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

Abstract

The present specification relates to a curable resin composition comprising: an epoxy resin; a phenol-based curing agent; and an inorganic filler, wherein the phenol-based curing agent includes a mixture of a phenol resin containing a naphthol aralkyl skeleton and a phenol resin containing a triazine skeleton, and the amine group content is at least 15 wt% with respect to the total amount of the phenol resin containing a triazine skeleton. The curable resin composition according to said embodiment maintains high peel strength while having a low coefficient of thermal expansion, and thus can prevent cracking during reliability testing when later used as an insulating film.

Description

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

[0001] The present specification relates to a curable 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. 10-2024-0030473, filed with the Korean Intellectual Property Office on March 4, 2024, and Korean Patent Application No. 10-2025-0027402, filed with the Korean Intellectual Property Office on March 4, 2025, 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 creating a uniform roughness on 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 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 method for solving the above problem, a method for manufacturing a multilayer printed circuit board using a build-up method has recently been proposed. The build-up method is a technology for alternately laminating organic insulating layers (or insulating films) on the conductive layers of a circuit board.

[0007] However, the significant difference in coefficient of thermal expansion between the insulating layer and the copper wiring that make up the printed circuit board (PCB) can lead to cracking in the insulating layer and / or copper wiring during reliability tests such as thermal cycling. Consequently, research is being conducted to reduce the coefficient of thermal expansion of the resin composition that makes up the insulating layer.

[0008] Recently, a method of adding inorganic fillers has been mentioned to lower the thermal expansion coefficient of a resin composition. However, as the amount of inorganic fillers added increases, it becomes difficult to control the viscosity of the resin composition, and the exposure of the surface of the inorganic filler after the harmonizing treatment causes problems such as a decrease in peel strength for the conductive layer.

[0009] Therefore, further research on resin compositions is needed.

[0010] The present specification relates to a curable resin composition for solving the above problem, an insulating film comprising the same, and a printed circuit board.

[0011] The inventors of the present invention have discovered that when two phenol resins having different skeletons are introduced as a phenolic curing agent into a curable resin composition, when used as a material for an insulating film in the future, the composition exhibits properties such as a low coefficient of thermal expansion and improved peel strength through the introduction of a rigid structure.

[0012] Therefore, the implementation state based on the above characteristics is provided as follows.

[0013] One embodiment of the present specification provides a curable resin composition comprising an epoxy resin, a phenolic curing agent, and an inorganic filler, wherein the phenolic curing agent comprises a mixture of a naphthol aralkyl skeleton-containing phenol resin and a triazine skeleton-containing phenol resin, and the curable resin composition has an amine group content of 15 wt% or more based on the entire triazine skeleton-containing phenol resin.

[0014] Another embodiment of the present specification provides an insulating film comprising the above-described curable resin composition or a cured product thereof.

[0015] Another embodiment of the present disclosure provides a printed circuit board including the insulating film described above.

[0016] The curable resin composition according to the present specification has a low coefficient of thermal expansion, which can prevent cracking in future reliability tests of insulating films.

[0017] The curable resin composition according to the present specification can provide excellent copper foil adhesion by having high peel strength in terms of an insulating film in the future.

[0018] In particular, the curable resin composition according to the present specification can provide an advantage of preventing a decrease in peel strength under conditions of a high content of inorganic filler.

[0019] Hereinafter, the present specification will be described in more detail.

[0020] In this specification, when it is said that a member is located “on” another member, this includes not only cases where the member is in contact with the other member, but also cases where another member exists between the two members.

[0021] In this specification, when a part is said to “include” a certain component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise specifically stated.

[0022] As used herein, “polymer” means a compound composed of repeating units (basic units). The polymer may be represented as a polymer or a compound composed of a polymer, and the polymer may have one or more repeating units.

[0023] <Curable resin composition>

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

[0025] A curable resin composition according to one embodiment of the present specification includes a phenolic curing agent, wherein the phenolic curing agent includes a mixture of a naphthol aralkyl skeleton-containing phenol resin and a triazine skeleton-containing phenol resin, and is characterized in that the amine group content is 15 wt% or more based on the entire triazine skeleton-containing phenol resin.

[0026] As described above, by using a phenolic curing agent containing two different phenolic resins and ensuring that the content of amine groups of the phenolic resin containing a double triazine skeleton satisfies the lower limit, high peel strength can be achieved under conditions of low thermal expansion coefficient.

