JP2017071695A - Resin composition, resin varnish, prepreg, metal-clad laminate, and printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition formed into a printed wiring board which has low thermal expansion coefficient, hardly lowers resin fluidity with time and is excellent in storage stability even when left at normal temperature, and is excellent in dielectric loss tangent, adhesion strength between layers, heat resistance, boiling solder heat resistance and voltage resistance; a resin varnish; prepreg; a metal-clad laminate; and a printed wiring board.SOLUTION: A resin composition contains a reaction product (A) of polyphenylene ether having a hydroxyl group and an epoxy resin, a cyanate resin (B) having two or more cyanate groups in average in one molecule, metallic soap (C), and crushed silica (D). A content of the crushed silica (D) is 20-70 pts.mass with respect to 100 pts.mass of the reaction product (A) and the cyanate resin (B). An average particle size of the crushed silica (D) is 1 μm to 5 μm.SELECTED DRAWING: None

Description

  The present invention relates to a resin composition, a resin varnish, a prepreg, a metal-clad laminate, and a printed wiring board.

  Printed wiring boards are widely used in various fields such as electronic devices, communication devices, and computers. In recent years, especially in small portable devices such as portable communication terminals and notebook PCs, with the increase in the amount of information processing, the integration, multi-functionality, high performance, thinning and miniaturization of mounted semiconductor devices are rapidly increasing. Electronic components such as semiconductor packages mounted on such devices are also becoming thinner and smaller. Along with this, insulating materials such as printed wiring boards used to mount these electronic components have a low dielectric constant and dielectric loss tangent in order to increase signal transmission speed and reduce loss during signal transmission. The coefficient of thermal expansion is required to be low. Furthermore, the printed wiring board is also excellent in interlayer adhesive strength, heat resistance, boiling solder heat resistance and withstand voltage, and is required to have high performance such as miniaturization, multilayering, thinning, and mechanical characteristics of the wiring pattern.

  In Patent Document 1, in order to achieve an excellent glass transition temperature (Tg) (high heat resistance) while maintaining the excellent dielectric properties of polyphenylene ether, at least part of the hydroxyl groups of polyphenylene ether is epoxy resin. Specifically, a resin composition containing a reaction product pre-reacted with an epoxy group, a cyanate ester compound, an organic metal salt, and spherical silica having an average particle diameter of 0.6 μm subjected to epoxy silane surface treatment Has been described.

JP 2014-152283 A

  However, if the prepreg using the resin composition described in Patent Document 1 described above is allowed to stand at room temperature (about 20 to 25 ° C.), the resin fluidity greatly decreases with time, and the prepreg can be used for a long time. Therefore, in order to store it for a relatively long period of time, it is necessary to store it in a refrigerator, which may cause difficulty in handling.

  Accordingly, the present invention has a low coefficient of thermal expansion, and even when left at room temperature, the resin fluidity is less likely to deteriorate with time, and is excellent in storage properties, as well as dielectric loss tangent, interlayer adhesion strength, heat resistance, boiling solder heat resistance and resistance. An object is to provide a resin composition, a resin varnish, a prepreg, a metal-clad laminate, and a printed wiring board that can be a printed wiring board having excellent voltage.

  The resin composition according to the present invention comprises a reaction product (A) of a polyphenylene ether having a hydroxyl group and an epoxy resin, a cyanate resin (B) having an average of 2 or more cyanate groups in one molecule, and a metal soap (C ) And crushed silica (D), and the content of the crushed silica (D) is 20 to 70 parts by mass with respect to 100 parts by mass of the reaction product (A) and the cyanate resin (B). And the average particle size of the crushed silica (D) is 1 μm to 5 μm.

  Moreover, in the resin composition, it is preferable that the surface of the crushed silica (D) is modified with a coupling agent.

  The resin varnish according to the present invention contains the resin composition and a solvent.

  In the resin varnish, the solvent is preferably at least one selected from the group consisting of toluene, cyclohexanone and propylene glycol monomethyl ether acetate.

  The prepreg according to the present invention has a fibrous base material and a semi-cured product of the resin composition, which is filled in the fibrous base material and covers the surface of the fibrous base material. .

  The metal-clad laminate according to the present invention has a cured product of the prepreg and a metal foil on one or both sides of the cured product.

  The printed wiring board which concerns on this invention has a hardened | cured material of the said prepreg, and a conductor pattern on the single side | surface or both surfaces of the said hardened | cured material.

  According to the present invention, the coefficient of thermal expansion is low, and the resin fluidity is unlikely to deteriorate with time even when left at room temperature. Therefore, even if it is not stored in the refrigerator as in the prior art, the usable state of the resin composition, the prepreg and the like can be maintained for a long period of time, and the storage property is excellent. Furthermore, it can be set as the printed wiring board excellent in dielectric loss tangent, interlayer adhesive strength, heat resistance, boiling solder heat resistance, and withstand voltage.

  Hereinafter, an embodiment of the present invention (hereinafter referred to as the present embodiment) will be described.

[Resin composition]
The resin composition according to the present embodiment includes a reaction product (A) of a polyphenylene ether having a hydroxyl group and an epoxy resin, a cyanate resin (B) having an average of two or more cyanate groups in one molecule, and a metal soap ( C) and crushed silica (D), and the content of crushed silica (D) is 20 to 70 parts by mass with respect to 100 parts by mass of the reaction product (A) and cyanate resin (B). Yes, the average particle size of the crushed silica (D) is 1 μm to 5 μm. As a result, the coefficient of thermal expansion is low, and even if it is left at room temperature, the resin fluidity is unlikely to deteriorate over time, and the prepreg and resin composition can be used for a long period of time without being stored in a refrigerator as in the past. It can last and has excellent storage properties. Furthermore, it can be set as the printed wiring board excellent in dielectric loss tangent, interlayer adhesive strength, heat resistance, boiling solder heat resistance, and withstand voltage. Here, in the present invention, the crushed form is basically a state in which fused silica is pulverized, and is not particularly subjected to a shaping process. Moreover, in this invention, an average particle diameter means a volume accumulation average diameter (D50). For the measurement of the average particle diameter, for example, a laser diffraction particle size distribution measuring device MT-3300 (manufactured by Nikkiso Co., Ltd.) can be used.

