Laminated board and printed circuit board including same

Abstract

The invention provides a laminated board and a printed circuit board comprising the same. The laminated board comprises a resin substrate and a metal foil layer. The resin substrate comprises a plurality of prepregs, and each prepreg is formed by coating a reinforcing material with a thermosetting resin composition. The total weight of the thermosetting resin composition is 100 parts by weight, and the thermosetting resin composition comprises the following components in parts by weight: (A) 30-50 parts of unsaturated polyphenyl ether resin; (B) 10 to 30 parts by weight of a styrene-butylene block copolymer; (C) 5 to 25 parts by weight of a cycloolefin compound; (D) 1 to 10 parts by weight of a vinylphenyl compound; and (E) 5 to 25 parts by weight of a crosslinking agent. The laminated board and the printed circuit board provided by the invention have the characteristics of low dielectric constant, low dielectric loss and high peel strength of the electronic circuit base material by virtue of the specific thermosetting resin composition and the matching of the specific thermosetting resin composition and the reinforcing material in proportion.

Description

TECHNICAL FIELD

[0001] The present application relates to a laminate and a printed circuit board, in particular, to a laminate containing a specific composition of thermosetting resin composition and a printed circuit board comprising the same. BACKGROUND

[0002] The progress of modern information processing technology has led to the development of digital circuits for high-speed information processing and high-frequency signal transmission. In high-frequency circuits, the transmission loss of electrical signals is represented by the sum of dielectric loss and conductor loss, and radiation loss. The higher the frequency of the electrical signal, the greater the transmission loss of the electrical signal.

[0003] Since transmission loss causes attenuation of electrical signals, it can affect the reliability of electrical signals. Therefore, it is necessary to reduce dielectric loss, conductor loss, and radiation loss. The dielectric loss of an electrical signal is directly proportional to the product of the dielectric loss angle of the insulator forming the circuit and the frequency of the electrical signal used. Therefore, by selecting an insulating material with a small dielectric loss angle, the transmission loss of the electrical signal can be reduced.

[0004] US9428646B2 discloses the use of unsaturated polyphenyl ether and polybutadiene resin mixture to control the dielectric properties of the insulating board. However, the compatibility of unsaturated polyphenyl ether and butadiene is poor, and the mixed product is prone to segregation. Further, bismaleimide is added to provide better copper bonding, however, the laminates prepared from these materials have a relatively high dissipation factor.

[0005] US5223568A discloses the use of polybutadiene, polyisoprene, and thermoplastic elastomer to prepare laminates, and the obtained laminates have the characteristic of low loss. However, the peel strength of the polybutadiene board bonded to the copper foil is poor, and other properties such as mechanical strength, flammability, and heat resistance are also unsatisfactory.

[0006] Therefore, there is a need to provide a laminate and a printed circuit board for electronic circuits to meet the requirements of low dielectric constant, low dielectric loss, high peel strength, and other comprehensive properties for electronic circuit products. SUMMARY

[0007] The present application relates to a laminate, which comprises: a resin substrate and a metal foil layer disposed on at least one surface of the resin substrate. The resin substrate comprises a plurality of prepreg sheets, and each of the prepreg sheets is made of a reinforcing material coated with a thermosetting resin composition. The thermosetting resin composition comprises, based on 100 parts by weight of the total weight of the thermosetting resin composition: (A) 30 to 50 parts by weight of an unsaturated polyphenylene ether resin; (B) 10 to 30 parts by weight of a styrene-butylene block copolymer; (C) 5 to 25 parts by weight of a cyclic olefin compound; (D) 1 to 10 parts by weight of a vinyl phenyl compound; and (E) 5 to 25 parts by weight of a crosslinking agent. The unsaturated polyphenylene ether resin comprises at least one carbon-carbon double bond or carbon-carbon triple bond and at least one carboxyl group selected from the group consisting of carboxylic acids, acid anhydrides, amides, and esters.

[0008] In an embodiment of the present application, the reinforcing material is a polystyrene fiber cloth.

