Resin film and its uses

Abstract

To provide a resin film which is usable as a dielectric material of a copper-clad laminate, and is excellent in adhesion to a copper foil and heat resistance.SOLUTION: When characteristic evaluation of a resin film is performed by Fourier transform infrared spectroscopy (FTIR), the Fourier transform infrared spectrum of the resin film has signal intensity A of 2,205 cm-1 to 2,322 cm-1, and signal intensity B of 1,472 cm-1 to 1,523 cm-1, and satisfies 0.70≤A / B≤1.95.SELECTED DRAWING: None

Description

[Technical Field]

[0001] (Priority Claim) This application claims the benefit of Taiwan Patent Application No. 11135100, filed September 16, 2022, the contents of which are incorporated herein by reference in their entirety.

[0002] The present invention provides a resin film, particularly a resin film having excellent adhesion to copper foil and heat resistance, and uses of the resin film. [Background technology]

[0003] A printed circuit board (PCB) can be used as the base of electronic devices, and can mount other electronic components and electrically connect the components to provide a stable circuit operating environment. Printed circuit boards are mainly made of copper clad laminates, which are formed by overlapping copper foil, which is used as a dielectric layer and a conductive layer.

[0004] As electronic devices continue to develop and their performance improves, IC configurations are becoming smaller, lighter, and thinner, requiring high-density multilayer printed wiring boards. This requires printed wiring boards to have better dimensional stability, and the dielectric layer of printed wiring boards must have good adhesion to copper foil and heat resistance to prevent wiring connection breaks. Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a film material that can be used as a dielectric material for copper-clad laminates, has excellent adhesion to copper foil, and has excellent heat resistance. Compared to conventional liquid or powder materials, the film material of the present invention is provided with a uniform thickness, and is therefore advantageous in that it can provide a dielectric material with a large area.

[0006] Therefore, an object of the present invention is to characterize a resin film by Fourier transform infrared spectroscopy (FTIR), and to determine whether the Fourier transform infrared spectrum of the resin film is at 2205 cm-1 ~2322cm -1 signal intensity A and 1472cm -1 ~1523cm -1 and a signal strength B of 0.70≦A / B≦1.95. [Means for solving the problem]

[0007] In some embodiments of the present invention, the Fourier transform infrared spectroscopy is performed by placing a resin film in a Fourier transform infrared spectroscopy device and measuring the wavelength at 650 cm -1 ~4000cm -1 The absorption spectrum is measured in the range of 1000 s, and the signal intensities A and B are measured using the attenuated total reflection method. The resolution of the Fourier transform infrared spectrometer is 1 cm -1 The number of scans of the spectrum is 12, and the signal intensity is the absorbance at each wavelength.

[0008] In some embodiments of the present invention, the Fourier transform infrared spectrum of the resin film has a peak at 2943 cm -1 ~2990cm -1 and 0.05≦C / B≦0.4.

[0009] In some embodiments of the present invention, the resin film comprises an epoxy resin and a cyanate resin.

[0010] In some embodiments of the present invention, the epoxy resin is an epoxy resin having conjugated unsaturated bonds, and preferably an aromatic epoxy resin.

[0011] In some embodiments of the present invention, the epoxy resin is selected from the group consisting of bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, phenol epoxy resins, biphenyl epoxy resins, aralkyl epoxy resins, naphthalene epoxy resins, naphthol epoxy resins, epoxides of condensates of phenols having a phenolic hydroxyl group and aromatic aldehydes, biphenyl aralkyl epoxy resins, fluorene epoxy resins, xanthene epoxy resins, dicyclopentadiene epoxy resins, poly(triglycidyl isocyanurate), and combinations thereof.

[0012] In some embodiments of the present invention, the cyanate resin is selected from the group consisting of bisphenol A dicyanate, bisphenol E-type cyanate resin, bisphenol F dicyanate, bisphenol S dicyanate, phenol cyanate resin, biphenyl dicyanate, biphenol dicyanate, hexafluorobisphenol A dicyanate, 2,2-bis(4-cyanato)phenylpropane, 1,1-bis(4-cyanatophenylmethane), bis(4-cyanato-3,5-dimethylphenyl)methane, 1,3-bis(4-cyanatophenyl-1-(methylethylidene)benzene), bis(4-cyanatophenyl)sulfide, bis(4-cyanatophenyl)ether, phenol cyanate resins containing a dicyclopentadiene structure, and combinations thereof.

[0013] In some embodiments of the present invention, the resin film further comprises a filler, and the amount of the filler is 70% by weight to 88% by weight based on the solid content of the resin film.

[0014] In some embodiments of the present invention, the filler is selected from the group consisting of silica, aluminum oxide, magnesium oxide, magnesium hydroxide, calcium carbonate, talc, clay, aluminum nitride, boron nitride, aluminum hydroxide, aluminum silicon carbide, silicon carbide, sodium carbonate, titanium dioxide, zinc oxide, zirconium oxide, quartz, diamond, diamond-like carbon, graphite, calcined kaolin, puriane, mica, hydrotalcite, polytetrafluoroethylene (PTFE) powder, glass beads, ceramic whiskers, carbon nanotubes, strontium titanate, and combinations thereof.

[0015] In some embodiments of the present invention, the resin film further comprises carbon black.

[0016] In some embodiments of the present invention, the resin film further comprises a cure accelerator selected from the group consisting of an amine-based cure accelerator, a guanidine-based cure accelerator, an imidazole-based cure accelerator, and combinations thereof.

[0017] In some embodiments of the present invention, the resin film has a thickness of 25 μm to 300 μm.

