Laminated board and printed circuit board comprising the same

Abstract

The present invention provides a laminate and a printed circuit board comprising the same, wherein the laminate comprises a resin substrate and a metal foil layer. The resin substrate comprises a plurality of prepreg sheets, and each prepreg sheet is made of a reinforced 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 laminate and the printed circuit board of the present invention provide the electronic circuit substrate with low dielectric constant, low dielectric loss, and high peel strength by the specific thermosetting resin composition and the proportioning of the reinforced material.

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 the attenuation of electrical signals, it destroys the reliability of electrical signals, and 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, and 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, but the compatibility of unsaturated polyphenyl ether and butadiene is poor, and the mixed product is prone to precipitation. Further, it adds bismaleimide to provide better copper bonding, however, the laminate prepared from these materials has a relatively high dissipation factor.

[0005] US5223568A discloses a laminate prepared using polybutadiene, polyisoprene, and thermoplastic elastomer, the obtained laminate has the characteristics of small 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, it is necessary 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 of 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 E-glass, NE-glass, or PS-glass.

[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 cross-linking 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 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, diperoxyhexahydroterephthalate, dicumyl peroxide, bis(tert-butylperoxyisopropyl)benzene, 2,5-dimethyl-2,5-di-tert-butylperoxyhexane, 2,5-dimethyl-2,5-di-tert-butylperoxyhexyne, and cumyl hydroperoxide.

[0016] In an embodiment of the present application, the thermosetting resin composition further comprises an inorganic filler selected from 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 laminate as described in the present application.

[0018] One of the advantages of the present application is that the laminate and the printed circuit board comprising the laminate provided by the present application 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 E-glass, NE-glass, or PS-glass", "the unsaturated polyphenyl ether 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 laminate of the present application;

[0020] Figure 2 FIG. 2 is a structural schematic diagram of the printed circuit board of the present application.

[0021] Explanation of symbols in the drawings:

[0022] P Printed circuit board;

[0023] L-laminated plate;

[0024] 1. Resin substrate;

[0025] 2. Metal foil layer;

[0026] 11. Semi-cured film;

[0027] 111 Reinforcing materials;

[0028] 112 Thermosetting resin composition. Detailed Implementation

[0029] 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 includes: a resin substrate 1 and a metal foil layer 2 disposed on at least one surface of the resin substrate. The resin substrate 1 includes 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, in 100 parts by weight of its total weight, includes: (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 cycloolefin 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 includes at least one carbon-carbon double bond or carbon-carbon triple bond, and at least one carboxyl group.

[0030] In one embodiment of the present invention, the reinforcing material is E-glass, NE-glass, or polystyrene fiber cloth (PS-glass). 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.

[0031] Specifically, polyphenylene ether (PPE) resins have good mechanical properties and excellent dielectric properties with Dk / Df of about 2.45 / 0.0007 at 1 MHz, which is the preferred resin material for high frequency printed circuit board substrates. Preferably, the unsaturated polyphenylene ether resin used in the present application is modified and includes at least one carbon-carbon double bond or carbon-carbon triple bond and at least one carboxyl group, for example, as a carboxylic acid, anhydride, amide, ester. More specifically, the unsaturated polyphenylene ether resin used in the present application can be selected from a terminal vinyl benzyl modified polyphenylene ether resin or a difunctional methacrylate modified polyphenylene ether resin.

[0032] The styrene-butylene block copolymer is a block copolymer including (A) a block derived from an alkenyl aromatic compound and (B) a block derived from a conjugated diene. More specifically, the styrene-butylene block copolymer can 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-butylene)-styrene triblock copolymer (SEBS), styrene-(ethylene-propylene)-styrene triblock copolymer (SEPS), and styrene-(ethylene-butylene) diblock copolymer (SEB). In a specific embodiment of the present application, the styrene-butylene block copolymer is a styrene-butylene block copolymer grafted with maleic anhydride.

[0033] The vinyl phenyl compound is selected from diphenyl styrene and / or bromostyrene compound, for example, Saytex 3010 bromostyrene commercially available from Albemarle. In more detail, the bromostyrene compound provides high flame retardancy, thermal stability, better compatibility, and no precipitation.

[0034] The cyclic olefin compound is selected from at least one or a combination of the group consisting of dicyclopentadiene (DCPD) monomer having a bridged ring hydrocarbon, dicyclopentadiene polymer, norbornene monomer, and norbornene polymer.