[0009] In an embodiment of the present application, the styrene-butylene block copolymer is a block copolymer derived from an alkenyl aromatic compound block and a conjugated diene block.

[0010] In an embodiment of the present application, the styrene-butylene block copolymer is a styrene-butylene block copolymer grafted with maleic anhydride.

[0011] In an embodiment of the present application, the styrene-butylene block copolymer is at least one selected from the group consisting of styrene-butadiene diblock copolymer (SB), styrene-butadiene-styrene triblock copolymer (SBS), styrene-isoprene diblock copolymer (SI), styrene-isoprene-styrene triblock copolymer (SIS), styrene-(ethylene-butylene)-styrene triblock copolymer (SEBS), styrene-(ethylene-propylene)-styrene triblock copolymer (SEPS), and styrene-(ethylene-butylene) diblock copolymer (SEB).

[0012] In an embodiment of the present application, the cyclic olefin compound is at least one selected from the group consisting of dicyclopentadiene (DCPD) monomer, dicyclopentadiene polymer, norbornene monomer, and 5-norbornene polymer.

[0013] In an embodiment of the present application, the vinyl phenyl compound is selected from diphenylstyrene and / or bromostyrene.

[0014] In an embodiment of the present application, the crosslinking agent is at least one selected from the group consisting of triallyl isocyanurate, triallyl cyanurate, bismaleimide resin, and divinyl benzene.

[0015] In an embodiment of the present application, the thermosetting resin composition further comprises a promoter selected from at least one of the group consisting of di-tert-butyl peroxide, dilauroyl peroxide, dibenzoyl peroxide, tert-butyl peroxyacetate, tert-butyl peroxybenzoate, 1,1-di-tert-butyl peroxy-3,5,5-trimethylcyclohexane, 1,1-di-tert-butyl peroxycyclohexane, 2,2-di(tert-butylperoxy)butane, bis(4-tert-butylcyclohexyl)peroxy dicarbonate, peroxydicarbonate hexadecyl, peroxydicarbonate tetradecyl, diisopropyl adipate, diisopropylbenzene peroxide, bis(tert-butylperoxy isopropyl)benzene, 2,5-dimethyl-2,5-di-tert-butylperoxyhexane, 2,5-dimethyl-2,5-di-tert-butylperoxyhexyne, and cumene hydroperoxide.

[0016] In an embodiment of the present application, the thermosetting resin composition further comprises an inorganic filler selected from at least one of the group consisting of silicon dioxide, aluminum oxide, aluminum hydroxide, magnesium oxide, magnesium hydroxide, calcium carbonate, aluminum nitride, boron nitride, aluminum silicon carbide, silicon carbide, titanium dioxide, zinc oxide, zirconium oxide, barium sulfate, magnesium carbonate, barium carbonate, mica, talc, and graphene.

[0017] Another object of the present application is to provide a printed circuit board comprising the build-up board as described in the present application.

[0018] One of the beneficial effects of the present application is that the build-up board and the printed circuit board comprising the same can meet the requirements of low dielectric constant, low dielectric loss, high peel strength, and other comprehensive properties of electronic circuit substrates by the technical solutions of "the reinforcing material is polystyrene fiber cloth", "the unsaturated polystyrene resin comprises at least one carbon-carbon double bond or carbon-carbon triple bond, and at least one carboxyl group", and specific formulation proportions. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 FIG. 1 is a structural schematic diagram of the build-up board of the present application; Figure 2 FIG. 2 is a structural schematic diagram of the printed circuit board of the present application.