[0018] Another object of the present invention is to provide a copper-clad laminate comprising a dielectric layer and a copper foil covering the surface of the dielectric layer, wherein the dielectric layer is provided from the aforementioned resin film.

[0019] Another object of the present invention is to provide an encapsulating material containing the above-mentioned resin film.

[0020] In order to make the above objectives, technical features and advantages of the present invention more apparent, the present invention will be described in detail below with reference to some specific embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0021] Some specific embodiments of the present invention will be described in detail below, although the present invention may be embodied in various embodiments and should not be limited to the embodiments described herein.

[0022] Unless otherwise stated, the terms "a", "the", and the like used in the specification, and particularly in the appended claims, are intended to include both the singular and the plural.

[0023] Unless otherwise specified, when describing components in a solution, mixture, composition, or resin film herein, the amount of each component is calculated on a dry weight basis, i.e., regardless of the weight of the solvent. For example, if 100 parts by weight of a resin film consists of 20 parts by weight of solvent and 40 parts by weight of filler, the solids content of the resin film is 80 parts by weight, and the amount of filler is 50% by weight based on the solids content of the resin film.

[0024] 1. Resin film The present invention can improve the adhesiveness of a resin film to a metal foil (e.g., copper foil) and the heat resistance of the resin film by controlling the infrared spectrum signal intensity ratio A / B of the resin film. The resin film of the present invention and its uses are described in detail below.

[0025] 1.1. Infrared spectral characteristics of resin films When the resin film of the present invention is characterized by Fourier transform infrared spectroscopy (FTIR), the Fourier transform infrared spectrum of the resin film has a wavelength of 2205 cm -1 ~2322cm -1 signal intensity A and 1472cm -1 ~1523cm -1and 0.70≦A / B≦1.95. For example, the A / B values ​​are 0.70, 0.71, 0.72, 0.73, 0.74, 0.75, 0.76, 0.77, 0.78, 0.79, 0.80, 0.81, 0.82, 0.83, 0.84, 0.85, 0.86, 0.87, 0.88, 0.89, 0.90, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99, 1.00, 1.01 ,1.02,1.03,1.04,1.05,1.06,1.07,1.08,1.09,1.10,1.11,1.12,1.13,1.14,1.15,1.16,1.17,1.18,1.19,1.20,1.21,1.22,1.23,1.24,1.25,1.26,1.27,1.28,1.29,1.30,1.31,1.32,1.33,1.34,1.35 5, 1.36, 1.37, 1.38, 1.39, 1.40, 1.41, 1.42, 1.43, 1.44, 1.45, 1.46, 1.47, 1.48, 1.49, 1.50, 1.51, 1.52, 1.53, 1.54, 1.55, 1.56, 1.57, 1.58, 1.59, 1.60, 1.61, 1.62, 1.63, 1.64, 1.65, 1.66, 1.67, 1.68, 1. 1.69, 1.70, 1.71, 1.72-1.73, 1.74, 1.75, 1.76, 1.77, 1.78, 1.79, 1.80, 1.81, 1.82, 1.83, 1.84, 1.85, 1.86, 1.87, 1.88, 1.89, 1.90, 1.91, 1.92, 1.93, 1.94, or 1.95, or within a range between any two of the values ​​described herein. In some embodiments of the present invention, the ratio of signal intensity A to signal intensity B (A / B) is 0.7 to 1.9. -1 ~2322cm -1 The signal intensity A represents the absorption peak of the cyanate functional group, 1472 cm -1 ~1523cm -1The signal intensity B in the graph represents the absorption peak of the carbon-carbon double bond in the benzene ring. Without wishing to be bound by any theory, it is believed that within a certain range of A / B values, the higher the A / B value, the easier it is to form triazine, resulting in more lone-pair electrons on the -N, and thus better adhesion of the resin film to the copper foil. A smaller A / B value results in fewer lone-pair electrons on the -N, resulting in poor adhesion between the resin film and the copper foil. However, when the A / B value exceeds the upper limit of the certain range, the excess triazine makes the resin film brittle and unable to effectively adhere to the copper foil.

[0026] In some embodiments of the present invention, when the resin film of the present invention is characterized by Fourier transform infrared spectroscopy (FTIR), the Fourier transform infrared spectrum of the resin film further contains a peak at 2943 cm -1 ~2990cm -1 and the ratio of signal intensity C to signal intensity B (C / B) is 0.05≦C / B≦0.4. For example, the C / B value can be 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.30, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, or 0.40, or a range between any two of the values ​​described herein. The signal intensity C represents the absorption peak of the -CH single bond in the composition. An increase in the signal intensity C results in a decrease in the A / B value, and vice versa.

[0027] The infrared spectral characteristics of the resin film of the present invention can be measured using a Fourier transform infrared spectrometer as follows: the resin film is placed in the Fourier transform infrared spectrometer, and a 650 cm -1 ~4000cm -1 The absorption spectrum in the range of 1 cm is measured, and the signal intensities A and B are measured using the attenuated total reflection method. The resolution of the Fourier transform infrared spectrometer is 1 cm. -1The number of spectral scans is 12, and the signal intensity is the absorbance at each wavelength.

[0028] In the present invention, the signal intensity is the light absorbance of the resin film within a specific wavelength range, and its unit is an arbitrary unit (au). -1 ~2322cm -1 The signal intensity B is calculated by calculating the integral area defined by the line connecting the start and end points of the absorption peak (i.e., the tangents at the lowest points on both sides of the peak). -1 ~1523cm -1 The signal intensity C is calculated by calculating the integral area defined by the line connecting the start and end points of the absorption peak at 2943 cm. -1 ~2990cm -1 It is obtained by calculating the integral area defined by the line connecting the start and end points of the absorption peak.

