Thermosetting resin composition, and insulating film and printed circuit board comprising same

Abstract

The present specification relates to a thermosetting resin composition, and an insulating film and a printed circuit board comprising same, the 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 diameter of 0.1 μm inclusive to 0.2 μm exclusive as an inorganic filler. The thermosetting resin composition according to the embodiment can ensure excellent curing properties and superb high-temperature reliability.

Description

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

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

[0002] This application claims the benefit of the filing dates of Korean Patent Application No. 10-2023-0171426 and Korean Patent Application No. 10-2024-0143082, filed with the Korean Intellectual Property Office on November 30, 2023 and October 18, 2024, respectively, the entire contents of which are incorporated herein by reference.

[0003] A printed circuit board (PCB) is a support for electronic components. It is a board that fixes electronic components to the surface of the printed wiring board and connects the components with copper wires to form an electronic circuit.

[0004] Typically, printed circuit boards are based on multilayer construction, with copper interconnects insulated. To enhance board reliability, methods have been proposed to enhance the adhesion between the insulating layer and the copper foil layer. These include incorporating a component with high bonding affinity for copper into the insulating layer, or roughening the insulating layer's 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 used, laminated on an inner circuit board on which a copper foil circuit is formed, and interlayer connection is made by through-hole. However, this method requires large-scale equipment, is costly and time-consuming, and has the problem that it is difficult to form a fine pattern.

[0006] As a way to solve the above problem, a multilayer printed circuit board manufacturing method incorporating a build-up method has recently been proposed. This is a technology that alternately laminates organic insulating layers (or insulating films) on the conductive layers of a circuit board.

[0007] In general, the manufacturing process of a multilayer printed circuit board using a build-up method proceeds in the following order: a step of vacuum laminating a build-up insulating film on an inner layer circuit; a precure step; a drilling step; a desmear step; an electroless plating step; an electroplating step; a postcure step; and an outer layer circuit formation step.

[0008] The above desmear step is an essential process that removes smear (residue derived from resin components contained in the insulating film) from the insulating film using an acidic solution. This chemical treatment erodes a portion of the insulating film surface to create a certain level of roughness. This roughness, thus formed on the insulating film surface, serves to enhance adhesion to the copper layer in the future.

[0009] As for the resin composition for the above build-up insulating film, a composition in which silica particles were filled as an inorganic filler in epoxy resin and a phenolic hardener was used in the initial product, but as the demand for low dielectric properties and low CTE increases, there is a trend toward developing products that use cyanate ester hardeners in epoxy resin.

[0010] However, although the cured product of epoxy resin and cyanate ester resin has advantages such as low CTE and low Df, it is easily hydrolyzed by residual moisture at high temperatures, which may cause problems such as gas generation, blister formation, and deterioration of mechanical properties, resulting in a decrease in durability and / or reliability in a high temperature environment.

[0011] Using large-sized inorganic fillers facilitates control of the surface roughness formed during the desmear step, which improves adhesion to the copper layer. However, there is a problem that it is difficult to process micro-sized via holes due to the detachment of inorganic filler particles during laser drilling. To improve this, if an inorganic filler with a small particle size of 0.1 ㎛ to less than 0.2 ㎛ is used, the surface roughness formed after the desmear step is too low, which reduces the interlocking effect at the interface with the copper layer, and as a result, the above-mentioned reliability problem can occur more fatally.

[0012] Accordingly, there is a need to develop materials that secure advantages such as low CTE and low Df while improving durability and / or reliability in high-temperature environments.

[0013] The present specification relates to a thermosetting resin composition for solving the above problem, an insulating film comprising the same, and a printed circuit board.

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

[0015] Accordingly, in order to solve the existing problems, the implementation status of this specification is as follows.

[0016] One embodiment of the present specification provides a thermosetting resin composition comprising a curable resin, a curing agent, a copolymer of styrene-maleic anhydride (SMA), and an inorganic filler, wherein the curable resin comprises an epoxy resin and a phenol resin, the curing agent comprises a cyanate ester resin, and the inorganic filler comprises silica having an average particle diameter of 0.1 μm or more and less than 0.2 μm.

