Insulation film and printed circuit board comprising same

Abstract

The present specification provides insulation film and a printed circuit board comprising same, the insulation film comprising: a first layer comprising epoxy-based resin, a cyanate ester-based resin, and an inorganic filler surface-treated with phenylamino silane; and a second layer comprising epoxy-based resin, phenol-based resin, and an inorganic filler surface-treated with epoxy silane.

Description

Insulating film and printed circuit board containing the same

[0001] The present invention relates to an insulating film and a printed circuit board including the same.

[0002] This application claims the benefit of the filing dates of Korean Patent Application No. 10-2023-0161738, filed with the Korean Intellectual Property Office on November 21, 2023, and Korean Patent Application No. 10-2024-0152453, filed with the Korean Intellectual Property Office on October 31, 2024, 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 a printed wiring board and connects the components with copper wires to form an electronic circuit.

[0004] Typically, printed circuit boards are formed by multilayers with insulating copper wires. 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 interfacial surface area.

[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 that incorporates a build-up method has recently been proposed. The build-up method is a technology for alternately laminating a conductor layer of a circuit board and an organic insulating layer (or insulating film), and includes the steps of vacuum laminating the insulating film, followed by pre-curing, drilling, harmonic treatment, electroless plating, electrolytic plating, post-curing, and outer layer circuit formation.

[0007] In this technical field, in order to improve the quality of multilayer printed circuit boards, an insulating film that not only has excellent adhesion to the conductive wiring that constitutes the conductive layer, but also has excellent chemical resistance is required.

[0008] In addition, as the demand for low dielectric constant has become more sophisticated recently, insulating films with high heat resistance and low dielectric properties are also in demand.

[0009] [Prior Art Literature]

[0010] [Patent Document]

[0011] Republic of Korea Patent Publication No. 2012-0107277

[0012] The present invention seeks to provide an insulating film and a printed circuit board including the same.

[0013] One embodiment of the present specification comprises a first layer comprising an inorganic filler surface-treated with an epoxy resin, a cyanate ester resin, and a phenylamino silane; and

[0014] An insulating film comprising a second layer including an inorganic filler surface-treated with an epoxy resin, a phenol resin, and an epoxy silane is provided.

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

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

[0017] In addition, the insulating film according to the present specification exhibits low surface roughness and excellent plating adhesion.

[0018] In addition, the insulating film according to the present specification exhibits excellent dielectric properties.

[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] When a part in this specification 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] A method of manufacturing multilayer printed circuit boards by alternately laminating conductor layers and insulating films has been developed, and is currently being used for semiconductor packaging purposes. The manufacturing process of the multilayer printed circuit board first vacuum-laminated a build-up insulating film on the inner layer circuit, and then goes through the steps of precure → drilling → roughening → electroless plating → electrolytic plating → postcure → outer layer circuit formation. Here, the roughening process removes smear with an acid solution and simultaneously forms surface roughness by eroding the surface of the insulating film by a certain amount, which serves to increase adhesion with the copper foil layer formed in the subsequent process.

[0023] In terms of adhesion between the copper foil and the insulating layer, a high surface roughness after the harmonization process is advantageous. However, if the surface roughness is excessively high, the time required to remove the electroless plating increases, making it unsuitable. Therefore, the development of an insulating film with high plating adhesion and low surface roughness is necessary.

[0024] In the past, a composition containing silica particles as an inorganic filler in an epoxy resin and a phenolic hardener was used to manufacture a build-up insulating film. However, as the demand for low dielectric properties and low CTE (coefficient of thermal expansion) increased, a product using a cyanate ester hardener in an epoxy resin was developed.

[0025] However, the cured product of the above epoxy resin and cyanate ester curing agent had a problem in that the desired surface roughness could not be formed through the harmonization process when used alone.

[0026] Accordingly, the present specification seeks to provide an insulating film that exhibits not only low CTE characteristics but also desired surface roughness and high plating adhesion, and a printed circuit board including the same.

[0027] One embodiment of the present specification provides an insulating film comprising a first layer comprising an inorganic filler surface-treated with an epoxy resin, a cyanate ester resin, and a phenylamino silane; and a second layer comprising an inorganic filler surface-treated with an epoxy resin, a phenolic resin, and an epoxy silane.