[0029] The A / B and / or C / B values ​​of the resin film of the present invention, as determined by Fourier transform infrared spectroscopy, can be adjusted by controlling the composition of the resin film or the drying conditions of the resin film. For example, the A / B and C / B values ​​can be adjusted by using a different resin, curing agent, or curing accelerator. Drying conditions include, but are not limited to, drying temperature and drying time. A person skilled in the art of the present invention can select an appropriate composition or conditions to obtain the desired A / B and C / B values ​​based on the disclosure of the specification of the subject application and their ordinary skills.

[0030] 1.2. Components of resin film 1.2.1. Epoxy resins and cyanate resins The composition of the resin film can be adjusted as needed, provided that the A / B value determined by Fourier transform infrared spectroscopy satisfies 0.70≦A / B≦1.95. In some embodiments of the present invention, the resin film contains an epoxy resin and a cyanate resin as resin components of the resin film, or the resin component of the resin film consists essentially of an epoxy resin and a cyanate resin, or the resin component of the resin film consists essentially of an epoxy resin and a cyanate resin. The expression "the resin component of the resin film consists essentially of an epoxy resin and a cyanate resin" means that the combined amount of the epoxy resin and the cyanate resin is at least 80 wt %, more specifically at least 85 wt %, based on the total weight of the resin components of the resin film. For example, based on the total weight of the resin components of the resin film, the combined amount of epoxy resin and cyanate resin may be 85 wt%, 86 wt%, 87 wt%, 88 wt%, 89 wt%, 90 wt%, 91 wt%, 92 wt%, 94 wt%, 95 wt%, 96 wt%, 97 wt%, 98 wt%, or 99 wt%.

[0031] The epoxy resin may be an aliphatic epoxy resin having a conjugated unsaturated bond, or an aromatic epoxy resin having a conjugated unsaturated bond, with aromatic epoxy resins having a conjugated unsaturated bond being preferred. Examples of epoxy resins include, but are not limited to, bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, phenol epoxy resin (alkylphenol epoxy resin), biphenyl epoxy resin, aralkyl epoxy resin, naphthalene epoxy resin, naphthol epoxy resin, epoxide of a condensation product of a phenol having a phenolic hydroxyl group and an aromatic aldehyde, biphenyl aralkyl epoxy resin, fluorene epoxy resin, xanthene epoxy resin, dicyclopentadiene epoxy resin, and poly(triglycidyl isocyanurate). The aforementioned epoxy resins may be used alone or in any combination. In some embodiments of the present invention, the resin film comprises a naphthalene epoxy resin and a biphenyl epoxy resin.

[0032] Examples of commercially available epoxy resin products that can be used in the resin film of the present invention include, but are not limited to, BE188 available from Chang Chun Plastics, bfe170 available from Chang Chun Plastics, NC-3000 series epoxy resins available from Nippon Kayaku, jER® YX series epoxy resins available from Mitsubishi Chemical, EPICLON® HP-4032 epoxy resin available from DIC, and SE80 series available from SHIN-A T&C.

[0033] Examples of cyanate resins include, but are not limited to, bisphenol A dicyanate, bisphenol E-type cyanate resin, bisphenol F dicyanate, bisphenol S dicyanate, phenol cyanate resin, biphenyl dicyanate, biphenol dicyanate, hexafluorobisphenol 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)sulfide, bis(4-cyanatephenyl)ether, and dicyclopentadiene structure-containing phenol cyanate resin. The cyanate resins may be used alone or in any combination. In some embodiments of the present invention, the resin film comprises a bisphenol E-type cyanate resin and a phenol cyanate resin.

[0034] Examples of commercially available cyanate resin products that can be used in the resin film of the present invention include, but are not limited to, BA-230S available from LONZA Corporation, PT-S60 available from LONZA Corporation, LVT-50 available from LONZA Corporation, PT30 available from LONZA Corporation, and LECy available from LONZA Corporation, where BA-230S and LECy are bisphenol cyanate resins, and PT-S60, LVT-50, and PT30 are phenol cyanate resins.

[0035] It was found that the A value of the resin film can be adjusted by adjusting the amount of -OCN bonds contained in the cyanate resin, the B value of the resin film can be adjusted by adjusting the amount of conjugated unsaturated carbon-carbon bonds contained in the epoxy resin, and the C value of the resin film can be adjusted by adjusting the amount of methyl contained in the cyanate resin and epoxy resin. Therefore, it is possible to control the A / B and C / B values ​​of the resin film by adjusting at least the parameters mentioned above.

[0036] As long as the A / B ratio of the resin film is within a predetermined range, the amount of epoxy resin in the resin film can be adjusted as needed. For example, the amount of epoxy resin can be 2% by weight to 25% by weight based on the solid content of the resin film. For example, based on the solid content of the resin film, the amount of epoxy resin can be 2% by weight, 3% by weight, 4% by weight, 5% by weight, 6% by weight, 7% by weight, 8% by weight, 9% by weight, 10% by weight, 11% by weight, 12% by weight, 13% by weight, 14% by weight, 15% by weight, 16% by weight, 17% by weight, 18% by weight, 19% by weight, 20% by weight, 21% by weight, 22% by weight, 23% by weight, 24% by weight, or 25% by weight, or within a range between any two of the values ​​described herein. In some embodiments of the present invention, the amount of epoxy resin is 5% by weight to 18% by weight based on the solid content of the resin film.

