HK1173464B - Resin composition, prepreg, and metal-clad laminate - Google Patents

Description

Resin composition, prepreg, and metal-clad laminate

Technical Field

The present invention relates to a resin composition for a printed wiring board material, and a prepreg and a laminate using the same, and more particularly, to a resin composition which has good molding appearance, excellent heat resistance after moisture absorption, and excellent dielectric properties, and is particularly suitable as a multilayer printed wiring board material in the field of high frequency.

Background

In recent years, information terminal devices such as personal computers and servers, network routers, and communication devices such as optical communication are required to process large amounts of information at high speed, and electric signals are required to have high speed and high frequency. Accordingly, in order to meet the high frequency requirement, laminates for printed wiring boards used in these devices are required to have a low dielectric constant and a low loss tangent, and particularly, a low loss tangent. In addition, lead-free solders having a high melting temperature have come to be used due to environmental problems, and therefore, further heat resistance is required for laminates for printed wiring boards.

Conventionally, polyphenylene ether resins (e.g., JP-A-2005-112981) and cyanate ester resins (e.g., JP-A-2005-120173) have been mainly used as laminate materials for high-frequency applications. However, polyphenylene ether resins have a problem of insufficient flow characteristics during molding due to a high melt viscosity due to a large molecular weight, and have a large limitation particularly in multilayer sheets, resulting in practical use. The cyanate ester resin has a low melt viscosity and good moldability, but is slightly insufficient in terms of low dielectric constant and low loss tangent. In addition, in the environment of lead-free solders processed at high temperatures, materials having high heat resistance are required, and therefore, it is also required to improve heat resistance of laminates using cyanate ester resins.

On the other hand, silica is added to a resin composition as an inorganic filler in order to achieve both high heat resistance and low loss tangent (for example, jp 2008-75012 a and jp 2008-88400 a). However, when a certain amount or more of silica is added to the resin composition, there is a problem that the dispersion of the resin and silica is not good, and the molded appearance is not uniform.

Documents of the prior art

Patent document

Patent document 1 Japanese patent laid-open No. 2005-112981

Patent document 2 Japanese patent laid-open publication No. 2005-120173

Patent document 3, Japanese patent laid-open No. 2008-75012

Patent document 4, Japanese patent laid-open No. 2008-88400

Disclosure of Invention

The present inventors have found that a metal-clad laminate having good molding appearance and excellent dielectric properties and heat resistance can be obtained by blending a resin composition containing a cyanate ester resin, an epoxy resin, a specific thermoplastic resin, spherical silica, and a wetting dispersant as essential components in specific ranges. The present invention is based on this finding.

Accordingly, an object of the present invention is to provide a cyanate resin composition for a high-frequency printed wiring board having excellent heat resistance and dielectric properties and a good molded appearance, and a prepreg and a metal-clad laminate using the same.

The resin composition of the present invention comprises: a cyanate ester resin (a) having two or more cyanate groups in the molecule, a bisphenol A type epoxy resin (b) having two or more epoxy groups in the molecule, a novolak type epoxy resin (c) having two or more epoxy groups in the molecule, a brominated polycarbonate oligomer (d), an oligomer (e) of styrene and/or substituted styrene, a spherical silica (f) having an average particle diameter of 3 μm or less, and a wetting dispersant (g).

In addition, in the aspect of the present invention, it is preferable that the wetting and dispersing agent (g) is contained in an amount of 2 to 7 mass% with respect to the spherical silica (f) having an average particle diameter of 3 μm or less.

Preferably, the resin composition contains 25 to 65 parts by mass of the spherical silica (f) having an average particle diameter of 3 μm or less per 100 parts by mass of the resin solid content in the resin composition.

In the embodiment of the present invention, it is preferable that the cyanate ester resin (a) is contained in an amount of 25 to 65 parts by mass based on 100 parts by mass of the resin solid content in the resin composition.

In the embodiment of the present invention, it is preferable that the bisphenol a-type epoxy resin (b) is contained in an amount of 5 to 40 parts by mass based on 100 parts by mass of the resin solid content in the resin composition.

In an embodiment of the present invention, it is preferable that the bisphenol a-type epoxy resin (b) comprises a brominated bisphenol a-type epoxy resin.

In the embodiment of the present invention, it is preferable that the novolac-type epoxy resin (c) is contained in an amount of 5 to 30 parts by mass based on 100 parts by mass of the resin solid content in the resin composition.

In addition, in the embodiment of the present invention, it is preferable that the brominated polycarbonate oligomer (d) is contained in an amount of 3 to 25 parts by mass based on 100 parts by mass of a resin solid content in the resin composition.

In the embodiment of the present invention, it is preferable that the oligomer (e) of styrene and/or substituted styrene is contained in an amount of 3 to 20 parts by mass based on 100 parts by mass of the resin solid content in the resin composition.

