Thermosetting resin composition, insulating film containing the same, and printed circuit board

Abstract

This specification relates to a thermosetting resin composition comprising an epoxy resin as a curable resin, a cyanate ester resin and a phenol resin as curing agents, and silica having an average particle size of 0.1 μm or more and less than 0.2 μm as an inorganic filler, as well as an insulating film and a printed circuit board containing the same. The thermosetting resin composition according to the above-described embodiment can ensure excellent curing properties and excellent high-temperature reliability.

Description

Technical Field

[0001] This specification relates to a thermosetting resin composition, an insulating film containing the same, and a printed circuit board.

[0002] This application claims the benefit of the filing dates of Korean Patent Application Nos. 10-2023-0171426 and 10-2024-0143082, respectively filed with the Korean Intellectual Property Office on November 30, 2023 and October 18, 2024, and all of its contents are incorporated herein.

Background Art

[0003] A printed circuit board (PCB) refers to a board that serves as a support for electronic components, fixes the electronic components on the surface of the printed wiring board, and connects the components with copper wiring to form an electronic circuit.

[0004] Generally, a printed circuit board is basically formed by insulating between copper wirings to form multiple layers. In order to improve the reliability of the substrate, methods for improving the adhesion between the insulating layer and the copper foil layer have been proposed, such as including a component with a high binding force to Cu in the insulating layer or forming the roughness of the insulating layer surface to increase the surface area of the interface.

[0005] As a method for manufacturing a multilayer printed circuit board, a method is known in which a prepreg sheet is laminated on an inner layer circuit board on which a copper foil circuit is formed, and the interlayer connection is performed by through-holes. However, this method requires large-scale equipment, consumes a large amount of cost and time, and has a problem that it is difficult to form a fine pattern.

[0006] In recent years, as a method for solving the above problems, a method for manufacturing a multilayer printed circuit board incorporating a build-up method has been proposed. This is a technique in which an organic insulating layer (or an insulating film) is alternately laminated on the conductor layer of the circuit board.

[0007] Generally, the manufacturing process for build-up multilayer printed circuit boards involves the following steps: vacuum lamination of build-up insulating film onto the inner layer circuitry; precure; drilling; desmear; electroless plating; electrolytic plating; postcure; and outer layer circuit formation.

[0008] The aforementioned desmearing step is an essential process for removing smear (residue derived from resin components contained in the insulating film) from the insulating film using an acidic solution. This chemical treatment erodes a certain portion of the insulating film surface, forming a certain level of roughness. This roughness formed on the insulating film surface plays a role in improving the adhesion to the copper foil layer that will follow.

[0009] Initially, resin compositions for the aforementioned build-up insulating films consisted of epoxy resin and a phenolic curing agent, with silica particles filled as an inorganic filler. However, with the increasing demand for low dielectric properties and low CTE, there is a growing trend towards developing products that use a cyanate ester curing agent in the epoxy resin.

[0010] However, even though cured products of epoxy resin and cyanate ester resin have advantages such as low CTE and low Df, they are easily hydrolyzed by residual moisture at high temperatures, which can lead to problems such as gas generation, blister formation, and deterioration of mechanical properties, resulting in reduced durability and / or reliability in high-temperature environments.

[0011] Using large-particle inorganic fillers offers advantages in terms of easily controlling surface roughness formed during the desmear stage and improving adhesion to the copper foil layer. However, it presents a problem in that the shedding of inorganic filler particles during laser drilling makes it difficult to process fine-sized via holes. To improve this, using small-particle inorganic fillers between 0.1 μm and 0.2 μm results in excessively low surface roughness after the desmear process, leading to a decrease in the interlocking effect at the interface with the copper foil layer. Consequently, the aforementioned reliability issues can become even more critical.

[0012] Therefore, it is necessary to develop materials that improve durability and / or reliability in high-temperature environments while ensuring advantages such as low CTE and low Df. [Overview of the project] [Problems that the invention aims to solve]

[0013] This specification relates to a thermosetting resin composition for solving the aforementioned problems, an insulating film containing the same, and a printed circuit board. [Means for solving the problem]

[0014] The inventors have confirmed that when using epoxy resin as the curable resin, cyanate ester resin and phenol resin, styrene-maleic anhydride copolymer, and silica having an average particle size of 0.1 μm or more and less than 0.2 μm as the curing agent, the cured product has the advantages of conventional epoxy resin and cyanate ester resin, such as low CTE and low Df, while ensuring a certain level of durability and / or reliability in high-temperature environments.