[0037] Assuming that the A / B value of the resin film is within a predetermined range, the amount of cyanate resin in the resin film can be adjusted as needed. For example, the amount of cyanate resin can be 1 wt% to 25 wt% based on the solid content of the resin film. For example, based on the solid content of the resin film, the amount of cyanate resin can be 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt%, 21 wt%, 22 wt%, 23 wt%, 24 wt%, or 25 wt%, or within a range between any two of the values ​​described herein. In some embodiments of the present invention, the amount of cyanate resin is 1 wt% to 19 wt% based on the solid content of the resin film.

[0038] Filler In some embodiments of the present invention, the resin film further comprises a filler to adaptively improve the mechanical strength, thermal conductivity, and dimensional stability of the resin film.

[0039] Examples of suitable fillers include, but are not limited to, silica (including hollow silica, spherical silica sand, etc.), aluminum oxide, magnesium oxide, magnesium hydroxide, calcium carbonate, talc, clay, aluminum nitride, boron nitride, aluminum hydroxide, aluminum silicon carbide, silicon carbide, sodium carbonate, titanium dioxide, zinc oxide, zirconium oxide, quartz, diamond, diamond-like carbon, graphite, calcined kaolin, puriane, mica, hydrotalcite, polytetrafluoroethylene (PTFE) powder, glass beads, ceramic whiskers, carbon nanotubes, and strontium titanate. The above fillers may be used alone or in any combination.

[0040] The shape of the filler is not particularly limited. For example, the filler may have a spherical, fibrous, plate-like, granular, flake-like, or needle-like shape, but the present invention is not limited to these. Furthermore, the size of the filler is also not particularly limited. For example, in the case of a spherical or granular filler, the average particle size of the filler may be less than 10 μm, preferably 0.1 μm to 5 μm.

[0041] To improve the compatibility of the filler with other components of the resin film, the filler may be surface-modified with a coupling agent before being added to the resin film. Examples of the coupling agent include, but are not limited to, silane coupling agents, titanate coupling agents, and polysiloxanes with low degrees of polymerization.

[0042] The amount of filler can be adjusted as needed. Generally, the amount of filler may be 50% by weight to 90% by weight based on the solid content of the resin film. For example, based on the solids content of the resin film, the amount of filler can be 50% by weight, 51% by weight, 52% by weight, 53% by weight, 54% by weight, 55% by weight, 56% by weight, 57% by weight, 58% by weight, 59% by weight, 60% by weight, 61% by weight, 62% by weight, 63% by weight, 64% by weight, 65% by weight, 66% by weight, 67% by weight, 68% by weight, 69% by weight, 70% by weight, 71% by weight, 72% by weight, 73% by weight, 74% by weight, 75% by weight, 76% by weight, 77% by weight, 78% by weight, 79% by weight, 80% by weight, 81% by weight, 82% by weight, 83% by weight, 84% by weight, 85% by weight, 86% by weight, 87% by weight, 88% by weight, 89% by weight, or 90% by weight, or a range between any two of the values ​​recited herein. In a preferred embodiment of the present invention, in order to satisfy the requirement for high dimensional stability of the multilayer printed wiring board, the amount of filler is preferably 70% by weight to 88% by weight based on the solid content of the resin film. When the amount of filler is within the predetermined range, the resin film can have excellent dimensional stability, more specifically, excellent thermal expansion coefficient and warpage.

[0043] 1.2.3. Other optional ingredients The resin film of the present invention may further contain other optional components to adaptively improve the processability of the resin film during manufacturing or to improve the physicochemical properties of the resulting dielectric material. Examples of optional components include, but are not limited to, solvents, curing accelerators, elastomers, flame retardants, and additives known in the art. Examples of elastomers include, but are not limited to, polybutadiene, polyisoprene, and styrene-alkene copolymers. Examples of flame retardants include, but are not limited to, phosphorus-containing flame retardants and bromine-containing flame retardants. Examples of solvents include, but are not limited to, toluene, γ-butyrolactone, methyl ethyl ketone, cyclohexanone, butanone, acetone, xylene, methyl isobutyl ketone, N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), and N-methylpyrrolidone (NMP). Examples of accelerators include, but are not limited to, amine accelerators (DETDA-80), guanidine accelerators, and imidazole accelerators. Examples of additives known in the art include, but are not limited to, carbon black, dispersants, toughening agents, viscosity modifiers, thixotropic agents, defoamers, leveling agents, surface modifiers, stabilizers, and antioxidants. Optional components may be used alone or in any combination.

[0044] In some embodiments of the present invention, the resin film further comprises a solvent, and the amount of the solvent may be 3 wt% to 16 wt% based on the total weight of the resin film. For example, the amount of the solvent may be 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, or 16 wt%, or within a range between any two of the values ​​recited herein, based on the total weight of the resin film.

[0045] In some embodiments of the present invention, the resin film further comprises carbon black, and the amount of carbon black may be 0.1 wt% to 1 wt% based on the solid content of the resin film. For example, the amount of carbon black based on the solid content of the resin film may be 0.1 wt%, 0.15 wt%, 0.2 wt%, 0.25 wt%, 0.3 wt%, 0.35 wt%, 0.4 wt%, 0.45 wt%, 0.5 wt%, 0.55 wt%, 0.6 wt%, 0.65 wt%, 0.7 wt%, 0.75 wt%, 0.8 wt%, 0.85 wt%, 0.9 wt%, 0.95 wt%, or 1 wt%, or within a range between any two of the values ​​described herein. The use of carbon black can impart a black color to the resin film of the present invention, which is advantageous for effective shielding of wiring during the build-up process of wiring packages.