Further, according to another aspect of the present invention, there are provided a prepreg obtained by impregnating or coating a substrate with the above resin composition, and a metal foil-clad laminate obtained by laminating and molding at least one or more of the prepregs stacked on each other and having a metal foil disposed on one surface or both surfaces thereof.

The prepreg obtained from the resin composition of the present invention and the metal-clad laminate obtained by curing the prepreg are excellent in dielectric characteristics and heat resistance and also good in molded appearance, and therefore are particularly suitable for a multilayer printed circuit board material for high-layer and high-frequency applications, and have extremely high industrial applicability.

Detailed Description

The resin composition of the present invention contains the following as essential components: a cyanate ester resin (a) having two or more cyanate groups in the molecule, a bisphenol A type epoxy resin (b) having two or more epoxy groups in the molecule, a novolak type epoxy resin (c) having two or more epoxy groups in the molecule, a brominated polycarbonate oligomer (d), an oligomer (e) of styrene and/or substituted styrene, a spherical silica (f) having an average particle diameter of 3 μm or less, and a wetting dispersant (g). Hereinafter, each component constituting the resin composition will be described.

< cyanate ester resin (a) >

The cyanate ester resin (a) used in the present invention is not particularly limited as long as it is a compound having two or more cyanate groups in 1 molecule. Specific examples thereof include 1, 3-benzenedicyanate, 1,3, 5-benzenetricyanate, bis (3, 5-dimethyl-4-cyanophenyl) methane, 1, 3-naphthalenedicyanate, 1, 4-naphthalenedicyanate, 1, 6-naphthalenedicyanate, 1, 8-naphthalenedicyanate, 2, 6-naphthalenedicyanate or 2, 7-naphthalenedicyanate, 1,3, 8-naphthalenedicyanate, 4' -biphenyldicyanate, bis (4-cyanophenyl) methane, 2-bis (4-cyanophenyl) propane (2,2-bis (4-cyanophenyl) propane), 2-bis (3, 5-dibromo-4-cyanophenyl) propane, bis (4-cyanophenyl) ether, bis (4-cyanophenyl) sulfide, thioether, Bis (4-cyanatophenyl) sulfone, and cyanate ester resins obtained by reacting various novolak resins such as phenol and naphthol with cyanogen bromide, and the like, and these may be used singly or in admixture of two or more kinds as appropriate. Preferable cyanate ester compounds (a) include 2,2-bis (4-cyanophenyl) propane, bis (3, 5-dimethyl-4-cyanophenyl) methane, phenol novolac type cyanate ester, naphthol aralkyl novolac type cyanate ester, and prepolymers thereof.

The content of the cyanate ester resin (a) in the resin composition is preferably in the range of 25 to 65 parts by mass, and more preferably in the range of 35 to 50 parts by mass, based on 100 parts by mass of the resin solid content in the resin composition. When the content of the cyanate ester resin (a) is not less than the lower limit, the glass transition temperature can be increased and the electrical characteristics, particularly the loss tangent, can be reduced. Further, by setting the upper limit value or less, the decrease in material properties, particularly, moisture absorption heat resistance, during moisture absorption can be suppressed. The term "resin solid content in the resin composition" as used herein means components other than the spherical silica, the wetting dispersant and the solvent contained in the resin composition. In the present specification, "the resin solid content in the resin composition" means the above-mentioned components.

< bisphenol A type epoxy resin (b) >)

The bisphenol a-type epoxy resin (b) used in the present invention is not particularly limited as long as it is a bisphenol a-type epoxy resin having two or more epoxy groups in 1 molecule. In the present invention, the bisphenol a type epoxy resin (b) preferably contains a brominated bisphenol a type epoxy resin.

The content of the bisphenol a-type epoxy resin (b) in the resin composition is preferably in the range of 5 to 40 parts by mass, and more preferably in the range of 10 to 30 parts by mass, based on 100 parts by mass of the resin solid content in the resin composition. By setting the content of the bisphenol a type epoxy resin (b) to the lower limit or more, the electrical characteristics, particularly the loss tangent, can be reduced. Further, by setting the upper limit value or less, the material properties at the time of moisture absorption, particularly, moisture absorption heat resistance can be improved.

< novolak type epoxy resin (c) >)

The novolak type epoxy resin (c) used in the present invention is not particularly limited as long as it is a novolak type epoxy resin having two or more epoxy groups in 1 molecule. Specific examples thereof include phenol novolak epoxy resins, brominated phenol novolak epoxy resins, cresol novolak epoxy resins, bisphenol a novolak epoxy resins, phenol aralkyl novolak type epoxy resins, biphenyl aralkyl novolak type epoxy resins, naphthol aralkyl novolak type epoxy resins, phosphorus-containing novolak type epoxy resins, cyclopentadiene type epoxy resins, isocyanate-modified epoxy resins, and the like. Of these, phenol novolac epoxy resins, brominated phenol novolac epoxy resins, and cresol novolac epoxy resins are preferable. One or a mixture of two or more of the above novolak type epoxy resins can be used.

