A resin composition, a resin adhesive film, and applications thereof

Abstract

The present application provides a resin composition, a resin adhesive film and application thereof. The resin composition comprises the following components by weight: (A) thermoplastic polyphenyl ether, 30-55 parts; (B) low molecular weight polyolefin resin, 10-35 parts; (C) high tensile strength polyolefin resin, 20-50 parts, wherein the tensile strength of the high tensile strength polyolefin resin is greater than or equal to 20 MPa. The present application designs the specific composition of the resin composition, and prepares the resin composition with excellent performance, and further prepares the resin adhesive film with ultra-thin thickness, which can match the high-frequency substrate, can withstand the high-temperature pressing conditions of the high-frequency substrate, and is suitable for processing the thick copper product of the high-frequency carbon-hydrogen substrate.

Description

Technical Field

[0001] This invention belongs to the field of electronic materials technology, specifically relating to a resin composition, a resin film and its application, and more specifically to a resin composition, a resin film, and a metal foil laminate and a printed circuit board containing the resin. Background Technology

[0002] As printed circuit boards (PCBs) continue to evolve towards higher density and multilayer designs, the current density requirements of various PCB designs are increasing, leading to greater heat generation. On the other hand, with the rapid development of modern communication technologies, circuit materials are increasingly used at higher frequencies, resulting in higher operating frequencies and greater heat generation in electronic devices. These two factors drive a sharp rise in the operating temperature of PCBs. If the accumulated heat cannot be dissipated in time, the operating temperature of the equipment will rise, eventually causing a decline in the electrical performance of components or even damage, severely impairing the lifespan and reliability of the equipment.

[0003] Against this backdrop, PCB manufacturers have begun to focus on thick copper laminate products. Thick copper PCBs with a copper thickness of 3 oz or more are increasingly used. However, with the advent of the 5G communication era, the requirements for high-speed transmission and processing of large amounts of information on circuit boards are gradually increasing. PCB manufacturers are no longer satisfied with FR-4 level thick copper products and have begun to actively seek high-frequency hydrocarbon thick copper laminates.

[0004] However, unlike traditional FR-4 thick copper products, high-frequency hydrocarbon thick copper laminates face different technical challenges. Typically, the peel strength of the substrate is related to the roughness of the copper foil; generally, using high-roughness copper foil yields higher peel strength. However, this rule changes for thick copper.

[0005] Thick copper typically refers to copper foil with a thickness of 3 oz or more. This type of copper foil is characterized by high roughness and long copper teeth. Hydrocarbon systems are characterized by high filler content and low resin flowability. When using thick copper and hydrocarbon prepreg laminates, the resin cannot flow properly, and the copper teeth cannot fully embed into the substrate. This results in poor peel strength for hydrocarbon-laminated thick copper clad laminates, making them difficult to apply.

[0006] CN116144209A discloses a method for preparing coated copper foil. By pre-coating a 5-10 μm thick, highly peel-resistant resin layer onto the copper foil, the adhesion between the copper foil and the substrate can be significantly improved. However, this process cannot be used to coat thick copper with a single resin layer because the rigidity of the copper foil increases with its thickness. Copper with a thickness of 3 oz or more has very poor flexibility, making automated coating production impossible using a coating machine.

[0007] Therefore, how to provide a resin film suitable for bonding thick copper to high-frequency hydrocarbon substrates has become an urgent technical problem to be solved. Summary of the Invention

[0008] To address the shortcomings of existing technologies, the present invention aims to provide a resin composition, a resin film, and their applications, and more specifically, to provide a resin composition, a resin film, and a metal-clad laminate and a printed circuit board comprising the resin. The present invention designs the specific composition of the resin composition by using a combination of thermoplastic polyphenylene ether, low molecular weight polyolefin resin, and high tensile strength polyolefin resin to prepare a resin composition with excellent performance. This allows for the preparation of a resin film with ultra-thin thickness, compatibility with high-frequency substrates, ability to withstand the high-temperature pressing conditions of high-frequency substrates, and suitability for processing thick copper products on high-frequency hydrocarbon substrates.

[0009] To achieve this objective, the present invention adopts the following technical solution:

[0010] In a first aspect, the present invention provides a resin composition comprising the following components in parts by weight:

[0011] (A) Thermoplastic polyphenylene ether, 30-55 parts;

[0012] (B) Low molecular weight polyolefin resin, 10-35 parts;

[0013] (C) High tensile strength polyolefin resin, 20-50 parts, wherein the tensile strength of the high tensile strength polyolefin resin is ≥20MPa.

[0014] Based on the problems existing in the prior art, the purpose of this invention is to provide a resin film with high tensile strength for use in stacking materials, ultra-thin thickness to reduce the impact on the dielectric constant of the substrate, dielectric loss matching that of high-frequency substrates, ability to withstand high-temperature pressing conditions of high-frequency substrates, high peel strength and good heat resistance of the final pressed thick copper substrate, and no color difference between the thick copper substrate and the original substrate, suitable for processing thick copper products on high-frequency hydrocarbon substrates.