[0017] Another embodiment of the present specification provides an insulating film comprising the thermosetting resin composition described above and a cured product thereof.

[0018] Another embodiment of the present disclosure provides a printed circuit board including the insulating film described above.

[0019] The thermosetting resin composition according to the present specification 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), so that warpage can be reduced when an insulating film using the composition is used in a printed circuit board in the future.

[0020] In addition, the thermosetting resin composition according to the present specification has excellent durability at high temperatures (about 200°C or higher), and thus can improve reliability when an insulating film using the composition is used in a printed circuit board in the future.

[0021] In addition, the thermosetting resin composition according to the present specification has excellent copper foil adhesion, and thus can provide the advantage of not causing defects such as blisters when an insulating film using the composition is used in a printed circuit board in the future.

[0022] Hereinafter, the present specification will be described in more detail.

[0023] <Thermosetting resin composition>

[0024] Below is a description of a thermosetting resin composition according to one embodiment of the present specification.

[0025] A thermosetting resin composition according to one embodiment of the present specification is characterized in that it includes an epoxy resin as a curable resin, a cyanate ester resin and a phenol resin as a curing agent, and silica having an average particle size of 0.1 ㎛ or more and less than 0.2 ㎛ as an inorganic filler, as described above.

[0026] In the case of the composition as described above, it is possible to simultaneously have excellent curing properties (low coefficient of thermal expansion, low dielectric constant and high glass transition temperature) and excellent high-temperature durability and reliability.

[0027] According to another embodiment of the present 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, and may be 0.1 μm or more.

[0028] When the average particle size of silica is within the above range, a certain level of surface roughness can be formed even after desmear, which is required for recent fine-pattern printed circuit boards. If silica with an average particle size of at least 0.2 ㎛ or more is used, the surface roughness may be formed too high by desmear, and it may be difficult to process a via hole of the desired size due to the detachment of large silica particles during laser drilling. In addition, if silica with an average particle size of at least less than 0.1 ㎛ is used, the surface roughness may be formed too low by desmear, the dielectric loss may increase, or the copper foil adhesion may deteriorate. Furthermore, if silica with an average particle size of 0.01 ㎛ or less is used, the film processing itself may be difficult due to the problem of increased solution viscosity.

[0029] In the present specification, the epoxy resin is not particularly limited to those known in the art, but examples thereof 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., and one type of the epoxy resin of the type exemplified above may be used alone or two or more types may be mixed and used.

[0030] In the present specification, the cyanate ester resin is not particularly limited to those known in the art, but may include novolak type, dicyclopentadiene type, bisphenol type (bisphenol A type, bisphenol F type, bisphenol S type, etc.), prepolymers in which some of the cyanate ester resins of the types exemplified above are converted to triazine, etc., and one type of the cyanate ester resin of the types exemplified above may be used alone or two or more types may be mixed and used.

[0031] In the present specification, the copolymer of styrene-maleic anhydride (SMA) is not particularly limited to those known in the art, but examples thereof include NST-438, SMAEF30, SMAEF40, SMAEF60, SMAEF 80, SMA1000, SMA2000, etc., and one of the above-mentioned SMAs may be used alone or two or more may be mixed and used.

[0032] According to one embodiment of the present specification, the styrene-maleic anhydride copolymer may include 10% or more and 40% or less of maleic anhydride (relative to the entire styrene-maleic anhydride copolymer).

[0033] If the content of maleic anhydride in the above styrene-maleic anhydride copolymer is less than 10%, the effect of improving high-temperature durability by addition may be minimal, and if it exceeds 40%, the mechanical properties of the final cured product may deteriorate.

[0034] According to one embodiment of the present specification, the content of the copolymer of styrene-maleic anhydride may be 5 parts by weight or more and less than 40 parts by weight based on 100 parts by weight of the cyanate ester resin.

[0035] If the content of the above styrene-maleic anhydride copolymer is less than 5 parts by weight relative to 100 parts by weight of the cyanate ester resin, the effect of improving high-temperature durability may be minimal, and if it exceeds 40 parts by weight, the mechanical properties of the final cured product may deteriorate.

