric Resonator) method. The test conditions are A state and the frequency is 10GHz, referring to IPC-TM-650 2.5.5.5.

[0085] (6) Dielectric loss tangent Df after HAST processing

[0086] After curing the resin film at 200℃ for 60 minutes, the sample was prepared and subjected to HAST treatment. The SPDR (Split PostDielectric Resonator) method was used for testing under the conditions of A state and 10 GHz, in accordance with IPC-TM-6502.5.5.5.

[0087] The test results of the resin films or printed circuit boards in Examples 1-3 and Comparative Examples 1-3 are shown in Table 1:

[0088] Table 1

[0089]

[0090]

[0091] As can be seen from Table 1, the resin films and printed circuit boards prepared by the resin compositions of Examples 1-3 of the present invention have low dielectric loss tangent values ​​and high elastic modulus. After HAST treatment, the deterioration of copper foil peel strength and Df can be significantly suppressed. The copper foil peel strength is 6.0-6.6 N / cm, and the copper foil peel strength after HAST treatment is 5.5-6.1 N / cm. The elastic modulus is 12.6-14.5 GPa, and the Df is 0.0038-0.0044. After HAST treatment, the Df is 0.0051-0.0059.

[0092] Compared with Example 1, Comparative Examples 1-2 used aralkylphenol resins with higher and lower softening points, respectively, which significantly deteriorated the peel strength and Df of the copper foil after HAST treatment of the resin film.

[0093] Compared with Example 1, Comparative Example 3 used an active ester compound with a lower softening point, which reduced the elastic modulus of the resin film and significantly worsened the peel strength and Df of the copper foil after HAST treatment.

[0094] The applicant declares that the present invention is illustrated through the above embodiments to demonstrate the epoxy resin composition of the present invention and the resin film, laminate, and printed circuit board using it. However, the present invention is not limited to the above embodiments, that is, it does not mean that the present invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials of the products of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. An epoxy resin composition, characterized in that, The epoxy resin composition comprises, by weight, the following: Epoxy resin (A): 30~60 parts by weight; Arylalkylphenol resin (B): 5~20 parts by weight; Active ester compound (C): 10~40 parts by weight; Among them, the softening point of aralkylphenol resin (B) is 67℃~97℃, and the softening point of active ester compound (C) is 130℃~170℃. The chloride ion content of the alkylphenol resin is less than 10 ppm; The epoxy resin (A) is selected from any one or a combination of at least two of the following: bisphenol A type epoxy resin, bisphenol F type epoxy resin, linear phenolic epoxy resin, dicyclopentadiene type phenolic epoxy resin, biphenyl type phenolic epoxy resin, aralkyl type phenolic epoxy resin, or naphthalene type epoxy resin.

2. The epoxy resin composition according to claim 1, characterized in that, The arylalkylphenol resin (B) is a compound represented by the following formula (1). Equation (1) In the above formula (1), R 6 R 7 Each is independently a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, q is an integer from 1 to 50, and X is any group represented by the following formulas (2) to (3). Equation (2) Equation (3) In equations (2) to (3), R 8 R 11 Each is independently an alkyl group having 1 to 12 hydrogen atoms or carbon atoms.

3. The epoxy resin composition according to claim 1, characterized in that, The active ester compound comprises any one or a combination of at least two of the dicyclopentadiene-type active ester compounds or the naphthalene-type active ester compounds.

4. The epoxy resin composition according to claim 1, characterized in that, The active ester compound is a compound represented by the following formula (4): Equation (4) In the formula (4), R is phenyl or naphthyl, j is 0 or 1, k is 0 or 1, and n represents a repeating unit of 0.25~1.

25.

5. The epoxy resin composition according to claim 1, characterized in that, The epoxy resin composition also includes a carbodiimide compound.

6. The epoxy resin composition according to claim 5, characterized in that, The carbodiimide compound is selected from any one or a combination of two of carbodiimide compounds containing aliphatic or aromatic structures.

7. The epoxy resin composition according to claim 5, characterized in that, The content of the carbodiimide compound is 1 to 20 parts by weight.

8. The epoxy resin composition according to claim 1, characterized in that, The epoxy resin composition also includes a thermoplastic resin.

9. The epoxy resin composition according to claim 8, characterized in that, The content of the thermoplastic resin is 1 to 15 parts by weight.

10. The epoxy resin composition according to claim 8, characterized in that, The thermoplastic resin is selected from any one or a combination of at least two of the following: phenoxy resin, polyvinyl acetal resin, polyolefin resin, polybutadiene resin, polyimide resin, polyamide-imide resin, polyether-imide resin, polysulfone resin, polyethersulfone resin, polyphenylene ether resin, polycarbonate resin, polyether ether ketone resin, polyester resin, or acrylic resin.

11. The epoxy resin composition according to claim 1, characterized in that, The epoxy resin composition also includes inorganic fillers.

12. The epoxy resin composition according to claim 11, characterized in that, The content of the inorganic filler is 20-300 parts by weight.

13. The epoxy resin composition according to claim 11, characterized in that, The inorganic filler is selected from any one or a combination of at least two of the following: silicon dioxide, aluminum hydroxide, aluminum oxide, talc, aluminum nitride, boron nitride, silicon carbide, barium sulfate, barium titanate, strontium titanate, calcium carbonate, calcium silicate, or mica.

14. The epoxy resin composition according to claim 1, characterized in that, The epoxy resin composition further includes any one or a combination of at least two of the following: a curing accelerator, a flame retardant, or a pigment.

15. The epoxy resin composition according to claim 14, characterized in that, The content of the curing accelerator is 0.01-2 parts by weight.

16. A resin adhesive, characterized in that, The resin solution is obtained by dissolving or dispersing the epoxy resin composition as described in any one of claims 1-15 in a solvent.

17. A resin film, characterized in that, The resin film includes a release film and an epoxy resin composition as described in any one of claims 1-15, which is applied to and dried on the release film.

18. A prepreg, characterized in that, The prepreg includes a reinforcing material and an epoxy resin composition as described in any one of claims 1-15, which is attached to the reinforcing material after impregnation and drying.

19. A laminate, characterized in that, The laminate comprises one or at least two laminated prepregs as described in claim 18.

20. A metal foil-coated laminate, characterized in that, The metal foil laminate includes one or at least two stacked prepregs as described in claim 18, and a metal foil covering one or both sides of the prepreg or the stacked prepregs.

21. A printed circuit board, characterized in that, The printed circuit board includes at least one resin film as described in claim 17, or includes one or at least two stacked prepregs as described in claim 18.

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