[0015] Therefore, in order to resolve the conventional problems, embodiments of this specification are as follows. One embodiment of this specification provides a thermosetting resin composition comprising a curable resin, a curing agent, a styrene-maleic anhydride copolymer (SMA), and an inorganic filler, wherein the curable resin comprises an epoxy resin and a phenolic resin, the curing agent comprises a cyanate ester resin, and the inorganic filler comprises silica having an average particle size of 0.1 μm or more and less than 0.2 μm.

[0016] Other embodiments of this specification provide an insulating film comprising the thermosetting resin composition and its cured product described above. Another embodiment of this specification provides a printed circuit board including the aforementioned insulating film. [Effects of the Invention]

[0017] The thermosetting resin composition described herein has excellent curing properties such as a low coefficient of thermal expansion (Low CTE), a low dielectric constant (Low Df), and a high glass transition temperature (High Tg). Therefore, in the future, it will be possible to reduce warping when insulating films using this composition are used on printed circuit boards.

[0018] Furthermore, since the thermosetting resin composition according to this specification exhibits excellent durability at high temperatures (approximately 200°C or higher), it will be possible to improve the reliability of insulating films using this composition when used in printed circuit boards in the future.

[0019] Furthermore, since the thermosetting resin composition according to this specification also exhibits excellent adhesion to copper foil, it can provide the advantage of preventing defects such as blistering when insulating films using it are used on printed circuit boards in the future. [Modes for carrying out the invention]

[0020] The following provides a more detailed description of this specification. <Thermosetting resin composition> A thermosetting resin composition according to one embodiment of this specification will be described below. A thermosetting resin composition according to one embodiment of this specification is characterized by comprising an epoxy resin as a curable resin, a cyanate ester resin and a phenol resin as curing agents, and silica having an average particle size of 0.1 μm or more and less than 0.2 μm as an inorganic filler.

[0021] When the composition is as described above, it is possible to simultaneously obtain excellent curing properties (low coefficient of thermal expansion, low dielectric constant, and high glass transition temperature), as well as excellent high-temperature durability and reliability.

[0022] According to other embodiments of this specification, the average particle size of the silica may be less than 0.2 μm, 0.19 μm or less, or 0.18 μm or less, or 0.1 μm or more.

[0023] When the silica has an average particle size within the above range, it is possible to form a certain level of surface roughness even after desmear, which is required for recent printed circuit boards for fine patterns. When using silica with an average particle size of at least 0.2 μm or more, the surface roughness is formed too high by desmear, and due to the dropout of large silica particles during laser drilling, it may become difficult to perform via hole processing of a desired size. Also, when using silica with an average particle size of less than at least 0.1 μm, the surface roughness may be formed too low by desmear, or the dielectric loss may increase, or the adhesion of the copper foil may deteriorate. Furthermore, when using silica with an average particle size of 0.01 μm or less, film processing itself may become difficult due to the problem of increased solution viscosity.

[0024] In this specification, the epoxy resin is not particularly limited as long as it is known in the art, and examples include naphthalene type, phenol type, olefin type, DGEBA (diglycidyl ether of bisphenol A) type, DGEBF (diglycidyl ether of bisphenol F) type, phenol novolac type, cresol novolac type, bisphenol type, rubber-modified type, etc. One type of epoxy resin of the type exemplified above may be used alone, or two or more types may be mixed and used.

[0025] In this specification, the cyanate ester resin is not particularly limited as long as it is known in the art, and examples include novolac type, dicyclopentadiene type, bisphenol type (such as bisphenol A type, bisphenol F type, bisphenol S type), prepolymers in which a part of the cyanate ester resin of the type exemplified above is converted to triazine, etc. One type of cyanate ester resin of the type exemplified above may be used alone, or two or more types may be mixed and used.

[0026] In this specification, the styrene-maleic anhydride copolymer (SMA) is not particularly limited as long as it is known in the art. Examples include NST-438, SMAEF30, SMAEF40, SMAEF60, SMAEF80, SMA1000, SMA2000, etc. One of the SMAs exemplified above may be used alone, or two or more thereof may be mixed and used.