  Instead of spherical silica having an average particle diameter of 0.6 μm (hereinafter sometimes simply referred to as spherical silica) subjected to epoxy silane surface treatment as described in Patent Document 1, crushed silica (D) is used. Therefore, even if it is left at room temperature, the fluidity of the resin is less likely to decrease over time because the crushed silica (D) reacts with polyphenylene ether and epoxy resin (hereinafter sometimes referred to as preliminary reaction). It is presumed that the main factor is that the reaction product (A) is not easily affected by the secondary hydroxyl group produced when the reaction product (A) is obtained. Spherical silica has a large specific surface area, and not only has a large contact interface with a resin such as the reaction product (A) or cyanate resin (B), but also has a surface treated with epoxysilane. Therefore, it is easily influenced by the secondary hydroxyl group, and the reaction and affinity with the resin increase with time. Therefore, it is presumed that the resin fluidity greatly decreases with time when left at room temperature. On the other hand, when the surface of the crushed silica is not modified with a coupling agent, there are many hydroxyl groups on the surface, and the surface is modified with a coupling agent as described later. In this case, since the specific surface area is small and the contact interface with the resin is small, it is presumed that the resin fluidity is unlikely to deteriorate with time even when left at room temperature because it is not easily affected by the secondary hydroxyl group.

  The resin composition is suitably used as an insulating material for resin sheets, prepregs, metal-clad laminates, printed wiring boards and the like. In particular, since the resin composition has a low coefficient of thermal expansion and excellent resin fluidity, it is suitably used as an insulating material for multilayer printed wiring boards for high frequency applications.

[Reaction product (A)]
The reaction product (A) is a reaction product of a polyphenylene ether (a-1) having a hydroxyl group and an epoxy resin (a-2). Specifically, it is obtained by reacting at least part of the hydroxyl group of polyphenylene ether (a-1) with the epoxy group of epoxy resin (a-2). When the curing reaction with the cyanate resin (B) is performed, the reaction product (A) obtained by reacting the polyphenylene ether (a-1) and the epoxy resin (a-2) in advance is used, so that the polyphenylene ether (a-1) and It can be set as the resin composition and prepreg with a low thermal expansion coefficient rather than the case where an epoxy resin (a-2) is used as it is. Furthermore, it can be set as the printed wiring board excellent in interlayer adhesive strength and heat resistance.

  The polyphenylene ether (a-1) has a hydroxyl group, and preferably has an average of 1.5 to 2 hydroxyl groups in one molecule. Having an average of 1.5 to 2 hydroxyl groups in one molecule means that the average number of hydroxyl groups per molecule (average number of hydroxyl groups) is 1.5 to 2. If the average number of hydroxyl groups is 1.5 or more, the three-dimensional crosslinking is caused by reacting with the epoxy group of the epoxy resin (a-2), so that the adhesion at the time of curing can be improved. Further, when the average number of hydroxyl groups is 2 or less, it is considered that there is no possibility of gelation during the preliminary reaction.

  The average number of hydroxyl groups of polyphenylene ether (a-1) can be seen from the standard value of the polyphenylene ether product used. Examples of the average number of hydroxyl groups of polyphenylene ether (a-1) include the average value of hydroxyl groups per molecule of all the polyphenylene ethers present in 1 mol of polyphenylene ether.

  The number average molecular weight (Mn) of the polyphenylene ether (a-1) is preferably 800 or more and 2000 or less. When the number average molecular weight is 800 or more, dielectric properties, heat resistance, and a high glass transition temperature can be ensured. If the number average molecular weight is 2000 or less, even when a reaction product reacted with a low epoxy group number epoxy resin is contained, the resin flow and phase separation are suppressed, and the moldability is prevented from being deteriorated. Can do.

  The polyphenylene ether having a number average molecular weight of 800 or more and 2000 or less, for example, may be obtained directly by a polymerization reaction, or a polyphenylene ether having a number average molecular weight of 2000 or more is mixed with a phenolic compound and radical initiation in a solvent. It may be obtained by redistribution reaction in the presence of an agent.

  The number average molecular weight (Mn) of the polyphenylene ether (a-1) can be measured using, for example, gel permeation chromatography.

  Examples of the polyphenylene ether (a-1) include polyphenylene ether and poly (2,6-dimethyl-1,4-phenylene) composed of 2,6-dimethylphenol and at least one of bifunctional phenol and trifunctional phenol. Oxides) and the like containing polyphenylene ether as a main component. Among these, polyphenylene ether composed of 2,6-dimethylphenol and at least one of bifunctional phenol and trifunctional phenol is preferable. Examples of the bifunctional phenol include tetramethylbisphenol A.

  The epoxy resin (a-2) has an epoxy group, and preferably has an average of 2 to 2.3 epoxy groups in one molecule. When the average number of epoxy groups is within this range, the reaction product with polyphenylene ether (a-1) can be favorably produced while maintaining the heat resistance of the cured product.

  Examples of the epoxy resin (a-2) include dicyclopentadiene type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, naphthalene type epoxy resin, biphenyl type epoxy resin and the like. . These may be used alone or in combination of two or more. Among these, dicyclopentadiene type epoxy resins are particularly preferably used from the viewpoint of improving dielectric properties. Further, bisphenol A type epoxy resin and bisphenol F type epoxy resin are preferably used from the viewpoint of good compatibility with polyphenylene ether. In addition, although it is preferable that a resin composition does not contain a halogenated epoxy resin from a heat resistant viewpoint, as long as the effect of this invention is not impaired, you may mix | blend as needed.

  The average number of epoxy groups of the epoxy resin (a-2) can be understood from the standard value of the epoxy resin product used. Specific examples of the number of epoxy groups in the epoxy resin include an average value of epoxy groups per molecule of all epoxy resins present in 1 mol of the epoxy resin.