The content of the novolac-type epoxy resin (c) in the resin composition is preferably in the range of 5 to 30 parts by mass, and more preferably 10 to 20 parts by mass, based on 100 parts by mass of the resin solid content in the resin composition. By setting the content of the novolak type epoxy resin (c) to the lower limit or more, the material properties at the time of moisture absorption, particularly, moisture absorption heat resistance can be improved. Further, by setting the value to the upper limit or less, the electrical characteristics, particularly the loss tangent, can be reduced.

The resin composition of the present invention may contain epoxy resins other than the epoxy resins (b) and (c). Specific examples of such epoxy resins include bisphenol F type epoxy resins, trisphenol methane type epoxy resins, polyfunctional phenol type epoxy resins, naphthalene type epoxy resins, biphenyl type epoxy resins, and the like. These epoxy resins may be used alone or in a mixture of two or more thereof as appropriate.

< brominated polycarbonate oligomer (d) >)

The brominated polycarbonate oligomer (d) used in the present invention is not particularly limited as long as it is a bromine atom-containing oligomer having a polycarbonate structure. The molecular weight of the brominated polycarbonate oligomer (d) is not particularly limited, and in the present invention, the mass average molecular weight is preferably 500 to 3000.

The content of the brominated polycarbonate oligomer (d) in the resin composition is not particularly limited, but is preferably in the range of 3 to 25 parts by mass, and more preferably in the range of 5 to 20 parts by mass, relative to 100 parts by mass of the resin solid content in the resin composition. When the content of the brominated polycarbonate oligomer (d) is not less than the lower limit, the dielectric constant and the loss tangent can be reduced. Further, by setting the upper limit value or less, the decrease in heat resistance can be suppressed.

Oligomers of styrene and/or substituted styrene (e) >

The oligomer (e) of styrene and/or substituted styrene used in the present invention is a compound or resin having no branched structure as described below: the aromatic vinyl copolymer is obtained by polymerizing one or more aromatic vinyl compounds consisting of styrene, vinyl toluene, alpha-methyl styrene and the like, and the number average molecular weight of the polymer obtained by polymerization is 178-800, the average aromatic nucleus number is 2-6, the total content of 2-6 aromatic nuclei is more than 50 mass percent, and the boiling point is more than 300 ℃.

The content of the styrene and/or substituted styrene oligomer (e) in the resin composition is not particularly limited, but is preferably in the range of 3 to 20 parts by mass, and more preferably in the range of 5 to 15 parts by mass, relative to 100 parts by mass of the resin solid content in the resin composition. By setting the content of the oligomer (e) to the lower limit or more, the dielectric constant and the loss tangent can be reduced. Further, by setting the upper limit value or less, the material properties at the time of moisture absorption, particularly, moisture absorption heat resistance can be improved.

< spherical silica (f) >)

Examples of the spherical silica (f) used in the present invention include spherical fused silica and spherical synthetic silica, and these can be used alone or in a mixture of two or more kinds as appropriate. As the average particle diameter of the spherical silica (f), spherical silica having an average particle diameter of 3 μm or less is used, and spherical silica having an average particle diameter of 0.1 to 1 μm is particularly preferably used.

The content of the spherical silica (f) in the resin composition is not particularly limited, but is preferably in the range of 25 to 65 parts by mass, and more preferably in the range of 35 to 50 parts by mass, relative to 100 parts by mass of the resin solid content in the resin composition. By setting the content of the spherical silica (f) to the lower limit or more, the electrical characteristics, particularly the loss tangent, can be reduced. Further, by setting the content to the upper limit or less, a resin composition having good drilling processability and flow characteristics at the time of molding can be obtained. When the average particle size of the spherical silica exceeds 3 μm and the content of the spherical silica exceeds the upper limit of the above range, problems such as damage when using a small-diameter drill and deterioration of flow characteristics during molding may occur. When the content of the spherical silica is not more than the lower limit of the above range, the electrical characteristics, particularly the loss tangent, increase.

The spherical silica used in the present invention may be surface-treated. The surface treatment may be applied as long as it is a treatment generally used for laminate applications, and examples thereof include epoxysilane treatment, aminosilane treatment and the like.