[0035] Preferably, the crosslinking agent can be selected from at least one of the group consisting of triallyl isocyanurate (TAIC), triallyl cyanurate (TAC), bismaleimide resin, and divinyl benzene. If the proportion of the crosslinking agent is too high, the thermal conductivity properties (such as the thermal conductivity coefficient K value) of the resin composition after crosslinking will be reduced. If the proportion of the crosslinking agent is too low, the thermal value of the resin composition after crosslinking will be poor (for example, the glass transition temperature Tg is reduced).

[0036] Further, depending on the physical property requirements of the product, different accelerators can be used. Preferably, the accelerator is a peroxide crosslinking accelerator, more specifically, an organic peroxide radical initiator. For example, the accelerator is at least one selected from 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 ester, peroxydicarbonate tetradecyl ester, dipentylhexyl peroxide, dicumyl 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. In one embodiment, the accelerator is dicumyl peroxide (DCP) commercially available from Arkema.

[0037] The silane coupling agent can improve the metal adhesion of the polyolefin material, and any silane coupling agent known in the art can be used. For example, the inorganic functional group of the silane coupling agent is a trifunctional group, i.e., Si-(OR2). In one embodiment of the present application, the silane coupling agent can be vinyl silane, amino silane, methacryloxy silane, etc.

[0038] Preferably, the flame retardant is a phosphorus-containing flame retardant and a brominated flame retardant. Examples of the brominated flame retardant include ethylene-bis(tetrabromophthalimide), decabromodiphenyl ethane, and 2,4,6-tris(2,4,6-tribromophenoxy)-1,3,5-triazine. Examples of the phosphorus-containing flame retardant include bisphenol diphenyl phosphate, ammonium polyphosphate, hydroquinone bis(diphenyl phosphate), bisphenol A bis(diphenyl phosphate), tris(2-carboxyethyl)phosphine (TCEP), tris(chloroisopropyl)phosphate, trimethyl phosphate (TMP), dimethyl methylphosphonate (DMMP), resorcinol bis(dimethylphenyl phosphate), phosphazene, melamine polyphosphate, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and its derivatives or resins, melamine cyanurate, and trishydroxyethyl isocyanurate.

[0039] In one embodiment of the present application, the flame retardant can 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, the DOPO-BPN can be selected from bisphenol novolac compounds, such as DOPO-BPAN, DOPO-BPFN, or DOPO-BPSN.

[0040] The inorganic filler is selected from the group consisting of silicon dioxide, aluminum oxide, barium sulfate, talc, clay, mica powder, boron nitride. More preferably, the inorganic filler is selected from the group consisting of fused silica, amorphous silica and hollow silica, such as Dow Corning® D1028L spherical silica. The inorganic filler can adjust the dielectric constant, dielectric loss and coefficient of thermal expansion of the dielectric substrate layer. Specifically, the inorganic filler can increase the thermal conductivity of the resin composition, improve the thermal expansion and mechanical strength thereof.

[0041] Referring to Figure 2 The laminate L of the present application can be applied to a printed circuit board P formed by patterning the metal foil layer 2 of the laminate L. For example, the metal foil layer 2 can be patterned by an electroplating or etching process to further form a printed circuit line layer.

[0042] [Examples]

[0043] Tables 1 to 3 of the present application respectively provide the component proportions of the thermosetting resin compositions and the reinforcing materials of Examples 1 to 14 and Comparative Examples 1 to 7. The thermosetting resin compositions are prepared according to the respective component proportions, and the reinforcing materials are immersed or roller-coated to impregnate the thermosetting resin compositions, which are then subjected to baking to evaporate solvents and to semi-cure the resins, cooling and winding to form semi-cured sheets. The semi-cured sheets are further subjected to hot-pressing to form dielectric substrate layers. Specifically, the hot-pressing is performed on four sheets of the same batch of semi-cured sheets and two sheets of 18 μm copper foil (metal foil layer) in the order of copper foil, four sheets of semi-cured sheets, copper foil, and then laminated under vacuum at 220°C for 2 hours to form a copper foil substrate, in which the four sheets of semi-cured sheets are cured to form an insulating layer between the two copper foils. The aforementioned copper foils are etched by a wet etching process to form a wiring pattern, thereby forming a specific wiring circuit to obtain a printed circuit board.

[0044] The copper foil substrates are subjected to physical property tests and the results are recorded in Tables 1 to 3.

[0045] [Physical property tests]

[0046] Peel strength: The peel strength is tested according to the industry standard.

[0047] T288: Also known as "float tin result", the heat resistance test is performed according to the industry standard IPC-TM-650 2.4.24.1. The copper foil laminate is immersed in a 288°C tin furnace until the substrate is blown off.

[0048] Dielectric constant (Dk): The dielectric constant is measured according to the IPC-TM-650 2.5.5 test specification. The dielectric constant represents the electronic insulation property of the prepared sheet, and the lower the value, the better the electronic insulation property.