[0027] According to one embodiment of the present specification, the amine group content may be 15 wt% or more, 16 wt% or more, 17 wt% or more, or 18 wt% or more, and 30 wt% or less, 29 wt% or less, 28 wt% or less, 27 wt% or less, or 26 wt%, based on the entire triazine skeleton-containing phenol resin.

[0028] According to one embodiment of the present specification, the epoxy resin may include a phenol novolac type epoxy resin.

[0029] In this specification, examples of the phenol novolac type epoxy resin include, but are not particularly limited to, YDPN-638 and YDPN-639 (Nippon-Tetsu Chemical).

[0030] According to one embodiment of the present specification, the phenol novolac type epoxy resin may be 40 wt% or more, 45 wt% or more, 50 wt% or more, 55 wt% or more, or 60 wt% or more, and 90 wt% or less, 85 wt% or less, 80 wt% or less, 75 wt% or less, 70 wt% or less, or 65 wt% or less, based on 100 wt% of the total epoxy resin.

[0031] When the content range of the phenol novolac type epoxy resin according to the above embodiment is satisfied, the surface roughness can more easily be achieved in the range of preferably 300 nm or more and 400 nm or less, which is easy in terms of forming a microcircuit.

[0032] According to one embodiment of the present specification, the composition ratio of the naphthol aralkyl skeleton-containing phenol resin and the triazine skeleton-containing phenol resin may be 1:10 to 10:1 by weight.

[0033] According to one embodiment of the present specification, the composition ratio of the naphthol aralkyl skeleton-containing phenol resin and the triazine skeleton-containing phenol resin may be 1:8 to 8:1, 1:6 to 6:1, or 1:4 to 4:1 by weight.

[0034] When two different phenol resins satisfy the above composition ratio, as described above, higher peel strength can be additionally achieved under conditions of low thermal expansion coefficient.

[0035] According to one embodiment of the present specification, a naphthol aralkyl skeleton-containing phenol resin can be represented by the following structural formula 1.

[0036] [Structural formula 1]

[0037]

[0038] In the above structural formula 1,

[0039] is a connection point with other structures,

[0040] X1 and X2 are the same or different from each other, and each independently represents a divalent organic group,

[0041] a and b are equal to or different from each other and are each independently an integer from 1 to 6,

[0042] n is an integer from 1 to 20.

[0043] According to one embodiment of the present specification, X1 and X2 may be the same as or different from each other, and may each independently be a substituted or unsubstituted alkylene group; a substituted or unsubstituted arylene group; or a substituted or unsubstituted divalent amine group.

[0044] According to one embodiment of the present specification, X1 and X2 may be the same as or different from each other, and may each independently be a substituted or unsubstituted C1 to C30 alkylene group; a substituted or unsubstituted C6 to C30 arylene group; or a substituted or unsubstituted divalent amine group.

[0045] According to one embodiment of the present specification, a and b are the same or different from each other, and are each independently an integer from 1 to 6, preferably an integer from 1 to 4, more preferably 1 or 2, and most preferably 1.

[0046] According to one embodiment of the present specification, when n is an integer greater than or equal to 2, the structures of the repeating units within the parentheses may be the same or different from each other.

[0047] According to one embodiment of the present specification, the terminal group of the phenol resin containing the naphthol aralkyl skeleton may be, but is not limited to, hydrogen; a hydroxyl group; an ester group; a cyanate ester group; a substituted or unsubstituted alkyl group; or a substituted or unsubstituted aryl group.

[0048] In the present specification, the ester group may refer to an active ester group. The active ester group is an ester functional group that is susceptible to nucleophilic attack, and may be a modified form of the acyl or alkoxy component of a normal ester.

[0049] According to one embodiment of the present specification, the terminal group of the phenol resin containing the naphthol aralkyl skeleton may be, but is not limited to, hydrogen; a substituted or unsubstituted C1 to C30 alkyl group; or a substituted or unsubstituted C6 to C30 aryl group.

[0050] According to one embodiment of the present specification, the naphthol aralkyl skeleton-containing phenol resin includes, but is not limited to, SN-395, SN-485, SN-395 (Nippon Steel Chemical Co., Ltd.).

[0051] According to one embodiment of the present specification, the triazine skeleton-containing phenol resin can be represented by the following structural formula 2.