[0036] According to one embodiment of the present specification, the curing agent further includes a phenol resin, and the weight ratio between the cyanate ester resin and the phenol resin may be 95:5 to 40:60. Preferably, the weight ratio between the cyanate ester resin and the phenol resin may be 90:10 to 60:40, or 85:25 to 70:30.

[0037] When a phenol resin is mixed with a cyanate ester resin corresponding to a curing agent in the weight ratio range mentioned above, the curing speed of the cyanate ester resin is accelerated, and a cured product having various mechanical properties can be obtained depending on the type and content of the phenol resin used. In addition, as described above in the preferred range, when the content of the phenol resin is less than the content of the cyanate ester resin, fewer hydrophilic OH groups can be formed after curing with the epoxy, so that the target Low Df characteristics can be more easily achieved.

[0038] According to one embodiment of the present specification, the phenolic resin may include a compound including a phenol skeleton, a naphthol skeleton, or a novolak skeleton.

[0039] According to one embodiment of the present specification, the phenol resin may be a compound including a novolac skeleton.

[0040] When the above phenol resin includes the above-described skeleton, heat resistance, water resistance, etc. can be improved.

[0041] According to one embodiment of the present specification, the weight ratio between the epoxy resin and the cyanate ester resin may be 60:40 to 20:80.

[0042] When the weight ratio of epoxy resin and cyanate ester resin falls within the above range, no unreacted epoxy resin remains after curing, which can be expected to further improve dielectric properties and mechanical properties, and further contribute to improved high-temperature durability. Furthermore, the excessive self-crosslinking reaction of the cyanate ester resin is controlled, which can prevent brittle fracture, which easily causes the film to break after curing.

[0043] According to one embodiment of the present specification, the thermosetting resin composition further comprises an additive, and the additive may be 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.

[0044] In this specification, the curing accelerator is a substance for promoting the curing reaction of a thermosetting resin composition together with a curing agent, and is not particularly limited to those known in the art, but examples thereof include imidazole compounds, amine compounds, organic phosphine compounds, metal compounds, etc., and one of the curing accelerators exemplified above may be used alone or two or more may be mixed and used.

[0045] The above 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-undecylimidazolium trimellitate, 1-Cyanoethyl-2-phenylimidazolium 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-triazineisocyanuric acid adduct, 2-phenylimidazoleisocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, Examples include 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline, and 2-phenylimidazoline.

[0046] Examples of the above amine compounds include triethylamine, tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, 1,8-diazabicyclo(5,4,0)-undecene, etc.

[0047] Examples of the above metal compounds include organometallic complexes or organometallic salts of metals such as cobalt, copper, zinc, iron, nickel, manganese, and tin. Specific examples of the above organometallic complexes include cobalt(II) acetylacetonate, cobalt(III) acetylacetonate, copper(II) acetylacetonate, zinc(II) acetylacetonate, iron(III) acetylacetonate, nickel(II) acetylacetonate, manganese(II) acetylacetonate, and the like. In addition, examples of the above organometallic salts include zinc octylate, tin octylate, zinc naphthenate, cobalt naphthenate, tin stearate, and zinc stearate.

[0048] In addition, when the non-volatile content in the thermosetting resin composition is assumed to be 100 mass%, the curing accelerator can be used within the range of 0.01% to 5%.

[0049] In this specification, the leveling agent and wetting agent are substances that improve coating processability and coating appearance by controlling the surface tension, flowability, spreadability, etc. of the curable resin composition, and are not particularly limited to those known in the art.

[0050] In this specification, the antistatic agent is a substance that provides an antistatic effect, and is not particularly limited to those known in the art. In some cases, one type or a mixture of two or more types of antistatic agents may be used.