[0049] Dielectric loss (Df): measured according to IPC-TM-650 2.5.5 test specification. Dielectric loss represents the ability of a material to absorb microwaves of a certain frequency at a certain temperature. In general, the lower the dielectric loss value, the better the material is for communication products.

[0050] Coefficient of thermal expansion (CTE): measured according to IPC-TM-650-2.4.24 test standard.

[0051] Table 1. Examples 1 to 4 and Comparative Examples 1 to 2

[0052]

[0053] Table 2. Examples 5 to 7 and Comparative Examples 3 to 5

[0054]

[0055] Table 3. Examples 11 to 14 and Comparative Examples 6 and 7

[0056]

[0057]

[0058] OPE-2St 2200: end-vinyl benzyl-modified polyphenylene ether (Mw: about 3600, available from Mitsubishi Gas Chemical America Corp.)

[0059] SA9000: difunctional methacrylate-modified polyphenylene ether (Mw: 1700, available from SABIC)

[0060] SA90: unmodified polyphenylene ether (Mw: 1700, commercially available from SABIC Innovative Plastics, LLC)

[0061] PPO640: unmodified polyphenylene ether, (Molecular weight: 18000, commercially available from SABIC Innovative Plastics, LLC)

[0062] D1118: solid SB-SBS copolymer (commercially available from Kraton Polymers)

[0063] G1648: SEBS compound (commercially available from Kraton Polymers)

[0064] KIC19-023: maleic anhydride grafted SEBS copolymer (commercially available from Kraton Polymers)

[0065] Saytex 3010: brominated styrene

[0066] DCPD monomer: dicyclopentadiene (commercially available from Zibo Luohua Hongjin New Material)

[0067] Topas COC 5013: cyclic olefin copolymer without reactive functional group

[0068] TAIC: triallyl isocyanurate

[0069] MIR3000: biphenyl type BMI

[0070] DCP: dicumyl peroxide (commercially available from Arkema)

[0071] KBM503: vinyl silane (commercially available from Japan Shin-Etsu)

[0072] Saytex 8010: decabromodiphenyl ethane

[0073] D1028L: spherical silica commercially available from Link-Rui

[0074] 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, and in addition, the unmodified polyphenylene ether has good tin float resistance and heat resistance.

[0075] Referring to Table 2, the styrene-butylene block copolymer modified by maleic anhydride can effectively improve the peel strength, and has little effect on the dielectric properties. As shown in Comparative Example 3, the proportion of polyphenylene ether in the formulation of the thermosetting resin composition decreases, which leads to poor heat resistance, and the addition of the vinyl phenyl compound and the crosslinking agent (triarylisocyanurate, TAIC) helps to improve the heat resistance.

[0076] Referring to Table 3, Comparative Examples 6 and 7 use polyethylene (PE) and polypropylene (PP) fiber reinforcing materials, respectively, and the melting points of the reinforcing materials are low, which leads to melting during the pressing process (above 190 degrees), resulting in high CTE and poor heat resistance of the substrate.

[0077] The printed circuit board provided by the present application has the advantages that the laminated board and the printed circuit board including the laminated board provided by the present application include a specific thermosetting resin composition, which can meet the requirements of electronic circuit substrates for low dielectric constant, low dielectric loss, high peel strength and other comprehensive properties by the technical solutions of the unsaturated polyphenylene ether resin including at least one carbon-carbon double bond or carbon-carbon triple bond and at least one carboxyl group and the specific formulation proportion.

[0078] In more detail, the unsaturated polyphenylene ether resin modified by the specific group improves the low dielectric properties caused by the presence of hydroxyl groups in the polyphenylene ether, and further increases the heat resistance. The styrene-butylene block copolymer modified by maleic anhydride further improves the peel strength, and maintains the dielectric properties.

[0079] The above descriptions are only the preferred embodiments of the present application, not therefore limit the patent scope of the present application, so that the equivalent changes made by applying the content of the present application are also included in the scope of the present application, and it is 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 E-glass fiber or NE-glass fiber; 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.

2. The laminate of claim 1, wherein The cyclic olefin compound is selected from at least one of a dicyclopentadiene monomer and a norbornene monomer.

3. 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.

4. The laminate of claim 1, wherein The thermosetting resin composition further comprises: a promoter selected from at least one 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, dicumyl peroxide, bis(tert-butylperoxy isopropyl)benzene, 2,5-dimethyl-2,5-di-tert-butylperoxyhexane, and 2,5-dimethyl-2,5-di-tert-butylperoxyhexyne.

5. 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.

6. A printed circuit board comprising the build-up board of claim 1.

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