[0027] According to one embodiment of this specification, the styrene-maleic anhydride copolymer may contain 10% or more and 40% or less of maleic anhydride (based on the total styrene-maleic anhydride copolymer).

[0028] When the content of maleic anhydride in the styrene-maleic anhydride copolymer is less than 10%, the effect of improving high-temperature durability by addition is negligible. When it exceeds 40%, the mechanical properties of the final cured product may deteriorate.

[0029] According to one embodiment of this specification, the content of the styrene-maleic anhydride copolymer may be 5 parts by weight or more and less than 40 parts by weight with respect to 100 parts by weight of the cyanate ester resin.

[0030] When the content of the styrene-maleic anhydride copolymer is less than 5 parts by weight with respect to 100 parts by weight of the cyanate ester resin, the effect of improving high-temperature durability is negligible. When it exceeds 40 parts by weight, the mechanical properties of the final cured product may deteriorate.

[0031] According to one embodiment of this specification, the curing agent further contains a phenolic resin, and the weight ratio of the cyanate ester resin to the phenolic resin may be 95:5 to 40:60. Preferably, the weight ratio of the cyanate ester resin to the phenolic resin may be 90:10 to 60:40, or 85:25 to 70:30.

[0032] When a phenolic resin is mixed with a cyanate ester resin, which acts as a curing agent, within the aforementioned weight ratio range, the curing rate of the cyanate ester resin is accelerated, and cured products with various mechanical properties can be obtained depending on the type and content of the phenolic resin used. Furthermore, as mentioned above, in a preferred range, when the content of the phenolic resin is less than the content of the cyanate ester resin, fewer hydrophilic OH groups can be formed after curing with epoxy, making it even easier to achieve the desired low Df characteristics.

[0033] According to one embodiment of this specification, the phenol resin may include a compound comprising a phenol skeleton, a naphthol skeleton, or a novolac skeleton. According to one embodiment of this specification, the phenolic resin may be a compound containing a novolac skeleton. When the phenolic resin contains the aforementioned skeleton, heat resistance, water resistance, and other properties can be improved.

[0034] According to one embodiment of this specification, the weight ratio of the epoxy resin to the cyanate ester resin may be 60:40 to 20:80.

[0035] When the weight ratio of epoxy resin to cyanate ester resin falls within the aforementioned range, no unreacted epoxy resin remains after curing, leading to further improvements in dielectric properties and mechanical properties, and also contributing to improved high-temperature durability. Furthermore, excessive self-crosslinking of the cyanate ester resin is controlled, preventing brittle fracture, which can easily cause the film to break after curing.

[0036] According to one embodiment of this specification, the thermosetting resin composition further comprises additives, the additives may be selected from the group consisting of curing accelerators, leveling agents, wetting agents, antistatic agents, thermoplastic polymer resins, and antioxidants.

[0037] In this specification, the curing accelerator is a substance that promotes the curing reaction of the thermosetting resin composition together with the curing agent, and is not particularly limited as long as it is known in the industry, but examples include imidazole compounds, amine compounds, organophosphine compounds, and metal compounds, and one of the curing accelerators exemplified above may be used alone, or two or more may be used in mixture.

[0038] The imidazole compounds include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole trimellitate, 1-cyanoethyl-2-phenylimidazole trimellitate, 2,4-diamino- 6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-undecylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine with isocyanuric acid Additives include 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline, and 2-phenylimidazolin.

[0039] Examples of the aforementioned amine compounds include triethylamine, tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, and 1,8-diazabicyclo(5,4,0)-undecene.

[0040] Examples of the aforementioned metallic compounds include organometallic complexes or organometallic salts of metals such as cobalt, copper, zinc, iron, nickel, manganese, and tin. Specific examples of the aforementioned organometallic complexes include cobalt(II) acetylacetonate, cobalt(III) acetylacetonate, copper(II) acetylacetonate, zinc(II) acetylacetonate, iron(III) acetylacetonate, nickel(II) acetylacetonate, and manganese(II) acetylacetonate. Examples of the aforementioned organometallic salts include zinc octoate, tin octoate, zinc naphthenate, cobalt naphthenate, tin stearate, and zinc stearate.