[0046] In some embodiments of the present invention, the resin film further comprises a curing accelerator to accelerate the curing reaction and lower the curing reaction temperature of the resin composition. The amount of the curing accelerator is not particularly limited. Generally, the amount of the curing accelerator may be 0.1 wt % to 3 wt % based on the solid content of the resin film. For example, based on the solids content of the resin film, the amount of cure accelerator can be 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, 1 wt%, 1.1 wt%, 1.2 wt%, 1.3 wt%, 1.4 wt%, 1.5 wt%, 1.6 wt%, 1.7 wt%, 1.8 wt%, 1.9 wt%, 2 wt%, 2.1 wt%, 2.2 wt%, 2.3 wt%, 2.4 wt%, 2.5 wt%, 2.6 wt%, 2.7 wt%, 2.8 wt%, 2.9 wt%, or 3 wt%, or a range between any two of the values ​​recited herein.

[0047] 1.3.Other characteristics of resin film The resin film of the present invention is a semi-cured film (B-stage). That is, the resin film is dry-baked so that it contains no solvent or only a small amount of solvent, and the resin component of the resin film may have undergone some oligomerization, but is not completely cured. The resin film of the present invention is provided with a uniform thickness, which is advantageous for providing a large-area dielectric material. Furthermore, the resin film of the present invention has excellent adhesion to copper foil and heat resistance. Furthermore, in a preferred embodiment in which the resin film contains a large amount of filler, the resin film can have excellent dimensional stability.

[0048] In some embodiments of the present invention, the resin film can have a thickness of 25 μm to 300 μm. For example, the resin film can have a thickness of 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm, 80 μm, 85 μm, 90 μm, 95 μm, 100 μm, 105 μm, 110 μm, 115 μm, 120 μm, 125 μm, 130 μm, 135 μm, 140 μm, 145 μm, 150 μm, 155 μm, 160 μm, 165 μm, 170 μm, 175 μm, The thickness may be 180 μm, 185 μm, 190 μm, 195 μm, 200 μm, 205 μm, 210 μm, 215 μm, 220 μm, 225 μm, 230 μm, 235 μm, 240 μm, 245 μm, 250 μm, 255 μm, 260 μm, 265 μm, 270 μm, 275 μm, 280 μm, 285 μm, 290 μm, 295 μm, or 300 μm, or within a range between any two of the values ​​described herein. The thickness can be adjusted as needed.

[0049] 1.4. Preparation of resin film The method for producing the resin film of the present invention is not particularly limited, and a person skilled in the art can produce the resin film based on the disclosure of the present specification.

[0050] For example, the resin film of the present invention can be produced by uniformly mixing the resin film raw materials, including the resin component, filler, and optional components, in a mixer, dissolving or dispersing the components in a solvent to obtain a uniform solution, uniformly coating this uniform solution on a carrier film, and drying at an appropriate drying temperature for an appropriate drying time to obtain a semi-cured resin film. The solvent can be any inert solvent that can dissolve or disperse the resin film raw materials but does not react with the raw materials. Examples of solvents are as described above.

[0051] It has been found that the degree of reaction of the components of a resin film, and therefore the A / B and C / B values, can be affected by the drying temperature and drying time. Therefore, it is possible to adjust the A / B value of a resin film by controlling the drying temperature and drying time. In some embodiments of the present invention, the drying temperature may be 80°C to 120°C. For example, the drying temperature may be 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, 115°C, or 120°C, or within a range between any two of the values ​​described herein. In some embodiments of the present invention, the drying time may be 5 minutes to 25 minutes. For example, the drying time may be 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, 10 minutes, 11 minutes, 12 minutes, 13 minutes, 14 minutes, 15 minutes, 16 minutes, 17 minutes, 18 minutes, 19 minutes, 20 minutes, 21 minutes, 22 minutes, 23 minutes, 24 minutes, or 25 minutes, or within a range between any two of the values ​​described herein.

[0052] After the preparation of the resin film of the present invention is completed, the resin film can be placed at room temperature and subjected to FTIR analysis within two days to measure its FTIR characteristics. Alternatively, if FTIR analysis cannot be performed in a timely manner, the resin film can be stored at 0°C to -40°C, then placed at room temperature to warm to room temperature, and subjected to FTIR analysis within two days.

[0053] Exemplary processes for making resin films of the present invention are described in more detail in the examples provided below.

[0054] 2. Uses of resin film The resin film of the present invention can be used as a dielectric material for printed circuit boards (PCBs). Accordingly, the present invention also provides a copper-clad laminate comprising a dielectric layer and copper foil covering the surface of the dielectric layer, the dielectric layer being formed from the resin film of the present invention. Specifically, the copper-clad laminate of the present invention can be produced by using a single resin film or a laminate of multiple resin films as the dielectric layer, overlaying copper foil on at least one outer surface of the dielectric layer, forming a multilayer body comprising the dielectric layer and the copper foil, and hot-pressing the multilayer body to obtain a metal-clad laminate.

[0055] The resin film of the present invention can also be used for sealing. Accordingly, the present invention also provides a sealing material containing the resin film. [Example]

[0056] 3. Working Example 3.1. Test Method The present invention will be described in more detail below with reference to the following embodiments. Test equipment and test method are as follows.

[0057] [Infrared Spectroscopy Test] The prepared dry resin film with a thickness of 160 μm is cut into a 5 cm × 5 cm sample. This sample is placed in a Fourier transform infrared spectrometer and measured at 650 cm -1 ~4000cm -1 The absorption spectrum was measured in the range of 2205 cm by attenuated total reflection. -1 ~2322cm -1 Signal intensity A, 1472 cm -1 ~1523cm -1 Signal strength B, 2943 cm -1 ~2990cm -1 The signal intensity C of the Fourier transform infrared spectrometer is measured. The resolution of the spectrometer is 1 cm. -1The number of spectral scans was 12, and the signal intensity was the absorbance at each wavelength (au). The calculation method was to calculate the integral area defined by the line connecting the start and end points of the peak within a specific range (the tangents at the lowest points on both sides of the peak). The machine software "PerkinElmer Spectrum Ver. 10.5.3" was used to calculate the integral area.