[0051] In the present 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 to those known in the art, but examples thereof include phenoxy resin, polyvinyl acetal resin, polyvinyl butyral resin, polyimide resin, polyamideimide resin, polyetherimide resin, polysulfone resin, polyethersulfone resin, polyphenylene ether resin, polycarbonate resin, polyetheretherketone resin, and polyester resin. In some cases, the thermoplastic polymer resin may be used alone or in a mixture of two or more. It is preferable that the thermoplastic resin include a phenoxy resin. The weight average molecular weight of the thermoplastic resin may be from 5,000 g / mol to 200,000 g / mol, but is not limited thereto.

[0052] In this specification, the antioxidant is a material known in the art that enhances thermal stability, and is not particularly limited thereto. In some cases, one or more antioxidants may be used in combination.

[0053] In one embodiment according to the present specification, the thermosetting resin composition may include a solvent.

[0054] In the present specification, when the thermosetting resin composition includes a solvent, the solvent may be applied without particular limitation as long as it is known in the technical field to which the present invention pertains to enable the formation of a thermosetting resin composition. As a non-limiting example, the solvent may be one or more compounds selected from the group consisting of esters, ethers, ketones, aromatic hydrocarbons, and sulfoxides.

[0055] The above ester solvents are 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, gamma-butyrolactone, epsilon-caprolactone, delta-valerolactone, alkyl oxyacetic acids (e.g., methyl oxyacetic acid, ethyl oxyacetic acid, butyl oxyacetic acid (e.g., methyl methoxyacetic acid, ethyl methoxyacetic acid, butyl methoxyacetic acid, methyl ethoxyacetic acid, ethyl ethoxyacetic acid, etc.)), alkyl 3-oxypropionic acid esters (e.g., methyl 3-oxypropionate, ethyl 3-oxypropionate, etc. (e.g., 3-methoxypropionate methyl, 3-methoxypropionate ethyl, 3-ethoxypropionate methyl, 3-ethoxypropionate ethyl, etc.), 2-oxypropionic acid alkyl esters (e.g., 2-oxypropionate methyl, 2-oxypropionate ethyl, 2-oxypropionate propyl, etc. (e.g., 2-methoxypropionate methyl, 2-methoxypropionate ethyl, 2-methoxypropionate propyl, 2-ethoxypropionate methyl, 2-ethoxypropionate ethyl)), 2-oxy-2-methylpropionate methyl and 2-oxy-2-methylpropionate ethyl (e.g., 2-methoxy-2-methylpropionate methyl, 2-ethoxy-2-methylpropionate ethyl, etc.), methyl pyruvate, It can be ethyl pyruvate, propyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl 2-oxobutanoate, ethyl 2-oxobutanoate, etc.

[0056] The above 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.

[0057] The above ketone solvent may be methyl ethyl ketone (MEK), cyclohexanone, cyclopentanone, 2-heptanone, 3-heptanone, N-methyl-2-pyrrolidone, etc.

[0058] The above aromatic hydrocarbon solvent may be toluene, xylene, anisole, limonene, etc.

[0059] The above sulfoxide solvent may be dimethyl sulfoxide, etc.

[0060] Insulating film

[0061] Below is a description of an insulating film according to one embodiment of the present specification.

[0062] One embodiment of the present specification provides an insulating film, specifically a build-up insulating film, comprising the thermosetting resin composition described above.

[0063] The insulating film according to this specification can be processed in the following order: vacuum lamination, precure, drilling, desmear, electroless plating, electroplating, postcure, and outer layer circuit formation to manufacture a printed circuit board.

[0064] In the present specification, the insulating film may have the following curing properties through thermal curing (e.g., thermal curing at a temperature of 190°C to 200°C for a time of 90 minutes or more).

[0065] In one embodiment of the present specification, the cured insulating film under conditions of 10 GHz can have a CTE (coefficient of thermal expansion) value of 45 ppm / ℃ or less.

[0066] In another embodiment of the present specification, the coefficient of thermal expansion (for the insulating film) measured in the cured state may be 40 ppm / ℃ or less, 35 ppm / ℃ or less, or 30 ppm / ℃ or less, and 15 ppm / ℃ or more.