[0041] Furthermore, assuming that the non-volatile content in the thermosetting resin composition is 100% by mass, the curing accelerator may be used in an amount ranging from 0.01% to 5%.

[0042] In this specification, the leveling agent and wetting agent are substances that improve coating processability and coating appearance by adjusting the surface tension, fluidity, ductility, etc., of the curable resin composition, and are not particularly limited as long as they are known in the industry.

[0043] In this specification, the antistatic agent is a substance that imparts an antistatic effect and is not particularly limited as long as it is known in the industry. In some cases, one or more antistatic agents may be used in combination.

[0044] In this specification, the thermoplastic polymer resin may be included to improve the mechanical strength, film-forming ability, etc., of the curable resin composition, and is not particularly limited as long as it is known in the industry, but examples include phenoxy resin, polyvinyl acetal resin, polyvinyl butyral resin, polyimide resin, polyamide-imide resin, polyetherimide resin, polysulfone resin, polyethersulfone resin, polyphenylene ether resin, polycarbonate resin, polyetheretherketone resin, and polyester resin. In some cases, one or more thermoplastic polymer resins may be used as a mixture. The thermoplastic resin preferably contains phenoxy resin. The weight-average molecular weight of the thermoplastic resin may be 5,000 g / mol to 200,000 g / mol, but is not limited thereto.

[0045] In this specification, the antioxidant is a substance that improves thermal stability and is not particularly limited as long as it is known in the art. In some cases, one or more antioxidants may be used in combination.

[0046] In one embodiment of this specification, the thermosetting resin composition may contain a solvent. In this specification, if the thermosetting resin composition contains a solvent, the solvent is not particularly limited as long as it is known in the art to which the present invention belongs as enabling the formation of a thermosetting resin composition. Examples of the solvent include, but are not limited to, one or more compounds selected from the group consisting of esters, ethers, ketones, aromatic hydrocarbons, and sulfoxides.

[0047] The ester solvents include ethyl acetate, n-butyl acetate, isobutyl acetate, amyl formate, isoamyl acetate, isobutyl acetate, butyl propionate, isopropyl butyrate, ethyl butyrate, butyl butyrate, methyl lactate, ethyl lactate, γ-butyrolactone, ε-caprolactone, δ-valerolactone, alkyl oxyacetates (e.g., methyl oxyacetate, ethyl oxyacetate, butyl oxyacetate (e.g., methyl methoxyacetate, ethyl methoxyacetate, butyl methoxyacetate, methyl ethoxyacetate, ethyl ethoxyacetate, etc.)), alkyl 3-oxypropionate esters (e.g., methyl 3-oxypropionate, ethyl 3-oxypropionate, etc. (e.g., methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate) It may also be ethyl oxypropionate, alkyl esters of 2-oxypropionate (e.g., methyl 2-oxypropionate, ethyl 2-oxypropionate, propyl 2-oxypropionate, etc. (e.g., methyl 2-methoxypropionate, ethyl 2-methoxypropionate, propyl 2-methoxypropionate, methyl 2-ethoxypropionate, ethyl 2-ethoxypropionate)), methyl 2-oxy-2-methylpropionate and ethyl 2-oxy-2-methylpropionate (e.g., methyl 2-methoxy-2-methylpropionate, ethyl 2-ethoxy-2-methylpropionate, etc.), methyl pyruvate, ethyl pyruvate, propyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl 2-oxobutanoate, ethyl 2-oxobutanoate, etc.).

[0048] The ether solvent may be diethylene glycol dimethyl ether, tetrahydrofuran, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, etc.

[0049] The ketone solvent may be methyl ethyl ketone (MEK), cyclohexanone, cyclopentanone, 2-heptanone, 3-heptanone, N-methyl-2-pyrrolidone, or the like. The aromatic hydrocarbon solvent may be toluene, xylene, anisole, limonene, or the like. The sulfoxide solvent may be dimethyl sulfoxide or the like.

[0050] <Insulating film> The following describes an insulating film according to one embodiment of this specification. One embodiment of this specification provides an insulating film comprising the aforementioned thermosetting resin composition, specifically a build-up insulating film.

[0051] The insulating film according to this specification can be processed in the following order on a circuit board to manufacture a printed circuit board: vacuum lamination, precure, drilling, desmear, electroless plating, electroplating, postcure, and outer layer circuit formation.