[0052] [Structural formula 2]

[0053]

[0054] In the above structural formula 2,

[0055] is a connection point with other structures,

[0056] X3 and X4 are the same or different from each other, and each independently represents a divalent organic group,

[0057] R1 is hydrogen; a substituted or unsubstituted alkyl group; a substituted or unsubstituted aryl group; or a substituted or unsubstituted amine group,

[0058] c and d are the same or different from each other, and are each independently an integer from 1 to 4,

[0059] m is an integer from 1 to 20.

[0060] According to one embodiment of the present specification, R1 may be hydrogen; a substituted or unsubstituted C1 to C30 alkyl group; a substituted or unsubstituted C6 to C30 aryl group; or a substituted or unsubstituted amine group.

[0061] According to one embodiment of the present specification, X3 and X4 may be the same as or different from each other, and may each independently be a substituted or unsubstituted alkylene group; a substituted or unsubstituted arylene group; or a substituted or unsubstituted divalent amine group.

[0062] According to one embodiment of the present specification, X3 and X4 may be the same as or different from each other, and may each independently be a substituted or unsubstituted C1 to C30 alkylene group; a substituted or unsubstituted C6 to C30 arylene group; or a substituted or unsubstituted divalent amine group.

[0063] According to one embodiment of the present specification, c and d are the same or different from each other, and are each independently an integer from 1 to 4, preferably an integer from 1 to 3, more preferably 1 or 2, and most preferably 1.

[0064] According to one embodiment of the present specification, the terminal group of the phenol resin containing the naphthol aralkyl skeleton may be hydrogen; a substituted or unsubstituted alkyl group; or a substituted or unsubstituted aryl group, and preferably may be hydrogen or a methyl group.

[0065] According to one embodiment of the present specification, the terminal group of the phenol resin containing the naphthol aralkyl skeleton may be hydrogen; a substituted or unsubstituted C1 to C30 alkyl group; or a substituted or unsubstituted C6 to C30 aryl group.

[0066] According to one embodiment of the present specification, the phenol resin containing the naphthol aralkyl skeleton includes, but is not limited to, LA-1356, LA-7052, LA-7054, LA-3018-80P, etc.

[0067] According to one embodiment of the present specification, the epoxy resin may be used without limitation as known in the art, but may be derived from an epoxy compound having two or more identical or different epoxy groups.

[0068] According to one embodiment of the present specification, the epoxy resin may be additionally used without limitation in addition to the phenol novolac type epoxy resin known in the art, and examples thereof include bisphenol type epoxy resin; novolac type epoxy resin; bixylenol type epoxy resin; biphenyl type epoxy resin; and one type may be used alone or two or more types may be mixed and used.

[0069] In one embodiment of the present specification, the epoxy resin includes, but is not limited to, YX4000H (Mitsubishi Chemical), YDF-170, YDF-172, YD-113, YD-114, YD-114E, YD-114F, YD-115, YD-115G, YD-115CA, KT-7804, KD-1818, YD-127, YD-128, YD-128S, YD-134, YD-136 (Kukdo Chemical), EXA-4850-150, EXA-4850-1000 (DIC), etc.

[0070] According to one embodiment of the present specification, the content of the epoxy resin may be 10 parts by weight or more based on 100 parts by weight of the entire curable resin composition.

[0071] According to one embodiment of the present specification, the content of the epoxy resin may be 11 parts by weight or more, 12 parts by weight or more, or 13 parts by weight or more, and 30 parts by weight or less, 29 parts by weight or less, or 28 parts by weight or less, based on 100 parts by weight of the total curable resin composition.

[0072] When the above epoxy resin falls within the above content range, it is possible to secure additionally improved moldability, processability, or properties necessary for forming an appropriate roughness during a desmear process.

[0073] In this specification, the range of surface roughness to be targeted may vary depending on the curing temperature, desmear conditions, etc.

[0074] According to one embodiment of the present specification, the content of the phenolic curing agent may be 10 parts by weight or more based on 100 parts by weight of the entire curable resin composition.

[0075] According to one embodiment of the present specification, the content of the phenolic curing agent may be 11 parts by weight or more, 12 parts by weight or more, or 13 parts by weight or more, and 30 parts by weight or less, 29 parts by weight or less, or 28 parts by weight or less, based on 100 parts by weight of the entire curable resin composition.

[0076] When the above phenolic curing agent falls within the above content range, additionally improved heat resistance, dielectric properties, or properties necessary for forming an appropriate roughness during a desmear process can be secured.

[0077] As long as it does not deviate from the context of the present invention, other types of hardeners may be included in addition to the above phenolic hardener.