[0028] In one embodiment of the present specification, it is preferable that the epoxy resin has two or more epoxy groups in one molecule. Specifically, the epoxy resin may include at least one selected from among bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, naphthalene type epoxy resin, anthracene epoxy resin, biphenyl type epoxy resin, tetramethyl biphenyl type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol A novolac type epoxy resin, bisphenol S novolac type epoxy resin, biphenyl novolac type epoxy resin, naphthol novolac type epoxy resin, naphthol phenol cocondensed novolac type epoxy resin, naphthol coresol cocondensed novolac type epoxy resin, aromatic hydrocarbon formaldehyde resin modified phenol resin type epoxy resin, triphenyl methane type epoxy resin, tetraphenylethane type epoxy resin, dicyclopentadiene phenol addition reaction type epoxy resin, phenol aralkyl type epoxy resin, and naphthol aralkyl type epoxy resin, but is not limited thereto.

[0029] Among these, from the viewpoints of heat resistance, insulation reliability, and adhesion, it is more preferable that the epoxy resin includes at least one type of bisphenol A type epoxy resin, bisphenol F type epoxy resin, naphthalene type epoxy resin, or biphenyl type epoxy resin.

[0030] In one embodiment of the present specification, the first layer and the second layer include an epoxy resin, thereby improving plating adhesion and enhancing the flexibility of the insulating film, thereby improving brittleness.

[0031] In one embodiment of the present specification, the cyanate ester resin may include at least one selected from novolac-type (phenol novolac-type, alkylphenol novolac-type, etc.) cyanate ester-type resin, dicyclopentadiene-type cyanate ester-type resin, bisphenol-type (bisphenol A-type, bisphenol F-type, bisphenol S-type, bisphenol M-type, etc.) cyanate ester-type resin, and some triazinated prepolymers thereof, but is not limited thereto.

[0032] Specifically, the cyanate ester resin is a bifunctional cyanate resin such as bisphenol A dicyanate, polyphenol cyanate, oligo(3-methylene-1,5-phenylene cyanate), 4,4'-methylenebis(2,6-dimethylphenyl cyanate), 4,4'-ethylidenediphenyl dicyanate, hexafluoro bisphenol A dicyanate, 2,2-bis(4-cyanate)phenylpropane, 1,1-bis(4-cyanatephenylmethane), bis(4-cyanate-3,5-dimethylphenyl)methane, 1,3-bis(4-cyanatephenyl-1-(methylethylidene))benzene, bis(4-cyanatephenyl)thioether, bis(4-cyanatephenyl) ether, etc.; a polyfunctional cyanate resin derived from a phenol novolac, a cresol novolac, a dicyclopentadiene structure-containing phenol resin, etc.; And these cyanate resins may include at least one selected from among some triazinated prepolymers.

[0033] The weight average molecular weight of the above cyanate ester resin may be 500 g / mol to 4,500 g / mol, or 600 g / mol to 3,000 g / mol, but is not limited thereto.

[0034] In one embodiment of the present specification, the weight average molecular weight can be measured by gel permeation chromatography (GPC) (polystyrene conversion).

[0035] In one embodiment of the present specification, the insulating film exhibits an effect of exhibiting a low dielectric constant by including a cyanate ester-based resin only in the first layer. Specifically, when a phenol resin is included, the dielectric constant is 0.013 to 0.015 at 10 GHz, but the insulating film according to one embodiment of the present specification exhibits an effect of exhibiting a low dielectric constant of 0.001 to 0.006 at 10 GHz by including a cyanate ester-based resin in the first layer.

[0036] In one embodiment of the present specification, the phenolic resin is a compound including a phenol skeleton or a naphthol skeleton, and may include at least one selected from a biphenyl-type phenolic resin and a novolac-type phenolic resin having excellent heat resistance, water resistance, etc. Specifically, the phenolic resin may be a novolac-type phenolic resin. More specifically, the phenolic resin may include at least one selected from a biphenylaralkyl-type phenol resin, a phenol novolac resin, a bisphenol A novolac resin, a cresol novolac resin, a phenol-modified xylene resin, an alkyl phenol resin, and a phenol-modified melamine resin.