  The epoxy resin (a-2) preferably has a solubility in toluene of 10% by mass or more at 25 ° C. Thereby, the heat resistance of hardened | cured material is fully improved, without inhibiting the outstanding dielectric property which polyphenylene ether (a-1) has. This is considered to be because the compatibility with the polyphenylene ether (a-1) is relatively high and, therefore, it easily reacts uniformly with the polyphenylene ether (a-1).

  The reaction product (A) can be obtained, for example, by reacting as follows. First, a polyphenylene ether (a-1) and an epoxy resin (a-2) are made into about 10 to 60 minutes so that a polyphenylene ether (a-1) and an epoxy resin (a-2) may become a predetermined ratio. The mixture is stirred and mixed in an organic solvent having a solid content concentration of about 50 to 70%. And after mixing polyphenylene ether (a-1) and epoxy resin (a-2), it is made to heat at 80-110 degreeC for 2 to 12 hours, and polyphenylene ether (a-1) and epoxy resin (a- 2) is reacted. Thereby, a reaction product (A) is obtained. The organic solvent is not particularly limited as long as it dissolves polyphenylene ether (a-1), epoxy resin (a-2) and the like and does not inhibit these reactions, and examples thereof include toluene.

  The ratio of the polyphenylene ether (a-1) to the epoxy resin (a-2) is the epoxy group / hydroxyl group as the molar ratio of the hydroxyl group of the polyphenylene ether (a-1) to the epoxy group of the epoxy resin (a-2). Is preferably 3 to 6, more preferably about 3.5 to 5.5. If the molar ratio is in the above range, both ends of the polyphenylene ether (a-1) can be efficiently capped. Furthermore, when the viscosity of the reaction product (A) is lowered, the viscosity of a resin varnish or prepreg described later can be lowered, and the productivity is considered to be improved.

  When the polyphenylene ether (a-1) and the epoxy resin (a-2) are reacted, a curing accelerator may be mixed into the mixture of the polyphenylene ether (a-1) and the epoxy resin (a-2). . The curing accelerator is not particularly limited as long as it can accelerate the reaction between the hydroxyl group of polyphenylene ether (a-1) and the epoxy group of epoxy resin (a-2). For example, octanoic acid, Organic metal salts of organic acids such as stearic acid, acetylacetonate, naphthenic acid, and salicylic acid, such as Zn, Cu, and Fe; 1,8-diazabicyclo [5.4.0] undecene-7 (DBU), triethylamine, And tertiary amines such as triethanolamine; imidazoles such as 2-ethyl-4-imidazole (2E4MZ) and 4-methylimidazole; triphenylphosphine (TPP), tributylphosphine, tetraphenylphosphonium, tetraphenylborate, etc. And organic phosphines. These may be used alone or in combination of two or more. Among these, imidazoles, particularly 2-ethyl-4-imidazole, is particularly preferably used because it can shorten the reaction time and further suppress polymerization between epoxy resins (self-polymerization of epoxy resins). It is done. Moreover, the content of the curing accelerator is preferably 0.05 to 1 part by mass with respect to 100 parts by mass in total of the polyphenylene ether (a-1) and the epoxy resin (a-2). When the content of the curing accelerator is within the above range, the reaction between the hydroxyl group of the polyphenylene ether (a-1) and the epoxy group of the epoxy resin (a-2) does not take time, and the reaction is controlled. Easy to gel and difficult to gel.

  In consideration of reaction efficiency and viscosity (manufacturability), the solid content concentration during the reaction is preferably about 50 to 70%.

[Cyanate resin (B)]
The cyanate resin (B) has an average of two or more cyanate groups in one molecule. Thereby, the heat resistance of hardened | cured material can be improved. Having an average of 2 or more cyanate groups in one molecule means a compound having an average number of cyanate groups per molecule (average number of cyanate groups) of 2 or more. The average number of cyanate groups is the average value of cyanate groups per molecule of all cyanate resins present in 1 mol of cyanate resin. The average number of cyanate groups can be determined from the standard value of the product of the cyanate resin used.

  Examples of the cyanate resin (B) include 2,2-bis (4-cyanatephenyl) propane (bisphenol A type cyanate resin), bis (3,5-dimethyl-4-cyanatephenyl) methane, and 2,2-bis. Aromatic cyanate ester compounds such as (4-cyanatephenyl) ethane or derivatives thereof. These may be used alone or in combination of two or more.

  The resin composition preferably further contains an epoxy resin (e). As with the epoxy resin (a-2), the epoxy resin (e) preferably has an average of 2 to 2.3 epoxy groups in one molecule. Examples of the epoxy resin (e) include dicyclopentadiene type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, naphthalene type epoxy resin, and biphenyl type epoxy resin. These may be used alone or in combination of two or more. In this case, the epoxy resin (e) may be the same as or different from the epoxy resin (a-2). From the viewpoint of improving the dielectric properties, a dicyclopentadiene type epoxy resin is preferably used. In addition, as the epoxy resin (e), in addition to an epoxy resin having an average of 2 to 2.3 epoxy groups in one molecule, a polyfunctional type such as a cresol novolac type epoxy resin (an average of 2.3 in one molecule). An epoxy resin having more than one epoxy group) can also be used.

  When a dicyclopentadiene type epoxy resin is included as the epoxy resin (a-2) and / or the epoxy resin (e), the dicyclopentadiene type is used with respect to the total mass of the epoxy resin (a-2) and the epoxy resin (e). It is preferable to contain so that the epoxy resin may be 50 mass% or more. Thereby, an insulating material having better dielectric properties can be obtained.

  The blending ratio of the resin component is, for example, 100 parts by mass of the reaction product (A) (polyphenylene ether (a-1) and epoxy resin (a-2)), cyanate resin (B) and epoxy resin (e). 10 to 40 parts by mass of polyphenylene ether (a-1), epoxy resin (a-2) and epoxy resin (e) are combined. It is preferable that 20-60 mass parts (when the compounding of epoxy resin (e) is 0, 20-60 mass parts of epoxy resin (a-2)) and 20-40 mass parts of cyanate resin (B). Thereby, it is thought that the outstanding dielectric property, heat resistance, and adhesiveness (adhesiveness) can be made compatible. Hereinafter, the resin component includes a reaction product (A) (polyphenylene ether (a-1), epoxy resin (a-2)), cyanate resin (B), and, if necessary, an epoxy resin (e). Say.