[0015] Based on this, the present invention designs the specific composition of the resin composition to prepare a resin composition with excellent performance, and then prepares a resin film with excellent performance.

[0016] In this invention, the inventors discovered that component (A), thermoplastic polyphenylene ether, can improve the high-temperature pressing resistance of resin films. The curing temperature of high-frequency substrates exceeds that of ordinary FR-4 resin systems, typically above 240°C. Insufficient heat resistance of the resin itself leads to functional group breakage during curing, releasing small molecules and thus reducing peel resistance. Therefore, the resin film needs to possess heat resistance sufficient to withstand the curing temperature of the high-frequency substrate.

[0017] The inventors discovered that when the proportion of thermoplastic polyphenylene ether (A) exceeds 55 parts by weight, the resin film exhibits poor strength and is prone to breakage. When the proportion of thermoplastic polyphenylene ether is less than 30 parts by weight, the resin film has lower peel resistance and higher tackiness. When the proportion of thermoplastic polyphenylene ether is between 30 and 50 parts by weight, the prepreg film exhibits better strength and peel strength, lower tackiness, and is easier to use.

[0018] The inventors discovered that the low molecular weight polyolefin resin in component (B) can improve the flowability of the resin film and its heat resistance after curing. Adding a low molecular weight olefin resin to the resin composition can lower the softening point of the resin composition, resulting in better flowability during pressing, allowing for more complete encapsulation of the copper teeth and improved peel strength; it can also increase the crosslinking density of the cured resin composition, improve the degree of curing, and enhance heat resistance.

[0019] The inventors discovered that when the proportion of low molecular weight polyolefin resin (component B) exceeds 35 parts by weight, the resin film exhibits high viscosity, making it difficult to separate from the carrier film. When the proportion of low molecular weight polyolefin resin is less than 10 parts by weight, the resin film has poor flowability, resulting in lower peel resistance when laminated with a thick copper hydrocarbon substrate, and lower crosslinking density after curing. When the proportion of low molecular weight polyolefin resin is between 10 and 35 parts by weight, the laminated thick copper substrate exhibits better peel resistance and heat resistance, and lower viscosity, making it easier to use.

[0020] The inventors discovered that when the resin composition contains only low-molecular-weight olefin resin, the coated resin composition exhibits poor film-forming properties. After removing the coating carrier, the resin composition often crumbles directly, and the thinner the coated resin film, the weaker its strength. Through research and experimentation, the inventors found that adding a high-tensile-strength polyolefin resin (with a tensile strength ≥20 MPa) to the formulation significantly improves the film-forming properties and strength of the resin composition, with the improvement being greater for higher tensile strength. The inventors further discovered that adding a high-tensile-strength polyolefin resin (with a tensile strength ≥20 MPa) to the formulation can improve the molding properties and strength of the coated resin film, achieving good film-forming properties and strength even at thicknesses of 10–25 μm, thus meeting the demand for thinner resin films.

[0021] The inventors discovered that when the proportion of high-tensile-strength polyolefin resin (C) is less than 20 parts by weight, the strength of the resin film is poor. When the proportion of high-tensile-strength polyolefin resin exceeds 50 parts by weight, the softening point of the resin film is high, making it difficult for the resin to soften and for the copper teeth to fully interlock with the resin, resulting in poorer peel resistance. When the proportion of high-tensile-strength polyolefin resin is between 20 and 50 parts by weight, the strength of the resin film is good, the coated surface is good, and the laminated board has good peel resistance.

[0022] In this invention, the weight parts of component (A) thermoplastic polyphenylene ether in the resin composition can be 30 parts, 33 parts, 36 parts, 39 parts, 42 parts, 45 parts, 47 parts, 50 parts, 52 parts or 55 parts, etc.

[0023] In the resin composition, the weight parts of component (B) low molecular weight polyolefin resin can be 10 parts, 12 parts, 15 parts, 18 parts, 20 parts, 22 parts, 24 parts, 27 parts, 30 parts, 33 parts or 35 parts, etc.

[0024] In the resin composition, the weight parts of component (C) high tensile strength polyolefin resin can be 20 parts, 22 parts, 25 parts, 27 parts, 30 parts, 33 parts, 36 parts, 40 parts, 42 parts, 44 parts, 46 parts or 50 parts, etc., and the tensile strength of the high tensile strength polyolefin resin is ≥20MPa, for example, it can be 20MPa, 21MPa, 22MPa, 23MPa, 24MPa, 25MPa, 26MPa, 27MPa, 28MPa, 29MPa or 30MPa, etc.

[0025] The tensile strength test method described in this invention uses the ASTM D412 tensile test.

[0026] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. The purpose and beneficial effects of the present invention can be better achieved and realized through the following preferred technical solutions.