[0067] When the thermal expansion coefficient within the above range is satisfied, the difference in thermal expansion coefficient with the copper foil is small, so there is an advantage in that the amount of warpage that occurs after lamination with the copper foil layer is small.

[0068] Specifically, the coefficient of thermal expansion can be measured in a temperature range of 25°C to 120°C using a thermomechanical analyzer (TMA) after the insulating film is heat-cured at a temperature of 190°C for 90 minutes.

[0069] In one embodiment of the present specification, the cured insulating film 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.

[0070] In another embodiment of the present specification, the Dk value of the insulating film measured in a cured state may be 3.4 or less, 3.3 or less, or 3.2 or less, and 2.4 or more.

[0071] In another embodiment of the present specification, the Df value of the insulating film may be 0.0145 or less, or 0.014 or less, and 0 or greater.

[0072] When the dielectric constant and dielectric loss tangent of the above range are satisfied, it is advantageous to respond to fine wiring and high-speed transmission for high integration and high density of semiconductor chips.

[0073] According to one embodiment of the present specification, the difference in adhesion between the copper foil of the insulating film can satisfy the following equation 1.

[0074] A2 / A1 > 0.75 - Equation 1

[0075] In the above equation 1,

[0076] A1 is the initial copper foil adhesion (gf / cm) measured after copper plating on at least one side of the insulating film, and A2 is the later copper foil adhesion (gf / cm) measured after the insulating film was subjected to a Hot Air Reflow Test (performed 10 times at a maximum temperature of 260°C).

[0077] If the above range is satisfied, the high temperature durability of the insulating film can be evaluated as high.

[0078] In one embodiment of the present specification, the average value of the arithmetic mean roughness (Ra) measured using an Optical Profiler (Nanoview 3D surface profiler NV-2700, Nanosystem) of the surface of the desmear-treated insulating film may be 80 nm or more, 100 nm or more, or 120 nm or more, and 500 nm or less, 400 nm or less, or 300 nm or less.

[0079] If the surface roughness of the insulating film after desmear treatment is less than 80 nm, the interlocking effect at the interface with the copper foil is reduced, and additional reliability problems may occur. If the surface roughness formed after desmear treatment exceeds 500 nm, the adhesion to the copper foil is excellent, but when flash etching is performed after electroplating, the plating removal time is long and the wiring shape becomes thinner. In addition, there is difficulty in applying the fine line width of less than 10 ㎛, which is recently required.

[0080] Printed circuit board

[0081] Below is a description of a printed circuit board according to one embodiment of the present specification. Since the printed circuit board includes an insulating film formed from the thermosetting resin composition described above, the contents regarding the thermosetting resin composition described above may be applied.

[0082] Hereinafter, examples will be provided to specifically explain this specification. However, the embodiments described herein may be modified in various ways, and the scope of this specification is not limited to the embodiments described below. The embodiments described herein are provided to more fully explain this specification to those of average skill in the art.

[0083] <Example>

[0084] Example 1: Preparation of thermosetting resin composition 1

[0085] As a curable epoxy resin, 70 parts by weight of a bisphenol-based epoxy resin (YD-128, Kukdo Chemical) and 30 parts by weight of a phenol novolac-type epoxy resin (YDPN-639, Kukdo Chemical), as a cyanate ester-based resin as a curing agent, 112 parts by weight of a dicyclopentadiene bisphenol-based cyanate ester resin (MEK solution with 75% nonvolatile content, C03CS, TECHIA), 24 parts by weight of a biphenyl-based phenol resin (GPH-65, Nippon Explosives), 14 parts by weight of a styrene-maleic anhydride copolymer (MEK solution with 60% nonvolatile content, NST-438, Nanoco), and 385 parts by weight of a silica slurry (MEK solution with 60% nonvolatile content, K180SX-CM3, ADMATECHS) having an average particle size of 0.18㎛ as an inorganic filler. After mixing 15 parts by weight of phenoxy resin (YP-50, Kukdo Chemical) as an additive (thermoplastic polymer resin) and 126 parts by weight of MEK (methyl ethyl ketone) as a solvent, the mixture was stirred at 250 rpm for 3 hours using a mechanical stirrer.