[0020] Explanation of symbols in the drawings: P printed circuit board; L build-up board; 1 resin substrate; 2 metal foil layer; 11 semi-cured prepreg; 111 reinforcing material; 112 thermosetting resin composition. Detailed Implementation

[0021] The technical solution adopted in this invention is to provide a laminated plate, such as... Figure 1 As shown, the laminate L of the present invention comprises: a resin substrate 1 and a metal foil layer 2 disposed on at least one surface of the resin substrate. The resin substrate 1 comprises a plurality of precured films 11, and each of the precured films 11 is made by coating a reinforcing material 111 with a thermosetting resin composition 112. The thermosetting resin composition comprises, in 100 parts by weight,: (A) 30 to 50 parts by weight of unsaturated polyphenylene ether resin; (B) 10 to 30 parts by weight of styrene-butene block copolymer; (C) 5 to 25 parts by weight of cyclic olefin compound; (D) 1 to 10 parts by weight of vinylphenyl compound; and (E) 5 to 25 parts by weight of crosslinking agent; wherein the unsaturated polyphenylene ether resin comprises at least one carbon-carbon double bond or carbon-carbon triple bond, and at least one carboxyl group.

[0022] In one embodiment of the present invention, the reinforcing material is E-glass, NE-glass, or polystyrene fiber cloth. E-glass, also known as alkali-free glass, is a borosilicate glass with excellent electrical insulation and mechanical properties, and is widely used in the production of glass fibers for electrical insulation. NE-glass has characteristics such as low dielectric constant and low dielectric loss factor. Compared to reinforcing materials such as polyethylene and polypropylene fibers with relatively low melting points, the present invention selects specific reinforcing materials to maintain the CTE and heat resistance of the laminate.

[0023] Specifically, polyphenylene ether (PPE) resin possesses excellent mechanical properties and superior dielectric properties, with a Dk / Df ratio of approximately 2.45 / 0.0007 at 1MHz, making it a preferred resin material for high-frequency printed circuit board substrates. Preferably, the unsaturated polyphenylene ether resin used in this invention is modified and includes the following polyfunctional compounds: at least one carbon-carbon double bond or carbon-carbon triple bond, and at least one carboxyl group, for example, carboxylic acids, acid anhydrides, amides, or esters. More specifically, the unsaturated polyphenylene ether resin used in this invention can be a terminal vinyl benzyl-modified polyphenylene ether resin or a difunctional methacrylate-modified polyphenylene ether resin.

[0024] A styrene-butene block copolymer is a block copolymer comprising (A) blocks derived from alkenyl aromatic compounds and (B) blocks derived from conjugated dienes. More specifically, the styrene-butene block copolymer may be selected from at least one of the group consisting of styrene-butadiene diblock copolymer (SB), styrene-butadiene-styrene triblock copolymer (SBS), styrene-isoprene diblock copolymer (SI), styrene-isoprene-styrene triblock copolymer (SIS), styrene-(ethylene-butene)-styrene triblock copolymer (SEBS), styrene-(ethylene-propylene)-styrene triblock copolymer (SEPS), and styrene-(ethylene-butene) diblock copolymer (SEB). In a specific embodiment of the invention, the styrene-butene block copolymer is a maleic anhydride-grafted styrene-butene block copolymer.

[0025] Vinylphenyl compounds are selected from stilbene and / or bromostyrene compounds, such as Saytex 3010 brominated styrene purchased from Albemarle. More specifically, bromostyrene compounds offer advantages such as high flame retardancy, thermal stability, better compatibility, and non-leaching.

[0026] Cyclic olefin compounds are selected from at least one or a combination thereof from the group consisting of dicyclopentadiene (DCPD) monomers having bridged ring hydrocarbons, dicyclopentadiene polymers, norbornene monomers and norbornene polymers.

[0027] Preferably, the crosslinking agent can be at least one selected from the group consisting of triallyl isocyanate (TAIC), triallyl cyanurate (TAC), bismaleimide resin, and divinylbenzene. If the proportion of the crosslinking agent is too high, it will reduce the thermal conductivity of the crosslinked resin composition (e.g., lower the thermal conductivity coefficient K value). If the proportion of the crosslinking agent is too low, it will result in poor thermal properties of the crosslinked resin composition (e.g., lower glass transition temperature Tg).