[0037] In one embodiment of the present specification, the insulating film can form an appropriate roughness in the harmonic treatment step by including a phenolic resin only in the second layer, and exhibits the effect of improving polarity and thus improving plating adhesion.

[0038] In one embodiment of the present specification, the inorganic filler includes silica particles.

[0039] In one embodiment of the present specification, the inorganic filler includes only silica particles and does not include any other inorganic filler other than the silica particles.

[0040] In one embodiment of the present specification, the silica may include, but is not limited to, spherical silica, fused silica, hollow silica, crystalline silica, amorphous silica, etc.

[0041] In one embodiment of the present specification, the average particle diameter of the silica particles may be 0.3 μm or less, 0.2 μm or less, or 0.05 μm or more.

[0042] In one embodiment of the present specification, the inorganic filler, such as SOC1, SOC2 (Admatex), etc., is commercially available.

[0043] In one embodiment of the present specification, the inorganic filler is an inorganic filler surface-treated with phenylamino silane or an inorganic filler surface-treated with epoxy silane. Specifically, the first layer of the insulating film uses an inorganic filler surface-treated with phenylamino silane, and the second layer uses an inorganic filler surface-treated with epoxy silane.

[0044] In general, when the resin composition of the surface layer is etched to a certain thickness by wet roughening treatment, a shape in which the inorganic filler portion protrudes or a shape in which the inorganic filler is removed is formed, and at this time, the type of inorganic filler is an important factor in determining the surface roughness. When an inorganic filler (silica) that has not been surface-treated is used, there is a problem in that the surface roughness is too high even if the resin composition is etched well, resulting in reduced adhesion. On the other hand, according to one embodiment of the present specification, by applying the above-mentioned inorganic filler to the first layer and the second layer, respectively, a desired surface roughness can be formed by roughening treatment.

[0045] Specifically, as in one embodiment of the present specification, when the first layer and the second layer each include an inorganic filler surface-treated with different materials, the etching speeds for the harmonizing solution become different, resulting in uneven etching of the surface layer during the harmonizing process, thereby forming a desired surface roughness.

[0046] In one embodiment of the present specification, the surface-treated inorganic filler may include, but is not limited to, an epoxy silane surface-treated product (Admatex SC-2050-MB), a phenyl amino silane surface-treated product (Admatex SC-2050-MTO), etc.

[0047] In one embodiment of the present specification, the first layer and the second layer may further include a thermoplastic resin to improve mechanical strength, film moldability, etc. The thermoplastic resin may include at least one selected from a phenoxy resin, a polyimide resin, a polyamideimide resin, a polyetherimide resin, a polysulfone resin, a polyethersulfone resin, a polyphenylene ether resin, a polycarbonate resin, a polyetheretherketone resin, a polyester resin, a polyvinyl acetal resin, and a polyvinyl butyral resin. It is more preferable that the thermoplastic resin include a phenoxy resin.

[0048] In one embodiment of the present specification, the first layer and the second layer may each further include at least one thermoplastic resin selected from among phenoxy resin, polyimide resin, polyamideimide resin, polyetherimide resin, polysulfone resin, polyethersulfone resin, polyphenylene ether resin, polycarbonate resin, polyetheretherketone resin, polyester resin, polyvinyl acetal resin, and polyvinyl butyral resin.

[0049] In one embodiment of the present specification, 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.

[0050] In one embodiment of the present specification, the first layer and the second layer include a thermoplastic resin, thereby maintaining a film form during the curing step. Specifically, if the thermoplastic resin is not included, the viscosity decreases upon temperature increase, resulting in a problem of flow. On the other hand, in one embodiment of the present specification, by including a thermosetting resin, the viscosity is maintained or improved, thereby maintaining a film form during the curing step.

[0051] In one embodiment of the present specification, the first layer and the second layer each further include an additive, and the additive is at least one selected from a curing accelerator, a leveling agent, a wetting agent, an antistatic agent, a flame retardant, a crosslinking agent, a curing agent, and a polymerization initiator.

[0052] In one embodiment of the present specification, the curing accelerator is a substance that shortens the curing time, and is known in the art, and may be a phosphorus-based curing accelerator, an amine-based curing accelerator, an imidazole-based curing accelerator, etc. If necessary, one type of curing accelerator may be used alone or two or more types may be used in combination, and the content thereof may be appropriately changed as long as it does not exceed the scope of the present invention.