< wetting dispersant (g) >

Examples of the wetting dispersant (g) used in the present invention include salts of long-chain polyaminoamides with high-molecular-weight acid esters, salts of high-molecular-weight polycarboxylic acids, salts of long-chain polyaminoamides with polar acid esters, high-molecular-weight unsaturated acid esters, polymer copolymers, modified polyurethanes, modified polyacrylates, and the like, and these can be used alone or in a mixture of two or more thereof as appropriate. Of these, a high-molecular copolymer based on a urethane structure is preferable because a large amount of pigment affinic groups are adsorbed on the filler surface, aggregation between fillers can be prevented, and wetting dispersants entangle with each other, settling of fillers can be prevented, and the like. As the wetting dispersant, commercially available wetting dispersants can be used, and examples thereof include Disperbyk-116, 161 and 184 manufactured by BYK-Chemie Japan Co., Ltd. These may be used alone or in a mixture of two or more thereof as appropriate.

The content of the wetting dispersant (g) in the resin composition is preferably 2 to 7 mass% of the content of the spherical silica (f) contained in the resin composition. By setting the content of the wetting dispersant (g) to the lower limit or more, the dispersion of the resin and the spherical silica in the resin composition can be improved, and molding unevenness can be suppressed. Further, by setting the upper limit value or less, the decrease in heat resistance can be suppressed.

< other ingredients >

If necessary, a curing accelerator may be added to the resin composition of the present invention. The curing accelerator is not particularly limited as long as it is a known and commonly used one. Typical examples thereof include organic metal salts such as copper, zinc, cobalt and nickel, imidazoles and derivatives thereof, and tertiary amines, and specifically, zinc octoate and the like can be used.

< method for producing resin composition >

The resin composition of the present invention can be produced by a conventionally known method of mixing the above components. For example, a resin composition can be produced by adding a cyanate ester resin (a), a bisphenol a type epoxy resin (b), a novolac type epoxy resin (c), a brominated polycarbonate oligomer (d), a styrene and/or substituted styrene oligomer (e), spherical silica (f) having an average particle diameter of 3 μm or less, and a wetting dispersant (g) to a solvent in this order and sufficiently stirring them.

The solvent of the present invention used for producing the resin composition is not particularly limited as long as it can dissolve a mixture of the cyanate ester resin (a), the bisphenol a type epoxy resin (b), and the novolac type epoxy resin (c). Specifically, acetone, methyl ethyl ketone, methyl cellosolve, propylene glycol methyl ether and its acetate, toluene, xylene, dimethylformamide and the like can be used, and these can be used singly or in a mixture of two or more kinds as appropriate.

< prepreg >

The prepreg of the present invention is formed by impregnating or coating the resin composition described above into a substrate. As the base material, a known base material used for various materials for printed wiring boards can be used. Examples thereof include inorganic fibers such as E glass, D glass, S glass, T glass, and NE glass, and organic fibers such as polyimide, polyamide, and polyester, but are not limited thereto and may be appropriately selected depending on the intended use and performance.

Examples of the shape of the substrate include woven fabric and nonwoven fabric. The thickness of the base material is not particularly limited, but is usually about 0.02 to 0.2 mm. In addition, a substrate surface-treated with a silane coupling agent or the like, or a substrate subjected to physical fiber-opening treatment can be suitably used from the viewpoint of moisture absorption and heat resistance.

The method for producing the prepreg of the present invention is not particularly limited as long as the prepreg is obtained by combining a resin composition comprising a cyanate ester resin (a), a bisphenol a-type epoxy resin (b), a novolac-type epoxy resin (c), a brominated polycarbonate oligomer (d), a styrene and/or substituted styrene oligomer (e), spherical silica (f) having an average particle diameter of 3 μm or less, and a wetting dispersant (g) with a base material. For example, the prepreg can be formed by impregnating or coating the base material with the above resin composition and then heating to semi-cure (B-stage) the resin. The B-staging can be carried out by heating the resin composition impregnated or coated on the base material in a dryer at 100 to 200 ℃ for 1 to 30 minutes, for example. The amount of the resin composition (including spherical silica) in the prepreg is preferably in the range of 30 to 90 mass% relative to the substrate.

< Metal foil clad laminate >

The metal foil-clad laminate of the present invention is a laminate obtained by laminating and molding the prepreg. Specifically, the prepreg is a laminated sheet obtained by laminating one or more sheets of the prepreg, and if necessary, arranging a metal foil such as copper or aluminum on one surface or both surfaces thereof, and then laminating and molding the laminated sheet. The metal foil to be used is not particularly limited as long as it is a metal foil used for a printed circuit board material, and is preferably a known copper foil such as a rolled copper foil or an electrolytic copper foil. The thickness of the metal foil is preferably 3 to 70 μm, preferably 5 to 18 μm.