[0058] [Adhesion test to copper foil]. The dried resin film was placed at 85 to 120°C, and the treated surface of 1-ounce electrolytic copper foil (Chang Chun Copper Foil, grade: PLS) was subjected to a pressure of 5 to 10 kgf / cm. 2 Then, the laminate is aged in an oven at 180° C. for 3 hours to obtain a copper clad laminate (1).

[0059] This copper clad laminate (1) is placed in a chamber for a pressure cooker test, and is subjected to a temperature of 120°C and a pressure of 0.2 MPa for 48 hours to obtain a copper clad laminate (2).

[0060] Copper clad laminate (1) and copper clad laminate (2) are each cut to a size of 10 cm x 3.5 cm (MD direction x TD direction). The adhesive surface of each copper clad laminate is attached to a bonding sheet and a polypropylene sheet, and then subjected to a temperature of 185 °C and a pressure of 100 kgf / cm 2 The specimens were pressed at a pressure of 0.05 for 120 seconds, and then aged at 170°C for 1 hour. Then, the specimens were attached to a 3.5 mm thin tape that was barely etched and wet-etched to obtain specimens (1) and (2), respectively.

[0061] The tensile strength of sample (1) and sample (2) was tested in accordance with IPC-TM-650 test method 2.4.9. The tensile force was 0.7 kgf / cm. 2 If it is larger than this, mark it as "○", and the tensile strength is 0.5 to 0.7 kgf / cm 2 If the tensile strength is 0.5kgf / cm, the result is "△". 2 If it is less than this, the test result is recorded as "x".

[0062] [Glass transition temperature and thermal expansion coefficient test] The prepared resin film was placed in a 180°C oven and aged for 3 hours to obtain a cured product. This cured product was cut into 5mm x 15mm samples and analyzed using a thermomechanical analyzer (TMA) (available from TA) using the tensile weighting method. After placing the sample in the analyzer, two consecutive measurements were performed under the following test conditions: stress of 50mN, heating rate of 10°C / min, and test temperature range from room temperature to 280°C. The glass transition temperature (Tg), average linear expansion coefficient CTE1 from 50°C to 120°C, and average linear expansion coefficient CTE2 from 180°C to 240°C were recorded. The linear thermal expansion coefficient is expressed in ppm / °C. The higher the glass transition temperature of the resin film, the better its heat resistance. Furthermore, the lower the thermal expansion coefficient of the resin film, the better its dimensional stability.

[0063] [Warp test] The resulting dried resin film, 160 μm thick, is cut into a 10 cm x 25 cm sample. This sample is placed in an oven (C-SUN, model number: SMO-1B) and aged at 150°C for 4 hours. After aging, the amount of warping in the transverse direction (TD) at the edge of the sample is measured. The calculation is based on the distance from the horizontal plane to the highest point of the warp at the edge of the sample. If the warp is less than 2 cm, it is recorded as "○", if it is 2-3 cm, it is recorded as "△", and if it is 3 cm or more or the resin film is torn, it is recorded as "×". A large warp value (long warp distance) or if the resin film is torn indicates poor dimensional stability.

[0064] [Gel time test] 1 to 2 g of resin film is placed on a hot plate at 150° C. The resin film is moved using a stricle (or scraper) and the time GT until the resin film loses its fluidity is measured.

[0065] 3.2. Preparation of resin film [Example 1] Using a planetary mixer (model number: ARV-310), 4.31 wt% naphthalene-type epoxy resin (model number: EPICLON® HP-4032, available from DIC Corporation), 3.08 wt% biphenyl-type epoxy resin (model number: NC-3000, available from Nippon Kayaku Co., Ltd.), 9.67 wt% bisphenol E-type cyanate resin (model number: LECy, available from LONZA Corporation), 4.16 wt% phenol-based cyanate resin (model number: PT30, available from LONZA Corporation), 0.41 wt% amine-based curing accelerator, 0.37 wt% carbon black, and 78.00 wt% spherical silica sand filler (all solids content) were mixed and dispersed using a three-roll kneader. The solvent was added to the mixture to form a homogeneous solution. The amount of solvent was 9.04 parts by weight per 100 parts by weight of solids.

[0066] The homogeneous solution was uniformly coated onto a PET carrier film. The wet film was scraped off with a wire-wound rod and a coating rod. The wet film was then dried in an oven at 100°C for 10 minutes to obtain a semi-cured resin film. The resin film formation results were then observed.

[0067] [Example 2] A resin film was produced by repeating the production procedure of Example 1, except that the amounts of the components were adjusted to the following: 5.75 wt% naphthalene epoxy resin, 4.11 wt% biphenyl epoxy resin, 7.94 wt% bisphenol E-type cyanate resin, 3.42 wt% phenol cyanate resin, 0.41 wt% amine-based curing accelerator, 0.37 wt% carbon black, and 78.00 wt% spherical silica sand filler (all based on solids), and the solvent was 11.29 wt% per 100 wt% solids. The drying time was adjusted to 5 minutes.

[0068] [Example 3] A resin film was produced by repeating the production procedure of Example 1, except that the amounts of the components were adjusted as follows: 9.52 wt% naphthalene epoxy resin, 6.81 wt% biphenyl epoxy resin, 3.42 wt% bisphenol E-type cyanate resin, 1.47 wt% phenol cyanate resin, 0.41 wt% amine-based curing accelerator, 0.37 wt% carbon black, 78.00 wt% spherical silica sand filler (all based on solids), and 9.28 wt parts solvent per 100 wt parts solids. The drying time was adjusted to 5 minutes.