[0053] Examples of the above-mentioned phosphorus-based curing accelerator include triphenyl phosphine, and examples of the above-mentioned amine-based curing accelerator include triethylamine, tributylamine, etc., but are not particularly limited.

[0054] As the above imidazole accelerator, 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, It may include at least one selected from 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline, and 2-phenylimidazoline.

[0055] The above curing accelerator may additionally include at least one selected from a metal compound, an amine compound, and an organic phosphine compound.

[0056] Examples of the above metal compounds include organometallic complexes or organometallic salts of metals such as cobalt, copper, zinc, iron, nickel, manganese, and tin. Examples of the above organometallic complexes include, but are not limited to, cobalt(II) acetylacetonate, cobalt(III) acetylacetonate, copper(II) acetylacetonate, zinc(II) acetylacetonate, iron(III) acetylacetonate, nickel(II) acetylacetonate, and manganese(II) acetylacetonate. In addition, examples of the above organometallic salts include, but are not limited to, zinc octylate, tin octylate, zinc naphthenate, cobalt naphthenate, tin stearate, and zinc stearate.

[0057] The above amine compounds include, but are not limited to, triethylamine, tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6,-tris(dimethylaminomethyl)phenol, and 1,8-diazabicyclo(5,4,0)-undecene.

[0058] In one embodiment of the present specification, the leveling agent controls the flowability of the curable resin composition when used in the future, so that when applied to a surface in the future, defects such as craters are eliminated. Examples of the leveling agent known in the art include, but are not particularly limited to, BYK 350, BYK 354, BYK 356, BYK 359, and BYK 399. In some cases, one type or two or more types of the leveling agent may be used in combination, and the content thereof may be appropriately changed as long as it does not depart from the scope of the present invention.

[0059] In one embodiment of the present specification, the wetting agent is a substance known in the art that accelerates wetting and aids in the coagulation of the inorganic filler. The wetting agent is not particularly limited to a specific substance. If necessary, one type of wetting agent may be used alone or in combination of two or more types, and the content thereof may be appropriately varied without departing from the scope of the present invention.

[0060] In one embodiment of the present specification, the antistatic agent is a substance known in the art that provides an antistatic effect, and is not particularly limited. If necessary, one type of antistatic agent may be used alone or in combination of two or more types, and the content thereof may be appropriately varied without departing from the scope of the present invention.

[0061] In one embodiment of the present specification, the flame retardant is a substance known in the art that reduces flammability or delays combustion, and is not particularly limited. If necessary, one type of flame retardant may be used alone or in combination of two or more types, and the content thereof may be appropriately varied without departing from the scope of the present invention.

[0062] In one embodiment of the present specification, the crosslinking agent is a substance that forms a crosslinking bond between polymers, and is known in the art, and includes TAIC, DAIC (allylic type), ALP-d (Benxoxazine type), etc., but is not particularly limited. If necessary, one type of crosslinking agent may be used alone or two or more types may be used in combination, and the content thereof may be appropriately changed as long as it does not exceed the scope of the present invention.

[0063] In one embodiment of the present specification, the curing agent is a substance that is added to a curable resin to aid the curing reaction, and may be classified into an activated ester curing agent, a phenol curing agent, a cyanate ester curing agent, etc., as known in the art, but is not particularly limited. If necessary, one type of curing agent may be used alone or two or more types may be used in combination, and the content thereof may be appropriately changed as long as it does not deviate from the scope of the present invention.

[0064] In one embodiment of the present specification, the polymerization initiator is a substance that initiates polymerization by generating radicals or (positive) ions by a specific stimulus, and is known in the art, and includes dicumyl peroxide, t-butylcumyl peroxide, di-t-butyl peroxide, etc., but is not particularly limited. If necessary, one type of polymerization initiator may be used alone or two or more types may be used in combination, and the content thereof may be appropriately changed as long as it does not depart from the scope of the present invention.

[0065] In one embodiment of the present specification, the weight ratio of the inorganic filler:resin of the first layer is 80:20 to 40:60.