The conditions for lamination can be those used for usual laminates and multilayer boards for printed wiring boards. For example, a multistage press, a multistage vacuum press, a continuous press, an autoclave press, etc. are usually used, and the temperature is 150 to 300 ℃ and the pressure is 2 to 100kgf/cm²And the heating time is within the range of 0.05-5 hours. Alternatively, a prepreg may be combined with a separately prepared inner layer circuit board and laminated to form a multilayer board.

Examples

The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to these examples.

< production of double-sided copper-clad laminate >

Example 1

40 parts by mass of a prepolymer of 2,2-bis (4-cyanophenyl) propane (CA210, manufactured by Mitsubishi gas chemistry), 14 parts by mass of a brominated bisphenol A type epoxy resin (EPICLON153, manufactured by DIC), 15 parts by mass of a brominated bisphenol A type epoxy resin (DER515, manufactured by Dow Chemical Japan Ltd.), 12 parts by mass of a cresol novolak type epoxy resin (N680, manufactured by DIC), 9 parts by mass of a brominated polycarbonate oligomer (FG8500, mass average molecular weight 3000, Br content 58%, manufactured by Kimura), 10 parts by mass of a low molecular weight polystyrene (PICCOLAS TIC A-5, manufactured by Eastman Chemical Company, U.S.), 55 parts by mass of a spherical synthetic silica (SC2050, average particle size 0.5 μm, manufactured by Admatech Co., Ltd.), 1.5 parts by mass of a wetting dispersant (Disperbyk-161, BYK-Chemie, manufactured by Japan Co., Ltd.), 1.5 parts by mass of a wetting dispersant (Disperbyk-161, manufactured by Mitsubishi Co., Ltd.), 0.02 part by mass of zinc octoate was stirred and mixed to obtain a varnish.

The varnish thus obtained was diluted with methyl ethyl ketone and impregnated into an E glass cloth having a thickness of 0.08mm, and the mixture was heated at 160 ℃ for 8 minutes to obtain a prepreg having a resin composition amount of 54 mass%. Next, eight sheets of the prepregs were stacked, and 18 μm electrolytic copper foils were placed on the upper and lower surfaces of the stacked product at a temperature of 200 ℃ under a surface pressure of 30kgf/cm²Pressing for 160 minutes to obtain a double-sided copper-clad laminate with a thickness of 0.8 mm.

Example 2

A varnish was obtained by stirring and mixing 45 parts by mass of a prepolymer of 2,2-bis (4-cyanophenyl) propane (CA210), 16 parts by mass of a brominated bisphenol a type epoxy resin (EPICLON153), 8 parts by mass of a brominated bisphenol a type epoxy resin (DER515), 15 parts by mass of a cresol novolak type epoxy resin (N680), 9 parts by mass of a brominated polycarbonate oligomer (FG8500), 7 parts by mass of an α -methylstyrene oligomer (Crystalex 3085, mass average molecular weight: 664, manufactured by Eastman Chemical Company, usa), 45 parts by mass of spherical synthetic silica (S C2050), 1 part by mass of a wetting dispersant (Disperbyk-184, BYK-Chemie Japan co., ltd.), and 0.02 part by mass of zinc octoate. A double-sided copper-clad laminate having a thickness of 0.8mm was obtained in the same manner as in example 1, except that this varnish was used.

Example 3

A varnish was produced in the same manner as in example 2 except that Disperbyk-161 (manufactured by BYK-Chemie Japan Co., Ltd.) was used as a wetting dispersant in place of Disperbyk-184 in the production of the varnish, and a double-sided copper-clad laminate having a thickness of 0.8mm was obtained in the same manner as in example 2.

Example 4

A varnish was produced in the same manner as in example 3 except that the blending amount of the wetting and dispersing agent in example 3 was changed from 1 part by mass to 3 parts by mass, and a double-sided copper-clad laminate having a thickness of 0.8mm was obtained in the same manner as in example 3.

Example 5

A varnish was produced in the same manner as in example 2 except that 2 parts by mass of Disperbyk-116 (manufactured by BYK-Chemie Japan co., ltd.) was used in place of 1 part by mass of Disperbyk-184 as a wetting dispersant in the preparation of the varnish, and a double-sided copper-clad laminate having a thickness of 0.8mm was obtained in the same manner as in example 2.

Example 6

A varnish was obtained by stirring and mixing 50 parts by mass of a prepolymer of 2,2-bis (4-cyanophenyl) propane (CA210), 10 parts by mass of a brominated bisphenol A-type Epoxy resin (EPICLON153), 5 parts by mass of a bisphenol A-type Epoxy resin (EPIKOTE828EL, Japan Epoxy Resins Co., Ltd.), 15 parts by mass of a brominated phenol novolak-type Epoxy resin (BREN-S, manufactured by Nippon Chemicals), 10 parts by mass of a brominated polycarbonate oligomer (FG8500), 10 parts by mass of a low-molecular-weight polystyrene (PICCOLASTIC A-5), 25 parts by mass of a spherical fused silica (FB-3SDC, average particle diameter 3 μm, manufactured by the electrochemical industry), 0.5 parts by mass of a wetting dispersant (Disperbyk-161), and 0.02 parts by mass of zinc octylate. A double-sided copper-clad laminate having a thickness of 0.8mm was obtained in the same manner as in example 1, except that this varnish was used.