[0069] [Example 4] A resin film was produced by repeating the production procedure of Example 1, except that the amounts of the components were adjusted as follows: 7.50 wt% naphthalene epoxy resin, 5.35 wt% biphenyl epoxy resin, 10.36 wt% bisphenol E-type cyanate resin, 4.46 wt% phenol cyanate resin, 0.46 wt% amine-based curing accelerator, 0.54 wt% carbon black, 71.33 wt% spherical silica sand filler (all based on solids), and 9.95 wt parts solvent per 100 wt parts solids. The drying temperature was adjusted to 120°C.

[0070] [Example 5] A resin film was produced by repeating the production procedure of Example 1, except that the amounts of the components were adjusted to the following: 5.87 wt% naphthalene epoxy resin, 4.19 wt% biphenyl epoxy resin, 8.11 wt% bisphenol E cyanate resin, 3.49 wt% phenol cyanate resin, 0.40 wt% amine curing accelerator, 0.54 wt% carbon black, and 77.40 wt% spherical silica sand filler (all based on solids), and 12.00 wt parts solvent per 100 wt parts solids. The drying temperature was adjusted to 120°C, and the drying time was adjusted to 5 minutes.

[0071] [Example 6] A resin film was produced by repeating the production procedure of Example 1, except that the amounts of the components were adjusted as follows: 3.53 wt% naphthalene epoxy resin, 2.48 wt% biphenyl epoxy resin, 4.85 wt% bisphenol E cyanate resin, 2.09 wt% phenol cyanate resin, 0.20 wt% amine curing accelerator, 0.54 wt% carbon black, 86.31 wt% spherical silica sand filler (all based on solids), and 15.15 wt parts solvent per 100 wt parts solids. The drying temperature was adjusted to 120°C.

[0072] [Example 7] A resin film was produced by repeating the production procedure of Example 1, except that the amounts of the components were adjusted as follows: 10.21 wt% naphthalene epoxy resin, 7.28 wt% biphenyl epoxy resin, 14.10 wt% bisphenol E cyanate resin, 6.07 wt% phenol cyanate resin, 0.40 wt% amine curing accelerator, 0.54 wt% carbon black, 61.40 wt% spherical silica sand filler (all based on solids), and 5.70 wt parts solvent per 100 wt parts solids. The drying temperature was adjusted to 120°C, and the drying time was adjusted to 25 minutes.

[0073] [Example 8] A resin film was produced by repeating the production procedure of Example 1, except that the amounts of the components were adjusted as follows: 8.82 wt% naphthalene epoxy resin, 6.30 wt% biphenyl epoxy resin, 12.19 wt% bisphenol E-type cyanate resin, 5.25 wt% phenol cyanate resin, 0.55 wt% amine-based curing accelerator, 0.54 wt% carbon black, and 66.35 wt% spherical silica sand filler (all based on solids), with 9.09 wt parts solvent per 100 wt parts solids. The drying temperature was adjusted to 120°C, and the drying time was adjusted to 5 minutes.

[0074] [Comparative Example 1] A resin film was produced by repeating the production procedure of Example 1, except that the amounts of the components were adjusted as follows: 2.60 wt% naphthalene epoxy resin, 1.87 wt% biphenyl epoxy resin, 11.71 wt% bisphenol E-type cyanate resin, 5.04 wt% phenol cyanate resin, 0.41 wt% amine-based curing accelerator, 0.37 wt% carbon black, 78.00 wt% spherical silica sand filler (all based on solid content), and 10.44 wt% solvent per 100 wt% solid content.

[0075] Comparative Example 2 A resin film was produced by repeating the production procedure of Example 1, except that the amounts of the components were adjusted as follows: 10.75 wt% naphthalene epoxy resin, 7.71 wt% biphenyl epoxy resin, 1.93 wt% bisphenol E cyanate resin, 0.83 wt% phenol cyanate resin, 0.41 wt% amine curing accelerator, 0.37 wt% carbon black, 78.00 wt% spherical silica sand filler (all based on solids), and 12.73 wt% solvent per 100 wt% solids. The drying time was also adjusted to 5 minutes.

[0076] Comparative Example 3 A resin film was produced by repeating the production procedure of Example 1, except that the amounts of the components were adjusted as follows: 2.15 wt% naphthalene epoxy resin, 1.53 wt% biphenyl epoxy resin, 2.97 wt% bisphenol E cyanate resin, 1.28 wt% phenol cyanate resin, 0.20 wt% amine curing accelerator, 0.54 wt% carbon black, and 91.33 wt% spherical silica sand filler (all based on solids), with 17.15 wt parts solvent per 100 wt parts solids. The drying temperature was adjusted to 120°C, and the drying time was adjusted to 5 minutes.

[0077] Comparative Example 4 A resin film was produced by repeating the production procedure of Example 1, except that the amounts of the components were adjusted as follows: 5.88 wt% naphthalene epoxy resin, 4.19 wt% biphenyl epoxy resin, 8.11 wt% bisphenol E cyanate resin, 3.49 wt% phenol cyanate resin, 0.40 wt% amine curing accelerator, 0.54 wt% carbon black, and 77.39 wt% spherical silica sand filler (all based on solids), with 11.58 wt parts solvent per 100 wt parts solids. The drying temperature was adjusted to 140°C, and the drying time was adjusted to 5 minutes.

[0078] The molding results of Examples 1 to 8 and Comparative Examples 1 to 4 are shown in Table 1-1. TIFF0007821765000001.tif42164

[0079] As shown in Table 1-1, the molding results of the resin films of Examples 1 to 8 were good. On the other hand, the molding results of Comparative Examples 2 to 4 were either destroyed or poor.