[0052] In this specification, the insulating film can have the following cured properties by thermocuring (for example, thermocuring at a temperature of 190°C to 200°C for 90 minutes or more).

[0053] In one embodiment of this specification, the insulating film cured under conditions of 10 GHz may have a CTE (coefficient of thermal expansion) value of 45 ppm / °C or less.

[0054] In other embodiments of this specification, the coefficient of thermal expansion (relative to the insulating film) measured in the cured state is 40 ppm / °C or less, 35 ppm / °C or less, or 30 ppm / °C or less, and may be 15 ppm / °C or more.

[0055] When the thermal expansion coefficient is within the aforementioned range, the difference in thermal expansion coefficient with that of the copper foil is small, which has the advantage of resulting in less warping after lamination with the copper foil layer.

[0056] Specifically, the coefficient of thermal expansion can be measured using a thermomechanical analyzer (TMA) in the temperature range of 25°C to 120°C after the insulating film has been heat-cured at a temperature of 190°C for 90 minutes.

[0057] In one embodiment of this specification, the insulating film cured under conditions of 10 GHz may have a Dk (Dielectric Constant) value of 3.5 or less and a Df (Dissipation Factor) value of 0.015 or less.

[0058] In other embodiments of this specification, the Dk value of the insulating film measured in the cured state is 3.4 or less, 3.3 or less, or 3.2 or less, and may be 2.4 or more.

[0059] In other embodiments of this specification, the Df value of the insulating film is 0.0145 or less, or 0.014 or less, and may be 0 or greater.

[0060] When the dielectric constant and dielectric loss tangent within the aforementioned range are satisfied, it is advantageous for supporting fine wiring and high-speed transmission for high integration and high density semiconductor chips.

[0061] According to one embodiment of this specification, the difference in adhesion force of the insulating film to the copper foil may satisfy the following formula 1. A2 / A1>0.75 (Formula 1) In the above formula 1, A1 is the initial copper foil adhesion strength (gf / cm) measured after copper plating on at least one side of the insulating film, and A2 is the later copper foil adhesion strength (gf / cm) measured after the insulating film has undergone a Hot Air Reflow Test (performed 10 times at a maximum temperature of 260°C).

[0062] If the above range is met, the insulating film can be evaluated as having high high-temperature durability.

[0063] In one embodiment of this specification, the average value of the arithmetic mean roughness (Ra) of the desmeared insulating film surface, measured using an Optical Profiler (Nanoview 3D surface profiler NV-2700, Nanosystem), is 80 nm or more, 100 nm or more, or 120 nm or more, and may be 500 nm or less, 400 nm or less, or 300 nm or less.

[0064] If the surface roughness of the insulating film after desmearing is less than 80 nm, the interlocking effect at the interface with the copper foil decreases, leading to further reliability problems. If the surface roughness formed after desmearing exceeds 500 nm, although the adhesion to the copper foil is excellent, the plating removal time becomes longer when flash etching is performed after electroplating, and the wiring shape becomes thinner, making it difficult to apply to the fine line widths of less than 10 μm that are required in recent years.

[0065] <Printed circuit board> A printed circuit board according to one embodiment of this specification will be described below. Since the printed circuit board includes an insulating film formed from the thermosetting resin composition described above, the contents of the thermosetting resin composition described above can be applied. [Examples]

[0066] The following describes the Specification in detail with reference to examples. However, the examples described herein can be modified in various other forms, and the scope of this Specification is not to be construed as being limited to the examples described below. The examples described herein are provided to give a more complete explanation of this Specification to a person of average knowledge in the industry.

[0067] <Examples> Example 1: Preparation of thermosetting resin composition 1 The curable epoxy resins consist of 70 parts by weight of bisphenol epoxy resin (YD-128, KUKDO CHEMICAL) and 30 parts by weight of phenol novolac type epoxy resin (YDPN-639, KUKDO CHEMICAL), 112 parts by weight of dicyclopentadiene bisphenol cyanate ester resin (MEK solution with 75% non-volatile components, CO3CS, TECHIA) and 24 parts by weight of biphenyl phenol resin (GPH-65, Nippon Kayaku) as curing agents, 14 parts by weight of styrene-maleic anhydride copolymer (MEK solution with 60% non-volatile components, NST-438, NANOKOR), and 385 parts by weight of silica slurry with an average particle size of 0.18 μm (MEK solution with 60% non-volatile components, K180SX-CM3, ADMATECHS) as an inorganic filler, and phenoxy resin (YP-50, KUKDO) as an additive (thermoplastic polymer resin). 15 parts by weight of chemical (CHEMICAL) and 126 parts by weight of MEK (methyl ethyl ketone) as a solvent were mixed, and the mixture was stirred in a mechanical stirrer at 250 rpm for 3 hours.