[0078] According to one embodiment of the present specification, the content of the inorganic filler may be 50 parts by weight or more based on 100 parts by weight of the entire curable resin composition.

[0079] According to one embodiment of the present specification, the content of the inorganic filler may be 51 parts by weight or more, 53 parts by weight or more, or 55 parts by weight or more, and 100 parts by weight or less, 98 parts by weight or less, or 95 parts by weight or less, based on 100 parts by weight of the entire curable resin composition.

[0080] In this specification, the inorganic filler is meant to be used to control desired physical properties, such as hygroscopicity suppression, high storage modulus, low coefficient of thermal expansion (CTE), viscosity, and improved curability exhibited by the curable resin composition.

[0081] According to one embodiment of the present specification, the average particle diameter of the inorganic filler may be 0.01 ㎛ or more and 5 ㎛ or less.

[0082] According to one embodiment of the present specification, the inorganic filler may be surface-treated with a surface treatment agent such as a coupling agent.

[0083] According to one embodiment of the present specification, the inorganic filler may be, but is not limited to, silica, silicate, barium sulfate, alumina, etc.

[0084] In this specification, the silica may include, but is not limited to, spherical silica, fused silica, hollow silica, crystalline silica, amorphous silica, etc., and commercially available silica such as SOC1 and SOC2 (Admatex) may be used.

[0085] According to one embodiment of the present specification, the curable resin composition may further include at least one of a thermoplastic resin; a curing accelerator; and a solvent.

[0086] According to one embodiment of the present specification, the content of the thermoplastic resin may be 0.1 part by weight or more based on 100 parts by weight of the entire curable resin composition.

[0087] According to one embodiment of the present specification, the content of the thermoplastic resin may be 0.5 parts by weight or more, 0.7 parts by weight or more, or 1.0 parts by weight or more, and 5 parts by weight or less, 4.5 parts by weight or less, or 4 parts by weight or less, based on 100 parts by weight of the entire curable resin composition.

[0088] According to one embodiment of the present specification, the thermoplastic resin is not particularly limited as long as it is widely known in the art, and may include, for example, polyvinyl acetal resin (KS-1).

[0089] According to one embodiment of the present specification, the content of the curing accelerator may be 0.05 parts by weight or more based on 100 parts by weight of the entire curable resin composition.

[0090] According to one embodiment of the present specification, the content of the curing accelerator may be 0.08 parts by weight or more, 0.09 parts by weight or more, or 0.1 parts by weight or more, and 1 part by weight or less, 0.9 parts by weight or less, or 0.8 parts by weight or less, based on 100 parts by weight of the entire curable resin composition.

[0091] According to one embodiment of the present specification, the curing accelerator is not particularly limited as long as it is widely known in the art.

[0092] In the present specification, the curing accelerator is a substance for promoting the curing reaction of the thermosetting resin composition together with the curing agent, and is not particularly limited to one known in the art, but may include, for example, a pyridine-based curing accelerator (DMAP), an imidazole-based curing accelerator (e.g., 2PHZ-PW), an amine-based curing accelerator (e.g., dicyandiamide), an organic phosphine compound, an inorganic metal-based curing accelerator (e.g., cobalt(II) acetylacetonate (TCI)), and the like. One of the above-mentioned curing accelerators may be used alone, or two or more may be mixed and used.

[0093] According to one embodiment of the present disclosure, 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 curable 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.

[0094] 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.

[0095] 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.

[0096] The above ketone solvent may be methyl ethyl ketone (MEK), cyclohexanone, cyclopentanone, 2-heptanone, 3-heptanone, N-methyl-2-pyrrolidone, etc.

[0097] The above aromatic hydrocarbon solvent may be toluene, xylene, anisole, limonene, etc.

[0098] The above sulfoxide solvent may be dimethyl sulfoxide, etc.

[0099] According to one embodiment of the present specification, the curable resin composition further comprises an additive, and the additive may be selected from the group consisting of a leveling agent, a wetting agent, an antistatic agent, and an antioxidant.

[0100] In this specification, the leveling agent is a substance known in the art that controls the flowability of a curable resin composition when used in the future, thereby suppressing defects such as craters when applied to a surface in the future. In some cases, the leveling agent may be used alone or in combination of two or more types.

[0101] In this specification, the wetting agent is a substance known in the art that accelerates wetting and aids in the coagulation of the inorganic filler, and is not particularly limited thereto. In some cases, one type or a mixture of two or more types of wetting agents may be used.

[0102] 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.