Example 7

A varnish was obtained by stirring and mixing 35 parts by mass of a prepolymer of 2,2-bis (4-cyanophenyl) propane (CA210), 5 parts by mass of a brominated bisphenol a type epoxy resin (EPICLON153), 5 parts by mass of a brominated bisphenol a type epoxy resin (DER515), 25 parts by mass of a cresol novolak type epoxy resin (N680), 20 parts by mass of a brominated polycarbonate oligomer (FG8500), 10 parts by mass of an α -methylstyrene oligomer (Crystalex 3085), 60 parts by mass of spherical synthetic silica (SC2050), 2 parts by mass of a wetting dispersant (Disperbyk-161), and 0.02 part by mass of zinc octylate. A double-sided copper-clad laminate having a thickness of 0.8mm was obtained in the same manner as in example 1, except that this varnish was used.

Example 8

A varnish was obtained by stirring and mixing 50 parts by mass of a prepolymer of 2,2-bis (4-cyanophenyl) propane (CA210), 17 parts by mass of a brominated bisphenol A-type epoxy resin (EPICLON153), 8 parts by mass of a bisphenol A-type epoxy resin (EPIKOTE828EL), 10 parts by mass of a brominated phenol novolak-type epoxy resin (BREN-S), 5 parts by mass of a brominated polycarbonate oligomer (FG8500), 15 parts by mass of a low molecular weight polystyrene (PICCOLASTICA-5), 45 parts by mass of a spherical synthetic silica (SC2050), 1 part by mass of a wetting dispersant (Disperbyk-184), and 0.02 part by mass of zinc octylate. A double-sided copper-clad laminate having a thickness of 0.8mm was obtained in the same manner as in example 1, except that this varnish was used.

Comparative example 1

A varnish was obtained by stirring and mixing 40 parts by mass of a prepolymer of 2,2-bis (4-cyanophenyl) propane (CA210), 14 parts by mass of a brominated bisphenol a type epoxy resin (EPICLON153), 15 parts by mass of a brominated bisphenol a type epoxy resin (DER515), 12 parts by mass of a cresol novolak type epoxy resin (N680), 9 parts by mass of a brominated polycarbonate oligomer (FG8500), 10 parts by mass of an α -methylstyrene oligomer (Crystalex 3085), 55 parts by mass of spherical synthetic silica (SC2050), and 0.02 parts by mass of zinc octylate. A double-sided copper-clad laminate having a thickness of 0.8mm was obtained in the same manner as in example 1, except that this varnish was used.

Comparative example 2

A varnish was obtained by stirring and mixing 50 parts by mass of a prepolymer of 2,2-bis (4-cyanophenyl) propane (CA210), 20 parts by mass of a brominated bisphenol A-type epoxy resin (EPICLON153), 10 parts by mass of a bisphenol A-type epoxy resin (EPIKOTE828EL), 10 parts by mass of a brominated polycarbonate oligomer (FG8500), 10 parts by mass of a low molecular weight polystyrene (PICCOLATIC A-5), 60 parts by mass of a spherical synthetic silica (SC2050), 2 parts by mass of a wetting dispersant (Disperbyk-161), and 0.02 part by mass of zinc octylate. A double-sided copper-clad laminate having a thickness of 0.8mm was obtained in the same manner as in example 1, except that this varnish was used.

Comparative example 3

A varnish was obtained by stirring and mixing 37 parts by mass of a prepolymer of 2,2-bis (4-cyanophenyl) propane (CA210), 25 parts by mass of a brominated phenol novolak-type epoxy resin (BREN-S), 23 parts by mass of a cresol novolak-type epoxy resin (N680), 10 parts by mass of a brominated polycarbonate oligomer (FG8500), 5 parts by mass of an alpha-methylstyrene oligomer (Crystalex 3085), 50 parts by mass of spherical silica (FB-3SDC), 1 part by mass of a wetting dispersant (Disperbyk-184) and 0.02 part by mass of zinc octylate. A double-sided copper-clad laminate having a thickness of 0.8mm was obtained in the same manner as in example 1, except that this varnish was used.