[0066] At this time, the resin described in the content ratio of the first layer is the sum of the weights of all resins included in the first layer. For example, if the first layer includes an epoxy resin, a cyanate ester resin, and a phenoxy resin, the resin is the sum of the total weights of the epoxy resin, the cyanate ester resin, and the phenoxy resin.

[0067] In one embodiment of the present specification, the weight ratio of the inorganic filler:resin of the second layer is 80:20 to 40:60.

[0068] At this time, the resin described in the content ratio of the second layer is the sum of the weights of all resins included in the second layer. For example, if the second layer includes an epoxy resin, a phenol resin, and a phenoxy resin, the resin is the sum of the total weights of the epoxy resin, the phenol resin, and the phenoxy resin.

[0069] If the content of the above-mentioned inorganic filler is less than 40 wt% or more than 80 wt%, it is not preferable because it may be difficult to implement the desired surface shape through the harmonization process.

[0070] In one embodiment of the present specification, the thickness of the first layer is 15 μm to 25 μm. When the above range is satisfied, it is effective in exhibiting appropriate dielectric properties and CTE properties.

[0071] In one embodiment of the present specification, the thickness of the second layer is 1 μm to 5 μm. If the thickness of the second layer is less than 1 μm, it is completely etched during the harmonizing process, and thus the desired adhesion cannot be exhibited. If the thickness of the second layer exceeds 5 μm, there is a problem in that it cannot exhibit appropriate dielectric properties and CTE properties.

[0072] In one embodiment of the present specification, the insulating film has a thermal expansion coefficient value of 25 ppm / ℃ or less, measured in the range of 25°C to 120°C. Specifically, the thermal expansion coefficient value is 24 ppm / ℃ or less, or 22 ppm / ℃ or less, and 0 ppm / ℃ or more.

[0073] The above thermal expansion coefficient is a value measured using a TMA (thermos mechanical analyzer) in the range of 25°C to 120°C after heat-curing the insulating film at 190°C for 90 minutes.

[0074] Insulating films that fall within the above-mentioned range of thermal expansion coefficients will not experience deformation such as peeling or cracking, as there will be little difference in expansion rate with the support in the future.

[0075] In one embodiment of the present specification, the insulating film has a dissipation factor (Df) of 0.001 or more and 0.006 or less as measured at 10 GHz according to ASTM D2520. Specifically, the dissipation factor may be 0.0011 or more, 0.0012 or more, or 0.0013 or more, and 0.0058 or less, 0.0055 or less, or 0.0052 or less.

[0076] An insulating film having the above dielectric constant can minimize loss of future transmission signals.

[0077] In one embodiment of the present specification, the insulating film has an adhesion strength of greater than 0.5 kgf / cm as measured according to ASTM D6862. Specifically, the adhesion strength is 0.52 kgf / cm or more or 0.55 kgf / cm or more and 2 kgf / cm or less or 1.8 kgf / cm or less.

[0078] In one embodiment of the present specification, a first insulating film composition and a second insulating film composition are used to form the first layer and the second layer.

[0079] In one embodiment of the present specification, the composition for the first insulating film includes an epoxy resin, a cyanate ester resin, and an inorganic filler surface-treated with phenylamino silane.

[0080] In one embodiment of the present specification, the composition for the second insulating film includes an epoxy resin, a phenol resin, and an inorganic filler surface-treated with epoxy silane.

[0081] In one embodiment of the present specification, the first insulating film composition and the second insulating film composition further include a thermoplastic resin.

[0082] In one embodiment of the present specification, the first insulating film composition and the second insulating film composition further include an additive.

[0083] In one embodiment of the present specification, the materials such as epoxy resin, cyanate ester resin, phenol resin, inorganic filler, thermoplastic resin, and additives included in the first insulating film composition and the second insulating film composition are each as described above in the insulating film.

[0084] In one embodiment of the present specification, the first insulating film composition and the second insulating film composition further comprise 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 an insulating film. 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.

[0085] 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.

[0086] 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.

[0087] The above ketone solvent may be methyl ethyl ketone (MEK), cyclohexanone, cyclopentanone, 2-heptanone, 3-heptanone, N-methyl-2-pyrrolidone, etc.