[0027] It should be noted that the thermoplastic polyphenylene ether mentioned refers to polyphenylene ether that does not contain unsaturated functional groups. Unsaturated functional groups are groups in a molecule that contain unsaturated chemical bonds, typically double or triple bonds. For example, unsaturated functional groups include, but are not limited to, any one or a combination of at least two of vinyl, styrene, or methacrylate groups. The inventors have found that when using thermoplastic polyphenylene ether without unsaturated functional groups as the main resin, the coated resin composition, when combined with a high-frequency substrate, exhibits good peel resistance after high-temperature pressing, without any decrease in peel resistance, and also demonstrates good heat resistance, preventing delamination and blistering after tin dipping.

[0028] Preferably, the thermoplastic polyphenylene ether resin comprises the following structural units:

[0029]

[0030] R1, R2, R3, and R4 are each independently selected from hydrogen, halogen atoms (e.g., F, Cl, Br, or I), C1-C7 (C1, C2, C3, C4, C5, C6, or C7) alkyl, C1-C7 (C1, C2, C3, C4, C5, C6, or C7) haloalkyl, C1-C7 (C1, C2, C3, C4, C5, C6, or C7) aminoalkyl, C1-C7 (C1, C2, C3, C4, C5, C6, or C7) alkoxy, C6-C10 (C6 or C10, etc.) aryl, or C6-C10 (C6, C7, C8, C9, or C10) aryloxy.

[0031] Preferably, the thermoplastic polyphenylene ether is selected from poly(2,6-dimethyl-1,4-phenylene) ether, poly(2,3,6-trimethyl-1,4-phenylene) ether, poly(2,6-diethyl-1,4-phenylene) ether, poly(2,6-dipropyl-1,4-phenylene) ether, poly(2-methyl-6-allyl-1,4-phenylene) ether, poly(di-tert-butyl-dimethoxy-1,4-phenylene) ether, poly(2,6-dichloromethyl-1,4-phenylene) ether, etc. The poly(2,6-dibromomethyl-1,4-phenylene) ether, poly(2,6-di(2-chloroethyl)-1,4-phenylene) ether, poly(2,6-dimethyl-1,4-phenylene) ether, poly(2,6-dichloro-1,4-phenylene) ether, poly(2,6-dichloro-1,4-phenylene) ether, poly(2,6-diphenyl-1,4-phenylene) ether, and poly(2,5-dimethyl-1,4-phenylene) ether, or any one or at least two combinations thereof.

[0032] Specific examples of commercially available thermoplastic polyphenylene oxides include, but are not limited to: Blendex HPP820 manufactured by US-based Kotex Corporation, Noryl 640-111 and SA90 manufactured by SABIC Corporation, and SQP40 manufactured by Shandong Shengquan Company.

[0033] As a preferred embodiment of the present invention, the number average molecular weight (Mn) of the low molecular weight polyolefin resin is ≤10000 g / mol, for example, it can be 1000 g / mol, 2000 g / mol, 3000 g / mol, 4000 g / mol, 5000 g / mol, 6000 g / mol, 7000 g / mol, 8000 g / mol, 9000 g / mol or 10000 g / mol, etc.

[0034] In this invention, the molecular weight of each polymer is determined according to GB / T 21863-2008, and the weight-average molecular weight is determined by gel permeation chromatography based on polystyrene calibration.

[0035] Preferably, the low molecular weight polyolefin resin contains ≥65% by weight of butadiene units added at the 1,2 position, for example, 65%, 66%, 68%, 70%, 72%, 75%, 77%, 78%, 80%, 81%, 84%, 86%, 88%, or 90%.

[0036] In this invention, if the number average molecular weight of the low molecular weight polyolefin resin is too high, the fluidity of the resin film will be poor, and it will not be able to flow sufficiently to wrap the copper teeth during the pressing process, thus failing to improve the peel strength; if the weight ratio of butadiene units added at the 1,2 position in the low molecular weight polyolefin resin is too low, the crosslinking density after curing will be small, resulting in insufficient heat resistance and failing to meet the application requirements.

[0037] Preferably, the low molecular weight olefin resin is selected from any one or a combination of at least two of polybutadiene resins with unsaturated double bonds, modified polybutadiene resins with unsaturated double bonds, or polybutadiene copolymer resins with unsaturated double bonds.

[0038] Preferably, the polybutadiene resin with unsaturated double bonds includes 1,2-polybutadiene resin.

[0039] Preferably, the modified polybutadiene resin with unsaturated double bonds is selected from any one or a combination of at least two of maleic anhydride-modified polybutadiene resin, acrylate-modified polybutadiene resin, epoxy-modified polybutadiene resin, amino-modified polybutadiene resin, carboxyl-terminated polybutadiene resin, and hydroxyl-terminated polybutadiene resin.

[0040] Preferably, the polybutadiene copolymer resin with unsaturated double bonds is selected from any one or a combination of at least two of polybutadiene-styrene copolymer resin, polybutadiene-styrene-divinylbenzene graft copolymer resin, maleic anhydride modified styrene-butadiene copolymer resin, and acrylate modified styrene-butadiene copolymer resin.

[0041] Specific examples of commercially available low molecular weight polyolefin resins include, but are not limited to: B1000, B2000, B3000, JP200, and TE2000 manufactured by Nippon Soda Corporation, and Ricon 100, Ricon 181, Ricon 154, and Ricon 130MA8 manufactured by Clayville Corporation of the United States.