[0080] 3.3. Testing of resin films The resin films of Examples 1 to 8 and Comparative Examples 1 to 4 were tested for properties such as infrared spectroscopic signal intensity, adhesion to copper foil, glass transition temperature, thermal expansion coefficient, warpage, and gel time according to the test methods described above, and the results are shown in Tables 2-1 and 2-2.

[0081] TIFF0007821765000002.tif116164

[0082] TIFF0007821765000003.tif120164*NA means that the fluidity is extremely poor and a gel time test cannot be performed.

[0083] As shown in Tables 2-1 and 2-2, the resin films of Examples 1 to 8 of the present invention have excellent adhesion to copper foil and high glass transition temperatures, indicating excellent heat resistance. In contrast, Comparative Example 1 exhibits poor adhesion to copper foil when the A / B value is higher than 1.95, while Comparative Examples 2 to 4 exhibit poor adhesion to copper foil when the A / B value is lower than 0.70, indicating low glass transition temperatures and poor heat resistance. In particular, a comparison between Example 5 and Comparative Example 4 reveals that even if the raw materials for the resin film are the same, adjusting the drying conditions so that the A / B value is less than 0.70 does not result in the effects of the present invention. This demonstrates that the technical feature related to the A / B value is one of the special technical features for achieving the effects of the present invention. Furthermore, a comparison between Examples 1 to 6 and Examples 7 and 8 shows that, on the premise that the A / B value satisfies 0.70≦A / B≦1.95, when the amount of filler is adjusted to 70 to 88 wt %, the thermal expansion coefficient can be further improved and the warpage of the resin film can be reduced, i.e., the dimensional stability can be further improved.

[0084] The above embodiments illustrate the principles and effects of the present invention and demonstrate its inventive features. Those skilled in the art can make various modifications and substitutions based on the disclosure and suggestions of the present invention described without departing from the principles thereof. Therefore, the protection scope of the present invention is as defined in the appended claims.

Claims

1. A resin film containing an epoxy resin and a cyanate resin, When the resin film is characterized by Fourier transform infrared spectroscopy (FTIR), the Fourier transform infrared spectrum of the resin film has a peak at 2205 cm －１ ~2322cm －１ Signal intensity A and 1472 cm －１ ~1523cm －１ and 0.70≦A / B≦1.95, The resin film has a thickness of 30 μm to 300 μm, the epoxy resin is an epoxy resin having a conjugated unsaturated bond, A resin film, wherein the amount of the epoxy resin is 6% by weight to 25% by weight based on the solid content of the resin film.

2. The Fourier transform infrared spectroscopy analysis is performed by placing a resin film on a Fourier transform infrared spectroscopy analyzer and measuring the intensity of the resin film at 650 cm －１ ~4000cm －１ and measuring the signal intensities A and B using the attenuated total reflection method. The resolution of the Fourier transform infrared spectrometer is 1 cm －１ The resin film according to claim 1, wherein the number of scans of the spectrum is 12, and the signal intensity is absorbance at each wavelength.

3. The Fourier transform infrared spectrum of the resin film is 2943 cm －１ ~2990cm －１ and 0.05≦C / B≦0.

4.

4. The resin film according to claim 1 , wherein the epoxy resin is an aromatic epoxy resin.

5. 2. The resin film according to claim 1, wherein the epoxy resin is selected from the group consisting of bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, phenol epoxy resins, biphenyl epoxy resins, aralkyl epoxy resins, naphthalene epoxy resins, naphthol epoxy resins, epoxides of condensates of phenols having a phenolic hydroxyl group with aromatic aldehydes, biphenyl aralkyl epoxy resins, fluorene epoxy resins, xanthene epoxy resins, dicyclopentadiene epoxy resins, poly(triglycidyl isocyanurate), and combinations thereof.

6. 2. The resin film according to claim 1, wherein the cyanate resin is selected from the group consisting of bisphenol A dicyanate, bisphenol E-type cyanate resin, bisphenol F dicyanate, bisphenol S dicyanate, phenol cyanate resin, biphenyl dicyanate, biphenol dicyanate, hexafluorobisphenol 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)sulfide, bis(4-cyanatephenyl)ether, phenol cyanate resins containing a dicyclopentadiene structure, and combinations thereof.

7. 2. The resin film according to claim 1, further comprising a filler, the amount of the filler being 70% by weight to 88% by weight based on the solid content of the resin film.

8. 8. The resin film according to claim 7, wherein the filler is selected from the group consisting of silica, aluminum oxide, magnesium oxide, magnesium hydroxide, calcium carbonate, talc, clay, aluminum nitride, boron nitride, aluminum hydroxide, aluminum silicon carbide, silicon carbide, sodium carbonate, titanium dioxide, zinc oxide, zirconium oxide, quartz, diamond, diamond-like carbon, graphite, calcined kaolin, puriane, mica, hydrotalcite, polytetrafluoroethylene (PTFE) powder, glass beads, ceramic whiskers, carbon nanotubes, strontium titanate, and combinations thereof.

9. The resin film according to claim 1 , further comprising carbon black.

10. The resin film according to claim 1 , further comprising a curing accelerator selected from the group consisting of an amine-based curing accelerator, a guanidine-based curing accelerator, an imidazole-based curing accelerator, and combinations thereof.

11. A copper-clad laminate comprising a dielectric layer and a copper foil covering a surface of the dielectric layer, wherein the dielectric layer is provided from the resin film according to any one of claims 1 to 10.

12. An encapsulating material comprising the resin film according to any one of claims 1 to 10.

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