[0086] After that, 1.0 part by weight of an imidazole-based curing accelerator (2PHZ-PW, Shikoku Chemicals) and 0.05 part by weight of an inorganic metal-based curing accelerator, Cobalt(II) acetylacetonate (TCI), were added and uniformly dispersed using a high-speed rotary mixer to prepare a thermosetting resin composition 1.

[0087] Examples 2 to 5: Preparation of thermosetting resin compositions 2 to 5

[0088] When preparing a thermosetting resin composition, thermosetting resin compositions 2 to 5 were 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 the curable resin (epoxy resin)) were changed as shown in Table 1 below.

[0089] Example 6: Preparation of thermosetting resin composition 6

[0090] When preparing a thermosetting resin composition, a thermosetting resin composition 6 was prepared in the same manner as Example 1, except that the type and content of each component (based on 100 parts by weight of the curable resin (epoxy resin)) and 385 parts by weight of silica slurry (MEK solution with 60% nonvolatile content, SC2050-MB, ADMATECHS) having an average particle size of 0.1 ㎛ as an inorganic filler were changed as shown in Table 1 below.

[0091] Comparative Example 1: Preparation of thermosetting resin composition A

[0092] A thermosetting resin composition A was prepared in the same manner as in Example 1, except that the styrene-maleic anhydride resin was not added and the content of phenoxy resin (YP-50, Kukdo Chemical) was changed to 23 parts by weight as shown in Table 1 below.

[0093] Comparative Example 2: Preparation of thermosetting resin composition B

[0094] A thermosetting resin composition B was prepared in the same manner as in Example 1, except that 330 parts by weight of silica slurry (MEK solution with 70% nonvolatile content, SC2050-MB, ADMATECHS) with an average particle size of 0.5 ㎛ as an inorganic filler and 181 parts by weight of MEK (methyl ethyl ketone) as a solvent were used, as shown in Table 1 below.

[0095] Comparative Example 3: Preparation of thermosetting resin composition C

[0096] A thermosetting resin composition C was prepared in the same manner as in Example 1, except that 462 parts by weight of silica slurry (MEK solution with 50% nonvolatile content, Y50SZ-AM1, ADMATECHS) with an average particle size of 0.05 ㎛ as an inorganic filler and 49 parts by weight of MEK (methyl ethyl ketone) as a solvent were changed as shown in Table 1 below.

[0097] Comparative Example 4: Preparation of thermosetting resin composition D

[0098] A thermosetting resin composition D was prepared in the same manner as in Example 1, except that the content of phenol resin (GPH-65, Japanese gunpowder) was changed to 108 parts by weight without adding cyanate ester resin and 154 parts by weight of MEK (methyl ethyl ketone) as a solvent, as shown in Table 1 below.

[0099] Comparative Example 5: Preparation of thermosetting resin composition E

[0100] A thermosetting resin composition E was prepared in the same manner as in Example 1, except that the content of cyanate ester resin (MEK solution with 75% nonvolatile content, C03CS, TECHIA) was changed to 144 parts by weight without adding phenol resin and 118 parts by weight of MEK (methyl ethyl ketone) as a solvent, as shown in Table 1 below.

[0101]

[0102] Styrene-maleic anhydride copolymer NST-414 (MEK solution with 60% nonvolatile content, 19 wt% maleic anhydride content, Nanoco)

[0103] Styrene-maleic anhydride copolymer NST-438 (MEK solution with 60% nonvolatile content, 11% by weight maleic anhydride content, Nanoco)

[0104] <Experimental Example>

[0105] 1. Sample production: Manufacturing of insulating film

[0106] The thermosetting resin compositions manufactured in Examples 1 to 6 and Comparative Examples 1 to 5 were used as a coating solution, and coated on a support film (PET film) having a thickness of 38 μm using an applicator, and then dried at 100°C for 8 minutes to manufacture insulating film samples having a thickness of 25 μm, respectively.

[0107] 2. Experimental Example 1: Measurement of dielectric constant (Dk and Df)

[0108] After each of the above insulating film samples was heat-cured at 190°C for 90 minutes, 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.