[0103] 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.

[0104] Insulating film

[0105] Below is a description of an insulating film including a curable resin composition or a cured product thereof according to one embodiment of the present specification.

[0106] In the present specification, the cured product can be obtained by thermal curing and / or photocuring.

[0107] In this specification, the thermal curing may be performed by conditions and a heating device known in the art, and may be performed by curing and drying for a certain period of time under conditions of 100°C or higher, for example.

[0108] In this specification, the photocuring may be performed under conditions and using a UV irradiation device known in the art, for example, with UV (LED 3000 mJ / cm2 to 5000 mJ / cm2) having a wavelength of 365 nm.

[0109] In one embodiment of the present specification, the insulating film may have a coefficient of thermal expansion of 25 ppm / ℃ or less.

[0110] In this specification, the measurement and evaluation of the coefficient of thermal expansion (CTE) is performed by thermally curing a resin composition film at 190°C for 1 hour and 30 minutes, peeling off a support to obtain a sheet-like cured product, cutting the cured product into a test piece of about 4 mm in width and about 24 mm in length, and using a thermomechanical analysis device (TMA, Thermo Mechanical Analysis) to perform a thermomechanical analysis by the tensile weighting method, and then mounting the test piece on the device, measuring twice continuously under the measurement condition of a heating rate of 5°C / min. The coefficient of thermal expansion (α1, Tg or less) in the second measurement was calculated as the average linear thermal expansion rate (ppm) from 25°C to 150°C.

[0111] In one embodiment of the present specification, the insulating film may have a peel strength of 0.4 kgf / cm or more when measured according to ASTM D6862.

[0112] Since the above insulating film uses the above-described curable resin composition as is or a cured product thereof, the contents regarding the curable resin composition can be applied.

[0113] Printed circuit board

[0114] Below is a description of a printed circuit board according to one embodiment of the present specification.

[0115] Since the above printed circuit board uses the above-described curable resin composition as is or includes an insulating film using a cured product thereof, the contents of the above-described curable resin composition can be applied.

[0116] 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.

[0117] Example. Preparation of curable resin composition and insulating film

[0118] <Example 1>

[0119] As an epoxy resin, 20 parts by weight of a bisphenol type epoxy resin (YD-128, Kukdo Chemical), 30 parts by weight of a phenol novolac type epoxy resin (YDPN-639, Kukdo Chemical), and 60 parts by weight of a bixylenol type epoxy resin (YX-4000H), 70 parts by weight of a triazine skeleton-containing phenol resin (Phenolite LA-1356, DIC) and 40 parts by weight of a naphthol aralkyl skeleton-containing phenol resin (SN-485) as a phenolic hardener, and an average particle diameter (D) as an inorganic filler 50) 450 parts by weight of 0.1㎛ silica slurry (SOC2) and 10 parts by weight of polyvinyl acetal resin (KS-1) as a thermoplastic resin were mixed in MEK solvent to a total solid concentration of 70%, stirred at 250 rpm for 3 hours using a mechanical stirrer, and a curing accelerator (DMAP, 4-dimethylaminopyridine) was mixed using a paste mixer to prepare a curable resin composition.

[0120] Then, the curable resin composition was used as a coating liquid and coated on a 38㎛ PET film using an applicator, and then dried at 100℃ for 8 minutes to produce an insulating film having a thickness of 30㎛.

[0121] <Examples 2 to 5, Comparative Examples 1 to 5>

[0122] A curable resin composition was prepared in the same manner as in Example 1, except that the composition and contents were changed to those described in Table 1 below.

[0123]

[0124] * GPH-63 in Table 1 above is a biphenyl aralkyl phenol resin, and is a phenol curing agent that does not contain a naphthol aralkyl skeleton or a triazine skeleton.

[0125] <Experimental Example>

[0126] 1) Experimental Example 1: Measurement of coefficient of thermal expansion (CTE)

[0127] The insulating films manufactured in Examples 1 to 5 and Comparative Examples 1 to 5 were cut into samples with a width of 4.8 mm, a length of 16 mm, and a thickness of 30 μm, and after heat curing at 190°C for 90 minutes, the thermal expansion coefficients were measured in the range of 25°C to 120°C using TMA. The measurement results are shown in Table 2 below.

[0128] 2) Experimental Example 2: High-temperature reliability evaluation

[0129] After performing desmear treatment on the insulating films manufactured in Examples 1 to 5 and Comparative Examples 1 to 5 as described above, the surface roughness and copper foil adhesion were measured, and the measurement results are shown in Table 2 below.