[0028] Furthermore, depending on the physical properties required by the product, different accelerators can be used. Preferably, the accelerator is a peroxide crosslinking accelerator, and more specifically, an organic peroxide free radical initiator. For example, the accelerator is selected from at least one group consisting of di-tert-butyl peroxide, dilauroyl peroxide, benzoyl peroxide, tert-butyl peroxyacetate, tert-butyl peroxybenzoate, 1,1-di-tert-butylperoxy-3,5,5-trimethylcyclohexane, 1,1-di-tert-butylperoxycyclohexane, 2,2-di(tert-butylperoxy)butane, bis(4-tert-butylcyclohexyl)peroxydicarbonate, hexadecyl peroxydicarbonate, tetradecyl peroxydicarbonate, dipentylhexyl peroxide, dicumylene peroxide, diisopropylbenzene peroxide, bis(tert-butylperoxyisopropyl)benzene, 2,5-dimethyl-2,5-di-tert-butylperoxyhexane, 2,5-dimethyl-2,5-di-tert-butylperoxyhexyne, and diisopropylbenzene hydroperoxide. In one embodiment, the accelerator is diisopropylbenzene peroxide (DCP), commercially available from Arkema.

[0029] Silane coupling agents can improve the metal adhesion of polyolefin materials. Commonly used silane coupling agents in this technical field can be selected. For example, the inorganic functional group of the silane coupling agent is a trifunctional group, namely Si-(OR2). In one embodiment of the present invention, the silane coupling agent can be vinylsilane, aminosilane, methacryloxysilane, etc.

[0030] Preferably, the flame retardant is a phosphorus-containing flame retardant or a brominated flame retardant. Examples of brominated flame retardants include ethylene-bis(tetrabromophthalimide), decabromodiphenyl ethane, and 2,4,6-tris(2,4,6-tribromophenoxy)-1,3,5-triazine. Examples of phosphorus-containing flame retardants include bisphenol diphenyl phosphate, ammonium polyphosphate, hydroquinone bis(bis(bis(bis(bis(bis(bis(bis(bis(bis(bis(bis(bis(bis(bis(bis(bis(bis(bis(bis(bis(bis(s(xyl)))))))))))))))))))))))))))))))))))))"""))))""")))""")-xon-9-oxa-10-phosphaphenanthrene-10-oxide) (DOPO) and its derivatives or resins), melamine cyanurate, and trihydroxyethyl isocyanurate).

[0031] In one embodiment of the present invention, the flame retardant may be a DOPO compound, such as a DOPO resin (DOPO-HQ, DOPO-NQ, DOPO-PN, or DOPO-BPN) and a DOPO-containing epoxy resin. More specifically, DOPO-BPN may be selected from bisphenol A varnish compounds, such as DOPO-BPAN, DOPO-BPFN, or DOPO-BPSN.

[0032] Inorganic fillers are selected from the group consisting of silica, alumina, barium sulfate, talc, clay, mica powder, and boron nitride. More preferably, inorganic fillers are selected from the group consisting of fused silica, amorphous silica, and hollow silica, such as Lianrui D1028L spherical silica, which can adjust the dielectric constant, dielectric loss, and coefficient of thermal expansion of the dielectric substrate layer. Specifically, inorganic fillers can increase the thermal conductivity of resin compositions, improve their thermal expansion properties, and enhance their mechanical strength.

[0033] See Figure 2 The multilayer board L of the present invention can be applied to a printed circuit board P, which is formed by patterning the metal foil layer 2 of the multilayer board L. For example, the metal foil layer 2 can be patterned by electroplating or etching processes to further form a printed circuit line layer.

[0034] [Example] Tables 1 to 3 of this invention provide the component ratios and reinforcing materials of thermosetting resin compositions of Examples 1 to 14 and Comparative Examples 1 to 7, respectively. Thermosetting resin compositions are prepared according to each component ratio, and reinforcing materials are impregnated or coated onto the thermosetting resin compositions using rollers. After baking to evaporate the solvent and semi-curing the resin, the mixture is cooled and wound to form a semi-cured film. The semi-cured film is further subjected to hot pressing to form a dielectric substrate layer. Specifically, the hot pressing process involves stacking four semi-cured films and two 18 μm copper foils (metal foil layers) from the same batch in the order of copper foil, four semi-cured films, and copper foil. The copper foil substrate is then formed by pressing at 220°C for 2 hours under vacuum conditions. The four semi-cured films are cured to form an insulating layer between the two copper foils. The copper foil is etched by a wet etching process to form a wiring pattern, thereby forming a specific wiring circuit and obtaining a printed circuit board.