[0068] Subsequently, 1.0 part by weight of an imidazole-based curing accelerator (2PHZ-PW, Shikoku Chemicals) and 0.05 parts by weight of an inorganic metal-based curing accelerator, Cobalt(II) acetylacetonate (TCI), were added and uniformly dispersed in a high-speed rotary mixer to produce thermosetting resin composition 1.

[0069] Examples 2-5: Preparation of thermosetting resin compositions 2-5 Thermosetting resin compositions 2 to 5 were manufactured in the same manner as in Example 1, except that the type and content of each component (based on 100 parts by weight of curable resin (epoxy resin)) were changed as shown in Table 1 below.

[0070] Example 6: Preparation of thermosetting resin composition 6 Thermosetting resin composition 6 was prepared in the same manner as in Example 1, except that the type and content of each component (based on 100 parts by weight of curable resin (epoxy resin)) and the amount of 385 parts by weight of silica slurry with an average particle size of 0.1 μm (MEK solution with 60% non-volatile components, SC2050-MB, ADMATECHS) as an inorganic filler were changed as shown in Table 1 below.

[0071] Comparative Example 1: Production of Thermosetting Resin Composition A Thermosetting resin composition A was prepared in the same manner as in Example 1, except that the styrene-maleic anhydride resin was omitted and the content of phenoxy resin (YP-50, KUKDO CHEMICAL) was changed to 23 parts by weight as shown in Table 1 below.

[0072] Comparative Example 2: Production of Thermosetting Resin Composition B Thermosetting resin composition B was prepared in the same manner as in Example 1, except that 330 parts by weight of silica slurry with an average particle size of 0.5 μm (MEK solution with 70% non-volatile components, SC2050-MB, ADMATECHS) was used as the inorganic filler, and 181 parts by weight of MEK (methyl ethyl ketone) was used as the solvent, as shown in Table 1 below.

[0073] Comparative Example 3: Production of Thermosetting Resin Composition C Thermosetting resin composition C was prepared in the same manner as in Example 1, except that 462 parts by weight of silica slurry with an average particle size of 0.05 μm (MEK solution with 50% non-volatile components, Y50SZ-AM1, ADMATECHS) was used as the inorganic filler, and 49 parts by weight of MEK (methyl ethyl ketone) was used as the solvent, as shown in Table 1 below.

[0074] Comparative Example 4: Production of Thermosetting Resin Composition D Thermosetting resin composition D was prepared in the same manner as in Example 1, except that the cyanate ester resin was omitted, and the content of the phenol resin (GPH-65, Nippon Kayaku) was changed to 108 parts by weight and the solvent to 154 parts by weight of MEK (methyl ethyl ketone) as shown in Table 1 below.

[0075] Comparative Example 5: Production of Thermosetting Resin Composition E Thermosetting resin composition E was prepared in the same manner as in Example 1, except that the phenolic resin was omitted, and the content of the cyanate ester resin (MEK solution with 75% non-volatile components, CO3CS, TECHIA) was changed to 144 parts by weight, and the solvent was changed to 118 parts by weight of MEK (methyl ethyl ketone) as shown in Table 1 below.

[0076] [Table 1A] [Table 1B]

[0077] Styrene-maleic anhydride copolymer NST-414 (MEK solution with 60% non-volatile components, maleic anhydride content 19% by weight, NANOKOR) Styrene-maleic anhydride copolymer NST-438 (MEK solution with 60% non-volatile components, maleic anhydride content 11% by weight, NANOKOR)

[0078] <Example of experiment> 1. Sample manufacturing: Manufacturing of insulating film The thermosetting resin compositions produced in Examples 1-6 and Comparative Examples 1-5 were used as coating liquids and coated onto a 38 μm thick support film (PET film) using an applicator. After drying at 100°C for 8 minutes, insulating film samples with a thickness of 25 μm were produced.