[0042] As a preferred embodiment of the present invention, the high tensile strength polyolefin resin is selected from any one or a combination of at least two of the following: elastomeric block copolymers, ethylene propylene rubber, polybutadiene rubber, and styrene-butadiene rubber.

[0043] Preferably, the elastomeric block copolymer is selected from any one or a combination of at least two of the following: styrene-butadiene diblock copolymer, styrene-butadiene-styrene triblock copolymer, styrene-(ethylene-butene)-styrene triblock copolymer, styrene-isoprene diblock copolymer, styrene-isoprene-styrene triblock copolymer, styrene-(ethylene-propylene)-styrene triblock copolymer, and styrene-(ethylene-butene) diblock copolymer.

[0044] Specific examples of high tensile strength polyolefin resins include, but are not limited to: Kraton D1101, Kraton D1152, Kraton D1184, and Kraton D1192 manufactured by Kraton Corporation of the United States, and JSR RB810, JSRRB820, and JSR RB830 manufactured by Japan Synthetic Rubber Co., Ltd.

[0045] As a preferred embodiment of the present invention, the resin composition further includes a flame retardant.

[0046] Preferably, the flame retardant is selected from bromine-containing flame retardants and / or phosphorus-containing flame retardants.

[0047] Preferably, the brominated flame retardant is any one or a combination of at least two of the following: decabromodiphenyl ether, brominated polystyrene, brominated polycarbonate, decabromodiphenyl ethane, or ethylenebistetrabromophthalimide.

[0048] Preferably, the phosphorus-based flame retardant is selected from any one or a combination of at least two of the following: tris(2,6-dimethylphenyl)phosphine, triphenyl phosphate, bisphenol A bis(diphenyl phosphate), poly(di(phenoxy)aphosphazene), resorcinol bis[bis(2,6-dimethylphenyl)phosphate], 2,6-bis(2,6-dimethylphenyl)phosphinobenzene, 9,10-dihydro-9-oxa-10-phosphenanthrene-10-oxide, 10-(2,5-dihydroxyphenyl)-9,10-dihydro-9-oxa-10-phosphenanthrene-10-oxide, and 10-phenyl-9,10-dihydro-9-oxa-10-phosphenanthrene-10-oxide.

[0049] Examples of commercially available halogen-free flame retardants include, but are not limited to: PX200 and PX202 manufactured by Daihachi Corporation of Japan, OP935 manufactured by Klein GmbH of Germany, SPB-100 and SPV-100 manufactured by Otsuka Chemical Co., Ltd. of Japan, and XP-7866 manufactured by Albemarle Corporation of the United States.

[0050] The inclusion of flame retardants in the resin film of the present invention is determined by the need for flame retardancy, so that the resin film or the high-frequency hydrocarbon substrate pressed with the resin film has flame retardant properties and meets the UL 94V-0 requirements.

[0051] In this invention, there is no particular limitation on the amount of flame retardant added as needed. The consideration is to maintain the dielectric properties, heat resistance, and peel strength of the cured product. Based on 100 parts by weight of components (A), (B), and (C), the weight of the flame retardant is 0 to 25 parts (e.g., 0, 0.5, 1, 2, 5, 7, 10, 13, 15, 18, 20, 22, 24, or 25 parts, etc.), more preferably 10 to 20 parts.

[0052] Preferably, the resin composition further includes a free radical initiator.

[0053] Preferably, the free radical initiator is selected from organic peroxide free radical initiators and / or carbon-based free radical initiators.

[0054] Preferably, the organic peroxide radical initiator is selected from di-tert-butyl peroxide, dilauroyl peroxide, benzoyl peroxide, cumyl peroxide, tert-pentyl peroxide, tert-butyl peroxide, tert-butyl peroxide, tert-butyl isobutyrate, tert-butyl peroxide-3,5,5-trimethylhexanoate, tert-butyl peroxide, 1,1-di-tert-butyl peroxide-3,5,5-trimethylcyclohexane, 1,1-di-tert-butyl peroxide-cyclohexane, 2,2-bis(tert-butyl peroxide)butane, bis(4-tert-butylcyclohexane) Hexyl) peroxydicarbonate, dihexadecanyl peroxydicarbonate, ditetradecyl peroxydicarbonate, ditert-pentyl peroxide, dicumyl peroxide, bis(tert-butylperoxyisopropyl)benzene, 2,5-dimethyl-2,5-ditert-butylperoxyhexane, 2,5-dimethyl-2,5-ditert-butylperoxyisopropylbenzene, dicumyl peroxide, tert-butylperoxycarbonate-2-ethylhexyl, 4,4-di(tert-butylperoxy)valerate, methyl ethyl ketone peroxide or cyclohexane peroxide, or a mixture of at least two of these.

[0055] Preferably, the carbon-based free radical initiator is selected from any one or a combination of at least two of 2,3-dimethyl-2,3-diphenylbutane, 2,3-dimethyl-2,3-di(4-methylphenyl)butane, 2,3-dimethyl-2,3-di(4-isopropylphenyl)butane, and 3,4-dimethyl-3,4-diphenylhexane.