[0035] The copper foil substrate underwent physical property testing, and the results are recorded in Tables 1 to 3.

[0036] [Physical Property Testing] Peel strength: Peel pull test conducted according to industry standards.

[0037] Copper foil laminate heat resistance (T288): also known as "tinning result", the heat resistance test is based on industry standard IPC-TM-650 2.4.24.1, which is the time required for the copper foil laminate to immerse in a tin bath at 288°C until the board bursts.

[0038] Dielectric constant (Dk): Measured according to IPC-TM-650 2.5.5 test specifications. The dielectric constant represents the electronic insulation characteristics of the film. The lower the value, the better the electronic insulation characteristics.

[0039] Dielectric loss (Df): Measured according to IPC-TM-650 2.5.5 test specifications. Dielectric loss represents the ability of a material to absorb microwaves of a certain frequency at a certain temperature. In the specifications of communication products, the lower the dielectric loss value, the better.

[0040] Coefficient of thermal expansion (CTE): Measured according to the IPC-TM-650-2.4.24 test standard.

[0041] Table 1. Examples 1 to 4 and Comparative Examples 1 to 2

[0042] Table 2. Examples 5 to 7 and Comparative Examples 3 to 5

[0043] Table 3. Examples 11 to 14 and Comparative Examples 6 and 7

[0044] OPE-2St 2200: Terminal vinyl benzyl modified polyphenylene ether (Mw: approx. 3600, purchased from Mitsubishi Gas Chemical Co., Ltd.) SA9000: Bifunctional methacrylate-modified polyphenylene ether (Mw: 1700, purchased from SABIC). SA90: Unmodified polyphenylene ether (Mw: 1700, commercially available from SABIC Innovative Plastics Ltd.) PPO640: Unmodified polyphenylene ether (molecular weight: 18,000, commercially available from SABIC Innovative Plastics Ltd.) D1118: Solid SB-SBS copolymer (commercially available from Kraton Polymers) G1648: SEBS compound (commercially available from Kraton Polymers) KIC19-023: Maleic anhydride-grafted SEBS copolymer (commercially available from Kraton Polymers). Saytex3010: Brominated Styrene DCPD monomer: Dicyclopentadiene (purchased from Zibo Luhua Hongjin New Materials Commercial) Topas COC 5013: A cyclic olefin copolymer without reactive functional groups. TAIC: Triallyl Isocyanurate MIR3000: Biphenyl-type BMI DCP: Dicumyl peroxide (commercially available from Arkema) KBM503: Vinylsilane (purchased from Shin-Etsu Commercial, Japan) Saytex 8010: Decabromodiphenyl ethane D1028L: Spherical silica purchased from Lianrui Commercial Referring to Table 1, Examples 1 to 4 and Comparative Examples 1 and 2 show that the unmodified polyphenylene ether has poor dielectric properties due to the presence of hydroxyl groups. In addition, the unmodified polyphenylene ether has better heat resistance to tin bleaching.

[0045] Referring to Table 2, the maleic anhydride-modified styrene-butene block copolymer effectively improves peel strength with minimal impact on dielectric properties. Comparative Example 3 shows that a decrease in the proportion of polyphenylene ether in the thermosetting resin formulation leads to poorer heat resistance, while the addition of vinylphenyl compounds and crosslinking agents (tracene propyl isocyanurate, TAIC) helps improve heat resistance.

[0046] Referring to Table 3, Comparative Examples 6 and 7 use polyethylene (PE) and polypropylene (PP) fiber reinforcement materials with low melting points, which melt during the pressing process (above 190 degrees Celsius), resulting in higher CTE and poorer heat resistance of the substrate.