  The resin composition may further contain a halogen flame retardant or a non-halogen flame retardant. Thereby, a flame retardance can be improved. When a halogen-based flame retardant is used, flame retardancy can be imparted, the glass transition temperature of the cured product is unlikely to decrease, and a significant decrease in heat resistance is unlikely to occur. When a halogen-based flame retardant is used, flame retardancy can be easily imparted even when a dicyclopentadiene type epoxy resin that is difficult to impart flame retardancy is used.

  The halogen flame retardant is preferably one that does not dissolve and disperses in the resin varnish described below. Examples of the halogen flame retardant include ethylene dipentabromobenzene, ethylene bistetrabromoimide, decabromodiphenyl oxide, tetradecabromodiphenoxybenzene having a melting point of 300 ° C. or higher. By using such a halogen-based flame retardant, it is considered that elimination of halogen at high temperatures can be suppressed, and a decrease in heat resistance can be suppressed.

  The blending ratio of the halogen-based flame retardant is preferably from the viewpoint of flame retardancy and heat resistance so that the halogen concentration is contained in the resin component of the total amount at a ratio of about 5 to 30% by mass.

[Metal soap (C)]
The resin composition contains metal soap (C) as a curing accelerator. Examples of the metal soap (C) include organic acids such as octylic acid, naphthenic acid, stearic acid, lauric acid, ricinoleic acid and acetyl acetate, and metals such as zinc, copper, cobalt, lithium, magnesium, calcium and barium. An organic metal salt made of Among them, copper naphthenate is preferably used because it has a low cyanate ester trimerization activity and has a relatively good pot life of resin varnish and prepreg (while maintaining heat resistance). The metal soap (C) may be used alone or in combination of two or more.

  The metal soap (C) content is preferably 0.001 to 1 part by mass with respect to 100 parts by mass of the total amount of the reaction product (A) and the cyanate resin (B). If the content of the metal soap (C) is within the above range, the effect of accelerating curing can be enhanced, the high heat resistance of the cured product and the glass transition temperature can be secured, and a prepreg having no problem in moldability can be produced. It becomes easy to do.

[Fractured silica (D)]
The resin composition contains crushed silica (D). The content of crushed silica (D) is 20 to 70 parts by mass with respect to 100 parts by mass of reaction product (A) and cyanate resin (B), and the average particle size of crushed silica (D) is 1 μm to 5 μm. Thereby, it is possible to obtain a resin composition or a prepreg having a low coefficient of thermal expansion and excellent in storability because the resin fluidity hardly deteriorates with time even when left at room temperature.

  The crushed silica (D) is crushed silica particles, and is obtained, for example, by pulverizing fused silica or crystalline silica mined as ore. Since the crushed silica (D) is crushed silica particles, it can be obtained at a lower cost than the spherical silica particles, and is excellent in cost.

  The average particle size of the crushed silica (D) is 1 μm to 5 μm, preferably 1 μm to 3 μm, more preferably 1.5 μm to 2.5 μm. If the average particle size of the crushed silica is less than 1 μm, it may not be possible to obtain a resin composition or prepreg having excellent storage properties. If the average particle size of the crushed silica is more than 5 μm, it may not be possible to obtain a printed wiring board with excellent withstand voltage.

  Content of crushed silica (D) is 20-70 mass parts with respect to 100 mass parts of reaction product (A) and cyanate resin (B), Preferably it is 30-65 mass parts, More preferably, it is 40. -65 parts by mass. When the content of crushed silica (D) exceeds 70 parts by mass, there is a possibility that a printed wiring board excellent in interlayer adhesive strength, heat resistance, boiling solder heat resistance and voltage resistance cannot be obtained. When the content of the crushed silica (D) is less than 20 parts by mass, the degree of the crushed silica (D) contributing to the low thermal expansion coefficient is too small, and the resin composition or prepreg has a low thermal expansion coefficient. There is a risk that it will not be possible.

  The surface of the crushed silica (D) is preferably modified with a coupling agent. That is, the surface of the crushed silica (D) is preferably subjected to a coupling treatment. Thereby, it can be set as the printed wiring board which is more excellent in heat resistance. Further, the crushed silica (D) is difficult to absorb moisture even in a high temperature or high humidity environment. Therefore, even when crushed silica (D) that has been left (stored) at room temperature for a long period of time is used as a material for the resin composition, it becomes difficult for moisture to be brought into the resin composition, and crushed silica (D) in a dry state. Can maintain the same varnish gel time. As a result, depending on the storage state of the crushed silica (D), the glass transition temperature and dielectric properties of the cured product are unlikely to deteriorate with time, and the glass transition temperature and dielectric properties are stable and excellent. Here, the dry crushed silica (D) refers to crushed silica (D) having a water content of less than 0.1% measured by the Karl Fischer method.

  Examples of the coupling agent include silane coupling agents such as β-ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, hexamethyldisilazane, and dimethyldichlorosilane. Alternatively, a known treatment agent such as silicone oil can be used. Examples of the method for coupling the surface of the crushed silica (D) include known methods such as a dry treatment method and a wet method. The surface-treated crushed silica (D) is available as a commercial product, and examples thereof include “Megasil 525RCS” manufactured by Sibelco Japan Co., Ltd.

The specific surface area of the crushed silica (D) is preferably from 1.3 m ² / g Ultra 12.0m less than ² / g, more preferably 1.5 m ² / g or more 10.5 m ² / g or less, more preferably 2 It is not less than 0.0 m ² / g and not more than 6.1 m ² / g. If the specific surface area of the crushed silica (D) is within the above range, the contact interface with the resin such as the reaction product (A) or cyanate resin (B) becomes smaller, and the surface is modified by the coupling agent. Even if it is, it can be set as the resin composition, prepreg, etc. which are more excellent by storage property.