[0130] Desmear treatment conditions: Sweller 60℃*10min, PerMn80℃*25min, Reduction50℃*5min

[0131] Surface roughness: Lens: i20x, FOV: 0.55x, WSI condition measurement

[0132] Copper foil adhesion measurement (peel strength): Sample size 10 mm × 100 mm, peel test (90° peel angle) and peel speed - 50 mm / min

[0133]

[0134] According to Table 2 above, under the same conditions with a high content of inorganic filler, the insulating films of Examples 1 to 5 achieved a high peel strength of 0.40 kgf / cm or more and a constant surface roughness value of 300 nm or more and 400 nm or less while satisfying a thermal expansion coefficient of 25 ppm / ℃ or less, thereby securing properties for forming a microcircuit and confirming that they are more suitable as insulating films than Comparative Examples 1 to 5.

[0135] In particular, Comparative Example 1 is an insulating film manufactured with a curable resin composition that excludes a triazine skeleton-containing phenol resin, but is unsuitable for use as an insulating film due to the occurrence of blisters. In addition, Comparative Examples 2 and 3 are insulating films manufactured with a curable composition that excludes a naphthol aralkyl skeleton phenol resin or includes another phenol-based curing agent instead thereof, but since the coefficient of thermal expansion exceeds 25 ppm / ℃, it is difficult to secure minimal warpage and may cause a low yield problem, and since the peel strength does not reach 0.4 kgf / cm, a short may occur in a future reliability test, so it is highly unsuitable for use as an insulating film. In addition, Comparative Examples 4 and 5 showed a thermal expansion coefficient exceeding 25 ppm / ℃ and a peel strength of less than 0.4 kgf / cm by using a triazine skeleton-containing phenol (LA-7052, LA-7054) having an amine group content of less than 15 wt%, which was insufficient for use as an insulating film, and did not reach the upper limit of a constant surface roughness range of 300 nm to 400 nm, making it unsuitable for forming a microcircuit.

Claims

1. A curable resin composition comprising an epoxy resin, a phenolic curing agent, and an inorganic filler, The above phenolic curing agent comprises a mixture of a naphthol aralkyl skeleton-containing phenol resin and a triazine skeleton-containing phenol resin, A curable resin composition having an amine group content of 15 wt% or more based on the entire triazine skeleton-containing phenol resin.

2. In claim 1, A curable resin composition comprising the above epoxy resin and a phenol novolac type epoxy resin.

3. In claim 1, A curable resin composition in which the composition ratio of the naphthol aralkyl skeleton-containing phenol resin and the triazine skeleton-containing phenol resin is 1:10 to 10:1 by weight.

4. In claim 1, The above naphthol aralkyl skeleton-containing phenol resin is a curable resin composition represented by the following structural formula 1: [Structural formula 1] In the above structural formula 1, is a connection point with other structures, X1 and X2 are the same or different from each other, and each independently represents a divalent organic group, a and b are equal to or different from each other and are each independently an integer from 1 to 6, n is an integer from 1 to 20.

5. In claim 1, The above triazine skeleton-containing phenol resin is a curable resin composition represented by the following structural formula 2: [Structural formula 2] In the above structural formula 2, is a connection point with other structures, X3 and X4 are the same or different from each other, and each independently represents a divalent organic group, R1 is hydrogen; a substituted or unsubstituted alkyl group; a substituted or unsubstituted aryl group; or a substituted or unsubstituted amine group, c and d are the same or different from each other, and are each independently an integer from 1 to 4, m is an integer from 1 to 20.

6. In claim 1, A curable resin composition in which the content of the above-mentioned inorganic filler is 50 parts by weight or more based on 100 parts by weight of the entire curable resin composition.

7. In claim 1, A curable resin composition further comprising at least one of a thermoplastic resin and a curing accelerator.

8. In claim 1, Contains more additives, A curable resin composition wherein the above additive is selected from the group consisting of a leveling agent, a wetting agent, an antistatic agent, and an antioxidant.

9. An insulating film comprising a curable resin composition according to any one of claims 1 to 8 or a cured product thereof.

10. In claim 9, Insulating film with a CTE (coefficient of thermal expansion) value of 25 ppm / ℃ or less.

11. In claim 9, Insulating film having a peel strength of 0.4 kgf / cm or more when measured according to ASTM D6862.

12. A printed circuit board comprising an insulating film according to claim 9.