[0079] 2. Experimental Example 1: Measurement of Dielectric Constant (Dk and Df) The insulating film samples were heat-cured at 190°C for 90 minutes, and then the dielectric constant (Dk) and dielectric loss (Df) were measured at 10 GHz using an SPDR resonator. The measurement results are shown in Table 2 below.

[0080] 3. Experimental Example 2: Measurement of the Coefficient of Thermal Expansion (CTE) Each of the aforementioned insulating film samples was heat-cured at 190°C for 90 minutes. Then, the coefficient of thermal expansion was measured using a TMA (TA Corporation TMA Q400) at a heating rate of 10°C / min in the range of 25°C to 120°C. The measurement results are shown in Table 2 below.

[0081] 4. Experimental Examples 3 and 4: High-Temperature Reliability Evaluation 1) Desmear treatment Each of the aforementioned insulating film samples was laminated onto a copper clad laminate (CCL) substrate using a vacuum laminator at a temperature of 100°C and a pressure of 0.7 MPa for 30 seconds. After lamination, the samples were pre-cured in a hot air oven at 100°C for 30 minutes, followed by pre-curing at 170°C for 30 minutes. Next, the insulating support film (PET film) was peeled off to expose the insulating layer, and then desmear treatment was performed. The desmear treatment was carried out using Atotech's Securiganth MV series treatment solutions in the following order: swelling solution treatment (60°C, 5 minutes), oxidizing solution treatment (80°C, 20 minutes), and neutralizing solution treatment (50°C, 4 minutes).

[0082] 2) Measurement of surface roughness (Ra, nm) (Experimental Example 3) The surface of the desmeared insulating layer was measured five times per sample using an Optical Profiler (Nanoview 3D surface profiler NV-2700, Nanosystem), and the arithmetic mean roughness (Ra) was calculated from the average value.

[0083] 3) Copper plating treatment Copper plating was performed in two stages: electroless chemical copper plating and electroplating. For the electroless chemical copper plating, Atotech's Printoganth MV product was used to achieve a plating thickness of 1.0 μm, and after processing, the parts were dried in a 150°C hot air oven for 30 minutes. Electroplating was performed using Atotech's Expt Inpro SAP6 chemical to achieve a plating thickness of approximately 20 μm. After the plating process, the material was heat-treated in a hot air oven set to 190°C for 1 hour.

[0084] 4) High-temperature reliability evaluation High-temperature reliability evaluation of copper-plated samples was performed using a Hot Air Reflow Test Machine (SEF Corporation). The test conditions were a maximum temperature of 260°C, a line speed of 20 cm / min, a line length of 100 cm, and a pass time of 5 minutes. After passing each sample through the machine 10 times, the appearance and copper foil adhesion were checked to determine the high-temperature reliability.

[0085] 5) Determination of high-temperature reliability (Experimental Example 4) The 90-degree peel strength of the copper plating layer was measured using a Stable Micro Systems Texture Analyzer (TA-XT Plus). High-temperature reliability was determined by the difference between the initial copper foil adhesion strength (A1 = adhesion strength measured after copper plating) and the later copper foil adhesion strength (A2) described in the high-temperature reliability evaluation above.

[0086] Measurements were taken before and after the high-temperature reliability evaluation, and the copper foil adhesion was judged to be poor if it decreased by 25% or more after the high-temperature reliability evaluation. In other words, it was judged to be poor if the following formula was not satisfied. A2 / A1>0.75 (Formula 1) In the above formula 1, A1 is the initial copper foil adhesion force (gf / cm) measured after copper plating on at least one side of the insulating film. A2 is the late copper foil adhesion strength (gf / cm) measured after passing the insulating film through a Hot Air Reflow Test Machine (SEF Corporation) 10 times under the conditions of a maximum temperature of 260°C, a line speed of 20 cm / min, a line length of 100 cm, and a pass time of 5 minutes per pass.

[0087] Furthermore, if the initial copper foil adhesion strength was less than 400 gf / cm, it was judged as defective, and high-temperature reliability evaluation was not performed.