Further, the specific surface area of the crushed silica (D) is preferably 0.1 m ² / g or more and 15 m ² / g or less from the viewpoint of further improving the drill workability of the cured product, and is 0 from the economical point of view. more preferably .1m ² / g or more ^{15 m} 2 / g or less, and even more preferably less than 1.3 m ² / g ultra ^12m 2 / g. When the specific surface area of the crushed silica is 0.1 m ² / g or more, when a metal-clad laminate is manufactured using the resin composition, the drillability of the metal-clad laminate is improved. it can. In other words, in general, when crushed silica is used, it is thought that drilling workability will be significantly reduced, such as when the drill blade is likely to be worn when drilling a metal-clad laminate with a drill, compared to when spherical silica is used. However, wear of a drill blade is greatly improved by using crushed silica having a specific surface area of 0.1 m ² / g or more together with molybdenum compound particles described later. On the other hand, the crushed silica has a specific surface area of 15 m ² / g or less, thereby suppressing the thickening of the resin varnish and suppressing the increase of the melt viscosity at the time of thermoforming, resulting in a resin flowability in a suitable range. Formability when producing a metal-clad laminate is good. As a result, it is possible to prevent the manufacture of the prepreg from being difficult and the void (cavity) from remaining in the insulating layer of the metal-clad laminate. The specific surface area can be measured by the BET method.

  The resin composition may contain molybdenum compound particles. Molybdenum compound particles are inorganic particles having at least a molybdenum compound in the surface layer portion. When the molybdenum compound particles are used, the molybdenum compound functions as a lubricant, whereby wear of the drill due to the crushed silica is suppressed, and drill workability can be improved. Molybdenum compound particles may be composed entirely of molybdenum compounds, or may be particles having a surface on which a molybdenum compound is supported or coated using an inorganic filler made of another material as a carrier. . In addition, it is thought that the molybdenum compound which exists in the surface layer part of molybdenum compound particle | grains acts mainly on suppression of wear of a drill. Therefore, in order to obtain the effect of improving the drilling workability with a small amount of the molybdenum compound, it is preferable to use in the form of particles having a molybdenum compound on the surface of an inorganic filler made of another material, as in the latter. In general, a molybdenum compound has a specific gravity larger than that of an inorganic filler such as silica and has a large specific gravity difference from a resin component. Therefore, also from the viewpoint of dispersibility in the resin composition, like the latter, it is preferable to use in the form of particles having a molybdenum compound on the surface of an inorganic filler made of another material. As the inorganic filler used as the carrier, talc, aluminum hydroxide, boehmite, magnesium hydroxide, silica and the like that are usually used as inorganic fillers for metal-clad laminates can be suitably used. The average particle size of the carrier is preferably 0.05 μm or more. Such molybdenum compound particles are available as commercial products, such as Chem Card manufactured by Sherwin Williams.

Examples of the molybdenum compound constituting the molybdenum compound particles include molybdenum oxides such as molybdenum trioxide; zinc molybdate, calcium molybdate, magnesium molybdate, ammonium molybdate, barium molybdate, sodium molybdate, potassium molybdate, And molybdate compounds such as phosphomolybdic acid and ammonium phosphomolybdate; and molybdenum compounds such as molybdenum boride, molybdenum disilicide, molybdenum nitride, and molybdenum carbide. These may be used alone or in combination of two or more. Among these, one or more selected from the group consisting of zinc molybdate (ZnMoO ₄ ), calcium molybdate (CaMoO ₄ ), and magnesium molybdate (MgMoO ₄ ) from the viewpoints of chemical stability, moisture resistance, and insulation. Are preferred. Only one of these may be used, two may be used in combination, or all three may be used.

  The content of the molybdenum compound particles is preferably 0.1 parts by mass or more and 10 parts by mass or less, more preferably 0.1 parts by mass or more and 7 parts by mass or less, and further preferably 0.1 parts by mass with respect to 100 parts by mass of the resin component. It is not less than 5 parts by mass. If the content of the molybdenum compound particles is within the above range, it can sufficiently function as a lubricant and improve the drillability of the metal-clad laminate. Furthermore, the influence on the heat resistance and copper foil peel strength of the metal-clad laminate can be suppressed. Further, since the molybdenum compound has low oil absorption, it does not have a practical adverse effect on the resin fluidity during molding or the like.

  A molybdenum compound is contained in the molybdenum compound particles. The total content of the molybdenum compound in the resin composition is preferably in the range of 0.05 to 5 parts by mass with respect to 100 parts by mass of the resin component. If the content of the molybdenum compound in the resin composition is within the above range, a sufficient effect of improving drillability can be obtained. Furthermore, the heat resistance of the metal-clad laminate can be maintained.

  The resin composition may further contain a curing accelerator. Thereby, hardening reaction (crosslinking reaction) with a reaction product (A) and cyanate resin (B) can be accelerated | stimulated. Therefore, the high glass transition temperature, heat resistance, and adhesion of the cured product can be ensured.

  The resin composition may contain other inorganic fillers different from the molybdenum compound particles. That is, by adding other inorganic fillers, in addition to the effect of reducing the thermal expansion coefficient by the crushed silica particles (D), it is possible to further reduce the thermal expansion coefficient. It is possible to impart characteristics such as flame retardancy and thermal conductivity that cannot be sufficiently obtained only by D). Other inorganic fillers can be appropriately selected from known fillers according to the purpose and are not limited, but those having relatively low hardness that are difficult to reduce drill workability are preferred, specifically Includes aluminum hydroxide, magnesium hydroxide, aluminum silicate, magnesium silicate, talc, clay, mica and the like.

  The resin composition may further contain, for example, additives such as a heat stabilizer, an antistatic agent, an ultraviolet absorber, a dye, a pigment, and a lubricant as long as the effects of the present invention are not impaired. .

[Resin varnish]
The resin varnish according to the present embodiment contains a resin composition and a solvent. This resin varnish is suitably used for the production of a prepreg described later.