[0088] The above aromatic hydrocarbon solvent may be toluene, xylene, anisole, limonene, etc.

[0089] The above sulfoxide solvent may be dimethyl sulfoxide, etc.

[0090] One embodiment of the present specification provides a printed circuit board including the above-described insulating film.

[0091] In one embodiment of the present specification, the insulating film includes a base film, and the base film, the first layer, and the second layer are sequentially laminated. When the lamination order is satisfied, it is effective in exhibiting appropriate dielectric properties and CTE properties.

[0092] On the other hand, when the above-mentioned base film, the second layer, and the first layer are sequentially laminated, there is a problem that the surface roughness is large and the adhesion is low.

[0093] In one embodiment of the present specification, the insulating film may be applied as an insulating layer of a printed circuit board. In addition, the insulating film may be used as an interlayer insulating material of a multilayer printed circuit board.

[0094] In one embodiment of the present specification, the insulating film may be used as a build-up insulating layer for manufacturing a predetermined circuit board. For example, the insulating film may be used for manufacturing an interlayer insulating layer constituting various types of package substrates, including a flexible printed circuit board (flexible PCB), a rigid printed circuit board (rigid PCB), a rigid-flexible printed circuit board (RF PCB), and a build-up printed circuit board.

[0095] In one embodiment of the present specification, the printed circuit board may be a multilayer printed circuit board, and the number of layers included in the multilayer printed circuit board is not limited. For example, depending on the purpose of use, use, etc. of the multilayer printed circuit board, the multilayer printed circuit board may include a structure of 2 to 20 layers.

[0096] 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 ordinary skill in the art.

[0097]

[0098] <Example>

[0099] Example 1.

[0100] 5 parts by weight of bisphenol A type epoxy resin (YD-128, Kukdo Chemical), 3 parts by weight of bisphenol F type epoxy resin (KDS-8170), 2 parts by weight of naphthalene type epoxy resin (HP-4032D, DIC), 5 parts by weight of biphenyl type epoxy resin (YX4000UH, Mitsubishi Chemical), 20 parts by weight of cyanate ester resin (LMP-500S, Arsada), 10 parts by weight of phenoxy resin (YX6954BH30, Mitsubishi Chemical), 100 parts by weight of spherical silica surface-treated with phenylamino silane (average particle diameter 0.5㎛, SOC2, Admatex), and 1 part by weight of imidazole type curing accelerator (2PHZ-PW) were mixed in MEK solvent so that the total solid concentration became 70%, and then stirred with a stirrer at 250 rpm for 3 hours to obtain a resin mixture. 1 was manufactured.

[0101] 5 parts by weight of bisphenol A type epoxy resin (YD-128, Kukdo Chemical), 2 parts by weight of naphthalene type epoxy resin (HP-4032D, DIC), 10 parts by weight of biphenyl type epoxy resin (YX4000UH, Mitsubishi Chemical), 25 parts by weight of biphenyl aralkyl type phenol resin (GPH 103, Nippon Gunpowder Chemical), 20 parts by weight of phenoxy resin (YX6954BH30, Mitsubishi Chemical), 100 parts by weight of spherical silica surface-treated with epoxy silane (average particle diameter 0.5㎛, SOC2, Admatex), and 1 part by weight of imidazole type curing accelerator (2PHZ-PW) were mixed in MEK solvent so that the total solid concentration became 60%, and then stirred with a stirrer at 250 rpm for 3 hours to prepare resin mixture 2.

[0102] The manufactured resin mixture 1 was uniformly applied to a 20 ㎛ thickness on a 40 ㎛ PET film and dried at 100°C for 5 minutes to produce a first layer. The manufactured resin mixture 2 was uniformly applied to a 5 ㎛ thickness thereon and dried at 100°C for 8 minutes to produce a second layer, thereby producing an insulating film with a total thickness of 25 ㎛ of the first and second layers.

[0103]

[0104] Example 2.

[0105] An insulating film was manufactured in the same manner as in Example 1, except that the resin mixture 1 was uniformly applied to a thickness of 19 μm and the resin mixture 2 was uniformly applied to a thickness of 6 μm.

[0106]

[0107] Comparative Example 1.