[0056] In this invention, there is no specific limitation on the amount of additives. Based on 100 parts by weight of components (A), (B), and (C), the free radical initiator is 0.1 to 5 parts by weight (e.g., 0.1, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, or 5 parts, etc.).

[0057] The resin composition of the present invention may also contain additives introduced to solve certain problems, including any one or a combination of at least two of crosslinking agents, coupling agents, leveling agents, defoamers, antioxidants, heat stabilizers, antistatic agents, ultraviolet absorbers, pigments, colorants or lubricants.

[0058] It should be noted that the present invention does not impose any special restrictions on the specific selection of crosslinking agents, coupling agents, leveling agents, defoamers, antioxidants, heat stabilizers, antistatic agents, ultraviolet absorbers, pigments, colorants, and lubricants, and all of the above-mentioned additives commonly used in the art are applicable.

[0059] In this invention, the amount of additive is not specifically limited. Based on 100 parts by weight of components (A), (B), and (C), the amount of additive is 0.1 to 8 parts by weight (e.g., 0.1, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, or 8 parts, etc.), more preferably 0.1 to 5 parts, and even more preferably 0.1 to 3 parts.

[0060] In this invention, there are no special limitations on the preparation method of the resin composition; commonly used preparation methods in the art are applicable, including but not limited to:

[0061] The resin composition is obtained by uniformly mixing the components of the resin composition with the solvent.

[0062] In this invention, there are no special restrictions on the specific selection of solvents. Solvents commonly used in the art are applicable, including but not limited to: aromatic hydrocarbon solvents such as toluene, xylene, and mesitylene, or ketone solvents such as acetone, butanone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone.

[0063] Similarly, in this invention, there are no special restrictions on the specific amount of solvent used. Commonly used solvent amounts in the art are applicable, including but not limited to: 10%, 15%, 20%, 25%, 30%, 40%, etc.

[0064] In a second aspect, the present invention provides a resin film obtained by coating a release material with a resin composition as described in the first aspect.

[0065] In this invention, there are no special limitations on the preparation method of the resin film; commonly used preparation methods in the art are applicable, including but not limited to:

[0066] The resin composition is coated onto the surface of a release film, dried, and the solvent is removed before the release film is removed to obtain the resin film.

[0067] Preferably, the drying temperature is 90 to 180°C, such as 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, or 180°C.

[0068] Preferably, the thickness of the resin film is 10-25 μm (e.g., it can be 10 μm, 13 μm, 15 μm, 17 μm, 18 μm, 20 μm, 23 μm or 25 μm, etc.), and more preferably 15-20 μm.

[0069] The inventors discovered that when the thickness of the resin film is <10μm, its strength is relatively poor and it is easy to tear when separating from the release film; when the thickness of the resin film is >25μm, its performance is very different from that of the high-frequency substrate, with significant differences in Dk, CTE, thermal conductivity and other indicators, which will greatly affect the performance of the substrate. The thinner the metal foil laminate, the greater the impact of the resin film thickness on the performance of the metal foil laminate.

[0070] Thirdly, the present invention provides a metal foil laminate, the metal foil laminate comprising a copper foil and at least one resin film as described in the second aspect;

[0071] In this invention, the resin film serves as an adhesive layer, which is located between two metal foils. The structure consists of a metal foil + one or more resin films + a metal foil.

[0072] Preferably, the metal foil laminate further includes one or more prepreg sheets, with a resin film located between the metal foil and the prepreg sheets, forming a structure of metal foil + resin film + one or more prepreg sheets + resin film + metal foil, used to improve the adhesion between the metal foil and the prepreg sheets.

[0073] As a preferred embodiment of the present invention, the copper foil is a thick copper foil with a thickness of ≥3OZ (105μm), and the thickness of the thick copper foil can be 3OZ, 4OZ, 5OZ or 6OZ, etc.

[0074] In this invention, the method for preparing the metal foil-coated laminate includes the following steps:

[0075] After copper foil, resin film, and optional prepreg are stacked in the required order, they are placed in the press layer and pressed to form a metal foil laminate.

[0076] Preferably, the lamination process is vacuum lamination, which can be achieved using a vacuum laminator. The lamination time is 60–150 min, for example, 60 min, 70 min, 80 min, 90 min, 100 min, 110 min, 120 min, 130 min, 140 min, 150 min, etc.; the lamination temperature is 200–265℃, for example, 200℃, 210℃, 220℃, 230℃, 240℃, 245℃, 250℃, 255℃, 260℃, 265℃, etc.; the lamination pressure is 20–60 kg / cm². 2 For example, 20kg / cm 2 25kg / cm 2 30kg / cm 2 35kg / cm 2 40kg / cm 2 45kg / cm 2 50kg / cm 2 55kg / cm 2 Or 60kg / cm 2 wait.

[0077] In this invention, the specific parameters of the lamination time, temperature and pressure are determined based on the prepreg used. Depending on the different formulations, the lamination parameters can be flexibly adjusted within a limited range.