  The solvent is not particularly limited as long as it can dissolve the resin component and does not inhibit the curing reaction, and examples thereof include organic solvents such as toluene, cyclohexanone, methyl ethyl ketone, and propylene glycol monomethyl ether acetate. Among these, the solvent is preferably at least one selected from the group consisting of toluene, cyclohexanone and propylene glycol monomethyl ether acetate.

  In preparing this resin varnish, for the purpose of promoting dissolution / dispersion of the solid component, the resin component may be heated in a temperature range where the resin component does not cause a curing reaction, if necessary. Furthermore, when an inorganic filler or a halogen-based flame retardant is added as necessary, the varnish may be agitated using a ball mill, a bead mill, a planetary mixer, a roll mill, or the like until a good dispersion state is obtained.

[Prepreg]
The prepreg according to the present embodiment has a fibrous base material and a semi-cured product of the resin composition that fills the fibrous base material and covers the surface of the fibrous base material.

  The fibrous base material is not particularly limited, and a base material woven so that warp and weft yarns are almost orthogonal, such as plain weave, can be used. For example, a fiber base made of organic fibers such as a woven fabric of inorganic fibers such as glass cloth, aramid cloth, polyester cloth, or the like can be used. The thickness of the fibrous base material is preferably 10 to 200 μm.

  Examples of the method for producing the prepreg include a method in which a fibrous base material is impregnated with a resin varnish, the solvent is dried, and the resin composition is heated and dried until the resin composition is in a semi-cured state (B stage state). The temperature conditions and time for making the semi-cured state be, for example, 120 to 190 ° C. and 3 to 15 minutes.

[Metal-clad laminate]
The metal-clad laminate according to the present embodiment includes a prepreg cured product and a metal foil on one or both sides of the cured product. That is, the configuration of the metal-clad laminate is a two-layer configuration consisting of a cured product of prepreg and a metal foil disposed on one side of the cured product, or a cured product of prepreg and disposed on both sides of the cured product. A three-layer structure consisting of a metal foil. A cured product of the prepreg is an insulating layer having insulating properties.

  Examples of the metal foil include copper foil, silver foil, aluminum foil, and stainless white peach. The thickness of metal foil is not specifically limited, Preferably it is 1.5-12 micrometers. The thickness of the metal-clad laminate is not particularly limited, and is preferably 20 to 400 μm. The metal-clad laminate is suitably used for manufacturing a printed wiring board using a subtractive method, a semi-additive method, a build-up method, or the like.

  Examples of the method for producing a metal-clad laminate include a method in which one or a plurality of prepregs are superposed, metal foils are superposed on both sides or one side, and the layers are integrated by heating and pressing. For heating and pressing, for example, a multistage vacuum press, a double belt, or the like can be used.

[Printed wiring board]
The printed wiring board according to the present embodiment includes a cured product of a prepreg and a conductor pattern on one side or both sides of the cured product. This printed wiring board has a prepreg cured product and a single-layer printed wiring board (hereinafter sometimes referred to as a core substrate) comprising a conductive pattern on one or both sides of the cured product, or the above-mentioned conductor pattern of the core substrate is formed. A multilayer printed wiring board in which a cured product of a prepreg that functions as an interlayer insulation layer and a conductor pattern that functions as a conductor pattern for an inner layer are alternately formed on the surface, and the conductor pattern is formed on the outermost layer. including.

  The shape, line width, line interval, thickness, etc. of the conductor pattern are not particularly limited, and may be appropriately adjusted according to the intended use.

  The method for producing a printed wiring board is not particularly limited, and examples thereof include known methods such as a subtractive method, a semi-additive method, a build-up method, a mass lamination method, and a pin lamination method.

  Hereinafter, the present invention will be specifically described by way of examples.

{Preparation of reaction product (A)}
The following materials were used as materials for preparing the reaction product (A).
(Polyphenylene ether)
PPE: “SA90” manufactured by SABIC Innovative Plastics (number average molecular weight: 1500, hydroxyl group: 1.9)
(Epoxy resin)
DCPD type epoxy resin: “HP7200” manufactured by DIC Corporation (dicyclopentadiene type epoxy resin, 2.3 average functional groups in one molecule)
(Curing accelerator during preliminary reaction)
Imidazole: “2E4MZ” (2-ethyl-4-imidazole) manufactured by Shikoku Kasei Kogyo Co., Ltd.

  After adding each component to toluene so that it may become the mixture ratio of Table 1, it was made to stir at 100 degreeC for 6 hours. That is, the reaction product (A) was prepared by reacting polyphenylene ether and epoxy resin in advance (preliminary reaction). The resulting reaction product (A) was prepared so that the solid content concentration was 60%.

<Examples 1-7, Comparative Examples 1, 3-7>
The following were used as each material for preparing the resin composition.

(Resin component)
Reaction product (A): Reaction product (A) prepared above
Cyanate resin (B): “BADCy” (2,2-bis (4-cyanatephenyl) propane, number average molecular weight: 280, average number of cyanate groups: 2) manufactured by Lonza Japan
(Curing accelerator)
Metal soap (C): zinc octoate (Zn-OCTOATE) manufactured by DIC Corporation
(Inorganic filler)
Spherical silica: “SC2500-SEJ” manufactured by Admatechs Co., Ltd. (spherical silica particles, average particle size: 0.8 μm, specific gravity: 2.2 g / cm ³ , with epoxy silane surface treatment)
・ Crushed silica 1 (D): “MC3000” manufactured by Admatechs Co., Ltd. (melted crushed silica particles, average particle size: 1 μm, no surface treatment)
-Crushed silica 2 (D): "Megasil 525" manufactured by Sibelco Japan Co., Ltd. (melt-crushed silica particles, average particle size: 1.6 μm, no surface treatment)
・ Fractured silica 3 (D): “Megasil 525RCS” manufactured by Sibelco Japan Co., Ltd. (fused silica particles, average particle size 1.6 μm, with epoxy silane surface treatment)
-Crushed silica 4 (D): "Megasil 535" manufactured by Sibelco Japan Co., Ltd. (melt-crushed silica particles, average particle size: 2.4 μm, no surface treatment)
-Crushed silica 5: "Megasil 503" manufactured by Sibelco Japan Co., Ltd. (melt-crushed silica particles, average particle size: 7 μm, no surface treatment).