[0109] 3. Experimental Example 2: Measurement of Coefficient of Thermal Expansion (CTE)

[0110] Each of the above insulating film samples was heat-cured at 190°C for 90 minutes, and then the thermal expansion coefficient was measured in the range of 25°C to 120°C at a heating rate of 10°C / min using TMA (TA TMA Q400). The measurement results are shown in Table 2 below.

[0111] 4. Experimental Examples 3 and 4: High-Temperature Reliability Evaluation

[0112] 1) Desmear treatment

[0113] The above insulating film samples were laminated by pressing them on a CCL (copper clad laminate) substrate using a vacuum pressurized laminator at a temperature of 100°C and a pressure of 0.7 MPa for 30 seconds, and then pre-cured in a hot air oven at 100°C for 30 minutes and then at 170°C for 30 minutes.

[0114] Next, the supporting film (PET film) of the insulator was peeled off to expose the insulating layer, and then desmear treatment was performed. Desmear treatment was performed in the following order: swelling solution treatment (60°C, 5 minutes), oxidation solution treatment (80°C, 20 minutes), and neutralizing solution treatment (50°C, 4 minutes) using Atotech's Securiganth MV series treatment solution.

[0115] 2) Surface roughness (Ra, nm) measurement (Experimental Example 3)

[0116] The surface of the desmear-treated 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 as the average value.

[0117] 3) Copper plating treatment

[0118] Copper plating was performed in two stages: electroless chemical copper plating and electrolytic copper plating. Electroless chemical copper plating was performed using Atotech's Printoganth MV product to a plating thickness of 1.0 ㎛, and after treatment, it was dried in a hot air oven at 150°C for 30 minutes.

[0119] Electroplating was performed using Atotech's Expt Inpro SAP6 chemical to a plating thickness of approximately 20 ㎛, and after treatment, heat treatment was performed in a hot air oven set to 190°C for 1 hour.

[0120] 4) High temperature reliability evaluation

[0121] High-temperature reliability of copper-plated samples was evaluated using a Hot Air Reflow Test Machine (SEF). 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 single pass time of 5 minutes. After 10 passes per sample, the appearance and copper foil adhesion were checked to determine high-temperature reliability.

[0122] 5) High-temperature reliability assessment (Experimental example 4)

[0123] The 90-degree peel strength of the copper plating layer was measured using a Stable Micro Systems Texture Analyzer (TA-XT Plus). The high-temperature reliability was determined by the difference between the initial copper plating adhesion (A1 = adhesion measured after copper plating) and the later copper plating adhesion (A2) described in the high-temperature reliability evaluation above.

[0124] The copper foil adhesion was determined to be poor if the copper foil adhesion was reduced by 25% or more after the high-temperature reliability evaluation by measuring before and after the high-temperature reliability evaluation. In other words, if the following equation was not satisfied, the copper foil adhesion was determined to be poor.

[0125] A2 / A1 > 0.75 - Equation 1

[0126] In the above equation 1,

[0127] A1 is the initial copper foil adhesion (gf / cm) measured after copper plating on at least one side of the insulating film,

[0128] A2 is the later copper foil adhesion (gf / cm) measured after passing the insulating film 10 times through a Hot Air Reflow Test Machine (SEF) under the conditions of a maximum temperature of 260℃, a line speed of 20 cm / min, a line length of 100 cm, and a single pass time of 5 minutes.

[0129] Additionally, if the initial copper foil adhesion was less than 400 gf / cm, it was judged as defective and a high-temperature reliability evaluation was not performed.

[0130] In addition, after the high-temperature reliability evaluation, the appearance was checked, and if any appearance defects such as blistering or copper foil lifting occurred, the high-temperature reliability was judged to be poor. The judgment results are as shown in Table 2 below.