[0078] Fourthly, the present invention provides a printed circuit board, the printed circuit board comprising the resin film described in the second aspect;

[0079] Preferably, the printed circuit board is a high-frequency substrate.

[0080] Compared with the prior art, the present invention has the following beneficial effects:

[0081] (1) By designing the specific composition of the resin composition and controlling the amount of thermoplastic polyphenylene ether, low molecular weight polyolefin resin and high tensile strength polyolefin resin within a specific range, the present invention has prepared a resin composition with excellent performance, and then prepared a resin film with ultra-thin thickness, which can match high frequency substrates, can withstand the high temperature pressing conditions of high frequency substrates, and is suitable for processing thick copper products with high frequency hydrocarbon substrates.

[0082] (2) The resin film provided by the present invention can be coated on a carrier such as release film or release paper. When used, it is peeled off from the carrier and stacked between copper foils or between copper foil and prepreg, thereby improving the peel strength. In the prior art, the coating process of coated copper foil can only be used for copper foil of 2OZ and below, and cannot be applied to thick copper of 3OZ and above. This is because the thicker the copper foil, the greater its rigidity and the worse its flexibility, and it is impossible to achieve continuous mass production through the coating process. The resin film provided by the present invention can be applied to thick copper of 3OZ and above, and its peel strength is high.

[0083] (3) The resin film provided by the present invention has a great advantage in terms of storage cost. Compared with coated copper foil, its material cost only includes resin film and release film as carrier. Coated copper foil is made by coating cheap resin onto expensive copper foil. When the coated copper foil needs to be scrapped due to expiration or copper foil oxidation, the loss is large.

[0084] (4) The resin film provided by the present invention has an ultra-thin thickness (10-25 μm), which minimizes the impact of the resin film on the performance of the substrate. In particular, it has little impact on the performance of the substrate for boards with a thickness of more than 0.5 mm. Under the premise of meeting the thickness requirement, the resin film has a very uniform appearance and good strength and operability.

[0085] (5) The resin film provided by the present invention has dielectric loss matching that of high frequency substrate, high adhesion peel strength of thick copper, good heat resistance, no delamination or bubbling when immersed in tin at 288°C for 5 minutes, and the color before and after curing is similar to that of hydrocarbon substrate, without color difference, which facilitates product upgrades and is very suitable for making high frequency hydrocarbon thick copper products. Detailed Implementation

[0086] To facilitate understanding of the present invention, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of the invention.

[0087] The sources of some materials used in the examples and comparative examples are shown in Table 1 below:

[0088] Table 1

[0089]

[0090]

[0091] Examples 1-17 and Comparative Examples 1-8, 10-12, and 14

[0092] Examples 1-17 and Comparative Examples 1-8, 10-12, and 14 respectively provide a resin composition, a resin film, and a copper-clad laminate. The specific composition of the resin composition is shown in Tables 2-5 below:

[0093] The resin composition is prepared as follows:

[0094] Each component of the resin composition was added to a stirred tank and diluted with toluene to a solid content of 30%. The mixture was stirred and mixed evenly to obtain the resin composition.

[0095] The resin film is prepared as follows:

[0096] The above resin composition was coated onto a release film and dried at 120°C to a semi-cured state. The release film was then removed to obtain a resin film. The thickness of the resin film is shown in Table 2-5 below.

[0097] The method for preparing the copper-clad laminate is as follows:

[0098] Six 1080mm thick S7135 hydrocarbon prepreg sheets were stacked together, with one resin film on top and bottom. A copper foil was then stacked on top of each resin film. The mixture was then placed in a press for curing to obtain a copper-clad laminate. The curing time was 180 minutes, the curing temperature was 240℃, and the curing pressure was 50 kg / cm². 2 The copper-clad laminate is obtained.

[0099] Comparative Example 9

[0100] This comparative example provides a copper-clad laminate, which differs from Example 1 only in that:

[0101] The method for preparing the copper-clad laminate is as follows:

[0102] Six 1080 mesh, 3.33 mil thick S7135 hydrocarbon prepreg sheets were stacked. A copper foil (3 oz NPM copper foil, H-1) was then stacked on each of the top and bottom sides of the resulting prepreg sheet. No resin film was stacked. The sheets were then placed in a press for curing to obtain a copper-clad laminate. The curing time was 180 minutes, the curing temperature was 240℃, and the curing pressure was 50 kg / cm². 2 The copper-clad laminate is obtained.

[0103] Other conditions are the same as in Example 1.

[0104] Comparative Example 13

[0105] This comparative example provides a copper-clad laminate, which differs from Example 1 only in that:

[0106] The method for preparing the copper-clad laminate is as follows:

[0107] Six 1080mm thick S7135 hydrocarbon prepreg sheets were stacked together. A copper foil (HOZ RTF-3, H-2 from Taiwan) was then placed on each side of the resulting prepreg sheet and cured in a press to produce a copper-clad laminate. The curing time was 180 minutes, the curing temperature was 240°C, and the curing pressure was 50 kg / cm². 2 The copper-clad laminate is obtained.