  The reaction product (A) solution is heated to 30 to 35 ° C. so that the blending ratios described in Table 2 and Table 3 are obtained, and the cyanate resin (B) and metal soap (C) are added thereto. did. Then, it was completely dissolved by stirring for 30 minutes. Further, an inorganic filler was added and dispersed with a bead mill to obtain a varnish-like resin composition (resin varnish).

<Comparative example 2>
The following were used as each material for preparing the resin composition.

(Resin component)
PPE: “SA90” (number average molecular weight 1500, hydroxyl group: 1.9) manufactured by SABIC Innovative Plastics
Cyanate resin (B): “BADCy” (2,2-bis (4-cyanatephenyl) propane, number average molecular weight: 280, average number of cyanate groups: 2) manufactured by Lonza Japan
DCPD type epoxy resin: “EPICRON HP7200” manufactured by DIC Corporation (dicyclopentadiene type epoxy resin, 2.3 average functional groups in one molecule)
(Curing accelerator)
Metal soap: Zinc octoate (Zn-OCTOATE) manufactured by DIC Corporation
(Inorganic filler)
-Crushed silica 2 (D): "Megasil 525" (manufactured by Sibelco Japan Co., Ltd.) (melt-crushed silica particles, average particle size: 1.6 µm, no surface treatment).

  After adding each component to toluene so that it may become the mixture ratio of Table 3, it was made to stir at 30-35 degreeC for 60 minutes. Further, an inorganic filler was added and dispersed with a bead mill to obtain a varnish-like resin composition (resin varnish).

{Manufacture of prepreg}
Nittobo Co., Ltd. glass cloth (count: WEA116ES136, thickness: 100 μm) and Nittobo Co., Ltd. glass cloth (count: WEA1067S199, thickness: 50 μm) were used as the fibrous base material. The fibrous base material was impregnated with the resin varnishes of Examples 1 to 7 and Comparative Examples 1 to 6 at room temperature, and then dried by heating at 150 to 160 ° C. Thus, two kinds of prepregs were produced by removing the solvent in the resin varnish and semi-curing the resin composition. The resin content (resin amount) of the prepreg was 56% by mass.

  Further, a prepreg using a glass cloth (counter: WEA116ES136, thickness: 100 μm) manufactured by Nitto Boseki Co., Ltd. was used as a prepreg for evaluation of [resin fluidity (prepreg)] described later.

{Manufacture of metal-clad laminates}
The obtained prepreg (300 mm × 450 mm) is stacked one by one, and copper foil (made by Mitsui Metal Mining Co., Ltd., thickness: 35 μm) is stacked as a metal foil on both sides, and the conditions are 200 ° C. and 3 MPa for 90 minutes. A metal-clad laminate for evaluation (plate thickness: 0.12 mm) was produced by hot pressing.

  Moreover, 6 sheets of the obtained prepregs (300 mm × 450 mm) were stacked, and copper foil (made by Mitsui Metal Mining Co., Ltd., thickness: 35 μm) was stacked on both sides as a metal foil, and 90 ° C. under conditions of 200 ° C. and 3 MPa. A metal-clad laminate for evaluation (plate thickness: 0.8 mm) was produced by heating and pressing for minutes.

  As described above, two types of metal-clad laminates for evaluation having different thicknesses were obtained.

[Dielectric loss tangent (1 GHz)]
The dielectric tangent at 1 GHz of a metal-clad laminate for evaluation (plate thickness: 0.8 mm) was measured by a method based on IPC-TM-650-2.5.5.9. Specifically, the dielectric loss tangent at 1 GHz of the metal-clad laminate for evaluation was measured using an impedance analyzer (RF impedance analyzer “HP4291B” manufactured by Agilent Technologies).

[Interlayer adhesion strength (GC-Resin)]
The peel strength between the first and second glass cloths from a metal foil of a metal-clad laminate for evaluation (plate thickness: 0.8 mm) was measured in accordance with JIS C 6481. A pattern having a width of 10 mm and a length of 100 mm was formed, and peeled off at a speed of 50 mm / min with a tensile tester, and the peel strength at that time was measured.

[Heat resistance (T-288 (with 35 μm copper))]
According to IPC TM-650, a metal-clad laminate for evaluation (plate thickness: 0.8 mm) was used, and a TMA measuring device (“EXSTAR6000TMA” manufactured by Seiko Instruments Inc.) was used, and the temperature was increased to 288 at a heating rate of 10 ° C./min. After reaching 288 ° C., the temperature was kept constant, and the time from when it reached 288 ° C. until delamination occurred was measured.

[Coefficient of thermal expansion (thickness direction, less than Tg) (CTE (α1) Zaxis)]
A test piece (5 mm × 5 mm) obtained by etching away a copper foil of a metal-clad laminate for evaluation (plate thickness: 0.8 mm) was prepared, and a TMA measuring device (Seiko Instruments Inc.) was prepared using this test piece. ) “EXSTAR6000”) was used to measure the coefficient of thermal expansion α1 (ppm / ° C.) in the thickness direction (Z axis) of the test piece at a temperature rise of 75 to 120 ° C. (Tg or less).

[Resin fluidity (prepreg)]
(initial)
The initial resin fluidity was measured according to JIS C 6521. That is, an initial sample obtained by cutting a 100 mm square prepreg for evaluation that has not passed one day from the date of manufacture is sandwiched between stainless steel plates, heated and pressurized at a temperature of 175 ° C. and a pressure of 3 MPa for 40 minutes, and the center of the initial sample From the mass of the initial sample cut into a disk shape of 81.1 mm in diameter and cut into a 100 mm square (W ₀ ) and the mass of the disk-shaped initial sample cut after heating and pressing (W ₁ ), Calculated.
Resin fluidity (%) = 100 × (W ₀ -2W ₁ ) / W ₀

(90 days later)
From the date of manufacture to room temperature (about 20 to 25 ° C.), except that an elapsed sample obtained by cutting a prepreg for evaluation left in the atmosphere for 90 days into a 100 mm square was used instead of the initial sample, the same as (initial), Resin fluidity (%) was calculated.