[0108] The resin mixture 1 prepared in Example 1 was uniformly applied onto a 40㎛ PET film and then dried at 100℃ for 5 minutes to prepare an insulating film having a thickness of 25㎛.

[0109]

[0110] Comparative Example 2.

[0111] The resin mixture 2 prepared in Example 1 was uniformly applied onto a 40㎛ PET film and then dried at 100℃ for 5 minutes to prepare an insulating film having a thickness of 25㎛.

[0112]

[0113] Comparative Example 3.

[0114] An insulating film was manufactured in the same manner as in Example 1, except that spherical silica surface-treated with phenylamino silane was used instead of spherical silica surface-treated with epoxy silane when manufacturing resin mixture 2 in Example 1.

[0115]

[0116] Comparative Example 4.

[0117] An insulating film was manufactured in the same manner as in Example 1, except that spherical silica surface-treated with epoxy silane was used instead of spherical silica surface-treated with phenylamino silane when manufacturing resin mixture 1 in Example 1.

[0118]

[0119] Comparative Example 5.

[0120] An insulating film was manufactured in the same manner as in Example 1, except that the resin mixture 2 manufactured in Example 1 was uniformly applied to a 5 μm thickness on a 40 μm PET film and then dried at 100°C for 5 minutes to produce a first layer, and the resin mixture 1 manufactured thereon was uniformly applied to a 20 μm thickness and then dried at 100°C for 8 minutes to produce a second layer, thereby producing an insulating film having a total thickness of 25 μm for the first and second layers.

[0121]

[0122] <Experimental Example>

[0123] The properties of the insulating films manufactured in the above examples and comparative examples were evaluated and are shown in Table 1 below. The evaluation method for the properties listed in Table 1 below is as follows.

[0124]

[0125] Experimental Example 1. Measurement of dielectric constant and dielectric loss tangent

[0126] The insulating film manufactured in the above examples and comparative examples was heat-cured by heating at 190°C for 90 minutes, and the PET film as a support was peeled off to obtain a cured product.

[0127] The permittivity and dielectric loss tangent were measured at 10 GHz using Agilent's E5071C equipment for the cured product under conditions of a measurement temperature of 20 to 25°C and a humidity of 50% or less. The measurement results are shown in Table 1 below.

[0128]

[0129] Experimental Example 2. Measurement of the coefficient of thermal expansion (CTE)

[0130] After the insulating film was heat-cured at 190°C for 90 minutes, the thermal expansion coefficient was measured in the range of 25°C to 120°C using a thermo mechanical analyzer (TMA). The measurement results are as shown in Table 1 below.

[0131]

[0132] Experimental Example 3. Measurement of surface roughness (Ra, nm) and adhesion

[0133] 1) Laminate

[0134] The insulating films manufactured in the above examples and comparative examples were laminated onto a copper substrate that had undergone a harmonizing process using a vacuum pressurized laminator.

[0135] 2) Hardening

[0136] An insulating film laminated to a copper substrate was pre-cured in a hot air oven at 100°C for 30 minutes and then at 180°C for 30 minutes to obtain an insulating layer.

[0137] 3) Harmony processing

[0138] The heat-cured substrate was treated with a swelling solution (Swelling Deep Securigant P, Atotech) at 80°C for 5 minutes, an oxidizing solution (Concentrate Compact P, Atotech) at 75°C for 20 minutes, and then a neutralizing solution (Reduction Solution Securigant P, Atotech) at 50°C for 20 minutes.

[0139] 4) Plating

[0140] After forming a plating layer with a thickness of 30 μm on the substrate on which the harmony treatment was completed, heat treatment was performed at 190°C for 60 minutes.

[0141] 5) Surface roughness (Ra, nm) measurement

[0142] The surface roughness (Ra) of the insulating film subjected to the harmonic treatment was measured five times per sample using an Optical Profiler (Nanoview 3D surface profiler NV-2700, Nanosystem) (WSI mode, 20x lens), and the average value was used to obtain the surface roughness. The measurement results are as shown in Table 1 below.

[0143] 6) Adhesion measurement

[0144] The adhesion between the plating layer and the insulating layer of the plated insulating film was measured according to ASTM D6862. The measurement results are shown in Table 1 below.