[0131] Types of thermosetting resin compositions used in insulating films Experimental example 1 Experimental example 2 Experimental example 3 Experimental example 4 DkDfCTE Surface roughness (nm) Appearance Copper foil adhesion Example 13.10.01237264 Good Good Example 23.10.01136242 Good Good Example 33.10.01440166 Good Good Example 43.10.01137247 Good Good Example 53.10.01035239 Good Good Example 63.20.01439162 Good Good Comparative example 13.20.01238280 Poor Poor Comparative example 23.10.01135892 Good Good Comparative example 33.20.01644111DefectiveDefectiveComparison Example 43.20.01952153GoodDefectiveComparison Example 53.10.00934121GoodDefective

[0132] According to Table 2 above, 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 / ℃ or less, and a surface roughness of 100 nm to 300 nm, 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 a styrene-maleic anhydride copolymer (SMA), and exhibited low dielectric loss and low coefficient of thermal expansion, but the high-temperature reliability evaluation results showed that many blisters occurred and the copper foil adhesion decreased by more than 25% compared to the initial level, resulting in poor high-temperature reliability.

[0133] In addition, in the case of Comparative Example 2, the particle size of silica was higher than the upper limit of the present invention, so that low dielectric loss, low coefficient of thermal expansion, and good adhesion to copper foil were achieved, but the surface roughness after desmearing was 892 nm, which was very high compared to Examples 1 to 6, and thus it is difficult to apply it for fine pattern purposes.

[0134] Comparative Example 3 had an average particle size of silica lower than the lower limit of the present invention, resulting in a dielectric loss exceeding 0.015, a coefficient of thermal expansion exceeding 40 ppm / ℃, and poor appearance and copper foil adhesion in a high-temperature reliability evaluation.

[0135] Comparative Example 4 did not use cyanate ester resin in the hardener, and as a result, the thermal expansion coefficient was the highest at over 40 ppm / ℃, and the copper foil adhesion was poor in the high-temperature reliability evaluation.

[0136] Comparative Example 5 was a composition that did not use phenolic resin and had the lowest dielectric loss (Df) and coefficient of thermal expansion, but the copper foil adhesion was poor in the high-temperature reliability evaluation.

Claims

1. Containing a curable resin, a curing agent, a copolymer of styrene-maleic anhydride (SMA) and an inorganic filler, The above curable resin includes epoxy resin, The above curing agent includes cyanate ester resin and phenol resin, A thermosetting resin composition wherein the above-mentioned inorganic filler comprises silica having an average particle diameter of 0.1 ㎛ or more and less than 0.2 ㎛.

2. In claim 1, A thermosetting resin composition wherein the above styrene-maleic anhydride copolymer contains 10% or more and 40% or less of maleic anhydride.

3. In claim 1, A thermosetting resin composition wherein the content of the copolymer of the above styrene-maleic anhydride is 5 parts by weight or more and less than 40 parts by weight based on 100 parts by weight of the above cyanate ester resin.

4. In claim 1, A thermosetting resin composition wherein the weight ratio between the cyanate ester resin and the phenol resin is 95:5 to 40:

60.

5. In claim 1, A thermosetting resin composition wherein the weight ratio between the epoxy resin and the cyanate ester resin is 60:40 to 20:

80.

6. In claim 1, Contains additional additives, A thermosetting resin composition 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 a thermosetting resin composition according to any one of claims 1 to 6.

8. In claim 7, An insulating film, wherein the insulating film in a cured state under conditions of 10 GHz has a CTE (coefficient of thermal expansion) value of 45 ppm / ℃ or less.

9. In claim 7, The insulating film in the cured state under 10 GHz conditions Have a Dk (dielectric constant) value of 3.5 or less, An insulating film having a Df (dissipation factor) value of 0.015 or less.

10. In claim 7, An insulating film having a difference in adhesion between copper foils satisfying the following equation 1: A2 / A1 > 0.75 - Equation 1 In the above equation 1, A1 is the initial copper foil adhesion (gf / cm) measured after copper plating on at least one side of the insulating film, and A2 is the later copper foil adhesion (gf / cm) measured after the insulating film is subjected to a Hot Air Reflow Test (performed 10 times at a maximum temperature of 260°C).

11. A printed circuit board comprising an insulating film according to claim 7.

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