(Decrease rate from the beginning)
The decrease rate from the initial stage was calculated from the following formula. In the following formula, “initial” means the initial resin fluidity (%), and “after 90 days” means the resin fluidity (%) after 90 days.
Decreasing rate from the beginning (%) = [{(initial) − (after 90 days)} / (initial)] × 100

[Boiled solder heat resistance]
(initial)
An evaluation-use metal-clad laminate (plate thickness: 0.8 mm) that has not passed since the date of manufacture was used as an initial sample. The initial sample was boiled for 2 hours, cooled with running water for 30 minutes, sufficiently wiped off the surface moisture, immersed in a solder bath at 260 ° C. for 30 seconds, cooled to room temperature, and visually evaluated for appearance. . Those with no abnormalities such as blistering and peeling are indicated by “◯”, and those having abnormality are indicated by “X”.

(90 days later)
Other than using a metal-clad laminate for evaluation (plate thickness: 0.8 mm) left at room temperature (about 20-25 ° C.) in the atmosphere for 90 days from the date of manufacture, In the same manner, boiling was performed, immersion in a solder bath, cooling to room temperature, and the appearance was evaluated visually.

[Withstand voltage (plate thickness: 0.12 mm)]
A flat electrode having a diameter of 100 mm was placed on the front and back of a metal-clad laminate for evaluation (plate thickness: 0.12 mm), and the test voltage shown in Table 1 or 2 was applied for 60 seconds. The case where no destructive discharge occurred during application of the test voltage was indicated by “◯”, and the case where destructive discharge occurred was indicated by “x”.

  The results of the above physical property evaluation are shown in Table 2 and Table 3.

  In Examples 1 to 7, the reaction product (A) and the crushed silica (D) are contained, and the content of the crushed silica (D) is 100 parts by mass of the reaction product (A) and the cyanate resin (B). On the other hand, the average particle diameter of the crushed silica (D) was 1 μm to 5 μm because of 20 to 70 parts by mass, so that the dielectric loss tangent (1 GHz), interlayer adhesion strength (GC-Resin), and heat resistance (T-288) ), Thermal expansion coefficient (thickness direction, less than Tg), resin fluidity (prepreg), boiling solder heat resistance and withstand voltage (plate thickness 0.12 mm). In other words, the thermal expansion coefficient is low, and even if left at room temperature, the resin fluidity does not easily deteriorate over time, and it has excellent storage properties, and also has excellent dielectric loss tangent, interlayer adhesion strength, heat resistance, boiling solder heat resistance, and voltage resistance. It was confirmed that the resin composition can be used as a wiring board.

  On the other hand, in Comparative Example 1, since spherical silica (with surface treatment, average particle size 0.6 μm) is contained, the rate of decrease in resin fluidity (prepreg) from the beginning is high, and boiling solder heat resistance (after 90 days) ) Was not good.

  In Comparative Example 2, since the reaction product (A) which is a pre-reacted product was not used, the polyphenylene ether and the epoxy resin which are raw materials of the reaction product (A) were reacted with the cyanate resin (B) as they were. The strength (GC-Resin) and heat resistance (T-288) were not good.

  In Comparative Example 3, since the content of crushed silica (D) is less than 20 parts by mass with respect to 100 parts by mass of the reaction product (A) and cyanate resin (B), the dielectric loss tangent and the coefficient of thermal expansion (thickness direction) , Less than Tg) was not good.

  In Comparative Example 4, crushed silica was contained, but since the average particle size of the crushed silica was more than 5 μm, the withstand voltage was not good.

  In Comparative Examples 5 to 7, since the content of crushed silica (D) is more than 70 parts by mass with respect to 100 parts by mass of the reaction product (A) and the cyanate resin (B), the interlayer adhesion strength (GC-Resin ), Boiling solder heat resistance and withstand voltage were not good. Further, in Comparative Examples 5 and 7, the heat resistance (T-288) was not good.

  Comparing Comparative Example 3, Example 3, Example 7 and Comparative Example 5 with respect to resin fluidity (prepreg), the greater the content of crushed silica (D), the greater the resin fluidity (initial and 90 days later). It has been found that the prepreg tends to decrease more. In the comparison of Example 6, Example 2, Example 5, and Comparative Example 6 using the surface-treated crushed silica (D), and the comparison of Example 1 and Comparative Example 7, the same tendency is observed. I understood. That is, it was found that the content of crushed silica greatly affects the resin fluidity (prepreg).

Claims (7)

A reaction product (A) of a polyphenylene ether having a hydroxyl group and an epoxy resin;
A cyanate resin (B) having an average of two or more cyanate groups in one molecule;
Metal soap (C),
Containing crushed silica (D),
Content of the said crushed silica (D) is 20-70 mass parts with respect to 100 mass parts of reaction products (A) and cyanate resin (B),
An average particle size of the crushed silica (D) is 1 μm to 5 μm.   The resin composition according to claim 1, wherein the crushed silica (D) has a surface modified with a coupling agent.   A resin varnish containing the resin composition according to claim 1 or 2 and a solvent.   The resin varnish according to claim 3, wherein the solvent is at least one selected from the group consisting of toluene, cyclohexanone, and propylene glycol monomethyl ether acetate.   It has a fibrous base material and the semi-cured product of the resin composition according to claim 1 or 2, which is filled in the fibrous base material and covers the surface of the fibrous base material. Prepreg.   A metal-clad laminate having the cured product of the prepreg according to claim 5 and a metal foil on one or both sides of the cured product.   The printed wiring board which has the hardened | cured material of the prepreg of Claim 5, and a conductor pattern on the single side | surface or both surfaces of the said hardened | cured material.