[0108] Other conditions are the same as in Example 1.

[0109] Performance testing:

[0110] The resin film strength, dielectric constant (Dk), dielectric loss tangent (Df), peel strength (PS), thermal stress, and flame retardancy of the copper-clad laminates provided in the above embodiments and comparative examples were tested. The specific test methods are as follows:

[0111] Release effect: The easier it is to peel the film off from the release film, the better the release effect. Conversely, if the film tears during the peeling process, making it impossible to obtain a complete film, or if it is difficult to peel off, the release effect is poor.

[0112] Note: ◎ indicates high strength and easy to peel off from the release film; ○ indicates moderate strength and can be peeled off from the release film to obtain a complete film; △ indicates poor strength, brittle, and cannot obtain a complete film or is difficult to peel off.

[0113] Dielectric constant (Dk) and dielectric loss tangent (Df): Determined at 10 GHz using the split dielectric pillar resonator method (SPDR) according to the method specified in IPC-TM-650 2.5.5.15.

[0114] Peel strength (PS): The peel strength of the copper foil was tested under the "post-thermal stress" test conditions in IPC-TM-650 2.4.8, in N / mm.

[0115] Thermal stress: Tested according to IPC-TM-650 2.4.13.1.

[0116] Flame retardancy: Tested and classified according to the material flammability method specified in UL-94.

[0117] The performance test results are detailed in Table 2 below.

[0118] Table 2

[0119]

[0120] Table 3

[0121]

[0122] Table 4

[0123]

[0124]

[0125] Note: When the release effect is "△", a complete resin film cannot be obtained for pressing, and there are no board material specifications.

[0126] Table 5

[0127]

[0128] As can be seen from the above, this invention, through the design of the resin composition, by using thermoplastic polyphenylene ether, low molecular weight polyolefin resin, and high tensile strength polyolefin resin in combination, and controlling the amount of each within a specific range, has prepared a resin composition with excellent performance. This composition then produces a resin film with ultra-thin thickness, compatible with high-frequency substrates, able to withstand the high-temperature pressing conditions of high-frequency substrates, and suitable for processing thick copper products on high-frequency hydrocarbon substrates. The prepared resin film is easily peeled off from the release film. The resulting metal foil laminate has a dielectric constant of 3.34-3.69, a dielectric loss tangent of 0.0033-0.0039, and a peel strength of 1.14-1.59. It also passes the thermal stress test, with a thermal stress (288℃ copper immersion in tin) > 180s, and exhibits good flame retardancy, with a flame retardancy rating of V-0.

[0129] As can be seen from Examples 1, 10-15 and Comparative Examples 1-6, the present invention prepares resin films and metal foil laminates with excellent performance by controlling the amount of thermoplastic polyphenylene ether, low molecular weight polyolefin resin and high tensile strength polyolefin resin within a specific range.

[0130] As can be seen from Examples 1, 16-17 and Comparative Examples 7-8, the present invention obtains high-performance resin films and metal foil laminates by controlling the thickness of the resin film within a specific range.

[0131] As can be seen from Examples 1-17 and Comparative Example 9, the present invention has prepared a high-performance metal foil laminate by using a resin film.

[0132] As can be seen from Examples 1-17 and Comparative Examples 10-12, the present invention, by designing the specific composition of the resin composition, prepares a resin composition and resin film with excellent performance, thereby improving the overall performance of the metal foil laminate.

[0133] As demonstrated in Examples 1-17 and Comparative Examples 13-14, the resin film provided by this invention is suitable for processing thick copper products on high-frequency hydrocarbon substrates, resulting in a high peel strength in the metal foil laminate prepared therefrom. In summary, this invention, through the design of the resin composition and the combined use of thermoplastic polyphenylene ether, low molecular weight polyolefin resin, and high tensile strength polyolefin resin, while controlling the amounts of these three components within a specific range, has prepared a resin composition with excellent performance. This results in a resin film with ultra-thin thickness, compatibility with high-frequency substrates, ability to withstand the high-temperature pressing conditions of high-frequency substrates, and suitability for processing thick copper products on high-frequency hydrocarbon substrates.

[0134] The applicant declares that the detailed process flow of this invention is illustrated by the above embodiments, but this invention is not limited to the above detailed process flow, that is, it does not mean that this invention must rely on the above detailed process flow to be implemented. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of raw materials for the product of this invention, addition of auxiliary components, and selection of specific methods, etc., all fall within the protection scope and disclosure scope of this invention.

Claims

1. A resin composition, characterized in that, The resin composition comprises the following components in parts by weight: (A) Thermoplastic polyphenylene ether, 40-50 parts; (B) Low molecular weight polyolefin resin, 10-25 parts; the number average molecular weight of the low molecular weight polyolefin resin is ≤5000 g / mol; the weight ratio of butadiene units added at the 1,2 positions in the low molecular weight polyolefin resin is ≥65%; (C) High tensile strength polyolefin resin, 20-50 parts, wherein the tensile strength of the high tensile strength polyolefin resin is ≥20MPa.