[0145]

[0146] Dielectric constantDielectric coefficient of thermal expansion (CTE)Surface roughness (Ra)Adhesion (ppm / ℃)(nm)(kgf / cm)Example 13.20.005222000.7Example 23.10.006252000.6Comparative example 13.00.005209000.5Comparative example 23.20.013392000.5Comparative example 33.20.007274000.2Comparative example 43.20.007292000.5Comparative example 53.20.005229000.4

[0147] As shown in the above results, Example 1 exhibited excellent dielectric constant and adhesion while showing low surface roughness and coefficient of thermal expansion. Example 2 exhibited low surface roughness as the insulating film included the first and second layers, but when the thickness of the second layer exceeded 5 μm, it was confirmed that the coefficient of thermal expansion and dielectric loss tangent were large compared to Example 1.

[0148] However, in the case of Comparative Example 1, in which the insulating film consisted of only the first layer, a large surface roughness was exhibited, and in the case of Comparative Example 2, in which the insulating film consisted of only the second layer, a large thermal expansion coefficient was exhibited.

[0149] In addition, in the case of Comparative Example 3, in which the inorganic filler constituting the first and second layers was the same (the same inorganic filler surface-treated with phenylamino silane), both the thermal expansion coefficient and surface roughness were large and the adhesion was low, and in the case of Comparative Example 4 (the same inorganic filler surface-treated with epoxy silane), the thermal expansion coefficient was large.

[0150] Furthermore, in the case of Comparative Example 5, where the lamination order of the first and second layers was reversed compared to the embodiment, the surface roughness was large and the adhesion was low.

[0151] Through this, it can be confirmed that the insulating film according to one embodiment of the present specification has an appropriate surface roughness and coefficient of thermal expansion, while at the same time having excellent adhesion and dielectric constant.

[0152] Therefore, a multilayer printed circuit board having excellent wiring adhesion, chemical resistance, etc. can be manufactured using an insulating film according to one embodiment of the present specification.

Claims

1. A first layer comprising an inorganic filler surface-treated with an epoxy resin, a cyanate ester resin and a phenylamino silane; and An insulating film comprising a second layer comprising an inorganic filler surface-treated with an epoxy resin, a phenol resin and an epoxy silane.

2. An insulating film according to claim 1, wherein the thickness of the first layer is 15 ㎛ to 25 ㎛.

3. An insulating film according to claim 1, wherein the thickness of the second layer is 1 ㎛ to 5 ㎛.

4. An insulating film according to claim 1, wherein the cyanate ester resin comprises at least one selected from a novolac-type cyanate ester resin, a dicyclopentadiene-type cyanate ester resin, a bisphenol-type cyanate ester resin, and a prepolymer partially triazinated therefrom.

5. An insulating film according to claim 1, wherein the phenolic resin comprises at least one selected from a biphenyl-type phenolic resin and a novolac-type phenolic resin.

6. An insulating film according to claim 1, wherein the first layer and the second layer each further include at least one thermoplastic resin selected from a phenoxy resin, a polyimide resin, a polyamideimide resin, a polyetherimide resin, a polysulfone resin, a polyethersulfone resin, a polyphenylene ether resin, a polycarbonate resin, a polyetheretherketone resin, a polyester resin, a polyvinyl acetal resin, and a polyvinyl butyral resin.

7. In claim 1, the first layer and the second layer each further include an additive, An insulating film wherein the above additive is at least one selected from a curing accelerator, a leveling agent, a wetting agent, an antistatic agent, a flame retardant, a crosslinking agent, a curing agent, and a polymerization initiator.

8. In claim 1, the insulating film includes a base film, An insulating film in which the above-mentioned base film, the first layer, and the second layer are sequentially laminated.

9. In claim 1, the insulating film has a thermal expansion coefficient value of 25 ppm / ℃ or less measured in a range of 25℃ to 120℃.

10. In claim 1, the insulating film is an insulating film having a dielectric constant of 0.001 or more and 0.006 or less as measured at 10 GHz according to ASTM D2520.

11. In claim 1, the insulating film has an adhesion strength of more than 0.5 kgf / cm as measured according to ASTM D6862.

12. A printed circuit board comprising an insulating film according to any one of claims 1 to 11.