[0047] The beneficial effects of the present invention are that the multilayer board and the printed circuit board including the multilayer board provided by the present invention include a specific thermosetting resin composition, which can provide and meet the comprehensive performance requirements of electronic circuit substrates for low dielectric constant, low dielectric loss, and high peel strength through the technical solution that "the unsaturated polyphenylene ether resin includes: at least one carbon-carbon double bond or carbon-carbon triple bond, and at least one carboxyl group" and a specific formulation ratio.

[0048] More specifically, the modified unsaturated polyphenylene ether resin with specific groups improves the low dielectric properties caused by the presence of hydroxyl groups in polyphenylene ether and increases its heat resistance. Maleic anhydride-modified styrene-butene block copolymers further enhance peel strength while maintaining their dielectric properties.

[0049] The above description is only a preferred embodiment of the present invention and is not intended to limit the patent scope of the present invention. Therefore, all equivalent changes made using the content of the present invention are similarly included within the scope of the present invention and are hereby declared.

Claims

1. A laminate, characterized by Comprising: a resin substrate comprising a plurality of prepreg sheets, and each of the prepreg sheets is made of a reinforcing material coated with a thermosetting resin composition, the reinforcing material is polystyrene fiber cloth; and a metal foil layer disposed on at least one surface of the resin substrate; wherein the thermosetting resin composition comprises, with respect to 100 parts by weight of the total weight of the thermosetting resin composition: (A) 30 to 50 parts by weight of an unsaturated polyphenyl ether resin selected from a terminal vinyl benzyl-modified polyphenyl ether resin or a difunctional methacrylate-modified polyphenyl ether resin; (B) 10 to 30 parts by weight of a copolymer selected from at least one of a styrene-butadiene diblock copolymer, a styrene-butadiene-styrene triblock copolymer, and a styrene-(ethylene-butylene)-styrene triblock copolymer; (C) 5 to 25 parts by weight of a cyclic olefin compound; (D) 1 to 10 parts by weight of a vinyl phenyl compound, the vinyl phenyl compound being bromostyrene; and (E) 5 to 25 parts by weight of a crosslinking agent. The cyclic olefin compound is selected from at least one of a dicyclopentadiene monomer and a norbornene monomer.

2. The laminate of claim 1, wherein The crosslinking agent is selected from at least one of a triallyl isocyanurate, a triallyl cyanurate, a bismaleimide resin, and a divinyl benzene.

3. The laminate of claim 1, wherein The thermosetting resin composition further comprises a promoter selected from at least one of di-tert-butyl peroxide, dicumyl peroxide, dibenzoyl peroxide, tert-butyl peroxyacetate, tert-butyl peroxybenzoate, 1,1-di-tert-butyl peroxy-3,5,5-trimethylcyclohexane, 1,1-di-tert-butyl peroxy cyclohexane, 2,2-di(tert-butylperoxy)butane, bis(4-tert-butylcyclohexyl)peroxy dicarbonate, peroxydicarbonate hexadecyl, peroxydicarbonate tetradecyl, diisopropyl adipate, dicumyl peroxide, bis(tert-butylperoxy isopropyl)benzene, 2,5-dimethyl-2,5-di-tert-butylperoxy hexane, and 2,5-dimethyl-2,5-di-tert-butylperoxy hexyne.

4. The laminate of claim 1, wherein The thermosetting resin composition further comprises an inorganic filler selected from at least one of silicon dioxide, aluminum oxide, aluminum hydroxide, magnesium oxide, magnesium hydroxide, calcium carbonate, aluminum nitride, boron nitride, aluminum silicon carbide, silicon carbide, titanium dioxide, zinc oxide, zirconium oxide, barium sulfate, magnesium carbonate, barium carbonate, mica, talc, and graphene.

5. The laminate of claim 1 wherein 6. A printed circuit board comprising the build-up board of claim 1. ​

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