2. The resin composition according to claim 1, characterized in that, The thermoplastic polyphenylene ether resin includes the following structural units: ； R1, R2, R3 and R4 are each independently selected from any one of hydrogen, halogen atom, C1-C7 alkyl, C1-C7 haloalkyl, C1-C7 aminoalkyl, C1-C7 alkoxy, C6-C10 aryl or C6-C10 aryloxy.

3. The resin composition according to claim 1, characterized in that, The thermoplastic polyphenylene ether is selected from poly(2,6-dimethyl-1,4-phenylene) ether, poly(2,3,6-trimethyl-1,4-phenylene) ether, poly(2,6-diethyl-1,4-phenylene) ether, poly(2,6-dipropyl-1,4-phenylene) ether, poly(2-methyl-6-allyl-1,4-phenylene) ether, poly(di-tert-butyl-dimethoxy-1,4-phenylene) ether, poly(2,6-dichloromethyl- Any one or at least two combinations of 1,4-phenylene ether, poly(2,6-dibromomethyl-1,4-phenylene) ether, poly(2,6-di(2-chloroethyl)-1,4-phenylene) ether, poly(2,6-xylyl-1,4-phenylene) ether, poly(2,6-dichloro-1,4-phenylene) ether, poly(2,6-diphenyl-1,4-phenylene) ether, and poly(2,5-dimethyl-1,4-phenylene) ether.

4. The resin composition according to claim 1, characterized in that, The low molecular weight olefin resin is selected from any one or a combination of at least two of the following: polybutadiene resin with unsaturated double bonds, modified polybutadiene resin with unsaturated double bonds, or polybutadiene copolymer resin with unsaturated double bonds.

5. The resin composition according to claim 4, characterized in that, The polybutadiene resin with unsaturated double bonds includes 1,2-polybutadiene resin.

6. The resin composition according to claim 4, characterized in that, The modified polybutadiene resin with unsaturated double bonds is selected from any one or a combination of at least two of the following: maleic anhydride modified polybutadiene resin, acrylate modified polybutadiene resin, epoxy modified polybutadiene resin, amino modified polybutadiene resin, carboxyl-terminated modified polybutadiene resin, and hydroxyl-terminated modified polybutadiene resin.

7. The resin composition according to claim 4, characterized in that, The polybutadiene copolymer resin with unsaturated double bonds is selected from any one or a combination of at least two of the following: polybutadiene-styrene copolymer resin, polybutadiene-styrene-divinylbenzene graft copolymer resin, maleic anhydride modified styrene-butadiene copolymer resin, and acrylate modified styrene-butadiene copolymer resin.

8. The resin composition according to claim 1, characterized in that, The high tensile strength polyolefin resin is selected from any one or a combination of at least two of the following: elastomeric block copolymers, ethylene propylene rubber, polybutadiene rubber, and styrene-butadiene rubber.

9. The resin composition according to claim 8, characterized in that, The elastomeric block copolymer is selected from any one or a combination of at least two of the following: styrene-butadiene diblock copolymer, styrene-butadiene-styrene triblock copolymer, styrene-(ethylene-butene)-styrene triblock copolymer, styrene-isoprene diblock copolymer, styrene-isoprene-styrene triblock copolymer, styrene-(ethylene-propylene)-styrene triblock copolymer, and styrene-(ethylene-butene) diblock copolymer.

10. The resin composition according to claim 1, characterized in that, The resin composition also includes a flame retardant.

11. The resin composition according to claim 10, characterized in that, The flame retardant is selected from bromine-containing flame retardants and / or phosphorus-containing flame retardants.

12. The resin composition according to claim 1, characterized in that, The resin composition also includes a free radical initiator.

13. The resin composition according to claim 12, characterized in that, The free radical initiator is selected from organic peroxide free radical initiators and / or carbon-based free radical initiators.

14. The resin composition according to claim 1, characterized in that, The resin composition also includes additives.

15. The resin composition according to claim 14, characterized in that, The additives include any one or a combination of at least two of the following: crosslinking agents, coupling agents, leveling agents, defoamers, antioxidants, heat stabilizers, antistatic agents, ultraviolet absorbers, pigments, colorants, or lubricants.

16. A resin film, characterized in that, The resin film is obtained by coating a release material with the resin composition according to any one of claims 1-15.

17. The resin film according to claim 16, characterized in that, The thickness of the resin film is 10~25 μm.

18. The resin film according to claim 17, characterized in that, The thickness of the resin film is 15~20μm.

19. A metal foil-coated laminate, characterized in that, The metal foil laminate includes copper foil and at least one resin film as described in any one of claims 16-18.

20. The metal foil-coated laminate according to claim 19, characterized in that, The metal foil laminate also includes a prepreg.

21. The metal foil-coated laminate according to claim 19, characterized in that, The copper foil is a thick copper foil with a thickness of ≥3OZ (105μm).

22. A printed circuit board, characterized in that, The printed circuit board includes the resin film according to any one of claims 16-18.

23. The printed circuit board according to claim 22, characterized in that, The printed circuit board is a high-frequency substrate.

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