[0088] Furthermore, after the high-temperature reliability evaluation, the appearance was checked, and if any surface defects such as blister formation or lifting of the copper foil occurred, the high-temperature reliability was determined to be poor. The results of the evaluation are shown in Table 2 below.

[0089] [Table 2]

[0090] According to Table 2, Examples 1 to 6 exhibited a low dielectric constant (Dk) of 3.5 or less, a low dielectric loss (Df) of 0.015 or less, and a low coefficient of thermal expansion (CTE) of 40 ppm / °C or less, as well as a surface roughness of 100 nm to 300 nm. They also showed excellent copper foil adhesion and good high-temperature reliability. On the other hand, Comparative Example 1 was an insulating film using a composition that did not use styrene-maleic anhydride copolymer (SMA). While it showed low dielectric loss and a low coefficient of thermal expansion, high-temperature reliability evaluation revealed that numerous blisters occurred, and the copper foil adhesion decreased by more than 25% compared to the initial state, resulting in poor high-temperature reliability.

[0091] Furthermore, in the case of Comparative Example 2, the silica particle size was higher than the upper limit of the present invention, and it exhibited low dielectric loss, a low coefficient of thermal expansion, and good adhesion to copper foil. However, the surface roughness after desmearing was 892 nm, which is very high compared to Examples 1-6, making it difficult to apply to fine pattern applications.

[0092] Comparative Example 3 had an average silica particle size lower than the lower limit of the present invention. As a result, the dielectric loss exceeded 0.015, the thermal expansion coefficient exceeded 40 ppm / °C, and the appearance and copper foil adhesion in the high-temperature reliability evaluation were poor.

[0093] Comparative Example 4 did not use a cyanate ester resin as the curing agent, and as a result, its coefficient of thermal expansion was the highest, exceeding 40 ppm / °C, and its copper foil adhesion in the high-temperature reliability evaluation was poor.

[0094] Comparative Example 5, which did not use a phenolic resin, had the lowest dielectric loss (Df) and thermal expansion coefficient, but exhibited poor copper foil adhesion in high-temperature reliability evaluation.

Claims

1. The material comprises a curable resin, a curing agent, a styrene-maleic anhydride copolymer (SMA), and an inorganic filler. The curable resin includes an epoxy resin, The curing agent comprises a cyanate ester resin and a phenol resin. The inorganic filler is a thermosetting resin composition containing silica having an average particle size of 0.1 μm or more and less than 0.2 μm.

2. The thermosetting resin composition according to claim 1, wherein the styrene-maleic anhydride copolymer contains 10% to 40% maleic anhydride.

3. The thermosetting resin composition according to claim 1, wherein the content of the styrene-maleic anhydride copolymer is 5 parts by weight or more and less than 40 parts by weight per 100 parts by weight of the cyanate ester resin.

4. The thermosetting resin composition according to claim 1, wherein the weight ratio of the cyanate ester resin to the phenol resin is 95:5 to 40:

60.

5. The thermosetting resin composition according to claim 1, wherein the weight ratio of the epoxy resin to the cyanate ester resin is 60:40 to 20:

80.

6. It also contains additives, The thermosetting resin composition according to claim 1, wherein the additive is selected from the group consisting of a curing accelerator, a leveling agent, a wetting agent, an antistatic agent, a thermoplastic polymer resin, and an antioxidant.

7. An insulating film comprising the thermosetting resin composition according to any one of claims 1 to 6.

8. The insulating film according to claim 7, wherein the insulating film in a cured state under the condition of 10 GHz has a CTE (coefficient of thermal expansion) value of 45 ppm / °C or less.

9. An insulating film in a cured state under 10 GHz conditions, Having a Dk (dielectric constant) value of 3.5 or less, The insulating film according to claim 7, having a Df (dielectric loss tangent) value of 0.015 or less.

10. The insulating film according to claim 7, wherein the difference in copper foil adhesion force satisfies the following formula 1: A2 / A1>0.75 (Formula 1) In the above formula 1, A1 is the initial copper foil adhesion strength (gf / cm) measured after copper plating on at least one side of the insulating film, and A2 is the later copper foil adhesion strength (gf / cm) measured after the insulating film has undergone a Hot Air Reflow Test (performed 10 times at a maximum temperature of 260°C).

11. A printed circuit board comprising the insulating film described in claim 7.

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