Comparative example 4

A varnish was obtained by stirring and mixing 50 parts by mass of a prepolymer of 2,2-bis (4-cyanophenyl) propane (CA210), 17 parts by mass of a brominated bisphenol A type epoxy resin (EPICLON153), 5 parts by mass of a bisphenol A type epoxy resin (EPIKOTE828EL), 8 parts by mass of a brominated phenol novolac type epoxy resin (BREN-S), 10 parts by mass of a brominated polycarbonate oligomer (FG8500), 10 parts by mass of a low molecular weight polystyrene (PICCOLASTICA-5), 0.5 part by mass of a wetting dispersant (Disperbyk-161), and 0.02 part by mass of zinc octylate. A double-sided copper-clad laminate having a thickness of 0.8mm was obtained in the same manner as in example 1, except that this varnish was used.

Comparative example 5

A varnish was obtained by stirring and mixing 40 parts by mass of a prepolymer of 2,2-bis (4-cyanophenyl) propane (CA210), 8 parts by mass of a brominated bisphenol A-type epoxy resin (EPICLON153), 22 parts by mass of a brominated bisphenol A-type epoxy resin (DER515), 15 parts by mass of a cresol novolak-type epoxy resin (N680), 10 parts by mass of a brominated polycarbonate oligomer (FG8500), 5 parts by mass of a low molecular weight polystyrene (PICCOLASTIC A-5), 80 parts by mass of a crushed silica having a particle size of 4.9 μm (F S-20, manufactured by the electrochemical industry), 2 parts by mass of a wetting dispersant (Disperbyk-161), and 0.02 part by mass of zinc octylate. A double-sided copper-clad laminate having a thickness of 0.8mm was obtained in the same manner as in example 1, except that this varnish was used.

Comparative example 6

A varnish was obtained by stirring and mixing 45 parts by mass of a prepolymer of 2,2-bis (4-cyanophenyl) propane (CA210), 15 parts by mass of a brominated bisphenol A type epoxy resin (EPICLON153), 17 parts by mass of a brominated bisphenol A type epoxy resin (DER515), 8 parts by mass of a brominated phenol novolac type epoxy resin (BREN-S), 15 parts by mass of an alpha-methylstyrene oligomer (Crystalex 3085), 40 parts by mass of spherical fused silica (SC2050), 1 part by mass of a wetting dispersant (Disperbyk-184), and 0.02 part by mass of zinc octylate. A double-sided copper-clad laminate having a thickness of 0.8mm was obtained in the same manner as in example 1, except that this varnish was used.

Comparative example 7

30 parts by mass of a prepolymer of 2,2-bis (4-cyanophenyl) propane (CA210), 8 parts by mass of a brominated bisphenol A type epoxy resin (EPICLON153), 15 parts by mass of a bisphenol A type epoxy resin (EPIKOTE828EL), 12 parts by mass of a cresol novolak type epoxy resin (N680), 35 parts by mass of a brominated polycarbonate oligomer (FG8500), 55 parts by mass of spherical fused silica (SC2050), 1 part by mass of a wetting dispersant (Disperbyk-161), and 0.02 part by mass of zinc octylate were stirred and mixed to obtain a varnish. A double-sided copper-clad laminate having a thickness of 0.8mm was obtained in the same manner as in example 1, except that this varnish was used.

Comparative example 8

A varnish was produced in the same manner as in example 3 except that the blending amount of the wetting and dispersing agent in example 3 was changed from 1 part by mass to 4 parts by mass, and a double-sided copper-clad laminate having a thickness of 0.8mm was obtained in the same manner as in example 3.

Comparative example 9

A varnish was produced in the same manner as in example 3 except that the blending amount of the wetting and dispersing agent in example 3 was changed from 1 part by mass to 5 parts by mass, and a double-sided copper-clad laminate having a thickness of 0.8mm was obtained in the same manner as in example 3.

< evaluation >

(1) Glass transition temperature

The glass transition temperature of the obtained resin was measured by the DMA method according to JIS C6481 (n = 2).

(2) Dielectric characteristics

After the copper foil of a 0.8mm copper clad laminate was removed by etching, the laminate was cut into a size of 110X 1.0mm, and the value of 1GHz (n =6) was measured by a cavity resonance method (manufactured by Agilent, NETWORK Analyzer 8722 ES). However, the loss tangent is usually not more than 0.0065, and the loss tangent is usually not more than this value.

(3) T-288 (time to delay)

According to IPC TM-650, a test piece (5mm × 5mm × 0.8mm) with 18 μm copper foil was used, and heated to 288 ℃ at a temperature increase rate of 10 ℃/min using a TMA apparatus (manufactured by SII NanoTechnology inc., EXSTAR6000TMA/SS6100), and after the temperature reached 288 ℃, the temperature was kept constant at 288 ℃, and the time from when the temperature reached 288 ℃ until delamination occurred was measured (n = 2). Among them, generally, the delamination occurred for 10 minutes or more was acceptable, and less than 10 minutes was unacceptable (NG).

(4) Moisture absorption and heat resistance

A test piece obtained by etching and removing the entire copper foil having an area of not more than half of one surface of a 60mm × 60mm sample by a pressure cooker tester (PC-3 type, manufactured by Hill manufacturing Co., Ltd.) was treated at 121 ℃ under two atmospheric pressures for 3 hours, and then the change in appearance was visually observed when the test piece was immersed in solder at 260 ℃ for 30 seconds. The moisture absorption heat resistance was evaluated by the same test (n =4) at the ratio of the number of times of occurrence of foaming (number of times of foaming/number of tests).

(5) Damage of drill bit

Copper foils having a thickness of 12 μm were arranged on both surfaces of eight prepregs using E glass cloth having a thickness of 0.1mm and a resin amount of 54 mass%, to manufacture copper-clad laminates having a thickness of 0.8 mm. Using one of the test pieces (510mm × 340mm × 0.8mm), an entry sheet (entry sheet) (LE 800 thickness 0.070mm, manufactured by mitsubishi gas chemical), a drill (MD J492B0.105 × 1.6mm, manufactured by Union Tool co.), a rotational speed of 160krpm, and a feed speed of 1.2 m/min, was machined at a pitch of 0.2mm to 5000 holes using an NC driling machine (H-MARK-20V, manufactured by Hitachi Via machines, ltd.), and the case where no drill was machined into 5000 holes was passed (° o) and the case where a drill was machined into 5000 holes was failed (×) (n = 3).

(6) Uneven forming

After etching the copper foil of the laminate, the laminate was visually evaluated. No forming unevenness (flow streak) was acceptable (∘), and forming unevenness was unacceptable (×) (n = 3).

The evaluation results of the above (1) to (6) are shown in tables 1 and 2 below.

TABLE 1

TABLE 2

From the evaluation results shown in tables 1 and 2, it is understood that the laminates (examples 1 to 10) formed using the resin composition comprising the cyanate ester resin (a), the bisphenol a-type epoxy resin (b), the novolac-type epoxy resin (c), the brominated polycarbonate oligomer (d), the oligomer (e) of styrene and/or substituted styrene, the spherical silica (f) having an average particle diameter of 3 μm or less, and the wetting dispersant (g) are excellent in heat resistance and dielectric characteristics and also in molding appearance as compared with the laminates (comparative examples 1 to 7) formed using the resin composition not containing any one or more of these components.

Claims (11)

1. A resin composition comprising:

a cyanate ester resin (a) having two or more cyanate groups in a molecule;

a bisphenol A-type epoxy resin (b) having two or more epoxy groups in a molecule;

a novolak type epoxy resin (c) having two or more epoxy groups in a molecule;

a brominated polycarbonate oligomer (d);

oligomers of styrene and/or substituted styrene (e);

spherical silica (f) having an average particle diameter of 3 μm or less; and

a wetting dispersant (g);

the wetting and dispersing agent (g) comprises a high-molecular copolymer based on a urethane structure.

2. The resin composition according to claim 1, wherein the wetting dispersant (g) is contained in an amount of 2 to 7 mass% based on the spherical silica (f) having an average particle diameter of 3 μm or less.

3. The resin composition according to claim 1 or 2, wherein the spherical silica (f) having an average particle diameter of 3 μm or less is contained in an amount of 25 to 65 parts by mass based on 100 parts by mass of a resin solid content in the resin composition.

4. The resin composition according to claim 1 or 2, wherein the cyanate ester resin (a) is contained in an amount of 25 to 65 parts by mass based on 100 parts by mass of the resin solid content in the resin composition.

5. The resin composition according to claim 1 or 2, wherein the bisphenol A-type epoxy resin (b) is contained in an amount of 5 to 40 parts by mass based on 100 parts by mass of a resin solid content in the resin composition.

6. The resin composition according to claim 5, wherein the bisphenol A epoxy resin (b) comprises a brominated bisphenol A epoxy resin.

7. The resin composition according to claim 1 or 2, wherein the novolac-type epoxy resin (c) is contained in an amount of 5 to 30 parts by mass based on 100 parts by mass of a resin solid content in the resin composition.

8. The resin composition according to claim 1 or 2, comprising 3 to 25 parts by mass of the brominated polycarbonate oligomer (d) per 100 parts by mass of a resin solid content in the resin composition.

9. The resin composition according to claim 1 or 2, comprising the oligomer (e) of styrene and/or substituted styrene in an amount of 3 to 20 parts by mass based on 100 parts by mass of the resin solid content in the resin composition.

10. A prepreg obtained by impregnating or coating a substrate with the resin composition according to any one of claims 1 to 9.

11. A metal-clad laminate obtained by laminating at least one prepreg according to claim 10, and then arranging metal foils on one or both surfaces of the prepreg, followed by lamination.